Protopine protects chondrocytes from undergoing ferroptosis by activating Nrf2 pathway.

Osteoarthritis is a highly prevalent joint disease; however, effective treatments are lacking. Protopine (PTP) is an isoquinoline alkaloid with potent anti-inflammatory and antioxidant properties; however, it has not been studied in osteoarthritis. This study aimed to investigate whether PTP can effectively protect chondrocytes from ferroptosis. Primary mouse chondrocytes were treated with tert-butyl hydroperoxide (TBHP) to simulate oxidative stress in an in vitro model of osteoarthritis. Two concentrations of PTP (10 and 20 µg/mL) were validated for in vitro experiments. Cellular inflammation and metabolism were detected using RT-qPCR and western blotting (WB). Ferroptosis was assessed via WB, qPCR, reactive oxygen species (ROS) levels, lipid ROS, and immunofluorescence staining. In vitro, PTP significantly ameliorated chondrocyte inflammation and cytolytic metabolism and significantly suppressed chondrocyte ferroptosis through the activation of the Nrf2 pathway. The anterior cruciate ligament transection (ACLT) mouse model was used to validate the in vivo effects of PTP. The joint cartilage was assessed using the Osteoarthritis Research Society International (OARSI) score, Safranin O staining, and immunohistochemistry. The intra-articular administration of PTP alleviated cartilage inflammation and ferroptosis, as evidenced by the expression of MMP3, MMP13, COL2A1, GPX4, and Nrf2. Overall, we find that PTP exerted anti-ferroptosis and anti-inflammatory effects on chondrocytes to protect the articular cartilage.

Malposition is main cause of failure of Oxford mobile-bearing medial unicompartmental knee arthroplasty.

Aims: Unicompartmental knee arthroplasty (UKA) is the preferred treatment for anterior medial knee osteoarthritis (OA) owing to the rapid postoperative recovery. However, the risk factors for UKA failure remain controversial. Methods: The clinical data of Oxford mobile-bearing UKAs performed between 2011 and 2017 with a minimum follow-up of five years were retrospectively analyzed. Demographic, surgical, and follow-up data were collected. The Cox proportional hazards model was used to identify the risk factors that contribute to UKA failure. Kaplan-Meier survival was used to compare the effect of the prosthesis position on UKA survival. Results: A total of 407 patients who underwent UKA were included in the study. The mean age of patients was 61.8 years, and the mean follow-up period of the patients was 91.7 months. The mean Knee Society Score (KSS) preoperatively and at the last follow-up were 64.2 and 89.7, respectively (p = 0.001). Overall, 28 patients (6.9%) with UKA underwent revision due to prosthesis loosening (16 patients), dislocation (eight patients), and persistent pain (four patients). Cox proportional hazards model analysis identified malposition of the prostheses as a high-risk factor for UKA failure (p = 0.007). Kaplan-Meier analysis revealed that the five-year survival rate of the group with malposition was 85.1%, which was significantly lower than that of the group with normal position (96.2%; p < 0.001). Conclusion: UKA constitutes an effective method for treating anteromedial knee OA, with an excellent five-year survival rate. Aseptic loosening caused by prosthesis malposition was identified as the main cause of UKA failure. Surgeons should pay close attention to prevent the potential occurrence of this problem.

Student-Driven Course-Based Undergraduate Research Experience (CUREs) Projects in Identifying Vaginal Microorganism Species Communities to Promote Scientific Literacy Skills.

