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1.
Epigenetics ; 18(1): 2231722, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37433036

RESUMO

Pregnancy can exacerbate or prompt the onset of stress-related disorders, such as post-traumatic stress disorder (PTSD). PTSD is associated with heightened stress responsivity and emotional dysregulation, as well as increased risk of chronic disorders and mortality. Further, maternal PTSD is associated with gestational epigenetic age acceleration in newborns, implicating the prenatal period as a developmental time period for the transmission of effects across generations. Here, we evaluated the associations between PTSD symptoms, maternal epigenetic age acceleration, and infant gestational epigenetic age acceleration in 89 maternal-neonatal dyads. Trauma-related experiences and PTSD symptoms in mothers were assessed during the third trimester of pregnancy. The MethylationEPIC array was used to generate DNA methylation data from maternal and neonatal saliva samples collected within 24 h of infant birth. Maternal epigenetic age acceleration was calculated using Horvath's multi-tissue clock, PhenoAge and GrimAge. Gestational epigenetic age was estimated using the Haftorn clock. Maternal cumulative past-year stress (GrimAge: p = 3.23e-04, PhenoAge: p = 9.92e-03), PTSD symptoms (GrimAge: p = 0.019), and difficulties in emotion regulation (GrimAge: p = 0.028) were associated with accelerated epigenetic age in mothers. Maternal PTSD symptoms were associated with lower gestational epigenetic age acceleration in neonates (p = 0.032). Overall, our results suggest that maternal cumulative past-year stress exposure and trauma-related symptoms may increase the risk for age-related problems in mothers and developmental problems in their newborns.


Assuntos
Envelhecimento , Metilação de DNA , Epigênese Genética , Transtornos de Estresse Pós-Traumáticos , Feminino , Humanos , Recém-Nascido , Gravidez , Aceleração , Emoções , Hispânico ou Latino/genética , Hispânico ou Latino/psicologia , Mães , Transtornos de Estresse Pós-Traumáticos/genética
2.
Exp Neurol ; 329: 113308, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32289314

RESUMO

Stroke remains a leading cause of disability in the United States. Despite recent advances, interventions to reduce damage and enhance recovery after stroke are lacking. P2X4R, a receptor for adenosine triphosphate (ATP), regulates activation of myeloid immune cells (infiltrating monocytes/macrophages and brain-resident microglia) after stroke injury. However, over-stimulation of P2X4Rs due to excessive ATP release from dying or damaged neuronal cells can contribute to ischemic injury. Therefore, we pharmacologically inhibited P2X4R to limit the over-stimulated myeloid cell immune response and improve both acute and chronic stroke recovery. We subjected 8-12-week-old male and female wild type mice to a 60 min right middle cerebral artery occlusion (MCAo) followed by 3 or 30 days of reperfusion. We performed histological, RNA sequencing, behavioral (sensorimotor, anxiety, and depressive), and biochemical (Evans blue dye extravasation, western blot, quantitative PCR, and flow cytometry) analyses to determine the acute (3 days after MCAo) and chronic (30 days after MCAo) effects of P2X4R antagonist 5-BDBD (1 mg/kg P.O. daily x 3 days post 4 h of MCAo) treatment. 5-BDBD treatment significantly (p < .05) reduced infarct volume, neurological deficit (ND) score, levels of cytokine interleukin-1 beta (IL-1ß) and blood brain barrier (BBB) permeability in the 3-day group. Chronically, 5-BDBD treatment also conferred progressive recovery (p < .05) of motor balance and coordination using a rotarod test, as well as reduced anxiety-like behavior over 30 days. Interestingly, depressive-type behavior was not observed in mice treated with 5-BDBD for 3 days. In addition, flow cytometric analysis revealed that 5-BDBD treatment decreased the total number of infiltrated leukocytes, and among those infiltrated leukocytes, pro-inflammatory cells of myeloid origin were specifically reduced. 5-BDBD treatment reduced the cell surface expression of P2X4R in flow cytometry-sorted monocytes and microglia without reducing the total P2X4R level in brain tissue. In summary, acute P2X4R inhibition protects against ischemic injury at both acute and chronic time-points after stroke. Reduced numbers of infiltrating pro-inflammatory myeloid cells, decreased surface P2X4R expression, and reduced BBB disruption are likely its mechanism of neuroprotection and neuro-rehabilitation.


