Association of Genes Variants in RANKL/RANK/OPG Signaling Pathway with the Development of Osteonecrosis of the Femoral Head in Chinese Population

Machine learning-mediated identification of ferroptosis-related genes in osteonecrosis of the femoral head

Osteonecrosis of the femoral head (ONFH) is a condition caused by a disruption or damage to the femoral head's blood supply, which causes the death of bone cells and bone marrow components and prevents future regeneration. Ferroptosis, a type of controlled cell death, is caused by iron-dependent lipid peroxidation. Here, we identified ferroptosis-related genes and infiltrating immune cells involved in ONFH and predicted the underlying molecular mechanisms. The GSE123568 dataset was subjected to differential expression analysis to identify genes related to ferroptosis. Subsequently, GO and KEGG pathway enrichment analyses, as well as protein-protein interaction (PPI) network analysis, were conducted. Hub genes involved in ferroptosis were identified using machine learning and other techniques. Additionally, immune infiltration analysis and lncRNA-miRNA-mRNA network prediction analysis were performed. Finally, we determined whether ferroptosis occurred by measuring iron content. The hub genes were validated by ROC curve analysis and qRT-PCR. Four ferroptosis-related hub genes (MAPK3, PTGS2, STK11, and SLC2A1) were identified. Additionally, immune infiltration analysis revealed a strong correlation among ONFH, hub genes, and various immune cells. Finally, we predicted the network relationship between differentially expressed lncRNAs and hub genes in the lncRNA-miRNA-mRNA network. MAPK3, PTGS2, STK11, and SLC2A1 have been identified as potential ferroptosis-related biomarkers and drug targets for the diagnosis and prognosis of ONFH, while some immune cells, as well as the interaction between lncRNA, miRNA, and mRNA, have also been identified as potential pathogenesis markers and therapeutic targets.

Study of genes polymorphisms in RANK/RANKL/OPG and WNT signaling pathways and their associations with bone parameters in broiler chicken

Limb problems are one of the most common problems with fast-growing meat-type chickens. Various bone abnormalities, which can lead to limping, bone weakness, or even fractures, bring overall discomfort to birds and a loss of production. Genetic aspects are often associated with these side effects on bone stability and are also cited as the dominant cause. These points to a close negative relationship of genetic selection for rapid growth with traits involved in bone integrity. Due to the assumption of an additive genetic background, improvements through genetic tools can be used. Our study is focused on selected genes of important signaling pathways for bone metabolism. We tried to detect polymorphisms that would show associations with selected bone parameters in a total of 48 broilers. Those were fast-growing Ross 308 hybrids and slow-growing Hubbard M22BxJA87A hybrids. The TNFRSF11A and WISP1 genes were tested. A total of fourteen polymorphisms were found, three of them were synonymous and five in the intron. In the case of four polymorphisms found in exons of the TNFRSF11A gene (c.11G > T, c.31G > A, c.37C > G, c.514G > A), associations with the observed bone parameters (bone strength, bone dimensions and bone mass) were demonstrated. The genetic architecture of bone traits is not fully understood, therefore the present study and the knowledge gained can help to increase the potential in poultry breeding processes and thus reduce the death of individuals.

Association of Specific Genetic Polymorphisms with Atraumatic Osteonecrosis of the Femoral Head: A Narrative Review

INTRODUCTION

Atraumatic ONFH is one of the leading cause of hip morbidity in the working-age group. It is a multi-factorial disease whose root cause can be attributed to single-nucleotide polymorphism. Identifying such polymorphisms could pave the way for new modalities of treatment for ONFH.

METHODOLOGY

Two databases were electronically searched for relevant articles. The articles were screened through titles, abstract and full texts to include the relevant studies. A secondary search was done through the reference list of selected articles.

RESULTS

A total of 52 studies were included among the 181 hits. All 181 were case-control studies. Summary of these studies identifies multiple SNPs which can cause ONFH. There were 117 SNPs in all 181 studies, of which 92 were associated with the causation of ONFH and 25 were protective against ONFH.

