Lipotoxicity, overnutrition and energy metabolism in aging

Role of fatty acids in the pathogenesis of ß-cell failure and Type-2 diabetes

Pancreatic ß-cells are glucose sensors in charge of regulated insulin delivery to the organism, achieving glucose homeostasis and overall energy storage. The latter function promotes obesity when nutrient intake chronically exceeds daily expenditure. In case of ß-cell failure, such weight gain may pave the way for the development of Type-2 diabetes. However, the causal link between excessive body fat mass and potential degradation of ß-cells remains largely unknown and debated. Over the last decades, intensive research has been conducted on the role of lipids in the pathogenesis of ß-cells, also referred to as lipotoxicity. Among various lipid species, the usual suspects are essentially the non-esterified fatty acids (NEFA), in particular the saturated ones such as palmitate. This review describes the fundamentals and the latest advances of research on the role of fatty acids in ß-cells. This includes intracellular pathways and receptor-mediated signaling, both participating in regulated glucose-stimulated insulin secretion as well as being implicated in ß-cell dysfunction. The discussion extends to the contribution of high glucose exposure, or glucotoxicity, to ß-cell defects. Combining glucotoxicity and lipotoxicity results in the synergistic and more deleterious glucolipotoxicity effect. In recent years, alternative roles for intracellular lipids have been uncovered, pointing to a protective function in case of nutrient overload. This requires dynamic storage of NEFA as neutral lipid droplets within the ß-cell, along with active glycerolipid/NEFA cycle allowing subsequent recruitment of lipid species supporting glucose-stimulated insulin secretion. Overall, the latest studies have revealed the two faces of the same coin.

Comparative Analysis of Dietary Habits and Obesity Prediction: Body Mass Index versus Body Fat Percentage Classification Using Bioelectrical Impedance Analysis

Background: Obesity remains a widely debated issue, often criticized for the limitations in its identification and classification. This study aims to compare two distinct systems for classifying obesity: body mass index (BMI) and body fat percentage (BFP) as assessed by bioelectrical impedance analysis (BIA). By examining these measures, the study seeks to clarify how different metrics of body composition influence the identification of obesity-related risk factors. Methods: The study enrolled 1255 adults, comprising 471 males and 784 females, with a mean age of 36 ± 12 years. Participants exhibited varying degrees of weight status, including optimal weight, overweight, and obesity. Body composition analysis was conducted using the TANITA Body Composition Analyzer BC-418 MA III device (T5896, Tokyo, Japan), evaluating the following parameters: current weight, basal metabolic rate (BMR), adipose tissue (%), muscle mass (%), and hydration status (%). Results: Age and psychological factors like cravings, fatigue, stress, and compulsive eating were significant predictors of obesity in the BMI model but not in the BFP model. Additionally, having a family history of diabetes was protective in the BMI model (OR: 0.33, 0.11-0.87) but increased risk in the BFP model (OR: 1.66, 1.01-2.76). The BMI model demonstrates exceptional predictive ability (AUC = 0.998). In contrast, the BFP model, while still performing well, exhibits a lower AUC (0.975), indicating slightly reduced discriminative power compared to the BMI model. Conclusions: BMI classification demonstrates superior predictive accuracy, specificity, and sensitivity. This suggests that BMI remains a more reliable measure for identifying obesity-related risk factors compared to the BFP model.

MSR1-dependent efferocytosis improved ischemia-reperfusion injury following aged-donor liver transplantation in mice by regulating the pro-resolving polarisation of macrophages

Compared with young liver donors, aged liver donors are more susceptible to ischemia-reperfusion injury (IRI) following transplantation, which may be related to excessive inflammatory response and macrophage dysfunction, but the specific mechanism is unclear. Macrophage scavenger receptor 1 (MSR1) is a member of the scavenger receptor family, and plays an important regulatory role in inflammation response and macrophage function regulation. But its role in IRI following aged-donor liver transplantation is still unclear. This study demonstrates that MSR1 expression is decreased in macrophages from aged donor livers, inhibiting their efferocytosis and pro-resolving polarisation. Decreased MSR1 is responsible for the more severe IRI suffered by aged donor livers. Overexpression of MSR1 using F4/80-labelled AAV9 improved intrahepatic macrophage efferocytosis and promoted pro-resolving polarisation, ultimately ameliorating IRI following aged-donor liver transplantation. In vitro co-culture experiments further showed that overexpression of MSR1 promoted an increase in calcium concentration, which further activated the PI3K-AKT-GSK3β pathway, and induced the upregulation of β-catenin. Overall, MSR1-dependent efferocytosis promoted the pro-resolving polarisation of macrophages through the PI3K-AKT-GSK3β pathway-induced up-regulating of β-catenin leading to improved IRI following aged-donor liver transplantation.

Changing landscape of liver transplant in the United States-time for a new innovative way to define and utilize the "non-standard liver allograft"-a proposal

Since the first liver transplant was performed over six decades ago, the landscape of liver transplantation in the US has seen dramatic evolution. Numerous advancements in perioperative and operative techniques have resulted in major improvements in graft and patient survival rates. Despite the increase in transplants performed over the years, the waitlist mortality rate continues to remain high. The obesity epidemic and the resultant metabolic sequelae continue to result in more marginal donors and challenging recipients. In this review, we aim to highlight the changing characteristics of liver transplant recipients and liver allograft donors. We focus on issues relevant in successfully transplanting a high model for end stage liver disease recipient. We provide insights into the current use of terms and definitions utilized to discuss marginal allografts, discuss the need to look into more consistent ways to describe these organs and propose two new concepts we coin as "Liver Allograft Variables" (LAV) and "Liver Allograft Composite Score" (LACS) for this. We discuss the development of spectrum of risk indexes as a dynamic tool to characterize an allograft in real time. We believe that this concept has the potential to optimize the way we allocate, utilize and transplant livers across the US.

Mitochondria-targeted esculetin and metformin delay endothelial senescence by promoting fatty acid β-oxidation: Relevance in age-associated atherosclerosis

Impaired mitochondrial fatty acid β-oxidation (FAO) plays a role in the onset of several age-associated diseases, including atherosclerosis. In the current work, we investigated the efficacies of mitochondria-targeted esculetin (Mito-Esc) and metformin in enhancing FAO in human aortic endothelial cells (HAECs), and its relevance in the delay of cellular senescence and age-associated atherosclerotic plaque formation in Apoe-/- mice. Chronic culturing of HAECs with either Mito-Esc or metformin increased oxygen consumption rates (OCR), and caused delay in senescence features. Conversely, etomoxir (CPT1 inhibitor) reversed Mito-Esc- and metformin-induced OCR, and caused premature endothelial senescence. Interestingly, Mito-Esc, unlike metformin, in the presence of etomoxir failed to preserve OCR. Thereby, underscoring Mito-Esc's exclusive reliance on FAO as an energy source. Mechanistically, chronic culturing of HAECs with either Mito-Esc or metformin led to AMPK activation, increased CPT1 activity, and acetyl-CoA levels along with a concomitant reduction in malonyl-CoA levels, and lipid accumulation. Similar results were observed in Apoe-/- mice aorta and liver tissue with a parallel reduction in age-associated atherosclerotic plaque formation and degeneration of liver with either Mito-Esc or metformin administration. Together, Mito-Esc and metformin by potentiating FAO, may have a role in the delay of cellular senescence by modulating mitochondrial function.

Adipose tissue as a linchpin of organismal ageing

Ageing is a conserved biological process, modulated by intrinsic and extrinsic factors, that leads to changes in life expectancy. In humans, ageing is characterized by greatly increased prevalence of cardiometabolic disease, type 2 diabetes and disorders associated with impaired immune surveillance. Adipose tissue displays species-conserved, temporal changes with ageing, including redistribution from peripheral to central depots, loss of thermogenic capacity and expansion within the bone marrow. Adipose tissue is localized to discrete depots, and also diffusely distributed within multiple organs and tissues in direct proximity to specialized cells. Thus, through their potent endocrine properties, adipocytes are capable of modulating tissue and organ function throughout the body. In addition to adipocytes, multipotent progenitor/stem cells in adipose tissue play a crucial role in maintenance and repair of tissues throughout the lifetime. Adipose tissue may therefore be a central driver for organismal ageing and age-associated diseases. Here we review the features of adipose tissue during ageing, and discuss potential mechanisms by which these changes affect whole-body metabolism, immunity and longevity. We also explore the potential of adipose tissue-targeted therapies to ameliorate age-associated disease burdens.

