RESUMEN
OBJECTIVE: To explore effect of high glucose on expression of osteoprotegerin (OPG) and receptor activator of NF- κ B ligand (RANKE) in rat aortic vascular smooth muscle cells. METHODS: SD rats were intraperitoneally injected with streptozotocin, OPG and RANKL expression in rat thoracic aortas were detected by immunohistochemical staining. In cultured vascular smooth muscle cells (VSMCs) (A7r5), qRT-PCR and Western blot analysis were used to examine the mRNA and protein levels of OPG and RANKL. RESULTS: Our results demonstrated that OPG expression was increased in hyperglycemic rat aortic VSMCs, while RANKL expression was decreased. Besides, in vitro experiments high glucose induced OPG expression, but depressed RANKL expression by dose- and time-dependent manner in cultured A7r5. CONCLUSIONS: Our findings suggested that high glucose could promote the expression of OPG, and inhibit the expression of RANKL in VSMCs, which may be partly be the molecular mechanism of diabetic vascular calcification.
RESUMEN
OBJECTIVE: To understand the role of ANP mRNA transcription regulation in gp130-mediated cardiomyocyte hypertrophy, and the involved mitogen-activated protein kinase kinase (MEK)-extracellular signal-regulated kinase (ERK, also called p42/p44 MAPK) signaling pathway. METHODS: Isolated neonatal ventricular myocytes were treated with different concentrations of CT-1 (10(-9), 10(-8)and 10(-7)mol/L). MTT was used to analyze the viability and RT-PCR was used to detect ANP mRNA levels in cardiomyocyte. To inhibit p42/p44 MAPK activity in hypertrophic cardiomyocytes, the cells were pretreated with a specific MEK1 inhibitor. RESULTS: CT-1 significantly induced ANP mRNA expression and the viability of cardiomyocytes in a dose- and time-dependent manner. Furthermore, blocking p42/p44 MAPK activity by the special MEK1 inhibitor upregulated the ANP mRNA. CONCLUSIONS: p42/p44 MAPK have an important role in suppressing ANP mRNA transcription and cell activity in gp130-mediated hypertrophic ventricular myocytes.