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Found 37769 matches. Displaying 1801-1810
Kennel PJ, Yahi A, Naka Y, Mancini DM, Marboe CC, Max K, Akat K, Tuschl T, Vasilescu ERM, Zorn E, Tatonetti NP, Schulze PC
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Longitudinal profiling of circulating miRNA during cardiac allograft rejection: a proof-of-concept study

ESC HEART FAILURE 2021; ?(?):?
Aims Allograft rejection following heart transplantation (HTx) is a serious complication even in the era of modern immunosuppressive regimens and causes up to a third of early deaths after HTx. Allograft rejection is mediated by a cascade of immune mechanisms leading to acute cellular rejection (ACR) and/or antibody-mediated rejection (AMR). The gold standard for monitoring allograft rejection is invasive endomyocardial biopsy that exposes patients to complications. Little is known about the potential of circulating miRNAs as biomarkers to detect cardiac allograft rejection. We here present a systematic analysis of circulating miRNAs as biomarkers and predictors for allograft rejection after HTx using next-generation small RNA sequencing. Methods and results We used next-generation small RNA sequencing to investigate circulating miRNAs among HTx recipients (10 healthy controls, 10 heart failure patients, 13 ACR, and 10 AMR). MiRNA profiling was performed at different time points before, during, and after resolution of the rejection episode. We found three miRNAs with significantly increased serum levels in patients with biopsy-proven cardiac rejection when compared with patients without rejection: hsa-miR-139-5p, hsa-miR-151a-5p, and hsa-miR-186-5p. We identified miRNAs that may serve as potential predictors for the subsequent development of ACR: hsa-miR-29c-3p (ACR) and hsa-miR-486-5p (AMR). Overall, hsa-miR-486-5p was most strongly associated with acute rejection episodes. Conclusions Monitoring cardiac allograft rejection using circulating miRNAs might represent an alternative strategy to invasive endomyocardial biopsy.
Wang ZJ, Lorenzi JCC, Muecksch F, Finkin S, Viant C, Gaebler C, Cipolla M, Hoffman HH, Oliveira TY, Oren DA, Ramos V, Nogueira L, Michailidis E, Robbiani DF, Gazumyan A, Rice CM, Hatziioannou T, Bieniasz PD, Caskey M, Nussenzweig MC
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Enhanced SARS-CoV-2 neutralization by dimeric IgA

SCIENCE TRANSLATIONAL MEDICINE 2021 JAN 20; 13(577):? Article eabf1555
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 (COVID-19), primarily infects cells at mucosal surfaces. Serum neutralizing antibody responses are variable and generally low in individuals that suffer mild forms of COVID-19. Although potent immunoglobulin G (IgG) antibodies can neutralize the virus, less is known about secretory antibodies such as IgA that might affect the initial viral spread and transmissibility from the mucosa. Here, we characterize the IgA response to SARS-CoV-2 in a cohort of 149 convalescent individuals after diagnosis with COVID-19. IgA responses in plasma generally correlated with IgG responses. Furthermore, clones of IgM-, IgG-, and IgA-producing B cells were derived from common progenitor cells. Plasma IgA monomers specific to SARS-CoV-2 proteins were demonstrated to be twofold less potent than IgG equivalents. However, IgA dimers, the primary form of antibody in the nasopharynx, were, on average, 15 times more potent than IgA monomers against the same target. Thus, dimeric IgA responses may be particularly valuable for protection against SARS-CoV-2 and for vaccine efficacy.
Freedenberg AT, Pan CH, Diehl WE, Romeiser JL, Hwang GR, Leiton CV, Muecksch F, Shroyer KR, Bennett-Guerrero E
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Neutralizing activity to SARS-CoV-2 of convalescent and control plasma used in a randomized controlled trial

