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Found 35038 matches. Displaying 1-10
Lewis JS, Spenkelink LM, Schauer GD, Yurieva O, Mueller SH, Natarajan V, Kaur G, Maher C, Kay C, O'Donnell ME, van Oijen AM
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Tunability of DNA Polymerase Stability during Eukaryotic DNA Replication

MOLECULAR CELL 2020 JAN 2; 77(1):17-25.e5
Structural and biochemical studies have revealed the basic principles of how the replisome duplicates genomic DNA, but little is known about its dynamics during DNA replication. We reconstitute the 34 proteins needed to form the S. cerevisiae replisome and show how changing local concentrations of the key DNA polymerases tunes the ability of the complex to efficiently recycle these proteins or to dynamically exchange them. Particularly, we demonstrate redundancy of the Pol alpha-primase DNA polymerase activity in replication and show that Pol alpha-primase and the lagging-strand Pol delta can be re-used within the replisome to support the synthesis of large numbers of Okazaki fragments. This unexpected malleability of the replisome might allow it to deal with barriers and resource challenges during replication of large genomes.
Serrano-Saiz E, Vogt MC, Levy S, Wang Y, Kaczmarczyk KK, Mei X, Bai G, Singson A, Grant BD, Hobert O
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SLC17A6/7/8 Vesicular Glutamate Transporter Homologs in Nematodes

GENETICS 2020 JAN; 214(1):163-178
Members of the superfamily of solute carrier (SLC) transmembrane proteins transport diverse substrates across distinct cellular membranes. Three SLC protein families transport distinct neurotransmitters into synaptic vesicles to enable synaptic transmission in the nervous system. Among them is the SLC17A6/7/8 family of vesicular glutamate transporters, which endows specific neuronal cell types with the ability to use glutamate as a neurotransmitter. The genome of the nematode Caenorhabditis elegans encodes three SLC17A6/7/8 family members, one of which, /VGLUT, has been shown to be involved in glutamatergic neurotransmission. Here, we describe our analysis of the two remaining, previously uncharacterized SLC17A6/7/8 family members, and . These two genes directly neighbor one another and are the result of a recent gene duplication event in C. elegans, but not in other Caenorhabditis species. Compared to , the and protein sequences display a more distant similarity to canonical, vertebrate VGLUT proteins. We tagged both genomic loci with gfp and detected no expression of at any stage of development in any cell type of both C. elegans sexes. In contrast, vglu-2::gfp is dynamically expressed in a restricted set of distinct cell types. Within the nervous system, ::gfp is exclusively expressed in a single interneuron class, AIA, where it localizes to vesicular structures in the soma, but not along the axon, suggesting that may not be involved in synaptic transport of glutamate. Nevertheless, mutants are partly defective in the function of the AIA neuron in olfactory behavior. Outside the nervous system, is expressed in collagen secreting skin cells where most prominently localizes to early endosomes, and to a lesser degree to apical clathrin-coated pits, the trans-Golgi network, and late endosomes. On early endosomes, colocalizes most strongly with the recycling promoting factor , a retromer component. Loss of affects the permeability of the collagen-containing cuticle of the worm, and based on the function of a vertebrate VGLUT1 protein in osteoclasts, we speculate that may have a role in collagen trafficking in the skin. We conclude that C. elegans SLC17A6/7/8 family members have diverse functions within and outside the nervous system.
Callewaert C, Nakatsuji T, Knight R, Kosciolek T, Vrbanac A, Kotol P, Ardeleanu M, Hultsch T, Guttman-Yassky E, Bissonnette R, Silverberg JI, Krueger J, Menter A, Graham NMH, Pirozzi G, Hamilton JD, Gallo RL
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IL-4R alpha Blockade by Dupilumab Decreases Staphylococcus aureus Colonization and Increases Microbial Diversity in Atopic Dermatitis

Dupilumab is a fully human antibody to interleukin-4 receptor alpha that improves the signs and symptoms of moderate to severe atopic dermatitis (AD). To determine the effects of dupilumab on Staphylococcus aureus colonization and microbial diversity on the skin, bacterial DNA was analyzed from swabs collected from lesional and nonlesional skin in a double-blind, placebo-controlled study of 54 patients with moderate to severe AD randomized (1:1) and treated with either dupilumab (200 mg weekly) or placebo for 16 weeks. Microbial diversity and relative abundance of Staphylococcus were assessed by DNA sequencing of 16S ribosomal RNA, and absolute S. aureus abundance was measured by quantitative PCR. Before treatment, lesional skin had lower microbial diversity and higher overall abundance of S. aureus than nonlesional skin. During dupilumab treatment, microbial diversity increased and the abundance of S. aureus decreased. Pronounced changes were seen in nonlesional and lesional skin. Decreased S. aureus abundance during dupilumab treatment correlated with clinical improvement of AD and biomarkers of type 2 immunity. We conclude that clinical improvement of AD that is mediated by interleukin-4 receptor alpha inhibition and the subsequent suppression of type 2 inflammation is correlated with increased microbial diversity and reduced abundance of S. aureus.
Chang JWC, Shih CL, Wang CL, Luo JD, Wang CW, Hsieh JJ, Yu CJ, Chiou CC
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Transcriptomic Analysis in Liquid Biopsy Identifies Circulating PCTAIRE-1 mRNA as a Biomarker in NSCLC

