Immunohistochemical study of NF-E2-related factor 2 (Nrf2) in an end-to-end anastomosis of the rat carotid artery

IntroductionThe detailed process and underlying mechanism of stenosis following microvascular anastomoses remains unclear. NF-E2-related factor 2 (Nrf2), is a pleiotropic regulator of cell survival and plays a crucial role in modulating acute inflammatory response. An animal experiment was employed to obtain new information on the histomorphological changes and distribution of Nrf2 in anastomoses.MethodsAn end-to-end anastomotic model in rat carotid arteries was carried out. The stoma was examined by H&E staining and immunostaining to evaluate histomorphological change as well as the intensity of anti-Nrf2 and а-SMA staining.ResultsCompression, dehiscence and inflammatory cells infiltration were often seen following vessel anastomoses. Inflammatory cells infiltrate was reduced and the granulation tissue fibrosis and endothelium reforming become apparent with times. Marked tunica media hyperplasia consisting of a packed layer of neogenetic smooth muscle cell was present around the anastomosis. Nrf2 expression was upregulated after the operation and was mainly distributed in the neogenetic smooth muscle cells.ConclusionStenosis following the micro-artery anastomoses may be mainly due to the progressive myointimal hyperplasia in the media of the arteries. Nrf2 was involved in the pro-inflammatory stress during the vascular morphogenesis/angiogenesis and can be a valuable tool for studying the process of wound healing.