Biomarker Approach Towards Rheumatoid Arthritis Treatment

LC-MS-based rheumatoid arthritis serum metabolomics reveals the role of deoxyinosine in attenuating collagen-induced arthritis in mice

Rheumatoid arthritis (RA) is a persistent autoimmune condition with no identified cure currently. Recently, scientists have applied metabolomics to investigate altered metabolic profiles and unique diseases-associated metabolic signatures. Herein, we applied metabolomics approach to analyze serum samples of 41 RA patients and 42 healthy controls (HC) with the aim to characterize RA patients' metabolic profile, investigate related underlying pathological processes, and identify target metabolites. By utilizing ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry, we found 168 proposed metabolites and 45 vital metabolic pathways. Our analysis revealed that deoxyinosine (DI), a metabolite of the purine metabolic pathway, was the most significant reduced metabolite in RA patients. Furthermore, through targeted detection, we confirmed lower concentration of DI in RA patients' peripheral blood. Moreover, DI inhibited lipopolysaccharide-induced inflammation both in vitro and in vivo. We further assessed DI's therapeutic potential in a collagen-induced arthritis (CIA) murine model. The results revealed that DI attenuated CIA, as evidenced by significantly lowered clinical scores of arthritis, alleviated joint swelling, and mitigated bone destruction. Moreover, we elucidated the underlying mechanism by which DI increased the population of myeloid-derived suppressor cells (MDSCs) and suppressed the proliferation of induced T cells. Collectively, these findings suggested that DI potentially ameliorated RA by inducing immunosuppressive MDSCs. The study provides key observations on RA pathogenesis and may contribute to developing novel therapeutic strategies for this debilitating condition.

Exosomes and exosomal miRNAs: A new avenue for the future treatment of rheumatoid arthritis

Rheumatoid arthritis is a chronic systemic autoimmune disease that involves mainly synovitis and joint injury and is one of the main causes of disability. The pathogenesis of rheumatoid arthritis is complicated, and the treatment cycle is long. The traditional methods of inhibiting inflammation and immunosuppression are no longer sufficient for treatment of the disease, so there is an urgent need to seek new treatments. The exocrine microenvironment is a kind of microvesicle with a lipid bilayer membrane structure that can be secreted by most cells in the body. This structure contains cell-specific proteins, lipids and nucleic acids that can transmit this information from one cell to another. To achieve cell-to-cell communication. Exocrine microRNAs can be contained in exocrine cells and can be selectively transferred to target receptor cells via exocrine signaling, thus regulating the physiological function of target cells. This article focuses on the pathological changes that occur during the development of rheumatoid arthritis and the biological regulation of exocrine and exocrine microRNAs in rheumatoid joints. Research on the roles of exocrine and exocrine microRNAs in regulating the inflammatory response, cell proliferation/apoptosis, autophagy, effects on fibroblast-like synoviocytes and immune regulation in rheumatoid arthritis was reviewed. In addition, the challenges faced by this new treatment are discussed.

Preventive and therapeutic effects of low-dose whole-body irradiation on collagen-induced rheumatoid arthritis in mice

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by progressive joint inflammation, resulting in cartilage destruction and bone erosion. It was reported that low-dose radiation modulates immune disease. Here, we investigated whether low-dose whole-body irradiation has preventive and therapeutic effects in collagen-induced RA (CIA) mouse models. Fractionated low-dose irradiation (0.05 Gy/fraction, total doses of 0.1, 0.5 or 0.8 Gy) was administered either concurrently with CIA induction by Type II collagen immunization (preventive) or after CIA development (therapeutic). The severity of CIA was monitored using two clinical parameters, paw swelling and redness. We also measured total Immunoglobulin G (IgG) and inflammatory cytokines (interleukine (IL)-6, IL-1β and tumor necrosis factor-alpha (TNF-α)) in the serum by enzyme-linked immunosorbent assay, and we evaluated histological changes in the ankle joints by immunohistochemistry and hematoxylin and eosin staining. Low-dose irradiation reduced CIA clinical scores by up to 41% in the preventive model and by 28% in the therapeutic model, while irradiation in the preventive model reduced the typical CIA incidence rate from 82 to 56%. In addition, low-dose irradiation in the preventive model decreased total IgG by up to 23% and decreased IL-1β and TNF-α by 69 and 67%, and in the therapeutic model, decreased total IgG by up to 35% and decreased IL-1β and IL-6 by 59 and 42% with statistical significance (P < 0.01, 0.05 and 0.001). Our findings demonstrate that low-dose radiation has preventive and therapeutic anti-inflammatory effects against CIA by controlling the immune response, suggesting that low-dose radiation may represent an alternative therapy for RA, a chronic degenerative immune disease.

