U1251 INSERM
Marseille Medical Genetics
Aix Marseille University
Congenital heart defects (CHD) are the most common type of birth defect, occurring in about 1% of all births. Our main goal it to better understand the genetic basis and developmental etiology of CHD.
We use experimental embryological, genetic and molecular approaches to analyze the development of the cardiovascular system. Using in vivo and in vitro models, we aim to decipher mechanisms that control heart development. Our objective is to establish relationships between signaling pathways and transcription factors that control identity of progenitors and contribute to cardiac malformations. We also study the molecular and cellular mechanisms that lead to valve diseases.
Cardiac progenitors:
Elucidating the mechanisms involved in the restriction of cardiac progenitors will lead to a better understanding of CHD and will ultimately lead to the development of novel therapies aimed at healing injured human hearts.
Our work over the past few years has established the role of the vitamin A derivative, retinoic acid, in defining the boundaries of presumptive heart fields during early development. Inhibition of retinoic acid signaling leads to expansion of cardiac progenitor pools. We have also shown that certain Hox genes, downstream targets of retinoic acid, are expressed in a distinct domain of future myocardium known as the second heart field, which contribute cells to the future atria and outflow tract. Using mutant mice, we have demonstrated that Hoxb1 regulates proliferation and differentiation of specific progenitors and genetically interacts with Hoxa1 during cardiac outflow tract development. We continue to study the roles of retinoic acid and Hox genes in patterning and steering cell fate within the second heart field and their impact on the resultant tissues. Read more
Heart valve diseases:
Bicuspid aortic valve (BAV) and other valvular anomalies are among the most common CHD. Extracellular matrix changes occur in many valvular diseases. However, the molecular mechanisms underlying these pathologies are poorly understood. We have recently uncovered the role of the zinc finger transcription factor Krox20 during heart valve development. Loss of Krox20 function leads to defective aortic valve structure associated with aortic dysfunction. Functional promoter analysis demonstrated that Krox20 regulates the fibrillar collagens Col1a1 and Col3a1 genes during the remodeling of aortic valves. Studies of the contributions of different lineages to valve development and disease are ongoing. We use state-of-the-art genetic technologies, including whole exome sequencing, to discover and understand the function of new genes in aortic valve diseases such as BAV. Read more
The laboratory is located at the Medical school of Marseille, in a research unit of the French Institute for Health and Medical Research (INSERM) and the Aix Marseille University (AMU). Our current research projects are supported by the ANR, the AFM-Telethon and the FRM.
The Marseille Medical Genetics Center is composed of 8 independent teams headed by:
Anne Barlier - Mechanisms of Paracrine and Endocrine Disorders.
Marc Bartoli - Translational neuromyology.
Anaïs Baudot - System biomedicine.
Fabienne Lescroart - Normal and pathophysiological specification of cardio-pharyngeal mesoderm. ATIP-AVENIR Team.
Frédérique Magdinier - Epigenetic and nucleoskeleton dynamics in rare diseases.
Francesca Rochais - Heart development and cardiac regeneration.
Laurent Villard - Human neurogenetics.
Stéphane Zaffran - Genetics of cardiac diseases.
