Gestational Diabetes Mellitus Rats Research Articles

The effects of Oldenlandia diffusa water extract on glucose metabolism and inflammation level in rats with streptozotocin-induced gestational diabetes mellitus

To reveal the effects of Oldenlandia diffusa (OD) on relieving the progression and development of gestational diabetes mellitus (GDM), and explore the underlying mechanism. A rat model of GDM was established by streptozotocin injection. The effects of OD on GDM rats were evaluated by measuring the levels of fasting blood glucose (FBG), insulin, and hemoglobin A1c (HbA1c), and exposing to oral glucose tolerance test (OGTT) and histological evaluation of the pancreas. The levels of insulin and inflammation response-related factors (tumor necrosis factor [TNF]-α, Interleukin [IL]-6 and IL-1β) were evaluated by enzyme-linked immunosorbent assay (ELISA). Additionally, immunoblot assay was performed to investigate the effects of OD on the nuclear factor-κb (NF-κB) pathway and 5' adenosine monophosphate-activated protein kinase (AMPK) pathway. OD decreased blood glucose level, pancreatic tissue damage, and insulin secretion in GDM rats. OD also reduced serum inflammatory levels (TNF-α, IL-6, and IL-1β) in GDM rats. Mechanically, OD could inhibit NF-κB pathway and activate AMPK pathway in the pancreatic tissue of GDM rats. OD affected glucose metabolism and inflammation level in rats with streptozotocin-induced GDM, and the underlying mechanism was through AMPK pathway. OD might serve as a promising and potential drug for the treatment of GDM.

RETRACTED ARTICLE: Impacts of lipopolysaccharide on fetal lung developmental maturity and surfactant protein B and surfactant protein C protein expression in gestational diabetes mellitus rats

Statement of Retraction Yue Gao, Ziwei Zhang, Yan Wang, Dayong Zhou, Jinghua Zhou, Jinghua Zhang, Xiaoyu Chen, Xin Li, and Qingliang Shao- 2022, Impacts of Lipopolysaccharide on Fetal Lung Developmental Maturity and Surfactant Protein B and Surfactant Protein C Protein Expression in Gestational Diabetes Mellitus Rats, Bioengineered 13(1), doi: 10.1080/21655979.2021.2013099 Since publication, significant concerns have been raised about the integrity of the data and reported results in the article. When approached for an explanation, the authors did not provide their original data or any necessary supporting information. As verifying the validity of published work is core to the integrity of the scholarly record, we are therefore retracting the article. All authors listed in this publication have been informed. We have been informed in our decision-making by our editorial policies and the COPE guidelines. The retracted article will remain online to maintain the scholarly record, but it will be digitally watermarked on each page as ‘Retracted’.

The enamel thickness of gestational diabetes mellitus rat offspring

Objective: To determine the molar enamel thickness of rat offsprings born to diabetic rat.Material and Methods: This research used sixteen rat offsprings born to 8 diabetic rats who had been injected with STZ dose of 40 mg / kg and 16 rat offsprings born to 8 control rats. Rat offsprings were decapitated on day 5 after birth and taken right mandibular molar tooth germ. Tooth germ then embedded in paraffin block. Haematoxylin eosin staining performed for histological analysis. Enamel thickness measured on the images using ImageJ Software at 5 field of view.Results: The enamel thickness on the Diabetes Mellitus (DM) group (333.02 ± 135.81 µm) were lower than control group (415.39 ± 146.17 µm). Mann Whitney test results showed a significant difference between the DM and control group.Conclusion: It was concluded that enamel thickness decreases in gestational diabetes mellitus rat offspring.

The Effect of Resveratrol on Blood Glucose and Blood Lipids in Rats with Gestational Diabetes Mellitus.

