Rat adipose-derived stromal cells expressing BMP4 induce ectopic bone formation in vitro and in vivo.
OBJECTIVE
Bone morphogenetic protein 4 (BMP4) is one of the main local contributing factors in callus formation in the early phase of fracture healing. Adipose-derived stromal cells (ADSC) are multipotent cells. The present study was conducted to investigate the osteogenic potential of ADSC when exposed to adenovirus containing BMP4 cDNA (Ad-BMP4).


METHODS
ADSC were harvested from Sprague-Dawley rats. After exposure to Ad-BMP4, ADSC were assessed by alkaline phosphatase activity (ALP) assay, RT-PCR and von Kossa staining. BMP4 expression was assessed by RT-PCR, immunofluorescence and Western blot analysis. ADSC transduced with Ad-BMP4 were directly injected into the hind limb muscles of athymic mice. ADSC Ad-EGFP(enhanced green fluorescence protein) served as controls. All animals were examined by X-ray film and histological analysis.


RESULTS
The expression of BMP4 was confirmed at both mRNA and protein levels. The expression of the osteoblastic gene, ALP activity and von Kossa staining confirmed that ADSC transduced with Ad-BMP4 underwent rapid and marked osteoblast differentiation, whereas ADSC transduced with Ad-EGFP and cells left alone displayed no osteogenic differentiation. X-ray and histological examination confirmed new bone formation in athymic mice transplanted with ADSC transduced with Ad-BMP4.


CONCLUSIONS
Our data demonstrated successful osteogenic differentiation of ADSC transduced with Ad-BMP4 in vitro and in vivo. ADSC may be an ideal source of mesenchyme lineage stem cells for gene therapy and tissue engineering.
Lin
Lin
L
Institute of Sports Medicine, Peking University Third Hospital, Beijing 100083, China.
Fu
Xin
X
Zhang
Xin
X
Chen
Lian-xu
LX
Zhang
Ji-ying
JY
Yu
Chang-long
CL
Ma
Kang-tao
KT
Zhou
Chun-yan
CY
D000256:Adenoviridae / Q000235:genetics; D017667:Adipocytes / Q000166:cytology; D000818:Animals; D055415:Bone Morphogenetic Protein 4; D019485:Bone Morphogenetic Proteins / Q000096:biosynthesis* / Q000235:genetics; D002454:Cell Differentiation; D002478:Cells, Cultured; D005822:Genetic Vectors; D008297:Male; D051379:Mice; D008819:Mice, Nude; D010006:Osteoblasts / Q000166:cytology / Q000378:metabolism*; D010012:Osteogenesis; D053495:Osteopontin / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics; D017154:Stromal Cells / Q000166:cytology / Q000378:metabolism* / Q000637:transplantation; D014161:Transduction, Genetic
C525810:Bmp4 protein, mouse; C525811:Bmp4 protein, rat; D055415:Bone Morphogenetic Protein 4; D019485:Bone Morphogenetic Proteins; D012333:RNA, Messenger; D011994:Recombinant Proteins; D053495:Osteopontin