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1.
Cell ; 154(5): 1100-1111, 2013 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-23993098

RESUMO

Retinal photoreceptors entrain the circadian system to the solar day. This photic resetting involves cAMP response element binding protein (CREB)-mediated upregulation of Per genes within individual cells of the suprachiasmatic nuclei (SCN). Our detailed understanding of this pathway is poor, and it remains unclear why entrainment to a new time zone takes several days. By analyzing the light-regulated transcriptome of the SCN, we have identified a key role for salt inducible kinase 1 (SIK1) and CREB-regulated transcription coactivator 1 (CRTC1) in clock re-setting. An entrainment stimulus causes CRTC1 to coactivate CREB, inducing the expression of Per1 and Sik1. SIK1 then inhibits further shifts of the clock by phosphorylation and deactivation of CRTC1. Knockdown of Sik1 within the SCN results in increased behavioral phase shifts and rapid re-entrainment following experimental jet lag. Thus SIK1 provides negative feedback, acting to suppress the effects of light on the clock. This pathway provides a potential target for the regulation of circadian rhythms.


Assuntos
Relógios Circadianos , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais , Transporte Ativo do Núcleo Celular , Animais , Ritmo Circadiano , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Técnicas de Silenciamento de Genes , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Serina-Treonina Quinases/genética , RNA Interferente Pequeno/metabolismo , Opsinas de Bastonetes/genética , Opsinas de Bastonetes/metabolismo , Núcleo Supraquiasmático/metabolismo , Fatores de Transcrição/metabolismo , Transcrição Gênica
2.
BMC Biol ; 22(1): 208, 2024 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-39278902

RESUMO

BACKGROUND: The natural light environment is far more complex than that experienced by animals under laboratory conditions. As a burrowing species, wild mice are able to self-modulate their light exposure, a concept known as light environment sampling behaviour. By contrast, under laboratory conditions mice have little opportunity to exhibit this behaviour. To address this issue, here we introduce a simple nestbox paradigm to allow mice to self-modulate their light environment. Dark nestboxes fitted with passive infrared sensors were used to monitor locomotor activity, circadian entrainment, decision making and light environment sampling behaviour. RESULTS: Under these conditions, mice significantly reduce their light exposure to an average of just 0.8 h across a 24 h period. In addition, mice show a distinct pattern of light environment sampling behaviour, with peaks at dawn and dusk under a ramped light dark cycle. Furthermore, we show that the timing of light environment sampling behaviour depends upon endogenous circadian rhythms and is abolished in mice lacking a circadian clock, indicating a feedback loop between light, the circadian clock and behaviour. CONCLUSIONS: Our results highlight the important role of behaviour in modifying the light signals available for circadian entrainment under natural conditions.


Assuntos
Ritmo Circadiano , Luz , Animais , Ritmo Circadiano/fisiologia , Camundongos/fisiologia , Comportamento Animal/fisiologia , Camundongos Endogâmicos C57BL , Masculino , Atividade Motora/fisiologia , Fotoperíodo , Relógios Circadianos/fisiologia
3.
Proc Natl Acad Sci U S A ; 118(39)2021 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-34556572

RESUMO

Light provides the primary signal for entraining circadian rhythms to the day/night cycle. In addition to rods and cones, the retina contains a small population of photosensitive retinal ganglion cells (pRGCs) expressing the photopigment melanopsin (OPN4). Concerns have been raised that exposure to dim artificial lighting in the evening (DLE) may perturb circadian rhythms and sleep patterns, and OPN4 is presumed to mediate these effects. Here, we examine the effects of 4-h, 20-lux DLE on circadian physiology and behavior in mice and the role of OPN4 in these responses. We show that 2 wk of DLE induces a phase delay of ∼2 to 3 h in mice, comparable to that reported in humans. DLE-induced phase shifts are unaffected in Opn4-/- mice, indicating that rods and cones are capable of driving these responses in the absence of melanopsin. DLE delays molecular clock rhythms in the heart, liver, adrenal gland, and dorsal hippocampus. It also reverses short-term recognition memory performance, which is associated with changes in preceding sleep history. In addition, DLE modifies patterns of hypothalamic and cortical cFos signals, a molecular correlate of recent neuronal activity. Together, our data show that DLE causes coordinated realignment of circadian rhythms, sleep patterns, and short-term memory process in mice. These effects are particularly relevant as DLE conditions-due to artificial light exposure-are experienced by the majority of the populace on a daily basis.


