Microvascular Endothelial Dysfunction in Human Obesity: Role of TNF-α

Coexistence of high visceral fat area and sarcopenia is associated with atherosclerotic markers in old-old patients with diabetes: A cross-sectional study

AIMS/INTRODUCTION

To investigate whether sarcopenic obesity is associated with the progression of atherosclerotic lesions in older patients with diabetes and to identify the obesity components of sarcopenic obesity that best reflect atherosclerosis.

MATERIALS AND METHODS

In 118 inpatients aged ≥75 years with diabetes mellitus, sarcopenia defined as a low skeletal muscle mass and low grip strength was assessed, and sarcopenia coexisting with a high body-fat percentage or visceral fat area was defined as sarcopenic obesity. Correlations between the obesity components and atherosclerotic markers, including the carotid intima-media thickness, were analyzed; the intima-media thickness was analyzed in four groups with and without obesity and sarcopenia, and a multiple linear regression analysis adjusted for covariates was conducted to investigate whether sarcopenic obesity was independently associated with the intima-media thickness.

RESULTS

The visceral fat area and intima-media thickness showed positive correlations in the overall patients (P = 0.032) and the sarcopenia (P = 0.016) group but showed no associations in participants without sarcopenia. The intima-media thickness in the group showing sarcopenia with a high visceral fat area was significantly higher than that in the control group (P = 0.012). Sarcopenic obesity defined by a high body-fat percentage and high visceral fat area was independently associated with the intima-media thickness even after adjusting for age, sex, and atherogenic risk factors. However, sarcopenic obesity defined by a high visceral fat area was more strongly associated with the intima-media thickness (β = 0.384, P = 0.002) than that defined by the high body-fat percentage (β = 0.237, P = 0.068).

CONCLUSIONS

Sarcopenic obesity, especially that defined by visceral fat accumulation, reflected the risk of atherosclerotic lesion progression in older patients with diabetes.

Insulin Dynamics and Pathophysiology in Youth-Onset Type 2 Diabetes

Youth-onset type 2 diabetes (T2D) is increasing around the globe. The mounting disease burden of youth-onset T2D portends substantial consequences for the health outcomes of young people and for health care systems. The pathophysiology of this condition is characterized by insulin resistance and initial insulin hypersecretion ± an inherent insulin secretory defect, with progressive loss of stimulated insulin secretion leading to pancreatic β-cell failure. Research studies focusing on youth-onset T2D have illuminated key differences for youth- vs adult-onset T2D, with youth having more profound insulin resistance and quicker progression to loss of sufficient insulin secretion to maintain euglycemia. There is a need for therapies that are targeted to improve both insulin resistance and, importantly, maintain sufficient insulin secretory function over the lifespan in youth-onset T2D.

Distinguishing pathophysiological features of heart failure with reduced and preserved ejection fraction: A comparative analysis of two mouse models

Heart failure (HF) is a heterogeneous condition that can be categorized according to the left ventricular ejection fraction (EF) into HF with reduced (HFrEF) or preserved (HFpEF) EF. Although HFrEF and HFpEF share some common clinical manifestations, the mechanisms underlying each phenotype are often found to be distinct. Identifying shared and divergent pathophysiological features might expand our insights on HF pathophysiology and assist the search for therapies for each HF subtype. In this study, we evaluated and contrasted two new murine models of non-ischaemic HFrEF and cardiometabolic HFpEF in terms of myocardial structure, left ventricular function, gene expression, cardiomyocyte calcium handling, mitochondrial polarization and protein acetylation in a head-to-head fashion. We found that in conditions of similar haemodynamic stress, the HFrEF myocardium underwent a more pronounced hypertrophic and fibrotic remodelling, whereas inflammation was greater in the HFpEF myocardium. We observed opposing features on calcium release, which was diminished in the HFrEF cardiomyocyte but enhanced in the HFpEF cardiomyocyte. Mitochondria were less polarized in both HFrEF and HFpEF cardiomyocytes, reflecting similarly impaired metabolic capacity. Hyperacetylation of cardiac proteins was observed in both models, but it was more accentuated in the HFpEF heart. Despite shared features, unique triggering mechanisms (neurohormonal overactivation in HFrEF vs. inflammation in HFpEF) appear to determine the distinct phenotypes of HF. The findings of the present research stress the need for further exploration of the differential mechanisms underlying each HF subtype, because they might require specific therapeutic interventions. KEY POINTS: The mechanisms underlying heart failure with either reduced (HFrEF) or preserved (HFpEF) ejection fraction are often found to be different. Previous studies comparing pathophysiological traits between HFrEF and HFpEF have been conducted on animals of different ages and strains. The present research contrasted two age-matched mouse models of non-ischaemic HFrEF and cardiometabolic HFpEF to uncover divergent and shared features. We found that upon similar haemodynamic stress, the HFrEF heart experienced a more pronounced hypertrophic and fibrotic remodelling, whereas inflammation appeared to be greater in the HFpEF myocardium. Calcium release was diminished in the HFrEF cardiomyocyte and enhanced in the HFpEF cardiomyocyte. Mitochondria were comparably less polarized in both HFrEF and HFpEF myocytes. Hyperacetylation of proteins was common to both models, but stronger in the HFpEF heart. Casting light on common and distinguishing features might ease the quest for phenotype-specific therapies for heart failure patients.

Diet-induced metabolic and immune impairments are sex-specifically modulated by soluble TNF signaling in the 5xFAD mouse model of Alzheimer's disease

Emerging evidence indicates that high-fat, high carbohydrate diet (HFHC) impacts central pathological features of Alzheimer's disease (AD) across both human incidences and animal models. However, the mechanisms underlying this association are poorly understood. Here, we identify compartment-specific metabolic and inflammatory dysregulations that are induced by HFHC diet in the 5xFAD mouse model of AD pathology. We observe that both male and female 5xFAD mice display exacerbated adiposity, cholesterolemia, and dysregulated insulin signaling. Independent of biological sex, HFHC diet also resulted in altered inflammatory cytokine profiles across the gastrointestinal, circulating, and central nervous systems (CNS) compartments demonstrating region-specific impacts of metabolic inflammation. Interestingly, inhibiting the inflammatory cytokine, soluble tumor necrosis factor (TNF) with the brain-permeant soluble TNF inhibitor XPro1595 was able to restore aspects of HFHC-induced metabolic inflammation, but only in male mice. Targeted transcriptomics of CNS regions revealed that inhibition of soluble TNF was sufficient to alter expression of hippocampal and cortical genes associated with beneficial immune and metabolic responses. Collectively, these results suggest that HFHC diet impairs metabolic and inflammatory pathways in an AD-relevant genotype and that soluble TNF has sex-dependent roles in modulating these pathways across anatomical compartments. Modulation of energy homeostasis and inflammation may provide new therapeutic avenues for AD.

Environmental dose of 16 priority-controlled PAHs induce endothelial dysfunction: An in vivo and in vitro study

Polycyclic aromatic hydrocarbons (PAHs) exposure is related to the occurrence of cardiovascular diseases (CVDs). Endothelial dysfunction is considered an initial event of CVDs. To confirm the relationship of PAHs exposure with endothelial dysfunction, 8-week-old male SD rats and primary human umbilical vein endothelial cells (HUVECs) were co-treated with environmental doses of 16 priority-controlled PAHs for 90 d and 48 h, respectively. Results showed that 10× PAHs exposure remarkably raised tumor necrosis factor-α and malonaldehyde levels in rat serum (p < 0.05), but had no effects on interleukin-8 levels and superoxide dismutase activity. The expressions of SIRT1 in HUVECs and rat aorta were attenuated after PAHs treatment. Interestingly, PAHs exposure did not activate the expression of total endothelial nitric oxide synthase (eNOS), but 10× PAHs exposure significantly elevated the expression of phosphorylated eNOS (Ser1177) in HUVECs and repressed it in aortas, accompanied with raised nitrite level both in serum and HUVECs by 48.50-253.70 %. PAHs exposure also led to the augment of endothelin-1 (ET-1) levels by 19.76-38.54 %, angiotensin (Ang II) levels by 20.09-39.69 % in HUVECs, but had no effects on ET-1 and Ang II levels in serum. Additionally, PAHs exposure improved endocan levels both in HUVECs and serum by 305.05-620.48 % and stimulated the THP-1 cells adhered to HUVECs (p < 0.05). After PAHs treatment, the smooth muscle alignment was disordered and the vascular smooth muscle locally proliferated in rat aorta. Notably, the systolic blood pressure of rats exposed to 10× PAHs increased significantly compared with the control ones (131.28 ± 5.20 vs 116.75 ± 5.33 mmHg). In summary, environmental chronic PAHs exposure may result in endothelial dysfunction in SD rats and primary HUVECs. Our research can confirm the cardiovascular damage caused by chronic exposure to PAHs and provide ideas for the prevention or intervention of CVDs affected by environmental factors.

