Selected Factors of Vascular Changes: The Potential Pathological Processes Underlying Primary Headaches in Children

Background: The prevalence, social consequences and complicated pathogenesis make headaches in children a significant clinical issue. Studies in adults suggest that primary headaches could be the first sign of atherosclerosis and platelet aggregation. Aim: To analyze the blood levels of selected biomarkers of vascular changes potentially associated with a higher risk of atherosclerosis in children with primary headaches. Methods: The medical family history, brain-derived neurotrophic factor (BDNF), soluble CD40 ligands (sCD40L), endothelial plasminogen activator inhibitor (PAI I), vascular endothelial growth factor (VEGF) and intima-media thickness (IMT) measurements were performed in the 83 children (52 with primary headaches, 31 controls). Selected factors were compared with basic laboratory parameters that are potentially related to atherosclerosis: C-reactive protein (CRP) and lipid concentration. Results: There were no significant differences in biomarkers of vascular changes in the study group and controls in general. In the study group, boys had a higher BDNF level than girls (p = 0.046). Normal-weight migraine patients had significantly higher PAI-I levels than controls (p = 0.034). A positive correlation between PAI-1 and triglycerides (TG) was observed. IMT did not differ between children with primary headaches and controls; however, IMT showed a positive correlation with BMI z-score and TG. Children with headaches had, more often, a positive family history of cardiovascular disease (p = 0.049). Conclusions: There were no clear clinical changes indicative of atherosclerosis in the study population. However, some trends are visible. Primary headaches are more often related to a family history of cardiovascular diseases. IMT is associated with TG levels and BMI z-score. The measured biomarkers of vascular changes show mutual relations.

Headache in Children: Selected Factors of Vascular Changes Involved in Underlying Processes of Idiopathic Headaches

Headaches are common complaints in children. The International Classification of Headache Disorders, 3^rd edition (beta version), defines more than 280 types of headaches. Primary headaches refer to independent conditions that cause pain and include migraine, tension-type headaches (TTH), and trigeminal autonomic cephalalgias (TACs). Several agents are involved in the pathogenesis of headaches. The factors associated with predisposition to atherosclerosis seem to be particularly important from the clinical point of view. The influence of obesity on the incidence of headaches has been well established. Moreover, idiopathic headaches, especially migraine, are thought to be one of the first signs of disorders in lipid metabolism and atherosclerosis. The risk of migraine increases with increasing obesity in children. Another factor that seems to be involved in both obesity and headaches is the adiponectin level. Recent data also suggest new potential risk factors for atherosclerosis and platelet aggregation such as brain-derived neurotrophic factor (BDNF), sCD40L (soluble CD40 ligand), serpin E1/PAI I (endothelial plasminogen activator inhibitor), and vascular endothelial growth factor (VEGF). However, their role is controversial because the results of clinical studies are often inconsistent. This review presents the current knowledge on the potential markers of atherosclerosis and platelet aggregation, which may be associated with primary headaches.

Obesity is associated with impaired responsiveness to once-daily low-dose aspirin and in vivo platelet activation

BACKGROUND

The prevalence and degree of obesity is rising worldwide, increases cardiovascular risk, modifies body composition and organ function, and potentially affects the pharmacokinetics and/or pharmacodynamics of drugs.

OBJECTIVES

To investigate the pharmacodynamics of once-daily low-dose aspirin in healthy obese subjects, and to assess whether body weight (BW) and body mass index (BMI) affect the pharmacology of aspirin.

PATIENTS/METHODS

Otherwise healthy, obese (BMI > 30 kg/m2 ) subjects were studied before and after 3-4 weeks of 100-mg once-daily aspirin intake. Aspirin pharmacodynamics were assessed according to serum thromboxane (TX) B2 levels measured at 4 hours, 24 hours (i.e., posologic interval) and 48 hours after the last witnessed intake; age-matched and sex-matched non-obese controls were included. A previously calibrated pharmacokinetic/pharmacodynamic in silico model of aspirin was used to fit serum TXB2 data from obese subjects. At baseline, the major urinary TXA2 and prostacyclin metabolites, urinary isoprostane and plasma inflammatory biomarkers were measured.

RESULTS

In 16 obese subjects (aged 47 ± 11 years; BMI of 39.4 ± 5.1 kg/m2 ), residual serum TXB2 values between 4 and 48 hours after aspirin intake were increased 3- to 5-fold as compared with controls. At 24 hours, the residual serum TXB2 level was log-linearly associated with body size over a wide range of BMI and BW values, without any apparent threshold. The in silico model predicted that reduced aspirin bioavailability would be inversely related to body size and rescued by 200 mg of aspirin once daily or 85 mg twice daily. Baseline urinary TXA2 metabolite, isoprostane and plasma C-reactive protein levels were significantly increased in obese subjects.

