Antiatherosclerotic therapy using cell differentiation-promoting effect of biologically active peptides

我们首先检测了小鼠股动脉损伤中利钠肽（ANP， BNP， CNP）受体的表达。在丝损伤3周后的新生内膜中均有明显的ANP和BNP受体GC-A和CNP受体GC-B的表达，且GC-A的表达水平高于GC-B。对比野生型和GC-A敲除小鼠丝损伤诱导的新生内膜形成程度，GC-A敲除小鼠新生内膜面积更大。提示心脏释放的内源性ANP和BNP可能抑制股动脉铁丝损伤后动脉粥样硬化的改变。为了进一步研究内源性ANP和BNP在动脉粥样硬化病变中观察到的新生血管中的作用，我们在野生型和GC-A敲除小鼠中建立了下肢缺血模型，并评估血流恢复情况。野生型小鼠血流量在3周后恢复到70%左右。更有趣的是，GC-A基因敲除小鼠的血流恢复率约为20%，其中约一半的小鼠下肢坏死。提示内源性ANP和BNP可能在缺血性病变血管生成中起重要作用。基于这些结果，我们设计了一项体外研究，以研究ANP和BNP是否刺激来源于人血单核细胞的血管内皮祖细胞中的环GMP（cGMP）积累。结果，ANP和BNP刺激后细胞内cGMP水平显著升高，表明这些肽对内皮祖细胞有直接影响。我们的研究结果表明，内源性ANP和BNP不仅参与抑制动脉粥样硬化病变的形成，而且还参与促进这些病变中的新血管形成。因此，本研究为利用ANP和BNP促进细胞分化的作用进行抗动脉粥样硬化治疗的临床应用提供了很大的进展。我们将进一步研究CNP、肾上腺髓质素和胃饥饿素的抗动脉粥样硬化作用和治疗应用。少

We first examined the expression of receptors for natriuretic peptides(ANP, BNP, CNP) in wire-injured femoral arteries in mice. Significant expressions of both GC-A(receptor for ANP and BNP) and GC-B(receptor for CNP) were found in neointima after 3 weeks of wire injury, and the expression level of GC-A was higher than that of GC-B. When the extent of wire injury-induced neointima formation was compared between wild-type and GC-A knockout mice, the area of neointima was greater in GC-A knockout mice. This result suggested the possibility that endogenous ANP and BNP released from the heart inhibited atherosclerotic change of femoral artery after wire injury. To further examine the role of endogenous ANP and BNP in neovascularization observed in atherosclerotic lesions, lower limb-ischemic model was made in both wild-type and GC-A knockout mice, and the recovery of blood flow was evaluated. The blood flow was restored to about 70% after 3 weeks in wild-type mice. On the other hand, inter … More estingly, the recovery rate of blood flow in GC-A knockout mice was about 20%, and approximately half of them had necrotized lower limbs. The finding suggested that endogenous ANP and BNP might play an important role in the angiogenesis in ischemic lesions. From these results, an in vitro study was designed to investigate whether ANP and BNP, stimulate cyclic GMP(cGMP) accumulation in vascular endothelial progenitor cells derived from human blood mononuclear cells. As a result, intracellular cGMP levels were remarkably elevated after stimulation with ANP and BNP, suggesting that these peptides have a direct effect on endothelial progenitor cells. Our findings indicate that endogenous ANP and BNP are involved not only in the inhibition of the formation of atherosclerotic lesions, but also in the promotion of neovascularization in those lesions. Thus, the present study provided a great progress forclinical application of antiatherosclerotic therapy using cell differentiation-promoting effect of ANP and BNP. We will forward further investigations about antiatherosclerotic effects and therapeutic application of CNP, adrenomedulin, and ghrelin. Less