Open AccessThe Paradoxical Effects of Different Hepatitis C Viral Loads on Host DNA Damage and Repair Abilities
Author(s) -
Shu-Chi Wang,
Kuan-Ru Lai,
Chia-Yang Li,
ChiShiun Chiang,
Guann-Yi Yu,
Naoya Sakamoto,
WenYu Tu,
Meng-Hsuan Hsieh,
JeeFu Huang,
WanLong Chuang,
ChiaYen Dai,
MingLung Yu
Publication year - 2017
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0164281
Subject(s) - dna damage , biology , dna repair , viral load , viral replication , population , intracellular , virus , microbiology and biotechnology , dna , virology , genetics , medicine , environmental health
Hepatitis C virus (HCV)-induced hepatic stress is associated with increased oxidative DNA damage and has been implicated in hepatic inflammation. However, HCV infection and replication are uneven and vary among individual hepatocytes. To investigate the effect of the viral load on host DNA damage, we used an Enhanced Yellow Fluorescent Protein gene (EYFP)-tagged HCV virus to distinguish between HCV intracellular high viral load (HVL) cells and low viral load (LVL) cells. The cell sorting efficiency was confirmed by the high expression of the HCV polyprotein. We found DNA damage γ-H2AX foci in the HVL population. Comet assays demonstrated that HVL was related to the extent of the DNA strand breaks. Surprisingly, the DNA qPCR arrays and western blotting showed that the damage-related genes GPX2, MRE11, phospho-ATM, and OGG1 were significantly up-regulated in LVL cells but inversely down-regulated or consistently expressed in HVL cells. The colony survival assay to examine the repair abilities of these cells in response to irradiation showed that the LVL cells were more resistant to irradiation and had an increased ability to repair radiation-induced damage. This study found that intracellular viral loads drove cellular DNA damage levels but suppressed damage-related gene expression. However, the increase in damage-related gene expression in the LVL cells may be affected by ROS from the HVL cells. These findings provide new insights into the distinct DNA damage and repair responses resulting from different viral loads in HCV-infected cells.