What's new in our understanding of the role of adipokines in rheumatic diseases?

Adipokines as potential pharmacological targets for immune inflammatory rheumatic diseases: Focus on rheumatoid arthritis, osteoarthritis, and intervertebral disc degeneration

Adipokines are a heterogeneous group of signalling molecules secreted prevalently by adipose tissue. Initially considered as regulators of energy metabolism and appetite, adipokines have been recognized for their substantial involvement in musculoskeletal disorders, including osteoarthritis, rheumatoid arthritis, and many others. Understanding the role of adipokines in rheumatic inflammatory and autoimmune diseases, as well as in other musculoskeletal diseases such as intervertebral disc degeneration, is crucial for the development of novel therapeutic strategies. Targeting adipokines, or their signalling pathways, may offer new opportunities for the treatment and management of these conditions. By modulating adipokines levels or activity, it may be possible to regulate inflammation, to maintain bone health, and preserve muscle mass, thereby improving the outcomes and quality of life for individuals affected by musculoskeletal diseases. The aim of this review article is to update the reader on the multifaceted role of adipokines in the main rheumatic diseases such as osteoarthritis and rheumatoid arthritis and to unravel the complex interplay among adipokines, cartilage metabolism, bone remodelling and muscles, which will pave the way for innovative therapeutic intervention in the future. For completeness, the role of adipokines in intervertebral disc degeneration will be also addressed.

Associations of inflammatory and metabolic biomarkers with incident erosive hand osteoarthritis in the osteoarthritis initiative cohort

OBJECTIVE

Erosive hand osteoarthritis (eHOA) is a subtype of hand osteoarthritis (OA) that develops in finger joints with pre-existing OA and is differentiated by clinical characteristics (hand pain/disability, inflammation, and erosions) that suggest inflammatory or metabolic processes.

METHOD

This was a longitudinal nested case-cohort design among Osteoarthritis Initiative participants who had hand radiographs at baseline and 48-months, and biospecimens collected at baseline. We classified incident radiographic eHOA in individuals with ≥1 joint with Kellgren-Lawrence ≥2 and a central erosion present at 48-months but not at baseline. We used a random representative sample (n = 1282) for comparison. We measured serum biomarkers of inflammation, insulin resistance and dysglycemia, and adipokines using immunoassays and enzymatic colorimetric procedures, blinded to case status.

RESULTS

Eighty-six participants developed incident radiographic eHOA. In the multivariate analyses adjusted for age, gender, race, smoking, and body mass index, and after adjustment for multiple analyses, incident radiographic eHOA was associated with elevated levels of interleukin-7 (risk ratio (RR) per SD = 1.30 [95% confidence interval (CI) 1.09, 1.55] p trend 0.01).

CONCLUSION

This exploratory study suggests an association of elevated interleukin-7, an inflammatory cytokine, with incident eHOA, while other cytokines or biomarkers of metabolic inflammation were not associated. Interleukin-7 may mediate inflammation and tissue damage in susceptible osteoarthritic finger joints and participate in erosive progression.

Epidemiology of Sarcoidosis

Sarcoidosis is a systemic, granulomatous disease with variable presentation earning it the term "the great mimicker." The current epidemiology confirms that the disease occurs worldwide, affecting both sexes, and all races, ethnicities, and ages. To date, no causal exposure or agent has been identified. The organ systems most frequently affected by sarcoidosis are also those with greatest exposure to the natural world suggesting environmental and lifestyle contributions to the disease. These include particulate matter, microorganisms, nicotine, and obesity. In this article, we review the epidemiology of sarcoidosis and discuss these non-genetic risk factors in the hope of providing important insight into sarcoidosis and stimulating future research.

Comparing Metabolic Preconditioning and Diabetes As Risk Factors in Knee Arthroplasty Complications

BACKGROUND AND OBJECTIVES

Advanced osteoarthritis of the knee joint severely affects the patient's mobility, compounded by pre-existing comorbidities such as metabolic preconditioning (such as obesity, dyslipidemia, hyperuricemia, and insulin resistance syndrome) and both type I and type II diabetes. The success of total knee arthroplasty is influenced by knowledge and management of risk factors. The present study aims to evaluate differences in the evolution of risk factors such as obesity, injuries, and sedentary lifestyle, distinguishing those with metabolic preconditions and diabetes. The objectives of our study include (1) investigating the prevalence of obesity among patients, highlighting their proportion in the five categories of body weight; (2) analyzing statistically significant differences between research groups in terms of weight status and physical activity; (3) evaluating postoperative evolution based on the administration of nonsteroidal anti-inflammatory drugs (NSAIDs) and without NSAIDs (N-NSAIDs), with an emphasis on overweight patients and those with diabetes; and (4) examining changes in metabolic preconditioning and the incidence of postoperative injury depending on the administration of anti-inflammatory drugs.

MATERIALS AND METHODS

 A cohort involving 730 patients diagnosed with gonarthrosis was divided into two groups according to the administration of anti-inflammatory drugs in the first seven postoperative days: N-NSAIDs group (394 patients, 55.3%) and respectively NSAIDs group (319 patients, 44.7%). The prospective, observational study was conducted in terms of risk factors and complications that occurred upon treatment administration in relation to each type of intervention and implant used. The outcomes were assessed in terms of the influence on quality of life, the data being collected and interpreted for the entire cohort, and for each study year individually.

RESULTS

The results indicate that almost 69% of them were overweight, while only 31% had a normal weight. Significant differences in weight status were observed between research groups, highlighting the association between obesity and metabolic preconditions or diabetes. Physical activity was absent in a significant proportion, having a notable impact on postoperative evolution, especially in the group without metabolic precondition. Administration of anti-inflammatory drugs influenced postoperative outcomes, with significant differences in overweight and diabetic patients.

CONCLUSIONS

The findings suggest the need to manage body weight, promote physical activity, and personalize postoperative treatments, given the complex interactions between obesity, metabolic preconditions, and the administration of NSAIDs.

Impact of obesity and overweight on C-reactive protein concentrations and disease activity in rheumatoid arthritis: A systematic review and meta-analysis

AIM

This study aims to assess the association of obesity and CRP concentrations in adult patients with rheumatoid arthritis (RA), and its influence on measures of disease activity.

METHODS

A comprehensive search was performed using Scopus, Web of Science, MEDLINE, and EMBASE, from the time of their inception to November 2021. Observational studies that evaluated the association between CRP concentrations and obesity or overweight in patients with RA were considered eligible. Correlation coefficients were pooled using the inverse variance method, while effect sizes were pre-calculated for adjusted standardized regression coefficients (β).

RESULTS

A total of 10 studies, which comprised 4024 patients, were included in this systematic review. Individually, most studies report a significant association between CRP concentrations and a higher body mass index or other adiposity measures, but the statistical significance was not sustained when pooling their data together. Through the estimates provided in the present review, it is noted that CRP tends to be more elevated in female patients with RA that have a higher BMI. However, this association is not present in men.

CONCLUSION

CRP tends to be elevated in female patients with RA that have a higher BMI. Further research is required to assess this possible sex-related difference and to aid shared decision-making in order to avoid over-treatment and increased burden in patients with obesity and RA. PROSPERO registration number: CRD42022314580.

Effect of bariatric and metabolic surgery on rheumatoid arthritis outcomes: A systematic review

INTRODUCTION

Obesity is a growing and debilitating epidemic worldwide that is associated with an increased inflammation. It is often linked to rheumatic diseases and may impact negatively their natural history. The use of bariatric and metabolic surgery (BMS) has increased thanks to its positive effect on major comorbidities like diabetes type 2. This systematic review provides the most up-to-date published literature regarding the effect of BMS on outcomes in rheumatoid arthritis.

METHODS

This systematic review followed the preferred reporting items for systematic reviews guidelines. Original articles from Pubmed, Embase and Cochrane, published until June 16th 2023, and tackling the effect of BMS on disease outcomes in patients with RA were included.

RESULTS

Three studies met the inclusion criteria. They were published between 2015 and 2022. The total number of RA patients was 33193 and 6700 of them underwent BMS. Compared to non-surgical patients, weight loss after BMS was associated with lower disease activity outcomes at 12 months (p<0.05). Similarly, prior BMS in RA patients was significantly associated with reduced odds ratios for all the morbidities and in-hospital mortality compared with no prior BMS (36.5% vs 54.6%, OR = 0.45, 95% CI (0.42, 0.48), p< 0.001) and (0.4% vs 0.9%, OR = 0.41, 95% CI (0.27-0.61), p < 0.001) respectively.

CONCLUSION

To conclude, published data indicate that BMS seems a promising alternative in reducing RA disease activity as well as morbidity and mortality in patients with obesity.

