No description available.

It is well established that exposure to adverse environments in early life including both maternal under and over-nutrition predisposes individuals to similar adverse traditionally adult onset diseases such as the metabolic syndrome. Epidemiological observations and animal models have highlighted that early life exposure to maternal under-nutrition has a detrimental effect on offspring kidney health. The prevalence of chronic kidney disease has increased rapidly in recent years, concurrently with the growing obesity epidemic. Obesity is now prevalent in all age groups within the population including women of child-bearing age. Despite this, the effect of early life exposure to maternal obesity on long-term kidney health has not been investigated in humans. Studies in animals have demonstrated that exposure to early life under-nutrition programs the offspring kidney. Offspring exposed to maternal calorie restriction or a low protein diet typically display a reduced number of nephrons and increased glomerular areas. No studies to date have investigated the effect of maternal obesity on early life kidney and glomerular morphology. To address this, as part of this thesis, kidney morphology was assessed at weaning in male mice exposed to maternal diet-induced obesity throughout gestation and lactation. There was no effect of maternal diet on the number of nephrons counted within a distinct region in the offspring kidneys. However, glomerular density was decreased and glomerular area was increased in offspring exposed to maternal obesity. Alterations in renal morphology in early life have been linked to hypertension and renal disease in adulthood in both epidemiological and animal studies. Therefore, a second aim of this thesis was to assess blood pressure, renal function and markers of renal damage in offspring exposed to maternal obesity throughout the life-course. Post-pubescent male offspring (8 weeks of age) exposed to maternal obesity displayed increased blood pressure but no signs of renal dysfunction or damage. However, by six months of age offspring exposed to maternal obesity had increased glomerulosclerosis and tubulointerstitial fibrosis. The obesity epidemic is attributed to a shift in behaviours towards consumption of energy dense foods and inactivity. In addition, evidence from human and animal studies has highlighted that exposure to maternal obesity primes offspring to prefer sugary and fatty foods and to consume more calories. As such, offspring exposed to maternal obesity are likely to encounter an obesogenic environment in later life. A third aim of this thesis was therefore to determine the effect of maternal obesity in combination with a post-weaning obesogenic diet on offspring kidney health. To address this aim, offspring either exposed to an obesogenic diet or control diet throughout pregnancy and lactation were weaned onto either an obesogenic or control diet themselves. Six month old offspring exposed to a post-weaning obesity alone displayed indices of renal dysfunction and damage including glomerulosclerosis and tubulointerstitial fibrosis. Importantly, exposure to maternal obesity exacerbated the renal fibrosis in offspring exposed to a post-weaning obesogenic diet. With the growing prevalence of maternal obesity globally, there is great interest in determining an effective intervention to prevent adverse health outcomes in exposed individuals. The Ozanne laboratory has shown that maternal exercise in obese dams during pregnancy reduces maternal serum insulin and offspring insulin to control levels, highlighting that maternal exercise may be a promising intervention to limit adult-onset diseases in offspring exposed to early life obesity. The final aim of this thesis was to therefore assess the effect of exercise during an obese pregnancy on markers of offspring renal development during late gestation. Gene markers of ureteric bud branching, an important precursor of nephrogenesis, were increased in fetuses exposed to maternal obesity with exercise as opposed to obesity alone. Additionally one of these gene markers correlated negatively with maternal insulin levels. Protein markers indicative of an active ureteric bud branching pathway were also increased in offspring exposed to maternal obesity with exercise. In conclusion, studies conducted in this thesis demonstrate that offspring exposed to maternal obesity show alterations in renal morphology in early life and are predisposed for renal disease in later life, especially when they are challenged with a post-weaning obesogenic diet. Maternal exercise might be an effective intervention to rescue offspring renal morphology and later life health associated with maternal obesity, however this requires further investigation. These results have important implications for future generations within the setting of an ever increasing obesity epidemic and a growing prevalence of chronic kidney diseases.

No description available.

