Preparation, characterization, and safety evaluation of poly(lactide-co-glycolide) nanoparticles for protein delivery into macrophages.

International audienceFollowing infection, HIV establishes reservoirs within tissues that are inaccessible to optimal levels of antiviral drugs or within cells where HIV lies latent, thus escaping the action of anti-HIV drugs. Macrophages are a persistent reservoir for HIV and may contribute to the rebound viremia observed after antiretroviral treatment is stopped. In this study, we further investigate the potential of poly(lactic-co-glycolic) acid (PLGA)-based nanocarriers as a new strategy to enhance penetration of therapeutic molecules into macrophages. We have prepared stable PLGA nanoparticles (NPs) and evaluated their capacity to transport an active molecule into the human monocyte/macrophage cell line THP-1 using bovine serum albumin (BSA) as a proof-of-concept compound. Intracellular localization of fluorescent BSA molecules encapsulated into PLGA NPs was monitored in live cells using confocal microscopy, and cellular uptake was quantified by flow cytometry. In vitro and in vivo toxicological studies were performed to further determine the safety profile of PLGA NPs including inflammatory effects. The size of the PLGA NPs carrying BSA (PLGA-BSA) in culture medium containing 10% serum was ~126 nm in diameter, and they were negatively charged at their surface (zeta potential =-5.6 mV). Our confocal microscopy studies and flow cytometry data showed that these PLGA-BSA NPs are rapidly and efficiently taken up by THP-1 monocyte-derived macrophages (MDMs) at low doses. We found that PLGA-BSA NPs increased cellular uptake and internalization of the protein in vitro. PLGA NPs were not cytotoxic for THP-1 MDM cells, did not modulate neutrophil apoptosis in vitro, and did not show inflammatory effect in vivo in the murine air pouch model of acute inflammation. In contrast to BSA alone, BSA encapsulated into PLGA NPs increased leukocyte infiltration in vivo, suggesting the in vivo enhanced delivery and protection of the protein by the polymer nanocarrier. We demonstrated that PLGA-based nanopolymer carriers are good candidates to efficiently and safely enhance the transport of active molecules into human MDMs. In addition, we further investigated their inflammatory profile and showed that PLGA NPs have low inflammatory effects in vitro and in vivo. Thus, PLGA nanocarriers are promising as a drug delivery strategy in macrophages for prevention and eradication of intracellular pathogens such as HIV and Mycobacterium tuberculosis

Recurrent De Novo NAHR Reciprocal Duplications in the ATAD3 Gene Cluster Cause a Neurogenetic Trait with Perturbed Cholesterol and Mitochondrial Metabolism.

Recent studies have identified both recessive and dominant forms of mitochondrial disease that result from ATAD3A variants. The recessive form includes subjects with biallelic deletions mediated by non-allelic homologous recombination. We report five unrelated neonates with a lethal metabolic disorder characterized by cardiomyopathy, corneal opacities, encephalopathy, hypotonia, and seizures in whom a monoallelic reciprocal duplication at the ATAD3 locus was identified. Analysis of the breakpoint junction fragment indicated that these 67 kb heterozygous duplications were likely mediated by non-allelic homologous recombination at regions of high sequence identity in ATAD3A exon 11 and ATAD3C exon 7. At the recombinant junction, the duplication allele produces a fusion gene derived from ATAD3A and ATAD3C, the protein product of which lacks key functional residues. Analysis of fibroblasts derived from two affected individuals shows that the fusion gene product is expressed and stable. These cells display perturbed cholesterol and mitochondrial DNA organization similar to that observed for individuals with severe ATAD3A deficiency. We hypothesize that the fusion protein acts through a dominant-negative mechanism to cause this fatal mitochondrial disorder. Our data delineate a molecular diagnosis for this disorder, extend the clinical spectrum associated with structural variation at the ATAD3 locus, and identify a third mutational mechanism for ATAD3 gene cluster variants. These results further affirm structural variant mutagenesis mechanisms in sporadic disease traits, emphasize the importance of copy number analysis in molecular genomic diagnosis, and highlight some of the challenges of detecting and interpreting clinically relevant rare gene rearrangements from next-generation sequencing data

Consequences of conformational flexibility in hydrogen-bond-driven self-assembly processes

We report the synthesis and self-assembly of chiral, conformationally flexible C3-symmetrical trisamides. A strong Cotton effect is observed for the supramolecular polymers in linear alkanes but not in cyclic alkanes. MD simulations suggest 2:1 conformations of the amides within the aggregates in both types of solvents, but a chiral bias in only linear alkanes.JAB, MGI, RPAG, EWM and ARAP would like to thank the Gravity program 024.001.035, NWO TOP-PUNT 718.014.003 for financial support and Anneloes Oude Vrielink for TEM imaging. FDM and ML acknowledge the Swedish e-Research Center (SeRC) for financial support, the Swedish Research Council (Grant No. 621-2014-4646), SNIC (Swedish National Infrastructure for Computing) and Dr Julien Idé for providing the code for exciton coupling calculations