Objectives: We aim to build a students' own engagement in original microbiological course-based undergraduate research experience (CUREs) model served two research and teaching scientific purposes including students' scientific literacy skills and instructors' role, which could further be applied as contribution to broader scientific knowledge and conduct novel research in their future research experience and careers. Methods: We describe a student-driven CUREs model on the microorganism species in female vaginal using general bacterial culture techniques and high-throughput 16S rRNA gene amplicon sequencing to enable students to center experimental research method under the direction of instructors. A total of 8 undergraduate students and 5 instructors from Shanghai Jiao Tong University School of Medicine participated in the project. The CUREs were divided in four operating scopes: project planning, implementation, summarizing and feedback phases. Instructors help students to develop learning research goals. Results: This project helped students to gain "hard skills" experiences in scientific theoretical research process and technical practices. Students reached the conclusion that Lactobacillus species dominated the primary vaginal microbiota in reproductive-age women, 16S rRNA sequencing is a method widely applied for microbiology detection. CUREs also increased students' engagement in scientific experiments and promote 3 learning goals in "soft skills": (1) Develop students' self-study and efficacy ability, expression capability and professional research communication skills; (2) Strengthen students' motivation and ownership in science research, overcoming failure, benefitting persistence and patience, building professional science identity, competence, and confidence in collaboration, implement spirit of rigorous and carefulness; (3) Obtain authorship, independent and logical thinking capability, summarizing ability and confidence enhancement. Instructors proposed guiding research question for the students and determine evidence in achieving pedagogical goals in CUREs. Conclusions: Our microbiological CUREs project served two scientific purposes: research and teaching, which increase students' engagement in promoting learning gains in scientific research skills, ownership, identity development, and spirit of motivation, self-efficacy, persistence, collaboration, communication, as well as opportunities to make relevant scientific discoveries. These abilities equipped them with essential foundation for the subsequent collaborative experiments and future scientific study.

Nangibotide attenuates osteoarthritis by inhibiting osteoblast apoptosis and TGF-ß activity in subchondral bone.

Osteoarthritis (OA) is a chronic joint disorder that causes cartilage degradation and subchondral bone abnormalities. Nangibotide, also known as LR12, is a dodecapeptide with considerable anti-inflammatory properties, but its significance in OA is uncertain. The aim of the study was to determine whether nangibotide could attenuate the progression of OA, and elucidate the underlying mechanism. In vitro experiments showed that nangibotide strongly inhibited TNF-α-induced osteogenic reduction, significantly enhanced osteoblast proliferation and prevented apoptosis in MC3T3-E1 cells. Male C57BL/6 J mice aged 2 months were randomly allocated to three groups: sham, ACLT, and ACLT with nangibotide therapy. Nangibotide suppressed ACLT-induced cartilage degradation and MMP-13 expression. MicroCT analysis revealed that nangibotide attenuated in vivo subchondral bone loss induced by ACLT. Histomorphometry results showed that nangibotide attenuated ACLT-induced osteoblast inhibition; TUNEL assays and immunohistochemical staining of cleaved-caspase3 further confirmed the in vivo anti-apoptotic effect of nangibotide on osteoblasts. Furthermore, we found that nangibotide exerted protective effects by suppressing TGF-ß signaling mediated by Smad2/3 to restore coupled bone remodeling in the subchondral bone. In conclusion, the findings suggest that nangibotide might exert a protective effect on the bone-cartilage unit and maybe an alternative treatment option for OA.

Toddalolactone protects against osteoarthritis by ameliorating chondrocyte inflammation and suppressing osteoclastogenesis.

BACKGROUND: Osteoarthritis (OA) is widely recognized as the most common chronic joint disease accompanied by progressive cartilage and subchondral bone damage. Toddalolactone (TOD), a natural compound extracted from Toddalia asiatica (L.) Lam., has been widely used in the treatment of stroke, rheumatoid arthritis, and oedema. Nevertheless, what TOD acts as in the pathogenesis and progression of OA hasn't been reported. In this investigation, we have aimed to determine how TOD affects OA in vitro and in vivo. METHODS: LPS (10 µg/ml) and IL-1ß (10 ng/ml) were employed to induce chondrocyte inflammation or RANKL to induce osteoclast differentiation in bone marrow derived macrophages (BMMs). The effects of TOD on chondrocyte inflammation and osteoclast differentiation were evaluated. Anterior cruciate ligament transection (ACLT) was performed to develop an OA animal model and study the effects of TOD. RESULTS: We found that TOD inhibited the expression of inflammatory and catabolic mediators (IL-6, IL-8, TNF-α, MMP2, MMP9, and MMP13) in inflammatory chondrocytes in vitro. Furthermore, TOD was proven to inhibit RANKL-induced-osteoclastogenesis and inhibit the expression of osteoclast marker genes. Our data also confirmed that TOD suppressed the destruction of articular cartilage and osteoclastogenesis via inhibiting the activation of NF-κB and MAPK signalling pathways. In the ACLT mouse model, we found that TOD attenuated cartilage erosion and inhibited bone resorption. CONCLUSIONS: These results showed that TOD can be adopted as a potential therapeutic agent for OA.

