Deciphering Cellular Reprogramming

Following a breakthrough that was made in 2006 (by Takahashi & Yamanaka), today we can reverse cellular differentiation, and generate induced pluripotent stem cells from somatic cells by epigenetic “reprogramming”. We investigate what are the dramatic molecular changes happening in the cell during reprogramming and how they are connected to similar in-vivo processes. We pointed out two chromatin regulators that play a role in this process, one is essential for reprogramming (Utx, Mansour et al 2012), and the other (Mbd3/NuRD, Rais et al 2013) is an obstacle, which upon its near-removal the reprogramming becomes dramatically faster and synchronized.

Deterministic and synchronized iPS cell reprogramming

a, Mbd3 wild-type and depleted (Mbd3fl/− or Mbd3−/−) MEFs were directly infected with lentiviruses expressing a polycistronic OKSM cassette. Reprogramming efficiency (Oct4–GFP) was measured by FACS at day 10, showing a near-100% reprogramming efficiency in Mbd3 depleted cells. b, Secondary reprogrammable fibroblasts carrying an Oct4–GFP reporter and an mCherry constitutively expressed marker were single-cell-seeded and subjected to doxycycline-induced reprogramming. Reprogramming efficiency at day 8 was calculated by dividing the number of Oct4–GFP+ wells by mCherry+ wells (n = 3 per clone, ± indicates s.d. from average).