RESUMO
The Dp(10)2Yey mouse carries a â¼2.3-Mb intra-chromosomal duplication of mouse chromosome 10 (Mmu10) that has homology to human chromosome 21, making it an essential model for aspects of Down syndrome (DS, trisomy 21). In this study, we investigated neuronal dysfunction in the Dp(10)2Yey mouse and report spatial memory impairment and anxiety-like behavior alongside altered neural activity in the medial prefrontal cortex (mPFC) and hippocampus (HPC). Specifically, Dp(10)2Yey mice showed impaired spatial alternation associated with increased sharp-wave ripple activity in mPFC during a period of memory consolidation, and reduced mobility in a novel environment accompanied by reduced theta-gamma phase-amplitude coupling in HPC. Finally, we found alterations in the number of interneuron subtypes in mPFC and HPC that may contribute to the observed phenotypes and highlight potential approaches to ameliorate the effects of human trisomy 21.
RESUMO
Despite the well-accepted role of the two main neuropathological markers (ß-amyloid and tau) in the progression of Alzheimer's disease, the interaction and specific contribution of each of them is not fully elucidated. To address this question, in the present study, an adeno-associated virus (AAV9) carrying the mutant P301L form of human tau, was injected into the dorsal hippocampi of APP/PS1 transgenic mice or wild type mice (WT). Three months after injections, memory tasks, biochemical and immunohistochemical analysis were performed. We found that the overexpression of hTauP301L accelerates memory deficits in APP/PS1 mice, but it did not affect memory function of WT mice. Likewise, biochemical assays showed that only in the case of APP/PS1-hTauP301L injected mice, an important accumulation of tau was observed in the insoluble urea fraction. Similarly, electron microscopy images revealed that numerous clusters of tau immunoparticles appear at the dendrites of APP/PS1 injected mice and not in WT animals, suggesting that the presence of amyloid is necessary to induce tau aggregation. Interestingly, these tau immunoparticles accumulate in dendritic mitochondria in the APP/PS1 mice, whereas most of mitochondria in WT injected mice remain free of tau immunoparticles. Taken together, it seems that amyloid induces tau aggregation and accumulation in the dendritic mitochondria and subsequently may alter synapse function, thus, contributing to accelerate cognitive decline in APP/PS1 mice.
Assuntos
Doença de Alzheimer/complicações , Peptídeos beta-Amiloides/efeitos adversos , Transtornos Cognitivos/patologia , Modelos Animais de Doenças , Mitocôndrias/patologia , Proteínas tau/metabolismo , Precursor de Proteína beta-Amiloide/fisiologia , Animais , Transtornos Cognitivos/etiologia , Transtornos Cognitivos/metabolismo , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Mitocôndrias/metabolismo , Fosforilação , Presenilina-1/fisiologia , Sinapses , Proteínas tau/genéticaRESUMO
Understanding the mechanisms involved in cognitive resilience in Alzheimer's disease (AD) represents a promising strategy to identify novel treatments for dementia in AD. Previous findings from our group revealed that the study of aged-Tg2576 cognitive resilient individuals is a suitable tool for this purpose. In the present study, we performed a transcriptomic analysis using the prefrontal cortex of demented and resilient Tg2576 transgenic AD mice. We have been able to hypothesize that pathways involved in inflammation, amyloid degradation, memory function, and neurotransmission may be playing a role on cognitive resilience in AD. Intriguingly, the results obtained in this study are suggestive of a reduction of the influx of peripheral immune cells into the brain on cognitive resilient subjects. Indeed, CD4 mRNA expression is significantly reduced on Tg2576 mice with cognitive resilience. For further validation of this result, we analyzed CD4 expression in human AD samples, including temporal cortex and peripheral blood mononuclear cells (PBMC). Interestingly, we have found a negative correlation between CD4 mRNA levels in the periphery and the score in the Mini-Mental State Exam of AD patients. These findings highlight the importance of understanding the role of the immune system on the development of neurodegenerative diseases and points out to the infiltration of CD4+ cells in the brain as a key player of cognitive dysfunction in AD.
