Partial Reprogramming of Pluripotent Stem Cell-Derived Cardiomyocytes into Neurons

Abstract

Direct reprogramming of somatic cells has been demonstrated, however, it is unknown whether electrophysiologically-active somatic cells derived from separate germ layers can be interconverted. We demonstrate that partial direct reprogramming of mesoderm-derived cardiomyocytes into neurons is feasible, generating cells exhibiting structural and electrophysiological properties of both cardiomyocytes and neurons. Human and mouse pluripotent stem cell-derived CMs (PSC-CMs) were transduced with the neurogenic transcription factors Brn2, Ascl1, Myt1l and NeuroD. We found that CMs adopted neuronal morphologies as early as day 3 post-transduction while still retaining a CM gene expression profile. At week 1 post-transduction, we found that reprogrammed CMs expressed neuronal markers such as Tuj1, Map2, and NCAM. At week 3 post-transduction, mature neuronal markers such as vGlut and synapsin were observed. With single-cell qPCR, we temporally examined CM gene expression and observed increased expression of neuronal markers Dcx, Map2, and Tubb3. Patch-clamp analysis confirmed the neuron-like electrophysiological profile of reprogrammed CMs. This study demonstrates that PSC-CMs are amenable to partial neuronal conversion, yielding a population of cells exhibiting features of both neurons and CMs.

BRN2, a POUerful driver of melanoma phenotype switching and metastasis

“…This is due to the flexible linker between the two subdomains and allows for homodimerization of POU proteins to sites in palindromic octamer recognition elements (PORE) or heterodimerization with other POU proteins on more palindromic octamer recognition elements (MORE) with noncooperative binding sites also recognized (NORE). BRN2 knock out models have demonstrated its importance in the development of the pituitary gland and hypothalamus (Schonemann et al., ), and it has also been shown that BRN2 expression, along with two other transcription factors ASCL1 and MYT1L, can convert both fibroblasts and human pluripotent stem cells into fully functional neurons (Chuang et al., ; Pfisterer et al., ; Vierbuchen et al., ; Wapinski et al., ). BRN2 plays a distinct role in the induction of migration within several glial and neuronal populations by binding to the promoter region and inducing the expression of the Notch ligand delta, resulting in increased Notch signalling and the maintenance of an undifferentiated motile cell phenotype (Castro et al., ).…”

Stage-specific Effects of Bioactive Lipids on Human iPSC Cardiac Differentiation and Cardiomyocyte Proliferation

“…This limited regenerative capability of the human heart has garnered significant interest in developing novel methodologies for both creating cardiomyocytes de novo and inducing proliferation in terminally differentiated cardiomyocytes. A major goal in human pluripotent stem cell research is to provide large quantities of cardiomyocytes suitable for cellular therapy in regenerative medicine 3 – 6 .…”

Next‐generation disease modeling with direct conversion: a new path to old neurons

“…Interestingly, the secondary TFs Prdm8, Bhlhe22, and Brn2, which are direct target genes of NeuroD1 in microglia, can also facilitate microglia-to-iN conversion by either inducing neuronal gene expression (Brn2) or repressing microglial genes (Bhlhe22, Prdm8) [27]. Further, cell typespecific epigenetic characteristics that pose a hurdle for direct conversion from keratinocytes also hinder conversion of human cardiomyocytes, which have been shown to only marginally convert into neurons with BAM/NeuroD1 [104]. Similarly, the development of robust protocols for iN generation from stored human blood samples has been as much anticipated as it has been challenging.…”