Background Previous studies have reported that resveratrol has various biological effects such as anti-inflammatory, antioxidant, and antitumor. This study aimed to investigate the effects of resveratrol on blood glucose and blood lipids in rats with gestational diabetes mellitus (GDM). Methods The rat diabetes model was prepared by one-time intraperitoneal injection of streptozotocin (STZ, 35 mg/kg). Fasting blood glucose was measured by using a blood glucose meter. The ELISA method was used to detect the levels of insulin, leptin, adiponectin, resistin, TNF-α, and IL-6. The content of TC, TG, LDL-C, and HDL-C was determined by using an automatic biochemical detector. Results Compared with the GDM group, the insulin level in the resveratrol (120 and 240 mg/kg) treatment group was significantly increased. But, the blood glucose level and body weight were significantly reduced. The content of TC, TG, and LDL-C in the resveratrol (240 mg/kg) treatment group was significantly reduced, and the content of HDL-C was significantly increased. In addition, leptin, resistin, TNF-α, and IL-6 levels in the 240 mg/kg resveratrol treatment group were significantly reduced, and adiponectin was significantly increased. Also, resveratrol (240 mg/kg) was stronger than metformin hydrochloride in improving insulin secretion and regulating blood lipids and adipokine content. Conclusion Resveratrol has a dose-dependent effect on GDM rats to increase insulin secretion, reduce blood glucose and body weight, and regulate blood lipids and plasma adipokines.

Serum and Amniotic Fluid Metabolic Profile Changes in Response to Gestational Diabetes Mellitus and the Association with Maternal-Fetal Outcomes.

This study was designed to identify serum and amniotic fluid (AF) metabolic profile changes in response to gestational diabetes mellitus (GDM) and explore the association with maternal–fetal outcomes. We established the GDM rat models by combining a high-fat diet (HFD) with an injection of low-dose streptozotocin (STZ), detected the fasting plasma glucose (FPG) of pregnant rats in the second and third trimester, and collected AF and fetal rats by cesarean section on gestational day 19 (GD19), as well as measuring the weight and crown–rump length (CRL) of fetal rats. We applied liquid chromatography–tandem mass spectrometry (LC-MS/MS) for the untargeted metabolomics analyses of serum and AF samples and then explored their correlation with maternal–fetal outcomes via the co-occurrence network. The results showed that 91 and 68 metabolites were upregulated and 125 and 78 metabolites were downregulated in serum and AF samples exposed to GDM, respectively. In maternal serum, the obvious alterations emerged in lipids and lipid-like molecules, while there were great changes in carbohydrate and carbohydrate conjugates, followed by amino acids, peptides, and analogs in amniotic fluid. The altered pathways both in serum and AF samples were amino acid, lipid, nucleotide, and vitamin metabolism pathways. In response to GDM, changes in the steroid hormone metabolic pathway occurred in serum, and an altered carbohydrate metabolism pathway was found in AF samples. Among differential metabolites in two kinds of samples, there were 34 common biochemicals shared by serum and AF samples, and a mutual significant association existed. These shared differential metabolites were implicated in several metabolism pathways, including choline, tryptophan, histidine, and nicotinate and nicotinamide metabolism, and among them, N1-methyl-4-pyridone-3-carboxamide, 5’-methylthioadenosine, and kynurenic acid were significantly associated with both maternal FPG and fetal growth. In conclusion, serum and AF metabolic profiles were remarkably altered in response to GDM. N1-Methyl-4-pyridone-3-carboxamide, 5’-methylthioadenosine, and kynurenic acid have the potential to be taken as biomarkers for maternal–fetal health status of GDM. The common and inter-related differential metabolites both in the serum and AF implied the feasibility of predicting fetal health outcomes via detecting the metabolites in maternal serum exposed to GDM.

Comparison on the curative effect of human placenta-derived mesenchymal stem cells and induced islet-like cells in gestational diabetes mellitus rats

Comparison on the curative effect of human placenta-derived mesenchymal stem cells and induced islet-like cells in gestational diabetes mellitus rats

Myrtenol alleviates oxidative stress and inflammation in diabetic pregnant rats via TLR4/MyD88/NF-κB signaling pathway.

