In the quest to reconcile public perception of air pollution with scientific measurements, our study introduced a pioneering method involving a gradient boost-regression tree model integrating PM concentration, visibility, and image-based data. Traditional stationary monitoring often falls short of accurately capturing public air quality perceptions, prompting the need for alternative strategies. Leveraging an extensive dataset of over 20,000 public visibility perception evaluations and over 8,000 stationary images, our models effectively quantify diverse air quality perceptions.
View Article and Find Full Text PDFObjective: The purpose of this study was to examine clinical severity, multidimensional development, and adaptive behavioral functioning in younger and older children with Rett syndrome (RTT) in the pseudostationary stage (stage III).
Methods: Fourteen younger (≤10 years of age) and 15 older (11-18 years of age) children with confirmed stage III RTT (assigned to young-RTT and old-RTT groups, respectively) participated in this study. Clinical severity was determined using the Clinical Severity Score (CSS) scale for RTT.
Multiple pathways mediate the repair of DNA double-strand breaks (DSBs), with numerous mechanisms responsible for driving choice between the pathways. Previously, we reported that mutating five putative phosphorylation sites on the non-homologous end joining (NHEJ) factor, Ku70, results in sustained retention of human Ku70/80 at DSB ends and attenuation of DSB repair via homologous recombination (HR). In this study, we generated a knock-in mouse, in which the three conserved putative phosphorylation sites of Ku70 were mutated to alanine to ablate potential phosphorylation (Ku703A/3A), in order to examine if disrupting DSB repair pathway choice by modulating Ku70/80 dynamics at DSB ends results in enhanced genomic instability and tumorigenesis.
View Article and Find Full Text PDFBackground: Few studies have investigated multidimensional developments and free-play movement performance in toddlers with an early diagnosis of autism spectrum disorder (ASD).
Objective: This study compared cognitive, motor, and behavioral developments and free-play movement performance in toddlers with ASD who were full term (FT-ASD), toddlers who were full term and are typically developing (FT-TD), and toddlers who were born preterm and had a very low birth weight (VLBW-PT).
Design: This was a prospective cross-sectional study.
Methods Enzymol
April 2018
DNA double-strand breaks (DSBs) are deleterious DNA lesions that must be properly repaired to maintain genome stability. Agents, generated both exogenously (environmental radiation, dental X-rays, etc.) and endogenously (reactive oxygen species, DNA replication, V(D)J recombination, etc.
View Article and Find Full Text PDFThe combination of live cell imaging and laser micro-irradiation is an important technique to investigate the recruitment and kinetics of DNA repair molecules to DNA damage sites. In this chapter, we describe the detailed methods to study the dynamics of fluorescently tagged ATM protein kinase at laser-induced DNA double strand break (DSB) sites. The same protocol can be applied to analyze the recruitment and kinetics of other potential or known DNA repair proteins to DSB sites.
View Article and Find Full Text PDFMultiple DNA double-strand break (DSB) repair pathways are active in S phase of the cell cycle; however, DSBs are primarily repaired by homologous recombination (HR) in this cell cycle phase. As the non-homologous end-joining (NHEJ) factor, Ku70/80 (Ku), is quickly recruited to DSBs in S phase, we hypothesized that an orchestrated mechanism modulates pathway choice between HR and NHEJ via displacement of the Ku heterodimer from DSBs to allow HR. Here, we provide evidence that phosphorylation at a cluster of sites in the junction of the pillar and bridge regions of Ku70 mediates the dissociation of Ku from DSBs.
View Article and Find Full Text PDFBackground: The DNA-dependent protein kinase (DNA-PK) is a nuclear complex composed of a large catalytic subunit (DNA-PKcs) and a heterodimeric DNA-targeting subunit Ku. DNA-PK is a major component of the non-homologous end-joining (NHEJ) repair mechanism, which is activated in the presence of DNA double-strand breaks induced by ionizing radiation, reactive oxygen species and radiomimetic drugs. We have recently reported that down-regulation of protein kinase CK2 by siRNA interference results in enhanced cell death specifically in DNA-PKcs-proficient human glioblastoma cells, and this event is accompanied by decreased autophosphorylation of DNA-PKcs at S2056 and delayed repair of DNA double-strand breaks.
