TY - JOUR AU - YOU Wen-ting AU - ZHOU Tao AU - MA Zeng-chun AU - LIANG Qian-de AU - XIAO Cheng-rong AU - TANG Xiang-lin AU - TAN Hong-ling AU - ZHANG Bo-li AU - WANG Yu-guang AU - GAO Yue PY - 2017 TI - Ophiopogonin D maintains Ca 2+ homeostasis in rat cardiomyocytes in vitro by upregulating CYP2J3/ EETs and suppressing ER stress JF - Acta Pharmacologica Sinica; Vol 37, No 3 (March 2016): Acta Pharmacologica Sinica Y2 - 2017 KW - N2 - Aim: CYP2J3 in myocardium metabolizes arachidonic acid to 4 regioisomeric epoxyeicosatrienoic acids (EETs), which have diverse biological activities in rat heart. In this study we examined whether CYP2J3 was involved in cardioprotective effects of ophiopogonin D (OPD), a steroidal glycoside isolated from Chinese herb Radix ophiopogonis. Methods: Rat cardiomyoblast cell line (H9c2 cells) was tested. Intracellular Ca 2+ concentrations ([Ca 2+ ] i ) were measured using Fluo-4/AM. The expression of calcium-regulating molecules and ER stress signaling molecules was measured with qRT-PCR and Western blot analyses. Cell apoptosis was quantified with Hoechst 33258 staining and TUNEL assay. The level of 14,15-DHET, a stable metabolite of 14,15-EET, was assessed with ELISA. Results: Angiotensin II (10 -6 mol/L) significantly decreased the expression of calcium-regulating molecules (SERCA2a, PLB, RyR2 and FKBP12.6), and elevated [Ca 2+ ] i in H9c2 cells. Furthermore, angiotensin II markedly increased the expression of ER stress signaling molecules (GRP78, CHOP, p-JNK and cleaved caspase-12) and ER stress-mediated apoptosis. OPD (100, 250 and 500 nmol/L) dose-dependently increased CYP2J3 expression and 14,15-DHET levels in normal H9c2 cells. Pretreatment of H9c2 cells with OPD suppressed angiotensin II-induced abnormalities in Ca 2+ homeostasis, ER stress responses and apoptosis. Overexpression of CYP2J3 or addition of exogenous 14,15-EET also prevented angiotensin II-induced abnormalities in Ca 2+ homeostasis, whereas transfection with CYP2J3 siRNA diminished the effects of OPD on Ca 2+ homeostasis. Furthermore, the intracellular Ca 2+ chelator BAPTA suppressed angiotensin II-induced ER stress responses and apoptosis in H9c2 cells. Conclusion: OPD is a novel CYP2J3 inducer that may offer a therapeutic benefit in treatment of cardiovascular diseases related to disturbance of Ca 2+ homeostasis and ER stress. UR - http://www.chinaphar.com/article/view/9444