Characterization of the 8-hydroxyquinoline scaffold for inhibitors of West Nile virus serine protease

West Nile virus (WNV) is a mosquito-borne member of flaviviruses that causes significant morbidity and mortality especially among children. There is currently no approved vaccine or antiviral therapeutic for human use. In a previous study, we described compounds containing the 8-hydroxyquinoline (8-HQ) scaffold as inhibitors of WNV serine protease (NS2B/NS3pro) in a high throughput screen (HTS) using the purified WNV NS2B/NS3pro as the target. In this study, we analyzed potencies of some commercially available as well as chemically synthesized derivatives of 8-HQ by biochemical assays. An insight into the contribution of various substitutions of 8-HQ moiety for inhibition of the protease activity was revealed. Most importantly, the substitution of the N1 of the 8-HQ ring by –CH– in compound 26 significantly reduced the inhibition of the viral protease by this naphthalen-1-ol derivative. The kinetic constant (Ki) for the most potent 8-HQ inhibitor (compound 14) with an IC50 value of 2.01 ± 0.08 ?M using the tetra-peptide substrate was determined to be 5.8 ?M. This compound inhibits the WNV NS2B/NS3pro by a competitive mode of inhibition which is supported by molecular modeling

Sulfatide Preserves Insulin Crystals Not by Being Integrated in the Lattice but by Stabilizing Their Surface

Background. Sulfatide is known to chaperone insulin crystallization within the pancreatic beta cell, but it is not known if this results from sulfatide being integrated inside the crystal structure or by binding the surface of the crystal. With this study, we aimed to characterize the molecular mechanisms underlying the integral role for sulfatide in stabilizing insulin crystals prior to exocytosis. Methods. We cocrystallized human insulin in the presence of sulfatide and solved the structure by molecular replacement. Results. The crystal structure of insulin crystallized in the presence of sulfatide does not reveal ordered occupancy representing sulfatide in the crystal lattice, suggesting that sulfatide does not permeate the crystal lattice but exerts its stabilizing effect by alternative interactions such as on the external surface of insulin crystals. Conclusions. Sulfatide is known to stabilize insulin crystals, and we demonstrate here that in beta cells sulfatide is likely coating insulin crystals. However, there is no evidence for sulfatide to be built into the crystal lattice

Risk factors for youth violence: Youth violence commission, International Society For Research On Aggression (ISRA)

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/144599/1/ab21766.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/144599/2/ab21766_am.pd

Gemini/GMOS Imaging of Globular Cluster Systems in Five Early-type Galaxies

This paper presents deep high quality photometry of globular cluster (GC) systems belonging to five early-type galaxies covering a range of mass and environment. Photometric data were obtained with the Gemini North and Gemini South telescopes in the filter passbands g', r', and i'. The combination of these filters with good seeing conditions allows an excellent separation between GC candidates and unresolved field objects. Bimodal GC colour distributions are found in all five galaxies. Most of the GC systems appear bimodal even in the (g' -r') vs (r' -i') plane. A population of resolved/marginally resolved GC and Ultra Compact Dwarf candidates was found in all the galaxies. A search for the so-called "blue tilt" in the colour-magnitude diagrams reveals that NGC 4649 clearly shows that phenomenon although no conclusive evidence was found for the other galaxies in the sample. This "blue tilt" translates into a mass-metallicity relation given by Z \propto M^0.28\pm0.03 . This dependence was found using a new empirical (g' -i') vs [Z/H] relation which relies on an homogeneous sample of GC colours and metallicities. This paper also explores the radial trends in both colour and surface density for the blue (metal-poor) and red (metal-rich) GC subpopulations. As usual, the red GCs show a steeper radial distribution than the blue ones. Evidence of galactocentric colour gradients is found in some of the GC systems, being more significant for the two S0 galaxies in the sample. Red GC subpopulations show similar colours and gradients to the galaxy halo stars in their inner region. A GC mean colour-galaxy luminosity relation, consistent with [Z/H] \propto L_B ^0.26\pm0.08, is present for the red GCs. An estimate of the total GC populations and specific frequency SN values is presented for NGC 3115, NGC 3379, NGC 3923 and NGC 4649.Comment: 23 pages, 13 figures and 9 tables. Tables A1 and A2 will be published in full online only. Accepted for publication in MNRA

Role of Proinsulin Self-Association in Mutant INS Gene–Induced Diabetes of Youth

Abnormal interactions between misfolded mutant and wild-type (WT) proinsulin (PI) in the endoplasmic reticulum (ER) drive the molecular pathogenesis of mutant INS gene-induced diabetes of youth (MIDY). How these abnormal interactions are initiated remains unknown. Normally, PI-WT dimerizes in the ER. Here, we suggest that the normal PI-PI contact surface, involving the B-chain, contributes to dominant-negative effects of misfolded MIDY mutants. Specifically, we find that PI B-chain tyrosine-16 (Tyr-B16), which is a key residue in normal PI dimerization, helps confer dominant-negative behavior of MIDY mutant PI-C(A7)Y. Substitutions of Tyr-B16 with either Ala, Asp, or Pro in PI-C(A7)Y decrease the abnormal interactions between the MIDY mutant and PI-WT, rescuing PI-WT export, limiting ER stress, and increasing insulin production in β-cells and human islets. This study reveals the first evidence indicating that noncovalent PI-PI contact initiates dominant-negative behavior of misfolded PI, pointing to a novel therapeutic target to enhance PI-WT export and increase insulin production

HLA-B*14:01 and HLA-B*35:01 are associated with trimethoprim-sulfamethoxazole induced liver injury