Early embryogenesis is highlighted by the emergence of several embryonic end extraembryonic lineages. One such lineage is the primitive endoderm, which will eventually give rise to the yolk sac. Once believed to be a vestigial structure, the yolk sac is now believed to play a more prominent role in embryogenesis as it provides nutrients to the preimplantation embryo. The endoderm may also interact with the trophectoderm lineage, as they develop in close contact within the embryo. The efficiency of developing primitive endoderm in vitro is considerably low, leading to a lapse in our understanding of its development and function in cattle and other ruminants. The goal of the first study was to establish a protocol for developing primitive endoderm cultures and characterizing these cells. Bovine embryos were produced in vitro, and primitive endoderm outgrowths were created with fibroblast growth factor 2 (FGF2) supplementation. These cells can be produced in culture with 80.3 5.6% efficiency. Furthermore, outgrowths can be maintained in culture for 6-8 weeks before reaching a quiescent state. A true bovine primitive endoderm cell line does not currently exist, however, these cells hold potential in improving the current understanding of early lineage specification in cattle. A second set of studies was performed to examine the effects of maternal obesity on the preimplantation conceptus and endometrium. Exposure to maternal obesity in utero affects offspring development at the postnatal, adolescent, and adult stages of development; however, its impacts on early embryogenesis are not well studied. This work utilized an obese ewe model. Once the obese phenotype was established, ewes were bred. Conceptus and endometrial tissue were collected at D 14 of pregnancy, and samples were processed for RNA-sequencing analysis. There were no differences in pregnancy rate, ovulation rate, or pregnancies/ovulation between obese and lean animals. At an RPKM threshold of 0.2, fold-change 2, and FDR 0.05, 669 and 21 differentially expressed genes (DEGs) were identified between obese- and lean-derived endometrial samples and conceptus samples, respectively. Likewise, 137 DEGs were identified between male and female conceptuses. The PANTHER GO-Slim Biological Process system identified several biological processes affected by obesity in both the endometrium and conceptus tissue. GO terms do not currently exist for "placenta" and "trophoblast", so a literature search was conducted to identify DEGs involved in implantation and placentation. This revealed 125 placentation DEGs in the endometrium, and 4 DEGs in conceptuses between obese and lean groups. A follow-up study was conducted to examine the abundance of transcripts with regulatory roles in embryogenesis. Conceptuses exhibited differential expression of DNA methyltransferase 1 (DNMT1) based on obesity exposure, fibroblast growth factor receptor 2 (FGFR2) in a sex*obesity interaction, and peroxisome proliferator-activated receptor gamma (PPARG) and prostaglandin-endoperoxide synthase 2 (PTGS2) in a sex-specific manner. Collectively these results identify the preimplantation period as a susceptible time to maternal obesity in both conceptus and endometrial tissue. Together, these studies aim to provide a better understanding of the events controlling early embryogenesis, and insight into the implication of insults during this time. These findings will prove to be beneficial in establishing the link between maternal health, endometrial function, and subsequent offspring outcomes, with the hope of promoting a more viable embryo and thus healthier offspring. / Ph. D.

This study determined the effects of gestational obesity on the long-term metabolic status of the mother and if obesity management during or after pregnancy could attenuate these effects. At 120 days prior to estrus, 8 ewes received 100 percent of NRC nutrient requirements (control group) and 24 ewes had free access to feed (obesity induction). Beginning on day 42 of gestation, 8 obese ewes were restricted to 65 percent of NRC nutrient requirements. Following parturition, controls and all but one group of obese ewes were fed 100 percent of NRC nutrient requirements. At postpartum days (PPD) 1 and 150, glucose tolerance tests were administered to ewes. At both PPD1 and PPD150, obesity resulted in insulin resistance, impairment of whole-body glucose utilization, increased levels of circulating leptin, and altered profiles of amino acids in plasma; however, these effects were diminished in ewes receiving obesity management during or after gestation. Additionally at PPD150, obesity increased the circulating levels of ammonia and urea in ewes, which was prevented by realimentation to 100 percent NRC requirements. These results indicate that weight reduction in obese dams during pregnancy or after parturition can beneficially ameliorate the adverse effects of gestational obesity on the mother.

