Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 54
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Artigo em Inglês | MEDLINE | ID: mdl-39190197

RESUMO

PURPOSE: Positron emission tomography (PET) imaging of mutant huntingtin (mHTT) aggregates is a potential tool to monitor disease progression as well as the efficacy of candidate therapeutic interventions for Huntington's disease (HD). To date, the focus has been mainly on the investigation of 11C radioligands; however, favourable 18F radiotracers will facilitate future clinical translation. This work aimed at characterising the novel [18F]CHDI-650 PET radiotracer using a combination of in vivo and in vitro approaches in a mouse model of HD. METHODS: After characterising [18F]CHDI-650 using in vitro autoradiography, we assessed in vivo plasma and brain radiotracer stability as well as kinetics through dynamic PET imaging in the heterozygous (HET) zQ175DN mouse model of HD and wild-type (WT) littermates at 9 months of age. Additionally, we performed a head-to-head comparison study at 3 months with the previously published [11C]CHDI-180R radioligand. RESULTS: Plasma and brain radiometabolite profiles indicated a suitable metabolic profile for in vivo imaging of [18F]CHDI-650. Both in vitro autoradiography and in vivo [18F]CHDI-650 PET imaging at 9 months of age demonstrated a significant genotype effect (p < 0.0001) despite the poor test-retest reliability. [18F]CHDI-650 PET imaging at 3 months of age displayed higher differentiation between genotypes when compared to [11C]CHDI-180R. CONCLUSION: Overall, [18F]CHDI-650 allows for discrimination between HET and WT zQ175DN mice at 9 and 3 months of age. [18F]CHDI-650 represents the first suitable 18F radioligand to image mHTT aggregates in mice and its clinical evaluation is underway.

2.
Neurobiol Dis ; 181: 106095, 2023 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-36963694

RESUMO

Huntington's disease is an autosomal, dominantly inherited neurodegenerative disease caused by an expansion of the CAG repeats in exon 1 of the huntingtin gene. Neuronal degeneration and dysfunction that precedes regional atrophy result in the impairment of striatal and cortical circuits that affect the brain's large-scale network functionality. However, the evolution of these disease-driven, large-scale connectivity alterations is still poorly understood. Here we used resting-state fMRI to investigate functional connectivity changes in a mouse model of Huntington's disease in several relevant brain networks and how they are affected at different ages that follow a disease-like phenotypic progression. Towards this, we used the heterozygous (HET) form of the zQ175DN Huntington's disease mouse model that recapitulates aspects of human disease pathology. Seed- and Region-based analyses were performed at different ages, on 3-, 6-, 10-, and 12-month-old HET and age-matched wild-type mice. Our results demonstrate decreased connectivity starting at 6 months of age, most prominently in regions such as the retrosplenial and cingulate cortices, pertaining to the default mode-like network and auditory and visual cortices, part of the associative cortical network. At 12 months, we observe a shift towards decreased connectivity in regions such as the somatosensory cortices, pertaining to the lateral cortical network, and the caudate putamen, a constituent of the subcortical network. Moreover, we assessed the impact of distinct Huntington's Disease-like pathology of the zQ175DN HET mice on age-dependent connectivity between different brain regions and networks where we demonstrate that connectivity strength follows a non-linear, inverted U-shape pattern, a well-known phenomenon of development and normal aging. Conversely, the neuropathologically driven alteration of connectivity, especially in the default mode and associative cortical networks, showed diminished age-dependent evolution of functional connectivity. These findings reveal that in this Huntington's disease model, altered connectivity starts with cortical network aberrations which precede striatal connectivity changes, that appear only at a later age. Taken together, these results suggest that the age-dependent cortical network dysfunction seen in rodents could represent a relevant pathological process in Huntington's disease progression.


Assuntos
Doença de Huntington , Doenças Neurodegenerativas , Humanos , Camundongos , Animais , Lactente , Imageamento por Ressonância Magnética/métodos , Doença de Huntington/diagnóstico por imagem , Doença de Huntington/genética , Doença de Huntington/patologia , Doenças Neurodegenerativas/patologia , Encéfalo/patologia , Mapeamento Encefálico , Modelos Animais de Doenças
3.
Eur J Nucl Med Mol Imaging ; 50(1): 48-60, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36001116

