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Raivio, T.

Publications and source records attributed to Raivio, T..

3 recordsLinked to original sources

Differentiation of KISS1-Expressing Cells from Human Pluripotent Stem Cells: Many Roads To Rome

Introduction Kisspeptin-secreting (Kiss) neurons govern human puberty and reproduction. In the arcuate nucleus (ARC), they control pulsatile release of gonadotropin-releasing hormone (GnRH), while Kiss neurons in the preoptic area (POA) control GnRH surge. Since animal models do not fully recapitulate the human phenotype, a human model to study these neurons is crucial. Methods We differentiated human pluripotent stem cells (hPSCs) into neuron cultures using two distinct strategies: FGF8 protocol, consisting of dual SMAD inhibition (dSMADi), FGF8b, and Notch inhibition; and SHH protocol, consisting of dSMADi and SHH activation, followed by Notch inhibition. Neuron cultures obtained on day 45 were characterized at the mRNA level using RT-qPCR. Results Both strategies resulted in neuron cultures where significant KISS1 expression could be detected. SHH-derived neuron cultures expressed high NKX2-1 and the ARC markers POMC, NHLH2, and NR5A2, while FGF8-derived neuron cultures expressed low NKX2-1 and the anterior POA marker FOXG1. Conclusions We provide the first ever strategies to differentiate hPSCs into neuron cultures that express KISS1. Future studies providing in depth transcriptomic, protein, and functional characterization are needed to establish the properties of these models.

neuroscience↗

One-step generation of auxin-inducible degron cells with high-efficiency homozygous tagging

Auxin-inducible degron (AID) technology is powerful for chemogenetic control of proteolysis. However, generation of human cell lines to deplete endogenous proteins with AID remains challenging. Typically, homozygous degron-tagging efficiency is low and overexpression of an auxin receptor requires additional engineering steps. Here, we establish a one-step genome editing procedure with high-efficiency homozygous tagging and auxin receptor expression. We demonstrate its application in 5 human cell lines, including embryonic stem (ES) cells. The method allowed isolation of AID single-cell clones in 10 days for 11 target proteins with >80% average homozygous degron-tagging efficiency in A431 cells, and >50% efficiency for 5 targets in H9 ES cells. The tagged endogenous proteins were inducibly degraded in all cell lines, including ES cells and ES-cell derived neurons, with robust expected functional readouts. This method facilitates the application of AID for studying endogenous protein functions in human cells, especially in stem cells.

cell biology↗

WDR11-mediated Hedgehog signalling defects underlie a new ciliopathy related to Kallmann syndrome

WDR11 has been implicated in congenital hypogonadotropic hypogonadism (CHH) and Kallmann syndrome (KS), human developmental genetic disorders defined by delayed puberty and infertility. However, WDR11s role in development is poorly understood. Here we report that WDR11 modulates the Hedgehog (Hh) signalling pathway and is essential for ciliogenesis. Disruption of WDR11 expression in mouse and zebrafish results in phenotypic characteristics associated with defective Hh signalling, accompanied by dysgenesis of ciliated tissues. Wdr11 null mice also exhibit early onset obesity. We found that WDR11 shuttles from the cilium to the nucleus in response to Hh signalling. WDR11 was also observed to regulate the proteolytic processing of GLI3 and cooperate with EMX1 transcription factor to induce the expression of downstream Hh pathway genes and gonadotrophin releasing hormone production. The CHH/KS-associated human mutations result in loss-of-function of WDR11. Treatment with the Hh agonist purmorphamine partially rescued the WDR11-haploinsufficiency phenotypes. Our study reveals a novel class of ciliopathy caused by WDR11 mutations and suggests that CHH/KS may be a part of the human ciliopathy spectrum.

developmental biology↗