The complex immunological and inflammatory network of adipose tissue in obesity

Hypoxia in Human Obesity: New Insights from Inflammation towards Insulin Resistance-A Narrative Review

Insulin resistance (IR), marked by reduced cellular responsiveness to insulin, and obesity, defined by the excessive accumulation of adipose tissue, are two intertwined conditions that significantly contribute to the global burden of cardiometabolic diseases. Adipose tissue, beyond merely storing triglycerides, acts as an active producer of biomolecules. In obesity, as adipose tissue undergoes hypertrophy, it becomes dysfunctional, altering the release of adipocyte-derived factors, known as adipokines. This dysfunction promotes low-grade chronic inflammation, exacerbates IR, and creates a hyperglycemic, proatherogenic, and prothrombotic environment. However, the fundamental cause of these phenomena remains unclear. This narrative review points to hypoxia as a critical trigger for the molecular changes associated with fat accumulation, particularly within visceral adipose tissue (VAT). The activation of hypoxia-inducible factor-1 (HIF-1), a transcription factor that regulates homeostatic responses to low oxygen levels, initiates a series of molecular events in VAT, leading to the aberrant release of adipokines, many of which are still unexplored, and potentially affecting peripheral insulin sensitivity. Recent discoveries have highlighted the role of hypoxia and miRNA-128 in regulating the insulin receptor in visceral adipocytes, contributing to their dysfunctional behavior, including impaired glucose uptake. Understanding the complex interplay between adipose tissue hypoxia, dysfunction, inflammation, and IR in obesity is essential for developing innovative, targeted therapeutic strategies.

The impact of high-fat diet consumption and inulin fiber supplementation on anxiety-related behaviors and liver oxidative status in female Wistar rats

BACKGROUND

Obesity is a worldwide public health problem associated with cognitive and mental health problems in both humans and rats. Studies assessing the effect of fiber supplementation on behavioral deficits and oxidative stress caused by high-fat diet (HFD) consumption in female rats are still scarce. We hypothesized that HFD consumption would lead to anxiety-related behavior and hepatic oxidative stress and that inulin would protect against these changes. We analyzed the impact of HFD-induced obesity combined with fiber supplementation (inulin) on anxiety-related defensive behavior and hepatic oxidative stress.

RESULTS

Female rats were fed a high-fat diet (HFD; 45%) for nine weeks to induce obesity. The administration of inulin was found to decrease the adiposity index in both the control and obese groups. The consumption of a HFD combined with inulin supplementation resulted in a reduction in both CAT activity and carbonylated protein levels, leading to a shift in the hepatic redox balance. Interestingly, the behavioral data were conflicting. Specifically, animals that consumed a high-fat diet and received inulin showed signs of impaired learning and memory caused by obesity. The HFD did not impact anxiety-related behaviors in the female rats. However, inulin appears to have an anxiolytic effect, in the ETM, when associated with the HFD. On the other hand, inulin appears to have affected the locomotor activity in the HFD in both open field and light-dark box.

CONCLUSION

Our results show that consumption of a HFD induced obesity in female rats, similar to males. However, HFD consumption did not cause a consistent increase in anxiety-related behaviors in female Wistar rats. Treatment with inulin at the dosage used did not exert consistent changes on the behavior of the animals, but attenuated the abdominal WAT expansion and the hepatic redox imbalance elicited by high-fat diet-induced obesity.

Targeting Macrophage Polarization for Reinstating Homeostasis following Tissue Damage

Tissue regeneration and remodeling involve many complex stages. Macrophages are critical in maintaining micro-environmental homeostasis by regulating inflammation and orchestrating wound healing. They display high plasticity in response to various stimuli, showing a spectrum of functional phenotypes that vary from M1 (pro-inflammatory) to M2 (anti-inflammatory) macrophages. While transient inflammation is an essential trigger for tissue healing following an injury, sustained inflammation (e.g., in foreign body response to implants, diabetes or inflammatory diseases) can hinder tissue healing and cause tissue damage. Modulating macrophage polarization has emerged as an effective strategy for enhancing immune-mediated tissue regeneration and promoting better integration of implantable materials in the host. This article provides an overview of macrophages' functional properties followed by discussing different strategies for modulating macrophage polarization. Advances in the use of synthetic and natural biomaterials to fabricate immune-modulatory materials are highlighted. This reveals that the development and clinical application of more effective immunomodulatory systems targeting macrophage polarization under pathological conditions will be driven by a detailed understanding of the factors that regulate macrophage polarization and biological function in order to optimize existing methods and generate novel strategies to control cell phenotype.

Attenuation of PI3K/AKT signaling pathway by Ocimum gratissimum leaf flavonoid-rich extracts in streptozotocin-induced diabetic male rats

Diabetes is a group of medical conditions characterized by the body's inability to effectively control blood glucose levels, due to either insufficient insulin synthesis in type 1 diabetes or inadequate insulin sensitivity in type 2 diabetes. According to this research, the PI3K/AKT pathway of Ocimum gratissimum leaf flavonoid-rich extracts in streptozotocin-induced diabetic rats was studied. We purchased and used a total of forty (40) male Wistar rats for the study. We divided the animals into five (5) different groups: normal control (Group A), diabetic control (Group B), low dose (150 mg/kg body weight) of Ocimum gratissimum flavonoid-rich leaf extract (LDOGFL) (Group C), high dose (300 mg/kg body weight) of Ocimum gratissimum flavonoid-rich leaf extract (HDOGFL) (Group D), and 200 mg/kg of metformin (MET) (Group E). Streptozotocin induced all groups except Group A, which serves as the normal control group. The experiment lasted for 21 days, following which we sacrificed the animals and harvested their brains for biochemical analysis on the 22nd day. We carried out an analysis that included reduced glutathione (GSH), glutathione transferases (GST), catalase (CAT), glutathione peroxidase (GPx), and superoxide dismutase (SOD), along with GLUT4, MDA, pro-inflammatory cytokines, NO, neurotransmitters, cholinergic enzyme activities, cardiolipin, and the gene expression of PI3K/AKT. The obtained result indicates that the flavonoid-rich extracts of O. gratissimum significantly enhanced the levels of GSH, GST, CAT, GPx, and SOD, as well as GLUT4 and cardiolipin. The levels of GSH, GST, CAT, GPx, and SOD, as well as GLUT4 and cardiolipin, were significantly increased by gratissimum. Moreover, the extracts decrease the levels of MDA, pro-inflammatory cytokines, NO, neurotransmitters, and cholinergic enzyme activities. Additionally, the flavonoid-rich extracts of O. gratissimum significantly improved the AKT and PI3K gene expressions in diabetic rats. gratissimum had their AKT and PI3K gene expressions significantly (p < 0.05) improved. The findings indicate that O. gratissimum leaf flavonoids have the potential to treat diabetes mellitus. gratissimum leaf flavonoids possess therapeutic potential in themselves and can be applied in the management of diabetes mellitus. Although further analysis can be carried out in terms of isolating, profiling, or purifying the active compounds present in the plant's extract.

Self-assembled peptide hydrogels for the treatment of diabetes and associated complications

Diabetes is a widespread epidemic that includes a number of comorbid conditions that greatly increase the chance of acquiring other chronic illnesses. Every year, there are significantly more people with diabetes because of the rise in type-2 diabetes prevalence. The primary causes of illness and mortality worldwide are, among these, hyperglycemia and its comorbidities. There has been a lot of interest in the creation of peptide-based hydrogels as a potentially effective platform for the treatment of diabetes and its consequences. Here, we emphasize the use of self-assembled hydrogel formulations and their unique potential for the treatment/management of type-2 diabetes and its consequences. (i.e., wounds). Key aspects covered include the characteristics of self-assembled peptide hydrogels, methods for their preparation, and their pre-clinical and clinical applications in addressing metabolic disorders such as type-2 diabetes.

