TWEAK: A New Player in Obesity and Diabetes

Inflammation and Neurodegeneration in Glaucoma: Isolated Eye Disease or a Part of a Systemic Disorder? - Serum Proteomic Analysis

Introduction

Glaucoma is the most common optic neuropathy and the leading cause of irreversible blindness worldwide, which affects 3.54% of the population aged 40-80 years. Despite numerous published studies, some aspects of glaucoma pathogenesis, serum biomarkers, and their potential link with other diseases remain unclear. Recent articles have proposed that autoimmune, oxidative stress and inflammation may be involved in the pathogenesis of glaucoma.

Methods

We investigated the serum expression of 92 inflammatory and neurotrophic factors in glaucoma patients. The study group consisted of 26 glaucoma patients and 192 healthy subjects based on digital fundography.

Results

Patients with glaucoma had significantly lower serum expression of IL-2Rβ, TWEAK, CX3CL1, CD6, CD5, LAP TGF-beta1, LIF-R, TRAIL, NT-3, and CCL23 and significantly higher expression of IL-22Rα1.

Conclusion

Our results indicate that patients with glaucoma tend to have lower levels of neuroprotective proteins and higher levels of neuroinflammatory proteins, similar to those observed in psychiatric, neurodegenerative and autoimmune diseases, indicating a potential link between these conditions and glaucoma pathogenesis.

Exercise Improves Clinical Symptoms, Pathological Changes and Oxidative/Antioxidative Balance in Animal Model of Colitis

Background

Ulcerative colitis is one of the major phenotypic forms of inflammatory bowel diseases. The present study aimed to investigate the effect of force swimming exercise on clinical symptoms (disease activity index; DAI), colon histopathology, inflammation and fibrosis, and oxidant/antioxidant balance in dextran sulfate sodium (DSS)-induced colitis mice.

Methods

Male C57BL6 mice were randomly divided into five groups (n = 6 each): control, exercise, colitis, colitis + sulfasalazine, and colitis + exercise. Exercise was performed by forced swimming six weeks before and during the experiment. Colitis was induced by 1.5% DSS in drinking water. The animals were evaluated for body weight changes and DAI (including changes of body weight, stool consistency, rectal bleeding, and prolapse) during the induction of colitis and treatment. At the end of experiment, colons and spleens were evaluated by H and E and Masson Trichrome stainings. Oxidant (Malon dialdehyde; MDA), and antioxidant markers [total thiol groups, superoxide dismutase (SOD), and catalase activity] were also measured in colon tissue.

Results

Results indicated that exercise in colitis mice significantly improved DAI, colon length, spleen weight, and histological injury score and alleviated fibrotic changes in colon tissue that were comparable to sulfasalazine group. Exercise also restored the oxidant/antioxidant balance in colitis mice by reducing MDA and increasing antioxidative markers including total thiol groups, SOD, and catalase activity.

Conclusions

Taken together, aerobic exercise could improve clinical symptoms and colonic inflammation through, at least, the balancing the oxidative stress markers. Thus, it can be considered in management of colitis patients as effective method.

Transcriptional heterogeneity in human diabetic foot wounds

Wound repair requires the coordination of multiple cell types including immune cells and tissue resident cells to coordinate healing and return of tissue function. Diabetic foot ulceration is a type of chronic wound that impacts over 4 million patients in the US and over 7 million worldwide (Edmonds et al., 2021). Yet, the cellular and molecular mechanisms that go awry in these wounds are not fully understood. Here, by profiling chronic foot ulcers from non-diabetic (NDFUs) and diabetic (DFUs) patients using single-cell RNA sequencing, we find that DFUs display transcription changes that implicate reduced keratinocyte differentiation, altered fibroblast function and lineages, and defects in macrophage metabolism, inflammation, and ECM production compared to NDFUs. Furthermore, analysis of cellular interactions reveals major alterations in several signaling pathways that are altered in DFUs. These data provide a view of the mechanisms by which diabetes alters healing of foot ulcers and may provide therapeutic avenues for DFU treatments.

TWEAK-Fn14-RelB Signaling Cascade Promotes Stem Cell-like Features that Contribute to Post-Chemotherapy Ovarian Cancer Relapse

Disease recurrence in high-grade serous ovarian cancer may be due to cancer stem-like cells (CSC) that are resistant to chemotherapy and capable of reestablishing heterogeneous tumors. The alternative NF-κB signaling pathway is implicated in this process; however, the mechanism is unknown. Here we show that TNF-like weak inducer of apoptosis (TWEAK) and its receptor, Fn14, are strong inducers of alternative NF-κB signaling and are enriched in ovarian tumors following chemotherapy treatment. We further show that TWEAK enhances spheroid formation ability, asymmetric division capacity, and expression of SOX2 and epithelial-to-mesenchymal transition genes VIM and ZEB1 in ovarian cancer cells, phenotypes that are enhanced when TWEAK is combined with carboplatin. Moreover, TWEAK in combination with chemotherapy induces expression of the CSC marker CD117 in CD117- cells. Blocking the TWEAK-Fn14-RelB signaling cascade with a small-molecule inhibitor of Fn14 prolongs survival following carboplatin chemotherapy in a mouse model of ovarian cancer. These data provide new insights into ovarian cancer CSC biology and highlight a signaling axis that should be explored for therapeutic development.

IMPLICATIONS

This study identifies a unique mechanism for the induction of ovarian cancer stem cells that may serve as a novel therapeutic target for preventing relapse.

Links between ectopic and abdominal fat and systemic inflammation: New insights from the SHIP-Trend study

BACKGROUND

Excessive fat accumulation in adipose tissue depots and organs such as the pancreas and the liver is associated with systemic low-grade chronic inflammation.

AIMS

To investigate the association between abdominal, hepatic, and pancreatic fat and the circulating level of inflammatory biomarkers.

