Evaluation Of Mesenchymal Stem Cells From Rat Femoral Head Necrosis Induced By Glucocorticoid

BACKGROUND:Femoral head necrosis is a disease that is commonly encountered in orthopedics.The main causes of femoral head necrosis are the usage of glucocorticoid, alcohol abuse,hemoglobinopathy, and decompression sickness. Today, femoral head necrosis inducedby glucocorticoid is of predominance in the non-traumatic femoral head necrosis. Inclinical practice, glucocorticoid is used to treat systemic lupus eythematosus(SLE),bechet’s disease, nephritic syndrome, pregnancy complications and so on. The featuresof these disease are the different degree of manifestation of vasculitis. These patients iseasy to become femoral head necrosis. Several orthopedists try to use autoallergicmesenchyme stem cells to treat femoral head necrosis. This method is inducing themultipotent mesenchyme stem cells to differentiate to the osteoblasts and vascularendothelial cell. The foundation of this treatment is the biology characteristic of thenormal bone marrow. The former studies laid particular emphasis on the imaginemanifestations, the changes of the pathology and the changes of hematology of thefemoral head necrosis. But the research of the biology of the mesenchyme stem cells isless and insufficient. It’s not clear whether the characters of autoallergic mesenchymestem cells, the component and percentage of the extracellular matrix is changed. And itis not clear whether the mesenchyme stem cells are suitable for treating the femoralhead necrosis.Method:(1) BSA and hormone are used to create the model of ONFH. Twenty SD rats(weight250g-280g) were divided into experimental group and control group randomly.In the experimental group, BSA (10ml/kg) was injected into the abdomen of the animalsonce a week for2times. After two weeks, methylprednisolone (40ml/kg) was injectedinto the muscle for three days. In contrast, physiological saline (10ml/kg) was injectedinto the abdomen of the rats in the control group.(2) All animals were sacrificed at twoweeks after injection, the femoral heads were harvested, fixed in4%paraformaldehyde (pH7.4) for48h at4°C, embedded in paraffin, sectioned, stained with HE and finallythe microstructure of bone and nucleus were observed.(3) Evaluation of the biologicalcharacteristics of bone marrow derived mesenchymal stem cell:①Proliferation of theBMSC;②The osteogenesis ability and adipocyte differentiation.Results:(1) Compared with the control group, the bone tissue was mostly replaced by theadipose tissue. In addition, the bone trabecula became loosen and ranked disorderly.Plenty of adipose cells assembled and and became large. Furthermore, some bonetrabecula was observed atrophy and slender.(2) Detection of cell proliferation at theseventh day, the result of ALP stain demonstrated the amount of alkalinephosphatase was significantly less than was in the control group，but alizarin redstaining show the number of calcium nodules wass significantly less than control group.After adipocety inducing,the number of adipogenic cells wass less than control group.Conclution：(1) The model of steroid-induced ONFH can be established by combining bovineserum with high-dosage methylprednisolone；(2) Bone marrow mesenchymal stem cellsof model group still have the biological characteristics of stem cells. But compared withthe control group，the bone marrow mesenchymal stem cells of model group in vitroproliferation and the ability of bone and adipose induction were reduced in varyingdegree.