AlphaB-crystallin in lacrimal gland duct and tears.
OBJECTIVE
To investigate alphaB-Crystallin expression and localization in the lacrimal gland and tear fluid.


METHODS
Mouse, rat, porcine, monkey and human lacrimal gland samples were immuno-histochemically and immuno-electron-microscopically stained with various antibodies against alphaB-crystallin. Western- and Northern-blotting was performed to demonstrate the presence of alphaB-crystallin mRNA and protein. Human tear fluid was analyzed for the presence of alphaB-crystallin using dot blotting.


RESULTS
alphaB-Crystallin is located in the lacrimal gland duct cells but not in the acini. Electron microscopically, the protein was frequently found in apical electron-dense granules of lacrimal duct cells, occasionally also in the duct lumina. Western blotting confirmed the presence of alphaB-crystallin in the lacrimal gland, Northern blot samples revealed the presence of alphaB-crystallin mRNA. In the human tear fluid, alphaB-crystallin was present in all samples investigated.


CONCLUSIONS
We demonstrate for the first time that alphaB-crystallin is present in the lacrimal gland. Presence of the protein in apical secretory granules as well as presence in the tear fluid might indicate secretion of alphaB-crystallin into the tear fluid.
May
C A
CA
Department of Anatomy II, Friedrich Alexander Universität, Erlangen, Germany. atmay@anatomie.uni-erlangen.de
Welge-Lüssen
U
U
Jünemann
A
A
Bloemendal
H
H
Lütjen-Drecoll
E
E
D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D015152:Blotting, Northern; D015153:Blotting, Western; D003459:Crystallins / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D007765:Lacrimal Apparatus / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure; D008251:Macaca; D051379:Mice; D016253:Microscopy, Immunoelectron; D008875:Middle Aged; D051381:Rats; D013552:Swine; D013666:Tears / Q000378:metabolism*; D014018:Tissue Distribution
D003459:Crystallins