Short-term moderate diet restriction in adulthood can reverse oxidative, cardiovascular and metabolic alterations induced by postnatal overfeeding in mice

Short-Term Postnatal Overfeeding Induces Long-Lasting Cardiometabolic Syndrome in Mature and Old Mice Associated with Increased Sensitivity to Myocardial Infarction

SCOPE

Perinatal nutritional disturbances may "program" an increased cardio-metabolic risk in adulthood; however, few experimental studies have explored their effects on mature and/or old animal. This study aims to investigate the influence of postnatal overfeeding (PNOF) on cardiac function, sensitivity to ischemia-reperfusion (I-R) injury in vivo, glucose metabolism, and metabolic profile of pericardial adipose tissue (PAT) in young (4 months), adult (6 months), old (12 months), and very old (18 months) male mice.

METHODS AND RESULTS

Two days after birth, PNOF is induced by adjusting the litter size of C57BL/6 male mice to three pups/mother, while the normally fed (NF) control group is normalized to nine pups/mother. After weaning, all mice have free access to standard diet. Glucose/insulin tests and in vivo myocardial I-R injury are conducted on mice aged from 2 to 12 months, while echocardiography is performed at all ages up to 18 months. PNOF mice exhibit an early and persistent 10-20% increase in body weight and a 10% decrease in left ventricular ejection fraction throughout their lifespan. In PNOF mice aged 4, 6, and 12 months, glucose intolerance and insulin resistance are observed, as well as a 27-34% increase in infarct size. This is accompanied by a higher PAT mass with increased inflammatory status.

CONCLUSION

Short-term PNOF results in nutritional programming, inducing long-lasting alterations in glucose metabolism and cardiac vulnerability in male mice, lasting up to 12 months.

Single high-dose intravenous injection of Wharton's jelly-derived mesenchymal stem cell exerts protective effects in a rat model of metabolic syndrome

BACKGROUND

Metabolic syndrome (MetS) is a significant epidemiological problem worldwide. It is a pre-morbid, chronic and low-grade inflammatory disorder that precedes many chronic diseases. Wharton's jelly-derived mesenchymal stem cells (WJ-MSCs) could be used to treat MetS because they express high regenerative capacity, strong immunomodulatory properties and allogeneic biocompatibility. This study aims to investigate WJ-MSCs as a therapy against MetS in a rat model.

METHODS

Twenty-four animals were fed with high-fat high-fructose (HFHF) diet ad libitum. After 16 weeks, the animals were randomised into treatment groups (n = 8/group) and received a single intravenous administration of vehicle, that is, 3 × 106 cells/kg or 10 × 106 cells/kg of WJ-MSCs. A healthy animal group (n = 6) fed with a normal diet received the same vehicle as the control (CTRL). All animals were periodically assessed (every 4 weeks) for physical measurements, serum biochemistry, glucose tolerance test, cardiovascular function test and whole-body composition. Post-euthanasia, organs were weighed and processed for histopathology. Serum was collected for C-reactive protein and inflammatory cytokine assay.

RESULTS

The results between HFHF-treated groups and healthy or HFHF-CTRL did not achieve statistical significance (α = 0.05). The effects of WJ-MSCs were masked by the manifestation of different disease subclusters and continuous supplementation of HFHF diet. Based on secondary analysis, WJ-MSCs had major implications in improving cardiopulmonary morbidities. The lungs, liver and heart show significantly better histopathology in the WJ-MSC-treated groups than in the untreated CTRL group. The cells produced a dose-dependent effect (high dose lasted until week 8) in preventing further metabolic decay in MetS animals.

CONCLUSIONS

The establishment of safety and therapeutic proof-of-concept encourages further studies by improving the current therapeutic model.

Inverse Lansing Effect: Maternal Age and Provisioning Affecting Daughters' Longevity and Male Offspring Production

AbstractMaternal age effects on offspring life history are known in a variety of organisms, with offspring of older mothers typically having lower life expectancy (the Lansing effect). However, there is no consensus on the generality and mechanisms of this pattern. We tested predictions of the Lansing effect in several Daphnia magna clones and observed clone-specific magnitude and direction of the maternal age effect on offspring longevity. We also report ambidirectional, genotype-specific effects of maternal age on the propensity of daughters to produce male offspring. Focusing on two clones with contrasting life histories, we demonstrate that maternal age effects can be explained by lipid provisioning of embryos by mothers of different ages. Individuals from a single-generation maternal age reversal treatment showed intermediate life span and intermediate lipid content at birth. In the clone characterized by the "inverse Lansing effect," neonates produced by older mothers showed higher mitochondrial membrane potential in neural tissues than their counterparts born to younger mothers. We conclude that an inverse Lansing effect is possible and hypothesize that it may be caused by age-specific maternal lipid provisioning creating a calorically restricted environment during embryonic development, which in turn reduces fecundity and increases life span in offspring.

