Steroid-induced osteonecrosis of femoral head (SONFH) is a disease characterized by femoral head collapse and local pain caused by excessive use of glucocorticoids. Peroxisome proliferator-activated receptor-γ (PPARγ) is mainly expressed in adipose tissue. Wnt/β-catenin, AMPK and other related signaling pathways play an important role in regulating adipocyte differentiation, fatty acid uptake and storage. Bone marrow mesenchymal cells (BMSCs) have the ability to differentiate into adipocytes or osteoblasts, and the use of hormones upregulates PPARγ expression, resulting in BMSCs biased towards adipogenic differentiation. The increase of adipocytes affects the blood supply and metabolism of the femoral head, and the decrease of osteoblasts leads to the loss of trabecular bone, which eventually leads to partial or total ischemic necrosis and collapse of the femoral head. MicroRNAs (miRNAs) are a class of short non-coding RNAs that regulate gene expression by inhibiting the transcription or translation of target genes, thereby affecting cell function and disease progression. Studies have shown that miRNAs affect the progression of SONFH by regulating PPARγ lipid metabolism-related signaling pathways. Therefore, it may be an accurate and feasible SONFH treatment strategy to regulate adipogenic-osteoblast differentiation in BMSCs by targeted intervention of miRNA differential expression to improve lipid metabolism. In this paper, the miRNA-mediated PPARγ-related signaling pathways were classified and summarized to clarify their effects on lipid metabolism in SONFH, providing a theoretical reference for miRNA targeted therapy of SONFH, and then providing scientific evidence for SONFH precision medicine.
MicroRNAs/physiology* ; PPAR gamma/metabolism* ; Femur Head Necrosis/metabolism* ; Humans ; Signal Transduction/physiology* ; Lipid Metabolism/physiology* ; Animals ; Cell Differentiation ; Mesenchymal Stem Cells/cytology* ; Glucocorticoids/adverse effects*

This study aims to investigate the pharmacological effects and mechanisms of Yougui Yin in treating glucocorticoid-induced osteonecrosis. A rat model of glucocorticoid-associated osteonecrosis of the femoral head(GA-ONFH) was established by intramuscular injection of dexamethasone at 20 mg·kg~(-1) every other day for 8 weeks. Rats were randomly allocated into control, model, and low-and high-dose(1.5 and 3.0 g·kg~(-1), respectively) Yougui Yin groups. After modeling, rats in Yougui Yin groups were administrated with Yougui Yin via gavage, which was followed by femoral specimen collection. Hematoxylin-eosin staining was employed to observe femoral head repair, and immunofluorescence was employed to assess adipogenic differentiation of bone marrow mesenchymal stem cells(BMSCs) within the femoral head. Cell experiments were carried out with dexamethasone(1 μmol·L~(-1))-treated BMSCs to evaluate the effects of Yougui Yin-medicated serum on adipogenic differentiation. Animal experiments demonstrated that compared with the model group, Yougui Yin at both high and low doses significantly improved bone mineral density(BMD), bone volume/total volume(BV/TV) ratio, and trabecular thickness(Tb.Th) in the femoral head. Additionally, Yougui Yin alleviated necrosis-like changes and adipocyte infiltration and significantly reduced the expression level of peroxisome proliferator-activated receptor γ(PPARγ) in the femoral head, thereby suppressing the adipogenic differentiation of BMSCs in GA-ONFH rats. The cell experiments revealed that Yougui Yin-medicated serum markedly inhibited dexamethasone-induced adipogenic differentiation of BMSCs and down-regulated the level of PPARγ. The overexpression of PPARγ attenuated the inhibitory effect of Yougui Yin-medicated serum on the adipogenic differentiation of BMSCs, indicating the critical role of PPARγ in Yougui Yin-mediated suppression of adipogenic differentiation of BMSCs. In conclusion, Yougui Yin exerts therapeutic effects on glucocorticoid-induced osteonecrosis by down-regulating PPARγ expression and inhibiting adipogenic differentiation of BMSCs.
Animals ; Mesenchymal Stem Cells/metabolism* ; PPAR gamma/genetics* ; Rats ; Drugs, Chinese Herbal/administration & dosage* ; Male ; Glucocorticoids/adverse effects* ; Rats, Sprague-Dawley ; Adipogenesis/drug effects* ; Osteonecrosis/genetics* ; Cell Differentiation/drug effects* ; Bone Marrow Cells/metabolism* ; Femur Head Necrosis/chemically induced* ; Humans

