RESUMO
Background: Immunotherapy has profoundly changed the landscape of cancer management and represented the most significant breakthrough. Yet, it is a formidable challenge that the majority of cancers - the so-called "cold" tumors - poorly respond to immunotherapy. To find a general immunoregulatory modality that can be applied to a broad spectrum of cancers is an urgent need. Methods: Magnetic hyperthermia (MHT) possesses promise in cancer therapy. We develop a safe and effective therapeutic strategy by using magnetism-mediated targeting MHT-immunotherapy in "cold" colon cancer. A magnetic liposomal system modified with cell-penetrating TAT peptide was developed for targeted delivery of a CSF1R inhibitor (BLZ945), which can block the CSF1-CSF1R pathway and reduce M2 macrophages. The targeted delivery strategy is characterized by its magnetic navigation and TAT-promoting intratumoral penetration. Results: The liposomes (termed TAT-BLZmlips) can induce ICD and cause excessive CRT exposure on the cell surface, which transmits an "eat-me" signal to DCs to elicit immunity. The combination of MHT and BLZ945 can repolarize M2 macrophages in the tumor microenvironment to relieve immunosuppression, normalize the tumor blood vessels, and promote T-lymphocyte infiltration. The antitumor effector CD8+ T cells were increased after treatment. Conclusion: This work demonstrated that TAT-BLZmlips with magnetic navigation and MHT can remodel tumor microenvironment and activate immune responses and memory, thus inhibiting tumor growth and recurrence.
Assuntos
Neoplasias do Colo/terapia , Terapia Combinada/métodos , Hipertermia , Imunoterapia/métodos , Lipossomos/química , Magnetoterapia/métodos , Nanopartículas de Magnetita/química , Receptores de Fator Estimulador das Colônias de Granulócitos e Macrófagos/antagonistas & inibidores , Animais , Apoptose/efeitos dos fármacos , Apoptose/efeitos da radiação , Benzotiazóis/farmacocinética , Benzotiazóis/farmacologia , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/metabolismo , Linhagem Celular Tumoral , Neoplasias do Colo/diagnóstico por imagem , Neoplasias do Colo/imunologia , Feminino , Humanos , Lipossomos/metabolismo , Lipossomos/efeitos da radiação , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Recidiva Local de Neoplasia/metabolismo , Recidiva Local de Neoplasia/terapia , Ácidos Picolínicos/farmacocinética , Ácidos Picolínicos/farmacologia , Ratos , Microambiente Tumoral/efeitos dos fármacos , Macrófagos Associados a Tumor/efeitos dos fármacos , Macrófagos Associados a Tumor/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Starting from lead compound 4, the 1,4-oxazine headgroup was optimized to improve potency and brain penetration. Focusing at the 6-position of the 5-amino-1,4-oxazine, the insertion of a Me and a CF3 group delivered an excellent pharmacological profile with a pKa of 7.1 and a very low P-gp efflux ratio enabling high central nervous system (CNS) penetration and exposure. Various synthetic routes to access BACE1 inhibitors bearing a 5-amino-6-methyl-6-(trifluoromethyl)-1,4-oxazine headgroup were investigated. Subsequent optimization of the P3 fragment provided the highly potent N-(3-((3R,6R)-5-amino-3,6-dimethyl-6-(trifluoromethyl)-3,6-dihydro-2H-1,4-oxazin-3-yl)-4-fluorophenyl)-5-cyano-3-methylpicolinamide 54 (NB-360), able to reduce significantly Aß levels in mice, rats, and dogs in acute and chronic treatment regimens.
Assuntos
Secretases da Proteína Precursora do Amiloide/metabolismo , Inibidores Enzimáticos/síntese química , Ácidos Picolínicos/síntese química , Tiazinas/síntese química , Doença de Alzheimer/tratamento farmacológico , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Peptídeos beta-Amiloides/metabolismo , Animais , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Ácido Aspártico Endopeptidases/metabolismo , Sítios de Ligação , Encéfalo/metabolismo , Cristalografia por Raios X , Cães , Inibidores Enzimáticos/metabolismo , Inibidores Enzimáticos/uso terapêutico , Meia-Vida , Humanos , Camundongos , Simulação de Dinâmica Molecular , Oxazinas/química , Ácidos Picolínicos/farmacocinética , Ácidos Picolínicos/uso terapêutico , Ratos , Relação Estrutura-Atividade , Tiazinas/farmacocinética , Tiazinas/uso terapêuticoRESUMO
Vadadustat is a hypoxia-inducible factor prolyl hydroxylase inhibitor in development for the treatment of anemia of chronic kidney disease. This phase 1, open-label, parallel-group, single-dose study evaluated the pharmacokinetics of 450-mg vadadustat in adults with moderate hepatic impairment (Child-Pugh class B) vs those with normal hepatic function. Primary end points were area under the plasma concentration-time curve (AUC) from dosing to last concentration and to infinity, as well as maximum concentration (Cmax ); additional pharmacokinetic parameters included time to Cmax (Tmax ) and half-life. Safety and tolerability were also assessed. All enrolled participants (n = 16) completed the study. Demographics were similar in both groups (overall, 100% White; 62.5% female; mean age, 59.2 years). Vadadustat plasma exposure was higher in the moderate hepatic impairment group, whereas maximum concentration was similar between groups. Point estimates of the hepatic impairment : normal geometric mean ratios (90% confidence interval) for AUC from dosing to last concentration, AUC from dosing to infinity, and Cmax were 1.05 (0.82-1.35), 1.06 (0.82-1.36), and 1.02 (0.79-1.32), respectively. Mean elimination half-life was 5.8 and 7.8 hours in the normal and hepatic impairment groups, respectively. Treatment-emergent adverse events were mostly mild in severity, and vadadustat was generally well tolerated. In conclusion, moderate hepatic impairment did not significantly impact vadadustat systemic exposure, and mild hepatic impairment is unlikely to alter vadadustat exposure.
Assuntos
Jejum/sangue , Glicina/análogos & derivados , Hepatopatias/fisiopatologia , Ácidos Picolínicos/administração & dosagem , Inibidores de Prolil-Hidrolase/administração & dosagem , Administração Oral , Idoso , Área Sob a Curva , Feminino , Glicina/administração & dosagem , Glicina/efeitos adversos , Glicina/farmacocinética , Humanos , Masculino , Pessoa de Meia-Idade , Ácidos Picolínicos/efeitos adversos , Ácidos Picolínicos/farmacocinética , Inibidores de Prolil-Hidrolase/efeitos adversos , Inibidores de Prolil-Hidrolase/farmacocinéticaRESUMO
The design and discovery of a new series of (5-alkynyl-3-hydroxypicolinoyl)glycine inhibitors of prolyl hydroxylase (PHD) are described. These compounds showed potent in vitro inhibitory activity toward PHD2 in a fluorescence polarization-based assay. Remarkably, oral administration of 17, with an IC50 of 64.2 nM toward PHD2, was found to stabilize HIF-α, elevate erythropoietin (EPO), and alleviate anemia in a cisplatin-induced anemia mouse model with an oral dose of 25 mg/kg. Rat and dog studies showed that 17 has good pharmacokinetic properties, with oral bioavailabilities of 55.7 and 54.0%, respectively, and shows excellent safety profiles even at a high dose of 200 mg/kg in these animals. Based on these results, 17 is currently being evaluated in a phase I clinical trial for anemia.
Assuntos
Anemia/tratamento farmacológico , Glicina/análogos & derivados , Glicina/uso terapêutico , Ácidos Picolínicos/uso terapêutico , Inibidores de Prolil-Hidrolase/uso terapêutico , Anemia/induzido quimicamente , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Cisplatino , Cães , Desenho de Fármacos , Eritropoetina/metabolismo , Feminino , Glicina/farmacocinética , Glicina/toxicidade , Masculino , Camundongos Endogâmicos C57BL , Estrutura Molecular , Ácidos Picolínicos/síntese química , Ácidos Picolínicos/farmacocinética , Ácidos Picolínicos/toxicidade , Inibidores de Prolil-Hidrolase/síntese química , Inibidores de Prolil-Hidrolase/farmacocinética , Inibidores de Prolil-Hidrolase/toxicidade , Ratos Sprague-Dawley , Relação Estrutura-AtividadeRESUMO
PURPOSE: A technological gap exists for the iron (Fe) fortification of difficult-to-fortify products, such as wet and acid food products containing polyphenols, with stable and bioavailable Fe. Fe picolinate, a novel food ingredient, was found to be stable over time in this type of matrix. The objective of this study was to measure the Fe bioavailability of Fe picolinate in a complementary fruit yogurt. METHODS: The bioavailability of Fe picolinate was determined using stable iron isotopes in a double blind, randomized cross-over design in non-anemic Swiss women (n = 19; 25.1 ± 4.6 years). Fractional Fe absorption was measured from Fe picolinate (2.5 mg 57Fe per serving in two servings given morning and afternoon) and from Fe sulfate (2.5 mg 54Fe per serving in two servings given morning and afternoon) in a fortified dairy complementary food (i.e. yogurt containing fruits). Fe absorption was determined based on erythrocyte incorporation of isotopic labels 14 days after consumption of the last test meal. RESULTS: Geometric mean (95% CI) fractional iron absorption from Fe picolinate and Fe sulfate were not significantly different: 5.2% (3.8-7.2%) and 5.3% (3.8-7.3%) (N.S.), respectively. Relative bioavailability of Fe picolinate versus Fe sulfate was 0.99 (0.85-1.15). CONCLUSION: Therefore, Fe picolinate is a promising compound for the fortification of difficult-to-fortify foods, to help meet Fe requirements of infants, young children and women of childbearing age.
