Abstract: SA-PO760
The Mechanism of Glutamine Catabolism in the Activation of Renal Fibroblasts
Session Information
- CKD: Mechanisms - III
November 09, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: CKD (Non-Dialysis)
- 2103 CKD (Non-Dialysis): Mechanisms
Authors
- Cai, Yang, Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology, Wuhan, China
- Han, Min, Tongji Hospital, Tongji Medical College, Wuhan, Hubei, China
- Xu, Gang, Tongji hospital affiliated to Tongji medical college, Huazhong University of Science and Technology, Wuhan, China
Background
Glutamine catabolism enhances the activity of tricarboxylic acid cycle and synthesizes key intermediate metabolites required for amino acids. This study will explore the role of glutamine catabolism in the activation of fibroblasts.
Methods
Activation of fibroblasts was induced by TGF-β1, changes of metabolites during fibroblast activation were detected by non-targeted metabolomics. The expression of GLS1, the key enzyme of glutamine catabolism, was detected by western blot. After the inhibition of GLS1 by specific inhibitors or siRNA, the proliferation, activation and migration of fibroblasts were detected. Glutamine was deprived during fibroblast activation, and the effects of glutamine on mitochondrial function were detected by measuring mitochondrial content, morphology, membrane potential, and oxygen consumption rate. The effects of supplementation with α-ketoglutarate after deprivation of glutamine on proliferation, activation, migration and mitochondrial function of fibroblasts were observed. In vivo experiment, intraperitoneal injection of BPTES after the UUO model was constructed, and the effect of BPTES on renal fibrosis was determined by pathological staining and immunohistochemistry.
Results
After TGF-β1 treatment, non-targeted metabolomics suggested that glutamate content increased significantly and pathway analysis highlighted significant enhancement of glutamine metabolism. The expression of GLS1 was significantly increased during fibroblast activation. After inhibition of GLS1, the proliferation, activation and migration of fibroblasts were significantly inhibited. After deprivation of glutamine during fibroblast activation, the mitochondrial content was significantly reduced, mitochondria were fragmented, the mitochondrial membrane potential, mitochondrial oxygen consumption rate, and ATP generation were all significantly reduced. After deprivation of glutamine and supplementation with α-ketoglutarate, the proliferation, activation and migration of fibroblasts were increased, and the mitochondrial content and mitochondrial membrane potential was partially recovered. In UUO model, BPTES could inhibit the activation of renal fibroblasts and alleviate renal fibrosis.
Conclusion
Glutamine catabolism plays an important role during fibroblast activation. Inhibition of glutamine catabolism can inhibit the proliferation and activation of renal fibroblasts and improve renal fibrosis.