Identification and localization of aquaporin water channels in human salivary glands
| Autor: | Søren Nielsen, Martin C. Steward, V. Gresz, Gábor Varga, P. T. Hurley, Tivadar Zelles, Tae-Hwan Kwon, R. M. Case |
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| Rok vydání: | 2001 |
| Předmět: |
Pathology
medicine.medical_specialty Physiology Aquaporin Biology Aquaporins Antibodies Salivary Glands stomatognathic system Physiology (medical) medicine Humans Secretion RNA Messenger Aquaporin 4 Aquaporin 3 Water transport Aquaporin 1 Hepatology Salivary gland Reverse Transcriptase Polymerase Chain Reaction Gastroenterology Membrane Proteins Apical membrane Blotting Northern Aquaporin 5 Cell biology medicine.anatomical_structure Blood Group Antigens |
| Zdroj: | American Journal of Physiology-Gastrointestinal and Liver Physiology. 281:G247-G254 |
| ISSN: | 1522-1547 0193-1857 |
| DOI: | 10.1152/ajpgi.2001.281.1.g247 |
| Popis: | Aquaporin (AQP) water channels are expressed in a variety of fluid-transporting epithelia and are likely to play a significant role in salivary secretion. Our aim was to identify and localize the aquaporins expressed in human salivary glands. Total RNA was extracted from human parotid, submandibular, sublingual, and labial glands and from human brain. Expression of aquaporin mRNA was assessed by RT-PCR using specific primers for human AQP1, AQP3, AQP4, and AQP5. All four aquaporins were detected by RT-PCR in all of the glands, and the sequences were confirmed after further amplification with nested primers. Cleaned PCR products were then used as32P-labeled cDNA probes in a semiquantitative Northern blot analysis using glyceraldehyde-3-phosphate dehydrogenase as reference. Only AQP1, AQP3, and AQP5 mRNAs were present at significant levels. AQP localization was determined by immunohistochemistry on paraffin sections using affinity-purified primary antibodies and peroxidase-linked secondary antibodies. Each salivary gland type showed a broadly similar staining pattern: AQP1 was localized to the capillary endothelium and myoepithelial cells; AQP3 was present in the basolateral membranes of both mucous and serous acinar cells; AQP4 was not detected; and AQP5 was expressed in the luminal and canalicular membranes of both types of acinar cell. We conclude that AQP3 and AQP5 together may provide a pathway for transcellular osmotic water flow in the formation of the primary saliva. |
| Databáze: | OpenAIRE |
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