Abstract: SA-PO123
COUP-TFII Enhances TGFβ-Induced Metabolic Reprogramming in Stromal Cells and Contributes to Kidney Fibrosis
Session Information
- AKI: Mechanisms - AKI-CKD Transition
November 09, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Acute Kidney Injury
- 103 AKI: Mechanisms
Authors
- Li, Li, Brigham and Women's Hospital, Boston, Massachusetts, United States
- Figueroa Ramirez, Ana Cristina, Brigham and Women's Hospital, Boston, Massachusetts, United States
- Tamayo, Diana, Brigham and Women's Hospital, Boston, Massachusetts, United States
- Mccracken, Kyle, Boston Children's Hospital, Boston, Massachusetts, United States
- Bonventre, Joseph V., Brigham and Women's Hospital, Boston, Massachusetts, United States
Background
Metabolic perturbation is implicated in the pathogenesis of kidney fibrosis, but the molecular mechanisms that couple myofibroblast metabolism and differentiation are unknown. COUP-TFII is an orphan nuclear receptor involved in metabolic regulation, but its role in the kidney has not been investigated. We hypothesized that TGFβ-induced metabolic reprogramming in stromal cells is regulated by COUP-TFII.
Methods
Unilateral ureter obstruction (UUO) surgery was used for in vivo modeling of kidney injury and fibrosis. In vitro, we used CRISPR and an inducible lentiviral construct to generate COUP-TFII loss- and gain-of-function models in C3H/10T1/2 cells. For metabolic assays, we used the Seahorse XF24 flux analyzer and JC-1 staining to estimate glycolysis and the mitochondrial membrane potential. We generated conditional COUP-TFII deficient (cKO) mice by crossing floxed alleles with an inducible Cre driver.
Results
We first examined gene expression in fibrotic kidneys and found that key glycolytic enzymes were upregulated while PGC1α was suppressed seven days after UUO. This expression pattern was conserved in TGFβ-treated C3H/10T1/2 cells. Accordingly, TGFβ treatment in vitro led to increased cellular lactate production and decreased mitochondrial membrane potential. Interestingly, we found that COUP-TFII was required for the TGFβ-induced shift toward glycolysis, and COUP-TFII KO cells exhibited an attenuated profibrotic phenotype. In contrast, overexpression of COUP-TFII was sufficient to enhance glycolysis and increase αSMA and collagen 1 levels. This pathway was further interrogated in vivo, where cKO mice were protected from kidney fibrosis.
Conclusion
TGFβ induces a shift in cellular metabolism from oxidative respiration to aerobic glycolysis, and this effect is dependent on COUP-TFII activation. Loss of COUP-TFII ameliorates fibrotic phenotypes both in vitro and in vivo. These findings provide new mechanistic insights into TGFβ-induced myofibroblast differentiation pathways, and targeting COUP-TFII may thus serve as a novel treatment approach for mitigating kidney fibrosis in chronic kidney disease.
Funding
- NIDDK Support