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1.
Cell ; 161(7): 1553-65, 2015 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-26073944

RESUMO

Hematopoietic stem cells (HSCs) reside in hypoxic niches within bone marrow and cord blood. Yet, essentially all HSC studies have been performed with cells isolated and processed in non-physiologic ambient air. By collecting and manipulating bone marrow and cord blood in native conditions of hypoxia, we demonstrate that brief exposure to ambient oxygen decreases recovery of long-term repopulating HSCs and increases progenitor cells, a phenomenon we term extraphysiologic oxygen shock/stress (EPHOSS). Thus, true numbers of HSCs in the bone marrow and cord blood are routinely underestimated. We linked ROS production and induction of the mitochondrial permeability transition pore (MPTP) via cyclophilin D and p53 as mechanisms of EPHOSS. The MPTP inhibitor cyclosporin A protects mouse bone marrow and human cord blood HSCs from EPHOSS during collection in air, resulting in increased recovery of transplantable HSCs. Mitigating EPHOSS during cell collection and processing by pharmacological means may be clinically advantageous for transplantation.


Assuntos
Medula Óssea , Sangue Fetal/citologia , 1-Metil-4-Fenil-1,2,3,6-Tetra-Hidropiridina , Animais , Peptidil-Prolil Isomerase F , Ciclofilinas/metabolismo , Feminino , Transplante de Células-Tronco Hematopoéticas/instrumentação , Células-Tronco Hematopoéticas/citologia , Humanos , Hipóxia , Camundongos , Camundongos Endogâmicos C57BL , Oxigênio/metabolismo , Proteína Supressora de Tumor p53/metabolismo
2.
J Neurosci ; 44(19)2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38565288

RESUMO

Excitotoxicity and the concurrent loss of inhibition are well-defined mechanisms driving acute elevation in excitatory/inhibitory (E/I) balance and neuronal cell death following an ischemic insult to the brain. Despite the high prevalence of long-term disability in survivors of global cerebral ischemia (GCI) as a consequence of cardiac arrest, it remains unclear whether E/I imbalance persists beyond the acute phase and negatively affects functional recovery. We previously demonstrated sustained impairment of long-term potentiation (LTP) in hippocampal CA1 neurons correlating with deficits in learning and memory tasks in a murine model of cardiac arrest/cardiopulmonary resuscitation (CA/CPR). Here, we use CA/CPR and an in vitro ischemia model to elucidate mechanisms by which E/I imbalance contributes to ongoing hippocampal dysfunction in male mice. We reveal increased postsynaptic GABAA receptor (GABAAR) clustering and function in the CA1 region of the hippocampus that reduces the E/I ratio. Importantly, reduced GABAAR clustering observed in the first 24 h rebounds to an elevation of GABAergic clustering by 3 d postischemia. This increase in GABAergic inhibition required activation of the Ca2+-permeable ion channel transient receptor potential melastatin-2 (TRPM2), previously implicated in persistent LTP and memory deficits following CA/CPR. Furthermore, we find Ca2+-signaling, likely downstream of TRPM2 activation, upregulates Ca2+/calmodulin-dependent protein kinase II (CaMKII) activity, thereby driving the elevation of postsynaptic inhibitory function. Thus, we propose a novel mechanism by which inhibitory synaptic strength is upregulated in the context of ischemia and identify TRPM2 and CaMKII as potential pharmacological targets to restore perturbed synaptic plasticity and ameliorate cognitive function.


Assuntos
Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina , Transdução de Sinais , Canais de Cátion TRPM , Animais , Masculino , Camundongos , Isquemia Encefálica/metabolismo , Região CA1 Hipocampal/metabolismo , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Neurônios GABAérgicos/metabolismo , Parada Cardíaca/complicações , Parada Cardíaca/metabolismo , Hipocampo/metabolismo , Camundongos Endogâmicos C57BL , Inibição Neural/fisiologia , Receptores de GABA-A/metabolismo , Canais de Cátion TRPM/metabolismo
3.
J Environ Manage ; 357: 120799, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38581895