Association of Dietary Protein Sources and Their Adequacy, Body Composition and Risk of Sarcopenic Obesity in South Korean Populations: A Cross-Sectional Study

Dietary protein sources and protein adequacy are crucial modulators of muscle quality and body composition. We investigated the association between dietary protein sources (and their adequacy) and body composition and the risk of sarcopenic obesity (SO) in South Korean populations. The participants (n = 1967) were classified into SO, obese, sarcopenia, and normal groups. A cross-sectional survey was conducted using the KS-15 questionnaire, short-form food frequency questionnaire, and anthropometric measurements. The percentage of body fat (male: 35.36 ± 0.51%; female: 44.14 ± 0.36%) was significantly high, while appendicular skeletal muscle (ASM; male: 36.39 ± 0.30%, female: 30.32 ± 0.19%) was low in the SO group. Beef and pork consumption was negatively associated with ASM (%) but positively associated with body fat (%) in the normal group and positively associated with ASM (kg/m2: beta = 0.002, p = 0.02) and BFM (kg: beta = 0.012, p = 0.03) in the SO group, respectively. The highest quintile (Q5: 173.6 g/day) showed a decreased risk of SO prevalence (AORs: 0.46, CI: 0.22-0.94) compared with that in the lowest quintile (Q1: 21.6 g/day) among the people with inadequacy protein intake. Daily poultry and egg intake was positively linked with body composition in the participants with SO, while red meat showed a negative effect on imbalanced body composition in participants in the normal and SO groups. Furthermore, a lower intake of poultry and eggs was strongly associated with SO prevalence in people who consumed inadequate amounts of daily dietary protein.

Disparities in Breast Cancer Care-How Factors Related to Prevention, Diagnosis, and Treatment Drive Inequity

Breast cancer survival has increased significantly over the last few decades due to more effective strategies for prevention and risk modification, advancements in imaging detection, screening, and multimodal treatment algorithms. However, many have observed disparities in benefits derived from such improvements across populations and demographic groups. This review summarizes published works that contextualize modern disparities in breast cancer prevention, diagnosis, and treatment and presents potential strategies for reducing disparities. We conducted searches for studies that directly investigated and/or reported disparities in breast cancer prevention, detection, or treatment. Demographic factors, social determinants of health, and inequitable healthcare delivery may impede the ability of individuals and communities to employ risk-mitigating behaviors and prevention strategies. The disparate access to quality screening and timely diagnosis experienced by various groups poses significant hurdles to optimal care and survival. Finally, barriers to access and inequitable healthcare delivery patterns reinforce inequitable application of standards of care. Cumulatively, these disparities underlie notable differences in the incidence, severity, and survival of breast cancers. Efforts toward mitigation will require collaborative approaches and partnerships between communities, governments, and healthcare organizations, which must be considered equal stakeholders in the fight for equity in breast cancer care and outcomes.

Wnt10b knockdown regulates the relative balance of adipose tissue-resident T cells and inhibits white fat deposition

BACKGROUND

Wnt10b is one of critical Wnt family members that being involved in networks controlling stemness, pluripotency and cell fate decisions. However, its role in adipose-resident T lymphocytes and further in fat metabolism yet remains largely unknown.

METHODS AND RESULTS

In the present study, we demonstrated a distinctive effect for Wnt10b on the relative balance of T lymphocytes in adipose tissue by using a Wnt10b knockdown mouse model. Wnt10b knockdown led to a reduction of adipose-resident CD4+ T cells and an elevation of Foxp3+/CD4+ Treg cells. Wnt10b-knockdown mice fed with standard diet showed less white fat deposition owing to the suppressed adipogenic process. Moreover, under high fat diet conditions, Wnt10b knockdown resulted in an alleviated obesity symptoms, as well as an improvement of glucose homeostasis and hepatic steatosis.

CONCLUSIONS

Collectively, we reveal an unexpected and novel function for Wnt10b in mediating the frequency of adipose-resident T cell subsets, that when knockdown skewing toward a Treg-dominated phenotype and further improving fat metabolism.

Obesity-related asthma and its relationship with microbiota

Obesity and asthma are global public health problems. Obesity-related asthma is a special phenotype of asthma with a complex pathogenesis. Its occurrence and development are related to mechanical compression, inflammatory response, metabolic regulation, gene regulation, and vitamin D deficiency. Different treatment strategies used in the process of weight loss have a beneficial impact on asthma. Alterations in gut and airway microbial community structure and their metabolites may also contribute to obesity-related asthma. The role of the Th17/Treg balance in the gut microbiota regulating the immune responses and host metabolism is important. Therapeutic measures associated with the gut microbiota variety may contribute to improving chronic inflammation associated with obesity by regulating the Th17/Treg balance. An early reduction in microbial diversity can predict the development of asthma and lead to allergy through an imbalance of Th2/Th1 responses. Short-chain fatty acids (SCFAs) regulate the differentiation and activation of regulatory T cells, thereby regulating immune homeostasis in the lung to suppress allergic inflammation and weight gain. Therefore, clarifying the microbial mechanism of obesity-related asthma has important guiding significance for clinical treatment. In this review, we used the following terms: "asthma and obesity" and "obesity-related asthma", combining "phenotype", "airway inflammation" and "lung function", and reviewed the characteristics and pathogenesis of obesity-related asthma, the relationship between the gut and airway microbiota and obesity-related asthma, and the current treatment measures for the disease.

Increased monocytes are associated with overweight in children and adolescents with autism spectrum disorder

Introduction

Objective: to investigate the monocyte count and its association with nutritional status in children and adolescents with autism spectrum disorder (ASD). Methods: a cross-sectional study carried out at a Neurodevelopmental Center in the south of Brazil, with 68 ASD patients aged 3 to 18 years. The number of monocytes (per mm3) was determined in blood samples. Nutritional status was defined as BMI-for-age according to WHO standards. The Children's Eating Behaviour Questionnaire and a standard questionnaire to collect sociodemographic and clinical characteristics were administered to caregivers. Comparisons between sociodemographic, clinical, and eating behavior variables were performed with parametric tests. Linear regression was used to test the association between nutritional status and monocyte count. Results: mean age was 8.6 ± 3.3 years, 79 % were males and 66 % were overweight. In the unadjusted regression overweight was associated with higher monocyte counts compared to those non-overweight (B: 64.0; 95 % CI, 13.9 to 114.1; β: 0.30, p = 0.01). This association remained significant after adjustment for the subscale of "emotional overeating" (B: 37.0; 95 % CI, 17.1 to 91.3; β: 0.29; p = 0.02). The variability in monocyte count attributed to overweight was 14 %. Conclusions: overweight is associated with a higher monocyte count in children and adolescents with ASD. Nutritional intervention to control overweight is essential to mitigate the negative impact on inflammatory activity and immune dysfunction in these patients.

Intermittent vs. continuous swimming training on adipokines and pro-inflammatory cytokines in metabolic syndrome experimental model

OBJECTIVES

In this study, metabolic syndrome-affected rats were studied to examine how intermittent and continuous swimming training influenced adipokines and pro-inflammatory cytokines.

METHODS

Forty-eight male Wistar rats were randomized in this experimental study into four groups (n=8), including normal control (NC), metabolic syndrome (MS), continuous swimming training with metabolic syndrome (CT-MS: load 0-3% body mass, 5 d/wk, for 8 weeks), and intermittent swimming training with metabolic syndrome (IT-MS: load 5-16% body mass, 5 d/wk, for 8 weeks). The serum levels of metrnl, adipolin, irisin, leptin, TNF-α, and IL-6 were measured using the ELISA test.

RESULTS

The IT-MS and NC groups exhibited significantly lower leptin concentrations than the CT-MS group (p=0.001). The irisin, meteorin, and adipolin serum levels increased significantly in CT-MS and IT relative to the NC and CT-MS groups (p=0.001), with the changes being more pronounced in the IT group (p=0.05). TNF-α and IL-6 were inclined in the CT-MS group compared with the other three groups (p=0.001), while IL-6 was increased in the IT group (p=0.024).

CONCLUSIONS

Intermittent swimming is more effective than continuous swimming training in improving adipokines in rats with metabolic syndrome.

Salacia reticulata Extract Suppresses Fat Accumulation by Regulating Lipid Metabolism

The excessive storage of triglycerides in adipose tissue is a characteristic feature of obesity, which arises from an imbalance between energy intake and expenditure. In this study, we aimed to explore the potential anti-obesity effects of Salacia reticulata extracts (SC) in a high-fat diet (HFD)-induced in obese mice and 3T3-L1 adipocytes, with a specific focus on understanding the underlying lipid mechanisms. Mice were fed with a normal diet (NC; normal control), HFD (60% high-fat diet), Met (HFD containing metformin 250 mg/kg b.w.), SC25 (HFD containing SC 25 mg/kg b.w.), SC50 (HFD containing SC 50 mg/kg b.w.), or SC 100 (HFD containing SC 100 mg/kg b.w.) for 12 weeks. Notably, SC supplementation led to significant reductions in body weight gain, adipose tissue weight, adipose tissue mass, and adipocyte size in HFD-fed mice. Furthermore, SC supplementation exerted inhibitory effects on the adipogenesis and lipogenesis pathways while promoting lipolysis and thermogenesis pathways in the adipose tissues of HFD-fed mice. In vitro experiments using 3T3-L1 cells demonstrated that SC treatment during the differentiation phase suppressed adipogenesis and lipogenesis, whereas SC treatment after differentiation, activated lipolysis and thermogenesis. Collectively, these findings indicate that SC exhibits a direct influence on the lipid metabolism of adipocytes, making it an effective candidate for weight loss interventions.

