Date of Completion

Spring 5-1-2016

Thesis Advisor(s)

Sarah A. Reed

Honors Major

Animal Science

Disciplines

Animals | Cardiology | Cardiovascular Diseases | Cardiovascular System | Cell Biology | Cellular and Molecular Physiology | Developmental Biology | Human and Clinical Nutrition | Molecular, Genetic, and Biochemical Nutrition | Other Nutrition | Pathological Conditions, Signs and Symptoms | Physiological Processes

Abstract

Maternal malnutrition can affect fetal organogenesis, metabolic processes, and factors involved in developmental regulation. Of the many physiological effects poor maternal nutrition can induce in offspring, one of the most important organs affected is the heart. Cardiovascular disease has been associated with poor maternal diet. It also been suggested that hypertension can originate during impaired intrauterine growth and development. Hypertension can trigger hypertensive heart disease and is associated with numerous heart complications. We hypothesized that poor maternal nutrition would alter critical growth factors associated with normal heart development, specifically, insulin-like growth factor (IGF)-1, IGF-2, transforming growth factor (TGF)β, and connective tissue growth factor (CTGF). Ewes (n = 82) were fed control (100% of NRC), over-fed (140% of NRC), or restricted-fed (60% of NRC) diets. The left ventricles of fetuses were collected at d 90 and 135 of gestation and gene expression was analyzed by real-time PCR. Data were analyzed using a MIXED model with treatment, gender, time point, and offspring as main effects and all interactions. Statistical significance was considered at P ≤ 0.05 and a tendency at P > 0.05 and ≤ 0.10. IGF-2 mRNA expression was increased in OVER singletons when compared with OVER triplets (P = 0.04), in CON twins when compared with CON triplets (P = 0.038), in RES triplets when compared with CON (P = 0.031) and OVER triplets (P = 0.014), and in RES triplets when compared with RES singletons (P = 0.048). TGFβ mRNA expression was increased in RES females when compared with OVER females (P = 0.029). CTGF mRNA expression was increased in OVER twins when compared with RES twins (P = 0.0079), in RES triplets when compared with CON triplets (P = 0.017), in RES triplets when compared with RES singletons (P = 0.0028) and twins (P = 0.0009), in RES males when compared with CON (P = 0.05) and OVER males (P = 0.018), and was decreased in RES males when compared with RES females (P = 0.034). There were no effects of offspring number by treatment (P = 0.5806), gender by time point (P = 0. 6349), treatment by gender (P = 0.6233), or offspring by time point (P = 0.6470) on IGF-1 mRNA expression. These results suggest that poor maternal nutrition affects expression of cardiac markers important for normal heart development in a manner specific to treatment, gender, and litter size.