111.
Grunberg, J. R., et al.
(författare)
CCN5/WISP2 and metabolic diseases
2018
Ingår i: Journal of Cell Communication and Signaling. - : Springer Science and Business Media LLC. - 1873-9601 .- 1873-961X. ; 12:1, s. 309-318
Tidskriftsartikel (refereegranskat) abstract
Obesity and type 2 diabetes increase worldwide at an epidemic rate. It is expected that by the year 2030 around 500 million people will have diabetes; predominantly type 2 diabetes. The CCN family of proteins has become of interest in both metabolic and other common human diseases because of their effects on mesenchymal stem cell (MSCs) proliferation and differentiation as well as being important regulators of fibrosis. We here review current knowledge of the WNT1 inducible signaling pathway protein 2 (CCN5/WISP2). It has been shown to be an important regulator of both these processes through effects on both the canonical WNT and the TGF ss pathways. It is also under normal regulation by the adipogenic commitment factor BMP4, in contrast to conventional canonical WNT ligands, and allows MSCs to undergo normal adipose cell differentiation. CCN5/WISP2 is highly expressed in, and secreted by, MSCs and is an important regulator of MSCs growth. In a transgenic mouse model overexpressing CCN5/WISP2 in the adipose tissue, we have shown that it is secreted and circulating in the blood, the mice develop hypercellular white and brown adipose tissue, have increased lean body mass and enlarged hypercellular hearts. Obese transgenic mice had improved insulin sensitivity. Interestingly, the anti-fibrotic effect of CCN5/WISP2 is protective against heart failure by inhibition of the TGF ss pathway. Understanding how CCN5/WISP2 is regulated and signals is important and may be useful for developing new treatment strategies in obesity and metabolic diseases and it can also be a target in regenerative medicine.
112.
Gupta, Swarnim, 1984, et al.
(författare)
The development of a novel ferric phytate compound for iron fortification of bouillons (part I)
2020
Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322 .- 2045-2322. ; 10:1
Tidskriftsartikel (refereegranskat) abstract
In a series of two studies, we report the development (this study) and evaluation (part II) of a novel ferric phytate compound designed as a condiment iron fortificant. Condiments are used as iron fortification vehicles to reduce the prevalence of iron deficiency. The challenge for iron fortificants in e.g. a bouillon matrix is to avoid undesired sensory effects and to ensure a reasonable cost. We added phytic acid to chelate iron, and hydrolysed protein to counteract the inhibiting effect of phytic acid on iron bioaccessibility. We characterised four novel ferric phytate compounds, destabilised by hydrolysed plant protein or amino acids. Colour stability of fortified bouillons with ferric phytate compounds was superior to bouillons fortified with ferrous sulfate. The iron-phytate-hydrolysed corn protein compound (Fe-PAHCP) resulted in highest cellular ferritin induction in Caco-2 cells, in both vegetable (36.1 ± 13.40 ng/mg protein) and chicken (73.9 ± 19.93 ng/mg protein) bouillon matrices as observed in the human Caco-2/ HepG2 cell model. Iron uptake (as estimated by ferritin production) from the Fe-PA-HCP compound was about 55% (chicken bouillon) and 66% (vegetable bouillon) of the iron uptake from ferrous sulfate. Based on this study, the Fe-PA-HCP compound was chosen for further evaluation (part II).
113.
