Yamada T, Fan J, Shimokama T, Tokunaga O, Watanabe T
Department of Pathology, Saga Medical School, Japan.
Am J Pathol. 1992 Dec;141(6):1435-44.
In this study a two-compartment culture model of arterial intima was used for the in vitro induction of fatty streaklike lesions. The apparatus consisted of upper and lower compartments separated by a human amnion membrane stretched between them. Human umbilical vein endothelial cells (HUVECs) were cultured to confluence on the stromal surface of the amnion membrane. Maximal migration of blood mononuclear cells (MCs) through the HUVEC monolayer in response to a f-Met-Leu-Phe gradient was observed at 10(-8) mol/l; the migration was 3.29 times greater than that observed under the condition of random migration (control). In the study of MC transformation into lipid-laden cells in the amnion membrane (foam cell formation in 'arterial intima'), 10(6) MCs were incubated, in the presence of freshly prepared low-density lipoprotein (LDL; 100 microgram/ml). The lipid loading of MCs was time dependent. After 12 hours' incubation, 39% of the MCs that migrated into the amnion membrane contained a small number of lipid droplets, whereas the remaining 61% showed no lipid droplets. Only 1.7% of the cells contained a high number of lipid droplets in the cytoplasm and took on the appearance of foam cells. With time, the number of lipid-laden cells and the amounts of intracytoplasmic lipid droplets gradually increased. At 72 hours after incubation, 65.4% of the MCs were loaded with lipid droplets, and 20.9% of them, an eightfold increase over 12 hours of incubation, showed a foamy cell appearance. Because MCs consist of 70% monocytes and 30% lymphocytes, about 93% of the monocytes were filled with lipid after a 72-hour incubation. Ultrastructural examination showed that lipid-laden cells took on macrophage characteristics, such as wide and heterogeneous cytoplasm, indented nuclei, and abundant lysosomes. A minority of the MCs in the amnion were considered lymphocytes; they had scanty cytoplasm, round nuclei with abundant heterochromatin, no lysosomes, and no lipid vacuoles. In conclusion, the formation of an in vitro fatty streaklike lesion is demonstrated, and this is reminiscent of in vivo human atherogenesis.
在本研究中，采用动脉内膜双室培养模型进行体外诱导脂肪条纹样病变。该装置由上下两个隔室组成，中间由一张拉伸的人羊膜隔开。人脐静脉内皮细胞（HUVECs）在羊膜的基质表面培养至汇合。在10(-8)mol/l时观察到血液单核细胞（MCs）通过HUVEC单层对f-Met-Leu-Phe梯度的最大迁移；该迁移比随机迁移条件下（对照）观察到的迁移大3.29倍。在研究MCs在羊膜中转化为脂质负载细胞（“动脉内膜”中的泡沫细胞形成）时，将10(6)个MCs在新鲜制备的低密度脂蛋白（LDL；100μg/ml）存在下孵育。MCs的脂质负载呈时间依赖性。孵育12小时后，迁移到羊膜中的MCs中有39%含有少量脂滴，而其余61%没有脂滴。只有1.7%的细胞在细胞质中含有大量脂滴并呈现出泡沫细胞的外观。随着时间的推移，脂质负载细胞的数量和胞质内脂滴的数量逐渐增加。孵育72小时后，65.4%的MCs含有脂滴，其中20.9%呈现出泡沫细胞外观，比孵育12小时增加了八倍。由于MCs由70%的单核细胞和30%的淋巴细胞组成，孵育72小时后约93%的单核细胞充满脂质。超微结构检查显示，脂质负载细胞具有巨噬细胞特征，如宽阔且异质性的细胞质、凹陷的细胞核和丰富的溶酶体。羊膜中的少数MCs被认为是淋巴细胞；它们的细胞质稀少，圆形细胞核含有丰富的异染色质，没有溶酶体，也没有脂质空泡。总之，证明了体外脂肪条纹样病变的形成，这让人联想到体内人类动脉粥样硬化的发生。
