Compositions and methods for promoting beta cell maturity

1. A method for providing an enriched population of mature, glucose-responsive insulin secreting cells, the method comprising:

providing an initial cell population comprising at least 10% pancreatic islet-isolated insulin-expressing immature beta cells, wherein the cells do not substantially secrete insulin in response to glucose; and

contacting the initial population of immature beta cells with triiodothyronine (T3) thyroid hormone or an analog thereof under conditions and for a time sufficient to induce maturation of at least some of the cells into mature cells that secrete insulin in the presence of glucose in vitro,

thereby providing an enriched population of mature, glucose-responsive insulin secreting cells.

2. A method for providing an enriched population of mature, glucose-responsive insulin secreting cells, the method comprising:

providing an initial cell population comprising at least 10% pancreatic islet-isolated insulin-expressing immature beta cells, wherein the cells secrete a level of insulin in the presence of glucose in vitro; and

contacting the initial population of cells with triiodothyronine (T3) thyroid hormone or an analog thereof under conditions and for a time sufficient to induce maturation of at least some of the cells into mature cells that secrete a second level of insulin in the presence of glucose in vitro, wherein the second insulin level is greater than the first level,

thereby providing an enriched population of mature, glucose-responsive insulin secreting cells.

3. The method of claim 2 , wherein the initial population of insulin-expressing cells is provided by a method comprising:

providing a beta cell progenitor; and

differentiating the progenitor cell into a population comprising insulin-expressing cells.

4. The method of claim 2 , wherein the initial population of insulin-expressing cells secretes substantially no insulin in a glucose responsive manner.

5. The method of claim 2 , wherein the initial population of insulin-expressing immature beta cells secretes substantially less insulin in a glucose responsive manner than is secreted by a comparable population of mature beta cells.

6. The method of claim 2 , wherein the initial population of insulin-expressing cells expresses insulin, but does not substantially express MafA.

7. The method of claim 2 , wherein the initial population of insulin-expressing cells is an enriched population of immature beta cells.

8. The method of claim 2 , wherein the analog of T3 is selected from the group consisting of T4 thyroid hormone, thyromimetics, TRbeta selective agonist-GC-1, GC-24, 4-Hydroxy-PCB 106, MB07811, MB07344, 3,5-diiodothyropropionic acid (DITPA); GC-1; 3-Iodothyronamine (T(1)AM) and 3,3′,5-triiodothyroacetic acid (Triac); KB-2115 and KB-141; thyronamines; SKF L-94901; DIBIT; 3′-AC-T2; tetraiodothyroacetic acid (Tetrac) and triiodothyroacetic acid (Triac), 3,3′,5′-triiodothyronine (rT3), 3,3′-diiodothyronine (3,3′-T2), 3,5-diiodothyronine (T2), 3-iodothyronamine (T1AM) and thyronamine (T0AM), 3,5,3′-triiodothyropropionic acid (Triprop), 3,5-dibromo-3-pyridazinone-l-thyronine (L-940901), N-[3,5-dimethyl-4-(4′-hydroxy-3′-isopropylphenoxy)-phenyl]-oxamic acid (CGS 23425), 3,5-dimethyl-4[(4′-hydroxy-3′-isopropylbenzyl)-phenoxy]acetic acid (GC-1), 3,5-dichloro-4[(4-hydroxy-3-isopropylphenoxy)phenyl]acetic acid (KB-141), and 3,5-diiodothyropropionic acid (DITPA).

9. The method of claim 2 , wherein the initial population of insulin-expressing cells express one or more, two or more, three or more, or all four of MMP2, CKI9, SPD, and Frizzled 2.

10. A method of treating or reducing the risk of developing diabetes in a subject, the method comprising:

administering to a subject an enriched population of mature, glucose-responsive insulin secreting cells produced by the method of claim 2 .