Artesunate ameliorates osteoarthritis cartilage damage by updating MTA1 expression and promoting the transcriptional activation of LXA4 to suppress the JAK2/STAT3 signaling pathway.

The objective of this study was to discuss the mechanism of artesunate (ART) in improving cartilage damage in osteoarthritis (OA) by regulating the expression levels of metastatic tumor antigen 1 (MTA1), lipoxin A4 (LXA4) and the downstream JAK2/STAT3 signaling pathway. The OA model in vitro was constructed by stimulating chondrocytes for 24 h with 10 ng/mL interleukin (IL)-1ß, and cell proliferation and apoptosis, expression levels of Aggrecan, MTA1, LXA4, MMP3, MMP13 and Collagen II, and inflammatory cytokines in the culture supernatants were examined. Histopathological changes, inflammatory response and chondrocyte apoptosis of the cartilage tissues of OA mice were performed. In vitro cell experiments, ART enhanced cell proliferation capacity, accompanied by decreased apoptosis rate, decreased expression of MMP-3 and MMP-13, elevated expression of Collagen II and Aggrecan, as well as reduced levels of IL-6 and TNF-α in the cell supernatant. ART also ameliorated IL-1ß-induced chondrocyte damage by upregulating MTA1. The LXA4 promoter region had two potential binding sites for MTA1. There was a positive correlation between MTA1 and LXA4. MTA1 enhanced the expression of LXA4 through transcription and blocked the activation of the JAK2/STAT3 signaling pathway. In vivo animal model experiments further showed that ART treatment alleviated cartilage tissue damage in OA model mice by upregulating MTA1. Our study demonstrates that ART improves the cartilage damage of OA by upregulating MTA1 expression and promoting the transcriptional activation of LXA4, and further blocking the JAK2/STAT3 signaling pathway.

Melatonin promotes the restoration of bone defects via enhancement of miR-335-5p combined with inhibition of TNFα/NF-κB signaling.

Accelerating the repair of a bone defect is crucial clinically due to the increased prevalence of trauma, tumor, and infections in bone. Studies have found that excess acute and chronic inflammation attenuate osteogenic differentiation of BMSCs (bone marrow mesenchymal stem cells). Moreover, TNF-α and NF-κB could inhibit osteoblasts differentiation of BMSCs and promote osteoclastogenesis via multiple mechanisms, such as increasing osteoclast precursor cells and acting synergistically with cell cytokines. However, melatonin could inhibit the expression of TNFα/NF-κB and promote bone formation by activating the Wnt/ß-catenin signaling pathway. However, there has been no evidence regarding the effect of melatonin on TNFα/NF-κB-inhibited osteoblastogenesis and bone formation. This study aimed to investigate the role of melatonin on TNFα/NF-κB-inhibited osteoblastogenesis and bone formation. Micro-CT, high-throughput screening, overexpression, and other methods were used, and we found that the number of osteoblasts was elevated with melatonin treatment. Additionally, TNFα/NF-κB signaling was inhibited, while miR-335-5p expression increased markedly following treatment with melatonin. Furthermore, miR-335-5p negatively regulated TNFα/NF-κB signaling, while miR-335-5p inhibitor ameliorated the effects of melatonin on TNFα/NF-κB. In conclusion, melatonin facilitates osteogenesis in bone defect healing by enhancing miR-335-5p expression and inhibiting the TNFα/NF-κB pathway.

The Efficacy and Safety of Bionic Tiger Bone Powder for the Treatment of Knee Osteoarthritis in Early Stage: A Randomized, Double-Blind, Placebo-Controlled, Multicenter Clinical Trial.

Objective: This study evaluated the efficacy and safety of bionic tiger bone powder (Jintiange) in comparison to placebo in treating knee osteoarthritis osteoporosis. Methods: A total of 248 patients were randomly allocated to a Jintiange group or a placebo group, undergoing 48 weeks of double-blind treatment. The Lequesne index, clinical symptoms, safety index (adverse events), and Patient's Global Impression of Change score were recorded at pre-determined time intervals. All P values ≤ .05 were deemed statistically significant. Results: Both groups showed a decreasing trend in the Lequesne index, with the Jintiange group's reduction significantly larger from the 12th week (P ≤ .01). Similarly, the effective rate of Lequesne score in the Jintiange group was significantly higher (P < .001). After 48 weeks, clinical symptom score differences between the Jintiange group (2.46 ± 1.74) and the placebo group (1.51 ± 1.73) were statistically significant (P < .05), as were differences in the Patient's Global Impression of Change score (P < .05). Adverse drug reactions were minimal with no significant difference between the groups (P > .05). Conclusion: Jintiange demonstrated superior efficacy over placebo in treating knee osteoporosis, with comparable safety profiles. Findings warrant further comprehensive real-world studies.

