High-energy, sugar-rich diets are associated with obesity and pancreatic disorders. We investigated the effects of consumption of a high-fat and high-fructose diet (HFFrD) on gene expression related to insulin synthesis, inflammation and apoptosis in pancreatic β-cells. Weaned Wistar rats were fed either a control diet (CD; 11 % kcal from fat and 0 % from fructose) or an HFFrD (48 % kcal from fat and 33 % from fructose) for 22 weeks; after a 6-h fast, animals were euthanised. Body weight and total fat were recorded. Serum analyses included: glucose, insulin, triacylglycerides (TAG), malondialdehyde (MDA), TNFα, IL-6, IL-10 and advanced glycation end-products (AGE). Pancreatic islets were analysed for gene expression linked to insulin synthesis, inflammation and apoptosis. Pancreatic assessments included TUNEL assay and immunohistochemistry. HFFrD increased body weight, total fat, MDA, insulin, homeostatic model assessment for insulin resistance, AGE, TAG and IL-6 concentrations in both sexes. Gene expression revealed sex-dependent differences: Glut2, Gck, Khk, Ins2 and the transcription factor Mafa were downregulated in males but upregulated in females. Pdx1 expression increased in females, whereas NeuroD1 increased in males. Pro-inflammatory markers (Il-1β, Il-6) increased in both sexes, whereas Il-10 decreased in males and increased in females. Bax/Bcl2 ratio decreased in males but increased in females; antioxidant and apoptotic markers Nrf2 and Casp3 increased in females. Endocannabinoid receptors (Cnr1, Cnr2) increased in both sexes. HFFrD altered the expression of genes involved in insulin synthesis, inflammation and apoptosis in a sex-specific manner. Compared with males, females showed lower vulnerability, possibly because of adaptive responses in insulin synthesis signalling influenced by sex hormones.

Purpose The contraceptive gestodene is a potent synthetic progestin used in several low-dose contraceptive formulations. Clinical studies reported a relationship between long-term use of combined oral contraceptives containing gestodene (GDN) and profound alterations in glucose metabolism in women. The observation that contraceptive synthetic progestins exert hormone-like effects other than their progestational activities, prompted us to investigate whether GDN may induce estrogen-like effects, even though GDN does not interact with estrogen receptors. The aim of this study was to investigate whether GDN affect pancreatic β-cell activity, directly or through its conversion to other bioactive metabolites. Methods The effects of GDN and its two derivatives 3β,5α-tetrahydro-GDN and 3α,5α-tetrahydro-GDN on insulin 2 ( Ins II ) and glucokinase ( Gk ) expression and glucose-stimulated insulin secretion were determined in pancreatic islets from female rats. Results Gestodene did exert significant effects on islet β-cells activity. The most striking finding was that 3β,5α-tetrahydro-GDN and 3α,5α-tetrahydro-GDN had greater stimulatory effects on Ins II and Gk expression than that observed with GDN, consistent with their effects on glucose-stimulated insulin secretion. The effects on gene expression induced by GDN-derivatives were abolished by ICI 182,780 and MPP. In addition, the presence of inhibitors of androgen and progestin-metabolizing enzymes eliminated gene expression induced by GDN. These results indicated that GDN is metabolized to A-ring reduced metabolites with estrogen-like activities and through this mechanism, GDN may affect β-cell activity. Conclusions Altogether, the data suggest that 19-nortestosterone-derived contraceptives such as GDN, possess insulinotropic effects through their conversion into metabolites with intrinsic estrogen-like activity in pancreatic β-cells.

El aumento de la producción de especies reactivas de oxígeno daña a los islotes pancreáticos por estrés oxidativo y apoptosis en algunos modelos de diabetes en roedores. Se ha observado que la testosterona los protege contra este daño, sin embargo, no se conoce el mecanismo por el cual esta hormona ejerce su protección. El objetivo de este estudio fue evaluar el efecto de la administración de testosterona a ratas macho gonadectomizadas sobre la expresión de las enzimas antioxidantes, superóxido dismutasa dependiente de Mn (MnSOD) y catalasa. La expresión de las enzimas a nivel de la proteína, se estudió por inmunohistoquímica en ratas macho intactas, gonadectomizadas y gonadectomizadas tratadas con testosterona. La expresión del ARNm se analizó por retrotranscripción y reacción en cadena de la polimerasa en tiempo real, en islotes pancreáticos cultivados con testosterona, dihidrotestosterona (DHT) o vehículo. En el caso de la catalasa, el tratamiento con testosterona solamente aumentó la expresión del ARNm. La testosterona indujo la sobreexpresión de la proteína de MnSOD y del ARNm en los islotes pancreáticos a través de un mecanismo no relacionado con la aromatización androgénica, en el que muy probablemente intervienen los receptores de andrógenos, lo que demuestra la participación de la testosterona en la prevención de los daños causados por el estrés oxidativo en las células productoras de insulina.