Assuntos
Doença de Alzheimer/metabolismo , Antígenos CD4/genética , Córtex Cerebral/metabolismo , Cognição , Inflamação , Leucócitos Mononucleares/metabolismo , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/genética , Doença de Alzheimer/imunologia , Doença de Alzheimer/fisiopatologia , Animais , Córtex Cerebral/fisiologia , Feminino , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Humanos , Masculino , Camundongos , Camundongos Transgênicos , Pessoa de Meia-Idade , Córtex Pré-Frontal/metabolismo , Lobo Temporal/metabolismoRESUMO
Clinical studies revealed that some aged-individuals accumulate a significant number of histopathological Alzheimer´s disease (AD) lesions in their brain, yet without developing any signs of dementia. Animal models of AD represent suitable tools to identify genes that might promote cognitive resilience and hence, this study first set out to identify cognitively resilient individuals in the aged-Tg2576 mouse model. A transcriptomic analysis of these mice identified PLA2G4E as a gene that might confer resistance to dementia. Indeed, a significant decrease in PLA2G4E is evident in the brain of late-stage AD patients, whereas no such changes are observed in early stage patients with AD neuropathological lesions but no signs of dementia. We demonstrated that adeno-associated viral vector-mediated overexpression of PLA2G4E in hippocampal neurons completely restored cognitive deficits in elderly APP/PS1 mice, without affecting the amyloid or tau pathology. These PLA2G4E overexpressing APP/PS1 mice developed significantly more dendritic spines than sham-injected mice, coinciding with the cognitive improvement observed. Hence, these results support the idea that a loss of PLA2G4E might play a key role in the onset of dementia in AD, highlighting the potential of PLA2G4E overexpression as a novel therapeutic strategy to manage AD and other disorders that course with memory deficits.
Assuntos
Doença de Alzheimer/genética , Doença de Alzheimer/terapia , Espinhas Dendríticas , Terapia Genética , Fosfolipases A2 do Grupo IV/fisiologia , Fosfolipases A2 do Grupo IV/uso terapêutico , Hipocampo , Memória Espacial , Animais , Comportamento Animal/fisiologia , Modelos Animais de Doenças , Feminino , Regulação da Expressão Gênica/genética , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos TransgênicosRESUMO
Irreversible electroporation (IRE) is a non-thermic ablation therapy which has been proposed for locally advanced pancreatic adenocarcinoma (LAPC) as well as for the local control of other types of tumors (kidney or liver). Its use has been extended in the last few years worldwide. Its advantage over other ablation techniques is that it only affects the lipids bilayer of the cell membrane avoiding vascular damage. Safety and viability have been demonstrated in recent studies. Overall survival seems (OS) to improve when it is combined with chemotherapy compared to chemotherapy with or without radiotherapy. Clinical trials should confirm these encouraging data.
Assuntos
Adenocarcinoma/cirurgia , Eletroporação/métodos , Neoplasias Pancreáticas/cirurgia , Adenocarcinoma/mortalidade , Adenocarcinoma/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Pancreáticas/mortalidade , Neoplasias Pancreáticas/patologia , Taxa de Sobrevida , Resultado do TratamentoRESUMO
Here, we present a series of dual-target phosphodiesterase 9 (PDE9) and histone deacetylase (HDAC) inhibitors devised as pharmacological tool compounds for assessing the implications of these two targets in Alzheimer's disease (AD). These novel inhibitors were designed taking into account the key pharmacophoric features of known selective PDE9 inhibitors as well as privileged chemical structures, bearing zinc binding groups (hydroxamic acids and ortho-amino anilides) that hit HDAC targets. These substituents were selected according to rational criteria and previous knowledge from our group to explore diverse HDAC selectivity profiles (pan-HDAC, HDAC6 selective, and class I selective) that were confirmed in biochemical screens. Their functional response in inducing acetylation of histone and tubulin and phosphorylation of cAMP response element binding (CREB) was measured as a requisite for further progression into complete in vitro absorption, distribution, metabolism and excretion (ADME) and in vivo brain penetration profiling. Compound 31b, a selective HDAC6 inhibitor with acceptable brain permeability, was chosen for assessing in vivo efficacy of these first-in-class inhibitors, as well as studying their mode of action (MoA).
