# HCV NS5A Up-Regulates COX-2 Expression via IL-8-Mediated Activation of the ERK/JNK MAPK Pathway

## TL;DR

This study shows how HCV infection increases COX-2 expression through IL-8 and the ERK/JNK pathways, contributing to liver inflammation and disease progression.

## Contribution

The study identifies a novel mechanism by which HCV NS5A activates COX-2 via IL-8 and MAPK pathways.

## Key findings

- HCV infection and NS5A expression significantly induce COX-2 and IL-8.
- ERK and JNK pathways mediate IL-8-driven COX-2 induction in HCV infection.
- The C/EBP regulatory element in the COX-2 promoter is critical for its induction by HCV.

## Abstract

Chronic hepatitis C virus (HCV) infection leads to intrahepatic inflammation and liver cell injury, which are considered a risk factor for virus-associated hepatitis, cirrhosis, and hepatocellular carcinoma worldwide. Inflammatory cytokines are critical components of the immune system and influence cellular signaling, and genetic imbalances. In this study, we found that cyclooxygenase-2 (COX-2) and interleukin-8 (IL-8) were significantly induced by HCV infection and HCV NS5A expression, and induction of COX-2 correlated with HCV-induced IL-8 production. We also found that the ERK and JNK signaling pathways were involved in the regulation of IL-8-mediated COX-2 induction in response to HCV infection. Using a promoter-linked reporter assay, we identified that the C/EBP regulatory element within the COX-2 promoter was the dominant factor responsible for the induction of COX-2 by HCV. Silencing C/EBP attenuated HCV-induced COX-2 expression. Our results revealed that HCV-induced inflammation promotes viral replication, providing new insights into the involvement of IL-8-mediated COX-2 induction in HCV replication.