CONCLUSIONS

Obesity is associated with impaired aspirin responsiveness, largely because of body size. Impaired inhibition of platelet activation by conventional low-dose aspirin may affect antithrombotic efficacy.

Severe obesity and bariatric surgery alter the platelet mRNA profile

Mechanisms explaining the relationship between obesity and cardiovascular disease (CVD) are needed. Despite growing recognition of the importance of the anucleate platelet transcriptome, low levels of RNA in platelets make assessment difficult. We sought to perform unbiased platelet RNA profiling in obesity by performing a prospective study of severe obesity and weight loss via bariatric surgery on platelet characteristics and mRNA profile in 26 pre-menopausal, non-diabetic women (31.6 ± 8.4 years; BMI 43.0 ± 6.5 kg/m²) who underwent sleeve gastrectomy. Totally, 10 women of similar age with normal BMI served as controls. Platelet activation via flow cytometry was assessed before and after surgery. RNA-sequencing (RNAseq) was performed on platelet isolates from a subset of 13 subjects (eight obese women and five normal-BMI subjects). Platelet count, size, and age did not differ between control and obese women. However, platelet surface P-selectin and CD40 were higher in obesity. RNAseq demonstrated 629 differentially abundant transcripts in obesity. Notably, S100A9 and AGER, established markers of cardiovascular risk, were two of the most highly upregulated transcripts (each > 2.5 fold). At 6 months post-operatively, subjects lost 26.1 ± 5.8% body weight and inducible platelet P-selectin expression was reduced. Expression of 170 transcripts was affected by surgery, but only a small fraction (46/629) were genes found altered in obesity. We demonstrate that obesity is associated with an altered platelet transcriptome and increased platelet activation, which is partly attenuated by bariatric surgery. These observations suggest that platelets may contribute to increased cardiovascular risk in obesity through a variety of mechanisms.

Lipid levels and selected biomarkers of vascular changes in children with idiopathic headaches - a preliminary report

INTRODUCTION

Elevated lipid concentrations were observed in adults with headaches. However, studies in children are scarce. Recent data suggest new potential risk factors for atherosclerosis, which may be associated with headaches. The aim of the study was to analyse the blood levels of lipids and new markers of atherosclerosis in children with idiopathic headaches.

MATERIAL AND METHODS

The study population comprised 65 children (39 with idiopathic headaches and 26 healthy children). Total cholesterol (TC), high-density lipoprotein (HDL), low-density lipoprotein (LDL) cholesterol and triacylglycerol (TG) levels were measured in every patient. Brain-derived neurotrophic factor (BDNF), soluble CD40 ligand (sCD40L), endothelial plasminogen activator inhibitor (serpin E1/PAI I) and vascular endothelial growth factor (VEGF) blood level measurements were performed in 34 children.

RESULTS

Children with headaches had higher BMI z-scores (0.2 vs. -1.14; p = 0.006). TC level was lower in patients with headaches (121.04 mg/dl vs. 146.87 mg/dl, p = 0.019). No differences in concentrations of TG, HDL or LDL were found. BDNF was significantly higher in the studied group (171.57 pg/ml vs. 64.04 pg/ml, p = 0.012). The VEGF was higher in boys with headaches than in girls (368.27 pg/ml vs. 142.86 pg/ml, p = 0.011). There were no differences in levels of VEGF, sCD40L or PAI-1 between groups.

CONCLUSIONS

Children with headaches have lower total cholesterol and higher BDNF levels than controls. No significant difference in levels of triacylglycerols, HDL cholesterol, LDL cholesterol, VEGF, sCD40L or PAI-1 was found between children with headaches and controls.

Deficiency of T cell CD40L has minor beneficial effects on obesity-induced metabolic dysfunction

OBJECTIVE

Obesity-associated metabolic dysfunction increases the risk of multiple diseases such as type 2 diabetes and cardiovascular disease. The importance of the co-stimulatory CD40-CD40L dyad in diet-induced obesity (DIO), with opposing phenotypes arising when either the receptor (aggravating) or the ligand (protective) is deleted, has been described previously. The functions of CD40 and CD40L are cell type dependent. As co-stimulation via T cell-mediated CD40L is essential for driving inflammation, we here investigate the role of T cell CD40L in DIO.

RESEARCH DESIGN AND METHODS

CD4CreCD40L^fl/fl mice on a C57BL/6 background were generated and subjected to DIO by administration of 15 weeks of high fat diet (HFD).