CONCLUSION

SNPs play an essential role in causing atraumatic ONFH. Identification of SNP that contribute to causing ONFH may help reduce the disease burden by early identification, diagnosis and treatment, including targeted gene therapy.

Association between Osteoprotegerin and Charcot Neuroarthropathy: a systematic review

AIMS

Osteoprotegerin (OPG) has been associated with Charcot Neuroarthropathy (CN); however, three studied OPG polymorphisms (1181C > G, 245A > C and 950 T > C) have yielded conflicting results. Therefore, this meta-analysis was conducted to determine the difference in serum OPG concentrations between healthy controls and diabetics with and without CN and the effect OPG polymorphisms have on CN development.

METHODS

PubMed, LILAC, SCOPUS, and EBSCO databases and retrieved publications' bibliographies were searched for studies that examined for OPG and CN. Depending on the heterogeneity, fixed or random effects were used to calculate the pooled odds ratio (OR) or standard difference in means (SDM) with 95% confidence intervals (95%CI) for 5 genetic models (heterozygous, homozygous, dominant, recessive, and allelic) and serum concentrations, respectively.

RESULTS

Seven publications (12 studies) demonstrated that serum OPG concentrations were more elevated in subjects with CN (SDM = 0.719, 95%CI = 0.555-0.883, p < 0.001). When CN was compared to healthy controls or diabetics, the difference was more prominent for healthy controls (SDM = 1.043, 95%CI = 0.676-1.409, p < 0.001) than diabetics (SDM = 0.639, 95%CI = 0.456-0.821, p < 0.001) and the SDM difference was significant (p = 0.013). Using 6 publications (9 studies), neither the 1181C > G or the 950 T > C polymorphisms showed any significant associations for any genetic model. For the 245A > C polymorphism, only the homozygous genetic model showed a significant association between the polymorphism and CN (OR = 2.850, 95%CI: 1.051-7.729, p = 0.040).

CONCLUSIONS

Here, we determined a potential correlation between the CN and serum OPG concentrations and that only the CC genotype of the 245A > C polymorphism showed an increased risk of developing CN.

Integrated analysis of transcriptome and proteome to explore the genes related to steroid-induced femoral head necrosis

PURPOSE

Femoral head necrosis (FHN) is a common disease of hip. However, the pathogenesis of FHN is not well understood. This study attempted to explore the potentially important genes and proteins involved in FHN.

METHODS

We integrated the transcriptomic and proteomic methods to quantitatively screen the differentially expressed genes (DEGs) and proteins (DEPs) between Control and FHN groups. Gene ontology (GO) terms and KEGG pathway enrichment analysis were used to assess the roles of DEGs and DEPs. qRT-PCR and western blot were performed to verify the key genes/proteins in FHN. CCK-8 assay was performed to measure cell viability. The protein expression of Bax and Bcl-2 were used to evaluate cell apoptosis.

RESULTS

Transcriptome and proteome studies indicated 758 DEGs and 1097 DEPs between Control and FHN groups, respectively. Cell division, extracellular exosome, and serine-type endopeptidase activity were the most common terms in biological process (BP), cellular component (CC), and molecular function (MF) enrichment, respectively. DEPs were mainly enriched in cellular process, cell, and binding for BP, CC, and MF categories, respectively. DEGs were mainly involved in PI3K-Akt pathway and DEPs were mainly focused in glycolysis/gluconeogenesis pathway. Notably, 14 down-regulated and 22 up-regulated genes/proteins were detected at both the transcript and protein level. LRG1, SERPINE2, STMN1, COL14A1, SLC37A2, and MMP2 were determined as the key genes/proteins in FHN. SERPINE2/STMN1 overexpression increased viability and decreased apoptosis of dexamethasone-treated MC3T3-E1 cells.

