Association study of hypoxia inducible factor 1alpha (HIF1alpha) with osteonecrosis of femoral head in a Korean population

Dimethyloxalylglycine Attenuates Steroid-Associated Endothelial Progenitor Cell Impairment and Osteonecrosis of the Femoral Head by Regulating the HIF-1α Signaling Pathway

Endothelial impairment and dysfunction are closely related to the pathogenesis of steroid-associated osteonecrosis of the femoral head (SONFH). Recent studies have showed that hypoxia inducible factor-1α (HIF-1α) plays a crucial role in endothelial homeostasis maintenance. Dimethyloxalylglycine (DMOG) could suppress HIF-1 degradation and result in nucleus stabilization by repressing prolyl hydroxylase domain (PHD) enzymatic activity. Our results showed that methylprednisolone (MPS) remarkably undermined biological function of endothelial progenitor cells (EPC) by inhibiting colony formation, migration, angiogenesis, and stimulating senescence of EPCs, while DMOG treatment alleviated these effects by promoting HIF-1α signaling pathway, as evidenced by senescence-associated β-galactosidase (SA-β-Gal) staining, colony-forming unit, matrigel tube formation, and transwell assays. The levels of proteins related to angiogenesis were determined by ELISA and Western blotting. In addition, active HIF-1α bolstered the targeting and homing of endogenous EPCs to the injured endothelium in the femoral head. Histopathologically, our in vivo study showed that DMOG not only alleviated glucocorticoid-induced osteonecrosis but also promoted angiogenesis and osteogenesis in the femoral head as detected by microcomputed tomography (Micro-CT) analysis and histological staining of OCN, TRAP, and Factor Ⅷ. However, all of these effects were impaired by an HIF-1α inhibitor. These findings demonstrate that targeting HIF-1α in EPCs may constitute a novel therapeutic approach for the treatment of SONFH.

Analysis of the potential biological mechanisms of Danyu Gukang Pill against osteonecrosis of the femoral head based on network pharmacology

BACKGROUND

Osteonecrosis of the femoral head (ONFH) is still a challenge for orthopedists worldwide and can lead to disability if patients are not treated effectively. Danyu Gukang Pill (DGP), a traditional Chinese medicine (TCM) formulation, is recognized to be effective against ONFH. Nevertheless, its molecular mechanisms remain to be clarified.

METHODS

The active ingredients of DGP were collected from the online databases according to oral bioavailability (OB) and drug-likeness (DL). The potential targets of DGP were retrieved from the TCMSP database, while the potential targets of ONFH were obtained from the GeneCards and NCBI databases. The functions and signaling pathways of the common targets of DGP and ONFH were enriched by GO and KEGG analyses. Subsequently, molecular docking and in vitro cell experiments were performed to further validate our findings.

RESULTS

In total, 244 active ingredients of DGP and their corresponding 317 targets were obtained, and 40 ONFH-related targets were predicted. Afterwards, 19 common targets of DGP and ONFH were obtained and used as potential targets for the treatment of ONFH. Finally, combined with network pharmacology analysis, molecular docking and in vitro cell experiments, our study first demonstrated that the treatment effect of DGP on ONFH might be closely related to the two targets, HIF1A (HIF-1α) and VEGFA, and the HIF-1 signaling pathway.

CONCLUSIONS

This study is the first to investigate the molecular mechanisms of DGP in the treatment of ONFH based on network pharmacology. The results showed that DGP might up-regulate the expression of HIF-1α and VEGFA by participating in the HIF-1 signaling pathway, thus playing an anti-ONFH role.

Do biomarkers allow a differentiation between osteonecrosis of the femoral head and osteoarthritis of the hip? - a biochemical, histological and gene expression analysis

OBJECTIVE

Osteonecrosis of the femoral head (ONFH) is a devastating disease of the hip joint. Its early diagnosis is crucial to increase the chances of joint preserving, yet difficult due to similarities with osteoarthritis (OA) of the hip in its clinical appearance. The purpose of this study was to enhance the understanding of ONFH and its pathologic processes in contrast to OA and to identify serum biomarkers helping to improve the diagnosis of the disease.

DESIGN

Bone and bone marrow samples were collected from 24 patients diagnosed with OA and 25 patients with ONFH during total hip replacement surgery. RNA was isolated, histological examination, determination of free reactive oxygen species as well as gene expression and biomarker analysis were performed.

RESULTS

Histological analysis revealed differences in the structural and cellular pattern between the groups. Gene expression analysis revealed a significant upregulation for the genes ASPN, COL1A1, COL2A1 and IL6 and a significant downregulation for HIF1A in ONFH compared to OA group. Analysis of serum biomarkers showed significant differences between the groups for asporin and adiponectin. A final logistical regression model including the parameters adiponectin, asporin and HIF 1α was overall significant, explained 34.5 % of variance and classified 74.5 % of the cases correctly.

