1. |
- Abbas, Abdul-Karim, 1959, et al.
(författare)
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Long-term potentiation and insult conditioning in hippocampal slices from young rats: a role for protein synthesis under chemical stress?
- 2010
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Ingår i: The 10th Biennial Meeting of the Asia-Pacific Society for Neurochemistry (APSN), October 17-20, 2010, Phuket, Thailand.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- We have previously demonstrated that in young rats (12-20-day-old) a sustained long-term potentiation (LTP) can still be induced under conditions of protein synthesis inhibition. It was therefore suggested that sufficient and necessary proteins were already available at the induction time to accomplish LTP maintenance for several hours. Against this background, we have questioned whether hippocampal slices subjected to certain insult conditions might be more sensitive to protein synthesis inhibitors. High K+ concentration has previously been reported to cause an amnesic effect in vivo as well as increasing protein turnover in vitro. We have here employed a K+ insult model under conditions when protein synthesis was inhibited. Recordings were obtained from hippocampal slices for up to 9 h, with or without a cocktail of protein synthesis inhibitors, containing cycloheximide (60 µM) and anisomycin (25 µM). High potassium (50 mM) was transiently applied (5-15 min) shortly after inducing LTP in one of two separate pathways stimulated alternatively. Additionally, an NMDA-receptor antagonist AP5 was supplied after LTP induction to minimize effects related to depolarization-induced glutamate release. Following elimination of all responses for about 30 min, both test and control responses partly recovered. The degree of remaining LTP, defined as test/control ratio, was reduced in both groups of slices (NMDA-independent depotentiation) but was significantly smaller in the drug-treated ones. We are also running an insult model based on oxidative stress, applying hydrogen peroxide (4-5 mM) before or after LTP induction; however, the results are still insufficient for a final conclusion. The potency of cycloheximide, anisomycin or cocktail of the drugs was verified by measurement of incorporation of [3H]-leucine into trichloracetic acid (TCA) precipitable macromolecules. Cycloheximide, anisomycin or cocktail, at concentrations used here caused 95%, 97% and 95% blocking effect, respectively. Our data confirm the idea that sufficient and necessary constitutive proteins are available in the young hippocampus to maintain LTP under conditions of protein synthesis inhibition. They also reveal that LTP in slices subjected to certain insult conditions early after the induction is sensitive to protein synthesis inhibition, probably due to increase in constitutive proteins turnover.
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2. |
- Bauzá-Thorbrügge, Marco, et al.
(författare)
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NRF2 is essential for adaptative browning of white adipocytes.
- 2023
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Ingår i: Redox biology. - : Elsevier. - 2213-2317. ; 68
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Tidskriftsartikel (refereegranskat)abstract
- White adipose tissue browning, defined by accelerated mitochondrial metabolism and biogenesis, is considered a promising mean to treat or prevent obesity-associated metabolic disturbances. We hypothesize that redox stress acutely leads to increased production of reactive oxygen species (ROS), which activate electrophile sensor nuclear factor erythroid 2-Related Factor 2 (NRF2) that over time results in an adaptive adipose tissue browning process. To test this, we have exploited adipocyte-specific NRF2 knockout mice and cultured adipocytes and analyzed time- and dose-dependent effect of NAC and lactate treatment on antioxidant expression and browning-like processes. We found that short-term antioxidant treatment with N-acetylcysteine (NAC) induced reductive stress as evident from increased intracellular NADH levels, increased ROS-production, reduced oxygen consumption rate (OCR), and increased NRF2 levels in white adipocytes. In contrast, and in line with our hypothesis, longer-term NAC treatment led to a NRF2-dependent browning response. Lactate treatment elicited similar effects as NAC, and mechanistically, these NRF2-dependent adipocyte browning responses in vitro were mediated by increased heme oxygenase-1 (HMOX1) activity. Moreover, this NRF2-HMOX1 axis was also important for β3-adrenergic receptor activation-induced adipose tissue browning in vivo. In conclusion, our findings show that administration of exogenous antioxidants can affect biological function not solely through ROS neutralization, but also through reductive stress. We also demonstrate that NRF2 is essential for white adipose tissue browning processes.
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3. |
- Solinas, Giovanni, et al.
(författare)
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An adipoincretin effect links adipostasis with insulin secretion.
- 2024
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Ingår i: Trends in endocrinology and metabolism: TEM. - 1879-3061. ; 35:6, s. 466-477
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Forskningsöversikt (refereegranskat)abstract
- The current paradigm for the insulin system focuses on the phenomenon of glucose-stimulated insulin secretion and insulin action on blood glucose control. This historical glucose-centric perspective may have introduced a conceptual bias in our understanding of insulin regulation. A body of evidence demonstrating that in vivo variations in blood glucose and insulin secretion can be largely dissociated motivated us to reconsider the fundamental design of the insulin system as a control system for metabolic homeostasis. Here, we propose that a minimal glucose-centric model does not accurately describe the physiological behavior of the insulin system and propose a new paradigm focusing on the effects of incretins, arguing that under fasting conditions, insulin is regulated by an adipoincretin effect.
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4. |
- Lindberg, Frida A., et al.
(författare)
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SLC38A10 Deficiency in Mice Affects Plasma Levels of Threonine and Histidine in Males but Not in Females : A Preliminary Characterization Study of SLC38A10(-/-) Mice
- 2023
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Ingår i: Genes. - : MDPI. - 2073-4425. ; 14:4
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Tidskriftsartikel (refereegranskat)abstract
- Solute carriers belong to the biggest group of transporters in the human genome, but more knowledge is needed to fully understand their function and possible role as therapeutic targets. SLC38A10, a poorly characterized solute carrier, is preliminary characterized here. By using a knockout mouse model, we studied the biological effects of SLC38A10 deficiency in vivo. We performed a transcriptomic analysis of the whole brain and found seven differentially expressed genes in SLC38A10-deficient mice (Gm48159, Nr4a1, Tuba1c, Lrrc56, mt-Tp, Hbb-bt and Snord116/9). By measuring amino acids in plasma, we found lower levels of threonine and histidine in knockout males, whereas no amino acid levels were affected in females, suggesting that SLC38A10(-/-) might affect sexes differently. Using RT-qPCR, we investigated the effect of SLC38A10 deficiency on mRNA expression of other SLC38 members, Mtor and Rps6kb1 in the brain, liver, lung, muscle, and kidney, but no differences were found. Relative telomere length measurement was also taken, as a marker for cellular age, but no differences were found between the genotypes. We conclude that SLC38A10 might be important for keeping amino acid homeostasis in plasma, at least in males, but no major effects were seen on transcriptomic expression or telomere length in the whole brain.
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5. |
- Eriksson, Leif A., 1964-, et al.
(författare)
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Tetrazole derivatives as cytochrome p450 inhibitors
- 2019
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Patent (populärvet., debatt m.m.)abstract
- According to the invention there is provided a compound of formula I, wherein R1 and R2 have meanings given in the description, which compounds are useful in the treatment of skin disorders and other diseases.
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6. |
- Izsak, Julia, et al.
(författare)
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Differential acute impact of therapeutically effective and overdose concentrations of lithium on human neuronal single cell and network function
- 2021
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Ingår i: Translational Psychiatry. - : Springer Science and Business Media LLC. - 2158-3188. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Lithium salts are used as mood-balancing medication prescribed to patients suffering from neuropsychiatric disorders, such as bipolar disorder and major depressive disorder. Lithium salts cross the blood-brain barrier and reach the brain parenchyma within few hours after oral application, however, how lithium influences directly human neuronal function is unknown. We applied patch–clamp and microelectrode array technology on human induced pluripotent stem cell (iPSC)-derived cortical neurons acutely exposed to therapeutic (<1 mM) and overdose concentrations (>1 mM) of lithium chloride (LiCl) to assess how therapeutically effective and overdose concentrations of LiCl directly influence human neuronal electrophysiological function at the synapse, single-cell, and neuronal network level. We describe that human iPSC-cortical neurons exposed to lithium showed an increased neuronal activity under all tested concentrations. Furthermore, we reveal a lithium-induced, concentration-dependent, transition of regular synchronous neuronal network activity using therapeutically effective concentration (<1 mM LiCl) to epileptiform-like neuronal discharges using overdose concentration (>1 mM LiCl). The overdose concentration lithium-induced epileptiform-like activity was similar to the epileptiform-like activity caused by the GABAA-receptor antagonist. Patch–clamp recordings reveal that lithium reduces action potential threshold at all concentrations, however, only overdose concentration causes increased frequency of spontaneous AMPA-receptor mediated transmission. By applying the AMPA-receptor antagonist and anti-epileptic drug Perampanel, we demonstrate that Perampanel suppresses lithium-induced epileptiform-like activity in human cortical neurons. We provide insights in how therapeutically effective and overdose concentration of lithium directly influences human neuronal function at synapse, a single neuron, and neuronal network levels. Furthermore, we provide evidence that Perampanel suppresses pathological neuronal discharges caused by overdose concentrations of lithium in human neurons.
