A Novel Locking Buttress Plate Designed for Simultaneous Medial and Posterolateral Tibial Plateau Fractures: Concept and Comparative Finite Element Analysis.

OBJECTIVE: The complex tibial plateau fractures involving both medial and posterolateral columns are of frequent occurrence in clinics, but the existing fixation system cannot deal with medial and posterolateral fragments simultaneously. Therefore, a novel locking buttress plate named as medial and posterior column plate (MPCP) was designed in this study to fix the simultaneous medial and posterolateral tibial plateau fractures. Meanwhile, the comparative finite element analysis (FEA) was conducted to investigate the discrepancy between MPCP and traditional multiple plates (MP + PLP) in their biomechanical characteristics. METHODS: Two 3D finite element models of simultaneous medial and posterolateral tibial plateau fracture fixed with MPCP and MP + PLP system, respectively, was constructed. To imitate the axial stress of knee joint in ordinary life, diverse axial forces with 100, 500, 1000, and 1500 N were applied in the two fixation models, and then the equivalent displacement and stress nephograms and values were obtained. RESULTS: The similar trend of displacement and stress increasing with the loads was observed in the two fixation models. However, several heterogeneities of displacement and stress distribution were found in the two fixation models. The max displacement and von Mises stress values of plates, screws, and fragments in the MPCP fixation model were significantly smaller than that in the MP + PLP fixation model, except for the max-shear stress values. CONCLUSION: As a single locking buttress plate, the MPCP system showed the excellent benefit on improving the stability of the simultaneous medial and posterolateral tibial plateau fractures, compared with the traditional double plate fixation system. However, the excessive shear stress around screw holes should be paid attention to prevent trabecular microfracture and screw loosening.

Baicalin attenuates dexamethasone-induced apoptosis of bone marrow mesenchymal stem cells by activating the hedgehog signaling pathway.

BACKGROUND: Perturbations in bone marrow mesenchymal stem cell (BMSC) differentiation play an important role in steroid-induced osteonecrosis of the femoral head (SONFH). At present, studies on SONFH concentrate upon the balance within BMSC osteogenic and adipogenic differentiation. However, BMSC apoptosis as well as proliferation are important prerequisites in their differentiation. The hedgehog (HH) signaling pathway regulates bone cell apoptosis. Baicalin (BA), a well-known compound in traditional Chinese medicine, can affect the proliferation and apoptosis of numerous cell types via HH signaling. However, the potential role and mechanisms of BA on BMSCs are unclear. Thus, we aimed to explore the role of BA in dexamethasone (Dex)-induced BMSC apoptosis in this study. METHODS: Primary BMSCs were treated with 10 -6 mol/L Dex alone or with 5.0 µmol/L, 10.0 µmol/L, or 50.0 µmol/L BA for 24 hours followed by co-treatment with 5.0 µmol/L, 10.0 µmol/L, or 50.0 µmol/L BA and 10 -6 mol/L Dex. Cell viability was assayed through the Cell Counting Kit-8 (CCK-8). Cell apoptosis was evaluated using Annexin V-fluorescein isothiocyanate/propidium iodide (PI) staining followed by flow cytometry. The imaging and counting, respectively, of Hochest 33342/PI-stained cells were used to assess the morphological characteristics and proportion of apoptotic cells. To quantify the apoptosis-related proteins (e.g., apoptosis regulator BAX [Bax], B-cell lymphoma 2 [Bcl-2], caspase-3, and cleaved caspase-3) and HH signaling pathway proteins, western blotting was used. A HH-signaling pathway inhibitor was used to demonstrate that BA exerts its anti-apoptotic effects via the HH signaling pathway. RESULTS: The results of CCK-8, Hoechst 33342/PI-staining, and flow cytometry showed that BA did not significantly promote cell proliferation (CCK-8: 0 µmol/L, 100%; 2.5 µmol/L, 98.58%; 5.0 µmol/L, 95.18%; 10.0 µmol/L, 98.11%; 50.0 µmol/L, 99.38%, F   =  2.33, P   >  0.05), but it did attenuate the effect of Dex on apoptosis (Hoechst 33342/PI-staining: Dex+ 50.0 µmol/L BA, 12.27% vs. Dex, 39.27%, t  = 20.62; flow cytometry: Dex + 50.0 µmol/L BA, 12.68% vs. Dex, 37.43%, t  = 11.56; Both P  < 0.05). The results of western blotting analysis showed that BA reversed Dex-induced apoptosis by activating the HH signaling pathway, which down-regulated the expression of Bax, cleaved-caspase 3, and suppressor of fused (SUFU) while up-regulating Bcl-2, sonic hedgehog (SHH), and zinc finger protein GLI-1 (GLI-1) expression (Bax/Bcl-2: Dex+ 50.0 µmol/L BA, 1.09 vs. Dex, 2.76, t  = 35.12; cleaved caspase-3/caspase-3: Dex + 50.0 µmol/L BA, 0.38 vs . Dex, 0.73, t  = 10.62; SHH: Dex + 50.0 µmol/L BA, 0.50 vs . Dex, 0.12, t  = 34.01; SUFU: Dex+ 50.0 µmol/L BA, 0.75 vs . Dex, 1.19, t  = 10.78; GLI-1: Dex+ 50.0 µmol/L BA, 0.40 vs . Dex, 0.11, t  = 30.68. All P  < 0.05). CONCLUSIONS: BA antagonizes Dex-induced apoptosis of human BMSCs by activating the HH signaling pathway. It is a potential candidate for preventing SONFH.