Melatonin increases bone mass in normal, perimenopausal, and postmenopausal osteoporotic rats via the promotion of osteogenesis.

BACKGROUND: Osteoporosis is a disease threatening the health of millions of individuals. Melatonin is found to be a potential anti-osteoporosis drug. However, whether melatonin plays a role against osteoporosis at different stages of the menopause and the underlying mechanisms are unknown. METHODS: Ovariectomy was utilized as a model of perimenopausal and postmenopausal osteoporosis. A total of 100 mg/kg melatonin, or solvent alone, was added to the drinking water of the rats over 8 weeks. Perimenopausal rats immediately received intervention following ovariectomy while postmenopausal rats received intervention 8 weeks after ovariectomy. All rats underwent overdose anesthesia following intervention after which blood samples and femurs were collected for further analysis. Rat femurs were scanned using micro-CT and examined histologically. The serum levels of melatonin and osteogenic biochemical markers were measured and the expression of osteogenesis-associated genes (Runx2, Sp7) were quantified by real-time quantitative PCR. Alkaline phosphatase (ALP) activity and the gene expression (Col1a1, Runx2, Alpl, and Bglap) were measured after bone marrow mesenchymal stem cells (BMSCs) were osteogenically induced, both with and without melatonin in vitro. ALP staining and Alizarin Red S staining were used to identify osteogenesis. RESULTS: Analysis by micro-CT and histological staining demonstrated that bone mass decreased and bone microarchitecture deteriorated over time after ovariectomy. Intervention with melatonin increased bone mass in normal, perimenopausal, and postmenopausal osteoporotic rats. Serum levels of ALP continuously increased after ovariectomy while osteocalcin levels initially rose, then decreased. Melatonin increased the serum levels of ALP and osteocalcin and mRNA expression levels of Runx2 and Sp7 in normal and postmenopausal rats, the opposite of the markers in perimenopausal rats. In vitro study demonstrated that 100 µmol/L melatonin increased the mRNA expression of Col1a1, Runx2, and Alpl three and/or seven days after intervention, and Alpl and Bglap 14 d after intervention. Melatonin increased ALP activity and the extent of ALP and matrix mineralization in the late stage of osteogenesis. CONCLUSIONS: Bone mass continuously decreased after ovariectomy, while melatonin increased bone mass and ameliorated bone metabolism in normal, perimenopausal, and postmenopausal osteoporotic rats due to the induction of osteogenic differentiation in BMSCs.

Pirfenidone attenuates synovial fibrosis and postpones the progression of osteoarthritis by anti-fibrotic and anti-inflammatory properties in vivo and in vitro.

BACKGROUND: Osteoarthritis (OA) is a disease of the entire joint involving synovial fibrosis and inflammation. Pathological changes to the synovium can accelerate the progression of OA. Pirfenidone (PFD) is a potent anti-fibrotic drug with additional anti-inflammatory properties. However, the influence of PFD on OA is unknown. METHODS: Proliferation of human fibroblast-like synoviocytes (FLSs) after treatment with TGF-ß1 or PFD was evaluated using a Cell Counting Kit-8 assay and their migration using a Transwell assay. The expression of fibrosis-related genes (COL1A1, TIMP-1, and ACTA-2) and those related to inflammation (IL-6 and TNF-α) was quantified by real-time quantitative PCR. The protein expression levels of COL1A1, α-SMA (coded by ACTA-2), IL-6 and TNF-α were measured by enzyme-linked immunosorbent assay. A rabbit model of OA was established and then PFD was administered by gavage. The expression of genes related to fibrosis (COL1A1, TIMP-1, and ADAM-12) and inflammation (IL-6 and TNF-α) was measured using RNA extracted from the synovium. Synovial tissue was examined histologically after staining with H&E, Masson's trichrome, and immunofluorescence. Synovitis scores, the volume fraction of collagen, and mean fluorescence intensity were calculated. Degeneration of articular cartilage was analyzed using a Safranin O-fast green stain and OARSI grading. RESULTS: The proliferation of FLSs was greatest when induced with 2.5 ng/ml TGF-ß1 although it did not promote their migration. Therefore, 2.5 ng/ml TGF-ß1 was used to stimulate the FLSs and evaluate the effects of PFD, which inhibited the migration of FLSs at concentrations as low as 1.0 mg/ml. PFD decreased the expression of COL1A1 while TGF-ß1 increased both mRNA and protein expression levels of IL-6 but had no effect on α-SMA or TNF-α expression. PFD decreased mRNA expression levels of COL1A1, IL-6, and TNF-α in vivo. H&E staining and synovitis scores indicated that PFD reduced synovial inflammation, while Masson's trichrome and immunofluorescence staining suggested that PFD decreased synovial fibrosis. Safranin O-Fast Green staining and the OARSI scores demonstrated that PFD delayed the progression of OA. CONCLUSIONS: PFD attenuated synovial fibrosis and inflammation, and postponed the progression of osteoarthritis in a modified Hulth model of OA in rabbits, which was related to its anti-fibrotic and anti-inflammatory properties.

