Figure 1 shows that AQP3, AQP4, and AQP5 are all expressed in secretory glands, such as salivary and lacrimal glands.
28) In addition, Beroukas and coworkers reported a 38% decrease in AQP1 of SS patients, but found no differences in levels of AQP3 and AQP5.
Regarding the topical ingredient, it increased the in vitro AQP3 promoter activity (up to 96%), AQP3 transcription (up to 131%), cellular viability after a dehydration stress (up to 35% more protection and up to 22% more recovery) and type I collagen synthesis (up to 61%).
Topically, Diffuporine promotes AQP3 presence and protects from dehydration as well, complementing the oral hydrating efficacy.
Functional expression of AQP3 in human skin epidermis and reconstructed epidermis.
AQP1 was reported to be selectively expressed in the microvasculature, and AQP2 and AQP3 are commonly expressed in epithelial cells in various organs.
11] In this previous study by Spector and colleagues, the authors showed that dehydration in rats led to a significant upregulation of AQP2 and AQP3 expression, thus providing presumptive evidence that AQPs are involved in water and solute transport.
Other AQP channels, designated AQP3 and AQP4, are always present (constitutive) on the plasma side of the CD cells and facilitate the unregulated exodus of water from these cells (Figure 3B).
Such rapid reabsorption in the PCT and descending loop of Henle is facilitated by a high density of AQP1 and AQP3 (Figure 3A).