Insulin and branched-chain amino acid depletion during mouse preimplantation embryo culture programmes body weight gain and raised blood pressure during early postnatal life

Mouse maternal low protein diet exclusively during preimplantation development (Emb-LPD) is sufficient to programme altered growth and cardiovascular dysfunction in offspring. Here, we use an in vitro model comprising preimplantation culture in medium depleted in insulin and branched-chain amino acids (BCAA), two proposed embryo programming inductive factors from Emb-LPD studies, to examine the consequences for blastocyst organisation and, after embryo transfer (ET), postnatal disease origin. Two-cell embryos were cultured to blastocyst stage in defined KSOM medium supplemented with four combinations of insulin and BCAA concentrations. Control medium contained serum insulin and uterine luminal fluid amino acid concentrations (including BCAA) found in control mothers from the maternal diet model (N-insulin + N-bcaa). Experimental medium (three groups) contained 50% reduction in insulin and/or BCAA (L-insulin + N-bcaa, N-insulin + L-bcaa, and L-insulin + N-bcaa). Lineage-specific cell numbers of resultant blastocysts were not affected by treatment. Following ET, a combined depletion of insulin and BCAA during embryo culture induced a non sex-specific increase in birth weight and weight gain during early postnatal life. Furthermore, male offspring displayed relative hypertension and female offspring reduced heart/body weight, both characteristics of Emb-LPD offspring. Combined depletion of metabolites also resulted in a strong positive correlation between body weight and glucose metabolism that was absent in the control group. Our results support the notion that composition of preimplantation culture medium can programme development and associate with disease origin affecting postnatal growth and cardiovascular phenotypes and implicate two important nutritional mediators in the inductive mechanism. Our data also have implications for human assisted reproductive treatment (ART) practice.     

Maternal undernutrition during the preimplantation period of rat development causes blastocyst abnormalities and programming of postnatal hypertension

Epidemiological studies have indicated that susceptibility of human adults to hypertension and cardiovascular disease may result from intrauterine growth restriction and low birth weight induced by maternal undernutrition. Although the 'foetal origins of adult disease' hypothesis has significant relevance to preventative healthcare, the origin and biological mechanisms of foetal programming are largely unknown. Here, we investigate the origin, embryonic phenotype and potential maternal mechanisms of programming within an established rat model. Maternal low protein diet (LPD) fed during only the preimplantation period of development (0-4.25 days after mating), before return to control diet for the remainder of gestation, induced programming of altered birthweight, postnatal growth rate, hypertension and organ/body-weight ratios in either male or female offspring at up to 12 weeks of age. Preimplantation embryos collected from dams after 0-4.25 days of maternal LPD displayed significantly reduced cell numbers, first within the inner cell mass (ICM; early blastocyst), and later within both ICM and trophectoderm lineages (mid/late blastocyst), apparently induced by a slower rate of cellular proliferation rather than by increased apoptosis. The LPD regimen significantly reduced insulin and essential amino acid levels, and increased glucose levels within maternal serum by day 4 of development. Our data indicate that long-term programming of postnatal growth and physiology can be induced irreversibly during the preimplantation period of development by maternal protein undernutrition. Further, we propose that the mildly hyperglycaemic and amino acid-depleted maternal environment generated by undernutrition may act as an early mechanism of programming and initiate conditions of 'metabolic stress', restricting early embryonic proliferation and the generation of appropriately sized stem-cell lineages.     

Metabolic Induction and Early Responses of Mouse Blastocyst Developmental Programming following Maternal Low Protein Diet Affecting Life-Long Health

