Unraveling the genetic basis of the causal association between inflammatory cytokines and osteonecrosis.

Background: Previous studies have reported that the occurrence and development of osteonecrosis is closely associated with immune-inflammatory responses. Mendelian randomization was performed to further assess the causal correlation between 41 inflammatory cytokines and osteonecrosis. Methods: Two-sample Mendelian randomization utilized genetic variants for osteonecrosis from a large genome-wide association study (GWAS) with 606 cases and 209,575 controls of European ancestry. Another analysis included drug-induced osteonecrosis with 101 cases and 218,691 controls of European ancestry. Inflammatory cytokines were sourced from a GWAS abstract involving 8,293 healthy participants. The causal relationship between exposure and outcome was primarily explored using an inverse variance weighting approach. Multiple sensitivity analyses, including MR-Egger, weighted median, simple model, weighted model, and MR-PRESSO, were concurrently applied to bolster the final results. Results: The results showed that bFGF, IL-2 and IL2-RA were clinically causally associated with the risk of osteonecrosis (OR=1.942, 95% CI=1.13-3.35, p=0.017; OR=0.688, 95% CI=0.50-0.94, p=0.021; OR=1.386, 95% CI=1.04-1.85, p = 0.026). there was a causal relationship between SCF and drug-related osteonecrosis (OR=3.356, 95% CI=1.09-10.30, p=0.034). Conclusion: This pioneering Mendelian randomization study is the first to explore the causal link between osteonecrosis and 41 inflammatory cytokines. It conclusively establishes a causal association between osteonecrosis and bFGF, IL-2, and IL-2RA. These findings offer valuable insights into osteonecrosis pathogenesis, paving the way for effective clinical management. The study suggests bFGF, IL-2, and IL-2RA as potential therapeutic targets for osteonecrosis treatment.

Identifying the causal relationship between immune factors and osteonecrosis: a two-sample Mendelian randomization study.

A wealth of evidence intimates a profound connection between the immune system and osteonecrosis, albeit the specific immune factors underlying this connection remain largely veiled. A bidirectional Mendelian randomization (MR) study was conducted based on genome-wide association study summary data to identify causal links between 731 immune factors and osteonecrosis including drug-induced osteonecrosis. Preliminary MR analysis was accomplished utilizing the inverse-variance weighted method under a multiplicative random effects model, and heterogeneity and potential horizontal pleiotropy were evaluated through Cochrane's Q-test, MR-Egger intercept test, MR-PRESSO global test, and leave-one-out analysis. Upon false discovery rate correction, the gene-predicted level of one immune factor (CD62L - monocyte %monocyte) exhibited a significant positive correlation with osteonecrosis, while eight immune traits associated with monocytes, dendritic cells, and NK cells demonstrated significant causal effects with drug-induced osteonecrosis. Reverse MR revealed no significant correlations. This MR research provides genetic evidence for the causal associations between a broad spectrum of immune factors and osteonecrosis. Such a study aids in unraveling the intricate interaction patterns between the immune and skeletal systems, elucidating the pathogenesis of osteonecrosis, and identifying potential novel therapeutic approaches.

17 variants interaction of Wnt/ß-catenin pathway associated with development of osteonecrosis of femoral head in Chinese Han population.

The genes of Wnt/ß-catenin pathway may have potential roles in fat accumulation of Non-traumatic osteonecrosis of the femoral head (ONFH), but the effects of their variants in the pathway on ONFH development have been remained unclear. To explore the potential roles of the variants in the development of ONFH, we completed the investigation of the paired interactions as well as their related biological functions of 17 variants of GSK3ß, LRP5, and FRP4 genes etc. in the pathway. The genotyping of the 17 variants were finished by MASS ARRAY PLATFORM in a 560 ONFH case-control system. The association of variants interactions with ONFH risk and clinical traits was evaluated by logistic regression analysis etc. and bioinformatics technology. The results showed that the genotype, allele frequency, and genetic models of Gsk3ß rs334558 (G/A), SFRP4 rs1052981 (A/G), and LRP5 rs312778 (T/C) were significantly associated with the increased and decreased ONFH risk and clinical traits, respectively (P < 0.001-0.0002). Particularly, the paired interactions of six variants as well as eight variants also showed statistically increased and decreased ONFH risk, bilateral hip lesions risk and stage IV risk of ONFH, respectively (P < 0.044-0.004). Our results not only at the first time simultaneously showed exact serum lipid disorder and abnormal platelet function of ONFH in the same study system with the 17 variants polymorphisms of Wnt/ß-catenin pathway but also shed light on the variants closely intervening the lipid disorder and abnormal coagulation of ONFH.