Rheumatoid arthritis macrophages are primed for inflammation and display bioenergetic and functional alterations

OBJECTIVES

Myeloid cells with a monocyte/macrophage phenotype are present in large numbers in the RA joint, significantly contributing to disease; however, distinct macrophage functions have yet to be elucidated. This study investigates the metabolic activity of infiltrating polarized macrophages and their impact on pro-inflammatory responses in RA.

METHODS

CD14+ monocytes from RA and healthy control (HC) bloods were isolated and examined ex vivo or following differentiation into 'M1/M2' macrophages. Inflammatory responses and metabolic analysis ± specific inhibitors were quantified by RT-PCR, western blot, Seahorse XFe technology, phagocytosis assays and transmission electron microscopy along with RNA-sequencing (RNA-seq) transcriptomic analysis.

RESULTS

Circulating RA monocytes are hyper-inflammatory upon stimulation, with significantly higher expression of key cytokines compared with HC (P < 0.05) a phenotype which is maintained upon differentiation into mature ex vivo polarized macrophages. This induction in pro-inflammatory mechanisms is paralleled by cellular bioenergetic changes. RA macrophages are highly metabolic, with a robust boost in both oxidative phosphorylation and glycolysis in RA along with altered mitochondrial morphology compared with HC. RNA-seq analysis revealed divergent transcriptional variance between pro- and anti-inflammatory RA macrophages, revealing a role for STAT3 and NAMPT in driving macrophage activation states. STAT3 and NAMPT inhibition results in significant decrease in pro-inflammatory gene expression observed in RA macrophages. Interestingly, NAMPT inhibition specifically restores macrophage phagocytic function and results in reciprocal STAT3 inhibition, linking these two signalling pathways.

CONCLUSION

This study demonstrates a unique inflammatory and metabolic phenotype of RA monocyte-derived macrophages and identifies a key role for NAMPT and STAT3 signalling in regulating this phenotype.

Temporal Changes in Metabolic Syndrome Indices and Factors of Metabolic Syndrome Development in Patients With Rheumatic Disease: A Prospective Cohort Study

Patients with rheumatic disease have a high prevalence of metabolic syndrome. The purpose of this study was to investigate temporal changes in metabolic syndrome indices and to identify factors influencing metabolic syndrome development. A prospective cohort study design was adopted. The study participants were 68 outpatients with a rheumatic disease at an outpatient clinic of a university hospital. Data on demographics, health-related characteristics, steroid use, serum C-reactive protein levels, and metabolic syndrome indices were collected between December 2017 and March 2021. Temporal changes in body mass indices, serum triglyceride, and cholesterol levels were significant. Body mass indices, diastolic blood pressure, serum triglyceride, high-density lipoprotein, and fasting blood glucose levels at time of diagnosis were found to influence metabolic syndrome development. Temporal changes in serum triglyceride, cholesterol, and fasting blood glucose levels were significantly influenced by inflammatory status. The findings demonstrate the importance of controlling inflammatory activities in the context of inhibiting the progression of metabolic syndrome and rheumatic diseases.

Phytochemicals in the treatment of inflammation-associated diseases: the journey from preclinical trials to clinical practice

Advances in biomedical research have demonstrated that inflammation and its related diseases are the greatest threat to public health. Inflammatory action is the pathological response of the body towards the external stimuli such as infections, environmental factors, and autoimmune conditions to reduce tissue damage and improve patient comfort. However, when detrimental signal-transduction pathways are activated and inflammatory mediators are released over an extended period of time, the inflammatory process continues and a mild but persistent pro-inflammatory state may develop. Numerous degenerative disorders and chronic health issues including arthritis, diabetes, obesity, cancer, and cardiovascular diseases, among others, are associated with the emergence of a low-grade inflammatory state. Though, anti-inflammatory steroidal, as well as non-steroidal drugs, are extensively used against different inflammatory conditions, they show undesirable side effects upon long-term exposure, at times, leading to life-threatening consequences. Thus, drugs targeting chronic inflammation need to be developed to achieve better therapeutic management without or with a fewer side effects. Plants have been well known for their medicinal use for thousands of years due to their pharmacologically active phytochemicals belonging to diverse chemical classes with a number of these demonstrating potent anti-inflammatory activity. Some typical examples include colchicine (alkaloid), escin (triterpenoid saponin), capsaicin (methoxy phenol), bicyclol (lignan), borneol (monoterpene), and quercetin (flavonoid). These phytochemicals often act via regulating molecular mechanisms that synergize the anti-inflammatory pathways such as increased production of anti-inflammatory cytokines or interfere with the inflammatory pathways such as to reduce the production of pro-inflammatory cytokines and other modulators to improve the underlying pathological condition. This review describes the anti-inflammatory properties of a number of biologically active compounds derived from medicinal plants, and their mechanisms of pharmacological intervention to alleviate inflammation-associated diseases. The emphasis is given to information on anti-inflammatory phytochemicals that have been evaluated at the preclinical and clinical levels. Recent trends and gaps in the development of phytochemical-based anti-inflammatory drugs have also been included.

High Levels of Leptin and Adipsin Are Associated with Clinical Activity in Early Rheumatoid Arthritis Patients with Overweight and Periodontal Infection

Adipokines are associated with the pathogenesis of rheumatoid arthritis (RA) and are potential biomarkers of disease activity, periodontitis, and obesity. The aim of this was to establish the association between adipokine profile, RA disease activity, body mass index, and periodontal infection. This study evaluated 51 patients with early-RA and 51 controls including serum rheumatological markers, adipokine levels, detection of Porphyromonas gingivalis and serum anti-Porphyromonas gingivalis antibodies, clinical and periodontal measurements. Statistical analyses were run with SPSS® V26, with a logistic regression model to confirm associations. The results show high levels of leptin were more frequent in patients (p = 0.001) who simultaneously showed a higher frequency of Porphyromonas gingivalis (p = 0.004). Patients with concomitant presence of Porphyromonas gingivalis, high clinical activity score, and overweight were correlated with high levels of leptin (OR, 7.20; 95% CI, 2.68–19.33; p = 0.0001) and adipsin (OR, 2.69; 95% CI, 1.00–7.28; p = 0.005). The conclusion is that high levels of leptin and adipsin are associated with greater clinical activity in early-RA patients with overweight and periodontal infection, whereby overweight and Porphyromonas gingivalis may enhance RA activity. This may represent a pathological mechanism between these conditions, where adipokines seem to have a key role.

Adipokine profile in long-term juvenile dermatomyositis, and associations with adipose tissue distribution and cardiac function: a cross-sectional study

OBJECTIVES

In long-term juvenile dermatomyositis (JDM), altered adipose tissue distribution and subclinical cardiac dysfunction have been described. Our aims were to compare adipokine levels in patients with JDM after long-term disease with controls, and explore associations between adipokines and (1) adipose tissue distribution and (2) cardiac function.

METHODS

The study cohort included 59 patients with JDM (60% female, mean age 25.2 years, mean disease duration 16.9 years), and 59 age/sex-matched controls. Updated Pediatric Rheumatology International Trials Organization criteria for clinically inactive JDM were used to stratify patients into active (JDM-active) or inactive (JDM-inactive) disease groups. Lipodystrophy was clinically assessed in all patients. In all study participants, we measured adipose tissue distribution by dual-energy X-ray absorptiometry and cardiac function by echocardiography. Serum adipokines (adiponectin, apelin-12, lipocalin-2, leptin, visfatin and resistin) were analysed using ELISA.

RESULTS

Patients with JDM had higher leptin levels compared with controls (p≤0.01). In JDM-active, apelin-12 and visfatin were higher compared with JDM-inactive (p≤0.05). In JDM-total and JDM-active, lower adiponectin correlated with lipodystrophy and total fat mass. Also, systolic dysfunction correlated with: lower adiponectin in JDM-total, JDM-inactive and JDM-active, and with lower apelin-12 in JDM-total and JDM-active and resistin in JDM-active (all p≤0.05). Lower adiponectin correlated with diastolic dysfunction in JDM-total and JDM-active.

CONCLUSION

After long-term disease, leptin levels were unfavourably regulated in patients with JDM compared with controls, and apelin-12 and visfatin in JDM-active versus JDM-inactive. We found associations between adipokines and both adipose tissue distribution and cardiac systolic function in all patients with JDM, which was most prominent in patients with active disease.

