Glucocorticoid inhibition of leptin- and lipopolysaccharide-induced interleukin-6 production in obesity

Uncovering the effect of Moringa oleifera Lam. leaf addition to Fuzhuan Brick Tea on sensory properties, volatile profiles and anti-obesity activity

As a nutritious plant with valuable potential, the Moringa oleifera Lam. leaf addition to Fuzhuan Brick Tea (FBT) for co-fermentation is an industrial innovation and a new route to make full use of Moringa oleifera Lam. leaves. However, the sensory properties, volatile profiles and anti-obesity activity of Fuzhuan Brick (Moringa oleifera Lam.) tea (MFBT) are still unknown. The results demonstrated that MFBT has richer and more complex smell and taste, better color and higher overall acceptance scores. In total, 57 volatile flavor compounds, consisting of 3 acids, 16 hydrocarbons, 5 esters, 8 ketones, 13 aldehydes, 6 alcohols and others, were identified using HS-SPME-GC-MS. The characteristic odor components in MFBT were 3-buten-2-one, 4-(2,6,6-trimethyl-1-cyclohexen-1-yl)- and 1-cyclohexene-1-carboxaldehyde, 2,6,6-trimethyl-, which gave it a floral, woody, sweet, herbal and fruity aroma. 2-Octenal, (E) contributed significantly to the aroma of FBT, which could impart fresh, fatty and green aromas. In addition, MFBT could better regulate lipid accumulation, glucose tolerance, insulin tolerance and inflammation response more effectively than FBT. The mechanism is that MFBT could better regulate the dysbiosis of gut microbiota induced by HFFD, mainly increasing the abundance of beneficial bacteria such as SCFA-producing bacteria (Bacteroidetes, Lactobacillaceae, Bacteroidales_S24-7_group and Clostridiaceae_1) and decreasing the abundance of harmful bacteria such as pro-inflammatory/obesity and metabolic syndrome-related bacteria (Proteobacteria, Deferribacteres, Desulfovibrio, Catenibacterium and Helicobacter), which in turn increased feces short-chain fatty acids and lowered circulating lipopolysaccharides. These results suggested that co-fermentation with Moringa oleifera Lam. leaf could significantly improve the quality and enhance the anti-obesity effect of FBT.

Pathways to Severe COVID-19 for People with Obesity

Increased morbidity and mortality from coronavirus disease 2019 (COVID-19) in people with obesity have illuminated the intersection of obesity with impaired responses to infections. Although data on mechanisms by which COVID-19 impacts health are being rapidly generated, there is a critical need to better understand the pulmonary, vascular, metabolic, and immunologic aspects that drive the increased risk for complications from COVID-19 in people with obesity. This review provides a broad overview of the intersection between COVID-19 and the physiology of obesity in order to highlight potential mechanisms by which COVID-19 disease severity is increased by obesity and identify areas for future investigation toward developing tailored therapy for people with obesity who develop COVID-19.

Aurantio-obtusin improves obesity and insulin resistance induced by high-fat diet in obese mice

Aurantio-obtusin (AUR) is the main bioactive compound among the anthraquinones, from Cassia seed extract. This study was conducted to identify whether AUR could improve obesity and insulin resistance, induced by a high-fat diet in obese mice. Mice were fed a high-fat diet for 6 weeks and were then assigned to the high-fat diet (HFD) control group, the AUR 5 mg/kg group, or the AUR 10 mg/kg group. AUR improves glucose by activating the expression of PI3K, Akt and GLUT4, GLUT2. AUR altered the expression levels of several lipid metabolism-related and adipokine genes. AUR decreased the mRNA expression of PPAR-γ, FAS and increased the mRNA expression of PPAR-α in liver. AUR lowered SREBP-1c, FAS, SCD-1, inflammatory cytokines, and increased the expression of PPAR-γ, PPAR-α, CPT-1, and adiponectin in white adipose tissue (WAT). AUR docking with the insulin receptor showed that the residues of the insulin receptor, ectodomain, were the same as those around the emodin. The effect of AUR may be elicited by regulating the activity of the insulin signaling pathway, expression of lipid metabolism-related genes, and expression of inflammatory cytokine markers to improve adiposity, insulin resistance, and dyslipidemia.

