The Role of Biologics in Rheumatoid Arthritis: A Narrative Review

IGF2BP3 regulates the expression of RRM2 and promotes the progression of rheumatoid arthritis via RRM2/Akt/MMP-9 pathway

BACKGROUND

Rheumatoid arthritis (RA) is a common inflammatory and autoimmune disease. Ribonucleotide Reductase Regulatory Subunit M2 (RRM2) is a crucial and a rate-limiting enzyme responsible for deoxynucleotide triphosphate(dNTP) production. We have found a high expression level of RRM2 in patients with RA, but the molecular mechanism of its action remains unclear.

METHODS

We analyzed the expression of hub genes in RA using GSE77298 datasets downloaded from Gene Expression Omnibus database. RRM2 and insulin-like growth factor-2 messenger ribonucleic acid (mRNA)-binding protein 3 (IGF2BP3) gene knockdown was achieved by infection with lentiviruses. The expression of RRM2, IGF2BP3, matrix metalloproteinase (MMP)-1, and MMP-9 were detected via western blotting assay. Cell viability was detected via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. MeRIP-qRT-PCR was performed to test the interaction of IGF2BP3 and RRM2 mRNA via m6A modification. Cell proliferation was determined by clone formation assay. Migration and invasion assays were performed using transwell Boyden chamber.

RESULTS

RRM2 and IGF2BP3 were highly expressed in clinical specimens and tumor necrosis factor alpha (TNF-α) and interleukin (IL)-1β-stimulated synovial cells. RRM2 and IGF2BP3 knockdown inhibited the proliferation, migration, and invasion of MH7A cells. The inhibitory effects of IGF2BP3 knockdown were effectively reversed by simultaneously overexpressing RRM2 in MH7A cells. By analyzing N6-methyladenosine (m6A)2Target database, five m6A regulatory target binding sites for IGF2BP3 were identified in RRM2 mRNA, suggesting a direct relationship between IGF2BP3 and RRM2 mRNA. Additionally, in RRM2 small hairpin (sh)RNA lentivirus-infected cells, the levels of phosphorylated Akt and MMP-9 were significantly decreased compared with control shRNA lentivirus-infected cells.

CONCLUSION

The present study demonstrated that RRM2 promoted the Akt phosphorylation leading to high expression of MMP-9 to promote the migration and invasive capacities of MH7A cells. Overall, IGF2BP promotes the expression of RRM2, and regulates the migration and invasion of MH7A cells via Akt/MMP-9 pathway to promote RA progression.

A Review of the Current Status of Anesthetic Management of Patients with Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic connective tissue disease of immunological etiology. In the course of the disease, symptoms of the musculoskeletal system predominate, but other systems can also be affected. The disease may require long-term treatment, and patients often require surgery on damaged joints. Complications of the disease and drug interactions may contribute to difficulties in perioperative care; therefore, knowledge is required to provide appropriate care. When anesthetizing a patient with RA, we should pay special attention to preoperative evaluation, taking a medical history, risk of difficult intubation or cardiac incidents, respiratory insufficiency, and frequent pulmonary infections. It is important to be aware of perioperative glucocorticoids supplementation, especially in patients with suspected adrenal insufficiency. Postoperative management, such as pain management, early rehabilitation, and restart of pharmacotherapy play, an important role in the patient's recovery. Special attention should be paid to perioperative management in pregnant women, as the disease is a significant risk factor for complications, and some anesthetic procedures can be noxious to the fetus. Due to the nature of the disease, it can be challenging for the anesthesiologist to provide good and appropriate pain medications, symptom management, and other necessary techniques that are done to anesthetize the patient properly. This work is based on the available literature and the authors' experience. This article aims to review the current status of anesthetic management of patients with rheumatoid arthritis.

