Sulforaphane alleviates cadmium-induced toxicity in human mesenchymal stem cells through POR and TNFSF10 genes expression

Abstract

Sulforaphane is a dietary compound possessing anti-inflammatory, antioxidant, anti-diabetic, anti-carcinogenic, and anti-aging properties. The role of sulforaphane in the context of cadmium (Cd)-induced toxicity through the alteration of nuclear morphology, mitochondrial membrane potential, and gene expression patterns, however, remains unclear. Thus, we assessed the protective role of sulforaphane against Cd-induced nuclear and mitochondrial damage in human mesenchymal stem cells (hMSCs). Cells were exposed to Cd and sulforaphane, either alone or in combination, for 48 h. The cell viability was assessed by adopting MTT assay. The nuclear morphology was investigated using Acridine orange/Ethidium bromide (AO/EB) dual staining and Hoechst staining. The mitochondrial membrane potential loss and lysosomal staining were analyzed using JC-1 staining and LysoRed staining respectively. The gene expression was studied using quantitative real-time PCR analysis. After 48 h of exposure to Cd, the viability of hMSCs decreased in a dose-dependent manner. In contrast, a single treatment with the phytochemical sulforaphane did not cause any remarkable reduction in hMSC viability. Combined treatment with Cd and sulforaphane resulted in a marked recovery in cell viability compared to that observed in cells treated with Cd alone. Analysis of nuclear morphology indicated that Cd induced necrotic cell death, while combined Cd and sulforaphane treatment prevented nuclear morphology changes. Cd ions also significantly attenuate the mitochondrial membrane potential (MMP) and alter gene expression in hMSCs; however, we observed that sulforaphane improves MMP under conditions of Cd-sulforaphane co-treatment of hMSCs. The gene expression results indicate that POR, TNFRSF1A and TNFSF10 genes expression are significantly upregulated by Cd-sulforaphane co-treatment than Cd or sulforaphane treatment alone. Our study results clearly indicate that sulforaphane can protect hMSCs against Cd-induced changes in nuclear morphology, attenuation of MMP, and alteration of gene expression patterns. Thus, intake of sulforaphane-enriched vegetables and fruits will be helpful to overcome Cd-induced toxicity in humans.