Leakage of aquaporin 5 in the tear of dacryoadenitis mice.
OBJECTIVE
The objective of this study was to investigate whether leakage of aquaporin 5 (AQP5) in tear is associated with damage of lacrimal glands (LGs) in dacryoadenitis models.


METHODS
Female MRL/lpr (24-week-old), male NOD/Shi Jci (5-, 8-, and 10-week-old), female NFS/s-TX (10-week-old), and lipopolysaccharide (LPS)-induced dacryoadenitis model mice were used. Tear fluid was collected by a cotton thread. Tear proteins in the thread were dissolved in sodium dodecyl sulfate buffer, and AQP5 proteins were analyzed by the Western blot technique using anti-AQP5 antibody. LGs were prepared for hematoxylin and eosin staining or immunostaining of AQP5.


RESULTS
In MRL/lpr, NFS/s-TX, 8- and 10-week-old NOD/Shi Jci mice, AQP5 protein was detected in the tear by Western blot analysis. Inflammatory lymphocyte infiltrations were observed in LGs of these dacryoadenitis model mice. In contrast, AQP5 leakage and damage of LG were not observed in normal mice. In 5-week-old NOD/Shi Jci mice, infiltration was not seen in LG, and AQP5 leakage was not detected in the tear. In LPS-induced dacryoadenitis model mice, either tissue destruction with inflammation in LG or AQP5 leakage in the tear was observed. AQP5 in the tear and tissue inflammation in LGs was not found in control mice. These results indicate that AQP5 is leaked in tears when LGs are damaged by dacryoadenitis.


CONCLUSIONS
Leakage of AQP5 in the tear was found to be related to LG damage. This finding suggests that detection of AQP5 in tear is useful for specific diagnosis of LG disorders with tissue destruction.
Hirai
S
S
Discovery Research Division, Santen Pharmaceutical Co., Ltd., Ikoma, Japan. shirai@mahoroba.ne.jp
Ishida
N
N
Watanabe
K
K
Mita
S
S
D000818:Animals; D051402:Aquaporin 5; D020346:Aquaporins / Q000378:metabolism*; D015153:Blotting, Western; D003607:Dacryocystitis / Q000175:diagnosis / Q000378:metabolism*; D005136:Eye Proteins / Q000378:metabolism*; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D015151:Immunoblotting; D007765:Lacrimal Apparatus / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008565:Membrane Proteins; D051379:Mice; D019463:Mice, Inbred MRL lpr; D016688:Mice, Inbred NOD; D013666:Tears / Q000378:metabolism*
C496038:Aqp5 protein, mouse; D051402:Aquaporin 5; D020346:Aquaporins; D005136:Eye Proteins; D008565:Membrane Proteins; C042434:tear proteins