Dura mater biology: autocrine and paracrine effects of fibroblast growth factor 2.
The dura mater, the outermost layer of the meninges, is thought to be essential for calvarial morphogenesis, postnatal suture fusion, and osseous repair of calvarial defects. Despite numerous studies illustrating the fundamental role of the dura mater, there is little information about the autocrine and paracrine mechanisms regulating dural cell biology during calvarial ossification. Previous work conducted in the authors' laboratory demonstrated that non-suture-associated dural cells from 6-day-old rat pups expressed high levels of fibroblast growth factor 2 (FGF-2), whereas dural cells from 60-day-old adult rats expressed very little FGF-2. Because young mammals can successfully heal large calvarial defects, the authors sought to investigate the autocrine and/or paracrine effects of FGF-2 on the proliferation, gene expression, and alkaline phosphatase production of dural cells. Cultures of non-suture-associated dural cells were established from 6-day-old Sprague-Dawley rat pups and then stimulated with recombinant human FGF-2 (rhFGF-2; 10 ng/ml). Dural cells stimulated with rhFGF-2 proliferated significantly faster than untreated dural cells at 24 hours (2.1 x 10(5) +/- 3.2 x 10(4) versus 1.1 x 10(5) +/- 1.8 x 10(4), p < or = 0.001) and 48 hours (2.3 x 10(5) +/- 4.2 x 10(4) versus 1.2 x 10(5) +/- 1.3 x 10(4), p < or = 0.001). Moreover, dural cells stimulated with rhFGF-2 expressed 7-fold more proliferating cell nuclear antigen than did control cultures. Treatment with rhFGF-2 increased dural cell expression of genes important for skeletal repair: FGF-2 (7-fold), transforming growth factor beta 1 (3-fold), transforming growth factor beta 3 (4-fold), and type I collagen (4-fold). Furthermore, rhFGF-2 increased dural cell expression of osteopontin (2-fold), a "late" marker of osteoblastic differentiation. Interestingly, dural cell alkaline phosphatase activity, an "earlier" marker of osteoblast differentiation, was significantly decreased by treatment with rhFGF-2 compared with control cultures at 24 hours (0.005 +/- 0.001 versus 0.01 +/- 0.003, p < or = 0.01) and 48 hours (0.004 +/- 0.0009 versus 0.01 +/- 0.0009). Together these data provide insight into the autocrine and paracrine effects of FGF-2 on the biology of the dura mater.
Spector
Jason A
JA
Department of Surgery, New York University School of Medicine, NY, USA.
Greenwald
Joshua A
JA
Warren
Stephen M
SM
Bouletreau
Pierre J
PJ
Detch
Robert C
RC
Fagenholz
Peter J
PJ
Crisera
Francesca E
FE
Longaker
Michael T
MT
D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D019898:Autocrine Communication; D015152:Blotting, Northern; D015153:Blotting, Western; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D024042:Collagen Type I / Q000235:genetics / Q000378:metabolism; D004388:Dura Mater / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D016222:Fibroblast Growth Factor 2 / Q000235:genetics / Q000494:pharmacology* / Q000502:physiology; D015870:Gene Expression; D010012:Osteogenesis / Q000502:physiology; D053495:Osteopontin; D019899:Paracrine Communication; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000494:pharmacology; D012795:Sialoglycoproteins / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism; D053773:Transforming Growth Factor beta1; D053782:Transforming Growth Factor beta3
D024042:Collagen Type I; D018809:Proliferating Cell Nuclear Antigen; D011994:Recombinant Proteins; C506895:SPP1 protein, human; D012795:Sialoglycoproteins; C506897:Spp1 protein, rat; C508960:TGFB1 protein, human; C508962:Tgfb1 protein, rat; C509046:Tgfb3 protein, rat; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D053782:Transforming Growth Factor beta3; D016222:Fibroblast Growth Factor 2; D053495:Osteopontin; D000469:Alkaline Phosphatase