Small Extracellular Vesicles From Infarcted and Failing Heart Accelerate Tumor Growth. Circulation BACKGROUND:Myocardial infarction (MI) and heart failure are associated with an increased incidence of cancer. However, the mechanism is complex and unclear. Here, we aimed to test our hypothesis that cardiac small extracellular vesicles (sEVs), particularly cardiac mesenchymal stromal cell-derived sEVs (cMSC-sEVs), contribute to the link between post-MI left ventricular dysfunction (LVD) and cancer. METHODS:We purified and characterized sEVs from post-MI hearts and cultured cMSCs. Then, we analyzed cMSC-EV cargo and proneoplastic effects on several lines of cancer cells, macrophages, and endothelial cells. Next, we modeled heterotopic and orthotopic lung and breast cancer tumors in mice with post-MI LVD. We transferred cMSC-sEVs to assess sEV biodistribution and its effect on tumor growth. Finally, we tested the effects of sEV depletion and spironolactone treatment on cMSC-EV release and tumor growth. RESULTS:Post-MI hearts, particularly cMSCs, produced more sEVs with proneoplastic cargo than nonfailing hearts did. Proteomic analysis revealed unique protein profiles and higher quantities of tumor-promoting cytokines, proteins, and microRNAs in cMSC-sEVs from post-MI hearts. The proneoplastic effects of cMSC-sEVs varied with different types of cancer, with lung and colon cancers being more affected than melanoma and breast cancer cell lines. Post-MI cMSC-sEVs also activated resting macrophages into proangiogenic and protumorigenic states in vitro. At 28-day follow-up, mice with post-MI LVD developed larger heterotopic and orthotopic lung tumors than did sham-MI mice. Adoptive transfer of cMSC-sEVs from post-MI hearts accelerated the growth of heterotopic and orthotopic lung tumors, and biodistribution analysis revealed accumulating cMSC-sEVs in tumor cells along with accelerated tumor cell proliferation. sEV depletion reduced the tumor-promoting effects of MI, and adoptive transfer of cMSC-sEVs from post-MI hearts partially restored these effects. Finally, spironolactone treatment reduced the number of cMSC-sEVs and suppressed tumor growth during post-MI LVD. CONCLUSIONS:Cardiac sEVs, specifically cMSC-sEVs from post-MI hearts, carry multiple protumorigenic factors. Uptake of cMSC-sEVs by cancer cells accelerates tumor growth. Treatment with spironolactone significantly reduces accelerated tumor growth after MI. Our results provide new insight into the mechanism connecting post-MI LVD to cancer and propose a translational option to mitigate this deadly association. 10.1161/CIRCULATIONAHA.123.066911

A Network of Macrophages Supports Mitochondrial Homeostasis in the Heart. Nicolás-Ávila José A,Lechuga-Vieco Ana V,Esteban-Martínez Lorena,Sánchez-Díaz María,Díaz-García Elena,Santiago Demetrio J,Rubio-Ponce Andrea,Li Jackson LiangYao,Balachander Akhila,Quintana Juan A,Martínez-de-Mena Raquel,Castejón-Vega Beatriz,Pun-García Andrés,Través Paqui G,Bonzón-Kulichenko Elena,García-Marqués Fernando,Cussó Lorena,A-González Noelia,González-Guerra Andrés,Roche-Molina Marta,Martin-Salamanca Sandra,Crainiciuc Georgiana,Guzmán Gabriela,Larrazabal Jagoba,Herrero-Galán Elías,Alegre-Cebollada Jorge,Lemke Greg,Rothlin Carla V,Jimenez-Borreguero Luis Jesús,Reyes Guillermo,Castrillo Antonio,Desco Manuel,Muñoz-Cánoves Pura,Ibáñez Borja,Torres Miguel,Ng Lai Guan,Priori Silvia G,Bueno Héctor,Vázquez Jesús,Cordero Mario D,Bernal Juan A,Enríquez José A,Hidalgo Andrés Cell Cardiomyocytes are subjected to the intense mechanical stress and metabolic demands of the beating heart. It is unclear whether these cells, which are long-lived and rarely renew, manage to preserve homeostasis on their own. While analyzing macrophages lodged within the healthy myocardium, we discovered that they actively took up material, including mitochondria, derived from cardiomyocytes. Cardiomyocytes ejected dysfunctional mitochondria and other cargo in dedicated membranous particles reminiscent of neural exophers, through a process driven by the cardiomyocyte's autophagy machinery that was enhanced during cardiac stress. Depletion of cardiac macrophages or deficiency in the phagocytic receptor Mertk resulted in defective elimination of mitochondria from the myocardial tissue, activation of the inflammasome, impaired autophagy, accumulation of anomalous mitochondria in cardiomyocytes, metabolic alterations, and ventricular dysfunction. Thus, we identify an immune-parenchymal pair in the murine heart that enables transfer of unfit material to preserve metabolic stability and organ function. VIDEO ABSTRACT. 10.1016/j.cell.2020.08.031

