Phosphorylation of PLIN5 is dynamically regulated in mice, required for IRS2 expression in the male mice liver, but dispensable for PGC1a target genes previously associated with PLIN5
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA1152100 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR30361327_1.fastq.gz | Fastqsanger.gz | |||
| SRR30361327_2.fastq.gz | Fastqsanger.gz | |||
| SRR30361328_1.fastq.gz | Fastqsanger.gz | |||
| SRR30361328_2.fastq.gz | Fastqsanger.gz | |||
| SRR30361329_1.fastq.gz | Fastqsanger.gz |
Items per page: 5 1 - 5 of 16 |
Similar Datasets
Project description:Perilipin 5 (PLIN5) is a lipid droplet (LD) protein highly expressed in tissues that are active in fatty acid oxidation such as the heart, oxidative muscle, the liver, and brown adipocytes. PLIN5 shares homology with PLIN1: it prevents lipolysis in basal state but promotes lipolysis upon the activation of protein kinase A (PKA). In vitro studies expressing exogenous PLIN5 have shown that PLIN5 is phosphorylated at serine 155 (S155) by PKA. In addition to the regulation of lipolysis, phosphorylation of PLIN5 at S155 has been shown to regulate expression of genes in lipid metabolism, mitochondria, inflammation, and autophagy by traveling to the nucleus and activating peroxisome proliferater-activated-receptor-gamma-coactivator-1-α (PGC1a). However, a role of PLIN5 phosphorylation at S155 has been primarily studied in vitro with exception of a few studies expressing exogenous wild type (WT) and phosphorylation resistant PLIN5 (S155A) in the heart or the liver of mice. Here, we aim to determine the extent of endogenous PLIN5 phosphorylation in vivo and its role in the regulation of lipid metabolism and gene expression in the liver using PLIN5 S155A knock in mice (S155A). First, we enriched LDs from the liver of fed and fasted C57BL6 WT mice to measure non-phosphorylated and S155 phosphorylated PLIN5 by LC-MS/MS. While peak area of non-phosphorylated PLIN5 was similar, S155 phosphorylation was increased in the liver from fasted mice compared with fed mice confirming that endogenous PLIN5 is phosphorylated at S155 when PKA is activated during fasting (3.0-fold increase, p<0.05). Then, we utilized Phos-tag gel as a simple method to assess the extent of PLIN5 phosphorylation. When the heart and the liver from WT and S155A mice were run on Phos-tag gel and immunoblotted for PLIN5, a phosphorylated band was significantly reduced in S155A tissues confirming that S155 is the dominant phosphorylation site in vivo. Next, we assessed phenotypes of S155A mice to gauge the necessity of S155 phosphorylation for metabolism and gene expression in the fasted liver. For the glucose tolerance test, 4-month-old male and female S155A mice showed no differences, but one year-old S115A males had impaired glucose tolerance. There was not a significant difference in weight or blood glucose in fasted young S155A females compared to wild type, but aged male S155A mice had a higher fasted blood glucose (p<0.05) without difference in weight. There was not a significant difference in serum insulin, triglycerides (TG), beta-hydroxybutyrate, or non-esterified fatty acids levels between WT and S155A mice in either males or females. The liver TG contents did not differ between WT and S155A mice of both genders. When qPCR tested the liver of fasted WT and S155A mice, Pgc1a target genes upregulated by fasting and proposed to be regulated by PLIN5 phosphorylation did not show striking difference in expression. Pgc1a, Ppara, Acot1, Pdk4, and Ascl1 expression was similar between WT and S155A liver of fasted mice. Cpt1a and G6pc showed trend of reduction in S155A liver but did not reach statistical significance (n=5 to 7). Inflammation markers such as IL1b and Ccl2 did not differ between WT and S155A liver of fasted mice either. We performed unbiased RNA sequencing of WT and S155A liver from fasted female mice to identify genes differentially regulated by phosphorylation of PLIN5 at S155. There were limited number of genes differentially expressed in S155A female livers with 3 genes < 0.05 for adjusted p value. Interestingly, RNA seq identified insulin receptor substrate 1 (Irs1) as a gene with significantly decreased expression in the liver of female S155A mice (Log2 fold change -0.74, adjusted p value 0.003). The difference was confirmed in qPCR of fasted liver for the female mice (p<0.05), but not for males. Interestingly, insulin receptor substrate 2 (Irs2) measured by qPCR was not different in the liver of female S155A mice but was reduced in male S155A mice (p<0.05). The reduction of IRS2 protein in the liver of S155A male mice was confirmed by Western blot. In conclusion, endogenous PLIN5 in the liver increases phosphorylation at S155 upon fasting in mice. However, the loss of S155 phosphorylation does not affect serum lipids or liver TG. Also, changes in the expression of PGC1a target genes were subtle in the liver of fasted S155A mice compared with WT mice indicating that the loss of PLIN5 S155 phosphorylation can be readily compensated by other mechanisms. Unexpectedly, IRS2 showed decreased expression in the liver of S155A male mice that may explain glucose intolerance in aged male mice. Thus, PLIN5 phosphorylation may impact the insulin signaling in the liver by supporting IRS2 expression in male mice.
