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

Liyi Xie, Li Jin, Jie Feng, Jing Lv, Liyi Xie, Li Jin, Jie Feng, Jing Lv

Abstract

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.

Figures

Figure 1
Figure 1
Observation of skin and sweat glands with HE staining. (a) (×40), full-thickness skin showed that sweat gland catheter opened through the epidermis to the skin surface; (b) (×200), subdermal sweat glands are clustered (∗) or distributed separately (#); (c) (×400), the secretion portion (★) and catheter portion (◆) of exocrine sweat glands; (d) (×200), apocrine sweat glands.
Figure 2
Figure 2
Morphologic detection and quantity comparison of sweat gland in human skin. Amounts of sweat glands located in human skin, secretory portion (★), and trochlea portion (◆) are detected. Comparing with the control (a), the shape and size of sweat gland in uremia (b) were of no difference. The number was similar between 3 subgroups (▲ = P > 0.05) (c).
Figure 3
Figure 3
The immunofluorescence examination of the UTs in eccrine sweat glands.
Figure 4
Figure 4
Expression of AQP5, UT-A1, and UT-B1 in skin tissue by immunohistochemistry. (a1), (c1) (×40); (b1), (b2), (b3), (b4) (×200); (a2), (c2), (a3), (c3), (a4), (c4), (a5), (b5), (c5) (×400). FS: full-thickness skin; PC: positive control; UP: uremic patients; NMC: normal controls; NGC: negative control.
Figure 5
Figure 5
Semiquantitative analysis of the expression of AQP5, UT-A1, and UT-B1. Comparison of AQP5, UT-A1, and UT-B1 protein expression in each group. ∗P < 0.01; #P < 0.05.
Figure 6
Figure 6
Expression of AQP5, UT-A1, and UT-B1 mRNA in human skin. ∗P < 0.01; #P < 0.05.
Figure 7
Figure 7
The relative expression of AQP5, UT-A1, and UT-B1 protein in human skin. ∗P < 0.01; #P < 0.05.

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