Background/Aim: Circulating mRNA can be a useful source of cancer biomarkers. We took advantage of direct transcriptomic analysis in plasma RNA to identify novel mRNA markers for non-small cell lung cancer (NSCLC). Patients and Methods: Plasma RNA from NSCLC patients and healthy individuals was profiled with cDNA-mediated annealing, selection, extension and ligation (DASL) microarrays. The microarray results were further validated in plasma RNA. Results: Through RNA profiling and online database mining, four gene transcripts were filtered as candidate markers of NSCLC. After validation, the PCTAIRE-1 transcript was identified as a circulating mRNA marker. The diagnostic potential of PCTAIRE-1 was evaluated by receiver operating characteristic curve analysis, which gave a sensitivity and specificity of 60% and 85%, respectively. In addition, high plasma PCTK1 levels were also correlated with poor progression free survival (p=0.008). Conclusion: Circulating mRNA can be profiled with the DASL assay. From the profile, PCTAIRE-1 RNA in the plasma we discovered as a novel diagnostic/prognostic biomarker and an indicator of poor survival in NSCLC patients.
Donovan FX, Solanki A, Mori M, Chavan N, George M, Kumar CS, Okuno Y, Muramastsu H, Yoshida K, Shimamoto A, Takaori-Kondo A, Yabe H, Ogawa S, Kojima S, Yabe M, Ramanagoudr-Bhojappa R, Smogorzewska A, Mohan S, Rajendran A, Auerbach AD, Takata M, Chandrasekharappa SC, Vundinti BR
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A founder variant in the South Asian population leads to a high prevalence of FANCL Fanconi anemia cases in India

HUMAN MUTATION 2020 JAN; 41(1):122-128
Fanconi anemia (FA) is a rare genetic disorder characterized by bone marrow failure, predisposition to cancer, and congenital abnormalities. FA is caused by pathogenic variants in any of 22 genes involved in the DNA repair pathway responsible for removing interstrand crosslinks. FANCL, an E3 ubiquitin ligase, is an integral component of the pathway, but patients affected by disease-causing FANCL variants are rare, with only nine cases reported worldwide. We report here a FANCL founder variant, anticipated to be synonymous, c.1092G>A;p.K364=, but demonstrated to induce aberrant splicing, c.1021_1092del;p.W341_K364del, that accounts for the onset of FA in 13 cases from South Asia, 12 from India and one from Pakistan. We comprehensively illustrate the pathogenic nature of the variant, provide evidence for a founder effect, and propose including this variant in genetic screening of suspected FA patients in India and Pakistan, as well as those with ancestry from these regions of South Asia.
Mirman Z, de Lange T
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53BP1: a DSB escort

GENES & DEVELOPMENT 2020 JAN 1; 34(1-2):7-23
53BP1 is an enigmatic DNA damage response factor that gained prominence because it determines the efficacy of PARP1 inhibitory drugs (PARPi) in BRCA1-deficient cancers. Recent studies have elevated 53BP1 from its modest status of (yet another) DNA damage factor to master regulator of double-strand break (DSB) repair pathway choice. Our review of the literature suggests an alternative view. We propose that 53BP1 has evolved to avoid mutagenic repair outcomes and does so by controlling the processing of DNA ends and the dynamics of DSBs. The consequences of 53BP1 deficiency, such as diminished PARPi efficacy in BRCA1-deficient cells and altered repair of damaged telomeres, can be explained from this viewpoint. We further propose that some of the fidelity functions of 53BP1 coevolved with class switch recombination (CSR) in the immune system. We speculate that, rather than being deterministic in DSB repair pathway choice, 53BP1 functions as a DSB escort that guards against illegitimate and potentially tumorigenic recombination.
Baumann S, Ozdemir GH, Tesche C, Schoepf UJ, Golden JW, Becher T, Hirt M, Weiss C, Renker M, Akin I, Schoenberg SO, Borggrefe M, Haubenreisser H, Lossnitzer D, Overhoff D
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Coronary CT angiography derived plaque markers correlated with invasive instantaneous flow reserve for detecting hemodynamically significant coronary stenoses

