Activation of TGR5 reduces high glucose-induced cardiomyocyte hyper-trophy by inhibiting CaN/NFAT3 signaling / 中国病理生理杂志

AIM: To investigate the role of G-protein-coupled bile acid receptor 1 ( GPBR1; also known as TGR5) activation in high glucose-induced cardiomyocyte hypertrophy and calcineurin (CaN)/nuclear factor of activated T-cells 3 (NFAT3) signaling.METHODS:Primarily cultured mouse cardiomyocytes were used in the study .The cell surface areas of the cardiomyocytes were measured by an image analysis system .The cell protein content was detected by BCA meth-od.The expression of TGR5, CaN and NFAT3 at mRNA and protein levels was determined by RT-PCR and Western blot . RESULTS:The mouse cardiomyocytes were successfully cultured .High glucose significantly induced the increases in the cell surface area, the cell protein content and the expression of CaN and NFAT 3 (P<0.05) in the cardiomyocytes.TGR5 activation or a CaN antagonist cyclosporin A inhibited high glucose-induced cardiomyocyte hypertrophy and the expression of CaN and NFAT3 (P<0.05).These effects of TGR5 activation were abolished by TGR5 gene interference (P<0.05). CONCLUSION:TGR5 activation reduces high glucose-induced cardiomyocyte hypertrophy by inhibiting CaN /NFAT3 sig-naling.

High glucose induces H9 c2 cardiomyocyte hypertrophy through Ca2+-CaN-NFAT3 signaling pathway / 中国病理生理杂志

AIM:To study the morphological changes of cardiac H9c2 cells during the developmental process of fetal rat.METHODS:Embryonic rat heart-derived H9c2 cells were maintained in DMEM supplemented with 10%fetal bovine serum.The H9c2 cells were plated at a density of 6 000 cells/cm and divided into 5 groups:H9c2 cells were trea-ted with 5 mmol/L glucose, 25 mmol/L glucose, 50 mmol/L glucose, Norvasc (25 nmol/L) +25 mmol/L glucose, or Norvasc (25 nmol/L)+50 mmol/L glucose for 48 h.The morphology of H9c2 cells was observed.The cell surface area was measured by Image-Pro Plus 6.1 software.Fluorescence spectrophotometry was used to detect the concentration of in-tracellular calcium ion ( [ Ca2+] i ) in the cardiomyocytes.The concentration of CaN in the cell was measured by ELISA. The mRNA expression of CaNAβ, NFAT3 and β-MHC in the cells was detected by real-time PCR.The protein levels of CaNAβ, NFAT3 and β-MHC in cultural H9c2 cells were detected by Western blot.RESULTS: The mean area of the cells, the mean fluorescence value of [ Ca2+] i and the concentration of CaN in 25 mmol/L glucose group were higher than those in 5 mmol/L glucose group, and those were lower than those in 50 mmol/L glucose group.After treated with Nor-vasc, those results decreased significantly.The expression of CaNAβ, NFAT3 andβ-MHC at mRNA and protein levels in 25 mmol/L glucose group was higher than those in 5 mmol/L glucose group, but was lower than those in 50 mmol/L glu-cose group .The expression of CaNAβ, NFAT3 andβ-MHC at mRNA and protein levels decreased significantly in Norvasc treatment group.CONCLUSION:Ca2+-CaN-NFAT3 signaling pathway is perhaps involved in high glucose-induced H9c2 cardiomyocyte hypertrophy.