Abnormal Glucose Metabolism in Rheumatoid Arthritis

The impacts of obesity in rheumatoid arthritis and insights into therapeutic purinergic modulation

Rheumatoid Arthritis (RA) is an autoimmune condition responsible for the impairment of synovia and joints, endangering the functionality of individuals and contributing to mortality. Currently, obesity is increasing worldwide, and recent studies have suggested an association between such condition and RA. In this sense, obese individuals present a lower capacity for achieving remission and present more intense symptoms of the disease, demonstrating a link between both disorders. Different studies aim to understand the possible connection between the conditions; however, few is known in this sense. Therefore, knowing that obesity can alter the activity of multiple body systems, this work's objective is to evaluate the main modifications caused by obesity, which can be linked to the pathophysiology of RA, highlighting as relevant topics obesity's negative impact triggering systemic inflammation, intestinal dysbiosis, endocrine disbalances. Furthermore, the relationship between oxidative stress and obesity also deserves to be highlighted, considering the influence of reactive oxygen species (ROS) accumulation in RA exacerbation. Additionally, many of those characteristics influenced by obesity, along with the classic peculiarities of RA pathophysiology, can also be associated with purinergic signaling. Hence, this work suggests possible connections between the purinergic system and RA, proposing potential therapeutic targets against RA to be studied.

Metabolite-derived damage-associated molecular patterns in immunological diseases

Damage-associated molecular patterns (DAMPs) are typically derived from the endogenous elements of necrosis cells and can trigger inflammatory responses by activating DAMPs-sensing receptors on immune cells. Failure to clear DAMPs may lead to persistent inflammation, thereby contributing to the pathogenesis of immunological diseases. This review focuses on a newly recognized class of DAMPs derived from lipid, glucose, nucleotide, and amino acid metabolic pathways, which are then termed as metabolite-derived DAMPs. This review summarizes the reported molecular mechanisms of these metabolite-derived DAMPs in exacerbating inflammation responses, which may attribute to the pathology of certain types of immunological diseases. Additionally, this review also highlights both direct and indirect clinical interventions that have been explored to mitigate the pathological effects of these DAMPs. By summarizing our current understanding of metabolite-derived DAMPs, this review aims to inspire future thoughts and endeavors on targeted medicinal interventions and the development of therapies for immunological diseases.

The role and mechanism of TXNDC5 in disease progression

Thioredoxin domain containing protein-5 (TXNDC5), also known as endothelial protein-disulfide isomerase (Endo-PDI), is confined to the endoplasmic reticulum through the structural endoplasmic reticulum retention signal (KDEL), is a member of the PDI protein family and is highly expressed in the hypoxic state. TXNDC5 can regulate the rate of disulfide bond formation, isomerization and degradation of target proteins through its function as a protein disulfide isomerase (PDI), thereby altering protein conformation, activity and improving protein stability. Several studies have shown that there is a significant correlation between TXNDC5 gene polymorphisms and genetic susceptibility to inflammatory diseases such as rheumatoid, fibrosis and tumors. In this paper, we detail the expression characteristics of TXNDC5 in a variety of diseases, summarize the mechanisms by which TXNDC5 promotes malignant disease progression, and summarize potential therapeutic strategies to target TXNDC5 for disease treatment.

Ideal cardiovascular health metrics have better identification of arthritis

BACKGROUND

This study aimed to explore the association between ideal cardiovascular health metrics (ICVHM) and arthritis (AR), as well as the interactions of various indicators in ICVHM on AR in US adults.

METHODS

We involved 17,041 participants who were interviewed by NHANES from 2011 to 2018. AR included osteoarthritis or degenerative arthritis (OA), rheumatoid arthritis (RA), and psoriatic arthritis and other arthritis (Other AR). Logistic regression was applied to analyze the association between AR and ICVHM. Mixed graphical model (MGM) was used to explore the interaction between variables in ICVHM.

RESULTS

Higher ICVHM scores had a protective effect on AR. Compared to "≤1" score, the ORs of AR in participants with 2, 3, 4, and ≥5 were 0.586, 0.472, 0.259, and 0.130, respectively. Similar results were also found in different types of AR. ICVHM has a maximum area under the curve value of 0.765 and the interaction between blood pressure and total cholesterol was 0.43.

CONCLUSIONS

ICVHM correlates significantly with AR and is better at identifying AR than individual indicators. ICVHM can be better improved by controlling the indicators with stronger interactions. Our findings provide guidance for promoting health factors, which have important implications for identification and prevention of AR.

Prediction of Major Adverse Cardiovascular Events by Triglyceride Glucose Index in Predominantly Male Patients with Rheumatoid Arthritis

Background

Rheumatoid arthritis (RA) is a systemic and chronic autoimmune disease that is characterized by persistent joint inflammation. RA patients experience a considerably increased risk of cardiovascular-related morbidity and mortality. The current study investigated the association between triglyceride glucose (TyG) index and major adverse cardiovascular events (MACEs) in a predominantly male cohort of RA patients.

