Despite recent advances in biomedical sciences, treatment options remain limited for patients suffering from stroke or other forms of brain injuries. Endogenous regenerative capacities in the brain hold therapeutic promise for nervous system repair after disease and injury. Throughout embryonic and postnatal development, neural progenitors/stem cells give rise to differentiated neurons, astrocytes, and oligodendrocytes. While these progenitors are relatively abundant during embryogenesis, they become restricted to specialized regions in the adult brain. In contrast to the well-investigated area of adult neural stem cell biology, relatively little is known about the cellular and molecular mechanisms controlling multiciliated ependymal cell (EC) function. As a primary cell type lining the adult brain ventricles, ECs form an important part of the lateral ventricular neurogenic niche, but their roles in postnatal/adult neurogenesis have long been controversial: whether ECs represent a neurogenic source remains unclear. Beyond ciliary movements, we know relatively little about basic ependymal biology. Using a combination of mouse genetics, biochemistry, and multiphoton live-imaging, we plan to elucidate the steps necessary to induce and control ependymal cellular plasticity. Our proposal is centered on basic molecular discoveries: we found that expression of the Foxj1 transcription factor, necessary for EC development from radial glial progenitors, is kept inherently unstable in mature ECs. Moreover, continued Foxj1 expression is required to prevent mature ECs from de-differentiating back into a progenitor-like state. We found that this surprising intrinsic cellular instability of mature ECs can be controlled by inhibitor of NF-?B kinase (IKK) signaling, a novel pathway distinct from cannonical NF-?B control. We plan to further explore these unexpected observations by determining the following: 1) whether the non- canonical IKK signal transduction pathway in ECs integrates extracellular signals to determine EC phenotypic stability; 2) what are the molecular mechanisms regulating Foxj1 transcription factor stability and proteolytic degradation - signaling cascades required to initiate EC de-differentiation; and 3) whether molecular events initiating de-differentiation of ECs represent the first steps toward their neurogenic transformation. Tackling the poorly-understood basic molecular and cellular mechanisms regulating EC biology, and using them as a basis for solving a long-standing problem on ependymal contributions to postnatal/adult neurogenesis, should further our understanding of CNS regenerative capacities in health and disease.

Public Health Relevance

Our nervous system is critically important for learning, memory, and our perception of the world around us. Injuries to the nervous system are often debilitating, and difficult to treat since neurons do not regenerate themselves. This proposal examines the basic cellular biology of poorly understood multiciliated ependymal cells in the brain, and whether their unexpected properties can be utilized for regeneration.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
2R01NS078192-06A1
Application #
9473124
Study Section
Special Emphasis Panel (ZRG1)
Program Officer
Lavaute, Timothy M
Project Start
2012-03-01
Project End
2022-08-31
Budget Start
2017-09-01
Budget End
2018-08-31
Support Year
6
Fiscal Year
2017
Total Cost
Indirect Cost
Name
Duke University
Department
Anatomy/Cell Biology
Type
Schools of Medicine
DUNS #
044387793
City
Durham
State
NC
Country
United States
Zip Code
27705
Abdi, Khadar; Lai, Chun-Hsiang; Paez-Gonzalez, Patricia et al. (2018) Uncovering inherent cellular plasticity of multiciliated ependyma leading to ventricular wall transformation and hydrocephalus. Nat Commun 9:1655
Káradóttir, Ragnhildur T; Kuo, Chay T (2018) Neuronal Activity-Dependent Control of Postnatal Neurogenesis and Gliogenesis. Annu Rev Neurosci 41:139-161
Abdi, Khadar; Kuo, Chay T (2018) Laminating the mammalian cortex during development: cell polarity protein function and Hippo signaling. Genes Dev 32:740-741
Asrican, Brent; Paez-Gonzalez, Patricia; Erb, Joshua et al. (2016) Cholinergic Circuit Control of Postnatal Neurogenesis. Neurogenesis (Austin) 3:
Chaboub, Lesley S; Manalo, Jeanne M; Lee, Hyun Kyoung et al. (2016) Temporal Profiling of Astrocyte Precursors Reveals Parallel Roles for Asef during Development and after Injury. J Neurosci 36:11904-11917
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Lyons, Gray R; Andersen, Ryan O; Abdi, Khadar et al. (2014) Cysteine proteinase-1 and cut protein isoform control dendritic innervation of two distinct sensory fields by a single neuron. Cell Rep 6:783-791
Paez-Gonzalez, Patricia; Asrican, Brent; Rodriguez, Erica et al. (2014) Identification of distinct ChAT? neurons and activity-dependent control of postnatal SVZ neurogenesis. Nat Neurosci 17:934-42
Wang, Wenbin; Pan, Yung-Wei; Wietecha, Tomasz et al. (2013) Extracellular signal-regulated kinase 5 (ERK5) mediates prolactin-stimulated adult neurogenesis in the subventricular zone and olfactory bulb. J Biol Chem 288:2623-31

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