Analysis of differential gene expression in the choroid plexus (ChP) of E16.5 and P60 mice

Age-appropriate regulation of cerebrospinal fluid (CSF) dynamics including production, flow, and clearance (e.g. via glymphatics and dural lymphatics) is essential for brain health. The choroid plexus (ChP) is an important compartment in CSF dynamics but its contribution is poorly understood. To identify temporally regulated ChP epithelial cell functions that may relate to increased ATP demand, we investigated transcripts that are prioritized for translation, therefore reflecting the functional preference of the ChP tissue. We employed Translating Ribosomal Affinity Purification. We identified ChP Na-K-Cl co-transporter [NKCC1] as developmentally regulated, in both expression and function, by mechanisms ranging from epigenetic (NuRD) to post-translational, coupled with increased ATP production. Premature NKCC1 overexpression in ChP accelerated CSF [K+] reduction, reduced ventricle size, and increased intracranial compliance by adulthood as measured by a murine intracranial pressu re monitor paired serially with MRI. Our data point to a critical developmental period when ChP transiently absorbs CSF through NKCC1-mediated K+ transport, which bears implications on lifelong brain fluid homeostasis and health. 3 mice per age (collected at 9am) TRAP mRNAs were isolated and sequenced from the choroid plexus (ChP) of E16.5 and P60 mice脑脊液（CSF）动力学的年龄适配调控，包括生成、流动与清除（例如通过胶质淋巴系统与硬脑膜淋巴系统），对大脑健康至关重要。脉络丛（ChP）是脑脊液动力学中的关键结构，但其具体贡献尚未得到充分阐明。为了鉴定可能与ATP需求增加相关的、受时间调控的脉络丛上皮细胞功能，我们对优先进行翻译的转录本进行了分析，以此反映脉络丛组织的功能偏好。本研究采用了翻译核糖体亲和纯化（TRAP）技术。我们发现脉络丛中的钠钾氯协同转运蛋白1（NKCC1）在发育进程中受到从表观遗传调控（核小体重塑与去乙酰化酶复合物，NuRD）到翻译后修饰等多种机制的调控，其表达与功能均发生改变，同时伴随ATP生成水平的升高。在发育早期的脉络丛中过表达NKCC1，可加速成年小鼠脑脊液钾离子（K+）水平的下降，缩小脑室体积；通过连续结合磁共振成像（MRI）的小鼠颅内压监测实验证实，成年后小鼠的颅内顺应性显著升高。我们的研究结果表明，存在一个关键的发育窗口期，此时脉络丛可通过NKCC1介导的钾离子转运短暂吸收脑脊液，这一发现对维持终生脑液稳态与大脑健康具有重要启示。本研究共纳入各年龄组小鼠3只（于每日上午9时处死取材），我们从胚胎16.5天（E16.5）与出生后60天（P60）小鼠的脉络丛中分离得到经TRAP标记的mRNA并进行测序。