Circulating Fatty Acids Associate with Metabolic Changes in Adolescents Living with Obesity

Fatty acids play a crucial role in obesity development and in the comorbidities of obesity in both adults and children. This study aimed to assess the impact of circulating fatty acids on biomarkers of metabolic health of adolescents living with obesity. Parameters such as blood lipids, redox status, and leukocyte telomere length (rLTL) were measured alongside the proportions of individual fatty acids. The Mann-Whitney U test revealed that individuals with obesity exhibited an unfavorable lipid and redox status compared to the control normal weight group. The group with obesity also had lower plasma n-3 polyunsaturated fatty acids (PUFAs) and a higher ratio of n-6 to n-3 PUFAs than the control group. They also had a shorter rLTL, indicating accelerated biological aging. There was an inverse association of rLTL and plasma n-6-to-n-3 PUFA ratio. Future studies should explore the impact of recommended nutrition plans and increased physical activity on these parameters to determine if these interventions can enhance the health and well-being of adolescents with obesity, knowing that early obesity can track into adulthood.

Altered Osteoblast Metabolism with Aging Results in Lipid Accumulation and Oxidative Stress Mediated Bone Loss

Cellular aging is associated with dysfunction of numerous tissues affecting multiple organ systems. A striking example of this is related to age-related bone loss, or osteoporosis, increasing fracture incidence. Interestingly, the two compartments of bone, cortical and cancellous or trabecular, rely on different mechanisms for development and maintenance during 'normal' aging. At a cellular level, the aging process disturbs a multitude of intracellular pathways. In particular, alterations in cellular metabolic functions thereby impacting cellular bioenergetics have been implicated in multiple tissues. Therefore, this study aimed to characterize how metabolic processes were altered in bone forming osteoblasts in aged mice compared to young mice. Metabolic flux analyses demonstrated both stromal cells and mature, matrix secreting osteoblasts from aged mice exhibited mitochondrial dysfunction. This was also accompanied by a lack of adaptability or metabolic flexibility to utilize exogenous substrates compared to osteoblasts cultured from young mice. Additionally, lipid droplets accumulated in both early stromal cells and mature osteoblasts from aged mice, which was further depicted as increased lipid content within the bone cortex of aged mice. Global transcriptomic analysis of the bone further supported these metabolic data as enhanced oxidative stress genes were up-regulated in aged mice, while osteoblast-related genes were down-regulated when compared to the young mice. Collectively, these data suggest that aging results in altered osteoblast metabolic handling of both exogenous and endogenous substrates which could contribute to age-related osteoporosis.

Does excess body weight accelerate immune aging?

BACKGROUND

Overweight and obesity in older adults increase the risk of a range of comorbidities by sustaining chronic inflammation and thus enhancing immunosenescence. This study aimed to assess whether excess body mass affected disproportion in T lymphocytes. Therefore, the study was designed to explain whether excess body mass in older individuals affected the disproportion in numbers of T lymphocytes and whether anthropometric indices and immune risk profile expressed as CD4/CD8 ratio are diagnostically useful in the analysis of immunosenescence.

MATERIALS & METHODS

One hundred three individuals aged 73.6 ± 3.1 years were allocated to the normal body mass (body mass index (BMI) 18.5-24.9 kg/m2,n = 39), the pre-obesity (BMI 25.0-29.9 kg/m2, n = 44) or the obesity (BMI ≥30.0 kg/m2, n = 20) group, based on WHO recommendations. Details on the subjects' medical history and lifestyle were obtained by health questionnaire. Anthropometric analysis was performed by bioelectrical impedance method, biochemical analysis was made by the automatic analyzer and ELISA immunoassays, and T and B lymphocyte counts were determined by eight-parameter flow cytometry. Additionally, visceral adiposity index, body adiposity index (BAI), and body shape index (ABSI) were evaluated based on body circumference, BMI and lipid-lipoprotein profile measurements.

RESULTS

The highest percentage of CD3+CD4+ T lymphocytes (59.4 ± 12.6 %) and the lowest CD3+CD8+ T lymphocytes (31.6 ± 10.0 %) were noted in patients the obesity group. The highest cut-off value of 1.9 for CD4/CD8 ratio was recorded in the normal body mass vs pre-obesity model. CD4/CD8 ratio > 2.5 was recorded in >20 % of our pre-obesity and obesity groups while 64.5 % of the normal body mass group had CD4/CD8 ratio < 1. High diagnostic usefulness was demonstrated for both BAI and lipid accumulation product (LAP) (AUC values of ~0.800 and ~ 0.900 respectively) in three models: normal body mass vs pre-obesity, normal body mass vs obesity, and pre-obesity vs obesity.

CONCLUSION

The odds ratios (OR) for CD4/CD8 ratio in the normal body mass vs obesity model (OR = 16.1, 95%CI 3.8-93.6) indicated a potential diagnostic value of T lymphocytes for clinical prognosis of immune aging in relation to excess body weight in older adults. High values of AUC obtained for the following models: CD4/CD8 + BAI (AUC = 0.927), CD4/CD8 + LAP (AUC = 1.00), CD4/CD8 + ABSI (AUC = 0.865) proved to provide excellent discrimination between older adults with obesity and with normal body mass.

Microbial-Based Bioactive Compounds to Alleviate Inflammation in Obesity

The increased prevalence of obesity with several other metabolic disorders, including diabetes and non-alcoholic fatty liver disease, has reached global pandemic proportions. Lifestyle changes may result in a persistent positive energy balance, hastening the onset of these age-related disorders and consequently leading to a diminished lifespan. Although suggestions have been raised on the possible link between obesity and the gut microbiota, progress has been hampered due to the extensive diversity and complexities of the gut microbiota. Being recognized as a potential biomarker owing to its pivotal role in metabolic activities, the dysregulation of the gut microbiota can give rise to a persistent low-grade inflammatory state associated with chronic diseases during aging. This chronic inflammatory state, also known as inflammaging, induced by the chronic activation of the innate immune system via the macrophage, is controlled by the gut microbiota, which links nutrition, metabolism, and the innate immune response. Here, we present the functional roles of prebiotics, probiotics, synbiotics, and postbiotics as bioactive compounds by underscoring their putative contributions to (1) the reduction in gut hyperpermeability due to lipopolysaccharide (LPS) inactivation, (2) increased intestinal barrier function as a consequence of the upregulation of tight junction proteins, and (3) inhibition of proinflammatory pathways, overall leading to the alleviation of chronic inflammation in the management of obesity.

Aging adipose tissue, insulin resistance, and type 2 diabetes

With the increase of population aging, the prevalence of type 2 diabetes (T2D) is also rising. Aging affects the tissues and organs of the whole body, which is the result of various physiological and pathological processes. Adipose tissue has a high degree of plasticity and changes with aging. Aging changes the distribution of adipose tissue, affects adipogenesis, browning characteristics, inflammatory status and adipokine secretion, and increases lipotoxicity. These age-dependent changes in adipose tissue are an important cause of insulin resistance and T2D. Understanding adipose tissue changes can help promote healthy aging process. This review summarizes changes in adipose tissue ascribable to aging, with a focus on the role of aging adipose tissue in insulin resistance and T2D.

Lipid droplets, autophagy, and ageing: A cell-specific tale

Lipid droplets are the essential organelle for storing lipids in a cell. Within the variety of the human body, different cells store, utilize and release lipids in different ways, depending on their intrinsic function. However, these differences are not well characterized and, especially in the context of ageing, represent a key factor for cardiometabolic diseases. Whole body lipid homeostasis is a central interest in the field of cardiometabolic diseases. In this review we characterize lipid droplets and their utilization via autophagy and describe their diverse fate in three cells types central in cardiometabolic dysfunctions: adipocytes, hepatocytes, and macrophages.

Animal protein hydrolysate reduces visceral fat and inhibits insulin resistance and hepatic steatosis in aged mice

BACKGROUND/OBJECTIVES

An increasing life expectancy in society has burdened healthcare systems substantially because of the rising prevalence of age-related metabolic diseases. This study compared the effects of animal protein hydrolysate (APH) and casein on metabolic diseases using aged mice.

MATERIALS/METHODS

Eight-week-old and 50-week-old C57BL/6J mice were used as the non-aged (YC group) and aged controls (NC group), respectively. The aged mice were divided randomly into 3 groups (NC, low-APH [LP], and high-APH [HP] and fed each experimental diet for 12 weeks. In the LP and HP groups, casein in the AIN-93G diet was substituted with 16 kcal% and 24 kcal% APH, respectively. The mice were sacrificed when they were 63-week-old, and plasma and hepatic lipid, white adipose tissue weight, hepatic glucose, lipid, and antioxidant enzyme activities, immunohistochemistry staining, and mRNA expression related to the glucose metabolism on liver and muscle were analyzed.

