title: Vascular endothelial cell participation in formation of lymphoepithelial lesions (epi-myoepithelial islands) in lymphoepithelial sialadenitis (benign lymphoepithelial lesion).
abstract: Lymphoepithelial lesions (LELs, or epi-myoepithelial islands) in lymphoepithelial sialadenitis (LESA, or benign lymphoepithelial lesion) of the salivary gland are known to be mainly composed of duct epithelial cells. However, other constituent cells are poorly characterized. Formalin-fixed paraffin sections obtained from six surgical specimens of LESA were examined using immunohistochemistry for cytoskeletal proteins, inflammatory cells, vascular endothelial cells, and extracellular matrix (ECM) molecules as well as by in situ hybridization for ECM molecules. In addition to keratin-immunopositive (+) duct-like epithelial cells, there were CD31/CD34+ vascular endothelial cells-which were either scattered in a singular fashion, in formed sheets, or in tubular structures-, CD20+ B lymphocytes, CD45RO+ T lymphocytes, and CD68 macrophages in the LELs. ECM molecules, such as heparan sulfate proteoglycan and tenascin, were immunolocalized in hyaline materials in the LELs. Their mRNAs were demonstrated mainly in endothelial cells and, to a lesser extent, in lympho-monocytic cells around hyaline materials, but were not as evident in epithelial constituent cells of LELs. The results indicate that endothelial cells as well as inflammatory cells are important constituents of the LELs, and the hyaline ECM cores mainly result from the intra-LEL angiogenesis by endothelial cells with the assistance of inflammatory cells. This intra-LEL vasculature seems to support regeneration and proliferation of salivary epithelial remnant cells.
authors.affiliation: Division of Oral Pathology, Department of Tissue Regeneration and Reconstruction, Niigata University Graduate School of Medical and Dental Sciences, 2-5274 Gakkocho-dori, 951-8514 Niigata, Japan.
authors.forename: Hamdy
authors.initials: H
authors.lastname: Metwaly
authors.forename: Jun
authors.initials: J
authors.lastname: Cheng
authors.forename: Hiroko
authors.initials: H
authors.lastname: Ida-Yonemochi
authors.forename: Kazufumi
authors.initials: K
authors.lastname: Ohshiro
authors.forename: Kai Yu
authors.initials: KY
authors.lastname: Jen
authors.forename: Ai Ru
authors.initials: AR
authors.lastname: Liu
authors.forename: Takashi
authors.initials: T
authors.lastname: Saku
mesh_terms: D015703:Antigens, CD / Q000378:metabolism; D015415:Biomarkers / Q000032:analysis; D004730:Endothelium, Vascular / Q000378:metabolism / Q000473:pathology*; D004847:Epithelial Cells / Q000378:metabolism / Q000473:pathology*; D016326:Extracellular Matrix Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007124:Immunoenzyme Techniques; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D012333:RNA, Messenger / Q000378:metabolism; D012466:Salivary Gland Diseases / Q000378:metabolism / Q000473:pathology*; D012469:Salivary Glands / Q000378:metabolism / Q000473:pathology*; D012793:Sialadenitis / Q000378:metabolism / Q000473:pathology*
chemical_list: D015703:Antigens, CD; D015415:Biomarkers; D016326:Extracellular Matrix Proteins; D012333:RNA, Messenger