Assuntos
3',5'-AMP Cíclico Fosfodiesterases/antagonistas & inibidores , Doença de Alzheimer/metabolismo , Inibidores de Histona Desacetilases/farmacologia , Histona Desacetilases/metabolismo , Ácidos Hidroxâmicos/metabolismo , Acetilação , Histona Desacetilases/química , Humanos , Ácidos Hidroxâmicos/química , Estrutura Molecular , Diester Fosfórico Hidrolases/metabolismo , Relação Estrutura-AtividadeRESUMO
The discouraging results with therapies for Alzheimer's disease (AD) in clinical trials, highlights the urgent need to adopt new approaches. Like other complex diseases, it is becoming clear that AD therapies should focus on the simultaneous modulation of several targets implicated in the disease. Recently, using reference compounds and the first-in class CM-414, we demonstrated that the simultaneous inhibition of histone deacetylases [class I histone deacetylases (HDACs) and HDAC6] and phosphodiesterase 5 (PDE5) has a synergistic therapeutic effect in AD models. To identify the best inhibitory balance of HDAC isoforms and PDEs that provides a safe and efficient therapy to combat AD, we tested the compound CM-695 in the Tg2576 mouse model of this disease. CM-695 selectively inhibits HDAC6 over class I HDAC isoforms, which largely overcomes the toxicity associated with HDAC class 1 inhibition. Furthermore, CM-695 inhibits PDE9, which is expressed strongly in the brain and has been proposed as a therapeutic target for AD. Chronic treatment of aged Tg2576 mice with CM-695 ameliorates memory impairment and diminishes brain Aß, although its therapeutic effect was no longer apparent 4 weeks after the treatment was interrupted. An increase in the presence of 78-KDa glucose regulated protein (GRP78) and heat shock protein 70 (Hsp70) chaperones may underlie the therapeutic effect of CM-695. In summary, chronic treatment with CM-695 appears to reverse the AD phenotype in a safe and effective manner. Taking into account that AD is a multifactorial disorder, the multimodal action of these compounds and the different events they affect may open new avenues to combat AD.
RESUMO
In order to determine the contributions of histone deacetylase (HDAC) isoforms to the beneficial effects of dual phosphodiesterase 5 (PDE5) and pan-HDAC inhibitors on in vivo models of Alzheimer's disease (AD), we have designed, synthesized, and tested novel chemical probes with the desired target compound profile of PDE5 and class I HDAC selective inhibitors. Compared to previous hydroxamate-based series, these molecules exhibit longer residence times on HDACs. In this scenario, shorter or longer preincubation times may have a significant impact on the IC50 values of these compounds and therefore on their corresponding selectivity profiles on the different HDAC isoforms. On the other hand, different chemical series have been explored and, as expected, some pairwise comparisons show a clear impact of the scaffold on biological responses (e.g., 35a vs 40a). The lead identification process led to compound 29a, which shows an adequate ADME-Tox profile and in vivo target engagement (histone acetylation and cAMP/cGMP response element-binding (CREB) phosphorylation) in the central nervous system (CNS), suggesting that this compound represents an optimized chemical probe; thus, 29a has been assayed in a mouse model of AD (Tg2576).
Assuntos
Doença de Alzheimer/tratamento farmacológico , Nucleotídeo Cíclico Fosfodiesterase do Tipo 5/metabolismo , Inibidores de Histona Desacetilases/farmacologia , Inibidores da Fosfodiesterase 5/farmacologia , Acetilação/efeitos dos fármacos , Animais , Modelos Animais de Doenças , Inibidores de Histona Desacetilases/química , Histona Desacetilases/efeitos dos fármacos , Histona Desacetilases/metabolismo , Humanos , Camundongos , Inibidores da Fosfodiesterase 5/químicaRESUMO
We have identified chemical probes that act as dual phosphodiesterase 5 (PDE5) and histone deacetylase 6 (HDAC6)-selective inhibitors (>1 log unit difference versus class I HDACs) to decipher the contribution of HDAC isoforms to the positive impact of dual-acting PDE5 and HDAC inhibitors on mouse models of Alzheimer's disease (AD) and fine-tune this systems therapeutics approach. Structure- and knowledge-based approaches led to the design of first-in-class molecules with the desired target compound profile: dual PDE5 and HDAC6-selective inhibitors. Compound 44b, which fulfilled the biochemical, functional and ADME-Tox profiling requirements and exhibited adequate pharmacokinetic properties, was selected as pharmacological tool compound and tested in a mouse model of AD (Tg2576) in vivo.
Assuntos
Doença de Alzheimer/tratamento farmacológico , Nucleotídeo Cíclico Fosfodiesterase do Tipo 5/metabolismo , Desenho de Fármacos , Desacetilase 6 de Histona/antagonistas & inibidores , Inibidores de Histona Desacetilases/farmacologia , Inibidores da Fosfodiesterase 5/farmacologia , Doença de Alzheimer/metabolismo , Linhagem Celular , Relação Dose-Resposta a Droga , Desacetilase 6 de Histona/metabolismo , Inibidores de Histona Desacetilases/síntese química , Inibidores de Histona Desacetilases/química , Humanos , Estrutura Molecular , Neuroglia/efeitos dos fármacos , Inibidores da Fosfodiesterase 5/síntese química , Inibidores da Fosfodiesterase 5/química , Relação Estrutura-AtividadeRESUMO
A complex network of interactions exists between the immune, the olfactory, and the central nervous system (CNS). Inhalation of different fragrances can affect immunological reactions in response to an antigen but also may have effects on the CNS and cognitive activity. We performed an exploratory study of the immunomodulatory ability of a series of compounds representing each of the 10 odor categories or clusters described previously. We evaluated the impact of each particular odor on the immune response after immunization with the model antigen ovalbumin in combination with the TLR3 agonist poly I:C. We found that some odors behave as immunostimulatory agents, whereas others might be considered as potential immunosuppressant odors. Interestingly, the immunomodulatory capacity was, in some cases, strain-specific. In particular, one of the fragrances, carvone, was found to be immunostimulatory in BALB/c mice and immunosuppressive in C57BL/6J mice, facilitating or impairing viral clearance, respectively, in a model of a viral infection with a recombinant adenovirus. Importantly, inhalation of the odor improved the memory capacity in BALB/c mice in a fear-conditioning test, while it impaired this same capacity in C57BL/6J mice. The improvement in memory capacity in BALB/c was associated with higher CD3+ T cell infiltration into the hippocampus and increased local expression of mRNA coding for IL-1ß, TNF-α, and IL-6 cytokines. In contrast, the memory impairment in C57BL/6 was associated with a reduction in CD3 numbers and an increase in IFN-γ. These data suggest an association between the immunomodulatory capacity of smells and their impact on the cognitive functions of the animals. These results highlight the potential of studying odors as therapeutic agents for CNS-related diseases.
Assuntos
Medo/psicologia , Fatores Imunológicos/farmacologia , Imunomodulação/efeitos dos fármacos , Memória/efeitos dos fármacos , Monoterpenos/farmacologia , Administração por Inalação , Animais , Cognição , Condicionamento Psicológico , Monoterpenos Cicloexânicos , Modelos Animais de Doenças , Suscetibilidade a Doenças , Feminino , Perfilação da Expressão Gênica , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Hipocampo/patologia , Fatores Imunológicos/administração & dosagem , Imunomodulação/genética , Leucócitos/efeitos dos fármacos , Leucócitos/patologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Monoterpenos/administração & dosagem , Odorantes , Viroses/etiologiaRESUMO
A novel systems therapeutics approach, involving simultaneous inhibition of phosphodiesterase 5 (PDE5) and histone deacetylase (HDAC), has been validated as a potentially novel therapeutic strategy for the treatment of Alzheimer's disease (AD). First-in-class dual inhibitors bearing a sildenafil core have been very recently reported, and the lead molecule 7 has proven this strategy in AD animal models. Because scaffolds may play a critical role in primary activities and ADME-Tox profiling as well as on intellectual property, we have explored alternative scaffolds (vardenafil- and tadalafil-based cores) and evaluated their impact on critical parameters such as primary activities, permeability, toxicity, and in vivo (pharmacokinetics and functional response in hippocampus) to identify a potential alternative lead molecule bearing a different chemotype for in vivo testing.
Assuntos
Doença de Alzheimer/tratamento farmacológico , Inibidores de Histona Desacetilases/uso terapêutico , Inibidores da Fosfodiesterase 5/uso terapêutico , 3',5'-AMP Cíclico Fosfodiesterases/metabolismo , Trifosfato de Adenosina/metabolismo , Doença de Alzheimer/patologia , Animais , Linhagem Celular Transformada , GMP Cíclico/metabolismo , Nucleotídeo Cíclico Fosfodiesterase do Tipo 5/metabolismo , Inibidores de Histona Desacetilases/química , Inibidores de Histona Desacetilases/farmacologia , Humanos , Leucócitos Mononucleares , Camundongos , Microssomos Hepáticos/efeitos dos fármacos , Modelos Moleculares , Neuroglia/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Inibidores da Fosfodiesterase 5/química , Inibidores da Fosfodiesterase 5/farmacologiaRESUMO
The targeting of two independent but synergistic enzymatic activities, histone deacetylases (HDACs, class I and HDAC6) and phosphodiesterase 5 (PDE5), has recently been validated as a potentially novel therapeutic approach for Alzheimer's disease (AD). Here we report the discovery of a new first-in-class small-molecule (CM-414) that acts as a dual inhibitor of PDE5 and HDACs. We have used this compound as a chemical probe to validate this systems therapeutics strategy, where an increase in the activation of cAMP/cGMP-responsive element-binding protein (CREB) induced by PDE5 inhibition, combined with moderate HDAC class I inhibition, leads to efficient histone acetylation. This molecule rescued the impaired long-term potentiation evident in hippocampal slices from APP/PS1 mice. Chronic treatment of Tg2576 mice with CM-414 diminished brain Aß and tau phosphorylation (pTau) levels, increased the inactive form of GSK3ß, reverted the decrease in dendritic spine density on hippocampal neurons, and reversed their cognitive deficits, at least in part by inducing the expression of genes related to synaptic transmission. Thus, CM-414 may serve as the starting point to discover balanced dual inhibitors with an optimal efficacy and safety profile for clinical testing on AD patients.
Assuntos
Doença de Alzheimer/tratamento farmacológico , Hipocampo/efeitos dos fármacos , Inibidores de Histona Desacetilases/administração & dosagem , Plasticidade Neuronal/efeitos dos fármacos , Inibidores da Fosfodiesterase 5/administração & dosagem , Pirazóis/uso terapêutico , Pirimidinonas/uso terapêutico , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Doença de Alzheimer/prevenção & controle , Animais , Comportamento Animal/efeitos dos fármacos , Modelos Animais de Doenças , Feminino , Hipocampo/fisiopatologia , Inibidores de Histona Desacetilases/farmacologia , Camundongos , Camundongos Transgênicos , Atividade Motora/efeitos dos fármacos , Inibidores da Fosfodiesterase 5/farmacologia , Cultura Primária de Células , Pirazóis/administração & dosagem , Pirazóis/farmacologia , Pirimidinonas/administração & dosagem , Pirimidinonas/farmacologiaRESUMO
Simultaneous inhibition of phosphodiesterase 5 (PDE5) and histone deacetylases (HDAC) has recently been validated as a potentially novel therapeutic approach for Alzheimer's disease (AD). To further extend this concept, we designed and synthesized the first chemical series of dual acting PDE5 and HDAC inhibitors, and we validated this systems therapeutics approach. Following the implementation of structure- and knowledge-based approaches, initial hits were designed and were shown to validate our hypothesis of dual in vitro inhibition. Then, an optimization strategy was pursued to obtain a proper tool compound for in vivo testing in AD models. Initial hits were translated into molecules with adequate cellular functional responses (histone acetylation and cAMP/cGMP response element-binding (CREB) phosphorylation in the nanomolar range), an acceptable therapeutic window (>1 log unit), and the ability to cross the blood-brain barrier, leading to the identification of 7 as a candidate for in vivo proof-of-concept testing ( Cuadrado-Tejedor, M.; Garcia-Barroso, C.; Sánchez-Arias, J. A.; Rabal, O.; Mederos, S.; Ugarte, A.; Franco, R.; Segura, V.; Perea, G.; Oyarzabal, J.; Garcia-Osta, A. Neuropsychopharmacology 2016 , in press, doi: 10.1038/npp.2016.163 ).