The association between modifiable lifestyle behaviour in Latin-American schoolchildren with abdominal obesity and excess weight. A comparison of Chile and Colombia.

OBJECTIVE: The purpose was to determine the association of lifestyle (i.e., Mediterranean diet [MD] adherence, physical activity [PA], screen time [ST]) and fitness with abdominal obesity (AO) and excess weight in the Chilean and Colombian schoolchildren. RESEARCH METHODS & PROCEDURES: This cross-sectional study included 969 schoolchildren, girls (n=441, 5.24±0.80 years old) and boys (n=528, 5.10±0.78 years old) from Chile (n=611) and Colombia (n=358). The body mass index (BMI), waist circumference (WC), waist-to-height ratio (WtHR), MD adherence, PA, ST and cardiorespiratory fitness (CRF) were evaluated. The association of AO and anthropometric variables with lifestyle was estimated through multiple linear regression. To determine the association between AO and lifestyle, a logistic regression and the inclusion of odds ratios (ORs) with 95% confidence intervals (CIs) were used. RESULTS: Worse CRF in Chilean children were positively correlated with WC. Excess weight in Chilean and Colombian children was positively associated with an unhealthy lifestyle. In Chilean children unhealthy lifestyle was also associated with AO based on WC≥85th percentile and AO based on WtHR≥85th percentile. In Chilean children, excess weight (BMI≥85th percentile) was positively associated with poor MD adherence. CONCLUSION: AO and excess weight were associated with an unhealthy lifestyle in Latin-American schoolchildren. Interventions to reduce the prevalence of AO should include promoting healthier lifestyle choices (i.e., increasing PA after school, reducing ST and improving CRF).

Cortical diurnal rhythms remain intact with microglial depletion.

Microglia are subject to change in tandem with the endogenously generated biological oscillations known as our circadian rhythm. Studies have shown microglia harbor an intrinsic molecular clock which regulates diurnal changes in morphology and influences inflammatory responses. In the adult brain, microglia play an important role in the regulation of condensed extracellular matrix structures called perineuronal nets (PNNs), and it has been suggested that PNNs are also regulated in a circadian and diurnal manner. We sought to determine whether microglia mediate the diurnal regulation of PNNs via CSF1R inhibitor dependent microglial depletion in C57BL/6J mice, and how the absence of microglia might affect cortical diurnal gene expression rhythms. While we observe diurnal differences in microglial morphology, where microglia are most ramified at the onset of the dark phase, we do not find diurnal differences in PNN intensity. However, PNN intensity increases across many brain regions in the absence of microglia, supporting a role for microglia in the regulation of PNNs. Here, we also show that cortical diurnal gene expression rhythms are intact, with no cycling gene changes without microglia. These findings demonstrate a role for microglia in the maintenance of PNNs, but not in the maintenance of diurnal rhythms.

The social and psychological health of children is associated with Mediterranean diet adherence items, cardiorespiratory fitness, and lifestyle.

INTRODUCTION: Background: Mediterranean diet (MD) adherence, physical activity (PA) patterns, and physical fitness are associated with physical, social, and psychological health in children. Objective: the purpose of this study was to determine the association of items of MD adherence, fitness components, and lifestyle with psychological and social health in Chilean schoolchildren. Material and methods: this cross-sectional study included 615 schoolchildren, both girls (n = 271, 11.7 ± 1.00 years old) and boys (n = 344, 11.8 ± 1.1 years old). Anthropometric parameters, fitness components, lifestyle, health-related quality of life (HRQoL), and self-esteem were measured. Results: HRQoL showed an association with cardiorespiratory fitness (ß: 0.12, p < 0.001) and PA (ß: 0.32, p = 0.023). Self-esteem was inversely associated with screen time (ß: -1.35, p < 0.001). Moreover, social health presented a positive association with PA after school (ß: 0.06, p = 0.037). In relation to MD adherence items, HRQoL was linked to the items "Takes a fruit or fruit juice every day" (ß: 1.93, p = 0.004) and "Consumes fresh or cooked vegetables ˃ 1 time/day" (ß: 1.12, p = 0.018). Self-esteem was associated to "Consumes a dairy product ˃ 1 time/day" (ß: 3.30, p = 0.030). Social health was inversely related to "Eats at a fast food restaurant ≥ 1 time/week" (ß: -0.26, p = 0.003) and positively to "Consumes pasta or rice almost every day" (ß: 0.35, p = 0.049). Conclusion: MD adherence items, fitness, and lifestyle were linked to psychological and social health, therefore it is necessary to develop preventive strategies for schoolchildren to change in a positive way these modifiable lifestyle behaviors.

