| 61. |
- Hagberg, Carolina E, et al.
(författare)
-
Vascular endothelial growth factor B controls endothelial fatty acid uptake.
- 2010
-
Ingår i: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 464:7290, s. 917-21
-
Tidskriftsartikel (refereegranskat)abstract
- The vascular endothelial growth factors (VEGFs) are major angiogenic regulators and are involved in several aspects of endothelial cell physiology. However, the detailed role of VEGF-B in blood vessel function has remained unclear. Here we show that VEGF-B has an unexpected role in endothelial targeting of lipids to peripheral tissues. Dietary lipids present in circulation have to be transported through the vascular endothelium to be metabolized by tissue cells, a mechanism that is poorly understood. Bioinformatic analysis showed that Vegfb was tightly co-expressed with nuclear-encoded mitochondrial genes across a large variety of physiological conditions in mice, pointing to a role for VEGF-B in metabolism. VEGF-B specifically controlled endothelial uptake of fatty acids via transcriptional regulation of vascular fatty acid transport proteins. As a consequence, Vegfb(-/-) mice showed less uptake and accumulation of lipids in muscle, heart and brown adipose tissue, and instead shunted lipids to white adipose tissue. This regulation was mediated by VEGF receptor 1 and neuropilin 1 expressed by the endothelium. The co-expression of VEGF-B and mitochondrial proteins introduces a novel regulatory mechanism, whereby endothelial lipid uptake and mitochondrial lipid use are tightly coordinated. The involvement of VEGF-B in lipid uptake may open up the possibility for novel strategies to modulate pathological lipid accumulation in diabetes, obesity and cardiovascular diseases.
|
|
| 62. |
- Porosk, Ly, et al.
(författare)
-
Endpoint and Kinetic Approaches for Assessing Transfection Efficacy in Mammalian Cell Culture
- 2022. - 3
-
Ingår i: Cell Penetrating Peptides. - New York : Humana Press. - 9781071617519 - 9781071617526 ; , s. 529-545
-
Bokkapitel (refereegranskat)abstract
- The efficacy of transfection reagents and nanoparticles is often assessed by measuring levels of expressed reporter protein. Fluorescence and luminescence based assays provide sensitive, quantifiable and repeatable approaches. The genes expressing reporter protein can be integrated into the cells to create stable reporter cell lines or can be expressed from a transfected plasmid. Green fluorescent protein, luciferase, and secreted alkaline phosphatase are well-established reporters with versatile applications. Monitoring changes in live cells during and after transfection offer opportunities to reveal related mechanisms, efficacy, and bottlenecks of transfection. In this chapter, we describe the experimental setup and considerations for in vitro screening of delivery vectors. This can further be extended to measurements in reporter cell lines.
|
|
| 63. |
- Sivertsson, Louise, et al.
(författare)
-
Hepatic differentiation and maturation of human embryonic stem cells cultured in a perfused three-dimensional bioreactor
- 2013
-
Ingår i: Stem Cells and Development. - : Mary Ann Liebert. - 1547-3287 .- 1557-8534. ; 22:4, s. 581-594
-
Tidskriftsartikel (refereegranskat)abstract
- Drug-induced liver injury is a serious and frequently occurring adverse drug reaction in the clinics and is hard to predict during preclinical studies. Today, primary hepatocytes are the most frequently used cell model for drug discovery and prediction of toxicity. However, their use is marred by high donor variability regarding drug metabolism and toxicity, and instable expression levels of liver-specific genes such as cytochromes P450. An in vitro model system based on human embryonic stem cells (hESC), with their unique properties of pluripotency and self-renewal, has potential to provide a stable and unlimited supply of human hepatocytes. Much effort has been made to direct hESC toward the hepatic lineage, mostly using 2-dimensional (2D) cultures. Although the results are encouraging, these cells lack important functionality. Here, we investigate if hepatic differentiation of hESC can be improved by using a 3-dimensional (3D) bioreactor system. Human ESCs were differentiated toward the hepatic lineage using the same cells in either the 3D or 2D system. A global transcriptional analysis identified important differences between the 2 differentiation regimes, and we identified 10 pathways, highly related to liver functions, which were significantly upregulated in cells differentiated in the bioreactor compared to 2D control cultures. The enhanced hepatic differentiation observed in the bioreactor system was also supported by immunocytochemistry. Taken together, our results suggest that hepatic differentiation of hESC is improved when using this 3D bioreactor technology as compared to 2D culture systems.
|
|
| 64. |
- Umapathy, Ganesh, et al.
