Ang II-AT2R increases mesenchymal stem cell migration by signaling through the FAK and RhoA/Cdc42 pathways in vitro
Authors: Ai-Ran Liu
Jing-Yuan Xu
Li-Li Huang
Xiu-Ping Xu
Hai-Bo Qiu
Hong-Li He
Jian-Feng Xie
Shu-Ling Hu
Yi Yang
Ji-Bin Han
Journal: Stem Cell Research & Therapy (2017)
Discipline: MOLECULAR BIOLOGY & GENETICS
Keywords: AT1R; AT2R; Angiotensin II; Cell migration; F-actin
Affiliations: Department of Critical Care Medicine, Nanjing Zhongda Hospital, School of Medicine, Southeast University, Nanjing, 210009, People's Republic of China., Department of Critical Care Medicine, Affiliated Hospital of University of Electronic Science and Technology of China & Sichuan Provincial People's Hospital, Chengdu, 610072, People's Republic of China., Department of Critical Care Medicine, Nanjing Zhongda Hospital, School of Medicine, Southeast University, Nanjing, 210009, People's Republic of China. .

Abstract:  Background: Mesenchymal stem cells (MSCs) migrate via the bloodstream to sites of injury and are possibly attracted by inflammatory factors. As a proinflammatory mediator, angiotensin II (Ang II) reportedly enhances the migration of various cell types by signaling via the Ang II receptor in vitro. However, few studies have focused on the effects of Ang II on MSC migration and the underlying mechanisms. Methods: Human bone marrow MSCs migration was measured using wound healing and Boyden chamber migration assays after treatments with different concentrations of Ang II, an AT1R antagonist (Losartan), and/or an AT2R antagonist (PD-123319). To exclude the effect of proliferation on MSC migration, we measured MSC proliferation after stimulation with the same concentration of Ang II. Additionally, we employed the focal adhesion kinase (FAK) inhibitor PF-573228, RhoA inhibitor C3 transferase, Rac1 inhibitor NSC23766, or Cdc42 inhibitor ML141 to investigate the role of cell adhesion proteins and the Rho-GTPase protein family (RhoA, Rac1, and Cdc42) in Ang II-mediated MSC migration. Cell adhesion proteins (FAK, Talin, and Vinculin) were detected by western blot analysis. The Rho-GTPase family protein activities were assessed by G-LISA and F-actin levels, which reflect actin cytoskeletal organization, were detected by using immunofluorescence. Results: Human bone marrow MSCs constitutively expressed AT1R and AT2R. Additionally, Ang II increased MSC migration in an AT2R-dependent manner. Notably, Ang II-enhanced migration was not mediated by Ang II-mediated cell proliferation. Interestingly, Ang II-enhanced migration was mediated by FAK activation, which was critical for the formation of focal contacts, as evidenced by increased Talin and Vinculin expression. Moreover, RhoA and Cdc42 were activated by FAK to increase cytoskeletal organization, thus promoting cell contraction. Furthermore, FAK, Talin, and Vinculin activation and F-actin reorganization in response to Ang II were prevented by PD-123319 but not Losartan, indicating that FAK activation and F-actin reorganization were downstream of AT2R. Conclusions: These data indicate that Ang II-AT2R regulates human bone marrow MSC migration by signaling through the FAK and RhoA/Cdc42 pathways. This study provides insights into the mechanisms by which MSCs home to injury sites and will enable the rational design of targeted therapies to improve MSC engraftment. 

Retracted: Yes

PubPeer comments:
 Figures 2C and 6C appear to have an image which overlaps, after different cropping and rotation. Difficult to understand how this can be explained as an error during figure assembly. *** ![file] , 
 Figure 3 has some issues. *** ![file] *** Original ![file] , 
 Retracted [31 January 2022] . ----------------------- The Editors-in-Chief have retracted this article because overlap in cell images was identified in the published Figs. 2, 3 and 6. The authors provided the original files, but the data contained further cases of duplication. The Editor-in-Chief therefore no longer has confidence in the integrity of the data in this article. All authors agree to this retraction. ,