Methods

A total of 1613 RA patients (81.53% male) were selected from the Kailuan study. The TyG index was calculated as the logarithmic product of fasting blood triglyceride and fasting blood glucose divided by two. MACEs were defined as the composite of non-fatal myocardial infarctions and non-fatal strokes. Cox proportional hazards analysis was performed to study the association between the TyG index and MACEs.

Results

A total of 59 MACEs occurred during the median follow-up time of 5.32 years. Following adjustment for age and gender, analysis by multivariable Cox proportional hazards (model 1) showed that an elevated TyG index was associated with an increased risk of MACEs (quartile 2, hazard ratio (HR): 2.741, 95% confidence interval (CI): 1.220-6.157, p = 0.015; quartile 4, HR: 2.521, 95% CI: 1.074-5.917, p = 0.034). After adjustment for other variables, Cox proportional hazards analysis (model 2) showed that an elevated TyG index was independently associated with an increased risk of MACEs (quartile 2, HR: 2.348, 95% CI: 1.009-5.465, p = 0.048). In addition, subgroup analysis showed a higher TyG index was significantly linked to an increased risk of MACEs in patients aged more than 65 years (quartile 2, HR: 6.048, 95% CI: 1.311-27.908, p = 0.021; quartile 4, HR: 12.074, 95% CI: 1.438-101.358, p = 0.022).

Conclusions

The TyG index was associated with an increased risk of MACEs in a predominantly male cohort of RA patients. This index may be helpful for the prediction of MACEs in male patients with RA.

Clinical Trial Registration

Registration number in the Chinese clinical trial registry: ChiCTR-TNRC-11001489.

Precise Lipidomics Decipher Circulating Ceramide and Sphingomyelin Cycle Associated with the Progression of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a long-term autoimmune condition that causes joint and surrounding tissue inflammation. Lipid mediators are involved in inflammation and deterioration of the joints. Despite attempts to discover effective drug targets to intervene with lipid metabolism in the disease, progress has been limited. In this study, precise lipidomic technology was employed to quantify a broad range of serum ceramides and sphingomyelin (SM) in a large cohort, revealing an association between the accumulation of circulating ceramides and disturbed ceramide/SM cycles during the progression of RA. In our investigation, we discovered that eight ceramides exhibited a positive correlation with the activity of RA, thereby enhancing the accuracy of RA diagnosis, particularly in patients with serum antibody-negative RA. Furthermore, the enzyme SM phosphodiesterase 3 (SMPD3) was found to disrupt the circulating SM cycle and accelerate the progression of RA. The activity of SMPD3 can be inhibited by methotrexate, resulting in decreased metabolic conversion of SM to ceramide. These findings suggest that targeting the SM cycle may provide a new therapeutic option for RA.

Predictive model of diabetes mellitus in patients with idiopathic inflammatory myopathies

Objectives

Cardiovascular diseases are the common cause of death in patients with idiopathic inflammatory myopathies (IIMs). Diabetes mellitus was associated with higher cardiovascular mortality, but few studies focused on the risk of diabetes mellitus in IIMs patients. Our study is aimed at developing a predictive model of diabetes mellitus in IIMs patients.

Methods

A total of 354 patients were included in this study, of whom 35 (9.9%) were diagnosed as new-onset diabetes mellitus. The predictive nomogram was drawn based on the features selected by least absolute shrinkage and selection operator (LASSO) regression, univariate logistic regression, multivariable logistic regression, and clinical relationship. The discriminative capacity of the nomogram was assessed by C-index, calibration plot, and clinical usefulness. The predictive model was verified by the bootstrapping validation.

Results

The nomogram mainly included predictors such as age, gender, hypertension, uric acid, and serum creatinine. This predictive model demonstrated good discrimination and calibration in primary cohort (C-index=0.762, 95% CI: 0.677-0.847) and validation cohort (C-index=0.725). Decision curve analysis indicated that this predictive model was clinically useful.

Conclusions

Clinicians can assess the risk of diabetes mellitus in IIMs patients by using this prediction model, and preventive measures should be taken early for high-risk patients, ultimately reducing the adverse cardiovascular prognosis.

Physical Activity Influences Health-Related Quality of Life in Adults with Juvenile Idiopathic Arthritis

This cross-sectional study aimed to evaluate the impact of physical activity and physical fitness on the health-related quality of life (HQoL) of adult patients with Juvenile Idiopathic Arthritis (JIA). Fifty-nine JIA patients and sixty healthy individuals participated in this study. All individuals had the following evaluations performed: body composition (electrical bioimpedance), physical fitness (6 min walk test (6MWT)), physical activity level (International Physical Activity Questionnaire (IPAQ)), and HQoL (Quality of Life Questionnaire in relation to Health-Short Form (SF36)). Thirty-nine (66%) JIA patients were considered sedentary compared with 15 (25%) in the control group (p < 0.01). JIA patients had a lower HQoL compared with the control group in all variables studied (p < 0.05). JIA patients who were very physically active had better HQoL conditions in the categories of functional capacity (p = 0.001), limitations by physical aspects (p = 0.003), and emotional aspects (p = 0.002) compared with sedentary patients. JIA patients had more cardiovascular abnormalities and walked shorter distances compared with healthy controls in the 6MWT. In conclusion, we observed that HQoL was reduced in adults with JIA. A high percentage of JIA patients were sedentary with lower physical fitness, but physically active patients had a better HQoL than sedentary patients. The duration of physical activity, rather than intensity, influenced the mental aspects of HQoL.

