The mechanism of matrix-synthesis and-degradation in vascular smooth muscle cells.

为了解血管平滑肌细胞（SMC）表型调节与基质重塑过程的关系，建立了血管平滑肌细胞表型调节的体外培养模型。通过血清浓度和最终细胞密度的变化来验证培养条件。采用Western blotting和酶免疫法检测基质金属蛋白酶（MMPs）及其抑制剂（TIMPs）的表达。同时测定了胶解活性和凝胶解活性。MMP-1、TIMP-1-3和MMP-1rrIMP-1在增殖表型细胞中的表达和活性最高。MMP-2的表达不随SMC表型而改变。制备了表达TIMP-1的腺病毒载体，并利用该载体进行SMC表型或功能分析。胞外基质的数量也通过细胞周期调控基因的功能调节SMC表型。细胞周期蛋白依赖性激酶抑制剂p2lWaf-1在体外培养的SMC和人动脉粥样硬化病变中均有较多表达。p2lWaf-1在增殖细胞中表达增强，符合G0-G1过渡。在体内，这种表达主要在新内膜动脉粥样硬化病变中发现。p21Waf-1可能不仅在细胞周期阻滞中起作用，而且在适当的细胞周期进程中起作用。表达p21Waf-1的腺病毒载体诱导SMC细胞周期阻滞和肥大，但不促进细胞再分化和凋亡。综上所述，基质降解是SMC的一个重要功能，并与SMC的表型相协调调节。这些SMC功能可能由内源性和外源性生长因子信号介导。增殖被认为受到细胞周期调节蛋白的严格调控，如p21Waf-1，其功能可能调节SMC表型。这些发现可能有助于理解血管平滑肌细胞的生物学。腺病毒介导的基因转移方法在本项目中使用，可能意味着临床改变人类动脉粥样硬化的治疗意义。少

To understanding the relationship between phenotypic modulation of vascular smooth muscle cells (SMC), and matrix remodeling process, in vitro culture model for the phenotypic modulation of SMC was established. The culture conditions were verified by the alteration of serum-concentration and final cell densities. The expressions of matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) were determined with Western blotting and enzyme immunoassays. Collogenolytic activity and gelationolytic activity were also measured. The Expressions and activities of MMP-1, TIMP-1-3, and MMP-1rrIMP-1 expressions were maximal in the cells displaying the proliferative phenotype. MMP-2 expression was not changed with SMC phenotypes. The adenovirus vector expressing TIMP-1 was prepared and the analysis for SMC phenotypes or functions using this vector is addressing.The amount of extra-cellular matrix also regulates SMC phenotypes via the function of cell-cycle regulatory genes. The expression patte … More rn of p2lWaf-1, cyclin-dependent kinase inhibitor was observed in either cultured SMC or human atherosclrotic lesions. p2lWaf-1 expression was enhanced in the proliferating cells in accordance with G0-G1 transition. In vivo, the expression was dominantly detected in neo-intimal atherosclerotic lesions. p21Waf-1 may contribute not only in cell-cycle arrest, but also in an appropriate cell cycle progression. Adenovirus vector expressing p21Waf-1 induced cell cycle arrest and hypertrophy in SMC, but not promoted re-differentiation and apoptosis.In conclusion, Matrix-degradation is an important function of SMC, which is coordinately regulated with SMC phenotypes. These SMC functions may be mediated by both endogenous and exogenous growth factor signalings. Proliferation is considered to be tightly regulated by cell-cycle regulatory proteins, such as p21Waf-1, of which function may modulate SMC phenotypes. These finding may contribute to understanding the biology of vascular smooth muscle cells. The adenovirus-mediated gene transfer method used in this project, may imply clinical alteration of human atherosclerosis in the therapeutic implications. Less