Association between serum and adipose tissue resistin with dysglycemia in South Asian women

White adipocyte dysfunction and obesity-associated pathologies in humans

The prevalence of obesity and associated chronic diseases continues to increase worldwide, negatively impacting on societies and economies. Whereas the association between excess body weight and increased risk for developing a multitude of diseases is well established, the initiating mechanisms by which weight gain impairs our metabolic health remain surprisingly contested. In order to better address the myriad of disease states associated with obesity, it is essential to understand adipose tissue dysfunction and develop strategies for reinforcing adipocyte health. In this Review we outline the diverse physiological functions and pathological roles of human white adipocytes, examining our current knowledge of why white adipocytes are vital for systemic metabolic control, yet poorly adapted to our current obesogenic environment.

Leuconostoc Citreum Inhibits Adipogenesis and Lipogenesis by Inhibiting p38 MAPK/Erk 44/42 and Stimulating AMPKα Signaling Pathways

Probiotics provide a range of health benefits. Several studies have shown that using probiotics in obesity treatment can reduce bodyweight. However, such treatments are still restricted. Leuconostoc citreum, an epiphytic bacterium, is widely used in a variety of biological applications. However, few studies have investigated the role of Leuconostoc spp. in adipocyte differentiation and its molecular mechanisms. Therefore, the objective of this study was to determine the effects of cell-free metabolites of L. citreum (LSC) on adipogenesis, lipogenesis, and lipolysis in 3T3-L1 adipocytes. The results showed that LSC treatment reduced the accumulation of lipid droplets and expression levels of CCAAT/ enhancer-binding protein-α & β (C/EBP-α & β), peroxisome proliferator-activated receptor-γ (PPAR-γ), serum regulatory binding protein-1c (SREBP-1c), adipocyte fatty acid binding protein (aP2), fatty acid synthase (FAS), acetyl CoA carboxylase (ACC), resistin, pp38MAPK, and pErk 44/42. However, compared to control cells, adiponectin, an insulin sensitizer, was elevated in adipocytes treated with LSC. In addition, LSC treatment increased lipolysis by increasing pAMPK-α and suppressing FAS, ACC, and PPAR-γ expression, similarly to the effects of AICAR, an AMPK agonist. In conclusion, L. citreum is a novel probiotic strain that can be used to treat obesity and its associated metabolic disorders.

Analysis of different adipose depot gene expression in cachectic patients with gastric cancer

Purpose

This study aimed to identify the differentially expressed genes (DEGs) that contributed to the different amount of fat loss between subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) among cachectic patients.

Methods

RNA sequencing was performed and bioinformatic tools were utilized to analyze the biological functions and construct regulation networks of DEGs. We presumed that iroquois homeobox 1 (IRX1) to be a hub gene and analyzed its clinical significance. Mouse model of cancer cachexia was established and differences between SAT and VAT were compared. The function of IRX1 on lipid metabolism was clarified by Oil Red O staining, qRT-PCR, and Western blotting in adipocytes.

Results

A total of 455 DEGs were screened between SAT and VAT in cachectic patients. Several hub genes were selected and IRX1 was presumed to contribute to the pathological difference between SAT and VAT in cancer cachexia. Patients with higher expression of IRX1 in SAT than VAT revealed significantly higher weight loss, IL-6 and TNF-α, as well as lower BMI, SAT, and VAT area. IRX1 expression in SAT was negatively correlated with SAT area. In cachectic mice, the expression of IRX1 in SAT was significantly higher than that in VAT. The inhibition effect on adipogenesis exerted by IRX1 was also proved in vitro.

Conclusion

These data supported that DEGs contribute to the different degrees of fat loss among adipose depots in cachectic patients. IRX1 in SAT promoted fat loss by inhibiting adipocyte differentiation and adipogenesis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12986-022-00708-x.

