Synovial fluid exosome-derived miR-182-5p alleviates osteoarthritis by downregulating TNFAIP8 and promoting autophagy through LC3 signaling.

OBJECTIVE: To investigate the role of exosomal miRNAs from synovial fluid (SF) in osteoarthritis (OA) patients and investigate the underlying molecular mechanism. METHODS: Degenerated knee tissues were collected from male and female OA patients. Enzyme-linked immunosorbent assay (ELISA) was used to detect the differences in the expression of inflammatory indicators, including TNF-α, IL-6, and IL-10, between the degenerative and injury groups. Exosomes were isolated from SF using the Exoquick kit, and a microarray was used to identify differentially expressed miRNAs (DEmiRNAs), which were analyzed using bioinformatics. The predicted relationship between DEmiRNAs and target genes was verified using a luciferase reporter gene assay. CCK-8 and transwell assays were used to assess cell viability and migration. Immunofluorescence and TUNEL assay were used to detect cell autophagy and apoptosis. The interaction between proteins was detected by immunoprecipitation and verified by Mab rescue assay. RESULTS: The relative expression of TNF-α/IL6 was significantly higher in the degeneration group than in the injury group. The OA degeneration group released significantly more and smaller exosomes than the injury group. The expression of miR-182-5p was markedly reduced in OA patients and had a higher correlation with inflammatory indicators. Tumor necrosis factor α-induced protein 8 (TNFAIP8) was a target of miR-182-5p, and its overexpression promoted chondrocyte proliferation, migration, and invasion and enhanced the wound healing efficiency. We also found a direct interaction of TNFAIP8 with autophagy-related gene 3 (ATG3). TNFAIP8 triggered ATG3 LC3-mediated autophagy. CONCLUSION: The downregulation of exosomal miR-182-5p inhibits OA degeneration by targeting TNFAIP8 via the ATG/LC3 pathway.

Immunoregulation of synovial macrophages for the treatment of osteoarthritis.

Osteoarthritis (OA) is the most common joint disease affecting approximately 10% of men and 18% of women older than 60. Its pathogenesis is still not fully understood; however, emerging evidence has suggested that chronic low-grade inflammation is associated with OA progression. The pathological features of OA are articular cartilage degeneration in the focal area, including new bone formation at the edge of the joint, subchondral bone changes, and synovitis. Conventional drug therapy aims to prevent further cartilage loss and joint dysfunction. However, the ideal treatment for the pathogenesis of OA remains to be defined. Macrophages are the most common immune cells in inflamed synovial tissues. In OA, synovial macrophages undergo proliferation and activation, thereby releasing pro-inflammatory cytokines, including interleukin-1 and tumor necrosis factor-α, among others. The review article discusses (1) the role of synovial macrophages in the pathogenesis of OA; (2) the progress of immunoregulation of synovial macrophages in the treatment of OA; (3) novel therapeutic targets for preventing the progress of OA or promoting cartilage repair and regeneration.

LINC00926 is involved in hypoxia-induced vascular endothelial cell dysfunction via miR-3194-5p regulating JAK1/STAT3 signaling pathway.

Vascular endothelial cell (VEC) dysfunction is associated with the development of coronary heart disease (CHD). Long intergenic non-protein coding RNA 926 (LINC00926), a kind of long noncoding RNA (lncRNA), has been found to be abnormally expressed in CHD patients. However, the biological role of LINC00926 has not been reported. In our research, we intended to explore the regulatory mechanism of LINC00926 in hypoxia-exposed HUVEC cells (HUVECs). In our in vitro study, HUVECs were exposed under hypoxic conditions (5% O2) for 24 h. RT-qPCR and Western blotting assay were used to detect the mRNA and protein levels. CCK-8 assay, flow cytometry, transwell assay and in vitro angiogenesis assay were performed to measure cell proliferation, apoptosis, migration and tube formation, respectively. Bioinformatics analysis was applied to predict the target of LINC00926 and miR-3194-5p, which was verified by dual-luciferase reporter assays. The results showed that LINC00926 was highly expressed in CHD patients and hypoxia-exposed HUVECs. LINC00926 overexpression suppressed cell proliferation, migration and tube formation and increased cell apoptosis. MiR-3194-5p was a target of LINC00926 and can target binding to JAK1 3'UTR. LINC00926 could up-regulate JAK1 and p-STAT3 levels via miR-3194-5p. In addition, overexpressed LINC00926 suppressed cell proliferation, migration and tube formation and increased cell apoptosis via miR-3194-5p/JAK1/STAT3 axis. In summary, LINC00926 aggravated endothelial cell dysfunction via miR-3194-5p regulating JAK1/STAT3 signaling pathway in hypoxia-exposed HUVECs.