Integration of 16S rRNA sequencing and metabolomics to investigate the modulatory effect of ginsenoside Rb1 on atherosclerosis

Background

/aims: Atherosclerosis (AS) is the common pathological basis of a variety of cardiovascular diseases (CVD), and has become the main cause of human death worldwide, and the incidence is increasing and younger trend. Ginsenoside Rb1 (Rb1), an important monomer component of the traditional Chinese herb ginseng, known for its ability to improve blood lipid disorders and anti-inflammatory. In addition, Rb1 was proved to be an effective treatment for AS. However, the effect of Rb1 on AS remains to be elucidated. The aim of this study was to investigate the mechanisms of Rb1 in ameliorating AS induced by high-fat diet (HFD).

Materials and methods

In this study, we developed an experimental AS model in Sprague-Dawley rats by feeding HFD with intraperitoneal injection of vitamin D3. The potential therapeutic mechanism of Rb1 in AS rats was investigated by detecting the expression of inflammatory factors, microbiome 16S rRNA gene sequencing, short-chain fatty acids (SCFAs) targeted metabolomics and untargeted metabolomics.

Results

Rb1 could effectively alleviate the symptoms of AS and suppress the overexpression of inflammation-related factors. Meanwhile, Rb1 altered gut microbial composition and concentration of SCFAs characterized by Bacteroidetes, Actinobacteria, Lactobacillus, Prevotella, Oscillospira enrichment and Desulfovibrio depletion, accompanied by increased production of acetic acid and propionic acid. Moreover, untargeted metabolomics showed that Rb1 considerably improved faecal metabolite profiles, particularly arachidonic acid metabolism and primary bile acid biosynthesis.

Conclusion

Rb1 ameliorated the HFD-induced AS, and the mechanism is related to improving intestinal metabolic homeostasis and inhibiting systemic inflammation by regulating gut microbiota.

Diet-induced metabolic and immune impairments are sex-specifically modulated by soluble TNF signaling in the 5xFAD mouse model of Alzheimer's disease

Emerging evidence indicates that high-fat, high carbohydrate diet (HFHC) impacts central pathological features of Alzheimer's disease (AD) across both human incidences and animal models. However, the mechanisms underlying this association are poorly understood. Here, we identify compartment-specific metabolic and inflammatory dysregulations that are induced by HFHC diet in the 5xFAD mouse model of AD pathology. We observe that both male and female 5xFAD mice display exacerbated adiposity, cholesterolemia, and dysregulated insulin signaling. Independent of biological sex, HFHC diet also resulted in altered inflammatory cytokine profiles across the gastrointestinal, circulating, and central nervous systems (CNS) compartments demonstrating region-specific impacts of metabolic inflammation. In male mice, we note that HFHC triggered increases in amyloid beta, an observation not seen in female mice. Interestingly, inhibiting the inflammatory cytokine, soluble tumor necrosis factor (TNF) with the brain-permeant soluble TNF inhibitor XPro1595 was able to restore aspects of HFHC-induced metabolic inflammation, but only in male mice. Targeted transcriptomics of CNS regions revealed that inhibition of soluble TNF was sufficient to alter expression of hippocampal and cortical genes associated with beneficial immune and metabolic responses. Collectively, these results suggest that HFHC diet impairs metabolic and inflammatory pathways in an AD-relevant genotype and that soluble TNF has sex-dependent roles in modulating these pathways across anatomical compartments. Modulation of energy homeostasis and inflammation may provide new therapeutic avenues for AD.

Neural Correlates of Obesity and Inflammation in Children and Adolescents with Congenital Adrenal Hyperplasia

INTRODUCTION

Patients with classical congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency exhibit an increased prevalence of obesity from childhood including central adiposity and inflammation. There is also an emerging affected brain phenotype in CAH, with decreased cortico-limbic gray matter volumes and white matter abnormalities. We aimed to study the relationship between brain structure, obesity, and inflammation in children and adolescents with CAH compared to controls.

METHODS

27 CAH (12.6±3.4y, 16 females) and 35 controls (13.0±2.8y, 20 females) had MRI of gray matter regions of interest [prefrontal cortex (PFC), amygdala, hippocampus] and white matter microstructure [fornix, stria terminalis (ST)]. Anthropometric measures and lab analytes were obtained. Relaimpo analyses (relative importance for linear regression; percent variance) identified which brain structures were most different between groups. Subsequent regressions further quantified the magnitude and direction of these relationships. Correlations analyzed relationships between brain structure, obesity, and inflammation in the context of CAH status.

RESULTS

PFC (13.3% variance) and its superior frontal (SF) subregion (14%) were most different between CAH and controls for gray matter; ST (16%) for white matter. Patients with CAH had lower caudal middle frontal [β = -0.56, (-0.96, -0.15)] and superior frontal [β = -0.58 (-0.92, -0.25)] subregion volumes, increased orientation dispersion index in the fornix [β = 0.56 (0.01, 1.10)] and ST [β = 0.85 (0.34, 1.36)], and decreased fractional anisotropy in the fornix [β = -0.91 (-1.42, -0.42)] and ST [β = -0.83 (-1.34, -0.33)] (all p's <0.05) indicating axonal disorganization, reduced myelin content, and/or higher microglial density within the affected white matter tracts. For the full cohort, SF was correlated with MCP-1 (r=-0.41), visceral adipose tissue (r=-0.25), and waist-to-height ratio (r=-0.27, all p's <0.05); ST was correlated with MCP-1 (r=0.31) and TNF-α (r= 0.29, all p's <0.05); however, after adjusting for CAH status, almost all correlations were attenuated for significance.

CONCLUSIONS

Relationships among key brain structures, body composition and inflammatory markers in pediatric patients with CAH could be largely driven by having CAH, with implications for obesity and neuroinflammation in this high-risk population.

Cimifugin inhibits adipogenesis and TNF-α-induced insulin resistance in 3T3-L1 cells

To investigate the effects of cimifugin on adipogenesis and tumor necrosis factor (TNF-α)-induced insulin resistance (IR) and inflammation in 3T3-L1 adipocytes. 3T3-L1 adipocytes were treated with 3-isobutyl-1-methyl-xanthine, dexamethasone, and insulin or cimifugin and then Oil Red O staining and intracellular triglyceride content detection were performed to assess adipogenesis. Subsequently, after cimifugin treatment, TNF-α was used to induce IR and inflammation. The results showed that cimifugin reduced intracellular lipids accumulation of 3T3-L1 adipocytes. Cimifugin improved IR of 3T3-L1 adipocytes induced by TNF-α, as reflected in decreased adiponectin, GLUT-4, and IRS-1 mRNA and protein expression. Moreover, cimifugin reduced TNF-α-induced pro-inflammatory factors production and phospho-P65 expression, and MAPK pathway activation in the 3T3-L1 adipocytes. These findings suggested that cimifugin might be useful for the prevention and therapy of obesity-related IR and inflammation.

The Role of Perivascular Adipose Tissue in the Pathogenesis of Endothelial Dysfunction in Cardiovascular Diseases and Type 2 Diabetes Mellitus

Cardiovascular diseases (CVDs) and type 2 diabetes mellitus (T2DM) are two of the four major chronic non-communicable diseases (NCDs) representing the leading cause of death worldwide. Several studies demonstrate that endothelial dysfunction (ED) plays a central role in the pathogenesis of these chronic diseases. Although it is well known that systemic chronic inflammation and oxidative stress are primarily involved in the development of ED, recent studies have shown that perivascular adipose tissue (PVAT) is implicated in its pathogenesis, also contributing to the progression of atherosclerosis and to insulin resistance (IR). In this review, we describe the relationship between PVAT and ED, and we also analyse the role of PVAT in the pathogenesis of CVDs and T2DM, further assessing its potential therapeutic target with the aim of restoring normal ED and reducing global cardiovascular risk.