METHODS

We used data from a subsample of the Study of Health in Pomerania (SHIP-Trend, n = 469). The plasma concentration of 37 inflammatory biomarkers was measured using the Bio-Plex-Pro™-Human-Inflammation-Panel-1. Subcutaneous and visceral adipose tissue (SAT and VAT), as well as hepatic and pancreatic fat, were determined by magnetic resonance imaging. We assessed the associations between fat content and inflammatory biomarkers using multiple linear regression.

RESULTS

Hepatic fat was associated with MMP-2 (β -0.11), PTX3 (β -0.14), and TNFSF12 (β -0.06). Pancreatic fat was associated with sTNFR1 (β 0.15), sTNFR2 (β 0.11), and sCD163 (β 0.13). VAT and SAT were associated with sCD163 (β^VAT 0.20, β^SAT 0.16), MMP-2 (β^VAT -0.12, β^SAT -0.10), OSTCN (β^VAT -0.16, β^SAT -0.10), sTNFR1 (β^VAT 0.13, β^SAT 0.13), sTNFR2 (β^VAT 0.13, β^SA 0.12), TNFSF12 (β^VAT -0.11, β^SAT -0.08), and TNFSF14 (β^VAT 0.21, β^SAT 0.20). VAT was additionally associated with TNFSF13B (β 0.08) and CHI3L1 (β 0.07).

CONCLUSIONS

Our findings provide new insights into the involvement of hepatic and pancreatic fat on systemic inflammation.

The TWEAK/Fn14/CD163 axis-implications for metabolic disease

TWEAK (tumor necrosis factor-like weak inducer of apoptosis) is a member of the TNF superfamily that controls a multitude of cellular events including proliferation, migration, differentiation, apoptosis, angiogenesis, and inflammation. TWEAK control of these events is via an expanding list of intracellular signalling pathways which include NF-κB, ERK/MAPK, Notch, EGFR and AP-1. Two receptors have been identified for TWEAK - Fn14, which targets the membrane bound form of TWEAK, and CD163, which scavenges the soluble form of TWEAK. TWEAK appears to elicit specific events based on the receptor to which it binds, tissue type in which it is expressed, specific extrinsic conditions, and the presence of other cytokines. TWEAK signalling is protective in healthy tissues, but in chronic inflammatory states become detrimental to the tissue. Consistent data show a role for the TWEAK/FN14/CD163 axis in metabolic disease, chronic autoimmune diseases, and acute ischaemic stroke. Low circulating concentrations of soluble TWEAK are predictive of poor cardiovascular outcomes in those with and without diabetes. This review details the current understanding of the TWEAK/Fn14/CD163 axis as one of the chief regulators of immune signalling and its cell-specific role in metabolic disease development and progression.

Limited extent and consequences of pancreatic SARS-CoV-2 infection

Concerns that infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiological agent of coronavirus disease 2019 (COVID-19), may cause new-onset diabetes persist in an evolving research landscape, and precise risk assessment is hampered by, at times, conflicting evidence. Here, leveraging comprehensive single-cell analyses of in vitro SARS-CoV-2-infected human pancreatic islets, we demonstrate that productive infection is strictly dependent on the SARS-CoV-2 entry receptor ACE2 and targets practically all pancreatic cell types. Importantly, the infection remains highly circumscribed and largely non-cytopathic and, despite a high viral burden in infected subsets, promotes only modest cellular perturbations and inflammatory responses. Similar experimental outcomes are also observed after islet infection with endemic coronaviruses. Thus, the limits of pancreatic SARS-CoV-2 infection, even under in vitro conditions of enhanced virus exposure, challenge the proposition that in vivo targeting of β cells by SARS-CoV-2 precipitates new-onset diabetes. Whether restricted pancreatic damage and immunological alterations accrued by COVID-19 increase cumulative diabetes risk, however, remains to be evaluated.

New Insights in Cytokines in Childhood Obesity: Changes in TWEAK and CD163 After a 2-Year Intervention Program in Prepubertal Children With Obesity

OBJECTIVE

Obesity is characterized by a low-grade inflammatory state in adipose tissue. Tumor Necrosis Factor Weak Inducer of Apoptosis (TWEAK) and Cluster of Differentiation 163 (CD163) are cytokines potentially involved in the pathogenesis of obesity. Little is known about them in children. The aim of this study was to observe serum levels of TWEAK and CD163 in prepubertal children with obesity compared to lean, and to evaluate its changes after a 2-year intervention program in children with obesity.

METHODS

Case-control study with a prospective follow-up of cases for 2 years in a referral pediatric endocrine outpatient centre. Seventy-three prepubertal children with obesity, and forty-seven age- and gender-matched lean controls were studied. Sixty-two cases finished the program. Anthropometric parameters, Homeostatic Model Assessment for Insulin Resistance (HOMA-IR), lipid profile, and concentrations of TWEAK and CD163 were determined. Children with obesity were re-evaluated after a 2-year intervention program consisting of diet and exercise. Weight loss was considered if z-score Body Mass Index (BMI) decreased at least 0.5 Standard Deviations (SD).

RESULTS

We observed higher CD163 levels in children with obesity compared to controls. No significant differences were observed in TWEAK and CD163/TWEAK ratio at baseline. After the 2-year intervention program, TWEAK levels were higher and CD163/TWEAK ratio was lower in children with weight loss than those without weight loss. CD163 decreased in both groups.

CONCLUSION

TWEAK and CD163 seem to have a role in the pathogenesis of obesity in prepubertal children.