Steroid-induced osteonecrosis of the femoral head (SONFH) is avascular necrosis of the femoral head caused by long-erm use of corticosteroids, and its pathogenesis is complex and affected by changes in the dynamic balance of the bone microenvironment. With the deepening of research, the role of bone microenvironment in the pathogenesis of SONFH has been gradually revealed. In the case of excessive use of glucocorticoids (GCs), the bone microenvironment changes significantly, causing imbalance in bone lipid metabolism, microcirculation disorders and disorders of immune regulation, which promotes the increase of the number and activity of osteoclasts, and interferes with the differentiation of osteoblasts and adipoblasts. Through the regulation of PI3K/AKT, OPG/RANKL/RANK, MAPK, JAK/STAT, Hedgehog and other signaling pathways, it eventually leads to osteocyte apoptosis, bone microvascular rupture and destruction of trabecular bone structure, which in turn leads to osteonecrosis, bone density reduction and bone microstructure destruction due to bone microcirculation ischemia, and finally leads to necrosis of the femoral head. This article reviews the role of bone microenvironment homeostasis in GCs-induced ONFH and the regulatory mechanism of bone microenvironment, which is helpful to reveal the pathogenesis of SONFH and provide a theoretical basis for exploring effective intervention strategies.
Humans ; Femur Head Necrosis/physiopathology* ; Animals ; Signal Transduction ; Bone and Bones/metabolism* ; Glucocorticoids/adverse effects* ; Cellular Microenvironment

OBJECTIVESTo observe the regulation of Chinese herbal medicine, Modifified Qing'e Pill (, MQEP), on the expression of adiponectin, bone morphogenetic protein 2 (BMP2), osteoprotegerin (OPG) and other potentially relevant risk factors in patients with nontraumatic osteonecrosis of the femoral head (ONFH).

METHODSA total of 96 patients with nontraumatic ONFH were unequal randomly divided into treatment group (60 cases) and control group (36 cases). The treatment group were treated with MQEP while the control group were treated with simulated pills. Both groups were given caltrate D. Six months were taken as a treatment course. Patients were followed up every 2 months. The levels of plasma adiponectin, BMP2, OPG, von Willebrand factor (vWF), von Willebrand factor cleaving protease (vWF-cp), plasminogen activator inhibitor 1 (PAI-1), tissue plasminogen activator (tPA), C-reactive protein (CRP), blood rheology, bone mineral density (BMD) of the femoral head and Harris Hip Score were measured before and after treatment.

RESULTSAfter 6 months of treatment, compared with the control group, patients in the treatment group had signifificantly higher adiponectin and BMP2 levels (P<0.01 and P=0.013, respectively), lower vWF, PAI-1 and CRP levels (P=0.019, P<0.01 and P<0.01, respectively), and lower blood rheology parameters. BMD of the femoral neck, triangle area and Harris Hip Score in the treatment group were signifificantly higher than those in the control group. Moreover, plasma adiponectin showed a positive association with BMP2 (r=0.231, P=0.003) and a negative association with PAI-1 (r=-0.159, P<0.05).

CONCLUSIONMQEP may play a protective role against nontraumatic ONFH by increasing the expression of adiponectin, regulating bone metabolism and improving the hypercoagulation state, which may provide an experimental base for its clinical effects.