INTRODUCCIÓN: Antecedentes: la adherencia a la dieta mediterránea (DM), los patrones de actividad física (AF) y la condición física están asociados a la salud física, social y psicológica de los niños. Objetivo: el propósito de este estudio fue determinar la asociación entre ítems de adherencia a la DM, componentes de la condición física y el estilo de vida con la salud psicológica y social de los escolares chilenos. Material y métodos: este estudio transversal incluyó a 615 escolares, niñas (n = 271, 11,7 ± 1,00 años) y niños (n = 344, 11,8 ± 1,1 años). Se midieron parámetros antropométricos, componentes de la condición física, estilo de vida, calidad de vida relacionada con la salud (CVRS) y autoestima. Resultados: la CVRS mostró asociación con la capacidad cardiorrespiratoria (ß: 0,12, p < 0,001) y la PA (ß: 0,32, p = 0,023). La autoestima, por su parte, se relacionó de manera inversa con el tiempo frente a la pantalla (ß: -1,35, p < 0,001). Además, la salud social presentó una asociación positiva con la AF después de la escuela (ß: 0,06, p = 0,037). En relación a los ítems de adherencia a la DM, la CVRS se vinculó a los ítems "Toma una fruta o jugo de fruta todos los días" (ß: 1,93, p = 0,004) y "Consume verduras frescas o cocidas ˃ 1 vez/día" (ß: 1,12, p = 0,018). La autoestima se asoció a "Consume un producto lácteo ˃ 1 vez/día" (ß: 3,30, p = 0,030). La salud social se vinculó inversamente con "Come en un restaurante de comida rápida ≥ 1 vez/semana" (ß: -0,26, p = 0,003) y positivamente con "Consume pasta o arroz casi todos los días" (ß: 0,35, p = 0,049). Conclusión: los ítems de adherencia a la DM, la condición física y el estilo de vida se relacionaron con la salud psicológica y social de los escolares, por lo que es necesario desarrollar estrategias preventivas para modificar de manera positiva estas conductas de estilo de vida modificables.

The association between modifiable lifestyle behaviour in Latin-American schoolchildren with abdominal obesity and excess weight. A comparison of Chile and Colombia.

OBJECTIVE: The purpose was to determine the association of lifestyle (i.e., Mediterranean diet [MD] adherence, physical activity [PA], screen time [ST]) and fitness with abdominal obesity (AO) and excess weight in the Chilean and Colombian schoolchildren. RESEARCH METHODS & PROCEDURES: This cross-sectional study included 969 schoolchildren, girls (n=441, 5.24±0.80 years old) and boys (n=528, 5.10±0.78 years old) from Chile (n=611) and Colombia (n=358). The body mass index (BMI), waist circumference (WC), waist-to-height ratio (WtHR), MD adherence, PA, ST and cardiorespiratory fitness (CRF) were evaluated. The association of AO and anthropometric variables with lifestyle was estimated through multiple linear regression. To determine the association between AO and lifestyle, a logistic regression and the inclusion of odds ratios (ORs) with 95% confidence intervals (CIs) were used. RESULTS: Worse CRF in Chilean children were positively correlated with WC. Excess weight in Chilean and Colombian children was positively associated with an unhealthy lifestyle. In Chilean children unhealthy lifestyle was also associated with AO based on WC≥85th percentile and AO based on WtHR≥85th percentile. In Chilean children, excess weight (BMI≥85th percentile) was positively associated with poor MD adherence. CONCLUSION: AO and excess weight were associated with an unhealthy lifestyle in Latin-American schoolchildren. Interventions to reduce the prevalence of AO should include promoting healthier lifestyle choices (i.e., increasing PA after school, reducing ST and improving CRF).

Microglia facilitate loss of perineuronal nets in the Alzheimer's disease brain.