The comparative efficacies of intravenous administration and intra-articular injection of tranexamic acid during anterior cruciate ligament reconstruction for reducing postoperative hemarthrosis: a prospective randomized study.

BACKGROUND: Hemarthrosis after anterior cruciate ligament (ACL) reconstruction can create many adverse joint effects. Tranexamic acid (TXA) can be used to minimize hemarthrosis and associated pain after ACL reconstruction. We aimed to compare the efficacies of intravenous (IV) administration and intra-articular (IA) injection of TXA during ACL reconstruction for reducing postoperative hemarthrosis. METHODS: A total of 120 patients who underwent arthroscopic ACL reconstruction were included in this prospective and randomized study. All patients were randomized into three groups: IV group, IA group and placebo group. Patients in the IV group received intravenously administered TXA (15 mg/kg in 100 mL of saline solution) 10 min before tourniquet release; patients in the IA group received intra-articular TXA (15 mg/kg in 100 mL of saline solution) injected via the drainage tube; and patients in the placebo group received an equivalent volume of normal saline administered into the knee joint cavity and intravenously. Drainage tubes were removed 24 h after surgery, and all enrolled patients experienced a 4-week follow-up period. The drain output volume, visual analogue scale (VAS) score, patellar circumference, hemarthrosis grade and Lysholm score of all patients were recorded. RESULTS: Both the IV group and the IA group had significantly lower drain output volumes at day 1, lower VAS scores at weeks 1 and 2, smaller patellar circumferences at weeks 1 and 2, and lower hemarthrosis grades at weeks 1 and 2 than the placebo group (p < 0.05). There were no significant differences in drain output volume, VAS score, patellar circumference or hemarthrosis grade between the IV group and the IA group at any time point (p > 0.05). No obvious differences in Lysholm score were observed between any pair of groups at week 4 (p > 0.05)). Neither infection nor deep vein thrombosis occurred in any group. CONCLUSIONS: Both intravenous administration and intra-articular injection can reduce intra-articular hemarthrosis, joint pain and swelling during ACL reconstruction. No significant difference in the efficacies of reducing hemarthrosis, joint pain and swelling was found between intravenous administration and intra-articular injection. TRIAL REGISTRATION: The study was registered by the Chinese Clinical Trial Registry (The comparative efficacies of intravenous administration and intra-articular injection of tranexamic acid during anterior cruciate ligament reconstruction; ChiCTR-INR-17012217 ; August 1, 2017).

The patellofemoral morphology and the normal predicted value of tibial tuberosity-trochlear groove distance in the Chinese population.

BACKGROUND: Our objective was to obtain normal patellofemoral measurements to analyse sex and individual differences. In addition, the absolute values and indices of tibial tuberosity-trochlear groove (TT-TG) distances are still controversial in clinical application. A better method to enable precise prediction is still needed. METHODS: Seventy-eight knees of 78 participants without knee pathologies were included in this cross-sectional study. A CT scan was conducted for all participants and three-dimensional knee models were constructed using Mimics and SolidWorks software. We measured and analysed 19 parameters including the TT-TG distance and dimensions and shapes of the patella, femur, tibia, and trochlea. LASSO regression was used to predict the normal TT-TG distances. RESULTS: The dimensional parameters, TT-TG distance, and femoral aspect ratio of the men were significantly larger than those of women (all p values < 0.05). However, after controlling for the bias from age, height, and weight, there were no significant differences in TT-TG distances and anterior-posterior dimensions between the sexes (all p values > 0.05). The Pearson correlation coefficients between the anterior femoral offset and other indexes were consistently below 0.3, indicating no relationship or a weak relationship. Similar results were observed for the sulcus angle and the Wiberg index. Using LASSO regression, we obtained four parameters to predict the TT-TG distance (R2 = 0.5612, p < 0.01) to achieve the optimal accuracy and convenience. CONCLUSIONS: Normative data of patellofemoral morphology were provided for the Chinese population. The anterior-posterior dimensions of the women were thicker than those of men for the same medial-lateral dimensions. More attention should be paid to not only sex differences but also individual differences, especially the anterior condyle and trochlea. In addition, this study provided a new method to predict TT-TG distances accurately.

