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1.
Brain Res ; 1832: 148854, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38493572

RESUMO

Since the mid-2000's, many researchers have provided evidence that mu-ERD measured at the motor cortex may reflect the collective activation of upstream brain regions associated with the human mirror system during action observation paradigms; however, several recent papers have called these findings into question. Our study represents an effort to address these criticisms. In our study, participants watched videos in which the type of grip an actor used to grasp a coffee mug either conveyed the goal with 100 % certainty (unambiguous-goal trials), or offered no predictive information (ambiguous-goal trials). If mu-ERD indexes action understanding, then we predicted that mu-ERD should increase while participants watched the actor grasp the mug for unambiguous-goal trials, but not for ambiguous-goal trials. During the intervals where participants watched the actor execute the goal, mu-ERD for unambiguous-goal trials should remain steady, whereas mu-ERD for ambiguous-goal trials should now increase. Conversely, if mu-ERD does not index action understanding, and instead reflects general motor processes associated with action (such as the activation of population vectors in M1 or planning processes), then mu-ERD should show no difference across conditions. Across most comparisons, we found that mu-ERD mostly reflected general motor processes; however, there was a small effect when participants overserved unambiguous-goal trials while watching the actor execute the goal suggesting that mu-ERD does reflect mirroring, but the effect is small.


Assuntos
Encéfalo , Eletroencefalografia , Humanos , Motivação , Movimento/fisiologia
3.
Genome Med ; 16(1): 26, 2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38321573

RESUMO

BACKGROUND: Evolutionary models of breast cancer progression differ on the extent to which metastatic potential is pre-encoded within primary tumors. Although metastatic recurrences often harbor putative driver mutations that are not detected in their antecedent primary tumor using standard sequencing technologies, whether these mutations were acquired before or after dissemination remains unclear. METHODS: To ascertain whether putative metastatic driver mutations initially deemed specific to the metastasis by whole exome sequencing were, in actuality, present within rare ancestral subclones of the primary tumors from which they arose, we employed error-controlled ultra-deep sequencing (UDS-UMI) coupled with FFPE artifact mitigation by uracil-DNA glycosylase (UDG) to assess the presence of 132 "metastasis-specific" mutations within antecedent primary tumors from 21 patients. Maximum mutation detection sensitivity was ~1% of primary tumor cells. A conceptual framework was developed to estimate relative likelihoods of alternative models of mutation acquisition. RESULTS: The ancestral primary tumor subclone responsible for seeding the metastasis was identified in 29% of patients, implicating several putative drivers in metastatic seeding including LRP5 A65V and PEAK1 K140Q. Despite this, 93% of metastasis-specific mutations in putative metastatic driver genes remained undetected within primary tumors, as did 96% of metastasis-specific mutations in known breast cancer drivers, including ERRB2 V777L, ESR1 D538G, and AKT1 D323H. Strikingly, even in those cases in which the rare ancestral subclone was identified, 87% of metastasis-specific putative driver mutations remained undetected. Modeling indicated that the sequential acquisition of multiple metastasis-specific driver or passenger mutations within the same rare subclonal lineage of the primary tumor was highly improbable. CONCLUSIONS: Our results strongly suggest that metastatic driver mutations are sequentially acquired and selected within the same clonal lineage both before, but more commonly after, dissemination from the primary tumor, and that these mutations are biologically consequential. Despite inherent limitations in sampling archival primary tumors, our findings indicate that tumor cells in most patients continue to undergo clinically relevant genomic evolution after their dissemination from the primary tumor. This provides further evidence that metastatic recurrence is a multi-step, mutation-driven process that extends beyond primary tumor dissemination and underscores the importance of longitudinal tumor assessment to help guide clinical decisions.