Previously, we have shown that a maternal low protein diet, fed exclusively during the preimplantation period of mouse development (Emb-LPD), is sufficient to induce by the blastocyst stage a compensatory growth phenotype in late gestation and postnatally, correlating with increased risk of adult onset cardiovascular disease and behavioural dysfunction. Here, we examine mechanisms of induction of maternal Emb-LPD programming and early compensatory responses by the embryo. Emb-LPD induced changes in maternal serum metabolites at the time of blastocyst formation (E3.5), notably reduced insulin and increased glucose, together with reduced levels of free amino acids (AAs) including branched chain AAs leucine, isoleucine and valine. Emb-LPD also caused reduction in the branched chain AAs within uterine fluid at the blastocyst stage. These maternal changes coincided with an altered content of blastocyst AAs and reduced mTORC1 signalling within blastocysts evident in reduced phosphorylation of effector S6 ribosomal protein and its ratio to total S6 protein but no change in effector 4E-BP1 phosphorylated and total pools. These changes were accompanied by increased proliferation of blastocyst trophectoderm and total cells and subsequent increased spreading of trophoblast cells in blastocyst outgrowths. We propose that induction of metabolic programming following Emb-LPD is achieved through mTORC1signalling which acts as a sensor for preimplantation embryos to detect maternal nutrient levels via branched chain AAs and/or insulin availability. Moreover, this induction step associates with changes in extra-embryonic trophectoderm behaviour occurring as early compensatory responses leading to later nutrient recovery.     

Adaptive responses by mouse early embryos to maternal diet protect fetal growth but predispose to adult onset disease

Poor maternal nutrition during pregnancy can alter postnatal phenotype and increase susceptibility to adult cardiovascular and metabolic diseases. However, underlying mechanisms are largely unknown. Here, we show that maternal low protein diet (LPD), fed exclusively during mouse preimplantation development, leads to offspring with increased weight from birth, sustained hypertension, and abnormal anxiety-related behavior, especially in females. These adverse outcomes were interrelated with increased perinatal weight being predictive of later adult overweight and hypertension. Embryo transfer experiments revealed that the increase in perinatal weight was induced within blastocysts responding to preimplantation LPD, independent of subsequent maternal environment during later pregnancy. We further identified the embryo-derived visceral yolk sac endoderm (VYSE) as one mediator of this response. VYSE contributes to fetal growth through endocytosis of maternal proteins, mainly via the multiligand megalin (LRP2) receptor and supply of liberated amino acids. Thus, LPD maintained throughout gestation stimulated VYSE nutrient transport capacity and megalin expression in late pregnancy, with enhanced megalin expression evident even when LPD was limited to the preimplantation period. Our results demonstrate that in a nutrient-restricted environment, the preimplantation embryo activates physiological mechanisms of developmental plasticity to stablize conceptus growth and enhance postnatal fitness. However, activation of such responses may also lead to adult excess growth and cardiovascular and behavioral diseases.     

Induction of a phosphate appetite in adult male and female rats

We have reported that dietary inorganic phosphate (Pi) deprivation induces a Pi-seeking behavior in juvenile male rats. The purpose of the present study was to determine whether the Pi appetite is present in adult animals, and if so, whether it is altered during times of increased demand for Pi, such as pregnancy and lactation. Both male and female animals fed a low-phosphate diet (LPD) ingested significantly greater amounts of PiH(2)O daily than their normal phosphate diet (NPD) controls, and per 100 g of body weight (BW), the female animals fed LPD tended to ingest greater amounts of PiH(2)O than male rats fed LPD. Pregnant and lactating rats fed LPD ingested significantly more PiH(2)O than those fed NPD, however, neither group displayed a Pi appetite different than virgin females. However, lactation further reduced Pi levels in plasma and cerebral spinal fluid compared with control values. Despite the additional Pi from the PiH(2)O in the mothers fed LPD, pup birth weight was significantly lower than in NPD litters, and this was exacerbated 9 days after birth. This attenuated BW gain was associated with lower plasma Pi levels in the pups. In conclusion, a mild but consistent Pi-seeking behavior is induced in adult male and female rats after only 2 days of dietary Pi restriction. On a relative basis, the amount of PiH(2)O ingested is greater in female than in male animals, but does not increase further during pregnancy and lactation.     

Maternal consumption of low-isoflavone soy protein isolate alters hepatic gene expression and liver development in rat offspring