Brief Report: AIP Mutation in Pituitary Adenomas in the 18th Century and Today

From New England Journal of Medicine, Volume 364, issue 1, p.43-50. Copyright © (2011) Massachusetts Medical Society. Reprinted with permission.Gigantism results when a growth hormone–secreting pituitary adenoma is present before epiphyseal fusion. In 1909, when Harvey Cushing examined the skeleton of an Irish patient who lived from 1761 to 1783,1-3 he noted an enlarged pituitary fossa. We extracted DNA from the patient’s teeth and identified a germline mutation in the aryl hydrocarbon–interacting protein gene (AIP). Four contemporary Northern Irish families who presented with gigantism, acromegaly, or prolactinoma have the same mutation and haplotype associated with the mutated gene. Using coalescent theory, we infer that these persons share a common ancestor who lived about 57 to 66 generations earlier

Diagnosis of lethal or prenatal-onset autosomal recessive disorders by parental exome sequencing.

OBJECTIVE: Rare genetic disorders resulting in prenatal or neonatal death are genetically heterogeneous, but testing is often limited by the availability of fetal DNA, leaving couples without a potential prenatal test for future pregnancies. We describe our novel strategy of exome sequencing parental DNA samples to diagnose recessive monogenic disorders in an audit of the first 50 couples referred. METHOD: Exome sequencing was carried out in a consecutive series of 50 couples who had 1 or more pregnancies affected with a lethal or prenatal-onset disorder. In all cases, there was insufficient DNA for exome sequencing of the affected fetus. Heterozygous rare variants (MAF < 0.001) in the same gene in both parents were selected for analysis. Likely, disease-causing variants were tested in fetal DNA to confirm co-segregation. RESULTS: Parental exome analysis identified heterozygous pathogenic (or likely pathogenic) variants in 24 different genes in 26/50 couples (52%). Where 2 or more fetuses were affected, a genetic diagnosis was obtained in 18/29 cases (62%). In most cases, the clinical features were typical of the disorder, but in others, they result from a hypomorphic variant or represent the most severe form of a variable phenotypic spectrum. CONCLUSION: We conclude that exome sequencing of parental samples is a powerful strategy with high clinical utility for the genetic diagnosis of lethal or prenatal-onset recessive disorders. © 2017 The Authors Prenatal Diagnosis published by John Wiley & Sons Ltd

Fault-tolerant grid-based solvers: Combining concepts from sparse grids and MapReduce

A key issue confronting petascale and exascale computing is the growth in probability of soft and hard faults with increasing system size. A promising approach to this problem is the use of algorithms that are inherently fault tolerant. We introduce such an algorithm for the solution of partial differential equations, based on the sparse grid approach. Here, the solution of multiple component grids are efficiently combined to achieve a solution on a full grid. The technique also lends itself to a (modified) MapReduce framework on a cluster of processors, with the map stage corresponding to allocating each component grid for solution over a subset of the processors, and the reduce stage corresponding to their combination. We describe how the sparse grid combination method can be modified to robustly solve partial differential equations in the presence of faults. This is based on a modified combination formula that can accommodate the loss of one or two component grids. We also discuss accuracy issues associated with this formula. We give details of a prototype implementation within a MapReduce framework using the dynamic process features and asynchronous message passing facilities of MPI. Results on a two-dimensional advection problem show that the errors after the loss of one or two sub-grids are within a factor of 3 of the sparse grid solution in the presence of no faults. They also indicate that the sparse grid technique with four times the resolution has approximately the same error as a full grid, while requiring (for a sufficiently high resolution) much lower computation and memory requirements. We finally outline a MapReduce variant capable of responding to faults in ways other than re-scheduling of failed tasks. We discuss the likely software requirements for such a flexible MapReduce framework, the requirements it will impose on users’ legacy codes, and the system's runtime behavior.J. W. Larson, M. Hegland, B. Harding, S. Roberts, L. Stals, A. P. Rendell, P. Strazdins, M. M. Ali, C. Kowitz, R. Nobes, J. Southern, N. Wilson, M. Li, Y. Oish

Effect of Food Residues on Norovirus Survival on Stainless Steel Surfaces

Background: In households and food processing plants, minute food residues left behind from improper cleaning may influence the survivability of human norovirus on surfaces. In this study, the survivability of norovirus on desiccated food residue-attached stainless steel coupons was investigated. Methodology/Principal Findings: Using murine norovirus-1 (MNV-1) as a surrogate of human norovirus, the survivability of norovirus was investigated on lettuce, cabbage, or ground pork-attached stainless steel coupons. A 6.2 log MPN/ml of MNV-1 infectivity was completely lost at day 30 in residue-free coupons, whereas only a 1.4 log MPN/ml reduction was observed in coupons with residues. Moreover, the disinfective effect of sodium hypochlorite was reduced when residues were present on the coupons. Conclusions/Significance: This study revealed that the food residues increased the survivability and the resistance to chemicals of norovirus, indicating the need of thorough cleaning in food processing plants and household settings