Fibroblast transdifferentiation promotes conversion of M1 macrophages and replenishment of cardiac resident macrophages following cardiac injury in mice
Authors: Shiqing Zhang
Hongxiang Lu
Zhaoliang Su
Rong Chen
Huaxi Xu
Yu Tian
Prince Amoah Barnie
Subrata Chakrabarti
Journal: European Journal of Immunology (2020)
Discipline: IMMUNOLOGY
Keywords: Cardiac injury; Cardiac resident macrophage; Inflammation; Leptin; Transdifferentiation.
Affiliations: International Genome CenterJiangsu University Zhenjiang China, Department of ImmunologyJiangsu University Zhenjiang China, Pathology and Laboratory MedicineWestern University London Ontario Canada

Abstract:  Resident cardiac macrophages play important roles in homeostasis, maintenance of cardiac function, and tissue repair. After cardiac injury, monocytes infiltrate the tissue, undergo phenotypic and functional changes, and are involved in inflammatory injury and functional remodelling. However, the fate of cardiac infiltrating/polarized macrophages and the relationship between these cells and resident cardiac macrophage replenishment following injury remain unclear. Our results showed that angiotensin II induces cardiac fibroblast transdifferentiation into cardiac myofibroblasts (MFBs). In cocultures with MFBs and murine macrophages, the MFBs promoted macrophage polarization to M1 phenotype, followed by selective apoptosis, which was associated with TNF/TNFR1 axis and independent of NO production. Surprisingly, after 36 h of coculture, the surviving macrophages were converted to M2 phenotype and settled in heart, which was dependent on leptin produced by MFBs or polarized macrophages via the PI3K or Akt pathway. CCR2+ CD45.2+ cells adoptively transferred into CD45.1+ mice with viral myocarditis, differentiated into CD45.2+ CCR2+ CX3CR1+ M2 cells during the resolution of inflammation and settled within the heart. Our data highlight a novel mechanism related to the renewal or replenishment of cardiac resident macrophages following cardiac injury; and suggest that transdifferentiation of cardiac fibroblasts may promote the resolution of inflammation. 

Retracted: No

PubPeer comments:
 Fig. 2A. Numerous overlaps exist between MCF and MFB. I only marked a few. Were these 2 plots from the same experiment? ![file] , 
 #1 Dear Tulipa: Thanks for your attention to our works. we had checked the primary records. the data are true. we can give the primary data. ![file] best wishes zhaoliang SU , 
 #1 Is it possible that the MCF and MFB panels are from a single experimental run, where the two cell types were separated digitally by plotting the data twice with different gate settings? And that some overlap remained between those settings, allowing some points (cells) to appear in both panels? Here is my attempt to dramatise the overlap, using a color-coded superimposition of the two panels. Red points (and text) are present in both panels. White points are unique to MFB. Purple points are unique to MCF. The lower quadrants contain a lot of red points; most of the white points are in the upper quadrants. ![file] , 
 #2 Thank you Dr. Su for responding to my comment. However, I don t see my question answered. My question was  Were these 2 plots from the same experiment? Expecting the answer should either be yes or no. You attached a set of plots without annotating what they are for. I took a look and they look to me not the same as the one published in your paper. Can you please explain a bit? ![file] , 
 #4 Dear Tulipa Firstly, I am so sorry for the delay, however, I donu2019t know that it is my computeru2019s problem or not, we canu2019t answer the comments, because the webpage always showed errors. The same phenomena also occurred at other authors. We confirmed that the two images are not from the same experiment. In fact, the data were repeated at cell line and primary cells, the conclusion is reliable and definite. To demonstrated that the data are true, we gave the raw data (color is raw data and black is analyzed from raw data). Please see them, however, we want to say the previously gating not being saved so the present analyzed data are obtained from re-gating. Therefore, the results we present now may not be exactly the same as those in the article. About your concern, why the two images have same blots in paper, actually, we also donu2019t know why. Since you concern it, we analyzed every possibility, we also suspected whether the results are really like this or the action caused: copies of template during the raw data analysis. You have a lot of experience about image process, if you know why, please let us know to avoid such things happening in the future. Best wishes Hongxiang Lu and Zhaoliang Su ![](http: )![file] ![file] , 
 Dear Zhaoliang Su, Maybe you can upload the original FSC files for review and post the link for download? Same for the other publication with similar problems: https: pubpeer.com publications 0824FD7EACAA32B79878A18C1AEC93#5 Thanks! , 
 Readers should reassess the reliability of this paper as its bibliography includes **several questioned references** that are likely to be unreliable. So far, the following have been spotted: | Questioned Reference Cited | Details | | --- | --- | | [10.1038 srep21884](7E10411B3665A2770A3B91CE3719C2) retracted | [2016] _Scientific Reports_: RETRACTED ARTICLE: HMGB1 Facilitated Macrophage Reprogramming towards a Proinflammatory M1-like Phenotype in Experimental Autoimmune Myocarditis Development. Zhaoliang Su u2022 Pan Zhang u2022 Ying Yu u2022 Hongxiang Lu u2022 Yanfang Liu u2022 Ping Ni u2022 Xiaolian Su u2022 Dan Wang u2022 Yueqin Liu u2022 Jia Wang u2022 Huiling Shen u2022 Wenlin Xu u2022 Huaxi Xu | | [10.1002 eji.201141879](0824FD7EACAA32B79878A18C1AEC93) | [2011] _European Journal of Immunology_: HMGB1 blockade attenuates experimental autoimmune myocarditis and suppresses Th17u2010cell expansion. Zhaoliang Su u2022 Caixia Sun u2022 Chenglin Zhou u2022 Yanfang Liu u2022 Haitao Zhu u2022 Siamak Sandoghchian u2022 Dong Zheng u2022 Tianqing Peng u2022 Yu Zhang u2022 Zhijun Jiao u2022 Shengjun Wang u2022 Huaxi Xu | According to [Dimensions] , this article has been [cited 5 times] . Flagged by the [_Problematic Paper Screener_] , [Feet of Clay] Detector. ,