Assuntos
Ritmo Circadiano , Luz , Memória de Curto Prazo/fisiologia , Células Ganglionares da Retina/fisiologia , Opsinas de Bastonetes/fisiologia , Sono/fisiologia , Animais , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Células Ganglionares da Retina/citologia
4.
J Transl Med ; 19(1): 483, 2021 11 27.
Artigo em Inglês | MEDLINE | ID: mdl-34838033

RESUMO

BACKGROUND: The evaluation of translational health research is important for various reasons such as the research impact assessment, research funding allocation, accountability, and strategic research policy formulation. The purpose of this study was to evaluate the research productivity, strength and diversity of research collaboration networks and impact of research supported by a large biomedical research centre in the United Kingdom (UK). METHODS: Bibliometric analysis of research publications by translational researchers affiliated with the National Institute for Health Research (NIHR) Oxford Biomedical Research Centre (BRC) from April 2012 to March 2017. RESULTS: Analysis included 2377 translational research publications that were published during the second 5-year funding period of the NIHR Oxford BRC. Author details were available for 99.75% of the publications with DOIs (2359 of 2365 with DOIs), and the number of authors per publication was median 9 (mean = 18.03, SD = 3.63, maximum = 2467 authors). Author lists also contained many consortia, groups, committees, and teams (n = 165 in total), with 1238 additional contributors, where membership was reported. The BRC co-authorship i.e., research collaboration network for these publications involved 20,229 nodes (authors, of which 1606 nodes had Oxford affiliations), and approximately 4.3 million edges (authorship linkages). Articles with a valid DOIs (2365 of 2377, 99.5%) were collectively cited more than 155,000 times and the average Field Citation Ratio was median 6.75 (geometric mean = 7.12) while the average Relative Citation Ratio was median 1.50 (geometric mean = 1.83) for the analysed publications. CONCLUSIONS: The NIHR Oxford BRC generated substantial translational research publications and facilitated a huge collaborative network of translational researchers working in complex structures and consortia, which shows success across the whole of this BRC funding period. Further research involving continued uptake of unique persistent identifiers and the tracking of other research outputs such as clinical innovations and patents would allow a more detailed understanding of large research enterprises such as NIHR BRCs in the UK.


Assuntos
Pesquisa Biomédica , Pesquisa Translacional Biomédica , Autoria , Bibliometria , Publicações , Reino Unido
5.
Hum Mol Genet ; 27(15): 2589-2603, 2018 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-29718372

RESUMO

Melanopsin (OPN4) is an opsin photopigment expressed within intrinsically photosensitive retinal ganglion cells (ipRGCs) that mediate non-image forming (NIF) responses to light. Two single-nucleotide polymorphisms (SNPs) in human melanopsin (hOPN4), Pro10Leu and Thr394Ile, have recently been associated with abnormal NIF responses to light, including seasonal affective disorder. It has been suggested these behavioural changes are due to altered melanopsin signalling. However, there is currently no direct evidence to support this. Here we have used ipRGC-specific delivery of hOPN4 wild-type (WT), Pro10Leu or Thr394Ile adeno-associated viruses (AAV) to determine the functional consequences of hOPN4 SNPs on melanopsin-driven light responses and associated behaviours. Immunohistochemistry confirmed hOPN4 AAVs exclusively transduced mouse ipRGCs. Behavioural phenotyping performed before and after AAV injection demonstrated that both hOPN4 Pro10Leu and Thr394Ile could functionally rescue pupillary light responses and circadian photoentrainment in Opn4-/- mice, with no differences in NIF behaviours detected for animals expressing either SNP compared to hOPN4 WT. Multi-electrode array recordings revealed that ipRGCs expressing hOPN4 Thr394Ile exhibit melanopsin-driven light responses with significantly attenuated response amplitude, decreased sensitivity and faster offset kinetics compared to hOPN4 WT. IpRGCs expressing hOpn4 Pro10Leu also showed reduced response amplitude. Collectively these data suggest Thr394Ile and Pro10Leu may be functionally significant SNPs, which result in altered melanopsin signalling. To our knowledge, this study provides the first direct evidence for the effects of hOPN4 polymorphisms on melanopsin-driven light responses and NIF behaviours in vivo, providing further insight into the role of these SNPs in melanopsin function and human physiology.


