Short and long-term repercussions of the experimental diabetes in embryofetal development

Effects of diabetes between generations on the pre-embryos of rats

Pregestational hyperglycemia cause adverse effects on mothers and their offspring. We aimed to evaluate the maternal hyperglycemia influence on pre-embryos from diabetic rats and on their generations (daughters and granddaughters). Diabetes was induced in Sprague-Dawley rats. The mothers and their female pups were submitted to oral glucose tolerance test in adulthood. In day 4 of pregnancy, pre-embryos were collected for morphological analysis. The diabetic mother, daughter and granddaughter rats showed glucose intolerance and their pre-embryos presented developmental delay, degeneration and losses compared to the nondiabetic group. Thus, maternal diabetes transgenerationally affects embryos at early development, which contributes for embryofetal losses.

Phytochemical and antidiabetic analysis of Curatella americana L. aqueous extract on the rat pregnancy

ETHNOPHARMACOLOGICAL RELEVANCE

Curatella americana L. is employed in popular medicine for treating diabetes. However, the understanding around its outcomes during pregnancy is unclear.

AIM OF THE STUDY

To evaluate the phytochemical and hypoglycemic analysis of the C. americana extract and its maternal-fetal effect on diabetic rats.

MATERIALS AND METHOD

Diabetes was chemically induced 24 h after birth in Wistar female newborn rats. At adulthood, after diabetes status confirmation, the rats were mated and randomized into four experimental groups: Nondiabetic (Control): given water; Treated: given C. americana extract; Diabetic, and Treated Diabetic rats. The aqueous extract of C. americana leaves (300 mg/kg) was administered daily through oral route during pregnancy. Maternal toxicity and biochemical profile, reproductive outcomes, fetal development, and phenolic composition and biogenic amines in aqueous extract were analyzed.

RESULTS AND CONCLUSION

Phytochemical analysis revealed that the main phenolic components are 3-hydroxytyrosol, kaempferol, and quercetin, while tryptophan and putrescine derivatives were identified as the dominant amines. C. americana extract treatment improved the lipid profile, although no effect on hyperglycemic control in diabetic rats was observed. Maternal diabetes or C. americana extract caused embryo losses confirmed by the lower number of pre-embryos in early pregnancy and higher percentage of abnormal morphologically pre-embryos. C. americana extract previously caused premature pre-embryo fixation before implantation window in nondiabetic and diabetic mothers and intrauterine growth restriction in the fetuses of treated nondiabetic dams, complicating the embryo fetal development. These findings reinforce the caution of indiscriminate use of medicinal plants, especially during pregnancy.

Maternal Diabetes and Postnatal High-Fat Diet on Pregnant Offspring

Maternal diabetes-induced fetal programming predisposes offspring to type 2 diabetes, cardiovascular disease, and obesity in adulthood. However, lifelong health and disease trajectories depend on several factors and nutrition is one of the main ones. We intend to understand the role of maternal diabetes-induced fetal programming and its association with a high-fat diet during lifelong in the female F1 generation focusing on reproductive outcomes and the possible changes in physiological systems during pregnancy as well as the repercussions on the F2 generation at birth. For this, we composed four groups: F1 female pups from control (OC) or from diabetic dams (OD) and fed with standard (SD) or high-fat diet from weaning to full-term pregnancy. During pregnancy, glucose intolerance and insulin sensitivity were evaluated. In a full-term pregnancy, the maternal blood and liver were collected to evaluate redox status markers. The maternal blood, placental tissue, and fetal blood (pool) were collected to evaluate adiponectin and leptin levels. Maternal reproductive parameters were evaluated as well. Maternal diabetes and high-fat diet consumption, in isolation, were both responsible for increased infertility rates and fasting glucose levels in the F1 generation and fetal growth restriction in the F2 generation. The association of both conditions showed, in addition to those, increased lipoperoxidation in maternal erythrocytes, regardless of the increased endogenous antioxidant enzyme activities, glucose intolerance, decreased number of implantation sites and live fetuses, decreased litter, fetal and placental weight, increased preimplantation losses, and increased fetal leptin serum levels. Thus, our findings show that fetal programming caused by maternal diabetes or lifelong high-fat diet consumption leads to similar repercussions in pregnant rats. In addition, the association of both conditions was responsible for glucose intolerance and oxidative stress in the first generation and increased fetal leptin levels in the second generation. Thus, our findings show both the F1 and F2 generations harmed health after maternal hyperglycemic intrauterine environment and exposure to a high-fat diet from weaning until the end of pregnancy.