Gestational diabetes mellitus (GDM) is a special kind of diabetes that arises only during pregnancy. A woman with GDM has a higher risk of developing type-2 diabetes and other metabolic diseases. In this exploration, we intended to scrutinize the therapeutic actions of Myrtenol against the streptozotocin (STZ)-provoked GDM in rats. GDM was provoked in the pregnant rats via injecting the 1% of STZ (25 mg/kg) and then treated with the 50 mg/kg of myrtenol. The glucose level and bodyweight of animals were noted. The lipid profile, that is, total cholesterol, triglycerides, low-density lipoprotein, and high-density lipoprotein (HDL) was determined by respective kits. The lipid peroxidation and antioxidants status were examined using assay kits. The status of proinflammatory markers was investigated by assay kits. The messenger RNA (mRNA) expressions of TLR4/MyD88/NF-κB signaling proteins were studied by reverse transcription polymerase chain reaction analysis. The hepatic and pancreatic tissues were examined microscopically. Myrtenol treatment notably decreased the status of blood glucose and lipid profile and improved the HDL in the GDM rats. The status of lipid peroxidation and inflammatory markers were substantially reduced by the myrtenol and it enhanced the antioxidants status of GDM animals. Myrtenol treatment remarkably downregulated the mRNA expressions of TLR4/MyD88/NF-κB signaling proteins. The histological findings also proved the therapeutic actions of myrtenol. Altogether, the findings of this investigation unveiled the therapeutic actions of the myrtenol against the STZ-provoked GDM in rats. Myrtenol could be a promising therapeutic agent to treat GDM in the future.

Abstract 61: Cd4+t Cells Cause Hypertension, Increased Glucose, And Mitochondrial Dysfunction In A Novel Rodent Model Of Gestational Diabetes Mellitus

Hypertensive (HTN) disorders of pregnancy increase risks for gestational diabetes mellitus (GDM) in pregnant women. GDM is characterized by hyperglycemia and β-cell dysfunction associated with increased inflammatory cytokines, oxidative stress, and activated CD4+ T cells. Streptozotocin (STZ) is used in nonpregnant rats to induce β-cell destruction causing features of diabetes. However, STZ is not ideal for pregnancy and leads to unsuccessful pregnancy outcomes, therefore other ways to establish animal models of GDM must be pursued. Previously, we showed CD4+T cells from a rat model of preeclampsia causes HTN and mitochondrial (mt) dysfunction/ROS compared to normal pregnant (NP) rats. Therefore, we hypothesize CD4+ T cells from a diabetic rat model could cause mt dysfunction/ROS and pancreatic β-islet cell destruction and lead to increased glucose and HTN during pregnancy. To examine our hypothesis, we adoptively transferred CD4+ T cells from STZ Dahl diabetic rats into pregnant Sprague Dawley (SD) rats and measured GDM features. Circulating CD4+ T cells were isolated from STZ induced diabetic Dahl virgin female rats and injected into pregnant SD rats on gestational day (GD) 12. On GD19, blood pressure (MAP) and tissues were collected and glucose levels were measured after 2h fasting in STZ CD4+ T cell recipients (GDM) and NP controls. Mt respiration and mtROS was measured in isolated mitochondria. On GD19, MAP increased to 105±0.5 mmHg (n=4, p<0.05) in GMD pregnant rats compared to control NP rats 91±2.1 mmHg (n=3). Blood glucose levels were elevated in GDM rats (139 ± 7 mg/dl, n=4, p<0.05) compared to NP controls (94 ± 1 mg/dl, n=3). Placental state 3 (26.4±5.9 vs 53.9±1.7 pmol/sec/mg, p<0.05) respiration rates, indicative of ATP production, was reduced in GDM rats (n=4) compared to NP controls (n=3). Placental mtROS was significantly increased in GDM rats (190 ± 27.1 % gated, n=3, p<0.05) compared to NP rats (100 ± 2.7 % gated, n=3). Collectively, the data indicate adoptive transfer of STZ CD4+ T cells causes increased circulating glucose, placental mt dysfunction and mtROS and HTN during pregnancy. These data demonstrate the importance of CD4+T cells in mechanisms causing the pathophysiology of GDM, and also introduces a potential novel animal model of GDM.

Crocetin suppresses gestational diabetes in streptozotocin-induced diabetes mellitus rats via suppression of inflammatory reaction.