TRANSFUSION 2021; ?(?):?
Background There are limited data on the neutralizing activity of convalescent plasma (CP) administered in randomized controlled trials (RCT) of COVID-19 infection. Study Design and Methods As part of an RCT, CP was collected per FDA guidelines from individuals recovered from COVID-19 infection. CP donors had to have >= 145 optical density (OD) units (ideal target >= 300) using a semiquantitative, immunochromatographic test for IgG antibody to the nucleocapsid protein (NP) of SARS-CoV-2 (typical range 0-500 OD units). A random subset of samples [14 control plasma, 12 CP "medium-anti-NP" (145-299 OD units), and 13 CP "high" anti-NP (>= 300 OD units)] were tested for neutralizing antibodies using an established viral luciferase antibody inhibition assay to detect the infection of SARS-CoV-2 pseudovirus that encoded spike protein (SARS2-S-trunc) on a human immunodeficiency virus 1 vector (NL43dEnvNanoLuc), using ACE2-expressing 293 T cells. The titer needed to neutralize 50% of viral activity (NT50) was calculated. Results The uptake of SARS-CoV-2 pseudovirus by 293T(ACE2) cells was inhibited by pretreatment with CP compared to control CP (p < .001) with control plasma having a median (IQR) 50% neutralization titer (NT50) of 1:28 (1:16,1:36) compared to 1:334 (1:130,1:1295) and 1:324 (1:244,1:578), for medium anti-NP and high anti-NP CP units, respectively. The neutralizing activity of CP met minimum FDA criteria with neutralizing antibody titers >1:80 in 100% of randomly selected samples, using a conservative approach that excluded non-specific binding. Discussion Plasma from donors screened using an immunochromatographic test for IgG antibody to SARS-CoV-2 NP exhibited neutralizing activity meeting FDA's minimum standard in all randomly selected COVID-19 CP units.
Rationale Metabolic dysfunction, mood disorders, anxiety disorders, and substance abuse disorders are associated with disruptions in circadian rhythm and circadian clock gene machinery. While the effects of alcohol on several core components of the clock genes have been described in rodent models, pharmacological activation or inhibition of clock gene functions has not been studied on alcohol drinking behaviors. Objectives We investigated whether cryptochrome (CRY1/2) activator KL001 altered alcohol intake in mice in excessive and relapse-like alcohol drinking models. Methods Mice, subjected to 3 weeks of chronic intermittent alcohol drinking (IAD) (two-bottle choice, 24-h access every other day) developed excessive alcohol intake and high preference. We evaluated the pharmacological effects of KL001 after either 1-day acute withdrawal from IAD or 1-week chronic withdrawal using the alcohol deprivation effect (ADE) model. Results Single pretreatment with KL001 at 1-4 mg kg(-1) reduced alcohol intake and preference after acute withdrawal in a dose-related manner. The effect of KL001 on reducing excessive alcohol consumption seems alcohol specific, as the compound does not alter sucrose (caloric reinforcer) or saccharin (noncaloric reinforcer) consumption in mice. Both single- and multiple-dosing regimens with an effective dose of KL001 (4 mg kg(-1)) prevented the ADE after chronic withdrawal, with no tolerance development after the multi-dosing regimen. Conclusions Pretreatment with KL001 (a CRY1/2 activator) reduces excessive and "relapse" alcohol drinking in mice. Our in vivo results with a CRY activator suggest a possible novel target for alcohol treatment intervention.
Cevher MA
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Reconstitution of Pol II (G) responsive form of the human Mediator complex

TURKISH JOURNAL OF BIOLOGY 2021; 45(3):253-261
RNA polymerase II (Pol II) is a 12 subunit protein complex from yeast to human that is required for gene expression. Gdownl containing Pol II [Pol II (G)] is a special form of Pol II that is catalytically inactive and heavily depends on the 30-subunit Mediator complex for its activator and basal dependent function in vitro. Here we report for the first time, the identification and the generation of a 15-subunit human Mediator complex via the novel multibac baculovirus expression system that is fully responsive to Pol II (G). Our results show complete recovery of Pol II (G) dependent transcription both with full 30-subunit Mediator and also with 15-subunit recombinant Mediator that we synthesized. Moreover, we also show that the recombinant Mediator interacts with Pol II (G) as well. These results enlighten us towards understanding how a certain population of Pol II that is involved in selected gene regulation is activated by Mediator complex.
Bastard P, Manry J, Chen J, Rosain J, Seeleuthner Y, AbuZaitun O, Lorenzo L, Khan T, Hasek M, Hernandez N, Bigio B, Zhang P, Levy R, Shrot S, Reino EJG, Lee YS, Boucherit S, Aubart M, Gijsbers R, Beziat V, Li Z, Pellegrini S, Rozenberg F, Marr N, Meyts I, Boisson B, Cobat A, Bustamante J, Zhang Q, Jouangy E, Abel L, Somech R, Casanova JL, Zhang SY
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Herpes simplex encephalitis in a patient with a distinctive form of inherited IFNAR1 deficiency