RESULTS

Supplementation of APH in aging mice resulted in a significant decrease in visceral fat (epididymal, perirenal, retroperitoneal, and mesenteric fat) compared to the negative control (NC) group. The intraperitoneal glucose tolerance test and area under the curve analysis revealed insulin resistance in the NC group, which was alleviated by APH supplementation. APH supplementation reduced hepatic gluconeogenesis and increased glucose utilization in the liver and muscle. Furthermore, APH supplementation improved hepatic steatosis by reducing the hepatic fatty acid and phosphatidate phosphatase activity while increasing the hepatic carnitine palmitoyltransferase activity. Furthermore, in the APH supplementation groups, the red blood cell (RBC) thiobarbituric acid reactive substances and hepatic H2O2 levels decreased, and the RBC glutathione, hepatic catalase, and glutathione peroxidase activities increased.

CONCLUSIONS

APH supplementation reduced visceral fat accumulation and alleviated obesity-related metabolic diseases, including insulin resistance and hepatic steatosis, in aged mice. Therefore, high-quality animal protein APH that reduces the molecular weight and enhances the protein digestibility-corrected amino acid score has potential as a dietary supplement for healthy aging.

Global burden and epidemic trends of gout attributable to high body mass index from 1990 to 2019

Introduction

Gout is an inflammatory and metabolic disease characterized by arthritis and elevation of the serum uric acid (SUA) level. More and more studies have shown that high body mass index (BMI) has become one of the most important risk factors for gout.

Material and methods

We used the data of gout burden attributed to high body mass index (BMI) from global burden of disease (GBD) study 2019 to provide insights for reducing the global burden of gout.

Results

From 1990 to 2019, the prevalence and DALYs of gout caused by high BMI worldwide has been increasing. The burden of gout caused by high BMI is heavier in the elderly male group and regions with high SDI worldwide.

Conclusions

Our findings provide evidence for the burden of gout caused by high BMI. Developing a weight management plan and lifestyle habits for groups severely affected by gout will effectively reduce the global disease and economic burden.

Mechanism of Obesity-Related Lipotoxicity and Clinical Perspective

The link between cellular exposure to fatty acid species and toxicity phenotypes remains poorly understood. However, structural characterization and functional profiling of human plasma free fatty acids (FFAs) analysis has revealed that FFAs are located either in the toxic cluster or in the cluster that is transcriptionally responsive to lipotoxic stress and creates genetic risk factors. Genome-wide short hairpin RNA screen has identified more than 350 genes modulating lipotoxicity. Hypertrophic adipocytes in obese adipose are both unable to expand further to store excess lipids in the diet and are resistant to the antilipolytic action of insulin. In addition to lipolysis, the inability of packaging the excess lipids into lipid droplets causes circulating fatty acids to reach toxic levels in non-adipose tissues. Deleterious effects of accumulated lipid in non-adipose tissues are known as lipotoxicity. Although triglycerides serve a storage function for long-chain non-esterified fatty acid and their products such as ceramide and diacylglycerols (DAGs), overloading of palmitic acid fraction of saturated fatty acids (SFAs) raises ceramide levels. The excess DAG and ceramide load create harmful effects on multiple organs and systems, inducing chronic inflammation in obesity. Thus, lipotoxic inflammation results in β cells death and pancreatic islets dysfunction. Endoplasmic reticulum stress stimuli induce lipolysis by activating cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) and extracellular signal-regulated kinase (Erk) 1/2 signaling in adipocytes. However, palmitic acid-induced endoplasmic reticulum stress-c-Jun N-terminal kinase (JNK)-autophagy axis in hypertrophic adipocytes is a pro-survival mechanism against endoplasmic reticulum stress and cell death induced by SFAs. Endoplasmic reticulum-localized acyl-coenzyme A (CoA): glycerol-3-phosphate acyltransferase (GPAT) enzymes are mediators of lipotoxicity, and inhibiting these enzymes has therapeutic potential for lipotoxicity. Lipotoxicity increases the number of autophagosomes, which engulf palmitic acid, and thus suppress the autophagic turnover. Fatty acid desaturation promotes palmitate detoxification and storages into triglycerides. As therapeutic targets of glucolipotoxicity, in addition to caloric restriction and exercise, there are four different pharmacological approaches, which consist of metformin, glucagon-like peptide 1 (GLP-1) receptor agonists, peroxisome proliferator-activated receptor-gamma (PPARγ) ligands thiazolidinediones, and chaperones are still used in clinical practice. Furthermore, induction of the brown fat-like phenotype with the mixture of eicosapentanoic acid and docosahexaenoic acid appears as a potential therapeutic application for treatment of lipotoxicity.

Succinate Enhances Lipolysis and Decreases Adipocytes Size in Both Subcutaneous and Visceral Adipose Tissue from High-Fat-Diet-Fed Obese Mice

Obesity is a risk factor for many chronic diseases related to the overexpansion of adipose tissue during obesity, leading to metabolic dysfunction and ectopic lipids. Previous studies reported a close relationship between succinate and obesity and its co-morbidities, and studies have also reported on its anti-obesity potential. To confirm its efficacy in obesity interventions, we supplemented mice with obesity induced by a high-fat diet with succinate (1.5% m/v in drinking water) for 11 weeks without changing the diet. After succinate supplementation, the changes in body weight, adipose tissue deposition, glucose tolerance, energy expenditure and lipid metabolism were evaluated. It was found that succinate supplementation significantly decreased subcutaneous adipose tissue (HFD: 4239.3 ± 211.2 mg; HFD-SA: 3268.9 ± 265.7 mg. p < 0.05), triglyceride contents (decreased by 1.53 mmol/g and 0.39 mmol/g in eWAT and ingWAT, respectively, p < 0.05) and NEFA (decreased by 1.41 μmol/g and 1.31 μmol/g in eWAT and ingWAT, respectively, p < 0.05). The adipocytes' sizes all significantly decreased in both subcutaneous and visceral adipose tissue (the proportion of adipocytes with diameters larger than 100 μm in eWAT and ingWAT decreased by 16.83% and 11.96%, respectively. p < 0.05). Succinate significantly enhanced lipolysis in adipose tissue (eWAT: Adrb3, Hsl and Plin1; ingWAT: Hsl and CPT1a; p < 0.05), whereas the expression of lipogenesis-related genes remained unchanged (p > 0.05). Succinate supplementation also enhanced the activity of BAT by stimulating the expression of Ucp1 and Cidea (p < 0.05). Our results reported that succinate has a potential beneficial effect on obesity pathogenesis but cannot efficiently decrease bodyweight.

A novel combination of metformin and resveratrol alleviates hepatic steatosis by activating autophagy through the cAMP/AMPK/SIRT1 signaling pathway

Nonalcoholic fatty liver disease (NAFLD) is a prevalent liver disorder that is associated with the accumulation of triglycerides (TG) in hepatocytes. Resveratrol (RSV), as a natural product, and metformin have been reported to have potential lipid-lowering effects for the treatment of NAFLD via autophagy, but the combined effects of both have not yet been studied. The current study aimed to investigate the role of autophagy in the lipid-lowering effects of RSV, alone and in combination with metformin, on the hepatic steatosis model of HepG2 cells and elucidate the mechanism of action. Triglyceride measurement and real-time PCR showed that RSV-metformin reduced lipid accumulation and the expression of lipogenic genes in palmitic acid (PA)-induced HepG2 cells. Additionally, the LDH release assay indicated that this combination protected HepG2 cells against PA-induced cell death through autophagy. The western blotting analysis revealed that RSV-metformin induced autophagy by reducing the expression of p62 and increasing LC3-I and LC3-II proteins. This combination also enhanced cAMP, phosphorylated AMP-activated protein kinase (p-AMPK), and Beclin-1 levels in HepG2 cells. Furthermore, SIRT1 inhibitor treatment inhibited autophagy induced by RSV-metformin, which indicated the autophagy induction is SIRT1-dependent. This study demonstrated for the first time that RSV-metformin reduced hepatic steatosis by triggering autophagy via the cAMP/AMPK/SIRT1 signaling pathway.

Factors associated with the combination of general and abdominal obesity in middle-aged and older Korean women: a cross-sectional study

BACKGROUND

To identify factors associated with general and abdominal obesity in middle-aged and older Korean women based on the biopsychosocial model.

METHODS

Data from 4,076 women aged ≥45 years who participated in the Korea National Health and Nutrition Examination Survey from 2015 to 2020 were analyzed. Complex sampling analysis was performed using IBM SPSS ver. 26.0.

