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1.
J Cell Mol Med ; 28(11): e18477, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38853458

RESUMO

Given the pathological role of Tau aggregation in Alzheimer's disease (AD), our laboratory previously developed the novel Tau aggregation inhibitor peptide, RI-AG03. As Tau aggregates accumulate intracellularly, it is essential that the peptide can traverse the cell membrane. Here we examine the cellular uptake and intracellular trafficking of RI-AG03, in both a free and liposome-conjugated form. We also characterize the impact of adding the cell-penetrating peptide (CPP) sequences, polyarginine (polyR) or transactivator of transcription (TAT), to RI-AG03. Our data show that liposome conjugation of CPP containing RI-AG03 peptides, with either the polyR or TAT sequence, increased cellular liposome association three-fold. Inhibition of macropinocytosis modestly reduced the uptake of unconjugated and RI-AG03-polyR-linked liposomes, while having no effect on RI-AG03-TAT-conjugated liposome uptake. Further supporting macropinocytosis-mediated internalization, a 'fair' co-localisation of the free and liposome-conjugated RI-AG03-polyR peptide with macropinosomes and lysosomes was observed. Interestingly, we also demonstrate that RI-AG03-polyR detaches from liposomes following cellular uptake, thereby largely evading organellar entrapment. Collectively, our data indicate that direct membrane penetration and macropinocytosis are key routes for the internalization of liposomes conjugated with CPP containing RI-AG03. Our study also demonstrates that peptide-liposomes are suitable nanocarriers for the cellular delivery of RI-AG03, furthering their potential use in targeting Tau pathology in AD.


Assuntos
Peptídeos Penetradores de Células , Lipossomos , Nanopartículas , Pinocitose , Proteínas tau , Peptídeos Penetradores de Células/química , Peptídeos Penetradores de Células/farmacologia , Lipossomos/química , Humanos , Proteínas tau/metabolismo , Proteínas tau/química , Nanopartículas/química , Pinocitose/efeitos dos fármacos , Peptídeos/química , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Lisossomos/metabolismo , Sistemas de Liberação de Medicamentos/métodos
2.
Cereb Cortex ; 30(4): 2358-2371, 2020 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-31812984

RESUMO

2p16.3 deletions, involving heterozygous NEUREXIN1 (NRXN1) deletion, dramatically increase the risk of developing neurodevelopmental disorders, including autism and schizophrenia. We have little understanding of how NRXN1 heterozygosity increases the risk of developing these disorders, particularly in terms of the impact on brain and neurotransmitter system function and brain network connectivity. Thus, here we characterize cerebral metabolism and functional brain network connectivity in Nrxn1α heterozygous mice (Nrxn1α+/- mice), and assess the impact of ketamine and dextro-amphetamine on cerebral metabolism in these animals. We show that heterozygous Nrxn1α deletion alters cerebral metabolism in neural systems implicated in autism and schizophrenia including the thalamus, mesolimbic system, and select cortical regions. Nrxn1α heterozygosity also reduces the efficiency of functional brain networks, through lost thalamic "rich club" and prefrontal cortex (PFC) hub connectivity and through reduced thalamic-PFC and thalamic "rich club" regional interconnectivity. Subanesthetic ketamine administration normalizes the thalamic hypermetabolism and partially normalizes thalamic disconnectivity present in Nrxn1α+/- mice, while cerebral metabolic responses to dextro-amphetamine are unaltered. The data provide new insight into the systems-level impact of heterozygous Nrxn1α deletion and how this increases the risk of developing neurodevelopmental disorders. The data also suggest that the thalamic dysfunction induced by heterozygous Nrxn1α deletion may be NMDA receptor-dependent.