Circulating sTweak is associated with visceral adiposity and severity in patients with obstructive sleep apnea syndrome

Hypoxia is linked to an inflammatory imbalance in obstructive sleep apnea syndrome (OSAS). Circulating soluble tumor necrosis factor (TNF)-like weak inducer of apoptosis (sTWEAK) is a cytokine that regulates inflammation and insulin resistance in adipose tissue. This study first investigated sTWEAK concentrations in patients OSAS and evaluated associations between sTWEAK concentrations and visceral adiposity, metabolic dysfunction, and hypoxia observed in OSAS. Forty age, sex, and body mass index-matched patients with simple habitual snoring (HSS) and 70 patients with OSAS were included. Patients were divided according to OSAS severity: mild-moderate (apnea–hypopnea index, AHI 5–30 events/h) and severe (AHI ≥ 30 events/h). Anthropometric data, glucose metabolism, visceral fat (VF) ratio, and sTWEAK levels were compared. sTWEAK levels were higher in the OSAS group than in the HSS group (931.23 ± 136.48 vs. 735.22 ± 102.84 ng/L, p = 0.001). sTWEAK levels were higher in severe OSAS than in mild-moderate OSAS (1031.83 ± 146.69 vs. 891.01 ± 110.01 ng/L, p = 0.002. When we evaluated the sTWEAK value and AHI, VF ratio, total cholesterol, blood pressure, homeostasis model of assessment-insulin resistance, and high-sensitivity C-reactive protein using multiple regression analysis, a significant correlation was found between sTWEAK levels and AHI (p < 0.001). It was found that sTWEAK levels were not correlated with glucose metabolism and VF ratio. Increased circulating sTWEAK levels were associated with the severity of OSAS. High sTWEAK levels were correlated with increased AHI. sTWEAK concentrations are linked to severe OSAS.

Serum Levels of the Cytokine TWEAK Are Associated with Metabolic Status in Patients with Prostate Cancer and Modulate Cancer Cell Lipid Metabolism In Vitro

Simple Summary

TWEAK is an inflammatory cytokine related to prostate cancer (PCa) progression that exerts its effects by engaging its cognate receptor Fn14. A soluble form of TWEAK (sTWEAK) has been detected in the PCa microenvironment. Altered levels of circulating sTWEAK are associated with aberrant glucose metabolism. We show that reduced serum levels of sTWEAK are associated with the metabolic status in patients with PCa and that the treatment of PC-3 cells with sTWEAK enhances the expression of genes related to lipid, but not to glucose, metabolism. sTWEAK also increases the lipid uptake and lipid accumulation in PC-3 cells. We corroborated that the observed effects were due to TWEAK/Fn14 engagement by silencing Fn14 expression, which attenuated the aberrant gene and protein expression. Additionally, we observed that the phosphorylation of ERK1/2 and AKT (ser473) were required for TWEAK/Fn14 actions. Thus, the contribution of the sTWEAK/Fn14 axis on PCa metabolism supports its potential as a therapeutic target for PCa.

Abstract

Soluble TWEAK (sTWEAK) has been proposed as a prognostic biomarker of prostate cancer (PCa). We found that reduced serum levels of sTWEAK, together with higher levels of prostate-specific antigen and a higher HOMA-IR index, are independent predictors of PCa. We also showed that sTWEAK stimulus failed to alter the expression of glucose transporter genes (SLC2A4 and SLC2A1), but significantly reduced the expression of glucose metabolism-related genes (PFK, HK1 and PDK4) in PCa cells. The sTWEAK stimulation of PC-3 cells significantly increased the expression of the genes related to lipogenesis (ACACA and FASN), lipolysis (CPT1A and PNPLA2), lipid transport (FABP4 and CD36) and lipid regulation (SREBP-1 and PPARG) and increased the lipid uptake. Silencing the TWEAK receptor (Fn14) in PC-3 cells confirmed the observed lipid metabolic effects, as shown by the downregulation of ACACA, FASN, CPT1A, PNPLA2, FABP4, CD36, SREBP-1 and PPARG expression, which was paralleled by a reduction of FASN, CPT1A and FABP4 protein expression. Specific-signaling inhibitor assays show that ERK1/2 and AKT (ser473) phosphorylation can regulate lipid metabolism-related genes in PCa cells, pointing to the AKT locus as a possible target for PCa. Overall, our data support sTWEAK/Fn14 axis as a potential therapeutic target for PCa.

Effects of donkey milk on oxidative stress and inflammatory response

Donkey milk is gaining interest as a natural nutritional and medicinal product, mainly because its composition is similar to that of human milk, and it has some potential biological properties, such as antioxidant, anti-inflammatory, antiaging, antimicrobial, and anticancer properties. Considering the increasing prevalence of several chronic diseases related to oxidative stress and inflammation and the multiple beneficial properties and nutritional value of donkey milk, an up-to-date review of the current studies related to the antioxidative and anti-inflammatory abilities of donkey milk is necessary. Therefore, this review aims to discuss the relationship between inflammation and oxidative stress; and to further systematically review the progress of recent research on donkey milk, mainly including its nutritional value and functional properties. Particularly, we highlighted the anti-inflammatory and antioxidative properties of donkey milk using in vitro model, animal model, and the potential role of donkey milk in alleviating some chronic diseases related to inflammation. PRACTICAL APPLICATIONS: This paper was conducted on anti-inflammation and antioxidant activities of donkey milk and its related products, in addition to a summary of the relationship between oxidative stress and inflammation and the value of donkey milk. Donkey milk and its related products have been shown to scavenge reactive oxygen species, activate the antioxidant system, enhance immune function, and maintain the balance of intestinal flora in in vitro and in vivo models. This paper should provide a better understanding of the influences of oxidative stress and inflammation on host health and the biological functions and application of donkey milk, and will provide a certain basis for the nutritional regulation of several chronic diseases related to oxidative stress and inflammation. However, the underlying mechanism is poorly understood. In addition, few clinical studies have been performed to establish its multiple benefits in humans. Further research is warranted to evaluate its impacts on health at molecular levels.

Higher levels of IL-18 in patients with prediabetes compared to obese normoglycaemic controls

Background: Overweight and obesity are linked to low-grade chronic inflammation that can impair normal insulin function and induce insulin resistance. The aim of this study was to compare IL-18 levels between patients with prediabetes and obese normoglycaemic controls.Patients and methods: In this study, we included 131 patients with mean age 54.9 ± 9.1 years, divided into two groups - group 1 with obesity without glycaemic disturbances (n = 66) and group 2 with prediabetes (n = 65). IL-18 was measured using enzyme-linked immunosorbent assay (ELISA) method.Results: Patients with prediabetes had significantly higher levels of IL-18 compared to obese controls (304.0 ± 220.4 vs. 233.6 ± 103.6 pg/l, p=.029). When patients with prediabetes were divided into IFG only, IGT only and IFG + IGT the highest levels of IL-18 were found in IGT only patients.Conclusions: Patients with prediabetes have higher levels of IL18 compared to obese normoglycemic controls.

