Janssen Research and Development, Janssen Pharmaceutical Companies of Johnson and Johnson, Spring House, PA 19477, USA.
J Histochem Cytochem. 2012 Sep;60(9):694-705. doi: 10.1369/0022155412454110. Epub 2012 Jun 26.
Endothelial lipase (EL), a member of the triglyceride lipase gene family, has been shown to be a key player in HDL metabolism. Northern blots revealed that EL was highly expressed in endothelium, thyroid, lung, placenta, liver, and testis. In liver and adrenal gland, EL protein was localized with vascular endothelial cells but not parenchymal cells. EL was shown to be upregulated in tissues such as atherosclerotic plaque where it was located in macrophages, endothelial cells, and medial smooth muscle cells. The purpose of this study was to investigate the cellular localization of EL in thyroid and other tissues where EL is known to be expressed. Besides its presence in vascular endothelial and smooth muscle cells, EL protein was detected in the epithelial cells that line the follicles within the thyroid gland. EL-specific immunostaining was also found near the cell surface as well as in the cytoplasm of adipocytes. Using immunoblots, EL expression was confirmed in cultured human omental and subcutaneous adipocytes. EL expression, however, was not found in preadipocytes. These findings suggest that EL plays a role in thyroid and adipocyte biology in addition to its well-known role in endothelial function and HDL metabolism.
内皮脂肪酶（EL）是甘油三酯脂肪酶基因家族的成员，它被证明是 HDL 代谢的关键因子。Northern blot 显示 EL 在血管内皮细胞、甲状腺、肺、胎盘、肝脏和睾丸中高表达。在肝脏和肾上腺中，EL 蛋白定位于血管内皮细胞，但不是实质细胞。EL 在动脉粥样硬化斑块等组织中被上调，其位置在巨噬细胞、内皮细胞和中膜平滑肌细胞中。本研究旨在研究 EL 在甲状腺和其他已知表达 EL 的组织中的细胞定位。除了存在于血管内皮细胞和平滑肌细胞中外，EL 蛋白还在甲状腺滤泡内的上皮细胞中被检测到。EL 特异性免疫染色也在脂肪细胞的细胞表面附近以及细胞质中被发现。通过免疫印迹，在培养的人网膜和皮下脂肪细胞中证实了 EL 的表达。然而，在脂肪前体细胞中没有发现 EL 的表达。这些发现表明，EL 除了在血管内皮功能和 HDL 代谢中发挥作用外，还在甲状腺和脂肪细胞生物学中发挥作用。
