MALAT1 in Human Adipose Stem Cells Modulates Survival and Alternative Splicing of PKCδII in HT22 Cells
MALAT1 in Human Adipose Stem Cells Modulates Survival and Alternative Splicing of PKCδII in HT22 Cells
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DOI：
10.1210/en.2016-1819
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发表时间：
2017-01-01
期刊：
影响因子：
4.8
通讯作者：
Patel, Niketa A.
中科院分区：
文献类型：
--
作者：
El Bassit, Ghattas;Patel, Rekha S.;Patel, Niketa A.
脑损伤可能由创伤引起，也可能发生在中风和神经退行性疾病中。由于中枢神经系统不能有效再生，因此使用干细胞来促进神经元存活具有极大的兴趣。这里感兴趣的是人类脂肪源性干细胞（hASC），它分泌的因子可以增强损伤部位神经元的再生和存活。我们评估了hASC分泌体对损伤后永生化小鼠海马细胞系（HT 22）的影响。蛋白激酶C δ（PKC δ）激活神经元的存活和增殖，并与记忆有关。我们以前表明，选择性剪接的PKC δ II通过B细胞淋巴瘤2 Bcl 2在HT 22神经元细胞中增强神经元存活。我们的结果表明，损伤后，用来自hASC分泌体的外泌体治疗增加了HT22细胞中PKC δ II的表达，并增加了神经元的存活和增殖。具体来说，我们证明了转移相关肺腺癌转录本1（MALAT1），一种包含在hASC外泌体中的长非编码RNA介导PKC δ II剪接，从而增加神经元存活。使用反义寡核苷酸MALAT1和RNA免疫沉淀试验，我们证明MALAT1招募剪接因子富含丝氨酸精氨酸的剪接因子2（SRSF2），以促进选择性剪接的PKC δ II。最后，我们评估了胰岛素在增强hASC介导的神经元存活中的作用，并证明胰岛素治疗显著增加了MALAT1和SRSF2的关联，并显著增加了HT 22细胞损伤后的存活和增殖。总之，我们证明了hASC外泌体在增加神经元存活中的作用机制。hASC外泌体促进伤口愈合的这种作用可以通过在HT22细胞中的胰岛素处理进一步增强。
Brain injury may be caused by trauma or may occur in stroke and neurodegenerative diseases. Because the central nervous system is unable to regenerate efficiently, there is utmost interest in the use of stem cells to promote neuronal survival. Of interest here are human adipose-derived stem cells (hASCs), which secrete factors that enhance regeneration and survival of neurons in sites of injury. We evaluated the effect of hASC secretome on immortalized mouse hippocampal cell line (HT22) after injury. Protein kinase C delta (PKC delta) activates survival and proliferation in neurons and is implicated in memory. We previously showed that alternatively spliced PKC delta II enhances neuronal survival via B-cell lymphoma 2 Bcl2 in HT22 neuronal cells. Our results demonstrate that following injury, treatment with exosomes from the hASC secretome increases expression of PKC delta II in HT22 cells and increases neuronal survival and proliferation. Specifically, we demonstrate that metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), a long noncoding RNA contained in the hASC exosomes mediates PKC delta II splicing, thereby increasing neuronal survival. Using antisense oligonucleotides for MALAT1 and RNA immunoprecipitation assays, we demonstrate that MALAT1 recruits splice factor serine-arginine-rich splice factor 2 (SRSF2) to promote alternative splicing of PKC delta II. Finally, we evaluated the role of insulin in enhancing hASC-mediated neuronal survival and demonstrated that insulin treatment dramatically increases the association of MALAT1 and SRSF2 and substantially increases survival and proliferation after injury in HT22 cells. In conclusion, we demonstrate the mechanism of action of hASC exosomes in increasing neuronal survival. This effect of hASC exosomes to promote wound healing can be further enhanced by insulin treatment in HT22 cells.