The prevalence of overweight and obesity have risen to epidemic proportions. Overweight and obesity are prominent risk factors for the development of chronic disease including diabetes, cardiovascular disease and cancer. Especially pronounced in women of reproductive age and children, the obesity epidemic represents a major threat to global health. Maternal obesity is a key predictor of childhood obesity and diseases of metabolic origin in adulthood. Previous work has demonstrated that the exposure to early life adversity, in the context of maternal obesity, is associated with an increased risk of metabolic disease and obesity in the offspring later in life. Although the mechanisms outlining the relationship between maternal and offspring obesity remain unclear, the intestinal microbiota has come forth as a promising area of research. To understand the factors involved in the maternal intestinal microbial shifts with healthy pregnancy, the preliminary study focused on investigating whether female sex-steroid hormones mediate maternal intestinal microbial shifts in non-pregnant, regularly cycling female mice. We have identified that intestinal microbial shifts are not associated with sex-steroid hormone fluctuations. The second study examined whether maternal intestinal microbial shifts that occur during obese pregnancy were associated with altered inflammatory signaling and function of the maternal intestine and placenta at a critical period of development; embryonic (E) day 14.5. Females fed a high fat diet (HFD) were significantly heavier at mating and throughout gestation compared to CON. At E14.5, High fat (HF) dams displayed increased adiposity, hyperglycemia, hyperinsulinemia, hyperleptinemia and were insulin resistant. Pregnancy and maternal obesity resulted in shifts in the maternal intestinal microbiota, where the most significant increase in microbial relative abundance was exhibited by the mucin degrading genus, Akkermansia. At E14.5, maternal intestinal microbial shifts were associated with higher maternal intestinal NFκB activity in all sections of the maternal intestine, most notably in the maternal colon. Maternal obesity was associated with increased Muc5ac mRNA levels and a modest increase in CD3+ T cells in the maternal colon at E14.5. However, maternal intestinal permeability was unchanged between groups. In the placenta, mRNA levels of key signaling components in the pro-inflammatory toll-like receptor 4 (TLR4) pathway; TRAF6, NFκB and potent pro-inflammatory cytokine TNF-α were increased and in HF females. Maternal obesity was associated with an increase in CD3+ T cells in the junctional zone (JZ), but not in the labyrinth zone (LZ) of the placenta at E14.5. These findings were associated with increased mRNA levels of critical nutrient transporters; glucose transporter 1 (GLUT1) and sodium-coupled neutral amino acid transporter 2 (SNAT2) and a modest increase in glucose transporter 3 (GLUT3) in HF placentae compared to CON. These data identify the mechanistic signaling pathways and cell types involved in modulating the intrauterine environment, thus contributing to the current literature devoted to the investigation of the developmental origins of obesity. / Thesis / Master of Science (MSc)

No description available.

The epidemic of maternal obesity is increasing worldwide. Simple, effective and acceptable interventions are needed to combat obesity and improve pregnancy outcomes in women with metabolic risk factors such as dyslipidaemia and obesity. Dietary and lifestyle interventions reduce gestational weight gain, however, their effect on maternal and fetal outcomes is not clearly known. I conducted a large pragmatic randomised trial to evaluate the effectiveness of a Mediterranean-based dietary intervention to reduce the risk of adverse maternal and fetal outcomes in pregnant women with metabolic risk factors (The ESTEEM trial). The intervention significantly reduced gestational diabetes and gestational weight gain by an average of 1.2 Kg with some protective effect on fetal outcomes. I analysed the methodological challenges encountered in the trial and discussed applied solutions. I conducted a systematic review on the commonly used dietary assessment tools in trials involving pregnant women to assess their characteristics, validity, and applicability. Self-reporting dietary tools were the most commonly used to assess dietary intake in pregnancy such as food frequency questionnaires. Only 8% of studies validated the chosen tools and applied a defined adherence criterion. I applied the findings of this review to develop and validate a custom designed food frequency questionnaire, and a short 12 items questionnaire, to assess the participants' adherence in the ESTEEM study. I assessed the dietary intake in a randomised cohort from the ESTEEM study and compared the questionnaires' accuracy to 24 hour dietary recalls as the reference method. Both the FFQ and the short questionnaire performed well for assessing the adherence to and the intake of key foods in the Mediterranean diet. I systematically reviewed available online information sources on the risks and management of obesity in pregnancy in the English language. I assessed 53 websites for their information credibility, accuracy, readability, content and technological quality. Overall I found that non-governmental funded websites that are obesity-specific and targeting healthcare users presented better overall information quality.