Physical exercise, health, and disease treatment: The role of macrophages

Subclinical inflammation is linked to comorbidities and risk factors, consolidating the diagnosis of chronic non-communicable diseases, such as insulin resistance, atherosclerosis, hepatic steatosis, and some types of cancer. In this context, the role of macrophages is highlighted as a marker of inflammation as well as for the high power of plasticity of these cells. Macrophages can be activated in a wide range between classical or proinflammatory, named M1, and alternative or anti-inflammatory, also known as M2 polarization. All nuances between M1 and M2 macrophages orchestrate the immune response by secreting different sets of chemokines, while M1 cells promote Th1 response, the M2 macrophages recruit Th2 and Tregs lymphocytes. In turn, physical exercise has been a faithful tool in combating the proinflammatory phenotype of macrophages. This review proposes to investigate the cellular and molecular mechanisms in which physical exercise can help control inflammation and infiltration of macrophages within the non-communicable diseases scope. During obesity progress, proinflammatory macrophages predominate in adipose tissue inflammation, which reduces insulin sensitivity until the development of type 2 diabetes, progression of atherosclerosis, and diagnosis of non-alcoholic fatty liver disease. In this case, physical activity restores the balance between the proinflammatory/anti-inflammatory macrophage ratio, reducing the level of meta-inflammation. In the case of cancer, the tumor microenvironment is compatible with a high level of hypoxia, which contributes to the advancement of the disease. However, exercise increases the level of oxygen supply, favoring macrophage polarization in favor of disease regression.

Interaction Between Adipocytes and B Lymphocytes in Human Metabolic Diseases

Diseases associated with the disorders of carbohydrate and lipid metabolism are widespread in the modern world. Interaction between the cells of adipose tissue - adipocytes - and immune system cells is an essential factor in pathogenesis of such diseases. Long-term increase in the glucose and fatty acid levels leads to adipocyte hypertrophy and increased expression of pro-inflammatory cytokines and adipokines by these cells. As a result, immune cells acquire a pro-inflammatory phenotype, and new leukocytes are recruited. Inflammation of adipose tissue leads to insulin resistance and stimulates formation of atherosclerotic plaques and development of autoimmunity. New studies show that different groups of B lymphocytes play an essential role in regulation of adipose tissue inflammation. Decrease in the number of B-2 lymphocytes suppresses development of a number of metabolic diseases, whereas decreased numbers of the regulatory B lymphocytes and B-1 lymphocytes are associated with more severe pathology. Recent studies showed that adipocytes influence B lymphocyte activity both directly and by altering activity of other immune cells. These findings provide better understanding of the molecular mechanisms of human pathologies associated with impaired carbohydrate and lipid metabolism, such as type 2 diabetes mellitus.

The crucial role and mechanism of insulin resistance in metabolic disease

Insulin resistance (IR) plays a crucial role in the development and progression of metabolism-related diseases such as diabetes, hypertension, tumors, and nonalcoholic fatty liver disease, and provides the basis for a common understanding of these chronic diseases. In this study, we provide a systematic review of the causes, mechanisms, and treatments of IR. The pathogenesis of IR depends on genetics, obesity, age, disease, and drug effects. Mechanistically, any factor leading to abnormalities in the insulin signaling pathway leads to the development of IR in the host, including insulin receptor abnormalities, disturbances in the internal environment (regarding inflammation, hypoxia, lipotoxicity, and immunity), metabolic function of the liver and organelles, and other abnormalities. The available therapeutic strategies for IR are mainly exercise and dietary habit improvement, and chemotherapy based on biguanides and glucagon-like peptide-1, and traditional Chinese medicine treatments (e.g., herbs and acupuncture) can also be helpful. Based on the current understanding of IR mechanisms, there are still some vacancies to follow up and consider, and there is also a need to define more precise biomarkers for different chronic diseases and lifestyle interventions, and to explore natural or synthetic drugs targeting IR treatment. This could enable the treatment of patients with multiple combined metabolic diseases, with the aim of treating the disease holistically to reduce healthcare expenditures and to improve the quality of life of patients to some extent.

Two-sided roles of adipose tissue: Rethinking the obesity paradox in various human diseases from a new perspective

Overweight and obesity, as a result of excess fat accumulation, have become a worldwide public health issue. Recent studies have shown that obesity is closely related to many human diseases, such as cancer, cardiovascular diseases, and type 2 diabetes mellitus, in which adipose tissue plays a dual role. In addition to thermal and mechanical insulation and a critical role in energy storage and heat production, adipose tissue is also a highly plastic endocrine and signaling organ that secretes multiple bioactive molecules for inter-organ crosstalk. The phenotypic and biological changes of adipose tissue under pathological conditions, especially in obesity, increase the challenge of deciphering the positive or negative effects of adipose tissue in disease. Despite numerous studies on obesity and adipose tissue, the ambiguous role of adipose tissue on specific organs or tissues in different diseases is not fully understood, and the definite mechanisms remain obscure. In this review, we first summarize the basic biological characteristics of adipose tissue in the physiological state and the abnormal remodeling of adipose tissue during obesity. We then discuss the complex and disparate effects of obesity on various human diseases, with a particular focus on the dual roles and underlying mechanisms of adipose tissue, a quintessential player in obesity, in this process. More importantly, rethinking the causes of the "obesity paradox" phenomenon in diseases from the perspective of adipose homeostasis and dysfunction provides a novel strategy for disease treatment by intervening in fat function.

Leptin and Asthma: What Are the Interactive Correlations?

Leptin is an adipokine directly correlated with the proinflammatory obese-associated phenotype. Leptin has been demonstrated to inhibit adipogenesis, promote fat demarcation, promote a chronic inflammatory state, increase insulin sensitivity, and promote angiogenesis. Leptin, a regulator of the immune response, is implicated in the pathology of asthma. Studies involved in the key cell reaction and animal models of asthma have provided vital insights into the proinflammatory role of leptin in asthma. Many studies described the immune cell and related cellular pathways activated by leptin, which are beneficial in asthma development and increasing exacerbations. Subsequent studies relating to animal models support the role of leptin in increasing inflammatory cell infiltration, airway hyperresponsiveness, and inflammatory responses. However, the conclusive effects of leptin in asthma are not well elaborated. In the present study, we explored the general functions and the clinical cohort study supporting the association between leptin and asthma. The main objective of our review is to address the knowns and unknowns of leptin on asthma. In this perspective, the arguments about the different faces of leptin in asthma are provided to picture the potential directions, thus yielding a better understanding of asthma development.

Immune response to arbovirus infection in obesity

Obesity is a global health problem that affects 650 million people worldwide and leads to diverse changes in host immunity. Individuals with obesity experience an increase in the size and the number of adipocytes, which function as an endocrine organ and release various adipocytokines such as leptin and adiponectin that exert wide ranging effects on other cells. In individuals with obesity, macrophages account for up to 40% of adipose tissue (AT) cells, three times more than in adipose tissue (10%) of healthy weight individuals and secrete several cytokines and chemokines such as interleukin (IL)-1β, chemokine C-C ligand (CCL)-2, IL-6, CCL5, and tumor necrosis factor (TNF)-α, leading to the development of inflammation. Overall, obesity-derived cytokines strongly affect immune responses and make patients with obesity more prone to severe symptoms than patients with a healthy weight. Several epidemiological studies reported a strong association between obesity and severe arthropod-borne virus (arbovirus) infections such as dengue virus (DENV), chikungunya virus (CHIKV), West Nile virus (WNV), and Sindbis virus (SINV). Recently, experimental investigations found that DENV, WNV, CHIKV and Mayaro virus (MAYV) infections cause worsened disease outcomes in infected diet induced obese (DIO) mice groups compared to infected healthy-weight animals. The mechanisms leading to higher susceptibility to severe infections in individuals with obesity remain unknown, though a better understanding of the causes will help scientists and clinicians develop host directed therapies to treat severe disease. In this review article, we summarize the effects of obesity on the host immune response in the context of arboviral infections. We have outlined that obesity makes the host more susceptible to infectious agents, likely by disrupting the functions of innate and adaptive immune cells. We have also discussed the immune response of DIO mouse models against some important arboviruses such as CHIKV, MAYV, DENV, and WNV. We can speculate that obesity-induced disruption of innate and adaptive immune cell function in arboviral infections ultimately affects the course of arboviral disease. Therefore, further studies are needed to explore the cellular and molecular aspects of immunity that are compromised in obesity during arboviral infections or vaccination, which will be helpful in developing specific therapeutic/prophylactic interventions to prevent immunopathology and disease progression in individuals with obesity.

