title: Phycocyanin may suppress D-galactose-induced human lens epithelial cell apoptosis through mitochondrial and unfolded protein response pathways.
abstract: Apoptosis of lens epithelial cell (LEC) plays an important role in cataract formation, and its prevention may be one of the therapeutic strategies in treating cataract. This study used human lens epithelial cell (hLEC) line SRA01/04 to investigate the protective effect and mechanism of phycocyanin on glactose-induced apoptosis in hLEC. hLECs were cultured in D/F(12)-10% FBS medium containing 125mM d-galactose with or without phycocyanin. Cell viability was assessed by methylthiazol tetrazolium (MTT) assay. Cell apoptosis was elevated with Wright-Giemsa staining, AO/EB double staining, and DNA fragmentation assay. Mitochondrial apoptosis-associated molecules and unfolded protein response-associated molecules from cultured SRA01/04 cells were quantified using protein blot analysis. The results demonstrated that phycocyanin suppressed SRA01/04 cells' morphologic changes and apoptosis induced by d-galactose, inhibited the expression and activation of caspase 3, alternated the Bax/Bcl-2 ratio, and down-regulated the level of p53, GRP78, and CHOP in d-galactose-treated SRA01/04 cells. These results suggest that phycocyanin might suppress d-galactose-induced hLEC apoptosis through two pathways: mitochondrial pathway, involving p53 and Bcl-2 family protein expression, and unfolded protein response pathway, involving GRP78 and CHOP expression.
authors.affiliation: School of Life Science and Technology, China Pharmaceutical University, Nanjing, China. ouyu2008@126.com
authors.forename: Yu
authors.initials: Y
authors.lastname: Ou
authors.forename: Zhijun
authors.initials: Z
authors.lastname: Yuan
authors.forename: Kepeng
authors.initials: K
authors.lastname: Li
authors.forename: Xuegan
authors.initials: X
authors.lastname: Yang
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism; D015153:Blotting, Western; D053148:Caspase 3 / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D053938:DNA Fragmentation / Q000187:drug effects; D000091342:Endoplasmic Reticulum Chaperone BiP; D004789:Enzyme Activation / Q000187:drug effects; D004847:Epithelial Cells / Q000187:drug effects* / Q000648:ultrastructure; D005690:Galactose / Q000037:antagonists & inhibitors* / Q000633:toxicity*; D006801:Humans; D007908:Lens, Crystalline / Q000166:cytology* / Q000187:drug effects; D008856:Microscopy, Fluorescence; D008928:Mitochondria / Q000187:drug effects*; D010798:Phycocyanin / Q000494:pharmacology*; D013778:Tetrazolium Salts; D013844:Thiazoles; D056811:Unfolded Protein Response / Q000187:drug effects*
chemical_list: D051017:Apoptosis Regulatory Proteins; D000091342:Endoplasmic Reticulum Chaperone BiP; C000717247:HSPA5 protein, human; D013778:Tetrazolium Salts; D013844:Thiazoles; D010798:Phycocyanin; D053148:Caspase 3; C022616:thiazolyl blue; D005690:Galactose