RESUMO

PURPOSE: Huntington's disease is caused by a trinucleotide expansion in the HTT gene, which leads to aggregation of mutant huntingtin (mHTT) protein in the brain and neurotoxicity. Direct in vivo measurement of mHTT aggregates in human brain parenchyma is not yet possible. In this first-in-human study, we investigated biodistribution and dosimetry in healthy volunteers of [11C]CHDI-00485180-R ([11C]CHDI-180R) and [11C]CHDI-00485626 ([11C]CHDI-626), two tracers designed for PET imaging of aggregated mHTT in the brain that have been validated in preclinical models. METHODS: Biodistribution and radiation dosimetry studies were performed in 3 healthy volunteers (age 25.7 ± 0.5 years; 2 F) for [11C]CHDI-180R and in 3 healthy volunteers (age 35.3 ± 6.8 years; 2 F) for [11C]CHDI-626 using sequential whole-body PET-CT. Source organs were delineated in 3D using combined PET and CT data. Individual organ doses and effective doses were determined using OLINDA 2.1. RESULTS: There were no clinically relevant adverse events. The mean effective dose (ED) for [11C]CHDI-180R was 4.58 ± 0.65 µSv/MBq, with highest absorbed doses for liver (16.9 µGy/MBq), heart wall (15.9 µGy/MBq) and small intestine (15.8 µGy/MBq). Mean ED for [11C]CHDI-626 was 5.09 ± 0.06 µSv/MBq with the highest absorbed doses for the gallbladder (26.5 µGy/MBq), small intestine (20.4 µGy/MBq) and liver (19.6 µGy/MBq). Decay-corrected brain uptake curves showed promising kinetics for [11C]CHDI-180R, but for [11C]CHDI-626 an increasing signal over time was found, probably due to accumulation of a brain-penetrant metabolite. CONCLUSION: [11C]CHDI-180R and [11C]CHDI-626 are safe for in vivo PET imaging in humans. The estimated radiation burden is in line with most 11C-ligands. While [11C]CHDI-180R has promising kinetic properties in the brain, [11C]CHDI-626 is not suitable for human in vivo mHTT PET due to the possibility of a radiometabolite accumulating in brain parenchyma. TRIAL REGISTRATION: EudraCT number 2020-002129-27. CLINICALTRIALS: gov NCT05224115 (retrospectively registered).


Assuntos
Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Radiometria , Humanos , Adulto , Voluntários Saudáveis , Distribuição Tecidual , Tomografia por Emissão de Pósitrons/métodos
4.
Eur J Nucl Med Mol Imaging ; 49(4): 1166-1175, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34651228

RESUMO

PURPOSE: As several therapies aimed at lowering mutant huntingtin (mHTT) brain levels in Huntington's disease (HD) are currently being investigated, noninvasive positron emission tomography (PET) imaging of mHTT could be utilized to directly evaluate therapeutic efficacy and monitor disease progression. Here we characterized and longitudinally assessed the novel radioligand [11C]CHDI-626 for mHTT PET imaging in the zQ175DN mouse model of HD. METHODS: After evaluating radiometabolites and radioligand kinetics, we conducted longitudinal dynamic PET imaging at 3, 6, 9, and 13 months of age (M) in wild-type (WT, n = 17) and heterozygous (HET, n = 23) zQ175DN mice. Statistical analysis was performed to evaluate temporal and genotypic differences. Cross-sectional cohorts at each longitudinal time point were included for post-mortem [3H]CHDI-626 autoradiography. RESULTS: Despite fast metabolism and kinetics, the radioligand was suitable for PET imaging of mHTT. Longitudinal quantification could discriminate between genotypes already at premanifest stage (3 M), showing an age-associated increase in signal in HET mice in parallel with mHTT aggregate load progression, as supported by the post-mortem [3H]CHDI-626 autoradiography. CONCLUSION: With clinical evaluation underway, [11C]CHDI-626 PET imaging appears to be a suitable preclinical candidate marker to monitor natural HD progression and for the evaluation of mHTT-lowering therapies.


Assuntos
Doença de Huntington , Animais , Radioisótopos de Carbono , Estudos Transversais , Modelos Animais de Doenças , Humanos , Doença de Huntington/metabolismo , Camundongos , Tomografia por Emissão de Pósitrons/métodos
5.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 52(6): 960-965, 2021 Nov.
Artigo em Zh | MEDLINE | ID: mdl-34841762

