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Updated: Jul 11, 2025
Characterization of MLKL-mediated Plasma Membrane Rupture in Necroptosis
Published on: August 7, 2018
miR-223-3p Prevents Necroptotic Macrophage Death by Targeting Ripk3 in a Negative Feedback Loop and Consequently
Yunhui Jia1, Lianping Cheng1, Jiaxuan Yang1
1Department of Immunology, School of Basic Medical Sciences, and Department of Rheumatology, Zhongshan Hospital (Y.J., L.C., J.Y., J.M., Y.X., X.Y., X.Z., D.W., Y.W.), Fudan University, China.
Background:
The formation of large necrotic cores results in vulnerable atherosclerotic plaques, which can lead to severe cardiovascular diseases. However, the specific regulatory mechanisms underlying the development of necrotic cores remain unclear.
Methods:
To evaluate how the modes of lesional cell death are reprogrammed during the development of atherosclerosis, the expression levels of key proteins that are involved in the necroptotic, apoptotic, and pyroptotic pathways were compared between different stages of plaques in humans and mice. Luciferase assays and loss-of-function studies were performed to identify the microRNA-mediated regulatory mechanism that protects foamy macrophages from necroptotic cell death. The role of this mechanism in atherosclerosis was determined by using a knockout mouse model with perivascular drug administration and tail vein injection of microRNA inhibitors in Apoe mice.
Results:
Here, we demonstrate that the necroptotic, rather than the apoptotic or pyroptotic, pathway is more activated in advanced unstable plaques compared with stable plaques in both humans and mice, which closely correlates with necrotic core formation. The upregulated expression of Ripk3 (receptor-interacting protein kinase 3) promotes the C/EBPβ (CCAAT/enhancer binding protein beta)-dependent transcription of the microRNA miR-223-3p, which conversely inhibits Ripk3 expression and forms a negative feedback loop to regulate the necroptosis of foamy macrophages. The knockout of the Mir223 gene in bone marrow cells accelerates atherosclerosis in Apoe mice, but this effect can be rescued by Ripk3 deficiency or treatment with the necroptosis inhibitors necrostatin-1 and GSK-872. Like the Mir223 knockout, treating Apoe mice with miR-223-3p inhibitors increases atherosclerosis.
Conclusions:
Our study suggests that miR-223-3p expression in macrophages protects against atherosclerotic plaque rupture by limiting the formation of necrotic cores, thus providing a potential microRNA therapeutic candidate for atherosclerosis.
Insights
MicroRNA miR-223-3p limits necroptosis in macrophages, reducing necrotic core formation and protecting against atherosclerotic plaque rupture. This microRNA is a potential therapeutic target for cardiovascular disease.
Area of Science:
- Cardiovascular Biology
- Molecular Medicine
- Atherosclerosis Research
Background:
- Large necrotic cores in atherosclerotic plaques are linked to vulnerable lesions and severe cardiovascular diseases.
- The precise regulatory mechanisms driving necrotic core development in atherosclerosis are not fully understood.
Purpose of the Study:
- To investigate the reprogramming of lesional cell death pathways during atherosclerosis development.
- To identify microRNA-mediated regulation protecting macrophages from necroptosis.
- To assess the role of this mechanism in a mouse model of atherosclerosis.
Main Methods:
- Compared protein expression in necroptotic, apoptotic, and pyroptotic pathways across human and mouse plaque stages.
- Utilized luciferase assays and loss-of-function studies to pinpoint microRNA regulation of necroptosis in foamy macrophages.
- Employed knockout mouse models and perivascular drug/inhibitor administration to study the mechanism in vivo.
Main Results:
- Necroptosis, not apoptosis or pyroptosis, is significantly upregulated in advanced human and mouse plaques, correlating with necrotic core size.
- Receptor-interacting protein kinase 3 (Ripk3) upregulates miR-223-3p transcription, which then inhibits Ripk3, forming a negative feedback loop.
- Loss of miR-223-3p accelerates atherosclerosis in Apoe knockout mice, while its inhibition exacerbates plaque formation.
Conclusions:
- Macrophage miR-223-3p expression is protective against atherosclerotic plaque rupture by restricting necrotic core formation.
- miR-223-3p represents a promising microRNA therapeutic candidate for treating atherosclerosis.