Assuntos
Neoplasias da Mama , Humanos , Feminino , Neoplasias da Mama/genética , Mutação , Sequenciamento do Exoma
4.
Cancer Cell ; 42(1): 52-69.e7, 2024 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-38065100

RESUMO

Breast cancer mortality results from incurable recurrences thought to be seeded by dormant, therapy-refractory residual tumor cells (RTCs). Understanding the mechanisms enabling RTC survival is therefore essential for improving patient outcomes. Here, we derive a dormancy-associated RTC signature that mirrors the transcriptional response to neoadjuvant therapy in patients and is enriched for extracellular matrix-related pathways. In vivo CRISPR-Cas9 screening of dormancy-associated candidate genes identifies the galactosyltransferase B3GALT6 as a functional regulator of RTC fitness. B3GALT6 is required for glycosaminoglycan (GAG) linkage to proteins to generate proteoglycans, and its germline loss of function in patients causes skeletal dysplasias. We find that B3GALT6-mediated biosynthesis of heparan sulfate GAGs predicts poor patient outcomes and promotes tumor recurrence by enhancing dormant RTC survival in multiple contexts, and does so via a B3GALT6-heparan sulfate/HS6ST1-heparan 6-O-sulfation/FGF1-FGFR2 signaling axis. These findings implicate B3GALT6 in cancer and nominate FGFR2 inhibition as a promising approach to eradicate dormant RTCs and prevent recurrence.


Assuntos
Neoplasias da Mama , Humanos , Feminino , Neoplasias da Mama/genética , Sobrevivência Celular/genética , Recidiva Local de Neoplasia/genética , Heparitina Sulfato/metabolismo , Glicosaminoglicanos/metabolismo , Galactosiltransferases/genética
5.
New Phytol ; 240(2): 613-625, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37571856

RESUMO

Phenotypic plasticity allows organisms to optimize traits for their environment. As organisms age, they experience diverse environments that benefit from varying degrees of phenotypic plasticity. Developmental transitions can control these age-dependent changes in plasticity, and as such, the timing of these transitions can determine when plasticity changes in an organism. Here, we investigate how the transition from juvenile-to adult-vegetative development known as vegetative phase change (VPC) contributes to age-dependent changes in phenotypic plasticity and how the timing of this transition responds to environment using both natural accessions and mutant lines in the model plant Arabidopsis thaliana. We found that the adult phase of vegetative development has greater plasticity in leaf morphology than the juvenile phase and confirmed that this difference in plasticity is caused by VPC using mutant lines. Furthermore, we found that the timing of VPC, and therefore the time when increased plasticity is acquired, varies significantly across genotypes and environments. The consistent age-dependent changes in plasticity caused by VPC suggest that VPC may be adaptive. This genetic and environmental variation in the timing of VPC indicates the potential for population-level adaptive evolution of VPC.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Folhas de Planta/genética , Fenótipo , Adaptação Fisiológica
6.
Artigo em Inglês | MEDLINE | ID: mdl-35627370

RESUMO

Where ticks are found, tick-borne diseases can present a threat to human and animal health. The aetiology of many of these important diseases, including Lyme disease, bovine babesiosis, tick-borne fever and louping ill, have been known for decades whilst others have only recently been documented in the United Kingdom (UK). Further threats such as the importation of exotic ticks through human activity or bird migration, combined with changes to either the habitat or climate could increase the risk of tick-borne disease persistence and transmission. Prevention of tick-borne diseases for the human population and animals (both livestock and companion) is dependent on a thorough understanding of where and when pathogen transmission occurs. This information can only be gained through surveillance that seeks to identify where tick populations are distributed, which pathogens are present within those populations, and the periods of the year when ticks are active. To achieve this, a variety of approaches can be applied to enhance knowledge utilising a diverse range of stakeholders (public health professionals and veterinarians through to citizen scientists). Without this information, the application of mitigation strategies to reduce pathogen transmission and impact is compromised and the ability to monitor the effects of climate change or landscape modification on the risk of tick-borne disease is more challenging. However, as with many public and animal health interventions, there needs to be a cost-benefit assessment on the most appropriate intervention applied. This review will assess the challenges of tick-borne diseases in the UK and argue for a cross-disciplinary approach to their surveillance and control.


Assuntos
Doença de Lyme , Saúde Única , Doenças Transmitidas por Carrapatos , Carrapatos , Animais , Doença de Lyme/epidemiologia , Doença de Lyme/prevenção & controle , Doenças Transmitidas por Carrapatos/epidemiologia , Reino Unido/epidemiologia
7.
Rev. bras. oftalmol ; 81: e0016, 2022. graf
Artigo em Inglês | LILACS | ID: biblio-1365729

RESUMO

ABSTRACT Reticular pigmentary retinal dystrophy, also known as Sjögren's reticular dystrophy, is a rare condition characterized by macular lesions with a reticular pattern, which are best seen on fluorescein angiogram. Choroidal neovascularization secondary to this type of dystrophy is even less common. This report describes a case of reticular pigmentary retinal dystrophy with vision loss due to neovascular membrane, which responded well to treatment with anti-vascular endothelial growth factor.