LINC00473-modified bone marrow mesenchymal stem cells incorporated thermosensitive PLGA hydrogel transplantation for steroid-induced osteonecrosis of femoral head: A detailed mechanistic study and validity evaluation.

The pathogenesis of steroid-induced osteonecrosis of the femoral head (SONFH) involves a glucocorticoid-induced imbalance of osteogenic and adipogenic differentiation, and apoptosis of bone marrow mesenchymal stem cells (BMSCs). An increasing number of genes, especially noncoding RNAs, have been implicated in the function of BMSCs. Our previous studies have confirmed the key role of LINC00473 and miR-23a-3p on the osteogenic, adipogenic differentiation, and apoptosis of BMSCs. However, the underlying mechanism of this process is still unclear. Based on bioinformatics analysis, here we investigated the effects of LINC00473 on the LRP5/Wnt/ß-catenin signaling pathway in the osteogenesis and adipogenesis of BMSCs, as well as the PEBP1/Akt/Bad/Bcl-2 signaling pathway in dexamethasone- (Dex-) induced apoptosis of BMSCs. Our data showed that LINC00473 could promote osteogenesis and suppress the adipogenesis of BMSCs through the activation of the miR-23a-3p/LRP5/Wnt/ß-catenin signaling pathway axis, while rescuing BMSCs from Dex-induced apoptosis by activating the miR-23a-3p/PEBP1/Akt/Bad/Bcl-2 signaling pathway axis. Notably, we observed that LINC00473 interacted with miR-23a-3p in an Argonaute 2 (AGO2)-dependent manner based on dual-luciferase reporter assay, AGO2-related RNA immunoprecipitation, and RNA antisense purification assay. Furthermore, injectable thermosensitive polylactic-co-glycolic acid (PLGA) hydrogel loaded with rat-derived BMSCs (rBMSCs) modified by LINC00473 were used for the treatment of SONFH in a rat model. Our results demonstrated that PLGA hydrogels provided a suitable environment for harboring rBMSCs. Besides, transplantation of PLGA hydrogels loaded with rBMSCs modified by LINC00473 could significantly promote the bone repair and reconstruction of the necrotic area at the femoral head in our SONFH rat model. Surprisingly, compared with the transplantation of BMSCs alone, the transplanted rBMSCs encapsulated within the PLGA hydrogel could migrate from the medullary cavity to the femoral head. In summary, LINC00473 promoted osteogenesis, inhibited adipogenesis, and antagonized Dex-induced apoptosis of BMSCs. Therefore, LINC00473 could provide a new strategy for the treatment of SONFH.

Comparisons between Direct Anterior Approach and Lateral Approach for Primary Total Hip Arthroplasty in Postoperative Orthopaedic Complications: A Systematic Review and Meta-Analysis.

