The Recombinant Human Secretory Leukocyte Protease Inhibitor (SLPI) protects cardiac fibroblasts injury against an in vitro ischemia/reperfusion injury

Abstract

One of the major causes of cardiac cell death is an over-secretion of protease enzymes surrounding the ischemic tissue. Therefore, the inhibition of protease activity could be used as an alternative strategy to prevent the expansion of injury. In the present study, we investigated the pre-treatment effects of recombinant human Secretory Leukocyte Protease Inhibitor (rhSLPI) on simulated-ischemia/reperfusion (sI/R)-induced cardiac fibroblast cell death. The adult rat cardiac fibroblasts (ARCFs) were isolated from adult male Wistar rats (n=6). Isolated cells were characterized by through the detection of vimentin. Simulated ischemia/reperfusion was performed by incubating cells in an ischemic buffer for 40 min which were then reperfused with completed medium for 24 h. The cell viability was determined by MTT assay. The intracellular reactive oxygen species (ROS) production was measured by dichlorodihydrofluorescein assay. Activation of p38 MAPK was determined by Western blotting. The results showed that pre-treatment of rhSLPI at the concentrations of 400, 600, 800, and 1000 ng/mL significantly reduced sI/R-induced ARCFs death as well as intracellular ROS production. Moreover, pre-treatment of rhSLPI could reduce p38 MAPK activation and pro-apoptotic protein-Bax levels. In conclusion, pre-treatment of rhSLPI shows cardioprotective effects against sI/R-induced cardiac fibroblast cell death by reducing oxidative stress and reducing p38 MAPK activation.