[Rheumatoid arthritis]

A systematic review: Sinomenine

Sinomenine (SIN), an alkaloid derived from the traditional Chinese medicine, Caulis Sinomenii, has been used as an anti-inflammatory drug in China for over 30 years. With the continuous increase in research on the pharmacological mechanism of SIN, it has been found that, in addition to the typical rheumatoid arthritis (RA) treatment, SIN can be used as a potentially effective therapeutic drug for anti-tumour, anti-renal, and anti-nervous system diseases. By reviewing a large amount of literature and conducting a summary analysis of the literature pertaining to the pharmacological mechanism of SIN, we completed a review that focused on SIN, found that the current research is insufficient, and offered an outlook for future SIN development. We hope that this review will increase the public understanding of the pharmacological mechanisms of SIN, discover SIN research trial shortcomings, and promote the effective treatment of immune diseases, inflammation, and other related diseases.

Tripterygium hypoglaucum extract ameliorates adjuvant-induced arthritis in mice through the gut microbiota

Traditionally, Tripterygium hypoglaucum (Levl.) Hutch (THH) are widely used in Chinese folk to treat rheumatoid arthritis (RA). This study aimed to investigate whether the anti-RA effect of THH is related with the gut microbiota. The main components of prepared THH extract were identified by HPLC-MS. C57BL/6 mice with adjuvant-induced arthritis (AIA) were treated with THH extract by gavage for one month. THH extract significantly alleviated swollen ankle, joint cavity exudation, and articular cartilage destruction in AIA mice. The mRNA and protein levels of inflammatory mediators in muscles and plasma indicated that THH extract attenuated inflammatory responses in the joint by blocking TLR4/MyD88/MAPK signaling pathways. THH extract remarkably restored the dysbiosis of the gut microbiota in AIA mice, featuring the increases of Bifidobacterium, Akkermansia, and Lactobacillus and the decreases of Butyricimonas, Parabacteroides, and Anaeroplasma. Furthermore, the altered bacteria were closely correlated with physiological indices and drove metabolic changes of the intestinal microbiota. In addition, antibiotic-induced pseudo germ-free mice were employed to verify the role of the intestinal flora. Strikingly, THH treatment failed to ameliorate the arthritis symptoms and signaling pathways in pseudo germ-free mice, which validates the indispensable role of the intestinal flora. For the first time, we demonstrated that THH extract protects joint inflammation by manipulating the intestinal flora and regulating the TLR4/MyD88/MAPK signaling pathway. Therefore, THH extract may serve as a microbial modulator to recover RA in clincial practice.ver RA in clincial practice.

Analyzation of the Peripheral Blood Mononuclear Cells Atlas and Cell Communication of Rheumatoid Arthritis Patients Based on Single-Cell RNA-Seq

Background

Rheumatoid arthritis (RA) is a common chronic inflammatory autoimmune disease with a multifactorial etiology. Peripheral blood is the main channel of the immune system, and peripheral blood mononuclear cells (PBMCs) are the immune cells that initiate the autoimmune inflammatory process. However, there are few reports on the mechanisms of peripheral blood immunity in RA.

Methods

ScRNA-seq was performed on four RA samples and integrated with single-cell transcriptome data from four healthy control samples downloaded from publicly available databases for analysis.

Results

A total of 52,073 cells were used for descending clustering analysis to map RA peripheral blood immune cells at single-cell resolution. Redimensional clustering analysis of four major immune cells (T cells, monocytes, B cells, and natural killer cells) revealed that double-negative T (DNT) cells were significantly altered in abundance and function. And a number of genes (including SOCS3, cAMP-responsive element modulator (CREM), B2M, MTFP1, RSRP1, and YWHAB) were specifically downregulated in DNT cells. RA T cells, especially DNT cells, exhibit significant metabolic defects and dysfunction, mainly in the form of inhibition of oxidative phosphorylation, ATP synthesis, and major histocompatibility complex (MHC)-I-mediated antigen presentation. In addition, cellular communication networks were established, and it was evident that RA is significantly attenuated in the number and intensity of cellular communication. Monocytes and T cells play key roles in the process of the immune inflammatory response through CCL and MHC-related pathways.

Conclusions

This study describes the landscape of the peripheral blood immune system and cell communication in RA, characterizes the abundance of PBMCs, gene expression profiles, and changes in signaling pathways in RA patients, and identifies several key cell subpopulations (DNT and classic monocytes) and specific genes (SOCS3, CREM, B2M, MTFP1, RSRP1, and YWHAB). Meanwhile, we propose that classic monocytes in peripheral blood may migrate to sites of inflammation in synovial tissue under the chemotaxis of the chemokines CCL3 and CCL3L1, differentiate into macrophages, secrete proinflammatory cytokines, and thus participate in the inflammatory response. These findings provide new insights for the future elucidation of the peripheral blood immune mechanisms of RA and the search for new clinical therapeutic targets.