CoCrMo-Nanoparticles induced peri-implant osteolysis by promoting osteoblast ferroptosis via regulating Nrf2-ARE signalling pathway.

OBJECTIVES: Aseptic loosening (AL) is the most common reason of total hip arthroplasty (THA) failure and revision surgery. Osteolysis, caused by wear particles released from implant surfaces, has a vital role in AL. Although previous studies suggest that wear particles always lead to osteoblast programmed death in the process of AL, the specific mechanism remains incompletely understood and osteoblast ferroptosis maybe a new mechanism of AL. MATERIALS AND METHODS: CoCrMo nanoparticles (CoNPs) were prepared to investigate the influence of ferroptosis in osteoblasts and calvaria resorption animal models. Periprosthetic osteolytic bone tissue was collected from patients who underwent AL after THA to verify osteoblast ferroptosis. RESULTS: Our study demonstrated that CoNPs induced significant ferroptosis in osteoblasts and particles induced osteolysis (PIO) animal models. Blocking ferroptosis with specific inhibitor Ferrostatin-1 dramatically reduced particle-induced ferroptosis in vitro. Moreover, in osteoblasts, CoNPs significantly downregulated the expression of Nrf2 (nuclear factor erythroid 2-related factor 2), a core element in the antioxidant response. The overexpression of Nrf2 by siKeap1 or Nrf2 activator Oltipraz obviously upregulated antioxidant response elements (AREs) and suppressed ferroptosis in osteoblasts. Furthermore, in PIO animal models, the combined utilization of Ferrostatin-1 and Oltipraz dramatically ameliorated ferroptosis and the severity of osteolysis. CONCLUSIONS: These results indicate that CoNPs promote osteoblast ferroptosis by regulating the Nrf2-ARE signalling pathway, which suggests a new mechanism underlying PIO and represents a potential therapeutic approach for AL.

Bikini Incision Increases the Incidence of Lateral Femoral Cutaneous Nerve Injury in Direct Anterior Approach Hip Arthroplasty: A Prospective Ultrasonic, Electrophysiological, and Clinical Study.

BACKGROUND: Lateral femoral cutaneous nerve (LFCN) injury has been widely reported as one of the most common complications of direct anterior approach (DAA) hip arthroplasty. Bikini incision is considered to increase the incidence of this complication. METHODS: A prospective randomized study was conducted after including ninety-nine bikini and ninety-six longitudinal incision DAA cases from May to November 2020. The occurrence of LFCN was examined using ultrasound before and after surgery. The recovery of injury symptoms was evaluated by continuous clinical follow-up until six months, and the patients were treated with mecobalamin and/or celecoxib. Sensory conduction velocity and sensory action potential amplitude of the LFCN were measured after surgery in symptomatic patients. RESULTS: Eighty five (43.6%), sixty seven (34.4%), and forty three (22.0%) cases of LFCN were of the anterior trunk, posterior trunk, and fan types, respectively, before surgery. All one hundred ninety five patients completed the follow-up period. Fifty-seven patients had symptoms of LFCN injury, including thirty six and twenty one patients in the bikini group and longitudinal group, respectively, with significantly different incidence rates (36.4% and 21.9%, respectively; P < .05). Of these, thirty two (56.1%), thirteen (22.8%), and twelve (21.1%) cases were of the anterior trunk, posterior trunk, and fan types, respectively. Sensory conduction velocity and sensory action potential amplitude significantly decreased after surgery in both groups (P < .05). Seventeen cases showed reduction of symptoms within three months. Forty six cases showed self-recovery within six months and eleven cases showed persistent symptoms at the final follow-up. CONCLUSION: Bikini incision DAA hip arthroplasty may increase the incidence of LFCN injury, and the anterior trunk distribution type is most likely to be affected. (Clinical Trial Registration Number: CHICTR2000035107).

METTL3 involves the progression of osteoarthritis probably by affecting ECM degradation and regulating the inflammatory response.

