Expression of MDR1 (Multidrug Resistance) Gene and Its Protein in Normal Human Kidney

• Published in: Nephron Vol. 77; no. 3; pp. 284 - 289
• Main Authors: Ernest, Sylvain, Rajaraman, Srinivasan, Megyesi, Judit, Bello-Reuss, Elsa N.
• Format: Journal Article
• Language: English
• Published: Basel, Switzerland S. Karger AG 1997
• Subjects: Antibodies, Monoclonal; ATP-Binding Cassette, Sub-Family B, Member 1 - analysis; ATP-Binding Cassette, Sub-Family B, Member 1 - genetics; ATP-Binding Cassette, Sub-Family B, Member 1 - immunology; Chloride Channels - physiology; Gene Expression; Glomerular Mesangium - chemistry; Glomerular Mesangium - cytology; Humans; Immunohistochemistry; In Situ Hybridization; Kidney - chemistry; Kidney - cytology; Kidney Tubules - chemistry; Kidney Tubules - cytology; Original Paper; RNA Probes; RNA, Messenger - analysis; RNA, Messenger - genetics; P-glycoprotein; MDR1; In situ hybridization; Multidrug resistance
• ISSN: 1660-8151; 2235-3186
• DOI: 10.1159/000190289

P-glycoprotein (Pgp), the product of the multidrug resistance (MDR) gene overexpressed in cancer cells, is present also in normal tissues. In the kidney, MDR1 Pgp has been found in the proximal tubule and in cultured mesangial cells. In situ hybridization and immunohistochemistry were used to determine the complete nephronal localization of MDR mRNA and its product, Pgp, in the human kidney. MDR mRNA expression was studied with the use of non-radioactive in situ MDR RNA probes. MDR1 Pgp was immunolocalized using the specific monoclonal antibody MRK16. The presence of MDR mRNA was confirmed in proximal tubules and mesangium, and demonstrated as well in thick limb of Henle’s loops and in collecting ducts. MDR1 Pgp colocalized in the same nephronal segments. This suggests that, in addition to secreting xenobiotics, Pgp may play a role in the transport of endogenous substrates or in the regulation of Cl- channels.