Generation of two transgene-free human iPSC lines from CD133+ cord blood cells

Generation of NKX2.5GFP Reporter Human iPSCs and Differentiation Into Functional Cardiac Fibroblasts

Direct cardiac reprogramming has emerged as an interesting approach for the treatment and regeneration of damaged hearts through the direct conversion of fibroblasts into cardiomyocytes or cardiovascular progenitors. However, in studies with human cells, the lack of reporter fibroblasts has hindered the screening of factors and consequently, the development of robust direct cardiac reprogramming protocols.In this study, we have generated functional human NKX2.5GFP reporter cardiac fibroblasts. We first established a new NKX2.5GFP reporter human induced pluripotent stem cell (hiPSC) line using a CRISPR-Cas9-based knock-in approach in order to preserve function which could alter the biology of the cells. The reporter was found to faithfully track NKX2.5 expressing cells in differentiated NKX2.5GFP hiPSC and the potential of NKX2.5-GFP + cells to give rise to the expected cardiac lineages, including functional ventricular- and atrial-like cardiomyocytes, was demonstrated. Then NKX2.5GFP cardiac fibroblasts were obtained through directed differentiation, and these showed typical fibroblast-like morphology, a specific marker expression profile and, more importantly, functionality similar to patient-derived cardiac fibroblasts. The advantage of using this approach is that it offers an unlimited supply of cellular models for research in cardiac reprogramming, and since NKX2.5 is expressed not only in cardiomyocytes but also in cardiovascular precursors, the detection of both induced cell types would be possible. These reporter lines will be useful tools for human direct cardiac reprogramming research and progress in this field.

Targeting cell plasticity for regeneration: From in vitro to in vivo reprogramming

The discovery of induced pluripotent stem cells (iPSCs), reprogrammed to pluripotency from somatic cells, has transformed the landscape of regenerative medicine, disease modelling and drug discovery pipelines. Since the first generation of iPSCs in 2006, there has been enormous effort to develop new methods that increase reprogramming efficiency, and obviate the need for viral vectors. In parallel to this, the promise of in vivo reprogramming to convert cells into a desired cell type to repair damage in the body, constitutes a new paradigm in approaches for tissue regeneration. This review article explores the current state of reprogramming techniques for iPSC generation with a specific focus on alternative methods that use biophysical and biochemical stimuli to reduce or eliminate exogenous factors, thereby overcoming the epigenetic barrier towards vector-free approaches with improved clinical viability. We then focus on application of iPSC for therapeutic approaches, by giving an overview of ongoing clinical trials using iPSCs for a variety of health conditions and discuss future scope for using materials and reagents to reprogram cells in the body.