Assuntos
Proteínas de Ligação ao Cálcio/genética , Ketamina/administração & dosagem , Moléculas de Adesão de Célula Nervosa/genética , Transtornos do Neurodesenvolvimento/diagnóstico por imagem , Transtornos do Neurodesenvolvimento/genética , Córtex Pré-Frontal/diagnóstico por imagem , Tálamo/diagnóstico por imagem , Animais , Modelos Animais de Doenças , Deleção de Genes , Injeções Intraperitoneais , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Rede Nervosa/diagnóstico por imagem , Rede Nervosa/efeitos dos fármacos , Transtornos do Neurodesenvolvimento/tratamento farmacológico , Córtex Pré-Frontal/efeitos dos fármacos , Tálamo/efeitos dos fármacos
3.
Eur J Neurosci ; 52(2): 2838-2852, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-31989721

RESUMO

Mitogen-activated protein kinases (MAPKs) regulate normal brain functioning, and their dysfunction is implicated in a number of brain disorders. Thus, there is great interest in understanding the signalling systems that control MAPK functioning. One family of proteins that contribute to this process, the mitogen-activated protein kinase phosphatases (MKPs), directly inactivate MAPKs through dephosphorylation. Recent studies have identified novel functions of MKPs in foetal development, the immune system, cancer and synaptic plasticity and memory. In the present study, we performed an unbiased investigation using MKP-2-/- mice to assess whether MKP-2 plays a global role in modulating brain function. Local cerebral glucose utilization is significantly increased in the ventral tegmental area (VTA) of MKP-2-/- mice, with connectivity analysis revealing alterations in VTA functional connectivity, including a significant reduction in connectivity to the nucleus accumbens and hippocampus. In addition, spontaneous excitatory postsynaptic current frequency, but not amplitude, onto putative dopamine neurons in the VTA is increased in MKP-2-/- mice, which indicates that increased excitatory drive may account for the increased VTA glucose utilization. Consistent with modified VTA function and connectivity, in behavioural tests MKP-2-/- mice exhibited increased sucrose preference and impaired amphetamine-induced hyperlocomotion. Overall, these data reveal that MKP-2 plays a role in modulating VTA function and that its dysfunction may contribute to brain disorders in which altered reward processing is present.


Assuntos
Fosfatases da Proteína Quinase Ativada por Mitógeno/genética , Proteínas Tirosina Fosfatases/genética , Área Tegmentar Ventral , Anfetamina , Animais , Deleção de Genes , Camundongos , Camundongos Knockout , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Proteína Fosfatase 1 , Recompensa , Área Tegmentar Ventral/metabolismo
4.
Mol Pharm ; 17(4): 1148-1158, 2020 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-32058728

RESUMO

Punch sticking during tablet manufacturing is a common problem facing the pharmaceutical industry. Using several model compounds, effects of crystal size and shape of active pharmaceutical ingredients (API) on punch sticking propensity were systematically investigated in this work to provide molecular insights into the punch-sticking phenomenon. In contrast to the common belief that smaller API particles aggravate punch sticking, results show that particle size reduction can either reduce or enhance API punch sticking, depending on the complex interplay among the particle surface area, plasticity, cohesive strength, and specific surface functional groups. Therefore, other factors, such as crystal mechanical properties, surface chemistry of crystal facets exposed to the punch face, and choice of excipients in a formulation, should be considered for a more reliable prediction of the initiation and progression of punch sticking. The exposure of strong electronegative groups to the punch face facilitates the onset of sticking, while higher plasticity and cohesive strength aggravate sticking.


Assuntos
Preparações Farmacêuticas/química , Pós/química , Comprimidos/química , Adesividade , Química Farmacêutica/métodos , Excipientes/química , Tamanho da Partícula , Pressão , Propriedades de Superfície
5.
AAPS PharmSciTech ; 21(6): 218, 2020 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-32743765

RESUMO

The attrition of drug particles during the process of dry granulation, which may (or may not) be incorporated into granules, could be an important factor in determining the subsequent performance of that granulation, including key factors such as sticking to punches and bio-performance of the dosage form. It has previously been demonstrated that such attrition occurs in one common dry granulation process train; however, the fate of these comminuted particles in granules was not determined. An understanding of the phenomena of attrition and incorporation into granule will improve our ability to understand the performance of granulated systems, ultimately leading to an improvement in our ability to optimize and model the process. Unique feeding mechanisms, geometry, and milling systems of roller compaction equipment mean that attrition could be more or less substantial for any given equipment train. In this work, we examined attrition of API particles and their incorporation into granule in an equipment train from Gerteis, a commonly used equipment train for dry granulation. The results demonstrate that comminuted drug particles can exist free in post-milling blends of roller compaction equipment trains. This information can help better understand the performance of the granulations, and be incorporated into mechanistic models to optimize such processes.