CONCLUSIONS

Our study investigated some pivotal regulatory genes/proteins in the pathogenesis of FHN, providing novel insight into the genes/proteins involved in FHN.

FKBP-CaN-NFAT pathway polymorphisms selected by in silico biological function prediction are associated with tacrolimus efficacy in renal transplant patients

AIM

The aim of the present study was to investigate the potential effects of genetic variations in the FKBP-CaN-NFAT pathway on clinical events associated with tacrolimus efficacy in Chinese renal transplant patients.

METHODS

One hundred and forty Chinese renal transplant patients of Han ethnicity with over five years of follow-up were enrolled in our study. A pool of single nucleotide polymorphisms (SNPs) (1284 SNPs) was extracted from the Ensembl database according to chromosomal regions of the candidate genes. Next, 109 SNPs were screened out from this pool using multiple bioinformatics tools for subsequent genotyping using the MALDI-TOF-MS method. The associations of these candidate SNPs with acute rejection, nephrotoxicity, pneumonia and post-transplant estimated glomerular filtration rate (eGFR) were explored.

RESULTS

Fourty-four SNPs were found to be associated with tacrolimus-related clinical drug response. Specifically, eight SNPs were associated with the incidence of biopsy-proven acute rejection, four SNPs were associated with the rate of nephrotoxicity, 16 SNPs were correlated with the onset of pneumonia, and 26 SNPs were found to significantly influence post-transplant eGFR trend. An elaborate scoring system was implemented to prioritize the validation of these potentially causal SNPs. In particular, NFATC2 rs150348438 (G>T) performed well during integrative scoring (P_total=23.8) and was significantly associated with the occurrence of pneumonia (P = 0.0035, HR=0.91, 95% CI=0.85-0.97) and post-transplant eGFR levels (P = 0.000003).

CONCLUSIONS

NFATC2 rs150348438, rs6013219, rs1052653, and NFATC1 rs754093, ranking high in scoring, significantly affected the post-transplant eGFR and the incidence of pneumonia, acute rejection, and nephrotoxicity in renal transplant patients taking tacrolimus. Those SNPs may alter the expression and regulation of FKBP-CaN-NFAT pathway by influencing transcription regulation, mature mRNA degradation and RNA splicing, or protein coding. Critical SNPs of high ranking may serve as PD-associated pharmacogenetic biomarkers indicating individual response variability of TAC, and thus aid the clinical management of renal transplant patients.

The molecular mechanism of platelet lysate promotes transformation of non-union cells into osteoblasts

Background

Platelet lysate (PL) had a remarkable therapeutic effect on bone repair related diseases, such as delayed fracture healing, femoral head necrosis and meniscal tear. In this study, we investigated the effect of PL on patients with nonunion, cartilage repair and osteonecrosis, and to evaluate the effect of PL on nonunion cells proliferation and the effect of PL on OPG/RANKL signaling pathway in nonunion cell of male rats. To reveal the molecular mechanism of PL for bone healing.

Methods

We used different concentrations of PL to treat nonunion cells, then detected cell proliferation and protein expression levels of osteoprotegerin (OPG), RANKL, osteopontin (OPN), osteocalcin (OCN) and alkaline phosphatase (ALP).

Results

The proliferation rate of nonunion cells treated by 5% PL, was significantly higher than that of the control group (P<0.05). Surprisingly, there were no significant difference among the proliferation rates of nonunion cells treated by 8% PL, 10% FBS and the control group (P>0.05). the results of western blot analysis and immunofluorescence analysis showed that PL improved the expression of OPG, OPN, OCN and ALP proteins in nonunion cells, but PL had no effect on the expression of nuclear factor-κB ligand (RANKL) protein.

Conclusions

We found that PL had a remarkable therapeutic effect on bone repair related diseases; 5% PL significantly improved the proliferation rate of the nonunion cells; 10% PL had a significantly positive effect on improving the expression levels of osteogenic related genes.

