MicroRNA-21 protects against cardiac hypoxia/reoxygenation injury by inhibiting excessive autophagy in H9c2 cells via the Akt/mTOR pathway.
MicroRNAs and autophagy play critical roles in cardiac hypoxia/reoxygenation (H/R)-induced injury. Here, we investigated the function of miR-21 in regulating autophagy and identified the potential molecular mechanisms involved. To determine the role of miR-21 in regulating autophagy, H9c2 cells were divided into the following six groups: control group, H/R group, (miR-21+ H/R) group, (miR-21-negative control + H/R) group, (BEZ235+ H/R) group and (miR-21+ BEZ235+ H/R) group. The cells underwent hypoxia for 1 hr and reoxygenation for 3 hrs. Cell count kit-8 was used to evaluate cell function and apoptosis was analysed by Western blotting. Western blotting and transmission electron microscopy were used to investigate autophagy. We found that miR-21 expression was down-regulated, and autophagy was remarkably increased in H9c2 cells during H/R injury. Overexpression of miR-21 with a miR-21 precursor significantly inhibited autophagic activity and decreased apoptosis, accompanied by the activation of the AKT/mTOR pathway. In addition, treatment with BEZ235, a novel dual Akt/mTOR inhibitor, resulted in a significant increase in autophagy and apoptosis. However, we found that miR-21-mediated inhibition of apoptosis and autophagy was partly independent of Akt/mTOR activation, as demonstrated in cells treated with both miR-21 and BEZ235. We showed that miR-21 could inhibit H/R-induced autophagy and apoptosis, which may be at least partially mediated by the Akt/mTOR signalling pathway.
Department of Cardiology, The Key Lab of Cardiovascular Disease of Wenzhou, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China.
Zhouqing
Z
Huang
Department of Cardiology, The Key Lab of Cardiovascular Disease of Wenzhou, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China.
Shengjie
S
Wu
Department of Cardiology, The Key Lab of Cardiovascular Disease of Wenzhou, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China.
Fanqi
F
Kong
Department of Cardiology, The Key Lab of Cardiovascular Disease of Wenzhou, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China.
Xueli
X
Cai
Department of Cardiology, The Key Lab of Cardiovascular Disease of Wenzhou, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China.
Bozhi
B
Ye
Department of Cardiology, The Key Lab of Cardiovascular Disease of Wenzhou, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China.
Peiren
P
Shan
Department of Cardiology, The Key Lab of Cardiovascular Disease of Wenzhou, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China.
Weijian
W
Huang
D000818:Animals; D017209:Apoptosis / Q000235:genetics; D001343:Autophagy / Q000235:genetics*; D015687:Cell Hypoxia / Q000235:genetics*; D002460:Cell Line; D015536:Down-Regulation / Q000235:genetics; D035683:MicroRNAs / Q000235:genetics*; D032383:Myocytes, Cardiac / Q000473:pathology*; D051057:Proto-Oncogene Proteins c-akt / Q000235:genetics*; D051381:Rats; D015398:Signal Transduction / Q000235:genetics; D058570:TOR Serine-Threonine Kinases / Q000235:genetics*
D035683:MicroRNAs; C546082:mirn21 microRNA, rat; C546845:mTOR protein, rat; D051057:Proto-Oncogene Proteins c-akt; D058570:TOR Serine-Threonine Kinases
H9c2 cells; apoptosis; autophagy; hypoxia/reoxygenation; miR-21
Biochim Biophys Acta. 2008 Jan;1784(1):150-8
17964232
Trends Mol Med. 2007 Nov;13(11):482-91
18029229
J Cardiovasc Transl Res. 2010 Jun;3(3):251-5
20560046
PLoS One. 2013 Oct 03;8(10):e75872
24098402
Eur J Pharmacol. 2015 Sep 5;762:1-10
26004523
Circ Res. 2007 Mar 30;100(6):914-22
17332429
Mol Med Rep. 2015 Jun;11(6):4678-84
25673156
Autophagy. 2008 May;4(4):402-3
18367869
Cell. 2005 Jan 14;120(1):15-20
15652477
Oncotarget. 2015 Apr 20;6(11):8474-90
25893379
Cell Death Differ. 2007 Jan;14(1):146-57
16645637
Nat Rev Cardiol. 2015 Mar;12(3):135-42
25511085
Autophagy. 2014 Jul;10 (7):1154-66
24915298
Autophagy. 2009 Aug;5(6):816-23
19535919
Arch Med Res. 2011 Jan;42(1):8-14
21376256
J Clin Invest. 2005 Oct;115(10):2679-88
16200202
Autophagy. 2012 Jun;8(6):873-82
22441107
Drug Resist Updat. 2008 Feb-Apr;11(1-2):32-50
18166498
Annu Rev Physiol. 1966;28:435-92
5322983
Biomed Res Int. 2014;2014:343542
24877083
PLoS One. 2012;7(10):e47449
23077620
Curr Drug Targets. 2013 Sep;14(10):1135-43
23834154
Oncotarget. 2015 Oct 6;6(30):28867-81
26311740
Glob Heart. 2012 Dec 1;7(4):331-342
23505617
N Engl J Med. 2015 Sep 10;373(11):1073-5
26321104
Am J Cancer Res. 2012;2(2):214-21
22485198
Circ Res. 2009 Jan 30;104(2):150-8
19179668
FEBS Lett. 2010 Apr 2;584(7):1287-95
20083114
Proc Natl Acad Sci U S A. 2008 Sep 2;105(35):13027-32
18723672
N Engl J Med. 2013 Feb 14;368(7):651-62
23406030
Autophagy. 2012 Apr;8(4):445-544
22966490
Apoptosis. 2009 Apr;14(4):376-91
19172397
Physiol Genomics. 2008 Apr 22;33(2):139-47
18303086
N Engl J Med. 2007 Sep 13;357(11):1121-35
17855673
Cardiovasc Res. 2012 May 1;94(2):197-205
22215722
Cell. 2008 Jan 11;132(1):27-42
18191218
J Biol Chem. 2009 Oct 23;284(43):29514-25
19706597
J Mol Cell Cardiol. 2006 Jun;40(6):846-52
16697404
Exp Cell Res. 2015 Oct 15;338(1):64-9
26302266
Br J Cancer. 2007;96 Suppl:R40-4
17393584
Front Mol Neurosci. 2011 Dec 02;4:51
22144946