23 research outputs found

    Interactions between nuclear receptor SHP and FOXA1 maintain oscillatory homocysteine homeostasis in mice

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    Background & Aims Hyperhomocysteinemia is often associated with liver and metabolic diseases. We studied nuclear receptors that mediate oscillatory control of homocysteine homeostasis in mice. Methods We studied mice with disruptions in Nr0b2 (called small heterodimer partner [SHP]-null mice), betaine-homocysteine S-methyltransferase (Bhmt), or both genes (BHMT-null/SHP-null mice), along with mice with wild-type copies of these genes (controls). Hyperhomocysteinemia was induced by feeding mice alcohol (National Institute on Alcohol Abuse and Alcoholism binge model) or chow diets along with water containing 0.18% DL-homocysteine. Some mice were placed on diets containing cholic acid (1%) or cholestyramine (2%) or high-fat diets (60%). Serum and livers were collected during a 24-hour light-dark cycle and analyzed by RNA-seq, metabolomic, and quantitative polymerase chain reaction, immunoblot, and chromatin immunoprecipitation assays. Results SHP-null mice had altered timing in expression of genes that regulate homocysteine metabolism compared with control mice. Oscillatory production of S-adenosylmethionine, betaine, choline, phosphocholine, glyceophosphocholine, cystathionine, cysteine, hydrogen sulfide, glutathione disulfide, and glutathione, differed between SHP-null mice and control mice. SHP inhibited transcriptional activation of Bhmt and cystathionine γ-lyase by FOXA1. Expression of Bhmt and cystathionine γ-lyase was decreased when mice were fed cholic acid but increased when they were placed on diets containing cholestyramine or high-fat content. Diets containing ethanol or homocysteine induced hyperhomocysteinemia and glucose intolerance in control, but not SHP-null, mice. In BHMT-null and BHMT-null/SHP-null mice fed a control liquid, lipid vacuoles were observed in livers. Ethanol feeding induced accumulation of macrovesicular lipid vacuoles to the greatest extent in BHMT-null and BHMT-null/SHP-null mice. Conclusions Disruption of Shp in mice alters timing of expression of genes that regulate homocysteine metabolism and the liver responses to ethanol and homocysteine. SHP inhibits the transcriptional activation of Bhmt and cystathionine γ-lyase by FOXA1

    Quantifying Sources of Variability in Infancy Research Using the Infant-Directed-Speech Preference

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    Psychological scientists have become increasingly concerned with issues related to methodology and replicability, and infancy researchers in particular face specific challenges related to replicability: For example, high-powered studies are difficult to conduct, testing conditions vary across labs, and different labs have access to different infant populations. Addressing these concerns, we report on a large-scale, multisite study aimed at (a) assessing the overall replicability of a single theoretically important phenomenon and (b) examining methodological, cultural, and developmental moderators. We focus on infants’ preference for infant-directed speech (IDS) over adult-directed speech (ADS). Stimuli of mothers speaking to their infants and to an adult in North American English were created using seminaturalistic laboratory-based audio recordings. Infants’ relative preference for IDS and ADS was assessed across 67 laboratories in North America, Europe, Australia, and Asia using the three common methods for measuring infants’ discrimination (head-turn preference, central fixation, and eye tracking). The overall meta-analytic effect size (Cohen’s d) was 0.35, 95% confidence interval = [0.29, 0.42], which was reliably above zero but smaller than the meta-analytic mean computed from previous literature (0.67). The IDS preference was significantly stronger in older children, in those children for whom the stimuli matched their native language and dialect, and in data from labs using the head-turn preference procedure. Together, these findings replicate the IDS preference but suggest that its magnitude is modulated by development, native-language experience, and testing procedure

    Simple amphiphilic α-hydrazido acids: Rational design, synthesis, and in vitro bioactivity profile of a novel class of potential antimicrobial compounds

