Mikhailov Andrey, Sankai Yoshiyuki
Center for Cybernics Research, University of Tsukuba, Tsukuba, Japan.
BMC Res Notes. 2019 Jul 19;12(1):440. doi: 10.1186/s13104-019-4480-0.
Cell survival in critical post-transplantation period is challenged by inflammation, lack of vascularization, and insufficient cell attachment anchoring. Temporally blocking cell death may increase cell survival, but it is important to possess no risks of sustained cell death signal blocking and possible malignant transformations. Regarding apoptotic cell death, multi-micromolar overloading the cell with competitive caspase substrates delays the effects of actual downstream enzyme activation processing. Later, when introduced substrate is consumed, and the caspase activation stimuli may still be present, the apoptotic cell death can proceed normally.
Here we studied several synthetic peptides comprising from effector caspase activational cleavage sequences fused with various internalization motifs. Designed peptides showed rapid and efficient internalization into cultured neuroblast cells comparing to non-fused cleavage sequences as measured by cytofluorimetry and confirmed by mass spectrometry. Pretreatment with selected peptides protected the cells from several apoptogenic stimuli in vitro, as well as improved survival of syngeneic immortalized Schwann cells during transplantation in vivo.
移植后关键时期的细胞存活受到炎症、血管化不足和细胞附着锚定不充分的挑战。暂时阻断细胞死亡可能会提高细胞存活率，但避免持续阻断细胞死亡信号和可能发生恶性转化的风险很重要。关于凋亡性细胞死亡，用竞争性半胱天冬酶底物使细胞多微摩尔超载会延迟实际下游酶激活过程的效应。之后，当引入的底物被消耗，而半胱天冬酶激活刺激可能仍然存在时，凋亡性细胞死亡可正常进行。
在此我们研究了几种由效应半胱天冬酶激活切割序列与各种内化基序融合而成的合成肽。通过细胞荧光测定法测量并经质谱法确认，与未融合的切割序列相比，设计的肽显示出能快速高效地内化到培养的神经母细胞中。用选定的肽进行预处理可在体外保护细胞免受多种凋亡诱导刺激，并提高同基因永生化雪旺细胞在体内移植期间的存活率。
