Endothelial Lipase Is Localized to Follicular Epithelial Cells in the Thyroid Gland and Is Moderately Expressed in Adipocytes

Abstract

SummaryEndothelial 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. (J Histochem Cytochem 60:694-705, 2012)

Φαρμακογενετική Μελέτη Της Αναστολής Της Ενδοθηλιακής Λιπάσης, Ως Μέσου Αύξησης Της HDL-χοληστερόλης

“…Αθφκα, mRNA ηεο EL έρεη εληνπηζηεί ζηα θπςειηδηθά θχηηαξα ηχπνπ ΗΗ ζηνλ πλεχκνλα, δηαδξακαηίδνληαο πηζαλά ξφιν ζην ζρεκαηηζκφ ηεο ζνπξθαθηάλεο (επηθαλεηνδξαζηηθφο παξάγνληαο πνπ πεξηέρεη θσζθνιηπίδην) 347 . Σέινο, ην κφξην ηεο ΔL έρεη αληρλεπζεί ζε επηπιντθά θχηηαξα θαη ππνδφξηα ιηπνθχηηαξα, ρσξίο λα είλαη γλσζηέο νη ιεηηνπξγίεο ηεο ζε απηνχο ηνπο ηζηνχο 364 . Ζ δηαθνξεηηθή ηζηηθή θαηαλνκή πνπ παξνπζηάδεη ε EL ζε ζρέζε κε εθείλε ηεο LPL (ιηπψδεο ηζηφο, κπτθφο ηζηφο) θαη ηεο HL (ήπαξ) επηβεβαηψλεη ηε δηαθξηηή, κεεπηθαιππηφκελε δξάζε ηεο, παξά ηηο δνκηθέο νκνηφηεηεο κε ηηο άιιεο ιηπάζεο 347 .…”