1,635 research outputs found
DNA methylation-based age prediction and telomere length in white blood cells and cumulus cells of infertile women with normal or poor response to ovarian stimulation.
An algorithm assessing the methylation levels of 353 informative CpG sites in the human genome permits accurate prediction of the chronologic age of a subject. Interestingly, when there is discrepancy between the predicted age and chronologic age (age acceleration or AgeAccel ), patients are at risk for morbidity and mortality. Identification of infertile patients at risk for accelerated reproductive senescence may permit preventative action. This study aimed to assess the accuracy of the epigenetic clock concept in reproductive age women undergoing fertility treatment by applying the age prediction algorithm in peripheral (white blood cells [WBCs]) and follicular somatic cells (cumulus cells [CCs]), and to identify whether women with premature reproductive aging (diminished ovarian reserve) were at risk of AgeAccel in their age prediction. Results indicated that the epigenetic algorithm accurately predicts age when applied to WBCs but not to CCs. The age prediction of CCs was substantially younger than chronologic age regardless of the patient\u27s age or response to stimulation. In addition, telomeres of CCs were significantly longer than that of WBCs. Our findings suggest that CCs do not demonstrate changes in methylome-predicted age or telomere-length in association with increasing female age or ovarian response to stimulation
Quantification of O-glycosylation stoichiometry and dynamics using resolvable mass tags
Mechanistic studies of O-GlcNAc glycosylation have been limited by an inability to monitor the glycosylation stoichiometries of proteins obtained from cells. Here we describe a powerful method to visualize the O-GlcNAcâmodified protein subpopulation using resolvable polyethylene glycol mass tags. This approach enables rapid quantification of in vivo glycosylation levels on endogenous proteins without the need for protein purification, advanced instrumentation or expensive radiolabels. In addition, it establishes the glycosylation state (for example, mono-, di-, tri-) of proteins, providing information regarding overall O-GlcNAc site occupancy that cannot be obtained using mass spectrometry. Finally, we apply this strategy to rapidly assess the complex interplay between glycosylation and phosphorylation and discover an unexpected reverse 'yin-yang' relationship on the transcriptional repressor MeCP2 that was undetectable by traditional methods. We anticipate that this mass-tagging strategy will advance our understanding of O-GlcNAc glycosylation, as well as other post-translational modifications and poorly understood glycosylation motifs
The hâSbxWO3+2x Oxygen Excess Antimony Tungsten Bronze
We describe the previously unreported oxygen excess hexagonal antimony tungsten bronze with composition Sb0.5W3O10, in the following denoted as hâSbxWO3+2x with x=0.167, to demonstrate its analogy to classical AxWO3 tungsten bronzes. This compound forms in a relatively narrow temperature range between 580â°C<T<620â°C. It was obtained as a darkâblue polycrystalline powder, and as thin, needleâshaped, blue single crystals. hâSbxWO3+2x crystallizes in the hexagonal space group P6/mmm with the cell parameters a=7.4369(4)â
Ă
and c=3.7800(2) Ă
. The antimony and excess oxygen occupy the hexagonal channels within the network of cornerâsharing WO6 octahedra. hâSbxWO3+2x has a resistivity of Ï300â
Kâ1.28â
mΩ cm at room temperature, with little if any temperatureâdependence on cooling. DFT calculations on a simplified model for this compound find a metallicâlike electronic structure with the Fermi level falling within rather flat bands, especially around the Î point
Strain-induced enhancement of in infinite-layer PrSrNiO films
The mechanism of unconventional superconductivity in correlated materials
remains a great challenge in condensed matter physics. The recent discovery of
superconductivity in infinite-layer nickelates, as analog to high-Tc cuprates,
has opened a new route to tackle this challenge. By growing 8 nm Pr0.8Sr0.2NiO2
films on the (LaAlO3)0.3(Sr2AlTaO6)0.7 substrate, we successfully raise the
transition temperature Tc from 9 K in the widely studied SrTiO3-substrated
nickelates into 15 K. By combining x-ray absorption spectroscopy with the
first-principles and many-body simulations, we find a positive correlation
between Tc and the pre-edge peak intensity, which can be attributed to the
hybridization between Ni and O orbitals induced by the strain. Our result
suggests that structural engineering can further enhance unconventional
superconductivity, and the charge-transfer property plays a crucial role in the
pairing strength.Comment: 8 pages, 4 figure
Spire, an Actin Nucleation Factor, Regulates Cell Division during Drosophila Heart Development
The Drosophila dorsal vessel is a beneficial model system for studying the regulation of early heart development. Spire (Spir), an actin-nucleation factor, regulates actin dynamics in many developmental processes, such as cell shape determination, intracellular transport, and locomotion. Through protein expression pattern analysis, we demonstrate that the absence of spir function affects cell division in Myocyte enhancer factor 2-, Tinman (Tin)-, Even-skipped- and Seven up (Svp)-positive heart cells. In addition, genetic interaction analysis shows that spir functionally interacts with Dorsocross, tin, and pannier to properly specify the cardiac fate. Furthermore, through visualization of double heterozygous embryos, we determines that spir cooperates with CycA for heart cell specification and division. Finally, when comparing the spir mutant phenotype with that of a CycA mutant, the results suggest that most Svp-positive progenitors in spir mutant embryos cannot undergo full cell division at cell cycle 15, and that Tin-positive progenitors are arrested at cell cycle 16 as double-nucleated cells. We conclude that Spir plays a crucial role in controlling dorsal vessel formation and has a function in cell division during heart tube morphogenesis
From cacti to carnivores: Improved phylotranscriptomic sampling and hierarchical homology inference provide further insight into the evolution of Caryophyllales
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/143660/1/ajb21069.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/143660/2/ajb21069_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/143660/3/ajb21069-sup-0002-AppendixS2.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/143660/4/ajb21069-sup-0005-AppendixS5.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/143660/5/ajb21069-sup-0001-AppendixS1.pd
PAK3 Exacerbates Cardiac Lipotoxicity via SREBP1c in Obesity Cardiomyopathy
Obesity-induced lipid overload in cardiomyocytes contributes to profound oxidative stress and cardiomyopathy, culminating in heart failure. In this study, we investigate a novel mechanism whereby lipids accumulate in cardiomyocytes and seek the relevant treatment strategies. P21-activated kinase 3 (PAK3) was elevated in obese human myocardium, and the murine hearts and cardiomyocytes upon diet- or fatty acid-induced stress, respectively. Mice with cardiac-specific overexpression of PAK3 were more susceptible to the development of cardiac dysfunction upon diet stress, at least partially, due to increased deposition of toxic lipids within the myocardium. Mechanistically, PAK3 promoted the nuclear expression of sterol regulatory element binding protein 1c (SREBP1c) through activation of mammalian target of rapamycin (mTOR) and ribosomal protein S6 kinase beta-1 (S6K1) pathway in cardiomyocytes, resulting in abnormal lipid genes profile, accumulation of excessive lipids, and oxidative stress. More importantly, PAK3 knockdown attenuated fatty acid-induced lipotoxicity and cell death in rat and human cardiomyocytes. More importantly, the S6K1 or SREBP1c inhibitor alleviated PAK3-triggered intracellular lipid overload and cardiac dysfunction under obese stress. Collectively, we have demonstrated that PAK3 impairs myocardial lipid homeostasis, while inhibition of cardiac lipotoxicity mitigates cardiac dysfunction. Our study provides a promising therapeutic strategy for ameliorating obesity cardiomyopathy.<br/
Choice of Bacterial Growth Medium Alters the Transcriptome and Phenotype of Salmonella enterica Serovar Typhimurium
The type of bacterial culture medium is an important consideration during design of any experimental protocol. The aim of this study was to understand the impact of medium choice on bacterial gene expression and physiology by comparing the transcriptome of Salmonella enterica SL1344 after growth in the widely used LB broth or the rationally designed MOPS minimal medium. Transcriptomics showed that after growth in MOPS minimal media, compared to LB, there was increased expression of 42 genes involved in amino acid synthesis and 23 genes coding for ABC transporters. Seven flagellar genes had decreased expression after growth in MOPS minimal medium and this correlated with a decreased motility. In both MOPS minimal medium and MEM expression of genes from SPI-2 was increased and the adhesion of S. Typhimurium to intestinal epithelial cells was higher compared to the levels after growth in LB. However, SL1344 invasion was not significantly altered by growth in either MOPs minimal media or MEM. Expression of SPI-2 was also measured using chromosomal GFP reporter fusions followed by flow cytometry which showed, for the first time, that the reduction in SPI-2 transcript after growth in different media related to a reduction in the proportion of the bacterial population expressing SPI-2. These data highlight the profound differences in the global transcriptome after in vitro growth in different media and show that choice of medium should be considered carefully during experimental design, particularly when virulence related phenotypes are being measured
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