Methods of regulating differentiation in stem cells
The present invention provides methods, media and compositions capable of modulating the differentiation of stem cells. Applicants have discovered that agonists of lysophospholipid receptors and ligands of class III tyrosine kinase receptors are useful in preventing the spontaneous differentiation of stem cells. The ligands and agonists may be used alone, or in combination where they have a synergistic effect. Also provided are cells produced using the methods and media, and methods of treating stem cell related diseases using the compositions described herein. Methods of identifying compounds useful in finding other agents useful in the modulation of stem cell differentiation are also disclosed.
1. A method for inhibiting differentiation of an embryonic stem cell, which method comprises providing an embryonic stem cell, incubating the embryonic stem cell in the presence of an agonist of a LPL receptor, the agonist selected from the group consisting of S1P, dihydro S1P, LPA, PAF and SPC.
2. A method according to claim 1 wherein the LPL receptor is selected from the group consisting of S1P1, S1P2, and S1P3.
3. A method according to claim 1 wherein the agonist is S1P.
4. A method according to claim 1 wherein the agonist is dihydro S1P.
5. A method according to claim 1 wherein the stem cell is co-incubated with an agent selected from the group consisting of TNF alpha, NGF (nerve growth factor), a muscarinic acetyicholine agonist, a serum and a phorbol ester.
6. A method according to claim 1 wherein the embryonic stem cell is a human embryonic stem cell.
7. A method for inhibiting differentiation of an embryonic stem cell, which method comprises providing an embryonic stem cell, incubating the embryonic stem cell in the presence of an agonist of a LPL receptor and a ligand of a class III tyrosine kinase receptor, the agonist selected from the group consisting of S1P, dihydro S1P, LPA, PAF and SPC, and the ligand is a PDGF.
8. A method according to claim 7 wherein the tyrosine kinase receptor is PDGFR-α or PDGFR-β.
9. A method according claim 7 , wherein the PDGF is PDGFaa, PDGFab or PDGFbb.
10. A method for propagating an embryonic stem cell in an differentiated state, which method comprises providing an embryonic stem cell, incubating the embryonic stem cell in the presence of an agonist of a LPL receptor, the agonist selected from the group consisting of S1P, dihydro S1P, LPA, PAF and SPC.
11. The method of claim 10 , wherein the stem cell is a hES cell.
12. A method according to claim 10 wherein the LPL receptor is selected from the group consisting of S1P1, S1P2, and S1P3.
13. A method according to claim 10 wherein the agonist is S1P.
14. A method according to claim 10 wherein the agonist is dihydro S1P.
15. A method according to claim 10 wherein the stem cell is co-incubated with an agent selected from the group consisting of TNF alpha, NGF (nerve growth factor), a muscarinic acetyicholine agonist, a serum and a phorbol ester.
16. A method of producing a population of proliferating undifferentiated embryonic stem cells which method comprises providing an embryonic stem cell, incubating the embryonic stem cell in the presence of an agonist of a LPL receptor, the agonist selected from the group consisting of S1P, dihydro S1P, LPA, PAF and SPC.
17. A method according to claim 16 wherein the LPL receptor is selected from the group consisting of S1P1, S1P2 and S1P3.
18. A method according to claim 16 wherein the agonist is S1P.
19. A method according to claim 16 wherein the agonist is dihydro S1P.
20. A method according to claim 16 wherein the stem cell is co-incubated with an agent selected from the group consisting of TNF alpha, NGF (nerve growth factor), a muscarinic acetyicholine agonist, a serum and a phorbol ester.
21. A method according to claim 16 wherein the stem cell is a hES cell.
22. A method of producing a population of proliferating undifferentiated embryonic stem cells which method comprises providing an embryonic stem cell, incubating the embryonic stem cell in the presence of an agonist of a LPL receptor and a ligand of a class III tyrosine kinase receptor, the agonist selected from the group consisting of S1P, dihydro S1P, LPA, PAF and SPC, and the ligand is a PDGF.
23. A method according to claim 22 wherein the tyrosine kinase receptor is PDGFR-α or PDGFR-β.
24. A method according claim 22 , wherein the PDGF is PDGFaa, PDGFab or PDGFbb.
25. A method for propagating an embryonic stem cell in an undifferentiated state, which method comprises providing an embryonic stem cell, incubating the embryonic stem cell in the presence of an agonist of a LPL receptor and a ligand of a class III tyrosine kinase receptor, the agonist selected from the group consisting of S1P, dihydro S1P, LPA, PAF and SPC, and the ligand is a PDGF.
26. A method according to claim 25 wherein the tyrosine kinase receptor is PDGFR-α or PDGFR-β.
27. A method according to claim 25 wherein the PDGF is PDGFaa, PDGFab or PDGFbb.
28. A method according to claim 22 wherein the stem cell is a hES cell.
29. A method according to claim 22 wherein the LPL receptor is selected from the group consisting of S1P1, S1P2, and S1P3.
30. A method according to claim 22 wherein the agonist is S1P.
31. A method according to claim 22 wherein the agonist is dihydro S1P.