Rosuvastatin beneficially alters the glomerular structure of kidneys from spontaneously hypertensive rats (SHRs)

Beneficial effect of simvastatin on human umbilical vein endothelial cells gap junctions induced by TNF-α

Although simvastatin has been shown to inhibit vascular permeability, which might be amplified via gap junction intercellular communication (GJIC), the underlying mechanism of action remains unclear. In the present study, we investigated the effects and mechanisms of simvastatin on endothelial cells GJIC. Specifically, human umbilical vein endothelial cells (HUVECs) were stimulated with TNF-α (10 ng/mL) alone or in combination with simvastatin (5 µM), and their effects on vascular endothelial cell GJIC tested via the scrape loading/dye transfer (SL/DT) assay. Next, we performed immunofluorescence, real-time PCR and western blot assays to analyze expression of Cx37, Cx40 and Cx43 in HUVECs. Results showed that GJIC activity in HUVECs was markedly elevated in HUVECs treated with TNF-α in combination with simvastatin. In addition, simvastatin treatment significantly upregulated expression of Cx37 and Cx40 but downregulated Cx43 mRNAs and proteins. Taken together, these marked changes indicated that simvastatin exerts its regulatory effects on gap junction function by upregulating Cx37 and Cx40 and downregulating Cx43 expression.

Expression and redistribution of β-catenin in the cardiac myocytes of left ventricle of spontaneously hypertensive rat

Beta-catenin is not only an adhering junction protein, but also the central player of the canonical Wnt signalling pathway. In order to investigate the roles of β-catenin in the mechanism of myocardial hypertrophy, we determined the expression and distribution of β-catenin in the cardiomyocytes of spontaneously hypertensive heart failure (SHHF) rats and age-matched Wistar-Kyoto (WKY) rats. We identified the reducing of β-catenin expression in the membrane protein fraction but increasing in the nuclear protein in the 6 and 12 month-old SHHF rats as compared with the age-matched WKY rats by Western blotting. Immunolabeling of β-catenin colocalized with cadherin at the intercalated disc sites and showed nuclear accumulation in myocytes of SHHF rats. We also revealed that the association between glycogen synthase kinase-3β and β-catenin had weakened in the 6 month-old SHHF rats as compared with the age-matched WKY rats by immunoprecipitation. These findings suggested that nuclear translocation of β-catenin might play important roles in regulating signal transduction in the decompensated hypertrophy stage.