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8. |
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9. |
- Järemo, Petter, et al.
(författare)
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Alzheimer's disease and granulocyte density diversity
- 2013
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Ingår i: European Journal of Clinical Investigation. - : John Wiley & Sons. - 0014-2972 .- 1365-2362. ; 43:6, s. 545-548
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND:The current study investigates circulating eosinophils and neutrophils in Alzheimer's (AD) type dementia with respect to density (kg/L). The existence of β-amyloid plaques in the brain is a feature of AD. Sporadic scientific reports indicate that the disease affects circulating neutrophils. In contrast, numerous publications investigate inflammatory reactions in AD brains. Locally, the plaques evoke a substantial inflammatory response involving activated microglia and astrocytes.METHODS:Subjects with probable AD (n = 39) were included and compared with elderly individuals (n = 22) lacking apparent memory problems. We sampled 10 mL venous blood in citrate. Granulocytes were separated according to density in linear Percoll™ gradients. Subsequently, the gradients were divided into density subfractions (n = 16). In every fraction, determination of eosinophil and neutrophil counts was carried out.RESULTS:AD sufferers displayed less granulocytes in fractions nos. 13-15 containing light cells. For these fractions, the P-values proved to be (P < 0·001; not significant; P = 0·03) and (P = 0·01; P = 0·01; not significant), for eosinophils and neutrophils, respectively.CONCLUSIONS:The present work describes that less circulating light granulocytes are a feature of AD demented individuals. It is to hypothesize that it is a sign of impaired granulocyte turnover and cell damage. It is concluded that AD affects inflammatory cells in the periphery and that the behaviour of granulocytes in dementia is worthwhile further studies.
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10. |
- Molinaro, Angela, et al.
(författare)
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Insulin-Driven PI3K-AKT Signaling in the Hepatocyte Is Mediated by Redundant PI3Kα and PI3Kβ Activities and Is Promoted by RAS.
- 2019
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Ingår i: Cell Metabolism. - : Elsevier BV. - 1550-4131 .- 1932-7420. ; 29:6
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Tidskriftsartikel (refereegranskat)abstract
- Phosphatidylinositol-3-kinase (PI3K) activity is aberrant in tumors, and PI3K inhibitors are investigated as cancer therapeutics. PI3K signaling mediates insulin action in metabolism, but the role of PI3K isoforms in insulin signaling remains unresolved. Defining the role of PI3K isoforms in insulin signaling is necessary for a mechanistic understanding of insulin action and to develop PI3K inhibitors with optimal therapeutic index. We show that insulin-driven PI3K-AKT signaling depends on redundant PI3Kα and PI3Kβ activities, whereas PI3Kδ and PI3Kγ are largely dispensable. We have also found that RAS activity promotes AKT phosphorylation in insulin-stimulated hepatocytes and that promotion of insulin-driven AKT phosphorylation by RAS depends on PI3Kα. These findings reveal the detailed mechanism by which insulin activates AKT, providing an improved mechanistic understanding of insulin signaling. This improved model for insulin signaling predicts that isoform-selective PI3K inhibitors discriminating between PI3Kα and PI3Kβ should bedosed below their hyperglycemic threshold to achieve isoform selectivity.
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11. |
- Mondal, Tanmoy, 1981, et al.
(författare)
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Sense-antisense lncRNA pair encoded by locus 6p22.3 determines neuroblastoma susceptibility via the USP36-CHD7-SOX9 regulatory axis
- 2018
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Ingår i: Cancer Cell. - : Elsevier BV. - 1535-6108 .- 1878-3686. ; 33:3
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Tidskriftsartikel (refereegranskat)abstract
- Trait-associated loci often map to genomic regions encoding long noncoding RNAs (lncRNAs), but the role of these lncRNAs in disease etiology is largely unexplored. We show that a pair of sense/antisense lncRNA (6p22lncRNAs) encoded by CASC15 and NBAT1 located at the neuroblastoma (NB) risk-associated 6p22.3 locus are tumor suppressors and show reduced expression in high-risk NBs. Loss of functional synergy between 6p22lncRNAs results in an undifferentiated state that is maintained by a gene-regulatory network, including SOX9 located on 17q, a region frequently gained in NB. 6p22lncRNAs regulate SOX9 expression by controlling CHD7 stability via modulating the cellular localization of USP36, encoded by another 17q gene. This regulatory nexus between 6p22.3 and 17q regions may lead to potential NB treatment strategies.
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12. |
- Di Gennaro, A., et al.
(författare)
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Cysteinyl leukotriene receptor 1 antagonism prevents experimental abdominal aortic aneurysm
- 2018
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 115:8, s. 1907-1912
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Tidskriftsartikel (refereegranskat)abstract
- Cysteinyl-leukotrienes (cys-LTs) are 5-lipoxygenase-derived lipid mediators involved in the pathogenesis and progression of inflammatory disorders, in particular asthma. We have previously found evidence linking these mediators to increased levels of proteolytic enzymes in tissue specimens of human abdominal aortic aneurysm (AAA). Here we show that antagonism of the CysLT1 receptor by montelukast, an established antiasthma drug, protects against a strong aorta dilatation (>50% increase = aneurysm) in a mouse model of CaCl2-induced AAA at a dose comparable to human medical practice. Analysis of tissue extracts revealed that montelukast reduces the levels of matrix metalloproteinase-9 (MMP-9) and macrophage inflammatory protein-1 alpha (MIP-1 alpha) in the aortic wall. Furthermore, aneurysm progression was specifically mediated through CysLT1 signaling since a selective CysLT2 antagonist was without effect. A significantly reduced vessel dilatation is also observed when treatment with montelukast is started days after aneurysm induction, suggesting that the drug not only prevents but also stops and possibly reverts an already ongoing degenerative process. Moreover, montelukast reduced the incidence of aortic rupture and attenuated the AAA development in two additional independent models, i.e., angiotensin II- and porcine pancreatic elastase-induced AAA, respectively. Our results indicate that cys-LTs are involved in the pathogenesis of AAA and that antagonism of the CysLT1 receptor is a promising strategy for preventive and therapeutic treatment of this clinically silent and highly lethal disease.
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13. |
- Bhandage, Amol K., 1988-
(författare)
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Glutamate and GABA signalling components in the human brain and in immune cells
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Glutamate and γ-aminobutyric acid (GABA) are the principal excitatory and inhibitory neurotransmitters in the central nervous system (CNS). They both can activate their ionotropic and metabotropic receptors. Glutamate activates ionotropic glutamate receptors (iGlu - AMPA, kainate and NMDA receptors) and GABA activates GABA-A receptors which are modulated by many types of drugs and substances including alcohol. Using real time quantitative polymerase chain reaction, I have shown that iGlu and/or GABA-A receptor subunits were expressed in the hippocampus dentate gyrus (HDG), orbitofrontal cortex (OFC), dorsolateral prefrontal cortex (DL-PFC), central amygdala (CeA), caudate and putamen of the human brain and their expression was altered by chronic excessive alcohol consumption. It indicates that excitatory and inhibitory neurotransmission may have been altered in the brain of human alcoholics. It is possible that changes in one type of neurotransmitter system may drive changes in another. These brain regions also play a role in brain reward system. Any changes in them may lead to changes in the normal brain functions.Apart from the CNS, glutamate and GABA are also present in the blood and can be synthesised by pancreatic islet cells and immune cells. They may act as immunomodulators of circulating immune cells and can affect immune function through glutamate and GABA receptors. I found that T cells from human, rat and mouse lymph nodes expressed the mRNAs and proteins for specific GABA-A receptor subunits. GABA-evoked transient and tonic currents recorded using the patch clamp technique demonstrate the functional GABA-A channel in T cells. Furthermore, the mRNAs for specific iGlu, GABA-A and GABA-B receptor subunits and chloride cotransporters were detected in peripheral blood mononuclear cells (PBMCs) from men, non-pregnant women, healthy and depressed pregnant women. The results indicate that the expression of iGlu, GABA-A and GABA-B receptors is related to gender, pregnancy and mental health and support the notion that glutamate and GABA receptors may modulate immune function. Intra- and interspecies variability exists in the expression and it is further influenced by physiological conditions.
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14. |
- Gustafsson, Gabriel, et al.