β Boswellic Acid Blocks Articular Innate Immune Responses: An In Silico and In Vitro Approach to Traditional Medicine

Osteoarthritis (OA) is hallmarked as a silent progressive rheumatic disease of the whole joint. The accumulation of inflammatory and catabolic factors such as IL6, TNFα, and COX2 drives the OA pathophysiology into cartilage degradation, synovia inflammation, and bone destruction. There is no clinical available OA treatment. Although traditional ayurvedic medicine has been using Boswellia serrata extracts (BSE) as an antirheumatic treatment for a millennium, none of the BSE components have been clinically approved. Recently, β boswellic acid (BBA) has been shown to reduce in vivo OA-cartilage loss through an unknown mechanism. We used computational pharmacology, proteomics, transcriptomics, and metabolomics to present solid evidence of BBA therapeutic properties in mouse and primary human OA joint cells. Specifically, BBA binds to the innate immune receptor Toll-like Receptor 4 (TLR4) complex and inhibits both TLR4 and Interleukin 1 Receptor (IL1R) signaling in OA chondrocytes, osteoblasts, and synoviocytes. Moreover, BBA inhibition of TLR4/IL1R downregulated reactive oxygen species (ROS) synthesis and MAPK p38/NFκB, NLRP3, IFNαβ, TNF, and ECM-related pathways. Altogether, we present a solid bulk of evidence that BBA blocks OA innate immune responses and could be transferred into the clinic as an alimentary supplement or as a therapeutic tool after clinical trial evaluations.

Proteomics identifies novel biomarkers of synovial joint disease in a canine model of mucopolysaccharidosis I

Mucopolysaccharidosis I is a lysosomal storage disorder characterized by deficient alpha-L-iduronidase activity, leading to abnormal accumulation of glycosaminoglycans in cells and tissues. Synovial joint disease is prevalent and significantly reduces patient quality of life. There is a critical need for improved understanding of joint disease pathophysiology in MPS I, including specific biomarkers to predict and monitor joint disease progression, and response to treatment. The objective of this study was to leverage the naturally-occurring MPS I canine model and undertake an unbiased proteomic screen to identify systemic biomarkers predictive of local joint disease in MPS I. Synovial fluid and serum samples were collected from MPS I and healthy dogs at 12 months-of-age, and protein abundance characterized using liquid chromatography tandem mass spectrometry. Stifle joints were evaluated postmortem using magnetic resonance imaging (MRI) and histology. Proteomics identified 40 proteins for which abundance was significantly correlated between serum and synovial fluid, including markers of inflammatory joint disease and lysosomal dysfunction. Elevated expression of three biomarker candidates, matrix metalloproteinase 19, inter-alpha-trypsin inhibitor heavy-chain 3 and alpha-1-microglobulin, was confirmed in MPS I cartilage, and serum abundance of these molecules was found to correlate with MRI and histological degenerative grades. The candidate biomarkers identified have the potential to improve patient care by facilitating minimally-invasive, specific assessment of joint disease progression and response to therapeutic intervention.

Effect of metabolic surgery on immunosuppressive medication use in patients with rheumatic diseases

BACKGROUND

Obesity is an inflammatory condition associated with higher rheumatic disease (RD) incidence, increased disease activity, and functional impairment.

OBJECTIVE

We aimed to assess whether metabolic and bariatric surgery (MBS) decreases immunosuppressant use in patients with RD.

SETTING

Bariatric surgery academic centers of excellence.

METHODS

We conducted a retrospective review of MBS procedures in patients using immunosuppressants for RD between 2008 and 2020 at 2 academic institutions. Patient data were analyzed at 3-, 6-, 12-, and 24-month follow-up intervals. We examined paired differences in the number of preoperative medications relative to different postoperative follow-up periods using McNemar tests for the prednisone-only comparisons and paired t tests for all other comparisons.

RESULTS

We identified 53 patients with RD who underwent MBS (mean age = 53 years; mean follow-up = 19 months). Of these patients, 64% had Roux-en-Y gastric bypass, 30% sleeve gastrectomy, and 6% duodenal switch. Rheumatoid arthritis was the most common RD (42%), followed by psoriasis (19%) and lupus (11%). Mean percent total weight loss and change in body mass index were 31.3% and 15.9 kg/m², respectively, at 24-month follow-up. At 24 months, 10 patients (30%) stopped prednisone (P = .007), and 13 patients (33%) showed a reduction in immunosuppressant use (disease-modifying antirheumatic drugs or glucocorticoids) (P = .01). One patient started glucocorticoids postoperatively, and 2 patients had an increase in immunosuppressant use. At the last encounter, 5 patients were off immunosuppressants, and all medication classes, except biological disease-modifying antirheumatic drugs, showed significant reductions.

CONCLUSION

There is significant decrease in the use of immunosuppressant agents after MBS in patients with RD. Further studies are needed to confirm the correlation.

A new perspective: Fat tissue and adipokines in rheumatic heart valves

OBJECTIVE

To observe fat tissue and the expression of adipokines in rheumatic heart valves and explore the possible role of fat tissue and adipokines in the pathology of rheumatic heart disease (RHD).

METHODS

In this retrospective study, a total of 29 patients who received mitral valve replacement surgery were included. The study group consisted of 25 patients with RHD while the control group consisted of 4 patients with secondary mitral insufficiency caused by coronary heart disease (CAD). The clinical data of the patients including medical history, age, body mass index (BMI), fasting blood glucose (FBG), total triglycerides (TG), total cholesterol (TC), high-density lipoprotein-cholesterol (HDL-C), low-density lipoprotein-cholesterol (LDL-C), apolipoprotein(a) [apo(a)], apolipoprotein(b) [apo(b)] were collected and compared. Cardiac ultrasonography was used to assess valve conditions before surgery. The removed valves were collected. The hematoxylin-eosin (HE) staining, oil-red O staining, and Masson's trichrome staining were adopted to evaluate the histological changes in the mitral valve. Immunohistochemical (IMC) staining was performed to evaluate the expression of adiponectin, leptin, and chemerin.

RESULTS

There was no significant difference in general information and blood lipid levels between the two groups (all p > .05). Preoperative ultrasonography showed adipose tissue in the mitral valve of RHD patients. In the study group, rheumatic mitral valve samples showed thickening, adherence at the junction of the leaflets, calcification, and yellowish or fat mass by naked observation. The HE staining showed that there was calcification, inflammatory cell infiltration, fibrous tissue arranged disorder, and neovascularization. The oil-red O staining suggested fatty infiltration. Masson's trichrome staining suggested disorderly arrangement of collagen fiber and elastic fiber in rheumatic lesions, and the lesions were dominated by collagen fiber hyperplasia and less elastic fiber hyperplasia. The results of IMC indicated that chemerin was not expressed in valves of the control group. Most of the valve samples from the study group also did not show leptin and the leptin was seen in only a few rheumatic mitral valves with vascular hyperplasia. Adiponectin was not found in the valves of the study group and the control group.

CONCLUSION

Adipose tissue in the rheumatic mitral valve could be observed by ultrasound. The fat mass and adipokines existed in rheumatic mitral valves, the adipocytokine chemerin is involved in the progression of the pathology in RHD.

NAD+ metabolism in peripheral neuropathic pain

Nicotinamide adenine dinucleotide (NAD⁺) is an omnipresent metabolite that participates in redox reactions. Multiple NAD⁺-consuming enzymes are implicated in numerous biological processes, including transcription, signaling, and cell survival. Multiple pieces of evidence have demonstrated that NAD⁺-consuming enzymes, including poly(ADP-ribose) polymerases (PARPs), sirtuins (SIRTs), and sterile alpha and TIR motif-containing 1 (SARM1), play major roles in peripheral neuropathic pain of various etiologies. These NAD⁺ consumers primarily participate in peripheral neuropathic pain via mechanisms such as mitochondrial dysfunction, oxidative stress, and inflammation. Furthermore, NAD⁺ synthase and nicotinamide phosphoribosyltransferase (NAMPT) have recently been found to contribute to the regulation of pain. Here, we review the evidence indicating the involvement of NAD⁺ metabolism in the pathological mechanisms of peripheral neuropathic pain. Advanced understanding of the molecular and cellular mechanisms associated with NAD⁺ in peripheral neuropathic pain will facilitate the development of novel treatment options for diverse types of peripheral neuropathic pain.

Factors affecting pain and physical functions in patients with knee osteoarthritis: An observational study

Knee osteoarthritis (KOA) is more common as people age and have a higher body mass index (BMI). We must know the role of various factors in pain and physical functions in patients with KOA. Therefore, the present study sought to examine the factors associated with pain and physical functions in individuals with KOA. This cross-sectional observational study included patients with KOA (n = 125; 57 men, 68 women; mean age 52.9 years). Using the visual analogue scale and a reduced version of the Western Ontario McMaster Universities Osteoarthritis Index, pain severity and physical functions were assessed. Demographic factors such as age, BMI, sex, and Kellgren-Lawrence (K/L) radiographic grade of KOA were analyzed. Age (R = 0.263, P < .001), BMI (R = 0.379, P < .001), and K/L grade (R = 0.844, P < .001) were significantly associated with knee pain. Similarly, age (R = 0.310, P < .001), BMI (R = 0.374, P < .001), and K/L grade (R = 0.862, P < .001) were associated with physical functions. No significant association of sex with pain (R = 0.071, P = .440) and physical functions (R = 0.055, P = .545) was observed. Age, BMI, and K/L grade explained 71% and 74% of knee pain and physical functions, respectively. Age, BMI, and radiographic (K/L) grades were associated with pain and physical functions in patients with KOA. K/L grade was the most significant predictor of pain and physical functions in KOA.