Correlational analysis between neutrophil granulocyte levels and osteonecrosis of the femoral head

Background

The correlation between peripheral blood neutrophil level and osteonecrosis of the femoral head (ONFH) has not been extensively studied. Thus, we aimed to investigate the correlation between neutrophil level in the peripheral blood (neutrophil granulocyte) and ONFH.

Methods

A total of 984 cases of ONFH and femoral neck fractures (non-ONFH) diagnosed at the Department of Orthopedics at our institution between January 1, 2011 and December 31, 2016 were retrospectively reviewed. The ONFH and non-ONFH groups comprised 488 and 496 cases, respectively. Basic information and peripheral blood cell levels of the two groups were compared.

Results

The patients’ mean age was 59.89 ± 17.06 years (range: 38–82 years). There were 457 male and 527 female patients, with a male-to-female ratio of 1:1.15. We found that neutrophil granulocyte levels and percentage of neutrophil granulocytes were significantly different between the ONFH and non-ONFH groups. Multimodal regression analysis showed that the percentage of neutrophil granulocytes was an independent protective factor against ONFH.

Conclusions

The factors influencing ONFH are neutrophil granulocyte levels and percentage of neutrophil granulocytes. Percentage of neutrophil granulocytes has a significant correlation with aseptic femoral head necrosis, providing a new perspective and direction for further study of femoral head necrosis.

Identification of differentially expressed genes in hip cartilage with femoral head necrosis, based on genome‑wide expression profiles

Necrosis of the femoral head (NFH), a severe orthopedic disease in adults, involves the collapse of the femoral head. The pathophysiological mechanisms underlying NFH are yet to be fully investigated. The aim of the present study was to identify potentially important genes and signaling pathways involved in NFH and investigate their molecular mechanisms. Gene expression profiles of patients with NFH and healthy controls were compared using the Gene Expression Omnibus (GEO) database repository of the National Center of Biotechnology Information. GSE74089 from the GEO database included 4 patients with NFH and 4 healthy individuals. A total of 1,191 differentially expressed genes (DEGs) were identified between the patients with NFH and controls, including 743 upregulated and 448 downregulated DEGs. Then, Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis revealed that upregulated DEGs were mainly involved in the phosphoinositide 3-kinase/protein kinase B signaling pathway, focal adhesion and extracellular matrix-receptor interactions. Additionally, protein-protein interaction (PPI) analysis identified the most central DEGs as vascular endothelial growth factor A, Jun proto-oncogene, cyclin D1, fibroblast growth factor 2, HECT domain and ankyrin repeat-containing E3 ubiquitin protein ligase 1, protein kinase Cα, bone morphogenetic protein 2 and prostaglandin-endoperoxide synthase 2. PPI analysis also identified guanine nucleotide-binding protein, γ13 as the most commonly downregulated gene based on different centrality. The results of the present study may provide novel insight into the genes and associated pathways involved in NFH, and aid the identification of novel therapeutic targets and biomarkers in the treatment of NFH.

Association of Variant Interactions in RANK, RANKL, OPG, TRAF6, and NFATC1 Genes with the Development of Osteonecrosis of the Femoral Head

Multiple gene polymorphisms have been demonstrated to correlate with the susceptibility to osteonecrosis of the femoral head (ONFH). However, as a complex disease induced by multiple genes, the development of ONFH has rarely been reported to involve in gene interaction. In this study, we first explored the association of 10 variants interactions in receptor activator of nuclear factor-kappa B (RANK), RANK ligand (RANKL), osteoprotegerin (OPG), tumor necrosis factor receptor-associated factor 6 (TRAF6), and nuclear factor of activated T cells cytoplasmic 1 (NFATC1) genes with the development and clinical phenotypes of ONFH in a 377 ONFH case-control study with using Mass ARRAY^® platform. Our results showed that not only a total of 6 interactional variants in the paired 10 variants interactions were significantly associated with the development of ONFH (OPG rs2073617 and NFATC1 rs754093, p < 0.019; OPG rs2073618 and NFATC1 rs754093, p < 0.008; OPG rs2073617 and RANKL rs1054016, p < 0.039, respectively) but also a total of 4 paired interactional variants were found to involve significantly in the increased risk of bilateral hip lesions in ONFH (OPG rs2073617 and TRAF6 rs5030411, p = 0.044; RANK rs884205 and TRAF6 rs5030411, p = 0.045, respectively). Moreover, the results from generalized multifactor dimensionality reduction also showed that the five best models were identified and associated significantly with ONFH risk, p = 0.001, 0.01, 0.01, 0.01, and 0.01, respectively. Our results first suggest that the variants in RANK/RANKL/OPG pathway genes affected the development of ONFH in gene interaction manner through the interaction of the paired variants and multiple variants.

