Methods for reprogramming cells and uses thereof
Described herein are methods for cell dedifferentiation, transformation and eukaryotic cell reprogramming. Also described are cells, cell lines, and tissues that can be transplanted in a patient after steps of in vitro dedifferentiation and in vitro reprogramming. In particular embodiments the cells are Stem-Like Cells (SLCs), including Neural Stem-Like Cells (NSLCs). Also described are methods for generating these cells from human somatic cells and other types of cells. Also provided are compositions and methods of using of the cells so generated in human therapy and in other areas.
1. A method of obtaining a neural multipotent or unipotent cell, comprising:
i) providing a cell of a first type which is not a neural multipotent or unipotent cell;
ii) introducing into the cell of a first type an agent capable of remodeling the chromatin and/or DNA of the cell, wherein the agent capable of remodeling the chromatin and/or DNA is a histone acetylator, an inhibitor of histone deacetylation, a DNA demethylator, and/or a chemical inhibitor of DNA methylation;
iii) introducing into the cell of a first type a reprogramming polypeptide and/or a polynucleotide encoding said reprogramming polypeptide, wherein the reprogramming polypeptide comprises Musashi1 (Msi1) and/or Neurogenin 2 (Ngn2); and
iv) placing or maintaining the cell in a neural cell culture medium and maintaining intracellular levels of the reprogramming polypeptide or the polynucleotide encoding the reprogramming polypeptide for a sufficient period of time to allow a neural multipotent or unipotent cell to be obtained.
2. The method of claim 1 wherein, in step (ii), the remodeling agent is methyl-CpG binding domain protein 2 (MBD2), DNA-damage-inducible beta (Gadd45b), valproic acid or 5-azacytidine.
3. The method of claim 1 or 2 , wherein the cell of a first type is transfected with at least one expression vector encoding polypeptide(s) selected from the group consisting of:
Musashi1 (Msi1) in step (iii);
Neurogenin 2 (Ngn2) in step (iii);
Msi1 and Ngn2 in step (iii);
Msi1 in step (iii) and MBD2 in step (ii);
Ngn2 in step (iii) and MBD2 in step (ii);
Msi1 and Ngn2 in step (iii) and MBD2 in step (ii);
Msi1, Ngn2 and Ascl1 in step (iii);
Msi1, Ngn2 and Ascl1 in step (iii), and MBD2 in step (ii);
Msi1, Ngn2 and Sox2 in step (iii); and
Msi1, Ngn2 and Sox2 in step (iii), and MBD2 in step (ii).
4. The method of claim 1 , wherein the neural multipotent or unipotent cell so obtained possesses one or more of the following characteristics:
i) expression of one or more neural stem cell marker selected from the group consisting of Sox2, Nestin, Glial Fibrillary acidic protein (GFAP), Msi1 and Ngn2;
ii) form neurospheres in a neurosphere colony formation assay;
iii) is capable of differentiation into at least one cell expressing a marker specific for a neuronal, astrocyte or oligodendrocyte cell;
iv) has one or more morphological neurite processes selected from the group consisting of axons and dendrites, wherein the neurite processes are greater than one cell diameter in length upon neuronal differentiation;
v) expression of at least one neural-specific antigen selected from the group consisting of neural-specific microtubule associated protein 2 (Map2), neural cell adhesion molecule (NCAM), and a marker for a neurotransmitter;
vi) expression of one or more functional neural markers upon neuronal differentiation;
vii) capable of releasing one or more neurotrophic factors;
viii) capable of significantly improving one or more neurological or motor or sensory functional measures after placement of an adequate number of the said neural multipotent or unipotent cells into the void in a brain ablation model;
ix) capable of significantly improving or maintaining one or more neurological or motor or sensory functional measures after injecting an adequate number of the said neural multipotent or unipotent cells into an Experimental Allergic Encephalomyelitis (EAE) mouse model; and
x) capable of improving one or more neurological or motor or sensory functional measures more significantly than human neuroprogenitor cells (hNPCs) in central nervous system injury or neurodegenerative models.
5. The method of claim 1 , wherein the neural multipotent cell so obtained possesses all of the following characteristics:
(i) expresses neural multipotent markers including Nestin and Sox2;
(ii) can self-renew for significantly longer than a somatic cell;
(iii) is not a cancerous cell;
(iv) is stable and not artificially maintained by forced gene expression and may be maintained in standard neural stem cell media;
(v) can differentiate to a neuroprogenitor cell, a neural precursor cell, a neuron, an astrocyte, an oligodendrocyte or to another more differentiated cell type of the neural lineage; and
(vi) does not exhibit uncontrolled growth, teratoma formation, and tumor formation in vivo.
6. The method of claim 1 , wherein a plurality of neural multipotent or unipotent cells are obtained and wherein the plurality of neural multipotent or unipotent cells are organized within a three-dimensional structure.
7. The method of claim 1 , wherein the cell of the first type is selected from the group consisting of adipose-derived stem cell, mesenchymal stem cell, hematopoietic stem cell, skin derived precursor cell, hair follicle cell, fibroblast, keratinocyte, epidermal cell, endothelial cell, epithelial cell, granulosa epithelial cell, melanocyte, adipocyte, chondrocyte, hepatocyte, B lymphocyte, T lymphocyte, granulocyte, macrophage, monocyte, mononuclear cell, pancreatic islet cell, sertoli cell, neuron, glial cell, cardiac muscle cell, and other muscle cell.
8. The method of claim 1 , wherein the cell of the first cell type is a human fibroblast cell, human keratinocyte, human adipose derived stem cell, human mesenchymal stem cells, or human hematopoietic stem cell.
9. The method of claim 1 , comprising treating the cells of a first cell type with a cytoskeleton disruptor.
10. The method of claim 9 , wherein the cytoskeleton disruptor is Cytochalasin B or a myosin inhibitor.
11. The method of claim 1 , wherein the neural unipotent cell so obtained possesses all of the following characteristics:
(i) expresses a neuronal marker and/or a glial marker;
(ii) is not a cancerous cell;
(iii) is stable and not artificially maintained by forced gene expression and may be maintained in standard neural or glial cell media; and
(iv) does not exhibit uncontrolled growth, teratoma formation, and tumor formation in vivo.
12. The method of claim 11 , wherein the neuronal marker is βIII-tubulin.
13. The method of claim 11 , wherein the glial marker is selected from the group consisting of GFAP and O4.