BACKGROUND: Microglia, the brain's principal immune cell, are increasingly implicated in Alzheimer's disease (AD), but the molecular interfaces through which these cells contribute to amyloid beta (Aß)-related neurodegeneration are unclear. We recently identified microglial contributions to the homeostatic and disease-associated modulation of perineuronal nets (PNNs), extracellular matrix structures that enwrap and stabilize neuronal synapses, but whether PNNs are altered in AD remains controversial. METHODS: Extensive histological analysis was performed on male and female 5xFAD mice at 4, 8, 12, and 18 months of age to assess plaque burden, microgliosis, and PNNs. Findings were validated in postmortem AD tissue. The role of neuroinflammation in PNN loss was investigated via LPS treatment, and the ability to prevent or rescue disease-related reductions in PNNs was assessed by treating 5xFAD and 3xTg-AD model mice with colony-stimulating factor 1 receptor (CSF1R) inhibitor PLX5622 to deplete microglia. FINDINGS: Utilizing the 5xFAD mouse model and human cortical tissue, we report that PNNs are extensively lost in AD in proportion to plaque burden. Activated microglia closely associate with and engulf damaged nets in the 5xFAD brain, and inclusions of PNN material are evident in mouse and human microglia, while aggrecan, a critical PNN component, deposits within human dense-core plaques. Disease-associated reductions in parvalbumin (PV)+ interneurons, frequently coated by PNNs, are preceded by PNN coverage and integrity impairments, and similar phenotypes are elicited in wild-type mice following microglial activation with LPS. Chronic pharmacological depletion of microglia prevents 5xFAD PNN loss, with similar results observed following depletion in aged 3xTg-AD mice, and this occurs despite plaque persistence. INTERPRETATION: We conclude that phenotypically altered microglia facilitate plaque-dependent PNN loss in the AD brain. FUNDING: The NIH (NIA, NINDS) and the Alzheimer's Association.

Lifestyle associated with physical fitness related to health and cardiometabolic risk factors in Chilean schoolchildren.

BACKGROUND: Excessive screen time (ST) and lower physical activity (PA) patterns have been reported to have an impact on cardiometabolic risk (CMR); however, their impact on physical fitness needs in-depth study. OBJECTIVE: To determine the association between lifestyle (i.e. ST and PA after school) with physical fitness related to health and CMR (i.e. abdominal obesity and hypertension) in Chilean schoolchildren. METHODS: The sample for this cross-sectional study comprised 263 girls (11.87±0.83 years) and 319 boys (12.02±0.88 years). The body mass index (BMI), waist circumference (WC), waist to height ratio (WtHR), CMR (WtHR≥0.5), body fat (BF), systolic (SBP) and diastolic blood pressure (DBP), physical fitness, ST (h/day), and PA after school (h/week) were evaluated. RESULTS: Schoolchildren with good lifestyle had a lower BMI, WC, and WtHR (P<0.001) as well as a better VO2max (P<0.001) and standing long jump test (SLJ) (P=0.002). The schoolchildren with bad lifestyle had the highest proportion of students with abdominal obesity (WtHR≥0.5) (30.6%, P=0.009) and hypertension. (40.9%, P<0.001). Likewise, PA after school (ß; -0.02, P=0.002) and cardiorespiratory fitness (ß; -0.02, P=0.002) adjusted by age and sex reported inverse associations with abdominal obesity (WtHR≥0.5). Likewise, ST presented a positive association with SBP (ß; 0.14, P=0.030). Moreover, handgrip strength (ß; -0.17, P=0.010) and SLJ (ß; -0.05, P=0.023) reported inverse associations with SBP. CONCLUSION: In schoolchildren, a bad lifestyle was associated with low physical fitness related to health and CMR (i.e. abdominal obesity and hypertension).

EGFR is required for Wnt9a-Fzd9b signalling specificity in haematopoietic stem cells.

Wnt signalling drives many processes in development, homeostasis and disease; however, the role and mechanism of individual ligand-receptor (Wnt-Frizzled (Fzd)) interactions in specific biological processes remain poorly understood. Wnt9a is specifically required for the amplification of blood progenitor cells during development. Using genetic studies in zebrafish and human embryonic stem cells, paired with in vitro cell biology and biochemistry, we determined that Wnt9a signals specifically through Fzd9b to elicit ß-catenin-dependent Wnt signalling that regulates haematopoietic stem and progenitor cell emergence. We demonstrate that the epidermal growth factor receptor (EGFR) is required as a cofactor for Wnt9a-Fzd9b signalling. EGFR-mediated phosphorylation of one tyrosine residue on the Fzd9b intracellular tail in response to Wnt9a promotes internalization of the Wnt9a-Fzd9b-LRP signalosome and subsequent signal transduction. These findings provide mechanistic insights for specific Wnt-Fzd signals, which will be crucial for specific therapeutic targeting and regenerative medicine.