Interferon-α Upregulates Gene Expression of Aquaporin-5 in Human Parotid Glands
Document Type
Article
Publication Date
9-6-1999
Description
Aquaporins are a family of homologous membrane proteins that function as highly selective water channels. Aquaporin-5 (AQP5) is uniquely present in lacrimal and salivary glands, where it accounts for normal tear and saliva production. We tested the hypothesis that orally administered human interferon-α (HuIFN-α) benefits persons with xerostomia by augmenting the production of AQP5 protein by parotid gland epithelium. Cells from three human parotid glands were cultured with and without human lymphoblastoid IFN- α, and assayed for AQP5 mRNA levels by reverse transcriptase polymerase chain reaction (RT-PCR), and AQP5 protein levels by Western blot. Intracellular localization of AQP5 protein was done using confocal microscopy. The functional integrity of the glandular tissue was confirmed by RT-PCR analysis of α-amylase 1 and basic proline-rich protein transcripts. AQP5 was constitutively expressed in human parotid gland tissue, with AQP5 protein restricted to the plasma membranes and cytoplasmic vesicles of acinar cells. IFN-α augmented AQP5 transcription and protein production in a concentration-dependent manner, and increased the size of intensity of staining of AQP5-containing cytoplasmic vesicles in acinar cells. We conclude that IFN-α upregulates AQP5 gene expression in human parotid acinar cells in vitro. To our knowledge, this is the first demonstration that IFN-α regulates the gene expression of an aquaporin.
Citation Information
Smith, J. Kelly; Siddiqui, Afzal A.; Modica, Louis A.; Dykes, Rhesa; Simmons, Christy; Schmidt, Julie; Krishnaswamy, Guha A.; and Berk, Steven L.. 1999. Interferon-α Upregulates Gene Expression of Aquaporin-5 in Human Parotid Glands. Journal of Interferon and Cytokine Research. Vol.19(8). 929-935. https://doi.org/10.1089/107999099313479 PMID: 10476940 ISSN: 1079-9907