Effect of lactational high fat diet and metformin on mid-lactation murine mammary gland gene expression
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ABSTRACT: Maternal health and diet can have important consequences for offspring nutrition and metabolic health. Signals are communicated from the mother to the infant during lactation through milk via macronutrients, hormones and bioactive molecules. In this study we designed experiments to probe the mother-milk-infant triad in the condition of normal maternal health and upon exposure to high fat diet (HFD) with or without concurrent metformin exposure. We examined maternal characteristics, milk composition and offspring metabolic parameters on postnatal day 16, prior to offspring beginning to wean. We found that lactational HFD increased maternal adipose tissue, mammary gland adipocytes, and altered milk lipid composition causing a higher amount of n-6 long chain fatty acids and lower n-3. Offspring of HFD dams were heavier with more body fat during suckling. Metformin exposure decreased maternal glucose and several amino acids. Offspring of met dams were smaller during suckling. Gene expression in the lactating mammary glands was impacted to a greater extent by metformin but both metformin and HFD altered genes related to muscle contraction, indicating that these genes may be more susceptible to lactational stressors. Our study demonstrates the impact of common maternal exposures during lactation on milk composition, mammary gland function and offspring growth with metformin having little capacity to recuse from the effects of a maternal HFD during lactation.
Project description:The goal was to study the long term metabolic programming effects of exposure of offspring to a dam eating 60% high fat diet during the lactation period only. We previously showed that offspring from dams given lactational high fat diet (HFD) are predisposed to obesity, glucose intolerance and inflammation. The purpose of these studies was to understand the programming implications of lactational HFD on offspring metabolic liver disease risk. Dams were fed a 60% lard-based HFD from the day of delivery through the 21 day lactation period. Starting at weaning offspring were fed normal fat diet until 3 months of age at which point a subset were challenged with an additional HFD stressor. Lactational HFD fed male offspring developed hepatic insulin resistance. Postweaning HFD challenge led male offspring progressing to NAFLD with more severe outcomes in the lactational HFD challenged offspring.
Project description:Early-life factors, including nutrition, shape long-term health outcomes. Despite the essential role of lactation in maternal nutritional support, the influence of epigenetic factors on lactation and postnatal growth remains poorly understood. Zinc-finger protein 57 (ZFP57), is an epigenetic regulator of genomic imprinting, a process that directs gene expression based on parental origin, playing a vital role in mammalian prenatal growth. Here, we identify a novel function of ZFP57 in the mammary glandI, where it serves as a key modulator of postnatal resource control, independently of imprinted genes. ZFP57 regulates multiple aspects of mammary gland functions, including ductal branching and cellular homeostasis. Its absence leads to significant differential gene expression, related to alveologenesis, lactogenesis and milk synthesis, associated with delayed lactation and altered milk composition. This results in life-long impacts on offspring including the development of metabolic syndrome. Cross-fostering reveals intricate dynamics between mother and offspring during lactation. Pups raised by a dam of a different genotype than their birth mother exhibit exacerbated metabolic features in adulthood, providing additional novel insight into the programming of offspring long-term health by maternal context. This study deepens our understanding of the interplay between epigenetic factors, lactation, and postnatal resource control.
