SQSTM1-dependent autophagic degradation of PKM2 inhibits the production of mature IL1B/IL-1β and contributes to LIPUS-mediated anti-inflammatory effect

Degrasyn alleviates osteoarthritis by blocking macrophagic pyroptosis via suppressing NLRP3/GSDMD signaling pathway and protecting chondrocytes

Synovitis and cartilage destruction are crucial characteristics of osteoarthritis (OA). Inflammatory cytokines, such as IL-1β, are secreted by synovial macrophages, leading to cartilage destruction. Pyroptosis is a lytic form of programmed cell death, which could be triggered by the NLRP3 inflammasome of macrophages. Pyroptosis promotes the secretion of IL-1β and is supposed as a potential biomarker for OA. However, the function of Pyroptosis and NLRP3 inflammasome and its regulatory mechanism for activation is unclear in OA. In this study, we found that Degrasyn could alleviate the GSDMD-mediated pyroptosis of macrophages and the release of IL-1β, caspase-1, and LDH. Furthermore, it selectively impedes the form of ASC oligomer and speckle to effectively suppress the NLRP3 inflammasome during its assembly phase. Notably, Degrasyn exhibited potential chondroprotective effects in a co-culture system. Additionally, these results also indicate that Degrasyn mitigates synovitis and cartilage damage in a murine model of destabilization of the medial meniscus (DMM)-induced OA. In summary, Degrasyn emerges as a promising pharmaceutical agent for synovitis, paving the way for innovative therapeutic approaches to OA. Our findings underscore the potential of Degrasyn as a viable candidate for OA therapeutics, demonstrating its ability to regulate pyroptosis and NLRP3 inflammasome activation.

Echinatin protects from ischemic brain injury by attenuating NLRP3-related neuroinflammation

BACKGROUND

Microglia-mediated neuroinflammation is the major contributor to the secondary brain injury of ischemic stroke. NLRP3 is one of the major components of ischemia-induced microglial activation. Echinatin, a chalcone found in licorice, was reported to have the activity of anti-inflammation and antioxidant. However, the relative study of echinatin in microglia or ischemic stroke is still unclear.

METHODS

We intravenously injected echinatin or vehicle into adult ischemic male C57/BL6J mice induced by 60-min transient middle cerebral artery occlusion (tMCAO). The intraperitoneal injection was performed 4.5 h after reperfusion and then daily for 2 more days. Infarct size, blood brain barrier (BBB) leakage, neurobehavioral tests, and microglial-mediated inflammatory reaction were examined to assess the outcomes of echinatin treatment. LPS and LPS/ATP stimulation on primary microglia were used to explore the underlying anti-inflammatory mechanism of echinatin.

RESULTS

Echinatin treatment efficiently decreased the infarct size, alleviated blood brain barrier (BBB) damage, suppressed microglial activation, reduced the production of inflammatory factors (e.g., IL-1β, IL-6, IL-18, TNF-α, iNOS, COX2), and relieved post-stroke neurological defects in tMCAO mice. Mechanistically, we found that echinatin could suppress the NLRP3 assembly and reduce the production of inflammatory mediators independently of NF-κB and monoamine oxidase (MAO).

CONCLUSION

Based on our study, we have identified echinatin as a promising therapeutic strategy for the treatment of ischemic stroke.

Drugs/agents for the treatment of ischemic stroke: Advances and perspectives

Ischemic stroke (IS) poses a significant threat to global human health and life. In recent decades, we have witnessed unprecedented progresses against IS, including thrombolysis, thrombectomy, and a few medicines that can assist in reopening the blocked brain vessels or serve as standalone treatments for patients who are not eligible for thrombolysis/thrombectomy therapies. However, the narrow time windows of thrombolysis/thrombectomy, coupled with the risk of hemorrhagic transformation, as well as the lack of highly effective and safe medications, continue to present big challenges in the acute treatment and long-term recovery of IS. In the past 3 years, several excellent articles have reviewed pathophysiology of IS and therapeutic medicines for the treatment of IS based on the pathophysiology. Regretfully, there is no comprehensive overview to summarize all categories of anti-IS drugs/agents designed and synthesized based on molecular mechanisms of IS pathophysiology. From medicinal chemistry view of point, this article reviews a multitude of anti-IS drugs/agents, including small molecule compounds, natural products, peptides, and others, which have been developed based on the molecular mechanism of IS pathophysiology, such as excitotoxicity, oxidative/nitrosative stresses, cell death pathways, and neuroinflammation, and so forth. In addition, several emerging medicines and strategies, including nanomedicines, stem cell therapy and noncoding RNAs, which recently appeared for the treatment of IS, are shortly introduced. Finally, the perspectives on the associated challenges and future directions of anti-IS drugs/agents are briefly provided to move the field forward.

Low-Intensity Pulsed Ultrasound: A Physical Stimulus with Immunomodulatory and Anti-inflammatory Potential

Ultrasound has expanded into the therapeutic field as a medical imaging and diagnostic technique. Low-intensity pulsed ultrasound (LIPUS) is a kind of therapeutic ultrasound that plays a vital role in promoting fracture healing, wound repair, immunomodulation, and reducing inflammation. Its anti-inflammatory effects are manifested by decreased pro-inflammatory cytokines and chemokines, accelerated regression of immune cell invasion, and accelerated damage repair. Although the anti-inflammatory mechanism of LIPUS is not very clear, many in vitro and in vivo studies have shown that LIPUS may play its anti-inflammatory role by activating signaling pathways such as integrin/Focal adhesion kinase (FAK)/Phosphatidylinositol 3-kinase (PI3K)/Serine threonine kinase (Akt), Vascular endothelial growth factor (VEGF)/endothelial nitric oxide synthase (eNOS), or inhibiting signaling pathways such as Toll-like receptors (TLRs)/Nuclear factor kappa-B (NF-κB) and p38-Mitogen-activated protein kinase (MAPK). As a non-invasive physical therapy, the anti-inflammatory and immunomodulatory effects of LIPUS deserve further exploration.

Research trends and perspective of low-intensity pulsed ultrasound in orthopedic rehabilitation treatment based on Web of Science: A bibliometric analysis

BACKGROUND

Ultrasound has a long history as a diagnostic and therapeutic tool. Low-intensity pulsed ultrasound (LIPUS), whose intensity is below 300 mW/cm2, has been widely used in orthopedic rehabilitation treatment. However, the detailed bioeffects and underlying mechanisms of LIPUS treatment need to be explored.

OBJECTIVE

To make a comprehensive view of the field, bibliometric and visualization analysis was used to reveal the global research trends of LIPUS in orthopedics and rehabilitation treatment between 1994 and 2023.

METHODS

All literature data on LIPUS were retrieved from the Web of Science Core Collection database. VOSviewer and CiteSpace were applied for the bibliometric and visualization analysis.

RESULTS

A total of 760 publications were included. The distribution of publications generally showed an unstable rising trend. China had the highest number of publications (28.0%), and Chong Qing Medical University was the organization with the highest number of publications (5.8%). Ultrasound in Medicine and Biology had the highest number of publications (8.8%), while BMJ-British Medical Journal had the highest impact factor among the retrieved journals. Ling Qin from the Chinese University of Hong Kong was the most active researcher. Our overlay visualization map showed that the keywords such as pain, knee osteoarthritis, apoptosis, chondrocytes, cartilage, and autophagy, which link to osteoarthritis, have becoming the new research trends and hotspots.

CONCLUSION

LIPUS is a popular and increasingly important area of orthopedic rehabilitation, and collaboration of authors from different countries should be further strengthened. Predictably, clinical application of LIPUS on chronic inflammation-related diseases and regenerative medicine, and in-depth biological mechanisms are the orientations of LIPUS in orthopedic rehabilitation treatment.

Effectiveness of low-intensity pulsed ultrasound on osteoarthritis: molecular mechanism and tissue engineering

Osteoarthritis (OA) is distinguished by pathological alterations in the synovial membrane, articular cartilage, and subchondral bone, resulting in physical symptoms such as pain, deformity, and impaired mobility. Numerous research studies have validated the effectiveness of low-intensity pulsed ultrasound (LIPUS) in OA treatment. The periodic mechanical waves generated by LIPUS can mitigate cellular ischemia and hypoxia, induce vibration and collision, produce notable thermal and non-thermal effects, alter cellular metabolism, expedite tissue repair, improve nutrient delivery, and accelerate the healing process of damaged tissues. The efficacy and specific mechanism of LIPUS is currently under investigation. This review provides an overview of LIPUS's potential role in the treatment of OA, considering various perspectives such as the synovial membrane, cartilage, subchondral bone, and tissue engineering. It aims to facilitate interdisciplinary scientific research and further exploration of LIPUS as a complementary technique to existing methods or surgery. Ongoing research is focused on determining the optimal dosage, frequency, timing, and treatment strategy of LIPUS for OA. Additional research is required to clarify the precise mechanism of action and potential impacts on cellular, animal, and human systems prior to its integration into therapeutic applications.

A Retrospective Study of Biological Risk Factors Associated with Primary Knee Osteoarthritis and the Development of a Nomogram Model

Aim

A high percentage of the elderly suffer from knee osteoarthritis (KOA), which imposes a certain economic burden on them and on society as a whole. The purpose of this study is to examine the risk of KOA and to develop a KOA nomogram model that can timely intervene in this disease to decrease patient psychological burdens.

