[Transcriptome data mining combined with clinical and animal experiments for identification of syndrome element marker genes during entire course of steroid-induced osteonecrosis of femoral head].

A research strategy combining transcriptome data mining and experimental verification was adopted to identify the marker genes characterizing the syndrome elements of phlegm, stasis, and deficiency in steroid-induced osteonecrosis of the femoral head(SONFH). Firstly, the common differentially expressed gene sets of SONFH with the syndromes of phlegm-stasis obstructing collaterals, vessel obstruction, and liver-kidney deficiency were obtained from the clinical transcriptomic analysis of a previous study. The differential expression trend analysis and functional gene mining were then employed to predict the candidate marker gene sets representing phlegm, stasis, and deficiency. The whole blood samples from SONFH patients, whole blood samples from SONFH rats, and affected femoral head tissue samples were collected for qPCR, which aimed to determine the expression levels of the candidate marker genes mentioned above. Furthermore, the receiver operating characteristic curve(ROC) was established to objectively evaluate the syndrome differentiation effectiveness of the candidate marker genes mentioned above. The transcriptome data analysis results showed that the candidate marker genes for phlegm was ELOVL fatty acid elongase 6(ELOVL6), and those for stasis were ankyrin 1(ANK1), glycophorin A/B(GYPA/B), and Rh-associated glycoprotein(RHAG). The candidate marker genes for deficiency were solute carrier family 2 member 1(SLC2A1) and stomatin(STOM). The qPCR results showed that compared with that in the non-SONFH group, ELOVL6 had the lowest expression level in the peripheral blood of the SONFH patients with the syndrome of phlegm-stasis obstructing collaterals(P<0.05). Compared with that in the normal control group, ELOVL6 had the lowest expression level in the peripheral blood and affected femoral head tissue of SONFH rats modeled for 4 weeks(P<0.01), and it showed better syndrome differentiation effectiveness of rats modeled for 4 weeks(AUC=0.850, P=0.006) than at other modeling time points(8, 12, 16, and 21 weeks, AUC of 0.689, 0.766, 0.588, and 0.662, respectively). Compared with that in the non-SONFH group, the expression levels of ANK1, GYPA, and RHAG were the lowest in the peripheral blood of SONFH patients with the vessel obstruction syndrome(P<0.05). The expression levels of the three genes were the lowest in the peripheral blood and affected femoral head tissue of SONFH rats modeled for 12 weeks(P<0.05, P<0.01), and their syndrome differentiation effectiveness in the rats modeled for 12 weeks(GYPA: AUC=0.861, P=0.012; ANK1: AUC=0.855, P=0.006; RHAG: AUC=0.854, P=0.009) was superior to that for 4, 8, 16, and 21 weeks(GYPA: AUC=0.646, 0.573, 0.691, and 0.617, respectively; ANK: AUC1=0.630, 0.658, 0.657, and 0.585, respectively; RHAG: AUC=0.592, 0.511, 0.515, and 0.536, respectively). Compared with the non-SONFH group, both SLC2A1 and STOM had the lowest expression levels in the peripheral blood of patients with the syndrome of liver and kidney deficiency(P<0.05). Compared with the normal control group, their expression levels were the lowest in the peripheral blood and affected femoral head tissue of SONFH rats modeled for 21 weeks(P<0.05, except STOM in the peripheral blood of rats). Moreover, the syndrome differentiation effectiveness of SLC2A1 in the rats modeled for 21 weeks(AUC=0.806, P=0.009) was superior to that for 4, 8, 12, and 16 weeks(AUC=0.520, 0.580, 0.741, 0.774, respectively), and STOM was meaningless in syndrome differentiation. In summary, the candidate marker gene for phlegm in SONFH is ELOVL6; the candidate marker genes for stasis are GYPA, RHAG, and ANK1; the candidate marker gene for deficiency is SLC2A1. The results help to reveal the biological connotations of phlegm, stasis, and deficiency in SONFH at the genetic level.

TRIM21 silencing inhibits the apoptosis and expedites the osteogenic differentiation of dexamethasone­induced MC3T3­E1 cells by activating the Keap1/Nrf2 pathway.

Steroid-induced osteonecrosis of the femoral head (ONFH) is a serious complication caused by long-term or excessive use of glucocorticoids. The present study aimed to ascertain the effects of tripartite motif-containing protein 21 (TRIM21) on the process of steroid-induced ONFH and its hidden action mechanism. TRIM21 expression in dexamethasone (Dex)-treated mouse MC3T3-E1 preosteoblast cells was examined using reverse transcription-quantitative PCR and western blotting. The Cell Counting Kit-8 (CCK-8) method and lactate dehydrogenase release assay were used to respectively measure cell viability and injury. Flow cytometry analysis was used to assay cell apoptosis. Caspase 3 activity was evaluated using a specific assay, while alkaline phosphatase and Alizarin red S staining were used to evaluate osteogenesis. 2,7-dichloro-dihydrofluorescein diacetate fluorescence probe was used to estimate reactive oxygen species generation. Specific assay kits were used to appraise oxidative stress levels. In addition, the expression of apoptosis-, osteogenic differentiation- and Kelch-like ECH-associated protein 1 (Keap1)/nuclear factor erythroid 2-related factor 2 (Nrf2) signaling-associated proteins was assessed using western blotting. In Nrf2 inhibitor (ML385)-pretreated MC3T3-E1 cells exposed to Dex, cell apoptosis, osteogenesis and oxidative stress were detected again as aforementioned. Results revealed that TRIM21 expression was raised in Dex-induced MC3T3-E1 cells and TRIM21 deletion improved the viability and osteogenic differentiation, whereas it hampered the oxidative stress and apoptosis in MC3T3-E1 cells with Dex induction. In addition, silencing of TRIM21 activated Keap1/Nrf2 signaling. Moreover, ML385 partially abrogated the effects of TRIM21 depletion on the oxidative stress, apoptosis and osteogenic differentiation in MC3T3-E1 cells exposed to Dex. In conclusion, TRIM21 silencing might activate Keap1/Nrf2 signaling to protect against steroid-induced ONFH.

Exosomes derived from M2 macrophages prevent steroid-induced osteonecrosis of the femoral head by modulating inflammation, promoting bone formation and inhibiting bone resorption.

