Leucine reduces the proliferation of MC3T3-E1 cells through DNA damage and cell senescence
Leucine reduces the proliferation of MC3T3-E1 cells through DNA damage and cell senescence
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DOI：
10.1016/j.tiv.2017.12.015
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发表时间：
2018-04-01
影响因子：
3.2
通讯作者：
de Oliveira, Jarbas Rodrigues
中科院分区：
文献类型：
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作者：
Dias, Raquel da Luz;Basso, Bruno;de Oliveira, Jarbas Rodrigues
亮氨酸（Leucine, Leu）是一种必需的支链氨基酸，存在于乳制品中，因其在细胞信号传导中的重要作用而被研究。Leu对几种细胞的影响已被研究，但其对骨细胞和细胞增殖的作用尚不清楚。因此，本研究的目的是研究补充亮氨酸对MC3T3-E1系成骨前细胞增殖的影响。MC3T3-E1细胞保存在添加10%胎牛血清和1%抗有丝分裂抗生素的α培养基中。添加50 μ M的Leu处理48 h，相当于培养基中氨基酸增加了12.5%。用台盼蓝染色评价培养细胞的活力和增殖能力。为了确定与细胞增殖下降相关的机制，进行了细胞毒性、凋亡、氧化应激、炎症、自噬、衰老和DNA损伤的检测。结果表明，补充亮氨酸可通过与细胞坏死、凋亡、氧化应激、自噬或mTORC1通路抑制无关的机制降低40%的细胞增殖。另一方面，补充亮氨酸引起DNA损伤。综上所述，亮氨酸通过DNA损伤诱导细胞衰老，从而对骨细胞增殖产生负面影响。
Leucine (Leu) is an essential branched-chain amino acid, present in dairy products, which has been investigated for its important role in cell signaling. The effects of Leu on several kinds of cells have been studied, altough little is known on its action upon bone cells and cell proliferation. Thus, the aim of this study is to investigate the effects of Leu supplementation on the proliferation of pre-osteoblasts from MC3T3-E1 lineage. MC3T3-E1 cells were kept in Alpha medium supplemented with 10% fetal bovine serum and 1% antibiotic-antimitotic. Cells were treated during 48 h by adding 50 mu M of Leu, which corresponds to a 12.5% increase of the amino acid in the culture medium. The evaluation of viability and proliferation of cultured cells was performed using Trypan Blue dye. In order to identify the mechanisms related to the decreased cellular proliferation, assays were performed to assess cytotoxicity, apotosis, oxidative stress, inflammation, autophagy, senescence and DNA damage. Results showed that Leu supplementation decreased cell proliferation by 40% through mechanisms not related to cell necrosis, apoptosis, oxidative stress, autophagy or inhibition of the mTORC1 pathway. On the other hand, Leu supplementation caused DNA damage. In conclusion, Leu caused a negative impact on bone cell proliferation by inducing cell senescence through DNA damage.