RESUMO

Policies and management decisions in the marine environment are driven in part by public sentiment which can grow more intense during hazard events like Harmful Algae Blooms (HABs). The public conversations on social media sites like Twitter (before X) reveal the polarized nature of HABs through nuanced language and sentiment. This article uses mixed methods of machine learned topic modeling and inductive qualitative coding to describe the ways the long-term 2017-2019 Karenia brevis "red tide" bloom were politicized across Florida's South West coast. It finds that there are topical differences in keywords related to place (e.g. beach, Florida, coast), agent (individual or organization), and epistemic values (reliance on scientific and/or media reports). These topical differences demonstrate different levels of politicization and partisanship in qualitative analysis. Conceptually, this research demonstrates the ways different dimensions of a long-duration marine hazard can be polarized. Regarding management, this research provides insights to political and organizational stakeholders and the gaps in the discourse shaping marine hazards which can be used to strategically guide future social media engagement to manage politicization. What if all the careful work that resource and environmental managers do can be undone by simple, seemingly uncontroversial words? In an era of increased environmental and marine distress-coupled with short format communication-the ways environmental managers choose their words is crucial, even between ostensibly inconsequential nouns like "red tide" or "algae bloom." Policies and management decisions in the marine environment are driven in part by public sentiment which can grow more intense during hazard events like Harmful Algae Blooms (HABs). The public conversations on social media sites like Twitter (before X) reveal the polarized nature of HABs through nuanced language and sentiment. This article relies on mining social media posts, and uses mixed methods of machine-learned topic modeling and human-driven inductive qualitative coding to describe the ways the long-term 2017-2019 Karenia brevis "red tide" blooms were politicized across Florida's South West coast. It finds that there are topical differences in keywords related to place (e.g. beach, Florida, coast), agent (individual or organization), and epistemic values (reliance on scientific and/or media reports). These topical differences demonstrate different levels of politicization and partisanship in qualitative analysis. Conceptually, this research demonstrates the ways different dimensions of a long-duration marine hazard can be polarized. Regarding management, this research provides insights to political and organizational stakeholders and the gaps in the discourse shaping marine hazards which can be used to strategically guide future social media engagement to manage politicization.


Assuntos
Dinoflagellida , Mídias Sociais , Humanos , Proliferação Nociva de Algas , Toxinas Marinhas/análise , Florida
4.
J Environ Manage ; 351: 119811, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38157578

RESUMO

Harmful algae blooms (HABs) occur in water bodies throughout the globe and can have multi-faceted impacts on tourism. However, little is known of the magnitude of economic losses to the tourism sector as a result of HABs. There is limited understanding of the empirical relationships between HAB intensity and duration, and the effects of this phenomenon on the tourism sector. This study is based in the state of Florida, USA, a notable sun, sand, and sea destination in the western hemisphere, where blooms of a marine harmful algae are a recurrent threat to coastal tourism. The empirical framework is based on a month and county-level panel database that combines sales by tourism-related businesses with observations from the official HAB surveillance system of the state of Florida. We use time and space fixed-effects regressions to estimate the loss in tourism revenue associated with one additional day of red tide. Results indicate that impacts of HABs on tourism do not follow a linear pattern with increasing HAB concentrations, but rather appear to follow an inverted-U pattern. In other words, higher concentrations of the HAB organism do not necessarily imply higher economic losses, suggesting that the impacts of HABs on tourism are not driven solely by the biophysical element of cell density. Rather, these impacts appear to be mediated and amplified by human dimensions. The loss to tourism-related businesses due to the 2018 Florida red tide bloom was estimated to be $2.7 billion USD, which implies that HABs and their impact on tourism can be considered as a potential 'billion-dollar' disaster.


Assuntos
Proliferação Nociva de Algas , Turismo , Humanos
5.
J Cell Physiol ; 238(7): 1492-1506, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37051890

RESUMO

Low oxygen bone marrow (BM) niches (~1%-4% low O2 ) provide critical signals for hematopoietic stem/progenitor cells (HSC/HSPCs). Our presented data are the first to investigate live, sorted HSC/HSPCs in their native low O2 conditions. Transcriptional and proteomic analysis uncovered differential Ca2+ regulation that correlated with overlapping phenotypic populations consisting of robust increases of cytosolic and mitochondrial Ca2+ , ABC transporter (ABCG2) expression and sodium/hydrogen exchanger (NHE1) expression in live, HSC/HSPCs remaining in constant low O2. We identified a novel Ca2+ high population in HSPCs predominantly detected in low O2 that displayed enhanced frequency of phenotypic LSK/LSKCD150 in low O2 replating assays compared to Ca2+ low populations. Inhibition of the Ca2+ regulator NHE1 (Cariporide) resulted in attenuation of both the low O2 induced Ca2+ high population and subsequent enhanced maintenance of phenotypic LSK and LSKCD150 during low O2 replating. These data reveal multiple levels of differential Ca2+ regulation in low O2 resulting in phenotypic, signaling, and functional consequences in HSC/HSPCs.