In utero environment is known to affect fetal development. Especially, the distinct fetal programming of carcinogenesis was reported in offspring exposed to maternal diets containing soy protein isolate (SPI) or genistein. Therefore, we investigated whether maternal consumption of low-isoflavone SPI or genistein alters hepatic gene expression and liver development in rat offspring. Female Sprague–Dawley rats were fed a casein diet, a low-isoflavone SPI diet or a casein diet supplemented with genistein (250 mg/kg diet) for 2 weeks before mating and throughout pregnancy and lactation. Male offspring were studied on postnatal day 21 (CAS, SPI and GEN groups). Among 965 differentially expressed hepatic genes related to maternal diet (P<.05), the expression of 590 was significantly different between CAS and SPI groups. Conversely, the expression of 88 genes was significantly different between CAS and GEN groups. Especially, genes involved in drug metabolism were significantly affected by the maternal diet. SPI group showed increased cell proliferation, reduced apoptosis and activation of the mTOR pathway, which may contribute to a higher relative liver weight compared to other groups. We observed higher serum homocysteine levels and lower global and CpG site-specific DNA methylation of Gadd45b, a gene involved in cell proliferation and apoptosis, in SPI group compared to CAS group. Maternal SPI diet also reduced histone H3-Lysine 9 (H3K9) trimethylation and increased H3K9 acetylation in offspring. These results demonstrate that maternal consumption of a low-isoflavone SPI diet alters the hepatic gene expression profile and liver development in offspring possibly by epigenetic processes.     

Maternal high-fat diet induces sex-specific endocannabinoid system changes in newborn rats and programs adiposity,energy expenditure and food preference in adulthood

Early life inadequate nutrition triggers developmental adaptations and adult chronic disease. Maternal high-fat (HF) diet promotes visceral obesity and hypothalamic leptin resistance in male rat offspring at weaning and adulthood. Obesity is related to over active endocannabinoid system (ECS). The ECS consists mainly of endogenous ligands, cannabinoid receptors (CB1 and CB2), and the enzymes fatty acid anandamide hydrolase (FAAH) and monoacylglycerol lipase (MAGL). We hypothesized that perinatal maternal HF diet would regulate offspring ECS in hypothalamus and brown adipose tissue (BAT) at birth, prior to visceral obesity development, and program food preference and energy expenditure of adult offspring. Female rats received control diet (C, 9% fat) or isocaloric high-fat diet (HF, 28% fat) for 8 weeks before mating, and throughout gestation and lactation. We evaluated C and HF offspring at birth and adulthood. At birth, maternal HF diet decreased leptinemia and increased hypothalamic CB1, orexin-A, and proopiomelanocortin while it decreased thyrotropin-releasing hormone (Trh) in male pups. Differentially, maternal HF diet increased hypothalamic CB2 in female pups. In BAT, maternal HF diet decreased CB1 and increased CB2 in male and female pups, respectively. Besides presenting different molecular ECS profile at birth, HF adult offspring developed overweight, higher adiposity and high-fat diet preference, independently of the sex, but only males presented hyperleptinemia and higher energy expenditure. In conclusion, maternal HF diet alters ECS components and energy metabolism targets in hypothalamus and BAT of offspring at birth, in a sex-specific manner, which may contribute for hyperphagia, food preference and higher adiposity later in life.     

Impact of maternal undernutrition during the periconceptional period, fetal number, and fetal sex on the development of the hypothalamo-pituitary adrenal axis in sheep during late gestation

Evidence from epidemiologic, clinical, and experimental studies has shown that a suboptimal intrauterine environment during early pregnancy can alter fetal growth and gestation length and is associated with an increased prevalence of adult hypertension and cardiovascular disease. It has been postulated that maternal nutrient restriction may act to reprogram the development of the pituitary-adrenal axis, resulting in excess glucocorticoid exposure and adverse health outcomes in later life. It is unknown, however, whether maternal nutrient restriction during the periconceptional period alters the development of the fetal pituitary-adrenal axis or whether the effects of periconceptional undernutrition can be reversed by the provision of an adequate level of maternal nutrition throughout the remainder of pregnancy. We have investigated the effect of restricted periconceptional nutrition (70% of control feed allowance) from 60 days before until 7 days after mating and the effect of restricted gestational nutrition from Day 8 to 147 of gestation on the development of the fetal hypothalamo-pituitary adrenal (HPA) axis in the sheep. In these studies, we have also investigated the effects of fetal number and sex on the pituitary-adrenal responses to periconceptional and gestational undernutrition. In ewes maintained on a control diet throughout the periconceptional and gestational periods, fetal plasma ACTH concentrations were higher and the prepartum surge in cortisol occurred earlier in singletons compared with twins. Plasma ACTH concentrations were also significantly higher in male compared with female singletons, and in twin fetuses, the prepartum surge in cortisol concentrations occurred earlier in males than in females. Periconceptional undernutrition resulted in higher fetal plasma concentrations of ACTH between 110 and 145 days of gestation and a significantly greater cortisol response to a bolus dose of corticotropin-releasing hormone in twin, but not singleton, fetuses in late gestation. We have therefore demonstrated that fetal number and sex each has an impact on the timing of the prepartum activation of the HPA axis in the sheep. Restriction of the level of maternal nutrition before and in the first week of a twin pregnancy results in stimulation of the fetal pituitary-adrenal axis in late gestation, and this effect is not reversed by the provision of a maintenance control diet from the second week of pregnancy.     

