Epicardial slices: an innovative 3D organotypic model to study epicardial cell physiology and activation.

The epicardium constitutes an untapped reservoir for cardiac regeneration. Upon heart injury, the adult epicardium re-activates, leading to epithelial-to-mesenchymal transition (EMT), migration, and differentiation. While interesting mechanistic and therapeutic findings arose from lower vertebrates and rodent models, the introduction of an experimental system representative of large mammals would undoubtedly facilitate translational advancements. Here, we apply innovative protocols to obtain living 3D organotypic epicardial slices from porcine hearts, encompassing the epicardial/myocardial interface. In culture, our slices preserve the in vivo architecture and functionality, presenting a continuous epicardium overlaying a healthy and connected myocardium. Upon thymosin ß4 treatment of the slices, the epicardial cells become activated, upregulating epicardial and EMT genes, resulting in epicardial cell mobilization and differentiation into epicardial-derived mesenchymal cells. Our 3D organotypic model enables to investigate the reparative potential of the adult epicardium, offering an advanced tool to explore ex vivo the complex 3D interactions occurring within the native heart environment.

Ultra-processed food consumption and its effects on anthropometric and glucose profile: A longitudinal study during childhood.

BACKGROUND AND AIMS: Obesity and insulin resistance development are related to known risk factors (such as diet) that begin in childhood. Among dietary factors, the consumption of ultra-processed foods has received attention. The present study investigated the association between ultra-processed foods consumption at preschool age and changes in anthropometric measurements from preschool to school age and glucose profile at school age. METHODS AND RESULTS: The present study was a follow-up of a randomized controlled trial, conducted with 307 children of low socioeconomic status from São Leopoldo, Brazil. At ages 4 and 8 years, children's anthropometric assessments were collected from preschool to school age including body-mass index (BMI) for-age, waist circumference (WC), waist-to-height ratio (WHtR) and skinfold. At the age 8 years, blood tests were performed to measure glucose profile. Dietary data were collected through 24-h recalls and the children's ultra-processed food intake was assessed. Linear regression analysis was used to assess the relationship between ultra-processed food consumption and the outcomes. The percentage of daily energy provided by ultra-processed foods was 41.8 ± 8.7 (753.8 ± 191.0 kcal) at preschool age and 47.8 ± 8.9 (753.8 ± 191.0 kcal) at school age, on average. The adjusted linear regression analyses showed that ultra-processed food consumption at preschool age was a predictor of an increase in delta WC from preschool to school age (ß = 0.07; 95%CI 0.01-0.14; P = 0.030), but not for glucose metabolism. CONCLUSION: Our data suggest that early ultra-processed food consumption played a role in increasing abdominal obesity in children. These results reinforce the importance of effective strategies to prevent the excessive consumption of ultra-processed foods, especially in early ages.

Validation of obesity susceptibility loci identified by genome-wide association studies in early childhood in South Brazilian children.

BACKGROUND: The prevalence of childhood obesity has been dramatically increasing in developing countries as it has been reported for developed nations. Identifying susceptibility genes in early life could provide the foundations for interventions in lifestyle to prevent obese children to become obese adults. OBJECTIVES: The objective of this study was to evaluate the influence of genetic variants related to obesity identified by genome-wide association studies (MC4R, TMEM18, KCTD15, SH2B1, SEC16B, BDNF, NEGR1, OLFM4 and HOXB5 genes) on anthropometric and dietary phenotypes in two Brazilian cohorts followed-up since birth. METHODS: There were 745 children examined at birth, after 1 year and after 3.5 years of follow-up. Ten single nucleotide polymorphisms were genotyped. Anthropometric and dietary parameters were compared among genotypes. Children were classified as overweight when body mass index Z-score was >+1. RESULTS: Overweight prevalence was 30.7% at 3.5 years old. Significant associations were identified at 3.5 years old for TMEM18 rs6548238, NEGR1 rs2815752, BDNF rs10767664 and rs6265 (1 year old and 3.5 years old) with anthropometric phenotypes and at 3.5 years old for SEC16B rs10913469 with dietary parameters. CONCLUSIONS: Our results indicate that genetic variants in/near these genes contribute to obesity susceptibility in childhood and highlight the age at which they begin to affect obesity-related phenotypes.

