Elevated plasma cartilage oligomeric matrix protein (COMP) level are associated with the progression of non-traumatic osteonecrosis of femoral head

Serum β-catenin changes vary among different stages of osteonecrosis of the femoral head: an exploratory biomarker study

BACKGROUND

Wnt/β-catenin signaling pathway is closely related to the pathogenesis Osteonecrosis of the femoral head (ONFH). β-catenin, as a major component of Wnt signaling pathway, plays a vital role in the proliferation of osteoblasts. But the effect of altering β-catenin level on the early diagnosis and staging of ONFH has not been studied. Our purpose is to investigate the role of β-catenin level in the progress of ONFH.

METHOD

One hundred and one patients with three stages of ONFH and fifty healthy controls were recruited between May 2016 and November 2016. We divided the patients into 32 cases of stage II, 41 cases of stage III and 28 cases of stage IV according to the Association Research Circulation Osseous (ARCO) classification. We evaluated the clinical bone histomorphology, expression position and level of β-catenin as well as the plasma β-catenin level. We investigated the level of β-catenin from the serum and tissue samples using ELISA and Western Blot assay. We also evaluated the expression of β-catenin in bone tissue by immunohistochemistry. Data were analyzed by independent t-test and ANOVA.

RESULTS

We found that the mean (± SD) serum level of β-catenin was 66.99 ± 3.032 ng/ml in the ONFH patients, which was higher than 20.14 ± 1.715 ng/ml observed in the control group (P < 0.001). Moreover, the β-catenin levels were 49.30 ± 4.649 ng/ml, 72.54 ± 4.864 ng/ml and 79.10 ± 4.773 ng/ml in the ONFH patients with ARCO stage II, stage III and stage IV respectively, showing significant difference among them (P < 0.001). We also found that the area under the curve (AUC) calculated by ROC curve analysis to determine the values for β-catenin levels in ONFH compared with those in the control group was 0.9358 (P < 0.001), where the sensitivity was 77.23% and specificity was 98.00%.

CONCLUSION

Our results indicate that the increased β-catenin may play a vital role in the progress of ONFH and the level of β-catenin is correlated with ARCO stages. The cut-off concentration may be used as one of the sensitive marks to assess the disease process of ONFH.

Blood biomarkers related to osteonecrosis of femoral head by internal fixation after Garden I femoral neck fracture: a cohort study

BACKGROUND

Internal fixation is currently considered the gold standard in treatment for femoral neck fractures in adults. However, osteonecrosis of the femoral head (ONFH) after internal fixation would occur in quite proportion of patients with femoral neck fracture, even in Garden I femoral neck fracture. The purpose of this study was to determine the association between the blood biomarkers (serum albumin, pre-albumin, total protein and total lymphocyte count) and ONFH following internal fixation of Garden I femoral neck fracture in adults.

METHOD

This is a single center cohort study, in which each patient who sustained a Garden I femoral neck fracture had been treated with internal fixation, and had adequate preoperative blood examinations. The serum albumin was categorized as ≥ 40g/L or < 40g/L. The pre-albumin was categorized as ≥ 22mg/dL or < 22mg/dL. The total protein was categorized as ≥ 65g/L or < 65 g/L. The total lymphocyte count was categorized as ≥1.1× 10⁹ /L or <1.1×10⁹ /L. Multivariate cox proportional hazards analysis was used to assess the association between blood markers and the osteonecrosis of femoral head during the 2-years follow-up period controlling the confounders.

RESULT

A total of 10 cases of ONFH were identified. Multivariate Cox regression analysis revealed that low total lymphocyte count and hypertension state were significant independent risk factors for ONFH after internal fixation for Garden I femoral head fractures.

CONCLUSION

Blood biomarkers were potential predictors for ONFH after internal fixation Garden I femoral neck fractures. We suggest that routine laboratory tests might can be used to assist surgeons to identify patients at great risk of ONFH.

Description of Joint Alterations Observed in a Family Carrying p.Asn453Ser COMP Variant: Clinical Phenotypes, In Silico Prediction of Functional Impact on COMP Protein and Stability, and Review of the Literature

The role of genetics in the development of osteoarthritis is well established but the molecular bases are not fully understood. Here, we describe a family carrying a germline mutation in COMP (Cartilage Oligomeric Matrix Protein) associated with three distinct phenotypes. The index case was enrolled for a familial form of idiopathic early-onset osteoarthritis. By screening potential causal genes for osteoarthritis, we identified a heterozygous missense mutation of COMP (c.1358C>T, p.Asn453Ser), absent from genome databases, located on a highly conserved residue and predicted to be deleterious. Molecular dynamics simulation suggests that the mutation destabilizes the overall COMP protein structure and consequently the calcium releases from neighboring calcium binding sites. This mutation was once reported in the literature as causal for severe multiple epiphyseal dysplasia (MED). However, no sign of dysplasia was present in the index case. The mutation was also identified in one of her brothers diagnosed with MED and secondary osteoarthritis, and in her sister affected by an atypical syndrome including peripheral inflammatory arthritis of unknown cause, without osteoarthritis nor dysplasia. This article suggests that this mutation of COMP is not only causal for idiopathic early-onset osteoarthritis or severe MED, but can also be associated to a broad phenotypic variability with always joint alterations.

