TY - JOUR
T1 - PEMT mediates hepatitis c virus-induced steatosis, explains genotype-specific phenotypes and supports virus replication
AU - Abomughaid, M.
AU - Tay, E.S.E.
AU - Pickford, R.
AU - Malladi, Chandra
AU - Read, Scott A.
AU - Coorssen, Jens R.
AU - Gloss, B.S.
AU - George, J.
AU - Douglas, M.W.
PY - 2023
Y1 - 2023
N2 - The hepatitis C virus (HCV) relies on cellular lipid pathways for virus replication and also induces liver steatosis, but the mechanisms involved are not clear. We performed a quantitative lipidomics analysis of virus-infected cells by combining high-performance thin-layer chromatography (HPTLC) and mass spectrometry, using an established HCV cell culture model and subcellular fractionation. Neutral lipid and phospholipids were increased in the HCV-infected cells; in the endoplasmic reticulum there was an ~four-fold increase in free cholesterol and an ~three-fold increase in phosphatidyl choline (p < 0.05). The increase in phosphatidyl choline was due to the induction of a non-canonical synthesis pathway involving phosphatidyl ethanolamine transferase (PEMT). An HCV infection induced expression of PEMT while knocking down PEMT with siRNA inhibited virus replication. As well as supporting virus replication, PEMT mediates steatosis. Consistently, HCV induced the expression of the pro-lipogenic genes SREBP 1c and DGAT1 while inhibiting the expression of MTP, promoting lipid accumulation. Knocking down PEMT reversed these changes and reduced the lipid content in virus-infected cells. Interestingly, PEMT expression was over 50% higher in liver biopsies from people infected with the HCV genotype 3 than 1, and three times higher than in people with chronic hepatitis B, suggesting that this may account for genotype-dependent differences in the prevalence of hepatic steatosis. PEMT is a key enzyme for promoting the accumulation of lipids in HCV-infected cells and supports virus replication. The induction of PEMT may account for virus genotype specific differences in hepatic steatosis.
AB - The hepatitis C virus (HCV) relies on cellular lipid pathways for virus replication and also induces liver steatosis, but the mechanisms involved are not clear. We performed a quantitative lipidomics analysis of virus-infected cells by combining high-performance thin-layer chromatography (HPTLC) and mass spectrometry, using an established HCV cell culture model and subcellular fractionation. Neutral lipid and phospholipids were increased in the HCV-infected cells; in the endoplasmic reticulum there was an ~four-fold increase in free cholesterol and an ~three-fold increase in phosphatidyl choline (p < 0.05). The increase in phosphatidyl choline was due to the induction of a non-canonical synthesis pathway involving phosphatidyl ethanolamine transferase (PEMT). An HCV infection induced expression of PEMT while knocking down PEMT with siRNA inhibited virus replication. As well as supporting virus replication, PEMT mediates steatosis. Consistently, HCV induced the expression of the pro-lipogenic genes SREBP 1c and DGAT1 while inhibiting the expression of MTP, promoting lipid accumulation. Knocking down PEMT reversed these changes and reduced the lipid content in virus-infected cells. Interestingly, PEMT expression was over 50% higher in liver biopsies from people infected with the HCV genotype 3 than 1, and three times higher than in people with chronic hepatitis B, suggesting that this may account for genotype-dependent differences in the prevalence of hepatic steatosis. PEMT is a key enzyme for promoting the accumulation of lipids in HCV-infected cells and supports virus replication. The induction of PEMT may account for virus genotype specific differences in hepatic steatosis.
UR - https://hdl.handle.net/1959.7/uws:73636
U2 - 10.3390/ijms24108781
DO - 10.3390/ijms24108781
M3 - Article
SN - 1661-6596
VL - 24
JO - International Journal of Molecular Sciences
JF - International Journal of Molecular Sciences
IS - 10
M1 - 8781
ER -
