Our group studies developmental heamatopoiesis and is also interested in the identification, purification, characterization and medical use of multipotent progenitor cells present in all tissues throughout life. The prototype of such ubiquitous progenitor cells is the mesenchymal stem cell, of which we have documented the native perivascular origin.
Working closely with our twin laboratory at the University of California at Los Angeles, we study the biology of perivascular stem cells and their possible role in tissue development, renewal and repair. Importantly, we have already engaged into the medical “translation” of these cells, principally for bone and cartilage regeneration.
Working closely with the Edinburgh / BHF Centre for Cardiovascular Science and our twin laboratory at the University of California in Los Angeles, we study the biology of perivascular stem cells and their possible role in tissue development, renewal and repair. The activity of our research group, at the newly formed BHF Centre for Vascular Regeneration located within CRM, is two-fold.
- Several projects address the basic biology of perivascular cells (pericytes and adventitial cells). We are investigating the molecular and anatomic identification in man and animals such as mice, rats, dogs, sheep, horse and fish.
We are also looking at the ontogeny, developmental potential, immunomodulatory activity, ability to sustain hematopoietic stem cells (role in the constitution of the blood stem cell "niche"), and communication with neighbouring cells – such as endothelial cells – and role of the latter in regulating these potentials in vivo.
- In parallel, our group is currently focussing on the therapeutic potential of these cells in cardiovascular and musculoskeletal medical conditions, such as cardiac repair, limb ischemia, muscle injury, cartilage regeneration and bone healing.
During normal development it was originally thought that ability of stem cells to give rise to multiple tissue/cell types becomes restricted so that in the adult only specialised tissue restricted stem cells remain. However, in recent years multipotent stem cells (mesenchymal stem cells - MSCs) have been identified in nearly all adult tissues investigated. These cells have been shown to give rise to bone, cartilage, fat, nerve cells and muscle.
For all these reasons, MSC have become popular candidates for stem cell therapies. In addition, MSC have unique properties; for instance they can control adverse effects of the immune system, like rejection of transplanted tissues, and auto-immune diseases. Although the stem cell properties of these MSCs was first reported in 1970s the native identity and localization of these cells remained unknown as they could only be isolated from tissues which had been dissociated into single cells and cultured long term.
Over the past few years, our laboratory has attempted to identify and purify MSCs and discovered that original MSC are located at the periphery of blood vessels. This explains why MSCs had been previously isolated from all organs, since all organs contain blood vessels. These ancestral MSC are named pericytes or adventitial cells, and are located around small and large vessels respectively.
Prof Péault has long been involved in the developmental biology of hematopoiesis. He was the first to identify and characterize the embryonic origin of human definitive hematopoietic stem cells, which are responsible for blood cell production. Our group continues to pursue these studies both in normal development and in the model of embryonic stem cells (ES cells). We have recently identified a novel marker for the ancestral hemangioblast, the common stem cell for hematopoietic cells and endothelial cells.
Approach and progress
Our group utilize a wide range of technologies to isolate and investigate the biology of perivascular stem cells and their possible roles in tissue development, renewal and repair. Our work will contribute to a better understanding of how novel perivascular stem cells contribute to tissue development and repair. In addition, using these purified stem cells instead of the conventional heterogenous MSC may offer siginificant opportunities to improve stem cell therapies