The role of cardiac tissue macrophages (cTMs) during pre- and postnatal developmental stages remains in many aspects unknown. We aimed to characterize cTM populations and their potential functions based on surface markers. Our in situ studies of immunostained cardiac tissue specimens of murine fetuses (from E11to E17) revealed that a significant number of embryonic cTMs (phenotyped by CD45, CD68, CD64, F4/80, CD11b, CD206, Lyve-1) resided mostly in the subepicardial space, not in the entire myocardial wall, as observed in adult individuals. cTMs accompanied newly developed blood and lymphatic vessels adhering to vessel walls by cellular processes. A subpopulation of CD68-positive cells was found to form accumulations in areas of massive apoptosis during the outflow tract remodeling and shortening. Flow cytometry analysis at E14 and E17 stages revealed newly defined three subpopulations:CD64^low, CD64^highCD206-and CD64^highCD206+. The levels of mRNA expression for genes related to regulation of angiogenesis (VEGFa, VEGFb, VEGFc, bFGF), lymphangiogenesis (VEGFc) and extracellular matrix (ECM) remodeling (MMP13, Arg1, Ym1/Chil3, Retlna/FIZZ1) differed among the selected populations and/or embryonic stages. Our results demonstrate a diversity of embryonic cTMs and their tissue-specific locations, suggesting their various potential roles in regulating angiogenesis, lymphangiogenesis and ECM remodeling.

在产前和产后发育阶段，心脏组织巨噬细胞（cTM）的作用在许多方面仍然未知。我们旨在基于表面标记物表征cTM种群及其潜在功能。我们对小鼠胎儿的免疫染色心脏组织标本（从E11至E17）进行的原位研究表明，大量胚胎cTM（表型由CD45，CD68，CD64，F4 / 80，CD11b，CD206，Lyve-1占据）如在成年个体中观察到的那样，心外膜下空间不在整个心肌壁中。cTM伴随着新发展的血液和淋巴管通过细胞过程粘附在血管壁上。发现CD68阳性细胞的亚群在流出道重塑和缩短期间在大量凋亡区域中形成积累。^低，CD64^高CD206-和CD64^高CD206 +。所选血管生成相关基因（VEGFa，VEGFb，VEGFc，bFGF），淋巴管生成（VEGFc）和细胞外基质（ECM）重塑（MMP13，Arg1，Ym1 / Chil3，Retlna / FIZZ1）的mRNA表达水平有所不同种群和/或胚胎阶段。我们的结果证明了胚胎cTM的多样性及其组织的特定位置，表明它们在调节血管生成，淋巴管生成和ECM重塑中具有多种潜在作用。