Background and AimTrimethoprim‐sulfamethoxazole (TMP‐SMX) is an important cause of idiosyncratic drug induced liver injury (DILI), but its genetic risk factors are not well understood. We investigated the relationship between variants in the HLA Class I and II genes and well characterized cases of TMP‐SMX DILI.MethodsEuropean American and African American persons with TMP‐SMX DILI were compared to respective population controls. HLA sequencing was performed by Illumina MiSeq for cases. HLA genotype imputation with attribute bagging (HIBAG) program was used to impute HLA alleles for controls. Allele frequency difference between cases and controls was tested by Fisher exact tests per ethnic group. For European Americans, multivariable logistic regression with Firth penalization was used to test HLA allelic effect after adjusting for age and the top two principal components. Molecular docking was performed to assess the HLA binding with TMP and SMX.ResultsThe European American subset had 51 cases and 12,156 controls, while the African American subset had 10 cases and 5,439 controls. Four HLA alleles were significantly associated in the European American subset, with HLA‐B*14:01 ranking at the top (OR: 9.20, 95% CI: 3.16‐22.35, p=0.0003) after covariate adjustment. All HLA‐B*14:01 carriers with TMP‐SMX DILI possessed HLA‐C*08:02, another significant allele (p=0.0026). This pattern was supported by HLA‐B*14:01‐HLA‐C*08:02 haplotype association (p=1.33x10‐5). For the African Americans, HLA‐B*35:01 had 2.8‐fold higher frequency in cases than in controls, with five of 10 patients carrying this allele. Molecular docking showed Cys67 in HLA‐B*14:01 and Phe67 in HLA‐B*35:01 to be the predictive binding sites to SMX metabolites. ConclusionHLA‐B*14:01 is associated with TMP‐SMX DILI in European Americans, and HLA‐B*35:01 may be a potential genetic risk factor for African Americans

Functional Expression of Human Adenine Nucleotide Translocase 4 in Saccharomyces Cerevisiae

The adenine nucleotide translocase (ANT) mediates the exchange of ADP and ATP across the inner mitochondrial membrane. The human genome encodes multiple ANT isoforms that are expressed in a tissue-specific manner. Recently a novel germ cell-specific member of the ANT family, ANT4 (SLC25A31) was identified. Although it is known that targeted depletion of ANT4 in mice resulted in male infertility, the functional biochemical differences between ANT4 and other somatic ANT isoforms remain undetermined. To gain insight into ANT4, we expressed human ANT4 (hANT4) in yeast mitochondria. Unlike the somatic ANT proteins, expression of hANT4 failed to complement an AAC-deficient yeast strain for growth on media requiring mitochondrial respiration. Moreover, overexpression of hANT4 from a multi-copy plasmid interfered with optimal yeast growth. However, mutation of specific amino acids of hANT4 improved yeast mitochondrial expression and supported growth of the AAC-deficient yeast on non-fermentable carbon sources. The mutations affected amino acids predicted to interact with phospholipids, suggesting the importance of lipid interactions for function of this protein. Each mutant hANT4 and the somatic hANTs exhibited similar ADP/ATP exchange kinetics. These data define common and distinct biochemical characteristics of ANT4 in comparison to ANT1, 2 and 3 providing a basis for study of its unique adaptation to germ cells

CD4+ regulatory T cells require CTLA-4 for the maintenance of systemic tolerance

Cytotoxic T lymphocyte antigen-4 (CTLA-4) plays a critical role in negatively regulating T cell responses and has also been implicated in the development and function of natural FOXP3+ regulatory T cells. CTLA-4–deficient mice develop fatal, early onset lymphoproliferative disease. However, chimeric mice containing both CTLA-4–deficient and –sufficient bone marrow (BM)–derived cells do not develop disease, indicating that CTLA-4 can act in trans to maintain T cell self-tolerance. Using genetically mixed blastocyst and BM chimaeras as well as in vivo T cell transfer systems, we demonstrate that in vivo regulation of Ctla4−/− T cells in trans by CTLA-4–sufficient T cells is a reversible process that requires the persistent presence of FOXP3+ regulatory T cells with a diverse TCR repertoire. Based on gene expression studies, the regulatory T cells do not appear to act directly on T cells, suggesting they may instead modulate the stimulatory activities of antigen-presenting cells. These results demonstrate that CTLA-4 is absolutely required for FOXP3+ regulatory T cell function in vivo

Updates in SJS/TEN: collaboration, innovation, and community

Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis (SJS/TEN) is a predominantly drug-induced disease, with a mortality rate of 15–20%, that engages the expertise of multiple disciplines: dermatology, allergy, immunology, clinical pharmacology, burn surgery, ophthalmology, urogynecology, and psychiatry. SJS/TEN has an incidence of 1–5/million persons per year in the United States, with even higher rates globally. One of the challenges of SJS/TEN has been developing the research infrastructure and coordination to answer questions capable of transforming clinical care and leading to improved patient outcomes. SJS/TEN 2021, the third research meeting of its kind, was held as a virtual meeting on August 28–29, 2021. The meeting brought together 428 international scientists, in addition to a community of 140 SJS/TEN survivors and family members. The goal of the meeting was to brainstorm strategies to support the continued growth of an international SJS/TEN research network, bridging science and the community. The community workshop section of the meeting focused on eight primary themes: mental health, eye care, SJS/TEN in children, non-drug induced SJS/TEN, long-term health complications, new advances in mechanisms and basic science, managing long-term scarring, considerations for skin of color, and COVID-19 vaccines. The meeting featured several important updates and identified areas of unmet research and clinical need that will be highlighted in this white paper