Calara F, Ameli S, Hultgårdh-Nilsson A, Cercek B, Kupfer J, Hedin U, Forrester J, Shah P K, Nilsson J
Division of Cardiology, Cedars-Sinai Medical Center, Los Angeles, Calif, USA.
Arterioscler Thromb Vasc Biol. 1996 Feb;16(2):187-93. doi: 10.1161/01.atv.16.2.187.
To determine whether replication of arterial smooth muscle cells (SMCs) in response to mechanical injury would occur in the absence of serum and other cells, we created an in vitro model in which confluent, growth-arrested cultures of rat SMCs were injured by gentle pressure of a soft plastic tube and then kept in serum-free medium for up to 4 days. Replication of SMCs in and around the injury, as measured by tritiated thymidine incorporation, was noted within 24 hours and peaked at 48 hours after injury, whereas noninjured cells remained quiescent. An increased expression of platelet-derived growth factor (PDGF) A mRNA, noted 6 hours after injury, was followed by an increased PDGF AA immunoreactivity in SMCs in and around the zone of injury at 24 and 48 hours after injury. A PDGF A chain antisense oligonucleotide inhibited 87.0 +/- 4.0% (P < .005) of SMC replication in the injury zone, whereas the corresponding sense oligonucleotide reduced SMC replication by only 37.2%. An antibody to fibroblast growth factor (FGF) almost completely inhibited SMC replication in the injured zone, whereas an antibody to PDGF AA was without effect. Incubation of SMCs with FGF increased PDGF A mRNA levels in SMCs, and 5 mumol/L PDGF A antisense oligonucleotides reduced FGF-induced SMC replication by 62%. Taken together, these results demonstrate that injured rat SMCs in culture release FGF that activates DNA synthesis of neighboring SMCs both by a direct mechanism and by stimulating the production of PDGF AA.
为了确定在无血清和其他细胞的情况下，动脉平滑肌细胞（SMC）是否会因机械损伤而发生复制，我们创建了一个体外模型，在该模型中，将汇合且生长停滞的大鼠SMC培养物通过软塑料管的轻柔压力进行损伤，然后在无血清培养基中培养长达4天。通过氚标记胸腺嘧啶核苷掺入法测量，损伤处及其周围的SMC在损伤后24小时内开始复制，并在48小时达到峰值，而未损伤的细胞则保持静止。损伤后6小时观察到血小板衍生生长因子（PDGF）A mRNA表达增加，随后在损伤后24小时和48小时，损伤区域及其周围的SMC中PDGF AA免疫反应性增加。PDGF A链反义寡核苷酸抑制了损伤区域87.0±4.0%（P<.005）的SMC复制，而相应的正义寡核苷酸仅使SMC复制减少了37.2%。成纤维细胞生长因子（FGF）抗体几乎完全抑制了损伤区域的SMC复制，而PDGF AA抗体则无效。用FGF孵育SMC可增加SMC中PDGF A mRNA水平，5μmol/L的PDGF A反义寡核苷酸使FGF诱导的SMC复制减少了62%。综上所述，这些结果表明，培养中的损伤大鼠SMC释放FGF，该因子通过直接机制和刺激PDGF AA的产生来激活相邻SMC的DNA合成。
