Objective To investigate the effect of Danhuangsan on high glucose-induced vascular endothelial cell injury based on PINK 1/Parkin signaling pathway,and to explore its specific mechanism.Methods Human um-bilical vein endothelial cells were cultured in vitro and randomly divided into control group,growth factor group,Danhuangsan group,high glucose group,high glucose+growth factor group,high glucose+Danhuangsan group,with 3 cases in each group,treated for 48 hours.Cell scratch test was used to detect cell migration rate,and Transwell test was used to detect cell invasion rate.Immunofluorescence was used to detect the expression of anti-apoptotic protein Bcl-2,Beclin-1 and pro-apoptotic protein Bax.Western blot was used to detect the protein expression levels of PINK 1,Parkin and LC 3-Ⅱ.Results Cell scratch test and Transwell test showed that under normal environment and high glucose treatment,Danhuangsan could reduce the cell migration and invasion rate(P＜0.05).Immunofluorescence assay showed that under normal environment and high glucose treatment,Danhuang-san up-regulated the expression levels of Bcl-2 and Beclin-1 protein in cells(P＜0.05).Western blot results showed that under normal environment and high glucose treatment,Danhuangsan increased the protein expression levels of PINK 1,Parkin and LC 3-Ⅱ in cells and down-regulated the expression levels of Bax protein(P＜0.05),and the effects of Danhuang powder were significantly better than those of blank serum and growth factor(P＜0.05).Conclusion Danhuangsan can alleviate high glucose-induced endothelial cell injury by activating PINK 1/Parkin pathway,and the mechanism may be related to promoting mitophagy and enhancing the repair of damage.

Isopeptide bond-mediated molecular superglue is the irreversible covalent bond spontaneously formed by the side chains of lysine (Lys) and asparagine/aspartic acid (Asn/Asp) residues. The peptide-peptide interaction is specific, stable, and can be achieved quickly without any particular physicochemical factor. In the light of recent progress by domestic and foreign researchers, here we summarize the origin, assembly system and mechanism of isopeptide bond reaction, as well as the molecular cyclization and protein topological structure mediated by it. The prospect for its application in synthetic vaccine, hydrogel and bacterial nanobiological reactor is further discussed.
Cyclization ; Lysine ; Peptides ; chemistry ; Proteins