Assuntos
Benzodiazepinonas/uso terapêutico , AVC Isquêmico/metabolismo , AVC Isquêmico/prevenção & controle , Neuroproteção/fisiologia , Fármacos Neuroprotetores/uso terapêutico , Antagonistas do Receptor Purinérgico P2X/uso terapêutico , Animais , Benzodiazepinonas/farmacologia , Relação Dose-Resposta a Droga , Feminino , Células HEK293 , Humanos , AVC Isquêmico/reabilitação , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neuroproteção/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Antagonistas do Receptor Purinérgico P2X/farmacologia , Receptores Purinérgicos P2X4/metabolismo
3.
Psychoneuroendocrinology ; 114: 104604, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32109789

RESUMO

BACKGROUND: Genetic variation and epigenetic mechanisms involving the stress-related gene FKBP5 have been implicated in the intergenerational transmission of trauma-related effects in adult offspring of trauma-exposed caregivers, but these processes have not been fully explored in postpartum women and their newborn infants. METHODS: Women recruited from a prenatal care clinic during their third trimester of pregnancy (N = 114) completed a battery of instruments assessing adverse childhood experiences (ACEs), adversity in adulthood, posttraumatic stress disorder (PTSD) symptoms, negative emotional state, and emotion dysregulation. FKBP5 rs1360780 genotype and intron 7 methylation were derived from saliva collected from postpartum mothers and their newborn infants within 24 h of delivery. RESULTS: Allele-specific associations of methylation with maternal ACEs and prenatal trauma-related symptoms were evident; however, relations differed between mothers and newborns. In mothers carrying the stress sensitive T-allele (CT and TT genotypes), maternal FKBP5 methylation negatively correlated with threat-based ACEs and maternal PTSD symptoms during pregnancy, but not deprivation-based ACEs. In infants homozygous for the C allele (CC genotype), infant FKBP5 methylation positively correlated with maternal threat-based ACEs and prenatal PTSD symptom severity, but not deprivation-based ACEs or adversity in adulthood. CONCLUSIONS: Our results provide evidence that links maternal threat-based ACEs and trauma-related symptoms during pregnancy with allele-specific epigenetic patterns in postpartum women and their newborn infants. These findings provide mechanistic insight into the potential intergenerational impact of ACEs and the effect of maternal PTSD symptoms during pregnancy.


Assuntos
Experiências Adversas da Infância , Período Pós-Parto/genética , Complicações na Gravidez/fisiopatologia , Trauma Psicológico/fisiopatologia , Transtornos de Estresse Pós-Traumáticos/fisiopatologia , Proteínas de Ligação a Tacrolimo/genética , Adolescente , Adulto , Metilação de DNA/genética , Epigênese Genética/genética , Feminino , Seguimentos , Humanos , Recém-Nascido , Gravidez , Índice de Gravidade de Doença , Adulto Jovem
4.
Neurosci Lett ; 715: 134610, 2020 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-31722236

RESUMO

Dysregulation of microRNAs (miRNAs) has been tied to several neurological disorders, including ischemic stroke. It has also been established that social environments can modulate miRNA profiles. We have previously shown that post-stroke social isolation (SI) is linked to poor stroke outcomes and that miR-181c-5p emerged as one of few lead miRNAs that was downregulated in both stroke and SI. Therefore, in this study we examined the potential role of miR-181c-5p mimic in reversing the detrimental effects of post-stroke SI. Two to three-month-old C57BL/6 male mice were pair-housed (PH) for at least two weeks. After two weeks, mice underwent stroke survival surgery using middle cerebral artery occlusion (MCAO) and were randomly assigned to one of two housing conditions: stroke isolation (ST-ISO) or stroke pair-housing with a healthy partner (ST-PH). ST-ISO mice were randomized to receive either miR-181c-5p mimic or a scrambled RNA (7 mg/kg i.v./day×drug) control at 24 h and 48 h after stroke. The effects of miR-181c-5p mimic treatment were evaluated at 1, 3, and 7 days after stroke at histological, behavioral, and biochemical levels. Target genes of miR-181c-5p were then analyzed by qPCR using an RT2 Profiler qPCR Array of pre-coated miR-181c gene targets. Temporal profile expression data suggested that miR-181c-5p was significantly downregulated (p < 0.05 vs ST-PH) up to 7 days after post-stroke SI. MiR-181c-5p mimic treatment significantly increased miR-181c-5p expression in brain tissue and showed partial swift recovery in sensorimotor deficit. Target gene analysis identified downregulation of several calcium signaling-related genes, e.g., Cpne2 and Gria 1 & 2 after miR-181c-5p mimic treatment. In summary, present data suggests that miR-181c-5p is a potential target for post-stroke SI. Data also suggests that genes related to calcium and glutamate signaling might be involved in the beneficial effect of the miR-181c-5p mimic.


