Transplantation of Wild-Type Hematopoietic Stem and Progenitor Cells Improves Disease Phenotypes in a Mucopolysaccharidosis IIIC Mouse Model.

Mucopolysaccharidosis type IIIC (MPS IIIC) is a severe neurodegenerative lysosomal storage disease caused by the loss-of-function of the lysosomal transmembrane protein acetyl-CoA: heparan-α-glucosamine N-acetyltransferase. MPS IIIC is characterized by the accumulation of the glycosaminoglycan (GAG) heparan sulfate. There is no treatment for this disease. We generated a new MPS IIIC mouse model and confirmed disease phenotypes such as GAG accumulation, splenomegaly, neurological defects, and presence of disease-specific non-reducing end carbohydrates. To explore a new therapeutic strategy for this condition, we transplanted wild-type (WT) hematopoietic stem and progenitor cells (HSPCs) into lethally irradiated 2-month-old Hgsnat-/- mice and analyzed the resulting impact 6 months later. Transplanted HSPCs differentiated into macrophages in tissues and microglia-like cells in the brain. This resulted in a partial restoration of Hgsnat expression and enzymatic activity along with a significant reduction of the MPS IIIC-specific non-reducing end carbohydrate in the treated Hgsnat-/- mice compared to untreated Hgsnat-/- mice or Hgsnat-/- mice transplanted with Hgsnat-/- HPSCs. In addition, WT HSPC transplant resulted in improved neurological defects, reduction in splenomegaly, and urine retention in the Hgsnat-/- mice. Furthermore, presence of glomerular hyaline bodies with focal fibrosis and sclerosis was observed in the kidney of the disease controls, whereas these abnormalities were improved in the Hgsnat-/- mice treated with WT HSPCs. These data support that HSPC transplantation presents a promising therapeutic avenue for MPS IIIC and represents the first step toward the clinical translation of an HSPC-mediated therapy strategy for MPS IIIC

DNA methylation among firefighters

Firefighters are exposed to carcinogens and have elevated cancer rates. We hypothesized that occupational exposures in firefighters would lead to DNA methylation changes associated with activation of cancer pathways and increased cancer risk. To address this hypothesis, we collected peripheral blood samples from 45 incumbent and 41 new recruit nonsmoking male firefighters and analyzed the samples for DNA methylation using an Illumina Methylation EPIC 850k chip. Adjusting for age and ethnicity, we performed: 1) genome-wide differential methylation analysis; 2) genome-wide prediction for firefighter status (incumbent or new recruit) and years of service; and 3) Ingenuity Pathway Analysis (IPA). Four CpGs, including three in the YIPF6, MPST, and PCED1B genes, demonstrated above 1.5-fold statistically significant differential methylation after Bonferroni correction. Genome-wide methylation predicted with high accuracy incumbent and new recruit status as well as years of service among incumbent firefighters. Using IPA, the top pathways with more than 5 gene members annotated from differentially methylated probes included Sirtuin signaling pathway, p53 signaling, and 5' AMP-activated protein kinase (AMPK) signaling. These DNA methylation findings suggest potential cellular mechanisms associated with increased cancer risk in firefighters.US Federal Emergency Management Agency Assistance to Firefighters Grant program [EMW-2014-FP-00200]Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Sanger Confirmation Is Required to Achieve Optimal Sensitivity and Specificity in Next-Generation Sequencing Panel Testing

Next-generation sequencing (NGS) has rapidly replaced Sanger sequencing as the method of choice for diagnostic gene-panel testing. For hereditary-cancer testing, the technical sensitivity and specificity of the assay are paramount as clinicians use results to make important clinical management and treatment decisions. There is significant debate within the diagnostics community regarding the necessity of confirming NGS variant calls by Sanger sequencing, considering that numerous laboratories report having 100% specificity from the NGS data alone. Here we report our results from 20,000 hereditary-cancer NGS panels spanning 47 genes, in which all 7845 nonpolymorphic variants were Sanger- sequenced. Of these, 98.7% were concordant between NGS and Sanger sequencing and 1.3% were identified as NGS false-positives, located mainly in complex genomic regions (A/T-rich regions, G/C-rich regions, homopolymer stretches, and pseudogene regions). Simulating a false-positive rate of zero by adjusting the variant-calling quality-score thresholds decreased the sensitivity of the assay from 100% to 97.8%, resulting in the missed detection of 176 Sanger-confirmed variants, the majority in complex genomic regions (n = 114) and mosaic mutations (n = 7). The data illustrate the importance of setting quality thresholds for panel testing only after thousands of samples have been processed and the necessity of Sanger confirmation of NGS variants to maintain the highest possible sensitivity