Dietary Restriction against Parkinson's Disease: What We Know So Far

Dietary restriction (DR) is defined as a moderate reduction in food intake while avoiding malnutrition. The beneficial effects of DR are being increasingly acknowledged in aging and in a series of age-related neurodegenerative disorders, for example, Parkinson's disease (PD). To date, the pathogenesis of PD remains elusive and there is no cure for it in spite of intensive research over decades. In this review, we summarize the current knowledge on the efficacy of DR on PD, focusing on the underlying mechanisms involving general metabolism, neuroendocrinolgy, neuroinflammation, gut microbiome, and so on. We anticipate that this review will provide future perspectives for PD prevention and treatment.

Loss of Nuclear Envelope Integrity and Increased Oxidant Production Cause DNA Damage in Adult Hearts Deficient in PKP2: A Molecular Substrate of ARVC

BACKGROUND

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is characterized by high propensity to life-threatening arrhythmias and progressive loss of heart muscle. More than 40% of reported genetic variants linked to ARVC reside in the PKP2 gene, which encodes the PKP2 protein (plakophilin-2).

METHODS

We describe a comprehensive characterization of the ARVC molecular landscape as determined by high-resolution mass spectrometry, RNA sequencing, and transmission electron microscopy of right ventricular biopsy samples obtained from patients with ARVC with PKP2 mutations and left ventricular ejection fraction >45%. Samples from healthy relatives served as controls. The observations led to experimental work using multiple imaging and biochemical techniques in mice with a cardiac-specific deletion of Pkp2 studied at a time of preserved left ventricular ejection fraction and in human induced pluripotent stem cell-derived PKP2-deficient myocytes.

RESULTS

Samples from patients with ARVC present a loss of nuclear envelope integrity, molecular signatures indicative of increased DNA damage, and a deficit in transcripts coding for proteins in the electron transport chain. Mice with a cardiac-specific deletion of Pkp2 also present a loss of nuclear envelope integrity, which leads to DNA damage and subsequent excess oxidant production (O2.- and H2O2), the latter increased further under mechanical stress (isoproterenol or exercise). Increased oxidant production and DNA damage is recapitulated in human induced pluripotent stem cell-derived PKP2-deficient myocytes. Furthermore, PKP2-deficient cells release H2O2 into the extracellular environment, causing DNA damage and increased oxidant production in neighboring myocytes in a paracrine manner. Treatment with honokiol increases SIRT3 (mitochondrial nicotinamide adenine dinucleotide-dependent protein deacetylase sirtuin-3) activity, reduces oxidant levels and DNA damage in vitro and in vivo, reduces collagen abundance in the right ventricular free wall, and has a protective effect on right ventricular function.

CONCLUSIONS

Loss of nuclear envelope integrity and subsequent DNA damage is a key substrate in the molecular pathology of ARVC. We show transcriptional downregulation of proteins of the electron transcript chain as an early event in the molecular pathophysiology of the disease (before loss of left ventricular ejection fraction <45%), which associates with increased oxidant production (O2.- and H2O2). We propose therapies that limit oxidant formation as a possible intervention to restrict DNA damage in ARVC.

Effects of Fasting and Lifestyle Modification in Patients with Metabolic Syndrome: A Randomized Controlled Trial

BACKGROUND

Lifestyle interventions, such as fasting, diet, and exercise, are increasingly used as a treatment option for patients with metabolic syndrome (MS). This study assesses the efficacy and safety of fasting followed by lifestyle modification in patients with MS compared to lifestyle modification only.

METHODS

Single-blind, multicenter, parallel, randomized controlled trial in two German tertiary referral hospitals in metropolitan areas.

INTERVENTIONS

(a) 5-day fasting followed by 10 weeks of lifestyle modification (modified DASH diet, exercise, mindfulness; n = 73); (b) 10 weeks of lifestyle modification only (n = 72).

