Prostaglandin A1 inhibits the replication of bovine viral diarrhea virus

ABSTRACT Bovine viral diarrhea virus can cause acute disease in livestock, leading to economic losses. We show that Prostaglandin A1 inhibits bovine viral diarrhea virus replication in Madin-Darby bovine kidney cells (94% inhibition using 5 µg/mL). Light and electron microscopy of infected cells shows that Prostaglandin A1 also prevents virus-induced vacuolization, but at higher concentrations (10 µg/mL).

Prostaglandin A1 triggers Mayaro virus inhibition and heat shock protein 70 expression in an epithelial cell model

Abstract INTRODUCTION: The Mayaro virus (MAYV), which is an arbovirus closely related to the Chikungunya virus, causes a dengue-like acute illness that is endemic to Central and South America. We investigated the anti-MAYV activity of prostaglandin A1 (PGA1), a hormone which exhibits antiviral activity against both ribonucleic acid (RNA) and deoxyribonucleic acid (DNA) viruses. Further, we examined the effects of inducting the stress protein HSP70 following PGA1 treatment. METHODS: Hep-2 cells infected with MAYV were treated with PGA1 (0.1-6μg/ml) 12h before infection and for different periods post-infection. Inhibition of viral replication inhibition was analyzed via viral titer determination, whereas the effect of PGA1 on viral morphogenesis was examined via transmission electron microscopy (TEM). Autoradiography (with 35S methionine labeling) and western blotting were used to assess the effect of PGA1 treatment on viral and cellular protein synthesis, and on HSP70 induction, respectively. RESULTS: PGA1 strongly reduced viral replication in Hep-2 cells, particularly when added during the early stages of viral replication. Although PGA1 treatment inhibited viral replication by 95% at 24 hours post-infection (hpi), viral structural protein synthesis was inhibited only by 15%. TEM analysis suggested that PGA1 inhibited replication before viral morphogenesis. Western blot and densitometry analyses showed that PGA1 treatment increased HSP70 protein levels, although this was not detectable via autoradiography. CONCLUSIONS: PGA1 inhibits MAYV replication in Hep-2 cells at early stages of viral replication, prior to production of viral structural proteins, possibly via HSP70 induction.

Prostaglandin A2 Induces Caspase-independent Apoptosis in Hepatocellular Carcinoma Cells / 대한간학회지

BACKGROUND/AIMS: Prostaglandin (PG) A2 has been reported to inhibit the growth of hepatocellular carcinoma cells via activation of apoptosis, although the molecular mechanisms involved have not been clarified, yet. To investigate the mechanism of the PGA2-induced apoptosis, we analyzed the activation of caspases during the apoptosis of hepatoma cell lines. METHODS: Induction of apoptosis by PGA2 in hepatoma cell lines, Hep 3B and Hep G2, was assessed by DAPI staining of nuclei and agarose gel electrophoresis of genomic DNA. The involvement of caspases was analyzed by immunoblot analysis of poly ADP-ribose polymerase (PARP) and by checking the effect of caspase inhibitors on PGA2-induced apoptosis. RESULTS: PGA2 inhibited the growth of Hep 3B and Hep G2 cells, accompanying nuclear condensation and fragmentation, and genomic DNA laddering, which are the hallmarks of apoptosis. The PARP was not cleaved during the apoptosis of Hep 3B and Hep G2 cells and caspase inhibitors such as z-VAD-Fmk and z-DEVD-Fmk exerted no effect on the PGA2-induced apoptosis. CONCLUSIONS: These results suggest that PGA2 induces apoptosis in Hep 3B and Hep G2 cells via caspase-independent pathway.