BMP6 and VDR gene polymorphisms are associated with osteonecrosis in a sickle cell anaemia cohort.

The occurrence and severity of osteonecrosis in sickle cell anaemia (SCA) vary due to risk factors, including genetic modifiers. Bone morphogenetic proteins (BMPs), particularly BMP6, and the vitamin D receptor (VDR) play key roles in cartilage and bone metabolism, making them potential contributors to orthopaedic outcomes in SCA. Here, we evaluated the association of polymorphisms in BMP6 (rs3812163, rs270393 and rs449853) and VDR (FokI rs2228570 and Cdx2 rs11568820) genes with osteonecrosis risk in a Brazilian SCA cohort. A total of 177 unrelated SCA patients were selected. The AA genotype of BMP6 rs3812163 was independently associated with a lower osteonecrosis risk (p = 0.015; odds ratio (OR): 0.38; 95% confidence interval (CI): 0.18-0.83) and with the long-term cumulative incidence of osteonecrosis (p = 0.029; hazard ratio: 0.56, 95% CI: 0.34-0.94). The VDR rs2228570 TT genotype was independently associated with a lower osteonecrosis risk (p = 0.039; OR: 0.14; 95% CI: 0.02-0.90). In summary, our results provide evidence that BMP6 rs3812163 and the VDR rs2228570 might be implicated in osteonecrosis pathophysiology in SCA and might help identify individuals at high risk.

Exploring molecular mechanisms of intra-articular changes in osteonecrosis of femoral head using DIA proteomics and bioinformatics.

PURPOSE: This study is aimed to delve into the crucial proteins associated with hormonal osteonecrosis of the femoral head (ONFH) and its intra-articular lesions through data-independent acquisition (DIA) proteomics and bioinformatics analysis. METHODS: We randomly selected samples from eligible ONFH patients and collected samples from the necrotic area of the femoral head and load-bearing cartilage. The control group comprised specimens from the same location in patients with femoral neck fractures. With DIA proteomics, we quantitatively and qualitatively tested both groups and analyzed the differentially expressed proteins (DEPs) between groups. Additionally, we enriched the analysis of DEP functions using gene ontology terms and Kyoto Encyclopedia of Genes and Genomes pathways and verified the key proteins in ONFH through Western blot. RESULTS: Proteomics experiment uncovered 937 common DEPs (422 upregulated and 515 downregulated) between the two groups. These DEPs mainly participate in biological processes such as hidden attributes, catalytic activity, molecular function regulators, and structural molecule activity, and in pathways such as starch and sucrose metabolism, ECM-receptor interaction, PI3K-Akt signaling, complement and coagulation cascades, IL-17 signaling, phagosome, transcriptional misregulation in cancers, and focal adhesion. Through protein-protein interaction network target gene analysis and Western blot validation, we identified C3, MMP9, APOE, MPO, LCN2, ELANE, HPX, LTF, and THBS1 as key proteins in ONFH. CONCLUSIONS: With DIA proteomics and bioinformatics analysis, this study reveals the molecular mechanisms of intra-articular lesions in ONFH. A correlation in the necrotic area and load-bearing cartilage of ONFH at ARCO stages IIIB-IV as well as potential key regulatory proteins was identified. These findings will help more deeply understand the pathogenesis of ONFH and may provide important clues for seeking more effective treatment strategies.

Medication-Related Osteonecrosis of the Jaw: A Systematic Review and a Bioinformatic Analysis.