Assuntos
Polimorfismo de Nucleotídeo Único , Células Ganglionares da Retina/fisiologia , Opsinas de Bastonetes/genética , Opsinas de Bastonetes/metabolismo , Animais , Dependovirus/genética , Regulação da Expressão Gênica , Humanos , Luz , Transdução de Sinal Luminoso , Camundongos Mutantes , Camundongos Transgênicos , Mutação de Sentido Incorreto , Pupila/fisiologia
6.
Hum Mol Genet ; 26(20): 3869-3882, 2017 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-29016847

RESUMO

The discovery of genetic variants influencing sleep patterns can shed light on the physiological processes underlying sleep. As part of a large clinical sequencing project, WGS500, we sequenced a family in which the two male children had severe developmental delay and a dramatically disturbed sleep-wake cycle, with very long wake and sleep durations, reaching up to 106-h awake and 48-h asleep. The most likely causal variant identified was a novel missense variant in the X-linked GRIA3 gene, which has been implicated in intellectual disability. GRIA3 encodes GluA3, a subunit of AMPA-type ionotropic glutamate receptors (AMPARs). The mutation (A653T) falls within the highly conserved transmembrane domain of the ion channel gate, immediately adjacent to the analogous residue in the Grid2 (glutamate receptor) gene, which is mutated in the mouse neurobehavioral mutant, Lurcher. In vitro, the GRIA3(A653T) mutation stabilizes the channel in a closed conformation, in contrast to Lurcher. We introduced the orthologous mutation into a mouse strain by CRISPR-Cas9 mutagenesis and found that hemizygous mutants displayed significant differences in the structure of their activity and sleep compared to wild-type littermates. Typically, mice are polyphasic, exhibiting multiple sleep bouts of sleep several minutes long within a 24-h period. The Gria3A653T mouse showed significantly fewer brief bouts of activity and sleep than the wild-types. Furthermore, Gria3A653T mice showed enhanced period lengthening under constant light compared to wild-type mice, suggesting an increased sensitivity to light. Our results suggest a role for GluA3 channel activity in the regulation of sleep behavior in both mice and humans.


Assuntos
Deficiência Intelectual/genética , Mutação Puntual , Receptores de AMPA/genética , Receptores de AMPA/metabolismo , Transtornos do Sono-Vigília/genética , Adulto , Sequência de Aminoácidos , Animais , Sequência de Bases , Modelos Animais de Doenças , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL
7.
Nucleic Acids Res ; 45(17): 9860-9873, 2017 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-28973476

RESUMO

The master circadian pacemaker in mammals is located in the suprachiasmatic nuclei (SCN) which regulate physiology and behaviour, as well as coordinating peripheral clocks throughout the body. Investigating the function of the SCN has often focused on the identification of rhythmically expressed genes. However, not all genes critical for SCN function are rhythmically expressed. An alternative strategy is to characterize those genes that are selectively enriched in the SCN. Here, we examined the transcriptome of the SCN and whole brain (WB) of mice using meta-analysis of publicly deposited data across a range of microarray platforms and RNA-Seq data. A total of 79 microarrays were used (24 SCN and 55 WB samples, 4 different microarray platforms), alongside 17 RNA-Seq data files (7 SCN and 10 WB). 31 684 MGI gene symbols had data for at least one platform. Meta-analysis using a random effects model for weighting individual effect sizes (derived from differential expression between relevant SCN and WB samples) reliably detected known SCN markers. SCN-enriched transcripts identified in this study provide novel insights into SCN function, including identifying genes which may play key roles in SCN physiology or provide SCN-specific drivers.


Assuntos
Relógios Circadianos/genética , Ritmo Circadiano/genética , Redes Reguladoras de Genes , Núcleo Supraquiasmático/fisiologia , Transcriptoma , Animais , Química Encefálica , Mineração de Dados , Conjuntos de Dados como Assunto , Ontologia Genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Anotação de Sequência Molecular , Análise de Sequência com Séries de Oligonucleotídeos , Análise de Sequência de RNA
8.
J Neurosci ; 37(13): 3555-3567, 2017 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-28264977

RESUMO

Circadian rhythms optimize physiology and behavior to the varying demands of the 24 h day. The master circadian clock is located in the suprachiasmatic nuclei (SCN) of the hypothalamus and it regulates circadian oscillators in tissues throughout the body to prevent internal desynchrony. Here, we demonstrate for the first time that, under standard 12 h:12 h light/dark (LD) cycles, object, visuospatial, and olfactory recognition performance in C57BL/6J mice is consistently better at midday relative to midnight. However, under repeated exposure to constant light (rLL), recognition performance becomes desynchronized, with object and visuospatial performance better at subjective midday and olfactory performance better at subjective midnight. This desynchrony in behavioral performance is mirrored by changes in expression of the canonical clock genes Period1 and Period2 (Per1 and Per2), as well as the immediate-early gene Fos in the SCN, dorsal hippocampus, and olfactory bulb. Under rLL, rhythmic Per1 and Fos expression is attenuated in the SCN. In contrast, hippocampal gene expression remains rhythmic, mirroring object and visuospatial performance. Strikingly, Per1 and Fos expression in the olfactory bulb is reversed, mirroring the inverted olfactory performance. Temporal desynchrony among these regions does not result in arrhythmicity because core body temperature and exploratory activity rhythms persist under rLL. Our data provide the first demonstration that abnormal lighting conditions can give rise to temporal desynchrony between autonomous circadian oscillators in different regions, with different consequences for performance across different sensory domains. Such a dispersed network of dissociable circadian oscillators may provide greater flexibility when faced with conflicting environmental signals.SIGNIFICANCE STATEMENT A master circadian clock in the suprachiasmatic nuclei (SCN) of the hypothalamus regulates physiology and behavior across the 24 h day by synchronizing peripheral clocks throughout the brain and body. Without the SCN, these peripheral clocks rapidly become desynchronized. Here, we provide a unique demonstration that, under lighting conditions in which the central clock in the SCN is dampened, peripheral oscillators in the hippocampus and olfactory bulb become desynchronized, along with the behavioral processes mediated by these clocks. Multiple clocks that adopt different phase relationships may enable processes occurring in different brain regions to be optimized to specific phases of the 24 h day. Moreover, such a dispersed network of dissociable circadian clocks may provide greater flexibility when faced with conflicting environmental signals (e.g., seasonal changes in photoperiod).