Methods

Data was collected from patients with KOA and without KOA at our hospital from February 2021 to February 2023. Initially, a comparison was conducted between the variables, identifying statistical differences between the two groups. Subsequently, the risk of KOA was evaluated using the Least Absolute Shrinkage and Selection Operator method and multivariate logistic regression to determine the most effective predictive index and develop a prediction model. The examination of the disease risk prediction model in KOA includes the corresponding nomogram, which encompasses various potential predictors. The assessment of disease risk entails the application of various metrics, including the consistency index (C index), the area under the curve (AUC) of the receiver operating characteristic curve, the calibration chart, the GiViTi calibration band, and the model for predicting KOA. Furthermore, the potential clinical significance of the model is explored through decision curve analysis (DCA) and clinical influence curve analysis.

Results

The study included a total of 582 patients, consisting of 392 patients with KOA and 190 patients without KOA. The nomogram utilized age, haematocrit, platelet count, apolipoprotein a1, potassium, magnesium, hydroxybutyrate dehydrogenase, creatine kinase, and estimated glomerular filtration rate as predictors. The C index, AUC, calibration plot, Giviti calibration band, DCA and clinical influence KOA indicated the ability of nomogram model to differentiate KOA.

Conclusion

Using nomogram based on disease risk, high-risk KOA can be identified directly without imaging.

Near Infrared Responsive Gold Nanorods Attenuate Osteoarthritis Progression by Targeting TRPV1

Osteoarthritis (OA) is the most common degenerative joint disease worldwide, with the main pathological manifestation of articular cartilage degeneration. It have been investigated that pharmacological activation of transient receptor potential vanilloid 1 (TRPV1) significantly alleviated cartilage degeneration by abolishing chondrocyte ferroptosis. In this work, in view of the thermal activated feature of TRPV1, Citrate-stabilized gold nanorods (Cit-AuNRs) is conjugated to TRPV1 monoclonal antibody (Cit-AuNRs@Anti-TRPV1) as a photothermal switch for TRPV1 activation in chondrocytes under near infrared (NIR) irradiation. The conjugation of TRPV1 monoclonal antibody barely affect the morphology and physicochemical properties of Cit-AuNRs. Under NIR irradiation, Cit-AuNRs@Anti-TRPV1 exhibited good biocompatibility and flexible photothermal responsiveness. Intra-articular injection of Cit-AuNRs@Anti-TRPV1 followed by NIR irradiation significantly activated TRPV1 and attenuated cartilage degradation by suppressing chondrocytes ferroptosis. The osteophyte formation and subchondral bone sclerosis are remarkably alleviated by NIR-inspired Cit-AuNRs@Anti-TRPV1. Furthermore, the activation of TRPV1 by Cit-AuNRs@Anti-TRPV1 evidently improved physical activities and alleviated pain of destabilization of the medial meniscus (DMM)-induced OA mice. The study reveals Cit-AuNRs@Anti-TRPV1 under NIR irradiation protects chondrocytes from ferroptosis and attenuates OA progression, providing a potential therapeutic strategy for the treatment of OA.

Potential salivary and serum biomarkers for burning mouth syndrome and their relationship with anxiety/depression

Background/purpose

The pathophysiology of burning mouth syndrome (BMS), although considered a multifactorial etiology including psychological factors, is still not well understood. Hence, this study aimed to investigate the potential usage of salivary and serum biomarkers, including brain-derived neurotrophic factor (BDNF), interferon-gamma (IFN-γ), interleukin-1beta (IL-1β), interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor-alpha (TNF-α), in diagnosing BMS and their correlations with anxiety/depression.

Materials and methods

45 BMS patients and 14 healthy volunteers were enrolled. The patients were divided into BMS with anxiety/depression group and BMS without anxiety/depression group according to the scores of the Zung Self-rating Anxiety Scale (SAS) and Zung Self-rating Depression Scale (SDS). Additionally, concentrations of BDNF, IFN-γ, IL-1β, IL-6, IL-8, and TNF-α in saliva and those in serum among the patients and healthy volunteers were assessed by multiplex assay using Luminex 200TM system and Enzyme-linked immunosorbent assay (ELISA), respectively.

Results

Among all the serum biomarkers, only BDNF showed a statistically significant decrease in the patients than the healthy volunteers (P < 0.05). Regarding saliva biomarkers, BDNF, IL-1β, and IL-8 all exhibited a statistically significant increase in all the BMS patients versus the healthy volunteers (P < 0.05) but only BDNF was significantly different between patients with anxiety/depression and healthy individuals when considering anxiety/depression. Among BMS patients with anxiety/depression, saliva TNF-α had positive associations with other biomarkers including BDNF, IFN-γ, IL-1β, IL-6, and IL-8 (P < 0.05).

Conclusion

The increased concentration of saliva BDNF holds strong potential for diagnosing BMS and the elevated level of saliva TNF-α is crucial in identifying BMS patients with anxiety/depression.

PKM2 induces mitophagy through the AMPK-mTOR pathway promoting CSFV proliferation

Viruses exploit the host cell's energy metabolism system to support their replication. Mitochondria, known as the powerhouse of the cell, play a critical role in regulating cell survival and virus replication. Our prior research indicated that the classical swine fever virus (CSFV) alters mitochondrial dynamics and triggers glycolytic metabolic reprogramming. However, the role and mechanism of PKM2, a key regulatory enzyme of glycolytic metabolism, in CSFV replication remain unclear. In this study, we discovered that CSFV enhances PKM2 expression and utilizes PKM2 to inhibit pyruvate production. Using an affinity purification coupled mass spectrometry system, we successfully identified PKM as a novel interaction partner of the CSFV non-structural protein NS4A. Furthermore, we validated the interaction between PKM2 and both CSFV NS4A and NS5A through co-immunoprecipitation and confocal analysis. PKM2 was found to promote the expression of both NS4A and NS5A. Moreover, we observed that PKM2 induces mitophagy by activating the AMPK-mTOR signaling pathway, thereby facilitating CSFV proliferation. In summary, our data reveal a novel mechanism whereby PKM2, a metabolic enzyme, promotes CSFV proliferation by inducing mitophagy. These findings offer a new avenue for developing antiviral strategies.

IMPORTANCE

Viruses rely on the host cell's material-energy metabolic system for replication, inducing host metabolic disorders and subsequent immunosuppression-a major contributor to persistent viral infections. Classical swine fever virus (CSFV) is no exception. Classical swine fever is a severe acute infectious disease caused by CSFV, resulting in significant economic losses to the global pig industry. While the role of the metabolic enzyme PKM2 (pyruvate dehydrogenase) in the glycolytic pathway of tumor cells has been extensively studied, its involvement in viral infection remains relatively unknown. Our data unveil a new mechanism by which the metabolic enzyme PKM2 mediates CSFV infection, offering novel avenues for the development of antiviral strategies.

Low-intensity pulsed ultrasound delays the progression of osteoarthritis by regulating the YAP-RIPK1-NF-κB axis and influencing autophagy

BACKGROUND

Osteoarthritis (OA) is a degenerative disease characterized by chronic inflammation of the joint. As the disease progresses, patients will gradually develop symptoms such as pain, physical limitations and even disability. The risk factors for OA include genetics, gender, trauma, obesity, and age. Unfortunately, due to limited understanding of its pathological mechanism, there are currently no effective drugs or treatments to suspend the progression of osteoarthritis. In recent years, some studies found that low-intensity pulsed ultrasound (LIPUS) may have a positive effect on osteoarthritis. Nonetheless, the exact mechanism by which LIPUS affects osteoarthritis remains unknown. It is valuable to explore the specific mechanism of LIPUS in the treatment of OA.

METHODS

In this study, we validated the potential therapeutic effect of LIPUS on osteoarthritis by regulating the YAP-RIPK1-NF-κB axis at both cellular and animal levels. To verify the effect of YAP on OA, the expression of YAP was knocked down or overexpressed by siRNA and plasmid in chondrocytes and adeno-associated virus was injected into the knee joint of rats. The effect of LIPUS was investigated in inflammation chondrocytes induced by IL-1β and in the post-traumatic OA model.

RESULTS

In this study, we observed that YAP plays an important role in the development of osteoarthritis and knocking down of YAP significantly inhibited the inflammation and alleviated cartilage degeneration. We also demonstrated that the expression of YAP was increased in osteoarthritis chondrocytes and YAP could interact with RIPK1, thereby regulating the NF-κB signal pathway and influencing inflammation. Moreover, we also discovered that LIPUS decreased the expression of YAP by restoring the impaired autophagy capacity and inhibiting the binding between YAP and RIPK1, thereby delaying the progression of osteoarthritis. Animal experiment showed that LIPUS could inhibit cartilage degeneration and alleviate the progression of OA.

CONCLUSIONS

These results showed that LIPUS is effective in inhibiting inflammation and cartilage degeneration and alleviate the progression of OA. As a result, our results provide new insight of mechanism by which LIPUS delays the development of osteoarthritis, offering a novel therapeutic regimen for osteoarthritis.

Natural products in osteoarthritis treatment: bridging basic research to clinical applications

Osteoarthritis (OA) is the most prevalent degenerative musculoskeletal disease, severely impacting the function of patients and potentially leading to disability, especially among the elderly population. Natural products (NPs), obtained from components or metabolites of plants, animals, microorganisms etc., have gained significant attention as important conservative treatments for various diseases. Recently, NPs have been well studied in preclinical and clinical researches, showing promising potential in the treatment of OA. In this review, we summed up the main signaling pathways affected by NPs in OA treatment, including NF-κB, MAPKs, PI3K/AKT, SIRT1, and other pathways, which are related to inflammation, anabolism and catabolism, and cell death. In addition, we described the therapeutic effects of NPs in different OA animal models and the current clinical studies in OA patients. At last, we discussed the potential research directions including in-depth analysis of the mechanisms and new application strategies of NPs for the OA treatment, so as to promote the basic research and clinical transformation in the future. We hope that this review may allow us to get a better understanding about the potential bioeffects and mechanisms of NPs in OA therapy, and ultimately improve the effectiveness of NPs-based clinical conservative treatment for OA patients.

Evaluate the effects of low-intensity pulsed ultrasound on dental implant osseointegration under type II diabetes

Objective: The objective of this study is to assess the impact of low-intensity pulsed ultrasound (LIPUS) therapy on the peri-implant osteogenesis in a Type II diabetes mellitus (T2DM) rat model. Methods: A total of twenty male Sprague-Dawley (SD) rats were randomly allocated into four groups: Control group, T2DM group, Control-LIPUS group, and T2DM-LIPUS group. Implants were placed at the rats' bilateral maxillary first molar sites. The LIPUS treatment was carried out on the rats in Control-LIPUS group and T2DM-LIPUS group, immediately after the placement of the implants, over three consecutive weeks. Three weeks after implantation, the rats' maxillae were extracted for micro-CT, removal torque value (RTV), and histologic analysis. Results: Micro-CT analysis showed that T2DM rats experienced more bone loss around implant cervical margins compared with the non-T2DM rats, while the LIPUS treated T2DM rats showed similar bone heights to the non-T2DM rats. Bone-implant contact ratio (BIC) were lower in T2DM rats but significantly improved in the LIPUS treated T2DM rats. Bone formation parameters including bone volume fraction (BV/TV), trabecular thickness (Tb.Th), bone mineral density (BMD) and RTV were all positively influenced by LIPUS treatment. Histological staining further confirmed LIPUS's positive effects on peri-implant new bone formation in T2DM rats. Conclusion: As an effective and safe treatment in promoting osteogenesis, LIPUS has a great potential for T2DM patients to attain improved peri-implant osteogenesis. To confirm its clinical efficacy and to explore the underlying mechanism, further prospective cohort studies or randomized controlled trials are needed in the future.

A Novel Cargo Delivery System-AnCar-ExoLaIMTS Ameliorates Arthritis via Specifically Targeting Pro-Inflammatory Macrophages

Macrophages are heterogenic phagocytic cells that play distinct roles in physiological and pathological processes. Targeting different types of macrophages has shown potent therapeutic effects in many diseases. Although many approaches are developed to target anti-inflammatory macrophages, there are few researches on targeting pro-inflammatory macrophages, which is partially attributed to their non-s pecificity phagocytosis of extracellular substances. In this study, a novel recombinant protein is constructed that can be anchored on an exosome membrane with the purpose of targeting pro-inflammatory macrophages via antigen recognition, which is named AnCar-ExoLaIMTS . The data indicate that the phagocytosis efficiencies of pro-inflammatory macrophages for different AnCar-ExoLaIMTS show obvious differences. The AnCar-ExoLaIMTS3 has the best targeting ability for pro-inflammatory macrophages in vitro and in vivo. Mechanically, AnCar-ExoLaIMTS3 can specifically recognize the leucine-rich repeat domain of the TLR4 receptor, and then enter into pro-inflammatory macrophages via the TLR4-mediated receptor endocytosis pathway. Moreover, AnCar-ExoLaIMTS3 can efficiently deliver therapeutic cargo to pro-inflammatory macrophages and inhibit the synovial inflammatory response via downregulation of HIF-1α level, thus ameliorating the severity of arthritis in vivo. Collectively, the work established a novel gene/drug delivery system that can specifically target pro-inflammatory macrophages, which may be beneficial for the treatments of arthritis and other inflammatory diseases.

κ-Opioid receptor activation attenuates osteoarthritis synovitis by regulating macrophage polarization through the NF-κB pathway

Osteoarthritis (OA) is a prevalent and chronic joint disease that affects the aging population, causing pain and disability. Macrophages in synovium are important mediators of synovial inflammatory activity and pathological joint pain. Previous studies have demonstrated the significant involvement of κ-opioid receptor (KOR) in the regulation of pain and inflammation. Our study reveals a significant reduction in synovial KOR expression among patients and mice with OA. Here, we find that KOR activation effectively inhibits the expressions of the LPS-induced-inflammatory cytokines TNF-α and IL-6 by inhibiting macrophage M1 phenotype. Mechanistically, KOR activation effectively suppresses the proinflammatory factor secretion of macrophages by inhibiting the translocation of NF-κB into the nucleus. Our animal experiments reveal that activation of KOR effectively alleviates knee pain and prevents synovitis progression in OA mice. Consistently, KOR administration suppresses the expressions of M1 macrophage markers and the NF-κB pathway in the synovium of the knee. Collectively, our study suggests that targeting KOR may be a viable strategy for treating OA by inhibiting synovitis and improving joint pain in affected patients.

Glycolysis: an emerging regulator of osteoarthritis

Osteoarthritis (OA) has been a leading cause of disability in the elderly and there remains a lack of effective therapeutic approaches as the mechanisms of pathogenesis and progression have yet to be elucidated. As OA progresses, cellular metabolic profiles and energy production are altered, and emerging metabolic reprogramming highlights the importance of specific metabolic pathways in disease progression. As a crucial part of glucose metabolism, glycolysis bridges metabolic and inflammatory dysfunctions. Moreover, the glycolytic pathway is involved in different areas of metabolism and inflammation, and is associated with a variety of transcription factors. To date, it has not been fully elucidated whether the changes in the glycolytic pathway and its associated key enzymes are associated with the onset or progression of OA. This review summarizes the important role of glycolysis in mediating cellular metabolic reprogramming in OA and its role in inducing tissue inflammation and injury, with the aim of providing further insights into its pathological functions and proposing new targets for the treatment of OA.

Involvement of microglial P2X7 receptor in pain modulation

BACKGROUND

Pain is a rapid response mechanism that compels organisms to retreat from the harmful stimuli and triggers a repair response. Nonetheless, when pain persists for extended periods, it can lead to adverse changes into in the individual's brain, negatively impacting their emotional state and overall quality of life. Microglia, the resident immune cells in the central nervous system (CNS), play a pivotal role in regulating a variety of pain-related disorders. Specifically, recent studies have shed light on the central role that microglial purinergic ligand-gated ion channel 7 receptor (P2X7R) plays in regulating pain. In this respect, the P2X7R on microglial membranes represents a potential therapeutic target.

AIMS

To expound on the intricate link between microglial P2X7R and pain, offering insights into potential avenues for future research.

METHODS

We reviewed 140 literature and summarized the important role of microglial P2X7R in regulating pain, including the structure and function of P2X7R, the relationship between P2X7R and microglial polarization, P2X7R-related signaling pathways, and the effects of P2X7R antagonists on pain regulation.

RESULTS

P2X7R activation is related to M1 polarization of microglia, while suppressing P2X7R can transfer microglia from M1 into M2 phenotype. And targeting the P2X7R-mediated signaling pathways helps to explore new therapy for pain alleviation. P2X7R antagonists also hold potential for translational and clinical applications in pain management.

CONCLUSIONS

Microglial P2X7R holds promise as a potential novel pharmacological target for clinical treatments due to its distinctive structure, function, and the development of antagonists.

Efficacy of low-intensity pulsed ultrasound in the treatment of COVID-19 pneumonia

PURPOSE

As a public health emergency of international concern, coronavirus disease 2019 (COVID-19) still lacks specific antiviral drugs, and symptomatic treatment is currently the mainstay. The overactivated inflammatory response in COVID-19 patients is associated with a high risk of critical illness or even death. Low-intensity pulsed ultrasound (LIPUS) can mitigate inflammation and inhibit edema formation. We aimed to investigate the efficacy of LIPUS therapy for COVID-19 pneumonia.

MATERIALS AND METHODS

62 patients were randomly assigned to a treatment group (LIPUS treatment area - Group 1; self-control area - Group 2) and an external control group (Group 3). The primary outcomes were the volume absorption rate (VAR) and the area absorption rate (AAR) of lung inflammation in CT images.

RESULTS

After an average duration of treatment 7.2 days, there were significant differences in AAR and VAR between Group 1 and Group 2 (AAR 0.25 vs 0.12, p=0.013; VAR 0.35 vs 0.11, p=0.005), and between Group 1 and Group 3 (AAR 0.25 vs 0.11, p=0.047; VAR 0.35 vs 0.19, p=0.042). Neither AAR nor VAR was statistically different between Group 2 and Group 3. After treatment, C-reactive protein, interleukin-6, leukocyte, and fingertip arterial oxygen saturation (SaO2) improved in Group 1, while in Group 3 only fingertip SaO2 increased.

CONCLUSION

LIPUS therapy reduced lung inflammation and serum inflammatory factor levels in hospitalized COVID-19 patients, which might be a major advancement in COVID-19 pneumonia therapy.

LIPUS can promote osteogenesis of hPDLCs and inhibit the periodontal inflammatory response via TLR5

In this study, we isolated human periodontal ligament cells (hPDLCs) to find the optimal time of LIPUS stimulation and to explore how LIPUS affects inflammatory and osteogenic responses in hPDLCs in an inflammatory environment. The target molecules of LIPUS were identified by high-throughput sequencing. RT-qPCR and WB were used to detect how LIPUS affected the expression of related genes in TNFα-induced inflammation. The expression of ROS and inflammatory factors was detected by flow cytometry. Immunohistochemistry was used to further verify gene expression in rats. hPDLCs were isolated successfully. The optimal LIPUS stimulation condition was 45 mW/cm2 for 30 min and continued for 3 days, and this intensity significantly promoted the osteogenesis and mineralization of hPDLCs. LIPUS significantly inhibited the upregulation of IL-6 and ROS, increased the percentage of cells in the G2 phase, inhibited cell apoptosis, and inhibited the upregulation of TLR5 expression in an inflammatory environment. LIPUS can effectively restrain the inflammation and oxidative stress response of hPDLCs and promote osteogenesis in an inflammatory environment. LIPUS inhibited the periodontal inflammatory response through TLR5 in hPDLCs and dental pulp.

Discovery of anti-neuroinflammatory agents from 1,4,5,6-tetrahydrobenzo[2,3]oxepino[4,5-d]pyrimidin-2-amine derivatives by regulating microglia polarization

Neuroinflammation mediated by microglia activation leads to various neurodegenerative and neurological disorders. In order to develop more and better options for this disorders, a series of 3,4-dihydrobenzo[b]oxepin-5(2H)-one derivatives (BZPs, 6-19) and novel 1,4,5,6-tetrahydrobenzo[2,3]oxepino[4,5-d]pyrimidin-2-amine derivatives (BPMs, 20-33) were synthesized and screened the anti-neuroinflamamtion effects. 3,5-bis-trifluoromethylphenyl-substituted BPM 29 showed more potent anti-neuroinflammatory activity and no toxicity to BV2 microglia cells in vitro. 29 significantly reduced the number of M1 phenotype of microglia cells, but significantly increased the number of M2 phenotype of microglia cells in lipopolysaccharide (LPS)-induced BV2 microglia cells. 29 significantly reduced the secretion of inflammatory cytokines (IL-18, IL-1β, TNF-α), but increased the secretion of anti-inflammatory cytokines (IL-10) from LPS-induced BV2 microglia cells. Also, 29 inhibited the NOD-like receptor NLRP3 inflammasome formation, and down-regulated the expression of M2 isoform of pyruvate kinase in LPS-induced BV2 microglia cells. In vivo, 29 reduced the neuroinflammation in cuprizone-induced inflammatory and demyelinating mice by reducing the expression of inducible nitric-oxide synthase, but increased the expression of CD206. Taken together, 29 might be a prospective anti-neuroinflammatory compound for neuroinflammatory and demyelinating disease by alleviating microglia activation.

Anti-resorption role of low-intensity pulsed ultrasound (LIPUS) during large-scale bone reconstruction using porous titanium alloy scaffolds through inhibiting osteoclast differentiation

BACKGROUND

Ti6Al4V biomaterials combine with low-intensity pulsed ultrasound (LIPUS) has been reported with great bone regeneration capacity. It is important to better understand how LIPUS benefits bone microenvironment to seek for target of therapeutic medicine. Osteoclast differentiation plays a crucial role in bone resorption. Recent advances in molecular biology have revealed that N6-methyladenosine (m6A) RNA modifications can modulate biological processes, but their role in bone biology, particularly in osteoclast differentiation, remains unclear. We aim to understand how LIPUS regulates bone microenvironment especially osteoclast formation during bone regeneration to provide new therapeutic options for preventing and delaying bone resorption, thus with better bone regeneration efficiency.

RESULTS

1. LIPUS promoted bone ingrowth and bone maturity while inhibiting osteoclast formation within Ti6Al4V scaffolds in large-scale bone defect model. 2. LIPUS was found to inhibit osteoclast differentiation by decreasing the overall expression of osteoclast markers in vitro. 3. LIPUS decreases RNA m6A-modification level through upregulating FTO expression during osteoclast differentiation during. 4. Inhibiting FTO expression and function leads to less inhibition during osteoclast differentiation.

CONCLUSION

LIPUS suppresses osteoclast differentiation during bone regeneration through reducing m6A modification of osteoclastic RNAs by up regulating FTO expression.

Integrated single-cell and bulk RNA sequencing analysis identified pyroptosis-related signature for diagnosis and prognosis in osteoarthritis

Osteoarthritis (OA), a degenerative disease of the joints, has one of the highest disability rates worldwide. This study investigates the role of pyroptosis-related genes in osteoarthritis and their expression in different chondrocyte subtypes at the individual cell level. Using OA-related datasets for single-cell RNA sequencing and RNA-seq, the study identified PRDEGs and DEGs and conducted Cox regression analysis to identify independent prognostic factors for OA. CASP6, NOD1, and PYCARD were found to be prognostic factors. Combined Weighted Gene Correlation Network Analysis with PPI network, a total of 15 hub genes related to pyroptosis were involved in the notch and oxidative phosphorylation pathways, which could serve as biomarkers for the diagnosis and prognosis of OA patients. The study also explored the heterogeneity of chondrocytes between OA and normal samples, identifying 19 single-cell subpopulation marker genes that were significantly different among 7 chondrocyte cell clusters. AGT, CTSD, CYBC, and THYS1 were expressed differentially among different cell subpopulations, which were associated with cartilage development and metabolism. These findings provide valuable insights into the molecular mechanisms underlying OA and could facilitate the development of new therapeutic strategies for this debilitating disease.

Sijunzi Decoction Targets IL1B and TNF to Reduce Neutrophil Extracellular Traps (NETs) in Ulcerative Colitis: Evidence from Silicon Prediction and Experiment Validation

Purpose

This study was conducted to explore the mechanism of Sijunzi Decoction (SJZ) in the treatment of ulcerative colitis (UC).

Methods

The study aimed to investigate the active components and targets of SJZ in the treatment of UC by screening databases such as TCMSP, GeneCards, OMIM, Distinct, TTD, and Drugbank. An online Venn tool, Cytoscape 3.7.2, and Autodock Tools were used to analyze the components and targets. The study also used a mouse model of UC to further investigate the effects of SJZ. HE staining, immunofluorescence, ELISA, qPCR, and Western blot were used to detect various indices.

Results

Eighty-three active components and 112 action targets were identified from SJZ, including 67 targets for treating UC-related NETs. The five core targets identified were AKT1, JUN, IL1B, PTGS2, and TNF, and molecular docking studies indicated that the five targets were well-docked with ginsenoside Rh2, isoflavones, and formononetin. Animal experiments demonstrated that SJZ could alleviate various parameters such as weight, colon length, spleen index, disease activity index, and intestinal pathology of the UC mice. Immunofluorescence and Western blot showed that SJZ could reduce the expression of IL1B and TNF in intestinal neutrophils while increasing the expression of Occludin. Cellular immunofluorescence suggests that SJZ can reduce the expression of TNF and IL1B in NETs. The qPCR results also suggested that SJZ could inhibit TNF signal. Furthermore, ELISA results suggested that SJZ could inhibit the expression of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6) while promoting the expression of anti-inflammatory cytokines (IL-10, IL-37, TGF-β).

Conclusion

SJZ treats UC by reducing the content of intestinal NETs, with primary targets on the NETs being IL1B and TNFand suppress TNF signal. The practical components of SJZ may be ginsenoside Rh2, isoflavones, and formononetin.

Low-intensity pulsed ultrasound of different intensities differently affects myocardial ischemia/reperfusion injury by modulating cardiac oxidative stress and inflammatory reaction

Introduction

The prevalence of ischemic heart disease has reached pandemic levels worldwide. Early revascularization is currently the most effective therapy for ischemic heart diseases but paradoxically induces myocardial ischemia/reperfusion (MI/R) injury. Cardiac inflammatory reaction and oxidative stress are primarily involved in the pathology of MI/R injury. Low-intensity pulsed ultrasound (LIPUS) has been demonstrated to reduce cell injury by protecting against inflammatory reaction and oxidative stress in many diseases, including cardiovascular diseases, but rarely on MI/R injury.

Methods

This study was designed to clarify whether LIPUS alleviates MI/R injury by alleviating inflammatory reaction and oxidative stress. Simultaneously, we have also tried to confirm which intensity of the LIPUS might be more suitable to ameliorate the MI/R injury, as well as to clarify the signaling mechanisms. MI/R and simulated ischemia/reperfusion (SI/R) were respectively induced in Sprague Dawley rats and human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs). LIPUS treatment, biochemical measurements, cell death assay, estimation of cardiac oxidative stress and inflammatory reaction, and protein detections by western blotting were performed according to the protocol.

Results

In our study, both in vivo and in vitro, LIPUS of 0.1 W/cm2 (LIPUS0.1) and 0.5 W/cm2 (LIPUS0.5) make no significant difference in the cardiomyocytes under normoxic condition. Under the hypoxic condition, MI/R injury, inflammatory reaction, and oxidative stress were partially ameliorated by LIPUS0.5 but were significantly aggravated by LIPUS of 2.5 W/cm2 (LIPUS2.5) both in vivo and in vitro. The activation of the apoptosis signal-regulating kinase 1 (ASK1)/c-Jun N-terminal kinase (JNK) pathway in cardiomyocytes with MI/R injury was partly rectified LIPUS0.5 both in vivo and in vitro.

Conclusion

Our study firstly demonstrated that LIPUS of different intensities differently affects MI/R injury by regulating cardiac inflammatory reaction and oxidative stress. Modulations on the ASK1/JNK pathway are the signaling mechanism by which LIPUS0.5 exerts cardioprotective effects. LIPUS0.5 is promising for clinical translation in protecting against MI/R injury. This will be great welfare for patients suffering from MI/R injury.

Paroxetine Attenuates Chondrocyte Pyroptosis and Inhibits Osteoclast Formation by Inhibiting NF-κB Pathway Activation to Delay Osteoarthritis Progression

Background

Osteoarthritis (OA), a common chronic joint disease, is characterized by cartilage degeneration and subchondral bone reconstruction. NF-κB signaling pathway-activated inflammation and NLRP3-induced pyroptosis play essential roles in the development of OA. In this study, we examine whether paroxetine can inhibit pyroptosis and reduce osteoclast formation, thereby delaying the destruction of knee joints.

Methods

We employed high-density cultures, along with quantitative polymerase chain reactions and Western blotting techniques, to investigate the effects of paroxetine on extracellular matrix synthesis and degradation. The expression levels of NF-κB and pyroptosis-related signaling pathway proteins were examined by Western blotting and immunofluorescence. Furthermore, the impact of paroxetine on RANKL-induced osteoclast formation was evaluated through TRAP staining and F-actin ring fluorescence detection. To investigate the role of paroxetine in vivo, we constructed a mouse model with destabilization of the medial meniscus (DMM) surgery. Safranin O-Fast Green staining, Hematoxylin-Eosin staining, and immunohistochemistry were conducted to observe the extent of knee joint cartilage deformation. In addition, TRAP staining was used to observe the formation of osteoclasts in the subchondral bone.

Results

In the in vitro experiments with ATDC5, paroxetine treatment attenuated IL-1β-induced activation of the pyroptosis-related pathway and suppressed extracellular matrix catabolism by inhibiting the NF-kB signaling pathway. In addition, paroxetine treatment decreased the expression of RANKL-induced osteoclast marker genes and reduced osteoclast formation. In animal experiments conducted in vivo, mice treated with paroxetine exhibited thicker knee cartilage with a smoother surface compared to the DMM group. Additionally, the formation of osteoclasts in the subchondral bone was reduced in the paroxetine-treated mice. Further analysis revealed that paroxetine treatment played a role in preserving the balance of the extracellular matrix and delaying knee joint degeneration.

Conclusion

Paroxetine can inhibit pyroptosis and reduce osteoclast formation via inhibiting the NF-κB signaling pathway, suggesting that it may have therapeutic effects in patients with OA.

Research Progress of Low-Intensity Pulsed Ultrasound in the Repair of Peripheral Nerve Injury

Peripheral nerve injury (PNI) is a common disease that has profound impact on the health of patients, but has poor prognosis. The gold standard for the treatment of peripheral nerve defects is autologous nerve grafting; notwithstanding, due to the extremely high requirement for surgeons and medical facilities, there is great interest in developing better treatment strategies for PNI. Low-intensity pulsed ultrasound (LIPUS) is a noninterventional stimulation method characterized by low-intensity pulsed waves. It has good therapeutic effect on fractures, inflammation, soft tissue regeneration, and nerve regulation, and can participate in PNI repair from multiple perspectives. This review concentrates on the effects and mechanisms of LIPUS in the repair of PNI from the perspective of LIPUS stimulation of neural cells and stem cells, modulation of neurotrophic factors, signaling pathways, proinflammatory cytokines, and nerve-related molecules. In addition, the effects of LIPUS on nerve conduits are reviewed, as nerve conduits are expected to be a successful alternative treatment for PNI with the development of tissue engineering. Overall, the application advantages and prospects of LIPUS in the repair of PNI are highlighted by summarizing the effects of LIPUS on seed cells, neurotrophic factors, and nerve conduits for neural tissue engineering.

Targeting macrophagic PIM-1 alleviates osteoarthritis by inhibiting NLRP3 inflammasome activation via suppressing mitochondrial ROS/Cl- efflux signaling pathway

BACKGROUND

Osteoarthritis (OA), in which macrophage-driven synovitis is considered closely related to cartilage destruction and could occur at any stage, is an inflammatory arthritis. However, there are no effective targets to cure the progression of OA. The NOD-, LRR-,and pyrin domain-containing protein 3 (NLRP3) inflammasome in synovial macrophages participates in the pathological inflammatory process and treatment strategies targeting it are considered to be an effective approach for OA. PIM-1 kinase, as a downstream effector of many cytokine signaling pathways, plays a pro-inflammatory role in inflammatory disease.

METHODS

In this study, we evaluated the expression of the PIM-1 and the infiltration of synovial macrophages in the human OA synovium. The effects and mechanism of PIM-1 were investigated in mice and human macrophages stimulated by lipopolysaccharide (LPS) and different agonists such as nigericin, ATP, Monosodium urate (MSU), and Aluminum salt (Alum). The protective effects on chondrocytes were assessed by a modified co-culture system induced by macrophage condition medium (CM). The therapeutic effect in vivo was confirmed by the medial meniscus (DMM)-induced OA in mice.

RESULTS

The expression of PIM-1 was increased in the human OA synovium which was accompanied by the infiltration of synovial macrophages. In vitro experiments, suppression of PIM-1 by SMI-4a, a specific inhibitor, rapidly inhibited the NLRP3 inflammasome activation in mice and human macrophages and gasdermin-D (GSDME)-mediated pyroptosis. Furthermore, PIM-1 inhibition specifically blocked the apoptosis-associated speck-like protein containing a CARD (ASC) oligomerization in the assembly stage. Mechanistically, PIM-1 inhibition alleviated the mitochondrial reactive oxygen species (ROS)/chloride intracellular channel proteins (CLICs)-dependent Cl- efflux signaling pathway, which eventually resulted in the blockade of the ASC oligomerization and NLRP3 inflammasome activation. Furthermore, PIM-1 suppression showed chondroprotective effects in the modified co-culture system. Finally, SMI-4a significantly suppressed the expression of PIM-1 in the synovium and reduced the synovitis scores and the Osteoarthritis Research Society International (OARSI) score in the DMM-induced OA model.

CONCLUSIONS

Therefore, PIM-1 represented a new class of promising targets as a treatment of OA to target these mechanisms in macrophages and widened the road to therapeutic strategies for OA.

Efficacy of low-intensity pulsed ultrasound for the treatment of viral pneumonia: study protocol for a randomized controlled trial

BACKGROUND

Viral pneumonia has always been a problem faced by clinicians because of its insidious onset, strong infectivity, and lack of effective drugs. Patients with advanced age or underlying diseases may experience more severe symptoms and are prone to severe ventilation dysfunction. Reducing pulmonary inflammation and improving clinical symptoms is the focus of current treatment. Low-intensity pulsed ultrasound (LIPUS) can mitigate inflammation and inhibit edema formation. We aimed to investigate the efficacy of therapeutic LIPUS in improving lung inflammation in hospitalized patients with viral pneumonia.

METHODS

Sixty eligible participants with clinically confirmed viral pneumonia will be assigned to either (1) intervention group (LIPUS stimulus), (2) control group (null stimulus), or (3) self-control group (LIPUS stimulated areas versus non-stimulated areas). The primary outcome will be the difference in the extent of absorption and dissipation of lung inflammation on computed tomography. Secondary outcomes include changes in lung inflammation on ultrasonography images, pulmonary function, blood gas analysis, fingertip arterial oxygen saturation, serum inflammatory factor levels, the sputum excretion volume, time to the disappearance of pulmonary rales, pneumonia status score, and course of pneumonia. Adverse events will be recorded.

DISCUSSION

This study is the first clinical study of the efficacy of therapeutic LIPUS in the treatment of viral pneumonia. Given that the current clinical recovery mainly depends on the body's self-limiting and conventional symptomatic treatment, LIPUS, as a new therapy method, might be a major advance in the treatment of viral pneumonia.

TRIAL REGISTRATION

ChiCTR2200059550 Chinese Clinical Trial Registry, May 3, 2022.

Lapachol treats non-alcoholic fatty liver disease by modulating the M1 polarization of Kupffer cells via PKM2

AIM

This study investigated the mechanism of action of lapachol (LAP) against non-alcoholic fatty liver disease (NAFLD).

METHODS

Primary Kupffer cells (KCs) of rats were used for in-vitro experiments. The proportion of M1 cells was assayed by flow cytometry, the levels of M1 inflammatory markers were determined by enzyme-linked immunosorbent assay (ELISA) combined with real-time quantitative fluorescence PCR (RT-qPCR), the expression of p-PKM2 was detected by Western-Blotting. A SD rat model of NAFLD was established with high-fat diet. Following LAP intervention, the changes in blood glucose/lipid, insulin resistance and liver function were detected, and the hepatic histopathologic changes were examined by histological staining.

RESULTS

The results showed that LAP could inhibit the M1 polarization of KCs, lower the levels of inflammatory cytokines, and suppress the activation of PKM2. The effect of LAP could be counteracted after using PKM2 inhibitor PKM2-IN-1 or knocking out PKM2. Small molecule docking revealed that LAP could inhibit the phosphorylation process of PKM2 by binding to ARG-246, the phosphorylation site of PKM2. In rat experiments, LAP could ameliorate the liver function and lipid metabolism of NAFLD rats, and inhibit the hepatic histopathologic changes.

CONCLUSION

Our study found that LAP can inhibit the phosphorylation of PKM2 by binding to PKM2-ARG-246, thereby regulating the M1 polarization of KCs and inhibiting the inflammatory response of liver tissues to treat NAFLD. LAP has potential as a novel pharmaceutical for treating NAFLD.

Low-intensity pulsed ultrasound reduces lymphedema by regulating macrophage polarization and enhancing microcirculation

Background: Conventional therapies reduce lymphedema but do not cure it because they cannot modulate the pathophysiology of secondary lymphedema. Lymphedema is characterized by inflammation. We hypothesized that low-intensity pulsed ultrasound (LIPUS) treatment could reduce lymphedema by enhancing anti-inflammatory macrophage polarization and microcirculation. Methods: The rat tail secondary lymphedema model was established through the surgical ligation of lymphatic vessels. The rats were randomly divided into the normal, lymphedema, and LIPUS treatment groups. The LIPUS treatment (3 min daily) was applied 3 days after establishing the model. The total treatment period was 28 days. Swelling, fibro adipose deposition, and inflammation of the rat tail were evaluated by HE staining and Masson's staining. The photoacoustic imaging system and laser Doppler flowmetry were used to monitor microcirculation changes in rat tails after LIPUS treatment. The cell inflammation model was activated with lipopolysaccharides. Flow cytometry and fluorescence staining were used to observe the dynamic process of macrophage polarization. Results: After 28 days of treatment, compared with the lymphedema group, the tail circumference and subcutaneous tissue thickness of rats in the LIPUS group were decreased by 30%, the proportion of collagen fibers and the lymphatic vessel cross-sectional area was decreased, and tail blood flow was increased significantly. Cellular experiments revealed a decrease in CD86⁺ macrophages (M1) after LIPUS treatment. Conclusion: The transition of M1 macrophage and the promotion of microcirculation could be responsible for the beneficial effect of LIPUS on lymphedema.

SENP3 deletion promotes M2 macrophage polarization and accelerates wound healing through smad6/IκB/p65 signaling pathway

Macrophages preferentially polarize to the anti-inflammatory M2 subtype in response to alterations in the wound microenvironment. SUMO-specific protease 3 (SENP3), a SUMO-specific protease, has been proven to regulate inflammation in macrophages by deSUMOylating substrate proteins, but its contribution to wound healing is poorly defined. Here, we report that SENP3 deletion promotes M2 macrophage polarization and accelerates wound healing in macrophage-specific SENP3 knockout mice. Notably, it affects wound healing through the suppression of inflammation and promotion of angiogenesis and collagen remodeling. Mechanistically, we identified that SENP3 knockout facilitates M2 polarization through the Smad6/IκB/p65 signaling pathway. SENP3 knockout elevated the expression of Smad6 and IκB. Moreover, Smad6 silencing enhanced the expression of p-p65 and proinflammatory cytokines while inhibiting the level of IκB. Our study revealed the essential role of SENP3 in M2 polarization and wound healing, which offers a theoretical basis for further research and a therapeutic strategy for wound healing.

ARIH1 inhibits influenza A virus replication and facilitates RIG-I dependent immune signaling by interacting with SQSTM1/p62

BACKGROUND

Multiple host factors are involved in modulating type I interferon expression induced by viruses; however, the mechanism is not fully elucidated. Influenza A virus infection causes severe respiratory symptoms and triggers a series of signaling cascades and host innate immune responses, including interferon production. The co-IP/MS technology was used to screen several antiviral factors in the early stage. Among these factors, ariadne-1 homolog (ARIH1) caught our attention.

METHODS

Western blot assay was performed to detect the level of proteins and software ImageJ was used to analyze the band intensities. Polymerase activity assay was conducted to evaluate the polymerase activity of influenza A virus. Tissue culture infective dose (TCID₅₀) assay was performed to measure influenza A virus titers, and quantitative RT-PCR assay was applied to test the mRNA level of IFN-β, ISG56, and CXCL10. Luciferase reporter assay was used to confirm the target of ARIH1 in RIG-I signaling. Immunoprecipitation assay was performed to detect the interaction and the ubiquitination of the proteins. All data were analyzed by biostatistical methods and presented as means ± standard deviation from three independent experiments. Statistical significance was determined using two-tailed student's t test. A P value of less than 0.05 was considered statistically significant, and a P value of less than 0.01 was considered highly significant (ns, P ≥ 0.05; *, P < 0.05; and **, P < 0.01).

RESULTS

We found that ARIH1, a member of E3 ubiquitin ligases, enhanced cellular antiviral responses. Subsequent study showed that ARIH1 was up-regulated during influenza A virus infection. Further analysis showed that ARIH1 enhanced IFN-β and downstream gene expression by affecting the degradation of RIG-I through the SQSTM1/p62 signaling pathway.

CONCLUSION

This newly revealed mechanism shows that cellular response increases of ARIH1 and promotes IFN-β expression to boost host survival during viral infection.

Optimal low-intensity pulsed ultrasound stimulation for promoting anti-inflammatory effects in macrophages

In this paper, we stimulated M1-like macrophages (obtained from U937 cells) with low-intensity pulsed ultrasound (LIPUS) to lower pro-inflammatory cytokine production. A systematic screening of different frequencies, intensities, duty cycles, and exposure times was performed. The optimal stimulation conditions leading to a marked decrease in the release of inflammatory cytokines were determined to be 38 kHz, 250 mW/cm², 20%, and 90 min, respectively. Using these parameters, we verified that up to 72 h LIPUS did not affect cell viability, resulting in an increase in metabolic activity and in a reduction of reactive oxygen species (ROS) production. Moreover, we found that two mechanosensitive ion channels (PIEZO1 and TRPV1) were involved in the LIPUS-mediated cytokine release modulation. We also assessed the role of the nuclear factor κB (NF-κB) signaling pathway and observed an enhancement of actin polymerization. Finally, transcriptomic data suggested that the bioeffects of LIPUS treatment occur through the modulation of p38 MAPK signaling pathway.

Low intensity pulsed ultrasound reduces liver inflammation caused by fatigue exercise

Low-intensity pulsed ultrasound (LIPUS) has been shown to have many benefits, such as inhibiting inflammation, stimulating cell proliferation and differentiation, promoting angiogenesis, and so on. So, can exercise fatigue induced liver inflammation be effectively relieved by LIPUS? If possible, what is the possible mechanism? This study first investigated the effect of different intensity exercise on liver inflammation. Rats were divided into three groups: normal control group, exercise fatigue group, and aerobic exercise group. The results showed that aerobic exercise increases both anti-inflammatory factors and pro-inflammatory factors, while fatigue exercise decreases anti-inflammatory factors and increases pro-inflammatory factors, leading to severe liver injury and fibrosis. Then, we investigated the therapeutic effect of LIPUS on liver inflammation caused by exercise fatigue. Starting from the 6th week, the liver was irradiated with LIPUS of 80 mW/cm² for 20 min/d after daily exercise for 7 weeks. The results showed that LIPUS significantly decreased liver injury and fibrosis, significantly up-regulated the expression of STAT6, IL-13, and its receptors IL-13Rα1, and down regulated the expression of NF-κBp65 in exercise fatigue rats. These results indicate that LIPUS can reduce fatigue-induced liver inflammation, and the mechanism is related to the regulation of the IL-13/STAT6/NF-κBp65 pathway.

Autophagy in the pathogenesis and therapeutic potential of post-traumatic osteoarthritis

Autophagy, as a fundamental mechanism for cellular homeostasis, is generally involved in the occurrence and progression of various diseases. Osteoarthritis (OA) is the most common musculoskeletal disease that often leads to pain, disability and economic loss in patients. Post-traumatic OA (PTOA) is a subtype of OA, accounting for >12% of the overall burden of OA. PTOA is often caused by joint injuries including anterior cruciate ligament rupture, meniscus tear and intra-articular fracture. Although a variety of methods have been developed to treat acute joint injury, the current measures have limited success in effectively reducing the incidence and delaying the progression of PTOA. Therefore, the pathogenesis and intervention strategy of PTOA need further study. In the past decade, the roles and mechanisms of autophagy in PTOA have aroused great interest in the field. It was revealed that autophagy could maintain the homeostasis of chondrocytes, reduce joint inflammatory level, prevent chondrocyte death and matrix degradation, which accordingly improved joint symptoms and delayed the progression of PTOA. Moreover, many strategies that target PTOA have been revealed to promote autophagy. In this review,  we summarize the roles and mechanisms of autophagy in PTOA and the current strategies for PTOA treatment that depend on autophagy regulation, which may be beneficial for PTOA patients in the future.

Sirtuin 1 activator alleviated lethal inflammatory injury via promotion of autophagic degradation of pyruvate kinase M2

Upregulation of pyruvate kinase M2 (PKM2) is critical for the orchestration of metabolism and inflammation in critical illness, while autophagic degradation is a recently revealed mechanism that counter-regulates PKM2. Accumulating evidence suggests that sirtuin 1 (SIRT1) function as a crucial regulator in autophagy. The present study investigated whether SIRT1 activator would downregulate PKM2 in lethal endotoxemia via promotion of its autophagic degradation. The results indicated that lethal dose of lipopolysaccharide (LPS) exposure decreased the level of SIRT1. Treatment with SRT2104, a SIRT1 activator, reversed LPS-induced downregulation of LC3B-II and upregulation of p62, which was associated with reduced level of PKM2. Activation of autophagy by rapamycin also resulted in reduction of PKM2. The decline of PKM2 in SRT2104-treated mice was accompanied with compromised inflammatory response, alleviated lung injury, suppressed elevation of blood urea nitrogen (BUN) and brain natriuretic peptide (BNP), and improved survival of the experimental animals. In addition, co-administration of 3-methyladenine, an autophagy inhibitor, or Bafilomycin A1, a lysosome inhibitor, abolished the suppressive effects of SRT2104 on PKM2 abundance, inflammatory response and multiple organ injury. Therefore, promotion of autophagic degradation of PKM2 might be a novel mechanism underlying the anti-inflammatory benefits of SIRT1 activator.

LIPUS as a potential strategy for periodontitis treatment: A review of the mechanisms

Periodontitis is a chronic inflammatory condition triggered by oral bacteria. A sustained inflammatory state in periodontitis could eventually destroy the alveolar bone. The key objective of periodontal therapy is to terminate the inflammatory process and reconstruct the periodontal tissues. The traditional Guided tissue regeneration (GTR) procedure has unstable results due to multiple factors such as the inflammatory environment, the immune response caused by the implant, and the operator's technique. Low-intensity pulsed ultrasound (LIPUS), as acoustic energy, transmits the mechanical signals to the target tissue to provide non-invasive physical stimulation. LIPUS has positive effects in promoting bone regeneration, soft-tissue regeneration, inflammation inhibition, and neuromodulation. LIPUS can maintain and regenerate alveolar bone during an inflammatory state by suppressing the expression of inflammatory factors. LIPUS also affects the cellular behavior of periodontal ligament cells (PDLCs), thereby protecting the regenerative potential of bone tissue in an inflammatory state. However, the underlying mechanisms of the LIPUS therapy are still yet to be summarized. The goal of this review is to outline the potential cellular and molecular mechanisms of periodontitis-related LIPUS therapy, as well as to explain how LIPUS manages to transmit mechanical stimulation into the signaling pathway to achieve inflammatory control and periodontal bone regeneration.

Low-intensity pulsed ultrasound promotes skeletal muscle regeneration via modulating the inflammatory immune microenvironment

Background: Low-intensity pulsed ultrasound (LIPUS, a form of mechanical stimulation) can promote skeletal muscle functional repair, but a lack of mechanistic understanding of its relationship and tissue regeneration limits progress in this field. We investigated the hypothesis that specific energy levels of LIPUS mediates skeletal muscle regeneration by modulating the inflammatory microenvironment. Methods: To address these gaps, LIPUS irritation was applied in vivo for 5 min at two different intensities (30mW/cm² and 60mW/cm²) in next 7 consecutive days, and the treatment begun at 24h after air drop-induced contusion injury. In vitro experiments, LIPUS irritation was applied at three different intensities (30mW/cm², 45mW/cm², and 60mW/cm²) for 2 times 24h after introduction of LPS in RAW264.7. Then, we comprehensively assessed the functional and histological parameters of skeletal muscle injury in mice and the phenotype shifting in macrophages through molecular biological methods and immunofluorescence analysis both in vivo and in vitro. Results: We reported that LIPUS therapy at intensity of 60mW/cm² exhibited the most significant differences in functional recovery of contusion-injured muscle in mice. The comprehensive functional tests and histological analysis in vivo indirectly and directly proved the effectiveness of LIPUS for muscle recovery. Through biological methods and immunofluorescence analysis both in vivo and in vitro, we found that this improvement was attributable in part to the clearance of M1 macrophages populations and the increase in M2 subtypes with the change of macrophage-mediated factors. Depletion of macrophages in vivo eliminated the therapeutic effects of LIPUS, indicating that improvement in muscle function was the result of M2-shifted macrophage polarization. Moreover, the M2-inducing effects of LIPUS were proved partially through the WNT pathway by upregulating FZD5 expression and enhancing β-catenin nuclear translocation in macrophages both in vitro and in vivo. The inhibition and augment of WNT pathway in vitro further verified our results. Conclusion: LIPUS at intensity of 60mW/cm² could significantly promoted skeletal muscle regeneration through shifting macrophage phenotype from M1 to M2. The ability of LIPUS to direct macrophage polarization may be a beneficial target in the clinical treatment of many injuries and inflammatory diseases.

The therapeutic effects of low-intensity pulsed ultrasound in musculoskeletal soft tissue injuries: Focusing on the molecular mechanism

Musculoskeletal soft tissue injuries are very common and usually occur during both sporting and everyday activities. The intervention of adjuvant therapies to promote tissue regeneration is of great importance to improving people's quality of life and extending their productive lives. Though many studies have focused on the positive results and effectiveness of the LIPUS on soft tissue, the molecular mechanisms standing behind LIPUS effects are much less explored and reported, especially the intracellular signaling pathways. We incorporated all research on LIPUS in soft tissue diseases since 2005 and summarized studies that uncovered the intracellular molecular mechanism. This review will also provide the latest evidence-based research progress in this field and suggest research directions for future experiments.

A Simple Nomogram for Predicting Osteoarthritis Severity in Patients with Knee Osteoarthritis

Objective

To explore the influencing factors of knee osteoarthritis (KOA) severity and establish a KOA nomogram model.

Methods

Inpatient data collected in the Department of Joint Surgery, Chengde Medical University Affiliated Hospital from January 2020 to January 2022 were used as the training cohort. Patients with knee osteoarthritis who were admitted to the Third Hospital of Hebei Medical University from February 2022 to May 2022 were taken as the external validation group of the model. In the training group, the least absolute shrinkage and selection operator (LASSO) method was used to screen the factors of KOA severity to determine the best prediction index. Then, after combining the significant factors from the LASSO and multivariate logistic regressions, a prediction model was established. All potential prediction factors were included in the KOA severity prediction model, and the corresponding nomogram was drawn. The consistency index (C-index), area under the receiver operating characteristic (ROC) curve (AUC), GiViTi calibration band, net classification improvement (NRI) index, and integrated discrimination improvement (IDI) index evaluation of a model predicted KOA severity. Decision curve analysis (DCA) and clinical influence curves were used to study the model's potential clinical value. The validation group also used the above evaluation indexes to measure the diagnostic efficiency of the model. Spearman correlation was used to investigate the relationship between nomogram-related markers and osteoarthritis severity.

Results

The total sample included 572 patients with knee osteoarthritis, including 400 patients in the training cohort and 172 patients in the validation cohort. The nomogram's predictive factors were age, pulse, absolute value of lymphocytes, mean corpuscular haemoglobin concentration (MCHC), and blood urea nitrogen (BUN). The C-index and AUC of the model were 0.802. The GiViTi calibration band (P = 0.065), NRI (0.091), and IDI (0.033) showed that the modified model can distinguish between severe KOA and nonsevere KOA. DCA showed that the KOA severity nomogram has clinical application value with threshold probabilities between 0.01 and 0.78. The external verification results also show the stability and diagnosis of the model. Age, pulse, MCHC, and BUN are correlated with osteoarthritis severity.

Conclusions

A nomogram model for predicting KOA severity was established for the first time that can visually identify patients with severe KOA and is novel for indirectly evaluating KOA severity by nonimaging means.

HK2: a potential regulator of osteoarthritis via glycolytic and non-glycolytic pathways

Osteoarthritis (OA) is an age-related chronic degenerative joint disease where the main characteristics include progressive degeneration of cartilage, varying degrees of synovitis, and periarticular osteogenesis. However, the underlying factors involved in OA pathogenesis remain elusive which has resulted in poor clinical treatment effect. Recently, glucose metabolism changes provide a new perspective on the pathogenesis of OA. Under the stimulation of external environment, the metabolic pathway of chondrocytes tends to change from oxidative phosphorylation (OXPHOS) to aerobic glycolysis. Previous studies have demonstrated that glycolysis of synovial tissue is increased in OA. The hexokinase (HK) is the first rate limiting enzyme in aerobic glycolysis, participating and catalyzing the main pathway of glucose utilization. An isoform of HKs, HK2 is considered to be a key regulator of glucose metabolism, promotes the transformation of glycolysis from OXPHOS to aerobic glycolysis. Moreover, the expression level of HK2 in OA synovial tissue (FLS) was higher than that in control group, which indicated the potential therapeutic effect of HK2 in OA. However, there is no summary to help us understand the potential therapeutic role of glucose metabolism in OA. Therefore, this review focuses on the properties of HK2 and existing research concerning HK2 and OA. We also highlight the potential role and mechanism of HK2 in OA.

Low-intensity pulsed ultrasound promotes periodontal regeneration in a beagle model of furcation involvement

Objective: To evaluate the regeneration potential of periodontitis tissue treated by low-intensity pulsed ultrasound (LIPUS) combined with the guided tissue regeneration (GTR) technique in a beagle model of furcation involvement (FI).

Background: Achieving predictable regeneration remains a clinical challenge for periodontitis tissue due to the compromised regenerative potential caused by chronic inflammation stimulation. LIPUS, an FDA-approved therapy for long bone fracture and non-unions, has been demonstrated effective in the in vitro attenuation of inflammation-induced dysfunction of periodontal ligament stem cells (PDLSCs), the key cells contributing to periodontal regeneration. However, the in vivo effect of LIPUS on periodontitis tissue is rarely reported.

Methods: A beagle model of FI was established, and the experimental teeth were randomly assigned into three groups: control group, GTR group, and GTR+LIPUS group. Radiographic examinations were performed, and clinical periodontal parameters were recorded to reflect the periodontal condition of different groups. Histological analyses using H&amp;E and Masson’s staining were conducted to evaluate the periodontal tissue regeneration.

Results: LIPUS could enhance new periodontal bone formation and bone matrix maturity in FI after GTR treatment. Moreover, clinical assessment and histomorphometric analyses revealed less inflammatory infiltration and superior vascularization within bone grafts in the LIPUS treatment group, indicating the anti-inflammatory and pro-angiogenic effects of LIPUS in FI.

Conclusion: Our investigation on a large animal model demonstrated that LIPUS is a promising adjunctive approach for the regeneration of periodontitis tissue, paving a new avenue for LIPUS application in the field of periodontal regenerative medicine.

Research progress on the role of PKM2 in the immune response

Pyruvate kinase (PK) is a key enzyme that catalyzes the dephosphorylation of phosphoenolpyruvate (PEP) into pyruvate, and is responsible for the production of ATP during glycolysis. As another important isozyme of PK, pyruvate kinase M2 (PKM2) exists in cells with high levels of nucleic acid synthesis, such as normal proliferating cells (e.g., lymphocytes and intestinal epithelial cells), embryonic cells, adult stem cells, and tumor cells. With further research, PKM2, as an important regulator of cellular pathophysiological activity, has attracted increasing attention in the process of autoimmune response and inflammatory. In this re]view, we examine the contribution of PKM2 to the human immune response. Further studies on the immune mechanisms of PKM2 are expected to provide more new ideas and drug targets for immunotherapy of inflammatory and autoimmune diseases, guiding drug development and disease treatment.

Extracellular vesicles derived from human umbilical cord mesenchymal stem cells alleviate osteoarthritis of the knee in mice model by interacting with METTL3 to reduce m6A of NLRP3 in macrophage

Background

Osteoarthritis (OA) is a prevalent degenerative joint disease that not only significantly impairs the quality of life of middle-aged and elderly individuals but also imposes a significant financial burden on patients and society. Due to their significant biological properties, extracellular vesicles (EVs) have steadily received great attention in OA treatment. This study aimed to investigate the influence of EVs on chondrocyte proliferation, migration, and apoptosis and their protective efficacy against OA in mice.

Methods

The protective impact of EVs derived from human umbilical cord mesenchymal stem cells (hucMSCs-EVs) on OA in mice was investigated by establishing a mouse OA model by surgically destabilizing the medial meniscus (DMM). Human chondrocytes were isolated from the cartilage of patients undergoing total knee arthroplasty (TKA) and cultured with THP-1 cells to mimic the in vivo inflammatory environment. Levels of inflammatory factors were then determined in different groups, and the impacts of EVs on chondrocyte proliferation, migration, apoptosis, and cartilage extracellular matrix (ECM) metabolism were explored. N6-methyladenosine (m6A) level of mRNA and methyltransferase-like 3 (METTL3) protein expression in the cells was also measured in addition to microRNA analysis to elucidate the molecular mechanism of exosomal therapy.

Results

The results indicated that hucMSCs-EVs slowed OA progression, decreased osteophyte production, increased COL2A1 and Aggrecan expression, and inhibited ADAMTS5 and MMP13 overexpression in the knee joint of mice via decreasing pro-inflammatory factor secretion. The in vitro cell line analysis revealed that EVs enhanced chondrocyte proliferation and migration while inhibiting apoptosis. METTL3 is responsible for these protective effects. Further investigations revealed that EVs decreased the m6A level of NLRP3 mRNA following miR-1208 targeted binding to METTL3, resulting in decreased inflammatory factor release and preventing OA progression.

Conclusion

This study concluded that hucMSCs-EVs inhibited the secretion of pro-inflammatory factors and the degradation of cartilage ECM after lowering the m6A level of NLRP3 mRNA with miR-1208 targeting combined with METTL3, thereby alleviating OA progression in mice and providing a novel therapy for clinical OA treatment.

Capsaicin ameliorates inflammation in a TRPV1-independent mechanism by inhibiting PKM2-LDHA-mediated Warburg effect in sepsis

Sepsis is a systemic inflammatory response syndrome with high mortality and morbidity worldwide. In this study, we demonstrate that capsaicin not only suppresses inflammation in lipopolysaccharide (LPS)-induced macrophages, but also effectively inhibits endotoxemia or sepsis-related inflammation in vivo. We have designed and synthesized a series of capsaicin-based probes, which permit the profiling of the target proteins of capsaicin using activity-based protein profiling (ABPP). Among the identified protein targets, we discover that capsaicin directly binds to and inhibits PKM2 and LDHA, and further suppresses the Warburg effect in inflammatory macrophages. Moreover, capsaicin targets COX-2 and downregulates its expression in vivo and in vitro. Taken together, the present findings indicate that capsaicin alleviates the inflammation response and the Warburg effect in a TRPV1-independent manner by targeting PKM2-LDHA and COX-2 in sepsis. Thus, capsaicin may function as a novel agent for sepsis and inflammation treatment.

Single-Cell Profiles of Age-Related Osteoarthritis Uncover Underlying Heterogeneity Associated With Disease Progression

Objective: Osteoarthritis (OA) is the most common chronic degenerative joint disease, which represents the leading cause of age-related disability. Here, this study aimed to depict the intercellular heterogeneity of OA synovial tissues.

Methods: Single-cell RNA sequencing (scRNA-seq) data were preprocessed and quality controlled by the Seurat package. Cell cluster was presented and cell types were annotated based on the mRNA expression of corresponding marker genes by the SingleR package. Cell-cell communication was assessed among different cell types. After integrating the GSE55235 and GSE55457 datasets, differentially expressed genes were identified between OA and normal synovial tissues. Then, differentially expressed marker genes were overlapped and their biological functions were analyzed.

Results: Totally, five immune cell subpopulations were annotated in OA synovial tissues including macrophages, dendritic cells, T cells, monocytes and B cells. Pseudo-time analysis revealed the underlying evolution process in the inflammatory microenvironment of OA synovial tissue. There was close crosstalk between five cell types according to the ligand-receptor network. The genetic heterogeneity was investigated between OA and normal synovial tissues. Furthermore, functional annotation analysis showed the intercellular heterogeneity across immune cells in OA synovial tissues.

Conclusion: This study offered insights into the heterogeneity of OA, which provided in-depth understanding of the transcriptomic diversities within synovial tissue. This transcriptional heterogeneity may improve our understanding on OA pathogenesis and provide potential molecular therapeutic targets for OA.

Low-intensity pulsed ultrasound therapy suppresses coronary adventitial inflammatory changes and hyperconstricting responses after coronary stent implantation in pigs in vivo

Backgrounds

We demonstrated that coronary adventitial inflammation plays important roles in the pathogenesis of drug-eluting stent (DES)-induced coronary hyperconstricting responses in pigs in vivo. However, no therapy is yet available to treat coronary adventitial inflammation. We thus developed the low-intensity pulsed ultrasound (LIPUS) therapy that ameliorates myocardial ischemia by enhancing angiogenesis.

Aims

We aimed to examine whether our LIPUS therapy suppresses DES-induced coronary hyperconstricting responses in pigs in vivo, and if so, what mechanisms are involved.

Methods

Sixteen normal male pigs were randomly assigned to the LIPUS or the sham therapy groups after DES implantation into the left anterior descending (LAD) coronary artery. In the LIPUS group, LIPUS (32 cycles, 193 mW/cm²) was applied to the heart at 3 different levels (segments proximal and distal to the stent edges and middle of the stent) for 20 min at each level for every other day for 2 weeks. The sham therapy group was treated in the same manner but without LIPUS. At 4 weeks after stent implantation, we performed coronary angiography, followed by immunohistological analysis.

Results

Coronary vasoconstricting responses to serotonin in LAD at DES edges were significantly suppressed in the LIPUS group compared with the sham group. Furthermore, lymph transport speed in vivo was significantly faster in the LIPUS group than in the sham group. Histological analysis at DES edges showed that inflammatory changes and Rho-kinase activity were significantly suppressed in the LIPUS group, associated with eNOS up-regulation and enhanced lymph-angiogenesis.

Conclusions

These results suggest that our non-invasive LIPUS therapy is useful to treat coronary functional abnormalities caused by coronary adventitial inflammation, indicating its potential for the novel and safe therapeutic approach of coronary artery disease.

Low-intensity pulsed ultrasound inhibits fibroblast-like synoviocyte proliferation and reduces synovial fibrosis by regulating Wnt/β-catenin signaling

OBJECTIVE

Synovial fibrosis is a characteristic symptom of osteoarthritis (OA), which is closely associated with joint pain and stiffness. Previous studies have reported that low-intensity pulsed ultrasound (LIPUS) can alleviate cartilage degradation in OA. However, the functions and mechanisms of LIPUS in OA synovial fibrosis are still unknown.

METHODS

The destabilization of the medial meniscus (DMM) mouse model of OA was established in C57 male mice and fibroblast-like synoviocytes (FLS) were isolated from synovial tissue of OA patients. The knee joint diameter, Masson's trichrome (MT) and Hematoxylin-eosin (HE) staining were used to evaluate synovial fibrosis and hyperplasia. The Immunohistochemistry (IHC) staining was performed to detected the expression of synovial fibrosis makers and the activation of Wnt/β-catenin signaling in vivo. FLS were treated with TGF-β1 to serve as an in vitro model of synovial fibrosis, Wnt3a was used to activate the Wnt/β-catenin signaling in cells. Cell proliferation was detected by using EdU assay, cell viability was performed by CCK8 assay. The protein levels of α-SMA, CTGF, Col Ⅰ, β-catenin, active β-catenin, c-Myc and cyclin D1 were examined by western blot and immunofluorescence staining.

RESULTS

Two weeks after the LIPUS treatment, the synovial fibrosis, synovial hyperplasia and synoviocyte proliferation in the DMM model were significantly decreased. In vitro, LIPUS directly inhibited the TGF-β1-induced fibrotic response and proliferation of FLS. Meanwhile, LIPUS suppressed Wnt/β-catenin signaling in the synovium of DMM mice and cultured FLS. More importantly, we found that the synovial fibrosis makers, Wnt/β-catenin pathway downstream proteins and FLS proliferation were significantly decreased in Wnt3a-stimulated FLS following LIPUS treatment.

CONCLUSIONS

Our results present a novel role of LIPUS in OA-related synovial fibrosis, which is associated with its ability to repress Wnt/β-catenin signaling in FLS.

THE TRANSLATIONAL POTENTIAL OF THIS ARTICLE

This study provides new insight into the clinical application of LIPUS as a therapeutic option to manage synovial fibrosis in OA.

Glycitin Suppresses Cartilage Destruction of Osteoarthritis in Mice

Osteoarthritis (OA), a chronic joint disease, is characterized by cartilage surface erosion, subchondral bone rebuilding, and formation of osteophytes. To date, the nosogenesis and underlying mechanisms of OA have not yet been elucidated. However, it is widely accepted that TNF-α is a crucial cytokine in the development of OA. Glycitin, a natural isoflavone extracted from legumes, affects physiological reactions and pathological responses. Recently, the anti-inflammatory effect of glycitin has been reported. However, the function of glycitin in cartilage degeneration in OA remains to be investigated. In the current study, primary murine chondrocytes were isolated and stimulated by TNF-α to evaluate the anti-inflammatory effects and protective function of glycitin in chondrocytes. In vivo, the ACLT mouse model, a frequently-used OA model, was used to further examine the therapeutic role of glycitin in cartilage degeneration and inflammation in OA. Consequently, glycitin functions were examined both in vivo and in vitro. Moreover, the underlying mechanism of action of glycitin was investigated and was found to involve the NF-κB signaling pathway. Collectively, this study suggests that glycitin can be potentially used for the treatment of joint degenerative diseases, including OA.