The role of FGF-4 and FGFR-2 on preimplantation embryo development in experimental maternal diabetes

OBJECTIVE

Diabetes mellitus can cause spontaneous abortion, neonatal diseases, congenital malformations, and death. There are many studies related to the damage of in vitro hyperglycemia on embryogenesis in literature, but not enough studies on in vivo hyperglycemia effects on embryogenesis. Fibroblast growth factor (FGF) molecules play an essential role in pre-implantation embryo development and diabetes pathogenesis. In our study, we researched whether FGF-4 and FGFR-2 were playing a role in maternal diabetes' effects on embryo development.

MATERIAL AND METHODS

Thirty adult virgin female BALB/c mice were randomly divided into two groups: control and diabetic. The experimental diabetes model was generated by streptozotocin (55 mg/kg, once, intraperitoneally). The control and the diabetic group were mated. Embryos were collected at the morula and blastocyte stages corresponding to the third and fourth days of pregnancy. Embryo's FGF-4 and FGFR-2 molecules were evaluated by their immunofluorescence staining and immunoreactivity score.

RESULT

The results clearly showed that the FGF-4 and FGFR-2 immunofluorescence reactivity was higher in the diabetes group.

CONCLUSION

We concluded that FGF-4 and FGFR-2 overexpression might impair mouse pre-implantation embryo development in maternal diabetes and suggest investigating whether they have crucial effects on human embryo development and infertility in maternal diabetes.

Severity of prepregnancy diabetes on the fetal malformations and viability associated with early embryos in rats†

Preexisting/pregestational diabetes enhances the risk of birth defects. Several factors have been involved during the implantation process, such as cytokines (granulocyte-macrophage-colony-stimulating factor [GM-CSF]). The objective was to evaluate the effects of two levels of diabetes on the redox status of preimplantation embryos during the implantation process to comprehend how both are involved in embryo and fetal viability against maternal diabetes. Female Sprague-Dawley rats received streptozotocin at birth (mild diabetes [MD]) or at adulthood (severe diabetes [SD]) to obtain two experimental diabetes intensities. After confirming the diabetic status, the nondiabetic and diabetic groups were mated around day 110 of life. At gestational day (GD) 21, fetuses were assessed for viability and malformations and ovaries for embryo loss before implantation. Other pregnant nondiabetic and diabetic rats were sacrificed at GD2-4 for maternal and preimplantation embryo oxidative stress markers, maternal serum insulin, uterine fluid GM-CSF, and preimplantation embryo morphological analysis. MD and SD caused abnormal redox levels, lower GM-CSF and insulin levels during the preimplantation period, and embryonic loss before implantation. SD caused lower fetal viability and higher fetal malformation percentages at GD21. The SD dam-derived preimplantation embryos presented lower glutathione levels and higher thiobarbituric acid reactive substances concentration at GD3 and an increased frequency of abnormal preimplantation embryos at GD4. In conclusion, preexisting diabetes leads to complications in the implantation process. Furthermore, maternal oxidative stress and other metabolic changes alter the redox state and morphological structure of preimplantation embryos, contributing to damaged growth and development in late pregnancy.

Procyanidin B2 Improves Oocyte Maturation and Subsequent Development in Type 1 Diabetic Mice by Promoting Mitochondrial Function

Type 1 diabetes (T1D) results in decreased oocyte quality and compromised early embryonic development. Procyanidin B2 (PB2) is a natural compound extracted from grape seeds and has strong antioxidant activity in vivo. This study evaluated the effect of PB2 on oocyte maturation in diabetic mice. Diabetic mice were induced by streptozotocin (STZ) injection. PB2 was supplemented in the in vitro maturation medium, and the ratio of germinal vesicle breakdown (GVBD) and polar body extrusion (PBE), reactive oxygen species (ROS) levels, mitochondrial function, developmental ability, as well as crotonylation at H4K5 were determined in oocytes. PB2 can promote the extrusion of PBE (88.34% vs. 75.02%, P < 0.05); reduce the generation of ROS (1.12 vs. 1.96, P < 0.05); and improve the level of mitochondrial membrane potential (0.87 vs. 0.79 Δφm, P < 0.05), ATP level (1.31 vs. 0.71 pmol, P < 0.05), and mitochondria temperature (618.25 vs. 697.39 pixels, P < 0.05). The addition of PB2 also improved the level of oocyte crotonylation at H4K5 (crH4K5) (47.26 vs. 59.68 pixels, P < 0.05) and increased the blastocyst rate (61.51% vs. 36.07%, P < 0.05) after parthenogenetic activation. Our results are the first to reveal a role for PB2 in promoting the viability of oocytes by regulating the mitochondrial function. Moreover, we uncover that PB2 can improve the level of crH4K5, which provides a new strategy to combat the decline in oocyte quality of diabetic.

