氧化低密度和极低密度脂蛋白对单核细胞血小板源性生长因子B链表达的影响

The Effects of Oxidized Low Density Lipoprotein and Very Low Density Lipoprotein on Platelet Derived Growth Factor B-chain Expression in Monocytes

在单核细胞的培养基中分别加入２５ｍｇ·Ｌ￣（－１）低密度脂蛋白（ｌｏｗｄｅｎｓｉｔｙｌｉｐｏｐｒｏｔｅｉｎ，ＬＤＬ）、氧化ＬＤＬ（ｏｘｉｄｉｚｅｄＬＤＬ，ＯＬＤＬ）、极低密度脂蛋白（ｖｅｒｙｌｏｗｄｅｎｓｉｙｌｉｐｏｐｒｏｔｅｉｎ，ＶＬＤＬ）和氧化极低密度脂蛋白（ｏｘｉｄｉｚｅｄＶＬＤＬ，ＯＶＬＤＬ），培养２４ｈ后再用无血浆脂蛋白培养基收集条件培养基，并观察此条件培养基对￣３Ｈ－ＴｄＲ投入血管壁平滑肌细胞ＤＮＡ的影响。用抗血小板源性生长因子Ｂ链抗体（抗ＰＤＧＦ－Ｂ抗体）作疫组织化学染色。结果表明，单核细胞能表达ＰＤＧＦＢ，ＯＬＤＬ和ＯＶＬＤＬ能明显地促进单核细胞ＰＤＧＦ－Ｂ的表达，其条件培养基亦能促进￣３Ｈ－ＴｄＲ掺入平滑肌细胞ＤＮＡ内。上述结果提示，ＯＬＤＬ和ＯＶＬＤＬ通过加强单核细胞分泌ＰＤＧＦ－Ｂ并促进平滑肌细胞增殖而在动脉粥样硬化的发病过程中起作用。

It is very clear that hyperlipemia is a risk factor of atherosclerosis. To further understand the role of lipoproteins, especially oxidized lipoproteins in atherogenesis, we examined the effects of oxidized low density lipoprotein (OLDL) and very low density lipoprotein (OVLDL) on platelet-derived growth factor Bchain (PDGF-B) expression in monocytes. Methods Low density lipoprotein (LDL) and very low density lipoprotein (VLDL) were isolated from normal blood donors by density gradient ultracentrifugation. After exposed to LDL, OLDL, VLDL, and OVLDL for 24 hours and subsequently exposed to lipoprotein-free media for 24 hours, respectively, monocytes were used to immunocytochemical staining by anti-PDGF-B antibody, meanwhile the conditioned by cultured monocytes media were collected. and their influences on 3H-TdR incorporation into DNA of smooth muscle cells were observed.Results Monocytes can express PDGF-B, and OLDL and OVLDL enhance the expression; the monocyte conditioned media also can promote the 3HM-TdR incorpation into DNA of smooth muscle cells. Conclusions OLDL and OVLDL may play an important role in pathogenesis of atherosclerosis through stimulating the secreation of PDGF-B in monocytes, that promotes the proliferation of smooth muscle cells.