title: The Chondroprotective Role of TMF in PGE2-Induced Apoptosis Associating with Endoplasmic Reticulum Stress.
abstract: Endoplasmic reticulum stress (ERS) has been demonstrated to exhibit a critical role in osteoarthritic chondrocytes. Whether 5,7,3',4'-tetramethoxyflavone (TMF) plays the chondroprotective role in inhibition of PGE2-induced chondrocytes apoptosis associating with ERS has not been reported. To investigate this, the activation of PERK, ATF6, and IRE1 signaling pathways in ERS in chondrocytes pretreated with PGE2 was studied. By treatment with PGE2, the chondrocytes apoptosis was significantly increased, the proapoptotic CHOP and JNK were upregulated, the prosurvival GRP78 and XBP1 were downregulated, and GSK-3β was also upregulated. However, TMF exhibited the effectively protective functions via counteracting these detrimental effects of PGE2. Finally, the inflammatory cytokine PGE2 can activate ERS signaling and promote chondrocytes apoptosis, which might be associated with upregulation of GSK-3β. TMF exhibits a chondroprotective role in inhibiting PGE2-induced ERS and GSK-3β.
authors.affiliation: Department of Clinical Research Center, The First Affiliated Hospital of Gannan Medical University, Ganzhou 341000, China.
authors.forename: Jianqiong
authors.initials: J
authors.lastname: Yang
authors.affiliation: College of Pharmacy, Gannan Medical University, Ganzhou 341000, China.
authors.forename: Haiqing
authors.initials: H
authors.lastname: Liu
authors.affiliation: College of Pharmacy, Gannan Medical University, Ganzhou 341000, China.
authors.forename: Linfu
authors.initials: L
authors.lastname: Li
authors.affiliation: College of Pharmacy, Gannan Medical University, Ganzhou 341000, China.
authors.forename: Hai
authors.initials: H
authors.lastname: Liu
authors.affiliation: College of Pharmacy, Gannan Medical University, Ganzhou 341000, China.
authors.forename: Weimei
authors.initials: W
authors.lastname: Shi
authors.affiliation: College of Pharmacy, Gannan Medical University, Ganzhou 341000, China.
authors.forename: Longhuo
authors.initials: L
authors.lastname: Wu