Increased Body Mass Index Augments Endothelial Injury and Clinical Outcomes after Hematopoietic Stem Cell Transplantation

Higher body mass index (BMI) is characterized as a chronic inflammatory state with endothelial dysfunction. Endothelial injury after allogeneic hematopoietic stem cell transplantation (allo-HSCT) puts patients at risk for such complications as transplantation-associated thrombotic microangiopathy (TA-TMA) and acute graft-versus-host-disease (aGVHD). To evaluate the impact of increased BMI on endothelial injury after allo-HSCT in pediatric and young adult patients, we conducted a retrospective cohort study evaluating 476 consecutive allo-HSCT children and young adult recipients age 0 to 20 years. Our analysis was subdivided based on distinct age categories (<2 years and 2 to 20 years). BMI was considered as a variable but was also expressed in standard deviations from the mean adjusted for age and sex (z-score), based on established criteria from the World Health Organization (age <2 years) and the Centers for Disease Control and Prevention (age 2 to 20 years) to account for differences associated with age. Primary endpoints included the incidences of TA-TMA and aGVHD. Increased BMI z-score was associated with TA-TMA after allo-HSCT in patients age <2 years (median, 18.1; IQR, 17 to 20; P = .006) and in patients age 2 to 20 years (median, 18.7; IQR, 16 to 21.9; P = .02). Higher BMI z-score correlated with TA-TMA risk in both age groups, with a BMI z-score of .9 in the younger cohort and .7 (IQR, -.4 to 1.6; P = .04) in the older cohort. Increased BMI z-score was associated with an increased risk of TA-TMA in a multivariate analysis of the entire cohort (odds ratio [OR], 1.2; 95% confidence interval [CI], 1.05 to 1.37; P = .008). Multivariate analysis also demonstrated that patients with BMI in the 85th percentile or greater had an increased risk of developing TA-TMA compared to those with a lower BMI percentile (OR, 2.66; 95% CI, 1.62 to 4.32; P < .001). Baseline and day +7 ST2 levels were elevated in subjects with TA-TMA compared to those without TA-TMA in both age groups. Baseline sC5b-9 concentration was not correlated with BMI z-score, but sC5b-9 concentration was increased markedly by 7 days post-allo-HSCT in patients age <2 years who later developed TA-TMA compared to those who never developed TA-TMA (P = .001). The median BMI z-score was higher for patients with aGVHD compared to patients without aGVHD (.7 [range, -3.9 to 3.9] versus .2 [range, -7.8 to 5.4]; P = .03). We show that high BMI is associated with augmented risk of endothelial injury after HSCT, specifically TA-TMA. These data identify a high-risk population likely to benefit from early interventions to prevent endothelial injury and prompt treatment of established endothelial injury.

Tumor necrosis factor-α knockout mitigates intestinal inflammation and tumorigenesis in obese Apc1638N mice

Strong evidence from observational studies shows that having body fatness is associated with an individual's risk of developing colorectal cancer (CRC), but the causality between obesity and CRC remains inadequately elucidated. Our previous studies have shown diet-induced obesity is associated with elevated TNF-α and enhanced activation of Wnt-signaling, yet the causal role of TNF-α on intestinal tumorigenesis has not been precisely studied. The present study aims to examine the functionality of TNF-α in the development of CRC associated with obesity. We first examined the extent to which diet-induced obesity elevates intestinal tumorigenesis by comparing Apc^1638N mice fed a low fat diet (LFD, 10 kcal% fat) with those fed a high fat diet (HFD, 60 kcal% fat), and then investigated the degree that the genetic ablation of TNF-α attenuates the effect by crossing the TNF-α^-/- mice with Apc^1638N mice and feeding them with the same HFD (TNF-α KO HFD). After 16-weeks of feeding, the HFD significantly increased intestinal tumorigenesis, whereas the deletion of TNF-α attenuated the effect (p < 0.05). Accompanying the changes in macroscopic tumorigenesis, HFD significantly elevated intestinal inflammation and pro-carcinogenic Wnt-signaling, whereas abolishment of TNF-α mitigated the magnitude of these elevations (p < 0.05). In summary, our findings demonstrate that the knockout of TNF-α attenuates obesity-associated intestinal tumorigenesis by decreasing intestinal inflammation and thereby the Wnt-signaling, indicating that TNF-α signaling is a potential target that can be utilized to reduce the risk of CRC associated with obesity.

Prospects of potential adipokines as therapeutic agents in obesity-linked atherogenic dyslipidemia and insulin resistance

BACKGROUND

In normal circumstances, AT secretes anti-inflammatory adipokines (AAKs) which regulates lipid metabolism, insulin sensitivity, vascular hemostasis, and angiogenesis. However, during obesity AT dysfunction occurs and leads to microvascular imbalance and secretes several pro-inflammatory adipokines (PAKs), thereby favoring atherogenic dyslipidemia and insulin resistance. Literature suggests decreased levels of circulating AAKs and increased levels of PAKs in obesity-linked disorders. Importantly, AAKs have been reported to play a vital role in obesity-linked metabolic disorders mainly insulin resistance, type-2 diabetes mellitus and coronary heart diseases. Interestingly, AAKs counteract the microvascular imbalance in AT and exert cardioprotection via several signaling pathways such as PI3-AKT/PKB pathway. Although literature reviews have presented a number of investigations detailing specific pathways involved in obesity-linked disorders, literature concerning AT dysfunction and AAKs remains sketchy. In view of the above, in the present contribution an effort has been made to provide an insight on the AT dysfunction and role of AAKs in modulating the obesity and obesity-linked atherogenesis and insulin resistance.

MAIN BODY

"Obesity-linked insulin resistance", "obesity-linked cardiometabolic disease", "anti-inflammatory adipokines", "pro-inflammatory adipokines", "adipose tissue dysfunction" and "obesity-linked microvascular dysfunction" are the keywords used for searching article. Google scholar, Google, Pubmed and Scopus were used as search engines for the articles.

CONCLUSIONS

This review offers an overview on the pathophysiology of obesity, management of obesity-linked disorders, and areas in need of attention such as novel therapeutic adipokines and their possible future perspectives as therapeutic agents.

Apelin-36 alleviates LPS-induced trophoblast cell injury by inhibiting GRP78/ASK1/JNK signaling

Pre-eclampsia (PE) is a type of hypertensive disorder of pregnancy that poses a serious threat to the health of both mother and fetus. Inhibition of the inflammatory environment on trophoblast cells is of great significance to improve PE. Apelin-36 is an endogenous active peptide with strong anti-inflammatory activity. Therefore, this study aims to investigate the effects of Apelin-36 on lipopolysaccharide (LPS)-induced trophoblast cells and its potential mechanism. The levels of inflammatory factors (TNF-α, IL-8, IL-6 and MCP-1) were detected by reverse transcription-quantitative PCR (RT-qPCR). The proliferation, apoptosis, migration and invasion capacities in trophoblast cells were detected by CCK-8, TUNEL staining, wound healing and Transwell assays, respectively. GRP78 was overexpressed by cell transfection. Western blot was applied for the identification of protein levels. Apelin concentration-dependently decreased the expression of inflammatory cytokines and p-p65 protein level in trophoblast cells induced by LPS. Apelin treatment reduced LPS-induced apoptosis and improved the proliferation, invasion and migration capacities of LPS-mediated trophoblast cells. Additionally, Apelin down-regulated GRP78, p-ASK1 and p-JNK protein levels. The inhibition on LPS-induced trophoblast cell apoptosis and the promotion on invasion and migration by Apelin-36 was counteracted by GRP78 overexpression. To sum up, Apelin-36 could alleviate LPS-induced cell inflammation and apoptosis and improve the invasion and migration of trophoblasts by inhibiting the GRP78/ASK1/JNK signaling.

Adipose Tissue Paracrine-, Autocrine-, and Matrix-Dependent Signaling during the Development and Progression of Obesity

Obesity is an ever-increasing phenomenon, with 42% of Americans being considered obese (BMI ≥ 30) and 9.2% being considered morbidly obese (BMI ≥ 40) as of 2016. With obesity being characterized by an abundance of adipose tissue expansion, abnormal tissue remodeling is a typical consequence. Importantly, this pathological tissue expansion is associated with many alterations in the cellular populations and phenotypes within the tissue, lending to cellular, paracrine, mechanical, and metabolic alterations that have local and systemic effects, including diabetes and cardiovascular disease. In particular, vascular dynamics shift during the progression of obesity, providing signaling cues that drive metabolic dysfunction. In this review, paracrine-, autocrine-, and matrix-dependent signaling between adipocytes and endothelial cells is discussed in the context of the development and progression of obesity and its consequential diseases, including adipose fibrosis, diabetes, and cardiovascular disease.

Molecular aspects of COVID-19 and its relationship with obesity and physical activity: a narrative review

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 has several mechanisms of action related to inflammatory responses, especially in individuals diagnosed with obesity. This hyperinflammatory clinical profile resulting from the association between obesity and coronavirus disease 2019 (COVID-19) may be attenuated by regular physical activity.

