Down-regulated cylindromatosis enhances NF-κB activation and aggravates inflammation in HBV-ACLF patients.

The pathogenesis of liver in patients with hepatitis B virus-associated acute chronic liver failure (HBV-ACLF) remains largely unknown. We aimed to elucidate the molecular mechanism underlying the pathogenesis of liver in HBV-ACLF patients by using multiple approaches including transcriptome analysis. We performed transcriptomic sequencing analysis on the liver of HBV-ACLF patients (n = 6), chronic hepatitis B (n = 6), liver cirrhosis (n = 6) and normal control (n = 5), then explored the potential pathogenesis mechanism in liver specimen from another 48 subjects and further validated the molecular and cellular mechanisms using THP-1 cells. RNA-sequencing data analysis indicated that, among the genes up-regulated in HBV-ACLF, genes related to inflammatory response and chemotaxis accounted for a large proportion of the total DEGs. A number of key chemokines (CCL2, CCL5, CCL20, CXCL5, CXCL6, CXCL8) and NF-ĸB pathway were identified to be robust in the liver samples from HBV-ACLF patients. Interestingly, cylindromatosis (CYLD) was found to be downregulated in the liver of HBV-ACLF patients, in line with the well-established role of CYLD in regulating most of the chemokines and pro-inflammatory cytokines (CCL2, CCL5, CCL20, CXCL5, CXCL6, CXCL8, IL-6, IL-1β) via inhibition of NF-ĸB. Indeed, the knockdown of CYLD resulted in sustained activation of NF-ĸB in macrophages and enhanced chemokines and inflammatory cytokines production, which in turn enhanced chemotactic migration of neutrophil, monocyte, T lymphocytes, and NK cell. In conclusions, down-regulated CYLD aggravated inflammatory cell chemotaxis through enhancing NF-κB activation in HBV-ACLF patients, thereby participating in the pathogenesis of HBV-ACLF injury.