Parent-of-origin-specific allelic associations among 106 genomic loci for age at menarche.

Age at menarche is a marker of timing of puberty in females. It varies widely between individuals, is a heritable trait and is associated with risks for obesity, type 2 diabetes, cardiovascular disease, breast cancer and all-cause mortality. Studies of rare human disorders of puberty and animal models point to a complex hypothalamic-pituitary-hormonal regulation, but the mechanisms that determine pubertal timing and underlie its links to disease risk remain unclear. Here, using genome-wide and custom-genotyping arrays in up to 182,416 women of European descent from 57 studies, we found robust evidence (P < 5 × 10(-8)) for 123 signals at 106 genomic loci associated with age at menarche. Many loci were associated with other pubertal traits in both sexes, and there was substantial overlap with genes implicated in body mass index and various diseases, including rare disorders of puberty. Menarche signals were enriched in imprinted regions, with three loci (DLK1-WDR25, MKRN3-MAGEL2 and KCNK9) demonstrating parent-of-origin-specific associations concordant with known parental expression patterns. Pathway analyses implicated nuclear hormone receptors, particularly retinoic acid and γ-aminobutyric acid-B2 receptor signalling, among novel mechanisms that regulate pubertal timing in humans. Our findings suggest a genetic architecture involving at least hundreds of common variants in the coordinated timing of the pubertal transition

The earliest thymic T cell progenitors sustain B cell and myeloid lineage potential

The stepwise commitment from hematopoietic stem cells in the bone marrow to T lymphocyte-restricted progenitors in the thymus represents a paradigm for understanding the requirement for distinct extrinsic cues during different stages of lineage restriction from multipotent to lineage-restricted progenitors. However, the commitment stage at which progenitors migrate from the bone marrow to the thymus remains unclear. Here we provide functional and molecular evidence at the single-cell level that the earliest progenitors in the neonatal thymus had combined granulocyte-monocyte, T lymphocyte and B lymphocyte lineage potential but not megakaryocyte-erythroid lineage potential. These potentials were identical to those of candidate thymus-seeding progenitors in the bone marrow, which were closely related at the molecular level. Our findings establish the distinct lineage-restriction stage at which the T cell lineage-commitment process transits from the bone marrow to the remote thymus. © 2012 Nature America, Inc. All rights reserved

New genetic loci link adipose and insulin biology to body fat distribution.

Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms

Phagocytosis of type III group B streptococci by neonatal monocytes: Enhancement by fibronectin and gammaglobulin

The potential of fibronectin to enhance phagocytosis of type III group B streptococci by cultured neonatal monocytes was evaluated. Fibronectin had significantly less effect on phagocytosis compared with type-specific antibody to group B streptococci; fibronectin increased the cell association of organisms to a level comparable to that of adult pooled serum and significantly more than that of serum-free controls. Microbicidal activity suggested that this cell association consisted of attachment but not ingestion, and electron micrographs showed the extracellular location of these organisms. In contrast, the effect of fibronectin on type III group B streptococci preopsonized with intravenous gammaglobulin revealed significantly greater numbers of cell-associated organisms than did addition of type-specific antibody to group B streptococci, pooled adult serum plus fibronectin, or serum-free controls. Phagocytosis was similar when assessed by microbicidal activity compared with the cultures with added type-specific antibody and significantly greater when compared with those with added pooled serum, and results were confirmed by electron microscopy. Therefore, fibronectin together with intravenous gammaglobulin enhanced ingestion of type III group B streptococci by neonatal monocytes

Racial/Ethnic Differences in the Correlates of Mental Health Services Use among Pregnant Women with Depressive Symptoms

Objectives To examine correlates of lifetime mental health services (MHS) use among pregnant women reporting prenatal depressive symptoms by race/ethnicity. Methods This cross-sectional population-based study included 81,910 pregnant women with prenatal depressive symptoms using data from the Florida Healthy Start prenatal screening program (2008–2012). Multivariable logistic regression was conducted to ascertain adjusted odds ratios and corresponding 95 % confidence intervals for racial/ethnic differences in the correlates of lifetime MHS use. Results Findings of this study revealed racial/ethnic differences in MHS use among women with prenatal depressive symptoms, the highest rates being among non-Hispanic Whites and the lowest rates among Mexicans and other Hispanics. Most need for care factors, including illness, tobacco use, and physical or emotional abuse, consistently predicted MHS use across racial/ethnic groups after adjusting for covariates. Adjusted associations between predisposing and enabling/restricting factors and MHS use were different for different racial/ethnic groups. Conclusions Racial/ethnic differences in MHS use were found, with pregnant Hispanic women reporting prenatal depressive symptoms being the least likely to use MHS. Our study findings have significant public health implications for targeted intervention for pregnant women with prenatal depressive symptoms

Identification and characterization of AckA-dependent protein acetylation in <i>Neisseria gonorrhoeae</i>