OBJECTIVE

The aim of this study was to review the evidence on the consequences of physical inactivity and physical activity on COVID-19 in patients with obesity.

DESIGN AND SETTING

Narrative review at the Bahiana School of Medicine and Public Health in Salvador, Brazil.

METHODS

We searched evidence on the association of COVID-19 with physical activity and obesity using the following keywords: "covid-19," "physical activity," and "obesity". The databases used were MEDLINE (PubMed), ScienceDirect, and Virtual Health Library. Studies published from 2019 to 2021 and available in Portuguese, English, and Spanish were included. The final search was conducted on September 26, 2021.

RESULTS

We identified 661 studies in the database, among which 71 were considered for inclusion in the narrative review of the molecular aspects of COVID-19 and its relationship with physical activity and obesity.

CONCLUSION

This literature review enabled the perception of the relationship between the molecular mechanisms of COVID-19 and obesity. Regular physical activity had various benefits for the inflammatory condition of the studied population, highlighting moderate-intensity.

The Role of N6-Methyladenosine Modification in Microvascular Dysfunction

Microvascular dysfunction (MVD) has long plagued the medical field despite improvements in its prevention, diagnosis, and intervention. Microvascular lesions from MVD increase with age and further lead to impaired microcirculation, target organ dysfunction, and a mass of microvascular complications, thus contributing to a heavy medical burden and rising disability rates. An up-to-date understanding of molecular mechanisms underlying MVD will facilitate discoveries of more effective therapeutic strategies. Recent advances in epigenetics have revealed that RNA methylation, an epigenetic modification, has a pivotal role in vascular events. The N⁶-methylation of adenosine (m⁶A) modification is the most prevalent internal RNA modification in eukaryotic cells, which regulates vascular transcripts through splicing, degradation, translation, as well as translocation, thus maintaining microvascular homeostasis. Conversely, the disruption of the m⁶A regulatory network will lead to MVD. Herein, we provide a review discussing how m⁶A methylation interacts with MVD. We also focus on alterations of the m⁶A regulatory network under pathological conditions. Finally, we highlight the value of m⁶A regulators as prognostic biomarkers and novel therapeutic targets, which might be a promising addition to clinical medicine.

The role of machine learning in developing non-magnetic resonance imaging based biomarkers for multiple sclerosis: a systematic review

BACKGROUND

Multiple sclerosis (MS) is a neurological condition whose symptoms, severity, and progression over time vary enormously among individuals. Ideally, each person living with MS should be provided with an accurate prognosis at the time of diagnosis, precision in initial and subsequent treatment decisions, and improved timeliness in detecting the need to reassess treatment regimens. To manage these three components, discovering an accurate, objective measure of overall disease severity is essential. Machine learning (ML) algorithms can contribute to finding such a clinically useful biomarker of MS through their ability to search and analyze datasets about potential biomarkers at scale. Our aim was to conduct a systematic review to determine how, and in what way, ML has been applied to the study of MS biomarkers on data from sources other than magnetic resonance imaging.

METHODS

Systematic searches through eight databases were conducted for literature published in 2014-2020 on MS and specified ML algorithms.

RESULTS

Of the 1, 052 returned papers, 66 met the inclusion criteria. All included papers addressed developing classifiers for MS identification or measuring its progression, typically, using hold-out evaluation on subsets of fewer than 200 participants with MS. These classifiers focused on biomarkers of MS, ranging from those derived from omics and phenotypical data (34.5% clinical, 33.3% biological, 23.0% physiological, and 9.2% drug response). Algorithmic choices were dependent on both the amount of data available for supervised ML (91.5%; 49.2% classification and 42.3% regression) and the requirement to be able to justify the resulting decision-making principles in healthcare settings. Therefore, algorithms based on decision trees and support vector machines were commonly used, and the maximum average performance of 89.9% AUC was found in random forests comparing with other ML algorithms.

CONCLUSIONS

ML is applicable to determining how candidate biomarkers perform in the assessment of disease severity. However, applying ML research to develop decision aids to help clinicians optimize treatment strategies and analyze treatment responses in individual patients calls for creating appropriate data resources and shared experimental protocols. They should target proceeding from segregated classification of signals or natural language to both holistic analyses across data modalities and clinically-meaningful differentiation of disease.

Dendrobium officinale Xianhu 2 polysaccharide helps forming a healthy gut microbiota and improving host immune system: An in vitro and in vivo study

Dendrobium officinale is widely consumed owing to its numerous beneficial effects. We aimed to characterize polysaccharides of Dendrobium officinale (DOP) from the stems of Dendrobium officinale Xianhu 2 and clarify whether it benefit the intestinal microbiota and the immune system. The DOP weighed 291 kDa and comprised mannose, glucose, galactose, and rhamnose at 59.31:33.31:1.00:0.51 M ratio. In in vitro/vivo studies, DOP significantly increased benign intestinal microbe proportion (Lactobacillus, etc.), but reduced harmful bacteria (Escherichia_Shigella) (P < 0.05), and significantly increased butyric acid production (P < 0.05). Concentrations of 2 g/L DOP for in vitro fermentation and 100 mg/kg body weight for the mouse model were effective. In mice, DOP significantly reduced CRP, CD3, CD4, and TNF-α levels and increased C4 levels (P < 0.05). DOP might influence the immune system indirectly through regulation of the gut microbiota. Its possible regulation mechanism was that DOP reduced CD4+ Th cells proliferation so that reduced the secretion of TNF-α.

Adipokine Levels in Men with Coronary Atherosclerosis on the Background of Abdominal Obesity

Background. Obesity is associated with dyslipidemia, and excess body fat is associated with unfavorable levels of adipokines and markers of inflammation. The goal of research. To study the level of adipokines and markers of inflammation, their associations with unstable atherosclerotic plaques in men with coronary atherosclerosis on the background of abdominal obesity. Materials and methods. The study involved 82 men aged 40–77 years with coronary atherosclerosis after endarterectomy from the coronary arteries. We divided all men into two groups: 37 men (45.1%) with unstable atherosclerotic plaques, and 45 men (54.9%) who had stable plaques. Obesity was established at a BMI of ≥30 kg/m2. The levels of adipokines and markers of inflammation in the blood were determined by multiplex analysis. Results. In patients with obesity and unstable plaques, the levels of C-peptide, TNFa and IL-6 were 1.8, 1.6, and 2.8 times higher, respectively, than in patients with obesity and stable plaques. The chance of having an unstable plaque increases with an increase in TNFa by 49% in obese patients and decreases with an increase in insulin by 3% in non-obese patients. Conclusions. In men with coronary atherosclerosis and obesity, unstable atherosclerotic plaques in the coronary arteries are directly associated with the level of TNF-α.

Obesity-related vascular dysfunction persists after weight loss and is associated with decreased vascular glucagon-like peptide (GLP-1) receptor in female rats

Obesity-related cardiovascular complications are a major health problem worldwide. Overconsumption of the Western diet is a well-known culprit for the development of obesity. While short-term weight loss through switching from a Western diet to a normal diet is known to promote metabolic improvement, its short-term effects on vascular parameters are not well-characterized. Glucagon-like peptide 1 (GLP-1), an incretin with vasculo-protective properties, is decreased in plasma from obese patients. We hypothesize that obesity causes persistent vascular dysfunction in association with downregulation of vascular GLP-1R. Female Wistar rats were randomized into three groups: lean received a chow diet for 28 weeks, obese received a Western diet for 28 weeks, and reverse obese received a Western diet for 18 weeks followed by 12 weeks of standard chow diet. The obese group exhibited increased body weight and body mass index, while the reverse obese group lost weight. Weight loss failed to reverse impaired vasodilation and high systolic blood pressure in obese rats. Strikingly, our results show that obese rats exhibit decreased serum levels of GLP-1 accompanied by decreased vascular GLP-1R expression. Weight loss recovered GLP-1 serum levels, however GLP-1R expression remained downregulated. Decreased Akt phosphorylation was observed in the obese and reverse obese group, suggesting that GLP-1/Akt signaling is persistently downregulated. Our results support that GLP-1 signaling is associated with obesity-related vascular dysfunction in females and short-term weight loss does not guarantee recovery of vascular function. This study suggests that GLP-1R may be a potential target for therapeutic intervention in obesity-related hypertension in females.