(författare)
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Secretion and uptake of α-synuclein via extracellular vesicles in cultured cells
- 2018
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Ingår i: Cellular and molecular neurobiology. - : Springer Science and Business Media LLC. - 0272-4340 .- 1573-6830. ; 38:8, s. 1539-1550
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Tidskriftsartikel (refereegranskat)abstract
- In Parkinson’s disease and other Lewy body disorders, the propagation of pathology has been accredited to the spreading of extracellular α-synuclein (α-syn). Although the pathogenic mechanisms are not fully understood, cell-to-cell transfer of α-syn via exosomes and other extracellular vesicles (EVs) has been reported. Here, we investigated whether altered molecular properties of α-syn can influence the distribution and secretion of α-syn in human neuroblastoma cells. Different α-syn variants, including α-syn:hemi-Venus and disease-causing mutants, were overexpressed and EVs were isolated from the conditioned medium. Of the secreted α-syn, 0.1–2% was associated with vesicles. The major part of EV α-syn was attached to the outer membrane of vesicles, whereas a smaller fraction was found in their lumen. For α-syn expressed with N-terminal hemi-Venus, the relative levels associated with EVs were higher than for WT α-syn. Moreover, such EV-associated α-syn:hemi-Venus species were internalized in recipient cells to a higher degree than the corresponding free-floating forms. Among the disease-causing mutants, A53T α-syn displayed an increased association with EVs. Taken together, our data suggest that α-syn species with presumably lost physiological functions or altered aggregation properties may shift the cellular processing towards vesicular secretion. Our findings thus lend further support to the tenet that EVs can mediate spreading of harmful α-syn species and thereby contribute to the pathology in α-synucleinopathies.
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15. |
- Lindberg, Frida A, et al.
(författare)
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SLC38A10 deficiency in male mice affect plasma levels of threonine and histidine
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Solute carriers belong to the biggest group of transporters in the human genome, but more knowledge is needed in order to fully understand their function and possible role as therapeutic targets. SLC38 is a family of amino acid transporters, commonly referred to as SNATs, consisting of 11 members. The tenth member, SLC38A10, is one of the least characterized members and is the focus of this study. By using a knockout mouse model, we studied the biological effects of SLC38A10 deficiency in vivo. We performed a transcriptomic analysis of whole brain and found seven differentially expressed genes in SLC38A10 deficient mice (Gm48159, Nr4a1, Tuba1c, Lrrc56, mt-Tp, Hbb-bt and Snord116/9). By measuring amino acids in plasma, we found lower levels of threonine and histidine in males, while no amino acids were altered in females, suggesting that SLC38A10-/- might affect sexes differently. Using RT-qPCR, we investigated the effect of SLC38A10 deficiency on mRNA expression of other SLC38 members, Mtor and Rps6kb1 in brain, liver, lung, muscle and kidney, but no differences were found. A relative telomere length measurement was also made, as a marker for cellular age, but no differences were found between the genotypes. We conclude that SLC38A10 might be important for keeping amino acid homeostasis in plasma, at least in males, but no major effects were seen on transcriptomic expression or telomere length in whole brain.
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16. |
- Osborn, K. E., et al.
(författare)
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Cerebrospinal fluid beta-amyloid(42) and neurofilament light relate to white matter hyperintensities
- 2018
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Ingår i: Neurobiology of Aging. - : Elsevier BV. - 0197-4580. ; 68, s. 18-25
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Tidskriftsartikel (refereegranskat)abstract
- White matter hyperintensities (WMHs) are associated with poorer brain health, but their pathophysiological substrates remain elusive. To better understand the mechanistic underpinnings of WMHs among older adults, this study examined in vivo cerebrospinal fluid biomarkers of beta-amyloid(42) deposition (A beta(42)), hyperphosphorylated tau pathology, neurodegeneration (total tau), and axonal injury (neurofilament light [NFL]) in relation to log-transformed WMHs volume. Participants free of clinical stroke and dementia were drawn from the Vanderbilt Memory & Aging Project (n = 148, 72 +/- 6 years). Linear regression models adjusted for age, sex, race/ethnicity, education, intracranial volume, modified Framingham Stroke Risk Profile (excluding points assigned for age), cognitive diagnosis, and APOE-epsilon 4 carrier status. A beta(42) (beta = -0.001, p = 0.007) and NFL (beta = 0.0003, p = 0.01) concentrations related to WMHs but neither hyperphosphorylated tau nor total tau associations with WMHs reached statistical significance (p-values > 0.21). In a combined model, NFL accounted for 3.2% of unique variance in WMHs and A beta(42) accounted for an additional 4.3% beyond NFL, providing novel evidence of the co-occurrence of at least 2 distinct pathways for WMHs among older adults, including amyloid deposition and axonal injury. (C) 2018 Elsevier Inc. All rights reserved.
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20. |
- Lai, Kuei-Hung
(författare)
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Studies on anti-leukemic terpenoids from medicinal mushrooms and marine sponges with ChemGPS-NP-based targets investigation of lead compounds
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis investigates the anti-leukemic activity of terpenoids isolated from medicinal mushrooms and marine sponges, as well as their possible targets and mechanisms of action.In the first section, we focused on studying the triterpenoidal components of three triterpenoid-enriched medicinal mushrooms Antrodia cinnamomea, Ganoderma lucidum, and Poria cocos, which have been used in folk medicine for centuries and also developed into several contemporary marketed products. We isolated the major and characteristic triterpenoids from these mushrooms, together with six new lanostanoids (II-1–II-6). The anti-leukemic activity of the isolates was evaluated in vitro using MTT proliferative assay and seven of them exhibited potential anti-leukemic effect. The active lead compounds were further subjected to computational analyses utilizing the ChemGPS-NP tool. We established a database for the anti-leukemic relevant chemical space of triterpenoids isolated from these three medicinal mushrooms, which could be used as a reference database for further research on anti-leukemic triterpenoids. Our results indicated that the anti-leukemic effect of the active lead compounds was mediated not only through topoisomerases inhibition but also through inhibiting DNA polymerases.The second and third sections focused on isolation of anti-leukemic sesterterpenoids from sponges. The investigation of Carteriospongia sp. led to the isolation of two new scalarane-type sesterterpenoids (III-1 and III-2) and one known tetraprenyltoluquinol-related metabolite (III-3). All isolates exhibit an apoptotic mechanism of action against Molt 4 cells, found to be mediated through the disruption of the mitochondrial membrane potential (MMP) and inhibition of topoisomerase IIα expression. Detailed investigation of the apoptotic mechanism of action using molecular docking analysis revealed that compound III-1 might target Hsp90 protein. The apoptotic-inducing effect of III-3 was supported by in vivo experiment by suppressing the volume of xenograft tumor growth (47.58%) compared with the control.In the final section of this thesis we studied manoalide and its derivatives, sesterterpenoids isolated from the sponge Luffariella sp.. Manoalide has been studied as a potential anti-inflammatory agent for the last thirty years with more than 200 publications and 40 patents. However, the configurations at positions 24 and 25 were never revealed. In the current study, ten manoalide-type sesterterpenoids (IV-1–IV-10) were isolated from Luffariella sp. and their stereoisomers at positions 24 and 25 were identified and separated for the first time. The configuration at positions 24 and 25 showed to have a significant effect on the anti-leukemic activity of manoalide derivatives, with the 24R,25S-isomer exhibiting the most potent anti-leukemic activity. The apoptotic mechanism of action of compound IV-7 against Molt 4 cells was investigated, and the compound was found to trigger MMP disruption and intracellular reactive oxygen species (ROS) generation. Compound IV-7 also inhibited activity against both human topoisomerases, I and II. The in vivo experiment further supported the anti-leukemic effect of IV-7 with a 66.11% tumor volume suppression compared to the control.
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21. |
- Rodríguez-Piñeiro, Ana María, et al.
(författare)
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The colonic mucus protection depends on the microbiota
- 2015
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Ingår i: Gut microbes. - : Informa UK Limited. - 1949-0976 .- 1949-0984. ; 6:5, s. 326-30
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The intestinal mucus is a pivotal part of our intestinal protection. It provides slow diffusion of protective molecules, trapping of luminal material as bacteria and smooth transport in the small intestine. In colon it restricts bacterial access to the epithelium limiting the responses to the enormous bacterial load present at this location. The development of these systems depends on the microbiota composition as seen in our recent study comparing the mucus phenotype in 2 colonies kept in different husbandries within the same SPF animal facility. One colony had impenetrable colonic mucus while the other colony had more penetrable mucus. The mucus phenotypes were transmitted via the microbiota and clear differences in its composition could be detected. Candidates associated with the different colonies were identified but the observed mucus difference could not be assigned to a specific bacterium.
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23. |
- Fritz, Michael, 1981-, et al.
