Study of the role of epigenetic factor LSD1 in hepatitis C virus infection

Postgraduate Thesis uoadl:2837119 284 Read counter

Unit:
Κατεύθυνση Εφαρμογές της Βιολογίας στην Ιατρική
Library of the School of Science
Deposit date:
2018-12-06
Year:
2018
Author:
Papadopoulou Georgia
Supervisors info:
Γαϊτανάκη Αικατερίνη, Καθηγήτρια Φυσιολογίας Ζώων, Τμήμα Βιολογίας, Εθνικό και Καποδιαστριακό Πανεπιστήμιο Αθηνών
Γεωργοπούλου Ουρανία, Υπεύθυνη Εργαστηρίου Μοριακής Ιολογίας, Ελληνικό Ινστιτούτο Παστέρ
Παπαζαφείρη Παναγιώτα, Αναπληρώτρια Καθηγήτρια Φυσιολογίας Ζώων, Τμήμα Βιολογίας, Εθνικό και Καποδιαστριακό Πανεπιστήμιο Αθηνών
Original Title:
Μελέτη του επιγενετικού παράγοντα LSD1 κατά τη λοίμωξη από τον ιό της ηπατίτιδας C
Languages:
Greek
Translated title:
Study of the role of epigenetic factor LSD1 in hepatitis C virus infection
Summary:
Hepatitis C is an infectious disease caused by the hepatitis C virus (HCV) that primarily affects the liver. At the same time, patients with chronic hepatitis C are over 170 million and are a high-risk group for cirrhosis and HCC. Statistically, after initial infection with HCV, 75-85% of patients develop chronic disease. Of patients with chronic hepatitis C, 20-30% develop cirrhosis after 20-25 years of initial infection. Finally, from patients with cirrhosis associated with HCV, 2-7% develop HCC. To date, over 300,000 deaths have been reported, most due to cirrhosis and hepatocellular carcinoma (HCC). HCV belongs to the genus Hepacivirus of the Flaviviridae family. The viral particle consists of a 10 kb single-stranded RNA molecule surrounded by an icosahedral protective shell of protein, the capsid. The genome of HCV encodes a 3000 amino acid polyprotein. The genome includes an open reading frame (ORF) which translates through an internal ribosome entry site (IRES) at the 5 'end, and is surrounded by the 5' and 3 'untranslated regions (UTRs). The resulting polyprotein is then matured by proteolysis and structural proteins, core, E1 and E2, and non-structural proteins, i.e. p7, NS2, NS3, NS4A, NS4B, NS5A and NS5B, are produced. The LSD1 protein (Lysine-specific demethylase 1, also KDM1A, AOF2, BHC110, KIA0601) is a nuclear enzyme that catalyzes the removal of methyl groups from histone and non-histone lysine residues, thereby affecting the expression of molecules that regulate important cell functions. Recent studies indicate that LSD1 plays an active role in many viral processes such as viral replication, viral protein expression, as well as viral latency. Viruses in order to support their proliferation entirely use the epigenetic mechanism of host cells. At the same time, LSD1 is overexpressed in HCC tissues and its expression levels are directly related to the tumor stage. Also, we know how important role lipid metabolism plays in HCV replication in hepatocytes and that LSD1 is one of the main regulators of cellular energy metabolism. Based on the above, in the present work we constructed Huh7.5 and HepG2 cell clones overexpressing LSD1, using a plasmid expression vector carrying the LSD1 coding sequence. We then infected the Huh7.5 overexpressing clones with HCV viruses (JFH1 and HCV-3a strain genotypes) in order to investigate how LSD1 overexpression affects viral replication compared to infected Huh7.5 cells. At the same time, we studied the change in LSD1 levels when infecting Huh7.5 cells with HCV-JFH1 and HCV-3a genotypes.We noticed that the expression of LSD1, after infection with the two genotypes above, increases in the first 48 hours and then returns to normal levels. We also noticed that when HCV-JFH1 genotype infects a cell clone overexpressing LSD1, the peak of viral proliferation was 14-fold higher than control cultures, while there was a delay in viral replication from 48 to 72 hours. In contrast, the HCV-3a genotype exhibits increased replication in clone Hu1b compared to control culture during the first 24 hours of infection. Subsequently, there is significant inhibition of the viral replication rate, which is almost zero at 48 hours and recurs to a small extent until the end of the infection. There are studies that highlight the role of LSD1 in viral infections. Some of those are referred to as a tool used by the virus to survive and others are referred to as the host cell’s defense tool. So far, there is not enough data to elucidate the interaction between LSD1 and HCV virus. The present study has opened new ways to better understand the interaction of the HCV virus with the host cell, which may in future be a valuable tool for a better antiviral therapy targeting LSD1 to treat hepatitis C and HCC.
Main subject category:
Science
Keywords:
molecular virology, hepatitis C, epigenetic factor, LSD1 Hepatitis C Virus HCV
Index:
No
Number of index pages:
3
Contains images:
Yes
Number of references:
301
Number of pages:
153
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