Anti-inflammatory and immune-regulatory cytokines in rheumatoid arthritis

Revealing the Active Constituents and Mechanisms of Semiliquidambar cathayensis Chang Roots against Rheumatoid Arthritis through Network Pharmacology, Molecular Docking, and in Vivo Experiment

Semiliquidambar cathayensis Chang roots (SC) are traditional Chinese medicine for treating rheumatoid arthritis (RA). However, the effect and potential mechanism of SC remain unclear. This study aims to reveal the anti-RA constituents and mechanisms of SC based on network pharmacology, molecular docking, and adjuvant-induced arthritis (AIA) model rat experiment. In this work, 9 potential active constituents, including kaempferol, quercetin, naringenin, paeoniflorin, catechin, fraxin, gentianin, hesperetin, and ellagic acid 3,3',4-trimethyl ether, in SC crossed 65 target genes of RA. In addition, 28 core targets were enriched in inflammation and others, among which interleukin-17 (IL-17) and tumor necrosis factor (TNF) were the major targets. The binding of bio-constituents with IL-17 and TNF were performed using molecular docking. Rat experiment demonstrated that the extract of SC restored body weight loss, reduced arthritis score and the indices of thymus and spleen, alleviated ankle joint histopathology, decreased the levels of rheumatoid factor (RF), C-reactive protein (CRP), IL-17, TNF-α, IL-1β, IL-6, cyclooxygenase-2 (COX-2), 5-lipoxygenase (5-LOX), and matrix metalloproteinase-2 (MMP-2), whereas elevated the levels of IL-4 and IL-10. Collectively, it was the first time to comprehensively reveal the anti-RA efficacy and mechanism of SC via suppressing the inflammatory pathway based on network pharmacology, molecular docking, and experimental verification, which provide chemical and pharmacological evidences for the clinical application of SC.

The immunosuppressive effects and mechanisms of loureirin B on collagen-induced arthritis in rats

Introduction

Rheumatoid arthritis (RA) is a common disease mainly affecting joints of the hands and wrists. The discovery of autoantibodies in the serum of patients revealed that RA belonged to the autoimmune diseases and laid a theoretical basis for its immunosuppressive therapy. The pathogenesis of autoimmune diseases mainly involves abnormal activation and proliferation of effector memory T cells, which is closely related to the elevated expression of Kv1.3, a voltage-gated potassium (Kv) channel on the effector memory T cell membrane. Drugs blocking the Kv1.3 channel showed a strong protective effect in RA model animals, suggesting that Kv1.3 is a target for the discovery of specific RA immunosuppressive drugs.

Methods

In the present study, we synthesized LrB and studied the effects of LrB on collagen- induced arthritis (CIA) in rats. The clinical score, paw volume and joint morphology of CIA model rats were compared. The percentage of CD3+, CD4+ and CD8+ T cells in rat peripheral blood mononuclear and spleen were analyzed with flow cytometry. The concentrations of inflammatory cytokines interleukin (IL)-1b, IL-2, IL-4, IL-6, IL-10 and IL-17 in the serum of CIA rats were analyzed with enzyme-linked immunosorbent assay. The IL-1b and IL-6 expression in joints and the Kv1.3 expression in peripheral blood mononuclear cells (PBMCs) were quantified by qPCR. To further study the mechanisms of immunosuppressive effects of LrB, western blot and immunofluorescence were utilized to study the expression of Kv1.3 and Nuclear Factor of Activated T Cells 1 (NFAT1) in two cell models - Jurkat T cell line and extracted PBMCs.

Results

LrB effectively reduced the clinical score and relieved joint swelling. LrB could also decrease the percentage of CD4+ T cells, while increase the percentage of CD8+ T cells in peripheral blood mononuclear and spleen of rats with CIA. The concentrations of inflammatory cytokines interleukin (IL)-1b, IL-2, IL-6, IL-10 and IL-17 in the serum of CIA rats were significantly reduced by LrB. The results of qPCR showed that Kv1.3 mRNA in the PBMCs of CIA rats was significantly higher than that of the control and significantly decreased in the LrB treatment groups. In addition, we confirmed in cell models that LrB significantly decreased Kv1.3 protein on the cell membrane and inhibited the activation of Nuclear Factor of Activated T Cells 1 (NFAT1) with immune stimulus.

Conclusion

In summary, this study revealed that LrB could block NFAT1 activation and reduce Kv1.3 expression in activated T cells, thus inhibiting the proliferation of lymphocytes and the release of inflammatory cytokines, thereby effectively weakening the autoimmune responses in CIA rats. The effects of immunosuppression due to LrB revealed its potential medicinal value in the treatment of RA.

Simultaneous quantitative analysis and in vitro anti-arthritic effects of five polyphenols from Terminalia chebula

Background: The fruit of Terminalia chebula has been widely used for a thousand years for treating diarrhea, ulcers, and arthritic diseases in Asian countries. However, the active components of this Traditional Chinese medicine and their mechanisms remain unclear, necessitating further investigation. Objectives: To perform simultaneous quantitative analysis of five polyphenols in T. chebula and evaluate their anti-arthritic effects including antioxidant and anti-inflammatory activity in vitro. Materials and methods: Water, 50% water-ethanol, and pure ethanol were used as extract solvents. Quantitative analysis of gallic acid, corilagin, chebulanin, chebulagic acid, and ellagic acid in the three extracts was performed using high-performance liquid chromatography (HPLC). Antioxidant activity was assessed by the 2,2-diphenylpicrylhydrazyl (DPPH) radical-scavenging assay, and anti-inflammatory activity was evaluated by detecting interleukin (IL)-6 and IL-8 expression in IL-1β-stimulated MH7A cells. Results: The 50% water-ethanol solvent was the optimal solvent yielding the highest total polyphenol content, and the concentrations of chebulanin and chebulagic acid were much higher than those of gallic acid, corilagin, and ellagic acid in the extracts. The DPPH radical-scavenging assay showed that gallic acid and ellagic acid were the strongest antioxidative components, while the other three components showed comparable antioxidative activity. As for the anti-inflammatory effect, chebulanin and chebulagic acid significantly inhibited IL-6 and IL-8 expression at all three concentrations; corilagin and ellagic acid significantly inhibited IL-6 and IL-8 expression at high concentration; and gallic acid could not inhibit IL-8 expression and showed weak inhibition of IL-6 expression in IL-1β-stimulated MH7A cells. Principal component analysis indicated that chebulanin and chebulagic acid were the main components responsible for the anti-arthritic effects of T. chebula. Conclusion: Our findings highlight the potential anti-arthritic role of chebulanin and chebulagic acid from T. chebula.

Noninvasive Low-Frequency Pulsed Focused Ultrasound Therapy for Rheumatoid Arthritis in Mice

Rheumatoid arthritis (RA) is a common autoimmune disease characterized by chronic and progressive inflammation of the synovium. Focused ultrasound therapy is an increasingly attractive alternative for treating RA owing to its noninvasiveness; however, it remains unclear which immune subsets respond to ultrasound stimulation. In this study, we showed that spleen-targeted low-frequency pulsed focused ultrasound (LFPFU) effectively improved the severity of arthritis in an arthritis mouse model established in DBA/1J mice. Additionally, we performed in-depth immune profiling of spleen samples from RA mice, RA mice that underwent ultrasound therapy, and healthy controls using mass cytometry along with extensive antibody panels and identified the immune composition of 14 cell populations, including CD4+/CD8+ T cells, B cells, natural killer cells, and dendritic cells. Moreover, multidimensional analysis according to cell-surface markers and phenotypes helped in identifying 4 and 5 cell subpopulations among T and myeloid cells, respectively, with 6 T cell subsets and 3 myeloid cell subsets responsive to ultrasound therapy among the 3 groups. Of these cell subsets, CD8+ T cell subsets showed a unique response to ultrasound stimulation in RA mice. Specifically, CD8+ T cells show a noticeable correlation with the degree of arthritis progression and could serve as an indicator for spleen-focused ultrasound-based therapy. Furthermore, single-cell RNA sequencing of spleen cells revealed the importance of T, B, and myeloid cell populations in the anti-inflammatory pathway. These results elucidated the unique cell subsets and transcriptome of splenic cells responsive to LFPFU and demonstrated the potential of spleen-focused ultrasound stimulation in the treatment of inflammatory diseases.

Phenolic-Compound-Rich Opuntia littoralis Ethyl Acetate Extract Relaxes Arthritic Symptoms in Collagen-Induced Mice Model via Bone Morphogenic Markers

Rheumatoid arthritis (RA) is an autoimmune disease that causes inflammation and progressive joint dysfunction. Opuntia littoralis (OL) has a high nutritional content and is thought to offer a number of health advantages. We aimed to evaluate the anti-arthritic potential of OL extracts against collagen-induced arthritis (CIA). We designed three OL cladode fractions from the concentrated aqueous extract: hexane, ethyl acetate (EAE), and hydro alcohol (HAE). We investigated the nitric oxide and MDA levels of EAE against lipopolysaccharide-induced RAW264.7 cells; then, we administered EAE to the mice with CIA to confirm the anti-inflammatory effects against RA. HPLC analysis of the OL extracts showed a high concentration of phenolic compounds in EAE. Treatment with EAE (10 and 20 mg/100 g body weight of mice) after 10 days of immunization with collagen showed a significant inhibition of joint inflammation, paw swelling, and edemas. MDA and cytokine levels (IL-1β, IL-6R, IL-6, IL-17, and IL-23) were significantly reduced. EAE effectively ameliorated COX-2, NF-kB, STAT-3, PTEN, and RANKL expression. OL-EAE therapy significantly upregulated the expression of miR-28 and miR-199a. In conclusion, the anti-inflammatory actions of OL-EAE altered the cellular localization of the inflammatory mediators, therefore preventing joint inflammation via partial epigenetic and metabolic regulations in experimental mice.

Chymotrypsin attenuates adjuvant-induced arthritis by downregulating TLR4, NF-κB, MMP-1, TNF-α, IL-1β, and IL-6 expression in Sprague-Dawley rats

OBJECTIVE

Rheumatoid arthritis (RA) is mainly characterized by synovial hyperplasia, angiogenesis, inflammatory cells infiltration. Chymotrypsin is a proteolytic enzyme with anti-inflammatory effects. The current project was intended to test the efficacy and mechanism of chymotrypsin in adjuvant-induced arthritis (AIA) rats to provide an experimental basis for the clinical application of chymotrypsin.

