Though therapeutics based on messenger RNA (mRNA) have broad potential in applications such as protein replacement therapy, cancer immunotherapy, and genomic engineering, their effective ...intracellular delivery remains a challenge. A chemically diverse suite of delivery materials with origins as materials for cellular transfection of DNA and small interfering RNAs (siRNAs) has recently been reported to have promise as non-viral delivery agents for mRNA. These materials include covalent conjugates, protamine complexes, nanoparticles based on lipids or polymers, and hybrid formulations. This review will highlight the use of delivery materials for mRNA, with a specific focus on their mechanisms of action, routes of administration, and dosages. Additionally, strategies in which these materials can be adapted and optimized to address challenges specific to mRNA delivery are also discussed. The technologies included have shown varying promise for therapeutic use, specifically having been used to deliver mRNA in vivo or exhibiting characteristics that could make in vivo use a possibility. In so doing, it is the intention of this review to provide a comprehensive look at the progress and possibilities in applying nucleic acid delivery technology specifically toward the emerging area of mRNA therapeutics.
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The liver is an important integrator of nutrient metabolism, yet no liver-derived factors regulating nutrient preference or carbohydrate appetite have been identified. Here we show that the liver ...regulates carbohydrate intake through production of the hepatokine fibroblast growth factor 21 (FGF21), which markedly suppresses consumption of simple sugars, but not complex carbohydrates, proteins, or lipids. Genetic loss of FGF21 in mice increases sucrose consumption, whereas acute administration or overexpression of FGF21 suppresses the intake of both sugar and non-caloric sweeteners. FGF21 does not affect chorda tympani nerve responses to sweet tastants, instead reducing sweet-seeking behavior and meal size via neurons in the hypothalamus. This liver-to-brain hormonal axis likely represents a negative feedback loop as hepatic FGF21 production is elevated by sucrose ingestion. We conclude that the liver functions to regulate macronutrient-specific intake by producing an endocrine satiety signal that acts centrally to suppress the intake of “sweets.”
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•The liver functions as a post-ingestive regulator of macronutrient preference•Carbohydrate activates hepatic ChREBP increasing production of FGF21 from the liver•FGF21 acts on the paraventricular nucleus of the hypothalamus to suppress sugar intake
Cravings for sweet foods are common, yet the mechanisms that influence the “sweet tooth” are not well-defined. von Holstein-Rathlou et al. show that in response to carbohydrate intake, the liver produces FGF21 to selectively suppress sugar appetite by acting on the PVN of the hypothalamus.
Therapeutic nucleic acids hold great promise for the treatment of disease but require vectors for safe and effective delivery. Synthetic nanoparticle vectors composed of poly(β‐amino esters) (PBAEs) ...and nucleic acids have previously demonstrated potential utility for local delivery applications. To expand this potential utility to include systemic delivery of mRNA, hybrid polymer–lipid nanoformulations for systemic delivery to the lungs were developed. Through coformulation of PBAEs with lipid–polyethylene glycol (PEG), mRNA formulations were developed with increased serum stability and increased in vitro potency. The formulations were capable of functional delivery of mRNA to the lungs after intravenous administration in mice. To our knowledge, this is the first report of the systemic administration of mRNA for delivery to the lungs using degradable polymer–lipid nanoparticles.
mRNA‐loaded nanoparticles were synthesized using degradable poly(β‐amino ester) terpolymers formulated with a PEG‐lipid. The PEG‐lipid imparted serum stability to the nanoparticles, which resulted in successful mRNA delivery to the lungs after systemic nanoparticle administration in mice.
Domesticated crops experience strong human-mediated selection aimed at developing high-yielding varieties adapted to local conditions. To detect regions of the wheat genome subject to selection ...during improvement, we developed a high-throughput array to interrogate 9,000 gene-associated single-nucleotide polymorphisms (SNP) in a worldwide sample of 2,994 accessions of hexaploid wheat including landraces and modern cultivars. Using a SNP-based diversity map we characterized the impact of crop improvement on genomic and geographic patterns of genetic diversity. We found evidence of a small population bottleneck and extensive use of ancestral variation often traceable to founders of cultivars from diverse geographic regions. Analyzing genetic differentiation among populations and the extent of haplotype sharing, we identified allelic variants subjected to selection during improvement Selective sweeps were found around genes involved in the regulation of flowering time and phenology. An introgression of a wild relative-derived gene conferring resistance to a fungal pathogen was detected by haplotype-based analysis. Comparing selective sweeps identified in different populations, we show that selection likely acts on distinct targets or multiple functionally equivalent alleles in different portions of the geographic range of wheat. The majority of the selected alleles were present at low frequency in local populations, suggesting either weak selection pressure or temporal variation in the targets of directional selection during breeding probably associated with changing agricultural practices or environmental conditions. The developed SNP chip and map of genetic variation provide a resource for advancing wheat breeding and supporting future population genomic and genome-wide association studies in wheat.
