title: Sevelamer restores bone volume and improves bone microarchitecture and strength in aged ovariectomized rats.
abstract: Sevelamer hydrochloride, a noncalcium phosphate binder, has been shown to reduce coronary artery and aortic calcification, and to improve trabecular bone mineral density in hemodialysis patients with chronic kidney disease. Here, we examined whether sevelamer given orally for 12 wk with normal food could restore bone volume (BV) and strength in aged ovariectomized (OVX) rats starting at 4 wk after OVX. Dual-energy x-ray absorptiometry, microcomputerized tomography, and bone histomorphometry analyses showed that OVX animals receiving sevelamer had increased trabecular BV (51%), trabecular number (43%), trabecular thickness (9%), cortical thickness (16%), mineral apposition rate (103%), bone formation rate (25%), and enhanced cortical and trabecular bone mechanical strength as compared with OVX rats. Sevelamer decreased collagen C telopeptide, increased osteocalcin levels, and decreased phosphate and magnesium levels without affecting calcium levels in the blood. Although sevelamer was not absorbed systemically, it stimulated osteoblast differentiation in BM-derived mesenchymal stem cell cultures, as evaluated by alkaline phosphatase positive colony-forming units, and inhibited recombinant human soluble receptor activator of nuclear factor-kappaB ligand-induced osteoclast differentiation, as evaluated by tartrate-resistant acid phosphatase positive cells in bone mineral-hematopoietic stem cell cultures. Surface enhanced laser desorption/ionization time-of-flight mass spectrometry analysis revealed that 69 proteins were differently expressed after OVX, of which 30% (20 of 69) were reversed to sham activity after sevelamer intake. PTH, fibroblast growth factor-23, and cytokine profile in serum were not significantly changed. Together, these results suggest that sevelamer in food increases the BV and improves biomechanical properties of bone in OVX rats.
authors.affiliation: Genzyme Corporation, Framingham, Massachusetts 01701, USA. kuber.sampath@genzyme.com
authors.forename: T Kuber
authors.initials: TK
authors.lastname: Sampath
authors.forename: Petra
authors.initials: P
authors.lastname: Simic
authors.forename: Sarah
authors.initials: S
authors.lastname: Moreno
authors.forename: Nikolay
authors.initials: N
authors.lastname: Bukanov
authors.forename: Natasa
authors.initials: N
authors.lastname: Draca
authors.forename: Vera
authors.initials: V
authors.lastname: Kufner
authors.forename: Ana
authors.initials: A
authors.lastname: Tikvica
authors.forename: Andrew
authors.initials: A
authors.lastname: Blair
authors.forename: Damir
authors.initials: D
authors.lastname: Semenski
authors.forename: Mladen
authors.initials: M
authors.lastname: Brncic
authors.forename: Steven K
authors.initials: SK
authors.lastname: Burke
authors.forename: Slobodan
authors.initials: S
authors.lastname: Vukicevic
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D015519:Bone Density / Q000187:drug effects*; D001846:Bone Development / Q000187:drug effects; D001842:Bone and Bones / Q000187:drug effects* / Q000378:metabolism; D002478:Cells, Cultured; D016207:Cytokines / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D010010:Osteoclasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D010052:Ovariectomy; D011073:Polyamines / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D000069603:Sevelamer; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D055114:X-Ray Microtomography
chemical_list: D016207:Cytokines; D011073:Polyamines; D000069603:Sevelamer