JOURNAL OF CLINICAL INVESTIGATION 2021 JAN 4; 131(1):? Article e139980
Inborn errors of TLR3-dependent IFN-alpha/beta- and IFN-lambda-mediated immunity in the CNS can underlie herpes simplex virus 1 (HSV-1) encephalitis (HSE). The respective contributions of IFN-alpha/beta and IFN-lambda are unknown. We report a child homozygous for a genomic deletion of the entire coding sequence and part of the 3'-UTR of the last exon of IFNAR1, who died of HSE at the age of 2 years. An older cousin died following vaccination against measles, mumps, and rubella at 12 months of age, and another 17-year-old cousin homozygous for the same variant has had other, less severe, viral illnesses. The encoded IFNAR1 protein is expressed on the cell surface but is truncated and cannot interact with the tyrosine kinase TYK2. The patient's fibroblasts and EBV-B cells did not respond to IFN-alpha 2b or IFN-beta, in terms of STAT1, STAT2, and STAT3 phosphorylation or the genome-wide induction of IFN-stimulated genes. The patient's fibroblasts were susceptible to viruses, including HSV-1, even in the presence of exogenous IFN-alpha 2b or IFN-beta. HSE is therefore a consequence of inherited complete IFNAR1 deficiency. This viral disease occurred in natural conditions, unlike those previously reported in other patients with IFNAR1 or IFNAR2 deficiency. This experiment of nature indicates that IFN-alpha/beta are essential for anti-HSV-1 immunity in the CNS.
Chandler JA, Cabrera LY, Doshi P, Fecteau S, Fins JJ, Guinjoan S, Hamani C, Herrera-Ferra K, Honey CM, Illes J, Kopell BH, Lipsman N, McDonald PJ, Mayberg HS, Nadler R, Nuttin B, Oliveira-Maia AJ, Rangel C, Ribeiro R, Salles A, Wu HM
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International Legal Approaches to Neurosurgery for Psychiatric Disorders

FRONTIERS IN HUMAN NEUROSCIENCE 2021 JAN 13; 14(?):? Article 588458
Neurosurgery for psychiatric disorders (NPD), also sometimes referred to as psychosurgery, is rapidly evolving, with new techniques and indications being investigated actively. Many within the field have suggested that some form of guidelines or regulations are needed to help ensure that a promising field develops safely. Multiple countries have enacted specific laws regulating NPD. This article reviews NPD-specific laws drawn from North and South America, Asia and Europe, in order to identify the typical form and contents of these laws and to set the groundwork for the design of an optimal regulation for the field. Key challenges for this design that are revealed by the review are how to define the scope of the law (what should be regulated), what types of regulations are required (eligibility criteria, approval procedures, data collection, and oversight mechanisms), and how to approach international harmonization given the potential migration of researchers and patients.
Schureck MA, Darling JE, Merk A, Shao JF, Daggupati G, Srinivasan P, Olinares PDB, Rout MP, Chait BT, Wollenberg K, Subramaniam S, Desai SA
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Malaria parasites use a soluble RhopH complex for erythrocyte invasion and an integral form for nutrient uptake