2024-08-26 | GSE275608 | GEO
Project description:Relative beta cell deficit and increased beta cell apoptosis are hallmarks of type 2 diabetes (T2D). The Insulin/Insulin Growth Factor (Igf) signaling pathway is an established regulator of beta cell survival and is found downregulated in human T2D islets. The Insulin Receptor Substrate 2 (Irs2) plays a central role in the coordination of this pathway in beta cells. Thus, Irs2 knockout mice (Irs2 -/-) exhibit increased beta cell apoptosis that leads to a progressive decline of beta cell mass and hyperglycaemia. In this study, we sought to determine whether the anti-diabetic compound sodium tungstate could prevent the onset of diabetes in Irs2 -/- mice. Oral administration of tungstate resulted in an overall improvement in whole-body glucose tolerance in Irs2 -/- mice which correlated with increased beta cell mass. Enhanced beta cell mass was due to a dramatic reduction of beta cell apoptosis without changes in proliferation. Whole genome gene profiling analysis of islets isolated from treated Irs2 -/- mice confirmed a broad impact of tungstate on cell death pathways. Mechanistically, tungstate induced Erk1/2 phosphorylation in islets in vitro and, in agreement, treated Irs2 -/- islets exhibited increased basal Erk1/2 phosphorylation. Tungstate also downregulated expression of apoptosis-related genes in Irs2-/- islets in vitro, uncovering a direct effect of this compound in islets. All together, our data demonstrate that tungstate can restore beta cell mass and glucose homeostasis in a context of deficient Insulin/Igf signaling. This study underscores the importance of developing strategies specifically designed to arrest beta cell apoptosis as a means to prevent progressive beta cell failure in diabetes. 10-week old WT and Irs2 -/- mice were randomly divided into two treatment group, in a total of 4 experimental groups. For 21 days one group received distilled water as drinking water (untreated group) whilst the other received ad libitum a solution of 2mg/ml of sodium tungstate in distilled water (treated group). For each experimental group 2 independent samples were analysed, in a total of 8 samples.
2014-01-19 | E-GEOD-43620 | biostudies-arrayexpress
Project description:Relative beta cell deficit and increased beta cell apoptosis are hallmarks of type 2 diabetes (T2D). The Insulin/Insulin Growth Factor (Igf) signaling pathway is an established regulator of beta cell survival and is found downregulated in human T2D islets. The Insulin Receptor Substrate 2 (Irs2) plays a central role in the coordination of this pathway in beta cells. Thus, Irs2 knockout mice (Irs2 -/-) exhibit increased beta cell apoptosis that leads to a progressive decline of beta cell mass and hyperglycaemia. In this study, we sought to determine whether the anti-diabetic compound sodium tungstate could prevent the onset of diabetes in Irs2 -/- mice. Oral administration of tungstate resulted in an overall improvement in whole-body glucose tolerance in Irs2 -/- mice which correlated with increased beta cell mass. Enhanced beta cell mass was due to a dramatic reduction of beta cell apoptosis without changes in proliferation. Whole genome gene profiling analysis of islets isolated from treated Irs2 -/- mice confirmed a broad impact of tungstate on cell death pathways. Mechanistically, tungstate induced Erk1/2 phosphorylation in islets in vitro and, in agreement, treated Irs2 -/- islets exhibited increased basal Erk1/2 phosphorylation. Tungstate also downregulated expression of apoptosis-related genes in Irs2-/- islets in vitro, uncovering a direct effect of this compound in islets. All together, our data demonstrate that tungstate can restore beta cell mass and glucose homeostasis in a context of deficient Insulin/Igf signaling. This study underscores the importance of developing strategies specifically designed to arrest beta cell apoptosis as a means to prevent progressive beta cell failure in diabetes.