(författare)
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Interferon-ɣ mediated signaling in the brain endothelium is critical for inflammation-induced aversion
- 2018
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Ingår i: Brain, behavior, and immunity. - Maryland Heights : Academic Press. - 0889-1591 .- 1090-2139. ; 67, s. 54-58
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Tidskriftsartikel (refereegranskat)abstract
- Systemic inflammation elicits malaise and a negative affective state. The mechanism underpinning the aversive component of inflammation include cerebral prostaglandin synthesis and modulation of dopaminergic reward circuits, but the messengers that mediate the signaling between the peripheral inflammation and the brain have not been sufficiently characterized. Here we investigated the role of interferon-ɣ (IFN-ɣ) in the aversive response to systemic inflammation induced by a low dose (10μg/kg) of lipopolysaccharide (LPS) in mice. LPS induced IFN-ɣ expression in the blood and deletion of IFN-ɣ or its receptor prevented the development of conditioned place aversion to LPS. LPS induced expression of the chemokine Cxcl10 in the striatum of normal mice, but this induction was absent in mice lacking IFN-ɣ receptors or Myd88 in blood brain barrier endothelial cells. Furthermore, inflammation-induced aversion was blocked in mice lacking Cxcl10 or its receptor Cxcr3. Finally, mice with a selective deletion of the IFN-ɣ receptor in brain endothelial cells did not develop inflammation-induced aversion, demonstrating that the brain endothelium is the critical site of IFN-ɣ action. Collectively, these findings show that circulating IFN-ɣ that binds to receptors on brain endothelial cells and induces Cxcl10, is a central link in the signaling chain eliciting inflammation-induced aversion.
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24. |
- Klawonn, Anna, 1985-
(författare)
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Molecular Mechanisms of Reward and Aversion
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Various molecular pathways in the brain shape our understanding of good and bad, as well as our motivation to seek and avoid such stimuli. This work evolves around how systemic inflammation causes aversion; and why general unpleasant states such as sickness, stress, pain and nausea are encoded by our brain as undesirable; and contrary to these questions, how drugs of abuse can subjugate the motivational neurocircuitry of the brain. A common feature of these various disease states is involvement of the motivational neurocircuitry - from mesolimbic to striatonigral pathways. Having an intact motivational system is what helps us evade negative outcomes and approach natural positive reinforcers, which is essential for our survival. During disease-states the motivational neurocircuitry may be overthrown by the molecular mechanisms that originally were meant to aid us.In study I, to investigate how inflammation is perceived as aversive, we used a behavioral test based on Pavlovian place conditioning with the aversive inflammatory stimulus E. coli lipopolysaccharide (LPS). Using a combination of cell-type specific gene deletions, pharmacology, and chemogenetics, we uncovered that systemic inflammation triggered aversion by MyD88-dependent activation of the brain endothelium followed by COX1-mediated cerebral prostaglandin E2 (PGE2) synthesis. Moreover, we showed that inflammation-induced PGE2 targeted EP1 receptors on striatal dopamine D1 receptor–expressing neurons and that this signaling sequence induced aversion through GABA-mediated inhibition of dopaminergic cells. Finally, inflammation-induced aversion was not an indirect consequence of fever or anorexia but constituted an independent inflammatory symptom triggered by a unique molecular mechanism. Collectively, these findings demonstrate that PGE2-mediated modulation of the dopaminergic circuitry is a key mechanism underlying inflammation-induced aversion.In study II, we investigate the role of peripheral IFN-γ in LPS induced conditioned place aversion by employing a strategy based on global and cell-type specific gene deletions, combined with measures of gene-expression. LPS induced IFN-ɣ expression in the blood, and deletion of IFN-ɣ or its receptor prevented conditioned place aversion (CPA) to LPS. LPS increased the expression of chemokine Cxcl10 in the striatum of normal mice. This induction was absent in mice lacking IFN-ɣ receptors or Myd88 in blood brain barrier endothelial cells. Furthermore, inflammation-induced aversion was blocked in mice lacking Cxcl10 or its receptor Cxcr3. Finally, mice with a selective deletion of the IFN-ɣ receptor in brain endothelial cells did not develop inflammation-induced aversion. Collectively, these findings demonstrate that circulating IFN-ɣ binding to receptors on brain endothelial cells which induces Cxcl10, is a central link in the signaling chain eliciting inflammation-induced aversion.In study III, we explored the role of melanocortin 4 receptors (MC4Rs) in aversive processing using genetically modified mice in CPA to various stimuli. In normal mice, robust aversions were induced by systemic inflammation, nausea, pain and kappa opioid receptor-induced dysphoria. In sharp contrast, mice lacking MC4Rs displayed preference towards most of the aversive stimuli, but were indifferent to pain. The unusual flip from aversion to reward in mice lacking MC4Rs was dopamine-dependent and associated with a change from decreased to increased activity of the dopamine system. The responses to aversive stimuli were normalized when MC4Rs were re-expressed on dopamine D1 receptor-expressing cells or in the striatum of mice otherwise lacking MC4Rs. Furthermore, activation of arcuate nucleus proopiomelanocortin neurons projecting to the ventral striatum increased the activity of striatal neurons in a MC4R-dependent manner and elicited aversion. Our findings demonstrate that melanocortin signaling through striatal MC4Rs is critical for assigning negative motivational valence to harmful stimuli.The neurotransmitter acetylcholine has been implied in reward learning and drug addiction. However, the role of cholinergic receptor subtypes in such processes remains elusive. In study IV we investigated the function of muscarinic M4Rs on dopamine D1R expressing neurons and acetylcholinergic neurons, using transgenic mice in various reward-enforced behaviors and in a “waiting”-impulsivity test. Mice lacking M4-receptors from D1-receptor expressing neurons exhibited an escalated reward seeking phenotype towards cocaine and natural reward, in Pavlovian conditioning and an operant self-administration task, respectively. In addition, the M4-D1RCre mice showed impaired waiting impulsivity in the 5-choice-serial-reaction-time-task. On the contrary, mice without M4Rs in acetylcholinergic neurons were unable to learn positive reinforcement to natural reward and cocaine, in an operant runway paradigm and in Pavlovian conditioning. Immediate early gene expression mirrored the behavioral findings arising from M4R-D1R knockout, as cocaine induced cFos and FosB was significantly increased in the forebrain of M4-D1RCre mice, whereas it remained normal in the M4R-ChatCre mice. Our study illustrates that muscarinic M4Rs on specific neural populations, either cholinergic or D1R-expressing, are pivotal for learning processes related to both natural reward and drugs of abuse, with opposing functionality.
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25. |
- Dinér, Peter, 1976, et al.
(författare)
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Preparation of 3-Substituted-1-Isopropyl-1H-pyrazolo 3,4-d pyrimidin-4-amines as RET Kinase Inhibitors
- 2012
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Ingår i: Journal of Medicinal Chemistry. - : American Chemical Society (ACS). - 0022-2623 .- 1520-4804. ; 55:10, s. 4872-4876
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Tidskriftsartikel (refereegranskat)abstract
- A series of 3-substituted-1-isopropyl-1H-pyrazolo[3,4-d]pyrimidin-4-amines have been designed, synthesized, and evaluated as RET protein kinase inhibitors. On the basis of docking results, a small library of pyrazolopyrimidine compounds with an extended hydrophobic side arm was synthesized. The most promising of the compounds (7a) displayed efficient inhibition in vitro and good selectivity when tested on a panel of kinases. Furthermore, 7a inhibited GDNF-induced RET phosphorylation of ERK1/2 in MCF-7 breast cancer cells at concentrations as low as 100 nM.
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26. |
- Bauzá-Thorbrügge, Marco, et al.
(författare)
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Adiponectin stimulates Sca1+CD34−-adipocyte precursor cells associated with hyperplastic expansion and beiging of brown and white adipose tissue
- 2024
-
Ingår i: Metabolism. - : Elsevier. - 0026-0495 .- 1532-8600. ; 151
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Tidskriftsartikel (refereegranskat)abstract
- Background: The adipocyte hormone adiponectin improves insulin sensitivity and there is an inverse correlation between adiponectin levels and type-2 diabetes risk. Previous research shows that adiponectin remodels the adipose tissue into a more efficient metabolic sink. For instance, mice that overexpress adiponectin show increased capacity for hyperplastic adipose tissue expansion as evident from smaller and metabolically more active white adipocytes. In contrast, the brown adipose tissue (BAT) of these mice looks “whiter” possibly indicating reduced metabolic activity. Here, we aimed to further establish the effect of adiponectin on adipose tissue expansion and adipocyte mitochondrial function as well as to unravel mechanistic aspects in this area. Methods: Brown and white adipose tissues from adiponectin overexpressing (APN tg) mice and littermate wildtype controls, housed at room and cold temperature, were studied by histological, gene/protein expression and flow cytometry analyses. Metabolic and mitochondrial functions were studied by radiotracers and Seahorse-based technology. In addition, mitochondrial function was assessed in cultured adiponectin deficient adipocytes from APN knockout and heterozygote mice. Results: APN tg BAT displayed increased proliferation prenatally leading to enlarged BAT. Postnatally, APN tg BAT turned whiter than control BAT, confirming previous reports. Furthermore, elevated adiponectin augmented the sympathetic innervation/activation within adipose tissue. APN tg BAT displayed reduced metabolic activity and reduced mitochondrial oxygen consumption rate (OCR). In contrast, APN tg inguinal white adipose tissue (IWAT) displayed enhanced metabolic activity. These metabolic differences between genotypes were apparent also in cultured adipocytes differentiated from BAT and IWAT stroma vascular fraction, and the OCR was reduced in both brown and white APN heterozygote adipocytes. In both APN tg BAT and IWAT, the mesenchymal stem cell-related genes were upregulated along with an increased abundance of Lineage−Sca1+CD34− “beige-like” adipocyte precursor cells. In vitro, the adiponectin receptor agonist Adiporon increased the expression of the proliferation marker Pcna and decreased the expression of Cd34 in Sca1+ mesenchymal stem cells. Conclusions: We propose that the seemingly opposite effect of adiponectin on BAT and IWAT is mediated by a common mechanism; while reduced adiponectin levels are linked to lower adipocyte OCR, elevated adiponectin levels stimulate expansion of adipocyte precursor cells that produce adipocytes with intrinsically higher metabolic rate than classical white but lower metabolic rate than classical brown adipocytes. Moreover, adiponectin can modify the adipocytes' metabolic activity directly and by enhancing the sympathetic innervation within a fat depot.
