Fig. 4.

PDZ domain-containing 8 (PDZD8) knockdown inhibits palmitic acid (PA)-induced mitochondrial dysfunction and endoplasmic reticulum (ER) stress in insulin 1 (INS-1) cells. (A, B) The mitochondrial membrane potential was detected using JC-1 probe. Green fluorescence indicates low mitochondrial membrane potential and red fluorescence indicates high mitochondrial membrane potential. (C) Insulin secretion was detected by enzyme-linked immunosorbent assay (ELISA) induced by 16.7 mM glucose as glucose-stimulated insulin secretion. (D) The copy fold of mitochondrial DNA (mtDNA). (E) The expression of ER stress-related proteins was detected by Western blotting. siPDZD8, siRNA PDZ domain-containing 8; p-PERK, phosphorylated protein kinase R (PKR)-like endoplasmic reticulum kinase; p-eIF2α, phosphorylated eukaryotic translation initiation factor 2A; ATF4, activating transcription factor 4; CHOP, C/EBP-homologous protein; GAPDH, glyceraldehyde 3-phosphate dehydrogenase. ^aP<0.05 vs. control (Con) group, ^bP<0.05 vs. PA+shRNA negative control (shNC) group.