Erratum: IRF7 inhibits the Warburg effect via transcriptional suppression of PKM2 in osteosarcoma: Erratum.

[This corrects the article DOI: 10.7150/ijbs.65255.].

IRF7 inhibits the Warburg effect via transcriptional suppression of PKM2 in osteosarcoma.

Osteosarcoma (OS) is a malignant bone tumor among adolescents and young adults. IRF7 belongs to the transcription factor family of interferon regulatory factors (IRFs) and has previously been described to function as a tumor suppressor in multiple cancer types. However, the biological functions and cellular mechanism of IRF7 in OS remain elusive. In this study, by quantitative real-time PCR (qRT-PCR) and western blotting, we found that IRF7 was downregulated in OS, and the higher expression of IRF7 was correlated with a better survival prognosis. Moreover, loss-of-function and gain-of-function studies have proved the critical functions of IRF7 in suppressing aerobic glycolysis of osteosarcoma cells as evidenced by glucose uptake, lactate production, extracellular acidification rate, and oxygen consumption rate. Mechanistically, IRF7 inhibited the expression of key glycolytic gene PKM2 via direct transcriptional regulation. Moreover, the in vitro and in vivo tumor-suppressive roles of IRF7 were uncovered in OS and these effects were largely glycolysis-dependent. Therefore, our study unveils a previous unprecedented role of IRF7 in glucose metabolism reprogram and suggests that IRF7 might serve as a potential therapeutic target for patients with OS.

TMED3/RPS15A Axis promotes the development and progression of osteosarcoma.

BACKGROUND: Osteosarcoma is a primary malignant tumor that mainly affects children and young adults. Transmembrane emp24 trafficking protein 3 (TMED3) may be involved in the regulation of malignant cancer behaviors. However, the role of TMED3 in osteosarcoma remains mysterious. In this study, the potential biological function and underlying mechanism of TMED3 in progression of osteosarcoma was elaborated. METHODS: The expression of TMED3 in osteosarcoma was analyzed by immunohistochemical staining. The biological function of TMED3 in osteosarcoma was determined through loss-of-function assays in vitro. The effect of TMED3 downregulation on osteosarcoma was further explored by xenograft tumor model. The molecular mechanism of the regulation of TMED3 on osteosarcoma was determined by gene expression profile analysis. RESULTS: The expression of TMED3 in osteosarcoma tissues was significantly greater than that in matched adjacent normal tissues. Knockdown of TMED3 inhibited the progression of osteosarcoma by suppressing proliferation, impeding migration and enhancing apoptosis in vitro. We further validated that knockdown of TMED3 inhibited osteosarcoma generation in vivo. Additionally, ribosomal protein S15A (RPS15A) was determined as a potential downstream target for TMED3 involved in the progression of osteosarcoma. Further investigations elucidated that the simultaneous knockdown of RPS15A and TMED3 intensified the inhibitory effects on osteosarcoma cells. Importantly, knockdown of RPS15A alleviated the promotion effects of TMED3 overexpression in osteosarcoma cells. CONCLUSIONS: In summary, these findings emphasized the importance of TMED3/RPS15A axis in promoting tumor progression, which may be a promising candidate for molecular therapy of osteosarcoma.

MicroRNA-27a alleviates IL-1ß-induced inflammatory response and articular cartilage degradation via TLR4/NF-κB signaling pathway in articular chondrocytes.