DPHB, a diarylheptane from Alpinia officinarum Hance, ameliorates insulin resistance: A network pharmacology and in vitro study

(4E)-7-(4-Hydroxy-3-methoxyphenyl)-1-phenylhept-4-en-3-one (DPHB) derived from A. officinarum Hance has been reported to exert anti-inflammatory and anti-insulin resistance (IR) effects. We explored the molecular mechanism of DPHB ameliorating IR through network pharmacological prediction and in vitro analysis. The PI3K/AKT and TNF signaling pathways are the core pathways for DPHB to exert anti-IR, and the key proteins of this pathway were confirmed by molecular docking. In the IR-3T3-L1 adipocyte model, DPHB significantly promoted glucose uptake and the glucose transporter type 4 (GLUT4) translocation. In addition, DPHB significantly improved lipid accumulation, triglyceride content, and the mRNA expression of key adipokines [such as peroxisome proliferator-activated receptors-gamma (PPARγ), CCAAT enhancer-binding protein alpha (C/EBPα), and sterol regulatory element-binding protein-1 (SREBP-1)]. DPHB inhibited the protein expression of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and phosphorylated nuclear factor-κB (NF-kB), as well as promoted the expression of phosphatidylinositol 3-kinase (PI3K), protein kinase B (AKT), phosphorylated PI3K, and phosphorylated AKT. More interestingly, validation of the PI3K inhibitor LY294002 revealed that these changes were dependent on the activation of PI3K. Our cumulative findings thereby validate the potential of DPHB to alleviate and treat IR and the related diseases by regulating the PI3K/AKT and TNF-α signaling pathways.

The Association between Serum Resistin Level, Resistin (-420C/G) Single Nucleotide Variant, and Markers of Endothelial Dysfunction, including Salt Taste Preference in Hypertensive Patients

Background: Resistin action links to conditions such as diabetes, obesity, but its role in hypertension is less well understood. This study aimed to estimate the relationship between resistin (−420G/C) single nucleotide variant (SNV) and markers associated with endothelial dysfunction in hypertension. Methods: The study enrolled 162 hypertensive patients (HT) and 165 non-hypertensive (NHT) patients. Resistin serum concentration was estimated with immuoenzymatic assay. Anthropometric measurements, blood pressure and arterial stiffness index (SI), uric acid (UA) serum concentration, and salty taste preference of normal (NS) or high (HS) were assessed in the study. Genotyping was achieved by polymerase chain reaction-restriction fragment length polymorphism. Results: Resistin concentration and SI do not differ significantly between HT and NHT individuals; UA significantly increased in HT subjects. Resistin, UA, and SI did not differ among particular resistin genotypes in HT, NHT, NS, or HS groups. GG and CG genotypes were more frequent (OR 1.57 (95% CI; 1.01–2.43); p = 0.04) in hypertensive individuals than the NHT group, but less frequent (OR 0.58 (95% CI; 0.37–0.91); p = 0.01) in HS patients compared to NS individuals. Concerning HT patients with different salt preferences, GG + CG genotypes were less frequent (OR 0.50 (95% CI; 0.26–0.97); p = 0.04) in the HS group than in NS individuals. HT carriers of GG and CG genotype have significantly increased UA concentrations compared to the respective NHT subjects. HS individuals carrying GG and CG genotypes have higher SI values than the NS group. Allele G of SNV (−420G/C) adjusted for age, BMI, serum resistin, UA concentration, salt taste preference, SI, and HR values increased the risk of developing hypertensive phenotype 1.8 fold. Conclusions: Resistin SNV (−420G/C) is related to several markers associated with endothelial dysfunction, including salt taste preference in hypertensive patients.

Age and Sex: Impact on adipose tissue metabolism and inflammation

Age associated chronic inflammation is a major contributor to diseases with advancing age. Adipose tissue function is at the nexus of processes contributing to age-related metabolic disease and mediating longevity. Hormonal fluctuations in aging potentially regulate age-associated visceral adiposity and metabolic dysfunction. Visceral adiposity in aging is linked to aberrant adipogenesis, insulin resistance, lipotoxicity and altered adipokine secretion. Age-related inflammatory phenomena depict sex differences in macrophage polarization, changes in T and B cell numbers, and types of dendritic cells. Sex differences are also observed in adipose tissue remodeling and cellular senescence suggesting a role for sex steroid hormones in the regulation of the adipose tissue microenvironment. It is crucial to investigate sex differences in aging clinical outcomes to identify and better understand physiology in at-risk individuals. Early interventions aimed at targets involved in adipose tissue adipogenesis, remodeling and inflammation in aging could facilitate a profound impact on health span and overcome age-related functional decline.

Biochemical and immunological changes in obesity

Obesity is a syndemia that promotes high expenditures for public health, and is defined by the excess of adipose tissue that is classified according to its function and anatomical distribution. In obese people, this tissue generates oxidative stress associated with a chronic inflammatory response, in which there is an imbalance in relation to the release of hormones and adipokines that cause loss of body homeostasis and predisposition to the development of some comorbidities. The purpose of this review is to summarize the main events that occur during the onset and progression of obesity with a special focus on biochemical and immunological changes. Hypertrophied and hyperplasia adipocytes have biomarkers and release adipokines capable of regulating pathways and expressing genes that culminate in the development of metabolic changes, such as changes in energy balance and intestinal microbiota, and the development of some comorbidities, diabetes mellitus, dyslipidemias, arterial hypertension, liver disease, cancer, allergies, osteoporosis, sarcopenia and obstructive sleep apnea. Thus, it is necessary to treat and/or prevent pathology, using traditional methods based on healthy eating, and regular physical and leisure activities.

Omega-3 Fatty Acids and Adipose Tissue: Inflammation and Browning

White adipose tissue (WAT) and brown adipose tissue (BAT) are involved in whole-body energy homeostasis and metabolic regulation. Changes to mass and function of these tissues impact glucose homeostasis and whole-body energy balance during development of obesity, weight loss, and subsequent weight regain. Omega-3 polyunsaturated fatty acids (ω-3 PUFAs), which have known hypotriglyceridemic and cardioprotective effects, can also impact WAT and BAT function. In rodent models, these fatty acids alleviate obesity-associated WAT inflammation, improve energy metabolism, and increase thermogenic markers in BAT. Emerging evidence suggests that ω-3 PUFAs can also modulate gut microbiota impacting WAT function and adiposity. This review discusses molecular mechanisms, implications of these findings, translation to humans, and future work, especially with reference to the potential of these fatty acids in weight loss maintenance.

Exposure to Low Doses of Dechlorane Plus Promotes Adipose Tissue Dysfunction and Glucose Intolerance in Male Mice

The prevalence of type 2 diabetes (T2D) continues to increase worldwide. It is well established that genetic susceptibility, obesity, overnutrition and a sedentary life style are risk factors for the development of T2D. However, more recently, studies have also proposed links between exposure to endocrine-disrupting chemicals (EDCs) and altered glucose metabolism. Human exposure to environmental pollutants that are suspected to have endocrine disruptor activity is ubiquitous. One such chemical is Dechlorane Plus (DP), a flame retardant, that is now detected in humans and the environment. Here we show that exposure of mice to low, environmentally relevant doses of DP promoted glucose intolerance in mice fed a high-fat diet independent of weight gain. Furthermore, DP had pronounced effects on the adipose tissue, where it induced the development of hypertrophied white adipose tissue (WAT), and increased serum levels of resistin, leptin, and plasminogen activator inhibitor-1. In addition, DP exposure induced "whitening" of brown adipose tissue (BAT), and reduced BAT uncoupling protein 1 expression. Importantly, some of these effects occurred even when the mice were fed a regular, low-fat, diet. Finally, WAT adipogenic markers were reduced with DP treatment in the WAT. We also show that DP directly inhibited insulin signaling in murine adipocytes and human primary subcutaneous adipocytes in vitro. Taken together, our results show that the exposure to low and environmentally relevant levels of DP may contribute to the development of T2D.

Lipoteichoic acid from the cell wall of a heat killed Lactobacillus paracasei D3-5 ameliorates aging-related leaky gut, inflammation and improves physical and cognitive functions: from C. elegans to mice

Increased inflammation associated with leaky gut is a major risk factor for morbidity and mortality in older adults; however, successful preventive and therapeutic strategies against these conditions are not available. In this study, we demonstrate that a human-origin Lactobacillus paracasei D3-5 strain (D3-5), even in the non-viable form, extends life span of Caenorhabditis elegans. In addition, feeding of heat-killed D3-5 to old mice (> 79 weeks) prevents high- fat diet-induced metabolic dysfunctions, decreases leaky gut and inflammation, and improves physical and cognitive functions. D3-5 feeding significantly increases mucin production, and proportionately, the abundance of mucin-degrading bacteria Akkermansia muciniphila also increases. Mechanistically, we show that the lipoteichoic acid (LTA), a cell wall component of D3-5, enhances mucin (Muc2) expression by modulating TLR-2/p38-MAPK/NF-kB pathway, which in turn reduces age-related leaky gut and inflammation. The findings indicate that the D3-5 and its LTA can prevent/treat age-related leaky gut and inflammation.