title: Cardiac resident macrophages are involved in hypoxia‑induced postnatal cardiomyocyte proliferation.
abstract: Induction of cardiomyocyte proliferation, the most promising approach to reverse myocardial attrition, has been gaining importance as a therapy for cardiovascular disease. Hypoxia and macrophages were previously independently reported to promote cardiomyocyte proliferation in mice. However, whether hypoxia promotes cardiomyocyte proliferation in humans, and the association between hypoxia and macrophages in cardiomyocyte proliferation, have not to the best of our knowledge been previously investigated. The present study investigated the cardiomyocyte proliferation in 22 acyanotic and 29 cyanotic patients. Cardiomyocyte proliferation in a hypoxic mouse model (15% O2) was subsequently performed and the macrophage subsets were analyzed. A C‑C chemokine receptor type 2 (CCR2) inhibitor was used to increase the number of resident macrophages in order to investigate the effect of macrophages on cardiomyocyte proliferation. The results demonstrated that cardiomyocyte proliferation in the cyanotic infant group was significantly increased compared with the acyanotic infant group and the hypoxia‑treated C57BL/6J neonates confirmed the hypoxia‑induced cardiomyocyte proliferation. However, hypoxia did not induce the proliferation of isolated cardiomyocytes. Notably, hypoxia treatment increased the number of cardiac resident macrophages in neonate hearts. Furthermore, increasing the number of resident macrophages significantly enhanced cardiomyocyte proliferation. In conclusion, postnatal hypoxia promoted cardiomyocyte proliferation in humans and animals, and cardiac resident macrophages may be involved in this process. Therefore, this novel mechanism may provide a promising strategy for cardiovascular disease treatment.
authors.affiliation: Institute of Cardiovascular Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, P.R. China.
authors.forename: Bo
authors.initials: B
authors.lastname: Liu
authors.affiliation: Institute of Cardiovascular Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, P.R. China.
authors.forename: Hua-Gang
authors.initials: HG
authors.lastname: Zhang
authors.affiliation: Institute of Cardiovascular Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, P.R. China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Institute of Cardiovascular Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, P.R. China.
authors.forename: Yun-Han
authors.initials: YH
authors.lastname: Jiang
authors.affiliation: Institute of Cardiovascular Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, P.R. China.
authors.forename: Gui-Ping
authors.initials: GP
authors.lastname: Luo
authors.affiliation: Institute of Cardiovascular Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, P.R. China.
authors.forename: Fu-Qin
authors.initials: FQ
authors.lastname: Tang
authors.affiliation: Institute of Cardiovascular Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, P.R. China.
authors.forename: Zhao
authors.initials: Z
authors.lastname: Jian
authors.affiliation: Institute of Cardiovascular Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, P.R. China.
authors.forename: Ying-Bin
authors.initials: YB
authors.lastname: Xiao
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D000831:Animals, Newborn; D015415:Biomarkers; D049109:Cell Proliferation; D002478:Cells, Cultured; D002648:Child; D002675:Child, Preschool; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D000860:Hypoxia / Q000378:metabolism*; D007223:Infant; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology*; D008297:Male; D051379:Mice; D009206:Myocardium / Q000378:metabolism* / Q000473:pathology*; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000378:metabolism*; D054390:Receptors, CCR2 / Q000037:antagonists & inhibitors; D055815:Young Adult
chemical_list: D015415:Biomarkers; D054390:Receptors, CCR2