Adiponectin ; metabolism ; Adult ; Blood Coagulation Factors ; metabolism ; Bone Density ; drug effects ; Bone Morphogenetic Protein 2 ; metabolism ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Female ; Femur Head Necrosis ; blood ; drug therapy ; physiopathology ; Humans ; Male

PURPOSE: To explore the value of transplanting peripheral blood-derived mesenchymal stem cells from allogenic rabbits (rPBMSCs) to treat osteonecrosis of the femoral head (ONFH). MATERIALS AND METHODS: rPBMSCs were separated/cultured from peripheral blood after granulocyte colony-stimulating factor mobilization. Afterwards, mobilized rPBMSCs from a second passage labeled with PKH26 were transplanted into rabbit ONFH models, which were established by liquid nitrogen freezing, to observe the effect of rPBMSCs on ONFH repair. Then, the mRNA expressions of BMP-2 and PPAR-γ in the femoral head were assessed by RT-PCR. RESULTS: After mobilization, the cultured rPBMSCs expressed mesenchymal markers of CD90, CD44, CD29, and CD105, but failed to express CD45, CD14, and CD34. The colony forming efficiency of mobilized rPBMSCs ranged from 2.8 to 10.8 per million peripheral mononuclear cells. After local transplantation, survival of the engrafted cells reached at least 8 weeks. Therein, BMP-2 was up-regulated, while PPAR-γ mRNA was down-regulated. Additionally, bone density and bone trabeculae tended to increase gradually. CONCLUSION: We confirmed that local transplantation of rPBMSCs benefits ONFH treatment and that the beneficial effects are related to the up-regulation of BMP-2 expression and the down-regulation of PPAR-γ expression.
Animals ; Blood Cells/*cytology ; Bone Morphogenetic Protein 2/genetics ; *Cell- and Tissue-Based Therapy ; Femur Head Necrosis/metabolism/*pathology/*therapy ; Gene Expression Regulation ; *Mesenchymal Stem Cell Transplantation ; Mesenchymal Stromal Cells/*cytology ; Osteonecrosis/*pathology/*therapy ; PPAR gamma/genetics ; Rabbits ; Transplantation, Homologous

BACKGROUNDSystemic administration of bisphosphonates has shown promising results in the treatment of osteonecrosis of the femoral head (ONFH). However, few studies have evaluated the efficacy of local zoledronate (ZOL) administration in the treatment of ONFH. The purpose of this study was to investigate whether local administration of bisphosphonate-soaked hydroxyapatite (HA) could improve bone healing in an experimental rabbit model of ONFH.

METHODSThis experimental study was conducted between October 2014 and June 2015. Forty-five rabbits underwent simulated ONFH surgery. Immediately following surgery, they were divided into three groups: model (untreated, n = 15), HA (treated with HA alone, n = 15), and HA + ZOL (treated with HA soaked in a low-dose ZOL solution, n = 15). Histological, immunohistochemical, and quantitative analyses were performed to evaluate bone formation and resorption 2, 4, and 8 weeks after surgery.

RESULTSGross bone matrix and hematopoietic tissue formation were observed in the HA + ZOL group 4 weeks after surgery. The immunohistochemical staining intensities for 5-bromodeoxyuridine, runt-related transcription factor 2, osteocalcin, osteopontin, and osteoprotegerin were significantly higher in the HA + ZOL group than that in the model (P < 0.001, P< 0.001, P< 0.001, P< 0.001, and P = 0.018, respectively) and HA groups (P = 0.003, P = 0.049, P< 0.001, P = 0.020, and P = 0.019, respectively), whereas receptor activator of the nuclear factor-κB ligand staining intensity was significantly lower in the HA + ZOL group than that in the model and HA groups (P = 0.029 and P = 0.015, respectively) 4 weeks after surgery. No significant differences in bone formation or bone resorption marker expression were found between the three groups 2 or 8 weeks after surgery (P > 0.05).

