Biochemical and Morphological Characterization of a Neurodevelopmental Disorder-Related Mono-ADP-Ribosylhydrolase, MACRO Domain Containing 2

2018 ◽  
Vol 40 (3) ◽  
pp. 278-287 ◽  
Author(s):  
Hidenori Ito ◽  
Rika Morishita ◽  
Makoto Mizuno ◽  
Noriko Kawamura ◽  
Hidenori Tabata ◽  
...  

MACRO Domain Containing 2 (MacroD2) is a neurodevelopmental disorder-related mono-ADP-ribosylhydrolase. Molecular features of this protein in neural tissues are largely unknown. In this study, we generated a specific antibody against MacroD2, and carried out expression and morphological analyses of the molecule during mouse brain development. In Western blotting, 2 MacroD2 isoforms with molecular masses of ∼70 and ∼75 kDa started to be expressed at embryonic day 16.5, reached the maximal level at postnatal day 8, and then gradually decreased through P30. In contrast, other isoforms with molecular masses of ∼110 and ∼140 kDa gradually increased during embryonic to postnatal development. In immunohistochemical analyses, MacroD2 was strongly detected in cortical neurons in layer II–V at P0 and P7, while the protein expression decreased significantly in the neurons at P30. Immunofluorescence analyses revealed that MacroD2 was mainly distributed in the soma and to a lesser extent in the axon and dendrite of immature primary cultured mouse hippocampal neurons. On the other hand, in the matured hippocampal neurons, while MacroD2 was detected in the soma, it displayed in dendrites a punctate distribution pattern with a partial colocalization with synaptic markers, synaptophysin, and PSD95. The obtained results indicate that MacroD2 is expressed and may have a physiological role in the central nervous system during brain development.

2015 ◽  
Vol 37 (2) ◽  
pp. 131-141 ◽  
Author(s):  
Shuhong Qiao ◽  
Ramin Homayouni

Dab2IP (DOC-2/DAB2 interacting protein) is a GTPase-activating protein which is involved in various aspects of brain development in addition to its roles in tumor formation and apoptosis in other systems. In this study, we carefully examined the expression profile of Dab2IP and investigated its physiological role during brain development using a Dab2IP-knockdown (KD) mouse model created by retroviral insertion of a LacZ-encoding gene-trapping cassette. LacZ staining revealed that Dab2IP is expressed in the ventricular zone as well as the cortical plate and the intermediate zone. Immunohistochemical analysis showed that Dab2IP protein is localized in the leading process and proximal cytoplasmic regions of migrating neurons in the intermediate zone. Bromodeoxyuridine birth dating experiments in combination with immunohistochemical analysis using layer-specific markers showed that Dab2IP is important for proper positioning of a subset of layer II-IV neurons in the developing cortex. Notably, neuronal migration was not completely disrupted in the cerebral cortex of Dab2IP-KD mice and disruption of migration was not strictly layer specific. Previously, we found that Dab2IP regulates multipolar transition in cortical neurons. Others have shown that Rap1 regulates the transition from multipolar to bipolar morphology in migrating postmitotic neurons through N-cadherin signaling and somal translocation in the superficial layer of the cortical plate through integrin signaling. Therefore, we examined whether Rap1 and integrin signaling were affected in Dab2IP-KD brains. We found that Dab2IP-KD resulted in higher levels of activated Rap1 and integrin in the developing cortex. Taken together, our results suggest that Dab2IP plays an important role in the migration and positioning of a subpopulation of later-born (layers II-IV) neurons, likely through the regulation of Rap1 and integrin signaling.


2020 ◽  
Author(s):  
Mariko Noda ◽  
Hidenori Ito ◽  
Koh-ichi Nagata

Abstract WDR45 plays an essential role in the early stage of autophagy. De novo heterozygous mutations in WDR45 have been known to cause b-propeller protein-associated neurodegeneration (BPAN), a subtype of neurodegeneration with brain iron accumulation (NBIA). Although BPAN patients display global developmental delay including intellectual disability, neurodevelopmental pathophysiology of BPAN remains largely unknown. In the present study, we analyzed the physiological role of Wdr45 and pathophysiological significance of the gene abnormality during mouse brain development. Morphological and biochemical analyses revealed that Wdr45 is expressed in a developmental stage-dependent manner in mouse brain. Wdr45 was also found to be located in the excitatory synapses in biochemical fractionation. Since the WDR45 mutations are thought to cause protein degradation, we conducted acute knockdown experiments by an in utero electroporation method with mice to recapitulate the pathophysiological conditions of BPAN. Silencing of Wdr45 caused abnormal dendritic development and synaptogenesis during corticogenesis, both of which were significantly rescued by co-expression with RNAi-resistant version of Wdr45. In addition, terminal arbors of callosal axons were less developed in Wdr45-deficient cortical neurons of adult mouse when compared to the control cells. These results strongly suggest a pathophysiological significance of WDR45 gene abnormalities in neurodevelopmental aspects of BPAN.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mariko Noda ◽  
Hidenori Ito ◽  
Koh-ichi Nagata