Inflammatory reactions are involved in the development of steroid-induced osteonecrosis of the femoral head(ONFH). Studies have explored the therapeutic efficacy of inhibiting inflammatory reactions in steroid-induced ONFH and revealed that inhibiting inflammation may be a new strategy for preventing the development of steroid-induced ONFH. Exosomes derived from M2 macrophages(M2-Exos) display anti-inflammatory properties. This study aimed to examine the preventive effect of M2-Exos on early-stage steroid-induced ONFH and explore the underlying mechanisms involved. In vitro, we explored the effect of M2-Exos on the proliferation and osteogenic differentiation of bone marrow-derived mesenchymal stem cells(BMMSCs). In vivo, we investigated the role of M2-Exos on inflammation, osteoclastogenesis, osteogenesis and angiogenesis in an early-stage rat model of steroid-induced ONFH. We found that M2-Exos promoted the proliferation and osteogenic differentiation of BMMSCs. Additionally, M2-Exos effectively attenuated the osteonecrotic changes, inhibited the expression of proinflammatory mediators, promoted osteogenesis and angiogenesis, reduced osteoclastogenesis, and regulated the polarization of M1/M2 macrophages in steroid-induced ONFH. Taken together, our data suggest that M2-Exos are effective at preventing steroid-induced ONFH. These findings may be helpful for providing a potential strategy to prevent the development of steroid-induced ONFH.

Mechanism of KDM5A-mediated H3K4me3 modification in the osteogenic differentiation of mesenchymal stem cells in steroid-induced osteonecrosis of the femoral head.

OBJECTIVES: Steroid-induced osteonecrosis of the femoral head (SONFH) is characterized by impaired osteogenesis in bone marrow mesenchymal stem cells (BMSCs). This study investigates the role of lysine-specific demethylase 5A (KDM5A) in SONFH to identify potential therapeutic targets. METHODS: Human BMSCs were isolated and characterized for cell surface markers and differentiation capacity. A SONFH cell model was established using dexamethasone treatment. BMSCs were transfected with KDM5A overexpression vectors or si-KDM5A, and the expression of KDM5A, miR-107, runt-related transcription factor 2 (RUNX2), osteocalcin (OCN), and osteopontin (OPN) was assessed. Alizarin red staining was used to observe mineralization nodules, while alkaline phosphatase activity and cell viability were measured. The enrichment of KDM5A and histone 3 lysine 4 trimethylation (H3K4me3) on the promoters of RUNX2, OCN, and OPN was analyzed. The binding between miR-107 and KDM5A 3'UTR was validated, and the combined effect of miR-107 overexpression and KDM5A overexpression on BMSC osteogenic differentiation was evaluated. RESULTS: KDM5A was upregulated in BMSCs from SONFH. Inhibition of KDM5A promoted osteogenic differentiation of BMSCs, associated with increased RUNX2, OCN, and OPN promoters. KDM5A bound to the promoters of RUNX2, OCN, and OPN, leading to reduced H3K4me3 levels and downregulation of their expression. Overexpression of miR-107 inhibited KDM5A and enhanced BMSC osteogenic differentiation. CONCLUSION: KDM5A negatively regulates BMSC osteogenic differentiation by modulating H3K4me3 levels on the promoters of key osteogenic genes. miR-107 overexpression counteracts the inhibitory effect of KDM5A on osteogenic differentiation. These findings highlight the potential of targeting the KDM5A/miR-107 axis for SONFH therapy.

HIF-1α in cartilage homeostasis, apoptosis, and glycolysis in mice with steroid-induced osteonecrosis of the femoral head.

With the prevalence of coronavirus disease 2019, the administration of glucocorticoids (GCs) has become more widespread. Treatment with high-dose GCs leads to a variety of problems, of which steroid-induced osteonecrosis of the femoral head (SONFH) is the most concerning. Since hypoxia-inducible factor 1α (HIF-1α) is a key factor in cartilage development and homeostasis, it may play an important role in the development of SONFH. In this study, SONFH models were established using methylprednisolone (MPS) in mouse and its proliferating chondrocytes to investigate the role of HIF-1α in cartilage differentiation, extracellular matrix (ECM) homeostasis, apoptosis and glycolysis in SONFH mice. The results showed that MPS successfully induced SONFH in vivo and vitro, and MPS-treated cartilage and chondrocytes demonstrated disturbed ECM homeostasis, significantly increased chondrocyte apoptosis rate and glycolysis level. However, compared with normal mice, not only the expression of genes related to collagens and glycolysis, but also chondrocyte apoptosis did not demonstrate significant differences in mice co-treated with MPS and HIF-1α inhibitor. And the effects observed in HIF-1α activator-treated chondrocytes were similar to those induced by MPS. And HIF-1α degraded collagens in cartilage by upregulating its downstream target genes matrix metalloproteinases. The results of activator/inhibitor of endoplasmic reticulum stress (ERS) pathway revealed that the high apoptosis rate induced by MPS was related to the ERS pathway, which was also affected by HIF-1α. Furthermore, HIF-1α affected glucose metabolism in cartilage by increasing the expression of glycolysis-related genes. In conclusion, HIF-1α plays a vital role in the pathogenesis of SONFH by regulating ECM homeostasis, chondrocyte apoptosis, and glycolysis.

Gene expression profiling of peripheral blood in patients with steroid-induced osteonecrosis of the femoral head.

Aim: Steroid-induced osteonecrosis of the femoral head (SONFH) is a severe complication following glucocorticoid therapy. This study aimed to identify the differential mRNA expression and investigate the molecular mechanisms of SONFH. Materials & methods: RNA sequencing was performed in eight SONFH patients, five non-SONFH patients and five healthy individuals. Results: A total of 1555, 3997 and 5276 differentially expressed mRNAs existed between the following combinations: SONFH versus non-SONFH, SONFH versus healthy subjects and non-SONFH versus healthy subjects. Increased ISM1 expression might contribute to a high risk of SONFH through antiangiogenesis. Decreased FOLR3 expression might affect the metabolism of homocysteine, leading to avascular necrosis of the femoral head. KCNJ2, which plays a pivotal role in regulating bone development, was also deregulated. Conclusion: ISM1, FOLR3 and KCNJ2 might be related to the occurrence of SONFH.

[Box: see text].

Selenium nanoparticles/carboxymethyl chitosan/alginate antioxidant hydrogel for treating steroid-induced osteonecrosis of the femoral head.

