Hydrostatic pressure driven vascular degeneration in cirrhosis [pLSEC]
The role of pathological vascular degeneration in cirrhosis remains poorly understood. In this study, we engineered multidimensional vascular models to replicate the pathological characteristics of liver sinusoidal endothelial cells (LSECs) at various fibrosis stages. Our investigation revealed that LSEC response to hydrostatic pressure is matrix stiffness-dependent, with LSECs survival when cultured on soft matrices, while those cultured on hard matrices experiencing cellular damage. The biomimic vascular in vitro model enabled us to identify GPR116 as a crucial membrane receptor of LSECs to sense and respond to hydrostatic pressure. GPR116 is specifically expressed in liver endothelial cells, and silencing GPR116 effectively protected the endothelial cells from hydrostatic pressure-induced damage on hard matrix, consequently inhibiting hepatic stellate cell activation and collagen remodeling. Thus, our findings highlight GPR116 as an indispensable pressure sensor in hepatic sinusoidal endothelium, playing a pivotal role in vascular remodeling during cirrhosis. Overall design: To validate the biomimicry of the in vitro model, we compared the transcriptome similarity between mouse LSECs cultured in vitro and LSECs in different stages of hepatic fibrosis. We isolated primary LSECs(pLSECs) from healthy mice were cultured on substrates with varying stiffness (1.5 kPa, and 11 kPa) and subjected to different hydrostatic pressure (10mmHg and 20mmHg).  The pLSECs cultured on 1.5 kPa substrates under 10mmHg is Soft+LP group.The pLSECs cultured on 11 kPa substrates under 20mmHg is Stiff+HP group.  pLSECs were isolated from mice with early hepatic fibrosis (4W) and cirrhosis (12W) induced with CCl4 for 4 and 12 weeks respectively. pLSECs from normal mouse(NC), Soft+HP group and Stiff+HP group were analyzed by RNA-seq. Differentially expressed genes (DEGs) analysis revealed drastic changes of LESCs during fibrosis progression in vivo (NC versus 4W versus 12W) and during in vitro culture (NC versus Soft+LP versus Stiff+HP) .