Maternal Western-style diet affects offspring islet composition and function in a non-human primate model of maternal over-nutrition

Joseph M. Elsakr, Jennifer C. Dunn, Katherine Tennant, Sifang Kathy Zhao, Karly Kroeten, Raymond C. Pasek, Diana L. Takahashi, Tyler A. Dean, Digna R. Velez Edwards, Carrie E. McCurdy, Kjersti M. Aagaard, Alvin C. Powers, Jacob E. Friedman, Paul Kievit, Maureen Gannon

The Developmental Origins of Health and Disease (DOHaD) hypothesis states that the gestational and immediate postnatal environments influence long-term offspring health and play a role in adult disease etiology. Elsakr and colleagues used a well-established, non-human primate (NHP) model, the Japanese Macaque, to determine the consequences of exposure to Western-Style Diet (WSD) in utero and during lactation on islet cell mass and function in the offspring. Islets from offspring whose mothers had received WSD secreted more insulin in response to a glucose challenge ex vivo. Reduction of α-cell mass as a result of maternal WSD persists to three years of age even when offspring are weaned onto control diet.

Objective: In humans, offspring of women who are overweight or obese are more likely to develop metabolic disease later in life. Studies in lower animal species reveal that a calorically-dense maternal diet is associated with alterations in islet cell mass and function. The long-term effects of maternal diet on the structure and function of offspring islets with characteristics similar to humans are unknown. We used a well-established non-human primate (NHP) model to determine the consequences of exposure to Western-Style Diet (WSD) in utero and during lactation on islet cell mass and function in the offspring.

Methods: Female Japanese Macaques (Macaca fuscata) were fed either control (CTR) or WSD before and throughout pregnancy and lactation. Offspring were weaned onto CTR or WSD to generate four different groups based on maternal/offspring diets: CTR/CTR, WSD/CTR, CTR/WSD, and WSD/WSD. Offspring were analyzed at three years of age. Pancreatic tissue sections were immunolabelled to measure α- and β-cell mass and proliferation as well as islet vascularization. Live islets were also isolated to test the effects of WSD-exposure on islet function ex vivo. Offspring glucose tolerance was correlated with various maternal characteristics.

Results: α-cell mass was reduced as a result of maternal WSD exposure. α-cell proliferation was reduced in response to offspring WSD. Islet vasculature did not differ among the diet groups. Islets from WSD/CTR offspring secreted a greater amount of insulin in response to glucose ex vivo. We also found that maternal glucose tolerance and parity correlated with offspring glucose tolerance.

Conclusions: Maternal WSD exposure results in persistently decreased α-cell mass in the three-year old offspring. WSD/CTR islets secreted greater amounts of insulin ex vivo, suggesting that these islets are primed to hyper-secrete insulin under certain metabolic stressors. Although WSD did not induce overt impaired glucose tolerance in dams or offspring, offspring born to mothers with higher glucose excursions during a glucose tolerance test were more likely to also show higher glucose excursions.