AODTH-004 Intestinal epithelial-mesenchymal signalling pathways in homeostasis and inflammation
AODTH-004 Intestinal epithelial-mesenchymal signalling pathways in homeostasis and inflammation
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AODTH-004 稳态和炎症中的肠上皮间质信号通路
DOI：
10.1136/gutjnl-2017-314472.391
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Biswas S
中科院分区：
文献类型：
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作者：
Biswas S
极化的室间形态发生蛋白梯度调节上皮细胞的命运决定。Wnt活性在促进干细胞干细胞性和过渡扩增细胞增殖的隐窝基底处最高，而BMP和Hedgehog（HH）在促进分化的管腔表面处高。炎症诱导粘膜信号梯度的瞬时、调节的不稳定性。我们假设，这促进干/祖细胞的行为在上皮细胞的生理适应性细胞重编程反应的一部分，以影响上皮恢复溃疡healing. Methodindividualcolonic隐窝从健康和发炎的患者microdissection成隐窝顶部，隐窝基地和间充质。使用Illumina微阵列来寻找隔室之间差异表达的基因，并通过qPCR验证结果。通过激光切割和RNASeq评估肌层和隐窝间充质之间的基质信号变化。接下来评估Hedgehog途径对BMP的调节。从正常患者活检组织中培养成纤维细胞，并暴露于HH抑制剂环巴胺。形态破坏进行了评估，在结肠炎的小鼠模型，并在转基因上皮删除HH ligand.ResultsThere预期的表达梯度的Wnt和BMP靶基因之间的上皮组织舱室，但这是不反映内源性配体和受体的表达。在结肠炎中，基因集富集分析显示在隐窝基部增强的转运扩增细胞特征和在隐窝顶部减少的DNA损伤反应基因。在稳态中，1529个基因在空间上不同的基质区域之间差异表达，暗示间充质功能的异质性。在DSS结肠炎中，GREM 1表达在肌层和溃疡床中大量增加。在Ah-Cre; IHHfl/fl小鼠中，存在类似的GREM 1应答，表明HH控制BMP途径。同样，环巴胺成纤维细胞培养导致增加GREM 1的qPCR.ConclusionDisparity之间的靶基因表达和上皮配体/受体表达表明受体独立控制intercompartmentally表达的分子调节信号梯度。在结肠炎中，严格调节的Wnt、BMP和HH梯度失调，使隐窝基底细胞的命运偏向增殖并损害分化细胞DNA损伤response.In稳态上皮Hedgehog信号传导维持BMP配体活性成纤维细胞群并限制GREM 1表达于隐窝下基质。在炎症中，上皮剥脱导致IHH信号传导减少，降低BMP活性并促进周围隐窝分裂以帮助组织恢复。这项工作强调了微环境在调节健康和疾病中上皮细胞命运决定方面的重要性。
IntroductionPolarised intercompartmental morphogen gradients regulate epithelial cell fate determination. Wnt activity is highest at the crypt base promoting stem-cell stemness and transit-amplifying cell proliferation whereas BMP and Hedgehog (HH) are high at the luminal surface promoting differentiation. Inflammation induces transient, regulated instability in mucosal signalling gradients. We hypothesise that this promotes stem/progenitor behaviour in epithelial cells as part of a physiological adaptive cell reprogramming response to effect epithelial restitution in ulcer healing.MethodIndividual colonic crypts from healthy and inflamed patients were microdissected into crypt tops, crypt bases and mesenchyme. Illumina microarrays were used to find genes differentially expressed between compartments, and results validated by qPCR. Stromal signalling variation between the muscularis and intercrypt mesenchyme was assessed by laser dissection and RNASeq.Next regulation of BMP by the Hedgehog pathway was assessed. Fibroblasts were cultured from normal patient biopsies and exposed to HH inhibitor cyclopamine. Morphogen disruption was assessed in a mouse model of colitis, and following transgenic epithelial deletion of HH ligand.ResultsThere were anticipated expression gradients of Wnt and BMP target genes between epithelial tissue compartments but this was not mirrored by endogenous ligand and receptor expression. In colitis, gene set enrichment analysis showed enhanced transit amplifying cell signatures at the crypt base and reduced DNA damage response genes at the crypt top. In homeostasis 1529 genes were differentially expressed between spatially distinct stromal regions intimating mesenchymal functional heterogeneity.In DSS colitis GREM1 expression was massively increased in muscularis layers and ulcer beds. In theAh-Cre; IHHfl/flmouse there was a similar GREM1 response, suggesting control of the BMP pathway by HH. Likewise addition of cyclopamine to fibroblast culture led to increased GREM1 by qPCR.ConclusionDisparity between target gene expression and epithelial ligand/receptor expression suggests receptor-independent control from intercompartmentally expressed molecules regulates signalling gradients. Strictly regulated Wnt, BMP and HH gradients are dysregulated in colitis, skewing crypt basal cell fate towards proliferation and impairing differentiated cell DNA damage response.In homeostasis epithelial Hedgehog signalling maintains a BMP ligand active fibroblast population and restricts GREM1 expression to the subcrypt stroma. In inflammation epithelial denudation leads to reduced IHH signalling, reducing BMP activity and promoting surrounding crypt fission to aid tissue restitution. This work highlights the importance of the microenvironment in regulating epithelial cell fate determination in health and disease.Disclosure of InterestNone Declared