Gestational Diabetes Mellitus Mice Research Articles

N-Acetyl-l-cysteine ameliorates gestational diabetes mellitus by inhibiting oxidative stress

Objective: Gestational diabetes mellitus (GDM) affects 7% of pregnant women worldwide. How to effectively treat GDM has always been a concern of people.Research methods: In this study, a diabetes model was established by drug-induced mice. Subsequently, the blood glucose levels and serum insulin changes of the mice after N-acetyl-l-cysteine (NAC) treatment were observed. At the same time, the effect of NAC on reproduction of GDM mice was recorded.Results of the study: Mice fed NAC showed significantly improved glucose tolerance and insulin sensitivity compared to Diabetic/Control. Total serum cholesterol, serum triglycerides, and serum low-density lipoprotein were significantly reduced, and atherosclerosis index was much lower than in control mice. In addition, Diabetic/Control mice had lower litter sizes and higher birth weights. NAC treatment significantly restored litter size and reduced birth weight in Diabetic/Control mice. It was found in WB assay that the NAC-fed group significantly increased nuclear Nrf2 and HO-1 expression levels.Conclusion: NAC can improve blood glucose tolerance in GDM mice; NAC effectively relieves the symptoms of hyperlipidemia caused by GDM; NAC enhances the expression of Nrf2/HO-1 in the liver, thereby restoring redox homeostasis. NAC can reduce gestational diabetes-related disease indicators by oral administration, and has a beneficial effect on the offspring of pregnant mice (reduces its diabetes disease indicators).

Vitamin E Supplement Protects Against Gestational Diabetes Mellitus in Mice Through nuclear factor-erythroid factor 2-related factor 2/heme oxygenase-1 Signaling Pathway.

Gestational diabetes mellitus (GDM) is the most common pregnant disorder worldwide. In this study, we aimed to explore whether vitamin E (VE) treatment alone could protect against GDM in a mouse model. 6-week-old C57BL/6J female mice were fed on high-fat diet for two weeks and continued with high-fat diet after pregnancy to induce GDM. The pregnant mice were orally administrated with 2.5, 25 or 250 mg/kg VE twice per day during pregnancy together with high-fat diet. Oral glucose tolerance test, insulin amounts, oxidative stress and inflammation were then measured. Only 250 mg/kg VE could improve glucose tolerance and insulin level in pregnant mice. VE (250 mg/kg) effectively inhibited GDM-induced hyperlipidemia, and secretion of inflammatory cytokines such as tumor necrosis factor-α and interleukin-6. VE also significantly ameliorated maternal oxidative stress at the late stage of pregnancy, and also improved reproductive outcomes, including increasing the litter size and birth weight in GDM mice. Moreover, VE also activated GDM-reduced nuclear factor-erythroid factor 2-related factor 2 (Nrf2) / heme oxygenase-1 signaling pathway in the maternal liver tissues of GDM mice. Our data clearly demonstrated that 250 mg/kg VE twice a day during pregnancy could significantly ameliorate the symptoms of GDM by alleviating oxidative stress, inflammation, hyperglycemia, and hyperlipidemia through Nrf2/HO-1 signaling pathway in GDM mice. Thus, additional VE supplement might be beneficial to GDM.

Long Non-Coding RNA TUG1 Attenuates Insulin Resistance in Mice with Gestational Diabetes Mellitus via Regulation of the MicroRNA-328-3p/SREBP-2/ERK Axis.

