Table_4_Molecular and long-term behavioral consequences of neonatal opioid exposure and withdrawal in mice.XLSX

IntroductionInfants exposed to opioids in utero are at high risk of exhibiting Neonatal Opioid Withdrawal Syndrome (NOWS), a combination of somatic withdrawal symptoms including high pitched crying, sleeplessness, irritability, gastrointestinal distress, and in the worst cases, seizures. The heterogeneity of in utero opioid exposure, particularly exposure to polypharmacy, makes it difficult to investigate the underlying molecular mechanisms that could inform early diagnosis and treatment of NOWS, and challenging to investigate consequences later in life.
MethodsTo address these issues, we developed a mouse model of NOWS that includes gestational and post-natal morphine exposure that encompasses the developmental equivalent of all three human trimesters and assessed both behavior and transcriptome alterations.
ResultsOpioid exposure throughout all three human equivalent trimesters delayed developmental milestones and produced acute withdrawal phenotypes in mice reminiscent of those observed in infants. We also uncovered different patterns of gene expression depending on the duration and timing of opioid exposure (3-trimesters, in utero only, or the last trimester equivalent only). Opioid exposure and subsequent withdrawal affected social behavior and sleep in adulthood in a sex-dependent manner but did not affect adult behaviors related to anxiety, depression, or opioid response.
DiscussionDespite marked withdrawal and delays in development, long-term deficits in behaviors typically associated with substance use disorders were modest. Remarkably, transcriptomic analysis revealed an enrichment for genes with altered expression in published datasets for Autism Spectrum Disorders, which correlate well with the deficits in social affiliation seen in our model. The number of differentially expressed genes between the NOWS and saline groups varied markedly based on exposure protocol and sex, but common pathways included synapse development, the GABAergic and myelin systems, and mitochondrial function.

引言
宫内暴露于阿片类药物的婴儿罹患新生儿阿片类药物戒断综合征（Neonatal Opioid Withdrawal Syndrome，NOWS）的风险极高。该综合征表现为多种躯体戒断症状，包括高调啼哭、睡眠障碍、易激惹、胃肠道不适，严重时可出现惊厥。宫内阿片类药物暴露的异质性，尤其是多重用药暴露的情况，使得探究可为NOWS早期诊断与治疗提供依据的潜在分子机制面临困难，同时也给探究其远期生存结局的工作带来挑战。

研究方法
为解决上述问题，本研究构建了新生儿阿片类药物戒断综合征小鼠模型，该模型包含妊娠期与产后吗啡暴露，覆盖对应人类妊娠三个孕期的发育阶段，并对小鼠的行为学改变与转录组（transcriptome）变化进行了评估。

研究结果
在对应人类全部三个孕期的阿片类药物暴露后，小鼠出现了发育里程碑延迟以及急性戒断表型，该表型与人类婴儿中观察到的症状相似。本研究还发现，根据阿片类药物暴露的时长与时机（全孕期暴露、仅宫内暴露、仅对应妊娠晚期暴露）的不同，基因表达模式存在差异。阿片类药物暴露及后续戒断反应会以性别依赖性方式影响成年小鼠的社交行为与睡眠，但未对其焦虑、抑郁或阿片类药物应答相关的成年行为产生影响。

讨论
尽管出现了明显的戒断反应与发育迟缓，但通常与物质使用障碍相关的长期行为缺陷程度较轻。值得注意的是，转录组分析显示，自闭症谱系障碍（Autism Spectrum Disorders，ASD）已发表数据集里的差异表达基因（differentially expressed genes）出现显著富集，这与本研究模型中观察到的社交联结缺陷高度相关。根据暴露方案与小鼠性别的不同，新生儿阿片类药物戒断综合征模型组与生理盐水对照组之间的差异表达基因数量存在显著差异，但共同富集的通路包括突触发育、γ-氨基丁酸能系统与髓鞘系统，以及线粒体功能。