巨噬细胞集落刺激因子对DEL细胞增殖作用的研究

Potential role of macrophage colony-stimulating factor on the proliferation of DEL cells

目的 研究巨噬细胞集落刺激因子对动脉粥样硬化病变处伴随血管平滑肌细胞共同积聚的巨噬细胞的增殖作用及机制。方法 以能分化为巨噬细胞表型的DEL细胞为离体细胞实验模型 ,将富含巨噬细胞集落刺激因子的L92 9细胞条件培养液或重组的人巨噬细胞集落刺激因子加入体外培养的处于静止期的DEL细胞 ,以氚标胸腺嘧啶核苷或 5 溴 尿嘧啶核苷掺入法分别检测DEL细胞DNA的合成。另以Northernblot法检测DEL细胞c fmsmRNA等的表达。结果 1∶8、1∶4和 1∶2稀释的L92 9细胞条件培养液分别使DEL细胞DNA的合成显著增加了 12 0 %、332 %和 739% ,加入抗巨噬细胞集落刺激因子抗体则能明显抑制这种作用 ,且与凝血酶有协同作用 ;重组的人巨噬细胞集落刺激因子以剂量依赖方式促进DEL细胞增殖 ,并调节c fmsmRNA等的表达。结论 巨噬细胞集落刺激因子可能通过自分泌和旁分泌机制影响巨噬细胞及血管平滑肌细胞的增殖 ,从而在动脉粥样硬化血管损害的进展中发挥其重要作用。

Objective The importance of macrophage colony stimulating factor (MCSF) in the control of growth/proliferation of both vascular smooth muscle cells and macrophages confers to this compound a central role in the development of vascular lesions. To gain insight into the mechanisms of macrophage proliferation, the effect of MCSF upon the proliferation of DEL cells was investigated. Methods DEL cell is a monocyte/histiocytic cell line that differentiates along a macrophage lineage following exposure to phorbol ester. It constitutively expresses MCSF and its receptor MCSFR (encoded by c fms). Whether MCSF might play a role in the proliferation of cultured DEL cells was examined. [ 3H] Thymidine or 5 bromo 2 deoxyuridine (BrdU) incorporation was measured following the addition of recombinant MCSF or L929 cell supernatant (as a source of MCSF) to quiescent DEL cells. The expressions of c fms, c myc and jun B were measured by Northern blot. Results In DEL cells, L929 cell supernatant induced DNA synthesis in a dose dependent manner and such an effect could be blunted by pretreatment of L929 cell supernatant with anti mouse MCSF antibody. As compared with the control group, the DNA syntheses with the addition of 1∶8, 1∶4 or 1∶2 diluted L929 cell supernatant were increased by 120%, 332% or 739% respectively (P<0 001). In these cells DNA synthesis could also be triggered in a dose dependent manner by the addition of recombinant human MCSF (0 01 0 1 μg/ml) or thrombin (0 1 2 U/ml). In addition, MCSF modulated the expression of c fms, c myc and junB. Conclusion These findings clearly show that MCSF influences DEL cell proliferation and suggest an autocrine loop activation. It has also been suggested that MCSF play an important role in the development of vascular lesions, which occur during atherosclerotic progression.