METHODS

Sprague-Dawley rats were injected with complete Freund's adjuvant (CFA) in the hind left paw pad to establish an AIA model. Forty rats were randomly divided into five groups (n = 8): blank; CFA model (model); low-dose chymotrypsin (CLD), 0.53 mg/kg; high-dose chymotrypsin (CHD), 1.06 mg/kg; piroxicam, 10 mg/kg. The treatments were performed in the subplantar region of the left hind paw from Day 8 (D8) to Day 28 after adjuvant injection. The body weight, paw diameter, swelling degree of paw, and arthritic score were measured on D0, D7, D14, D21, and D28. All animals were sacrificed on D29. Subsequently, the synovial tissue of the ankle joint of the rats was stained with HE to generate pathological sections for observation of the pathological changes of synovial tissue from the ankle joint. The protein levels of MMP-1, TNF-α, IL-1β, and IL-6 in the rats' serum were determined by ELISA. Western blotting was used to detect the protein expression of TLR4 and NF-κB in the rat ankle tissue. The mRNA expression of TLR4, NF-κB, IL-1β, IL-6, and TNF-α in synovial tissue of the ankle joint was detected by RT-qPCR.

RESULTS

The body weight of the rats in each group showed an increasing trend, and there was no significant difference in weight between the groups. CHD and piroxicam suppressed paw swelling and arthritic scores and decreased synovial hyperplasia, inflammatory cell infiltration, pannus formation, and bone destruction. Furthermore, the overproduction of MMP-1, TNF-α, IL-1β, and IL-6 in serum was remarkably attenuated in the chymotrypsin- and piroxicam-treated rats. The protein levels of TLR4 and NF-κB in the synovial tissue of the chymotrypsin group and the piroxicam group were significantly lower than those in the model group. Likewise, the rats treated with chymotrypsin and piroxicam had a substantial decline in the mRNA expression of TLR4, NF-κB, TNF-α, IL-1β, and IL-6 in synovial tissue.

CONCLUSIONS

Chymotrypsin alleviates the joint damage of AIA rats, probably by reducing the expression of MMP-1, TNF-α, IL-1β, and IL-6 through TLR4/NF-κB signaling pathway.

Imbalance of Th17, Treg, and helper innate lymphoid cell in the peripheral blood of patients with rheumatoid arthritis

INTRODUCTION

Rheumatoid arthritis (RA) is a chronic inflammatory disease involving a variety of immune cells, including adaptive T and B cells and innate lymphoid cells (ILCs). Understanding the pathogenic role of these immune cells in RA provides new insights into the intervention and treatment of RA.

METHODS

A total of 86 patients with RA (RA group) and 50 healthy controls (HC) were included in the study. The immune cells of CD4+, CD19+ B, NK, Th17, Treg, ILCs, and their subsets (i.e., ILC1s, ILC2s, and ILC3s) were characterized in peripheral blood mononuclear cells by flow cytometry. Cytokines (i.e., IFN-γ, IL-4, IL-10, IL-17A, IL-22, and IL-33) in sera were detected using ELISA. The above immune cells and cytokines were analyzed in patients with different disease activity status and positive ( +) or negative ( -) rheumatoid factor (RF)/anti-citrullinated protein antibodies (ACPA).

RESULTS

Patients with RA had higher percentages of CD4+ T, CD19+ B, Th17, ILC2s, and ILC3s and lower percentages of Treg and ILC1s than HC. Patients with RA had elevated levels of IFN-γ, IL-4, IL-17A, and IL-22 and decreased level of IL-10. Compared with HC, patients with high disease activity had higher percentages of Th17, ILC2s, and ILC3s; lower percentages of ILC1s; and lower level of IL-10. The percentage of Treg cells in remission, low, moderate, and high disease activities decreased, whereas the level of IL-17A increased compared with HC. Furthermore, RF+ or ACPA+ patients exhibited elevated percentages of CD19+ B, ILC2s, and ILC3s and had decreased percentage of ILC1s and Treg cells than HC. The percentage of Th17 cells increased in RF-/ACPA- and RF+/ACPA+ patients. However, the above immune cells between RF or ACPA positive and negative patients were not significantly different.

CONCLUSION

Th17, Treg, and ILC subset dysregulations are present in patients with RA but may not be associated with conventionally defined seropositive RF and ACPA. Key Points • Th17, Treg, and ILC subset dysregulations are present in patients with RA but may reflect inflammation rather than specific diseases and stages. • No difference for the distribution of Th17, Treg, and ILC subsets between RF+ and RF- patients and between ACPA+ and ACPA- patients. The screening spectrum of RF and ACPA serology should be expanded to elucidate the role of immune cells in RA pathogenesis.

Oxidative stress and inflammation caused by 1-tetradecyl-3-methylimidazolium tetrafluoroborate in rat livers

The purpose of this study was to elucidate the mechanism underlying toxicity in the livers of male and female rats after treatment with 1-tetradecyl-3-methylimidazolium tetrafluoroborate ([C₁₄mim]BF₄, 0 [control], 12.5, 25, or 50 mg/kg) for 90 days. The results showed that [C₁₄mim]BF₄ exposure led to a high level of ROS and MDA in rat livers and the lower expression of Nrf2 and its downstream related antioxidant proteins. In addition, the expression of NF-κB p65 and the levels of inflammatory cytokines were upregulated in exposure groups rats' liver. After 30 days of cessation of exposure, the liver injury of rats in the 50 mg/kg exposure group was alleviated, and the above indicators were improved to varying degrees. The paper shows that [C₁₄mim]BF₄ could damage rat liver through oxidative stress and inflammatory pathway.

Nanoenzyme engineered neutrophil-derived exosomes attenuate joint injury in advanced rheumatoid arthritis via regulating inflammatory environment

Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by synovitis and destruction of cartilage, promoted by sustained inflammation. However, current treatments remain unsatisfactory due to lacking of selective and effective strategies for alleviating inflammatory environments in RA joint. Inspired by neutrophil chemotaxis for inflammatory region, we therefore developed neutrophil-derived exosomes functionalized with sub-5 nm ultrasmall Prussian blue nanoparticles (uPB-Exo) via click chemistry, inheriting neutrophil-targeted biological molecules and owning excellent anti-inflammatory properties. uPB-Exo can selectively accumulate in activated fibroblast-like synoviocytes, subsequently neutralizing pro-inflammatory factors, scavenging reactive oxygen species, and alleviating inflammatory stress. In addition, uPB-Exo effectively targeted to inflammatory synovitis, penetrated deeply into the cartilage and real-time visualized inflamed joint through MRI system, leading to precise diagnosis of RA in vivo with high sensitivity and specificity. Particularly, uPB-Exo induced a cascade of anti-inflammatory events via Th17/Treg cell balance regulation, thereby significantly ameliorating joint damage. Therefore, nanoenzyme functionalized exosomes hold the great potential for enhanced treatment of RA in clinic.

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uPB-Exo were firstly developed by combining NE-Exo with sub-5 nm ultrasmall PB nanoparticles via click chemistry.

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uPB-Exo selectively targeted inflamed joints via neutrophil-targeted biological molecules inherited from neutrophils.

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uPB-Exo accumulated in active FLS, and eventually scavenged reactive oxygen species and alleviated inflammatory stress.

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uPB-Exo induced a cascade of anti-inflammatory events via Th17/Treg cell balance regulation, thereby significantly ameliorating joint damage.

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uPB-Exo, as a drug free therapeutical agent, holds the great potential for enhanced treatment of RA in clinic.

Controlling Macrophage Polarization to Modulate Inflammatory Cues Using Immune-Switch Nanoparticles

The persistence of inflammatory mediators in tissue niches significantly impacts regenerative outcomes and contributes to chronic diseases. Interleukin-4 (IL4) boosts pro-healing phenotypes in macrophages (Mφ) and triggers the activation of signal transducer and activator of transcription 6 (STAT6). Since the IL4/STAT6 pathway reduces Mφ responsiveness to inflammation in a targeted and precise manner, IL4 delivery offers personalized possibilities to overcome inflammatory events. Despite its therapeutic potential, the limited success of IL4-targeted delivery is hampered by inefficient vehicles. Magnetically assisted technologies offer precise and tunable nanodevices for the delivery of cytokines by combining contactless modulation, high tissue penetration, imaging features, and low interference with the biological environment. Although superparamagnetic iron oxide nanoparticles (SPION) have shown clinical applicability in imaging, SPION-based approaches have rarely been explored for targeted delivery and cell programming. Herein, we hypothesized that SPION-based carriers assist in efficient IL4 delivery to Mφ, favoring a pro-regenerative phenotype (M2φ). Our results confirmed the efficiency of SPION-IL4 and Mφ responsiveness to SPION-IL4 with evidence of STAT6-mediated polarization. SPION-IL4-treated Mφ showed increased expression of M2φ associated-mediators (IL10, ARG1, CCL2, IL1Ra) when compared to the well-established soluble IL4. The ability of SPION-IL4 to direct Mφ polarization using sophisticated magnetic nanotools is valuable for resolving inflammation and assisting innovative strategies for chronic inflammatory conditions.

Liposome-mediated small RNA delivery to convert the macrophage polarity: A novel therapeutic approach to treat inflammatory uterine disease

Macrophages are present in all tissues for maintaining tissue homeostasis, and macrophage polarization plays a vital role in alleviating inflammation. Therefore, specific delivery of polarization modulators to macrophages in situ is critical for treating inflammatory diseases. We demonstrate that a size-controlled miRNA-encapsulated macrophage-targeting liposomes (miR/MT-Lip) specifically targets macrophages to promote M1-to-M2 polarization conversion, alleviating inflammation without cytotoxicity. miR/MT-Lip, approximately 1.2 μm, showed excellent internalization through phagocytosis and/or macropinocytosis in macrophages. miR-10a/MT-Lip, but not scramble miR-Fluorescein amidite (FAM)/MT-Lip as control, effectively converted the polarization of lipopolysaccharide (LPS)-induced M1 macrophages to M2 in vitro. When miR-10a/MT-Lip was intravenously delivered to mice insulted with LPS for inflammation, the proportion of M2 macrophages was significantly increased without disturbing the population of other immune cells. Furthermore, scramble miR-FAM/MT-Lip was mainly detected in macrophages, but not other immune cells. When our miR/MT-Lip was administered to mice with Asherman's syndrome that suffer from infertility because of sterile uterine inflammation, macrophage-specific targeting of miR-10a/MT-Lip facilitated M1-to-M2 conversion for angiogenesis in the impaired uterus, resulting in restoration of healthy uterine conditions. The results indicate that our MT-Lip encapsulating small RNAs has excellent potential to treat various inflammatory disorders by fine-tuning macrophage polarization in vivo without any side effects.