RESUMO A distrofia reticular pigmentar da retina, também conhecida como distrofia reticular de Sjögren, é uma doença rara, caracterizada por lesões maculares com um padrão reticular, que são mais bem visualizadas na angiografia com fluoresceína. A neovascularização de coroide secundária a este tipo de distrofia é ainda menos comum. Este relato descreve um caso de distrofia reticular pigmentar da retina, com perda de visão devido à membrana neovascular, que respondeu bem ao tratamento com fator de crescimento endotelial antivascular.


Assuntos
Humanos , Masculino , Idoso , Retinose Pigmentar/complicações , Neovascularização de Coroide/etiologia , Neovascularização de Coroide/tratamento farmacológico , Distrofias Retinianas/complicações , Ranibizumab/administração & dosagem , Síndrome de Sjogren/complicações , Seguimentos , Neovascularização de Coroide/diagnóstico , Inibidores da Angiogênese/administração & dosagem , Inibidores da Angiogênese/uso terapêutico , Injeções Intravítreas , Ranibizumab/uso terapêutico
8.
Talanta ; 210: 120188, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31987164

RESUMO

Myo-inositol hexakisphosphate, or phytic acid, (myo-IP6) is a key organic phosphorus (P) compound in soils and manures. Determinations of myo-IP6 in soils and manure extracts are frequently performed by 31P NMR spectroscopy. This approach is time-consuming in terms of both sample preparation and instrument time, with uncertainties existing in relation to accuracy of identification and quantification due to potentially interfering resonances from co-extracted P species. In contrast, ion chromatography (IC) in combination with high-resolution mass spectrometry (HRMS) negative ion, electrospray ionisation (ESI) has been shown to enable highly specific identifications of myo-IP6 isolated from complex mixtures. In this paper, IC and ESI-HRMS were applied to the identification and the quantification of myo-IP6 isolated from soils and manures using NaOH-EDTA extraction, and quantifications based on IC. ESI-HRMS analysis of eluate trapped from IC unequivocally confirmed identification of myo-IP6 from a soil extract. The ion suppression cell of the IC instrument provides isolates of the analyte free of ionic components that would interfere with ESI. The myo-IP6 was identified in the NMR by comparing spectra of extracts of soils with and without authentic myo-IP6 "spiked" prior to extraction. Comparison of quantification via standard addition in IC and NMR analysis gave good correlation (r = 0.955). IC with ESI-HRMS was found to be more sensitive, rapid and reliable for the identification and quantification of myo-IP6 with a limit of detection (LOD) of 0.7 mg kg-1 and limit of quantification (LOQ) of 2.1 mg kg-1 using IC versus > 10 mg kg-1 LOD using 31P NMR.

9.
Bioconjug Chem ; 28(10): 2507-2513, 2017 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-28972368

RESUMO

The development of chemical strategies for site-specific protein modification now enables researchers to attach polyethylene glycol (PEG) to a protein drug at one or more specific locations (i.e., protein PEGylation). However, aside from avoiding enzyme active sites or protein-binding interfaces, distinguishing the optimal PEGylation site from the available alternatives has conventionally been a matter of trial and error. As part of a continuing effort to develop guidelines for identifying optimal PEGylation sites within proteins, we show here that the impact of PEGylation at various sites within the ß-sheet model protein WW depends strongly on the identity of the PEG-protein linker. The PEGylation of Gln or of azidohomoalanine has a similar impact on WW conformational stability as does Asn-PEGylation, whereas the PEGylation of propargyloxyphenylalanine is substantially stabilizing at locations where Asn-PEGylation was destabilizing. Importantly, we find that at least one of these three site-specific PEGylation strategies leads to substantial PEG-based stabilization at each of the positions investigated, highlighting the importance of considering conjugation strategy as an important variable in selecting optimal PEGylation sites. We further demonstrate that using a branched PEG oligomer intensifies the impact of PEGylation on WW conformational stability and also show that PEG-based increases to conformational stability are strongly associated with corresponding increases in proteolytic stability.


