Paula Helena Ortiz Lima

Purpose: Cardiovascular fitness (maximal oxygen uptake [VO2max]) is linked with health indicators and the α2 subunit of the AMP-activated protein kinase (AMPKα2), encoded by the PRKAA2 gene, is an important metabolic sensor and can mediate part of exercise effect. It has been proposed that changes in the metabolic process bound with exercise might occur through epigenetic regulations. However, how VO2max can influence the epigenetic mechanism and consequently health is still unknown. The aim of this study was to investigate the PRKAA2 gene methylation profile and its relation to metabolic variables in normoglycemic monozygotic twins discordant for VO2max.Methods: Nine pairs of monozygotic twins were studied, with the intra-pair VO2max difference >10 ml • kg–1 • min–1. An oral glucose tolerance test was used, and blood samples were collected for biochemical and DNA methylation analyses.Results: No DNA methylation differences were observed between the groups. The low-cardiorespiratory-fitness group demonstrated a positive correlation between the methylation profile and low-density lipoprotein (CpG1, r = 0.714) and total cholesterol (CpG1, r = 0.723; CpG3, r = 0.678). Only the high-cardiorespiratory-fitness group showed correlations between glucose and insulin variables.Conclusions: Our data suggest a link between high cardiorespiratory fitness and glucose-insulin correlation. The results provide important insights for future studies about the mechanisms through which VO2max can influence glucose metabolism.

Studies have pointed out a higher mortality after coronary artery bypass surgery (CABG) in patients with stent. To evaluate inflammatory markers in peripheral blood cells and in coronary artery tissue samples obtained during CABG in patients with stent compared to controls. The case series consisted of two groups, one with previous stent implantation (n = 41) and one control (n = 26). The expression of the LIGHT, IL-6, ICAM, VCAM, CD40, NFKB, TNF, IFNG genes was analyzed in peripheral blood cells collected preoperatively. The coronary artery was evaluated for: interleukin-6, ICAM, VCAM, CD40, NFKB, TNF-alpha and IFN-gamma by immunohistochemistry. A total of 176 tissue samples were grouped for analysis in: A1- arteries with stent (n = 38); A2- native arteries from patients with stent in another artery (n = 68); and A3- arteries without stent from controls undergoing routinely CABG surgery (n = 70). A significance level of 0.05 was adopted. Patients with stent showed higher TNF (p = 0.03) and lower CD40 gene expression (p = 0.01) in peripheral blood cells than controls without stent. In coronary artery samples, the TNF-alpha protein staining was higher in the group A1, not only in the intima-media layer (5.16 ± 5.05 vs 1.90 ± 2.27; p = 0.02), but also in the adipose tissue (6.69 ± 3.87 vs 2.27 ± 4.00; p < 0.001). Furthermore, group A1 had a higher interleukin-6 protein staining in adipose tissue than group A3 (p = 0.04). We observed a persistently higher systemic TNF expression associated with exacerbated TNF-alpha and interleukin-6 local production in patients with stents. This finding may contribute to a worse clinical outcome.

Pregnant women with mild gestational hyperglycemia present a high risk for hypertension and obesity, and appear to reproduce the model of metabolic syndrome in pregnancy, including hyperinsulinemia and insulin resistance. Diabetic patients have a higher frequency of the IRS-1 Gly972Arg variant and this polymorphism is directly related to insulin resistance and subsequent hyperglycemia. In diabetes, hyperglycemia and other associated factors generate reactive oxygen species that increase DNA damage. The aims of this study were to evaluate the presence of the IRS-1 Arg972 polymorphism in pregnant women with diabetes or mild gestational hyperglycemia, and in their newborns. Additionally, we evaluated the level of primary DNA damage in lymphocytes of Brazilian pregnant women and the relationship between the amount of genetic damage and presence of the polymorphism. A based on the oral glucose tolerance test (OGTT) results and on glycemic profiles (GP), as follows: non-diabetic group, mild gestational hyperglycemia (MGH) and diabetic group. Eighty-five newborns were included in the study. Maternal peripheral blood samples and umbilical cord blood samples (5–10 mL) were collected for genotyping by PCR-RFLP and for comet assays. The prevalence of genotype Gly/Arg in pregnant women groups was not statistically significant. In newborns, the frequency of Gly/Arg was significantly higher in the MGH and diabetic groups than in the non-diabetic group. Taken together, groups IIA and IIB (IIA + IIB; diabetes) presented lower amounts of DNA damage than the non-diabetic group (p = 0.064). No significant association was detected between genetic damage and the presence of the Arg972 genotype in pregnant women. The polymorphism was more prevalent in newborns of diabetic and MGH women. We believe that it is necessary to increase the number of subjects to be examined in order to better determine the biological role of the Arg972 polymorphism in these patients. Despite being classified as low-risk, pregnant women with mild gestational hyperglycemia characterize a population of maternal and perinatal adverse outcomes, and that, together with their newborns, require better monitoring by professionals and health services.

