Nutrient Composition of Donor Human Milk and Comparisons to Preterm Human Milk.

BACKGROUND: Human milk is the preferred diet for very low birth weight (VLBW, <1500 g) infants. When mother's own milk is unable to meet the needs of VLBW infants, donor human milk (DHM) is the preferred alternative. Unfortunately, the composition of DHM remains elusive and no comparative studies between preterm human milk and DHM have been performed previously. OBJECTIVES: We aimed to analyze the nutrient content of commercial pooled DHM and compare nutrient content in DHM with that of early and mature preterm human milk. METHODS: We analyzed nutrient content in 15 DHM samples provided from 7 commercial milk banks including calories, carbohydrate, fat, protein, sodium, chloride, potassium, zinc, calcium, phosphorus, magnesium, and vitamin D and compared each nutrient to early (7 d of life) and mature (28 d of life) preterm human milk samples (n = 28-36 per nutrient, gestational age = 28 ± 3 wk). Protein-to-energy ratio and carbohydrate-to-nonprotein energy ratio were calculated for each sample and compared. RESULTS: Mean values for all macro- and micronutrients in DHM are reported. In comparison to early or mature preterm human milk, DHM had significantly lower protein, sodium, chloride, potassium, and zinc content. Calorie, carbohydrate, calcium, phosphorus, magnesium, and vitamin D content did not differ statistically between DHM and early or mature preterm human milk. Fat content was modestly lower in early but not mature human milk when compared with DHM. CONCLUSIONS: We provide mean values for several macro- and micronutrients for DHM and identify key differences between DHM and preterm human milk, which may be considered when designing human milk-based feeding plans. This study was registered at clinicaltrials.gov as NCT05742815.

Routine Diaper Change Alters Kidney Oxygenation in Premature Infants: A Non-A Priori Analysis.

BACKGROUND: Reduction in oxygen delivery to developing kidneys of premature infants may be an important source for acute kidney injury in premature infants. PURPOSE: To describe changes in continuous kidney oxygenation (RrSO 2 ) measures before, during, and after routine diaper changes. METHODS: Non-a priori analysis of a prospective cohort that received continuous measurement of RrSO 2 with near-infrared spectroscopy (NIRS) over the first 14 days of life demonstrating acute RrSO 2 drops surrounding diaper changes. RESULTS: In total, 26 of 38 (68%) infants (≤1800 g) from our cohort exhibited acute drops in RrSO 2 that temporally correlated with diaper changes. Mean (SD) RrSO 2 baseline prior to each diaper change event was 71.1 (13.2), dropped to 59.3 (11.6) during diaper change, and recovered to 73.3 (13.2). There was a significant difference between means when comparing baseline to diaper change ( P < .001; 95% CI, 9.9 to 13.8) and diaper change to recovery ( P < .001; 95% CI, -16.9 to -11.2). The mean decrease in RrSO 2 during diaper change averaged 12 points (17%) below 15-minute RrSO 2 mean prior to diaper change, with quick recovery to prediaper change levels. No decreases in SpO 2 , blood pressure, or heart rate were documented during the intermittent kidney hypoxic events. IMPLICATIONS FOR PRACTICE AND RESEARCH: Routine diaper changes in preterm infants may increase the risk for acute reductions in RrSO 2 as measured by NIRS; however, the impact on kidney health remains unknown. Larger prospective cohort studies assessing kidney function and outcomes related to this phenomenon are needed.

Red blood cell volume, but not platelet or plasma volume is associated with mortality in neonatal ECMO.

BACKGROUND: Blood product transfusions are necessary for critically ill neonates on extracorporeal membrane oxygenation (ECMO). Transfusions are administered in response to unstudied arbitrary thresholds and may be associated with adverse outcomes. The objective of this study was to identify relationships between blood product components and mortality in neonates receiving ECMO support for respiratory indications. STUDY DESIGN AND METHODS: A retrospective review of neonates receiving ECMO for respiratory indications from 2002 to 2019 from a single quaternary-referral neonatal intensive care unit (NICU). Demographic and outcome data and transfusion volume (ml/kg/day) were harvested from the medical record, and baseline mortality risk was assessed using NEO-RESCUERS scores. The association between volume of red blood cells (RBC), platelet, plasma transfusion rates (ml/kg/day), and mortality on ECMO were assessed after adjustment for NEO-RESCUERS score. Cox proportional hazards (CPH) competing risk model was used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for each variable and mortality outcome. MEASUREMENTS AND MAIN RESULTS: Among 248 neonates undergoing ECMO for respiratory failure, overall survival was 93%. RBC, platelet, and plasma volume were highly associated with mortality during ECMO in an unadjusted model. After adjusting for NEO-RESCUERS score, RBC volume was associated with increased mortality risk (HR 1.013, 95% CI 1.004-1.022, p = .0043), but platelet and plasma volume were not associated with mortality. CONCLUSIONS: RBC, but not platelet or plasma volume, is associated with mortality in neonates on ECMO. Our findings refute previous studies demonstrating an association between platelet volume and mortality for neonates on ECMO.