Impact of hematopoietic stem cell transplantation in glycogen storage disease type Ib: A single-subject research design using 13C-glucose breath test

Background

Glycogen storage disease type Ib (GSD Ib) is an autosomal recessively inherited deficiency of the glucose-6-phosphate translocase (G6PT). Clinical features include a combination of a metabolic phenotype (fasting hypoglycemia, lactic acidosis, hepatomegaly) and a hematologic phenotype with neutropenia and neutrophil dysfunction. Dietary treatment involves provision of starches such as uncooked cornstarch (UCCS) and Glycosade® to provide prolonged enteral supply of glucose. Granulocyte colony-stimulating factor (G-CSF) is the treatment of choice for neutropenia. Because long-term stimulation of hematopoiesis with G-CSF causes serious complications such as splenomegaly, hypersplenism, and osteopenia; hematopoietic stem cell transplantation (HSCT) has been considered in some patients with GSD Ib to correct neutropenia and avoid G-CSF related adverse effects. Whether HSCT also has an effect on the metabolic phenotype and utilization of carbohydrate sources has not been determined.

Objective

Our objective was to measure the utilization of starch in a patient with GSD Ib before and after HSCT using the minimally invasive ¹³C-glucose breath test (¹³C-GBT).

Design

A case of GSD Ib (18y; female) underwent ¹³C-GBT four times: UCCS (pre-HSCT), UCCS (3, 5 months post-HSCT) and Glycosade® (6 months post-HSCT) with a dose of 80 g administered via nasogastric tube after a 4 h fast according to our patient's fasting tolerance. Breath samples were collected at baseline and every 30 min for 240 min. Rate of CO₂ production was measured at 120 min using indirect calorimetry. Finger-prick blood glucose was measured using a glucometer hourly to test hypoglycemia (glucose <4 mmol/L). Biochemical and clinical data were obtained from the medical records as a post-hoc chart review.

Results

UCCS utilization was significantly higher in GSD Ib pre-HSCT, which reduced and stabilized 5 months post-HSCT. UCCS and Glycosade® utilizations were low and not different at 5 and 6 months post-HSCT. Blood glucose concentrations were not significantly different at any time point.

Conclusions

Findings show that HSCT stabilized UCCS utilization, as reflected by lower and stable glucose oxidation. The results also illustrate the application of ¹³C-GBT to examine glucose metabolism in response to various carbohydrate sources after other treatment modalities like HSCT in GSD Ib.

The Involvement of Glucose and Lipid Metabolism Alteration in Rheumatoid Arthritis and Its Clinical Implication

Obviously, immune cells like T cells and macrophages play a major role in rheumatoid arthritis (RA). On one hand, the breakdown of immune homeostasis directly induces systemic inflammation; on the other hand, these cells initiate and perpetuate synovitis and tissue damages through the interaction with fibroblast-like synoviocytes (FLS). In recent years, the pathological link between metabolic disorders and immune imbalance has received increasing attention. High energy demand of immune cells leads to the accumulation of metabolic byproducts and inflammatory mediators. They act on various metabolism-sensitive signal pathways as well as relevant transcription factors, such as HIF-1α, and STATs. These molecular events will impact RA-related effectors like circulating immune cells and joint-resident cells in return, allowing the continuous progression of systemic inflammation, arthritic manifestations, and life-threatening complications. In other words, metabolic complications are secondary pathological factors for the progression of RA. Therefore, the status of energy metabolism may be an important indicator to evaluate RA severity, and in-depth explorations of the mechanisms underlying the mystery of how RA-related metabolic disorders develop will provide useful clues to further clarify the etiology of RA, and inspire the discovery of new anti-rheumatic targets. This article reviews the latest research progress on the interactions between immune and metabolism systems in the context of RA. Great importance is attached to the changes in certain pathways controlling both immune and metabolism functions during RA progression.

Construction of Rheumatoid Arthritis Risk Prediction and Medical Image Applications from Rheumatoid Factor Levels

Objective

To study the value of rheumatoid factor (RF) levels in the risk assessment of rheumatoid arthritis (RA) and combined hypertension and diabetes mellitus (DM) and construct RA risk prediction and medical image applications from rheumatoid factor levels.

