Growth/differentiation factor-5 modulates the synthesis and expression of extracellular matrix and cell-adhesion-related molecules of rat Achilles tendon fibroblasts.
This study was designed to examine the cellular and molecular response of tendon fibroblasts to growth/differentiation factor-5 (GDF-5). Rat Achilles tendon fibroblasts (ATFs) were treated in culture with varying concentrations of GDF-5 (0-1000 ng/ml) over varying periods of time (0-12 days). Cell proliferation, evaluated through use of a standard MTT colorimetric assay, confirmed that GDF-5 stimulates ATF proliferation in a concentration- and time-dependent fashion. Temporal and concentration analysis revealed that GDF-5 increases total DNA, glycosaminoglycan (GAG), and hydroxyproline (HYP) content. Ratios of HYP/DNA and GAG/DNA increased with increasing concentrations of GDF-5 (0-1000 ng/ml). Expression of the following 12 extracellular matrix (ECM) and cell-adhesion-related genes was assessed using real-time reverse transcriptase polymerase chain reaction (RT-PCR): collagen I (col I), collagen III (col III), matrix metalloproteinases (MMP)-3 and -13, aggrecan, tissue inhibitor of matrix metalloproteinase (TIMP)-2, syndecan-4, N-cadherin, tenascin-C, biglycan, versican, and decorin. RT-PCR data revealed an increase in the expression of col I, col III, MMP-3, MMP-13, TIMP-2, syndecan-4, N-cadherin, tenascin-C, and aggrecan genes by day 6. A statistically significant decrease in TIMP-2 and MMP-13 was observed on day 12. Decorin expression was depressed at all time points in cells treated with GDF-5. There was no significant change in biglycan expression in ATFs supplemented with GDF-5. These findings suggest that GDF-5 induces cellular proliferation and ECM synthesis as well as expression of ECM and cell-adhesion-related genes in ATFs. This study further defines the influence of GDF-5 on rat ATFs through its action on the expression of genes that are associated with tendon ECM.
Department of Orthopaedic Surgery, Orthopaedic Research Laboratories, University of Virginia Health System, Charlottesville, VA, USA.
Thomas C
TC
Keller
MaCalus V
MV
Hogan
Girish
G
Kesturu
Roshan
R
James
Gary
G
Balian
A Bobby
AB
Chhabra
D000125:Achilles Tendon / Q000166:cytology; D000818:Animals; D015815:Cell Adhesion Molecules / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects; D005109:Extracellular Matrix / Q000378:metabolism*; D005347:Fibroblasts / Q000378:metabolism; D006025:Glycosaminoglycans / Q000096:biosynthesis; D055428:Growth Differentiation Factor 5 / Q000502:physiology*; D008297:Male; D051381:Rats; D011916:Rats, Inbred F344
D015815:Cell Adhesion Molecules; D006025:Glycosaminoglycans; D055428:Growth Differentiation Factor 5