Assuntos
Cálcio , Células-Tronco Hematopoéticas , Oxigênio , Medula Óssea/química , Medula Óssea/metabolismo , Cálcio/metabolismo , Células-Tronco Hematopoéticas/metabolismo , Oxigênio/metabolismo , Proteômica , Animais , Camundongos
6.
J Biol Chem ; 293(5): 1551-1567, 2018 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-29196604

RESUMO

Both long-term potentiation (LTP) and depression (LTD) of excitatory synapse strength require the Ca2+/calmodulin (CaM)-dependent protein kinase II (CaMKII) and its autonomous activity generated by Thr-286 autophosphorylation. Additionally, LTP and LTD are correlated with dendritic spine enlargement and shrinkage that are accompanied by the synaptic accumulation or removal, respectively, of the AMPA-receptor regulatory scaffold protein A-kinase anchoring protein (AKAP) 79/150. We show here that the spine shrinkage associated with LTD indeed requires synaptic AKAP79/150 removal, which in turn requires CaMKII activity. In contrast to normal CaMKII substrates, the substrate sites within the AKAP79/150 N-terminal polybasic membrane-cytoskeletal targeting domain were phosphorylated more efficiently by autonomous compared with Ca2+/CaM-stimulated CaMKII activity. This unusual regulation was mediated by Ca2+/CaM binding to the substrate sites resulting in protection from phosphorylation in the presence of Ca2+/CaM, a mechanism that favors phosphorylation by prolonged, weak LTD stimuli versus brief, strong LTP stimuli. Phosphorylation by CaMKII inhibited AKAP79/150 association with F-actin; it also facilitated AKAP79/150 removal from spines but was not required for it. By contrast, LTD-induced spine removal of AKAP79/150 required its depalmitoylation on two Cys residues within the N-terminal targeting domain. Notably, such LTD-induced depalmitoylation was also blocked by CaMKII inhibition. These results provide a mechanism how CaMKII can indeed mediate not only LTP but also LTD through regulated substrate selection; however, in the case of AKAP79/150, indirect CaMKII effects on palmitoylation are more important than the effects of direct phosphorylation. Additionally, our results provide the first direct evidence for a function of the well-described AKAP79/150 trafficking in regulating LTD-induced spine shrinkage.


Assuntos
Proteínas de Ancoragem à Quinase A/metabolismo , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Lipoilação , Potenciação de Longa Duração , Depressão Sináptica de Longo Prazo , Processamento de Proteína Pós-Traducional , Coluna Vertebral/metabolismo , Sinapses/metabolismo , Animais , Humanos , Coluna Vertebral/patologia , Sinapses/patologia
7.
Blood ; 136(19): 2095-2096, 2020 11 05.
Artigo em Inglês | MEDLINE | ID: mdl-33152088

Assuntos
Lisina , Humanos
8.
Proc Natl Acad Sci U S A ; 111(12): 4596-601, 2014 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-24623853

RESUMO

Rett syndrome (RTT) is a severe X-linked neurodevelopmental disorder mainly affecting females and is associated with mutations in MECP2, the gene encoding methyl CpG-binding protein 2. Mouse models suggest that recombinant human insulin-like growth factor 1 (IGF-1) (rhIGF1) (mecasermin) may improve many clinical features. We evaluated the safety, tolerability, and pharmacokinetic profiles of IGF-1 in 12 girls with MECP2 mutations (9 with RTT). In addition, we performed a preliminary assessment of efficacy using automated cardiorespiratory measures, EEG, a set of RTT-oriented clinical assessments, and two standardized behavioral questionnaires. This phase 1 trial included a 4-wk multiple ascending dose (MAD) (40-120 µg/kg twice daily) period and a 20-wk open-label extension (OLE) at the maximum dose. Twelve subjects completed the MAD and 10 the entire study, without evidence of hypoglycemia or serious adverse events. Mecasermin reached the CNS compartment as evidenced by the increase in cerebrospinal fluid IGF-1 levels at the end of the MAD. The drug followed nonlinear kinetics, with greater distribution in the peripheral compartment. Cardiorespiratory measures showed that apnea improved during the OLE. Some neurobehavioral parameters, specifically measures of anxiety and mood also improved during the OLE. These improvements in mood and anxiety scores were supported by reversal of right frontal alpha band asymmetry on EEG, an index of anxiety and depression. Our data indicate that IGF-1 is safe and well tolerated in girls with RTT and, as demonstrated in preclinical studies, ameliorates certain breathing and behavioral abnormalities.