The direct anterior approach (DAA) are attracting increasing attention from orthopedic arthroplasty surgeons, due to the less blood loss, mild soft tissue invasion, rapid rehabilitation and shorter length of stay. However, the longer learning curve in DAA can give rise to several complications, such as intraoperative femoral fracture, lateral femoral cutaneous nerve injury, wound-healing problem, premature revision and so on. This meta-analysis was performed to compare the rate of postoperative orthopedic complications between the DAA and the lateral approach (LA). All studies involving the comparison of postoperative orthopedic complications after THA between the DAA and LA group were searched in 7 databases prior to October 2020. The odds ratio (OR) with the 95% confidence intervals (CI) for each outcome was calculated by using the RevMan 5.3. The methodological bias of included studies was evaluated and the potential heterogeneity sources were analyzed. Thirteen comparative studies including a total of 24853 hips (9575 hips in the DAA group and 15278 hips in the LA group) were eligible for this meta-analysis. There was no significant difference in the rate of surgical site infection [2.59% vs 2.14% (OR = 0.98; 95% CI: 0.59-1.61, P = 0.93)], heterotopic ossification [12.16% vs 26.47% (OR = 0.46; 95% CI: 0.20-1.07, P = 0.07)] and reoperation [2.70% and 2.11% respectively (OR = 0.93; 95% CI: 0.68-1.26, P = 0.64)] between the DAA and LA groups. Although a lower rate in prosthesis malposition [36.19% vs 54.86% (OR = 0.50; 95% CI: 0.35-0.73, P = 0.0003)], leg length discrepancy [1.87% vs 2.37% (OR = 2.35; 95% CI: 1.30-4.25, P = 0.005)] and Trendelenburg gait [1.68% vs 4.78% (OR = 0.29; 95% CI: 0.13-0.65, P = 0.003)] was observed in the DAA group, a higher rate in dislocation [0.77% vs 0.18% (OR = 3.73; 95% CI: 2.35-5.94, P< 0.00001)], periprosthetic fracture [1.05% vs 0.41% (OR = 2.38; 95% CI: 1.58-3.58, P< 0.0001)], prosthesis loosening [0.61% vs 0.37% (OR = 1.66; 95% CI: 1.05-2.62, P = 0.03)] and nerve injury [0.95% vs 0% (OR = 7.12; 95% CI: 1.66-30.48, P = 0.008)] was found in the DAA group. This meta-analysis demonstrated several evidences indicating that the DAA exhibited the advantages in the accurate prosthesis placement and less damage of surrounding hip musculature. However, a higher rate in dislocation, periprosthetic fracture, prosthesis loosening and nerve injury in the DAA group should be paid more attention, due to the limited exposure and a longer learning curve, compared to the LA.

Effects of the Local Bone Renin-Angiotensin System on Titanium-Particle-Induced Periprosthetic Osteolysis.

Wear particles may induce osteoclast formation and osteoblast inhibition that lead to periprosthetic osteolysis (PPOL) and subsequent aseptic loosening, which is the primary reason for total joint arthroplasty failure. Local bone renin-angiotensin system (RAS) has been found to participate in the pathogenic process of various bone-related diseases via promoting bone resorption and inhibiting bone formation. However, it remains unclear whether and how local bone RAS participates in wear-particle-induced PPOL. In this study, we investigated the potential role of RAS in titanium (Ti) particle-induced osteolysis in vivo and osteoclast and osteoblast differentiation in vitro. We found that the expressions of AT1R, AT2R and ACE in the interface membrane from patients with PPOL and in calvarial tissues from a murine model of Ti-particle-induced osteolysis were up-regulated, but the increase of ACE in the calvarial tissues was abrogated by perindopril. Moreover, perindopril mitigated the Ti-particle-induced osteolysis in the murine model by suppressing bone resorption and increasing bone formation. We also observed in RAW264.7 macrophages that Ang II promoted but perindopril suppressed Ti-particle-induced osteoclastogenesis, osteoclast-mediated bone resorption and expression of osteoclast-related genes. Meanwhile, Ang II enhanced but perindopril repressed Ti-particle-induced suppression of osteogenic differentiation and expression of osteoblast-specific genes in mouse bone marrow mesenchymal stem cells (BMSCs). In addition, local bone RAS promoted Ti-particle-induced osteolysis by increasing bone resorption and decreasing bone formation through modulating the RANKL/RANK and Wnt/ß-catenin pathways. Taken together, we suggest that inhibition of RAS may be a potential approach to the treatment of wear-particle-induced PPOL.

The Novel Curcumin Derivative 1g Induces Mitochondrial and ER-Stress-Dependent Apoptosis in Colon Cancer Cells by Induction of ROS Production.

Reactive oxygen species (ROS) play an important role in cellular metabolism. Many chemotherapeutic drugs are known to promote apoptosis through the production of ROS. In the present study, the novel curcumin derivative, 1g, was found to inhibit tumor growth in colon cancer cells both in vitro and in vivo. Bioinformatics was used to analyze the differentially expressed mRNAs. The mechanism of this effect was a change in mitochondrial membrane potential caused by 1g that increased its pro-apoptotic activity. In addition, 1g produced ROS, induced G1 checkpoint blockade, and enhanced endoplasmic reticulum (ER)-stress in colon cancer cells. Conversely, pretreatment with the ROS scavenging agent N-acetyl-l-cysteine (NAC) inhibited the mitochondrial dysfunction caused by 1g and reversed ER-stress, cell cycle stagnation, and apoptosis. Additionally, pretreatment with the p-PERK inhibitor GSK2606414 significantly reduced ER-stress and reversed the apoptosis induced by colon cancer cells. In summary, the production of ROS plays an important role in the destruction of colon cancer cells by 1g and demonstrates that targeted strategies based on ROS represent a promising approach to inhibit colon cancer proliferation. These findings reveal that the novel curcumin derivative 1g represents a potential candidate therapeutics for the treatment of colon cancer cells, via apoptosis caused by mitochondrial dysfunction and endoplasmic reticulum stress.

