Obesity and Adipose Tissue Dysfunction: From Pediatrics to Adults

Three-Month Excessive Body Weight Loss < 37.7% as a Predictor of Mid-term Suboptimal Outcomes Postlaparoscopic Sleeve Gastrectomy: Risk Factors and the Impact of Neutrophil-to-Lymphocyte Ratio on Adipocyte Function

INTRODUCTION

This study aimed to evaluate the impact of achieving < 37.7% excess body-weight loss (EBWL) within 3 months of postlaparoscopic sleeve gastrectomy (LSG) on clinical outcomes and its correlation with adipocyte function.

METHODS

Patients (n = 176) who underwent LSG between January 2019 and January 2023 were included. Weight loss and status of health markers were monitored postoperatively. The cohort was stratified based on EBWL < 37.7% at 3 months or not. Variables including neutrophil-to-lymphocyte ratio (NLR), insulin resistance, and comorbidities were analyzed. Omental visceral and subcutaneous adipose tissue samples were used to analyze the differences in adipocyte function by western blot.

RESULTS

Patients with EBWL < 37.7% at 3 months post-LSG (suboptimal group) comprised less likelihood of achieving ≥ 50% EBWL than those who achieved ≥ 37.7% EBWL (optimal group) at 6 months (42.55% vs. 95.52% in optimal group, p < 0.001), 12 months (85.11% vs. 99.25% in optimal group, p < 0.001) and 24 months (77.14% vs. 94.74% in optimal group, p = 0.009) post-LSG. High BMI (OR = 1.222, 95% CI 1.138-1.312, p < 0.001), NLR ≥ 2.36 (OR = 2.915, 95% CI 1.257-6.670, p = 0.013), and female sex (OR = 3.243, 95% CI 1.306-8.051, p = 0.011) significantly predicted EBWL < 37.7% at 3 months post-LSG. Patients with NLR ≥ 2.36 had significantly lower adipose triglyceride lipase in omental fat (p = 0.025).

CONCLUSION

EBWL < 37.7% at 3 months post-LSG is a strong predictor of subsequent suboptimal weight loss. High BMI, NLR ≥ 2.36, and female sex are risk factors in predicting EBWL < 37.7% at 3 months post-LSG. These findings may offer a reference to apply adjuvant weight loss medications to patients who are predisposed to suboptimal outcomes.

A Cross-Sectional Analysis of Dietary Patterns in Healthy Adolescents: Energy Balance, Nutrient Intake, Body Mass, and Serum Marker Alterations

(1) Background: With shifts in daily dietary habits, concerns have arisen regarding potential impacts on metabolic health. This study sought to investigate the interplay between nutrient intake and its effects on the anthropometric and inflammatory profiles of young individuals. (2) Methods: Our approach examined the interrelation of caloric, macronutrient, and vitamin intakes with inflammatory markers, serum cholesterol, triglycerides, and other key metrics. The impact of these factors on body mass and inflammation was evaluated. (3) Results: This study found that while increased caloric intake corresponded to a rise in body fat mass, it did not significantly alter body weight, total protein, or fat profile. A dominant carbohydrate intake negatively correlated with vitamin B consumption. Interestingly, only vitamin K showcased a direct association with IL-6, while IL-8 remained unassociated with dietary intake and body mass metrics. (4) Conclusions: Dietary intake undeniably influences nutrient consumption and subsequently affects body mass metrics. Though an escalation in body fat mass was evident with increased food intake, the relationship between vitamins and inflammatory markers, based on macronutrient and caloric intake, remains inconclusive. The findings point to the potential regulatory roles of proteins and select vitamins in inflammation, emphasizing the need for deeper longitudinal studies to further validate these connections.

Nuclear and chromatin rearrangement associate to epigenome and gene expression changes in a model of in vitro adipogenesis and hypertrophy

Hypertrophy of adipocytes represents the main cause of obesity. We investigated in vitro the changes associated with adipocyte differentiation and hypertrophy focusing on the nuclear morphometry and chromatin epigenetic remodelling. The 3 T3-L1 pre-adipocytes were firstly differentiated into mature adipocytes, then cultured with long-chain fatty acids to induce hypertrophy. Confocal and super-resolution stimulation emission depletion (STED) microscopy combined with ELISA assays allowed us to explore nuclear architecture, chromatin distribution and epigenetic modifications. In each condition, we quantified the triglyceride accumulation, the mRNA expression of adipogenesis and dysfunction markers, the release of five pro-inflammatory cytokines. Confocal microscopy revealed larger volume and less elongated shape of the nuclei in both mature and hypertrophic cells respect to pre-adipocytes, and a trend toward reduced chromatin compaction. Compared to mature adipocytes, the hypertrophic phenotype showed larger triglyceride content, increased PPARγ expression reduced IL-1a release, and up-regulation of a pool of genes markers for adipose tissue dysfunction. Moreover, a remodelling of both epigenome and chromatin organization was observed in hypertrophic adipocytes, with an increase in the average fluorescence of H3K9 acetylated domains in parallel with the increase in KAT2A expression, and a global hypomethylation of DNA. These findings making light on the nuclear changes during adipocyte differentiation and hypertrophy might help the strategies for treating obesity and metabolic complications.

Time- and glucose-dependent differentiation of 3T3-L1 adipocytes mimics dysfunctional adiposity

The 3T3-L1 murine adipocyte cell line remains one of the most widely used models to study the mechanisms of obesity and related pathologies. Most studies investigate such mechanisms using mature adipocytes that have been chemically induced to differentiate for 7 days in media containing 25 mM glucose. However, the dysfunctional characteristics commonly observed in obesity including adipocyte hypertrophy, increased expression of inflammatory markers, enhanced production of reactive oxygen species (ROS), increased steroidogenic enzyme expression/activity and production of steroid hormones, are not necessarily mimicked in these cells. The aim of this study was to provide an inexpensive model which represents the well-known characteristics of obesity by manipulating the time of adipocyte differentiation and increasing the concentration of glucose in the cell media. Our results showed a glucose- and time-dependent increase in adipocyte hypertrophy, ROS production and gene expression of the pro-inflammatory cytokine interleukin-6 (IL-6), as well as a time-dependent increase in lipolysis and in the gene expression of the chemokine monocyte chemoattractant protein 1 (MCP1). We also showed that gene expression of the steroidogenic enzymes 11-beta-hydroxysteroid dehydrogenase type 1 (11βHSD1), 17βHSD type 7 and 12, as well as CYP19A1 (aromatase), were significantly higher in the hypertrophic model relative to the control adipocytes differentiated using the conventional method. The increase in 11βHSD1 and 17βHSD12 expression was consistent with the enhanced conversion of cortisone and androstenedione to cortisol and testosterone, respectively. As these characteristics reflect those commonly observed in obesity, hypertrophic 3T3-L1 adipocytes are an appropriate in vitro model to study mechanisms of adipocyte dysfunction in an era where the rise in obesity incidence is a global health concern, and where access to adipose tissue from obese patients are limited.

Vachellia farnesiana Pods or a Polyphenolic Extract Derived from Them Exert Immunomodulatory, Metabolic, Renoprotective, and Prebiotic Effects in Mice Fed a High-Fat Diet

Obesity causes systemic inflammation, hepatic and renal damage, as well as gut microbiota dysbiosis. Alternative vegetable sources rich in polyphenols are known to prevent or delay the progression of metabolic abnormalities during obesity. Vachellia farnesiana (VF) is a potent source of polyphenols with antioxidant and anti-inflammatory activities with potential anti-obesity effects. We performed an in vivo preventive or an interventional experimental study in mice and in vitro experiments with different cell types. In the preventive study, male C57BL/6 mice were fed with a Control diet, a high-fat diet, or a high-fat diet containing either 0.1% methyl gallate, 10% powdered VFP, or 0.5%, 1%, or 2% of a polyphenolic extract (PE) derived from VFP (Vachellia farnesiana pods) for 14 weeks. In the intervention study, two groups of mice were fed for 14 weeks with a high-fat diet and then one switched to a high-fat diet with 10% powdered VFP for ten additional weeks. In the in vitro studies, we evaluated the effect of a VFPE (Vachellia farnesiana polyphenolic extract) on glucose-stimulated insulin secretion in INS-1E cells or of naringenin or methyl gallate on mitochondrial activity in primary hepatocytes and C2C12 myotubes. VFP or a VFPE increased whole-body energy expenditure and mitochondrial activity in skeletal muscle; prevented insulin resistance, hepatic steatosis, and kidney damage; exerted immunomodulatory effects; and reshaped fecal gut microbiota composition in mice fed a high-fat diet. VFPE decreased insulin secretion in INS-1E cells, and its isolated compounds naringenin and methyl gallate increased mitochondrial activity in primary hepatocytes and C2C12 myotubes. In conclusion VFP or a VFPE prevented systemic inflammation, insulin resistance, and hepatic and renal damage in mice fed a high-fat diet associated with increased energy expenditure, improved mitochondrial function, and reduction in insulin secretion.

Subcutaneous Adipose Tissue Transcriptome Highlights Specific Expression Profiles in Severe Pediatric Obesity: A Pilot Study

The prevalence of pediatric obesity is rising rapidly worldwide, and "omic" approaches are helpful in investigating the molecular pathophysiology of obesity. This work aims to identify transcriptional differences in the subcutaneous adipose tissue (scAT) of children with overweight (OW), obesity (OB), or severe obesity (SV) compared with those of normal weight (NW). Periumbilical scAT biopsies were collected from 20 male children aged 1-12 years. The children were stratified into the following four groups according to their BMI z-scores: SV, OB, OW, and NW. scAT RNA-Seq analyses were performed, and a differential expression analysis was conducted using the DESeq2 R package. A pathways analysis was performed to gain biological insights into gene expression. Our data highlight the significant deregulation in both coding and non-coding transcripts in the SV group when compared with the NW, OW, and OB groups. A KEGG pathway analysis showed that coding transcripts were mainly involved in lipid metabolism. A GSEA analysis revealed the upregulation of lipid degradation and metabolism in SV vs. OB and SV vs. OW. Bioenergetic processes and the catabolism of branched-chain amino acids were upregulated in SV compared with OB, OW, and NW. In conclusion, we report for the first time that a significant transcriptional deregulation occurs in the periumbilical scAT of children with severe obesity compared with those of normal weight or those with overweight or mild obesity.

Recent Advances in the Knowledge of the Mechanisms of Leptin Physiology and Actions in Neurological and Metabolic Pathologies

Excess body weight is frequently associated with low-grade inflammation. Evidence indicates a relationship between obesity and cancer, as well as with other diseases, such as diabetes and non-alcoholic fatty liver disease, in which inflammation and the actions of various adipokines play a role in the pathological mechanisms involved in these disorders. Leptin is mainly produced by adipose tissue in proportion to fat stores, but it is also synthesized in other organs, where leptin receptors are expressed. This hormone performs numerous actions in the brain, mainly related to the control of energy homeostasis. It is also involved in neurogenesis and neuroprotection, and central leptin resistance is related to some neurological disorders, e.g., Parkinson's and Alzheimer's diseases. In peripheral tissues, leptin is implicated in the regulation of metabolism, as well as of bone density and muscle mass. All these actions can be affected by changes in leptin levels and the mechanisms associated with resistance to this hormone. This review will present recent advances in the molecular mechanisms of leptin action and their underlying roles in pathological situations, which may be of interest for revealing new approaches for the treatment of diseases where the actions of this adipokine might be compromised.

Bioactive dietary components-Anti-obesity effects related to energy metabolism and inflammation

Obesity is the result of the long-term energy imbalance between the excess calories consumed and the few calories expended. Reducing the intake of energy dense foods (fats, sugars), and strategies such as fasting and caloric restriction can promote body weight loss. Not only energy in terms of calories, but also the specific composition of the diet can affect the way the food is absorbed and how its energy is stored, used or dissipated. Recent research has shown that bioactive components of food, such as polyphenols and vitamins, can influence obesity and its pathologic complications such as insulin resistance, inflammation and metabolic syndrome. Individual micronutrients can influence lipid turnover but for long-term effects on weight stability, dietary patterns containing several micronutrients may be required. At the molecular level, these molecules modulate signaling and the expression of genes that are involved in the regulation of energy intake, lipid metabolism, adipogenesis into white, beige and brown adipose tissue, thermogenesis, lipotoxicity, adipo/cytokine synthesis, and inflammation. Higher concentrations of these molecules can be reached in the intestine, where they can modulate the composition and action of the microbiome. In this review, the molecular mechanisms by which bioactive compounds and vitamins modulate energy metabolism, inflammation and obesity are discussed.