The impact of maternal consumption of cafeteria diet on reproductive function in the offspring

Maternal high fat diet induces circadian clock-independent endocrine alterations impacting the metabolism of the offspring

Maternal obesity has long-term effects on offspring metabolic health. Among the potential mechanisms, prior research has indicated potential disruptions in circadian rhythms and gut microbiota in the offspring. To challenge this hypothesis, we implemented a maternal high fat diet regimen before and during pregnancy, followed by a standard diet after birth. Our findings confirm that maternal obesity impacts offspring birth weight and glucose and lipid metabolisms. However, we found minimal impact on circadian rhythms and microbiota that are predominantly driven by the feeding/fasting cycle. Notably, maternal obesity altered rhythmic liver gene expression, affecting mitochondrial function and inflammatory response without disrupting the hepatic circadian clock. These changes could be explained by a masculinization of liver gene expression similar to the changes observed in polycystic ovarian syndrome. Intriguingly, such alterations seem to provide the first-generation offspring with a degree of protection against obesity when exposed to a high fat diet.

Intra-uterine programming of future fertility

The developmental origins of health and disease (DOHaD) shows that a relationship exists between parental environment at large, foeto-placental development and the risk for the offspring to develop non-transmittable disease(s) in adulthood. This concept has been validated in both humans and livestock. In mammals, after fertilization and time spent free in the maternal reproductive tract, the embryo develops a placenta that, in close relationship with maternal endometrium, is the organ responsible for exchanges between dam and foetus. Any modification of the maternal environment can lead to adaptive mechanisms affecting placental morphology, blood flow, foetal-maternal exchanges (transporters) and/or endocrine function, ultimately modifying placental efficiency. Among deleterious environments, undernutrition, protein restriction, overnutrition, micronutrient deficiencies and food contaminants can be outlined. When placental adaptive capacities become insufficient, foetal growth and organ formation is no longer optimal, including foetal gonadal formation and maturation, which can affect subsequent offspring fertility. Since epigenetic mechanisms have been shown to be key to foetal programming, epigenetic modifications of the gametes may also occur, leading to inter-generational effects. After briefly describing normal gonadal development in domestic species and inter-species differences, this review highlights the current knowledge on intra-uterine programming of offspring fertility with a focus on domestic animals and underlines the importance to assess transgenerational effects on offspring fertility at a time when new breeding systems are developed to face the current climate changes.

Pancreatic GLUT2 protein expression and isolated islets insulin secretion decreased in high-fat fed rat dams

Purpose

Chronic consumption of high-fat foods during the reproductive period may endanger the dams' metabolic homeostasis and might adversely affect pregnancy outcome. In this regard the present study aimed to investigate the effect of long-term high-fat feeding on pancreatic glucose transporter-2 (GLUT2) protein expression and isolated islets glucose-stimulated insulin secretion in Wistar rat dams.

Materials and methods

Female rats were randomly divided into normal (N) and high-fat (HF; containing cow butter) diet groups and consumed their respective diets for 10 weeks (from prepregnancy to the end of lactation). After lactation, fasting plasma concentrations of glucose and insulin were measured to calculate HOMA-IR index, then intraperitoneal glucose tolerance test (IPGTT) was performed. Moreover, the pancreatic GLUT2 protein expression and insulin secretion from isolated islets at basal (5.6 mM) and stimulated (16.7 mM) glucose concentrations were assessed.

Results

In HF group compared to N group, the plasma insulin level increased, whereas the plasma glucose level did not change in fasting state. Accordingly, the HOMA-IR index increased in HF fed animals. Furthermore, the IPGTT revealed glucose intolerance based on the plasma glucose and insulin results. Also, the pancreatic GLUT2 expression and isolated islets insulin secretion, in response to high glucose concentration, were decreased.

Conclusion

The chronic consumption of high-fat foods during prepregnancy, pregnancy, and lactation periods can lead to glucose intolerance, insulin resistance, and inhibition of pancreatic GLUT2 expression, which impairs glucose homeostasis. Therefore, it is crucial to carefully monitor the diet composition of dams during this critical period.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-023-01274-6.

Maternal cafeteria diet influences kisspeptin (Kiss1), kisspeptin receptor(Gpr54), and sirtuin (Sirt1) genes, hormonal and metabolic profiles, and reproductive functions in rat offspring in a sex-specific manner†

