Stanniocalcin-1 protects bovine intestinal epithelial cells from oxidative stress-induced damage

Chronic enteritis can produce an excess of reactive oxygen species resulting in cellular damage. Stanniocalcin-1(STC-1) reportedly possesses anti-oxidative activity, the aim of this study was to define more clearly the direct contribution of STC-1 to anti-oxidative stress in cattle. In this study, primary intestinal epithelial cells (IECs) were exposed to hydrogen peroxide (H₂O₂) for different time intervals to mimic chronic enteritis-induced cellular damage. Prior to treatment with 200 µM H₂O₂, the cells were transfected with a recombinant plasmid for 48 h to over-express STC-1. Acridine orange/ethidium bromide (AO/EB) double staining and trypan blue exclusion assays were then performed to measure cell viability and apoptosis of the cells, respectively. The expression of STC-1 and apoptosis-related proteins in the cells was monitored by real-time PCR and Western blotting. The results indicated that both STC-1 mRNA and protein expression levels positively correlated with the duration of H₂O₂ treatment. H₂O₂ damaged the bovine IECs in a time-dependent manner, and this effect was attenuated by STC-1 over-expression. Furthermore, over-expression of STC-1 up-regulated Bcl-2 protein expression and slightly down-regulated caspase-3 production in the damaged cells. Findings from this study suggested that STC-1 plays a protective role in intestinal cells through an antioxidant mechanism.