This proposed study; Investigation of mechanisms for transmission of impaired glucose metabolism in infants exposed to diabetes in utero, will test the overarching hypothesis that impaired maternal substrate oxidation (metabolic inflexibility) and placental lipotoxicity are characteristics of diabetic pregnancies and in utero development within these conditions programs a metabolically inflexible phenotype in the offspring.
This translational research study will obtain paired measures of metabolic flexibility (postprandial RQ minus basal RQ) in response to a standardized meal by indirect calorimetry in mother:infant dyads of diabetic and non-diabetic pregnancies. The downstream effects of the intrauterine exposure to diabetes and gestational lipotoxicity will be tested in the infant: 1) at birth by studying adipogenic pathways and mitochondrial function in umbilical cord mesenchymal stem cells cultured in myogenic conditions\[13\], and 2) by studying metabolic flexibility in the infant in a whole body infant calorimeter in response to a standardized meal. Mothers will be enrolled between (33-35 weeks of gestation) and their infants will be enrolled between 10-30 days of life with the following aims. Aim 1. Characterize metabolic flexibility and lipotoxicity in diabetic and non-diabetic pregnancies. Hypothesis 1A: In response to a standardized meal in late pregnancy, diabetic pregnancies will be metabolically inflexible (blunted switch in RQ from the fasted state to the postprandial state) compared to non-diabetic pregnancies matched for maternal age and pregravid BMI. Hypothesis 1B: Placenta from diabetic pregnancies will have higher lipid content, reduced mitochondrial content and lower rates of mitochondrial oxygen consumption compared to placenta from non-diabetic pregnancies. Aim 2. Test whether intrauterine exposure to maternal diabetes infers disordered substrate oxidation in offspring at birth (in myocytes cultured from umbilical cord mesenchymal stem cells) and early in postnatal life (metabolic flexibility in response to a standardized meal). Hypothesis 2A: Umbilical cord mesenchymal stem cells cultured in myogenic conditions from diabetic pregnancies will have greater lipid content, reduced mitochondrial content, and lower rates of mitochondrial electron transport oxygen consumption and fatty acid oxidation. Hypothesis 2B: In response to a standardized meal, offspring of diabetic pregnancies will be metabolically inflexible (blunted switch in RQ from the pre- to postprandial state) compared to offspring of non-diabetic pregnancies.
Study Type
OBSERVATIONAL
Pennington Biomedical Research Center
Baton Rouge, Louisiana, United States
Metabolic flexibility - Mother
Assessed during a mixed-meal test as the difference in RQ between the postprandial period and the fasting period via indirect calorimetry.
Time frame: One day
Metabolic Flexibility - Infant
Assessed during a standard infant formula test as the difference in RQ between the postprandial and the fasting period via indirect calorimetry.
Time frame: One day
Lipid content in placenta samples
Lipid content will be measured in placenta samples via immunohistochemistry antibody staining for lipid droplet proteins and by Oil Red O staining.
Time frame: One day (delivery)
Mitochondrial oxygen consumption rates in placenta samples
Oxygen consumption rates of isolated mitochondria from placenta will be measured by the SeaHorse device.
Time frame: One day (delivery)
Fat content in umbilical cord mesenchymal stem cells
Mesenchymal stem cells will be differentiated to a myogenic state and assessed for lipid content via Oil Red O staining
Time frame: One day (delivery)
Oxygen consumption rates in umbilical cord mesenchymal stem cells
Mesenchymal stem cells will be differentiated to a myogenic state and assessed for oxygen consumption rates using the Oroboros device.
Time frame: One day (delivery)
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Enrollment
18