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1.
Am J Addict ; 28(6): 431-454, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31513324

RESUMO

BACKGROUND AND OBJECTIVES: Treatment models developed for substance use disorders (SUDs) are often applied to behavioral addictions (BAs), even though the correspondence between these forms of addiction is unclear. This is also the case for noninvasive brain stimulation (NIBS) techniques being investigated as potential treatment interventions for SUDs and BAs. OBJECTIVES: to contribute to the development of more effective NIBS protocols for BAs. METHODS: Two literature searches using PubMed and Google Scholar were conducted identifying a total of 35 studies. The first search identified 25 studies examining the cognitive and neurophysiological overlap between BAs and SUDs. The second search yielded 10 studies examining the effects of NIBS in BAs. RESULTS: Impulsivity and cravings show behavioral and neurophysiologic overlaps between BAs and SUDs, however, other outcomes like working-memory abilities or striatal connectivity, differ between BAs and SUDs. The most-employed NIBS target in BAs was dorsolateral prefrontal cortex (DLPFC), which was associated with a decrease in cravings, and less frequently with a reduction of addiction severity. CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE: Direct comparisons between BAs and SUDs revealed discrepancies between behavioral and neurophysiological outcomes, but overall, common and distinctive characteristics underlying each disorder. The lack of complete overlap between BAs and SUDs suggests that investigating the cognitive and neurophysiological features of BAs to create individual NIBS protocols that target risk-factors associated specifically with BAs, might be more effective than transferring protocols from SUDs to BAs. Individualizing NIBS protocols to target specific risk-factors associated with each BA might help to improve treatment interventions for BAs. (Am J Addict 2019;00:1-23).


Assuntos
Comportamento Aditivo/terapia , Transtornos Relacionados ao Uso de Substâncias/terapia , Estimulação Magnética Transcraniana/métodos , Comportamento Aditivo/psicologia , Fissura , Humanos , Comportamento Impulsivo , Transtornos Relacionados ao Uso de Substâncias/psicologia , Resultado do Tratamento
2.
Addict Behav ; 89: 51-56, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30248548

RESUMO

BACKGROUND AND AIMS: Gambling is an activity that for some can become disordered, with severe negative consequences. Existing literature does little to inform us regarding changing gambling habits of treatment seeking gamblers; the current study sought to measure trends and patterns in UK treatment seeking gambler behaviour and demographics over a 15-year period. METHODS: Case files for 768 gamblers seeking residential treatment with the Gordon Moody Association (GMA) were analysed, collected between 2000 and 2015. Case files comprised initial assessment questionnaires, demographic data, current gambling behaviour, mental and physical health status, and a risk assessment. Chi-squared analyses were used to measure change in categorical distribution. RESULTS: Prevalence of different forms of gambling identified as problematic have changed over time: Fixed Odds Betting Terminals (FOBTs), sports betting, and poker have become more common; horse and dog racing, and the National Lottery have become less common. Online gambling has also increased over time. In more recent years, gamblers are also more likely to have attempted suicide, to report a co-occurring mental health disorder, and to start treatment having already been prescribed medication. DISCUSSION AND CONCLUSIONS: This is the first study to demonstrate that UK treatment seeking gambler behaviour has changed over time; major changes relate to the forms of gambling engaged in problematically, and the mental health of disordered gamblers. Whilst much media focus is directed towards one form of gambling, this should not detract focus from other forms and associated disorders, and the impact of the legislative environment.


Assuntos
Comportamento Aditivo/epidemiologia , Comportamento Aditivo/psicologia , Jogo de Azar/epidemiologia , Jogo de Azar/psicologia , Aceitação pelo Paciente de Cuidados de Saúde/psicologia , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Adolescente , Adulto , Idoso , Comportamento Aditivo/terapia , Feminino , Jogo de Azar/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Inquéritos e Questionários , Reino Unido , Adulto Jovem
3.
Drug Alcohol Depend ; 187: 165-170, 2018 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-29674250