CONCLUSION

The combination of adiponectin, asporin and HIF 1α as serum biomarkers revealed a classification accuracy of 74.5 %. The information provided in this study may help to enhance the understanding of pathologic processes in ONFH and to elaborate further aspects of prediction and treatment.

Transcriptome landscape of the late-stage alcohol-induced osteonecrosis of the human femoral head

Osteonecrosis resulting from heavy ethanol consumption is one of the major causes of nontraumatic osteonecrosis of the femoral head (ONFH). The underlying pathological and molecular mechanisms remain elusive. In this study, we performed deep RNA sequencing from femoral heads of patients diagnosed with late-stage alcohol-induced ONFH (AIONFH), other types of ONFH and traumatic injury (bone fracture). Genome-wide gene expression analyses identified 690 differentially expressed mRNAs in AIONFH. Gene annotation and pathway analyses revealed significant dysregulated genes involved in hemostasis, angiogenesis and bone remodeling processes from the late-stage AIONFH. Notably, ADH1B, which codes for one of the major alcohol dehydrogenases, is significantly upregulated in AIONFH samples. Further, we found that the ADH1B protein was primarily expressed in smooth muscle cells of the blood vessels, stromal cells and adipocytes of the femoral heads of AIONFH patients; but was absent in other ONFH samples. Our analyses also revealed unique long non-coding RNA (lncRNA) expression profiles and identified novel lncRNAs in AIONFH. In addition, we observed a close co-expression correlation between lncRNAs and mRNAs in AIONFH suggesting that cis-gene regulation represents a major mechanism of action of human femoral lncRNAs. Further, the expression signature of lncRNAs, but not mRNAs, distinguishes AIONFH from other types of ONFH. Taken together, our studies uncovered novel molecular signatures associated with late-stage AIONFH in which the dysregulation of several key signaling pathways within the femoral head may be involved in AIONFH. Subsequently, lncRNAs may serve as potential biomarkers for diagnosis and therapeutic treatment of AIONFH. Further studies are needed to confirm that ADH1B is specifically upregulated in AIONFH and not generally upregulated in patients who consume alcohol excessively.

Effects of hypoxia environment on osteonecrosis of the femoral head in Sprague-Dawley rats

INTRODUCTION

Osteonecrosis of the femoral head (ONFH) is a disease in which the blood supply of the femoral head is interrupted or damaged, resulting in joint dysfunction. Hypoxic environments increase the expression of EPO, VEGF, and HIF causes vascular proliferation and increases the blood supply. It also causes the organism to be in a state of hypercoagulability and increases thrombosis. Therefore, the purpose of this study was to explore the occurrence of ONFH after the use of glucocorticoids (GCs) under conditions of hypoxia tolerance for a long time.

MATERIALS AND METHODS

Sprague-Dawley rats were fed in a hypobaric hypoxic chamber at an altitude of 4000 m, the whole blood viscosity, and plasma viscosity were determined to analyze the blood flow and hemagglutination. Western blotting, polymerase chain reaction, and immunohistochemistry were used to detect EPO, VEGF, CD31, and osteogenesis related proteins. Femoral head angiography was used to examine the local blood supply and micro-CT scanning was used to detect the structure of the bone trabecula.

RESULTS

Under hypoxic environments, the expression of EPO and VEGF increased, which increased the local blood supply of the femoral head, but due to more severe thrombosis, the local blood supply of the femoral head decreased.

CONCLUSIONS

Hypoxic environments can aggravate ONFH in SD rats; this aggravation may be related to the hypercoagulable state of the blood. We suggest that long-term hypoxia should be regarded as one of the risk factors of ONFH and we need to conduct a more extensive epidemiological investigation on the occurrence of ONFH in hypoxic populations.

Desferoxamine protects against glucocorticoid-induced osteonecrosis of the femoral head via activating HIF-1α expression

Glucocorticoid-induced osteonecrosis of the femoral head (GIOFH) is one of the most common complications of glucocorticoid administration. By chelating Fe²⁺ , desferoxamine (DFO) was reported to be able to activate the HIF-1α/VEGF pathway and promote angiogenesis. In the present study, we examined whether DFO administration could promote angiogenesis and bone repair in GIOFH. GIOFH was induced in rats by methylprednisolone in combination with lipopolysaccharide. Bone repair was assessed by histologic analysis and microcomputed tomography (micro-CT). Vascularization was assessed by Microfil perfusion and micro-CT analysis. Immunohistochemical staining was performed to analyze the expression of HIF-1α, VEGF, and CD31. Our in vivo study revealed that DFO increased HIF-1α/VEGF expression and promoted angiogenesis and osteogenesis in GIOFH. Moreover, our in vitro study revealed that DFO restored dexamethone-induced HIF-1α downregulation and angiogenesis inhibition. Besides, our in vitro study also demonstrated that DFO could protect bone marrow-derived stem cells from dexamethone-induced apoptosis and mitochondrial dysfunction by promoting mitophagy and mitochondrial fission. In summary, our data provided useful information for the development of novel therapeutics for management of GIOFH.

