Exosomal miR-7 Mediates Bystander Autophagy in Lung after Focal Brain Irradiation in Mice

被引：72

作者：

Cai, Shang ^{[1
,2
]}

Shi, Geng-Sheng ^{[3
]}

Cheng, Hui-Ying ^{[2
,4
]}

Zeng, Ya-Nan ^{[2
,4
]}

Li, Gen ^{[2
,4
]}

Zhang, Meng ^{[2
,4
]}

Song, Man ^{[2
,4
]}

Zhou, Ping-Kun ^{[2
]}

Tian, Ye ^{[1
,2
]}

Cui, Feng-Mei ^{[2
,4
]}

Chen, Qiu ^{[2
,4
]}

机构：

[1] Soochow Univ, Affiliated Hosp 2, Dept Radiotherapy & Oncol, Suzhou 215004, Peoples R China

[2] Jiangsu Higher Educ Inst, Collaborat Innovat Ctr Radiat Med, Suzhou 215123, Peoples R China

[3] Shandong Acad Med Sci, Shandong Acad Occupat Hlth & Occupat Med, Jinan 250062, Shandong, Peoples R China

[4] Soochow Univ, Dept Radiat Med, Med Coll, Sch Radiat Med & Protect, Suzhou 215123, Peoples R China

来源：

INTERNATIONAL JOURNAL OF BIOLOGICAL SCIENCES | 2017年 / 13卷 / 10期

关键词：

exosome; miR-7; radiation; radiation induced bystander effect ( RIBE); autophagy; IONIZING-RADIATION; CANCER; CELLS; EXPRESSION; MICRORNAS; MIRNA; BIOGENESIS; SECRETION; MECHANISM; DELIVERY;

D O I：

10.7150/ijbs.18890

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

070307 [化学生物学]; 071010 [生物化学与分子生物学];

摘要：

This study investigated whether exosomal microRNA-7 (miR-7) mediates lung bystander autophagy after focal brain irradiation in mice. After 10 Gy or sham irradiation of mice brains, lung tissues were extracted for the detection of autophagy markers by immunohistochemistry, western blotting, and quantitative real-time reverse transcription PCR (qRT-PCR), meanwhile the brains were dissociated, the neuron/astrocyte/microglia/oligodendrocyte were isolated, and the miR-7 expression in each population were detected, respectively. A dual-luciferase reporter assay was developed to identify whether Bcl-2 is a target gene of miR-7. After 10 Gy or sham irradiation of astrocytes, exosomes were extracted, stained with Dil (1,1'-Dioctadecyl-3,3,3', 3'-Tetramethylindocarbocyanine Perchlorate), and added into non-irradiated astrocytes. Meanwhile, Dil-stained exosomes released from 10 Gy or sham irradiated astrocytes were injected into LC3B-GFP mice via the tail vein. Lung tissues were then extracted for western blotting and qRT-PCR. Irradiation of mouse brains increased the LC3B-II/I ratio, Beclin-1 and miR-7 levels, while decreased the Bcl-2 level in non-irradiated lung tissue. Interestingly, brain irradiation remarkably increased the miR-7 expression in astrocyte and oligodendrocyte. MiR-7 significantly inhibited the luciferase activity of the wild-type Bcl-2-3'-untranslated regions (UTR) reporter vector, but not that of the Bcl-2-3'-UTR mutant vector, indicating that Bcl-2 is directly targeted by miR-7. In in vitro study, the addition of irradiated astrocyte-secreted exosomes increased the LC3B-II/I ratio, Beclin-1 and miR-7 levels, while decreased the Bcl-2 level in non-irradiated astrocytes. Further, the injection of irradiated astrocyte-secreted exosomes through the tail vein increased the lung LC3B-II/I ratio, Beclin-1 and miR-7 level, but decreased the Bcl-2 level in vivo. We concluded that exosomal miR-7 targets Bcl-2 to mediate distant bystander autophagy in the lungs after brain irradiation.

引用

页码：1287 / 1296

页数：10

共 32 条

[1]

The non-targeted effects of radiation are perpetuated by exosomes [J].