RESUMO

OBJECTIVE: To explore the effect of nuclear factor-erythroid 2-related factor (Nrf2) pathway activation on hippocampal neuron damage in neonatal rats with bilirubin encephalopathy. METHODS: Neonatal rats were randomly assigned to a control group (Control), a model group (Model) and an Nrf2 activator TBHQ (tert-Butylhydroquinone) group (TBHQ), with 20 rats in each group. Bilirubin solution was injected through the cerebellomedullary cistern to establish the neonatal rat model of bilirubin encephalopathy. Neurobehavioral changes were observed in rats and the water content of the brain tissue was measured. Nissl staining was done to observe the damage of hippocampal neurons. TUNEL staining was used to observe the apoptosis of hippocampal neurons. Colorimetric analysis was done to determine the Caspase-3 activity in the hippocampus. The content of malondialdehyde (MDA) and reduced glutathione (GSH) and the activity of superoxide dismutase (SOD) in the hippocampus were examined by chemical analysis. qRT-PCR and Western blot were done to measure the expression of Nrf2 and heme oxygenase-l (HO-1) mRNA and proteins in the hippocampus. RESULTS: After injection of bilirubin into the cerebellomedullary cistern, the young rats in the Model group and the TBHQ group showed different degrees of neurological abnormalities, while those in the control group showed no significant neurobehavioral abnormalities. Compared with the Control group, the Model group had severe neuronal damage, and the water content of brain tissue, the apoptosis of hippocampal neurons, the activity of Caspase-3 and the content of MDA content significantly increased ( P<0.01), while the SOD activity, GSH content, the expression of Nrf2 and HO-1 mRNA and proteins significantly decreased ( P<0.05). Compared with the Model group, neuronal damage was improved in the TBHQ group, and the water content of brain tissue, apoptosis of hippocampal neurons, activity of Caspase-3 and MDA content were all significantly reduced ( P<0.01), while SOD activity, GSH content and the expression of Nrf2 and HO-1 mRNA and proteins were significantly increased ( P<0.05). CONCLUSION: Activation of the Nrf2 pathway can improve hippocampal neuronal damage in neonatal rats with bilirubin encephalopathy and inhibit neuronal apoptosis and the oxidation reaction.


Assuntos
Kernicterus , Fator 2 Relacionado a NF-E2 , Animais , Animais Recém-Nascidos , Hipocampo , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Neurônios/metabolismo , Estresse Oxidativo , Ratos , Transdução de Sinais
6.
Bioorg Med Chem Lett ; 30(14): 127240, 2020 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-32527542

RESUMO

The (Z)-fluoro-olefin amide bioisosteric replacement is an effective tool for addressing various shortcomings of the parent amide. In an effort to fine tune ADME properties of BACE1 preclinical candidate AM-6494, a series of structurally distinct (Z)-fluoro-olefin containing analogs was developed that culminated in compound 15. Herein, we detail design considerations, synthetic challenges, structure activity relationship (SAR) studies, and in vivo properties of an advanced compound in this novel series of BACE1 inhibitors.


Assuntos
Alcenos/farmacologia , Amidas/farmacologia , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Desenvolvimento de Medicamentos , Inibidores Enzimáticos/farmacologia , Hidrocarbonetos Fluorados/farmacologia , Alcenos/síntese química , Alcenos/química , Amidas/síntese química , Amidas/química , Secretases da Proteína Precursora do Amiloide/metabolismo , Ácido Aspártico Endopeptidases/metabolismo , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Células HEK293 , Humanos , Hidrocarbonetos Fluorados/síntese química , Hidrocarbonetos Fluorados/química , Conformação Molecular , Estereoisomerismo , Relação Estrutura-Atividade
7.
Nature ; 504(7480): 437-40, 2013 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-24226772

RESUMO

Glucose homeostasis is a vital and complex process, and its disruption can cause hyperglycaemia and type II diabetes mellitus. Glucokinase (GK), a key enzyme that regulates glucose homeostasis, converts glucose to glucose-6-phosphate in pancreatic ß-cells, liver hepatocytes, specific hypothalamic neurons, and gut enterocytes. In hepatocytes, GK regulates glucose uptake and glycogen synthesis, suppresses glucose production, and is subject to the endogenous inhibitor GK regulatory protein (GKRP). During fasting, GKRP binds, inactivates and sequesters GK in the nucleus, which removes GK from the gluconeogenic process and prevents a futile cycle of glucose phosphorylation. Compounds that directly hyperactivate GK (GK activators) lower blood glucose levels and are being evaluated clinically as potential therapeutics for the treatment of type II diabetes mellitus. However, initial reports indicate that an increased risk of hypoglycaemia is associated with some GK activators. To mitigate the risk of hypoglycaemia, we sought to increase GK activity by blocking GKRP. Here we describe the identification of two potent small-molecule GK-GKRP disruptors (AMG-1694 and AMG-3969) that normalized blood glucose levels in several rodent models of diabetes. These compounds potently reversed the inhibitory effect of GKRP on GK activity and promoted GK translocation both in vitro (isolated hepatocytes) and in vivo (liver). A co-crystal structure of full-length human GKRP in complex with AMG-1694 revealed a previously unknown binding pocket in GKRP distinct from that of the phosphofructose-binding site. Furthermore, with AMG-1694 and AMG-3969 (but not GK activators), blood glucose lowering was restricted to diabetic and not normoglycaemic animals. These findings exploit a new cellular mechanism for lowering blood glucose levels with reduced potential for hypoglycaemic risk in patients with type II diabetes mellitus.