RESULTS

The combination of general and abdominal obesity was positively associated with age ≥65 years, postmenopausal status, and without breastfeeding experience among biomedical factors; depressive symptoms and prolonged (≥8 hours a day) sedentary behavior among psychosocial factors; and an educational level lower than middle or high school graduation and the first and second income quantiles among biosocial factors.

CONCLUSION

Healthcare providers in communities and public societies should screen for risk factors for the combination of general and abdominal obesity while considering non-modifiable biomedical (e.g., age) and biosocial factors (e.g., educational level). In addition, intervention strategies should be developed by considering modifiable psychosocial factors such as sedentary behavior.

Effect of oral cannabis administration on the fat depots of obese and streptozotocin-induced diabetic rats

The prevalence of obesity and insulin-resistance is on the rise, globally. Cannabis have been shown to have anti-diabetic/obesity properties, however, the effect mediated at various fat depots remains to be clarified. The aim of this study was to (1) investigate the anti-diabetic property of an oral cannabis administration in an obese and streptozotocin-induced diabetic rat model and (2) to determine and compare the effect mediated at the peritoneal and intramuscular fat level. Cannabis concentration of 1.25 mg/kg body weight (relative to THC content) was effective in reversing insulin-resistance in the rat model, unlike the other higher cannabinoid concentrations. At the peritoneal fat level, gene expression of fat beigeing markers, namely Cidea and UCP1, were significantly increased compared to the untreated control. At the intramuscular fat level, on the other hand, CE1.25 treatment did not promote fat beigeing but instead significantly increased mitochondrial activity, relative to the untreated control. Therefore, these findings indicate that the mechanism of action of oral cannabis administration, where glucose and lipid homeostasis is restored, is not only dependent on the dosage but also on the type of fat depot investigated.

GPSM1 impairs metabolic homeostasis by controlling a pro-inflammatory pathway in macrophages

G-protein-signaling modulator 1 (GPSM1) exhibits strong genetic association with Type 2 diabetes (T2D) and Body Mass Index in population studies. However, how GPSM1 carries out such control and in which types of cells are poorly understood. Here, we demonstrate that myeloid GPSM1 promotes metabolic inflammation to accelerate T2D and obesity development. Mice with myeloid-specific GPSM1 ablation are protected against high fat diet-induced insulin resistance, glucose dysregulation, and liver steatosis via repression of adipose tissue pro-inflammatory states. Mechanistically, GPSM1 deficiency mainly promotes TNFAIP3 transcription via the Gα_i3/cAMP/PKA/CREB axis, thus inhibiting TLR4-induced NF-κB signaling in macrophages. In addition, we identify a small-molecule compound, AN-465/42243987, which suppresses the pro-inflammatory phenotype by inhibiting GPSM1 function, which could make it a candidate for metabolic therapy. Furthermore, GPSM1 expression is upregulated in visceral fat of individuals with obesity and is correlated with clinical metabolic traits. Overall, our findings identify macrophage GPSM1 as a link between metabolic inflammation and systemic homeostasis.

Cellular enlargement - A new hallmark of aging?

Years of important research has revealed that cells heavily invest in regulating their size. Nevertheless, it has remained unclear why accurate size control is so important. Our recent study using hematopoietic stem cells (HSCs) in vivo indicates that cellular enlargement is causally associated with aging. Here, we present an overview of these findings and their implications. Furthermore, we performed a broad literature analysis to evaluate the potential of cellular enlargement as a new aging hallmark and to examine its connection to previously described aging hallmarks. Finally, we highlight interesting work presenting a correlation between cell size and age-related diseases. Taken together, we found mounting evidence linking cellular enlargement to aging and age-related diseases. Therefore, we encourage researchers from seemingly unrelated areas to take a fresh look at their data from the perspective of cell size.

Liver transplantation for NAFLD cirrhosis: Age and recent coronary angioplasty are major determinants of survival

BACKGROUND AND AIMS

Liver transplantation (LT) is the treatment of end-stage non-alcoholic liver disease (NAFLD), that is decompensated cirrhosis and/or complicated by hepatocellular carcinoma (HCC). Few data on long-term outcome are available. The aim of this study was to evaluate overall patient and graft survivals and associated predictive factors.

METHOD

This retrospective multicentre study included adult transplant patients for NAFLD cirrhosis between 2000 and 2019 in participating French-speaking centres.

RESULTS

A total of 361 patients (69.8% of male) were included in 20 centres. The median age at LT was 62.3 years [57.4-65.9] and the median MELD score was 13.9 [9.1-21.3]; 51.8% of patients had HCC on liver explant. Between 2004 and 2018, the number of LT for NAFLD cirrhosis increased by 720%. A quarter of the patients had cardiovascular history before LT. Median follow-up after LT was 39.1 months [15.8-72.3]. Patient survival at 1, 5 and 10 years after LT was 89.3%, 79.8% and 68.1% respectively. The main causes of death were sepsis (37.5%), malignancies (29.2%) and cardiovascular events (22.2%). In multivariate analysis, three risk factors for overall mortality after LT were recipient pre-LT BMI < 32 kg/m² at LT time (OR: 2.272; p = .012), pre-LT angioplasty during CV check-up (OR: 2.916; p = .016), a combined donor and recipient age over 135 years (OR: 2.020; 95%CI: p = .035).

CONCLUSION

Survival after LT for NAFLD cirrhosis is good at 5 years. Donor and recipient age, and cardiovascular history, are major prognostic factors to consider.

Identification of five genetic variants with differential effects on obesity-related traits based on age

Obesity is a major public health concern, and its prevalence generally increases with age. As the number of elderly people is increasing in the aging population, the age-dependent increase in obesity has raised interest in the underlying mechanism. To understand the genetic basis of age-related increase in obesity, we identified genetic variants showing age-dependent differential effects on obesity. We conducted stratified analyses between young and old groups using genome-wide association studies of 355,335 United Kingom Biobank participants for five obesity-related phenotypes, including body mass index, body fat percentage, waist-hip ratio, waist circumference, and hip circumference. Using t-statistic, we identified five significant lead single nucleotide polymorphisms: rs2258461 with body mass index, rs9861311 and rs429358 with body fat percentage, rs2870099 with waist-hip ratio, and rs145500243 with waist circumference. Among these single nucleotide polymorphisms, rs429358, located in APOE gene was associated with diverse age-related diseases, such as Alzheimer’s disease, coronary artery disease, age-related degenerative macular diseases, and cognitive decline. The C allele of rs429358 gradually decreases body fat percentage as one grows older in the range of 40–69 years. In conclusion, we identified five genetic variants with differential effects on obesity-related phenotypes based on age using a stratified analysis between young and old groups, which may help to elucidate the mechanisms by which age influences the development of obesity.

Resveratrol Supplementation in Obese Pregnant Rats Improves Maternal Metabolism and Prevents Increased Placental Oxidative Stress

Maternal obesity (MO) causes maternal and fetal oxidative stress (OS) and metabolic dysfunction. We investigated whether supplementing obese mothers with resveratrol improves maternal metabolic alterations and reduces OS in the placenta and maternal and fetal liver. From weaning through pregnancy female Wistar rats ate chow (C) or a high-fat diet (MO). One month before mating until 19 days’ gestation (dG), half the rats received 20 mg resveratrol/kg/d orally (Cres and MOres). At 19dG, maternal body weight, retroperitoneal fat adipocyte size, metabolic parameters, and OS biomarkers in the placenta and liver were determined. MO mothers showed higher body weight, triglycerides and leptin serum concentrations, insulin resistance (IR), decreased small and increased large adipocytes, liver fat accumulation, and hepatic upregulation of genes related to IR and inflammatory processes. Placenta, maternal and fetal liver OS biomarkers were augmented in MO. MOres mothers showed more small and fewer large adipocytes, lower triglycerides serum concentrations, IR and liver fat accumulation, downregulation of genes related to IR and inflammatory processes, and lowered OS in mothers, placentas, and female fetal liver. Maternal resveratrol supplementation in obese rats improves maternal metabolism and reduces placental and liver OS of mothers and fetuses in a sex-dependent manner.

