Maresin-1 suppresses IL-1ß-induced MMP-13 secretion by activating the PI3K/AKT pathway and inhibiting the NF-κB pathway in synovioblasts of an osteoarthritis rat model with treadmill exercise.

Aim: Maresin-1 is a metabolite of docosahexaenoic acid (DHA) that has potential anti-inflammatory effects. To explore whether maresin-1 changes and has a therapeutic effect in osteoarthritis (OA) model rats undergoing treadmill exercise, we examined endogenous maresin-1 in a single-session treadmill experiment and OA model rats were treated with maresin-1, moreover, we examined the effects of maresin-1 on IL-1ß induced rat fibroblast-like synoviocytes (FLSs) and possible mechanisms.Methods: In single-session treadmill experiment, 48 rats were randomly divided into 3 groups and performed three different intensities of exercise (15.2 m/min, 0°; 19.3 m/min, 5°; 26.8 m/min, 10°) for 60 min. Intra-articular lavage fluid (IALF) samples were harvested after 0, 2, and 4 h from each group (n = 4) and maresin-1 levels were evaluated by ELISA. Another 30 rats were treated with monosodium iodoacetate (MIA) to induce osteoarthritis and exogenous maresin-1 (MaR-1) and were divided into three groups (n = 10, OA: MIA, OAM: MIA+MaR1, and CG: control group). The level of injury was evaluated by OARSI and Mankin scores, and the levels of type II collagen and MMP13 were evaluated by immunohistochemistry. FLSs were obtained from the knee joint of SD rats, and the expression of MMP13 and activation of the PI3k/Akt and NF-κB p65 pathways in IL-1ß-induced FLSs were evaluated by western blotting.Results: Maresin-1 levels were increased in IALF at 4 h after exercise, and type II collagen increased in cartilage and MMP13 decreased in the synovium after treatment with maresin-1 in MIA-induced osteoarthritis. The results of vitro experiment showed decreased MMP13, activation of the PI3k/Akt pathway, and suppression of the NF-κB p65 pathway upon treatment with maresin-1 in IL-1ß-induced FLSs.Conclusions: The changes in maresin-1 in IALF, as seen in our single-section treadmill exercise, provides an explanation for the therapeutic effect of appropriate-strength treadmill exercise on osteoarthritis, and our experiments confirmed the therapeutic effect of maresin-1 both in vivo and in vitro.

Cemented hemiarthroplasty versus proximal femoral nail antirotation in the management of intertrochanteric femoral fractures in the elderly: a case control study.

BACKGROUND: The treatment for intertrochanteric femoral fractures (IFF) among the elderly has been a controversial topic. Hemiarthroplasty (HA) and proximal femoral nail antirotation (PFNA) have their own advantages in the management of IFF. Hence, this study aims to compare and analyze differences in the effectiveness of both procedures on IFF among the elderly. METHODS: Overall, 99 patients (81.09 ± 8.29 years; 68 women) underwent HA or PFNA from January 2016 to May 2020. IFF were classified according to the Arbeitsgemeins für Osteosynthesefragen (AO) classification. The difference in underlying diseases, the American Society of Anesthesiologists (ASA) grade, Singh index, Harris scores, surgical time, intraoperative bleeding, postoperative blood test results, postoperative number of days to partially bearing weight, and survival outcomes were analyzed. Postoperative follow-ups were performed every 3 months. RESULTS: There was no significant difference in the AO classification, underlying diseases, ASA grade, Singh index, surgical time, and survival outcomes of the HA (45 patients) group and PFNA group (54 patients). The HA group was associated with earlier partial weight-bearing (HA: 4 [2 ~ 4.5] days, PFNA: 10 [8~14] days). It also had a higher total Harris score than the PFNA group at the 6-month follow-up visit (HA: 86.8 [81.90 ~ 90.23], PFNA: 83.48 [75.13 ~ 88.23]). Harris scores decreased more in patients aged ≥90 years in the PFNA group than in the HA group. The postoperative stress recovery rate in the HA group was faster based on postoperative blood test results. CONCLUSIONS: PFNA and HA have good therapeutic effects in the treatment of IFF. The advantages of HA were reflected in short-term weight bearing, faster recovery from stress, and better joint function in the long term. This advantage is more obvious in the patient population aged over 90 years. Therefore, we suggest that surgeons should consider the benefit of HA in the treatment of IFF among the elderly. TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR2000035814. Registered 17 August 2020, https://www.chictr.org.cn/showproj.aspx?proj=57083.

