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1.
Adv Mater ; 35(47): e2304638, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37681325

RESUMO

Chronic diabetic wounds are a significant global healthcare challenge. Current strategies, such as biomaterials, cell therapies, and medical devices, however, only target a few pathological features and have limited efficacy. A powerful platform technology combining magneto-responsive hydrogel, cells, and wireless magneto-induced dynamic mechanical stimulation (MDMS) is developed to accelerate diabetic wound healing. The hydrogel encapsulates U.S. Food and Drug Administration (FDA)-approved fibroblasts and keratinocytes to achieve ∼3-fold better wound closure in a diabetic mouse model. MDMS acts as a nongenetic mechano-rheostat to activate fibroblasts, resulting in ∼240% better proliferation, ∼220% more collagen deposition, and improved keratinocyte paracrine profiles via the Ras/MEK/ERK pathway to boost angiogenesis. The magneto-responsive property also enables on-demand insulin release for spatiotemporal glucose regulation through increasing network deformation and interstitial flow. By mining scRNAseq data, a mechanosensitive fibroblast subpopulation is identified that can be mechanically tuned for enhanced proliferation and collagen production, maximizing therapeutic impact. The "all-in-one" system addresses major pathological factors associated with diabetic wounds in a single platform, with potential applications for other challenging wound types.


Assuntos
Diabetes Mellitus , Cicatrização , Camundongos , Animais , Diabetes Mellitus/terapia , Diabetes Mellitus/patologia , Queratinócitos , Colágeno , Hidrogéis/farmacologia
2.
Sci Data ; 9(1): 79, 2022 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-35277522

RESUMO

Long-term datasets documenting the evolution of coastal forms and processes, through the provision of recurring beach as well as shoreface morphological observations and accompanying time-series of environmental controls, remain difficult to collect and are rarely made available. However, they are increasingly needed to further our understanding of coastal change and to improve the models that will help planning what our future coast will be. This data descriptor presents the results of topographic and bathymetric surveys at Porsmilin, a macrotidal embayed beach situated in Brittany, northwest France. The Porsmilin beach survey program was launched in January 2003 by the Institut Universitaire Européen de la Mer (IUEM/Univ. Brest) and is continuing today in the framework of the French coastal observation service SNO-DYNALIT. The dataset contains over 16 years of monthly beach profile surveys and a large collection of repeated high-resolution subtidal and subaerial digital elevation models (DEMs). The dataset is accompanied by time-series of inshore waves and water levels, and enriched metadata, that will facilitate its future reuse in coastal research.

3.
Sci Adv ; 7(47): eabj1617, 2021 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-34797719

RESUMO

The confluence of wireless technology and biosensors offers the possibility to detect and manage medical conditions outside of clinical settings. Wound infections represent a major clinical challenge in which timely detection is critical for effective interventions, but this is currently hindered by the lack of a monitoring technology that can interface with wounds, detect pathogenic bacteria, and wirelessly transmit data. Here, we report a flexible, wireless, and battery-free sensor that provides smartphone-based detection of wound infection using a bacteria-responsive DNA hydrogel. The engineered DNA hydrogels respond selectively to deoxyribonucleases associated with pathogenic bacteria through tunable dielectric changes, which can be wirelessly detected using near-field communication. In a mouse acute wound model, we demonstrate that the wireless sensor can detect physiologically relevant amounts of Staphylococcus aureus even before visible manifestation of infection. These results demonstrate strategies for continuous infection monitoring, which may facilitate improved management of surgical or chronic wounds.