Assuntos
Fator de Crescimento Insulin-Like I/uso terapêutico , Peptídeos e Proteínas de Sinalização Intercelular/uso terapêutico , Síndrome de Rett/tratamento farmacológico , Criança , Pré-Escolar , Feminino , Humanos , Fator de Crescimento Insulin-Like I/efeitos adversos , Fator de Crescimento Insulin-Like I/farmacocinética , Peptídeos e Proteínas de Sinalização Intercelular/efeitos adversos , Peptídeos e Proteínas de Sinalização Intercelular/farmacocinética , Proteínas Recombinantes/efeitos adversos , Proteínas Recombinantes/farmacocinética , Proteínas Recombinantes/uso terapêutico
9.
Neurobiol Dis ; 87: 134-44, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26706598

RESUMO

Neonatal seizures are associated with long term disabilities including epilepsy and cognitive deficits. Using a neonatal seizure rat model that does not develop epilepsy, but develops a phenotype consistent with other models of intellectual disability (ID) and autism spectrum disorders (ASD), we sought to isolate the acute effects of a single episode of early life seizure on hippocampal CA1 synaptic development and plasticity. We have previously shown chronic changes in glutamatergic synapses, loss of long term potentiation (LTP) and enhanced long term depression (LTD), in the adult male rat ~50days following kainic acid (KA) induced early life seizure (KA-ELS) in post-natal (P) 7day old male Sprague-Dawley rats. In the present work, we examined the electrophysiological properties and expression levels of glutamate receptors in the acute period, 2 and 7days, post KA-ELS. Our results show for the first time enhanced LTP 7days after KA-ELS, but no change 2days post KA-ELS. Additionally, we report that ionotropic α-amino-3-hydroxy-5-methyl-isoxazole-propionic acid type glutamate receptor (AMPAR) desensitization is decreased in the same time frame, with no changes in AMPAR expression, phosphorylation, or membrane insertion. Inappropriate enhancement of the synaptic connections in the acute period after the seizure could alter the normal patterning of synaptic development in the hippocampus during this critical period and contribute to learning deficits. Thus, this study demonstrates a novel mechanism by which KA-ELS alters early network properties that potentially lead to adverse outcomes.


Assuntos
Região CA1 Hipocampal/fisiopatologia , Potenciação de Longa Duração/fisiologia , Receptores de AMPA/metabolismo , Convulsões/fisiopatologia , Doença Aguda , Animais , Animais Recém-Nascidos , Western Blotting , Modelos Animais de Doenças , Potenciais Pós-Sinápticos Excitadores/fisiologia , Ácido Caínico , Masculino , Técnicas de Patch-Clamp , Fosforilação/fisiologia , Células Piramidais/fisiologia , Ratos Sprague-Dawley , Receptores de N-Metil-D-Aspartato/metabolismo , Tempo , Técnicas de Cultura de Tecidos
11.
Curr Opin Hematol ; 22(4): 273-8, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26049746

RESUMO

PURPOSE OF REVIEW: Hematopoietic stem (HSCs) and progenitor (HPCs) cells reside in a hypoxic (lowered oxygen tension) environment, in vivo. We review literature on growth of HSCs and HPCs under hypoxic and normoxic (ambient air) conditions with a focus on our recent work demonstrating the detrimental effects of collecting and processing cells in ambient air through a phenomenon termed extra physiologic oxygen shock/stress (EPHOSS), and we describe means to counteract EPHOSS for enhanced collection of HSCs. RECENT FINDINGS: Collection and processing of bone marrow and cord blood cells in ambient air cause rapid differentiation and loss of HSCs, with increases in HPCs. This apparently irreversible EPHOSS phenomenon results from increased mitochondrial reactive oxygen species, mediated by a p53-cyclophilin D-mitochondrial permeability transition pore axis, and involves hypoxia inducing factor-1α and micro-RNA 210. EPHOSS can be mitigated by collecting and processing cells in lowered (3%) oxygen, or in ambient air in the presence of, cyclosporine A which effects the mitochondrial permeability transition pore, resulting in increased HSC collections. SUMMARY: Our recent findings may be advantageous for HSC collection for hematopoietic cell transplantation, and likely for enhanced collection of other stem cell types. EPHOSS should be considered when ex-vivo cell analysis is utilized for personalized medicine, as metabolism of cells and their response to targeted drug treatment ex vivo may not mimic what occurs in vivo.


Assuntos
Coleta de Amostras Sanguíneas/métodos , Células da Medula Óssea/metabolismo , Sangue Fetal/metabolismo , Células-Tronco Hematopoéticas/metabolismo , Hipóxia/metabolismo , Células da Medula Óssea/citologia , Diferenciação Celular , Ciclofilinas/genética , Ciclofilinas/metabolismo , Sangue Fetal/citologia , Regulação da Expressão Gênica , Células-Tronco Hematopoéticas/citologia , Humanos , Hipóxia/genética , Hipóxia/patologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Mitocôndrias/metabolismo , Proteínas de Transporte da Membrana Mitocondrial/genética , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Poro de Transição de Permeabilidade Mitocondrial , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo
12.
Blood ; 122(2): 161-9, 2013 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-23637126

