Rodrigues, C. A. V. | Search bioRxiv

bioRxiv2025

Gradient-Based Regulation of Activin A Directs Multilineage Liver Organoid Development from Human Pluripotent Stem Cells

Morphogen gradients critically regulate the coordinated emergence of endodermal and mesodermal lineages during liver bud formation, yet current human hepatic organoid models inadequately replicate these spatial cues. Here we demonstrate that precise modulation of Activin A concentrations within a dynamic 3D vertical-wheel bioreactor system enables the co-emergence and spatial organization of hepatic epithelium and septum transversum mesenchyme-like populations from human pluripotent stem cells. High Activin levels induce uniform definitive endoderm and enhanced hepatic maturation, whereas low levels promote epithelial tube-like structures encased by mesenchymal cells, recapitulating early liver diverticulum architecture. This gradient-based approach autonomously generates parenchymal and non-parenchymal hepatic lineages, providing a scalable platform to model human liver organogenesis and engineer ventral foregut-derived tissues.

bioengineering↗

bioRxiv2021

Transcriptome profiling of human pluripotent stem cell-derived cerebellar organoids reveals fastercommitment under dynamic conditions

Human induced pluripotent stem cells (iPSCs) have great potential for disease modeling. However, generating iPSC-derived models to study brain diseases remains a challenge. In particular, the ability to recapitulate cerebellar development in vitro is still limited. We presented a reproducible and scalable production of cerebellar organoids by using the novel Vertical-Wheel single-use bioreactors, in which functional cerebellar neurons were obtained. Here, we evaluate the global gene expression profiles by RNA sequencing (RNA-seq) across cerebellar differentiation, demonstrating a faster cerebellar commitment in this novel dynamic differentiation protocol. Furthermore, transcriptomic profiles suggest a significant enrichment of extracellular matrix (ECM) in dynamic-derived cerebellar organoids, which can better mimic the neural microenvironment and support a consistent neuronal network. Thus, an efficient generation of organoids with cerebellar identity was achieved for the first time in a continuous process using a dynamic system without the need of organoids encapsulation in ECM-based hydrogels, allowing the possibility of large-scale production and application in high-throughput processes. The presence of factors that favors angiogenesis onset was also detected in dynamic condition, which can enhance functional maturation of cerebellar organoids. We anticipate that large-scale production of cerebellar organoids may help developing models for drug screening, toxicological tests and studying pathological pathways involved in cerebellar degeneration.

bioengineering↗