Methods

A total of 249 RA patients who were treated in the First People's Hospital of Yunnan Province, and another 149 non-RA people were selected as the controls. The clinical data and the detection results of serum circulating RF_IgA, RF_IgG, and RF_IgM were collected. The receiver operating curve (ROC) and logistic regression were used to analyze the value of RF levels in the risk assessment of RA and combined hypertension and DM.

Results

After adjusting for age, BMI, smoking, drinking, hypertension, and diabetes, logistic regression analysis showed that RF_IgA positive, RF_IgG positive, and RF_IgM positive were all independent risk factors for RA (P < 0.05). The area under the curve (AUC) of circulating RF_IgA, RF_IgG, and RF_IgM levels in predicting RA was 0.79 (95% CI: 0.74-0.83, P < 0.001), 0.73 (95% CI: 0.68-0.78, P < 0.001), and 0.87 (95% CI: 0.84-0.91, P < 0.001), respectively. The AUC for predicting RA was 0.88 (95% CI: 0.85-0.92, P < 0.001) when combined detection of circulating RF_IgA, RF_IgG, and RF_IgM levels in peripheral blood. After adjusting for age and sex, logistic regression analysis showed that RF_IgA positive, RF_IgG positive, and RF_IgM positive were not independent risk factors for DM in RA patients (P > 0.05).

Conclusion

The levels of serum circulating RF_IgA, RF_IgG, and RF_IgM are valuable indicators for predicting the risk of RA, but not for the risk of RA complicated with hypertension and DM.

Glucose metabolism in systemic juvenile idiopathic arthritis

BACKGROUND

Systemic juvenile idiopathic arthritis (SJIA) is a chronic systemic inflammatory disease in children. Overproduction of inflammatory cytokines in SJIA resembles that in adult onset Still disease. Chronic inflammation causes insulin resistance and consequently leading to abnormal glucose metabolism. Adults with rheumatoid arthritis (RA) have increased risks of abnormal glucose metabolism and diabetes. To date, glucose metabolism in patients with SJIA has not been elucidated.

METHODS

Patients with SJIA aged 4-25 years were recruited. All patients underwent an oral glucose tolerance test (OGTT). Indices of insulin sensitivity [homeostasis model assessment for insulin resistance (HOMA-IR) and whole-body insulin sensitivity index (WBISI)] and β-cell function [insulinogenic index (IGI) and disposition index (DI)] were calculated. Obese children with normoglycemia who underwent the OGTT were served as a control group.

RESULTS

A total of 39 patients with SJIA, aged 4-25 years, median (IQR) BMI SDS was 0.1 (-0.5 to 1.7). Patients were divided into 2 groups, overweight/obese (OW/OB) (n = 11) and lean (n = 28). Only one obese patient had prediabetes and none had diabetes. In comparison with sex- and age-matched OW/OB controls (n = 33), OW/OB patients with SJIA had higher insulin resistance [median (IQR) HOMA-IR: 2.6 (2.1-3.3) vs 1.5 (0.8-2.0), p = 0.001], lower insulin sensitivity [median (IQR) WBISI: 3.7 (2.7-5.9) vs 5.4 (4.5-8.7), p = 0.024], and higher insulin secretion [median (IQR) IGI: 2.5 (2.0-3.5) vs 1.0 (0.8-1.9), p = 0.001]. In lean patients with SJIA, insulin sensitivity indices seemed to be comparable with those of lean controls.

CONCLUSIONS

Overweight/obese children with SJIA seemed to have increased insulin resistance and thus may have an increased risk for developing diabetes.

Physiological and Pathophysiological Roles of Metabolic Pathways for NET Formation and Other Neutrophil Functions

Neutrophils are the most numerous cells in the leukocyte population and essential for innate immunity. To limit their effector functions, neutrophils are able to modulate glycolysis and other cellular metabolic pathways. These metabolic pathways are essential not only for energy usage, but also for specialized effector actions, such as the production of reactive oxygen species (ROS), chemotaxis, phagocytosis, degranulation, and the formation of neutrophil extracellular traps (NETs). It has been demonstrated that activated viable neutrophils can produce NETs, which consists of a DNA scaffold able to bind granule proteins and microorganisms. The formation of NETs requires the availability of increased amounts of adenosine triphosphate (ATP) as it is an active cellular and therefore energy-dependent process. In this article, we discuss the glycolytic and other metabolic routes in association with neutrophil functions focusing on their role for building up NETs in the extracellular space. A better understanding of the requirements of metabolic pathways for neutrophil functions may lead to the discovery of molecular targets suitable to develop novel anti-infectious and/or anti-inflammatory drugs.

RHEUMATOID ARTHRITIS AS A PREDISPOSING FACTOR FOR INCREASED RISK OF DIABETES MELLITUS INCIDENCE

OBJECTIVE

The aim: Recent advances in diabetic mellitus (DM) care are focusing emphasis on comorbidities including rheumatoid arthritis (RA). The goal of this study is to determine the relationship between RA and diabetes as a risk factor.

