Lithium prevents glucocorticoid-induced osteonecrosis of the femoral head by regulating autophagy.

Autophagy may play an important role in the occurrence and development of glucocorticoid-induced osteonecrosis of the femoral head (GC-ONFH). Lithium is a classical autophagy regulator, and lithium can also activate osteogenic pathways, making it a highly promising therapeutic agent for GC-ONFH. We aimed to evaluate the potential therapeutic effect of lithium on GC-ONFH. For in vitro experiments, primary osteoblasts of rats were used for investigating the underlying mechanism of lithium's protective effect on GC-induced autophagy levels and osteogenic activity dysfunction. For in vivo experiments, a rat model of GC-ONFH was used for evaluating the therapeutic effect of oral lithium on GC-ONFH and underlying mechanism. Findings demonstrated that GC over-activated the autophagy of osteoblasts and reduced their osteogenic activity. Lithium reduced the over-activated autophagy of GC-treated osteoblasts through PI3K/AKT/mTOR signalling pathway and increased their osteogenic activity. Oral lithium reduced the osteonecrosis rates in a rat model of GC-ONFH, and restrained the increased expression of autophagy related proteins in bone tissues through PI3K/AKT/mTOR signalling pathway. In conclusion, lithium can restrain over-activated autophagy by activating PI3K/AKT/mTOR signalling pathway and up-regulate the expression of genes for bone formation both in GC induced osteoblasts and in a rat model of GC-ONFH. Lithium may be a promising therapeutic agent for GC-ONFH. However, the role of autophagy in the pathogenesis of GC-ONFH remains controversial. Studies are still needed to further explore the role of autophagy in the pathogenesis of GC-ONFH, and the efficacy of lithium in the treatment of GC-ONFH and its underlying mechanisms.

Analysis of the Potential Angiogenic Mechanisms of BuShenHuoXue Decoction against Osteonecrosis of the Femoral Head Based on Network Pharmacology and Experimental Validation.

OBJECTIVE: Osteonecrosis of the femoral head (ONFH) is a common orthopedic disease with a high disability rate. The clinical effect of BuShenHuoXue decoction (BSHX) for ONFH is satisfactory. We aimed to elucidate the potential angiogenic mechanisms of BSHX in a rat femoral osteonecrosis model and bone marrow mesenchymal stem cells (BMSCs). METHODS: With in vivo experiments, we established the steroid-induced osteonecrosis of the femoral head (SONFH) model using Sprague-Dawley (SD) rats (8-week-old). The rats were randomly divided into five group of 12 rats each and given the corresponding interventions: control, model (gavaged with 0.9% saline), BSHX low-, medium- and high-dose groups (0.132 3, 0.264 6, and 0.529 2 g/mL BSHX solution by gavage). After 12 weeks, haematoxylin and eosin (H&E) staining was preformed to evaluate rat osteonecrosis. the expression of angiogenic factors (CD31, VEGFA, KDR, VWF) in rat femoral head was detected by immunohistochemistry, qPCR and western blotting. In cell experiment, BMSCs were isolated and cultured in the femoral bone marrow cavity of 4-week-old SD rats. BMSCs were randomly divided into eight groups and intervened with different doses of BSHX-containing serum and glucocorticoids: control group (CG); BSHX low-, medium-, and high-dose groups (CG + 0.661 5, 1.323, and 2.646 g/kg BSHX gavage rat serum); dexamethasone (Dex) group; and Dex + BSHX low-, medium-, and high-dose groups (Dex + 0.661 5, 1.323, and 2.646 g/kg BSHX gavaged rat serum), the effects of BSHX-containing serum on the angiogenic capacity of BMSCs were examined by qPCR and Western blotting. A co-culture system of rat aortic endothelial cells (RAOECs) and BMSCs was then established. Migration and angiogenesis of RAOECs were observed using angiogenesis and transwell assay. Identification of potential targets of BSHX against ONFH was obtained using network pharmacology. RESULTS: BSHX upregulated the expression of CD31, VEGFA, KDR, and VWF in rat femoral head samples and BMSCs (p < 0.05, vs. control group or model group). Different concentrations of BSHX-containing serum significantly ameliorated the inhibition of CD31, VEGFA, KDR and VWF expression by high concentrations of Dex. BSHX-containing serum-induced BMSCs promoted the migration and angiogenesis of RAOECs, reversed to some extent the adverse effect of Dex on microangiogenesis in RAOECs, and increased the number of microangiogenic vessels. Furthermore, we identified VEGFA, COL1A1, COL3A1, and SPP1 as important targets of BSHX against ONFH. CONCLUSION: BSHX upregulated the expression of angiogenic factors in the femoral head tissue of ONFH model rats and promoted the angiogenic capacity of rat RAOECs and BMSCs. This study provides an important basis for the use of BSHX for ONFH prevention and treatment.