Kisspeptin (KP, encoded by Kiss1, binding to the Gpr54 receptor) is a neuropeptide conveying information on the metabolic status to the hypothalamic-pituitary-gonadal axis. KP acts together with dynorphin A (encoded by Pdyn) and neurokinin B (encoded by Tac2) to regulate reproduction. KP is crucial for the onset of puberty and is under the control of sirtuin (encoded by Sirt1). We hypothesize that the maternal cafeteria (CAF) diet has adverse effects on the offspring's hormonal, metabolic, and reproductive functions due to sex-specific alterations in the expression of Kiss1, Gpr54, Pdyn, Tac2, and Sirt1 in the hypothalamus, and Kiss1, Gpr54, and Sirt1 in the liver. Rats were fed a CAF diet before pregnancy, during pregnancy, and during lactation. The vaginal opening was monitored. Offspring were sacrificed in three age points: PND 30, PND 35, and PND 60 (females) and PND 40, PND 45, and PND 60 (males). Their metabolic and hormonal status was assessed. mRNA for Kiss1, Gpr54, Pdyn, Tac2, and Sirt1 were measured by real-time PCR in the hypothalamus and/or livers. We found that CAF offspring had lower weight and altered body composition; increased cholesterol and triglyceride levels, sex-specific changes in glucose and insulin levels; sex-dependent changes in Sirt1/Kiss1 mRNA ratio in the hypothalamus; sex-specific alterations in Kiss1 and Sirt1 mRNA in the liver with more diversity in males; and a delayed puberty onset in females. We concluded that the mother's CAF diet leads to sex-specific alterations in metabolic and reproductive outcomes via Kiss1/Gpr54 and Sirt1 systems in offspring.

The role of apelinergic system in metabolism and reproductive system in normal and pathological conditions: an overview

Lifestyle changes have made metabolic disorders as one of the major threats to life. Growing evidence demonstrates that obesity and diabetes disrupt the reproductive system by affecting the gonads and the hypothalamus-pituitary-gonadal (HPG) axis. Apelin, an adipocytokine, and its receptor (APJ) are broadly expressed in the hypothalamus nuclei, such as paraventricular and supraoptic, where gonadotropin-releasing hormone (GnRH) is released, and all three lobes of the pituitary, indicating that apelin is involved in the control of reproductive function. Moreover, apelin affects food intake, insulin sensitivity, fluid homeostasis, and glucose and lipid metabolisms. This review outlined the physiological effects of the apelinergic system, the relationship between apelin and metabolic disorders such as diabetes and obesity, as well as the effect of apelin on the reproductive system in both gender. The apelin-APJ system can be considered a potential therapeutic target in the management of obesity-associated metabolic dysfunction and reproductive disorders.

Dietary trends and the decline in male reproductive health

Over the twentieth century, male reproductive health has suffered a substantial decline, as evidenced by decreases in sperm counts and testosterone levels and increases in reproductive pathologies. At the same time, the prevalence of chronic diseases such as obesity, diabetes, and metabolic syndrome has risen dramatically. Metabolic and reproductive health are highly interconnected, suggesting that their respective trends are intertwined and, given the timeframe of such trends, environmental and not genetic factors are most likely to be the primary causes. Industrialization, which began in Europe in the mid-eighteenth century, has resulted in profound changes to our diet, lifestyle, and environment, many of which are causal factors in the rise in chronic diseases. Industrialization results in a nutrition transition from an agricultural unprocessed to a modern processed diet, incorporating increases in sugar, vegetable oils, ultra-processed foods, linoleic acid, trans-fats, and total energy. This dietary shift has incurred numerous adverse effects on metabolic and reproductive health, characterized by chronic inflammation, oxidative stress, and insulin resistance. Moreover, these effects appear to multiply across subsequent generations via epigenetic inheritance. Men's fertility is markedly affected by obesity and diabetes, with an increase in total energy via processed food intake arguably being the key factor driving the diabesity pandemic. In contrast, wholefoods rich in micronutrients and phytonutrients support male fertility and a healthy body weight. Therefore, men wanting to maximize their fertility should consider making positive dietary changes, such as replacing processed foods with unprocessed foods that support metabolic and reproductive health.

Long-term high-fat diet disrupts lipid metabolism and causes inflammation in adult male rats: possible intervention of endoplasmic reticulum stress

This study investigated the effect of long-term high-fat diet (HFD) on plasma lipid profile and probability of inflammation in adult rats. After weaning, male offspring were divided into six groups based on diet type and medication. After 20 weeks of dietary intake, 4-PBA (endoplasmic reticulum (ER) stress inhibitor) was injected for three days. Then, blood samples were taken to measure plasma concentrations of low-density lipoprotein (LDL), triglyceride (TG), high-density lipoprotein (HDL), cholesterol, leptin and interleukin 1-β (IL 1-β). The HFD increased body weight and food intake and intra-abdominal fat and thymus weights, which were associated with elevated plasma leptin level. Moreover, HFD increased plasma concentrations of TG, LDL, cholesterol and IL 1-β and decreased HDL level. Injection of 4-PBA reversed the plasma parameters changes caused by HFD. It seems that long-term HFD feeding through inducing the ER stress, disrupted the lipid metabolism and resulted in inflammation.