PATIENTS AND METHODS

Materials and methods: Participants whose diagnosis of RA was confirmed by rheumatologists were recruited into a cross-sectional observational cohort using data from government and private clinics. Participants filled out detailed questionnaires. We included patients with DM and combined DM and RA who was diagnosed with both conditions by specialists between (October 2021 to April 2022) in Al Kut city, Iraq.

RESULTS

Results: Our finding shows no difference between the two groups DM and DM+RA in age, BMI, and smoking. However, the health status represented by hospitalization was more frequent in the DM+RA group. The inflammatory pathway in RA also increases the incidence of DM where we show an increase in the ESR in the DM+RA group. Interestingly Glycated hemoglobin (Hb a1c) indicator of DM was significantly increased in DM+RA compared to the DM group.

CONCLUSION

Conclusions: In conclusion, RA is linked to an increased chance of developing diabetes. This data backs up the theory that inflammatory pathways play a role in diabetes development.

Differential Metabolome in Rheumatoid Arthritis: a Brief Perspective

PURPOSE OF REVIEW

Rheumatoid arthritis (RA) is a chronic autoimmune, inflammatory disease of the synovium that affects the movable joints. It develops due to the infiltration and invasion of the synovial joints by immune cells. Metabolism is anabolic or catabolic chemical reactions occurring in a cell. The biochemical pathways in synovial and immune cells are altered affecting the downstream metabolite formation. Changes in the metabolite levels alter signaling cascades which further intensify the disease. Despite current knowledge of metabolomics, there remain certain features that need to be elucidated to correlate the differential metabolite levels with RA.

RECENT FINDINGS

Metabolite profiling can be used to find altered patterns of metabolites in RA. Glucose, lipid, amino acid, and estrogen metabolism are the key pathways that are altered and contribute to the aggravation of RA. The altered metabolic pathways involved in different cells in RA results in complex interactions between metabolites and biomacromolecules; thus, it generates autoantigens. Moreover, understanding the correlation between differential metabolites and disease severity might help reveal potential new biomarkers and therapeutic targets for RA pathogenesis. So, considering the multi-faceted role of altered metabolites in the pathogenesis of RA, metabolic pathways of different cells are needed to be studied for a better understanding of their functions in the disease and thus, improving the present therapeutic strategies.

Coupling of Co-expression Network Analysis and Machine Learning Validation Unearthed Potential Key Genes Involved in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an incurable disease that afflicts 0.5-1.0% of the global population though it is less threatening at its early stage. Therefore, improved diagnostic efficiency and prognostic outcome are critical for confronting RA. Although machine learning is considered a promising technique in clinical research, its potential in verifying the biological significance of gene was not fully exploited. The performance of a machine learning model depends greatly on the features used for model training; therefore, the effectiveness of prediction might reflect the quality of input features. In the present study, we used weighted gene co-expression network analysis (WGCNA) in conjunction with differentially expressed gene (DEG) analysis to select the key genes that were highly associated with RA phenotypes based on multiple microarray datasets of RA blood samples, after which they were used as features in machine learning model validation. A total of six machine learning models were used to validate the biological significance of the key genes based on gene expression, among which five models achieved good performances [area under curve (AUC) >0.85], suggesting that our currently identified key genes are biologically significant and highly representative of genes involved in RA. Combined with other biological interpretations including Gene Ontology (GO) analysis, protein-protein interaction (PPI) network analysis, as well as inference of immune cell composition, our current study might shed a light on the in-depth study of RA diagnosis and prognosis.

Novel positron emission tomography tracers for imaging of rheumatoid arthritis

Positron emission tomography (PET) is a nuclear imaging modality that relies on visualization of molecular targets in tissues, which is nowadays combined with a structural imaging modality such as computed tomography (CT) or Magnetic Resonance Imaging (MRI) and referred to as hybrid PET imaging. This technique allows to image specific immunological targets in rheumatoid arthritis (RA). Moreover, quantification of the PET signal enables highly sensitive monitoring of therapeutic effects on the molecular target. PET may also aid in stratification of the immuno-phenotype at baseline in order to develop personalized therapy. In this systematic review we will provide an overview of novel PET tracers, investigated in the context of RA, either pre-clinically, or clinically, that specifically visualize immune cells or stromal cells, as well as other factors and processes that contribute to pathology. The potential of these tracers in RA diagnosis, disease monitoring, and prediction of treatment outcome will be discussed. In addition, novel PET tracers established within the field of oncology that may be of use in RA will also be reviewed in order to expand the future opportunities of PET imaging in RA.

Sitagliptin and tofacitinib ameliorate adjuvant induced arthritis via modulating the cross talk between JAK/STAT and TLR-4/NF-κB signaling pathways

AIMS

Rheumatoid arthritis is an autoimmune systemic disorder causing pain, swelling, stiffness, and disability in various joints. This work was designed to evaluate the effect of sitagliptin and tofacitinib on Janus kinase (JAK)/signaling transducer and activator of transcription (STAT) and toll like receptor (TLR-4)/nuclear factor kappa B (NF-κB) signaling pathways in adjuvant induced arthritis in rats.

