bioRxiv Science⌕ Search

bioRxiv · 10.1101/618330

A network of microRNAs acts to promote cell cycle exit and differentiation of human pancreatic endocrine cells

Abstract

Pancreatic endocrine cell differentiation is orchestrated by transcription factors that operate in a gene regulatory network to activate endocrine lineage genes and repress lineage-inappropriate genes. MicroRNAs (miRNAs) are important modulators of gene expression, yet their role in endocrine cell differentiation has not been explored system-wide. Here we characterize miRNA-regulatory networks active in human endocrine cell differentiation by combining small RNA sequencing, miRNA overexpression experiments, and network modeling approaches. This analysis identifies Let-7g, Let-7a, miR-200a, and miR-375 as endocrine-enriched miRNAs with high impact on driving endocrine differentiation-associated gene expression changes. These miRNAs target different sets of transcription factors, which converge on a network of genes involved in cell cycle regulation. When expressed in human embryonic stem cell-derived pancreatic progenitors these miRNAs induce cell cycle exit and promote endocrine cell differentiation. Our study delineates the role of miRNAs in human endocrine cell differentiation and identifies miRNAs that could facilitate endocrine cell reprogramming.

Source connections

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Jin, W., Mulas, F., Gaertner, B., Sui, Y., Wang, J., Zeng, C., Vinckier, N., Wang, A., Nguyen-Ngoc, K.-V., Chiou, J., Kaestner, K. H., Frazer, K., Carrano, A. C., Shih, H.-P., Sander, M.. 2019-04-25. A network of microRNAs acts to promote cell cycle exit and differentiation of human pancreatic endocrine cells. https://doi.org/10.1101/618330

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

Compartment-Resolved Matrisome Shifts During Postnatal Tendon Maturation in Mice

Tendons acquire their load-bearing capacity during the first month of postnatal growth, driven by the extensive remodeling of the extracellular matrix (ECM). While the role of specific individual components to this process have been well characterized, a comprehensive assessment of how the tendon matrisome changes during this critical window is lacking. This, in part, is due to the challenges associated with solubilization of mature ECM, which is underrepresented by conventical proteomic approaches. To address this, we performed compartment-resolved proteomics on murine Achilles and plantaris tendons at postnatal days 0 (P0), P14, and P28. Sequential extraction methods leveraged a CHAPS-soluble fraction, capturing cellular and soluble matrisome proteins, from the insoluble mature ECM fraction, solubilized by guanidine hydrochloride and hydroxylamine hydrochloride and separately analyzed by label-free quantitative LC-MS/MS. Analysis shows that the two compartments followed distinct trajectories during maturation. The insoluble matrix was dominated by collagenous proteins, which increased from 95% to over 99% of the identified signal intensity, and its composition was largely established by P14. Within the soluble matrisome compartment, collagens increased from 50% to over 60% by P14, accompanied by dynamic regulation of proteins implicated in collagen processing (P4HA1, PCOLCE), crosslinking (LOX, LOXL2), and regulators of collagen fibril assembly and growth (DCN, BGN, FMOD, THBS3, THBS4). Beyond these established regulators, we observed dynamic regulation of less-characterized fibril-associated proteoglycans (KERA, OGN, CHAD), matricellular (COMP, POSTN, MATN2), and angiogenic regulatorily proteins (SERPINF1, ECM1). Together, this work establishes a comprehensive protein-level reference for postnatal tendon maturating, provides new insights into the molecular regulation of functional tendon development.

developmental biology↗

Ferroptosis of selective progenitor cell types during embryogenesis ensures proper organ morphogenesis

Ferroptosis, a form of non-apoptotic cell death, is induced by lipid peroxidation resulting from an intracellular accumulation of labile iron (1). While apoptosis is involved in embryonic development (2), the role of ferroptosis in embryogenesis is unknown. Here, we report that the ferroptosis process occurs in the embryonic lung and kidney at mid- and late-gestation. In these tissues, pro-ferroptotic cells include subpopulations of the Sox9+ distal lung epithelial cells and the Flk1+ vascular progenitors in the kidney glomeruli. Lipidomic analysis reveals mixed lipid peroxidation as the driver for ferroptosis. The role of ferroptosis in the morphogenesis of these organs was confirmed by triple positivity of TfR1, 4-HNE and TUNEL, mitochondrial defects, cell membrane breakage, dead cell remnants, single-cell RNA-sequencing of a ferroptosis gene signature. Genetic manipulation of Gpx4, an endogenous inhibitor of ferroptosis. Further, genetic knockout or transgenic overexpression of Gpx4 affects lung and kidney development and results in cystic lungs and kidneys. Notably, conditional deletion Gpx4 results in hypoplasia of the lung epithelia and of the renal glomeruli, while transgenic overexpression of Gpx4 resulted in atelectasis with collapsed lung alveoli and hypertrophic glomeruli. Together, these findings show that ferroptosis regulates lung and kidney morphogenesis by acting in key progenitor cell populations during gestation. Supplementation of iron or polyunsaturated fatty acid during pregnancy has implications for organogenesis.

developmental biology↗

Variation in the embryonic cell lineages of Caenorhabditis elegans natural populations

Developmental variation has often been appreciated as a major phenotypic substrate of evolutionary innovation in multicellular organisms. Although quantification of developmental variation in isogenic populations has a long history, it has been difficult to accomplish across natural populations until recently. Given its invariant cell lineage, Caenorhabditis elegans represents an ideal model system for studying how natural diversity in development is expressed at the resolution of single cells, cell lineages, and the whole embryo. Using embGAN, a deep-learning pipeline that enables label-free lineage tracing without the bottleneck and potential confounding effects of generating transgenic strains, we reconstructed the early embryonic lineage of 78 embryos spanning eight genetic backgrounds, including six wild strains, and quantified cell-cycle timing with a lineage-aligned graph metric that separates global rescaling of developmental rate from localized changes in lineage structure. We found that cell-cycle timing differs reproducibly among genotypes, with between-strain variation consistently exceeding within-strain variation. The magnitude of this variation was itself genotype-specific and not correlated with levels of genetic divergence. Unlike the global shifts in the tempo of development that dominate divergence between species, these differences are predominantly in lineage patterning, changing the timing of specific divisions, and they align to cell fate. Thus, the invariant lineage of C. elegans is built on a structured, genotype-specific landscape of developmental variation, a potential source of trait variation from which drift in developmental systems can emerge.

developmental biology↗