Na+/K+-ATPase in the lacrimal glands of rabbits and its changes during induced autoimmune dacryoadenitis

PURPOSE To test the hypothesis that expression of Na(+)/K(+)-ATPase subunits in the lacrimal glands (LGs) of rabbits with induced autoimmune dacryoadenitis (IAD) changes. METHODS LGs were obtained from adult female rabbits with IAD and age-matched female control rabbits. The LGs were processed for laser capture microdissection (LCM), real time RT-PCR, western blot, and immunofluorescence for the detection of mRNA and proteins of the α1, α2, β1, β2, and β3 subunits of Na(+)/K(+)-ATPase. RESULTS In the rabbits with IAD, mRNA levels of α1, β1, and β3 from whole LGs were significantly lower. In samples of acini and epithelial cells from various duct segments, collected by LCM, mRNA levels of α1, β1, β2, and β3 were significantly lower in the rabbits with IAD, although mRNA for α2 could not be detected. However, western blots demonstrated that all five subunits were significantly higher in the rabbits with IAD, although their distribution patterns were similar to those of the control rabbits, as demonstrated by immunofluorescence. CONCLUSIONS The data presented herein demonstrated significant changes in mRNA and protein expressions of Na(+)/K(+)-ATPase subunits in rabbits with IAD, suggesting that these changes may play a role in the pathogenesis of Sjögren's syndrome and altered LG secretion, as observed in these animals.