Aquaporins in Health and Disease: An Overview Focusing on the Gut of Different Species

Abstract

Aquaporins (AQPs) play a pivotal role in gut homeostasis since their distribution and function is modulated both in physiological and in pathophysiological conditions. The transport of water and solutes through gut epithelia is essential for osmoregulation and digestive and absorptive functions. This passage is regulated by different AQP isoforms and characterized by their peculiar distribution in the gastrointestinal tract. To date, AQP localization has been identified in the gut and associated organs of several mammalian species by different techniques (immunohistochemical, western blotting, and RT-PCR). The present review describes the modulation of AQP expression, distribution, and function in gut pathophysiology. At the same time, the comparative description of AQP in animal species sheds light on the full range of AQP functions and the screening of their activity as transport modulators, diagnostic biomarkers, and drug targets. Moreover, the phenotype of knockout mice for several AQPs and their compensatory role and the use of specific AQP inhibitors have been also reviewed. The reported data could be useful to design future research in both basic and clinical fields.

Expression, Distribution and Role of Aquaporin Water Channels in Human and Animal Stomach and Intestines

“…The current review summarized the possibilities of AQPs as potential therapeutic targets in gastrointestinal disorders. Other important tissues in the gastrointestinal tract (such as salivary glands, liver, pancreas and gallbladder) are also very vital for gut functioning, and the roles of AQPs in these important tissues have been well summarized in recent reviews [ 17 , 120 ]. More investigations are required to elucidate the regulatory signal pathways for AQPs’ expression, localization and distribution changes in gut physiology and pathology.…”

“…Water can be secreted as digestive juices and then be absorbed by the gastrointestinal epithelia [ 3 , 14 ], which are classified as leaky (small intestine), moderately tight (gastric antrum and colon) and tight (gastric fundus) epithelia, respectively [ 15 ]. Thus, research regarding the specific expression, distribution and roles of AQPs in stomach and intestines of human and animals has attracted much attention in the past two decades [ 1 , 3 , 11 , 16 , 17 ].…”

Unveiling the Mechanisms of Aquaglyceroporin‐3 Water and Glycerol Permeation by Metadynamics

“…[4] The latter subfamily can also be permeated by other uncharged solutes, includingu rea and hydrogen peroxide (H 2 O 2 ). [8,9] AQP3 is presenti nv arious tissues, such as kidney, [8] gut [10] the respiratory tract [11] and skin. [8,9] AQP3 is presenti nv arious tissues, such as kidney, [8] gut [10] the respiratory tract [11] and skin.…”

“…[5][6][7] In humans,1 3A QP isoforms (AQP0-AQP12) exist, among which aquaglyceroporin-3( AQP3) is known to be permeable to glycerol, [8] H 2 O 2 , [5] ammonia [9] and urea. [8,9] AQP3 is presenti nv arious tissues, such as kidney, [8] gut [10] the respiratory tract [11] and skin. [12] Additionally,i th as been found to be expressedi nvarious cancer types.…”

Laxative Effects of Total Diterpenoids Extracted from the Roots of Euphorbia pekinensis Are Attributable to Alterations of Aquaporins in the Colon

“…AQPs, as water channels, have been involved in water transport in the intestinal tract [ 15 ], playing critical roles in the transcellular route in the colon. So far, 13 types of AQPs have been discovered in mammals [ 16 ]. AQPs that are mainly expressed in mucosal epithelial cells in the colon are AQP3 and AQP4 [ 17 , 18 ], and AQP1 is mostly expressed in microvessels.…”