Sonodynamic Therapy Promotes Efferocytosis via CD47 Down-Regulation in Advanced Atherosclerotic Plaque.

Atherosclerotic cerebrocardiovascular disease is the major cause of acute ischemic diseases in humans. Impaired efferocytosis contributes to the progression of atherosclerosis. Pathological and apoptotic cells fail to undergo effective phagocytic clearance, leading to increased inflammation and necrotic core formation. Previously, we reported that 5-aminolevulinic acid-mediated sonodynamic therapy (SDT) promotes apoptotic cell efferocytosis via ATP release in atherosclerotic plaques. However, the exact signaling molecule involved in this process is still unknown. In the present study, sinoporphyrin sodium-mediated SDT (DVDMS-SDT) was applied to balloon-denuded rabbits in vivo to observe changes in the composition of atherosclerotic lesions. Cultured human THP-1-derived and mouse peritoneal macrophage-derived foam cells were used for in vitro mechanistic studies. Three days after DVDMS-SDT treatment, macrophage efferocytosis was significantly enhanced whereas local inflammation was attenuated in rabbit atherosclerotic lesions. At days 7 and 28, the histopathological analysis showed that DVDMS-SDT inhibited the progression of atherosclerosis, reduced the macrophage content, and increased the smooth muscle cell content in a time-dependent manner. Mechanistically, DVDMS-SDT activated mitochondria-caspase apoptosis in foam cells. Interestingly, activated by DVDMS-SDT, caspase-3 a key factor of apoptosis, reduced the expression of the anti-phagocytic molecule CD47 in foam cells. Of great importance, the promotion of macrophage efferocytosis by DVDMS-SDT can be eliminated by the overexpression of CD47. Overall, these results demonstrated that DVDMS-SDT effectively boosted efferocytosis via deactivation of CD47 expression, thereby reducing inflammation in advanced atherosclerotic plaques.

Non-lethal sonodynamic therapy facilitates the M1-to-M2 transition in advanced atherosclerotic plaques via activating the ROS-AMPK-mTORC1-autophagy pathway.

Emerging evidence indicates that macrophage functional polarization is critically involved in the development of atherosclerosis (AS). Here, we examined the role of 5-aminolaevulinic acid (ALA)-mediated non-lethal sonodynamic therapy (NL-SDT) in macrophage-subset polarization and atherosclerotic lesion stability and explored the potential underlying mechanisms. Using Western diet-fed apolipoprotein E (apoE)-/- and green fluorescent protein (GFP)-positive bone marrow (BM) chimeric mouse models, we demonstrated that NL-SDT promoted phenotypic switching of both BM-derived and resident macrophages from M1 to M2 and significantly inhibited AS progression. Further mechanistic studies indicated that NL-SDT enhanced macrophage differentiation toward the M2 phenotype by activating the reactive oxygen species (ROS)-5' AMP-activated protein kinase (AMPK)-mammalian target of rapamycin complex 1 (mTORC1)-autophagy signaling pathway in murine BM-derived M1 macrophages (BMDM1s). Moreover, NL-SDT drastically reduced lipid droplets, mainly by promoting apoAI-mediated cholesterol efflux in vitro. Specifically, administration of pharmacological inhibitors to the animal model showed a reciprocal effect on NL-SDT-induced macrophage polarization. These findings indicate that NL-SDT engages a virtuous cycle that enhances M1-to-M2 polarization, cholesterol efflux, and anti-inflammatory reactions in advanced plaque in vivo and in BMDM1s in vitro by activating the ROS-AMPK-mTORC1-autophagy pathway. This discovery might help elucidate the mechanism underlying NL-SDT as a potential treatment to prevent atherothrombotic events.

Early modulation of macrophage ROS-PPARγ-NF-κB signalling by sonodynamic therapy attenuates neointimal hyperplasia in rabbits.

Disruption of re-endothelialization and haemodynamic balance remains a critical side effect of drug-eluting stents (DES) for preventing intimal hyperplasia. Previously, we found that 5-aminolevulinic acid-mediated sonodynamic therapy (ALA-SDT) suppressed macrophage-mediated inflammation in atherosclerotic plaques. However, the effects on intimal hyperplasia and re-endothelialization remain unknown. In this study, 56 rabbits were randomly assigned to control, ultrasound, ALA and ALA-SDT groups, and each group was divided into two subgroups (n = 7) on day 3 after right femoral artery balloon denudation combined with a hypercholesterolemic diet. Histopathological analysis revealed that ALA-SDT enhanced macrophage apoptosis and ameliorated inflammation from day 1. ALA-SDT inhibited neointima formation without affecting re-endothelialization, increased blood perfusion, decreased the content of macrophages, proliferating smooth muscle cells (SMCs) and collagen but increased elastin by day 28. In vitro, ALA-SDT induced macrophage apoptosis and reduced TNF-α, IL-6 and IL-1ß via the ROS-PPARγ-NF-κB signalling pathway, which indirectly inhibited human umbilical artery smooth muscle cell (HUASMC) proliferation, migration and IL-6 production. ALA-SDT effectively inhibits intimal hyperplasia without affecting re-endothelialization. Hence, its clinical application combined with bare-metal stent (BMS) implantation presents a potential strategy to decrease bleeding risk caused by prolonged dual-antiplatelet regimen after DES deployment.

Sonodynamic Therapy Suppresses Neovascularization in Atherosclerotic Plaques via Macrophage Apoptosis-Induced Endothelial Cell Apoptosis.

During atherosclerosis plaque progression, pathological intraplaque angiogenesis leads to plaque rupture accompanied by thrombosis, which is probably the most important cause of arteries complications such as cerebral and myocardial infarction. Even though few treatments are available to mitigate plaque rupture, further investigation is required to develop a robust optimized therapeutic method. In this study using rabbit and mouse atherosclerotic models, sinoporphyrin sodium (DVDMS)-mediated sonodynamic therapy reduced abnormal angiogenesis and plaque rupture. Briefly, DVDMS is injected to animals, and then the plaque was locally exposed to pulse ultrasound for a few minutes. Furthermore, a small size clinical trial was conducted on patients with atherosclerosis. Notably, a significant reduction of arterial inflammation and angiogenesis was recorded following a short period of DVDMS-mediated sonodynamic therapy treatment. This beneficial outcome was almost equivalent to the therapeutic outcome after 3-month intensive statin treatment.