TRAIL, OPG, and TWEAK in kidney disease: biomarkers or therapeutic targets?

Ligands and receptors of the tumor necrosis factor (TNF) superfamily regulate immune responses and homeostatic functions with potential diagnostic and therapeutic implications. Kidney disease represents a global public health problem, whose prevalence is rising worldwide, due to the aging of the population and the increasing prevalence of diabetes, hypertension, obesity, and immune disorders. In addition, chronic kidney disease is an independent risk factor for the development of cardiovascular disease, which further increases kidney-related morbidity and mortality. Recently, it has been shown that some TNF superfamily members are actively implicated in renal pathophysiology. These members include TNF-related apoptosis-inducing ligand (TRAIL), its decoy receptor osteoprotegerin (OPG), and TNF-like weaker inducer of apoptosis (TWEAK). All of them have shown the ability to activate crucial pathways involved in kidney disease development and progression (e.g. canonical and non-canonical pathways of the transcription factor nuclear factor-kappa B), as well as the ability to regulate cell proliferation, differentiation, apoptosis, necrosis, inflammation, angiogenesis, and fibrosis with double-edged effects depending on the type and stage of kidney injury. Here we will review the actions of TRAIL, OPG, and TWEAK on diabetic and non-diabetic kidney disease, in order to provide insights into their full clinical potential as biomarkers and/or therapeutic options against kidney disease.

Soluble CD163 and TWEAK in early pregnancy gestational diabetes and later glucose intolerance

Gestational diabetes mellitus (GDM) is today universally diagnosed during late pregnancy. Treating hyperglycaemia during pregnancy reduces the risk of complications, the effect of interventions is however limited due to the late diagnosis. It is thus important to identify biomarkers reaching a high precision for GDM development in early pregnancy. Here we aim to investigate soluble CD163 (sCD163) and soluble tumour necrosis factor-like weak inducer of apoptosis (sTWEAK) in early pregnancy GDM and their association to the development of later glucose intolerance. In this case-control study, women diagnosed with GDM in early pregnancy (n = 70) at Lund University Hospital, Lund, Sweden in 2011-2015 were age- and BMI matched to pregnant volunteers without diabetes (n = 70) recruited in early pregnancy from maternal health care centres in 2014-2015. Plasma levels of sCD163 and sTWEAK were analysed using commercial ELISA. Plasma levels of sCD163 did not differ between patients with and without GDM in early pregnancy (p = 0.86), plasma levels of sTWEAK however was decreased in women with GDM (0.71 [0.4-1.75] ng/ml) compared to controls (1.38 [0.63-4.86] ng/ml; p = 0.003). Women with sTWEAK levels in the lowest tertile had an increased risk of GDM in early pregnancy (p = 0.014). Neither sCD163 nor sTWEAK were associated with later glucose intolerance in women with GDM. This study reports decreased levels of sTWEAK in women with early pregnancy GDM, independent of age and BMI. Neither sCD163 nor sTWEAK were found to be associated to later glucose intolerance.

Multi-omic analysis of signalling factors in inflammatory comorbidities

BACKGROUND

Inflammation is a core element of many different, systemic and chronic diseases that usually involve an important autoimmune component. The clinical phase of inflammatory diseases is often the culmination of a long series of pathologic events that started years before. The systemic characteristics and related mechanisms could be investigated through the multi-omic comparative analysis of many inflammatory diseases. Therefore, it is important to use molecular data to study the genesis of the diseases. Here we propose a new methodology to study the relationships between inflammatory diseases and signalling molecules whose dysregulation at molecular levels could lead to systemic pathological events observed in inflammatory diseases.

RESULTS

We first perform an exploratory analysis of gene expression data of a number of diseases that involve a strong inflammatory component. The comparison of gene expression between disease and healthy samples reveals the importance of members of gene families coding for signalling factors. Next, we focus on interested signalling gene families and a subset of inflammation related diseases with multi-omic features including both gene expression and DNA methylation. We introduce a phylogenetic-based multi-omic method to study the relationships between multi-omic features of inflammation related diseases by integrating gene expression, DNA methylation through sequence based phylogeny of the signalling gene families. The models of adaptations between gene expression and DNA methylation can be inferred from pre-estimated evolutionary relationship of a gene family. Members of the gene family whose expression or methylation levels significantly deviate from the model are considered as the potential disease associated genes.

CONCLUSIONS

Applying the methodology to four gene families (the chemokine receptor family, the TNF receptor family, the TGF- β gene family, the IL-17 gene family) in nine inflammation related diseases, we identify disease associated genes which exhibit significant dysregulation in gene expression or DNA methylation in the inflammation related diseases, which provides clues for functional associations between the diseases.

Visceral white adipose tissue and serum proteomic alternations in metabolically healthy obese patients undergoing bariatric surgery

Metabolically healthy obesity is characterized as a comorbidity-free obesity status, however the exact pathogenetic mechanisms implicated in its transition to unhealthy obesity have not yet been unveiled. Our aim was to investigate the effect of metabolic health on the proteomic profile both in serum and visceral fat of morbidly obese subjects. 28 patients undergoing bariatric surgery were prospectively enrolled. They were divided into two groups: metabolically healthy (MHO, n = 18) and unhealthy (MUO, n = 10) obese patients. 30 biomarkers were measured in serum and visceral adipose tissue with the use of targeted proteomic analysis (Luminex assays). TNF weak inducer of apoptosis (TWEAK) (p = 0.043), TNF related apoptosis inducing ligand (TRAIL) (p = 0.037), Growth differentiation factor-15 (GDF-15) (p = 0.04), Resistin (RETN) (p = 0.047), Matrix metalloproteinase-9 (MMP-9) (p = 0.011) and C-terminal telopeptide (ICTP) (p = 0.022) were up-regulated in the MUO group in the visceral white adipose tissue. Moreover, C-C motif ligand-3 (CCL-3) (p = 0.056), Interleukin-20 (IL-20) (p = 0.04), Prokineticin-1 (PROK-1) (p = 0.028) and TWEAK (p = 0.016) were found to be suppressed in the serum of MHO group. Significant correlations between serum and adipose tissue levels of certain cytokines were also observed, while 16 biomarkers were associated with BMI. Our results indicate metabolic health substantially attenuates the expression of TWEAK, TRAIL, GDF-15, RETN, MMP-9 and ICTP expression locally, in the visceral white adipose tissue, and the expression of CCL-3, IL-20, PROK-1 and TWEAK in the peripheral blood. Intriguingly, different cytokines -except for TWEAK- are up-regulated in each site, suggesting that obesity is not a homogenous but a multi-dimensional disease.

