RESUMO
OBJECTIVE: To determine whether pharmacologic treatment for neonatal abstinence syndrome (NAS) is associated with changes in DNA methylation (DNAm) of the mu-opioid receptor gene (OPRM1) and improvements in neonatal neurobehavior. STUDY DESIGN: Buccal swabs were collected from 37 neonates before and after morphine treatment for NAS. Genomic DNA was extracted, and DNAm was examined at 4 cytosine-phosphate-guanine (CpG) sites within the OPRM1 gene. Assessment with the NICU Network Neurobehavioral Scales (NNNS) was also performed before and after NAS treatment. Changes in DNAm (DNAmpost-tx - DNAmpre-tx) and NNNS summary scores (NNNSpost-tx - NNNSpre-tx) were then calculated. Path analysis was used to examine associations among pharmacologic treatment (length of treatment [LOT] and total dose of morphine), changes in DNAm, and changes in NNNS summary scores. RESULTS: DNAm was significantly decreased from pretreatment to post-treatment at 1 of 4 CpG sites within the OPRM1 gene. Neonates also demonstrated decreased excitability, hypertonia, lethargy, signs of stress and abstinence, and increased quality of movement and regulation from pretreatment to post-treatment. Longer LOT and higher morphine dose were associated with greater decreases in DNAm; greater decreases in DNAm were associated with greater decreases in excitability and hypertonia on the NNNS. CONCLUSIONS: Pharmacologic treatment of NAS is associated with decreased DNAm of the OPRM1 gene and improved neonatal neurobehavior. Epigenetic changes may play a role in these changes in neonatal neurobehavior.
Assuntos
Síndrome de Abstinência Neonatal , Metilação de DNA , Humanos , Recém-Nascido , Morfina/uso terapêutico , Hipertonia Muscular/tratamento farmacológico , Hipertonia Muscular/genética , Síndrome de Abstinência Neonatal/diagnóstico , Síndrome de Abstinência Neonatal/tratamento farmacológico , Síndrome de Abstinência Neonatal/genética , Estudos ProspectivosRESUMO
ABSTRACT O sistema opioidérgico envolve a regulação do sono e da vigília. É possível, portanto, que os polimorfismos genéticos no OPRM1 influenciem na qualidade do sono. Este estudo investigou a associação de polimorfismos do OPRM1 com a qualidade subjetiva do sono entre indivíduos sem tratamento prévio com opióides. Este estudo observacional de corte transversal envolveu 161 homens que nunca haviam se tornado opióides (média de idade = 27,74 anos; variação: 18 a 63 anos). A qualidade subjetiva do sono foi avaliada com a versão traduzida e validada em malaio do Índice de Qualidade do Sono de Pittsburgh (PSQI). O DNA foi extraído do sangue total e submetido à reação em cadeia da polimerase (PCR) para dois polimorfismos OPRM1 (118A> G e IVS2 + 691G> C). Sujeitos combinados com 118A e IVS2 + 691Galelos (haplótipo AC) apresentaram escores significativamente mais baixos do PSQI [média (DP) = 4,29 (1,76)] em comparação àqueles sem o haplótipo [4,99 (2,50)] (p = 0,004). Por outro lado, os indivíduos com genótipo heterozigótico combinado (GC / AG diplotipo) apresentaram escores significativamente mais altos do PSQI em comparação àqueles sem o diplótipo [6,04 (2,48) vs 4,54 (2,22), p = 0,004]. Em indivíduos sem tratamento prévio com opiáceos, o haplótipo AC e o diplótipo GC / AG para os polimorfismos 118A> G e IVS2 + 691G> C do OPRM1 estão associados a uma melhor e pior qualidade do sono, respectivamente.
Assuntos
Humanos , Masculino , Adolescente , Adulto , Pessoa de Meia-Idade , Sono/genética , Transtornos do Sono-Vigília , Receptores Opioides mu/análise , Polimorfismo Genético/genética , Receptores Opioides/análiseRESUMO
OBJECTIVE: To investigate whether in utero opioid exposure, which has been linked to adverse neurodevelopmental and social outcomes, is associated with altered DNA methylation of opioid-related genes at birth. STUDY DESIGN: Observational cohort study of 21 healthy methadone-maintained opioid-dependent mother-infant dyads consecutively delivered at >36 weeks of gestation, and 2 comparator groups: smoking, "deprived" opioid-naïve mother-infant dyads (n = 17) and nonsmoking, "affluent" opioid-naïve mother-infant dyads (n = 15). DNA methylation of ABCB1, CYP2D6, and OPRM1 genes for mothers and babies was determined from buccal swabs. Plasma methadone concentrations were additionally measured for methadone-maintained opioid-dependent mothers. RESULTS: DNA methylation for ABCB1 and CYP2D6 was similar in opioid-naïve infants compared with their mothers, but was less for OPRM1 (3 ± 1.6% vs 8 ± 1%, P < .0005). Opioid-exposed newborns had similar DNA methylation to their mothers for all genes studied and greater methylation of ABCB1 (18 ± 4.8% vs 3 ± 0.5%), CYP2D6 (92 ± 1.2% vs 89 ± 2.4%), and OPRM1 (8 ± 0.3% vs 3 ± 1.6%) compared with opioid-naïve newborns (P < .0005 for all 3 genes). Infant DNA methylation was not related to birth weight, length of hospital stay, maternal smoking, dose or plasma concentration of methadone at delivery, or postcode of residence. CONCLUSIONS: In utero exposure to opioids is associated with increased methylation of opioid-related genes in the newborn infant. It is not clear whether these findings are due to opioid exposure per se or other associated lifestyle factors.
Assuntos
Citocromo P-450 CYP2D6/genética , Metilação de DNA , Tratamento de Substituição de Opiáceos/efeitos adversos , Efeitos Tardios da Exposição Pré-Natal/genética , Receptores Opioides mu/genética , Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Adulto , Analgésicos Opioides/efeitos adversos , Analgésicos Opioides/uso terapêutico , Estudos de Casos e Controles , Estudos de Coortes , Feminino , Marcadores Genéticos , Humanos , Recém-Nascido , Metadona/efeitos adversos , Metadona/uso terapêutico , Transtornos Relacionados ao Uso de Opioides/tratamento farmacológico , Gravidez , Complicações na Gravidez/tratamento farmacológico , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Fatores de Risco , Fumar/efeitos adversos , Fatores SocioeconômicosRESUMO
Several single nucleotide polymorphisms (SNPs) in the Mu Opioid Receptor gene (OPRM1) have been identified and associated with a wide variety of clinical phenotypes related both to pain sensitivity and analgesic requirements. The A118G and other potentially functional OPRM1 SNPs show significant differences in their allele distributions among populations. However, they have not been properly addressed in a population genetic analysis. Population stratification could lead to erroneous conclusions when they are not taken into account in association studies. The aim of our study was to analyze OPRM1 SNP variability by comparing population samples of the International Hap Map database and to analyze a new population sample from the city of Corrientes, Argentina. The results confirm that OPRM1 SNP variability differs among human populations and displays a clear ancestry genetic structure, with three population clusters: Africa, Asia, and Europe-America.