Maria do Carmo Franco

Long-Lasting Effects of Undernutrition

Undernutrition is one of the most important public health problems, affecting more than 900 million individuals around the World. It is responsible for the highest mortality rate in children and has long-lasting physiologic effects, including an increased susceptibility to fat accumulation mostly in the central region of the body, lower fat oxidation, lower resting and postprandial energy expenditure, insulin resistance in adulthood, hypertension, dyslipidaemia and a reduced capacity for manual work, among other impairments. Marked changes in the function of the autonomic nervous system have been described in undernourished experimental animals. Some of these effects seem to be epigenetic, passing on to the next generation. Undernutrition in children has been linked to poor mental development and school achievement as well as behavioural abnormalities. However, there is still a debate in the literature regarding whether some of these effects are permanent or reversible. Stunted children who had experienced catch-up growth had verbal vocabulary and quantitative test scores that did not differ from children who were not stunted. Children treated before 6 years of age in day-hospitals and who recovered in weight and height have normal body compositions, bone mineral densities and insulin production and sensitivity.

Implications of maternal nutrient restriction in transgenerational programming of hypertension and endothelial dysfunction across F1–F3 offspring

AIMS An extensive variety of prenatal insults are associated with an increased incidence of metabolic and cardiovascular disorders in adult life. We previously demonstrated that maternal global nutrient restriction during pregnancy leads to increased blood pressure and endothelial dysfunction in the adult offspring. This study aimed to assess whether prenatal exposure to nutritional insult has transgenerational effects in F2 and F3 offspring. MAIN METHODS For this, female Wistar rats were randomly divided into two groups on day 1 of pregnancy: a control group fed standard chow ad libitum and a restricted group fed 50% of the ad libitum intake throughout gestation. At delivery, all animals were fed a standard laboratory chow diet. At 11 weeks of age, one female and one male from each restricted litter were randomly selected and mated with rats from another restricted litters in order to generate the F2 offspring. The same procedure produced F3 generation. Similarly, the rats in the control group were bred for each generation. KEY FINDINGS Our findings show that the deleterious effects of maternal nutrient restriction to which the F0 mothers were exposed may not be limited to the male first generation. In fact, we found that elevated blood pressure, an impaired vasodilatory response to acetylcholine and alterations in NO production were all transferred to the subsequent males from F2 and F3 generations. SIGNIFICANCE Our data show that global nutrient restriction during pregnancy results in a specific phenotype that can be passed transgenerationally to a second and third generation.

Micronutrient prenatal supplementation prevents the development of hypertension and vascular endothelial damage induced by intrauterine malnutrition

AIMS The premise that intrauterine malnutrition plays an important role in the development of cardiovascular and renal diseases implies that these disorders can be programmed during fetal life. Here, we analyzed the hypothesis that supplementation with mixed antioxidant vitamins and essential mineral in early life could prevent later elevation of blood pressure and vascular and renal dysfunction associated with intrauterine malnutrition. MAIN METHODS For this, female Wistar rats were randomly divided into three groups on day 1 of pregnancy: control fed standard chow ad libitum; restricted group fed 50% of the ad libitum intake and a restricted plus micronutrient cocktail group treated daily with a combination of micronutrient (selenium, folate, vitamin C and vitamin E) by oral gavage. KEY FINDINGS In adult offspring, renal function and glomerular number were impaired by intrauterine malnutrition, and the prenatal micronutrient treatment did not prevent it. However, increased blood pressure and reduced endothelium-dependent vasodilation were prevented by the micronutrient prenatal treatment. Intrauterine malnutrition also led to reduced NO production associated with increased superoxide generation, and these parameters were fully normalized by this prenatal treatment. SIGNIFICANCE Our current findings indicate that programming alterations during fetal life can be prevented by interventions during the prenatal period, and that disturbance in availability of both antioxidant vitamins and mineral may play a crucial role in determining the occurrence of long-term cardiovascular injury.

