Luo Jun, Weaver Matthew S, Fitzgibbons Timothy P, Aouadi Myriam, Czech Michael P, Allen Margaret D
Matrix Biology Program, Benaroya Research Institute at Virginia Mason, Seattle, Washington, USA.
Cardiovascular Medicine, Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA.
Biores Open Access. 2020 Dec 2;9(1):258-268. doi: 10.1089/biores.2020.0037. eCollection 2020.
The myeloid cells infiltrating the heart early after acute myocardial infarction elaborate a secretome that largely orchestrates subsequent ventricular wall repair. Regulating this innate immune response could be a means to improve infarct healing. To pilot this concept, we utilized (β1,3-d-) glucan-encapsulated small interfering RNA (siRNA)-containing particles (GeRPs), targeting mononuclear phagocytes, delivered to mice as a one-time intramyocardial injection immediately after acute infarction. Findings demonstrated that cardiac macrophages phagocytosed GeRPs and had little systemic dissemination, thus providing a means to deliver local therapeutics. Acute infarcts were then injected with phosphate-buffered saline (PBS; vehicle) or GeRPs loaded with siRNA to , and excised hearts were examined at 3 and 7 days by quantitative polymerase chain reaction, flow cytometry, and histology. Compared with infarcted PBS-treated hearts, hearts with intrainfarct injections of siRNA-loaded GeRPs exhibited 69-89% reductions in transcripts for Map4k4 (mitogen-activated protein kinase kinase kinase kinase 4), interleukin (IL)-1β, and tumor necrosis factor α at 3 days. Expression of other factors relevant to matrix remodeling-monocyte chemoattractant protein-1 (MCP-1), matrix metalloproteinases, hyaluronan synthases, matricellular proteins, and profibrotic factors transforming growth factor beta (TGF-β), and connective tissue growth factor (CTGF)-were also decreased. Most effects peaked at 3 days, but, in some instances (Map4k4, IL-1β, TGF-β, CTGF, versican, and periostin), suppression persisted to 7 days. Thus, direct intramyocardial GeRP injection could serve as a novel and clinically translatable platform for RNA delivery to intracardiac macrophages for local and selective immunomodulation of the infarct microenvironment.
急性心肌梗死后早期浸润心脏的髓样细胞会分泌一种分泌组，该分泌组在很大程度上协调随后的心室壁修复。调节这种先天免疫反应可能是改善梗死愈合的一种方法。为了验证这一概念，我们使用了（β1,3 - d -）葡聚糖包裹的含小干扰RNA（siRNA）的颗粒（GeRPs），其靶向单核吞噬细胞，在急性梗死后立即一次性心肌内注射到小鼠体内。研究结果表明，心脏巨噬细胞吞噬了GeRPs且很少发生全身扩散，从而提供了一种递送局部治疗药物的方法。然后，对急性梗死灶注射磷酸盐缓冲盐水（PBS；载体）或装载有针对Map4k4（丝裂原活化蛋白激酶激酶激酶激酶4）、白细胞介素（IL）-1β和肿瘤坏死因子α的siRNA的GeRPs，并在3天和7天时通过定量聚合酶链反应、流式细胞术和组织学检查切除的心脏。与梗死灶注射PBS处理的心脏相比，梗死灶内注射装载有siRNA的GeRPs的心脏在3天时Map4k4、IL -1β和肿瘤坏死因子α的转录本减少了69% - 89%。与基质重塑相关的其他因子——单核细胞趋化蛋白-1（MCP -1）、基质金属蛋白酶、透明质酸合成酶、基质细胞蛋白以及促纤维化因子转化生长因子β（TGF -β）和结缔组织生长因子（CTGF）的表达也降低了。大多数效应在3天时达到峰值，但在某些情况下（Map4k4、IL -1β、TGF -β、CTGF、多功能蛋白聚糖和骨膜蛋白），抑制作用持续到7天。因此，直接心肌内注射GeRP可作为一种新颖且可临床转化的平台，用于将RNA递送至心内巨噬细胞，以对梗死微环境进行局部和选择性免疫调节。