Maternal nutrition during gestation has important effects on gene expression-mediated metabolic programming in offspring. To evaluate the effect of a protein-restricted maternal diet during gestation, pancreatic islets from male progeny of Wistar rats were studied at postnatal days (PND) 36 (juveniles) and 90 (young adults). The expression of key genes involved in β-cell function and the DNA methylation pattern of the regulatory regions of two such genes, Pdx1 (pancreatic and duodenal homeobox 1) and MafA (musculoaponeurotic fibrosarcoma oncogene family, protein A), were investigated. Gene expression analysis in the pancreatic islets of restricted offspring showed significant differences compared with the control group at PND 36 (P < 0.05). The insulin 1 and 2 (Ins1 and Ins2), Glut2 (glucose transporter 2), Pdx1, MafA, and Atf2 (activating transcription factor 2), genes were upregulated, while glucokinase (Gck) and NeuroD1 (neuronal differentiation 1) were downregulated. Additionally, we studied whether the gene expression differences in Pdx1 and MafA between control and restricted offspring were associated with differential DNA methylation status in their regulatory regions. A decrease in the DNA methylation levels was found in the 5' flanking region between nucleotides -8118 to -7750 of the MafA regulatory region in restricted offspring compared with control pancreatic islets. In conclusion, low protein availability during gestation causes the upregulation of MafA gene expression in pancreatic β-cells in the male juvenile offspring at least in part through DNA hypomethylation. This process may contribute to developmental dysregulation of β-cell function and influence the long-term health of the offspring.

Bisphenol S (BPS) has been introduced into the industry as a safer alternative to bisphenol A (BPA). However, the recent studies have reported a possible association between BPS and disturbed glucose homeostasis, indicating that it may be a risk factor for type 1 and type 2 diabetes mellitus, obesity, and gestational diabetes mellitus. Nevertheless, the role of BPS in glucose metabolism remains controversial. In this study, we investigated the glucose metabolism of male Wistar rats born from dams that were BPS-exposed (groups: BPS-L (0.05 mg/kg/day), BPS-H (20 mg/kg/day)) during pregnancy and lactation. We observed that both BPS treated groups of animals presented a significant decrease in anogenital distance/weight1/3 , as compared to control animals, although no alterations in testosterone levels were observed. Furthermore, the BPS-L group presented a significant decrease in body weight from postnatal day (PND) 21 to adult stage. In addition, a significant increase in glucose tolerance, pancreatic β-cell proliferation, the frequency of small islets, and the average β-cell size at PND 36 was observed in this group. However, no changes in insulin serum levels and percentage of β-cells were recorded. Furthermore, these changes were not preserved at the adult stage (PND 120). The results suggest that the administration of low doses of BPS during the perinatal period induced an estrogenic like effect, with males apparently becoming more female-like in their responses to a glucose challenge.

The aim was to evaluate the effect of perinatal BPA exposure of one or both parents on the implantation index and expression of talin, occludin and E-cadherin in the uterine epithelial cells (UEC) of the offspring. Pregnant Wistar dams (F0) received BPA or vehicle from gestational day (GD) 6 to lactation day 21. F1 animals were mated forming four groups: Control dam-Control sire (C♀-C♂), BPA dam -Control sire (B♀-C♂), Control dam -BPA sire (C♀-B♂), BPA dam -BPA sire (B♀-B♂). F1 dams were sacrificed at GD 6. Significantly decreased number of implantation sites was observed in the B♀-B♂ group as compared to the C♀-C♂ group, which correlated with decreased talin apical/basal expression ratio, occludin apical expression, and E-cadherin apical/lateral expression ratio in the UEC. Furthermore, decreased E-cadherin expression in the blastocyst was observed. Our data suggest that reduced protein expressions in F1 BPA offspring could result from decreased progesterone serum levels.

