Zeb2 regulates myogenic differentiation in pluripotent stem cells

Skeletal muscle differentiation is triggered by a unique family of myogenic basic helix-loop-helix transcription factors, including MyoD, MRF-4, Myf-5, and Myogenin. These transcription factors bind promoters and distant regulatory regions, including E-box elements, of genes whose expression is restricted to muscle cells. Other E-box binding zinc finger proteins target the same DNA response elements, however, their function in muscle development and regeneration is still unknown. Here, we show that the transcription factor zinc finger E-box-binding homeobox 2 (Zeb2, Sip-1, Zfhx1b) is present in skeletal muscle tissues. We investigate the role of Zeb2 in skeletal muscle differentiation using genetic tools and transgenic mouse embryonic stem cells, together with single-cell RNA-sequencing and in vivo muscle engraftment capability. We show that Zeb2 over-expression has a positive impact on skeletal muscle differentiation in pluripotent stem cells and adult myogenic progenitors. We therefore propose that Zeb2 is a novel myogenic regulator and a possible target for improving skeletal muscle regeneration. The non-neural roles of Zeb2 are poorly understood

MicroRNAs promote skeletal muscle differentiation of mesodermal iPSC-derived progenitors

Muscular dystrophies (MDs) are often characterized by impairment of both skeletal and cardiac muscle. Regenerative strategies for both compartments therefore constitute a therapeutic avenue. Mesodermal iPSC-derived progenitors (MiPs) can regenerate both striated muscle types simultaneously in mice. Importantly, MiP myogenic propensity is influenced by somatic lineage retention. However, it is still unknown whether human MiPs have in vivo potential. Furthermore, methods to enhance the intrinsic myogenic properties of MiPs are likely needed, given the scope and need to correct large amounts of muscle in the MDs. Here, we document that human MiPs can successfully engraft into the skeletal muscle and hearts of dystrophic mice. Utilizing non-invasive live imaging and selectively induced apoptosis, we report evidence of striated muscle regeneration in vivo in mice by human MiPs. Finally, combining RNA-seq and miRNA-seq data, we define miRNA cocktails that promote the myogenic potential of human MiPs

Mesodermal iPSC-derived progenitor cells functionally regenerate cardiac and skeletal muscle

Conditions such as muscular dystrophies (MDs) that affect both cardiac and skeletal muscles would benefit from therapeutic strategies that enable regeneration of both of these striated muscle types. Protocols have been developed to promote induced pluripotent stem cells (iPSCs) to differentiate toward cardiac or skeletal muscle; however, there are currently no strategies to simultaneously target both muscle types. Tissues exhibit specific epigenetic alterations; therefore, source-related lineage biases have the potential to improve iPSC-driven multilineage differentiation. Here, we determined that differential myogenic propensity influences the commitment of isogenic iPSCs and a specifically isolated pool of mesodermal iPSC-derived progenitors (MiPs) toward the striated muscle lineages. Differential myogenic propensity did not influence pluripotency, but did selectively enhance chimerism of MiP-derived tissue in both fetal and adult skeletal muscle. When injected into dystrophic mice, MiPs engrafted and repaired both skeletal and cardiac muscle, reducing functional defects. Similarly, engraftment into dystrophic mice of canine MiPs from dystrophic dogs that had undergone TALEN-mediated correction of the MD-associated mutation also resulted in functional striatal muscle regeneration. Moreover, human MiPs exhibited the same capacity for the dual differentiation observed in murine and canine MiPs. The findings of this study suggest that MiPs should be further explored for combined therapy of cardiac and skeletal muscles.status: publishe

VEGF overexpressed mesoangioblasts enhance urethral and vaginal recovery following simulated vaginal birth in rats

Abstract Vaginal birth causes pelvic floor injury which may lead to urinary incontinence. Cell therapy has been proposed to assist in functional recovery. We aim to assess if intra-arterial injection of rat mesoangioblasts (MABs) and stable Vascular Endothelial Growth Factor (VEGF)-expressing MABs, improve recovery of urethral and vaginal function following simulated vaginal delivery (SVD). Female rats (n = 86) were assigned to either injection of saline (control), allogeneic-MABs (MABsallo), autologous-MABs (MABsauto) or allogeneic-MABs transduced to stably expressed VEGF (MABsallo-VEGF). One hour after SVD, 0.5 × 106 MABs or saline were injected into the aorta. Primary outcome was urethral (7d and 14d) and vaginal (14d) function; others were bioluminescent imaging for cell tracking (1, 3 and 7d), morphometry (7, 14 and 60d) and mRNAseq (3 and 7d). All MABs injected rats had external urethral sphincter and vaginal function recovery within 14d, as compared to only half of saline controls. Functional recovery was paralleled by improved muscle regeneration and microvascularization. Recovery rate was not different between MABsallo and MABsauto. MABsallo-VEGF accelerated functional recovery and increased GAP-43 expression at 7d. At 3d we detected major transcriptional changes in the urethra of both MABsallo and MABsallo-VEGF-injected animals, with upregulation of Rho/GTPase activity, epigenetic factors and dendrite development. MABSallo also upregulated transcripts that encode proteins involved in myogenesis and downregulated pro-inflammatory processes. MABsallo-VEGF also upregulated transcripts that encode proteins involved in neuron development and downregulated genes involved in hypoxia and oxidative stress. At 7d, urethras of MABsallo-VEGF-injected rats showed downregulation of oxidative and inflammatory response compared to MABSallo. Intra-arterial injection of MABsallo-VEGF enhances neuromuscular regeneration induced by untransduced MABs and accelerates the functional urethral and vaginal recovery after SVD