Modification of Epigenetic Patterns in Low Birth Weight Children: Importance of Hypomethylation of the ACE Gene Promoter

There is a growing body of evidence that epigenetic alterations are involved in the pathological mechanisms of many chronic disorders linked to fetal programming. Angiotensin-converting enzyme (ACE) appears as one candidate gene that brings new insights into the epigenetic control and later development of diseases. In this view, we have postulated that epigenetic modifications in the ACE gene might show different interactions between birth weight (BW), blood pressure levels, plasma ACE activity and ACE I/D polymorphism. To explore this hypothesis, we performed a cross-sectional study to evaluate the DNA methylation of 3 CpG sites using pyrosequencing within the ACE gene promoter of peripheral blood leukocytes from 45 LBW children compared with 70 NBW children. Our results have revealed that LBW children have lower methylation levels (P<0.001) in parallel with a higher ACE activity (P = 0.001). Adjusting for prematurity, gender, age, body mass index, and family history of cardiovascular disease did not alter these findings. We have also performed analyses of individual CpG sites. The frequency of DNA methylation was significantly different at two CpG sites (site 1: nucleotide position +555; and site 3: nucleotide position +563). In addition, we have found a significant inverse correlation between degree of DNA methylation and both ACE activity (P<0.001) and systolic blood pressure levels (P<0.001). We also observed that the methylation level was significantly lower in LBW children who are carriers of the DD genotype compared to NBW children with DD genotype (P<0.024). In conclusion, we are able to demonstrate that the hypomethylation in the 3 CpG sites of ACE gene promoter is associated with LBW in 6 to 12 year-old children. The magnitude of these epigenetic changes appears to be clinically important, which is supported by the observation that discrete changes in DNA methylation can affect systolic blood pressure and ACE protein activity levels.

Influence of Aerobic Training on the Reduced Vasoconstriction to Angiotensin II in Rats Exposed to Intrauterine Growth Restriction: Possible Role of Oxidative Stress and AT2 Receptor of Angiotensin II

Intrauterine growth restriction (IUGR) is associated with impaired vascular function, which contributes to the increased incidence of chronic disease. The aim of this study was to investigate whether aerobic training improves AngII-induced vasoconstriction in IUGR rats. Moreover, we assess the role of superoxide dismutase (SOD) isoforms and NADPH oxidase-derived superoxide anions in this improvement. Female Wistar rats were randomly divided into two groups on day 1 of pregnancy. A control group was fed standard chow ad libitum, and a restricted group was fed 50% of the ad libitum intake throughout gestation. At 8 weeks of age, male offspring from both groups were randomly assigned to 4 experimental groups: sedentary control (SC), trained control (TC), sedentary restricted (SRT), and trained restricted (TRT). The training protocol was performed on a treadmill and consisted of a continuous 60-min session 5 days/week for 10 weeks. Following aerobic training, concentration–response curves to AngII were obtained in endothelium-intact aortic rings. Protein expression of SOD isoforms, AngII receptors and the NADPH oxidase component p47phox was assessed by Western blot analysis. The dihydroethidium was used to evaluate the in situ superoxide levels under basal conditions or in the presence of apocynin, losartan or PD 123,319. Our results indicate that aerobic training can prevent IUGR-associated increases in AngII-dependent vasoconstriction and can restore basal superoxide levels in the aortic rings of TRT rats. Moreover, we observed that aerobic training normalized the increased p47phox protein expression and increased MnSOD and AT2 receptor protein expression in thoracic aortas of SRT rats. In summary, aerobic training can result in an upregulation of antioxidant defense by improved of MnSOD expression and attenuation of NADPH oxidase component p47phox. These effects are accompanied by increased expression of AT2 receptor, which provide positive effects against Ang II–induced superoxide generation, resulting in attenuation of AngII-induced vasoconstriction.

