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

Morinda officinalis iridoid glycosides alleviate methotrexate-induced liver injury in CIA rats by increasing liver autophagy and improving lipid metabolism homeostasis

ETHNOPHARMACOLOGICAL RELEVANCE

Morinda officinalis How. is a commonly used traditional Chinese herb with the pharmacological properties of tonifying liver and kidney, and enhancing bone and muscle. Iridoid glycosides are the predominant components of this plant, including monotropein, asperuloside, deacetylasperuloside and deacetylasperulosidic acid with their contents reaching more than 2%. Methotrexate (MTX) is the drug of choice for the treatment of rheumatoid arthritis (RA), but liver injury induced by MTX limits its wider use for RA. Morindaofficinalis iridoid glycoside (MOIG) is reported as having anti-RA and hepatoprotective effects, but the exact efficacy on MTX-induced liver injury and the underlying molecular mechanism remain unclear.

AIM

To elucidate the mitigating effect of MOIG against liver injury in RA rats treated with MTX, and explore the possible mechanism.

MATERIALS AND METHODS

The effect and mechanism of MOIG were investigated in Wistar rats with collagen-induced arthritis (CIA) which were then treated with MTX, and MTX-induced hepatocyte injury in vitro. Network pharmacological and transcriptomic analyses were conducted to predict the possible mechanisms of MOIG in mitigating MTX-induced liver injury, and lipidomic analysis was performed to further verify the regulatory effects of MOIG on lipid metabolism. BRL-3A hepatocytes were used to evaluate the regulatory effects of MOIG against MTX-associated liver injury.

RESULTS

MOIG treatment enhanced the anti-RA effect of MTX, and mitigated oxidative damage, inflammation and apoptosis of liver tissues in CIA rats treated with MTX. Network pharmacological and transcriptomic analyses demonstrated that MOIG attenuated liver injury by regulating autophagy and lipid metabolism. The result of lipidomic analysis showed that MOIG reversed the disturbance of lipid metabolism of the liver tissue in CIA rats after MTX treatment. In addition, MOIG also inhibited the apoptosis, reduced the levels of lactate dehydrogenase (LDH), aspartate aminotransferase (ALT) and alanine aminotransferase (AST), regulated oxidative stress, and increased the formation of autophagosome and translocation of LC3 in the nucleus and expression of autophagy regulatory genes Beclin-1, ATG5, LC3Ⅱ, ATG7 and ATG12 in hepatocytes subjected to MTX damage.

CONCLUSION

Our findings demonstrated that MOIG could ameliorate MTX-induced liver injury in the treatment of RA through increasing hepatocyte autophagy and improving lipid metabolism homeostasis.

Role of IL-1 Family Cytokines IL-36, IL-37, IL-38 in Osteoarthritis and Rheumatoid Arthritis: A Comprehensive Review

Inflammatory cytokines, interleukin-36 (IL-36), IL-37, IL-38 belong to IL-1 family. The IL-36 subfamily obtains pro- and anti-inflammatory effects on various immune responses. Cytokine IL-37, has anti-inflammatory functions in immunity, and the recently identified IL-38 negatively associated with disease pathogenesis. To date, expression of IL-36, IL-37, IL-38 is reported dysregulated in osteoarthritis (OA) and rheumatoid arthritis (RA), and may be disease markers for arthritis-related diseases. Interestingly, expression of IL-38 was different either in OA patients or animal models, and expression of IL-36Ra in synovium was different in OA and RA patients. Moreover, functional studies have demonstrated significant role of these cytokines in OA and RA progress. These processes were related to immune cells and non-immune cells, where the cytokines IL-36, IL-37, IL-38 may regulate downstream signalings in the cells, and then involve in OA, RA development. In this review, we comprehensively discuss recent advancements in cytokines and the development of OA, RA. We hope that targeting these cytokines will become a potential treatment option for OA and RA in the future.

Phloridzin reduces synovial hyperplasia and inflammation in rheumatoid arthritis rat by modulating mTOR pathway

Rheumatoid arthritis (RA) is an inflammatory autoimmune disease and management of it still a challenge. Given report evaluates protective effect of phlorizin on RA and also postulates the molecular mechanism of its action. Bovine type II collagen (CIA) and Freund's incomplete adjuvant (1:1 and 1 mg/ml) was administered on 1st and 8th day of protocol to induce RA in rats and treatment with phlorizin 60 and 120 mg/kg was started after 4th week of protocol. Level of inflammatory cytokines and expression of proteins were estimated in phlorizin treated RA rats. Moreover in-vitro study was performed on Fibroblast-like synoviocytes (FLSs) and effect of phlorizin was estimated on proliferation, apoptosis and expression of mTOR pathway protein after stimulating these cell lines with Tumour Necrosis Factor alpha (TNF-α). Data of study suggest that phlorizin reduces inflammation and improves weight in CIA induced RA rats. Level of inflammatory cytokines in the serum and expression of Akt/PI3K/mTOR proteins in the join tissue was reduced in phlorizin treated RA rats. Phlorizin also reported to reverse the histopathological changes in the joint tissue of RA rats. In-vitro study supports that phlorizin reduces proliferation and no apoptotic effect on TNF-α stimulated FLSs. Expression of Akt/PI3K/mTOR proteins also downregulated in phlorizin treated TNF-α stimulated FLSs. In conclusion, phlorizin protects inflammation and reduces injury to the synovial tissues in RA, as it reduces autophagy by regulating Akt/PI3K/mTOR pathway.

The 5' untranslated region variant rs3811050 C/T of the interleukin-38 encoding gene is associated with susceptibility to rheumatoid arthritis in Iraqi women

BACKGROUND

Interleukin (IL)-38, the latest member of the IL-1 cytokine family, is proposed to have a pathogenic role in rheumatoid arthritis (RA). It is encoded by the IL1F10 gene, which harbors single nucleotide polymorphisms (SNPs) that may predict the risk of autoimmune diseases. Among them are 5' untranslated region (UTR) SNPs, which play a key role in post-transcriptional control, but have not been studied in Iraqi RA patients.

METHODS

Two novel IL1F10 5'UTR SNPs (rs3811050 C/T and rs3811051 T/G) were explored in RA and control women (n = 120 and 110, respectively). SNPs were genotyped using TaqMan assay. An ELISA kit was used to measure serum IL-38 concentrations.

RESULTS

A reduced risk of RA was associated with rs3811050 T allele and CT genotype (corrected probability [pc] = 0.01 and < 0.001, respectively), while there was no significant association with rs3811051. Haplotype analysis demonstrated that C-T haplotype was associated with a 1.65-fold greater risk of RA, whereas a reduced risk was linked to T-G haplotype. IL-38 concentrations were higher in patients than in controls (p < 0.001). In addition, IL-38 showed acceptable performance in distinguishing between RA and control women (p < 0.001). When IL-38 concentrations were stratified according to SNP genotypes, no significant differences were found.

CONCLUSIONS

The rs3811050 variant was more likely to affect RA susceptibility in Iraqi women, and the T allele may play a role in reducing disease risk. IL-38 concentrations were elevated in RA patients, but were not affected by the rs3811050 and rs3811051 genotypes.

Emerging Role of Interleukin-38 (IL-38) in the Development of Rheumatoid Arthritis

INTRODUCTION

Rheumatoid arthritis (RA) is an incurable autoimmune disease. The role of interleukin-38 (IL-38), an anti-inflammatory cytokine, in RA is not fully understood, and its clinical relevance in RA remains unclear. This study aims to investigate the correlation of IL-38 with disease activity and the clinical manifestation of RA.

METHODS

In this cross-sectional study, patients with treatment-naïve RA (n = 63) and healthy controls (HC) (n = 60) were consecutively enrolled over a 15-month period. Patients with RA were categorized into three subgroups-low disease activity (LDA), moderate disease activity (MDA) and high disease activity (HDA)-using the Disease Activity Score in 28 joints based on C-reactive protein (DAS28-CRP). Circulating levels of IL-38, tumour necrosis factor (TNF), IL-6, IL-17, IL-1β, and 25(OH)D were assessed using enzyme-linked immunosorbent assay (ELISA). Clinical data, including duration, tender joints count (TJC), swollen joints count (SJC), patient global assessment (PGA), evaluator global assessment (EGA), bone mineral density (BMD), clinical disease activity index (CDAI), simplified disease activity index (SDAI), DAS28-CRP, joint musculoskeletal ultrasound (MSUS), and serological indicators were recorded. We determined the correlation between IL-38 and disease activity, as well as clinical manifestation in RA.

RESULTS

At the macroscopic level, musculoskeletal ultrasonography of joints in different stages of disease activity in RA suggests that, as the disease progresses, arthritis in the hand becomes more severe, accompanied by synovial thickening and pronounced blood flow signals in the joint area. The expression of IL-38, TNF, IL-6, IL-17 and IL-1β significantly increased in patients with RA compared to HC. Noteworthy differences were observed in the blood flow signal score, synovial signal score, IL-38, TNF, IL-6, IL-17 and IL-1β among the three subgroups (LDA, MDA and HDA). As disease activity increased in patients with RA, the blood flow signal score, synovial signal score and expression of TNF, IL-6, IL-17 and IL-1β exhibited a gradual increase, while the expression of IL-38 showed the opposite pattern. Inverse correlations were identified between IL-38 and pro-inflammatory cytokines (IL-6, IL-17), as well as key clinical parameters, including disease duration, SJC, TJC and DAS28-CRP score.

CONCLUSION

IL-38, intricately linked to the pathogenesis of RA, emerges as a promising therapeutic target for the management of this debilitating disease.

Unraveling the role of HIF-1α in sepsis: from pathophysiology to potential therapeutics-a narrative review

Sepsis is characterized by organ dysfunction resulting from a dysregulated inflammatory response triggered by infection, involving multifactorial and intricate molecular mechanisms. Hypoxia-inducible factor-1α (HIF-1α), a notable transcription factor, assumes a pivotal role in the onset and progression of sepsis. This review aims to furnish a comprehensive overview of HIF-1α's mechanism of action in sepsis, scrutinizing its involvement in inflammatory regulation, hypoxia adaptation, immune response, and organ dysfunction. The review encompasses an analysis of the structural features, regulatory activation, and downstream signaling pathways of HIF-1α, alongside its mechanism of action in the pathophysiological processes of sepsis. Furthermore, it will delve into the roles of HIF-1α in modulating the inflammatory response, including its association with inflammatory mediators, immune cell activation, and vasodilation. Additionally, attention will be directed toward the regulatory function of HIF-1α in hypoxic environments and its linkage with intracellular signaling, oxidative stress, and mitochondrial damage. Finally, the potential therapeutic value of HIF-1α as a targeted therapy and its significance in the clinical management of sepsis will be discussed, aiming to serve as a significant reference for an in-depth understanding of sepsis pathogenesis and potential therapeutic targets, as well as to establish a theoretical foundation for clinical applications.

Mucous cell histopathology and label-free quantitative proteomic analysis of skin mucus in fat greenling (Hexagrammos otakii) infected with Vibrio harveyi

Hexagrammos otakii is favored by consumers and aquaculture practitioners because of its strong adaptability and fast growth. However, recently, frequent outbreaks of diseases in the breeding of H. otakii have led to significant economic losses, especially due to bacterial diseases, which limit the healthy breeding of H. otakii. As a luminescent Gram-negative bacterium, Vibrio harveyi is the main pathogenic bacteria of H. otakii. In this study, the histopathology and label-free quantitative proteomics analysis were performed to reveal the changes of skin mucus proteins in H. otakii after infection with V. harveyi. The histopathological changes in the skin of H. otakii showed that when the bacteria were injected into the epithelial cells, it caused an increase in the number of mucous cells and a certain degree of damage and deformation in skin. Moreover, the quantitative proteomics analysis revealed a total of 364 differentially expressed proteins (DEPs), and these DEPs were found to be involved in environmental information processing, metabolism, infectious diseases: bacteria, replication and repair. More importantly, the enrichment analysis of the DEPs revealed that these different proteins were mainly targeted immune-related pathways. After infection of bacteria, the host's immune ability will be weakened, causing V. harveyi to enter the organism more easily, resulting in increased mucus in H. otakii, which will eventually lead to a decline in its physical function. These results provided an insight into a series of physiological changes after the bacterial infection of fish at the proteomic level and basic data for further exploration of the potential mechanism of skin mucus. Taken together, the results indicated more opportunities for the future designs and discoveries of effective antibacterial vaccines and antibacterial drugs for H. otakii.

Emerging functions and therapeutic targets of IL-38 in central nervous system diseases

Interleukin (IL)-38 is a newly discovered cytokine of the IL-1 family, which binds various receptors (i.e., IL-36R, IL-1 receptor accessory protein-like 1, and IL-1R1) in the central nervous system (CNS). The hallmark physiological function of IL-38 is competitive binding to IL-36R, as does the IL-36R antagonist. Emerging research has shown that IL-38 is abnormally expressed in the serum and brain tissue of patients with ischemic stroke (IS) and autism spectrum disorder (ASD), suggesting that IL-38 may play an important role in neurological diseases. Important advances include that IL-38 alleviates neuromyelitis optica disorder (NMOD) by inhibiting Th17 expression, improves IS by protecting against atherosclerosis via regulating immune cells and inflammation, and reduces IL-1β and CXCL8 release through inhibiting human microglial activity post-ASD. In contrast, IL-38 mRNA is markedly increased and is mainly expressed in phagocytes in spinal cord injury (SCI). IL-38 ablation attenuated SCI by reducing immune cell infiltration. However, the effect and underlying mechanism of IL-38 in CNS diseases remain inadequately characterized. In this review, we summarize the biological characteristics, pathophysiological role, and potential mechanisms of IL-38 in CNS diseases (e.g., NMOD, Alzheimer's disease, ASD, IS, TBI, and SCI), aiming to explore the therapeutic potential of IL-38 in the prevention and treatment of CNS diseases.

Whether full-length IL-38 acts as a promoter or inhibitor in activating rheumatoid arthritis fibroblast-like synoviocytes depends on IL-1β

AIM

IL-38 is a recently discovered inflammatory factor that belongs to the IL-1 family and has full-length and truncated forms. Clinical findings demonstrated that serum IL-38 levels in people with infectious and autoimmune diseases are significantly different from those in healthy people, but the form remains unclear. We are keenly interested in learning more about the regulatory role of full-length IL-38 in rheumatoid arthritis (RA), a classic autoimmune disease.

METHODS

RA-fibroblast-like synoviocytes (RA-FLS) were isolated from six RA patients and stimulated with full-length IL-38 to observe IL-6 and IL-8 secretion. Then, the migration and invasion functions of FLS were assessed. Next, the protein expressions of the MAPK, NF-κB, and JAK pathways were evaluated. In addition, we examined the effect of full-length IL-38 on FLS functions in the presence of IL-1β. The function of FLS affected by full-length IL-38 was also examined after blocking IL-1 and IL-36 receptors.

RESULTS

The functions of FLS were activated after the cells were stimulated with full-length IL-38. IL-6 and IL-8 levels increased with an increase in the full-length IL-38 concentration, and full-length IL-38 induced the acceleration of FLS migration and invasion functions. In addition, the levels of proteins in the MAPK signaling pathway increased after stimulation with full-length IL-38 and depended on its concentration. However, when the FLS were stimulated by IL-38 and IL-1β simultaneously, all experiments generated opposite results. Full-length IL-38 inhibited FLS function in the presence of IL-1β. IL-1R and IL-36R blockers terminated all effects of full-length IL-38 on RA-FLS.

CONCLUSION

Full-length IL-38 activates FLS functions and acts as a promoter in RA, whereas it inhibits FLS functions and acts as an inhibitor of RA in the presence of IL-1β. The function of full-length IL-38 can be blocked by IL-1Ra and IL-36Ra.

Coix seed oil alleviates synovial angiogenesis through suppressing HIF-1α/VEGF-A signaling pathways via SIRT1 in collagen-induced arthritis rats

BACKGROUND

Rheumatoid arthritis (RA) is a chronic autoimmune disorder characterized by symmetric arthritis. Coix Seed Oil (CSO) has been shown to reduce inflammation in collagen induced arthritis (CIA) rats. However, the effect of CSO on synovial angiogenesis in RA is unknown. In this study, we aimed to explore whether CSO could inhibit RA synovial angiogenesis and elucidate the underlying mechanisms.

METHODS

CIA rat models were established and subjected to different doses of CSO treatments for four weeks in vivo. Arthritis index, paw swelling, and weight were recorded to assess clinical symptoms. Hematoxylin and Eosin staining, Safarnin O fast green staining, Micro-CT, Immunohistochemical, and Immunofluorescence (IF) staining were performed to examined changes in synovial and joint tissues. The serum HIF-1α and VEGF-A levels were evaluated through enzyme-linked immunosorbent assay. Fibroblast-like synoviocytes (FLS) of rats was stimulated with tumor necrosis factor-α (TNF-α) for developing inflammatory model in vitro. Optimal concentrations of CSO and TNF-α for stimulation were measured through Cell Counting Kit-8 test. Wound healing and Transwell migration experiments were employed to determine FLS migratory ability. IF staining was performed to assess HIF-1α nuclear translocation in FLS. Protein levels of SIRT1, HIF-1α, VEGF-A, and CD31 were assessed through Western blot. The isolated aortic rings were induced with recombinant rat VEGF-A 165 (VEGF-A165) to observe the CSO inhibitory impact on angiogenesis ex vivo.

RESULTS

CSO attenuated the progression of arthritis in CIA rats, mitigated histopathological deterioration in synovial and joint tissues, significantly inhibited immature vessels labeled with CD31+/αSMA-, and reduced the micro-vessels in VEGF-A165 induced aortic rings. Moreover, it upregulated SIRT1 protein levels in CIA rats and TNF-α induced FLS, but decreased HIF-1α and VEGF-A protein levels. Furthermore, CSO inhibited the migration ability and HIF-1α nuclear translocation of TNF-α induced FLS. Finally, suppressing SIRT1 levels in TNF-α induced FLS enhanced their migration ability, HIF-1α nuclear translocation, and the protein levels of HIF-1α, VEGF-A, and CD31, whereas the inhibitory effect of CSO on TNF-α induced FLS was severely constrained.

CONCLUSIONS

This study indicates that CSO can alleviate synovial angiogenesis through suppressing HIF-1α/VEGF-A signaling pathways via SIRT1 in CIA rats.

The emerging role of IL-38 in diseases: A comprehensive review

INTRODUCTION

Interleukin-38 (IL-38) is a new type of anti-inflammatory cytokine, which is mainly expressed in the immunity-related organs and is involved in various diseases including cardiovascular and cerebrovascular diseases, lung diseases, viral infectious diseases and autoimmune diseases.

AIM

This review aims to detail the biological function, receptors and signaling of IL-38, which highlights its therapeutic potential in related diseases.

CONCLUSION

This article provides a comprehensive review of the association between interleukin-38 and related diseases, using interleukin-38 as a keyword and searching the relevant literature through Pubmed and Web of science up to July 2023.

Emerging role of hypoxia-inducible factor-1α in inflammatory autoimmune diseases: A comprehensive review

Hypoxia-inducible factor-1α (HIF-1α) is a primary metabolic sensor, and is expressed in different immune cells, such as macrophage, dendritic cell, neutrophil, T cell, and non-immune cells, for instance, synovial fibroblast, and islet β cell. HIF-1α signaling regulates cellular metabolism, triggering the release of inflammatory cytokines and inflammatory cells proliferation. It is known that microenvironment hypoxia, vascular proliferation, and impaired immunological balance are present in autoimmune diseases. To date, HIF-1α is recognized to be overexpressed in several inflammatory autoimmune diseases, such as systemic lupus erythematosus (SLE), rheumatoid arthritis, and function of HIF-1α is dysregulated in these diseases. In this review, we narrate the signaling pathway of HIF-1α and the possible immunopathological roles of HIF-1α in autoimmune diseases. The collected information will provide a theoretical basis for the familiarization and development of new clinical trials and treatment based on HIF-1α and inflammatory autoimmune disorders in the future.

The role of IL-38 in intestinal diseases - its potential as a therapeutic target

IL-38, an anti-inflammatory cytokine, is a key regulator of homeostasis in host immunity. Intestinal immunity plays a critical role in defence against pathogenic invasion, as it is the largest surface organ and the most common entry point for micro-organisms. Dysregulated IL-38 activity is observed in several autoimmune diseases including systemic lupus erythematosus and atherosclerosis. The protective role of IL-38 is well illustrated in experimental colitis models, showing significantly worse colitis in IL-38 deficient mice, compared to wildtype mice. Moreover, exogenous IL-38 has been shown to ameliorate experimental colitis. Surprisingly, upregulated IL-38 is detected in inflamed tissue from inflammatory bowel disease patients, consistent with increased circulating cytokine levels, demonstrating the complex nature of host immunity in vivo. However, colonic IL-38 is significantly reduced in malignant tissues from patients with colorectal cancer (CRC), compared to adjacent non-cancerous tissue. Additionally, IL-38 expression in CRC correlates with 5-year survival, tumour size and differentiation, suggesting IL-38 plays a protective role during the development of CRC. IL-38 is also an independent biomarker for the prognosis of CRC, offering useful information in the management of CRC. Taken together, these data demonstrate the role of IL-38 in the maintenance of normal intestinal mucosal homeostasis, but that dysregulation of IL-38 contributes to initiation of chronic inflammatory bowel disease (resulting from persistent local inflammation), and that IL-38 provides protection during the development of colorectal cancer. Such data provide useful information for the development of novel therapeutic targets in the management of intestinal diseases for more precise medicine.

Interleukin-38 in atherosclerosis

Chronic inflammation caused by immune cells and their mediators is a characteristic of atherosclerosis. Interleukin-38 (IL-38), a member of the IL-1 family, exerts multiple anti-inflammatory effects via specific ligand-receptor interactions. Upon recognizing a specific receptor, IL-38 restrains mitogen-activated protein kinase (MAPK), nuclear factor kappa B (NK-κB), or other inflammation-related signaling pathways in inflammatory disease. Further research has shown that IL-38 also displays anti-atherosclerotic effects and reduces the occurrence and risk of cardiovascular events. On the one hand, IL-38 can regulate innate and adaptive immunity to inhibit inflammation, reduce pathological neovascularization, and inhibit apoptosis. On the other hand, it can curb obesity, reduce hyperlipidemia, and restrain insulin resistance to reduce cardiovascular disease risk. Therefore, this article expounds on the vital function of IL-38 in the development of atherosclerosis to provide a theoretical basis for further in-depth studies of IL-38 and insights on the prophylaxis and treatment of atherosclerosis.

How to Model Rheumatoid Arthritis in Animals: From Rodents to Non-Human Primates

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease influenced by both genetic and environmental factors. At present, rodent models are primarily used to study the pathogenesis and treatment of RA. However, the genetic divergences between rodents and humans determine differences in the development of RA, which makes it necessary to explore the establishment of new models. Compared to rodents, non-human primates (NHPs) are much more closely related to humans in terms of the immune system, metabolic conditions, and genetic make-up. NHPs model provides a powerful tool to study the development of RA and potential complications, as well as preclinical studies in drug development. This review provides a brief overview of the RA animal models, emphasizes the replication methods, pros and cons, as well as evaluates the validity of the rodent and NHPs models.

Jintiange Capsule Alleviates Rheumatoid Arthritis and Reverses Changes of Serum Metabolic Profile in Collagen-Induced Arthritic Rats

Purpose

Jintiange capsule (JTG), an approved drug developed as a substitute for tiger bone (TB), has been clinically applied for osteoporosis therapy since 2003. The drug is composed of bionic TB powder, in which peptides and proteins are primarily enriched from other bone extracts. However, as a precious material of traditional Chinese medicine (TCM), TB has been mainly understood and used in TCM to relieve osteoporosis, rheumatoid arthritis and bone injury. Inspired by those, the purpose of this study was to investigate whether JTG also had an effect on relieving rheumatoid arthritis in collagen-induced arthritic (CIA) rats and explore potential mechanism from the perspective of serum metabolic profile changes.

Methods

JTG was analyzed using Nano LC-MS/MS and orally administered in CIA rats for 6 weeks. After administration, intervention effects of JTG on synovial inflammation, bone micro-architecture and bone metabolism were studied, and the impact of JTG on serum metabolic profiles in CIA rats was investigated by metabolomics.

Results

Nine bioactive peptides were identified in JTG. In animal treatments, JTG alleviated paw swelling (P < 0.01), arthritic severity (P < 0.01) and synovial tissue proliferation, as well as inflammatory cell infiltration of ankle joint, decreased bone loss, improved microstructure of bone in CIA rats by regulating bone absorption and formation, specifically increasing bone mineral density (BMD) (P < 0.05), bone volume fraction (BVF) (P < 0.05), trabecular number (Tb.N) (P < 0.05) and decreasing trabecular separation (Tb.Sp) (P < 0.05). Besides, serum IL-6 was down-regulated remarkably in CIA rats (P < 0.05). Furthermore, metabolomics analysis revealed that 32 metabolites were regulated significantly (P < 0.05) by comparison between CIA model and JTG in 360 mg/kg dose. The pathway analysis implied that JTG was involved in regulation of biosynthesis of phenylalanine.

Conclusion

JTG alleviates rheumatoid arthritis and reverses changes in serum metabolic profile in CIA rats.

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IL-1 family cytokines as drivers and inhibitors of trained immunity

Trained immunity is the long-term memory of innate immune cells, characterised by increased pro-inflammatory responses towards homo- and heterologous secondary stimuli. Interleukin (IL)-1 signalling plays an essential role in the induction of trained immunity, also called innate immune memory. As such, certain anti-inflammatory members of the IL-1 family of cytokines (IL-1F) which interfere with the inflammatory process have the potential to regulate the induction of a trained phenotype. The aim of this review is to provide an update on the role of IL-1F members in the context of trained immunity, emphasising the role of anti-inflammatory cytokines from the IL-1F to inhibit the induction of trained immunity, and touching upon their potential as therapeutics in IL-1-driven inflammatory disorders.

Immunobiological Properties and Clinical Applications of Interleukin-38 for Immune-Mediated Disorders: A Systematic Review Study

Exponential growth in the usage of "cytokines" (as seroimmunobiomarkers) has facilitated more accurate prognosis, early diagnosis, novel, and efficient immunotherapeutics. Numerous studies have reported immunopathophysiological and immunopathological processes of interleukin-38 (IL-38). Therefore, in this systematic review article, the authors aimed to present an updated comprehensive overview on the immunobiological mechanisms, diagnostic, and immune gene-based therapeutic potentials of IL-38. According to our inclusion and exclusion criteria, a total of 216 articles were collected from several search engines and databases from the January 2012 to July 2021 time interval by using six main keywords. Physiologic or pathologic microenvironments, optimal dosage, and involved receptors affect the functionalities of IL-38. Alterations in serum levels of IL-38 play a major role in the immunopathogenesis of a wide array of immune-mediated disorders. IL-38 shows anti-inflammatory activities by reduction or inhibition of pro-inflammatory cytokines, supporting the therapeutic aspects of IL-38 in inflammatory autoimmune diseases. According to the importance of pre-clinical studies, it seems that manipulation of the immune system by immunomodulatory properties of IL-38 can increase the accuracy of diagnosis, and decipher optimal clinical outcomes. To promote our knowledge, more collaboration is highly recommended among laboratory scientists, internal/infectious diseases specialists, oncologists, immunologists, diseases-specific biomarkers scientists, and basic medical researchers.

Regulation of Sirt1 on energy metabolism and immune response in rheumatoid arthritis

Rheumatoid arthritis (RA) is a systemic autoimmune disease. Synovial hyperplasia and persistent inflammation serve as its typical pathological manifestations, which ultimately lead to joint destruction and function loss. Both clinical observations and metabolomics studies have revealed the prevalence of metabolic disorders in RA. In inflammatory immune microenvironments, energy metabolism is profoundly changed. Increasingly evidences suggest that this abnormality is involved in the occurrence and development of RA-related inflammation. Unsurprisingly, many energy metabolism sensors have been confirmed with immunoregulatory properties. As a representative, silent information regulator type 1 (Sirt1) controls many aspects of immune cells, such as cell lifespan, polarization, and secretion by functioning as a transcriptional regulator. Because of the profound clinical implication, researches on Sirt1 in the regulation of energy metabolism and immune functions under RA conditions have gradually gained momentum. This signaling balances glycolysis, lipid metabolism and insulin secretion orchestrating with other metabolism sensors, and consequently affects immune milieu through a so-called metabolism-immune feedback mechanism. This article reviews the involvement of Sirt1 in RA by discussing its impacts on energy metabolism and immune functions, and specially highlights the potential of Sirt1-targeting anti-rheumatic regimens. It also provides a theoretical basis for clarifying the mystery about the high incidence of metabolic complications in RA patients and identifying new anti-rheumatic reagents.

The Pathological Mechanism and Potential Application of IL-38 in Autoimmune Diseases

Interleukin-38 (IL-38), a new cytokine of interleukin-1 family (IL-1F), is expressed in the human heart, kidney, skin, etc. Recently, new evidence indicated that IL-38 is involved in the process of different autoimmune diseases. Autoimmune diseases are a cluster of diseases accompanied with tissue damage caused by autoimmune reactions, including rheumatoid arthritis (RA), psoriasis, etc. This review summarized the links between IL-38 and autoimmune diseases, as well as the latest knowledge about the function and regulatory mechanism of IL-38 in autoimmune diseases. Especially, this review focused on the differentiation of immune cells and explore future prospects, such as the application of IL-38 in new technologies. Understanding the function of IL-38 is helpful to shed light on the progress of autoimmune diseases.