Soluble ST2 is an early marker and treatment target for hypertensive nephrosclerosis signatured in glomerular mesangial cells

Abstract

The absence of a biologic marker for hypertensive nephrosclerosis (HN) remains a challenge. This study aimed at exploring the relationship between sST2 and early HN and examining their interaction in glomerular mesangial cells. The serum sST2 levels of healthy controls (HC; n=9), patients with HN (n=15), and patients with lupus nephritis (LN; n=27) were measured using ELISA. The association between the serum sST2 levels and clinicopathologic characteristics, including kidney function and mesangial proliferation, were assessed. The expression of ST2 and fibrotic markers in glomerular mesangial cells in hypertensive conditions was evaluated using a 5/6 nephrectomy rat model. To mimic intraglomerular hypertension, human primary glomerular mesangial cells (hPGMCs) were subjected to a 3-mmHg pressure using a newly developed mechanical pressurizing device. The cells were then treated with anti-ST2 antibody (0.5 and 1 μg/mL) to examine inflammation, apoptosis, and necrosis. The serum sST2 levels were significantly higher in the HN and LN groups than in the HC group. Increased expression of ST2 and fibrotic markers in glomerular mesangial cells was observed in the hypertension-induced animal model. In the in vitro study, pressure-stimulated hPGMCs exhibited increased population of early and late apoptosis, which were markedly reduced after treatment with anti-ST2 antibody (1.0 μg/mL). ST2 indicates the early pathologic changes of hypertensive kidney damage and may serve as a mesangial cell-specific marker for HN in terms of determining kidney function and pathologic findings. Thus, ST2 blockade could be a novel therapeutic approach for HN.