Maternal pregnancy hypertension impairs nitric oxide formation and results in increased arterial blood pressure in first-generation offspring female rats.

OBJECTIVES: Maternal endothelial dysfunction in pregnancy hypertension is related to impairment of nitric oxide (NO) formation. However, NO levels and hemodynamic repercussions on the female offspring remain unclear. Therefore, this study hypothesized that maternal pregnancy hypertension reduces circulating NO metabolites and increases arterial blood pressure in first-generation offspring female rats. STUDY DESIGN: Descendant female rats were distributed in four groups as follows: virgin offspring of normotensive (VN) and hypertensive (VH) mothers and pregnant offspring of normotensive (PN) and hypertensive (PH) mothers. Hemodynamic and biochemical analyses were performed. MAIN OUTCOME MEASURES: The systolic (SBP) and diastolic (DBP) blood pressure, heart rate (HR), and body weight were measured. NO metabolites in plasma, NO formation in human umbilical vein endothelial cells (HUVECs) incubated with plasma, and endothelial NO synthase (eNOS) expression in aortas were determined. RESULTS: Increased SBP, DBP, and reduced HR were found on the 60 days of life in the VH group, whereas the PH group showed increased SBP and HR on pregnancy day 7. All groups showed no differences in body weight gain and eNOS expression. Plasma levels of NO metabolites were increased in the PN compared to the other groups. Increases in the NO formation were greater in HUVECs incubated with plasma from VN and PN groups compared to the VH and PH groups. CONCLUSIONS: Female virgin and pregnant first-generation offspring rats from hypertensive pregnant mothers may have negative cardiovascular repercussions featured by increases in SBP, and possibly impaired NO formation is involved.

Prenatal exposure to a mixture of different phthalates increases the risk of mammary carcinogenesis in F1 female offspring.

Phthalates metabolites have been detected in the urine of pregnant and breastfeeding women. Thus, this study evaluated the adverse effects of maternal exposure to a mixture of six phthalates (Pth mix) on the mammary gland development and carcinogenesis in F1 female offspring. Pregnant female Sprague-Dawley rats were exposed daily to vehicle or Pth mix (35.22% diethyl-phthalate, 21.03% di-(2-ethylhexyl)-phthalate, 14.91% dibutyl-phthalate, 15.10% diisononyl-phthalate, 8.61% diisobutyl-phthalate, and 5.13% benzylbutyl-phthalate) by gavage at 20 µg/kg, 200 µg/kg or 200 mg/kg during gestational day 10 (GD 10) to postnatal day 21 (PND 21). After weaning (PND 22), some female offspring were euthanized for mammary gland analyses while other females received a single dose of N-methyl-N-nitrosourea (MNU, 50 mg/kg) or vehicle and then tumor incidence and multiplicity were recorded until PND 180. Maternal Pth mix exposure increased the number of Ki-67 and progesterone receptor-positive epithelial cells in the mammary gland from Pth mix 200 at µg/kg and 200 mg/kg groups. In addition, tumor incidence and mean number were higher only in Pth mix at 200 mg/kg when compared to the vehicle-treated group, and percentage of tumor-free animals was lower in Pth mix at 200 µg/kg and 200 mg/kg groups. The findings indicate that perinatal Pth mixture exposure increased susceptibility to MNU-induced mammary carcinogenesis in adult F1 female offspring.

Reproductive outcomes in rat female offspring from male rats co-exposed to rosuvastatin and ascorbic acid during pre-puberty.