Effect of Vitamin D and Docosahexaenoic Acid Co-Supplementation on Vitamin D Status, Body Composition, and Metabolic Markers in Obese Children: A Randomized, Double Blind, Controlled Study

Obese children are at high risk of developing vitamin D deficiency. Omega-3 polyunsaturated fatty acids and their derivatives might have a beneficial effect on vitamin D status of obese children, due to their anti-inflammatory action, and increasing its absorption. This multicenter, randomized, double-blind controlled study aims to investigate the effect of vitamin D and docosahexaenoic acid (DHA) co-supplementation for six months on vitamin D status, body composition, and metabolic markers of obese children with vitamin D deficiency. A total of 108 children were enrolled and 73 children completed the study: 33 were supplemented with an oral dose of 500 mg of DHA and 1200 IU/day of vitamin D3 and 41 were supplemented with 1200 IU/day of vitamin D3 + wheat germ oil. At the end of the study, more than 50% of the subjects improved their vitamin D status. However, co-supplementation was not more effective than vitamin D plus wheat germ oil. Fat mass percentage was significantly reduced, and body mass index improved in both groups, even if all the subjects were still obese at the end of the study. Children receiving both vitamin D and DHA presented a higher increase of DHA levels that could be relevant to prevent inflammatory-associated complications of obesity, but they had no effect on vitamin D levels.

Healthy lifestyle and the risk of conventional adenomas and serrated polyps: Findings from a large colonoscopy screening population

Evidence on the link between healthy lifestyle and colorectal cancer (CRC) precursors is limited. Our study aimed to examine and compare the associations of healthy lifestyle with CRC precursors in adenoma (AD) -carcinoma and serrated pathways. A total of 24,480 participants including 6,309 ADs, 1,343 serrated polyps (SPs), and 16,828 polyp-free controls were included. A healthy lifestyle score (HLS) was constructed based on five lifestyle factors including cigarette smoking, alcohol drinking, physical activity, diet, and body weight, and categorized into least, slightly, moderately, and most healthy. Multivariable logistic regressions were used to estimate odds ratio (OR) and 95% confidence interval (CI). Inverse dose-response associations between the HLS and risk of ADs were observed (OR per 1 score increment for ADs: 0.82 [95% CI 0.79 - 0.84]; for SPs: 0.73 [95% CI 0.69 - 0.78]), and the association with SPs was more evident than with ADs (OR 0.90, 95% CI 0.85 - 0.96). Compared with participants with the least healthy lifestyle, those with the most healthy lifestyle had 47% lower risk of ADs (OR 0.53, 95% CI 0.47 - 0.59) and 70% lower risk of SPs (OR 0.30, 95% CI 0.23 - 0.39), respectively. These inverse associations were consistent across lesion stage and anatomic subsite and not modified by any stratification factors. The risk advancement periods for the most vs. the least healthy lifestyle were -9.49 years for ADs and -20.69 years for SPs. Our findings help confirm the preventive role of healthy lifestyle in colorectal carcinogenesis.

Skeletal Muscle Microvascular Dysfunction in Obesity-Related Insulin Resistance: Pathophysiological Mechanisms and Therapeutic Perspectives

Obesity is a worrisomely escalating public health problem globally and one of the leading causes of morbidity and mortality from noncommunicable disease. The epidemiological link between obesity and a broad spectrum of cardiometabolic disorders has been well documented; however, the underlying pathophysiological mechanisms are only partially understood, and effective treatment options remain scarce. Given its critical role in glucose metabolism, skeletal muscle has increasingly become a focus of attention in understanding the mechanisms of impaired insulin function in obesity and the associated metabolic sequelae. We examined the current evidence on the relationship between microvascular dysfunction and insulin resistance in obesity. A growing body of evidence suggest an intimate and reciprocal relationship between skeletal muscle microvascular and glucometabolic physiology. The obesity phenotype is characterized by structural and functional changes in the skeletal muscle microcirculation which contribute to insulin dysfunction and disturbed glucose homeostasis. Several interconnected etiologic molecular mechanisms have been suggested, including endothelial dysfunction by several factors, extracellular matrix remodelling, and induction of oxidative stress and the immunoinflammatory phenotype. We further correlated currently available pharmacological agents that have deductive therapeutic relevance to the explored pathophysiological mechanisms, highlighting a potential clinical perspective in obesity treatment.

Adipose tissue macrophages and atherogenesis – a synergy with cholesterolaemia

Excessive LDL cholesterol concentration together with subclinical inflammation, in which macrophages play a central role, are linked pathologies. The process starts with the accumulation of macrophages in white adipose tissue and the switch of their polarization toward a pro-inflammatory phenotype. The proportion of pro-inflammatory macrophages in adipose tissue is related to the main risk predictors of cardiovascular disease. The cholesterol content of phospholipids of cell membranes seems to possess a crucial role in the regulation of membrane signal transduction and macrophage polarization. Also, different fatty acids of membrane phospholipids influence phenotypes of adipose tissue macrophages with saturated fatty acids stimulating pro-inflammatory whereas ω3 fatty acids anti-inflammatory changes. The inflammatory status of white adipose tissue, therefore, reflects not only adipose tissue volume but also adipose tissue macrophages feature. The beneficial dietary change leading to an atherogenic lipoprotein decrease may therefore synergically reduce adipose tissue driven inflammation.

AT2R stimulation with C21 prevents arterial stiffening and endothelial dysfunction in the abdominal aorta from mice fed a high-fat diet

The aim of the present study was to evaluate the effect of Compound 21 (C21), a selective AT2R agonist, on the prevention of endothelial dysfunction, extracellular matrix (ECM) remodeling and arterial stiffness associated with diet-induced obesity (DIO). Five-week-old male C57BL/6J mice were fed a standard (Chow) or high-fat diet (HF) for 6 weeks. Half of the animals of each group were simultaneously treated with C21 (1 mg/kg/day, in the drinking water), generating four groups: Chow C, Chow C21, HF C, and HF C21. Vascular function and mechanical properties were determined in the abdominal aorta. To evaluate ECM remodeling, collagen deposition and TGF-β1 concentrations were determined in the abdominal aorta and the activity of metalloproteinases (MMP) 2 and 9 was analyzed in the plasma. Abdominal aortas from HF C mice showed endothelial dysfunction as well as enhanced contractile but reduced relaxant responses to Ang II. This effect was abrogated with C21 treatment by preserving NO availability. A left-shift in the tension-stretch relationship, paralleled by an augmented β-index (marker of intrinsic arterial stiffness), and enhanced collagen deposition and MMP-2/-9 activities were also detected in HF mice. However, when treated with C21, HF mice exhibited lower TGF-β1 levels in abdominal aortas together with reduced MMP activities and collagen deposition compared with HF C mice. In conclusion, these data demonstrate that AT2R stimulation by C21 in obesity preserves NO availability and prevents unhealthy vascular remodeling, thus protecting the abdominal aorta in HF mice against the development of endothelial dysfunction, ECM remodeling and arterial stiffness.

Vaccinium virgatum Aiton Leaves Extract Suppressed Lipid Accumulation and Uric Acid Production in 3T3-L1 Adipocytes

Blueberry (Vaccinium virgatum Aiton; Kinisato 35 Gou) leaves have recently attracted increasing attention as a useful material for the prevention of lifestyle diseases. Here, we examined the effects of the hot water extract of blueberry leaves (BLEx) on lipogenesis and uric acid production in 3T3-L1 adipocytes. The results showed that BLEx suppressed lipid accumulation and the mRNA expression of differentiation markers in 3T3-L1 adipocytes. A fractionation study showed that the highly polymerized proanthocyanidin-rich fraction was responsible for this effect. Upon maturation to adipocytes, 3T3-L1 cells produced uric acid and tumor necrosis factor-α, and hypoxia stimulated the production of uric acid and xanthine oxidoreductase activity. BLEx suppressed the production of uric acid under these conditions. Although BLEx inhibited the enzymatic activity of xanthine oxidase, this activity was observed in several fractions containing catechin, epicatechin, chlorogenic acid, rutin, and low molecular weight proanthocyanidins. Taken together, these results indicate that BLEx contains various compounds with the ability to suppress lipid accumulation and uric acid production in adipocytes.