Gestational diabetes mellitus (GDM) is the serious complication of pregnancy induced via dysfunction in glucose metabolism during the pregnancy. Crocetin already proved antidiabetic effect in streptozotocin (STZ)-induced diabetes mellitus in rats. In this protocol, we have investigated the potential effect of crocetin against STZ-induced GDM in rats. Wistar rats were used for the current protocol; STZ was used for the induction for DM and finally caused the GDM. Body weight and serum advanced glycation end products level were estimated at regular time intervals. We also estimated the fetus weight and placental weight. Biochemical, antioxidant, pro-inflammatory cytokines, inflammatory mediators, and apoptosis parameters were estimated. mRNA expression of NOX2, RAGE, MCP-1, VCAM-1, EGFR, and p65 were also estimated. Crocetin treatment significantly (p<.001) reduced the fetus weight and increased the placental weight and index. Crocetin significantly (p<.001) reduced the blood glucose level and increased the body weight. Crocetin significantly (p<.001) boosted the level of antioxidant enzymes and includes superoxide dismutase, glutathione peroxidase, glutathione, and catalase. Crocetin significantly (p<.001) altered the level of lipid parameters and pro-inflammatory cytokines. Crocetin significantly (p<.001) reduced the level of intercellular adhesion molecule 1, cyclooxygenase-2, and nuclear factor kappa B and increased the level of visfatin against GDM rats. Crocetin significantly (p<.001) altered the level of mRNA expression. Based on the result, we can say that crocetin is a protective drug against the GDM in pregnant rats via antioxidant, inflammatory, and apoptosis parameters. PRACTICAL APPLICATIONS: As we all know, gestational diabetes mellitus (GDM) cases rise all over the world. The current investigation showed the protective effect of crocetin on GDM in experimental rats. The current finding exhibited the protective effect of crocetin against STZ-induced GDM via suppression of inflammatory, oxidative, and apoptosis parameters. The result suggests the antioxidant and anti-inflammatory effect of crocetin. Crocetin can be used as a preventive medication in the treatment of gestational diabetes mellitus, according to the latest findings.

Zinc, selenium and chromium co-supplementation improves insulin resistance by preventing hepatic endoplasmic reticulum stress in diet-induced gestational diabetes rats

Gestational diabetes mellitus (GDM) is one of the most common pregnancy complications and results in adverse outcomes for pregnant women and their offspring. Endoplasmic reticulum (ER) stress is associated with insulin resistance and implicates in the development of GDM. Zinc, selenium and chromium have been shown to maintain glucose homeostasis via multiple mechanisms, but how these trace elements affect the insulin resistance and ER stress in GDM are largely unknown. To address this, a GDM rat model was induced by feeding female Sprague-Dawley rats a high-fat (45%) and sucrose diet, while zinc (10 mg/kg.bw), selenium (20 ug/kg.bw), chromium (20 ug/kg.bw) were daily supplemented alone or in combination from 6 weeks before mating to the end of lactation period. Maternal metabolic parameters, hepatic ER stress and insulin signaling were analyzed. The results showed that zinc, selenium and chromium co-supplementation dramatically alleviated high-fat and sucrose-induced glucose intolerance and oxidative stress during entire experiment period. Hepatic ER stress as well as the unfolded protein response was activated in GDM dams, characterized by the up-regulation of glucose-regulated protein 78, phosphorylated the protein kinase RNA-like endoplasmic reticulum kinase, and the inositol-requiring enzyme 1α. Zinc, selenium and chromium supplementation significantly prevented this activation, by which contributes to the promotion of the phosphorylated protein kinase B related insulin signaling and maintenance of glucose homeostasis. In conclusion, zinc, selenium and chromium supplementation may be a promising way to prevent the development of GDM by alleviating hepatic ER stress.