Engineered Platelet Microparticle-Membrane Camouflaged Nanoparticles for Targeting the Golgi Apparatus of Synovial Fibroblasts to Attenuate Rheumatoid Arthritis

Synovial fibroblasts in rheumatoid arthritis (RA) joints mediate synovial hyperplasia, progressive joint destruction, and the potential spread of disease between joints by producing multiple pathogenic proteins. Here, we deliver all-trans retinoic acid (ATRA) to selectively down-regulate these pathogenic factors, with a Golgi-targeting platelet microparticle-mimetic nanoplatform (termed Gol-PMMNP) which comprises a nanoparticle core and a platelet microparticle membrane coating labeled with a Golgi apparatus-targeting peptide. Gol-PMMNPs are shown to target synovial fibroblasts derived from RA patients via integrin α2β1-mediated endocytosis and accumulate in the Golgi apparatus by retrograde transport. ATRA-loaded Gol-PMMNPs (ATRA-Gol-PMMNPs) cause structural disruption of the Golgi apparatus, leading to an efficient reduction of pathogenic protein secretion in RA synovial fibroblasts. In rats with collagen-induced arthritis, Gol-PMMNPs display an arthritic joint-specific distribution, and ATRA-Gol-PMMNPs effectively reduce concentrations of pathogenic factors therein, including inflammatory cytokines, chemokines, and matrix-degrading enzymes within these joints. Additionally, ATRA-Gol-PMMNP treatment results in inflammatory remission and decreased bone erosion in both arthritic and proximal joints. Furthermore, ATRA-Gol-PMMNPs induce negligible toxicity to major organs. Taken together, ATRA-Gol-PMMNPs inhibit the progression of RA through reducing the production of multiple pathogenic mediators by synovial fibroblasts.

Predictive value of the TyG index and rheumatoid factor for cardiovascular disease risk in a rheumatoid arthritis population: data from a survey of 418 patients

Objective

To investigate the correlation between the triglyceride-glucose (TyG) index and rheumatoid factor levels and the existence of cardiovascular disease in patients in the rheumatoid arthritis population and to analyze their potential value in predicting the risk of cardiovascular disease.

Methods

Patients with rheumatoid arthritis treated by the Traditional Chinese Medicine Department of Rheumatism of the China-Japan Friendship Hospital from 2019–01 to 2021–12 were included in this retrospective study. Regression analysis was performed with multifactor-corrected multimodal logistic models to observe the correlation between the TyG index and rheumatoid factor and cardiovascular disease risk, construct predictive models and assess the potential predictive value of the variables on cardiovascular disease risk with receiver operating characteristic curves. The results were further corrected by sensitivity analysis and trend tests.

Results

A total of 418 patients with rheumatoid arthritis were included in the study. In the rheumatoid arthritis population, high rheumatoid factor (OR = 1.002, 95% CI = 1.001–1.002, P < 0.001), high TyG index (OR = 1.057, 95% CI = 1.008–1.109, P = 0.022), advanced age (OR = 1.080, 95% CI = 1.050–1.112, P < 0.001), and low physical activity (OR = 2.848, 95% CI = 1.195–6.785, P = 0.018) were independent risk factors for the existence of cardiovascular disease in patients. The combined coefficient calculated on the basis of the TyG index and rheumatoid factor was used to plot the receiver operating characteristic curve with an area under the curve of 0.791, which can be used to predict the potential risk of cardiovascular disease in patients with rheumatoid arthritis. Further sensitivity analysis found that the marker of focus remained associated with cardiovascular disease risk in a high-physical activity population with rheumatoid arthritis. The final trend test found a linear trend between the TyG index, rheumatoid factor levels and the risk of cardiovascular disease.

Conclusion

In the rheumatoid arthritis population, the TyG index and rheumatoid factor have some potential predictive value in determining the risk of cardiovascular disease, and the predictive efficacy is better when the two tests are combined.

EC-18 prevents autoimmune arthritis by suppressing inflammatory cytokines and osteoclastogenesis

Background

EC-18, a synthetic monoacetyldiaglyceride, exhibits protective effects against lung inflammation, allergic asthma, and abdominal sepsis. However, there have been no investigations to determine whether EC-18 has preventive potential in autoimmune diseases, especially rheumatoid arthritis (RA).

Methods

To investigate the efficacy of EC-18 on the development of RA, EC-18 was administered in a collagen-induced arthritis (CIA) murine model and disease severity and the level of inflammatory cytokines in the joint were investigated. The effect of EC-18 on the inflammation-related factors was investigated by flow cytometry, ELISA, western blot, and real-time PCR in splenocytes from mice and in peripheral blood mononuclear cells from healthy and patients with RA. The effect of EC-18 on osteoclastogenesis was investigated.

Results

EC-18 effectively reduced the clinical and histological severity of arthritis, similar to Janus kinase inhibitors include tofacitinib and baricitinib, in CIA. Furthermore, EC-18 exhibited a synergistic effect with methotrexate in preventing CIA. Treatment with EC-18 effectively reduced the production of inflammatory cytokines in immune cells and osteoclast differentiation in mice and patients with RA.

Conclusion

These results suggest that EC-18 may be an effective strategy for RA.

IL-31 and IL-33 in rheumatoid arthritis patients

Objective – to investigate clinical and diagnostic significance of IL-31 and IL-33 determination in patients with rheumatoid arthritis (RA).

Material and methods. 154 patients with a reliable diagnosis of RA were examined. Serum levels of IL-31 and IL-33 were studied using multiplex xMAP technology on Bio-PlexTM 200 System analyzer (BIO-RAD, USA). The upper limit of the norm in the study of 20 healthy donor sera was (M+3σ): IL-31 – 15.08 pg/ml, IL-33 – 3.40 pg/ml.

Results. IL-31 (Me (25th; 75th percentile) – 13.75 (5.63; 308.52) and 6.10 (2.87; 8.62) pg/ml (p<0.001), IL-33 – 18.86 (7.45; 65.95) and 0.52 (0.17; 0.78) pg/ml (p><0.001) levels were observed in RA patients in comparison with the control group. An increase in IL-33 concentration (more than 3.40 pg/ml) was observed in 87.0% of patients, and IL-31 (more than 15.08 pg/ml) in 48.1% of patients with RA. An increase in IL-33 alone was observed in 42.2% (65 of 154 patients) with RA, while an isolated increase in IL-31 concentration was observed in only 2 (1.3%) patients. Simultaneous hyperproduction of IL-33 and IL-31 occurred in 69 (44.9%) patients. We revealed positive correlation of clinical and laboratory parameters of RA with cytokine concentration: SDAI correlated with IL-33 (r=0.36; p><0.05); CRP – with IL-31 (r=0.49; p><0,05) and IL-33 (r=0.40; p><0.05). Conclusion. Concentrations of IL-31 and IL-33 are elevated in RA patients and correlate with the indices of inflammatory activity of the disease.>< 0.001), IL-33 – 18.86 (7.45; 65.95) and 0.52 (0.17; 0.78) pg/ml (p<0.001) levels were observed in RA patients in comparison with the control group. An increase in IL-33 concentration (more than 3.40 pg/ml) was observed in 87.0% of patients, and IL-31 (more than 15.08 pg/ml) in 48.1% of patients with RA. An increase in IL-33 alone was observed in 42.2% (65 of 154 patients) with RA, while an isolated increase in IL-31 concentration was observed in only 2 (1.3%) patients. Simultaneous hyperproduction of IL-33 and IL-31 occurred in 69 (44.9%) patients. We revealed positive correlation of clinical and laboratory parameters of RA with cytokine concentration: SDAI correlated with IL-33 (r=0.36; p><0.05); CRP – with IL-31 (r=0.49; p><0,05) and IL-33 (r=0.40; p><0.05). Conclusion. Concentrations of IL-31 and IL-33 are elevated in RA patients and correlate with the indices of inflammatory activity of the disease.>< 0.001) levels were observed in RA patients in comparison with the control group. An increase in IL-33 concentration (more than 3.40 pg/ml) was observed in 87.0% of patients, and IL-31 (more than 15.08 pg/ml) in 48.1% of patients with RA. An increase in IL-33 alone was observed in 42.2% (65 of 154 patients) with RA, while an isolated increase in IL-31 concentration was observed in only 2 (1.3%) patients. Simultaneous hyperproduction of IL-33 and IL-31 occurred in 69 (44.9%) patients. We revealed positive correlation of clinical and laboratory parameters of RA with cytokine concentration: SDAI correlated with IL-33 (r=0.36; p<0.05); CRP – with IL-31 (r=0.49; p><0,05) and IL-33 (r=0.40; p><0.05). Conclusion. Concentrations of IL-31 and IL-33 are elevated in RA patients and correlate with the indices of inflammatory activity of the disease.>< 0.05); CRP – with IL-31 (r=0.49; p< ,05) and IL-33 (r=0.40; p<0.05)

Conclusion. Concentrations of IL-31 and IL-33 are elevated in RA patients and correlate with the indices of inflammatory activity of the disease.

