Mitochondrial dysfunction-induced KDM5A degradation impairs adult hippocampal neurogenesis in Alzheimer’s disease

2020 ◽  
Author(s):  
Dong Kyu Kim ◽  
Hyobin Jeong ◽  
Jingi Bae ◽  
Moon-Yong Cha ◽  
Moonkyung Kang ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Mitochondrial Dysfunction ◽  
Progenitor Cells ◽  
Neuronal Differentiation ◽  
Neural Progenitor Cells ◽  
Neural Progenitor ◽  
Hippocampal Neurogenesis ◽  
Adult Hippocampal Neurogenesis ◽  
Amyloid Pathology ◽  
Neural Stem Progenitor Cells

Abstract Background Adult hippocampal neurogenesis (AHN) is a process of continuously generating functional mature neurons from neural stem cells in the dentate gyrus. In Alzheimer’s disease (AD) brains, amyloid pathology has deleterious effects on AHN, but molecular mechanisms for dysregulated AHN are unclear. Mitochondria of neural stem/progenitor cells play crucial roles in determining cell fate. Since mitochondrial dysfunction by amyloid pathology is the typical symptom of AD pathogenesis, we aim to study whether mitochondrial dysfunction of neural stem/progenitor cells by amyloid pathology causes the impairment of AHN, and elucidate the molecular mechanism of the phenomenon. Methods To investigate the effect of mitochondrial dysfunction of neural stem/progenitor cells on neuronal differentiation, we expressed mitochondria-targeted amyloid beta (mitoAβ) in neural stem/progenitor cells in vitro and in vivo. Proteomic analysis of the hippocampal tissue implicated mitochondrial dysfunction by mitoAβ as a cause of AHN deficits. We identified epigenetic regulators of neural progenitor cells that are regulated by mitoAβ expression or drug-induced mitochondrial toxicity and proposed a link between mitochondria and AHN. Results Amyloid pathology characteristically inhibited the neuronal differentiation stage, not the proliferation of neural stem/progenitor cells during AHN in early AD model mice. Mitochondrial dysfunction in neural stem/progenitor cells by expressing mitoAβ inhibited the neuronal differentiation and AHN with cognitive impairment. Mechanistic studies revealed that lysine demethylase 5A (KDM5A) was involved in the neuronal differentiation and could be degraded by mitochondrial dysfunction in neural progenitor cells, thereby inhibiting the differentiation and cognitive functions. Conclusions These results reveal the new role of KDM5A as a mediator of retrograde signaling, reflecting mitochondrial status, and that the decrease of KDM5A in neural progenitor cells by mitochondrial dysfunction impairs the neuronal differentiation and AHN, finally leading to memory deficits. These findings and its relationship to mitochondrial dysfunction suggest that mitochondrial failure in neural progenitor cells by amyloid pathology closely associates with reduced AHN in AD.

scholarly journals H3K9 Methyltransferases Suv39h1 and Suv39h2 Control the Differentiation of Neural Progenitor Cells in the Adult Hippocampus

2022 ◽  
Vol 9 ◽  
Author(s):  
Miguel V. Guerra ◽  
Matías I. Cáceres ◽  
Andrea Herrera-Soto ◽  
Sebastián B. Arredondo ◽  
Manuel Varas-Godoy ◽  
...  
Keyword(s):  
Dentate Gyrus ◽  
Progenitor Cells ◽  
Neuronal Differentiation ◽  
Neural Progenitor Cells ◽  
Adult Mouse ◽  
Histone H3 ◽  
Neural Progenitor ◽  
Hippocampal Neurogenesis ◽  
Adult Hippocampal Neurogenesis ◽  
Adult Hippocampus

In the dentate gyrus of the adult hippocampus new neurons are generated from neural precursor cells through different stages including proliferation and differentiation of neural progenitor cells and maturation of newborn neurons. These stages are controlled by the expression of specific transcription factors and epigenetic mechanisms, which together orchestrate the progression of the neurogenic process. However, little is known about the involvement of histone posttranslational modifications, a crucial epigenetic mechanism in embryonic neurogenesis that regulates fate commitment and neuronal differentiation. During embryonic development, the repressive modification trimethylation of histone H3 on lysine 9 (H3K9me3) contributes to the cellular identity of different cell-types. However, the role of this modification and its H3K9 methyltransferases has not been elucidated in adult hippocampal neurogenesis. We determined that during the stages of neurogenesis in the adult mouse dentate gyrus and in cultured adult hippocampal progenitors (AHPs), there was a dynamic change in the expression and distribution of H3K9me3, being enriched at early stages of the neurogenic process. A similar pattern was observed in the hippocampus for the dimethylation of histone H3 on lysine 9 (H3K9me2), another repressive modification. Among H3K9 methyltransferases, the enzymes Suv39h1 and Suv39h2 exhibited high levels of expression at early stages of neurogenesis and their expression decreased upon differentiation. Pharmacological inhibition of these enzymes by chaetocin in AHPs reduced H3K9me3 and concomitantly decreased neuronal differentiation while increasing proliferation. Moreover, Suv39h1 and Suv39h2 knockdown in newborn cells of the adult mouse dentate gyrus by retrovirus-mediated RNA interference impaired neuronal differentiation of progenitor cells. Our results indicate that H3K9me3 and H3K9 methyltransferases Suv39h1 and Suv39h2 are critically involved in the regulation of adult hippocampal neurogenesis by controlling the differentiation of neural progenitor cells.

scholarly journals Expression of progenitor cell/immature neuron markers does not present definitive evidence for adult neurogenesis

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Hideo Hagihara ◽  
Tomoyuki Murano ◽  
Koji Ohira ◽  
Miki Miwa ◽  
Katsuki Nakamura ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Neural Progenitor Cells ◽  
Adult Life ◽  
Neural Progenitor ◽  
Hippocampal Neurogenesis ◽  
Adult Hippocampal Neurogenesis ◽  
Mature Adult ◽  
Neuronal Markers ◽  
Definitive Evidence ◽  
Immature Neurons

AbstractIt is agreed upon that adult hippocampal neurogenesis (AHN) occurs in the dentate gyrus (DG) in rodents. However, the existence of AHN in humans, particularly in elderly individuals, remains to be determined. Recently, several studies reported that neural progenitor cells, neuroblasts, and immature neurons were detected in the hippocampus of elderly humans, based on the expressions of putative markers for these cells, claiming that this provides evidence of the persistence of AHN in humans. Herein, we briefly overview the phenomenon that we call “dematuration,” in which mature neurons dedifferentiate to a pseudo-immature status and re-express the molecular markers of neural progenitor cells and immature neurons. Various conditions can easily induce dematuration, such as inflammation and hyper-excitation of neurons, and therefore, the markers for neural progenitor cells and immature neurons may not necessarily serve as markers for AHN. Thus, the aforementioned studies have not presented definitive evidence for the persistence of hippocampal neurogenesis throughout adult life in humans, and we would like to emphasize that those markers should be used cautiously when presented as evidence for AHN. Increasing AHN has been considered as a therapeutic target for Alzheimer’s disease (AD); however, given that immature neuronal markers can be re-expressed in mature adult neurons, independent of AHN, in various disease conditions including AD, strategies to increase the expression of these markers in the DG may be ineffective or may worsen the symptoms of such diseases.

scholarly journals Capicua regulates the development of adult-born neurons in the hippocampus

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Brenna Hourigan ◽  
Spencer D. Balay ◽  
Graydon Yee ◽  
Saloni Sharma ◽  
Qiumin Tan
Keyword(s):  
Dentate Gyrus ◽  
Progenitor Cells ◽  
Neural Progenitor Cells ◽  
Neural Progenitor Cell ◽  
Neural Progenitor ◽  
Hippocampal Neurogenesis ◽  
Adult Hippocampal Neurogenesis ◽  
Proliferative Potential ◽  
Cell Pool ◽  
Adult Born Neurons

AbstractNew neurons continuously arise from neural progenitor cells in the dentate gyrus of the adult hippocampus to support ongoing learning and memory formation. To generate functional adult-born neurons, neural progenitor cells proliferate to expand the precursor cell pool and differentiate into neurons. Newly generated cells then undergo postmitotic maturation to migrate to their final destination and develop elaborate dendritic branching, which allows them to receive input signals. Little is known about factors that regulate neuronal differentiation, migration, and dendrite maturation during adult hippocampal neurogenesis. Here, we show that the transcriptional repressor protein capicua (CIC) exhibits dynamic expression in the adult dentate gyrus. Conditional deletion of Cic from the mouse dentate gyrus compromises the adult neural progenitor cell pool without altering their proliferative potential. We further demonstrate that the loss of Cic impedes neuronal lineage development and disrupts dendritic arborization and migration of adult-born neurons. Our study uncovers a previously unrecognized role of CIC in neurogenesis of the adult dentate gyrus.

scholarly journals A role for Lin28a in aging-associated decline of adult hippocampal neurogenesis

2022 ◽  
Author(s):  
Zhechun Hu ◽  
Jiao Ma ◽  
Huimin Yue ◽  
Xiaofang Li ◽  
Chao Wang ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Neural Progenitor Cells ◽  
Rna Binding ◽  
Functional Integration ◽  
Neural Progenitor ◽  
Hippocampal Neurogenesis ◽  
Adult Hippocampal Neurogenesis ◽  
Pattern Separation ◽  
Neurogenic Niche ◽  
Newborn Neurons

Hippocampal neurogenesis declines with aging. Wnt ligands and antagonists within the hippocampal neurogenic niche regulate the proliferation of neural progenitor cells and the development of new neurons, and the changes of their levels in the niche mediate aging-associated decline of neurogenesis. We found that RNA-binding protein Lin28a remained existent in neural progenitor cells and granule neurons in the adult hippocampus, and decreased with aging. Loss of Lin28a inhibited the responsiveness of neural progenitor cells to niche Wnt agonist and reduced neurogenesis, thus impairing pattern separation. Overexpression of Lin28a increased the proliferation of neural progenitor cells, promoted the functional integration of newborn neurons, restored neurogenesis in Wnt-deficient dentate gyrus, and rescued the impaired pattern separation in aging mice. Our data suggest that Lin28a regulates adult hippocampal neurogenesis as an intracellular mechanism by responding to niche Wnt signals, and its decrease is involved in aging-associated decline of hippocampal neurogenesis as well as related cognitive functions.

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