Assuntos
Ritmo Circadiano/fisiologia , Percepção de Forma/fisiologia , Memória/fisiologia , Mascaramento Perceptivo/fisiologia , Reconhecimento Psicológico/fisiologia , Olfato/fisiologia , Navegação Espacial/fisiologia , Animais , Sincronização Cortical/fisiologia , Masculino , Rememoração Mental/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Reconhecimento Visual de Modelos/fisiologia , Estimulação Luminosa/métodos , Análise e Desempenho de Tarefas
9.
Lancet ; 390(10090): 145-154, 2017 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-28551075

RESUMO

BACKGROUND: England and Wales have one of the highest frequencies of autopsy in the world. Implementation of post-mortem CT (PMCT), enhanced with targeted coronary angiography (PMCTA), in adults to avoid invasive autopsy would have cultural, religious, and potential economic benefits. We aimed to assess the diagnostic accuracy of PMCTA as a first-line technique in post-mortem investigations. METHODS: In this single-centre (Leicester, UK), prospective, controlled study, we selected cases of natural and non-suspicious unnatural death referred to Her Majesty's (HM) Coroners. We excluded cases younger than 18 years, known to have had a transmittable disease, or who weighed more than 125 kg. Each case was assessed by PMCTA, followed by autopsy. Pathologists were masked to the PMCTA findings, unless a potential risk was shown. The primary endpoint was the accuracy of the cause of death diagnosis from PMCTA against a gold standard of autopsy findings, modified by PMCTA findings only if additional substantially incontrovertible findings were identified. FINDINGS: Between Jan 20, 2010, and Sept 13, 2012, we selected 241 cases, for which PMCTA was successful in 204 (85%). Seven cases were excluded from the analysis because of procedural unmasking or no autopsy data, as were 24 cases with a clear diagnosis of traumatic death before investigation; 210 cases were included. In 40 (19%) cases, predictable toxicology or histology testing accessible by PMCT informed the result. PMCTA provided a cause of death in 193 (92%) cases. A major discrepancy with the gold standard was noted in 12 (6%) cases identified by PMCTA, and in nine (5%) cases identified by autopsy (because of specific findings on PMCTA). The frequency of autopsy and PMCTA discrepancies were not significantly different (p=0·65 for major discrepancies and p=0·21 for minor discrepancies). Cause of death given by PMCTA did not overlook clinically significant trauma, occupational lung disease, or reportable disease, and did not significantly affect the overall population data for cause of death (p≥0·31). PMCTA was better at identifying trauma and haemorrhage (p=0·008), whereas autopsy was better at identifying pulmonary thromboembolism (p=0·004). INTERPRETATION: For most sudden natural adult deaths investigated by HM Coroners, PMCTA could be used to avoid invasive autopsy. The gold standard of post-mortem investigations should include both PMCT and invasive autopsy. FUNDING: National Institute for Health Research.


Assuntos
Autopsia/métodos , Morte Súbita/etiologia , Tomografia Computadorizada por Raios X/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Causas de Morte , Hemorragia Cerebral/diagnóstico por imagem , Angiografia Coronária , Médicos Legistas , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/diagnóstico por imagem , Estudos Prospectivos , Adulto Jovem
10.
Lancet ; 385 Suppl 1: S20, 2015 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-26312842