Soluble Tumor Necrosis Factor (TNF)-Like Weak Inducer of Apoptosis (Tweak) Independently Predicts Subclinical Atherosclerosis in Behcet's Disease

BACKGROUND

Vasculopathy is a major cause of mortality and morbidity in Behcet's Disease (BD). Subclinical atherosclerosis can even be detected in the early stage of BD. Soluble tumor necrosis factor-like (TNF) weak inducer of apoptosis (TWEAK) is known as a good marker of the inflammation in vascular tree. The aim of this study is to examine the relationship between carotid artery intima-media thickness (cIMT) and serum TWEAK levels in patients with BD.

MATERIALS AND METHODS

In line with International BD Study Group criteria, 48 BD, and 30 controls were included in our study. Disease activity was evaluated according to BD current activity form (BDCAF). C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), lipid parameters, serum TWEAK levels, and cIMT were measured.

RESULTS

Disease activity score of BD patients was found as 2 (range 0-7). cIMT, serum TWEAK, CRP and ESR levels of BD patients were significantly higher comparing to cIMT (0.62 ± 0.13 mm vs. 0.43 ± 0.09 mm, p < 0.001), serum TWEAK (667.5 ± 130.6 vs. 603.4 ± 89.6 pg/ml, p = 0.015), CRP (3.9 ± 4.3 vs. 1.4 ± 1.0 mg/dl, p < 0.001) and ESR (10.2 ± 10.0 vs. 5.6 ± 3.7 mm/h, p = 0.005) levels of the control group. There was a positive correlation between serum TWEAK level and disease activity (r = 0.251, p = 0.030) and cIMT (r = 0.463, p < 0.001). Our study also revealed an independent correlation between cIMT and serum TWEAK levels (beta = 0.354, p < 0.001).

CONCLUSION

Increased serum TWEAK levels can play a part in the development of atherosclerotic heart disease in BD. Due to their liability to atherosclerosis, patients with BD must followed closely.

CGRP and PTX3 as Predictors of Efficacy of Onabotulinumtoxin Type A in Chronic Migraine: An Observational Study

OBJECTIVE

The aim of this study is to find a relation between several biomarkers in peripheral blood and outcome after treatment with onabotulinumtoxin A (OnabotA).

BACKGROUND

OnabotA is an effective treatment in chronic migraine (CM). Different studies have tried to find predictors of response to treatment, either with clinical characteristics, neuroimaging features, or molecular biomarkers; however, it is still not possible to predict the individual outcome.

METHODS

We measured serum levels of biomarkers of inflammation (IL-6, IL-10, TNF-α, and hs-CRP), endothelial dysfunction (PTX3 and sTWEAK), blood-brain barrier disruption (cFN), brain damage (S100b, NSE), and trigemino-vascular activation (CGRP) by ELISA in a group of CM patients treated with OnabotA and healthy controls. After 24 weeks, patients were classified in two groups according to their outcome considering variations in headache frequency: nonresponders (nonimprovement or improvement <50%) and responders (improvement >50%). We compared baseline levels of biomarkers between these groups.

RESULTS

Sixty-two patients diagnosed with CM (IHS 2013 criteria) who fulfilled criteria for treatment with OnabotA and 24 healthy controls were included. Fifteen patients did not respond to treatment (24.2%) and 47 were responders (75.8%). Pentraxin 3 (PTX3) serum levels (1455.4 ± 487.5 pg/mL versus 720.3 ± 334.1 pg/mL, P < .0001) and calcitonin gene-related peptide (CGRP) serum levels (133.1 ± 86.6 ng/mL versus 58.2 ± 91.7 ng/mL, P = .004) were significantly higher in responders than nonresponders. Serum basal levels of PTX3 >1000 pg/mL (AUC 0.908; 95% CI: 0.827-0.990) and CGRP >50 ng/mL (AUC 0.800; 95% CI: 0.652-0.947) were associated with good response to OnabotA treatment.

CONCLUSIONS

These results show that molecular markers of trigeminovascular activation (CGRP) and endothelial dysfunction (PTX3) are associated with response to OnabotA and may act as new biomarkers for the selection of treatment in chronic migraineurs.

Soluble TWEAK may predict carotid atherosclerosis in treated HIV infection

BACKGROUND

Soluble Tumor Necrosis Factor Weak Inducer of Apoptosis (sTWEAK) has been proposed as a novel biomarker of cardiovascular disease risk. This study compares levels of sTWEAK, sCD163 and the sCD163/sTWEAK ratio in HIV-infected and uninfected patients and their associations with cardiovascular and inflammatory factors.

METHODS

The data for our analysis come from 274 HIV-infected adults and 59 controls. HIV participants were on stable antiretroviral therapy (ART). Wilcoxon-Mann-Whitney tests were used for comparing markers between HIV-infected participants with HIV viral load <50 copies/mL (aviremic group), HIV-infected participants with detectable viremia (HIV-1 RNA ≥50 copies/mL; viremic group) and HIV negative participants. Multivariable quantile regression analyses were used to assess associations of sTWEAK and sCD163 with other markers of inflammation and carotid intima-media thickness (cIMT).