Understanding the function of the GABAergic system and its potential role in rheumatoid arthritis

Rheumatoid arthritis (RA) is a highly disabling chronic autoimmune disease. Multiple factors contribute to the complex pathological process of RA, in which an abnormal autoimmune response, high survival of inflammatory cells, and excessive release of inflammatory factors lead to a severe chronic inflammatory response. Clinical management of RA remains limited; therefore, exploring and discovering new mechanisms of action could enhance clinical benefits for patients with RA. Important bidirectional communication occurs between the brain and immune system in inflammatory diseases such as RA, and circulating immune complexes can cause neuroinflammatory responses in the brain. The gamma-aminobutyric acid (GABA)ergic system is a part of the nervous system that primarily comprises GABA, GABA-related receptors, and GABA transporter (GAT) systems. GABA is an inhibitory neurotransmitter that binds to GABA receptors in the presence of GATs to exert a variety of pathophysiological regulatory effects, with its predominant role being neural signaling. Nonetheless, the GABAergic system may also have immunomodulatory effects. GABA/GABA-A receptors may inhibit the progression of inflammation in RA and GATs may promote inflammation. GABA-B receptors may also act as susceptibility genes for RA, regulating the inflammatory response of RA via immune cells. Furthermore, the GABAergic system may modulate the abnormal pain response in RA patients. We also summarized the latest clinical applications of the GABAergic system and provided an outlook on its clinical application in RA. However, direct studies on the GABAergic system and RA are still lacking; therefore, we hope to provide potential therapeutic options and a theoretical basis for RA treatment by summarizing any potential associations.

Dual-Drug Loaded Separable Microneedles for Efficient Rheumatoid Arthritis Therapy

Although the inhibitors of the interleukin-6 receptor (IL-6R) and tumor necrosis factor-α (TNF-α) have achieved a certain success in the clinical treatment of rheumatoid arthritis (RA), great effort should be made to overcome side effects and to improve patient compliance. The present research aimed to address these problems by the co-delivery of tocilizumab (TCZ)—an inhibitor of IL-6R—and an aptamer Apt1-67, which specifically inhibits TNF receptor 1 via separable microneedles (MN). MN were featured with a sustained release of TCZ from needle tips and a rapid release of Apt1-67 from needle bodies by using methacrylate groups grafted hyaluronic acid as the fillings of needle tips and polyvinyl alcohol/polyvinyl pyrrolidone as the fillings of needle bodies. Our results demonstrated that TCZ and Apt1-67 were distributed in MN as expected, and they could be released to the surroundings in the skin. In vivo studies revealed that combined medication via MN (TCZ/Apt1-67@MN) was superior to MN loaded with a single drug. Compared with subcutaneous injection, TCZ/Apt1-67@MN was of great advantage in inhibiting bone erosion and alleviating symptoms of CIA mice. This study not only provides a novel approach for combined medication with different release properties but also supplies a strategy for improving drug efficacy.

Linc02381 Exacerbates Rheumatoid Arthritis Through Adsorbing miR-590-5p and Activating the Mitogen-Activated Protein Kinase Signaling Pathway in Rheumatoid arthritis-fibroblast-like synoviocytes

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease. New evidence suggested that linc02381 suppressed colorectal cancer progression by regulating PI3 K signaling pathway, but the role of linc02381 in other diseases, such as RA, remains unclear. This study aimed to reveal the mechanism of linc02381 in RA progression. In vivo and in vitro, we found that linc02381 was upregulated in RA synovial tissues or RA fibroblast-like synoviocytes (RA-FLSs, P < 0.01), which were detected by quantitative real-time polymerase chain reaction. Cell Counting Kit-8, EDU, and Transwell assays revealed that linc02381 overexpression enhanced cell proliferation and invasion, and linc02381 knockdown inhibited cell proliferation and invasion in FLSs. Moreover, the results of bioinformatics analysis, luciferase reporter gene assay, and pull-down assay verified that linc02381 could directly bind with miR-590-5p. MiR-590-5p was downregulated in RA-FLSs, and overexpression of linc02381 suppressed expression of miR-590-5p that post-transcriptionally suppressed the expression of mitogen-activated protein kinase kinase 3 (MAP2K3), and overexpression of miR-590-5p reversed the effect of linc02381 overexpression on MAP2K3 expression. MiR-590-5p inhibitor reversed the inhibition effect of linc02381 knockdown on proliferation and invasion of FLSs, which enhanced expression of MAP2K3, and activation of p38 and AP-1 in the MAPK signaling pathway. In summary, linc02381 was upregulated in RA synovial tissues and RA-FLSs, and it exacerbated RA by adsorbing miR-590-5p to activate the MAPK signaling pathway.