RESUMO

BACKGROUND: We have previously shown that patients with endometrial carcinoma express elevated concentrations of the endocannabinoid, anandamide (AEA), in both their plasma and their endometrial tissue and that the endometrial carcinoma cell line, Ishikawa, contains the receptors to which AEA binds. Several studies have reported that human and rodent cancer cell lines die in response to high AEA concentrations. The incidence of endometrial carcinoma continues to escalate and, although surgical treatment has improved, morbidity and mortality rates have not. A move towards a novel non-surgical therapeutic option is thus required, and the endocannabinoid system provides a good candidate target. We aimed to investigate the effects of AEA on the survival and proliferation of an endometrial carcinoma cell model. METHODS: This prospective basic research study was conducted at a UK teaching hospital. Ishikawa cells were cultured in vitro, and a range of AEA concentrations (0-10 000 nM) were added to the cells. The effect of AEA was measured at different timepoints (4, 18, 24, 48, and 72 h). Primary outcome was cell proliferation and cell viability as measured with a commercial proliferation-apoptosis assay in which assay colour at 420 nm is directly proportional to cell density. One-way ANOVA was performed with Prism (version 7). FINDINGS: Ishikawa cells were sensitive to AEA-mediated cytotoxicity in a pseudo dose-dependent manner. AEA caused a significant decrease in cell number only at concentrations above 1000 nM (mean 28·1% [SE 7·8], n=12; p<0·0001). The decrease in cell viability that occurred at 4, 18, and 24 h was partly restored at 48 and 72 h suggesting that the AEA growth inhibitory effect is time limiting. INTERPRETATION: Our results show that AEA induces a decrease in Ishikawa cell number probably through inhibition of cell proliferation rather than cell death. These data suggest that the increased plasma and tissue AEA concentrations observed in patients with endometrial cancer is a counter mechanism against further cancer growth and points to the endocannabinoid system as a potentially new therapeutic target. FUNDING: University Hospitals of Leicester NHS Trust.

11.
Race Cl ; 58(1): 34-54, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28479657

RESUMO

This article tells the hitherto untold story of how different Pakistani organisations mobilised in response to racist violence and harassment in the east London Borough of Tower Hamlets (1968-1970). In telling this story, the authors analyse the problematic nature of official and public understandings of, and responses to, racist violence, and how it distorted the lives of racialised minorities. Drawing on original archival research carried out in 2014, this piece identifies the emergence of two distinct political repertoires from within the Pakistani community: the integrationist approach and the autonomous approach. The integrationist approach involving the Pakistani Welfare Association (PWA) and the National Federation of Pakistani Associations (NFPA) tried to address the problem through existing local state 'race relations' apparatuses and mainstream political channels, while at the same time re-establishing consent for the police as the agents of law and order. In contrast, a network of Black Power groups, anti-imperialists and socialists led by the Pakistani Progressive Party (PPP) and the Pakistani Workers' Union (PWU) challenged both the local political leadership and the authority of the police in Tower Hamlets, while also undermining the stereotype of Asian people as 'weak' and 'passive'. In recovering this lost episode of resistance to 'Paki-bashing', unleashed in the aftermath of Enoch Powell's inflammatory speeches, this essay makes a contribution to the history of autonomous anti-racist collective action undertaken by racialised minorities in Britain.

12.
Mol Hum Reprod ; 21(9): 723-35, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26124453

RESUMO

Real-time quantitative RT-PCR (qRT-PCR) is a powerful technique used for the relative quantification of target genes, using reference (housekeeping) genes for normalization to ensure the generation of accurate and robust data. A systematic examination of the suitability of endogenous reference genes for gene expression studies in endometrial cancer tissues is absent. The aims of this study were therefore to identify and evaluate from the thirty-two possible reference genes from a TaqMan(®) array panel their suitability as an internal control gene. The mathematical software packages geNorm qBasePLUS identified Pumilio homolog 1 (Drosophila) (PUM1), ubiquitin C (UBC), phosphoglycerate kinase (PGK1), mitochondrial ribosomal protein L19 (MRPL19) and peptidylpropyl isomerase A (cyclophilin A) (PPIA) as the best reference gene combination, whilst NormFinder identified MRPL19 as the best single reference gene, with importin 8 (IPO8) and PPIA being the best combination of two reference genes. BestKeeper ranked MRPL19 as the most stably expressed gene. In addition, the study was validated by examining the relative expression of a test gene, which encodes the cannabinoid receptor 1 (CB1). A significant difference in CB1 mRNA expression between malignant and normal endometrium using MRPL19, PPIA, and IP08 in combination was observed. The use of MRPL19, IPO8 and PPIA was identified as the best reference gene combination for the normalization of gene expression levels in endometrial carcinoma. This study demonstrates that the arbitrary selection of endogenous control reference genes for normalization in qRT-PCR studies of endometrial carcinoma, without validation, risks the production of inaccurate data and should therefore be discouraged.