Plasmacytoid dendritic cell and myeloid dendritic cell function in ageing: A comparison between elderly and young adult women

Ageing is associated with a changing immune system, leading to inflammageing (increased levels of inflammation markers in serum) and immunosenescence (reduced immune cells and reduced responses towards pathogens). This results in reduced vaccination responses and increased infections in elderly. Much is known about the adaptive immune system upon ageing, but less is known about the innate immune system. Therefore, the aim of this study was to compare innate immune function of Toll like receptor (TLR)-mediated responses between elderly and young adult women.

To this end, elderly and young adult women were compared to study the effect of ageing on the relative prevalence and reactivity to TLR-mediated responses of myeloid- and plasmacytoid dendritic cells (mDC, pDC). In addition, TLR expression and inflammatory markers in serum were investigated. Elderly women had reduced numbers of circulating pDCs. In addition, pDCs and mDCs of elderly women responded differently towards TLR stimulation, especially TLR7/8 mediated stimulation was reduced, compared to young adults. In serum, markers involved in inflammation were generally increased in elderly. In conclusion, this study confirms and extends the knowledge about immunosenescence and inflammageing on innate immunity in elderly women.

Association Between Cortisol, Insulin Resistance and Zinc in Obesity: a Mini-Review

Adipose tissue is considered an endocrine organ and its excess compromises the immune response and the metabolism of hormones and nutrients. Furthermore, visceral fat accumulation contributes to increased cortisol synthesis, which in turn induces metallothionein and Zip14 expression, which are proteins that contribute to reducing plasma zinc levels. Zinc plays a critical role in the secretion and signaling of insulin. Changes in the biochemical parameters of zinc, as observed in individuals who are obese, contribute to the manifestation of related disorders such as insulin resistance. Thus, the purpose of this review is to provide an update on the current information on the relationship between cortisol, zinc, and insulin resistance in obesity. The data in the literature provide evidence that cortisol affects zinc metabolism, and indicate possible repercussions on insulin signaling that might contribute to the development of resistance to the actions of insulin in obesity.

Lipopolysaccharide and inflammatory cytokines levels decreased after sleeve gastrectomy in Chinese adults with obesity

Obesity is linked to a low-grade systemic inflammation and lipopolysaccharide (LPS) is a key factor. Sleeve gastrectomy (SG) can significantly cause weight loss, but few reports have looked into the changes of LPS and inflammatory cytokines after surgery. To explore the potential short-term impact of SG on LPS and inflammatory cytokines and their relationship to early metabolic changes in obesity. 30 Chinese adults with obesity (BMI 39.37 ± 8.22 kg/m², 25 female) receiving SG were included in this study. Fasting blood samples were collected at baseline and 30 days after SG. Serum LPS markedly reduced from 336.50 (73.54, 500) pg/mL to 5.00 (5.00, 5.24) pg/mL at 1 month after SG (p < 0.05). There was a significant decrease in plasma IL-6, IL-8, and serum CRP after SG (all p < 0.05). Insulin resistance improved remarkably after surgery as displayed by reductions in fasting insulin level (FINS, p < 0.001), and HOMA-IR (p < 0.001). In addition, visceral fat area (VFA) decreased from 209.70 ± 39.96 cm² to 193.28 ± 43.68 cm² after SG (p < 0.001). LPS was positively correlated with FINS (r = 0.391, p = 0.033) and HOMA-IR (r = 0.38, p = 0.038) before SG. Meanwhile, VFA was positively associated with CRP (r = 0.388, p = 0.034) before surgery. When assessing 30-days postoperative changes, a positive correlation was found between the variations of LPS, IL-8 and the reduction of VFA. After multivariate analyses, only the reduced IL-8 level was independently associated with the reduction of VFA (p = 0.015). In conclusion, SG can significantly relieve the inflammation in obesity in the short term and LPS might be an earlier predictor of inflammatory changes after surgery.

