Aquaporin-5 (AQP5) Antibody Review

 

 

 

Introduction

  • Aquaporins (AQPs) are a family of channel proteins that allow water or very small solutes to pass, functioning in tissues where the rapid and regulated transport of fluid is necessary, such as the kidney, lung, and salivary glands. PMID: 15986091

  • one of the group of cell membrane transporting proteins. PMID: 16613712

  • a water channel protein expressed on the apical surface of alveolar epithelial type I cells in distal rat lung, suggesting a role for AQP5 in regulating alveolar surface liquid tonicity and/or cell volume. PMID: 17108010, PMID: 15596131

  • an apical plasma membrane (APM) water channel in salivary glands, lacrimal glands, and airway epithelium, has an important role in fluid secretion. PMID: 16712780

  • a water channel protein and is considered to play an important role in water movement across the plasma membrane. PMID: 10022971

Normal Expression

  • a water channel protein expressed on the apical surface of alveolar epithelial type I cells in distal rat lung. PMID: 17108010

  • a water-selective channel protein that is expressed in lacrimal glands, salivary glands, and distal lung. PMID: 17097063

  • Water channel aquaporin 5 (AQP5) is present in the apical membrane of the salivary gland acinar cells. PMID: 16899467

  • AQP5 was strongly labeled in alveolar epithelial type I cells, and was also expressed in the secretory epithelium plasma membrane in the airway. PMID: 16887054

  • expressed in epithelia of lung, cornea, and various secretory glands, sites where extracellular osmolality is known to fluctuate. PMID: 16537379

  • AQP5 is localized in the apical membranes of several different epithelia in vivo, and in stably transfected MDCK-II cells grown as a polarized monolayer. PMID: 16259600

  • AQP5 was detected in the secretory granule membranes by immunoblot analysis. The immunoelectron microscopy experiments confirmed that AQP5 was to be found in the secretory granule membrane. PMID: 15986091

  • AQP5 expressed mainly in the membrane and cytoplasm of the epithelium in the glands, ducts and cilia. PMID: 15952563

  • Aquaporin-5 was found in the apical domain of the acinar cell plasma membrane in healthy BALB/c mice. PMID: 15940770

  • AQP5 is localized mainly in the apical membrane, including intercellular secretory canaliculi of secretory cells in the minor salivary glands, pyloric glands, and duodenal glands. PMID: 14692686

  • AQP5 displayed specific cochlear expression, first detectable at E15.5 in the nonsensory epithelium and later restricted to the lateral wall of the cochlear duct near the spiral prominence. AQP5 expression continued through postnatal periods with a change of expression domain to the stria vascularis between postnatal day 7 (P7) and P14. PMID: 12943377

  • Immunolocalization with specific antibodies revealed strong expression of AQP5 at the luminal membrane of secretory epithelial cells in sweat glands in mouse paw skin. PMID: 12042359

  • skeletal muscle cells express AQP5 protein and its expression is regulated by differentiation and hypertonic stress. PMID: 11989981

  • AQP5 was found in secretory acinar cells of submandibular, parotid, and sublingual glands, where it was restricted to apical membranes including intercellular secretory canaliculi. In the submandibular gland, abundant AQP5 was also found additionally at the apical membrane of intercalated duct cells. Upon stimulation by isoproterenol, apical staining for AQP5 in parotid acinar cells tended to appear as clusters of dots. PMID: 10022971

Abnormal Expression

  • location of AQP5 in hyperoxia groups was not changed, but the expression of AQP5 mRNA had a notable gradual decline when the time of hyperoxia exposure was prolonged, compared to control group (all P<0.05). PMID: 16887054

  • expression of AQP5 in the experimental groups were reduced compared with that in the Air control group 3 days after hyperoxia-exposure and the decrease of AQP5 expression was associated with duration of hyperoxia-exposure. PMID: 16613712

  • level of AQP-5 expression was substantially reduced in animals with long-term anhidrosis, hence implicating water channel impairment as a possible factor in the development of this disorder. PMID: 16412116

  • aquaporin-5 was found in the apical and basolateral acinar plasma cell membrane in parotid, submandibular, and sublingual glands in NOD model of Sjogren's syndrome mice. PMID: 15940770

  • Abnormal distribution of AQP5 in salivary gland acini is likely to contribute to the deficiency of fluid secretion, which is a defining feature of Sjogren's syndrome. PMID: 11232635

Expression Alteration

  • Although several AQP genes are expressed in the uterus, only direct activation of AQP5 could be detected following treatment with estrogen. PMID: 16999734

  • In the basal state, AQP5 was localized mainly in the apical membrane of the acinar cell. It was also present in the basolateral membrane to a lesser extent. When isoproterenol (IPR) was administered to mice, dot-like, vesicle-like and vacuole-like labeling for AQP5 was seen in the subapical regions by light microscopy. By immunoelectron microscopy, AQP5 was localized at both the apical and basolateral plasma membranes in the basal state. At 5 and 30 min after the IPR-administration, acinar lumen became enlarged and small invaginations formed by fusion of secretory granules were seen. AQP5 was positive along the apical plasma membrane and its small invaginations. At 60 min, large invaginations of the lumen were formed. AQP5 remained positive in the membrane of these large invaginations. At 6 h, large invaginations disappeared and AQP5 was localized in the apical plasma membrane. AQP5 was restricted to plasma membranes and continuous invaginations formed by the exocytosis of secretory granules. AQP5 was not detected in the cytoplasm. PMID: 16899467

  • expression of aquaporin-5, the major water channel expressed in alveolar, tracheal, and upper bronchial epithelium, is significantly down-regulated during acute lung injury. PMID: 15482567