4.
Sci Adv ; 7(21)2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-34020961

RESUMO

Chronic wounds arise from interruption of normal healing due to many potential pathophysiological factors. Monitoring these multivariate factors can provide personalized diagnostic information for wound management, but current sensing technologies use complex laboratory tests or track a limited number of wound parameters. We report a flexible biosensing platform for multiplexed profiling of the wound microenvironment, inflammation, and infection state at the point of care. This platform integrates a sensor array for measuring inflammatory mediators [tumor necrosis factor-α, interleukin-6 (IL-6), IL-8, and transforming growth factor-ß1], microbial burden (Staphylococcus aureus), and physicochemical parameters (temperature and pH) with a microfluidic wound exudate collector and flexible electronics for wireless, smartphone-based data readout. We demonstrate in situ multiplexed monitoring in a mouse wound model and also profile wound exudates from patients with venous leg ulcers. This technology may facilitate more timely and personalized wound management to improve chronic wound healing outcomes.


Assuntos
Técnicas Biossensoriais , Sistemas Automatizados de Assistência Junto ao Leito , Animais , Humanos , Imunoensaio , Camundongos , Fator de Necrose Tumoral alfa , Cicatrização/fisiologia
5.
Clin Oral Investig ; 25(3): 1327-1335, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32623525

RESUMO

OBJECTIVES: Connexins are building blocks of membranous channels that form gap junctions and hemichannels. These channels are essential portals for information exchange and coordination during inflammation. Pathologic levels of these conduits may result in excessive inflammation and collateral destruction. This study aimed to analyse temporospatial levels of connexin 43 (Cx43) during pulpitis in extracted human teeth and in a rodent model. A specific interest was directed at the pulpal stroma as it is conserved during vital pulp therapy. MATERIALS AND METHODS: Pulpal tissues were attained from human extracted teeth of various pulpal inflammatory stages and fixed for cryosections. Pulpal exposures were created in bilateral maxillary molars in Sprague-Dawley rats. Rats were sacrificed at days 1 to 5 post-exposure. Immunofluorescence histology was performed to detect Cx43, markers for inflammation, and cell death. Immunofluorescent levels in the pulpal stroma at 3 sites (wound/near/far) were matched to pulpal condition (human) or days post-exposure (rodent). RESULTS: Cx43 upregulation was observed with increased severity of pulpitis both in humans and rodent model. The upregulation appeared to be global and included distant regions. Elevated levels of neutrophils were present in advanced pulpitis. Apoptosis and necroptosis seem to be upregulated in human samples as Cx43 levels rose. CONCLUSIONS: We observed a disseminated upregulation of Cx43 throughout the pulpal stroma as inflammation became advanced. This observation may facilitate cell death signal transfer or represent overt levels of purinergic signalling that leads to pro-inflammatory conditions. CLINICAL RELEVANCE: Cx43 downregulation may represent a potential therapeutic approach to enable resolution of pulpal inflammation.


Assuntos
Conexina 43 , Pulpite , Animais , Conexina 43/metabolismo , Polpa Dentária/metabolismo , Ratos , Ratos Sprague-Dawley , Regulação para Cima
6.
Philos Trans A Math Phys Eng Sci ; 378(2168): 20190222, 2020 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-32063173

RESUMO

'Sponge City' is the term used to describe the Chinese government's approach to urban surface water management. The concept was conceived in 2014 in response to an increasing incidence of urban flooding or water-logging in Chinese cities. While ambitious and far-reaching in its aim (of decreasing national flood risk, increasing water supply and improving water quality), the initiative must be implemented by individual subprovincial or municipal-level government entities. Thus, while the concept is similar to sustainable drainage systems (SuDS) in the UK (or low-impact development (LID) in the USA), it is developing with different regional characteristics, and during continuing rapid urbanization. Indeed, the increasing use of national rather than international examples of best practice reflects a growing body of knowledge that has evolved since the start of the Sponge City initiative. In this paper, interpretation and development of the national Sponge City guidelines are assessed for the Ningbo Municipality, an affluent and rapidly expanding city on China's low-lying east coast. While climate, geology and socio-economic factors can all be seen to influence the way that national guidelines are implemented, project financing, integration and assessment are found to be of increasing influence. This article is part of the theme issue 'Urban flood resilience'.