Metabolic Abnormalities, Cardiovascular Disease, and Metabolic Syndrome in Adult Rheumatoid Arthritis Patients: Current Perspectives and Clinical Implications

AIM

Rheumatoid arthritis is a prevalent worldwide disease, associated with an increased risk of multiple metabolic abnormalities that generate a higher disease burden.

OBJECTIVE

To gather the available evidence on the epidemiology, pathophysiology, current perspectives, clinical implications and prognosis of metabolic abnormalities in patients with rheumatoid arthritis.

METHODS

This is a narrative literature review. Search was conducted in PubMed, OVID, and Taylor & Francis databases, using the following MeSH terms: "Arthritis Rheumatoid", "Metabolic Diseases", and "Metabolic Syndrome".

RESULTS

This study describes the main metabolic manifestations of rheumatoid arthritis. Research has recognized that rheumatoid arthritis and metabolic abnormalities share pathophysiological mechanisms with an additive effect that increases cardiovascular risk. In that context, appropriate antirheumatic treatment can also impact on cardiovascular risk.

CONCLUSION

There are metabolic abnormalities in rheumatoid arthritis patients that increase cardiovascular risk. Therefore, it is crucial to evaluate cardiovascular risk to provide appropriate comprehensive management to reduce morbidity and mortality in patients with this disease.

Relationship between polyautoimmunity and sarcopenic obesity in rheumatoid arthritis patients

OBJECTIVE

Sarcopenia is a major cause of morbidity in rheumatoid arthritis patients. Our purpose was to determine whether polyautoimmunity is associated with sarcopenia and alterations in whole body composition in patients with rheumatoid arthritis (RA).

METHODS

We performed a cross-sectional observational study of a series of cases of RA. All patients were recruited consecutively from a rheumatology clinic. Body composition by dual-energy x-ray absorptiometry (DEXA) was assessed. The variables of interest were polyautoimmunity (RA associated with other autoimmune diseases), sarcopenia, fat mass, and body mass index (BMI). Other variables included were clinical-analytical and inflammatory cytokines and adipokines. The relationship between sarcopenic obesity and the presence of polyautoimmunity was studied using multivariate analysis.

RESULTS

Of the 94 patients with RA included in the study, 15 (16%) had polyautoimmunity. A total of 23 patients with RA (24.5%) had sarcopenia, which was more prevalent in patients with polyautoimmunity than in patients without polyautoimmunity (46.7% vs 20.3%; p = .029). Sarcopenia was not associated with body fat content (p = .870) or with BMI (p = .998). The multivariate analysis showed the factors associated with polyautoimmunity in RA to be sarcopenia (odds ratio [95% CI], 4.80 [1.49-13.95]), BMI (1.18 [1.04-1.35]), and resistin (1.249 [1.01-1.53]).

CONCLUSION

Sarcopenia and obesity were more prevalent in patients with RA and polyautoimmunity. Resistin values were also higher in this group than in patients with RA without polyautoimmunity.

New insight into the role of lipid metabolism-related proteins in rheumatic heart valve disease

PURPOSE

The aim of this study was to determine the expression of lipid metabolism-related proteins in rheumatic heart valve disease (RHVD).

METHODS

This retrospective study involved a total of 20 cases of moderate or severe rheumatic mitral valve stenosis and 4 cases of mitral regurgitation due to secondary causes from September 2018 to September 2021. The patients enrolled included 12 males and 12 females who underwent surgical excision of the mitral valve at the cardiac surgery department of Hainan General Hospital. The samples of mitral valve were collected during surgery treatment as the study group, and mitral valves collected from patients with ischemic heart disease were allocated into the control group. Hematoxylin-eosin (HE), oil red staining and immunohistochemical (IHC) staining were conducted to compare the expression of lipid metabolism-related proteins (ATP-binding cassette transporter A1 and acyl-coenzyme A: cholesterol acyltransferase-1), and real-time polymerase chain reaction (RT-PCR) was applied to compare the mRNA levels of ABCA1, ACAT1, and the inflammatory cytokines TNF-α, IL-10, and MCP-1.

RESULTS

In general, the rheumatic mitral valve showed leaflet thickening along with border adhesions and visible yellow fats. Oil red O staining also revealed the abovementioned results as well as fat cells. Both ABCA1 and ACAT1 were expressed in the rheumatic mitral valve via IHC, whereas only ACAT1 showed a faint level of expression in the ischemic mitral valve with no expression of ABCA1. In addition, compared with the ischemic mitral valve, RT-PCT showed increased mRNA expression levels of ABCA1, ACAT1, and the inflammatory cytokines TNF-α, IL-10, and MCP-1 (P < 0.05). After dividing the RMs into two groups for RT-PCR, we found that the higher the expression of ABCA1 and ACAT1 was, the lower the relative expression of inflammatory factors.

CONCLUSION

This study showed that adipose tissue, adipose cells, and lipid transport-related proteins were expressed strongly in the rheumatic mitral valve, suggesting that adipose tissue formation might be one of the important pathways in the pathology of rheumatic heart disease. In addition, adipose tissue and adipocytes were also involved in the inflammatory process. These data provide new insight into pathological mechanisms in rheumatic heart disease.

Effects of One-Year Tofacitinib Therapy on Lipids and Adipokines in Association with Vascular Pathophysiology in Rheumatoid Arthritis

Background: Cardiovascular (CV) morbidity, mortality and metabolic syndrome are associated with rheumatoid arthritis (RA). A recent trial has suggested increased risk of major CV events (MACE) upon the Janus kinase (JAK) inhibitor tofacitinib compared with anti-tumor necrosis factor α (TNF-α) therapy. In our study, we evaluated lipids and other metabolic markers in relation to vascular function and clinical markers in RA patients undergoing one-year tofacitinib therapy. Patients and methods: Thirty RA patients treated with either 5 mg or 10 mg bid tofacitinib were included in a 12-month follow-up study. Various lipids, paraoxonase (PON1), myeloperoxidase (MPO), thrombospondin-1 (TSP-1) and adipokine levels, such as adiponectin, leptin, resistin, adipsin and chemerin were determined. In order to assess flow-mediated vasodilation (FMD), common carotid intima-media thickness (IMT) and arterial pulse-wave velocity (PWV) ultrasonography were performed. Assessments were carried out at baseline, and 6 and 12 months after initiating treatment. Results: One-year tofacitinib therapy significantly increased TC, HDL, LDL, APOA, APOB, leptin, adipsin and TSP-1, while significantly decreasing Lp(a), chemerin, PON1 and MPO levels. TG, lipid indices (TC/HDL and LDL/HDL), adiponectin and resistin showed no significant changes. Numerous associations were found between lipids, adipokines, clinical markers and IMT, FMD and PWV (p < 0.05). Regression analysis suggested, among others, association of BMI with CRP and PWV (p < 0.05). Adipokines variably correlated with age, BMI, CRP, CCP, FMD, IMT and PWV, while MPO, PON1 and TSP-1 variably correlated with age, disease duration, BMI, RF and PWV (p < 0.05). Conclusions: JAK inhibition by tofacitinib exerts balanced effects on lipids and other metabolic markers in RA. Various correlations may exist between metabolic, clinical parameters and vascular pathophysiology during tofacitinib treatment. Complex assessment of lipids, metabolic factors together with clinical parameters and vascular pathophysiology may be utilized in clinical practice to determine and monitor the CV status of patients in relation with clinical response to JAK inhibition.

Neutrophil Gelatinase-Associated Lipocalin as Potential Predictive Biomarker of Melanoma and Non-Melanoma Skin Cancers in Psoriatic Patients: A Pilot Study

Background: Studies have demonstrated a higher risk of nonmelanoma skin cancers (NMSC) and a modestly increased melanoma risk in patients with psoriasis. To date, no biomarkers predictive of evolution have been identified yet. Methods: The aim of this prospective case-control study was to investigate the potential role of neutrophil gelatinase-associated lipocalin (NGAL) as a predictive biomarker of skin cancers in psoriatic patients. Patients with a diagnosis of psoriasis were enrolled, as well as healthy subjects and patients with skin cancers as controls. Plasma protein expression of NGAL, metalloproteinases (MMP)-2, and MMP-9 was performed by an enzyme-linked immunosorbent assay (ELISA). In all the patients who developed skin cancer at follow-up, NGAL, MMP-2, and MMP-9 serum levels were dosed again. Results: Plasma NGAL levels were significantly higher in psoriatic patients with NMSC than without (182.3 ± 36.6 ng/mL vs. 139.9 ± 39.3 ng/mL) (p < 0.001). Plasma NGAL levels were significantly higher (p < 0.00001) in patients with psoriasis and NMSC than in patients with skin tumors without psoriasis (182.3 vs. 122.9). Patients with psoriasis who developed NMSC at follow-up showed increased plasma MMP-9 levels. Conclusion: NGAL seems to play a role in the pathogenesis of NMSC but not melanoma in patients with psoriasis.

