Scientists map hidden receptor in tear and saliva glands, opening path to new treatments
Researchers have identified and mapped a hormone receptor called GPR173 in the body's tear and saliva glands—marking the first time its role in these tissues has been documented. The discovery could lead to new therapies for autoimmune disorders affecting moisture-producing glands, a significant market opportunity for pharmaceutical developers.
Originaltitel: Spatial characterization of the phoenixin receptor in the lacrimal and major salivary glands.
GPR173-receptorn, kopplad till hormonstyrning och autoimmunitet, uttrycks differentierat i spottkörtlar och tårkörteln — en upptäckt som kan påverka utvecklingen av nya behandlingar för sekretorisktörda tillstånd. Forskare från Istanbul Galata University och Göteborgs universitet undersökte GPR173-uttryck i råttornas större spottkörtlar (parotis, submandibulär, sublingual) samt tårkörteln. Western blotting och immunfluorescens visade att GPR173 förekommer i alla undersökta körtelceller. I spottkörtlarna detekterades receptorn både i acini och i gångepiтel; i tårkörteln endast i acini. Parotis och submandibulär körtel uppvisade signifikant högre uttryck än tårkörteln (p < 0,01 respektive p < 0,05). Gångeepitelet visade starkare immunreaktivitet än acinigevävet. Denna vävnadspecifika lokalisering öppnar vägar för selektiv farmakologisk modulering av sekretion, relevant för utvecklare av antikolinerga alternativ och för kliniker som hanterar sjukdomar som Sjögrens syndrom.
OBJECTIVE: To identify and characterize the expression of phoenixin receptor GPR173 (G protein-coupled receptor 173) in the rat lacrimal and major salivary glands (parotid, submandibular, and sublingual). GPR173 is associated with hormonal regulation and autoimmunity; however, its expression in exocrine glands has yet to be characterized. DESIGN: Under anesthesia, eight Sprague Dawley rats underwent bilateral dissection of the lacrimal and major salivary glands. GPR173 expression was assessed using Western blotting and immunofluorescence. Immunoreactivity was quantified using ImageJ software and compared using the Friedman test with Dunn-Bonferroni post hoc analysis. RESULTS: GPR173 protein expression was found in all examined exocrine glands. In the major salivary glands, GPR173 was detected in both acinar and ductal cells, while expression was confined to acinar cells in the lacrimal gland. The submandibular and parotid glands showed significantly higher immunoreactivity than the lacrimal gland (p < .01 and p < .05, respectively). Ductal epithelium showed stronger immunopositivity compared to acinar epithelium. GPR173 immunoreactivity was also observed in periductal stromal tissue in major salivary glands. CONCLUSION: GPR173 expression was observed in both acinar and ductal cells of all major salivary glands, while in the lacrimal gland, it was restricted to the acinar cells. This differential localization suggests tissue-specific relevance.