RESUMO

Dipeptidylpeptidase (DPP) 4 has the potential to truncate proteins with a penultimate alanine, proline, or other selective amino acids at the N-terminus. DPP4 truncation of certain chemokines, colony-stimulating factors, and interleukins have recently been linked to regulation of hematopoietic stem/progenitor cells, more mature blood cells, and other cell types. We believe that the potential role of DPP4 in modification of many regulatory proteins, and their subsequent effects on numerous stem/progenitor and other cell-type functions has not been adequately appreciated. This review addresses the potential implications of the modifying effects of DPP4 on a large number of cytokines and other growth-regulating factors with either proven or putative DPP4 truncation sites on hematopoietic cells, and subsequent effects of DPP4-truncated proteins on multiple aspects of steady-state and stressed hematopoiesis, including stem/progenitor cell, and more mature cell, function.


Assuntos
Dipeptidil Peptidase 4/metabolismo , Hematopoese/fisiologia , Células-Tronco Hematopoéticas/metabolismo , Proteínas/metabolismo , Animais , Diferenciação Celular , Linhagem da Célula , Movimento Celular/fisiologia , Células-Tronco Embrionárias/metabolismo , Células-Tronco Hematopoéticas/citologia , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Leucócitos/imunologia , Leucócitos/metabolismo , Células Progenitoras Linfoides/metabolismo , Modelos Biológicos , Células Progenitoras Mieloides/metabolismo
13.
FASEB J ; 28(8): 3810-9, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24843070

RESUMO

A hallmark feature of Ca(2+)/calmodulin (CaM)-dependent protein kinase II (CaMKII) is generation of autonomous (Ca(2+)-independent) activity by T286 autophosphorylation. Biochemical studies have shown that "autonomous" CaMKII is ∼5-fold further stimulated by Ca(2+)/CaM, but demonstration of a physiological function for such regulation within cells has remained elusive. In this study, CaMKII-induced enhancement of synaptic strength in rat hippocampal neurons required both autonomous activity and further stimulation. Synaptic strength was decreased by CaMKIIα knockdown and rescued by reexpression, but not by mutants impaired for autonomy (T286A) or binding to NMDA-type glutamate receptor subunit 2B (GluN2B; formerly NR2B; I205K). Full rescue was seen with constitutively autonomous mutants (T286D), but only if they could be further stimulated (additional T305/306A mutation), and not with two other mutations that additionally impair Ca(2+)/CaM binding. Compared to rescue with wild-type CaMKII, the CaM-binding-impaired mutants even had reduced synaptic strength. One of these mutants (T305/306D) mimicked an inhibitory autophosphorylation of CaMKII, whereas the other one (Δstim) abolished CaM binding without introducing charged residues. Inhibitory T305/306 autophosphorylation also reduced GluN2B binding, but this effect was independent of reduced Ca(2+)/CaM binding and was not mimicked by T305/306D mutation. Thus, even autonomous CaMKII activity must be further stimulated by Ca(2+)/CaM for enhancement of synaptic strength.


Assuntos
Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/fisiologia , Cálcio/fisiologia , Calmodulina/fisiologia , Sinapses/enzimologia , Potenciais de Ação , Animais , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/antagonistas & inibidores , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/genética , Ativação Enzimática , Potenciais Pós-Sinápticos Excitadores/fisiologia , Genes Reporter , Proteínas de Fluorescência Verde/análise , Proteínas de Fluorescência Verde/genética , Hipocampo/citologia , Potenciais Pós-Sinápticos em Miniatura/fisiologia , Mutação de Sentido Incorreto , Neurônios/enzimologia , Neurônios/fisiologia , Fosforilação , Mutação Puntual , Ligação Proteica , Processamento de Proteína Pós-Traducional , Interferência de RNA , RNA Interferente Pequeno/farmacologia , Ratos , Receptores de N-Metil-D-Aspartato/fisiologia , Sinapses/fisiologia
14.
Stem Cells ; 31(8): 1447-53, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23733396

RESUMO

Understanding the factors that regulate hematopoiesis opens up the possibility of modifying these factors and their actions for clinical benefit. DEK, a non-histone nuclear phosphoprotein initially identified as a putative proto-oncogene, has recently been linked to regulate hematopoiesis. DEK has myelosuppressive activity in vitro on proliferation of human and mouse hematopoietic progenitor cells and enhancing activity on engraftment of long-term marrow repopulating mouse stem cells, has been linked in coordinate regulation with the transcription factor C/EBPα, for differentiation of myeloid cells, and apparently targets a long-term repopulating hematopoietic stem cell for leukemic transformation. This review covers the uniqueness of DEK, what is known about how it now functions as a nuclear protein and also as a secreted molecule that can act in paracrine fashion, and how it may be regulated in part by dipeptidylpeptidase 4, an enzyme known to truncate and modify a number of proteins involved in activities on hematopoietic cells. Examples are provided of possible future areas of investigation needed to better understand how DEK may be regulated and function as a regulator of hematopoiesis, information possibly translatable to other normal and diseased immature cell systems.