Long non-coding RNAs (lncRNAs) have been illustrated to contribute to the development of gestational diabetes mellitus (GDM). In the present study, we aimed to elucidate how lncRNA taurine upregulated gene 1 (TUG1) influences insulin resistance (IR) in a high-fat diet (HFD)-induced mouse model of GDM. We initially developed a mouse model of HFD-induced GDM, from which islet tissues were collected for RNA and protein extraction. Interactions among lncRNA TUG1/microRNA (miR)-328-3p/sterol regulatory element binding protein 2 (SREBP-2) were assessed by dual-luciferase reporter assay. Fasting blood glucose (FBG), fasting insulin (FINS), homeostasis model assessment of insulin resistance (HOMA-IR), HOMA pancreatic β-cell function (HOMA-β), insulin sensitivity index for oral glucose tolerance tests (ISOGTT) and insulinogenic index (IGI) levels in mouse serum were measured through conducting gain- and loss-of-function experiments. Abundant expression of miR-328 and deficient expression of lncRNA TUG1 and SREBP-2 were characterized in the islet tissues of mice with HFD-induced GDM. LncRNA TUG1 competitively bound to miR-328-3p, which specifically targeted SREBP-2. Either depletion of miR-328-3p or restoration of lncRNA TUG1 and SREBP-2 reduced the FBG, FINS, HOMA-β, and HOMA-IR levels while increasing ISOGTT and IGI levels, promoting the expression of the extracellular signal-regulated kinase (ERK) signaling pathway-related genes, and inhibiting apoptosis of islet cells in GDM mice. Upregulation miR-328-3p reversed the alleviative effects of SREBP-2 and lncRNA TUG1 on IR. Our study provides evidence that the lncRNA TUG1 may prevent IR following GDM through competitively binding to miR-328-3p and promoting the SREBP-2-mediated ERK signaling pathway inactivation.

LncRNA XIST promotes insulin resistance in gestational diabetes mellitus via the microRNA-181b-5p/NDRG2 axis.

Many studies have explored the role of lncRNA X inactivation-specific transcript (XIST) in diabetes. This study was designed to unravel the regulatory mechanism of XIST on animal models of gestational diabetes mellitus (GDM) progression via the microRNA (miR)-181b-5p/N-myc downstream-regulated gene 2 (NDRG2) axis. XIST, miR-181b-5p, and NDRG2 expression levels in GDM mice were detected. The GDM mice were subjected to gain- and loss-of-function assays to examine the change of glucose metabolism indices (fasting blood glucose (FBG), fasting insulin (FINS) and homeostasis model assessment of insulin resistance (HOMA-IR)), serum oxidative stress factors (glutathione (GSH), superoxide dismutase (SOD), and malondialdehyde (MDA)), serum inflammatory factors (interleukin-1 β (IL-1β), IL-6, and tumor necrosis factor α (TNF-α)), pathological changes of pancreatic tissues, and apoptotic cells in pancreatic islets in GDM mice. XIST and NDRG2 expression were elevated while miR-181b-5p expression was depleted in GDM mice. Down-regulated XIST or NDRG2 or up-regulated miR-181b-5p reduced the FBG level, HOMA-IR, and serum IL-1β, IL-6, and TNF-α, and MDA contents, elevated the FINS, GSH, and SOD level, mitigated pathological changes in pancreatic tissues, and decelerated apoptotic cells in pancreatic islets in GDM mice. Silenced XIST dampens insulin resistance in GDM mice via the modulation of the miR-181b-5p/NDRG2 axis.

Polyphyllin I alleviates inflammatory injury in mice with gestational diabetes through AMPK pathway

Our study aimed to detect the effects of polyphyllin I (PPI) on relieving gestational diabetes mellitus (GDM), and the possible mechanism. A mouse model of GDM was constructed. The effects of PPI on GDM mice were evaluated by detecting blood glucose, insulin level, glucose tolerance test, and insulin tolerance test. The inflammation response in GDM and GDM+PPI group were evaluated by enzyme-linked immunosorbent assay (ELISA). The effect of PPI on the offspring of GDM mice was analyzed. In addition, immunoblot assays were performed to investigate the effects of PPI on the AMPK pathway. We found that PPI improved diabetes-related symptoms and decreased serum inflammatory response in GDM mice. In addition, we also found that PPI reduced the tissue damage of GDM mice. We noticed that PPI alleviated inflammatory injury in GDM mice through targeting AMPK pathway. Our findings showed that PPI has the potential to be explored as the drug for GDM treatment.

N-acetyl-L-cysteine ameliorates gestational diabetes mellitus by inhibiting oxidative stress.

Gestational diabetes mellitus (GDM) is a common pregnant disorder that needs careful medical attention. N-acetyl-L-cysteine (NAC) is a well-recognized antioxidant to treat oxidative stress-induced diseases. Although its role in GDM has been reported, the mechanism remains largely unknown. Therefore, our current study further explored its protective role against GDM. An 8-week-old, db/+, female mice were injected with a single dose of 100mg/kg streptozotocin (STZ) to induce diabetes. Pregnant mice were randomly treated with 1200mg/kg NAC or water daily. On gestational day 19, oral glucose tolerance test was performed, and visceral fat tissue and blood samples were collected. After delivery, litter size and weight were recorded. NAC could effectively improve GDM-induced glucose intolerance, hyperlipidemia, activated inflammation, and oxidative stress in GDM mice. Moreover, NAC reduced the litter size and weight of GDM mice. NAC also activated the nuclear factor-erythroid factor 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling pathway in the liver of GDM mice. NAC effectively ameliorated GDM symptoms and the reproductive outcome of GDM mice through inhibiting oxidative stress, inflammation, and hyperlipidemia. Therefore, NAC might serve as a potential candidate drug against GDM.

