Hypoxia-inducible Factor may Induce the Development of Liver Fibrosis in Budd-Chiari Syndrome by Regulating CD248/endosialin Expression: A Hypothesis.

Budd-Chiari syndrome (BCS) leads to the development of liver fibrosis in most of the cases. However, the mechanism of BCS-related liver fibrosis is unclear, and it may be largely different from that induced by chronic viral hepatitis. Hepatic stellate cell (HSC) and its specific marker CD248/endosialin are known to play an important regulatory role in the development of liver fibrosis. Additionally, hypoxia microenvironment and hypoxia-inducible factor (HIF) are involved in the regulation of CD248/endosialin. Therefore, we hypothesize that hypoxia microenvironment which develops due to BCS can regulate the expression of CD248/endosialin in HSC via HIF signaling pathway, which then affects the function of HSC and development of liver fibrosis. To confirm the hypothesis, two major investigations are necessary: (1) in the BCS animal model and clinical studies, the relationship between the severity of liver fibrosis and the expression of HIF and CD248/endosialin in HSC will be explored; and (2) in the in vitro cell system, the effect of hypoxic microenvironment, HIF-1α or HIF-2α, on the expression of CD248/endosialin in HSC will be explored. It will be important to elucidate whether HIF signaling pathway regulates the expression of CD248/endosialin, thereby inducing the development of BCS-related liver fibrosis.