ELIFE 2021 JAN 4; 10(?):? Article e65282
Malaria parasites use the RhopH complex for erythrocyte invasion and channel-mediated nutrient uptake. As the member proteins are unique to Plasmodium spp., how they interact and traffic through subcellular sites to serve these essential functions is unknown. We show that RhopH is synthesized as a soluble complex of CLAG3, RhopH2, and RhopH3 with 1:1:1 stoichiometry. After transfer to a new host cell, the complex crosses a vacuolar membrane surrounding the intracellular parasite and becomes integral to the erythrocyte membrane through a PTEX translocon-dependent process. We present a 2.9 angstrom single-particle cryo-electron microscopy structure of the trafficking complex, revealing that CLAG3 interacts with the other subunits over large surface areas. This soluble complex is tightly assembled with extensive disulfide bonding and predicted transmembrane helices shielded. We propose a large protein complex stabilized for trafficking but poised for host membrane insertion through large-scale rearrangements, paralleling smaller two-state pore-forming proteins in other organisms.
Toubiana J, Cohen JF, Brice J, Poirault C, Bajolle F, Curtis W, Moulin F, Matczak S, Leruez M, Casanova JL, Chalumeau M, Taylor M, Allali S
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Distinctive Features of Kawasaki Disease Following SARS-CoV-2 Infection: a Controlled Study in Paris, France

JOURNAL OF CLINICAL IMMUNOLOGY 2021; 41(3):526-535
Background An outbreak of multisystem inflammatory syndrome in children, including Kawasaki disease (KD), emerged during COVID-19 pandemic. We explored whether Kawasaki-like disease (KD), when associated with confirmed SARS-CoV-2 infection, has specific characteristics. Methods We included children and adolescents with KD criteria admitted in the department of general pediatrics of a university hospital in Paris, France, between January 1, 2018, and May 26, 2020. The incidence of KD was compared between the outbreak and a pre-outbreak control period (January 1, 2018, to April 25). Characteristics of patients with positive SARS-CoV-2 testing (KD-SARS-CoV-2) were compared to those of the pre-outbreak period (classic KD). Results A total of 30 and 59 children with KD were admitted during the outbreak and pre-outbreak periods, respectively (incidence ratio 13.2 [8.3-21.0]). During the outbreak, 23/30 (77%) children were diagnosed as KD-SARS-CoV-2. When compared with patients with classic KD, those with KD-SARS-CoV-2 were more frequently of sub-Saharan African ancestry (OR 4.4 [1.6-12.6]) and older (median 8.2 vs. 4.0 years, p < 0.001), had more often initial gastrointestinal (OR 84 [4.9-1456]) and neurological (OR 7.3 [1.9-27.7] manifestations, and shock syndrome (OR 13.7 [4.2-45.1]). They had significantly higher CRP and ferritin levels. Noticeably, they had more frequently myocarditis (OR 387 [38-3933]). Conclusions Children and adolescents with KD-SARS-CoV-2 have specific features when compared with those with classic KD. These findings should raise awareness and facilitate the study of their pathogenesis.
Bartsch TF, Villasante CM, Hengel FE, Toure A, Firester DM, Oswald A, Hudspeth AJ
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Measurement of hindered diffusion in complex geometries for high-speed studies of single-molecule forces

SCIENTIFIC REPORTS 2021 JAN 26; 11(1):? Article 2196
In a high-speed single-molecule experiment with a force probe, a protein is tethered between two substrates that are manipulated to exert force on the system. To avoid nonspecific interactions between the protein and nearby substrates, the protein is usually attached to the substrates through long, flexible linkers. This approach precludes measurements of mechanical properties with high spatial and temporal resolution, for rapidly exerted forces are dissipated into the linkers. Because mammalian hearing operates at frequencies reaching tens to hundreds of kilohertz, the mechanical processes that occur during transduction are of very short duration. Single-molecule experiments on the relevant proteins therefore cannot involve long tethers. We previously characterized the mechanical properties of protocadherin 15 (PCDH15), a protein essential for human hearing, by tethering an individual monomer through very short linkers between a probe bead held in an optical trap and a pedestal bead immobilized on a glass coverslip. Because the two confining surfaces were separated by only the length of the tethered protein, hydrodynamic coupling between those surfaces complicated the interpretation of the data. To facilitate our experiments, we characterize here the anisotropic and position-dependent diffusion coefficient of a probe in the presence of an effectively infinite wall, the coverslip, and of the immobile pedestal.