Aquaporin 5 (AQP5) is a water channel protein primarily expressed in fluid-secreting and -absorbing tissues, such as salivary and lacrimal glands, respiratory epithelium, and corneal cells. It facilitates selective water transport across cell membranes, maintaining osmotic balance and hydration. AQP5 dysfunction is linked to pathologies like Sjögren’s syndrome (impaired exocrine gland function), cystic fibrosis, and certain cancers.
Antibodies targeting AQP5 are critical tools for research and diagnostics. They enable detection and localization of AQP5 in tissues via techniques like immunohistochemistry, Western blotting, or immunofluorescence. These antibodies help elucidate AQP5’s role in physiological processes (e.g., saliva production, airway hydration) and disease mechanisms. For instance, reduced AQP5 expression in Sjögren’s syndrome correlates with glandular hypofunction, while its overexpression in tumors may influence metastasis.
Commercial AQP5 antibodies are typically raised in rabbits or mice, using peptide immunogens from conserved regions of the human protein. Validation includes specificity checks using knockout controls or siRNA. Challenges include cross-reactivity with other aquaporins (e.g., AQP1 or AQP3) due to structural homology. Reliable antibodies are vital for studying AQP5’s regulation, interactions, and therapeutic targeting in diseases like dry eye syndrome or pulmonary edema.