Dyslipidemias are occurring earlier in different countries due to the increase of obesity, bad eating habits, and sedentary lifestyle. Rosuvastatin reduces serum cholesterol; however, several studies associated statin exposure with male reproduction impairment. Ascorbic acid (AA) is an antioxidant substance that plays a protective role in the male reproductive system. Male rats were randomly divided into 6 experimental groups (n = 10), which received saline solution 0.9%, 3 or 10 mg/kg/day of rosuvastatin, 150 mg/day of AA or 3 or 10 mg/kg/day of rosuvastatin associated with 150 mg/day of AA from post-natal day (PND) 23 until PND 53. On PND 100, males were mated with non-treated female rats to obtain the female pups. The day of vaginal opening and the first estrus were assessed in the offspring. Two sets of females were euthanized on the first estrus after PND 42 and PND 75 to evaluate the histology of reproductive organs and hormone levels. A third set was used for sexual behavior and fertility test around PND 75. Female offspring from males exposed or co-exposed to the higher dose of statin exhibited a lower number of corpora lutea during puberty. On sexual maturity, the experimental group from males that were exposed to 3 mg displayed lower uterine luminal epithelium area. Paternal exposure to rosuvastatin at pre-puberty diminished uterine luminal epithelium in female offspring suggesting epigenetic changes were initiated by statin. Ascorbic acid co-administered to pre-pubertal males was able to ameliorate the reproductive damage in rat female offspring in adulthood.

Developmental Origins of Breast Cancer: A Paternal Perspective.

The developmental origins of breast cancer have been considered predominantly from a maternal perspective. Although accumulating evidence suggests a paternal programming effect on metabolic diseases, the potential impact of fathers' experiences on their daughters' breast cancer risk has received less attention. In this chapter, we focus on the developmental origins of breast cancer and examine the emerging evidence for a role of fathers' experiences.

Investigation of Paternal Programming of Breast Cancer Risk in Female Offspring in Rodent Models.

Emerging experimental evidence show that fathers' experiences during preconception can influence their daughters' risk of developing breast cancer. Here we describe detailed protocols for investigation in rats and mice of paternally mediated breast cancer risk programming effects.

Sleep restriction during pregnancy and its effects on blood pressure and renal function among female offspring.

The influence of sleep restriction (SR) during pregnancy on blood pressure and renal function among female adult offspring was investigated. Pregnant Wistar rats were distributed into control and SR groups. The SR was performed between the 14th and 20th days of pregnancy (multiple platforms method for 20 h/day). At 2 months of age, half of the offspring from both groups were subjected to an ovariectomy (ovx), and the other half underwent sham surgery. The groups were as follows: control sham (Csham), control ovx (Covx), SR sham (SRsham), and SR ovx (SRovx). Renal function markers and systolic blood pressure (BPi, indirect method) were evaluated at 4, 6, and 8 months. Subsequently, the rats were euthanized, kidneys were removed, and processed for morphological analyses of glomerular area (GA), number of glomeruli per mm3 (NG), and kidney mass (KM). Increased BPi was observed in the Covx, SRsham, and SRovx groups compared to Csham at all ages. Increased plasma creatinine concentration and decreased creatinine clearance were observed in the SRsham and SRovx groups compared to the Csham and Covx groups. The SRovx group showed higher BPi and reduced creatinine clearance compared to all other groups. The SRovx group showed reduced values of GA and KM, as well as increased NG, macrophage infiltration, collagen deposit, and ACE1 expression at the renal cortex. Therefore, SR during pregnancy might be an additional risk factor for developing renal dysfunction and increasing BP in female adult offspring. The absence of female hormones exacerbates the changes caused by SR.

Paternal programming of breast cancer risk in daughters in a rat model: opposing effects of animal- and plant-based high-fat diets.

