Miao R Q, Murakami H, Song Q, Chao L, Chao J
Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425-2211, USA.
Circ Res. 2000 Mar 3;86(4):418-24. doi: 10.1161/01.res.86.4.418.
Kallistatin, a serine proteinase inhibitor (serpin), is expressed in the endothelial and smooth muscle cells of blood vessels. The potential function of kallistatin in vascular biology was investigated by studying its role in the proliferation and migration of cultured primary aortic vascular smooth muscle cells (VSMCs) in vitro and in neointima formation in rat artery after balloon angioplasty in vivo. Exogenous kallistatin induced a >2-fold increase of VSMC proliferation and cell growth as measured by [(3)H]thymidine incorporation and cell counts and a 2.3-fold increase of cell migration in modified Boyden chambers. In balloon-injured vessels, endogenous kallistatin mRNA and protein levels increased up to 10-fold as determined by competitive polymerase chain reaction and by ELISA. Intense staining of kallistatin mRNA was identified in the proliferating VSMCs of balloon-injured arteries during cell migration from media to neointima by in situ hybridization histochemistry and immunohistochemistry. We observed an induction of kallistatin expression by platelet-derived growth factor (PDGF) and upregulation of p42/44 mitogen-activated protein kinase (MAPK) activity by kallistatin in cultured VSMCs. Conversely, adenovirus-mediated transfer of kallistatin antisense cDNA into cultured VSMCs inhibited PDGF-induced p42/44 MAPK activity and cell proliferation. Furthermore, local delivery of adenovirus carrying kallistatin antisense cDNA significantly downregulated kallistatin mRNA levels and attenuated neointima formation in balloon-injured rat arteries in vivo. These results indicate that kallistatin may play an important role in mediating PDGF-induced MAPK pathway on VSMC proliferation and in neointima formation after balloon angioplasty.
激肽释放酶抑制蛋白是一种丝氨酸蛋白酶抑制剂（丝氨酸蛋白酶抑制剂），在血管内皮细胞和平滑肌细胞中表达。通过研究激肽释放酶抑制蛋白在体外培养的原代主动脉血管平滑肌细胞（VSMC）增殖和迁移以及体内大鼠动脉球囊血管成形术后新生内膜形成中的作用，探讨了其在血管生物学中的潜在功能。外源性激肽释放酶抑制蛋白通过[³H]胸腺嘧啶核苷掺入法和细胞计数法测定，使VSMC增殖和细胞生长增加了2倍以上，在改良的Boyden小室中细胞迁移增加了2.3倍。在球囊损伤的血管中，通过竞争性聚合酶链反应和ELISA测定，内源性激肽释放酶抑制蛋白mRNA和蛋白水平增加了10倍。通过原位杂交组织化学和免疫组织化学方法，在球囊损伤动脉的增殖VSMC从介质迁移到新生内膜的过程中，发现激肽释放酶抑制蛋白mRNA有强烈染色。我们观察到血小板衍生生长因子（PDGF）诱导激肽释放酶抑制蛋白表达，并且在培养的VSMC中激肽释放酶抑制蛋白上调p42/44丝裂原活化蛋白激酶（MAPK）活性。相反，腺病毒介导的激肽释放酶抑制蛋白反义cDNA转染到培养的VSMC中可抑制PDGF诱导的p42/44 MAPK活性和细胞增殖。此外，局部递送携带激肽释放酶抑制蛋白反义cDNA的腺病毒可显著下调激肽释放酶抑制蛋白mRNA水平，并减弱体内球囊损伤大鼠动脉的新生内膜形成。这些结果表明，激肽释放酶抑制蛋白可能在介导PDGF诱导的MAPK途径对VSMC增殖以及球囊血管成形术后新生内膜形成中起重要作用。