Probiotics alleviate maternal metabolic disorders and offspring-islet abnormalities in gestational diabetic mice

• The islets of the GDM offspring mice show a “pre-mature” state at birth. • BiLaEn can avoid the excessive development of islets in GDM offspring mice. • The mTORC1 signaling in islets of GDM mice is not synchronized with normal. Gestational diabetes mellitus (GDM) amplifies the intergenerational risk for early-onset metabolic diseases in offspring, yet the pathogenesis remains unclear. We investigated the impacts of GDM on islets development and maturation in offspring mice and whether probiotics (BiLaEn) have protective effects. Strikingly, GDM caused abnormal prenatal development of islets in offspring mice, with abnormally high-expression insulin and glucagon at birth, showing premature or quasi-mature state; the process of β-cell maturation and mTORC1 signalling were not synchronized with normal offspring mice within 14 days after birth. Furthermore, BiLaEn treatment benefited the normal development and maturation of GDM-offspring islets, avoiding “quasi-mature” at birth, which were based on the improvement of intestinal flora disturbance and leaky gut in GDM maternal mice. These data highlight the premature development of GDM-offspring islets as potential cause of early-onset metabolic diseases in GDM offspring, and targeted regulation of intestinal flora is expected to be safe and effective intervention.

Dysregulation of Mir-193B and Mir-376A as a Biomarker of Prediabetes in Offspring of Gestational Diabetic Mice

Gestational diabetes mellitus (GDM) is a type of diabetes initiated during pregnancy and is characterized by maternal hyperglycemia that induces complications in mothers and children. In the current study, we used a GDM mouse model (through i.p. injection of a single dose of streptozocin, STZ, 60 mg/kg/bw) to investigate the biochemical and immunological changes in the blood and brain of diabetic mothers and their offspring relative to their appropriate controls. In addition, we estimated the expression levels of a set of microRNAs (miRNAs) to link between the dysregulation in the levels of miRNAs and the exposure to oxidative stress during embryonic development, as well as metabolic changes that occur after birth and during puberty in offspring (5-weeks-old). At the biochemical level, newborn pups appeared mostly to suffer from the same oxidative stress conditions of their mothers as shown by the significant increase in nitric oxide (NO) and malondialdehyde (MDA) in blood and brain of diabetic mothers and their pups. However, the 5-week-old offspring showed a significant increase in proinflammatory cytokines, IL-1β, IL-6, and TNF-α, and based on their blood glucose levels, could be considered as prediabetic (with glucose mean value of 165 mg/dl). In the meantime, the tested miRNAs, especially miR-15b, miR-146a, and miR-138 showed mostly similar expression levels in diabetic mothers and newborn pups. In this regard, miR-15a and -15b, miR-146a, and miR-138 are downregulated in diabetic mothers and their newborn pups relative to their appropriate controls. However, in offspring of diabetic mothers at puberty age, these miRNAs displayed different expression levels relative to mothers and control offspring. Interestingly, miR-193 and miR-763 expression levels were significantly lower in diabetic mothers but upregulated in their 5-week-old offspring, suggesting that miR-193 and miR-763 could be used as biomarkers to differentiate between prediabetes and diabetes.

β-Carotene regulates glucose transport and insulin resistance in gestational diabetes mellitus by increasing the expression of SHBG.

The aim of this work was to study the effect and mechanism of β-carotene on insulin resistance and glucose transport in gestational diabetes mellitus (GDM). Placental tissue and venous blood of 26 GDM patients and 18 normal women were collected. Mice fed a high-fat diet were established as GDM models and treated with β-carotene, from which peripheral blood and placenta tissue were collected. HTR-8/SVneo cells were treated with 10-7 mol/L insulin for 48 h and established as insulin resistance cell models. The expression of SHBG, GLUT1, GLUT3, GLUT4, IRS-1, IRS-2, PI3Kp85α, and p-CREB/CREB in placental tissues and HTR-8/SVneo cells was detected. Insulin resistance index was calculated from the values of fasting blood glucose and fasting insulin. The glucose consumption of insulin-resistant cells was calculated by detecting the glucose content of the supernatant. The cyclic adenosine monophosphate (cAMP) kit was applied to measure the concentration of cAMP in cells. SHBG was lowly expressed in GDM. β-Carotene treatment upregulated SHBG in the placenta of GDM mice and in insulin-resistant HTR-8/SVneo cells. Overexpression of SHBG upregulated GLUT3, GLUT4, and IRS-1 and enhanced glucose consumption in insulin-resistant cells. β-Carotene treatment promoted the expression of SHBG, GLUT4 and IRS-1 and increased glucose consumption in insulin-resistant cells underexpressing SHBG. Silencing of SHBG decreased the levels of cAMP and pCREB/CREB but β-carotene treatment increased their expression despite SHBG silencing in insulin-resistant cells. β-Carotene promotes glucose transport and inhibits insulin resistance in GDM by increasing the expression of SHBG.

Orphan nuclear receptor NUR77 relieves insulin resistance in HTR-8/SVneo trophoblast cells through activation of autophagy and insulin signaling.

Gestational diabetes mellitus (GDM) is a common pregnancy complication with a high incidence in women. Orphan nuclear receptor NUR77 is involved in regulating glucose metabolism. However, its role in GDM has not been fully elucidated yet. In this study, an animal model of GDM was established by feeding mice with a high-fat diet (HFD) before and during pregnancy. NUR77 expression was abnormally upregulated in placenta tissues of GDM mice. We performed gain- and loss-of-function studies of NUR77 in HTR-8/SVneo cells. Cells were incubated with 1 × 10-6M insulin for 48h to induce insulin resistance (IR). The expression of NUR77 was downregulated in HTR-8/SVneo cells following IR induction. Overexpression of NUR77 promoted cell proliferation, migration, and invasion. Notably, NUR77 promoted glucose uptake and enhanced insulin sensitivity in vitro. NUR77 increased the ratio of p-insulin receptor β (IRβ)Tyr1361/IRβ, p-insulin receptor substrate (IRS)-1Tyr612/IRS-1, p-Akt/Akt and decreased p-IRS-1Ser307/IRS-1, as well as lowered the expression of glucose transport protein type 1 (GLUT1) and elevated GLUT4. These results suggest the involvement of IRβ/IRS/Akt/GLUT4 signaling activation in the regulatory effects of NUR77 on IR in HTR-8/SVneo cells. Silencing of NUR77 displayed opposite effects. Besides, NUR77 enhanced the expression of autophagy-related protein Beclin 1 and the ratio of LC3II/LC3I. Further study demonstrated that the inhibitory effect of NUR77 on IR was partially attributed to the activation of autophagy. Therefore, we demonstrate that NUR77 enhances insulin sensitivity in HTR-8/SVneo cells likely through activating IRβ/IRS/Akt/GLUT4 pathway and regulating autophagy.

Exosomal Circular RNA hsa_circ_0046060 of Umbilical Cord Mesenchymal Stromal Cell Ameliorates Glucose Metabolism and Insulin Resistance in Gestational Diabetes Mellitus via the miR-338-3p/G6PC2 Axis.