7.
Biomed Opt Express ; 10(12): 6114-6128, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31853389

RESUMO

Raman spectroscopy has demonstrated great potential for skin wound assessment. Given that biochemical changes in wound healing is depth dependent as the skin is a layered structure, depth sensitive Raman spectroscopy could enhance the power of Raman spectroscopy in this application. Considering the critical importance of rodent studies in the field of skin wound assessment, it is necessary to develop and validate a system that can perform depth sensitive measurements in rat skin with a proper target depth range. In this manuscript, we report the design, optimization and evaluation of a new snapshot depth-sensitive Raman instrument for rat skin measurements. The optical design and optimization process are presented first. The depth sensitive measurement performance is characterized on both ex vivo porcine skin with a gradient of layer thickness and ex vivo rat skin samples with wounds. The statistical analysis of the measured Raman spectra demonstrates the feasibility of differentiation between the wound edge and healthy skin. Moreover, the accuracy of classification improves monotonically as more data from new depths are used, which implies that each depth offers additional information useful for classification. This instrument demonstrates the ability to perform snapshot depth sensitive Raman measurements from rat skin, which paves the way towards in vivo preclinical studies of rat skin wounds.

8.
Cancers (Basel) ; 11(12)2019 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-31766723

RESUMO

The poor prognosis of head and neck squamous cell carcinoma (HNSCC) is partly due to the lack of reliable predictive markers. Connexin 43 (Cx43) protein and its cell-communication channels have been assigned tumor suppressor functions while the anti-apoptotic Bcl-2 (B-cell lymphoma-2) protein has been associated with negative prognostic significance in cancer. This study aimed to test the role of Cx43 protein on Bcl-2 expression, tumor progression and response to taxane-based treatment in HNSCC. Human papillomavirus (HPV) negative HNSCC cell lines were tested for paclitaxel sensitivity through measuring apoptosis induction, cell viability and changes in Cx43 and Bcl-2 levels using flow cytometry, cell viability assay, immunocytochemistry and western blot. Inhibition of Cx43 expression using siRNA increased Bcl-2 protein levels in SCC25 (tongue squamous cell carcinoma) cells, while forced Cx43 expression reduced Bcl-2 levels and supported paclitaxel cytotoxicity in FaDu (hypopharynx squamous cell carcinoma) cells. In vitro results were in line with protein expression and clinicopathological features tested in tissue microarray samples of HNSCC patients. Our data demonstrate that elevated Cx43 and reduced Bcl-2 levels may indicate HNSCC sensitivity to taxane-based treatments. On the contrary, silencing of the Cx43 gene GJA1 (gap junction protein alpha-1) can result in increased Bcl-2 expression and reduced paclitaxel efficiency. Clinical tumor-based analysis also confirmed the inverse correlation between Cx43 and Bcl-2 expression.

9.
Korean J Food Sci Anim Resour ; 38(4): 653-663, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30206425

RESUMO

Lamb has long been considered a traditional meal within Australia; however as consumer preferences have changed since the 1950's, consumption of lamb has decreased from the 1980's. This is the result of changing societal roles, particularly for females, decreasing household sizes and increasing awareness of the impact of food choices on human health. Since the 1980's improvement of farm practices and increases in genetic gains has addressed part of this decline by increasing the amount of lean meat and decreasing fat in lamb retail cuts. Yet, this has created a challenge for the industry to utilise the larger carcases now being produced. Thus, a whole value chain approach to increasing consumption has been undertaken through several research programs to create cuts which suit the modern consumer, examine nutritional and eating quality and increase adoption of value added cuts. Therefore, this paper outlines this history of changing consumer patterns and the consequent research to address these changes.