Icariin stimulates osteogenesis and suppresses adipogenesis of human bone mesenchymal stem cells via miR-23a-mediated activation of the Wnt/ß-catenin signaling pathway.

BACKGROUND: Icariin (ICA) is a bioactive compound isolated from epimedium-derived flavonoids that modulates bone mesenchymal stem cell osteogenesis and adipogenesis. However, its precise mechanism in this process is unknown. PURPOSE: The purpose of this study was to elucidate the role of ICA on human bone mesenchymal stem cell (hBMSC) osteogenesis and adipogenesis by focusing on miR-23a mediated activation of the Wnt/ß-catenin signaling pathway. METHODS: After ICA treatment, hBMSC osteogenesis and adipogenesis were evaluated using alkaline phosphatase staining, an alkaline phosphatase activity assay, Oil Red O staining, and cellular triglyceride levels. Moreover, the mRNA and protein expression levels of osteogenic and adipogenic markers as well as key factors of the Wnt/ß-catenin signaling pathway were measured using quantitative reverse transcription polymerase chain reaction and western blotting. Lithium chloride, an activator of the Wnt/ß-catenin signaling pathway, was used as a positive control. Finally, to investigate the role of miR-23a in ICA-induced activation of the Wnt/ß-catenin signaling pathway, hBMSCs were transfected with miR-23a mimics or a miR-23a inhibitor. RESULTS: ICA significantly promoted hBMSC osteogenic differentiation by upregulating alkaline phosphatase activity and the expression of bone sialoprotein II (BSPII) and runt-related transcription factor-2 (Runx-2). In contrast, ICA inhibited hBMSC adipogenic differentiation by reducing lipid droplet formation and cellular triglyceride levels as well as by downregulating the expression of peroxisome proliferator-activated receptor-γ (PPAR-γ) and CCAAT enhancer-binding protein-α (C/EBP-α). ICA mediated its effects on hBMSCs by activating the Wnt/ß-catenin signaling pathway. It did so by upregulating ß-catenin, low density lipoprotein receptor-related protein 5 (LRP5), and T cell factor 1 (TCF1). Notably, the up-regulation of these proteins was blocked by Dickkopf-related protein 1 (DKK1). Critically, the effects of ICA on hBMSCs were similar to that of the positive control, lithium chloride. Notably, ICA-induced activation of the Wnt/ß-catenin signaling pathway was significantly attenuated following miR-23a up-regulation. Conversely, miR-23a downregulation affected hBMSCs in the same manner as ICA; i.e., it activated the Wnt/ß-catenin signaling pathway. CONCLUSION: ICA promotes and inhibits, respectively, hBMSC osteogenesis and adipogenesis via miR-23a-mediated activation of the Wnt/ß-catenin signaling pathway.

Correlation between growth differentiation factor 5 (rs143383) gene polymorphism and knee osteoarthritis: an updated systematic review and meta-analysis.

BACKGROUND: A great deal of evidence has supported that growth differentiation factor 5 (GDF5) is associated with the occurrence of knee osteoarthritis (KOA), while their results are not consistent. In the present study, we aimed to explore the association between GDF5 gene polymorphism and KOA for a more credible conclusion. METHODS: Comprehensive literature searches were carried out in English databases, including PubMed, Embase, Web of Science (WOS), and Cochrane, and Chinese databases, including China National Knowledge Infrastructure (CNKI), WANFANG, and VIP database. After the data were extracted from the required studies, the odds ratios (ORs) and their 95% confidence intervals (CIs) were determined to assess the correlation between GDF5 gene polymorphism and KOA. The publication bias was evaluated by funnel plot. RESULTS: According to the inclusion and exclusion criteria, 15 studies on the correlation between GDF5 gene polymorphism and KOA occurrence were eligible for meta-analysis. Among these articles, four studies showed no apparent correlation, while the other 11 studies indicated an obvious correlation. Meanwhile, we also carried out a subgroup analysis of the population. Due to the inevitable heterogeneity, three genetic models were finally selected for analysis. With the allele model (C versus T: OR = 0.79, 95% CI = 0.73~0.87), recessive model (CC versus CT + TT: OR = 0.76, 95% CI = 0.68~0.86), and homozygous model (CC versus TT: OR = 0.66, 95% CI = 0.58~0.76), GDF5 gene polymorphism decreased the risk of KOA. Besides, a significant association was observed in Caucasians, Asians, and Africans. Meanwhile, the protective effect of genotype C (or CC) in the Asian group was little obvious than that in the Caucasian group and the African group. Although the quality of the included studies was above medium-quality, we obtained results with a low level of evidence. CONCLUSIONS: The results of the meta-analysis showed that the genotype C (or CC) of GDF5 protected against KOA occurrence in Caucasian, Asian, and African populations.