Gustafsson, Ann-Sofie, 1982-
(författare)
Radiation response in human cells : DNA damage formation, repair and signaling
2015
Doktorsavhandling (övrigt vetenskapligt/konstnärligt) abstract
Ionizing radiation induces a range of different DNA lesions. In terms of mutation frequency and mammalian cell survival, the most critical of these lesions is the DNA double-strand break (DSB). DSB left unrepaired or mis-repaired may result in chromosomal aberrations that can lead to permanent genetic changes or cell death. The complexity of the DNA damage and the capacity to repair the DSB will determine the fate of the cell. This thesis focuses on the DNA damage formation, repair and signaling after irradiation of human cells.Radiation with high linear energy transfer (LET) produces clustered damaged sites in the DNA that are difficult for the cell to repair. Within these clustered sites, non-DSB lesions are formed that can be converted into a DSB and add to the damage complexity and affect DSB repair and the measurement. Heat-labile sites in DNA are converted into DSB at elevated temperatures. We show that heat-released DSB are formed post-irradiation with high-LET ions and increase the initial yield of DSB by 30%-40%, which is similar to yields induced by low-LET radiation.DNA-PKcs, a central player in non-homologous end-joining (NHEJ), the major mammalian DSB repair pathway, has been found to be both up- and downregulated in different tumor types. In Paper II we show that low levels of DNA-PKcs lead to extreme radiosensitivity but, surprisingly, had no effect on the DSB repair. However, the fraction of cells in G2/M phase increased two-fold in cells with low levels of DNA-PKcs. The study continued in Paper IV, where cells were synchronized to unmask potential roles of DNA-PKcs in specific cell cycle phases. Irradiation of DNA-PKcs suppressed cells in the G1/S phase caused a delay in cell cycle progression and an increase in accumulation of G2 cells. Further, these cells showed defects in DNA repair, where a significant amount of 53BP1 foci remained after 72 h. This further strengthens the hypothesis that DNA-PKcs has a role in regulation of mitotic progression.Several cellular signaling pathways are initiated in response to radiation. One of these downstream signaling proteins is AKT. We identified an interaction between DNA-PKcs and AKT. Knockouts of both AKT1 and AKT2 impaired DSB rejoining after radiation and low levels of DNA-PKcs increased radiosensitivity and decreased DNA repair further.
114.
Hedjazifar, Shahram, 1975
(författare)
The mechanism of integrin inactivation and cell signalling induced by c-erbB2, an oncogenic growth factor receptor
2006
Doktorsavhandling (övrigt vetenskapligt/konstnärligt) abstract
Overexpression of the oncogenic growth factor receptor, c-erbB2, is linked with poor prognosis in breast carcinomas and is used as a target for therapeutic strategies. To elucidate the mechanism underlying the tumorigenic action of an elevated c-erbB2 level, leading to homodimerization and activation, we have used an inducible system where a hybrid receptor consisting of the cytoplasmic and transmembrane domains of c-erbB2 fused to the extracellular domain of the trkA NGF receptor has been stably transfected into an immortalized mammary epithelial cell line. In the transfectants, the homodimerization and activation of c-erbB2 is induced by adding NGF. Using this system, we have examined the intracellular signalling induced by c-erbB2 homodimerization with respect to changes in cell-matrix interaction and cell morphology, events that are essential for development of metastasis in tumours. Analyses of the spreading and adhesive ability of the cells on collagen revealed that an early effect of c-erbB2 homodimer signalling was to inhibit the function of the Ñ2 Ò1 integrin, a collagen-binding adhesion molecule. We could further demonstrate that the major mechanism of Ñ2 Ò1 integrin inactivation is due to extracellular conformational change, and that it was mediated by several parallel signalling pathways downstream of c-erbB2 when monitored using pharmacological inhibitors, transient transfections, and conformational sensitive antibodies. These signalling pathways were MEK ERK kinase 1/2 (MEK 1/2), Protein Kinase B (PKB) and Rho pathways, where PKB contributes to suppression of adhesion and inactivation of extracellular conformation of Ò1 integrin through cytoskeletal rearrangements. We also could show that another signal protein, integrin-linked kinase (ILK), inhibits adhesion upon c-erbB2 homodimer signalling. However in contrast to other signalling pathways involved, ILK was not able to change integrin conformation. ILK is implicated in regulation of several cellular processes such as cell adhesion, cell morphology and cell motility; moreover it can promote cell cycle progression and tumour formation. An approach to clarify the role of ILK in suppression of cell-matrix adhesion downstream of c-erbB2, is to elucidate the mechanism underlying ILK activation when c-erbB2 homodimerization is induced. Using in vitro kinase assays and RNAi technique we could demonstrate that c-erbB2 induced mode of ILK activation is regulated by a SH2/SH3 domain containing adaptor protein, Nck-2, that was further shown to interact with c-erbB2, when homodimerized. Nck-2 may be important in ILK mediated inhibition of adhesion, downstream of c-erbB2 and may act as a possible link between ILK and cerbB2 in carcinogenesis, upon long-term activation of this receptor. In summary, this thesis presents new findings about inside-out regulation of integrin-mediated adhesion, which gives in addition a better insight into the mechanism behind c-erbB2 induced suppression of cell-matrix interaction, presumably an early event in carcinogenesis induced by overexpression of this oncoprotein.
115.