The Extended Distribution of Baryons around Galaxies Bregman, Joel N.; Anderson, Michael E.; Miller, Matthew J. ...
Astrophysical journal/The Astrophysical journal,
07/2018, Letnik:
862, Številka:
1
Journal Article
Recenzirano
Odprti dostop
We summarize and reanalyze observations bearing on missing galactic baryons, where we propose a consistent picture for halo gas in L L* galaxies. The hot X-ray-emitting halos are detected to 50-70 ...kpc, where typically Mhot(<50 kpc) ∼ 5 × 109 M , and with density n ∝ r−3/2. When extrapolated to R200, the gas mass is comparable to the stellar mass, but about half of the baryons are still missing from the hot phase. If extrapolated to 1.7R200-3R200, the ratio of baryon to dark matter approaches the cosmic value. Significantly flatter density profiles are unlikely for R < 50 kpc, and they are disfavored but not ruled out for R > 50 kpc. For the Milky Way, the hot halo metallicity lies in the range 0.3-1 solar for R < 50 kpc. Planck measurements of the thermal Sunyaev-Zel'dovich (SZ) effect toward stacked luminous galaxies (primarily early type) indicate that most of their baryons are hot, are near the virial temperature, and extend beyond R200. This stacked SZ signal is nearly an order of magnitude larger than that inferred from the X-ray observations of individual (mostly spiral) galaxies with M* > 1011.3 M . This difference suggests that the hot halo properties are distinct for early- and late-type galaxies, possibly due to different evolutionary histories. For the cooler gas detected in UV absorption line studies, we argue that there are two absorption populations: extended halos, and disks extending to ∼50 kpc, containing most of this gas, and with masses a few times lower than the stellar masses. Such extended disks are also seen in 21 cm H i observations and in simulations.
Dynamically restructuring pH‐responsive hydrogels are synthesized, employing dynamic covalent chemistry between phenylboronic acid and cis‐diol modified poly(ethylene glycol) macromonomers. These ...gels display shear‐thinning behavior, followed by a rapid structural recovery (self‐healing). Size‐dependent in vitro controlled and glucose‐responsive release of proteins from the hydrogel network, as well as the biocompatibility of the gels, are evaluated both in vitro and in vivo.
Candida albicans is a frequent colonizer of human mucosal surfaces as well as an opportunistic pathogen. C. albicans is remarkably versatile in its ability to colonize diverse host sites with ...differences in oxygen and nutrient availability, pH, immune responses, and resident microbes, among other cues. It is unclear how the genetic background of a commensal colonizing population can influence the shift to pathogenicity. Therefore, we examined 910 commensal isolates from 35 healthy donors to identify host niche-specific adaptations. We demonstrate that healthy people are reservoirs for genotypically and phenotypically diverse C. albicans strains. Using limited diversity exploitation, we identified a single nucleotide change in the uncharacterized ZMS1 transcription factor that was sufficient to drive hyper invasion into agar. We found that SC5314 was significantly different from the majority of both commensal and bloodstream isolates in its ability to induce host cell death. However, our commensal strains retained the capacity to cause disease in the Galleria model of systemic infection, including outcompeting the SC5314 reference strain during systemic competition assays. This study provides a global view of commensal strain variation and within-host strain diversity of C. albicans and suggests that selection for commensalism in humans does not result in a fitness cost for invasive disease.