Brain TRH and Cyclo (His-Pro) and brain protein in the newborn rat are altered by maternal liquid protein feeding

Liquid protein diet (LPD) has been shown previously to produce maternal and fetal weight loss and fetal congenital anomalies, including cataracts and craniofacial malformations. Therefore, to examine the effects of LPD in pregnancy upon the central nervous system of pups, pregnant dams were fed either a 20% casein diet ad libitum, a 20% LPD, or pair-fed with a 20% casein diet. LPD was associated with significant maternal weight loss, and pups had significantly lower birth weights (5.14 +/- 0.64) than pups from the pair-fed controls (5.70 +/- 0.46, p less than 0.05). Total brain protein content was reduced significantly in pups of both sexes from pregnant fed LPD. Moreover, the concentrations of two brain peptides neurotransmitters, thyrotropin-releasing hormone (TRH), and its biologically active metabolite, histidyl-proline diketopiperazine Cyclo (His-Pro), were elevated in the pups from LPD-fed mothers. In contrast, there was no significant difference in brain protein or brain peptides in pups from pair-fed mothers vs. pups from mothers fed ad libitum. These data suggest that qualitative alterations of the protein component in maternal dietary composition have deleterious effects upon the ontogeny of the rat fetal CNS, as reflected by reduced total protein and elevated concentrations of TRH and Cyclo (His-Pro).     

Impact of periconceptional nutrition on maternal and fetal leptin and fetal adiposity in singleton and twin pregnancies

It has been proposed that maternal nutrient restriction may alter the functional development of the adipocyte and the synthesis and secretion of the adipocyte-derived hormone, leptin, before birth. We have investigated the effects of restricted periconceptional undernutrition and/or restricted gestational nutrition on fetal plasma leptin concentrations and fetal adiposity in late gestation. There was no effect of either restricted periconceptional or gestational nutrition on maternal or fetal plasma leptin concentrations in singleton or twin pregnancies during late gestation. In ewes carrying twins, but not singletons, maternal plasma leptin concentrations in late gestation were directly related to the change in ewe weight that occurred during the 60 days before mating [maternal leptin = 0.9 (change in ewe weight) + 7.8; r = 0.6, P < 0.05]. In twin, but not singleton, pregnancies, there was also a significant relationship between maternal and fetal leptin concentrations (maternal leptin = 0.5 fetal leptin + 4.2, r = 0.63, P < 0.005). The relative mass of perirenal fat was also significantly increased in twin fetal sheep in the control-restricted group (6.0 +/- 0.5) compared with the other nutritional groups (control-control: 4.1 +/- 0.4; restricted-restricted: 4.4 +/- 0.4; restricted-control: 4.3 +/- 0.3). In conclusion, the impact of maternal undernutrition on maternal plasma leptin concentrations during late gestation is dependent on fetal number. Furthermore, we have found that there is an increased fetal adiposity in the twins of ewes that experienced restricted nutrition throughout gestation, and this may be important in the programming of postnatal adiposity.     

Effect of a Low-Protein Diet Supplemented with Ketoacids on Skeletal Muscle Atrophy and Autophagy in Rats with Type 2 Diabetic Nephropathy