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27. |
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28. |
- Delsing, Louise, et al.
(författare)
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Models of the blood-brain barrier using iPSC-derived cells
- 2020
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Ingår i: Molecular and Cellular Neuroscience. - : Elsevier BV. - 1044-7431 .- 1095-9327. ; 107
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Tidskriftsartikel (refereegranskat)abstract
- The blood-brain barrier (BBB) constitutes the interface between the blood and the brain tissue. Its primary function is to maintain the tightly controlled microenvironment of the brain. Models of the BBB are useful for studying the development and maintenance of the BBB as well as diseases affecting it. Furthermore, BBB models are important tools in drug development and support the evaluation of the brain-penetrating properties of novel drug molecules. Currently used in vitro models of the BBB include immortalized brain endothelial cell lines and primary brain endothelial cells of human and animal origin. Unfortunately, many cell lines and primary cells do not recreate physiological restriction of transport in vitro. Human-induced pluripotent stem cell (iPSC)-derived brain endothelial cells have proven a promising alternative source of brain endothelial-like cells that replicate tight cell layers with low paracellular permeability. Given the possibility to generate large amounts of human iPSC-derived brain endothelial cells they are a feasible alternative when modelling the BBB in vitro. iPSC-derived brain endothelial cells form tight cell layers in vitro and their barrier properties can be enhanced through co-culture with other cell types of the BBB. Currently, many different models of the BBB using iPSC-derived cells are under evaluation to study BBB formation, maintenance, disruption, drug transport and diseases affecting the BBB. This review summarizes important functions of the BBB and current efforts to create iPSC-derived BBB models in both static and dynamic conditions. In addition, it highlights key model requirements and remaining challenges for human iPSC-derived BBB models in vitro.
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29. |
- Lindberg, Olle R, et al.
(författare)
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Epidermal growth factor treatment of the adult brain subventricular zone leads to focal microglia/macrophage accumulation and angiogenesis.
- 2014
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Ingår i: Stem cell reports. - : Elsevier BV. - 2213-6711. ; 2:4, s. 440-8
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Tidskriftsartikel (refereegranskat)abstract
- One of the major components of the subventricular zone (SVZ) neurogenic niche is the specialized vasculature. The SVZ vasculature isthought to be important in regulating progenitor cell proliferation and migration. Epidermal growth factor (EGF) is a mitogen witha wide range of effects. When stem and progenitor cells in the rat SVZ are treated with EGF, using intracerebroventricular infusion,dysplastic polyps are formed. Upon extended infusion, blood vessels are recruited into the polyps. In the current study we demonstrate how polyps develop through distinct stages leading up to angiogenesis. As polyps progress, microglia/macrophages accumulate in the polyp core concurrent with increasing cell death. Both microglia/macrophage accumulation and cell death peak during angiogenesis and subsequently decline following polyp vascularization. This model of inducible angiogenesis in the SVZ neurogenic niche suggests involvement of microglia/macrophages in acquired angiogenesis and can be used in detail to study angiogenesis inthe adult brain.
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30. |
- Nowak, Christoph, 1986-
(författare)
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Insulin Resistance : Causes, biomarkers and consequences
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The worldwide increasing number of persons affected by largely preventable diseases like diabetes demands better prevention and treatment. Insulin is required for effective utilisation of circulating nutrients. Impaired responsiveness to insulin (insulin resistance, IR) is a hallmark of type 2 diabetes and independently raises the risk of heart attack and stroke. The pathophysiology of IR is incompletely understood. High-throughput measurement of large numbers of circulating biomarkers may provide new insights beyond established risk factors.The aims of this thesis were to (i) use proteomics, metabolomics and genomics methods in large community samples to identify biomarkers of IR; (ii) assess biomarkers for risk prediction and insights into aetiology and consequences of IR; and (iii) use Mendelian randomisation analysis to assess causality.In Study I, analysis of 80 circulating proteins in 70-to-77-year-old Swedes identified cathepsin D as a biomarker for IR and highlighted a tentative causal effect of IR on raised plasma tissue plasminogen activator levels. In Study II, nontargeted fasting plasma metabolomics was used to discover 52 metabolites associated with glycaemic traits in non-diabetic 70-year-old men. Replication in independent samples of several thousand persons provided evidence for a causal effect of IR on reduced plasma oleic acid and palmitoleic acid levels. In Study III, nontargeted metabolomics in plasma samples obtained at three time points during an oral glucose challenge in 70-year-old men identified associations between a physiologic measure of IR and concentration changes in medium-chain acylcarnitines, monounsaturated fatty acids, bile acids and lysophosphatidylethanolamines. Study IV provided evidence in two large longitudinal cohorts for causal effects of type 2 diabetes and impaired insulin secretion on raised coronary artery disease risk.In conclusion, the Studies in this thesis provide new insights into the pathophysiology and adverse health consequences of IR and illustrate the value of combining traditional epidemiologic designs with recent molecular techniques and bioinformatics methods. The results provide limited evidence for the role of circulating proteins and small molecules in IR and require replication in separate studies and validation in experimental designs.
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31. |
- Turczynska, Karolina, et al.
(författare)
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Regulation of vascular smooth muscle mechanotransduction by microRNAs and L-type calcium channels.
- 2013
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Ingår i: Communicative & Integrative Biology. - : Informa UK Limited. - 1942-0889. ; 6:1, s. 22278-22278
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Tidskriftsartikel (refereegranskat)abstract
- The phenotype of smooth muscle cells is regulated by multiple environmental factors including mechanical forces. Mechanical stretch of mouse portal veins ex vivo has been shown to promote contractile differentiation by activation of the Rho-pathway, an effect that is dependent on the influx of calcium via L-type calcium channels. MicroRNAs have recently been demonstrated to play a significant role in the control of smooth muscle phenotype and in a recent report we investigated their role in vascular mechanosensing. By smooth muscle specific deletion of Dicer, we found that microRNAs are essential for smooth muscle differentiation in response to stretch by regulating CamKIIδ and L-type calcium channel expression. Furthermore, we suggest that loss of L-type calcium channels in Dicer KO is due to reduced expression of the smooth muscle-enriched microRNA, miR-145, which targets CamKIIδ. These results unveil a novel mechanism for miR-145 dependent regulation of smooth muscle phenotype.
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32. |
- Zhang, Yuehui, et al.