A body shape index is associated with endothelial dysfunction in both men and women

A body shape index (ABSI) was proposed for estimation of abdominal adiposity. ABSI has been reported to have associations with cardiovascular risk factors and cardiovascular events. However, there is no information on the association between ABSI and endothelial function. We examined cross-sectional associations of ABSI with endothelial function in 8823 subjects (6773 men and 2050 women). Subjects with a lower quartile of flow-mediated vasodilation (FMD) were defined as subjects having endothelial dysfunction. Pearson’s correlation coefficient analysis revealed that ABSI was negatively correlated with FMD (men, r = − 0.23, P = 0.003; women, r = − 0.32, P < 0.001). The areas under the curves of ABSI and body mass index to predict endothelial dysfunction were 0.64 (95% confidence interval [CI] 0.62–0.65) and 0.58 (95% CI 0.57–0.60) in men, and 0.68 (95% CI 0.66–0.71) and 0.59 (95% CI 0.56–0.61) in women, respectively. The cutoff values of ABSI for predicting subjects with endothelial dysfunction were 0.0796 (sensitivity, 55.2%; specificity, 65.5%) in men and 0.0823 (sensitivity, 56.2%; specificity, 73.4%) in women. Multivariate analysis revealed that an ABSI value higher than the cutoff value remained an independent predictor of endothelial dysfunction in both sexes. The results of our study suggest that ABSI calculation should be performed for evaluation of risk of cardiovascular events in both men and women.

Clinical trial registration information URL for Clinical Trial: https://www.umin.ac.jp/ctr/index.htm; Registration Number for Clinical Trial: UMIN000012952 (01/05/2010).

Obesity and its effects on the esophageal mucosal barrier

Obesity is associated with gastroesophageal reflux disease (GERD) and its complications including reflux esophagitis, Barrett's esophagus, and esophageal adenocarcinoma. Traditionally, these associations have been attributed to the mechanical effect of abdominal fat in increasing intra-abdominal pressure, thereby promoting gastroesophageal reflux and causing disruption of antireflux mechanisms at the esophagogastric junction. However, recent studies suggest that visceral adipose tissue (VAT) produces numerous cytokines that can cause esophageal inflammation and impair esophageal mucosal barrier integrity through reflux-independent mechanisms that render the esophageal mucosa especially susceptible to GERD-induced injury. In this report, we review mechanisms of esophageal mucosal defense, the genesis and remodeling of visceral adipose tissue during obesity, and the potential role of substances produced by VAT, especially the VAT that encircles the esophagogastric junction, in the impairment of esophageal mucosal barrier integrity that leads to the development of GERD complications.

Activation of the Constitutive Androstane Receptor Inhibits Leukocyte Adhesiveness to Dysfunctional Endothelium

Leukocyte cell recruitment into the vascular subendothelium constitutes an early event in the atherogenic process. As the effect of the constitutive androstane receptor (CAR) on leukocyte recruitment and endothelial dysfunction is poorly understood, this study investigated whether the role of CAR activation can affect this response and the underlying mechanisms involved. Under physiological flow conditions, TNFα-induced endothelial adhesion of human leukocyte cells was concentration-dependently inhibited by preincubation of human umbilical arterial endothelial cells with the selective human CAR ligand CITCO. CAR agonism also prevented TNFα induced VCAM-1 expression, as well as MCP-1/CCL-2 and RANTES/CCL-5 release in endothelial cells. Suppression of CAR expression with a small interfering RNA abrogated the inhibitory effects of CITCO on these responses. Furthermore, CITCO increased interaction of CAR with Retinoid X Receptor (RXR) and reduced TNFα-induced p38-MAPK/NF-κB activation. In vivo, using intravital microscopy in the mouse cremasteric microcirculation treatment with the selective mouse CAR ligand TCPOBOP inhibited TNFα-induced leukocyte rolling flux, adhesion, and emigration and decreased VCAM-1 in endothelium. These results reveal that CAR agonists can inhibit the initial inflammatory response that precedes the atherogenic process by targeting different steps in the leukocyte recruitment cascade. Therefore, CAR agonists may constitute a new therapeutic tool in controlling cardiovascular disease-associated inflammatory processes.

Adipose Tissue-Endothelial Cell Interactions in Obesity-Induced Endothelial Dysfunction

Obesity has a strong impact on the pathogenesis of cardiovascular disease, which raises enthusiasm to understand how excess adiposity causes vascular injury. Adipose tissue is an essential regulator of cardiovascular system through its endocrine and paracrine bioactive products. Obesity induces endothelial dysfunction, which often precedes and leads to the development of cardiovascular diseases. Connecting adipose tissue-endothelial cell interplay to endothelial dysfunction may help us to better understand obesity-induced cardiovascular disease. This Mini Review discussed (1) the general interactions and obesity-induced endothelial dysfunction, (2) potential targets, and (3) the outstanding questions for future research.

The evolving obesity challenge: targeting the vagus nerve and the inflammatory reflex in the response

Obesity and the metabolic syndrome (MetS), which have reached pandemic proportions significantly increase the risk for type 2 diabetes, cardiovascular disease, and other serious conditions. Recent data with COVID-19 patients indicate that obesity also is a significant risk factor for this novel viral disease and poor outcome of associated critical illness. These findings considerably change the view of obesity as a driver of serious, but slowly-progressing chronic diseases, and emphasize the urgency to explore new therapeutic approaches. Inflammation is a recognized driver of metabolic derangements in obesity and MetS, and a core feature of COVID-19 pathobiology. Recent advances in our understanding of inflammatory regulation have highlighted the role of the nervous system and the vagus nerve-based inflammatory reflex. Current bioelectronic and pharmacological therapeutic explorations centered on the inflammatory reflex offer new approaches for conditions characterized by immune and metabolic dysregulation and for ameliorating the escalating burden of obesity, MetS, and COVID-19.

Therapeutic Stalemate in Heart Failure With Preserved Ejection Fraction

The findings of randomized trials of neurohormonal modulation have been neutral in heart failure with preserved ejection fraction and consistently positive in heart failure with reduced ejection. Left ventricular remodeling promotes the development and progression of heart failure with preserved and reduced ejection fraction. However, different stimuli mediate left ventricular remodeling that is commonly concentric in heart failure with preserved ejection fraction and eccentric in heart failure with reduced ejection. The stimuli that promote concentric left ventricular remodeling may account for the neutral findings of neuhormonal modulation in heart failure with preserved ejection fraction. Low‐grade systemic inflammation‐induced microvascular endothelial dysfunction is currently the leading hypothesis behind the development and progression of heart failure with preserved ejection fraction. The hypothesis provided the rationale for several randomized controlled trials that have led to neutral findings. The trials and their limitations are reviewed.

HA and HS Changes in Endothelial Inflammatory Activation

Cardiovascular diseases are a group of disorders caused by the presence of a combination of risk factors, such as tobacco use, unhealthy diet and obesity, physical inactivity, etc., which cause the modification of the composition of the vessel’s matrix and lead to the alteration of blood flow, matched with an inflammation condition. Nevertheless, it is not clear if the inflammation is a permissive condition or a consequent one. In order to investigate the effect of inflammation on the onset of vascular disease, we treated endothelial cells with the cytokine TNF-α that is increased in obese patients and is reported to induce cardiometabolic diseases. The inflammation induced a large change in the extracellular matrix, increasing the pericellular hyaluronan and altering the heparan sulfate Syndecans sets, which seems to be related to layer permeability but does not influence cell proliferation or migration nor induce blood cell recruitment or activation.

Cell-specific epigenetic changes in atherosclerosis

Atherosclerosis is a disease of large and medium arteries that can lead to life-threatening cerebrovascular and cardiovascular consequences such as heart failure and stroke and is a major contributor to cardiovascular-related mortality worldwide. Atherosclerosis development is a complex process that involves specific structural, functional and transcriptional changes in different vascular cell populations at different stages of the disease. The application of single-cell RNA sequencing (scRNA-seq) analysis has discovered not only disease-related cell-specific transcriptomic profiles but also novel subpopulations of cells once thought as homogenous cell populations. Vascular cells undergo specific transcriptional changes during the entire course of the disease. Epigenetics is the instruction-set-architecture in living cells that defines and maintains the cellular identity by regulating the cellular transcriptome. Although different cells contain the same genetic material, they have different epigenomic signatures. The epigenome is plastic, dynamic and highly responsive to environmental stimuli. Modifications to the epigenome are driven by an array of epigenetic enzymes generally referred to as writers, erasers and readers that define cellular fate and destiny. The reversibility of these modifications raises hope for finding novel therapeutic targets for modifiable pathological conditions including atherosclerosis where the involvement of epigenetics is increasingly appreciated. This article provides a critical review of the up-to-date research in the field of epigenetics mainly focusing on in vivo settings in the context of the cellular role of individual vascular cell types in the development of atherosclerosis.