The objective was to evaluate the current evidence regarding the etiology of medication-related osteonecrosis of the jaw (MRONJ). This study systematically reviewed the literature by searching PubMed, Web of Science, and ProQuest databases for genes, proteins, and microRNAs associated with MRONJ from the earliest records through April 2023. Conference abstracts, letters, review articles, non-human studies, and non-English publications were excluded. Twelve studies meeting the inclusion criteria involving exposure of human oral mucosa, blood, serum, saliva, or adjacent bone or periodontium to anti-resorptive or anti-angiogenic agents were analyzed. The Cochrane Collaboration risk assessment tool was used to assess the quality of the studies. A total of 824 differentially expressed genes/proteins (DEGs) and 22 microRNAs were extracted for further bioinformatic analysis using Cytoscape, STRING, BiNGO, cytoHubba, MCODE, and ReactomeFI software packages and web-based platforms: DIANA mirPath, OmicsNet, and miRNet tools. The analysis yielded an interactome consisting of 17 hub genes and hsa-mir-16-1, hsa-mir-21, hsa-mir-23a, hsa-mir-145, hsa-mir-186, hsa-mir-221, and hsa-mir-424. A dominance of cytokine pathways was observed in both the cluster of hub DEGs and the interactome of hub genes with dysregulated miRNAs. In conclusion, a panel of genes, miRNAs, and related pathways were found, which is a step toward understanding the complexity of the disease.

Pyroptosis -related potential diagnostic biomarkers in steroid-induced osteonecrosis of the femoral head.

PURPOSE: Steroid-induced necrosis of the femoral head (SONFH) is a refractory orthopedic hip disease occurring in young and middle-aged people, with glucocorticoids being the most common cause. Previous experimental studies have shown that cell pyroptosis may be involved in the pathological process of SONFH, but its pathogenesis in SONFH is still unclear. This study aims to screen and validate potential pyroptosis-related genes in SONFH diagnosis by bioinformatics analysis to further elucidate the mechanism of pyroptosis in SONFH. METHODS: There were 33 pyroptosis-related genes obtained from the prior reviews. The mRNA expression was downloaded from GSE123568 dataset in the Gene Expression Omnibus (GEO) database, including 10 non-SONFH (following steroid administration) samples and 30 SONFH samples. The pyroptosis-related differentially expressed genes involved in SONFH were identified with "affy" and "limma" R package by intersecting the GSE123568 dataset with pyroptosis genes. In addition, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses of the pyroptosis-related differentially expressed genes involved in SONFH were conducted by "clusterProfiler" R package and visualized by "GOplot" R package. Then, the correlations between the expression levels of the pyroptosis-related differentially expressed genes involved in SONFH were confirmed with "corrplot" R package. Moreover, the protein-protein interaction (PPI) network was analysed by using GeneMANIA database. Next, The ROC curve of pyroptosis-related differentially expressed genes were analyzed by "pROC" R package. RESULTS: A total of 10 pyroptosis-related differentially expressed genes were identified between the peripheral blood samples of SONFH patients and non-SONFH patients based on the defined criteria, including 20 upregulated genes and 10 downregulated genes. The GO and KEGG pathway enrichment analyses revealed that these 10 pyroptosis-related differentially expressed genes involved in SONFH were particularly enriched in cysteine-type endopeptidase activity involved in apoptotic process, positive regulation of interleukin-1 beta secretion and NOD-like receptor signaling pathway. Correlation analysis revealed significant correlations among the 10 differentially expressed pyroptosis-related genes involved in SONFH. The PPI results demonstrated that the 10 pyroptosis-related differentially expressed genes interacted with each other. Compared to non-SONFH samples, these pyroptosis-related differentially expressed genes had good predictive diagnostic efficacy (AUC = 1.000, CI = 1.000-1.000) in the SONFH samples, and NLRP1 had the highest diagnostic value (AUC: 0.953) in the SONFH samples. CONCLUSIONS: There were 10 potential pyroptosis-related differentially expressed genes involved in SONFH were identified via bioinformatics analysis, which might serve as potential diagnostic biomarkers because they regulated pyroptosis. These results expand the understanding of SONFH associated with pyroptosis and provide new insights to further explore the mechanism of action and diagnosis of pyroptosis associated in SONFH.

Menaquinone-4 prevents medication-related osteonecrosis of the jaw through the SIRT1 signaling-mediated inhibition of cellular metabolic stresses-induced osteoblast apoptosis.

