Targeted Genomic Disruption of H-Ras Induces Hypotension Through a NO-cGMP-PKG Pathway–Dependent Mechanism

Abstract

Abstract-The aim of the present experiments was to evaluate the differences in arterial pressure between H-Ras lacking mice and control mice and to analyze the mechanisms involved in the genesis of the differences. H-Ras lacking mice and mouse embryonic fibroblasts from these animals were used. Blood pressure was measured using 3 different methods: direct intraarterial measurement in anesthetized animals, tail-cuff sphygmomanometer, and radiotelemetry. H-Ras lacking mice showed lower blood pressure than control animals. Moreover, the aorta protein content of endothelial nitric oxide synthase, soluble guanylyl cyclase, and cyclic guanosine monophosphate-dependent protein kinase was higher in H-Ras knockout mice than in control animals. The activity of these enzymes was increased, because urinary nitrite excretion, sodium nitroprusside-stimulated vascular cyclic guanosine monophosphate synthesis, and phosphorylated vasoactive-stimulated phosphoprotein in aortic tissue increased in these animals. Furthermore, mouse embryonic fibroblasts from H-Ras lacking mice showed higher cyclic guanosine monophosphate-dependent protein kinase promoter activity than control cells. These results strongly support the upregulation of the nitric oxide-cyclic guanosine monophosphate pathway in H-Ras-deficient mice. Moreover, they suggest that H-Ras pathway could be considered as a therapeutic target for hypertension treatment. (Hypertension. 2010;56:484-489.)

H‐ ras deletion protects against angiotensin II–induced arterial hypertension and cardiac remodeling through protein kinase G‐Iβ pathway activation

“…As previously described (17), H‐ ras –/– mice had lower systolic, diastolic, and mean arterial pressure than did H‐ ras +/+ mice under basal conditions ( Table 1 ). Long‐term AngII infusion significantly increased arterial blood pressure in both strains of animals, but the increase in mean arterial pressure in H ‐ras +/+ mice (30 ± 3 mmHg) was greater than the increase in H‐ ras –/– mice (16 ± 3mmHg; P < 0.05; Table 1).…”

“…Blood pressure was considered as the mean of at least 20 consecutive valid measurements. All mice were trained with the tail‐cuff system (17).…”

“…Tissues or cells were lysed in 50 mM Trizma (pH 8), 150 mM NaCl, 0.1% Triton X‐100, 10 mM EDTA, 0.25% sodium deoxycholate, and protease inhibitors. Protein samples were run on SDS‐PAGE gels and transferred to PVDF membranes (17). After blocking, immunodetection was performed with the following Abs: anti‐PKG‐Iβ (Stressgene, ADI‐KAP‐PK002, RRID:AB_2039484; Enzo Life Sciences, Victoria, BC, Canada) (27); PKG‐Iα, p‐ERK, ERK, p‐glycogen synthase kinase‐3β(Ser9) [GSK‐3β(Ser9)], GSK‐3β, p‐CREB(Ser129), p‐CREB (Ser133), and CREB (Cell Signaling Technology, Danvers, MA, USA); phosphorylated (p) vasodilator‐stimulated phosphoprotein(Ser239) [p‐VASP (Ser239)] and VASP (Cal‐biochem, La Jolla, CA, USA); and TGF‐β1, fibronectin, and collagen type I (Abcam, Cambridge, United Kingdom), followed by horseradish peroxidase‐conjugated secondary antibodies.…”

CYP 2J2 and its metabolites (epoxyeicosatrienoic acids) attenuate cardiac hypertrophy by activating AMPK α2 and enhancing nuclear translocation of Akt1

“…After 14 days, mice were subjected to transthoracic echocardiography and cardiac catheterization to determine cardiac function. Blood pressure was measured by tail‐cuff as described previously (Chamorro‐Jorganes et al ., 2010). Animals were habituated to the blood pressure apparatus for several days before the data were collected.…”

“…After 14 days, mice were subjected to cardiac catheterization to determine cardiac function. Blood pressure was measured by tail‐cuff as described previously (Chamorro‐Jorganes et al ., 2010). …”