Differential expression profiles of long noncoding RNAs and mRNAs in human bone marrow mesenchymal stem cells after exposure to a high dosage of dexamethasone.

BACKGROUND: Abnormalities in apoptosis, cell cycle, proliferation, and differentiation of human bone marrow mesenchymal stem cells (hBMSCs) significantly impact bone metabolism and remodeling, resulting in various skeletal disorders. Long-term exposure to a high dosage of dexamethasone (Dex) induces apoptosis and inhibits the proliferation of mesenchymal stromal cells (MSCs), which are probable primary causes of various skeletal disorders. However, to date, the exact mechanisms of action of Dex on hBMSCs have not been fully elucidated. METHODS: To explore the effects of Dex on apoptosis, cell cycle, proliferation, senescence, osteogenic and adipogenic differentiation of hBMSCs at the various exposure times and concentrations, Hoechst 33342/PI staining, flow cytometry, crystal violet assay, ß-galactosidase (ß-GAL) activity assay, alizarin red S (ARS) staining assay, and Oil Red O (ORO) staining assay were performed. A microarray assay was used to identify differentially expressed lncRNAs and mRNAs in 10- 6 mol/L Dex-treated hBMSCs, and a bioinformatics analysis was conducted to further explore the role of these differentially expressed lncRNAs and mRNAs in the coding and noncoding (CNC) network. Furthermore, the microarray results were validated using quantitative real-time PCR (qRT-PCR) analysis. RESULTS: Over the range of 10-8, 10-7, and 10-6 mol/L, Dex induced apoptosis, arrest of the cell cycle, inhibition of osteogenic differentiation, and promotion adipogenic differentiation of the hBMSCs in a dose-dependent manner. In addition, 10-6 mol/L Dex significantly induced apoptosis, suppressed proliferation, and increased the senescence of hBMSCs in a time-dependent manner. Interestingly, this time-dependent effect of Dex on the apoptosis of hBMSCs plateaued at the 7th day and decreased from the 8th day to the 10th day, while Dex treatment increased senescence of the hBMSCs on the 6th day. Furthermore, the microarray analysis identified a total of 137 differentially expressed mRNAs (90 upregulated and 47 downregulated) and 90 differentially expressed lncRNAs (61 upregulated and 29 downregulated) in hBMSCs after exposure to 10-6 mol/L Dex. The differentially expressed mRNAs and lncRNAs were associated with the regulation of cell apoptosis, proliferation, and cell cycle. Meanwhile, several signaling pathways involved in these processes, including the mTOR signaling pathway, Ras signaling pathway, HIF-1 signaling pathway, NF-kappa B signaling pathway, and TGF-beta signaling pathway, also were identified through the interaction net in the significant pathways (Path-Net) analysis. Furthermore, the CNC network further identified 78 core regulatory genes involved in the regulation of apoptosis. Additionally, qRT-PCR was used to confirm the identity of the key differentially expressed mRNAs and lncRNAs found to be closely associated with cell apoptosis to confirm the reliability of the microarray dataset. CONCLUSIONS: In summary, the effect of Dex on apoptosis, cell cycle, proliferation, and osteogenic differentiation and adipogenic differentiation of the hBMSCs depended on exposure time and concentration. Continuous exposure to 10-6 mol/L of Dex for 7 days may be a suitable protocol for inducing the apoptosis of hBMSCs. Under this protocol, differentially expressed lncRNAs and mRNAs associated with apoptosis, cell cycle, and proliferation were identified, providing a new research direction for further studies.

LINC00473 rescues human bone marrow mesenchymal stem cells from apoptosis induced by dexamethasone through the PEBP1­mediated Akt/Bad/Bcl­2 signaling pathway.