Identification of potential miRNA biomarkers for traumatic osteonecrosis of femoral head.

Traumatic osteonecrosis of femoral head (TONFH) is a common orthopedic disease caused by physical injury in hip. However, the unclear pathogenesis mechanism of TONFH and lacking of simple noninvasive early diagnosis method cause the necessity of hip replacement for most patients with TONFH. In this study, we aimed to identify circulating microRNAs (miRNAs) by integrated bioinformatics analyses as potential biomarker of TONFH. mRNA expression profiles were downloaded from the Gene Expression Omnibus database. Then we combined two miRNA screen methods: Weighted gene co-expression network analysis and fold change based differentially expressed miRNAs analysis. As a result, we identified 14 key miRNAs as potential biomarkers for TONFH. Besides, 302 target genes of these miRNAs were obtained and the miRNA-mRNA interaction network was constructed. Furthermore, the results of Kyoto Encyclopedia of Gene and Genome pathway analysis, Gene Ontology function analysis, protein-protein interaction (PPI) network analysis and PPI network module analysis showed close correlation between these 14 key miRNAs and TONFH. Then we established receiver operating characteristic curves and identified 6-miRNA signature with highly diagnosis value including miR-93-5p (area under the curve [AUC] = 0.93), miR-1324 (AUC = 0.92), miR-4666a-3p (AUC = 0.92), miR-5011-3p (AUC = 0.92), and miR-320a (AUC = 0.89), miR-185-5p (AUC = 0.89). Finally, the results of quantitative real-time polymerase chain reaction confirmed the significantly higher expression of miR-93-5p and miR-320a in the serum of patients with ONFH. These circulating miRNAs could serve as candidate early diagnosis markers and potential treatment targets of TONFH.

MicroRNA-211-5p promotes apoptosis and inhibits the migration of osteosarcoma cells by targeting proline-rich protein PRR11.

Osteosarcoma remains fatal in adolescents and young adults, with a 5-year survival rate of less than 20%. However, the details for mechanisms that regulate osteosarcoma metastasis are poorly understood. We analyzed the expression levels of miR-211-5p in clinical samples of osteosarcoma as well as cell lines, and found that the expression of miR-211-5p was reduced in osteosarcoma. Moreover, induction of miR-211-5p in several osteosarcoma cell lines dramatically inhibited their migration and invasiveness. Furthermore, miR-211-5p overexpression led to a significant increase in the apoptosis of osteosarcoma cell. Importantly, our in vivo xenograft experiments showed that miR-211-5p strongly inhibits tumorigenesis. Additionally, functional experiments demonstrated that miR-211-5p suppresses the expression of proline-rich protein 11 (PRR11) by directly binding to the 3' region of PRR11 mRNA. Moreover, we showed that PRR11 overexpression attenuated the increase of apoptosis and decreased migration and invasiveness when the upstream miR-211-5p was overexpressed. Our data provide new insights into the mechanisms that regulate osteosarcoma metastasis, and novel potential pharmaceutical targets for personalized medicine.

Long noncoding RNA PWRN1 is lowly expressed in osteosarcoma and modulates cancer proliferation and migration by targeting hsa-miR-214-5p.

BACKGROUND: We examined the expression pattern, clinical relevance, and molecular mechanisms of lncRNA PWRN1 in human osteosarcoma. METHODS: qPCR was used to measure PWRN1 expressions in cell lines and tumor samples osteosarcoma. The correlations between PWRN1 and cancer patients' clinicopathological properties and survival were examined. PWRN1 was ectopically overexpressed in MG-63 and 143B cells to assess its function on cancer cell proliferation, cisplatin chemoresistance, and in vivo xenotransplant growth. The ceRNA candidate of PWRN1, miR-214-5p was examined in osteosarcoma cells. In addition, miR-214-5p and PWRN1 were double-overexpressed in osteosarcoma cells to investigate the regulatory role of epigenetic axis PWRN1/miR-214-5p in osteosarcoma. RESULTS: We found that PWRN1 was downregulated in both osteosarcoma cells and human tumors. PWRN1 downregulation was correlated with advanced stage, metastasis, and low survival rate in cancer patients. PWRN1 overexpression in osteosarcoma cells significantly inhibited their proliferation, cisplatin chemoresistance, and in vivo growth. In addition, we demonstrated that PWRN1 directly bound miR-214-5p and suppressed its expression in osteosarcoma cells. Furthermore, we showed that miR-214-5p overexpression reversed the anti-cancer effects of PWRN1 on osteosarcoma cell proliferation and cisplatin chemoresistance. CONCLUSION: Our data provide new insights into the epigenetic axis of PWRN1/miR-214-5p in regulating osteosarcoma progression and chemoresistance. PWRN1 may also be a biomarker to predicting cancer patients' poor prognosis and novel pharmaceutical targets for personalized medicine.