MATERIALS AND METHODS

Severity of arthritis was evaluated and serum was analyzed for inflammatory mediators. The mRNA and protein expression level of the most important members of the two signaling pathways were determined. Lipid profile, transaminases and renal function parameters were assessed.

KEY FINDINGS

Sitagliptin and tofacitinib significantly decreased the level of inflammatory parameters, the mRNA and protein expression level of the members of JAK/STAT and TLR-4/NF-κB pathways with more prominent effect of sitagliptin on TLR-4/NF-κB pathway and more expected obvious effect of tofacitinib on JAK/STAT pathway. The combination offered additional anti-inflammatory effect by inhibiting the cross talk between these pathways as inhibition of NF-κB activation decreased the serum level of IL-6 preventing the activation of STAT-3 in tibiotarsal tissues.

SIGNIFICANCE

The combination of tofacitinib and sitagliptin normalized serum lipids and blood glucose level which could offer protection against cardiovascular diseases and caused partial reversal of serum transaminases and creatinine levels which can protect against tofacitinb's related hepato and nephrotoxicity. We could conclude that the combination of Sitagliptin with tofacitinib can offer synergistic anti-inflammatory effect and more protective action against side effects of tofacitinib.

Anti-inflammatory effect of stevioside abates Freund's complete adjuvant (FCA)-induced adjuvant arthritis in rats

Adjuvant arthritis is a chronic, autoimmune and inflammatory disorder of the joints. The occurrence of disorder causes a severe damage to the connective tissue eventually leading to progressive physical disability and eventual death. The recent years of evidence suggests the anti-inflammatory properties of stevioside, a diterpene glycoside. However, the effect of stevioside against adjuvant arthritis, a chronic inflammatory disorder is not known. Hence, the present study was designed to study the effect of stevioside against Freund's complete adjuvant induced arthritis model in rats. The acute anti-inflammatory effect of stevioside also studied by employing carrageenan-induced paw oedema model in rats. The biochemical markers, haematological parameters, lipid peroxidation, myeloperoxidase activity, lipoxygenase activity, the levels of PGE2 and pro-inflammatory (TNF-α, IL-6 & IL-1β) and anti-inflammatory cytokine (IL-10) were analysed. The protein expression of NF-κB (p65) COX-2 and iNOS in paw tissues were estimated by western blotting. Stevioside treatment significantly ameliorates the adjuvant induced arthritic scoring, histological alterations, paw volume, elevation of biochemical (AST, ALT, ALP and glucose levels) and haematological (haemoglobin, differential and platelet count) parameters and restored the endogenous anti-oxidant (SOD, CAT, GSH and GST) activities. Treatment with stevioside also significantly prevented the adjuvant induced elevation of pro-inflammatory cytokines (TNF-α, IL-6 and IL-1β), pro-inflammatory protein expressions (iNOS, COX-2, NF-κB (p65) and pIκB/IκB ratio), prevented the increase in myeloperoxidase activity and significantly restored the anti-inflammatory (IL-10) cytokine level in paw tissues. Collectively, our findings suggest that stevioside may serve as anti-inflammatory agent and could serve as a potential adjunct therapeutic option in treating adjuvant arthritis.

Baihu Jia Guizhi Decoction Improves Rheumatoid Arthritis Inflammation by Regulating Succinate/SUCNR1 Metabolic Signaling Pathway

Rheumatoid arthritis (RA) is an autoimmune disease characterized by synovitis. Succinate is an inflammatory metabolic signal that exacerbates RA synovitis by activating succinate receptor 1 (SUCNR1) to amplify the release of IL-1β. Thus, inhibition of succinate activation of SUCRN1 could be an effective method to inhibit the inflammation of RA. Baihu Jia Guizhi decoction (BHGZ), which is composed of Gypsum Fibrosum, Anemarrhena asphodeloides Bge., Cinnamomum cassia Presl., Glycyrrhiza uralensis Fisch., and Oryza sativa L., is a Traditional Chinese Medicine (TCM) prescription used to treat RA in clinic. In addition, TCM believes that damp and heat environment is one of the causes of RA. In this study, we tested the role of damp and heat environments in exacerbating RA inflammation and the anti-inflammatory effect of BHGZ, based on succinate/SUCNR1/IL-1β pathway in the adjuvant arthritis (AA) model with damp and heat environment (AA + DHE). Results showed that paw swelling and synovial pathology were significantly increased in AA rats, and these results were aggravated by stimulation in damp and heat environment. BHGZ improved AA + DHE rats' paw swelling, synovial hyperplasia, and inflammatory cell infiltration and reduced IL-1β. In addition, AA rats significantly increased the expression of SUCNR1, and the stimulation of damp and heat environment not only increased the expression of SUCNR1 but also promoted the accumulation of succinate. BHGZ simultaneously reduced the concentration of succinate and the expression of SUCNR1. Finally, SDH activity was decreased in AA rats and AA + DHE rats, while BHGZ increased SDH activity and then reduced succinate concentration. Therefore, we prove that damp and heat environment deteriorated the inflammation of RA which is the activation of succinate/SUCNR1 pathway, while BHGZ regulates SDH activity to reduce the accumulation of succinate and inhibit the activation of SUCNR1 that is the underlying mechanism of its treatment of RA.