Sox-4 is a positive regulator of Hep3B and HepG2 cells' apoptosis induced by prostaglandin (PG)A2 and 12-PGJ2

We reported earlier that expression of Sox-4 was found to be elevated during prostaglandin (PG) A2 and delta(12)-PGJ(12) induced apoptosis in human hepatocarcinoma Hep3B cells. In this study, the role of Sox-4 was examined using human Hep3B and HepG2 cell lines. Sox-4 induction by several apoptotic inducer such as A23187 (Ca(2+) ionophore) and etoposide (topoisomerase II inhibitor) and Sox-4 transfection into the cells were able to induce apoptosis as observed by the cellular DNA fragmentation. Antisense oligonucleotide of Sox-4 inhibited the induction of Sox-4 expression and blocked the formation of DNA fragmentation by PGA(2) and delta(12)-PGJ(12) in Hep3B and HepG2 cells. Sox-4-induced apoptosis was accompanied with caspase-1 activation indicating that caspase cascade was involved in this apoptotic pathway. These results indicate that Sox-4 is involved in Hep3B and HepG2 cells apoptosis as an important apoptotic mediator.

Inhibition of Mayaro virus replication by prostagandin A1 in Aedes albopictus cells

Prostaglandin Al (PGA1) inhibits Mayaro virus replication in Aedes albopictus cells at nontoxic doses to uninfected cells . At 10 ug/ml, PGA1 decreases virus production by 90 (per cent). The presence of PGA1 during virus adsorption, with no treatment after infection, reduces virus yield by 41 (per cent). Antiviral activity is observed even when treatment starts at one or two hours post-infection. However, in cells pre-treated with PGA1 during 24 hours, virus replication is not impaired. Thus, events ocurring during initial stages of infection and after virus adsorption and penetration must be the target of PGA1 action. SDS-PAGE analysis of 35S-methionine labelled proteins shows that PGA1 inhibits the synthesis of viral proteins and induces the synthesis of polypeptides with molecular weight of 70 kDa, 57 kDa and 23 kDa. In cells pre-treated with actinomycin D the induction of those proteins is suppressed. In addition, actinomycin D treatment prevents PGA1 antiviral activity, indicating that PGA1-induced stress proteins are probably involved in this mechanism

Inhibition of Mayaro virus replication by prostaglandin A1 and B2 in Vero cells

The effect of prostaglandins (PGA1 and PGB2) on the replication of Mayaro virus was studied in Vero cells. PGA1 and PGB2 antiviral activity was found to be dose-dependent. However, while 10 µg/ml PGB2 inhibited virus yield by 60 percent, at the same dose PGA1 suppressed virus replication by more than 90 percent. SDS-PAGE analysis of [35S]-methionine-labelled proteins showed that PGA1 did not alter cellular protein synthesis. In infected cells, PGA1 slightly inhibited the synthesis of protein C, while drastically inhibiting the synthesis of glycoproteins E1 and E2

Effect of prostaglandin A1 in the induction of stress proteins in Aedes albopictus cells

Prostaglandin are natural fatty acid derivatives with diverse physiological effects, including immune function and the control of cell growth. While the action of prostaglandins in the induction of stress proteins in vertebrate cells in well documented, their functions in invertebrate cells have been poorly investigated. The purpose of the present study was to investigate the effect of prostaglandin A1 (PGA1; 0.25, 1.25 and 12.5 mug/ml) on protein synthesis during the growth of Aedes albopictus cells. We found that PGA1 stimulates the synthesis of several polypeptides with molecular masses of 87,80,70,57,29,27 and 23 kDa in Aedes albopictus cells. When the protein induced by PGA1 and those induced by heat treatment were compared by polyacrylamide gel electrophoresis, PGA1 was found to induce the stress proteins. The HSP70 family and the low-molecular weight polypeptides (29 and 27 kDa, respectively) were induced by PGA1 in the lag phase. We lso observed that PGA1 is able to induce a 23-kDa polypeptide independently of the growth phase of the cell.

Prostaglandin A1, inhibits replication of Mayaro virus in Aedes albopictus cells

Prostaglandin A1 (PGA1) reduced Mayaro virus replication in Aedes albopictus (mosquito) cells in culture. The highest nontoxic dose of PGA1, 7.5µM, decreased virus production by 90 percent. In Mayaro virus-=infected cells, PGA1 inhibited virus-specific protein synthesis. However, in mock-infected cells the presence of PGA, stimulated the synthesis of several proteins with molecular masses of 70, 57 and 23 kDa, respectively. The data obtained from this study show that PGA1 plays a role in the metabolic regulation of Aedes albopictus cells, blocking the synthesis of Mayaro virus and inducing the synthesis of cellular polypeptides