Assuntos
Proteínas Cromossômicas não Histona/fisiologia , Proteínas de Ligação a DNA/fisiologia , Hematopoese/fisiologia , Células-Tronco Hematopoéticas/fisiologia , Proteínas Oncogênicas/fisiologia , Animais , Humanos , Proteínas de Ligação a Poli-ADP-Ribose , Proto-Oncogene Mas
15.
Curr Opin Hematol ; 20(4): 314-9, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23594692

RESUMO

PURPOSE OF REVIEW: Dipeptidyl peptidase 4 (DPP4, CD26) is a protease that cleaves selected amino acids at the N-terminal penultimate position and has the potential to alter the protein function. The regulation and roles of DPP4 activity are not well understood; therefore, the purpose of this review is to discuss the recent literature regarding DPP4 regulation, as well as the variety of molecules it may affect, and their potential clinical applications. RECENT FINDINGS: Recent insight into the number of proteins that have DPP4 sites, and how DPP4 truncation may alter hematopoiesis based on the protein full length vs. truncated state, has shown that DPP4 truncation of colony-stimulating factors (CSFs) alters their function and that the activity of these CSFs can be enhanced when DPP4 activity is inhibited. DPP4 inhibition has recently been used in a clinical trial to attempt to enhance the engraftment of cord blood cells, and an endogenous DPP4 inhibitor tissue factor pathway inhibitor has been discovered, increasing our understanding of the potential importance of DPP4. SUMMARY: DPP4 plays a role in regulating the activity of CSFs and other cytokines involved in hematopoiesis. This information may be useful for enhancing hematopoietic cell transplantation, blood cell recovery after stress, and for understanding the physiology and pathophysiology of blood and other cell systems.


Assuntos
Dipeptidil Peptidase 4/fisiologia , Hematopoese/fisiologia , Transplante de Células-Tronco Hematopoéticas , Fatores Estimuladores de Colônias/metabolismo , Inibidores da Dipeptidil Peptidase IV , Humanos
16.
Mol Autism ; 15(1): 28, 2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38877552

RESUMO

BACKGROUND: Mutations in the X-linked gene cyclin-dependent kinase-like 5 (CDKL5) cause a severe neurological disorder characterised by early-onset epileptic seizures, autism and intellectual disability (ID). Impaired hippocampal function has been implicated in other models of monogenic forms of autism spectrum disorders and ID and is often linked to epilepsy and behavioural abnormalities. Many individuals with CDKL5 deficiency disorder (CDD) have null mutations and complete loss of CDKL5 protein, therefore in the current study we used a Cdkl5-/y rat model to elucidate the impact of CDKL5 loss on cellular excitability and synaptic function of CA1 pyramidal cells (PCs). We hypothesised abnormal pre and/or post synaptic function and plasticity would be observed in the hippocampus of Cdkl5-/y rats. METHODS: To allow cross-species comparisons of phenotypes associated with the loss of CDKL5, we generated a loss of function mutation in exon 8 of the rat Cdkl5 gene and assessed the impact of the loss of CDLK5 using a combination of extracellular and whole-cell electrophysiological recordings, biochemistry, and histology. RESULTS: Our results indicate that CA1 hippocampal long-term potentiation (LTP) is enhanced in slices prepared from juvenile, but not adult, Cdkl5-/y rats. Enhanced LTP does not result from changes in NMDA receptor function or subunit expression as these remain unaltered throughout development. Furthermore, Ca2+ permeable AMPA receptor mediated currents are unchanged in Cdkl5-/y rats. We observe reduced mEPSC frequency accompanied by increased spine density in basal dendrites of CA1 PCs, however we find no evidence supporting an increase in silent synapses when assessed using a minimal stimulation protocol in slices. Additionally, we found no change in paired-pulse ratio, consistent with normal release probability at Schaffer collateral to CA1 PC synapses. CONCLUSIONS: Our data indicate a role for CDKL5 in hippocampal synaptic function and raise the possibility that altered intracellular signalling rather than synaptic deficits contribute to the altered plasticity. LIMITATIONS: This study has focussed on the electrophysiological and anatomical properties of hippocampal CA1 PCs across early postnatal development. Studies involving other brain regions, older animals and behavioural phenotypes associated with the loss of CDKL5 are needed to understand the pathophysiology of CDD.