Nanozyme-reinforced hydrogel as a H2O2-driven oxygenerator for enhancing prosthetic interface osseointegration in rheumatoid arthritis therapy

Stem cell-based therapy has drawn attention for enhancing the osseointegration efficiency after joint replacement in the rheumatoid arthritis (RA). However, therapeutic efficacy of this approach is threatened by the accumulated reactive oxygen species (ROS) and poor oxygen supply. Herein, we develop a nanozyme-reinforced hydrogel for reshaping the hostile RA microenvironment and improving prosthetic interface osseointegration. The engineered hydrogel not only scavenges endogenously over-expressed ROS, but also synergistically produces dissolved oxygen. Such performance enables the hydrogel to be utilized as an injectable delivery vehicle of bone marrow-derived mesenchymal stem cells (BMSCs) to protect implanted cells from ROS and hypoxia-mediated death and osteogenic limitation. This nanozyme-reinforced hydrogel encapsulated with BMSCs can alleviate the symptoms of RA, including suppression of local inflammatory cytokines and improvement of osseointegration. This work provides a strategy for solving the long-lasting challenge of stem cell transplantation and revolutionizes conventional intervention methods for improving prosthetic interface osseointegration in RA.

lncRNA-mediated synovitis in rheumatoid arthritis: A perspective for biomarker development

Long noncoding RNAs (lncRNAs) are a regulatory class of noncoding RNAs with a wide range of activities such as transcriptional and post-transcriptional regulations. Emerging evidence has demonstrated that various lncRNAs contribute to the initiation and progression of Rheumatoid Arthritis (RA) through distinctive mechanisms. The present study reviews the recent findings on lncRNA role in RA development. It focuses on the involvement of different lncRNAs in the main steps of RA pathogenesis including T cell activation, cytokine dysregulation, fibroblast-like synoviocyte (FLS) activation and joint destruction. Besides, it discusses the current findings on RA diagnosis and the potential of lncRNAs as diagnostic, prognostic and predictive biomarkers in Rheumatology clinic.

TAFA4-IL-10 axis potentiate immunotherapy for airway allergy by induction of specific regulatory T cells

Allergen-specific immunotherapy (AIT) is the main treatment for allergic diseases. The therapeutic efficacy of AIT has to be improved. Neuropeptides, such as TAFA4, have immune-regulating features. The objective of this study is to promote the efficacy of AIT in experimental allergic rhinitis (AR) by the concurrent use of TAFA chemokine as a family member 4 (TAFA4). In this study, an AR mouse model was developed using ovalbumin (OVA) as the specific antigen. The AR response was assessed in mice after treatment with AIT or/and TAFA4. We found that exposure to TAFA4 activated dendritic cells (DCs) in the airway tissues. Activation of DC by TAFA4 resulted in the expression of IL-10. TAFA4 also promoted the activities of c-Maf inducing protein. The FPR1-MyD88-AKT signal pathway was associated with the TAFA4-induced Il10 expression in the DCs. Co-administration of AIT/TAFA4 attenuated the AR response in mice by inducing antigen-specific Tr1 cells. In conclusion, TAFA4 induces the expression of IL-10 in DCs. Acting as an adjuvant, TAFA4 significantly improves AIT’s therapeutic efficacy against AR by inducing antigen-specific Tr1 cells.

Meta-analysis for Association of Interleukin 4 VNTR Polymorphism with Rheumatoid Arthritis Risk and Severity

Rheumatoid Arthritis (RA) is a chronic autoimmune disease characterized by severe joint pain. There are conflicting results for the association of Interleukin 4 (IL4) variable number tandem repeats (VNTR; rs8179190) polymorphism with RA. Therefore, we performed a meta-analysis of the available studies to investigate the association of IL4 VNTR polymorphism with RA risk and severity in the overall populations and Asian, Egyptian, European, and Turkish ethnicities by sub-group analyses. Eight studies involving 1993 RA patients and 1732 controls were included in this meta-analysis. We found increased RA risk for the susceptible "R2R2" genotype and "R2" allele under heterozygous, recessive, and allelic models in the Asian populations (p < 0.00001, p < 0.0001, p = 0.001). We observed a significant association between "R2R2" genotype and "R2" allele for RA protection in the Turkish population under heterozygous, recessive, and allelic models (p = 0.01, p = 0.004, p = 0.002). Disease severity-based analysis revealed significant association for "R2R2" genotype and "R2" allele with RA severity under homozygous, heterozygous, recessive, dominant, and allelic models(p = 0.0004, p = 0.03, p = 0.02, p = 0.003, p = 0.01), specifically in Asian populations (p = 0.009, p = 0.02, p = 0.003, p = 0.03, p = 0.01) and under heterozygous, dominant, and allelic genetic models in Egyptian (p = 0.0001, p < 0.0001, p < 0.0001) and European (p = 0.002, p = 0.0007, p = 0.0006) populations. In silico analysis suggested that the susceptible "R2" allele changes the RNA secondary structure to a stable form by changing minimum free energy(ΔG) from - 115.20 to - 136.40 kcal/mol, which might lead to increased stability of IL-4 in RA patients. Overall, the meta-analysis suggests for the involvement of susceptible "R2" allele with RA risk in the Asian populations, RA severity in the overall populations (specifically in Asian, Egyptian, & European populations), and RA protection in the Turkish population.

Microbe-Derived Antioxidants Reduce Lipopolysaccharide-Induced Inflammatory Responses by Activating the Nrf2 Pathway to Inhibit the ROS/NLRP3/IL-1β Signaling Pathway

Inflammation plays an important role in the innate immune response, yet overproduction of inflammation can lead to a variety of chronic diseases associated with the innate immune system; therefore, modulation of the excessive inflammatory response has been considered a major strategy in the treatment of inflammatory diseases. Activation of the ROS/NLRP3/IL-1β signaling axis has been suggested to be a key initiating phase of inflammation. Our previous study found that microbe-derived antioxidants (MA) are shown to have excellent antioxidant and anti-inflammatory properties; however, the mechanism of action of MA remains unclear. The current study aims to investigate whether MA could protect cells from LPS-induced oxidative stress and inflammatory responses by modulating the Nrf2-ROS-NLRP3-IL-1β signaling pathway. In this study, we find that MA treatment significantly alleviates LPS-induced oxidative stress and inflammatory responses in RAW264.7 cells. MA significantly reduce the accumulation of ROS in RAW264.7 cells, down-regulate the levels of pro-inflammatory factors (TNF-α and IL-6), inhibit NLRP3, ASC, caspase-1 mRNA, and protein levels, and reduce the mRNA, protein levels, and content of inflammatory factors (IL-1β and IL-18). The protective effect of MA is significantly reduced after the siRNA knockdown of the NLRP3 gene, presumably related to the ability of MA to inhibit the ROS-NLRP3-IL-1β signaling pathway. MA is able to reduce the accumulation of ROS and alleviate oxidative stress by increasing the content of antioxidant enzymes, such as SOD, GSH-Px, and CAT. The protective effect of MA may be due to its ability of MA to induce Nrf2 to enter the nucleus and initiate the expression of antioxidant enzymes. The antioxidant properties of MA are further enhanced in the presence of the Nrf2 activator SFN. After the siRNA knockdown of the Nrf2 gene, the antioxidant and anti-inflammatory properties of MA are significantly affected. These findings suggest that MA may inhibit the LPS-stimulated ROS/NLRP3/IL-1β signaling axis by activating Nrf2-antioxidant signaling in RAW264.7 cells. As a result of this study, MA has been found to alleviate inflammatory responses and holds promise as a therapeutic agent for inflammation-related diseases.

Regulatory role of KCa3.1 in immune cell function and its emerging association with rheumatoid arthritis

Rheumatoid arthritis (RA) is a common autoimmune disease characterized by chronic inflammation. Immune dysfunction is an essential mechanism in the pathogenesis of RA and directly linked to synovial inflammation and cartilage/bone destruction. Intermediate conductance Ca²⁺-activated K⁺ channel (KCa3.1) is considered a significant regulator of proliferation, differentiation, and migration of immune cells by mediating Ca²⁺ signal transduction. Earlier studies have demonstrated abnormal activation of KCa3.1 in the peripheral blood and articular synovium of RA patients. Moreover, knockout of KCa3.1 reduced the severity of synovial inflammation and cartilage damage to a significant extent in a mouse collagen antibody-induced arthritis (CAIA) model. Accumulating evidence implicates KCa3.1 as a potential therapeutic target for RA. Here, we provide an overview of the KCa3.1 channel and its pharmacological properties, discuss the significance of KCa3.1 in immune cells and feasibility as a drug target for modulating the immune balance, and highlight its emerging role in pathological progression of RA.

Traditional Tibetan medicine: therapeutic potential in rheumatoid arthritis

Rheumatoid arthritis (RA) is a severe inflammatory autoimmune disease characterized by the failed spontaneous resolution of inflammation. The induction of immune regulation and resolution of inflammatory pathways are effective in alleviating inflammation in RA. As the oldest medical system in the world, traditional Tibetan medicine (TTM) has a long history of preventing and treating RA. This review provides a comprehensive overview of medicinal plants with anti-RA activity in the TTM system, using classic books of Tibetan medicine, modern research literature, and drug standards. A total of 27 species have been found to be effective in treating RA, including Tinospora sinensis (Lour.) Merr., Terminalia chehula Retz., P. hookeri (C. B. Clarke) Hock.), and Aconitum pendulum Busch. Alkaloids, flavonoids, polyphenols, and terpenoids have turned out to be the major bioactive components for RA treatment. The inhibition of pro-inflammatory cytokine expression by mediating the NF-κB, MAPK, and JAK/STAT pathways is the core mechanism in RA treatment. In conclusion, this review provides key information and research perspectives for further research on the anti-RA effects of TTM.

Mechanism of Emodin in the Treatment of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic, systemic, and autoimmune disease, and its main pathological changes are inflammatory cell infiltration accompanied by the secretion and accumulation of a variety of related cytokines, which induce the destruction of cartilage and bone tissue. Therefore, the modulation of inflammatory cells and cytokines is a key therapeutic target for controlling inflammation in RA. This review details the effects of emodin on the differentiation and maturation of T lymphocytes, dendritic cells, and regulatory T cells. In addition, the systematic introduction of emodin directly or indirectly affects proinflammatory cytokines (TNF-α, IL-6, IL-1, IL-1β, IL-17, IL-19, and M-CSF) and anti-inflammatory cytokines (the secretion of IL-4, IL-10, IL-13, and TGF-β) through the coregulation of a variety of inflammatory cytokines to inhibit inflammation in RA and promote recovery. Understanding the potential mechanism of emodin in the treatment of RA in detail provides a systematic theoretical basis for the clinical application of emodin in the future.

Heilaohuacid G, a new triterpenoid from Kadsura coccinea inhibits proliferation, induces apoptosis, and ameliorates inflammation in RA-FLS and RAW 264.7 cells via suppressing NF-𝜅B pathway

Heilaohu, the roots of Kadsura coccinea, has been used in Tujia ethnomedicine to treat rheumatic arthritis (RA). Heilaohuacid G (1), a new 3,4-seco-lanostane type triterpenoid isolated from the ethanol extract of Heilaohu, whose structure was determined using HR-ESI-MS data, NMR spectroscopic analyses, and ECD calculations. In this study, our purpose is to elucidate the mechanisms of Heilaohuacid G in the treatment of RA by inhibited proliferation of rheumatoid arthritis-fibroblastoid synovial (RA-FLS) cells and inhibited the inflammatory reactions in LPS-induced RA-FLS and RAW 264.7 cell lines via inhibiting NF-κB pathway. The biological activity screening experiments indicated that Heilaohuacid G significantly inhibited proliferation of RA-FLS cells with IC50 value of 8.16 ± 0.47 μM. CCK-8 assay, ELISA, flow cytometry assay, and Western blot were used to measure the changes of cell viability, apoptosis, and the release of inflammatory cytokines. Heilaohuacid G was found not only induced RA-FLS cell apoptosis, but also inhibited the inflammatory reactions in LPS-induced RA-FLS and RAW 264.7 cell lines via inhibiting NF-κB pathway. Furthermore, Heilaohuacid G (p.o.) at doses of 3.0, 6.0, and 12.0 mg/kg and the ethanol extracts of Heilaohu (p.o.) at doses of 200, 400, and 800 mg/kg both were confirmed antiinflammatory effects on xylene-induced ear mice edema model.

BNT162b2 coronavirus disease-2019 vaccination accelerated rheumatoid arthritis disease activity in chronic eosinophilic pneumonia: A case report

RATIONALE

The relationship between rheumatoid arthritis (RA) and eosinophilic inflammation is unclear. According to recent studies, it has been suggested that T helper 2 cell responses play a role in the inhibition of RA. It is unclear how the immunological response after coronavirus disease-2019 (COVID-19) vaccination affects T cell immune reactions.

PATIENT CONCERNS AND DIAGNOSES

Here, we report the case of an 88-year-old woman diagnosed with RA and chronic eosinophilic pneumonia (CEP). She was diagnosed with CEP about 20 years ago, and, through steroid treatment, she improved and had no relapse for 16 years. At the time of diagnosis of CEP, the rheumatoid factor (RF) was increased; however, there were no joint symptoms. After receiving the COVID-19 vaccine, joint and respiratory symptoms gradually worsened. Laboratory examinations showed increased RF, anti-cyclin citrullinated peptide antibody, and peripheral absolute eosinophil count. Musculoskeletal ultrasonography showed synovitis.

INTERVENTION AND OUTCOME

Methylprednisolone pulse therapy improved respiratory and joint symptoms immediately; RA and CEP stabilized with no relapses.

LESSONS

Eosinophilic and rheumatoid reactions following COVID-19 vaccination were an-reported adverse events. Eosinophilic inflammation might be reflected on an anti-inflammatory reaction in initial phase of RA.

E3 ubiquitin ligases STUB1/CHIP contributes to the Th17/Treg imbalance via the ubiquitination of aryl hydrocarbon receptor in rheumatoid arthritis

STIP1-homologous U-Box containing protein 1 (STUB1) is involved in the development of immune pathologies and the regulation of T cell. However, the potential role of STUB1 in the pathogenesis of rheumatoid arthritis (RA), especially in the regulation of T cells, remains elusive. Here we show that STUB1 promotes the imbalance of Th17/Treg cells through non-degradative ubiquitination of aryl hydrocarbon receptor (AHR). Using Western blot and flow cytometry analysis, we observe that the level of STUB1 was increased in RA patients compared with healthy controls. In particular, the expression of STUB1 protein was different in Th17 cells and Treg cells of RA patients. We also demonstrated that STUB1 facilitates Th17/Treg imbalance by up- or downregulating the expression of STUB1. In a subsequent series of in vitro experiments, we revealed that STUB1 promoted the imbalance of Th17 and Treg cells through non-degradative ubiquitination of AHR. Both knockdown of the AHR expression by siRNA and assays of CYP1A1 enzymatic activity by ethoxyresorufin-O-deethylase (EROD) supported this conclusion. Furthermore, we explored the ubiquitination sites of AHR responsible for STUB1-mediated ubiquitination and revealed that STUB1 promotes ubiquitination of AHR via K63 chains. Together, STUB1 may induce the imbalance of Th17/Treg cells via ubiquitination of AHR and serve as a potential therapeutic target for RA.

LncRNA HOTAIR inhibits the progression of fibroblast-like synoviocytes by sponging miRNA-106b-5p in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic progressive autoimmune disease of unknown etiology. Human fibroblast-like synoviocytes (HFLSs) are the main effector cells for synovial hyperplasia and invasion in RA. Long non-coding RNAs (lncRNAs) play key roles in several autoimmune diseases, including RA. We investigated the effects of lncRNA HOX transcript antisense intergenic RNA (HOTAIR) on the pathological behavior of HFLSs in RA. The microRNAs (miRNAs) with potential binding sites for lncRNA HOTAIR were predicted using Starbase v2.0. TargetScan (http://www.targetscan.org) was used to analyze the potential target genes of miR-106b-5p. The interactions were further verified using a dual-luciferase reporter assay. RNA and protein expression was determined using quantitative reverse transcription polymerase chain reaction (qRT-PCR) and western blotting. The proliferation, cell invasion and migration, and cell apoptosis of HFLSs in RA was detected by the 3-(4,5-dimethylthiazol)-2,5-diphenyl-tetrazolium bromide (MTT) assay, transwell assay, and flow cytometry (FCM). The dual luciferase reporter assay confirmed the interactions between lncRNA HOTAIR and miR-106b-5p and between miR-106b-5p and SMAD family member 7 (SMAD7). The qRT-PCR results indicated that the expression of lncRNA HOTAIR was markedly decreased and that of miR-106b-5p was markedly increased in HFLSs of RA. Cell proliferation, invasion, and migration of HFLSs were inhibited by lncRNA HOTAIR upregulation, and the expression of miR-106b-5p was negatively regulated by lncRNA HOTAIR in HFLSs. Apoptosis of HFLS cells was improved by the overexpression of lncRNA HOTAIR. All the effects of lncRNA HOTAIR upregulation on HFLSs were reversed after the overexpression of miR-106b-5p. Smad7 was identified as a target gene of miR-106b-5p, and the effects of downregulation of miR-106b-5p on HFLSs could be abolished by silencing Smad7. We found that lncRNA HOTAIR was significantly downregulated in the HFLSs of patients with RA. Moreover, lncRNA HOTAIR influenced cell growth, migration, invasion, and apoptosis in HFLSs through the miR-106b-5p/Smad7 axis.

Mesenchymal stem cell-derived exosome-educated macrophages alleviate systemic lupus erythematosus by promoting efferocytosis and recruitment of IL-17+ regulatory T cell

Background

Anti-inflammatory polarized macrophages are reported to alleviate systemic lupus erythematosus (SLE). Our previous studies have demonstrated that exosomes from adipose-derived stem cells promote the anti-inflammatory polarization of macrophages. However, the possible therapeutic effect of exosomes from stem cells on SLE remains unexplored.

Methods

Exosomes were isolated from the conditioned medium of bone marrow-derived mesenchymal stem cells using ultrafiltration and size-exclusion chromatography and were identified by nanoparticle tracking analysis and immunoblotting of exosomal-specific markers. Macrophages were collected from the MRL/lpr mouse kidney. The phenotype of macrophages was identified by immunoblotting for intracellular markers-inducible nitric oxide synthase (iNOS) and arginase-1 (Arg-1), and flow cytometry for macrophage markers F4/80, CD86, CD206, B7H4, and CD138. Pristane-induced murine lupus nephritis models were employed for in vivo study.

Results

When macrophages from the kidney of the MRL/lpr mice were treated with exosomes from bone marrow-derived mesenchymal stem cells (BM-MSCs), the upregulation of CD206, B7H4, CD138, Arg-1, CCL20, and anti-inflammatory cytokines was observed, which suggested that the macrophages were polarized to a specific anti-inflammatory phenotype. These anti-inflammatory macrophages produced low levels of reactive oxygen species (ROS) but had a high efferocytosis activity and promoted regulatory T (T_reg) cell recruitment. Moreover, exosome injection stimulated the anti-inflammatory polarization of macrophages and increased the production of IL-17⁺ T_reg cells in a pristane-induced murine lupus nephritis model. We observed that exosomes from BMMSCs depleted of microRNA-16 (miR-16) and microRNA-21 (miR-21) failed to downregulate PDCD4 and PTEN in macrophages, respectively, and attenuated exosome-induced anti-inflammatory polarization.

Conclusion

Our findings provide evidence that exosomes from BMMSCs promote the anti-inflammatory polarization of macrophages. These macrophages alleviate SLE nephritis in lupus mice by consuming apoptotic debris and inducing the recruitment of T_reg cells. We identify that exosomal delivery of miR-16 and miR-21 is a significant contributor to the polarization of macrophages.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-03174-7.

Rheumatoid arthritis and mitochondrial homeostasis: The crossroads of metabolism and immunity

Rheumatoid arthritis is an autoimmune disease characterized by chronic symmetric synovial inflammation and erosive bone destruction. Mitochondria are the main site of cellular energy supply and play a key role in the process of energy metabolism. They possess certain self-regulatory and repair capabilities. Mitochondria maintain relative stability in number, morphology, and spatial structure through biological processes, such as biogenesis, fission, fusion, and autophagy, which are collectively called mitochondrial homeostasis. An imbalance in the mitochondrial homeostatic environment will affect immune cell energy metabolism, synovial cell proliferation, apoptosis, and inflammatory signaling. These biological processes are involved in the onset and development of rheumatoid arthritis. In this review, we found that in rheumatoid arthritis, abnormal mitochondrial homeostasis can mediate various immune cell metabolic disorders, and the reprogramming of immune cell metabolism is closely related to their inflammatory activation. In turn, mitochondrial damage and homeostatic imbalance can lead to mtDNA leakage and increased mtROS production. mtDNA and mtROS are active substances mediating multiple inflammatory pathways. Several rheumatoid arthritis therapeutic agents regulate mitochondrial homeostasis and repair mitochondrial damage. Therefore, modulation of mitochondrial homeostasis would be one of the most attractive targets for the treatment of rheumatoid arthritis.

Cytokine profiling in plasma distinguishes the histological inflammatory subtype of head and neck squamous cell carcinoma and a novel regulatory role of osteopontin

Head and neck squamous cell carcinoma (HNSCC) can be classified according to the histological inflammatory subtype (HIS) into inflamed (HIS-INF) or immune excluded (HIS-IE). HIS-IE was previously associated with higher levels of soluble Semaphorin 4D (HsS4D) in plasma, and higher transcriptional levels of osteopontin (OPN) in the tumor tissue, compared to HIS-INF. The goal of the current study is to investigate whether the HIS inflammatory subtype can be distinguished by a differential cytokine panel in peripheral blood. Retrospectively collected five HIS-INF and five HIS-IE tumor tissue with paired plasma were included in the study. Five healthy donors (HD) and five autoimmune/chronic inflammatory conditions (AI/CI) were controls. The ELISA-Luminex™ system was used to detect 40 traditional cytokines in plasma. Human cytokine array (104 cytokines) was used for the conditioned medium (CM) of the HNSCC HN6 cell line. Semaphorin 4D (Sema4D) siRNA and recombinant human osteopontin (rh-OPN) were used to investigate the effect of OPN on Sema4D expression. The HIS-IE cytokine profile was higher than HIS-INF but comparable to AI/CI. HIS-INF had the lowest cytokine levels. HIS-IE was differentially higher in IP-10 and IL8 compared to HD, while HIS-INF was higher in IL-10. Sema4D inhibition in HN6 resulted in a decrease of OPN in the CM of HN6, and treatment with rh-OPN rescued Sema4D in HN6 cell lysate and associated CM. In conclusion, the current work demonstrates a novel association between the HIS subtypes and a differential pattern of cytokine expression in plasma. These findings can open new avenues for HNSCC patient stratification and hence provide better personalized treatment.

The alarmins high mobility group box protein 1 and S100A8/A9 display different inflammatory profiles after acute knee injury

OBJECTIVE

To compare the concentrations of high mobility group box 1 protein (HMGB1) and S100A8/A9 in synovial fluid between patients with knee injuries and osteoarthritis (OA), and knee healthy subjects. To investigate associations of alarmin levels with different joint injuries and with biomarkers of inflammation, Wnt signaling, complement system, bone and cartilage degradation.

METHODS

HMGB1 and S100A8/A9 were measured in synovial fluid by immunoassays in patients with knee injuries, with OA and from knee healthy subjects, and were related to time from injury and with biomarkers obtained from previous studies. Hierarchical cluster and enrichment analyses of biomarkers associated to HMGB1 and S100A8/A9 were performed.

RESULTS

The synovial fluid HMGB1 and S100A8/A9 concentrations were increased early after knee injury; S100A8/A9 levels were negatively associated to time after injury and was lower in the old compared to recent injury group, while HMGB1 was not associated to time after injury. The S100A8/A9 levels were also increased in OA. The initial inflammatory response was similar between the alarmins, and HMGB1 and S100A8/A9 shared 9 out of 20 enriched pathways. The alarmins displayed distinct response profiles, HMGB1 being associated to cartilage biomarkers while S100A8/A9 was associated to proinflammatory cytokines.

CONCLUSIONS

HMGB1 and S100A8/A9 are increased as an immediate response to knee trauma. While they share many features in inflammatory and immunoregulatory mechanisms, S100A8/A9 and HMGB1 are associated to different downstream responses, which may have impact on the OA progression after acute knee injuries.

Potential role of ghrelin in the regulation of inflammation

Several diseases are caused or progress due to inflammation. In the past few years, accumulating evidence suggests that ghrelin, a gastric hormone of 28-amino acid residue length, exerts protective effects against inflammation by modulating the related pathways. This review focuses on ghrelin's anti-inflammatory and potential therapeutic effects in neurological, cardiovascular, respiratory, hepatic, gastrointestinal, and kidney disorders. Ghrelin significantly alleviates excessive inflammation and reduces damage to different target organs mainly by reducing the secretion of inflammatory cytokines, including interleukin-6 (IL-6), interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α), and inhibiting the nuclear factor kappa-B (NF-κB) and NLRP3 inflammasome signaling pathways. Ghrelin also regulates inflammation and apoptosis through the p38 MAPK/c-Jun N-terminal kinase (JNK) signaling pathway; restores cerebral microvascular integrity, and attenuates vascular leakage. Ghrelin activates the phosphoInositide-3 kinase (PI3K)/protein kinase B (Akt) pathway and inhibits inflammatory responses in cardiovascular diseases and acute kidney injury. Some studies show that ghrelin exacerbates colonic and intestinal manifestations of colitis. Interestingly, some inflammatory states, such as non-alcoholic steatohepatitis, inflammatory bowel diseases, and chronic kidney disease, are often associated with high ghrelin levels. Thus, ghrelin may be a potential new therapeutic target for inflammation-related diseases.

Diosmin and Trolox Have Anti-Arthritic, Anti-Inflammatory and Antioxidant Potencies in Complete Freund’s Adjuvant-Induced Arthritic Male Wistar Rats: Roles of NF-κB, iNOS, Nrf2 and MMPs

Rheumatoid arthritis (RA) is a chronic, progressive, autoimmune disease caused by a malfunction of the immune system. The aim of this study was to examine the anti-arthritic effects and suggest the mechanisms of actions of diosmin and trolox in male Wistar rats. Complete Freund’s adjuvant (CFA) was used to establish RA in the animals by subcutaneous injection of 100 µL CFA/rat into plantar region of right hind leg in two consecutive days. Diosmin and/or trolox were administered orally at a dosage of 20 mg/kg/day to CFA-induced arthritic rats for 2 weeks. The normal and arthritic control groups were orally given the same equivalent volume of a vehicle (1% carboxymethyl cellulose) in which treatment agents were dissolved. At the end of the experiment, blood samples were collected from the jugular vein for the detection of the total leukocyte count (TLC) and differential leukocyte count (DLC) in blood and the detection of rheumatoid factor (RF), anti-citrullinated protein antibodies (ACPA), tumor necrosis factor-α (TNF-α), interleukin-13 (IL-13), and interleukin-17 (IL-17) levels by enzyme-linked immunosorbent assay (ELISA), as well as markers of oxidative stress and the antioxidant defense system in serum. The right hind ankle regions of three rats from each group were dissected out and fixed in 10% neutral-buffered formalin for histological examination and the other three were kept at −30 °C for Western blot analysis of nuclear factor-kappa B (NF-κB) protein 50 (NF-κB p50), NF-κB p65, inducible nitric oxide synthase (iNOS), nuclear factor erythroid-2-related factor 2 (Nrf2), and matrix metalloproteinase (MMP)-1 (MMP-1), MMP-3, and MMP-9. The CFA injection was deleterious to the ankle joint’s histological architecture, manifesting as infiltration of inflammatory cells into the articular cartilage, hyperplasia of the synovium, and erosion of the cartilage. All these effects were ameliorated by diosmin and/or trolox, with the combined dose being the most effective. The two compounds significantly lowered the elevated serum levels of RF, ACPA, TNF-α, and IL-17, as well as other pro-inflammatory mediators, such as NF-κB p50, NF-κB p65, iNOS, MMP-1, MMP-3 and MMP-9. They also increased the levels of the anti-inflammatory cytokine, IL-13, and the cytoprotective transcription factor Nrf2. The compounds stimulated higher activities of antioxidants, such as glutathione, glutathione-S-transferase, catalase, and superoxide dismutase, and reduced lipid peroxidation in the serum of arthritic rats. In conclusion, diosmin, trolox, and their combination, which was the most potent, exerted anti-arthritic, anti-inflammatory and antioxidant effects by suppressing NF-κB signaling, inhibiting matrix metalloproteinases, and activating Nrf2.

Vitexin alleviates inflammation and enhances apoptosis through the regulation of the JAK/STAT/SOCS signaling pathway in the arthritis rat model

Rheumatoid arthritis (RA) is a chronic inflammatory and autoimmune disorder. RA is progressive and needs long-term treatment. Vitexin is a naturally-occurring flavonoid that is identified in various plant sources. Vitexin is demonstrated to produce antioxidant effects with numerous pharmacological activities. This experimental in vivo study assessed the antiarthritic and apoptotic role of a natural plant extract, vitexin, on RA. Collagen-induced arthritis (CIA) rat model Sprague Dawley males were grouped into five sets with six rats each: control, CIA, CIA + vitexin (10 mg/kg bw), CIA + Methotrexate (1 mg/kg bw), and vitexin (10 mg/kg bw) alone. The body weight, organ weight, biochemical assay, inflammatory enzymes, apoptosis, and cytokines levels were evaluated and compared among groups. Janus kinase (JAK)/signal transducer and activator of transcription (STAT)/suppressors of cytokine signaling (SOCS) levels and histopathology of ankle joints were also studied and compared. Significance was considered at a p < 0.05. Vitexin (10 mg/kg bw) significantly reduced the inflammatory enzyme markers, interleukin (IL)-1β, IL-6, IL-17, IL-4, IL-10, tumor necrosis factor-α, interferon-γ, and iNOS levels in arthritis rats (p < 0.05). Vitexin significantly improved collagen-induced arthritic histological changes (p < 0.05). Vitexin also reduced JAK/STAT expressions associated with inflammation and significantly increased elevated SOCS levels (p < 0.05). Aberration in apoptosis, inflammatory mediators, C-reactive protein, and rheumatoid factor levels in the arthritic rats reverted to normal with vitexin. These results emphasize that vitexin possesses anti-inflammatory and apoptotic activity via the regulation of JAK/STAT/SOCS signaling in CIA in a rat model. Hence, vitexin is a promising auxiliary drug for RA treatment.

DNA Origami as a Nanomedicine for Targeted Rheumatoid Arthritis Therapy through Reactive Oxygen Species and Nitric Oxide Scavenging

Rheumatoid arthritis (RA) severely threatens human health by causing inflammation, swelling, and pain in the joints and resulting in persistent synovitis and irreversible joint disability. In the development of RA, pro-inflammatory M1 macrophages, which express high levels of reactive oxygen species (ROS) and nitric oxide (NO), induce synovial inflammation and bone erosion. Eliminating ROS and NO in the inflamed joints is a potential RA therapeutic approach, which can drive the transition of pro-inflammatory M1 macrophages to the anti-inflammatory M2 phenotype. Taking advantage of the intrinsic ROS- and NO-scavenging capability of DNA molecules, herein, we report the development of folic acid-modified triangular DNA origami nanostructures (FA-tDONs) for targeted RA treatment. FA-tDONs could efficiently scavenge ROS and NO and actively target M1 macrophages, facilitating the M1-to-M2 transition and the recovery of associated cytokines and biomarkers to the normal level. The therapeutic efficacy of FA-tDONs was examined in the RA mouse model. As validated by appearance, histological, and serum examinations, FA-tDONs treatment effectively alleviated synovial infiltration and cartilage damage, attenuating disease progression. This study demonstrated the usage of DNA origami for RA treatment and suggested its potential in other antioxidant therapies.

Splenectomy modulates the immune response but does not prevent joint inflammation in a mouse model of RA

The spleen is the largest secondary lymphoid organ which is involved in the development of B cells and also in systemic (auto)immune responses. Using the recombinant human G1 domain-induced arthritis (GIA) model in splenectomized and control BALB/c mice, we investigated the role of the spleen in the induction and pathogenesis of autoimmune arthritis. Splenectomized mice developed GIA with a similar clinical picture to the control group. However, we observed significant alterations in the humoral and cellular immune responses in splenectomized mice. In the sera of the splenectomized mice, we found lower pro-inflammatory cytokine and anti-rhG1 IgM levels, but higher IL-4, anti-rhG1 IgG1 and anti-CCP and RF antibodies. The arthritis induction in the splenectomized group was associated with a significant expansion of activated helper T cells and an increase in the proportion of the circulating B1 and marginal zone B cell subsets. Importantly, immunization of the splenectomized mice with rhG1 induced the formation of germinal centers in the inguinal- and mesenteric lymph nodes (i/mLNs) which showed an active immune response to rhG1. Finally, both B and T cells from the mLNs of the splenectomized mice showed decreased intracellular Ca2+ signaling than those of the control group. Collectively, these findings indicate that the presence of the spleen is not critical for the induction of GIA, and in its absence the autoimmune arthritis is most likely promoted through the compensatory activity of the i/mLNs. However, our data implies the immunological role of the spleen in arthritis which could be further assessed in human RA.

Concerted regulation of OPG/RANKL/ NF‑κB/MMP-13 trajectories contribute to ameliorative capability of prodigiosin and/or low dose γ-radiation against adjuvant- induced arthritis in rats

BACKGROUND

Prodigiosin (PDG) is a microbial red dye with antioxidant and anti-inflammatory properties, although its effect on rheumatoid arthritis (RA) remains uncertain. Also, multiple doses of low dose γ- radiation (LDR) have been observed to be as a successful intervention for RA. Thus, the purpose of this study was to investigate the ameliorative potential of PDG and/or LDR on adjuvant-induced arthritis (AIA) in rats.

METHODS

The anti-inflammatory and anti-arthritic effects of PDG and/or LDR were examined in vitro and in vivo, respectively. In the AIA model, the arthritic indexes, paw swelling degrees, body weight gain, and histopathological assessment in AIA rats were assayed. The impact of PDG (200 µg/kg; p.o) and/or LDR (0.5 Gy) on the levels of pro- and anti-inflammatory cytokines (IL-1β, TNF-α, IL-6, IL-18, IL-17A, and IL-10) as well as the regulation of osteoprotegrin (OPG)/ receptor activator of nuclear factor κB ligand (RANKL)/ nuclear factor-κB (NF-κB)/MMP-13 pathways was determined. Methotrexate (MTX; 0.05 mg/kg; twice/week, i.p) was administered concurrently as a standard anti-arthritic drug.

RESULTS

PDG and/or LDR markedly diminished the arthritic indexes, paw edema, weigh loss in AIA rats, alleviated the pathological alterations in joints, reduced the levels of pro-inflammatory cytokines IL-1β, TNF-α, IL-6, IL-18, IL-17A, and RANKL in serum and synovial tissues, while increasing anti-inflammatory cytokines IL-10 and OPG levels. Moreover, PDG and/or LDR down-regulated the expression of RANKL, NF-κBp65, MMP13, caspase-3, and decreased the RANKL/OPG ratio, whereas OPG and collagen II were enhanced in synovial tissues.

CONCLUSION

PDG and/or LDR exhibited obvious anti-RA activity on AIA.

Update on imaging of the cervical spine in rheumatoid arthritis

Rheumatoid arthritis is a multisystem, autoimmune, inflammatory disorder with numerous musculoskeletal manifestations. Involvement of the cervical spine is common and may result in severe complications due to synovitis, erosions, pannus formation, spinal instability and ankylosis. The purpose of this article is to review the current role of imaging in the rheumatoid spine, with emphasis on radiographs and MRI.

Core-shell Pluronic F127/chitosan based nanoparticles for effective delivery of methotrexate in the management of rheumatoid arthritis

This study was designed to improve oral bioavailability of the methotrexate (MTX) by sustaining its release profile and integration into core-shell polymeric nanoparticles. The self-micellization and ionotropic gelation technique was employed which resulted into spherical shaped nanoparticles (181-417 nm) with encapsulation efficiency of 80.14% to 85.54%. Furthermore, Fourier Transform Infrared Spectroscopy and Differential Scanning Calorimetry analyses were carried out to investigate physicochemical and thermal stability of the produced engineered core shell nanoparticles of the methotrexate. . Entrapment of drug in polymeric core was confirmed by X-ray diffraction analysis. In-vitro sustained release behavior of nanoparticles was observed at pH 6.8 for 48 h while low drug release was observed at pH 1.2 due to pH-responsive nature of Pluronic F127. Acute toxicity study confirmed safety and biocompatible profile of nanoparticles. MTX loaded polymeric nanoparticles ameliorated the pharmacokinetic profile (8 folds greater half-life, 6.26 folds higher AUC_0-t and 3.48 folds higher mean residence time). In vivo study conducted in rat model depicted the improved therapeutic efficacy and healing of arthritis through MTX loaded polymeric nanoparticles, preferentially attributable to high accretion of MTX in the inflamed site. In conclusion, MTX loaded polymeric nanoparticles is an attractive drug delivery strategy for an effective management and treatment of rheumatoid arthritis.

Role of cryopreserved multipotent mesenchymal stromal cells in modulation of some indices of cell immunity in adjuvant arthritis

Inroduction

The results of experimental and clinical studies in recent years indicate that the transplantation of multipotent mesenchymal stromal cells (MMSCs) is a possible approach for the "restoration" of the immune system of patients with autoimmune diseases, in particular, rheumatoid arthritis. However, the strength and duration of the effect vary greatly, which indicates incomplete correction of the tested parameters, thereby opening up the prospect of improving this method of treatment by choosing dose-time parameters and methods of their administration. The aim of this research was to determine the indices of cellular immunity in animals with adjuvant arthritis and therapy with cryopreserved MMSCs derived from adipose and cartilage tissues.

Material and methods

Adjuvant arthritis in male rats was modeled by subplantar administration of Freund's complete adjuvant. On day 7 of modeling, experimental animals were administered with saline (control group) or cryopreserved MMSCs from adipose or cartilaginous tissue locally or generalized. On day 28 after therapy the body weight, spleen index and cellularity, and content of CD3+, CD4+, CD8+, CD4+CD25+ cells in the spleen were determined.

Results

In the control group of animals, the inflammation was pronounced, as evidenced by a significant increase in the studied parameters throughout the observation period. The use of cryopreserved MMSCs from adipose and cartilaginous tissues led to the restoration of T regulatory cells (Treg) on day 28. Generalized administration of cells had a more pronounced therapeutic effect compared to the animals with local administration. These data can be used to justify and develop a therapeutic approach to rheumatoid arthritis in clinical practice.

Conclusions

Cell therapy with cryopreserved MMSCs from investigated sources provided by both local and generalized administration to animals with adjuvant arthritis has a correcting effect on the cellular immunity.

Knowledge Domains and Emerging Trends of Osteoblasts-Osteoclasts in Bone Disease From 2002 to 2021: A Bibliometrics Analysis and Visualization Study

Background

Osteoblasts-Osteoclasts has been a major area in bone disease research for a long time. However, there are few systematic studies in this field using bibliometric analysis. We aimed to perform a bibliometric analysis and visualization study to determine hotspots and trends of osteoblasts-osteoclasts in bone diseases, identify collaboration and influence among authors, countries, institutions, and journals, and assess the knowledge base to develop basic and clinical research in the future.

Methods

We collected articles and reviews for osteoblasts-osteoclasts in bone diseases from the Web of Science Core Collection. In addition, we utilized scientometrics software (CiteSpace5.8 and VOSviewer1.6.18) for visual analysis of countries/regions, institutions, authors, references, and keywords in the field.

Results

In total, 16,832 authors from 579 institutions in 73 countries/regions have published 3,490 papers in 928 academic journals. The literature in this field is rapidly increasing, with Bone publishing the most articles, whereas Journal of Bone and Mineral Research had the most co-cited journals. These two journals mainly focused on molecular biology and the clinical medicine domain. The countries with the highest number of publications were the US and China, and the University of Arkansas for Medical Sciences was the most active institution. Regarding authors, Stavros C. Manolagas published the most articles, and Hiroshi Takayanagi had the most co-cited papers. Research in this field mainly includes molecular expression and regulatory mechanisms, differentiation, osteoprotection, inflammation, and tumors. The latest research hotspots are oxidative stress, mutation, osteocyte formation and absorption, bone metabolism, tumor therapy, and in-depth mechanisms.

Conclusion

We identified the research hotspots and development process of osteoblasts-osteoclasts in bone disease using bibliometric and visual methods. Osteoblasts-osteoclasts have attracted increasing attention in bone disease. This study will provide a valuable reference for researchers concerned with osteoblasts-osteoclasts in bone diseases.

Reprogramming Metabolism of Macrophages as a Target for Kidney Dysfunction Treatment in Autoimmune Diseases

Chronic kidney disease (CKD), as one of the main complications of many autoimmune diseases, is difficult to cure, which places a huge burden on patients’ health and the economy and poses a great threat to human health. At present, the mainstream view is that autoimmune diseases are a series of diseases and complications caused by immune cell dysfunction leading to the attack of an organism’s tissues by its immune cells. The kidney is the organ most seriously affected by autoimmune diseases as it has a very close relationship with immune cells. With the development of an in-depth understanding of cell metabolism in recent years, an increasing number of scientists have discovered the metabolic changes in immune cells in the process of disease development, and we have a clearer understanding of the characteristics of the metabolic changes in immune cells. This suggests that the regulation of immune cell metabolism provides a new direction for the treatment and prevention of kidney damage caused by autoimmune diseases. Macrophages are important immune cells and are a double-edged sword in the repair process of kidney injury. Although they can repair damaged kidney tissue, over-repair will also lead to the loss of renal structural reconstruction function. In this review, from the perspective of metabolism, the metabolic characteristics of macrophages in the process of renal injury induced by autoimmune diseases are described, and the metabolites that can regulate the function of macrophages are summarized. We believe that treating macrophage metabolism as a target can provide new ideas for the treatment of the renal injury caused by autoimmune diseases.

Transcriptomic profiling revealed the role of apigenin-4'-O-α-L-rhamnoside in inhibiting the activation of rheumatoid arthritis fibroblast-like synoviocytes via MAPK signaling pathway

BACKGROUND

Activated fibroblast-like synoviocyte (FLS) played a significant role in the pathogenesis and progression of rheumatoid arthritis (RA). Apigenin-4'-O-α-L-rhamnoside showed remarkable effects against RA, however, no relevant studies on pharmacology of apigenin-4'-O-α-L-rhamnoside yet, the effects and underlying molecular mechanism of apigenin-4'-O-α-L-rhamnoside on RA are still unclear.

PURPOSE

This study aimed to investigate the therapeutic effects and mechanisms of apigenin-4'-O-α-L-rhamnoside on RA-FLS cells by transcriptomic analysis.

METHODS

In vitro, RA-FLS cell viability and migration were measured by CCK-8 and scratch assays, respectively. The effects of apigenin-4'-O-α-L-rhamnoside on inflammatory levels of MMP-1, MMP-3, RANKL and TNF-α in RA-FLS cells were detected using ELISA kits. High-throughput transcriptome analysis was performed to screen the key genes and related pathways of apigenin-4'-O-α-L-rhamnoside inhibit RA-FLSs, and the result of which were validated by RT-qPCR and western blot. Furthermore, in vivo, we also evaluated the effects of apigenin-4'-O-α-L-rhamnoside in rat with CIA.

RESULTS

Apigenin-4'-O-α-L-rhamnoside significantly suppressed RA-FLS migration, exerted remarkable inhibiting effects on the expression levels on MMP-1, MMP3, RANKL and TNF-α in RA-FLS cells. It seemed that MAPK signaling pathway might be closely related to the pathogenesis of RA by down-regulated relevant core targets (MAPK1, HRAS, ATF-2, p38 and JNK). Moreover, apigenin-4'-O-α-L-rhamnoside attenuated the severity of arthritis in CIA rat.

CONCLUSION

Apigenin-4'-O-α-L-rhamnoside inhibited pro-inflammatory cytokine, chemokine and MMPs factors production of RA-FLS by targeting the MAPK signaling pathway, which provided a scientific basis for potential application in the treatment of RA.

The Herbal Combination of Radix astragali, Radix angelicae sinensis, and Caulis lonicerae Regulates the Functions of Type 2 Innate Lymphocytes and Macrophages Contributing to the Resolution of Collagen-Induced Arthritis

Type 2 innate lymphocytes (ILC2s), promoting inflammation resolution, was a potential target for rheumatoid arthritis (RA) treatment. Our previous studies confirmed that R. astragali and R. angelicae sinensis could intervene in immunologic balance of T lymphocytes. C. lonicerae also have anti-inflammatory therapeutic effects. In this study, the possible molecular mechanisms of the combination of these three herbs for the functions of ILC2s and macrophages contributing to the resolution of collagen-induced arthritis (CIA) were studied. Therefore, we used R. astragali, R. angelicae sinensis, and C. lonicerae as treatment. The synovial inflammation and articular cartilage destruction were alleviated after herbal treatment. The percentages of ILC2s and Tregs increased significantly. The differentiation of Th17 cells and the secretion of IL-17 and IFN-γ significantly decreased. In addition, treatment by the combination of these three herbs could increase the level of anti-inflammatory cytokine IL-4 secreted, active the STAT6 signaling pathway, and then contribute to the transformation of M1 macrophages to M2 phenotype. The combination of the three herbs could promote inflammation resolution of synovial tissue by regulating ILC2s immune response network. The synergistic effects of three drugs were superior to the combination of R. astragali and R. angelicae sinensis or C. lonicerae alone.

Network analysis combined with pharmacological evaluation strategy to reveal the mechanism of Tibetan medicine Wuwei Shexiang pills in treating rheumatoid arthritis

Tibetan medicine is an important part of traditional Chinese medicine and a significant representative of ethnic medicine in China. Tibetan medicine is gradually recognized by the world for its unique curative effects. Wuwei Shexiang pills (WPW) has been widely used to treat “Zhenbu” disease (Also known as rheumatoid arthritis) in Tibetan medicine, however, its potential bioactive ingredients and mechanism for RA treatment remain unclear. In this study, we used a combination of gas chromatography-mass spectrometry (GC-MS), ultra-performance liquid chromatography coupled with quadrupole time-of-fight mass spectrometry (UPLC-Q-TOF/MS), network analysis and experimental validation to elucidate the potential pharmacodynamic substances and mechanisms of WPW in the treatment of rheumatoid arthritis (RA). The results showed that songoramine, cheilanthifoline, saussureanine C, acoric acid, arjunolic acid, peraksine, ellagic acid, arjungenin and other 11 components may be the main activities of WPW in the treatment of RA. PIK3CA, AKT, MAPK, IL-6, TNF, MMP1, MMP3, and CDK1 are considered as core targets. PI3K-AKT, MAPK, apoptosis, cell cycle, and other signaling pathways may be the key pathways for WPW to play a role in the treatment of RA. Furthermore, we validated the underlying molecular mechanism of WPW predicted by network analysis and demonstrated its possible mechanism through in vivo animal experiments. It was found that WPW could significantly improve the degree of paw swelling, and reduce ankle joint diameter and arthritis index. Further histomorphological analysis showed that WPW could reduce the degree of synovial tissue inflammation and ankle joint cartilage damage. Meanwhile, WPW could down-regulate the levels of IL-6, IL-1β, and IL-17, and increase the levels of IL-10 and IL-4 in the serum of AA rats. TUNEL staining confirmed that WPW could significantly promote the apoptosis of synovial cells. Moreover, the immunohistochemical results showed that WPW decreased the expression of PI3K, AKT, MAPK, MMP1, MMP3, CDK1, and Bcl-2, as well as increased the expression of Bax protein. In conclusion, we successfully combined GC-MS, UPLC-Q-TOF/MS, network analysis, and experimental validation strategies to elucidate the inhibition of inflammation by WPW in AA model rats via PI3K/AKT, MAPK, cell cycle and apoptotic pathways process. This not only provides new evidence for the study of potential pharmacodynamic substances and the mechanism of WPW in the treatment of RA, but also provides ideas for the study of other Tibetan medicine compound preparations.

Sesquiterpene Lactones and Cancer: New Insight into Antitumor and Anti-inflammatory Effects of Parthenolide-Derived Dimethylaminomicheliolide and Micheliolide

Applied science nowadays works on the isolation and application of biological macromolecules (BMM). These BMM are isolates from plants using different techniques and used as anticancer, antimicrobial, and anti-inflammatory drugs. Parthenolide (PLT) is one of the most important biological macromolecules and a naturally occurring sesquiterpene lactone that is isolated from a plant species Tanacetum parthenium (T. parthenium). The anti-cancer and anti-inflammatory effects of PTL isolated from T. parthenium were previously reported and summarized in detail. These biological activities make it a vital candidate for further researches and drugs development. As per the previously obtained findings, the sesquiterpene is very much known for some biological activities; therefore, the anti-cancer and anti-inflammatory activities of the sesquiterpene were critically reviewed. During the research process, PTL was found to be unstable in both acidic and basic conditions with low solubility, so structurally related compounds micheliolide (MCL) and Dimethylaminomicheliolide (DMAMCL) (a prodrug of MCL) were developed. In this article, we briefly review the therapeutic effects of PTL and its derivative DMAPT on inflammatory diseases and tumors, focusing on the current application of PTL in targeted therapy and combination therapy, together with anti-inflammatory and anti-tumor functions of MCL and DMAMCL. The uniqueness of this biological macromolecule is not to harm the normal cell but target the cancerous cells. Therefore, the current literature review might be helpful and useful for prospects based on the effects of MCL and DMAMCL on cancer.

Immunomodulatory Effect of Hispolon on LPS-Induced RAW264.7 Cells and Mitogen/Alloantigen-Stimulated Spleen Lymphocytes of Mice

Hispolon is a potent anticancer, anti-inflammatory, antioxidant, and antidiabetic agent isolated from Phellinus linteus, an oriental medicinal mushroom. However, the immunomodulatory mechanisms by which hispolon affects macrophages and lymphocytes remain poorly characterized. We investigated the immunomodulatory effects of hispolon on oxidative stress, inflammatory responses, and lymphocyte proliferation using lipopolysaccharide (LPS)-treated RAW264.7 macrophages or mitogen/alloantigen-treated mouse splenocytes. Hispolon inhibited LPS-induced reactive oxygen and nitrogen species (ROS/RNS) generation and decreased total sulfhydryl (SH) levels in a cell-free system and RAW264.7 cells. Hispolon exerted significant anti-inflammatory effects by inhibiting production of the proinflammatory cytokines interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-α) and activation of nuclear factor kappa B (NF-κB) and signal transducer and activator of transcription 3 (STAT3) in LPS-treated RAW264.7 cells. Hispolon also modulated NF-κB and STAT3 activation by suppressing the NF-κB p65 interaction with phospho-IκBα and the STAT3 interaction with JAK1, as determined via coimmunoprecipitation analysis. Additionally, hispolon significantly decreased lymphocyte proliferation, T cell responses and T helper type 1 (Th1)/type 2 (Th2) cytokines production in mitogen/alloantigen-treated splenocytes. We conclude that hispolon exerts immunomodulatory effects on LPS-treated macrophages or mitogen/alloantigen-treated splenocytes through antioxidant, anti-inflammatory, and antiproliferative activities. Thus, hispolon may be a therapeutic agent for treating immune-mediated inflammatory diseases.