Sipeimine ameliorates osteoarthritis progression by suppression of NLRP3 inflammasome-mediated pyroptosis through inhibition of PI3K/AKT/NF-κB pathway: An in vitro and in vivo study.

Background: Osteoarthritis (OA) is a chronic and degenerative condition that persists and progresses over time. Sipeimine (Sip), a steroidal alkaloid derived from Fritillariae Cirrhosae Bulbus, has attracted considerable attention due to its exceptional anti-inflammatory, analgesic, antioxidant, and anti-cancer characteristics. However, Sip's effects on OA and its mechanism still need further research. Methods: This study utilized network pharmacology to identify initial targets for Sip. Functional associations of Sip in OA were clarified through Gene Ontology (GO) enrichment analysis, bioinformatically analyzing a list of targets. Subsequently, Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis assessed pathways linked to Sip's therapeutic efficacy in OA. Molecular docking techniques explored Sip's binding affinity with key targets. In vitro experiments assessed Sip's impact on lipopolysaccharide (LPS)-induced pro-inflammatory factors and its protective effects on collagen-II and aggrecan degradation within the extracellular matrix (ECM). Western blotting and fluorescence analyses were conducted to determine Sip-mediated signaling pathways. Moreover, in vivo experiments using a mouse OA model validated Sip's therapeutic efficacy. Results: The results from network pharmacology revealed a total of 57 candidate targets for Sip in OA treatment. GO enrichment analysis demonstrated a robust correlation between Sip and inflammatory response, response to LPS and NF-κB-inducing kinase activity in OA. KEGG enrichment analysis highlighted the significance of NF-κB and PI3K-AKT pathways in Sip's therapeutic potential for OA. Furthermore, molecular docking results demonstrated Sip's robust binding affinity with p65 and PI3K. In vitro experiments demonstrated Sip's effectively suppressed the expression of pro-inflammatory factors induced by LPS, such as COX-2, iNOS, IL-1ß, and IL-18. Besides, Sip counteracted the degradation of collagen-II and aggrecan within the ECM and the expression of MMP-13 and ADAMTS-5 mediated by LPS. The safeguarding effects of Sip were ascribed to its inhibition of PI3K/AKT/NF-κB pathway and NLRP3 inflammasome mediated pyroptosis. Additionally, in vivo experiments revealed that Sip could alleviate the subchondral remodeling, cartilage degeneration, synovitis as well as ECM degradation a mouse model of OA. Conclusion: Sip exhibited potential in attenuating OA progression by suppressing the PI3K/AKT/NF-κB pathway, consequently inhibiting the activation of NLRP3 inflammasome and pyroptosis. The translational potential statement: The translational potential of this articleThis study provides a biological rationale for the use of Sip as a potential candidate for OA treatment, provide a new concept for the cartilage targeted application of natural compounds.

Cucurbitacin B attenuates osteoarthritis development by inhibiting NLRP3 inflammasome activation and pyroptosis through activating Nrf2/HO-1 pathway.

Osteoarthritis (OA) is a complicated joint disorder characterized by inflammation that causes joint destruction. Cucurbitacin B (CuB) is a naturally occurring triterpenoid compound derived from plants in the Cucurbitaceae family. The aim of this study is to investigate the potential role and mechanisms of CuB in a mouse model of OA. This study identified the key targets and potential pathways of CuB through network pharmacology analysis. In vivo and in vitro studies confirmed the potential mechanisms of CuB in OA. Through network pharmacology, 54 potential targets for CuB in treating OA were identified. The therapeutic potential of CuB is associated with the nod-like receptor pyrin domain 3 (NLRP3) inflammasome and pyroptosis. Molecular docking results indicate a strong binding affinity of CuB to nuclear factor erythroid 2-related factor 2 (Nrf2) and p65. In vitro experiments demonstrate that CuB effectively inhibits the expression of pro-inflammatory factors induced by interleukin-1ß (IL-1ß), including cyclooxygenase-2, inducible nitric oxide synthase, IL-1ß, and IL-18. CuB inhibits the degradation of type II collagen and aggrecan in the extracellular matrix (ECM), as well as the expression of matrix metalloproteinase-13 and a disintegrin and metalloproteinase with thrombospondin motifs-5. CuB protects cells by activating the Nrf2/hemeoxygenase-1 (HO-1) pathway and inhibiting nuclear factor-κB (NF-κB)/NLRP3 inflammasome-mediated pyroptosis. Moreover, in vivo experiments show that CuB can slow down cartilage degradation in an OA mouse model. CuB effectively prevents the progression of OA by inhibiting inflammation in chondrocytes and ECM degradation. This action is further mediated through the activation of the Nrf2/HO-1 pathway to inhibit NF-κB/NLRP3 inflammasome activation. Thus, CuB is a potential therapeutic agent for OA.

20-Deoxyingenol alleviates intervertebral disc degeneration by activating TFEB in nucleus pulposus cells.

Intervertebral disc degeneration (IVDD) is a prevalent degenerative disease with significant adverse implications for patients' quality of life and socioeconomic status. Although the precise etiology of IVDD remains elusive, the senescence of nucleus pulposus cells is recognized as the primary pathogenic factor of IVDD; however, drugs that may targetedly inhibit senescence are still lacking. In the current study, we evaluated the small-molecule active drug 20-Deoxyingenol(20-DOI) for its effects on combating senescence and delaying the progression of IVDD. In vitro experiments revealed that the administration of 20-DOI displayed inhibitory effects on senescence and the senescence-related cGAS-STING pathway of nucleus pulposus cells. Additionally, it exhibited the ability to enhance lysosome activity and promote autophagy flux within nucleus pulposus cells. Subsequent investigations elucidated that the inhibitory impact of 20-DOI on nucleus pulposus cell senescence was mediated through the autophagy-lysosome pathway. This effect was diminished in the presence of transcription factor EB (TFEB) small hairpin RNA (shRNA), thereby confirming the regulatory role of 20-DOI on the autophagy-lysosome pathway and senescence through TFEB. In vivo experiments demonstrated that 20-DOI effectively impeded the progression ofIVDD in rats. These findings collectively illustrate that 20-DOI may facilitate the autophagy-lysosomal pathway by activating TFEB, thereby suppressing the senescence in nucleus pulposus cells, thus suggesting 20-DOI as a promising therapeutic approach for IVDD.

Metformin inactivates the cGAS-STING pathway through autophagy and suppresses senescence in nucleus pulposus cells.

Intervertebral disc degeneration (IVDD) is a complex process involving many factors, among which excessive senescence of nucleus pulposus cells is considered to be the main factor. Our previous study found that metformin can inhibit senescence in nucleus pulposus cells; however, the mechanism of such an action was still largely unknown. In the current study, we found that metformin inactivates the cGAS-STING pathway during oxidative stress. Furthermore, knockdown of STING (also known as STING1) suppresses senescence, indicating that metformin might exert its effect through the cGAS-STING pathway. Damaged DNA is a major inducer of the activation of the cGAS-STING pathway. Mechanistically, our study showed that DNA damage was reduced during metformin treatment; however, suppression of autophagy by 3-methyladenine (3-MA) treatment compromised the effect of metformin on DNA damage. In vivo studies also showed that 3-MA might diminish the therapeutic effect of metformin on IVDD. Taken together, our results reveal that metformin may suppress senescence via inactivating the cGAS-STING pathway through autophagy, implying a new application for metformin in cGAS-STING pathway-related diseases.

Immune-responsive gene 1/itaconate activates nuclear factor erythroid 2-related factor 2 in microglia to protect against spinal cord injury in mice.

The pathophysiology of spinal cord injury (SCI) involves primary injury and secondary injury. Secondary injury is a major target for SCI therapy, whereas microglia play an important role in secondary injury. The immunoresponsive gene 1 (Irg-1) has been recorded as one of the most significantly upregulated genes in SCI tissues in gene chip data; however, its role in SCI remains unclear. This study aims to illustrate the role of Irg-1 as well as its regulated metabolite itaconate in SCI. It was demonstrated that the expression of Irg-1 was increased in spinal cord tissues in mice as well as in microglia stimulated by lipopolysaccharides (LPS). It was also shown that overexpression of Irg-1 may suppress LPS-induced inflammation in microglia, while these protective effects were attenuated by Nrf2 silencing. In vivo, overexpression of Irg-1 was shown to suppress neuroinflammation and improve motor function recovery. Furthermore, treatment of microglia with itaconate demonstrated similar inflammation suppressive effects as Irg-1 overexpression in vitro and improved motor function recovery in vivo. In conclusion, the current study shows that Irg-1 and itaconate are involved in the recovery process of SCI, either Irg-1 overexpression or itaconate treatment may provide a promising strategy for the treatment of SCI.

Itaconate attenuates osteoarthritis by inhibiting STING/NF-κB axis in chondrocytes and promoting M2 polarization in macrophages.

Osteoarthritis (OA) is a progressive joint disease characterized by the degradation and destruction of articular cartilage, which is involved with pathological microenvironmental alterations induced by damaged chondrocytes and inflammatory macrophages. However, the current therapies cannot effectively alleviate the progression of OA. Our previous studies have shown that the pathological process of OA progression is accompanied by DNA damage, and inhibition of STING, a key molecule in DNA damage, may become a potential method for the treatment of OA. Itaconate, a metabolite highly expressed in macrophages under inflammatory conditions, has shown a wide range of anti-inflammatory effects, but its effect on OA and its underlying mechanism has not yet been studied. In this study, we found that exogenous supplementation of itaconate can activate Nrf2, and accordingly inhibit the STING-dependent NF-κB pathway, thereby alleviating the inflammation, ECM degeneration and senescence of chondrocytes stimulated by IL-1ß. In addition, itaconate can regulate the polarization of RAW264.7 macrophages, further reducing the apoptosis of chondrocytes. In vivo, intra-articular injection of itaconate reduces the degradation of cartilage and inflammation of synovial membrane in the mouse OA model. In conclusion, the present work suggests that exogenous supplementation of itaconate inhibits the inflammation, senescence and ECM degeneration of chondrocytes through the Nrf2/STING/NF-κB axis and regulates the polarization of synovial macrophages, thereby ameliorating the progression of OA, which supports that itaconate as a potential drug for the treatment of OA.

Betulin Alleviates the Inflammatory Response in Mouse Chondrocytes and Ameliorates Osteoarthritis via AKT/Nrf2/HO-1/NF-κB Axis.

Osteoarthritis (OA) is a common degenerative joint disease featuring the degeneration, destruction, and ossification of cartilage. Inflammation which may facilitate OA occurrence and development is considered as the main pathological factor. Betulin, a natural product extracted from birch bark, has been commonly used for inflammation treatment; however, its role in OA remains unclear. This study is aimed to explore whether betulin can suppress IL-1ß-induced inflammation in chondrocytes and alleviate OA in vitro and in vivo. In in vitro studies, the generation of pro-inflammatory factors, such as interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), prostaglandin E2 (PGE2), and nitric oxide (NO), was assessed using the enzyme-linked immunosorbent assay (ELISA) and Griess reaction. As revealed by results, betulin inhibited the expression of pro-inflammatory mediators. In addition, the protein expressions of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), matrix metalloproteinase (MMP-13), thrombospondin motifs 5 (ADAMTS5), Collagen II, and Aggrecan were quantified using Western blot analysis. We found that betulin could inhibit the generation of COX-2 and iNOS induced by IL-1ß, indicating that betulin has anti-inflammatory effects in chondrocytes. Furthermore, betulin downregulates the expression of MMP-13 and ADAMTS-5 and upregulates the expression of Collagen II and Aggrecan, indicating that it can inhibit the degradation of the extracellular matrix. In mechanism, betulin activated the AKT/Nrf2 pathway and inhibited the phosphorylation of p65. In in vivo studies, administration of betulin in vivo could inhibit cartilage destruction and inflammatory progression. Therefore, these findings suggest that betulin may alleviate IL-1ß-induced OA via the AKT/Nrf2/HO-1/NF-κB signal axis, and betulin may be a potential drug for the treatment of OA.

Limonin Inhibits IL-1ß-Induced Inflammation and Catabolism in Chondrocytes and Ameliorates Osteoarthritis by Activating Nrf2.

Osteoarthritis (OA), a degenerative disorder, is considered to be one of the most common forms of arthritis. Limonin (Lim) is extracted from lemons and other citrus fruits. Limonin has been reported to have anti-inflammatory effects, while inflammation is a major cause of OA; thus, we propose that limonin may have a therapeutic effect on OA. In this study, the therapeutic effect of limonin on OA was assessed in chondrocytes in vitro in IL-1ß induced OA and in the destabilization of the medial meniscus (DMM) mice in vivo. The Nrf2/HO-1/NF-κB signaling pathway was evaluated to illustrate the working mechanism of limonin on OA in chondrocytes. In this study, it was found that limonin can reduce the level of IL-1ß induced proinflammatory cytokines such as INOS, COX-2, PGE2, NO, TNF-α, and IL-6. Limonin can also diminish the biosynthesis of IL-1ß-stimulated chondrogenic catabolic enzymes such as MMP13 and ADAMTS5 in chondrocytes. The research on the mechanism study demonstrated that limonin exerts its protective effect on OA through the Nrf2/HO-1/NF-κB signaling pathway. Taken together, the present study shows that limonin may activate the Nrf2/HO-1/NF-κB pathway to alleviate OA, making it a candidate therapeutic agent for OA.

High glucose suppresses autophagy through the AMPK pathway while it induces autophagy via oxidative stress in chondrocytes.

Diabetes (DB) is a risk factor for osteoarthritis progression. High glucose (HG) is one of the key pathological features of DB and has been demonstrated to induce apoptosis and senescence in chondrocytes. Autophagy is an endogenous mechanism that can protect cells against apoptosis and senescence. The effects of HG on autophagy in cells including chondrocytes have been studied; however, the results have been inconsistent. The current study aimed to elucidate the underlying mechanisms, which could be associated with the contrasting outcomes. The present study revealed that HG can induce apoptosis and senescence in chondrocytes, in addition to regulating autophagy dynamically. The present study demonstrated that HG can cause oxidative stress in chondrocytes and suppress the AMPK pathway in a dose-dependent manner. Elimination of oxidative stress by Acetylcysteine, also called N-acetyl cysteine (NAC), downregulated autophagy and alleviated HG-stimulated apoptosis and senescence, while activation of the AMPK signaling pathway by AICAR not only upregulated autophagy but also alleviated HG-stimulated apoptosis and senescence. A combined treatment of NAC and AICAR was superior to treatment with either NAC or AICAR. The study has demonstrated that HG can suppress autophagy through the AMPK pathway and induce autophagy via oxidative stress in chondrocytes.

Cardamonin protects nucleus pulposus cells against IL-1ß-induced inflammation and catabolism via Nrf2/NF-κB axis.

Intervertebral disc degeneration (IVDD) is one of the major causes of low back pain, but effective therapies are still lacking because of its complicated pathology. It has been demonstrated that increased levels of interleukin-1ß (IL-1ß) may promote the development of IVDD. Cardamonin (CAR) is a chalcone extracted from Alpinia katsumadai and other plants. It exhibits an anti-inflammatory effect in multiple diseases. In the present study, we investigated the protective effects of CAR on rat nucleus pulposus (NP) cells under IL-1ß stimulation in vitro and in a puncture-induced rat IVDD model in vivo. We explored the CAR treatment's inhibition of the expression of inflammatory factors such as cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), prostaglandin E2 (PGE2), nitric oxide (NO), tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) in rat NP cells. Moreover, the up-regulation of matrix metalloproteinase-13 (MMP-13) and thrombospondin motifs 5 (ADAMTS-5) and the degradation of aggrecan and collagen II induced by IL-1ß were reversed by CAR. Mechanistically, we demonstrated that CAR inhibited nuclear factor kappa B (NF-κB) signaling by activating the nuclear factor erythroid-derived 2-like 2 (Nrf2) in IL-1ß-induced rat NP cells. Furthermore, the protective effect of CAR was shown in the IVDD model through persistent intragastric administration. Taken together, our results revealed that CAR could activate the Nrf2/HO-1 signaling axis and be a novel agent for IVDD therapy.

20-Deoxyingenol alleviates osteoarthritis by activating TFEB in chondrocytes.

Osteoarthritis (OA) is an age-related degenerative disease and currently cannot be cured. Transcription factor EB (TFEB) is one of the major transcriptional factors that regulates autophagy and lysosomal biogenesis. TFEB has been shown to be an effective therapeutic target for many diseases including OA. The current study explores the therapeutic effects of 20-Deoxyingenol (20-DOI) on OA as well as its working mechanism on TFEB regulation. The in vitro study showed that 20-DOI may suppress apoptosis and senescence induced by oxidative stress in chondrocytes; it may also promote the nuclear localization of TFEB in chondrocytes. Knock-down of TFEB compromised the effects of 20-DOI on apoptosis and senescence. The in vivo study demonstrated that 20-DOI may postpone the progression of OA in mouse destabilization of the medial meniscus (DMM) model; it may also suppress apoptosis and senescence and promote the nuclear localization of TFEB in chondrocytes in vivo. This work suggests that 20-Deoxyingenol may alleviate osteoarthritis by activating TFEB in chondrocytes, while 20-DOI may become a potential drug for OA therapy.

Inhibition of LRRK2 restores parkin-mediated mitophagy and attenuates intervertebral disc degeneration.

OBJECTIVE: To elucidate the role of LRRK2 in intervertebral disc degeneration (IDD) as well as its mitophagy regulation mechanism. METHODS: The expression of LRRK2 in human degenerative nucleus pulposus tissues as well as in oxidative stress-induced rat nucleus pulposus cells (NPCs) was detected by western blot. LRRK2 was knocked down in NPCs by lentivirus (LV)-shLRRK2 transfection; apoptosis and mitophagy were assessed by western blot, TUNEL assay, immunofluorescence staining and mitophagy detection assay in LRRK2-deficient NPCs under oxidative stress. After knockdown of Parkin in NPCs with siRNA transfection, apoptosis and mitophagy were further assessed. In puncture-induced rat IDD model, X-ray, MRI, hematoxylin-eosin (HE) and Safranin O-Fast green (SO) staining were performed to evaluate the therapeutic effects of LV-shLRRK2 on IDD. RESULTS: We found that the expression of LRRK2 was increased in degenerative NPCs both in vivo and in vitro. LRRK2 deficiency significantly suppressed oxidative stress-induced mitochondria-dependent apoptosis in NPCs; meanwhile, mitophagy was promoted. However, these effects were abolished by the mitophagy inhibitor, suggesting the effect of LRRK2 on apoptosis in NPCs is mitophagy-dependent. Furthermore, Parkin knockdown study showed that LRRK2 deficiency activated mitophagy by recruiting Parkin. In vivo study demonstrated that LRRK2 inhibition ameliorated IDD in rats. CONCLUSIONS: The results revealed that LRRK2 is involved in the pathogenesis of IDD, while knockdown of LRRK2 inhibits oxidative stress-induced apoptosis through mitophagy. Thus, inhibition of LRRK2 may be a promising therapeutic strategy for IDD.

RNA-binding protein HuR suppresses senescence through Atg7 mediated autophagy activation in diabetic intervertebral disc degeneration.

OBJECTIVES: Diabetes is a risk factor for intervertebral disc degeneration (IVDD). Studies have demonstrated that diabetes may affect IVDD through transcriptional regulation; however, whether post-transcriptional regulation is involved in diabetic IVDD (DB-IVDD) is still unknown. This study was performed to illustrate the role of HuR, an RNA-binding protein, in DB-IVDD development and its mechanism. MATERIALS AND METHODS: The expression of HuR was evaluated in nucleus pulposus (NP) tissues from diabetic IVDD patients and in high glucose-treated NP cells. Senescence and autophagy were assessed in HuR over-expressing and downregulation NP cells. The mRNAs that were regulated by HuR were screened, and immunoprecipitation was applied to confirm the regulation of HuR on targeted mRNAs. RESULTS: The results showed that the expression of HuR was decreased in diabetic NP tissues and high glucose-treated NP cells. Downregulation of HuR may lead to increased senescence in high glucose-treated NP cells, while autophagy activation attenuates senescence in HuR deficient NP cells. Mechanistic study showed that HuR prompted Atg7 mRNA stability via binding to the AU-rich elements. Furthermore, overexpression of Atg7, but not HuR, may ameliorate DB-IVDD in rats in vivo. CONCLUSIONS: In conclusion, HuR may suppress senescence through autophagy activation via stabilizing Atg7 in diabetic NP cells; while Atg7, but not HuR, may serve as a potential therapeutic target for DB-IVDD.

Position of Coracoid Button Predicts Loss of Reduction in Acromioclavicular Joint Dislocation Patients Treated With the Suture-Button.

BACKGROUND: Loss of reduction is the most common complication after acromioclavicular (AC) joint dislocation treated with the suture-button. Some predictors of it are known, but finding new predictors is an ongoing process. In this study, we evaluate the importance of the position of the coracoid button. MATERIALS AND METHODS: Between April 2010 and February 2017, 186 patients with AC joint dislocation were identified. All patients were managed with the same surgical technique and postoperative protocol. The position of the coracoid button was determined immediately after surgery by anterior-posterior views of the operated shoulder and was classified as medial (Group A, 42 cases), central (Group B, 85 cases) and lateral (Group C, 59 cases) positions. The main outcome measurement was loss of reduction. The main analysis was the association between the coracoid button position and loss of reduction. RESULTS: No significant difference was found in the baseline characteristics among 3 groups. During follow-up, there were 15 cases (35.7%) developing loss of reduction in Group A, 5 cases (5.9%) in Group B and 26 cases (44.1%) in Group C. The rate of loss of reduction in Groups A and C were higher than that in Group B (p < .05). Moreover, there was no significant difference in the rate of reduction loss between lateral and medial positions of the coracoid buttons (p > .05). CONCLUSION: Our results indicated that both lateral and medial positions of the coracoid buttons could predict loss of reduction in AC joint dislocation patients treated with the suture-button.

RNA-Binding Protein HuR Suppresses Inflammation and Promotes Extracellular Matrix Homeostasis via NKRF in Intervertebral Disc Degeneration.

Intervertebral disc degeneration (IVDD) has been reported to be a major cause of low back pain. Studies have demonstrated that IVDD may be dysregulated at the transcriptional level; however, whether post-transcriptional regulation is involved is still unknown. The current study aimed to illustrate the role of Human antigen R (HuR), an RNA binding protein involved in post-transcriptional regulation, in IVDD. The results showed that the expression of HuR was decreased in degenerative nucleus pulposus (NP) tissues as well as in TNF-α-treated NP cells. Downregulation of HuR may lead to increased inflammation and extracellular matrix (ECM) degradation in TNF-α-treated NP cells; however, these effects were not reversed in HuR overexpressed NP cells. Inhibition of the NF-κB signaling pathway attenuates inflammation and ECM degradation in HuR-deficient NP cells. A mechanism study showed that HuR prompted NKRF mRNA stability via binding to its AU-rich elements, and upregulation of NKRF suppressed inflammation and ECM degradation in HuR-deficient NP cells. Furthermore, we found that NKRF, but not HuR, overexpression ameliorated the process of IVDD in rats in vivo. In conclusion, HuR suppressed inflammation and ECM degradation in NP cells via stabilizing NKRF and inhibiting the NF-κB signaling pathway; NKRF, but not HuR, may serve as a potential therapeutic target for IVDD.

ß-Hydroxyisovalerylshikonin inhibits IL-1ß-induced chondrocyte inflammation via Nrf2 and retards osteoarthritis in mice.

Osteoarthritis is a chronic degenerative disease characterized by cartilage destruction. It is the fourth most disabling disease worldwide and is currently incurable. Inflammation and extracellular matrix (ECM) degradation are considered to be substantial reasons for accelerating the progression of OA. ß-Hydroxyisoamylshikonin (ß-HIVS) is a natural naphthoquinone compound with anti-inflammatory and antioxidant activity. However, the effect of ß-HIVS on OA is still unclear. In this study, we found that ß-HIVS can down-regulate the expression of NO, PEG2, IL-6, TNF-α, COX-2, and iNOS, suggesting its anti-inflammatory effects in chondrocytes; we also found that ß-HIVS may down-regulate the expression of ADAMTS5 and MMP13 and up-regulate the expression of aggrecan and collagen II to inhibit the degradation of ECM. Mechanistically, ß-HIVS inhibited the NFκB pathway by activating the Nrf2/HO-1 axis, thereby exerting its anti-inflammatory and inhibitory effects on ECM degradation. In vivo experiments also proved the therapeutic effects of ß-HIVS on OA in mice, and Nrf2 is the target of ß-HIVS. These findings indicate that ß-HIVS may become a new drug for the treatment of OA.

S-allyl cysteine reduces osteoarthritis pathology in the tert-butyl hydroperoxide-treated chondrocytes and the destabilization of the medial meniscus model mice via the Nrf2 signaling pathway.

In this study, we used murine chondrocytes as an in vitro model and mice exhibiting destabilization of the medial meniscus (DMM) as an in vivo model to investigate the mechanisms through which S-allyl cysteine (SAC) alleviates osteoarthritis (OA). SAC significantly reduced apoptosis and senescence and maintained homeostasis of extracellular matrix (ECM) metabolism in tert-butyl hydroperoxide (TBHP)-treated chondrocytes. Molecular docking analysis showed a -CDOCKER interaction energy value of 203.76 kcal/mol for interactions between SAC and nuclear factor erythroid 2-related factor 2 (Nrf2). SAC increased the nuclear translocation of Nrf2 and activated the Nrf2/HO1 signaling pathway in TBHP-treated chondrocytes. Furthermore, Nrf2 knockdown abrogated the antiapoptotic, antisenescence, and ECM regulatory effects of SAC in TBHP-treated chondrocytes. SAC treatment also significantly reduced cartilage ossification and erosion, joint-space narrowing, synovial thickening and hypercellularity in DMM model mice. Collectively, these findings show that SAC ameliorates OA pathology in TBHP-treated chondrocytes and DMM model mice by activating the Nrf2/HO1 signaling pathway.

Detection of dorsal screw penetration during volar plating of the distal radius fractures: A comparison of different fluoroscopic views and screw sizes.

OBJECTIVE: The objective of this study was to compare different screw lengths combined with different fluoroscopic views to detect intraoperative dorsal screw penetration in distal radius fractures treated with volar locked plating. MATERIAL AND METHODS: From April 2014 to October 2018, one hundred and eighty patients were included. We divided the patients into four groups. Intraoperative AP and lateral views were taken and sizes of the screws were chosen based on actual measurement (Group A, 45 patients). AP, lateral and tangential views were taken and sizes of the screws were also chosen based on actual measurement (Group B, 45 patients). Intraoperative AP and lateral views were taken and the selected screws were 2mm shorter than actual measurement (Group C, 45 patients). AP, lateral and tangential views were taken and the selected screws were 2mm shorter than actual measurement (Group D, 45 patients). Prominent screws were changed intraoperatively according to each view. A computed tomography (CT) was taken postoperatively to identify residual prominent screws. RESULTS: The number of dorsally prominent screws exceeding 1mm was 6 of 301 in Group A (2.0%), 15 of 290 (5.2%) in Group B, 2 of 289 in Group C (0.7%), and 2 of 282 (0.7%) in Group D. All these prominent screws (25 screws) were exchanged for shorter screws during surgery. Group A and Group B had significant difference in detecting intraoperative dorsal screw penetration (p<0.05). Group C and Group D had no significant difference in detecting intraoperative dorsal screw penetration (p>0.05). Postoperative CT identified 12 additional prominent screws with≥1mm dorsal penetration in Group A, 2 screws in Group B, 1 screw in Group C and 0 screw in Group B respectively. Significant difference was found between Group A and Group B of CT results (p<0.05) while no statistical difference was found between Group C and Group D of CT results (p>0.05). DISCUSSIONS: Tangential view helped identify screw penetration. If tangential view was not available intraoperatively, screw penetration could also be avoided by downsizing the distal locking screw by 2mm shorter than actual measurement.

Projection of the Most Anterior Line of the Spinal Canal on Lateral Radiograph: An Anatomic Study for Percutaneous Kyphoplasty and Percutaneous Vertebroplasty.

ABSTRACTPurpose: To measure the projection of the most anterior line of the spinal canal on lateral radiographs of the vertebra (C3-L5) and evaluate the efficacy of the safety line (SL) in preventing intraspinal cement leakage in percutaneous kyphoplasty (PKP) and percutaneous vertebroplasty (PVP). Materials and Methods: Fifteen adult dry-bone spine specimens were analyzed. The projection of the SL was viewed on lateral radiographs. The distance between the SL and the posterior vertebral body line (PVBL) was measured. Two groups of patients were treated by PKP, and cement injection was stopped either before the PBVL (group 1) or before the SL (group 2) under lateral fluoroscopy. The rate of cement leakage was compared between the two groups. Results: The largest distance between the SL and PVBL was at L1 (5.22 ± 0.62 mm). From L1 to L5, the distance decreased progressively to 1.05 ± 0.64 mm. Similar variation was also observed from L1 to T1 (0.19 ± 0.18 mm). The postoperative computed tomography scan was more sensitive and accurate in detecting intraspinal leakage than radiography in group 1 (p = 0.000); however, there was no significant difference in sensitivity or accuracy between methods in group 2 (p = 0.063). The rate of intraspinal cement leakage was significantly higher in group 1 than group 2 (p = 0.000). Conclusions: The operator should frequently check to ensure that cement injection has stopped upon reaching the SL. Surgeons may benefit from this quantitative anatomical study of PKP and PVP.

Inhibition of EZH2 ameliorates cartilage endplate degeneration and attenuates the progression of intervertebral disc degeneration via demethylation of Sox-9.

BACKGROUND: Cartilaginous endplate (CEP) degeneration is considered as one of the major causes of intervertebral disc degeneration (IVDD) which causes low back pain. Recent studies have proved that epigenetic alteration is involved in a variety of diseases. This work explored the role of histone methyltransferase enhancer of zeste homologue 2 (EZH2) in CEP degeneration, as well as its underlying epigenetic mechanisms, and confirmed the effect of EZH2 knockdown on delaying IVDD development. METHODS: Western blotting, immunofluorescence staining, and ChIP assay were applied to demonstrate the molecular mechanism of EZH2 in CEP tissue. The therapeutic potential of EZH2 was investigated using puncture-induced rat models. FINDINGS: The EZH2 expression was upregulated in human and rat CEP tissue. It was also found that the overexpression of EZH2 suppressed the expression of Collagen II, aggrecan and Sox-9, and promoted the expression of ADTAMTS5 and MMP13 in rat endplate chondrocytes (EPCs), which could be reversed by EZH2 silencing. The correlation between EZH2 and Sox-9 was further explored, while overexpression of Sox-9 could reverse the effect of EZH2 in rat EPCs. Moreover, inhibition of EZH2 upregulated the level of Sox-9 by demethylating H3K27me3 at Sox-9 promoter sites, revealing the regulatory mechanism of EZH2 on Sox-9. Meanwhile, puncture-induced rat models showed that EZH2 knockdown exerted a protective effect on CEP and disc degeneration. INTERPRETATION: This study reveals that EZH2 inhibition is a promising strategy for mitigating the symptoms and progression of IVDD. FUNDING: This study was funded by the Natural Science Foundation of Zhejiang Province (Y16H060034). Authors declare that the funders had no involvement in the study design, data analysis and interpretation of the results.