The postpartum effect of maternal diabetes on the circulating levels of sirtuins and superoxide dismutase

Impact of vitamin D resistance genes on vitamin D deficiency during pregnancy among the South Indian population

Increasing evidence suggests that vitamin D (Vit-D) could be pivotal in maintaining normal glucose homeostasis. Low levels of Vit-D in early pregnancy are associated with a higher risk of gestational diabetes mellitus (GDM). Though several reports have highlighted the prevalence of vit-D deficiency among pregnant women, its underlying cause has not yet been fully elucidated. In this connection, a few studies have found the development of resistance to Vit-D, including the levels of Vitamin D receptor (VDR) and transcription regulators that modify VDR action, as well as the bioavailability of Vit-D. We aimed to determine the levels of Vit-D resistance genes such as 25-HydroxyVit-D-24-hydroxylase (CYP24A1), VDR repressor genes (SNAIL and SMRT) and their association between Vit-D concentrations in early pregnancy, and the risk of gestational diabetes mellitus (GDM). A prospective observational study was conducted on healthy pregnant women (NGDM; n = 50) and GDM (n = 50) attending routine antenatal care at SRM Medical College Hospital, Chennai, recruited at 12 weeks of gestation. We found that the serum levels of Vit-D were low in GDM subjects and negatively correlated with the fasting glucose levels. Further, increased expressions of Vit-D resistance genes such as CYP24A1, SNAIL, and SMRT were observed in GDM subjects and negatively correlated with the serum levels of Vit-D. Furthermore, we have validated the data using the trophoblast cell line, BeWo, exposed to calcitriol under a hyperglycemic environment. Our finding showed that increased expression of Vit-D resistance genes in pregnancy may be associated with a greater risk of adverse pregnancy outcomes, including GDM.

Phytochemical Screening on Phenolic, Flavonoid Contents, and Antioxidant Activities of Six Indigenous Plants Used in Traditional Thai Medicine

The antioxidant activity of a traditional Thai formula has been studied and compared to each plant. The formula comprised the roots of Caesalpinia digyna Rottler, Huberantha cerasoides (Roxb.) Benth), Oxyceros horridus Lour, Antidesma ghaesembilla Gaerth, Combretum quadrangulare Kurz, and Ziziphus cambodiana Pierre. The stem was also studied in comparison. The ethanolic extract from each plant part and the mixed plants mimicking the traditional formula were prepared and investigated for antioxidant capability in vitro via DPPH radical scavenging and ferric-reducing antioxidant power assays. The phytochemical constituents were determined by chemical screening, total phenolic (TPC) and flavonoid contents (TFC), and high-performance liquid chromatography. The relationship between antioxidant activity and the contributed phytochemicals was determined using correlation analysis and principal component analysis (PCA). Results showed that extracts from both parts of the plant formula showed the highest antioxidant activity compared to a single plant extract. Among the six plants, C. digyna exhibited the highest TPC and antioxidant activity. TPC had a strong positive correlation with antioxidant activity. PCA revealed that gallic acid contributed to the antioxidant activity. In conclusion, the ethanolic extracts of the traditional formula and C. digyna have the potential for further chemical characterization and study related to antioxidant activity.

Advances in the role of silence information regulator family in pathological pregnancy

Aberrant maternal inflammation and oxidative stress are the two main mechanisms of pathological pregnancy. The silence information regulator (sirtuin) family is a highly conserved family of nicotinamide adenine dinucleotide (NAD)-dependent deacylases. By regulating the post-translational modification of proteins, sirtuin is involved in various biological processes including oxidative stress and inflammation. Nowadays, emerging evidence indicates that sirtuin may be closely related to the occurrence and development of pathological pregnancy. The down-regulation of sirtuin can cause spontaneous preterm delivery by promoting uterine contraction and rupture of fetal membranes, cause gestational diabetes mellitus through promoting oxidative stress and affecting the activity of key enzymes in glucose metabolism, cause preeclampsia by reducing the proliferation and invasion ability of trophoblasts, cause intrahepatic cholestasis of pregnancy by promoting the production of bile acids and T helper 1 cell (Th1) cytokines, and cause intrauterine growth restriction through inducing mitochondrial dysfunction. Moreover, the expression and activation of sirtuin can be modulated through dietary interventions, thus sirtuin is expected to become a new target for the prevention and treatment of pregnancy complications. This article reviews the role of the sirtuin family in the occurrence and development of pathological pregnancy and its influence on the development of the offspring.

MiRNAs in Gestational Diabetes Mellitus: Potential Mechanisms and Clinical Applications

Gestational diabetes mellitus (GDM) is a common pregnancy complication which is normally diagnosed in the second trimester of gestation. With an increasing incidence, GDM poses a significant threat to maternal and offspring health. Therefore, we need a deeper understanding of GDM pathophysiology and novel investigation on the diagnosis and treatment for GDM. MicroRNAs (miRNAs), a class of endogenic small noncoding RNAs with a length of approximately 19-24 nucleotides, have been reported to exert their function in gene expression by binding to proteins or being enclosed in membranous vesicles, such as exosomes. Studies have investigated the roles of miRNAs in the pathophysiological mechanism of GDM and their potential as noninvasive biological candidates for the management of GDM, including diagnosis and treatment. This review is aimed at summarizing the pathophysiological significance of miRNAs in GDM development and their potential function in GDM clinical diagnosis and therapeutic approach. In this review, we summarized an integrated expressional profile and the pathophysiological significance of placental exosomes and associated miRNAs, as well as other plasma miRNAs such as exo-AT. Furthermore, we also discussed the practical application of exosomes in GDM postpartum outcomes and the potential function of several miRNAs as therapeutic target in the GDM pathological pathway, thus providing a novel clinical insight of these biological signatures into GDM therapeutic approach.

Advanced glycation end products and adipocytokines and oxidative stress in placental tissues of pregnant women with gestational diabetes mellitus

Correlation between expression levels of advanced glycation end products (AGEs) and adipocytokines and oxidative stress index malondialdehyde (MDA) in placental tissues of pregnant women with gestational diabetes mellitus (GDM) was investigated. Seventy-two cases of GDM pregnant women who received routine prenatal examination and gave birth in the Department of Obstetrics, Binzhou City Center Hospital from March 2016 to May 2017 were collected as the observation group. Another 80 cases of normal pregnant women who gave birth at the same time were selected as the control group. Enzyme linked immunosorbent assay (ELISA) was used to detect the expression levels of AGEs, visfatin, APN and IL-6 in the lysate of placental tissues. MDA levels were measured by thiobarbituric acid method. Correlation of expression levels of AGEs, visfatin, APN, IL-6 and MDA were analyzed. The expression level of MDA in placental tissues of the observation group was significantly higher than that of the control group (t=16.44, P<0.001). The correlation of expression levels between AGEs, adipocytokines and MDA in placental tissues of the two groups was analyzed, and it was found that the expression levels of AGEs, visfatin and IL-6 in the two groups were positively correlated with MDA. There was a significantly negative correlation between APN and MDA in the two groups. The incidence of cesarean section, neonatal hypoglycemia, fetal distress and macrosomia in the observation group was significantly higher than that in the control group (P<0.05). There was no significant difference in the incidence of membrane rupture and premature birth between the two groups (P>0.05). In conclusion, the expression levels of AGEs, visfatin and IL-6 in placental tissues of GDM pregnant women are positively correlated with MDA. There is a significant negative correlation between APN and MDA, and they play an important role in the pathogenesis of GDM.

The expression of sirtuins, superoxide dismutase, and lipid peroxidation status in peripheral blood from patients with diabetes and hypothyroidism

BACKGROUND

Sirtuin 1 (SIRT1) and sirtuin 3 (SIRT3) proteins have an important role in counteracting oxidative stress. Although diabetes and hypothyroidism (HT) are both characterized by oxidative stress, the mechanisms are not fully understood. This study investigated the effects of type 1 diabetes (T1D), type 2 diabetes (T2D), and HT on the expression levels of SIRT1, SIRT3, and manganese superoxide dismutase (SOD2).

METHODS

Gene expression of SIRT1, SIRT3, and SOD2 was measured using real-time PCR. The protein expression of SOD2 and lipid peroxidation (thiobarbituric acid reactive substances) was measured by the TBARS Assay kit and enzyme-linked immunosorbent assay (ELISA) respectively.

RESULTS

The results showed that the SIRT1 and SIRT3 levels were lower in peripheral blood samples from patients with T1D, T2D, or HT than in healthy individuals. Interestingly, the mRNA and protein expression levels of SOD2 were higher in all three patient groups. Lipid peroxidation was higher in the patients with HT than in the healthy individuals.

CONCLUSIONS

These results indicate alterations in the expression levels of sirtuins and superoxide dismutase in diabetes and HT, which may be related, at least in part, to the oxidative stress. Identifying such alterations in those patients will pave the way towards the development of drugs to enhance SIRT1 and SIRT3 expression and their activity to prevent the damaging effect of oxidative stress.

Aberrant expression of oxidative stress related proteins affects the pregnancy outcome of gestational diabetes mellitus patients

Gestational diabetemellitus (GDM) is a condition whereby a mother's glucose tolerance is impaired with onset or first recognition during pregnancy which is not either type 1 or type 2 diabetes mellitus. Oxidative stress plays an essential role in diabetes, however, whether it also includes in GDM has not been fully clarified. Therefore, we investigated the changes of oxidative stress biomarkers and their relationship with pregnancy outcomes in patients with GDM. The serum and placenta were collected for absorbance-based assay and immunohistochemistry assay (IHC). The patients' clinical information was collected and the pregnancy outcome was tracked. It was found that elder age is a risk factor to result in GDM. Moreover, GDM patients showed poor clinical factors or outcomes including higher prepregnancy weight and BMI value, premature delivery, higher rates of cesarean delivery, macrosomia, premature rupture of fetal membranes (PROM). Increasing serum MDA level and decline GSH and SOD levels were observed in GDM patients. Meanwhile, HO-1, Nrf2 and NQO1 overexpressed in GDM placental tissues. In the GDM group, MDA level was negatively associated with prepregnancy weight, while, SOD level was positively correlated with neonatal birth weight. We found an intensive relationship between SOD content and preterm birth in the GDM group. There is no significant difference between the level of MDA/GSH and neonatal birth weight as well as preterm birth. MDA, GSH and SOD levels were not associated with an increased risk of cesarean delivery or PROM. This study indicates aberrant expression of oxidative stress related proteins affects the pregnancy outcome of GDM patients.

Expression Profile of Diabetes-Related Genes Associated with Leukocyte Sirtuin 1 Overexpression in Gestational Diabetes

Although compelling evidence indicates that Sirtuin 1 (SIRT1) plays a prominent role in type 2 diabetes, its relationship with gestational diabetes (GDM) remains elusive. This study was aimed at identifying diabetes-related genes and cellular pathways linked to changes of leukocyte SIRT1 expression at the time of GDM diagnosis. For this purpose, 122 GDM patients were screened for leukocyte SIRT1 expression, and two subgroups were distinguished, namely GDM/SIRT1(↑) (n = 30, p < 0.05) and GDM/SIRT1(↔) (n = 92, p > 0.05), with significant and insignificant changes in leukocyte SIRT1 expression compared to a normal glucose tolerant (NGT) group (n = 41), respectively. PCR array analysis identified 11 diabetes-related genes with at least a ± 2-fold difference in expression in GDM/SIRT1(↑) patients (n = 9) vs. NGT controls (n = 7); in addition, significant differences in the expression of four of the six investigated genes were confirmed between the entire GDM/SIRT1(↑) group and the whole NGT group (p < 0.05). Interestingly, of these four genes, only ACLY expression was found to significantly differ between GDM/SIRT1(↑) and GDM/SIRT1(↔). This study demonstrates that under hyperglycemic conditions, leukocyte SIRT1 overexpression is accompanied by an over-abundance of three transcripts and an under-abundance of another; these four govern related metabolism, inflammation, and transport functions, suggesting that such alterations might represent systemic biological adaptations with a unique ACLY under-expression in GDM/SIRT1(↑) women.