Abstract: SA-PO808
Glycolytic Reprogramming and Development of Renal Fibrosis
Session Information
- Molecular Mechanisms of CKD - III
October 27, 2018 | Location: Exhibit Hall, San Diego Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: CKD (Non-Dialysis)
- 1903 CKD (Non-Dialysis): Mechanisms
Authors
- Overstreet, Jessica Marie, Vanderbilt University Medical School, Nashville, Tennessee, United States
- Chung, Sungjin, The Catholic University of Korea College of Medicine, Seoul, Korea (the Republic of)
- Zhang, Ming-Zhi, Vanderbilt University Medical School, Nashville, Tennessee, United States
- Harris, Raymond C., Vanderbilt University Medical Center, Nashville, Tennessee, United States
Background
Tubule dysfunction, myofibroblast differentiation and macrophage polarization are important in the development of renal fibrosis, which accompanies chronic kidney disease (CKD). Glycolytic reprogramming is critical for myofibroblast differentiation and fibrosis in the lung and the polarization of macrophages to an M1 phenotype. Although, dysregulation of cellular metabolism plays a role in the pathogenesis of several diseases, the role of glycolytic reprogramming in kidney fibrosis is unclear.
Methods
Glycolytic flux was measured by determination of extracellular acidification rates (ECAR) using Seahorse respirometry. An acute kidney injury (AKI)-CKD fibrotic model was performed by 31 min unilateral I/R, followed by uninephrectomy at day 8 and initiation of administration of the glycolysis inhibitor, PFK15 every 3 days until day 28. Human renal proximal tubule epithelial cells, mouse renal fibroblasts, and freshly isolated renal macrophages were used for in vitro studies.
Results
Transforming growth factor-β (TGF-β) is a master regulator of glycolytic reprogramming. TGF-β treatment led to increased glycolytic flux in both cultured renal epithelial cells and fibroblasts, as indicated by increased ECAR and ATP production. Glycolysis was reduced to basal levels with glycolytic inhibitors, PFK15 or 3-PO. TGF-β-induced glycolysis in fibroblasts was also confirmed by increased production of lactate. TGF-β-induced proliferation, differentiation (α-SMA), and matrix production (fibronectin) of renal fibroblasts was inhibited by PFK15. I/R injury for 2 days led to increased glycolysis in isolated CD11b+ renal macrophages, which was inhibited by PFK15. In the AKI/CKD fibrotic model, PFK15 markedly decreased renal interstitial fibrosis, indicated by less Sirius red and Masson’s Trichrome staining. PFK15 also inhibited matrix and collagen deposition, α-SMA+ myofibroblasts, epithelial injury (e.g., KIM-1), and immune cell infiltration, including macrophages, CD3+ lymphocytes, and neutrophils.
Conclusion
These results suggest that glycolytic reprogramming is involved in renal tubular epithelial cell dysfunction, myofibroblast differentiation, and macrophage polarization in AKI, and inhibition of glycolytic flux may provide a new therapeutic target to prevent renal fibrosis when recovery from AKI is incomplete.
Funding
- NIDDK Support