RESUMO

BACKGROUND: Alcohol Use Disorder (AUD) is associated with problems with processing complex social scenarios. Little is known about the relationship between distinct AUD-related factors (e.g., years of problematic drinking), aspects of cognitive function and dysfunction in individuals diagnosed with AUD, and the relative impact these may have on social cognition. AIMS: To explore differences in social cognition between a group of participants diagnosed with AUD and controls, using a clinical measure, the Mini Social and Emotional Assessment (mini-SEA). The mini-SEA was used to evaluate social and emotional understanding through a facial emotional recognition task and by utilising a series of social scenes some of which contain a faux pas (social error). METHODS: Eighty-five participants (individuals with AUD and controls) completed demographic questions and a general cognitive and social cognitive test battery over three consecutive days. RESULTS: Between group analyses revealed that the participants with AUD performed less well on the faux pas test, and differences were also revealed in the emotional facial recognition task. Years of problematic alcohol consumption was the strongest predictor of poor ToM reasoning. CONCLUSION: These results suggest a strong link between AUD chronicity and social cognition, though the direction of this relationship needs further elucidation. This may be of clinical relevance to abstinence and relapse management, as basic social cognition skills and ability to maintain interpersonal relationships are likely to be crucial to recovery.


Assuntos
Alcoolismo/diagnóstico , Alcoolismo/psicologia , Cognição/fisiologia , Emoções/fisiologia , Testes Neuropsicológicos , Comportamento Social , Adulto , Alcoolismo/epidemiologia , Estudos de Coortes , Estudos Transversais , Feminino , Humanos , Relações Interpessoais , Masculino , Pessoa de Meia-Idade , Resolução de Problemas/fisiologia , Adulto Jovem
4.
J Adolesc Health ; 59(6): 612-619, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27693128

RESUMO

Adult electronic cigarette (e-cigarette) use is increasing globally, and early studies have suggested that similar trends may be observed among the adolescent population, albeit at lower levels. The current literature review presents data collected since 2014 from 21 cross-sectional studies and one cohort study that were all published in English. In particular, it focuses on awareness, ever use, past 30-day use, and regular use of e-cigarettes. The article suggests that adolescents are nearing complete awareness of e-cigarettes. Furthermore, in relation to ever use and past 30-day use, higher prevalence rates continue to be reported across time, especially in the United States. Nonetheless, reported regular use of e-cigarettes remains much lower than past 30-day use, although conclusions are limited due to inconsistencies with measurement and consequent lack of cross-cultural applicability. The majority of studies do not report whether adolescents use non-nicotine e-cigarettes. There is a current absence of longitudinal studies that explore any association between e-cigarettes and tobacco use and little qualitative data that may illuminate how and why adolescents use e-cigarettes. Through addressing these methodological limitations, future research will be able to inform health care and policy more effectively.


Assuntos
Comportamento do Adolescente , Sistemas Eletrônicos de Liberação de Nicotina/estatística & dados numéricos , Conhecimentos, Atitudes e Prática em Saúde , Fumar/epidemiologia , Adolescente , Fumar Cigarros/epidemiologia , Estudos Transversais , Humanos , Prevalência , Fumar/psicologia , Abandono do Hábito de Fumar/estatística & dados numéricos , Inquéritos e Questionários
5.
Neurotoxicol Teratol ; 54: 22-8, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26806601

RESUMO

BACKGROUND: Recreational use of 3,4 methylenedioxymethamphetamine (ecstasy, MDMA) is increasing worldwide. Its use by pregnant women causes concern due to potentially harmful effects on the developing fetus. MDMA, an indirect monoaminergic agonist and reuptake inhibitor, affects the serotonin and dopamine systems. Preclinical studies of fetal exposure demonstrate effects on learning, motor behavior, and memory. In the first human studies, we found prenatal MDMA exposure related to poorer motor development in the first year of life. In the present study we assessed the effects of prenatal exposure to MDMA on the trajectory of child development through 2 years of age. We hypothesized that exposure would be associated with poorer mental and motor outcomes. MATERIALS AND METHODS: The DAISY (Drugs and Infancy Study, 2003-2008) employed a prospective longitudinal cohort design to assess recreational drug use during pregnancy and child outcomes in the United Kingdom. Examiners masked to drug exposures followed infants from birth to 4, 12, 18, and 24 months of age. MDMA, cocaine, alcohol, tobacco, cannabis, and other drugs were quantified through a standardized clinical interview. The Bayley Scales (III) of Mental (MDI) and Motor (PDI) Development and the Behavior Rating Scales (BRS) were primary outcome measures. Statistical analyses included a repeated measures mixed model approach controlling for multiple confounders. RESULTS: Participants were pregnant women volunteers, primarily white, of middle class socioeconomic status, average IQ, with some college education, in stable partner relationships. Of 96 women enrolled, children of 93 had at least one follow-up assessment and 81 (87%) had ≥ two assessments. Heavier MDMA exposure (M=1.3±1.4 tablets per week) predicted lower PDI (p<.002), and poorer BRS motor quality from 4 to 24 months of age, but did not affect MDI, orientation, or emotional regulation. Children with heavier exposure were twice as likely to demonstrate poorer motor quality as lighter and non-exposed children (O.R.=2.2, 95%, CI=1.02-4.70, p<.05). DISCUSSION: Infants whose mothers reported heavier MDMA use during pregnancy had motor delays from 4 months to two years of age that were not attributable to other drug or lifestyle factors. Women of child bearing age should be cautioned about the use of MDMA and MDMA-exposed infants should be screened for motor delays and possible intervention.


