title: Osteoclast progenitors from cats with and without tooth resorption respond differently to 1,25-dihydroxyvitamin D and interleukin-6.
abstract: Both vitamin D and inflammatory cytokines can stimulate osteoclast formation and activity. We studied the effect of 1,25-dihydroxycholecalciferol (1,25(OH)(2)D), and interleukin-6 (IL-6), on the formation and activity of feline osteoclasts, using peripheral blood mononuclear cells (PBMCs) from cats with and without tooth resorption (TR(+) and TR(-)) as a source of osteoclast precursors. The formation of osteoclast-like cells (defined as multinucleated, tartrate-resistant acid phosphatase-positive cells) was assessed at 7 and 14 days. In the presence of M-CSF and RANKL, with and without IL-6, more osteoclasts were formed from TR(-) PBMCs than from TR(+) PBMCs on plastic. More osteoclasts were formed from TR(+) PBMCs on bone slices in the presence of M-CSF/RANKL with 1,25(OH)(2)D. This opposite effect may be due to a higher expression of the vitamin D receptor (VDR) in TR(+) osteoclasts and precursors on bone. Formation of resorption pits was analyzed and confirmed with scanning electron microscopy. In conclusion, we propose that TR(+) PBMCs when cultured on bone are sensitive to 1,25(OH)(2)D, whereas the differentiation of TR(-) PMBCs on bone seem more sensitive to IL-6, suggesting that osteoclast precursors from cats with and without tooth resorption respond differently to osteoclast stimulating factors.
authors.affiliation: Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 108, P.O. Box 80154, 3508 TD Utrecht, The Netherlands. h.e.booij-vrieling@uu.nl
authors.forename: H E
authors.initials: HE
authors.lastname: Booij-Vrieling
authors.forename: T J
authors.initials: TJ
authors.lastname: de Vries
authors.forename: T
authors.initials: T
authors.lastname: Schoenmaker
authors.forename: M A
authors.initials: MA
authors.lastname: Tryfonidou
authors.forename: L C
authors.initials: LC
authors.lastname: Penning
authors.forename: H A W
authors.initials: HA
authors.lastname: Hazewinkel
authors.forename: V
authors.initials: V
authors.lastname: Everts
mesh_terms: D000818:Animals; D002415:Cats; D002478:Cells, Cultured; D005260:Female; D015850:Interleukin-6 / Q000494:pharmacology*; D008297:Male; D010010:Osteoclasts / Q000187:drug effects* / Q000502:physiology; D013234:Stem Cells / Q000187:drug effects; D013997:Time Factors; D014091:Tooth Resorption / Q000503:physiopathology / Q000662:veterinary*; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000494:pharmacology
chemical_list: D015850:Interleukin-6; D014807:Vitamin D; C097949:1,25-dihydroxyvitamin D