Consumption of ultra-processed food products and its effects on children's lipid profiles: a longitudinal study.

BACKGROUND AND AIMS: Cardiovascular disease development is related to known risk factors (such as diet and blood lipids) that begin in childhood. Among dietary factors, the consumption of ultra-processing products has received attention. This study investigated whether children's consumption of processed and ultra-processing products at preschool age predicted an increase in lipid concentrations from preschool to school age. METHODS AND RESULTS: Cohort study conducted with 345 children of low socioeconomic status from São Leopoldo, Brazil, aged 3-4 years and 7-8 years. Blood tests were done to measure lipid profile. Dietary data were collected through 24-h recalls and the children's processed and ultra-processing product intake was assessed. Linear regression analysis was used to assess the relationship between processed and ultra-processed product intake at 3-4 years on changes in lipid concentrations from preschool to school age. The percentage of daily energy provided by processed and ultra-processed products was 42.6 ± 8.5 at preschool age and 49.2 ± 9.5 at school age, on average. In terms of energy intake, the main products consumed were breads, savoury snacks, cookies, candy and other sweets in both age groups. Ultra-processed product consumption at preschool age was a predictor of a higher increase in total cholesterol (ß = 0.430; P = 0.046) and LDL cholesterol (ß = 0.369; P = 0.047) from preschool to school age. CONCLUSION: Our data suggest that early ultra-processed product consumption played a role in altering lipoprotein profiles in children from a low-income community in Brazil. These results are important to understanding the role of food processing and the early dietary determinants of cardiovascular disease.

Role of human tissue kallikrein in gastrointestinal stromal tumour invasion.

BACKGROUND: Human tissue kallikrein (hK1) generates vasodilator kinins from kininogen and promotes angiogenesis by kinin-dependent and kinin-independent mechanisms. Here, we investigate the expression and functional relevance of hK1 in human gastrointestinal stromal tumour (GIST). METHODS: Vascularisation and hK1 expression of GIST samples were assessed by immunohistochemistry. In two GIST cell lines, hK1 expression was assessed by PCR, and hK1 protein levels and activity were measured by ELISA and an amidolytic assay, respectively. The effect of hK1 silencing, inhibition or overexpression on GIST cell proliferation, migration and paracrine induction of angiogenesis was studied. Finally, local and systemic levels of hK1 were assessed in mice injected with GIST cells. RESULTS: Human tissue kallikrein was detected in 19 out of 22 human GIST samples. Moreover, GIST cells express and secrete active hK1. Titration of hK1 demonstrated its involvement in GIST invasive behaviour, but not proliferation. Furthermore, hK1 released by GIST cells promoted endothelial cell migration and network formation through kinin-dependent mechanisms. Gastrointestinal stromal tumour implantation in nude mice resulted in local and systemic hK1 expression proportional to tumour dimension. CONCLUSIONS: Human tissue kallikrein is produced and released by GIST and participates in tumour invasion. Further studies are needed to validate hK1 as a diagnostic biomarker and therapeutic target in GIST.

Prevalence of overweight and associated factors in southern Brazilian adolescents.

OBJECTIVE: The aim of this study was to determine the prevalence of overweight in adolescents in a southern Brazilian city, and ascertain gender differences and association with socio-economic and demographic conditions, family factors and individual behaviours. METHODS: Cross-sectional population-based study with random cluster sampling of households, including 722 adolescents (10-19 years), from a city in southern Brazil. Body mass index (BMI) was calculated based on the National Center for Health and Statistics reference curve, defining overweight as BMI 85th percentile. RESULTS: Prevalence of overweight was 17% in girls and 19% in boys. In multivariate Poisson regression, chronic illness in parent(s) and household of up to four people were associated with overweight in boys, whereas low fibre intake, more hours spent watching television and regular exercise were associated with overweight in girls. CONCLUSION: The prevalence of overweight in Brazilian adolescents is high, with gender differences in associated factors. Health workers in schools and public health services should be aware of these differences in order to improve preventive and therapeutic strategies in this age group.