Project description:Non-steroidal anti-inflammatory drug activated gene 1 (NAG-1) plays some role in reducing obesity in mice overexpressing human NAG-1, even on a high fat diet. Male and female hNAG-1 expressing mice have reduced body weight, increased longevity and metabolic activity. This study investigates the role of hNAG-1 in female reproduction and finds that the female mice have reduced fertility and pup survival after birth. Examination of the mammary glands in these mice suggests that hNAG-1 overexpressing mice have altered mammary epithelial development during pregnancy, including reduced occupancy of the fat pad and increased apoptosis via TUNEL positive cells at lactation day 2. Pups nursing from hNAG-1 overexpressing dams have reduced milk spots compared to pups nursing from WT dams. When CD-1 pups were cross-fostered with hNAG-1 or WT dams; reduced milk volume was observed in pups nursing from hNAG-1 dams compared to pups nursing from WT dams in a lactation challenge study. Milk was isolated from WT and hNAG-1 dams, and the milk was found to have secreted NAG-1 protein (approximately 25ng/mL) from hNAG-1 dams compared to WT dams, which had no detectable NAG-1 in the milk. A decrease in non-esterified free fatty acids in the milk of hNAG-1 dams was observed. Altered milk composition suggests that the pups were receiving inadequate nutrients during perinatal development; to examine this hypothesis serum was isolated from pups and clinical chemistry points were measured. Male and female pups nursing from hNAG-1 dams had reduced serum triglyceride concentrations. Cidea/CIDEA expression was reduced in hNAG-1 mammary glands, and microarray analysis suggests that genes involved in lipid metabolism are differentially expressed in hNAG-1 mammary glands. This study suggests that overexpression of hNAG-1 impairs lactational differentiation and pup survival due to altered milk quality and quantity 4 WT mammary glands on lactation day 2 and 5 hNAG-1 transgenic mice mammary glands on lactation day 2 were used.
Project description:Developmental programming is the concept that environmental factors, particularly during foetal life, can alter development, metabolism and physiology of an organism and this can have consequences later in life. There is growing interest in developmental programming in livestock species, particularly effects of maternal pregnancy nutrition, which is easy to manipulate. Recent research, using a sheep model, has shown that milk production in ewe offspring may be susceptible to maternal nutritional programming, such that over nutrition (ad libitum) of the pregnant dam, compared with maintenance nutrition, may impair their first lactation performance and result in the weaning of lighter lambs. RNA-seq was performed to identify gene expression differences as a result of maternal nutrition in ewe offspring during their first parity. Samples were collected in late pregnancy and during lactation, allowing us to examine gene expression changes during maturation of the ovine mammary gland. Three biological replicates were sequenced for each of the treatment conditions (maternal nutrition: sub-maintenance, maintenance, and ad libitum) and time points (late pregnancy and lactation). Each biological replicate consisted of RNA from multiple individuals (late pregnancy n=3, lactation n=2).
Project description:High throughput sequencing of miRNAs collected from tammar milk at different time points of lactation showed high levels of miRNA secreted in milk and allowed the identification of differentially expressed milk miRNAs during the lactation cycle as putative markers of mammary gland activity and functional candidate signals to assist growth and timed development of the young. Comparative analysis of miRNA distribution in milk and blood serum suggests that milk miRNAs are primarily expressed from mammary gland rather than transferred from maternal circulating blood, likely through a new putative exosomal secretory pathway.
Project description:High throughput sequencing of miRNAs collected from tammar milk at different time points of lactation showed high levels of miRNA secreted in milk and allowed the identification of differentially expressed milk miRNAs during the lactation cycle as putative markers of mammary gland activity and functional candidate signals to assist growth and timed development of the young. Comparative analysis of miRNA distribution in milk and blood serum suggests that milk miRNAs are primarily expressed from mammary gland rather than transferred from maternal circulating blood, likely through a new putative exosomal secretory pathway. 8 profiles were produced. Duplicates of day175
Project description:Maternal nutrition during embryonic development and lactation influences multiple aspects of offspring health. Using mice, this study investigates the effects of maternal caloric restriction (CR) during mid-gestation and lactation on offspring neonatal development and on adult metabolic function when challenged by a high fat diet (HFD). The CR maternal model produced male and female offspring that were significantly smaller, in terms of weight and length, and females had delayed puberty. Adult offspring born to CR dams had a sexually dimorphic response to the high fat diet. Compared to offspring of maternal control dams, adult female, but not male, CR offspring gained more weight in response to high fat diet at 10 weeks. In adipose tissue of male HFD offspring, maternal undernutrition resulted in blunted expression of genes associated with weight gain and increased expression of genes that protect against weight gain. Regardless of maternal nutrition status, HFD male offspring showed increased expression of genes associated with nonalcoholic liver disease (NAFLD). Furthermore, we observed significant, sexually dimorphic differences in serum TSH. These data reveal tissue- and sex-specific changes in gene and hormone regulation following mild maternal undernutrition, which may offer protection against diet induced weight gain in adult male offspring.
