Clustered nuclei maintain autonomy and nucleocytoplasmic ratio control in a syncytium

© The Author(s), 2016. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Molecular Biology of the Cell 27 (2016): 2000-2007, doi:10.1091/mbc.E16-02-0129.Nuclei in syncytia found in fungi, muscles, and tumors can behave independently despite cytoplasmic translation and the homogenizing potential of diffusion. We use a dynactin mutant strain of the multinucleate fungus Ashbya gossypii with highly clustered nuclei to assess the relative contributions of nucleus and cytoplasm to nuclear autonomy. Remarkably, clustered nuclei maintain cell cycle and transcriptional autonomy; therefore some sources of nuclear independence function even with minimal cytosol insulating nuclei. In both nuclear clusters and among evenly spaced nuclei, a nucleus’ transcriptional activity dictates local cytoplasmic contents, as assessed by the localization of several cyclin mRNAs. Thus nuclear activity is a central determinant of the local cytoplasm in syncytia. Of note, we found that the number of nuclei per unit cytoplasm was identical in the mutant to that in wild-type cells, despite clustered nuclei. This work demonstrates that nuclei maintain autonomy at a submicrometer scale and simultaneously maintain a normal nucleocytoplasmic ratio across a syncytium up to the centimeter scale.his work was supported by National Institutes of Health R01-GM081506 (A.S.G., S.E.R., and P.O.), the National Science Foundation GK-12 Program and the Neukom Institute at Dartmouth College (S.E.R.), the Alfred P. Sloan Foundation and National Science Foundation DMS-1351860 (M.R. and S.-S.C.), a National Institutes of Health Ruth L. Kirschstein National Research Service Award (T32-GM008185; S.-S.C.), and the Intramural Research Programs of the National Institutes of Health National Institute of Biomedical Imaging and Bioengineering Whitman Investigator and Grass Foundation Programs at the Marine Biological Laboratory at Woods Hole (A.K. and H.S.

Examining the Overlap Between ADHD and Autism Spectrum Disorder (ASD) Using Candidate Endophenotypes of ADHD

Objective: Recent discussions of aetiological overlap between ADHD and Autism Spectrum Disorder (ASD) require comparative studying of these disorders. Method: We examined performance of ASD patients with (ASD+) and without (ASD-) comorbid ADHD, ADHD patients, and controls for selected putative endophenotypes of ADHD: Intrasubject Variability (ISV) of reaction times, working memory (WM), inhibition, and temporal processing. Results: We found that patients with ADHD or ASD+, but not ASD-, had elevated ISV across the entire task battery and temporal processing deficits, and that none of the groups were impaired in WM or inhibition. High levels of ISV and generally poor performance in ASD+ patients were only partially due to additive effects of the pure disorders. Conclusion: Overall, we conclude that, within our limited but heterogeneous task battery, ISV and temporal processing deficits are most sensitive to ADHD symptomatology and that controlling for ADHD comorbidity is mandatory when assessing ISV in autism

Assessment of atrial septal defects in adults comparing cardiovascular magnetic resonance with transoesophageal echocardiography

BackgroundMany adult patients with secundum-type atrial septal defects (ASDs) are able to have these defects fixed percutaneously. Traditionally, this has involved an assessment of ASD size, geometry and atrial septal margins by transoesophageal echocardiography (TOE) prior to percutaneous closure. This is a semi-invasive technique, and all of the information obtained could potentially be obtained by non-invasive cardiovascular magnetic resonance (CMR). We compared the assessment of ASDs in consecutive patients being considered for percutaneous ASD closure using CMR and TOE.MethodsConsecutive patients with ASDs diagnosed on transthoracic echocardiography (TTE) were invited to undergo both CMR and TOE. Assessment of atrial septal margins, maximal and minimal defect dimensions was performed with both techniques. Analyses between CMR and TOE were made using simple linear regression and Bland Altman Analyses.ResultsTotal CMR scan time was 20 minutes, and comparable to the TOE examination time. A total of 20 patients (M:F = 5:15, mean age 42.8 years +/- 15.7) were included in the analyses. There was an excellent agreement between CMR and TOE for estimation of maximum defect size (R = 0.87). The anterior inferior, anterior superior and posterior inferior margins could be assessed in all patients with CMR. The posterior superior margin could not be assessed in only one patient. Furthermore, in 1 patient in whom TOE was unable to be performed, CMR was used to successfully direct percutaneous ASD closure.ConclusionsCMR agrees with TOE assessment of ASDs in the work-up for percutaneous closure. Potentially CMR could be used instead of TOE for this purpose.Karen S.L. Teo, Patrick J. Disney, Benjamin K. Dundon, Matthew I. Worthley, Michael A. Brown, Prashanthan Sanders and Stephen G. Worthle