In vitro antibacterial activity and cytocompatibility of magnesium-incorporated poly(lactide-co-glycolic acid) scaffolds.

BACKGROUND: Bone defects are often combined with the risk of infection in the clinic, and artificial bone substitutes are often implanted to repair the defective bone. However, the implant materials are carriers for bacterial growth, and biofilm can form on the implant surface, which is difficult to eliminate using antibiotics and the host immune system. Magnesium (Mg) was previously reported to possess antibacterial potential. METHODS: In this study, Mg was incorporated into poly(lactide-co-glycolic acid) (PLGA) to fabricate a PLGA/Mg scaffold using a low-temperature rapid-prototyping technique. All scaffolds were divided into three groups: PLGA (P), PLGA/10 wt% Mg with low Mg content (PM-L) and PLGA/20 wt% Mg with high Mg content (PM-H). The degradation test of the scaffolds was conducted by immersing them into the trihydroxymethyl aminomethane-hydrochloric acid (Tris-HCl) buffer solution and measuring the change of pH values and concentrations of Mg ions. The antibacterial activity of the scaffolds was investigated by the spread plate method, tissue culture plate method, scanning electron microscopy and confocal laser scanning microscopy. Additionally, the cell attachment and proliferation of the scaffolds were evaluated by the cell counting kit-8 (CCK-8) assay using MC3T3-E1 cells. RESULTS: The Mg-incorporated scaffolds degraded and released Mg ions and caused an increase in the pH value. Both PM-L and PM-H inhibited bacterial growth and biofilm formation, and PM-H exhibited higher antibacterial activity than PM-L after incubation for 24 and 48 h. Cell tests revealed that PM-H exerted a suppressive effect on cell attachment and proliferation. CONCLUSIONS: These findings demonstrated that the PLGA/Mg scaffolds possessed favorable antibacterial activity, and a higher content of Mg (20%) exhibited higher antibacterial activity and inhibitory effects on cell attachment and proliferation than low Mg content (10%).

Effects of delayed hip replacement on postoperative hip function and quality of life in elderly patients with femoral neck fracture.

BACKGROUND: For various reasons, some elderly patients with femoral neck fracture undergo delayed surgical treatment. There is little information about the effect of delayed treatment on postoperative hip function and quality of life. The aim of this study was to investigate the effect of delayed hip arthroplasty on hip function, quality of life, and satisfaction in patients with femoral neck fractures. METHODS: Forty-seven patients with femoral neck fracture and hip replacement delayed over 21 days served as the delayed group (D group). Patients with femoral neck fracture, matched 1:1 for age and sex, and hip replacement within 7 days served as the control group (C group). The Harris hip score (HHS) and health-related quality of life (HRQoL) were assessed before surgery and 3 months, 6 months and 1 year postoperatively. The satisfaction questionnaires were completed by the patients themselves at the last follow-up. RESULTS: The HHS in the C group was lower than that in the D group (32.64 ± 9.11 vs. 46.32 ± 9.88, P < 0.05) before surgery but recovered faster after surgery. The HHS in the D group was lower than that in the C group 1 year postoperatively (85.2 ± 3.80 vs. 89.8 ± 3.33, P < 0.05). The patients' quality of life changed similarly to their HHS. The HHS 1 year after surgery was related to the preoperative HHS in group D (rs = 0.521, P < 0.01). Patients in the D group showed significantly higher satisfaction scores than those in the C group (P < 0.05). CONCLUSIONS: Hip function in patients with femoral neck fracture surgery delayed over 21 days recovered more slowly than that in those who underwent surgery within 7 days. However, they were more satisfied with the surgery. Moderate hip movement to ameliorate the lower limb muscle atrophy was recommended for patients facing a temporary inability to undergo surgery.

Incorporation of nanosized calcium silicate improved osteointegration of polyetheretherketone under diabetic conditions.