A low-protein diet supplemented with ketoacids maintains nutritional status in patients with diabetic nephropathy. The activation of autophagy has been shown in the skeletal muscle of diabetic and uremic rats. This study aimed to determine whether a low-protein diet supplemented with ketoacids improves muscle atrophy and decreases the increased autophagy observed in rats with type 2 diabetic nephropathy. In this study, 24-week-old Goto-Kakizaki male rats were randomly divided into groups that received either a normal protein diet (NPD group), a low-protein diet (LPD group) or a low-protein diet supplemented with ketoacids (LPD+KA group) for 24 weeks. Age- and weight-matched Wistar rats served as control animals and received a normal protein diet (control group). We found that protein restriction attenuated proteinuria and decreased blood urea nitrogen and serum creatinine levels. Compared with the NPD and LPD groups, the LPD+KA group showed a delay in body weight loss, an attenuation in soleus muscle mass loss and a decrease of the mean cross-sectional area of soleus muscle fibers. The mRNA and protein expression of autophagy-related genes, such as Beclin-1, LC3B, Bnip3, p62 and Cathepsin L, were increased in the soleus muscle of GK rats fed with NPD compared to Wistar rats. Importantly, LPD resulted in a slight reduction in the expression of autophagy-related genes; however, these differences were not statistically significant. In addition, LPD+KA abolished the upregulation of autophagy-related gene expression. Furthermore, the activation of autophagy in the NPD and LPD groups was confirmed by the appearance of autophagosomes or autolysosomes using electron microscopy, when compared with the Control and LPD+KA groups. Our results showed that LPD+KA abolished the activation of autophagy in skeletal muscle and decreased muscle loss in rats with type 2 diabetic nephropathy.     

Adaptive responses of 25-hydroxyvitamin D3 1-alpha hydroxylase expression to dietary phosphate restriction in young and adult rats

Regulation of vitamin D metabolism alters with age. The present study is undertaken to investigate if the loss of renal 1,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3)) production in response to dietary phosphate (P) restriction in adult rats is due to an alteration in the renal expression of 25-hydroxyvitamin D(3) 1-alpha hydroxylase (1-OHase). Young (4-6 weeks old) and adult (12-14 weeks old) male Sprague Dawley rats were fed either normal P (NPD) or low P diet (LPD) for 0-5 days. Basal expression of 1-OHase protein was higher in adult rats. Young rats, but not adult rats, significantly increased 1-OHase protein and mRNA expressions in response to LPD in a time-dependent manner. To determine if the stability of renal 1-OHase protein changes with LPD feeding, young and adult rats fed either NPD or LPD for 5 days were injected intravenously with cycloheximide (CHX), a protein synthesis inhibitor. CHX decreased 1-OHase protein expression in young rats fed NPD. However, CHX did not alter 1-OHase protein expression in young rats fed LPD nor in adult rats fed either diet. The results indicate that the stability of renal 1-OHase protein increased with age and that LPD increased its stability only in young rats.     

Effect of a low-protein diet supplemented with keto-acids on autophagy and inflammation in 5/6 nephrectomized rats

Ketoacids (KA) are known to preserve muscle mass among patients with chronic kidney disease (CKD) on a low-protein diet (LPD). The present study was to compare the effects of KA supplemented diet therapy in autophagy and inflammation in CKD rats'' skeletal muscle. Rats with 5/6 nephrectomy were randomly divided into three groups and fed with either 11 g/kg/day protein [normal-protein diet (NPD)], 3 g/kg/day protein (LPD) or 3 g/kg/day protein which including 5% protein plus 1% KA (LPD + KA) for 24 weeks. Sham-operated rats with NPD intake were used as control. LPD could improve body weight, gastrocnemius muscle mass, as well as gastrocnemius muscle cross-sectional area, with the effect being more obvious in the LPD + KA group. The autophagy marker LC3 (microtubule-associated protein 1 light chain 3), p62, Parkin and PTEN induced putative kinase 1 (PINK1) were significantly attenuate in LPD + KA group than LPD group. LPD + KA group had the lower total mtDNA (mitochondiral DNA) and cytosol mtDNA, NACHT-PYD-containing protein 3 (NALP3) inflammasome than LPD group, but its reactive oxygen species (ROS), caspase-1 and apoptosis-associated speck-like protein containing a CARD (ASC) level was higher. Immunoblotting showed IL-1β (interleukin-1-beta) was lower in LPD and LPD + KA group than the NPD group, but IL-18 showed no significant difference among control and CKD group; toll-like receptor signalling-dependent IL-6 was higher in LPD + KA group than LPD group, but tumor necrosis factor-α (TNF-α) was not significantly changed between LPD + KA and LPD group. Systematic changes of the four cytokines were different from that of the tissue. Although LPD + KA could further ameliorate-activated autophagy than LPD, its effect on the activated inflammation state in CKD was not distinctly. Further study is still required to explore the method of ameliorating inflammation to provide new therapeutic approaches for CKD protein energy wasting (PEW).     