Up-regulated LRRN2 expression as a marker for graft quality in living donor liver transplantation

The quality and size of liver grafts are critical factors that influence living‐donor liver transplantation (LDLT) function and safety. However, the biomarkers used for predicting graft quality are lacking. In this study, we sought to identify unique graft quality markers, aside from donor age, by using the livers of non‐human primates. Hepatic gene microarray expression data from young and elderly cynomolgus macaques revealed a total of 271 genes with significantly increased expression in the elderly. These candidate genes were then narrowed down to six through bioinformatics analyses. The expression patterns of these candidate genes in human donor liver tissues were subsequently examined. Importantly, we found that grafts exhibiting up‐regulated expression of these six candidate genes were associated with an increased incidence of liver graft failure. Multivariable analysis further revealed that up‐regulated expression of LRRN2 (encoding leucine‐rich repeat protein, neuronal 2) in donor liver tissue served as an independent risk factor for graft failure (odds ratio 4.50, confidence interval 2.08–9.72). Stratification based on graft expression of LRRN2 and donor age was also significantly associated with 6‐month graft survival rates. Conclusion: Up‐regulated LRRN2 expression of liver graft is significantly correlated with graft failure in LDLT. In addition, combination of graft LRRN2 expression and donor age may represent a promising marker for predicting LDLT graft quality.

Keeping the beat against time: Mitochondrial fitness in the aging heart

The process of aging strongly correlates with maladaptive architectural, mechanical, and biochemical alterations that contribute to the decline in cardiac function. Consequently, aging is a major risk factor for the development of heart disease, the leading cause of death in the developed world. In this review, we will summarize the classic and recently uncovered pathological changes within the aged heart with an emphasis on the mitochondria. Specifically, we describe the metabolic changes that occur in the aging heart as well as the loss of mitochondrial fitness and function and how these factors contribute to the decline in cardiomyocyte number. In addition, we highlight recent pharmacological, genetic, or behavioral therapeutic intervention advancements that may alleviate age-related cardiac decline.

Diabesity in Elderly Cardiovascular Disease Patients: Mechanisms and Regulators

Cardiovascular disease (CVD) is the leading cause of death in the world. In 2019, 550 million people were suffering from CVD and 18 million of them died as a result. Most of them had associated risk factors such as high fasting glucose, which caused 134 million deaths, and obesity, which accounted for 5.02 million deaths. Diabesity, a combination of type 2 diabetes and obesity, contributes to cardiac, metabolic, inflammation and neurohumoral changes that determine cardiac dysfunction (diabesity-related cardiomyopathy). Epicardial adipose tissue (EAT) is distributed around the myocardium, promoting myocardial inflammation and fibrosis, and is associated with an increased risk of heart failure, particularly with preserved systolic function, atrial fibrillation and coronary atherosclerosis. In fact, several hypoglycaemic drugs have demonstrated a volume reduction of EAT and effects on its metabolic and inflammation profile. However, it is necessary to improve knowledge of the diabesity pathophysiologic mechanisms involved in the development and progression of cardiovascular diseases for comprehensive patient management including drugs to optimize glucometabolic control. This review presents the mechanisms of diabesity associated with cardiovascular disease and their therapeutic implications.

SERPINA3C ameliorates adipose tissue inflammation through the Cathepsin G/Integrin/AKT pathway

OBJECTIVE

Due to the increasing prevalence of obesity and insulin resistance, there is an urgent need for better treatment of obesity and its related metabolic disorders. This study aimed to elucidate the role of SERPINA3C, an adipocyte secreted protein, in obesity and related metabolic disorders.

METHODS

Male wild type (WT) and knockout (KO) mice were fed with high-fat diet (HFD) for 16 weeks, adiposity, insulin resistance, and inflammation were assessed. AAV-mediated overexpression of SERPINA3C was injected locally in inguinal white adipose tissue (iWAT) to examine the effect of SERPINA3C. In vitro analyses were conducted in 3T3-L1 adipocytes to explore the molecular pathways underlying the function of SERPINA3C.

RESULTS

Functional exploration of the SERPINA3C knockout mice revealed that SERPINA3C deficiency led to an impaired metabolic phenotype (more severe obesity, lower metabolic rates, worse glucose intolerance and insulin insensitivity), which was associated with anabatic inflammation and apoptosis of white adipose tissues. Consistent with these results, overexpression of SERPINA3C in inguinal adipose tissue protected mice against diet-induced obesity and metabolic disorders with less inflammation and apoptosis in adipose tissue. Mechanistically, SERPINA3C inhibited Cathepsin G activity, acting as a serine protease inhibitor, which blocked Cathepsin G-mediated turnover of α5/β1 Integrin protein. Then, the preserved integrity (increase) of α5/β1 Integrin signaling activated AKT to decrease JNK phosphorylation, thereby inhibiting inflammation and promoting insulin sensitivity in adipocytes.

CONCLUSIONS/INTERPRETATION

These findings demonstrate a previously unknown SERPINA3C/Cathepsin G/Integrin/AKT pathway in regulating adipose tissue inflammation, and suggest the therapeutic potential of targeting SERPINA3C/Cathepsin G axis in adipose tissue for the treatment of obesity and metabolic diseases.

Normothermic Machine Perfusion—Improving the Supply of Transplantable Livers for High-Risk Recipients

The effectiveness of liver transplantation to cure numerous diseases, alleviate suffering, and improve patient survival has led to an ever increasing demand. Improvements in preoperative management, surgical technique, and postoperative care have allowed increasingly complicated and high-risk patients to be safely transplanted. As a result, many patients are safely transplanted in the modern era that would have been considered untransplantable in times gone by. Despite this, more gains are possible as the science behind transplantation is increasingly understood. Normothermic machine perfusion of liver grafts builds on these gains further by increasing the safe use of grafts with suboptimal features, through objective assessment of both hepatocyte and cholangiocyte function. This technology can minimize cold ischemia, but prolong total preservation time, with particular benefits for suboptimal grafts and surgically challenging recipients. In addition to more physiological and favorable preservation conditions for grafts with risk factors for poor outcome, the extended preservation time benefits operative logistics by allowing a careful explant and complicated vascular reconstruction when presented with challenging surgical scenarios. This technology represents a significant advancement in graft preservation techniques and the transplant community must continue to incorporate this technology to ensure the benefits of liver transplant are maximized.

Conventional type 1 dendritic cells protect against age-related adipose tissue dysfunction and obesity

Conventional dendritic cells (cDCs) scan and integrate environmental cues in almost every tissue, including exogenous metabolic signals. While cDCs are critical in maintaining immune balance, their role in preserving energy homeostasis is unclear. Here, we showed that Batf3-deficient mice lacking conventional type 1 DCs (cDC1s) had increased body weight and adiposity during aging. This led to impaired energy expenditure and glucose tolerance, insulin resistance, dyslipidemia, and liver steatosis. cDC1 deficiency caused adipose tissue inflammation that was preceded by a paucity of NK1.1⁺ invariant NKT (iNKT) cells. Accordingly, among antigen-presenting cells, cDC1s exhibited notable induction of IFN-γ production by iNKT cells, which plays a metabolically protective role in lean adipose tissue. Flt3L treatment, which expands the dendritic cell (DC) compartment, mitigated diet-induced obesity and hyperlipidemia in a Batf3-dependent manner. This effect was partially mediated by NK1.1⁺ cells. These results reveal a new critical role for the cDC1-iNKT cell axis in the regulation of adipose tissue homeostasis.

Body mass index (BMI) and obesity in Nigerians with schizophrenia

BACKGROUND

Few Nigerian studies have examined BMI in people with schizophrenia. The aims of the present study were to assess the prevalence and distribution of obesity in Nigerians with schizophrenia and to examine the clinical correlates of BMI and obesity.

METHODS

A total of 207 people with schizophrenia met the inclusion criteria and were evaluated for BMI.The Positive and Negative Syndrome Scale (PANSS), Hamilton Depression Rating Scale (HDRS), Social and Occupational Functioning Assessment Scale (SOFAS) were rated for all participants. Anthropometric measures such as weight and height were taken using a standard protocol.

RESULTS

The prevalence of obesity was 12.6%. The non-obese participants were made up of underweight 24 (11.7%), normal weight 118 (57%) and overweight 38 (18.4%). Compared to non-obese participants, obese participants were older, more educated, more likely to be employed, had higher incomes, lower PANSS score (negative subscale), had fewer female participants, and better social and occupational functioning (p < 0.05). BMI was positively correlated with age and monthly income. In the adjusted model, age, gender and education were independently associated with obesity while only age was associated with BMI.

CONCLUSION

The present study suggests that unlike in high-income countries, obese patients with schizophrenia in Nigeria have better social and psychological functioning than non-obese patients.

Prevalence of central obesity and associated factors in Ethiopia: A systematic review and meta-analysis

INTRODUCTION

Obesity is a global public health concern that is now on the rise, especially in low- and middle-income nations. Despite the fact that there are several studies reporting the prevalence of central obesity among adults in Ethiopia, there is a lack of a systematic review and meta-analysis synthesizing the existing observational studies. Therefore, this systematic review and meta-analysis aimed to determine the prevalence of central obesity and its associated factors in Ethiopia.