IL-38 restrains inflammatory response of collagen-induced arthritis in rats via SIRT1/HIF-1α signaling pathway

OBJECTIVE

To observe the restraining effect of IL-38 on inflammatory response in collagen-induced arthritis rats (CIA), and to explore the regulatory mechanism of SIRT1/HIF-1α signaling pathway.

METHODS

40 SD rats were randomly divided into Control group, CIA group, CLL group and CLH group, with 10 rats in each group; CIA rat model was established. The effects of IL-38 on arthritis index, inflammatory response, osteogenic factor and angiogenic factor were observed by methods including HE staining, ELISA, immunohistochemical and immunofluorescence. Human synoviocytes were cultured in vitro, and SIRT1 inhibitors were added to detect the expression for relating factors of SIRT1/HIF-1α signaling pathway by Western blot.

RESULTS

IL-38 could alleviate CIA joint damage and restrain inflammatory response, could up-regulate the expression of OPG in CIA rats and could down-regulate the expression of RANKL and RANK. IL-38 could restrain the expression of VEGF, VEGFR1, VEGFR2 and HIF. Moreover, we found that IL-38 could up-regulate the SIRT1 expression and down-regulate the HIF-1α, TLR4 and NF-KB p65 expression in CLL and CLH groups. From the treatment of synoviocytes to simulate the CIA model and the treatment of SIRT1 inhibitors, we demonstrated that the inhibitory effect of IL-38 on inflammatory factors and regulation of SIRT1/HIF-1α signaling pathway-related proteins were inhibited.

CONCLUSION

IL-38 can restrain the inflammatory response of CIA rats, can promote the expression of osteogenic factors, can inhibit neovascularization, and can alleviate joint damage in rats. The mechanism may be related to the regulation of SIRT1/HIF-1α signaling pathway.

A cross-sectional study of association of serostatus and extra-articular manifestations in patients with rheumatoid arthritis in a teaching hospital

BACKGROUND

Rheumatoid arthritis (RA) is an autoimmune disease, which mistakenly attacks the joints and induces the inflammatory changes that thicken the joints (the synovium) resulting in swelling and pain in and around the joints. It causes pain, joint deformity, and also affects the quality of life. The joint is affected symmetrically. It also can affect body systems, such as the cardiovascular, respiratory systems, or other systems, which manifest as extra-articular manifestations. Extra-articular manifestations of RA are documented less in India hence this study was undertaken to correlate RA with extra-articular manifestations as well as its relationship with serostatus in patients with extra-articular manifestations.

MATERIALS AND METHODS

Sixty patients (age between 18-60 years) attending Medicine/Rheumatology outpatient department were included in the study (12 months) who fulfilled the 2010 RA classification criteria laid down by American College of Rheumatology (ACR)/European League against Rheumatism (EULAR) for RA. All the subjects underwent a thorough history, clinical examination, and laboratory investigations. The relevant data were analyzed with appropriate statistical methods after 12 months' duration.

RESULTS

Nearly 68.33% of the subjects were found to have extra-articular manifestations mostly in the age group of 31-40 years with prevalence higher in the female. In the seropositive patients, early morning stiffness (EMS) constitutes 63.82% of the total extra-articular manifestations in the patients followed by anemia (38.29%) and peripheral neuropathy (34.04%). On the other hand, in the seronegative cases, EMS (61.53%) followed by anemia (23.07), peripheral neuropathy (15.38%), and keratoconjunctivitis sicca (15.38%). Extra-articular manifestations in seropositive patients have a statistically significant relationship with the increase in the duration of the disease.

CONCLUSION

Extra-articular manifestations need to be looked carefully as it is associated with more severe disease. Seropositivity and extra-articular manifestations both usually indicate that the RA is more severe and may affect the quality of life.

A drug-drug interaction study to evaluate the impact of peficitinib on OCT1- and MATE1-mediated transport of metformin in healthy volunteers

Purpose

Peficitinib is an oral pan-Janus kinase inhibitor for the treatment of rheumatoid arthritis. Co-administration of peficitinib with metformin, a type 2 diabetes therapy, can occur in clinical practice. Hepatic and renal uptake of metformin is mediated by organic cation transporter 1 (OCT1) and OCT2, respectively, and its renal excretion by multidrug and toxin extrusion 1 (MATE1) and MATE2-K. This study investigated the effect of peficitinib on metformin pharmacokinetics in vitro and in healthy volunteers.

