RESUMO
AIMS: A soluble form of endoglin (sEng) was proposed to participate in the induction of endothelial dysfunction in small blood vessels. Here, we tested the hypothesis that high levels of sEng combined with a high-fat diet induce endothelial dysfunction in an atherosclerosis-prone aorta. METHODS AND RESULTS: Six-month-old female and male transgenic mice overexpressing human sEng (Sol-Eng+) with low (Sol-Eng+low) or high (Sol-Eng+high) levels of plasma sEng were fed a high-fat rodent diet containing 1.25% cholesterol and 40% fat for 3 months. The plasma cholesterol and mouse sEng levels did not differ in the Sol-Eng+high and Sol-Eng+low mice. The expression of proinflammatory (P-selectin, ICAM-1, pNFκB and COX-2) and oxidative-stress-related markers (HO-1, NOX-1 and NOX-2) in the aortas of Sol-Eng+high female mice was significantly higher than in Sol-Eng+low female mice. Endothelium-dependent vasodilatation induced by acetylcholine was preserved better in the Sol-Eng+ high female mice than in the Sol-Eng+low female mice. CONCLUSION: These results suggest that high concentrations of sEng in plasma in combination with a high-fat diet induce the simultaneous activation of proinflammatory, pro-oxidative and vasoprotective mechanisms in mice aorta and the balance of these biological processes determines whether the final endothelial phenotype is adaptive or maladaptive.
Assuntos
Aorta/metabolismo , Doenças da Aorta/metabolismo , Aterosclerose/metabolismo , Dieta Hiperlipídica , Endoglina/metabolismo , Inflamação/metabolismo , Óxido Nítrico/metabolismo , Estresse Oxidativo , Vasodilatação , Adaptação Fisiológica , Animais , Aorta/efeitos dos fármacos , Aorta/fisiopatologia , Doenças da Aorta/sangue , Doenças da Aorta/genética , Doenças da Aorta/fisiopatologia , Aterosclerose/sangue , Aterosclerose/genética , Aterosclerose/fisiopatologia , Biomarcadores/metabolismo , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Endoglina/sangue , Endoglina/genética , Feminino , Predisposição Genética para Doença , Humanos , Inflamação/sangue , Inflamação/genética , Inflamação/fisiopatologia , Mediadores da Inflamação/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CBA , Camundongos Transgênicos , Fenótipo , Regulação para Cima , Vasodilatação/efeitos dos fármacos , Vasodilatadores/farmacologiaRESUMO
Increased levels of a soluble form of endoglin (sEng) circulating in plasma have been detected in various pathological conditions related to cardiovascular system. High concentration of sEng was also proposed to contribute to the development of endothelial dysfunction, but there is no direct evidence to support this hypothesis. Therefore, in the present work we analyzed whether high sEng levels induce endothelial dysfunction in aorta by using transgenic mice with high expression of human sEng. Transgenic mice with high expression of human sEng on CBAxC57Bl/6J background (Sol-Eng+) and age-matched transgenic littermates that do not develop high levels of human soluble endoglin (control animals in this study) on chow diet were used. As expected, male and female Sol-Eng+ transgenic mice showed higher levels of plasma concentrations of human sEng as well as increased blood arterial pressure, as compared to control animals. Functional analysis either in vivo or ex vivo in isolated aorta demonstrated that the endothelium-dependent vascular function was similar in Sol-Eng+ and control mice. In addition, Western blot analysis showed no differences between Sol-Eng+ and control mice in the protein expression levels of endoglin, endothelial NO-synthase (eNOS) and pro-inflammatory ICAM-1 and VCAM-1 from aorta. Our results demonstrate that high levels of soluble endoglin alone do not induce endothelial dysfunction in Sol-Eng+ mice. However, these data do not rule out the possibility that soluble endoglin might contribute to alteration of endothelial function in combination with other risk factors related to cardiovascular disorders.