Oxidative stress plays a crucial role in steroid-induced osteonecrosis of the femoral head (SONFH). Although several antioxidant strategies have been investigated for treating SONFH, their antioxidant efficiencies and therapeutic effects remain unsatisfactory. Here, we developed a selenium nanoparticles/carboxymethyl chitosan/alginate (SeNPs/CMC/Alg) antioxidant hydrogel and evaluated its ability to treat SONFH. In vitro assays indicated that the SeNPs/CMC/Alg hydrogel exhibited excellent properties, such as low cytotoxicity, sustained SeNPs release, and favorable antioxidant activity. Under oxidative stress, the SeNPs/CMC/Alg hydrogel promoted reactive oxygen species (ROS) elimination and enhanced the osteogenic and proangiogenic abilities of bone marrow mesenchymal stem cells (BMSCs). After establishing a rabbit model of SONFH, the SeNPs/CMC/Alg hydrogel was transplanted into the femoral head after core decompression (CD) surgery. Radiographic and histological analyses revealed that the hydrogel treatment alleviated SONFH by eliminating ROS and promoting osteogenesis and angiogenesis compared to those in the CD and CMC/Alg groups. In vitro and in vivo studies indicated that the Wnt/ß-catenin signaling pathway was activated by the SeNPs/CMC/Alg hydrogel in both hydrogen peroxide-conditioned BMSCs and necrotic femoral heads. These findings indicate that local transplantation of the SeNPs/CMC/Alg hydrogel is beneficial for treating SONFH, as it promotes ROS elimination and activation of the Wnt/ß-catenin signaling pathway.

Mechanism of compound Shengmai Chenggu capsule in the repair of steroid-induced osteonecrosis of the femoral head / 中国组织工程研究

BACKGROUND:Compound Shengmai Chenggu capsule has good therapeutic effects on early steroid-induced osteonecrosis of the femoral head,but the exact mechanism of treatment is not fully understood. OBJECTIVE:To observe the effect of compound Shengmai Chenggu capsule on fucosyltransferase 8,osteogenic gene and Wnt/β-catenin in bone tissue of rats with steroid-induced osteonecrosis of the femoral head. METHODS:Sixty Sprague-Dawley rats were randomized into blank group,model group,low-,middle-,and high-dose drug groups(n=12 per group).In the latter four groups,animal models of steroid-induced osteonecrosis of the femoral head were established by subcutaneous injection of imiquimod(once every 2 weeks,2 times in total)and gluteal muscle injection of methylprednisolone(once a week,4 times in total).The low-,middle-and high-dose drug groups were given 1.89,3.78 and 7.56 g/kg per day compound Shengmai Chenggu capsule solution by gavage respectively on the second day after the last modeling.The same amount of saline was given by gavage to the model group.Administration lasted 8 weeks.After the administration,micro-CT scan,histological staining,compression test,RT-qPCR and western blot were performed on the femoral head. RESULTS AND CONCLUSION:Micro-CT scan results showed that compared with the blank group,trabecular volume fraction,trabecular number and trabecular thickness were significantly decreased(P<0.05),while trabecular separation was increased in the model group(P<0.05).Compared with the model group,the compound Shengmai Chenggu capsule could increase trabecular volume fraction,trabecular number and trabecular thickness(P<0.05),and decrease trabecular separation(P<0.05)in a dose-dependent manner.Hematoxylin-eosin staining results showed that compared with the model group,the rate of empty bone lacunae was reduced in a dose-dependent group in the low-,middle-,and high-dose compound Shengmai Chenggu capsule groups(P<0.05).Immunohistochemical staining results showed that compared with the blank group,the protein expression of fucosyltransferase 8,Runx2 and bone morphogenetic protein 2 was reduced in the model group(P<0.05);compared with the model group,the compound Shengmai Chenggu capsule increased the protein expression of fucosyltransferase 8,Runx2 and bone morphogenetic protein 2 in a dose-dependent manner(P<0.05).Results from the compression test showed that there was a dose-dependent increase in the maximum load and elastic modulus of the femoral head in the low-,middle-,and high-dose compound Shengmai Chenggu capsule groups compared with the model group(P<0.05).RT-qPCR and western blot results showed that the mRNA and protein expressions of fucosyltransferase 8,Runx2,alkaline phosphatase,osteocalcin,osteoblast-specific transcription factor and bone morphogenetic protein 2 were decreased in the model group compared with the blank group(P<0.05);compared with the model group,there was a dose-dependent increase in the mRNA and protein expressions of the above indicators in the low-,middle-,and high-dose compound Shengmai Chenggu capsule groups compared with the model group(P<0.05).Compared with the blank group,the mRNA and protein expression of Wnt2,low-density lipoprotein receptor-related protein 5 and β-catenin were decreased(P<0.05)and the mRNA and protein expressions of glycogen synthase kinase 3β were increased(P<0.05)in the model group;compared with the model group,there was a dose-dependent increase in the mRNA and protein expressions of Wnt2,low-density lipoprotein receptor-related protein 5 and β-catenin(P<0.05)but a dose-dependent decrease in the mRNA and protein expressions of lycogen synthase kinase 3β(P<0.05)in the low-,middle-,and high-dose compound Shengmai Chenggu capsule groups.To conclude,the mechanism by which the compound Shengmai Chenggu capsule treats steroid-induced osteonecrosis of the femoral head may activate the Wnt/β-catenin signaling pathway through the up-regulation of fucosyltransferase 8,thereby promoting bone formation.

Exploration and clinical validation of the repair mode of the sclerotic zone of steroid-induced osteonecrosis of the femoral head based on Tandem Mass Tags technology / 中国组织工程研究

BACKGROUND:The sclerotic zone in the femoral head is an important imaging feature in the progression of steroid-induced femoral head necrosis,which is associated with disease prognosis.Peroxisome proliferator-activated receptor γ coactivator 1α(PGC-1α)has been shown to possess biological activities such as osteogenesis,angiogenesis and anti-mitochondrial apoptosis,which may be closely related to bone repair of steroid-induced femoral head necrosis. OBJECTIVE:To screen for the differential proteins in the sclerotic zone of steroid-induced osteonecrosis of the femoral head versus the normal zone,to screen for hub proteins in the sclerotic zone,and to verify the differential expression of hub proteins in the femoral head specimens following steroid-induced femoral head necrosis,and to to explore the repair pattern of the sclerotic zone following steroid-induced femoral head necrosis. METHODS:Femoral head samples were collected from patients with steroid-induced osteonecrosis of the femoral head receiving total hip arthroplasty.The differentially expressed genes in the sclerotic zone and the normal zone were screened by Tandem Mass Tags and analyzed by GO and KEGG signaling pathways to construct a protein-protein interaction network and screen hub genes.In addition,the expression of hub genes in the sclerotic zone was verified by immunohistochemistry and western blot. RESULTS AND CONCLUSION:Quantitative protein profiling by Tandem Mass Tags revealed that 609 proteins were significantly differentially expressed(Log2FC＞1.20,Log2FC＜0.84 and P＜0.05)in the sclerotic zone of the femoral head compared with the normal zone,of which 290 proteins were upregulated and 319 proteins were downregulated.The GO and KEGG pathway enrichment analyses revealed that among the top 10 enriched pathways,Wnt signaling pathway and life-cycle regulatory pathway were closely related to bone repair;in the life-cycle regulatory pathway,PGC-1α was one of the important proteins.In addition,western blot results verified the low expression of PGC-1α and NRF1 in the sclerotic zone and high expression of Cleaved Caspase-3 in the sclerotic zone compared with the normal zone of steroid-induced femoral head necrosis specimens.Light microscopic immunohistochemical results showed the distribution of PGC-1α,NRF1 and Cleaved Caspase-3 positive expression in the sclerotic and normal zones in the femoral head tissue specimens,indicating the presence of their expression in bone trabeculae,osteoblasts and bone marrow.In contrast,the brown area of the sclerotic zone of femoral head necrosis stained darker and showed more obvious expression of Cleaved Caspase-3.To conclude,in the sclerotic zone of steroid-induced femoral head necrosis,biological behaviors including activation of osteogenesis-related pathways such as Wnt and oxidative apoptosis characterized by low expression of PGC-1 are observed.Low expression of PGC-1α in the sclerotic zone of steroid-induced femoral head necrosis may be associated with the activation of oxidative apoptosis.