BACKGROUND: Although males contribute half of the embryo's genome, only recently has interest begun to be directed toward the potential impact of paternal experiences on the health of offspring. While there is evidence that paternal malnutrition may increase offspring susceptibility to metabolic diseases, the influence of paternal factors on a daughter's breast cancer risk has been examined in few studies. METHODS: Male Sprague-Dawley rats were fed, before and during puberty, either a lard-based (high in saturated fats) or a corn oil-based (high in n-6 polyunsaturated fats) high-fat diet (60 % of fat-derived energy). Control animals were fed an AIN-93G control diet (16 % of fat-derived energy). Their 50-day-old female offspring fed only a commercial diet were subjected to the classical model of mammary carcinogenesis based on 7,12-dimethylbenz[a]anthracene initiation, and mammary tumor development was evaluated. Sperm cells and mammary gland tissue were subjected to cellular and molecular analysis. RESULTS: Compared with female offspring of control diet-fed male rats, offspring of lard-fed male rats did not differ in tumor latency, growth, or multiplicity. However, female offspring of lard-fed male rats had increased elongation of the mammary epithelial tree, number of terminal end buds, and tumor incidence compared with both female offspring of control diet-fed and corn oil-fed male rats. Compared with female offspring of control diet-fed male rats, female offspring of corn oil-fed male rats showed decreased tumor growth but no difference regarding tumor incidence, latency, or multiplicity. Additionally, female offspring of corn oil-fed male rats had longer tumor latency as well as decreased tumor growth and multiplicity compared with female offspring of lard-fed male rats. Paternal consumption of animal- or plant-based high-fat diets elicited opposing effects, with lard rich in saturated fatty acids increasing breast cancer risk in offspring and corn oil rich in n-6 polyunsaturated fatty acids decreasing it. These effects could be linked to alterations in microRNA expression in fathers' sperm and their daughters' mammary glands, and to modifications in breast cancer-related protein expression in this tissue. CONCLUSIONS: Our findings highlight the importance of paternal nutrition in affecting future generations' risk of developing breast cancer.

Paternal selenium deficiency but not supplementation during preconception alters mammary gland development and 7,12-dimethylbenz[a]anthracene-induced mammary carcinogenesis in female rat offspring.

Breast cancer is a global public health problem and accumulating evidence indicates early-life exposures as relevant factors in the disease risk determination. Recent studies have shown that paternal nutrition can influence offspring health including breast cancer risk. Selenium is a micronutrient with essential role in central aspects of embryogenesis, male fertility and cancer and that has been extensively studied as a chemopreventive agent in several breast cancer experimental models. Thus, we designed an animal study to evaluate whether paternal selenium deficiency or supplementation during preconception could affect the female offspring mammary gland development and breast cancer susceptibility. Male Sprague-Dawley rats were fed AIN93-G diet containing 0.15 ppm (control diet), 0.05 ppm (deficient diet) or 1 ppm (supplemented diet) of selenium for 9 weeks and mated with control female rats. Mammary carcinogenesis was induced with 7,12-dimethylbenz[a]anthracene (DMBA) in their female offspring. Paternal selenium deficiency increased the number of terminal end buds, epithelial elongation and cell proliferation in the mammary gland of the female rat offspring and these effects were associated with higher susceptibility to DMBA-induced mammary tumors (increased incidence and higher grade tumors). On the other hand, paternal selenium supplementation did not influence any of these parameters. These results highlight the importance of father's nutrition including selenium status as a relevant factor affecting daughter's breast cancer risk and paternal preconception as a potential developmental stage to start disease preventive strategies.

Paternal nutrition and cancer programming: the influence of selenium deficiency or supplementation on the susceptibility of female offspring to chemically-induced mammary carcinogenesis / Nutrição paterna e programação do câncer: influência da deficiência ou suplementação com selênio na susceptibilidade da prole feminina à carcinogênese mamária quimicamente induzida

Breast cancer is an important public health problem. As mammary gland development is a dynamic process that initiates in embryonic life, recent evidence show that in-utero life exposure to maternal nutritional factors can alter mammary gland development and program breast cancer risk in adult life. Even tough studies focus on maternal nutrition, recent evidence show that paternal nutritional factors in-utero and during preconception also affects their female offspring mammary gland development and breast cancer susceptibility in adult life. Studies highlight epigenetic modulation of gene expression in the mammary gland as possible breast cancer programming underlying mechanisms. Selenium is a micronutrient with essential role in central aspects of embryogenesis, male fertility and that has been extensively studied as a chemopreventive agent in several breast cancer models. Among selenium possible mechanisms of action, modulation of cell proliferation, apoptosis, DNA damage, gene expression and epigenetic marks are highlighted. Thus, a rat experiment was conducted to evaluate whether paternal selenium deficiency or supplementation during preconception could affect mammary gland development and breast cancer risk, as well as possible molecular mechanisms involved. Four-week old male Sprague-Dawley rats were exposed to experimental diets (AIN93G) containing 0.15 (control), 0.05 (deficient) and 1ppm (supplemented) of selenium as sodium selenate for 9 weeks and mated with control females. At 7-week old, mammary carcinogenesis was induced in their female offspring by oral administration of 7,12 dymethylbenz[a] anthracene and mammary neoplasia development was evaluated. Paternal selenium deficiency during preconception altered mammary gland development as increased terminal end buds (TEBs) number, epithelial elongation and cell proliferation and decreased apoptosis that were associated with increased breast cancer risk (higher incidence and grade tumors). In addition, paternal selenium deficiency during preconception induced molecular alterations in the mammary gland of the female offspring such as global DNA hypomethylation, increased global levels of H3K27me3 and altered expression of genes related to early life and mammary gland development, apoptosis, cell cycle control, and DNA damage repair. Paternal selenium supplementation during preconception on the other hand did not influence breast cancer programing. Our data show that breast cancer risk can be determined in early-life stages trough the male germline molecular modulation and preconception as an important window of opportunity to start breast cancer prevention strategies. Assuring and adequate selenium intake by men could be a possible starting point