The inhibition of the proliferation and apoptosis of bone marrow­derived mesenchymal stem cells (BMSCs) triggered by the excessive use of glucocorticoids, is considered a potential mechanism for the pathogenesis of steroid­induced osteonecrosis of the femoral head (SONFH). Long non­coding RNAs (lncRNAs) have been proven to influence the proliferation, apoptosis and differentiation of BMSCs by regulating the expression of critical genes. A previous microarray analysis by the authors confirmed the significant downregulation of LINC00473 in human BMSCs (hBMSCs) from patients with SONFH. However, the underlying role and molecular mechanisms of LINC00473 on dexamethasone (Dex)­stimulated hBMSCs remains unknown. In the present study, the expression of LINC00473 was determined in the hBMSCs of patients with SONFH and control patients. In addition, the protective effects and underlying molecular mechanisms of LINC00473 in Dex­stimulated hBMSCs were investigated. The results revealed that LINC00473 expression was significantly downregulated in hBMSCs from patients with SONFH compared with the controls, and that the upregulation of LINC00473 attenuated the inhibitory effects exerted by 1 µM Dex on the proliferation and apoptosis of hBMSCs. Moreover, the upregulation of LINC00473 significantly promoted the protein expression of phosphorylated (p­)Akt, p­Bcl­2­associated death promoter (p­Bad) and B­cell lymphoma 2 (Bcl­2), whereas it decreased the cleavage of caspase­3, thus preventing the Dex­induced apoptosis of hBMSCs. Of note, the regulatory effects of LINC00473 on the Akt/Bad/Bcl­2 signaling pathway and its anti­apoptotic effects were similar to those of SC79 (an Akt activator), and were inhibited by MK­2206 (an Akt inhibitor). In further experiments, it was found that the upregulation of LINC00473 markedly promoted the phosphorylation of Akt in Dex­stimulated hBMSCs, and increased the protein level of phosphatidylethanolamine­binding protein 1 (PEBP1). Alternatively, the promoting effect on Akt phosphorylation induced by LINC00473 was significantly attenuated following the knockdown of PEBP1. Furthermore, the upregulation of PEBP1 triggered a marked increase in the levels of Akt phosphorylation in Dex­stimulated hBMSCs, which was line with the upregulation of LINC00473. Taken together, the results of the present study demonstrate that LINC00473 has the ability to rescue hBMSCs from Dex­induced apoptosis through the PEBP1­mediated activation of the Akt/Bad/Bcl­2 signaling pathway.

Identification of long non­coding RNAs expressed during the osteogenic differentiation of human bone marrow­derived mesenchymal stem cells obtained from patients with ONFH.

Long non­coding RNAs (lncRNAs) are crucial for the occurrence and development of numerous diseases. Although lncRNAs are involved in the biological activities of stem cells and play crucial roles in stem cell differentiation, the expression of specific lncRNAs during human bone marrow­derived mesenchymal stem cell (hBMSC) osteogenic differentiation in osteonecrosis of the femoral head (ONFH) and their regulatory roles have not yet been fully elucidated. To the best of our knowledge, the present study is the first to characterize lncRNA expression profiles during hBMSC osteogenic differentiation in ONFH using microarray analysis and RT­qPCR to confirm the microarray data. A total of 24 downregulated and 24 upregulated lncRNAs were identified and the results of RT­qPCR were found to be consistent with those of microarray analysis. Bioinformatics analyses, using the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases, were conducted to explore the possible mechanisms and identify the signaling pathways that the lncRNAs are involved in. GO analysis revealed significant changes in the intracellular organelle, Ras protein signal transduction and transferase activity. KEGG pathway analysis revealed that the lncRNAs were closely associated with fatty acid metabolism, apoptosis and the TGF­ß signaling pathway. The overexpression of MAPT antisense RNA 1 (MAPT­AS1) was found to promote osteogenesis and inhibit the adipogenesis of hBMSCs at the cellular and mRNA levels. On the whole, the findings of the present study identified the lncRNAs and their roles in hBMSCs undergoing osteogenic differentiation in ONFH and provide a new perspective for the pathogenesis of ONFH.

LINC00473 regulated apoptosis, proliferation and migration but could not reverse cell cycle arrest of human bone marrow mesenchymal stem cells induced by a high-dosage of dexamethasone.

Dysfunction of bone marrow mesenchymal stem cells (BMSCs) is involved in the pathogenesis of steroid-induced osteonecrosis of the femoral head (SONFH). Long noncoding RNAs (lncRNAs) contribute to biological effects exerted on BMSCs by regulating the expression of genes. However, most recent studies have focused on the role of lncRNAs in modulating the imbalance between osteogenic and adipogenic differentiation but not apoptosis, proliferation, cell cycle and migration of BMSCs, especially in Dex-treated BMSCs. In this study, we conducted a microarray analysis to investigate the differential expression profiles of lncRNAs between human BMSCs (hBMSCs) obtained from patients with SONFH and control patients with femoral neck fracture. The microarray analysis showed that a total of 48 differentially expressed lncRNAs were identified in hBMSCs between the two groups, including 24 upregulated lncRNAs and 24 downregulated lncRNAs. Among of them, LINC00473 was found to be significantly downregulated. In the following study, we found that 10-6 mol/L Dex significantly inhibited proliferation, arrested cell cycle at the G1 phase, increased caspase-3 activity, induced apoptosis and impeded the migration of hBMSCs, while downregulation of the expression of LINC00473 produced results that were in line with the results of the microarray analysis in a time-dependent manner. Interestingly, upregulation of LINC00473 attenuated the negative effects caused by 10-6 mol/L Dex on hBMSCs, except for cell cycle arrest. Furthermore, it should be noted that LINC00473 had no effect on the proliferation and cell cycle of hBMSCs in the absence of Dex. Collectively, our data revealed that LINC00473 attenuated apoptosis, promoted the proliferation and migration of Dex-induced hBMSCs, which are not involved in interference with the cell cycle of hBMSCs.