Tylophorine-based compounds are therapeutic in rheumatoid arthritis by targeting the caprin-1 ribonucleoprotein complex and inhibiting expression of associated c-Myc and HIF-1α

Interruption of the Warburg effect - the observation that un-stimulated macrophages reprogram their core metabolism from oxidative phosphorylation toward aerobic glycolysis to become pro-inflammatory M1 macrophages upon stimulation - is an emerging strategy for the treatment of cancer and anti-inflammatory diseases such as rheumatoid arthritis. We studied this process with view to the discovery of novel therapeutics, and found that tylophorine-based compounds targeted a ribonucleoprotein complex containing caprin-1 and mRNAs of c-Myc and HIF-1α in LPS/IFN-γ stimulated Raw264.7 cells, diminished the protein levels of c-Myc and HIF-1α, and consequently downregulated their targeted genes that are associated with the Warburg effect, as well as the pro-inflammatory iNOS and COX2. The tylophorine-based compound DBQ 33b significantly meliorated the severity and incidence of type II collagen-monoclonal antibody-induced rheumatoid arthritis and diminished gene expressions of c-Myc, HIF-1α, iNOS, COX2, TNFα, and IL-17A in vivo. Moreover, pharmacological inhibition of either c-Myc or HIF-1α exhibited similar effects as the tylophorine-based compound DBQ 33b, even though inhibition of c-Myc reversed the induction of iNOS and COX2 in LPS/IFN-γ stimulated Raw264.7 cells to a lesser degree. Therefore, simultaneous inhibition of both c-Myc and HIF-1α is efficacious for anti-inflammation in vitro and in vivo and merits further study.

Long Non-Coding RNAs Target Pathogenetically Relevant Genes and Pathways in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease driven by genetic, environmental and epigenetic factors. Long non-coding RNAs (LncRNAs) are a key component of the epigenetic mechanisms and are known to be involved in the development of autoimmune diseases. In this work we aimed to identify significantly differentially expressed LncRNAs (DE-LncRNAs) that are functionally connected to modulated genes strictly associated with RA. In total, 542,500 transcripts have been profiled in peripheral blood mononuclear cells (PBMCs) from four patients with early onset RA prior any treatment and four healthy donors using Clariom D arrays. Results were confirmed by real-time PCR in 20 patients and 20 controls. Six DE-LncRNAs target experimentally validated miRNAs able to regulate differentially expressed genes (DEGs) in RA; among them, only FTX, HNRNPU-AS1 and RP11-498C9.15 targeted a large number of DEGs. Most importantly, RP11-498C9.15 targeted the largest number of signalling pathways that were found to be enriched by the global amount of RA-DEGs and that have already been associated with RA and RA-synoviocytes. Moreover, RP11-498C9.15 targeted the most highly connected genes in the RA interactome, thus suggesting its involvement in crucial gene regulation. These results indicate that, by modulating both microRNAs and gene expression, RP11-498C9.15 may play a pivotal role in RA pathogenesis.

Ammonia exposure induced abnormal expression of cytokines and heat shock proteins via glucose metabolism disorders in chicken neutrophils

Ammonia (NH₃) is a highly irritant, alkaline gas. Atmospheric emission of NH₃ was recognized as an environmental challenge. As a global issue, the NH₃ emission survey with spatially detailed information demonstrated that the sources of atmospheric NH₃ include agriculture (livestock wastes, fertilizers) and some industrial activities. As an environmental pollution, excessive NH₃ exposure can induce many bird dysfunction. Neutrophils respond to multiple invading pathogens through different mechanisms. In order to investigate the effect of NH₃ exposure on broilers' neutrophil, 1-day-old broilers were treated with/without NH₃ for 28 days. We extracted neutrophils from peripheral blood of chicken with/without NH₃ exposure and subsequently stimulated with PMA. Changes of cytokines and inflammatory bodies, heat shock proteins (HSPs), and glucose metabolism of neutrophil were examined in both cases. We not only explored that the index associated with inflammation changed due to NH₃ exposure but also observed the status of neutrophils which was treated with PMA stimulation. After NH₃ exposure, IL-1β and IL-6 were significantly increased on broilers neutrophil. Inflammatory-related factors (NLRP3, ASC, and caspase-1) were significantly elevated. The mRNA expression of HSP70 and HSP90 was increased significantly. All glucose metabolism indicators were reduced. In summary, we concluded that NH₃ enhanced inflammation and disrupted glucose metabolism, and increased the expression of HSPs and inflammatory factors. In addition, the sensitivity of neutrophils to exogenous stimuli was diminished. This information can not only be used to evaluate the damage of NH₃-spiked neutrophils to chickens, but also provide clues for human health pathophysiology caused by excess NH₃, providing valuable information for NH₃ risk management.

