To test the hypothesis that expressions of Na-K-2Cl cotransporter-1 (NKCC1), cystic fibrosis transmembrane conductance regulator (CFTR), and chloride channel 2 γ subunit (ClC2γ) in the lacrimal glands (LGs) of rabbits with induced autoimmune dacryoadenitis (IAD) are changed.
LGs were obtained from adult female rabbits with IAD and age-matched female control rabbits. LGs were processed for laser capture microdissection, real-time reverse transcription-polymerase chain reaction, Western blot, and immunofluorescence.
In rabbits with IAD, messenger RNA (mRNA) abundance and protein expressions of NKCC1 and CFTR from whole LGs were significantly lower than those in controls. mRNA abundance of NKCC1, CFTR, and ClC2γ from rabbits with IAD was significantly different from that in acinar and ductal cells from controls. NKCC1 was localized to the basolateral membranes of all acinar and ductal cells, with weaker staining intensity in ductal cells, and the staining pattern from rabbits with IAD appeared similar to that from controls. CFTR was found as punctate aggregates in the apical cytoplasm of all acinar and ductal cells, with the intensity in ductal cells much stronger and no significant difference between controls and rabbits with IAD. ClC2γ was also localized to the apical cytoplasm as punctate aggregates of all acinar cells but not in ductal cells, and a similar staining pattern was observed in rabbits with IAD compared with control rabbits.
Our data demonstrated significant changes of mRNA and protein expressions of NKCC1, CFTR, and ClC2γ in rabbits with IAD, suggesting that these changes may contribute to the altered lacrimal secretion, particularly Cl transport, in rabbits with IAD.