High-fat feeding reprograms maternal energy metabolism and induces long-term postpartum obesity in mice

Application of Metabolomics and Microbiome Analysis for Revealing the Endogenous Mechanism of Baizhu Xiaozhong San in Postpartum Rats with Spleen-qi Deficiency

Postpartum women are in a state of physical weakness and suffering from fatigue. Metabolic disturbances in the postpartum period may lead to an increased prevalence of postpartum depression, hemorrhage, and obesity, underscoring the importance of prioritizing maternal health. The combination (Baizhu Xiaozhong San, BZXZS) of charred Atractylodis macrocephalae Koidz. (Baizhu, BZ) and charred Fructus Aurantii Immaturus (Zhishi, ZS) has primary applications for invigorating the spleen and promoting diuresis. This study utilized serum/spleen metabolomics in conjunction with 16S rDNA sequencing analysis to investigate the endogenous metabolic alterations and intestinal homeostasis in postpartum rats exhibiting spleen-deficiency syndrome (SDS). The pathological symptoms of postpartum SDS rats in the administration groups were gradually restored, in particular, the symptoms of the BZXZS-H group rats improved significantly. As a result, 32 differential metabolites and 7 correlated metabolic pathways (impact value > 0.1) demonstrated the improvement effect of BZXZS on postpartum SDS rats mostly focusing on disorders of energy, carbohydrate, and lipid metabolism. 16S rDNA gene sequencing indicated that BZXZS had a significantly better regulatory effect on Lactobacillus faecis. The findings suggest that BZXZS exerts a positive impact on the intestinal health and the immune system of postpartum SDS rats through an intricate cascade of interactions with various targets.

Short- and longer-term growth and development of fat mass in preterm infants

Preterm infants typically experience faster growth rates than term-born infants, often doubling their weight in six to eight weeks. However, many face challenges leading to growth faltering and suboptimal neurodevelopment. To achieve optimal growth, these infants often require fortified breastmilk or high-nutrient formula. While meeting nutrition and growth targets are essential, concerns arise about rapid postnatal growth during their catch-up phase, particularly regarding increased body fat at term-corrected age, possibly increasing their risk for obesity and chronic health conditions later. However, evidence suggests that although preterm infants may have higher body fat at term-corrected age, this difference diminishes by three months corrected age, aligning more closely with term-born infants. Systematic reviews of more than 20,000 individuals observed that small for gestational age preterm infants do not have higher adiposity in childhood and adulthood; rather, they exhibit lower body mass indexes, waist circumferences, similar body and visceral fat and blood pressure compared to their appropriate for gestational age preterm-born peers. Therefore, it is reassuring that promoting early growth in preterm infants does not necessitate a trade-off when it comes to supporting long-term metabolic outcomes versus neurodevelopment. Healthcare providers should encourage a responsive feeding approach, even in preterm infants, guided by infants' physiological needs, hunger and satiety once they exhibit feeding cues. This approach respects the child's developmental needs and encourages healthy eating habits, fostering positive parent-child feeding relationships, and ultimately allowing the child to grow and develop to their full potential without compromising their long-term health outcomes.

Influence of Maternal Alpha-Lipoic Acid Supplementation on Postpartum Body Weight and Metabolic Health in Rats with Obesity

We examined the influence of dietary α-lipoic acid (LA; R enantiomer) supplementation in obese-complicated pregnancies on maternal postpartum body weight and metabolic health. Forty-eight female Sprague-Dawley rats were randomized into three dietary groups throughout pre-pregnancy, gestation, and lactation: (i) a low-calorie control diet (CON); (ii) a high calorie obesity-inducing diet (HC); or (iii) the HC diet with 0.25% LA (HC+LA). Following offspring weaning, all mothers were switched to the CON diet for a postpartum period of 140 days to assess maternal body weight and markers of metabolic health. HC-fed mothers showed excessive (p < 0.05) gestational weight gain (GWG), higher (p < 0.05) postpartum body weight, reduced (p < 0.05) glycemic control (lower glucose:insulin ratio) and higher (p = 0.06) hepatic cholesterol concentration versus CON mothers. In contrast, HC+LA mothers demonstrated lower (p < 0.05) body weight throughout the experimental period compared with HC mothers, primarily due to a marked reduction in GWG. Although LA did not protect (p > 0.05) against reduced glycemic control, it did alter several aspects of lipid metabolism including reduced serum HDL-C and a lower concentration of hepatic cholesterol which was mediated partly through a reduction in low-density lipoprotein receptor expression. We conclude that maternal obesity during pregnancy leads to a longer-term detrimental impact on weight gain and glycemic control, even after switching to a low-calorie postpartum diet. Maternal LA supplementation may be able to partially offset these effects, likely by protecting against excessive GWG during pregnancy. However, further work is required to determine the consequences of reduced serum HDL-C in LA-supplemented mothers.