Assuntos
Proteínas de Transporte/antagonistas & inibidores , Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/farmacologia , Hipoglicemiantes/uso terapêutico , Proteínas Adaptadoras de Transdução de Sinal , Animais , Glicemia/metabolismo , Proteínas de Transporte/metabolismo , Núcleo Celular/enzimologia , Cristalografia por Raios X , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/enzimologia , Modelos Animais de Doenças , Hepatócitos , Humanos , Hiperglicemia/sangue , Hiperglicemia/tratamento farmacológico , Hiperglicemia/enzimologia , Hipoglicemiantes/química , Fígado/citologia , Fígado/enzimologia , Fígado/metabolismo , Masculino , Modelos Moleculares , Especificidade de Órgãos , Fosforilação/efeitos dos fármacos , Piperazinas/química , Piperazinas/metabolismo , Piperazinas/farmacologia , Piperazinas/uso terapêutico , Ligação Proteica/efeitos dos fármacos , Transporte Proteico/efeitos dos fármacos , Ratos , Ratos Wistar , Sulfonamidas/química , Sulfonamidas/metabolismo , Sulfonamidas/farmacologia , Sulfonamidas/uso terapêutico
8.
Sensors (Basel) ; 19(21)2019 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-31671894

RESUMO

In this paper, an onboard vision-based system for the autonomous landing of a low-cost quadrotor is presented. A novel landing pad with different optical markers sizes is carefully designed to be robustly recognized at different distances. To provide reliable pose information in a GPS (Global Positioning System)-denied environment, a vision algorithm for real-time landing pad recognition and pose estimation is implemented. The dynamic model of the quadrotor is established and a system scheme for autonomous landing control is presented. A series of autonomous flights have been successfully performed, and a video of the experiment is available online. The efficiency and accuracy of the presented vision-based system is demonstrated by using its position and attitude estimates as control inputs for the autonomous landing of a self-customized quadrotor.

9.
Med Sci Monit ; 23: 4014-4020, 2017 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-28822209

RESUMO

BACKGROUND Developing a simple and efficient method of obtaining primary cultured VSMCs is necessary for basic cardiovascular research. MATERIAL AND METHODS The procedure of our new method mainly includes 6 steps: isolation of the aortic artery, removal of the fat tissue around the artery, separation of the media, cutting the media into small tissue blocks, transferring the tissue blocks to cell culture plates, and incubation until the cells reach confluence. The cells were identified as VSMCs by morphology and immunofluorescence. Then, VSMCs obtained by this new tissue explants method, the traditional tissue explants method, the enzyme digestion method, and A7r5 cell line were divided into 4 groups. The purity of cells was test by multiple fluorescent staining. Western blotting was used to investigate the phenotype of VSMCs obtained by different methods. RESULTS Cells began to grow out at about 8 days and became relatively confluent within 16 days. Compared with VSMCs from the traditional tissue explants method and enzyme digestion method or A7r5 cell line, VSMCs obtained by our method showed higher purity and manifested a more "contractile" phenotype characteristic. CONCLUSIONS We have conquered the disadvantages in the previous primary culture methods and established a simple and reliable way to isolate and culture rat aortic VSMCs with high purity and stability.


Assuntos
Aorta/citologia , Técnicas de Cultura de Células/métodos , Músculo Liso Vascular/citologia , Miócitos de Músculo Liso/citologia , Animais , Células Cultivadas , Cultura Primária de Células , Ratos , Ratos Sprague-Dawley
10.
J Cardiovasc Pharmacol ; 67(6): 482-90, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26836482

RESUMO

The beneficial effect of Chinese rice wine on atherosclerosis has been proved, but the exact components that have the cardiovascular protective effect are still unknown. This study aimed to explore the exact ingredients in Chinese rice wine that could inhibit homocysteine (Hcy)-induced vascular smooth muscle cell (VSMC) proliferation and migration. VSMCs were divided into 7 groups: control, Hcy (1 mmol/L), Hcy + oligosaccharide, Hcy + polypeptides, Hcy + polyphenols, Hcy + alcohol, and Hcy + Chinese rice wine. methyl thiazolyl tetrazolium (MTT) assay, Transwell chambers, and wound-healing assay were used to test the proliferation and migratory ability of the VSMCs. Western blot and gelatin zymography were used to investigate the expressions and activities of metal matrix proteinase 2/9 (MMP-2/9) and tissue inhibitor of metalloproteinase 2 (TIMP-2) in VSMCs. Polypeptides and polyphenols in the Chinese rice wine reduced the proliferation and migration ability of the VSMCs. Furthermore, they also decreased the expression and activity of MMP-2/9 but had no obvious impact on the expression of TIMP-2 in each group. This study further confirms that polypeptides and polyphenols in the Chinese rice wine could inhibit Hcy-induced proliferation and migration of VSMCs and maintain the balance between matrix metalloproteinases (MMPs) and TIMPs.