Diabetes can impair osteoblastic functions and negatively interfere with osteointegration at the bone/implant interface. Previously, we prepared a nanosized calcium silicate (CS) incorporated-polyetheretherketone (PK) biocomposite (CS/PK) and found that the CS/PK composite exhibited enhanced osteoblast functions in vitro and osteointegration in vivo, but its bioperformance under diabetic conditions remained elusive. In this study, MC3T3-E1 cells incubated on CS/PK and PK samples were subjected to diabetic serum (DS) and normal serum (NS); cell attachment, morphology, spreading, proliferation, and osteogenic differentiation were compared to assess in vitro osteoblastic functions on the surfaces of different materials. An in vivo test was performed on diabetic rabbits implanted with CS/PK or PK implants into the cranial bone defect to assess the osteointegration ability of the implants. In vitro results showed that diabetes inhibited osteoblastic functions evidenced by impaired morphology and spreading, and decreased attachment, proliferation, and osteogenic differentiation compared with the findings under normal conditions. Notably, CS/PK ameliorated osteoblastic disfunction under diabetic conditions in vitro. In vivo results from micro-CT and histologic examinations revealed that rabbits with CS/PK implants exhibited improved osteointegration at the bone/implant interface under diabetic conditions compared with PK. Therefore, the CS/PK composite improved the impaired osteointegration induced by diabetes and is a promising orthopedic or craniofacial implant material that may obtain good clinical performance in diabetic patients.

Inhibition of microRNA-495 suppresses chondrocyte apoptosis through activation of the NF-κB signaling pathway by regulating CCL4 in osteoarthritis.

As a common form of arthritis, osteoarthritis (OA) represents a degenerative disease, characterized by articular cartilage damage and synovium inflammation. Recently, the role of various microRNAs (miRs) and their specific expression in OA has been highlighted. Therefore, the aim of the current study was to elucidate the role by which miR-495 and chemokine ligand 4 (CCL4) influence the development and progression of OA. OA mice models were established, after which the CCL4 and collagen levels as well as cell apoptosis were determined in cartilage tissue of OA mice. The chondrocytes of the OA mice models were subsequently treated with a series of miR-495 mimic, inhibitor, and siRNA against CCL4. Afterwards, miR-495 expressions as well as the levels of CCL4, p50, p65, and IkBa and the extent of IkBa phosphorylation in addition to the luciferase activity of NF-kB were measured accordingly. Finally, cell apoptosis and cell cycle distribution were detected. miR-495 was highly expressed while NF-κB, CCL4, and collagen II were poorly expressed. Cell apoptosis was elevated in the cartilage tissue of the OA mice. CCL4 was a potential target gene of miR-495. Downregulation of miR-495 led to accelerated chondrocyte proliferation accompanied by diminished cell apoptosis among the OA mice. Taken together, the results of the current study demonstrated that inhibition of miR-495 suppressed chondrocyte apoptosis and promoted its proliferation through activation of the NF-κB signaling pathway by up-regulation of CCL4 in OA.

Downregulation of long noncoding RNA LOC101928134 inhibits the synovial hyperplasia and cartilage destruction of osteoarthritis rats through the activation of the Janus kinase/signal transducers and activators of transcription signaling pathway by upregulating IFNA1.

Osteoarthritis (OA) is the most common disease of arthritis, a chronic joint disease that is always correlated with massive destruction such as cartilage destruction, inflammation of the synovial membrane, and so on. This study aims to explore the role of long noncoding RNA (lncRNA) LOC101928134 in the synovial hyperplasia and cartilage destruction, more specifically, in the Janus kinase/signal transducers and activators of transcription (JAK/STAT) signaling pathway in an OA rat model. Microarray-based gene expression analysis was conducted to screen out the lncRNA differentially expressed in OA and predict the target gene of the lncRNA with the involvement of the signaling pathway through Kyoto encyclopedia of genes and genomes (KEGG) analysis. A model of OA was established and treated with the small interfering RNA LOC101928134/inhibitor of JAK/STAT signaling pathway to investigate the relationship among LOC101928134, IFNA1, and the JAK/STAT signaling pathway in OA. The effect of LOC101928134 on the serum levels of IFNA1, interleukin-1ß, and tumor necrosis factor-α, and the apoptosis of synovial and cartilage cells was evaluated. LOC101928134, which was found to be highly expressed in knee joint synovial tissues of OA rats, regulated the expression of IFNA1 gene and inhibited JAK/STAT signaling pathway. Downregulation of LOC101928134 resulted in reduced knee joint synovitis, relived inflammatory damage, and knee joint cartilage damage of OA rats. Besides, synovial cell apoptosis was enhanced upon LOC101928134 downregulation, while cartilage cell apoptosis of OA rats was suppressed. These results demonstrate that downregulation of LOC101928134 suppresses the synovial hyperplasia and cartilage destruction of OA rats via activation of JAK/STAT signaling pathway by upregulating IFNA1, providing a new candidate for the treatment of OA.