CONCLUSIONSLocal administration of HA soaked in a low-dose ZOL solution increased new bone formation while inhibiting bone resorption in an animal model of ONFH, which might provide new evidence for joint-preserving surgery in the treatment of ONFH.

Animals ; Diphosphonates ; administration & dosage ; therapeutic use ; Durapatite ; administration & dosage ; therapeutic use ; Female ; Femur Head Necrosis ; drug therapy ; metabolism ; Imidazoles ; administration & dosage ; therapeutic use ; Immunohistochemistry ; Male

Appearance of proteomics technology can fleetly filt and reveal specificity biomarkers of disease, this will help to reveal the pathogenesis of femur head necrosis and help early diagnosis, find more effective methods and therapeutic targets. At present, they are hot spots that find out the occurred mechanism,related proteins of early diagnosis and early treatment and its functional identification; set up the early related database; optimize the protein extraction methods for research of femur head necrosis. This article reviews the application of study technology of related proteins of femur head necrosis on bone tissue, serum,related animal model,and in order to provide further research ideas.
Early Diagnosis ; Femur Head Necrosis ; diagnosis ; metabolism ; Humans ; Proteomics ; methods

PURPOSE: Pathologic changes in the growth plate remain unknown in Legg-Calve-Perthes (LCP) disease. Spontaneously hypertensive rats have proven to be a good model for studying LCP disease. This study investigated the histopathologic changes and the expression of vascular endothelial growth factor in the growth plate of spontaneously hypertensive rats (SHR). MATERIALS AND METHODS: Sixty SHR rats were divided into two groups: those showing osteonecrosis (SHR+n group: 32), and those showing normal ossification (SHR-n group: 28). Thirty Wister Kyoto rats served as a control. For histomorphological measurement, the length of each zone of the growth plate was measured. Cell kinetics was measured by 5-bromo-2'-deoxyuridin (BrdU) immunohistochemistry and transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) assays. Vascular endothelial growth factor (VEGF) immunohistochemistry was used to identify of expression of VEGF. RESULTS: The lengths of growth plates of the SHR+n group were significantly shorter in the initial growth period than those of the other groups. The lowest proliferative rate and the highest apoptosis rate were observed in the SHR+n group at the initial growth period. The expression of VEGF in the growth plate of the SHR group was lower than the control group, and it was lower in the SHR+n group than in the SHR-n group. CONCLUSION: The growth plate of the SHR+n group was found to be affected by disease process of ischemic necrosis of the femoral head, and this might explain the relative overgrowth of the greater trochanter in the later stages of LCP disease.
Animals ; Apoptosis ; Femur Head/metabolism/*pathology ; Femur Head Necrosis/metabolism/pathology ; Growth Plate/*cytology/metabolism ; Osteogenesis/physiology ; Rats ; Rats, Inbred SHR ; Rats, Sprague-Dawley ; Vascular Endothelial Growth Factor A/metabolism

OBJECTIVETo observe the effect of Huogu II formula compatible with different channel ushering drugs on the homing of bone marrow stem cells of osteonecrosis of the femoral head (ONFH) induced by liquid nitrogen freezing in rabbits and discuss the mechanism for preventing and treating ONFH.

METHODThe ONFH model was established by liquid nitrogen freezing of 84 rabbits. They were randomly assigned to the model group and the Huogu II formula group and groups of Huogu II formula combining with Achyranthis Bidentatae Radix, Asari Radix et Rhizoma, Angelicae Pubescentis Radix, Platycodonis Radix. The remaining 14 rabbits were sham-operated. During the course of ONFH modeling, all of the rabbits were subcutaneously injected with recombinant human granulocyte colony-stimulating factor (rhG-CSF)(30 microg x kg(-1) x d(-1), for consecutively 7 days). Meanwhile, normal saline and decoction of the formulae were orally administrated respectively. WBC was counted in peripheral blood before and after the injection of rhG-CSF. HE stainings at the 2nd and the 4th weeks after the modeling were adopted to observe histopathological changes, vascular morphology was observed by ink perfusion, BrdU and SDF-1 were determined by immunohistochemical assay in femoral heads of the left hind leg.

