Mice lacking sialyltransferase ST3Gal-II develop late-onset obesity and insulin resistance

Sialyltransferases are a family of 20 gene products in mice and humans that transfer sialic acid from its activated precursor, CMP-sialic acid, to the terminus of glycoprotein and glycolipid acceptors. ST3Gal-II (coded by the St3gal2 gene) transfers sialic acid preferentially to the three positions of galactose on the Galβ1-3GalNAc terminus of gangliosides GM1 and GD1b to synthesize GD1a and GT1b, respectively. Mice with a targeted disruption of St3gal2 unexpectedly displayed lateonset obesity and insulin resistance. At 3 months of age, St3gal2-null mice were the same weight as their wild type (WT) counterparts, but by 13 months on standard chow they were visibly obese, 22% heavier and with 37% greater fat/lean ratio than WT mice. St3gal2-null mice became hyperglycemic and displayed impaired glucose tolerance by 9 months of age. They had sharply reduced insulin responsiveness despite equivalent pancreatic islet morphology. Analyses of insulin receptor (IR) tyrosine kinase substrate IRS-1 and downstream target Akt revealed decreased insulininduced phosphorylation in adipose tissue but not liver or skeletal muscle of St3gal2-null mice. Thin-layer chromatography and mass spectrometry revealed altered ganglioside profiles in the adipose tissue of St3gal2-null mice compared to WT littermates. Metabolically, St3gal2-null mice display a reduced respiratory exchange ratio compared to WT mice, indicating a preference for lipid oxidation as an energy source. Despite their altered metabolism, St3gal2-null mice were hyperactive. We conclude that altered ganglioside expression in adipose tissue results in diminished IR sensitivity and late-onset obesity.Fil: Lopez, Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; Argentina. Johns Hopkins University School of Medicine; Estados UnidosFil: Aja, Susan. Johns Hopkins University School of Medicine; Estados UnidosFil: Aoki, Kazuhiro. University of Georgia; GreciaFil: Seldin, Marcus M.. Johns Hopkins University School of Medicine; Estados UnidosFil: Lei, Xia. Johns Hopkins University School of Medicine; Estados UnidosFil: Ronnett, Gabriele V. Johns Hopkins University School of Medicine; Estados UnidosFil: Wong, G. William. Johns Hopkins University School of Medicine; Estados UnidosFil: Schnaar, Ronald L.. Johns Hopkins University School of Medicine; Estados Unido

What Research Questions Should the Next Generation of Birth Cohort Studies Address? An International Delphi Study of Experts.

OBJECTIVE: Birth cohort studies (BCS) have generated a wealth of invaluable basic scientific and policy-relevant information on a wide range of issues in child health and development. This study sought to explore what research questions are currently a priority for the next generation of BCS using a 3-round Delphi survey of interdisciplinary experts. METHODS: Twenty-four (Round I, N = 17; Round II, N = 21; Round III, N = 18) experts across a wide range of fields (eg, psychology, public health, and maternal/child health) agreed to participate. In Round I, the expert panel was invited to freely respond to the question, "what are the key scientific questions future birth cohort studies should address?" Content analysis of answers was used to identify 47 questions for rating on perceived importance by the panel in Round II and consensus-achieving questions were identified. Questions that did not reach consensus in Round II were posed again for expert re-rating in Round III. RESULTS: Twenty six of 47 questions reached consensus in Round II, with an additional 6 reaching consensus in Round III. Consensus-achieving questions rated highly on importance spanned a number of topics, including environmental effects on child development, intergenerational transmission of disadvantage, and designing BCS to inform intervention strategies. CONCLUSION: Investigating the effects of family/environmental factors and social disadvantage on a child's development should be prioritized in designing future BCS. The panel also recommended that future BCS are designed to inform intervention strategies

Vascular dysfunction in aged mice contributes to persistent lung fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive disease thought to result from impaired lung repair following injury and is strongly associated with aging. While vascular alterations have been associated with IPF previously, the contribution of lung vasculature during injury resolution and fibrosis is not well understood. To compare the role of endothelial cells (ECs) in resolving and non‐resolving models of lung fibrosis, we applied bleomycin intratracheally to young and aged mice. We found that injury in aged mice elicited capillary rarefaction, while injury in young mice resulted in increased capillary density. ECs from the lungs of injured aged mice relative to young mice demonstrated elevated pro‐fibrotic and reduced vascular homeostasis gene expression. Among the latter, Nos3 (encoding the enzyme endothelial nitric oxide synthase, eNOS) was transiently upregulated in lung ECs from young but not aged mice following injury. Young mice deficient in eNOS recapitulated the non‐resolving lung fibrosis observed in aged animals following injury, suggesting that eNOS directly participates in lung fibrosis resolution. Activation of the NO receptor soluble guanylate cyclase in human lung fibroblasts reduced TGFβ‐induced pro‐fibrotic gene and protein expression. Additionally, loss of eNOS in human lung ECs reduced the suppression of TGFβ‐induced lung fibroblast activation in 2D and 3D co‐cultures. Altogether, our results demonstrate that persistent lung fibrosis in aged mice is accompanied by capillary rarefaction, loss of EC identity, and impaired eNOS expression. Targeting vascular function may thus be critical to promote lung repair and fibrosis resolution in aging and IPF.Bleomycin‐induced lung injury promotes transient fibrosis accompanied by increased capillary density in young mice. In contrast, persistent fibrosis, capillary rarefaction, loss of endothelial cell identity, and reduction of Nos3 are observed in aged mice. eNOS/NO signal is an important driver of fibroblast quiescence and fibrosis resolution, that is lost with aging. Lung vascular bed plays a critical role during lung repair and fibrosis resolution.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/156458/2/acel13196_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156458/1/acel13196.pd

