Pretreatment with paricalcitol attenuates level and expression of matrix metalloproteinases in a rat model of renal ischemia-reperfusion injury

Background: Ischemia-reperfusion injury (IRI) is a leading cause of acute kidney injury (AKI). The inflammatory response that drives IRI involves upregulation of matrix metalloproteinases (MMPs), which results in proteolytic degradation of renal microvascular matrix. Evidence suggests a potential protective role of active vitamin D on ischemic injury by downregulating MMPs. In the present study, we aimed to determine the expression and level of MMP-2 and MMP-9 in renal IRI model and the potential beneficial effect of paricalcitol on both level and expression of MMPs and tubular injury caused by IRI. Materials and methods: 20 Wistar albino rats were divided into three groups: sham-operated, ischemia-reperfusion, and paricalcitol-pretreated. IRI model was induced by bilateral clamping of renal arteries for 45 minutes followed by 24 hours of reperfusion. The analysis of serum creatinine and levels of MMPs were performed after 24 hours of IRI. The effects of paricalcitol on the quantity and expression of MMP-2 and MMP-9 in renal tubular epithelial cells were investigated by enzyme-linked immunosorbent assay and immunohistochemistry, respectively. The pathological examinations were performed to score tubular damage by light microscopy. Results: Creatinine levels decreased in the paricalcitol group, although this was not proven to be significant. Rats in the paricalcitol group showed significant decrease in both level and expression of MMPs and in tubular injury scores as compared to the IRI group. Conclusion: Paricalcitol may attenuate renal tubular injury caused by IRI by decreasing both level and expression of MMPs. Further studies are required to investigate the interplay between activated vitamin D and MMPs in AKI