Assuntos
Polietilenoglicóis/química , Proteínas/química , Proteínas/metabolismo , Proteólise , Sequência de Aminoácidos , Modelos Moleculares , Conformação Proteica em Folha beta , Estabilidade Proteica
10.
BioDrugs ; 31(5): 423-438, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28875300

RESUMO

The advent of RNA interference (RNAi) technology has profoundly impacted molecular biology research and medicine but has also advanced the field of skin care. Both effector molecules of RNAi, short-interfering RNA molecules and microRNAs (miRNAs), have been explored for their relative impact and utility for treating a variety of skin conditions. These post-transcriptional RNA regulatory molecules down-modulate protein expression through targeting of the 3' untranslated regions of messenger RNAs, leading to their degradation or repression through sequestration. As researchers hunt for genetic linkages to skin diseases, miRNA regulators have emerged as key players in the biology of keratinocytes, fibroblasts, melanocytes, and other cells of the skin. Herein, we attempt to coalesce the current efforts to combat various skin disorders and diseases through the development of miRNA-based technologies.


Assuntos
MicroRNAs/genética , RNA Interferente Pequeno/genética , Dermatopatias/terapia , Regiões 3' não Traduzidas/genética , Fibroblastos/metabolismo , Humanos , Queratinócitos/metabolismo , Melanócitos/metabolismo , Interferência de RNA , Dermatopatias/genética , Dermatopatias/fisiopatologia
11.
Virol J ; 14(1): 71, 2017 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-28388926

RESUMO

BACKGROUND: Changes in the levels of circulating microRNAs (miRNAs) in the serum of humans and animals have been detected as a result of infection with a variety of viruses. However, to date, such a miRNA profiling study has not been conducted for foot-and-mouth disease virus (FMDV) infection. METHODS: The relative abundance of 169 miRNAs was measured in bovine serum collected at three different phases of FMDV infection in a proof-of-concept study using miRNA PCR array plates. RESULTS: Alterations in specific miRNA levels were detected in serum during acute, persistent, and convalescent phases of FMDV infection. Subclinical FMDV persistence produced a circulating miRNA profile distinct from cattle that had cleared infection. bta-miR-17-5p was highest expressed during acute infection, whereas bta-miR-31 was the highest during FMDV persistence. Interestingly, miR-1281was significantly down-regulated during both acute and persistent infection. Cattle that cleared infection resembled the baseline profile, adding support to applying serum miRNA profiling for identification of sub-clinically infected FMDV carriers. Significantly regulated miRNAs during acute or persistent infection were associated with cellular proliferation, apoptosis, modulation of the immune response, and lipid metabolism. CONCLUSIONS: These findings suggest a role for non-coding regulatory RNAs in FMDV infection of cattle. Future studies will delineate the individual contributions of the reported miRNAs to FMDV replication, determine if this miRNA signature is applicable across all FMDV serotypes, and may facilitate development of novel diagnostic applications.


Assuntos
Doenças dos Bovinos/patologia , Febre Aftosa/patologia , MicroRNAs/sangue , Soro/química , Animais , Bovinos
12.
Virus Genes ; 53(3): 340-351, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28364140

RESUMO

The Jumonji C-domain containing protein 6 (JMJD6) has had a convoluted history, and recent reports indicating a multifactorial role in foot-and-mouth disease virus (FMDV) infection have further complicated the functionality of this protein. It was first identified as the phosphatidylserine receptor on the cell surface responsible for recognizing phosphatidylserine on the surface of apoptotic cells resulting in their engulfment by phagocytic cells. Subsequent study revealed a nuclear subcellular localization, where JMJD6 participated in lysine hydroxylation and arginine demethylation of histone proteins and other non-histone proteins. Interestingly, to date, JMDJ6 remains the only known arginine demethylase with a growing list of known substrate molecules. These conflicting associations rendered the subcellular localization of JMJD6 to be quite nebulous. Further muddying this area, two different groups illustrated that JMJD6 could be induced to redistribute from the cell surface to the nucleus of a cell. More recently, JMJD6 was demonstrated to be a host factor contributing to the FMDV life cycle, where it was not only exploited for its arginine demethylase activity, but also served as an alternative virus receptor. This review attempts to coalesce these divergent roles for a single protein into one cohesive account. Given the diverse functionalities already characterized for JMJD6, it is likely to continue to be a confounding protein resulting in much contention going into the near future.