Assuntos
Compostos Ferrosos/farmacocinética , Alimentos Fortificados , Ferro/farmacocinética , Ácidos Picolínicos/farmacocinética , Iogurte , Adolescente , Adulto , Disponibilidade Biológica , Estudos Cross-Over , Método Duplo-Cego , Feminino , Frutas/metabolismo , Humanos , Isótopos de Ferro/farmacocinética , Suíça , Adulto JovemRESUMO
OBJECTIVES: The goals of this study were to compare the efficacy of the new manganese-based magnetic resonance imaging (MRI) contrast agent Mn-PyC3A to the commercial gadolinium-based agents Gd-DOTA and to Gd-EOB-DTPA to detect tumors in murine models of breast cancer and metastatic liver disease, respectively, and to quantify the fractional excretion and elimination of Mn-PyC3A in rats. METHODS: T1-weighted contrast-enhanced MRI with 0.1 mmol/kg Mn-PyC3A was compared with 0.1 mmol/kg Gd-DOTA in a breast cancer mouse model (n = 8) and to 0.025 mmol/kg Gd-EOB-DTPA in a liver metastasis mouse model (n = 6). The fractional excretion, 1-day biodistribution, and 7-day biodistribution in rats after injection of 2.0 mmol/kg [Mn]Mn-PyC3A or Gd-DOTA were quantified by Mn gamma counting or Gd elemental analysis. Imaging data were compared with a paired t test; biodistribution data were compared with an unpaired t test. RESULTS: The postinjection-preinjection increases in tumor-to-muscle contrast-to-noise ratio (ΔCNR) 3 minutes after injection of Mn-PyC3A and Gd-DOTA (mean ± standard deviation) were 17 ± 3.8 and 20 ± 4.4, respectively (P = 0.34). Liver-to-tumor ΔCNR values at 8 minutes postinjection of Mn-PyC3A and Gd-EOB-DTPA were 28 ± 9.0 and 48 ± 23, respectively (P = 0.11). Mn-PyC3A is eliminated with 85% into the urine and 15% into the feces after administration to rats. The percentage of the injected doses (%ID) of Mn and Gd recovered in tissues after 1 day were 0.32 ± 0.12 and 0.57 ± 0.12, respectively (P = 0.0030), and after 7 days were 0.058 ± 0.051 and 0.19 ± 0.052, respectively (P < 0.0001). CONCLUSIONS: Mn-PyC3A provides comparable tumor contrast enhancement to Gd-DOTA in a mouse breast cancer model and is more completely eliminated than Gd-DOTA; partial hepatobiliary elimination of Mn-PyC3A enables conspicuous delayed phase visualization of liver metastases.
Assuntos
Neoplasias da Mama/diagnóstico por imagem , Meios de Contraste/farmacocinética , Diaminas/farmacocinética , Aumento da Imagem/métodos , Neoplasias Hepáticas/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Compostos de Manganês/farmacocinética , Manganês/farmacocinética , Ácidos Picolínicos/farmacocinética , Animais , Modelos Animais de Doenças , Feminino , Gadolínio/administração & dosagem , Gadolínio DTPA/farmacocinética , Compostos Heterocíclicos/farmacocinética , Camundongos , Camundongos Endogâmicos BALB C , Compostos Organometálicos/farmacocinética , Distribuição TecidualRESUMO
Metabotropic glutamate receptor 2 (mGluR2) has been suggested as a therapeutic target for treating schizophrenia-like symptoms arising from increased glutamate transmission in the human forebrain. However, no reliable positron emission tomography (PET) radiotracer allowing for in vivo visualization of mGluR2 in the human brain is currently available. In this study, we synthesized 4-(2-fluoro-4-[11C]methoxyphenyl)-5-((2-methylpyridin-4-yl)methoxy)picolinamide ([11C]1) and evaluated its potential as a PET tracer for imaging mGluR2 in the rodent brain. Compound 1, a negative allosteric modulator (NAM) of mGluR2, showed high in vitro binding affinity (IC50: 26â¯nM) for mGluR2 overexpressed in human cells. [11C]1 was synthesized by O-[11C]methylation of the phenol precursor 2 with [11C]methyl iodide. After the reaction, HPLC purification and formulation, [11C]1 of 7.4⯱â¯2.8â¯GBq (nâ¯=â¯8) was obtained from [11C]carbon dioxide of 22.5⯱â¯4.8â¯GBq (nâ¯=â¯8) with >99% radiochemical purity and 70⯱â¯32â¯GBq/µmol (nâ¯=â¯8) molar activity at the end of synthesis. In vitro autoradiography for rat brains showed that [11C]1 binding was heterogeneously distributed in the cerebral cortex, striatum, hippocampus, and cerebellum. This pattern is consistent with the regional distribution pattern of mGluR2 in the rodent brain. The radioactivity was significantly reduced by self- or MNI-137 (a mGluR2 NAM) blocking. Small-animal PET studies indicated a low in vivo specific binding of [11C]1 in the rat brain. The brain uptake was increased in a P-glycoprotein and breast cancer resistant protein double knockout mouse, when compared to a wild-type mouse. While [11C]1 presented limited potential as an in vivo PET tracer for mGluR2, we suggested that it can be used as a lead compound for developing new radiotracers with improved in vivo brain properties.
Assuntos
Encéfalo/diagnóstico por imagem , Ácidos Picolínicos/química , Tomografia por Emissão de Pósitrons , Receptores de Glutamato Metabotrópico/análise , Animais , Encéfalo/metabolismo , Radioisótopos de Carbono , Relação Dose-Resposta a Droga , Humanos , Masculino , Camundongos , Camundongos Endogâmicos , Camundongos Knockout , Estrutura Molecular , Ácidos Picolínicos/síntese química , Ácidos Picolínicos/farmacocinética , Traçadores Radioativos , Ratos , Ratos Sprague-Dawley , Relação Estrutura-Atividade , Distribuição TecidualRESUMO
N-(2-(diethylamino)-ethyl)-18F-5-fluoropicolinamide (18F-P3BZA) is a radiotracer that demonstrates high binding selectivity and affinity in melanoma. The aim of the present study was to estimate the biodistribution and clinical radiation dosimetry of 18F-P3BZA in healthy volunteers and perform a preliminary clinical application for PET/CT imaging in melanoma patients. Methods:18F-P3BZA was produced efficiently with a radiosynthesizer. Six healthy volunteers were injected with 18F-P3BZA (211.7 ± 15.4 MBq) followed by serial whole-body PET/CT scans and blood tests to assess biodistribution, pharmacokinetic, and radiation dosimetry at 10 min, 1 h, 2 h, and 4 h after injection. The vital signs of volunteers were recorded in regular intervals during the imaging sessions. The effective dose for each subject after the medical internal radiation dosimetry schema was calculated with OLINDA/EXM software. For the preliminary clinical application, 5 patients with suspected melanomas underwent 18F-P3BZA PET/CT imaging at 10 min and 1 h after injection. All patients also underwent 18F-FDG PET/CT scans on the third day to compare the potential diagnostic ability of 18F-P3BZA with 18F-FDG. Results: The radiochemistry yield of 18F-P3BZA labeling was 12.3% ± 3.9%, and the purity of 18F-P3BZA after purification and formulation was higher than 99.5%. The highest uptake of 18F-P3BZA was in the liver with an SUVmean of 8.3 ± 1.0 at 10 min after injection. The resultant whole-body effective dose was 0.0193 mSv/MBq. 18F-P3BZA showed high uptake and suggested an ability for specific imaging of melanoma and its metastasis in patients. The average SUVmean of 18F-P3BZA and 18F-FDG in tumors was 19.7 ± 5.3 and 10.8 ± 2.7 at 60 min after injection. Conclusion: Our study suggests that 18F-P3BZA is safe and compatible for clinical use. The first-in-human clinical application to melanoma showed favorable delineated tumors in patients, demonstrating the potential of 18F-P3BZA for diagnostic PET imaging of melanoma.