[Semen quality and fertility: the role of the environment and health]

Sperm quality appears to be degrading over the past 40 years. Nowadays, more than 35 % of causes of male infertility are still idiopathic. More and more studies have suggested an impact of environment on sperm quality, essentially through epigenetic and hormonal changes. Recent studies in men with impaired sperm quality, have demonstrated epigenetic variations in sperm DNA. These modifications are responsible for modifications of the expression of transmissible genes to theiroffspring. Those transgenerational effects have been particularly illustrated in drosophila and caenorhabditis elegans. In humans, consequences of the environment on fertility have been studied in obese men, who present hypogonadotropic as well as hypergonadotropic hypogonadisms. Interestingly, recent studies have suggested a correlation between sperm quality and longevity. In summary, those environmental factors are the source of new causes of infertility.

Association of gut microbial communities with plasma lipopolysaccharide-binding protein (LBP) in premenopausal women

The mechanisms by which obesity increases cancer risk are unclear, but some lines of evidence suggest that gut microbial communities (GMC) may contribute to chronic inflammation in obese individuals through raised systemic levels of lipopolysaccharides (LPS). We evaluated associations of the GMC in stool with plasma LPS-binding protein (LBP, a measure of LPS) and C-reactive protein (CRP) concentrations in 110 premenopausal women in the United States. Diet was assessed using 3-day food records and GMCs were evaluated using pyrosequencing of the 16S rRNA gene. OTUs were identified at 97% sequence similarity. Taxonomic classification and functional genes were imputed from 16S rRNA genes, and alpha and beta diversity were assessed using the Shannon index and MRPP, respectively. Multivariable linear regression analysis was used to assess the relation between LBP, specific bacterial genera identified with indicator species analysis, and CRP. Dietary fat intake, particularly saturated fat, and CRP were positively associated with increased LBP. GMC beta diversity, but not alpha diversity, was statistically significantly different between groups using unweighted Unifrac. Several taxa, particularly those in the Clostridia class, were more prevalent in women with low LBP, while Bacteroides were more prevalent in those with high LBP. Genes associated with gram-negative cell wall material synthesis were also associated with LBP and CRP. In contrast, Phascolarctobacterium was associated with lower concentrations of LBP and CRP. We found distinct differences between tertiles of LBP regarding the diversity and composition of the microbiome, as well as differences in functional genes that potentially activate LBP.

Acute Strenuous Exercise Induces an Imbalance on Histone H4 Acetylation/Histone Deacetylase 2 and Increases the Proinflammatory Profile of PBMC of Obese Individuals

This study evaluated the response of global histone H4 acetylation (H4ac), histone deacetylase 2 (HDAC2) activity, as well as the production of proinflammatory cytokines and monocyte phenotypes of lean and obese males after exercise. Ten lean and ten obese sedentary men were submitted to one session of strenuous exercise, and peripheral blood mononuclear cells (PBMC) were stimulated in vitro with lipopolysaccharide (LPS). Global H4ac levels, HDAC2 activity in PBMC, and IL-6, IL-8, and TNF-α production were analyzed. Monocyte phenotype was determined in accordance with the expression of CD14 and CD16. At rest, obese individuals presented higher frequency of proinflammatory CD14⁺CD16⁺ monocytes. LPS induced a significant augment in global H4ac and in the production of IL-6, IL-8, and TNF-α mainly in obese individuals. After exercise, the increased production of IL-8 and TNF-α and peripheral frequency of CD14⁺CD16⁺ were observed in both groups. In addition, exercise also induced a significant hyperacetylation of histone H4 and decreased HDAC2 activity in both nonstimulated and LPS-stimulated PBMC of obese individuals. Our data indicate that the obesity impacts on H4ac levels and that strenuous exercise leads to an enhanced chronic low-grade inflammation profile in obesity via an imbalance on H4ac/HDAC2.

Exercise reduced pentraxin 3 levels produced by endotoxin-stimulated human peripheral blood mononuclear cells in obese individuals