MAIN OUTCOMES AND MEASURES

Co-primary outcomes were ambulatory systolic blood pressure and the homeostasis model assessment (HOMA) index at week 12. Further outcomes included anthropometric, laboratory parameters, and the PROCAM score at weeks 1, 12, and 24.

RESULTS

A total of 145 patients with metabolic syndrome (62.8% women; 59.7 ± 9.3 years) were included. No significant group differences occurred for the co-primary outcomes at week 12. However, compared to lifestyle modification only, fasting significantly reduced HOMA index (Δ = -0.8; 95% confidence interval [CI] = -1.7, -0.1), diastolic blood pressure (Δ = -4.8; 95% CI = -5.5, -4.1), BMI (Δ = -1.7; 95% CI = -2.0, -1.4), weight (Δ = -1.7; 95% CI = -2.0, -1.4), waist circumference (Δ = -2.6; 95% CI = -5.0, -0.2), glucose (Δ = -10.3; 95% CI = -19.0, -1.6), insulin (Δ = -2.9; 95% CI = -5.3, -0.4), HbA1c (Δ = -0.2; 95% CI = -0.4, -0.05;), triglycerides (Δ = -48.9; 95% CI = -81.0, -16.9), IL-6 (Δ = -1.2; 95% CI = -2.5, -0.005), and the 10-year risk of acute coronary events (Δ = -4.9; 95% CI = -9.5, -0.4) after week 1. Fasting increased uric acid levels (Δ = 1.0; 95% CI = 0.1, 1.9) and slightly reduced eGRF (Δ = -11.9; 95% CI = -21.8, -2.0). Group differences at week 24 were found for weight (Δ = -2, 7; 95% CI = -4.8, -0.5), BMI (Δ = -1.0; 95% CI = -1.8, -0.3), glucose (Δ = -7.7; 95% CI = -13.5, -1.8), HDL (Δ = 5.1; 95% CI = 1.5, 8.8), and CRP (Δ = 0.2; 95% CI = 0.03, 0.4). No serious adverse events occurred.

CONCLUSIONS

A beneficial effect at week 24 was found on weight; fasting also induced various positive short-term effects in patients with MS. Fasting can thus be considered a treatment for initializing lifestyle modification for this patient group; however, it remains to be investigated whether and how the multilayered effects of fasting can be maintained in the medium and longer term.

Effects of Caloric Restriction and Rope-Skipping Exercise on Cardiometabolic Health: A Pilot Randomized Controlled Trial in Young Adults

The aim of this study is to investigate the effects of calorie restriction (CR), rope-skipping (RS) exercise, and their joint effects on cardiometabolic health in young adults. An 8-week randomized trial was conducted on 46 undergraduates aged 19–21 y from South China. The participants were randomized into the following three groups: Calorie restriction (CR) group (n = 14), Rope-skipping (RS) group (n = 14), and CR plus RS (CR–RS) group (n = 12). At both allocation and the end of the intervention, data on anthropometry, serum metabolic, and inflammatory markers were collected. A total of 40 participants completed the intervention and were included in the analysis. After the 8-week intervention, the participants from the CR group and the CR–RS group reduced in body weight (−1.1 ± 1.7 kg, −1.3 ± 2.0 kg), body mass index (−0.4 ± 0.6 kg/m², −0.5 ± 0.7 kg/m²), body fat percentage (−1.2 ± 1.6%, −1.7 ± 1.8%), and body fat mass (−1.1 kg (−2.2, −0.3), −1.1 kg (−2.5, −0.4)) compared to the baseline (p < 0.05 or p = 0.051). For metabolic and inflammatory factors, the participants in the CR–RS group showed significant decreases in low density lipoprotein cholesterol (−0.40 mmol/L) and interleukin-8 (−0.73 mmol/L). While all the above markers showed no significant difference among the groups after intervention, in the subgroup of overweight/obese participants (n = 23), the CR–RS group had significantly lower blood pressure, fasting insulin, homeostatic model assessment of insulin resistance, tumor necrosis factor-α, and interleukin-8 levels than the CR or RS groups (p < 0.05). In conclusion, both CR and CR–RS could reduce weight and improve body composition in young adults. More importantly, in those with overweight or obesity, CR–RS intervention might be superior to either CR or RS in improving cardiometabolic health.