Parental High-Fat High-Sugar Diet Intake Programming Inflammatory and Oxidative Parameters of Reproductive Health in Male Offspring

Parental nutrition can impact the health of future generations, programming the offspring for the development of diseases. The developing germ cells of the offspring could be damaged by the maternal or the paternal environment. The germ cells in development and their function could be affected by nutritional adversity and therefore, harm the health of subsequent generations. The paternal or maternal intake of high-fat diets has been shown to affect the reproductive health of male offspring, leading to imbalance in hypothalamic-pituitary-gonadal axis, testicular oxidative stress, low testosterone production, and changes in sperm count, viability, motility, and morphology. There is a need for studies that address the combined effects of diets with a high-fat and high-sugar (H) content by both progenitors on male reproduction. In this context, our study evaluated epigenetic parameters and the inflammatory response that could be associated to oxidative stress in testis and epididymis of adult offspring. 90 days-old male rats were divided according to the combination of the parental diet: CD (control paternal and maternal diet), HP (H paternal diet and control maternal diet), HM (H maternal diet and control paternal diet) and HPM (H paternal and maternal diet).We evaluated serum levels of testosterone and FSH; testicular gene expression of steroidogenic enzymes Star and Hsd17b3 and epigenetic markers Dnmt1, Dnmt3a, Dnmt3b, and Mecp2; testicular and epididymal levels of TNF-α, IL-6, IL-10, and IL-1β; testicular and epididymal activity of SOD, CAT, and GST; the oxidative markers MDA and CP; the daily sperm production, sperm transit time, and sperm morphology. Testicular epigenetic parameter, inflammatory response, oxidative balance, and daily sperm production of the offspring were affected by the maternal diet; paternal diet influenced serum testosterone levels, and lower daily sperm production was exacerbated by the interaction effect of both parental intake of high-fat high-sugar diet in the testis. There was isolated maternal and paternal effect in the antioxidant enzyme activity in the cauda epididymis, and an interaction effect of both parents in protein oxidative marker. Maternal effect could also be observed in cytokine production of cauda epididymis, and no morphological effects were observed in the sperm. The potential programming effects of isolated or combined intake of a high-fat high-sugar diet by the progenitors could be observed at a molecular level in the reproductive health of male offspring in early adulthood.

Early programming of reproductive health and fertility: novel neuroendocrine mechanisms and implications in reproductive medicine

BACKGROUND

According to the Developmental Origins of Health and Disease (DOHaD) hypothesis, environmental changes taking place during early maturational periods may alter normal development and predispose to the occurrence of diverse pathologies later in life. Indeed, adverse conditions during these critical developmental windows of high plasticity have been reported to alter the offspring developmental trajectory, causing permanent functional and structural perturbations that in the long term may enhance disease susceptibility. However, while solid evidence has documented that fluctuations in environmental factors, ranging from nutrient availability to chemicals, in early developmental stages (including the peri-conceptional period) have discernible programming effects that increase vulnerability to develop metabolic perturbations, the impact and eventual mechanisms involved, of such developmental alterations on the reproductive phenotype of offspring have received less attention.

OBJECTIVE AND RATIONALE

This review will summarize recent advances in basic and clinical research that support the concept of DOHaD in the context of the impact of nutritional and hormonal perturbations, occurring during the periconceptional, fetal and early postnatal stages, on different aspects of reproductive function in both sexes. Special emphasis will be given to the effects of early nutritional stress on the timing of puberty and adult gonadotropic function, and to address the underlying neuroendocrine pathways, with particular attention to involvement of the Kiss1 system in these reproductive perturbations. The implications of such phenomena in terms of reproductive medicine will also be considered.

SEARCH METHODS

A comprehensive MEDLINE search, using PubMed as main interface, of research articles and reviews, published mainly between 2006 and 2021, has been carried out. Search was implemented using multiple terms, focusing on clinical and preclinical data from DOHaD studies, addressing periconceptional, gestational and perinatal programming of reproduction. Selected studies addressing early programming of metabolic function have also been considered, when relevant.

OUTCOMES

A solid body of evidence, from clinical and preclinical studies, has documented the impact of nutritional and hormonal fluctuations during the periconceptional, prenatal and early postnatal periods on pubertal maturation, as well as adult gonadotropic function and fertility. Furthermore, exposure to environmental chemicals, such as bisphenol A, and maternal stress has been shown to negatively influence pubertal development and gonadotropic function in adulthood. The underlying neuroendocrine pathways and mechanisms involved have been also addressed, mainly by preclinical studies, which have identified an, as yet incomplete, array of molecular and neurohormonal effectors. These include, prominently, epigenetic regulatory mechanisms and the hypothalamic Kiss1 system, which likely contribute to the generation of reproductive alterations in conditions of early nutritional and/or metabolic stress. In addition to the Kiss1 system, other major hypothalamic regulators of GnRH neurosecretion, such as γ-aminobutyric acid and glutamate, may be targets of developmental programming.

WIDER IMPLICATIONS

This review addresses an underdeveloped area of reproductive biology and medicine that may help to improve our understanding of human reproductive disorders and stresses the importance, and eventual pathogenic impact, of early determinants of puberty, adult reproductive function and fertility.