Assuntos
Modelos Animais de Doenças , Potenciação de Longa Duração , Proteínas Serina-Treonina Quinases , Receptores de AMPA , Receptores de N-Metil-D-Aspartato , Espasmos Infantis , Animais , Masculino , Ratos , Região CA1 Hipocampal/metabolismo , Região CA1 Hipocampal/patologia , Região CA1 Hipocampal/fisiopatologia , Síndromes Epilépticas/genética , Síndromes Epilépticas/metabolismo , Potenciais Pós-Sinápticos Excitadores , Doenças Genéticas Ligadas ao Cromossomo X/genética , Doenças Genéticas Ligadas ao Cromossomo X/metabolismo , Doenças Genéticas Ligadas ao Cromossomo X/fisiopatologia , Hipocampo/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Serina-Treonina Quinases/genética , Células Piramidais/metabolismo , Células Piramidais/patologia , Receptores de AMPA/metabolismo , Receptores de AMPA/genética , Receptores de N-Metil-D-Aspartato/metabolismo , Receptores de N-Metil-D-Aspartato/genética , Espasmos Infantis/genética , Espasmos Infantis/metabolismo , Sinapses/metabolismo
17.
Neurobiol Dis ; 59: 1-17, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23831253

RESUMO

Outside of Fragile X syndrome (FXS), the role of Fragile-X Mental Retardation Protein (FMRP) in mediating neuropsychological abnormalities is not clear. FMRP, p70-S6 kinase (S6K) and protein phosphatase 2A (PP2A) are thought to cooperate as a dynamic signaling complex. In our prior work, adult rats have enhanced CA1 hippocampal long-term depression (LTD) following an early life seizure (ELS). We now show that mGluR-mediated LTD (mLTD) is specifically enhanced following ELS, similar to FMRP knock-outs. Total FMRP expression is unchanged but S6K is hyperphosphorylated, consistent with S6K overactivation. We postulated that either disruption of the FMRP-S6K-PP2A complex and/or removal of this complex from synapses could explain our findings. Using subcellular fractionation, we were surprised to find that concentrations of FMRP and PP2A were undisturbed in the synaptosomal compartment but reduced in parallel in the cytosolic compartment. Following ELS FMRP phosphorylation was reduced in the cytosolic compartment and increased in the synaptic compartment, in parallel with the compartmentalization of S6K activation. Furthermore, FMRP and PP2A remain bound following ELS. In contrast, the interaction of S6K with FMRP is reduced by ELS. Blockade of PP2A results in enhanced mLTD; this is occluded by ELS. This suggests a critical role for the location and function of the FMRP-S6K-PP2A signaling complex in limiting the amount of mLTD. Specifically, non-synaptic targeting and the function of the complex may influence the "set-point" for regulating mLTD. Consistent with this, striatal-enriched protein tyrosine phosphatase (STEP), an FMRP "target" which regulates mLTD expression, is specifically increased in the synaptosomal compartment following ELS. Further, we provide behavioral data to suggest that FMRP complex dysfunction may underlie altered socialization, a symptom associated and observed in other rodent models of autism, including FXS.


Assuntos
Proteína do X Frágil da Deficiência Intelectual/metabolismo , Depressão Sináptica de Longo Prazo/fisiologia , Receptores de Glutamato Metabotrópico/metabolismo , Convulsões/metabolismo , Convulsões/fisiopatologia , Transdução de Sinais/fisiologia , Animais , Animais Recém-Nascidos , Modelos Animais de Doenças , Inibidores Enzimáticos/farmacologia , Agonistas de Aminoácidos Excitatórios/toxicidade , Feminino , Hipocampo/patologia , Hipocampo/fisiopatologia , Técnicas In Vitro , Ácido Caínico/toxicidade , Depressão Sináptica de Longo Prazo/efeitos dos fármacos , Fosforilação , Gravidez , Proteína Fosfatase 2/metabolismo , Piridinas/farmacologia , Ratos , Ratos Sprague-Dawley , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Convulsões/induzido quimicamente , Transdução de Sinais/efeitos dos fármacos , Frações Subcelulares/metabolismo , Frações Subcelulares/patologia , Tiazóis/farmacologia
18.
Basic Res Cardiol ; 108(5): 370, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23856709

