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

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

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

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 regulation of Youguiyin (YGY, ) on the gene expression profile of the rat with steroid-induced femoral head necrosis (sFHN), for the sake of investigating its molecular mechanism of sFHN prevention and treatment.

METHODSAll the 30 rats were randomly divided into three groups, the normal control group (A), the model control group (B), and the YGY treated group (C), 10 in each group. After rats in Groups B and C were being made into FHN models with steroid injection, they received a daily intragastric administration of saline and YGY respectively in equal volume for a total of 6 weeks, while to the unmodeled normal rats in Group A, saline was administered instead. The rats were sacrificed at the terminal of administration; their mRNA from femoral head tissue was extracted and prepared to cDNA probe through inverse transcription for detecting gene expression profile by microarray, outcomes of which was passing fluorescence quantitative PCR verification, and the differential expressed genes were analyzed adopting gene ontology (GO) method.

RESULTSCompared with Group A, the numbers of differential genes found in Groups B and C were 190 and 92, respectively, but the changing trend in the two groups was opposite, mainly manifested as down-regulating in Group B/Group A (GB/GA) and up-regulating in Group C/Group B (GC/GB). The analysis showed that these differential genes were mainly assigned to cell apoptosis, signal transduction, metabolism, cell proliferation and differentiation, cell cycle, blood coagulation, antioxidant activity, etc.

CONCLUSIONSsFHN was regulated by various genes; the regulation of YGY on expressions of these genes and the intra/extra-cellular signaling processes was possibly the molecular mechanism of YGY for preventing/treating sFHN. This study gave an explanation to the effectiveness of Chinese medicine in preventing/treating FHN from aspects of gene expression and enriched the Chinese medicine theory of "Kidney (Shen) governing bones".

Animals ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Female ; Femur Head ; drug effects ; metabolism ; pathology ; Femur Head Necrosis ; chemically induced ; drug therapy ; genetics ; Gene Expression Profiling ; Male ; Rats ; Rats, Wistar ; Reproducibility of Results ; Reverse Transcriptase Polymerase Chain Reaction ; Steroids ; Treatment Outcome

OBJECTIVETo investigate the effect of Huogu II Formula (II) with medicinal guide Radix Achyranthis Bidentatae (Ach) on bone marrow stem cells (BMSCs) homing to necrosis area after osteonecrosis of the femoral head (ONFH) frozen by liquid nitrogen in rabbit as well as to explore the mechanism of prevention and treatment for ONFH.

METHODSThe animal model of ONFH was established by liquid nitrogen frozen on the rabbit left hind leg. Forty-eight Japanese White rabbits were randomly assigned to sham-operated group, model group, Huogu II group, and Huogu II plus Ach group, with 12 rabbits in each. During the course of ONFH animal model establishment, all rabbits were subcutaneously injected with recombinant human granulocyte colony-stimulating factor [rhG-CSF, 30 μg/(kg·day) for continuous 7 days]. Meanwhile, normal saline and decoction of the two formulae were administrated by gavage, respectively. White blood cells (WBC) were counted in peripheral blood before and after injection of rhG-CSF. Materials were drawn on the 2nd and 4th weeks after model built; bone glutamine protein (BGP) and bone morphogenetic protein 2 (BMP2) levels in serum were tested. Histopathologic changes were observed by hematoxylin and eosin (HE) staining. BMP2 mRNA levels were detected with in situ hybridization (ISH) staining. 5-Bromo-2'-deoxyuridine (BrdU) and stromal cell derived factor 1 (SDF-1) were measured by immunohistochemical assay in femoral head of the left hind leg.

RESULTSCompared with the shamoperated group, the ratio of empty lacuna, serum BGP, and SDF-1 level in the model group increased significantly, and BMP2 in both serum and femoral head decreased significantly. However, in comparison with the model group, the empty lacuna ratio of Huogu II group and Huogu II plus Ach group decreased obviously in addition to the levels of serum BGP and BMP2, and the expressions of BMP2 mRNA, BrdU, and SDF-1 increased significantly. Above changes were particularly obvious in Huogu II plus Ach group. BGP and SDF-1 on the 2nd week and empty lacuna rate and serum BMP2 level on the 4th week in Huogu II group significantly exceeded their counterparts. On the 2nd week, only in Huogu II plus Ach group that the BrdU counting rose significantly. On the 4th week, empty lacuna rate and serum BMP2 level in Huogu II plus Ach group exceeded those in Huogu II group distinctively.

CONCLUSIONSTo a certain extent, the medicinal guide Ach improves the preventive and therapeutic effects of Huogu II Formula on experimental ONFH model. The possible mechanism of this is related to its promoting effect on directional homing of BMSCs to the necrosis area.

Achyranthes ; Animals ; Bone Marrow Cells ; cytology ; drug effects ; Bone Morphogenetic Protein 2 ; blood ; genetics ; Bromodeoxyuridine ; metabolism ; Cell Movement ; Chemokine CXCL12 ; metabolism ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Enzyme-Linked Immunosorbent Assay ; Femur Head ; drug effects ; pathology ; Femur Head Necrosis ; blood ; genetics ; pathology ; therapy ; Gene Expression Regulation ; drug effects ; Granulocyte Colony-Stimulating Factor ; administration & dosage ; pharmacology ; Humans ; Leukocyte Count ; Male ; RNA, Messenger ; genetics ; metabolism ; Rabbits ; Radioimmunoassay ; Stem Cell Transplantation ; Stem Cells ; cytology ; drug effects