Stem Cell Science

A brief update

9/10/08

Gerry Maxwell

Jaenisch and Young 2008 Cell 132:567-582.

Jaenisch and Young 2008 Cell 132:567-582

I. Park and G.Q. Daley 2007 Nature Cell biology 9: 871-873.

Jaenisch and Young 2008 Cell 132:567-582

Kinetics of reprogramming

• Reprogramming using virally encoded transcription factors in vitro takes many days and not all markers of pluripotency are activated together

• In addition, it appears that stochastic events are involved in reprogramming because clonally derived cells do not reprogram in a synchronous fashion

Creation of Patient Specific Cell Lines

• Originally published in Science Express on 31 July 2008• Science 29 August 2008:• Vol. 321. no. 5893, pp. 1218 - 1221• DOI: 10.1126/science.1158799•

• Induced Pluripotent Stem Cells Generated from Patients with ALS Can Be Differentiated into Motor Neurons

• John T. Dimos,1* Kit T. Rodolfa,1,2* Kathy K. Niakan,1 Laurin M. Weisenthal,1 Hiroshi Mitsumoto,3,4 Wendy Chung,4,5 Gist F. Croft,4,6 Genevieve Saphier,1 Rudy Leibel,5 Robin Goland,7 Hynek Wichterle,4,6 Christopher. Henderson,4,6 Kevin E Eggan1

In vivo reprogramming of adult pancreatic exocrine cells tocells

Zhou,Brown, Kanareck, Rajagopal, and Melton

2008 Nature 07134

Q Zhou et al. Nature 000, 1-6 (2008) doi:10.1038/nature07314

A combination of three transcription factors inducesinsulin+ cells in adult mouse pancreas in vivo.

Q Zhou et al. Nature 000, 1-6 (2008) doi:10.1038/nature07314

Induced new b-cells remodel vasculature and ameliorate hyperglycaemia.

Characteristics of in vivo

reprogramming • Like in vitro the inducing factors are only

required transiently• Does not appear to require cell division• Occurs as early as 3 days-faster than in vitro (7-

30 days in vitro)• Efficiency is up to 20%- much higher than in vitro• Does not appear to involve dedifferentiation as

does in vitro reprogramming