High Visceral Fat is Associated with a Worse Survival after Liver Resection for Intrahepatic Cholangiocarcinoma

The impact of body composition (BC) on the prognosis of resected intrahepatic cholangiocarcinoma (ICC) has been poorly studied. Aims: i) to evaluate the prevalence of low muscle mass (MM) in patients; ii) to assess the impact of BC on patient overall survival (OS) and disease-free survival (DFS), and iii) on the incidence of postoperative complications. All consecutive patients who underwent liver resection for ICC between 2004 and 2016 and who had preoperative CT scans were included. Ninety-three patients were included. Sixty percent (55/91) had low total MM. On multivariable analysis, high visceral fat (HR 2.48, CI95% [1.63; 3.77], p < 0.0001), nodules >1 (HR 3.15 [1.67; 5.93], p = 0.0004), involvement adjacent organ (HR 6.67 [1.88; 23.69], p = 0.003), and postoperative sepsis (HR 3.04 [1.54; 5.99], p = 0.0013) were independently associated with OS. High visceral fat (HR 2.10 [1.31; 3.38], p = 0.002], nodules >1 (HR 3.01, [1.49; 6.10], p = 0.002), postoperative sepsis (HR 5.16 [2.24; 11.89], p = 0.0001), ASA score (p = 0.02) and perineural invasion (HR 3.30 [1.62; 6.76], p = 0.001) were independently associated with lower DFS. Conclusion: 60% of ICC patients had low MM before surgery. High visceral fat, but not muscle mass, was an independent prognostic factor for poor OS and DFS in European patients with resected ICC.

Obesity in HIV infection: host-pathogen interaction

OBJECTIVE

Both obesity and HIV infection are characterized by a state of chronic inflammation associated with increased morbidity and mortality. This review aims to assess the available literature on immune dysregulation in obesity and people with HIV infection (PWH).

DESIGN

A systematic review of peer-reviewed literature.

METHODS

We conducted a systematic literature search of PubMed, Embase, Scopus, and international conference abstracts for articles on the epidemiology of obesity in the general population and in PWH and the pathogenesis of obesity with a focus on inflammation and immune activation.

RESULTS

Of the 631 articles selected after title review, 490 met the inclusion criteria and 90 were included in the final selection. The selected studies highlight the increasing prevalence of obesity in PWH and a substantial role for antiretroviral treatment (ART) in its development. Pathogenesis of obesity and its associated inflammation derives from disturbances in adipose tissue (AT) immune function, focused on T-cell and macrophage function, with a switch to pro-inflammatory immune phenotype and resulting increases in pro-inflammatory chemokines, which contribute to the development of metabolic syndrome. Although dysregulation of these pathways is seen in both obesity and HIV, there remains a lack of human studies on AT inflammation in HIV.

CONCLUSION

Obesity is an emerging comorbidity in PWH, with a substantial overlap in immune dysregulation patterns seen in both conditions. How this immune dysfunction impacts on development of metabolic complications for both obesity and HIV infection, and whether targeting of AT-derived inflammation will improve outcomes in PWH requires further study.

Body Mass Index and Risk of Diabetic Nephropathy: A Mendelian Randomization Study

CONTEXT

The associations of obesity and diabetic nephropathy (DN) in type 2 diabetes are inconsistent in observational studies, and causality remains unclear.

OBJECTIVE

To explore the causal effect of body mass index (BMI) on DN, estimated glomerular filtration rate (eGFR), and proteinuria in type 2 diabetes by a 2-sample Mendelian randomization (MR) analysis.

METHODS

A total of 56 genetic variants were selected as instrumental variables for BMI in 158 284 participants from BioBank Japan, and their effects on DN risk, eGFR, and proteinuria were estimated in 3972 individuals with type 2 diabetes. Then, sex-stratified MR analysis was performed between BMI and DN. We selected generalized summary MR analysis as the primary method and 6 other robust methods to test MR assumptions.

RESULTS

One SD increase in BMI was causally associated with higher DN risk [odds ratio (OR) 3.76, 95% CI 1.88-7.53, P < 0.001] and lower eGFR level (OR 0.71, 95% CI 0.59-0.86, P < 0.001). However, BMI was not causally associated with proteinuria (P = 0.22). Sex-stratified analyses indicated the causal effect of BMI on DN was stronger in women (OR 14.81, 95% CI 2.67-82.05, P = 0.002) than in men (OR 3.48, 95% CI 1.18-10.27, P = 0.02). Sensitivity analyses did not show evidence for violation of the MR assumptions.

CONCLUSIONS

Genetic evidence showed that higher BMI levels were causally associated with increased risk of DN and decreased eGFR levels. Moreover, the increase in BMI level had a greater impact on DN risk in women.

A Comparative Study on the Adipogenic Differentiation of Mesenchymal Stem/Stromal Cells in 2D and 3D Culture

Mesenchymal stem/stromal cells (MSC) are capable of renewing the progenitor cell fraction or differentiating in a tissue-specific manner. Adipogenic differentiation of adipose-tissue-derived MSC (adMSC) is important in various pathological processes. Adipocytes and their progenitors are metabolically active and secrete molecules (adipokines) that have both pro- and anti-inflammatory properties. Cell culturing in 2D is commonly used to study cellular responses, but the 2D environment does not reflect the structural situation for most cell types. Therefore, 3D culture systems have been developed to create an environment considered more physiological. Since knowledge about the effects of 3D cultivation on adipogenic differentiation is limited, we investigated its effects on adipogenic differentiation and adipokine release of adMSC (up to 28 days) and compared these with the effects in 2D. We demonstrated that cultivation conditions are crucial for cell behavior: in both 2D and 3D culture, adipogenic differentiation occurred only after specific stimulation. While the size and structure of adipogenically stimulated 3D spheroids remained stable during the experiment, the unstimulated spheroids showed signs of disintegration. Adipokine release was dependent on culture dimensionality; we found upregulated adiponectin and downregulated pro-inflammatory factors. Our findings are relevant for cell therapeutic applications of adMSC in complex, three-dimensionally arranged tissues.

Risk of hospitalization and mortality due to COVID-19 in people with obesity: An analysis of data from a Brazilian state

The aim of this article is to assess the odds ratio of hospitalization and mortality due to COVID-19 in people with obesity using data from residents of Espírito Santo, Brazil. An observational, quantitative, cross-sectional study was carried out from the database available on the official channel of the State Health Secretariat of Espírito Santo. Crude odds ratio estimates (ORs) referring to the association between variables were calculated, as well as adjusted odds ratios (adjusted odds ratios—OR adj.) and their respective 95% confidence intervals (CI 95%). The results indicate that men, non-white, no education or with lower education level and age over 40 years old were more likely to be hospitalized and died of COVID-19. People with obesity are at risk of hospitalization and death due to COVID-19 54% and 113% higher than people who do not have obesity. People with obesity had a higher chance of hospitalization when they were over 40 years old, had breathing difficulty, and the comorbidities diabetes (2.18 higher) and kidney disease (4.10 higher). The odds ratio of death for people with obesity over 60 years old was 12.51 higher, and those who were hospitalized was 17.9 higher compared to those who were not hospitalized.

Immunometabolic adaptation and immune plasticity in pregnancy and the bi-directional effects of obesity

Mandatory maternal metabolic and immunological changes are essential to pregnancy success. Parallel changes in metabolism and immune function make immunometabolism an attractive mechanism to enable dynamic immune adaptation during pregnancy. Immunometabolism is a burgeoning field with the underlying principle being that cellular metabolism underpins immune cell function. With whole body changes to the metabolism of carbohydrates, protein and lipids well recognised to occur in pregnancy and our growing understanding of immunometabolism as a determinant of immunoinflammatory effector responses, it would seem reasonable to expect immune plasticity during pregnancy to be linked to changes in the availability and handling of multiple nutrient energy sources by immune cells. While studies of immunometabolism in pregnancy are only just beginning, the recognised bi-directional interaction between metabolism and immune function in the metabolic disorder obesity might provide some of the earliest insights into the role of immunometabolism in immune plasticity in pregnancy. Characterised by chronic low-grade inflammation including in pregnant women, obesity is associated with numerous adverse outcomes during pregnancy and beyond for both mother and child. Concurrent changes in metabolism and immunoinflammation are consistently described but any causative link is not well established. Here we provide an overview of the metabolic and immunological changes that occur in pregnancy and how these might contribute to healthy versus adverse pregnancy outcomes with special consideration of possible interactions with obesity.