Cryptotanshinone inhibits RANKL-induced osteoclastogenesis by regulating ERK and NF-κB signaling pathways.

Osteoporosis (OS) is one of the most common healthy problems characterized by low bone mass. Osteoclast, the primary bone-resorbing cell, is responsible for destructive bone diseases including osteoporosis (OS). Cryptotanshinone (CTS), an active component extracted from the root of Salvia miltiorrhiza bunge, has been shown to prevent the destruction of cartilage and the thickening of subchondral bone in mice osteoarthritis models. However, its molecular mechanism in osteoclastogenesis needs to be determined. The aim of the current study was to explore the effect of CTS on osteoclastogenesis and further evaluate the underlying mechanism. Our results showed that CTS inhibited receptor activator of NF-κB ligand (RANKL)-induced the increase in tartrate-resistant acid phosphatase (TRAP) activity in bone marrow-derived macrophages (BMMs). In addition, the expressions of osteoclastogenesis-related marker proteins and nuclear factor of activated T-cells (NFAT) activation were suppressed by CTS treatment in BMMs. Furthermore, CTS attenuated RANKL-induced ERK phosphorylation and NF-κB activation in BMMs. These findings indicated that CTS inhibited RANKL-induced osteoclastogenesis by inhibiting ERK phosphorylation and NF-κB activation in BMMs. Thus, CTS may function as an inhibitor of osteoclastogenesis and may be considered as an alternative medicine for the prevention and treatment of OS.

Bone marrow macrophage M2 polarization and adipose-derived stem cells osteogenic differentiation synergistically promote rehabilitation of bone damage.

By differentiating into and the balance being regulated between M1 (pro-inflammatory) and M2 (anti-inflammatory) heterogeneous populations, macrophages play critical roles during the host immune response in various physiological contexts in both health and diseases. Besides regulating innate and adaptive immune capacity, macrophages are also decisively involved in tissue homeostasis. However, how resident macrophages are regulated after tissue damages is still far from elucidation. In the present study, we found that adipose-derived stem cells (ADSCs) apparently promote bone defect rehabilitation in vivo via skewing differentiation of bone marrow-derived macrophage (BMDMs) towards anti-inflammatory M2 macrophages. In vitro data demonstrated that although ADSCs have the potential to differentiate to osteoblasts and adipose cells by using standard tissue culture-differentiating conditions, these mesenchymal progenitors are mainly regulated to differentiate into osteoblasts with overexpressed runt-related transcription factor 2, osteoprotegerin, osterix, and downregulated receptor activator of nuclear factor κB ligand in the presence of BMDMs-conditioned medium. Whereas BMDMs are polarized toward M2 macrophages with higher levels of arginase 1 and mannose receptor, but lower levels of inducible nitric oxide synthase and tumor necrosis factor-α when cocultured with ADSCs. In short, all these findings collectively demonstrated that ADSCs and resident host cells can synergistically contribute to the bony repair through mutual regulation of their differentiation and cytokine secretion.

Carbonic anhydrase III protects osteocytes from oxidative stress.

Osteocytes are master orchestrators of bone remodeling; they control osteoblast and osteoclast activities both directly via cell-to-cell communication and indirectly via secreted factors, and they are the main postnatal source of sclerostin and RANKL (receptor activator of NF-kB ligand), two regulators of osteoblast and osteoclast function. Despite progress in understanding osteocyte biology and function, much remains to be elucidated. Recently developed osteocytic cell lines-together with new genome editing tools-has allowed a closer look at the biology and molecular makeup of these cells. By using single-cell cloning, we identified genes that are associated with high Sost/sclerostin expression and analyzed their regulation and function. Unbiased transcriptome analysis of high- vs. low-Sost/sclerostin-expressing cells identified known and novel genes. Dmp1 (dentin matrix protein 1), Dkk1 (Dickkopf WNT signaling pathway inhibitor 1), and Phex were among the most up-regulated known genes, whereas Srpx2, Cd200, and carbonic anhydrase III (CAIII) were identified as novel markers of differentiated osteocytes. Aspn, Enpp2, Robo2, Nov, and Serpina3g were among the transcripts that were most significantly suppressed in high-Sost cells. Considering that CAII was recently identified as being regulated by Sost/sclerostin and capable of controlling mineral homeostasis, we focused our attention on CAIII. Here, we report that CAIII is highly expressed in osteocytes, is regulated by parathyroid hormone both in vitro and in vivo, and protects osteocytes from oxidative stress.-Shi, C., Uda, Y., Dedic, C., Azab, E., Sun, N., Hussein, A. I., Petty, C. A., Fulzele, K., Mitterberger-Vogt, M. C., Zwerschke, W., Pereira, R., Wang, K., Divieti Pajevic, P. Carbonic anhydrase III protects osteocytes from oxidative stress.