The pathological progression of steroid-induced osteonecrosis of the femoral head caused by oxidative stress-induced osteoblast ferroptosis / 中国组织工程研究

BACKGROUND:Studies have shown that imbalance of bone metabolism during glucocorticoid-induced osteonecrosis of the femoral head necrosis is closely related to oxidative stress. OBJECTIVE:To investigate the pathological mechanism by which oxidative stress-induced ferroptosis promote apoptosis in osteoblasts involved in steroid-induced osteonecrosis of the femoral head. METHODS:General data and serum specimens were collected from 47 patients with steroid-induced osteonecrosis of the femoral head.In addition,six femoral head specimens were collected from these patients.According to the Association Research Circulation Osseous(ARCO)staging system,serum specimens were grouped into ARCO Ⅱ,Ⅲ,and IV,while femoral head specimens were classified into ARCO Ⅲ and IV.Serum levels of malondialdehyde and superoxide dismutase 1 were measured.The protein expression of superoxide dismutase 1,glutathione peroxidase 4,Bcl-2 in the femoral head was detected and verified by Data independent acquisition(DIA)for quantitative sequencing,western blot and alkaline phosphate detection. RESULTS AND CONCLUSION:The ARCO stage of patients with steroid-induced osteonecrosis of the femoral head was independent of age,sex and necrotic side.The serum levels of malondialdehyde and superoxide dismutase 1 were higher in patients with ARCO stage Ⅲ compared with those with ARCO stage Ⅱ and IV.The results of DIA protein quantification showed that the function of differential proteins was mainly related to redox.The levels of superoxide dismutase 1,glutathione peroxidase 4,and Bcl-2 in the necrotic region were lower than in the normal region,as well as lower in ARCO stage IV than in ARCO stage Ⅲ.Western blot verified the results of DIA protein quantification.The alkaline phosphatase activity was lower in the necrotic region than in the normal region,as well as lower in ARCO stage IV than in ARCO stage Ⅲ.In the necrotic and sclerotic regions,the function of differential proteins was also related to redox,and superoxide dismutase 1,glutathione peroxidase 4,Bcl-2 protein expression and alkaline phosphatase activity were lower in the necrotic area than in the sclerotic region,as well as lower in ARCO stage IV than in ARCO stage Ⅲ.To conclude,glucocorticoids can influence the progression of steroid-induced osteonecrosis of the femoral head by upregulating oxidative stress levels,inducing osteoblast ferroptosis,and inhibiting osteogenic function.

Mechanisms by which baicalein protects against steriod-induced osteonecrosis of the femoral head in rats / 中国组织工程研究

BACKGROUND:The development of steroid-induced osteonecrosis of the femoral head is a complex process involving multiple mechanisms.There is still no standard therapeutic drug for early intervention of this disease.Current studies have shown that baicalein has various pharmacological activities such as regulating lipid metabolism,bone metabolism,apoptosis and anti-oxidative stress,which provides an idea for the prevention and treatment of steroid-induced osteonecrosis of the femoral head. OBJECTIVE:To observe the preventive effect of baicalein against steroid-induced osteonecrosis of the femoral head and to investigate its possible mechanism. METHODS:Thirty-six 10-week-old male Sprague-Dawley rats were randomly divided into three groups(n=12 per group):blank control group,model group,and baicalein intervention group.In the model group and baicalein intervention group,intraperitoneal lipopolysaccharide and intramuscular injection of methylprednisolone sodium succinate were performed for modeling,while normal saline was used as a substitute for the modeling drug in the blank control group.Baicalein 300 mg/kg was administered by gavage(once a day for 6 weeks)at the time of initial intramuscular glucocorticoid injection in the baicalein intervention group,and baicalein was replaced by normal saline in the other two groups.The serum level of malondialdehyde in rats was detected at 2 weeks of the experiment.Blood lipid indicators and bone formation metabolic markers were detected at 6 weeks of the experiment,the histomorphometric changes of the femoral head were analyzed by hematoxylin-eosin staining,anti-tartaric acid phosphatase staining and TUNEL staining,and the femoral head was subjected to Micro-CT scanning and three-dimensional reconstruction of the bone in order to analyze the alterations of bone tissue structure and parameters. RESULTS AND CONCLUSION:The serum levels of malondialdehyde,triglyceride,β-collagen type Ⅰ carboxy-terminal peptide were increased and the serum levels of bone specific alkaline phosphatase and pre-collagen type Ⅰ amino-terminal peptide were decreased in the model group compared with the blank control group(P＜0.05).The serum level of malondialdehyde decreased in the baicalein intervention group compared with the model group(P＜0.05),but there was no significant difference between the baicalein intervention group and blank control group(P＞0.05).The serum level of triglyceride was higher in the baicalein intervention group than the blank control group(P＜0.05),but had no significant difference between the baicalein intervention group and model group(P＞0.05).There were also no significant differences in the levels of bone specific alkaline phosphatase and β-collagen type Ⅰ carboxy-terminal peptide between the baicalein intervention group and the other two groups(P＞0.05).The serum level of the baicalein intervention group was lower in the baicalein intervention group than the blank control group(P＜0.05)but had no significant difference between the baicalein intervention group and model group(P＞0.05).Histomorphological analysis of the femoral head showed that the rate of bone empty lacuna,osteoclast counting and cell apoptosis rate in the femoral head of model group rats were significantly higher than those of the other two groups(P＜0.05).There was a significant increase in the number of adipocytes in the bone marrow cavity of the femoral head,bone trabeculae were thinned and sparsely arranged with more disruptions in the continuity.The incidence of osteonecrosis was higher in the model group(75%)than in the baicalein intervention group(25%;bilateral and unilateral exact significance results were both 0.05).There was also an increase in the number of adipocytes in the bone marrow cavity of the femoral head in the baicalein intervention group,and the trabecular changes were roughly similar to those in the model group.Micro-CT results showed that bone volume fraction,trabecular thickness,trabecular number,and bone mineral density decreased and trabecular separation increased in the model group compared with the blank control group(P＜0.05).Overall significant bone mass loss was observed in the model group.Bone tissue parameters in the baicalein intervention group were significantly improved than those in the model group,which were reflected in bone volume fraction,trabecular thickness and trabecular separation(P＜0.05),and trabecular number and bone mineral density had no significant difference between the baicalein intervention group and blank control group(P＞0.05).Although baicalein failed to significantly ameliorate dyslipidemia and promote bone formation in rats with steroid-induced osteonecrosis of the femoral head,it could reduce the incidence of steroid-induced osteonecrosis of the femoral head by reducing oxidative stress damage,decreasing cell apoptosis,inhibiting osteoclasts,suggesting its effectiveness in the early prevention of steroid-induced osteonecrosis of the femoral head.