Assuntos
Biomarcadores Tumorais/genética , Carcinoma Endometrioide/genética , Neoplasias do Endométrio/genética , Perfilação da Expressão Gênica/normas , Reação em Cadeia da Polimerase em Tempo Real/normas , Algoritmos , Carcinoma Endometrioide/patologia , Estudos de Casos e Controles , Ciclofilina A/genética , Neoplasias do Endométrio/patologia , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Proteínas Mitocondriais/genética , Gradação de Tumores , Valor Preditivo dos Testes , Receptor CB1 de Canabinoide/genética , Valores de Referência , Reprodutibilidade dos Testes , Proteínas Ribossômicas/genética , Software , beta Carioferinas/genética
13.
Exp Eye Res ; 132: 161-73, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25579607

RESUMO

Recent advances in technology have greatly increased our ability to identify genetic variants in individuals with retinal disease. However, determining which are likely to be pathogenic remains a challenging task. Using a transgenic coneless (cl) mouse model, together with rodless (rd/rd) and rodless/coneless (rd/rd cl) mice, we have characterised patterns of gene expression in the rod and cone photoreceptors at a genome-wide level. We examined the expression of >27,000 genes in the mice lacking rods, cones or both and compared them with wild type animals. We identified a list of 418 genes with highly significant changes in expression in one or more of the transgenic strains. Pathway analysis confirmed that expected Gene Ontology terms such as phototransduction were over-represented amongst these genes. However, many of these genes have no previously known function in the retina. Gene set enrichment analysis further demonstrated that the mouse orthologues of known human retinal disease genes were significantly enriched amongst those genes with decreased expression. Comparison of our data to human disease loci with no known causal genetic changes has highlighted genes with significant changes in expression making these strong candidates for further screening. These data add to the current literature through the utilisation of the specific cl and rd/rd cl models. Moreover, this study identifies genes that appear to be implicated in photoreceptor function thereby providing a valuable filter for variants identified by high-throughput sequencing in individuals with retinal disease.


Assuntos
Células Fotorreceptoras Retinianas Cones/metabolismo , Doenças Retinianas/genética , Células Fotorreceptoras Retinianas Bastonetes/metabolismo , Animais , Modelos Animais de Doenças , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Camundongos , Camundongos Transgênicos
14.
Exp Eye Res ; 97(1): 148-53, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22197749

RESUMO

Recombinant adeno-associated virus type 2 (AAV2) vectors have shown great promise in current ophthalmology clinical trials targeting gene delivery to the retinal pigment epithelium (RPE). To treat the majority of retinal diseases, however, gene delivery would need to be targeted to photoreceptor neurons of the outer retina. AAV2 pseudotyped with the AAV5 capsid (AAV2/5) has shown far greater transduction efficiency in photoreceptors compared to standard AAV2 vectors. For clinical trial applications using gene therapy, it is helpful to generate pre-clinical data in human cells wherever possible. There is however very little data, indeed some controversy, as to whether AAV2/5 can be used effectively in differentiated neurons in culture. In this study we show that transduction of the human neuroblastoma cell line SH-SY5Y with recombinant AAV2/5 expressing GFP is well tolerated. Furthermore, we explore the mechanism whereby exposure to retinoic acid (RA) and the phorbol ester 12-O-Tetradecanoylphorbol-13- acetate (TPA) can induce this cell line to differentiate into a stable population of human neurons, with significantly increased levels of AAV2/5 transduction. These observations may be helpful for assessing AAV2/5 vectors in vitro, particularly where it is necessary to generate pre-clinical data for clinical trials of gene therapy to the human central nervous system.


Assuntos
Carcinógenos/farmacologia , Dependovirus/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Proteínas de Fluorescência Verde/genética , Neoplasias da Retina/genética , Retinoblastoma/genética , Acetato de Tetradecanoilforbol/farmacologia , Proteínas Mutadas de Ataxia Telangiectasia , Proteínas de Ciclo Celular/genética , Diferenciação Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Proteínas de Ligação a DNA/genética , Vetores Genéticos , Células HEK293 , Humanos , Proteínas Serina-Treonina Quinases/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Receptores do Fator de Crescimento Derivado de Plaquetas/genética , Neoplasias da Retina/patologia , Retinoblastoma/patologia , Proteínas de Ligação a Tacrolimo/genética , Transdução Genética , Tretinoína/farmacologia , Células Tumorais Cultivadas , Proteínas Supressoras de Tumor/genética
15.
Pharmacol Rev ; 61(1): 39-61, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19293145