Erythropoietin suppresses osteoblast apoptosis and ameliorates steroid-induced necrosis of the femoral head in rats by inhibition of STAT1-caspase 3 signaling pathway.

BACKGROUND: Steroid-induced avascular necrosis of the femoral head (SANFH) is characterized by osteoblast apoptosis, leading to a loss of bone structure and impaired hip joint function. It has been demonstrated that erythropoietin (EPO) performs a number of biological roles. OBJECTIVE: We examined the effects of EPO on SANFH and its regulation of the STAT1-caspase 3 signaling pathway. METHOD: In vitro, osteoblasts were treated with dexamethasone (Dex) or EPO. We identified the cytotoxicity of EPO by CCK-8, the protein expression of P-STAT1, cleaved-caspase9, cleaved-caspase3, Bcl-2, BAX, and cytochrome c by Western blotting, and evaluated the apoptosis of osteoblasts by flow cytometry. In vivo, we analyzed the protective effect of EPO against SANFH by hematoxylin and eosin (H&E), Immunohistochemical staining, and Micro-computed tomography (CT). RESULTS: In vitro, EPO had no apparent toxic effect on osteoblasts. In Dex-stimulated cells, EPO therapy lowered the protein expression of BAX, cytochrome c, p-STAT1, cleaved-caspase9, and cleaved-caspase3 while increasing the expression of Bcl-2. EPO can alleviate the apoptosis induced by Dex. In vivo, EPO can lower the percentage of empty bone lacunae in SANFH rats. CONCLUSION: The present study shows that EPO conferred beneficial effects in rats with SANFH by inhibiting STAT1-caspase 3 signaling, suggesting that EPO may be developed as a treatment for SANFH.

Ursolic acid alleviates steroid-induced avascular necrosis of the femoral head in mouse by inhibiting apoptosis and rescuing osteogenic differentiation.

Steroid-induced avascular necrosis of femoral head (SANFH) is a common disorder worldwide with high disability. Overdose of glucocorticoid (GC) is the most common non-traumatic cause of SANFH. Up until now, there are limited therapeutic strategies for curing SANFH, and the mechanisms underlying SANFH progression remain unclear. Nevertheless, Osteogenic dysfunction is considered to be one of the crucial pathobiological mechanisms in the development of SANFH, which involves mouse bone marrow mesenchymal stem cells (BMSCs) apoptosis and osteogenic differentiation disorder. Ursolic acid (UA), an important component of the Chinese medicine formula Yougui Yin, has a wide range of pharmacological properties such as anti-tumor, anti-inflammatory and bone remodeling. Due to the positive effect of Yougui Yin on bone remodeling, the purpose of this study was to investigate the effects of UA on dexamethasone (DEX)-induced SANFH in vitro and vivo. In vitro, we demonstrated that UA can promote mouse BMSCs proliferation and resist DEX-induced apoptosis by CCK8, Western blotting, TUNEL and so on. In addition, vitro experiments such as ALP and Alizarin red staining assay showed that UA had a beneficial effect on the osteogenic differentiation of mouse BMSCs. In vivo, the results of H&E staining, immunohistochemistry staining, Elisa and micro-CT analysis showed that UA had a bone repair-promoting effect in SANFH model. Moreover, the results of Western blot and TUNEL experiments showed that UA could delay the disease progression of SANFH in mice by inhibiting apoptosis. Overall, our study suggests that UA is a potential compound for the treatment of SANFH.

Effects of astragaloside IV on glucocorticoid-induced avascular necrosis of the femoral head via regulating Akt-related pathways.

We investigated the role of astragaloside IV (AS-IV) in preventing glucocorticoid-induced avascular necrosis of the femoral head (ANFH) and the underlying molecular mechanisms. Network pharmacology was used to predict the molecular targets of AS-IV. Molecular dynamic simulations were performed to explore the binding mechanism and interaction mode between AS-IV and Akt. Rat models of glucocorticoid-induced ANFH with AS-IV intervention were established, and osteogenesis, angiogenesis, apoptosis and oxidative stress were evaluated before and after blocking the PI3K/Akt pathway with LY294002. The effects of glucocorticoid and AS-IV on bone marrow mesenchymal stem cells and human umbilical vein endothelial cells incubated with and without LY294002 were determined. Downregulated p-Akt expression could be detected in the femoral heads of glucocorticoid-induced ANFH patients and rats. AS-IV increased trabecular bone integrity and vessel density of the femoral head in the model rats. AS-IV increased Akt phosphorylation and upregulated osteogenesis-, angiogenesis-, apoptosis- and oxidative stress-related proteins and mRNA and downregulated Bax, cleaved caspase-3 and cytochrome c levels. AS-IV promoted human umbilical vein endothelial cell migration, proliferation and tube formation ability; bone marrow mesenchymal stem cell proliferation; and osteogenic differentiation under glucocorticoid influence. AS-IV inhibited apoptosis. LY294002 inhibited these effects. AS-IV prevented glucocorticoid-induced ANFH by promoting osteogenesis and angiogenesis via the Akt/Runx2 and Akt/HIF-1α/VEGF pathways, respectively, and suppressing apoptosis and oxidative stress via the Akt/Bad/Bcl-2 and Akt/Nrf2/HO-1 pathways, respectively.

