Induction of calbindin D-28K in Madin-Darby bovine kidney cells by 1,25(OH)2D3

• Published in: Kidney international Vol. 45; no. 1; pp. 95 - 102
• Main Authors: Gagnon, AnneMarie, Simboli-Campbell, Maura, Welsh, JoEllen
• Format: Journal Article Conference Proceeding
• Language: English
• Published: New York, NY Elsevier Inc 01.01.1994; Nature Publishing
• Subjects: Animals; Biological and medical sciences; Biomarkers; Blood Physiological Phenomena; Calbindins; Calcitriol - pharmacology; Cattle; Cell Division; Cell Line; Dogs; Fundamental and applied biological sciences. Psychology; Kidney - cytology; Kidney - metabolism; Kidney Tubules, Distal - metabolism; Receptors, Calcitriol - metabolism; S100 Calcium Binding Protein G - metabolism; Swine; Vertebrates: urinary system; Bovine; Calcium; Cholecalciferol(1,25-dihydroxy); Experimental study; In vitro; Biological activity; Kidney; Cuspid; Binding protein; Vertebrata; Renal tubule; Mammalia; Urinary system; Established cell line; Artiodactyla; Ungulata
• ISSN: 0085-2538; 1523-1755
• DOI: 10.1038/ki.1994.11

Induction of calbindin D-28K in Madin-Darby bovine kidney cells by 1,25(OH)2D3. Renal calbindin D-28K is a calcium binding protein, localized to the distal nephron, whose expression is reduced in vitamin D deficiency and increased upon administration of 1,25(OH)2D3, the active form of vitamin D. Investigation into the molecular regulation of renal calbindin D-28K expression has been limited by the lack of an established cell line which expresses calbindin D-28K in a vitamin D responsive manner. In the studies described here, we compared the expression of calbindin D-28K and the vitamin D receptor (VDR) in four renal cell lines: Madin-Darby bovine kidney (MDBK) cells, Madin-Darby canine kidney (MDCK) cells, LLC-PK1 pig kidney cells and opossum kidney (OK) cells. We report that MDBK cells express the highest relative levels of calbindin D-28K and the VDR, and that 1,25(OH)2D3 increases calbindin D-28K expression in these cells. No expression of calbindin D-28K was detected in MDCK, LLC-PK1 or OK cells. Kinetic studies indicated that calbindin D-28K protein increased with time for up to 24 hours after a single dose of 1,25(OH)2D3 (10-7M) in MDBK cells. Immunofluorescence studies indicated that in control MDBK cells, the majority of calbindin D-28K was localized in cytosol, with a definite concentration in the peri-nuclear region. In 1,25(OH)2D3 treated cells, calbindin D-28K was enhanced in cytosol and was detected within the nucleus. In contrast to heterogeneous primary culture systems, in which a minority of cells express calbindin D-28K, virtually all MDBK cells expressed calbindin D-28K, even in the absence of 1,25(OH)2D3. In summary, MDBK cells represent the first established renal cell line identified which expresses calbindin D-28K in a vitamin D responsive manner, providing a model in which to examine the molecular regulation of calbindin D-28K by 1,25(OH)2D3.