ω3PUFAs improve hepatic steatosis in postnatal overfed rats and HepG2 cells by inhibiting acetyl-CoA carboxylase

Postnatal overfeeding can lead to persistent increases in hepatic lipid synthesis and the risk of nonalcoholic fatty liver disease (NAFLD) in adulthood. The ω3 polyunsaturated fatty acids (ω3PUFAs) exhibit beneficial effects on NAFLD. Here, we employed a rat model and an in vitro HepG2 cell model to investigate whether fish oil (FO) affects hepatic lipid synthesis due to postnatal overfeeding. Male Sprague-Dawley were divided into litter sizes of three (small litters, SLs) or 10 (normal litters, NLs) on postnatal day 3 and were fed standard chow or FO diet beginning on postnatal week 3 to generate NL, SL, NL-FO, and SL-FO groups. The results indicated that the FO diet reduced the postnatal overfeeding-induced body weight gain and NAFLD characteristics (such as serum and liver triglyceride (TG) and hepatic steatosis). In addition, FO restored the expression of hepatic lipid metabolism-related genes (including SCD1, FASN, CPT1, LPL, ACC, and SREBP-1c) in SL-FO rats. Specifically, the activity and expression pattern of ACC were consistent with SREBP-1c. Furthermore, HepG2 cells were treated with oleic acid (OA), followed by eicosapentenoic acid (EPA), with or without SREBP-1c siRNA. The cellular lipid droplets, TG content, and the expression of ACC (by 75%) and SREBP-1c (by 45%) were increased by OA stimulation (p < .05), which was inhibited by EPA treatment. However, the effect of EPA treatment was abolished when SREBP-1c was silenced. In conclusion, ω3PUFAs-rich diet may be an effective way to reverse the developmental programming of hepatic lipid synthesis, at least partially, by inhibiting ACC through modulating SREBP-1c.

The effects of assisted reproduction technologies on metabolic health and disease†

The increasing prevalence of metabolic diseases places a substantial burden on human health throughout the world. It is believed that predisposition to metabolic disease starts early in life, a period of great susceptibility to epigenetic reprogramming due to environmental insults. Assisted reproductive technologies (ART), i.e., treatments for infertility, may affect embryo development, resulting in multiple adverse health outcomes in postnatal life. The most frequently observed alteration in ART pregnancies is impaired placental nutrient transfer. Moreover, consequent intrauterine growth restriction and low birth weight followed by catch-up growth can all predict future obesity, insulin resistance, and chronic metabolic diseases. In this review, we have focused on evidence of adverse metabolic alterations associated with ART, which can contribute to the development of chronic adult-onset diseases, such as metabolic syndrome, type 2 diabetes, and cardiovascular disease. Due to high phenotypic plasticity, ART pregnancies can produce both offspring with adverse health outcomes, as well as healthy individuals. We further discuss the sex-specific and age-dependent metabolic alterations reflected in ART offspring, and how the degree of interference of a given ART procedure (from mild to more severe manipulation of the egg) affects the occurrence and degree of offspring alterations. Over the last few years, studies have reported signs of cardiometabolic alterations in ART offspring that are detectable at a young age but that do not appear to constitute a high risk of disease and morbidity per se. These abnormal phenotypes could be early indicators of the development of chronic diseases, including metabolic syndrome, in adulthood. The early detection of metabolic alterations could contribute to preventing the onset of disease in adulthood. Such early interventions may counteract the risk factors and improve the long-term health of the individual.

Programming of Cardiovascular Dysfunction by Postnatal Overfeeding in Rodents

Nutritional environment in the perinatal period has a great influence on health and diseases in adulthood. In rodents, litter size reduction reproduces the effects of postnatal overnutrition in infants and reveals that postnatal overfeeding (PNOF) not only permanently increases body weight but also affects the cardiovascular function in the short- and long-term. In addition to increased adiposity, the metabolic status of PNOF rodents is altered, with increased plasma insulin and leptin levels, associated with resistance to these hormones, changed profiles and levels of circulating lipids. PNOF animals present elevated arterial blood pressure with altered vascular responsiveness to vasoactive substances. The hearts of overfed rodents exhibit hypertrophy and elevated collagen content. PNOF also induces a disturbance of cardiac mitochondrial respiration and produces an imbalance between oxidants and antioxidants. A modification of the expression of crucial genes and epigenetic alterations is reported in hearts of PNOF animals. In vivo, a decreased ventricular contractile function is observed during adulthood in PNOF hearts. All these alterations ultimately lead to an increased sensitivity to cardiac pathologic challenges such as ischemia-reperfusion injury. Nevertheless, caloric restriction and physical exercise were shown to improve PNOF-induced cardiac dysfunction and metabolic abnormalities, drawing a path to the potential therapeutic correction of early nutritional programming.