Assuntos
Encéfalo/metabolismo , MicroRNAs/biossíntese , Recuperação de Função Fisiológica/fisiologia , Isolamento Social , Acidente Vascular Cerebral/metabolismo , Animais , Camundongos , Camundongos Endogâmicos C57BL , MicroRNAs/genética , Distribuição Aleatória , Isolamento Social/psicologia , Acidente Vascular Cerebral/genética , Acidente Vascular Cerebral/psicologia
5.
J Child Adolesc Psychopharmacol ; 27(10): 875-883, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28829159

RESUMO

OBJECTIVE: To assess patient characteristics and clinician-rated outcomes for children diagnosed with early-onset bipolar disorder in comparison to a depressive disorders cohort from a single clinic site. To assess predictors of bipolar treatment response. METHODS: Medical records from 714 consecutive pediatric patients evaluated and treated at an academic tertiary child and adolescent psychiatry clinic between 2006 and 2012 were reviewed. Charts of bipolar children (n = 49) and children with depressive disorders (n = 58) meeting study inclusion/exclusion criteria were compared on variables assessing clinical characteristics, treatments, and outcomes. Outcomes were assessed by using pre- and post-Clinical Global Impressions (CGI)-Severity and Children's Global Assessment Scale (CGAS) scores, and a CGI-Improvement score ≤2 at final visit determined responder status. Bipolar outcome predictors were assessed by using multiple linear regression. RESULTS: Clinic prevalence rates were 6.9% for early-onset bipolar disorder and 1.5% for very early-onset bipolar disorder. High rates of comorbid diagnoses, symptom severity, parental stress, and child high-risk behaviors were found in both groups. The bipolar cohort had higher rates of aggression and higher lifetime systems of care utilization. The final CGI and CGAS outcomes for unipolar depression patients differed statistically significantly from those for the bipolar cohort, reflecting better clinical status and more improvement at outcome for the depression patients. Both parent-reported Child Behavior Checklist total T-score at clinic admission and the number of lifetime systems-of-care for the child were significantly and inversely associated with improvement for the bipolar cohort. CONCLUSIONS: Early-onset bipolar disorder is a complex and heterogeneous psychiatric disorder. Evidence-based treatment should emphasize psychopharmacology with adjunctive family and individual psychotherapy. Strategies to improve engagement in treatment may be especially important. Given high rates of high-risk behaviors in these youth, regular mental health follow-up to assess safety is important. Additional evidence-based treatments for pediatric bipolar disorder are needed.


Assuntos
Centros Médicos Acadêmicos , Transtorno Bipolar/diagnóstico , Transtorno Bipolar/terapia , Ambulatório Hospitalar , Centros Médicos Acadêmicos/estatística & dados numéricos , Adolescente , Idade de Início , Transtorno Bipolar/psicologia , Criança , Feminino , Humanos , Masculino , Ambulatório Hospitalar/estatística & dados numéricos , Escalas de Graduação Psiquiátrica , Psicoterapia/métodos , Resultado do Tratamento
7.
Exp Neurol ; 249: 120-31, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23994069

RESUMO

Aging and biological sex are critical determinants of stroke outcome. Post-ischemic inflammatory response strongly contributes to the extent of ischemic brain injury, but how this response changes with age and sex is unknown. We subjected young (5-6 months), middle aged (14-15 months) and aged (20-22 months), C57BL/6 male and female mice to transient middle cerebral artery occlusion (MCAO) and found that a significant age by sex interaction influenced histological stroke outcomes. Acute functional outcomes were worse with aging. Neutrophils, inflammatory macrophages, macrophages, dendritic cells (DCs) and microglia significantly increased in the brain post MCAO. Cycling females had higher Gr1(-) non-inflammatory macrophages and lower T cells in the brain after stroke and these correlated with serum estradiol levels. Estrogen loss in acyclic aged female mice exacerbated stroke induced splenic contraction. Advanced age increased T cells, DCs and microglia at the site of injury, which may be responsible for the exacerbated behavioral deficits in the aged. We conclude that aging and sex have differential effects on the post stroke inflammatory milieu. Putative immunomodulatory therapies need to account for this heterogeneity.


Assuntos
Envelhecimento/patologia , Envelhecimento/fisiologia , Isquemia Encefálica/patologia , Isquemia Encefálica/fisiopatologia , Longevidade/fisiologia , Caracteres Sexuais , Acidente Vascular Cerebral/patologia , Acidente Vascular Cerebral/fisiopatologia , Envelhecimento/metabolismo , Animais , Isquemia Encefálica/metabolismo , Feminino , Inflamação/metabolismo , Inflamação/patologia , Inflamação/fisiopatologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Distribuição Aleatória , Acidente Vascular Cerebral/metabolismo
8.
Reprod Biomed Online ; 25(2): 204-8, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22683149

RESUMO

Multiple gestations resulting from IVF continue to be a major problem associated with maternal/neonatal morbidity and mortality including preterm labour/delivery, pre-eclampsia and post-partum haemorrhage. A prospective survey at a university IVF clinic evaluated the effect of education and insurance coverage on patients' preferences for single-embryo transfer (SET) versus double-embryo transfer (DET). Patients undergoing IVF treatment from September 2008 to October 2009 were included. The main outcome measure was patients' preference of SET versus DET. Patients were sent an educational handout describing maternal and fetal risks of twin gestation. A total of 163 patients (32.6% response rate) returned the pre- and post-education surveys regarding preferences for SET versus DET based on three different IVF insurance coverage scenarios (no coverage, two cycles covered and unlimited coverage). There were statistically significant differences in the preference for SET before and after education across all insurance scenarios (scenario 1, 42.0% versus 61.1%; scenario 2, 50.6% versus 71.0%; and scenario 3, 61.7% versus 79.6%; P<0.001 for all scenarios). Before education, patients preferred SET more in the unlimited coverage scenario (61.7%) versus no coverage (42.0%; P<0.001). An educational handout and increasing the amount of insurance coverage significantly increased a patient's preference for SET.


Assuntos
Benefícios do Seguro/economia , Educação de Pacientes como Assunto/métodos , Preferência do Paciente/psicologia , Transferência de Embrião Único/economia , Transferência de Embrião Único/métodos , Adulto , Connecticut , Feminino , Humanos , Preferência do Paciente/economia , Estudos Prospectivos
9.
Fertil Steril ; 97(3): 572-8, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22245528

RESUMO

OBJECTIVE: To determine the relationship between progesterone receptor membrane component-1 (PGRMC1) expression and the outcome of IVF treatment. DESIGN: A prospective study in which PGRMC1 messenger RNA (mRNA) levels, methylation status of the Pgrmc1 promoter, and the presence of point mutations within Pgrmc1 were obtained from granulosa (GC)/luteal cells of women undergoing controlled ovarian hyperstimulation (COH). SETTING: Fertility center/basic science laboratory. PATIENT(S): Eighty-five patients undergoing IVF treatment and 10 women who were undergoing COH for the purpose of oocyte donation were included in this study. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): The PGRMC1 measurements were correlated with clinical outcomes, such as number of follicles, number of retrieved oocytes, and ongoing pregnancy rates (PR). RESULT(S): The PGRMC1 mRNA levels within GC/luteal cells of 18% of IVF patients were >2.25-fold higher than those of oocyte donors. Individuals with elevated PGRMC1 mRNA levels had 30% fewer large follicles and fewer oocytes retrieved. The elevated PGRMC1 mRNA levels were associated with an increase in the methylation of Pgrmc1 promoter. CONCLUSION(S): In patients with elevated PGRMC1 mRNA levels, gonadotropin-induced follicle development is attenuated, although sufficient numbers of follicles develop to allow for ET and subsequent pregnancy.


Assuntos
Fertilização in vitro , Infertilidade/terapia , Células Lúteas/metabolismo , Proteínas de Membrana/genética , Receptores de Progesterona/genética , Adulto , Connecticut , Metilação de DNA , Transferência Embrionária , Éxons , Feminino , Fármacos para a Fertilidade Feminina/administração & dosagem , Humanos , Infertilidade/genética , Infertilidade/metabolismo , Células Lúteas/efeitos dos fármacos , Proteínas de Membrana/metabolismo , Recuperação de Oócitos , Indução da Ovulação , Mutação Puntual , Gravidez , Taxa de Gravidez , Regiões Promotoras Genéticas , Estudos Prospectivos , RNA Mensageiro/metabolismo , Receptores de Progesterona/metabolismo , Resultado do Tratamento , Regulação para Cima
10.
Dev Dyn ; 240(5): 1289-302, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21465622

RESUMO

Sonic hedgehog (Shh) signaling in the limb plays a central role in coordination of limb patterning and outgrowth. Shh expression in the limb is limited to the cells of the zone of polarizing activity (ZPA), located in posterior limb bud mesoderm. Shh is not expressed by limb ectoderm or apical ectodermal ridge (AER), but recent studies suggest a role for AER-Shh signaling in limb patterning. Here, we have examined the effects of activation of Shh signaling in the AER. We find that targeted expression of Shh in the AER activates constitutive Shh signaling throughout the AER and subjacent limb mesoderm, and causes a range of limb patterning defects with progressive severity from mild polydactyly, to polysyndactyly with proximal defects, to severe oligodactyly with phocomelia and partial limb ventralization. Our studies emphasize the importance of control of the timing, level and location of Shh pathway signaling for limb anterior-posterior, proximal-distal, and dorsal-ventral patterning.


Assuntos
Extremidades/embriologia , Proteínas Hedgehog/metabolismo , Botões de Extremidades/metabolismo , Animais , Ectoderma/embriologia , Ectoderma/metabolismo , Proteínas Hedgehog/genética , Botões de Extremidades/embriologia , Camundongos , Camundongos Transgênicos , Transdução de Sinais/genética , Transdução de Sinais/fisiologia
11.
Methods Mol Biol ; 475: 347-61, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18979254

RESUMO

Cell fusion would seem to be obviously recognizable upon visual inspection, and many studies employ a simple microscopic fusion index to quantify the rate and extent of fusion in cell culture. However, when cells are not in monolayers or when there is a large background of multinucleation through failed cytokinesis, cell-cell fusion can only be proven by mixing of cell contents. Furthermore, determination of the microscopic fusion index must generally be carried out manually, creating opportunities for unintended observer bias and limiting the numbers of cells assayed and therefore the statistical power of the assay. Strategies for making assays dependent on fusion and independent of visual observation are critical to increasing the accuracy and throughput of screens for molecules that control cell fusion. A variety of in vitro biochemical and nonbiochemical techniques have been developed to assay and monitor fusion events in cultured cells. In this chapter, we briefly discuss several in vitro fusion assays, nearly all based on systems of two components that interact to create a novel assayable signal only after cells fuse. We provide details for the use of one example of such a system, intracistronic complementation of beta-galactosidase activity by mutants of Escherichia coli lacZ, which allows for either cell-by-cell microscopic assay of cell fusion or quantitative and kinetic detection of cell fusions in whole populations. In addition, we describe a combination of gene knock-down protocols with this assay to study factors required for myoblast fusion.


Assuntos
Bioensaio/métodos , Fusão Celular/métodos , Animais , Células Cultivadas , Fluorescência , Transferência Ressonante de Energia de Fluorescência , Hemaglutininas/metabolismo , Integrases/metabolismo , Medições Luminescentes , Camundongos , Peptídeos/metabolismo , RNA Interferente Pequeno/metabolismo , Temperatura , beta-Galactosidase/metabolismo
12.
J Biomed Opt ; 13(4): 044018, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-19021346

RESUMO

Determining the health of muscle cells by in vivo imaging could impact the diagnosis and monitoring of a large number of congenital and acquired muscular or cardiac disorders. However, currently used technologies are hampered by insufficient resolution, lack of specificity, or invasiveness. We have combined intrinsic optical second-harmonic generation from sarcomeric myosin with a novel mathematical treatment of striation pattern analysis, to obtain measures of muscle contractile integrity that correlate strongly with the neuromuscular health of mice suffering from genetic, acquired, and age-related decline in skeletal muscle function. Analysis of biopsies from a pilot group of human volunteers suggests a similar power in quantifying sarcopenic changes in muscle integrity. These results provide the first strong evidence that quantitative image analysis of sarcomere pattern can be correlated with physiological function, and they invite the application of SHG imaging in clinical practice, either in biopsy samples or via microendoscopy.


Assuntos
Algoritmos , Inteligência Artificial , Interpretação de Imagem Assistida por Computador/métodos , Microscopia/métodos , Doenças Musculares/patologia , Reconhecimento Automatizado de Padrão/métodos , Sarcômeros/patologia , Animais , Humanos , Aumento da Imagem/métodos , Camundongos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Índice de Gravidade de Doença
13.
J Biomed Mater Res A ; 83(1): 64-9, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17380499

RESUMO

Pyrolytic carbon (PYC) containing approximately 7 wt % silicon is used in most clinical mechanical heart valves where it has demonstrated a high level of blood compatibility. The Si, present as SiC, is included since it is believed to enhance durability. However, it has been suggested that SiC reduces PYC blood compatibility. In the present study, PYC valve leaflets were prepared with low, conventional, and high levels of Si. The in vitro responses of human platelets to these materials were then quantified. Platelet responses were consistent with previous reports: Adherent platelets were extremely well spread, closely followed submicron contours, and formed very few aggregates or microthrombi-like structures. No significant differences with respect to the Si concentrations were observed for platelets adherent per unit area and the numbers of thrombi-like structures. Some differences were observed with platelet morphologies and the material surface covered with platelets, although these did not vary consistently with respect to Si concentration. These results indicate that lowering (or raising) the Si alloy concentration in PYC over a reasonable range (0.54-13.5 wt % as examined here) is unlikely to improve or otherwise alter the in vivo blood compatibility of this important clinical material.


Assuntos
Ligas/farmacologia , Plaquetas/efeitos dos fármacos , Carbono/farmacologia , Silício/farmacologia , Adulto , Plaquetas/citologia , Humanos , Adesividade Plaquetária/efeitos dos fármacos
14.
Curr Biol ; 15(5): 413-23, 2005 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-15753035

RESUMO

BACKGROUND: Many animal tissues form via fusion of cells. Yet in all instances of developmental cell fusion, the mechanism underlying fusion of plasma membranes remains poorly understood. EFF-1 is required for most somatic cell fusions in C. elegans, and misexpressed EFF-1 alters the normal pattern of fusing hypodermal cells. However, the autonomous activity of EFF-1, the rules governing its specificity, and the mechanism of its action have not been examined. RESULTS: We show that EFF-1 acts as a cellular fusogen, capable of inducing fusion of virtually any somatic cells in C. elegans, yet targeted precisely to fusion-fated contacts during normal development. Misexpression of EFF-1 in early embryos causes fusion among groups of cells composed entirely of nonfusion-fated members. Measurements of cytoplasm diffusion in induced fusion events show that ectopic EFF-1 expression produces fusion pores similar to those in normal fusion events. GFP-labeled EFF-1 is specifically targeted to fusion-competent cell contacts via reciprocal localization to the touching membranes of EFF-1-expressing cells. EFF-1 function is also governed by intercellular barriers that prohibit cell fusion between distinct tissues. Analysis of mutant versions of EFF-1 indicates a novel mode of fusogenicity, employing neither a phospholipase active site nor hydrophobic fusion-peptide acting solely in pore formation. CONCLUSIONS: EFF-1 can confer potent fusogenic activity to nonfusing cell types. However, it is normally targeted only to fusion-fated cell borders via mutual interaction between EFF-1-expressing cells and relocalization to the plasma membrane. Because EFF-1 appears evolutionarily unique to nematodes, multiple mechanisms may have evolved for controlled plasma-membrane fusion in development.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/embriologia , Membrana Celular/fisiologia , Regulação da Expressão Gênica no Desenvolvimento , Glicoproteínas de Membrana/metabolismo , Modelos Biológicos , Motivos de Aminoácidos/fisiologia , Animais , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Adesão Celular/fisiologia , Membrana Celular/metabolismo , Permeabilidade da Membrana Celular/fisiologia , Biologia Computacional , Primers do DNA , Componentes do Gene , Proteínas de Fluorescência Verde , Glicoproteínas de Membrana/genética , Mutagênese Sítio-Dirigida , Mutação/genética , Plasmídeos/genética , Transgenes/genética
15.
Dev Cell ; 4(4): 587-98, 2003 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12689596

RESUMO

Engulfment of apoptotic cells requires presentation of new cell surface ligands by the dying cells. Using a differential proteomics technology, we identify that annexin I is a caspase-dependent engulfment ligand; it is recruited from the cytosol and exported to the outer plasma membrane leaflet, colocalizes with phosphatidylserine, and is required for efficient clearance of apoptotic cells. Furthermore, phosphatidylserine receptor (PSR) clustering around apoptotic cells indicates a requirement for annexin I. In the nematode Caenorhabditis elegans, downregulation of the annexin homolog prevents efficient engulfment of pharyngeal cell corpses. These results provide novel mechanistic insights into how apoptotic cells are removed and may explain a pathogenic mechanism of chronic inflammatory diseases where annexin I autoantibodies have been described.


Assuntos
Anexina A1/metabolismo , Apoptose/fisiologia , Proteínas de Caenorhabditis elegans , Caenorhabditis elegans/metabolismo , Membrana Celular/metabolismo , Células Eucarióticas/metabolismo , Fagocitose/fisiologia , Receptores de Superfície Celular/metabolismo , Animais , Anexinas/metabolismo , Caenorhabditis elegans/citologia , Sinalização do Cálcio/fisiologia , Caspases/metabolismo , Estruturas da Membrana Celular/metabolismo , Regulação para Baixo/fisiologia , Células Eucarióticas/citologia , Proteínas de Helminto/metabolismo , Humanos , Histona Desmetilases com o Domínio Jumonji , Células Jurkat , Ligantes , Proteínas de Membrana/metabolismo , Fragmentos de Peptídeos/metabolismo , Transporte Proteico/fisiologia , Transdução de Sinais/fisiologia , Regulação para Cima/fisiologia
16.
Dev Cell ; 2(3): 355-62, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11879640

RESUMO

Multinucleate cells are widespread in nature, yet the mechanism by which cells fuse their plasma membranes is poorly understood. To identify animal fusogens, we performed new screens for mutations that abolish cell fusion within tissues of C. elegans throughout development. We identified the gene eff-1, which is expressed as cells acquire fusion competence and encodes a novel integral membrane protein. EFF-1 sequence motifs suggest physicochemical actions that could cause adjacent bilayers to fuse. Mutations in the extracellular domain of EFF-1 completely block epithelial cell membrane fusion without affecting other perfusion events such as cell generation, patterning, differentiation, and adhesion. Thus, EFF-1 is a key component in the mechanism of cell fusion, a process essential to normal animal development.


Assuntos
Caenorhabditis elegans/fisiologia , Fusão Celular , Proteínas de Helminto/metabolismo , Fusão de Membrana/fisiologia , Animais , Animais Geneticamente Modificados , Caenorhabditis elegans/crescimento & desenvolvimento , Células Epidérmicas , Epiderme/crescimento & desenvolvimento , Células Epiteliais/citologia , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Glicoproteínas/genética , Glicoproteínas/metabolismo , Proteínas de Helminto/genética , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Dados de Sequência Molecular , Mutação/fisiologia , Fenótipo , Vulva/citologia , Vulva/crescimento & desenvolvimento
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