Methods

Inhibitory effects of peficitinib and its metabolite H2 on metformin uptake into human OCT1/2- and MATE1/2-K-expressing cells were assessed in vitro. In an open-label, drug–drug interaction study, 24 healthy volunteers received a single dose of metformin 750 mg on Days 1 and 10, and a single dose of peficitinib 150 mg on Days 3 and 5–11. Blood and urine samples were collected pre-dose on Days 1 and 10, and at intervals ≤ 48 h post-dose. Metformin concentration was determined by liquid chromatography–tandem mass spectrometry and its pharmacokinetic parameters calculated.

Results

Peficitinib, but not H2, inhibited metformin uptake into OCT1- and MATE1/2-K-expressing cells. Repeated-dose administration of peficitinib reduced metformin area under the concentration–time curve from 0 h extrapolated to infinity (AUC_inf) by 17.4%, maximum plasma concentration (C_max) by 17.0%, and renal clearance (CL_R) by 12.9%. Co-administration of peficitinib with metformin was generally well tolerated.

Conclusion

Slight changes in AUC_inf, C_max and CL_R of metformin were observed when co-administered with peficitinib; however, these changes were considered not clinically relevant.

Electronic supplementary material

The online version of this article (10.1007/s00228-020-02876-2) contains supplementary material, which is available to authorized users.

Total knee arthroplasty for treatment of rheumatoid arthritis: A protocol for a systematic review of randomized controlled trial

BACKGROUND

Rheumatoid arthritis (RA) is a very tricky orthopedic condition. If it can not be treated fairly well, it may greatly affect quality of life in patients with RA, and even can cause disability. Total knee arthroplasty (TKA) has reported to treat patients with RA effectively. However, no study has systematically explored its efficacy and complications for patients with RA.

METHODS

Seven databases will be searched from their inceptions to the present without any language restrictions: MEDICINE, EMBASE, Cochrane Library, Web of Science, Allied and Complementary Medicine Database, Chinese Biomedical Literature Database, and China National Knowledge Infrastructure. Two authors will carry out all study selection, data extraction, and risk of bias assessment independently.

RESULTS

The primary outcome of joint pain will be measured by any pain scales, such as visual analogue scale. The secondary outcomes will include joint function, quality of life, and postoperative adverse events. The joint function will be measured by The Western Ontario and McMaster Universities Arthritis Index, Knee Injury and Osteoarthritis Outcome Score, or other relevant scales. The quality of life will be assessed by the 36-Item Short Form Health Survey or any related tools. In addition, postoperative adverse events will also be analyzed.

CONCLUSIONS

The findings of this study will summarize the latest existing evidence on the efficacy and safety of TKA for patients with RA.

ETHICS AND DISSEMINATION

This study does not need ethical approval, because it will not analyze individual data. The results of this study are expected to be disseminated at peer-reviewed journals.

PROSPERO REGISTRATION NUMBER

PROSPERO CRD42019133274.

PRL -1149T allele (rs1341239) is associated with decreased risk of rheumatoid arthritis in population from southern Mexico: analysis of mRNA expression and PRL serum levels

INTRODUCTION

Prolactin (PRL) is a sex hormone with immunomodulatory properties, and it is associated with the clinical activity of rheumatoid arthritis (RA). The -1149G>T polymorphism at the prolactin (PRL) gene has been associated with autoimmune diseases, but its functional effect is unclear.

OBJECTIVE

To analyze the association of the PRL -1149G>T polymorphism with disease susceptibility, mRNA, and protein expression of PRL in RA patients from Southern Mexico.

METHODS

We included 300 RA patients and 300 control subjects (CS). Genotypes were identified by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique, the PRL mRNA expression was determined by real-time PCR, and PRL serum levels were measured by enzyme-linked immunosorbent assay.

RESULTS

Applying genetic models of inheritance (dominant, recessive, and additive), we found an association between the T allele and decreased RA susceptibility (OR = 0.55, 95% CI 0.35-0.87, p = 0.009; OR = 0.09, 95% CI 0.012-0.76, p = 0.011; OR = 0.49, 95% CI 0.32-0.76, p = 0.001, respectively). RA patients had higher mRNA expression and soluble levels of PRL than CS (p < 0.05). The PRL serum levels were similar in RA and CS according to genotypes. However, in CS, carriers of GT and TT genotypes showed lower PRL mRNA expression than GG genotype carriers (7.1-fold and 20-fold respectively, p = 0.006).

CONCLUSIONS

This study demonstrated that the PRL -1149T allele is a genetic marker of decrease risk to RA in population from Southern Mexico, and it is associated with low PRL mRNA.

KEY POINTS

• PRL -1149T allele is a marker of decreased RA susceptibility in population from southern Mexico. • PRL -1149TT genotype is associated with low PRL mRNA expression. • RA patients have higher mRNA expression and soluble levels of PRL than healthy subjects. • PRL serum levels are higher in those RA patients with < 2 years of disease evolution.