miR-325-3p介导缺氧缺血性脑损伤后松果体功能紊乱的机制研究

新生儿缺氧缺血性脑损伤(HIBD)常遗留昼夜节律紊乱，但机制未明。临床研究显示松果体功能损伤导致的神经内分泌障碍可能是主要病理过程。本课题工作基础提示HIBD后大鼠松果体和血清中褪黑素（MT）合成关键酶AANAT，MT 节律长期表达紊乱，而miR-325-3p 表达持续升高。生物信息学预测Aanat是miR-325-3p下游靶标, 因此我们设想：HIBD后miR-325-3p的异常升高通过影响Aanat的表达导致松果体分泌MT节律紊乱。本课题拟在细胞层面验证miR-325-3p和Aanat的相互作用，并在组织病理和行为学层面探索miR-325-3p对松果体功能的远期影响。同时模拟HIBD病理，研究不同伤害刺激对miR-325-3p、Aanat表达影响。miR-325-3p与松果体功能的关系未见报道，因此，本研究为HIBD后节律紊乱的机制研究和防治提供了新靶标。

Hypoxic-ischemic brain damage (HIBD) survivals are commonly accompanied by circadian rhythm disorders, although the underlying mechanisms are largely unknown. Clinical studies indicated that the neuroendocrine disorders induced by pineal injury might be a key pathophysiologic factor. Our previous research suggested a chronic impairment of Aanat, a key regulator for melatonin (MT) synthesis, MT expression in the pineal gland and serum of rats with HIBD. Meanwhile, we identified that one microRNA, miR-325-3p, was robustly expressed in a high level in the pineal gland after HIBD. Given that Aanat mRNA is bioinfomatically predicted as a downstream target of miR-325-3p, we hypothesized that the over-expression of miR-325-3p hampers AANAT expression in the pineal gland, and therefore the rhythmic synthesis of MT after HIBD. To test our hypothesis, we intend to analyze whether miR-325-3p interacts with Aanat mRNA and how miR-325-3p affects its expression. We will also explore the long-term effects on pathology and behavioral changes induced by miR-325-3p overexpression or silencing in vivo. Last, we will investigate how different stimuli that mimic HIBD affect the expression of miR-325-3p, AANAT in cultured pineal gland cells. The role of miR-325-3p on pineal function has not been reported, our study therefore provides new insights on the pathophysiological mechanisms of circadian dysfunction and potential therapeutic target after HIBD.