We aimed to identify RNA N6-methyladenosine methylation associated genes in osteoarthritis (OA), and to explore possible regulatory mechanisms of these RNA methylation associated genes. Bioinformatics analyses, including differential expression analysis, functional enrichment analysis, verification analysis, and box plot analysis, were conducted based on different datasets from OA and non-OA patients. Gene expression at mRNA and protein levels was determined by quantitative reverse transcription PCR, western blot and immunofluorescence. Interleukin 1ß (IL-1ß)-treated SW1353 cells was used as cell model. Lentiviral vector was used for over-expression METTL3 in vitro. CCK-8 assay kit was used to determine cell viability and inflammatory cytokines (IL-1α, IL-6, IL-8, IL-10 and TNF-α) was detected using ELISA kits. Bioinformatics analysis showed that METTL3 expression was decreased in OA group, which was confirmed in clinical samples. Expression of METTL3 was also reduced in IL-1ß-treated cells. Levels of inflammatory cytokines were obviously reduced in the METTL3 overexpression group, while IL-1ß treatment reversed such decrease caused by METTL3 overexpression (p < 0.05). Both METTL3 overexpression and IL-1ß treatment promoted expression of p65 protein and p-ERK (p < 0.01). Additionally, increased expression of MMP1 and MMP3, and decreased expression of MMP13, TIMP-1, and TIMP-2 at both mRNA and protein levels were observed in the METTL3 overexpression group when compared with the control group (p < 0.01). Expression of m6A methylation gene METTL3 was reduced in OA. METTL3 is involved in OA probably by regulating the inflammatory response. METTL3 overexpression may affect extracellular matrix degradation in OA by adjusting the balance between TIMPs and MMPs.

Cartilage-targeting peptide-modified dual-drug delivery nanoplatform with NIR laser response for osteoarthritis therapy.

Cartilage-targeting delivery of therapeutic agents is still an effective strategy for osteoarthritis (OA) therapy. Recently, scavenging for reactive oxygen species (ROS) and activating autophagy have been increasingly reported to treat OA effectively. In this study, we designed, for the first time, a dual-drug delivery system based on metal organic framework (MOF)-decorated mesoporous polydopamine (MPDA) which composed of rapamycin (Rap) loaded into the mesopores and bilirubin (Br) loaded onto the shell of MOF. The collagen II-targeting peptide (WYRGRL) was then conjugated on the surface of above nanocarrier to develop a cartilage-targeting dual-drug delivery nanoplatform (RB@MPMW). Our results indicated the sequential release of two agents from RB@MPMW could be achieved via near-infrared (NIR) laser irritation. Briefly, the rapid release of Br from the MOF shell exhibited excellent ROS scavenging ability and anti-apoptosis effects, however responsively reduced autophagy activity, to a certain extent. Meanwhile, following the NIR irradiation, Rap was rapidly released from MPDA core and further enhanced autophagy activation and chondrocyte protection. RB@MPMW continuously phosphorylated AMPK and further rescued mitochondrial energy metabolism of chondrocytes following IL-1ß stimulation via activating SIRT1-PGC-1α signaling pathway. Additionally, the cartilage-targeting property of peptide-modified nanocarrier could be monitored via Magnetic Resonance (MR) and IVIS imaging. More significantly, RB@MPMW effectively delayed cartilage degeneration in ACLT rat model. Overall, our findings indicated that the as-prepared dual-drug delivery nanoplatform exerted potent anti-inflammation and anti-apoptotic effects, rescued energy metabolism of chondrocytes in vitro and prevented cartilage degeneration in vivo, which thereby showed positive performance for OA therapy.

Esculentoside A protects against osteoarthritis by ameliorating inflammation and repressing osteoclastogenesis.

Osteoarthritis is a relatively common disorder of articular deterioration related to cartilage damage, subchondral bone remodelling, inflammation and metabolism. Agents that can inhibit cartilage degradation and osteoclastogenesis are required for the prevention and treatment of osteoarthritis. Esculentoside A, the highest concentration triterpene saponin isolated from the root of Phytolacca esculenta, has commonly been used for the treatment of chronic bronchitis. However, the role esculentoside A plays in ameliorating osteoarthritis has not been reported. We found that esculentoside A suppresses the expression of IL-1ß-induced inflammatory and metabolic factors (IL-6, IL-8, TNF-α, MMP2, MMP3 and MMP13). In addition, esculentoside A restrains osteoclast formation by inhibiting the marker gene expression of NFATc1 and c-Fos. Our results indicate that esculentoside A markedly suppresses IL-1ß-induced NF-κB and MAPK signalling pathway activation in chondrocytes, and inhibits RANKL-induced osteoclast precursor generation. Finally, treatment with esculentoside A inhibits the progressive cartilage degeneration and osteoclastogenesis in osteoarthritis mouse models. In summary, these results demonstrate that esculentoside A could be a latent therapeutic reagent for the treatment of osteoarthritis.