View Article and Find Full Text PDFRadiotherapy and chemotherapy are effective cancer treatments due to their ability to generate DNA damage. The major lethal lesion is the DNA double-strand break (DSB). Human cells predominantly repair DSBs by non-homologous end joining (NHEJ), which requires Ku70, Ku80, DNA-PKcs, DNA ligase IV and accessory proteins.
View Article and Find Full Text PDFThe cellular response to double-strand breaks (DSBs) in DNA is a complex signalling network, mobilized by the nuclear protein kinase ataxia-telangiectasia mutated (ATM), which phosphorylates many factors in the various branches of this network. A main question is how ATM regulates DSB repair. Here, we identify the DNA repair enzyme polynucleotide kinase/phosphatase (PNKP) as an ATM target.
View Article and Find Full Text PDFDNA damage response is crucial for maintaining genomic integrity and preventing cancer by coordinating the activation of checkpoints and the repair of damaged DNA. Central to DNA damage response are the two checkpoint kinases ATM and ATR that phosphorylate a wide range of substrates. RING finger and WD repeat domain 3 (RFWD3) was initially identified as a substrate of ATM/ATR from a proteomic screen.
View Article and Find Full Text PDFThe cellular response to DNA double-strand breaks (DSBs) is mobilized by the protein kinase ATM, which phosphorylates key players in the DNA damage response (DDR) network. A major question is how ATM controls DSB repair. Optimal repair requires chromatin relaxation at damaged sites.
View Article and Find Full Text PDFThe double-strand break (DSB) is a cytotoxic DNA lesion caused by oxygen radicals, ionizing radiation, and radiomimetic chemicals. Cells cope with DNA damage by activating the DNA damage response (DDR), which leads either to damage repair and cellular survival or to programmed cell death. The main transducer of the DSB response is the nuclear protein kinase ataxia telangiectasia mutated (ATM).
View Article and Find Full Text PDFThe DNA damage response (DDR) is a complex signaling network that is induced by DNA lesions and vigorously activated by double strand breaks (DSBs). The DSB response is mobilized by the nuclear protein kinase ATM, which phosphorylates key players in its various branches. SFPQ (PSF) and NONO (p54) are nuclear proteins that interact with each other and have diverse roles in nucleic acids metabolism.
View Article and Find Full Text PDFUnderstanding the molecular details associated with aberrant high mobility group A2 (HMGA2) gene expression is key to establishing the mechanism(s) underlying its oncogenic potential and effect on the development of therapeutic strategies. Here, we report the involvement of HMGA2 in impairing DNA-dependent protein kinase (DNA-PK) during the nonhomologous end joining (NHEJ) process. We showed that HMGA2-expressing cells displayed deficiency in overall and precise DNA end-joining repair and accumulated more endogenous DNA damage.
View Article and Find Full Text PDFRepair of DNA double-strand breaks (DSBs) is predominantly mediated by nonhomologous end joining (NHEJ) in mammalian cells. NHEJ requires binding of the Ku70-Ku80 heterodimer (Ku70/80) to the DNA ends and subsequent recruitment of the DNA-dependent protein kinase catalytic subunit (DNA-PK(CS)) and the XRCC4/ligase IV complex. Activation of the DNA-PK(CS) serine/threonine kinase requires an interaction with Ku70/80 and is essential for NHEJ-mediated DSB repair.
View Article and Find Full Text PDFXRCC4-like factor (XLF)--also known as Cernunnos--has recently been shown to be involved in non-homologous end-joining (NHEJ), which is the main pathway for the repair of DNA double-strand breaks (DSBs) in mammalian cells. XLF is likely to enhance NHEJ by stimulating XRCC4-ligase IV-mediated joining of DSBs. Here, we report mechanistic details of XLF recruitment to DSBs.
View Article and Find Full Text PDFIntroduction: The hyper-proliferative activity of stromal smooth muscle (SM) cells is believed to be responsible for the pathogenesis of benign prostatic hyperplasia (BPH). We have observed that those stromal cells can differentiate into unrelated specialized cells. We thus hypothesize that stromal cells derived from adults prostate specimens may contain adult stem cells.
View Article and Find Full Text PDFBackground: Benign prostatic hyperplasia (BPH) is characterized as a stromal process. The stroma smooth muscle (SM) may alter its phenotype during the progression of BPH. We have identified gene transcripts that may be differentially expressed in BPH using a differential display method.
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