自体脂肪干细胞移植对兔骨质疏松的影响

Effects of transplantation of autologous adipose-derived stem cells on osteoporosis in a rabbitovariectomy model

目的观察自体脂肪干细胞（adipose．derivedstemcells，ASCs）移植对双侧卵巢切除术后骨质疏松（ovariectomyosteoporosis，OVX—OP）兔的影响。方法15只成年新西兰雌性大白兔随机分为OVX模型组（A组，n=12）与假手术组（B组，n=3）。A组行双侧卵巢切除术，B组行假手术。术后6个月，A、B组行双能量x线吸收测定（dualenergyX-rayabsorptiometry，DXA）检测骨密度（bonemineraldensity，BMD），验证造模效果。取OP兔皮下脂肪，体外培养并成骨诱导ASCs，行细胞计数，碱性磷酸酶（alkalinephosphatase，ALP）、茜素红染色及骨钙素（osteocalcin，OCN）等检测。取第3代成骨诱导ASCs复合藻酸钙凝胶（calciumalginatehydrogel，CAH），于OP模型兔左侧股骨远端注射ASCs—CAH，而右侧股骨注射单纯CAH材料作为治疗对照组。移植12周后作骨密度测定、Micro-CT检测及骨组织形态学分析。结果与B组相比，A组股骨骨密度明显降低（P〈0．05），证实OVX造模成功；体外成骨诱导培养的ASCs细胞计数与未诱导组相比，差异无统计学意义（P〉0．05），而ALP、OCN检测及茜素红染色证实ASCs已分化为成骨细胞；自体细胞移植治疗12周后，与对照组相比，细胞治疗组股骨远端骨密度、骨小梁数量、厚度、分离度及结构模型指数均明显改善（P〈0．05）。组织学检测发现实验组骨小梁厚度增宽，植入的CAH材料已降解完全，而对照组骨小梁较纤细，CAH材料有部分残留。结论ASCs自体移植对兔OP有一定的治疗效果，为OP治疗提供新思路。

Objective To observe the effects of transplantation of autologous adipose-derived stem cells (ASCs) on osteoporosis (OP) in a rabbit ovariectomy (OVX) model.Methods A total of fifteen 6-month-old female New Zealand white rabbits were randomly divided into two groups:ovariectomy group (group A,n =12) and sham operation group (group B,n =3).All rabbits were subjected to bilateral ovariectomy in the group A.Six months later,bone mineral density (BMD) of group A and group B were measured by dual energy X-ray absorptiometry (DXA) to check the result of OVX-OP.ASCs harvested from adipose of OP rabbits were cultured to be expanded and differentiated in osteogenic medium in vitro.Osteogenesis was evaluated by alizarin red staining,alkaline phosphatase (ALP) staining and quantitative assays of osteocalcin (OCN).Autologous osteo-induced ASCs were mixed in calcium alginate hydrogel (CAH) and then transplanted in the left distal femurs,while CAH was transplanted in the right distal femurs of OP rabbits.At 12 weeks after implantation,BMD,micro-CT and histomorphological analyses were performed on these rabbits.Results The BMD of femurs in group A rabbits were obviously lower than that of group B rabbits (P ＜ 0.05) at 6 months after OVX.Compared with control group,ASCs cultured in osteo-induction medium had similar proliferation rate as the non-induced cells,but displayed positive ALP and alizarin red staining and OCN contents.At 12 weeks after implantation,the cell-treated femurs displayed higher BMD,bone trabecula number,trabecula thickness and separation than those of control group,while the structure model index and porosity were lower (P ＜ 0.05).Histological examination indicated that the trabecular thickness increased with complete CAH resorption in cell-treated group,while CAH remained in control group.Conclusions Transplantation of autologous ASCs can help strengthen osteoporotic bone in OVX-OP rabbits,providing a novel approach to OP treatment.