RESULTS

Overall, 74% of participants were male; 59% were African-Americans; median age was 40 years and CD4 595 cells/mm3. Overall, HIV-infected participants had reduced sTWEAK and increased sCD163 levels compared to HIV-uninfected participants (p = 0.0001 for both markers). In addition, these biomarkers were significantly different between HIV-infected viremic and aviremic patients (p ≤ 0.01 for both markers). In multivariable models, sTWEAK and sCD163 in aviremic patients were significantly correlated with common carotid artery IMT (p ≤ 0.05). In HIV-infected aviremic participants, sTWEAK and sCD163 were both associated with IL-6, CD14 + CD16 + monocytes (p ≤ 0.02); additionally, sCD163 was associated with D-dimer- (β = -69.5, 0.05), VCAM (β = 72.4, p = 0.05), TNF RI (β = 91.1, p < 0.01), and TNF RII (β = 87.8, p < 0.01).

CONCLUSIONS

HIV-infected participants showed increased systemic inflammatory and monocyte activation markers. Soluble CD163 and sTWEAK levels were associated with carotid intima-media thickness.

Obesity, metabolic syndrome and diabetic retinopathy: Beyond hyperglycemia

Diabetic retinopathy (DR) is the most feared ocular manifestation of diabetes. DR is characterized by progressive retinal damage that may eventually result in blindness. Clinically, this blindness is caused by progressive damage to the retinal microvasculature, which leads to ischemia, retinal swelling, and neovascularization. Retinopathy is associated with both type 1 and type 2 diabetes, with DR being the leading cause of new onset blindness in United States adults. Despite this strong association with diabetes, it must be noted that the development of retinopathy lesions is multifactorial and may occur in individuals without an established history of diabetes. Metabolic syndrome is a multifactorial condition of central obesity, hypertriglyceridemia, dyslipidemia, hypertension, fasting hyperglycemia, and insulin resistance. Although several studies examined the individual components observed in the metabolic syndrome in relation to the development of DR, there is conflicting data as to the association of the metabolic syndrome with the development of retinopathy lesions in non-diabetic subjects. This review will summarize the current literature on the evidence of the metabolic syndrome on retinopathy in subjects with and without an established history of diabetes. This review will also discuss some of the mechanisms through which metabolic syndrome can contribute to the development of retinopathy.

Overexpressing STAMP2 attenuates adipose tissue angiogenesis and insulin resistance in diabetic ApoE-/- /LDLR-/- mouse via a PPARγ/CD36 pathway

The aim of this study was to investigate whether overexpression of STAMP2 improves insulin resistance by regulating angiogenesis in adipose tissues. The characteristics of diabetic mice were measured by serial metabolite and pathology tests. Samples were obtained from epididymal, subcutaneous and brown adipose tissues. Histological and morphological analysis demonstrated that STAMP2 gene overexpression reduced adipocyte size, angiogenesis in epididymal and brown adipose tissues. On aortic ring assay, microvessels sprouting from aortas were significantly inhibited after STAMP2 gene overexpression. The cellular effect of STAMP2 on angiogenesis was explored in human umbilical vein endothelial cells (HUVECs) model. Correlation of STAMP2 and angiogenesis was validated by Ad‐STAMP2 transfection and STAMP2 siRNA inhibition. In vitro, overexpression of STAMP2 significantly inhibited endothelial cell migration, tube formation. The effects of Ad‐STAMP2 transfection on HUVECs were abolished by treatment with PPARγ antagonist GW9662 (2.5 μM), and the roles of STAMP2 siRNA on HUVECs were also reversed by treatment with PPARγ agonist rosiglitazone (RSG) (0.1 mM). RT‐PCR indicated that STAMP2 could regulate levels of adhesion molecules, vascular endothelial growth factor A and CD36. The expression of PPARγ and CD36 was decreased when STAMP2 was inhibited by siRNA, while PPARγ and CD36 were highly expressed after overexpression of STAMP2. Our results suggested that STAMP2 gene overexpression may improve insulin resistance via attenuating angiogenesis in epididymal and brown adipose tissues through the PPARγ/CD36 signalling pathway.

Beneficial Effect of Voluntary Exercise on Experimental Colitis in Mice Fed a High-Fat Diet: The Role of Irisin, Adiponectin and Proinflammatory Biomarkers

Inflammatory bowel diseases (IBDs) are a heterogeneous group of disorders exhibited by two major phenotypic forms: Crohn‘s disease and ulcerative colitis. Although the aetiology of IBD is unknown, several factors coming from the adipose tissue and skeletal muscles, such as cytokines, adipokines and myokines, were suggested in the pathogenesis of ulcerative colitis; however, it has not been extensively studied whether voluntary exercise can ameliorate that disorder. We explored the effect of moderate exercise (i.e., voluntary wheel running) on the disease activity index (DAI), colonic blood flow (CBF), plasma irisin and adiponectin levels and real-time PCR expression of proinflammatory markers in mesenteric fat in mice with 2,4,6-trinitrobenzenesulfonic acid (TNBS) colitis fed a high-fat diet (HFD) compared to those on a standard chow diet (SD). Macroscopic and microscopic colitis in sedentary SD mice was accompanied by a significant fall in CBF, some increase in colonic tissue weight and a significant increase in the plasma levels of tumour necrosis factor-alpha (TNF-α), IL-6, monocyte chemotactic protein 1 (MCP-1) and IL-13 (p < 0.05). In sedentary HFD mice, colonic lesions were aggravated, colonic tissue weight increased and the plasma TNF-α, IL-6, MCP-1, IL-1β and leptin levels significantly increased. Simultaneously, a significant decrease in the plasma irisin and adiponectin levels was observed in comparison with SD mice (p < 0.05). Exercise significantly decreased macroscopic and microscopic colitis, substantially increased CBF and attenuated the plasma TNF-α, IL-6, MCP-1, IL-1β and leptin levels while raising the plasma irisin and the plasma and WAT concentrations of adiponectin in HFD mice (p < 0.05). We conclude that: (1) experimental colitis is exacerbated in HFD mice, possibly due to a fall in colonic microcirculation and an increase in the plasma and mesenteric fat content of proinflammatory biomarkers; and (2) voluntary physical activity can attenuate the severity of colonic damage in mice fed a HFD through the release of protective irisin and restoration of plasma adiponectin.

Soluble plasma proteins ST2 and CD163 as early biomarkers of nephropathy in Swedish patients with diabetes, 15-34 years of age: a prospective cohort study

BACKGROUND

The aim of this study was to investigate plasma levels of sST2 and sCD163 to determine whether they at an early stage could predict development of diabetic nephropathy and/or diabetic retinopathy in patients at clinical onset.

METHODS

Patients diagnosed with diabetes mellitus at age 15-34 years between 1987 and 1988 (n = 220) were included. Data such as BMI, smoking, HbA1c and islet cell antibodies were collected at time of diagnosis. Within the 10 year follow-up period, 112 patients (51%) developed following diabetes related complications; retinopathy (n = 91), nephropathy (n = 12) or both (n = 9). Plasma concentrations of sST2 and sCD163 were measured at time of diagnosis and levels compared between different complication groups.

RESULTS

Plasma levels of sST2 were significantly higher in patients who later developed nephropathy (n = 21; 1012 [773-1493] pg/ml) compared to those who did not (n = 199; 723 [449-1084] pg/ml; p = 0.006). A tendency for higher plasma levels of sCD163 was observed but not statistically significant (p = 0.058).

CONCLUSIONS

sST2 and sCD163 show promise as potential biomarkers for the development of nephropathy already at clinical onset. sST2 and/or sCD163 could possibly be part of a biomarker panel aimed to find patients at high risk of developing nephropathy. Both markers need to be investigated in a larger prospective study.

The role of soluble tumor necrosis factor like weak inducer of apoptosis and interleukin-17A in the etiopathogenesis of celiac disease: A cross-sectional study

Our aim in this study was to determine soluble tumor necrosis factor (TNF)-like weak inducer of apoptosis (sTWEAK) and interleukin-17A (IL-17A) levels in celiac disease, and their association with the gluten diet and autoantibodies. Eighty patients with celiac diagnosis and 80 healthy control individuals with similar age, gender and body mass index to the patient group were included in the study. Serum sTWEAK and IL-17A levels were measured by the serum enzyme-linked immunosorbent assay kit. The median IL-17A (117.5 pg/mL vs. 56.7 pg/mL; P = 0.001) level in celiac patients was higher than in the control group, while the median sTWEAK (543 pg/mL vs. 643 pg/mL; P = 0.016) level in patients was determined to be lower. In the patient group, patients who complied with the gluten diet had a lower level of median IL-17A (98.1 pg/mL vs. 197.5 pg/mL; P = 0.034) and a higher level of sTWEAK (606 pg/mL vs. 522.8 pg/mL; P = 0.031) than those who did not adhere. Furthermore, the IL-17A level was higher and the sTWEAK level was lower in celiac patients with positive antibody than those with negative antibody. A positive correlation was determined among anti-gliadin antibody IgA, anti-gliadin antibody IgG, anti-tissue transglutaminase IgG levels and the IL-17A level, and a negative correlation was determined with the sTWEAK level. In celiac disease, the sTWEAK and IL-17A levels differ between patients who cannot adapt to the gluten diet and who are autoantibody positive, and patients who adapt to the diet and are autoantibody negative. We believe that sTWEAK and IL-17A are associated with the inflammation in celiac pathogenesis.

HIV-1/HAART-Related Lipodystrophy Syndrome (HALS) Is Associated with Decreased Circulating sTWEAK Levels

BACKGROUND AND OBJECTIVES

Obesity and HIV-1/HAART-associated lipodystrophy syndrome (HALS) share clinical, pathological and mechanistic features. Tumor necrosis factor-like weak inducer of apoptosis (TWEAK) is a multifunctional cytokine that plays an important role in obesity and related diseases. We sought to explore the relationship between HALS and circulating levels of soluble (s) TWEAK and its scavenger receptor sCD163.

METHODS

This was a cross-sectional multicenter study of 120 HIV-1-infected patients treated with a stable HAART regimen; 56 with overt HALS and 64 without HALS. Epidemiological and clinical variables were determined. Serum levels of sTWEAK and sCD163 levels were measured by ELISA. Results were analyzed with Student's t-test, Mann-Whitney U and χ2 test. Pearson and Spearman correlation were used to estimate the strength of association between variables.

RESULTS

Circulating sTWEAK was significantly decreased in HALS patients compared with non-HALS patients (2.81±0.2 vs. 2.94±0.28 pg/mL, p = 0.018). No changes were observed in sCD163 levels in the studied cohorts. On multivariate analysis, a lower log sTWEAK concentration was independently associated with the presence of HALS (OR 0.027, 95% CI 0.001-0.521, p = 0.027).

CONCLUSIONS

HALS is associated with decreased sTWEAK levels.

The association of high sCD163/sTWEAK ratio with cardiovascular disease in hemodialysis patients

PURPOSE

Cardiovascular disease (CVD) is the most common cause of death in hemodialysis (HD) patients. Transmembrane proteins that circulate as soluble form such as tumor necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK) and CD163 have been proposed in previous studies as CVD biomarkers in chronic kidney disease patients. In HD patients, since studies are scarce, the role of these proteins is not completely understood. We tested the hypothesis that sTWEAK, sCD163 or sCD163/sTWEAK ratio could be associated with cardiovascular disease in HD patients.

METHODS

We recorded current clinical and biological data, and we measured sTWEAK and sCD163 serum levels by ELISA in 70 hemodialysis patients. Univariate analysis and multivariate (logistic regression) analysis were used to identify the relation between sTWEAK, sCD163 and sCD163/sTWEAK ratio and CVD.

