Caspase-3 is Involved in IFN-γ- and TNF-α-Mediated MIN6 Cells Apoptosis via NF-κB/Bcl-2 Pathway

Abstract

TNF-α and IFN-γ are the major pro-inflammatory cytokines in the β-cell destruction. However, the underlying mechanism remains unclear. The present study used a murine insulinoma cell line MIN6 for further investigation of the effect of Caspase-3 on the cytokines-induced pancreatic β-cell apoptosis and analyzed the mechanisms involved in the activation of Caspase-3. It was showed that the combination of IFN-γ and TNF-α significantly reduced the viability of MIN6 cells and the observed cells growth inhibition was due to cell apoptosis as judged by the morphological changes under a confocal laser scanning microscopy and FACS assay of Annexin-V/7-AAD double staining. Accompanying with NF-κB activation and Bcl-2 downregulation, both the cleaved Caspase-3 and PARP, a known substrate of Caspase-3 in vivo, were observed at 24 and 12 h, respectively, after cells exposure to IFN-γ and TNF-α treatment. Pretreatment of Caspase-3 inhibitors remarkably attenuated IFN-γ- and TNF-α-induced cells apoptosis. Inhibition of NF-κB activation led to the increase in Bcl-2 expression, a significant attenuation in Caspase-3 activity, and an obvious amelioration in cells viability in IFN-γ- and TNF-α-treated MIN6 cells. Taken together, our results indicate that Caspase-3 is critical for the induction of MIN6 cells apoptosis and it's activation is further confirmed to be related to the NF-κB-mediated Bcl-2 downregulation, which may be the underlying mechanism of IFN-γ- and TNF-α-mediated MIN6 cells apoptosis.

Retracted: Baicalin prevents tumor necrosis factor‐α−induced apoptosis and dysfunction of pancreatic β‐cell line Min6 via upregulation of miR‐205

“…2,3 It was found that the products of cytotoxic T cells and soluble T cells, like interferon-γ, interleukin-1β, and tumor necrosis factor-α (TNF-α), caused destruction of them. 4 Therefore, the TNF-α-induced injury model in pancreatic β-cells was used for our study.…”

Retracted: Bilobalide alleviates tumor necrosis factor‐alpha‐induced pancreatic beta‐cell MIN6 apoptosis and dysfunction through upregulation of miR‐153

“…Animal experiments implied that TNF‐α suppressed progression to T1DM. Abundant studies demonstrated that TNF‐α could induce apoptosis in various cells, such as HELA cells (Rajmani et al, ), H9c2 cells (Zhao et al, ), and MIN6 cells (Z. H. Cao et al, ). Moreover, TNF‐α is investigated to involve in insulin secretion.…”

LIGHT/IFN‐γ triggers β cells apoptosis via NF‐κB/Bcl2‐dependent mitochondrial pathway

“…The NF-jB signalling pathway has been shown to regulate expression of multiple genes that play key roles in cell survival or apoptosis [33,34]. In some cases, NF-jB activation inhibits cell death, but can promote cell death in certain cell types, such as in beta cells [5,25] and gastric epithelial cells [35]. Our results demonstrate that LIGHT combined with IFN-c leads to a decrease in cytoplasmic NF-jB p65 levels, but an increase in nuclear NF-jB p65 expression in MIN6 cells, suggesting that NF-jB is activated by IFN-c and LIGHT Notably, consistent with the findings observed in LIGHT-and IFNc-mediated apoptosis of MDA-MB-231 breast cancer cells [16], although extensive caspase activation of caspases-3, -8 (data not shown) and -9, were observed, treatment with a broad range caspase inhibitor and a caspase-3 inhibitor (data not shown) do not completely block LIGHT/IFNc-induced apoptosis in MIN6 cells.…”