Adipokine human Resistin promotes obesity-associated inflammatory intervertebral disc degeneration via pro-inflammatory cytokine cascade activation

Adipokine human Resistin (hResistin), is known to be associated with insulin resistance and secrete low-grade pro-inflammatory cytokines in obesity. Although studies on low-grade inflammation of adipokine hResistin are known, studies on the effects and mechanisms of intervertebral disc degeneration (IVDD) are still lacking. Thus, we investigated the adipokine hResistin with or without pro-inflammatory cytokine IL-1β in intervertebral disc (IVD) cells such as human annulus fibrosus (hAF) and nucleus pulposus (hNP). The protein expression changes in IL-1β, IL-6, IL-8, MMP-1, MMP-3, and MMP-13, induced by the combined-hResistin and IL-1β stimulation on hAF cells, was significantly greater than that of the same induced by mono-IL-1β stimulation. Similarly, in the case of the protein expression change of inflammatory mediators induced by the combined-hResistin and IL-1β stimulation on hNP cells was also significantly greater than that of the same induced by mono-IL-1β stimulation. These results improve understanding of hResistin on inflammatory IVDD but also with other obesity-related inflammatory diseases.

Application of extracellular vesicles derived from mesenchymal stem cells as potential therapeutic tools in autoimmune and rheumatic diseases

Mesenchymal stem cells (MSCs) have been proven to have superior potential to be used astherapeutic candidates in various disorders. Nevertheless, the clinical application of these cells have been restricted because of their tumorigenic properties. Increasing evidence has established that the valuable impacts of MSCs are mainly attributable to the paracrine factors including extracellular vesicles (EVs). EVs are nanosized double-layer phospholipid membrane vesicles contain various proteins, lipids and miRNAs which mediate cell-to-cell communications. Due to their inferior immunogenicity and tumorigenicity, as well as easier management, EVs have drawn attention as potential cell-free replacement therapy to MSCs. For that reason, herein, we reviewed the recent findings of researches on different MSC-EVs and their effectiveness in the treatment of several autoimmune and rheumatic diseases including multiple sclerosis, inflammatory bowel disease, rheumatoid arthritis, osteoarthritis, osteoporosis, and systemic lupus erythematosus as well as Sjogren's syndrome, systemic sclerosis and other autoimmune diseases.

Plebeian Sage (Salvia plebeia R. Br) Extract Ameliorates Inflammation and Cartilage Degradation in Surgically Induced Osteoarthritis Rats

Osteoarthritis (OA), the most prevalent articular disease with the clinical syndrome of joint pain accompanied by varying degrees of functional limitation, reduces the quality of elderly life. In this study, the effects of Plebeian sage extract (PS) on anti-inflammatory and anti-articular cartilage degradation activities were evaluated in rats with surgically induced OA. PS supplement for 12 weeks significantly decreased Mankin scores, including inflammatory cell numbers, and improved surface cartilage damage and mean femur and tibia articular cartilage (AC) thicknesses in OA rats. PS diminished IL-1β, IL-6, TNF-α, MMP-2, MMP-3, and MMP-9, as well as lipocalin-2 levels in serum or cartilage, which were increased due to OA. The results suggested that PS decreased joint inflammation and loss of articular cartilage by suppressing provocative responses and synovial tissue decimation in the OA model. Thus, PS may be used as a novel potential therapeutic regime for OA in the elderly.

Sparstolonin B suppresses free fatty acid palmitate-induced chondrocyte inflammation and mitigates post-traumatic arthritis in obese mice

Abnormal lipid metabolism, such as systemic increased free fatty acid, results in overproduction of pro‐inflammatory enzymes and cytokines, which is crucial in the development of obesity‐related osteoarthritis (OA). However, there are only a few drugs that target the lipotoxicity of OA. Recent researches have documented that the traditional Chinese medicine, Sparstolonin B (Ssn B), exerted anti‐inflammatory effects in various diseases, but not yet in OA. On the basis of this evidence, our works purposed to evaluate the effect of Ssn B on free fatty acid (FFA) palmitate (PA)‐stimulated human osteoarthritic chondrocytes and obesity‐associated mouse OA model. We found that Ssn B suppressed PA‐triggered inflammatory response and extracellular matrix catabolism in a concentration‐dependent approach. In vivo, Ssn B treatment inhibited cartilage degeneration and subchondral bone calcification caused by joint mechanical imbalance and alleviated metabolic inflammation in obesity. Mechanistically, co‐immunoprecipitine and molecular docking analysis showed that the formation of toll­like receptor 4 (TLR4)/myeloid differentiation protein‐2 (MD‐2) complex caused by PA was blocked by Ssn B. Subsequently, it leads to inactivation of PA‐caused myeloid differentiation factor 88 (MyD88)‐dependent nuclear factor‐kappaB (NF‐κB) cascade. Together, these findings demonstrated that Ssn B is a potential treatment agent for joint degenerative diseases in obese individuals.

Molecular Changes in the Adipose Tissue Induced by Rheumatoid Arthritis: Effects of Disease-Modifying Anti-Rheumatic Drugs

Disease severity, progression and response to therapy might be worse in obese rheumatoid arthritis (RA) patients, but paradoxically, obesity also might protect from radiographic joint damage. Thus, the intricate relationship between obesity and RA needs urgent clarification. The aim of this study was to assess the influence of obesity on the onset and development of RA and to determine whether arthritis could modify the adipose tissue biology and whether conventional Disease Modifying Anti-Rheumatic Drugs (cDMARDs) can modulate these alterations. Two strategies were followed: (1) clinical profiling of two cohorts of RA: non-obese and obese patients; and (2) mechanistic studies carried out in both a collagen-induced arthritis (CIA) in an obese mouse model and 3T3-L1 adipocytes treated with cDMARDs (leflunomide, methotrexate, and hydroxychloroquine). In our cohort of RA patients with low-moderate disease activity, the presence of obesity was not related to a higher activity of the disease; actually, disease activity score 28-erythrocyte sedimentation rate (DAS28-ESR) was reduced in the obese RA patients. However, the induction of arthritis promoted transcriptomic changes in the adipose tissue under obesity condition in the obese CIA model. Treatment with hydroxychloroquine reduced weight and insulin resistance, accompanied by beneficial metabolic effects in the adipose tissue. These molecular changes in adipose tissue were also observed after methotrexate administration. In sum, arthritis might affect directly the inflammatory burden and metabolic alterations associated with obesity in adipose tissue. Clinicians should be cautious measuring the activity of the disease in obesity and managing the best therapeutic options for the metabolic comorbidities of these patients, where the combination of hydroxychloroquine and methotrexate should be considered to improve adipose tissue dysfunction in obese RA.

1-MNA Ameliorates High Fat Diet-Induced Heart Injury by Upregulating Nrf2 Expression and Inhibiting NF-κB in vivo and in vitro

High levels of free fatty acids (FFA) are closely associated with obesity and the development of cardiovascular diseases. Recently, nicotinamide adenine dinucleotide (NAD) metabolism has emerged as a potential target for several modern diseases including diabetes. Herein, we explored the underlying mechanisms of NAD metabolism associated with the risk of cardiovascular disease. Our study found that nicotinamide N-methyltransferase (NNMT) mRNA levels were significantly increased in the hearts of FFA-bound-albumin-overloaded mice and in H9C2 cells treated with palmitic acid (PA). We studied the mechanisms underlining the anti-inflammatory and anti-oxidant activities of 1-methylnicotinamide (1-MNA), a metabolite of NNMT. We found a significantly higher level of reactive oxygen species, inflammation, apoptosis, and cell hypertrophy in PA-treated H9C2 cells and this effect was inhibited by 1-MNA treatment. in vivo, 1-MNA improved inflammation, apoptosis, and fibrosis damage in mice and this inhibition was associated with inhibited NF-κB activity. In conclusion, our study revealed that 1-MNA may prevent high fatty diet and PA-induced heart injury by regulating Nrf2 and NF-κB pathways.