Folic Acid Prevents High-Fat Diet-Induced Postpartum Weight Retention in Rats, Which Is Associated with a Reduction in Endoplasmic Reticulum Stress-Mediated Hepatic Lipogenesis

BACKGROUND

Proactively preventing postpartum weight retention (PPWR) is one of the effective intervention strategies to reduce the occurrence of obesity in women. Population studies have shown that serum folate levels are closely related to body weight. The regulation of folic acid on lipid metabolism has been fully confirmed in both in vivo and in vitro studies. For many years, folic acid supplementation has been widely used in periconceptional women due to its role in preventing fetal neural tube defects. However, whether folic acid supplementation prior to and throughout pregnancy exerts preventive effects on PPWR remains uncertain. This study aims to investigate the preventive effect of folic acid on PPWR in rats and further explore the underlying mechanisms.

METHODS

In this study, pregnant rats were administered one of the dietary schedules: control diet (CON), high-fat diet (HF), control diet combined with folic acid (FA) and high-fat diet combined with folic acid (HF + FA).

RESULTS

We discovered that folic acid supplementation inhibited high-fat diet-induced elevations in body weight, visceral fat weight, liver weight, hepatic lipid levels and serum lipid levels at 1 week post-weaning (PW). Western blot analysis showed that folic acid supplementation inhibited the expression of endoplasmic reticulum (ER) stress-specific proteins including GRP78, PERK, eIF2α, IRE1α, XBP1 and ATF6, subsequently decreasing the expression of proteins related to lipid synthesis including SREBP-1c, ACC1 and FAS.

CONCLUSIONS

In conclusion, folic acid supplementation prior to and throughout pregnancy exerts preventive effects on high-fat diet-induced PPWR in rats, and the mechanism is associated with the inhibition of ER stress-mediated lipogenesis signaling pathways in the liver. Folic acid supplementation may serve as a potential strategy for preventing PPWR. In the future, the effectiveness of folic acid in PPWR prevention can be further verified by population studies.

Taurine supplementation reduces adiposity and hepatic lipid metabolic activity in adult offspring following maternal cafeteria diet

Maternal taurine supplementation has been shown to exert protective effects following a maternal obesogenic diet on offspring growth and metabolism. However, the long-term effects of maternal cafeteria diet on adiposity, metabolic profile, and hepatic gene expression patterns following supplementation of taurine in adult offspring remains unclear. In this study, we hypothesized that exposure to maternal taurine supplementation would modulate the effects of maternal cafeteria diet by reducing adiposity and hepatic gene expression patterns involved in lipid metabolism in adult offspring. Female Wistar rats were fed a control diet, control diet supplemented with 1.5% taurine in drinking water, cafeteria diet (CAF) or CAF supplemented with taurine (CAFT) from weaning. After 8 weeks, all animals were mated and maintained on the same diets during pregnancy and lactation. After weaning, all offspring were fed with control chow diet until the age of 20 weeks. Despite similar body weights, CAFT offspring had significantly lower fat deposition and body fat when compared with CAF offspring. Microarray analysis revealed that genes (Akr1c3, Cyp7a1, Hsd17b6, Cd36, Acsm3, and Aldh1b1) related to steroid hormone biosynthesis, cholesterol metabolism, peroxisome proliferator-activated receptor signaling pathway, butanoate metabolism, and fatty acid degradation were down-regulated in CAFT offspring. The current study shows that exposure to maternal cafeteria diet promoted adiposity and taurine supplementation reduced lipid deposition and in both male and female offspring and led to alterations in hepatic gene expression patterns, reducing the detrimental effects of maternal cafeteria diet.