Assuntos
Vírus da Febre Aftosa/metabolismo , Febre Aftosa/virologia , Histona Desmetilases com o Domínio Jumonji/fisiologia , Replicação Viral/fisiologia , Animais , Arginina/metabolismo , Membrana Celular/metabolismo , Núcleo Celular/enzimologia , Núcleo Celular/genética , Febre Aftosa/enzimologia , Febre Aftosa/genética , Vírus da Febre Aftosa/genética , Vírus da Febre Aftosa/crescimento & desenvolvimento , Histona Desmetilases/metabolismo , Histonas , Interações Hospedeiro-Patógeno , Humanos , Lisina/metabolismo , Fagócitos/virologia , Fosfatidilserinas/metabolismo , Pró-Colágeno-Lisina 2-Oxoglutarato 5-Dioxigenase/metabolismo , Ligação Proteica , Receptores de Superfície Celular/metabolismo
13.
Eur J Pharm Sci ; 102: 46-54, 2017 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-28238945

RESUMO

The delivery of drugs to the brain is a constant challenge due to limitations imposed by the blood-brain barrier (BBB). Various methods of bypassing the BBB are under investigation. One approach is intranasal administration, where the olfactory region of the nasal cavity extends up to the cranial cavity and provides direct access to the brain. The pharmacokinetics of this transport and factors that determine transport rates and capacity is of vital importance for evaluating the clinical value of this route. Here, the pharmacokinetics of intranasally administered imatinib has been explored. Imatinib is distributed into the brain following intravenous administration, and then rapidly removed. Following intravenous administration, the brain/plasma ratio for imatinib was calculated to be 2% and remained at this ratio for 30min. The brain/plasma ratio following intranasal administration, however, was found to be 5.3% and remained at this ratio for up to 90min. Imatinib was found to be rapidly transported into the brain via the olfactory region, by shutting down the nose-to-blood-to-brain transport with epinephrine. The increased brain concentration of imatinib (0.33µg/g tissue) achieved by intranasal administration, compared with an IV injection, is likely to provide a model for developing a wide range of CNS active molecules that were previously removed from consideration as drug candidates due to their lack of CNS access. Furthermore, brain imatinib levels were increased by co-administration of the p-gp substrates, elacridar and pantoprazole, showing that both compounds were able to inhibit the elimination of imatinib from the brain.


Assuntos
Antineoplásicos/farmacocinética , Encéfalo/metabolismo , Mesilato de Imatinib/farmacocinética , Mucosa Nasal/metabolismo , Inibidores de Proteínas Quinases/farmacocinética , 2-Piridinilmetilsulfinilbenzimidazóis/farmacologia , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/antagonistas & inibidores , Acridinas/farmacologia , Administração Intranasal , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/sangue , Transporte Biológico , Epinefrina/farmacologia , Feminino , Mesilato de Imatinib/administração & dosagem , Mesilato de Imatinib/sangue , Injeções Intravenosas , Masculino , Camundongos Endogâmicos BALB C , Pantoprazol , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/sangue , Tetra-Hidroisoquinolinas/farmacologia
14.
Virology ; 504: 52-62, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28152384

RESUMO

Sam68 was previously shown to be a critical host factor for foot-and-mouth disease virus (FMDV) replication. MicroRNA (miR) miR-203a is reportedly a negative regulator of Sam68 expression both in vitro and in vivo. Here, transfection of miR-203a-3p and miR-203a-5p mimics separately and in combination in a porcine cell line followed by FMDV infection resulted in diminished viral protein synthesis and a 4 and 6log reduction in virus titers relative to negative controls, respectively. Unexpectedly, Sam68 expression was increased by miR-203a-5p transfection, but not miR-203a-3p. miR-203a-5p also down-regulated Survivin expression, which was predicted to play a role in FMDV infection. Moreover, miR-203a-5p but not miR-203a-3p affected a reduction in FMDV viral RNA. These effects were not replicated with a related Picornavirus, suggesting FMDV specificity. Importantly, miR-203a-3p and miR-203a-5p impaired FMDV infection across multiple FMDV serotypes. We concluded that miR-203a-3p and miR-203a-5p represent attractive potential naturally occurring bio-therapeutics against FMDV.


