Synergistic effect of deficiency in thrombosis-related genes / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the interaction of deficiency in thrombosis-related gene in a mouse model.</p><p><b>METHODS</b>To generate mice carrying mutations in alpha-galactosidase A (Gla) and factor V Leiden (Fvl) and analyze the phenotypes, namely, tissue fibrin deposition and thrombus formation in organs.</p><p><b>RESULTS</b>Fibrin deposition in organs of mice carrying both mutations in Gla and Fvl was significantly increased compared with that in mice with single mutaton: [Gla(-/0) Fv(Q/Q)+Gla(-/-)Fv(Q/Q)] vs.[Gla(-/0)Fv(+/+)]=(0.28+/-0.03)% vs.(0.07+/-0.007)%, P<0.01; [Gla(-/0)Fv(Q/Q)+Gla(-/-)Fv(Q/Q)] vs.[Gla(+/0)Fv(Q/Q)+Gla(+/+)Fv(Q/Q)]=(0.28+/-0.03)% vs.(0.11+/-0.02)%, P< 0.01. Meanwhile, the number of thrombi on organ sections of mice carrying both mutations in Gla and Fvl was significantly increased compared with the single mutation carrier: [Gla(-/0)Fv(Q/Q)+Gla(-/-)Fv(Q/Q)] vs.[Gla(-/0)Fv(+/+)]=1.9+/-0.7 vs. 0.0+/-0.0, P<0.05; [Gla(-/0)Fv(Q/Q)+Gla(-/-)Fv(Q/Q)] vs. [Gla(+/0)Fv(Q/Q)+Gla(+/+)Fv(Q/Q)]=1.9+/-0.7 vs. 0.3+/-0.1, P<0.05.</p><p><b>CONCLUSION</b>These observations demonstrated that there was synergistic effect in Gla and Fvl deficiency in mice. It suggested that there could be a combination of GLA deficiency and FVL or other thrombosis-related gene defect in patients with genetic severe early-onset thrombosis.</p>

Leptin promotes neointimal formation by stimulating vascular smooth muscle cell proliferation through leptin receptor / 中华心血管病杂志

<p><b>OBJECTIVE</b>To evaluate the role of leptin in neointimal formation and related mechanisms.</p><p><b>METHODS</b>Femoral arterial injury was induced in wild-type (Wt, n = 10), leptin-deficient (Lep(-)/-, n = 12), and leptin receptor-deficient (LepR(-)/-, n = 10) mice. Leptin treatment studies (tail vein injection of adenovirus expressing murine leptin on the RSV promoter, ad-leptin) were performed on Lep(-)/- (n = 5) and LepR(-)/- (n = 4) mice. Intimal (I) and medial (M) areas were measured and the ratio of I/M was calculated. Smooth muscle cells were detected by smooth muscle alpha-actin staining using an alpha-actin monoclonal antibody. Cellular proliferation was analyzed with BrdU Staining Kit and the number of BrdU-positive cells was counted manually. Plasma leptin level was measured by ELISA.</p><p><b>RESULTS</b>The I/M ratio of Lep(-)/- and LepR(-)/- mice was significantly lower than that in Wt separately (Lep(-)/- vs. Wt = 0.80 +/- 0.14 vs. 1.50 +/- 0.22, P < 0.01; LepR(-)/- vs. Wt = 0.55 +/- 0.20 vs. 1.50 +/- 0.22, P < 0.05). Plasma leptin level was significantly increased in Lep(-)/- and LepR(-)/- mice post leptin treatment. I/M was significantly increased in Lep(-)/- mice receiving ad-leptin compared with untreated Lep(-)/- mice (P < 0.05), while I/M was similar between LepR(-)/- mice with and without ad-leptin treatment (P > 0.05). The changes on number of positive alpha-actin and BrdU stained smooth muscle cells were consistent with the neointimal formation findings in various groups.</p><p><b>CONCLUSIONS</b>Mice lacking leptin or the leptin receptor were protected from neointimal formation following vascular injury. Leptin treatment increased neointimal formation in Lep(-)/- but not in LepR(-)/- mice, suggesting leptin receptor activation and vascular smooth muscle cell proliferation played a pivotal role on neointimal formation post-injury in this model, giving an evidence that high plasma leptin level is a risk factor for neointimal formation.</p>