Parturient rats show a postpartum estrus, a period of sexual receptivity that occurs from 6 to 15 h after the birth of a litter, which allows the mother to gestate a second litter while simultaneously nursing the first one (lactating and pregnant). The present study investigated hormone levels and the expression pattern of estrogen receptor alpha and beta, progesterone receptor isoforms and SRC1 in the hypothalamus and the preoptic area of lactating as well as in lactating-pregnant rats. In the latter, estradiol levels were 3-fold higher than those observed in lactating rats on day 14, meanwhile progesterone levels did not change in any condition. There were higher levels of prolactin in both lactating and lactating-pregnant rats on day 7 and decreased on the following days. In the hypothalamus of the lactating rat, the content of ER alpha increased during lactation meanwhile that of ER beta decreased 50% on day 10. The content of both estrogen receptor subtypes in the hypothalamus increased 3-fold on day 21 in lactating pregnant rats. In the preoptic area, the content of ER alpha was higher in lactating-pregnant rats on days 14 and 21 while the content of progesterone receptor isoforms was lower as compared with those found in lactating animals on days 7 and 10. The content of SRC1 increased 2-fold in the preoptic area only in lactating rats at day 14 and 21. These findings suggest that lactating- pregnant animals should exhibit differential neuroendocrine and molecular characteristics as compared to lactating animals.

Retraction of ‘Alterations in lipid metabolism due to a protein-restricted diet in rats during gestation and/or lactation’ by T. C. Sosa-Larios, et al., Food Funct., 2017, DOI: 10.1039/c7fo01513e.

Perinatal malnutrition affects not only fetal and neonatal growth, but also the health of offspring in adulthood, as suggested by the concept of metabolic programming. The impact of maternal protein malnutrition on the metabolism of offspring is demonstrated with the current data. One group of pregnant/lactating female rats was fed with an isocaloric diet having normal protein content. Three other groups were provided 50% of this protein level during pregnancy and/or lactation. The growth and metabolic state of the offspring was monitored. The expression of genes regulating lipid metabolism was determined, including SREBP-1c and SIRT-1 in liver and retroperitoneal adipose tissue. Blood cholesterol and triglycerides were higher in the adult offspring (at 110 days of age) fed a protein-restricted diet than in the adult offspring fed a normal diet. Protein restriction likely leads to inadequate detection of glucose levels, as suggested by the reduced expression of the gene for GCK, the sensor of glucose in the liver. The effects of a protein-restricted diet were highly dependent on the window in which this limitation occurred. There was a more adverse effect when the rats underwent protein restriction during gestation than lactation, leading to lower body weight and alterations in lipid metabolism in adult offspring.

OBJECTIVE:To design and synthesize an orcinol derivative compound, 3-formyl-2,4-dihydroxy-5,6-dimethyl sodium benzoate (A4), as an antioxidant molecule and to test its effects on oxidative stress in an in-vitro model of apoptosis of pancreatic rat beta cells induced by streptozotocin (STZ).METHODS:Scavenger properties of A4 were assessed using its capacity to capture the DPPH radical in vitro. Antiapoptotic properties of A4 were analysed by electron microscopy and TUNEL assay in rat pancreatic islets in a streptozotocin model.KEY FINDINGS:The results show that A4 displays antioxidant activity in in-vitro assays and induced a significant reduction in STZ-induced beta cell apoptosis and low ultrastructural damage to cellular organelles in the rat pancreatic islets as evidenced by electronic microscopy, this effect could be attributed to its antioxidant activity in a similar manner than resveratrol.CONCLUSION:The overall results indicate that the new orcinol derivative molecule displays both antioxidant and antiapoptotic effects and protect pancreatic beta cells against STZ damage.

Heptachlor has been targeted for global elimination because of its toxicity and environmental persistence, in accordance with the Stockholm Convention on Persistent Organic Pollutants (POPs). However, there is no regulation of heptachlor use in Mexico, where relatively high levels have been found in maternal breast milk. The aim of this study was to determine the effects of heptachlor on the reproductive system of offspring of two consecutive generations of rats (F1 and F2) from dams orally administered heptachlor during midgestation and lactation. Female offspring were analyzed for different phenotypic, reproductive, and molecular parameters. In the F1 generation, heptachlor treatment induced decreased body weight at weaning, increased female anogenital distance, and delayed vaginal opening. In both generations, serum progesterone levels decreased and estradiol levels remained unchanged, while overexpression of the progesterone receptor was observed in uterine epithelial cells on estrus day. In the F2 generation, expression of the estrogen receptor α increased in the glandular epithelium. Finally, heptachlor treatment did not affect apoptosis in the uterine epithelial cells. Overall, the results indicate that heptachlor induced female reproductive alterations when administered to dams during the perinatal period. Accordingly, exposure to heptachlor may represent a risk for the reproductive health of humans. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 856-868, 2017.

We studied the effect of bisphenol-A (BPA) administration to rats, during the perinatal period, on the fertility of F1 generation and on the expression of tight junction (TJ) proteins in the uterus during early pregnancy. Pregnant Wistar dams (F0) received: BPA-L (0.05 mg/kg/day), BPA-H (20 mg/kg/day) or vehicle, from gestational day (GD) 6 to lactation day 21. F1 female pups were mated at 3 months of age and sacrificed at GD 1, 3, 6, and 7. Serum hormonal levels, ovulation rate, number of implantation sites and expression of TJ proteins in the uterus of Fl females were evaluated. BPA treatment induced no change in ovulation rate, but induced alterations in progesterone (P-4) and estradiol (E-2) serum levels, and in implantation rate. With regards to TJ proteins, BPA-H increased claudin-1 during all GDs; eliminated the peaks of claudins -3 and -4 at GD 3 and 6, respectively; and decreased claudin-7 at GD 6, ZO-1 from GD 1-6, and claudin-3 at GD 7 in stromal cells. BPA-L instead, eliminated claudin-3 peak at GD 3, increased claudin-4 and decreased claudin-7 from GD.1-6, decreased claudin-1 at GD 3 and 7 and claudin-4 at GD 7 in stromal cells. BPA-L also decreased ZO-1 at GDs 1 and 3 and increased ZO-1 at GD 6. Thus, BPA treatment during perinatal period perturbed, when the animals reached adulthood and became pregnant, the particular expression of TJ proteins in the uterine epithelium and reduced in consequence the number of implantation sites. (C) 2017 Elsevier Inc. All rights reserved.

Vascular endothelial growth factor (VEGF) is important in the growth and metastasis of cancer cells. In 2001, another angiogenic factor, endocrine gland-derived VEGF (EG-VEGF), was characterized and sequenced. EG-VEGF activity appears to be restricted to endothelial cells derived from endocrine glands. At the molecular level, its expression is regulated by hypoxia and steroid hormones. Although VEGF and EG-VEGF are structurally different, they function in a coordinated fashion. Since the majority of mammary tumors are hormone-dependent, it was hypothesized that EG-VEGF would be expressed in these tumors, and therefore, represent a potential target for anti-angiogenic therapy. The aim of the present study was to assess the expression of VEGF, EG-VEGF and its receptor (prokineticin receptor-1), as well as that of breast cancer resistant protein, estrogen receptor, progesterone receptor and human epidermal growth factor receptor 2, in 50 breast samples of infiltrating canalicular carcinoma (ICC) and their correlation with tumor staging. The samples were analyzed using reverse transcription-quantitative polymerase chain reaction and immunohistochemistry. Both angiogenic growth factors were identified in all samples. However, in 90% of the samples, the expression level of VEGF was significantly higher than that of EG-VEGF (P=0.024). There was no association between the expression of VEGF, EG-VEGF or its receptor with tumor stage. In ICC, the predominant angiogenic factor expressed was VEGF. The expression level of either factor was not correlated with the tumor-node-metastasis stage. Although ICC is derived from endothelial cells, EG-VEGF expression was not the predominant angiogenic/growth factor in ICC.