Size Does Matter: Litter Size Strongly Determines Adult Metabolism in Rodents

In this essay, we highlight how litter size in rodents is a strong determinant of neonatal growth and long-term metabolic health. Based on these effects, we strongly advise that scientific articles that utilize rodent models for obesity and metabolic research should include information on the litter sizes in the study to increase the data transparency of such reports.

Is Caloric Restriction Associated with Better Healthy Aging Outcomes? A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background: Global dietary patterns have gradually shifted toward a 'western type' with progressive increases in rates of metabolic imbalance. Recently, animal and human studies have revealed positive effects of caloric restriction (CR) on many health domains, giving new knowledge for prevention of ill and health promotion; Methods: We conducted a systematic review (SR) of randomized controlled trials (RCTs) investigating the role of CR on health status in adults. A meta-analysis was performed on anthropometric, cardiovascular and metabolic outcomes; Results: A total of 29 articles were retrieved including data from eight RCTs. All included RCTs were at low risk for performance bias related to objective outcomes. Collectively, articles included 704 subjects. Among the 334 subjects subjected to CR, the compliance with the intervention appeared generally high. Meta-analyses proved benefit of CR on reduction of body weight, BMI, fat mass, total cholesterol, while a minor impact was shown for LDL, fasting glucose and insulin levels. No effect emerged for HDL and blood pressure after CR. Data were insufficient for other hormone variables in relation to meta-analysis of CR effects; Conclusion: CR is a nutritional pattern linked to improved cardiometabolic status. However, evidence is limited on the multidimensional aspects of health and requires more studies of high quality to identify the precise impact of CR on health status and longevity.

Renal Programming by Transient Postnatal Overfeeding: The Role of Senescence Pathways

Background

Early nutrition influences the risk of chronic kidney diseases (CKDs) development in adulthood. Mechanisms underlying the early programming of altered renal function remain incompletely understood. This study aims at characterizing the role of cell senescence pathways in early programming of CKD after transient postnatal overfeeding.

Materials and Methods

Reduced litters of 3 mice pups and standard litters of 9 mice pups were obtained to induce overfed animals during lactation and control animals, respectively. Animals were sacrificed at 24 days (weaning) or at 7 months of life (adulthood). Body weight, blood pressure, kidney weight, and glomerular count were assessed in both groups. Senescence pathways were investigated using β-Galactosidase staining and Western blotting of P16, P21, P53, P-Rb/Rb, and Sirtuin 1 (Sirt1) proteins.

Results

Early overfed animals had a higher body weight, a higher blood pressure at adulthood, and a higher glomerular number endowment compared to the control group. A higher β-Galactosidase activity, a significant increase in P53 protein expression (p = 0.0045) and a significant decrease in P-Rb/Rb ratio (p = 0.02), were observed at weaning in animals who underwent early postnatal overfeeding. Protein expression of Sirt1, a protective factor against accelerated stress-induced senescence, was significantly decreased (p = 0.03) at weaning in early overfed animals.

Conclusion

Early postnatal overfeeding by litter size reduction is associated with increased expression of factors involved in cellular senescence pathways, and decreased expression of Sirt 1 in the mouse kidney at weaning. These alterations may contribute to CKD programming after early postnatal overfeeding.

