Mitochondrial dynamics plays a critical role in maintaining healthy endothelial function, but whether the atherogenic advanced glycation end products (AGEs) can influence mitochondrial dynamics of endothelial cell remains unclear. AGE modified bovine serum albumin (AGE-BSA) was used as AGEs, primary human aortic endothelial cell line was multiplied, and divided into groups incubated with AGEs of different concentrations for different time. The expression of phosphatase and tensin homologue (PTEN)-induced putative kinase 1 (PINK1) was silenced with specific siRNA. Mitochondrial morphology of HAECs in each group was determined with transmission electron microscopy. Real time PCR method was used to detect the mRNA expression levels of mitochondrial dynamics regulatory genes mitofusin 1 (Mfn1), mitofusin 2 (Mfn2), optic atrophy 1 (Opa1), and dynamin-related protein 1 (Drp1) of HAECs, and western blot method was used to detect the protein expression levels of these regulatory genes. Specific antibody was used to block receptor for advanced glycation end products (RAGE). Treatment of different concentrations of AGEs, HAECs presented more granular mitochondrion, indicating AGEs promoted mitochondrial fission of HAECs remarkably. Silencing PINK1 induced mitochondrial fission in HAECs, and AGEs further promoted mitochondrial fragmentation in HAECs of PINK1 silenced. Different concentrations of AGEs down-regulated the mRNA and protein expression of mitochondrial pro-fusional genes Mfn1, Mfn2, Opa1, up-regulated the expression of mitochondrial pro-fissional gene Drp1, and both of the two phosphorylated Drp1 (p-ser-Drp1-616 and p-ser-Drp1-637) were increased. Time-dependent dynamic alterations of the expression levels of Mfn1, Mfn2, Opa1, and Drp1 were also found in HAECs stimulated with AGEs. Blocking RAGE with anti-RAGE inhibited AGEs induced mitochondrial fission and reversed AGEs induced expression changes of mitochondrial regulatory genes Drp1, Mfn1, Mfn2, and Opa1, indicating AGEs induced mitochondrial fission through RAGE in HAECs. In conclusion, AGEs may promote mitochondrial fission of HAECs through its receptor RAGE, silencing PINK1 induces mitochondrial fission, and AGEs further promote mitochondrial fragmentation in HAECs of PINK1 silenced. AGEs up-regulate the expression of mitochondrial pro-fissional gene Drp1 and down-regulate the expression of mitochondrial pro-fusional genes Mfn1, Mfn2, and Opa1 in HAECs.
Keywords: Advanced glycation end products; fission; fusion; gene expression; human aortic endothelial cells; mitochondrial dynamics; mitophagy; receptor for advanced glycation end products.
IJCEP Copyright © 2017.