Active ingredients of Panax notoginseng regulate signaling pathways related to steroid-induced necrosis of the femoral head / 中国组织工程研究

BACKGROUND:Steroid-induced osteonecrosis of the femoral head is a refractory disease in the field of orthopedics.There is no definitive idea to fully explain its pathogenesis.With the increased research on the active ingredients of Panax notoginseng interfering with the signaling pathways related to various diseases,the active ingredients of Panax notoginseng that treat steroid-induced necrosis of the femoral head via the regulation of relevant signaling pathways have gradually become a hot research topic. OBJECTIVE:To systematically summarize the literature on the pathological mechanism of steroid-induced osteonecrosis of the femoral head and the regulation of signaling pathways by the active ingredients of Panax notoginseng in recent years,thereby providing a reference for the follow-up study on the active ingredients of Panax notoginseng in the treatment of this disease. METHODS:CNKI,WanFang,and PubMed were searched for relevant literature with the key words of"glucocorticoid,steroid-induced osteonecrosis of the femoral head,pathological mechanism,signaling pathway,Panax notoginseng,active ingredient"in Chinese and English.Documents related to the pathological mechanism of steroid-induced osteonecrosis of the femoral head as well as related to the intervention of active ingredients of Panax notoginseng on the signaling pathway of steroid-induced osteonecrosis of the femoral head were retrieved.A total of 63 documents were finally included according to the inclusion and exclusion criteria. RESULTS AND CONCLUSION:The main ingredients of Panax notoginseng include Panax notoginseng saponins,ginsenoside,Panax notoginseng saponins,quercetin,kaempferol,etc.Panax notoginseng saponins,ginsenoside Rb1 and quercetin can promote bone repair and angiogenesis by acting on the transforming growth factor-β/bone morphogenetic protein pathway.Panax notoginseng saponins,ginsenoside CK and kaempferol can promote osteogenic differentiation and lipid metabolism by acting on the Wnt/β-catenin pathway.Panax notoginseng saponins and Panax notoginseng saponins R1/R2 act on the MAPK pathway to inhibit osteoclastogenesis and promote bone repair.Panax notoginseng saponins,ginsenoside Rb2 and quercetin can inhibit osteoclast proliferation and promote osteoblastic differentiation by acting on the RANKL/RANK/OPG pathway.Panax notoginseng saponins,quercetin and kaempferol can repair vascular injury and promote osteogenesis by acting on the hypoxia-inducible factor-1α pathway.Panax notoginseng saponins R1,quercetin combined with hydroxyapatite nanoparticles,Panax notoginseng saponins combined with polyethylene-L-lactic acid and other biomaterials have good research prospects in the treatment of steroid-induced osteonecrosis of the femoral head.The active ingredients of Panax notoginseng can regulate the signaling pathways related to steroid-induced osteonecrosis of the femoral head through various mechanisms,and play an active intervention role in the disease.However,the depth and breadth of relevant research are insufficient at present,and the future research should be based on the existing mechanism to explore the specific mechanism of Panax notoginseng regulating different pathways and the interaction between pathways,which will be beneficial to the multi-development of the active ingredients of Panax notoginseng in the treatment of steroid-induced osteonecrosis of the femoral head.

Bioinformatics identification of CA9 as a signature gene for cartilage-associated ferroptosis in steroid-induced osteonecrosis of the femoral head / 中国组织工程研究

BACKGROUND:Disturbances in bone metabolism have a significant association with ferroptosis in steroid-induced osteonecrosis of the femoral head(SONFH).Furthermore,the pathologic process of SONFH is characterized by the presence of cartilage damage and degeneration.However,the specific regulatory targets and the relationship between ferroptosis and cartilage concerning SONFH remain unclear. OBJECTIVE:To employ bioinformatics and machine learning techniques to identify specific genes associated with ferroptosis that target cartilage and to investigate the correlation between ferroptosis and cartilage,thereby providing novel ideas and methodologies for the study and treatment of SONFH. METHODS:Disease datasets pertinent to the study and ferroptosis-related genes were retrieved from the GEO and FerrDb databases.Subsequently,the disease datasets were normalized and differential analysis using the R language to identify ferroptosis-related differential genes(Fe-DEGs).We conducted Gene Ontology(GO)functional enrichment analysis and Kyoto Encyclopedia of Genes and Genomes(KEGG)signaling pathway enrichment analysis of Fe-DEGs.Furthermore,ferroptosis-related signature genes were filtered based on the protein-protein interaction network of Fe-DEGs and machine learning methods.Finally,the rabbits were divided into normal and model groups.The normal group was given the same dose of saline to simulate the modeling drug,and the animal model of SONFH in rabbits was constructed by injection of modified horse serum combined with methylprednisolone.After successful modeling,the expression of signature gene was verified between different groups,and the phenotype of ferroptosis in cartilage was analyzed. RESULTS AND CONCLUSION:Through the normalization and differential analysis of the dataset,a total of 1 315 differentially expressed genes were identified.Additionally,379 ferroptosis-related genes were obtained from the FerrDb database.After intersecting both gene sets,19 Fe-DEGs were obtained.The GO analysis revealed that Fe-DEGs were mainly involved in biological processes such as cell migration and cellular response to oxidative stress,cellular components such as kinase complexes,amino acid complexes,and cytoplasmic membranes,as well as molecular functions such as kinase activity,receptor activity,and protein binding.The KEGG analysis revealed that Fe-DEGs were mainly enriched in the FoxO signaling pathway,vascular endothelial growth factor signaling pathway,and FcγR-mediated phagocytosis.Constructing a protein-protein interaction network and using machine learning,we identified the ferroptosis-related signature gene,CA9.The gene set enrichment analysis of the signature gene CA9 revealed an upregulated expression in biological processes such as fatty acid metabolism and O-GlcNAc glycosylation modification,while being inhibited in terms of neural activity and ligand-receptor interactions.RT-PCR and western blot results showed that compared with the normal group,the expressions of ACSL4 and CA9 at mRNA and protein levels were significantly higher in the model group(P<0.05),while the expressions of SLC7A11 and GPX4 at mRNA and protein levels were significantly lower in the model group(P<0.05),coinciding with the expression levels of the signature genes in the dataset.These findings indicate that the cartilage of SONFH is closely related to ferroptosis,and targeting the signature gene may provide certain ideas and directions for the study and treatment of SONFH.