The deleterious effects of arteriovenous fistula-creation on the cardiovascular system: a longitudinal magnetic resonance imaging study

AIM: Arteriovenous fistula-formation remains critical for the provision of hemodialysis in end-stage renal failure patients. Its creation results in a significant increase in cardiac output, with resultant alterations in cardiac stroke volume, systemic blood flow, and vascular resistance. The impact of fistula-formation on cardiac and vascular structure and function has not yet been evaluated via "gold standard" imaging techniques in the modern era of end-stage renal failure care. METHODS: A total of 24 patients with stage 5 chronic kidney disease undergoing fistula-creation were studied in a single-arm pilot study. Cardiovascular magnetic resonance imaging was undertaken at baseline, and prior to and 6 months following fistula-creation. This gold standard imaging modality was used to evaluate, via standard brachial flow-mediated techniques, cardiac structure and function, aortic distensibility, and endothelial function. RESULTS: At follow up, left ventricular ejection fraction remained unchanged, while mean cardiac output increased by 25.0% (P<0.0001). Significant increases in left and right ventricular end-systolic volumes (21% [P=0.014] and 18% [P<0.01]), left and right atrial area (11% [P<0.01] and 9% [P<0.01]), and left ventricular mass were observed (12.7% increase) (P<0.01). Endothelial-dependent vasodilation was significantly decreased at follow up (9.0%±9% vs 3.0%±6%) (P=0.01). No significant change in aortic distensibility was identified. CONCLUSION: In patients with end-stage renal failure, fistula-formation is associated with an increase in cardiac output, dilation of all cardiac chambers and deterioration in endothelial function.Benjamin K Dundon, Kim Torpey, A dam J Nelson, Dennis TL Wong, Rae F Duncan, Ian T Meredith, Randall J Faull, S tephen G Worthley, Matthew I Worthle

FXR1 splicing is important for muscle development and biomolecular condensates in muscle cells

© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Smith, J. A., Curry, E. G., Blue, R. E., Roden, C., Dundon, S. E. R., Rodríguez-Vargas, A., Jordan, D. C., Chen, X., Lyons, S. M., Crutchley, J., Anderson, P., Horb, M. E., Gladfelter, A. S., & Giudice, J. FXR1 splicing is important for muscle development and biomolecular condensates in muscle cells. Journal of Cell Biology, 219(4), (2020): e201911129, doi: 10.1083/jcb.201911129.Fragile-X mental retardation autosomal homologue-1 (FXR1) is a muscle-enriched RNA-binding protein. FXR1 depletion is perinatally lethal in mice, Xenopus, and zebrafish; however, the mechanisms driving these phenotypes remain unclear. The FXR1 gene undergoes alternative splicing, producing multiple protein isoforms and mis-splicing has been implicated in disease. Furthermore, mutations that cause frameshifts in muscle-specific isoforms result in congenital multi-minicore myopathy. We observed that FXR1 alternative splicing is pronounced in the serine- and arginine-rich intrinsically disordered domain; these domains are known to promote biomolecular condensation. Here, we show that tissue-specific splicing of fxr1 is required for Xenopus development and alters the disordered domain of FXR1. FXR1 isoforms vary in the formation of RNA-dependent biomolecular condensates in cells and in vitro. This work shows that regulation of tissue-specific splicing can influence FXR1 condensates in muscle development and how mis-splicing promotes disease.We thank the A.S. Gladfelter and J. Giudice laboratories, Nancy Kedersha, and Silvia Ramos for critical discussions; Eunice Y. Lee for technical help; Dr. Stephanie Gupton (University of North Carolina at Chapel Hill, Chapel Hill, NC) for donation of WT C57BL/6J mouse embryos; and Marcin Wlizla and National Xenopus Resource (RRID:SCR_013731) for their help in maintaining adult frogs and other important technical support. This work has been funded by a University of North Carolina at Chapel Hill Junior Faculty Development Award (to J. Giudice); a Nutrition and Obesity Research Center, University of North Carolina at Chapel Hill, Pilot & Feasibility Research grant (P30DK056350 to J. Giudice); University of North Carolina at Chapel Hill startup funds (to J. Giudice); the March of Dimes Foundation (5-FY18-36, Basil O’Connor Starter Scholar Award to J. Giudice); and NCTraCs Pilot Grant (550KR181805) from the National Center for Advancing Translational Sciences (NCATS), National Institutes of Health, through Grant Award Number UL1TR002489 (to J. Giudice), National Institutes of Health National Institute of General Medical Sciences grants (R01-GM130866 to J. Giudice, R01-GM081506 to A.S. Gladfelter, R35-GM126901 to P. Anderson, K99-GM124458 to S.M. Lyons, R25-GM089569 and 2R25-GM055336-20 to E.G. Curry); Howard Hughes Medical Institute Faculty Scholars program (A.S. Gladfelter), and National Institute of Health grants R01-HD084409 and P40-OD010997 (to M.E. Horb). The content is solely the responsibility of the authors and does not necessarily represent the official views of the funding agencies.2020-09-1