Intergenerational effects of the antioxidant Idebenone on the placentas of rats with gestational diabetes mellitus

Experimental models of maternal diabetes lead to the intrauterine programming of Gestational Diabetes Mellitus (GDM) in the offspring, together with an intrauterine proinflammatory environment, feto-placental metabolic alterations and fetal overgrowth. The aim of this work was to evaluate the effect of the mitochondrial antioxidant Idebenone given to F0 mild pregestational diabetic rats on the development of GDM in their F1 offspring and the intergenerational programming of a pro-oxidant/proinflammatory environment that affects the placentas of F2 fetuses. Control and mild pregestational diabetic female rats (F0) were mated with control males, and Idebenone or vehicle was administered to diabetic rats from day 1 of gestation to term. The F1 female offspring were mated with control males and maternal and fetal plasma samples were obtained for metabolic determinations at term. The F2 fetuses and placentas were weighed, and placental protein levels and peroxynitrite-induced damage (immunohistochemistry), mRNA levels (PCR), nitric oxide production (Griess reaction), and number of apoptotic cells (TUNEL) were evaluated. The F1 offspring of F0 diabetic rats (treated or not with Idebenone) developed GDM. The placentas of GDM rats showed a decrease in the mRNA levels of manganese superoxide dismutase and an increase in the production of nitric oxide, peroxynitrite-induced damage, and connective tissue growth factor levels, alterations that were prevented by the maternal Idebenone treatment in F0 rats. In conclusion, the maternal treatment with Idebenone in pregestational diabetic F0 rats ameliorates the pro-oxidant/proinflammatory environment that affects the placentas of F2 fetuses, although it does not prevent F1 rats from developing GDM.

Adiponectin agonist treatment in diabetic pregnant rats.

Gestational diabetes mellitus (GDM) reduces maternal adiponectin and docosahexaenoic acid (DHA) materno-fetal transfer, which may have negative consequences for the offspring. Our aim was to evaluate the effects of the administration of a novel adiponectin agonist (AdipoRon) to GDM rats on the long-term consequences in glycaemia and fatty acids (FA) profile in the offspring. Pregnant rats were randomized to three groups: GDM rats (GDM, n = 8), GDM rats treated with AdipoRon (GDM + ADI, n = 9), and control rats (n = 10). Diabetes was induced with streptozotocin (50 mg/kg) on day 12 of gestation. GDM+ADI received 50 mg/kg/day AdipoRon from day 14 until delivery. Glycaemia and FA profile were determined in mothers and adult offspring (12 weeks old). AdipoRon tended to reduce fasting glucose in diabetic mothers. Diabetic rats presented the foetus with intrauterine growth restriction and higher adiposity, which tried to be counteracted by AdipoRon. In the adult offspring, both GDM + ADI and control animals showed better glucose recovery after oral glucose overload with respect to GDM. DHA in offspring plasma was significantly reduced in both GDM and GDM + ADI compared to controls (P = 0.043). Nevertheless, n-6/n-3 polyunsaturated FA (PUFA) ratio improved in plasma of GDM + ADI adult offspring (GDM: 14.83 ± 0.85a%; GDM + ADI: 11.49 ± 0.58b%; control: 10.03 ± 1.22b%, P = 0.034). Inflammatory markers and oxidative stress were reduced in the adult offspring of AdipoRon-treated mothers. In conclusion, AdipoRon administration to pregnant diabetic rats improved glycaemia in the mothers and long-term glucose tolerance in the offspring. In addition, it tended to reduce excessive foetal fat accumulation and improved n-6/n-3 PUFA ratio significantly in offspring at the adult state.

MiR‑875‑5p regulates IR and inflammation viatargeting TXNRD1 in gestational diabetes rats.