M2 Macrophage-Derived sEV Regulate Pro-Inflammatory CCR2 Macrophage Subpopulations to Favor Post-AMI Cardiac Repair. Advanced science (Weinheim, Baden-Wurttemberg, Germany) Tissue-resident cardiac macrophage subsets mediate cardiac tissue inflammation and repair after acute myocardial infarction (AMI). CC chemokine receptor 2 (CCR2)-expressing macrophages have phenotypical similarities to M1-polarized macrophages, are pro-inflammatory, and recruit CCR2 circulating monocytes to infarcted myocardium. Small extracellular vesicles (sEV) from CCR2 macrophages, which phenotypically resemble M2-polarized macrophages, promote anti-inflammatory activity and cardiac repair. Here, the authors harvested M2 macrophage-derived sEV (M2 ) from M2-polarized bone-marrow-derived macrophages for intramyocardial injection and recapitulation of sEV-mediated anti-inflammatory activity in ischemic-reperfusion (I/R) injured hearts. Rats and pigs received sham surgery; I/R without treatment; or I/R with autologous M2 treatment. M2 rescued cardiac function and attenuated injury markers, infarct size, and scar size. M2 inhibited CCR2 macrophage numbers, reduced monocyte-derived CCR2 macrophage recruitment to infarct sites, induced M1-to-M2 macrophage switching and promoted neovascularization. Analysis of M2 microRNA content revealed abundant miR-181b-5p, which regulated macrophage glucose uptake, glycolysis, and mitigated mitochondrial reactive oxygen species generation. Functional blockade of miR-181b-5p is detrimental to beneficial M2 actions and resulted in failure to inhibit CCR2 macrophage numbers and infarct size. Taken together, this investigation showed that M2 rescued myocardial function, improved myocardial repair, and regulated CCR2 macrophages via miR-181b-5p-dependent mechanisms, indicating an option for cell-free therapy for AMI. 10.1002/advs.202202964

Engineered small extracellular vesicle-mediated NOX4 siRNA delivery for targeted therapy of cardiac hypertrophy. Journal of extracellular vesicles Small-interfering RNA (siRNA) therapy is considered a powerful therapeutic strategy for treating cardiac hypertrophy, an important risk factor for subsequent cardiac morbidity and mortality. However, the lack of safe and efficient in vivo delivery of siRNAs is a major challenge for broadening its clinical applications. Small extracellular vesicles (sEVs) are a promising delivery system for siRNAs but have limited cell/tissue-specific targeting ability. In this study, a new generation of heart-targeting sEVs (CEVs) has been developed by conjugating cardiac-targeting peptide (CTP) to human peripheral blood-derived sEVs (PB-EVs), using a simple, rapid and scalable method based on bio-orthogonal copper-free click chemistry. The experimental results show that CEVs have typical sEVs properties and excellent heart-targeting ability. Furthermore, to treat cardiac hypertrophy, CEVs are loaded with NADPH Oxidase 4 (NOX4) siRNA (siNOX4). Consequently, CEVs@siNOX4 treatment enhances the in vitro anti-hypertrophic effects by CEVs with siRNA protection and heart-targeting ability. In addition, the intravenous injection of CEVs@siNOX4 into angiotensin II (Ang II)-treated mice significantly improves cardiac function and reduces fibrosis and cardiomyocyte cross-sectional area, with limited side effects. In conclusion, the utilization of CEVs represents an efficient strategy for heart-targeted delivery of therapeutic siRNAs and holds great promise for the treatment of cardiac hypertrophy. 10.1002/jev2.12371

Injury minimization after myocardial infarction: focus on extracellular vesicles. European heart journal Despite improvements in clinical outcomes following acute myocardial infarction, mortality remains high, especially in patients with severely reduced left ventricular ejection fraction (LVEF <30%), emphasizing the need for effective cardioprotective strategies adjunctive to recanalization. Traditional cell therapy has shown equivocal success, shifting the focus to innovative cardioactive biologicals and cell mimetic therapies, particularly extracellular vesicles (EVs). EVs, as carriers of non-coding RNAs and other essential biomolecules, influence neighbouring and remote cell function in a paracrine manner. Compared to cell therapy, EVs possess several clinically advantageous traits, including stability, ease of storage (enabling off-the-shelf clinical readiness), and decreased immunogenicity. Allogeneic EVs from mesenchymal and/or cardiac stromal progenitor cells demonstrate safety and potential efficacy in preclinical settings. This review delves into the translational potential of EV-based therapeutic approaches, specifically highlighting findings from large-animal studies, and offers a synopsis of ongoing early-stage clinical trials in this domain. 10.1093/eurheartj/ehae089