Professor Matthias Nahrendorf

Title talk: Leukocytes in cardiovascular health

Abstract:

Monocytes and macrophages are innate immune cells that reside and accumulate in atherosclerotic lesions but also in the healthy and injured heart and brain. The cells and their subsets pursue distinct functions in steady state and disease, and their tenure may range between hours to months. Some subsets are highly inflammatory, while others support tissue repair. The talk discusses current concepts of cell supply by the hematopoietic system, lineage relationships and systems’ cross talk, highlights open questions, and describes imaging tools for studying monocytes, macrophages and their progenitors.

Biography:

My research focuses on the role of immunity in cardiovascular health and disease, specifically in atherosclerosis, myocardial infarction (MI), heart failure and stroke. Of particular interest are the function, supply and production of leukocytes, and the signals that regulate inflammation after injuries such as MI or stroke. We described that after MI, the spleen releases a large population of ready-made leukocytes that travel to the ischemic heart (Science 2009). We discovered that cardiovascular disease remodels bone marrow hematopoiesis. Atherosclerosis, MI, heart failure, chronic stress and sedentary lifestyle modulate the hematopoietic stem cell niche, activating proliferation of myeloid progenitor cells which supply larger quantities of inflammatory cells. Bone marrow-derived macrophages promote atrial fibrillation in mice and human patients via pro-inflammatory and –fibrotic functions (Science 2023). Neutrophils elicit ventricular tachycardia by perforating cardiomyocyte membranes (Science 2025). Resident heart macrophages, on the other hand, do not derive from circulating cells and stabilize cardiac conduction (Cell 2017). The laboratory also develops and employs imaging to sample biology non-invasively, using MR, nuclear, optical and microscopic modalities. An exceptional aspect of our projects is their cross-disciplinary character which is mirrored in my effort to bridge scientific fields (such as immunology and cardiac physiology) by dedicated interdisciplinary training of the next generation of scientists. Over a dozen alumni of the Nahrendorf lab now lead their own academic laboratories. I am the Editor-in-Chief at JACC: BTS and, together with Peter Libby, codirect the Mass General Brigham Center for Inflammation Imaging.

Association:

https://csb.mgh.harvard.edu/nahrendorf

Host:

Dr Aleksander Ivetic