Bone induction by BMP-2 transduced stem cells derived from human fat.
OBJECTIVE
We have isolated pluripotent mesenchymal progenitor cells in large numbers from liposuction aspirates (processed lipoaspirate cells or PLAs). This study examines the osteogenic potential of PLAs and bone marrow aspirate cells (BMAs), when exposed to either recombinant human bone morphogenetic protein (BMP)-2 (rh-BMP-2) or adenovirus containing BMP-2 cDNA (Ad-BMP-2).


METHODS
Liposuction aspirates underwent proteolytic digestion to obtain PLAs. After exposure to exogenous rh-BMP-2 or Ad-BMP-2 for four or seven days, PLAs and BMAs were assessed by histochemistry, spectrophotometry and RT-PCR. Western blotting and ELISA confirmed BMP gene transduction. Results were compared to osteoblasts and cells in osteogenic media only. PLA-Ad-BMP-2 cells were seeded on matrices and implanted in the hind limbs of SCID mice.


RESULTS
Analysis of quantified bone precursor assays including extracellular ALP histomorphometry, intracellular ALP spectrophotometry, and calcified extracellular matrix (von Kossa) histomorphometry revealed that PLAs treated with exogenous rh-BMP-2 or transduced with a BMP-2 containing adenovirus (PLA-Ad-BMP-2) produced more bone precursors than osteoblasts (p=0.001). PLAs treated with exogenous rh-BMP-2 or PLA-Ad-BMP-2 also produced more bone precursors than BMAs (p=0.001), except for day 7 ALP histomorphometry (p=0.343). ELISA confirmed successful BMP-2 production by both progenitor cell groups transduced with Ad-BMP-2. H&E sections from collagen I matrices seeded with PLA-Ad-BMP-2 cells confirmed bone formation at six weeks.


CONCLUSIONS
Liposuction aspirates contain PLAs that can be transfected with the BMP-2 gene, with rapid induction into the osteoblast phenotype at a rate comparable to rh-BMP-2 and osteoblast groups. Transduced PLAs produce more bone precursors with faster onset of calcified extracellular matrix than transduced BMAs. PLAs may be an ideal source of mesenchyme-lineage stem cells for gene therapy and tissue engineering.
Dragoo
Jason L
JL
Laboratory for Regenerative Bioengineering and Repair, Department of Surgery, UCLA School of Medicine, 90095-6092, USA.
Choi
Joon Y
JY
Lieberman
Jay R
JR
Huang
Jerry
J
Zuk
Patricia A
PA
Zhang
Jeffery
J
Hedrick
Marc H
MH
Benhaim
Prosper
P
D000256:Adenoviridae / Q000235:genetics; D000273:Adipose Tissue / Q000166:cytology*; D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000235:genetics*; D001842:Bone and Bones / Q000166:cytology*; D002454:Cell Differentiation; D002460:Cell Line; D003094:Collagen; D018076:DNA, Complementary; D015870:Gene Expression; D006801:Humans; D007763:Lac Operon; D015187:Lipectomy; D051379:Mice; D016513:Mice, SCID; D010006:Osteoblasts / Q000502:physiology / Q000637:transplantation; D010012:Osteogenesis; D039904:Pluripotent Stem Cells / Q000166:cytology* / Q000502:physiology; D011994:Recombinant Proteins; D015503:Surgical Sponges; D023822:Tissue Engineering / Q000379:methods*; D014162:Transfection; D016212:Transforming Growth Factor beta
C525718:BMP2 protein, human; C525719:Bmp2 protein, mouse; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D018076:DNA, Complementary; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C499469:recombinant human bone morphogenetic protein-2; D003094:Collagen; D000469:Alkaline Phosphatase