OC 69.4 - Synthetic microRNA switch technology enables to detect the immune-biased megakaryocytes from heterogenous iPSC-derived megakaryocyte progenitor cell lines

Tuesday, July 12, 2022

3:30 PM – 3:45 PM

Location: ExCel Center, ICC Capital Suite Room 1

Presentation Format: Virtual

Presenting Author(s)

Si Jing Chen, PhD

Postdoctoral researcher
Kyoto University
Kyoto, Kyoto, Japan

Co-Author(s)

AY

Akinori Yuzuriha

Postdoctoral researcher
Kyoto University
Kyoto, Kyoto, Japan
KF

Kosuke Fujio

Researcher
Kyoto University
Kyoto, Kyoto, Japan
KH

Kazuya Hashimoto

Researcher
Kyoto University
Kyoto, Kyoto, Japan
YF

Yoshihiko Fujita

Assistant professor
Kyoto University
Kyoto, Kyoto, Japan
SP

Sudip K. Paul

PhD candidate
Chiba University
Chiba, Chiba, Japan
NT

Naoya Takayama

Associate professor
Chiba University
Chiba, Chiba, Japan
TY

Takuya Yamamoto

Associate professor
Kyoto University
Kyoto, Kyoto, Japan
NS

Naoshi Sugimoto

Associate Professor
Center for iPS Cell Research and Application, Kyoto University
Kyoto, Kyoto, Japan
HS

Hirohide Saito

Professor
Kyoto University
Kyoto, Kyoto, Japan
KE

Koji Eto

professor
Center for iPS Cell Research and Application, Kyoto University
Kyoto, Kyoto, Japan

Background: Platelets play roles in not only hemostasis but also innate immunity. It has also been suggested that megakaryocytes (MKs) per se can be distinguished into hemostasis-biased and immune-biased populations. Meanwhile, although the expression levels of several microRNAs (miRNAs) are studied in thrombopoiesis and megakaryopoiesis, there is no study based on the activities of miRNAs. We developed a miRNA switch technology which reflects the endogenous activity of miRNA and exemplified to be useful for specific cell isolation (Miki, et al. Cell Stem Cell, 2015).

Aims: By using miRNA switch, we sought to examined whether iPSC-derived immortalized MK progenitor cell lines (imMKCLs), useful for ex vivo manufacturing of platelets applicable to human patients (Ito, et al. Cell, 2018; Sugimoto, et al. ASH abstract, 2021), contain immune-biased MKs.

Methods: We applied miRNA switch library screening to imMKCLs and focused on those displaying broadly separated populations. The subpopulations were subsequently subjected to RNA sequencing analysis.

Results: According to the screening, we identified two subpopulations with differential activity of let-7a-5p and let-7g-5p in the proliferation phase of imMKCLs. Unexpectedly, the bulk RNA-seq analysis of two subpopulations at proliferation and maturation stages revealed that the let-7 low-responsive (let-7 low) imMKCLs exhibited an immune-skewed transcriptional signatures. TNF signaling was found to significantly enriched in let-7 low imMKCLs in both stages. In the maturation stage, interferon responsive gene set was significantly enriched in let-7 low imMKCLs, while platelet activation signaling was enriched in let-7 high imMKCLs. In addition, the let-7 low hESC-derived CD34+ hematopoietic progenitor cells also exhibited a similar immune-skewed signature. While lung MKs are reported to exhibit immune-skewed gene expression signatures, our study revealed that the immune-skewed subpopulations also exist in iPSC/ESC-derived MKs.

Conclusion(s): We found that let-7 miRNA switches enabled to identify a subpopulation with immune properties in imMKCLs derived from iPSCs.