The Expression of AQP5 and UTs in the Sweat Glands of Uremic Patients

PURPOSE: To research the distribution and quantitative changes of UT-A1, UT-B1, and AQP5 in uremic skin tissue. METHODS: 34 cases of uremic patients (UP) and 11 controls were recruited. Immunohistochemistry, immunofluorescence, RT-PCR, and Western Blot were used to identify the proteins in sweat glands. RESULTS: AQP5, UT-A1, and UT-B1 were expressed and localized in human skin basal lines, skin sweat glands, and sweat ducts, both in UP and controls. Compared to controls, AQP5 mRNA abundance was significantly decreased in UP (P < 0.01), and, with the decrease of eGFR, the AQP5 expression was significantly decreased (P < 0.05). By contrast, UT-A1 and UT-B1 mRNA abundance was significantly increased in the skin of UP compared with the control (P < 0.01), and, with the decrease of eGFR, the AQP5 expression was significantly increased (P < 0.05). We found that the gene changes were coincident with the corresponding target proteins. The urea transporter subtypes, UT-A1 and UT-B1, were expressed in the skin basal cell layer and exocrine sweat glands. The abundance of UT-A1 and UT-B1 in uremic sweat glands was significantly increased in UP, while the expression of AQP5 was decreased. CONCLUSION: Elimination of urea through the skin by producing sweat is a potential therapeutic strategy for renal failure patients.