Azithromycin alleviates the severity of rheumatoid arthritis by targeting the UPR component GRP78

To be or not to be: the non-antimicrobial properties of common antimicrobials

Antibiotics are diverse in their utility in clinical care. They are widely prescribed for their antimicrobial effect and used as modulators, although rarely, of non-infectious conditions, to influence immune responses, to decrease morbidity and improve quality of life. This review provides a concise summary of different classes of antibiotics and their unique properties that allow them to be used in the treatment of non-infectious conditions.

Ghrelin/GHSR system attenuates collagen-induced arthritis in mice and ameliorates inflammation in human rheumatoid arthritis fibroblast-like synoviocytes

Ghrelin, an acylated peptide hormone, acts through its sole known receptor, the growth hormone secretagogue receptor (GHSR).Previous research indicated that ghrelin may be involved in rheumatoid arthritis (RA), yet the specific mechanisms remain unclear. This study aimed to explore the mechanism of ghrelin in RA synovial inflammation. Serum and synovial tissue from RA patients were collected for ghrelin expression analysis. We conducted our study using a collagen-induced arthritis (CIA) mouse model and an in vitro model using fibroblast-like synoviocytes (FLSs) induced by tumor necrosis factor-alpha (TNF-α). RNA-sequencing was performed to identify the potential signaling pathways involved in RA. Ghsr shRNA interference was used to assess whether the ghrelin receptor was involved. Ghrelin expression was decreased in synovial tissue of RA patients, and was negatively associated with TNF-α in the synovial fluid. In vivo experiments, acyl-ghrelin effectively suppressed CIA development, and Ghsr-/- mice exhibited the significantly aggravated arthritis symptoms of CIA mice. RNA sequence analyses of synovial tissue in Ghsr-/- and wild type mice indicated that ghrelin/GHSRsystem may inhibit inflammation through the PI3K/AKT pathway. In RA-FLSs, we found that acyl-ghrelin significantly suppressed the TNF-α induced increase in p-PI3K, p-AKT, p-NF-κB p65, IL-6 and IL-1β in RA FLSs. The effects of acyl-ghrelin on inflammatory factors were attenuated by the PI3K/AKT agonists. Ghsr shRNA reversed the anti-inflammatory effects of acyl-ghrelin. These results indicated that ghrelin/GHSR system has an important role in RA and could be a suitable candidate for RA therapy.

Association of antibiotic use with rheumatoid arthritis: A Mendelian randomization study

Previous observational studies have suggested an association between antibiotic use and rheumatoid arthritis (RA), though the causal relationship remains unclear. This study aimed to investigate the causal link between antibiotic use and RA in a European population using Mendelian randomization (MR). We utilized pooled genome-wide association study (GWAS) data on 12 antibiotics and RA from European populations, extracted from the GWAS Catalog. Both univariate MR and multivariate MR were employed to examine the causal relationship. Three analysis methods were applied: inverse variance weighting, MR-Egger, and weighted median, with inverse variance weighting as the primary method. Sensitivity analyses were conducted using Cochran Q statistics, MR-PRESSO, the MR-Egger intercept, and the leave-one-out test. Univariate MR revealed that tetracycline use was positively associated with RA (odds ratio = 1.013, 95% confidence interval = 1.001-1.024, P = .028), while none of the other 11 antibiotics exhibited a causal relationship with RA. However, further multivariate MR analysis found no causal association between tetracycline use and RA. Our results do not support a direct causal relationship between RA and antibiotic use, which may help alleviate some concerns among clinicians. Further MR studies are needed to validate these findings as additional datasets from other cohorts and GWASs with more detailed information become available.

The Differential Expressions and Associations of Intracellular and Extracellular GRP78/Bip with Disease Activity and Progression in Rheumatoid Arthritis

GRP78/BiP, a stress-induced protein and autoantigen in rheumatoid arthritis (RA), exhibits different expressions in various biological fluids and tissues, including blood, synovial fluid (SF), and synovium, all of which are pertinent to the disease activity and progression of RA; however, there is a scarcity of data linking both intracellular and extracellular GRP78/Bip to disease activity and progression of RA. This study was undertaken to investigate the differential expression of GRP78/Bip in blood, SF, and synovium, and to determine their association with disease activity and progression of RA. Patients with RA, osteoarthritis (OA), and traumatic meniscal injury (TMI) without radiographic OA were consecutively recruited for the study. Among patients with RA, six different subgroups were established based on their disease activity and progression. Disease activity was measured using the DAS28 (Disease activity scores in 28 joints) criterion, while disease progression was evaluated using the Steinbrocker classification grade. The levels of GRP78/Bip, TNF-α, and IL-10 were significantly elevated in the serum, SF, and synovium of patients with RA when compared to both the control (CON, TMI Patients) and the inflammation control (iCON, OA Patients) groups (p < 0.05). In terms of disease activity status, as opposed to remission status in RA, the levels of GRP78/Bip, TNF-α, and IL-10 were all elevated in serum and synovium (p < 0.05). However, GRP78/Bip and IL-10 levels were found to be reduced in SF, while TNF-α levels remained elevated. With respect to disease progression in RA, GRP78/Bip levels exhibited a positive correlation with both the stage of RA and the levels of TNF-α and IL-10 in serum and synovium. Nonetheless, a negative correlation was observed between GRP78/Bip levels and the stage of RA in SF, while positive correlations with the levels of TNF-α and IL-10 persisted. The differential expression of GRP78/Bip in blood, SF, and synovium indicated that the potential role and function of GRP78/Bip might vary depending on its specific location within these biological fluids and tissues. The presence of intracellular and extracellular GRP78/Bip was associated with disease activity and progression of RA, suggesting the involvement of GRP78/Bip in the pathogenesis and development of this debilitating autoimmune disorder, as well as its potential as a biomarker for monitoring disease activity and progression of RA.

Enhancing Student Comprehension of Glucose Metabolism Visualization Through Virtual Simulation Platform: An Educational Approach

With the rapid progression of biotechnology, the significance translational research on glycolysis in molecular pharmacology has become increasingly evident. To deepen students' understanding of glycolytic processes and facilitate their comprehension of drug action mechanisms, we have developed a visual virtual simulation platform dedicated glycolysis. The educational approach commenced with theoretical lectures on glycolysis, followed by practical laboratory sessions where students measured glycolysis-related parameters such as hexokinase, pyruvate kinase, and lactate. Students then engaged with the virtual simulation training platform to explore glycolytic stress tests and positron emission tomography/computed tomography (PET/CT) imaging, with their progress tracked through an assessment mode. The study involved 67 s-year undergraduate students majoring in biomedical sciences, all of whom had received instruction in glucose metabolism theories and completed the associated questionnaires. The results showed that the students gained a deeper understanding of glycolysis and the clinical application of PET/CT imaging in the context of glycolysis. The majority also agreed that the integration of scientific and clinical cases in teaching is beneficial and that the project sparked their interest in scientific research. These findings align with existing literature that emphasizes the importance of innovative educational tools in enhancing student engagement and understanding of the underlying theories of the curriculum. This project designed an innovative glycolytic metabolism teaching system encompassing the monitoring of traditional glycolytic indicators, glycolytic stress tests, and PET/CT imaging based on glycolysis. The visual virtual simulation platform for glycolysis can serve as an innovative educational tool in the molecular pharmacology curriculum or other courses involving glycolysis, assisting students in deeply understanding the molecular mechanisms of glycolysis and its significance in disease and drug action.

Chitosan-based self-healing thermosensitive hydrogel loaded with siHMGB1 for treatment of rheumatoid arthritis via macrophage repolarization

Rheumatoid arthritis (RA) is a prevalent autoimmune disease marked by immune cell activation, particularly macrophages. An imbalance between pro-inflammatory M1 and anti-inflammatory M2 macrophages causes synovial inflammation and joint damage, worsening RA. This study presents a biomacromolecular hydrogel delivery system with apoferritin nanoparticles for effective delivery of small interfering high mobility group protein (siHMGB1). The system was designed to promote the polarization of M1 macrophages to the M2 phenotype by downregulating the HMGB1/TLR4/NF-κB-p65 signaling pathway, offering a potential therapeutic approach for the treatment of RA. The oxidized chondroitin sulfate - chitosan - sodium glycerol β - phosphate - Fn/siHMGB1 (OCF/siHMGB1) hydrogel system possessed temperature-sensitive and self-healing properties, enabling the sustained, stable, and efficient release of siHMGB1 at the affected joint. After effective uptake by macrophages, siHMGB1 could effectively repolarize M1-phenotype macrophages to M2-phenotype via the HMGB1/TLR4/NF-κB-p65 signaling pathway both in vitro and in vivo. Additionally, it suppressed the release of pro-inflammatory cytokines and upregulated anti-inflammatory cytokines, which significantly blocked the TLR4/p65-mediated inflammatory signaling. In conclusion, the siHMGB1-loaded hydrogel delivery system designed in this study is effective in treating RA and highlights the potential of gene therapy to induce repolarization of M1 to M2 macrophages for RA treatment.