Long-term usage of bisphosphonates, especially zoledronic acid (ZA), induces osteogenesis disorders and medication-related osteonecrosis of the jaw (MRONJ) in patients, thereby contributing to the destruction of bone remodeling and the continuous progression of osteonecrosis. Menaquinone-4 (MK-4), a specific vitamin K2 isoform converted by the mevalonate (MVA) pathway in vivo, exerts the promotion of bone formation, whereas ZA administration suppresses this pathway and results in endogenous MK-4 deficiency. However, no study has evaluated whether exogenous MK-4 supplementation can prevent ZA-induced MRONJ. Here we showed that MK-4 pretreatment partially ameliorated mucosal nonunion and bone sequestration among ZA-treated MRONJ mouse models. Moreover, MK-4 promoted bone regeneration and inhibited osteoblast apoptosis in vivo. Consistently, MK-4 downregulated ZA-induced osteoblast apoptosis in MC3T3-E1 cells and suppressed the levels of cellular metabolic stresses, including oxidative stress, endoplasmic reticulum stress, mitochondrial dysfunction, and DNA damage, which were accompanied by elevated sirtuin 1 (SIRT1) expression. Notably, EX527, an inhibitor of the SIRT1 signaling pathway, abolished the inhibitory effects of MK-4 on ZA-induced cell metabolic stresses and osteoblast damage. Combined with experimental evidences from MRONJ mouse models and MC3T3-E1 cells, our findings suggested that MK-4 prevents ZA-induced MRONJ by inhibiting osteoblast apoptosis through suppression of cellular metabolic stresses in a SIRT1-dependent manner. The results provide a novel translational direction for the clinical application of MK-4 for preventing MRONJ.

Identification of key ferroptosis-related biomarkers in steroid-induced osteonecrosis of the femoral head based on machine learning.

BACKGROUND: This study was aimed to identify key ferroptosis-related biomarkers in steroid-induced osteonecrosis of the femoral head (SONFH) based on machine learning algorithm. METHODS: The SONFH dataset GSE123568 (including 30 SONFH patients and 10 controls) was used in this study. The differentially expressed genes (DEGs) were selected between SONFH and control groups, which were subjected to WGCNA. Ferroptosis-related genes were downloaded from FerrDb V2, which were then compared with DEGs and module genes. Two machine learning algorithms were utilized to identify key ferroptosis-related genes, and the underlying mechanisms were analyzed by GSEA. Correlation analysis between key ferroptosis-related genes and immune cells was analyzed by Spearman method. The drug-gene relationships were predicted in CTD. RESULTS: Total 2030 DEGs were obtained. WGCNA identified two key modules and obtained 1561 module genes. Finally, 43 intersection genes were identified as disease-related ferroptosis-related genes. After LASSO regression and RFE-SVM algorithms, 4 intersection genes (AKT1S1, BACH1, MGST1 and SETD1B) were considered as key ferroptosis-related gene. The 4 genes were correlated with osteoclast differentiation pathway. Twenty immune cells with significant differences were obtained between the groups, and the 4 key ferroptosis-related genes were correlated with most immune cells. In CTD, 41 drug-gene relationship pairs were finally obtained. CONCLUSIONS: The 4 key ferroptosis-related genes, AKT1S1, BACH1, MGST1 and SETD1B, were identified to play a critical role in SONFH progression through osteoclast differentiation and immunologic mechanisms. Additionally, all the 4 genes had good disease prediction effect and could act as biomarkers for the diagnosis and treatment of SONFH.

Glucocorticoid Receptor Polymorphisms and Avascular Osteonecrosis After Kidney Transplantation.

INTRODUCTION: Glucocorticoids (GCs) are commonly prescribed as immunosuppressive agents after kidney transplantation and their most common non-traumatic adverse effect is Avascular Necrosis (AVN) of the femoral head. In this regard, this study aimed to evaluate the glucocorticoid receptor (GR) polymorphisms among kidney transplant recipients and their potential role as a risk factor for the incidence of AVN. METHODS: In this study, 99 renal transplant recipients were evaluated for the correlations of GR polymorphisms including N363S (rs6195), BclI (rs41423247), ER22/23EK (rs6189/rs6190), and A3669G (rs6198) with AVN after renal transplantation. RESULTS: Results showed that none of the renal-transplanted patients neither with GC hypersensitive polymorphisms (N363S and BclI) nor with GC-resistant polymorphisms (A3669G and ER22/23EK) developed AVN (P > .05). In addition, the medications of the renal recipients with AVN were significantly different from the nonAVN patients (P < .001). CONCLUSION: The study results indicate that the GR polymorphisms have no critical roles in the susceptibility to AVN after renal transplantation. However, further studies to confirm the results are recommended.  DOI: 10.52547/ijkd.7221.