METHODS

Online libraries such as PubMed, Google Scholar, Scopus, Science Direct, and Addis Ababa University were searched. Data were extracted using Microsoft Excel and analyzed using STATA statistical software (v. 16). Forest plots, Begg's rank test, and Egger's regression test were all used to check for publication bias. To look for heterogeneity, I² was computed, and an overall estimated analysis was carried out. Subgroup analysis was done by region and study setting. In addition, the pooled odds ratio for related covariates was calculated.

RESULTS

Out of 685 studies assessed, 20 met our criteria and were included in the study. A total of 12,603 people were included in the study. The prevalence of central obesity was estimated to be 37.31% [95% confidence interval (CI): 29.55-45.07]. According to subgroup analysis by study region and setting, the highest prevalence was observed in the Dire Dawa region (61.27%) and community-based studies (41.83%), respectively. Being a woman (AOR = 6.93; 95% CI: 3.02-10.85), having better socioeconomic class (AOR = 5.45; 95% CI: 0.56-10.34), being of age 55 and above (AOR = 5.23; 95% CI: 2.37-8.09), being physically inactive (AOR = 1.80; 95% CI: 1.37-2.24), being overweight (AOR = 4.00; 95% CI: 2.58-5.41), being obese (AOR = 6.82; 95% CI: 2.21-11.43), and having hypertension (AOR = 3.84; 95% CI: 1.29-6.40) were the factors associated with central obesity.

CONCLUSION

The prevalence of central obesity was high in Ethiopia. Being a woman, having a higher socioeconomic class, being older, being physically inactive, being overweight or obese, and having hypertension were all associated. Therefore, it is vital for the government and health organizations to design and implement preventive measures like early detection, close monitoring, and positive reversal of central obesity in all patients and the general population. High-quality investigations on the prevalence of central obesity in the Ethiopian people are required to better understand the status of central obesity in Ethiopia.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/PROSPERO, identifier: CRD42022329234.

Lipid-Induced Adaptations of the Pancreatic Beta-Cell to Glucotoxic Conditions Sustain Insulin Secretion

Over the last decades, lipotoxicity and glucotoxicity emerged as established mechanisms participating in the pathophysiology of obesity-related type 2 diabetes in general, and in the loss of β-cell function in particular. However, these terms hold various potential biological processes, and it is not clear what precisely they refer to and to what extent they might be clinically relevant. In this review, we discuss the basis and the last advances of research regarding the role of free fatty acids, their metabolic intracellular pathways, and receptor-mediated signaling related to glucose-stimulated insulin secretion, as well as lipid-induced β-cell dysfunction. We also describe the role of chronically elevated glucose, namely, glucotoxicity, which promotes failure and dedifferentiation of the β cell. Glucolipotoxicity combines deleterious effects of exposures to both high glucose and free fatty acids, supposedly provoking synergistic defects on the β cell. Nevertheless, recent studies have highlighted the glycerolipid/free fatty acid cycle as a protective pathway mediating active storage and recruitment of lipids. Finally, we discuss the putative correspondence of the loss of functional β cells in type 2 diabetes with a natural, although accelerated, aging process.

Morroniside Promotes PGC-1α-Mediated Cholesterol Efflux in Sodium Palmitate or High Glucose-Induced Mouse Renal Tubular Epithelial Cells

Lipid deposition is an etiology of renal damage caused by lipid metabolism disorder in diabetic nephropathy (DN). Thus, reducing lipid deposition is a feasible strategy for the treatment of DN. Morroniside (MOR), an iridoid glycoside isolated from the Chinese herb Cornus officinalis Sieb. et Zucc., is considered to be an effective drug in inhibiting oxidative stress, reducing inflammatory response, and countering apoptosis. To explore the protective mechanism of MOR in attenuating renal lipotoxicity in DN, we investigated the effect of MOR on an in vitro model of lipid metabolism disorder of DN established by stimulating mouse renal tubular epithelial cells (mRTECs) with sodium palmitate (PA) or high glucose (HG). Oil Red O and filipin cholesterol staining assays were used to determine intracellular lipid accumulation status. Results revealed that PA or HG stimulation inhibited the expressions of peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α), liver X receptors (LXR), ATP-binding cassette subfamily A member 1 (ABCA1), ABCG1, and apolipoprotein E (ApoE) in mRTECs as evidenced by western blot and quantitative real-time PCR, resulting in increased intracellular lipid deposition. Interestingly, MOR upregulated expressions of PGC-1α, LXR, ABCA1, ABCG1, and ApoE, thus reducing cholesterol accumulation in mRTECs, suggesting that MOR might promote cholesterol efflux from mRTECs via the PGC-1α/LXR pathway. Of note, silencing PGC-1α reversed the promotive effect of MOR on PA- or HG-induced cellular cholesterol accumulation. In conclusion, our results suggest that MOR has a protective effect on mRTECs under high lipid or high glucose conditions, which may be related to the promotion of intracellular cholesterol efflux mediated by PGC-1α.

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.

Lipid accumulation-induced hepatocyte senescence regulates the activation of hepatic stellate cells through the Nrf2-antioxidant response element pathway

Non-alcoholic fatty liver disease (NAFLD) has become the most prevalent chronic liver disease globally. Elderly individuals are at a higher risk of developing NAFLD with severe clinical outcomes. Although NAFLD is closely related to liver aging, the role of hepatocyte senescence in the progression of NAFLD, especially in the development of fibrosis, is still unclear. The early stage of NAFLD is mainly characterized by lipid accumulation in hepatocytes, which could lead to severe oxidative stress, causing cellular senescence. In the present study, hepatocytes cultured in the presence of free fatty acids to induce lipid deposition were used as a hepatocyte senescence model in vitro. Senescent hepatocytes significantly increased the activation of co-cultured primary hepatic stellate cells (HSCs) and the expression of pro-fibrosis molecules. Moreover, the antioxidant regulator nuclear factor erythroid 2-related factor 2 (Nrf2) that was upregulated in senescent hepatocytes was found to be related to the activation of co-cultured HSCs. The Nrf2 agonist sulforaphane, which upregulated the transcriptional activity of the Nrf2-antioxidant response element (ARE) pathway, remarkably inhibited hepatocyte senescence and its activation effect on HSCs. However, the liver tissue obtained from non-alcoholic steatohepatitis (NASH) mice with Nrf2 knockdown showed decreased antioxidation and significant liver senescence and fibrosis. In conclusion, this study confirmed that lipid accumulation induces hepatocyte senescence, which leads to HSC activation and development of hepatic fibrosis. Increasing the activity of the Nrf2-ARE antioxidant pathway in senescent hepatocytes elicited the opposite effect, suggesting that targeting Nrf2 may prevent or delay the progression of aging-related liver fibrosis in NASH.

Antidiabetic E4orf1 protein prevents hepatic steatosis and reduces markers of aging-related cellular damage in high fat fed older mice

INTRODUCTION

Older age is associated with greater prevalence of hyperinsulinemia, type 2 diabetes, and fatty liver disease. These metabolic conditions and aging are bidirectionally linked to mitochondrial dysfunction and telomere attrition. Although effectively addressing these conditions is important for influencing the health and the lifespan, it is particularly challenging in older age. We reported that E4orf1, a protein derived from human adenovirus Ad36, reduces hyperinsulinemia, improves glucose clearance, and protects against hepatic steatosis in younger mice exposed to high fat diet (HFD). Here, we tested if E4orf1 will improve glycemic control, liver fat accumulation, mitochondrial integrity, and reduce telomere attrition in older mice.

RESEARCH DESIGN AND METHODS

We used 9-month-old mice that inducibly expressed E4orf1 in adipose tissue and non-E4orf1 expressing control mice. Mice were maintained on a 60% (kcal) HFD for 20 weeks and glycemic control was determined by intraperitoneal glucose tolerance test at week 20. Following 20 weeks of HF-feeding, mice were sacrificed and liver tissues collected to determine the expression of aging genes using qRT-PCR based RT² Profiler PCR array.

RESULTS

Compared with the control mice, E4orf1 significantly improved glycemic control and reduced hepatic steatosis and fibrosis. Additionally, E4orf1 maintained markers of mitochondrial integrity and telomere attrition.

CONCLUSION

E4orf1 has the potential to improve glycemic control in older mice, and the improvement persists even after longer term exposure. E4orf1 expression also maintains mitochondrial integrity and telomere attrition, thus delaying age-associated diseases. This provides strong evidence for therapeutic utility of E4orf1 in improving age-associated metabolic and cellular changes that occur with aging in humans.