Assuntos
Composição de Medicamentos/métodos , Tecnologia Farmacêutica/métodos , Tamanho da Partícula , Pós , Comprimidos
6.
J Neurochem ; 147(1): 71-83, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29989183

RESUMO

Elucidating how cannabinoids affect brain function is instrumental for the development of therapeutic tools aiming to mitigate 'on target' side effects of cannabinoid-based therapies. A single treatment with the cannabinoid receptor agonist, WIN 55,212-2, disrupts recognition memory in mice. Here, we evaluate how prolonged, intermittent (30 days) exposure to WIN 55,212-2 (1 mg/kg) alters recognition memory and impacts on brain metabolism and functional connectivity. We show that chronic, intermittent treatment with WIN 55,212-2 disrupts recognition memory (Novel Object Recognition Test) without affecting locomotion and anxiety-like behaviour (Open Field and Elevated Plus Maze). Through 14 C-2-deoxyglucose functional brain imaging we show that chronic, intermittent WIN 55,212-2 exposure induces hypometabolism in the hippocampal dorsal subiculum and in the mediodorsal nucleus of the thalamus, two brain regions directly involved in recognition memory. In addition, WIN 55,212-2 exposure induces hypometabolism in the habenula with a contrasting hypermetabolism in the globus pallidus. Through the application of the Partial Least Squares Regression (PLSR) algorithm to the brain imaging data, we observed that prolonged WIN 55,212-2 administration alters functional connectivity in brain networks that underlie recognition memory, including that between the hippocampus and prefrontal cortex, the thalamus and prefrontal cortex, and between the hippocampus and the perirhinal cortex. In addition, our results support disturbed lateral habenula and serotonin system functional connectivity following WIN 55,212-2 exposure. Overall, this study provides new insight into the functional mechanisms underlying the impact of chronic cannabinoid exposure on memory and highlights the serotonin system as a particularly vulnerable target.


Assuntos
Benzoxazinas/toxicidade , Encéfalo/efeitos dos fármacos , Agonistas de Receptores de Canabinoides/toxicidade , Memória/efeitos dos fármacos , Morfolinas/toxicidade , Naftalenos/toxicidade , Rede Nervosa/efeitos dos fármacos , Reconhecimento Psicológico/efeitos dos fármacos , Animais , Globo Pálido/efeitos dos fármacos , Globo Pálido/metabolismo , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Núcleo Mediodorsal do Tálamo/efeitos dos fármacos , Núcleo Mediodorsal do Tálamo/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Vias Neurais/efeitos dos fármacos , Córtex Pré-Frontal/efeitos dos fármacos
7.
Pharm Dev Technol ; 23(10): 964-977, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30320539

RESUMO

Following the first Manufacturing Classification System (MCS) paper, the team conducted surveys to establish which active pharmaceutical ingredient (API) properties were important when selecting or modifying materials to enable an efficient and robust pharmaceutical manufacturing process. The most commonly identified factors were (1) API particle size: small particle sizes are known to increase risk of processing issues; (2) Drug loading in the formulation: high drug loadings allow less opportunity to mitigate poor API properties through the use of excipients. The next step was to establish linkages with process decisions by identifying publicly-available proxies for these important parameters: dose (in place of drug loading) and BCS class (in place of particle size). Poorly-soluble API were seen as more likely to have controlled (smaller) particle size than more highly soluble API. Analysis of 435 regulatory filings revealed that higher doses and more poorly-soluble API was associated with more complex processing routes. Replacing the proxy factors with the original parameters should give the opportunity to demonstrate stronger trends. This assumption was tested by accessing a dataset relating to commercial tablet products. This showed that, for dry processes, a larger particle size was associated with higher achievable drug loading as determined by percolation threshold.