LDC000067 suppresses RANKL-induced osteoclastogenesis in vitro and prevents LPS-induced osteolysis in vivo.

Bone homeostasis requires a dynamic balance between osteogenesis and osteoclastogenesis, and osteolytic disorders are mainly attributed to aberrant osteoclastogenesis and bone resorption. Accumulating evidence has demonstrated that cyclin-dependent kinase 9 (CDK9) regulates some inflammatory diseases without affecting the cell cycle. Whether the specific inhibitor of CDK9, LDC000067 (abbreviated as LDC067), helps to prevent from osteolytic disorders has not been fully elucidated. Interestingly, this study demonstrated that LDC067 inhibited receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclastogenesis and bone resorption in vitro, and suppressed the expression of osteoclast-related marker genes such as cathepsin K (CTSK), tartrate-resistant acid phosphatase (TRAP), dendrite cell-specific transmembrane protein (DC-STAMP), V-ATPase D2, calcitonin receptor (CTR) and nuclear factor of activated T cells cytoplasmic 1 (NFATc1). The bone protective effects of LDC067 can be partly explained by its suppression of nuclear factor-kappa B (NF-κB)-mediated NFATc1 activation via AKT signalling pathway. In keeping with the results obtained in vitro, inhibition of CDK9 with LDC067 was observed to delay subchondral osteolysis and substantially ameliorate LPS-induced osteolysis in murine calvaria. Collectively, these results highlight the positive effects of LDC067 in preventing osteolytic disorders and indicate that this CDK9 inhibitor may a promising therapeutic agent.

CDK9 attenuation exerts protective effects on catabolism and hypertrophy in chondrocytes and ameliorates osteoarthritis development.

Osteoarthritis (OA) is generally considered to be characterized by progressive articular cartilage destruction. Increasing evidence demonstrates that CDK9, which is a member of cyclin-dependent kinase family, plays a significant role in the regulation of acute and chronic inflammatory diseases. IL-1ß, a major proinflammatory cytokine, was used to establish a model of OA in vitro after stimulating chondrocytes. We found that CDK9 was highly expressed in in vitro and in vivo models of inflammation. The role of LDC000067 (abbreviated as LDC067), a specific inhibitor of CDK9, in protecting articular cartilage from immune response has not been fully clarified. Intriguingly, in this study, we demonstrated that LDC067 prevented IL-1ß-induced production of metalloproteinases (MMPs) and inflammatory cytokines, including MMP3, MMP9, MMP13, IL-6, IL-8 and TNF-ɑ. Furthermore, we revealed that LDC067 inhibited IL-1ß-induced NF-κB signaling pathway activation in chondrocytes. The inhibition of CDK9 could also delay cartilage degeneration in an anterior cruciate ligament transection (ACLT) mouse model in vivo. Taken together, these results highlighted the significance of this CDK9 inhibitor in preventing cartilage destruction and indicated that LDC067 might serve as a potential therapeutic agent for OA.

Anlotinib, a novel small molecular tyrosine kinase inhibitor, suppresses growth and metastasis via dual blockade of VEGFR2 and MET in osteosarcoma.

Osteosarcoma is the most common primary malignant bone tumor in children and adolescents, with highly aggressive behavior and early systemic metastasis. The survival rates for osteosarcoma remain unchanged over the past two decades. Studies aiming to find new or alternative therapies for patients with refractory osteosarcoma are urgently needed. Anlotinib, a novel multi-targeted tyrosine kinase inhibitor (TKI), has exhibited encouraging clinical activity in NSLCC and soft tissue sarcoma, whereas its effect on osteosarcoma has not been studied. In our study, we investigated the anti-tumor activity and underlying mechanism of anlotinib in osteosarcoma. Various in vitro and in vivo models of human osteosarcoma were used to determine the anti-proliferative, anti-angiogenesis and anti-metastasis efficacy of anlotinib. Our results showed that anlotinib suppressed tumor growth and increased the chemo-sensitivity of osteosarcoma. In addition, anlotinib inhibited migration and invasion in osteosarcoma cells. Furthermore, in order to explore the anti-tumor mechanism of anlotinib, phospho-RTK antibody arrays were performed. These analyses confirmed that anlotinib suppressed the phosphorylation of MET, VEGFR2 and the downstream signaling pathway activation. Moreover, we demonstrated that anlotinib blocked hepatocyte growth factor (HGF)-induced cell migration, invasion and VEGF-induced angiogenesis. Notably, a 143B-Luc orthotopic osteosarcoma model further showed that anlotinib significantly inhibited growth and lung metastasis of implanted tumor cells. Our preclinical work indicates that anlotinib acts as a novel inhibitor of VEGFR2 and MET that blocks tumorigenesis in osteosarcoma, which could be translated into future clinical trials.