Sleep SAAF responsive parenting intervention improves mothers' feeding practices: a randomized controlled trial among African American mother-infant dyads.

BACKGROUND/OBJECTIVE: Parents shape children's early experiences with food, influencing what is served, children's food choices, and how much children eat. Responsive parenting (RP) interventions such as INSIGHT have improved maternal infant feeding practices, but have only been tested among predominantly White families. This secondary analysis of data from the Sleep SAAF (Strong African American Families) RCT tests the effects of an RP intervention designed to prevent rapid infant weight gain on African American mothers' infant feeding practices. METHODS: Primiparous African American mother-infant dyads (n = 194) were randomized to an RP or safety control intervention delivered by community research associates at infant age 3 and 8 weeks. At 16 weeks, mothers completed the Babies Need Feeding questionnaire, the Infant Feeding Styles Questionnaire, and the Babies Need Soothing questionnaire. Logistic regression and general linear models examined the effect of study group on infant feeding practices. Moderation analyses explored whether effects varied by feeding mode (any breast milk versus exclusive formula), maternal age (≥ 20 years versus < 20 years), and maternal pre-pregnancy BMI (with obesity versus not). RESULTS: RP mothers reported more responsive feeding (p = 0.005, partial η2 = 0.02), lower likelihood of using beverages other than breast milk/formula to soothe their infant (p = 0.01, OR = 0.42, 95% CI [0.2-0.8]), and less pressure with cereal than control mothers (p = 0.09, partial η2 = 0.02). RP mothers also reported less pressure to finish/soothe than controls (p = 0.007, partial η2 = 0.04); feeding mode (B = 0.74, p = 0.003) and maternal age (B = 0.53, p = 0.04) moderated this effect. There were no significant group differences in bottle-feeding practices (e.g., adding cereal to bottle, using an appropriate nipple/bottle size), or in context-based or emotion-based food to soothe. CONCLUSIONS: Responsive parenting education influenced some feeding practices of African American mothers. Mothers reported using less pressure, a control-based feeding practice, and more responsive feeding than controls. TRIAL REGISTRATION: Sleep SAAF: A Strong African American Families Study. www. CLINICALTRIALS: gov NCT03505203. Registered 3 April 2018.

Effects of the Sleep SAAF responsive parenting intervention on rapid infant weight gain: A randomized clinical trial of African American families.

Responsive parenting (RP) interventions reduce rapid infant weight gain but their effect for underserved populations is largely unknown. The Sleep SAAF (Strong African American Families) study is a two-arm randomized clinical trial for primiparous African American mother-infant dyads that compares an RP intervention to a child safety control over the first 16 weeks postpartum. Here we report on intervention effects on rapid infant weight gain and study implementation. Families were recruited from a mother/baby nursery shortly after delivery. Community Research Associates (CRAs) conducted intervention home visits at 3 and 8 weeks postpartum, and data collection home visits at 1, 8, and 16 weeks postpartum. To examine rapid infant weight gain, conditional weight gain (CWG) from 3 to 16 weeks, the primary outcome, and upward crossing of 2 major weight-for-age percentile lines were calculated. Among the 212 mother-infant dyads randomized, 194 completed the trial (92% retention). Randomized mothers averaged 22.7 years, 10% were married, and 49% participated in the Supplemental Nutrition Assistance Program (SNAP). Adjusting for covariates, mean CWG was lower among RP infants (0.04, 95% CI [-0.33, 0.40]) than among control infants (0.28, 95% CI [-0.08, 0.64]), reflecting non-significantly slower weight gain (p = 0.15, effect size d = 0.24). RP infants were nearly half as likely to experience upward crossing of 2 major weight-for-age percentile lines (14.1%) compared to control infants (24.2%), p = 0.09, odds ratio = 0.52 (95% CI [0.24, 1.12]). Implementation data revealed that participating families were engaged in the intervention visits and intervention facilitators demonstrated high fidelity to intervention materials. Findings show that RP interventions can be successfully implemented among African American families while suggesting the need for modifications to yield stronger effects on infant weight outcomes.

Renal Oxygenation (rSO 2 ) Population Parameter Estimates in Premature Infants Routinely Monitored With Near-Infrared Spectroscopy.

BACKGROUND: Currently, reference ranges for renal oxygenation measured by near-infrared spectroscopy (NIRS) in preterm infants beyond the first days of life are lacking, especially those born prior to 29 weeks' gestation. Population estimates of renal oxygenation (rSO 2 ) levels among preterm infants over time have yet to be established, leading to reluctance in clinical application. PURPOSE: To characterize the distribution and estimate population parameters for renal oxygenation measured by NIRS during the first 14 days of life among preterm infants. METHODS: We prospectively observed rSO 2 trends of 37 infants before 34 weeks' gestation and 1800-g or less birth weight for the first 14 days of life. Analyses included distribution fit tests, ordinary least squares (OLS) regression, and t tests. RESULTS: Average daily rSO 2 variation steadily increased with 42% difference through the first 14 days of life. For all infants, renal rSO 2 means peaked during the first 3 days of life and plateaued around 7 days. Daily rSO 2 slopes were significantly lower among males and infants 29 weeks' or less gestation. IMPLICATIONS FOR PRACTICE: Renal rSO 2 during the first 14 days of life reflects normal extrauterine transition reaching stabilization around 7 days of life. Gestational age, birth weight, and gender may predict the early trajectory of rSO 2 patterns. Population estimates provide parameters for renal rSO 2 that may indicate early-onset tissue hypoxia when acute or significant drops from baseline occur. IMPLICATIONS FOR RESEARCH: We present a framework to guide future research using renal NIRS technology in preterm infants to determine deviations from expected trends that may precede renal injury.

Vitamin K and ECMO for neonatal hypoxic respiratory failure.

INTRODUCTION: The objectives of this retrospective cohort study were to examine the effect of vitamin K administration on hemorrhagic and thrombotic complications, blood product utilization, and outcomes in neonatal extracorporeal membrane oxygenation (ECMO). METHODS: In the pilot study, complications, blood product use, and outcome data for neonates who received (n = 21) or did not receive (n = 18) a single dose of vitamin K (5 mg) immediately after initiation of ECMO for respiratory failure between 2006 and 2010 were compared. In the validation cohort, complications and outcomes were compared for 74 consecutive neonates supported with ECMO for respiratory failure who received (n = 45) or did not receive (n = 29) additional vitamin K once daily for prothrombin time (PT) ⩾14 seconds during ECMO from 2014 to 2019. RESULTS: In the pilot study, vitamin K at ECMO initiation was associated with fewer thrombotic complications and similar hemorrhagic complications. The volume of fresh frozen plasma was higher in neonates who received vitamin K, but total blood product and other component volume did not differ between groups. ECMO run time, survival off ECMO, survival to discharge, and length of stay did not differ between cohorts. In the validation cohort, neonates who received additional vitamin K during ECMO had longer ECMO run time and length of stay, but no difference in mortality was observed. Further, thrombotic and hemorrhagic complications as well as blood product exposure were similar between cohorts. CONCLUSIONS: These data suggest that routine vitamin K administration may have limited or no benefit during neonatal ECMO.

Estimating Length of Stay for Simple Gastroschisis.

BACKGROUND: Length of stay (LOS) is an important measure of quality; however, estimating LOS for rare populations such as gastroschisis is problematic. Our objective was to identify explanatory variables for LOS and build a model to estimate LOS in neonates with simple gastroschisis. METHODS: In 73 neonates with simple gastroschisis (47% female, 67% White), statistical correlations for 31 potential explanatory variables for LOS were evaluated using multivariate linear regression. Poisson regression was used to estimate LOS in predetermined subpopulations, and a life table model was developed to estimate LOS for simple gastroschisis. RESULTS: Female sex (-2.4 d), "time to silo placement" (0.9 d), total parenteral nutrition days (0.6 d), need for any nasogastric feedings (11.4 d) and at discharge (-7 d), "feeding tolerance" (0.4 d), days to first postoperative stool (-0.3 d), and human milk exposure (-3.4 d) associated with LOS in simple gastroschisis. Estimated LOS for preterm neonates was longer than term infants (5.4 versus 4.6 wk) but similar for estimates based on sex and race. Based on these associations, we estimate that >50% of neonates with simple gastroschisis will be discharged by hospital day 35. CONCLUSIONS: We identified several associations that explained variations in LOS and developed a novel model to estimate LOS in simple gastroschisis, which may be applied to other rare populations.

Evaluating definitions for maternal fever as diagnostic criteria for intraamniotic infection in low-risk pregnancies.

BACKGROUND: Conflicting statements by stakeholders in obstetric care have suggested different criteria for defining peripartum fever and suspected intraamniotic infection, which have not been evaluated. METHODS: A case-control study of pregnancies between 35 and 41 weeks at a single tertiary care center between January 2016 and December 2017. Cases with pathology-confirmed chorioamnionitis were identified, and demographic data, risk factors, and neonatal outcomes were extracted from the medical record. The American College of Gynecology (ACOG) and National Institutes of Health (NIH) Workshop guidelines for identifying isolated maternal fever and suspected intraamniotic infection were applied, retrospectively. Odds ratios, sensitivity/specificity, and predictive value of each guideline for pathology-confirmed chorioamnionitis and for secondary outcomes of interest were determined. RESULTS: 943 mother-infant dyads were evaluated including 41 (4.3%) with pathology-confirmed chorioamnionitis. Among cases, 18 (43.9%) experienced any maternal temperature ≥38°C (100.4°F) with 12 (29.2%) and 8 (19.5%) cases meeting criteria for isolated maternal fever according to the ACOG and Workshop guidelines, respectively. Furthermore, the ACOG and Workshop guidelines correctly identified 6 (14.6%) and 3 (7.3%) of cases of pathology-confirmed chorioamnionitis with high agreement between definitions (κ = 0.63). Laboratory evaluation, antimicrobial exposure, and prolonged length of stay in offspring are substantially higher in cases as compared to controls. CONCLUSIONS: Guidelines that rely on maternal fever definitions for the diagnosis of suspected intraamniotic infection exhibit high agreement with low sensitivity, but high specificity and negative predictive value for pathology-confirmed chorioamnionitis. Maternal temperature ≥38°C continues to drive clinical decision-making for both mother and offspring.

Blood product transfusion and mortality in neonatal extracorporeal membrane oxygenation.

BACKGROUND: Neonates receiving extracorporeal membrane oxygenation (ECMO) support are transfused large volumes of red blood cells (RBCs) and platelets (PLTs). Transfusions are often administered in response to specific, but largely unstudied thresholds. The aim of this study is to examine the relationship between RBC and PLT transfusion rates and mortality in neonates receiving ECMO support. STUDY DESIGN AND METHODS: We retrospectively examined outcomes of neonates receiving ECMO support in the neonatal intensive care unit (NICU) for respiratory failure between 2010 and 2016 at a single quaternary-referral NICU. We examined the association between RBC and PLT transfusion rate (mL per kg per day) and in-hospital mortality, adjusting for confounding by using a validated composite baseline risk score (Neo-RESCUERS). RESULTS: Among the 110 neonates receiving ECMO support, in-hospital mortality was 28%. The median RBC transfusion rate (mL/kg/d) after cannulation was greater among non-survivors, compared to survivors: 12.4 (IQR 9.3-16.2) versus 7.3 (IQR 5.1-10.3), p < 0.001. Similarly, PLT transfusion rate was greater among non-survivors: 22.9 (9.3-16.2) versus 12.1 (8.4-20.1), p = 0.02. After adjusting for baseline mortality risk, both RBC transfusion (adjusted relative risk per 5 mL/kg/d increase: 1.33; 95% CI 1.05-1.69, p = 0.02) and PLT transfusion (adjusted relative risk per 5 mL/kg/d increase: 1.12; 95% CI 1.02-1.23, p = 0.02) were both associated with in-hospital mortality. CONCLUSIONS: RBC and PLT transfusion rates are associated with in-hospital mortality among neonates receiving ECMO. These data provide a basis for future studies evaluating more restrictive transfusion practices for neonates receiving ECMO support.

The utility of cranial ultrasound as a screening tool for neonatal ECMO.

Background Neurologic complications including hemorrhage, ischemia, and infarction are often identified in neonates undergoing extracorporeal membrane oxygenation (ECMO) and may contribute to the high morbidity observed in ECMO survivors. Screening for intracranial complications is reliant on bedside transcranial ultrasound (CUS) prior to and during ECMO therapy, and advanced imaging [i.e. computed tomography (CT)/magnetic resonance imaging (MRI)] is recommended after completion of ECMO support. The goal of this study is to describe the correlation of intracranial complications identified on CUS during ECMO and MRI after completion of ECMO. Methods Fifty-five neonates underwent ECMO support at the Children's Hospital of Georgia at Augusta University from January 1, 2012 to December 31, 2017. Forty-four (80%) had a brain MRI performed prior to transfer or discharge. Ultrasound studies were reviewed by a single blinded pediatric radiologist and MRIs were reviewed by a single blinded neuro-radiologist. Results Of the 44 neonates with post-ECMO MRI, CUS during ECMO identified intracranial lesions in nine neonates, which were all confirmed on post-ECMO MRI. Sixteen subjects (46%) with unremarkable CUS during ECMO had identifiable lesions on post-ECMO MRI, yielding a sensitivity of 36% and a specificity of 100% for CUS in the detection of intracranial lesions. Despite the lack of correlation between CUS and MR, 84.6% of survivors exhibited normal development at 24 months of age. Conclusion While necessary for the identification of intracranial lesions during neonatal ECMO, CUS demonstrated low correlation with post-ECMO MRI in the identification of intracranial lesions, which supports Extracorporeal Life Support Organization (ELSO) recommendations.

Central Vascular Thrombosis in Neonates with Congenital Heart Disease Awaiting Cardiac Intervention.

Central vascular thrombosis (CVT) in critically ill neonates carries significant clinical implications. Neonates with congenital heart disease (CHD) awaiting cardiac intervention might be associated with increased risk of thrombosis. Outcome analysis was undertaken. An analysis of 77 neonates with CHD who were admitted to the NICU prior to cardiac intervention between January 2015 and December 2016 was undertaken. Patients requiring extracorporeal life support prior to any cardiac intervention, or receiving prophylactic anticoagulation not related to central vascular catheter (CVC) were excluded. Diagnosis of CVT was provided based on clinical indication and verified with imaging that warranted anticoagulation therapy. Location of CVC and extent of CVT along with treatments, outcomes, and vascular access types and durations were assessed. Logistic regression multivariate analysis was used to assess predictors of outcome. Neonates with CHD were complicated with CVT in 10.4%. Longer duration of CVC was also associated with thrombosis in neonates with CHD (72.7 days vs. 29.3 days, p < 0.001). Independent predictors of outcome included lower gestational age and CHD with single-ventricle (SV) anatomy (p < 0.05). In neonates with CHD awaiting cardiac intervention risk of CVT is substantial. Duration CVC, lower gestational age and SV anatomy are risk determinants of outcome. Standardized development of customized surveillance protocols tailored to this unique subsets of neonates and adherence to quality guidelines can influence outcome.

Transient inhibition of neddylation at neonatal stage evokes reversible cardiomyopathy and predisposes the heart to isoproterenol-induced heart failure.

Alterations in perinatal conditions (such as preterm birth) is linked to adult health and disease, in particular, the cardiovascular system. Neddylation, a novel posttranslational modification through which the ubiquitin-like protein NEDD8 is conjugated to protein substrates, has emerged as an important mechanism regulating embryonic cardiac chamber maturation. However, the importance of neddylation in postpartum cardiac development has not been investigated. Here, we aimed to determine whether transient, postnatal inhibition of neddylation has immediate and prolonged impact on the structure and function of the neonatal and adult hearts. Sprague-Dawley pups were given three intraperitoneal injections of MLN4924 (MLN), a specific neddylation inhibitor, at postnatal days (P)1, 3, and 5. Cardiac structure and function were temporally assessed during aging and after 2 wk of isoproterenol (ISO) infusion in adulthood. MLN treatment resulted in modest reduction of neddylated proteins in neonatal hearts. The MLN-treated rats developed cardiac hypertrophy and dysfunction by P7, which was accompanied by significantly reduced cardiomyocyte proliferation. At 3 mo of age, cardiac contractile function was restored in MLN-treated rats, but MLN-treated hearts displayed hypertrophic phenotype. Whereas ISO infusion triggered compensatory cardiac hypertrophy without impairing cardiac contractility in the control rats, the MLN-treated rats displayed a similar degree of hypertrophy, which quickly progressed to decompensation with ventricular wall thinning, chamber dilatation, and reduced ejection fraction as well as exacerbated pathological cardiac remodeling. Our findings suggest that neddylation is required for postnatal cardiac development and that perturbation of neddylation during development predisposes adult hearts to cardiac failure under stress conditions. NEW & NOTEWORTHY Our study demonstrates that perinatal perturbation of neddylation induces cardiomyopathy, impairs postnatal cardiac development, and increases susceptibility to catecholamine-induced cardiac dysfunction. The results reveal a previously unappreciated role of neddylation in postnatal cardiac maturation and call for close monitoring for the potential cardiotoxicity of MLN4924 (pevonedistat) and other agents that modify neddylation, especially in pregnant women and preadolescents.

Sleep SAAF: a responsive parenting intervention to prevent excessive weight gain and obesity among African American infants.

BACKGROUND: Responsive parenting interventions that shape parenting behaviors in the areas of sleep and soothing, appropriate and responsive feeding, and routines represent a promising approach to early obesity prevention and have demonstrated effectiveness in our previous trials. However, this approach has yet to be applied to the populations most at-risk for the development of early obesity, including African Americans. The Sleep SAAF (Strong African American Families) study is a two-arm randomized controlled clinical trial evaluating whether a responsive parenting intervention focused on promoting infant sleeping and self-soothing can prevent rapid weight gain during the first 16 weeks postpartum among first-born African American infants. The responsive parenting intervention is compared to a child safety control intervention. METHODS: Three hundred first-time African American mothers and their full-term infants will be enrolled from one mother/baby nursery. Following initial screening and consent in the hospital, mothers and infants are visited at home by Community Research Associates for data collection visits at 1 week, 8 weeks, and 16 weeks postpartum and for intervention visits at 3 weeks and 8 weeks postpartum. The primary study outcome is a between-group comparison of infant conditional weight gain (CWG) scores from 3 weeks to 16 weeks; additional weight-related outcomes include differences in change in infants' weight for age over time and differences in infants' weight outcomes at age 16 weeks. Several other outcomes reflecting infant and maternal responses to intervention (e.g., sleeping, soothing, feeding, maternal self-efficacy, maternal depressive symptoms) are also assessed. DISCUSSION: The Sleep SAAF trial can inform efforts to prevent rapid weight gain and reduce risk for obesity early in the lifespan among African Americans. TRIAL REGISTRATION: NCT03505203 . Registered April 3, 2018 in clinicaltrials.gov .

A novel role for the Wnt inhibitor APCDD1 in adipocyte differentiation: Implications for diet-induced obesity.

Impaired adipogenic differentiation during diet-induced obesity (DIO) promotes adipocyte hypertrophy and inflammation, thereby contributing to metabolic disease. Adenomatosis polyposis coli down-regulated 1 (APCDD1) has recently been identified as an inhibitor of Wnt signaling, a key regulator of adipogenic differentiation. Here we report a novel role for APCDD1 in adipogenic differentiation via repression of Wnt signaling and an epigenetic linkage between miR-130 and APCDD1 in DIO. APCDD1 expression was significantly up-regulated in mature adipocytes compared with undifferentiated preadipocytes in both human and mouse subcutaneous adipose tissues. siRNA-based silencing of APCDD1 in 3T3-L1 preadipocytes markedly increased the expression of Wnt signaling proteins (Wnt3a, Wnt5a, Wnt10b, LRP5, and ß-catenin) and inhibited the expression of adipocyte differentiation markers (CCAAT/enhancer-binding protein α (C/EBPα) and peroxisome proliferator-activated receptor γ (PPARγ)) and lipid droplet accumulation, whereas adenovirus-mediated overexpression of APCDD1 enhanced adipogenic differentiation. Notably, DIO mice exhibited reduced APCDD1 expression and increased Wnt expression in both subcutaneous and visceral adipose tissues and impaired adipogenic differentiation in vitro Mechanistically, we found that miR-130, whose expression is up-regulated in adipose tissues of DIO mice, could directly target the 3'-untranslated region of the APCDD1 gene. Furthermore, transfection of an miR-130 inhibitor in preadipocytes enhanced, whereas an miR-130 mimic blunted, adipogenic differentiation, suggesting that miR-130 contributes to impaired adipogenic differentiation during DIO by repressing APCDD1 expression. Finally, human subcutaneous adipose tissues isolated from obese individuals exhibited reduced expression of APCDD1, C/EBPα, and PPARγ compared with those from non-obese subjects. Taken together, these novel findings suggest that APCDD1 positively regulates adipogenic differentiation and that its down-regulation by miR-130 during DIO may contribute to impaired adipogenic differentiation and obesity-related metabolic disease.

Nf1+/- monocytes/macrophages induce neointima formation via CCR2 activation.

Persons with neurofibromatosis type 1 (NF1) have a predisposition for premature and severe arterial stenosis. Mutations in the NF1 gene result in decreased expression of neurofibromin, a negative regulator of p21(Ras), and increases Ras signaling. Heterozygous Nf1 (Nf1(+/-)) mice develop a marked arterial stenosis characterized by proliferating smooth muscle cells (SMCs) and a predominance of infiltrating macrophages, which closely resembles arterial lesions from NF1 patients. Interestingly, lineage-restricted inactivation of a single Nf1 allele in monocytes/macrophages is sufficient to recapitulate the phenotype observed in Nf1(+/-) mice and to mobilize proinflammatory CCR2+ monocytes into the peripheral blood. Therefore, we hypothesized that CCR2 receptor activation by its primary ligand monocyte chemotactic protein-1 (MCP-1) is critical for monocyte infiltration into the arterial wall and neointima formation in Nf1(+/-) mice. MCP-1 induces a dose-responsive increase in Nf1(+/-) macrophage migration and proliferation that corresponds with activation of multiple Ras kinases. In addition, Nf1(+/-) SMCs, which express CCR2, demonstrate an enhanced proliferative response to MCP-1 when compared with WT SMCs. To interrogate the role of CCR2 activation on Nf1(+/-) neointima formation, we induced neointima formation by carotid artery ligation in Nf1(+/-) and WT mice with genetic deletion of either MCP1 or CCR2. Loss of MCP-1 or CCR2 expression effectively inhibited Nf1(+/-) neointima formation and reduced macrophage content in the arterial wall. Finally, administration of a CCR2 antagonist significantly reduced Nf1(+/-) neointima formation. These studies identify MCP-1 as a potent chemokine for Nf1(+/-) monocytes/macrophages and CCR2 as a viable therapeutic target for NF1 arterial stenosis.

The lifelong impact of fetal growth restriction on cardiac development.

BACKGROUND: Maternal nutrient restriction (MNR) is a widespread cause of fetal growth restriction (FGR), an independent predictor of heart disease and cardiovascular mortality. Our objective was to examine the developmental and long-term impact of MNR-induced FGR on cardiac structure in a model that closely mimics human development. METHODS: A reduction in total caloric intake spanning pregestation through to lactation in guinea pig sows was used to induce FGR. Proliferation, differentiation, and apoptosis of cardiomyocytes were assessed in late-gestation fetal, neonatal, and adult guinea pig hearts. Proteomic analysis and pathway enrichment were performed on fetal hearts. RESULTS: Cardiomyocyte proliferation and the number of mononucleated cells were enhanced in the MNR-FGR fetal and neonatal heart, suggesting a delay in cardiomyocyte differentiation. In fetal hearts of MNR-FGR animals, apoptosis was markedly elevated and the total number of cardiomyocytes reduced, the latter remaining so throughout neonatal and into adult life. A reduction in total cardiomyocyte number in adult MNR-FGR hearts was accompanied by exaggerated hypertrophy and a disorganized architecture. Pathway analysis identified genes related to cell proliferation, differentiation, and survival. CONCLUSIONS: FGR influences cardiomyocyte development during critical windows of development, leading to a permanent deficiency in cardiomyocyte number and compensatory hypertrophy in a rodent model that recapitulates human development.