The role of resistin in inflammatory myopathies

Metabolic mediators determine the association of antinuclear antibody subtypes with specific clinical symptoms in systemic sclerosis

PURPOSE

The aim of this study was to investigate the possible link between different types of systemic sclerosis-specific antinuclear antibodies, adipokines and endothelial molecules which were recently found to have a pathogenic significance in systemic sclerosis.

MATERIALS/METHODS

Serum concentration of adiponectin, resistin, leptin, endothelin-1, fractalkine and galectin-3 were determined in the sera of patients with systemic sclerosis (n ​= ​100) and healthy controls (n ​= ​20) using ELISA.

RESULTS

The following associations between antinuclear antibodies and increased serum concentrations were identified: anticentromere antibodies with endothelin-1 (p ​< ​0.0001; mean level in patients 2.21 vs control group 1.31 ​pg/ml), anti-topoisomerase I antibodies with fractalkine (p ​< ​0.0001; 3.68 vs 1.68 ​ng/ml) and galectin-3 (p ​= ​0.0010, 6.39 vs 3.26 ​ng/ml). Anti-RNA polymerase III antibodies were associated with increased resistin (p ​< ​0.0001; 15.13 vs 8.54 ​ng/ml) and decreased adiponectin (p ​< ​0.0001; 2894 vs 8847 ​ng/ml).

CONCLUSION

In systemic sclerosis metabolic and vascular factors may serve as mediators between immunological abnormalities and non-immune driven clinical symptoms.

BAL and serum multiplex lipid profiling in idiopathic pulmonary fibrosis and fibrotic hypersensitivity pneumonitis

BACKGROUND

Differential diagnosis between IPF and fibrotic HP (fHP) can be challenging: these two ILDs share many common features but call for different therapeutic approaches. In the present study, differential lipid mediator profiles were analysed by a new method in BAL and serum from HP and IPF patients.

MATERIALS AND METHODS

76 patients were enrolled retrospectively in the study. Median age (IQR) was 67 years (51-74); 63% were males, 30 had fHP and 46 had IPF. Serum and BAL samples were collected at initial diagnosis. For quantification of serum and BAL lipid mediators was used bead-based multiplex LEGENDPlex™ analysis (Biolegend).

RESULTS

Serum Apo A1 levels were significantly higher in IPF than fHP patients (p = 0.314); indeed, serum levels of CCL2 and Apo C3 were lower in HP than in IPF patients (p = 0.013 and p = 0.041, respectively). BAL concentrations of Apo A1, adipsin, Apo C3 and APN were significantly lower in IPF than in fHP patients (p < 0.0001, p < 0.0001, p = 0.007 and p = 0.023, respectively). In the logistic regression, IPF was tested as dependent variable. Serum levels of Apo A1, CCL2 and Apo C3 were tested as independent variables and ROC curve analysis of model performance showed AUC 93% (p < 0.0001); on the other hand, BAL concentrations of Apo A1, adipsin, Apo C3 and APN showed AUC 81% (p < 0.0001).

DISCUSSION

Lipid biomarkers evaluated in BAL in our study confirm the hypothesis that fHP and IPF have different lung fibrosis phenotypes. The former is a post-inflammatory cell-regulated ILD and the second is more related to tissue remodeling and repair.

The role of adipokines in systemic sclerosis: a missing link?

Systemic sclerosis is a multiorgan autoimmune disease characterized by vasculopathy and tissue fibrosis of unknown etiology. Recently, adipokines (cell signaling proteins secreted by adipose tissue) have attracted much attention as a cytokine family contributing to the various pathological processes of systemic sclerosis. Adipokines, such as leptin, adiponectin, resistin, adipsin, visfatin or chemerin are a heterogenic group of molecules. Adiponectin exhibits anti-fibrotic features and affects inflammatory reactions. Leptin promotes fibrosis and inflammation. Resistin was linked to vascular involvement in systemic sclerosis. Visfatin was associated with regression of skin lesions in late-stage systemic sclerosis. Chemerin appears as a marker of increased risk of impaired renal function and development of skin sclerosis in the early stage of systemic sclerosis. Vaspin was indicated to have a protective role in digital ulcers development. Novel adipokines-adipsin, apelin, omentin and CTRP-3-are emerging as molecules potentially involved in SSc pathogenesis. Serum adipokine levels may be used as predictive and diagnostic factors in systemic sclerosis. However, further investigations are required to establish firm correlations between distinct adipokines and systemic sclerosis.