Cayratia albifolia C.L.Li exerts anti-rheumatoid arthritis effect by inhibiting macrophage activation and neutrophil extracellular traps (NETs)

BACKGROUND

Cayratia albifolia C.L.Li (CAC), commonly known as "Jiao-Mei-Gu" in China, has been extensively utilized by the Dong minority for several millennia to effectively alleviate symptoms associated with autoimmune diseases. CAC extract is believed to possess significant anti-inflammatory properties within the context of Dong medicine. However, an in-depth understanding of the specific pharmaceutical effects and underlying mechanisms through which CAC extract acts against rheumatoid arthritis (RA) has yet to be established.

METHODS

Twenty-four Sprague-Dawley rats were divided into four groups, with six rats in each group. To induce the collagen-induced arthritis (CIA) model, the rats underwent a process of double immunization with collagen and adjuvant. CAC extract (100 mg/kg) was orally administered to rats. The anti-RA effects were evaluated in CIA rats by arthritis score, hind paw volume and histopathology analysis. Pull-down assay was conducted to identify the potential targets of CAC extract from RAW264.7 macrophage lysates. Moreover, mechanism studies of CAC extract were performed by immunofluorescence assays, real-time PCR and Western blot.

RESULTS

CAC extract was found to obviously down-regulate hind paw volume of CIA rats, with diminished inflammation response and damage. 177 targets were identified from CAC extract by MS-based pull-down assay. Bioinformatics analysis found that these targets were mainly enriched in macrophage activation and neutrophils extracellular traps (NETs). Additionally, we reported that CAC extract owned significant anti-inflammatory activity by regulating PI3K-Akt-mTOR signal pathway, and inhibited NETosis in response to PMA.

CONCLUSIONS

We clarified that CAC extract significantly attenuated RA by inactivating macrophage and reducing NETosis via a multi-targets regulation.

Clinical significance of long non-coding RNA NORAD in rheumatoid arthritis

BACKGROUND

Rheumatoid arthritis (RA) is a chronic autoimmune disease that may cause joint deformities and seriously affect the normal life of the patients. In order to enable patients to receive timely attention and treatment, this study developed new diagnostic markers by exploring the expression and molecular mechanism of the long non-coding RNA NORAD (NORAD) in RA.

METHODS

Participants including 77 RA patients and 52 healthy persons were enrolled, and the corresponding clinical data and serum samples were obtained. The NORAD and miR-204-5p expression were detected by real-time fluorescence quantitative polymerase chain reaction (RT-qPCR). The content of inflammatory cytokines (IL-6, TNF-α) were determined through enzyme-linked immunosorbent assay (ELISA). Luciferase activity reporter assay demonstrated the association between NORAD and miR-204-5p. In addition, receiver operating characteristic (ROC) curve was used to evaluate the diagnostic efficacy of NORAD, and Pearson's correlation analysis was applied for the correlation analysis.

RESULTS

NORAD was enriched in RA serum with high diagnostic value. Simultaneously, IL-6 and TNF-α levels were also upregulated (P < 0.001). The C-reactive protein (CRP), rheumatoid factor (RF), erythrocyte sedimentation rate (ESR) and anti-cyclic citrullinated peptide antibody (Anti-CCP) levels in RA patients were generally elevated (P < 0.001). NORAD was positively correlated with the levels of clinical indicators and inflammatory factors (P < 0.0001). Mechanistically, NORAD may affect the progression of RA by targeting and negatively regulating miR-204-5p.

CONCLUSIONS

There is a correlation between NORAD and the processes of RA, and NORAD has the potential to predict and diagnose the occurrence of RA.