Impact of fenofibrate on NO and endothelial VCAM-1 expression in hyperlipidemic rats / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the mechanism of hyperlipidemia- and imflammation-induced functional impairment of the endothelium.</p><p><b>METHODS</b>The experiment was conducted using 3 groups of rats fed for 20 weeks with standard chow (control group), high-fat diet and high-fat diet with daily fenofibrate treatment (10 mg/kg, starting since the fifth week), respectively. After 4 and 20 weeks of feeding, respectively, serum lipid level and NO concentration were measured in the rats, and the epithelial vascular cell adhesion molecule-1 (VCAM-1) expression and cell adhesiveness to the aortic endothelium were observed.</p><p><b>RESULTS</b>Compared with the control group, the rats with hyperlipidemia induced by long-term high-fat diet feeding showed lower NO concentration and increased leukocyte accumulation on the endothelial surface, exhibiting also stronger and more extensive endothelial expression of VCAM-1. In contrast, the hyperlipidemic rats with fenofibrate treatment shoed significantly decreased VCAM-1 expression and leukocyte adhesion with recovery of the NO level.</p><p><b>CONCLUSION</b>NO deficiency and activation of inflammation are involved in vascular impairment in rats with high-fat diet-induced hyperlipidemia, and fenofibrate can effectively prevent atherosclerosis by restoring NO concentration and down-regulating VCAM-1 expression in these rats.</p>

The effect and mechanism of felodipine and valsartan on a novel salt-sensitive hypertensive rat induced by sensory denervation / 中华心血管病杂志

<p><b>OBJECTIVE</b>To investigate the effect and mechanism of valsartan and felodipine extended release tablets (Plendil) on a novel salt-sensitive hypertensive rat induced by sensory denervation.</p><p><b>METHODS</b>Newborn Wistar rats were given 50 mg/kg capsaicin subcutaneously on the 1st and 2nd day of life. Control rats were treated with vehicle solution (10%ethanol, 10%Tween 80 in saline). After weanling period (3 weeks), male rats were divided into 5 groups and subject to the following treatment for 4 weeks: control + high salt diet (4%, CON-HS), capsaicin + normal salt diet (0.5%, CAP-NS), capsaicin + high salt diet (CAP-HS), capsaicin + high salt diet + Valsartan (30 mg/kg per day, by orally) (CAP-HS-VAL), capsaicin + high salt diet + Plendil (30 mg/kg per day, by orally) (CAP-HS-PLE). Tail-cuff systolic blood pressure, body weight, intralymphocytic [Ca(2+)](i), plasma calcitonin gene-related peptide concentration ([CGRP]), angiotensin II concentration ([AngII]) and 24 hour water intake, urinary volume, urinary Na(+) and K(+) concentrations were examined.</p><p><b>RESULTS</b>Tail-cuff systolic blood pressure and intralymphocytic [Ca(2+)](i) were lower in CAP-HS-VAL or CAP-HS-PLE group than those in CAP-HS group. Plasma [AngII] were higher in CAP-HS-VAL group than that in other groups. Tail-cuff systolic blood pressure were lower in CAP-HS-VAL group than that in CAP-HS-PLE group. Intralymphocytic [Ca(2+)](i) were lower in CAP-HS-PLE group than that in CAP-HS-VAL group. The 24 hour urine sodium excretion was higher in CAP-HS-PLE group than that in CAP-HS or CAP-HS-VAL group.</p><p><b>CONCLUSION</b>Valsartan or Plendil could prevent the development of salt-sensitive hypertension induced by sensory denervation and the overloading of intracellular [Ca(2+)](i), which indicated that salt-sensitive hypertension induced by sensory nerve degeneration might be related to renin-angiotensin-aldosterone system (RAAS) and the over loading intracellular [Ca(2+)](i), and might be more closely to RAAS.</p>