Identification of key genes and pathways associated with gender difference in osteonecrosis of the femoral head based on bioinformatics analysis.

OBJECTIVE: To identify different key genes and pathways between males and females by studying differentially expressed genes (DEGs). METHODS: The gene expression data of GSE123568 were downloaded from GEO database, including osteonecrosis of the femoral head (ONFH) samples from 3 females and 7 males, and DEGs between different gender were identified with R software. Protein-protein interaction (PPI) network was constructed to further analyze the interactions between overlapping DEGs, and finally, GO, KEGG and gene set enrichment analysis (GSEA) were conducted for enrichment analysis. RESULTS: 131 DEGs were identified between ONFH females and ONFH males, including 76 up-regulated genes and 55 down-regulated genes. And 10 hub genes were identified in PPI network, including SLC4A1, GYPA, CXCL8, IFIT1, GBP5, IFI44, IFI44L, IFIT3, KEL and AHSP. Functional enrichment analysis revealed that these genes were mainly enriched in cGMP-PKG signaling pathway, Fatty acid degradation, Non-alcoholic fatty liver disease, Systemic lupus erythematosus, Hematopoietic cell lineage and NO-cGMP-PKG signaling. CONCLUSIONS: NO-cGMP-PKG signaling may play an important role in the occurrence and development of ONFH. SLC4A1, GYPA, CXCL8, GBP5 and AHSP may be key genes associated with gender difference in the progression of ONFH, which may be ideal targets or prognostic markers for the treatment of ONFH.

IRF8 and its related molecules as potential diagnostic biomarkers or therapeutic candidates and immune cell infiltration characteristics in steroid-induced osteonecrosis of the femoral head.

PURPOSE: Steroid-induced osteonecrosis of the femoral head (SONFH) was a refractory orthopedic hip joint disease in the young and middle-aged people, but the pathogenesis of SONFH remained unclear. We aimed to identify the potential genes and screen potential therapeutic compounds for SONFH. METHODS: The microarray was obtained for blood tissue from the GEO database, and then it identifies differentially expressed genes (DEGs). The DEGs were analyzed to obtain the differences in immune cell infiltration. The gene functional enrichment analysis of SONFH was analyzed. The PPI of DEGs was identified through the STRING database, and the cluster modules and hub genes were ascertained using MCODE and CytoHubba, and the ROC curve of hub genes was analyzed, and the tissues distribution of hub genes was understood by the HPA, Bgee and BioGPS databases. The hub genes and target miRNAs and corresponding upstream lncRNAs were predicted by TargetScan, miRDB and ENCORI database. Subsequently, we used CMap, DGIdb and L1000FWD databases to identify several potential therapeutic molecular compounds for SONFH. Finally, the AutoDockTools Vina, PyMOL and Discovery Studio were employed for molecular docking analyses between compounds and hub genes. RESULTS: The microarray dataset GSE123568 was obtained related to SONFH. There were 372 DEGs including 197 upregulated genes and 175 downregulated genes by adjusted P value < 0.01 and |log2FC|> 1. Several significant GSEA enrichment analysis and biological processes and KEGG pathway associated with SONFH were identified, which were significantly related to cytoskeleton organization, nucleobase-containing compound catabolic process, NOD-like receptor signaling pathway, MAPK signaling pathway, FoxO signaling pathway, neutrophil-mediated immunity, neutrophil degranulation and neutrophil activation involved in immune response. Activated T cells CD4 memory, B cells naïve, B cells memory, T cells CD8 and T cells gamma delta might be involved in the occurrence and development of SONFH. Three cluster modules were identified in the PPI network, and eleven hub genes including FPR2, LILRB2, MNDA, CCR1, IRF8, TYROBP, TLR1, HCK, TLR8, TLR2 and CCR2 were identified by Cytohubba, which were differed in bone marrow, adipose tissue and blood, and which had good diagnostic performance in SONFH. We identified IRF8 and 10 target miRNAs that was utilized including Targetsan, miRDB and ENCORI databases and 8 corresponding upstream lncRNAs that was revealed by ENCORI database. IRF8 was detected with consistent expression by qRT-PCR. Based on the CMap, DGIdb and L1000FWD databases, the 11 small molecular compounds that were most strongly therapeutic correlated with SONFH were estradiol, genistein, domperidone, lovastatin, myricetin, fenbufen, rosiglitazone, sirolimus, phenformin, vorinostat and vinblastine. All of 11 small molecules had good binding affinity with the IRF8 in molecular docking. CONCLUSION: The occurrence of SONFH was associated with a "multi-target" and "multi-pathway" pattern, especially related to immunity, and IRF8 and its noncoding RNA were closely related to the development of SONFH. The CMap, DGIdb and L1000FWD databases could be effectively used in a systematic manner to predict potential drugs for the prevention and treatment of SONFH. However, additional clinical and experimental research is warranted.