RESUMO

Alzheimer's disease (AD), the major contributor to dementia in the elderly, involves accumulation in the brain of extracellular plaques containing the beta-amyloid protein (Abeta) and intracellular neurofibrillary tangles of hyperphosphorylated tau protein. AD is also characterized by a loss of neurons, particularly those expressing nicotinic acetylcholine receptors (nAChRs), thereby leading to a reduction in nAChR numbers. The Abeta(1-42) protein, which is toxic to neurons, is critical to the onset and progression of AD. The discovery of new drug therapies for AD is likely to be accelerated by an improved understanding of the mechanisms whereby Abeta causes neuronal death. We examine the evidence for a role in Abeta(1-42) toxicity of nAChRs; paradoxically, nAChRs can also protect neurons when activated by nicotinic ligands. Abeta peptides and nicotine differentially activate several intracellular signaling pathways, including the phosphatidylinositol 3-kinase/v-akt murine thymoma viral oncogene homolog pathway, the extracellular signal-regulated kinase/mitogen-activated protein kinase, and JAK-2/STAT-3 pathways. These pathways control cell death or survival and the secretion of Abeta peptides. We propose that understanding the differential activation of these pathways by nicotine and/or Abeta(1-42) may offer the prospect of new routes to therapy for AD.


Assuntos
Doença de Alzheimer , Peptídeos beta-Amiloides/fisiologia , Fragmentos de Peptídeos/fisiologia , Receptores Nicotínicos/fisiologia , Doença de Alzheimer/etiologia , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Animais , Humanos , Transdução de Sinais
16.
PLoS Pathog ; 5(7): e1000517, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19609360

RESUMO

Parasitic nematodes are of medical and veterinary importance, adversely affecting human health and animal welfare. Ascaris suum is a gastrointestinal parasite of pigs; in addition to its veterinary significance it is a good model of the human parasite Ascaris lumbricoides, estimated to infect approximately 1.4 billion people globally. Anthelmintic drugs are essential to control nematode parasites, and nicotinic acetylcholine receptors (nAChRs) on nerve and muscle are the targets of cholinergic anthelmintics such as levamisole and pyrantel. Previous genetic analyses of nematode nAChRs have been confined to Caenorhabditis elegans, which is phylogenetically distinct from Ascaris spp. and many other important parasites. Here we report the cloning and expression of two nAChR subunit cDNAs from A. suum. The subunits are very similar in sequence to C. elegans UNC-29 and UNC-38, are expressed on muscle cells and can be expressed robustly in Xenopus oocytes to form acetylcholine-, nicotine-, levamisole- and pyrantel-sensitive channels. We also demonstrate that changing the stoichiometry of the receptor by injecting different ratios of the subunit cRNAs can reproduce two of the three pharmacological subtypes of nAChR present in A. suum muscle cells. When the ratio was 5:1 (Asu-unc-38ratioAsu-unc-29), nicotine was a full agonist and levamisole was a partial agonist, and oocytes responded to oxantel, but not pyrantel. At the reverse ratio (1:5 Asu-unc-38ratioAsu-unc-29), levamisole was a full agonist and nicotine was a partial agonist, and the oocytes responded to pyrantel, but not oxantel. These results represent the first in vitro expression of any parasitic nicotinic receptor and show that their properties are substantially different from those of C. elegans. The results also show that changing the expression level of a single receptor subunit dramatically altered the efficacy of some anthelmintic drugs. In vitro expression of these subunits may permit the development of parasite-specific screens for future anthelmintics.


Assuntos
Ascaris suum/metabolismo , Proteínas de Helminto/metabolismo , Receptores Nicotínicos/metabolismo , Sequência de Aminoácidos , Animais , Antinematódeos/farmacocinética , Ascaris suum/citologia , Ascaris suum/genética , Proteínas de Caenorhabditis elegans/genética , Proteínas de Transporte/genética , Relação Dose-Resposta a Droga , Sistemas de Liberação de Medicamentos , Expressão Gênica , Proteínas de Helminto/química , Proteínas de Helminto/genética , Imuno-Histoquímica , Microscopia de Fluorescência , Dados de Sequência Molecular , Nicotina/metabolismo , Oócitos/metabolismo , Técnicas de Patch-Clamp , Multimerização Proteica , Subunidades Proteicas , RNA Complementar/metabolismo , Receptores Nicotínicos/biossíntese , Receptores Nicotínicos/química , Receptores Nicotínicos/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Alinhamento de Sequência
17.
Gynecol Obstet Invest ; 71(4): 217-24, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21160148

RESUMO

BACKGROUND AND AIM: To study the characteristics of the inner (IM) and outer (OM) myometrium in the presence and absence of uterine adenomyosis. METHODS: Case control blinded comparison carried out in a university department. Morphometric features of the myometrium were studied in uteri from pre- and postmenopausal women with and without uterine adenomyosis as the sole pathology. Uteri were also divided according to the phase of the cycle and examined using immunohistochemistry and image analysis. RESULTS: Cell density and total nuclear area were statistically significantly greater in the IM compared to OM, in pre- and postmenopausal women, in both the adenomyosis and control uteri. The difference in nuclear size was statistically significant only in the premenopausal group. The change from the IM to the OM in cell density and total nuclear area was gradual with no distinct zonation. Examined features did not vary with cycle phase. Both the IM and OM in adenomyosis exhibited lower cell density and larger nuclei compared to controls. In adenomyosis, immunostaining for α-smooth muscle actin, desmin and Ki-67 was consistent with myometrial hyperplasia and hypertrophy. CONCLUSIONS: There are clear differences between the IM and the OM but the transition is gradual, with no distinct zonation. Adenomyosis is characterised by reduced cell density, and increased nuclear size and features of hyperplasia and hypertrophy that are not confined to the IM.


Assuntos
Endometriose/patologia , Miométrio/patologia , Doenças Uterinas/patologia , Estudos de Casos e Controles , Contagem de Células , Núcleo Celular/patologia , Desmina/análise , Feminino , Humanos , Imuno-Histoquímica , Fenótipo , Pós-Menopausa , Pré-Menopausa , Útero/química , Útero/patologia , Vimentina/análise
19.
Methods Mol Biol ; 2130: 233-247, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33284449

RESUMO

Circadian rhythms are 24-h cycles in physiology and behavior that occur in virtually all organisms. These processes are not simply driven by changes in the external environment as they persist under constant conditions, providing evidence for an internal biological clock. In mammals, this clock is located in the hypothalamic suprachiasmatic nuclei (SCN) and is based upon an intracellular mechanism composed of a transcriptional-translational feedback loop composed of a number of core clock genes. However, a clock is of no use unless it can be set to the correct time. The primary time cue for the molecular clock in the SCN is light detected by the eye. The photoreceptors involved in this process include the rods and cones that mediate vision, as well as the recently identified melanopsin-expressing photosensitive retinal ganglion cells (pRGCs). Light information is conveyed to the SCN via the retinohypothalamic tract, resulting in an intracellular signaling cascade which converges on cAMP-response elements in the promoters of several key clock genes. Over the last two decades a number of studies have investigated the transcriptional response of the SCN to light stimuli with the aim of further understanding these molecular signaling pathways. Here we provide an overview of these studies and provide protocols for studying the molecular responses to light in the SCN clock.


Assuntos
Relógios Circadianos , Microdissecção e Captura a Laser/métodos , Visão Ocular , Animais , Camundongos , Proteoma/genética , Proteoma/metabolismo , Células Ganglionares da Retina/metabolismo , Células Ganglionares da Retina/fisiologia , Núcleo Supraquiasmático/metabolismo , Núcleo Supraquiasmático/fisiologia , Transcriptoma , Vias Visuais/metabolismo , Vias Visuais/fisiologia
20.
Transl Psychiatry ; 11(1): 588, 2021 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-34782594

RESUMO

Dysfunction of the glutamate α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor GluA1 subunit and deficits in synaptic plasticity are implicated in schizophrenia and sleep and circadian rhythm disruption. To investigate the role of GluA1 in circadian and sleep behaviour, we used wheel-running, passive-infrared, and video-based home-cage activity monitoring to assess daily rest-activity profiles of GluA1-knockout mice (Gria1-/-). We showed that these mice displayed various circadian abnormalities, including misaligned, fragmented, and more variable rest-activity patterns. In addition, they showed heightened, but transient, behavioural arousal to light→dark and dark→light transitions, as well as attenuated nocturnal-light-induced activity suppression (negative masking). In the hypothalamic suprachiasmatic nuclei (SCN), nocturnal-light-induced cFos signals (a molecular marker of neuronal activity in the preceding ~1-2 h) were attenuated, indicating reduced light sensitivity in the SCN. However, there was no change in the neuroanatomical distribution of expression levels of two neuropeptides-vasoactive intestinal peptide (VIP) and arginine vasopressin (AVP)-differentially expressed in the core (ventromedial) vs. shell (dorsolateral) SCN subregions and both are known to be important for neuronal synchronisation within the SCN and circadian rhythmicity. In the motor cortex (area M1/M2), there was increased inter-individual variability in cFos levels during the evening period, mirroring the increased inter-individual variability in locomotor activity under nocturnal light. Finally, in the spontaneous odour recognition task GluA1 knockouts' short-term memory was impaired due to enhanced attention to the recently encountered familiar odour. These abnormalities due to altered AMPA-receptor-mediated signalling resemble and may contribute to sleep and circadian rhythm disruption and attentional deficits in different modalities in schizophrenia.


Assuntos
Ritmo Circadiano , Receptores de AMPA , Animais , Sinais (Psicologia) , Camundongos , Núcleo Supraquiasmático , Ácido alfa-Amino-3-hidroxi-5-metil-4-isoxazol Propiônico
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