title: Transforming growth factor-beta 1 (TGF-beta1) prevents the age-dependent decrease in bone formation in human osteoblast/implant cultures.
abstract: Titanium implants have been extensively used in orthopedic surgery and dentistry. Most of the patients who receive such implants are elderly with a compromised ability to heal and form new bone. By using an in vitro osteoblast/implant culture system, the potency of TGF-beta1 in enhancing mineralization of human osteoblast cultures from elderly subjects was investigated in this study. Primary human osteoblast (HOB) cells obtained from different age group human subjects [Young (Y), Middle (M), and Old (O)] were cultured on Ti alloy (Ti-6Al-4V) disks with or without continuous administration of 0.2 ng/mL TGF-beta1 in the medium for 2 or 4 weeks. TGF-beta1 significantly (p < 0.05) increased calcium content and the size of calcified nodules on implant disks in the O group, but had no effect on the Y or M groups. The number of calcified nodules was not different with or without TGF-beta1 in all age groups. As measured by Northern blot analysis and RT-PCR, TGF-beta1 significantly increased the expression of bone-specific extracellular matrix proteins, including alkaline phosphatase, Type I collagen, bone sialoprotein and osteocalcin, after both 2 and 4 weeks in the O group but not in the Y group. In conclusion, TGF-beta1 enhances mineralization on implant materials of osteoblast cultures from elderly human subjects.
authors.affiliation: Department of Restorative Dentistry, University of Washington, Seattle, WA 98195, USA. haizhang@u.washington.edu
authors.forename: Hai
authors.initials: H
authors.lastname: Zhang
authors.forename: Michael S
authors.initials: MS
authors.lastname: Aronow
authors.forename: Gloria A
authors.initials: GA
authors.lastname: Gronowicz
mesh_terms: D020341:Absorbable Implants; D000328:Adult; D000367:Age Factors; D000368:Aged; D000375:Aging; D000469:Alkaline Phosphatase / Q000378:metabolism; D000497:Alloys; D015152:Blotting, Northern; D018786:Bone Substitutes / Q000737:chemistry*; D001842:Bone and Bones / Q000378:metabolism / Q000473:pathology*; D002118:Calcium / Q000737:chemistry / Q000378:metabolism; D002454:Cell Differentiation; D002478:Cells, Cultured; D024042:Collagen Type I / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D058574:Integrin-Binding Sialoprotein; D008856:Microscopy, Fluorescence; D008875:Middle Aged; D010006:Osteoblasts / Q000378:metabolism*; D010012:Osteogenesis; D019736:Prostheses and Implants; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012795:Sialoglycoproteins / Q000378:metabolism; D013997:Time Factors; D014025:Titanium / Q000737:chemistry*; D016212:Transforming Growth Factor beta / Q000737:chemistry / Q000494:pharmacology*; D053773:Transforming Growth Factor beta1
chemical_list: D000497:Alloys; D018786:Bone Substitutes; D024042:Collagen Type I; C546871:IBSP protein, human; D058574:Integrin-Binding Sialoprotein; D012795:Sialoglycoproteins; C508960:TGFB1 protein, human; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; C031462:titanium alloy (TiAl6V4); D004247:DNA; D014025:Titanium; D000469:Alkaline Phosphatase; D002118:Calcium