Etiologic Classification Criteria of ARCO on Femoral Head Osteonecrosis Part 2: Alcohol-Associated Osteonecrosis

BACKGROUND

Although alcohol is a leading risk factor for osteonecrosis of the femoral head (ONFH) and its prevalence reportedly ranges from 20% to 45%, there are no unified classification criteria for this subpopulation. In 2015, Association Research Circulation Osseous decided to develop classification criteria for alcohol-associated ONFH.

METHODS

In June of 2017, Association Research Circulation Osseous formed a task force to conduct a Delphi survey. The task force invited 28 experts in osteonecrosis/bone circulation from 8 countries. Each round of the Delphi survey included questionnaires, analysis of replies, and feedback reports to the panel. After 3 rounds of the survey, consensus was reached on the classification criteria. The response rates for the 3 Delphi rounds were 100% (round 1), 96% (round 2), and 100% (round 3).

RESULTS

The consensus on the classification criteria of alcohol-associated ONFH included the following: (1) patients should have a history of alcohol intake >400 mL/wk (320 g/wk, any type of alcoholic beverage) of pure ethanol for more than 6 months; (2) ONFH should be diagnosed within 1 year after alcohol intake of this dose; and (3) patients should not have other risk factor(s).

CONCLUSION

ARCO-established classification criteria to standardize clinical studies concerning AA-ONFH.

Sirt1/Foxo Axis Plays a Crucial Role in the Mechanisms of Therapeutic Effects of Erzhi Pill in Ovariectomized Rats

Background. Erzhi pill (EZP), a traditional Chinese herbal formula, has been widely used to treat postmenopausal osteoporosis (PMOP) in China. However, its molecular mechanisms remain unclear. The aim of the present study is to investigate the antiosteoporotic effect of EZP on an ovariectomized rat model of PMOP. We performed the biomarkers of bone metabolism disorder, bone morphology, bone mineral density (BMD), and bone biomechanics to confirm the successful establishment of the PMOP model. We then investigated the expression of biomarkers related to the Sirt1/Foxo axis. We also examined microRNA-132 (miR-132), a regulator in the Sirtuin1 (Sirt1) expression. The bone metabolism disorder, bone morphology, BMD, and bone biomechanics in ovariectomized rats were improved by EZP administration. The antiosteoporotic effect of EZP was confirmed. We also found that the expressions of Sirt1, Runx2, Foxo1, and Foxo3a were downregulated in ovariectomized rats, while being then upregulated by EZP administration. And the expression of PPAR-γ and miR-132 was upregulated in ovariectomized rats and then downregulated by EZP administration. These results provided evidence that Sirt1/Foxo axis related mechanism may play a crucial role in the therapeutic effects of EZP, indicating that Sirt1/Foxo axis can be considered as a potential therapeutic target for PMOP in the future.

[Microarchitecture features and pathology of necrotic region in patients with steroid-induced and alcohol-induced osteonecrosis of femoral head]

Objective

To investigate the pathological and microstructural features of the osteonecrosis samples from subjects with steroid-induced or alcohol-induced osteonecrosis of the femoral head (ONFH).