Osteoarthritis (OA) is a common disease of the articular cartilage, and inflammatory response and articular cartilage degradation have been implicated in the pathogenesis of OA. In recent years, microRNAs (miRNAs) have been potentially involved in the pathogenesis of OA. However, little is known about the role of miRNAs in the inflammatory response and articular cartilage degradation in OA and the underlying molecular mechanism. In the present study, we analyze miRNA profiles in the articular tissues from OA patients using microarray. miR-27a has attracted considerable interest for its suppressive effects on inflammation. Subsequently, the expression levels of miR-27a were validated in the articular tissues of OA patients and IL-1ß-stimulated chondrocytes. Using this IL-1ß-induced chondrocyte injury model, we found that upregulation of miR-27a suppressed articular cartilage degradation, the reactive oxygen species (ROS) production and inflammatory response as reflected by reductions in pro-inflammatory cytokines, including interleukin (IL)-6 and IL-8 and tumor necrosis factor (TNF)-α. Moreover, toll-like receptor 4 (TLR4), one upstream molecule of NF-κB signaling pathway, was identified as a direct target of miR-27a in chondrocytes. Furthermore, it was demonstrated that overexpression of TLR4 by pcDNA-TLR4 markedly abrogated the inhibitory effects of miR-27a on the inflammatory response and the degeneration of articular cartilage induced by IL-1ß. Our findings suggest that miR-27a may be considered as a potential therapeutic target in the treatment of OA.

Correlation analysis between the magnetic resonance imaging characteristics of osteoporotic vertebral compression fractures and the efficacy of percutaneous vertebroplasty: a prospective cohort study.

BACKGROUND: To explore the relationship between the magnetic resonance imaging (MRI) characteristics of osteoporotic vertebral compression fractures (OVCFs) and the efficacy of percutaneous vertebroplasty (PVP). METHODS: A prospective study was conducted to analyze the clinical and imaging data of 93 patients with OVCFs treated via PVP. A visual analogue scale (VAS), the Oswestry Disability Index (ODI), and the Medical Outcomes Study(MOS) 36-Item short-form health survey (SF-36) were completed before surgery as well as 1 day and 1, 6, and 12 months after surgery. In addition, postoperative complications were recorded. According to the degree and ranges of bone marrow edema on MRI, the patients were divided into three groups: the mild (group A), moderate (group B), and severe (group C) bone marrow edema groups. Pain and dysfunction scores were compared across the three groups of patients before surgery as well as 1 day and 1, 6, and 12 months after surgery. RESULTS: The VAS, ODI, and SF-36 scores showed significant differences (P < 0.05) before and after surgery among the three groups. The ODI and SF-36 scores were significantly different (P < 0.05) at 1 day and 1 month after surgery among the three groups. Groups A and B showed significantly better pain relief than group C. Group B experienced better pain relief than group A. These results indicate that PVP was associated with better pain relief effects among patients with a greater extent of bone marrow edema. The edema ranges of the vertebral fractures were negatively correlated with the postoperative VAS and ODI scores 1 month after surgery, whereas the ranges were positively correlated with postoperative SF-36 scores 1 month after surgery. CONCLUSIONS: PVP is an effective treatment for OVCFs. Better outcomes were observed among patients with severe or moderate bone marrow edema rather than those with mild bone marrow edema. A greater degree of pain relief after PVP was correlated with faster recovery of the postoperative function. However, this correlation gradually became weak over time and disappeared 6 months after surgery. Therefore, PVP should be an option for early stage OVCFs, especially among patients with bone marrow edema signs on MRI.

RETRACTED: Abduction external rotation position in magnetic resonance arthrography for the diagnosis of rotator cuff tears.

