The mechanisms involved in angiotensin II type 1 receptor (AT1-R) trafficking and membrane localization are largely unknown. In this study, we examined the role of caveolin in these processes. Electron microscopy of plasma membrane sheets shows that the AT1-R is not concentrated in caveolae but is clustered in cholesterol-independent microdomains; upon activation, it partially redistributes to ...

BACKGROUND An interaction of insulin with angiotensin II effects could be pathophysiologically important for the pathogenesis of atherosclerosis and hypertension. METHODS AND RESULTS We examined the effect of insulin on AT1 receptor gene expression in cultured vascular smooth muscle cells (VSMCs). A 24-hour incubation with insulin (100 nmol/L) produced a 2-fold increase in AT1 receptor densit...

Agonistic autoantibodies to the angiotensin II type I receptor (AT1-AA) and endothelin -1 (ET-1) are suggested to be important links between placental ischemia and hypertension during preeclampsia. Activation of the angiotensin II type 1 receptor (AT1R) increases endothelial cell production of ET-1; however, the importance of ET-1 in response to AT1-AA-mediated AT1 R activation during preeclamp...

The current study was to prepare a mouse-derived antibody against the angiotensin II type 1 receptor (AT1-mAb) based on monoclonal antibody technology, to provide a foundation for research on AT1-AA-positive diseases. Balb/C mice were actively immunized with the second extracellular loop of the angiotensin II type 1 receptor (AT1R-ECII). Then, mouse spleen lymphocytes were fused with myeloma ce...

BACKGROUND The AT1 receptor has been implicated in the pathogenesis of hypertension and atherosclerosis. Estrogen deficiency is also associated with cardiovascular diseases. Therefore, we examined the AT1 receptor gene expression in ovariectomized rats with and without estrogen replacement therapy and the influence of estrogen on AT1 receptor expression in cultured vascular smooth muscle cells....

Preeclampsia is a serious pathologic complication during pregnancy, and its pathogenesis remains poorly understood. Recent studies have demonstrated that autoantibodies against angiotensin II type 1A receptor (AT1-AA) are present in women with preeclampsia. However, their role in the development of hypertension in preeclamptic patients has never been previously investigated. The present study w...

Despite a presumptive role for type I (AT1) cells in alveolar epithelial transport, specific Na transporters have not previously been localized to these cells. To evaluate expression of Na transporters in AT1 cells, double labeling immunofluorescence microscopy was utilized in whole lung and in cytocentrifuged preparations of partially purified alveolar epithelial cells (AEC). Expression of Na ...

Many G protein-coupled receptors form dimers in cells. However, underlying mechanisms are barely understood. We report here that intracellular factor XIIIA transglutaminase crosslinks agonist-induced AT1 receptor homodimers via glutamine315 in the carboxyl-terminal tail of the AT1 receptor. The crosslinked dimers displayed enhanced signaling and desensitization in vitro and in vivo. Inhibition ...

signaling pathways. Sera of 30 pregnant patients, 16 diagnosed with severe preeclampsia and 14 normotensive, were examined for the presence of IgG capable of stimulating intracellular Ca mobilization. IgG from all preeclamptic patients activated AT1 receptors and increased intracellular free calcium. In contrast, none of the normotensive individuals had IgG capable of activating AT1 receptors. ...

Although processes involved in mRNA degradation play a significant role in dictating steady state mRNA levels, the influence of cell surface signaling on mRNA stability control is understood incompletely. In this study, the effects of cAMP-elevating agents on type I angiotensin II receptor (AT1-R) mRNA levels were assessed in cultured rat aortic vascular smooth muscle cells (VSMCs). AT1-R mRNA ...