(författare)
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Increased uterine androgen receptor protein abundance results in implantation and mitochondrial defects in pregnant rats with hyperandrogenism and insulin resistance. : Deciphering the role of uterine AR in PCOS during early pregnancy
- 2021
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Ingår i: Journal of molecular medicine (Berlin, Germany). - : Springer Science and Business Media LLC. - 1432-1440 .- 0946-2716. ; 99, s. 1427-1446
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Tidskriftsartikel (refereegranskat)abstract
- In this study, we show that during normal rat pregnancy, there is a gestational stage-dependent decrease in androgen receptor (AR) abundance in the gravid uterus and that this is correlated with the differential expression of endometrial receptivity and decidualization genes during early and mid-gestation. In contrast, exposure to 5α-dihydrotestosterone (DHT) and insulin (INS) or DHT alone significantly increased AR protein levels in the uterus in association with the aberrant expression of endometrial receptivity and decidualization genes, as well as disrupted implantation. Next, we assessed the functional relevance of the androgen-AR axis in the uterus for reproductive outcomes by treating normal pregnant rats and pregnant rats exposed to DHT and INS with the anti-androgen flutamide. We found that AR blockage using flutamide largely attenuated the DHT and INS-induced maternal endocrine, metabolic, and fertility impairments in pregnant rats in association with suppressed induction of uterine AR protein abundance and androgen-regulated response protein and normalized expression of several endometrial receptivity and decidualization genes. Further, blockade of AR normalized the expression of the mitochondrial biogenesis marker Nrf1 and the mitochondrial functional proteins Complexes I and II, VDAC, and PHB1. However, flutamide treatment did not rescue the compromised mitochondrial structure resulting from co-exposure to DHT and INS. These results demonstrate that functional AR protein is an important factor for gravid uterine function. Impairments in the uterine androgen-AR axis are accompanied by decreased endometrial receptivity, decidualization, and mitochondrial dysfunction, which might contribute to abnormal implantation in pregnant PCOS patients with compromised pregnancy outcomes and subfertility. KEY MESSAGES: The proper regulation of uterine androgen receptor (AR) contributes to a normal pregnancy process, whereas the aberrant regulation of uterine AR might be linked to polycystic ovary syndrome (PCOS)-induced pregnancy-related complications. In the current study, we found that during normal rat pregnancy there is a stage-dependent decrease in AR abundance in the gravid uterus and that this is correlated with the differential expression of the endometrial receptivity and decidualization genes Spp1, Prl, Igfbp1, and Hbegf. Pregnant rats exposed to 5α-dihydrotestosterone (DHT) and insulin (INS) or to DHT alone show elevated uterine AR protein abundance and implantation failure related to the aberrant expression of genes involved in endometrial receptivity and decidualization in early to mid-gestation. Treatment with the anti-androgen flutamide, starting from pre-implantation, effectively prevents DHT + INS-induced defects in endometrial receptivity and decidualization gene expression, restores uterine mitochondrial homeostasis, and increases the pregnancy rate and the numbers of viable fetuses. This study adds to our understanding of the mechanisms underlying poor pregnancy outcomes in PCOS patients and the possible therapeutic use of anti-androgens, including flutamide, after spontaneous conception.
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33. |
- Greiff, Lennart, et al.
(författare)
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Effects of topical platelet activating factor on the guinea-pig tracheobronchial mucosa in vivo
- 1997
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Ingår i: Acta Physiologica Scandinavica. - 0001-6772. ; 160:4, s. 387-391
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Tidskriftsartikel (refereegranskat)abstract
- Platelet activating factor (PAF) has been reported to produce a variety of airway effects including epithelial damage and increased airway-lung absorption of hydrophilic tracers. The present study examines effects of PAF on the guinea-pig tracheobronchial mucosa in vivo. Vehicle with and without PAF (4.0 and 8.0 nmol) was superfused onto the tracheobronchial mucosa. The levels of 125I-albumin, previously given intravenously, were determined in tracheobronchial lavage fluids as an index of mucosal exudation of plasma. The mucosa was also examined by scanning electron microscopy. In separate animals, 99mTc-DTPA (a low molecular weight, 492 Da, hydrophilic tracer) was superfused onto the mucosal surface through an oro-tracheal catheter, together with vehicle or PAF (8.0 nmol). A gamma camera determined the disappearance rate of 99mTc-DTPA from the airways as an index of mucosal absorption. PAF produced dose-dependent mucosal exudation of plasma up to 20-fold greater than control (P < 0.001). However, PAF did not damage the epithelium and the absorption ability of the airway mucosa was unaffected. The results, in contrast to previous reports, suggest that PAF may not readily damage the airway mucosa even at large exudative doses of the agent. The present finding support the view that the plasticity of the epithelial junctions allows the creation of valve-like paracellular pathways for unidirectional clearance of extravasated plasma into the airway lumen. We suggest that endogenous PAF may participate in first line respiratory defence reactions by causing lumenal entry of bulk plasma without harming the epithelium.
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34. |
- Korsgren, Magnus, et al.
(författare)
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Allergic eosinophil-rich inflammation develops in lungs and airways of B cell-deficient mice
- 1997
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Ingår i: Journal of Experimental Medicine. - 1540-9538. ; 185:5, s. 885-892
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Tidskriftsartikel (refereegranskat)abstract
- Immunoglobulins (Ig), particularly IgE, are believed to be crucially involved in the pathogenesis of asthma and, equally, in allergic models of the disease. To validate this paradigm we examined homozygous mutant C57BL/6 mice, which are B cell deficient, lacking all Ig. Mice were immunized intraperitoneally with 10 micrograms ovalbumin (OVA) plus alum, followed by daily (day 14-20) 30 min exposures to OVA aerosol (OVA/OVA group). Three control groups were run: OVA intraperitoneally plus saline (SAL) aerosol (OVA/SAL group); saline intraperitoneally plus saline aerosol; saline intraperitoneally plus OVA aerosol (n = 6-7). Lung and large airway tissues obtained 24 h after the last OVA or SAL exposure were examined by light microscopy and transmission electron microscopy (TEM). The Ig-deficient mice receiving OVA/ OVA treatment had swollen and discolored lungs and exhibited marked eosinophilia both in large airway subepithelial tissue (49.2 +/- 12.0 cells/mm basement membrane [BM] versus OVA/ SAL control 1.2 +/- 0.3 cells/mm BM; P < 0.001), and perivascularly and peribronchially in the lung (49.3 +/- 9.0 cells/unit area versus OVA/SAL control 2.6 +/- 0.6 cells/unit area; P < 0.001). The eosinophilia extended to the regional lymph nodes. TEM confirmed the subepithelial and perivascular localization of eosinophils. Mucus cells in large airway epithelium increased from 1.5 +/- 0.8 (OVA/SAL mice) to 39.5 +/- 5.7 cells/mm BM in OVA/OVA treated mice (P < 0.001). OVA/SAL mice never differed from the other control groups. Corresponding experiments in wild-type mice (n = 6-7 in each group) showed qualitatively similar but less pronounced eosinophil and mucus cell changes. Macrophages and CD4+ T cells increased in lungs of all OVA/OVA-treated mice. Mast cell number did not differ but degranulation was detected only in OVA/OVA-treated wild-type mice. Immunization to OVA followed by OVA challenges thus cause eosinophil-rich inflammation in airways and lungs of mice without involvement of B cells and Ig.
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35. |
- Persson, Carl, et al.
(författare)
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The mouse trap
- 1997
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Ingår i: Trends in Pharmacological Sciences. - 0165-6147. ; 18:12, s. 465-467
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Tidskriftsartikel (refereegranskat)abstract
- Mouse models of asthma are now being used extensively in drug research. However, the successful unravelling of combinatorial interplays of cells and molecules in the murine airways may not be matched by equally successful demonstrations of an asthma-like pathophysiology. Here, Carl Persson, Jonas Erjefalt, Magnus Korsgren and Frank Sundler discuss the fact that major features of asthma may still need to be demonstrated in the airways of allergic mice.
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36. |
- Persson, Carl, et al.
(författare)
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Unbalanced research
- 2001
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Ingår i: Trends in Pharmacological Sciences. - 0165-6147. ; 22:10, s. 538-541
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Tidskriftsartikel (refereegranskat)
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37. |
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38. |
- Chaudhari, Aditi, et al.
(författare)
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Hepatic deletion of p110α and p85α results in insulin resistance despite sustained IRS1-associated phosphatidylinositol kinase activity
- 2017
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Ingår i: F1000 Research. - : Faculty of 1000 Ltd.. - 2046-1402 .- 1759-796X. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Background: Class IA phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K) is an integral mediator of insulin signaling. The p110 catalytic and p85 regulatory subunits of PI3K are the products of separate genes, and while they come together to make the active heterodimer, they have opposing roles in insulin signaling and action. Deletion of hepatic p110α results in an impaired insulin signal and severe insulin resistance, whereas deletion of hepatic p85α results in improved insulin sensitivity due to sustained levels of phosphatidylinositol (3,4,5)-trisphosphate. Here, we created mice with combined hepatic deletion of p110α and p85α (L-DKO) to study the impact on insulin signaling and whole body glucose homeostasis.Methods: Six-week old male flox control and L-DKO mice were studied over a period of 18 weeks, during which weight and glucose levels were monitored, and glucose tolerance tests, insulin tolerance test and pyruvate tolerance test were performed. Fasting insulin, insulin signaling mediators, PI3K activity and insulin receptor substrate (IRS)1-associated phosphatidylinositol kinase activity were examined at 10 weeks. Liver, muscle and white adipose tissue weight was recorded at 10 weeks and 25 weeks.Results: The L-DKO mice showed a blunted insulin signal downstream of PI3K, developed markedly impaired glucose tolerance, hyperinsulinemia and had decreased liver and adipose tissue weights. Surprisingly, however, these mice displayed normal hepatic glucose production, normal insulin tolerance, and intact IRS1-associated phosphatidylinositol kinase activity without compensatory upregulated signaling of other classes of PI3K.Conclusions: The data demonstrate an unexpectedly overall mild metabolic phenotype of the L-DKO mice, suggesting that lipid kinases other than PI3Ks might partially compensate for the loss of p110α/p85α by signaling through other nodes than Akt/Protein Kinase B.
