Supplementary Material for: Human Umbilical Cord Blood Therapy Protects Cerebral White Matter from Systemic LPS Exposure in Preterm Fetal Sheep

<b><i>Background:</i></b> Infants born preterm following exposure to in utero inflammation/chorioamnionitis are at high risk of brain injury and life-long neurological deficits. In this study, we assessed the efficacy of early intervention umbilical cord blood (UCB) cell therapy in a large animal model of preterm brain inflammation and injury. We hypothesised that UCB treatment would be neuroprotective for the preterm brain following subclinical fetal inflammation. <b><i>Methods:</i></b> Chronically instrumented fetal sheep at 0.65 gestation were administered lipopolysaccharide (LPS, 150 ng, 055:B5) intravenously over 3 consecutive days, followed by 100 million human UCB mononuclear cells 6 h after the final LPS dose. Controls were administered saline instead of LPS and cells. Ten days after the first LPS dose, the fetal brain and cerebrospinal fluid were collected for analysis of subcortical and periventricular white matter injury and inflammation. <b><i>Results:</i></b> LPS administration increased microglial aggregate size, neutrophil recruitment, astrogliosis and cell death compared with controls. LPS also reduced total oligodendrocyte count and decreased mature myelinating oligodendrocytes. UCB cell therapy attenuated cell death and inflammation, and recovered total and mature oligodendrocytes, compared with LPS. <b><i>Conclusions:</i></b> UCB cell treatment following inflammation reduces preterm white matter brain injury, likely mediated via anti-inflammatory actions.

<b><i>研究背景：</i></b> 暴露于子宫内炎症/绒毛膜羊膜炎的早产新生儿，罹患脑损伤及终身神经功能缺损的风险极高。本研究针对早产性脑炎症与损伤的大型动物模型，评估了早期干预性脐带血（Umbilical Cord Blood, UCB）细胞疗法的疗效。我们提出假说：在亚临床胎儿炎症发生后，UCB治疗可对早产大脑发挥神经保护作用。
<b><i>研究方法：</i></b> 对妊娠进度为0.65的慢性仪器化胎羊，连续3天静脉注射脂多糖（Lipopolysaccharide, LPS，150 ng，血清型055:B5），于末次LPS给药6小时后输注1亿个人类UCB单个核细胞。对照组仅注射生理盐水，不给予LPS与细胞制剂。于首次LPS给药后10天，采集胎羊大脑与脑脊液，用于分析皮层下及脑室周围白质损伤与炎症情况。
<b><i>研究结果：</i></b> 与对照组相比，LPS给药可提升小胶质细胞聚集体尺寸、中性粒细胞募集水平、星形胶质细胞增生程度及细胞死亡量。LPS同时降低了少突胶质细胞总数量，并减少了成熟髓鞘形成型少突胶质细胞的占比。与LPS组相比，UCB细胞疗法可减轻细胞死亡与炎症反应，并恢复少突胶质细胞总数及成熟少突胶质细胞数量。
<b><i>研究结论：</i></b> 炎症发生后给予UCB细胞治疗，可减轻早产性脑白质损伤，其作用机制可能与抗炎效应相关。