Body mass index, adipokines and insulin resistance in asthmatic children and adolescents

Abstract Objective: This study aimed to describe the body mass index, insulin resistance, levels of adipokines and inflammatory markers in Brazilian asthmatic children and adolescents and to investigate their possible association with the severity and control of asthma. Methods: Cross-sectional study (n = 92; age: 3–18 years). Assessed data: Body weight and height, used to calculate the body mass index (BMIZ) and height-for-age (HAZ). Laboratory measurements: Lipid profile; glycemia and insulin for homeostasis model assessment (HOMA); adipokines; tumor necrosis factor alpha (TNF-α), C-reactive protein (CRP) and monocyte chemoattractant protein-1 (MCP-1); total immunoglobulin E (IgE) and specific IgE against aeroallergens. Results: The median age was 9.6 years (3.0–16.6); most participants were male (n = 52, 56.5%), pre-pubertal (n = 54, 58.6%) and had atopic asthma (n = 85, 92.4%). Overweight/obesity (38%) showed an inverse correlation with age (adjusted odds ratio [OR] = 0.781; 95% confidence interval [CI] 0.66–0.92) and a direct correlation with the leptin concentration (adjusted OR = 1.13; 95% CI 1.04–1.22). Insulin concentration was independently associated with moderated persistent asthma (adjusted OR = 1.31; 95% CI 1.09–1.52). HOMA showed a direct correlation with the leptin (β = 0.475; 95% CI 0.117–0.268) and total IgE (β = 0.197; 95% CI 0.002–0.096) levels and an inverse correlation with the TNF-α levels (β = −0.255; 95% CI;−0.366–0.055). Conclusions: Asthma was associated with insulin resistance and a systemic inflammatory response possibly mediated by adipokines, with leptin levels standing out among the participants with excess weight.

Impact of nutritional recovery with linear growth on the concentrations of adipokines in undernourished children living in Brazilian slums

Undernutrition in early life has been reported to be closely associated with the development of non-communicable diseases in adulthood. Adequate treatment is important for reversing these effects. In the present study, we investigated the effects of undernutrition and anthropometric recovery on the weights and heights of children in relation to the concentrations of leptin, adiponectin and plasminogen activator inhibitor-1 (PAI-1). A total of 119 children (aged 6-16 years) from the slums of São Paulo were selected according to their nutritional status and divided into three groups as follows: control (healthy without intervention, n 38) with a height-for-age Z score (HAZ) and a BMI-for-age Z score (BAZ) > -1·6; undernourished (HAZ and/or BAZ < -1·6, n 54); recovered from undernutrition (after treatment in a rehabilitation centre; HAZ and BAZ > -1·6, n 27). Blood samples were collected to determine insulin, glucose, leptin, adiponectin and PAI-1 concentrations. Leptin concentrations in the undernourished group were lower than those in the control and recovered groups (mean 0·92 (95% CI 0·67, 1·25), 2·03 (95% CI 1·46, 2·82) and 1·66 (95% CI 1·15, 2·44) ng/ml, P=0·003), which had similar leptin concentrations. There were no differences in adiponectin and PAI-1 concentrations among the groups. A positive correlation between waist circumference and leptin concentrations was observed in all the girls and boys of the control group (control: r 0·729, P<0·01; undernourished: r 0·490, P<0·05; and recovered: r 0·829, P<0·01; r 0·673, P<0·05). Stronger correlations between leptin and insulin concentrations were observed in the recovered group. The results of the present study indicate that normal leptin concentrations are found when normal height and weight are achieved.