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39. |
- Deland, Lily, et al.
(författare)
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Novel TPR::ROS1 Fusion Gene Activates MAPK, PI3K and JAK/STAT Signaling in an Infant-type Pediatric Glioma.
- 2022
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Ingår i: Cancer genomics & proteomics. - : Anticancer Research USA Inc.. - 1109-6535 .- 1790-6245. ; 19:6, s. 711-726
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Tidskriftsartikel (refereegranskat)abstract
- Although fusion genes involving the proto-oncogene receptor tyrosine kinase ROS1 are rare in pediatric glioma, targeted therapies with small inhibitors are increasingly being approved for histology-agnostic fusion-positive solid tumors.Here, we present a 16-month-old boy, with a brain tumor in the third ventricle. The patient underwent complete resection but relapsed two years after diagnosis and underwent a second operation. The tumor was initially classified as a low-grade glioma (WHO grade 2); however, methylation profiling suggested the newly WHO-recognized type: infant-type hemispheric glioma. To further refine the molecular background, and search for druggable targets, whole genome (WGS) and whole transcriptome (RNA-Seq) sequencing was performed.Concomitant WGS and RNA-Seq analysis revealed several segmental gains and losses resulting in complex structural rearrangements and fusion genes. Among the top-candidates was a novel TPR::ROS1 fusion, for which only the 3' end of ROS1 was expressed in tumor tissue, indicating that wild type ROS1 is not normally expressed in the tissue of origin. Functional analysis by Western blot on protein lysates from transiently transfected HEK293 cells showed the TPR::ROS1 fusion gene to activate the MAPK-, PI3K- and JAK/STAT- pathways through increased phosphorylation of ERK, AKT, STAT and S6. The downstream pathway activation was also confirmed by immunohistochemistry on tumor tissue slides from the patient.We have mapped the activated oncogenic pathways of a novel ROS1-fusion gene and broadened the knowledge of the newly recognized infant-type glioma subtype. The finding facilitates suitable targeted therapies for the patient in case of relapse.
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40. |
- Fransson, Susanne, 1975, et al.
(författare)
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High level of p37δ-mRNA relative to p110δ-mRNA in neuroblastoma tumors correlates with poor patient survival
- 2013
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Ingår i: Medical Oncology. - : Springer Science+Business Media B.V.. - 1357-0560 .- 1559-131X. ; 30:4
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Tidskriftsartikel (refereegranskat)abstract
- Alterations in the PI3K/Akt pathway, a pathway that promotes proliferation and oncogenic transformation, are common in various cancers. In neuroblastoma, activation of Akt is correlated with aggressive disease although mutations in genes of this pathway are rare. Previous findings include a few mutations in PIK3CD, the gene encoding PI3K catalytic subunit delta, p110delta. We recently reported that an alternatively spliced form of p110delta, called p37delta, had cell proliferative properties and was over-expressed in ovarian and colorectal tumors. Here, we investigated p37delta in neuroblastoma primary tumors of different stages using qPCR (TaqMan) for gene expression analysis (46 samples) and Western blot for protein analysis (22 samples). Elevated levels of both p37delta-mRNA and p110delta-mRNA were detected in metastasizing neuroblastoma tumors compared to normal adrenal gland (P<0.05), and higher expression of p37delta-mRNA relative to p110delta-mRNA in neuroblastoma non-survivor patients compared to survivors (P<0.01). p37delta-Protein levels but not p110delta levels correlated with increased pAKT(T308) and pERK levels. The p37delta-mRNA levels did not correlate with the protein levels, indicating major regulation at the translational/protein level. Deregulation of signaling pathways is a hallmark of cancer development. Here, we show that p37delta, a kinase-dead isoform of the PI3K catalytic subunit p110delta, is over-expressed in neuroblastoma tumors, and that it correlates with the activation of both PI3K/Akt- and RAS-signaling pathways.
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41. |
- Blomgren, Klas, 1963, et al.
(författare)
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Pathological apoptosis in the developing brain
- 2007
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Ingår i: Apoptosis. - : Springer Science and Business Media LLC. - 1360-8185 .- 1573-675X. ; 12:5, s. 993-1010
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Forskningsöversikt (refereegranskat)abstract
- More than half of the initially-formed neurons are deleted in certain brain regions during normal development. This process, whereby cells are discretely removed without interfering with the further development of remaining cells, is called programmed cell death (PCD). The term apoptosis is used to describe certain morphological manifestations of PCD. Many of the effectors of this developmental cell death program are highly expressed in the developing brain, making it more susceptible to accidental activation of the death machinery, e.g. following hypoxia-ischemia or irradiation. Recent evidence suggests, however, that activation and regulation of cell death mechanisms under pathological conditions do not exactly mirror physiological, developmentally regulated PCD. It may be argued that the conditions after e.g. ischemia are not even compatible with the execution of PCD as we know it. Under pathological conditions cells are exposed to various stressors, including energy failure, oxidative stress and unbalanced ion fluxes. This results in parallel triggering and potential overshooting of several different cell death pathways, which then interact with one another and result in complex patterns of biochemical manifestations and cellular morphological features. These types of cell death are here called "pathological apoptosis," where classical hallmarks of PCD, like pyknosis, nuclear condensation and caspase-3 activation, are combined with non-PCD features of cell death. Here we review our current knowledge of the mechanisms involved, with special focus on the potential for therapeutic intervention tailored to the needs of the developing brain.
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42. |
- Chebli, Jasmine
(författare)
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Physiological roles of amyloid precursor protein in vivo - zebrafish as a model
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Amyloid-beta precursor protein (APP) is an evolutionarily conserved transmembrane protein expressed in many different tissues. APP belongs to a gene family consisting of two other APP-like proteins (APLP1 and APLP2). APP has been shown to be involved in biological processes such as neurite outgrowth, neuronal migration, synapse formation and plasticity, and cell-cell interactions. APP also plays a central role in the development of Alzheimer's disease (AD). APP's physiological role has been difficult to understand and despite all research is not yet completely understood. The purpose of this thesis was to study the role of APP during early development with zebrafish as the main model system. We have focused on the zebrafish's Apps and have tried to understand their function with the help of genetic knockout models created using the CRISPR / Cas9 method. We report that appb mutants have weakened cell adhesions that give rise to changes in cell organization. We also report that the appb mutants are smaller but develop into fertile and healthy adult individuals. We also found defects in the formation of the trigeminal ganglia (TG) and that Appb seems to have a role in cell-cell interaction. The more widespread TG also consisted of fewer nerve cells, indicating that Appb promotes nerve cell formation. Furthermore, our studies demonstrate APP expression in cilia on sensory nerve cells and ependymal cells covering the brain chambers. The conserved expression of APP in ependymal cilia in mice and humans suggest an important and preserved function. Zebrafish with mutated App were found to have defects in the formation of both cilia and cerebral ventricles. To identify new signalling pathways through which Appb controls these functions, we studied protein changes in appb mutants using mass spectrometry. These studies highlight changes that both confirm known and suggest new regulations by appb, especially in neural development, cell adhesion and in gene regulation. Finally, we tried to answer the underlying mechanisms behind compensation within the App family. We found that mutations in the app genes activate expression of homologous genes via so-called transcriptional adaptation. In conclusion, the findings reported in this thesis showed that App is implicated already in early cellular adhesion and sensory neuronal differentiation processes and is located to several sensory cilia in vivo. The use of zebrafish as a model organism allowed us to gain valuable knowledge on the physiological roles of App.
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43. |
- Gezelius, Henrik, 1977-, et al.
(författare)
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Conditional genetic labeling of the Renshaw cell population for functional studies of motor control
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The Renshaw cells were among the first interneurons to be characterized in the mammalian spinal cord. Although the basic function of recurrent inhibition to motor neurons, as well as the Renshaw cell connectivity to other neurons have been thoroughly studied, the exact functional role of the Renshaw cells in motor control is still unknown. To further characterize the role of Renshaw cells in spinal cord circuitry, we searched for candidate genes useful in the Cre-loxP system. It has been reported that the mRNA expression of nicotinic cholinergic receptor alpha 2 (Chrna2) is found in a restricted number of cells at the ventral rim in adult rat and mouse spinal cord. In our own search for genes with distinct ventral expression, we noted a similar restricted Chrna2 mRNA expression pattern in the mouse spinal cord at postnatal day (P) 11 and during development at embryonic day 14.5. Based on the fact that the gene product is a cholinergic receptor and the pattern of expression, the neurons are predicted to be Renshaw cells. The possibility that these cells were motor neurons was excluded, since Chrna2 and Vesicular acetylcholine were not co-expressed at P11. To further study this cell population, we have generated a transgenic mouse expressing Cre recombinase (Cre) under the control of the Chrna2 promoter region. To visualize the Cre-expressing cells, the Chrna2-Cre transgenic mouse were bred with a reporter mouse expressing β-galactosidase (β-gal) in the nucleus after loxP excision. As expected, spinal cord β-gal immunoreactivity was observed in a limited number of ventrally located cells in the Cre-bearing offspring. Co-labeling of β-gal with calbindin-28K, a known marker for Renshaw cells, indicated that a majority of the calbindin positive cells were also β-gal positive at the ventral rim where calbindin is specific. In addition, β-gal positive cells without observable calbindin were also detected. It is conceivable that Chrna2 is expressed in additional cells apart from Renshaw cells or that a previously unidentified Renshaw cell subpopulation does not express calbindin. Nonetheless, a mouse with Cre-activity restricted to Chrna2-expressing cells opens the possibility to functionally study a limited population of spinal cord interneurons through genetic techniques, with the ambition to explore the specific role of Renshaw cells in spinal cord circuitry and motor control.