Exploring the mechanism of Celastrol in the treatment of rheumatoid arthritis based on systems pharmacology and multi-omics

To explore the molecular network mechanism of Celastrol in the treatment of rheumatoid arthritis (RA) based on a novel strategy (integrated systems pharmacology, proteomics, transcriptomics and single-cell transcriptomics). Firstly, the potential targets of Celastrol and RA genes were predicted through the database, and the Celastrol-RA targets were obtained by taking the intersection. Then, transcriptomic data and proteomic data of Celastrol treatment of RA were collected. Subsequently, Celastrol-RA targets, differentially expressed genes, and differentially expressed proteins were imported into Metascape for enrichment analysis, and related networks were constructed. Finally, the core targets of Celastrol-RA targets, differentially expressed genes, and differentially expressed proteins were mapped to synoviocytes of RA mice to find potential cell populations for Celastrol therapy. A total of 195 Celastrol-RA targets, 2068 differential genes, 294 differential proteins were obtained. The results of enrichment analysis showed that these targets, genes and proteins were mainly related to extracellular matrix organization, TGF-β signaling pathway, etc. The results of single cell sequencing showed that the main clusters of these targets, genes, and proteins could be mapped to RA synovial cells. For example, Mmp9 was mainly distributed in Hematopoietic cells, especially in Ptprn+fibroblast. The results of molecular docking also suggested that Celastrol could stably combine with molecules predicted by network pharmacology. In conclusion, this study used systems pharmacology, transcriptomics, proteomics, single-cell transcriptomics to reveal that Celastrol may regulate the PI3K/AKT signaling pathway by regulating key targets such as TNF and IL6, and then play an immune regulatory role.

Based on mRNA Sequencing Techniques to Explore the Molecular Mechanism of Buzhong Yiqi Decoction for Autoimmune Thyroiditis

OBJECTIVE

Autoimmune diseases (AD) account for a high percentage of the population. One of the most prevalent is autoimmune thyroiditis (AIT). However, the therapeutic effects of Buzhong Yiqi (BZYQ) decoction on AIT have not been studied yet. The majority of the present study was conducted on NOD.H-2h4 mice in an attempt to ascertain the therapeutic effects of BZYQ decoction on AIT.

METHODS

The 0.05% sodium iodide water (NaI)-induced AIT mice model was established. A total of nine NOD.H-2h4 mice were randomly divided into three groups: the normal group provided with regular water, the model group drinking freely 0.05% NaI, and the treatment group treated with BZYQ decoction (9.56 g/kg) after NaI supplementation (NaI + BZYQ). BZYQ decoction was administered orally once daily for eight weeks. The thyroid histopathology test was used to measure the severity of lymphocytic infiltration. An enzyme-linked immunosorbent assay (ELISA) was used to determine the levels of anti-thyroglobulin antibody (TgAb), interleukin (IL)-1β, IL-6, and IL-17. The Illumina HiSeq X sequencing platform was utilized to analyze the thyroid tissue by mRNA expression profiles. Bioinformatics analysis was used to investigate the biological function of the differentially expressed mRNAs. In addition, the expression of Carbonyl Reductase 1 (CBR1), 6-Pyruvoyltetrahydropterin Synthase (PTS), Major Histocompatibility Complex, Class II (H2-EB1), Interleukin 23 Subunit Alpha (IL-23A), Interleukin 6 Receptor (IL-6RA), and Janus Kinase 1 (JAK1) was measured by quantitative real-time PCR (qRT-PCR).

RESULTS

The treatment group exhibited significantly lower rates of thyroiditis and lymphocyte infiltration compared to the model group. Serum levels of TgAb, IL-1β, IL-6, and IL-17 were significantly higher in the model group, but they fell dramatically after BZYQ decoction administration. According to our results, 495 genes showed differential expression in the model group compared to the control group. Six hundred twenty-five genes were significantly deregulated in the treatment group compared to the model group. Bioinformatic analysis showed that most mRNAs were associated with immune-inflammatory responses and were involved in multiple signaling pathways, including folate biosynthesis and the Th17 cell differentiation pathway. CBR1, PTS, H2-EB1, IL- 23A, IL-6RA and JAK1 mRNA participated in folate biosynthesis and the Th17 cell differentiation pathway. The qRT-PCR analysis confirmed that the above mRNAs were regulated in the model group compared to the treatment group Conclusion: The results of this investigation have revealed novel insights into the molecular mechanism of action of BZYQ decoction against AIT. The mechanism may be partially attributed to the regulation of mRNA expression and pathways.