Methods

Thirty femoral head bone samples were collected from ONFH patients who underwent total hip arthroplasty between August 2015 and April 2016. There were 22 males and 8 females. The etiology of ONFH was alcohol-induced in 15 patients and steroid-induced in 15 patients. No significant difference of Association Research Circulation Osseous (ARCO) stage was found between alcohol-induced and steroid-induced ONFH ( Z=2.143, P=0.143). The femoral head bone samples in different areas (necrosis, sclerosis, and normal) from involved subjects was taken, and gross observation, HE staining were carried out (the rate of empty lacunaes was calculated). The intact femoral head was scanned by Micro-CT and the parameters of bone microstructure were analyzed quantitatively. The parameters included bone volume to total volume (BV/TV), bone surface area to bone volume ratio (BS/BV), bone mineral density (BMD), bone mineral content (BMC), structural model index (SMI), trabecular plate number (Tb. N), trabecular plate thickness (Tb. Th), and trabecular spacing (Tb. Sp).

Results

As observed in hard tissue slicing of both groups, the integrity of trabecular bone was destructed and cystic lesions left by the bone resorption was replaced by granulation tissues. Significant revascularization was found in granulation tissues of steroid-induced ONFH, but not in the alcohol-induced one. HE staining showed that the bone marrow structure was disordered in both group, as well as bone marrow necrosis and empty bone lacunaes noticed. The structure and integrity of trabecular bone of steroid-induced ONFH was far more severe whereas that of alcohol-induced one were thicker and better. The rate of empty bone lacunae in necrosis area of steroid-induced group was significantly higher than that of alcohol-induced one ( P<0.05), but no significant difference was found in sclerotic and normal areas between 2 groups ( P>0.05). Micro-CT showed that necrotic and sclerotic areas of both groups were low bone density. Bone structure in the former area was mostly heterogeneous. Further blood-rich granulation tissues formation was observed in the same places of hard tissue slicing, while the sclerotic one wasn't. The results of quantitative bone structure analysis showed that BV/TV, BMD, BMC, Tb.N, and Tb.Th of the necrotic and sclerotic areas of steroid-induced ONFH were significantly lower than those of alcohol-induced one ( P<0.01), BS/BV, SMI, and Tb.Sp of steroid-induced ONFH were significantly higher than those of alcohol-induced one ( P<0.01). No significant difference among the indexes above was found in the normal areas of both groups ( P>0.05).

Conclusion

The integrity of trabecular bone was destroyed in necrotic area of steroid-induced or alcohol-induced ONFH. However, they performed different features of osteonecrosis and contrasted with each other. The steroid-induced ONFH was characterized by multiple "osteolytic bone destruction", while the alcohol-induced one was manifested by some kinds of "coagulative destruction".

Tumor necrosis factor receptor-associated factor 6 as a nuclear factor kappa B-modulating therapeutic target in cardiovascular diseases: at the heart of it all

Inflammatory and immune signaling has been documented as a root cause of many cardiovascular pathologies. In this review, we explore the emerging role of tumor necrosis factor receptor-associated factor 6 (TRAF6)-nuclear factor kappa B (NF-κB) signaling axis in atherosclerosis, ischemic heart disease, pathologic cardiac hypertrophy or heart failure, myocarditis, and sepsis-induced cardiomyopathy. We discuss the current understanding of cardiac inflammation in heart disease, present the TRAF6 signaling axis in the heart, then summarize what is known about TRAF6 in pathophysiology of heart disease including proof-of-concept studies that identify the utility of blocking TRAF6 to attenuate cardiac dysfunction, which suggests that TRAF6 is a novel, druggable target in treating cardiovascular disease incurred by inflammatory processes.

Erratum: Association of Genes Variants in RANKL/RANK/OPG Signaling Pathway with the Development of Osteonecrosis of the Femoral Head in Chinese Population: Erratum

[This corrects the article DOI: 10.7150/ijms.19124.].