Effect of Celecoxib on Surgical Site Inflammation after Total Knee Arthroplasty: A Randomized Controlled Study.

OBJECTIVE: To evaluate the anti-inflammatory effectiveness of celecoxib and its effect on the rehabilitation of joint function after total knee arthroplasty. METHODS: 72 patients presented between 2016 and 2017 and were divided into two groups. The experimental group was given 200 mg celecoxib twice daily with tramadol hydrochloride 50 mg twice daily (as required); the control group was given tramadol hydrochloride 50 mg twice daily for 6 weeks from the first day after total knee arthroplasty. Skin temperature around the knee was measured 1 day before surgery, on postoperative days 1 and 3, and at weeks 1, 2, and 6. Inflammatory markers (white blood cell count, C-reactive protein, erythrocyte sedimentation rate, and interleukin-6) were measured preoperatively, on postoperative day 3, and at weeks 1 and 6. Knee Society Score was recorded preoperatively and at postoperative weeks 1, 2, and 6. RESULTS: Except for preoperative skin temperature, the recorded skin temperatures of the experimental group were significantly different compared to those of the control group (p = 0.001, 0.024, 0.030, 0.041, 0.047, respectively). Levels of C-reactive protein were significantly different at the 1st and the 6th week after surgery, differing by 19.3 ± 4.64 mg/L (p < 0.001) and 2.6 ± 0.92 mg/L (p = 0.006). Levels of interleukin-6 showed a significant difference of 6.61 ± 2.36 pg/mL (p = 0.007) at the 1st week after surgery. Until the 6th week after surgery, the erythrocyte sedimentation rate in the experimental group and the control group differed by 17 ± 4.6 mm/h (p = 0.001). CONCLUSIONS: Celecoxib has a significant inhibitory effect on postoperative aseptic inflammation.

Oxymatrine exerts protective effects on osteoarthritis via modulating chondrocyte homoeostasis and suppressing osteoclastogenesis.

Osteoarthritis (OA) is a common degenerative disease characterized by the progressive destruction both articular cartilage and the subchondral bone. The agents that can effectively suppress chondrocyte degradation and subchondral bone loss are crucial for the prevention and treatment of OA. Oxymatrine (OMT) is a natural compound with anti-inflammatory and antitumour properties. We found that OMT exhibited a strong inhibitory effect on LPS-induced chondrocyte inflammation and catabolism. To further support our results, fresh human cartilage explants were treated with LPS to establish an ex vivo degradation model, and the results revealed that OMT inhibited the catabolic events of LPS-stimulated human cartilage and substantially attenuated the degradation of articular cartilage ex vivo. As subchondral bone remodelling is involved in OA progression, and osteoclasts are a unique cell type in bone resorption, we investigated the effects of OMT on osteoclastogenesis, and the results demonstrated that OMT suppresses RANKL-induced osteoclastogenesis by suppressing the RANKL-induced NFATc1 and c-fos signalling pathway in vitro. Further, we found that the anti-inflammatory and anti-osteoclastic effects of oxymatrine are mediated via the inhibition of the NF-κB and MAPK pathways. In animal studies, OMT suppressed the ACLT-induced cartilage degradation, and TUNEL assays further confirmed the protective effect of OMT on chondrocyte apoptosis. MicroCT analysis revealed that OMT had an attenuating effect on ACLT-induced subchondral bone loss in vivo. Taken together, these results show that OMT interferes with the vicious cycle associated with OA and may be a potential therapeutic agent for abnormal subchondral bone loss and cartilage degradation in osteoarthritis.

BRD4 has dual effects on the HMGB1 and NF-κB signalling pathways and is a potential therapeutic target for osteoarthritis.