Background Impaired glucose metabolism and insulin sensitivity have been linked to the pathogenesis of gestational diabetes mellitus (GDM). Exosomes secreted by the umbilical cord mesenchymal stromal cells (UMSCs) and circular RNAs (circRNAs) derived from exosomes have been shown to be associated with the progression of GDM-related complications. Methods UMSCs were isolated from umbilical cords and identified through flow cytometry. Exosomes were isolated from UMSCs and were then characterized. The expression levels of RNA of hsa_circ_0046060, mmu_circ_0002819, and miR-338-3p were determined by quantitative real-time polymerase chain reaction (RT-qPCR). The intracellular glucose intake and glycogen content were measured using a High Sensitivity Glucose Assay Kit and Glycogen Assay Kit, respectively. Bioinformatics analysis and luciferase reporter assay were used to validate interactions among hsa_circ_0046060, miR-338-3p, and G6PC2. The expression of insulin receptor substrate-1 (IRS-1) and its phosphorylated form, (p-IRS-1), as well as G6PC2, was determined through western blotting. Results UMSCs and exosomes were successfully isolated and identified. The upregulation of hsa_circ_0046060 decreased the intracellular glucose content in L-02 cells (43.45 vs. 16.87 pM/mg, P=0.0002), whereas shRNA-mediated downregulation reversed this effect (16.87 vs. 33.16 pM/mg, P=0.0011). Mmu_circ_0002819 in mice aggravated dysregulated glucose metabolism (49.88 vs. 21.69 pM/mg, P=0.0031) and insulin sensitivity (0.20 vs. 0.11 mg/mL, P=0.03) in GDM mice, which was abrogated by the knockdown of mmu_circ_0002819. The results of luciferase reporter assay revealed that miR-338-3p and G6PC2 were the potential targets of has_circ_0046060. Western blotting results showed that the reduced activation of IRS-1 induced by GDM (1.25 vs. 0.54, P=0.0001) could be rescued by the administration of si-circ-G-UMSC-EXOs (0.54 vs. 1.17, P=0.0001). Conclusion Taken together, the inhibition of hsa_circ_0046060 expression in exosomes from GDM-derived UMSCs can alleviate GDM by reversing abnormal glucose metabolism and insulin resistance in vivo and in vitro.

Human placenta mesenchymal stem cell-derived exosome shuttling microRNA-130b-3p from gestational diabetes mellitus patients targets ICAM-1 and perturbs human umbilical vein endothelial cell angiogenesis.

The aim of this study was to investigate the roles of miR-130b-3p and ICAM-1 in gestational diabetes mellitus (GDM) and their potential association. Human placenta mesenchymal stem cells (PlaMSCs) were isolated from GDM patients, and the effects of the PlaMSCs from GDM patients (GDM-MSCs) and the exosomes secreted by GDM-MSCs on human umbilical vein endothelial cell (HUVEC) proliferation, migration, and angiogenesis were detected. Next, GDM-MSCs were transfected with miR-130b-3p antagomir to modify miR-130b-3p expression in GDM-MSCs-derived exosomes, and the exosomes with modified miR-130b-3p expression were cultured with HUVECs to evaluate exosomal miR-130b-3p on HUVEC function. Furthermore, a target gene of miR-130b-3p was predicted and assessed. The miR-130b-3p-modified exosomes were cultured with HUVECs transfected with ICAM-1 shRNA to determine the effect of miR-130b-3p-ICAM-1 crosstalk on HUVEC function. Additionally, a GDM mouse model was conducted to further study the effect of miR-130b-3p in GDM in vivo. GDM-MSCs inhibited HUVEC proliferation and angiogenesis. The elevated expression of miR-130b-3p was found in GDM-MSCs-derived exosomes. GDM-MSCs-derived exosomes repressed the proliferation and angiogenesis of HUVECs and miR-130b-3p inhibition could restrain the inhibition of the exosomes on HUVEC function. Mechanistically, miR-130b-3p downregulated ICAM-1 expression in a targeted manner, and thereby enhanced HUVEC proliferation, migration, and angiogenesis and increased the expression of angiogenesis-related factors. Moreover, miR-130b-3p inhibition promoted placental angiogenesis in GDM mice and upregulated ICAM-1 expression. Conclusively, GDM-MSCs-derived exosomes shuttling miR-130b-3p repressed proliferation, migration, and angiogenesis of HUVECs by regulating ICAM-1 expression.

Procyanidins and its metabolites by gut microbiome improves insulin resistance in gestational diabetes mellitus mice model via regulating NF-κB and NLRP3 inflammasome pathway

Gestational Diabetes Mellitus (GDM) has an effect on the health of pregnant women and fetuses. Procyanidins (PA) is a flavonoid with anti-diabetic activity, but its effects and mechanisms on GDM have not been defined. Herein, we studied further the functions and mechanisms of PA on insulin resistance (IR) in GDM mice, as well as on postpartum and offspring mice. GDM mice model was built by feeding a high-fat-high-sucrose diet, and PA intervention (27.8 mg/kg/d) was performed from 4 weeks before pregnancy to delivery. Intestinal flora deficient (IFD) mice model was established by broad spectrum antibiotics. PA decreased the gestational weight gain, and the levels of fasting blood glucose, insulin, homeostasis model of assessment for IR index, yet increased the levels of HOMA for insulin sensitivity index. Interestingly, in IFD mice the effect of PA on improving IR was significantly weakened. PA inhibited inflammation by decreasing the levels of IL-6, TNF-α, IL-17 and CRP, which also been blocked in the IFD mice. Moreover, PA improved glycometabolism and reduced the secretion of inflammatory factors and hepatic inflammation infiltration of mice at 4 weeks postpartum, but had no significant effect on offspring mice. Mechanistically, PA treatment suppressed the nuclear factor‐κB (NF‐κB) p65 nuclear translocation and nucleotide‐binding domain like receptor protein 3 (NLRP3) inflammasome activation. In vitro studies, 4-hydroxyphenylacetic acid and 3-(4-hydroxyphenyl) propionic acid, main intestinal flora metabolites of PA restrained NF‐κB/NLRP3 activation. In conclusions, PA improved IR via NF-κB/NLRP3 pathway in GDM and postpartum mice, which partly through its metabolites by gut microbiome.

Gestational Diabetes Sensitizes Mice to Future Metabolic Syndrome That Can Be Relieved by Activating CAR.

Diabetes and related metabolic syndrome are common metabolic disorders. Gestational diabetes mellitus (GDM) is rather prevalent in the clinic. Although most GDM resolves after therapeutic intervention and/or after delivery, the long-term health effect of GDM remains to be better understood. The constitutive androstane receptor (CAR), initially characterized as a xenobiotic receptor, was more recently proposed to be a therapeutic target for obesity and type 2 diabetes mellitus (T2DM). In this study, high-fat diet (HFD) feeding was used to induce GDM. Upon delivery, GDM mice were returned to chow diet until the metabolic parameters were normalized. Parous non-GDM control females or metabolically normalized GDM females were then subjected to HFD feeding to induce nongestational obesity and T2DM. Our results showed that GDM sensitized mice to metabolic abnormalities induced by a second hit of HFD. Treatment with the CAR agonist 1,4-bis [2-(3,5 dichloropyridyloxy)] benzene efficiently attenuated GDM-sensitized and HFD-induced obesity and T2DM, including decreased body weight, improved insulin sensitivity, inhibition of hyperglycemia and hepatic steatosis, increased oxygen consumption, and decreased adipocyte hypertrophy. In conclusion, our results have established GDM as a key risk factor for the future development of metabolic disease. We also propose that CAR is a therapeutic target for the management of metabolic disease sensitized by GDM.

Long-noncoding RNA HOXA transcript at the distal tip ameliorates the insulin resistance and hepatic gluconeogenesis in mice with gestational diabetes mellitus via the microRNA-423-5p/wingless-type MMTV integration site family member 7A axis

ABSTRACT Long-noncoding RNA HOXA transcript at the distal tip (HOTTIP) has been probed to exert essential effects on diabetes progression, while its function in gestational diabetes mellitus (GDM) remains unclear. This study was committed to unravel the effects of HOTTIP on GDM progression via the microRNA (miR)-423-5p/wingless-type MMTV integration site family member 7A (WNT7A) axis. The GDM mouse model was established. HOTTIP, miR-423-5p and WNT7A levels in GDM mice were examined. The saline with dissolved various constructs altering HOTTIP, miR-423-5p and WNT7A expression was injected into GDM mice to detect the levels of GDM‐related biochemical indices, HOMA indices, liver gluconease: expression levels of phosphoenolpyruvate carboxykinase (PEPCK), glucose-6-phosphatase (G-6-Pase), glucose transporter 2 (GLUT2) and pathological changes of pancreatic tissues, and the apoptosis rate of pancreatic cells in GDM mice. The relations among HOTTIP, miR-423-5p and WNT7A were validated. HOTTIP and WNT7A levels were decreased while miR-423-5p was elevated in GDM mice. The enriched HOTTIP or silenced miR-423-5p alleviated the levels of GDM‐relatedbiochemical indices, enhanced the insulin homeostasis, elevated GLUT2 expression and decreased G-6-pase and PEPCK expression, mitigated the pathological changes of pancreatic tissues, and hindered the apoptosis of pancreatic cells. MiR-143-5p upregulation abrogated the effects of elevated HOTTIP on repressing GDM; whereas WNT7A deletion reversed the therapeutic effects of reduced miR-423-5p. HOTTIP sponged miR-423-5p that targeted WNT7A. HOTTIP ameliorates insulin resistance and hepatic gluconeogenesis in GDM mice via the modulation of the miR-423-5p/WNT7A axis. This study affords novel therapeutic modalities for GDM treatment.

