Abstract P016: GYY4137, a Hydrogen Sulfide Donor, Mitigates Ang II-induced Extracellular Matrix Remodeling in Glomerular Endothelial and Mesangial Cells
Hypertensive nephropathy is associated with progressive alteration of extracellular matrix (ECM) components. Both mesangial and glomerular endothelial cells have the ability to synthesize and degrade ECM proteins such as collagens by changes in the activity of matrix metalloproteinases (MMPs) and their inhibitors, tissue inhibitors of metalloproteinases (TIMPs). Endo180 is an extracellular fibronectin type II domain involved in lysosomal degradation of collagen which has been shown to mitigate renal fibrosis. More recently, hydrogen sulfide (H2S) has also been shown to mitigate hypertensive renal remodeling, however, its mechanism remains unclear. In this study, our aim was to investigate whether Angiotensin-II (Ang II) treatment alters the expression of Endo180, MMPs and TIMPs leading to dysregulation of collagen metabolism and whether GYY4137 (H2S donor) restores their levels to achieve homeostasis. Mesangial and mouse glomerular endothelial cells (MCs and MGECs respectively) were treated without or with Ang II (200 nM) and GYY4137 (250 μM) for 48hrs. Cell lysates were analyzed for MMP-13, -14, TIMP-1, Endo180, and collagen IV by Western blot, RT-PCR, and immunohistochemistry. In MGECs, Ang II treatment compared to its control decreased MMP-13/TIMP-1 ratio (0.75±0.44 vs. 2.48 ±0.73), and upregulated MMP-14/TIMP-1 ratio (0.64±2.10 vs. 0.96±1.47), and collagen IV (0.77±0.07 vs. 0.58±0.06). GYY4137 treatment mitigated these changes. In contrast, Ang II treatment in MCs decreased Endo180 compared to control (0.72±0.04 vs. 1.07±0.23), but did not alter the expression of MMP-13/TIMP-1, MMP-14/TIMP-1 ratios, and collagen IV level compared to control or MGECs. Similarly, immunostaining showed downregulation of MMP-13 and Endo180 in Ang II treated MGECs which was normalized following GYY4137 treatment. Endo180 was also normalized in MCs following GYY4137 treatment however, there was no change in MMP-14/TIMP-1 ratio or collagen IV level. We conclude that Ang II treatment causes adverse ECM remodeling in MGECs via downregulation of Endo180 and MMP-13 and upregulation of MMP-14 and TIMP-1 and in MCs by decreasing Endo180, and GYY4137 mitigates these changes in part, by modulating Endo180/MMP/TIMP pathway.
Author Disclosures: M. Amin: None. S. Pushpakumar: None. S. Kundu: None. G. Tyagi: None. A. Tyagi: None. U. Sen: None.
- © 2015 by American Heart Association, Inc.