Supplementary Material for: Alterations in serum miR-126-3p levels over time, a marker of pituitary insufficiency following head trauma

TBI is a condition caused by a head injury that poses a high risk of developing pituitary insufficiency in patients. We have previously reported alterations in miR-126-3p levels in sera from patients with TBI-induced pituitary deficiency. To investigate why TBI-induced pituitary deficiency develops in only some patients and to reveal the relationship of miR-126-3p with the hormone axes, we used mice epigenetically modified with miR-126-3p at the embryonic stage in this study. These modified mice were subjected to mild-TBI(mTBI) according to the Marmarou-weight-drop model. The alterations of miR-126-3p levels after mTBI of both wild-type and modified-miR-126-3p* lines of mice validated our human results. In addition, the hypothalamus, pituitary, and adrenal tissues were analyzed for the related transcripts and serum hormone levels. We report that mir-126-3p directly affects the upregulation of the Hypothamus-Pituitary-Adrenal (HPA) axis and ACTH secretion in the acute phase after mTBI. We have also demonstrated that miR-126-3p suppresses Gnrh transcripts in the hypothalamus and pituitary, but this is not reflected in FSH/LH serum levels. The increase in ACTH levels in the acute phase may indicate that the up-regulation of miR-126-3p has a protective effect on the HPA axis after TBI. Notably, the most prominent transcript response is found in the adrenals, highlighting their role in the pathophysiology of TBI. Our study revealed the role of miR-126-3p in TBI and pituitary deficiency developing after TBI, and the data obtained will significantly contribute to unraveling the mechanism of pituitary deficiency developing after TBI and developing new diagnostic and treatment strategies.

创伤性脑损伤（Traumatic Brain Injury，TBI）是一类由头部外伤引发的病症，患者罹患垂体功能减退的风险极高。我们此前曾报道过创伤性脑损伤诱导性垂体功能减退患者血清中miR-126-3p（microRNA-126-3p）水平的异常变化。为探究为何仅部分患者会出现创伤性脑损伤诱导性垂体功能减退，并阐明miR-126-3p与激素轴之间的关联，本研究选取了胚胎阶段经miR-126-3p表观遗传修饰的小鼠作为实验对象。本研究依据Marmarou失重坠落模型，对这些修饰小鼠实施轻度创伤性脑损伤（mild Traumatic Brain Injury，mTBI）造模。野生型小鼠与miR-126-3p*修饰品系小鼠在接受轻度创伤性脑损伤后，其miR-126-3p水平的变化验证了我们的人体实验结果。此外，本研究还对下丘脑、垂体及肾上腺组织的相关转录本以及血清激素水平进行了分析。本研究证实，miR-126-3p可直接影响轻度创伤性脑损伤后急性期下丘脑-垂体-肾上腺（Hypothalamus-Pituitary-Adrenal，HPA）轴的上调以及促肾上腺皮质激素（Adrenocorticotropic Hormone，ACTH）的分泌。我们还证实，miR-126-3p可抑制下丘脑与垂体中的促性腺激素释放激素（Gonadotropin-Releasing Hormone，GnRH）转录本表达，但该效应并未在血清促卵泡激素（Follicle-Stimulating Hormone，FSH）与黄体生成素（Luteinizing Hormone，LH）水平中体现出来。急性期血清ACTH水平的升高，提示miR-126-3p的上调对创伤性脑损伤后的HPA轴具有保护作用。值得注意的是，肾上腺组织中的转录本响应最为显著，这突出了其在创伤性脑损伤病理生理过程中的作用。本研究揭示了miR-126-3p在创伤性脑损伤及创伤性脑损伤后垂体功能减退发生发展中的作用，所获数据将为阐明创伤性脑损伤后垂体功能减退的发病机制、开发新型诊断与治疗策略提供重要支撑。