2014-01-19 | GSE43620 | GEO
Project description:PGC1a is a transcriptional coactivator that regulates energy metabolism. PGC1a is highly expressed in a subset of melanoma tumors and cell lines. We generated gene-expression profile of control and PGC1alpha depleted A375P melanoma cells, a melanoma cell line that expresses very high levels of PGC1a to investigate the role of this gene in melanoma.
2013-02-25 | GSE36879 | GEO
Project description:Colorectal cancer (CRC) is currently the fourth leading etiology of brain metastasis (BM). Yet, mechanisms supporting the formation of CRC BM are mostly unknown. In order to identify drivers that lead to tropism and adaptation of CRC cells to the brain environment, we analyzed an extensive genomic database, consisting of over 36,000 human CRC primary and metastasis samples. Several genomic alterations specific for BM were noted, among them increased prevalence of insulin receptor substrate 2 (IRS2) amplification, observed in 7.6% of BM, compared to only 2.9% of primary tumors or other metastatic sites (p<7E-05). This observation was validated by Immunohistochemistry studies of human clinical samples, showing increased expression of IRS2 protein in BM. IRS2 is a cytoplasmic adaptor mediating effects of insulin and IGF-1 receptors and is involved in more aggressive behavior of different cancer types. In order to study the ability of IRS2 to promote growth of CRC cells under brain microenvironment conditions, we employed an in vitro system consisting of cultured human astrocytes or their conditioned media. Indeed, IRS2-overexpressed CRC cells survived better and formed larger 3D spheres when grown in brain-mimicking conditions, while IRS2-silenced CRC cells showed a mirror image. Similarly, In vivo studies, using intracranial CRC BM mouse model, demonstrated that IRS2-overexpressed cells generated larger brain lesions, while silencing IRS2 dramatically decreased tumor outgrowth and extended survival. Transcriptomic analysis revealed enrichment of oxidative phosphorylation (OXPHOS) and Wnt/β-catenin pathways by IRS2. Indeed, IRS2-expressing cells showed increased mitochondrial activity and glycolysis-independent viability. Furthermore, IRS2-expressing cells had increased β-catenin transcriptional activity, and either β-catenin inhibition or IRS2 inhibition in IRS2-expressing cells decreased their viability, β-catenin transcriptional activity, and mitochondrial activity. These data suggest involvement of IRS2 in modulating OXPHOS through β-catenin. Exploiting this mechanism as a potential vulnerability allowed us to develop novel treatment strategies against CRC BM. NT219 is a novel IRS1/2 inhibitor already being tested in clinical trials. Treatment of mice harboring CRC BM with NT219 and 5-flourouracil reduced tumor growth and prolonged mice survival. These data reveal, for the first time, the unique genomic profile of CRC BM and imply the IRS2 role in promoting CRC BM. These effects may be mediated, at least in part, by modulation of the β-catenin and OXPHOS pathway. These findings may pave the way for clinical trials evaluation this novel IRS2-based strategy for the treatment of CRC BM.
2022-05-16 | GSE203017 | GEO
Project description:Because injured mitochondria can accelerate cell death through the elaboration of oxidative free radicals and other mediators, it is somewhat paradoxical that proliferator gamma coactivator 1-alpha (PGC1a), a stimulator of increased mitochondrial abundance, protects stressed renal cells instead of potentiating injury. Here we report that PGC1a’s induction of lysosomes via transcription factor EB (TFEB) may be pivotal for kidney protection. CRISPR and stable gene transfer showed that PGC1a knockout tubular cells were sensitized to the genotoxic stressor cisplatin whereas transgenic cells were protected. The biosensor mtKeima unexpectedly revealed that cisplatin blunts mitophagy both in cells and mice. PGC1a not only counteracted this effect but also raised basal mitophagy, as did the downstream mediator nicotinamide adenine dinucleotide (NAD+). PGC1a did not consistent affect known autophagy pathways modulated by cisplatin. Instead RNA sequencing identified coordinated regulation of lysosomal biogenesis via TFEB. This effector pathway was sufficiently important that inhibition of TFEB or lysosomes unveiled a striking harmful effect of excess PGC1a in cells and conditional mice. These results uncover an unexpected effect of cisplatin on mitophagy and PGC1a’s exquisite reliance on lysosomes for kidney protection. Finally, the data illuminate TFEB as a novel target for renal tubular stress resistance.