Dietary interventions in mice affect oxidative stress and gene expression of the Prlr and Esr1 in the adipose tissue and hypothalamus of dams and their offspring

Maternal diet is key to the progeny's health since it may impact on the offspring's adult life. In this study, mice dams received standard (CONT), restrictive (RD), or hypercaloric (HD) diets during mating, pregnancy, and lactation. Male offspring of each group of dams also received these diets: CONT, RD, HD. Aiming to evaluate the oxidative stress in the adipose tissue, reactive oxygen species (ROS) production, catalase (CAT), and superoxide dismutase (SOD) activities were analyzed in dams and offspring. In the adipose tissue and hypothalamus, gene expression of prolactin (Prlr) and estrogen alpha (Esr1) receptors was performed in dams and offspring. Protein expression of Stat5 was evaluated in the adipose tissue of the offspring from RD-fed dams. HD-fed dams increased triglycerides and leptin serum concentrations, and decreased SOD activity in the adipose tissue. In the offspring's adipose tissue, we observed a maternal diet effect caused by HD, with increased ROS production and SOD and CAT activities. Gene expression of Prlr and Esr1 in the offspring's adipose tissue was decreased due to maternal RD. Mice from HD-fed dams showed higher Stat5 expression compared to the offspring from CONT and RD dams in the adipose tissue. In the hypothalamus, we found decreased expression of Prlr in RD and HD dams, compared to CONT; and a maternal diet effect on Prlr and Esr1 gene expression in the offspring. In conclusion, we can affirm that maternal nutrition impacts the redox state and influences the gene expression of Prlr and Esr1, which are involved in energy metabolism, both peripherally and centrally in the adult life of the female offspring.

Animal Foetal Models of Obesity and Diabetes - From Laboratory to Clinical Settings

The prenatal period, during which a fully formed newborn capable of surviving outside its mother's body is built from a single cell, is critical for human development. It is also the time when the foetus is particularly vulnerable to environmental factors, which may modulate the course of its development. Both epidemiological and animal studies have shown that foetal programming of physiological systems may alter the growth and function of organs and lead to pathology in adulthood. Nutrition is a particularly important environmental factor for the pregnant mother as it affects the condition of offspring. Numerous studies have shown that an unbalanced maternal metabolic status (under- or overnutrition) may cause long-lasting physiological and behavioural alterations, resulting in metabolic disorders, such as obesity and type 2 diabetes (T2DM). Various diets are used in laboratory settings in order to induce maternal obesity and metabolic disorders, and to alter the offspring development. The most popular models are: high-fat, high-sugar, high-fat-high-sugar, and cafeteria diets. Maternal undernutrition models are also used, which results in metabolic problems in offspring. Similarly to animal data, human studies have shown the influence of mothers' diets on the development of children. There is a strong link between the maternal diet and the birth weight, metabolic state, changes in the cardiovascular and central nervous system of the offspring. The mechanisms linking impaired foetal development and adult diseases remain under discussion. Epigenetic mechanisms are believed to play a major role in prenatal programming. Additionally, sexually dimorphic effects on offspring are observed. Therefore, further research on both sexes is necessary.

Mothers' cafeteria diet induced sex-specific changes in fat content, metabolic profiles, and inflammation outcomes in rat offspring

“Western diet” containing high concentrations of sugar and fat consumed during pregnancy contributes to development of obesity and diabetes type 2 in offspring. To mimic effects of this diet in animals, a cafeteria (CAF) diet is used. We hypothesized that CAF diet given to rats before, and during pregnancy and lactation differently influences fat content, metabolic and inflammation profiles in offspring. Females were exposed to CAF or control diets before pregnancy, during pregnancy and lactation. At postnatal day 25 (PND 25), body composition, fat contents were measured, and blood was collected for assessment of metabolic and inflammation profiles. We have found that CAF diet lead to sex-specific alterations in offspring. At PND25, CAF offspring had: (1) higher percentage of fat content, and were lighter; (2) sex-specific differences in levels of glucose; (3) higher levels of interleukin 6 (IL-6), interleukin-10 (IL-10) and tumor necrosis factor (TNF-α); (4) sex-specific differences in concentration of IL-6 and TNF-α, with an increase in CAF females; (5) higher level of IL-10 in both sexes, with a more pronounced increase in females. We concluded that maternal CAF diet affects fat content, metabolic profiles, and inflammation parameters in offspring. Above effects are sex-specific, with female offspring being more susceptible to the diet.

Could parental high-fat intake program the reproductive health of male offspring? A review

High-fat diet (HFD) intake can cause overweight and obesity and has become a global public health concern in recent years. Nutritional adversity at vulnerable windows of development can affect developing cells and their functions, including germ cells. Evidence shows that parental HFD intake prior to conception and/or during gestation and lactation could program the reproductive health of male offspring, ultimately resulting in impairment of the first as well as subsequent generations. In male offspring, adipose tissue and hypothalamic-pituitary-gonadal axis imbalance can impair the production of gonadotropins, leading to dysfunction of testosterone production and pubertal onset. The gonads can be directly impaired through oxidative stress, causing poor testosterone production and spermatogenesis; low sperm count, viability, and motility; and abnormal sperm morphology, which results in low sperm quality. Parental HFD intake could also be a risk factor for prostate hyperplasia and cancer in advanced age. It can impact the reproductive pattern of male offspring resulting in impairments in the subsequent generations. The investigation of semen quality must be extended to epidemiological and clinical studies of the male offspring of overweight and/or obese parents in order to improve the quality of human semen. This review addresses the effects of parental HFD intake on the reproductive parameters of male offspring and discusses the possible underlying mechanisms.