Calcineurin Aβ signalling is required for Treg-cell generation and prevention of T-cell activation and B-cell lymphomagenesis (100.13)

Abstract Introduction: Calcineurin (CN), a protein phosphatase activated by Ca2+-calmodulin, is involved in activation of NFAT. CN inhibitors such as cyclosporine A (CsA) and FK506 are potent inhibitors of T-cell responses and are commonly used to prevent graft rejection. Consistently, CNAβ-deficient mice exhibit defective thymocyte maturation in young mice. However, T cells undergo spontaneous activation in older Cnab-/- mice, and succumb to B-cell lymphomas. Methods: Splenocytes are cultured in the presence of anti-CD3/CD28 beads, TGFβ1 and IL-2 for 3 days. Cytokines in culture supernatants are determined by ELISA, CBA and MSD methods. Cells are stained with CD4, CD25, CD62L and intracellular FOXP3. Results: We observed that FOXP3+ Treg cells are decreased while mature activated T cells (CD62L-CD44+) are increased in KO mice compared to control mice. While TGFβ1 induced the expression of FOXP3 in WT cultures, it failed to induce FOXP3 in KO cultures. Cytokine profiles revealed that CNAβ is required to inhibit IL-4, IL-6, IL-10, IL-17 and IFNγ by TGFβ1. IHC analyses of lymphomas revealed that the lymphomas are of B cell origin and they do not express FOXP1, a marker for activated B cells (ABCs). Discussion: These data show that CNAβ is important for the development and homeostasis of mature T cells and Treg cells. The data also suggest that in the absence of CNAβ, a defective T-cell regulation results in activation of T cells, production of inflammatory cytokines and cause cancer.</jats:p

Tyrphostins. 5. Potent Inhibitors of Platelet-Derived Growth Factor Receptor Tyrosine Kinase: Structure−Activity Relationships in Quinoxalines, Quinolines, and Indole Tyrphostins

A series of 3-indoleacrylonitrile tyrphostins, 2-chloro-3-phenylquinolines, and 3-arylquinoxalines were prepared and tested for inhibition of platelet-derived growth factor receptor tyrosine kinase (PDGF-RTK) activity. The potency of the inhibitors was found to be quinoxalines > quinolines > indoles. Lipophilic groups (methyl, methoxy) in the 6 and 7 positions and phenyl at the 3 position of quinoxalines and quinolines were essential for potency, in contrast to the hydrophilic catechol group in tyrphostins active against EGFR kinase inhibition at different sites. The inhibitors showed selectivity for PDGF and were not active against EGF receptor and HER-2/c-ErbB-2 receptor

Towards high-performance p-type two-dimensional field effect transistors: contact engineering, scaling, and doping

Abstract N-type field effect transistors (FETs) based on two-dimensional (2D) transition metal dichalcogenides (TMDs) like MoS2 and WS2 have come closer to meeting the requirements set forth in International Roadmap for Devices and Systems (IRDS). However, p-type 2D FETs are dramatically lagging behind in meeting performance standards. Here, we adopt a three-pronged approach that includes contact engineering, channel length (Lch) scaling, and monolayer doping to achieve high-performance p-type FETs based on synthetic WSe2. Using electrical measurements backed by atomistic imaging and rigorous analysis, Pd was identified as the favorable contact metal for Wse2 owing to better epitaxy, larger grain size, and higher compressive strain leading to lower Schottky barrier height. While the ON-state performance of Pd-contacted WSe2 FETs was improved by ~10× by aggressively scaling Lch from 1 µm down to ~ 20 nm, ultra-scaled FETs were found to be contact limited. To reduce the contact resistance, monolayer tungsten oxyselenide (WOxSey) obtained using self-limiting oxidation of bilayer WSe2 was used as p-type dopant. This led to ~ 5× improvement in the ON-state performance and ~ 9× reduction in the contact resistance. We were able to achieve a median ON-state current as high as ~ 10 µA/µm for ultra-scaled and doped p-type WSe2 FETs with Pd contacts. We also show the applicability of our monolayer doping strategy to other 2D materials, like MoS2, MoTe2, and MoSe2.</jats:p