Effects of high glucose on expression of OPG and RANKL in rat aortic vascular smooth muscle cells

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.

Effects of high glucose on expression of OPG and RANKL in rat aortic vascular smooth muscle cells

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.

p42/p44 mitogen-activated protein kinases inhibit atrial natriuretic peptide mRNA transcription in gp130-mediated hypertrophic ventricular myocytes

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.

Construction and characterization of a full-lengh cDNA library from non-fresh Giardia lamblia

OBJECTIVE@#To construct rapidly a full-length cDNA library from nanogram amounts total RNA of Giardia lamblia (G. lamblia) trophozoites stocked in RNA stabilization reagent.@*METHODS@#Total RNA of Giardia was extracted using Trizol reagent. A full-length cDNA library of G. lamblia trophozoites was constructed by a long-distance PCR (LD-PCR) method. The recombinant rate and the coverage rate of full-length clones of the library were evaluated. The inserted fragments were identified and sequenced by PCR amplification.@*RESULTS@#The titer of cDNA library was 3.85 × 10(7) pfu/mL. The length of inserted fragments ranged from 0.4 to 2.5 kb, and the recombination efficiency accounted for 100% (20/20). The coverage rate of full-length clones is high (17/20).@*CONCLUSIONS@#The RNA stabilization reagent may be used to fix the cells and prevent the RNA in cells even though delivered under normal atmospheric temperature. The long-distance PCR can be used to construct a full-length cDNA library rapidly and it needs less RNA than the traditional method from mRNA.

Inhibition of Pim-1 attenuates the proliferation and migration in nasopharyngeal carcinoma cells

OBJECTIVE@#To explore the role of proto-oncogene Pim-1 in the proliferation and migration of nasopharyngeal carcinoma (NPC) cells.@*METHODS@#Pim-1 expressions in NPC cell lines CNE1, CNE1-GL, CNE-2Z and C666-1 were examined by RT-PCR, western blotting and immunoflucesence, respectively. After CNE1, CNE1-GL and C666-1 cells were treated with different concentrations of Pim-1 special inhibitor, quercetagetin, the cell viability, colony formation rate and migration ability were analyzed.@*RESULTS@#Pim-1 expression was negative in well-differentiated CNE1 cells, whereas expressed weakly positive in poor-differentiated CNE-2Z cells and strongly positive in undifferentiated C666-1 cells. Interestingly, CNE1-GL cells that derived from CNE1 transfected with an Epstein Barr virus latent membrane protein-1 over-expression plasmid displayed stronger expression of Pim-1. Treatment of CNE1-GL and C666-1 cells with quercetagetin significantly decreased the cell viability, colony formation rate and migration ability but not the CNE1 cells.@*CONCLUSIONS@#These findings suggest that Pim-1 overexpression contributes to NPC proliferation and migration, and targeting Pim-1 may be a potential treatment for anti-Pim-1-expressed NPCs.