Cucurbitacin E inhibits TNF-α-induced inflammatory cytokine production in human synoviocyte MH7A cells via suppression of PI3K/Akt/NF-κB pathways

Antiproliferative and immunomodulative potential of Citrullus colocynthis and its bioactive compounds in human lymphocytes and lung cells

ETHNOPHARMACOLOGICAL RELEVANCE

Citrullus colocynthis (L.) Schrad is a member of the Cucurbitaceae plant family which has been used in traditional medicine for the treatment of lung diseases such as asthma and bronchitis.

AIM OF THE STUDY

The study was conducted to investigate antiproliferative and immunomodulating effects of C. colocynthis and isolated cucurbitacins on human T lymphocytes and lung epithelial cells in order to evaluate their potential in the treatment of airway diseases.

MATERIALS AND METHODS

Different concentrations of an ethanolic extract of C. colocynthis fruits and cucurbitacins B (CuB), E (CuE) and E-glucopyranoside (CuE-Glu) were analysed for their cytotoxicity and immunomodulatory potential on Peripheral Blood Mononuclear Cells (PBMCs) of healthy donors and on the epithelial lung cancer cell line A549. Viability and proliferation were tested using WST1 and CFSE assays. Flow cytometric analysis of AnnexinV/PI staining was used to investigate cell death through apoptosis/necrosis. Effects on regulatory mechanisms of T lymphocytes, such as CD69 and CD25 marker activation, cytokine production of the cytokines interleukin 2 (IL2), tumor necrosis factor α (TNFα) and interferon γ (IFNy) were also analysed via flow cytometry. Influences on the activator protein 1 (AP1), nuclear factor of activated T-cells (NFAT) or nuclear factor 'kappa-light-chain-enhancer' of activated B-cells (NFκB) pathways were analysed in the Jurkat reporter cell line. Cytokine secretion in A549 cells stimulated with virus-like particles was analysed using the bead-based Legendplex™ assay.

RESULTS

Non-toxic concentrations of C. colocynthis and CuE-Glu showed dose-dependent effects on viability and proliferation in both T lymphocytes and A549 cells. The extracts inhibited lymphocyte activation and suppressed T cell effector functions, which was also shown by lower production of cytokines IL2, TNFα and IFNy. A dose dependent inhibition of the pathways NFκB, NFAT and AP1 in Jurkat cells could be observed. In A549 cells, especially CuE and CuE-Glu showed inhibitory effects on cytokine production following a simulated viral infection. Unglycosylated cucurbitacins were more effective in suppressing the immune function in lymphocytes than glycosylated cucurbitacins, however this activity is limited to cytotoxic concentrations.

CONCLUSION

In our study we could confirm the immunmodulating effect of C. colocynthis and cucurbitacins B, E and E-glucopyranoside in vitro by suppression of different pathways of inflammation and T cell proliferation. Activity in a lung cell model using a virus-like stimulation shows promise for further research regarding cucurbitacins in airway diseases.

Revealing the potential bioactive components and mechanism of Qianhua Gout Capsules in the treatment of gouty arthritis through network pharmacology, molecular docking and pharmacodynamic study strategies

Recent clinical studies have confirmed the effectiveness of Qianhua Gout Capsules (QGC) in the treatment of gouty arthritis (GA). However, the specific regulatory targets and mechanisms of action of QGC are still unclear. To address this gap, we utilized network pharmacology, molecular docking, and pharmacodynamic approaches to investigate the bioactive components and associated mechanisms of QGC in the treatment of GA. By employing UPLC-Q Exactive-MS, we identified the compounds present in QGC, with active ingredients defined as those with oral bioavailability ≥30 % and drug similarity ≥0.18. Subsequently, the targets of these active compounds were determined using the TCMSP database, while GA-related targets were identified from DisGeNET, GeneCards, TTD, OMIM, and DrugBank databases. Further analysis including PPI analysis, GO analysis, and KEGG pathway enrichment was conducted on the targets. Validation of the predicted results was performed using a GA rat model, evaluating pathological changes, inflammatory markers, and pathway protein expression. Our results revealed a total of 130 components, 44 active components, 16 potential shared targets, GO-enriched terms, and 47 signaling pathways related to disease targets. Key active ingredients included quercetin, kaempferol, β-sitosterol, luteolin, and wogonin. The PPI analysis highlighted five targets (PPARG, IL-6, MMP-9, IL-1β, CXCL-8) with the highest connectivity, predominantly enriched in the IL-17 signaling pathway. Molecular docking experiments demonstrated strong binding of CXCL8, IL-1β, IL-6, MMP9, and PPARG targets with the top five active compounds. Furthermore, animal experiments confirmed the efficacy of QGC in treating GA in rats, showing reductions in TNF-α, IL-6, and MDA levels, and increases in SOD levels in serum. In synovial tissues, QGC treatment upregulated CXCL8 and PPARG expression, while downregulating IL-1β, MMP9, and IL-6 expression. In conclusion, this study applied a network pharmacology approach to uncover the composition of QGC, predict its pharmacological interactions, and demonstrate its in vivo efficacy, providing insights into the anti-GA mechanisms of QGC. These findings pave the way for future investigations into the therapeutic mechanisms underlying QGC's effectiveness in the treatment of GA.

Cucurbitacin E Alleviates Colonic Barrier Function Impairment and Inflammation Response and Improves Microbial Composition on Experimental Colitis Models

Purpose

Cucurbitacins, which are found in a variety of medicinal plants, vegetables and fruits, were known for their diverse pharmacological and biological activities, including anticancer, anti-oxidative and anti-inflammatory effects. Cucurbitacin E, one of the major cucurbitacins, was recently proved to inhibit inflammatory response.

Methods

To explore the therapeutic effects of cucurbitacin E on colitis and the underlying mechanisms, male mice drunk water containing 2.5% dextran sulfate sodium (DSS) to establish colitis model and administrated with cucurbitacin E during and after DSS treatment. The disease activity index was scored and colonic histological damage was observed. Intestinal tight junction and inflammatory response were determined. 16S rRNA and transcriptome sequencing were performed to analyze gut microbiota composition and gene expression, respectively.

Results

We found that cucurbitacin E alleviated DSS-induced body weight loss and impaired colonic morphology. Cucurbitacin E decreased the expression of inflammatory cytokines and cell apoptosis, and maintained barrier function. Additionally, cucurbitacin E retrieved DSS-induced alterations in the bacterial community composition. Furthermore, a variety of differentially expressed genes (DEGs) caused by cucurbitacin E were enriched in several pathways including the NFκB and TNF signaling pathways as well as in Th17 cell differentiation. There was a close relationship between DEGs and bacteria such as Escherichia-Shigella and Muribaculaceae.

Conclusion

Our results revealed that cucurbitacin E may exert protective effects on colitis via modulating inflammatory response, microbiota composition and host gene expression. Our study supports the therapeutic potential of cucurbitacin E in colitis and indicates that gut microbes are potentially therapeutic targets.

Structurally diverse cucurbitane-type triterpenoids from the tubers of Hemsleya chinensis with cytotoxic activity

Ten previously undescribed cucurbitane-type triterpenoids, namely hemslyencins A-F (1-6) and hemslyencosides A-D (7-10), together with twenty previously reported compounds (11-30), were isolated from the tubers of Hemsleya chinensis. Their structures were elucidated by unambiguous spectroscopic data (UV, IR, HR-ESI-MS, 1D and 2D NMR data). Hemslyencins A and B (1 and 2) possessing unique 9, 11-seco-ring system with a six-membered lactone moiety, were the first examples among of the cucurbitane-type triterpenoids, and hemslyencins C and D (3 and 4) and hemslyencoside D (10) are the infrequent pentacyclic cucurbitane triterpenes featuring a 6/6/6/5/6 fused system. The cytotoxic activities of all isolated compounds were evaluated against MCF-7, HCT-116, HeLa, and HepG2 cancer cells, and their structure-activity relationships (SARs) was discussed as well. Compounds 17, 25, and 26 showed significant cytotoxic effects with IC50 values ranging from 1.31 to 9.89 μM, among which compound 25 induced both apoptosis and cell cycle arrest at G2/M phase in a dose dependent manner against MCF-7 cells.

Mechanism investigation of Duhuo Jisheng pill against rheumatoid arthritis based on a strategy for the integration of network pharmacology, molecular docking and in vivo experimental verification

CONTEXT

Duhuo Jisheng pill (DHJS) is a classic traditional Chinese medicine (TCM) formula for rheumatoid arthritis (RA). The effective components and therapeutic mechanisms of DHJS for treating RA are still unclear.

OBJECTIVE

To explore the potential mechanism of DHJS against RA by means of network pharmacology and experimental verification.

MATERIALS AND METHODS

A network pharmacology and molecular docking analysis based on phytochemistry was used to elucidate the mechanism of DHJS against RA. The targets of DHJS anti-RA active ingredient were obtained by searching TCMSP, ETCM and TCMSID. The RA model induced by collagen was established in Wistar rats. The rats in the DHJS group were administered doses of 0.5, 1.0 and 2.0 g/kg for a period of 10 d. The expression of targets was measured with Western blot.

RESULTS

Network pharmacology analysis showed that the anti-RA effect of DHJS was mediated by targets involved in immunity, inflammation and apoptosis, as well as PI3K-Akt and NF-κB signalling pathways. Of 2.0 g/kg DHJS significantly alleviated the ankle inflammation (IL-6: 62.73 ± 8.39 pg/mL, IL-1β: 50.49 ± 11.47 pg/mL, TNF-α: 16.88 ± 3.05 pg/mL, IL-17A: 12.55 ± 1.87 pg/mL, IL-10: 16.24 ± 3.00 pg/mL), comparing with the model group (IL-6: 92.02 ± 13.25 pg/mL, IL-1β: 71.85 ± 4.12 pg/mL, TNF-α: 25.64 ± 3.69 pg/mL, IL-17A: 22.14 ± 4.56 pg/mL, IL-10: 9.51 ± 3.03 pg/mL) (p < 0.05). Moreover, the protein expression of p-PI3K, p-AKT and p-p65 significantly decreased after DHJS administration.

CONCLUSIONS

DHJS could alleviate the collagen-induced arthritis (CIA) by the PI3K/AKT/NF-κB signalling pathway.

Alternations of NF-κB Signaling by Natural Compounds in Muscle-Derived Cancers

The NF-κB-signaling pathway plays a crucial role in cancer progression, including muscle-derived cancers such as rhabdomyosarcoma or sarcoma. Several natural compounds have been studied for their ability to alter NF-κB signaling in these types of cancers. This review paper summarizes the current knowledge on the effects of natural compounds, including curcumin, resveratrol, quercetin, epigallocatechin-3-gallate, and berberine, on NF-κB signaling in muscle-derived cancers. These compounds have been shown to inhibit NF-κB signaling in rhabdomyosarcoma cells through various mechanisms, such as inhibiting the activation of the IKK complex and the NF-κB transcription factor. These findings suggest that natural compounds could be potential therapeutic agents for muscle-derived cancers. However, further research is needed to fully understand their mechanisms of action and potential clinical applications.

Role of Berberine Thermosensitive Hydrogel in Periodontitis via PI3K/AKT Pathway In Vitro

Periodontitis is a long-term inflammatory illness and a leading contributor to tooth loss in humans. Due to the influence of the anatomic parameters of teeth, such as root bifurcation lesions and the depth of the periodontal pocket, basic periodontal treatment on its own often does not completely obliterate flora microorganisms. As a consequence, topical medication has become a significant supplement in the treatment of chronic periodontitis. Berberine (BBR) has various pharmacological effects, such as hypoglycemic, antitumor, antiarrhythmic, anti-inflammatory, etc. The target of our project is to develop a safe and non-toxic carrier that can effectively release berberine, which can significantly reduce periodontal tissue inflammation, and to investigate whether berberine thermosensitive hydrogel can exert anti-inflammatory and osteogenic effects by modulating phosphatifylinositol-3-kinase/Protein Kinase B (PI3K/AKT) signaling pathway. Consequently, firstly berberine temperature-sensitive hydrogel was prepared, and its characterizations showed that the mixed solution gelated within 3 min under 37 °C with a hole diameter of 10-130 µm, and the accumulation of berberine release amounted to 89.99% at 21 days. CCK-8 and live-dead cell staining results indicated that this hydrogel was not biotoxic, and it is also presumed that the optimum concentration of berberine is 5 µM, which was selected for subsequent experiments. Real-time polymerase chain reaction (qRT-PCR) and Western blotting (WB)results demonstrated that inflammatory factors, as well as protein levels, were significantly reduced in the berberine-loaded hydrogel group, and LY294002 (PI3K inhibitor) could enhance this effect (p < 0.05). In the berberine-loaded hydrogel group, osteogenesis-related factor levels and protein profiles were visibly increased, along with an increase in alkaline phosphatase expression, which was inhibited by LY294002 (p < 0.05). Therefore, berberine thermosensitive hydrogel may be an effective treatment for periodontitis, and it may exert anti-inflammatory and osteogenic effects through the PI3K/AKT signaling pathway.

Cucurbitane-type triterpenoids from the fruits of Citrullus colocynthis

A phytochemical investigation of the fruits of Citrullus colocynthis resulted in the isolation of 21 structurally diverse cucurbitane triterpenoids, including 9 previously undescribed ones, colocynins A-I (1-9). Their absolute configurations were elucidated by means of quantum chemical electronic circular dichroism (ECD) calculations, CD exciton chirality method, and single-crystal X-ray crystallography. Colocynins A-C (1-3) represent the first examples of nonanorcucurbitane-type triterpenoids. An anti-acetylcholinesterase activity assay showed that 6, 10, 13, 18, and 20 exhibited inhibitory activities, with IC₅₀ values ranging from 5.0 to 21.7 μM. In addition, 18 and 21 showed significant cytotoxicity against PACA, A431, and HepG2 cells, with IC₅₀ values ranging from 0.042 to 0.60 and 3.6-14.4 μM, respectively.

Modulation of Cytoskeleton, Protein Trafficking, and Signaling Pathways by Metabolites from Cucurbitaceae, Ericaceae, and Rosaceae Plant Families

One promising frontier within the field of Medical Botany is the study of the bioactivity of plant metabolites on human health. Although plant metabolites are metabolic byproducts that commonly regulate ecological interactions and biochemical processes in plant species, such metabolites also elicit profound effects on the cellular processes of human and other mammalian cells. In this regard, due to their potential as therapeutic agents for a variety of human diseases and induction of toxic cellular responses, further research advances are direly needed to fully understand the molecular mechanisms induced by these agents. Herein, we focus our investigation on metabolites from the Cucurbitaceae, Ericaceae, and Rosaceae plant families, for which several plant species are found within the state of Florida in Hillsborough County. Specifically, we compare the molecular mechanisms by which metabolites and/or plant extracts from these plant families modulate the cytoskeleton, protein trafficking, and cell signaling to mediate functional outcomes, as well as a discussion of current gaps in knowledge. Our efforts to lay the molecular groundwork in this broad manner hold promise in supporting future research efforts in pharmacology and drug discovery.

Magnoflorine attenuates inflammatory responses in RA by regulating the PI3K/Akt/NF-κB and Keap1-Nrf2/HO-1 signalling pathways in vivo and in vitro

BACKGROUND

As a prolonged autoimmune disorder, rheumatoid arthritis (RA) is characterised by synovial hyperplasia and the erosion of bone and cartilage. Magnoflorine (MAG) is the main component purified from Clematis manshurica Rupr. Recent studies have shown that MAG has anti-inflammatory, antioxidant, and immunosuppressive effects, which are relevant to anti-RA activities.

OBJECTIVE

The current investigation was conducted to explore the anti-RA effects of MAG and to discover the possible molecular mechanisms.

METHODS

In vitro experiments, CCK-8, wound healing, and transwell assays were utilized to evaluate the anti-proliferative, anti-migratory, and anti-invasive activities of MAG, respectively. The rate of cell distribution and cell apoptosis were evaluated by flow cytometry. ROS generation was detected by DCFH-DA staining. Western blotting, quantitative real-time polymerase chain reaction assay, and immunofluorescent staining were employed to test the anti-RA effect of MAG as well as to explore the potential mechanisms by evaluating related gene and protein expression. For in vivo experiments, an adjuvant-induced arthritis (AIA) rat model was established. The related parameters were measured in rats. Then, rats were sacrificed, and ankle joints were collected for histopathological analysis and observation.

RESULTS

MAG significantly decreased the proliferation, migration, invasion, and reactive oxygen species levels in IL-1β-treated MH7A cells. Furthermore, MAG promoted cell apoptosis by increasing Bax levels and decreasing Bcl-2 levels. MAG also induced cell cycle arrest. Inflammatory cytokines (iNOS, COX-2, IL-6, and IL-8) and MMPs (MMP-1, 2, 3, 9, and 13) were reduced by MAG treatment. Molecular analysis revealed that MAG exerted anti-RA effects by partly inhibiting the PI3K/Akt/NF-κB signalling axis and activating the Keap1-Nrf2/HO-1 signalling pathway. In vivo studies have revealed that MAG treatment substantially improved severe symptoms in AIA rats, and these curative effects were linked to the attenuation of inflammatory responses.

CONCLUSION

These results first suggested that MAG exhibits anti-arthritic effects in IL-1β-treated MH7A cells and AIA rat models. Thus, MAG may be used as a new drug to treat RA clinically.

Cucurbitacin B Down-Regulates TNF Receptor 1 Expression and Inhibits the TNF-α-Dependent Nuclear Factor κB Signaling Pathway in Human Lung Adenocarcinoma A549 Cells

Pro-inflammatory cytokines, such as tumor necrosis factor-α (TNF-α), induce the expression of intracellular adhesion molecule-1 (ICAM-1) by activating the nuclear factor κB (NF-κB) signaling pathway. In the present study, we found that cucurbitacin B decreased the expression of ICAM-1 in human lung adenocarcinoma A549 cells stimulated with TNF-α or interleukin-1α. We further investigated the mechanisms by which cucurbitacin B down-regulates TNF-α-induced ICAM-1 expression. Cucurbitacin B inhibited the nuclear translocation of the NF-κB subunit RelA and the phosphorylation of IκBα in A549 cells stimulated with TNF-α. Cucurbitacin B selectively down-regulated the expression of TNF receptor 1 (TNF-R1) without affecting three adaptor proteins (i.e., TRADD, RIPK1, and TRAF2). The TNF-α-converting enzyme inhibitor suppressed the down-regulation of TNF-R1 expression by cucurbitacin B. Glutathione, N-acetyl-L-cysteine, and, to a lesser extent, L-cysteine attenuated the inhibitory effects of cucurbitacin B on the TNF-α-induced expression of ICAM-1, suggesting that an α,β-unsaturated carbonyl moiety is essential for anti-inflammatory activity. The present results revealed that cucurbitacin B down-regulated the expression of TNF-R1 at the initial step in the TNF-α-dependent NF-κB signaling pathway.

Cucurbitacin IIa: A review of phytochemistry and pharmacology

Cucurbitacin IIa was first found in plants and it belongs to tetracyclo triterpenoids. It is one of the most important active components in cucurbitaceae plants. Studies have found that cucurbitacin IIa has a variety of pharmacological effects, such as antitumor, antiinflammatory, antibacterial, antihepatitis B virus, inhibition of human immunodeficiency virus replication, and antidepressant effect. However, the underlying mechanisms, intracellular targets, and structure-activity relationships of cucurbitacin IIa remain to be completely elucidated. This review summarizes the current advances concerning the phytochemistry and pharmacology of cucurbitacin IIa. Electronic databases such as PubMed, Web of Science, Google Scholar, Science Direct, and CNKI were used to find relevant information about cucurbitacin IIa using keywords such as "Cucurbitacin IIa," "Pharmacology," and "Phytochemistry." These pharmacological effects involve the actin cytoskeleton aggregation, the regulation of JAK2/STAT3, ERBB-MAPK, CaMKII α/CREB/BDNF signal pathways, as well as the regulation of survivin, caspases, and other cell cycles, apoptosis, autophagy-related cytokines, and kinases. It has high development and use value.

Metabolic Reprogramming and Inflammatory Response Induced by D-Lactate in Bovine Fibroblast-Like Synoviocytes Depends on HIF-1 Activity

Acute ruminal acidosis (ARA) occurs after an excessive intake of rapidly fermentable carbohydrates and is characterized by the overproduction of D-lactate in the rumen that reaches the bloodstream. Lameness presentation, one of the primary consequences of ARA in cattle, is associated with the occurrence of laminitis and aseptic polysynovitis. Fibroblast-like synoviocytes (FLS) are predominant cells of synovia and play a key role in the pathophysiology of joint diseases, thus increasing the chances of the release of pro-inflammatory cytokines. Increased D-lactate levels and disturbances in the metabolism of carbohydrates, pyruvates, and amino acids are observed in the synovial fluid of heifers with ARA-related polysynovitis prior to neutrophil infiltration, suggesting an early involvement of metabolic disturbances in joint inflammation. We hypothesized that D-lactate induces metabolic reprogramming, along with an inflammatory response, in bovine exposed FLS. Gas chromatography-mass spectrometry (GC-MS)-based metabolomics revealed that D-lactate disrupts the metabolism of bovine FLS, mainly enhancing glycolysis and gluconeogenesis, pyruvate metabolism, and galactose metabolism. The reverse-transcription quantitative PCR (RT-qPCR) analysis revealed an increased expression of metabolic-related genes, including hypoxia-inducible factor 1 (HIF-1)α, glucose transporter 1 (Glut-1), L-lactate dehydrogenase subunit A (L-LDHA), and pyruvate dehydrogenase kinase 1 (PDK-1). Along with metabolic disturbances, D-lactate also induced an overexpression and the secretion of IL-6. Furthermore, the inhibition of HIF-1, PI3K/Akt, and NF-κB reduced the expression of IL-6 and metabolic-related genes. The results of this study reveal a potential role for D-lactate in bFLS metabolic reprogramming and support a close relationship between inflammation and metabolism in cattle.

Phosphatidylinositol 3-kinase gamma participates in nimesulide-induced hepatic damage

OBJECTIVE

To evaluate the participation of the phosphatidylinositol 3-kinase pathway in the liver damage caused by nimesulide.

METHODS

Liver damage been induced by nimesulide. Mice were treated with either 2% dimethyl sulfoxide or AS605240, a phosphatidylinositol 3-kinase gamma pathway antagonist. Blood samples were collected for function assays of liver. The liver was removed for analysis of liver weight/animal weight ratio, histopathological parameters, oxidative and nitrous stress, cytokine levels, and the immunostaining for cyclooxygenase 2 and nuclear factor kappa B.

KEY FINDINGS

Liver injured by nimesulide and treated with phosphatidylinositol 3-kinase gamma inhibitor significantly reversed (P < 0.05) the damage; it decreased the liver weight/animal weight ratio, histopathological scores, and neutrophil infiltration, consequently reducing oxidative stress. In addition, we show that phosphatidylinositol 3-kinase gamma is associated with hepatic damage induced by nimesulide, because it altered liver function and increased the protein immunostaining of cyclooxygenase 2 and nuclear factor kappa B in the liver tissue of nimesulide-treated animals.

CONCLUSIONS

The findings from the present study allows us to infer that nimesulide causes liver damage through the phosphatidylinositol 3-kinase gamma pathway.

Repurposing of Pirfenidone (Anti-Pulmonary Fibrosis Drug) for Treatment of Rheumatoid Arthritis

Clinical studies have shown that pirfenidone (PFD) effectively relieves joint pain in rheumatoid arthritis (RA) patients. However, the detailed mechanisms underlying the anti-RA effects of PFD have not been investigated. This study was undertaken to investigate the repurposing of PFD for the treatment of RA, and explore its anti-rheumatic mechanisms. A collagen-induced arthritis (CIA) rat model was used to observe joint pathological changes following PFD treatment. Based on bioinformatics to predict the mechanism of PFD anti-RA, using EA. hy926 and TNF-α-induced MH7A cells to establish in vitro model to explore its biological mechanism from the perspectives of synovial inflammation and angiogenesis. PFD significantly relieved pathological changes, including joint swelling, synovial hyperplasia, inflammatory cell infiltration and joint destruction. PFD was also associated with reduced expression of MMP-3 and VEGF in articular chondrocytes and synovial cells of CIA rats (p < 0.05). Using bioinformatic methods, we predicted that PFD inhibits cell inflammation and migration by interfering with the JAK2/STAT3 and Akt pathways. These results were verified using in vitro models. In particular, PFD effectively reduced the expression of pro-inflammatory, chondrogenic, and angiogenic cytokines, such as IL-1β, IL-6, IL-8, MMP-1/3/2/9 and VEGF (p < 0.05), in TNF-α-induced MH7A cells. In addition, PFD significantly reduced the production of MMP-2/9 and VEGF in EA. hy926 cells, thereby weakening migration and inhibiting angiogenesis (p < 0.05). These findings suggest that PFD may alleviate the pathological process in CIA rats, by inhibiting inflammation and angiogenesis through multiple pathways, and serve as a potential therapeutic drug for RA.

LncRNA GAS5 alleviates rheumatoid arthritis through regulating miR-222-3p/Sirt1 signalling axis

INTRODUCTION

Rheumatoid arthritis (RA) is an autoimmune disease that affects millions of people. Fibroblast-like synoviocytes (FLSs) located in rheumatoid panni play a pivotal role in the formation of RA. The long noncoding RNA (lncRNA) GAS5 is reportedly downregulated in rheumatoid arthritis. However, its detailed mechanism in RA remains to be explored. This study investigated the roles and related mechanisms of GAS5 in RA.

METHODS

The expression levels of GAS5, miR-222-3p, and sirtuin 1 (Sirt1) were evaluated by quantitative PCR (qPCR). Cell proliferation was analyzed by CCK-8 and BrdU assays. Cell apoptosis was assessed by flow cytometry and western blotting. Enzyme-linked immunosorbent assay (ELISA) was utilized to evaluate the levels of TNF-α, IL-1β, and IL-6. The interaction between GAS5 or Sirt1 and miR-222-3p was predicted by starBase and validated by dual-luciferase reporter assay.

RESULTS

GAS5 expression was found to be downregulated in the serum samples of RA patients and in RA-FLSs. GAS5 overexpression or the inhibition of miR-222-3p impeded the activity of RA-FLSs by repressing their proliferation and inflammation and by promoting apoptosis. Mechanistically, GAS5 indirectly regulates Sirt1 expression by binding miR-222-3p. Further experiments confirmed that Sirt1 overexpression restored the anti-RA activity of GAS5 under miR-222-3p mimic.

CONCLUSIONS

The miR-222-3p/Sirt1 axis was found to be critical for the function of GAS5 in regulating the proliferation, inflammation, and apoptosis of RA-FLSs. These data indicate GAS5 activation as a potential therapeutic strategy for RA progression.

HtrA2 is required for inflammatory responses in BMDMs via controlling TRAF2 stability in collagen-induced arthritis

Rheumatoid arthritis (RA) is an autoimmune inflammatory disease characterized by the destruction of cartilage and bone. The present study aims to investigate the role of HtrA serine peptidase 2 (HtrA2) in the collagen-induced arthritis. The expressions of HtrA2 were determined in the database BioGPS and bone marrow-derived macrophages (BMDMs). The populations of myeloid and lymphoid cells were determined in wild type and HtrA2 knockout (HtrA2^MKO) mice using flow cytometry. In addition, the expressions of pro-inflammatory cytokines (Il6, Tnf, and Il1β) were determined in the activated BMDMs from wild type (WT) and HtrA2^MKO mice. STRING database was used to predict the interactive proteins of HtrA2 and Co-Immunoprecipitation was used to confirm these interactions. A collagen-induced arthritis model was established to investigate the effects of HtrA2 on the arthritis symptoms. It was found that HtrA2 reduction was associated with the activation of myeloid cells. Interestingly, HtrA2 deficiency did not affect the development of myeloid and lymphoid cells. Further studies demonstrated that HtrA2 deficiency suppressed the production of pro-inflammatory cytokines in BMDMs induced by lipopolysaccharide or CpG. Co-Immunoprecipitation results demonstrated that HtrA2 enhanced the stability of TNF receptor-associated factor 2 (TRAF2). HtrA2 participated in the activation of the inflammatory response in a collagen-induced arthritis model. In summary, HtrA2 modulates inflammatory responses in BMDMs by controlling TRAF2 stability in a collagen-induced arthritis mouse model.

D-Lactate Increases Cytokine Production in Bovine Fibroblast-Like Synoviocytes via MCT1 Uptake and the MAPK, PI3K/Akt, and NFκB Pathways

Acute ruminal acidosis (ARA) is caused by the excessive intake of highly fermentable carbohydrates, followed by the massive production of D-lactate and the appearance of neutrophilic aseptic polysynovitis. Bovines with ARA develop different lesions, such as ruminitis, polioencephalomalacia (calves), liver abscess and lameness. Lameness in cattle with ARA is closely associated with the presence of laminitis and polysynovitis. However, despite decades of research in bovine lameness as consequence of ruminal acidosis, the aetiology and pathogenesis remain unclear. Fibroblast-like synoviocytes (FLSs) are components of synovial tissue, and under pathological conditions, FLSs increase cytokine production, aggravating inflammatory responses. We hypothesized that D-lactate could induce cytokine production in bovine FLSs. Analysis by qRT-PCR and ELISA revealed that D-lactate, but not L-lactate, increased the expression of IL-6 and IL-8 in a monocarboxylate transporter-1-dependent manner. In addition, we observed that the inhibition of the p38, ERK1/2, PI3K/Akt, and NF-κB pathways reduced the production of IL-8 and IL-6. In conclusion, our results suggest that D-lactate induces an inflammatory response; this study contributes to the literature by revealing a potential key role of D-lactate in the polysynovitis of cattle with ARA.

In silico and in vitro studies reveal complement system drives coagulation cascade in SARS-CoV-2 pathogenesis

The emergence and continued spread of SARS-CoV-2 have resulted in a public health emergency across the globe. The lack of knowledge on the precise mechanism of viral pathogenesis is impeding medical intervention. In this study, we have taken both in silico and in vitro experimental approaches to unravel the mechanism of viral pathogenesis associated with complement and coagulation pathways. Based on the structural similarities of viral and host proteins, we initially generated a protein-protein interactome profile. Further computational analysis combined with Gene Ontology (GO) analysis and KEGG pathway analysis predicted key annotated pathways associated with viral pathogenesis. These include MAPK signaling, complement, and coagulation cascades, endocytosis, PD-L1 expression, PD-1 checkpoint pathway in cancer and C-type lectin receptor signaling pathways. Degree centrality analysis pinned down to MAPK1, MAPK3, AKT1, and SRC are crucial drivers of signaling pathways and often overlap with the associated pathways. Most strikingly, the complement and coagulation cascade and platelet activation pathways are interconnected, presumably directing thrombotic activity observed in severe or critical cases of COVID-19. This is complemented by in vitro studies of Huh7 cell infection and analysis of the transcriptome and proteomic profile of gene candidates during viral infection. The most known candidates associated with complement and coagulation cascade signaling by KEGG pathway analysis showed significant up-regulated fold change during viral infection. Collectively both in silico and in vitro studies suggest complement and coagulation cascade signaling are a mechanism for intravascular coagulation, thrombotic changes, and associated complications in severe COVID-19 patients.

Tanshinone IIA Suppresses Proliferation and Inflammatory Cytokine Production of Synovial Fibroblasts from Rheumatoid Arthritis Patients Induced by TNF-α and Attenuates the Inflammatory Response in AIA Mice

Rheumatoid arthritis (RA) is a chronic and progressive autoimmune disease in which activated RA fibroblast-1ike synoviocytes (RA-FLSs) are one of the main factors responsible for inducing morbidity. Previous reports have shown that RA-FLSs have proliferative features similar to cancer cells, in addition to causing cartilage erosion that eventually causes joint damage. Thus, new therapeutic strategies and drugs that can effectively contain the abnormal hyperplasia of RA-FLSs and restrain RA development are necessary for the treatment of RA. Tanshinone IIA (Tan IIA), one of the main phytochemicals isolated from Salvia miltiorrhiza Bunge, is capable of promoting RA-FLS apoptosis and inhibiting arthritis in an AIA mouse model. In addition, RA patients treated at our clinic with Tan IIA showed significant improvements in their clinical symptoms. However, the details of the molecular mechanism by which Tan IIA effects RA are unknown. To clarify this mechanism, we evaluated the antiproliferative and inhibitory effects of proinflammatory factor production caused by Tan IIA to RA-FLSs. We demonstrated that Tan IIA can restrict the proliferation, migration, and invasion of RA-FLSs in a time- and dose-dependent manner. Moreover, Tan IIA effectively suppressed the increase in mRNA expression of some matrix metalloproteinases and proinflammatory factors induced by TNF-α in RA-FLSs, resulting in inflammatory reactivity inhibition and blocking the destruction of the knee joint. Through the integration of network pharmacology analyses with the experimental data obtained, it is revealed that the effects of Tan IIA on RA can be attributed to its influence on different signaling pathways, including MAPK, AKT/mTOR, HIF-1, and NF-kB. Taken together, these data suggest that the compound Tan IIA has great therapeutic potential for RA treatment.

Cinnamaldehyde Inhibits Inflammation of Human Synoviocyte Cells Through Regulation of Jak/Stat Pathway and Ameliorates Collagen-Induced Arthritis in Rats

Cinnamaldehyde (Cin), a bioactive cinnamon essential oil from traditional Chinese medicine herb Cinnamomum cassia, has been reported to have multipharmacological activities including anti-inflammation. However, its role and molecular mechanism of anti-inflammatory activity in musculoskeletal tissues remains unclear. Here, we first investigated the effects and molecular mechanisms of Cin in human synoviocyte cells. Then in vivo therapeutic effect of Cin on collagen-induced arthritis (CIA) also studied. Cell Counting Kit ‎CCK-8 assay was performed to evaluate the cell cytotoxicity. Proinflammatory cytokine expression was evaluated using quantitative polymerase chain reaction and ELISA. Protein expression was measured by western blotting. The in vivo effect of Cin (75 mg/kg per day) was evaluated in rats with CIA by gavage administration. Disease progression was assessed by clinical scoring, radiographic, and histologic examinations. Cin significantly inhibited interleukin (IL)-1β-induced IL-6, IL-8, and tumor necrosis factor-α release from human synoviocyte cells. The molecular analysis revealed that Cin impaired IL-6-induced activation of Janus kinase 2 (JAK2), signal transducer and activator of transcription 1 (STAT1), and STAT3 signaling pathway by inhibiting the phosphorylation of JAK2, STAT1, and STAT3, without affecting NF-κB pathway. Cin reduced collagen-induced swollen paw volume of arthritic rats. The anti-inflammation effects of Cin were associated with decreased severity of arthritis, joint swelling, and reduced bone erosion and destruction. Furthermore, serum IL-6 level was decreased when Cin administered therapeutically to CIA rats. Cin suppresses IL-1β-induced inflammation in synoviocytes through the JAK/STAT pathway and alleviated collagen-induced arthritis in rats. These data indicated that Cin might be a potential traditional Chinese medicine-derived, disease-modifying, antirheumatic herbal drug. SIGNIFICANCE STATEMENT: In this study, we found that cinnamaldehyde (Cin) suppressed proinflammatory cytokines secretion in rheumatology arthritis synoviocyte cells by Janus kinase/signal transducer and activator of transcription pathway. The in vivo results showed that Cin ameliorated collagen-induced arthritis in rats. These findings indicate that Cin is a potential traditional Chinese medicine-derived, disease-modifying, antirheumatic herbal drug.

PBT-6, a Novel PI3KC2γ Inhibitor in Rheumatoid Arthritis

Phosphoinositide 3-kinase (PI3K) is considered as a promising therapeutic target for rheumatoid arthritis (RA) because of its involvement in inflammatory processes. However, limited studies have reported the involvement of PI3KC2γ in RA, and the underlying mechanism remains largely unknown. Therefore, we investigated the role of PI3KC2γ as a novel therapeutic target for RA and the effect of its selective inhibitor, PBT-6. In this study, we observed that PI3KC2γ was markedly increased in the synovial fluid and tissue as well as the PBMCs of patients with RA. PBT-6, a novel PI3KC2γ inhibitor, decreased the cell growth of TNF-mediated synovial fibroblasts and LPS-mediated macrophages. Furthermore, PBT-6 inhibited the PI3KC2γ expression and PI3K/ AKT signaling pathway in both synovial fibroblasts and macrophages. In addition, PBT-6 suppressed macrophage migration via CCL2 and osteoclastogenesis. In CIA mice, it significantly inhibited the progression and development of RA by decreasing arthritis scores and paw swelling. Three-dimensional micro-computed tomography confirmed that PBT-6 enhanced the joint structures in CIA mice. Taken together, our findings suggest that PI3KC2γ is a therapeutic target for RA, and PBT-6 could be developed as a novel PI3KC2γ inhibitor to target inflammatory diseases including RA.

Development and Validation of Novel Dietary and Lifestyle Inflammation Scores

BACKGROUND

Chronically higher inflammation, which may partly result from diet and lifestyle, is implicated in risk for multiple chronic diseases. The dietary inflammatory index (DII) and empirical dietary inflammatory pattern (EDIP), developed to characterize dietary contributions to systemic inflammation, have several limitations. There are no scores to characterize contributions of lifestyle to inflammation.

OBJECTIVES

To reflect dietary/lifestyle contributions to inflammation, we developed novel, inflammation biomarker panel-weighted, dietary (DIS) and lifestyle (LIS) inflammation scores in a subset (n = 639) of the Reasons for Geographic and Racial Differences in Stroke Study (REGARDS) cohort.

METHODS

We selected a priori 19 food groups and 4 lifestyle characteristics to comprise the DIS and LIS, respectively. We calculated the components' weights based on their strengths of association with an inflammation biomarker score [comprising high-sensitivity C-reactive protein (hsCRP), IL-6, IL-8, and IL-10] using multivariable linear regression. The sums of the weighted components constitute the scores, such that higher scores reflect, on balance, more proinflammatory exposures. We calculated the DIS, LIS, DII, and EDIP with cross-sectional data from the remaining REGARDS cohort (  n = 14,210 with hsCRP measurements) and 2 other study populations with hsCRP and/or an 8-component inflammation biomarker panel, and investigated their associations with circulating inflammation biomarker concentrations using multivariable logistic regression.

RESULTS

In REGARDS, those in the highest relative to the lowest DIS, LIS, DII, and EDIP quintiles had statistically significant 1.66-, 4.29-, 1.56-, and 1.32-fold higher odds of a high hsCRP concentration (>3 mg/dL), respectively (all P-trend < 0.001). Those in the highest relative to the lowest joint DIS/LIS quintile had a statistically significant 7.26-fold higher odds of a high hsCRP concentration. Similar findings were noted in the other 2 validation populations.

CONCLUSION

Our results support that dietary and lifestyle exposures collectively contribute substantially to systemic inflammation, and support the use of our novel DIS and LIS.

Cucurbitacin E ameliorates lipopolysaccharide-evoked injury, inflammation and MUC5AC expression in bronchial epithelial cells by restraining the HMGB1-TLR4-NF-κB signaling

Asthma is a chronic inflammatory disorder of airway affecting people from childhood to old age, and is characterized by airway epithelial dysfunction. Cucurbitacin E (CuE), a tetracyclic triterpene isolated from Cucurbitaceae plants, has been recently proved to exert anti-inflammation and immunology regulation activities. Nevertheless, its roles in asthma remains poorly defined. In the current study, CuE had little cytotoxicity on cell viability of human bronchial epithelial cell line BEAS-2B. Moreover, lipopolysaccharide (LPS) exposure inhibited cell viability and induced cell apoptosis, which was reversed following CuE pretreatment. Additionally, CuE administration suppressed LPS-induced inflammatory cytokine production, including TNF-α, IL-6, and IL-8. Simultaneously, supplementation with CuE decreased the transcripts and releases of mucin 5AC (MUC5AC) in LPS-treated BEAS-2B cells. Intriguingly, CuE inhibited LPS-evoked activation of the high-mobility group box1 (HMGB1)-TLR4-NF-κB signaling by reducing the expression of HMGB1, TLR4 and p-p65 NF-κB. Notably, restoring this pathway by elevating HMGB1 expression largely offset the protective function of CuE against LPS-triggered cell injury, inflammatory response and MUC5AC expression. Consequently, these findings highlight that CuE can ameliorate human bronchial epithelial cell insult and inflammation under LPS-simulated asthmatic conditions by blocking the HMGB1-TLR4-NF-κB signaling, thereby supporting its usefulness as a promising therapeutic agent against asthma.

Herbal compounds for rheumatoid arthritis: Literatures review and cheminformatics prediction

Rheumatoid arthritis (RA) is a systemic disease characterized by autoimmunity, joint inflammation, and cartilage destruction, which affects 0.5-1% of the population. Many compounds from herbal medicines show the potentials to treat RA. On this basis, the compounds with good pharmacokinetic behaviors and drug-likeness properties will be further studied and developed. Therefore, the herbal compounds with anti-RA activities were reviewed in this paper, and the cheminformatics tools were used to predict their drug-likeness properties and pharmacokinetic parameters. A total of 90 herbal compounds were analyzed, which were reported to be effective on RA models through anti-inflammation, chondroprotection, immunoregulation, antiangiogenesis, and antioxidation. Most of the herbal compounds have good drug-likeness properties. Most of the compounds can be an alternative and valuable source for anti-RA drug discovery.

Cucurbitacin E glucoside from Citrullus colocynthis inhibits testosterone-induced benign prostatic hyperplasia in mice

Benign prostatic hyperplasia (BPH) is a common disorder in men aged over 60 years and significantly contributes to the distressing lower urinary tract symptoms. Cucurbitacins are triterpene derivatives with diverse medicinal uses including prostate diseases. Cucurbitacin E glucoside was evaluated against testosterone-induced prostatic hyperplasia in mice. Our data indicate that it significantly inhibited the increase in prostate weight and prostate index. The compound ameliorated histopathological changes in prostatic architecture and inhibited the increase in glandular epithelial length induced by testosterone. These results were confirmed by decreased expression of cyclin D1 in prostatic tissues compared to those obtained from the testosterone-alone group. Also, it showed significant antioxidant activity as evidenced by inhibiting lipid peroxides accumulation, glutathione depletion and superoxide exhaustion. Further, it exhibited anti-inflammatory activity as it decreased cyclooxygenase-2 and interleukin-1β protein expression in prostatic tissues. Masson's trichrome staining of prostate sections indicated obvious antifibrotic activity that was supported by decreased α-smooth muscle actin expression. In conclusion, Cucurbitacin E glucoside inhibits testosterone-induced experimental BPH in mice due to, at least partly, its antiproliferative, antioxidant, anti-inflammatory, and antifibrotic effects.

Pectolinarin inhibits proliferation, induces apoptosis, and suppresses inflammation in rheumatoid arthritis fibroblast-like synoviocytes by inactivating the phosphatidylinositol 3 kinase/protein kinase B pathway

Rheumatoid arthritis fibroblast-like synoviocytes (RA-FLSs), a pathological hallmark of rheumatoid arthritis (RA), exhibit the characteristics of tumor cells. The extracts of Cirsium japonicum var. ussuriense have been shown to possess antitumor and anti-inflammatory activities. Our study aimed to investigate the effects of pectolinarin, a flavonoid compound isolated from C. japonicum var. ussuriense, on RA. Cell viability was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide assay. Apoptosis was determined by flow cytometry analysis and Western blot analysis of Bax and Bcl-2 levels. Inflammation was assessed by detecting the expressions and secretion of interleukin (IL)-6 and IL-8 using quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. The production of nitric oxide (NO) and prostaglandin E2 (PGE2) was also measured. The effects of pectolinarin on the phosphatidylinositol 3 kinase (PI3K)/protein kinase B (Akt) pathway were examined by Western blot. We found that pectolinarin significantly inhibited cell viability at 24 and 48 hours in a dose-dependently manner in RA-FLSs. Pectolinarin reduced the apoptotic rate, increased Bax level, and decreased Bcl-2 level in RA-FLSs. Pectolinarin inhibited the messenger RNA expression and secretion of IL-6 and IL-8, as well as the production of PGE2 and NO in RA-FLSs. Furthermore, pectolinarin inactivated the phosphatidylinositol 3 kinase/protein kinase B (PI3K/Akt) pathway in RA-FLSs. Activation of the PI3K/Akt pathway by 740Y-P impaired the effects of pectolinarin on cell viability, apoptosis, and inflammation in RA-FLSs. In conclusion, pectolinarin suppressed cell proliferation and inflammatory response and induced apoptosis in RA-FLSs via inactivation of the PI3K/Akt pathway.

Astragalin Suppresses Inflammatory Responses and Bone Destruction in Mice With Collagen-Induced Arthritis and in Human Fibroblast-Like Synoviocytes

Astragalin, as a bioactive flavonoid with anti-inflammatory, antioxidant, and protective properties, provides a potential agent for rheumatoid arthritis (RA). In this study, its therapeutic efficacy and the underlying mechanisms were explored using DBA/1J mice with collagen-induced arthritis (CIA). It was demonstrated that astragalin could significantly attenuate inflammation of CIA mice. The effects were associated with decreased severity of arthritis (based on the arthritis index), joint swelling and reduced bone erosion and destruction. Furthermore, astragalin treatment suppressed the production of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6, and IL-8), and inhibited the expression of matrix metalloproteinases (MMP-1, MMP-3, and MMP-13) in chondrocytes and synovial cells of CIA mice. Fibroblast-like synoviocytes derived from RA patients (MH7A cells) were applied to verify these effects. In vitro, astragalin inhibited the expression of matrix metalloproteinases (MMP-1, MMP-3, and MMP-13) dose-dependently in TNF-α-induced MH7A cells, with no apparent cytotoxicity. Furthermore, astragalin suppressed the phosphorylation of p38, JNK, and the activation of c-Jun/AP-1 in TNF-α-induced MH7A cells. In conclusion, it has proven that astragalin could attenuate synovial inflammation and joint destruction in RA at least partially by restraining the phosphorylation of MAPKs and the activating of c-Jun/AP-1. Therefore, astragalin can be a potential therapeutic agent for RA.

Protective effect of avicularin on rheumatoid arthritis and its associated mechanisms

The present study aimed to investigate the effect of avicularin on rheumatoid arthritis (RA) in vitro, and additionally explore the molecular mechanism. To perform this investigation, an in vitro model of RA was established by treatment of the human RA synovial MH7A cell line with tumor necrosis factor-α (TNF-α). MH7A cells were then treated with various concentrations (10, 30, 100 and 300 µM) of avicularin. Then, the levels of inflammatory factors [interleukin (IL)-1β, IL-6, IL-8, matrix metalloproteinase (MMP)-1 and MMP-13] were measured by ELISA. Cell viability and apoptosis were detected using an MTT assay and flow cytometry, respectively. In addition, the expression levels of genes and proteins were determined reverse transcription quantitative polymerase chain reaction and western blot analysis. The results of the present study indicated that avicularin significantly decreased the levels of inflammatory factors (IL-1β, IL-6, IL-8, MMP-1 and MMP-13), previously increased by TNF-α, in a dose-dependent manner. Concurrently, avicularin inhibited the mRNA and protein expression levels of iNOS and COX-2 increased by TNF-α. It was also identified that TNF-α administration significantly promoted MH7A cell viability and inhibited cell apoptosis, and avicularin treatment dose-dependently inhibited MH7A cell viability and induced cell apoptosis. In addition, these data suggested that avicularin prevented the activation of the mitogen-activated protein kinase kinase (MEK)/nuclear factor kappa light-chain-enhancer of activated B-cells (NF-κB) pathway activated by TNF-α. Taken together, these results demonstrated that avicularin may inhibit the inflammatory response, prevent cell viability and induce apoptosis in human RA synovial cells through preventing the activation of the MEK/NF-κB pathway.

Colocynthenins A-D, Ring-A seco-Cucurbitane Triterpenoids from the Fruits of Citrullus colocynthis

Four ring-A seco-cucurbitane triterpenoids, colocynthenins A-D (1-4), together with seven known cucurbitane triterpenoids (5-11), were isolated from the fruits of Citrullus colocynthis. Their structures and absolute configurations were elucidated based on spectroscopic analysis and quantum chemical ECD calculations. Compound 1 possesses an unprecedented 2,11-lactone moiety, while compound 2 is the first reported cucurbitane triterpenoid with an unusual cyano group. Compounds 1 and 3 showed acetylcholinesterase inhibitory activities in a standard in vitro assay, with IC₅₀ values of 2.6 and 3.1 μM, respectively.

4-(Hydroxymethyl)catechol Extracted From Fungi in Marine Sponges Attenuates Rheumatoid Arthritis by Inhibiting PI3K/Akt/NF-κB Signaling

Rheumatoid arthritis (RA) is a progressive autoimmune disease specific to synovial joints; it causes joint damage and other systemic abnormalities, thereby leading to physical disability and early mortality. Marine sponge-derived fungi, Pestalotiopsis sp., secrete immunosuppressive compounds in the culture broth. In the present study, we isolated 4-(hydroxymethyl)catechol (4-HMC) from these fungal species, and evaluated its anti-RA effects using a murine collagen-induced arthritis model and tumor necrosis factor-α-stimulated human RA synovial fibroblasts. Oral 4-HMC administration decreased the clinical arthritis score, paw thickness, histologic and radiologic changes, and serum IgG1 and IgG2a levels. It prevented the proliferation of helper T (Th) 1/Th17 CD4⁺ lymphocytes isolated from inguinal lymph nodes, thereby reducing inflammatory cytokine production in CIA mice. It decreased the expression of inflammatory mediators, including cytokines and matrix metalloproteinases (MMPs), both in vitro and in vivo. We observed that 4-HMC suppresses Th immune responses and MMP expression to inhibit inflammatory cytokine production in human RA synovial fibroblasts by modulating the PI3K/Akt/NF-κB pathway. These results verify the anti-RA potential of 4-HMC.

Paeoniflorin Antagonizes TNF-α-Induced L929 Fibroblastoma Cells Apoptosis by Inhibiting NF-κBp65 Activation

Paeoniflorin (PF) is one of the main pharmacodynamic components of Paeonia suffruticosa Andr, which has a significant anti-inflammatory effect on rheumatoid arthritis (RA), with a mechanism related to the tumor necrosis factor α (TNF-α). The aim of the present study was to investigate the role of PF in the apoptosis and expression of NF-κBp65 of L929 fibroblastoma cells induced by TNF-α. Our results showed that different concentrations of PF can significantly reduce the growth inhibition of L929 cells. Moreover, morphological observations, Hoechst 33342 staining, and flow cytometry detection of apoptosis showed that PF can significantly attenuate the TNF-α-induced apoptosis in a dose-dependent manner. Western blot analysis revealed that TNF-α induced the activation of NF-κBp65, whereas PF treatment had a marked dose-dependent suppression on it, which indicates that its action might be associated with inhibiting NF-κB signaling pathway. These results show that PF exerts a beneficial effect on L929 cells to prevent TNF-α-induced apoptosis and expression of NF-κBp65, which would be helpful to clarify its role in the treatment of RA.

MicroRNA-126 affects rheumatoid arthritis synovial fibroblast proliferation and apoptosis by targeting PIK3R2 and regulating PI3K-AKT signal pathway

Rheumatoid arthritis (RA) is a chronic autoimmune disease that causes inflammation and destruction of the joints as well as an increased risk of cardiovascular disease. RA synovial fibroblasts (RASFs) are involved in the progression of RA and release pro-inflammatory cytokines. On the other hand, microRNAs (miRs) may help control the inflammatory response of immune and non-immune cells. Therefore, our study used lentiviral expression vectors to test the effects of miR-126 overexpression on RASF proliferation and apoptosis. Luciferase experiments verified the targeting relationship between miR-126 and PIK3R2 gene. The co-transfection of anti-miR-126 and PIK3R2 siRNA to RASFs were used to identify whether PIK3R2 was directly involved in proliferation and apoptosis of miR-126-induced RASFs. Real-time polymerase chain reaction (PCR) was used to detect miR-126 and PIK3R2 expressions. MTT assay was used to detect cell proliferation. Flow cytometry was used to detect cell apoptosis and cell cycle. Western blotting was used to detect PIK3R2, PI3K, AKT and p-AKT proteins. After Lv-miR-126 infected RASFs, the relative expression of miR-126 was significantly enhanced. MiR-126 promoted RASF proliferation and inhibited apoptosis. Levels of PIK3R2 decreased while total PI3K and p-AKT levels increased in RASFs overexpressing miR-126. Co-transfection of anti-miR-126 and PIK3R2 siRNA also increased PI3K and p-AKT levels as well as RASF proliferation and reduced apoptosis, as compared to anti-miR-126 treatment alone. Finally, luciferase reporter assays showed that miR-126 targeted PIK3R2. Our data indicate that miR-126 overexpression in RASFs inhibits PIK3R2 expression and promotes proliferation while inhibiting apoptosis. This suggests inhibiting miR-126 may yield therapeutic benefits in the treatment of RA.

MicroRNA-130a regulates chondrocyte proliferation and alleviates osteoarthritis through PTEN/PI3K/Akt signaling pathway

The function of microRNA‑130a in development and progression of osteoarthritis was determined. In osteoarthritis patients, the serum levels of microRNA‑130a were decreased, compared with normal group. Overexpression of microRNA‑130a increased cell proliferation and decreased apoptosis of chondrocytes, and downregulation of microRNA‑130a also decreased cell proliferation and induced apoptosis in chondrocytes. Downregulation of microRNA‑130a promoted Bax and caspase‑3/9 protein expression, increased inflammation divisors and suppressed the PTEN/PI3K/Akt signaling pathway. PTEN inhibitor, VO‑Ohpic trihydrate increased the destructive effect of microRNA‑130a on cell proliferation of chondrocytes. PI3K inhibitor, wortmannin also increased the destructive effect of microRNA‑130a on osteoarthritis. In conclusion, microRNA‑130a is an important regulator of osteoarthritis in chondrocytes through PTEN/PI3K/Akt signaling pathway.

miR-143-3p regulates cell proliferation and apoptosis by targeting IGF1R and IGFBP5 and regulating the Ras/p38 MAPK signaling pathway in rheumatoid arthritis

It has been demonstrated that the deregulation of microRNAs (miRNAs) affects the development of rheumatoid arthritis (RA). The primary objective of the current study was to determine the role of miR-143-3p in the progression of RA. The expression of miR-143-3p in synovium taken from patients with RA was assessed by reverse transcription-quantitative polymerase chain reaction. The expression of miR-143-3p was higher in synovium tissues of RA than that of osteoarthritis (OA). The decreased expression of miR-143-3p suppressed cell proliferation and promoted apoptosis in vitro. In addition, inhibition of miR-143-3p decreased levels of inflammatory cytokines, as determined by an enzyme-linked immunosorbent assay. IGF1R and IGFBP5 were found to be the target genes of miR-143-3p, and it was demonstrated that miR-143-3p regulated the proliferation and apoptosis of MH7A cells by targeting IGF1R and IGFBP5. Furthermore, TNF-α treatment stimulated the Ras/p38 mitogen activated protein kinase (MAPK) signaling pathway, whereas miR-143-3p inhibition suppressed it. The results of the current study indicate that miR-143-3p may regulate cell proliferation and apoptosis by targeting IGF1R and IGFBP5 expression and regulating the Ras/p38 MAPK signaling pathways. Therefore, miR-143-3p may be a novel therapeutic target in RA.

Anti‑inflammatory effects of gambogic acid in murine collagen‑induced arthritis through PI3K/Akt signaling pathway

Garcinia angustifolia is a dry resin secreted by Garcinia cambogia, which has the functions of breaking blood, detoxifying, stopping bleeding and killing insects. It is used for the treatment of cancer and brain edema. Gambogic acid is the primary active ingredient. The present study aimed to investigate the anti‑inflammatory and antiproliferative effects of gambogic acid on arthritis and the possible mechanisms. It was demonstrated that gambogic acid decreased arthritic scores in murine collagen‑induced arthritic mice. The tumor necrosis factor (TNF)‑α, interleukin (IL)‑1β, IL‑6 and IL‑18 concentrations, and caspase‑3 and caspase‑9 were significantly inhibited by gambogic acid in arthritic mice. Gambogic acid decreased matrix metalloproteinases (MMP)‑2, MMP‑9, nuclear factor (NF)‑κB and phosphorylated‑p38 protein expression, and increased tissue inhibitors of matrix metalloproteases‑1 (TIMP‑1) protein expression in arthritic mice. Furthermore, the phosphoinositide 3‑kinase (PI3K)/AKT serine/threonine kinase (Akt) signaling pathway was induced in arthritic mice treated with gambogic acid. The results suggested that gambogic acid induced anti‑inflammatory effects in murine collagen‑induced arthritis, through the PI3K/Akt signaling pathway, and offers future potential for application in arthritis patients.

ASIC2a overexpression enhances the protective effect of PcTx1 and APETx2 against acidosis-induced articular chondrocyte apoptosis and cytotoxicity

Acid hydrarthrosis is another important pathological character in rheumatoid arthritis (RA), and acid-sensing ion channel 1a (ASIC1a) plays a destructive role in acidosis-induced articular chondrocyte cytotoxicity. Recently, ASIC2a has been reported to possess neuroprotective effect on acidosis-induced injury of neuronal cells. However, whether ASIC2a has an enhanced effect on the protective effect of blocking ASIC1a and ASIC3 against acid-induced chondrocyte apoptosis is still unclear. The aim of present study was to investigate the chondroprotective effect of ASIC2a with PcTx1 (ASIC1a specific blocker) and APETx2 (ASIC3 specific blocker) on acidosis-induced chondrocyte apoptosis. Our results revealed that acid (pH 6.0) decreased the cell viability and induced apoptosis of articular chondrocytes. PcTx1 and APETx2 combination significantly attenuated acidosis-induced chondrocyte cytotoxicity due to inhibit apoptosis, and this role could be enhanced by ASIC2a overexpression compared with the PcTx1 and APETx2 combination alone group. Moreover, both the [Ca²⁺]_i levels and the levels of phosphorylated ERK1/2 as well as p38 were further reduced in acidosis-induced chondrocytes after ASIC2a overexpression in the presence of PcTx1 and APETx2. Furthermore, ASIC2a overexpression also reduced acid-induced the expression of ASIC1a. In addition, ASIC2a overexpression further promoted the PcTx1 and APETx2-increased levels of type II collagen in acidosis-induced chondrocytes. Taken together, the current data suggested that ASIC2a overexpression might enhance the anti-apoptotic and protective role of PcTx1 and APETx2 against acid-induced rat articular chondrocyte apoptosis by regulating ASIC1a expression and the [Ca²⁺]_i levels and at least in part, suppressing p38 and ERK1/2 MAPK signaling pathways.

Inhibition of miR-20 promotes proliferation and autophagy in articular chondrocytes by PI3K/AKT/mTOR signaling pathway

Osteoarthritis is a common cause of functional deterioration in older adults and is an immense burden on the aging population. The molecular mechanism underlying the regulation of chondrocyte requires further elucidation, particularly with respect to the role of microRNAs. The aim of this study was to identify and characterize the expression of miR-20 in normal and OA chondrocytes, and to determine its role in OA pathogenesis. MiR-20 expression in cartilage specimens was examined in 30 patients with knee osteoarthritis and 30 traumatic amputees. The effect of miR-20 on chondrocyte was also investigated in chondrocyte cell line. Transfection with miR-20 mimic or inhibitor was employed to investigate the effect of miR-20 on chondrocyte proliferation and autophagy. Cell proliferation activity was detected by MTT assay and clone formation, cell autophagy were evaluated by monodansylcadaverine staining and GFP-LC3 fluorescence microscopy. Western blotting and immunohistochemical were utilized to detect expressions of autophagy markers (LC3, Beclin1 and p62) and of relevant proteins in the PI3K/AKT/mTOR signaling pathway. The results demonstrated that miR-20 inhibit chondrocyte proliferation and autophagy by targeting ATG10 via PI3K/AKT/mTOR signaling pathway. Our data suggest that miR-20 has an important role in the pathogenesis of osteoarthritis and is a potential therapeutic target.

Cucurbitacin E reduces obesity and related metabolic dysfunction in mice by targeting JAK-STAT5 signaling pathway

Several members of cucurbitaceae family have been reported to regulate growth of cancer by interfering with STAT3 signaling. In the present study, we investigated the unique role and molecular mechanism of cucurbitacins (Cucs) in reducing symptoms of metabolic syndrome in mice. Cucurbitacin E (CuE) was found to reduce adipogenesis in murine adipocytes. CuE treatment diminished hypertrophy of adipocytes, visceral obesity and lipogenesis gene expression in diet induced mice model of metabolic syndrome (MetS). CuE also ameliorated adipose tissue dysfunction by reducing hyperleptinemia and TNF-alpha levels and enhancing hypoadiponectinemia. Results show that CuE mediated these effects by attenuating Jenus kinase- Signal transducer and activator of transcription 5 (JAK- STAT5) signaling in visceral fat tissue. As a result, CuE treatment also reduced PPAR gamma expression. Glucose uptake enhanced in adipocytes after stimulation with CuE and insulin resistance diminished in mice treated with CuE, as reflected by reduced glucose intolerance and glucose stimulated insulin secretion. CuE restored insulin sensitivity indirectly by inhibiting JAK phosphorylation and improving AMPK activity. Consequently, insulin signaling was up-regulated in mice muscle. As CuE positively regulated adipose tissue function and suppressed visceral obesity, dyslipedemia, hyperglycemia and insulin resistance in mice model of MetS, we suggest that CuE can be used as novel approach to treat metabolic diseases.

The inflammatory cytokine TNF-α promotes the premature senescence of rat nucleus pulposus cells via the PI3K/Akt signaling pathway

Premature senescence of nucleus pulposus (NP) cells and inflammation are two common features of degenerated discs. This study investigated the effects of the inflammatory cytokine TNF-α on the premature senescence of NP cells and the molecular mechanism behind this process. Rat NP cells were cultured with or without different concentrations of TNF-α for 1 and 3 days. The inhibitor LY294002 was used to determine the role of the PI3K/Akt pathway. NP cells that were incubated with TNF-α for 3 days followed by 3 days of recovery in the control medium were used to analyze cellular senescence. Results showed that TNF-α promoted premature senescence of NP cells, as indicated by decreased cell proliferation, decreased telomerase activity, increased SA-β-gal staining, the fraction of cells arrested in the G1 phase of the cell cycle, the attenuated ability to synthesize matrix proteins and the up-regulated expression of the senescence marker p16 and p53. Moreover, a high TNF-α concentration produced greater effects than a low TNF-α concentration on day 3 of the experiment. Further analysis indicated that the inhibition of the PI3K/Akt pathway attenuated the TNF-α-induced premature senescence of NP cells. Additionally, TNF-α-induced NP cell senescence did not recover after TNF-α was withdrawn. In conclusion, TNF-α promotes the premature senescence of NP cells, and activation of the PI3K/Akt pathway is involved in this process.

Cucurbitacin E inhibits osteosarcoma cells proliferation and invasion through attenuation of PI3K/AKT/mTOR signalling pathway

Cucurbitacin E (CuE), a potent member of triterpenoid family isolated from plants, has been confirmed as an antitumour agent by inhibiting proliferation, migration and metastasis in diverse cancer. However, the effects and mechanisms of CuE on osteosarcoma (OS) have not been well understood. The present study aimed to test whether CuE could inhibit growth and invasion of OS cells and reveal its underlying molecular mechanism. After various concentrations of CuE treatment, the anti-proliferative effect of CuE was assessed using the cell counting Kit-8 assay. Flow cytometry analysis was employed to measure apoptosis of OS cells. Cell cycle distribution was analysed by propidium iodide staining. Transwell assay was performed to evaluate the effect of CuE on invasion potential of OS cells. The protein levels were measured by western blot. In addition, the potency of CuE on OS cells growth inhibition was assessed in vivo Our results showed that CuE inhibited cell growth and invasion, induced a cell cycle arrest and triggered apoptosis and modulated the expression of cell growth, cell cycle and cell apoptosis regulators. Moreover, CuE inhibited the PI3K/Akt/mTOR pathway and epithelial-mesenchymal transition (EMT), which suppressed the invasion and metastasis of OS. In addition, we also found that CuE inhibited OS cell growth in vivo Taken together, our study demonstrated that CuE could inhibit OS tumour growth and invasion through inhibiting the PI3K/Akt/mTOR signalling pathway. Our findings suggest that CuE can be considered to be a promising anti-cancer agent for OS.

Cucurbitacin E Potently Modulates the Activity of Encephalitogenic Cells

Cucurbitacin E (CucE) is a highly oxidized steroid consisting of a tetracyclic triterpene. It is a member of a Cucurbitacin family of biomolecules that are predominantly found in Cucurbitaceae plants. CucE has already been identified as a potent anti-inflammatory compound. Here, its effects on CD4(+) T helper (Th) cells and macrophages, as the major encephalitogenic cells in the autoimmunity of the central nervous system, were investigated. Production of major pathogenic Th cell cytokines: interferon-gamma and interleukin-17 were inhibited under the influence of CucE. The effects of CucE on CD4(+) T cells were mediated through the modulation of aryl hydrocarbon receptor, STAT3, NFκB, p38 MAPK, and miR-146 signaling. Further, production of nitric oxide and reactive oxygen species, as well as phagocytic ability, were inhibited in macrophages treated with CucE. These results imply that CucE possesses powerful antiencephalitogenic activity.