OBJECTIVE: This article aims at evaluating the effectiveness of abduction and external rotation (ABER) position used in magnetic resonance (MR) arthrography for diagnosing rotator cuff tears. METHODS: A retrospective analysis was performed using 183 MR arthrography images of shoulder joint. Each patient was either examined in a neutral position or ABER position. Then the imaging results were compared with those diagnostic results obtained from shoulder arthroscopy. Also the specificity, sensitivity, negative predictive value, positive predictive value, and accuracy of MR arthrography in the two positions described above were evaluated. RESULTS: A total of 64 patients were diagnosed with rotator cuff tears using arthroscopy and the diagnostic results include 16 complete rotator cuff tears and 48 partial tears; 47 supraspinatus tendon tears and 17 posterosuperior cuff tears; 22 delamination tears and 26 tears complicated with anteroinferior labrum-ligament complex injuries. The differences in specificity, sensitivity, negative predictive value, positive predictive value and accuracy between neutral position and ABER position using MR arthrography were not statistically significant (all P > 0.05). For diagnosing posterosuperior cuff tears, the sensitivity of ABER position was significantly higher than that of the neutral position (94.12% vs. 64.71%, P = 0.034). For diagnosing delamination tears, the sensitivity and negative predictive value of ABER position were significantly higher than those of the neutral position (P = 0.009 and P = 0.036 respectively). For diagnosing rotator cuff tears complicated with anteroinferior labrum-ligament complex injuries, the sensitivity of ABER position was statistically higher than that of the neutral position (96.15% vs. 73.08%, P = 0.021). CONCLUSION: This study suggests that MR arthrography in ABER position is a superior tool for diagnosing certain types of rotator cuff tears. Apart from that, MR arthrography in ABER position improved the detection rate of posterosuperior cuff tears, delamination tears and rotator cuff tears complicated with anteroinferior labrum-ligament complex injuries.

Analysis of 3-dimensional finite element after reconstruction of impaired ankle deltoid ligament.

We compared four repair techniques for impaired ankle ligament deltoideum, namely Wiltberger, Deland, Kitaoka and Hintermann using a 3-dimensional finite element. We built an ankle ligament deltoideum model, including six pieces of bone structures, gristles and main ligaments around the ankle. After testing the model, we built an impaired ligament deltoideum model plus four reconstruction models. Subsequently, different levels of force on ankles with different flexion were imposed and ankle biomechanics were compared. In the course of bending, from plantar flexion 20° to back flexion 20°, the extortion of talus decreased while the eversion increased. Four reconstruction models failed to bring back the impaired ankle to normal, with an obvious increase of extortion and eversion. The Kitaoka technique was useful to reduce the extortion angle in a consequential manner. Compared with the other three techniques, the Kitaoka technique produced better results for extortion angle and the difference was statistically significant. However, in case of eversion, there was no significant difference among the four techniques (P>0.05). Lateral ligament's stress in all the four models was different from the normal one. When the ankle was imposed with extortion moment of force, stress of anterior talofibular ligament with the Kitaoka reconstruction method was close to that of the complete deltoid ligament. When ankle was imposed with eversion moment of force, stress of anterior talofibular ligament with Kitaoka and Deland reconstruction methods were close to that of the complete deltoid ligament. We concluded that Kitaoka and Deland tendon reconstruction technique could recover impaired ankle deltoid ligament and re-established its normal biomechanics characteristics.

The comparative risk of developing postoperative complications in patients with distal radius fractures following different treatment modalities.

In this study, we performed a network meta-analysis to compare the outcomes of seven most common surgical procedures to fix DRF, including bridging external fixation, non-bridging external fixation, K-wire fixation, plaster fixation, dorsal plating, volar plating, and dorsal and volar plating. Published studies were retrieved through PubMed, Embase and Cochrane Library databases. The database search terms used were the following keywords and MeSH terms: DRF, bridging external fixation, non-bridging external fixation, K-wire fixation, plaster fixation, dorsal plating, volar plating, and dorsal and volar plating. The network meta-analysis was performed to rank the probabilities of postoperative complication risks for the seven surgical modalities in DRF patients. This network meta-analysis included data obtained from a total of 19 RCTs. Our results revealed that compared to DRF patients treated with bridging external fixation, marked differences in pin-track infection (PTI) rate were found in patients treated with plaster fixation, volar plating, and dorsal and volar plating. Cluster analysis showed that plaster fixation is associated with the lowest probability of postoperative complication in DRF patients. Plaster fixation is associated with the lowest risk for postoperative complications in DRF patients, when compared to six other common DRF surgical methods examined.

Involvement of Notch1/Hes signaling pathway in ankylosing spondylitis.

We aimed to investigate the role of Notch1/Hes signaling pathway in the pathogenesis of abnormal ossification of hip ligament in patients with ankylosing spondylitis (AS). 22 AS patients scheduled for artificial hip arthroplasty were randomly chosen as AS group. As controls, we used 4 patients diagnosed with transcervical fracture who underwent hip replacement surgery. Notch1 and Hes mRNA expressions were detected by real-time fluorescent quantitative polymerase chain reaction (RFQ-PCR). Immunohistochemistry (IHC) was used to detect Notch1 and Hes protein expression. Correlation analyses of Notch-l and Hes with AS-related clinical factors were conducted with spearman's correlation analysis and partial correlation analysis. RFQ-PCR results showed significant differences in Notch1 and Hes mRNA expressions between AS group and the control group (all P<0.05). IHC analysis further indicated positive nuclear signals of Notch1 and Hes protein, indicating functional activation of the Notch1 and Hes pathways. Semi-quantitative IHC showed a higher Notch1 and Hes expression levels in AS group compared to the control group (all P<0.05). Correlation analysis suggested that Hes protein expression was positively associated with the clinical course of the disease in AS patients. In conclusion, Notch1 and Hes overexpression was clearly detected in hip joint ligaments of AS patients, Hes protein expression was associated with the clinical course of AS. Taken together, we suggest that signaling pathways mediated by Notch1-Hes may contribute to ligament ossification of hip joints in AS patients.

Role of growth differentiation factor-5 and bone morphogenetic protein type II receptor in the development of lumbar intervertebral disc degeneration.

The present study was designed to evaluate the role of growth differentiation factor-5 (GDF-5) and bone morphogenetic protein type II receptor (BMPR-II) in the development of lumbar intervertebral disc degeneration (IDD). A total of 24 patients with lumbar IDD (experiment group) and 6 patients with lumbar vertebral fracture (control group) were enrolled in the study. Tissue samples of IVD from the experiment group and control group were obtained during lumbar fusion operation, respectively. Fixation and decalcification of IVD tissue were performed, and then HE staining was carried out to observe the morphological changes of the lumbar IVD tissues. The expression of GDF-5 and BMPRII in human lumbar IVD was detected by immunohistochemical staining. HE staining results showed that non- and minimal degeneration was found in 11 cases (score range, 0-3), moderate degeneration in 12 cases (score range, 4-8), and severe degeneration in 7 cases (score range, 9-12). According to the immunohistochemical results, the positive expression rates of GDF-5 and BMPRII in NP were higher than those in AF of the non- and minimal degeneration group, moderate degeneration group and severe degeneration group (all P < 0.05). However, no significant difference in GDF-5 or BMPRII positive expression was observed among the normal, non- and minimal, moderate and severe degeneration groups in neither NP area nor AF area (all P > 0.05). In conclusion, our results showed that GDF-5 and BMPRII expressed both in normal and degenerated IVD tissues, and GDF-5 might have an inhibition effect on degenerated lumbar IVD, suggesting that gene therapy may be a useful approach in producing physiological effects during early- and late-phase of lumbar IDD.

Different Sutures in the Surgical Treatment of Acute Closed Achilles Tendon Rupture.

The aim was to compare the postoperative efficacy of the PDS II and Ethibond W4843 sutures in fresh, closed Achilles tendon rupture. With methods of random grouping (level of evidence II b), a total of 128 patients with fresh Achilles tendon rupture were operated on with PDS II or Ethibond W4843 suture. Postoperative objective examination and the American Orthopaedic Foot & Ankle Society (AOFAS) scoring system were used for the evaluation. Group A underwent 12-39 months of follow-up, for an average of 22 months. Group B underwent 12-37 months of follow-up, for an average of 23 months. The postoperative AOFAS score of group A within 3 months was 93 ± 9.6 points. One case exhibited re-rupture, five cases exhibited incision infection, one case manifested deep infection, and seven cases exhibited Achilles tendon adhesion. The postoperative AOFAS score of group B within 3 months was 97 ± 7.8 points. Eleven cases had incision infection, and 13 cases manifested Achilles tendon adhesion. Minimal differences were observed in the incision infection, re-rupture rate, and Achilles tendon adhesion in the study of the PDS II and Ethibond W4843 sutures. But, based on the AOFAS score and pain score, the Ethibond suture performed better.