Gestational diabetes mellitus (GDM) is a serious life-threatening disease that affects the mother and fetus. However, the pathogenesis of GDM is still unclear. microRNAs (miRs) play vital roles in the regulation of various cell functions. The present study aimed to investigate the effects of miR-875-5p and thioredoxin reductase 1 cytoplasmic (TXNRD1) in GDM rats and analyze the associated underlying mechanism. A GDM rat model was induced using an intraperitoneal injection of streptozotocin. miR-875-5p knockdown plasmids or TXNRD1 knockdown plasmids were injected into the rats via the caudal vein. miR-875-5p and TXNRD1 expression in the serum were detected using reverse transcription-quantitative PCR (RT-qPCR) or western blot (WB) analyses. The fasting blood-glucose (FBG), fasting serum insulin, triglyceride and high density lipoprotein levels were detected by specific commercial kits. The inflammatory response and the induction of oxidative stress were analyzed by assessing the expression of associated markers via WB, RT-qPCR or commercial kits. The pancreatic and placental injuries were detected by hematoxylin and eosin staining. The results indicated that miR-875-5p expression levels were downregulated, whereas TXNRD1 levels were upregulated in GDM rats compared with normal pregnancy rats. miR-875-5p significantly regulated TXNRD1 expression in GDM rats. miR-875-5p silencing notably reduced FBG and insulin resistance, which was accompanied by reduced expression levels of blood lipid and pro-inflammatory markers as well as reduced oxidative stress. However, the effects of miR-875-5p could be reversed by TXNRD1 silencing. Therefore, the present study indicated that miR-875-5p regulated IR and inflammation by targeting TXNRD1 in GDM rats. miR-875-5p and TXNRD1 may be considered as potential targets for treating GDM.

Paeoniflorin attenuates gestational diabetes via Akt/mTOR pathway in a rat model.

BackgroundGestational diabetes mellitus (GDM) is a type of diabetes associated with pregnancy and may impose risks on both mother and fetus. Akt paeoniflorin was shown to have anti-inflammatory and anti-hyperglycemia properties and has a potential ability to suppress mammalian target of rapamycin (mTOR) signaling. The current study aimed to study the effect of paeoniflorin on GDM maternal, fetal, and placental characteristics in vivo.MethodsStreptozotocin (STZ)-induced gestational diabetes rat model was used in our study. The expression levels of phosphorylation (p-) and total protein expression levels of protein kinase B (Akt), mTOR, serum/glucocorticoid regulated kinase 1 (SGK1), and eIF4E-binding protein 1 (4E-BP1) in the placenta were determined by Western blot assay. The blood glucose, insulin, and leptin levels were assessed using enzyme-linked immunosorbent assay (ELISA).ResultsWe found that placental Akt/mTOR signaling was substantially upregulated in GDM patients compared with healthy donors. Paeoniflorin administration alleviates the dysregulation of blood glucose, leptin, and insulin levels in both maternal and fetal GDM rats. Paeoniflorin treatment suppressed the overactivation of Akt/mTOR signaling in placental tissues. More importantly, administration of paeoniflorin was beneficial for normalization of fetal size and body weight in the GDM rats.ConclusionOur study suggested that application of paeoniflorin may serve as a potential therapeutical strategy for patients with GDM.

Anti-inflammatory activities of puerarin in high-fat diet-fed rats with streptozotocin-induced gestational diabetes mellitus

To investigate the effect of puerarin on insulin resistance and inflammation in rats with gestational diabetes mellitus (GDM). Gestational diabetic model rats were established by intraperitoneal injection of streptozotocin (25 mg/kg) combined with high-fat feeding and were randomly assigned to three groups: the control group, the GDM group, and the puerarin-treated group. Puerarin was intragastrically administered to rats daily until the offspring were born. The rats in both the GDM group and control group were administered the same volume of normal saline. Serum total cholesterol, triglycerides, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol in all groups of rats were measured. Haematoxylin and eosin staining was used to evaluate morphological changes in the liver, pancreas, and adipose tissues around the reproductive organs. Western blotting was carried out to measure the protein expression of IRS-1 and inflammatory factors, including TNF-α, TLR4, MyD88 and phosphorylated NF-κB, in the adipose tissues around the reproductive organs. Puerarin had preventive effects on GDM-induced pathological changes and ameliorated glucose and lipid metabolism disorders in GDM rats. Puerarin upregulated IRS-1 expression and decreased the protein expression of TNF-α, TLR4, and MyD88 as well as the levels of phosphorylated NF-κB in adipose tissues around the reproductive organs in GDM rats. This study indicated that puerarin exerts anti-inflammatory effects by downregulating the important TLR4/MyD88/NF-κB inflammatory signalling pathway. Therefore, puerarin can decrease the expression of TNF-α and ameliorate insulin resistance in GDM rats, suggesting the potential efficacy of puerarin in GDM treatment.