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44. |
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45. |
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46. |
- Nguyen, Tho D. K., et al.
(författare)
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Visualization of Partial Exocytotic Content Release and Chemical Transport into Nanovesicles in Cells
- 2022
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Ingår i: Acs Nano. - : American Chemical Society (ACS). - 1936-0851 .- 1936-086X. ; 16:3, s. 4831-4842
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Tidskriftsartikel (refereegranskat)abstract
- For decades, "all-or-none"and "kiss-and-run"were thought to be the only major exocytotic release modes in cell-to-cell communication, while the significance of partial release has not yet been widely recognized and accepted owing to the lack of direct evidence for exocytotic partial release. Correlative imaging with transmission electron microscopy and NanoSIMS imaging and a dual stable isotope labeling approach was used to study the cargo status of vesicles before and after exocytosis; demonstrating a measurable loss of transmitter in individual vesicles following stimulation due to partial release. Model secretory cells were incubated with 13C-labeled l-3,4-dihydroxyphenylalanine, resulting in the loading of 13C-labeled dopamine into their vesicles. A second label, di-N-desethylamiodarone, having the stable isotope 127I, was introduced during stimulation. A significant drop in the level of 13C-labeled dopamine and a reduction in vesicle size, with an increasing level of 127I-, was observed in vesicles of stimulated cells. Colocalization of 13C and 127I- in several vesicles was observed after stimulation. Thus, chemical visualization shows transient opening of vesicles to the exterior of the cell without full release the dopamine cargo. We present a direct calculation for the fraction of neurotransmitter release from combined imaging data. The average vesicular release is 60% of the total catecholamine. An important observation is that extracellular molecules can be introduced to cells during the partial exocytotic release process. This nonendocytic transport process appears to be a general route of entry that might be exploited pharmacologically. © 2022 The Authors. Published by American Chemical Society.
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47. |
- Rodriguez, Juan, 1983
(författare)
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Targeting apoptosis-inducing factor as a novel therapeutic strategy for preventing perinatal brain injury
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Perinatal complications such as asphyxia can cause brain injuries that are often associated with subsequent neurological deficits. The mechanisms of perinatal brain injury are not fully understood, but mitochondria play a prominent role, not only due to their central function in metabolism, but also because many proteins with apoptosisrelated functions are located in the mitochondrion. Among these proteins, CHCHD4 and apoptosis-inducing factor (AIF) have already been shown to make important contributions to neuronal cell death upon hypoxia-ischemia (HI), but a better understanding of the mechanisms behind these processes is required for the development of improved treatments. By inducing HI in 9-day-old mice, leading to moderate brain injury, we studied these mechanisms from multiple perspectives. First, we determined the effect of chchd4 haploinsufficiency, and we showed that neonatal mice with this genotype experienced less brain damage due to reduced translocation of AIF and Cytochrome c from the mitochondrion. Second, we characterized the role of a newly discovered AIF isoform (AIF2), which is only expressed in the brain and the functions of which are unknown. By using Aif2 knockout mice, we showed that under physiological conditions there is an increase in Aif1 expression (the ubiquitously expressed isoform) due to a compensatory effect of loss of Aif2 expression. As a result, these mice showed a higher degree of brain damage after HI and were more vulnerable to oxidative stress. Third, we used another transgenic mouse in which Aif was overexpressed by knocking in a proviral insertion of Aif, leading to an increased expression of Aif1 without affecting the expression of Aif2. This mouse also showed a higher degree of brain damage and higher levels of oxidative stress. Finally, we used a peptide designed to block the apoptotic function of AIF. The results in young mice showed that the neuroprotective effect of the peptide was greater in male mice than in female mice. In summary, this PhD project has opened new perspectives in the comprehension of the mechanisms by which CHCHD4 and AIF are crucial proteins for brain damage after HI, and it has showed that AIF is a promising therapeutic target for improving outcome after perinatal brain injury.
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48. |
- Vieira, João
(författare)
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Profiling Plasma Metabolite Alterations in Diet-Induced Obesity and Diabetes Using NMR Metabolomics
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Diets rich in saturated fat and sedentary lifestyles markedly contribute to obesity and metabolic syndrome-related diseases, including type 2 diabetes mellitus (T2D). Metabolite profiling plays a pivotal role in understanding these metabolic diseases. This thesis comprises insights from four distinct studies to illuminate metabolic imbalances induced by diet-induced obesity (DIO), covering topics related to the duration of dietary regimens, potential benefits of dietary interventions on the brain and metabolism, and the impact of underlying T2D on post-stroke recovery. Using a combination of proton nuclear magnetic resonance (1H-NMR) spectroscopy and mass spectrometry (MS), study I initially demonstrated the superiority of the combined approach in characterizing the effects of DIO on plasma metabolites. The robustness of this method was further validated in a human cohort, underscoring its translational potential in unravelling metabolic imbalances. In study II, female mice exposed to high-fat diet (HFD) exhibited brain metabolism alterations and memory deficits, which were mitigated by taurine and N-acetylcysteine (NAC) supplementation. These supplements not only ameliorated HFD-induced memory impairment but also elicited distinct effects on metabolic alterations within the hippocampus. Systemically, 1H-NMR metabolomics data in study III revealed that NAC and taurine treatments impacted plasma metabolites. Ultimately, as explored in study IV using 1H-NMR metabolomics, unique metabolite changes in male mice with T2D following transient middle cerebral artery occlusion were reported. Specifically, metabolite changes that link T2D to poor neurological outcomes after stroke were observed. In summary, this thesis underscores the significance of metabolite profiling in elucidating the complexities of metabolic diseases, memory impairment, and post-stroke recovery in DIO mouse models. It also emphasizes the translational character of such findings to human pathophysiology.
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49. |
- Zhu, Changlian, 1964, et al.
(författare)
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X chromosome-linked inhibitor of apoptosis protein reduces oxidative stress after cerebral irradiation or hypoxia-ischemia through up-regulation of mitochondrial antioxidants.
- 2007
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Ingår i: The European journal of neuroscience. - : Wiley. - 1460-9568 .- 0953-816X. ; 26:12, s. 3402-10
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Tidskriftsartikel (refereegranskat)abstract
- We demonstrate that X chromosome-linked inhibitor of apoptosis protein (XIAP) counteracts oxidative stress in two essentially different disease-related models of brain injury, hypoxia-ischemia and irradiation, as judged by lower expression of nitrotyrosine (5-fold) and 4-hydroxy-2-nonenal (10-fold) in XIAP-overexpressing compared with wild-type mice. XIAP overexpression induced up-regulation of at least three antioxidants residing in mitochondria, superoxide dismutase 2, thioredoxin 2 and lysine oxoglutarate reductase. Cytochrome c release from mitochondria was reduced in XIAP-overexpressing mice. Hence, in addition to blocking caspases, XIAP can regulate reactive oxygen species in the brain, at least partly through up-regulation of mitochondrial antioxidants. XIAP-induced prevention of oxidative stress was not secondary to tissue protection because although XIAP overexpression provides tissue protection after hypoxia-ischemia, it does not prevent tissue loss after irradiation. This is a previously unknown role of XIAP and may provide the basis for development of novel protective strategies for both acute and chronic neurodegenerative diseases, where oxidative stress is an integral component of the injury mechanisms involved.
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50. |
- Bally, Marta, 1981, et al.
(författare)
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Norovirus GII.4 Virus-like Particles Recognize Galactosylceramides in Domains of Planar Supported Lipid Bilayers.
- 2012
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Ingår i: Angewandte Chemie International Edition. - : Wiley. - 1433-7851 .- 1521-3773. ; 51:48, s. 12020-4
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Tidskriftsartikel (refereegranskat)abstract
- A sticky situation: Domain-dependent recognition of the glycosphingolipid galactosylceramide by norovirus-like particles (see picture; red/yellow) is shown using supported lipid bilayers (purple) as model membranes. Optimal ligand presentation is found to promote strong binding to GalCer. This presentation can be found at the edges of the glycosphingolipid-enriched domains (green) and binding is repressed in the absence of these domains.
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