CDK14 is regulated by IGF2BP2 and involved in osteogenic differentiation via Wnt/ß-catenin signaling pathway in vitro.

AIMS: Cyclin-dependent kinase (CDK) family proteins involve in various cellular processes via regulating the cell cycle; however, their expression during osteogenic differentiation and postmenopausal osteoporosis remains poorly understood. MAIN METHODS: Using bioinformatics, we screened for CDK14 bound to Insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2) and explored its expression in vitro with time-gradient model and in a mouse model of postmenopausal osteoporosis, building on prior research. Subsequently, we investigated its effect on osteoblast proliferation, cell cycle dynamics, and osteogenic differentiation by administering CDK14 siRNA and the covalent inhibitor FMF-04-159-2. Furthermore, we examined the interaction between IGF2BP2 and CDK14. Finally, we validated the regulatory role of CDK14 on the Wnt/ß-catenin pathway. KEY FINDINGS: Our findings demonstrate a time-dependent CDK14 expression patterns during osteogenic differentiation of MC3T3-E1 cell line, with an initial increase followed by gradual decline over time. Notably, CDK14 expression exhibited significant reduction in bone tissue of postmenopausal osteoporosis mouse model. CDK14 inhibition altered osteoblast cell cycle dynamics, significantly reduced cellular proliferation capacity, and impaired osteogenic differentiation ability. IGF2BP2 interacted with CDK14 mRNA, and stabilizing mRNA's structure and inhibiting its degradation. Additionally, CDK14 facilitated Low-density lipoprotein receptor-related protein 6 (LRP6) and Glycogen synthase kinase 3ß (GSK3ß) phosphorylation, thus regulating ß-catenin levels. SIGNIFICANCE: These findings provide further insight into the molecular mechanisms governing osteoblast proliferation, differentiation and osteoporosis.

One-base-mismatch CRISPR-based transistors for single nucleotide resolution assay.

An effective strategy for accurately detecting single nucleotide variants (SNVs) is of great significance for genetic research and diagnostics. However, strict amplification conditions, complex experimental instruments, and specialized personnel are required to obtain a satisfactory tradeoff between sensitivity and selectivity for SNV discrimination. In this study, we present a CRISPR-based transistor biosensor for the rapid and highly selective detection of SNVs in viral RNA. By introducing a synthetic mismatch in the crRNA, the CRISPR-Cas13a protein can be engineered to capture the target SNV RNA directly on the surface of the graphene channel. This process induces a fast electrical signal response in the transistor, obviating the need for amplification or reporter molecules. The biosensor exhibits a detection limit for target RNA as low as 5 copies in 100 µL, which is comparable to that of real-time quantitative polymerase chain reaction (PCR). Its operational range spans from 10 to 5 × 105 copy mL-1 in artificial saliva solution. This capability enables the biosensor to discriminate between wild-type and SNV RNA within 15 min. By introducing 10 µL of swab samples during clinical testing, the biosensor provides specific detection of respiratory viruses in 19 oropharyngeal specimens, including influenza A, influenza B, and variants of SARS-CoV-2. This study emphasizes the CRISPR-transistor technique as a highly accurate and sensitive approach for field-deployable nucleic acid screening or diagnostics.

Recent Developments in Polyurea Research for Enhanced Impact Penetration Resistance and Blast Mitigation.

Polyurea has gained significant attention in recent years as a functional polymer material, specifically regarding blast and impact protection. The molecular structure of polyurea is characterized by the rapid reaction between isocyanate and the terminal amine component, and forms an elastomeric copolymer that enhances substrate protection against blast impact and fragmentation penetration. At the nanoscale, a phase-separated microstructure emerges, with dispersed hard segment microregions within a continuous matrix of soft segments. This unique microstructure contributes to the remarkable mechanical properties of polyurea. To maximize these properties, it is crucial to analyze the molecular structure and explore methods like formulation optimization and the incorporation of reinforcing materials or fibers. Current research efforts in polyurea applications for protective purposes primarily concentrate on construction, infrastructure, military, transportation and industrial products and facilities. Future research directions should encompass deliberate formulation design and modification, systematic exploration of factors influencing protective performance across various applications and the integration of numerical simulations and experiments to reveal the protective mechanisms of polyurea. This paper provides an extensive literature review that specifically examines the utilization of polyurea for blast and impact protection. It encompasses discussions on material optimization, protective mechanisms and its applications in blast and impact protection.

NECAB3 promotes the migration and invasion of liver cancer cells through HIF-1α/RIT1 signaling pathway.

Liver cancer is a prevalent malignant tumor with high mortality worldwide, making it urgent to explore new targets for liver cancer therapy. N-terminal EF-hand calcium binding protein 3 (NECAB3) is a new recognized regulator of cancer, while its role in liver cancer remained elusive. Thus, the study clarified the action of NECAB3 on liver cancer development and explored the detailed mechanism. We found that NECAB3 was enhanced in liver cancer. Knockdown of NECAB3 restrained liver cancer cell migration and invasion. Besides, knockdown of NECAB3 suppressed the activation of the hypoxia-inducible factor 1-alpha (HIF-1α)/Ras like without CAAX 1 (RIT1) pathway. Furthermore, NECAB3 regulated liver cancer migration and invasion through modulating RIT1 expression. Moreover, downregulation of NECAB3 suppressed liver cancer tumor growth in vivo. In conclusion, NECAB3 was upregulated in liver cancer. Knockdown of NECAB3 suppressed aggressive phenotype of liver cancer via modulating the HIF-1α/RIT1 axis, providing a possible target for liver cancer therapy.

Ginsenoside Compound K Ameliorates Osteoarthritis by Inhibiting the Chondrocyte Endoplasmic Reticulum Stress-Mediated IRE1α-TXNIP-NLRP3 Axis and Pyroptosis.

Osteoarthritis (OA) is a common joint disease, and studies have reported that the endoplasmic reticulum stress (ERS) in chondrocytes caused by the cartilage tissue damage could mediate the activation of Nod-like receptor protein 3 (NLRP3) inflammasomes through inositol-requiring enzyme 1 alpha (IRE1α) and thioredoxin interacting protein (TXNIP). Ginsenoside compound K (CK) has an inhibitory effect on IRE1α activation. However, the role of IRE1α-TXNIP and its interaction with CK are still unclear. In this study, we examined the role and mechanism of action of CK in OA. We found that CK ameliorated OA and ERS in IL-1ß-treated chondrocytes and a monoiodoacetate-induced rat OA model. The effect of CK on inflammation, pyroptosis, and ERS was blocked by the ERS inducer tunicamycin. In conclusion, CK hindered OA progression by inhibiting the ERS-IRE1α-TXNIP-NLRP3 axis. Overall, our data indicate that CK could be useful in the treatment of OA and other chronic inflammatory diseases.

Mechanical Stimulation Protects Against Chondrocyte Pyroptosis Through Irisin-Induced Suppression of PI3K/Akt/NF-κB Signal Pathway in Osteoarthritis.

Irisin, a myokine secreted by muscle during physical exercise, is known to have biological activities in different cell types. Chondrocyte inflammation and pyroptosis have been shown to play important roles in osteoarthritis (OA). In this study, we investigated the effects of exercise-induced irisin during different intensities of treadmill exercise in a rat OA model and the anti-inflammatory and antipyroptosis mechanism of irisin in OA chondrocytes. Forty-eight SD rats (n = 8) were randomly assigned to control (CG), OA (OAG), OA groups under different intensities of treadmill exercise (OAL, OAM, and OAH), OAM + irisin neutralizing antibodies group (OAM + irisin (NA)). The levels of irisin and the severity of OA between groups were detected using ELISA, histology, immunohistochemistry, X-ray and computed tomography and magnetic resonance imaging. The anti-inflammatory and antipyroptosis mechanisms of irisin were investigated in vitro in OA chondrocytes preincubated with recombinant irisin (0, 5, or 10 ng/ml) for 1 h before treatment with interleukin-1ß (IL-1ß) for 24 h mRNA and protein expression levels were determined using quantitative reverse transcription polymerase chain reaction, and western blot analyses. Morphological changes and cell death associated with pyroptosis were examined using transmission electron microscopy, flow cytometry and immunofluorescence. Moderate-intensity treadmill exercise increased the levels of irisin, exhibiting the best therapeutic effects on OA which could be suppressed by irisin neutralizing antibodies. Irisin not only recovered the expression of collagen II and attenuated that of MMP-13 and ADAMTS-5 in IL-1ß-induced OA chondrocytes by inhibiting the PI3K/Akt/NF-κB signaling pathway, but also inhibited the activity of nod-like receptor protein-3 (NLRP3)/caspase-1, thus ameliorating pyroptosis in chondrocytes. In conclusion, moderate mechanical stimulation protects against chondrocyte pyroptosis through irisin-induced suppression of PI3K/Akt/NF-κB signal pathway in osteoarthritis.

The anti-inflammatory effects of 15-HETE on osteoarthritis during treadmill exercise.

AIMS: Investigate the involvement of 15-hydroxyeicosatetraenoic acid (15-HETE), an anti-inflammatory molecule, on the beneficial effects of exercise therapy for osteoarthritis (OA). MAIN METHODS: 15-HETE (10 µM, twice a week) and monosodium iodoacetate (MIA) (1 mg) were injected into rat knee joints. Treadmill exercise was applied on OA rat. Primary rat chondrocytes were treated with 15-HETE, LY294002 and interleukin (IL)-1ß. Rats undergo a 1 hour single session treadmill exercise once. 15-HETE levels in the knee joint were evaluated using ELISA after a single session of treadmill exercise on healthy and OA rats. Matrix metalloproteinase (MMP)3, MMP-13, a disintegrin and metalloproteinase with thrombospondin motif (ADAMTS)-5, p-Akt, Akt, and collagen type 2 (COL2) expression were evaluated using RT-PCR and western blotting. OA degree was evaluated using X-ray, scored by Osteoarthritis Research Society International (OARSI) and Mankin scores. COL2 and MMP-13 expression in articular was evaluated using immunohistochemistry. KEY FINDINGS: Medium intensity exercise alleviated OA. 15-HETE levels after exercise was increased. 15-HETE inhibited IL-1ß-induced inflammation in primary chondrocytes and increased p-Akt levels. LY294002 blocked the effect of 15-HETE in vitro. Finally, 15-HETE alleviated cartilage damage, inhibited MMP-13 expression, and increased COL2 expression in joint cartilage tissue. SIGNIFICANCE: Treadmill exercise alleviates OA and increases 15-HETE levels in the knee joint, which suppresses inflammation in chondrocytes via PI3k-Akt signalling in vitro and in vivo.

RNA methyltransferase NSUN2 promotes growth of hepatocellular carcinoma cells by regulating fizzy-related-1 in vitro and in vivo.

The aim of the study was to investigate the role of NSUN2 (NOP2/Sun RNA Methyltransferase Family Member 2) in hepatocellular carcinoma (HCC). The expressions of NSUN2 and FZR1 were measured. Cell viability, proliferation, and apoptosis were assessed. HCC xenograft in nude mouse model was established. Tumor weight and volume were examined. Tumor tissues were collected for immunohistochemistry (IHC). TCGA database analysis and clinical sample testing suggested that the transcript levels of NSUN2 and FZR1 were increased in HCC tissues. NSUN2 knockdown inhibited HCC cell viability and proliferation, and promoted cell apoptosis. Moreover, the effects of NSUN2 could be countered by overexpressing FZR1. In animal experiment, NSUN2 silencing suppressed tumor growth in nude mice by downregulating FZR1. In conclusion, NSUN2 has a regulatory effect on HCC cell proliferation and apoptosis. NSUN2 knockout could inhibit cellular processes in HCC and tumor growth, likely via FZR1 inhibition. This finding has not only revealed the role of NSUN2 in HCC growth, but also suggests a promising target for HCC treatment.

Moderate-intensity exercise alleviates pyroptosis by promoting autophagy in osteoarthritis via the P2X7/AMPK/mTOR axis.

Instability and excessive use of the knee joint can cause osteoarthritis (OA). Reasonable exercise can enhance the stability of the knee joint and prevent and relieve the occurrence and development of OA. As a key switch for inflammation, P2X purinoceptor 7 (P2X7) has attracted much attention in studies of OA. Exercise can regulate P2X7 expression and activation. However, the role of P2X7 in exercise-based prevention and treatment of OA is unknown. We previously showed that moderate-intensity exercise can significantly alleviate OA symptoms. Accordingly, in this study, we evaluated the effects of exercise on P2X7 expression and activation in chondrocytes. Micro-computed tomography, hematoxylin, and eosin staining, Toluidine Blue O staining, immunohistochemistry, and terminal deoxynucleotidyl transferase dUTP nick-end labeling experiments showed that P2X7 expression was lower in the moderate-intensity exercise group than in the inflammation and low- and high-intensity exercise groups. Additionally, chondrocyte death, cartilage destruction, and the degree and severity of pyroptosis were significantly reduced, whereas autophagy levels were significantly increased in the moderate-intensity exercise group. Cell Counting Kit-8 assay, lactate dehydrogenase release, flow cytometry, enzyme-linked immunosorbent assay, cell fluorescence, western blot, reverse transcription-quantitative polymerase chain reaction, and transmission electron microscopy experiments showed that moderate activation of P2X7 promoted autophagy through the AMP-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) signaling pathway and promoted autolysosome targeting for degradation of the inflammasome component NLRP3, thereby inhibiting pyroptosis. Additionally, the use of AMPK and mTOR activators and inhibitors indicated that the AMPK-mTOR signaling pathway, as the downstream of P2X7, played a key role in delaying the occurrence and development of OA. We propose that moderate-intensity exercise promoted chondrocyte autophagy through the P2X7/AMPK/mTOR signal axis to alleviate pyroptosis. Our findings provide novel insights into the positive and preventative effects of exercise on OA.

P2X7 Receptor Induces Pyroptotic Inflammation and Cartilage Degradation in Osteoarthritis via NF-κB/NLRP3 Crosstalk.

Osteoarthritis (OA) is an urgent public health problem; however, the underlying causal mechanisms remain unclear, especially in terms of inflammatory mediators in cartilage degradation and chondrocyte imbalance. P2X7 receptor (P2X7R) is a critical inflammation switch, but few studies have examined its function and mechanisms in OA-like pyroptotic inflammation of chondrocytes. In this study, Sprague-Dawley rats were injected in the knee with monosodium iodoacetate (MIA) to induce OA, followed by multiple intra-articular injections with P2X7R antagonist A740003, P2X7R agonist BzATP, NF-κB inhibitor Bay 11-7082, and NLRP3 inhibitor CY-09. Primary rat chondrocytes were harvested and treated similarly. We assessed cell viability, damage, and death via cell viability assay, lactate dehydrogenase (LDH) release, and flow cytometry. Concentrations of adenosine triphosphate (ATP) and interleukin- (IL-) 1ß in cell culture supernatant and joint cavity lavage fluid were analyzed by enzyme-linked immunosorbent assay. Changes in expression levels of P2X7 and inflammation-related indicators were analyzed by immunofluorescence, quantitative reverse-transcription polymerase chain reaction, and western blotting. Cell morphology changes and pyroptosis were observed using transmission electron microscopy. Histology, immunohistochemistry, and microcomputed tomography were used to analyze damage to bone and cartilage tissues and assess the severity of OA. Similar to MIA, BzATP reduced cell viability and collagen II expression in a dose-dependent manner. Conversely, A740003 ameliorated MIA-induced cartilage degradation and OA-like pyroptotic inflammation by rescuing P2X7, MMP13, NF-κB p65, NLRP3, caspase-1 (TUNEL-positive and active), and IL-1ß upregulation. Additionally, A740003 reduced the caspase-1/propidium iodide double-positive rate, LDH concentration, and reactive oxygen species production. These effects also occurred via coincubation with Bay 11-7082 and CY-09. In conclusion, activated P2X7 promoted extracellular matrix degradation and pyroptotic inflammation in OA chondrocytes through NF-κB/NLRP3 crosstalk, thus, aggravating the symptoms of OA. The study findings suggest P2X7 as a potential target for inflammation treatment, providing new avenues for OA research and therapy.