The purpose of this study was to determine whether obesity would reduce the capacity of peripheral blood mononuclear cells (PBMCs) to produce the anti-inflammatory protein pentraxin 3 (PTX3) in response to ex vivo stimulation with lipopolysaccharide (LPS), and if acute aerobic exercise would enhance this PTX3 production capacity. In addition, the inter-relationships of LPS-induced PTX3 with the inflammatory cytokines (interleukin 6 [IL-6], IL-10, and tumor necrosis factor alpha) were examined. Twenty-one healthy subjects (10 obese and 11 normal-weight) performed an acute bout of aerobic exercise at 75% VO_2max. The capacity of PBMCs to produce PTX3 ex vivo following LPS stimulation was the same in obese and normal-weight subjects at rest, and decreased equally in both subject groups following acute aerobic exercise. This is in contrast to plasma PTX3, which is lower in obese subjects at rest and increased equally in both obese and normal-weight subjects following exercise. In addition, ex vivo PTX3 production was positively associated with IL-6 and IL-10 in response to acute aerobic exercise ( r = 0.686, P = 0.020; r = 0.744, P = 0.009, respectively) in normal-weight, but not in obese individuals ( r = 0.429, P = 0.249; r = 0.453, P = 0.189, respectively). These findings indicate that concentrations of PTX3 observed in plasma are relatively independent of those produced by PBMCs ex vivo and the mechanisms associated with PTX3-mediated anti-inflammatory signaling may differ during obesity. Impact statement Our laboratory has previously demonstrated that obese individuals present with lower plasma concentrations of the anti-inflammatory protein pentraxin 3 (PTX3), whereas acute aerobic exercise increases plasma PTX3 levels similarly compared to normal-weight individuals. As a follow-up, the present study demonstrates that PBMCs isolated from obese and normal-weight individuals produce comparable amounts of PTX3 ex vivo in response to lipopolysaccharide (LPS). Furthermore, given that acute aerobic exercise reduced the ex vivo production of PTX3 in both groups, our results clearly indicate that plasma PTX3 levels are relatively independent of those produced by PBMCs ex vivo. In addition, our findings suggest that the mechanisms associated with PTX3-mediated production of the anti-inflammatory cytokine interleukin 10 may be impaired in obese individuals, and thus provides a key finding necessary for the elucidation of PTX3's role in the mediation of anti-inflammatory profiles and the subsequent amelioration of inflammatory disease during obesity.

Well-being and immune response: a multi-system perspective

Whereas it is well-established that inflammation and other immune responses can change how we feel, most people are still surprised to hear that, conversely, well-being and its violations also affect our immune system. Here we show that those effects are highly adaptive and bear potential for both research and therapeutic applications. The studies discussed in this review demonstrate that immunity is tuned by ones emotions, personality, and social status as well as by other life style variables like sleep, nutrition, obesity, or exercise. We further provide a short excursion on the effects of stress and depression on immunity and discuss acute experimental endotoxemia as a model to study the effects of well-being on the innate immune response in humans.

Glucocorticoid Receptor Mediates the Effect of High-Fat Diet on Mitochondrial Oxidative Phosphorylation in Mouse Liver

Obesity is associated with hepatic mitochondrial dysfunction. The relationship between glucocorticoids (GCs) and obesity has also been demonstrated in several researches. Recent research showed that GCs can affect the mitochondrial function. However, the role of glucocorticoid receptor (GR) in obesity-induced mitochondrial dysfunction remains unclear. C57BL/6 male mice fed with a high-fat diet (HFD) for 7 weeks were used as a model. The mice were shown to be overweight, together with lower serum and hepatic corticosterone levels. The hepatic expressions of mitochondrial DNA (mtDNA)-encoded genes were lower in the HFD mice, same as the mtDNA copy number, ATP content, and COX enzyme activity. Both the translocation of GR (NR3C1) into mitochondria and the binding of GR to the mtDNA were lower in the liver of HFD mice. The PGC1α mRNA expression, protein content, and translocation into mitochondria were also found to be reduced, with the lower GR binding to the promoter region of PGC1α in the liver of HFD mice. GR, as a transcription factor, may take an important role in the regulation of mitochondrial oxidative phosphorylation in the HFD mice by interacting with PGC1α and controlling mtDNA expression.

