Stem cells

Oral exam

STEM CELLS I

Definition of stem cell; methods of division and differentiation potential; general properties of the stem niche; types of adult stem cells; the male and female germinal stem niches of drosophila; introduction to the adult neural stem niche. The embryonic neural stem cell and its lineage; radial glia and embryonic neurogenesis; positional and histological identity; corticogenesis and radial migration; nerogenetic timing of the cortical layers; embryonic neural stem niche.

Discovery and characterization of the neurogenetic properties of radial glial cells. Comparison between invertebrate neurogenesis and vertebrate neurogenesis. Description of Notch signaling in invertebrates. Lateral inhibition in invertebrates. conservation of the molecular mechanisms of lateral inhibition (proneural genes, neurogenic genes and their interaction) in vertebrates.

The adult stem cell neurogenetic niche. Brief description of the different niches. The VZ-SVZ niche as a paradigm for controlling neural stemness. the four cellular components of the niche: cells E, B, C and A. "Pinwheel" structure of the niche. Extrinsic signals and intrinsic control signals of stemness. Control of the niche by Vcam1 and by the Notch, SHH, EGF and BMP reports. Paracrine influence of neurotransmitters GABA and 5-HT, and of IL-1, on stemness

The qNSC / aNSC balance control in the adult neurogenic niche of V-SVZ (http://dx.doi.org/10.1016/j.stemcr.2016.08.016). The role of SHH in controlling the pool of NSCs in the adult neruogenetic niche of the SGZ (DOI: https://doi.org/10.7554/eLife.42918)

The adult intestinal stem cell niche. Adult hematopoietic stem cells. Mesenchymal cells as an example of mutlipotent adult stem cells.

Mouse embryonic stem cells: ground state and primed cells, chemical niches for the maintenance of pluripotency. Differentiation of pluripotent cells in vitro mimics the early development of embryonic tissues. Role of different intracellular signaling in the differentiation of pluripotent cells towards distinct differentiation fates in vitro. Human embryonic and reprogrammed pluripotent cells, and their use for cell therapy and disease modeling. Mesoendodermal and cerebral organoids. Molecular mechanisms underlying the maintenance of ground state pluripotency: role of ERK and Wnt signaling.

Cellular reprogramming according to the "Yamanaka" protocol: role of transcription factors of pluripotency. Cellular competence in reprogramming. Chromatin properties of pluripotent cells. Hyper-transcriptional pluripotent chromatin model and differentiation by tissue-specific inhibition of transcription through epigenetic remodeling. Role of RNA interference in the control of the expression of chromatin remodelers and modifiers essential to the transition from ground-state pluripotency to epiblast.

Dual role of the SOX2 transcription factor in pluripotency and neuralization. Experimental evidence of tissue-specific SOX2 / OCT4 and SOX2 / BRN2 heteroduplex formation and their differentiated control of pluripotency and neural gene targets, respectively. Definition of Lamin-associated domains (LADs) and their study during cell differentiation. Evidence of conformational chromatin changes underlying tissue-specific transcriptional competence.

STEM CELLS II

The protocols underlying the in vitro neuralization of pluripotent cells (ESCs, iPSc) and their logical for using intracellular signaling molecules in relation to the known developmental processes of the early embryo.

Molecular control of neural induction. The signaling of Wnt and that of Tgf-beta in the induction of the organizer's BMP inhibitors. The effect of Wnt in the induction of key neuralization genes in presumptive neural ectoderna. Induction of the regional specificity of the nervous system. Function of the node and AVE in the postero-anterior polarization of the mammalian nervous system. Evolutionary conservation of neuralization and antero-posterior patterning signals in vertebrates. The regulation of dorso-ventral patterning in the neural tube: the example of the spinal cord. The gradients of BMP and SHH are translated into segments of positional identity thanks to the induction of transcription factors such as Olig2 and nkx2.2, which are endowed with different activation sensitivities and able to co-repress their own expression.

Production of human neurons with dorsal and ventral positional identity of various CNS and SNP regions through the temporally targeted use of agonists and antagonists of the Wnt, BMP, Shh, Tgfb, FGF, RA signaling pathways.

In vitro modeling of the embryonic development of the retina, cerebral cortex, hippocampus, spinal cord, neural crest derivatives, for the discovery of new molecular mechanisms of cell identity specification, diagnosis and treatment of genetic and neurodegenerative diseases.

Role of Notch-Delta in the control of proliferation and neurogenesis of the mammalian cerebral cortex: in vivo and in vitro studies. Mechanisms of regulation of the evolutionary expansion of the cerebral cortex. The developmental logic of the mammalian cerebral cortex: acquisition of area and layer identity. The paracrine signaling centers and the master regulatory genes of area and layer identity. The Bolean logic model of successive specifications of cortical cellular identity.

Use of reprogrammed human cells hiPSCs to model development and pathologies of the cerebral cortex. Cell cultures in adhesion and cerebral organoids can faithfully reproduce the stratification process of the human cortex in vitro.

Use of cerebral organoids to study the effects of the DISC1 gene mutation, responsible for the onset of autism spectrum disorders, in the stratification of the cortex. 2D and 3D cultures of cortical neurons derived from iPSCs cells of chimpanzees, macaques or humans show the presence of a genetic program intrinsic to the neural progenitor capable of directing and prolonging cortical neurogenesis with the timing and modalities of the brain development of the three species. 2D cultures of cortical neurons derived from hiPSCs from human patients for in vitro modeling of human cortical neural networks. Study of the structural and functional consequences of the SHANK2 gene mutation, which causes autism spectrum disorders.

Interface with mouse and human neuronal networks in culture for the study of spontaneous and induced electrical activity. The methodology of Multiple Electrodes Arrays (MEA) and calcium sensors for the direct and indirect recording of the potentials of neuronal networks.

Scott F. Gilbert & Michael J. F. Barresi, Developmental Biology, 11th edition, Sinauer Associates, Inc. , Publishers Sunderland, Massac.

Papers in specialized journals.