Tectorigenin Alleviates Inflammation, Apoptosis, and Ossification in Rat Tendon-Derived Stem Cells via Modulating NF-Kappa B and MAPK Pathways

Malvidin attenuates trauma-induced heterotopic ossification of tendon in rats by targeting Rheb for degradation via the ubiquitin-proteasome pathway

The pathogenesis of trauma-induced heterotopic ossification (HO) in the tendon remains unclear, posing a challenging hurdle in treatment. Recognizing inflammation as the root cause of HO, anti-inflammatory agents hold promise for its management. Malvidin (MA), possessing anti-inflammatory properties, emerges as a potential agent to impede HO progression. This study aimed to investigate the effect of MA in treating trauma-induced HO and unravel its underlying mechanisms. Herein, the effectiveness of MA in preventing HO formation was assessed through local injection in a rat model. The potential mechanism underlying MA's treatment was investigated in the tendon-resident progenitor cells of tendon-derived stem cells (TDSCs), exploring its pathway in HO formation. The findings demonstrated that MA effectively hindered the osteogenic differentiation of TDSCs by inhibiting the mTORC1 signalling pathway, consequently impeding the progression of trauma-induced HO of Achilles tendon in rats. Specifically, MA facilitated the degradation of Rheb through the K48-linked ubiquitination-proteasome pathway by modulating USP4 and intercepted the interaction between Rheb and the mTORC1 complex, thus inhibiting the mTORC1 signalling pathway. Hence, MA presents itself as a promising candidate for treating trauma-induced HO in the Achilles tendon, acting by targeting Rheb for degradation through the ubiquitin-proteasome pathway.

Global research trends and hotspots on tendon-derived stem cell: a bibliometric visualization study

Purpose: This study was aimed to examine the global research status and current research hotspots in the field of tendon stem cells. Methods: Bibliometric methods were employed to retrieve relevant data from the Web of Science Core Collection (WOSCC) database. Additionally, Citespace, Vosviewer, SCImago, and Graphad Prism were utilized to analyze the publication status in this field, identify the current research hotspots, and present a mini-review. Results: The most active countries in this field were China and the United States. Notable authors contributing significantly to this research included Lui Pauline Po Yee, Tang Kanglai, Zhang Jianying, Yin Zi, and Chen Xiao, predominantly affiliated with institutions such as the Hong Kong Hospital Authority, Third Military Medical University, University of Pittsburgh, and Zhejiang University. The most commonly published journals in this field were Stem Cells International, Journal of Orthopedic Research, and Stem Cell Research and Therapy. Moreover, the current research hotspots primarily revolved around scaffolds, molecular mechanisms, and inflammation regulation. Conclusion: Tendon stem cells hold significant potential as seed cells for tendon tissue engineering and offer promising avenues for further research Scaffolds, molecular mechanisms and inflammation regulation are currently research hotspots in this field.

Inhibiting JAK1, not NF-κB, reverses the effect of pro-inflammatory cytokines on engineered human ligament function

The role of inflammation in chronic tendon/ligament injury is hotly debated. There is less debate about inflammation following acute injury. To better understand the effect of acute inflammation, in this study we developed a multi-cytokine model of inflammatory tendinitis. The combined treatment with TNF-α, IL-1β, and IL-6, at dosages well below what are routinely used in vitro, decreased the mechanical properties and collagen content of engineered human ligaments. Treatment with this cytokine mixture resulted in an increase in phospho-NF-κB and MMP-1, did not affect procollagen production, and decreased STAT3 phosphorylation relative to controls. Using this more physiologically relevant model of acute inflammation, we inhibited NF-κB or JAK1 signaling in an attempt to reverse the negative effects of the cytokine mixture. Surprisingly, NF-κB inhibition led to an even greater decrease in mechanical function and collagen content. By contrast, inhibiting JAK1 led to an increase in mechanical properties, collagen content and thermal stability concomitant with a decrease in MMP-1. Our results suggest that inhibition of JAK1, not NF-κB, reverses the negative effects of pro-inflammatory cytokines on collagen content and mechanics in engineered human ligaments.

The investigation of interaction and chaperon-like activity of α-synuclein as a protein in pathophysiology of Parkinson's disease upon direct interaction with tectorigenin

Analyzing the therapeutic potential of a therapeutic biomolecule requires an understanding of how it may interact with proteins and modify their corresponding functions. α-Synuclein is a protein which is widely involved in the pathogenesis of Parkinson's disease (PD) and shows chaperon-like activity. We have selected tectorigenin, a most common methoxyisoflavone extracted from plants, among therapeutic bioactive molecules that are documented to have different therapeutic effects. Herein, we aimed to explore how tectorigenin interacts with α-synuclein in vitro by mimicking the physiological environment. Spectroscopic as well as theoretical studies including molecular docking simulation, were used to examine the effects of tectorigenin on the conformation and dynamics of α-synuclein. It was shown that tectorigenin is able to quench the protein emission spectra relied on a mixed static-dynamic quenching mechanism. Furthermore, it was displayed that tectorigenin binding to α-synuclein leads to microenvironmental changes in the tertiary structure of protein, however the protein's secondary structure was almost unchanged. It was also deduced that tectorigenin results in thermal stability of α-synuclein structure, evidenced by less perturbation of α-synuclein secondary structure following elevation of temperature in the presence of tectorigenin relative to that of free form. Molecular docking simulation demonstrated that non-covalent reactions, mainly hydrogen bonds, had a key role in the interaction and stabilization of α-synuclein in the presence of tectorigenin. Moreover, chaperon-like activity of α-synuclein was improved in the presence of tectorigenin against two model proteins, βL-crystallin and catalase. The findings showed that tectorigenin can lead to stabilization of α-synuclein, which may be used as a therapeutic agent in prevention of neurodegenerative diseases.

Circ_0005736 promotes tenogenic differentiation of tendon-derived stem cells through the miR-636/MAPK1 axis

BACKGROUND

Tendon-derived stem cells (TDSCs) are one of stem cells characterized by greater clonogenicity, tenogenesis, and proliferation capacity. Circ_0005736 has been shown to be decreased in Rotator cuff tendinopathy. Here, we investigated the function and relationship of circ_0005736 in TDSC tenogenic differentiation.

METHODS

Transforming growth factor β1 (TGF-β1) was used to induce the tenogenic differentiation in TDSC. Cell proliferation, invasion and migration were evaluated by Cell Counting Kit-8, 5-Ethynyl-2'-deoxyuridine, transwell, and wound healing assays, respectively. The detection of the levels of genes and proteins was performed by qRT-PCR and Western blot. The binding between miR-636 and circ_0005736 or MAPK1 (Mitogen-Activated Protein Kinase 1) was verified using dual-luciferase reporter assay and RIP assays.

RESULTS

TGF-β1 induced tenogenic differentiation by enhancing the production of tendon-specific markers and TDSC proliferation, invasion and migration. TGF-β1 treatment promoted circ_0005736 expression, knockdown of circ_0005736 abolished TGF-β1-induced tenogenic differentiation in TDSCs. Mechanistically, circ_0005736 acted as a sponge for miR-636 to up-regulate the expression of MAPK1, which was confirmed to be a target of miR-636 in TDSCs. Further rescue assays showed that inhibition of miR-636 could rescue circ_0005736 knockdown-induced suppression on TGF-β1-caused tenogenic differentiation in TDSCs. Moreover, forced expression of miR-636 abolished TGF-β1-caused tenogenic differentiation in TDSCs, which was rescued by MAPK1 up-regulation.

CONCLUSION

Circ_0005736 enhanced TGF-β1-induced tenogenic differentiation in TDSCs via increasing the production of tendon-specific markers and TDSC proliferation, invasion and migration through miR-636/MAPK1 axis.

Animal model for tendinopathy

Background

Tendinopathy is a common motor system disease that leads to pain and reduced function. Despite its prevalence, our mechanistic understanding is incomplete, leading to limited efficacy of treatment options. Animal models contribute significantly to our understanding of tendinopathy and some therapeutic options. However, the inadequacies of animal models are also evident, largely due to differences in anatomical structure and the complexity of human tendinopathy. Different animal models reproduce different aspects of human tendinopathy and are therefore suitable for different scenarios. This review aims to summarize the existing animal models of tendinopathy and to determine the situations in which each model is appropriate for use, including exploring disease mechanisms and evaluating therapeutic effects.

Methods

We reviewed relevant literature in the PubMed database from January 2000 to December 2022 using the specific terms ((tendinopathy) OR (tendinitis)) AND (model) AND ((mice) OR (rat) OR (rabbit) OR (lapin) OR (dog) OR (canine) OR (sheep) OR (goat) OR (horse) OR (equine) OR (pig) OR (swine) OR (primate)). This review summarized different methods for establishing animal models of tendinopathy and classified them according to the pathogenesis they simulate. We then discussed the advantages and disadvantages of each model, and based on this, identified the situations in which each model was suitable for application.

Results

For studies that aim to study the pathophysiology of tendinopathy, naturally occurring models, treadmill models, subacromial impingement models and metabolic models are ideal. They are closest to the natural process of tendinopathy in humans. For studies that aim to evaluate the efficacy of possible treatments, the selection should be made according to the pathogenesis simulated by the modeling method. Existing tendinopathy models can be classified into six types according to the pathogenesis they simulate: extracellular matrix synthesis-decomposition imbalance, inflammation, oxidative stress, metabolic disorder, traumatism and mechanical load.

Conclusions

The critical factor affecting the translational value of research results is whether the selected model is matched with the research purpose. There is no single optimal model for inducing tendinopathy, and researchers must select the model that is most appropriate for the study they are conducting.

The translational potential of this article

The critical factor affecting the translational value of research results is whether the animal model used is compatible with the research purpose. This paper provides a rationale and practical guide for the establishment and selection of animal models of tendinopathy, which is helpful to improve the clinical transformation ability of existing models and develop new models.

Tectorigenin: A Review of Its Sources, Pharmacology, Toxicity, and Pharmacokinetics

Tectorigenin is a well-known natural flavonoid aglycone and an active component that exists in numerous plants. Growing evidence suggests that tectorigenin has multiple pharmacological effects, such as anticancer, antidiabetic, hepatoprotective, anti-inflammatory, antioxidative, antimicrobial, cardioprotective, and neuroprotective. These pharmacological properties provide the basis for the treatment of many kinds of illnesses, including several types of cancer, diabetes, hepatic fibrosis, osteoarthritis, Alzheimer's disease, etc. The purpose of this paper is to provide a comprehensive summary and review of the sources, extraction and synthesis, pharmacological effects, toxicity, pharmacokinetics, and delivery strategy aspects of tectorigenin. Tectorigenin may exert certain cytotoxicity, which is related to the administration time and concentration. Pharmacokinetic studies have demonstrated that the main metabolic pathways in rats for tectorigenin are glucuronidation, sulfation, demethylation and methoxylation, but that it exhibits poor bioavailability. From our perspective, further research on tectorigenin should cover: exploring the pharmacological targets and mechanisms of action; finding an appropriate concentration to balance pharmacological effects and toxicity; attempting diversified delivery strategies to improve the bioavailability; and structural modification to obtain tectorigenin derivatives with higher pharmacological activity.

Therapeutic Potential of Exosomes in Tendon and Tendon-Bone Healing: A Systematic Review of Preclinical Studies

Exosomes have been proven to play a positive role in tendon and tendon-bone healing. Here, we systematically review the literature to evaluate the efficacy of exosomes in tendon and tendon-bone healing. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a systematic and comprehensive review of the literature was performed on 21 January 2023. The electronic databases searched included Medline (through PubMed), Web of Science, Embase, Scopus, Cochrane Library and Ovid. In the end, a total of 1794 articles were systematically reviewed. Furthermore, a "snowball" search was also carried out. Finally, forty-six studies were included for analysis, with the total sample size being 1481 rats, 416 mice, 330 rabbits, 48 dogs, and 12 sheep. In these studies, exosomes promoted tendon and tendon-bone healing and displayed improved histological, biomechanical and morphological outcomes. Some studies also suggested the mechanism of exosomes in promoting tendon and tendon-bone healing, mainly through the following aspects: (1) suppressing inflammatory response and regulating macrophage polarization; (2) regulating gene expression, reshaping cell microenvironment and reconstructing extracellular matrix; (3) promoting angiogenesis. The risk of bias in the included studies was low on the whole. This systematic review provides evidence of the positive effect of exosomes on tendon and tendon-bone healing in preclinical studies. The unclear-to-low risk of bias highlights the significance of standardization of outcome reporting. It should be noted that the most suitable source, isolation methods, concentration and administration frequency of exosomes are still unknown. Additionally, few studies have used large animals as subjects. Further studies may be required on comparing the safety and efficacy of different treatment parameters in large animal models, which would be conducive to the design of clinical trials.

Integrative single-cell RNA and ATAC sequencing reveals that the FOXO1-PRDX2-TNF axis regulates tendinopathy

Introduction

Tendinopathy, the most common form of chronic tendon disorder, leads to persistent tendon pain and loss of function. Profiling the heterogeneous cellular composition in the tendon microenvironment helps to elucidate rational molecular mechanisms of tendinopathy.

Methods and results

In this study, through a multi-modal analysis, a single-cell RNA- and ATAC-seq integrated tendinopathy landscape was generated for the first time. We found that a specific cell subpopulation with low PRDX2 expression exhibited a higher level of inflammation, lower proliferation and migration ability, which not only promoted tendon injury but also led to microenvironment deterioration. Mechanistically, a motif enrichment analysis of chromatin accessibility showed that FOXO1 was an upstream regulator of PRDX2 transcription, and we confirmed that functional blockade of FOXO1 activity induced PRDX2 silencing. The TNF signaling pathway was significantly activated in the PRDX2-low group, and TNF inhibition effectively restored diseased cell degradation.

Discussion

We revealed an essential role of diseased cells in tendinopathy and proposed the FOXO1-PRDX2-TNF axis is a potential regulatory mechanism for the treatment of tendinopathy.

LncRNA AC108925 promotes osteoblast differentiation of tendon-derived stem cells by targeting miR-146a-3p

It has been reported that tendon-derived stem cells(TDSCs) conduce to the ostosis in tendon diseases, and the molecular mechanism needs to be discussed. To investigate the function and mechanism of LncRNA in tendinopathy. Tendon of tendinopathy patients and health controls were obtained, and sequencing analysis have been performed to detect the significantly expressed genes and non-coding RNAs. Moreover, to further discuss LncRNA AC108925 in tendinopathy, tendinopathy animal models have been established, and the expression of LncRNA AC108925 expression was examined by RT-qPCR methods. Furthermore, hTDSCs have been treated by osteogenic medium, and the modulating function of LncRNA AC108925 on the osteoblast differentiation of hTDSCs have been examined. Sequencing analysis showed that AC108925 a dramatically elevated LncRNA, and results of animal and cells studies confirmed the finding. Knockdown AC108925 inhibited the osteogenic differentiation of osteogenic medium treated TDSCs by decreasing the expression of osteogenic markers. Furthermore, miR-146a-3p is a target of AC108925 in TDSCs, and miR-146a-3p is a negative modulator of osteogenic differentiation of hTDSCs by inhibiting the effects of AC108925 shRNA on osteogenic differentiation of hTDSCs. AC108925 can regulate the osteogenic differentiation of hTDSCs via regulating the miR-146a-3p. Targeting the AC108925/miR-146a-3p axis might be a latent way to treat tendinopathy.

Fullerenol inhibits tendinopathy by alleviating inflammation

Tendinopathy is a common disease in orthopaedics, seriously affecting tendon functions. However, the effects of non-surgical treatment on tendinopathy are not satisfactory and surgical treatments possibly impair the function of tendons. Biomaterial fullerenol has been proved to show good anti-inflammatory effects on various inflammatory diseases. For in vitro experiments, primary rat tendon cells (TCs) were treated by interleukin-1 beta (IL-1β) combined with aqueous fullerenol (5, 1, 0.3 μg/mL). Then inflammatory factors, tendon-related markers, migration and signaling pathways were detected. For in vivo experiments, rat tendinopathy model was constructed by local injection of collagenase into Achilles tendons of rats and fullerenol (0.5, 1 mg/mL) was locally injected 7 days after collagenase injection. Inflammatory factors and tendon-related markers were also investigated. Fullerenol with good water-solubility showed excellent biocompatibility with TCs. Fullerenol could increase expression of tendon-related factors (Collagen I and tenascin C) and decrease expression of inflammatory factors (matrix metalloproteinases-3, MMP-3, and MMP-13) and reactive oxygen species (ROS) level. Simultaneously, fullerenol slowed the migration of TCs and inhibited activation of Mitogen-activated protein kinase (MAPK) signaling pathway. Fullerenol also attenuated tendinopathy in vivo, including reduction of fiber disorders, decrease of inflammatory factors and increase of tendon markers. In summary, fullerenol is a promising biomaterial that can be used to treat tendinopathy.

Targeting Senescent Tendon Stem/Progenitor Cells to Prevent or Treat Age-Related Tendon Disorders

Age-related tendon disorder, a primary motor system disease, is characterized by biological changes in the tendon tissue due to senescence and seriously affects the quality of life of the elderly. The pathogenesis of this disease is not well-understood. Tendon stem/progenitor cells (TSPCs) exhibit multi-differentiation capacity. These cells are important cellular components of the tendon because of their roles in tendon tissue homeostasis, remodeling, and repair. Previous studies revealed alterations in the biological characteristics and tenogenic differentiation potential of TSPCs in senescent tendon tissue, in turn contributing to insufficient differentiation of TSPCs into tenocytes. Poor tendon repair can result in age-related tendinopathies. Therefore, targeting of senescent TSPCs may restore the tenogenic differentiation potential of these cells and achieve homeostasis of the tendon tissue to prevent or treat age-related tendinopathy. In this review, we summarize the biological characteristics of TSPCs and histopathological changes in age-related tendinopathy, as well as the potential mechanisms through which TSPCs contribute to senescence. This information may promote further exploration of innovative treatment strategies to rescue TSPCs from senescence.

Regulating Macrophages through Immunomodulatory Biomaterials Is a Promising Strategy for Promoting Tendon-Bone Healing

The tendon-to-bone interface is a special structure connecting the tendon and bone and is crucial for mechanical load transfer between dissimilar tissues. After an injury, fibrous scar tissues replace the native tendon-to-bone interface, creating a weak spot that needs to endure extra loading, significantly decreasing the mechanical properties of the motor system. Macrophages play a critical role in tendon-bone healing and can be divided into various phenotypes, according to their inducing stimuli and function. During the early stages of tendon-bone healing, M1 macrophages are predominant, while during the later stages, M2 macrophages replace the M1 macrophages. The two macrophage phenotypes play a significant, yet distinct, role in tendon-bone healing. Growing evidence shows that regulating the macrophage phenotypes is able to promote tendon-bone healing. This review aims to summarize the impact of different macrophages on tendon-bone healing and the current immunomodulatory biomaterials for regulating macrophages, which are used to promote tendon-bone healing. Although macrophages are a promising target for tendon-bone healing, the challenges and limitations of macrophages in tendon-bone healing research are discussed, along with directions for further research.

Neratinib Exerts Dual Effects on Cartilage Degradation and Osteoclast Production in Osteoarthritis by Inhibiting the Activation of the MAPK/NF-κB Signaling Pathways

Osteoarthritis (OA) is a degenerative disease caused by the progressive destruction of cartilage and subchondral bone. [1] Studies have shown that by inhibiting the degradation of cartilage cells and the loss of subchondral bone, OA can be prevented and treated. Neratinib, as a small molecule compound with anti-inflammatory and anti-tumor properties, is a very effective inhibitor of IL-1β-induced chondrocyte inflammation and anabolic metabolism. By investigating the effect of neratinib in ATDC5 chondrocytes, the study finds that neratinib reduces inflammation by inhibiting the MAPK and NF-κB signaling pathways, and at the same time reduces pyrolysis (indicated by the results of reverse transcription quantitative PCR and western blotting). For anabolic metabolism, after high-density cell culture, IL-1β-induced catalytic changes and degradation of the extracellular matrix were evaluated by toluidine blue staining. Since osteoclasts are key participants in the process of subchondral bone remodeling in OA, we also studied the effect of neratinib on the maturation of osteoclasts. The results showed that neratinib also acts as an anti-osteoclast agent in vitro. By inhibiting the NF-κB and MAPK pathways, it reduces the expression of osteoclast-related genes, thereby inhibiting RANKL-induced osteoclastogenesis. The results of in vivo animal experiments supported the conclusions from the experiments in vitro. Neratinib inhibited both the destruction of medial meniscus induced cartilage degradation and osteoclast formation, which proves that neratinib has a dual effect, protecting cartilage and inhibiting osteoclast formation. These results indicate that neratinib can be a brand-new latent strategy for the treatment of OA.

UGT1A1 and UGT1A9 Are Responsible for Phase II Metabolism of Tectorigenin and Irigenin In Vitro

Tectorigenin and irigenin are biologically active isoflavones of Belamcanda chinensis (L.) DC. Previous studies indicated that both compounds could be metabolized in vivo; however, the kinetic parameters of enzymes involved in the metabolization of tectorigenin and irigenin have not been identified. The aim of this study was to investigate UGTs involved in the glucuronidation of tectorigenin and irigenin and determine enzyme kinetic parameters using pooled human liver microsomes (HLMs) and recombinant UGTs. Glucuronides of tectorigenin and irigenin were identified using high-performance liquid chromatography (HPLC) coupled with mass spectrometry and quantified by HPLC using a response factor method. The results showed that tectorigenin and irigenin were modified by glucuronidation in HLMs. One metabolite of tectorigenin (M) and two metabolites of irigenin (M1 and M2) were detected. Chemical inhibition and recombinant enzyme experiments revealed that several enzymes could catalyze tectorigenin and irigenin glucuronidation. Among them, UGT1A1 and UGT1A9 were the primary enzymes for both tectorigenin and irigenin; however, the former mostly produced irigenin glucuronide M1, while the latter mostly produced irigenin glucuronide M2. These findings suggest that UGT1A1 and UGT1A9 were the primary isoforms metabolizing tectorigenin and irigenin in HLMs, which could be involved in drug–drug interactions and, therefore, should be monitored in clinical practice.

Efficacy and Safety of Ganduqing Granules in Treating the Common Cold: A Multicenter, Randomized, Double-Blind, Placebo-Controlled Trial

Background

There is no clear evidence-based medicine that points to the most effective drug treatments for the common cold. In view of its ability to relieve symptoms and shorten the disease course, as well as its minimal side effects, traditional Chinese medicine (TCM) has been widely used to treat the common cold. However, there is a lack of strong evidence to support the clinical efficacy of TCM. This study aimed to evaluate the efficacy and safety of Ganduqing granules in the treatment of the common cold based on the network pharmacology analysis.

Methods

In this multicenter, randomized, double-blind, placebo-controlled trial, 60 eligible subjects will be randomly assigned to either the intervention group or the placebo group. The intervention group will be treated with Ganduqing granules, while the placebo group will be treated with placebo. After 5 days of intervention, the efficacy and safety of Ganduqing granules in the treatment of the common cold will be observed. The primary outcome is the time to clearance of all symptoms. The secondary outcomes included the levels of IL-6, TNF-α, SOD, and MDA in the peripheral blood, time to disappearance of primary symptoms and secondary symptoms, clinical symptom remission rate, and change in TCM syndrome score.

Results

Sixty participants completed the study. Ganduqing granules showed a greater effect on the time to clearance of all symptoms (P < 0.0001), nasal discharge (P=0.0124), fatigue and lack of strength (P=0.0138), dryness of the pharynx (P < 0.0001), pharyngalgia or dysphagia (P < 0.0001), and expectoration (P < 0.0431) compared with the placebo group. Participants in the intervention group had a greater decrease of IL-6 levels compared with the placebo group (P < 0.007); similar results were observed for the SOD (P < 0.033). However, the change in TNF-α and MDA levels in the intervention group was not significantly different from the placebo group. In addition, participants in the intervention group had a greater decrease of TCM syndrome score compared with the placebo group (P < 0.040).

Conclusion

Ganduqing granules could improve common cold symptoms, shorten the disease course, attenuated inflammation and oxidative stress, and provided objective evidence for the efficacy and safety of a Chinese herbal medicine in treating the common cold.

Friedelin Alleviates the Pathogenesis of Collagenase-Induced Tendinopathy in Mice by Promoting the Selective Autophagic Degradation of p65

With the development of an aging population, tendinopathy has become a common musculoskeletal disease in the elderly with a high recurrence rate and no curative treatment. The inflammation mediated by NF-κB signaling plays an important role in tendon senescence and degeneration. Friedelin (FR) is a triterpenoid derived from green plants, which has a variety of pharmacological functions, such as analgesia, anti-inflammation, antioxidation, and anti-tumor functions. However, the role and mechanism of FR in tendinopathy are unclear. Here, we found that FR improved the mechanical strength of the Achilles tendon, restored the orderly arrangement of collagen fibers, reduced inflammatory cell infiltration, and promoted tenogenesis, thereby blocking the progression of tendinopathy. Mechanistically, FR promoted the autophagic degradation of p65 by enhancing the interaction between p62 and p65 and effectively inhibited the activation of the NF-κB pathway, thus alleviating the inflammatory response of tenocytes. In addition, FR recruited E3 ubiquitin enzyme RNF182 to increase the K48-linked ubiquitination of p65 and promoted p62-mediated autophagic degradation. Furthermore, blocking ubiquitination reversed the degradation of p65 by FR. Therefore, these findings identify the new pharmacological mechanism of the anti-inflammatory effect of FR and provide a new candidate drug for the treatment of tendinopathy.

The monomer TEC of blueberry improves NASH by augmenting tRF-47-mediated autophagy/pyroptosis signaling pathway

Background

Nonalcoholic steatohepatitis (NASH) is one of the most common liver diseases and has no safe and effective drug for treatment. We have previously reported the function of blueberry, but the effective monomer and related molecular mechanism remain unclear.

Methods

The monomer of blueberry was examined by ultra performance liquid chromatography-mass spectrometry (UPLC-MS). The NASH cell model was constructed by exposing HepG2 cells to free fatty acids. The NASH mouse model was induced by a high-fat diet for 12 weeks. NASH cell and mouse models were treated with different concentrations of blueberry monomers. The molecular mechanism was studied by Oil Red O staining, ELISA, enzyme activity, haematoxylin–eosin (H&E) staining, immunohistochemistry, immunofluorescence, western blot, RNA sequencing, and qRT-PCR.

Results

We identified one of the main monomer of blueberry as tectorigenin (TEC). Cyanidin-3-O glucoside (C3G) and TEC could significantly inhibit the formation of lipid droplets in steatosis hepatocytes, and the effect of TEC on the formation of lipid droplets was significantly higher than that of C3G. TEC can promote cell proliferation and inhibit the release of inflammatory mediators in NASH cell model. Additionally, TEC administration provided a protective role against high-fat diets induced lipid damage, and suppressed lipid accumulation. In NASH mouse model, TEC can activate autophagy, inhibit pyroptosis and the release of inflammatory mediators. In NASH cell model, TEC inhibited pyroptosis by stimulating autophagy. Then, small RNA sequencing revealed that TEC up-regulated the expression of tRF-47-58ZZJQJYSWRYVMMV5BO (tRF-47). The knockdown of tRF-47 blunted the beneficial effects of TEC on NASH in vitro, including inhibition of autophagy, activation of pyroptosis and release of inflammatory factors. Similarly, suppression of tRF-47 promoted the lipid injury and lipid deposition in vivo.

Conclusions

These results demonstrated that tRF-47-mediated autophagy and pyroptosis plays a vital role in the function of TEC to treat NASH, suggesting that TEC may be a promising drug for the treatment of NASH.

Circular RNA expression profiles in human bronchial epithelial cells treated with beryllium sulfate

Circular RNAs (circRNAs), is a novel type of endogenous non-coding RNAs (ncRNAs) participated in the pathogenesis of many diseases. Beryllium is one of the carcinogenesis elements. However, the mechanism and function of circRNAs in human bronchial epithelial cells (16HBE) induced by beryllium sulfate (BeSO₄) was rarely reported. Therefore, the high-throughput RNA sequencing analysis was performed to detect the circRNA profiles between control groups and BeSO₄-induced groups. Furthermore, circRNA-miRNA-mRNA network, Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, and PPI network analysis were used for bioinformatics analysis. CircRNA sequencing analysis revealed that 36 circRNAs were up-regulated and 35 circRNAs were down-regulated in the BeSO₄-exposed groups. The selected circRNAs were verified by real-time fluorescent quantitative PCR (qRT-PCR). Hsa_circ_0004214 and hsa_circ_0003586 were validated to be up-regulated, hsa_circ_0047958, hsa_circ_0001944, and hsa_circ_0008982 were down-regulated. The circRNA-miRNA-mRNA network annotated the key signaling pathway including cellular senescence, TNF signaling pathway, NF-kappa B signaling pathway, HIF-1 signaling pathway, and Hippo signaling pathway. The PPI network indicated the most circRNAs might participate in the BeSO₄ toxicity by acting as a sponge for the miR-663b through JAK-STAT signaling pathway. In summary, our study suggests that circRNAs may play roles in the mechanism of beryllium toxicity.

Screening of key biomarkers of tendinopathy based on bioinformatics and machine learning algorithms

Tendinopathy is a complex multifaceted tendinopathy often associated with overuse and with its high prevalence resulting in significant health care costs. At present, the pathogenesis and effective treatment of tendinopathy are still not sufficiently elucidated. The purpose of this research is to intensely explore the genes, functional pathways, and immune infiltration characteristics of the occurrence and development of tendinopathy. The gene expression profile of GSE106292, GSE26051 and GSE167226 are downloaded from GEO (NCBI comprehensive gene expression database) and analyzed by WGCNA software bag using R software, GSE26051, GSE167226 data set is combined to screen the differential gene analysis. We subsequently performed gene enrichment analysis of Gene Ontology (GO) and "Kyoto Encyclopedia of Genes and Genomes" (KEGG), and immune cell infiltration analysis. By constructing the LASSO regression model, Support vector machine (SVM-REF) and Gaussian mixture model (GMMs) algorithms are used to screen, to identify early diagnostic genes. We have obtained a total of 171 DEGs through WGCNA analysis and differentially expressed genes (DEGs) screening. By GO and KEGG enrichment analysis, it is found that these dysregulated genes were related to mTOR, HIF-1, MAPK, NF-κB and VEGF signaling pathways. Immune infiltration analysis showed that M1 macrophages, activated mast cells and activated NK cells had infiltration significance. After analysis of THE LASSO SVM-REF and GMMs algorithms, we found that the gene MACROD1 may be a gene for early diagnosis. We identified the potential of tendon disease early diagnosis way and immune gene regulation MACROD1 key infiltration characteristics based on comprehensive bioinformatics analysis. These hub genes and functional pathways may as early biomarkers of tendon injuries and molecular therapy level target is used to guide drug and basic research.

Curcumenol mitigates chondrocyte inflammation by inhibiting the NF‑κB and MAPK pathways, and ameliorates DMM‑induced OA in mice

At present, an increasing number of individuals are affected by osteoarthritis (OA), resulting in a heavy socioeconomic burden. OA in knee joints is caused by the release of inflammatory cytokines and subsequent biomechanical and structural deterioration. To determine its anti‑inflammatory function, the current study investigated the use of the plant‑derived medicine, curcumenol, in OA treatment. Curcumenol was not cytotoxic to ATDC5 chondrocytes and primary chondrocytes, as determined using a cell viability test. When these cells were treated with TNF‑α and IL‑1β to induce inflammation, curcumenol treatment inhibited the progression of inflammation by inactivating the NF‑κB and MAPK signaling pathways, as well as decreasing the expression levels of MMP3 (as indicated by reverse transcription‑quantitative PCR and western blotting). Moreover, to analyze metabolic and catabolic status in high‑density and pellet culture, catalytic changes and the degradation of the extracellular matrix induced by TNF‑α and IL‑1β, were evaluated by alcian blue staining. These catalytic deteriorations were ameliorated by curcumenol. Using curcumenol in disease management, the mechanical and metabolic disruption of cartilage caused in the destabilization of medial meniscus (DMM) model was prevented in vivo. Thus, curcumenol mitigated inflammation in ATDC5 chondrocytes and primary mice chondrocytes, and also ameliorated OA in a DMM‑induced mouse model.

Spironolactone Ameliorates Senescence and Calcification by Modulating Autophagy in Rat Tendon-Derived Stem Cells via the NF-κB/MAPK Pathway

Tendinopathy is a disabling musculoskeletal disease, the pathological process of which is tightly associated with inflammation. Spironolactone (SP) has been widely used as a diuretic in clinical practice. Recently, SP has shown anti-inflammatory features in several diseases. Tendon-derived stem cells (TDSCs), a subset cell type from tendon tissue possessing clonogenic capacity, play a vital role in the pathological process of tendinopathy. In the present study, the protective effect of SP on TDSCs was demonstrated under simulated tendinopathy conditions both in vitro and in vivo. SP contributed to the maintenance of TDSC-specific genes or proteins, while suppressing the interleukin- (IL-) 1β-induced overexpression of inflammation-mediated factors. Additionally, IL-1β-induced cellular senescence in TDSCs was inhibited, while autophagy was enhanced, as determined via β-galactosidase activity, western blot (WB), and quantitative real-time polymerase chain reaction analysis. With the aid of several emerging bioinformatics tools, the mitogen-activated protein kinase (MAPK) pathway likely participated in the effect of SP, which was further validated through WB analysis and the use of MAPK agonist. Immunofluorescence analysis and an NF-κB agonist were used to confirm the inhibitory effect of SP on IL-1β-induced activation of the NF-κB pathway. X-ray, immunofluorescence, immunohistochemistry, hematoxylin and eosin staining, histological grades, and Masson staining showed that SP ameliorated tendinopathy in an Achilles tenotomy (AT) rat model in vivo. This work elucidates the protective role of SP on the pathological process of tendinopathy both in vitro and in vivo, indicating a potential therapeutic strategy for tendinopathy treatment.