Neutrophil Heterogeneity after Myocardial Infarction
Marie Piollet1,2, Jana Grune3,4, Clément Cochain5,6
1Université Paris Cité, PARCC, INSERM, Paris, France, marie.piollet@inserm.fr.
Insights
Neutrophil heterogeneity, or diversity, is observed in the heart after myocardial infarction. Understanding this neutrophil diversity is key to improving cardiac repair and healing processes following heart attacks.
Area of Science:
- Immunology
- Cardiovascular Biology
- Hematology
Background:
- Cardiovascular diseases are a leading global cause of death.
- Neutrophils play critical roles in myocardial infarction (MI) and cardiac repair.
- Recent research highlights significant heterogeneity among neutrophils during post-MI healing.
Purpose of the Study:
- To explore the heterogeneity of neutrophils in the context of myocardial infarction.
- To understand the origins and characteristics of diverse neutrophil populations in the heart post-MI.
- To investigate the implications of neutrophil diversity for cardiac healing.
Main Methods:
- Analysis of neutrophil populations in cardiac tissue after myocardial infarction.
- Characterization of neutrophil development and maturation.
- Investigation of neutrophil reprogramming in inflammatory conditions.
Main Results:
- Neutrophils exhibit diversity during development and maturation in steady-state conditions.
- Inflammatory environments induce neutrophil reprogramming, creating tissue-specific populations like SiglecF+ neutrophils.
- Post-MI, neutrophils in cardiac tissue originate from multiple sources (bone marrow, spleen, marginated pool) and show time-dependent heterogeneity.
Conclusions:
- Neutrophil heterogeneity within cardiac tissue may explain their dual beneficial and detrimental roles post-MI.
- Further research into neutrophil diversity offers potential for identifying therapeutic targets to enhance cardiac healing.
- Understanding the complex roles of diverse neutrophil subsets is crucial for managing cardiovascular diseases.
Background:
Cardiovascular diseases (CVDs), including myocardial infarction (MI), are the leading cause of death worldwide. Neutrophils have emerged as actors in noninfectious pathologies and play major roles in CVDs: after MI, neutrophils are the first cell recruited to the ischemic heart and display multifaceted roles in orchestrating post-MI tissue healing and repair. Interestingly, recent studies described a high heterogeneity in neutrophils during this process.
Summary:
At steady state, neutrophils present diversity during their development in hematopoietic organs and in the circulation after reaching maturity. Inflammatory environments elicit neutrophil reprogramming and further complexify neutrophil heterogeneity, especially leading to the emergence of tissue-specific populations including SiglecF+ neutrophils. Neutrophils play beneficial and deleterious roles after MI: they originate from diverse sources including the bone marrow, the spleen, and from the marginated neutrophil pool and display a time-dependent appearance of heterogeneous profile within the cardiac tissue.
Key Messages:
Neutrophil heterogeneity in the cardiac tissue could explain the contrasting roles ascribed to neutrophils after MI. Increased knowledge in neutrophil diversity will enable the identification of specific targets to improve cardiac healing processes.