Assuntos
Melaninas/metabolismo , Ácidos Picolínicos/farmacocinética , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Adulto , Feminino , Voluntários Saudáveis , Humanos , Masculino , Melanoma/diagnóstico por imagem , Melanoma/metabolismo , Pessoa de Meia-Idade , Ácidos Picolínicos/efeitos adversos , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/efeitos adversos , Radiometria , Segurança , Distribuição Tecidual , Imagem Corporal TotalRESUMO
OBJECTIVES: In our preliminary study, chromium malate could decrease the blood glucose level in mice with diabetes and exhibits good benefits in treating glycometabolism and adipose metabolization obstacle in rats with type 2 diabetes. This study was aimed at assessing the pharmacokinetics and bioavailability of chromium malate and influence on trace metals absorption in rats. METHODS: BAPP 2.3 pharmacokinetic calculating program (China Pharmaceutical University Medicine Center) was used to calculate the pharmacokinetic parameters. Models of type 2 diabetic mellitus rats were applied to analyzed Ca, Mg, Fe, Cu, and Zn contents. RESULTS: The results showed that mean retention time (MRT) in chromium malate group was significantly prolonged and the area under the curve (AUC) and relative bioavailability of chromium malate (male) group were significant increase compared to chromium picolinate group. The serum Ca, Mg, Fe, Cu, and Zn contents in chromium malate (at doses of 15 and 20 µg Cr/kg bw) groups were significantly increased compared to control group, chromium trichloride group, and chromium picolinate group in type 2 diabetes mellitus rats. CONCLUSIONS: Those results indicated that chromium malate can significantly prolong MRT and increase AUC (male). Moreover, chromium malate is more effective at treating increased serum Ca, Mg, Fe, Cu, and Zn contents compared to chromium trichloride and chromium picolinate.
Assuntos
Cloretos/farmacocinética , Compostos de Cromo/farmacocinética , Malatos/farmacocinética , Metais/sangue , Ácidos Picolínicos/farmacocinética , Administração Intravenosa , Administração Oral , Animais , Disponibilidade Biológica , Cloretos/administração & dosagem , Compostos de Cromo/administração & dosagem , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Tipo 2/sangue , Fezes/química , Feminino , Malatos/administração & dosagem , Masculino , Ácidos Picolínicos/administração & dosagem , Ratos , Ratos Sprague-Dawley , Distribuição TecidualRESUMO
Multiple sclerosis (MS) is a chronic inflammatory disease affecting the central nervous system (CNS). While multiple effective immunomodulatory therapies for MS exist today, they lack the scope of promoting CNS repair, in particular remyelination. Microglia play a pivotal role in regulating myelination processes, and the colony-stimulating factor 1 (CSF-1) pathway is a key regulator for microglia differentiation and survival. Here, we investigated the effects of the CSF-1 receptor kinase inhibitor, BLZ945, on central myelination processes in the 5-week murine cuprizone model by non-invasive and longitudinal magnetic resonance imaging (MRI) and histology. Therapeutic 2-week BLZ945 treatment caused a brain region-specific enhancement of remyelination in the striatum/cortex, which was absent in the corpus callosum/external capsule. This beneficial effect correlated positively with microglia reduction, increased oligodendrocytes and astrogliosis. Prophylactic BLZ945 treatment prevented excessive demyelination in the corpus callosum by reducing microglia and increasing oligondendrocytes. In the external capsule oligodendrocytes were depleted but not microglia and a buildup of myelin debris and axonal damage was observed. A similar microglial dysfunction in the external capsule with an increase of myelin debris was obvious in triggering receptor expressed on myeloid cells 2 (TREM2) knock-out mice treated with cuprizone. Finally, therapeutic BLZ945 treatment did not change the disease course in experimental autoimmune encephalomyelitis mice, a peripherally driven neuroinflammation model. Taken together, our data suggest that a short-term therapeutic inhibition of the CSF-1 receptor pathway by BLZ945 in the murine cuprizone model enhances central remyelination by modulating neuroinflammation. Thus, microglia-modulating therapies could be considered clinically for promoting myelination in combination with standard-of-care treatments in MS patients.