Maternal obesity (MO) is a deleterious condition that enhances susceptibility of adult offspring to metabolic diseases such as type 2 diabetes. The objective is to study the effect of MO on in vitro insulin secretion and pancreatic cellular population in offspring. We hypothesize that a harmful antenatal metabolic environment due to MO diminishes the basal glucose-responsive secretory function of pancreatic beta cells in offspring. Mothers were fed a control (C) or high-fat diet from weaning through pregnancy (120 days) and lactation. At postnatal days (PNDs) 36 and 110, pups were killed, peripheral blood was collected and pancreatic islets were isolated. Basal insulin secretion was measured in vitro in islets for 60 min. It was found that blood insulin, glucose and homeostasis model assessment (HOMA) index were unaffected by maternal diet and age in females. However, male MO offspring at PND 110 showed hyperinsulinemia and insulin resistance compared with C. Body weight was not modified by MO, but fat content was higher in MO pups compared with C pups. Triglycerides and leptin concentrations were higher in MO than in C offspring in all groups except in females at PND 36. Pancreatic islet cytoarchitecture was unaffected by MO. At PND 36, islets of male and female C and MO offspring responded similarly to glucose, but at PND 110, male and female MO offspring islets showed a 50% decrease in insulin secretion. It was concluded that MO impairs basal insulin secretion of offspring with a greater impact on males than females, and this effect mainly manifests in adulthood.

A maternal low-protein (LP) diet programs fetal pancreatic islet β-cell development and function and predisposes offspring to metabolic dysfunction later in life. We hypothesized that maternal protein restriction during pregnancy differentially alters β- and α-cell populations in offspring by modifying islet ontogeny and function throughout life. We aimed to investigate the effect of an LP maternal diet on pancreatic islet morphology and cellular composition in female offspring on postnatal days (PNDs) 7, 14, 21, 36, and 110. Mothers were divided into 2 groups: during pregnancy, the control group (C) was fed a diet containing 20% casein, and the LP group was fed an isocaloric diet with 10% casein. Offspring pancreases were obtained at each PND and then processed. β and α cells were detected by immunohistochemistry, and cellular area and islet size were quantified. Islet cytoarchitecture and total area were similar in C and LP offspring at all ages studied. At the early ages (PNDs 7-21), the proportion of β cells was lower in LP than C offspring. The proportion of α cells was lower in LP than C offspring on PND 14 and higher on PND 21. The β/α-cell ratio was lower in LP compared with C offspring on PNDs 7 and 21 and higher on PND 36 (being similar on PNDs 14 and 110). We concluded that maternal protein restriction during pregnancy modifies offspring islet cell ontogeny by altering the proportions of islet sizes and by reducing the number of β cells postnatally, which may impact pancreatic function in adult life.

Nutrition during critical periods of development is one of the pivotal factors in establishing a lifelong healthy metabolism. Different nutritional deficiencies such as a low availability of proteins in the maternal diet produce alterations in offspring that include changes in insulin and glucose metabolism, a decrease in the size and number of cells of pancreatic islets of Langerhans, and premature ageing of the secretory function of pancreatic β cells. Moreover, it has been reported that chronic nutritional stress is associated with epigenetic alterations in mechanisms of gene regulation during pancreatic development and function. These alterations can lead to dysfunctional states in pancreatic β cells, which in the long run are responsible for the onset of metabolic diseases like type 2 diabetes. The present review summarizes the most important evidence in relation to the participation of epigenetic mechanisms in the regulation of gene expression during the intrauterine programming of the endocrine pancreas in animal models. Such mechanisms include DNA methylation as well as modifications of histones and microRNAs (miRNAs).

Chronic consumption of high-fat-and-fructose diets (HFFD) is associated with the development of insulin resistance (InsRes) and obesity. Systemic insulin resistance resulting from long-term HFFD feeding has detrimental consequences on cognitive performance, neurogenesis, and long-term potentiation establishment, accompanied by neuronal alterations in the hippocampus. However, diet-induced hippocampal InsRes has not been reported. Therefore, we investigated whether short-term HFFD feeding produced hippocampal insulin signaling alterations associated with neuronal changes in the hippocampus. Rats were fed with a control diet or an HFFD consisting of 10% lard supplemented chow and 20% high-fructose syrup in the drinking water. Our results show that 7 days of HFFD feeding induce obesity and InsRes, associated with the following alterations in the hippocampus: (1) a decreased insulin signaling; (2) a decreased hippocampal weight; (3) a reduction in dendritic arborization in CA1 and microtubule-associated protein 2 (MAP-2) levels; (4) a decreased dendritic spine number in CA1 and synaptophysin content, along with an increase in tau phosphorylation; and finally, (5) an increase in reactive astrocyte associated with microglial changes. To our knowledge, this is the first report addressing hippocampal insulin signaling, as well as morphologic, structural, and functional modifications due to short-term HFFD feeding in the rat.