Exosomes derived from mesenchymal stem cells attenuate the progression of atherosclerosis in ApoE-/- mice via miR-let7 mediated infiltration and polarization of M2 macrophage.

Atherosclerosis is a chronic inflammatory disease of the vasculature. Exosomes derived from mesenchymal stem cells (MSCs) exert immunomodulatory and immunosuppressive effects; however, the MSCs-exosomes administration on atherosclerosis was unknown. Here, our ApoE-/- mice were fed a high-fat diet and received intravenous injections of exosomes from MSCs for 12 weeks. After tail-vein injection, MSCs-exosomes were capable of migrating to atherosclerotic plaque and selectively taking up residence near macrophages. MSCs-exosomes treatment decreased the atherosclerotic plaque area of ApoE-/- mice and greatly reduced the infiltration of macrophages in the plaque, associating induced macrophage polarization towards M2. In vitro, MSCs-exosomes treatment markedly inhibited LPS-induced M1 markers expression, while increased M2 markers expression in macrophages. Moreover, miR-let7 family was found to be highly enriched in MSCs-exosomes. Endogenous miR-let7 expression was found in the aortic root of ApoE-/- mice, and MSCs-exosomes treatment further up-regulated miR-let7 levels. In addition, inhibition of miR-let7 in U937 cells significantly inhibited the migration and M2 polarization via IGF2BP1 and HMGA2 pathway respectively in vitro. Our study demonstrates that MSCs-exosomes ameliorated atherosclerosis in ApoE-/- and promoted M2 macrophage polarization in the plaque through miR-let7/HMGA2/NF-κB pathway. In addition, MSCs-exosomes suppressed macrophage infiltration via miR-let7/IGF2BP1/PTEN pathway in the plaque. This finding extends our knowledge on MSCs-exosomes affect inflammation in atherosclerosis plaque and provides a potential method to prevent the atherosclerosis. Exosomes from MSCs hold promise as therapeutic agents to reduce the residual risk of coronary artery diseases.

The Relationship between Intelligent Image Simulation and Recognition Technology and the Health Literacy and Quality of Life of the Elderly.

In order to explore the relationship between intelligent image recognition technology and the mentality and quality of life of the elderly, this paper combines intelligent image simulation technology to identify the behavior of the elderly, protect the safety of the elderly, and provide timely feedback on the adverse conditions of the elderly. Moreover, this paper improves the traditional intelligent image recognition algorithm, verifies the research method of this paper through experimental research, and puts forward corresponding suggestions. Through investigation and research, we can see that the level of health literacy of elderly patients with chronic diseases is low. Therefore, in the future health education, we should strengthen health education for elderly patients with chronic diseases, use different mass media to propagate health knowledge, and promote the formation of healthy lifestyles and behaviors for elderly patients with chronic diseases. At the same time, the experiment also verified that the intelligent image recognition technology proposed in this paper has a positive effect in improving the mentality and quality of life of the elderly.