RESULTCompared with the sham-operated group, the Huogu II formula group showed decrease in the ratio of empty lacuna and increase in vessel area, number of BrdU positive cells and SDF-1 level. In comparison with the model group, the Achyranthis Bidentatae Radix group displayed decreasing empty lacuna ratio and increasing vessel area at the 4th week and increasing SDF-1 at the 2nd week; the Platycodonis Radix group revealed a notably increasing empty lacuna ratio and a sharp decrease in the number of BrdU positive cells at 4th week; Asari Radix et Rhizoma and Angelicae Dubescentis Radix groups showed no remarkable change.

CONCLUSIONHuogu II formula can promote the directional homing of bone marrow stem cell to the necrosis area. Channel ushering drug achyranthes can further boost above effects of Huogu II formula.

Animals ; Bone Marrow Cells ; cytology ; Bromodeoxyuridine ; metabolism ; Chemokine CXCL12 ; metabolism ; Disease Models, Animal ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Femur Head Necrosis ; blood ; drug therapy ; metabolism ; pathology ; Gene Expression Regulation ; drug effects ; Humans ; Leukocyte Count ; Male ; Rabbits ; Stem Cells ; cytology ; drug effects

OBJECTIVETo study the mechanism of Huogu I formula (I) in treating osteonecrosis of femoral head.

METHODSForty-eight healthy female Leghorn chickens were randomly divided into control group, model group and Huogu I group, and each group consisted of 16 chickens. At the meantime of model establishment, chickens of the Huogu I group were administrated with decoction, while the model and control group with distilled water by gavage. At the 8th and 16th week after medication, blood samples were obtained for blood lipid detection while both sides of femoral head were harvested for the rest of examinations. Specifically, expressions of bone morphogenetic protein-2 (BMP2), transforming growth factor beta1 (TGFβ(1)), Smad4 and Smad7 were evaluated by immunohistochemistry, while expression of osteoprotegerin/receptor activator of nuclear factor kappaB ligand (OPG/RANKL) mRNA was detected by in situ hybridization.

RESULTSCompared with the control group, serum levels of total cholesterol (TC), triglyceride (TG) and low-density lipoprotein cholesterol (LDL-C) in the model group rose significantly. Positive cell counting of BMP2, TGFβ(1), Smad4 and OPG in femoral head of the model group dropped prominently. Positive cell counting of Smad7 and RANKL increased dramatically. In contrast with the model group, levels of TC, TG and LDL-C in Huogu I group reduced significantly. Positive cell counting of BMP2, TGFβ(1), Smad4 and OPG in femoral head of the Huogu I group increased prominently. Indices of Smad7 and RANKL both decreased significantly. Especially at the 8th week, these variations were more significant.

CONCLUSIONHuogu I formula is effective in promoting repair of necrotic femoral head by regulating the expressions of BMP2, TGFβ(1), Smads and OPG/RANKL of osteoclast in femoral head.

Animals ; Bone Morphogenetic Protein 2 ; metabolism ; Bone Regeneration ; drug effects ; physiology ; Chickens ; Chondrocytes ; metabolism ; Disease Models, Animal ; Drugs, Chinese Herbal ; pharmacology ; Female ; Femur Head Necrosis ; chemically induced ; drug therapy ; metabolism ; Lipid Metabolism ; physiology ; Osteocytes ; metabolism ; Osteoprotegerin ; genetics ; metabolism ; Receptor Activator of Nuclear Factor-kappa B ; genetics ; metabolism ; Smad4 Protein ; metabolism ; Smad7 Protein ; metabolism ; Steroids ; pharmacology ; Transforming Growth Factor beta1 ; metabolism