Effects of maternal taurine supplementation on maternal dietary intake, plasma metabolites and fetal growth and development in cafeteria diet fed rats

BACKGROUND

Maternal obesity may disrupt the developmental process of the fetus during gestation in rats. Recent evidence suggests that taurine can exert protective role against detrimental influence of obesogenic diets. This study aimed to examine the effect of maternal cafeteria diet and/or taurine supplementation on maternal dietary intake, plasma metabolites, fetal growth and development.

METHODS

Female Wistar rats were fed a control diet (CON), CON supplemented with 1.5% taurine in drinking water (CONT), 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.

RESULTS

Dietary intakes were significantly different between the groups. Both CAF and CAFT fed dams consumed less water in comparison to CON and CONT dams. Taurine supplementation only increased plasma taurine concentrations in CONT group. Maternal plasma adiponectin concentrations increased in CAF and CAFT fed dams compared to CON and CONT fed dams and there was no effect of taurine. Hyperleptinemia was observed in CAF fed dams but not in CAFT fed dams. Malondialdehyde was significantly increased only in CAF fed dams. Litter size, sex ratio and birth weight were similar between the groups. There was an increase in neonatal mortality in CONT group.

DISCUSSION

This study showed that maternal taurine supplementation exerted modest protective effects on cafeteria diet induced maternal obesity. The increased neonatal mortality in CONT neonates indicates possible detrimental effects of taurine supplementation in the setting of normal pregnancy. Therefore, future studies should investigate the optimal dose of taurine supplementation and long term potential effects on the offspring.

The cafeteria diet: A standardized protocol and its effects on behavior

Obesity is a major health risk, with junk food consumption playing a central role in weight gain, because of its high palatability and high-energy nutrients. The Cafeteria (CAF) diet model for animal experiments consists of the same tasty but unhealthy food products that people eat (e.g. hot dogs and muffins), and considers variety, novelty and secondary food features, such as smell and texture. This model, therefore, mimics human eating patterns better than other models. In this paper, we systematically review studies that have used a CAF diet in behavioral experiments and propose a standardized CAF diet protocol. The proposed diet is ad libitum and voluntary; combines different textures, nutrients and tastes, including salty and sweet products; and it is rotated and varied. Our summary of the behavioral effects of CAF diet show that it alters meal patterns, reduces the hedonic value of other rewards, and tends to reduce stress and spatial memory. So far, no clear effects of CAF diet were found on locomotor activity, impulsivity, coping and social behavior.

Resveratrol attenuates metabolic, sperm, and testicular changes in adult Wistar rats fed a diet rich in lipids and simple carbohydrates

High-fat diets affect male reproduction and sexual function. Therefore, we evaluated the effects of prolonged resveratrol administration on the metabolic, sperm, and testicular parameters of rats fed a cafeteria diet. Male Wistar rats were divided at weaning into control (C, n = 20) and cafeteria (CAF, n = 16) groups. At 3 months, half of them were given daily supplementations of resveratrol (C-R, n = 10; CAF-R, n = 8) at a dosage of 30 mg kg^-1 body mass for 2 months. Animals were killed at 5 months of age, and blood, spermatozoa, and testes were collected for further analysis. Data were analyzed by one-way ANOVA, and P < 0.05 was considered statistically significant. The CAF diet promoted hyperglycemia (P < 0.0001), and treatment with resveratrol reversed this condition (P < 0.0001). The CAF diet reduced sperm viability and motility, while resveratrol improved these parameters (P < 0.05). Regarding testicular morphology, the height of the seminiferous epithelium was reduced in the CAF group compared with that of the C group (P = 0.0007). Spermatogenic cell proliferation was also reduced in the CAF group compared with that of the C group. However, the CAF-R showed an increase in cell proliferation rate compared with that of the untreated CAF group (P = 0.0024). Although it did not modify body mass, the consumption of a CAF diet promoted hyperglycemia, adverse testicular morphology remodeling, and abnormal sperm, which were attenuated by treatment with resveratrol, thus suggesting a protective effect of this antioxidant on spermatogenesis.

Impact of maternal overweight on the sexual maturity of male offspring in rats

The aims of the present work were to study the effect of maternal overweight on both the count and quality of sperm of the offspring and to assess whether this maternal condition is able to alter testicular integrity and spermatogenic process. To this end, male offspring from rats fed a standard (OSD) or cafeteria (OCD) diet were used. Body and testis weight, length, preputial separation and ano-genital distance (AGD) were recorded and testes were removed at 60 days of age. In addition, the number of germ, Leydig and Sertoli cells, spermatogenesis and sperm integrity were examined. The OCD rats were divided into two groups: offspring from rats with 25% and≥35% of overweight (OCD25 and OCD35, respectively). Both OCD groups showed higher body and testis weight, higher length, and greater AGD than OSD rats. OCD25 also showed early preputial separation and OCD35 exhibited a high level of testosterone with normal glycemia. Both OCD25 and OCD35 rats had a lower number of spermatozoa and Leydig cells than OSD rats, and OCD35 also exhibited a lower number of spermatogonia and Sertoli cells than OSD rats. In addition, both OCD groups exhibited lower number of sperm cells with normal morphology and sperm motility, and OCD35 showed changes in both the seminiferous epithelium and spermatogenic process. These results suggest that maternal overweight severely affects the reproductive capacity of male offspring, likely leading to a subfertility condition and a premature reduction of the reproductive life span.