Hypoxia Signaling in the Skeleton: Implications for Bone Health

PURPOSE OF REVIEW

We reviewed recent literature on oxygen sensing in osteogenic cells and its contribution to development of a skeletal phenotype, the coupling of osteogenesis with angiogenesis and integration of hypoxia into canonical Wnt signaling, and opportunities to manipulate oxygen sensing to promote skeletal repair.

RECENT FINDINGS

Oxygen sensing in osteocytes can confer a high bone mass phenotype in murine models; common and unique targets of HIF-1α and HIF-2α and lineage-specific deletion of oxygen sensing machinery suggest differentia utilization and requirement of HIF-α proteins in the differentiation from mesenchymal stem cell to osteoblast to osteocyte; oxygen-dependent but HIF-α-independent signaling may contribute to observed skeletal phenotypes. Manipulating oxygen sensing machinery in osteogenic cells influences skeletal phenotype through angiogenesis-dependent and angiogenesis-independent pathways and involves HIF-1α, HIF-2α, or both proteins. Clinically, an FDA-approved iron chelator promotes angiogenesis and osteogenesis, thereby enhancing the rate of fracture repair.

Avascular necrosis of the femoral head in patients treated for leukaemia. Assessment of the need for a diagnostic protocol

OBJECTIVE

To evaluate the incidence of avascular necrosis of the hip in leukaemia patients treated in our hospital with high doses of corticosteroids in order to evaluate the necessity for an early detection protocol.

MATERIAL AND METHODS

Observational-descriptive and retrospective study from 2005 to 2016 of 253 patients diagnosed with paediatric leukaemia. Patients with musculoskeletal pathology were identified and patients with avascular necrosis were analysed.

RESULTS

A total of 26 patients (10%) had musculoskeletal symptoms. Three patients with avascular necrosis (1.2%) were analysed. One girl, 7 years old, was treated conservatively with traction - suspension and discharge. Two boys, an 11 and a 15.4 year-old,who developed graft-versus-host disease secondary to bone marrow transplantation, and whose treatment included high doses of corticosteroids, developed avascular necrosis of the hip. One was treated with bisphosphonates and forage and the other ended up with a total hip arthroplasty.

DISCUSSION

The occurrence of musculoskeletal symptoms during the treatment of leukaemia is different according to the bibliographic series (0.43 -12.6%). Some authors observe an increased risk in female patients between the ages of 10 and 17. A retrospective study reveals that there is a delay of 3.9 months in the diagnosis of CAP since the onset of pain. Other authors relate NAV to loading joints, age and high doses of corticosteroids.

CONCLUSION

Based on the low incidence of avascular necrosis of the hip in our 14-year-old population treated for leukaemia, the creation of diagnostic protocols seems not to be necessary. However, close monitoring of patients with potential risk factors recognized in the literature, is advisable.

HIF1A gene polymorphisms and human diseases: Graphical review of 97 association studies

Hypoxia-inducible factors (HIFs) belong to a family of transcription factors (TF) responsive to a low O2 availability, which is often a characteristic feature of solid tumors. The alpha subunit of the HIF heterodimer is O2 -sensitive, and once stabilized in hypoxia, it functions as a master regulator of various genes involved in hypoxia pathway. Changes in the HIF1A (hypoxia inducible factor 1, alpha subunit) nucleotide sequence or expression has been shown to be associated with the development of several diseases. Because of increasing research interest in HIF1A gene a review of association studies was needed. We here reviewed published data on single nucleotide polymorphisms (SNPs) in HIF1A in various diseases; in total, 34 SNPs were tested for an association with 49 phenotypes, and the results were visualized using the Cytoscape software. Among all collected polymorphisms 16 SNPs showed significant associations with 40 different phenotypes, including six SNPs associated with 14 cancer types. Missense SNPs (rs11549465 and rs11549467) within the oxygen-dependent degradation domain were most frequently studied. The study provides a comprehensive tool for researchers working in this area and may contribute to more accurate disease diagnosis and identification of therapeutic targets.

HIF1A (rs11549465) and AKNA (rs10817595) Gene Polymorphisms Are Associated with Primary Sjögren's Syndrome

Objective. To evaluate the allele and genotype frequencies of polymorphic sites of HIF1A and ANKA genes in primary Sjögren's syndrome (pSS). Methods. We included 110 patients with pSS and 141 ethnically matched healthy controls. Three HIF1A gene polymorphisms (Pro582Ser, Ala588Thr, and C191T) and two AKNA gene polymorphisms (−1372C>A and Pro624Leu) were genotyped using TaqMan probes in a Real-Time PCR instrument. Associations between pSS and genotypes, alleles, and inheritance models of the SNPs of interest were evaluated by logistic regression adjusted by age and gender. Results. The C/T genotype and the T allele of the HIF1A Pro582Ser polymorphism protected against pSS (OR = 0.22; 95% CI = 0.09–0.52; P < 0.01; OR = 0.26; 95% CI = 0.12–0.58; P < 0.01, resp.), whereas under a recessive model adjusted by age and gender, the AKNA −1372C>A polymorphism A/A genotype was associated with an increased risk of pSS (OR = 2.60; 95% CI = 1.11–6.12; P = 0.03). Conclusions. We identified HIF1A Pro582Ser T allele and C/T genotype as well as AKNA −1372C>A polymorphism A/A genotype as genetic factors associated with pSS. Further studies in other populations are needed to validate our findings and research is warranted in order to shed some light on their functional implications across biological pathways in this disease.

