Ochoa Cristhiaan D, Baker Haven, Hasak Stephen, Matyal Robina, Salam Aleya, Hales Charles A, Hancock William, Quinn Deborah A
Pulmonary and Critical Care Unit, Massachusetts General Hospital, Bullfinch 148, 55 Fruit Street, Boston, MA 02114, USA.
Am J Respir Cell Mol Biol. 2008 Jul;39(1):105-12. doi: 10.1165/rcmb.2007-0283OC. Epub 2008 Feb 28.
Endothelial cells are subjected to mechanical forces in the form of cyclic stretch resulting from blood pulsatility. Pulmonary artery endothelial cells (PAECs) produce factors that stimulate and inhibit pulmonary artery smooth muscle cell (PASMC) growth. We hypothesized that PAECs exposed to cyclic stretch secrete proteins that inhibit PASMC growth. Media from PAECs exposed to cyclic stretch significantly inhibited PASMC growth in a time-dependent manner. Lyophilized material isolated from stretched PAEC-conditioned media significantly inhibited PASMC growth in a dose-dependent manner. This inhibition was reversed by trypsin inactivation, which is consistent with the relevant factor being a protein(s). To identify proteins that inhibited cell growth in conditioned media from stretched PAECs, we used proteomic techniques and found that thrombospondin (TSP)-1, a natural antiangiogenic factor, was up-regulated by stretch. In vitro, exogenous TSP-1 inhibited PASMC growth. TSP-1-blocking antibodies reversed conditioned media-induced inhibition of PASMC growth. Cyclic stretched PAECs secrete protein(s) that inhibit PASMC proliferation. TSP-1 may be, at least in part, responsible for this inhibition. The complete identification and understanding of the secreted proteome of stretched PAECs may lead to new insights into the pathophysiology of pulmonary vascular remodeling.
内皮细胞受到血液搏动产生的周期性拉伸形式的机械力作用。肺动脉内皮细胞（PAECs）产生刺激和抑制肺动脉平滑肌细胞（PASMC）生长的因子。我们假设暴露于周期性拉伸的PAECs分泌抑制PASMC生长的蛋白质。暴露于周期性拉伸的PAECs的培养基以时间依赖性方式显著抑制PASMC生长。从拉伸的PAEC条件培养基中分离的冻干物质以剂量依赖性方式显著抑制PASMC生长。这种抑制作用可通过胰蛋白酶失活逆转，这与相关因子为蛋白质一致。为了鉴定拉伸的PAECs条件培养基中抑制细胞生长的蛋白质，我们使用蛋白质组学技术，发现血小板反应蛋白（TSP）-1，一种天然抗血管生成因子，在拉伸时上调。在体外，外源性TSP-1抑制PASMC生长。TSP-1阻断抗体逆转条件培养基诱导的PASMC生长抑制。周期性拉伸的PAECs分泌抑制PASMC增殖的蛋白质。TSP-1可能至少部分负责这种抑制作用。对拉伸的PAECs分泌蛋白质组的完整鉴定和理解可能会为肺血管重塑的病理生理学带来新的见解。