Calorie Restriction in Adulthood Reduces Hepatic Disorders Induced by Transient Postnatal Overfeeding in Mice

Impaired early nutrition influences the risk of developing metabolic disorders in later life. We observed that transient postnatal overfeeding (OF) in mice induces long-term hepatic alterations, characterized by microsteatosis, fibrosis associated with oxidative stress (OS), and stress-induced premature senescence (SIPS). In this study, we investigated whether such changes can be reversed by moderate calorie restriction (CR). C57BL/6 male mice pups were maintained during lactation in litters adjusted to nine pups in the normal feeding (NF) group and three pups in the transient postnatal OF group. At six months of age, adult mice from the NF and OF groups were randomly assigned to an ad libitum diet or CR (daily energy supply reduced by 20%) for one month. In each group, at the age of seven months, analysis of liver structure, liver markers of OS (superoxide anion, antioxidant defenses), and SIPS (lipofuscin, p53, p21, p16, pRb/Rb, Acp53, sirtuin-1) were performed. CR in the OF group reduced microsteatosis, decreased levels of superoxide anion, and increased protein expression of catalase and superoxide dismutase. Moreover, CR decreased lipofuscin staining, p21, p53, Acp53, and p16 but increased pRb/Rb and sirtuin-1 protein expression. CR did not affect the NF group. These results suggest that CR reduces hepatic disorders induced by OF.

Ischemic Stroke Increases Heart Vulnerability to Ischemia-Reperfusion and Alters Myocardial Cardioprotective Pathways

Background and Purpose- For years, the relationship between cardiac and neurological ischemic events has been limited to overlapping pathophysiological mechanisms and common risk factors. However, acute stroke may induce dramatic changes in cardiovascular function. The aim of this study was to evaluate how prior cerebrovascular lesions affect myocardial function and signaling in vivo and ex vivo and how they influence cardiac vulnerability to ischemia-reperfusion injury. Methods- Cerebral embolization was performed in adult Wistar male rats through the injection of microspheres into the left or right internal carotid artery. Stroke lesions were evaluated by microsphere counting, tissue staining, and assessment of neurological deficit 2 hours, 24 hours, and 7 days after surgery. Cardiac function was evaluated in vivo by echocardiography and ex vivo in isolated perfused hearts. Heart vulnerability to ischemia-reperfusion injury was investigated ex vivo at different times post-embolization and with varying degrees of myocardial ischemia. Left ventricles (LVs) were analyzed with Western blotting and quantitatve real-time polymerase chain reaction. Results- Our stroke model produced large cerebral infarcts with severe neurological deficit. Cardiac contractile dysfunction was observed with an early but persistent reduction of LV fractional shortening in vivo and of LV developed pressure ex vivo. Moreover, after 20 or 30 minutes of global cardiac ischemia, recovery of contractile function was poorer with impaired LV developed pressure and relaxation during reperfusion in both stroke groups. Following stroke, circulating levels of catecholamines and GDF15 (growth differentiation factor 15) increased. Cerebral embolization altered nitro-oxidative stress signaling and impaired the myocardial expression of ADRB1 (adrenoceptor β1) and cardioprotective Survivor Activating Factor Enhancement signaling pathways. Conclusions- Our findings indicate that stroke not only impairs cardiac contractility but also worsens myocardial vulnerability to ischemia. The underlying molecular mechanisms of stroke-induced myocardial alterations after cerebral embolization remain to be established, insofar as they may involve the sympathetic nervous system and nitro-oxidative stress.

Epigenetic Regulation of Metabolism and Inflammation by Calorie Restriction

Chronic caloric restriction (CR) without malnutrition is known to affect different cellular processes such as stem cell function, cell senescence, inflammation, and metabolism. Despite the differences in the implementation of CR, the reduction of calories produces a widespread beneficial effect in noncommunicable chronic diseases, which can be explained by improvements in immuno-metabolic adaptation. Cellular adaptation that occurs in response to dietary patterns can be explained by alterations in epigenetic mechanisms such as DNA methylation, histone modifications, and microRNA. In this review, we define these modifications and systematically summarize the current evidence related to CR and the epigenome. We then explain the significance of genome-wide epigenetic modifications in the context of disease development. Although substantial evidence exists for the widespread effect of CR on longevity, there is no consensus regarding the epigenetic regulations of the underlying cellular mechanisms that lead to improved health. We provide compelling evidence that CR produces long-lasting epigenetic effects that mediate expression of genes related to immuno-metabolic processes. Epigenetic reprogramming of the underlying chronic low-grade inflammation by CR can lead to immuno-metabolic adaptations that enhance quality of life, extend lifespan, and delay chronic disease onset.