Nutritional adversity, sex and reproduction: 30 years of DOHaD and what have we learned?

It is well established that early life environmental signals, including nutrition, set the stage for long-term health and disease risk - effects that span multiple generations. This relationship begins early, in the periconceptional period and extends into embryonic, fetal and early infant phases of life. Now known as the Developmental Origins of Health and Disease (DOHaD), this concept describes the adaptations that a developing organism makes in response to early life cues, resulting in adjustments in homeostatic systems that may prove maladaptive in postnatal life, leading to an increased risk of chronic disease and/or the inheritance of risk factors across generations. Reproductive maturation and function is similarly influenced by early life events. This should not be surprising, since primordial germ cells are established early in life and thus vulnerable to early life adversity. A multitude of 'modifying' cues inducing developmental adaptations have been identified that result in changes in reproductive development and impairments in reproductive function. Many types of nutritional challenges including caloric restriction, macronutrient excess and micronutrient insufficiencies have been shown to induce early life adaptations that produce long-term reproductive dysfunction. Many pathways have been suggested to underpin these associations, including epigenetic reprogramming of germ cells. While the mechanisms still remain to be fully investigated, it is clear that a lifecourse approach to understanding lifetime reproductive function is necessary. Furthermore, investigations of the impacts of early life adversity must be extended to include the paternal environment, especially in epidemiological and clinical studies of offspring reproductive function.

Effect of troxerutin on apelin-13, apelin receptors (APJ), and ovarian histological changes in the offspring of high-fat diet fed rats

OBJECTIVES

Maternal high-fat diet (HFD) consumption has been linked to metabolic disorders and reproductive dysfunctions in offspring. Troxerutin (TRO) has anti-hyperlipidemic, anti-oxidant, and anti-inflammatory effects. This study examined the effects of TRO on apelin-13, its receptors mRNA and ovarian histological changes in the offspring of HFD fed rats.

MATERIALS AND METHODS

Female Wistar rats were randomly divided into control diet (CD) or HFD groups and received these diets for eight weeks. After mating, dams were assigned into four subgroups: CD, CD + TRO, HFD, and HFD + TRO, and received their respective diets until the end of lactation. Troxerutin (150 mg/kg/day) was gavaged in the CD + TRO and HFD + TRO groups during pregnancy. On the postnatal day (PND) 21 all female offspring were separated and fed CD until PND 90. On PND 90 animals were sacrificed and ovarian tissue samples were collected for further evaluation.

RESULTS

Results showed that HFD significantly decreased serum apelin-13 in the female offspring of the HFD dams, which was significantly reversed by TRO. Moreover, real-time polymerase chain reaction (PCR) analysis revealed that TRO treatment significantly decreased the ovarian mRNA expression of the apelin-13 receptor in the troxerutin-received offspring. Furthermore, histological examination revealed that TRO increased the number of atretic follicles in the ovaries of HFD+TRO offspring.

CONCLUSION

Maternal high fat feeding compromises ovarian health including follicular growth and development in the adult offspring and troxerutin treatment improved negative effects of maternal HFD on the apelin-13 level and ovarian development of offspring.

Maternal feeding associated to post-weaning diet affects metabolic and behavioral parameters in female offspring

Genetic and environmental factors related to maternal diet may predispose offspring to serious diseases. However, consequences of a maternal diet intervention during gestation and lactation, and its association with caloric restriction after weaning on the progeny are not completely known. In this context, the goal of the present study was to investigate how different maternal diets, control (CONT), hypercaloric (HD) or restrictive (RD) diets during gestation and lactation, may affect the metabolism and behavior of the offspring that was also submitted to RD. Experimental groups were abbreviated accordingly maternal/offspring diets: CONT/CONT, CONT/RD, RD/CONT, RD/RD, HD/CONT, HD/RD. Our results showed that glucose serum concentration is increased in mice from dams fed a HD. However, offspring from RD-fed dams showed lower insulin and leptin levels than the other groups, indicating a maternal diet effect. Moreover, animals from RD/CONT group showed a higher adipocyte area in comparison to both HD/CONT and CON/CONT. Offspring from RD-fed dams exhibited a decrease in lateral area locomotion in the open field test. Evaluation of anxiety-like behavior and recognition memory showed no significant difference among groups. Thus, maternal RD provides a beneficial response in metabolic parameters, but its effects on behavior is not completely clarified.