&lt;p&gt;The Role of PPARδ Agosnist GW501516 in Rats with Gestational Diabetes Mellitus&lt;/p&gt;

BackgroundGestational diabetes mellitus (GDM) is a disorder of glucose metabolism that occurs or is found for the first time during pregnancy. GDM is very harmful and urgently needs drug treatment to improve pregnancy outcome. PPARδ is involved in a variety of biological processes related to glycolipid metabolism in the body, suggesting that it may be closely related to insulin resistance and impaired glucose tolerance. The role of PPARδ agonist GW501516 in gestational diabetes has not been studied.MethodsFirstly, the rat model of GDM was established. Then, fasting blood-glucose (FGB), fasting insulin (FINS), HOMA-islet resistance index (HOMA-IR) and insulin sensitivity index (ISI) of GDM rats treated with GW501516 were measured on day 3, day 10 and day 17. Glucose tolerance test was performed on the 20th day of gestation to measure glucose tolerance in rats. The expression of PPARδ and Angptl8 in islet tissues of rats was detected by Western blot and immunohistochemistry (IHC). Histopathological changes of islet were detected by HE stain; apoptosis rate of islet cells was detected by Tunel; and expression of apoptosis-related proteins in the cells was detected by Western blot. The biochemical kits were used to detect the expression of lipid metabolism-related factors in blood of GDM rats after the PPARδ agonist GW501516 treatment. Finally, the expression of SREBP-1c and GLUT2 in islet tissues was detected by RT-qPCR and IHC.ResultsThe PPARδ agonist GW501516 decreased the expression of FGB, FINS and HOMA-IR in GDM rats, and we found that GW501516 decreased ISI in GDM rats. GW501516 increased glucose tolerance in GDM rats too. In GDM rats, the expression of PPARδ in islet decreased and the expression of Angptl8 increased, which was reversed by GW501516. In addition, we also found that GW501516 can improve the damaged islet tissue of GDM rats, reduce the apoptosis rate of islet cells and inhibit the expression of lipid metabolism-related factors in the blood. Finally, we found that GW501516 inhibited the expression of SREBP-1c and promoted the expression of GLUT2 in the islet tissue.ConclusionThe PPARδ agonist GW501516 could improve the blood glucose level, damaged islet tissue and increase the insulin content in the rats with GDM, possibly by regulating the SREBP-1c/GLUT2 pathway. Our study provided a new basis for clinical treatment of GDM in pregnant women with PPARδ agonist GW501516.

Protective effect of Specnuezhenide on islet β cell of rats with gestational diabetes mellitus

Gestational diabetes mellitus (GDM) refers to diabetes mellitus and impaired glucose tolerance first diagnosed during pregnancy without previous history of the disease. Usually, GDM has a high risk of inducing type 2 diabetes mellitus. The incidence of GDM is increasing year by year worldwide, and it seriously affects the quality of life of patients, and increases the risk to pregnancy. Specnuezhenide (SPZ) is a characteristic active component of Ligustrum lucidum, a plant which exerts a variety of pharmacological effects. In this study, the protective effect of SPZ on β cells in gestational diabetes mellitus rats was investigated in a rat model of gestational diabetes. Based on oral glucose tolerance test, ELISA, qRT-PCR and western blotting assays, It was found that SPZ effectively improved blood sugar control and glucose tolerance in gestational diabetic rats, inhibited inflammation in islet tissue, and reduced inflammation-mediated insulin resistance.

Proinflammation in maternal and fetal livers and circulating miR-122 dysregulation in a GDM rat model induced by intrauterine programming

In gestational diabetes mellitus (GDM) pregnancies, a compromised fetal liver may impact offspring's metabolic health. Here, we aimed to address prooxidant, proinflammatory and profibrotic markers in the livers from GDM rats and their fetuses, and to analyze the expression of miR-122 (a relevant microRNA in liver pathophysiology) in fetal and maternal plasma of GDM rats, as well as in the fetal livers of neonatal streptozotocin-induced (nSTZ) diabetic rats, the rats that generate GDM through intrauterine programming. GDM and nSTZ rats were evaluated on day 21 of pregnancy. We found increased nitric oxide production and lipoperoxidation in the livers from GDM rats and their fetuses compared to controls. Livers from GDM fetuses also showed increased levels of connective tissue growth factor and matrix metalloproteinase-2. The expression of miRNA-122 was downregulated in the plasma from GDM rats and their male fetuses, as well as in the livers from male fetuses of nSTZ diabetic rats. miR-122 levels were regulated both in vitro through PPARγ activation and in vivo through a maternal diet enriched in PPAR ligands. Our findings revealed a prooxidant/proinflammatory environment in the livers from GDM rats and their fetuses and a dysregulation of miR-122, likely relevant in the programming of offspring's diseases.

Stress adaptation disorders play a role in rat gestational diabetes with oxidative stress and glucose transporter-4 expression

Stress adaptation disorder exists in gestational diabetes mellitus (GDM) women, this study was to investigate the impact of stress adaptation disorder on glucose disposal and skeletal muscle glucose transporter4 (GLUT4) expression in GDM rat model. Rats were assigned randomly to Normal control (NC) group and GDM group. We analyzed the levels of corticosterone, epinephrine (E), norepinephrine (NE), malondialdehyde (MDA) and superoxide dismutase (SOD), interleukin-6 (IL-6) and expression of GLUT4 were also detected. Homeostasis model assessment (HOMA-IR) was used to evaluate insulin resistance. Compared with NC group, E, NE and Corticosterone were increased significantly, SOD and MDA were higher and GLUT4 expression was significantly lower in GDM rats. Corticosterone was positively related to MDA, MDA was positively and SOD was negatively related to HOMA-IR in both groups, IL-6 showed significant positive correlations with HOMA-IR. NE and Corticosterone were negative related to GLUT4 in GDM group. Stress hormones (E, NE and Corticosterone), MDA and IL-6 were the risk factors of GDM, SOD was the protective factor of GDM. Changes of stress hormones indicate that stress adaptation disorder exists in GDM rats. Stress adaptation disorder increase oxidative stress injury and inflammation, decrease GLUT4 and lead to incline of glucose uptake, result in hyperglycemia. Gaining an insight into correlations of these changes may be beneficial to maternal and child health and is important for the prevention of glycemia-related diseases.

Downregulation of microRNA-873 attenuates insulin resistance and myocardial injury in rats with gestational diabetes mellitus by upregulating IGFBP2

Gestational diabetes mellitus (GDM) is a metabolic disorder characterized by insulin resistance, and patients with GDM have a higher risk of cardiovascular disease. Multiple microRNAs (miRNAs) are reported to be involved in the regulation of myocardial injury. Moreover, miR-873 was predicted to target insulin-like growth factor binding protein 2 (IGFBP2) through bioinformatic analysis, which was further confirmed using a luciferase assay. Thus, our objective was to assess whether microRNA-873 (miR-873) affects insulin resistance and myocardial injury in an established GDM rat model. The GDM rats were treated with miR-875 mimic or inhibitor or IGFBP2 siRNA. The effects of miR-875 and IGFBP2 on the cardiac function, insulin resistance, and myocardial injury were evaluated by hemodynamic measurements, determination of biochemical indices of myocardium and serum, and insulin homeostatic model assessment. The results indicated that downregulation of miR-873 upregulated the expression of IGFBP2 and promoted the activation of phosphatidylinositol-3 kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) axis. With downregulation of miR-873 in GDM rats, the cardiac function was improved and the myocardial apoptosis was inhibited, coupled with elevated activity of superoxide dismutase, carbon monoxide synthase, and the nitric oxide content. In addition, the inhibition of miR-873 in GDM rats modulated the insulin resistance and reduced myocardial apoptosis. Overall, the data showed that inhibition of miR-873 by targeting IGFBP2 may regulate the insulin resistance and curtail myocardial injury in GDM rats through activating the PI3K/AKT/mTOR axis, thus providing a potential means of impeding the progression of GDM.