Function

  • AQP5 plays an important role in maintaining water homeostasis in the lung. PMID: 17097063

  • hyperosmotic stress is an important activator of AQP-5 in human airway epithelium, leading to significantly increased transepithelial water permeability. PMID: 17043812

  • AQP5 is responsible for the majority of water transport across the apical membrane of type I alveolar epithelial cells. The unimpaired alveolar fluid clearance in AQP5-null mice indicates that high alveolar water permeability is not required for active, near-isosmolar fluid transport. PMID: 10619865

  • restricted expression of AQP5 to the apical turns of the cochlea suggests its potential role in low frequency hearing. PMID: 10527857

  • AQP5 is one of the candidate molecules responsible for the water movement in the salivary glands. PMID: 10022971

Applications

 

Electron Microscopy (EM)

  • We performed immunoperoxidase, immunofluorescence and immunoelectron microscopy to examine changes of AQP5-distribution during the fusion process of secretory granule membranes into the apical membrane and subsequent recovery process in the mouse parotid gland by administering isoproterenol (IPR) in vivo. PMID: 16899467

  • AQP5 was detected in the secretory granule membranes by immunoblot analysis. The immunoelectron microscopy experiments confirmed that AQP5 was to be found in the secretory granule membrane. PMID: 15986091

Immunofluorescence (IF)

  • Expression of aquaporin-5 (AQP5), studied by immunofluorescence and confocal microscopy, showed an increase in parallel with the increase in P ( f ) following hyperosmotic stress. The AQP5 was localized both in cytoplasmic vesicles and in apical cell membranes. PMID: 17043812

  • Localizations of AQP5 and MUC5AC in SPC-A1cells were detected by Immunofluorescence. PMID: 16337839

  • distribution of AQP5 in normal rat nasal mucosa and nasal mucosa in rat with allergic rhinitis were observed by immunofluorescence technique. PMID: 15952563

  • Aquaporin-5 was stained using avidin-biotin-peroxidase complex and indirect immunofluorescence staining methods, and visualized using light and laser scanning confocal microscopy. PMID: 15940770

  • Immunofluorescence and Western blotting strongly suggested that LPS altered AQP5 subcellular distribution from an intracellular vesicular compartment to the plasma membrane. PMID: 15596131

  • We used indirect immunofluorescence and an immunoperoxidase technique to assess expression and subcellular localisation of aquaporin 5 in patients and controls. PMID: 11741631

Immunohistochemistry (IHC)

  • expression of AQP5 mRNA level and the location were detected by reverse transcription-polymerase chain reaction and immunohistochemistry respectively. PMID: 16887054

  • Immunohistochemistry revealed a strong AQP-5-like activity reaction at the apical membrane of the glandular secretory cells, which was absent from the surrounding myoepithelium and all other skin structures. PMID: 16412116

  • expression of AQP5 protein and mRNA in 65 cases epithelial ovarian tumors and 13 cases normal tissue were measured by immunohistochemical technique, Western blotting and RT-PCR, respectively. PMID: 16242760

  • Furthermore, the expression of AQP5 in normal rat nasal mucosa and nasal mucosa from rat with allergic rhinitis were studied by immunohistochemical staining. PMID: 15952563

  • expression of aquaporin-5 was investigated by immunohistochemical studies and by polymerase chain reaction. PMID: 15482567

  • We surveyed the expression and immunohistochemical localization of AQP5 in the rat digestive system. PMID: 14692686

  • Immunohistochemical analysis of the SMG demonstrated that the AQP5 protein was localized in the basal and apical/lateral plasma membrane of acinar cells in rats expressing the high level of AQP5. In the rat expressing the low level, however, this channel protein was localized strongly in the apical/lateral plasma membrane, but only very weakly in the basal membrane of the acinar cells. Such a diverse localization of AQP5 was confirmed by Western blotting as well. PMID: 12466944

  • RT-PCR, immunohistochemistry and Western blot analysis revealed that C2C12 cells express AQP5. PMID: 11989981

Western Blotting (WB)

  • expressions of AQP1 and AQP5 were examined by Western Blot in the lung tissue under hyperoxia. PMID: 16613712

  • Western blot analysis showed that sweat gland cells from freely sweating horses expressed the water channel aquaporin-5 (AQP-5). PMID: 16412116

  • expression of AQP5 protein and mRNA in 65 cases epithelial ovarian tumors and 13 cases normal tissue were measured by immunohistochemical technique, Western blotting and RT-PCR, respectively. PMID: 16242760

  • AQP5 was detected in the secretory granule membranes by immunoblot analysis. The immunoelectron microscopy experiments confirmed that AQP5 was to be found in the secretory granule membrane. PMID: 15986091

  • We analyzed the change in expression of inducible NOS (iNOS), neuronal NOS (nNOS), endothelial NOS (eNOS), aquaporin 1 (AQP1) and aquaporin 5 (AQP5) over time by Western blot. PMID: 14767587

  • By Western blot analysis, the expression level of aquaporin (AQP) 5 in the submandibular gland (SMG) was found to be different among individual rats of the Sprague-Dawley (SD) strain. PMID: 12466944

  • Reverse transcription-polymerase chain reaction and immunoblot analyses revealed that mRNAs encoding AQP1, 4 and 5 (but not 2 or 3) subtypes were expressed in rat middle ear epithelium. PMID: 11506936

  • Immunoblot of cochlear homogenate yielded a predominant AQP5-immunoreactive band of M(r) 35 kDa. PMID: 10527857