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Biology subjects

Miriuka, S.

Publications and source records attributed to Miriuka, S..

3 recordsLinked to original sources

SHEN-LONG, a novel cardiac regulatory locus, regulates cardiac master transcription factor NKX2-5 in pluripotent stem cell derived cardiomyocytes

Cardiac development is a finely regulated process, transforming undifferentiated cells into the specialized cell components of the heart. Super-Enhancers (SE), clusters of enhancers densely populated with transcription factors, play a central role in cell fate decisions, including cardiogenesis. In this work, we studied a cardiac SE in chr3q25.31. This locus also contains a cardiac specific long non-coding RNA: LINC00881 (LINC881). We termed this region of interest SHEN-LONG (Super Heart ENhancer and LONG non-coding LINC881), and selected it for further functional characterization. Our analysis revealed SHEN-LONG is a hotspot of cardiac kernel transcription factor binding sites. Cardiac differentiation of human iPSC with partial Knock Out of SHEN-LONG resulted in cardiomyocytes with reduced NKX2-5 expression, a master cardiac transcription factor, suggesting a significant role of SHEN-LONG in this process. Whole transcriptome sequencing of SHEN-LONG KO cardiomyocytes produced 134 differentially expressed genes located at great distances (>4Mb) emphasizing its long-range functional impact. A regulation mediated essentially by the SE and not by LINC881 was confirmed when LINC881 overexpression did not recover NKX2-5 expression. These findings provide insights into a novel NKX2-5 regulatory mechanism. The knowledge gained in this work may pave the way for advances in therapeutic interventions for cardiovascular disorders.

molecular biology↗

Single cell transfection of human induced pluripotent stem cells using a droplet-based microfluidic system.

Microfluidic tools have recently made possible many advances in biological and biomedical research. Research fields such as Physics, Engineering, Chemistry and Biology have combined to produce innovation in Microfluidics which has positively impacted on areas as diverse as nucleotide sequence, functional genomics, single-cell studies, single molecules assays, and biomedical diagnostics. Among these areas regenerative medicine and stem cells have benefited from Microfluidics due to these tools have had a profound impact on their applications. In the study, we present a high-performance droplet-based system for transfecting individual human-induced pluripotent stem cells. We show that this system has great efficiency in single cells and captured droplets, similar to other microfluidic methods and lower cost. We demonstrate that this microfluidic approach can be associated with the PiggyBac transposase-based system to increase its transfection efficiency. Our results provide a starting point for subsequent applications in more complex transfection systems, single-cell differentiation interactions, cell subpopulations, cell therapy, among other potential applications.

bioengineering↗

Analysis of the expression of PIWI-interacting RNAs during cardiac differentiation of human pluripotent stem cells

PIWI-interacting RNAs (piRNAs) are a class of non-coding RNAs initially thought to be restricted almost exclusively to germ line cells. In recent years, accumulating evidence has demonstrated that piRNAs are actually expressed in somatic cells like pluripotent, neural, cardiac and even cancer cells. However, controversy still remains around the existence and function of somatic piRNAs. Using small RNA-seq samples from H9 pluripotent stem cells differentiated to mesoderm progenitors and cardiomyocytes we identified the expression of 447 piRNAs, of which 241 were detected in pluripotency, 218 in mesoderm and 171 in cardiac cells. The majority of them originated from the sense strand of protein coding and lncRNAs genes in all stages of differentiation, though no evidences for secondary piRNAs (ping-pong loop) were found. Genes hosting piRNAs in cardiac samples were related to critical biological processes in the heart, like contraction and cardiac muscle development. Our results indicate that somatic piRNAs might have a role in fine-tuning the expression of genes involved in the differentiation of pluripotent cells to cardiomyocytes.

molecular biology↗