The histone demethylases Jhdm1a/1b enhance somatic cell reprogramming in a vitamin-C-dependent manner

Delineating nuclear reprogramming

Nuclear reprogramming is described as a molecular switch, triggered by the conversion of one cell type to another. Several key experiments in the past century have provided insight into the field of nuclear reprogramming. Previously deemed impossible, this research area is now brimming with new findings and developments. In this review, we aim to give a historical perspective on how the notion of nuclear reprogramming was established, describing main experiments that were performed, including (1) somatic cell nuclear transfer, (2) exposure to cell extracts and cell fusion, and (3) transcription factor induced lineage switch. Ultimately, we focus on (4) transcription factor induced pluripotency, as initiated by a landmark discovery in 2006, where the process of converting somatic cells to a pluripotent state was narrowed down to four transcription factors. The conception that somatic cells possess the capacity to revert to an immature status brings about huge clinical implications including personalized therapy, drug screening and disease modeling. Although this technology has potential to revolutionize the medical field, it is still impeded by technical and biological obstacles. This review describes the effervescent changes in this field, addresses bottlenecks hindering its advancement and in conclusion, applies the latest findings to overcome these issues.

Vitamin C improves the quality of somatic cell reprogramming

The reprogramming of somatic cells to a pluripotent state is prone to errors that could hamper the use of this technology. A new study now shows that vitamin C enhances the quality of somatic cell reprogramming in mice, highlighting the possibility that further manipulation of culture conditions could improve this technology for regenerative medicine.

Ascorbic acid prevents loss of Dlk1-Dio3 imprinting and facilitates generation of all-iPS cell mice from terminally differentiated B cells

The generation of induced pluripotent stem cells (iPSCs) often results in aberrant epigenetic silencing of the imprinted Dlk1-Dio3 gene cluster, which compromises the cells’ ability to generate entirely iPSC-derived adult mice (“all-iPSC mice”). Here, we show that reprogramming in the presence of ascorbic acid attenuates hypermethylation of Dlk1-Dio3 by enabling a chromatin configuration that interferes with binding of the de novo DNA methyltransferase Dnmt3a. This allowed us to generate all-iPSC mice from mature B cells, which have thus far failed to support the development of exclusively iPSC-derived postnatal animals. Our data demonstrate that transcription factor-mediated reprogramming can endow a defined, terminally differentiated cell type with a developmental potential equivalent to that of embryonic stem cells. More generally, these findings indicate that culture conditions during cellular reprogramming can strongly influence the epigenetic and biological properties of resultant iPSCs.