Huby Anne-Cécile, Otvos Laszlo, Belin de Chantemèle Eric J
From the Physiology Department, Medical College of Georgia at Georgia Regents University, Augusta (A.-C.H., E.J.B.d.C.); Biology Department, Temple University, Philadelphia, PA (L.O.); and Department of Medical Microbiology, Semmelweis University, Budapest, Hungary (L.O.).
Hypertension. 2016 May;67(5):1020-8. doi: 10.1161/HYPERTENSIONAHA.115.06642. Epub 2016 Mar 7.
Obesity is a major risk factor for cardiovascular disease in males and females. Whether obesity triggers cardiovascular disease via similar mechanisms in both the sexes is, however, unknown. In males, the adipokine leptin highly contributes to obesity-related cardiovascular disease by increasing sympathetic activity. Females secrete 3× to 4× more leptin than males, but do not exhibit high sympathetic tone with obesity. Nevertheless, females show inappropriately high aldosterone levels that positively correlate with adiposity and blood pressure (BP). We hypothesized that leptin induces hypertension and endothelial dysfunction via aldosterone-dependent mechanisms in females. Leptin control of the cardiovascular function was analyzed in female mice sensitized to leptin via the deletion of protein tyrosine phosphatase 1b (knockout) and in agouti yellow obese hyperleptinemic mice (Ay). Hypersensitivity to leptin (wild-type, 115 ± 2; protein tyrosine phosphatase 1b knockout, 124 ± 2 mm Hg; P<0.05) and obesity elevated BP (a/a, 113 ± 1; Ay, 128 ± 7 mm Hg; P<0.05) and impaired endothelial function. Chronic leptin receptor antagonism restored BP and endothelial function in protein tyrosine phosphatase 1b knockout and Ay mice. Hypersensitivity to leptin and obesity reduced BP response to ganglionic blockade in both strains and plasma catecholamine levels in protein tyrosine phosphatase 1b knockout mice. Hypersensitivity to leptin and obesity significantly increased plasma aldosterone levels and adrenal CYP11B2 expression. Chronic leptin receptor antagonism reduced aldosterone levels. Furthermore, chronic leptin and mineralocorticoid receptor blockade reduced BP and improved endothelial function in both leptin-sensitized and obese hyperleptinemic female mice. Together, these data demonstrate that leptin induces hypertension and endothelial dysfunction via aldosterone-dependent mechanisms in female mice and suggest that obesity leads to cardiovascular disease via sex-specific mechanisms.
肥胖是男性和女性心血管疾病的主要危险因素。然而,肥胖是否通过相同机制在两性中引发心血管疾病尚不清楚。在男性中,脂肪因子瘦素通过增加交感神经活动,在很大程度上导致了与肥胖相关的心血管疾病。女性分泌的瘦素比男性多3至4倍,但肥胖时却没有表现出高交感神经张力。尽管如此,女性的醛固酮水平却异常升高,且与肥胖和血压(BP)呈正相关。我们推测,瘦素通过醛固酮依赖机制在女性中诱发高血压和内皮功能障碍。通过敲除蛋白酪氨酸磷酸酶1b(基因敲除)使雌性小鼠对瘦素敏感,并在刺豚鼠黄色肥胖高瘦素血症小鼠(Ay)中分析瘦素对心血管功能的控制作用。对瘦素的超敏反应(野生型,115±2;蛋白酪氨酸磷酸酶1b基因敲除,124±2 mmHg;P<0.05)和肥胖会升高血压(a/a,113±1;Ay,128±7 mmHg;P<0.05)并损害内皮功能。长期使用瘦素受体拮抗剂可恢复蛋白酪氨酸磷酸酶1b基因敲除小鼠和Ay小鼠的血压及内皮功能。对瘦素的超敏反应和肥胖会降低两种品系小鼠对神经节阻断的血压反应以及蛋白酪氨酸磷酸酶1b基因敲除小鼠的血浆儿茶酚胺水平。对瘦素的超敏反应和肥胖会显著提高血浆醛固酮水平和肾上腺CYP11B2表达。长期使用瘦素受体拮抗剂可降低醛固酮水平。此外,长期使用瘦素和盐皮质激素受体拮抗剂可降低瘦素敏感型和肥胖高瘦素血症雌性小鼠的血压并改善内皮功能。总之,这些数据表明,瘦素通过醛固酮依赖机制在雌性小鼠中诱发高血压和内皮功能障碍,并提示肥胖通过性别特异性机制导致心血管疾病。