Assuntos
Vírus da Febre Aftosa/crescimento & desenvolvimento , Vírus da Febre Aftosa/genética , MicroRNAs/genética , Carga Viral/genética , Replicação Viral/genética , Animais , Bovinos , Linhagem Celular , Progressão da Doença , Cães , Enterovirus Bovino/genética , Células Madin Darby de Rim Canino , Biossíntese de Proteínas/genética , Interferência de RNA , RNA Interferente Pequeno/genética , Suínos
15.
Chem Commun (Camb) ; 53(53): 7258-7261, 2017 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-28054054

RESUMO

We present the synthesis of a B-N analogue of polystyrene, poly(N-methyl-B-vinylazaborine) in high molecular weight (MW = 24.9 kDa). Furthermore, it was possible to prepare a copolymer with the C-C analogue. A thorough comparison between the polymers by NMR spectroscopy, TGA, DSC and GPC showed significant differences between these polymers.

16.
Entropy (Basel) ; 20(1)2017 Dec 25.
Artigo em Inglês | MEDLINE | ID: mdl-33265097

RESUMO

Classical chaos is often characterized as exponential divergence of nearby trajectories. In many interesting cases these trajectories can be identified with geodesic curves. We define here the entropy by S = ln χ ( x ) with χ ( x ) being the distance between two nearby geodesics. We derive an equation for the entropy, which by transformation to a Riccati-type equation becomes similar to the Jacobi equation. We further show that the geodesic equation for a null geodesic in a double-warped spacetime leads to the same entropy equation. By applying a Robertson-Walker metric for a flat three-dimensional Euclidean space expanding as a function of time, we again reach the entropy equation stressing the connection between the chosen entropy measure and time. We finally turn to the Raychaudhuri equation for expansion, which also is a Riccati equation similar to the transformed entropy equation. Those Riccati-type equations have solutions of the same form as the Jacobi equation. The Raychaudhuri equation can be transformed to a harmonic oscillator equation, and it has been shown that the geodesic deviation equation of Jacobi is essentially equivalent to that of a harmonic oscillator. The Raychaudhuri equations are strong geometrical tools in the study of general relativity and cosmology. We suggest a refined entropy measure applicable in cosmology and defined by the average deviation of the geodesics in a congruence.

17.
Curr Opin Chem Biol ; 34: 88-94, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27580482

RESUMO

PEGylation is an important strategy for enhancing the pharmacokinetic properties of protein therapeutics. The development of chemoselective side-chain modification reactions has enabled researchers to PEGylate proteins with high selectivity at defined locations. However, aside from avoiding active sites and binding interfaces, there are few guidelines for the selection of optimal PEGylation sites. Because conformational stability is intimately related to the ability of a protein to avoid proteolysis, aggregation, and immune responses, it is possible that PEGylating a protein at sites where PEG enhances conformational stability will result in PEG-protein conjugates with enhanced pharmacokinetic properties. However, the impact of PEGylation on protein conformational stability is incompletely understood. This review describes recent advances toward understanding the impact of PEGylation on protein conformational stability, along with the development of structure-based guidelines for selecting stabilizing PEGylation sites.


Assuntos
Polietilenoglicóis/química , Estabilidade Proteica , Farmacocinética , Conformação Proteica
18.
ACS Chem Biol ; 11(7): 1805-9, 2016 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-27191252

RESUMO

Site-specific PEGylation is an important strategy for enhancing the pharmacokinetic properties of protein drugs, and has been enabled by the recent development of many chemoselective reactions for protein side-chain modification. However, the impact of these different conjugation strategies on the properties of PEG-protein conjugates is poorly understood. Here we show that the ability of PEG to enhance protein conformational stability depends strongly on the identity of the PEG-protein linker, with the most stabilizing linkers involving conjugation of PEG to planar polar groups near the peptide backbone. We also find that branched PEGs provide superior stabilization relative to their linear counterparts, suggesting additional applications for branched PEGs in protein stabilization.


