Obesity induces macrophages to drive inflammation in adipose tissue, a crucial step towards the development of type 2 diabetes. The tricarboxylic acid (TCA) cycle intermediate succinate is released from cells under metabolic stress and has recently emerged as a metabolic signal induced by proinflammatory stimuli. We therefore investigated whether succinate receptor 1 (SUCNR1) could play a role in the development of adipose tissue inflammation and type 2 diabetes. Succinate levels were determined in human plasma samples from individuals with type 2 diabetes and non-diabetic participants. Succinate release from adipose tissue explants was studied. Sucnr1 -/- and wild-type (WT) littermate mice were fed a high-fat diet (HFD) or low-fat diet (LFD) for 16 weeks. Serum metabolic variables, adipose tissue inflammation, macrophage migration and glucose tolerance were determined. We show that hypoxia and hyperglycaemia independently drive the release of succinate from mouse adipose tissue (17-fold and up to 18-fold, respectively) and that plasma levels of succinate were higher in participants with type 2 diabetes compared with non-diabetic individuals (+53%; p < 0.01). Sucnr1 -/- mice had significantly reduced numbers of macrophages (0.56 0.07 vs 0.92 0.15 F4/80 cells/adipocytes, p < 0.05) and crown-like structures (0.06 0.02 vs 0.14 0.02, CLS/adipocytes p < 0.01) in adipose tissue and significantly improved glucose tolerance (p < 0.001) compared with WT mice fed an HFD, despite similarly increased body weights. Consistently, macrophages from Sucnr1 -/- mice showed reduced chemotaxis towards medium collected from apoptotic and hypoxic adipocytes (-59%; p < 0.05). Our results reveal that activation of SUCNR1 in macrophages is important for both infiltration and inflammation of adipose tissue in obesity, and suggest that SUCNR1 is a promising therapeutic target in obesity-induced type 2 diabetes.
SUCNR1-mediated chemotaxis of macrophages aggravates obesity-induced inflammation and diabetes.
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View SamplesUBL5 is an atypical ubiquitin-like protein, whose function in metazoans remains largely unexplored. We show that UBL5 is required for sister chromatid cohesion maintenance in human cells. UBL5 primarily associates with spliceosomal proteins, and UBL5 depletion decreases pre-mRNA splicing efficiency, leading to globally enhanced intron retention. Defective sister chromatid cohesion is a general consequence of dysfunctional pre-mRNA splicing, resulting from the selective downregulation of the cohesion protection factor Sororin. As the UBL5 yeast orthologue, Hub1, also promotes spliceosome functions, our results show that UBL5 plays an evolutionary conserved role in pre-mRNA splicing, the integrity of which is essential for the fidelity of chromosome segregation. Overall design: Total RNA was extracted from HeLa cells treated with control (CTRL), UBL5 (#57, #58, or #82), or SART1 siRNAs for 48 h and processed for RNA-Seq analysis
UBL5 is essential for pre-mRNA splicing and sister chromatid cohesion in human cells.
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View SamplesIn order to investigate how electrophysiological properties vary within the Pthlh population in the dorsolateral striatum we performed PatchSeq analysis of neurons labeled in 5HT3a(EGFP) and Pvalb(cre)::RCE/tdTomato mouse lines, which included Th, Npy/Mia, Cck, and Cck/Vip expressing cells. Overall design: 98 FACS-sorted single cells isolated from the dorso-lateral striatum from either a 5ht3a-EGFP mouse line or a Lhx6-cre mouse crossed onto a R26R-tdTomato reporter mouse line
Diversity of Interneurons in the Dorsal Striatum Revealed by Single-Cell RNA Sequencing and PatchSeq.
Specimen part, Cell line, Subject
View SamplesAnalysis of genes and pathways related to psychomotor retardation symptoms in patients with major depressive disorder. Results indicate that psychomotor slowing is associated with enrichment of inflammatory and metabolic pathways in unmedicated patients with depression.
Protein and gene markers of metabolic dysfunction and inflammation together associate with functional connectivity in reward and motor circuits in depression.
Sex, Age, Specimen part, Race, Subject
View SamplesSir2 is an NAD+-dependent histone deacetylase, and is the founding member of a large, phylogentically conserved, family of such deacetylases called the Sirtuins. The budding yeast, Saccharomyces cerevisiae, harbors 4 paralogs of Sir2, known as Hst1, Hst2, Hst3, and Hst4. Reducing the intracellular NAD+ concentration is inhibitory for the Sirtuins, and raising the intracellular nicotinamide (NAM) concentration is inhibitory. Microarray gene expression analysis was used to identify novel classes of yeast genes whose expression is altered when either NAD+ concentration is reduced or NAM is elevated. A subset of genes involved in thiamine biosynthesis was identified as being upregulated when Sir2 or Hst1 was inactivated.
Thiamine biosynthesis in Saccharomyces cerevisiae is regulated by the NAD+-dependent histone deacetylase Hst1.