Estradiol cycling drives female obesogenic adipocyte hyperplasia

White adipose tissue (WAT) distribution is sex dependent. Adipocyte hyperplasia contributes to WAT distribution in mice driven by cues in the tissue microenvironment, with females displaying hyperplasia in subcutaneous and visceral WAT, while males and ovariectomized females have visceral WAT (VWAT)-specific hyperplasia. However, the mechanism underlying sex-specific hyperplasia remains elusive. Here, transcriptome analysis in female mice shows that high-fat diet (HFD) induces estrogen signaling in adipocyte precursor cells (APCs). Analysis of APCs throughout the estrous cycle demonstrates increased proliferation only when proestrus (high estrogen) coincides with the onset of HFD feeding. We further show that estrogen receptor α (ERα) is required for this proliferation and that estradiol treatment at the onset of HFD feeding is sufficient to drive it. This estrous influence on APC proliferation leads to increased obesity driven by adipocyte hyperplasia. These data indicate that estrogen drives ERα-dependent obesogenic adipocyte hyperplasia in females, exacerbating obesity and contributing to the differential fat distribution between the sexes.

Obesogens in Foods

Obesogens, as environmental endocrine-disrupting chemicals, are supposed to have had an impact on the prevalence of rising obesity around the world over the last forty years. These chemicals are probably able to contribute not only to the development of obesity and metabolic disturbances in individuals, but also in their progeny, having the capability to epigenetically reprogram genetically inherited set-up points for body weight and body composition control during critical periods of development, such as fetal, early life, and puberty. In individuals, they may act on myriads of neuro-endocrine–immune metabolic regulatory pathways, leading to pathophysiological consequences in adipogenesis, lipogenesis, lipolysis, immunity, the influencing of central appetite and energy expenditure regulations, changes in gut microbiota–intestine functioning, and many other processes. Evidence-based medical data have recently brought much more convincing data about associations of particular chemicals and the probability of the raised risk of developing obesity. Foods are the main source of obesogens. Some obesogens occur naturally in food, but most are environmental chemicals, entering food as a foreign substance, whether in the form of contaminants or additives, and they are used in a large amount in highly processed food. This review article contributes to a better overview of obesogens, their occurrence in foods, and their impact on the human organism.

Influence of High Energy Diet and Polygenic Predisposition for Obesity on Postpartum Health in Rat Dams

It is estimated that 30% of pregnant women worldwide are overweight or obese, leading to adverse health effects for both mother and child. Women with obesity during pregnancy are at higher risk for developing both metabolic and mental disorders, such as diabetes and depression. Numerous studies have used rodent models of maternal obesity to understand its consequences on the offspring, yet characterization of changes in the dams is rare, and most rodent models rely solely on a high fat diet to induce maternal obesity, without regarding genetic propensity for obesity. Here we present the influence of both peripartum high energy diet (HE) and obesity-proneness on maternal health using selectively bred diet-resistant (DR) and diet-induced obese (DIO) rat dams. Outbred Sprague-Dawley rats were challenged with HE diet prior to mating and bred according to their propensity to gain weight. The original outbred breeding dams (F0) were maintained on low-fat chow during pregnancy and lactation. By comparison, the F1 dams consuming HE diet during pregnancy and lactation displayed higher gestational body weight gain (P < 0.01), and HE diet caused increased meal size and reduced meal frequency (P < 0.001). Sensitivity to the hormone amylin was preserved during pregnancy, regardless of diet. After several rounds of selective breeding, DIO and DR dams from generation F3 were provided chow or HE during pregnancy and lactation and assessed for their postpartum physiology and behaviors. We observed strong diet and phenotype effects on gestational weight gain, with DIO-HE dams gaining 119% more weight than DR-chow (P < 0.001). A high-resolution analysis of maternal behaviors did not detect main effects of diet or phenotype, but a subset of DIO dams showed delayed nursing behavior (P < 0.05). In generation F6/F7 dams, effects on gestational weight gain persisted (P < 0.01), and we observed a main effect of phenotype during a sucrose preference test (P < 0.05), with DIO-chow dams showing lower sucrose preference than DR controls (P < 0.05). Both DIO and DR dams consuming HE diet had hepatic steatosis (P < 0.001) and exhibited reduced leptin sensitivity in the arcuate nucleus (P < 0.001). These data demonstrate that both diet and genetic obesity-proneness have consequences on maternal health.