Preclinical Models of Altered Early Life Nutrition and Development of Reproductive Disorders in Female Offspring

Early epidemiology studies in humans have and continue to offer valuable insight into the Developmental Origins of Health and Disease (DOHaD) hypothesis, which emphasises the importance of early-life nutritional and environmental changes on the increased risk of metabolic and reproductive disease in later life. Human studies are limited and constrained by a range of factors which do not apply to preclinical research. Animal models therefore offer a unique opportunity to fully investigate the mechanisms associated with developmental programming, helping to elucidate the developmental processes which influence reproductive diseases, and highlight potential biomarkers which can be translated back to the human condition. This review covers the use and limitations of a number of animal models frequently utilised in developmental programming investigations, with an emphasis on dietary manipulations which can lead to reproductive dysfunction in offspring.

Resveratrol Intake During Pregnancy and Lactation Modulates the Early Metabolic Effects of Maternal Nutrition Differently in Male and Female Offspring

Poor maternal nutrition can have detrimental long-term consequences on energy homeostasis in the offspring. Resveratrol exerts antioxidant and antiobesity actions, but its impact during development remains largely unknown. We hypothesized that resveratrol intake during pregnancy and lactation could improve the effects of poor maternal nutrition on offspring metabolism. Wistar rats received a low-fat diet (LFD; 10.2% kcal from fat) or high-fat diet (HFD; 61.6% kcal from fat), with half of each group receiving resveratrol in their drinking water (50 mg/L) during pregnancy and lactation. Body weight (BW) of dams was measured at treatment onset and weaning [postnatal day (PND) 21] and of pups at birth and PND21, at which time dams and pups were euthanized. Although HFD dams consumed more energy, their BW at the end of lactation was unaffected. Mean litter size was not modified by maternal diet or resveratrol. At birth, male offspring from HFD and resveratrol (HFD + R) dams weighed less than those from LFD and resveratrol (LFD + R) dams. On PND21, pups of both sexes from HFD dams weighed more, had more visceral adipose tissue (VAT) and subcutaneous adipose tissue (SCAT), and had higher serum leptin levels than those from LFD dams. Resveratrol reduced BW, leptin, VAT, and SCAT, with females being more affected, but increased glycemia. Neuropeptide levels were unaffected by resveratrol. In conclusion, resveratrol intake during pregnancy and lactation decreased BW and adipose tissue content in offspring of dams on an HFD but did not affect offspring from LFD-fed dams, suggesting that the potential protective effects of resveratrol during gestation/lactation are diet dependent.

Generation of Maternal Obesity Models in Studies of Developmental Programming in Rodents

Mother-child cohort studies have established that both pre-pregnancy body mass index (BMI) and gestational weight gain (GWG) are independently associated with cardio-metabolic risk factors in juvenile and adult offspring, including systolic and diastolic blood pressure. In rodent studies maternal obesity confers many facets of the metabolic syndrome including a persistent sympathy-excitatory hyperresponsiveness and hypertension acquired in the early stages of development. Insight from these animal models raises the possibility that early life exposure to the nutritional and hormonal environment of obesity in pregnancy in humans may lead to early onset of metabolic syndrome and/or essential hypertension. This chapter will address the development of rodent models of maternal overnutrition and obesity, which have proved invaluable in generating testable hypotheses for clinical translation and the development of intervention strategies to stem the swelling tide of obesity and its comorbidities predicted for future generations.

Life-long Maternal Cafeteria Diet Promotes Tissue-Specific Morphological Changes in Male Offspring Adult Rats

Here, we evaluated whether the exposure of rats to a cafeteria diet pre- and/or post-weaning, alters histological characteristics in the White Adipose Tissue (WAT), Brown Adipose Tissue (BAT), and liver of adult male offspring. Female Wistar rats were divided into Control (CTL; fed on standard rodent chow) and Cafeteria (CAF; fed with the cafeteria diet throughout life, including pregnancy and lactation). After birth, only male offspring (F1) were maintained and received the CTL or CAF diets; originating four experimental groups: CTL-CTLF1; CTL-CAFF1; CAF-CTLF1; CAF-CAFF1. Data of biometrics, metabolic parameters, liver, BAT and WAT histology were assessed and integrated using the Principal Component Analysis (PCA). According to PCA analysis worse metabolic and biometric characteristics in adulthood are associated with the post-weaning CAF diet compared to pre and post weaning CAF diet. Thus, the CTL-CAFF1 group showed obesity, higher deposition of fat in the liver and BAT and high fasting plasma levels of glucose, triglycerides and cholesterol. Interestingly, the association between pre and post-weaning CAF diet attenuated the obesity and improved the plasma levels of glucose and triglycerides compared to CTL-CAFF1 without avoiding the higher lipid accumulation in BAT and in liver, suggesting that the impact of maternal CAF diet is tissue-specific.