O câncer de mama é um importante problema de saúde pública. O desenvolvimento da glândula mamária é um processo dinâmico que se inicia na vida intrauterina e evidências recentes mostram que a exposição do feto a fatores nutricionais maternos altera o desenvolvimento da glândula mamária e a susceptibilidade ao câncer de mama na vida adulta. Mesmo com um maior foco na nutrição materna, evidências recentes apontam que a nutrição paterna no período intrauterino e de preconcepção também afetam o desenvolvimento da glândula mamária e o risco de câncer de mama da sua prole feminina na vida adulta. Estudos apontam a modulação epigenética da expressão de genes na glândula mamária como possíveis mecanismos envolvidos na programação do câncer de mama. O selênio é um micronutriente com papel essencial em aspectos centrais da embriogênese, fertilidade masculina e que tem sido extensivamente estudado como um agente quimiopreventivo em diferentes modelos de câncer de mama. Dentre os possíveis mecanismos de ação do selênio, destacam-se a capacidade de modulação da proliferação celular, apoptose, danos do DNA e da expressão de genes e mecanismos epigenéticos. Dessa forma, foi conduzido um experimento em ratos para avaliar se a deficiência ou suplementação paterna com selênio durante o período de preconcepção poderia afetar na prole feminina o desenvolvimento da glândula mamária e o risco ao câncer de mama na vida adulta, assim como possíveis mecanismos moleculares envolvidos. Ratos machos da linhagem Sprague-Dawley com 4 semanas de vida foram submetidos à dieta experimental AIN93G contendo 0,15 (controle); 0,05 (deficiente) e 1ppm (suplementada) com selênio na forma de selenato de sódio por 9 semanas e acasalados com fêmeas controle. Com 7 semanas de vida, a carcinogênese mamária foi iniciada na prole feminina através da administração oral do carcinógeno químico 7,12 dimetilbenz[a] antraceno e o desenvolvimento das neoplasias mamárias foi avaliado. A deficiência paterna de selênio causou alterações no desenvolvimento da glândula mamária da prole feminina como aumento no número de terminal end buds (TEBs), aumento da elongação do epitélio mamário, aumento da proliferação celular e diminuição da apoptose que foram associados ao aumento do risco do câncer de mama (maior incidência e agressividade das lesões). Além disso, a deficiência paterna de selênio causou alterações de nível molecular na glândula mamária da prole feminina como hipometilação global, aumento dos níveis globais de H3K27me3 e alteração na expressão de genes relacionados ao desenvolvimento no início da vida e da glândula mamária, apoptose, controle de ciclo celular e reparo de danos no DNA. A suplementação paterna com selênio não foi influenciou o desenvolvimento da glândula mamária e o risco ao câncer de mama na vida adulta. Nossos resultados mostram que o risco do câncer de mama pode ser determinado no início da vida através de influências paternas por meio da modulação de mecanismos moleculares e que o período de preconcepção se caracteriza como uma importante janela de susceptibilidade para iniciar estratégias de diminuição do risco do câncer de mama. Assegurar uma ingestão adequada de selênio por homens pode ser um possível ponto de partida