Avian genomics lends insights into endocrine function in birds

The genomics era has brought along the completed sequencing of a large number of bird genomes that cover a broad range of the avian phylogenetic tree (>30 orders), leading to major novel insights into avian biology and evolution. Among recent findings, the discovery that birds lack a large number of protein coding genes that are organized in highly conserved syntenic clusters in other vertebrates is very intriguing, given the physiological importance of many of these genes. A considerable number of them play prominent endocrine roles, suggesting that birds evolved compensatory genetic or physiological mechanisms that allowed them to survive and thrive in spite of these losses. While further studies are needed to establish the exact extent of avian gene losses, these findings point to birds as potentially highly relevant model organisms for exploring the genetic basis and possible therapeutic approaches for a wide range of endocrine functions and disorders.

Inflammation status of healthy young men: initial and specific responses to resistance training

Our primary aim was to study the effects of a 4-week preparatory resistance-training (RT) period followed by 12 weeks of 2 specific RT protocols (either hypertrophic-strength (HS) or strength-hypertrophy-power training) on inflammation markers and the possible relationship of the changes in abdominal fat and lean mass to the changes in inflammation status. A total of 82 healthy men were included in the study. Maximal concentric leg press strength (1-repetition maximum), total body lean mass, total body and abdominal fat mass, circulating high-sensitivity C-reactive protein, interleukin-6, interleukin-1 receptor antagonist (IL-1ra), monocyte chemoattractant protein 1 (MCP-1), and selected adipocytokines (resistin, adiponectin, and leptin) concentrations were measured before and after 4 (wk4) and 16 weeks (wk16) of RT. After the initial phase of RT, on wk4, abdominal and total fat mass as well as plasma leptin concentrations were significantly reduced (p < 0.05), whereas muscle mass, IL-1ra, resistin, and MCP-1 concentrations were significantly increased (p < 0.05). During specialized training phase, at wk16, only HS led to further reduction in abdominal and total fat mass, resistin, and leptin (p < 0.05), whereas both training modes led to lower MCP-1 concentrations (p < 0.05). Abdominal fat mass and circulating leptin were reduced already after 4 weeks of RT. Simultaneously, circulating MCP-1 and resistin concentrations increased, possibly as markers of muscle adaptation and regeneration. The present findings also suggest that RT with hypertrophic focus is beneficial for further reductions in abdominal fat mass and to decrease circulating inflammatory markers.

Comparative muscle transcriptome associated with carcass traits of Nellore cattle

Background

Commercial cuts yield is an important trait for beef production, which affects the final value of the products, but its direct determination is a challenging procedure to be implemented in practice. The measurement of ribeye area (REA) and backfat thickness (BFT) can be used as indirect measures of meat yield. REA and BFT are important traits studied in beef cattle due to their strong implication in technological (carcass yield) and nutritional characteristics of meat products, like the degree of muscularity and total body fat. Thus, the aim of this work was to study the Longissimus dorsi muscle transcriptome of Nellore cattle, associated with REA and BFT, to find differentially expressed (DE) genes, metabolic pathways, and biological processes that may regulate these traits.

Results

By comparing the gene expression level between groups with extreme genomic estimated breeding values (GEBV), 101 DE genes for REA and 18 for BFT (false discovery rate, FDR 10%) were identified. Functional enrichment analysis for REA identified two KEGG pathways, MAPK (Mitogen-Activated Protein Kinase) signaling pathway and endocytosis pathway, and three biological processes, response to endoplasmic reticulum stress, cellular protein modification process, and macromolecule modification. The MAPK pathway is responsible for fundamental cellular processes, such as growth, differentiation, and hypertrophy. For BFT, 18 biological processes were found to be altered and grouped into 8 clusters of semantically similar terms. The DE genes identified in the biological processes for BFT were ACHE, SRD5A1, RSAD2 and RSPO3. RSAD2 has been previously shown to be associated with lipid droplet content and lipid biosynthesis.

Conclusion

In this study, we identified genes, metabolic pathways, and biological processes, involved in differentiation, proliferation, protein turnover, hypertrophy, as well as adipogenesis and lipid biosynthesis related to REA and BFT. These results enlighten some of the molecular processes involved in muscle and fat deposition, which are economically important carcass traits for beef production.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-017-3897-x) contains supplementary material, which is available to authorized users.

Serum levels of resistin and interleukin-17 are associated with increased cartilage defects and bone marrow lesions in patients with knee osteoarthritis

OBJECTIVES

To investigate cross-sectional associations between serum levels of resistin and interleukin-17 (IL-17) and cartilage defects and bone marrow lesions (BMLs) in patients with knee symptomatic osteoarthritis (OA).

METHODS

One hundred and ninety-four consecutively-selected patients with knee symptomatic OA (mean 55.4 years, range 34-74, 87% females) were included in Anhui Osteoarthritis (AHOA) Study. Knee cartilage defects and BMLs were determined at different sites using T2-weighted fat-suppressed fast spin echo MRI. Serum resistin, IL-17, and high-sensitivity C-reactive protein (hs-CRP) levels were measured using ELISA.

RESULTS

In multivariable analyses, serum resistin was positively associated with cartilage defects at lateral femoral, lateral tibial, and medial tibial (all p < 0.05) sites. The significant associations were also present with BMLs at lateral femoral and tibial sites (ORs: 1.13-1.19, both p < 0.05). In patients with the highest quartile of hs-CRP (>2.45 pg/ml), IL-17 was positively and significantly associated with cartilage defect score at nearly all sites (ORs: 1.33-1.44, all p < 0.05), and BMLs at lateral and medial femoral sites (ORs: 1.26-1.51, both p < 0.05).

CONCLUSIONS

Serum levels of resistin were positively and independently associated with cartilage defects and BMLs in patients with knee OA. Serum IL-17 was significantly associated with cartilage defects and BMLs in patients with an increased inflammatory status. These suggest that metabolic and inflammatory mechanisms may have a role to play in knee OA.

Idiopathic inflammatory myopathies

The idiopathic inflammatory myopathies (IIM) consist of rare heterogeneous autoimmune disorders that present with marked proximal and symmetric muscle weakness, except for distal and asymmetric weakness in inclusion body myositis. Despite many similarities, the IIM are fairly heterogeneous from the histopathologic and pathogenetic standpoints, and also show some clinical and treatment-response differences. The field has witnessed significant advances in our understanding of the pathophysiology and treatment of these rare disorders. This review focuses on dermatomyositis, polymyositis, and necrotizing myopathy, and examines current and promising therapies.

Clinical significance of resistin expression in osteoarthritis: a meta-analysis

Background. The objective of this study was to conduct a systematic review of literature evaluating human resistin expression as a diagnostic factor in osteoarthritis development and to quantify the overall diagnostic effect. Method. Relevant studies were identified and evaluated for quality through multiple search strategies. Studies analyzing resistin expression in the development of OA were eligible for inclusion. Data from eligible studies were extracted and included into the meta-analysis using a random-effects model. Results. Four case-control studies consisting of a total of 375 OA patients and 214 controls as well as three sex-stratified analyses composed of 53 males and 104 females were incorporated into our meta-analysis. Our results revealed that resistin levels were significantly higher in male OA subjects and OA patients overall. Country-stratified analysis yielded significantly different estimates in resistin levels between male OA subjects and female OA subjects in the Canadian subgroup but not among the French and USA subgroups. Based on the resistin levels in OA cases and controls, resistin levels were heightened in OA patients in the Dutch population. Conclusion. These results support the hypothesis that high expression of resistin represents a significant and reproducible marker of poor progression in OA patients, especially in males.