Changing Trends in Liver Transplantation: Challenges and Solutions

Despite improvements in postliver transplant outcomes through refinements in perioperative management and surgical techniques, several changing trends in liver transplantation have presented challenges. Mortality on the waitlist remains high. In the United States, Europe, and the United Kingdom, there is an increasing need for liver transplantation, primarily as a result of increased incidence of nonalcoholic steatohepatitis-related cirrhosis and cancer indications. Meanwhile, donor suitability has decreased, as donors are often older and have more comorbidities. Despite a mismatch between organ need and availability, many organs are discarded. Notwithstanding this, many solutions have been developed to overcome these challenges. Innovative techniques in allograft preservation, viability assessment, and reconditioning have allowed the use of suboptimal organs with adequate results. Refinements in surgical procedures, including live donor liver transplantations, have increased the organ pool and are decreasing the time and mortality on the waitlist. Despite many challenges, a similar number of solutions and prospects are on the horizon. This review seeks to explore the changing trends and challenges in liver transplantation and highlight possible solutions and future directions.

Beneficial effects of whole-body cryotherapy on glucose homeostasis and amino acid profile are associated with a reduced myostatin serum concentration

The study investigated the effect of single and chronic (10 sessions) whole-body cryotherapy (WBC; 3-min, − 110 °C) on amino acid (AA) profile, myostatin, fibroblast growth factor 21 (FGF21), and concentrations of brain-derived neurotrophic factor (BDNF), irisin and adiponectin in relation to glucose homeostasis. Thirty-five, healthy men were randomly split into experimental (young: 28 ± 7 years and middle-aged: 51 ± 3 years) and control groups. Blood samples were taken before and 1 h after the first and last (10th) WBC session. Baseline myostatin correlated significantly with visceral fat area, glucose, insulin, HOMA-IR and irisin (all p < 0.05). The single session of WBC induced temporary changes in AA profile, whereas chronic exposure lowered valine and asparagine concentrations (p < 0.01 and p = 0.01, respectively) compared to the baseline. The chronic WBC reduced fasting glucose (p = 0.04), FGF21 (− 35.8%, p = 0.06) and myostatin (-18.2%, p = 0.06). Still, the effects were age-dependent. The decrease of myostatin was more pronounced in middle-aged participants (p < 0.01). Concentrations of irisin and adiponectin increased in response to chronic WBC, while BDNF level remained unchanged. By improving the adipo-myokine profile, chronic WBC may reduce effectively the risk of the metabolic syndrome associated with hyperinsulinemia, increased levels of valine and asparagine, and muscle atrophy.

Buriti pulp oil did not improve high-fat diet-induced metabolic disorders in c57bl/6 mice

Metabolic syndrome (MetS) and obesity are growing in many parts of the world, becoming public health problems. It is proposed that foods with functional properties can assist in the treatment of these diseases. Crude buriti pulp oil (BPO) is a food traditionally consumed by residents in the Pantanal, Cerrado and Brazilian Amazon. It is rich in oleic acid, tocopherols and carotenoids, emerging as a potential functional food. Thus, this study aimed to evaluate the effect of the supplementation of BPO on metabolic disorders caused by a high-fat diet. Four groups of C57BL6 mice were used, a lean group with AIN-93M diet and control oil supplementation, an obese group with a high-fat diet and control oil supplementation, and two obese groups with a high-fat diet and BPO supplementation in the amounts of 50 and 100 mg/kg. BPO worsened the metabolic state caused by the high-fat diet, worsening risk factors associated with MetS, as the abdominal circumference and retroperitoneal fat, serum levels of total cholesterol, uric acid, alanine transaminase, glucose and triglycerides, and renal fat, in addition to changes in glycaemic control and oxidative stress markers. C57BL/6 mice fed with a high-fat diet and supplemented with BPO presented a worsening in metabolic risk factors associated with MetS.

Mitochondria and Calcium Homeostasis: Cisd2 as a Big Player in Cardiac Ageing

The ageing of human populations has become a problem throughout the world. In this context, increasing the healthy lifespan of individuals has become an important target for medical research and governments. Cardiac disease remains the leading cause of morbidity and mortality in ageing populations and results in significant increases in healthcare costs. Although clinical and basic research have revealed many novel insights into the pathways that drive heart failure, the molecular mechanisms underlying cardiac ageing and age-related cardiac dysfunction are still not fully understood. In this review we summarize the most updated publications and discuss the central components that drive cardiac ageing. The following characters of mitochondria-related dysfunction have been identified during cardiac ageing: (a) disruption of the integrity of mitochondria-associated membrane (MAM) contact sites; (b) dysregulation of energy metabolism and dynamic flexibility; (c) dyshomeostasis of Ca²⁺ control; (d) disturbance to mitochondria–lysosomal crosstalk. Furthermore, Cisd2, a pro-longevity gene, is known to be mainly located in the endoplasmic reticulum (ER), mitochondria, and MAM. The expression level of Cisd2 decreases during cardiac ageing. Remarkably, a high level of Cisd2 delays cardiac ageing and ameliorates age-related cardiac dysfunction; this occurs by maintaining correct regulation of energy metabolism and allowing dynamic control of metabolic flexibility. Together, our previous studies and new evidence provided here highlight Cisd2 as a novel target for developing therapies to promote healthy ageing

Physiological factors characterizing heat-vulnerable older adults: A narrative review

More frequent and intense periods of extreme heat (heatwaves) represent the most direct challenge to human health posed by climate change. Older adults are particularly vulnerable, especially those with common age-associated chronic health conditions (e.g., cardiovascular disease, hypertension, obesity, type 2 diabetes, chronic kidney disease). In parallel, the global population is aging and age-associated disease rates are on the rise. Impairments in the physiological responses tasked with maintaining homeostasis during heat exposure have long been thought to contribute to increased risk of health disorders in older adults during heatwaves. As such, a comprehensive overview of the provisional links between age-related physiological dysfunction and elevated risk of heat-related injury in older adults would be of great value to healthcare officials and policy makers concerned with protecting heat-vulnerable sectors of the population from the adverse health impacts of heatwaves. In this narrative review, we therefore summarize our current understanding of the physiological mechanisms by which aging impairs the regulation of body temperature, hemodynamic stability and hydration status. We then examine how these impairments may contribute to acute pathophysiological events common during heatwaves (e.g., heatstroke, major adverse cardiovascular events, acute kidney injury) and discuss how age-associated chronic health conditions may exacerbate those impairments. Finally, we briefly consider the importance of physiological research in the development of climate-health programs aimed at protecting heat-vulnerable individuals.

Liver osteopontin is required to prevent the progression of age-related nonalcoholic fatty liver disease

Osteopontin (OPN), a senescence-associated secretory phenotype factor, is increased in patients with nonalcoholic fatty liver disease (NAFLD). Cellular senescence has been associated with age-dependent hepatosteatosis. Thus, we investigated the role of OPN in the age-related hepatosteatosis. For this, human serum samples, animal models of aging, and cell lines in which senescence was induced were used. Metabolic fluxes, lipid, and protein concentration were determined. Among individuals with a normal liver, we observed a positive correlation between serum OPN levels and increasing age. This correlation with age, however, was absent in patients with NAFLD. In wild-type (WT) mice, serum and liver OPN were increased at 10 months old (m) along with liver p53 levels and remained elevated at 20m. Markers of liver senescence increased in association with synthesis and concentration of triglycerides (TG) in 10m OPN-deficient (KO) hepatocytes when compared to WT hepatocytes. These changes in senescence and lipid metabolism in 10m OPN-KO mice liver were associated with the decrease of 78 kDa glucose-regulated protein (GRP78), induction of ER stress, and the increase in fatty acid synthase and CD36 levels. OPN deficiency in senescent cells also diminished GRP78, the accumulation of intracellular TG, and the increase in CD36 levels. In 20m mice, OPN loss led to increased liver fibrosis. Finally, we showed that OPN expression in vitro and in vivo was regulated by p53. In conclusion, OPN deficiency leads to earlier cellular senescence, ER stress, and TG accumulation during aging. The p53-OPN axis is required to inhibit the onset of age-related hepatosteatosis.

Associations of socio-demographic factors with adiposity among immigrants in Norway: a secondary data analysis

BACKGROUND

Obesity is becoming an important public health challenge, especially among immigrants coming from low and middle income to high-income countries. In this study we examined the relationship between overweight/obesity and various socio-demographic indicators among different immigrant groups in Norway.

METHODS

We used data from the Living Conditions Survey among Immigrants 2016, conducted by Statistics Norway. Our study sample included 4194 immigrants from 12 different countries. Participants were asked about a number of topics including health, weight, height, demographic factors, length of residence and employment. We ran logistic regression analysis to determine the odds ratio (OR) of the associations between socio-demographic factors with adiposity among immigrants.

