Abstract：
Menopausal women often face long-term estrogen treatment. G protein-coupled estrogen receptor (GPER) expressed in intestinal crypt was activated by estrogen therapy, but it was unclear whether chronic GPER activation during menopause had an effect on intestinal stem cells (ISCs). We tested the effect of chronic GPER activation on ISCs of ovariectomized (OVX) mice by injection of the selective GPER agonist G-1 for 28 days, or G-1 stimulation of organoids derived from crypts of OVX mice. G-1 up-regulated crypt depth, the number of Ki67+, bromodeoxyuridine+ cells and Olfm4+ ISCs, and the expression of ISCs marker genes (Lgr5, Olfm4 and Axin2). G-1 administration promoted organoid growth, increased the number of EdU+ cells per organoid and protein expression of Cyclin D1 and cyclin B1 in organoids. After G-1 treatment in vivo or in vitro, Paneth cell-derived Wnt3, Wnt3 effector β-catenin and Wnt target genes c-Myc and Cyclin D1 increased in ileum or organoids. Once blocking the secretion of Wnt3 from Paneth cells, the effects of G-1 on organoids growth, ISCs marker genes and Wnt/β-catenin signaling were abolished. G-1 did not affect the number of Paneth cells in ex vivo organoids, while activated Mmp7/cryptdin program in Paneth cells, promoted their maturation, and increased the expression of lysozyme protein. G-1 pretreatment in OVX mice inhibited radiation-induced ISCs proliferation injury and enhanced the resistance of mice to intestinal injury. In conclusion, chronic GPER activation prompted the Wnt3 synthesis in Paneth cells, thus increased the proliferation of ISCs via activation of Wnt3/β-catenin signaling in OVX mice.
摘要：
更年期妇女经常面临长期的雌激素治疗。肠隐窝中表达的G蛋白偶联雌激素受体（GPER）被雌激素治疗激活，但目前尚不清楚绝经期间的慢性GPER激活是否对肠干细胞(ISC)有影响.我们通过注射选择性GPER激动剂G-128天测试了慢性GPER激活对卵巢切除（OVX）小鼠ISC的影响，或来自OVX小鼠隐窝的类器官的G-1刺激。G-1上调隐窝深度,Ki67+的数量，溴脱氧尿苷+细胞和Olfm4+ISC，和ISC标记基因(Lgr5、Olfm4和Axin2)的表达。G-1给药促进类器官生长，增加每个类器官的EdU细胞数量以及类器官中CyclinD1和CyclinB1的蛋白表达。体内或体外G-1处理后，潘氏细胞衍生的Wnt3，Wnt3效应子β-catenin和Wnt靶基因c-Myc和CyclinD1在回肠或类器官中增加。一旦阻断潘氏细胞分泌Wnt3，G-1对类器官生长的影响，ISC标记基因和Wnt/β-catenin信号传导被废除。G-1不影响离体器官中Paneth细胞的数量，在Paneth细胞中激活Mmp7/cryptdin程序时，促进了他们的成熟，并增加溶菌酶蛋白的表达。G-1预处理能抑制OVX小鼠辐射诱导的ISC增殖损伤,增强小鼠对肠道损伤的抵抗力。总之,慢性GPER激活促进了Paneth细胞中Wnt3的合成，因此，通过激活OVX小鼠中Wnt3/β-catenin信号传导增加了ISC的增殖。
