Christian Beauséjour

Formation

• Scientict, Sangamo Biosciences, California, USA (2004-2005)
• Postdoctoral fellow, Berlex Biosciences, California, USA (2003-2004)
• Postdoctoral fellow, Lawrence Berkeley National Laboratory, California, USA
• Ph.D., Pharmacology, Université de Montréal (1996-2001)

Laboratory research activities and experimental approches

• The role of cellular senescence in tissue regenerationStem cells expansion, maintenance, and differentiation must be tight controlled to ensure tissue repair, regeneration and longevity.  The microenvironment in which stem and progenitor cells reside plays a major role in their regenerative functions.  One such example is the bone marrow microenvironment which regulates hematopoietic stem cell (HSC) proliferation and differentiation.  The formation of senescent cells may contribute to the deterioration of stem cell niche.  cellular senescence is a stable growth arrest induced by a variety of stimuli, including DNA damage, telomere dysfunction and oncogenes.  Dysfunctional senescent cells accumulate in tissues in contrast to dying apoptotic cells.  A key feature of the senescent phenotype is the secretion of biologically active molecules that can disrupt normal tissue microenvironments and affect the behaviour of neighbouring cells.  Hence, our laboratory in studying how the accumulation of senescent cells (i.e. following exposure to ionizing radiation) affects HSC engraftment and proliferation.  We are investigating the possibility that the accumulation of nenescent cells following drug  treatments is responsible for late-affect of cancer survivors. We are also very much interested in studying how senescence affects differentiation of stem cells.
• Cellular therapyUsing cord-blood samples, we isolate non-hematopoietic multipotent stromal cells (MSCs) that have the potential to differentiate into several cell types such as adipocytes, osteocytes, or chondrocytes. Injection of purified MSCs has the potential to improve the regeneration of tissues such as ischemic hind limb, infracted hearts and injured skin. The objective of the laboratory is the increases bone marrow transplantation success rate and tissue repair using MSC based-therapies. Using technologies such as viral delivery and homologous recombination, we are looking to stably express therapeutic transgenes that would enhance the regenerative capabilities of MSCs.

Present members

• Basma Benabdallah – post-doctorante
• Cynthia Carbonneau – étudiante au doctorat
• Geneviève Despars, post-doctorante
• Audrey Fortin – étudiante à la M.Sc.
• Oanh Le – assistante de recherche

Publications

• Le O, Rodier F, Fontaine F, Coppe JF, Campisi J, DeGregori J, Laverdière C. Kokta V, Haddad E and Beauséjour C. Ionizing radiation-induced long-term expression of senescence markers in mice is independent of p53 and immune status. Aging Cell (in press).
• Benabdallah BF, Allard E, Yao S, Friedman G, Eliopoulos N, Gregory, PD, Holmes MC, Haddad E, Beauséjour C. Targeted gene addition to human mesenchymal stem cells as a cell-based plasma-soluble protein delivery platform. Cytotherapy (In press).
• Landry Y, Le O, Restivo T, Mace KA, and Beausejour CM. Secretion of SDF-1α by multipotent stromal cells enhances wound healing of skin exposed to ionizing radiation. Journal of Cellular and Molecual Medecine, 2009 Sep 1. [Epub ahead of print].
• Lombardo A, Genovese P, Beausejour C, Lee YL, Colleoni S, Kim KA, Ando D, Urnov F, Galli C, Gregory PD, Holmes MC, Naldini L. Gene editing in human stem cells using zinc finger nucleases and integrase-defective lentiviral vector delivery. Nature Biotechnology, Nov;25(11):1298-306 (2007).
• Beausejour CM, Campisi J.  Ageing: balancing regeneration and cancer.  Nature, Sep 28;443(7110):404-5 (2006).