Pregnant women with mild gestational hyperglycemia present high risk for hypertension, obesity and hyperglycemia, and appeared to reproduce the model of metabolic syndrome in pregnancy, with hyperinsulinemia and insulin resistance. Our clinical studies showed that mild gestational hyperglycemia or gestational diabetes are related to similar adverse maternal and perinatal outcomes. Hyperglycemia and other factors associated with diabetes generate reactive oxygen species that increase DNA damage levels. The aim of this study was to evaluate oxidative DNA damage in lymphocytes of pregnant women with diabetes or mild gestational hyperglycemia.

Objective: Experimental studies have shown that exposure to cigarette smoke has negative effects on lipid metabolism and oxidative stress status. Cigarette smoke exposure in nonpregnant and pregnant rats causes significant genotoxicity (DNA damage). However, no previous studies have directly evaluated the effects of obesity or the association between obesity and cigarette smoke exposure on genotoxicity. Therefore, the aim of the present investigation was to evaluate DNA damage levels, oxidative stress status and lipid profiles in obese Wistar rats exposed to cigarette smoke.Design and Methods: Female rats subcutaneously (sc) received a monosodium glutamate solution or vehicle (control) during the neonatal period to induce obesity. The rats were randomly distributed into three experimental groups: control, obese exposed to filtered air, and obese exposed to tobacco cigarette smoke. After a 2‐month exposure period, the rats were anesthetized and killed to obtain blood samples for genotoxicity, lipid profile, and oxidative stress status analyses.Results: The obese rats exposed to tobacco cigarette smoke presented higher DNA damage, triglycerides, total cholesterol, free fatty acids, VLDL‐c, HDL‐c, and LDL‐c levels compared to control and obese rats exposed to filtered air. Both obese groups showed reduced SOD activity. These results showed that cigarette smoke enhanced the effects of obesity.Conclusion: In conclusion, the association between obesity and cigarette smoke exposure exacerbated the genotoxicity, negatively impacted the biochemical profile and antioxidant defenses and caused early glucose intolerance. Thus, the changes caused by cigarette smoke exposure can trigger the earlier onset of metabolic disorders associated with obesity, such as diabetes and metabolic syndrome.

This study aimed to evaluate the genotoxicity (DNA damage levels) in lymphocyte samples from pregnant Wistar rats with severe or mild diabetes and in whole blood samples from their newborns. Wistar female rats (1 and 90 days of age) and male rats (approximately 90 days of age) were used. The experiment consisted of 2 experimental groups (n=8 animals/group): 1) rats with severe diabetes, 2) rats with mild diabetes. For mild diabetes induction, the rats received streptozotocin (STZ) subcutaneously (100 mg/kg body weight) at day of birth, and those showing glycemia from 120 to 300 mg/dL in their adult life were included. For induction of severe diabetes, adult rats received 40 mg/kg STZ (intravenous route), and those showing glycemia > 300 mg/dL were included. At day 21 of pregnancy, the rats were anesthetized and euthanized for removal of maternal and fetal blood samples for determination of the oxidative DNA damage by applying Endo III and Fpg using the comet assay. Thus, the rats with mild diabetes and their offspring showed higher Fpg-sensitive sites, reflecting the damage resulting from hyperglycemia. The rats with severe diabetes and their offspring showed higher oxidative DNA damage detected by Fpg and Endo III-sensitive sites, showing general repercussions related to diabetes. The enzymatic treatment for DNA damage evidenced that the maternal repercussions of diabetes are associated with oxidative DNA damage of their newborn, which was not reflected using only the analysis of DNA damage free of the enzymes.

The purpose of this study was to evaluate the effects of cigarette smoke exposure before pregnancy on diabetic rats and their offspring development.

Background: Maternal hyperglycemia during early pregnancy is associated with increased risk of abnormalities in the offspring. Malformation rates among the offspring of diabetic mothers are 2–5-fold higher than that of the normal population, and congenital malformations are the major cause of mortality and morbidity in the offspring of diabetic mothers. Metabolic changes, such as hyperglycemia and the metabolites obtained from cigarettes both increase the production of reactive oxygen species (ROS) in the embryo or fetus, causing DNA damage. Objective: To evaluate the maternal and fetal genotoxicity, and to assess the incidence of fetal anomaly in diabetic female rats exposed to cigarette smoke at different stages of pregnancy in rats. Material and Method: Diabetes was induced by streptozotocin administration and cigarette smoke exposure was produced by a mechanical smoking device that generated mainstream smoke that was delivered into a chamber. Female Wistar rats were randomly assigned to: non-diabetic (ND) and diabetic (D) groups exposed to filtered air; a diabetic group exposed to cigarette smoke prior to and during pregnancy (DS) and a diabetic group only exposed to cigarette smoke prior to pregnancy (DSPP). On pregnancy day 21, blood samples were obtained for DNA damage analysis and fetuses were collected for congenital anomaly assessment. Statistical significance was set at pResults and Conclusion: Exposure of diabetic rats to tobacco smoke prior to pregnancy increased fetal DNA damage, but failed to induce teratogenicity. Thus, these results reinforce the importance for women to avoid exposure to cigarette smoke long before they become pregnant.