Evidence for Better Lives Study: a comparative birth-cohort study on child exposure to violence and other adversities in eight low- and middle-income countries - foundational research (study protocol)

Funder: Consuelo Zobel Alger Foundation, Inc.Funder: British Academy; FundRef: http://dx.doi.org/10.13039/501100000286Funder: Cambridge Humanities Research Grants SchemeFunder: University of Cambridge GCRF Quality ResearchFunder: Jacobs Foundation; FundRef: http://dx.doi.org/10.13039/501100003986Funder: Wolfson discretionary researchIntroduction: Violence against children is a health, human rights and social problem affecting approximately half of the world’s children. Its effects begin at prenatal stages with long-lasting impacts on later health and well-being. The Evidence for Better Lives Study (EBLS) aims to produce high-quality longitudinal data from cities in eight low- and middle-income countries—Ghana, Jamaica, Pakistan, the Philippines, Romania, South Africa, Sri Lanka and Vietnam—to support effective intervention to reduce violence against children. EBLS-Foundational Research (EBLS-FR) tests critical aspects of the planned EBLS, including participant recruitment and retention, data collection and analysis. Alongside epidemiological estimates of levels and predictors of exposure to violence and adversity during pregnancy, we plan to explore mechanisms that may link exposure to violence to mothers’ biological stress markers and subjective well-being. Methods and analyses: EBLS-FR is a short longitudinal study with a sample of 1200 pregnant women. Data are collected during the last trimester of pregnancy and 2 to 6 months after birth. The questionnaire for participating women has been translated into nine languages. Measures obtained from mothers will include, among others, mental and physical health, attitudes to corporal punishment, adverse childhood experiences, prenatal intimate partner violence, substance use and social/community support. Hair and dry blood spot samples are collected from the pregnant women to measure stress markers. To explore research participation among fathers, EBLS-FR is recruiting 300 fathers in the Philippines and Sri Lanka. Ethics and dissemination: The study received ethical approvals at all recruiting sites and universities in the project. Results will be disseminated through journal publications, conferences and seminar presentations involving local communities, health services and other stakeholders. Findings from this work will help to adjust the subsequent stages of the EBLS project

Measuring Antenatal Depressive Symptoms Across the World: A Validation and Cross-Country Invariance Analysis of the Patient Health Questionnaire-9 (PHQ-9) in Eight Diverse Low-Resource Settings

Measures that produce valid and reliable antenatal depressive symptom scores in low-resource country contexts are important for efforts to illuminate risk factors, outcomes, and effective interventions in these contexts. Establishing the psychometric comparability of scores across countries also facilitates analyses of similarities and differences across contexts. To date, however, few studies have evaluated the psychometric properties and comparability of the most widely used antenatal depressive symptom measures across diverse cultural, political, and social contexts. To address this gap, we used data from the Evidence for Better Lives Study—Foundational Research (EBLS-FR) project to examine the internal consistency reliability, nomological network validity, and cross-country measurement invariance of the nine-item version of the Patient Health Questionnaire (PHQ-9) in antenatal samples across eight low-resource contexts. We found that the PHQ-9 scores had good internal consistency across all eight countries. Correlations between PHQ-9 scores and constructs conceptually associated with depression were generally consistent, with a few exceptions. In measurement invariance analyses, only partial metric invariance held and only across four of the countries. Our results suggest that the PHQ-9 yields internally consistent scores when administered in culturally diverse antenatal populations; however, the meaning of the scores may vary. Thus, interpretation of PHQ-9 scores should consider local meanings of symptoms of depression to ensure that context-specific conceptualizations and manifestations of antenatal depressive symptoms are adequately reflecte

Measuring antenatal depressive symptoms across the world:A validation and cross-country invariance analysis of the patient health questionnaire-9 (PHQ-9) in eight diverse low-resource settings