The management of obesity before a woman conceives is one of the most effective efforts a woman can take in decreasing her risk of obesity-related complications during pregnancy. Evidence supports the idea that maternal obesity influences maternal and fetal outcomes, leading to maternal and fetal morbidities. Physicians acknowledge the importance of screening women for obesity, but many do not refer patients for weight-loss therapy. In this study, the health belief model was used to explore the associations between participants' obesity risk of complications during pregnancy, the number of weight-loss interventions they attempted to implement prior to pregnancy, and how they viewed the success of their interventions. Participants were a random sample of 95 obese pregnant women older than 19 years participating in the supplemental WIC program in an urban community in Newark, New Jersey. A quantitative nonexperimental correlational study using descriptive and inferential statistics was used to analyze the data. The results of this study indicated that obese pregnant women did not perceive the risks associated with obesity as a problem, nor was there an association among the types of weight-loss methods attempted, the overall success of their weight-loss interventions, and ethnicity. Women who tried exercise and dietary restrictions or exercise only were more likely to experience success than those who tried other methods or combinations of methods (p = 0.012). The data provided can lead to better informed strategies by health care professionals to develop standards in healthcare, particularly obstetrics and gynecology offices and clinics, to help obese women be more compliant with treatment recommendations for reducing the risks of obesity-related health problems.

Doctor of Philosophy / Human Nutrition / Richard R. Rosenkranz / Child stunting refers to a condition where the child is relatively shorter in height, in comparison to their age group. Child stunting is a public health nutrition problem that hinders the development of future generations, not only physiologically but also potentially deprives their cognitive function and productivity. The demographic transition, conjoined with the epidemiological and nutrition transitions, has resulted in the coexistence of an over- and under-nutrition problem known as double burden of malnutrition, and child stunting has been a persistent part of the problem. In 2014, the World Health Organization (WHO) reported that one-fourth of the children in the developing countries have been suffering from child stunting. The objective of this research was to apply the behavioral epidemiology approach to tackle child stunting in households with double burden of malnutrition. It was hypothesized that unlike any other households with problem of child stunting, households with double burden of malnutrition possess some degree of capacity that, with proper support and direction, might enable them to help themselves reduce or prevent this nutrition-related debacle. Results from a secondary data analysis revealed that child stunting was associated with lower dietary diversity as an indication of poor food choice in the household, related to children’s nutrient requirements. Another cross-sectional study in this dissertation was conducted in an urban setting in Indonesia, and found that households with child stunting alone was associated with extreme food insecurity, while households with double burden of malnutrition ─ in the form of stunted child and overweight/obese mother (SCOWT) ─ was associated with even a mild degree of food insecurity. These results support our hypothesis that households with double burden of malnutrition lack the capacity to direct their resources properly to prevent child stunting. Most notably, we expected that the role of the mothers to manage healthy food choices through indirect measure of dietary diversity, availability and distribution within the household was lacking. In order to equip mothers with necessary components to be able to overcome these problems, we conducted a behaviorally based intervention that targeted mothers in the households experiencing the problem of double burden of malnutrition. The intervention provided the potential to achieve participant self-administered goal setting to improve diet, as well as child feeding behavior, by means of improved self-efficacy, nutrition literacy and dietary diversity. Maternal self-efficacy may be potentially enhanced by vicarious experience and active mastery experience gained during 6 sessions of behavioral intervention and verbal motivation by community health workers during 6 additional home visits. These studies, collectively comprising the present dissertation, present a message for policy makers in developing countries: nutrition literacy and behaviors for choosing healthy foods are lacking in mothers that affect both maternal and child food intake, but efforts such as improving vicarious and mastery experience on child feeding practices and healthy food choices can boost mother’s self-efficacy to engage in appropriate behaviors and improve their child’s nutrition.