Conditional cell reprogramming involves non-canonical β-catenin activation and mTOR-mediated inactivation of Akt.
Conditional cell reprogramming involves non-canonical β-catenin activation and mTOR-mediated inactivation of Akt.
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有条件的细胞重编程涉及非传统的β-catenin激活和MTOR介导的Akt失活。
DOI：
10.1371/journal.pone.0180897
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发表时间：
2017
期刊：
影响因子：
3.7
通讯作者：
Schlegel R
中科院分区：
文献类型：
--
作者：
Suprynowicz FA;Kamonjoh CM;Krawczyk E;Agarwal S;Wellstein A;Agboke FA;Choudhury S;Liu X;Schlegel R
辐照的成纤维细胞饲养细胞和Rho激酶抑制剂Y-267362的组合将体外生长的原代上皮细胞转化为以长期增殖为特征的未分化成体干细胞样状态。这种细胞培养方法还维持了来自各种组织的成体上皮干细胞的增殖。原代干细胞和成体干细胞在去除培养条件后均保留其组织特异性分化潜能。由于能够调节细胞的增殖和分化，这种方法被称为条件性重编程，并且越来越多地用于肿瘤异质性、个性化医学和再生医学的研究。然而，对这些条件性重编程（CR）细胞的生物学知之甚少。先前我们表明，β-连环蛋白激活，体内干细胞的标志，发生在CR人子宫颈外细胞（HEC）。在这里，我们表明β-连环蛋白依赖性转录是诱导上皮干细胞标志物所必需的，并且β-连环蛋白通过不依赖于Wnt和Akt/GSK-3的非经典途径被激活。由于mTOR信号传导增加，活性Akt实际上减少，从而增加去磷酸化的活性GSK-3。尽管活性GSK-3增加，但β-连环蛋白与蛋白磷酸酶2A（PP 2A）结合并被激活。PP 2A催化活性的抑制降低了活性β-连环蛋白的水平和干细胞标志物的急性诱导，表明PP 2A在β-连环蛋白的活化中起重要作用。此外，我们使用人前列腺和乳腺细胞证明了类似的结果，表明这些变化并不局限于宫颈上皮细胞，可能代表了条件性重编程的一个更基本的属性。
The combination of irradiated fibroblast feeder cells and Rho kinase inhibitor, Y-267362, converts primary epithelial cells growing in vitro into an undifferentiated adult stem cell-like state that is characterized by long-term proliferation. This cell culture method also maintains the proliferation of adult epithelial stem cells from various tissues. Both primary and adult stem cells retain their tissue-specific differentiation potential upon removal of the culture conditions. Due to the ability to modulate the proliferation and differentiation of the cells, this method is referred to as conditional reprogramming and it is increasingly being used in studies of tumor heterogeneity, personalized medicine and regenerative medicine. However, little is known about the biology of these conditionally reprogrammed (CR) cells. Previously we showed that β-catenin activation, a hallmark of stem cells in vivo, occurs in CR human ectocervical cells (HECs). Here we show that β-catenin-dependent transcription is necessary for the induction of epithelial stem cell markers, and that β-catenin is activated via a non-canonical pathway that is independent of Wnt and Akt/GSK-3. Active Akt actually decreases due to increased mTOR signaling, with a consequent increase in dephosphorylated, active GSK-3. Despite the increase in active GSK-3, β-catenin associates with protein phosphatase 2A (PP2A) and is activated. Inhibition of PP2A catalytic activity reduces both the level of active β-catenin and the acute induction of stem cell markers, suggesting an important role for PP2A in the activation of β-catenin. Moreover, we demonstrate similar results using human prostate and breast cells, indicating that these changes are not restricted to ectocervical epithelial cells and may represent a more fundamental property of conditional reprogramming.
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DOI：
10.1038/jid.2008.445
发表时间：
2009-07
期刊：
The Journal of investigative dermatology
影响因子：
--
作者：
Chien AJ;Conrad WH;Moon RT
通讯作者：
Moon RT
影响因子：
4.8
作者：
Calautti, E;Li, J;Goetinck, PF
通讯作者：
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影响因子：
11.8
作者：
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通讯作者：
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影响因子：
5.4
作者：
Krawczyk, Ewa;Suprynowicz, Frank A.;Schlegel, Richard
通讯作者：
Schlegel, Richard
影响因子：
5.6
作者：
Ji X;Huang Q;Yu L;Nussinov R;Ma B
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