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View SamplesThe chronological lifespan (CLS) of Saccharomyces cerevisiae is defined as the number days that non-dividing cells remain viable, typically in stationary phase cultures or in water. CLS is extended by restricting glucose in the starting cultures, and is considered a form of caloric restriction (CR). Through a previous genetic screen our lab determined that deleting components of the de novo purine biosynthesis pathway also significantly increased CLS. Significant similarities in gene expression profiles between calorie restricted WT cells and a non-restricted ade4 mutant suggested the possibility of common gene expression biomarkers of all chronologically long lived cells that could also provide insights into general mechanisms of lifespan extension. We have identified additional growth conditions that extend CLS of WT cells, including supplementation of the media with isonicotinamide (INAM), a known sirtuin activator, or by supplementation with a concentrate collected from the expired media of a calorie restricted yeast culture, presumably due to an as yet unidentified longevity factor. Using these varied methods to extend CLS, we compared gene expression profiles in the aging cells (at day 8) to identify functionally relevant biomarkers of longevity. Nineteen genes were differentially regulated in all 4 of the long-lived populations relative to wild type. Of these 19 genes, viable haploid deletion mutants were available for 16 of them, and 12 were found to have a significant impact on CLS.
Functional genomic analysis reveals overlapping and distinct features of chronologically long-lived yeast populations.
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View SamplesThe cleavage of sphingoid base phosphates by sphingosine-1-phosphate (S1P) lyase to produce phosphoethanolamine and a fatty aldehyde is the final degradative step in the sphingolipid metabolic pathway. We have studied mice with an inactive S1P lyase gene and have found that, in addition to the expected increase of sphingoid base phosphates, other sphingolipids (including sphingosine, ceramide, and sphingomyelin) were substantially elevated in the serum and /or liver of these mice. This latter increase is consistent with a reutilization of the sphingosine backbone for sphingolipid synthesis due to its inability to exit the sphingolipid metabolic pathway. Furthermore, the S1P lyase deficiency resulted in changes in the levels of serum and liver lipids not directly within the sphingolipid pathway, including phospholipids, triacyglycerol, diacylglycerol, and cholesterol. Even though lipids in serum and lipid storage were elevated in liver, adiposity was reduced in the S1P lyase-deficient mice. Microarray analysis of lipid metabolism genes in liver showed that the S1P lyase deficiency caused widespread changes in their expression pattern. These results demonstrate that S1P lyase is a key regulator of the levels of multiple sphingolipid substrates and reveal functional links between the sphingolipid metabolic pathway and other lipid metabolic pathways that may be mediated by shared lipid substrates and changes in gene expression programs. The disturbance of lipid homeostasis by altered sphingolipid levels may be relevant to metabolic diseases.
Sphingosine 1-phosphate lyase deficiency disrupts lipid homeostasis in liver.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Age-associated changes in basal NF-κB function in human CD4+ T lymphocytes via dysregulation of PI3 kinase.
Sex, Age, Specimen part, Treatment
View SamplesImmune impairment and high circulating level of pro-inflammatory cytokines are landmarks of human aging. However, the molecular basis of immune dysregulation and the source of inflammatory markers remain unclear. Here we demonstrate that in the absence of overt cell stimulation, gene expression mediated by the transcription factor NF-B is higher in purified and rested human CD4+ T lymphocytes from older compared to younger individuals. This increase of NF-B -associated transcription includes transcripts for pro-inflammatory cytokines such as IL-1 and chemokines such as CCL2 and CXCL10. We demonstrate that NF-B up-regulation is cell-intrinsic and mediated in part by phosphatidylinositol 3-kinase (PI3K) activity induced in response to metabolic activity, which can be moderated by rapamycin treatment. Our observations provide direct evidence that dysregulated basal NF-B activity may contribute to the mild pro-inflammatory state of aging.
Age-associated changes in basal NF-κB function in human CD4+ T lymphocytes via dysregulation of PI3 kinase.
Sex, Age, Specimen part, Treatment
View SamplesImmune impairment and high circulating level of pro-inflammatory cytokines are landmarks of human aging. However, the molecular basis of immune dysregulation and the source of inflammatory markers remain unclear. Here we demonstrate that in the absence of overt cell stimulation, gene expression mediated by the transcription factor NF-B is higher in purified and rested human CD4+ T lymphocytes from older compared to younger individuals. This increase of NF-B -associated transcription includes transcripts for pro-inflammatory cytokines such as IL-1 and chemokines such as CCL2 and CXCL10. We demonstrate that NF-B up-regulation is cell-intrinsic and mediated in part by phosphatidylinositol 3-kinase (PI3K) activity induced in response to metabolic activity, which can be moderated by rapamycin treatment. Our observations provide direct evidence that dysregulated basal NF-B activity may contribute to the mild pro-inflammatory state of aging.
Age-associated changes in basal NF-κB function in human CD4+ T lymphocytes via dysregulation of PI3 kinase.
Sex, Age, Specimen part, Treatment
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