Mechanisms underlying internal heat-type acupuncture in the treatment of steroid-induced osteonecrosis of the femoral head in rabbits / 中国组织工程研究

BACKGROUND:Internal heat-type acupuncture therapy is a new treatment technique that combines acupuncture therapy with hyperthermia.It has good clinical effects on steroid-induced osteonecrosis of the femoral head,but the mechanism of action is still not fully clear. OBJECTIVE:To explore the possible mechanism of internal heat-type acupuncture therapy in treating steroid-induced osteonecrosis of the femoral head in rabbits. METHODS:Thirty-two New Zealand rabbits were randomly divided into blank group,model group,internal heat-type acupuncture group and shock wave group using a random number table method,with 8 rabbits in each group.The model group,internal heat-type acupuncture group and shock wave group were modeled using methylprednisolone sodium succinate combined with Escherichia coli endotoxin.The internal heat-type acupuncture group received an internal heat-type acupuncture intervention on the buttocks of rabbits,once a week,for 20 minutes each time.The shock wave group received shock wave intervention on the buttocks of rabbits,once a week,with 2 000 beats per session.The blank group and model group were not given any treatment.After 4 weeks of intervention,blood samples and bilateral femoral head samples were collected from experimental rabbits.The levels of tumor necrosis factor-α and interleukin-6 in serum were detected by ELISA;the histomorphology of the femoral head was observed using hematoxylin-eosin staining and the rate of empty lacunae was calculated;the protein expressions of matrix metalloproteinase 2,matrix metalloproteinase 9,matrix metalloproteinase tissue inhibitor 1,and matrix metalloproteinase tissue inhibitor 2 were detected by immunohistochemistry and western blot. RESULTS AND CONCLUSION:Compared with the blank group,the model rabbits showed reduced food intake,mental fatigue,and decreased activity;compared with the model group,the above performance of the experimental rabbits was significantly improved after internal heat-type acupuncture and shock wave treatment.Compared with the blank group,the histomorphology of the femoral head in the model group deteriorated significantly and the rate of empty bone lacuna increased(P<0.001),while the histomorphology of the femoral head in the internal heat-type acupuncture group and shock wave group was significantly improved compared with the model group,and the rate of empty bone lacuna was reduced(P<0.001).The serum levels of tumor necrosis factor-α and interleukin-6 in the model group were significantly higher than those in the blank group(P<0.05),while the serum levels of tumor necrosis factor-α and interleukin-6 in the internal heat-type acupuncture group and the shock wave group were significantly lower than those in the model group(P<0.05).Compared with the blank group,the expression levels of matrix metalloproteinase 2 and matrix metalloproteinase 9 in the femoral head of the model group were significantly increased,while the expression levels of matrix metalloproteinase tissue inhibitor 1 and matrix metalloproteinase tissue inhibitor 2 were significantly decreased(P<0.001);compared with the model group,the protein expression levels of matrix metalloproteinase 2 and matrix metalloproteinase 9 were significantly decreased,while the protein expression levels of matrix metalloproteinase tissue inhibitor 1 and matrix metalloproteinase tissue inhibitor 2 were significantly increased in the internal heat-type acupuncture group and the shock wave group(P<0.001).Overall,these findings indicate that internal heat-type acupuncture may promote the repair of the necrotic femoral head by regulating the levels of matrix metalloproteinases/matrix metalloproteinase tissue inhibitors and serum inflammatory factors,thus treating early steroid-induced osteonecrosis of the femoral head.

Oleanolic acid alleviates steroid-induced osteonecrosis of the femoral head in rats by regulating Wnt/beta-catenin signaling pathway / 中国组织工程研究

BACKGROUND:Oleanolic acid can promote osteoblast proliferation and inhibit osteoclast proliferation,thereby improving steroid-induced osteonecrosis of the femoral head,but its specific mechanism of action is not yet fully understood. OBJECTIVE:To explore the mechanism by which oleanolic acid alleviates steroid-induced osteonecrosis of the femoral head in rats by regulating the Wnt/β-catenin signaling pathway. METHODS:Forty Sprague-Dawley rats were randomized into control group,model group,oleanolic acid group and oleanolic acid+sFRP1 group.An animal model of steroid-induced osteonecrosis of the femoral head was established by injecting prednisolone acetate in the latter three groups.Rats in the oleanolic acid group were gavaged with 10 mg/kg/d oleanolic acid and intramuscularly injected with the corresponding saline;rats in the oleanolic acid+sFRP1 group were gavaged with 10 mg/kg/d oleanolic acid and intramuscularly injected with 1 mg/kg/d Wnt inhibitor-sFRP1;and rats in the control and model groups were administered by gavage and intramuscularly injected with equal volumes of saline for 6 weeks.The levels of serum calcium,phosphorus,transforming growth factor-β1,and alkaline phosphatase were detected.Micro-CT was applied to detect femoral morphology.The morphology of femoral tissue was detected by hematoxylin-eosin staining.Cell apoptosis was detected by TUNEL.The levels of Bcl-2,Bax,β-catenin,and Wnt proteins were determined by western blot. RESULTS AND CONCLUSION:Compared with the control group,the trabeculae bone and femoral head of the model group were seriously injured,the serum levels of calcium,phosphorus,and transforming growth factor-β1 were significantly decreased,the levels of Bcl-2,Wnt,and β-catenin proteins in bone tissue were significantly reduced,and the serum alkaline phosphatase level,cell apoptosis rate,and Bax protein level were significantly increased(P<0.05).Compared with the model group,the degree of trabecular thinning in the oleanolic acid group was significantly improved,and the degree of femoral head damage was significantly reduced,serum alkaline phosphatase level,cell apoptosis rate,and Bax protein level were significantly reduced,serum levels of calcium,phosphorus,and transforming growth factor-β1,and levels of Bcl-2,Wnt,and β-catenin proteins in bone tissue were significantly increased(P<0.05).Compared with the oleanolic acid group,the oleanolic acid+sFRP1 group showed opposite changes in the above-mentioned indicators(P<0.05).To conclude,oleanolic acid can improve bone metabolism indicators and trabecular structure and attenuate femoral head necrosis in rats with steroid-induced osteonecrosis of the femoral head,which can be achieved by activating the Wnt/β-catenin signaling pathway.