Differential Deleterious Impact of Highly Saturated Versus Monounsaturated Fat Intake on Vascular Function, Structure, and Mechanics in Mice

Vegetable oils such as palm oil (enriched in saturated fatty acids, SFA) and high-oleic-acid sunflower oil (HOSO, containing mainly monounsaturated fatty acids, MUFA) have emerged as the most common replacements for trans-fats in the food industry. The aim of this study is to analyze the impact of SFA and MUFA-enriched high-fat (HF) diets on endothelial function, vascular remodeling, and arterial stiffness compared to commercial HF diets. Five-week-old male C57BL6J mice were fed a standard (SD), a HF diet enriched with SFA (saturated oil-enriched Food, SOLF), a HF diet enriched with MUFA (unsaturated oil-enriched Food, UOLF), or a commercial HF diet for 8 weeks. Vascular function was analyzed in the thoracic aorta. Structural and mechanical parameters were assessed in mesenteric arteries by pressure myography. SOLF, UOLF, and HF diet reduced contractile responses to phenylephrine and induced endothelial dysfunction in the thoracic aorta. A significant increase in the β-index, and thus in arterial stiffness, was also detected in mesenteric arteries from the three HF groups, due to enhanced deposition of collagen in the vascular wall. SOLF also induced hypotrophic inward remodeling. In conclusion, these data demonstrate a deleterious effect of HF feeding on obesity-related vascular alterations that is exacerbated by SFA.

The effect of Plantago major supplementation on leptin and VEGF-A serum levels, endothelial dysfunction and angiogenesis in obese women - a randomised trial

Obesity is associated with increased serum leptin level, endothelial dysfunction and angiogenesis. In vitro studies have shown that vascular endothelial growth factor (VEGF) synthesis is increased by leptin. Animal studies revealed the effectiveness of Plantago supplementation treatment of obesity. The study aim was to evaluate the effect of Plantago major supplementation on serum leptin and VEGF blood concentration, endothelial dysfunction and angiogenesis in obese women. Seventy-two obese women received oral Plantago major supplement (Plantago group, n = 35) or placebo (placebo group, n = 37) for 12 weeks. At baseline and after completion, anthropometric and body composition measurements were performed, and blood samples were collected. Serum concentrations of leptin, VEGF-A, adiponectin, tumour necrosis factor α and soluble intercellular adhesion molecule have been determined. At completion, the leptin level was higher in the Plantago group (39 781.55 ± 20 360.73 pg ml-1) compared to both the baseline (36 138.71 ± 25 401.51 pg ml-1) and placebo group (30 502.81 ± 19 003.18 pg ml-1). Also, leptin concentration in the Plantago group at completion correlated positively with an increase in VEGF-A level (R = 0.45), and baseline VEGF-A level correlated negatively with the increase in leptin concentration (R = -0.47). Plantago major supplementation increases leptin serum level, enhances leptin influence on VEGF-A serum level increase and by this mechanism may intensify endothelial dysfunction and angiogenesis in obese women.

Determination of serum tumor necrosis factor-alpha (TNF-α) levels in metabolic syndrome patients from Saudi population

Objectives:

To detect the relationship between serum tumor necrosis factor-alpha (TNF-α) and metabolic syndrome (MetS) components in patients of the Saudi population.

Methods:

This cross-sectional study was carried out at Jouf University Saudi Arabia from September 2019 to August 2020 and comprised of 183 individuals (91 cases and 92 controls). The blood samples were drawn from the patients visiting two tertiary care settings of Al Jouf province. Biochemical analysis was conducted on various instruments, and serum TNF-α was measured by the ELISA method.

Results:

The levels of serum glucose fasting, lipid profile, HbA1c and body mass index (BMI) were raised significantly in cases of MetS than controls (p = 0.001). Serum TNF-α was significantly higher in patients (58.04 ± 15.44) than controls (48.81 ± 10.30). It was correlated with the BMI, blood HbA1c, serum fasting glucose (SFG) and serum high density lipoprotein (HDL). The weak positive correlation was found with BMI (r = 0.18; p = 0.01), serum glucose (r = 0.21; p = 0.007) and HbA1c (r = 0.14; p = 0.04), but found negative association with serum HDL (r = -0.18; p = 0.01).

Conclusion:

The serum TNF-α was raised in metabolic syndrome patients than the healthy controls. It was positively associated with high BMI, serum fasting glucose, and HbA1c and found linked and negatively linked to low HDL levels in MetS patients in the Saudi population.

USP2-Related Cellular Signaling and Consequent Pathophysiological Outcomes

Ubiquitin specific protease (USP) 2 is a multifunctional deubiquitinating enzyme. USP2 modulates cell cycle progression, and therefore carcinogenesis, via the deubiquitination of cyclins and Aurora-A. Other tumorigenic molecules, including epidermal growth factor and fatty acid synthase, are also targets for USP2. USP2 additionally prevents p53 signaling. On the other hand, USP2 functions as a key component of the CLOCK/BMAL1 complex and participates in rhythmic gene expression in the suprachiasmatic nucleus and liver. USP2 variants influence energy metabolism by controlling hepatic gluconeogenesis, hepatic cholesterol uptake, adipose tissue inflammation, and subsequent systemic insulin sensitivity. USP2 also has the potential to promote surface expression of ion channels in renal and intestinal epithelial cells. In addition to modifying the production of cytokines in immune cells, USP2 also modulates the signaling molecules that are involved in cytokine signaling in the target cells. Usp2 knockout mice exhibit changes in locomotion and male fertility, which suggest roles for USP2 in the central nervous system and male genital tract, respectively. In this review, we summarize the cellular events with USP2 contributions and list the signaling molecules that are upstream or downstream of USP2. Additionally, we describe phenotypic differences found in the in vitro and in vivo experimental models.

Fenugreek attenuates obesity-induced inflammation and improves insulin resistance through downregulation of iRhom2/TACE

AIMS

We previously reported that fenugreek-derived 4-hydroxyisoleucine ameliorates insulin resistance via regulation of TNF-α converting enzyme (TACE) expression. In the present study, we further investigate the effects and mechanisms of fenugreek on obesity-induced inflammation and insulin signaling in the high-fat diet (HFD)-challenged obese mice.

MAIN METHODS

After 12 weeks of HFD intervention, mice were treated with the low or high dosages of fenugreek. Serum levels of glucose, insulin, lipid profile, inflammation cytokines, and adipokines were detected. Macrophage infiltration and adipose tissue morphology were observed. Western blot was conducted to investigate the expressions of inactive rhomboid 2 (iRhom2) and TACE as well as other signaling pathways in subcutaneous adipose tissue.

KEY FINDINGS

We showed that fenugreek significantly suppressed body weight gain and fat accumulation in HFD-challenged obese mice. Meanwhile, fasting glucose, insulin, and HOMA-IR in fenugreek-treated mice were remarkably decreased, which were properly explained by fenugreek-induced activation of the insulin receptor signaling pathway. Moreover, the anti-inflammatory properties of fenugreek were shown by the decrease of systemic and local expressions of pro-inflammatory cytokines as well as reduced macrophage infiltration into adipose tissue. Additionally, fenugreek markedly deactivated NF-κB and JNK pathways. Finally, we demonstrated that fenugreek strikingly repressed the transcriptions and expressions of iRhom2 and TACE.

SIGNIFICANCE

Fenugreek shows an encouraging and promising property in ameliorating insulin resistance and suppressing inflammation in obesity, which might be realized by fenugreek-mediated inhibition of iRhom2/TACE axis-facilitated TNF-α release from adipocytes.

MicroRNAs and obesity-induced endothelial dysfunction: key paradigms in molecular therapy

The endothelium plays a pivotal role in maintaining vascular health. Obesity is a global epidemic that has seen dramatic increases in both adult and pediatric populations. Obesity perturbs the integrity of normal endothelium, leading to endothelial dysfunction which predisposes the patient to cardiovascular diseases. MicroRNAs (miRNAs) are short, single-stranded, non-coding RNA molecules that play important roles in a variety of cellular processes such as differentiation, proliferation, apoptosis, and stress response; their alteration contributes to the development of many pathologies including obesity. Mediators of obesity-induced endothelial dysfunction include altered endothelial nitric oxide synthase (eNOS), Sirtuin 1 (SIRT1), oxidative stress, autophagy machinery and endoplasmic reticulum (ER) stress. All of these factors have been shown to be either directly or indirectly caused by gene regulatory mechanisms of miRNAs. In this review, we aim to provide a comprehensive description of the therapeutic potential of miRNAs to treat obesity-induced endothelial dysfunction. This may lead to the identification of new targets for interventions that may prevent or delay the development of obesity-related cardiovascular disease.