Benefits of Regular Exercise on Inflammatory and Cardiovascular Risk Markers in Normal Weight, Overweight and Obese Adults

Obesity is a worldwide epidemic that increases the risk of several well-known co-morbidities. There is a complicated relationship between adipokines and low-grade inflammation in obesity and cardiovascular disease (CVD). Physical activity practices have beneficial health effects on obesity and related disorders such as hypertension and dyslipidemia. We investigated the effects of 6 and 12 months of moderate physical training on the levels of adipokines and CVD markers in normal weight, overweight and obese volunteers. The 143 participants were followed up at baseline and after six and twelfth months of moderate regular exercise, 2 times a week, for 12 months. The volunteers were distributed into 3 groups: Normal Weight Group (NWG,), Overweight Group (OVG) and Obese Group (OBG). We evaluated blood pressure, resting heart rate, anthropometric parameters, body composition, fitness capacity (VO_2max and isometric back strength), cardiovascular markers (CRP, total cholesterol, LDL-c, HDL-c, homocysteine) and adipokine levels (leptin, adiponectin, resistin, IL-6 and TNF-alpha). There were no significant changes in anthropometric parameters and body composition in any of the groups following 6 and 12 months of exercise training. Leptin, IL-6 levels and systolic blood pressure were significantly elevated in OBG before the training. Regular exercise decreased HDL-c, leptin, adiponectin and resistin levels and diastolic blood pressure in OVG. In OBG, exercise diminished HDL-c, homocysteine, leptin, resistin, IL-6, adiponectin. Moderate exercise had no effect on the body composition; however, exercise did promote beneficial effects on the low-grade inflammatory state and CVD clinical markers in overweight and obese individuals.

Association of calprotectin with leukocyte chemotactic and inflammatory mediators following acute aerobic exercise

The objective of this study was to examine whether acute aerobic exercise-mediated calprotectin in plasma would be associated with monocyte chemotactic protein-1 (MCP-1), myeloperoxidase (MPO), and interleukin-6 (IL-6) in healthy individuals. Eleven healthy participants, aged 18 to 30 years, were recruited to perform a 30-min bout of aerobic exercise at 75% maximal oxygen uptake. Acute aerobic exercise elicited a significant elevation across time in plasma calprotectin, MCP-1, MPO, and IL-6. Body mass index (BMI) was positively correlated with calprotectin area-under-the-curve with "respect to increase" (AUCi) and IL-6 AUCi. Furthermore, calprotectin AUCi was positively correlated with IL-6 AUCi and MPO AUCi, even after controlling for BMI. Although MPO AUCi was positively correlated with IL-6 AUCi, this relationship no longer existed after controlling for BMI. These results suggest that acute aerobic exercise could mediate innate immune response associated with calprotectin and its related leukocyte chemotactic and inflammatory mediators, especially in individuals with elevated BMI.

Stress induces endotoxemia and low-grade inflammation by increasing barrier permeability

Chronic non-communicable diseases (NCDs) are the leading causes of work absence, disability, and mortality worldwide. Most of these diseases are associated with low-grade inflammation. Here, we hypothesize that stresses (defined as homeostatic disturbances) can induce low-grade inflammation by increasing the availability of water, sodium, and energy-rich substances to meet the increased metabolic demand induced by the stressor. One way of triggering low-grade inflammation is by increasing intestinal barrier permeability through activation of various components of the stress system. Although beneficial to meet the demands necessary during stress, increased intestinal barrier permeability also raises the possibility of the translocation of bacteria and their toxins across the intestinal lumen into the blood circulation. In combination with modern life-style factors, the increase in bacteria/bacterial toxin translocation arising from a more permeable intestinal wall causes a low-grade inflammatory state. We support this hypothesis with numerous studies finding associations with NCDs and markers of endotoxemia, suggesting that this process plays a pivotal and perhaps even a causal role in the development of low-grade inflammation and its related diseases.

Lipopolysaccharide-binding protein and leptin are associated with stress-induced interleukin-6 cytokine expression ex vivo in obesity

Obesity is associated with enhanced inflammation and mental stress, but limited information has addressed the potential additive effect of psychological stress on obesity-associated inflammation. This study examined whether obese subjects would elicit a greater host immune response (IL-6 mRNA and cytokine) to lipopolysaccharide (LPS) in response to mental stress. Blood samples for LPS-stimulated IL-6 mRNA and cytokine were collected prior to and following mental stress. Results showed that obese subjects elicited a greater LPS-induced IL-6 along with its mRNA expression following mental stress compared to normal-weight subjects. Stress-induced IL-6 cytokine response to LPS was correlated with the baseline levels of plasma LPS binding protein (LBP) and leptin. These findings are consistent with the idea that endogenous inflammatory agents (e.g., LBP and leptin), often elevated with obesity, enhance inflammatory responses to psychological stress.