Adiponectin Promotes Maternal β-Cell Expansion Through Placental Lactogen Expression

Hypoadiponectinemia is a risk factor of gestational diabetes mellitus (GDM). Our previous study reported that adiponectin gene knockout mice (Adipoq ^-/- ) develop GDM due to insulin insufficiency. The main objective of this study was to elucidate the underlying mechanism through which adiponectin controls islet expansion during pregnancy. A significant reduction in β-cell proliferation rates, β-cell areas, and blood insulin concentrations was detected in Adipoq ^-/- mice at midpregnancy. Surprisingly, conditionally knocking down adiponectin receptor 1 (AdipoR1) or AdipoR2 genes in β-cells during pregnancy did not reduce β-cell proliferation rates or blood insulin concentrations. In vitro adiponectin treatment also failed to show any effect on β-cell proliferation of isolated pancreatic islets. It was reported that placental lactogen (PL) plays a crucial role in pregnancy-induced maternal β-cell proliferation. A significant decrease in phosphorylation of signal transducer and activator of transcription 5, a downstream molecule of PL signaling, was observed in islets from Adipoq ^-/- dams. The mRNA levels of mouse PL genes were robustly decreased in the placentas of Adipoq ^-/- dams. In contrast, adiponectin treatment increased PL expression in human placenta explants and JEG3 trophoblast cells. Most importantly, bovine PL injection restored β-cell proliferation and blood insulin concentrations in Adipoq ^-/- dams. Together, these results demonstrate that adiponectin plays a vital role in pregnancy-induced β-cell proliferation by promoting PL expression in trophoblast cells.

Effects of different maternal feeding strategies from day 1 to day 85 of gestation on glucose tolerance and muscle development in both low and normal birth weight piglets

BACKGROUND

Maternal nutrition during gestation plays a vital role in fetal development. The effects of different maternal feeding strategies from day 1 to day 85 of gestation on glucose tolerance and muscle development in low and normal birth weight offspring were investigated by using 80 gilts randomly allotted to T1 and T2 groups and treated respectively with a gradual-increase (T1) and a convex transition (T2) feeding strategy, with no difference in total feed intake.

RESULTS

T2 group was seen to have a higher percentage of piglets with birth weight less than 500 g, while T1 group was shown to have a higher percentage of piglets with birth weight over 700 g. Meanwhile, for both low and normal birth weight piglets, T1 group was higher than T2 group in terms of muscle free amino acid concentration, mRNA expression levels of muscle growth-related factors, relative muscle fiber number and cross-sectional area. We must emphasize that the T2 group was shown to improve glucose tolerance, slow-twitch muscle fiber protein levels, and muscle mitochondrial function only in low birth weight piglets.

CONCLUSION

The convex transition feeding strategy can decrease the percentage of piglets with birth weight over 700 g, while improving glucose tolerance, slow-twitch muscle fiber protein levels, and muscle mitochondrial function in low birth weight piglets. Our findings provide new evidence for the potential importance of nutritional strategies during gestation, especially for improving the glucose tolerance and muscle development of low birth weight neonatal. © 2020 Society of Chemical Industry.

PAPPA-mediated adipose tissue remodeling mitigates insulin resistance and protects against gestational diabetes in mice and humans

Pregnancy is a physiological state of continuous adaptation to changing maternal and fetal nutritional needs, including a reduction of maternal insulin sensitivity allowing for appropriately enhanced glucose availability to the fetus. However, excessive insulin resistance in conjunction with insufficient insulin secretion results in gestational diabetes mellitus (GDM), greatly increasing the risk for pregnancy complications and predisposing both mothers and offspring to future metabolic disease. Here, we report a signaling pathway connecting pregnancy-associated plasma protein A (PAPPA) with adipose tissue expansion in pregnancy. Adipose tissue plays a central role in the regulation of insulin sensitivity, and we show that, in both mice and humans, pregnancy caused remodeling of adipose tissue evidenced by altered adipocyte size, vascularization, and in vitro expansion capacity. PAPPA is known to be a metalloprotease secreted by human placenta that modulates insulin-like growth factor (IGF) bioavailability through prolteolysis of IGF binding proteins (IGFBPs) 2, 4, and 5. We demonstrate that recombinant PAPPA can stimulate ex vivo human adipose tissue expansion in an IGFBP-5- and IGF-1-dependent manner. Moreover, mice lacking PAPPA displayed impaired adipose tissue remodeling, pregnancy-induced insulin resistance, and hepatic steatosis, recapitulating multiple aspects of human GDM. In a cohort of 6361 pregnant women, concentrations of circulating PAPPA are inversely correlated with glycemia and odds of developing GDM. These data identify PAPPA and the IGF signaling pathway as necessary for the regulation of maternal adipose tissue physiology and systemic glucose homeostasis, with consequences for long-term metabolic risk and potential for therapeutic use.

