Impact of fetal and neonatal environment on beta cell function and development of diabetes

Third-trimester fetal pancreas imaging in uncomplicated pregnancies and association with pregnancy outcomes

OBJECTIVE

To examine third-trimester sonographic imaging of the fetal pancreas in uncomplicated pregnancies and its association with pregnancy outcomes.

METHODS

This was a prospective cohort study including 274 pregnant women. Uncomplicated pregnancies in the third trimester (28-40 weeks) were included in the study. Maternal chronic disease, pregnancy-related disorders such as hypertension, diabetes, cholestasis, smoking, and fetal abnormalities were determined as exclusion criteria. Sonographic fetal pancreatic measurement and echogenicity were evaluated in all participants. For intra-observer reliability, each participant's fetal pancreatic circumference was measured two times. The echogenicity of the pancreas was compared with the liver and ribs and classified as grade 1, 2, and 3. The pregnancy outcomes of all participants were obtained from the hospital digital registration system.

RESULTS

The average fetal pancreatic circumference in the third trimester was 70.7 ± 0.6 mm (median, 70 [44-100.7]), with high intra-observer agreement (ICC 0.996 [0.995; 0.997]). A significant positive correlation was found between pancreatic circumference, body mass index (BMI), gestational age, and birth weight. Pancreatic measurements were significantly higher in composite adverse outcomes cases that included at least one of respiratory distress syndrome, hyperbilirubinemia, neonatal pneumonia, infection, and sepsis (p < 0.001). No relationship was found between pancreatic echogenicity and perinatal outcomes.

CONCLUSION

Fetal pancreas size was positively correlated with gestational age, BMI, and birth weight, and increased fetal pancreas size was associated with composite adverse neonatal outcomes.

Long-term Risk for Type 1 Diabetes and Obesity in Early Term Born Offspring: A Systematic Review and Meta-Analysis

CONTEXT

Prematurity increases the long-term risks for endocrine and metabolic morbidity of offspring, but there is uncertainty regarding the risks for early-term deliveries (370/7-386/7 weeks of gestation).

OBJECTIVE

We aim to evaluate whether early-term deliveries increase the long-term risk for type 1 diabetes and obesity of offspring up to the age of 18 years compared with full-term children. PubMed, Medline, and EMBASE were searched. Observational cohort studies addressing the association between early-term delivery and long-term risk for type 1 diabetes and obesity, were included. Two independent reviewers extracted data and assessed risk of bias. Pooled relative risks (RRs) and heterogeneity were determined. Publication bias was assessed by funnel plots with Egger's regression line and contours, and sensitivity analyses were performed.

RESULTS

Eleven studies were included following a screen of 7500 abstracts. All studies were scored as high quality according to the Newcastle-Ottawa Quality Assessment Scale. Early-term delivery was significantly associated with an increased risk for type 1 diabetes (RR 1.19, 1.13-1.25), while the association was weaker for overweight and obesity (RR 1.05, 0.97-1.12). It is challenging to determine whether the association between early-term births and long-term morbidity represents a cause and effect relationship or is attributable to confounders. Most of the included studies adjusted for at least some possible confounders.

CONCLUSION

Compared with full-term offspring, early-term delivery poses a modest risk for long-term pediatric type 1 diabetes. Our analysis supports that, whenever medically possible, elective delivery should be avoided before 39 completed weeks of gestation.

Relationship between insulin and Netrin-1/DCC guidance cue pathway regulation in the prefrontal cortex of rodents exposed to prenatal dietary restriction

Fetal restriction (FR) alters insulin sensitivity, but it is unknown how the metabolic profile associated with restriction affects development of the dopamine (DA) system and DA-related behaviors. The Netrin-1/DCC guidance cue system participates in maturation of the mesocorticolimbic DA circuitry. Therefore, our objective was to identify if FR modifies Netrin-1/DCC receptor protein expression in the prefrontal cortex (PFC) at birth and mRNA in adulthood in rodent males. We used cultured HEK293 cells to assess if levels of miR-218, microRNA regulator of DCC, are sensitive to insulin. To assess this, pregnant dams were subjected to a 50% FR diet from gestational day 10 until birth. Medial PFC (mPFC) DCC/Netrin-1 protein expression was measured at P0 at baseline and Dcc/Netrin-1 mRNA levels were quantified in adults 15 min after a saline/insulin injection. miR-218 levels in HEK-293 cells were measured in response to insulin exposure. At P0, Netrin-1 levels are downregulated in FR animals in comparison to controls. In adult rodents, insulin administration results in an increase in Dcc mRNA levels in control but not FR rats. In HEK293 cells, there is a positive correlation between insulin concentration and miR-218 levels. Since miR-218 is a Dcc gene expression regulator and our in vitro results show that insulin regulates miR-218 levels, we suggest that FR-induced changes in insulin sensitivity could be affecting Dcc expression via miR-218, impacting DA system maturation and organization. As fetal adversity is linked to nonadaptive behaviors later in life, this may contribute to early identification of vulnerability to chronic diseases associated with fetal adversity.

Glucose-stimulated insulin secretion depends on FFA1 and Gq in neonatal mouse islets

AIMS/HYPOTHESIS

After birth, the neonatal islets gradually acquire glucose-responsive insulin secretion, a process that is subjected to maternal imprinting. Although NEFA are major components of breastmilk and insulin secretagogues, their role for functional maturation of neonatal beta cells is still unclear. NEFA are the endogenous ligands of fatty acid receptor 1 (FFA1, encoded by Ffar1 in mice), a Gq-coupled receptor with stimulatory effect on insulin secretion. This study investigates the role of FFA1 in neonatal beta cell function and in the adaptation of offspring beta cells to parental high-fat feeding.

METHODS

Wild-type (WT) and Ffar1-/- mice were fed high-fat (HFD) or chow diet (CD) for 8 weeks before mating, and during gestation and lactation. Blood variables, pancreas weight and insulin content were assessed in 1-, 6-, 11- and 26-day old (P1-P26) offspring. Beta cell mass and proliferation were determined in P1-P26 pancreatic tissue sections. FFA1/Gq dependence of insulin secretion was evaluated in isolated islets and INS-1E cells using pharmacological inhibitors and siRNA strategy. Transcriptome analysis was conducted in isolated islets.

RESULTS

Blood glucose levels were higher in CD-fed Ffar1-/- P6-offspring compared with CD-fed WT P6-offspring. Accordingly, glucose-stimulated insulin secretion (GSIS) and its potentiation by palmitate were impaired in CD Ffar1-/- P6-islets. In CD WT P6-islets, insulin secretion was stimulated four- to fivefold by glucose and five- and sixfold over GSIS by palmitate and exendin-4, respectively. Although parental HFD increased blood glucose in WT P6-offspring, it did not change insulin secretion from WT P6-islets. In contrast, parental HFD abolished glucose responsiveness (i.e. GSIS) in Ffar1-/- P6-islets. Inhibition of Gq by FR900359 or YM-254890 in WT P6-islets mimicked the effect of Ffar1 deletion, i.e. suppression of GSIS and of palmitate-augmented GSIS. The blockage of Gi/o by pertussis toxin (PTX) enhanced (100-fold) GSIS in WT P6-islets and rendered Ffar1-/- P6-islets glucose responsive, suggesting constitutive activation of Gi/o. In WT P6-islets, FR900359 cancelled 90% of PTX-mediated stimulation, while in Ffar1-/- P6-islets it completely abolished PTX-elevated GSIS. The secretory defect of Ffar1-/- P6-islets did not originate from insufficient beta cells, since beta cell mass increased with the offspring's age irrespective of genotype and diet. In spite of that, in the breastfed offspring (i.e. P1-P11) beta cell proliferation and pancreatic insulin content had a genotype- and diet-driven dynamic. Under CD, the highest proliferation rate was reached by the Ffar1-/- P6 offspring (3.95% vs 1.88% in WT P6), whose islets also showed increased mRNA levels of genes (e.g. Fos, Egr1, Jun) typically high in immature beta cells. Although parental HFD increased beta cell proliferation in both WT (4.48%) and Ffar1-/- (5.19%) P11 offspring, only the WT offspring significantly increased their pancreatic insulin content upon parental HFD (5.18 µg under CD to 16.93 µg under HFD).

CONCLUSIONS/INTERPRETATION

FFA1 promotes glucose-responsive insulin secretion and functional maturation of newborn islets and is required for adaptive offspring insulin secretion in the face of metabolic challenge, such as parental HFD.

Pathomechanisms of Prenatally Programmed Adult Diseases

Based on epidemiological observations Barker et al. put forward the hypothesis/concept that an adverse intrauterine environment (involving an insufficient nutrient supply, chronic hypoxia, stress, and toxic substances) is an important risk factor for the development of chronic diseases later in life. The fetus responds to the unfavorable environment with adaptive reactions, which ensure survival in the short run, but at the expense of initiating pathological processes leading to adult diseases. In this review, the major mechanisms (including telomere dysfunction, epigenetic modifications, and cardiovascular-renal-endocrine-metabolic reactions) will be outlined, with a particular emphasis on the role of oxidative stress in the fetal origin of adult diseases.

Chemical Compounds and Ambient Factors Affecting Pancreatic Alpha-Cells Mass and Function: What Evidence?

The exposure to different substances present in the environment can affect the ability of the human body to maintain glucose homeostasis. Some review studies summarized the current evidence about the relationships between environment and insulin resistance or beta-cell dysfunction. Instead, no reviews focused on the relationships between the environment and the alpha cell, although in recent years clear indications have emerged for the pivotal role of the alpha cell in glucose regulation. Thus, the aim of this review was to analyze the studies about the effects of chemical, biological, and physical environmental factors on the alpha cell. Notably, we found studies focusing on the effects of different categories of compounds, including air pollutants, compounds of known toxicity present in common objects, pharmacological agents, and compounds possibly present in food, plus studies on the effects of physical factors (mainly heat exposure). However, the overall number of relevant studies was limited, especially when compared to studies related to the environment and insulin sensitivity or beta-cell function. In our opinion, this was likely due to the underestimation of the alpha-cell role in glucose homeostasis, but since such a role has recently emerged with increasing strength, we expect several new studies about the environment and alpha-cell in the near future.

Effect of excessive gestational weight gain on insulin sensitivity and insulin kinetics in women with overweight/obesity

OBJECTIVE

Obesity increases the risk for pregnancy complications and maternal hyperglycemia. The Institute of Medicine developed guidelines for gestational weight gain (GWG) targets for women with overweight/obesity, but it is unclear whether exceeding these targets has adverse effects on maternal glucose metabolism.

METHODS

Insulin sensitivity (assessed using the Matsuda Insulin Sensitivity Index), β-cell function (assessed as insulin secretion rate in relation to plasma glucose), and plasma insulin clearance rate were evaluated using a frequently sampled oral glucose tolerance test at 15 and 35 weeks of gestation in 184 socioeconomically disadvantaged African American women with overweight/obesity.

RESULTS

Insulin sensitivity decreased, whereas β-cell function and insulin clearance increased from 15 to 35 weeks of gestation in the entire group. Compared with women who achieved the recommended GWG, excessive GWG was associated with a greater decrease in insulin sensitivity between 15 and 35 weeks. β-cell function and plasma insulin clearance were not affected by excessive GWG.

CONCLUSIONS

These data demonstrate that gaining more weight during pregnancy than recommended by the Institute of Medicine is associated with functional effects on glucose metabolism.

Fetal Programming of the Endocrine Pancreas: Impact of a Maternal Low-Protein Diet on Gene Expression in the Perinatal Rat Pancreas

In rats, the time of birth is characterized by a transient rise in beta cell replication, as well as beta cell neogenesis and the functional maturation of the endocrine pancreas. However, the knowledge of the gene expression during this period of beta cell expansion is incomplete. The aim was to characterize the perinatal rat pancreas transcriptome and to identify regulatory pathways differentially regulated at the whole organ level in the offspring of mothers fed a regular control diet (CO) and of mothers fed a low-protein diet (LP). We performed mRNA expression profiling via the microarray analysis of total rat pancreas samples at embryonic day (E) 20 and postnatal days (P) 0 and 2. In the CO group, pancreas metabolic pathways related to sterol and lipid metabolism were highly enriched, whereas the LP diet induced changes in transcripts involved in RNA transcription and gene regulation, as well as cell migration and apoptosis. Moreover, a number of individual transcripts were markedly upregulated at P0 in the CO pancreas: growth arrest specific 6 (Gas6), legumain (Lgmn), Ets variant gene 5 (Etv5), alpha-fetoprotein (Afp), dual-specificity phosphatase 6 (Dusp6), and angiopoietin-like 4 (Angptl4). The LP diet induced the downregulation of a large number of transcripts, including neurogenin 3 (Neurog3), Etv5, Gas6, Dusp6, signaling transducer and activator of transcription 3 (Stat3), growth hormone receptor (Ghr), prolactin receptor (Prlr), and Gas6 receptor (AXL receptor tyrosine kinase; Axl), whereas upregulated transcripts were related to inflammatory responses and cell motility. We identified differentially regulated genes and transcriptional networks in the perinatal pancreas. These data revealed marked adaptations of exocrine and endocrine in the pancreas to the low-protein diet, and the data can contribute to identifying novel regulators of beta cell mass expansion and functional maturation and may provide a valuable tool in the generation of fully functional beta cells from stem cells to be used in replacement therapy.

Parental Programming of Offspring Health: The Intricate Interplay between Diet, Environment, Reproduction and Development

As adults, our health can be influenced by a range of lifestyle and environmental factors, increasing the risk for developing a series of non-communicable diseases such as type 2 diabetes, heart disease and obesity. Over the past few decades, our understanding of how our adult health can be shaped by events occurring before birth has developed into a well-supported concept, the Developmental Origins of Health and Disease (DOHaD). Supported by epidemiological data and experimental studies, specific mechanisms have been defined linking environmental perturbations, disrupted fetal and neonatal development and adult ill-health. Originally, such studies focused on the significance of poor maternal health during pregnancy. However, the role of the father in directing the development and well-being of his offspring has come into recent focus. Whereas these studies identify the individual role of each parent in shaping the long-term health of their offspring, few studies have explored the combined influences of both parents on offspring well-being. Such understanding is necessary as parental influences on offspring development extend beyond the direct genetic contributions from the sperm and oocyte. This article reviews our current understanding of the parental contribution to offspring health, exploring some of the mechanisms linking parental well-being with gamete quality, embryo development and offspring health.

The link between gestational diabetes and cardiovascular diseases: potential role of extracellular vesicles

Extracellular vesicles are critical mediators of cell communication. They encapsulate a variety of molecular cargo such as proteins, lipids, and nucleic acids including miRNAs, lncRNAs, circular RNAs, and mRNAs, and through transfer of these molecular signals can alter the metabolic phenotype in recipient cells. Emerging studies show the important role of extracellular vesicle signaling in the development and progression of cardiovascular diseases and associated risk factors such as type 2 diabetes and obesity. Gestational diabetes mellitus (GDM) is hyperglycemia that develops during pregnancy and increases the future risk of developing obesity, impaired glucose metabolism, and cardiovascular disease in both the mother and infant. Available evidence shows that changes in maternal metabolism and exposure to the hyperglycemic intrauterine environment can reprogram the fetal genome, leaving metabolic imprints that define life-long health and disease susceptibility. Understanding the factors that contribute to the increased susceptibility to metabolic disorders of children born to GDM mothers is critical for implementation of preventive strategies in GDM. In this review, we discuss the current literature on the fetal programming of cardiovascular diseases in GDM and the impact of extracellular vesicle (EV) signaling in epigenetic programming in cardiovascular disease, to determine the potential link between EV signaling in GDM and the development of cardiovascular disease in infants.

Hyperglycemia First Detected in Pregnancy in South Africa: Facts, Gaps, and Opportunities

This review contextualizes hyperglycemia in pregnancy from a South-African perspective. It aims to create awareness of the importance of hyperglycemia in pregnancy in low-middle-income countries. We address unanswered questions to guide future research on sub-Saharan African women with hyperglycemia first detected in pregnancy (HFDP). South African women of childbearing age have the highest prevalence of obesity in sub-Saharan Africa. They are predisposed to Type 2 diabetes (T2DM), the leading cause of death in South African women. T2DM remains undiagnosed in many African countries, with two-thirds of people living with diabetes unaware. With the South African health policy's increased focus on improving antenatal care, women often gain access to screening for non-communicable diseases for the first time in pregnancy. While screening practices and diagnostic criteria for gestational diabetes mellitus (GDM) differ amongst geographical areas in South Africa (SA), hyperglycemia of varying degrees is often first detected in pregnancy. This is often erroneously ascribed to GDM, irrespective of the degree of hyperglycemia and not overt diabetes. T2DM and GDM convey a graded increased risk for the mother and fetus during and after pregnancy, with cardiometabolic risk accumulating across the lifespan. Resource limitations and high patient burden have hampered the opportunity to implement accessible preventative care in young women at increased risk of developing T2DM in the broader public health system in SA. All women with HFDP, including those with true GDM, should be followed and undergo glucose assessment postpartum. In SA, studies conducted early postpartum have noted persistent hyperglycemia in a third of women after GDM. Interpregnancy care is advantageous and may attain a favourable metabolic legacy in these young women, but the yield of return following delivery is suboptimal. We review the current best evidence regarding HFDP and contextualize the applicability in SA and other African or low-middle-income countries. The review identifies gaps and shares pragmatic solutions regarding clinical factors that may improve awareness, identification, diagnosis, and management of women with HFDP.

Prenatal ethanol exposure induces dynamic changes of expression and activity of hepatic cytochrome P450 isoforms in male rat offspring

This study aimed at determining the effect of prenatal ethanol exposure (PEE) on the expression and activity of cytochrome P450 (CYP) isozymes at different life stages of male rat offspring. Pregnant Wistar rats were administered with ethanol (4 g/kg/d) intragastrically from gestational day (GD) 9-20. Male offspring's gene and activity of CYP isozymes were analyzed on GD 20 (only expression), postnatal day (PD) 84 and 196. Using aniline as probe, we compared the enzyme kinetics of hepatic CYP2E1 between two groups. Expression of CYP isozymes was examined in rat primary hepatocytes and human hepatic cell lines treated with ethanol or/and glucocorticoid. Gene level of Cyp1a2, 2b1, 2d1, 2e1, 3a1 and aryl hydrocarbon receptor were increased in PEE group on GD 20 and PD 84 and Cyp2e1 still exhibited an increasing trend on PD 196 compared with the control. PEE inhibited CYP2D1 and 2E1 activities in male offspring on PD 84. CYP activities in two groups became the same level on PD 196. PEE induced an opposite change in gene and protein level of hepatic CYP2E1 before and after birth. In consistent with lower protein level, aniline metabolism in PEE was weaker in liver microsome. Both single and combined use of ethanol or/and glucocorticoid increased CYPs expression in vitro. In conclusion, PEE programmed a higher gene and lower protein level of CYPs in male offspring, which dwindled with age. Impairment of protein levels and enzyme activities of CYPs may affect individual metabolism of endogenous and exogenous substances in early adulthood.

Association between fetal famine exposure and risk of type 2 diabetes: a prospective cohort study

The objective of this study was to explore the effects of fetal experience of famine on the onset of type 2 diabetes mellitus (T2DM) in adults. The analysis included 16 594 participants from the Kailuan Study who were free of diabetes at baseline (2006). According to the date of birth, the individuals born on October 1, 1962 - September 30, 1964, were divided into the non-exposed group (used as the reference group), individuals born on October 1, 1959 - September 30, 1961, were divided into the fetal exposure group, and the early childhood exposure group included those born on October 1, 1956 - September 30, 1958. The cumulative incidence of T2DM for each group was calculated and compared among the 3 groups, and the Cox regression model was used to analyze the effects of fetal famine experience on the risk of diabetes. During a median 10.27 years (170 358 person-years) (2006-2017), 3509 incident T2DM cases were identified, with a cumulative incidence rate of 19.46%. The cumulative incidences of T2DM in the non-exposed, fetal exposure, and early childhood exposure groups were 17.38%, 20.85%, and 20.65%, respectively (P < 0.01). After adjusting for confounding factors, the hazard ratio (HR) of T2DM in the fetal exposure group was 1.222 (95% confidence interval: 1.087-1.374, P < 0.01), compared with the reference group. The association was modified by sex and hypertension (both P interaction less than 0.05). Fetal famine exposure may increase the risk of developing T2DM in adults. This association was more pronounced among women and those with hypertension. Novelty: The association was modified by sex and hypertension. Long follow-up time.

Mechanisms Underlying the Expansion and Functional Maturation of β-Cells in Newborns: Impact of the Nutritional Environment

The functional maturation of insulin-secreting β-cells is initiated before birth and is completed in early postnatal life. This process has a critical impact on the acquisition of an adequate functional β-cell mass and on the capacity to meet and adapt to insulin needs later in life. Many cellular pathways playing a role in postnatal β-cell development have already been identified. However, single-cell transcriptomic and proteomic analyses continue to reveal new players contributing to the acquisition of β-cell identity. In this review, we provide an updated picture of the mechanisms governing postnatal β-cell mass expansion and the transition of insulin-secreting cells from an immature to a mature state. We then highlight the contribution of the environment to β-cell maturation and discuss the adverse impact of an in utero and neonatal environment characterized by calorie and fat overload or by protein deficiency and undernutrition. Inappropriate nutrition early in life constitutes a risk factor for developing diabetes in adulthood and can affect the β-cells of the offspring over two generations. A better understanding of these events occurring in the neonatal period will help developing better strategies to produce functional β-cells and to design novel therapeutic approaches for the prevention and treatment of diabetes.

Early-Life Exposure to Famine and Risk of Metabolic Associated Fatty Liver Disease in Chinese Adults

Background: Early-life exposure to the Chinese famine has been related to the risk of obesity, type 2 diabetes, and nonalcoholic fatty liver disease later in life. Nevertheless, the long-term impact of famine exposure on metabolic associated fatty liver disease (MAFLD), a recently proposed term to describe liver disease associated with known metabolic dysfunction, remains unknown. The aim of our study was to explore the relationship between early famine exposure and MAFLD in adulthood. Methods: A total of 26,821 participants (10,994 men, 15,827 women) were recruited from a cohort study of Chinese adults in Shanghai. We categorized participants into four famine exposure subgroups based on the birth year as nonexposed (1963–1967), fetal-exposed (1959–1962), childhood-exposed (1949–1958), and adolescence-exposed (1941–1948). MAFLD was defined as liver steatosis detected by ultrasound plus one of the following three criteria: overweight/obesity, type 2 diabetes, or evidence of metabolic dysregulation. Multivariable logistic regression models were performed to examine the association between famine exposure and MAFLD. Results: The mean ± standard deviation age of the participants was 60.8 ± 6.8 years. The age-adjusted prevalence of MAFLD was 38.3, 40.8, 40.1, and 36.5% for the nonexposed, fetal-exposed, childhood-exposed, and adolescence-exposed subgroups, respectively. Compared with nonexposed participants, fetal-exposed participants showed an increased risk of adulthood MAFLD (OR = 1.10, 95% CI 1.00–1.21). The significant association between fetal famine exposure and MAFLD was observed in women (OR = 1.22, 95% CI 1.08–1.37), but not in men (OR = 0.88, 95% CI 0.75–1.03). In age-balanced analyses combining pre-famine and post-famine births as the reference, women exposed to famine in the fetal stage still had an increased risk of MAFLD (OR = 1.15, 95% CI 1.05–1.26). Conclusions: Prenatal exposure to famine showed a sex-specific association with the risk of MAFLD in adulthood.

Identification and validation of reference genes for RT-qPCR analysis in fetal rat pancreas

The choice of reference gene is crucial for quantitative reverse transcriptase-polymerase chain reaction (RT-qPCR) assay. To screen and determine the suitable reference genes in fetal rat pancreas, we selected eight candidate reference genes (Gapdh, Actb, Rn18 s, B2m, Rpl13a, Tbp, Ywhaz and Ubc), and evaluated the constancy of gene expression from fetal rat pancreases in non-pathological situation and prenatal dexamethasone exposure (PDE) model, using four algorithms: GeNorm, NormFinder, Bestkeeper and Comparative ΔCt method. In addition, the alteration of mRNA levels of pancreatic insulin was compared between control and PDE groups to validate the reliability of selected reference genes for data normalization of RT-qPCR. The comprehensive ranking of reference genes under physiological condition was as follow: Gapdh > Actb > Ywhaz > Ubc > Rn18s > Rpl13a > B2m > Tbp (female); Actb > Ywhaz > Gapdh > Ubc > B2m > Rpl13a > Rn18 s | Tbp (male). The top ranking reference genes were also stably expressed in PDE fetal pancreas. The best reference gene combinations are: Ywhaz+Actb for female and Ywhaz+Gapdh for male fetal rat pancreas, respectively. Compared with low ranking or single reference gene, the change trend of insulin mRNA normalized by the best reference gene combination between control and PDE groups was more significant and consistent with that of serum insulin level. In conclusion, our results provided the optimal combination of stable reference genes for RT-qPCR assay in pancreatic developmental toxicity study.

Transient antibiotic-induced changes in the neonatal swine intestinal microbiota impact islet expression profiles reducing subsequent function

Neonatal antibiotics administered to human infants initiate gut microbiota dysbiosis that may have long-term effects on body weight and metabolism. We examined antibiotic-induced adaptations in pancreatic islets of the piglet, a well-accepted model of human infant microbiota and pancreas development. Neonatal piglets randomized to amoxicillin [30 mg/kg body wt/day; n = 7, antibiotic (ANTI)] or placebo [vehicle control; n = 7, control (CON)] from postnatal day (PND)0-13 were euthanized at PND7, 14, and 49. The metabolic phenotype along with functional, immunohistological, and transcriptional phenotypes of the pancreatic islets were studied. The gut microbiome was characterized by 16S rRNA gene sequencing, and microbial metabolites and microbiome-sensitive host molecules were measured. Compared with CON, ANTI PND7 piglets had elevated transcripts of genes involved in glucagon-like peptide 1 ((GLP-1) synthesis or signaling in islets (P < 0.05) coinciding with higher plasma GLP-1 (P = 0.11), along with increased tumor necrosis factor α (Tnf) (P < 0.05) and protegrin 1 (Npg1) (P < 0.05). Antibiotic-induced relative increases in Escherichia, Coprococcus, Ruminococcus, Dehalobacterium, and Oscillospira of the ileal microbiome at PND7 normalized after antibiotic withdrawal. In ANTI islets at PND14, the expression of key regulators pancreatic and duodenal homeobox 1 (Pdx1), insulin-like growth factor-2 (Igf2), and transcription factor 7-like 2 (Tcf7l2) was downregulated, preceding a 40% reduction of β-cell area (P < 0.01) and islet insulin content at PND49 (P < 0.05). At PND49, a twofold elevated plasma insulin concentration (P = 0.07) was observed in ANTI compared with CON. We conclude that antibiotic treatment of neonatal piglets elicited gut microbial changes accompanied by phasic alterations in key regulatory genes in pancreatic islets at PND7 and 14. By PND49, reduced β-cell area and islet insulin content were accompanied by elevated nonfasted insulin despite normoglycemia, indicative of islet stress.

Pancreatic progenitor epigenome maps prioritize type 2 diabetes risk genes with roles in development

Genetic variants associated with type 2 diabetes (T2D) risk affect gene regulation in metabolically relevant tissues, such as pancreatic islets. Here, we investigated contributions of regulatory programs active during pancreatic development to T2D risk. Generation of chromatin maps from developmental precursors throughout pancreatic differentiation of human embryonic stem cells (hESCs) identifies enrichment of T2D variants in pancreatic progenitor-specific stretch enhancers that are not active in islets. Genes associated with progenitor-specific stretch enhancers are predicted to regulate developmental processes, most notably tissue morphogenesis. Through gene editing in hESCs, we demonstrate that progenitor-specific enhancers harboring T2D-associated variants regulate cell polarity genes LAMA1 and CRB2. Knockdown of lama1 or crb2 in zebrafish embryos causes a defect in pancreas morphogenesis and impairs islet cell development. Together, our findings reveal that a subset of T2D risk variants specifically affects pancreatic developmental programs, suggesting that dysregulation of developmental processes can predispose to T2D.

Embryonic Exposure to Low Concentrations of Bisphenol A and S Altered Genes Related to Pancreatic β-Cell Development and DNA Methyltransferase in Zebrafish

Bisphenol A (BPA) and bisphenol S (BPS) are implicated in the development of metabolic disorders, such diabetes mellitus. However, the epigenetic mechanism underlying the pancreatic β-cell dysregulation for both BPA/BPS needs clarification. This exploratory study was designed to investigate whether embryonic exposure to low BPA/BPS concentrations impair early pancreatic β-cell differentiation as well as DNA methylation in its gene expression profile using an in vivo model, zebrafish. Zebrafish embryos were exposed to 0, 0.01, 0.03, 0.1, 0.3, and 1.0 µM BPA/BPS at 4-h post fertilization (hpf) until 120 hpf. BPA/BPS-induced effects on pancreatic-related genes, insulin gene, and DNA methylation-associated genes were assessed at developmental stages (24-120 hpf), while glucose level was measure at the 120 hpf. The insulin expression levels decreased at 72-120 hpf for 1.0 µM BPA, while 0.32 and 0.24-fold of insulin expression were elicited by 0.3 and 1 µM BPS respectively at 72 hpf. Significant elevation of glucose levels; 16.3% (for 1.0 µM BPA), 7.20% (for 0.3 µM BPS), and 74.09% (for 1.0 µM BPS) higher than the control groups were observed. In addition, pancreatic-related genes pdx-1, foxa2, ptfla, and isl1 were significantly interfered compared with the untreated group. Moreover, the maintenance methylation gene, dnmt1, was monotonically and significantly decreased at early stage of development following BPA exposure but remained constant for BPS treatment relative to the control group. DNMT3a and DNMT3b orthologs were distinctively altered following BPA/BPS embryonic exposure. Our data indicated that embryonic exposure to low concentration of BPA/BPS can impair the normal expressions of pancreatic-associated genes and DNA methylation pattern of selected genes in zebrafish early development.

Triglyceride-to-high density lipoprotein cholesterol ratio and triglyceride-glucose index in the perinatal period of neonates

BACKGROUND

Environmental factors and growth disturbances, either intra-uterine, or post-natal, can result in permanent changes in tissues and also long-term effects that may present themselves as pathological conditions in adulthood, including increased incidence of insulin resistance, impaired glucose tolerance, and also higher likelihood for diabetes mellitus. The triglyceride to glucose index (TyG) and triglyceride to high-density lipoprotein cholesterol ratio (TG/HDL-c) have been proposed as reliable and simple alternatives for the evaluation of insulin resistance. To date, there was limited data regarding the TyG index and TG/HDL-c ratio in the perinatal period of neonates. We aimed to investigate the possible relationships between HOMA-IR, TyG index, and TG/HDL-c in the cord blood of neonates.

MATERIALS-METHODS

One hundred and six pregnant women with singleton gestation who gave birth to full-term, normal-weight Turkish neonates without fetal distress were included in the study. The samples of maternal serum and cord blood in neonates were obtained after delivery.

RESULTS

Mean TyG index was 3.71 ± 0.38 and the mean TG/HDL-c ratio was 3.12 ± 3.00 in this group. Correlations were found between maternal age and neonate glucose levels and HOMA-IR (p < .05). HOMA-IR was negatively correlated with triglyceride, TG/HDL-c ratio, TyG index + TG/HDL, and positively correlated with HDL and TyG index.

CONCLUSIONS

Our study indicates that the TyG index and TG/HDL-C may be used as an indicator of insulin sensitivity in the perinatal period of neonates. However, the validity of these results should be tested in other centers with a larger neonate population in order to evaluate whether ethnic and racial diversity influence these relationships.

Pre-pregnancy body mass index in mothers, birth weight and the risk of type I diabetes in their offspring: A dose-response meta-analysis of cohort studies

BACKGROUND

The incidence of type I diabetes among children has increased significantly and the relationship between maternal pre-pregnancy Body Mass Index (BMI), Birth weight and risk of Type 1 diabetes in children (T1DMC) is controversial.

OBJECTIVE

This dose-response meta-analysis was performed to investigate the association between maternal Pre-Pregnancy Body-Mass Index, Birth Weight and the Risk of Childhood Type I Diabetes.

SEARCH STRATEGY

A comprehensive systematic search was conducted in MEDLINE/PubMed, SCOPUS, Cochrane, and Web of Science databases from inception to April 2019. Key search terms included "body mass index" OR "Birth weight" AND "Type 1 diabetes".

SELECTION CRITERIA

Peer-reviewed studies that reporting association between BMI or birth weight and type I diabetes in a retrospective or prospective study by appropriate estimates such as the hazard ratio (HR), risk ratio (RR), or odds ratio (OR) and the corresponding 95 % confidence intervals (CI).

DATA COLLECTION AND ANALYSIS

MOOSE guidelines were followed. Data were extracted by 2 researchers, independently. Combined hazard ratios (HRs) was evaluated by DerSimonian and Laird Random-effects model.

RESULTS

Two studies continuing four arms with 1,209,122 participants were eligible for pre-pregnancy BMI section meta-analysis and six studies were eligible for inclusion, providing 10,340,036 participants for birth weight section meta-analysis. Pooled results demonstrated a significant association between obesity and risk of T1DMC (HR: 1.30, 95 % CI: 1.16-1.46, I2 = 7%). The combined HR (95 % CI) showed lower risk of T1DMC in low birth weight infants (HR: 0.78, 95 % CI: 0.69-0.88, I2 = 0%) and higher risk of T1DMC in the high birth weight infants versus the normal category of birth weight (HR: 1.08, 95 % CI: 1.00-1.17, I2 = 31 %). There was a significant non-linear association between birth weight and risk of T1DMC in children (Coef =-0.00032, p = 0.001).

CONCLUSIONS AND RELEVANCE

This systematic review and meta-analysis identified high maternal BMI and High birth weight (HBW) increase risk of childhood T1DMC.

Effect of dietary myo-inositol supplementation on the insulin resistance and the prevention of gestational diabetes mellitus: study protocol for a randomized controlled trial

Background

Gestational diabetes mellitus (GDM) is defined as impaired glucose tolerance with onset or first recognition during pregnancy, which is characterized by an increased insulin resistance. Gestational diabetes mellitus is associated with pregnancy-related maternal and fetal morbidity (both antenatal and perinatal).

Myo-inositol has been suggested to improve insulin resistance in women with polycystic ovary syndrome.

The aim of this study is to examine the impact of myo-inositol supplementation during pregnancy on the incidence of gestational diabetes mellitus.

Methods

We will conduct a single-center, open-label, randomized controlled trial. A total of 160 healthy pregnant women with singleton pregnancy at 11–13⁺⁶ weeks of gestation will be randomly allocated in two groups: intervention group (N = 80) and control group (N = 80). The intervention group will receive myo-inositol and folic acid (4000 mg myo-inositol and 400 mcg folic acid daily) from 11 to 13⁺⁶ weeks of gestation until 26–28 weeks of gestation, while the control group will receive folic acid alone (400 mcg folic acid daily) for the same period of time as intervention group. The primary outcome will be gestational diabetes incidence rate at 26–28 weeks of gestation, according to the results of a 75 g oral glucose tolerance test held at 26–28 weeks of gestation. The secondary outcomes will include fasting blood glucose levels, glycated hemoglobin levels, insulin resistance level (evaluated by homeostasis model assessment of insulin resistance and Matsuda Index), and incidence rate of diet-treated gestational diabetes and diabetes requiring insulin therapy at 26–28 weeks of gestation.

Discussion

This trial will provide evidence for the effectiveness of myo-inositol supplementation during pregnancy in reducing the incidence of gestational diabetes mellitus.

Trial registration

ISRCTN registry: ISRCTN16142533. Registered on 9 March 2017.

Early-life Programming of Type 2 Diabetes Mellitus: Understanding the Association between Epigenetics/Genetics and Environmental Factors

Type 2 Diabetes Mellitus is an increasing public health problem that poses a severe social and economic burden affecting both developed and developing countries. Defects in insulin signaling itself are among the earliest indications that an individual is predisposed to the development of insulin resistance and subsequently Type 2 Diabetes Mellitus. To date, however, the underlying molecular mechanisms which result in resistance to the actions of insulin are poorly understood. Furthermore, it has been shown that maternal obesity is associated with an increased risk of obesity and insulin resistance in the offspring. However, the genetic and/or epigenetic modifications within insulin-sensitive tissues such as the liver and skeletal muscle, which contribute to the insulin-resistant phenotype, still remain unknown. More importantly, a lack of in-depth understanding of how the early life environment can have long-lasting effects on health and increased risk of Type 2 Diabetes Mellitus in adulthood poses a major limitation to such efforts. The focus of the current review is thus to discuss recent experimental and human evidence of an epigenetic component associated with components of nutritional programming of Type 2 Diabetes Mellitus, including altered feeding behavior, adipose tissue, and pancreatic beta-cell dysfunction, and transgenerational risk transmission.

Health impact of the Anthropocene: the complex relationship between gut microbiota, epigenetics, and human health, using obesity as an example

The growing prevalence of obesity worldwide poses a public health challenge in the current geological epoch, the Anthropocene. Global changes caused by urbanisation, loss of biodiversity, industrialisation, and land-use are happening alongside microbiota dysbiosis and increasing obesity prevalence. How alterations of the gut microbiota are associated with obesity and the epigenetic mechanism mediating this and other health outcome associations are in the process of being unveiled. Epigenetics is emerging as a key mechanism mediating the interaction between human body and the environment in producing disease. Evidence suggests that the gut microbiota plays a role in obesity as it contributes to different mechanisms, such as metabolism, body weight and composition, inflammatory responses, insulin signalling, and energy extraction from food. Consistently, obese people tend to have a different epigenetic profile compared to non-obese. However, evidence is usually scattered and there is a growing need for a structured framework to conceptualise this complexity and to help shaping complex solutions. In this paper, we propose a framework to analyse the observed associations between the alterations of microbiota and health outcomes and the role of epigenetic mechanisms underlying them using obesity as an example, in the current context of global changes within the Anthropocene.

The Impact of New Biomarkers and Drug Targets on Age-Related Disorders

The increase in the human lifespan has not been paralleled by an increase in healthy life. With the increase in the proportion of the aged population, there has been a natural increase in the prevalence of age-related disorders, such as Alzheimer's disease, type 2 diabetes mellitus, frailty, and various other disorders. A continuous rise in these conditions could lead to a widespread medical and social burden. There are now considerable efforts underway to address these deficits in preclinical and clinical studies, which include the use of better study cohorts, longitudinal designs, improved translation of data from preclinical models, multi-omics profiling, identification of new biomarker candidates and refinement of computational tools and databases containing relevant information. Such efforts will support future interdisciplinary studies and help to identify potential new targets that are amenable to therapeutic approaches such as pharmacological interventions to increase the human healthspan in parallel with the lifespan.

Developmental origins of type 2 diabetes: Focus on epigenetics

Traditionally, genetics and lifestyle are considered as main determinants of aging-associated pathological conditions. Accumulating evidence, however, suggests that risk of many age-related diseases is not only determined by genetic and adult lifestyle factors but also by factors acting during early development. Type 2 diabetes (T2D), an age-related disease generally manifested after the age of 40, is among such disorders. Since several age-related conditions, such as pro-inflammatory states, are characteristic of both T2D and aging, this disease is conceptualized by many authors as a kind of premature or accelerated aging. There is substantial evidence that intrauterine growth restriction (IUGR), induced by poor or unbalanced nutrient intake, exposure to xenobiotics, maternal substance abuse etc., may impair fetal development, thereby causing the fetal adipose tissue and pancreatic beta cell dysfunction. Consequently, persisting adaptive changes may occur in the glucose-insulin metabolism, including reduced capacity for insulin secretion and insulin resistance. These changes can lead to an improved ability to store fat, thus predisposing to T2D development in later life. The modulation of epigenetic regulation of gene expression likely plays a central role in linking the adverse environmental conditions early in life to the risk of T2D in adulthood. In animal models of IUGR, long-term persistent changes in both DNA methylation and expression of genes implicated in metabolic processes have been repeatedly reported. Findings from human studies confirming the role of epigenetic mechanisms in linking early-life adverse experiences to the risk for T2D in adult life are scarce compared to data from animal studies, mainly because of limited access to suitable biological samples. It is, however, convincing evidence that these mechanisms may also operate in human beings. In this review, theoretical models and research findings evidencing the role of developmental epigenetic variation in the pathogenesis of T2D are summarized and discussed.

Impact of Early Life or Intrauterine Factors and Socio-Economic Interaction on Diabetes - An Evidence on Thrifty Hypothesis

Diabetes mellitus is one of the most concerning non-communicable diseases worldwide. The prevalence of diabetes increased rapidly by the influence of socioeconomic interactions. The thrifty hypothesis postulates that certain genes that are involved in positive selection promote efficient fat deposition and storage. This is beneficial for the survival of mankind in adverse conditions. However, in this modern society, these genes have become disadvantageous as people are significantly less likely to experience famines and nutrition shortages. The socioeconomic development that has occurred during the 20th century induced abundance of food supplies in almost all regions of the world. This has led to a rapid rise in the prevalence of obesity, and type 2 diabetes as a consequence. Boom of diabetic pandemic in newly developed countries compare with others those who developed gradually can be explain by thrifty hypothesis, as a result of the difference in the exposure to environmental factors and famine by the ancestors leads. The globalization, urbanization, lack of physical activity, intake of high calorie food and migration is major cause of pandemic emergence of diabetes in high as well as middle and low-income countries.

DNA methylation markers in obesity, metabolic syndrome, and weight loss

The fact that not all individuals exposed to the same environmental risk factors develop obesity supports the hypothesis of the existence of underlying genetic and epigenetic elements. There is suggestive evidence that environmental stimuli, such as dietary pattern, particularly during pregnancy and early life, but also in adult life, can induce changes in DNA methylation predisposing to obesity and related comorbidities. In this context, the DNA methylation marks of each individual have emerged not only as a promising tool for the prediction, screening, diagnosis, and prognosis of obesity and metabolic syndrome features, but also for the improvement of weight loss therapies in the context of precision nutrition. The main objectives in this field are to understand the mechanisms involved in transgenerational epigenetic inheritance, and featuring the nutritional and lifestyle factors implicated in the epigenetic modifications. Likewise, DNA methylation modulation caused by diet and environment may be a target for newer therapeutic strategies concerning the prevention and treatment of metabolic diseases.

Nutritional recovery from a low-protein diet during pregnancy does not restore the kinetics of insulin secretion and Ca2+ or alterations in the cAMP/PKA and PLC/PKC pathways in islets from adult rats

We investigated the insulin release induced by glucose, the Ca²⁺ oscillatory pattern, and the cyclic AMP (cAMP)/protein kinase A (PKA) and phospholipase C (PLC)/protein kinase C (PKC) pathways in islets from adult rats that were reared under diets with 17% protein (C) or 6% protein (LP) during gestation, suckling, and after weaning and in rats receiving diets with 6% protein during gestation and 17% protein after birth (R). First-phase glucose-induced insulin secretion was reduced in LP and R islets, and the second phase was partially restored in the R group. Glucose stimulation did not modify intracellular Ca²⁺ concentration, but it reduced the Ca²⁺ oscillatory frequency in the R group compared with the C group. Intracellular cAMP concentration was higher and PKA-Cα expression was lower in the R and LP groups compared with the C group. The PKCα content in islets from R rats was lower than that in C and LP rats. Thus, nutritional recovery from a low-protein diet during fetal life did not repair the kinetics of insulin release, impaired Ca²⁺ handling, and altered the cAMP/PKA and PLC/PKC pathways.

Prenatal Malnutrition-Induced Epigenetic Dysregulation as a Risk Factor for Type 2 Diabetes

Type 2 diabetes (T2D) is commonly regarded as a disease originating from lifestyle-related factors and typically occurring after the age of 40. There is, however, consistent experimental and epidemiological data evidencing that the risk for developing T2D may largely depend on conditions early in life. In particular, intrauterine growth restriction (IUGR) induced by poor or unbalanced nutrient intake can impair fetal growth and also cause fetal adipose tissue and pancreatic β-cell dysfunction. On account of these processes, persisting adaptive changes can occur in the glucose-insulin metabolism. These changes can include reduced ability for insulin secretion and insulin resistance, and they may result in an improved capacity to store fat, thereby predisposing to the development of T2D and obesity in adulthood. Accumulating research findings indicate that epigenetic regulation of gene expression plays a critical role in linking prenatal malnutrition to the risk of later-life metabolic disorders including T2D. In animal models of IUGR, changes in both DNA methylation and expression levels of key metabolic genes were repeatedly found which persisted until adulthood. The causal link between epigenetic disturbances during development and the risk for T2D was also confirmed in several human studies. In this review, the conceptual models and empirical data are summarized and discussed regarding the contribution of epigenetic mechanisms in developmental nutritional programming of T2D.

Non-Coding RNA in Pancreas and β-Cell Development

In this review, we provide an overview of the current knowledge on the role of different classes of non-coding RNAs for islet and β-cell development, maturation and function. MicroRNAs (miRNAs), a prominent class of small RNAs, have been investigated for more than two decades and patterns of the roles of different miRNAs in pancreatic fetal development, islet and β-cell maturation and function are now emerging. Specific miRNAs are dynamically regulated throughout the period of pancreas development, during islet and β-cell differentiation as well as in the perinatal period, where a burst of β-cell replication takes place. The role of long non-coding RNAs (lncRNA) in islet and β-cells is less investigated than for miRNAs, but knowledge is increasing rapidly. The advent of ultra-deep RNA sequencing has enabled the identification of highly islet- or β-cell-selective lncRNA transcripts expressed at low levels. Their roles in islet cells are currently only characterized for a few of these lncRNAs, and these are often associated with β-cell super-enhancers and regulate neighboring gene activity. Moreover, ncRNAs present in imprinted regions are involved in pancreas development and β-cell function. Altogether, these observations support significant and important actions of ncRNAs in β-cell development and function.

The effect of Chinese famine exposure in early life on dietary patterns and chronic diseases of adults

OBJECTIVE

To assess the effect of famine exposure during early life on dietary patterns, chronic diseases, and the interaction effect between famine exposure and dietary patterns on chronic diseases in adulthood.

DESIGN

Cross-sectional study. Dietary patterns were derived by factor analysis. Multivariate quantile regression and log-binomial regression were used to evaluate the impact of famine exposure on dietary patterns, chronic diseases and the interaction effect between famine exposure and dietary patterns on chronic diseases, respectively.

SETTING

Hefei, China.

PARTICIPANTS

Adults aged 45-60 years (n 939).

RESULTS

'Healthy', 'high-fat and high-salt', 'Western' and 'traditional Chinese' dietary patterns were identified. Early-childhood and mid-childhood famine exposure were remarkably correlated with high intake of the traditional Chinese dietary pattern. Compared with the non-exposed group (prevalence ratio (PR); 95 % CI), early-childhood (3·13; 1·43, 6·84) and mid-childhood (2·37; 1·05, 5·36) exposed groups showed an increased PR for diabetes, and the early-childhood (2·07; 1·01, 4·25) exposed group showed an increased PR for hypercholesterolaemia. Additionally, relative to the combination of non-exposed group and low-dichotomous high-fat and high-salt dietary pattern, the combination of famine exposure in early life and high-dichotomous high-fat and high-salt dietary pattern in adulthood had higher PR for diabetes (4·95; 1·66, 9·05) and hypercholesterolaemia (3·71; 1·73, 7·60), and significant additive interactions were observed.

CONCLUSIONS

Having suffered the Chinese famine in childhood might affect an individual's dietary habits and health status, and the joint effect between famine and harmful dietary pattern could have serious consequences on later-life health outcomes.

The GLP-1 analog, liraglutide prevents the increase of proinflammatory mediators in the hippocampus of male rat pups submitted to maternal perinatal food restriction

Background

Perinatal maternal malnutrition is related to altered growth of tissues and organs. The nervous system development is very sensitive to environmental insults, being the hippocampus a vulnerable structure, in which altered number of neurons and granular cells has been observed. Moreover, glial cells are also affected, and increased expression of proinflammatory mediators has been observed. We studied the effect of Glucagon-like peptide-1 receptor (GLP-1R) agonists, liraglutide, which have very potent metabolic and neuroprotective effects, in order to ameliorate/prevent the glial alterations present in the hippocampus of the pups from mothers with food restriction during pregnancy and lactation (maternal perinatal food restriction—MPFR).

Methods

Pregnant Sprague-Dawley rats were randomly assigned to 50% food restriction (FR; n = 12) or ad libitum controls (CT, n = 12) groups at day of pregnancy 12 (GD12). From GD14 to parturition, pregnant FR and CT rats were treated with liraglutide (100 μg/kg) or vehicle. At postnatal day 21 and before weaning, 48 males and 45 females (CT and MPFR) were sacrificed. mRNA expression levels of interleukin-1β (IL1β), interleukin-6 (IL-6), nuclear factor-κβ, major histocompatibility complex-II (MHCII), interleukin 10 (IL10), arginase 1 (Arg1), and transforming growth factor (TGFβ) were assessed in the hippocampus by quantitative real-time polymerase chain reaction. Iba1 and GFAP-immunoreactivity were assessed by immunocytochemistry.

Results

The mRNA expression IL1β, IL6, NF-κB, and MHCII increased in the hippocampus of male but not in female pups from MPFR. In addition, there was an increase in the percentage of GFAP and Iba1-immupositive cells in the dentate gyrus compared to controls, indicating an inflammatory response in the brain. On the other hand, liraglutide treatment prevented the neuroinflammatory process, promoting the production of anti-inflammatory molecules such as IL10, TGFβ, and arginase 1, and decreasing the number and reactivity of microglial cells and astrocytes in the hippocampus of male pups.

Conclusion

Therefore, the GLP-1 analog, liraglutide, emerges as neuroprotective drug that minimizes the harmful effects of maternal food restriction, decreasing neuroinflammation in the hippocampus in a very early stage.

Diabetes in Pregnancy and MicroRNAs: Promises and Limitations in Their Clinical Application

Maternal diabetes is associated with an increased risk of complications for the mother and her offspring. The latter have an increased risk of foetal macrosomia, hypoglycaemia, respiratory distress syndrome, preterm delivery, malformations and mortality but also of life-long development of obesity and diabetes. Epigenetics have been proposed as an explanation for this long-term risk, and microRNAs (miRNAs) may play a role, both in short- and long-term outcomes. Gestation is associated with increasing maternal insulin resistance, as well as β-cell expansion, to account for the increased insulin needs and studies performed in pregnant rats support a role of miRNAs in this expansion. Furthermore, several miRNAs are involved in pancreatic embryonic development. On the other hand, maternal diabetes is associated with changes in miRNA both in maternal and in foetal tissues. This review aims to summarise the existing knowledge on miRNAs in gestational and pre-gestational diabetes, both as diagnostic biomarkers and as mechanistic players, in the development of gestational diabetes itself and also of short- and long-term complications for the mother and her offspring.

Developmental programming of aging trajectory

There is accumulating evidence that aging phenotype and longevity may be developmentally programmed. Main mechanisms linking developmental conditions to later-life health outcomes include persistent changes in epigenetic regulation, (re)programming of major endocrine axes such as growth hormone/insulin-like growth factor axis and hypothalamic-pituitary-adrenal axis and also early-life immune maturation. Recently, evidence has also been generated on the role of telomere biology in developmental programming of aging trajectory. In addition, persisting changes of intestinal microbiota appears to be crucially involved in these processes. In this review, experimental and epidemiological evidence on the role of early-life conditions in programming of aging phenotypes are presented and mechanisms potentially underlying these associations are discussed.

Association between famine exposure in early life and type 2 diabetes mellitus and hyperglycemia in adulthood: Results from the China Health And Retirement Longitudinal Study (CHARLS)

BACKGROUND

Studies have revealed the association between famine in early life and type 2 diabetes mellitus (T2DM) in adulthood. However, studies on the Great Chinese Famine were not conducted nationwide. Because of regional variations in the severity of this famine, the results of regional studies are limited. This study explored associations between famine and T2DM in adulthood in a nationwide study.

METHODS

The present study was performed on 7262 participants who were born between 1 October 1949 and 1 July 1966 using baseline data collected for the China Health And Retirement Longitudinal Study (CHARLS) in 2011. Participants were divided according to birthdate into cohorts with fetal, late, middle, and early childhood exposure and no exposure to famine. Logistic regression models were used to analyze the association between famine exposure in early life and the risk of T2DM and hyperglycemia in adulthood.

RESULTS

For females, the risk of hyperglycemia was higher for famine-exposed than not exposed cohort (odds ratios [OR] 1.34 and 95% confidence intervals [CIs]: 1.34 [1.04-1.74], 1.48 [1.15-1.90], 1.38 [1.06-1.79], and 1.57 [1.25-1.98] for fetal, early, middle, and late childhood exposure, respectively), and this association was even stronger in female participants who lived in rural areas before the age of 16 years. In males, the risk of T2DM was lower for the early and late childhood exposure than no exposure cohorts (OR [95% CIs]: 0.65 [0.49-0.86] and 0.74 [0.56-0.98], respectively). [Correction added on 23 July 2018, after first online publication: Parts of the above 'Results' section have been corrected to interchange the citation of the words 'late' and 'early'.] CONCLUSION: Exposure to famine during early life can increase the risk of hyperglycemia in female adults, but may decrease the risk of T2DM in males.

Fetal pancreatic Langerhans islets size in pregnancies with metabolic disorders

Objective: Metabolic disorders are a pandemic and increasing health problem. Women of childbearing age may also be affected, thus an abnormal metabolism may interfere with pregnancy short- and long-term outcomes, harming both mother and child. In the context of an abnormal maternal and intrauterine metabolic milieu the development of fetal organs, including pancreas, may be affected. Aim: To investigate the effects of pregnancy metabolic disorders on the morphology of pancreatic Langerhans islets in human late-third trimester stillborn fetuses. Methods: Samples from fetal pancreas underwent a quantitative histological evaluation to detect differences between pregnancy with (cases, n = 9) or without (controls, n = 6) abnormal metabolism. Results: Results show that the islets size increases in fetuses from dysmetabolic pregnancies and that this increment is related to both beta-cell hyperplasia and hypertrophy. Moreover, according to pregnancy and fetal metabolic disorders, a threshold of abnormal size of the islets has been identified. Above this threshold the size of fetal pancreatic Langerhans islets should be considered excessively increased. Conclusion: The study suggests that an accurate fetal pancreas analysis supplies an important tool in stillborn fetus, to discover metabolic disturbances that should be kept in mind and managed in future pregnancies.

Trefoil factor 3 in perinatal pancreas is increased by gestational low protein diet and associated with accelerated β-cell maturation

The endocrine pancreas expands markedly in the first postnatal days and the insulin producing β-cells initiate a functional maturation preceded by a morphological change of the islets of Langerhans. Trefoil factor 3 (TFF3) is a secreted peptide expressed in intestinal epithelia, where it promotes migration, but its role in the pancreas is not characterized. The aim of this study was to examine the expression and function of TFF3 in perinatal rat pancreas, ex vivo cultured fetal rat pancreas and in the rat β-cell line INS-1E. Control or gestational low-protein diet perinatal rat pancreas was harvested at embryonic day 20 (E20), day of birth (P0) and postnatal day 2 (P2). TFF3 mRNA was upregulated 4.5-fold at P0 vs. E20 and downregulated again at P2. In protein-undernourished pups induction of TFF3 at P0 was further increased to 9.7-fold and was increased at P2. TFF3 caused tyrosine phosphorylation of EGFR in INS-1E β-cells, and purified recombinant TFF3 increased both attachment and spreading of INS-1E β-cells. In ex vivo cultures of collagenase digested fetal rat pancreas, a model of perinatal β-cell maturation, TFF3 increased cellular spreading as well as insulin mRNA levels. TFF3 also increased the expression of Pref1/Dlk1 that shares similarities in expression and regulation with TFF3. These results suggest that TFF3 may promote adhesion and spreading of cells to accelerate β-cell maturation. This study indicates a functional role for TFF3 in pancreatic β-cell maturation in the perinatal period, which is altered by low protein diet during gestation.

The triglyceride-glucose index, an insulin resistance marker in newborns?

The study aims to assess the utility of the triglyceride-glucose index (TyG) as a marker of insulin resistance (IR) in neonates. TyG and the homeostatic model assessment (HOMA-IR) values were compared in 196 singleton, term normoweight and without distress newborns. A Decision Tree procedure (CHAID) was used to classify cases into groups or predict values of a dependent (Ln HOMA-IR) variable. Three nodes were drawn for TyG: ≤ 6.7, > 6.7-7.8 and > 7.8 (p < 0.0001; F = 20.52). The predictability of those TyG values vs HOMA-IR was statistically significant (p < 0.0001). It was neither affected by gender (p = 0.084), glucose challenge test (p = 0.138) classifications nor by the TyG node* glucose challenge test and TyG node*gender interactions (p = 0.456 and p = 0.209, respectively). Glucose, HOMA-IR, and the triglyceride/HDL cholesterol ratio increased progressively from node 1 to 3 for TyG while QUICKI decreased.

CONCLUSION

In conclusion, TyG appears to be a suitable tool for identifying IR at birth, justifying the further insulin determination in those neonates. TyG ≥ 7.8 is recommended as cut-off point in neonates. The need for a follow-up study to confirm the TyG as early IR marker is desirable.

WHAT IS KNOWN

• HOMA-IR and the triglyceride-glucose index (TyG) show a high correlation. • The TyG has been used as an insulin resistance marker in adults.

WHAT IS NEW

• This is the first study where TyG has been assessed in neonates. • TyG appears to be a suitable and cheap tool for identifying insulin resistance at birth.

Prenatal famine exposure, adulthood obesity patterns and risk of type 2 diabetes

Background

Prenatal exposure to famine and adulthood obesity have been independently related to the risk of type 2 diabetes; however, little is known about the joint effects of these risk factors at different stages of life on adulthood diabetes risk.

Methods

The analysis included 88 830 participants of the China Kadoorie Biobank, who were born around the time of the Chinese Great Famine and without diabetes, cardiovascular diseases, or cancer at baseline. We defined famine exposure subgroups as nonexposed (born between 1 October 1962 and 30 September 964), fetal-exposed (born between 1 October 1959 and 30 September 1961) and early-childhood exposed (born between 1 October 1956 and 30 September 1958). General obesity was assessed by body mass index (BMI: overweight ≥ 24.0, obesity ≥ 28.0) and abdominal obesity assessed by waist-to-hip ratio (WHR, men/women: moderate ≥ 0.90/0.85, high ≥ 0.95/0.90).

Results

During a median 7.3 years (642 552 person-years) of follow-up, we identified 1372 incident cases of type 2 diabetes. Compared with nonexposed and early-childhood exposed participants combined as a single comparison group, fetal-exposed participants showed an increased risk of diabetes in adulthood [hazard ratio (HR) = 1.25; 95% confidence interval (CI): 1.07-1.45]. The association between general obesity and diabetes was consistent across subgroups according to famine exposure (P for interaction > 0.05). A stronger association between abdominal obesity and diabetes was observed in the fetal-exposed subgroup than in other subgroups (P for interaction = 0.025 in the whole population). This interaction was more obvious in women (P = 0.013) but not in men (P = 0.699). Compared with normal-BMI and -WHR participants, those with both general (BMI ≥ 24.0) and abdominal (WHR ≥ 0.90/0.85) obesity in adulthood had 5.32 (95% CI: 3.81-7.43)-, 3.13 (2.48-3.94)- and 4.43 (3.45-5.68)-fold higher risks if these were carried during, before and after times of famine, respectively.

Conclusions

Coexistence of prenatal experience of undernutrition and abdominal obesity in adulthood was associated with a higher risk of type 2 diabetes.

Associations between birthweight, gestational age at birth and subsequent type 1 diabetes in children under 12: a retrospective cohort study in England, 1998-2012

AIMS/HYPOTHESIS

With genetics thought to explain only 40-50% of the total risk of type 1 diabetes, environmental risk factors in early life have been proposed. Previous findings from studies of type 1 diabetes incidence by birthweight and gestational age at birth have been inconsistent. This study aimed to investigate the relationships between birthweight, gestational age at birth and subsequent type 1 diabetes in England.

METHODS

Data were obtained from a population-based database comprising linked mother-infant pairs using English national Hospital Episode Statistics from 1998 to 2012. In total, 3,834,405 children, categorised by birthweight and gestational age at birth, were followed up through record linkage to compare their incidence of type 1 diabetes through calculation of multivariable-adjusted HRs.

RESULTS

Out of 3,834,405 children, 2969 had a subsequent hospital diagnosis of type 1 diabetes in childhood. Children born preterm (<37 weeks) or early term (37-38 weeks) experienced significantly higher incidence of type 1 diabetes than full term children (39-40 weeks) (HR 1.19 [95% CI 1.03, 1.38] and 1.27 [95% CI 1.16, 1.39], respectively). Children born at higher than average birthweight (3500-3999 g or 4000-5499 g) after controlling for gestational age experienced higher incidence of type 1 diabetes than children born at medium birthweight (3000-3499 g) (HR 1.13 [95% CI 1.03, 1.23] and 1.16 [95% CI 1.02, 1.31], respectively), while children at low birthweight (<2500 g) experienced lower incidence (0.81 [95% CI 0.67, 0.98]), signifying a statistically significant trend (p trend 0.001).

CONCLUSIONS/INTERPRETATION

High birthweight for gestational age and low gestational age at birth are both independently associated with subsequent type 1 diabetes. These findings help contextualise the debate about the potential role of gestational and early life environmental risk factors in the pathogenesis of type 1 diabetes, including the potential roles of insulin sensitivity and gut microbiota.

Synthesis: Deriving a Core Set of Recommendations to Optimize Diabetes Care on a Global Scale

BACKGROUND

Diabetes afflicts 382 million people worldwide, with increasing prevalence rates and adverse effects on health, well-being, and society in general. There are many drivers for the complex presentation of diabetes, including environmental and genetic/epigenetic factors.

OBJECTIVE

The aim was to synthesize a core set of recommendations from information from 14 countries that can be used to optimize diabetes care on a global scale.

METHODS

Information from 14 papers in this special issue of Annals of Global Health was reviewed, analyzed, and sorted to synthesize recommendations. PubMed was searched for relevant studies on diabetes and global health.

FINDINGS

Key findings are as follows: (1) Population-based transitions distinguish region-specific diabetes care; (2) biological drivers for diabetes differ among various populations and need to be clarified scientifically; (3) principal resource availability determines quality-of-care metrics; and (4) governmental involvement, independent of economic barriers, improves the contextualization of diabetes care. Core recommendations are as follows: (1) Each nation should assess region-specific epidemiology, the scientific evidence base, and population-based transitions to establish risk-stratified guidelines for diagnosis and therapeutic interventions; (2) each nation should establish a public health imperative to provide tools and funding to successfully implement these guidelines; and (3) each nation should commit to education and research to optimize recommendations for a durable effect.

CONCLUSIONS

Systematic acquisition of information about diabetes care can be analyzed, extrapolated, and then used to provide a core set of actionable recommendations that may be further studied and implemented to improve diabetes care on a global scale.

DNA Methylation Variability in a Single Locus of the RXRα Promoter from Umbilical Vein Blood at Term Pregnancy

DNA methylation status of RXRα gene promoter has been correlated with maternal diet during early pregnancy, and associated with offspring's adiposity and bone mineral content. In adult life, increased methylation of RXRα promoter region is associated with myocardium pathologies. Early growth response proteins (EGR) are zinc finger transcription factors associated with several cellular pathways such as inflammation, apoptosis, and cardiopathies. DNA-binding sequences of EGR proteins have been reported in the RXRα gene promoter using chromatin immunoprecipitation methods. Here, we used correlations between the maternal pre-pregnancy body mass index (p-BMI), gestational weight gain (GWG), and birth weight (BW) as indirect indicators of the maternal nutritional status as modifier of DNA methylation in the offspring. DNA methylation status from newborns' umbilical vein blood in full-term pregnancy was evaluated in a short sequence (116 pb) of the RXRα gene promoter that contains the elements of response sequence for EGR proteins. Fifty-three bisulfite-modified DNA samples were assessed through methyl-sensitive high-resolution melting (MS-HRM) analysis. To validate the results, we directly sequenced MS-HRM samples to confirm the presence of CpG-methylated positions. In addition, the RXRα protein levels in extracts of umbilical vein blood were evaluated by western blot. We found differential methylation in a specific locus of the RXRα promoter surrounding the EGR-binding sequence; however, no correlation was found with the level of RXRα protein expression. Variability in the methylation status of the RXRα promoter near the EGR transcription factor binding site in newborn cord blood provides controversial epigenetic insights into RXRα regulation via EGR proteins.

Offspring risk of obesity in childhood, adolescence and adulthood in relation to gestational diabetes mellitus: a sex-specific association

Background

Animal data suggest sexually dimorphic programming of obesity in response to altered intrauterine environment, but the longitudinal impact of gestational diabetes mellitus (GDM) on sex-specific risk of offspring obesity in humans is unclear.

Methods

We conducted a prospective analysis of 15 009 US individuals (7946 female and 7063 male) from the Growing-Up Today Study, who were followed from 1996 (ages 9-14 years) through 2010. Height and weight from validated questionnaires were used to derive body mass index (BMI) at different ages. Obesity during childhood (< 18 years) and adulthood (≥ 18 years) were defined using the International Obesity Task Force and the World Health Organization criteria. GDM exposure was identified through self-reported questionnaires from mothers. Relative risks were estimated using multivariable log-binomial regression models with generalized estimating equations accounting for clustering within the same family.

Results

Male offspring born from pregnancies complicated by GDM had higher BMI compared with non-GDM offspring and had increased risk of obesity; the adjusted relative risk [RR, 95% confidence interval (CI)] was 1.47 (1.11-1.95) for all age groups, 1.59 (1.05-2.41) for late childhood, 1.48 (1.06-2.06) for adolescence and 1.39 (1.00-1.94) for early adulthood. No significant association between obesity and maternal GDM was observed among female participants (RR = 0.97, 95% CI: 0.71-1.33).

Conclusions

The association of GDM with offspring obesity from late childhood through early adulthood may differ by sex; a significant association was observed among male but not female offspring.

A retrospective analysis of a societal experiment among the Danish population suggests that exposure to extra doses of vitamin A during fetal development may lower type 2 diabetes mellitus (T2DM) risk later in life

Vitamin A deficiency has been associated with impaired fetal pancreatic development and increased risk of developing type 2 diabetes mellitus (T2DM). In 1962, mandatory margarine fortification with vitamin A was increased by 25 % in Denmark. We aimed to determine whether offspring of mothers who had been exposed to the extra vitamin A from fortification during pregnancy had a lower risk of developing T2DM in adult life, compared with offspring of mothers exposed to less vitamin A. Individuals from birth cohorts with the higher prenatal vitamin A exposure (born 1 December 1962-31 March 1964) and those with lower prenatal exposure (born 1 September 1959-31 December 1960) were followed up with regard to development of T2DM before 31 December 2012 in the Danish National Diabetes Registry and National Patient Register. Logistic and Cox regression analyses were performed to determine the risk of T2DM by vitamin A exposure level. A total of 193 803 individuals were followed up until midlife. Our results showed that individuals exposed prenatally to extra vitamin A from fortified margarine had a lower risk of developing T2DM than those exposed to lower levels: OR 0·88; 95 % CI 0·81, 0·95, P=0·001, after adjustment for sex. Fetal exposure to small, extra amounts of vitamin A from food fortification may reduce the risk of T2DM. These results may have public health relevance, as they demonstrate that one of the most costly chronic diseases may be prevented by food fortification - a simple and affordable public health nutrition intervention.

Early-Life Nutritional Programming of Type 2 Diabetes: Experimental and Quasi-Experimental Evidence

Consistent evidence from both experimental and human studies suggest that inadequate nutrition in early life can contribute to risk of developing metabolic disorders including type 2 diabetes (T2D) in adult life. In human populations, most findings supporting a causative relationship between early-life malnutrition and subsequent risk of T2D were obtained from quasi-experimental studies (‘natural experiments’). Prenatal and/or early postnatal exposures to famine were demonstrated to be associated with higher risk of T2D in many cohorts around the world. Recent studies have highlighted the importance of epigenetic regulation of gene expression as a possible major contributor to the link between the early-life famine exposure and T2D in adulthood. Findings from these studies suggest that prenatal exposure to the famine may result in induction of persistent epigenetic changes that have adaptive significance in postnatal development but can predispose to metabolic disorders including T2D at the late stages of life. In this review, quasi-experimental data on the developmental programming of T2D are summarized and recent research findings on changes in DNA methylation that mediate these effects are discussed.