Assuntos
Deficiências do Desenvolvimento/etiologia , Alucinógenos/efeitos adversos , Transtornos Motores/etiologia , N-Metil-3,4-Metilenodioxianfetamina/efeitos adversos , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Transtornos Psicomotores/etiologia , Pré-Escolar , Feminino , Humanos , Estudos Longitudinais , Masculino , Gravidez , Efeitos Tardios da Exposição Pré-Natal/fisiopatologia , Transtornos Relacionados ao Uso de Substâncias/complicações
6.
Hum Psychopharmacol ; 30(4): 290-4, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26216565

RESUMO

OBJECTIVE: This paper aims to review findings from a longitudinal study of prenatal methylenedioxymethamphetamine (MDMA, "ecstasy") on infant development. METHODS: In a prospective, longitudinal cohort design, we followed 28 MDMA-exposed and 68 non-MDMA-exposed infants from birth to 2 years of age. Women recruited voluntarily into a study of recreational drug use during pregnancy were interviewed to obtain type, frequency, and amount of recreational drug use. Their children were followed for a 2-year period after birth. A large number of drug and environmental covariates were controlled. Infants were seen at 1, 4, 12, 18, and 24 months using standardized normative tests of mental and motor development. RESULTS: There were no differences between MDMA-exposed and non-MDMA-exposed infants at birth except that MDMA-exposed infants were more likely to be male. Motor delays were evident in MDMA infants at each age and amount of MDMA exposure predicted motor deficits at 12 months in a dose-dependent fashion. CONCLUSIONS: Prenatal MDMA exposure is related to fine and gross motor delays in the first 2 years of life. Follow-up studies are needed to determine long-term effects.


Assuntos
Desenvolvimento Infantil/efeitos dos fármacos , Deficiências do Desenvolvimento/etiologia , Alucinógenos/efeitos adversos , N-Metil-3,4-Metilenodioxianfetamina/efeitos adversos , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Efeitos Tardios da Exposição Pré-Natal/fisiopatologia , Adulto , Fatores Etários , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Gravidez , Reino Unido
7.
Hum Psychopharmacol ; 29(1): 1-7, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24424703

RESUMO

OBJECTIVE: The illicit recreational drug 3,4-methylenedioxymethamphetamine (MDMA) or Ecstasy has strong neurohormonal effects. When taken by recreational users at dance clubs and raves, it can generate an 800% increase in the stress hormone cortisol, whereas drug-free users show chronically raised levels of cortisol. The aim here is to critically debate this neurohormonal influence for the children of pregnant MDMA-using mothers. METHODS: High levels of cortisol are known to be damaging for neuropsychobiological well-being in adult humans. MDMA can damage foetal development in laboratory animals, and the prospective Drugs and Infancy Study was established to monitor the effects of MDMA taken recreationally by pregnant women. RESULTS: The Drugs and Infancy Study revealed that young mothers, who took MDMA during the first trimester of pregnancy, gave birth to babies with significant gross psychomotor retardation. These mothers would have experienced high levels of cortisol due to Ecstasy/MDMA use, and since cortisol can cross the placenta, this is likely to have also occurred in the foetus. CONCLUSIONS: In terms of causation, the developmental problems may reflect a combination of neurotransmitter and neurohormonal effects on the hypothalamic-pituitary-adrenal axis, with serotonergic activity being influenced by the high levels of cortisol.