2019-06-10 | GSE126259 | GEO
Project description:PGC1a and Exercise Adaptations in Zebrafish
| PRJNA474826 | ENA
Project description:Precise modulation of hepatic glucose metabolism is crucial during the fasting and feeding cycle and is controlled by the actions of circulating insulin and glucagon. The insulin-signaling pathway requires insulin receptor substrate 1 (IRS1) and IRS2, which are found to be dysregulated in diabetes and obesity. The peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1A) is a fasting-induced transcriptional coactivator. In nonalcoholic fatty liver disease and in patients with type 2 diabetes, low hepatic PGC1A levels are associated with insulin resistance. However, how PGC1A activity impacts the hepatic insulin-signaling pathway is still unclear. We used gain- and loss-of-function models in mouse primary hepatocytes and measured hepatocyte insulin response by gene and protein expression and ex vivo glucose production. We found that the PGC1A level determines the relative ratio of IRS1 and IRS2 in hepatocytes, impacting insulin receptor signaling via protein kinase B/AKT (AKT). PGC1A drove the expression of IRS2 downstream of glucagon signaling while simultaneously reducing IRS1 expression. We illustrate that glucagon- or PGC1A-induced IRS2 expression was dependent on cAMP Response Element Binding Protein activity and that this was essential for suppression of hepatocyte gluconeogenesis in response to insulin in vitro. We also show that increased hepatic PGC1A improves glucose homeostasis in vivo, revealing a counterregulatory role for PGC1A in repressing uncontrolled glucose production in response to insulin signaling. These data highlight a mechanism by which PGC1A plays dual roles in the control of gluconeogenesis during the fasting-to-fed transition through regulated balance between IRS1 and IRS2 expression.
| S-EPMC6410797 | biostudies-literature
Project description:The effect of liver specific deletion of the insulin receptor substrate-1 (Irs1) and/or Irs2 upon gene expression in the fasted and fed liver of mice; and the effect of liver specific Foxo1 deletion in the Irs1 and Irs2 knockout liver during fasting and feeding.
2008-07-31 | E-MEXP-1649 | biostudies-arrayexpress
Project description:Extrinsic skin ageing converges on the dermis, a post-mitotic tissue compartment consisting of extracellular matrix and long-lived fibroblasts prone to damage accumulation and maladaptation. Aged human fibroblasts exhibit mitochondrial and nuclear dysfunctions, which may be a cause or consequence of ageing. We report on a systematic study of human dermal fibroblasts retrieved from female donors aged 20-67years and analysed ex vivo at low population doubling precluding replicative senescence. According to gene set enrichment analysis of genome wide array data, the most prominent age-associated change of the transcriptome was decreased expression of mitochondrial genes. Consistent with that, mitochondrial content and cell proliferation declined with donor age. This was associated with upregulation of AMP-dependent protein kinase (AMPK), increased mRNA levels of PPARγ-coactivator 1α (PGC1A) and decreased levels of NAD(+)-dependent deacetylase sirtuin 1. In the old cells the PGC1A-mediated mito-biogenetic response to direct AMPK-stimulation by AICAR was undiminished, while the PGC1A-independent mito-biogenetic response to starvation was attenuated and accompanied by increased ROS-production. In summary, these observations suggest an age-associated decline in PGC1A-independent mito-biogenesis, which is insufficiently compensated by upregulation of the AMPK/PGC1A-axis leading under baseline conditions to decreased mitochondrial content and reductive overload of residual respiratory capacity.
2014-04-08 | GSE55118 | GEO