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Sousa-Luis, R.

Publications and source records attributed to Sousa-Luis, R..

2 recordsLinked to original sources

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

Point Technology Illuminates The Processing Of Polymerase-Associated Intact Nascent Transcripts

Mammalian chromatin is the site of both RNA polymerase II (Pol II) transcription and coupled RNA processing. However, molecular details of such co-transcriptional mechanisms remain obscure, partly due to technical limitations in purifying authentic nascent transcripts. We present a new approach to purify and profile nascent RNA, called Polymerase Intact Nascent Transcript (POINT) technology. This three-pronged methodology maps nascent RNA 5ends (POINT-5), establishes the kinetics of co-transcriptional splicing patterns (POINT-nano) and profiles whole transcription units (POINT-seq). In particular we show by depletion of the nuclear exonuclease Xrn2 that this activity acts selectively on cleaved 5P-RNA at polyadenylation sites. Furthermore POINT-nano reveals that splicing occurs either immediately after splice site transcription or is delayed until Pol II transcribes downstream sequences. Finally, we connect RNA cleavage and splicing with either premature or full-length transcript termination. We anticipate that POINT technology will afford full dissection of the complexity of co-transcriptional RNA processing. HIGHLIGHTSO_LIPOINT methodology dissects intact nascent RNA processing C_LIO_LISpecificity of Xrn2 exonuclease in co-transcriptional RNA degradation C_LIO_LISplicing suppresses Xrn2-dependent premature termination C_LIO_LIDifferent kinetic classes of co-transcriptional splicing in human genes C_LI

genomics