[Study on evaluating sex determining region of the Y as an engrafting track of BMSCs transplantation for repairing osteonecrosis of the femoral head of rabbit].
OBJECTIVE
To evaluate sex determining region of the Y (Sry) as a engrafting track of the transplanted BMSCs survival and new bone formation in the osteonecrosis of the femoral head (ONFH) of rabbit.


METHODS
Forty-nine 4-5-month-old New Zealand White rabbits were included, weighing 2.0-2.5 kg, 48 females and 1 male. BMSCs of the rabbits were isolated by density gradient separation method, the third passage cells were marked by 1, 1'-dioctadecyl-3, 3, 3', 3'-tetramethylindocarbocyanine perchlorate (DiI) and the concentration of cell suspension was 2.5 x 10(8)/mL. The animal model of ONFH were established with 48 female rabbits by injecting liquid nitrogen, and femoral head was not dislocated. The animal model were divided into 3 groups, 16 rabbits in each group. Group A only established animal model as control. Autologous BMSCs (4 microL) marked by DiI was transplanted in the ONFH models of the group B. Allogenic BMSCs (4 microL) marked by DiI was transplanted in ONFH models of the group C. The femoral head were observed by X-ray, HE staining and Masson staining, and the regenerating trabecular volume percentages was determined at 2, 4, 6 and 8 weeks after operation respectively. The examples of the heart, lung, liver, spleen and kidney were obtained. The transplanted BMSCs were traced by fluorescence microscope, the Sry gene expression was detected by PCR for cells survival.


RESULTS
All rabbits survived till the end of experiment. The X-ray showed gradual necrosis in the femoral head of group A. HE and Masson staining results indicated that compared with the group A, the recovery condition of the necrotic femoral head in the groups B and C was better. At each time of groups B and C, the regenerating trabecular volume percentages were higher than that of the group A significantly (P < 0.01). There was no significant difference between groups B and C (P > 0.05). The cells marked by DiI were not founded in the tissues of the heart, lung, liver, spleen and kidney in groups B and C at each time. PCR showed that the expression of Sry gene were not observed at the heart, lung, liver, spleen and kidney of three groups at each time. The expression of Sry gene was clearly identified in the femoral head of all 16 rabbits in the group C at each time point.


CONCLUSIONS
Allografting of BMSCs transplanted into the femoral head can survive and induce new bone formation without redistribution.
Deng
Bing
B
General Hospital of Chengdu Military Command, Chengdu Sichuan, 610083, PR China.
Quan
Yi
Y
Pan
Xianming
X
Zhang
Bo
B
Liao
Dongfa
D
Jiang
Kai
K
Ma
Zehui
Z
Zhou
Jingsong
J
Liu
Jinbiao
J
Rong
Weiping
W
D000818:Animals; D033481:Chromosomes, Mammalian; D005260:Female; D005271:Femur Head Necrosis / Q000601:surgery*; D024282:Genes, sry; D006085:Graft Survival; D008297:Male; D045164:Mesenchymal Stem Cell Transplantation / Q000379:methods*; D011817:Rabbits; D014945:Wound Healing