A Review of Proposed Mechanisms in Rheumatoid Arthritis and Therapeutic Strategies for the Disease

Rheumatoid arthritis (RA) is characterized by synovial edema, inflammation, bone and cartilage loss, and joint degradation. Patients experience swelling, stiffness, pain, limited joint movement, and decreased mobility as the condition worsens. RA treatment regimens often come with various side effects, including an increased risk of developing cancer and organ failure, potentially leading to mortality. However, researchers have proposed mechanistic hypotheses to explain the underlying causes of synovitis and joint damage in RA patients. This review article focuses on the role of synoviocytes and synoviocytes resembling fibroblasts in the RA synovium. Additionally, it explores the involvement of epigenetic regulatory systems, such as microRNA pathways, silent information regulator 1 (SIRT1), Peroxisome proliferatoractivated receptor-gamma coactivator (PGC1-α), and protein phosphatase 1A (PPM1A)/high mobility group box 1 (HMGB1) regulators. These mechanisms are believed to modulate the function of receptors, cytokines, and growth factors associated with RA. The review article includes data from preclinical and clinical trials that provide insights into potential treatment options for RA.

Plasma Cholinesterase Activity in Patients With Rheumatoid Arthritis and Toxoplasmosis

Background and objective Rheumatoid arthritis (RA) is a chronic autoimmune disease causing synovium inflammation and functional impairment. Toxoplasmosis is an intracellular zoonotic parasitic infection and a risk factor in immunosuppressed diseases including RA. The involvement of the cholinergic mechanism is not clear when both diseases exist in combination. This study aimed to examine plasma cholinesterase (ChE) activity in patients suffering from RA with concomitant toxoplasmosis, taking into account the enzyme susceptibility to in vitro inhibitory challenge with the organophosphate dichlorvos in RA patients. Methods This was a case-control study involving 88 RA patients and 61 healthy controls of both genders. The RA patients were allocated into three groups. The first group received no therapy (n=14), the second group received conventional anti-arthritis therapy (n=49), and the third group received conventional + biologic therapy (n=25). Plasma ChE activity was determined by an electrometric method. Plasma samples were screened for Toxoplasma gondii (T. gondii) infection, using ELISA T. gondii antibodies IgG and IgM. In vitro inhibition of plasma ChE activity was assessed by incubating the samples with dichlorvos at 0.25 and 0.5 μM. The time-dependent dichlorvos (0.25 μM)-induced plasma ChE inhibition and its kinetics were determined. Results The RA patients comprised 76 (86.4%) females and 12 males (13.6%), whereas healthy controls included 22 (36.1%) females and 39 (63.9%) males. The rates of toxoplasmosis IgG positivity in controls and RA patients were 26.2% and 39.8%, respectively. Plasma ChE activity in patients with RA was significantly higher than that in the control group, by 16%. Plasma ChE values of RA patients with conventional therapy and conventional + biologic therapy were higher than that of the control group, by 18% and 27%, respectively. Odds and risk ratios of elevated plasma ChE activity (20%) in RA patients with therapy indicated that high plasma ChE activity among RA patients with therapy is a risk factor. The plasma ChE activity of T. gondii IgG-positive RA patients was not significantly different from that of the IgG-negative ones. Dichlorvos at 0.25 and 0.5 μM significantly inhibited in vitro plasma ChE activity in controls and RA patients. The rates of plasma ChE inhibition by dichlorvos were lower in the RA groups with conventional therapy in comparison with those in the control group (77% vs. 91%). Examining the dichlorvos time-dependent ChE inhibition kinetics, RA groups showed increases in the half-life of inhibition by 23.6% to 32.7% and the total inhibition time by 23.5% to 32.5%, together with decreases in the inhibition rate constant by 19% to 24.5%, an indication of reduced inhibition rate of plasma ChE activity compared to that of the control group. Conclusions The autoimmune nature of RA and its chronicity might have contributed to the increase in plasma ChE activity among the patients. This increase in enzyme activity could be a risk factor in RA patients undergoing conventional therapy alone or in combination with biologic therapy; however, the clinical significance of such a condition remains obscure at present. The in vitro inhibition of plasma ChE activity in RA patients suggests reduced susceptibility of the enzyme to ChE inhibition by dichlorvos. Toxoplasmosis was not a risk factor when plasma ChE activity was taken into account among RA patients.