Familial Thrombophilia Is Associated With Primary Multifocal Osteonecrosis: A Case-Control Study of 40 Patients.

To characterize pathoetiologic associations of heritable thrombophilia-hypofibrinolysis with idiopathic (primary) multifocal osteonecrosis (ON) (≥3 ON anatomic sites), we prospectively studied 28 women and 12 men with primary multifocal ON compared with 27 women and 24 men with primary nonmultifocal ON (<3 sites) and 110 healthy controls without ON. The 40 cases with primary multifocal ON differed from controls for 3 familial thrombophilias: Factor V Leiden heterozygosity (6 of 40 [15%] vs 2 of 109 [2%], P=.002), G20210A prothrombin gene heterozygosity (6 of 40 [15%] vs 3 of 110 [3%], P=.011), and high (>150%) Factor VIII (8 of 40 [20%] vs 7 of 103 [7%], P=.031). These case-control familial coagulation differences paralleled those in 51 concurrently evaluated cases with primary nonmulti-focal ON, 7 of 51 (14%) of whom had Factor V Leiden heterozygosity vs 2% of controls (P=.005) and 14 of 44 (32%) of whom had high Factor VIII vs 7 of 103 (7%) of controls (P=.0002). Recognition of familial thrombophilia as a common pathoetiology of primary multifocal ON provides an opportunity for early anticoagulation (before joint collapse), allowing both prophylaxis and therapy aimed at relieving pain and slowing or stopping progression of the disease to joint collapse. [Orthopedics. 2023;46(3):164-168.].

Downregulation of miR-30b-5p Facilitates Chondrocyte Hypertrophy and Apoptosis via Targeting Runx2 in Steroid-Induced Osteonecrosis of the Femoral Head.

As a widely used steroid hormone medicine, glucocorticoids have the potential to cause steroid-induced osteonecrosis of the femoral head (SONFH) due to mass or long-term use. The non-coding RNA hypothesis posits that they may contribute to the destruction and dysfunction of cartilages as a possible etiology of SONFH. MiR-30b-5p was identified as a regulatory factor in cartilage degeneration caused by methylprednisolone (MPS) exposure in our study through cell transfection. The luciferase reporter assay confirmed that miR-30b-5p was downregulated and runt-related transcription factor 2 (Runx2) was mediated by miR-30b-5p. The nobly increased expression of matrix metallopeptidase 13 (MMP13) and type X collagen (Col10a1) as Runx2 downstream genes contributed to the hypertrophic differentiation of chondrocytes, and the efficiently upregulated level of matrix metallopeptidase 9 (MMP9) may trigger chondrocyte apoptosis with MPS treatments. The cell transfection experiment revealed that miR-30b-5p inhibited chondrocyte hypertrophy and suppressed MPS-induced apoptosis. As a result, our findings showed that miR-30b-5p modulated Runx2, MMP9, MMP13, and Col10a1 expression, thereby mediating chondrocyte hypertrophic differentiation and apoptosis during the SONFH process. These findings revealed the mechanistic relationship between non-coding RNA and SONFH, providing a comprehensive understanding of SONFH and other bone diseases.

Concurrence of osteonecrosis and steroid myopathy secondary to oral steroid therapy in a patient with ABCB1 gene polymorphisms: A case report.

