Increased expression of phosphoenolpyruvate carboxykinase cytoplasmic isoform by hepatitis B virus X protein affects hepatitis B virus replication

Artificial Neural Network-Based Study Predicts GS-441524 as a Potential Inhibitor of SARS-CoV-2 Activator Protein Furin: a Polypharmacology Approach

Furin, a pro-protein convertase, plays a significant role as a biological scissor in bacterial, viral, and even mammalian substrates which in turn decides the fate of many viral and bacterial infections along with the numerous ailments caused by cancer, diabetes, inflammations, and neurological disorders. In the wake of the current pandemic caused by the virus SARS-CoV-2, furin has become the center of attraction for researchers as the spike protein contains a polybasic furin cleavage site. In the present work, we have searched for novel inhibitors against this interesting human target from FDA-approved antiviral. To enhance the selection of new inhibitors, we employed Kohonen's artificial neural network-based self-organizing maps for ligand-based virtual screening. Promising results were obtained which can help in drug repurposing and network pharmacology studies can address the errors generated due to promiscuity/polypharmacology. We found 15 existing FDA antiviral drugs having the potential to inhibit furin. Among these, six compounds have targets on important human proteins (LDLR, FCGR1A, PCK1, TLR7, DNA, and PNP). The role of these 15 drugs inhibiting furin can be established by studying further on patients infected with number of viruses including SARS-CoV-2. Here we propose two promising candidate FDA drugs GS-441524 and Grazoprevir (MK-5172) for repurposing as inhibitors of furin. The best results were observed with GS-441524.

Bombyx mori nucleopolyhedrovirus downregulates transcription factor BmFoxO to elevate virus infection

Forkhead-box O (FoxO) is the primary transcriptional effector of the insulin-like signaling pathway that enhances gluconeogenesis through transcriptional activation of PEPCK and G6Pase in mammals. We have previously demonstrated the involvement of phosphoenolpyruvate carboxykinase (BmPEPCK-2) in antiviral immunity against the multiplication of Bombyx mori nuclearpolyhedrosisvirus (BmNPV) in silkworm. Therefore, we speculated that BmFoxO might suppress BmNPV by regulating the expression of PEPCK in silkworm. In the present study, we found that the expression of BmFoxO decreased after BmNPV infection in Bombyx mori; this finding was consistent with BmPEPCK-2 expression. In addition, the expression of BmFoxO was altered, and it was found that reduced expression of BmFoxO (dsBmFoxO) downregulated the expression of BmPEPCK-2 and increased the viral fluorescence and content in silkworm embryonic cell line BmE cells, and vice versa. BmFoxO could upregulate the expression of BmPEPCK-2 by binding to the BmPEPCK-2 promoter. Moreover, overexpression of BmFoxO significantly increased the expression of autophagy genes ATG6/7/8 after infection with BmNPV, consistent with BmPEPCK-2. These results indicate that BmNPV downregulates transcription factor BmFoxO to elevate virus infection, and BmFoxO overexpression upregulates BmPEPCK-2 expression and enhances silkworm antiviral resistance.

Predictive value of plasmacytoid dendritic cells and Toll-like receptor-9 regarding the treatment efficacy of interferon-α in HBeAg-positive chronic hepatitis B patients

Hepatitis B virus (HBV) infection represents a public health threat and a challenge for the medical community. Untimely treatment may lead to liver cirrhosis and even liver cancer. At present, the major treatment for hepatitis B e antigen (HBeAg)-positive chronic hepatitis B patients includes administration of interferon-α (IFN-α), which has anti-viral and immunomodulatory effects. Plasmacytoid dendritic cells (pDCs) and Toll-like receptor-9 (TLR-9) have important roles in anti-viral therapy. However, their predictive value regarding the efficacy of IFN-α treatment of HBeAg-positive chronic hepatitis B (CHB) patients has remained elusive. A total of 178 patients with CHB and HBeAg-positive status, who had not received any previous anti-HBV treatment, were enrolled in the present study. All patients were treated with IFN-α. HBV DNA load, hepatitis B surface antigen and serum alanine aminotransferase were measured prior to and following 48 weeks of treatment. According to HBV levels, the patients were divided into a response group and non-responders group. To determine the amount of pDCs, blood dendritic cell antigen 2 (BDCA-2)- and immunoglobulin-like transcript 7 (ILT7)-expressing cells in liver biopsies were detected using immunohistochemistry. TLR-9 expression in peripheral blood mononuclear cells was determined by reverse transcription-quantitative PCR. There was no significant difference in the proportion of pDCs (BDCA-2; ILT7) and TLR-9 mRNA expression between the response group and the non-responders group prior to IFN-α treatment. After IFN-α treatment, BDCA-2, ILT7 and TLR-9 mRNA expression was obviously increased in the response group compared with that in the non-responders group (P<0.05). Increased expression of BDCA-2, ILT7 and TLR-9 mRNA was negatively correlated with HBV DNA (P<0.05). Increased levels of pDCs and TLR-9 were negatively correlated with HBV DNA, and were thus capable of predicting the IFN-α treatment response in patients with CHB and HBeAg-positive status.