Assuntos
Polietilenoglicóis/química , Proteínas/química , Dicroísmo Circular , Conformação Proteica , Estabilidade Proteica
19.
Virology ; 492: 108-17, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26914509

RESUMO

A companion study reported Jumonji-C domain containing protein 6 (JMJD6) is involved in an integrin- and HS-independent pathway of FMDV infection in CHO cells. JMJD6 localization was investigated in animal tissues from cattle infected with either wild type A24-FMDV (A24-WT) or mutant FMDV (JMJD6-FMDV) carrying E95K/S96L and RGD to KGE mutations in VP1. Additionally, pathogenesis of mutant JMJD6-FMDV was investigated in cattle through aerosol and intraepithelial lingual (IEL) inoculation. Interestingly, JMJD6-FMDV pathogenesis was equivalent to A24-WT administered by IEL route. In contrast, JMJD6-FMDV aerosol-infected cattle did not manifest signs of FMD and animals showed no detectable viremia. Immunofluorescent microscopy of post-mortem tissue revealed JMJD6-FMDV exclusively co-localized with JMJD6(+) cells while A24-WT was occasionally found in JMJD6(+) cells. In vitro, chemical uptake inhibitors demonstrated JMJD6-FMDV entered cells via clathrin-coated pit endocytosis. In vivo, JMJD6-FMDV exhibited preference for JMJD6(+) cells, but availability of this alternative receptor likely depends on route of inoculation.


Assuntos
Doenças dos Bovinos/prevenção & controle , Vírus da Febre Aftosa/imunologia , Febre Aftosa/prevenção & controle , Histona Desmetilases com o Domínio Jumonji/imunologia , Vacinação , Administração por Inalação , Animais , Células CHO , Bovinos , Doenças dos Bovinos/imunologia , Doenças dos Bovinos/patologia , Doenças dos Bovinos/virologia , Linhagem Celular , Vesículas Revestidas por Clatrina/metabolismo , Cricetulus , Endocitose , Células Epiteliais/virologia , Febre Aftosa/imunologia , Febre Aftosa/patologia , Febre Aftosa/virologia , Vírus da Febre Aftosa/genética , Vírus da Febre Aftosa/metabolismo , Expressão Gênica , Interações Hospedeiro-Patógeno , Humanos , Integrinas/genética , Integrinas/metabolismo , Histona Desmetilases com o Domínio Jumonji/antagonistas & inibidores , Histona Desmetilases com o Domínio Jumonji/genética , Histona Desmetilases com o Domínio Jumonji/metabolismo , Mutagênese , Mutação , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Receptores Virais/genética , Receptores Virais/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/metabolismo , Língua
20.
Virology ; 492: 38-52, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26896934

RESUMO

Foot-and-mouth disease virus (FMDV) utilizes four integrins (αvß1, αvß3, αvß6, and αvß8) as its primary cell receptor. During cell culture propagation, FMDV frequently adapts to use heparan sulfate (HS), and rarely utilizes an unidentified third receptor. Capsid mutations acquired by a soluble integrin resistant FMDV cause (i) adaptation to CHO-677 cells (ii) increased affinity to membrane-bound Jumonji C-domain containing protein 6 (JMJD6) (iii) induced JMJD6 re-localization from the cell surface and cytoplasm to the nucleus. Interestingly, pre-treatment of cells with N- and C-terminal JMJD6 antibodies or by simultaneous incubation of mutant virus with soluble JMJD6 (but not by treatment with HS or αvß6) impaired virus infectivity in cultured cells. JMJD6 and mutant virus co-purified by reciprocal co-immunoprecipitation. Molecular docking predictions suggested JMJD6 C-terminus interacts with mutated VP1 capsid protein. We conclude when specific VP1 mutations are displayed, JMJD6 contributes to FMDV infectivity and may be a previously unidentified FMDV receptor.


Assuntos
Proteínas do Capsídeo/química , Vírus da Febre Aftosa/genética , Integrinas/química , Histona Desmetilases com o Domínio Jumonji/química , Receptores Virais/química , Sequência de Aminoácidos , Animais , Células CHO , Células COS , Proteínas do Capsídeo/genética , Proteínas do Capsídeo/metabolismo , Bovinos , Chlorocebus aethiops , Cricetulus , Cristalografia por Raios X , Células Epiteliais/virologia , Vírus da Febre Aftosa/metabolismo , Expressão Gênica , Células HEK293 , Interações Hospedeiro-Patógeno , Humanos , Integrinas/genética , Integrinas/metabolismo , Histona Desmetilases com o Domínio Jumonji/genética , Histona Desmetilases com o Domínio Jumonji/metabolismo , Rim/virologia , Simulação de Acoplamento Molecular , Dados de Sequência Molecular , Estrutura Terciária de Proteína , Receptores Virais/genética , Receptores Virais/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Alinhamento de Sequência
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