Assuntos
Homocisteína/antagonistas & inibidores , Músculo Liso Vascular/efeitos dos fármacos , Oryza , Peptídeos/farmacologia , Polifenóis/farmacologia , Animais , Movimento Celular , Proliferação de Células , Metaloproteinase 2 da Matriz/biossíntese , Metaloproteinase 9 da Matriz/biossíntese , Oligossacarídeos , Ratos , Ratos Sprague-Dawley , Inibidor Tecidual de Metaloproteinase-2/biossíntese , Vinho
11.
Bioorg Med Chem ; 24(10): 2215-34, 2016 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-27085672

RESUMO

One of the challenges for targeting B-Raf(V600E) with small molecule inhibitors had been achieving adequate selectivity over the wild-type protein B-Raf(WT), as inhibition of the latter has been associated with hyperplasia in normal tissues. Recent studies suggest that B-Raf inhibitors inducing the 'DFG-in/αC-helix-out' conformation (Type IIB) likely will exhibit improved selectivity for B-Raf(V600E). To explore this hypothesis, we transformed Type IIA inhibitor (1) into a series of Type IIB inhibitors (sulfonamides and sulfamides 4-6) and examined the SAR. Three selectivity indices were introduced to facilitate the analyses: the B-Raf(V600E)/B-Raf(WT) biochemical ((b)S), cellular ((c)S) selectivity, and the phospho-ERK activation ((p)A). Our data indicates that α-branched sulfonamides and sulfamides show higher selectivities than the linear derivatives. We rationalized this finding based on analysis of structural information from the literature and provided evidence for a monomeric B-Raf-inhibitor complex previously hypothesized to be responsible for the desired B-Raf(V600E) selectivity.


Assuntos
Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Purinas/química , Purinas/farmacologia , Piridinas/química , Piridinas/farmacologia , Aminação , Cristalografia por Raios X , Desenho de Fármacos , Humanos , Modelos Moleculares , Mutação Puntual , Conformação Proteica em alfa-Hélice/efeitos dos fármacos , Proteínas Proto-Oncogênicas B-raf/química , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas B-raf/metabolismo , Relação Estrutura-Atividade
12.
Sci Rep ; 14(1): 17261, 2024 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-39068226

RESUMO

To address the issue of electronic equipment failure inside the instrument compartment due to aerodynamic heating during high-speed flight. Combining the heat transfer characteristics of phase change materials, a new instrument compartment structure was proposed as the research subject based on phase change materials. While studying the heat transfer characteristics of this structure, one-dimensional phase change heat transfer theoretical model was constructed based on the Lightfoot integral equation method, and the corresponding analytical solution was obtained. To explore the temperature change law of the instrument compartment structure and verify the rationality of the theoretical model, the new thermal experiment was carried out for the instrument compartment structure. Compared with the aluminum alloy instrument compartment structure, the experimental results show that the instrument compartment structure design based on phase change materials could effectively reduce the temperature of the structure itself, and the experimental data are in good agreement with the theoretical calculation results, which verified the rationality of the theoretical model and provided a scientific basis for the practical application of phase change materials in instrument compartment structures.

13.
J Nucl Med ; 64(10): 1581-1587, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37591545

RESUMO

Huntington disease (HD) is a neurodegenerative disorder caused by an expanded polyglutamine (CAG) trinucleotide expansion in the huntingtin (HTT) gene that encodes the mutant huntingtin protein (mHTT). Visualization and quantification of cerebral mHTT will provide a proxy for target engagement and a means to evaluate therapeutic interventions aimed at lowering mHTT in the brain. Here, we validated the novel radioligand 11C-labeled 6-(5-((5-methoxypyridin-2-yl)methoxy)benzo[d]oxazol-2-yl)-2-methylpyridazin-3(2H)-one (11C-CHDI-180R) using PET imaging to quantify cerebral mHTT aggregates in a macaque model of HD. Methods: Rhesus macaques received MRI-guided intrastriatal delivery of a mixture of AAV2 and AAV2.retro viral vectors expressing an HTT fragment bearing 85 CAG repeats (85Q, n = 5), a control HTT fragment bearing 10 CAG repeats (10Q, n = 4), or vector diluent only (phosphate-buffered saline, n = 5). Thirty months after surgery, 90-min dynamic PET/CT imaging was used to investigate 11C-CHDI-180R brain kinetics, along with serial blood sampling to measure input function and stability of the radioligand. The total volume of distribution was calculated using a 2-tissue-compartment model as well as Logan graphical analysis for regional quantification. Immunostaining for mHTT was performed to corroborate the in vivo findings. Results: 11C-CHDI-180R displayed good metabolic stability (51.4% ± 4.0% parent in plasma at 60 min after injection). Regional time-activity curves displayed rapid uptake and reversible binding, which were described by a 2-tissue-compartment model. Logan graphical analysis was associated with the 2-tissue-compartment model (r 2 = 0.96, P < 0.0001) and used to generate parametric volume of distribution maps. Compared with controls, animals administered the 85Q fragment exhibited significantly increased 11C-CHDI-180R binding in several cortical and subcortical brain regions (group effect, P < 0.0001). No difference in 11C-CHDI-180R binding was observed between buffer and 10Q animals. The presence of mHTT aggregates in the 85Q animals was confirmed histologically. Conclusion: We validated 11C-CHDI-180R as a radioligand to visualize and quantify mHTT aggregated species in a HD macaque model. These findings corroborate our previous work in rodent HD models and show that 11C-CHDI-180R is a promising tool to assess the mHTT aggregate load and the efficacy of therapeutic strategies.