RESULTS

HFD-fed CD4CreCD40L^fl/fl mice had similar weight gain, adipocyte sizes, plasma cholesterol and triglyceride levels as their wild-type (WT) counterparts. Insulin and glucose tolerance were comparable, although CD4CreCD40L^fl/fl mice did have a decreased plasma insulin concentration, suggesting a minor improvement of insulin resistance. Furthermore, although the degree of hepatosteatosis was similar in both genotypes, the gene expression of fatty acid synthase 1 and ATP-citrate lyase had decreased, whereas expression of peroxisome proliferator-activated receptor-α had increased in livers of CD4CreCD40L^fl/fl mice, suggesting decreased hepatic lipid uptake in absence of T cell CD40L.Moreover, CD4CreCD40L^fl/fl mice displayed significantly lower numbers of effector memory CD4⁺ T cells and regulatory T cells in blood and lymphoid organs compared with WT. However, immune cell composition and inflammatory status of the adipose tissue was similar in CD4CreCD40L^fl/fl and WT mice.

CONCLUSIONS

T cell CD40L deficiency results in a minor improvement of insulin sensitivity and hepatic steatosis in DIO, despite the strong decrease in effector T cells and regulatory T cells in blood and lymphoid organs. Our data indicate that other CD40L-expressing cell types are more relevant in the pathogenesis of obesity-associated metabolic dysfunction.

Contribution of Adipose Tissue Inflammation to the Development of Type 2 Diabetes Mellitus

The objective of this comprehensive review is to summarize and discuss the available evidence of how adipose tissue inflammation affects insulin sensitivity and glucose tolerance. Low-grade, chronic adipose tissue inflammation is characterized by infiltration of macrophages and other immune cell populations into adipose tissue, and a shift toward more proinflammatory subtypes of leukocytes. The infiltration of proinflammatory cells in adipose tissue is associated with an increased production of key chemokines such as C-C motif chemokine ligand 2, proinflammatory cytokines including tumor necrosis factor α and interleukins 1β and 6 as well as reduced expression of the key insulin-sensitizing adipokine, adiponectin. In both rodent models and humans, adipose tissue inflammation is consistently associated with excess fat mass and insulin resistance. In humans, associations with insulin resistance are stronger and more consistent for inflammation in visceral as opposed to subcutaneous fat. Further, genetic alterations in mouse models of obesity that reduce adipose tissue inflammation are-almost without exception-associated with improved insulin sensitivity. However, a dissociation between adipose tissue inflammation and insulin resistance can be observed in very few rodent models of obesity as well as in humans following bariatric surgery- or low-calorie-diet-induced weight loss, illustrating that the etiology of insulin resistance is multifactorial. Taken together, adipose tissue inflammation is a key factor in the development of insulin resistance and type 2 diabetes in obesity, along with other factors that likely include inflammation and fat accumulation in other metabolically active tissues. © 2019 American Physiological Society. Compr Physiol 9:1-58, 2019.

Heterozygosity for the rs696217 SNP in the Preproghrelin Gene Predicts Weight Loss After Bariatric Surgery in Severely Obese Individuals

BACKGROUND

Several patients encompass a scarce weight loss after Roux-en-Y gastric bypass (RYGB). As such event is not related to surgical complications, finding markers able to identify "well responders" and to predict weight loss outcome is clinically relevant. Ghrelin regulates appetite and energy balance. Common single nucleotide polymorphisms (SNPs) in its encoding genes have been associated with body weight regulation. Other peptides involved in satiety modulation, like the CD40/CD40L complex, are less explored.

METHODS

One hundred, otherwise healthy, obese subjects (aged 45 ± 11 years, 65 females, BMI 48.0 ± 0.7 kg/m²) were sequentially enrolled in years 2014-2015. SNPs rs2241766 for adiponectin gene, rs490683 for ghrelin receptor, rs696217 and rs27647 for the preproghrelin/ghrelin gene, and rs1126535 for the CD40L gene were determined on DNA extracted from circulating lymphomonocytes. Patients were reevaluated at 6 (n = 100), 26 (n = 91), and 52 weeks (n = 79) after RYGB.

RESULTS

Subjects carrying the rs696217 T allele encompassed a significantly greater reduction in BMI 52 weeks after surgery (GG vs GT 30.5 ± 1.1 vs 38.1 ± 2.1 %; p < 0.001). Carrying the rs1126535 C allele in the CD40L gene was associated with a significantly lower BMI reduction at week 52 (TT vs CT 33.2 ± 1.1 vs 28.1 ± 2.3 %, p = 0.049). rs490683 and rs27647 SNPs of ghrelin and rs2241766 for adiponectin gene did not show any difference between carriers and non-carriers of the mutant allele.

CONCLUSION

Carrying a G to T substitution in rs696217 (preproghrelin gene) seems to mark a successful weight loss outcome; we also report for the first time that the rs1126535 C allele (CD40L gene) may predict a worse response to bariatric surgery.

