ORCID Profile
0000-0002-8164-9762
Current Organisation
Columbia University
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Publisher: MyJove Corporation
Date: 23-05-2013
DOI: 10.3791/50415
Publisher: American Association for the Advancement of Science (AAAS)
Date: 19-07-2013
Publisher: Elsevier BV
Date: 07-2018
DOI: 10.1016/J.DEVCEL.2018.06.005
Abstract: Neural stem cells (NSCs) constitute an endogenous reservoir for neurons that could potentially be harnessed for regenerative therapies in disease contexts such as neurodegeneration. However, in Alzheimer's disease (AD), NSCs lose plasticity and thus possible regenerative capacity. We investigate how NSCs lose their plasticity in AD by using starPEG-heparin-based hydrogels to establish a reductionist 3D cell-instructive neuro-microenvironment that promotes the proliferative and neurogenic ability of primary and induced human NSCs. We find that administration of AD-associated Amyloid-β42 causes classical neuropathology and h ers NSC plasticity by inducing kynurenic acid (KYNA) production. Interleukin-4 restores NSC proliferative and neurogenic ability by suppressing the KYNA-producing enzyme Kynurenine aminotransferase (KAT2), which is upregulated in APP/PS1dE9 mouse model of AD and in postmortem human AD brains. Thus, our culture system enables a reductionist investigation of regulation of human NSC plasticity for the identification of potential therapeutic targets for intervention in AD.
Publisher: Cold Spring Harbor Laboratory
Date: 17-02-2021
DOI: 10.1101/2021.02.17.431442
Abstract: Motile cilia defects impair cerebrospinal fluid (CSF) flow, and can cause brain and spine disorders. To date, the development of ciliated cells, their impact on CSF flow and their function in brain and axial morphogenesis are not fully understood. Here, we have characterized motile ciliated cells within the zebrafish brain ventricles. We show that the ventricular surface undergoes significant restructuring through development, involving a transition from mono- to multiciliated cells (MCCs) driven by gmnc. MCCs are translationally polarized, co-exist with monociliated cells and generate directional flow patterns. Moreover, these ciliated cells have different developmental origins, and are genetically heterogenous with respect to expression of the Foxj1 family of ciliary master regulators. Finally, we show that cilia loss from specific brain regions or global perturbation of multiciliation does not affect overall brain or spine morphogenesis, but results in enlarged ventricles. Our findings establish that motile ciliated cells are generated by complementary and sequential transcriptional programs to support ventricular development.
Publisher: Elsevier BV
Date: 12-2012
DOI: 10.1016/J.DEVCEL.2012.10.014
Abstract: The adult zebrafish brain, unlike mammalian counterparts, can regenerate after injury owing to the neurogenic capacity of stem cells with radial glial character. We hypothesized that injury-induced regenerative programs might be turned on after injury in zebrafish brain and enable regenerative neurogenesis. Here we identify one such gene-the transcription factor gata3-which is expressed only after injury in different zebrafish organs. Gata3 is required for reactive proliferation of radial glia cells, subsequent regenerative neurogenesis, and migration of the newborn neurons. We found that these regeneration-specific roles of Gata3 are dependent on the injury because Gata3 overexpression in the unlesioned adult zebrafish brain is not sufficient to induce neurogenesis. Thus, gata3 acts as a specific injury-induced proregenerative factor that is essential for the regenerative capacity in vertebrates.
Publisher: Wiley
Date: 10-02-2012
DOI: 10.1002/DNEU.20918
Abstract: Adult neurogenesis is a widespread trait of vertebrates however, the degree of this ability and the underlying activity of the adult neural stem cells differ vastly among species. In contrast to mammals that have limited neurogenesis in their adult brains,zebrafish can constitutively produce new neurons along the whole rostrocaudal brain axis throughout its life.This feature of adult zebrafish brain relies on the presence of stem rogenitor cells that continuously proliferate,and the permissive environment of zebrafish brain for neurogenesis. Zebrafish has also an extensive regenerative capacity, which manifests itself in responding to central nervous system injuries by producing new neurons to replenish the lost ones. This ability makes zebrafish a useful model organism for understanding the stem cell activity in the brain, and the molecular programs required for central nervous system regeneration.In this review, we will discuss the current knowledge on the stem cell niches, the characteristics of the stem rogenitor cells, how they are regulated and their involvement in the regeneration response of the adult zebrafish brain. We will also emphasize the open questions that may help guide the future research.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 07-12-2012
Abstract: The zebrafish brain is much more adept than the human brain at recovering after traumatic injury. Kyritsis et al. (p. 1353 , published online 8 November see the Perspective by Stella ) investigated the cellular events that support regeneration in the zebrafish brain. Although inflammation is part of the response in both settings, the zebrafish brain goes on to initiate proliferation of replacement neurons. By inciting inflammation without neuronal damage, radial glial cells could be pushed into neurogenesis.
Publisher: Elsevier BV
Date: 10-2021
Publisher: Cold Spring Harbor Laboratory
Date: 27-11-2017
DOI: 10.1101/225243
Abstract: Three-dimensional models of human neural development and neurodegeneration are crucial when exploring stem-cell-based regenerative therapies in a tissue-mimetic manner. However, existing 3D culture systems are not sufficient to model the inherent plasticity of NSCs due to their ill-defined composition and lack of controllability of the physical properties. Adapting a glycosaminoglycan-based, cell-responsive hydrogel platform, we stimulated primary and induced human neural stem cells (NSCs) to manifest neurogenic plasticity and form extensive neuronal networks in vitro . The 3D cultures exhibited neurotransmitter responsiveness, electrophysiological activity, and tissue-specific extracellular matrix (ECM) deposition. By whole transcriptome sequencing, we identified that 3D cultures express mature neuronal markers, and reflect the in vivo make-up of mature cortical neurons compared to 2D cultures. Thus, our data suggest that our established 3D hydrogel culture supports the tissue-mimetic maturation of human neurons. We also exemplarily modeled neurodegenerative conditions by treating the cultures with Aβ42 peptide and observed the known human pathological effects of Alzheimer’s disease including reduced NSC proliferation, impaired neuronal network formation, synaptic loss and failure in ECM deposition as well as elevated Tau hyperphosphorylation and formation of neurofibrillary tangles. We determined the changes in transcriptomes of primary and induced NSC-derived neurons after Aβ42, providing a useful resource for further studies. Thus, our hydrogel-based human cortical 3D cell culture is a powerful platform for studying various aspects of neural development and neurodegeneration, as exemplified for Aβ42 toxicity and neurogenic stem cell plasticity. Neural stem cells (NSC) are reservoir for new neurons in human brains, yet they fail to form neurons after neurodegeneration. Therefore, understanding the potential use of NSCs for stem cell-based regenerative therapies requires tissue-mimetic humanized experimental systems. We report the adaptation of a 3D bio-instructive hydrogel culture system where human NSCs form neurons that later form networks in a controlled microenvironment. We also modeled neurodegenerative toxicity by using Amyloid-beta4 peptide, a hallmark of Alzheimer’s disease, observed phenotypes reminiscent of human brains, and determined the global gene expression changes during development and degeneration of neurons. Thus, our reductionist humanized culture model will be an important tool to address NSC plasticity, neurogenicity, and network formation in health and disease.
No related grants have been discovered for Caghan Kizil.