Folic acid content of diet during pregnancy determines post-birth re-set of metabolism in Wistar rat dams

Maternal metabolism begins to return to homeostasis (re-set) following birth and is accelerated by lactation. Delay in metabolic re-set may contribute to postpartum weight retention and later-life metabolic consequences. Folic acid (FA) is essential during pregnancy but inadequate intakes may alter 1-carbon metabolism, consequently affecting energy homeostatic systems. Our objectives were to examine the effects of FA content 1)below and 2)above requirements during pregnancy on the re-set of body weight, markers of hepatic 1-carbon metabolism and central and peripheral energy metabolic pathways in Wistar rat mothers early post-weaning (PW) compared to pregnant controls. Pregnant Wistar rats were fed an AIN-93G diet with FA at 0X, 1X (control, 2 mg FA/kg) or a range above requirements at 2.5X, 5X or 10X recommended levels then the control diet during lactation up to 1 week PW. Dams fed below (0X) or above (5X and 10X) FA requirements had delayed weight-loss from weaning up to 1 week PW, higher plasma insulin and HOMA-IR and changes in glucose and lipid metabolism-regulating genes in muscle, but not liver or adipose tissue compared to controls. Expression of folate-related genes in liver were lower in high FA fed dams. Central food intake neurons were not affected by FA diets. In conclusion, intakes of FA below (0X) or above (5X, 10X) requirements during pregnancy delayed weight-loss, dysregulated 1-carbon pathways in the liver and peripheral energy metabolic pathways in the Wistar rat mother up to 4 weeks after dietary exposure; potentially programming long-term negative metabolic effects and that of her future offspring.

Mitochondrial respiration of adipocytes differentiating from human mesenchymal stem cells derived from adipose tissue

Burden of obesity is increasing in the contemporary world. Although multifactorial in origin, appropriate mitochondrial function of adipocytes emerges as a factor essential for healthy adipocyte differentiation and adipose tissue function. Our study aimed to evaluate mitochondrial functions of human adipose-derived mesenchymal stem cells committed to adipogenesis. On days 0, 4, 10, and 21 of adipogenesis, we have characterized adipocyte proliferation and viability, quantified lipid accumulation in maturing cells, performed qualitative and quantitative analysis of mitochondria, determined mitochondrial respiration of cells using high-resolution respirometry, and evaluated mitochondrial membrane potential. In the course of adipogenesis, mitochondrial oxygen consumption progressively increased in states ROUTINE and E (capacity of the electron transfer system). State LEAK remained constant during first days of adipogenesis and then increased probably reflecting uncoupling ability of maturing adipocytes. Citrate synthase activity and volume of mitochondrial networks increased during differentiation, particularly between days 10 and 21. In addition, lipid accumulation remained low until day 10 and then significantly increased. In conclusion, during first days of adipogenesis, increased mitochondrial respiration is needed for transition of differentiating cells from glycolytic to oxidative metabolism and clonal expansion of preadipocytes and then more energy is needed to acquire typical metabolic phenotype of mature adipocyte.

Maternal obesity impairs fetal mitochondriogenesis and brown adipose tissue development partially via upregulation of miR-204-5p

Maternal obesity (MO) predisposes offspring to metabolic disorders, but the mechanisms remain poorly defined. Recent studies emphasize the importance of brown adipose tissue (BAT) in maintaining metabolic health, and MO was recently demonstrated to impair BAT thermogenic function in offspring. The current study aimed to investigate the mechanisms leading to the impairment in fetal BAT development due to MO. Female C57BL/6J mice were fed a control diet or a 60% high-fat diet for 10 weeks, mated and maintained on their respective diets during pregnancy. Fetal tissue was collected at E18.5, the late stage of pregnancy. Fetal BAT contained more triglycerides compared to the control, which was correlated with higher expression of white adipogenic markers. On the other hand, the expression of BAT markers was down-regulated in the MO fetal BAT. Based on RNA-sequencing analyses, genes related to mitochondriogenesis and myogenesis were found to be down-regulated, while those related to white adipocyte differentiation were up-regulated in MO fetal BAT. Because brown adipocytes are derived from myogenic progenitors, the down-regulation of myogenic genes might partially explain hampered brown adipogenesis in MO fetal BAT. Consistently, mitochondrial DNA and mitochondrial biogenesis markers were also down-regulated in MO fetal BAT. MicroRNA-sequencing identified that miR-204-5p expression was elevated in MO fetal BAT. This microRNA targeted the 3'-untranslated regions of PGC1α and Sirt1 mRNA to suppress their expression and impair mitochondriogenesis. In summary, MO impaired fetal BAT development through suppressing myogenesis and brown adipogenesis while enhancing white adipogenic commitment, and inhibited mitochondriogenesis partially through enhancing miR-204-5p expression.