Heldin, Johan
(författare)
Identification and Characterization of Proteins and MicroRNAs that Modulate Receptor Signaling, Vesicular Trafficking and Cell Migration in Vascular Cells
2014
Doktorsavhandling (övrigt vetenskapligt/konstnärligt) abstract
Blood vessels deliver nutrients and oxygen to tissues. Importantly, the functions and growth of blood vessels are commonly altered in disease. The inside of all blood vessels are lined with endothelium, a thin specialized layer of endothelial cells that separate the blood from other tissues. This thesis deals with the identification and functional characterization of proteins and microRNAs that have key roles as modulators of growth factor signaling and directed cell migration of endothelial cells and other vascular cells.A previously uncharacterized protein of the exocyst complex, Exocyst complex component 3-like 2 (ExoC3L2) was identified and shown to be highly expressed in endothelial cells of sprouting vessels. Suppression of ExoC3L2 resulted in reduced VEGF-A signaling together with reduced chemotaxis in response to VEGF-A gradients. VEGF-A-signaling via its receptor VEGFR-2 is thus modulated by the exocyst complex and ExoC3L2.Expression profiling of highly vascularized tissues were used to identify several microRNAs selectively expressed in blood vessels. miR-145, targeting the transcription factor Fli1, was shown to be expressed in pericytes and mural cells. Elevated levels of miR-145 reduced chemotaxis of both endothelial cells and fibroblasts in response to growth factor gradients. miR-145 depletion in fibroblasts was shown to inhibit chemotaxis in response to PDGF-BB.The guanine nucleotide exchange factor FGD5 was shown to be selectively expressed in endothelial cells and to regulate Cdc42 activity. FGD5 was shown to regulate the turnover of activated VEGF-receptors. Suppression of FGD5 impaired endothelial cell chemotaxis, suggesting that FGD5 is required for efficient and sustained VEGF-A signaling.Inactivation of RhoD, a regulator of endosomal trafficking, resulted in an increased pool of acetylated and stable microtubules. Knockdown of RhoD in human fibroblasts resulted in a loss of cell polarity. A link between PDGFR-β and RhoD was implicated by the finding that PDGF-BB was shown to trigger formation of GTP-bound RhoD. Chemotaxis towards PDGF-BB was severely inhibited in cells with reduced RhoD expression, suggesting a role for RhoD in chemotaxis via its regulation of microtubule dynamics.
116.
Holmén Larsson, Jessica, 1971
(författare)
O-glycosylation of intestinal and respiratory mucins in health and disease
2006
Doktorsavhandling (övrigt vetenskapligt/konstnärligt) abstract
Mucins are large glycoproteins with a diverse O-glycosylation constituting up to 80% of the total mucin mass. The mucus layer covering the epithelial cells of the gastrointestinal and respiratory tract is largely made up of gel-forming mucins. MUC2 is the main gel-forming mucin in the intestinal tract and its O-glycosylation has been studied in health and disease in this thesis. Glycosylation alterations in relation to infection/inflammation in diseases affecting the mucosa as Cystic Fibrosis and Ulcerative colitis, have been identified. The glycosylation of mouse small intestinal mucins was studied during an infection cycle induced by the parasite Nippostrongylus brasiliensis. The O-linked oligosaccharides were released from the guanidinium chloride insoluble mucins and structurally characterized by gas chromatography/mass spectrometry. Two oligosaccharides containing blood group H-type epitopes (Fuc Ñ1-2Gal-) were transiently expressed with a peak at day 6. Northern blot analysis on total RNA showed a transient expression at day 4-6 of the Fut2 gene encoding the Fuc Ñ1-2 fucosyltransferase synthesizing the H-epitope. Additional oligosaccharides with the common structure HexNAc-Gal-3GalNAcol were transiently expressed with a peak at day 10. Secretor-negative women have an increased risk for recurrent vaginitis caused by C. albicans. A model of this disease is the Fut2-LacZ-null mice lacking the Fut2 enzyme. The aim of the study was to determine if the lack of Fut2 affected the glycosylation of mucins in the gastrointestinal tract. Mass spectrometry showed a complete loss of terminal fucosylation on the O-linked oligosaccharides of the colonic insoluble mucins in the mutant mice. Inoculation by gastric lavage with C. albicans showed no differences in colonization between mouse genotypes. The results suggest that the increased risk of recurrent vaginitis in secretor negative women, is not due to less intestinal colonization.There has been a long time controversy in Cystic Fibrosis (CF) research regarding the observed changes in mucin glycosylation. Are they due to an absent CFTR channel or secondary effects due to infection/ inflammation? We addressed this question by studying mucins secreted by non-infected second passage primary human bronchial epithelial (HBE) cell cultures. The O-linked oligosaccharides, released from purified non-CF and CF mucins, showed large inividual variations, but no significant differences between the two groups. To conclude, no differences in the mucin O-glycan repertoire was found, suggesting that observed CF glycosylation alterations are due to infection/inflammation. Novel proteomic and glycoproteomic methods were used to study sigmoid colon biopsies from active and inactive ulcerative colitis patients and compared to controls. In a total of 50 patients, the monomeric form of MUC2 was semiquantified and 5-10-fold individual differences in MUC2 amounts were observed. The O-glycosylation of colonic MUC2 was studied with a high sensitivity nanoLC/MS setup, developed in-house. More than 50 O-linked oligosaccharides were identified and quantified. Some of the glycan structures have not been characterized previously. A subpopulation of patients with ulcerative colitis showed an accumulation of some precursor glycans and a decrease of complex glycans. This glycan pattern was especially frequent among the active ulcerative colitis patients.