Ferroptosis and endoplasmic reticulum stress in rheumatoid arthritis

Ferroptosis is an iron-dependent mode of cell death distinct from apoptosis and necrosis. Its mechanisms mainly involve disordered iron metabolism, lipid peroxide deposition, and an imbalance of the antioxidant system. The endoplasmic reticulum is an organelle responsible for protein folding, lipid metabolism, and Ca2+ regulation in cells. It can be induced to undergo endoplasmic reticulum stress in response to inflammation, oxidative stress, and hypoxia, thereby regulating intracellular environmental homeostasis through unfolded protein responses. It has been reported that ferroptosis and endoplasmic reticulum stress (ERS) have an interaction pathway and jointly regulate cell survival and death. Both have also been reported separately in rheumatoid arthritis (RA) mechanism studies. However, studies on the correlation between ferroptosis and ERS in RA have not been reported so far. Therefore, this paper reviews the current status of studies and the potential correlation between ferroptosis and ERS in RA, aiming to provide a research reference for developing treatments for RA.

Hypothesis: Efficacy of early treatments with some NSAIDs in COVID-19: Might it also depend on their direct and/or indirect zinc chelating ability?

The present work argues for the involvement of the zinc chelating ability of some non-steroidal anti-inflammatory drugs as an additive mechanism able to increase their efficacy against COVID-19.

ATF6α contributes to rheumatoid arthritis by inducing inflammatory cytokine production and apoptosis resistance

Objective

The contribution of activating transcription factor 6α (ATF6α) in rheumatoid arthritis (RA) pathogenesis, especially on fibroblast-like synoviocytes (FLSs), has been suggested by its sensitivity to inflammatory stimulus. However, the exact role and therapeutic potential of ATF6α in RA remains to be fully elucidated.

Methods

ATF6α expression was determined in joint tissues and FLS, and gain-of-function and loss-of-function analyses were applied to evaluate the biological roles of ATF6α in RA FLSs. A murine collagen-induced arthritis (CIA) model, combining both gene deletion of ATF6α and treatment with the ATF6α inhibitor Ceapin-A7, was employed. Joint inflammation, tissue destruction, circulating levels of inflammatory cytokines were assessed in CIA mice. Transcriptome sequencing analysis (RNASeq), molecular biology, and biochemical approaches were performed to identify target genes of ATF6α.

Results

ATF6α expression was significantly increased in synovium of RA patients and in synovium of mice subjected to CIA. ATF6α silencing or inhibition repressed RA FLSs viability and cytokine production but induced the apoptosis. CIA-model mice with ATF6α deficiency displayed decreased arthritic progression, leading to profound reductions in clinical and proinflammatory markers in the joints. Pharmacological treatment of mice with Ceapin-A7 reduced arthritis severity in CIA models. RNA-sequencing of wild-type and knockdown of ATF6α in RA FLSs revealed a transcriptional program that promotes inflammation and suppresses apoptosis, and subsequent experiments identified Baculoviral IAP Repeat Containing 3 (BIRC3) as the direct target for ATF6α.

Conclusion

This study highlights the pathogenic role of ATF6α-BIRC3 axis in RA and identifies a novel pathway for new therapies against RA.

PET imaging to assess fibroblast activation protein inhibitor biodistribution: A training program adapted to pharmacology education

In the process of pharmacology education, practical teaching is an important complement to theoretical teaching. These activities include the use of experimental animals to obtain certain pharmacological parameters or to help students understand certain classical concepts. However, the growing interest in laboratory animal welfare, the rapid development of pharmacology research and the challenges of cultivating innovative pharmacy talent create a need for innovative and flexible in vitro experiments for teaching purposes. Here, we report the application of positron emission tomography (PET) imaging of 18 F-labeled fibroblast activation protein inhibitor (18 F-FAPi) to practical pharmacology teaching, enabling dynamic visualization of the distribution and excretion process of FAPi in mice. Students can quantitatively analyze the distribution of FAPi in various tissues and organs without sacrificing the mice. Furthermore, the newly implemented method resulted in highly reproducible results and was generally appreciated by the students. Additionally, the application of PET imaging in pharmacokinetic teaching can not only greatly reduce the use of experimental animals but also need not sacrificing animals. Of note is that dynamic scanning data from this project can be used for online practical teaching during COVID-19 pandemic.

Endoplasmic Reticulum Stress, Oxidative Stress, and Rheumatic Diseases

BACKGROUND

The endoplasmic reticulum (ER) is a multi-functional organelle responsible for cellular homeostasis, protein synthesis, folding and secretion. It has been increasingly recognized that the loss of ER homeostasis plays a central role in the development of autoimmune inflammatory disorders, such as rheumatic diseases. Purpose/Main contents: Here, we review current knowledge of the contribution of ER stress to the pathogenesis of rheumatic diseases, with a focus on rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). We also review the interplay between protein folding and formation of reactive oxygen species (ROS), where ER stress induces oxidative stress (OS), which further aggravates the accumulation of misfolded proteins and oxidation, in a vicious cycle. Intervention studies targeting ER stress and oxidative stress in the context of rheumatic diseases are also reviewed.

CONCLUSIONS

Loss of ER homeostasis is a significant factor in the pathogeneses of RA and SLE. Targeting ER stress, unfolded protein response (UPR) pathways and oxidative stress in these diseases both in vitro and in animal models have shown promising results and deserve further investigation.

Euphorbia factor L3 ameliorates rheumatoid arthritis by suppressing the inflammatory response by targeting Rac family small GTPase 1

Euphorbia factor L3 (EFL3) is extracted from Euphorbia lathyris and is known for its anti-inflammatory properties. This study focused on the potential anti-inflammatory and therapeutic effects of EFL3 on rheumatoid arthritis (RA) using fibroblast-like synoviocytes (FLSs) and arthritis animal models. Functional analysis showed that EFL3 could ameliorate the inflammatory phenotype of FLSs derived from RA patients, as evidenced by the decreases in cell viability, migration, invasion and cytokine production. Luciferase activity, Western blotting and immunofluorescence assays demonstrated that EFL3 inhibited the nuclear translocation of the p65 subunit and the subsequent activation of the nuclear factor kappa-Β (NF-κB) pathway. Furthermore, the therapeutic effects of EFL3 against arthritic progression were evidenced by decreases in joint swelling, arthritis scores, inflammatory factor production, synovial hyperplasia, and bone destruction in collagen-induced arthritis (CIA) and tumor necrosis factor-α (TNF-α) transgenic (TNF-tg) mouse models. Molecular analysis identified Rac family small GTPase 1 (Rac1) as the potential target that was required for EFL3-mediated suppression of the inflammatory RA FLS phenotype. In summary, this study uncovered the therapeutic potential of EFL3 in RA, which suggests its future clinical use.

Role of mitochondrial dynamics and mitophagy of vascular smooth muscle cell proliferation and migration in progression of atherosclerosis

Vascular smooth muscle cell (VSMC) proliferation and migration are critical events that contribute to the pathogenesis of vascular diseases such as atherosclerosis, restenosis, and hypertension. Recent findings have revealed that VSMC phenotype switching is associated with metabolic switch, which is related to the role of mitochondria. Mitochondrial dynamics are directly associated with mitochondrial function and cellular homeostasis. Interestingly, it has been suggested that mitochondrial dynamics and mitophagy play crucial roles in the regulation of VSMC proliferation and migration through various mechanisms. Especially, dynamin-related protein-1 and mitofusion-2 are two main molecules that play a key role in regulating mitochondrial dynamics to induce VSMC proliferation and migration. Therefore, this review describes the function and role of mitochondrial dynamics and mitophagy in VSMC homeostasis as well as the underlying mechanisms. This will provide insight into the development of innovative approaches to treat atherosclerosis.