Tongluo Shenggu capsule promotes angiogenesis to ameliorate glucocorticoid-induced femoral head necrosis via upregulating VEGF signaling pathway.

BACKGROUND: Tongluo Shenggu Capsule (TLSGC) is a product of Traditional Chinese patent medicine that has been effective in glucocorticoid-induced osteonecrosis of the femoral head (GIONFH) clinically for many years. It is made from water extracts of a well-used herbal and dietary supplement-pigeon pea leaves. Nevertheless, the material basis and pharmacological mechanisms of TLSGC ameliorating GIONFH needed to be better defined. PURPOSE: To investigate the material basis and pharmacological mechanisms of TLSGC to ameliorate GIONFH. METHODS: The chemical compositions in TLSGC were characterized using the LC-MS system. Based on integrating the relevant targets of TLSGC in MedChem Studio software and GIONFH-related genes in our previous work, a "drug targets-disease genes" interaction network was constructed. The candidate targets of TLSGC ameliorating GIONFH were filtrated by topological characteristic parameters and further experimental validated based on methylprednisolone-induced rat model and dexamethasone-inhibited human umbilical vein endothelial cells (HUVECs). RESULTS: A total of 33 chemical compositions were characterized in TLSGC. Based on these compositions and GIONFH-related genes, 122 hub genes were selected according to topological parameters calculation. Biological functions were mainly enriched in four over-expressed modules of vascular damage, inflammation and apoptosis, bone metabolism and energy metabolism. The hub genes had the maximum enrichment degree in the VEGF-VEGFR2-PKC-Raf1-MEK-ERK signaling axis of the VEGF pathway. Experimentally, the therapeutic effects of TLSGC against GIONFH in rats were proved by micro-CT and pathological examination. Then, the protective effects of TLSGC on vascular damage were determined using angiography, CD31 immunohistochemistry, vascular function indicators in vivo, aortic ring test ex vivo, and the HUVECs activities in vitro including migration, invasion and tube formation. Mechanically, TLSGC effectively suppressed the downregulation of VEGF and VEGFR2 and their downstream targets, including Raf-1, PKC, p-MEK, and p-ERK proteins both in vivo and in vitro. CONCLUSION: TLSGC could promote angiogenesis by upregulating the VEGF-VEGFR2-PKC-Raf-1-MEK-ERK signaling axis, thereby exerting an apparent curative effect on GIONFH.

Denosumab Can Prevent Collapse in Patients with Early-Stage Steroid-Induced Osteonecrosis of the Femoral Head by Inhibiting Osteoclasts and Autophagy.

OBJECTIVE: The osteoclastic bone resorption inhibitors might have positive effect in preventing femoral head collapse in patients with osteonecrosis of the femoral head (ONFH). However, as a novel osteoclastic inhibitor, whether denosumab can prevent collapse in steroid-induced ONFH remains unknown. This study aims to evaluate the treatment effect of denosumab and the potential protective mechanism. METHODS: This was a retrospective study. A total of 161 patients with steroid-induced ONFH who underwent denosumab treatment were reviewed, and 209 untreated patients were selected as controls. Their clinical characteristics and radiological exam results were obtained. Patients were treated with 60 mg denosumab every 6 months for 2 years. The primary outcome was the incidence of femoral head collapse at 2 years after the initial diagnosis of ONFH. Secondary outcomes included the Harris hip score, progression of osteosclerosis, increase in necrotic area, bone marrow oedema relief, and bone mineral density increase in the femoral head. The Mann-Whitney U test and chi-square tests were performed to identify the differences between the continuous and categorical variables, respectively. A multivariate logistic regression model was built to identify the factors associated with the treatment effect of denosumab. RESULTS: The incidence of femoral head collapse was 42.24% (68/161) in the denosumab group and 54.07% (113/209) in the control group (χ2  = 5.094, p = 0.024; relative risk = 0.787, 95% CI = 0.627-0.973). The excellent-good rates of the Harris hip score were 63.98% (103/161) in the denosumab group and 44.98% (94/209) in the control group (χ2  = 13.186, p < 0.001). The incidence of osteosclerosis progression in the denosumab group was 55.28% (89/161), which was significantly higher than that in the control group (43.54%, 91/209, χ2  = 5.016, p = 0.025). Meanwhile, a significant increase in bone mineral density was identified in 29.19% (47/161) and 7.18% (15/209) of patients in the denosumab and control groups, respectively (χ2  = 31.600, p < 0.001). The osteoclastic cytoplasm expression of LC3-II was more positive in the control group than in the denosumab group (immunohistochemistry scoring: 3.58 ± 2.27 vs 6.33 ± 2.64, Z = -2.684, p = 0.007). A total of three independent factors were considered to be associated with the positive treatment effect of denosumab, the time of first denosumab administration (OR = 2.010, 95% CI = 1.272-3.177), osteosclerosis (OR = 1.583, 95% CI = 1.024-2.445), and the necrotic area before denosumab administration (medium necrotic area: OR = 2.084, 95% CI = 1.245-3.487; large necrotic area: OR = 2.211, 95% CI = 1.255-3.893). CONCLUSIONS: The current study demonstrated that denosumab had a positive effect on preventing femoral head collapse in patients with steroid ONFH. This effect might be closely associated with the inhibition of osteoclasts and their autophagy.