(författare)
-
The kinase ALK stimulates the kinase ERK5 to promote the expression of the oncogene MYCN in neuroblastoma
- 2014
-
Ingår i: Science Signaling. - : American Association for the Advancement of Science (AAAS). - 1945-0877 .- 1937-9145. ; 7:349
-
Tidskriftsartikel (refereegranskat)abstract
- Anaplastic lymphoma kinase (ALK) is an important molecular target in neuroblastoma. Although tyrosine kinase inhibitors abrogating ALK activity are currently in clinical use for the treatment of ALK-positive (ALK(+)) disease, monotherapy with ALK tyrosine kinase inhibitors may not be an adequate solution for ALK(+) neuroblastoma patients. Increased expression of the gene encoding the transcription factor MYCN is common in neuroblastomas and correlates with poor prognosis. We found that the kinase ERK5 [also known as big mitogen-activated protein kinase (MAPK) 1 (BMK1)] is activated by ALK through a pathway mediated by phosphoinositide 3-kinase (PI3K), AKT, MAPK kinase kinase 3 (MEKK3), and MAPK kinase 5 (MEK5). ALK-induced transcription of MYCN and stimulation of cell proliferation required ERK5. Pharmacological or RNA interference-mediated inhibition of ERK5 suppressed the proliferation of neuroblastoma cells in culture and enhanced the antitumor efficacy of the ALK inhibitor crizotinib in both cells and xenograft models. Together, our results indicate that ERK5 mediates ALK-induced transcription of MYCN and proliferation of neuroblastoma, suggesting that targeting both ERK5 and ALK may be beneficial in neuroblastoma patients.
|
|
| 65. |
- Jurcevic, Sanja, 1971-, et al.
(författare)
-
Bioinformatics analysis of miRNAs in the neuroblastoma 11q-deleted region reveals a role of miR-548l in both 11q-deleted and MYCN amplified tumour cells
- 2022
-
Ingår i: Scientific Reports. - : Springer Nature. - 2045-2322. ; 12:1
-
Tidskriftsartikel (refereegranskat)abstract
- Neuroblastoma is a childhood tumour that is responsible for approximately 15% of all childhood cancer deaths. Neuroblastoma tumours with amplification of the oncogene MYCN are aggressive, however, another aggressive subgroup without MYCN amplification also exists; rather, they have a deleted region at chromosome arm 11q. Twenty-six miRNAs are located within the breakpoint region of chromosome 11q and have been checked for a possible involvement in development of neuroblastoma due to the genomic alteration. Target genes of these miRNAs are involved in pathways associated with cancer, including proliferation, apoptosis and DNA repair. We could show that miR-548l found within the 11q region is downregulated in neuroblastoma cell lines with 11q deletion or MYCN amplification. In addition, we showed that the restoration of miR-548l level in a neuroblastoma cell line led to a decreased proliferation of these cells as well as a decrease in the percentage of cells in the S phase. We also found that miR-548l overexpression suppressed cell viability and promoted apoptosis, while miR-548l knockdown promoted cell viability and inhibited apoptosis in neuroblastoma cells. Our results indicate that 11q-deleted neuroblastoma and MYCN amplified neuroblastoma coalesce by downregulating miR-548l.
|
|
| 66. |
- Gunja, Sethu Madhava Rao, 1986-
(författare)
-
PARN - A Tale of A de-Tailor : Functional importance of poly(A) degradation in developmental and telomere biology disorders
- 2021
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Poly(A)-specific ribonuclease (PARN) is a eukaryotic 3’-5’exoribonuclease that removes poly(A) tails of many coding and non-coding RNAs. In this thesis, we have studied the physiological role of PARN. We have found that genetic lesions in the human PARN gene are associated with a spectrum of human developmental disorders, including telomere biology disorders (TBDs). TBDs encompass a spectrum of developmental disorders associated with telomere dysfunction and include idiopathic pulmonary fibrosis (IPF), aplastic anaemic (AA), dyskeratosis congenita (DC) and Hoyeraal-Hreidarsson syndrome (HHS). Patients with mono-allelic mutations in PARN suffer from developmental and neurological disorders, whereas bi-allelic mutations are associated with severe disorders, e.g., DC or HHS.Transcriptome analysis revealed that PARN deficient patients were affected in a number of cellular pathways. The most affected were the ribosome/translation, cell-cell adhesion, cell cycle and cell signaling pathways. We also found that PARN deficient patients were defective in the biogenesis of a large number of non-coding RNAs (ncRNAs), including snoRNAs, scaRNAs, miRNAs and rRNAs. Deficiency in snoRNA and rRNA biogenesis correlated with blood disorders and/or bone marrow failure. PARN deficient patients also displayed defects in the maturation of the telomerase RNA component that correlated with telomere shortening.To further understand the physiological role of PARN in TBDs over generations and throughout the life span of an organism, we have established a parn loss-of-function zebrafish model, which recapitulates TBD phenotypes in human patients. In keeping with the human patients, homozygous parn deficient fish exhibited aberrant snoRNA profile, perturbed telomerase RNA maturation and short telomeres. In addition, we found that the zygotic parn mutant fish exhibited a spectrum of developmental defects from early embryogenesis to adult stage. The whole array of disease phenotypes observed in PARN deficient human patients and the parn loss-of-function zebrafish model indicate that PARN has essential roles in regulating growth and development throughout the life of an organism.
|
|
| 67. |
- Molinaro, Angela, et al.
