Oxidant balance markers at birth in relation to glycemic and acid-base parameters

Genome-wide screening of m6A profiling of cutaneous wound healing in diabetic mice

OBJECTIVE

Impaired wound healing in diabetes mellitus (DM) is a major health burden on patients, their families, and society. The present study aimed to systematically profile the m6A modification landscape in cutaneous wounds in a diabetic mouse model.

APPROACH

Diabetes was induced in mice through a single intraperitoneal injection of streptozotocin (STZ); a single intraperitoneal injection of PBS was made in control mice for comparisons. Both groups then received an 8-mm diameter, full-thickness dorsal body wound with a biopsy punch. Five days after wound surgery, western blot analysis of harvested wound tissues from both groups was used to assess the expression of m6A-related enzymes. Genome-wide profiling of m6A-tagged transcripts was performed through MeRIP-seq and RNA-seq.

RESULTS

ALKBH5, an m6A eraser, was significantly upregulated, while METTL3, METTL14, and WTAP, m6A writers, were markedly downregulated in the diabetic wounds. Additionally, a total of 1335 m6A peaks were differentially expressed in MeRIP-seq and RNA-seq analyses, with 558 upregulated and 777 downregulated peaks. Finally, there was hypomethylated and hypermethylated differentiation at the gene and transcript levels.

INNOVATION

The present study was the first to reveal the m6A landscape in diabetic wounds in an animal model.

CONCLUSION

This study, by deeply analyzing the role of m6A modifications in diabetic wound healing, provides new insights and understanding into the molecular mechanisms of diabetic wound healing. Future research could further explore how m6A modifications regulate the wound healing process, thereby offering new potential targets for the treatment of diabetic wounds.

DNA damage and its cellular response in mother and fetus exposed to hyperglycemic environment

The increased production of reactive oxygen species (ROS) plays a key role in pathogenesis of diabetic complications. ROS are generated by exogenous and endogenous factors such as during hyperglycemia. When ROS production exceeds the detoxification and scavenging capacity of the cell, oxidative stress ensues. Oxidative stress induces DNA damage and when DNA damage exceeds the cellular capacity to repair it, the accumulation of errors can overwhelm the cell resulting in cell death or fixation of genome mutations that can be transmitted to future cell generations. These mutations can lead to and/or play a role in cancer development. This review aims at (i) understanding the types and consequences of DNA damage during hyperglycemic pregnancy; (ii) identifying the biological role of DNA repair during pregnancy, and (iii) proposing clinical interventions to maintain genome integrity. While hyperglycemia can damage the maternal genetic material, the impact of hyperglycemia on fetal cells is still unclear. DNA repair mechanisms may be important to prevent the deleterious effects of hyperglycemia both in mother and in fetus DNA and, as such, prevent the development of diseases in adulthood. Hence, in clinical practice, maternal glycemic control may represent an important point of intervention to prevent the deleterious effects of maternal hyperglycemia to DNA.

Effects of uncomplicated vaginal delivery and epidural analgesia on fetal arterial acid-base parameters at birth in gestational diabetes

AIM

To investigate the effects of uncomplicated vaginal delivery and epidural analgesia on fetal acid-base parameters in women with gestational diabetes (GDM) compared with controls.

METHODS

A retrospective case-control study of 142 women with gestational diabetes and 284 controls. To evaluate the effect of diabetes and analgesia on acid-base status correcting for potential confounders we used ordered logistic equations including quartiles of fetal arterial acid-base parameters collected at birth as outcomes and categories of diabetes and epidural analgesia as explanatory variables.

RESULTS

In the GDM group cord base deficit (-2.63 mmol/l, interquartile range [IQR]=4.2 to -0.65 mmol/l vs. -1.9 mmol/l, IQR=-3.3 to -0.2 mmol/l, p=0.009, odds ratio (OR)=1.51, 95% confidence interval (CI)=1.04-2.18) was lower and concentration of calcium higher (1.49 mmol/l, IQR=1.42-1.56 mmol/l vs. 1.47 mmol/l, IQR=1.41-1.51 mmol/l, p=0.009, OR=1.69, 95% CI=1.12-2.56) compared with controls. Epidural analgesia in the GDM group was associated with reduced cord concentration of glucose (84.0mg/dl [4.7 mmol/l], IQR=70-103.3mg/dl vs. 92.5mg/dl [5.1 mmol/l], IQR=76.5-121.8 mg/dl, p=0.004), lactate (2.65 mmol/l (IQR=1.80-4.20) vs. 3.70 mmol/l (IQR=2.90-5.55 mmol/l), p=0.002) and less pronounced base deficit (-2.05 mmol/l, IQR=-3.90 to -0.17 mmol/l vs. -2.8, IQR=-5.57 to -1.05 mmol/l, p=0.01, OR=0.7, 95% CI=0.49-0.99).

CONCLUSIONS

In uncomplicated pregnancies and deliveries, well-controlled gestational diabetes mellitus has potentially significant detrimental effects on fetal acid-base status at birth. Epidural analgesia reduces cord arterial glucose and lactates.

Lutein administration to pregnant women with gestational diabetes mellitus is associated to a decrease of oxidative stress in newborns

Oxidative stress (OS) is defined as an imbalance between pro- and antioxidant factors that can lead to cellular and tissue damage. Under condition of gestational diabetes, OS is exacerbated and can cause vascular dysfunction in the placenta, leading to fetal and perinatal complications. We investigated the oxidative status of diabetic pregnant women and of their babies. A group of those diabetic women received lutein, and another group did not receive anything. In order to verify a possible antioxidant function of lutein, we compared the OS values of the two groups. OS appeared lower in treated gravidas than in untreated ones; however, there was not a statistically significant difference between the two groups. As far as newborns are concerned, there was a significant difference of OS values between babies born to mothers treated with lutein and newborns to mothers untreated at 2 h of life. However, at 48 h, there was not a significant difference between the two groups. In conclusion, lutein administration during pregnancy significantly reduced neonatal OS at birth. Further studies are necessary to evaluate the effects of combined administration to mother and infants.

Amniotic fluid oxidative and nitrosative stress biomarkers correlate with fetal chronic hypoxia in diabetic pregnancies

BACKGROUND

In spite of improvement in obstetrical care, pregnancy in women with type 1 diabetes mellitus is associated with increased perinatal morbidity and mortality. Hyperglycemia during pregnancy causes excessive fetal growth and chronic fetal hypoxia as reflected in increased erythropoietin (EPO) levels in amniotic fluid (AF).

OBJECTIVES

We hypothesized that the degree of fetal hypoxia would correlate with fetal oxidative and nitrosative stress as evidenced ty the concentration of specific biomarkers in AF.

MATERIAL AND METHODS

19 pregnant women with type 1 or insulin-treated gestational diabetes mellitus were studied. AF samples were collected and processed for EPO, meta-tyrosine, nitro-tyrosine and 8-hydroxy-2-deoxiguanosine by chemiluminescent immunoassay and high-performance liquid chromatography coupled to tandem mass spectrometry methods, respectively.

RESULTS

The mean (SD) of the last HbA1c concentration before delivery was 7.7% (1.1). Median gestational age was 258 days (range 231-268). Birth weight was 3,868 ± 695 g with a z-score >2 SD in 47% of the cases. A significant correlation was found between the concentrations of AF EPO and meta-tyrosine/phenylalanine ratio (p < 0.001), nitro-tyrosine (p < 0.01) and 8-oxo-dG/2dG ratio (p < 0.001).

CONCLUSIONS

We confirmed that fetuses of type 1 diabetes or insulin-treated gestational diabetes pregnancies experience chronic hypoxia as reflected by increased EPO concentrations in AF near term. Moreover, EPO levels significantly correlated with the concentration of oxidative and nitrosative stress biomarkers in AF. This pro-oxidant status may predispose newborn infants to poor postnatal adaptation and early neonatal complications.

Care of the infant of the diabetic mother

Gestational diabetes mellitus (GDM) from all causes of diabetes is the most common medical complication of pregnancy and is increasing in incidence, particularly as type 2 diabetes continues to increase worldwide. Despite advances in perinatal care, infants of diabetic mothers (IDMs) remain at risk for a multitude of physiologic, metabolic, and congenital complications such as preterm birth, macrosomia, asphyxia, respiratory distress, hypoglycemia, hypocalcemia, hyperbilirubinemia, polycythemia and hyperviscosity, hypertrophic cardiomyopathy, and congenital anomalies, particularly of the central nervous system. Overt type 1 diabetes around conception produces marked risk of embryopathy (neural tube defects, cardiac defects, caudal regression syndrome), whereas later in gestation, severe and unstable type 1 maternal diabetes carries a higher risk of intrauterine growth restriction, asphyxia, and fetal death. IDMs born to mothers with type 2 diabetes are more commonly obese (macrosomic) with milder conditions of the common problems found in IDMs. IDMs from all causes of GDM also are predisposed to later-life risk of obesity, diabetes, and cardiovascular disease. Care of the IDM neonate needs to focus on ensuring adequate cardiorespiratory adaptation at birth, possible birth injuries, maintenance of normal glucose metabolism, and close observation for polycythemia, hyperbilirubinemia, and feeding intolerance.

Umbilical cord oxidative stress in infants of diabetic mothers and its relation to maternal hyperglycemia

AIMS

There is growing body of evidence that oxidative stress plays an important role in the pathogenesis of diabetes mellitus (DM) and in development of maternal and fetal complications of diabetic pregnancies. The aim of the present study was to investigate total antioxidant capacity (TAC), total oxidant status (TOS), and oxidative stress index (OSI) in infants of diabetic mothers (IDM) and to reveal the influence of maternal hyperglycemia on these parameters.

METHODS

A prospective controlled study was conducted between March 2010 and November 2010. Umbilical cord blood was taken from IDM and controls for TAC and TOS measurement, and OSI was calculated. IDM were divided into two groups, either of mothers treated with insulin during pregnancy or of those treated with a carbohydrate-restricted diet.

RESULTS

Thirty-six IDM and 14 infants born to non-diabetic mothers were enrolled. Infants of insulin-treated mothers (group 1) and infants of mothers managed with a carbohydrate-restricted diet (group 2) had significantly higher TOS (p < 0.001 and p = 0.001, respectively) and OSI (p < 0.001 and p = 0.001, respectively) levels compared to controls. However, TAC levels were similar in all three groups. Maternal HbA(1c) values were correlated to TOS (p < 0.001, r = 0.694) and OSI (p < 0.001, r = 0.683).

CONCLUSIONS

Oxidative stress is increased in IDM, and a significant relation exists between the degree of maternal hyperglycemia in pregnancy and oxidative stress in the newborn at birth.