Assuntos
Benzotiazóis/farmacologia , Encéfalo/efeitos dos fármacos , Doenças Desmielinizantes/tratamento farmacológico , Fármacos Neuroprotetores/farmacologia , Ácidos Picolínicos/farmacologia , Remielinização/efeitos dos fármacos , Animais , Axônios/efeitos dos fármacos , Axônios/patologia , Benzotiazóis/farmacocinética , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Cuprizona , Doenças Desmielinizantes/diagnóstico por imagem , Doenças Desmielinizantes/patologia , Modelos Animais de Doenças , Feminino , Estudos Longitudinais , Imageamento por Ressonância Magnética , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microglia/efeitos dos fármacos , Microglia/patologia , Fármacos Neuroprotetores/farmacocinética , Ácidos Picolínicos/farmacocinética , Receptores de Fator Estimulador das Colônias de Granulócitos e Macrófagos/antagonistas & inibidores , Receptores Imunológicos/genética , Receptores Imunológicos/metabolismo , Medula Espinal/efeitos dos fármacos , Medula Espinal/patologiaRESUMO
Aldehyde oxidase (AO) and xanthine oxidase (XO) are molybdo-flavoenzymes that catalyze oxidation of aromatic azaheterocycles. Differences in AO activity have been reported among various species, including rats, humans, and monkeys. Herein we report a species difference in the enzymes responsible for the metabolism of the negative allosteric modulator of metabotropic glutamate receptor subtype 5 (mGlu5 NAM) VU0424238 (VU238, auglurant). Hepatic S9 incubations with AO and XO specific inhibitors hydralazine and allopurinol indicated that rats and cynomolgus monkeys both oxidized VU238 to the 6-oxopyrimidine metabolite M1 via an AO-mediated pathway, whereas secondary oxidation to the 2,6-dioxopyrimidine metabolite M2 was mediated predominantly by AO in monkeys and XO in rats. Despite differences in enzymatic pathways, intrinsic clearance (CLint) of M1 was similar between species (cynomolgus and rat CLint = 2.00 ± 0.040 and 2.19 ± 0.201 µl/min per milligram of protein, respectively). Inhibitor studies in the S9 of multiple species indicated that oxidation of VU238 to M1 was mediated predominantly by AO in humans, cynomolgus and rhesus monkeys, rats, mice, guinea pigs, and minipigs. Oxidation of M1 to M2 was mediated predominantly by XO in rats and mice and by AO in monkeys and guinea pigs, whereas low turnover prevented enzyme phenotyping in humans and minipigs. Additionally, inhibitor experiments indicated that oxidation at the 2-position of the pyrimidine ring of the known AO substrate, BIBX1382, was mediated by AO in all species, although production of this metabolite was comparatively low in rats and mice. These data may suggest low reactivity of rat AO toward 2-oxidation of pyrimidine-containing compounds and highlight the importance of thoroughly characterizing AO-metabolized drug candidates in multiple preclinical species.
Assuntos
Aldeído Oxidase/metabolismo , Aminopiridinas/metabolismo , Ácidos Picolínicos/metabolismo , Receptor de Glutamato Metabotrópico 5/efeitos dos fármacos , Xantina Oxidase/metabolismo , Aldeído Oxidase/antagonistas & inibidores , Aminopiridinas/farmacocinética , Animais , Inibidores Enzimáticos/farmacologia , Cobaias , Fígado/enzimologia , Macaca fascicularis , Macaca mulatta , Camundongos , Oxirredução , Ácidos Picolínicos/farmacocinética , Ratos , Especificidade da Espécie , Frações Subcelulares/enzimologia , Suínos , Porco Miniatura , Xantina Oxidase/antagonistas & inibidoresRESUMO
BACKGROUND: Phosphatidylserine (PS)-targeting positron emission tomography (PET) imaging with labeled small-molecule tracer is a crucial non-invasive molecule imaging method of apoptosis. In this study, semi-automatic radiosynthesis and biodistribution of N-(2-18F-fluoropropionyl)-bis(zinc(II)-dipicolylamine) (18F-FP-DPAZn2), as a potential small-molecule tracer for PET imaging of cell death in Alzheimer's disease (AD) model, were performed. METHODS: 18F-FP-DPAZn2 was synthesized on the modified PET-MF-2V-IT-I synthesizer. Biodistribution was determined in normal mice and PET images of AD model were obtained on a micro PET-CT scanner. RESULTS: With the modified synthesizer, the total decay-corrected radiochemical yield of 18F-FP-DPAZn2 was 35 ± 6% (n = 5) from 18F- within 105 ± 10 min. Biodistribution results showed that kidney has the highest uptake of 18F-FP-DPAZn2. The uptake of radioactivity in brain kept at a relatively low level during the whole observed time. In vivo 18F-FP-DPAZn2 PET images demonstrated more accumulation of radioactivity in the brain of AD model mice than that in the brain of normal mice. CONCLUSIONS: The semi-automatic synthetic method provides a slightly higher radiochemical yield and shorter whole synthesis time of 18F-FP-DPAZn2 than the manual operation method. This improved method can give enough radioactivity and high radiochemical purity of 18F-FP-DPAZn2 for in vivo PET imaging. The results show that 18F-FP-DPAZn2 seems to be a potential cell death tracer for AD imaging.