A case of eosinophilic granuloma of the skull in an adult man: a case report

Eosinophilic granuloma is very rare benign bone tumor which presents in more than 90% in children under the age of ten. There is predominance for males. It is usually found at flat and long bones. The skull and vertebral spine is often affected. We report a case of 57 year-old man who gradually developed local pain at his skull and orbit. A soft, movable, palpable and tender mass was found at the left temporal bone. The pain deteriorated after an accidental injury at skull and remained so. The clinical examination revealed no pathological findings. The patient was a doctor who smoked and consumed alcohol daily. He had a history of cardial infraction and psoriatic arthritis. X-rays and CT revealed a round lytic defect at the skull. Its borders were sharp and its size was 1.6 × 1.8 cm. No periostic reaction or bone formation was noted. Scintigraphy depicted a lytic lesion without radionuclide enhancement. Thus we suspected an eosinophilic granuloma. An attempt to excise the tumor failed as it had already eroded the underlying temporal bone. The external meninga was affected but not the internal one. Histological diagnosis with dominance of Langerhans cells set the diagnosis. A second surgery was done and the eosinophilic granuloma was extracted. After eight months the gap was bridged with plastic heterologous transplant. After the curettage the patient received antibiotics and five cycles of radiotherapy. The aesthetic result was excellent. The patient's head has a normal hairy appearance. No tenderness, swelling or recurrence is recorded until now

A Novel Peptide ELISA for Universal Detection of Antibodies to Human H5N1 Influenza Viruses

BACKGROUND: Active serologic surveillance of H5N1 highly pathogenic avian influenza (HPAI) virus in humans and poultry is critical to control this disease. However, the need for a robust, sensitive and specific serologic test for the rapid detection of antibodies to H5N1 viruses has not been met. METHODOLOGY/PRINCIPAL FINDINGS: Previously, we reported a universal epitope (CNTKCQTP) in H5 hemagglutinin (HA) that is 100% conserved in H5N1 human isolates and 96.9% in avian isolates. Here, we describe a peptide ELISA to detect antibodies to H5N1 virus by using synthetic peptide that comprises the amino acid sequence of this highly conserved and antigenic epitope as the capture antigen. The sensitivity and specificity of the peptide ELISA were evaluated using experimental chicken antisera to H5N1 viruses from divergent clades and other subtype influenza viruses, as well as human serum samples from patients infected with H5N1 or seasonal influenza viruses. The peptide ELISA results were compared with hemagglutinin inhibition (HI), and immunofluorescence assay and immunodot blot that utilize recombinant HA1 as the capture antigen. The peptide ELISA detected antibodies to H5N1 in immunized animals or convalescent human sera whereas some degree of cross-reactivity was observed in HI, immunofluorescence assay and immunodot blot. Antibodies to other influenza subtypes tested negative in the peptide-ELISA. CONCLUSION/SIGNIFICANCE: The peptide-ELISA based on the highly conserved and antigenic H5 epitope (CNTKCQTP) provides sensitive and highly specific detection of antibodies to H5N1 influenza viruses. This study highlighted the use of synthetic peptide as a capture antigen in rapid detection of antibodies to H5N1 in human and animal sera that is robust, simple and cost effective and is particularly beneficial for developing countries and rural areas

Helicobacter pylori Induces Activation of Human Peripheral γδ+ T Lymphocytes

Helicobacter pylori is a Gram-negative bacterium that causes gastric and duodenal diseases in humans. Despite a robust antibody and cellular immune response, H. pylori infection persists chronically. To understand if and how H. pylori could modulate T cell activation, in the present study we investigated in vitro the interaction between H. pylori and human T lymphocytes freshly isolated from peripheral blood of H. pylori-negative donors. A direct interaction of live, but not killed bacteria with purified CD3+ T lymphocytes was observed by microscopy and confirmed by flow cytometry. Live H. pylori activated CD3+ T lymphocytes and predominantly γδ+ T cells bearing the TCR chain Vδ2. Upon interaction with H. pylori, these cells up-regulated the activation molecule CD69 and produced cytokines (such as TNFα, IFNγ) and chemokines (such as MIP-1β, RANTES) in a non-antigen-specific manner. This activation required viable H. pylori and was not exhibited by other Gram-negative bacteria. The cytotoxin-associated antigen-A (CagA), was at least partially responsible of this activation. Our results suggest that H. pylori can directly interact with T cells and modulate the response of γδ+ T cells, thereby favouring an inflammatory environment which can contribute to the chronic persistence of the bacteria and eventually to the gastric pathology