Role of amygdala kisspeptin in pubertal timing in female rats

To investigate the mechanism by which maternal obesity disrupts reproductive function in offspring, we examined Kiss1 expression in the hypothalamic arcuate (ARC) and anteroventral periventricular (AVPV) nuclei, and posterodorsal medial amygdala (MePD) of pre-pubertal and young adult offspring. Sprague-Dawley rats were fed either a standard or energy-dense diet for six weeks prior to mating and throughout pregnancy and lactation. Male and female offspring were weaned onto normal diet on postnatal day (pnd) 21. Brains were collected on pnd 30 or 100 for qRT-PCR to determine Kiss1 mRNA levels. Maternal obesity increased Kiss1 mRNA expression in the MePD of pre-pubertal male and female offspring, whereas Kiss1 expression was not affected in the ARC or AVPV at this age. Maternal obesity reduced Kiss1 expression in all three brain regions of 3 month old female offspring, but only in MePD of males. The role of MePD kisspeptin on puberty, estrous cyclicity and preovulatory LH surges was assessed directly in a separate group of post-weanling and young adult female rats exposed to a normal diet throughout their life course. Bilateral intra-MePD cannulae connected to osmotic mini-pumps for delivery of kisspeptin receptor antagonist (Peptide 234 for 14 days) were chronically implanted on pnd 21 or 100. Antagonism of MePD kisspeptin delayed puberty onset, disrupted estrous cyclicity and reduced the incidence of LH surges. These data show that the MePD plays a key role in pubertal timing and ovulation and that maternal obesity may act via amygdala kisspeptin signaling to influence reproductive function in the offspring.

Maternal high-fat diet inversely affects insulin sensitivity in dams and young adult male rat offspring

This study attempts to further clarify the potential effects of maternal high-fat (HF) diet on glucose homeostasis in dams and young adult male rat offspring. Female rats were divided into control (CON dams) and HF (HF dams) diet groups, which received the diet 4 weeks prior to and through pregnancy and lactation periods. Blood samples were taken to determine metabolic parameters, then an intraperitoneal glucose tolerance test (IPGTT) was performed. Maternal HF diet increased intra-abdominal fat mass and plasma corticosterone level, but decreased leptin concentration in dams. In HF offspring intra-abdominal fat mass, plasma leptin, and corticosterone levels decreased. Following IPGTT, the plasma insulin level of HF dams was higher than the controls. In HF offspring plasma insulin level was not significantly different from the controls, but a steeper decrease of their plasma glucose concentration was observed.

Little appetite for obesity: meta-analysis of the effects of maternal obesogenic diets on offspring food intake and body mass in rodents

BACKGROUND

There is increasing recognition that maternal effects contribute to variation in individual food intake and metabolism. For example, many experimental studies on model animals have reported the effect of a maternal obesogenic diet during pregnancy on the appetite of offspring. However, the consistency of effects and the causes of variation among studies remain poorly understood.

METHODS

After a systematic search for relevant publications, we selected 53 studies on rats and mice for a meta-analysis. We extracted and analysed data on the differences in food intake and body weight between offspring of dams fed obesogenic diets and dams fed standard diets during gestation. We used meta-regression to study predictors of the strength and direction of the effect sizes.

RESULTS

We found that experimental offspring tended to eat more than control offspring but this difference was small and not statistically significant (0.198, 95% highest posterior density (HPD)=-0.118-0.627). However, offspring from dams on obesogenic diets were significantly heavier than offspring of control dams (0.591, 95% HPD=0.052-1.056). Meta-regression analysis revealed no significant influences of tested predictor variables (for example, use of choice vs no-choice maternal diet, offspring sex) on differences in offspring appetite. Dietary manipulations that extended into lactation had the largest effect on body weight. Subgroup analysis revealed that high protein to non-protein ratio of the maternal diet may promote increased body weight in experimental offspring in comparison with control offspring; low protein content in the maternal chow can have opposite effect.

CONCLUSIONS

Exposure to maternal obesogenic diets in early life is not likely to result in a substantial change in offspring appetite. Nevertheless, we found an effect on offspring body weight, consistent with permanent alterations of offspring metabolism in response to maternal diet. Additionally, it appears that protein content of the obesogenic diet and timing of manipulation modulate the effects on offspring body weight in later life.

Peri-conception parental obesity, reproductive health, and transgenerational impacts

Maternal over-nutrition during pregnancy is a risk factor for pregnancy complications and is increasingly associated with adverse childhood outcomes such as increased propensity for obesity and metabolic disease. However, there is emerging evidence that parental lifestyle factors prior to and at conception have a powerful impact on the health of the offspring for more than one generation. Maternal and paternal obesity prior to conception alters the molecular composition of both oocytes and sperm, which can partly escape epigenetic reprogramming at fertilization, altering the developmental trajectory of the resultant embryo, ultimately increasing the incidence of obesity and metabolic disorders in offspring. Understanding the molecular underpinning of these changes may help create interventions to reduce the risk of disease in future generations.

Epigenetic code and potential epigenetic-based therapies against chronic diseases in developmental origins

Accumulated findings have demonstrated that the epigenetic code provides a potential link between prenatal stress and changes in gene expression that could be involved in the developmental programming of various chronic diseases in later life. Meanwhile, based on the fact that epigenetic modifications are reversible and can be manipulated, this provides a unique chance to develop multiple novel epigenetic-based therapeutic strategies against many chronic diseases in early developmental periods. This article will give a short review of recent findings of prenatal insult-induced epigenetic changes in developmental origins of several chronic diseases, and will attempt to provide an overview of the current epigenetic-based strategies applied in the early prevention, diagnosis and possible therapies for human chronic diseases.