垂体（pituitary）是下丘脑-垂体-肾上腺 （HPA） 轴的重要枢纽。垂体激素分泌细胞 （HPC） 释放多种激素，以在正常和压力条件下调节基本身体功能。垂体内分泌腺通过释放促肾上腺皮质激素 （ACTH） 来调节免疫系统，以响应下丘脑的神经元激活。然而，目前尚不清楚全身炎症如何调节垂体HPC的转录组学特征。在这里，我们对小鼠垂体进行了单细胞RNA测序（scRNA-seq），发现在炎症发生时，所有主要的垂体HPC都以细胞类型特异性方式产生强烈反应，其中皮质促物表现出强烈的反应。全身炎症还导致非典型生物活性分子的产生和释放，包括皮质激素的 Nptx2，以调节免疫稳态。同时，HPCs上调了趋化因子的基因表达，促进了HPCs与免疫细胞之间的通讯。总之，我们的研究揭示了垂体和免疫系统之间的广泛相互作用，表明垂体在介导炎症对身体生理学许多方面的影响方面发挥着多方面的作用。
Mice were anesthetized with pentobarbital (80 mg/kg, i.p.) before surgery and then placed in a mouse stereotaxic instrument. Injections were performed using a microsyringe pump and a Micro4 controller (World Precision Instruments). For macrophage depletion, liposome-PBS or liposome-Clodronate (Liposoma,CP-005-005) was stereotaxically microinjected into the anterior pituitary (2.5 mm posterior from Bregma, 0.4 mm lateral, 6 mm below pia). The liposomes were delivered to the target site at a rate of 60 nL/min for 500 nL per site. Mice received saline or 0.5 mg/kg LPS 18 h after liposome delivery and were killed 6 h after inflammation was established. For CCL2 expression and Nptx2-KO, AAV was delivered directly into the pituitary. The injection site, rate, and volume were the same as those used for the liposome injection. Subsequent experiments were performed at least 3 weeks after virus injection.
(C) Representative images showing Iba1 (the marker of macrophage) expression in the pituitary from mice that received liposome-PBS (left) or liposome-Clodronate (right) directly to the pituitary for 24 h. Scale bar, 100 μm.
(D) Serum concentrations of ACTH in saline- or LPS-treated (0.5 mg/kg LPS for 6 h) mice pretreated with liposome-PBS or liposome-Clodronate (n = 4–7 mice).
(E) Serum concentrations of corticosterone in LPS-treated (0.5 mg/kg LPS for 6 h) mice pretreated with liposome-PBS or liposome-Clodronate (n = 6–7 mice).