The effects of thymoquinone on steroid-induced femoral head osteonecrosis: An experimental study in rats.

OBJECTIVES: In this study, we aimed to evaluate the antioxidant, anti-apoptotic, osteoblastic and hypolipidemic effects of thymoquinone (TQ) treatment on the steroid-induced osteonecrosis of femoral head (ONFH) model in rats. MATERIALS AND METHODS: A total of 24 rats were randomly divided into four groups: the control group administered saline; the TQ group administered 10 mg/kg/day TQ orally; lipopolysaccharide/methylprednisolone (LPS/MPS) group administered 20 µg/kg intraperitoneally LPS and 40 mg/kg intramuscularly MPS to establish ONFH model; and the LPS/ MPS+TQ group administered both LPS/MPS and, then, TQ once daily for four weeks. All rats were sacrificed after intracardiac blood collection and their right femurs were removed. RESULTS: Micro-computed tomography showed a higher bone mineral density and lower porosity, Tr. Sp and Tr. Sep data were detected in the LPS/MPS+TQ group. In histopathology, osteonecrosis increased significantly in the LPS/MPS group and osteonecrosis decreased in the LPS/MPS+TQ group compared to the LPS/MPS group (p=0.0077). Histomorphometric examination revealed that the percentage of BV/TV in the LPS/MPS group was significantly lower compared to control and other groups (p<0.01 and p<0.05, respectively), while it reached normal rates in the LPS/MPS+TQ group. Immunohistochemically, antioxidant, anti-apoptotic, and angiogenesis indicators (8-hydroxy-20- deoxyguanosine [8-OHdG], malondialdehyde [MDA], B-cell lymphoma [Bcl-2], caspase-3, vascular endothelial growth factor [VEGF]) were significantly improved in tissue and serum with TQ. Furthermore, TQ significantly reduced low- and high-density lipoprotein cholesterol ratio and carboxy-terminal type 1 collagen crosslink (CTX) in serum. CONCLUSION: Vascular and hematopoietic cell damages that occur due to steroid-induced deoxyribonucleic acid (DNA) oxidative and lipid peroxidative damages in an ONFH model can be successfully ameliorated by TQ administration. This antioxidant and anti-apoptotic effects of TQ may be a promising treatment option for early stage of osteonecrosis.

Ginkgo biloba L. extract prevents steroid-induced necrosis of the femoral head by rescuing apoptosis and dysfunction in vascular endothelial cells via the PI3K/AKT/eNOS pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Ginkgo biloba L. extract (EGb) is one of the world's most extensively used herbal medicines. Due to the diverse pharmacological properties of EGb, it has been used in the treatment of neurological illnesses, as well as cardiovascular and cerebrovascular ailments. However, the effect and pharmacological mechanism of EGb on steroid-induced necrosis of the femoral head (SINFH) are still unclear. AIM OF THE STUDY: SINFH remains a challenging problem in orthopedics. Previous investigations have shown that EGb has the potential to reduce the occurrence of SINFH. The goal was to determine the effect and mechanism of EGb in preventing SINFH by inhibiting apoptosis and improving vascular endothelial cells (VECs) functions. MATERIALS AND METHODS: CCK-8, nitric oxide (NO) production and flow cytometry were used to determine the cell apoptosis and function. The scratch and angiogenesis tests assessed migration and tube formation. Western blot analysis detected the expressions of apoptosis-related proteins and PI3K/AKT/eNOS pathway-related proteins. Apoptosis and angiogenesis were also detected treated with the inhibitors. A mouse model of SINFH was established. Paraffin section was used to determine the necrotic pathology and apoptosis. Vessels in the femoral heads were assessed by immunofluorescence staining. RESULTS: When stimulated by methylprednisolone (MPS), cell viability, NO generation and tube formation were decreased, the apoptotic rate increased. Simultaneously, MPS decreased the expression levels of p-PI3K, p-AKT, and p-eNOS. EGb increased the expression levels of these proteins, restrained apoptosis, and restored cell functions. The addition of the inhibitors decreased anti-apoptotic effect and angiogenesis. In addition, when compared to the model mice, there were fewer empty lacunae and normal trabecular arrangement after taking different doses of EGb. The protective effect was also confirmed by the vascular quantitative analysis in vivo. CONCLUSION: This study established that EGb increased endothelial cell activity and inhibited apoptosis and function loss induced by MPS, elucidating the effect and molecular mechanism of EGb on early SINFH.

An injectable hydroxypropyl-ß-cyclodextrin cross-linked gelatin-based hydrogel loaded bone mesenchymal stem cell for osteogenic and in vivo bone regeneration of femoral head necrosis.

An injectable hydroxypropyl-ß-cyclodextrin (HPßCD) cross-linking of gelatin (Gel) based hydrogel was embedded with BMSC in vivo bone regeneration of femoral head necrosis. This HPßCD-Gel hydrogel possesses quick gelation within 6 min; a high-water uptake resulted in faster biodegradation, high swelling, and a 3D porous network that strengthened its mechanical, surface, and morphological properties. The results indicated that BMSC showed high cell viability (>90%) during measurement; HPßCD-Gel hydrogels induced BMSC differentiation into osteocytes within 14 days more efficiently than the osteogenic medium. The HPßCD-Gel/BMSC hydrogels that were injected into the necrosis site of the femoral head in the vessels were measured for 2 weeks. In addition, the vessel density and mean vessel diameters increased in the next 2-8 weeks followed by increased new bone formation, according to the in vivo analysis. Overall, our findings show that this method is a promising strategy for improving femoral head necrosis bone regeneration.

A Network Pharmacology and Molecular Docking Strategy to Explore Potential Targets and Mechanisms Underlying the Effect of Curcumin on Osteonecrosis of the Femoral Head in Systemic Lupus Erythematosus.

BACKGROUND: Systemic lupus erythematosus (SLE) is a refractory immune disease, which is often complicated with osteonecrosis of the femoral head (ONFH). Curcumin, the most active ingredient of Curcuma longa with a variety of biological activities, has wide effects on the body system. The study is aimed at exploring the potential therapeutic targets underlying the effect of curcumin on SLE-ONFH by utilizing a network pharmacology approach and molecular docking strategy. METHODS: Curcumin and its drug targets were identified using network analysis. First, the Swiss target prediction, GeneCards, and OMIM databases were mined for information relevant to the prediction of curcumin targets and SLE-ONFH-related targets. Second, the curcumin target gene, SLE-ONFH shared gene, and curcumin-SLE-ONFH target gene networks were created in Cytoscape software followed by collecting the candidate targets of each component by R software. Third, the targets and enriched pathways were examined by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. Eventually, a gene-pathway network was constructed and visualized by Cytoscape software; key potential central targets were verified and checked by molecular docking and literature review. RESULTS: 201 potential targets of curcumin and 170 related targets involved in SLE-ONFH were subjected to network analysis, and the 36 intersection targets indicated the potential targets of curcumin for the treatment of SLE-ONFH. Additionally, for getting more comprehensive and accurate candidate genes, the 36 potential targets were determined to be analyzed by network topology and 285 candidate genes were obtained finally. The top 20 biological processes, cellular components, and molecular functions were identified, when corrected by a P value ≤ 0.05. 20 related signaling pathways were identified by KEGG analysis, when corrected according to a Bonferroni P value ≤ 0.05. Molecular docking showed that the top three genes (TP53, IL6, VEGFA) have good binding force with curcumin; combined with literature review, some other genes such as TNF, CCND1, CASP3, and MMP9 were also identified. CONCLUSION: The present study explored the potential targets and signaling pathways of curcumin against SLE-ONFH, which could provide a better understanding of its effects in terms of regulating cell cycle, angiogenesis, immunosuppression, inflammation, and bone destruction.

Astragalus polysaccharide ameliorates steroid-induced osteonecrosis of femoral head through miR-206/HIF-1α/BNIP3 axis.

Declining autophagy and rising apoptosis are the main factors driving the development of steroid-induced osteonecrosis of the femoral head (SONFH). Here, we showed that astragalus polysaccharide (APS) improved femoral head necrosis via regulation of cell autophagy and apoptosis through microRNA (miR)-206/hypoxia inducible factor-1 (HIF-1α)/BCL2 interacting protein 3 (BNIP3) axis. The expression of miR-206, HIF-1α, and BNIP3 in SONFH specimens and cell model were measured using qPCR. SONFH cell model was treated with APS. Cell autophagy was evaluated using LC3-immunofluorescence assays. Flow cytometry was conducted to assess cell apoptosis. Apoptosis-related proteins and autophagy-related proteins were determined using western blot. Besides, dual-luciferase reporter assay was employed to investigate the relationship between miR-206 and HIF-1α. Here we showed that miR-206 expression was upregulated in SONFH tissues and cell model. APS promoted autophagy and inhibited apoptosis in SONFH cell model via downregulating miR-206. What is more, HIF-1α was the target of miR-206. Knockdown of HIF-1α reversed the recovery effect of miR-206 inhibitor on SONFH cell model. Furthermore, BNIP3 was the target of HIF-1α. HIF-1α overexpression promoted autophagy and inhibited apoptosis, and knockdown of BNIP3 abolished the recovery effect of HIF-1α overexpression in SONFH cell model. These results provided evidence that APS reduced miR-206 expression, and the downregulated miR-206 increased BNIP3 expression by targeting HIF-1α to promote autophagy and inhibit bone cell apoptosis. Our research proved that APS effectively improved SONFH by regulating cell autophagy and apoptosis.

Lithium chloride prevents glucocorticoid-induced osteonecrosis of femoral heads and strengthens mesenchymal stem cell activity in rats.

BACKGROUND: Accumulating evidence suggests that lithium influences mesenchymal stem cell (MSC) proliferation and osteogenic differentiation. As decreased bone formation in femoral heads is induced by glucocorticoids (GCs), we hypothesized that lithium has a protective effect on GC-induced osteonecrosis of femoral heads (ONFH). METHODS: A rat ONFH model was induced by methylprednisolone (MP) and the effect of lithium chloride on the models was evaluated. Micro-computed tomography (CT)-based angiography and bone scanning were performed to analyze the vessels and bone structure in the femoral heads. Hematoxylin and eosin and immunohistochemical staining were performed to evaluate the trabecular structure and osteocalcin (OCN) expression, respectively. Bone marrow-derived MSCs were isolated from the models, and their proliferative and osteogenic ability was evaluated. Western blotting and quantitative real-time polymerase chain reaction were performed to detect osteogenic-related proteins including Runx2, alkaline phosphatase, and Collagen I. RESULTS: Micro-CT analysis showed a high degree of osteonecrotic changes in the rats that received only MP injection. Treatment with lithium reduced this significantly in rats that received lithium (MP + Li group); while 18/20 of the femoral heads in the MP showed severe osteonecrosis, only 5/20 in the MP + Li showed mild osteonecrotic changes. The MP + Li group also displayed a higher vessel volume than the MP group (0.2193 mm3vs. 0.0811 mm3, P < 0.05), shown by micro-CT-based angiography. Furthermore, histological analysis showed better trabecular structures and more OCN expression in the femoral heads of the MP + Li group compared with the MP group. The ex vivo investigation indicated higher proliferative and osteogenic ability and upregulated osteogenic-related proteins in MSCs extracted from rats in the MP + Li group than that in the MP group. CONCLUSIONS: We concluded that lithium chloride has a significant protective effect on GC-induced ONFH in rats and that lithium also enhances MSC proliferation and osteogenic differentiation in rats after GC administration.

Astragaloside IV ameliorates steroid-induced osteonecrosis of the femoral head by repolarizing the phenotype of pro-inflammatory macrophages.

Osteonecrosis of the femoral head (ON-FH) is a common complication of steroid use. Pro-inflammatory macrophages play a crucial role in the apoptosis of osteocytes. The objective of the study was to evaluate a plant extract astragaloside IV (AS-IV) in treating ON-FN. Bone-marrow-derived macrophages (BMDMs) were treated with lipopolysaccharides (LPS), IFN-γ or IL-4 to induce M1 and M2-like phenotypes. Quantitative real-time PCR and Western blot were used to examine M1 and M2 phenotypic markers. Flow cytometry was used to analyze MHC II, CD206, F4/80, and CD11b levels and cell apoptosis. Glucocorticoid was used to induce ON-FN in mice. TNF-α and IL-1ß levels in femoral head were determined using enzyme-linked immunosorbent assay. AS-IV repolarized macrophages from M1 to M2 phenotypes. Culture medium from AS-IV treated M1 macrophages induced less cell apoptosis osteocytes compared to that from untreated M1 macrophages. In ON-FH mice, the ratio of M1 macrophages was decreased in the femoral head by AS-IV, concomitant with a decrease in TNF-α and IL-1ß levels. AS-IV is effective in alleviating ON-FH through its effects in repolarizing macrophages from M1-like phenotype to M2-like phenotype, promoting survival of osteocytes, reducing arthritic symptoms, and decreasing inflammatory cytokines.

Identification of key non-coding RNAs and transcription factors regulators and their potential drugs for steroid-induced femoral head necrosis.

Steroid-induced necrosis of femoral head (SINFH) is a femoral head necrotic disease caused by prolonged use of hormones. The detailed pathogenesis has not been fully demonstrated. In this study, we employed the bioinformatics approach to probe the roles of SINFH inhibitors. Core dysfunction modules related to SINFH was obtained. Meanwhile, GO and KEGG analysis of genes in dysfunction modules are carried out. Furthermore, the pivot prediction analysis of dysfunction modules related to ncRNA and transcription factor (TF) has been performed. The functions of the enriched modules were focused on multiple perspectives, including circulation, gland development, bone development and reconstruction, calcium production, and fatty acid metabolism regulation. The ncRNAs and TFs analysis showed that miR-322-5p, miR-124-3p, miR-125a-3p, and Ctnnb1 were important members of SINFH dysfunction. Drug targets suggested that Zinc and adenosine monophosphate may have an impact on SINFH dysfunction. SINFH was closely related to bone development and reconstruction.