Effects of Maternal Diet and Exercise during Pregnancy on Glucose Metabolism in Skeletal Muscle and Fat of Weanling Rats

Obesity during pregnancy contributes to the development of metabolic disorders in offspring. Maternal exercise may limit gestational weight gain and ameliorate these programming effects. We previously showed benefits of post-weaning voluntary exercise in offspring from obese dams. Here we examined whether voluntary exercise during pregnancy influences lipid and glucose homeostasis in muscle and fat in offspring of both lean and obese dams. Female Sprague-Dawley rats were fed chow (C) or high fat (F) diet for 6 weeks before mating. Half underwent voluntary exercise (CE/FE) with a running wheel introduced 10 days prior to mating and available until the dams delivered; others remained sedentary (CS/FS). Male and female pups were killed at postnatal day (PND)19 and retroperitoneal fat and gastrocnemius muscle were collected for gene expression. Lean and obese dams achieved similar modest levels of exercise. At PND1, both male and female pups from exercised lean dams were significantly lighter (CE versus CS), with no effect in those from obese dams. At PND19, maternal obesity significantly increased offspring body weight and adiposity, with no effect of maternal exercise. Exercise significantly reduced insulin concentrations in males (CE/FE versus CS/FS), with reduced glucose in male FE pups. In males, maternal obesity significantly decreased muscle myogenic differentiation 1 (MYOD1) and glucose transporter type 4 (GLUT4) mRNA expressions (FS vs CS); these were normalized by exercise. Maternal exercise upregulated adipose GLUT4, interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and peroxisome proliferator activated receptor gamma coactivator 1 alpha (PGC1α) mRNA expression in offspring of dams consuming chow. Modest voluntary exercise during pregnancy was associated with lower birth weight in pups from lean dams. Maternal exercise appeared to decrease the metabolic risk induced by maternal obesity, improving insulin/glucose metabolism, with greater effects in male than female offspring.     

Maternal Malnutrition and Offspring Sex Determine Juvenile Obesity and Metabolic Disorders in a Swine Model of Leptin Resistance

The present study aimed to determine, in a swine model of leptin resistance, the effects of type and timing of maternal malnutrition on growth patterns, adiposity and metabolic features of the progeny when exposed to an obesogenic diet during their juvenile development and possible concomitant effects of the offspring sex. Thus, four groups were considered. A CONTROL group involved pigs born from sows fed with a diet fulfilling their daily maintenance requirements for pregnancy. The treated groups involved the progeny of females fed with the same diet but fulfilling either 160% or 50% of pregnancy requirements during the entire gestation (OVERFED and UNDERFED, respectively) or 100% of requirements until Day 35 of pregnancy and 50% of such amount from Day 36 onwards (LATE-UNDERFED). OVERFED and UNDERFED offspring were more prone to higher corpulence and fat deposition from early postnatal stages, during breast-feeding; adiposity increased significantly when exposed to obesogenic diets, especially in females. The effects of sex were even more remarkable in LATE-UNDERFED offspring, which had similar corpulence to CONTROL piglets; however, females showed a clear predisposition to obesity. Furthermore, the three groups of pigs with maternal malnutrition showed evidences of metabolic syndrome and, in the case of individuals born from OVERFED sows, even of insulin resistance and the prodrome of type-2 diabetes. These findings support the main role of early nutritional programming in the current rise of obesity and associated diseases in ethnics with leptin resistance.     

Maternal cigarette smoke exposure contributes to glucose intolerance and decreased brain insulin action in mice offspring independent of maternal diet

Background

Maternal smoking leads to intrauterine undernutrition and is associated with low birthweight and higher risk of offspring obesity. Intrauterine smoke exposure (SE) may alter neuroendocrine mediators regulating energy homeostasis as chemicals in cigarette smoke can reach the fetus. Maternal high-fat diet (HFD) consumption causes fetal overnutrition; however, combined effects of HFD and SE are unknown. Thus we investigated the impact of combined maternal HFD and SE on adiposity and energy metabolism in offspring.

