Objective: We investigated whether the Hippo pathway participated in SMG development and if it interacted with the metabolic pathway of N-glycosylation.
Method: SMGs were dissected from mice at embryonic day 13.5, epithelial rudiments were separated from the mesenchyme and grown in vitro in the presence and absence of siRNA to DPAGT1. After 48 hours, SMGs were processed for immunofluorescence staining for F-actin, ZO-1 and TAZ and analyzed by confocal microscopy.
Result: Confocal imaging showed colocalization of F-actin and ZO-1 extending further into the ductal region in DPAGT1-silenced glands compared to controls. TAZ was detected at the apical-lateral surfaces of differentiating duct cells, suggesting its role in polarity. Moreover, in DPAGT1 silenced glands, TAZ exhibited enhanced localization to intercellular junctions.
Conclusion: Our findings show that inhibition of N-glycosylation promotes establishment of apical domains in ductal progenitors by ZO-1. In addition, the Hippo pathway component, TAZ, is expressed in the embryonic SMG, localizing to intercellular junctions in ductal cells, which is enhanced by partial inhibition of DPAGT1. These data suggest an inverse relationship between N-glycosylation and the Hippo pathway.
Keywords: Cell biology, Hippo Pathway and Salivary glands