Water channel proteins in the gastrointestinal tract

Laforenza, Umberto

doi:10.1016/j.mam.2012.03.001

Cited by 156 publications

(145 citation statements)

References 74 publications

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“…The presence of AQP4 protein in mouse colon was additionally confirmed with the use of Western blot analysis (Cao et al 2014). It must be, however, kept in mind that in the rat colon no immunoreaction for AQP4 was detected (Koyama et al 1999) and human colon contains only low levels of AQP4 mRNA (Laforenza 2012), which strongly points to the existence of species-dependent differences. Since transepithelial osmotic water permeability in the colon of mice lacking AQP4 gene was significantly decreased, it is generally accepted that AQP4 plays a role in the regulation of the colonic fluid flow (Wang et al 2000).…”

Section: Discussionmentioning

confidence: 91%

“…Interestingly, it is evident that a number of aquaporin types can be found in the mammalian gut. Immunohistochemistry combined with RT-PCR studies indicated that mRNAs encoding AQP1, AQP3-5, AQP7-8 and AQP10-11 are commonly present in normal gastric tissues (Laforenza 2012). The use of specific primary antibodies raised against various types of aquaporins revealed the expression of AQP1, AQP4-5, AQP7, AQP9-11 in samples from the small intestine of certain animal species Arciszewski et al 2011;Jiang et al 2014).…”

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confidence: 99%

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Immunohistochemical localization of aquaporin 4 (AQP4) in the porcine gastrointestinal tract

2015

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The water channel aquaporin-4 (AQP4) is a protein widely expressed on plasma membrane of a variety of epithelial cells. In this study we investigated the expression of AQP4 in the gastrointestinal tract of the pig using immunohistochemical staining. We found no presence of AQP4 in the different regions of the pig stomach. In the porcine small intestine moderate immunoreactivity to AQP4 was detected in enterocytes (along the villi and in the bottom of the crypts), duodenal Brunner's glands and in enteric ganglia in cells lying in close vicinity to myenteric as well as submucous neurons. In superficial epithelial cells of the colonic mucosa as well as of caecal and colonic glands a very strong immunoreactivity to AQP4 was found. Both in the myenteric and submucous ganglia of the large intestine AQP4-positive cells surrounding enteric neurons were observed. We concluded that AQP4 expression in the porcine gastrointestinal tract showed some species-dependent differences in relation to other species. Based on the presented distribution pattern of AQP4, it is likely that the aquaporin plays a role in mucous (but not acid) secretion and intestinal absorptive processes in the pig. Aquaporins, gut, small intestine, large intestine, pig

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Section: Discussionmentioning

confidence: 91%

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confidence: 99%

Immunohistochemical localization of aquaporin 4 (AQP4) in the porcine gastrointestinal tract

2015

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“…7L/day) that is secreted in the mouth and stomach. Most fluids are absorbed again together with nutrients in the small intestine, but it is in the colon where most water absorption and solidification of the faeces takes place [189]. In the small intestine the secretion and uptake relies on isotonic mechanisms while in the colon the water uptake goes against an osmotic gradient.…”

Section: Water Homeostasis In the Intestinementioning

confidence: 99%

“…AQPs play a pivotal role for normal gastrointestinal homeostasis, all from the secretion of saliva where AQP5 plays an important role [191][192][193], through the water-tight regulated stomach where AQP1, 3 and 4 play major roles in the secretion of gastric juices [189,[194][195][196] and the small intestine, where enterocytes immense bidirectional water transport where AQP1, 3, 7, 10 and 11 are expressed [189,195,197] to the ascending colon where primarily AQP1, 3, 7, 8 and 11 are present [198][199][200]. Several studies have displayed the importance of AQPs in faecal concentration/water absorption in the colon.…”

Section: Aquaporins In Gastrointestinal Homeostasis and Diarrhoeamentioning

confidence: 99%

Aquaporins in Infection and Inflammation

Holm¹

2016

Linköping University Medical Dissertations

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About the cover:The front cover displays a human, blood-derived macrophage stained for aquaporin 9.During the course of the research underlying this thesis, Angelika Holm was enrolled in Forum Scientium, a multidisciplinary doctoral programme at Linköping University Printed by LiU-Tryck, Linköping, Sweden, 2016 "Be brave, even if you're not, pretend to be. No one can tell the difference."To that young, awkward, tall girl who dared to dream of something else, something more:You did it. SUPERVISOR Elena VikströmDepartment of Clinical and Experimental Medicine Linköping University Linköping Sweden When cells of the innate immune system encounter pathogens they need to respond and prepare for migration and phagocytosis and do so through volume regulatory processes. The Gramnegative bacterium Pseudomonas aeruginosa utilizes a small molecule-based communication system, called quorum sensing (QS) to control the production of its virulence factors and biofilms. We found that P. aeruginosa with a complete QS system elicits a stronger phagocytic response in human blood-derived macrophages compared to its lasI-/rhlI-mutant lacking the production of the QS molecules N-butyryl-L-homoserine lactone (C4-HSL) and N-3-oxododecanoyl-L-homoserine lactone (3O-C12-HSL). Infection with P. aeruginosa further increases the expression of AQP9 and induces re-localisation of AQP9 to the front and trailing ends of macrophages. Moreover, the 3O-C12-HSL alone elevates the expression of AQP9, redistribute the water channel to the front and rear ends and increases the cell area and volume of macrophages. Both infection with the wild type P. aeruginosa and the treatment with 3O-C12-HSL change the nano-structural architecture of the AQP9 distribution in macrophages. ASSISTANT SUPERVISORS Karl-Eric MagnussonViruses use the intracellular machinery of the invaded cells to produce and assemble new viral bodies. Intracellular AQPs are localised in a membranes of cellular organelles to regulate their function and morphology. C3H10T1/2 fibroblasts transiently expressing green fluorescent protein (GFP)-AQP6 show a reduced expression of AQP6 after Hazara virus infection and an increased cell area. Overexpressing AQP6 in C3H10T1/2 cells reduces the infectivity of Hazara virus indicating that AQP6 expression has a protective role in virus infections.Ion and water channels in the epithelial cell lining tightly regulate the water homeostasis. In microscopic colitis (MC), patients suffer from severe watery diarrhoeas. For the first time, we have shown that the expression of AQP1, 8 and 11 and the sodium/hydrogen exchanger NHE1 are reduced in colonic biopsies from MC patients compared to healthy control individuals. Following treatment with the glucocorticoid budesonide the patients experienced a rapid recovery and we observed a restored or increased expression of the AQPs and NHE1 during treatment, suggesting a role for AQPs in the diarrhoeal mechanisms in MC.Taken together, this thesis provides new evidence on the importance of water homeostasis regulatio...

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“…Pertaining to the catalytic activity of Nox1 and Duox2, both enzymes are involved in trans-membrane generation of superoxide generation which is generally thought to be rapidly dismutated to H 2 O 2 . Thereafter, H 2 O 2 may be transported back across the plasma membrane, likely via aquaporins, for cytoplasmic signaling functions [57][58][59].…”

Section: The Generation Of Physiological Levels Of Reactive Oxygen Spmentioning

confidence: 99%