Methods of differentiating and protecting cells by modulating the p38/MEF2 pathway
View Patent ↗The present invention provides a method of differentiating progenitor cells to produce a population containing protected neuronal cells. A method of the invention includes the steps of contacting the progenitor cells with a differentiating agent; and introducing into the progenitor cells a nucleic acid molecule encoding a MEF2 polypeptide or an active fragment thereof, thereby differentiating the progenitor cells to produce a population containing protected neuronal cells. In one embodiment, the MEF2 polypeptide is human MEF2C or an active fragment thereof.
1. A method of transplantation, comprising the steps of:
(a) contacting in vitro a population of progenitor cells with a differentiating agent;
(b) introducing in vitro into said progenitor cells a nucleic acid molecule encoding a constitutively active MEF2 polypeptide or an active fragment thereof, wherein said constitutively active MEF2 polypeptide or active fragment thereof has transactivation activity that is independent of phosphorylation; and
(c) transplanting said progenitor cells comprising said nucleic acid molecule into a patient to produce a cell population containing protected neuronal cells in said patient.
2. The method of claim 1 , wherein said MEF2 polypeptide is human MEF2C, or an active fragment thereof.
3. The method of claim 1 , wherein said constitutively active MEF2 polypeptide is a MEF2/VP16 fusion protein.
4. The method of claim 1 , wherein said constitutively active MEF2 polypeptide contains one or more serine/threonine to aspartic acid/glutamic acid substitutions in the MEF2 transactivation domain.
5. The method of or claim 1 , further comprising inhibiting caspase activity in said progenitor cells.
6. The method of claim 1 , wherein said progenitor cells are human stem cells.
7. The method of claim 1 , wherein said progenitor cells are embryonic stem cells.
8. The method of claim 7 , wherein said embryonic stem cells are human embryonic stem cells.
9. The method of claim 1 , wherein said progenitor cells are hematopoietic progenitor cells.
10. The method of claim 9 , wherein said hematopoietic progenitor cells are human hematopoietic progenitor cells.
11. The method of claim 1 , further comprising selecting CD133-positive human progenitor cells.
12. The method of claim 1 , further comprising selecting CD133-positive/CD34-positive human progenitor cells.
13. The method of claim 1 , further comprising selecting CD133-positive/CD34-negative human progenitor cells.
14. The method of claim 1 , further comprising selecting CD133-positive/CD34-negative/CD45-negative human progenitor cells.
15. The method of claim 1 , further comprising selecting CD34-negative/CD38-negative/Lin-negative human progenitor cells.
16. The method of claim 1 , further comprising selecting CD34-positive/CD38-negative/Lin-negative/Thy-1-negative human progenitor cells.
17. The method of claim 1 , wherein said differentiating agent is retinoic acid.
18. The method of claim 1 , wherein said differentiating agent is selected from the group consisting of neurotrophic factor 3, epidermal growth factor, insulin-like growth factor 1 and a platelet-derived growth factor.
19. The method of claim 1 , wherein said population containing protected neuronal cells comprises at least 50% neuronal cells.
20. The method of claim 1 , wherein said nucleic acid molecule is stably introduced into said progenitor cells.