Changes of Metabolic Biomarker Levels upon One-Year Anti-TNF-α Therapy in Rheumatoid Arthritis and Ankylosing Spondylitis: Associations with Vascular Pathophysiology

Background: Cardiovascular (CV) morbidity, mortality, and metabolic syndrome are associated with rheumatoid arthritis (RA) and ankylosing spondylitis (AS). Here, lipids and other metabolic markers in relation to vascular function and clinical markers were evaluated in RA and AS patients undergoing one-year anti-TNF therapy. Patients and methods: Fifty-three patients including 36 RA patients treated with either etanercept (ETN) or certolizumab pegol (CZP) and 17 AS patients treated with ETN were included in a 12-month follow-up study. Various lipids, paraoxonase (PON) and arylesterase (ARE) activities, myeloperoxidase (MPO) and adipokine levels were determined overtime. Ultrasonography was performed to determine flow-mediated vasodilation (FMD), common carotid intima-media thickness (ccIMT), and arterial pulse-wave velocity (PWV) in all patients. All assessments were performed at baseline and 6 and 12 months after treatment initiation. Results: Anti-TNF therapy decreased ARE activity, MPO, adiponectin, and chemerin levels after 12 months (p < 0.05). Lipids, PON activity, and leptin remained unchanged. Regression analyses suggested variable associations of IMT, PWV, and FMD with ARE, MPO, leptin, and lipids (p < 0.05). On the other hand, these metabolic parameters were significantly associated with disease duration, CV history, CRP, obesity, PWV, and IMT (p < 0.05). One-year anti-TNF treatment together with baseline leptin (p = 0.039) or CRP (p = 0.016) levels determined 12 months of lipid changes overtime. TNF inhibition together with baseline disease activity determined ARE activity changes (p = 0.046). Anti-TNF therapy and baseline chemerin levels determined IMT changes overtime (p = 0.003). Conclusions: Assessment of various metabolic parameters together with disease activity, CRP, and ultrasound-based techniques may exert additional value in determining CV burden and in monitoring the effects of biologics on preclinical vascular pathophysiology.

Ischemic Heart Disease and Rheumatoid Arthritis-Two Conditions, the Same Background

Rheumatoid arthritis (RA) is one of the most frequent inflammatory rheumatic diseases, having a considerably increased prevalence of mortality and morbidity due to cardiovascular disease (CVD). RA patients have an augmented risk for ischemic and non-ischemic heart disease. Increased cardiovascular (CV) risk is related to disease activity and chronic inflammation. Traditional risk factors and RA-related characteristics participate in vascular involvement, inducing subclinical changes in coronary microcirculation. RA is considered an independent risk factor for coronary artery disease (CAD). Endothelial dysfunction is a precocious marker of atherosclerosis (ATS). Pro-inflammatory cytokines (such as TNFα, IL-1, and IL-6) play an important role in synovial inflammation and ATS progression. Therefore, targeting inflammation is essential to controlling RA and preventing CVD. Present guidelines emphasize the importance of disease control, but studies show that RA- treatment has a different influence on CV risk. Based on the excessive risk for CV events in RA, permanent evaluation of CVD in these patients is critical. CVD risk calculators, designed for the general population, do not use RA-related predictive determinants; also, new scores that take into account RA-derived factors have restricted validity, with none of them encompassing imaging modalities or specific biomarkers involved in RA activity.

Association of the Adipokines Chemerin, Apelin, Vaspin and Omentin and Their Functional Genetic Variants with Rheumatoid Arthritis

Adipokines were shown to exert crucial roles in rheumatic diseases. This study aimed to assess the role of chemerin, apelin, vaspin, and omentin adipokines and their genetic variants rs17173608, rs2235306, rs2236242, and rs2274907, respectively, in rheumatoid arthritis (RA) pathogenesis in Egyptian patients. A total of 150 RA patients and 150 healthy individuals were recruited. Blood samples were collected and used for genotyping. Serum was separated and used for expression analysis by quantitative PCR, and various biochemical markers determination by ELISA. Serum protein levels of chemerin and vaspin, as well as their gene expression levels were higher, while those of apelin and omentin were lower in RA patients and were associated with most of RA clinical and laboratory characteristics. G allele of chemerin rs17173608, T allele of vaspin rs2236242, and T allele of omentin rs2274907 were more frequent in RA patients. Serum levels and gene expression levels of chemerin in GG genotype carriers and vaspin in TT genotype group were significantly higher, while those of omentin in TT genotype carriers were significantly lower than RA patients with other genotypes. There was no association between apelin rs2235306 and RA. Chemerin rs17173608, vaspin rs2236242, and omentin rs2274907 polymorphisms were associated with increased susceptibility to RA.

Serum chemerin levels: A potential biomarker of joint inflammation in women with rheumatoid arthritis

Background

Chemerin has a potential role in perpetuating inflammation in autoimmune diseases. Nevertheless, to date, there is no conclusive information on whether high chemerin levels increase the severity of rheumatoid arthritis (RA). Therefore, this study evaluated whether serum chemerin is a biomarker of disease activity in RA patients.

Methods

Study design: cross-sectional. The assessment included clinical and laboratory characteristics, body mass index (BMI) and fat mass. The severity of the disease activity was identified according to the DAS28-CRP index as follows: A) RA with a DAS28-CRP≤2.9 (remission/mild activity) and B) RA with a DAS28-CRP>2.9 (moderate/severe activity). Serum chemerin concentrations were measured by ELISA, and ≥103 ng/mL was considered a high level. Logistic regression analysis was applied to determine whether high chemerin levels were associated with disease activity in RA after adjusting for confounders. Multiple regression analysis was performed to identify variables associated with chemerin levels.

Results

Of 210 RA patients, 89 (42%) subjects had moderate/severe disease activity and had higher serum chemerin levels than patients with low disease activity or remission (86 ± 34 vs 73± 27; p = 0.003). Serum chemerin correlated with the number of swollen joints (r = 0.15; p = 0.03), DAS28-CRP (r = 0.22; p = 0.002), and C-reactive protein levels (r = 0.14; p = 0.04), but no correlation was observed with BMI and fat mass. In the adjusted logistic regression analysis, high chemerin levels (≥103 ng/mL) were associated with an increased risk of moderate/severe disease activity (OR: 2.76, 95% CI 1.35–5.62; p = 0.005). In the multiple regression analysis, after adjusting for potential confounders, serum chemerin levels were associated with higher DAS28-CRP (p = 0.002).

Conclusions

Higher chemerin levels increased the risk of moderate and severe disease activity in RA. These results support the role of chemerin as a marker of inflammation in RA. Follow-up studies will identify if maintaining low chemerin levels can be used as a therapeutic target.

Emerging role of leptin in joint inflammation and destruction

Rheumatoid arthritis (RA) is an autoimmune disease characterized by tumor-like hyperplasia and inflammation of the synovium, which causes synovial cell invasion into the bone and cartilage. In RA pathogenesis, various molecules in effector cells (i.e., immune cells and mesenchymal cells) are dysregulated by genetic and environmental factors. Consistent with the early stages of RA, these pathogenic cells cooperate and activate each other directly by cell-to-cell contact or indirectly via humoral factors. Recently, growing evidence has revealed essential role of adipokines, which are multifunctional signal transduction molecules, in the immune system. In this review, we summarize the current understanding of the cross-talk between leptin, one of the most well-known and best-characterized adipokines, and osteoimmunology. Furthermore, we discuss the contribution of leptin to the pathogenesis of RA and its potential mechanisms.

A Metalloproteinase Induces an Inflammatory Response in Preadipocytes with the Activation of COX Signalling Pathways and Participation of Endogenous Phospholipases A2

Matrix metalloproteinases (MMPs) are proteolytic enzymes that have been associated with the pathogenesis of inflammatory diseases and obesity. Adipose tissue in turn is an active endocrine organ capable of secreting a range of proinflammatory mediators with autocrine and paracrine properties, which contribute to the inflammation of adipose tissue and adjacent tissues. However, the potential inflammatory effects of MMPs in adipose tissue cells are still unknown. This study investigates the effects of BmooMPα-I, a single-domain snake venom metalloproteinase (SVMP), in activating an inflammatory response by 3T3-L1 preadipocytes in culture, focusing on prostaglandins (PGs), cytokines, and adipocytokines biosynthesis and mechanisms involved in prostaglandin E₂ (PGE₂) release. The results show that BmooMPα-I induced the release of PGE₂, prostaglandin I₂ (PGI₂), monocyte chemoattractant protein-1 (MCP-1), and adiponectin by preadipocytes. BmooMPα-I-induced PGE₂ biosynthesis was dependent on group-IIA-secreted phospholipase A₂ (sPLA₂-IIA), cytosolic phospholipase A₂-α (cPLA₂-α), and cyclooxygenase (COX)-1 and -2 pathways. Moreover, BmooMPα-I upregulated COX-2 protein expression but not microsomal prostaglandin E synthase-1 (mPGES-1) expression. In addition, we demonstrate that the enzymatic activity of BmooMPα-I is essential for the activation of prostanoid synthesis pathways in preadipocytes. These data highlight preadipocytes as important targets for metalloproteinases and provide new insights into the contribution of these enzymes to the inflammation of adipose tissue and tissues adjacent to it.

