Dataset Information

Podocytes from Hypertensive and Obese Mice Acquire an Inflammatory, Senescent and Aged Phenotype

ABSTRACT: Patients with hypertension or obesity can develop glomerular dysfunction characterized by injury and depletion of podocytes. To better understand the molecular processes involved, young mice were treated with either deoxycorticosterone acetate (DOCA) or fed a high-fat diet (HFD) to induce hypertension or obesity, respectively. The transcriptional changes associated with these phenotypes were measured by unbiased bulk mRNA-sequencing of isolated podocytes from experimental models and their respective controls. Key findings were validated by immunostaining. In addition to a decrease in canonical proteins and reduced podocyte number, podocytes from both hypertensive and obese mice exhibited a sterile inflammatory phenotype characterized by increases in NLRP3 inflammasome, protein cell death-1, and Toll-Like Receptor pathways. Finally, although the mice were young, podocytes in both models exhibited increased expression of senescence and aging genes, including genes consistent with a senescence-associated secretory phenotype. However, there were differences between the hypertension- and obesity-associated senescence phenotypes. Both show stress-induced podocyte senescence characterized by increased p21 and p53. Moreover, in hypertensive mice, this is superimposed upon age-associated podocyte senescence characterized by increased p16 and p19. These results suggest that senescence, aging, and inflammation are critical aspects of the podocyte phenotype in experimental hypertension and obesity in mice.

ORGANISM(S): Mus musculus

PROVIDER: GSE255723 | GEO | 2024/07/03

REPOSITORIES: GEO

ACCESS DATA

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Project description:RATIONALE: Hypertension can lead to podocyte damage and subsequent apoptosis, eventually resulting in glomerulosclerosis. Although alleviating podocyte apoptosis has clinical significance for the treatment of hypertensive nephropathy, an effective therapeutic target has not yet been identified. The function of Septin4, a pro-apoptotic protein and an important marker of organ damage, is regulated by post-translational modification (PTM). However, the exact role of Septin4 in regulating podocyte apoptosis and its connection to hypertensive renal damage remains unclear. OBJECTIVE: We investigated the function and underlying mechanism of Septin4 in AngII-induced hypertensive nephropathy to discover a theoretical basis for targeted treatment. METHODS AND RESULTS: Using transgenic Septin4-K174Q mutant mice treated with the antioxidant Tempol, we found that hyperacetylation of the K174 site of Septin4 exacerbates AngII induced hypertensive renal injury resulting from oxidative stress. Proteomics and western blotting assays indicated that Septin4-K174Q activates the cleaved-PARP1-cleaved-Caspase3 pathway. In Septin4-knockdown human renal podocytes, Septin4-K174R, which mimics deacetylation at K174, rescues podocyte apoptosis induced by AngII. We conclude that Septin4, when activated through acetylation of K174 (K174Q), promotes hypertensive renal injury. Immunoprecipitation and mass spectrometry analyses identified SIRT2 as a deacetylase that interacts with the Septin4 GTPase domain and deacetylates Septin4-K174. In Sirt2-deficient mice and SIRT2-knockdown renal podocytes, Septin4-K174 remains hyperacetylated and exacerbates hypertensive renal injury. By contrast, in Rosa26-Sirt2-Flag (SIRT2-TG) mice and SIRT2-knockdown renal podocytes re-expressing wild-type SIRT2, Septin4-K174 is hypoacetylated and mitigates hypertensive renal injury. CONCLUSION: Septin4-K174R, which mimics deacetylation by SIRT2, inhibits the cleaved-PARP1-cleaved-Caspase3 pathway. Septin4-K174R acts as a renal protective factor, mitigating AngII-induced hypertensive renal injury. These findings indicate that Septin4-K174 is a potential therapeutic target for the treatment of hypertensive renal injury.

Project description:Indoxyl sulfate (IS) is a uremic toxin and ligand of the aryl-hydrocarbon receptor (Ahr), a transcriptional regulator. Elevated serum IS may contribute to the progression of kidney disease. Therefore, we assessed mouse podocyte damage mediated by IS. Ahr was predominantly localized to the podocyte nucleus in vivo and in vitro. In isolated glomeruli, IS-exposure for 2 – 24 h induced Cyp1a1 expression, the most sensitive biomarker of Ahr activation. Mice exposed to IS for 4–8 weeks exhibited microalbuminuria, and mild glomerular injury characterized by ischemic changes, partial podocyte foot process effacement, as well as vascular and tubulointerstitial damage. Chronically IS-exposed kidneys exhibited decreased mRNA, decreased protein levels, and altered staining patterns for podocin, synaptopodin, and non-muscle myosin IIA (Myh9). Immortalized podocytes, upon differentiation, exhibited Ahr nuclear translocation beginning 30 min after 1 mM IS-exposure. At 2 h, there was a dose-dependent decrease in podocyte mRNA expression of WT1, Podxl, Snypo, Myh9, Actn4, and Cd2ap. After 24 h of exposure to IS, podocytes were smaller, had fewer actin/Myh9 fibers, and decreased viability. Ahr-RNAi decreased mRNA expression of podocyte-specific proteins and inhibited Cyp1a1 induction by IS-exposure. Combinations of Ahr-RNAi and IS-exposure further decreased Myh9 expression. In immortalized human podocytes, IS treatment caused cell injury, decreased mRNA expression of podocyte-specific proteins, integrins, collagens, cytoskeletal proteins, and bone morphogenetic proteins, and increased cytokine and chemokine expression. Thus, chronic IS-exposure causes glomerular damage by activating Ahr, altering podocyte function, differentiation, and morphology, and inducing a pro-inflammatory phenotype. Podocyte cells treated with Indoxyl sulfate, a uremic toxin and aryl-hydrocarbon receptor ligand, mediates progressive glomerular disease by damaging podocytes Human podocyte cell line treated with or without 3-Indoxyl sulfate (1mM/0.1%DMSO) in three replications

Dataset Information

Podocytes from Hypertensive and Obese Mice Acquire an Inflammatory, Senescent and Aged Phenotype

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets