Effect of Er Miao San on peritoneal macrophage polarisation through the miRNA-33/NLRP3 signalling pathway in a rat model of adjuvant arthritis

NLRP3 inflammasome and its role in autoimmune diseases: A promising therapeutic target

The NOD-like receptor protein 3 (NLRP3) inflammasome is a protein complex that regulates innate immune responses by activating caspase-1 and the inflammatory cytokines IL-1β and IL-18. Numerous studies have highlighted its crucial role in the pathogenesis and development of inflammatory bowel disease, rheumatoid arthritis, systemic lupus erythematosus, autoimmune thyroid diseases, and other autoimmune diseases. Therefore, investigating the underlying mechanisms of NLRP3 in disease and targeted drug therapies holds clinical significance. This review summarizes the structure, assembly, and activation mechanisms of the NLRP3 inflammasome, focusing on its role and involvement in various autoimmune diseases. This review also identifies studies where the involvement of the NLRP3 inflammasome in the disease mechanism within the same disease appears contradictory, as well as differences in NLRP3-related gene polymorphisms among different ethnic groups. Additionally, the latest therapeutic advances in targeting the NLRP3 inflammasome for autoimmune diseases are outlined, and novel clinical perspectives are discussed. Conclusively, this review provides a consolidated source of information on the NLRP3 inflammasome and may guide future research efforts that have the potential to positively impact patient outcomes.

Evaluating the docetaxel effect in an animal model of polyarthritis

Rheumatoid arthritis (RA) is immune-mediated, inflammatory disease that affects synovial joints, and characterized by inflammatory changes in synovial tissue, cartilage, bone, and less commonly in extra-articular structures. Docetaxel (DTX) is a semi-synthetic anti-neoplastic medication. Peptidyl-arginine deiminase type 4 (PAD4) is expressed in macrophages and neutrophils in RA synovial membrane. Their effectiveness is in producing anti-cyclic citrullinated peptide antibodies (ACPA)-targeted citrullinated neoepitopes.

AIM

To evaluate the anti-inflammatory effects of DTX in RA and the effect of methotrexate on PAD4 to investigate its potential as an RA biomarker.

METHODS

Forty male Wistar rats were divided into five groups of eight rats. Healthy rats formed the control group. The Second Group to Fifth group were induced with Complete Freund's adjuvant. The third group received DTX at a dosage of 1 mg/kg on alternate days, as determined by a preliminary experiment. The fourth group was given 1 mg/kg/week of methotrexate intraperitoneally. The fifth group was treated with a half dose of DTX and methotrexate simultaneously.

RESULTS

Significant Arthritis index and knee joint circumference decrease in the DTX group. No significant difference in body weight, platelet-lymphocyte ratio, and white blood cell count between the groups. Neutrophile lymphocyte ratio showed weak correlation with ACPA, while PAD4 showed good correlation with RA markers. Level of ACPA, PAD4, TNF-α, IL-1β, and VEGF significantly decreased in the DTX group than induction group (p < 0.05).

CONCLUSION

DTX reduces the progression and joint destruction in rats induced by Complete Freund's Adjuvant which may due to inhibition of PAD4, TNF-α, IL-1β, VEGF, and ACPA. Also, methotrexate exhibited anti PAD4 effect.

Implication of M2 macrophage on NLRP3 inflammasome signaling in mediating the neuroprotective effect of Canagliflozin against methotrexate-induced cognitive impairment

Methotrexate (MTX), a chemotherapeutic antimetabolite, has been linked to cognitive impairment in cancer patients. MTX-induced metabolic pathway disruption may result in decreased antioxidant activity and increased oxidative stress, influencing hippocampal neurogenesis and microglial activation. Nuclear factor-kappa B (NF-κB), an oxidative stress byproduct, has been linked to MTX toxicity via the activation of NLRP3 inflammasome signaling. Macrophage activation and polarization plays an important role in tissue injury. This differentiation may be mediated via either the Toll-like receptor 4 (TLR4) or NLRP3 inflammasome. Interestingly, Canagliflozin (CANA), a sodium-glucose cotransporter 2 (SGLT2) inhibitor has been recently reported to exert anti-inflammatory effects by modulating macrophage polarization balance. This study aimed to investigate CANA's protective effect against MTX-induced cognitive impairment, highlighting the possible involvement of TLR4/ NF-κB crosstalk with NLRP3 inflammasome activation and macrophage polarization. Forty-eight Male Wistar rats were divided into 4 groups; (1) received saline orally for 30 days and intravenously on days 8 and 15. (2) received Canagliflozin (CANA; 20 mg/kg/day; p.o.) for 30 days. (3) received MTX (75 mg/kg, i.v.) on day 8 and 15, then they were injected with four i.p. injections of leucovorin (LCV): the first dose was 6 mg/ kg after 18 h, and the remaining doses were 3 mg/kg after 26, 42, and 50 h of MTX administration. (4) received MTX and LCV as in group 3 in addition to CANA as in group 2. MTX-treated rats showed cognitive deficits in spatial and learning memory as evidenced in the novel object recognition and Morris water maze tests. MTX exerted an oxidative effect which was evident by the increase in MDA and decline in SOD, GSH and GPx. Moreover, it exerted an inflammatory effect via elevated caspase-1, IL-1β and IL-8. CANA treatment restored cognitive ability, reduced MTX-induced oxidative stress and neuroinflammation via attenuation of TLR4/NF-κB/NLRP3 signaling, and rebalanced macrophage polarization by promoting the M2 phenotype. Hence, targeting molecular mechanisms manipulating macrophage polarization may offer novel neuroprotective strategies for preventing or treating MTX-induced immune modulation and its detrimental sequel.

Mechanisms of NLRP3 inflammasome in rheumatoid arthritis and osteoarthritis and the effects of traditional Chinese medicine

ETHNOPHARMACOLOGICAL RELEVANCE

It has been widely reported that various anti-rheumatic traditional Chinese medicines (TCMs) ameliorate rheumatoid arthritis (RA) and osteoarthritis (OA) through regulating the abnormal production, assembly, and activation of the NOD-like receptor thermal protein domain-associated protein 3 (NLRP3) inflammasome. These TCMs include monomers isolated from Chinese herbs, extracts of Chinese herbs, and Chinese medical formulae with a lengthy application history.

AIM OF THE STUDY

This review aimed to summarize and analyze the published articles about the NLRP3 inflammasome and its role in the pathogenesis of RA and OA. We also reviewed existing knowledge on the therapeutic mechanism of TCMs in RA and OA via the regulation of the NLRP3 inflammasome.

MATERIALS AND METHODS

We searched for relevant articles with the keywords "NLRP3 inflammasome", "traditional Chinese medicine," "Chinese herbal drugs," "rheumatoid arthritis," and "osteoarthritis." The information retrieval was conducted in medical Chinese and English databases from the date of construction to April 19, 2023, including PubMed, MEDLINE, Web of Science, Scopus, Ovid, China National Knowledge Infrastructure (CNKI), Chinese Biomedicine Literature Database (CBM), Chinese Science and Technology Periodicals Database (VIP), and China Online Journals (COJ).

RESULTS

According to retrieval results, 35 TCMs have been demonstrated to relieve RA by targeting the NLRP3 inflammasome, including six traditional Chinese prescriptions, seven extracts of Chinese herbs, and 22 monomers extracted from traditional Chinese herbs and formulae. Additionally, 23 TCMs have shown anti-OA effects with abilities to modulate the NLRP3 inflammasome, including five traditional Chinese prescriptions, one extract of Chinese herbs, and 17 monomers from Chinese herbs.

CONCLUSIONS

We summarized mechanism research about the pivotal roles of the NLRP3 inflammasome in the pathogenesis of RA and OA. Moreover, a review of TCMs with targets of the NLRP3 inflammasome in RA and OA treatment was also conducted. Our work is conducive to a better application of TCMs in complementary and alternative therapies in RA and OA.

Wnt/β-catenin signaling pathway promotes abnormal activation of fibroblast-like synoviocytes and angiogenesis in rheumatoid arthritis and the intervention of Er Miao San

BACKGROUND

Er Miao San (EMS) is an important herbal formula and a representative prescription for the treatment of the downwards flow of damp-heat syndrome. Clinical practice has proven that EMS can effectively treat rheumatoid arthritis (RA). Previous studies have demonstrated that EMS regulates the functions of T cells and dendritic cells and affects the polarization of macrophages. However, it is not clear whether the inhibitory effect of EMS on RA is related to the regulation of abnormal synovial activation and angiogenesis.

PURPOSE

The aim of this study was to elucidate the effect and potential mechanisms of EMS on the abnormal activation and angiogenesis of fibroblast-like synoviocytes (FLSs) in RA.

METHODS

The effect of EMS on rats with adjuvant arthritis (AA) and MH7A cells was examined by X-ray, haematoxylin-eosin (HE) staining, immunohistochemistry (IHC), ELISA and western blotting. Angiogenesis in AA rats was measured by a small animal ultrasound imaging system, immunofluorescence (IF) analysis and ELISA. An exchange between MH7A cells and HUVECs was induced using conditioned media that mimicked the microenvironment in vivo. CCK-8, western blotting, and scratch healing and Transwell migration assays were used to evaluate the effect of EMS on the Wnt/β-catenin signaling pathway and angiogenesis in the inflammatory microenvironment of RA.

RESULTS

Our results showed that EMS had a protective effect on AA rats. On the one hand, there was a decrease in paw swelling, the arthritis index, organ indices and proinflammatory factor levels, as well as relief of joint damage. On the other hand, blood flow, the number of immature blood vessels and proangiogenic factors were decreased. Furthermore, EMS reduced the expression of the Wnt/β-catenin signaling pathway in the synovial tissue of AA rats and MH7A cells. In the inflammatory microenvonrment of RA, the results were consistent.

CONCLUSION

This study demonstrated that EMS could protect against RA by inhibiting the abnormal activation and angiogenesis of FLSs, and the mechanism may be related to inhibiting the activation of the Wnt/β-catenin signaling pathway.

New Potentiality of Bioactive Substances: Regulating the NLRP3 Inflammasome in Autoimmune Diseases

The NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome is an essential component of the human innate immune system, and is closely associated with adaptive immunity. In most cases, the activation of the NLRP3 inflammasome requires priming and activating, which are influenced by various ion flux signals and regulated by various enzymes. Aberrant functions of intracellular NLRP3 inflammasomes promote the occurrence and development of autoimmune diseases, with the majority of studies currently focused on rheumatoid arthritis, systemic lupus erythematosus and systemic sclerosis. In recent years, a number of bioactive substances have shown new potentiality for regulating the NLRP3 inflammasome in autoimmune diseases. This review provides a concise overview of the composition, functions, and regulation of the NLRP3 inflammasome. Additionally, we focus on the newly discovered bioactive substances for regulating the NLRP3 inflammasome in autoimmune diseases in the past three years.

Global scientific trends update on macrophage polarization in rheumatoid arthritis: A bibliometric and visualized analysis from 2000 to 2022

The goal of this work was to use bibliometric analysis to help guide future research on macrophage polarization in RA. We looked for studies on macrophage polarization in RA published between January 1, 2000, and December 31, 2022, in the WoSCC database. Research trends and hotspots were shown and assessed using VOSviewer and CiteSpace. A total of 181 articles were gathered. Belgium was among the early adopters of the field. Chinese institutes have produced the most research. Researchers such as Angel Luis Corb, Amaya Puig-Kröger, and Lizbeth Estrada-Capetillo have made major contributions to the field. Frontiers in Immunology has published the most study findings. According to VOSviewer, the most investigated immune cells, biomarkers, and signaling pathways in the previous three years have been "T cells", "gm-csf", and "nf-κb" in that order. We discovered that the most often used terms in the previous three years were "pathway", "oxidative stress", "extracellular capsule" and "nlrp3 inflammasome" using Citespace. We emphasize these concepts in our findings, presenting the exact mechanisms of pathophysiology related to macrophage polarization in RA, as well as current breakthroughs in therapy strategies.

Prevention and treatment of inflammatory arthritis with traditional Chinese medicine: Underlying mechanisms based on cell and molecular targets

Inflammatory arthritis, primarily including rheumatoid arthritis, osteoarthritis and ankylosing spondylitis, is a group of chronic inflammatory diseases, whose general feature is joint dysfunction with chronic pain and eventually causes disability in older people. To date, both Western medicine and traditional Chinese medicine (TCM) have developed a variety of therapeutic methods for inflammatory arthritis and achieved excellent results. But there is still a long way to totally cure these diseases. TCM has been used to treat various joint diseases for thousands of years in Asia. In this review, we summarize clinical efficacies of TCM in inflammatory arthritis treatment after reviewing the results demonstrated in meta-analyses, systematic reviews, and clinical trials. We pioneered taking inflammatory arthritis-related cell targets of TCM as the entry point and further elaborated the molecular targets inside the cells of TCM, especially the signaling pathways. In addition, we also briefly discussed the relationship between gut microbiota and TCM and described the role of drug delivery systems for using TCM more accurately and safely. We provide updated and comprehensive insights into the clinical application of TCM for inflammatory arthritis treatment. We hope this review can guide and inspire researchers to further explore mechanisms of the anti-arthritis activity of TCM and make a great leap forward in comprehending the science of TCM.

Advancements in understanding the role of microRnas in regulating macrophage polarization during acute lung injury

Acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) is a critical and life-threatening illness that causes severe dyspnea, and respiratory distress and is often caused by a variety of direct or indirect factors that damage the alveolar epithelium and capillary endothelial cells, leading to inflammation factors and macrophage infiltration. Macrophages play a crucial role in the progression of ALI/ARDS, exhibiting different polarized forms at different stages of the disease that control the disease outcome. MicroRNAs (miRNA) are conserved, endogenous, short non-coding RNAs composed of 18-25 nucleotides that serve as potential markers for many diseases and are involved in various biological processes, including cell proliferation, apoptosis, and differentiation. In this review, we provide a brief overview of miRNA expression in ALI/ARDS and summarize recent research on the mechanism and pathways by which miRNAs respond to macrophage polarization, inflammation, and apoptosis. The characteristics of each pathway are also summarized to provide a comprehensive understanding of the role of miRNAs in regulating macrophage polarization during ALI/ARDS.

Update on transfusion-related acute lung injury: an overview of its pathogenesis and management

Transfusion-related acute lung injury (TRALI) is a severe adverse event and a leading cause of transfusion-associated death. Its poor associated prognosis is due, in large part, to the current dearth of effective therapeutic strategies. Hence, an urgent need exists for effective management strategies for the prevention and treatment of associated lung edema. Recently, various preclinical and clinical studies have advanced the current knowledge regarding TRALI pathogenesis. In fact, the application of this knowledge to patient management has successfully decreased TRALI-associated morbidity. This article reviews the most relevant data and recent progress related to TRALI pathogenesis. Based on the existing two-hit theory, a novel three-step pathogenesis model composed of a priming step, pulmonary reaction, and effector phase is postulated to explain the process of TRALI. TRALI pathogenesis stage-specific management strategies based on clinical studies and preclinical models are summarized with an explication of their models of prevention and experimental drugs. The primary aim of this review is to provide useful insights regarding the underlying pathogenesis of TRALI to inform the development of preventive or therapeutic alternatives.

Exploring the effect of Er miao San-containing serum on macrophage polarization through miR-33/NLRP3 pathway

HEADINGS ETHNOPHARMACOLOGICAL RELEVANCE

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease. Er miao San (EMS) has been shown to have good anti-inflammatory effects and is widely used in the clinical treatment of RA. However, the exact mechanism is not completely understood.

AIM OF THE STUDY

The aim of this study was to explore that EMS-containing serum affects M1/M2 polarization of macrophages and may be mediated through the microRNA (miRNA)-33/NLRP3 pathway, thereby elucidating the molecular mechanism of EMS treatment of RA.

MATERIALS AND METHODS

We screened for safe concentrations of EMS-containing serum by using CCK-8 measurement. RAW264.7 cells were cultured with lipopolysaccharide (LPS) (100 ng/mL) and interferon-γ (20 ng/mL) for 24 h to induce M1-type macrophages. Adenosine triphosphate (ATP) (5 mM) was added in the last 30 min to activate NLRP3. The content of miR-33 was detected by RT‒qPCR after transfection of the miRNA-33 mimic. The protein expression levels of NLRP3, ASC, caspase-1, Inducible Nitric Oxide Synthase (iNOS) and Arginase-1 (Arg-1) were detected by Western blot. The contents of IL-1β, IL-10, TNF-α, TGF-β and IL-18 in serum and cell supernatant were determined by ELISA. The fluorescence intensity of CD86 and CD206 was detected by immunofluorescence.

RESULTS

The results showed that EMS-containing serum promoted the protein expression level of Arg-1 and the secretion levels of TGF-β and IL-10, inhibited the levels of iNOS, IL-1β and TNF-α, and regulated the balance of pro-inflammatory factors and anti-inflammatory factors. RT‒qPCR results showed that EMS-containing serum could reduce the level of miRNA-33. EMS-containing serum could reduce the expression of NLRP3 inflammasome-related proteins and downregulate the expression levels of IL-1β and IL-18. These results suggest that EMS exerts its effect on macrophage polarization through the miRNA-33/NLRP3 pathway.

CONCLUSION

EMS-containing serum inhibits the activation of the NLRP3 inflammasome by downregulating miRNA-33, thus preventing the polarization of M1-type macrophages.