Assuntos
Doença de Huntington , Animais , Doença de Huntington/metabolismo , Proteína Huntingtina/genética , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Macaca mulatta/metabolismo , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Tomografia por Emissão de Pósitrons , Modelos Animais de Doenças
14.
Sci Rep ; 13(1): 10194, 2023 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-37353500

RESUMO

Huntington's disease (HD) is a neurodegenerative disorder caused by expanded (≥ 40) glutamine-encoding CAG repeats in the huntingtin gene, which leads to dysfunction and death of predominantly striatal and cortical neurons. While the genetic profile and clinical signs and symptoms of the disease are better known, changes in the functional architecture of the brain, especially before the clinical expression becomes apparent, are not fully and consistently characterized. In this study, we sought to uncover functional changes in the brain in the heterozygous (HET) zQ175 delta-neo (DN) mouse model at 3, 6, and 10 months of age, using resting-state functional magnetic resonance imaging (RS-fMRI). This mouse model shows molecular, cellular and circuitry alterations that worsen through age. Motor function disturbances are manifested in this model at 6 and 10 months of age. Specifically, we investigated, longitudinally, changes in co-activation patterns (CAPs) that are the transient states of brain activity constituting the resting-state networks (RSNs). Most robust changes in the temporal properties of CAPs occurred at the 10-months time point; the durations of two anti-correlated CAPs, characterized by simultaneous co-activation of default-mode like network (DMLN) and co-deactivation of lateral-cortical network (LCN) and vice-versa, were reduced in the zQ175 DN HET animals compared to the wild-type mice. Changes in the spatial properties, measured in terms of activation levels of different brain regions, during CAPs were found at all three ages and became progressively more pronounced at 6-, and 10 months of age. We then assessed the cross-validated predictive power of CAP metrics to distinguish HET animals from controls. Spatial properties of CAPs performed significantly better than the chance level at all three ages with 80% classification accuracy at 6 and 10 months of age.


Assuntos
Doença de Huntington , Camundongos , Animais , Doença de Huntington/diagnóstico por imagem , Doença de Huntington/genética , Doença de Huntington/metabolismo , Encéfalo/metabolismo , Heterozigoto , Corpo Estriado/metabolismo , Neurônios/metabolismo , Modelos Animais de Doenças
15.
J Med Chem ; 66(1): 641-656, 2023 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-36548390

RESUMO

Therapeutic interventions are being developed for Huntington's disease (HD), a hallmark of which is mutant huntingtin protein (mHTT) aggregates. Following the advancement to human testing of two [11C]-PET ligands for aggregated mHTT, attributes for further optimization were identified. We replaced the pyridazinone ring of CHDI-180 with a pyrimidine ring and minimized off-target binding using brain homogenate derived from Alzheimer's disease patients. The major in vivo metabolic pathway via aldehyde oxidase was blocked with a 2-methyl group on the pyrimidine ring. A strategically placed ring-nitrogen on the benzoxazole core ensured high free fraction in the brain without introducing efflux. Replacing a methoxy pendant with a fluoro-ethoxy group and introducing deuterium atoms suppressed oxidative defluorination and accumulation of [18F]-signal in bones. The resulting PET ligand, CHDI-650, shows a rapid brain uptake and washout profile in non-human primates and is now being advanced to human testing.


Assuntos
Doença de Huntington , Tomografia por Emissão de Pósitrons , Animais , Humanos , Proteína Huntingtina/genética , Proteína Huntingtina/metabolismo , Ligantes , Tomografia por Emissão de Pósitrons/métodos , Doença de Huntington/diagnóstico por imagem , Doença de Huntington/tratamento farmacológico , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo
16.
J Med Chem ; 66(18): 13205-13246, 2023 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-37712656

RESUMO

Huntington's disease (HD) is caused by an expanded CAG trinucleotide repeat in exon 1 of the huntingtin (HTT) gene. We report the design of a series of HTT pre-mRNA splicing modulators that lower huntingtin (HTT) protein, including the toxic mutant huntingtin (mHTT), by promoting insertion of a pseudoexon containing a premature termination codon at the exon 49-50 junction. The resulting transcript undergoes nonsense-mediated decay, leading to a reduction of HTT mRNA transcripts and protein levels. The starting benzamide core was modified to pyrazine amide and further optimized to give a potent, CNS-penetrant, and orally bioavailable HTT-splicing modulator 27. This compound reduced canonical splicing of the HTT RNA exon 49-50 and demonstrated significant HTT-lowering in both human HD stem cells and mouse BACHD models. Compound 27 is a structurally diverse HTT-splicing modulator that may help understand the mechanism of adverse effects such as peripheral neuropathy associated with branaplam.