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    Pursuing the search for a new class of structurally simple mimics of antimicrobial peptides, we optimized a short, cheap and high-yielding synthesis of mono-charged amphiphilic α-hydrazido acid derivatives. The most active derivatives furnished MICs that are among the best values reported in literature for synthetic amphiphilic membranolytic compounds. They exhibited a broad-spectrum in vitro activity against a variety of Gram-positive and Gram-negative bacteria, including two multidrug-resistant strains. In spite of the minimal cationic charge, the best compounds demonstrated to be selective toward bacterial cell membranes over mammalian cell membranes. The relationship between either the antibacterial or the hemolytic activity and the overall lipophilicity furnished an easy way to individuate the best dimensional range for the hydrophobic portions. The importance of a non-disrupted amphiphilicity was also demonstrated. Considering the bioactivity profile and the ease of synthesis, these chemically and proteolitically stable hydrochlorides are suitable for development of a new class of wide-spectrum antibiotics

    Humoral and cell-mediated immune responses to BNT162b2 vaccine against SARS-CoV-2 in people with cystic fibrosis

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    People with cystic fibrosis (pwCF) were considered to be clinically vulnerable to COVID-19 and were therefore given priority in the vaccination campaign. Vaccines induced a humoral response in these patients that was comparable to the response observed among the general population. However, the role of the cell-mediated immune response in providing long-term protection against SARS-CoV-2 in pwCF has not yet been defined. In this study, humoral (antibody titre) and cell-mediated immune responses (interferon-γ release) to the BNT162b2 vaccine were measured at different time points, from around 6–8 months after the 2nd dose and up to 8 months after the 3rd dose, in 118 CF patients and 26 non-CF subjects. Subjects were sampled between November 2021 and September 2022 and followed-up for breakthrough infection through October 2022. pwCF mounted a cell-mediated response that was similar to that observed in non-CF subjects. Low antibody titres (<1st quartile) were associated with a higher risk of breakthrough infection (HR: 2.39, 95 % CI: 1.17–4.88), while there was no significant association with low INF-γ levels (<0.3 IU/mL) (HR: 1.38, 95 % CI: 0.64–2.99). Further studies are needed in subgroup of pwCF receiving immunosuppressive therapy, such as organ transplant recipients. This data is important for tailoring vaccination strategies for this clinically vulnerable population

    Mechanochemical Synthesis and Biological Evaluation of Novel Isoniazid Derivatives with Potent Antitubercular Activity.

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    A series of isoniazid derivatives bearing a phenolic or heteroaromatic coupled frame were obtained by mechanochemical means. Their pH stability and their structural (conformer/isomer) analysis were checked. The activity of prepared derivatives against Mycobacterium tuberculosis cell growth was evaluated. Some compounds such as phenolic hydrazine 1a and almost all heteroaromatic ones, especially 2, 5 and 7, are more active than isoniazid, and their activity against some M. tuberculosis MDR clinical isolates was determined. Compounds 1a and 7 present a selectivity index >1400 evaluated on MRC5 human fibroblast cells. The mechanism of action of selected hydrazones was demonstrated to block mycolic acid synthesis due to InhA inhibition inside the mycobacterial cell

    The Wilson disease gene is a putative copper transporting P-type ATPase similar to the Menkes gene.

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    Wilson disease (WD) is an autosomal recessive disorder of copper transport, resulting in copper accumulation and toxicity to the liver and brain. The gene (WD) has been mapped to chromosome 13 q14.3. On yeast artificial chromosomes from this region we have identified a sequence, similar to that coding for the proposed copper binding regions of the putative ATPase gene (MNK) defective in Menkes disease. We show that this sequence forms part of a P-type ATPase gene (referred to here as Wc1) that is very similar to MNK, with six putative metal binding regions similar to those found in prokaryotic heavy metal transporters. The gene, expressed in liver and kidney, lies within a 300 kb region likely to include the WD locus. Two WD patients were found to be homozygous for a seven base deletion within the coding region of Wc1. Wc1 is proposed as the gene for WD
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