Dataset Information

Direct evidence of proximal tubular proliferation in early diabetic nephropathy.

ABSTRACT: Kidney hypertrophy is a common clinical feature in patients with diabetes and is associated with poor renal outcomes. Initial cell proliferation followed by cellular hypertrophy are considered the responsible mechanisms for diabetic kidney hypertrophy. However, whether similar responses against hyperglycemia continue in the chronic phase in diabetes is unclear. We performed lineage tracing analysis of proximal tubular epithelia using novel type 2 diabetic mice with a tamoxifen-inducible proximal tubule-specific fluorescent reporter. Clonal analysis of proximal tubular epithelia demonstrated that the labeled epithelia proliferated in type 2 diabetic mice. Based on the histological analysis and protein/DNA ratio of sorted labeled tubular epithelia, there was no evidence of cellular hypertrophy in type 2 diabetic mice. Lineage tracing and histological analyses of streptozocin-induced type 1 diabetes also revealed that cellular proliferation occurs in the chronic phase of type 1 diabetes induction. According to our study, epithelial proliferation accompanied by SGLT2 upregulation, rather than cellular hypertrophy, predominantly occurs in the hypertrophic kidney in both type 1 and type 2 diabetes. An increased number of SGLT2+ tubular epithelia may be an adaptive response against hyperglycemia, and linked to the hyper-reabsorption of sodium and glucose observed in type 2 diabetes patients.

SUBMITTER: Uehara-Watanabe N

PROVIDER: S-EPMC8763925 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:Background and objectiveSodium glucose cotransporter 2 (SGLT2) is the main luminal glucose transporter in the kidney. SGLT2 inhibition results in glycosuria and improved glycaemic control. Drugs inhibiting this transporter have recently been approved for clinical use and have been suggested to have potential renoprotective benefits by limiting glycotoxicity in the proximal tubule. We aimed to determine the renoprotective benefits of empagliflozin, an SGLT2 inhibitor, independent of its glucose lowering effect.Research design and methodsWe induced diabetes using a low dose streptozotocin protocol in 7-8 week old endothelial nitric oxide (eNOS) synthase knockout mice. We measured fasting blood glucose on a monthly basis, terminal urinary albumin/creatinine ratio. Renal histology was assessed for inflammatory and fibrotic changes. Renal cortical mRNA transcription of inflammatory and profibrotic cytokines, glucose transporters and protein expression of SGLT2 and GLUT1 were determined. Outcomes were compared to diabetic animals receiving the angiotensin receptor blocker telmisartan (current best practice).ResultsDiabetic mice had high matched blood glucose levels. Empagliflozin did not attenuate diabetes-induced albuminuria, unlike telmisartan. Empagliflozin did not improve glomerulosclerosis, tubular atrophy, tubulointerstitial inflammation or fibrosis, while telmisartan attenuated these. Empagliflozin did not modify tubular toll-like receptor-2 expression in diabetic mice. Empagliflozin did not reduce the upregulation of macrophage chemoattractant protein-1 (MCP-1), transforming growth factor β1 and fibronectin mRNA observed in the diabetic animals, while telmisartan decreased transcription of MCP-1 and fibronectin. Empagliflozin increased GLUT1 mRNA expression and telmisartan increased SGLT2 mRNA expression in comparison to untreated diabetic mice. However no significant difference was found in protein expression of GLUT1 or SGLT2 among the different groups.ConclusionHence SGLT2 inhibition does not have renoprotective benefits independent of glucose lowering.

Project description:BackgroundDiabetic kidney disease (DKD) has mainly been considered as a glomerular disease. Our previous study showed that the progression of DKD was highly correlated with the dysfunction of renal proximal tubular cells. Fermented Cordyceps sinensis (CS), a substitute for natural CS, is a prominent herb widely used in China, and has exhibited excellent efficacy on DKD. However, the underlying mechanisms remain poorly understood.MethodsThe database analysis was used to identify the main therapeutic targets and pathways of CS involved in DKD treatment. Next, the protective effects of fermented CS on high glucose (HG, 30 mM) induced HK-2 cell injury was validated through cell proliferation and apoptosis assay, including CCK-8, EdU and TUNEL. Finally, quantitative real‑time PCR (qRT-PCR) and western blotting were used to verify key target genes.ResultsOur results revealed that 9 main targets (RELA, JNK1, PTEN, VEGFA, EGF, ERK2, CASP3, AKT1, MMP9) were recognized as key therapeutic targets with excellent binding affinity screened by database analysis and molecular docking. The biological processes were identified by Gene Ontology (GO) enrichment, which appeared mainly involved in the positive regulation of cell proliferation as well as the negative regulation of apoptosis. The verification experiments in vitro revealed that fermented CS significantly attenuated the HG-induced cytotoxicity and apoptosis, and promoted the proliferation of HK-2 cells. Moreover, fermented CS significantly downregulated the expressions of Bax, Caspase-3, VEGFA, P-AKT and P-ERK, and upregulated the expression of PTEN compared with that of HG group.ConclusionOur results demonstrate that the fermented CS has nephroprotective effects significantly, which functions via promoting proliferation and inhibiting apoptosis of renal proximal tubular cells, likely by targeting Caspase-3, Bax, VEGFA and PTEN. Furthermore, AKT and ERK signaling pathway may be the critical mechanisms underlying the efficacy of fermented CS in DKD treatment.

Dataset Information

Direct evidence of proximal tubular proliferation in early diabetic nephropathy.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets