Triptolide Modulates TREM-1 Signal Pathway to Inhibit the Inflammatory Response in Rheumatoid Arthritis

Single-Cell RNA Sequencing Reveals Transcriptional Landscape of Neutrophils and Highlights the Role of TREM-1 in EAE

BACKGROUND AND OBJECTIVES

Neutrophils, underestimated in multiple sclerosis (MS), are gaining increased attention for their significant functions in patients with MS and the experimental autoimmune encephalomyelitis (EAE) animal model. However, the precise role of neutrophils in cervical lymph nodes (CLNs), the primary CNS-draining lymph nodes where the autoimmune response is initiated during the progression of EAE, remains poorly understood.

METHODS

Applying single-cell RNA sequencing (scRNA-seq), we constructed a comprehensive immune cell atlas of CLNs during development of EAE. Through this atlas, we concentrated on and uncovered the transcriptional landscape, phenotypic and functional heterogeneity of neutrophils, and their crosstalk with immune cells within CLNs in the neuroinflammatory processes in EAE.

RESULTS

Notably, we observed a substantial increase in the neutrophil population in EAE mice, with a particular emphasis on the significant rise within the CLNs. Neutrophils in CLNs were categorized into 3 subtypes, and we explored the specific roles and developmental trajectories of each distinct neutrophil subtype. Neutrophils were found to engage in extensive interactions with other immune cells, playing crucial roles in T-cell activation. Moreover, our findings highlighted the strong migratory ability of neutrophils to CLNs, partly regulated by triggering the receptor expressed on myeloid cells 1 (TREM-1). Inhibiting TREM1 with LR12 prevents neutrophil migration both in vivo and in vitro. In addition, in patients with MS, we confirmed an increase in peripheral neutrophils with an upregulation of TREM-1.

DISCUSSION

Our research provides a comprehensive and precise single-cell atlas of CLNs in EAE, highlighting the role of neutrophils in regulating the periphery immune response. In addition, TREM-1 emerged as an essential regulator of neutrophil migration to CLNs, holding promise as a potential therapeutic target in MS.

TREM1: Activation, signaling, cancer and therapy

Triggering receptor expressed on myeloid cells 1 (TREM1) is a cell surface receptor expressed on neutrophils, monocytes and some tissue macrophages, where it functions as an immunoregulator that controls myeloid cell responses. The activation of TREM1 is suggested to be an upregulation-based, ligands-induced and structural multimerization-mediated process, in which damage- and pathogen-associated molecular patterns play important roles. Activated TREM1 initiates an array of downstream signaling pathways that ultimately result in the production of pro-inflammatory cytokines and chemokines, whereby it functions as an amplifier of inflammation and is implicated in the pathogenesis of many inflammation-associated diseases. Over the past decade, there has been growing evidence for the involvement of TREM1 overactivation in tumor stroma inflammation and cancer progression. Indeed, it was shown that TREM1 promotes tumor progression, immunosuppression, and resistance to therapy by activating tumor-infiltrating myeloid cells. TREM1-deficiency or blockade provide protection against tumors and reverse the resistance to anti-PD-1/PD-L1 therapy and arginine-deprivation therapy in preclinical models. Here, we first review the structure, activation modes and signaling pathways of TREM1 and emphasize the role of soluble TREM1 as a biomarker of infection and cancer. We then focus on the role of TREM1 in cancer and systematically summarize its expression patterns, upregulation mechanisms and functions in tumor development and progression. Lastly, we discuss the therapeutic prospects of TREM1 inhibition, via effective pharmacological inhibitors, in treating cancer and other diseases.

Mechanisms of Tripterygium wilfordii Hook F on treating rheumatoid arthritis explored by network pharmacology analysis and molecular docking

Background

Rheumatoid arthritis (RA) is a chronic inflammatory and disabling disease that imposes significant economic and social costs. Tripterygium wilfordii Hook F (TwHF) has a long history of use in traditional Chinese medicine for treating joint disorders, and it has been shown to be cost-effective in treating RA, but its exact mechanism is unknown.

Objective

The goal of the network pharmacology analysis and molecular docking was to investigate the potential active compounds and associated anti-RA mechanisms of TwHF.

Methods

TCMSP and UniProt databases were searched for active compounds and related targets of TwHF. PharmGKB, DrugBank, OMIM, TTD, and the Human Gene Databases were used to identify RA-related targets. The intersected RA and TwHF targets were entered into the STRING database to create a protein-protein interaction network. R software was used for gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. Molecular docking technology was used to analyze the optimal effective components from TwHF for docking with the selected target gene.

Results

Following screening and duplicate removal, a total of 51 active compounds and 96 potential targets were chosen. The PPI network revealed that the target proteins are CXCL8, CXCL6, STAT3, STAT1, JUN, PPARG, TP53, IL14, MMP9, VEGFA, RELA, CASP3, PTGS2, IFNG, AKT1, FOS, ICAM1, and MAPK14. The results of the GO enrichment analysis focused primarily on the response to lipopolysaccharide, the response to molecules of bacterial origin, and the response to drugs. The KEGG results indicated that the mechanisms were closely related to lipid and atherosclerosis, chemical carcinogenesis-receptor activation, Kaposi sarcoma-associated, herpesvirus infection, hepatitis B, fluid shear stress and atherosclerosis, IL-17 signaling pathways, Th17-cell differentiation, and so on, all of which are involved in angiogenesis, immune cell chemotaxis, and inflammatory responses. Molecular docking results suggested that triptolide was the appropriate PTGS1, PTGS2, and TNF inhibitors.

Conclusion

Our findings provide an essential role and basis for further immune inflammatory studies into the molecular mechanisms of TwHF and PTGS1, PTGS2, and TNF inhibitor development in RA.

Hypoxia-induced ALKBH5 aggravates synovial aggression and inflammation in rheumatoid arthritis by regulating the m6A modification of CH25H

Previous studies have shown that epigenetic factors are involved in the occurrence and development of rheumatoid arthritis (RA). However, the role of N6-methyladenosine (m6A) methylation in RA has not been determined. The aim of this study was to investigate the role and regulatory mechanisms of hypoxia-induced expression of the m6A demethylase alkB homolog 5 (ALKBH5) in RA fibroblast-like synoviocytes (FLSs). Synovial tissues were collected from RA and osteoarthritis (OA) patients, and RA FLSs were obtained. ALKBH5 expression in RA FLSs and collagen-induced arthritis (CIA) model rats was determined using quantitative reverse transcription-PCR (qRT-PCR), western blotting and immunohistochemistry (IHC). Using ALKBH5 overexpression and knockdown, we determined the role of ALKBH5 in RA FLS aggression and inflammation. The role of ALKBH5 in RA FLS regulation was explored using m6A-methylated RNA sequencing and methylated RNA immunoprecipitation coupled with quantitative real-time PCR. The expression of ALKBH5 was increased in RA synovial tissues, CIA model rats and RA FLSs, and a hypoxic environment increased the expression of ALKBH5 in FLSs. Increased expression of ALKBH5 promoted the proliferation and migration of RA-FLSs and inflammation. Conversely, decreased ALKBH5 expression inhibited the migration of RA-FLSs and inflammation. Mechanistically, hypoxia-induced ALKBH5 expression promoted FLS aggression and inflammation by regulating CH25H mRNA stability. Our study elucidated the functional roles of ALKBH5 and mRNA m6A methylation in RA and revealed that the HIF1α/2α-ALKBH5-CH25H pathway may be key for FLS aggression and inflammation. This study provides a novel approach for the treatment of RA by targeting the HIF1α/2α-ALKBH5-CH25H pathway.

Triptolide mitigates the inhibition of osteogenesis induced by TNF-α in human periodontal ligament stem cells via the p-IκBα/NF-κB signaling pathway: an in-vitro study

BACKGROUND

Triptolide is a widely utilized natural anti-inflammatory drug in clinical practice. Aim of this study was to evaluate effects of triptolide on hPDLSCs osteogenesis in an inflammatory setting and to investigate underlying mechanisms.

METHODS

Using the tissue block method to obtain hPDLSCs from extracted premolar or third molar. Flow cytometry, osteogenic and adipogenic induction were carried out in order to characterise the features of the cells acquired. hPDLSC proliferative activity was assessed by CCK-8 assay to determine the effect of TNF-α and/or triptolide. The impact of triptolide on the osteogenic differentiation of hPDLSCs was investigated by ALP staining and quantification. Osteogenesis-associated genes and proteins expression level were assessed through PCR and Western blotting assay. Finally, BAY-117,082 was used to study the NF-κB pathway.

RESULTS

In the group treated with TNF-α, there was an elevation in inflammation levels while osteogenic ability and the expression of both osteogenesis-associated genes and proteins decreased. In the group co-treated with TNF-α and triptolide, inflammation levels were reduced and osteogenic ability as well as the expression of both osteogenesis-associated genes and proteins were enhanced. At the end of the experiment, both triptolide and BAY-117,082 exerted similar inhibitory effects on the NF-κB pathway.

CONCLUSION

The osteogenic inhibition of hPDLSCs by TNF-α can be alleviated through triptolide, with the involvement of the p-IκBα/NF-κB pathway in this mechanism.

Rheumatoid arthritis-recent advances in pathogenesis and the anti-inflammatory effect of plant-derived COX inhibitors

The majority of people with autoimmune disorders, including those with rheumatoid arthritis, osteoarthritis, and tendonitis report pain, stiffness, and inflammation as major contributors to their worse quality of life in terms of overall health. Of all the available treatment options, COX inhibitors are the ones that are utilized most frequently to ease the symptoms. Various signaling cascades have been reported to be involved in the pathogenesis of rheumatoid arthritis which includes JAK/STAT, MAPK, and NF-kB signaling pathways, and several allopathic inhibitors (tofacitinib and baricitinib) have been reported to target the components of these cascades and have received approval for RA treatment. However, the prolonged use of these COX inhibitors and other allopathic drugs can pose serious health challenges due to their significant side effects. Therefore, searching for a more effective and side effect-free treatment for rheumatoid arthritis has unveiled phytochemicals as both productive and promising. Their therapeutic ability helps develop potent and safe drugs targeting immune-inflammatory diseases including RA. Various scientific databases were used for searching articles such as NCBI, SpringerLink, BioMed Central, ResearchGate, Google Scholar, Scopus, Nature, Wiley Online Library, and ScienceDirect. This review lists various phytochemicals and discusses their potential molecular targets in RA treatment, as demonstrated by various in vitro, in vivo (pre-clinical), and clinical studies. Several pre-clinical and clinical studies suggest that various phytochemicals can be an alternative promising intervention for attenuating and managing inflammation-associated pathogenesis of rheumatoid arthritis.

Therapeutic potential of natural products in inflammation: underlying molecular mechanisms, clinical outcomes, technological advances, and future perspectives

Chronic inflammation is a common underlying factor in many major diseases, including heart disease, diabetes, cancer, and autoimmune disorders, and is responsible for up to 60% of all deaths worldwide. Metformin, statins, and corticosteroids, and NSAIDs (non-steroidal anti-inflammatory drugs) are often given as anti-inflammatory pharmaceuticals, however, often have even more debilitating side effects than the illness itself. The natural product-based therapy of inflammation-related diseases has no adverse effects and good beneficial results compared to substitute conventional anti-inflammatory medications. In this review article, we provide a concise overview of present pharmacological treatments, the pathophysiology of inflammation, and the signaling pathways that underlie it. In addition, we focus on the most promising natural products identified as potential anti-inflammatory therapeutic agents. Moreover, preclinical studies and clinical trials evaluating the efficacy of natural products as anti-inflammatory therapeutic agents and their pragmatic applications with promising outcomes are reviewed. In addition, the safety, side effects and technical barriers of natural products are discussed. Furthermore, we also summarized the latest technological advances in the discovery and scientific development of natural products-based medicine.

Network pharmacological analysis to reveal the mechanism governing the effect of Qin Xi Tong on osteoarthritis and rheumatoid arthritis

INTRODUCTION

Qin Xi Tong (QXT), produced by water extracts of Caulis Sinomenii, is clinically effective in the therapy of rheumatoid arthritis (RA). It is also a complementary agent for osteoarthritis (OA). This study aimed to screen the candidate targets and identify the potential mechanisms of QXT against RA and OA.

METHOD

The active ingredients contained in QXT were queried from the TCMSP database. Their predicted targets were obtained through web-based databases, including TCMSP, BATMAN-TCM, CTD, and PharmMapper. The OA and RA targets were collected from the Genecards database and the GSE55235 dataset. Based on the DAVID database, GO and KEGG enrichment analyses of disease-drug common targets predicted potential signaling pathways for QXT. In addition, core targets were identified by mapping component-target-disease interaction networks with Cytoscape 3.9.1 and STRING. The Swissdock and Pymol tools further validate the predicted results.

RESULTS

A total of 161 genes were put forward as potential targets for treating RA and OA. These genes might be involved in joint inflammation, including the IL-17 signaling pathway, MAPK signaling pathway, and TNF signaling pathway. They also regulated the progression of joint injuries, such as apoptosis, Th17 cell differentiation, and osteoclast differentiation. In addition, we identified 12 core targets of QXT. Molecular docking results showed that QXT has a high affinity with these core targets.

CONCLUSIONS

This study reveals the mechanism governing the effect of QXT on RA and OA, predicts the direct target, and provides new ideas for clinical treatment. Key Points • Our study reveals the underlying mechanism of QXT in the treatment of RA and OA. • Further research into the effects of compounds in QXT alone would be of interest.

Triptolide alleviates collagen-induced arthritis in mice by modulating Treg/Th17 imbalance through the JAK/PTEN-STAT3 pathway

BACKGROUND

This study aimed to investigate the effects of triptolide (TP) on collagen-induced arthritis (CIA) mice and the related mechanisms.

METHODS

CIA mice were administered TP for 35 days. Mouse ankle joints and serum antibodies and cytokines were examined to assess the therapeutic effects of TP. The ratios of Treg, Th1, and Th17 cells were measured by flow cytometry and RT-qPCR. Reverse docking was used to characterize the binding modes of TP against target proteins. The expression of the STAT3 pathway in CIA mice was evaluated by western blotting and immunofluorescence staining. Mouse spleen lymphocytes were extracted and the expression of the STAT3 pathway after IL-6 stimulation was analyzed.

RESULTS

TP could significantly alleviate joint swelling, reduce bone destruction, and downregulate serum inflammation levels. TP improved the imbalance of Treg/Th17 cells in CIA mice. TP could form stable complexes with target proteins. TP significantly inhibited the activation of the JAK/PTEN-STAT3 pathway in mice. Moreover, TP regulated the activation of the JAK1/2-STAT3 signaling pathway in mouse spleen lymphocytes under inflammatory stimulation.

CONCLUSION

TP can inhibit inflammation and alleviate bone destruction in CIA mice. The underlying mechanism is related to the regulation of the imbalance of Treg/Th17 cells through the JAK/PTEN-STAT3 pathway.

Identification of Novel Core Genes Involved in Malignant Transformation of Inflamed Colon Tissue Using a Computational Biology Approach and Verification in Murine Models

Inflammatory bowel disease (IBD) is a complex and multifactorial systemic disorder of the gastrointestinal tract and is strongly associated with the development of colorectal cancer. Despite extensive studies of IBD pathogenesis, the molecular mechanism of colitis-driven tumorigenesis is not yet fully understood. In the current animal-based study, we report a comprehensive bioinformatics analysis of multiple transcriptomics datasets from the colon tissue of mice with acute colitis and colitis-associated cancer (CAC). We performed intersection of differentially expressed genes (DEGs), their functional annotation, reconstruction, and topology analysis of gene association networks, which, when combined with the text mining approach, revealed that a set of key overexpressed genes involved in the regulation of colitis (C3, Tyrobp, Mmp3, Mmp9, Timp1) and CAC (Timp1, Adam8, Mmp7, Mmp13) occupied hub positions within explored colitis- and CAC-related regulomes. Further validation of obtained data in murine models of dextran sulfate sodium (DSS)-induced colitis and azoxymethane/DSS-stimulated CAC fully confirmed the association of revealed hub genes with inflammatory and malignant lesions of colon tissue and demonstrated that genes encoding matrix metalloproteinases (acute colitis: Mmp3, Mmp9; CAC: Mmp7, Mmp13) can be used as a novel prognostic signature for colorectal neoplasia in IBD. Finally, using publicly available transcriptomics data, translational bridge interconnecting of listed colitis/CAC-associated core genes with the pathogenesis of ulcerative colitis, Crohn's disease, and colorectal cancer in humans was identified. Taken together, a set of key genes playing a core function in colon inflammation and CAC was revealed, which can serve both as promising molecular markers and therapeutic targets to control IBD and IBD-associated colorectal neoplasia.

The Anti-Inflammatory and Immunomodulatory Activities of Natural Products to Control Autoimmune Inflammation

Inflammation is an integral part of autoimmune diseases, which are caused by dysregulation of the immune system. This dysregulation involves an imbalance between pro-inflammatory versus anti-inflammatory mediators. These mediators include various cytokines and chemokines; defined subsets of T helper/T regulatory cells, M1/M2 macrophages, activating/tolerogenic dendritic cells, and antibody-producing/regulatory B cells. Despite the availability of many anti-inflammatory/immunomodulatory drugs, the severe adverse reactions associated with their long-term use and often their high costs are impediments in effectively controlling the disease process. Accordingly, suitable alternatives are being sought for these conventional drugs. Natural products offer promising adjuncts/alternatives in this regard. The availability of specific compounds isolated from dietary/medicinal plant extracts have permitted rigorous studies on their disease-modulating activities and the mechanisms involved therein. Here, we describe the basic characteristics, mechanisms of action, and preventive/therapeutic applications of 5 well-characterized natural product compounds (Resveratrol, Curcumin, Boswellic acids, Epigallocatechin-3-gallate, and Triptolide). These compounds have been tested extensively in animal models of autoimmunity as well as in limited clinical trials in patients having the corresponding diseases. We have focused our description on predominantly T cell-mediated diseases, such as rheumatoid arthritis, multiple sclerosis, Type 1 diabetes, ulcerative colitis, and psoriasis.

Triptolide inhibits Th17 differentiation via controlling PKM2-mediated glycolysis in rheumatoid arthritis

CONTEXT

Rheumatoid arthritis (RA) is an autoimmune disease with the aberrant differentiation of T helper 17 (Th17) cells. Pyruvate kinase M2 (PKM2), a key enzyme of glycolysis, was associated with Th17 cell differentiation.

AIM

To investigate the potential therapeutic effects of triptolide (TP) in collagen-induced arthritis (CIA) and Th17 cell differentiation, and elucidated the underlying mechanisms.

METHODS

PKM2 expression and IL-17A production in peripheral blood of RA patients were detected by RT-qPCR or ELISA. Flow cytometry and ELISA were employed to assess the effect of Th17 cell differentiation by TP. PKM2 expression and other glycolysis-related factors were detected using RT-qPCR and Western Blot. PKM2 specific inhibitor Compound 3 K was used to verify the mechanisms. Male DBA/1J mice were divided into control, model, and TP (60 μg/kg) groups to assess the anti-arthritis effect, Th17 cell differentiation and PKM2 expression.

RESULTS

PKM2 expression positively correlated with IL-17A production in RA patients. PKM2 expression was increased upon Th17 cell differentiation. Down-regulating PKM2 expression could strongly reduce Th17 cell differentiation. Molecular docking analysis predicted that TP targeted PKM2. TP treatment significantly reduced Th17 cell differentiation, PKM2 expression, pyruvate, and lactate production. In addition, compared with down-regulating PKM2 alone (Compound 3 K treatment), co-treatment with TP and Compound 3 K further significantly decreased PKM2-mediated glycolysis and Th17 cell differentiation. In CIA mice, TP repressed the PKM2-mediated glycolysis and attenuated joint inflammation.

CONCLUSION

TP inhibited Th17 cell differentiation through the inhibition of PKM2-mediated glycolysis. We highlight a novel strategy for the use of TP in RA treatment.

The mechanism of triptolide in the treatment of connective tissue disease-related interstitial lung disease based on network pharmacology and molecular docking

BACKGROUND

Interstitial lung disease (ILD) is associated with substantial morbidity and mortality, which is one of the key systematic manifestations of connective tissue disease (CTD). Tripterygium wilfordii, known as Leigongteng in Chinese, has been applied to treat connective tissue disease-related interstitial lung disease (CTD-ILD) for many years. Triptolide is a key effective component from Tripterygium wilfordii. But the molecular mechanism of Triptolide for treating CTD-ILD is not yet clear.

METHODS

Gaining insight into the molecular mechanism of Triptolide intervention CTD-ILD, we used the method of network pharmacology. And then we conducted drug-target networks to analyse the potential protein targets between Triptolide and CTD-ILD. Finally, AutoDock Vina was selected for molecular docking.

RESULTS

By analysing the interaction genes between Triptolide and CTD-ILD, 242 genes were obtained. The top 10 targets of the highest enrichment scores were STAT3, AKT1, MAPK1, IL6, TP53, MAPK3, RELA, TNF, JUN, JAK2. GO and KEGG enrichment analysis exhibited that multiple signalling pathways were involved. PI3K-Akt, multiple virus infections, cancer signalling, chemokine, and apoptosis signalling pathway are the main pathways for Triptolide intervention CTD-ILD. And it is related to various biological processes such as inflammation, infection, cell apoptosis, and cancer. Molecular docking shows Triptolide can bind with its target protein in a good bond by intermolecular force.

CONCLUSIONS

This study preliminarily reveals the internal molecular mechanism of Triptolide interfere with CTD-ILD through multiple targets, multiple access, validated through molecular docking.KEY MESSAGESTriptolide intervention CTD-ILD, which are related to various biological processes such as inflammation, infection, cell apoptosis, and cancer.PI3K-Akt, multiple virus infections, and apoptosis signalling pathway are the main pathways for Triptolide intervention CTD-ILD.Triptolide can bind with related target protein in a good bond by Intermolecular force, exhibiting a good docking activity.

Inhibitory effects of traditional Chinese medicine colquhounia root tablet on the pharmacokinetics of tacrolimus in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Tacrolimus (TAC) was widely used in various renal diseases while high recurrence rate and high expense restricted its applications. Traditional herbal medicine has become increasingly popular as an adjuvant therapy to minimize the adverse effects of TAC. Colquhounia root tablet (CRT), a prescribed drug prepared from the water extract of the peeled root of Tripterygium hypoglaucum (H. Lév.) Hutch., showed excellent anti-inflammatory, analgesic and immunosuppressive pharmacological properties. TAC used in combination with CRT was substantially more efficacious and safer than the monotherapy for the treatment of nephrotic syndrome. However, studies on their herb-drug interaction were scanty.

AIM OF THE STUDY

The study was proposed to examine the effect of CRT on the pharmacokinetics of TAC in rats and identify the key natural constituents in CRT that affected the metabolism of TAC.

MATERIALS AND METHODS

TAC was orally and intravenously administered to rats alone or in combination with CRT and the pharmacokinetic parameters of TAC were compared. After pretreatment with CRT for 15 d, the expressions of the drug-metabolizing enzymes (DMEs), drug transporters (DTs) and nuclear receptors (NRs) were determined by polymerase chain reaction and western blotting and compared with the control group. The hepatic microsomal incubation system was employed to confirm the inhibitory effects of CRT and its major components on rat cytochrome P450 (CYP) 3A2. The roles of the primary components in the regulation of human CYP3A4 and mouse P-gp activities were evaluated by using docking analysis.

RESULTS

The blood concentrations of TAC were significantly increased in a dose- and pretreatment time-dependent manner after combined administration of CRT. The maximal effect was found at 300 mg/kg (43.70 ± 8.77 ng/mL and 141.45 ± 21.58 h·ng/mL) in a single dose run and the pharmacokinetic parameters gradually returned to the normal levels at 24 h interval of long-term CRT pretreatment. In contrast, CRT had no effect on the pharmacokinetics of intravenous TAC. Further study indicated that the mRNA and protein expressions of DMEs and DTs, such as CYP3A1, CYP3A2, P-glycoprotein (P-gp) and multidrug resistance-associated protein 2 in rat intestine and liver were down-regulated, whereas the expressions of NRs like constitutive androstane receptor and pregnane X receptor were up-regulated after multiple oral doses of CRT. Molecular docking showed the binding potency of five CRT major constituents with both human CYP3A4 and mouse P-gp. Celastrol, wilforgine and wilforine were the strongest inhibitors towards midazolam metabolism in rat liver microsomes, with the 50% inhibition concentrations being at 8.33 μM, 22.18 μM and 22.22 μM, respectively.

CONCLUSIONS

Our results revealed that co-dosing of CRT could lead to a significant increase in blood concentration of TAC and this effect could be ascribed to the resultant co-regulation of DMEs, DTs and NRs. Our study provided an experimental basis for the combination use of CRT and TAC in clinical practice.

Inhibition of TREM-2 Markedly Suppresses Joint Inflammation and Damage in Experimental Arthritis

The triggering receptors expressed on myeloid cells (TREMs) are a family of activating immune receptors that regulate the inflammatory response. TREM-1, which is expressed on monocytes and/or macrophages and neutrophils, functions as an inflammation amplifier and plays a role in the pathogenesis of rheumatoid arthritis (RA). Unlike TREM-1, the role in RA of TREM-2, which is expressed on macrophages, immature monocyte-derived dendritic cells, osteoclasts, and microglia, remains unclear and controversial. TREM-2 ligands are still unknown, adding further uncertainty to our understanding of TREM-2 function. Previously, we demonstrated that TREM-1 blockade, using a ligand-independent TREM-1 inhibitory peptide sequence GF9 rationally designed by our signaling chain homooligomerization (SCHOOL) model of cell signaling, ameliorates collagen-induced arthritis (CIA) severity in mice. Here, we designed a TREM-2 inhibitory peptide sequence IA9 and tested it in the therapeutic CIA model, either as a free 9-mer peptide IA9, or as a part of a 31-mer peptide IA31 incorporated into lipopeptide complexes (IA31-LPC), for targeted delivery. We demonstrated that administration of IA9, but not a control peptide, after induction of arthritis diminished release of proinflammatory cytokines and dramatically suppressed joint inflammation and damage, suggesting that targeting TREM-2 may be a promising approach for the treatment of RA.

Therapeutic Potential of Triptolide in Treating Bone-Related Disorders

Triptolide, a diterpene triepoxide, is a pharmacologically active compound isolated from a Chinese medicinal herb Tripterygium wilfordii Hook F (TwHF). Triptolide has attracted considerable attention in recent times due to its multiple biological and pharmaceutical activities, with an emphasis on therapeutic importance in the treatment of diverse disorders. With essential medicinal implications, TwHF’s extracts have been used as anti-inflammatory, antiproliferative, antioxidative, and immunosuppressive agents for centuries, with continuous and relevant modifications to date to enhance its utility in several diseases and pathophysiology. Here, in this review, we accentuate the studies, highlighting the effects of triptolide on treating bone-related disorders, both inflammatory and cancerous, particularly osteosarcoma, and their manifestations. Based on this review, future avenues could be estimated for potential research strategies, molecular mechanisms, and outcomes that might contribute toward reinforcing new dimensions in the clinical application of triptolide in treating bone-related disorders.

TREM-1 Modulates Dendritic Cells Maturation and Dendritic Cell-Mediated T-Cell Activation Induced by ox-LDL

Atherosclerosis is a chronic inflammatory disease. The triggering receptor expressed on myeloid cells-1 (TREM-1) plays a crucial role in inflammatory diseases; recently, it was identified as a major upstream proatherogenic receptor, but its mechanism is still unclear. In this study, we explore the role of TREM-1 on dendritic cells maturation and inflammatory responses induced by ox-LDL and its possible mechanism. Human dendritic cells were differentiated from blood monocytes and treated with ox-LDL. Naive autologous T cells were cocultured with pretreated DCs or treated directly. The expression of TREM-1 and inflammatory factors were evaluated by real-time PCR, western blot, and ELISA methods. And the expression of immune factors to evaluate the DCs maturation and T-cell activation were determined by the FACS. Our study showed that ox-LDL induced TREM-1 expression, DC maturation, and T-cell activation. T cells exposed to ox-LDL-treated DCs produced interferon-γ and interleukin-17 (IL-17). Blocking TREM-1 suppressed the DC maturation, showing lower expression of CD1a, CD40, CD86, CD83, and HLA-DR, and limited their production of tumor necrosis factor-alpha (TNF-α), IL-1β, IL-6, and monocyte chemoattractant protein-1 (MCP-1), meanwhile increased transforming growth factor-β(TGF-β) and IL-10 production. Ox-LDL induced miR-155, miR-27, Let-7c, and miR-185 expression; however, TREM-1 inhibiting decreased miRNA-155 expression. Furthermore, silencing miRNA-155 restores SOCS1 repression induced by ox-LDL. Experiments with T cells derived from carotid atherosclerotic plaques or healthy individuals showed similar results. Our results uncover a new link between ox-LDL and TREM-1 and may provide insight into this interaction in the context of atherosclerosis.

Macrophage targeted triptolide micelles capable of cGAS-STING pathway inhibition for rheumatoid arthritis treatment

The abundant M1 macrophages in the joint synovium were the main factors that exacerbate rheumatoid arthritis (RA) by secreting various types of inflammatory cytokines. Here, we note that cGAS-STING, an important pro-inflammatory pathway, was significantly up-regulated in RA, enabling it be the potential target for RA therapy. Therefore, in this work, we developed M1 macrophages targeted micelles capable of cGAS-STING pathway inhibition for the smart treatment of RA. The folic acid (FA) and lauric acid (LA) were modified on dextran to obtain an amphiphilic polymer (FDL). Then, FDL was subsequently applied to encapsulate triptolide (TP) to form FDL@TP nanomicelles. The FDL@TP could target the joint and enhance the cell uptake of TP by M1 macrophages (overexpressing folate receptor-β), which also reduced the side effects of TP on normal tissues. In M1 macrophages, the released TP, acted as an anti-inflammatory and immunosuppressant, obviously down-regulated the expressions of cGAS and STING protein, and thus reduced the secretion of TNF-α, IL-1β, and IL-6. Importantly, compared with the same dose of free TP, FDL@TP could significantly enhance the anti-inflammatory effect. Therefore, FDL@TP nanomicelles were believed to be superior candidates for the clinical treatment of RA.

Potential Target Analysis of Triptolide Based on Transcriptome-Wide m6A Methylome in Rheumatoid Arthritis

Triptolide (TP), a major active component of the herb Tripterygium wilfordii Hook F (TwHF), has been shown to exert therapeutic potential against rheumatoid arthritis (RA). However, its molecular mechanism of action has not been fully elucidated. This study aimed to analyze the potential target of TP based on the discovery of differentially methylated and expressed genes (DMEGs) in RA using methylated RNA immunoprecipitation sequencing (MeRIP-seq) and RNA sequencing (RNA-seq). Five RA samples and ten control samples were obtained from China-Japan Friendship Hospital. The various levels of m⁶A methylation and genes expressed in the RA and control groups were compared by MeRIP-seq and RNA-seq. Bioinformatics explorations were also performed to explore the enriched biological roles and paths of the differentially expressed m⁶A methylation and genes. Molecular networks between TP target proteins and DMEGs were performed using Ingenuity Pathway Analysis (IPA) software. Potential target of TP was determined with Gene Expression Omnibus (GEO) database mining, molecular docking, and in vitro experiment validation. In total, 583 dysregulated m⁶A peaks, of which 295 were greatly upregulated and 288 were greatly downregulated, were identified. Similarly, 1,570 differentially expressed genes were identified by RNA-seq, including 539 upregulated and 1,031 downregulated genes. According to the deeper joint exploration, the m⁶A methylation and mRNA expression degrees of 35 genes varied greatly. Molecular networks between TP target proteins and DMEGs were constructed, and the results revealed that tubulin beta-2A chain (TUBB2A), insulin-like growth factor 2 mRNA-binding protein 3 (IGF2BP3), cytoplasmic dynein 1 intermediate chain 1 (DYNC1I1), and FOS-like 1 (FOSL1) were the most relevant genes that correlated with the target proteins of TP. The results of the GEO database showed that the gene expression of IGF2BP3 was increased in RA synovial tissue and consistent with the trend of our sequencing results of RA PBMCs. Molecular docking and in vitro experiment suggested that TP and IGF2BP3 had a high binding affinity and TP could decrease the mRNA expression of IGF2BP3 in PBMCs and MH7A.This research established a transcriptional map of m⁶A in RA PBMCs and displayed the hidden association between RNA methylation alterations and associated genes in RA. IGF2BP3 might be a potential therapeutic target of TP during RA treatment.

Activities and Molecular Mechanisms of Diterpenes, Diterpenoids, and Their Derivatives in Rheumatoid Arthritis

Diterpenes and their derivatives have many biological activities, including anti-inflammatory and immunomodulatory effects. To date, several diterpenes, diterpenoids, and their laboratory-derived products have been demonstrated for antiarthritic activities. This study summarizes the literature about diterpenes and their derivatives acting against rheumatoid arthritis (RA) depending on the database reports until 31 August 2021. For this, we have conducted an extensive search in databases such as PubMed, Science Direct, Google Scholar, and Clinicaltrials.gov using specific relevant keywords. The search yielded 2708 published records, among which 48 have been included in this study. The findings offer several potential diterpenes and their derivatives as anti-RA in various test models. Among the diterpenes and their derivatives, andrographolide, triptolide, and tanshinone IIA have been found to exhibit anti-RA activity through diverse pathways. In addition, some important derivatives of triptolide and tanshinone IIA have also been shown to have anti-RA effects. Overall, findings suggest that these substances could reduce arthritis score, downregulate oxidative, proinflammatory, and inflammatory biomarkers, modulate various arthritis pathways, and improve joint destruction and clinical arthritic conditions, signs, symptoms, and physical functions in humans and numerous experimental animals, mainly through cytokine and chemokine as well as several physiological protein interaction pathways. Taken all together, diterpenes, diterpenoids, and their derivatives may be promising tools for RA management.

Mechanism of Xinfeng Capsule in the Treatment of Hypercoagulable State of Ankylosing Spondylitis Based on Data Mining and Network Pharmacology

Background

Ankylosing spondylitis (AS) is a rheumatism that mainly affects the axial bones and joints. Xinfeng capsule (XFC) is a preparation with a remarkable clinical effect that is used in our hospital. And it has definite curative effect and less side effects in the treatment of AS.

Objective

Data mining and network pharmacology were used to analyze the efficacy of Chinese medicine Xinfeng capsule on treating the hypercoagulable state of ankylosing spondylitis and the underlying mechanism behind it.

Methods

Clinical data were collected and compiled from the Department of Rheumatology and Immunology of the First Affiliated Hospital of Anhui University of Chinese Medicine. Cluster analysis was used to investigate herbs that frequently used to treat AS, Apriori module was used to analyze the association rules between herbs and laboratory indexes, and the random walk model was used to reveal the therapeutic efficacy of XFC against AS. The TCMSP database was used to acquire the active components and targets of XFC, and the GeneCards and OMIM database were used to obtain the targets of AS. Afterward, an active ingredient-target network was established and core targets were screened for; overlapping targets were screened for the protein-protein interaction (PPI) network analysis, the Gene Ontology (GO) enrichment analysis, and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Molecular docking was adopted to investigate the interactions between main active components and core targets.

Results

Frequently used herbs could be divided into three groups, and according to the analysis of Apriori module, there is a strong correlation between XFC and the improvement of ESR and hs-CRP, and the results of the random walk model demonstrated that the effect of XFC on improving PLT, ESR, and hs-CRP was superior to the use of traditional Chinese medicine alone. In total, 103 active compounds of XFC and 59 overlapping targets were obtained. The PPI relationships were obtained through the STRING database, and 13 core targets were identified. 1786 GO enrichment results and 205 KEGG enrichment results were obtained, including NF-kappa B signaling pathway, TNF signaling pathway, and IL17 signaling pathway. The outcomes of molecular docking revealed a close relationship between the active compounds of XFC and core targets.

Conclusion

This study demonstrated that XFC can effectively improve the hypercoagulable state and the inflammatory indices of AS patients through data mining, and it has a strong correlation with the clinical improvement of inflammation. The active compounds of formononetin, triptolide, quercetin, and kaempferol may be the key active components of XFC in regulating AS, possibly through inhibiting the activation of NF-kappa B signaling pathway to improve hypercoagulable state.

Ultrasound Guided Intra-Articular Injection of Triptolide-loaded Solid Lipid Nanoparticle for Treatment of Antigen-Induced Arthritis in Rabbits

Objective: To evaluate the efficacy of ultrasound-guided intra-articular injection of triptolide-loaded solid lipid nanoparticle (TP-SLN) for treatment of antigen-induced arthritis (AIA) in rabbits.

Material and Methods: Knee joints of 33 New Zealand rabbits with AIA were injected intra-articularly with triptolide (TP: n = 7), TP-SLN (n = 7), betamethasone (BS: n = 7) and dimethyl sulfoxide (DMSO: n = 6). The remaining six rabbits were untreated as the control group. The injection therapy in intervention groups was initiated 1 week after the last immunization in order to avoid irreversible joint damage in the later induction. The ultrasonic scores of the joints were assessed based on synovitis, synovial blood flow and bone erosion. Meanwhile, the correlations of ultrasonic scores and pathological scores were determined. The efficacy and side effects of each group were determined by combining ultrasonic scores, pathological scores, behavior, appetite, weight, joint diameter, skin temperature and biochemical examination.

Results: 1) Compared with the control group, the diameters of knee joints of the TP, TP-SLN and BS groups began to reduce 1 week after intra-articular injection (p < 0.01). 2) With the exception of the DMSO group, the interventions were effective in treating synovitis compared with the control group, with TP-SLN and BS being the best. The ultrasonic and pathological scores in synovitis of the TP group were lower than that of model group (Z = -2.726 and -2.530, p < 0.05). The ultrasonic scores differed significantly between BS group and TP-SLN group (Z = −2.17 and -2.360, respectively, p < 0.05) and pathological scores (Z = −2.687 and −2.082, respectively, p < 0.05). 3) Compared with the control group, the TP, BS and TP-SLN were all effective in treating synovial blood flow and bone erosion and there were no significant differences of ultrasonic and pathological scores among them (p > 0.05). The ultrasonic scores of synovial blood flow (Z = −3.033, −2.842, −3.277, p < 0.01) were lower than in the controls. The ultrasonic scores (Z = -2.948, -3.141, -3.210, p < 0.01) and pathological scores (Z = −2.216, −2.505, −2.505, p < 0.05) of bone erosion were also lower than in the model group.4) There were significant correlations between the ultrasonic and pathological scores of synovial inflammation and bone erosion (r = 0.832 and 0.859 respectively, p < 0.001).

Conclusions: The therapeutic effect of TP-SLN on arthritis is better than that of TP, but there is no difference between BS and TP-SLN. Therefore, TP-SLN may be used as an alternative to BS in the treatment of rheumatoid arthritis in the future. The ultrasonic and pathological scores showed significant correlation in synovitis and bone erosion. Ultrasound can provide a useful assessment of synovitis in early arthritis.

Targeting tryptophan metabolism reveals Clematichinenoside AR alleviates triptolide-induced hepatotoxicity

Liver toxicity induced by Triptolide (TP) has limited its clinical application on rheumatoid arthritis (RA). Saponins have been proved as an efficacious remedy to mitigate hepatotoxicity. However, the mechanism of reducing hepatotoxicity by saponins intervention remains incompletely characterized. Tryptophan (Trp) metabolites activate transcriptional regulators to mediate host detoxification responses. Our study aimed to investigate whether Clematichinenoside AR (C-AR) could attenuate TP-induced liver damage by regulating Trp metabolism. We used targeted metabolomics to quantify Trp metabolites in the serum and liver samples of collagen-induced arthritis rats treated by TP. Multiple comparison analyses helped the evaluation of promising biomarkers. The pronounced changed levels of Trp, indole acetic acid, and indole-3-carboxaldehyde in the serum and indole acetic acid, indole, and tryptamine in the liver are relevant to TP-induced liver injury. Intervention with C-AR could relieve TP-induced hepatotoxicity evidenced by ameliorative serum parameters and hepatic histology. In addition, C-AR regulated the levels of these indoles biomarker candidates to normal. Therapeutic modulation with natural compounds might be a useful clinical strategy to ameliorate toxicity induced by TP. Deciphering Trp metabolism will facilitate a better understanding of the pathogenesis of diseases and drug responding.

A molecular insight of inflammatory cascades in rheumatoid arthritis and anti-arthritic potential of phytoconstituents

Rheumatoid arthritis (RA) is an auto-immune inflammatory disorder of the synovial lining of joints marked by immune cells infiltration and hyperplasia of synovial fibroblasts which results in articular cartilage destruction and bone erosion. The current review will provide comprehensive information and results obtained from the recent research on the phytochemicals which were found to have potential anti-arthritic activity along with the molecular pathway that were targeted to control RA progression. In this review, we have summarized the scientific data from various animal studies about molecular mechanisms, possible side effects, associations with conventional therapies, and the role of complementary and alternative medicines (CAM) for RA such as ayurvedic medicines in arthritis. In the case of RA, phytochemicals have been shown to act through different pathways such as regulation of inflammatory signaling pathways, T cell differentiation, inhibition of angiogenic factors, induction of the apoptosis of fibroblast-like synoviocytes (FLS), inhibition of autophagic pathway by inhibiting High-mobility group box 1 protein (HMGB-1), Akt/ mTOR pathway and HIF-1α mediated Vascular endothelial growth (VEGF) expression. Also, osteoclasts differentiation is inhibited by down-regulating the VEGF expression by decreasing the accumulation of the ARNT (Aryl Hydrocarbon Receptor Nuclear Translocator)-HIF-1α complex Although phytochemicals have shown to exert potential anti-arthritic activity in many animal models and further clinical data is needed to confirm their safety, efficacy, and interactions in humans.

Tripterygium hypoglaucum (Lévl.) Hutch and Its Main Bioactive Components: Recent Advances in Pharmacological Activity, Pharmacokinetics and Potential Toxicity

Tripterygium hypoglaucum (Lévl.) Hutch (THH) is believed to play an important role in health care and disease treatment according to traditional Chinese medicine. Moreover, it is also the representative of medicine with both significant efficacy and potential toxicity. This characteristic causes THH hard for embracing and fearing. In order to verify its prospect for clinic, a wide variety of studies were carried out in the most recent years. However, there has not been any review about THH yet. Therefore, this review summarized its characteristic of components, pharmacological effect, pharmacokinetics and toxicity to comprehensively shed light on the potential clinical application. More than 120 secondary metabolites including terpenoids, alkaloids, glycosides, sugars, organic acids, oleanolic acid, polysaccharides and other components were found in THH based on phytochemical research. All these components might be the pharmacological bases for immunosuppression, anti-inflammatory and anti-tumour effect. In addition, recent studies found that THH and its bioactive compounds also demonstrated remarkable effect on obesity, insulin resistance, fertility and infection of virus. The main mechanism seemed to be closely related to regulation the balance of immune, inflammation, apoptosis and so on in various disease. Furthermore, the study of pharmacokinetics revealed quick elimination of the main component triptolide. The feature of celastrol was also investigated by several models. Finally, the side effect of THH was thought to be the key for its limitation in clinical application. A series of reports indicated that multiple organs or systems including liver, kidney and genital system were involved in the toxicity. Its potential serious problem in liver was paid specific attention in recent years. In summary, considering the significant effect and potential toxicity of THH as well as its components, the combined medication to inhibit the toxicity, maintain effect might be a promising method for clinical conversion. Modern advanced technology such as structure optimization might be another way to reach the efficacy and safety. Thus, THH is still a crucial plant which remains for further investigation.

The antioxidant effect of triptolide contributes to the therapy in a collagen-induced arthritis rat model

BACKGROUND

As a chronic autoimmune disease, rheumatoid arthritis (RA) is related to oxidative stress, which may lead to the occurrence and persistence of inflammation in RA. The purpose of this study is to evaluate the potential antioxidant effect of triptolide in collagen-induced arthritis (CIA) rat model.

METHODS

We examined the severity of arthritis, levels of local and systemic oxidative stress, periarticular bone erosion and weight of organs in CIA rats treated with triptolide.

RESULTS

We found that triptolide decreased the paw thickness and clinical arthritis score, significantly. The mRNA expression and activity of myeloperoxidase and inducible nitric oxide synthase were remarkably decreased in the paws of the CIA rats after triptolide treatment. Triptolide significantly inhibited the levels of nitrite and nitrate in serum, as well as the urinary level of dityrosine. Triptolide treatment also markedly increased bone volume of tibia, but suppressed epiphyseal plate thickness of both femur and tibia. In addition, there was no significant difference in the weight of organs after the therapy, except decreased spleen weight.

CONCLUSIONS

These results suggested that the local and systemic oxidative stress was enhanced in the CIA rats and the therapeutic dose of triptolide had a definite antioxidant effect.

Triptolide inhibits neutrophil extracellular trap formation

Background

Triptolide (PG490), as a triterpene dicyclic oxide has been reported to increase the generation of reactive oxygen species (ROS) and nitric oxide (NO) and induce apoptosis of RAW 264.7 cells in a dose-dependent manner. The activity of death NETs plays an important role in anti-bacterial processes in the human body. This study aimed to investigate the effect of triptolide (PG490) on neutrophil extracellular traps (NETs) formation.

Methods

After isolating peripheral blood neutrophils from healthy volunteers, cells were incubated with PG490 to observe and detect the level of NETs and detect the level of reactive oxygen species (ROS). The cells were cultured, stained and analyzed by fluorescence microscopy.

Results

Compared with the 12-myristate-13-acetate (PMA) group, the average fluorescence intensity of SYTOX Green in the PG490 + PMA group, as detected by a multifunctional microplate reader, was significantly decreased. Intracellular ROS were labeled by fluorescence, with fluorescence intensity then measured by multifunctional microplate reader and flow cytometry. The results showed that compared with the control group, the fluorescence intensity of the PMA group was significantly increased, while there was no significant difference between PMA group and PG490 + PMA group.

Conclusions

The production of NETs is inhibited by PG490 in vitro, which is not associated with the level of cellular ROS. This suggests that PG490in Tripterygium wilfordii Hook F can suppress related diseases.

Trem1 Induces Periodontal Inflammation via Regulating M1 Polarization

Periodontitis is a chronic inflammatory condition characterized by destruction of nonmineralized and mineralized connective tissues. This study evaluated the role of Trem1 (triggering receptors expressed on myeloid cells 1) in periodontitis by influencing polarization of M1 macrophages through the STAT3/HIF-1α signaling pathway. Trem1 was significantly upregulated in the gingival tissues of patients with periodontitis, as identified by high-throughput RNA sequencing, and positively correlated with levels of M1 macrophage-associated genes. The results of flow cytometry, Western blotting, and reverse transcription quantitative polymerase chain reaction showed that knockdown of Trem1 in RAW 264.7 cells decreased polarization of M1 macrophages and increased polarization of M2 macrophages, while overexpression of Trem1 exerted an opposite effect. Furthermore, a mouse model of Trem1 knockout periodontitis exhibited limited infiltration of macrophages and decreased expression levels of M1 macrophage-associated genes in periodontitis lesions and bone marrow-derived macrophages. Importantly, we found that Trem1 could regulate polarization of M1 macrophages through STAT3/HIF-1α signaling as evidenced by RNA sequencing. Moreover, inhibition of Trem1 and HIF-1α could suppress the expression level of proinflammatory cytokine (interleukin 1β) and upregulate the expression level of anti-inflammatory cytokine (interleukin 10) in periodontitis. Collectively, we identified that the Trem1/STAT3/HIF-1α axis could regulate polarization of M1 macrophages and is a potential candidate in the treatment of periodontitis.

Disease-Modifying Anti-rheumatic Drug Prescription Baihu-Guizhi Decoction Attenuates Rheumatoid Arthritis via Suppressing Toll-Like Receptor 4-mediated NLRP3 Inflammasome Activation

As a traditional Chinese medicine-originated disease-modifying anti-rheumatic drug prescription, Baihu-Guizhi decoction (BHGZD) is extensively used for the treatment of rheumatoid arthritis (RA) with a satisfying therapeutic efficacy. Mechanically, our previous data indicated that BHGZD may ameliorate RA partially by restoring the balance of the “inflammation-immune” system through regulating the TLR4-c-Fos-IL2-TNF-alpha axis. Toll-like receptor 4 (TLR4) has been revealed to be involved in the activation of the NLR family pyrin domain containing 3 (NLRP3) inflammasome complex. Thus, the aim of the current study was to determine the regulatory effects of BHGZD on the TLR4–mediated inflammasome activation during RA progression based on the modified adjuvant-induced arthritis model (AIA-M) and the lipopolysaccharide/adenosine triphosphate (LPS/ATP)–induced pyroptosis cellular models. As a result, oral administration of BHGZD exhibited prominent improvement in the disease severity of AIA-M rats, such as reducing the redness and swelling of joints, arthritis incidence, arthritic scores, and diameter of the limb and increasing pain thresholds. In line with the in vivo findings, BHGZD treatment effectively inhibited the LPS/ATP–induced pyroptosis of both Raw264.7 macrophage and MH7A cells in vitro by reducing pyroptotic cell death morphology (swollen cells) and decreasing propidium iodide–positive and terminal deoxynucleotidyl transferase–mediated dUTP-fluorescein nick end labeling (TUNEL)–positive cells. Notably, the increased expression levels of TLR4, NLRP3, interleukin 1β, and interleukin 18 proteins and the elevated activities of caspase-1 and lactic dehydrogenase in in vivo and in vitro disease models were markedly reversed by the treatment with BHGZD. In conclusion, the above findings proved the immunomodulatory and anti-inflammatory activities of BHGZD, especially in pyroptosis, which may be attributed to the activation of TLR4–mediated NLRP3 inflammasome signaling.

Network Pharmacology-Based Analysis on the Curative Effect of Kunxian Capsules against Rheumatoid Arthritis

Kunxian capsules (KCs), a Chinese patent medicine, have been clinically proven to be effective in the treatment of rheumatoid arthritis (RA). However, the chemical profile of KC remains to be characterized, and the mechanism underlying the protective effect against RA is yet to be elucidated. Here, a network pharmacology-based approach was adopted, integrated with the chemical profiling of KC by UHPLC-Q-TOF/MS. As a result, a total of 67 compounds have been identified from KC extract, among which 43 were authenticated by comparison to the mass spectrum of standard chemicals. ADME behaviors of the chemical constituents of KC were predicted, resulting in 35 putative active ingredients. Through target prediction of both active ingredients of KC and RA and PPI analysis, core targets were screened out, followed by biological process and related pathway enrichment. Then, a TCM-herb-ingredient-target-pathway network was constructed and a multicomponent, multitarget, and multipathway synergistic mechanism was proposed, providing an information basis for further investigation. The active pharmaceutical ingredients included mainly terpenoids (such as triptolide and celastrol), sesquiterpene pyridines (such as wilforgine and wilforine), and flavonoids (such as icariin, epimedin A, B, and C, and 2″-O-rhamnosylicariside II).

Emergence of Dengue 4 as Dominant Serotype During 2017 Outbreak in South India and Associated Cytokine Expression Profile

Dengue virus (DENV) infection is prevalent in tropical and subtropical regions of the world, which is fatal if untreated symptomatically. Emergence of new genotype within serotypes led to enhanced severity. The objective of the study is to identify the molecular characteristics of the DENV circulated during 2017 outbreak in Tamil Nadu, India, and to investigate the role of inflammatory cytokines in different “serotypes” and in “dengue severity”. A total of 135 suspected samples were tested for DENV infection using IgM, IgG, and qPCR assay; where 76 samples were positive for DENV and analyzed for 12 inflammatory cytokines using ELISA. Serotyping shows 14 DENV-1, 22 DENV-2, 7 DENV-3, and 33 DENV-4, where DENV-4 was predominant. Among 76, 42 isolates were successfully sequenced for C-prM region and grouped. A lineage shift was observed in DENV-4 genotype. Irrespective of serotypes, IFNγ was significantly elevated in all serotypes than control as well as in primary infection than secondary, indicating its role in immune response. GM-CSF and IP-10 were significantly elevated in secondary infection and could be used as prognostic biomarkers for secondary infection. Our observation shows differential cytokine expression profile varied with each serotype, indicating serotype/genotype-specific viral proteins might play a major role in dengue severity. DENV-4 as dominant serotype was reported in Tamil Nadu for the first time during an outbreak with a mixed Th1/Th17 cytokine expression profile that correlated with disease severity. We conclude it is essential to identify circulating viral genotype and their fitness by mutational analysis to correlate with disease severity and immune status, as this correlation will be helpful in diagnostics and therapeutics applications.

Triptolide decreases rheumatoid arthritis fibroblast-like synoviocyte proliferation, invasion, inflammation and presents a therapeutic effect in collagen-induced arthritis rats via inactivating lncRNA RP11-83J16.1 mediated URI1 and β-catenin signaling

OBJECTIVE

Our previous study observed that long non-coding RNA (lncRNA) RP11-83J16.1 promoted rheumatoid arthritis (RA)-fibroblast-like synoviocyte (RA-FLS) proliferation, invasion and inflammation, which was downregulated by triptolide treatment. Therefore, the present study aimed to further investigate the mechanism and interaction between triptolide and lncRNA RP11-83J16.1 in RA treatment in vitro and in vivo.

METHODS

RA-FLS was isolated and treated by different concentration of triptolide and lncRNA RP11-83J16.1 overexpression plasmid. Furthermore, collagen-induced arthritis (CIA) rat model was constructed followed by triptolide and lncRNA RP11-83J16.1 overexpression plasmid treatment.

RESULTS

Triptolide inhibited RA-FLS viability and lncRNA RP11-83J16.1 expression in a dose-dependent manner. Afterward, triptolide treatment inhibited RA-FLS proliferation, invasion, levels of inflammatory markers (TNF-α, IL-1β, IL-6, MMP-3, and MMP-9), inactivated lncRNA RP11-83J16.1, URI1 and β-catenin signaling, but promoted apoptosis. However, lncRNA RP11-83J16.1 overexpression weakened the effects of triptolide on regulating RA-FLS cell behaviors, URI1 signaling and β-catenin signaling. In CIA model, triptolide decreased arthritis score, hyperproliferation of synovial cells, inflammation infiltration of synovial tissue, inflammatory markers (TNF-α, IL-1β, IL-6, MMP-3, and MMP-9), inactivated lncRNA RP11-83J16.1, URI1 and β-catenin signaling, but increased cell apoptosis rate of synovial tissue. Nevertheless, lncRNA RP11-83J16.1 curtailed the treatment effect of triptolide in CIA model.

CONCLUSION

Triptolide decreases RA-FLS proliferation, invasion, inflammation and presents a therapeutic effect in CIA model via inactivating lncRNA RP11-83J16.1 mediated URI1 and β-catenin signaling.

Phytochemical inhibitors of the NLRP3 inflammasome for the treatment of inflammatory diseases

The NLRP3 inflammasome holds a crucial role in innate immune responses. Pathogen- and danger-associated molecular patterns may initiate inflammasome activation and following inflammatory cytokine release. The inflammasome formation and its-associated activity are involved in various pathological conditions such as cardiovascular, central nervous system, metabolic, renal, inflammatory and autoimmune diseases. Although the mechanism behind NLRP3-mediated disorders have not been entirely illuminated, many phytochemicals and medicinal plants have been described to prevent inflammatory disorders. In the present review, we mainly introduced phytochemicals inhibiting NLRP3 inflammasome in addition to NLRP3-mediated diseases. For this purpose, we performed a systematic literature search by screening PubMed, Scopus, and Google Scholar databases. By compiling the data of phytochemical inhibitors targeting NLRP3 inflammasome activation, a complex balance between inflammasome activation or inhibition with NLRP3 as central player was pointed out in NLRP3-driven pathological conditions. Phytochemicals represent potential therapeutic leads, enabling the generation of chemical derivatives with improved pharmacological features to treat NLRP3-mediated inflammatory diseases.

Triptolide: pharmacological spectrum, biosynthesis, chemical synthesis and derivatives

Triptolide, an abietane-type diterpenoid isolated from Tripterygium wilfordii Hook. F., has significant pharmacological activity. Research results show that triptolide has obvious inhibitory effects on many solid tumors. Therefore, triptolide has become one of the lead compounds candidates for being the next "blockbuster" drug, and multiple triptolide derivatives have entered clinical research. An increasing number of researchers have developed triptolide synthesis methods to meet the clinical need. To provide new ideas for researchers in different disciplines and connect different disciplines with researchers aiming to solve scientific problems more efficiently, this article reviews the research progress made with analyzes of triptolide pharmacological activity, biosynthetic pathways, and chemical synthesis pathways and reported in toxicological and clinical studies of derivatives over the past 20 years, which have laid the foundation for subsequent researchers to study triptolide in many ways.

Triptolide prevents LPS-induced skeletal muscle atrophy via inhibiting NF-κB/TNF-α and regulating protein synthesis/degradation pathway

BACKGROUND AND PURPOSE

Increasing evidence suggests systemic inflammation-caused skeletal muscle atrophy as a major clinical feature of cachexia. Triptolide obtained from Tripterygium wilfordii Hook F possesses potent anti-inflammatory and immunosuppressive effects. The present study aims to evaluate the protective effects and molecular mechanisms of triptolide on inflammation-induced skeletal muscle atrophy.

EXPERIMENTAL APPROACH

The effects of triptolide on skeletal muscle atrophy were investigated in LPS-treated C2C12 myotubes and C57BL/6 mice. Protein expressions and mRNA levels were analysed by western blot and qPCR, respectively. Skeletal muscle mass, volume and strength were measured by histological analysis, micro-CT and grip strength, respectively. Locomotor activity was measured using the open field test.

KEY RESULTS

Triptolide (10-100 fM) up-regulated protein synthesis signals (IGF-1/p-IGF-1R/IRS-1/p-Akt/p-mTOR) and down-regulated protein degradation signal atrogin-1 in C2C12 myotubes. In LPS (100 ng·ml^-1 )-treated C2C12 myotubes, triptolide up-regulated MyHC, IGF-1, p-IGF-1R, IRS-1 and p-Akt. Triptolide also down-regulated ubiquitin-proteasome molecules (n-FoxO3a/atrogin-1/MuRF1), proteasome activity, autophagy-lysosomal molecules (LC3-II/LC3-I and Bnip3) and inflammatory mediators (NF-κB, Cox-2, NLRP3, IL-1β and TNF-α). However, AG1024, an IGF-1R inhibitor, suppressed triptolide-mediated effects on MyHC, myotube diameter, MuRF1 and p62 in LPS-treated C2C12 myotubes. In LPS (1 mg·kg^-1 , i.p.)-challenged mice, triptolide (5 and 20 μg·kg^-1 ·day^-1 , i.p.) decreased plasma TNF-α levels and it increased skeletal muscle volume, cross-sectional area of myofibers, weights of the gastrocnemius and tibialis anterior muscles, forelimb grip strength and locomotion.

CONCLUSIONS AND IMPLICATIONS

These findings reveal that triptolide prevented LPS-induced inflammation and skeletal muscle atrophy and have implications for the discovery of novel agents for preventing muscle wasting.

Cigarette smoke extract-treated airway epithelial cells-derived exosomes promote M1 macrophage polarization in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a persistent respiratory disorder that is primarily caused by exposure to cigarette smoke (CS). Exosomes have emerged as crucial mediators of intercellular communication, but their role in CS-induced COPD is not fully understood. Here, we investigated whether exosomes derived from cigarette smoke extract (CSE)-treated mouse airway epithelial cells (MAECs) promote M1 macrophage polarization by upregulating triggering receptor expressed on myeloid cells-1 (TREM-1) expression during COPD pathogenesis. The exosomes isolated from PBS- or CSE-treated MAECs were named as Exo^PBS or Exo^CSE, respectively. Macrophages were transfected with si-TREM-1 to explore the role of TREM-1 in Exo^CSE-induced M1 macrophage polarization. The lentivirus expressing shTREM-1 was injected into COPD model mice by intranasal instillation, which was carried out to explore the in vivo role of TREM-1 in Exo^CSE-induced M1 macrophage polarization and CS-induced lung injury. We isolated Exo^PBS and Exo^CSE successfully, and found that Exo^CSE promoted M1 macrophage polarization. Furthermore, we found that the promotion of Exo^CSE to M1 macrophage polarization was partly reversed by TREM-1 knockdown. The results of animal experiments showed that Exo^CSE administration aggravated CS-induced impairment in pulmonary function, lung injury and M1 macrophage polarization, which were partly rescued by TREM-1 silencing. Overall, Exo^CSE promoted M1 macrophage polarization by upregulating TREM-1 expression, thereby aggravating the development of COPD.

Exploring a novel triptolide derivative possess anti-colitis effect via regulating T cell differentiation

Inflammatory bowel disease (IBD) is generally characterized by chronic inflammatory disorders of the gastrointestinal tract that are known as ulcerative colitis (UC) or Crohn's disease (CD). Although the underlying mechanism of action of IBD is unclear and because of the lack of satisfactory treatment, increasing evidence has indicated that pro-inflammatory cytokines that activate JAK-STAT signaling pathway regulate the differentiation of naïve T cells towards T helper (Th)1 and Th17 cell subsets and contribute to the development of IBD. ZT01 is a newly obtained triptolide derivative with strong anti-inflammatory effects and low toxicity. In this study, we evaluated the effects of ZT01 on DSS-induced colitis and investigated the underlying mechanism of action involved. Mice with DSS-induced acute or chronic colitis were used to assess the efficacy of ZT01 treatment, and T cells were cultured to analyze the differentiation of Th1 and Th17 cell by flow cytometry. In addition, intestinal epithelial barrier function, macrophage polarization, activation of the JAK-STAT signaling pathway, and the expression of cytokines and transcription factors were measured to assess the possible mechanisms of ZT01. We found that ZT01 had an obviously beneficial effect on DSS-induced colitis by improving the symptoms of bloody diarrhea, weight loss, and a shortened colon, thereby preserving the epithelial barrier function in the mouse colon. Furthermore, ZT01 significantly inhibited T cell differentiation into Th1 and/or Th17 cell subsets and macrophage polarization towards into an inflammatory phenotype via regulating the JAK-STAT signaling pathway. Thus, our findings suggested that ZT01 might be a potential pharmaceutical candidate that deserves to be further investigated as a treatment for IBD patients.

Identification of Dendritic Cell Maturation, TLR, and TREM1 Signaling Pathways in the Brucella canis Infected Canine Macrophage Cells, DH82, Through Transcriptomic Analysis

Research has been undertaken to understand the host immune response to Brucella canis infection because of the importance of the disease in the public health field and the clinical field. However, the previous mechanisms governing this infection have not been elucidated. Therefore, in vitro models, which mimic the in vivo infection route using a canine epithelial cell line, D17, and a canine macrophage, DH82, were established to determine these mechanisms by performing an analysis of the transcriptomes in the cells. In this study, a coculture model was constructed by using the D17 cell line and DH82 cell line in a transwell plate. Also, a single cell line culture system using DH82 was performed. After the stimulation of the cells in the two different systems infected with B. canis, the gene expression in the macrophages of the two different systems was analyzed by using RNA-sequencing (RNA-seq), and a transcriptomic analysis was performed by using the Ingenuity Pathway Analysis (IPA). Gene expression patterns were analyzed in the DH82 cell line at 2, 12, and 24 h after the stimulation with B. canis. Changes in the upregulated or downregulated genes showing 2-fold or higher were identified at each time point by comparing with the non-stimulated group. Differentially expressed genes (DEGs) between the two culture models were identified by using the IPA program. Generally, the number of genes expressed in the single cell line culture was higher than the number of genes expressed in the coculture model for all-time points. The expression levels of those genes were higher in the single cell line culture (p < 0.05). This analysis indicated that the immune response-related pathways, especially, the dendritic cell maturation, Triggering receptor expression on myeloid cells 1 (TREM1) signaling, and Toll-like receptor (TLR) signaling pathway, were significantly induced in both the culture systems with higher p-values and z-scores. An increase in the expression level of genes related to the pathways was observed over time. All pathways are commonly associated with a manifestation of pro-inflammatory cytokines and early immune responses. However, the Peroxisome proliferator-activation receptor (PPAR) signaling and Liver X Receptor/Retinoid X Receptor (LXR/RXR) signaling associated with lipid metabolism were reduced. These results indicate that early immune responses might be highly activated in B. canis infection. Therefore, these results might suggest clues to reveal the early immune response of the canine to B. canis infection, particularly TLR signaling.

The Role of Chronic Inflammation in Various Diseases and Anti-inflammatory Therapies Containing Natural Products

Chronic inflammation represents a long-term reaction of the body's immune system to noxious stimuli. Such a sustained inflammatory response sometimes results in lasting damage to healthy tissues and organs. In fact, chronic inflammation is implicated in the development and progression of various diseases, including cardiovascular diseases, respiratory diseases, metabolic diseases, neurodegenerative diseases, and even cancers. Targeting nonresolving inflammation thus provides new opportunities for treating relevant diseases. In this review, we will go over several chronic inflammation-associated diseases first with emphasis on the role of inflammation in their pathogenesis. Then, we will summarize a number of natural products that exhibit therapeutic effects against those diseases by acting on different markers in the inflammatory response. We envision that natural products will remain a rich resource for the discovery of new drugs treating diseases associated with chronic inflammation.

BRD4 inhibition alleviates mechanical stress-induced TMJ OA-like pathological changes and attenuates TREM1-mediated inflammatory response

The aim of this paper was to investigate the protective effects of bromodomain containing 4 (BRD4) inhibition on the temporomandibular joint osteoarthritis (TMJ OA) induced by compressive mechanical stress and to explore the underlying mechanism. In vivo, a rat model of TMJ compressive loading device was used and BRD4 inhibitor was injected into the TMJ region. HE staining and micro-CT analysis were used for histological and radiographic assessment. Immunohistochemistry and qPCR were performed to detect inflammatory cytokines expressions. High-throughput ChIP-sequencing screening was performed to compare the BRD4 and H3K27ac binding patterns between condylar cartilage from control and mechanical force groups. In vitro, the mandibular condylar chondrocytes were treated with IL-1β. Small Interference RNA (siRNA) infection was used to silencing BRD4 or TREM1. qPCR was performed to detect inflammatory cytokines expressions. Our study showed that BRD4 inhibition can alleviate the thinning of condylar cartilage and subchondral bone resorption, as well as decrease the inflammatory factors expression both in vivo and in vitro. ChIP-seq analysis showed that BRD4 was more enriched in the promoter region of genes related to the stress and inflammatory pathways under mechanical stress in vivo. Trem1, a pro-inflammatory gene, was screened out from the overlapped BRD4 and H3K27ac increased binding sites, and Trem1 mRNA was found to be regulated by BRD4 inhibition both in vivo and in vitro. TREM1 inhibition reduced the expression of inflammatory factors induced by IL-1β in vitro. In summary, we concluded that BRD4 inhibition can protect TMJ OA-like pathological changes induced by mechanical stress and attenuate TREM1-mediated inflammatory response.

Phytochemicals as Anti-Inflammatory Agents in Animal Models of Prevalent Inflammatory Diseases

Phytochemicals are known to have anti-inflammatory effects in vitro and in vivo, such as in inflammatory disease model systems. Inflammation is an essential immune response to exogenous stimuli such as infection and injury. Although inflammation is a necessary host-defense mechanism, chronic inflammation is associated with the continuous local or systemic release of inflammatory mediators, non-cytokine mediators, such as ROS and NO, and inflammatory cytokines are strongly implicated in the pathogenesis of various inflammatory disorders. Phytochemicals that exhibit anti-inflammatory mechanisms that reduce sustained inflammation could be therapeutic candidates for various inflammatory diseases. These phytochemicals act by modulating several main inflammatory signaling pathways, including NF-κB, MAPKs, STAT, and Nrf-2 signaling. Here, we discuss the characteristics of phytochemicals that possess anti-inflammatory activities in various chronic inflammatory diseases and review the molecular signaling pathways altered by these anti-inflammatory phytochemicals, with a focus on transcription factor pathways. Furthermore, to evaluate the phytochemicals as drug candidates, we translate the effective doses of phytochemicals in mice or rat disease models into the human-relevant equivalent and compare the human-relevant equivalent doses of several phytochemicals with current anti-inflammatory drugs doses used in different types of chronic inflammatory diseases.

Mechanism of TREM2/DAP12 complex affecting β-amyloid plaque deposition in Alzheimer's disease modeled mice through mediating inflammatory response

To investigate the mechanism of TREM2/DAP12 complex in mediating inflammatory responses that affect β-amyloid plaque deposition in Alzheimer's disease (AD) modeled mice. We measured escape latency and platform crossing time using the Morris water maze image automatic acquisition and software analysis system in TREM2 and DAP12 microglia knockout AD model mouse. We monitored the deposition of Aβ plaques in the mouse hippocampus using Congo red staining and measured levels. of inflammatory factors IL-6 and TNF-α by ELISA. Newborn mice with TREM2 knockout were selected for primary microglia isolation and culture, and Aged oligomer Aβ1-42 was added to the microglial culture medium to simulate the AD environment in vivo. Co-immunoprecipitation assay was used to detect the interaction between DAP12 and TREM2, and measured the inflammatory response induced by lipopolysaccharide (LPS) in mice with TREM2 and DAP12 knockdown through adeno-associated virus in BV2 microglia. The escape latency of the AD model mice with TREM2 and DAP12 knockout was higher and the number of crossing platforms lower than in the control group, whereas Aβ deposition and levels of inflammatory factors were higher. In TREM2 knockout microglial cultured with Aβ1-42, levels of IL-6 and TNF-α increased. Immunoprecipation pull-down assays showed that TREM2 binds to the membrane receptor DAP12 to form a complex. Knockout of TREM2 or DAP12 can inhibit LPS-induced microglial inflammatory responses. The TREM2/DAP12 complex inhibits the microglial inflammatory response through the JNK signaling pathway, thereby reducing the deposition of Aβ plaques and attenuation the behavioral manifestation in a mouse AD model.

Effect of Triptolide on Temporal Expression of Cell Cycle Regulators During Cardiac Hypertrophy

Adult mammalian cardiomyocytes may reenter the cell cycle and cause cardiac hypertrophy. Triptolide (TP) can regulate the expressions of various cell cycle regulators in cancer cells. However, its effects on cell cycle regulators during myocardial hypertrophy and mechanism are unclear. This study was designed to explore the profile of cell cycle of cardiomyocytes and the temporal expression of their regulators during cardiac hypertrophy, as well as the effects of TP. The hypertrophy models employed were neonatal rat ventricular myocytes (NRVMs) stimulated with angiotensin II (Ang II) for scheduled times (from 5 min to 48 h) in vitro and mice treated with isoprenaline (Iso) for from 1 to 21 days, respectively. TP was used in vitro at 1 μg/L and in vivo at 10 μg/kg. NRVMs were analyzed using flow cytometry to detect the cell cycle, and the expression levels of mRNA and protein of various cell cycle regulators were determined using real-time PCR and Western blot. It was found NRVM numbers in phases S and G₂ increased, while that in the G₁ phase decreased significantly after Ang II stimulation. The mRNA expression levels of p21 and p27 increased soon after stimulation, and thereafter, mRNA expression levels of all cell cycle factors showed a decreasing trend and reached their lowest levels in 1–3 h, except for cyclin-dependent kinase 1 (CDK1) and CDK4 mRNA. The mRNA expression levels of CDK1, p21, and p27 increased markedly after stimulation with Ang II for 24–48 h. In myocardium tissue, CDK and cyclin expression levels peaked in 3–7 days, followed by a decreasing trend, while those of p21 and p27 mRNA remained at a high level on day 21. Expression levels of all protein were consistent with the results of mRNA in NRVMs or mice. The influence of Ang II or Iso on protein expression was more obvious than that on mRNA. TP treatment effectively prevented the imbalance in the expression of cell cycle regulators in the hypertrophy model group. In Conclusion, an imbalance in the expression of cell cycle regulators occurs during cardiac hypertrophy, and triptolide corrects these abnormal expression levels and attenuates cardiac hypertrophy.

Therapeutic targets of thunder god vine (Tripterygium wilfordii hook) in rheumatoid arthritis (Review)

Celastrol and triptolide, chemical compounds isolated from Tripterygium wilfordii hook (also known as thunder god vine), are effective against rheumatoid arthritis (RA). Celastrol targets numerous signaling pathways involving NF‑κB, endoplasmic reticulum Ca2+‑ATPase, myeloid differentiation factor 2, toll‑like receptor 4, pro‑inflammatory chemokines, DNA damage, cell cycle arrest and apoptosis. Triptolide, inhibits NF‑κB, the receptor activator of NF‑κB (RANK)/RANK ligand/osteoprotegerin signaling pathway, cyclooxygenase‑2, matrix metalloproteases and cytokines. The present review examined the chemistry and bioavailability of celastrol and triptolide, and their molecular targets in treating RA. Clinical studies have demonstrated that T. wilfordii has several promising bioactivities, but its multi‑target toxicity has restricted its application. Thus, dosage control and structural modification of T. wilfordii are required to reduce the toxicity. In this review, future directions for research into these promising natural products are discussed.

Efficient Delivery of Triptolide Plus a miR-30-5p Inhibitor Through the Use of Near Infrared Laser Responsive or CADY Modified MSNs for Efficacy in Rheumatoid Arthritis Therapeutics

Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory disease for which treatment focuses on suppressing an overactive immune system and maintaining the physiological balance of synovial fibroblasts (SFs). We found that miR-30-5p was highly expressed in rheumatoid arthritis synovial fibroblasts (RASFs). Subsequently, we predicted that phosphatidylinositol 3-kinase regulatory subunit 2 (PIK3R2) might be a putative target of miR-30-5p. Recent studies have reported that PIK3R2 can maintain the physiological homeostasis of RASFs. Therefore, miR-30-5p inhibitor has the potential to be used in the treatment of RA, but low levels of miR-30-5p inhibitor internalization affect its application. Triptolide (TP) is an effective drug in the treatment of RA but induces severe toxicity and has a narrow therapeutic window. In this study, the cell internalization performance of miR-30-5p inhibitor was improved by loading it into cell membrane penetrating peptide (CADY)-modified mesoporous silica nanoparticles (MSNs), and the toxicity of TP was decreased by loading it into a controlled drug release system based on MSNs. The nanodrug carrier was constructed by filling a phase-change material (PCM) of 1-tetradecanol and drugs into MSNs that could be triggered by an NIR laser with thermo-chemo combination RA therapy. Our results show that the miR-30-5p inhibitor-loaded MSNs@CADY significantly inhibited RASF proliferation and increased apoptosis. In addition, MSNs@PCM@TP under 808 nm laser irradiation were effective in downregulating immune system activation in an RA rat model. Finally, the results of a pharmacodynamics study showed that the combination of MSNs@CADY@miR-30-5p inhibitor and MSNs@PCM@TP under 808 nm laser significantly increased the effectiveness of RA treatment. These findings provide a novel understanding of RA pathogenesis and a theoretical basis for RA treatment.

Prediction of triptolide targets in rheumatoid arthritis using network pharmacology and molecular docking

Network pharmacology is a novel approach that uses bioinformatics to predict and identify multiple drug targets and interactions in disease. Here, we used network pharmacology to investigate the mechanism by which triptolide acts in rheumatoid arthritis (RA). We first searched public databases for genes and proteins known to be associated with RA, as well as those predicted to be targets of triptolide, and then used Ingenuity Pathway Analysis (IPA) to identify enriched gene pathways and networks. Networks and pathways that overlapped between RA-associated proteins and triptolide target proteins were then used to predict candidate protein targets of triptolide in RA. The following proteins were found to occur in both RA-associated networks and triptolide target networks: CD274, RELA, MCL1, MAPK8, CXCL8, STAT1, STAT3, c-JUN, JNK, c-Fos, NF-κB, and TNF-α. Docking studies suggested that triptolide can fit in the binding pocket of the six top candidate triptolide target proteins (CD274, RELA, MCL1, MAPK8, CXCL8 and STAT1). The overlapping pathways were activation of Th1 and Th2 cells, macrophages, fibroblasts and endothelial cells in RA, while the overlapping networks were involved in cellular movement, hematological system development and function, immune cell trafficking, cell-to-cell signaling and interaction, inflammatory response, cellular function and maintenance, and cell death and survival. These results show that network pharmacology can be used to generate hypotheses about how triptolide exerts therapeutic effects in RA. Network pharmacology may be a useful method for characterizing multi-target drugs in complex diseases.

Deciphering the Active Ingredients and Molecular Mechanisms of Tripterygium hypoglaucum (Levl.) Hutch against Rheumatoid Arthritis Based on Network Pharmacology

Tripterygium hypoglaucum (Levl.) Hutch (THH) shows well clinical effect on rheumatoid arthritis (RA), but the active ingredients and molecular mechanisms remain unclear. This work was designed to explore these issues by network pharmacology. Compounds from THH were gathered by retrieving literatures. Compound-related and RA-related genes were identified using databases, and the overlapping genes were identified by Venn diagram. The active ingredients and genes of THH against RA were confirmed by dissecting interactions between overlapping genes and compounds using Cytoscape. SystemsDock website was used to further verify the combining degree of key genes with active ingredients. Pathway enrichment analysis was performed to decipher the mechanisms of THH against RA by Database for Annotation, Visualization and Integrated Discovery. A total of 123 compounds were collected, and 110 compounds-related and 1871 RA-related genes were identified, including 64 overlapping genes. The target genes and active ingredients of THH against RA comprised 64 genes and 17 compounds, the focus of which was PTGS2, triptolide, and celastrol. SystemsDock website indicated that the combing degree of PTGS2 with triptolide or celastrol was very good. The mechanisms of THH against RA were linked to 31 signaling pathways, and the key mechanism was related to inhibition of inflammation response through inactivating TNF and NF-kappa B signaling pathways. This work firstly explored the active ingredients and mechanisms of THH against RA by network pharmacology and provided evidence to support clinical effects of THH on RA.

Inhibition of Triggering Receptor Expressed on Myeloid Cell-1 Alleviates Acute Gouty Inflammation

Gout is a prevalent form of aseptic inflammation caused by the deposition of monosodium urate (MSU) crystals in joints or tissues. Triggering receptor expressed on myeloid cell-1 (TREM-1) is a superimmunoglobulin receptor expressed on innate immune cells including granulocytes, monocytes, and macrophages. TREM-1 serves as a link between innate immunity and adaptive immunity, playing a crucial role in regulating inflammation and immune response. The purpose of this study was to investigate the potential role of TREM-1 in THP-1 cells and peripheral blood mononuclear cells (PBMCs) from patients with gouty arthritis (GA). In the current study, we found that the mRNA and protein levels of TREM-1 increased in PBMCs from GA patients and soluble TREM-1 in plasma as well. In addition, an increased level of TREM-1 was observed in THP-1 treated with monosodium urate (MSU) in vitro, along with upregulation of proinflammatory cytokines. Moreover, upon specific inhibition of TREM-1, Toll-like receptor 4 (TLR-4), and myeloid differentiation factor 88 (MyD88), the levels of MyD88 and proinflammatory cytokines were decreased after MSU challenge in THP-1 cells. Interestingly, inhibition of TLR-4 could enhance the effect of TREM-1 inhibitor in MSU-induced inflammation. Taken together, our findings suggested that TREM-1 could accelerate MSU-induced acute inflammation. Inhibition of TREM-1 may provide a new strategy for alleviating acute gouty inflammation.

Cubic and hexagonal liquid crystals as drug carriers for the transdermal delivery of triptolide

The purpose of this study was to develop and evaluate triptolide-loaded cubic and hexagonal liquid crystals for transdermal drug delivery systems (TDDSs). We prepared and characterized triptolide-loaded lyotropic liquid crystals and evaluated for their percutaneous permeation properties in vitro and in vivo. We then used the adjuvant arthritic rat model and HaCaT cells to analyze the pharmacodynamics and conduct cell-stimulating studies of these liquid crystals. The optimized preparations were identified as cubic and hexagonal phase structures, respectively. Moreover, the in vitro percutaneous penetration studies demonstrated that compared to the homemade triptolide gel, cubic and hexagonal liquid crystals could significantly increase the percutaneous cumulative penetration of drugs within 48 h. Besides, the results of skin-blood synchronous microdialysis showed that the triptolide concentration in skin was higher than that in blood, and the cubic and hexagonal liquid crystals significantly increased the bioavailability of triptolide. Triptolide-loaded cubic and hexagonal liquid crystals presented excellent anti-arthritic effects, alleviating paw swelling and inhibiting inflammation by downregulating the levels of TNF-α and IL-1β. In vitro cell-stimulating studies displayed that triptolide-loaded cubic and hexagonal liquid crystals exhibited no obvious toxicity, which exhibited that triptolide-loaded cubic and hexagonal liquid crystals were remarkable biocompatibility. Collectively, triptolide-loaded cubic and hexagonal liquid crystals represented a promising candidate for rheumatoid arthritis therapy.