SOX9 maintains reserve stem cells and preserves radioresistance in mouse small intestine.
SOX9 maintains reserve stem cells and preserves radioresistance in mouse small intestine.
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DOI：
10.1053/j.gastro.2015.07.004
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发表时间：
2015-11
期刊：
影响因子：
29.4
通讯作者：
Magness ST
中科院分区：
文献类型：
--
作者：
Roche KC;Gracz AD;Liu XF;Newton V;Akiyama H;Magness ST
储备肠干细胞（rISCs）在稳态条件下静止/缓慢循环，允许用标记保留测定法对其进行鉴定。rISCs通过转化为主动增殖干细胞（aISCs）来介导组织损伤后的上皮再生，所述主动增殖干细胞（aISCs）自我更新并表现出多能性，这是干细胞的定义性质。关于调控rISCs产生和维持的遗传机制知之甚少。转录因子Sox 9（Sox 9 high）的高表达水平与rISCs相关。本研究探讨了SOX 9在调节rISC状态中的作用。我们使用荧光激活的细胞分选从Lgr 5EGFP和Sox 9 EGFP报告小鼠分离定义为aISC（Lgr 5 high）和rISC（Sox 9 high）的细胞。通过单细胞基因表达分析，在Lgr 5 high和Sox 9 high群体中评估了与活性和储备ISC相关的其他标志物的表达。我们使用标记保留试验来鉴定Sox 9 high细胞是否为标记保留细胞（LRC）。在Sox 9-CreERT 2小鼠中进行谱系追踪实验以测量表达Sox 9的细胞的干细胞能力和辐射抗性。使用条件性S 0X 9敲除小鼠和诱导性条件性S 0X 9敲除小鼠来确定是否需要S 0X 9来维持LRC和rISC功能。Lgr 5 high和基于隐窝的Sox 9 high细胞的子集共表达aISC和rISC的标志物（Lgr 5. Bmi 1。Lrig 1和Hopx）。LRC表达高水平的Sox 9，并且在Sox 9敲除小鼠中丢失。SOX 9是高剂量辐射后上皮再生所必需的。与对照小鼠相比，来自SOX 9敲除小鼠的隐窝对辐射的敏感性增加，这不能归因于受损的细胞周期停滞或DNA修复。S 0X 9限制LRC中的增殖并赋予小鼠中rISC辐射抗性。
Reserve intestinal stem cells (rISCs) are quiescent/slowly cycling under homeostatic conditions, allowing for their identification with label-retention assays. rISCs mediate epithelial regeneration after tissue damage by converting to actively proliferating stem cells (aISCs) that self renew and demonstrate multipotency, which are defining properties of stem cells. Little is known about the genetic mechanisms that regulate the production and maintenance of rISCs. High expression levels of the transcription factor Sox9 (Sox9high) are associated with rISCs. This study investigates the role of SOX9 in regulating the rISC state. We used fluorescence-activated cell sorting to isolate cells defined as aISCs (Lgr5high) and rISCs (Sox9high) from Lgr5EGFP and Sox9EGFP reporter mice. Expression of additional markers associated with active and reserve ISCs were assessed in Lgr5high and Sox9high populations by single-cell gene expression analyses. We used label-retention assays to identify whether Sox9high cells were label-retatining cells (LRCs). Lineage-tracing experiments were performed in Sox9-CreERT2 mice to measure the stem cell capacities and radioresistance of Sox9-expressing cells. Conditional SOX9 knockout mice and inducible-conditional SOX9 knockout mice were used to determine whether SOX9 was required to maintain LRCs and rISC function. Lgr5high and a subset of crypt-based Sox9high cells co-express markers of aISC and rISC (Lgr5. Bmi1. Lrig1, and Hopx). LRCs express high levels of Sox9 and are lost in SOX9-knockout mice. SOX9 is required for epithelial regeneration after high-dose irradiation. Crypts from SOX9-knockout mice have increased sensitivity to radiation, compared with control mice, which could not be attributed to impaired cell-cycle arrest or DNA repair. SOX9 limits proliferation in LRCs and imparts radiation resistance to rISCs in mice.