10.
Eur J Immunol ; 48(6): 1014-1019, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29510451

RESUMO

Pressure ulcers are a chronic problem for patients or the elderly who require extended periods of bed rest. The formation of ulcers is due to repeated cycles of ischemia-reperfusion (IR), which initiates an inflammatory response. Advanced ulcers disrupt the skin barrier, resulting in further complications. To date, the immunological aspect of skin IR has been understudied, partly due to the complexity of the skin immune cells. Through a combination of mass cytometry, confocal imaging and intravital multiphoton imaging, this study establishes a workflow for multidimensionality single cell analysis of skin myeloid cell responses in the context of IR injury with high spatiotemporal resolution. The data generated has provided us with previously uncharacterized insights into the distinct cellular behavior of resident dendritic cells (DCs) and recruited neutrophils post IR. Of interest, we observed a drop in DDC numbers in the IR region, which was subsequently replenished 48h post IR. More importantly, in these cells, we observe an attenuated response to repeated injuries, which may have implications in the subsequent wound healing process.


Assuntos
Células Dendríticas/imunologia , Neutrófilos/imunologia , Úlcera por Pressão/imunologia , Traumatismo por Reperfusão/imunologia , Pele/patologia , Idoso , Animais , Antígeno CD11c/genética , Antígeno CD11c/metabolismo , Movimento Celular , Células Cultivadas , Modelos Animais de Doenças , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Análise de Célula Única
11.
J Infect Dis ; 216(12): 1644-1654, 2017 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-29045678

RESUMO

Enterococcus faecalis is one of the most frequently isolated bacterial species in wounds yet little is known about its pathogenic mechanisms in this setting. Here, we used a mouse wound excisional model to characterize the infection dynamics of E faecalis and show that infected wounds result in 2 different states depending on the initial inoculum. Low-dose inocula were associated with short-term, low-titer colonization whereas high-dose inocula were associated with acute bacterial replication and long-term persistence. High-dose infection and persistence were also associated with immune cell infiltration, despite suppression of some inflammatory cytokines and delayed wound healing. During high-dose infection, the multiple peptide resistance factor, which is involved in resisting immune clearance, contributes to E faecalis fitness. These results comprehensively describe a mouse model for investigating E faecalis wound infection determinants, and suggest that both immune modulation and resistance contribute to persistent, nonhealing wounds.


Assuntos
Enterococcus faecalis/imunologia , Enterococcus faecalis/patogenicidade , Infecções por Bactérias Gram-Positivas/patologia , Evasão da Resposta Imune , Infecção dos Ferimentos/patologia , Animais , Modelos Animais de Doenças , Enterococcus faecalis/crescimento & desenvolvimento , Infecções por Bactérias Gram-Positivas/microbiologia , Masculino , Camundongos Endogâmicos C57BL , Infecção dos Ferimentos/microbiologia
12.
J Environ Manage ; 196: 80-90, 2017 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-28284142

RESUMO

The aim of this research was to assess the spatial and temporal distribution of surface water pollution within a reticular canal system typical of those found in the lower Yangtze River Delta (YRD). For this purpose, surface water quality data was collected from a drainage canal that bisected the southeast district of Ningbo Municipality (Zhejiang) from 2013 to 2015. The sampling transect was designed to represent the change in land-use from the agriculture dominated rural hinterland, to the predominantly urban city-centre. To calculate the representative land-use fraction of each sampling location, the contributing area was defined using an uni-directional 1 km vector line-buffer around the 'upstream' section of canal. The spatial and temporal variation of EC, DO, NH3 and turbidity indicated a measureable difference between the urban and rural sections of the channel. Water quality indicators were most sensitive to urban and parkland land-use types. The study yielded an increased spatial resolution to knowledge of water-quality variability in the urban environment compared to previous studies within the YRD region. The results were used to make recommendations for the development of an effective long-term strategy for the improvement in surface water quality in this region.


Assuntos
Monitoramento Ambiental , Qualidade da Água , China , Cidades , Rios , Poluição da Água
13.
Elife ; 52016 11 22.
Artigo em Inglês | MEDLINE | ID: mdl-27874832

RESUMO

Seizures are often followed by sensory, cognitive or motor impairments during the postictal phase that show striking similarity to transient hypoxic/ischemic attacks. Here we show that seizures result in a severe hypoxic attack confined to the postictal period. We measured brain oxygenation in localized areas from freely-moving rodents and discovered a severe hypoxic event (pO2 < 10 mmHg) after the termination of seizures. This event lasted over an hour, is mediated by hypoperfusion, generalizes to people with epilepsy, and is attenuated by inhibiting cyclooxygenase-2 or L-type calcium channels. Using inhibitors of these targets we separated the seizure from the resulting severe hypoxia and show that structure specific postictal memory and behavioral impairments are the consequence of this severe hypoperfusion/hypoxic event. Thus, epilepsy is much more than a disease hallmarked by seizures, since the occurrence of postictal hypoperfusion/hypoxia results in a separate set of neurological consequences that are currently not being treated and are preventable.


Assuntos
Comportamento Animal , Encéfalo/fisiopatologia , Ciclo-Oxigenase 2/metabolismo , Hipóxia/patologia , Convulsões/complicações , Animais , Ratos Long-Evans
14.
Thromb Haemost ; 116(5): 852-867, 2016 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-27488046

RESUMO

Prolonged vascular hyperpermeability is a common feature of many diseases. Vascular hyperpermeability is typically associated with changes in the expression patterns of adherens and tight junction proteins. Here, we focus on the less-appreciated contribution of gap junction proteins (connexins) to basal vascular permeability and endothelial dysfunction. First, we assess the association of connexins with endothelial barrier integrity by introducing tools used in connexin biology and relating the findings to customary readouts in vascular biology. Second, we explore potential mechanistic ties between connexins and junction regulation. Third, we review the role of connexins in microvascular organisation and development, focusing on interactions of the endothelium with mural cells and tissue-specific perivascular cells. Last, we see how connexins contribute to the interactions between the endothelium and components of the immune system, by using neutrophils as an example. Mounting evidence of crosstalk between connexins and other junction proteins suggests that we rethink the way in which different junction components contribute to endothelial barrier function. Given the multiple points of connexin-mediated communication arising from the endothelium, there is great potential for synergism between connexin-targeted inhibitors and existing immune-targeted therapeutics. As more drugs targeting connexins progress through clinical trials, it is hoped that some might prove effective at countering vascular hyperpermeability.


Assuntos
Permeabilidade Capilar , Conexinas/fisiologia , Endotélio Vascular/fisiologia , Humanos
15.
Drugs Aging ; 33(8): 575-83, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27510615

RESUMO

Neuropathic pain frequently affects older people, who generally also have several comorbidities. Elderly patients are often poly-medicated, which increases the risk of drug-drug interactions. These patients, especially those with cognitive problems, may also have restricted communication skills, making pain evaluation difficult and pain treatment challenging. Clinicians and other healthcare providers need a decisional algorithm to optimize the recognition and management of neuropathic pain. We present a decisional algorithm developed by a multidisciplinary group of experts, which focuses on pain assessment and therapeutic options for the management of neuropathic pain, particularly in the elderly. The algorithm involves four main steps: (1) detection, (2) evaluation, (3) treatment, and (4) re-evaluation. The detection of neuropathic pain is an essential step in ensuring successful management. The extent of the impact of the neuropathic pain is then assessed, generally with self-report scales, except in patients with communication difficulties who can be assessed using behavioral scales. The management of neuropathic pain frequently requires combination treatments, and recommended treatments should be prescribed with caution in these elderly patients, taking into consideration their comorbidities and potential drug-drug interactions and adverse events. This algorithm can be used in the management of neuropathic pain in the elderly to ensure timely and adequate treatment by a multidisciplinary team.


Assuntos
Algoritmos , Neuralgia/tratamento farmacológico , Manejo da Dor/métodos , Medição da Dor/métodos , Guias de Prática Clínica como Assunto , Idoso , Comorbidade , Interações Medicamentosas , Humanos , Neuralgia/diagnóstico , Inquéritos e Questionários
16.
Bioeng Transl Med ; 1(3): 357-364, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-29313020

RESUMO

Near-infrared (NIR) light-responsive liposomes are attractive carriers for targeted and controlled drug delivery to the superficial organ or tissue (e.g., skin). This work describes the development of NIR-responsive liposomes by incorporating gold nanostars within liposomes composed of Phospholipon 90 g and cholesterol. Following cellular delivery, photothermal effect around the gold nanostar upon NIR stimulation induces microcavitation and liposome phase transition which consequently triggers the release of encapsulated molecules. Taking GFP plasmid as an example, we demonstrate enhanced gene transfection into fibroblasts following NIR treatment.

17.
Adv Drug Deliv Rev ; 94: 77-95, 2015 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-26415888

RESUMO

Generating porous topographic substrates, by mimicking the native extracellular matrix (ECM) to promote the regeneration of damaged bone tissues, is a challenging process. Generally, scaffolds developed for bone tissue regeneration support bone cell growth and induce bone-forming cells by natural proteins and growth factors. Limitations are often associated with these approaches such as improper scaffold stability, and insufficient cell adhesion, proliferation, differentiation, and mineralization with less growth factor expression. Therefore, the use of engineered nanoparticles has been rapidly increasing in bone tissue engineering (BTE) applications. The electrospray technique is advantageous over other conventional methods as it generates nanomaterials of particle sizes in the micro/nanoscale range. The size and charge of the particles are controlled by regulating the polymer solution flow rate and electric voltage. The unique properties of nanoparticles such as large surface area-to-volume ratio, small size, and higher reactivity make them promising candidates in the field of biomedical engineering. These nanomaterials are extensively used as therapeutic agents and for drug delivery, mimicking ECM, and restoring and improving the functions of damaged organs. The controlled and sustained release of encapsulated drugs, proteins, vaccines, growth factors, cells, and nucleotides from nanoparticles has been well developed in nanomedicine. This review provides an insight into the preparation of nanoparticles by electrospraying technique and illustrates the use of nanoparticles in drug delivery for promoting bone tissue regeneration.


Assuntos
Regeneração Óssea/efeitos dos fármacos , Regeneração Óssea/fisiologia , Sistemas de Liberação de Medicamentos/métodos , Nanopartículas/química , Engenharia Tecidual/métodos , Antibacterianos/administração & dosagem , Materiais Biocompatíveis , Preparações de Ação Retardada , Humanos , Células-Tronco Mesenquimais/metabolismo , Osteoblastos/metabolismo , Tamanho da Partícula , Polímeros/química , Porosidade , Propriedades de Superfície , Tecnologia Farmacêutica , Alicerces Teciduais
18.
Mol Brain ; 7: 51, 2014 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-25063346

RESUMO

BACKGROUND: Manipulation of gene expression via recombinant viral vectors and creation of transgenic knock-out/in animals has revolutionized our understanding of genes that play critical roles during neuronal development and pathophysiology of neurological disorders. Recently, target-specific genetic manipulations are made possible to perform in combination with specific Cre-lines, albeit costly, labor-intensive and time consuming. Thus, alternative methods of gene manipulations to address important biological questions are highly desirable. In this study, we utilized in utero electroporation technique which involves efficient delivery of hindbrain-specific enhancer/promoter construct, Krox20 into the third ventricle of live mouse embryo to investigate green fluorescent protein (GFP) expression pattern in mouse auditory brainstem and other hindbrain neurons. RESULTS: We created a GFP/DNA construct containing a Krox20 B enhancer and ß-globin promoter to drive GFP expression in the hindbrain via injection into the third ventricle of E12 to E13.5 mice. Electrical currents were applied directly to the embryonic hindbrain to allow DNA uptake into the cell. Confocal images were then acquired from fixed brain slices to analyze GFP expression in mouse whole brain at different postnatal stages (P6-P21). By using a cell-type specific enhancer as well as region specific injection and electroporation, robust GFP expression in the cerebellum and auditory brainstem but not in the forebrain was observed. GFP expression in calyx of Held terminals was more robust in P15 mice. In contrast, GFP expression in MNTB neurons was more prevalent in >P15 compared to