Assuntos
Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/metabolismo , Encéfalo/metabolismo , Radioisótopos de Flúor/farmacocinética , Marcação por Isótopo/métodos , Compostos Organometálicos/síntese química , Compostos Organometálicos/farmacocinética , Ácidos Picolínicos/síntese química , Ácidos Picolínicos/farmacocinética , Animais , Encéfalo/diagnóstico por imagem , Composição de Medicamentos/métodos , Radioisótopos de Flúor/química , Taxa de Depuração Metabólica , Camundongos , Imagem Molecular/métodos , Especificidade de Órgãos , Compostos Radiofarmacêuticos/síntese química , Compostos Radiofarmacêuticos/farmacocinética , Robótica/métodos , Distribuição TecidualRESUMO
INTRODUCTION: 18F-5-fluoro-N-(2-(Diethylamino)ethyl)picolinamide (18F-5-FPN) is a new positron-emission tomography (PET) radiopharmaceutical with potential for the detection of lymph node (LN) and pulmonary metastatic lesions of melanoma. We compared its performance with that of 18F-deoxyglucose (18F-FDG). METHODS: Cervical LN and lung melanoma metastasis models were established in C57BL/6 mice. Primary tumors were created by injection of melanoma cells into the pinna, and the resulting cervical LN metastases were evaluated. Lung metastases were created by intravenous injection of melanoma cells. The mice underwent 18F-FDG and 18F-5-FPN positron emission tomography (PET) imaging. A biodistribution study was conducted after imaging. Histopathologic evaluation of the tumors was also performed. RESULTS: LN metastases with a diameter<1cm were more visible on 18F-5-FPN PET imaging than 18F-FDG imaging. Quantitative analysis showed that the uptake of 18F-5-FPN was significantly higher than that of 18F-FDG, with values of 13.29±3.80% ID/g and 7.24±1.95% ID/g (n=5, P<0.05), respectively. LN-to-muscle ratios were 21.23±6.02 and 4.50±2.11 (n=5, P<0.01) for 18F-5-FPN and 18F-FDG, respectively. Biodistribution results were similar, with high uptake of 18F-5-FPN in the LN. 18F-5-FPN imaging manifested the pulmonary lesions clearly, while the 18F-FDG imaging showed no uptake in lesions <2mm. The related uptakes of 18F-5-FPN and 18F-FDG were 3.12±1.17% ID/g and 1.48±0.15% ID/g, respectively (n=5, P<0.05), with lung metastasis-to-muscle ratios of 8.16±3.12 and 1.28±0.18 (n=5, P<0.01), respectively. H&E and Prussian blue staining displayed pluri nucleated or mega nucleus cells and dark brown granules in the metastatic tissues, characteristic of melanoma. CONCLUSIONS: 18F-5-FPN targeted small metastatic lesions with a higher target-to-normal ratio of uptake than those of 18F-FDG, which suggests its ability to detect metastatic lesions earlier than 18F-FDG. Further studies with a wide range of melanoma cell lines should be needed to confirm the similar performance.
Assuntos
Fluordesoxiglucose F18 , Melanoma/diagnóstico por imagem , Melanoma/patologia , Ácidos Picolínicos , Tomografia por Emissão de Pósitrons/métodos , Animais , Linhagem Celular Tumoral , Fluordesoxiglucose F18/farmacocinética , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/secundário , Metástase Linfática , Masculino , Melanoma/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Estadiamento de Neoplasias , Ácidos Picolínicos/farmacocinética , Distribuição TecidualRESUMO
Herein we report the synthesis and characterization of a novel series of N-phenylsulfonyl-1H-pyrrole picolinamides as novel positive allosteric modulators of mGlu4. We detail our work towards finding phenyl replacements for the core scaffold of previously reported phenyl sulfonamides and phenyl sulfone compounds. Our efforts culminated in the identification of N-(1-((3,4-dimethylphenyl)sulfonyl)-1H-pyrrol-3-yl)picolinamide as a potent PAM of mGlu4.
Assuntos
Ácidos Picolínicos/farmacologia , Pirróis/farmacologia , Receptores de Glutamato Metabotrópico/metabolismo , Sulfonamidas/farmacologia , Regulação Alostérica , Animais , Microssomos Hepáticos/metabolismo , Ácidos Picolínicos/síntese química , Ácidos Picolínicos/farmacocinética , Pirróis/síntese química , Pirróis/farmacocinética , Ratos , Relação Estrutura-Atividade , Sulfonamidas/síntese química , Sulfonamidas/farmacocinética , Triazóis/farmacologiaRESUMO
PURPOSE: Radiolabelled benzamides are attractive candidates for targeting melanoma because they bind to melanin and exhibit high tumour uptake and retention. (18)F-5-Fluoro-N-(2-[diethylamino]ethyl)picolinamide ((18)F-5-FPN), a benzamide analogue, was prepared and its pharmacokinetics and binding affinity evaluated both in vitro and in vivo to assess its clinical potential in the diagnosis and staging of melanoma. METHODS: (18)F-5-FPN was prepared and purified. Its binding specificity was measured in vitro in two different melanoma cell lines, one pigmented (B16F10 cells) and one nonpigmented (A375m cells), and in vivo in mice xenografted with the same cell lines. Dynamic and static PET images using (18)F-5-FPN were obtained in the tumour-bearing mice, and the static images were also compared with those acquired with (18)F-FDG. PET imaging with (18)F-5-FPN was also performed in B16F10 tumour-bearing mice with lung metastases. RESULTS: (18)F-5-FPN was successfully prepared with radiochemical yields of 5 - 10 %. Binding of (18)F-5-FPN to B16F10 cells was much higher than to A375m cells. On dynamic PET imaging B16F10 tumours were visible about 1 min after injection of the tracer, and the uptake gradually increased over time. (18)F-5-FPN was rapidly excreted via the kidneys. B16F10 tumours were clearly visible on static images acquired 1 and 2 h after injection, with high uptake values of 24.34 ± 6.32 %ID/g and 16.63 ± 5.41 %ID/g, respectively, in the biodistribution study (five mice). However, there was no visible uptake by A375m tumours. (18)F-5-FPN and (18)F-FDG PET imaging were compared in B16F10 tumour xenografts, and the tumour-to-background ratio of (18)F-5-FPN was ten times higher than that of (18)F-FDG (35.22 ± 7.02 vs. 3.29 ± 0.53, five mice). (18)F-5-FPN PET imaging also detected simulated lung metastases measuring 1 - 2 mm. CONCLUSION: (18)F-5-FPN specifically targeted melanin in vitro and in vivo with high retention and affinity and favourable pharmacokinetics. (18)F-5-FPN may be an ideal molecular probe for melanoma diagnosis and staging.
