Tubular epithelial cells transfected with hHGF counteracts monocyte chemotactic protein-1 up-regulation after hypoxia/reoxygenation insult

Abstract

Acute kidney injury (AKI) which is mainly produced by nephrotoxic or ischemic insults is correlated with a high mortality and morbidity. Proximal tubular epithelial cells (PTEC) play a major role. They are the main target of ischemia/reperfusion injury. PTECs have also been proposed as the effectors of AKI reversibility, but also as the creator of the inflammatory milieu: cytokine, chemokine, and complement expression. An important chemokine implicated in this process is monocyte chemotactic protein-1 (MCP-1) due to its ability to recruit and activate monocytes. Hepatocyte growth factor (HGF) is a pleiotropic factor with mitogenic, anti-apoptotic, and proliferative effects which has recently been studied for its anti-inflammatory and antifibrogenic effects. Our aim was to evaluate the potential inflammatory effect of hypoxia and reoxygenation on rat PTECs. We created a stable human HGF (hHGF) expressing PTEC line that emulated in vivo transfection and analyzed the role of this cell type in the induction and reversibility of AKI. Our results showed the efficiency of transfection with the hHGF gene to promote sustained expression of the protein in the medium (7627.13 ± 1144.078 to 8211.3 ± 795.37 pg/mL). When rat PTECs were under a hypoxia/reoxygenation insult, MCP-1 was highly overexpressed (4479.3 ± 154.3 pg/mL of protein and 5.099 ± 1.23 times control gene expression). Transfected cells abrogated this effect (288.7 ± 13.5 pg/mL and 1.169 ± 0.0759 times control). In conclusion, we observed that the hypoxia/reoxygenation insult stimulated MCP-1 protein secretion in PTECs and that PTECs which were stably transfected and overexpressing hHGF abrogated the inflammatory reaction mediated by hypoxia/reoxygenation, being a suitable model for later studies.