Assuntos
Tronco Encefálico/embriologia , Tronco Encefálico/metabolismo , Orelha/inervação , Eletroporação/métodos , Técnicas de Transferência de Genes , Rombencéfalo/embriologia , Rombencéfalo/metabolismo , Animais , Clonagem Molecular , Proteína 2 de Resposta de Crescimento Precoce/metabolismo , Elementos Facilitadores Genéticos/genética , Feminino , Proteínas de Fluorescência Verde/metabolismo , Camundongos , Neurônios/metabolismo , Sinapses/metabolismo
19.
Channels (Austin) ; 4(5): 375-89, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20699644

RESUMO

Low voltage-activated T-type calcium (Ca) channels contribute to the normal development of the heart and are also implicated in pathophysiological states such as cardiac hypertrophy. Functionally distinct T-type Ca channel isoforms can be generated by alternative splicing from each of three different T-type genes (Ca(V)3.1, Ca(V)3.2,Ca(V)3.3), although it remains to be described whether specific splice variants are associated with developmental states and pathological conditions. We aimed to identify and functionally characterize Ca(V)3.2 T-type Ca channel alternatively spliced variants from newborn animals and to compare with adult normotensive and spontaneously hypertensive rats (SHR). DNA sequence analysis of full-length Ca(V)3.2 cDNA generated from newborn heart tissue identified ten major regions of alternative splicing, the more common variants of which were analyzed by quantitative real-time PCR (qRT-PCR) and also subject to functional examination by whole-cell patch clamp. The main findings are that: (1) cardiac Ca(V)3.2 T-type Ca channels are subject to considerable alternative splicing, (2) there is preferential expression of Ca(V)3.2(-25) splice variant channels in newborn rat heart with a developmental shift in adult heart that results in approximately equal levels of expression of both (+25) and (-25) exon variants, (3) in the adult stage of hypertensive rats there is a both an increase in overall Ca(V)3.2 expression and a shift towards expression of Ca(V)3.2(+25) containing channels as the predominant form, and (4) alternative splicing confers a variant-specific voltage-dependent facilitation of Ca(V)3.2 channels. We conclude that Ca(V)3.2 alternative splicing generates significant T-type Ca channel structural and functional diversity with potential implications relevant to cardiac developmental and pathophysiological states.


Assuntos
Processamento Alternativo/fisiologia , Canais de Cálcio Tipo T/genética , Cardiomegalia/genética , Coração/crescimento & desenvolvimento , Fatores Etários , Animais , Animais Recém-Nascidos , Canais de Cálcio Tipo T/fisiologia , Técnicas Eletrofisiológicas Cardíacas/métodos , Técnicas de Patch-Clamp , Ratos , Ratos Endogâmicos SHR
20.
Fitoterapia ; 81(7): 826-9, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20472040

RESUMO

This investigation focuses on the in vitro neuroactive properties of pinostrobin, a substituted flavanone from Cajanus cajan (L.) Millsp. of the Fabaceae family. We demonstrate that pinostrobin inhibits voltage-gated sodium channels of mammalian brain (IC(50)=23 µM) based on the ability of this substance to suppress the depolarizing effects of the sodium channel-selective activator veratridine in a synaptoneurosomal preparation from mouse brain. The resting membrane potential of synaptoneurosomes was unaffected by pinostrobin. The pharmacological profile of pinostrobin resembles that of depressant drugs that block sodium channels.


Assuntos
Encéfalo/efeitos dos fármacos , Cajanus/química , Flavanonas/farmacologia , Bloqueadores dos Canais de Sódio/farmacologia , Canais de Sódio/efeitos dos fármacos , Animais , Encéfalo/fisiologia , Camundongos , Camundongos Endogâmicos , Fármacos Neuromusculares/farmacologia , Folhas de Planta , Sinaptossomos/efeitos dos fármacos , Sinaptossomos/fisiologia , Veratridina/farmacologia
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