Glucocorticoids (GCs) are widely used in various autoimmune diseases. Side effects may occur in patients with long-term or high-dose GC usage. Among them, steroid myopathy and osteonecrosis are two severe forms. We report a patient with pemphigus vulgaris on GC-treatment who developed muscle weakness when a cumulative dose of methylprednisolone reached about 20g (14-80mg/d for 2.5 years). Laboratory tests showed slightly elevated lactate dehydrogenase and hydroxybutyrate dehydrogenase. MRI revealed osteonecrosis in the femoral head, distal femur, and proximal tibia of both legs. The biopsy of the right quadriceps revealed atrophy of type II myofiber without leukocyte infiltration, which was suggestive of steroid myopathy. Genotyping of the patient showed 5G/5G genotype of the PAI-1 gene and CC genotype of the ABCB1 gene (C3435T), suggesting she was sensitive to GCs. The patient's lesions were considered to be GC-induced adverse events, which were improved with tapering GC. Therefore, it is important to recognize steroid-induced musculoskeletal side effects and genotyping favors personalized medication.

Long Noncoding RNA Zinc Finger Antisense 1 Affects Glucocorticoid-Induced Osteonecrosis of the Femoral Head by Performing as a ceRNA for MicroRNA-124-3p and Accelerating Transforming Growth Factor Type III Receptor.

In recent years, plentiful studies have uncovered the long noncoding RNA's (lncRNA's) momentous functions in osteonecrosis of the femoral head (ONFH), but the specific mechanism has not been fully illustrated. The study was to figure out lncRNA Zinc finger antisense 1 (LncZFAS1)'s biological function and its latent downstream molecular mechanism in glucocorticoid- (GC-) induced ONFH. The results manifested LncZFAS1 and transforming growth factor type III receptor (TGFBR3) were elevated, while microRNA- (miR-) 124-3p was reduced in ONFH tissues and cells. Knockdown LncZFA1 reduced rat femoral cell apoptosis, perfected bone microstructure and bone density, and accelerated osteogenic proteins bone morphogenetic protein- (BMP-) 9, BMP-3, and osteocalcin. In vitro studies manifested knockdown LncZFAS1 prevented GC-induced reduction in osteoblast advancement with facilitating osteoblast calcification capacity, ALP activity, and osteogenic proteins. Elevation of LncZFAS1 further aggravated GC-induced osteoblast injury, but this effect was turned around by enhancement of miR-124-3p or knockdown of TGFBR3. Mechanistically, LncZFAS1 performed as a sponge for miR-124-3p to mediate TGFBR3 expression to motivate GC-induced ONFH. All in all, the results of this study indicate the LncZFAS1/miR-124-3p/TGFBR3 axis is supposed to be a latent therapeutic molecular target for GC-induced ONFH.

Biology of Bone Morphogenetic Proteins in Skeleton Disease: Osteonecrosis in Sickle Cell Disease Patients.

Sickle cell disease (SCD) is an autosomal recessive trait of genetic hemoglobin disorder whose prevalence is varied from 5 to 25 % of the world population. It is characterized by the presence of hemoglobin (HbS) instead of normal hemoglobin (HbA). An individual suffering from sickle cell disease is likely to be at risk of osteonecrosis, which is a form of ischemic bone infarction which causes intolerable degenerative joint problems and can affect 30-50% of people with sickle cell disease. The femoral head is the most frequent epiphyseal location in osteonecrosis with sickle cell disease. In this review, the Bone morphogenetic protein (BMP)-a subfamily of transforming growth factor-ß (TGF-ß) characteristics outlined the osteoblastogenesis potentiality via using combinatorial or advanced treatment approaches. In this review, we aim to describe the Bone morphogenetic proteins' role in Skeleton diseases and discuss the potent osteogenic BMPs (majorly BMP-2, BMP-6, and BMP-7) with therapeutic benefits.

Polymorphisms and avascular necrosis in patients with sickle cell disease - A systematic review.

OBJECTIVE: To systematically establish whether there is an association between polymorphisms and avascular necrosis in patients with sickle cell disease. DATA SOURCE: The review, conducted according to PRISMA guidelines and registered with PROSPERO, was based on research of studies in PubMed, SciELO, LILACS, BVS databases and in the gray literature (Google Scholar and Open Gray) published until June 2020. The STROBE initiative was used to analyze the articles' quality. DATA SYNTHESIS: Ten articles were selected from the databases and two were included through manual search, totaling 12 studies. All samples gathered 2,362 patients. According to STROBE, seven studies fully and/or partially covered more than 70% of the essential items and two studies reached less than 60%, with an overall variation of 86.4-54.5%. The results indicate that polymorphisms in the genes of the bone morphogenetic protein 6 (BMP6), Klotho (KL) and Annexin A2 (ANXA2) may be associated with osteonecrosis in the context of sickle cell disease. Six articles addressed the polymorphism in the MTHFR enzyme gene, but only one found a positive association. Polymorphisms associated with the DARC receptor, the ITGA4 gene, CD36 and thrombophilia protein genes were not associated in any of the studies. CONCLUSIONS: The results indicate that the polymorphisms in BMP6, Klotho and ANXA2 genes may be associated with avascular necrosis in patients with sickle cell disease. However, in order to confirm these genetic changes as risk factors, further studies with greater statistical power and methodological rigor are needed.

Cyclic Polypeptide D7 Protects Bone Marrow Mesenchymal Cells and Promotes Chondrogenesis during Osteonecrosis of the Femoral Head via Growth Differentiation Factor 15-Mediated Redox Signaling.

Osteonecrosis of the femoral head (ONFH) is a debilitating disease that is closely associated with the clinical application of high-dose glucocorticoids. Elevated oxidative stress contributes to the pathophysiological changes observed in ONFH. The lack of effective treatments besides surgical intervention highlights the importance of finding novel therapeutics. Our previous studies demonstrated that D7, a cyclic polypeptide, enhances the adhesion, expansion, and proliferation of bone marrow mesenchymal stem cells (BMSCs). Therefore, in this study, we investigated the therapeutic effects of D7 against ONFH in BMSCs and evaluated the underlying mechanisms. First, we screened for ONFH risk factors. Then, we applied D7 treatment to steroid-induced ONFH (SONFH) in an in vitro model produced by dexamethasone (DEX) to further elucidate the underlying mechanisms. We found negative correlations among oxidative stress marker expression, growth differentiation factor 15 (GDF15) levels, and ONFH. Furthermore, we demonstrated that DEX inhibited the proliferation and induced apoptosis of BMSCs by suppressing GDF15/AKT/mammalian target of rapamycin (mTOR) signaling. D7 alleviated DEX-induced BMSCs injury and restored the chondrogenic function of BMSCs by activating GDF15/AKT/mTOR signaling. In addition, DEX-induced excessive reactive oxygen species (ROS) generation was an upstream trigger of GDF15-mediated signaling, and D7 ameliorated this DEX-induced redox imbalance by restoring the expression of antioxidants, including superoxide dismutase (SOD) 1, SOD2, and catalase, via regulation of GDF15 expression. In conclusion, our findings revealed the potential therapeutic effects of D7 in SONFH and showed that this protective function may be mediated via inhibition of DEX-induced ROS and activation of GDF15/AKT/mTOR signaling, thereby providing insights into the potential applications of D7 in SONFH treatment.

lncRNA FGD5-AS1 Regulates Bone Marrow Stem Cell Proliferation and Apoptosis by Affecting miR-296-5p/STAT3 Axis in Steroid-Induced Osteonecrosis of the Femoral Head.

BACKGROUND: Osteonecrosis of the femoral head (ONFH) is a common hip joint disease, which is more harmful and seriously affects the lives of patients. This study aims to clarify the regulatory mechanism of lncRNA FGD5-AS1 in ONFH. METHODS: The expression of the protein and mRNA was detected by RT-qPCR and Western blot assay. The regulatory mechanism of lncRNA FGD5-AS1 was detected by the dual-luciferase reporter assay, CCK-8 assay, and flow cytometry assay. RESULTS: Dex can inhibit cell proliferation and differentiation and induce apoptosis in hBMSCs in a dose-dependent manner. Overexpression of lncRNA FGD5-AS1 promoted cell proliferation and restrained apoptosis in Dex-treated hBMSCs. In addition, lncRNA FGD5-AS1 acts as a sponge for miR-296-5p. Also, miR-296-5p directly targets STAT3. More importantly, miR-296-5p and STAT3 can affect the function of lncRNA FGD5-AS1 in Dex-treated hBMSCs. CONCLUSION: lncRNA FGD5-AS1 promotes cell proliferation and inhibits apoptosis in steroid-induced ONFH through acting as a sponge for miR-296-5p and upregulation of STAT3.