AbstractWDR45 plays an essential role in the early stage of autophagy. De novo heterozygous mutations in WDR45 have been known to cause β-propeller protein-associated neurodegeneration (BPAN), a subtype of neurodegeneration with brain iron accumulation (NBIA). Although BPAN patients display global developmental delay with intellectual disability, the neurodevelopmental pathophysiology of BPAN remains largely unknown. In the present study, we analyzed the physiological role of Wdr45 and pathophysiological significance of the gene abnormality during mouse brain development. Morphological and biochemical analyses revealed that Wdr45 is expressed in a developmental stage-dependent manner in mouse brain. Wdr45 was also found to be located in excitatory synapses by biochemical fractionation. Since WDR45 mutations are thought to cause protein degradation, we conducted acute knockdown experiments by in utero electroporation in mice to recapitulate the pathophysiological conditions of BPAN. Knockdown of Wdr45 caused abnormal dendritic development and synaptogenesis during corticogenesis, both of which were significantly rescued by co-expression with RNAi-resistant version of Wdr45. In addition, terminal arbors of callosal axons were less developed in Wdr45-deficient cortical neurons of adult mouse when compared to control cells. These results strongly suggest a pathophysiological significance of WDR45 gene abnormalities in neurodevelopmental aspects of BPAN.


2019 ◽  
Vol 41 (1-2) ◽  
pp. 139-148 ◽  
Author(s):  
Kyoko Ibaraki ◽  
Nanako Hamada ◽  
Ikuko Iwamoto ◽  
Hidenori Ito ◽  
Noriko Kawamura ◽  
...  

POGZ is a heterochromatin protein 1 α-binding protein and regulates gene expression. On the other hand, accumulating pieces of evidence indicate that the POGZ gene abnormalities are involved in various neurodevelopmental disorders. In this study, we prepared a specific antibody against POGZ, anti-POGZ, and carried out biochemical and morphological characterization with mouse brain tissues. Western blotting analyses revealed that POGZ is expressed strongly at embryonic day 13 and then gradually decreased throughout the brain development process. In immunohistochemical analyses, POGZ was found to be enriched in cerebrocortical and hippocampal neurons in the early developmental stage. The nuclear expression was also detected in Purkinje cells in cerebellum at postnatal day (P)7 and P15 but disappeared at P30. In primary cultured hippocampal neurons, while POGZ was distributed mainly in the nucleus, it was also visualized in axon and dendrites with partial localization at synapses in consistency with the results obtained in biochemical fractionation analyses. The obtained results suggest that POGZ takes part in the regulation of synaptic function as well as gene expression during brain development.


2015 ◽  
Vol 112 (34) ◽  
pp. E4697-E4706 ◽  
Author(s):  
Bin Tang ◽  
Tingting Wang ◽  
Huida Wan ◽  
Li Han ◽  
Xiaoyan Qin ◽  
...  

Fragile X syndrome (FXS) is an X-linked neurodevelopmental disorder characterized by severe intellectual disability and other symptoms including autism. Although caused by the silencing of a single gene, Fmr1 (fragile X mental retardation 1), the complexity of FXS pathogenesis is amplified because the encoded protein, FMRP, regulates the activity-dependent translation of numerous mRNAs. Although the mRNAs that associate with FMRP have been extensively studied, little is known regarding the proteins whose expression levels are altered, directly or indirectly, by loss of FMRP during brain development. Here we systematically measured protein expression in neocortical synaptic fractions from Fmr1 knockout (KO) and wild-type (WT) mice at both adolescent and adult stages. Although hundreds of proteins are up-regulated in the absence of FMRP in young mice, this up-regulation is largely diminished in adulthood. Up-regulated proteins included previously unidentified as well as known targets involved in synapse formation and function and brain development and others linked to intellectual disability and autism. Comparison with putative FMRP target mRNAs and autism susceptibility genes revealed substantial overlap, consistent with the idea that the autism endophenotype of FXS is due to a “multiple hit” effect of FMRP loss, particularly within the PSD95 interactome. Through studies of de novo protein synthesis in primary cortical neurons from KO and WT mice, we found that neurons lacking FMRP produce nascent proteins at higher rates, many of which are synaptic proteins and encoded by FMRP target mRNAs. Our results provide a greatly expanded view of protein changes in FXS and identify age-dependent effects of FMRP in shaping the neuronal proteome.


2021 ◽  
Vol 65 (s1) ◽  
Author(s):  
Andrea Conz ◽  
Clara Alice Musi ◽  
Luca Russo ◽  
Tiziana Borsello ◽  
Luca Colnaghi

The SUMOylation machinery is a regulator of neuronal activity and synaptic plasticity. It is composed of SUMO isoforms and specialized enzymes named E1, E2 and E3 SUMO ligases. Recent studies have highlighted how SUMO isoforms and E2 enzymes localize with synaptic markers to support previous functional studies but less information is available on E3 ligases. PIAS proteins - belonging to the protein inhibitor of activated STAT (PIAS) SUMO E3-ligase family - are the best-characterized SUMO E3-ligases and have been linked to the formation of spatial memory in rodents. Whether however they exert their function co-localizing with synaptic markers is still unclear. In this study, we applied for the first time structured illumination microscopy (SIM) to PIAS ligases to investigate the co-localization of PIAS1 and PIAS3 with synaptic markers in hippocampal and cortical murine neurons. The results indicate partial co-localization of PIAS1 and PIAS3 with synaptic markers in hippocampal neurons and much rarer occurrence in cortical neurons. This is in line with previous super-resolution reports describing the co-localization with synaptic markers of other components of the SUMOylation machinery.


Genes ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 470
Author(s):  
Jeremy W. Prokop ◽  
Caleb P. Bupp ◽  
Austin Frisch ◽  
Stephanie M. Bilinovich ◽  
Daniel B. Campbell ◽  
...  

Ornithine decarboxylase 1 (ODC1 gene) has been linked through gain-of-function variants to a rare disease featuring developmental delay, alopecia, macrocephaly, and structural brain anomalies. ODC1 has been linked to additional diseases like cancer, with growing evidence for neurological contributions to schizophrenia, mood disorders, anxiety, epilepsy, learning, and suicidal behavior. The evidence of ODC1 connection to neural disorders highlights the need for a systematic analysis of ODC1 genotype-to-phenotype associations. An analysis of variants from ClinVar, Geno2MP, TOPMed, gnomAD, and COSMIC revealed an intellectual disability and seizure connected loss-of-function variant, ODC G84R (rs138359527, NC_000002.12:g.10444500C > T). The missense variant is found in ~1% of South Asian individuals and results in 2.5-fold decrease in enzyme function. Expression quantitative trait loci (eQTLs) reveal multiple functionally annotated, non-coding variants regulating ODC1 that associate with psychiatric/neurological phenotypes. Further dissection of RNA-Seq during fetal brain development and within cerebral organoids showed an association of ODC1 expression with cell proliferation of neural progenitor cells, suggesting gain-of-function variants with neural over-proliferation and loss-of-function variants with neural depletion. The linkage from the expression data of ODC1 in early neural progenitor proliferation to phenotypes of neurodevelopmental delay and to the connection of polyamine metabolites in brain function establish ODC1 as a bona fide neurodevelopmental disorder gene.


Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 324
Author(s):  
Matthias Deutsch ◽  
Anne Günther ◽  
Rodrigo Lerchundi ◽  
Christine R. Rose ◽  
Sabine Balfanz ◽  
...  

Uncovering the physiological role of individual proteins that are part of the intricate process of cellular signaling is often a complex and challenging task. A straightforward strategy of studying a protein’s function is by manipulating the expression rate of its gene. In recent years, the Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR)/Cas9-based technology was established as a powerful gene-editing tool for generating sequence specific changes in proliferating cells. However, obtaining homogeneous populations of transgenic post-mitotic neurons by CRISPR/Cas9 turned out to be challenging. These constraints can be partially overcome by CRISPR interference (CRISPRi), which mediates the inhibition of gene expression by competing with the transcription machinery for promoter binding and, thus, transcription initiation. Notably, CRISPR/Cas is only one of several described approaches for the manipulation of gene expression. Here, we targeted neurons with recombinant Adeno-associated viruses to induce either CRISPRi or RNA interference (RNAi), a well-established method for impairing de novo protein biosynthesis by using cellular regulatory mechanisms that induce the degradation of pre-existing mRNA. We specifically targeted hyperpolarization-activated and cyclic nucleotide-gated (HCN) channels, which are widely expressed in neuronal tissues and play essential physiological roles in maintaining biophysical characteristics in neurons. Both of the strategies reduced the expression levels of three HCN isoforms (HCN1, 2, and 4) with high specificity. Furthermore, detailed analysis revealed that the knock-down of just a single HCN isoform (HCN4) in hippocampal neurons did not affect basic electrical parameters of transduced neurons, whereas substantial changes emerged in HCN-current specific properties.


2006 ◽  
Vol 295 (1) ◽  
pp. 405
Author(s):  
Steve Asmus ◽  
Mark Ball ◽  
Angela Bohnen ◽  
Kevin Phelps ◽  
Cindy Hartley ◽  
...  

2007 ◽  
Vol 27 (20) ◽  
pp. 7113-7124 ◽  
Author(s):  
Yves Jossin ◽  
André M. Goffinet

ABSTRACT Reelin is an extracellular matrix protein with various functions during development and in the mature brain. It activates different signaling cascades in target cells, one of which is the phosphatidylinositol 3-kinase (PI3K) pathway, which we investigated further using pathway inhibitors and in vitro brain slice and neuronal cultures. We show that the mTor (mammalian target of rapamycin)-S6K1 (S6 kinase 1) pathway is activated by Reelin and that this depends on Dab1 (Disabled-1) phosphorylation and activation of PI3K and Akt (protein kinase B). PI3K and Akt are required for the effects of Reelin on the organization of the cortical plate, but their downstream partners mTor and glycogen synthase kinase 3β (GSK3β) are not. On the other hand, mTor, but not GSK3β, mediates the effects of Reelin on the growth and branching of dendrites of hippocampal neurons. In addition, PI3K fosters radial migration of cortical neurons through the intermediate zone, an effect that is independent of Reelin and Akt.


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