The antioxidant effects of green tea reduces blood pressure and sympathoexcitation in an experimental model of hypertension

Background: Oxidative stress is a key mediator in the maintenance of sympathoexcitation and hypertension in human and experimental models. Green tea is widely known to be potent antioxidant. Objective: We aimed to evaluate the effects of green tea in a model of hypertension. Methods: Hypertension was induced by the nitric oxide synthase inhibitor [N-nitro-L-arginine-methyl-ester (L-NAME); 20 mg/kg per day, orally, for 2 weeks] in male Wistar rats. After the first week of L-NAME treatment, animals received green tea ad libitum for 1 week. At the end of the treatment period, blood pressure, heart rate, baroreflex sensitivity, renal sympathetic nerve activity, and vascular and systemic oxidative stress were assessed. Results: L-NAME-treated animals exhibited an increase in blood pressure (165 ± 2 mmHg) compared with control rats (103 ± 1 mmHg) and green tea treatment reduced hypertension (119 ± 1 mmHg). Hypertensive animals showed a higher renal sympathetic nerve activity (161 ± 12 spikes/s) than the control group (97 ± 2 spikes/s), and green tea also decreased this parameter in the hypertensive treated group (125 ± 5 spikes/s). Arterial baroreceptor function and vascular and systemic oxidative stress were improved in hypertensive rats after green tea treatment. Conclusions: Taken together, short-term green tea treatment improved cardiovascular function in a hypertension model characterized by sympathoexcitation, which may be because of its antioxidant properties.

Cystatin C and renal function in pediatric kidney transplant recipients

In clinical practice, the glomerular filtration rate (GFR) is often determined with serum creatinine. However, studies have shown cystatin C to be a better parameter for the diagnosis of impaired renal function. We compared GFR estimated by plasma cystatin C with GFR estimated by serum creatinine in a sample of 50 pediatric renal transplant recipients and 24 healthy children. The correlation between GFR estimated by serum creatinine and by cystatin C was significant (r = 0.75; P < 0.001, Persons correlation); however, in pediatric kidney transplant recipients, the GFR was 6.7 mL/min lower when determined using cystatin C rather than serum creatinine. Moreover, using GFR estimated by cystatin C we found that 42% of the pediatric kidney transplant recipients had an estimated GFR <60 mL.min-1.1.73 (m(2))-1, whereas when GFR was estimated by the serum creatinine formula only 16% of the children had values below this cutoff point indicative of chronic kidney disease (P < 0.001). We conclude that, in pediatric kidney transplant recipients, estimation of GFR yields lower values when cystatin C is used rather than serum creatinine.

Resistance Training in Spontaneously Hypertensive Rats with Severe Hypertension

Background Resistance training (RT) has been recommended as a non-pharmacological treatment for moderate hypertension. In spite of the important role of exercise intensity on training prescription, there is still no data regarding the effects of RT intensity on severe hypertension (SH). Objective This study examined the effects of two RT protocols (vertical ladder climbing), performed at different overloads of maximal weight carried (MWC), on blood pressure (BP) and muscle strength of spontaneously hypertensive rats (SHR) with SH. Methods Fifteen male SHR [206 ± 10 mmHg of systolic BP (SBP)] and five Wistar Kyoto rats (WKY; 119 ± 10 mmHg of SBP) were divided into 4 groups: sedentary (SED-WKY) and SHR (SED-SHR); RT1-SHR training relative to body weight (~40% of MWC); and RT2-SHR training relative to MWC test (~70% of MWC). Systolic BP and heart rate (HR) were measured weekly using the tail-cuff method. The progression of muscle strength was determined once every fifteen days. The RT consisted of 3 weekly sessions on non-consecutive days for 12-weeks. Results Both RT protocols prevented the increase in SBP (delta - 5 and -7 mmHg, respectively; p > 0.05), whereas SBP of the SED-SHR group increased by 19 mmHg (p < 0.05). There was a decrease in HR only for the RT1 group (p < 0.05). There was a higher increase in strength in the RT2 (140%; p < 0.05) group as compared with RT1 (11%; p > 0.05). Conclusions Our data indicated that both RT protocols were effective in preventing chronic elevation of SBP in SH. Additionally, a higher RT overload induced a greater increase in muscle strength.