Sarcopenic Obesity with Normal Body Size May Have Higher Insulin Resistance in Elderly Patients with Type 2 Diabetes Mellitus

OBJECTIVE

Data are limited regarding how body composition is linked to insulin resistance in elderly patients with type 2 diabetes mellitus (T2DM). We examined the association between body composition and insulin resistance in elderly T2DM patients.

METHODS

The cross-sectional study included 488 Chinese elderly patients wth T2DM. Subjects were classified into four groups based on body composition: normal body composition (NBC), low muscle mass alone (LMM), high body fat alone (HBF), both low muscle mass and high body fat (LMMHBF).

RESULTS

The percentage of subjects with LMMHBF was 14.5% (11.9% in men and 17.7% in women). Homeostasis model assessment of insulin resistance (HOMA2-IR) was higher in the LMMHBF group than in the HBF group (p = 0.045), and was also significantly higher in the LMMHBF or HBF group than in the NBC or LMM group. The HBF group showed the highest body mass index (BMI) of the four groups of different body compositions, and the LMMHBF group showed lower BMI than the HBF group; however, there was no significant difference in BMI or waist to hip ratio (WHR) between the LMMHBF group and the NBC group. The LMMHBF and HBF groups were significantly associated with increased risk of insulin resistance compared to the NBC group, with odds ratios (ORs) of 4.47 [95% confidence interval (CI) 2.06-9.68, p < 0.001] and 1.76 (95% CI 1.02-3.02, p = 0.041) respectively, even after the adjustment for covariates.

CONCLUSION

In China, though elderly T2DM patients with the body composition of sarcopenic obesity (as defined by coexistence of low muscle mass and high body fat) seemed to have normal body size, they exhibited the most severe degree and the highest risk of insulin resistance.

The dietary inflammatory index, obesity, type 2 diabetes, and cardiovascular risk factors and diseases

An unhealthy diet is a recognized risk factor in the pathophysiology of numerous chronic noncommunicable diseases (NCD), including obesity, type 2 diabetes (T2DM), and cardiovascular diseases (CVD). This is, at least in part, due to unhealthy diets causing chronic low-grade inflammation in the gut and systemically. To characterize the inflammatory potential of diet, we developed the Dietary Inflammatory Index (DII®). Following this development, around 500 papers have been published, which examined the association between the DII, energy-adjusted DII (E-DII™), and the children's DII (C-DII™) and many chronic NCDs including obesity and cardiometabolic diseases. Although a previous narrative review published in 2019 briefly summarized the evidence in this area, there was a significant increase in papers on this topic since 2020. Therefore, the purpose of this narrative review is to provide an in-depth updated review by including all papers until July 2021 on DII and its relationship with obesity, T2DM, and CVD. Furthermore, we aim to identify potential gaps in the literature and provide future directions for research. Most studies found that DII was associated with an increased risk of obesity, T2DM, and CVD with some relationships being sex-specific. However, we identified the paucity of papers describing associations between dietary inflammation and T2DM and its risk factors. Few studies used gold-standard measures of cardiometabolic risk factors. We also identified the lack of interventional studies designed to change the inflammatory potential of diets and study its effect on cardiometabolic risk factors and diseases. We recommend that such interventional studies are needed to assess if changes in DII, representing the inflammatory potential of diet, independently of changes in body composition can modulate cardiometabolic risk factors and diseases.

Modestly Increased Incidence of Ketosis in Caloric Restriction Does not Significantly Alter the Effects of Caloric Restriction

OBJECTIVES

Caloric restriction (CR) has been shown to slow the aging processes in a number of preclinical studies and reduces expression of aging-associated biomarkers in human trials. We hypothesized that CR would lead to increased incidence of ketosis and that ketosis in CR individuals would alter the aging-protective effects of CR or biomarkers thereof.

DESIGN/SETTING/PARTICIPANTS

We analyzed data from the "Comprehensive Assessment of Long-Term Effects of Reducing Intake of Energy (CALERIE, Phase 2)" Public Use Database available at calerie.duke.edu. In this study, non-obese adults between the ages of 21 and 50 were randomized to 25% CR or control (ad lib) diet groups and extensively monitored for two years. Given our focus on the effect of caloric restriction on ketosis, individuals with detectible ketones during the baseline visit (pre-randomization) and those with missing data for ketone testing were excluded from the analysis, leaving 71 control and 117 CR participants.

MEASUREMENTS

We analyzed the incidence of ketosis as well as ketosis free survival in control and CR participants and assessed the effect of ketosis on a number of clinical lab values, functional assessments, and participant survey data related to aging biology.

RESULTS

We report that CR was associated with modestly increased incidence of ketosis (4.4% in CR vs 1.9% in control), though CR-associated changes in T3, VO2, SUMPT-WT (weight normalized composite strength score - peak torque), physical functioning, and general health did not appear to be altered by the presence or absence of ketosis. Additional observations of interest include: 1) striking patterns of biomarker expression changes (MCP-1, TNFα, TGF-β1, GH) in both the control and CR participants between the baseline visit and the 24-month post-randomization visit and 2) pro-growth/anti-inflammatory baseline (pre-randomization) biomarker expression profile in CR individuals that later test ketone positive relative to other CR individuals.

CONCLUSIONS

CR modestly increases the incidence of ketosis in healthy adults, yet the increase in ketosis in CR patients did not significantly affect the aging-protective effects of CR. However, given the relatively small number of participants who were ketone positive, further investigation in larger study cohorts is still required for definitive conclusions.

Pediatric Obesity-Related Asthma: The Role of Nutrition and Nutrients in Prevention and Treatment

Childhood obesity rates have dramatically risen in numerous countries worldwide. Obesity is likely a factor in increased asthma risk, which is already one of the most widespread chronic respiratory pathologies. The pathogenic mechanism of asthma risk has still not yet been fully elucidated. Moreover, the role of obesity-related inflammation and pulmonary overreaction to environmental triggers, which ultimately result in asthma-like symptoms, and the importance of dietary characteristics is well recognized. Diet is an important adjustable element in the asthma development. Food-specific composition of the diet, in particular fat, sugar, and low-quality nutrients, is likely to promote the chronic inflammatory state seen in asthmatic patients with obesity. An unbalanced diet or supplementation as a way to control asthma more efficiently has been described. A personalized dietary intervention may improve respiratory symptoms and signs and therapeutic response. In this narrative review, we presented and discussed more recent literature on asthma associated with obesity among children, focusing on the risk of asthma among children with obesity, asthma as a result of obesity focusing on the role of adipose tissue as a mediator of systemic and local airway inflammation implicated in asthma regulation, and the impact of nutrition and nutrients in the development and treatment of asthma. Appropriate early nutritional intervention could possibly be critical in preventing and managing asthma associated with obesity among children.

Respiratory burden in obese and young asthmatics: a study of diaphragmatic kinetics

Objective

The aim of this study was to assess the diaphragm kinetics, respiratory function, and serum dosage of leptin and inflammatory cytokines (IL-6 and TNF-α) in three clinical groups: obese, asthmatic, and healthy.

Methods

This is a clinical exploratory study performed on 73 youths (12-24 years of age, 42.5% male) allocated into three groups: obesity (OG, n=33), body mass index (BMIz-score) ≥ +2, asthmatic (AG, n=26) controlled mild asthmatics, classified by GINA, and Healthy Control Group (CG, n=14). The participants were subjected to diaphragmatic ultrasound, spirometry, maximal respiratory pressure, serum leptin levels, and IL-6 and TNF-α whole blood cell culture levels.

Results

Diaphragm thickness was higher in OG in comparison to AG and CG (2.0±0.4 vs 1.7±0.5 and 1.6±0.2, both with p<0.05). Maximal voluntary ventilation (MVV) was significantly lower in OG and AG in relation to the CG (82.8±21.4 and 72.5±21.2 vs 102.8±27.3, both with p<0.05). OG has the highest leptin rate among the groups (with the other two groups had p<0.05). All groups had similar TNF-α and IL-6 levels.

Conclusion

The muscular hypertrophy found in the diaphragm of the obese individuals can be justified by the increase in respiratory work imposed by the chronic condition of the disease. Such increase in thickness did not occur in controlled mild asthmatics. The IL-6 and TNF-α markers detected no evidence of muscle inflammation, even though leptin was expected to be altered in obese individuals. Both obese and asthmatic patients had lower pulmonary resistance than the healthy ones.