<div><p><i>Neisseria gonorrhoeae</i>, the causative agent of gonorrhea, has a number of factors known to contribute to pathogenesis; however, a full understanding of these processes and their regulation has proven to be elusive. Post-translational modifications (PTMs) of bacterial proteins are now recognized as one mechanism of protein regulation. In the present study, Western blot analyses, with an anti-acetyl-lysine antibody, indicated that a large number of gonococcal proteins are post-translationally modified. Previous work has shown that N^ε-lysine acetylation can occur non-enzymatically with acetyl-phosphate (AcP) as the acetyl donor. In the current study, an acetate kinase mutant (1291<i>ackA</i>), which accumulates AcP, was generated in <i>N</i>. <i>gonorrhoeae</i>. Broth cultures of <i>N</i>. <i>gonorrhoeae</i> 1291wt and 1291<i>ackA</i> were grown, proteins extracted and digested, and peptides containing acetylated-lysines (K-acetyl) were affinity-enriched from both strains. Mass spectrometric analyses of these samples identified a total of 2686 unique acetylation sites. Label-free relative quantitation of the K-acetyl peptides derived from the <i>ackA</i> and wild-type (wt) strains demonstrated that 109 acetylation sites had an <i>ackA</i>/wt ratio>2 and p-values <0.05 in at least 2/3 of the biological replicates and were designated as “AckA-dependent”. Regulated K-acetyl sites were found in ribosomal proteins, central metabolism proteins, iron acquisition and regulation proteins, pilus assembly and regulation proteins, and a two-component response regulator. Since AckA is part of a metabolic pathway, comparative growth studies of the <i>ackA</i> mutant and wt strains were performed. The mutant showed a growth defect under aerobic conditions, an inability to grow anaerobically, and a defect in biofilm maturation. In conclusion, the current study identified AckA-dependent acetylation sites in <i>N</i>. <i>gonorrhoeae</i> and determined that these sites are found in a diverse group of proteins. This work lays the foundation for future studies focusing on specific acetylation sites that may have relevance in gonococcal pathogenesis and metabolism.</p></div

Western blots with (A) MAb Acetyl-K(103) and (B) MAb 2C3 loading control.

<p>Samples were taken from broth-grown cultures of 1291wt and 1291<i>ackA</i> at 3, 6, and 24h. The MAb Acetyl-K(103) blot shows that acetylation levels in 1291<i>ackA</i> are higher at every time-point compared to its parent strain 1291wt. The 2C3 blot confirms that equivalent levels of protein were used in these experiments.</p

Mass spectrometric workflow.

<p>(A) Three biological replicates of <i>N</i>. <i>gonorrhoeae</i> strains 1291wt and 1291<i>ackA</i> were grown overnight in broth cultures. Cells were harvested, washed, and a protein lysate was generated and digested with trypsin. Affinity enrichment for acetyl-lysine (K-acetyl)-containing peptides was performed using a polyclonal anti-acetyl-Lys antibody. Enriched K-acetyl peptides were analyzed by high-resolution label-free LC-MS/MS and quantified using MS1 quantitation. (B) An example of a peptide analyzed by MS1 quantitation using Skyline. MS1 ion chromatograms of the precursor ions for M, M+1, and M+2 for the acetylated peptide IKLD<u><b>K*</b></u>LVSEGFER, at K-329, from the zinc-binding alcohol dehydrogenase protein for 1291wt and 1291<i>ackA</i> are shown. MS1 quantitation was performed by extracting and measuring the peak areas from the most intense isotopic precursors and subsequently comparing the wt and <i>ackA</i> mutant peptides.</p

Analysis of acetylation sites detected in the present study.

<p>A total of 2686 unique acetylation sites from 656 unique acetylated proteins were observed in the current study. Venn diagrams showing the overlap of 1291wt and 1291<i>ackA</i> (A) acetylation sites and (B) acetylated proteins detected in this study. (C) The number of acetylation sites detected per protein was graphed. (D) Lysine acetylation sites that were observed in two or more biological replicates with a 2-fold or greater <i>ackA</i>/wt ratio and a p-value of <0.05 were designated as “AckA-dependent”. The fold change distribution for these 109 “AckA-dependent” acetylation sites from 70 proteins was then graphed. (E-F) IceLogo generated outputs showing the analysis from the +/-10 amino acids relative to the acetylation sites from all “AckA-dependent” sites. In the heatmap output (E) the color schema generated shows the p-value score for significant amino acid positions. Amino acids highlighted in red indicate that this position is less likely to occur, and those highlighted in green are 99% more likely to occur. In the percentage difference output (F), the amino acids shown occur in that position with a significantly higher frequency than what would be expected based on the amino acid frequency in the whole proteome reference set. The larger the letter the higher the preference is for a particular position in the AckA-dependent motifs.</p

Detected acetylation sites were mapped onto the crystal structures that had the highest homology to the gonococcal iron binding and iron regulation proteins HemO and Fur.

<p>(A) Crystal structure of HemO from <i>N</i>. <i>meningitidis</i> (PDB: 1P3T). Possible heme binding sites and the putative O₂ activation site (R98) are shown in green. The distance between the predicted O₂ activation site (R98) and the closest AckA-dependent K-acetyl site (K75) was measured to be 16.5 Å. (B) Crystal structure of Fur from <i>V</i>. <i>cholera</i> (PDB: 2W57). A proposed DNA-binding site (residues 1–84) is shown in green. All three of the common K-acetyl sites mapped to the predicted DNA-binding region of Fur. In both panels K-acetyl sites shown in red were found to be AckA-dependent, and all K-acetyl sites shown in blue were detected in the current study. All residue positions of common K sites are listed as their position in their respective <i>N</i>. <i>gonorrhoeae</i> proteins. Protein databank (PDB) identifications are listed for each structure.</p