Methods of reprogramming cells
The present invention provides methods of reprogramming cells, for example, directly reprogramming a somatic cell of a first cell type into a somatic cell of a second cell type, are described herein. In particular, the present invention generally relates to methods for reprogramming a cell of an endoderm origin to a cell having pancreatic β-cell characteristics. The present invention also relates to an isolated population comprising reprogrammed cells, compositions and their use in the treatment of diabetes mellitus. In particular, the present invention relates to reprogramming a cell of an endoderm origin to a cell having pancreatic β-cell characteristics by increasing the protein expression of at least one transcription factor selected from Pdx1, Ngn3 or MafA in the cell of endoderm origin to reprogram the cell of an endoderm cell to a cell which exhibits at least one or at least two characteristics of an endogenous pancreatic β-cell.
1. A method for reprogramming a first differentiated cell of exocrine origin to a second differentiated cell that exhibits at least two characteristics of a pancreatic β-cell, does not express pancreatic hormones other than insulin and does not express amylase, the method comprising increasing protein expression of transcription factors Pdx-1, Ngn3 and MaFA in the first differentiated cell of exocrine origin, thereby reprogramming the first differentiated cell of exocrine origin to a second differentiated cell that exhibits at least two characteristics of a pancreatic β-cell, does not express pancreatic hormones other than insulin and does not express amylase, wherein the first differentiated cell of exocrine origin is isolated from a subject or located in vivo within the subject.
2. The method of claim 1 , wherein a characteristic of a pancreatic β-cell is secreting insulin in response to glucose.
3. The method of claim 1 , wherein a characteristic of a pancreatic β-cell is expression of at least one marker selected from the group consisting of: Ngn3−, Pdx1+ and MafA+.
4. The method of claim 1 , wherein the protein expression of the transcription factors is increased by contacting the first differentiated cell of exocrine origin with agents which increase the expression of the transcription factors.
5. The method of claim 1 , wherein the first differentiated cell of exocrine origin is in vitro.
6. The method of claim 1 , wherein the first differentiated cell of exocrine origin is ex vivo.
7. The method of claim 1 , wherein the first differentiated cell of exocrine origin is in vivo or present in a subject.
8. The method of claim 7 , wherein the subject has, or is at risk of developing, diabetes or a metabolic disorder.
9. The method of claim 1 , wherein the first differentiated cell of exocrine origin is a mammalian cell.
10. The method of claim 1 , wherein the method further comprises contacting the first differentiated cell of exocrine origin with at least one agent which increases the protein expression of at least one of the transcription factors selected from the group consisting of: NeuroD, Nkx2.2, Nkx6.1, Pax4, Pax6 or Isl1.
11. The method of claim 1 , wherein the second cell exhibiting at least two characteristics of a pancreatic β cell has an increased expression of a marker selected from the group consisting of: c-peptide, glucose transporter 2 (Glut2), glucokinase (GCK), prohormone convertase 1/3 (PC1/3), β-cell transcription factors NeuroD, Nkx2.2 and Nkx6.1 by a statistically significant amount relative to the first differentiated cell of ended exocrine origin from which the second cell that exhibits at least two characteristics of a pancreatic β cell was derived.
12. The method of claim 1 , wherein the second cell that exhibits at least two characteristics of a pancreatic βcell has a decreased expression of a marker selected from the group consisting of: Ck19, Nestin, Vimentin and Tuji by a statistically significant amount relative to the first differentiated cell of exocrine origin from which the β cell was derived.