117.
Ihse, Elisabet, 1977-, et al.
(författare)
Amyloid fibrils with fragmented ATTR may be the rule in non-Val30Met ATTR amyloidosis
Annan publikation (övrigt vetenskapligt/konstnärligt) abstract
The clinical phenotype of familial ATTR amyloidosis depends to some extent on the particular mutation, but differences exist also within mutations. We have previously described that two types of amyloid fibril compositions exist among Swedish ATTRV30M amyloidosis patients, one consisting of a mixture of intact and fragmented ATTR (type A) and one composed of only intact ATTR (type B). Patients with type A fibrils have a late age of onset and signs of cardiomyopathy, while patients with type B fibrils have an early onset and much less myocardial involvement. The present study aimed to determine if the correlation between fibril type and clinical phenotype is true for familial amyloidosis in general. Cardiac and/or adipose tissue from 48 patients carrying 21 different non-TTRV30M mutations were examined, as well as 7 non-Swedish ATTRV30M patients. Fibril type was determined with western blotting and compared to the patients´ age of onset and degree of cardiomyopathy. Non-Swedish V30M patients showed the same correlation as described for Swedish V30M patients, with fibrils of only full-length ATTR (type B) linked to less myocardial involvement. In contrast, all patients with non-V30M mutations had a fibril composition with ATTR fragments (type A). Some of these patients had onset of disease at young age. The vast majority had increased thickness of left cardiac ventricle, but a few individuals had values within normal limits. This study shows that a fibril composition with fragmented ATTR is very common in ATTR amyloidosis. It also suggests that fibrils composed of only full-length ATTR is an exception, perhaps only found among young ATTRV30M amyloidosis patients.
118.
Ihse, Elisabet, 1977-
(författare)
Two Types of Fibrils in ATTR Amyloidosis : Implications for Clinical Phenotype and Treatment Outcome
2011
Doktorsavhandling (övrigt vetenskapligt/konstnärligt) abstract
Systemic amyloidoses are a group of lethal diseases where proteins aggregate into fibrillar structures, called amyloid fibrils, that deposits throughout the body. Transthyretin (TTR) causes one type of amyloidosis, in which the aggregates mainly infiltrate nervous and cardiac tissue. Almost a hundred different mutations in the TTR gene are known to trigger the disease, but wild-type (wt) TTR is also incorporated into the fibrils, and may alone form amyloid. Patients with the TTRV30M mutation show, for unknown reasons, two clinical phenotypes. Some have an early onset of disease without cardiomyopathy while others have a late onset and cardiomyopathy. It has previously been described that amyloid fibrils formed from TTRV30M can have two different compositions; either with truncated molecules beside full-length TTR (type A) or only-full-length molecules (type B). In this thesis, the clinical importance of the two types of amyloid fibrils was investigated. We found that the fibril composition types are correlated to the two clinical phenotypes seen among TTRV30M patients, with type A fibrils present in late onset patients and type B fibrils in early onset patients. The only treatment for hereditary TTR amyloidosis has been liver transplantation, whereby the liver producing the mutant TTR is replaced by an organ only producing wt protein. However, in some patients, cardiac symptoms progress post-transplantationally. We demonstrated that the propensity to incorporate wtTTR differs between fibril types and tissue types in TTRV30M patients, with cardiac amyloid of type A having the highest tendency. This offers an explanation to why particularly cardiac amyloidosis develops after transplantation, and suggests which patients that are at risk for such development. By examining patients with other mutations than TTRV30M, we showed that, in contrast to the general belief, a fibril composition with truncated TTR is very common and might even be the general rule. This may explain why TTRV30M patients often have a better outcome after liver transplantation than patients with other mutations. In conclusion, this thesis has contributed with one piece to the puzzle of understanding the differences in clinical phenotype and treatment response between TTR amyloidosis patients, by demonstrating corresponding differences at a molecular level.