Assuntos
Composição de Medicamentos/métodos , Indústria Farmacêutica/métodos , Tamanho da Partícula , Preparações Farmacêuticas/administração & dosagem , Preparações Farmacêuticas/classificação , Administração Oral , Animais , Análise de Dados , Europa (Continente) , Humanos , Indústria Manufatureira/métodos , Preparações Farmacêuticas/química
8.
Cereb Cortex ; 24(2): 452-64, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23081884

RESUMO

Compromised functional integration between cerebral subsystems and dysfunctional brain network organization may underlie the neurocognitive deficits seen in psychiatric disorders. Applying topological measures from network science to brain imaging data allows the quantification of complex brain network connectivity. While this approach has recently been used to further elucidate the nature of brain dysfunction in schizophrenia, the value of applying this approach in preclinical models of psychiatric disease has not been recognized. For the first time, we apply both established and recently derived algorithms from network science (graph theory) to functional brain imaging data from rats treated subchronically with the N-methyl-D-aspartic acid (NMDA) receptor antagonist phencyclidine (PCP). We show that subchronic PCP treatment induces alterations in the global properties of functional brain networks akin to those reported in schizophrenia. Furthermore, we show that subchronic PCP treatment induces compromised functional integration between distributed neural systems, including between the prefrontal cortex and hippocampus, that have established roles in cognition through, in part, the promotion of thalamic dysconnectivity. We also show that subchronic PCP treatment promotes the functional disintegration of discrete cerebral subsystems and also alters the connectivity of neurotransmitter systems strongly implicated in schizophrenia. Therefore, we propose that sustained NMDA receptor hypofunction contributes to the pathophysiology of dysfunctional brain network organization in schizophrenia.


Assuntos
Encéfalo/fisiopatologia , Receptores de N-Metil-D-Aspartato/metabolismo , Algoritmos , Animais , Autorradiografia , Encéfalo/diagnóstico por imagem , Encéfalo/efeitos dos fármacos , Mapeamento Encefálico , Radioisótopos de Carbono , Desoxiglucose/metabolismo , Antagonistas de Aminoácidos Excitatórios/farmacologia , Hipocampo/diagnóstico por imagem , Hipocampo/efeitos dos fármacos , Hipocampo/fisiopatologia , Masculino , Vias Neurais/diagnóstico por imagem , Vias Neurais/efeitos dos fármacos , Vias Neurais/fisiopatologia , Fenciclidina/farmacologia , Córtex Pré-Frontal/diagnóstico por imagem , Córtex Pré-Frontal/efeitos dos fármacos , Córtex Pré-Frontal/fisiopatologia , Cintilografia , Ratos , Ratos Endogâmicos , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Esquizofrenia/fisiopatologia , Processamento de Sinais Assistido por Computador , Integração de Sistemas , Tálamo/diagnóstico por imagem , Tálamo/efeitos dos fármacos , Tálamo/fisiopatologia
9.
Emerg Med J ; 31(3): 207-9, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23413149

RESUMO

OBJECTIVE: To determine the association between the American Society of Anesthiologists (ASA) grade and the complication rate of patients receiving procedural sedation for relocation of hip prosthesis in an adult emergency department (ED) in the UK. DESIGN: Retrospective study of registry data from a large UK teaching hospital ED. Consecutive adult patients (aged 16 years and over) in whom ASA grade could be calculated, with an isolated dislocation of a hip prosthesis between 8 September 2006 and 16 April 2010 were included for analyses (n=303). The primary outcome measure was association between ASA and complication rate (any of desaturation <90%; apnoea; vomiting; aspiration; hypotension <90 mm Hg; cardiac arrest). Secondary outcome measures were relationship between ASA grade and procedural success, choice of sedative agent and sedation depth, and complications and choice of sedative agent, arrival time and sedation depth. RESULTS: There was no significant difference between ASA grade and the risk of complication (p=0.800). Moreover, there was no significant difference between ASA grade and procedural success (p=0.284), ASA and choice of sedative agent (p=0.243), or ASA and sedation depth (p=0.48). There was no association between complications and sedative agent (p=0.18), or complications and arrival time (p=0.12). There was a significant difference between sedative depth and complications (p<0.001). CONCLUSIONS: There is no clear association between a patient's physical status (ASA grade) and the risk of complications, chance of procedural success or choice of sedative agent in relocation of hip prostheses. There is a higher rate of complications with higher levels of sedation (p<0.001).


Assuntos
Sedação Consciente/efeitos adversos , Nível de Saúde , Luxação do Quadril/cirurgia , Prótese de Quadril , Complicações Pós-Operatórias , Falha de Prótese , Adulto , Idoso , Idoso de 80 Anos ou mais , Serviço Hospitalar de Emergência/estatística & dados numéricos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Reino Unido , Adulto Jovem
10.
Heliyon ; 10(13): e33549, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-39027499

RESUMO

Community Based Natural Resource Management (CBNRM) is presented as an equitable approach, particularly relative to strict types of Area-based conservation. In Zambia, traditional and formal, contemporary institutions were combined to leverage CBNRM for natural resource management. We investigate whether and how this shift in conservation approach and interaction between institutions works in practice, and to what extent it produces more equitable governance processes. We identified 30 key informants from NGOs and government departments via snowball sampling. We conducted 20 focus group discussions involving local community participants in three Game Management Areas (GMAs) adjacent to North Luangwa National Park. Focus groups were divided by age and gender to minimize any potential influence of unequal power relations. Data collection included informal discussions with individual community members and participant observation. We found that the customary roles held by chiefs gave them relative power over the Community resources board and made them gatekeepers for NGOs and government institutions. Instead of fostering community participation and empowerment, new CBNRM institutions have had the unintended consequence of increasing the customary chiefs' power through commercialization and bureaucratization of their positions. Rather than reinforcing local and indigenous institutions CBNRM has become a vehicle through which governments and NGOs centralize power and manufacture consent while weakening traditional institutions and reproducing existing patterns of inequity. This research provides unique insights into the workings of a CBNRM institution that is a hybrid between traditional (socially embedded) and Government (bureaucratic) institutions. We recommend that rather than simply setting up idealized institutions as a means to devolve power and enhance equity, the realisation of effective local participation and representation in CBNRM projects requires careful assessment of cultural contexts, local institutions and power dynamics.

11.
Ambio ; 2024 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-39023682

RESUMO

Drawing on 662 studies from 102 countries, we present a systematic review of published empirical studies about site-level biodiversity conservation initiated between 1970 and 2019. Within this sample, we find that knowledge production about the Global South is largely produced by researchers in the Global North, implying a neocolonial power dynamic. We also find evidence of bias in reported ecological outcomes linked to lack of independence in scientific studies, serving to uphold narratives about who should lead conservation. We explore relationships in the sample studies between conservation initiative types, the extent of Indigenous Peoples' and local communities' influence in governance, and reported social and ecological outcomes. Findings reveal positive ecological and social outcomes are strongly associated with higher levels of influence of Indigenous Peoples and local communities and their institutions, implying equity in conservation practice should be advanced not only for moral reasons, but because it can enhance conservation effectiveness.

12.
Int J Pharm ; 659: 124246, 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38777305

RESUMO

Wet granulation, a particle size enlargement process, can significantly enhance the critical quality attributes of powders and improve the ability to form tablets in pharmaceutical manufacturing. In this study, a mechanistic-based population balance model is applied to twin screw wet granulation. This model incorporated a recently developed breakage kernel specifically designed for twin screw granulation, along with nucleation, layering, and consolidation. Calibration and validation were performed on Hydrochlorothiazide and Acetaminophen formulations, which exhibit different particle size and wettability characteristics. Utilizing a compartmental experimental dataset, a comprehensive global sensitivity analysis identified critical inputs impacting quality attributes. The study revealed that the nucleation rate process model, effectively represented particle size distributions for both formulations. Adjustments to nucleation and breakage rate parameters, influenced by material properties and screw configuration, improved the model's accuracy. A model-driven workflow was proposed, offering step-by-step guidelines and facilitating PBM model usage, providing essential details for future active pharmaceutical ingredient (API) formulations.


Assuntos
Acetaminofen , Composição de Medicamentos , Hidroclorotiazida , Tamanho da Partícula , Acetaminofen/química , Composição de Medicamentos/métodos , Calibragem , Hidroclorotiazida/química , Fluxo de Trabalho , Pós , Molhabilidade , Química Farmacêutica/métodos , Comprimidos , Modelos Teóricos
13.
Artigo em Inglês | MEDLINE | ID: mdl-38521860

RESUMO

Meta-analysis of genome-wide association study data has implicated PDE4B in the pathogenesis of Alzheimer's disease (AD), the leading cause of senile dementia. PDE4B encodes one of four subtypes of cyclic adenosine monophosphate (cAMP)-specific phosphodiesterase-4 (PDE4A-D). To interrogate the involvement of PDE4B in the manifestation of AD-related phenotypes, the effects of a hypomorphic mutation (Pde4bY358C) that decreases PDE4B's cAMP hydrolytic activity were evaluated in the AppNL-G-F knock-in mouse model of AD using the Barnes maze test of spatial memory, 14C-2-deoxyglucose autoradiography, thioflavin-S staining of ß-amyloid (Aß) plaques, and inflammatory marker assay and transcriptomic analysis (RNA sequencing) of cerebral cortical tissue. At 12 months of age, AppNL-G-F mice exhibited spatial memory and brain metabolism deficits, which were prevented by the hypomorphic PDE4B in AppNL-G-F/Pde4bY358C mice, without a decrease in Aß plaque burden. RNA sequencing revealed that, among the 531 transcripts differentially expressed in AppNL-G-F versus wild-type mice, only 13 transcripts from four genes - Ide, Btaf1, Padi2, and C1qb - were differentially expressed in AppNL-G-F/Pde4bY358C versus AppNL-G-F mice, identifying their potential involvement in the protective effect of hypomorphic PDE4B. Our data demonstrate that spatial memory and cerebral glucose metabolism deficits exhibited by 12-month-old AppNL-G-F mice are prevented by targeted inhibition of PDE4B. To our knowledge, this is the first demonstration of a protective effect of PDE4B subtype-specific inhibition in a preclinical model of AD. It thus identifies PDE4B as a key regulator of disease manifestation in the AppNL-G-F model and a promising therapeutic target for AD.

14.
Int J Pharm ; 646: 123481, 2023 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-37805145

RESUMO

This work presents a granule size prediction approach applicable to diverse formulations containing new active pharmaceutical ingredients (APIs) in continuous twin-screw wet granulation. The approach consists of a surrogate selection method to identify similar materials with new APIs and a T-shaped partial least squares (T-PLS) model for granule size prediction across varying formulations and process conditions. We devised a surrogate material selection method, employing a combination of linear pre-processing and nonlinear classification algorithms, which effectively identified suitable surrogates for new materials. Using only material properties obtained through four characterization methods, our approach demonstrated its predictive prowess. The selected surrogate methods were seamlessly integrated with our developed T-PLS model, which was meticulously validated for high-dose formulations involving three new APIs. When surrogating new APIs based on Gaussian process classification, we achieved the lowest prediction errors, signifying the method's robustness. The predicted d-values were within the range of uncertainty bounds for all cases, except for d90 of API C. Notably, the approach offers a direct and efficient solution for early-phase formulation and process development, considerably reducing the need for extensive experimental work. By relying on just four material characterization methods, it streamlines the research process while maintaining a high degree of accuracy.


Assuntos
Parafusos Ósseos , Tecnologia Farmacêutica , Análise dos Mínimos Quadrados , Tamanho da Partícula , Preparações Farmacêuticas , Composição de Medicamentos , Comprimidos
15.
Commun Biol ; 6(1): 557, 2023 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-37225770

RESUMO

Autism spectrum disorders are more common in males, and have a substantial genetic component. Chromosomal 16p11.2 deletions in particular carry strong genetic risk for autism, yet their neurobiological impact is poorly characterised, particularly at the integrated systems level. Here we show that mice reproducing this deletion (16p11.2 DEL mice) have reduced GABAergic interneuron gene expression (decreased parvalbumin mRNA in orbitofrontal cortex, and male-specific decreases in Gad67 mRNA in parietal and insular cortex and medial septum). Metabolic activity was increased in medial septum, and in its efferent targets: mammillary body and (males only) subiculum. Functional connectivity was altered between orbitofrontal, insular and auditory cortex, and between septum and hippocampus/subiculum. Consistent with this circuit dysfunction, 16p11.2 DEL mice showed reduced prepulse inhibition, but enhanced performance in the continuous performance test of attentional ability. Level 1 autistic individuals show similarly heightened performance in the equivalent human test, also associated with parietal, insular-orbitofrontal and septo-subicular dysfunction. The data implicate cortical and septal GABAergic dysfunction, and resulting connectivity changes, as the cause of pre-attentional and attentional changes in autism.


Assuntos
Córtex Auditivo , Transtorno do Espectro Autista , Humanos , Animais , Masculino , Camundongos , Estruturas Cromossômicas , Deleção Cromossômica , Transtorno do Espectro Autista/genética , RNA Mensageiro
16.
Ambio ; 52(9): 1431-1447, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37103778

RESUMO

We argue that solutions-based research must avoid treating climate change as a merely technical problem, recognizing instead that it is symptomatic of the history of European and North American colonialism. It must therefore be addressed by decolonizing the research process and transforming relations between scientific expertise and the knowledge systems of Indigenous Peoples and of local communities. Partnership across diverse knowledge systems can be a path to transformative change only if those systems are respected in their entirety, as indivisible cultural wholes of knowledge, practices, values, and worldviews. This argument grounds our specific recommendations for governance at the local, national, and international scales. As concrete mechanisms to guide collaboration across knowledge systems, we propose a set of instruments based on the principles of consent, intellectual and cultural autonomy, and justice. We recommend these instruments as tools to ensure that collaborations across knowledge systems embody just partnerships in support of a decolonial transformation of relations between human communities and between humanity and the more-than-human world.


Assuntos
Colonialismo , Conhecimento , Humanos , Mudança Climática , Povos Indígenas
17.
Autism Res ; 15(4): 614-627, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35142069

RESUMO

2p16.3 deletion, involving NEUREXIN1 (NRXN1) heterozygous deletion, substantially increases the risk of developing autism and other neurodevelopmental disorders. We have a poor understanding of how NRXN1 heterozygosity impacts on brain function and cognition to increase the risk of developing the disorder. Here we characterize the impact of Nrxn1α heterozygosity on cerebral metabolism, in mice, using 14 C-2-deoxyglucose imaging. We also assess performance in an olfactory-based discrimination and reversal learning (OB-DaRL) task and locomotor activity. We use decision tree classifiers to test the predictive relationship between cerebral metabolism and Nrxn1α genotype. Our data show that Nrxn1α heterozygosity induces prefrontal cortex (medial prelimbic cortex, mPrL) hypometabolism and a contrasting dorsal raphé nucleus (DRN) hypermetabolism. Metabolism in these regions allows for the predictive classification of Nrxn1α genotype. Consistent with reduced mPrL glucose utilization, prefrontal cortex insulin receptor signaling is decreased in Nrxn1α+/- mice. Behaviorally, Nrxn1α+/- mice show enhanced learning of a novel discrimination, impaired reversal learning and an increased latency to make correct choices. In addition, male Nrxn1α+/- mice show hyperlocomotor activity. Correlative analysis suggests that mPrL hypometabolism contributes to the enhanced novel odor discrimination seen in Nrxn1α+/- mice, while DRN hypermetabolism contributes to their increased latency in making correct choices. The data show that Nrxn1α heterozygosity impacts on prefrontal cortex and serotonin system function, which contribute to the cognitive alterations seen in these animals. The data suggest that Nrxn1α+/- mice provide a translational model for the cognitive and behavioral alterations seen in autism and other neurodevelopmental disorders associated with 2p16.3 deletion. LAY SUMMARY: Deletion of the chromosomal region 2p16.3, involving reduced NEUREXIN1 gene expression, dramatically increases the risk of developing autism. Here, we show that reduced Neurexin1α expression, in mice, impacts on the prefrontal cortex and impairs cognitive flexibility. The data suggest that 2p16.3 deletion increases the risk of developing autism by impacting on the prefrontal cortex. Mice with the deletion are a useful model for testing new drugs to treat the cognitive flexibility problems experienced by people with autism.


Assuntos
Transtorno do Espectro Autista , Transtorno Autístico , Animais , Transtorno do Espectro Autista/genética , Modelos Animais de Doenças , Núcleo Dorsal da Rafe , Genótipo , Humanos , Masculino , Camundongos , Córtex Pré-Frontal/diagnóstico por imagem , Reversão de Aprendizagem
18.
J Alzheimers Dis ; 86(3): 1201-1220, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35180123

RESUMO

BACKGROUND: The Alzheimer's disease (AD)-associated amyloid-beta protein precursor (AßPP) can be cleaved by ß-site AßPP cleaving enzyme 1 (BACE1) and the γ-secretase complex to yield neurotoxic amyloid-ß (Aß) peptides. However, AßPP can also be cleaved in a 'non-amyloidogenic' manner either by α-secretase to produce soluble AßPP alpha (sAßPPα) (a fragment with neuroprotective/neurogenic functions) or through alternative BACE1-mediated 'beta prime' activity yielding soluble AßPP beta prime (sAßPPß'). OBJECTIVE: To determine whether sAßPPα depletion, as opposed to Aß peptide accumulation, contributes to cytotoxicity in AD-relevant SH-SY5Y neuroblastoma cell models. METHODS: AßPP proteolysis was characterized by immunoblotting in mock-, wild-type AßPP (wtAßPP)-, BACE1-, and Swedish mutant AßPP (SweAßPP)-transfected cells. AßPP beta prime cleavage was confirmed through secretase inhibitor studies and C-terminal fragment analysis. The roles of sAßPPα and sAßPPß' in cell viability were confirmed by overexpression studies. RESULTS: Despite producing enhanced Aß peptide levels, wtAßPP- and SweAßPP-transfected cells did not exhibit reduced viability whereas BACE1-transfected cells did. sAßPPα generation in SH-SY5Y-BACE1 cells was virtually ablated in lieu of BACE1-mediated sAßPPß' production. sAßPPα overexpression in SH-SY5Y-BACE1 cells restored viability whereas sAßPPß' overexpression decreased viability further. The anti-AßPP 6E10 antibody was shown to cross-react with sAßPPß'. CONCLUSION: sAßPPα depletion and/or sAßPPß' accumulation, but not elevated Aß peptide levels, represent the cytotoxic mechanism following BACE1 overexpression in SH-SY5Y cells. These data support the novel concept that competitive sAßPPα depletion by BACE1 beta prime activity might contribute to AD. The cross-reactivity of 6E10 with AßPPß'also questions whether previous studies assessing sAßPPα as a biomarker using this antibody should be revisited.


Assuntos
Doença de Alzheimer , Secretases da Proteína Precursora do Amiloide , Peptídeos beta-Amiloides , Doença de Alzheimer/metabolismo , Secretases da Proteína Precursora do Amiloide/metabolismo , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Ácido Aspártico Endopeptidases/metabolismo , Sobrevivência Celular , Humanos
19.
Cryst Growth Des ; 22(5): 3042-3059, 2022 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-35529067

RESUMO

The solvent-mediated crystal morphologies of the α and ß polymorphic forms of l-glutamic acid are presented. This work applies a digital mechanistically based workflow that encompasses calculation of the crystal lattice energy and its constituent intermolecular synthons, their interaction energies, and their key role in understanding and predicting crystal morphology as well as assessing the surface chemistry, topology, and solvent binding on crystal habit growth surfaces. Through a comparison between the contrasting morphologies of the conformational polymorphs of l-glutamic acid, this approach highlights how the interfacial chemistry of organic crystalline materials and their inherent anisotropic interactions with their solvation environments direct their crystal habit with potential impact on their further downstream processing behavior.

20.
UCL Open Environ ; 4: e050, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-37228477

RESUMO

Attempts to link human development and biodiversity conservation goals remain a constant feature of policy and practice related to protected areas (PAs). Underlying these approaches are narratives that simplify assumptions, shaping how interventions are designed and implemented. We examine evidence for five key narratives: 1) conservation is pro-poor; 2) poverty reduction benefits conservation; 3) compensation neutralises costs of conservation; 4) local participation is good for conservation; 5) secure tenure rights for local communities support effective conservation. Through a mixed-method synthesis combining a review of 100 peer-reviewed papers and 25 expert interviews, we examined if and how each narrative is supported or countered by the evidence. The first three narratives are particularly problematic. PAs can reduce material poverty, but exclusion brings substantial local costs to wellbeing, often felt by the poorest. Poverty reduction will not inevitably deliver on conservation goals and trade-offs are common. Compensation (for damage due to human wildlife conflict, or for opportunity costs), is rarely sufficient or commensurate with costs to wellbeing and experienced injustices. There is more support for narratives 4 and 5 on participation and secure tenure rights, highlighting the importance of redistributing power towards Indigenous Peoples and Local Communities in successful conservation. In light of the proposed expansion of PAs under the post-2020 Global Biodiversity Framework, we outline implications of our review for the enhancement and implementation of global targets in order to proactively integrate social equity into conservation and the accountability of conservation actors.

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