Measures that produce valid and reliable antenatal depressive symptom scores in low-resource country contexts are important for efforts to illuminate risk factors, outcomes, and effective interventions in these contexts. Establishing the psychometric comparability of scores across countries also facilitates analyses of similarities and differences across contexts. To date, however, few studies have evaluated the psychometric properties and comparability of the most widely used antenatal depressive symptom measures across diverse cultural, political, and social contexts. To address this gap, we used data from the Evidence for Better Lives Study—Foundational Research (EBLS-FR) project to examine the internal consistency reliability, nomological network validity, and cross-country measurement invariance of the nine-item version of the Patient Health Questionnaire (PHQ-9) in antenatal samples across eight low-resource contexts. We found that the PHQ-9 scores had good internal consistency across all eight countries. Correlations between PHQ-9 scores and constructs conceptually associated with depression were generally consistent, with a few exceptions. In measurement invariance analyses, only partial metric invariance held and only across four of the countries. Our results suggest that the PHQ-9 yields internally consistent scores when administered in culturally diverse antenatal populations; however, the meaning of the scores may vary. Thus, interpretation of PHQ-9 scores should consider local meanings of symptoms of depression to ensure that context-specific conceptualizations and manifestations of antenatal depressive symptoms are adequately reflected.</p

Perceived stress during the prenatal period: assessing measurement invariance of the Perceived Stress Scale (PSS-10) across cultures and birth parity

Maternal prenatal stress places a substantial burden on mother’s mental health. Expectant mothers in low- and middle-income countries (LMICs) have thus far received less attention than mothers in high-income settings. This is particularly problematic, as a range of triggers, such as exposure to traumatic events (e.g. natural disasters, previous pregnancy losses) and adverse life circumstances (e.g. poverty, community violence), put mothers at increased risk of experiencing prenatal stress. The ten-item Perceived Stress Scale (PSS-10) is a widely recognised index of subjective experience of stress that is increasingly used in LMICs. However, evidence for its measurement equivalence across settings is lacking. This study aims to assess measurement invariance of the PSS-10 across eight LMICs and across birth parity. This research was carried out as part of the Evidence for Better Lives Study (EBLS, vrc.crim.cam.ac.uk/vrcresearch/EBLS). The PSS-10 was administered to N = 1,208 expectant mothers from Ghana, Jamaica, Pakistan, the Philippines, Romania, South Africa, Sri Lanka and Vietnam during the third trimester of pregnancy. Confirmatory factor analysis suggested a good model fit of a two-factor model across all sites, with items on experiences of stress loading onto a negative factor and items on perceived coping onto a positive factor. Configural and metric, but not full or partial scalar invariance, were established across all sites. Configural, metric and full scalar invariance could be established across birth parity. On average, first-time mothers reported less stress than mothers who already had children. Our findings indicate that the PSS-10 holds utility in assessing stress across a broad range of culturally diverse settings; however, caution should be taken when comparing mean stress levels across sites

Prenatal attachment: using measurement invariance to test the validity of comparisons across eight culturally diverse countries

Funder: Jacobs Foundation; doi: http://dx.doi.org/10.13039/501100003986Funder: the Consuelo Zobel Alger FoundationFunder: The British AcademyFunder: the Cambridge Humanities Research Grants SchemeFunder: the University of Edinburgh College Office for the College of ArtsFunder: the Wolfson Professor of Criminology Discretionary FundAbstract: Studies in high-income countries (HICs) have shown that variability in maternal-fetal attachment (MFA) predict important maternal health and child outcomes. However, the validity of MFA ratings in low- and middle-income countries (LMICs) remains unknown. Addressing this gap, we assessed measurement invariance to test the conceptual equivalence of the Prenatal Attachment Inventory (PAI: Muller, 1993) across eight LMICs. Our aim was to determine whether the PAI yields similar information from pregnant women across different cultural contexts. We administered the 18-item PAI to 1181 mothers in the third trimester (Mean age = 28.27 years old, SD = 5.81 years, range = 18–48 years) expecting their first infant (n = 359) or a later-born infant (n = 820) as part of a prospective birth cohort study involving eight middle-income countries: Ghana, Jamaica, Pakistan, Philippines, Romania, South Africa, Sri Lanka and Vietnam. We used Multiple Group Confirmatory Factor Analyses to assess across-site measurement invariance. A single latent factor with partial measurement invariance was found across all sites except Pakistan. Group comparisons showed that mean levels of MFA were lowest for expectant mothers in Vietnam and highest for expectant mothers in Sri Lanka. MFA was higher in first-time mothers than in mothers expecting a later-born child. The PAI yields similar information about MFA across culturally distinct middle-income countries. These findings strengthen confidence in the use of the tool across different settings; future studies should explore the use of the PAI as a screen for maternal behaviour that place children at risk

Correction to: Prenatal attachment: Using measurement invariance to test the validity of comparisons across eight culturally diverse countries.

A Correction to this paper has been published: https://doi.org/10.1007/s00737-021-01122-7Fondation Botna