119.
Karlsson, Oskar, et al.
(författare)
Detection of long non-coding RNAs in human breastmilk extracellular vesicles : Implications for early child development.
2016
Ingår i: Epigenetics. - : Informa UK Limited. - 1559-2294 .- 1559-2308. ; 11:10, s. 721-729
Tidskriftsartikel (refereegranskat) abstract
Breastmilk has many documented beneficial effects on the developing human infant, but the components of breastmilk that influence these developmental pathways have not been fully elucidated. Increasing evidence suggests that non-coding RNAs encapsulated in extracellular vesicles (EVs) represent an important mechanism of communication between the mother and child. Long non-coding RNAs (lncRNAs) are of particular interest given their key role in gene expression and development. However, it is not known whether breastmilk EVs contain lncRNAs. We used qRT-PCR to determine whether EVs isolated from human breastmilk contain lncRNAs previously reported to be important for developmental processes. We detected 55 of the 87 screened lncRNAs in EVs from the 30 analyzed breastmilk samples, and CRNDE, DANCR GAS5, SRA1 and ZFAS1 were detected in >90% of the samples. GAS5, SNHG8 and ZFAS1 levels were highly correlated (Spearman's rho>0.9; P<0.0001), which may indicate that the loading of these lncRNAs into breastmilk EVs is regulated by the same pathways. The detected lncRNAs are important epigenetic regulators involved in processes such as immune cell regulation and metabolism. They may target a repertoire of recipient cells in offspring and could be essential for child development and health. Further experimental and epidemiological studies are warranted to determine the impact of breastmilk EV-encapsulated lnRNAs in mother to child signaling.
120.
Kerje, Susanne, et al.
(författare)
Is low molecular hyaluronan an early indicator of disease in avian systemic sclerosis?
2016
Ingår i: Connective Tissue Research. - : Taylor & Francis. - 0300-8207 .- 1607-8438. ; 57:5, s. 337-346
Tidskriftsartikel (refereegranskat) abstract
AIM OF THE STUDY: To further elucidate the pathogenesis of systemic sclerosis (SSc) an experimental avian model was used. University of California at Davies line 200-chicken (UCD-200) spontaneously develops a SSc like disease that has most features of human SSc with vascular effects, inflammation, autoimmunity and fibrosis. The first signs of disease in UCD-200 are swelling and ischemic lesions of the comb, a tissue containing high amounts of the glycosaminoglycan hyaluronan. The aim was to evaluate inflammatory and fibrotic processes of the disease with regard to the molecular weight of hyaluronan.MATERIAL AND METHODS: Comb biopsies from UCD-200 and healthy White Leghorn (WL) chickens as controls at different ages were studied with histochemical localization of hyaluronan, hyaluronidase 1, CD3, IgY and collagen I and III. Hyaluronan molecular weight distribution was estimated with gas phase electrophoretic analysis.RESULTS: At 2 days of age hyaluronan was visualized in UCD-200 at the dermal part of the comb with no simultaneous staining of Hyal-1. In adult UCD-200 the comb skin was almost totally devoid of hyaluronan compared to WL of the same age. An increase of low molecular weight (LMW) hyaluronan was detected in comb tissue from UCD-200 at 1 day, 1, 2, 4 weeks in contrast to adult animals.CONCLUSIONS: An early inflammatory process involving LMW hyaluronan was confirmed as a possible profibrotic process. This indicates that hyaluronan might be an important participant in early inflammatory events of SSc in UCD-200 chicken and that disappearance of hyaluronan in skin predisposes to fibrosis.