DNA Methylation in Adipose Tissue and Metabolic Syndrome

Epigenetics is the study of heritable phenotype changes that do not involve alterations in the DNA sequence with the processes including DNA methylation, histone modifications and RNA-associated silencing [...].

Maternal Obesity and the Uterine Immune Cell Landscape: The Shaping Role of Inflammation

Inflammation is often equated to the physiological response to injury or infection. Inflammatory responses defined by cytokine storms control cellular mechanisms that can either resolve quickly (i.e., acute inflammation) or remain prolonged and unabated (i.e., chronic inflammation). Perhaps less well-appreciated is the importance of inflammatory processes central to healthy pregnancy, including implantation, early stages of placentation, and parturition. Pregnancy juxtaposed with disease can lead to the perpetuation of aberrant inflammation that likely contributes to or potentiates maternal morbidity and poor fetal outcome. Maternal obesity, a prevalent condition within women of reproductive age, associates with increased risk of developing multiple pregnancy disorders. Importantly, chronic low-grade inflammation is thought to underlie the development of obesity-related obstetric and perinatal complications. While diverse subsets of uterine immune cells play central roles in initiating and maintaining healthy pregnancy, uterine leukocyte dysfunction as a result of maternal obesity may underpin the development of pregnancy disorders. In this review we discuss the current knowledge related to the impact of maternal obesity and obesity-associated inflammation on uterine immune cell function, utero-placental establishment, and pregnancy health.

Pathobiology of pulmonary artery hypertension: role of long non-coding RNAs

Pulmonary arterial hypertension (PAH) is a disease with complex pathobiology, significant morbidity and mortality, and remains without a cure. It is characterized by vascular remodelling associated with uncontrolled proliferation of pulmonary artery smooth muscle cells, endothelial cell proliferation and dysfunction, and endothelial-to-mesenchymal transition, leading to narrowing of the vascular lumen, increased vascular resistance and pulmonary arterial pressure, which inevitably results in right heart failure and death. There are multiple molecules and signalling pathways that are involved in the vascular remodelling, including non-coding RNAs, i.e. microRNAs and long non-coding RNAs (lncRNAs). It is only in recent years that the role of lncRNAs in the pathobiology of pulmonary vascular remodelling and right ventricular dysfunction is being vigorously investigated. In this review, we have summarized the current state of knowledge about the role of lncRNAs as key drivers and gatekeepers in regulating major cellular and molecular trafficking involved in the pathogenesis of PAH. In addition, we have discussed the limitations and challenges in translating lncRNA research in vivo and in therapeutic applications of lncRNAs in PAH.

Altered cyclooxygenase-1 and enhanced thromboxane receptor activities underlie attenuated endothelial dilatory capacity of omental arteries in obesity

AIMS

Obesity is a risk factor for endothelial dysfunction, the severity of which is likely to vary depending on extent and impact of adiposity on the vasculature. This study investigates the roles of cyclooxygenase isoforms and thromboxane receptor activities in the differential endothelial dilatory capacities of arteries derived from omental and subcutaneous adipose tissues in obesity.

MAIN METHODS

Small arteries were isolated from omental and subcutaneous adipose tissues obtained from consented morbidly obese patients (n = 65, BMI 45 ± 6 kg m^-2 [Mean ± SD]) undergoing bariatric surgery. Relaxation to acetylcholine was studied by wire myography in the absence or presence of indomethacin (10 μM, cyclooxygenase inhibitor), FR122047 (1 μM, cyclooxygenase-1 inhibitor), Celecoxib (4 μM, cyclooxygenase-2 inhibitor), Nω-Nitro-L-arginine methyl ester (L-NAME, 100 μM, nitric oxide synthase inhibitor) or combination of apamin (0.5 μM) and charybdotoxin (0.1 μM) that together inhibit endothelium-derived hyperpolarizing factor (EDHF). Contractions to U46619 (thromboxane A₂ mimetic) were also studied.

KEY FINDINGS

Acetylcholine relaxation was significantly attenuated in omental compared with subcutaneous arteries from same patients (p < 0.01). Indomethacin (p < 0.01) and FR122047 (p < 0.001) but not Celecoxib significantly improved the omental arteriolar relaxation. Cyclooxygenase-1 mRNA and U46619 contractions were both increased in omental compared with subcutaneous arteries (p < 0.05). L-NAME comparably inhibited acetylcholine relaxation in both arteries, while apamin+charybdotoxin were less effective in omental compared with subcutaneous arteries.

SIGNIFICANCE

The results show that the depot-specific reduction in endothelial dilatory capacity of omental compared with subcutaneous arteries in obesity is in large part due to altered cyclooxygenase-1 and enhanced thromboxane receptor activities, which cause EDHF deficiency.

The role of pro-inflammatory cytokines in lipid metabolism of metabolic diseases

Adipose tissue has been considered as a crucial source of certain pro-inflammatory cytokines; conversely, these pro-inflammatory cytokines are involved in regulating the proliferation and apoptosis of adipocytes, promoting lipolysis, inhibiting lipid synthesis and decreasing blood lipids, etc. In recent decades, extensive studies have indicated that pro-inflammatory cytokines play important roles in the development of lipid metabolism of metabolic diseases, including obesity, atherosclerosis, steatohepatitis and hyperlipoproteinemia. However, the involved pro-inflammatory cytokines types and the underlying mechanisms remain largely unknown. The "re-discovery" of cancer as a metabolic disorder largely occurred in the last five years. Although pro-inflammatory cytokines have been intensively investigated in cancer research, there are very few studies about the roles of pro-inflammatory cytokines in the lipid metabolism of cancer. In the current review, we provide an overview of the progress that has been made in the roles of different pro-inflammatory cytokines in lipid metabolism of metabolic diseases including cancer.

Anti-TNF-α Agent Tamarind Kunitz Trypsin Inhibitor Improves Lipid Profile of Wistar Rats Presenting Dyslipidemia and Diet-induced Obesity Regardless of PPAR-γ Induction

: The increasing prevalence of obesity and, consequently, chronic inflammation and its complications has increased the search for new treatment methods. The effect of the purified tamarind seed trypsin inhibitor (TTIp) on metabolic alterations in Wistar rats with obesity and dyslipidemia was evaluated. Three groups of animals with obesity and dyslipidemia were formed, consuming a high glycemic index and glycemic load (HGLI) diet, for 10 days: Obese/HGLI diet; Obese/standard diet; Obese/HGLI diet + TTIp (730 μg/kg); and one eutrophic group of animals was fed a standard diet. Rats were evaluated daily for food intake and weight gain. On the 11th day, animals were anesthetized and sacrificed for blood and visceral adipose tissue collection. TTIp treated animals presented significantly lower food intake than the untreated group (p = 0.0065), TG (76.20 ± 18.73 mg/dL) and VLDL-C (15.24 ± 3.75 mg/dL). Plasma concentrations and TNF-α mRNA expression in visceral adipose tissue also decreased in obese animals treated with TTIp (p < 0.05 and p = 0.025, respectively) with a negative immunostaining. We conclude that TTIp presented anti-TNF-α activity and an improved lipid profile of Wistar rats with dyslipidemia and obesity induced by a high glycemic index and load diet regardless of PPAR-γ induction.

The protective effect of hydroxytyrosol acetate against inflammation of vascular endothelial cells partly through the SIRT6-mediated PKM2 signaling pathway

HT-AC had anti-inflammatory effect in hypercholesterolemic mice and TNF-stimulated HUVECs. HT-AC inhibited the inflammatory response partly through the TNFRSF1A/SIRT6/PKM2-mediated signaling pathway.

Should Cushing's Syndrome be Considered as a Disease with High Cardiovascular Risk in Relevant Guidelines?

A considerable amount of data supports a 1.8-7.4-fold increased mortality associated with Cushing's syndrome (CS). This is attributed to a high occurrence of several cardiovascular disease (CVD) risk factors in CS [e.g. adiposity, arterial hypertension (AHT), dyslipidaemia and type 2 diabetes mellitus (T2DM)]. Therefore, practically all patients with CS have the metabolic syndrome (MetS), which represents a high CVD risk. Characteristically, despite a relatively young average age, numerous patients with CS display a 'high' or 'very high' CVD risk (i.e. risk of a major CVD event >20% in the following 10 years). Although T2DM is listed as a condition with a high CVD risk, CS is not, despite the fact that a considerable proportion of the CS population will develop T2DM or impaired glucose tolerance. CS is also regarded as a risk factor for aortic dissection in current guidelines. This review considers the evidence supporting listing CS among high CVD risk conditions.