Role of HIF-1α signaling pathway in osteoarthritis: a systematic review

Osteoarthritis (OA) is the most common form of arthritis and is frequently diagnosed and managed in primary care; it is characterized by loss of articular hyaline cartilage, which is a unique connective tissue that physiologically lacks blood vessels. Articular cartilage survives in a microenvironment devoid of oxygen, which is regulated by hypoxia inducible factor (HIF-1α). HIF-1α is considered the main transcriptional regulator of cellular and developmental response to hypoxia. To date, the relevance of HIF-1α in the assessment of cartilage has increased since its participation is essential in the homeostasis of this tissue. Taking into account the new emerging insights of HIF-1α in the scientific literature in the last years, we focused the present review on the potential role of HIF-1α signaling pathway in OA development, especially in how some genetic factors may influence the maintenance or breakdown of articular cartilage.

Polymorphic variation of hypoxia inducible factor-1 A (HIF1A) gene might contribute to the development of knee osteoarthritis: a pilot study

Background

Osteoarthritis (OA) is a multifactorial degenerative condition of the whole joint with a complex pathogenesis whose development and progression is significantly mediated by interactions between the joint cartilage and articular tissues, particularly, proinflammatory mediators and oxidative stress, which results in cartilage deterioration and subchondral bone destruction. HIF-1 alpha regulates oxygen homeostasis in hypoxic tissues such as joint cartilage; efficiency of transcriptional activity of the HIF1A gene is strongly influenced by the presence of polymorphic variants. Given the loss of articular cartilage and with intention to restore damaged tissue, WISP-1 participates in the development of subchondral bone; further, its expression is highly increased in chondrocytes of OA patients. The aim of this study was to evaluate gene frequencies of HIF1A and WISP1 polymorphisms in Mexican patients suffering from knee OA.

Methods

We determined HIF1A rs11549465 (P582S), rs11549467 (A588T), and rs2057482 (C191T), and WISP1 rs2929970 (A2364G) polymorphisms in 70 Mexican patients with knee OA and compare them to those present in 66 ethnically matched healthy controls. Genotyping for these polymorphisms was performed by Real-Time PCR using TaqMan probes.

Results

Gene frequencies exhibited a significant increase of the CC genotype of rs11549465 polymorphism in knee OA patients as compared with those present in controls (P = 0.003 OR = 5.7, 95 % CI = 1.7–21.6); CT genotype and T allele showed decreased frequency in the knee OA group vs. the controls (P = 0.003 OR = 0.2, CI = 0.05–0.6; and P = 0.004 OR = 0.2, CI = 0.05–0.65, respectively). Allele frequencies of the other polymorphic variants were similar in both patients and controls.

Conclusions

These results suggest that the presence of the rs11549465 SNP (HIF1A) plays a role protective in the loss of articular cartilage in our population, and offers the possibility to further study the molecular mechanisms within cartilage and subchondral bone.

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-015-0678-z) contains supplementary material, which is available to authorized users.

Genetic variation in the coagulation factor V gene and risk of femoral head osteonecrosis

Osteonecrosis of the femoral head (ONFH) is characterized by the death of the cellular portion of the femoral head due a reduction or disruption in the blood supply. Certain studies have implicated coagulation disorders, including thrombophilia and hypofibrinolysis, in the pathogenesis of ONFH. The factor V (F5) Leiden mutation has been suggested to be a genetic risk factor for venous thromboembolism and osteonecrosis in Caucasian individuals, however, this association remains controversial in other populations. The present study aimed to identify polymorphisms of the F5 gene and performed a case‑control study in a Korean population. The F5 gene was sequenced in 24 unrelated Korean individuals, and 16 polymorphisms were detected. A total of six polymorphisms were genotyped in 423 patients with ONFH and 348 control individuals. Analysis of the association between genotyped single nucleotide polymorphisms and haplotypes and with ONFH was performed. Comparison of the ONFH samples and the control individuals using logistic regression models revealed no statistically significant difference in the frequencies of the F5 polymorphisms and haplotypes. These findings suggested that F5 polymorphisms were not significant in the susceptibility to ONFH in the Korean population.

HIF-1α polymorphism in the susceptibility of cervical spondylotic myelopathy and its outcome after anterior cervical corpectomy and fusion treatment

Background

To investigate the association between the single nucleotide polymorphism (SNP) of hypoxia-inducible factor1 α (HIF-1α) and the susceptibility to cervical spondylotic myelopathy (CSM) and its outcome after surgical treatment.

