Increased expression of hras induces early, but not full, senescence in the immortal fish cell line, EPC
Increased expression of hras induces early, but not full, senescence in the immortal fish cell line, EPC
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DOI：
10.1016/j.gene.2020.145116
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发表时间：
2021-01-10
期刊：
影响因子：
3.5
通讯作者：
Katagiri, Takayuki
中科院分区：
文献类型：
--
作者：
Futami, Kunihiko;Aoyama, Kako;Katagiri, Takayuki
与包括人类在内的大多数哺乳动物相比，鱼类细胞系长期以来一直被认为是不朽的，尽管没有转化，但几乎没有细胞衰老的迹象。最近，我们的实验室报道了5-氮杂-2 '-脱氧胞苷（5-Aza-dC）的DNA去甲基化诱导永生鱼类细胞系EPC（Epithelioma papulosum cyprini）的端粒非依赖性细胞衰老和衰老相关分泌表型（SASP）。然而，目前还不知道鱼来源的培养细胞通常如何在体外抗老化。在本研究中，我们集中在Ras，它执行的主要作用Ras诱导的衰老（RIS），并调查Ras在EPC细胞衰老的调节中的作用。结果表明，5-Aza-dC诱导EPC细胞ras（hras，kras，nras）基因表达。过表达HRas或其组成型活性形式（HRas（v12））的EPC细胞显示p53依赖性衰老样生长停滞和衰老相关β-半乳糖苷酶（SA-β-gal）活性，具有细胞衰老的大和/或扁平形态特征。另一方面，SASP未被诱导。这些结果表明，HRas的表达增加有助于EPC细胞的早期衰老，但它本身可能不足以完全衰老，即使HRas被异常激活。因此，RIS的有限机制可能在鱼类细胞系的抗衰老中发挥作用。
In contrast to most mammals including human, fish cell lines have long been known to be immortal, with little sign of cellular senescence, despite the absence of transformation. Recently, our laboratory reported that DNA demethylation with 5-aza-2'-deoxycytidine (5-Aza-dC) induces telomere-independent cellular senescence and senescence-associated secretory phenotype (SASP) in an immortal fish cell line, EPC (Epithelioma papulosum cyprini). However, it is not known how fish derived cultured cells are usually resistant to aging in vitro. In this study, we focused on Ras, which carries out the main role of Ras-induced senescence (RIS), and investigated the role of Ras in the regulation of senescence in EPC cells. Our results show that 5-Aza-dC induced the expression of the ras (hras, kras, nras) gene in EPC cells. EPC cells overexpressing HRas or its constitutively active form (HRas(v12)) showed p53-dependent senescence-like growth arrest and senescence-associated beta-galactosidase (SA-beta-gal) activity with a large and/or flat morphology characteristic of cell senescence. On the other hand, the SASP was not induced. These results imply that the increased expression of HRas contributes to early senescence in EPC cells, but it alone may not be sufficient for the full senescence, even if HRas is aberrantly activated. Thus, the limited mechanism of RIS may play a role in the senescence-resistance of fish cell lines.