title: Antisense oligodeoxynucleotide evidence that a unique osteoclastic protein-tyrosine phosphatase is essential for osteoclastic resorption.
abstract: This study tested the hypothesis that a unique osteoclastic transmembrane protein tyrosine phosphatase (PTP-oc) is involved in osteoclastic resorption by determining whether suppression of PTP-oc expression with a specific phosphorothioated 20-mer PTP-oc antisense oligodeoxynucleotide (oligo) would inhibit basal, 1,25-dihydroxyvitamin D3 [1,25(OH)2D3]-stimulated, and PTH-stimulated osteoclastic resorption. Treatment of rabbit osteoclasts with 1 microM of the antisense oligo for up to 4 days showed a time-dependent reduction in PTP-oc protein level, indicating that this PTP-oc antisense oligo was effective. To assess the effect of PTP-oc antisense oligo on osteoclastic resorption, rabbit osteoclasts were pretreated for 3 days with 1 microM of the antisense, a scramble oligo, or vehicle, respectively, followed by a 3-day treatment with vehicle, 10 nM of 1,25(OH)2D3, or 10 nM of parathyroid hormone (PTH). 1,25(OH)2D3 and PTH each alone increased PTP-oc cellular level and stimulated resorptive activity of rabbit osteoclasts. The antisense oligo treatment, but not the scramble oligo, decreased the basal and the stimulated resorption activity and reduced the PTP-oc protein level. Treatment with the PTP-oc antisense oligo, but not the scramble oligo, also markedly increased the Y527 phosphorylation level of c-src in rabbit osteoclasts. In conclusion, these results provide the first antisense oligo evidence that PTP-oc plays an essential role in osteoclastic resorption.
authors.affiliation: Department of Medicine and Biochemistry, Loma Linda University and J L. Pettis Memorial VAMC, California 92357, USA.
authors.forename: S M
authors.initials: SM
authors.lastname: Suhr
authors.forename: S
authors.initials: S
authors.lastname: Pamula
authors.forename: D J
authors.initials: DJ
authors.lastname: Baylink
authors.forename: K H
authors.initials: KH
authors.lastname: Lau
mesh_terms: D000818:Animals; D001862:Bone Resorption / Q000201:enzymology*; D002117:Calcitriol / Q000494:pharmacology; D002478:Cells, Cultured; D015232:Dinoprostone / Q000494:pharmacology; D020319:Oligodeoxyribonucleotides, Antisense; D010010:Osteoclasts / Q000166:cytology / Q000187:drug effects / Q000201:enzymology* / Q000502:physiology; D010281:Parathyroid Hormone / Q000494:pharmacology; D010446:Peptide Fragments / Q000494:pharmacology; D017027:Protein Tyrosine Phosphatases / Q000235:genetics / Q000378:metabolism*; D011817:Rabbits
chemical_list: D020319:Oligodeoxyribonucleotides, Antisense; D010281:Parathyroid Hormone; D010446:Peptide Fragments; D017027:Protein Tyrosine Phosphatases; D002117:Calcitriol; D015232:Dinoprostone