Lentinus edodes Exposure before and after Fetus Implantation: Materno-Fetal Development in Rats with Gestational Diabetes Mellitus

Background: The presence of β-glucans and phenolic compounds in Lentinus edodes suggests this mushroom can be used as a nutritional supplement. Two gestational conditions (before and after fetus implantation) were evaluated, and Lentinus edodes exposure was performed in diabetes mellitus rat model induced by streptozotocin in pre-clinical tests. Methods: On the 20th day of pregnancy, cesarean sections were performed. Blood was collected for biochemical, hematologic parameters and oxidative stress biomarkers. Placenta and amniotic fluid were collected, and fetuses were analyzed through morphological evaluation. Results: The mushroom did not reduce the severe hyperglycemia of the mother-concept but promoted an increase in maternal insulin levels; reduced the levels of alanine aminotransferase, and aspartate aminotransferase, triglyceride and total cholesterol; protected the animals from post-implantation losses. Liver damage induced by streptozotocin was reversed in experimental groups. Conclusions: Lentinus edodes mushroom has antioxidant properties that can minimize the damage caused by gestational diabetes mellitus.

Pancreatic islet response to diabetes during pregnancy in rats

AIMS

The objective of this study was to assess the mechanisms underlying pancreatic islet adaptation in diabetic mothers and their pups. Additionally, the influence of pancreatic adaptations on maternal reproductive performance was also investigated.

MAIN METHODS

Wistar rats were injected with streptozotocin for diabetes induction. At adulthood (3 months), all animals underwent an oral glucose tolerance test (OGTT) for glucose assessment as an inclusion criterion. Following, the animals were mated. At day 18 of pregnancy, the mothers were killed for blood collect ion to determine fasting insulin and glucagon concentrations. The pancreas was removed and processed for the immunohistochemical analysis of insulin, glucagon, somatostatin, Ki-67 and PDX-1, superoxide dismutase 1 (SOD-1), glutathione peroxidase (GSH-Px) and malondialdehyde (MDA). The pregnant uterus was also collected for the evaluation of embryofetal loss.

KEY FINDINGS

The diabetic rats showed increased glucose, serum glucagon and insulin concentrations, and embryofetal loss rates. They also showed a reduction in pancreatic islets area and percentage of cells stained for insulin, increased the percentage of non-β cells (alpha e delta cells) stained for Ki-67, glucagon, and somatostatin. Moreover, the cells stained for somatostatin were spread across the islets and showed stronger staining for MDA and weaker staining for GSH-Px.

SIGNIFICANCE

Diabetes leads to adaptive responses from the endocrine pancreas in pregnancy that especially involves non-β cells, modifying the mantle-core structure. Nonetheless, these adaptations are not enough for glucose homeostasis and affect the maternal environment, which in turn impairs fetal development.

Streptozotocin-induced diabetes models: pathophysiological mechanisms and fetal outcomes

Glucose homeostasis is controlled by endocrine pancreatic cells, and any pancreatic disturbance can result in diabetes. Because 8% to 12% of diabetic pregnant women present with malformed fetuses, there is great interest in understanding the etiology, pathophysiological mechanisms, and treatment of gestational diabetes. Hyperglycemia enhances the production of reactive oxygen species, leading to oxidative stress, which is involved in diabetic teratogenesis. It has also been suggested that maternal diabetes alters embryonic gene expression, which might cause malformations. Due to ethical issues involving human studies that sometimes have invasive aspects and the multiplicity of uncontrolled variables that can alter the uterine environment during clinical studies, it is necessary to use animal models to better understand diabetic pathophysiology. This review aimed to gather information about pathophysiological mechanisms and fetal outcomes in streptozotocin-induced diabetic rats. To understand the pathophysiological mechanisms and factors involved in diabetes, the use of pancreatic regeneration studies is increasing in an attempt to understand the behavior of pancreatic beta cells. In addition, these studies suggest a new preventive concept as a treatment basis for diabetes, introducing therapeutic efforts to minimize or prevent diabetes-induced oxidative stress, DNA damage, and teratogenesis.