| First Author | Lima Correa B | Year | 2021 |
| Journal | Theranostics | Volume | 11 |
| Issue | 20 | Pages | 10114-10124 |
| PubMed ID | 34815807 | Mgi Jnum | J:346544 |
| Mgi Id | MGI:6828438 | Doi | 10.7150/thno.62304 |
| Citation | Lima Correa B, et al. (2021) Extracellular vesicles fail to trigger the generation of new cardiomyocytes in chronically infarcted hearts. Theranostics 11(20):10114-10124 |
| abstractText | Background: Extracellular vesicles (EV) mediate the therapeutic effects of stem cells but it is unclear whether this involves cardiac regeneration mediated by endogenous cardiomyocyte proliferation. Methods: Bi-transgenic MerCreMer/ZEG (n = 15/group) and Mosaic Analysis With Double Markers (MADM; n = 6/group) mouse models underwent permanent coronary artery ligation and received, 3 weeks later, 10 billion EV (from human iPS-derived cardiovascular progenitor cells [CPC]), or saline, injected percutaneously under echo guidance in the peri-infarcted myocardium. Endogenous cardiomyocyte proliferation was tracked by EdU labeling and biphoton microscopy. Other end points, including cardiac function (echocardiography and MRI), histology and transcriptomics were blindly assessed 4-6 weeks after injections. Results: There was no proliferation of cardiomyocytes in either transgenic mouse strains. Nevertheless, EV improved cardiac function in both models. In MerCreMer/ZEG mice, LVEF increased by 18.3 +/- 0.2% between baseline and the end-study time point in EV-treated hearts which contrasted with a decrease by 2.3 +/- 0.2% in the PBS group; MADM mice featured a similar pattern as intra-myocardial administration of EV improved LVEF by 13.3 +/- 0.16% from baseline whereas it decreased by 14.4 +/- 0.16% in the control PBS-injected group. This functional improvement was confirmed by MRI and associated with a reduction in infarct size, the decreased expression of several pro-fibrotic genes and an overexpression of the anti-fibrotic miRNA 133-a1 compared to controls. Experiments with an anti-miR133-a demonstrated that the cardio-reparative effects of EV were partly abrogated. Conclusions: EV-CPC do not trigger cardiomyocyte proliferation but still improve cardiac function by other mechanisms which may include the regulation of fibrosis. |