Treadmill running induces remodeling of the infrapatellar fat pad in an intensity-dependent manner

OBJECTIVE

To investigate the response of the infrapatellar fat pad (IFP) to running at different intensities and further explore the underlying mechanisms of these responses under different running-induced loadings.

METHODS

Animals were randomly assigned into the sedentary (SED), low-intensity running (LIR), medium-intensity running (MIR), and high-intensity running (HIR) groups. The rats in the LIR, MIR, and HIR groups were subjected to an 8-week treadmill running protocol. In each group, the IFP was examined at the baseline and at the 8th week to perform histomorphology, immunohistochemistry, and mRNA expression analyses.

RESULTS

Compared with LIR and MIR, HIR for 8 weeks led to a substantial increase in the surface cellularity (1.67 ± 1.15), fibrosis (1.29 ± 0.36), and vascularity (33.31 ± 8.43) of the IFP but did not increase IFP inflammation or M1 macrophage polarization. Low-to-medium-intensity running resulted in unchanged or decreased fibrosis, vascularity, and surface cellularity in the IFP compared to those of the SED group. Furthermore, serum leptin and visfatin levels were significantly lower in the LIR and MIR groups than in the SED group or the HIR group (P < 0.05).

CONCLUSION

The effect of running on IFP remodeling was intensity dependent. In contrast to LIR and MIR, HIR increased the fibrosis and vascularity of the IFP. HIR-induced IFP fibrosis was probably due to mechanical stress, rather than pathological proinflammatory M1/M2 polarization.

The pleiotropic roles of leptin in metabolism, immunity, and cancer

The discovery of the archetypal adipocytokine leptin and how it regulates energy homeostasis have represented breakthroughs in our understanding of the endocrine function of the adipose tissue and the biological determinants of human obesity. Investigations on leptin have also been instrumental in identifying physio-pathological connections between metabolic regulation and multiple immunological functions. For example, the description of the promoting activities of leptin on inflammation and cell proliferation have recognized the detrimental effects of leptin in connecting dysmetabolic conditions with cancer and with onset and/or progression of autoimmune disease. Here we review the multiple biological functions and complex framework of operations of leptin, discussing why and how the pleiotropic activities of this adipocytokine still pose major hurdles in the development of effective leptin-based therapeutic opportunities for different clinical conditions.

Rheumatoid arthritis in Colombia: a clinical profile and prevalence from a national registry

BACKGROUND

There is a need to describe the demographic and clinical characteristics of people diagnosed with rheumatoid arthritis who are attended within the Colombian health system. This characterization allows prioritizing populations with specific risks, programming the use of health services, and planning the costs necessary to guarantee equitable care.

OBJECTIVE

To assess the demographic and clinical characteristics of a cohort of patients with rheumatoid arthritis using national data collected by the High-Cost Disease Fund (CAC in Spanish).

METHODS

A cross-sectional study from a secondary source. Data was gathered from a national administrative registry. A descriptive analysis was performed on sociodemographic and clinical characteristics. Age-standardized prevalence was estimated at national level and by geographical regions. Remission rates were also estimated for Colombian departments and regions.

RESULTS

By 2019, 81,386 patients with rheumatoid arthritis were reported in Colombia. The relation female-male was 5.2:1. The median age was 59 years (IQR: 50-67). Prevalence was higher in people aged 50-69 years. The most frequent comorbidities were high blood pressure (31.15%) and osteoporosis (19.46%). Age-standardized prevalence of rheumatoid arthritis was 0.24 per 100 population (95% CI: 0.23-0.24). In cases with complete information, 57.57% of departments had remission rates up to 30%.

CONCLUSION

Rheumatoid arthritis in Colombia was more frequent in females aged ≥50 year. Age-standardized prevalence was lower than reported by other studies performed in Colombia but similar to the estimated internationally for the country. Key Points • More than 80,000 rheumatoid arthritis patients were reported to this national registry in Colombia in 2019, finding an age-standardized prevalence of 0.24 per 100 population. • Hypertension was the most common comorbidity reported in people with rheumatoid arthritis. This finding is similar to the reports by similar studies such as the COMORA. • A major strength of this study is the large sample size since data come from a nationwide registry of people with rheumatoid arthritis, supported by the National Ministry of Health. Additionally, this registry has a rigorous data monitoring process that guarantees the internal validity of data and provides valuable information for decision-making based on local evidence. • Prevalence of rheumatoid arthritis was higher in females between 50 and 65 years. Age-standardized prevalence was lower than previously reported in Colombia, but similar to the world estimations.

Obesity Progression Between Young Adulthood and Midlife and Incident Arthritis: A Retrospective Cohort Study of US Adults

OBJECTIVE

To examine the association between weight change from young adulthood to midlife and the risk of incident arthritis.

METHODS

Using data from the National Health and Nutrition Examination Survey, we categorized participants into weight-change categories based on their recalled weight during young adulthood and midlife. We estimated the association of weight change and developing an arthritis condition over 10 years using adjusted Cox models. Findings were extrapolated to the US population to determine the proportion of incident arthritis cases that could be averted if the entire population maintained a normal body mass index (BMI) in young adulthood and midlife.

RESULTS

Among our sample of adults who were ages 40-69 years at their midlife weight measure (n = 13,669), 3,603 developed an arthritis condition. Compared with adults who maintained a normal-normal BMI, the normal-overweight, normal-obese, overweight-obese, and obese-obese groups had a significantly elevated risk of incident arthritis conditions. The obese-overweight group had a lower risk of incident arthritis conditions compared with the obese-obese group and a comparable risk to the overweight-overweight group. Nearly one-fourth of incident arthritis cases, corresponding to 2.7 million individuals, would have been averted under the hypothetical scenario where all individuals maintained normal weight from young adulthood to midlife.

CONCLUSION

Weight loss from young adulthood to midlife was associated with a substantially reduced risk of developing an arthritis condition. We found no evidence of residual risk from having been heavier earlier in life. Our findings highlight the critical need to expand obesity treatment and prevention to achieve meaningful reductions in the burden of arthritis.

Visfatin: An emerging adipocytokine bridging the gap in the evolution of cardiovascular diseases

Visfatin/nicotinamide phosphoribosyltransferase (NAMPT) is an adipokine expressed predominately in visceral fat tissues. High circulating levels of visfatin/NAMPT have been implicated in vascular remodeling, vascular inflammation, and atherosclerosis, all of which pose increased risks of cardiovascular events. In this context, increased levels of visfatin have been correlated with several upregulated pro-inflammatory mediators, such as IL-1, IL-1Ra, IL-6, IL-8, and TNF-α. Furthermore, visfatin is associated with leukocyte recruitment by endothelial cells and the production of adhesion molecules such as vascular cell adhesion molecule 1, intercellular cell adhesion molecule 1, and E-selectin, which are well known to mediate the progression of atherosclerosis. Moreover, diverse angiogenic factors have been found to mediate visfatin-induced angiogenesis. These include matrix metalloproteinases, vascular endothelial growth factor, monocyte chemoattractant protein 1, and fibroblast growth factor 2. This review aims to provide a comprehensive overview of the pro-inflammatory and angiogenic actions of visfatin, with a focus on the pertinent signaling pathways whose dysregulation contributes to the pathogenesis of atherosclerosis. Most importantly, some hypotheses regarding the integration of the aforementioned factors with the plausible atherogenic effect of visfatin are put forth for consideration in future studies. The pharmacotherapeutic potential of modulating visfatin's roles could be important in the management of cardiovascular disease, which continues to be the leading cause of death worldwide.

Therapeutic Applications of Type 2 Diabetes Mellitus Drug Metformin in Patients with Osteoarthritis

Type 2 diabetes mellitus (T2DM) and osteoarthritis (OA) are common chronic diseases that frequently co-exist. The link between OA and T2DM is attributed to common risk factors, including age and obesity. Several reports suggest that hyperglycemia and accumulated advanced glycosylation end-products might regulate cartilage homeostasis and contribute to the development and progression of OA. Metformin is used widely as the first-line treatment for T2DM. The drug acts by regulating glucose levels and improving insulin sensitivity. The anti-diabetic effects of metformin are mediated mainly via activation of adenosine monophosphate (AMP)-activated protein kinase (AMPK), which is an energy sensing enzyme activated directly by an increase in the AMP/ATP ratio under conditions of metabolic stress. Dysregulation of AMPK is strongly associated with development of T2DM and metabolic syndrome. In this review, we discuss common risk factors, the association between OA and T2DM, and the role of AMPK. We also address the adaptive use of metformin, a known AMPK activator, as a new drug for treatment of patients with OA and T2DM.