Extracellular Vesicles as an Index for Endothelial Injury and Cardiac Dysfunction in a Rodent Model of GDM.

Gestational diabetes mellitus (GDM) increases risk of adverse pregnancy outcomes and maternal cardiovascular complications. It is widely believed that maternal endothelial dysfunction is a critical determinant of these risks, however, connections to maternal cardiac dysfunction and mechanisms of pathogenesis are unclear. Circulating extracellular vesicles (EVs) are emerging biomarkers that may provide insights into the pathogenesis of GDM. We examined the impact of GDM on maternal cardiac and vascular health in a rat model of diet-induced obesity-associated GDM. We observed a >3-fold increase in circulating levels of endothelial EVs (p < 0.01) and von Willebrand factor (p < 0.001) in GDM rats. A significant increase in mitochondrial DNA (mtDNA) within circulating extracellular vesicles was also observed suggesting possible mitochondrial dysfunction in the vasculature. This was supported by nicotinamide adenine dinucleotide deficiency in aortas of GDM mice. GDM was also associated with cardiac remodeling (increased LV mass) and a marked impairment in maternal diastolic function (increased isovolumetric relaxation time [IVRT], p < 0.01). Finally, we observed a strong positive correlation between endothelial EV levels and IVRT (r = 0.57, p < 0.05). In summary, we observed maternal vascular and cardiac dysfunction in rodent GDM accompanied by increased circulating endothelial EVs and EV-associated mitochondrial DNA. Our study highlights a novel method for assessment of vascular injury in GDM and highlights vascular mitochondrial injury as a possible therapeutic target.

The Protective Effects of Inulin-Type Fructans Against High-Fat/Sucrose Diet-Induced Gestational Diabetes Mice in Association With Gut Microbiota Regulation.

BackgroundInulin-type fructans (ITF) have been used as prebiotics to alleviate glucose and lipid metabolism disorders. However, few studies evaluated the microbial mechanism of ITF in improving maternal metabolic status during pregnancy.MethodsC57BL/6J mice were fed a high-fat/sucrose diet (HFD) for 4 weeks before and throughout pregnancy to induce a model of gestational diabetes mellitus (GDM). Body weight, glycolipid metabolic parameters, and fecal short-chain fatty acids (SCFAs) were assessed in the experimental process. The effects of ITF on the fecal microbiota were analyzed by 16S rRNA gene amplicon sequencing.ResultsPregnant HFD-fed mice displayed significant insulin resistance and dyslipidemia. ITF (3.33 g/kg/day) treatment improved glucose and lipid metabolism disorder parameters in HFD-induced GDM mice and alleviated fat accumulation and glucose intolerance. The alpha diversity of the gut microbial community was increased in ITF mice, while the beta diversity returned to the level of normal chow diet (NCD) mice. Interestingly, Verrucomicrobia, Bifidobacterium, and Akkermansia were obviously enriched, while Dubosiella was obviously lessened after inulin treatment. Further analysis indicated that Dubosiella was positively correlated with markers of glycolipid metabolism disorders, whereas the ITF-supplemented diet partially reversed the changes.ConclusionOur results suggest that the ITF treatment may alleviate glucose and lipid metabolism disorders with the mediation of gut microbiota.

Hepatic IGF2/H19 Epigenetic Alteration Induced Glucose Intolerance in Gestational Diabetes Mellitus Offspring via FoxO1 Mediation.

ObjectiveThe offspring of women with gestational diabetes mellitus (GDM) have a high predisposition to developing type 2 diabetes during childhood and adulthood. The aim of the study was to evaluate how GDM exposure in the second half of pregnancy contributes to hepatic glucose intolerance through a mouse model.MethodsBy creating a GDM mouse model, we tested glucose and insulin tolerance of offspring by intraperitoneal glucose tolerance test (IPGTT), insulin tolerance test (ITT), and pyruvate tolerance test (PTT). In addition, we checked the expression of genes IGF2/H19, FoxO1, and DNMTs in the mouse liver by RT-qPCR. Pyrosequencing was used to detect the methylation status on IGF2/H19 differentially methylated regions (DMRs). In vitro insulin stimulation experiments were performed to evaluate the effect of different insulin concentrations on HepG2 cells. Moreover, we detect the interaction between FoxO1 and DNMT3A by chromatin immunoprecipitation–quantitative PCR (Chip-qPCR) and knock-down experiments on HepG2 cells.ResultsWe found that the first generation of GDM offspring (GDM-F1) exhibited impaired glucose tolerance (IGT) and insulin resistance, with males being disproportionately affected. In addition, the expression of imprinted genes IGF2 and H19 was downregulated in the livers of male mice via hypermethylation of IGF2-DMR0 and IGF2-DMR1. Furthermore, increased expression of transcriptional factor FoxO1 was confirmed to regulate DNMT3A expression, which contributed to abnormal methylation of IGF2/H19 DMRs. Notably, different insulin treatments on HepG2 demonstrated those genetic alterations, suggesting that they might be induced by intrauterine hyperinsulinemia.ConclusionOur results demonstrated that the intrauterine hyperinsulinemia environment has increased hepatic FoxO1 levels and subsequently increased expression of DNMT3A and epigenetic alterations on IGF2/H19 DMRs. These findings provide potential molecular mechanisms responsible for glucose intolerance and insulin resistance in the first male generation of GDM mice.

Adrenomedullin and its receptors are expressed in mouse pancreatic β-cells and suppresses insulin synthesis and secretion.

Gestational diabetes mellitus (GDM) is associated with defective pancreatic β-cell adaptation in pregnancy, but the underlying mechanism remains obscure. Our previous studies demonstrated that GDM women display increased plasma adrenomedullin (ADM) levels, and non-obese GDM mice show decreased serum concentrations of insulin and the number of β-cells in pancreas islets. The aims of this study is to examine if ADM and its receptors are expressed in female mouse pancreas, and if so, whether insulin secretion is regulated by ADM in mouse β-cell line, NIT-1 cells and isolated mouse pancreatic islets. Present study shows that ADM and its receptor components CRLR, RAMPs are present in mouse pancreatic islets and co-localized with insulin. The expressions of ADM, CRLR and RAMP2 in islets from pregnant mice are reduced compared to that of non-pregnant mice. NIT-1-β cells express ADM and its receptor mRNA, and glucose dose-dependently stimulates expressions. Furthermore, ADM inhibits NIT-1-β cell growth, and this inhibition is reversed by ADM antagonist, ADM22-52. The glucose-induced insulin secretion was suppressed by ADM in NIT-1-β cells and isolated pancreatic islets from pregnant mice. These inhibitory effects are accompanied by upregulation of endoplasmic reticulum (ER) stress biomarker genes in NIT-1-β cells. This study unveils that reduced ADM and its receptors may play a role in β-cell adaptation during pregnancy, while increased plasma ADM in GDM may contribute to the β-cells dysfunction, and blockade of ADM may reverse β-cell insulin production.

FGF4, A New Potential Regulator in Gestational Diabetes Mellitus.

Background: Gestational diabetes mellitus (GDM) is associated with adverse maternal and neonatal outcomes, however the underlying mechanisms remain elusive. The aim of this study was to find efficient regulator of FGFs in response to the pathogenesis of GDM and explore the role of the FGFs in GDM. Methods: We performed a systematic screening of placental FGFs in GDM patients and further in two different GDM mouse models to investigate their expression changes. Significant changed FGF4 was selected, engineered, purified, and used to treat GDM mice in order to examine whether it can regulate the adverse metabolic phenotypes of the diabetic mice and protect their fetus. Results: We found FGF4 expression was elevated in GDM patients and its level was positively correlated to blood glucose, indicating a physiological relevance of FGF4 with respect to the development of GDM. Recombinant FGF4 (rFGF4) treatment could effectively normalize the adverse metabolic phenotypes in high fat diet induced GDM mice but not in STZ induced GDM mice. However, rFGF4 was highly effective in reduce of neural tube defects (NTDs) of embryos in both the two GDM models. Mechanistically, rFGF4 treatment inhibits pro-inflammatory signaling cascades and neuroepithelial cell apoptosis of both GDM models, which was independent of glucose regulation. Conclusions/interpretation: Our study provides novel insight into the important roles of placental FGF4 and suggests that it may serve as a promising diagnostic factor and therapeutic target for GDM.