RESULTS

In univariate analysis, CVD in HD patients is associated with higher sCD163/sTWEAK ratio (p = 0.04), sCD163 (p = 0.07), CRP (p = 0.04), age (p = 0.07), smoking (p = 0.09) and vascular calcifications (p = 0.10). In multivariate analysis, only logarithm of sCD163/sTWEAK ratio (p = 0.04) and smoking (p = 0.03) was significantly associated with CVD. The levels of these molecules and their ratio were correlated with atherosclerosis risk factors: diabetes mellitus, high fasting glucose, tricipital skinfold thickness and CRP as well as (for sCD163/sTWEAK) intravenous iron therapy.

CONCLUSIONS

Cardiovascular disease is associated with increased sCD163/sTWEAK ratio. To our knowledge, this is the first report about this relationship in HD patients.

The relationship between asymptomatic organ damage, and serum soluble tumor necrosis factor-like weak inducer of apoptosis (sTWEAK) and Interleukin-17A (IL-17A) levels in non-diabetic hypertensive patients

Background

This study aimed to measure the serum soluble tumor necrosis factor-like weak inducer of apoptosis (sTWEAK) and interleukin-17A (IL-17A) levels in hypertensive patients with/without asymptomatic organ damage (AOD), as well as to determine the relationship between the serum sTWEAK and IL17-A levels, and carotid intima media thickness (CIMT), proteinuria, retinopathy, and the left ventricle mass index (LVMI).

Methods

The study included 159 patients diagnosed with and followed-up for primary hypertension (HT); 79 of the patients had AOD (61 female and 18 male) and 80 did not (52 female and 28 male). sTWEAK and IL-17A levels were measured in all patients.

Results

The sTWEAK level was significantly lower in the patients with AOD than in those without AOD (858.4 pg/mL vs. 1151.58 pg/mL, P = 0.001). The sTWEAK level was negatively correlated with the mean microalbuminuria level and LVMI. The median IL-17A level was significantly higher in the patients with AOD than in those without AOD (2.34 pg/mL vs. 1.80 pg/mL, P = 0.001). There was a positive correlation between mean IL-17A level, and mean microalbuminuria level, CIMT, and LVMI. Multivariate logistic regression analysis showed that patient age, sTWEAK level, and mean 24-h systolic blood pressure were predictors of AOD.

Conclusions

The sTWEAK level was lower and IL-17A level was higher in the patients with AOD. It remains unknown if sTWEAK and IL-17A play a role in the pathophysiology of AOD. Prospective observational studies are needed to determine the precise role of sTWEAK and IL-17A in the development of target organ damage.

Twist 1 regulates the expression of PPARγ during hormone-induced 3T3-L1 preadipocyte differentiation: a possible role in obesity and associated diseases

BACKGROUND

Twist 1 is highly expressed in adipose tissue and has been associated with obesity and related disorders. However, the molecular function of Twist 1 in adipose tissue is unclear. Twist 1 has been implicated in cell lineage determination and differentiation. Therefore, we investigated both the role of Twist 1 in adipocyte precursor mobilization and the relationship of Twist 1 with other molecular determinants of adipocyte differentiation.

METHODS

We examined Twist 1 mRNA and protein expression in subcutaneous adipose tissues from diet-induced obese C57/BL6 mice and Wistar rats and in obese patients undergoing liposuction or adipose transplant surgeries. Twist 1 expression was measured on days 0, 2, 4, 8, and 12 of 3T3-L1 differentiation in vitro. The role of Twist 1 in adipogenesis was explored using retroviral interference of Twist 1 expression. Adipokine secretion was evaluated using a RayBio® Biotin Label-based Adipokine Array.

RESULTS

Twist 1 mRNA and protein levels were reduced in diet-induced obese mice and rats and in obese humans. Twist 1 was upregulated during 3T3-L1 preadipocyte differentiation in vitro, beginning from the fourth day of differentiation induction. Retroviral interference of Twist 1 expression did not significantly impair lipid formation; however, retroviral interference induced PPARγ mRNA and protein expression on day 4 of differentiation induction. Adipokine array analyses revealed increased secretion of CXCR4 (19.55-fold), VEGFR1 (92.13-fold), L-21 R (63.55-fold), and IL-12 R beta 1 (59.66-fold) and decreased secretion of VEGFR3 (0.01-fold), TSLP R (0.071-fold), MIP-1 gamma (0.069-fold), TNF RI/TNFRSF1A (0.09-fold), and MFG-E8 (0.06-fold).

CONCLUSIONS

Twist 1 is a regulator of adipocyte gene expression although it is not likely to regulate differentiation. We identified PPARγ as a potential target of Twist 1 and found variation in the secretion of multiple adipokines, which might indicate a prospective mechanism linking Twist 1 expression with obesity or associated diseases.

Deletion of TNF-like weak inducer of apoptosis (TWEAK) protects mice from adipose and systemic impacts of severe obesity

OBJECTIVE

To investigate the role of TNF-like weak inducer of apoptosis (TWEAK) in pathological adipose tissue (AT) remodeling and complications of obesity.

METHODS

Wild type (WT) and TWEAK knockout (KO) mice were fed normal diet (ND) or a high fat diet (HFD) for up to 17 weeks. Adipocyte death was induced using an established transgenic mouse model of inducible adipocyte apoptosis (FAT-ATTAC). Metabolic, biochemical, histologic, and flow cytometric analyses were performed.

RESULTS

TWEAK and its receptor, fibroblast growth factor-inducible molecule 14 (Fn14) were upregulated in gonadal (g)AT of WT mice after HFD week 4 and 24 h after induction of adipocyte apoptosis. Phenotypes of KO and WT mouse were indistinguishable through HFD week 8. However, at week 17 obese KO mice had ∼30% larger gAT adipocytes and gAT mass than WT mice, coincident with reduced adipocyte death, enhanced insulin signaling, Th2/M2 immune skewing, fewer thick collagen fibers, and altered expression of extracellular matrix constituents and modulators that is consistent with reduced fibrosis and larger adipocytes. KO mice were less steatotic and became more insulin sensitive and glucose tolerant than WT mice after HFD week 12.

CONCLUSION

TWEAK constrains "healthy" gAT expansion and promotes metabolic complications in severe obesity.