RESULTS

Approximately 53% of the sample was overweight/obese. There was a significant difference in overweight/obesity by gender, age, country of origin and marital status. Overall immigrant men were almost 52% more likely to be overweight/obese than women. Women from Somalia had the highest odds (13.1; CI: 7.4-23.1) of being overweight/obese, followed by Iraq (8.6; CI: 4.9-14.9), Pakistan (7.5; CI: 4.2-13.4), Kosovo (7.0; CI: 4.1-12.1), and Turkey (6.8; CI: 4.0-11.6) as compared to the women from Vietnam (reference). Whereas men from Turkey had the highest odds (5.2; CI: (3.2-8.3)) of being overweight/obese, followed by Poland (4.2; CI: 2.7-6.1), Bosnia (4.1; CI: (2.6-6.5) and Kosovo (3.9; CI: 2.5-6.1). The odds for obesity increased with age and odds were highest in the eldest group 45-66 years (4.3; CI: 3.2-5.8) as compared to reference group16-24 years. The odds of being overweight/obese was higher among married (1.6; CI: 1.3-1.9) and divorced/separated/widowed (1.5; CI: 1.1-2.0) as compared to singles. Education, employment status, physical activity and length of residence were not associated with the odds of being overweight/obese.

CONCLUSION

The findings of this study call attention to the importance of a greater understanding of the processes leading to obesity among certain immigrant groups in Norway. Moreover, there is a need for culturally adapted prevention strategies targeting immigrant men and women with high rates of overweight/obesity.

Lipidomics reveals carnitine palmitoyltransferase 1C protects cancer cells from lipotoxicity and senescence

Lipotoxicity, caused by intracellular lipid accumulation, accelerates the degenerative process of cellular senescence, which has implications in cancer development and therapy. Previously, carnitine palmitoyltransferase 1C (CPT1C), a mitochondrial enzyme that catalyzes carnitinylation of fatty acids, was found to be a critical regulator of cancer cell senescence. However, whether loss of CPT1C could induce senescence as a result of lipotoxicity remains unknown. An LC/MS-based lipidomic analysis of PANC-1, MDA-MB-231, HCT-116 and A549 cancer cells was conducted after siRNA depletion of CPT1C. Cellular lipotoxicity was further confirmed by lipotoxicity assays. Significant changes were found in the lipidome of CPT1C-depleted cells, including major alterations in fatty acid, diacylglycerol, triacylglycerol, oxidative lipids, cardiolipin, phosphatidylglycerol, phosphatidylcholine/phosphatidylethanolamine ratio and sphingomyelin. This was coincident with changes in expressions of mRNAs involved in lipogenesis. Histological and biochemical analyses revealed higher lipid accumulation and increased malondialdehyde and reactive oxygen species, signatures of lipid peroxidation and oxidative stress. Reduction of ATP synthesis, loss of mitochondrial transmembrane potential and down-regulation of expression of mitochondriogenesis gene mRNAs indicated mitochondrial dysfunction induced by lipotoxicity, which could further result in cellular senescence. Taken together, this study demonstrated CPT1C plays a critical role in the regulation of cancer cell lipotoxicity and cell senescence, suggesting that inhibition of CPT1C may serve as a new therapeutic strategy through induction of tumor lipotoxicity and senescence.

Molecular and Lifestyle Factors Modulating Obesity Disease

Obesity adversely affects bone health by means of multiple mechanisms, e.g., alterations in bone-regulating hormones, inflammation, and oxidative stress. Substantial evidence supports the relationship between adiposity and bone disorders in overweight/obese individuals. It is well known that the balance between mutually exclusive differentiation of progenitor cells into osteoblasts or adipocytes is controlled by different agents, including growth factors, hormones, genetic and epigenetic factors. Furthermore, an association between vitamin D deficiency and obesity has been reported. On the other hand, regular physical activity plays a key role in weight control, in the reduction of obesity-associated risks and promotes osteogenesis. The aim of this review is to highlight relevant cellular and molecular aspects for over-weight containment. In this context, the modulation of progenitor cells during differentiation as well as the role of epigenetics and microbiota in obesity disease will be discussed. Furthermore, lifestyle changes including an optimized diet as well as targeted physical activity will be suggested as strategies for the treatment of obesity disease.

Aging-Related Molecular Pathways in Chronic Cholestatic Conditions

Aging is commonly defined as the time-dependent functional decline of organs and tissues. Average life expectancy has increased considerably over the past century and is estimated to increase even further, consequently also the interest in understanding the aging processes. Although aging is not a disease, it is the major risk factor for the development of many chronic diseases. Pathologies, such as Primary Biliary Cholangitis (PBC) and Primary Sclerosing Cholangitis (PSC) are cholestatic liver diseases characterized by chronic inflammation, biliary damage and ultimately liver fibrosis, targeting specifically cholangiocytes. To date, the influence of aging in these biliary diseases is not fully understood. Currently, liver transplantation is the only solution because of lacking in efficiently therapies. Although liver cells have a high regenerative capacity, they undergo extensive molecular changes in response to aging. Following time-dependent damage induced by aging, the cells initially activate protective compensatory processes that, if hyperstimulated, can lead to the decline of regenerative ability and the development of pathologies. Recent studies have introduced novel therapeutic tools for cholangiopathies that have showed to have promising potential as novel therapies for PSC and PBC and for the development of new drugs. The recent advancements in understanding of molecular aging have undoubtedly the potential to unveil new pathways for selective drug treatments, but further studies are needed to deepen their knowledge.

The aged liver: Beyond cellular senescence

The aging of the population, the increased prevalence of chronic liver diseases in elderly and the need to broaden the list of potential liver donors enjoin us to better understand what is an aged liver. In this review, we provide a brief introduction to cellular senescence, revisit the main morphological and functional modifications of the liver induced by aging, particularly concerning metabolism, immune response and regeneration, and try to elude some of the signalling pathways responsible for these modifications. Finally, we discuss the clinical consequences of aging on chronic liver diseases and the implications of older age for donors and recipients in liver transplantation.

Could Omega 3 Fatty Acids Preserve Muscle Health in Rheumatoid Arthritis?

Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by a high prevalence of death due to cardiometabolic diseases. As observed during the aging process, several comorbidities, such as cardiovascular disorders (CVD), insulin resistance, metabolic syndrome and sarcopenia, are frequently associated to RA. These abnormalities could be closely linked to alterations in lipid metabolism. Indeed, RA patients exhibit a lipid paradox, defined by reduced levels of total, low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterol whereas the CVD risk is increased. Moreover, the accumulation of toxic lipid mediators (i.e., lipotoxicity) in skeletal muscles can induce mitochondrial dysfunctions and insulin resistance, which are both crucial determinants of CVD and sarcopenia. The prevention or reversion of these biological perturbations in RA patients could contribute to the maintenance of muscle health and thus be protective against the increased risk for cardiometabolic diseases, dysmobility and mortality. Yet, several studies have shown that omega 3 fatty acids (FA) could prevent the development of RA, improve muscle metabolism and limit muscle atrophy in obese and insulin-resistant subjects. Thereby, dietary supplementation with omega 3 FA should be a promising strategy to counteract muscle lipotoxicity and for the prevention of comorbidities in RA patients.

Hyperlipidemia Affects Tight Junctions and Pump Function in the Corneal Endothelium

Hyperlipidemia impacts on various diseases, such as atherosclerosis, hypertension, and diabetes mellitus. However, its influence, if any, on ocular tissues is largely unknown. Herein, we developed hyperlipidemic murine models by feeding 4-week-old male wild-type mice with a high-fat diet and apolipoprotein E knockout (ApoE^-/-) mice with a high-fat diet or standard diet to investigate the corneal endothelial change under hyperlipidemic conditions. Oil Red O staining showed an accumulation of lipid droplets in corneal endothelial cells (CECs) of hyperlipidemic mice. Other manifestations included a reduced cell density and distorted cell morphology, a disruption of the endothelial cell tight junctions and adhesion junctions, a reduced number of surface microvilli, down-regulation of Na⁺-K⁺-ATPase expression and function, activation of oxidative stress, changes in mitochondrial ultrastructure, and increased apoptosis. CEC recovery after injury, moreover, was diminished in hyperlipidemic mice; and high palmitate levels were found in the aqueous humor. In vitro hyperlipemia model, moreover, was found to be associated with dose-dependent CEC cytotoxicity, altered cell morphology, reduced pump function, and an induction of oxidative stress, leading to functional and pathologic changes in the corneal endothelium.