The P2X7 Receptor in Osteoarthritis

Osteoarthritis (OA) is the most common joint disease. With the increasing aging population, the associated socio-economic costs are also increasing. Analgesia and surgery are the primary treatment options in late-stage OA, with drug treatment only possible in early prevention to improve patients' quality of life. The most important structural component of the joint is cartilage, consisting solely of chondrocytes. Instability in chondrocyte balance results in phenotypic changes and cell death. Therefore, cartilage degradation is a direct consequence of chondrocyte imbalance, resulting in the degradation of the extracellular matrix and the release of pro-inflammatory factors. These factors affect the occurrence and development of OA. The P2X7 receptor (P2X7R) belongs to the purinergic receptor family and is a non-selective cation channel gated by adenosine triphosphate. It mediates Na⁺, Ca²⁺ influx, and K⁺ efflux, participates in several inflammatory reactions, and plays an important role in the different mechanisms of cell death. However, the relationship between P2X7R-mediated cell death and the progression of OA requires investigation. In this review, we correlate potential links between P2X7R, cartilage degradation, and inflammatory factor release in OA. We specifically focus on inflammation, apoptosis, pyroptosis, and autophagy. Lastly, we discuss the therapeutic potential of P2X7R as a potential drug target for OA.

Effects of intragastric balloon on obesity in obese Korean women for 6 months post removal

BACKGROUND/OBJECTIVES

The prevalence of morbid obesity in Korean women has consistently been increasing, while the overall prevalence rate of obesity in Korean women seems to be stable. In addition to bariatric surgery, intragastric balloons (IGBs), as a nonsurgical therapy, have been reported to be effective in weight loss. However, the beneficial effects of IGB in Korean women with obesity have not been fully investigated. The aim of this study was to evaluate the changes in fat mass in Korean women with obesity who had undergone IGB treatment for 6 mon.

SUBJECTS/METHODS

Seventy-four women with obesity (body mass index [BMI] ≥ 25.0 kg/m²) were recruited. Clinical data, including general information, comorbidities with obesity, anthropometric data, and changes in the body fat composition before and after IGB treatment, were obtained from the subjects.

RESULTS

Most subjects had one or more comorbidities, such as osteoarthropathy and woman's disease, and had poor eating behaviors, including irregular mealtimes, eating quickly, and frequent overeating. Body composition measurements showed that weight, fat mass, and waist-hip circumference ratio decreased significantly at 6 mon after IGB treatment. In particular, women with morbid obesity (BMI ≥ 30 kg/m²) showed 33% excess weight loss. There was no significant difference in skeletal muscle mass and mineral contents after IGB treatment.

CONCLUSIONS

This study suggested that 6 mon of IGB treatment can be a beneficial treatment for obesity without muscle mass and bone mineral loss.

Obesity is associated with severe clinical course in children with Henoch-Schonlein purpura

BACKGROUND

We aimed to evaluate the role of obesity on the clinical course and response to treatment in patients with Henoch-Schonlein purpura (HSP).

METHODS

Data charts of children with HSP followed in a tertiary hospital between 2000 and 2018 were reviewed retrospectively. Persistent purpura was defined as skin involvement persisting for ≥ 30 days. Mild nephropathy was defined as the presence of microscopical hematuria and/or non-nephrotic proteinuria, while severe nephropathy as nephrotic proteinuria, nephritic syndrome, and/or kidney insufficiency. Obese and non-obese patients were compared for demographic, clinical, and laboratory parameters.

RESULTS

There were 199 patients (M/F, 104/95; median (IQR) presenting age 7.1 (5.0-9.2) years; follow-up period 17.5 (6-50) months). Obese patients (n = 35 (17.6%)) had significantly higher rate of persistent purpura (46% vs 21%), severe renal involvement (58% vs 31%), high-grade renal histopathological lesions (83% vs 39%), hypertension (29% vs 9%), and increased erythrocyte sedimentation rate (79% vs 56%). Obese patients also showed delayed improvement of cutaneous (25 vs 14 days), articular (12.5 vs 10.0 days), and kidney (280 vs 57 days) symptoms. Obese children used steroids for significantly longer period of time (236 vs 40 days). Furthermore, need for immunosuppressive medications were higher in obese patients (40% vs 9%).

CONCLUSIONS

Obese children with HSP had higher erythrocyte sedimentation rate, hypertension, and severe renal involvement; showed delayed improvement of skin, joint, and kidney findings; and need more immunosuppressive medications and a longer period of steroid treatment. These findings may be associated with the effect of adipose tissue on inflammation.

Elevated expression of FABP4 is associated with disease activity in rheumatoid arthritis patients

Aim: Data from 124 rheumatoid arthritis (RA) patients and 69 healthy controls were collected. Materials & methods: ELISA was performed to detect serum FABP4 levels. Results: FABP4 level was elevated in RA patients and positively associated with 28-joint disease activity score, high-sensitivity C-reactive protein, erythrocyte sedimentation rate, total cholesterol, triglyceride and low-density lipoprotein cholesterol. Additionally, the area under the receiver operating characteristic curve for FABP4 was 0.685 for RA patients versus healthy controls (p = 0.001). RA patients were separated into low, moderate and high disease activity based on 28-joint disease activity score. The area under the receiver operating characteristic value was 0.877 for RA patients with high disease activity versus healthy controls (p < 0.001). Conclusion: FABP4 was associated with disease activity in RA patients.

Adipokines: New Potential Therapeutic Target for Obesity and Metabolic, Rheumatic, and Cardiovascular Diseases

Besides its role as an energy storage organ, adipose tissue can be viewed as a dynamic and complex endocrine organ, which produces and secretes several adipokines, including hormones, cytokines, extracellular matrix (ECM) proteins, and growth and vasoactive factors. A wide body of evidence showed that adipokines play a critical role in various biological and physiological functions, among which feeding modulation, inflammatory and immune function, glucose and lipid metabolism, and blood pressure control. The aim of this review is to summarize the effects of several adipokines, including leptin, diponectin, resistin, chemerin, lipocalin-2 (LCN2), vaspin, omentin, follistatin-like 1 (FSTL1), secreted protein acidic and rich in cysteine (SPARC), secreted frizzled-related protein 5 (SFRP5), C1q/TNF-related proteins (CTRPs), family with sequence similarity to 19 member A5 (FAM19A5), wingless-type inducible signaling pathway protein-1 (WISP1), progranulin (PGRN), nesfatin-1 (nesfatin), visfatin/PBEF/NAMPT, apelin, retinol binding protein 4 (RPB4), and plasminogen activator inhibitor-1 (PAI-1) in the regulation of insulin resistance and vascular function, as well as many aspects of inflammation and immunity and their potential role in managing obesity-associated diseases, including metabolic, osteoarticular, and cardiovascular diseases.

Vaspin deficiency failed to promote the proliferation of BMSCs in osteoarthritis

OBJECTIVE

The aim of this study was to estimate the possible role of vaspin in the proliferation of bone mesenchymal stem cells (BMSCs) and its molecular mechanisms in the bone marrow microenvironment of osteoarthritis (OA).

METHODS

This study included 15 non-obese elderly patients with severe knee OA and 15 non-obese controls with femoral neck fracture. Patients all underwent hip or knee arthroplasty surgery to restore joint shape and function. Bone marrow samples were taken during surgery to estimate vaspin and transforming growth factor (TGF)-β1 levels by enzyme-linked immunosorbent assay and to observe the effect of vaspin on BMSCs proliferation by Cell Counting Kit-8. Real-time polymerase chain reaction and western blot were performed to evaluate the effect of vaspin on the genes and proteins of Akt involved in the PI3K/AKT signaling pathway.

RESULTS

Bone marrow vaspin levels were significantly lower in OA patients compared to controls (P = .03). Furthermore, we found a significant correlation between vaspin and TGF-β1 concentrations in bone marrow (r = .60, P < .01). In addition, the in vitro studies indicated the proliferation of BMSCs was significantly promoted when the vaspin treatment concentration was 150 ng/mL (P < .01). Meanwhile, we found that the Akt messenger RNA and pAkt protein levels in BMSCs were increased after vaspin treatment (P < .05).

CONCLUSION

The findings of this study suggest there was abnormal expression of vaspin in OA bone marrow microenvironment, and vaspin likely had a mediator role in the proliferation of BMSCs, which may work by promoting the activation of the PI3K/AKT signaling pathway.