Analysis of the Relationship between Rheumatoid Arthritis and Osteoporosis Based on Mendelian Randomization

BACKGROUND

As the global population ages, the World Health Organization has found a yearly increase in the incidence of rheumatoid arthritis and osteoporosis. This trend poses a challenge to public health and healthcare and calls for the implementation of more preventive and treatment measures to address these health issues.

OBJECTIVE

This study aims to investigate the causal relationship between rheumatoid arthritis (RA) and osteoporosis (OP) using the Mendelian randomization (MR) method.

METHODS

OP diagnosis was based on the gold standard of bone mineral density (BMD). Single nucleotide polymorphisms (SNPs) were identified from the genome-wide association research database formed by RA and BMD, with a parameter setting of P < 5×10-8, chain imbalance r2<0.01, and kb = 10,000. Five complementary MR methods, including inverse variance weighted (IVW), MR-Egger regression, weighted median, simple mode estimation based on mode, and weighted estimation based on mode, were used to evaluate the causal relationship between RA and OP/BMD using odds ratio (OR) values and 95% confidence intervals (CI). Sensitivity analyses were performed using heterogeneity tests, horizontal pleiotropy, and individual rejection tests.

RESULTS

A total of 78 instrumental variables were identified that were closely related to both RA and BMD in mixed populations, while 14 instrumental variables were identified in the European population and 38 instrumental variables were identified in the Asian population. Using IVW as the main analysis method, the MR analysis results of RA and BMD showed the following: mixed population OR = 0.96, 95%CI: 0.93-1.00; European population OR = 0.55, 95%CI: 0.27-1.12; and Asian population OR = 0.95, 95%CI: 0.90-1.01. Sensitivity analyses showed that the MR results were robust.

CONCLUSION

The study found insufficient evidence of a causal relationship between RA and OP/BMD, suggesting that RA may not have a direct effect on OP/BMD.

Immune-regulating strategy against rheumatoid arthritis by inducing tolerogenic dendritic cells with modified zinc peroxide nanoparticles

In hypoxic dendritic cells (DCs), a low level of Zn²⁺ can induce the activation of immunogenic DCs (igDCs), thereby triggering an active T-cell response to propel the immune progression of rheumatoid arthritis (RA). This finding indicates the crucial roles of zinc and oxygen homeostasis in DCs during the pathogenesis of RA. However, very few studies have focused on the modulation of zinc and oxygen homeostasis in DCs during RA treatment. Proposed herein is a DC-targeting immune-regulating strategy to induce igDCs into tolerogenic DCs (tDCs) and inhibit subsequent T-cell activation, referred to as ZnO₂/Catalase@liposome-Mannose nanoparticles (ZnCM NPs). ZnCM NPs displayed targeted intracellular delivery of Zn²⁺ and O₂ towards igDCs in a pH-responsive manner. After inactivating OTUB1 deubiquitination, the ZnCM NPs promoted CCL5 degradation via NF-κB signalling, thereby inducing the igDC-tDC transition to further inhibit CD4⁺ T-cell homeostasis. In collagen-induced arthritis (CIA) mice, this nanoimmunoplatform showed significant accumulation in the spleen, where immature DCs (imDCs) differentiated into igDCs. Splenic tDCs were induced to alleviate ankle swelling, improve walking posture and safely inhibit ankle/spleen inflammation. Our work pioneers the combination of DC-targeting nanoplatforms with RA treatments and highlights the significance of zinc and oxygen homeostasis for the immunoregulation of RA by inducing tDCs with modified ZnO₂ NPs, which provides novel insight into ion homeostasis regulation for the treatment of immune diseases with a larger variety of distinct metal or nonmetal ions.

The DC-targeting immune-regulating nanostrategy was firstly employed to treat RA.

The complex immune regulating effects was realized through a portable, convenient and green nanomaterial.

Highlighting the significance of zinc and oxygen homeostasis for the immunoregulation of RA by inducing tDCs with modified ZnO₂ NPs.

Expanding the notion of ion homeostasis regulation with a larger variety of distinct metal or nonmetal ions.