Method

A total of 230 CSM patients and 284 healthy controls were recruited. All patients received anterior cervical corpectomy and fusion (ACF) and were followed for 12 months. The genotypes for two HIF-1α variants (1772C>T and 1790G>A) were determined.

Results

In the present study, we found that the HIF-1α polymorphism at 1790G>A significantly affects the susceptibility to CSM and its clinical features, including severity and onset age. In addition, the 1790A>G polymorphism also determines the prognosis of CSM patients after ACF treatment. The GG genotype of 1790G>A polymorphism is associated with a higher risk to develop CSM, higher severity and earlier onset age. More importantly, we found that the 1790G>A polymorphism determines the clinical outcome in CSM patients who underwent ACF treatment.

Conclusion

Our findings suggest that the HIF-1α 1790G>A polymorphism is associated with the susceptibility to CSM and can be used as predictor for the clinical outcome in CSM patients receiving ACF treatment.

An association study between hypoxia inducible factor-1alpha (HIF-1α) polymorphisms and osteonecrosis

Bone hypoxia resulting from impaired blood flow is the final pathway for the development of osteonecrosis (ON). The aim of this study was to evaluate if HIF-1α, the major transcription factor triggered by hypoxia, is genetically implicated in susceptibility to ON. For this we analyzed frequencies of three known HIF-1α polymorphisms: one in exon 2 (C111A) and two in exon 12 (C1772T and G1790A) and their association with ON in a Greek population. Genotype analysis was performed using PCR-RFLP and rare alleles were further confirmed with sequencing. We found that genotype and allele frequency of C1772T and G1790A SNP of HIF-1α (SNPs found in our cohort) were not significantly different in ON patients compared to control patients. Furthermore these SNPs could not be associated with the different subgroups of ON. At the protein level we observed that the corresponding mutations (P582S and A588T, respectively) are not significant for protein function since the activity, expression and localization of the mutant proteins is practically indistinguishable from wt in HEK293 and Saos-2 cells. These results suggest that these missense mutations in the HIF-1α gene are not important for the risk of developing ON.

Genetic risk factors for glucocorticoid-induced osteonecrosis: a meta-analysis

Glucocorticoid-induced osteonecrosis is a common and severe adverse event. We conducted a meta-analysis to investigate whether polymorphisms in target genes were associated with the risk of corticosteroid-induced osteonecrosis. Published literature from PubMed and EMBASE were searched for eligible publications. Pooled odds ratio (OR) and 95% confidence interval (CI) were calculated using a fixed- or random-effects model. There were 23 articles with 35 genes described the relationship between polymorphisms and glucocorticoid-induced osteonecrosis. Meta-analyses were carried out for those SNPs with three or more eligible studies, which included four SNPs located in three genes (PAI-1, MTHFR, ABCB1). The meta-analysis revealed that the PAI-1 4G allele was associated with an increased risk of osteonecrosis compared with the 5G allele (combined studies: OR=1.932, 95% CI=1.145-3.261). The OR for the 4G/4G vs. 5G/5G genotype of PAI-1 was 3.217 (95% CI 1.667-6.209 with combined studies), The relative risk of osteonecrosis was increased in the 4G allele vs. 5G/5G and 4G/4G genotype vs. 5G allele, with odds ratios of 2.304 (95% CI=1.235-4.299) and 2.307 (95% CI=1.527-3.485) in combined studies, respectively. The ABCB1 C3435T genotype distributions available confirmed that the C allele increased osteonecrosis risk compared with the T allele (OR 1.668, 95% CI=1.214-2.293) and TT genotype (OR 2.946, 95% CI=1.422-6.101). There was no evidence for significant association between MTHFR C677T and ABCB1 G2677T/A polymorphisms and risk of osteonecrosis. Results of this meta-analysis indicate that the PAI-1 4G/5G and ABCB1 C3435T polymorphisms may be risk factors for osteonecrosis.

Common polymorphisms in angiogenesis

A wide variety of diseases have a significant genetic component, including major causes of morbidity and mortality in the western world. Many of these diseases are also angiogenesis dependent. In humans, common polymorphisms, although more subtle in effect than rare mutations that cause Mendelian disease, are expected to have greater overall effects on human disease. Thus, common polymorphisms in angiogenesis-regulating genes may affect the response to an angiogenic stimulus and thereby affect susceptibility to or progression of such diseases. Candidate gene studies have identified several associations between angiogenesis gene polymorphisms and disease. Similarly, emerging pharmacogenomic evidence indicates that several angiogenesis-regulating polymorphisms may predict response to therapy. In contrast, genome-wide association studies have identified only a few risk alleles in obvious angiogenesis genes. As in other traits, regulatory polymorphisms appear to dominate the landscape of angiogenic responsiveness. Rodent assays, including the mouse corneal micropocket assay, tumor models, and a macular degeneration model have allowed the identification and comparison of loci that directly affect the trait. Complementarity between human and animal approaches will allow increased understanding of the genetic basis for angiogenesis-dependent disease.