Approximately 50% of acute myeloid leukemia (AML) patients do not respond to induction therapy (primary induction failure PIF) or relapse after <6 months (early relapse ER). We have recently shown an ...association between an immune-infiltrated tumor microenvironment (TME) and resistance to cytarabine-based chemotherapy but responsiveness to flotetuzumab, a bispecific DART antibody-based molecule to CD3ε and CD123. This paper reports the results of a multicenter, open-label, phase 1/2 study of flotetuzumab in 88 adults with relapsed/refractory AML: 42 in a dose-finding segment and 46 at the recommended phase 2 dose (RP2D) of 500 ng/kg per day. The most frequent adverse events were infusion-related reactions (IRRs)/cytokine release syndrome (CRS), largely grade 1-2. Stepwise dosing during week 1, pretreatment dexamethasone, prompt use of tocilizumab, and temporary dose reductions/interruptions successfully prevented severe IRR/CRS. Clinical benefit accrued to PIF/ER patients showing an immune-infiltrated TME. Among 30 PIF/ER patients treated at the RP2D, the complete remission (CR)/CR with partial hematological recovery (CRh) rate was 26.7%, with an overall response rate (CR/CRh/CR with incomplete hematological recovery) of 30.0%. In PIF/ER patients who achieved CR/CRh, median overall survival was 10.2 months (range, 1.87-27.27), with 6- and 12-month survival rates of 75% (95% confidence interval CI, 0.450-1.05) and 50% (95% CI, 0.154-0.846). Bone marrow transcriptomic analysis showed that a parsimonious 10-gene signature predicted CRs to flotetuzumab (area under the receiver operating characteristic curve = 0.904 vs 0.672 for the European LeukemiaNet classifier). Flotetuzumab represents an innovative experimental approach associated with acceptable safety and encouraging evidence of activity in PIF/ER patients. This trial was registered at www.clinicaltrials.gov as #NCT02152956.
Supramolecular PEGylation of biopharmaceuticals Webber, Matthew J.; Appel, Eric A.; Vinciguerra, Brittany ...
Proceedings of the National Academy of Sciences - PNAS,
12/2016, Letnik:
113, Številka:
50
Journal Article
Recenzirano
Odprti dostop
The covalent modification of therapeutic biomolecules has been broadly explored, leading to a number of clinically approved modified protein drugs. These modifications are typically intended to ...address challenges arising in biopharmaceutical practice by promoting improved stability and shelf life of therapeutic proteins in formulation, or modifying pharmacokinetics in the body. Toward these objectives, covalent modification with poly(ethylene glycol) (PEG) has been a common direction. Here, a platform approach to biopharmaceutical modification is described that relies on noncovalent, supramolecular host–guest interactions to endow proteins with prosthetic functionality. Specifically, a series of cucurbit7uril (CB7)–PEG conjugates are shown to substantially increase the stability of three distinct protein drugs in formulation. Leveraging the known and high-affinity interaction between CB7 and an N-terminal aromatic residue on one specific protein drug, insulin, further results in altering of its pharmacological properties in vivo by extending activity in a manner dependent on molecular weight of the attached PEG chain. Supramolecular modification of therapeutic proteins affords a noncovalent route to modify its properties, improving protein stability and activity as a formulation excipient. Furthermore, this offers a modular approach to append functionality to biopharmaceuticals by noncovalent modification with other molecules or polymers, for applications in formulation or therapy.
Nature has evolved diverse electron transport proteins and multiprotein assemblies essential to the generation and transduction of biological energy. However, substantially modifying or adapting ...these proteins for user‐defined applications or to gain fundamental mechanistic insight can be hindered by their inherent complexity. De novo protein design offers an attractive route to stripping away this confounding complexity, enabling us to probe the fundamental workings of these bioenergetic proteins and systems, while providing robust, modular platforms for constructing completely artificial electron‐conducting circuitry. Here, we use a set of de novo designed mono‐heme and di‐heme soluble and membrane proteins to delineate the contributions of electrostatic micro‐environments and dielectric properties of the surrounding protein medium on the inter‐heme redox cooperativity that we have previously reported. Experimentally, we find that the two heme sites in both the water‐soluble and membrane constructs have broadly equivalent redox potentials in isolation, in agreement with Poisson‐Boltzmann Continuum Electrostatics calculations. BioDC, a Python program for the estimation of electron transfer energetics and kinetics within multiheme cytochromes, also predicts equivalent heme sites, and reports that burial within the low dielectric environment of the membrane strengthens heme‐heme electrostatic coupling. We conclude that redox cooperativity in our diheme cytochromes is largely driven by heme electrostatic coupling and confirm that this effect is greatly strengthened by burial in the membrane. These results demonstrate that while our de novo proteins present minimalist, new‐to‐nature constructs, they enable the dissection and microscopic examination of processes fundamental to the function of vital, yet complex, bioenergetic assemblies.
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