The induction of ferroptosis by impairing STAT3/Nrf2/GPx4 signaling enhances the sensitivity of osteosarcoma cells to cisplatin.

Recent studies have indicated that promoting ferroptosis is a promising approach to attenuate drug resistance of cancer cells. Hence, this study aimed to induce ferroptosis in osteosarcoma cells, thereby increasing the sensitivity to cisplatin. Osteosarcoma cells MG63 and Saos-2 were incubated with increasing doses of cisplatin to generate cisplatin-resistant strains, MG63/DDP and Saos-2/DDP. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and flow cytometry assays were performed to evaluate cell proliferation and cell death, respectively. Malondialdehyde (MDA), reactive oxygen species (ROS), and lipid oxidation in cells were measured to evaluate the degree of cell ferroptosis. MG63/DDP and Saos-2/DDP cells showed increased viability and decreased death rate compared with MG63 and Saos-2 cells, respectively, upon cisplatin treatment. Western blotting analysis indicated that protein levels of p-STAT3 (Ser727), nuclear factor erythroid 2-related factor 2 (Nrf2), and glutathione peroxidase 4 (GPx4) in drug-resistant strains increased significantly in response to cisplatin. Co-treatment with cisplatin and agonists of ferroptosis, Erastin, and RSL3, remarkably increased MDA, ROS, lipid oxidation, and sensitivity to cisplatin, in MG63/DDP and Saos-2/DDP cells. Similar results were observed by co-treatment of cells with cisplatin and a STAT3 inhibitor. The reduction of protein levels of p-STAT3 (Ser727), Nrf2, and GPx4 in MG63/DDP and Saos-2/DDP cells resulted in increased ferroptosis and sensitivity to cisplatin. These results indicate that cisplatin-resistant osteosarcoma cells inhibited ferroptosis after exposure to low doses of cisplatin. However, ferroptosis agonists and STAT3 inhibitor reactivated ferroptosis in the cells and consequently increased sensitivity to cisplatin. This study demonstrates a new approach to attenuate resistance of osteosarcoma to cisplatin in vitro .

microRNA-590-5p targets transforming growth factor ß1 to promote chondrocyte apoptosis and autophagy in response to mechanical pressure injury.

This study aimed to investigate the role of miR-590-5p in chondrocyte apoptosis and autophagy in response to mechanical pressure injury in vitro, as well as to elucidate its regulatory mechanism in the pathogenesis of osteoarthritis. We applied mechanical pressure of 10 MPa to chondrocytes for 60 minutes to establish the chondrocyte model of experimentally induced mechanical injury. We then investigated the expression of miR-590-5p in the injury model and the effects of miR-590-5p dysregulation on the expression of cell apoptosis-related and autophagy-related proteins. Cell apoptosis was detected by flow cytometry. Moreover, the potential targets of miR-590-5p were investigated. Mechanical pressure injury resulted in a significantly increased expression of miR-590-5p. Suppression of miR-590-5p significantly increased chondrocytes viability, inhibited chondrocytes apoptosis and autophagy in response to mechanical pressure injury. In addition, mechanical pressure injury led to a decreased expression of transforming growth factor ß1 (TGFß1). Moreover, TGFß1 was confirmed as a direct target of miR-590-5p. Knockdown of TGFß1 significantly induced chondrocytes apoptosis and autophagy in response to mechanical pressure injury, which was contrary to the effects of miR-590-5p suppression. Furthermore, overexpression of TGFß1 and miR-590-5p at the same time significantly reversed the effects of overexpression of miR-590-5p alone on chondrocytes apoptosis and autophagy. Our results indicate that upregulation of miR-590-5p may target TGFß1 to promote chondrocyte apoptosis and autophagy in response to mechanical pressure injury, thus contributing to the pathogenesis of osteoarthritis.