Bioinformatics analysis of m6A-associated genes in steroid-induced osteonecrosis of the femoral head / 中国组织工程研究

BACKGROUND:m6A modification has been confirmed to play an important role in the occurrence and development of osteonecrosis of the femoral head;however,the role of m6A modification patterns in steroid-induced osteonecrosis of the femoral head remains unknown. OBJECTIVE:Bioinformatics analysis was performed based on the Gene Expression Omnibus(GEO)database to analyze the differential expression of the m6A gene in steroid-induced osteonecrosis of the femoral head,predict the downstream targeted miRNAs,and investigate the potential pathogenesis. METHODS:Expressing profiles of mRNA data of steroid-induced osteonecrosis of the femoral head were downloaded from GEO database(GSE123568).Differentially expressed genes(DEGs),Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway enrichment analysis were performed using the R software.After obtaining these differentially methylated m6A genes(m6A-DEGs),we analyzed GO function and KEGG pathway enrichment and compared the correlation among the m6A-DEGs typing according to gene expression.The protein-protein interaction network and core gene subnetwork of m6A-DEGs were constructed using Cytoscape software.The m6A-DEGs-associated potential miRNAs were predicted using the TargetScan,miRTarBase,and miRBD databases.Simultaneously,ChIPBase and hTFtarget databases were used to predict potential transcription factors of seven core genes,then m6A-miRNA and transcription factor-m6A regulatory networks were constructed separately.Finally,the expression levels of the seven core m6A-DEGs were verified by using the GSE74089 dataset. RESULTS AND CONCLUSION:(1)A total of 2 460 common DEGs were screened out from datasets,among which 1 455 genes were upregulated and 1 005 genes were downregulated.(2)A total of 14 m6A-DEGs were identified in the datasets.Among them,11 m6A-DEGs were up-regulated and 3 m6A-DEGs were down-regulated.Differential gene expression was considered significant for m6A-DEGs in steroid-induced osteonecrosis of the femoral head(P<0.05).Spearman correlation analysis showed a significant correlation between m6A-DEGs.(3)GO and KEGG enrichment analysis showed that m6A-DEGs were mainly enriched in myeloid cell differentiation and development,immune and cytokine receptor activity,osteoclast differentiation,AMPK signaling pathway and interleukin-17 signaling pathway.(4)The seven core genes of m6A-DEGs contained YTHDF3,YTHDF1,YTHDF2,ALKBH5,METTL3,HNRNPA2B1,and HNRNPC.A total of 44 miRNAs overlapping were detected in the miRTarBase,miRDB,and TargetScan databases.Totally 79 transcription factors overlapping were found in the ChIPBase and hTFtarget databases.(5)The expression levels of six core m6A-DEGs in the GSE74089 dataset were consistent with those in the GSE123568 dataset.(6)These findings confirm that the seven m6A-DEGs identified through bioinformatics techniques play a regulatory role in the expression of various miRNAs,transcription factors,AMPK,and interleukin-17 signaling pathways,and these genes have a significant impact on the differentiation and development of bone marrow cells as well as osteoclast differentiation in steroid-induced osteonecrosis of the femoral head.Consequently,these findings offer data support and establish a research direction for future investigations into the pathogenesis and targeted therapeutic strategies for steroid-induced osteonecrosis of the femoral head.

Glucocorticoids promote steroid-induced osteonecrosis of the femoral head by down-regulating serum alpha-2-macroglobulin to induce oxidative stress and facilitate SIRT2-mediated BMP2 deacetylation.

Our study investigated the possible molecular mechanism of glucocorticoid in steroid-induced osteonecrosis of the femoral head (SINFH) through regulating serum alpha-2-macroglobulin and SIRT2-mediated BMP2 deacetylation. Essential genes involved in glucocorticoid-induced SINFH were screened by transcriptome sequencing and analyzed by bioinformatics, followed by identifying downstream regulatory targets. Rat bone marrow mesenchymal stem cells were isolated and treated with methylprednisolone (MP) for in vitro cell experiments. Besides, a glucocorticoid-induced rat ONFH was established using the treatment of MP and LPS. ChIP-PCR detected the enrichment of SIRT2 in the promoter region of BMP2, and the deacetylation modification of SIRT2 on BMP2 was determined. Bioinformatics analysis revealed that glucocorticoids may induce ONFH through the SIRT2/BMP2 axis. In vitro cell experiments showed that glucocorticoids up-regulated SIRT2 expression in BMSCs by inducing oxidative stress, thereby promoting cell apoptosis. The up-regulation of SIRT2 expression may be due to the decreased ability of α2 macroglobulin to inhibit oxidative stress, and the addition of NOX protein inhibitor DPI could significantly inhibit SIRT2 expression. SIRT2 could promote histone deacetylation of the BMP2 promoter and inhibit its expression. In vitro cell experiments further indicated that knocking down SIRT2 could protect BMSC from oxidative stress and cell apoptosis induced by glucocorticoids by promoting BMP2 expression. In addition, animal experiments conducted also demonstrated that the knockdown of SIRT2 could improve glucocorticoid-induced ONFH through up-regulating BMP2 expression. Glucocorticoids could induce oxidative stress by down-regulating serum α2M to promote SIRT2-mediated BMP2 deacetylation, leading to ONFH.

[Characteristic changes of blood stasis syndrome in rat model of steroid-induced femoral head necrosis based on the combination of disease, syndrome, and symptom].