Assuntos
Hidrocortisona/metabolismo , N-Metil-3,4-Metilenodioxianfetamina/toxicidade , Resultado da Gravidez , Animais , Feminino , Desenvolvimento Fetal/efeitos dos fármacos , Alucinógenos/administração & dosagem , Alucinógenos/toxicidade , Humanos , Sistema Hipotálamo-Hipofisário/efeitos dos fármacos , Sistema Hipotálamo-Hipofisário/metabolismo , Drogas Ilícitas/toxicidade , Recém-Nascido , N-Metil-3,4-Metilenodioxianfetamina/administração & dosagem , Sistema Hipófise-Suprarrenal/efeitos dos fármacos , Sistema Hipófise-Suprarrenal/metabolismo , Gravidez , Primeiro Trimestre da Gravidez
8.
J Psychopharmacol ; 28(1): 55-61, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24327452

RESUMO

BACKGROUND: The recreational drug MDMA (3,4-methylenedioxymethamphetamine) or 'Ecstasy' is associated with heightened psychiatric distress and feelings of depression. The Drugs and Infancy Study (DAISY) monitored the psychiatric symptom profiles of mothers who used Ecstasy/MDMA while pregnant, and followed them over the first year post-partum. METHODS: We compared 28 young women whom took MDMA during their pregnancy with a polydrug control group of 68 women who took other psychoactive drugs while pregnant. The Brief Symptom Inventory (BSI) was completed for several periods: The first trimester of pregnancy; and 1, 4 and 12 months after childbirth. Recreational drug use was monitored at each time point. RESULTS: During the first trimester of pregnancy, MDMA-using mothers reported higher depression scores than the polydrug controls. At 1 year after childbirth, their BSI depression scores were significantly lower, now closer to the control group values. At the same time point, their self-reported use of MDMA became nearly zero, in contrast to their continued use of Cannabis/marijuana, nicotine and alcohol. We found significant symptom reductions in those with BSI obsessive-compulsive and interpersonal sensitivity, following Ecstasy/MDMA cessation. CONCLUSIONS: The findings from this unique prospective study of young recreational drug-using mothers are consistent with previous reports of improved psychiatric health after quitting MDMA.


Assuntos
Depressão/induzido quimicamente , Depressão/psicologia , Usuários de Drogas/psicologia , Drogas Ilícitas/efeitos adversos , Mães/psicologia , N-Metil-3,4-Metilenodioxianfetamina/efeitos adversos , Adulto , Estudos de Casos e Controles , Depressão/complicações , Feminino , Nível de Saúde , Humanos , Gravidez , Escalas de Graduação Psiquiátrica , Estresse Psicológico/complicações , Estresse Psicológico/psicologia , Fatores de Tempo , Adulto Jovem
11.
Pediatrics ; 130(3): 407-13, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22908109

RESUMO

OBJECTIVE: A widely used illicit recreational drug among young adults, 3,4-methylenedioxymethamphetamine (MDMA) or ecstasy, is an indirect monoaminergic agonist/reuptake inhibitor affecting the serotonin system. Preclinical studies found prenatal exposure related to long-term learning and memory impairments. There are no studies of sequelae of prenatal MDMA exposure in humans, despite potential harmful effects to the fetus. METHODS: A total of 96 women in the United Kingdom (28 MDMA users; 68 non-MDMA) were interviewed about recreational drug use during pregnancy. Their infants were seen at 12 months using standardized assessments of cognitive, language, and motor development (Preschool Language Scale, Bayley Mental and Motor Development and Behavior Rating Scales [Mental Development Index, Psychomotor Development Index, Behavioral Rating Scale]). Mothers completed the Child Domain Scale of the Parenting Stress Index, The Home Observation of the Environment Scale (in interview), the Brief Symptom Inventory, and the Drug Abuse Screening Test. Women were primarily middle class with some university education, in stable partner relationships, and polydrug users. MDMA and other drug effects were assessed through multiple regression analyses controlling for confounding variables, and analysis of covariance comparing heavier versus lighter and nonexposed groups. RESULTS: Amount of prenatal MDMA exposure predicted poorer infant mental and motor development at 12 months in a dose-dependent manner. Heavily exposed infants were delayed in motor development. Lighter-exposed infants were comparable to nonexposed infants. There were no effects on language, emotional regulation, or parenting stress. CONCLUSIONS: Findings document persistent neurotoxic effects of heavier prenatal MDMA exposure on motor development through the first year of life.


Assuntos
Deficiências do Desenvolvimento/induzido quimicamente , Alucinógenos/efeitos adversos , N-Metil-3,4-Metilenodioxianfetamina/efeitos adversos , Efeitos Tardios da Exposição Pré-Natal , Cognição/efeitos dos fármacos , Deficiências do Desenvolvimento/diagnóstico , Relação Dose-Resposta a Droga , Feminino , Humanos , Lactente , Masculino , Gravidez , Desempenho Psicomotor/efeitos dos fármacos , Fatores Socioeconômicos
12.
Neurotoxicol Teratol ; 34(3): 303-10, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22387807

RESUMO

3,4-methylenedioxymethamphetamine (MDMA) or "Ecstasy" is one of the most widely used illicit recreational drugs among young adults. MDMA is an indirect monoaminergic agonist and reuptake inhibitor that primarily affects the serotonin system. Preclinical studies in animals have found prenatal exposure related to neonatal tremors and long-term learning and memory impairments. To date, there are no prospective studies of the sequelae of prenatal exposure to MDMA in humans, despite concerns about its potential for harmful effects to the fetus. The present study is the first to prospectively identify MDMA-using women during pregnancy and to document patterns and correlates of use with neonatal and early infancy outcomes of offspring. All mothers and infants were prospectively recruited through the Case Western Reserve University (CWRU) and University of East London (UEL) Drugs and Infancy Study (DAISY) that focused on recreational drug use in pregnant women. Women were interviewed about substance use prior to and during pregnancy and infants were seen at 1 and 4 months using standardized, normative assessments of neonatal behavior, and cognitive and motor development, including the NICU Network Neurobehavioral Scale (NNNS), the Bayley Mental and Motor Development Scales (MDI, PDI), and the Alberta Infant Motor Scales (AIMS). The sample was primarily middle class with some university education and in stable partner relationships. The majority of women recruited had taken a number of illicit drugs prior to or during pregnancy. Group differences between those polydrug using women who had specifically used MDMA during pregnancy (n=28) and those who had not (n=68) were assessed using chi-square and t-tests. MDMA and other drug effects were assessed through multiple regression analyses controlling for confounding variables. Women who used MDMA during pregnancy had fewer prior births and more negative sequelae associated with their drug use, including more health, work, and social problems. MDMA exposed infants differed in sex ratio (more male births) and had poorer motor quality and lower milestone attainment at 4 months, with a dose-response relationship to amount of MDMA exposure. These findings suggest risk to the developing infant related to MDMA exposure and warrant continued follow-up to determine whether early motor delays persist or resolve.


Assuntos
Drogas Ilícitas/toxicidade , Comportamento do Lactente/efeitos dos fármacos , N-Metil-3,4-Metilenodioxianfetamina/toxicidade , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Adulto , Feminino , Idade Gestacional , Humanos , Lactente , Comportamento do Lactente/psicologia , Recém-Nascido , Masculino , Testes Neuropsicológicos , Gravidez , Resultado da Gravidez , Efeitos Tardios da Exposição Pré-Natal/psicologia , Estudos Prospectivos
13.
Nucleic Acids Res ; 39(21): e147, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21948795

RESUMO

The ability to verify the sequence of a nucleic acid-based therapeutic is an essential step in the drug development process. The challenge associated with sequence identification increases with the length and nuclease resistance of the nucleic acid molecule, the latter being an important attribute of therapeutic oligonucleotides. We describe methods for the sequence determination of Spiegelmers, which are enantiomers of naturally occurring RNA with high resistance to enzymatic degradation. Spiegelmer sequencing is effected by affixing a label or hapten to the 5'-end of the oligonucleotide and chemically degrading the molecule in a controlled fashion to generate fragments that are then resolved and identified using liquid chromatography-mass spectrometry. The Spiegelmer sequence is then derived from these fragments. Examples are shown for two different Spiegelmers (NOX-E36 and NOX-A12), and the specificity of the method is shown using a NOX-E36 mismatch control.


Assuntos
Cromatografia Líquida , Oligorribonucleotídeos/síntese química , Análise de Sequência de RNA/métodos , Espectrometria de Massas por Ionização por Electrospray , Estereoisomerismo
15.
RNA ; 15(4): 627-36, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19228587

RESUMO

In the last decade short interfering RNA (siRNA) became an important means for functional genomics and the development of gene-specific drugs. However, major technical hurdles in the application of siRNA include its cellular delivery followed by its intracellular trafficking and its release in order to enter the RNA interference (RNAi) machinery. The novel phosphorothioate-stimulated cellular uptake of siRNA contrasts other known delivery systems because it involves a caveosomal pathway in which large amounts of siRNA are delivered to the perinuclear environment, leading to measurable though moderate target suppression. Limited efficacy seems to be related to intracellular trapping of siRNA. To study the role of intracellular trafficking of siRNA for biological effectiveness we studied whether a signal peptide for trans-membrane transport of bacterial protein toxins, which is covalently attached to siRNA, can promote its release from the perinuclear space into the cytoplasm and thereby enhance its biological effectiveness. We show that attachment of the peptide TQIENLKEKG to lamin A/C-directed siRNA improves target inhibition after its PS-stimulated delivery. This is related to increased efflux of the siRNA-peptide conjugate from the ER-specific perinuclear sites. In summary, this study strongly suggests that intracellular release of siRNA leads to increased biological effectiveness. Thus covalent peptide-siRNA conjugates are proposed as new tools to study the relationship between intracellular transport and efficacy of siRNA.


Assuntos
Sinais Direcionadores de Proteínas , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Linhagem Celular Tumoral , Humanos , Laminina/genética , Transporte de RNA
16.
Int J Pharm ; 344(1-2): 96-102, 2007 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-17600642

RESUMO

Synthetic oligonucleotides offer interesting prospects for the control of gene expression but clinical applications have been severely limited by their poor bioavailability. Cationic lipids have been widely used for the delivery of charged oligonucleotide (ON) analogues but most of the commercial formulations are toxic and poorly stable in the presence of serum proteins. We have developed a DOGS/DOPE liposome formulation named DLS (for delivery liposomal system), that allows for the efficient nuclear delivery of negatively charged antisense ON analogues as monitored by fluorescence microscopy and by their ability to correct deficient pre-mRNA splicing, even in serum-supplemented cell culture. Uncharged DNA mimics such as peptide nucleic acids (PNA), or phosphorodiamidate morpholino (PMO) ON are particularly interesting for their high metabolic stability and affinity for complementary RNA targets but they cannot be delivered with cationic lipids. Cell penetrating peptides (CPP), such as Tat or penetratin, have been used widely as conjugates for the delivery of various biomolecules and might be appropriate for neutral ON analogues. However, entrapment within endocytic vesicles severely limits the efficiency of PNA delivery by CPPs in the absence of endosomolytic drugs, such as chloroquine. The conjugation of new arginine-rich CPPs to PNA allows efficient nuclear delivery in the absence of chloroquine as monitored in a splicing correction assay. Both strategies have their advantages but DLS-mediated delivery remains more efficient than CPP delivery for the nuclear targeting of splice correcting ON analogues in vitro.


Assuntos
Oligonucleotídeos Antissenso/administração & dosagem , Oligopeptídeos/química , Ácidos Nucleicos Peptídicos/administração & dosagem , Sistemas de Liberação de Medicamentos , Genes Reporter , Globinas/genética , Células HeLa , Humanos , Íntrons , Lipossomos , Luciferases/genética , Luciferases/metabolismo , Oligonucleotídeos Antissenso/química , Oligopeptídeos/síntese química , Ácidos Nucleicos Peptídicos/química , Ácidos Nucleicos Peptídicos/metabolismo , Splicing de RNA , Transfecção
17.
Nucleic Acids Res ; 35(13): 4495-502, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17584792

RESUMO

Sequence-specific interference with the nuclear pre-mRNA splicing machinery has received increased attention as an analytical tool and for development of therapeutics. It requires sequence-specific and high affinity binding of RNaseH-incompetent DNA mimics to pre-mRNA. Peptide nucleic acids (PNA) or phosphoramidate morpholino oligonucleotides (PMO) are particularly suited as steric block oligonucleotides in this respect. However, splicing correction by PNA or PMO conjugated to cell penetrating peptides (CPP), such as Tat or Penetratin, has required high concentrations (5-10 microM) of such conjugates, unless an endosomolytic agent was added to increase escape from endocytic vesicles. We have focused on the modification of existing CPPs to search for peptides able to deliver more efficiently splice correcting PNA or PMO to the nucleus in the absence of endosomolytic agents. We describe here R6-Penetratin (in which arginine-residues were added to the N-terminus of Penetratin) as the most active of all CPPs tested so far in a splicing correction assay in which masking of a cryptic splice site allows expression of a luciferase reporter gene. Efficient and sequence-specific correction occurs at 1 muM concentration of the R6Pen-PNA705 conjugate as monitored by luciferase luminescence and by RT-PCR. Some aspects of the R6Pen-PNA705 structure-function relationship have also been evaluated.


Assuntos
Proteínas de Transporte/química , Ácidos Nucleicos Peptídicos/metabolismo , Splicing de RNA/efeitos dos fármacos , Transporte Ativo do Núcleo Celular , Arginina/química , Proteínas de Transporte/metabolismo , Núcleo Celular/metabolismo , Cloroquina/farmacologia , Genes Reporter , Células HeLa , Humanos , Ácidos Nucleicos Peptídicos/química , Ácidos Nucleicos Peptídicos/farmacologia
19.
Mol Biosyst ; 3(1): 43-50, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17216055

RESUMO

Synthetic siRNA duplexes are used widely as reagents for silencing of mRNA targets in cells and are being developed for in vivo use. Serum stability is a major concern if siRNA is to be used for therapeutic delivery within blood circulation. We have developed the use of MALDI-TOF mass spectrometry as a rapid and convenient analytical tool to identify the most vulnerable sites within siRNA to serum degradation. Using this approach, we found that one siRNA duplex (Dh3) with UpA sequences close to one end was particularly vulnerable to rapid cleavage. This produced a fragment of mass consistent with the presence of a 2',3'-cyclic phosphate that was slowly hydrolysed to a 2'-(3'-)phosphate on extended incubation. Substitution of these sites with 2'-O-methyl U residues prevented cleavage and confirmed that the major pathway for initial degradation is via cleavage by an RNAse A-like activity. Mass spectral analysis was used to follow the serum degradation of siRNA over more prolonged periods to show the accumulation of many fragments, almost all showing cleavage following pyrimidine nucleoside residues. Overall, the MALDI-TOF mass spectral analysis technique should prove useful for preliminary screening of the serum stability of siRNA duplexes and for identification of the most vulnerable cleavage sites.


Assuntos
Estabilidade de RNA , RNA Interferente Pequeno/química , Ribonucleases/química , Soro/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Sequência de Bases , Dados de Sequência Molecular , Estrutura Molecular , RNA Interferente Pequeno/metabolismo
20.
Blood Cells Mol Dis ; 38(1): 1-7, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17113327

RESUMO

Towards the development of oligonucleotide analogues and siRNA as drugs, one potential alternative to the use of liposomal transfection agents is the covalent conjugation of a cell-penetrating peptide (CPP), with the intention of imparting on the oligonucleotide or siRNA an enhanced ability to enter mammalian cells and reach the appropriate RNA target. We have developed robust methods for the chemical synthesis of disulfide-linked conjugates of oligonucleotide analogues, siRNA and peptide nucleic acids (PNA) with a range of cationic and other CPPs. In a HeLa cell assay with integrated plasmid reporters of Tat-dependent trans-activation at the TAR RNA target in the cell nucleus, we were unable to obtain steric block inhibition of gene expression for conjugates of CPPs with a 12-mer oligonucleotide mixmer of 2'-O-methyl and locked nucleic acids units. By contrast, we were able to obtain some reductions in expression of P38alpha MAP kinase mRNA in HeLa cells using microM concentrations of Penetratin or Tat peptides conjugated to the 3'-end of the sense strand of siRNA. However, the most promising results to date have been with a 16-mer PNA conjugated to the CPP Transportan or a double CPP R(6)-Penetratin, where we have demonstrated Tat-dependent trans-activation inhibition in HeLa cells. Results to date suggest the possibility of development of CPP-PNA conjugates as anti-HIV agents as well as other potential applications involving nuclear cell delivery, such as the redirection of splicing.


Assuntos
Ácidos Nucleicos Peptídicos , Peptídeos , RNA Interferente Pequeno , RNA/metabolismo , Animais , Humanos
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