17.
Bioorg Med Chem Lett ; 22(17): 5714-20, 2012 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-22832322

RESUMO

Phosphoinositide 3-kinase (PI3K) is an important target in oncology due to the deregulation of the PI3K/Akt signaling pathway in a wide variety of tumors. A series of 4-amino-6-methyl-1,3,5-triazine sulfonamides were synthesized and evaluated as inhibitors of PI3K. The synthesis, in vitro biological activities, pharmacokinetic and in vivo pharmacodynamic profiling of these compounds are described. The most promising compound from this investigation (compound 3j) was found to be a pan class I PI3K inhibitor with a moderate (>10-fold) selectivity over the mammalian target of rapamycin (mTOR) in the enzyme assay. In a U87 MG cellular assay measuring phosphorylation of Akt, compound 3j displayed low double digit nanomolar IC(50) and exhibited good oral bioavailability in rats (F(oral)=63%). Compound 3j also showed a dose dependent reduction in the phosphorylation of Akt in a U87 tumor pharmacodynamic model with a plasma EC(50)=193 nM (91 ng/mL).


Assuntos
Neoplasias/tratamento farmacológico , Inibidores de Fosfoinositídeo-3 Quinase , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Sulfonamidas/química , Sulfonamidas/farmacologia , Serina-Treonina Quinases TOR/antagonistas & inibidores , Animais , Antineoplásicos/química , Antineoplásicos/farmacocinética , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Sítios de Ligação , Linhagem Celular Tumoral , Cristalografia por Raios X , Feminino , Humanos , Camundongos , Simulação de Acoplamento Molecular , Neoplasias/enzimologia , Neoplasias/metabolismo , Fosfatidilinositol 3-Quinases/química , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacocinética , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Transdução de Sinais/efeitos dos fármacos , Relação Estrutura-Atividade , Sulfonamidas/farmacocinética , Sulfonamidas/uso terapêutico , Serina-Treonina Quinases TOR/metabolismo , Triazinas/química , Triazinas/farmacocinética , Triazinas/farmacologia , Triazinas/uso terapêutico
18.
Cardiovasc Drugs Ther ; 26(5): 375-82, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22918601

RESUMO

OBJECTIVES: To provide evidence that rosuvastatin may improve insulin-resistance and inhibit atherogenesis by modulating insulin signaling, and whether this effect occurs beyond its plasma cholesterol-lowering effect. METHODS: Thirty-two 6-week-old low-density lipoprotein receptor deficient mice were randomized into 4 groups (n = 8 in each group): Normal control group (NC); High fat and high fructose diet group (HFF); HFF plus rosuvastatin group (HFFR); HFFR plus mevalonic acid group (HFFRMA). After 12 weeks, we measured fasting blood sugar, fasting insulin and cholesterol levels; the morphological concentrations of the aorta and aortic sinus; the expression of insulin receptor substrate 2, phosphorylated insulin receptor substrate 2, protein kinase B, phosphorylated protein kinase B and the glucose transporter 4 in the liver. RESULTS: Compared with other groups, fasting blood sugar and fasting insulin increased significantly in HFF group. Furthermore, HFF group had an increase in the morphological concentrations of the aorta and aortic sinus, but there was a significant decrease in the HFFRMA group and the HFFR group. Moreover, there was a high expression of insulin receptor substrate 2, phosphorylated insulin receptor substrate 2, protein kinase B, phosphorylated protein kinase B and the glucose transporter 4 in the HFFRMA and HFFR groups, but a low expression in the HFF group. No significant differences regarding each afore-mentioned index was observed in the HFFR and HFFRMA groups. CONCLUSIONS: Our data show that rosuvastatin may improve insulin-resistance and inhibit atherogenesis in HFF-fed mice by partially reversing the decrease in the insulin stimulated insulin receptor substrate 2/Phosphatidylinositol 3-kinase/protein kinase B/glucose transporter 4 pathway in the liver, and that this effect is independent of its cholesterol-lowering effect.


