EPC

Heterologous Overexpression of Human PML-IV in EPC Cells Results in Features of Premature Senescence

Fish cell lines show resistance to premature senescence, partly because fish genomes lack the p16INK4a/Arf locus. Other factors, such as the absence of PML NBs, may also be involved. In this study, human PML-IV was heterologously expressed in the Epithelioma papulosum cyprini cell line to induce the formation of PML NB-like structures. Futami et al. explored the link between the absence of PML NBs and resistance to senescence in fish cells.

They transfected EPC cells with fluorescence-fused human PML-IV to induce PML NB formation and analyzed the cells using fluorescence microscopy (Fig. 1). Speckled PML NB-like structures were observed, but nuclear morphology remained unchanged. Phase contrast microscopy revealed that PML-IV-transfected cells exhibited the large, flattened morphology typical of senescent cells. They then assessed several senescence markers. SA-β-Gal activity increased (Fig. 2a), and an MTT assay confirmed senescence-like proliferation suppression (Fig. 2b). However, lmnb1 gene expression, which typically decreases in senescent cells, did not significantly change (Fig. 2c). Additionally, p53 activation and increased expression of its target gene p21 (cdkn1a) were not observed (Fig. 2d and 2e). These findings may explain the absence of nuclear morphological changes.

Exploring the Antiproliferative, Cytotoxic and Proapoptotic Properties of Virkon-S in Carp Epithelioma Papulosum Cells

Cyprinus carpio is a major farmed fish species in Turkey, but viral diseases such as Epithelioma papulosum cyprini (EPC) cause significant economic losses. Traditional disinfectants have potential genotoxic and cytotoxic effects, so non-toxic alternatives are needed. Virkon-S is a biocompatible disinfectant recommended by FAO, but its effects on EPC have not been studied.

Izgördü et al. reported the cytotoxic, antiproliferative, and proapoptotic effects of Virkon-S in EPC cells by MTT assay, confocal and TEM microscopy, and Annexin-V and Caspase 3/7 analysis. IC₅₀ values were 494.3 ppm (24 h) and 1198.3 ppm (48 h) in Virkon-S-treated EPC cells. The viability of EPC cells was significantly reduced as the increasing concentration and time of Virkon-S. These results showed that the cytotoxicity of Virkon-S is concentration- and time-dependent (Fig. 3). Annexin-V staining clearly demonstrated that Virkon-S induced apoptosis type cell death. The total percentage of apoptotic cells in Virkon-S-treated EPC cells was 20.74% while in control (Fig. 4A and B). Early apoptotic cells were found to be 4.01% in control and 19.97% in treated cells while late apoptotic cells were found to be 0.77% (Fig. 4B). The GraphPad Prism 8.0 program was used for statistical analysis (Fig. 4C).