Modelos experimentais de obesidade: análise crítica do perfil metabólico e da aplicabilidade

Introdução: a prevalência da obesidade e de outras doenças relacionadas está aumentando em todo o mundo de forma preocupante. Caracterizada pelo aumento do peso corporal ou do acúmulo excessivo de gordura corporal, a obesidade tem sido associada ao aumento da mortalidade decorrente de maior incidência de hipertensão, diabetes e vários tipos de câncer. Os modelos animais fornecem dados fundamentais para a compreensão dos parâmetros básicos que regulam os componentes do nosso balanço energético. Objetivo: esta revisão selecionou artigos que utilizaram modelos animais (ratos e camundongos) de obesidade focando nas principais alterações metabólicas causadas pela obesidade com o objetivo de apresentar os principais modelos utilizados nos últimos 5 anos. Material e Métodos: Foram realizadas duas buscas na base de dados PubMed utilizando as expressões: “obesity” AND “metabolism” AND “animal model” AND “mice” e “obesity” AND “metabolism” AND “animal model” AND “rat”, sendo selecionados os estudos considerados mais relevantes a partir dos critérios: descrição detalhada do modelo experimental e análise dos parâmetros metabólicos de interesse: peso, perfil lipídico e perfil glicêmico. Outras referências foram utilizadas para elucidar melhor os modelos encontrados e também aqueles que não foram citados, mas, que possuem importância no entendimento da evolução dos modelos animais de obesidade. Resultados: A espécie mais utilizada foi o camundongo, o sexo predominante foi o masculino, a faixa etária dos roedores variou de neonatos até 44 semanas e o período de acompanhamento chegou até 53 semanas. A obesidade foi confirmada pelo aumento significativo do peso e na maioria dos estudos foram encontradas alterações no metabolismo lipídico e glicêmico. Encontramos cinco grupos de mecanismos de indução da obesidade porém a maioria dos estudos utilizou dietas hiperlipídicas, modelo que mais se assemelha às alterações metabólicas encontradas em humanos. Conclusão: Investigar as causas e efeitos da obesidade induzida em modelos experimentais pode fornecer uma melhor compreensão da fisiopatologia da obesidade, e proporcionar novas opções de prevenção e tratamento.

High Fat Programming and Cardiovascular Disease

Programming is triggered through events during critical developmental phases that alter offspring health outcomes. High fat programming is defined as the maintenance on a high fat diet during fetal and/or early postnatal life that induces metabolic and physiological alterations that compromise health. The maternal nutritional status, including the dietary fatty acid composition, during gestation and/or lactation, are key determinants of fetal and postnatal development. A maternal high fat diet and obesity during gestation compromises the maternal metabolic state and, through high fat programming, presents an unfavorable intrauterine milieu for fetal growth and development thereby conferring adverse cardiac outcomes to offspring. Stressors on the heart, such as a maternal high fat diet and obesity, alter the expression of cardiac-specific factors that alter cardiac structure and function. The proper nutritional balance, including the fatty acid balance, particularly during developmental windows, are critical for maintaining cardiac structure, preserving cardiac function and enhancing the cardiac response to metabolic challenges.

Transient postnatal over nutrition induces long-term alterations in cardiac NLRP3-inflammasome pathway

BACKGROUND AND AIMS

The prevalence of obesity is increasing worldwide at an alarming rate. Altered early nutrition, in particular postnatal overfeeding (PNOF), is a risk factor for impaired cardiac function in adulthood. In the understanding of the initiation or progression of heart diseases, NLRP3 inflammasome and non-coding RNAs have been proposed as key players. In this context, the aim of this study was to decipher the role of NLRP3 inflammasome and its post transcriptional control by micro-RNAs in the regulation of cardiac metabolic function induced by PNOF in mice.

METHODS AND RESULTS

Based on a model of mice exposed to PNOF through litter size reduction, we observed increased cardiac protein expression levels of NLRP3 and ETS-1 associated with alterations in insulin signaling. Additionally, miR-193b levels were down-regulated in the adult hearts of overfed animals. In a cardiomyocyte cell line, transfection with miR-193b induced down-regulation of ETS-1 and NLRP3 and improved insulin signaling.

CONCLUSIONS

These findings suggest that the miR-193b could be involved in cardiac phenotypic changes observed in adulthood induced by PNOF likely through the regulation of ETS-1 and NLRP3 expression, and through this of insulin signaling.