Clinical analysis of osteonecrosis of the femoral head induced by steroids

OBJECTIVE

To explore the clinical characteristics of osteonecrosis of the femoral head (ONFH) induced by steroids.

METHODS

From January 2000 to October 2009, 497 hips in 270 cases of ONFH induced by steroids were studied. A questionnaire was administered when the patients were admitted; the questions concerned the underlying disease, duration of steroid usage, total dosage of steroid, incubation period (time interval between commencement of steroid therapy and onset of pain), severity of pain, location of initial complaint, primary diagnosis, time lag from onset of pain to final diagnosis and physical signs when admitted. The correlations between pain and Association Research Circulation Osseous (ARCO) stage, bone marrow edema (BME) and lesion size were analyzed.

RESULTS

The median of time between commencing steroid medication and developing ONFH for the 269 cases was 18 months (range, 2-384 months). 78.82% cases presented with pain within three years of steroid initiation, only 10.41% patients first complained of pain six or more years after commencing steroid therapy. Fifty-six cases (20.82%) were misdiagnosed, lumbar disorders being the most frequent misdiagnoses. 79.29% of symptomatic hips presented with abnormal physical tests. Of 420 symptomatic hips, 166 hips were type C1, 223 hips type C2; 299 hips had collapsed; and there was BME in 209 hips.

CONCLUSION

Most patients with ONFH induced by steroids complained of pain within 3 years of commencing steroid therapy. Pain was associated with lesion size, collapse and BME. Atypical location of pain, failure to perform a physical examination and MRI findings were the main causes of misdiagnoses.

Significant associations of PAI-1 genetic polymorphisms with osteonecrosis of the femoral head

BACKGROUND

The pathogenesis of osteonecrosis of the femoral head (ONFH) has been implicated in hypofibrinolysis and blood supply interruption. Previous studies have demonstrated that decreased fibrinolytic activity due to elevated plasminogen activator inhibitor-1 (PAI-1) levels correlates with ONFH pathogenesis. The -675 4G/5G single nucleotide polymorphism (SNP rs1799889) in the PAI-1 gene promoter is associated with PAI-1 plasma level. We investigated whether rs1799889 and two other SNPs of the PAI-1 gene (rs2227631, -844 G/A in the promoter; rs11178, +10700 C/T in the 3'UTR) are associated with increased ONFH risk.

METHODS

Three SNPs in PAI-1 were genotyped in 206 ONFH patients and 251 control subjects, using direct sequencing and a TaqMan® 5' allelic discrimination assay. We performed association analysis for genotyped SNPs and haplotypes with ONFH.

RESULTS

The 4G allele of rs1799889, A allele of rs2227631, and C allele of rs11178 were significantly associated with increased ONFH risk (p = 0.03, p = 0.003, and p = 0.002, respectively). When we divided the population according to gender, an association between the three SNPs and increased risk of ONFH was found only in men. In another subgroup analysis based on the etiology of ONFH, rs2227631 (A allele) and rs11178 (C allele) in the idiopathic subgroup (p = 0.007 and p = 0.021) and rs1799889 (4G allele) and rs11178 (C allele) in the alcohol-induced subgroup (p = 0.042 and p = 0.015) were associated with increased risk of ONFH. In addition, a certain haplotype (A-4G-C) of PAI-1 was also significantly associated with ONFH (p < 0.001).

CONCLUSION

Our findings demonstrated that three SNPs (rs1799889, rs2227631, and rs11178) of the PAI-1 gene were associated with ONFH risk. This study also suggests that PAI-1 SNPs may play an important role in ONFH.

Polymorphisms of the hypoxia-inducible factor 1 gene and peripheral artery disease

Hypoxia-inducible factor 1 (HIF1) is a key regulator of angiogenesis and is involved in inflammation, which are two important features of the pathogenesis of peripheral artery disease (PAD). The gene for the HIF1-alpha subunit (HIF1A) carries two common mis-sense mutations, P582S (C>T, rs11549465) and A588T (G>A, rs11549467), which both have been related to increased trans-activation capacity of HIF1-alpha. The aim of the present study was to analyze the role of these polymorphisms in PAD. The study was designed as a case-control study including 917 patients with documented PAD and 969 control subjects. HIF1A genotypes were determined by exonuclease (TaqMan) assays. HIF1A P582S genotype frequencies were not significantly different between PAD patients (PP 82.2%; PS 16.5%; SS 1.3%) and control subjects (83.2%; 15.3%; 1.5%; p = 0.72). Similarly, HIF1A A588T genotype frequencies did not differ significantly between PAD patients (AA 95.9%; AT 4.1%) and control subjects (AA 96.8%; AT 3.2%; p = 0.28). In a multivariate logistic regression analysis including age, sex, smoking, diabetes, arterial hypertension and hypercholesterolemia, neither the HIF1A P582S polymorphism (odds ratio: 1.26; 95% confidence interval 0.92-1.74; p = 0.16) nor the A588T polymorphism (odds ratio: 1.17; 95% confidence interval 0.59-2.35; p = 0.66) was significantly associated with the presence of PAD. Both polymorphisms were furthermore not associated with age at onset of PAD, Fontaine stage of the disease or the ankle/brachial index of patients. We conclude that functional polymorphisms in the HIF1A gene do not contribute to susceptibility to PAD.

