miR-200a mediates protection of thymosin β-4 in cardiac microvascular endothelial cells as a novel mechanism under hypoxia-reoxygenation injury
Authors: Xiping Liu
Bo Yu
Xiaolong Zhu
Yang Li
Aolin Du
Journal: Journal of Cellular Biochemistry (2019)
Discipline: MOLECULAR BIOLOGY & GENETICS
Keywords: cardiac microvascular endothelial cells; myocardial ischemia/reperfusion injury; nuclear factor erythroid 2-related factor 2; thymosin β-4.
Affiliations: Department of Cardiology, The First Affiliated Hospital of China Medical University, Shenyang, Liaoning, PR China.

Abstract:  Thymosin β-4 (Tβ4) is a ubiquitous protein, which has been suggested to regulate multiple cell signal pathways and a variety of cellular functions. However, the role Tβ4 plays in the cardiac microvascular endothelial cells (CMECs) under myocardial ischemia/reperfusion injury is currently unknown. Here we investigated the effects of Tβ4 on hypoxia/reoxygenation (H/R) induced CMECs injury and its potential molecular mechanism. Cultured CMECs were positively identified by flow cytometry using antibody against CD31 and VWF/Factor VIII, which are constitutively expressed on the surface of CMECs. Then the reduced level of Tβ4 was detected in H/R-CMECs by a real-time quantitative polymerase chain reaction. To determine the effects of Tβ4 on H/R-CMECs, we transfected the overexpression or silence vector of Tβ4 into CMECs under H/R condition. Our results indicated that H/R treatment could reduce proliferation, increased apoptosis, adhesion, and reactive oxygen species (ROS) production in CMECs, which were attenuated by Tβ4 overexpression or aggravated by Tβ4 silencing, implying Tβ4 is able to promote CMECs against H/R-induced cell injury. Furthermore, the microRNA-200a (miR-200a) level was also increased by Tβ4 in H/R-CMECs or reduced by Tβ4 small interfering RNA. To investigated the mechanism of protective effects of Tβ4 on CMECs injury, the miR-200a inhibitor was transfected into H/R-CMECs. The results indicated that inhibition of miR-200a inversed the protection of Tβ4 on H/R-CMECs, specifically including cell proliferation, cell adhesion, cell apoptosis, and ROS production, as well as nuclear factor erythroid 2-related factor 2 (Nrf2) nuclear translocation. In conclusion, our results determined that Tβ4 attenuated H/R-induced CMECs injury by miR-200a-Nrf2 signaling. 

Retracted: No

PubPeer comments:
 Fig 1 (A):  Tu03b24 increased the cell proliferation of H Ru2010induced CMECs. A, Flow cytometry shows the **CD31 ... expression** in cultured CMECs.  Fig 5 (F):  Tu03b24 alleviated H Ru2010induced CMECs injury through the miRu2010200au2010Nrf2 pathway. H Ru2010CMECs were transfected with miRu2010200a inhibitor.... (F) **ROS production** was detected by flow cytometry. The red and black histograms in these quite different experiments appear to be identical apart from shifts along the horizontal axis. ![file] Fig 3 (A):  Effects of Tu03b24 on the ROS and adhesion molecules levels in H Ru2010induced CMECs. A, ROS production in Tu03b24 or Tu03b24 siRNA treated H Ru2010CMECs. The H R-Control and Tu03b24-siRNA histograms (black and purple) appear to be identical apart from a shift along the axis. ![file] , 
 Fig 2(A).  Tu03b24 inhibited the cell apoptosis of H Ru2010induced CMECs. A, Cell apoptosis was detected by flow cytometry. Similarities between two panels. ![file] , 
 Curiously, this paper was originally accepted in the same journal in 2017 with the DOI 10.1002 jcb.26381, [then retracted] , then evidently resubmitted. * The above article, from Journal of Cellular Biochemistry , u201cmiRu2010200a mediates protection of thymosin u03b24 in cardiac microvascular endothelial cells as a novel mechanism under hypoxiau2010reoxygenation injuryu201d by Yang Li, Xiaolong Zhu, Xiping Liu, Aolin Du, and Bo Yu published online on 31 August 2017 in Wiley Online Library , has been withdrawn by agreement between the journal Editor in Chief Gary S. Stein and John Wiley and Sons, Inc. The retraction has been agreed because the authors are not responding to requests to finalize their article for publication in the journal as the Version of Record. * ,