Preliminary study of icariin indicating prevention of steroid-induced osteonecrosis of femoral head by regulating abnormal expression of miRNA-335 and protecting the functions of bone microvascular endothelial cells in rats.

BACKGROUND: The pathogenesis of osteonecrosis of the femoral head (ONFH) is unclear. Our previous study demonstrated that upregulated miR-335 in bone microvascular endothelial cells (BMECs) might be associated with the disease of steroid-induced ONFH. Here, we study the preventive effect of ICA on steroid-induced ONFH in rats. METHOD: 90 rats were separated into three groups: control group, methylprednisolone (MPS) group, and MPS + Icariin (ICA) group. Four weeks later, histological analyses were performed. Thrombomodulin (TM) and vascular endothelial growth factor (VEGF) were tested. MiRNA-335 expression was screened in the three groups using Agilent Gene Spring GX software. Target genes of miRNA-335 were detected by bioinformatics analysis. The functions of BMECs were analyzed by scratch, angiogenesis and cell survival rate. RESULTS: ICA can prevent the occurrence of steroid-associated ONFH in rats and reduce the amount of TM and VEGF in serum induced by glucocorticoids. ICA could regulate the overexpression of miRNA-335 induced by glucocorticoids. We predicted the Gene ontology (GO) and signaling pathways of target genes. At 24 hours, we found that ICA significantly promoted BMECs migration abilities. We also found that ICA could promote the angioplasty ability of BMECs. ICA could improve the survival rate of BMECs after steroid-induced injury. CONCLUSIONS: ICA is effective to prevent the occurrence of steroidinduced ONFH. ICA has a protective effect against steroid-induced BMECs injury. ICA regulated the imbalance of miRNA-335 expression induced by the glucocorticoid in BMECs, which provides a new viewpoint to explore the mechanism of ICA in preventing steroid-induced ONFH.

Phosphodiesterase-5 inhibition improves bone regeneration at the early stages of ischemic osteonecrosis of the femoral head in rats.

Posttraumatic osteonecrosis of the femoral head (ONFH) affects patients at different ages and may lead to functional limitation and joint replacement, with total hip arthroplasty, which is a costly procedure. Proposed methods to optimize ischemic tissue regeneration have been reported. Phosphodiesterase-5 inhibitors act by inhibiting the degradation of guanosine 3',5'-cyclic monophosphate in the nitric oxide pathway, increasing its bioavailability and promoting vascular endothelial growth factor (VEGF)-mediated neovascular recruitment and the induction of tissue regeneration in the traumatized bone. Thirty male Sprague-Dawley rats (6 months old) were subjected to an experimental model of traumatic ONFH divided into two groups, according to the administration of 5 mg/kg sildenafil or water (control group). Rats were then killed at 7, 14, and 21 days. Histological (Goldner's trichrome), histochemical (periodic acid-Schiff [PAS]), and immunohistochemical (VEGF and osteopontin [OPN]) techniques were used to quantify bone and vascular responses. Higher levels of VEGF (p < 0.01) and OPN (p < 0.01) immunostaining in the epiphysis, the greater formation of osteoid tissue (p < 0.01 on Day 7; p < 0.05 on Day 14), and higher levels of PAS staining (p < 0.01 on Day 7) were observed in the sildenafil-treated group. The present study demonstrated that sildenafil optimized bone tissue regeneration by increasing VEGF signaling and OPN expression, with increased bone formation (osteoid and carbohydrate macromolecule deposition) in the early stages following traumatic ischemic insult. Thus, sildenafil treatment may improve the prognosis of patients with osteonecrosis.

Glucocorticoids decreased Cx43 expression in osteonecrosis of femoral head: The effect on proliferation and osteogenic differentiation of rat BMSCs.

Glucocorticoid (GC)-induced osteonecrosis of the femoral head (GC-ONFH) is considered as one of the most serious side effects of long-term or over-dose steroid therapy. However, the underlying cause mechanisms are still not fully investigated. We firstly established a rat model of GC-ONFH and injected lipopolysaccharide (LPS) and methylprednisolone (MPS). We found that the expressions of Cx43, Runx2, ALP and COLⅠ were more decreased than the normal group. Secondly, the isolated rat bone marrow stem cells (BMSCs) were treated with dexamethasone (Dex) in vitro, and the expressions of Cx43, Runx2, ALP and COLⅠ were decreased significantly. Moreover, the results of immunofluorescence staining, alizarin red staining, EdU assay and CCK8 showed that the osteogenic differentiation and the proliferation capacity of BMSCs were decreased after induced by Dex. A plasmid of lentivirus-mediated Cx43 (Lv-Cx43) gene overexpression was established to investigate the function of Cx43 in BMSCs under the Dex treatment. Findings demonstrated that the proliferation and osteogenic differentiation abilities were enhanced after Lv-Cx43 transfected to BMSCs, and these beneficial effects of Lv-Cx43 were significantly blocked when PD988059 (an inhibitor of ERK1/2) was used. In conclusion, the overexpression of Cx43 could promote the proliferation and osteogenic differentiation of BMSCs via activating the ERK1/2 signalling pathway, which provide a basic evidence for further study on the detailed function of Cx43 in GC-ONFH.