An inflammatory link in atherosclerosis and obesity. Co-stimulatory molecules

Atherosclerosis and obesity-induced metabolic dysfunction are lipid-driven inflammatory pathologies responsible for a major part of cardiovascular complications. Immune cell activation as well as interactions between the different immune cells is dependent on and controlled by a variety of co-stimulatory signals. These co-stimulatory signals can either aggravate or ameliorate the disease depending on the stage of the disease, the cell-types involved and the signal transduction cascades initiated. This review focuses on the diverse roles of the most established co-stimulatory molecules of the B7 and Tumor Necrosis Factor Receptor (TNFR) families, ie the CD28/CTLA4-CD80/CD86 and CD40L/CD40 dyads in the pathogenesis of atherosclerosis and obesity. In addition, we will explore their potential as therapeutic targets in both atherosclerosis and obesity.

Novel biomarkers of periodontitis and/or obesity in saliva-An exploratory analysis

OBJECTIVE

Recent studies point to the clinical and research utility of saliva as a valuable diagnostic aid for monitoring periodontal health. The objectives of this study were to detect novel biomarkers attributed to chronic inflammation in saliva and to determine if the levels of these markers correlate with severity of periodontitis and with standard obesity measures in participants in a periodontal maintenance program.

DESIGN

In this cross-sectional assessment of 63 participants, unstimulated whole saliva was collected after recording anthropometric and clinical parameters of obesity and periodontitis, respectively. The levels of interleukin-1 receptor antagonist (IL-1ra), sCD40L, granzyme B and alpha-fetoprotein (AFP) in saliva were determined using multiplex proteomic immunoassays. The correlation between the four tested biomarker concentrations and obesity/periodontal measures was determined.

RESULTS

Positive correlation between fat% and granzyme B levels (r=0.292; p=0.020) and negative correlation between BMI and sCD40L (r=0.256; p=0.043) was observed. In addition, positive correlation between severity of periodontal disease and levels of IL1-ra (r=0.253; p=0.046) and negative correlation between periodontitis severity and sCD40L salivary levels (r=0.272; p=0.031) was noted. None of the above correlations remained statistically significant after multiple comparisons adjustment. After adjustment for clinical covariates, the relationship between sCD40L and periodontal severity remained suggestive (p=0.081).

CONCLUSIONS

Levels of four novel biomarkers of periodontitis were detectable in saliva of subjects enrolled in a periodontal maintenance program. Prospective studies with larger sample sizes and other populations are warranted to explore the diagnostic applicability of these markers.

Immune cell crosstalk in obesity: a key role for costimulation?

In the past two decades, numerous experimental and clinical studies have established the importance of inflammation and immunity in the development of obesity and its metabolic complications, including insulin resistance and type 2 diabetes mellitus. In this context, T cells orchestrate inflammatory processes in metabolic organs, such as the adipose tissue (AT) and liver, thereby mediating obesity-related metabolic deterioration. Costimulatory molecules, which are present on antigen-presenting cells and naïve T cells in the AT, are known to mediate the crosstalk between the adaptive and innate immune system and to direct T-cell responses in inflammation. In this Perspectives in Diabetes article, we highlight the newest insights in immune cell interactions in obesity and discuss the role of costimulatory dyads in its pathogenesis. Moreover, the potential of therapeutic strategies that target costimulatory molecules in the metabolic syndrome is explored.

Blocking CD40-TRAF6 interactions by small-molecule inhibitor 6860766 ameliorates the complications of diet-induced obesity in mice

BACKGROUND

Immune processes contribute to the development of obesity and its complications, such as insulin resistance, type 2 diabetes mellitus and cardiovascular disease. Approaches that target the inflammatory response are promising therapeutic strategies for obesity. In this context, we recently demonstrated that the interaction between the costimulatory protein CD40 and its downstream adaptor protein tumor necrosis factor receptor-associated factor 6 (TRAF6) promotes adipose tissue inflammation, insulin resistance and hepatic steatosis in mice in the course of diet-induced obesity (DIO).

METHODS

Here we evaluated the effects of a small-molecule inhibitor (SMI) of the CD40-TRAF6 interaction, SMI 6860766, on the development of obesity and its complications in mice that were subjected to DIO.

RESULTS

Treatment with SMI 6860766 did not result in differences in weight gain, but improved glucose tolerance. Moreover, SMI 6860766 treatment reduced the amount of CD45(+) leucocytes in the epididymal adipose tissue by 69%. Especially, the number of adipose tissue CD4(+) and CD8(+) T cells, as well as macrophages, was significantly decreased.

CONCLUSIONS

Our results indicate that small-molecule-mediated inhibition of the CD40-TRAF6 interaction is a promising therapeutic strategy for the treatment of metabolic complications of obesity by improving glucose tolerance, by reducing the accumulation of immune cells to the adipose tissue and by skewing of the immune response towards a more anti-inflammatory profile.