Project description:Different lactation stages have marked influence on milk yield, milk constituents and nourishment of the neonates. However, the differential gene expression during different lactation stages in Bosindicus has not been investigated so far. In this study, we carried out high-resolution mass spectrometry-based quantitative proteomics of bovine whey at early, mid and late lactation stages of MalnadGidda (Bosindicus) cows. Using TMT-based quantitative proteomics, we compared the bovine whey proteins on progressive lactation stages of Indian breed, MalnadGidda(Bosindicus). LC-MS/MS analysis of whey peptides from early, mid and late lactation stages resulted in the generation of 420,092 MS/MS spectra and 50,800 peptide spectrum matches, which led to the identification of 4,450 peptides corresponding to 725 proteins. Out of which, 440 proteins were differentially expressed (≥1.5-fold). Gene Ontology studies showed that proteins that regulatemilk composition and mammary growth associated proteins are abundantly expressed during peak lactation stages. Whereas, proteins related to pregnancy and mammary involution are expressed high in late and mid lactation stages indicating the physiological changes in the maternal system of bovine during drying period. Detection of progestagen associated endometrial protein; an immune protein seen in the fetomaternal interface and other pregnancy associated proteins at mid lactation suggest a candidate biomarker for the early pregnancy diagnosis. These results are overlapping with the previous findings addressed in milk from exotic breeds. We strongly believe that this preliminary investigation on differential proteome in milk whey over the course of lactation of indigenous cattle could answer many unsolved questions in lactation biology.
Project description:The aim of the present study was to correlate lipid metabolism genes in the mammary gland tissue affected by stage of lactation and nutrition to the resulting milk fatty acids composition in grazing dairy cows, and to classify milk fatty acid (FA) groups based on variations in lipid metabolism gene expression patterns. Identifying the relationship between lipid metabolism genes in the mammary gland tissue and the resulting milk fatty acid composition is expected to greatly contribute to our understanding of milk fatty acid metabolism and to enhance opportunities to improve milk fat composition through nutrition. In fact, SNCA, SCD5, and PNPLA2 lipid metabolism-related genes affected by unsaturated fatty acids supplementation, were found to strongly correlated to different milk FA groups, but also contributed most to the classification of these FA groups, suggesting a significant role in mediating the lipid metabolism in the mammary gland tissue and determining the milk fatty acids composition. A total of 28 Holstein-Friesian dairy cows in mid-lactation were blocked according to parity (2.4 ± 0.63 years), days in milk (DIM; 153 ± 32.8 days), milk yield (25.7 ± 3.08 kg/d) and fat content (4.3 ± 0.12%). Cows were then randomly assigned to four UFA-sources based on rapeseed, soybean, linseed or a mixture of the three oils for 23 days (Period I) after which, all 28 cows were switched to a control diet for an additional 28 days (Period II). On the last day of both periods, mammary gland biopsies were taken to study genome-wide differences in lipid metabolism gene expression.
Project description:Developmental programming is the concept that environmental factors, particularly during foetal life, can alter development, metabolism and physiology of an organism and this can have consequences later in life. There is growing interest in developmental programming in livestock species, particularly effects of maternal pregnancy nutrition, which is easy to manipulate. Recent research, using a sheep model, has shown that milk production in ewe offspring may be susceptible to maternal nutritional programming, such that over nutrition (ad libitum) of the pregnant dam, compared with maintenance nutrition, may impair their first lactation performance and result in the weaning of lighter lambs. RNA-seq was performed to identify gene expression differences as a result of maternal nutrition in ewe offspring during their first parity. Samples were collected in late pregnancy and during lactation, allowing us to examine gene expression changes during maturation of the ovine mammary gland.