Current Treatment Modalities for Osteonecrosis of Femoral Head in Mainland China: A Cross-Sectional Study.

OBJECTIVE: To investigate the application of treatment modalities for patients with osteonecrosis of the femoral head (ONFH) in mainland China. METHODS: This cross-sectional study was based on the online application of China Osteonecrosis of the Femoral Head Database (CONFHD). Between July 2016 to December 2018, the CONFHD program planned to recruit ONFH patients from 12 administrative areas across mainland China. Real-world medical records of treatment regimens for these patients, including surgeries and prescriptions, were approved to upload to the CONFHD application for further analysis. The surgeries performed on these patients were classified into total hip arthroplasty and hip-preserving procedures, and the latter was further classified into core decompression, bone grafting, and tantalum rod implantation. Prescription medications were classified into chemical medicine and Chinese herbal medicine (CHM); chemical medicine was further classified according to their chemical compounds, and CHM was classified according to therapeutic functions based on traditional Chinese medicine theory. Descriptive analysis was performed to summarize the application of different treatment regimens on the overall sample. RESULTS: A total of 1491 patients (2381 hips) who fulfilled the protocol criteria were included. There were 1039 males and 452 females with a mean age of 47.29 ± 12.69 years. The causes of ONFH were alcoholism in 642 patients (43%), corticosteroid in 439 patients (29%), trauma in 239 patients (16%), and idiopathic ONFH in 171 patients (11%). Operative treatments (including total hip arthroplasty and hip-preserving procedures) were performed on 49% of patients (43% of hips), chemical medicine therapy (including bisphosphonate, statins, and prostacyclin) was given to 37% of patients (37% of hips), and CHM was administrated to 72% of patients (75% of hips). The aforementioned interventions were not always used alone, since 47% of patients (52% of hips) received combined regimens with multiple interventions. Among hips treated by surgery, all hips with ARCO stage IV ONFH received THA (305 hips), and THA was also performed on 63 hips with stage II ONFH. Over half of hips with stage I (81%), II (91%), and III (92%) ONFH had received pharmacological treatments. Prostacyclin and bisphosphonate were the top two most prescribed medicines used alone. CHM therapies with multiple CHM functions were more commonly prescribed. CONCLUSION: Current treatment modalities for ONFH patients in mainland China include operative treatment, chemical medicine, and CHM. Combined regimens with different treatment modalities are common in real-world clinical practices.

Combined Pharmacotherapy with Alendronate and Desferoxamine Regulate the Bone Resorption and Bone Regeneration for Preventing Glucocorticoids-Induced Osteonecrosis of the Femoral Head.

BACKGROUND: Osteonecrosis of the femoral head (ONFH) is a challenge for surgeons and is still without effective treatment method. This study is aimed at evaluating the combined pharmacotherapy with alendronate and desferoxamine for preventing glucocorticoid-induced osteonecrosis of the femoral head (GIOFH) and evaluating the efficacy of the combined medicine in regulating the bone resorption and bone regeneration. MATERIALS AND METHODS: Thirty-six rats were randomly assigned to three groups: group A received alendronate and desferoxamine (n = 12), group B received alendronate only (n = 12), and group C acted as the control group received placebo (n = 12). All rats induced the GIOFH using methylprednisolone combined with lipopolysaccharide. Eight weeks later, all rats were killed and their tissues were subjected to radiographic and histological analyses. RESULTS: According to the results, alendronate administration improved the trabecular thickness and separation in micro-CT analysis but had no significant evidence in increasing the bone area and decreasing the ratio of osteocyte lacunae in histological analysis when compared with the control group. Meanwhile, the alendronate group had more OCs, but less OCN and VEGF levels along with decreased p-AKT, HIF-1α, RANKL, and NFATc1 expressions than the control group. For comparison, alendronate combined with DFO further improved the bone volume, trabecular number, trabecular separation, and trabecular thickness with lower ratio of osteocyte lacunae and OC number, higher expression of OCN and VEGF and upregulated signal factors of HIF-1α and ß-catenin, and decreased RANKL and NFATc1. CONCLUSION: Combined pharmacotherapy with alendronate and desferoxamine provide significant effects in regulating the bone resorption and bone regeneration for preventing GIOFN.