Sample Details.

The Center for Disease Control’s National Birth Defects Prevention Study data suggests that maternal nicotine use may increase the incidence of craniofacial birth defects and growth anomalies like craniosynostosis, cleft palate, and/or lip in offspring. Craniofacial growth proceeds by expansion at fibrous sutures and synchondroses. In the cranial base, synchondroses, which are cartilaginous joints, play a major role in craniofacial development including neurocranial expansion and facial outgrowth. Our previous data showed alterations in craniofacial structures with intrauterine exposure to nicotine. As the use of nicotine is increasing among youths, especially through use of electronic nicotine delivery systems, there is a great need to investigate the critical periods of nicotine exposure during pregnancy and postnatal development. Alterations in craniofacial growth that occur in response to maternal nicotine use must be understood in order to prevent debilitating conditions. For this investigation, we utilized cephalometric and histomorphometric analyses to investigate how nicotine exposure alters craniofacial development in offspring modeling maternal nicotine exposure either during pregnancy and lactation or post-partum lactation only compared with unexposed controls. Our results in mice showed significant changes in craniofacial dimensions and some specificity for effects in the synchondroses across the three experimental groups including significant changes in the cellular and the extracellular collagen matrix components of these growth centers. The most dramatic effects segregated to the lactation only exposed group, which is a major target from a prevention point of view as there is a common misconception among the public that nicotine cessation during pregnancy is sufficient for prevention of ill effects in the offspring.

美国疾病控制与预防中心（Center for Disease Control, CDC）国家出生缺陷预防研究的数据表明，母体尼古丁摄入可能会提升子代罹患颅面部出生缺陷及生长异常的风险，例如颅缝早闭（craniosynostosis）、腭裂（cleft palate）和/或唇裂（cleft lip）。颅面部生长通过纤维骨缝（fibrous sutures）与软骨结合处（synchondroses）的扩张得以实现。在颅底区域，作为软骨关节的软骨结合处，在颅面部发育（包括神经颅扩张与面部生长）中发挥核心作用。我们此前的研究数据已证实，宫内暴露（intrauterine exposure）尼古丁会导致子代颅面部结构出现异常改变。当前青少年尼古丁使用率持续攀升，尤其是通过电子尼古丁传送系统（electronic nicotine delivery systems, ENDS）使用尼古丁，因此亟需探究孕期与产后发育阶段尼古丁暴露的关键窗口期。为预防此类致残性疾病，必须明确母体尼古丁暴露所引发的颅面部生长改变机制。本研究采用头影测量（cephalometric）与组织形态计量学（histomorphometric）分析方法，以未暴露对照组为参照，针对两种母体尼古丁暴露建模方式——孕期联合哺乳期暴露、仅产后哺乳期暴露——探究尼古丁暴露对子代颅面部发育的影响。小鼠实验结果显示，三个实验组的颅面部尺寸均出现显著变化，且软骨结合处的效应具有一定特异性，包括这些生长中心的细胞与细胞外胶原基质成分发生显著改变。其中最显著的效应集中于仅哺乳期暴露组，从预防视角来看这是关键靶标——因为公众普遍存在认知误区，认为孕期戒烟即可预防子代出现各类不良健康后果。