Stem cell therapy for osteonecrosis of femoral head: Opportunities and challenges.

Osteonecrosis of the femoral head (ONFH) is a progressive disease with a complex etiology and unclear pathogenesis, resulting in severe hip pain and dysfunction mainly observed in young patients. Although total hip arthroplasty (THA) is the most effective treatment for patients with ONFH in the terminal stage, the results of THA in young patients or active populations are often not favorable, with some complications related to the prosthesis. With the development of biotechnology, an increasing number of studies pay attention to use of stem cells for the treatment of ONFH. Stem cells are characterized by the ability to self-renew and differentiate into multiple cell types, including differentiation into osteoblasts and endothelial cells to mediate bone repair and angiogenesis. Furthermore, stem cells can offer growth factors to promote blood supply in the necrotic regions by paracrine effects. Therefore, stem cell therapy has become one of the hip-preserving alternatives for ONFH. This review summarized the current trends in stem cell therapy for ONFH, from clinical applications to related basic research, and showed that an increasing number of studies have confirmed the effectiveness of stem cell therapy in ONFH. However, many unsolved problems and challenges in practical applications of stem cell therapy still exist, such as patient selection, standardized procedures, safety assessment, and the fate of transplanted cells in the body. Additional studies are required to find ideal cell sources, appropriate transplantation methods, and the optimal number of cells for transplantation.

Hip survival rate in the patients with avascular necrosis of femoral head after transtrochanteric rotational osteotomy: a systematic review and meta-analysis.

BACKGROUND: The clinical outcome of transtrochanteric rotational osteotomy (TRO) for osteonecrosis of the femoral head (ONFH) remains controversial, and the promising clinical results of several Japanese studies could not be reproduced in American and European studies. Trying to solve controversies on TRO for ONFH rising from apparently conflicting studies, a meta-analysis was conducted to assess the 5- and 10-year hip survival rates (with conversion to artificial joint replacement and radiographic failure as endpoints) after TRO. METHODS: All eligible studies were searched in seven comprehensive databases including PubMed, Web of Science, Embase, Cochrane Library, VIP Database, China Knowledge Resource Integrated Database, and Wan Fang Database prior to June 2019. The outcomes evaluated were 5- and 10-year hip survival rates after TRO. The odds ratio and risk difference for the non-comparative binary data with the 95% confidence intervals (CIs) were calculated for each outcome. The included studies were assessed for methodologic bias and potential reasons for heterogeneity were explored. RESULTS: Nineteen studies of TRO for ONFH were eligible for this meta-analysis according to inclusion criteria. Based on the previous report, two calculation methods (Methods 1 and 2) were adopted in this meta-analysis. Furthermore, we performed a sub-group analysis of the 5- and 10-year hip survival rates (Method 1) after TRO for ONFH: Asian sub-population and non-Asian sub-population. Taking conversion to artificial joint replacement as the endpoint, 5- and 10-year hip survival rates (Method 1) after TRO for ONFH in the Asian population were 0.86 (95% CI = 0.82-0.89) and 0.72 (95% CI = 0.65-0.78), respectively, and 5- and 10-year hip survival rates after TRO for ONFH in the non-Asian population were 0.55 (95% CI = 0.43-0.67) and 0.42 (95% CI = 0.28-0.55), respectively. The 5- and 10-year hip survival rates (Method 2) after TRO for ONFH were 0.90 (95% CI = 0.79-0.95) and 0.89 (95% CI = 0.81-0.94), respectively. Taking radiographic failure as the endpoint, 5- and 10-year hip survival rates after TRO for ONFH were 0.70 (95% CI = 0.64-0.76) and 0.53 (95% CI = 0.46-0.61), respectively. CONCLUSIONS: The 5- and 10-year hip survival rates after TRO for ONFH were satisfactory in the Asian population, and were acceptable in the non-Asian population despite high early failure rates.

Epimedium-derived flavonoids modulate the balance between osteogenic differentiation and adipogenic differentiation in bone marrow stromal cells of ovariectomized rats via Wnt/ß-catenin signal pathway activation.

