Premium
Keratinisation status and cytokeratins of the human Meibomian gland epithelium
Author(s) -
KNOP E,
LUDESCHER M,
KNOP N
Publication year - 2009
Publication title -
acta ophthalmologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.534
H-Index - 87
eISSN - 1755-3768
pISSN - 1755-375X
DOI - 10.1111/j.1755-3768.2009.2232.x
Subject(s) - cytokeratin , meibomian gland , epithelium , pathology , keratin , sweat gland , anatomy , sebaceous gland , hair follicle , staining , immunohistochemistry , infundibulum , basement membrane , biology , medicine , sweat , endocrinology , eyelid , surgery
Purpose The Meibomian gland (MG) is an indispensable component of the functional anatomy of the ocular surface. Increasing evidence points to a high impact of hyper‐keratinisation as a major cause of obstructive MG dysfunction (MGD) and evaporative dry eye. Information of normal keratinisation status and cytokeratin composition of the human MG is limited. Methods Conjunctival whole‐mount specimens including the lid margin from ten body donors of older age were embedded in paraffin. Serial sections were stained by H&E and Masson‐Goldner stain and by immunohistochemistry with an antibody panel to cytokeratins. Results In conventional stains, the MG shows distinct similarities with the pilo‐sebaceous unit of the cilia. The keratinised skin epithelium extended into the terminal part of the MG excretory duct similar to the hair follicle. Preliminary IHC results showed that the epithelium was positive there for the skin keratin CK10. Along the central duct the keratinisation CK10 expression was gradually lost similar to keratinisation marker involucrin. However, filaggrin, a marker for incipient stages of keratinisation and located in keratohyalin granules continued in the superficial layer of the duct epithelium all along the Meibomian central ductal system. CK14 a marker for basal undifferentiated cells showed a homogenous expression all along the basal cell layer of the MG ducts and the acini. Conclusion The MG shares similarities with the cilia in embryology, in structure and in the cytokeratin composition. It can hence be regarded as a “hair without a hair shaft”. All parts of the MG ducts have signs of incipient keratinisation and preserve a commitment to keratinisation. Upregulation in MGD explain hyper‐keratinisation as a typical event in obstructive MGD.