An epidemiological analysis of osteoporotic characteristics in patients affected with rheumatoid arthritis in Kazakhstan

PURPOSE

We aimed to assess which of the major risk factors associated with rheumatoid arthritis (RA) severity are also associated with osteoporosis-related phenotypes (OP-RP) in the native population of Kazakhstan.

METHODS

Four hundred six RA patients (90.6% females) with 397 controls-unaffected first-degree relatives were recruited. Biochemical factors were recorded, and OP-RP were assessed using QCT scans and ultrasound densitometry (US) of the forearm to estimate cortical indices (CI), spongial bone mineral density (BMD_SPN), and US_T-scores.

RESULTS

In the RA affected female population, ~ 80% suffered from osteopenia or osteoporosis. All OP-RP were negatively correlated with age and female's sex, as expected, and thus accordingly adjusted, resulting in consistent, significantly [p = 0.016 (CI), p < 0.0001 (both BMD_SPN and US_T-scores)] lower OP-RP estimates in affected females. Using multiple regression analysis for OP-RP manifestations, only age and disease duration appeared consistently associated with all three studied phenotypes, while menopause status or years following the onset of menopause were also significant for BMD_SPN and US_T-scores. However, when disease duration was examined, we found that it was significantly dependent on morning stiffness, ESR, total cholesterol levels, weight, and menopause status, which explains 38.6% of the disease duration.

CONCLUSIONS

Approximately 80% of female RA patients suffer from osteoporosis or osteopenia in the study group, which appears from a young age. RA disease duration is the major risk factor for OP-RP deterioration, especially as assessed by BMD_SPNG, and US_T-scores. As a result, all OP-RP demonstrate significantly lower levels in comparison to sex- and age-matched unaffected individuals.

Prevalence of glucose intolerance in rheumatoid arthritis patients at a tertiary care centre in Haryana

AIMS

Recent studies have shown increasing prevalence of dysglycemia in rheumatoid arthritis (RA) patients. The present study was planned to study the prevalence of pre-diabetes and diabetes in RA patients from a tertiary care centre in Haryana, India.

METHODS

150 diagnosed cases of rheumatoid arthritis which were on follow up in Rheumatology clinic from last one year and equal number of age, sex matched controls were recruited for the study. FPG, 2h plasma glucose level after 75g oral glucose tolerance test and HbA1c were estimated in all the subjects. In RA patients c-reactive protein (CRP), erythrocyte sedimentation rate (ESR), rheumatoid factor (RF) and Anti-cyclic citrullinated (Anti CCP) antibodies were also measured and disease activity was assessed by using (DAS28 joint counts) and CDAI.

RESULTS

Patients with RA had statistically significant higher waist circumference, hip circumference and BMI as compared to control group. Prevalence of glucose intolerance in RA patients and control group was 14.67% and 6.67% respectively which was statistically significant (p=0.025). The prevalence of pre-diabetes was in RA group was not significant statistically. There was higher disease activity in glucose intolerant (GI) RA cases as compared to normal glucose tolerant (NGT) RA cases. The most commonly used drug combination among RA patients was MTX+HCQ+SAAZ (49 patients, 32.67%). Maximum glucose intolerance was observed in patients who were on Non-HCQ drug combinations.

CONCLUSIONS

There is elevated prevalence of glucose intolerance among RA patients that is related to high disease activity, visceral adiposity and drugs usage.

[What is your diagnosis? (Cutaneous leishmaniasis)]

Neutrophils are the most abundant, short lived, and terminally differentiated leukocytes with distinct tiers of arsenals to counter pathogens. Neutrophils were traditionally considered transcriptionally inactive cells, but recent researches in the field led to a paradigm shift in neutrophil biology and revealed subpopulation heterogeneity, and functions pivotal to immunity and inflammation. Furthermore, recent unfolding of metabolic plasticity in neutrophils has challenged the long-standing concept of their sole dependence on glycolytic pathway. Metabolic adaptations and distinct regulations have been identified which are critical for neutrophil differentiation and functions. The metabolic reprogramming of neutrophils by inflammatory mediators or during pathologies such as sepsis, diabetes, glucose-6-phosphate dehydrogenase deficiency, glycogen storage diseases (GSDs), systemic lupus erythematosus (SLE), rheumatoid arthritis, and cancer are now being explored. In this review, we discuss recent developments in understanding of the metabolic regulation, that may provide clues for better management and newer therapeutic opportunities for neutrophil centric immuno-deficiencies and inflammatory disorders.