Activation of transient receptor potential vanilloid subtype 1 serves as a novel path-way to modulate secretion in submandibular gland / 北京大学学报(医学版)

ABSTRACT

SUMMARY Our work focused on the studies on the expression and function of transient receptor poten -tial vanilloid subtype 1 ( TRPV1) in the submandibular gland .By using reverse transcription-polymerase chain reaction ( RT-PCR ) , Western blotting , and immunofluorescence , our data demonstrated the expression and distribution characteristics of TRPV 1 in rabbit and human submandibular glands , as well as rat submandibular gland cell line SMG-C6.Furthermore, the possible intracellular signal molecules involved in the TRPV1-modulated saliva secretion were explored .Activation of TRPV1 increased the intracellular Ca2+concentration, upregulated the expression of aquaporin 5 (AQP5), the main transpor-ter that mediate water secretion through transcellular pathway , and led to AQP5 redistribution .Extracel-lular signal-regulated kinase 1/2 ( ERK1/2 ) was involved in the TRPV1-regulated AQP5 content. Besides, TRPV1 activation also modulated the expression , distribution, and function of tight junction protein, and increased paracellular permeability .ERK1/2 and myosin light chain 2 ( MLC2 ) were responsible for the regulation of TRPV1on tight junction properties.Taken together, our work suggested that TRPV1 was a potential target to promote saliva secretion , and activation of TRPV1 might provide a new and safe therapeutic strategy to ameliorate submandibular gland hypofunction .