Department of Neurosurgery, Graduate School of Medicine, Nagoya University, Nagoya, Japan.
Department of Endocrinology and Diabetes, Graduate School of Medicine, Nagoya University, Nagoya, Japan.
Front Endocrinol (Lausanne). 2023 Mar 2;14:1130465. doi: 10.3389/fendo.2023.1130465. eCollection 2023.
The pituitary gland, regulating various hormones, is central in the endocrine system. As spontaneous recovery from hypopituitarism is rare, and exogenous-hormone substitution is clumsy, pituitary replacement regenerative medicine, using pluripotent stem cells, is desirable. We have developed a differentiation method that in mice yields pituitary organoids (POs) derived from human embryonic stem cells (hESC). Efficacy of these POs, transplanted subcutaneously into hypopituitary mice, in reversing hypopituitarism was studied.
hESC-derived POs were transplanted into inguinal subcutaneous white adipose tissue (ISWAT) and beneath dorsal skin, a relatively avascular region (AR), of hypophysectomized severe combined immunodeficient (SCID) mice. Pituitary function was evaluated thereafter for ¾ 6mo, assaying basal plasma ACTH and ACTH response to corticotropin-releasing hormone (CRH) stimulation. Histopathologic examination of organoids 150d after transplantation assessed engraftment. Some mice received an inhibitor of vascular endothelial growth factor (VEGF) to permit assessment of how angiogenesis contributed to subcutaneous engraftment.
During follow-up, both basal and CRH-stimulated plasma ACTH levels were significantly higher in the ISWAT group ( < 0.001 - 0.05 and 0.001 - 0.005, respectively) than in a sham-operated group. ACTH secretion also was higher in the ISWAT group than in the AR group. Histopathologic study found ACTH-producing human pituitary-cell clusters in both groups of allografts, which had acquired a microvasculature. POs qPCR showed expression of angiogenetic factors. Plasma ACTH levels decreased with VEGF-inhibitor administration.
Subcutaneous transplantation of hESC-derived POs into hypopituitary SCID mice efficaciously renders recipients ACTH-sufficient.
垂体作为内分泌系统的核心，调节着各种激素。由于垂体功能减退症患者自发恢复的情况很少见，而外源性激素替代治疗又很笨拙，因此，使用多能干细胞进行垂体再生医学治疗是很有必要的。我们已经开发出一种分化方法，可以在小鼠中产生源自人胚胎干细胞（hESC）的垂体类器官（POs）。研究了将这些 POs 移植到垂体功能减退症小鼠的腹股沟皮下白色脂肪组织（ISWAT）和背侧皮肤（AR）下，以逆转垂体功能减退症的疗效。
将 hESC 衍生的 POs 移植到严重联合免疫缺陷（SCID）小鼠的腹股沟皮下白色脂肪组织（ISWAT）和背侧皮肤（AR）下，这是一个相对无血管的区域（AR）。此后，评估了垂体功能，持续了 6 个月，检测基础血浆促肾上腺皮质激素（ACTH）和促肾上腺皮质激素释放激素（CRH）刺激后的 ACTH 反应。在移植后 150 天对类器官进行组织病理学检查，评估移植物的植入情况。一些小鼠接受了血管内皮生长因子（VEGF）抑制剂的治疗，以评估血管生成对皮下植入的贡献。
在随访期间，ISWAT 组的基础和 CRH 刺激后的血浆 ACTH 水平均明显高于假手术组（<0.001-0.05 和 0.001-0.005，分别）。ISWAT 组的 ACTH 分泌也高于 AR 组。组织病理学研究发现，两组同种异体移植物中均有 ACTH 分泌的人垂体细胞簇，并获得了微血管。POs 的 qPCR 显示出血管生成因子的表达。给予 VEGF 抑制剂后，血浆 ACTH 水平下降。
将 hESC 衍生的 POs 皮下移植到垂体功能减退症的 SCID 小鼠体内，能有效地使受者获得足够的 ACTH。