Assuntos
Melanoma/diagnóstico por imagem , Ácidos Picolínicos , Tomografia por Emissão de Pósitrons/métodos , Amidas/farmacocinética , Animais , Linhagem Celular Tumoral , Feminino , Melanoma/patologia , Camundongos , Estadiamento de Neoplasias , Ácidos Picolínicos/farmacocinéticaRESUMO
Negative allosteric modulators (NAMs) of metabotropic glutamate receptor subtype 5 (mGlu5) have potential applications in the treatment of fragile X syndrome, levodopa-induced dyskinesia in Parkinson disease, Alzheimer disease, addiction, and anxiety; however, clinical and preclinical studies raise concerns that complete blockade of mGlu5 and inverse agonist activity of current mGlu5 NAMs contribute to adverse effects that limit the therapeutic use of these compounds. We report the discovery and characterization of a novel mGlu5 NAM, N,N-diethyl-5-((3-fluorophenyl)ethynyl)picolinamide (VU0477573) that binds to the same allosteric site as the prototypical mGlu5 NAM MPEP but displays weak negative cooperativity. Because of this weak cooperativity, VU0477573 acts as a "partial NAM" so that full occupancy of the MPEP site does not completely inhibit maximal effects of mGlu5 agonists on intracellular calcium mobilization, inositol phosphate (IP) accumulation, or inhibition of synaptic transmission at the hippocampal Schaffer collateral-CA1 synapse. Unlike previous mGlu5 NAMs, VU0477573 displays no inverse agonist activity assessed using measures of effects on basal [(3)H]inositol phosphate (IP) accumulation. VU0477573 acts as a full NAM when measuring effects on mGlu5-mediated extracellular signal-related kinases 1/2 phosphorylation, which may indicate functional bias. VU0477573 exhibits an excellent pharmacokinetic profile and good brain penetration in rodents and provides dose-dependent full mGlu5 occupancy in the central nervous system (CNS) with systemic administration. Interestingly, VU0477573 shows robust efficacy, comparable to the mGlu5 NAM MTEP, in models of anxiolytic activity at doses that provide full CNS occupancy of mGlu5 and demonstrate an excellent CNS occupancy-efficacy relationship. VU0477573 provides an exciting new tool to investigate the efficacy of partial NAMs in animal models.
Assuntos
Agonistas GABAérgicos/farmacologia , Ácidos Picolínicos/farmacologia , Receptor de Glutamato Metabotrópico 5/efeitos dos fármacos , Regulação Alostérica/efeitos dos fármacos , Animais , Ansiolíticos/farmacologia , Astrócitos/efeitos dos fármacos , Astrócitos/metabolismo , Comportamento Animal/efeitos dos fármacos , Encéfalo/metabolismo , Relação Dose-Resposta a Droga , Descoberta de Drogas , Agonistas GABAérgicos/farmacocinética , Células HEK293 , Humanos , Fosfatos de Inositol/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Potenciais da Membrana/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Ácidos Picolínicos/farmacocinética , Piridinas/metabolismo , Ensaio Radioligante , Ratos , Receptor de Glutamato Metabotrópico 5/metabolismo , Transmissão Sináptica/efeitos dos fármacosRESUMO
BACKGROUND: Alzheimer's disease (AD) is the most common form of dementia, the number of affected individuals is rising, with significant impacts for healthcare systems. Current symptomatic treatments delay, but do not halt, disease progression. Genetic evidence points to aggregation and deposition of amyloid-ß (Aß) in the brain being causal for the neurodegeneration and dementia typical of AD. Approaches to target Aß via inhibition of γ-secretase or passive antibody therapy have not yet resulted in substantial clinical benefits. Inhibition of BACE1 (ß-secretase) has proven a challenging concept, but recent BACE1inhibitors can enter the brain sufficiently well to lower Aß. However, failures with the first clinical BACE1 inhibitors have highlighted the need to generate compounds with appropriate efficacy and safety profiles, since long treatment periods are expected to be necessary in humans. RESULTS: Treatment with NB-360, a potent and brain penetrable BACE-1 inhibitor can completely block the progression of Aß deposition in the brains of APP transgenic mice, a model for amyloid pathology. We furthermore show that almost complete reduction of Aß was achieved also in rats and in dogs, suggesting that these findings are translational across species and can be extrapolated to humans. Amyloid pathology may be an initial step in a complex pathological cascade; therefore we investigated the effect of BACE-1 inhibition on neuroinflammation, a prominent downstream feature of the disease. NB-360 stopped accumulation of activated inflammatory cells in the brains of APP transgenic mice. Upon chronic treatment of APP transgenic mice, patches of grey hairs appeared. CONCLUSIONS: In a rapidly developing field, the data on NB-360 broaden the chemical space and expand knowledge on the properties that are needed to make a BACE-1 inhibitor potent and safe enough for long-term use in patients. Due to its excellent brain penetration, reasonable oral doses of NB-360 were sufficient to completely block amyloid-ß deposition in an APP transgenic mouse model. Data across species suggest similar treatment effects can possibly be achieved in humans. The reduced neuroinflammation upon amyloid reduction by NB-360 treatment supports the notion that targeting amyloid-ß pathology can have beneficial downstream effects on the progression of Alzheimer's disease.