Method

Female Balb/c mice had SE (2 cigarettes/day, 5 days/week) or were sham exposed for 5 weeks before mating. Half of each group was fed HFD (33% fat) versus chow as control. The same treatment continued throughout gestation and lactation. Female offspring were fed chow after weaning and sacrificed at 12 weeks.

Results

Birthweights were similar across maternal groups. Faster growth was evident in pups from SE and/or HFD dams before weaning. At 12 weeks, offspring from HFD-fed dams were significantly heavier than those from chow-fed dams (chow-sham 17.6±0.3 g; chow-SE 17.8±0.2 g; HFD-sham 18.7±0.3 g; HFD-SE 18.8±0.4 g, P<0.05 maternal diet effect); fat mass was significantly greater in offspring from chow+SE, HFD+SE and HFD+sham dams. Both maternal HFD and SE affected brain lactate transport. Glucose intolerance and impaired brain response to insulin were observed in SE offspring, and this was aggravated by maternal HFD consumption.

Conclusion

While maternal HFD led to increased body weight in offspring, maternal SE independently programmed adverse health outcomes in offspring. A smoke free environment and healthy diet during pregnancy is desirable to optimize offspring health.     

Fetal and neonatal exposure to AZT and low-protein diet affects glucose homeostasis: a model with implications for AIDS prevention

Zidovudine (AZT) lowers the perinatal transmission of HIV but can impair mitochondrial function by depleting mitochondrial DNA (mtDNA). AZT therapy and perinatal nutritional deprivation affect the body fat distribution, which influences glucose tolerance. We sought to model intrauterine exposure to AZT in humans to determine whether it interacts with low-protein diet (LPD) to impact on birth weight and glucose homeostasis in the offspring. Pregnant dams and their offspring were given AZT, an LPD, or AZT and an LPD (LPD + AZT). AZT reduced mtDNA copy number in liver and birth weight in the offspring and increased their fasting glucose and insulin (P = 0.021, 0.03, 0.001, and 0.011 respectively) at 6-8 wk of age. LPD decreased litter size and birth weight (P = 0.01 and 0.012). In the LPD + AZT group, birth weight and litter size were reduced compared with untreated controls, and fasting blood glucose and insulin were raised. There was a significant interaction between LPD and AZT on fasting insulin levels (P = 0.025). Islet size was not significantly affected, but the mean beta-cell area/islet was reduced in the LPD + AZT group compared with controls (P < 0.05). Early exposure to AZT interacts with LPD to impair fetal development in this model. This combination appeared to impair the supply of insulin and, hence, glucose homeostasis, perhaps as a result of impaired mitochondrial function. Although it is not certain that this can be extrapolated to humans, maternal nutritional deprivation combined with AIDS therapy could influence both birth weight and onset of diabetes.     

Increased maternal fat consumption during pregnancy alters body composition in neonatal mice

Maternal overnutrition prior to and during gestation causes pronounced metabolic dysfunction in the adult offspring. However, less is known about metabolic adaptations in the offspring that occur independently of postnatal growth and nutrition. Therefore, we evaluated the impact of excess maternal dietary lipid intake on the in utero programming of body composition, hepatic function, and hypothalamic development in newborn (P0) offspring. Female mice were fed a low-fat (LF) or high-fat (HF) diet and were mated after 4, 12, and 23 wk. A subset of the obese HF dams was switched to the LF diet during the second (DR2) or third (DR3) pregnancies. The HF offspring accrued more fat mass than the LF pups, regardless of duration of maternal HF diet consumption or prepregnancy maternal adiposity. Increased neonatal adiposity was not observed in the DR3 pups. Liver weights were reduced in the HF offspring but not in the DR2 or DR3 pups. Offspring hepatic triglyceride content was reduced in the HF pups, but hepatic inflammation and expression of lipid metabolism genes were largely unaffected by maternal diet. Maternal diet did not alter the hypothalamic expression of orexigenic and anorexigenic neuropeptides in the offspring. Thus, the intrauterine programming of increased neonatal adiposity and reduced liver size by maternal overnutrition is evident in mice at birth and occurs prior to the development of maternal obesity. These observations demonstrate that dietary intervention during pregnancy minimizes the deleterious effects of maternal obesity on offspring body composition, potentially reducing the offsprings' risk of developing obesity and related diseases later in life.