RESUMO

Previous investigations indicate that diminished functional expression of voltage-dependent K(+) (KV) channels impairs control of coronary blood flow in obesity/metabolic syndrome. The goal of this investigation was to test the hypothesis that KV channels are electromechanically coupled to CaV1.2 channels and that coronary microvascular dysfunction in obesity is related to subsequent increases in CaV1.2 channel activity. Initial studies revealed that inhibition of KV channels with 4-aminopyridine (4AP, 0.3 mM) increased intracellular [Ca(2+)], contracted isolated coronary arterioles and decreased coronary reactive hyperemia. These effects were reversed by blockade of CaV1.2 channels. Further studies in chronically instrumented Ossabaw swine showed that inhibition of CaV1.2 channels with nifedipine (10 µg/kg, iv) had no effect on coronary blood flow at rest or during exercise in lean swine. However, inhibition of CaV1.2 channels significantly increased coronary blood flow, conductance, and the balance between coronary flow and metabolism in obese swine (P < 0.05). These changes were associated with a ~50 % increase in inward CaV1.2 current and elevations in expression of the pore-forming subunit (α1c) of CaV1.2 channels in coronary smooth muscle cells from obese swine. Taken together, these findings indicate that electromechanical coupling between KV and CaV1.2 channels is involved in the regulation of coronary vasomotor tone and that increases in CaV1.2 channel activity contribute to coronary microvascular dysfunction in the setting of obesity.


Assuntos
Canais de Cálcio Tipo L/metabolismo , Circulação Coronária/fisiologia , Obesidade/metabolismo , Obesidade/fisiopatologia , Canais de Potássio/metabolismo , Animais , Hemodinâmica/fisiologia , Suínos
19.
PLoS One ; 18(3): e0266351, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36857328

RESUMO

Rett syndrome, a rare genetic neurodevelopmental disorder in humans, does not have an effective cure. However, multiple therapies and medications exist to treat symptoms and improve patients' quality of life. As research continues to discover and evaluate new medications for Rett syndrome patients, there remains a lack of objective physiological and motor activity-based (physio-motor) biomarkers that enable the measurement of the effect of these medications on the change in patients' Rett syndrome severity. In our work, using a commercially available wearable chest patch, we recorded simultaneous electrocardiogram and three-axis acceleration from 20 patients suffering from Rett syndrome along with the corresponding Clinical Global Impression-Severity score, which measures the overall disease severity on a 7-point Likert scale. We derived physio-motor features from these recordings that captured heart rate variability, activity metrics, and the interactions between heart rate and activity. Further, we developed machine learning (ML) models to classify high-severity Rett patients from low-severity Rett patients using the derived physio-motor features. For the best-trained model, we obtained a pooled area under the receiver operating curve equal to 0.92 via a leave-one-out-patient cross-validation approach. Finally, we computed the feature popularity scores for all the trained ML models and identified physio-motor biomarkers for Rett syndrome.


Assuntos
Qualidade de Vida , Síndrome de Rett , Humanos , Frequência Cardíaca , Movimento , Pacientes Ambulatoriais
20.
Cancer Med ; 12(6): 7470-7484, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36683200

RESUMO

BACKGROUND: Cancer is the leading cause of death for Hispanics in the USA. Screening and prevention reduce cancer morbidity and mortality. METHODS: This study administered a cross-sectional web-based survey to self-identified Hispanic residents in the state of Indiana to assess their cancer-related knowledge, beliefs, and behaviors, as well as to identify what factors might be associated with cancer screening and prevention. Chi-square and Fisher's exact test were used to compare associations and logistic regression used to develop both univariate and multivariate regression models. RESULTS: A total of 1520 surveys were completed, median age of respondents was 53, 52% identified as men, 50.9% completed the survey in Spanish, and 60.4% identified the USA as their country of birth. Most were not able to accurately identify ages to begin screening for breast, colorectal, or lung cancer, and there were significant differences in cancer knowledge by education level. US-born individuals with higher income and education more often believed they were likely to develop cancer and worry about getting cancer. Sixty eight percent of respondents were up-to-date with colorectal, 44% with breast, and 61% with cervical cancer screening. Multivariate models showed that higher education, lack of fatalism, older age, lower household income, and unmarried status were associated with cervical cancer screening adherence. CONCLUSIONS: Among a Hispanic population in the state of Indiana, factors associated with cervical cancer screening adherence were similar to the general population, with the exceptions of income and marital status. Younger Hispanic individuals were more likely to be adherent with breast and colorectal cancer screening, and given the higher incidence of cancer among older individuals, these results should guide future research and targeted outreach.


Assuntos
Neoplasias Colorretais , Neoplasias do Colo do Útero , Masculino , Feminino , Humanos , Indiana/epidemiologia , Neoplasias do Colo do Útero/diagnóstico , Detecção Precoce de Câncer , Estudos Transversais , Conhecimentos, Atitudes e Prática em Saúde , Hispânico ou Latino , Programas de Rastreamento
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