Osteoarthritis (OA) has traditionally been defined as a non-inflammatory disease. Recently, many studies have demonstrated that OA also has an inflammatory component. BRD4, a member of the Bromodomain and Extra-Terminal Domain family, has emerged as an important regulator of some chronic inflammatory diseases. JQ1, an antagonist of BRD4, modulates transcription of several genes. Our study demonstrated that BRD4 is up-regulated in articular cartilage of OA. BRD4 inhibition attenuated the inflammation and catabolism of chondrocytes and suppressed NF-κB signalling pathway activation. In addition, BRD4 inhibition abolished the transcriptional activity of High Mobility Group Protein B1 (HMGB1). We identified HMGB1 as a direct target of BRD4. Genetic and pharmacological inhibition of BRD4 suppressed IL-1ß-induced expression and translocation of HMGB1. Chromatin immunoprecipitation (ChIP) showed the enrichment of BRD4 around the HMGB1 upstream non-promoter region, which diminished with JQ1 treatment. Finally, haematoxylin & eosin and Safranin o/Fast Green staining demonstrated that JQ1 attenuates cartilage destruction in mice with anterior cruciate ligament transection without significant toxic effects. These studies highlighted the importance of BRD4 in the chronic inflammatory reactions of OA, which, as far as we know, was the first report of this finding, and suggested that BRD4 might be a novel potential therapeutic target for the treatment of OA.

[Comparative study on differences in acetabular position during total hip arthroplasty between by direct anterior approach and by posterolateral approach].

Objective: To compare the differences in acetabular position during total hip arthroplasty (THA) between by direct anterior approach and by posterolateral approach. Methods: Between December 2008 and December 2015, 102 patients undergoing THA were included in the study. THA was performed by anterior approach in 51 cases (anterior group) and by posterolateral approach in 51 cases (posterolateral group). There was no significant difference in gender, age, body mass index, side, and cause of illness between 2 groups ( P>0.05), with comparability. The acetabular abduction angle and anteversion angel were measured on the X-ray film at 1 day after operation to evaluate whether the acetabular prosthesis was displaced in the safe zone. Results: The acetabular abduction angle was (42.28±5.77)° in the anterior group and was (43.93±7.44)° in the posterolateral group, showing no significant difference ( t=1.30, P=0.19). The acetabular anteversion angle was (21.14±5.17)° in the anterior group and was (21.05±4.10)° in the posterolateral group, showing no significant difference ( t=0.05, P=0.96). The ratio in the target safe zone of the acetabular abduction angle in the anterior group and the posterolateral group were 88.2% (45/51) and 84.3% (43/51) respectively, showing no significant difference ( χ2=0.33, P=0.56). The ratio in the target safe zone of the acetabular anteversion was 80.4% (41/51) in the anterior group and was 82.4% (42/51) in the posterolateral group, showing no significant difference between 2 groups ( χ2=0.06, P=0.79). The ratio in the target safe zone of both the abduction and anteversion angel was 70.6% (36/51) in the anterior group and was 68.6% (35/51) in the posterolateral group, showing no significant difference ( χ2=0.05, P=0.82). Conclusion: There is no differences in the acetabulum position during THA between by direct anterior approach and posterolateral approach.

[Mid-term effectiveness of total hip arthroplasty by direct anterior approach].

Objective: To retrospectively compare the mid-term effectiveness between by direct anterior approach (DAA) and by posterolateral approach in total hip arthroplasty (THA). Methods: Between January 2009 and December 2010, 110 patients (110 hips) treated with THA and followed up more than 5 years were chosen in the study. THA was performed on 55 patients by DAA (DAA group), and on 55 patients by posterolateral approach (PL group). There was no significant difference in gender, age, body mass index, types of hip joint disease, and preoperative Harris score between 2 groups ( P>0.05). The operation time, amount of bleeding, length of hospital stay, postoperative complications, and the Harris scores were recorded and compared. Results: There was no significant difference in operation time and length of hospital stay between 2 groups ( t=0.145， P=0.876; t=1.305, P=0.093). The amount of bleeding was significantly less in DAA group than in PL group ( t=2.314, P=0.032). All patients were followed up 5-7 years (mean, 5.97 years). Complications happened in 5 cases (9.1%) of DAA group and in 3 cases (5.5%) of PL group, and there was no significant difference in the incidence of complications between 2 groups ( χ2=0.539， P=0.463). There was significant difference in Harris scores at 6 months after operation between 2 groups ( t=2.296, P=0.014), but no significant difference was found in Harris score at 1 year and 5 years between 2 groups ( t=1.375, P=0.130; t=0.905, P=0.087). Further analysis, at 6 months after operation, the joint function score in DAA group was significantly higher than that in PL group ( t=1.087, P=0.034), while there was no significant difference in the pain score and range of motion score between 2 groups ( t=1.872, P=0.760; t=1.059, P=0.091). Conclusion: THA by DAA has the advantages of less bleeding and faster recovery. The short-term effectiveness is superior to the THA by traditional posterolateral approach, but there is no obvious advantage in the mid-term effectiveness.

[Expression of Sclerostin in medial and lateral subchondral bone of the varus osteoarthritic knee plateau].

Objective: To study the expression difference of Sclerostin in the medial and lateral subchondral bone of the varus osteoarthritic knee plateau. Methods: The tibial plateau was obtained from 20 patients with varus knee osteoarthritis receiving total knee arthroplasty from March to October 2015. There were 8 males and 12 females with an average age of 67.8 years (range, 61-78 years). The mean course of osteoarthritis was 3.2 years (range, 2-5 years). Before operation, the varus angle was 12.0-25.5° (mean, 17.6°) on the X-ray film. Five cases were rated as grade III and 15 cases as grade IV according to Kellgren-Lawrance classification. Micro-CT scan was performed on the medial and lateral subchondral bone to compare the changes of bone structure; bone volume/total volume (BV/TV), trabecular number (Tb.N), trabecular thickness (Tb.Th), structure model index (SMI), and the trabecular separation (Tb.Sp) were measured. Immunohistochemistry and real-time fluorescent quantitative PCR were used to test the expressions of Sclerostin protein and sost gene. Results: Micro-CT showed that BV/TV, Tb.N, and Tb.Th significantly increased in the medial subchondral bone when compared with the lateral part ( P<0.05), but SMI and Tb.Sp significantly reduced ( P<0.05). Real-time fluorescent quantitative PCR detection showed that sost gene expression level in the medial subchondral bone (1.000) was significantly lower than that in the lateral part (4.157±2.790) ( t=2.371, P=0.040). The percentage of Sclerostin positive cells in the lateral subchondral bone (52.00%±0.19%) was significantly higher than that in the medial subchondral bone (7.20%±0.04%) ( t=5.094, P=0.005). Conclusion: Sclerostin plays an important role in the subchondral bone remodeling of the varus osteoarthritic knee. And the low expression of Sclerostin may be an important factor to promote bone remodeling and aggravate knee deformity.

The Influence of Body Mass Index and Hip Anatomy on Direct Anterior Approach Total Hip Replacement.

OBJECTIVE: To investigate the influence of body mass index (BMI) and hip anatomy on direct anterior approach (DAA) total hip replacement. SUBJECTS AND METHODS: The study is a retrospective analysis of 124 cases of DAA total hip replacement from 2009 to 2012. The BMI, the ratio of the greater trochanter (GT) and anterior superior iliac spine (ASIS) bilaterally (GT/ASIS), and the vertical distance between the ASIS and GT (AGVD) were obtained from medical records. All cases were categorized into three groups (43, 49, and 32 cases in each group, respectively) based on BMI (BMI <18.5, BMI 18.5-25, and BMI >25) or divided into two groups based on GT/ASIS (≤1.17 or >1.17) or AGVD (≤86 or >86 mm). Operating time, intraoperative bleeding, and surgical complications were compared between different groups. RESULTS: A longer average operating time, more intraoperative bleeding, and a higher rate of complications were observed in the group with the highest BMI. The complications included a case of intraoperative femur fracture, a wound hematoma, and a lateral femoral cutaneous nerve injury. The group with higher GT/ASIS had a shorter average operating time, less bleeding, and a lower complication rate than the group with lower GT/ASIS. Moreover, the group with higher AGVD showed a shorter average operating time, less bleeding, and a lower complication rate compared with the group with lower AGVD. CONCLUSION: Our study suggests that lower BMI and larger GT/ASIS and AGVD are associated with a shorter operating time, less bleeding, and a lower complication rate in DAA total hip replacement. These findings are valuable for clinicians to make the appropriate choice of surgery types for different individuals.