At the heart of programming: the role of micro-RNAs

Epidemiological and experimental observations tend to prove that environment, lifestyle or nutritional challenges influence heart functions together with genetic factors. Furthermore, when occurring during sensitive windows of heart development, these environmental challenges can induce an 'altered programming' of heart development and shape the future heart disease risk. In the etiology of heart diseases driven by environmental challenges, epigenetics has been highlighted as an underlying mechanism, constituting a bridge between environment and heart health. In particular, micro-RNAs which are involved in each step of heart development and functions seem to play a crucial role in the unfavorable programming of heart diseases. This review describes the latest advances in micro-RNA research in heart diseases driven by early exposure to challenges and discusses the use of micro-RNAs as potential targets in the reversal of the pathophysiology.

Impact of diet restriction in the management of diabetes: evidences from preclinical studies

The inappropriate dietary habits lead to the onset of age-related pathologies which include diabetes and cardiovascular ailments. Dietary restriction and nutritional therapy play an important role in the prevention of these chronic ailments. Preclinical research provides a basis for the therapeutic exploration of new dietary interventions for the clinical trials to potentiate the scientific management of diabetes and its related complications which further help in translating these nutritional improvements from bench to bedside. Within the same context, numerous therapeutically proved preclinical dietary interventions like high-fiber diet, caloric restriction, soy isoflavone-containing diets, etc., have shown the promising results for the management of diabetes and the associated complications. The focus of the present review is to highlight the various preclinical evidences of diet restriction for the management of diabetes and which will be helpful for enlightening the new ideas of nutritional therapy for future research exploration. In addition, some potential approaches are also discussed which are associated with various nutritional interventions to combat progressive diabetes and the associated disorders. Graphical abstract ᅟ.

Transient postnatal overfeeding causes liver stress-induced premature senescence in adult mice

Unbalanced nutrition early in life is increasingly recognized as an important factor in the development of chronic, non-communicable diseases at adulthood, including metabolic diseases. We aimed to determine whether transient postnatal overfeeding (OF) leads to liver stress-induced premature senescence (SIPS) of hepatocytes in association with liver structure and hepatic function alterations. Litters sizes of male C57BL/6 mice were adjusted to 9 pups (normal feeding, NF) or reduced to 3 pups during the lactation period to induce transient postnatal OF. Compared to the NF group, seven-month-old adult mice transiently overfed during the postnatal period were overweight and developed glucose intolerance and insulin resistance. Their livers showed microsteatosis and fibrosis, while hepatic insulin signaling and glucose transporter protein expressions were altered. Increased hepatic oxidative stress (OS) was observed, with increased superoxide anion production, glucose-6-phosphate dehydrogenase protein expression, oxidative DNA damage and decreased levels of antioxidant defense markers, such as superoxide dismutase and catalase proteins. Hepatocyte senescence was characterized by increased p21^WAF, p53, Acp53, p16^INK4a and decreased pRb/Rb and Sirtuin-1 (SIRT-1) protein expression levels. Transient postnatal OF induces liver OS at adulthood, associated with hepatocyte SIPS and alterations in liver structure and hepatic functions, which could be mediated by a SIRT-1 deficiency.

Sequential Exposure to Obesogenic Factors in Females Rats: From Physiological Changes to Lipid Metabolism in Liver and Mesenteric Adipose Tissue

During their lifetime, females are subjected to different nutritional and hormonal factors that could increase the risk of obesity and associated comorbidities. From early postnatal periods until the postmenopausal phase, exposure to over nutrition, high-energy diet and oestrogen deficiency, are considered as significant obesity risk factors in women. In this study, we assessed how key transitional life events and exposure to different nutrition influence energy homeostasis in a rat model. Specifically, we assessed the sequential exposure to postnatal over nutrition, high-fat diet (HFD) after weaning, followed later by ovariectomy (OVX; as a model of menopause). Each obesity risk factor increased significantly body weight (BW) and adiposity, with additive effects after sequential exposure. Increased energy intake in both HFD and/or OVX groups, and decreased locomotor activity and energy expenditure after OVX can explain these metabolic changes. Our study also documents decreased lipogenic pathway in mesenteric adipose tissue after HFD and/or OVX, independent of previous postnatal programming, yet only HFD evoked this effect in liver. In addition, we report an increase in the expression of the hepatic PEPCK depending on previous metabolic status. Overall, our results identify the impact of different risk factors, which will help in understanding the development of obesity in females.