Hyperglycemia in Combination With Excess Fat Intake Promotes Renal Pyroptosis and Fibrosis Through Gα12-Dependent Endoplasmic Reticulum Stress

Authors

• Muhammad Sohaib Khan
• Boram Kim
• Yerim Jeon
• Jihoon Tak
• Yun Seok Kim
• Sang Gil Lee
• Eun Byul Lee
• Chang-Hoon Lee
• Cheol Bin Eom
• Hyun Sook Lee
• Hyeon-Ki Jang
• Nakyeom Lee
• Jeong Hae Kie
• Jee Myung Yang
• Yoon Mee Yang
• Sang Geon Kim

Language

English

Publication Date

1-1-2026

Journal

Theranostics

DOI

10.7150/thno.124015

PMID

41695476

PMCID

PMC12905788

PubMedCentral® Posted Date

1-14-2026

PubMedCentral® Full Text Version

Post-print

Abstract

Background: Chronic exposure to free fatty acids (FFAs) and glucose may disrupt metabolic homeostasis and initiate pathological processes. This study investigated the effects of hyperglycemia and fat overload on renal endoplasmic reticulum (ER) stress, pyroptosis and fibrogenesis in mice and the underlying basis. We hypothesized that the combined insult would more severely induce Gα12-dependent ER stress and renal complications.

Methods: Mice were subjected to either high fat diet (HFD)+streptozotocin (STZ), or STZ treatment, and AZ2 was used as an anti-diabetic agent. Blood sera were used for blood biochemistry, and tissues were employed for RNA sequencing, immunoblottings, TEM, histology and immunohistochemistry. HEK293 and other cells were used for high glucose (HG) and palmitate treatment, or Gα12 or siGα12 transfection.

Results: The combined HFD and STZ treatment, showing enrichment of genes related to GPCR signaling, inflammasome, ER stress, and pyroptosis in the RNA-sequencing analysis, upregulated Gα12 in the kidney, alongside increased PGC1α and PPARα. IRE1α and ATF6 were elevated without an increase in GRP78. This was accompanied by elevated blood glucose, creatinine, and BUN levels. We also found increases of pro-IL-1β, IL-1β, caspase-1, and NLRP3, demonstrating pyroptosis. Immunoassays revealed increased fibrosis markers. AZ2 reversed these changes. STZ treatment alone exhibited mild complications in the absence of Gα12 induction despite severe hyperglycemia. In cell-based assays, HG+palmitate elicited IRE1 activation along with Gα12 overexpression although HG alone had a minimal effect. Overexpression of Gα12 facilitated the effect of HG+palmitate on ER stress, pyroptosis, and fibrosis, whereas Gα12 knockdown had the opposite effect, as corroborated by the outcomes obtained using STZ-treated Gα12-/-, Gα12+/-, and Gα13 liver-specific KO mice.

Conclusion: These findings support the role of HG and lipid overload combination in driving renal pyroptosis and fibrogenesis through Gα12-mediated ER stress and inflammasome, delineating the mechanism underlying the conditions of diabetic renal complications and pharmacological intervention.

Keywords

Endoplasmic Reticulum Stress, Animals, Mice, Fibrosis, Diet, High-Fat, Pyroptosis, Hyperglycemia, Humans, Kidney, Male, Endoplasmic Reticulum Chaperone BiP, Mice, Inbred C57BL, HEK293 Cells, Diabetes Mellitus, Experimental, Inflammasomes, Fatty Acids, Nonesterified, renal pyroptosis, fibrosis, free fatty acids, hyperglycemia, ER stress, human kidney

Published Open-Access

yes

Recommended Citation

Khan, Muhammad Sohaib; Kim, Boram; Jeon, Yerim; et al., "Hyperglycemia in Combination With Excess Fat Intake Promotes Renal Pyroptosis and Fibrosis Through Gα12-Dependent Endoplasmic Reticulum Stress" (2026). Faculty, Staff and Student Publications. 3416.
https://digitalcommons.library.tmc.edu/uthmed_docs/3416