Nationwide epidemiologic survey of idiopathic osteonecrosis of the femoral head

BACKGROUND

Although numerous studies describe the clinical characteristics of idiopathic osteonecrosis of the femoral head (ONFH) in specific study populations, these have not been confirmed in countrywide studies.

QUESTIONS/PURPOSES

We therefore determined: (1) the annual number of patients seeking medical care and number of patients newly diagnosed; and (2) the distribution of the age and gender of the patients, potential causative factors, severity of the disease, and operative procedures performed.

PATIENTS AND METHODS

We conducted a nationwide epidemiologic survey in 2005. The survey included all orthopaedic departments in Japan by stratified random sampling according to the number of beds.

RESULTS

The number of patients who sought medical care for idiopathic ONFH during 2004 was estimated to be 11,400 (95% confidence interval, 10,100-12,800). We obtained clinical information from 1502 of these patients. The peak in age distribution occurred in the 40s. Potential causative factors were systemic steroid administration (51%) and habitual alcohol use (31%). Hip replacement was the most frequently performed procedure (65%). Among patients with a history of systemic steroid administration, systemic lupus erythematosus was reported most frequently (31%) as the underlying disease. Among patients younger than 40 years, steroid use was the most prominent potential causative factor (60%), and hip replacement frequently was performed (45%). A greater proportion of patients with no history of steroid or alcohol use was observed among patients 65 years or older (41%).

CONCLUSIONS

In addition to the disease burden of idiopathic ONFH in Japan, our results confirmed the importance of developing preventive and treatment strategies, especially among the younger population.

LEVEL OF EVIDENCE

Level IV, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

Genetic association of angiogenesis- and hypoxia-related gene polymorphisms with osteonecrosis of the femoral head

Multiple factors have been implicated in the development of osteonecrosis of the femoral head (ONFH). In particular, non-traumatic ONFH is directly or indirectly related to injury of the vascular supply to the femoral head. Thus, hypoxia in the femoral head caused by impaired blood flow may be an important risk factor for ONFH. In this study, we investigated whether genetic variations of angiogenesis- and hypoxia-related genes contribute to an increased risk for the development of ONFH. Candidate genes were selected based on known hypoxia and angiogenesis pathways. An association study was performed using an Affymetrix Targeted Genotyping 3K Chip array with 460 ONFH patients and 300 control subjects. We showed that single nucleotide polymorphisms (SNPs) in the genes TF, VEGFC, IGFBP3, and ACE were associated with an increased risk of ONFH. On the other hand, SNPs in the KDR and NRP1 genes were associated with protection against ONFH. The most important finding was that one SNP (rs2453839) in the IGFBP3 gene was significantly associated with a higher risk of ONFH (P=0.0061, OR 7.74). In subgroup analysis, most candidate gene variations that were associated with ONFH occurred in the idiopathic subgroup. Among other SNPs, ACE SNPs were associated with steroid-induced ONFH (P=0.0018-0.0037, OR>3). Collectively, our findings suggest that genetic variations in angiogenesis- and hypoxia-related genes may help to identify susceptibility factors for the development of ONFH in the Korean population.

Polymorphisms in the Annexin gene family and the risk of osteonecrosis of the femoral head in the Korean population

OBJECTIVE

The pathogenesis of osteonecrosis of the femoral head (ONFH) probably reflects multiple etiologies. Recent studies have explored associations between genetic mutations and/or polymorphisms and ONFH. Annexins (ANXs) have been implicated in many physiological functions, including blood coagulation, inflammation, apoptosis, as well as Ca(2+) homeostasis in bone cells, all of which may be associated with ONFH. The aim of this study was to evaluate the possible association of AnnexinA (ANXA) family gene polymorphisms with ONFH.

METHODS

52 SNPs from three genes of the ANXA family were selected from public databases and genotyped in 443 ONFH patients and 273 control subjects using the Affymetrix Targeted Genotyping 3 K Chip array. The association analysis of genotyped SNPs and haplotypes was performed with ONFH.

RESULTS

Among the polymorphisms tested of the ANXA family gene, the rs9324679, rs9324677, rs10037814, and rs11960458 SNPs of the ANXA6 gene were significantly associated with the risk of ONFH in all alternative analysis models (p range; 0.0007-0.049, odds ratio (OR); 0.63-1.72). Further analysis stratified by pathological etiology showed that these SNPs were also associated with the risk of ONFH in at least one subgroup (p range; 0.0017-0.049). Haplotype association analysis showed that several haplotypes were significantly associated with a risk of ONFH, with p values ranging between 0.0005 and 0.049 (OR range; 0.44-1.76).