(författare)
-
Insulin-Driven PI3K-AKT Signaling in the Hepatocyte Is Mediated by Redundant PI3Kα and PI3Kβ Activities and Is Promoted by RAS.
- 2019
-
Ingår i: Cell Metabolism. - : Elsevier BV. - 1550-4131 .- 1932-7420. ; 29:6, s. 1400-
-
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 be dosed below their hyperglycemic threshold to achieve isoform selectivity.
|
|
| 68. |
- Mondal, Tanmoy, 1981, et al.
(författare)
-
Sense-antisense lncRNA pair encoded by locus 6p22.3 determines neuroblastoma susceptibility via the USP36-CHD7-SOX9 regulatory axis
- 2018
-
Ingår i: Cancer Cell. - : Elsevier BV. - 1535-6108 .- 1878-3686. ; 33:3, s. 417-434.e7
-
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.
|
|
| 69. |
- Tulha, Joana, et al.
(författare)
-
Physical, genetic and functional interactions between the eisosome protein Pil1 and the MBOAT O-acyltransferase Gup1
- 2021
-
Ingår i: FEMS Yeast Research. - : Oxford University Press (OUP). - 1567-1356 .- 1567-1364. ; 21:1
-
Tidskriftsartikel (refereegranskat)abstract
- The Saccharomyces cerevisiae MBOAT O-acyltransferase Gup1 is involved in many processes, including cell wall and membrane composition and integrity, and acetic acid-induced cell death. Gup1 was previously shown to interact physically with the mitochondrial membrane VDAC (Voltage-Dependent Anion Channel) protein Por1 and the ammonium transceptor Mep2. By co-immunoprecipitation, the eisosome core component Pil1 was identified as a novel physical interaction partner of Gup1. The expression of PIL1 and Pil1 protein levels were found to be unaffected by GUP1 deletion. In gup1 cells, Pil1 was distributed in dots (likely representing eisosomes) in the membrane, identically to wt cells. However, gup1 cells presented 50% less Pil1-GFP dots/eisosomes, suggesting that Gup1 is important for eisosome formation. The two proteins also interact genetically in the maintenance of cell wall integrity, and during arsenite and acetic acid exposure. We show that Δgup1 Δpil1 cells take up more arsenite than wt and are extremely sensitive to arsenite and to acetic acid treatments. The latter causes a severe apoptotic wt-like cell death phenotype, epistatically reverting the gup1 necrotic type of death. Gup1 and Pil1 are thus physically, genetically and functionally connected.
|
|
| 70. |
- Nilsson, Linnéa
(författare)
-
Studies on the Role of Apoptosis in Kidney Diseases
- 2019
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Apoptosis is one of the most common types of cell death. Under physiological conditions, it plays an essential role in removal of damaged and potentially harmful cells. Excessive apoptosis has however been linked to a number of diseases including proteinuric kidney disease and DKD, and is believed to enhance the disease progression. Albuminuria and hyperglycemia are common symptoms of these diseases and albumin and high glucose have been seen to trigger intrinsic apoptosis in renal cells. Ouabain, a cardiotonic steroid, has previously been identified as an antiapoptotic agent that in subsaturating concentrations protect from intrinsic apoptosis. The mechanism of the protective effect of ouabain is still not fully understood and it remains to be concluded whether ouabain can protect from albumin and/or glucotoxic-triggered apoptosis.In study I we investigated the protective effects of ouabain in albumin-exposed primary rat PTC and podocytes and in the proteinuric kidney disease animal model passive Heymann nephritis. By reestablishing the balance between the proapoptotic protein BAX and the antiapoptotic protein BCL-XL, ouabain averted the albumin-triggered apoptosis in vitro and in vivo and protected from podocytes loss and glomerular-tubular disconnection.In study II we investigated the relationship between the glucose transporters renal cells express and their susceptibility of glucotoxic-triggered apoptosis. We identified the SGLT expressing cells, PTC and MC, to be more susceptible to high glucose-induced apoptosis than cells without SGLT. The apoptosis was mediated by BAX and BCL-XL imbalance and mitochondrial dysfunction, and was abolished when treated with ouabain or SGLT inhibitors. Podocytes, which lack SGLT, did not respond to short-term high glucose exposure.In study III we used super-resolution microscopy to investigate at which stage of the apoptotic process ouabain start to intervene. Ouabain interfered early in the apoptotic process, where it prevented activation of the sensitizer protein BAD. This allowed BCL-XL to avert BAX activation and translocation to mitochondria and thereby protected from mitochondrial dysfunction and apoptosis.In study IV we investigated differentially expressed genes between renal cortex and primary short-term PTC cultures and between PTC exposed to control and high glucose. The mRNA expression level of most genes was significantly up- or downregulated in PTC compared to renal cortex, with the biggest differences in mitochondria and metabolism related genes. Early state glucotoxicity did not significantly alter mRNA expression levels in PTC.
|
|