Assuntos
Aterosclerose/tratamento farmacológico , Fluorbenzenos/uso terapêutico , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Resistência à Insulina , Pirimidinas/uso terapêutico , Sulfonamidas/uso terapêutico , Animais , Aterosclerose/metabolismo , Aterosclerose/patologia , Dieta , Fluorbenzenos/farmacologia , Frutose , Transportador de Glucose Tipo 4/metabolismo , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Insulina/metabolismo , Proteínas Substratos do Receptor de Insulina/metabolismo , Lipídeos/sangue , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Camundongos , Camundongos Knockout , Proteínas Proto-Oncogênicas c-akt/metabolismo , Pirimidinas/farmacologia , Receptores de LDL/deficiência , Receptores de LDL/genética , Rosuvastatina Cálcica , Sulfonamidas/farmacologia
19.
Exp Ther Med ; 23(2): 115, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34970338

RESUMO

In-stent restenosis (ISR) can pose serious challenges for cardiologists following coronary stent implantation. Early identification of patients at high risk of ISR is considered to be effective for its prevention. However, factors that can reliably predict the risk of ISR remain elusive at present. The present study aimed to investigate the possible association between plasma long non-coding RNA (lncRNA) levels and ISR. A total of 410 patients with single-vessel lesion who received drug-eluting stents (DES) were included in the present study. After 12-36 months of follow-up, coronary angiography was performed and ISR was defined as >50% diameter stenosis at follow-up. RT-qPCR was used to measure lncRNA expression. Expression of the lncRNA RNA antisense non-coding RNA at the INK4 locus (ANRIL) was found to be upregulated whereas the lncRNA homeobox A11 antisense (HOXA11-AS) was downregulated in the plasma of patients with ISR compared with that from patients without ISR (P<0.001). Logistic regression analysis revealed that ANRIL [odds ratio (OR)=2.95; 95% confidence interval (CI)=1.68-8.08] was an independent risk factor for ISR, whilst HOXA11-AS (OR=0.58; 95% CI=0.48-0.71) was found to be an independent protective factor for ISR. Receiver operating characteristic (ROC) analysis demonstrated that high ANRIL expression [area under the ROC (auROC)=0.755; 95% CI=0.702-0.803] and low HOXA11-AS levels (auROC=0.712; 95% CI=0.657-0.763) predicted a high risk for ISR, and the combined score of ANRIL and HOXA11-AS (auROC=0.844; 95% CI=0.798-0.884) was more efficient at predicting ISR than either ANRIL or HOXA11-AS alone (P<0.001). In conclusion, increased ANRIL and decreased HOXA11-AS expressions were associated with ISR. However, combined ANRIL and HOXA11-AS plasma levels proved to be more effective at predicting ISR compared with either ANRIL or HOXA11-AS alone, suggesting that the multiplex detection of lncRNAs could be used to predict ISR in the future.

20.
J Nucl Med ; 63(6): 942-947, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-34531262

RESUMO

Synaptic dysfunction is a primary mechanism underlying Huntington disease (HD) progression. This study investigated changes in synaptic vesicle glycoprotein 2A (SV2A) density by means of 11C-UCB-J small-animal PET imaging in the central nervous system of mice with HD. Methods: Dynamic 11C-UCB-J small-animal PET imaging was performed at clinically relevant disease stages (at 3, 7, 10, and 16 mo) in the heterozygous knock-in Q175DN mouse model of HD and wild-type littermates (16-18 mice per genotype and time point). Cerebral 11C-UCB-J analyses were performed to assess genotypic differences during presymptomatic (3 mo) and symptomatic (7-16 mo) disease stages. 11C-UCB-J binding in the spinal cord was quantified at 16 mo. 3H-UCB-J autoradiography and SV2A immunofluorescence were performed postmortem in mouse and human brain tissues. Results:11C-UCB-J binding was lower in symptomatic heterozygous mice than in wild-type littermates in parallel with disease progression (7 and 10 mo: P < 0.01; 16 mo: P < 0.0001). Specific 11C-UCB-J binding was detectable in the spinal cord, with symptomatic heterozygous mice displaying a significant reduction (P < 0.0001). 3H-UCB-J autoradiography and SV2A immunofluorescence corroborated the in vivo measurements demonstrating lower SV2A in heterozygous mice (P < 0.05). Finally, preliminary analysis of SV2A in the human brain postmortem suggested lower SV2A in HD gene carriers than in controls without dementia. Conclusion:11C-UCB-J PET detected SV2A deficits during symptomatic disease in heterozygous mice in both the brain and the spinal cord and therefore may be suitable as a novel marker of synaptic integrity widely distributed in the central nervous system. On clinical application, 11C-UCB-J PET imaging may have promise for SV2A measurement in patients with HD during disease progression and after disease-modifying therapeutic strategies.


Assuntos
Doença de Huntington , Animais , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Progressão da Doença , Humanos , Doença de Huntington/diagnóstico por imagem , Doença de Huntington/metabolismo , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Camundongos , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Tomografia por Emissão de Pósitrons/métodos , Piridinas/metabolismo , Vesículas Sinápticas/metabolismo
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa