Assessing the prediction of type 2 diabetes risk using polygenic and clinical risk scores in South Asian study populations.

Background: Genome-wide polygenic risk scores (PRS) have shown high specificity and sensitivity in predicting type 2 diabetes (T2D) risk in Europeans. However, the PRS-driven information and its clinical significance in non-Europeans are underrepresented. We examined the predictive efficacy and transferability of PRS models using variant information derived from genome-wide studies of Asian Indians (AIs) (PRSAI) and Europeans (PRSEU) using 13,974 AI individuals. Methods: Weighted PRS models were constructed and analyzed on 4602 individuals from the Asian Indian Diabetes Heart Study/Sikh Diabetes Study (AIDHS/SDS) as discovery/training and test/validation datasets. The results were further replicated in 9372 South Asian individuals from UK Biobank (UKBB). We also assessed the performance of each PRS model by combining data of the clinical risk score (CRS). Results: Both genetic models (PRSAI and PRSEU) successfully predicted the T2D risk. However, the PRSAI revealed 13.2% odds ratio (OR) 1.80 [95% confidence interval (CI) 1.63-1.97; p = 1.6 × 10-152] and 12.2% OR 1.38 (95% CI 1.30-1.46; p = 7.1 × 10-237) superior performance in AIDHS/SDS and UKBB validation sets, respectively. Comparing individuals of extreme PRS (ninth decile) with the average PRS (fifth decile), PRSAI showed about two-fold OR 20.73 (95% CI 10.27-41.83; p = 2.7 × 10-17) and 1.4-fold OR 3.19 (95% CI 2.51-4.06; p = 4.8 × 10-21) higher predictability to identify subgroups with higher genetic risk than the PRSEU. Combining PRS and CRS improved the area under the curve from 0.74 to 0.79 in PRSAI and 0.72 to 0.75 in PRSEU. Conclusion: Our data suggest the need for extending genetic and clinical studies in varied ethnic groups to exploit the full clinical potential of PRS as a risk prediction tool in diverse study populations.

Impact of youth onset type 2 diabetes during pregnancy on microvascular and cardiac outcomes.

AIMS: To examine the impact of pregnancy on microvascular and cardiovascular measures in women with youth-onset T2D. METHODS: Microvascular and cardiovascular measures were compared in in a cohort of 116 women who experienced a pregnancy of ≥ 20 weeks gestation and 291 women who did not among women in the Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) study. RESULTS: Cox regression models adjusted for participant characteristics at baseline including age, race/ethnicity, household income, diabetes duration, HbA1c (>6%), and BMI, demonstrated those who experienced pregnancy had 2.76 (1.38-5.49; p = 0.004) fold increased risk of hyperfiltration (eGFR ≥ 135 ml/min/1.73 m2), compared to those without a pregnancy. No differences were observed in rates of retinopathy (48.9% vs. 41.1%) or neuropathy (23.3% vs. 16.3%) in women who experienced pregnancy vs. women who did not, respectively. In fully adjusted models, pregnancy did not impact changes in echocardiographic or arterial stiffness compared to changes in women who were never pregnant. CONCLUSIONS: These results indicate that pregnancy increases the risk of hyperfiltration in women with youth-onset T2D, but not other micro or macrovascular complications. The rates of vascular complications are very high in youth-onset T2D potentially obscuring micro- and macrovascular changes attributable to pregnancy. CLINICAL TRIAL INFORMATION: ClinicalTrials.gov numbers,NCT01364350andNCT02310724.

International Consensus Guideline on Small for Gestational Age: Etiology and Management From Infancy to Early Adulthood.

This International Consensus Guideline was developed by experts in the field of small for gestational age (SGA) of 10 pediatric endocrine societies worldwide. A consensus meeting was held and 1300 articles formed the basis for discussions. All experts voted about the strengths of the recommendations. The guideline gives new and clinically relevant insights into the etiology of short stature after SGA birth, including novel knowledge about (epi)genetic causes. Further, it presents long-term consequences of SGA birth and also reviews new treatment options, including treatment with gonadotropin-releasing hormone agonist (GnRHa) in addition to growth hormone (GH) treatment, as well as the metabolic and cardiovascular health of young adults born SGA after cessation of childhood GH treatment in comparison with appropriate control groups. To diagnose SGA, accurate anthropometry and use of national growth charts are recommended. Follow-up in early life is warranted and neurodevelopment evaluation in those at risk. Excessive postnatal weight gain should be avoided, as this is associated with an unfavorable cardiometabolic health profile in adulthood. Children born SGA with persistent short stature < -2.5 SDS at age 2 years or < -2 SDS at 3 to 4 years of age, should be referred for diagnostic workup. In case of dysmorphic features, major malformations, microcephaly, developmental delay, intellectual disability, and/or signs of skeletal dysplasia, genetic testing should be considered. Treatment with 0.033 to 0.067 mg GH/kg/day is recommended in case of persistent short stature at age of 3 to 4 years. Adding GnRHa treatment could be considered when short adult height is expected at pubertal onset. All young adults born SGA require counseling to adopt a healthy lifestyle.

Maternal Diabetes in Youth-Onset Type 2 Diabetes Is Associated With Progressive Dysglycemia and Risk of Complications.

CONTEXT: Prenatal exposures, including undernutrition, overnutrition, and parental diabetes, are recognized risk factors for future cardiometabolic disease. There are currently no data on effects of parental diabetes on disease progression or complications in youth-onset type 2 diabetes (T2D). OBJECTIVE: We analyzed effects of parental diabetes history on glycemic outcomes, ß-cell function, and complications in a US cohort of youth-onset T2D. METHODS: Participants (N = 699) aged 10 to 17 years with T2D were enrolled at 15 US centers and followed for up to 12 years as part of the TODAY (Treatment Options for type 2 Diabetes in Adolescents and Youth) and TODAY2 follow-up studies. Information about diabetes diagnosis in biological mothers was available for 621 participants (never = 301; before or during pregnancy = 218; after pregnancy = 102) and in biological fathers for 519 (no diabetes = 352; paternal diabetes = 167). RESULTS: Maternal, but not paternal, diabetes was associated with loss of glycemic control over time, defined as glycated hemoglobin A1c greater than or equal to 8% for more than 6 months (P = .001). Similarly, maternal, but not paternal, diabetes was associated with increased risk of glomerular hyperfiltration (P = .01) and low heart rate variability (P = .006) after 12 years of follow-up. Effects were largely independent of age, sex, race/ethnicity, and household income. Maternal diabetes during vs after pregnancy had similar effects on outcomes. CONCLUSION: Maternal diabetes, regardless of whether diagnosed during vs after pregnancy, is associated with worse glycemic control, glomerular hyperfiltration, and reduced heart rate variability in youth with T2D in TODAY. The strong associations of diabetes outcomes with maternal diabetes suggest a possible role for in utero programming.

miR-130b/301b Is a Negative Regulator of Beige Adipogenesis and Energy Metabolism In Vitro and In Vivo.

Thermogenic brown or beige adipocytes dissipate energy in the form of heat and thereby counteract obesity and related metabolic complications. The miRNA cluster miR-130b/301b is highly expressed in adipose tissues and has been implicated in metabolic diseases as a posttranscriptional regulator of mitochondrial biogenesis and lipid metabolism. We investigated the roles of miR-130b/301b in regulating beige adipogenesis in vivo and in vitro. miR-130b/301b declined in adipose progenitor cells during beige adipogenesis, while forced overexpression of miR-130b-3p or miR-301b-3p suppressed uncoupling protein 1 (UCP1) and mitochondrial respiration, suggesting that a decline in miR-130b-3p or miR-301b-3p is required for adipocyte precursors to develop the beige phenotype. Mechanistically, miR-130b/301b directly targeted AMP-activated protein kinase (AMPKα1) and suppressed peroxisome proliferator-activated receptor γ coactivator-1α (Pgc-1α), key regulators of brown adipogenesis and mitochondrial biogenesis. Mice lacking the miR-130b/301b miRNA cluster showed reduced visceral adiposity and less weight gain. miR-130b/301b null mice exhibited improved glucose tolerance, increased UCP1 and AMPK activation in subcutaneous fat (inguinal white adipose tissue [iWAT]), and increased response to cold-induced energy expenditure. Together, these data identify the miR-130b/301b cluster as a new regulator that suppresses beige adipogenesis involving PGC-1α and AMPK signaling in iWAT and is therefore a potential therapeutic target against obesity and related metabolic disorders.

Bone Mass Accrual in First Six Months of Life: Impact of Maternal Diabetes, Infant Adiposity, and Cord Blood Adipokines.

The perinatal period is a time of substantial bone mass accrual with many factors affecting long-term bone mineralization. Currently it is unclear what effect maternal gestational/type 2 diabetes has on infant bone mass accrual. This is a prospective study of offspring of Native American and Hispanic mothers with normoglycemia (n = 94) and gestational diabetes or type 2 diabetes (n = 64). Infant anthropometrics were measured at birth, 1, and 6 months of age. Cord blood leptin, high-molecular weight adiponectin (HMWA), pigment epithelium-derived factor (PEDF), vascular epithelium growth factor (VEGF), endoglin, and C-peptide were measured by ELISA. Infants had bone mineral density measurement at 1 month or/and 6 months of age using dual-energy x-ray absorptiometry scan. Mothers with diabetes were older (31 ± 6 years vs 25 ± 4 years) and had higher pre-pregnancy BMI (32.6 ± 5.8 vs 27.2 ± 6.4 kg/m2) than control mothers. Mean HbA1C of mothers with diabetes was 5.9 ± 1.0% compared to 5.1 ± 0.3% in controls early in pregnancy. Infants born to mothers with diabetes (DM-O) were born at a slightly lower gestational age compared to infants born to control mothers (Con-O). There was no difference in total body less head bone mineral content (BMC) or bone mineral density (BMD) between DM-O and Con-O. For both groups together, bone area, BMD, and BMC tracked over the first 6 months of life (r: 0.56, 0.38, and 0.48, respectively). Percent fat was strongly and positively correlated with BMC at 1 month of age (r = 0.44; p < 0.001) and BMC at both 1 and 6 months of age correlated strongly with birth weight. There were no associations between infant bone mass and cord blood leptin, PEDF, or VEGF, while C-peptide had a significant correlation with BMC at 1 and 6 months only in DM-O (p = 0.01 and 0.03, respectively). Infants born to mothers with well-controlled gestational/type 2 diabetes have normal bone mass accrual. Bone mineral content during this time is highly correlated with indices of infant growth and the association of bone mineral indices with percent body fat suggests that bone-fat crosstalk is operative early in life.

Human Milk Exosomal MicroRNA: Associations with Maternal Overweight/Obesity and Infant Body Composition at 1 Month of Life.

Among all the body fluids, breast milk is one of the richest sources of microRNAs (miRNAs). MiRNAs packaged within the milk exosomes are bioavailable to breastfeeding infants. The role of miRNAs in determining infant growth and the impact of maternal overweight/obesity on human milk (HM) miRNAs is poorly understood. The objectives of this study were to examine the impact of maternal overweight/obesity on select miRNAs (miR-148a, miR-30b, miR-29a, miR-29b, miR-let-7a and miR-32) involved in adipogenesis and glucose metabolism and to examine the relationship of these miRNAs with measures of infant body composition in the first 6 months of life. Milk samples were collected from a cohort of 60 mothers (30 normal-weight [NW] and 30 overweight [OW]/obese [OB]) at 1-month and a subset of 48 of these at 3 months of lactation. Relative abundance of miRNA was determined using real-time PCR. The associations between the miRNAs of interest and infant weight and body composition at one, three, and six months were examined after adjusting for infant gestational age, birth weight, and sex. The abundance of miR-148a and miR-30b was lower by 30% and 42%, respectively, in the OW/OB group than in the NW group at 1 month. miR-148a was negatively associated with infant weight, fat mass, and fat free mass, while miR-30b was positively associated with infant weight, percent body fat, and fat mass at 1 month. Maternal obesity is negatively associated with the content of select miRNAs in human milk. An association of specific miRNAs with infant body composition was observed during the first month of life, suggesting a potential role in the infant's adaptation to enteral nutrition.

The First Genome-Wide Association Study for Type 2 Diabetes in Youth: The Progress in Diabetes Genetics in Youth (ProDiGY) Consortium.

The prevalence of type 2 diabetes in youth has increased substantially, yet the genetic underpinnings remain largely unexplored. To identify genetic variants predisposing to youth-onset type 2 diabetes, we formed ProDiGY, a multiethnic collaboration of three studies (TODAY, SEARCH, and T2D-GENES) with 3,006 youth case subjects with type 2 diabetes (mean age 15.1 ± 2.9 years) and 6,061 diabetes-free adult control subjects (mean age 54.2 ± 12.4 years). After stratifying by principal component-clustered ethnicity, we performed association analyses on ∼10 million imputed variants using a generalized linear mixed model incorporating a genetic relationship matrix to account for population structure and adjusting for sex. We identified seven genome-wide significant loci, including the novel locus rs10992863 in PHF2 (P = 3.2 × 10-8; odds ratio [OR] = 1.23). Known loci identified in our analysis include rs7903146 in TCF7L2 (P = 8.0 × 10-20; OR 1.58), rs72982988 near MC4R (P = 4.4 × 10-14; OR 1.53), rs200893788 in CDC123 (P = 1.1 × 10-12; OR 1.32), rs2237892 in KCNQ1 (P = 4.8 × 10-11; OR 1.59), rs937589119 in IGF2BP2 (P = 3.1 × 10-9; OR 1.34), and rs113748381 in SLC16A11 (P = 4.1 × 10-8; OR 1.04). Secondary analysis with 856 diabetes-free youth control subjects uncovered an additional locus in CPEB2 (P = 3.2 × 10-8; OR 2.1) and consistent direction of effect for diabetes risk. In conclusion, we identified both known and novel loci in the first genome-wide association study of youth-onset type 2 diabetes.

Maternal diabetes alters microRNA expression in fetal exosomes, human umbilical vein endothelial cells and placenta.

BACKGROUND: Exposure to diabetes in utero influences future metabolic health of the offspring. MicroRNAs (miRNA) are small noncoding RNAs that may contribute mechanistically to the effects on offspring imparted by diabetes mellitus (DM) during pregnancy. We hypothesized that exposure to DM during pregnancy influences select miRNAs in fetal circulation, in human umbilical vein endothelial cells (HUVEC), and placenta. METHODS: miRNA abundance was quantified using real-time PCR from RNA isolated from umbilical cord serum exosomes, HUVEC, and placenta exposed to diabetes or normoglycemia during pregnancy. The abundance of each of these miRNAs was determined by comparison to a known standard and the relative expression assessed using the 2-ΔΔCt method. Multivariable regression models examined the associations between exposure to diabetes during pregnancy and miRNA expression. RESULTS: miR-126-3p was highly abundant in fetal circulation, HUVEC, and placenta. Diabetes exposure during pregnancy resulted in lower expression of miR-148a-3p and miR-29a-3p in the HUVEC. In the placenta, for miR-126-3p, there was a differential effect of DM by birth weight between DM versus control group, expression being lower at the lower birth weight, however not different at the higher birth weight. CONCLUSION: Exposure to DM during pregnancy alters miRNA expression in the offspring in a tissue-specific manner. IMPACT: miRNAs are differentially expressed in fetal tissues from offspring exposed to in utero diabetes mellitus compared to those who were not exposed. miRNA expression differs among tissue types (human umbilical vein endothelial cells, placenta and circulation exosomes) and response to diabetes exposure varies according to tissue of origin. miRNA expression is also affected by maternal and infant characteristics such as infant birth weight, infant sex, maternal age, and maternal BMI. miRNAs might be one of the potential mechanisms by which offspring's future metabolic status may be influenced by maternal diabetes mellitus.

Fetal circulating human resistin increases in diabetes during pregnancy and impairs placental mitochondrial biogenesis.

BACKGROUND: Diabetes during pregnancy affects placental mitochondrial content and function, which has the potential to impact fetal development and the long-term health of offspring. Resistin is a peptide hormone originally discovered in mice as an adipocyte-derived factor that induced insulin resistance. In humans, resistin is primarily secreted by monocytes or macrophages. The regulation and roles of human resistin in diabetes during pregnancy remain unclear. METHODS: Fetal resistin levels were measured in cord blood from pregnancies with (n = 42) and without maternal diabetes (n = 81). Secretion of resistin from cord blood mononuclear cells (CBMCs) was measured. The actions of human resistin in mitochondrial biogenesis were determined in placental trophoblastic cells (BeWo cells) or human placental explant. RESULTS: Concentrations of human resistin in cord sera were higher in diabetic pregnancies (67 ng/ml) compared to healthy controls (50 ng/ml, P < 0.05), and correlated (r = 0.4, P = 0.002) with a measure of maternal glycemia (glucose concentration 2 h post challenge). Resistin mRNA was most abundant in cord blood mononuclear cells (CBMCs) compared with placenta and mesenchymal stem cells (MSCs). Secretion of resistin from cultured CBMCs was increased in response to high glucose (25 mM). Exposing BeWo cells or human placental explant to resistin decreased expression of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), mitochondrial abundance, and ATP production. CONCLUSIONS: Resistin is increased in fetal circulation of infants exposed to the diabetic milieu, potentially reflecting a response of monocytes/macrophages to hyperglycemia and metabolic stresses associated with diabetes during pregnancy. Increased exposure to resistin may contribute to mitochondrial dysfunction and aberrant energy metabolism characteristic of offspring exposed to diabetes in utero.

Role of metformin in epigenetic regulation of placental mitochondrial biogenesis in maternal diabetes.

Adverse maternal environments, such as diabetes and obesity, impair placental mitochondrial function, which affects fetal development and offspring long-term health. The underlying mechanisms and effective interventions to abrogate such effect remain unclear. Our previous studies demonstrated impaired mitochondrial biogenesis in male human placenta of diabetic mothers. In the present studies, epigenetic marks possibly related to mitochondrial biogenesis in placentae of women with diabetes (n = 23) and controls (n = 23) were analyzed. Effects of metformin were examined in human placental explants from a subgroup of diabetic women and in a mouse model of maternal high fat diet feeding. We found that maternal diabetes was associated with epigenetic regulation of mitochondrial biogenesis in human placenta in a fetal sex-dependent manner, including decreased histone acetylation (H3K27 acetylation) and increased promoter methylation of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α). In male placenta, the levels of H3K27 acetylation and PGC-1α promoter methylation correlated significantly with the activity of AMP-activated protein kinase (AMPK). Metformin treatment on male diabetic placental explant activated AMPK and stimulated PGC-1α expression, concomitant with increased H3K27 acetylation and decreased PGC-1α promoter methylation. In vivo, we show that maternal metformin treatment along with maternal high fat diet significantly increased mouse placental abundance of PGC-1α expression and downstream mitochondrial transcription factor A (TFAM) and inhibited maternal high fat diet-impaired placental efficiency and glucose tolerance in offspring. Together, these findings suggest the capability of metformin to stimulate placental mitochondrial biogenesis and inhibit the aberrant epigenetic alterations occurring in maternal diabetes during pregnancy, conferring protective effects on offspring.

Beta cell function and insulin sensitivity in obese youth with maturity onset diabetes of youth mutations vs type 2 diabetes in TODAY: Longitudinal observations and glycemic failure.

OBJECTIVE: In treatment options for type 2 diabetes in adolescents and youth (TODAY), 4.5% of obese youth clinically diagnosed with type 2 diabetes (T2D) had genetic variants consistent with maturity onset diabetes of youth (MODY) diagnosis. The course of IS and ß-cell function in obese youth with MODY remains unknown. In this secondary analysis, we examined IS and ß-cell function in MODY vs. non-MODY obese youth at randomization and over time. METHODS: Genetic data in TODAY included 426 non-MODY (T2D) and 22 MODY youth (7 glucokinase MODY mutation positive [GCK-MODY], 12 hepatocyte nuclear factor MODY mutation positive [HNF-MODY], 2 Insulin gene mutation [insulin (INS)-MODY], and 1 Kruppel-like factor 11 [KLF11-MODY]). Oral glucose tolerance test (OGTT)-derived IS, C-peptide index, and ß-cell function relative to IS oral disposition index (oDI) was measured at randomization, and over 24 months in addition to total and high-molecular-weight adiponectin (HMWA). RESULTS: At randomization, IS, total adiponectin, and HMWA were significantly higher in the two MODY groups than in non-MODY. ß-cell function measured by C-peptide oDI was 3-fold higher in GCK-MODY than in HNF-MODY and 1.5-fold higher than non-MODY (P for both <.05). Glycemic failure rate was 75.0% in HNF-MODY, 46.9% in non-MODY, and zero in GCK-MODY youth. While the changes in IS and oDI were not different among the three groups in the first 6 months, IS improved from 6 to 24 months in HNF-MODY vs GCK-MODY youth. CONCLUSIONS: In TODAY, ß-cell function at randomization was worse in obese HNF-MODY youth compared with GCK-MODY youth, while insulin sensitivity was worse in non-MODY compared with the other two MODY groups. Over time, IS showed the greatest improvement in HNF-MODY youth. This raises the possibility that TODAY therapeutic modalities of insulin sensitization in these obese HNF-MODY youth may have played a beneficial role.

Macrophage-Derived microRNA-155 Increases in Obesity and Influences Adipocyte Metabolism by Targeting Peroxisome Proliferator-Activated Receptor Gamma.

OBJECTIVE: This study aimed to investigate cellular sources of microRNAs (miRNA) within adipose tissue and the impact of obesity on miRNA expression, as well as to examine targets of miRNAs. METHODS: miRNA expression by quantitative polymerase chain reaction was examined in adipocytes, adipose tissue macrophages (ATM), and peripheral blood mononuclear cells from and individuals with normal weight and with obesity. Differentiated 3T3-L1 adipocytes were cocultured with macrophages, and 3T3-L1 and differentiated human mesenchymal stem cells were transfected with miR-155, with peroxisome proliferator-activated receptor gamma (PPAR-γ) and solute carrier family 2 member 4 (GLUT4) abundance measured via Western blot analysis. RESULTS: Abundance of miR-155 and miR-210 was increased in ATM of participants with obesity by 6.7-fold and 2.9-fold (P = 0.002 and P = 0.013, respectively). miR-130b expression was increased 1.8-fold in ATM and 4.3-fold in adipocytes from participants with obesity (P = 0.007 and P = 0.02, respectively). PPARG mRNA expression decreased 32% (P = 0.044) in adipocytes from individuals with obesity. In 3T3-L1 cells exposed to macrophages, PPARG expression decreased 99.4% (P = 0.02). PPAR-γ protein content declined 75% (P = 0.001) in 3T3-L1 cells transfected with miR-155. GLUT4 protein levels were reduced by 55% (P = 0.021) in differentiated human mesenchymal stem cells exposed to miR-155. CONCLUSIONS: Adipose tissue miRNAs are influenced in a cell type-specific fashion by obesity, with macrophage miR-155 potentially impacting neighboring adipocytes.

A genetic approach to evaluation of short stature of undetermined cause.

Short stature is a common presentation to paediatric endocrinologists. After exclusion of major endocrine or systemic disease, most children with short stature are diagnosed based on a description of their growth pattern and the height of their parents (eg, familial short stature). Height is a polygenic trait and genome-wide association studies have identified many of the associated genetic loci. Here we review the application of genetic studies, including copy number variant analysis, targeted gene panels, and whole-exome sequencing in children with idiopathic short stature. We estimate 25-40% of children diagnosed with idiopathic short stature could receive a molecular diagnosis using these technologies. A molecular diagnosis for short stature is important for affected individuals and their families and might inform treatment decisions surrounding use of growth hormone or insulin-like growth factor 1 therapy.

Offspring sex impacts DNA methylation and gene expression in placentae from women with diabetes during pregnancy.

AIMS/HYPOTHESIS: We hypothesized that diabetes during pregnancy (DDP) alters genome-wide DNA methylation in placenta resulting in differentially methylated loci of metabolically relevant genes and downstream changes in RNA and protein expression. METHODS: We mapped genome-wide DNA methylation with the Infinium 450K Human Methylation Bead Chip in term fetal placentae from Native American and Hispanic women with DDP using a nested case-control design (n = 17 pairs). RNA expression and protein levels were assayed via RNA-Seq and Western Blot. RESULTS: Genome-wide DNA methylation analysis revealed 465 CpG sites with significant changes for male offspring, 247 for female offspring, and 277 for offspring of both sexes (p<0.001). Placentae from female offspring were 40% more likely to have significant gains in DNA methylation compared with placentae from male offspring exposed to DDP (p<0.001). Changes in DNA methylation corresponded to changes in RNA and protein levels for 6 genes: PIWIL3, CYBA, GSTM1, GSTM5, KCNE1 and NXN. Differential DNA methylation was detected at loci related to mitochondrial function, DNA repair, inflammation, oxidative stress. CONCLUSIONS/INTERPRETATION: These findings begin to explain mechanisms responsible for the increased risk for obesity and type 2 diabetes in offspring of mothers with DDP.

Effects of maternal diabetes and fetal sex on human placenta mitochondrial biogenesis.

Abnormal placental function in maternal diabetes affects fetal health and can predispose offspring to metabolic diseases in later life. There are fetal sex-specific differences in placenta structure and gene expression, which may affect placental responses to maternal diabetes. The present study examined the effects of maternal diabetes on indices of mitochondrial biogenesis in placentae from male and female offspring. Mitochondrial DNA (mtDNA) copy number and expression of key regulators of mitochondrial biogenesis were assessed in placentae from 19 diabetic and 23 non-diabetic women. The abundance of peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) and mitochondria transcription factor A (TFAM) were lower in female placentae compared to males, but not mtDNA content. In male offspring, maternal diabetes was associated with decreased placental PGC-1α and TFAM, and mitochondrial DNA (mtDNA) content. Male placental TFAM levels were highly correlated with PGC-1α and mtDNA content. However, despite decreased PGC-1α, concomitant changes in TFAM and mtDNA content by diabetes were not observed in females. In addition, TFAM abundance in female placentae was not correlated with PGC-1α or mtDNA content. In summary, placental PGC-1α/TFAM/mitochondrial biogenesis pathway is affected by maternal diabetes and offspring sex. Decreased PGC-1α in response to maternal diabetes plausibly contributes to impaired mitochondrial biogenesis in placentae of male offspring, which may affect long-term health and explain some of enhanced risk of future metabolic diseases in males.