Mucosal-Associated Invariant T Cell Response to Acute Exercise and Exercise Training in Older Obese Women

(1) Background: Obesity is a major global public health concern as it is associated with many of the leading causes of preventable deaths. Exercise reduces obesity-induced inflammation; however, it is unknown how exercise training may impact mucosal associated invariant T (MAIT) cells in overweight/obese (OW) post-menopausal women. Therefore, the purpose of this study was to investigate (i) circulating MAIT-cells at rest in OW vs. Lean women, (ii) the response of MAIT-cells to a single bout of combined aerobic and resistance exercise, and (iii) the effects of 12 weeks of exercise training (EX) or educational program (ED) on the MAIT-cell response in OW. (2) Methods: OW completed an acute exercise session or sitting control, underwent 12 weeks of exercise training or received educational materials, and then repeated the exercise session/sitting control. Lean post-menopausal women provided a baseline comparison. (3) Results: OW had lower circulating MAIT-cells at rest than Lean prior to exercise training; however, after training EX displayed improved MAIT-cell frequency. Additionally, prior to training EX did not exhibit MAIT-cell mobilization/egress, however, both improved after training. (4) Conclusions: Reduced MAIT-cell frequency and ability to mobilize/egress were potentially partially rescued in EX after 12 weeks of exercise training; however, further research is needed to elucidate age or obesity-induced attenuations in MAIT-cells.

Metabolic syndrome and hidradenitis suppurativa: epidemiological, molecular, and therapeutic aspects

Hidradenitis suppurativa (HS) is a chronic, suppurative condition of the pilosebaceous unit. Patients suffering from HS demonstrate a molecular profile in keeping with a state of systemic inflammation and are often found to fit the criteria for a diagnosis of metabolic syndrome (MetS). In this paper, we review the literature with regards to established data on the prevalence of MetS in HS patients and revise the odds ratio of comorbid disease. Furthermore, we attempt to draw parallels between inflammatory pathways in HS and MetS and evaluate how convergences may explain the risk of comorbid disease, necessitating the need for multidisciplinary care.

Overweight and prognosis in triple-negative breast cancer patients: a systematic review and meta-analysis

We conducted a systematic review and meta-analysis investigating the association between overweight and outcome in triple-negative breast cancer (TNBC) patients. We searched PubMed and Embase using variations of the search terms triple-negative breast cancer (population), overweight and/or obesity (exposure), and prognosis (outcome). Based on the World Health Organization guidelines for defining overweight, we included longitudinal observational studies, which utilized survival statistics with hazard ratios (HRs) in our analysis. The included studies measured body mass index at the time of diagnosis of TNBC and reported disease-free survival and/or overall survival. Study quality was assessed with the Newcastle-Ottawa Scale and study data were extracted using the Meta-analysis of Observational Studies in Epidemiology (MOOSE) checklist, independently by two authors. Random-effects models were used to combine the effect sizes (HRs), and the results were evaluated and adjusted for possible publication bias. Thirteen studies of 8,944 TNBC patients were included. The meta-analysis showed that overweight was associated with both shorter disease-free survival (HR = 1.26; 95%CI: 1.09–1.46) and shorter overall survival (HR = 1.29; 95%CI: 1.11c1.51) compared to normal-weight. Additionally, our Bayesian meta-analyses suggest that overweight individuals are 7.4 and 9.9 times more likely to have shorter disease-free survival and overall survival, respectively. In conclusion, the available data suggest that overweight is associated with shorter disease-free and overall survival among TNBC patients. The results should be interpreted with caution due to possible publication bias.

Immunomodulatory Properties of Polyphenol-Rich Sugarcane Extract on Human Monocytes

As inflammatory lifestyle factors become more prevalent and as the population ages, the management of inflammation will become increasingly relevant. Plant polyphenols are powerful antioxidants that are known to have beneficial effects in a number of diseases with an inflammatory or oxidative component, such as malignancy, cardiovascular disease and arthritis. Polyphenol-rich sugarcane extract (PRSE) is a novel preparation with high concentrations of polyphenolic antioxidants, with some evidence to show benefits in health, but there is limited research investigating its effects on immunomodulation. This study determined the effects of PRSE on human monocyte cells in vitro. We show that PRSE has an immunomodulatory effect in U937 human monocyte cells, altering the expression of cellular surface markers, with an increased expression of CD16 and CD11b, as well as small changes in CD40, CD80, CD80, CD206 and MHCI. It also modulates the profile of secreted cytokines, increasing IL-1β, TNFα, IL-6, IL-8, IL-4 and IL-10. These changes are consistent with the advanced differentiation of the monocyte, as well as the switch from the M1 to M2 phenotype in macrophages. We also demonstrate that this effect is likely to be independent of the NF-κB signalling pathway, suggesting that other mechanisms drive this effect. PRSE exerts an immunomodulatory effect on U937 monocytes in vitro, potentially facilitating the conversion from inflammation to healing. Future studies should identify specific mechanisms underlying the changes and evaluate their effectiveness in animal models of disease.

Effects of Morbid Obesity and Metabolic Syndrome on the Composition of Circulating Immune Subsets

Morbid obesity is characterized by chronic, low-grade inflammation, which is associated with ‘inflamm-aging’. The presence of metabolic syndrome (MetS) might accelerate this phenomenon of metaflammation. In this study, we assessed the effects of morbid obesity and MetS on the composition of a broad spectrum of immune cells present within the circulation. A total of 117 morbidly obese patients (MOP) without MetS (MetS-), 127 MOP with MetS (MetS+) and 55 lean controls (LC) were included in this study. Absolute numbers of T cell, B cell, NK cell and monocyte subsets were assessed within peripheral blood using flow cytometry. Both absolute cell numbers and proportion of cells were evaluated correcting for covariates age, body mass index and cytomegalovirus serostatus. Although the absolute number of circulating CD4+ T cells was increased in the MetS+ group, the CD4+ T cell composition was not influenced by MetS. The CD8+ T cell and B cell compartment contained more differentiated cells in the MOP, but was not affected by MetS. Even though the absolute numbers of NK cells and monocytes were increased in the MOP as compared to LC, there was no difference in proportions of NK and monocyte subsets between the three study groups. In conclusion, although absolute numbers of CD4+ and CD8+ T cells, B cells, NK cells and monocytes are increased in MOP, obesity-induced effects of the composition of the immune system are confined to a more differentiated phenotype of CD8+ T cells and B cells. These results were not affected by MetS.

Dermal white adipose tissue: Much more than a metabolic, lipid-storage organ?

The role of dermal white adipose tissue (dWAT) has emerged in the biomedical science as an ancillary fat district in the derma without a defined and distinct function respect to the subcutaneous adipose tissue (sWAT). Despite some evidence describing dWAT as an immune-competent compartment, particularly engaged in wound repair, very few reports dealing with dWAT has elucidated its major modulatory role within the skin biology. Whereas an increasing bulk of evidence allows researcher to describe the main activity of sWAT, in humans dWAT is not properly a separated fat compartment and therefore scarcely considered in the scientific debate. Due to its strategic position between epidermis and sWAT, dermal fat might play a much more intriguing role than expected. This review tries to shed light on this issue, by expanding the debate about a possible role of dWAT in skin physiology.

Contribution of Adipose Tissue to the Chronic Immune Activation and Inflammation Associated With HIV Infection and Its Treatment

White adipose tissue (AT) contributes significantly to inflammation – especially in the context of obesity. Several of AT’s intrinsic features favor its key role in local and systemic inflammation: (i) large distribution throughout the body, (ii) major endocrine activity, and (iii) presence of metabolic and immune cells in close proximity. In obesity, the concomitant pro-inflammatory signals produced by immune cells, adipocytes and adipose stem cells help to drive local inflammation in a vicious circle. Although the secretion of adipokines by AT is a prime contributor to systemic inflammation, the lipotoxicity associated with AT dysfunction might also be involved and could affect distant organs. In HIV-infected patients, the AT is targeted by both HIV infection and antiretroviral therapy (ART). During the primary phase of infection, the virus targets AT directly (by infecting AT CD4 T cells) and indirectly (via viral protein release, inflammatory signals, and gut disruption). The initiation of ART drastically changes the picture: ART reduces viral load, restores (at least partially) the CD4 T cell count, and dampens inflammatory processes on the whole-body level but also within the AT. However, ART induces AT dysfunction and metabolic side effects, which are highly dependent on the individual molecules and the combination used. First generation thymidine reverse transcriptase inhibitors predominantly target mitochondrial DNA and induce oxidative stress and adipocyte death. Protease inhibitors predominantly affect metabolic pathways (affecting adipogenesis and adipocyte homeostasis) resulting in insulin resistance. Recently marketed integrase strand transfer inhibitors induce both adipocyte adipogenesis, hypertrophy and fibrosis. It is challenging to distinguish between the respective effects of viral persistence, persistent immune defects and ART toxicity on the inflammatory profile present in ART-controlled HIV-infected patients. The host metabolic status, the size of the pre-established viral reservoir, the quality of the immune restoration, and the natural ageing with associated comorbidities may mitigate and/or reinforce the contribution of antiretrovirals (ARVs) toxicity to the development of low-grade inflammation in HIV-infected patients. Protecting AT functions appears highly relevant in ART-controlled HIV-infected patients. It requires lifestyle habits improvement in the absence of effective anti-inflammatory treatment. Besides, reducing ART toxicities remains a crucial therapeutic goal.

Association of food quality index with subclinical inflammation in middle-aged obese men

BACKGROUND: High visceral fat storage unbalance secretion inflammatory peptides, however diet plays an important role-protecting metabolism against chronic diseases inherent to this condition. OBJECTIVE: To assess obese diet quality and find association with inflammatory biomarkers. METHODS: aMED, a Food Quality Index, classified the inflammatory power of 26 obese men’s diet (aged: 48.1±5.1; BMI: 31.1±2.45). Pearson correlation coefficient associated diet quality in tertiles (1st as low, 2nd as average and 3 rd as high quality diet) with inflammatory variables (cytokines and waist circumference). RESULTS: The intake of anti-inflammatory food groups was significantly higher among tertiles (3rd > 2nd > 1st; P < 0.001). Adiponectin was lower in the 2nd tertile than in the 1st (P < 0.05). Whole cereal presented a positive correlation with TNF-alpha (p = 0.049), and a negative correlation with IL–15 (p = 0.002). Fish presented a positive correlation with IL–10 (p = 0.024), Resistin (p = 0.039) and PGE–2 (p = 0.001). These findings pointed to pro and anti-inflammatory responses. CONCLUSIONS: The method may need adjustments when used to assess obese food intake, since they don’t usually meet the daily-recommended intake. Other lifestyles variables should be considered, which may affect the inflammatory status.

Effect of Calorie Restriction and Exercise on Type 2 Diabetes

Type-2 diabetes (T2D) is a chronic condition, generally regarded as an irreversible, that is among the top 10 causes of death globally. The hallmark of T2D is hyperglycemia, which results from disturbances in insulin sensitivity, insulin secretion, β-cell dysfunction and insulin resistance. Several clinical and lifestyle factors are involved in the progression of T2D, such as obesity and physical inactivity. A high-calorie diet is the main contributor to the development of obesity, which results in T2D, as obesity or increased intra-abdominal adipose tissue is related to insulin resistance. Technological advances have contributed to individuals having a more sedentary lifestyle, leading to obesity and T2D. T2D can be treated with lifestyle interventions, such as diet and exercise. Herein, we highlight the positive impact of a very low-calorie diet (VLCD) and lifestyle modalities in the treatment and prevention of T2D. An inclusion of VLCD 400-800 kcal/day for 8 weeks and ≥ 150 minutes exercise 5 times a week as lifestyle interventions can decrease glucose levels to normal, reduce HbA1c and improve insulin resistance and sensitivity. Therefore, a potential mechanism in maintaining glucose homeostasis and remission of T2D by VLCD and exercise reduces body weight.

Visfatin Regulates Inflammatory Mediators in Mouse Intestinal Mucosa Through Toll-Like Receptors Signaling Under Lipopolysaccharide Stress

Visfatin is a multifunctional protein involved in inflammatory immune stress. The aim of current study was to explore the role of visfatin in lipopolysaccharide (LPS)-induced intestinal mucosal inflammation and to confirm its cellular effect in inflammatory immune response through silencing of Toll-like receptors (TLRs). We divided Kunming mice into three groups: Saline group, LPS group, and LPS + visfatin group and performed hematoxylin and eosin staining, immunohistochemistry, quantitative polymerase chain reaction, Western blot, enzyme linked immunosorbent assay and RNA-seq analysis. Pretreatment of visfatin improves LPS-stimulated reduction of tight junction protein 1 (ZO-1) and secretory immunoglobulin A, inhibits overexpression of Claudin-1 and vascular endothelial growth factor, and reduces intestinal mucosal damage and inflammation. RNA-seq analysis of cellular transcriptomes indicated that visfatin is involved in down-regulation of mRNA level of TLR4 as well as attenuation of protein levels of TLR8 and nucleotide-binding oligomerization domain-containing protein 2, revealing that visfatin could reduce intestinal mucosal inflammation through TLR signaling pathway in mice ileum. In RAW264.7 cells, the genes silencing of Toll/IL-1R family, such as TLR4, TLR2, and IL-1R1, was accompanied by decreased expressions of inflammatory factors (TNF-α, IL-1β, IL-6 and MCP-1) along with lower cellular visfatin levels. Hence, visfatin maintains the intestinal mucosal barrier structure and attenuates the intestinal mucosal inflammation through the TLR signaling pathway. Likewise, the Toll/IL-1R family regulates the release of visfatin, which can participate in the inflammatory reaction through the regulation of inflammatory factors.

Use of Infrared Thermography to Estimate Brown Fat Activation After a Cooling Protocol in Patients with Severe Obesity That Underwent Bariatric Surgery

BACKGROUND

In contrast to the energy-storing role of white adipose tissue (WAT), brown adipose tissue (BAT) acts as the main site of non-shivering thermogenesis in mammals and has been reported to play a role in protection against obesity and associated metabolic alterations in rodents. Infrared thermography (IRT) has been proposed as a novel non-invasive, safe, and quick method to estimate BAT thermogenic activation in humans. The aim of this study is to determine whether the IRT could be a potential new tool to estimate BAT thermogenic activation in patients with severe obesity in response to bariatric surgery.

METHODS

Supraclavicular BAT thermogenic activation was evaluated using IRT in a cohort of 31 patients (50 ± 10 years old, BMI = 44.5 ± 7.8; 15 undergoing laparoscopy sleeve gastrectomy and 16 Roux-en-Y gastric bypass) at baseline and 6 months after a bariatric surgery. Clinical parameters were determined at these same time points.

RESULTS

Supraclavicular BAT-related activity was detected in our patients by IRT after a cooling stimulus. The BAT thermogenic activation was higher at 6 months after laparoscopy sleeve gastrectomy (0.06 ± 0.1 vs 0.32 ± 0.1), while patients undergoing to a roux-en-Y gastric bypass did not change their thermogenic response using the same cooling stimulus (0.09 ± 0.1 vs 0.08 ± 0.1).

CONCLUSIONS

Our study postulates the IRT as a potential tool to evaluate BAT thermogenic activation in patients with obesity before and after a bariatric surgery. Further studies are needed to evaluate differences between LSG technique and RYGB on BAT activation.

Cellular mechanisms linking cancers to obesity

Obesity is epidemiologically linked to 13 forms of cancer. The local and systemic obese environment is complex and likely affect tumors through multiple avenues. This includes modulation of cancer cell phenotypes and the composition of the tumor microenvironment. A molecular understanding of how obesity links to cancer holds promise for identifying candidate genes for targeted therapy for obese cancer patient. Herein, we review both the cell-autonomous and non-cell-autonomous mechanisms linking obesity and cancer as well as provide an overview of the mouse model systems applied to study this.

Does exercise attenuate age- and disease-associated dysfunction in unconventional T cells? Shining a light on overlooked cells in exercise immunology

Unconventional T Cells (UTCs) are a unique population of immune cells that links innate and adaptive immunity. Following activation, UTCs contribute to a host of immunological activities, rapidly responding to microbial and viral infections and playing key roles in tumor suppression. Aging and chronic disease both have been shown to adversely affect UTC numbers and function, with increased inflammation, change in body composition, and physical inactivity potentially contributing to the decline. One possibility to augment circulating UTCs is through increased physical activity. Acute exercise is a potent stimulus leading to the mobilization of immune cells while the benefits of exercise training may include anti-inflammatory effects, reductions in fat mass, and improved fitness. We provide an overview of age-related changes in UTCs, along with chronic diseases that are associated with altered UTC number and function. We summarize how UTCs respond to acute exercise and exercise training and discuss potential mechanisms that may lead to improved frequency and function.