[Clinical significance of different imaging manifestations of osteonecrosis of femoral head in the peri-collapse stage]

Objective

To explore the different imaging manifestations of osteonecrosis of the femoral head (ONFH) and their correlation with the occurrence of pain during the peri-collapse period.

Methods

The 372 patients (624 hips) with ONFH in the peri-collapse stage who were admitted between December 2016 and October 2019 and met the selection criteria were selected as the research objects. Among them, there were 270 males and 102 females, with an average age of 35.3 years (mean, 15-65 years). There were 120 cases of unilateral hip and 252 cases of bilateral hips. There were 39 cases (39 hips) of traumatic ONFH, 196 cases (346 hips) of hormonal ONFH, 102 cases (178 hips) of alcoholic ONFH, and 35 cases (61 hips) of idiopathic ONFH. Among them, there were 482 hips with pain symptoms and 142 hips without pain. The pain duration was less than 3 months in 212 hips, 3-6 months in 124 hips, 6-12 months in 117 hips, and more than 12 months in 29 hips. According to the Association Research Circulation Osseous (ARCO) staging, the ONFH was rated as stage Ⅱ in 325 hips and stage Ⅲ in 299 hips. The patients were grouped according to ONFH etiology and ARCO staging, and hip joint pain and X-ray film (crescent sign and cystic changes), CT (subchondral bone fractures and cystic changes), and MRI (bone marrow edema, joint effusion, and subchondral hypointensity zone) were compared. Spearman rank correlation was used to determine the correlation between ONFH pain duration and X-ray film, CT, and MRI imaging manifestations.

Results

There were significant differences ( P<0.05) between ONFH patients with different etiologies in crescent sign on X-ray film, subchondral bone fracture on CT, and joint effusion on MRI. And there were significant differences ( P<0.05) between ONFH patients with different ARCO stages in hip pain duration and all imaging manifestations. Correlation analysis showed that the pain duration of ONFH patients was correlated with all imaging manifestations ( P<0.05). The cystic change on CT was correlated with the subchondral hypointensity zone and joint effusion grade on MRI, and subchondral hypointensity zone and joint effusion grade on MRI were also correlated ( P<0.05).

Conclusion

The cystic changes, subchondral hypointensity zone, and joint effusion are closely related to the collapse of the femoral head and hip pain in patients with ONFH in the peri-collapse stage. The above-mentioned signals in stage Ⅱ ONFH indicate the instability of the femoral head, which is to predict the development of ONFH and the rational choice of hip-preserving treatment methods provides a basis.

Proteomics analysis of hip articular cartilage identifies differentially expressed proteins associated with osteonecrosis of the femoral head

OBJECTIVE

The cartilage degeneration that accompanies subchondral bone necrosis plays an important role in the development of osteonecrosis of femoral head (ONFH). To better understand the molecular basis of cartilage degradation in ONFH, we compared the proteomic profiles of ONFH cartilage with that of fracture control.

DESIGN

Hip cartilage samples were collected from 16 ONFH patients and 16 matched controls with femoral neck fracture. Proteomics analysis was conducted using tandem mass tag-based quantitation technique. Gene ontology (GO) analysis, KEGG pathway and protein-protein interaction analysis were used to investigate the functions of the altered proteins and biological pathways. Differentially expressed proteins including alpha-2-HS-glycoprotein (AHSG) and Cytokine-like protein 1 (Cytl1) were validated by Western blot (WB) and immunohistochemistry (IHC).

RESULTS

303 differentially expressed proteins were identified in ONFH cartilage with 72 up-regulated and 231 down-regulated. Collagen turnover, glycosaminoglycan biosynthesis, metabolic pathways, and complement and coagulation cascades were significantly modified in ONFH cartilage. WB and IHC confirmed the increased expression of AHSG and decreased expression of Cytl1 in ONFH cartilage.

CONCLUSIONS

Our results reveal the implication of altered protein expression in the development of ONFH, and provide novel clues for pathogenesis studies of cartilage degradation in ONFH.

Osteoclastic activity was associated with the development of steroid-induced osteonecrosis of femoral head

This study is focussed on evaluating and comparing two mediators of osteoclast, osteoprotegerin (OPG) and nuclear factor-κB ligand (RANKL), in plasma and tissue levels in patients with steroid-induced osteonecrosis of femoral head (SIONFH). Subjects were included in this cross-sectional case-control study in 2016. Bone histomorphology, immunohistochemistry, Western blotting, OPG and RANKL plasma levels, post-hoc statistical power and receiver-operating characteristic (ROC) curves were evaluated. Eighty-six patients diagnosed with SIONFH and 51 healthy subjects were included. OPG expression levels in bone samples increased with ARCO stage, and RANKL expression levels decreased with ARCO stages. Plasma OPG and RANKL levels were significantly higher in the SIONFH group compared with the healthy control group. The plasma OPG level and ratio of OPG and RANKL were positively associated with ARCO stages and significantly higher in stages III and IV. Plasma RANKL levels were negatively associated with ARCO stage and were significantly higher in ARCO stages II and III. Plasma OPG and RANKL may represent potential biomarkers during SIONFH at different stages. Higher plasma OPG levels indicated late-stage SIONFH, and higher plasma RANKL levels indicated early stage. Our findings may provide a clue for the development of diagnostic tools and therapies for SIONFH.