[New therapies for rheumatoid arthritis]

Hecogenin and its derivates: A pharmacology review

Despite the several uses of drugs from natural compounds in the pharmaceutical industry, new molecules have been discovered and associated with pharmacological activities over the years. Hecogenin, a steroidal saponin, has been the subject of several studies due to reports of pharmacological activities. This study combines the articles published to date that show the pharmacological activity and the mechanism of action of hecogenin, its acetate, and its derivates. This compilation shows that the compounds can act in different pathologies that affect many systems of the human body. They showed pharmacological properties in inflammation, mediating cytokines, cells, and environment. Also, it participated in tumoral processes by pathways like PPGARγ, ERK½, and MMP-2 and showed antimicrobial effects against organisms like Candida and Aedes aegypti's larvae. This review indicates that continuing studies with these molecules are essential once they have the potential to be a future drug.

The regulatory mechanism and potential application of IL-23 in autoimmune diseases

IL-23 is a heterodimeric pro-inflammatory cytokine secreted by dendritic cells and macrophages that belongs to the IL-12 family. It has pro-inflammatory effects and is a key cytokine and upstream regulatory cytokine involved in protective immune responses, stimulating the differentiation and proliferation of downstream effectors such as Th17 cells. It is expressed in various autoimmune diseases such as psoriasis, systemic lupus erythematosus (SLE), rheumatoid arthritis (RA). The IL-23/TH17 axis formed by IL-23 and TH17 has been confirmed to participate in autoimmune diseases pathogenesis. IL-23R is the receptor for IL-23 and plays an activating role. Targeting IL-23 is currently the main strategy for the treatment of various autoimmune diseases. In this review we summarized the mechanism of action and clinical application potential of IL-23 in autoimmune diseases by summarizing the latest research results and reviewing the literature, which would help to further understand IL-23 and provide a theoretical basis for future clinical targeting and drug development.

The Role of Zinc and Zinc Homeostasis in Macrophage Function

Zinc has long been recognized as an essential trace element, playing roles in the growth and development of all living organisms. In recent decades, zinc homeostasis was also found to be important for the innate immune system, especially for maintaining the function of macrophages. It is now generally accepted that dysregulated zinc homeostasis in macrophages causes impaired phagocytosis and an abnormal inflammatory response. However, many questions remain with respect to the mechanisms that underlie these processes, particularly at the cellular and molecular levels. Here, we review our current understanding of the roles that zinc and zinc transporters play in regulating macrophage function.

Acid-sensing ion channel 1a mediates acid-induced inhibition of matrix metabolism of rat articular chondrocytes via the MAPK signaling pathway

The acid-sensing ion channel 1a (ASIC1a), which is activated by extracellular acid, contributes to the pathogenesis of rheumatoid arthritis. However, it remains unclear whether ASIC1a mediates acid-induced matrix metabolism in rat articular chondrocytes via activation of the MAPK signaling pathway. In the current study, we found that extracellular acidification (pH 6.0) inhibited proliferation and induced apoptosis of articular chondrocytes in a dose-dependent manner, while the expression of phosphorylated ERK1/2 and P38 MAPK increased, but, this effect was blocked by the Ca²⁺ chelator BAPTA-AM and the ASIC1a-specific blocker PcTx-1. In addition, extracellular acidification increased the expression of c-fos, GAG, HYP, and TIM1/2. These effects were inhibited by the Ca²⁺ chelator BAPTA-AM, ERK1/2 inhibitor PD98059, and ASIC1a-specific blocker PcTx-1, but not the P38 MAPK inhibitor SB203580. Finally, extracellular acidification increased the expression of c-jun and MMP-2/9, and these effects were blocked by the Ca²⁺ chelator BAPTA-AM, P38 MAPK inhibitor SB203580, and ASIC1a-specific blocker PcTx-1, but not the ERK1/2 inhibitor PD98059. In conclusion, ASIC1a inhibits the expression of MMP-2/9, GAG, HYP, and TIMP-1/2 by the Ca²⁺-dependent P38 MAPK/c-jun and ERK/c-fos signaling pathways.

Ocular surface findings in patients with rheumatoid arthritis under methotrexate or biological agent therapy

PURPOSE

To evaluate the ocular findings in patients with rheumatoid arthritis (RA) treated with disease-modifying antirheumatic drugs (DMARDs) such as methotrexate (MTX) or MTX with biological agents.

METHODS

One hundred and twelve eyes of 56 patients with RA and treated with MTX or MTX with biological agents were included in the study. Patients were divided into two groups using DMARDs only (group 1) and patients using DMARDs and biologic agents together (group 2). In both groups; Schirmer's II test, tear film break-up time (tBUT), central corneal thickness (CCT), corneal volume (CV), intraocular pressure (IOP) measurement, and anterior segment and fundus examinations of the eye with slit lamp were carried out. Ocular surface disease index (OSDI) score questionnaire were performed.

RESULTS

Thirty-eight patients with a mean age of 53.00 ± 8.19 years were in group 1 and 18 patients with a mean age of 51.00 ± 9.54 years were in group 2. The mean duration of RA was 6.89 ± 7.96 years in group 1 and 5.70 ± 9.00 years in group 2. There was a statistically significant difference between two groups with tBUT, CCT, CV, IOP (p < 0.05) and there was no significant difference with age, sex, disease duration, disease activity, and Schirmer's II test (p > 0.05). The disease duration showed a significant moderate negative correlation with CCT and CV in group 2 (p < 0.05).

CONCLUSIONS

Although tBUT values were significantly higher in the combination treatment group, CCT and CV values were significantly lower. Due to the decrease in corneal thickness, IOP was determined to be significantly lower.

ADAMTS-12: a multifaced metalloproteinase in arthritis and inflammation

ADAMTS-12 is a member of a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) family of proteases, which were known to play important roles in various biological and pathological processes, such as development, angiogenesis, inflammation, cancer, arthritis, and atherosclerosis. In this review, we briefly summarize the structural organization of ADAMTS-12; concentrate on the emerging role of ADAMTS-12 in several pathophysiological conditions, including intervertebral disc degeneration, tumorigenesis and angioinhibitory effects, pediatric stroke, gonad differentiation, trophoblast invasion, and genetic linkage to schizophrenia and asthma, with special focus on its role in arthritis and inflammation; and end with the perspective research of ADAMTS-12 and its potential as a promising diagnostic and therapeutic target in various kinds of diseases and conditions.