CONCLUSIONS

These findings indicate that the polymorphisms of ANXA6 are associated with ONFH. Thus, these polymorphisms may be useful genetic markers to identify high-risk individuals.

Distribution of TRAP-positive cells and expression of HIF-1alpha, VEGF, and FGF-2 in the reparative reaction in patients with osteonecrosis of the femoral head

Osteogenesis and angiogenesis are closely associated with the reparative process in bone. In osteonecrosis of the femoral head (ONFH), although the progression of bone resorption by osteoclasts is considered to be followed by femoral head collapse, the reparative reaction remains unknown. In order to investigate the reparative reaction in patients with ONFH, the distribution of TRAP- positive cells and expression of HIF-1alpha, VEGF, and FGF-2 were observed in 51 hips in 42 patients. TRAP-positive cells were detected around the teres insertion and retinaculum in the early radiologic stage, and increased around the new trabecular bone throughout the reparative interface zone in the late collapsed stage. HIF-1alpha expression was detected at the fibrosis area and the transitional area, which included the proximal area of the reparative interface zone adjacent to the necrotic zone. VEGF was expressed at the edematous area of the reparative interface zone, while FGF-2 was detected widely in the reparative interface zone and the normal zone. In the late radiologic stages, HIF-1alpha, VEGF, and FGF-2 were not detected in the necrotic zone, and they acted in angiogenesis in the reparative interface zone, while TRAP-positive cells increased around the new bone formation in response to remodeling after the collapse.

Genetic association study of polymorphisms in the catalase gene with the risk of osteonecrosis of the femoral head in the Korean population

OBJECTIVE

Osteonecrosis (ON) of the femoral head frequently leads to progressive collapse of the femoral head followed by degenerative arthritis of the hip joint. Oxidative stress, which has been implicated in many pathological conditions, including vascular injury, recently has been suggested to play a part in the development of ON. Catalase (CAT) is a major antioxidant enzyme and a number of polymorphisms in the CAT have been described as being associated with several diseases, such as hypertension, diabetes mellitus, Alzheimer's disease, and vitiligo. The aim of this study was to evaluate the association of CAT gene polymorphisms with ON of the femoral head (ONFH) in a case-control study.

METHODS

Eight polymorphic sites of CAT were selected from public databases, and genotyped in 443 ONFH patients and 273 control subjects using the Affymetrix Targeted Genotyping (TG) 3K chip array. The association analysis of genotyped single nucleotide polymorphisms (SNPs) and haplotypes was performed with ONFH.

RESULTS

The -89A>T, -20T>C, +3033C>T, +14539A>T, +22348C>T, and +24413T>C polymorphisms of the CAT gene were significantly associated with the risk of ONFH in all alternative analysis models (P range; 0.0001-0.035, odds ratio [OR]: 0.52-3.47). Particularly, the minor allele of -89A>T, -20T>C and +3033C>T had a protective effect on ONFH with significance (P range: 0.0014-0.035, OR: 0.52-0.73). Further analysis based on pathological etiology showed that the genotypes of -89A>T, -20T>C, +3033C>T, +14539A>T, and +22348C>T, and +24413T>C were also associated with the risk of ONFH in each subgroup with significant P values.

CONCLUSIONS

These findings indicate that the polymorphisms of CAT are associated with the ONFH, and suggest that oxidative stress may play an important role in the pathogenesis of ONFH.

Chemotherapy-associated osteonecrosis in cancer patients with solid tumours: a systematic review

Non-traumatic osteonecrosis of bone is recognized as a potential complication in solid-tumour cancer patients receiving treatment with cytotoxic chemotherapy. This review summarizes recent reports of osteonecrosis associated with chemotherapy in cancer patients, and describes the possible underlying pathophysiology and options available for its diagnosis, prevention and treatment. Fifty-four reported cases of non-traumatic osteonecrosis in adult patients with solid tumours receiving chemotherapy were identified by searching for reports in the medical literature. Osteonecrosis was observed most commonly in men receiving chemotherapy for testicular cancer. Osteonecrosis was also seen in patients receiving chemotherapy for breast, ovarian, small-cell lung cancer and osteosarcoma. Most patients had received corticosteroids, had femoral head involvement and had delayed onset of osteonecrosis. It appears that patients at higher risk for osteonecrosis with chemotherapy are identifiable. As the long-term survival of patients with solid tumours receiving chemotherapy increases, the prevalence of treatment-related osteonecrosis may also increase. Patients should be informed that osteonecrosis is a potential complication of cancer treatment. Measures to reduce risk should be taken, and patients should be monitored for early symptoms. Routine screening for chemotherapy-associated osteonecrosis is not recommended; however, a high index of clinical suspicion in patients at risk may allow for early intervention and preservation of the joints.