The approach combining disease, syndrome, and symptom was employed to investigate the characteristic changes of blood stasis syndrome in a rat model of steroid-induced osteonecrosis of the femoral head(SONFH) during disease onset and progression. Seventy-two male SD rats were randomized into a healthy control group and a model group. The rat model of SONFH was established by injection of lipopolysaccharide(LPS) in the tail vein at a dose of 20 µg·kg~(-1)·d~(-1) on days 1 and 2 and gluteal intramuscular injection of methylprednisolone sodium succinate(MPS) at a dose of 40 mg·kg~(-1)·d~(-1) on days 3-5, while the healthy control group received an equal volume of saline. The mechanical pain test, tongue color RGB technique, gait detection, open field test, and inclined plane test were employed to assess hip pain, tongue color, limping, joint activity, and lower limb strength, respectively, at different time points within 21 weeks of modeling. At weeks 2, 4, 8, 12, 16, and 21 after modeling, histopathological changes of the femoral head were observed by hematoxylin-eosin(HE) staining and micro-CT scanning; four coagulation items were measured by rotational thromboelastometry; and enzyme-linked immunosorbent assay(ELISA) was employed to determine the levels of six blood lipids, vascular endothelial growth factor(VEGF), endothelin-1(ET-1), nitric oxide(NO), tissue-type plasminogen activator(t-PA), plasminogen activator inhibitor factor-1(PAI-1), bone gla protein(BGP), alkaline phosphatase(ALP), receptor activator of nuclear factor-κB(RANKL), osteoprotegerin(OPG), and tartrate-resistant acid phosphatase 5b(TRAP5b) in the serum, as well as the levels of 6-keto-prostaglandin 1α(6-keto-PGF1α) and thromboxane B2(TXB2) in the plasma. The results demonstrated that the pathological alterations in the SONFH rats were severer over time. The bone trabecular area ratio, adipocyte number, empty lacuna rate, bone mineral density(BMD), bone volume/tissue volume(BV/TV), trabecular thickness(Tb.Th), trabecular number(Tb.N), bone surface area/bone volume(BS/BV), and trabecular separation(Tb.Sp) all significantly increased or decreased over the modeling time after week 4. Compared with the healthy control group, the mechanical pain threshold, gait swing speed, stride, standing time, and walking cycle of SONFH rats changed significantly within 21 weeks after modeling, with the greatest difference observed 12 weeks after modeling. The time spent in the central zone, rearing score, and maximum tilt angle in the open field test of SONFH rats also changed significantly over the modeling time. Compared with the healthy control group, the R, G, and B values of the tongue color of the model rats decreased significantly, with the greatest difference observed 11 weeks after modeling. The levels of total cholesterol(TC), total triglycerides(TG), low-density lipoprotein-cholesterol(LDL-C), and apoprotein B(ApoB) in the SONFH rats changed significantly 4 and 8 weeks after modeling. The levels of VEGF, ET-1, NO, t-PA, PAI-1, 6-keto-PGF1α, TXB2, four coagulation items, and TXB2/6-keto-PGF1α ratio in the serum of SONFH rats changed significantly 4-16 weeks after modeling, with the greatest differences observed 12 weeks after modeling. The levels of BGP, TRAP5b, RANKL, OPG, and RANKL/OPG ratio in the serum of SONFH rats changed significantly 8-21 weeks after modeling. During the entire onset and progression of SONFH in rats, the blood stasis syndrome characteristics such as hyperalgesia, tongue color darkening, gait abnormalities, platelet, vascular, and coagulation dysfunctions were observed, which gradually worsened and then gradually alleviated in the disease course(2-21 weeks), with the most notable differences occurred around 12 weeks after modeling.

Effect of whole body vibration therapy in the rat model of steroid-induced osteonecrosis of the femoral head.

Background: Steroid-induced Osteonecrosis of the Femoral Head (SIONFH) is a skeletal disease with a high incidence and a poor prognosis. Whole body vibration therapy (WBVT), a new type of physical training, is known to promote bone formation. However, it remains unclear whether WBVT has a therapeutic effect on SIONFH. Materials and methods: Thirty adult male and female Sprague-Dawley (SD) rats were selected and randomly assigned to three experimental groups: the control group, the model group, and the mechanical vibration group, respectively. SIONFH induction was achieved through the combined administration of lipopolysaccharides (LPS) and methylprednisolone sodium succinate for injection (MPS). The femoral head samples underwent hematoxylin and eosin (H&E) staining to visualize tissue structures. Structural parameters of the region of interest (ROI) were compared using Micro-CT analysis. Immunohistochemistry was employed to assess the expression levels of Piezo1, BMP2, RUNX2, HIF-1, VEGF, CD31, while immunofluorescence was used to examine CD31 and Emcn expression levels. Results: The H&E staining results revealed a notable improvement in the ratio of empty lacuna in various groups following WBVT intervention. Immunohistochemical analysis showed that the expression levels of Piezo1, BMP2, RUNX2, HIF-1, VEGF, and CD31 in the WBVT group exhibited significant differences when compared to the Model group (p < 0.05). Additionally, immunofluorescence analysis demonstrated statistically significant differences in CD31 and Emcn expression levels between the WBVT group and the Model group (p < 0.05). Conclusion: WBVT upregulates Piezo1 to promote osteogenic differentiation, potentially by enhancing the HIF-1α/VEGF axis and regulating H-vessel angiogenesis through the activation of the Piezo1 ion channel. This mechanism may lead to improved blood flow supply and enhanced osteogenic differentiation within the femoral head.

Plasma 8-OHdG act as a biomarker for steroid-induced osteonecrosis of the femoral head.

BACKGROUND: Oxidative stress was closely related to the occurrence and development of Steroid-induced osteonecrosis of the femoral head (SIONFH). 8-hydroxy-2'-deoxyguanosine (8-OHdG) is a important index of oxidative stress. The aim of this study is to investigate the role of 8-OHdG in the development of SIONFH. METHODS: From May 2021 and November 2021, 33 patients diagnosed with SIONFH and 26 healthy controls were recruited in this study. Assessment included the radiography and pathology evaluation of clinical bone tissue, expression position and level of 8-OHdG, level of plasma 8-OHdG, as well as the receiver operating characteristic (ROC) curve. RESULTS: We observed that expression levels of 8-OHdG in bone samples decreased with Association Research Circulation Osseous (ARCO) stages. Plasma 8-OHdG levels were significantly increased in the SIONFH group compared to the healthy control group. Plasma 8-OHdG level of pre-collapse patients was higher than that of post-collapse patients, the decreased plasma 8-OHdG level was related to higher ARCO stages. CONCLUSION: Plasma 8-OHdG may represent potential biomarkers during SIONFH at different stages. Higher plasma 8-OHdG levels indicated early stage of SIONFH. The current study provided new clues for early diagnosis and treatment for SIONFH.