High-dimensional immunotyping of tumors grown in obese and non-obese mice

Obesity is a disease characterized by chronic low-grade systemic inflammation and has been causally linked to the development of 13 cancer types. Several studies have been undertaken to determine whether tumors evolving in obese environments adapt differential interactions with immune cells and whether this can be connected to disease outcome. Most of these studies have been limited to single-cell lines and tumor models and analysis of limited immune cell populations. Given the multicellular complexity of the immune system and its dysregulation in obesity, we applied high-dimensional suspension mass cytometry to investigate how obesity affects tumor immunity. We used a 36-marker immune-focused mass cytometry panel to interrogate the immune landscape of orthotopic syngeneic mouse models of pancreatic and breast cancer. Unanchored batch correction was implemented to enable simultaneous analysis of tumor cohorts to uncover the immunotypes of each cancer model and reveal remarkably model-specific immune regulation. In the E0771 breast cancer model, we demonstrate an important link to obesity with an increase in two T-cell-suppressive cell types and a decrease in CD8 T cells.

Anti-cancer effects of polyphenol-rich sugarcane extract

Plant polyphenols have an array of health benefits primarily thought to be related to their high content of anti-oxidants. These are commonly undervalued and knowledge of their biological properties have grown exponentially in the last decade. Polyphenol-rich sugarcane extract (PRSE), a natural extract from sugar cane, is marketed as high in anti-oxidants and polyphenols, but its anti-cancer activity has not been reported previously. We show that, PRSE exerts anti-cancer properties on a range of cancer cells including human (LIM2045) and mouse (MC38, CT26) colon cancer cells lines; human lung cancer (A549), human ovarian cancer (SKOV-3), pro-monocytic human leukemia (U937) and to mouse melanoma (B16) cell lines; whereas no effects were noted on human breast (ZR-75-1) and human colon (HT29) cancer cell lines, as well as to human normal colon epithelial cell line (T4056). Anti-proliferative effects were shown to be mediated via alteration in cytokines, VEGF-1 and NF-κB expression.

Levels of cardiorespiratory fitness in men exerts strong impact on lymphocyte function after mitogen stimulation

Relationship between lymphocyte function and cardiorespiratory fitness (CRF) is well-documented at rest; however, upon mitogen stimulation the proliferation and cytokine production alters, but knowledge is incipient about lymphocyte responses after mitogen stimulus according to CRF. So, the purpose of the present study was to analyze the lymphocyte function according to the physical fitness status of healthy young men. The study is divided in two experiments being the first analyzing the lymphocyte phenotypes profile and the inflammatory responses, according to CRF, in lymphocyte cell cultures treated for 48 h with concanavalin A (ConA). The second experiment analyzed the proliferation, reactive oxygen species production, viability, and mitochondrial polarization state in lymphocytes treated with ConA in different concentrations, considering the CRF levels. The results showed a difference in the percentage of total lymphocytes expression between groups (P = 0.011) observing a lower lymphocytes T expression in the group with high maximal oxygen consumption (V̇o_2max) when compared with the moderate V̇o_2max group. When treated with ConA, the lymphocytes of the low V̇o_2max group released higher TNF-α concentration (P = 0.032), reflecting an elevated TNF-α/IL-10 ratio (P = 0.055), parallel with lower IL-6 production (P = 0.027), mainly when compared with the moderate V̇o_2max group. In addition, there is a positive relationship between V̇o_2max and IL-6 production (r = 0.507; P = 0.016), whereas the percentage of total lymphocytes (LyT%) shows a negative trend with V̇o_2max (r = -0.497; P = 0.060). Also, individuals with lower V̇o_2max showed reduced absolute and relative ROS production, lower cell proliferation, and higher mitochondrial membrane depolarization. In conclusion, cardiorespiratory fitness degree exerts a strong impact on lymphocyte function after mitogen stimulation.NEW & NOTEWORTHY The innovation of the research is to elucidate the impact of different physical fitness status on metabolism, cell proliferation, and lymphocyte activity and, consequently, on the specific inflammatory response against a mitogen.

Sarcopenia and Cognitive Function: Role of Myokines in Muscle Brain Cross-Talk

Sarcopenia is a geriatric syndrome characterized by the progressive degeneration of muscle mass and function, and it is associated with severe complications, which are falls, functional decline, frailty, and mortality. Sarcopenia is associated with cognitive impairment, defined as a decline in one or more cognitive domains as language, memory, reasoning, social cognition, planning, making decisions, and solving problems. Although the exact mechanism relating to sarcopenia and cognitive function has not yet been defined, several studies have shown that skeletal muscle produces and secrete molecules, called myokines, that regulate brain functions, including mood, learning, locomotor activity, and neuronal injury protection, showing the existence of muscle-brain cross-talk. Moreover, studies conducted on physical exercise supported the existence of muscle-brain cross-talk, showing how physical activity, changing myokines' circulating levels, exerts beneficial effects on the brain. The review mainly focuses on describing the role of myokines on brain function and their involvement in cognitive impairment in sarcopenia.

Association of Adipose Tissue and Adipokines with Development of Obesity-Induced Liver Cancer

Obesity is rapidly dispersing all around the world and is closely associated with a high risk of metabolic diseases such as insulin resistance, dyslipidemia, and nonalcoholic fatty liver disease (NAFLD), leading to carcinogenesis, especially hepatocellular carcinoma (HCC). It results from an imbalance between food intake and energy expenditure, leading to an excessive accumulation of adipose tissue (AT). Adipocytes play a substantial role in the tumor microenvironment through the secretion of several adipokines, affecting cancer progression, metastasis, and chemoresistance via diverse signaling pathways. AT is considered an endocrine organ owing to its ability to secrete adipokines, such as leptin, adiponectin, resistin, and a plethora of inflammatory cytokines, which modulate insulin sensitivity and trigger chronic low-grade inflammation in different organs. Even though the precise mechanisms are still unfolding, it is now established that the dysregulated secretion of adipokines by AT contributes to the development of obesity-related metabolic disorders. This review focuses on several obesity-associated adipokines and their impact on obesity-related metabolic diseases, subsequent metabolic complications, and progression to HCC, as well as their role as potential therapeutic targets. The field is rapidly developing, and further research is still required to fully understand the underlying mechanisms for the metabolic actions of adipokines and their role in obesity-associated HCC.

Shades of white: new insights into tissue-resident leukocyte heterogeneity

Populations of white blood cells (leukocytes) have been found in tissues and organs across the body, in states of both health and disease. The role leukocytes play within these tissues is often highly contested. For many leukocytes, there are studies outlining pro-inflammatory destructive functions, while other studies provide clear evidence of anti-inflammatory homeostatic activities of leukocytes within the same tissue. We discuss how this functional dissonance can be explained by leukocyte heterogeneity. Although cell morphology and surface receptor profiles are excellent methods to segregate cell types, the true degree of leukocyte heterogeneity that exists can only be appreciated by studying the variable and dynamic gene expression profile. Unbiased single-cell RNA sequencing profiling of tissue-resident leukocytes is transforming the way we understand leukocytes across health and disease. Recent investigations into adipose tissue-resident leukocytes have revealed unprecedented levels of heterogeneity among populations of macrophages. We use this example to pose emerging questions regarding tissue-resident leukocytes and review what is currently known (and unknown) about the diversity of tissue-resident leukocytes within different organs.

Altered distribution and enhanced osteoclastogenesis of mucosal-associated invariant T cells in gouty arthritis

OBJECTIVE

This study was designed to investigate the role of mucosal-associated invariant T (MAIT) cells in gouty arthritis (GA) and their effects on osteoclastogenesis.

METHODS

Patients with GA (n = 61), subjects with hyperuricaemia (n = 11) and healthy controls (n = 30) were enrolled in this study. MAIT cells, cytokines, CD69, programmed death-1 (PD-1) and lymphocyte-activation gene 3 (LAG-3) levels were measured by flow cytometry. In vitro osteoclastogenesis experiments were performed using peripheral blood mononuclear cells in the presence of M-CSF and RANK ligand.

RESULTS

Circulating MAIT cell levels were significantly reduced in GA patients. However, their capacities for IFN-γ, IL-17 and TNF-α production were preserved. Expression levels of CD69, PD-1 and LAG-3 in MAIT cells were found to be elevated in GA patients. In particular, CD69 expression in circulating MAIT cells was increased by stimulation with MSU crystals, suggesting that deposition of MSU crystals might contribute to MAIT cell activation. Interestingly, MAIT cells were found to be accumulated in synovial fluid and infiltrated into gouty tophus tissues within joints. Furthermore, activated MAIT cells secreted pro-resorptive cytokines (i.e. IL-6, IL-17 and TNF-α) and facilitated osteoclastogenesis.

CONCLUSION

This study demonstrates that circulating MAIT cells are activated and numerically deficient in GA patients. In addition, MAIT cells have the potential to migrate to inflamed tissues and induce osteoclastogenesis. These findings provide an important role of MAIT cells in the pathogenesis of inflammation and bone destruction in GA patients.