High salt (HS) diet can accelerate the progress of hypertensive left ventricular (LV) remodeling. But the detailed mechanism remains poorly understood. We hypothesized HS intake could impact cardiac lymphangiogenesis through tonicity-responsive enhancer binding protein (TonEBP)/vascular endothelial growth factor-C (VEGF-C) signaling pathway which might play an important role in HS intake accelerated LV remodeling. Eight-week-old male spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY) were randomized to 0.5% NaCl (Low salt, LS) and 8% NaCl (high salt, HS) diets for 12 weeks. LV remodeling was determined by echocardiography. LV invasive hemodynamic analysis and morphologic staining (cardiomyocyte hypertrophy, collagen deposition, TonEBP expression, macrophage infiltration and lymphatic density) were performed at the time of sacrifice. The blood pressure of SHR-HS group was significantly increased compared to SHR-LS and WKY groups. Meanwhile, The LV chamber size was markedly enlargement, LV function apparently compromised accompanied with a severe macrophage infiltration, and fibrosis in the perivascular and interstitium of LV compared with SHR-LS group. Furthermore, the expression levels of VEGF-C, TonEBP, and lymphatic markers in SHR-HS group were significantly increased parallel with apparent lymphangiogenesis compared with SHR-LS group. Our work indicates that TonEBP/VEGF-C signaling pathway was up-regulated in HS intake accelerated hypertensive LV remodeling process that may be valuable for further investigation.
Keywords: Hypertension; TonEBP; VEGF-C; left ventricular remodeling; lymphangiogenesis; macrophage.