OBJECTIVE: To observe the function of wnt/ß-catenin signal pathway on the process that epimedium-derived flavonoids (EFs) regulate the balance between osteogenic differentiation and adipogenic differentiation in bone marrow stromal cells of ovariectomized rats, and to provide an experimental evidence for the mechanism of EFs on treating postmenopausal osteoporosis. METHODS: Bone marrow stromal cells from ovariectomized rats were separated and cultivated in the condition of osteoinductive medium or liquid medium for 15 days. Low- (1 µg/mL), medium- (10 µg/mL) and high- (100 µg/mL) dose EFs were administrated correspondingly. Alkaline phosphatase (ALP) staining, ALP activity determination, oil red O staining and realtime polymerese chain reaction (RT-PCR) were used to determine the effect of EFs on osteogenic differentiation and adipogenic differentiation in bone marrow stromal cells of ovariectomized rats. Moreover, in order to explore the mechanism of EFs on osteogenic differentiation and adipogenic differentiation in bone marrow stromal cells of ovariectomized rats, Dickkopf-related protein 1 (DKK1) was used in the medium group. Enzymelinked immunosorbent assay (ELISA) and RT-PCR were used to determine mRNA levels of ß-catenin, low density lipoprotein receptor-related protein 5 (LRP5) and T cell factor (TCF) protein, known as wnt/ß-catenin signal pathway related factors. RESULTS: EFs increased mRNA expression levels of ALP and early osteoblast differentiation factors, such as runt-related transcription factor 2 (Runx2), osteocalcin and collagen I, and decreased mRNA expression levels of fat generation factors, such as peroxisome proliferator activated receptor gamma 2 (PPARγ-2) and CCAAT enhancer-binding protein-α (C/EBPα) in a dose-dependent manner. While osteoblast differentiation factors were down-regulated, fat generation factors were up-regulated when DKK1 was applied. Also EFs up-regulated mRNA expression levels of ß-catenin, LRP5 and TCF protein which could be blocked by DKK1. CONCLUSION: EFs regulate the balance between osteogenic differentiation and adipogenic differentiation in bone marrow stromal cells of ovariectomized rats by activating wnt/ß-catenin signal pathway, which may be an important molecular mechanism of EFs on treating postmenopausal osteoporosis.

Dynamic expression of DKK1 protein in the process whereby Epimedium-derived flavonoids up-regulate osteogenic and down-regulate adipogenic differentiation of bone marrow stromal cells in ovariectomized rats.

OBJECTIVE: To observe the dynamic expression of DKK1 protein in the process whereby Epimedium-derived flavonoids (EFs) regulate the balance between osteogenic and adipogenic differentiation of bone marrow stromal cells in ovariectomized rats, and to provide experimental evidence for the mechanism of EFs in the treatment of postmenopausal osteoporosis. METHODS: Bone marrow stromal cells from ovariectomized rats were separated and cultivated in osteoinductive or liquid medium for 15 days in vitro. EFs (10 µg/mL) were applied to both cultures. Alkaline phosphatase (ALP) staining, ALP activity determination, Oil Red O staining and fluorescence quantitative polymerase chain reaction were used to determine the influence of EFs on osteogenic and adipogenic differentiation of bone marrow stromal cells in ovariectomized rats. Moreover, in order to explore the exact mechanism of EFs on osteogenic and adipogenic differentiation of bone marrow stromal cells in ovariectomized rats, enzyme linked immunosorbent assay was used to determine the dynamic expression of DKK1 protein in this process. RESULTS: EFs increased activity of ALP and mRNA expression of Runx2 (early osteoblast differentiation factor) and decreased mRNA expression of PPARγ-2 (key factor of fat generation). Importantly, EFs down-regulated expression of DKK1 protein in an osteogenic induction medium and inhibited up-regulation of DKK1 protein in an adipogenic induction medium. CONCLUSION: EFs regulate the balance between osteogenic and adipogenic differentiation of bone marrow stromal cells in ovariectomized rats by down-regulating expression of DKK1 protein. This may be an important molecular mechanism of EFs in the context of treatment of postmenopausal osteoporosis.

[The expression and significance of Wnt/beta-catenin signal pathway protein in the effect of bushen huoxue granule containing serum on the osteoblast].

OBJECTIVE: To investigate the effect of Wnt/beta-catenin signal pathway protein in the effect of Bushen Huoxue Granule (BHG) containing serum on the osteoblast, and to provide necessary experimental reliance for its action of mechanism in treatment of osteoporosis. METHODS: The osteoblast from cranial bones of neonates rat were isolated and cultured in vitro, which was divided into the blank control group and the BHG containing serum group. The alkaline phosphatase (ALP) activities of the osteoblast in each group were quantitatively detected and the ALP staining was performed six days later. The alizarin red staining was performed eighteen days later. At the same time, levels of Wnt/beta-catenin signal pathway protein--beta-catenin, low density lipoprotein correlated protein 5 (LRP 5), and T cell factor (TCF) of osteoblasts in each group were detected by ELISA. RESULTS: BHG containing serum could significantly increase the expression of ALP and promote the formation of mineralizing nodus in the osteoblasts. At the same time it also markedly up-regulated the expressions of p-catenin, LRP 5, and TCF in this process. CONCLUSION: BHG containing serum could markedly increase ossify activities and mineralization of osteoblast. This action was closely correlated with Wnt/p-catenin signal pathway. So it indicated that Wnt/beta-catenin signal pathway played a very important role in the treatment of the osteoporosis by BHG.