EUROPEAN JOURNAL OF RADIOLOGY 2020 JAN; 122(?):? Article 108744
Purpose: The study aimed to compare morphological and anatomic plaque markers derived from coronary computed tomography angiography (cCTA) for the detection of lesion specific ischemia with invasive instantaneous wave free ratio (iFR (R)) as the reference standard. Methods: In our prospective study, we enrolled patients with suspected coronary artery disease (CAD), who had undergone cCTA, using a low-dose third-generation dual-source CT and invasive coronary angiography (ICA) with iFR (R) measurement. Various plaque markers were assessed on cCTA. Discriminatory power of these markers for the detection of ischemia-inducing coronary artery disease was evaluated against invasive iFR (R). Results: Our study cohort included 39 patients (66.6 +/- 12.0 years, 72 % male). Among 54 vessel-specific lesions, 15 lesions (28 %) were characterized as hemodynamically significant by iFR (R) <= 0.89. The area under the curve (AUC) of lesion length/ minimal luminal diameter(4) (LL/MLD4) (0.84) was greater than the AUC of minimal luminal area (MLA) (0.82), MLD (0.81), the degree of luminal diameter stenosis (0.81), corrected coronary opacification (CCO) (0.79), remodeling index (RI) (0.75), and percentage aggregate plaque volume (%APV) (0.72). LL, vessel volume (VV), total plaque volume (TPV), calcified and non-calcified plaque volume (CPV and NCPV) did not reach statistical significance and were unable to discriminate between vessels with and without ischemia-inducing coronary stenosis. Conclusion: LL/MLD4, MLA, MLD, the degree of luminal diameter stenosis, CCO, RI, and %APV derived from cCTA can support the detection of hemodynamically significant coronary stenosis as compared with iFR (R), with LL/MLD4 showing the greatest discriminatory power.
Maternal consumption of ethanol during pregnancy is known to increase the offspring's risk for developing alcohol use disorders and associated behavioral disturbances. Studies in adolescent and adult animals suggest the involvement of neuroimmune and neurochemical systems in the brain that control these behaviors. To understand the origin of these effects during early developmental stages, we examined in the embryo and neonate the effects of maternal intraoral administration of ethanol (2 g/kg/day) from embryonic day 10 (E10) to E15 on the inflammatory chemokine C-C motif ligand 2 (CCL2) and its receptor CCR2 in a specific, dense population of neurons in the lateral hypothalamus (LH), where they are closely related to an orexigenic neuropeptide, melanin-concentrating hormone (MCH), known to promote ethanol consumption and related behaviors. We found that prenatal ethanol exposure increases the expression and density of CCL2 and CCR2 cells along with MCH neurons in the LH and the colocalization of CCL2 with MCH. We also discovered that these effects are sexually dimorphic, consistently stronger in female embryos, and are blocked by maternal administration of a CCL2 antibody (1 and 5 mu g/day, i.p., E10-E15) that neutralizes endogenous CCL2 and of a CCR2 antagonist INCB3344 (1 mg/day, i.p., E10-E15) that blocks CCL2's main receptor. These results, which in the embryo anatomically and functionally link the CCL2/CCR2 system to MCH neurons in the LH, suggest an important role for this neuroimmune system in mediating ethanol's sexually dimorphic, stimulatory effect on MCH neurons that may promote higher level of alcohol consumption described in females. Published by Elsevier Ltd on behalf of IBRO.
Ali AA, Seng EK, Alavi A, Lowes MA
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Exploring changes in placebo treatment arms in hidradenitis suppurativa randomized clinical trials: A systematic review

Background: Hidradenitis suppurativa (HS) is characterized by recurrent, painful nodules in flexural areas. Objective: The objective of this study was to explore the placebo response in HS randomized clinical trials and to compare it briefly with the placebo response in psoriasis and atopic dermatitis. Methods: A Cochrane Review on interventions in HS was used as a starting point, and a systematic review was then undertaken by using the PubMed database, yielding 7 HS randomized clinical trials for inclusion in this study. Results: This review demonstrates that there is a robust placebo response in HS that is most marked in physical signs but also marked in pain responses. Limitations: Multiple outcome measures utilized in these studies and reporting bias limited this review. Conclusion: This large placebo response has implications for clinical trial design. This knowledge can also help deliver improved clinical care by forming the basis of nonpharmacologic treatments and help optimize current medication use to maximize the placebo effect.
McEwen BS, Akil H
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Revisiting the Stress Concept: Implications for Affective Disorders

Over the last 50 years, the concept of stress has evolved significantly, and our understanding of the underlying neurobiology has expanded dramatically. Rather than consider stress biology to be relevant only under unusual and threatening conditions, we conceive of it as an ongoing, adaptive process of assessing the environment, coping with it, and enabling the individual to anticipate and deal with future challenges. Though much remains to be discovered, the fundamental neurocircuitry that underlies these processes has been broadly delineated, key molecular players have been identified, and the impact of this system on neuroplasticity has been well established. More recently, we have come to appreciate the critical interaction between the brain and the rest of the body as it pertains to stress responsiveness. Importantly, this system can become overloaded due to ongoing environmental demands on the individual, be they physical, physiological, or psychosocial. The impact of this overload is deleterious to brain health, and it results in vulnerability to a range of brain disorders, including major depression and cognitive deficits. Thus, stress biology is one of the best understood systems in affective neuroscience and is an ideal target for addressing the pathophysiology of many brain-related diseases. The story we present began with the discovery of glucocorticoid receptors in hippocampus and has extended to other brain regions in both animal models and the human brain with the further discovery of structural and functional adaptive plasticity in response to stressful and other experiences.