Assuntos
Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Peptídeos beta-Amiloides/metabolismo , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Proteínas do Tecido Nervoso/antagonistas & inibidores , Fármacos Neuroprotetores/uso terapêutico , Ácidos Picolínicos/uso terapêutico , Tiazinas/uso terapêutico , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/genética , Secretases da Proteína Precursora do Amiloide/fisiologia , Peptídeos beta-Amiloides/genética , Animais , Ácido Aspártico Endopeptidases/fisiologia , Astrócitos/efeitos dos fármacos , Astrócitos/patologia , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/patologia , Células CHO , Cricetinae , Cricetulus , Cães , Avaliação Pré-Clínica de Medicamentos , Feminino , Cor de Cabelo/efeitos dos fármacos , Humanos , Camundongos , Camundongos Transgênicos , Microglia/efeitos dos fármacos , Microglia/patologia , Mutação , Proteínas do Tecido Nervoso/fisiologia , Fármacos Neuroprotetores/farmacocinética , Fragmentos de Peptídeos/metabolismo , Ácidos Picolínicos/química , Ácidos Picolínicos/farmacocinética , Ratos , Proteínas Recombinantes de Fusão/metabolismo , Tiazinas/química , Tiazinas/farmacocinéticaRESUMO
As part of our efforts to develop CB2 PET imaging agents, we investigated 2,5,6-substituted pyridines as a novel class of potential CB2 PET ligands. A total of 21 novel compounds were designed, synthesized, and evaluated for their potency and binding properties toward human and rodent CB1 and CB2. The most promising ligand 6a was radiolabeled with carbon-11 to yield 16 ([(11)C]RSR-056). Specific binding of 16 to CB2-positive spleen tissue of rats and mice was demonstrated by in vitro autogadiography and verified in vivo in PET and biodistribution experiments. Furthermore, 16 was evaluated in a lipopolysaccharid (LPS) induced murine model of neuroinflammation. Brain radioactivity was strikingly higher in the LPS-treated mice than the control mice. Compound 16 is a promising radiotracer for imaging CB2 in rodents. It might serve as a tool for the investigation of CB2 receptor expression levels in healthy tissues and different neuroinflammatory disorders in humans.
Assuntos
Meios de Contraste/química , Meios de Contraste/farmacocinética , Tomografia por Emissão de Pósitrons/métodos , Receptor CB2 de Canabinoide/análise , Animais , Azetidinas/química , Azetidinas/farmacocinética , Células CHO , Cricetulus , Descoberta de Drogas , Avaliação Pré-Clínica de Medicamentos/métodos , Estabilidade de Medicamentos , Humanos , Masculino , Camundongos Endogâmicos , Ácidos Picolínicos/química , Ácidos Picolínicos/farmacocinética , Piridinas/química , Ratos Wistar , Receptor CB1 de Canabinoide/análise , Receptor CB1 de Canabinoide/genética , Receptor CB1 de Canabinoide/metabolismo , Receptor CB2 de Canabinoide/genética , Receptor CB2 de Canabinoide/metabolismo , Distribuição TecidualRESUMO
The synthesis and structure-activity relationship of a series of 6-substituted picolinamide inhibitors of 11ß-hydroxysteroid dehydrogenase type 1 are described. The optimization of the left-hand side of lead compound 1 resulted in the discovery of the highly potent, selective, and orally available inhibitor 24, which demonstrated an excellent activity in a mouse ex vivo pharmacodynamic model. Moreover, compound 24 reduced the blood glucose and improved the lipid profiles in ob/ob mice after oral administration.
Assuntos
11-beta-Hidroxiesteroide Desidrogenase Tipo 1/metabolismo , Inibidores Enzimáticos/síntese química , Ácidos Picolínicos/química , 11-beta-Hidroxiesteroide Desidrogenase Tipo 1/antagonistas & inibidores , Administração Oral , Amidas/química , Amidas/farmacocinética , Amidas/uso terapêutico , Animais , Glicemia/análise , Catálise , Diabetes Mellitus Experimental/tratamento farmacológico , Inibidores Enzimáticos/farmacocinética , Inibidores Enzimáticos/uso terapêutico , Células HEK293 , Meia-Vida , Humanos , Lipídeos/sangue , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , Paládio/química , Ácidos Picolínicos/farmacocinética , Ácidos Picolínicos/uso terapêutico , Ligação Proteica , Relação Estrutura-AtividadeRESUMO
BACE1 is a key protease controlling the formation of amyloid ß, a peptide hypothesized to play a significant role in the pathogenesis of Alzheimer's disease (AD). Therefore, the development of potent and selective inhibitors of BACE1 has been a focus of many drug discovery efforts in academia and industry. Herein, we report the nonclinical and early clinical development of LY2886721, a BACE1 active site inhibitor that reached phase 2 clinical trials in AD. LY2886721 has high selectivity against key off-target proteases, which efficiently translates in vitro activity into robust in vivo amyloid ß lowering in nonclinical animal models. Similar potent and persistent amyloid ß lowering was observed in plasma and lumbar CSF when single and multiple doses of LY2886721 were administered to healthy human subjects. Collectively, these data add support for BACE1 inhibition as an effective means of amyloid lowering and as an attractive target for potential disease modification therapy in AD.