SCA4 locus-associated gene Ronin (Thap11) increases Ataxin-1 protein levels and induces cerebellar degeneration in a mouse model of ataxia

ABSTRACTSpinocerebellar ataxias (SCAs) are a group of genetically heterogeneous inherited neurodegenerative disorders characterized by progressive ataxia and cerebellar degeneration. Here, we tested if Ronin (Thap11), a polyglutamine-containing protein encoded in a region on human chromosome 16q22.1 that has been genetically linked to SCA4, can be connected with SCA disease in a mouse model. We report that transgenic expression of Ronin in mouse cerebellar Purkinje cells leads not only histopathologically to detrimental loss of Purkinje cells but also phenotypically to the development of severe ataxia as early as 10-12 weeks after birth. Mechanistically, we find that Ronin is part of a protein complex in the cerebellum that is distinct from the one previously found in embryonic stem cells. Importantly, ectopically expressed Ronin raises the protein level of Ataxin-1 (Atxn1), the causative gene of the most common type of SCA, SCA1. Hence, our data provide evidence for a link between Ronin and SCAs, and also suggest that Ronin may be involved in the development of other neurodegenerative diseases.

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Ronin overexpression induces cerebellar degeneration in a mouse model of ataxia

Disease Models & Mechanisms ◽

10.1242/dmm.044834 ◽

2021 ◽

Vol 14 (6) ◽

Author(s):

Thomas P. Zwaka ◽

Marta Skowronska ◽

Ronald Richman ◽

Marion Dejosez

Keyword(s):

Mouse Model ◽

Ectopic Expression ◽

Embryonic Stem ◽

Transgenic Animals ◽

Cerebellar Degeneration ◽

Spinocerebellar Ataxias ◽

Binding Motifs ◽

Transgenic Expression ◽

Severe Ataxia ◽

Cerebellar Purkinje Cells

ABSTRACT Spinocerebellar ataxias (SCAs) are a group of genetically heterogeneous inherited neurodegenerative disorders characterized by progressive ataxia and cerebellar degeneration. Here, we used a mouse model to test a possible connection between SCA and Ronin (Thap11), a polyglutamine-containing transcriptional regulator encoded in a region of human chromosome 16q22.1 that has been genetically linked to SCA type 4. We report that transgenic expression of Ronin in mouse cerebellar Purkinje cells leads to detrimental loss of these cells and the development of severe ataxia as early as 10 weeks after birth. Mechanistically, we find that several SCA-causing genes harbor Ronin DNA-binding motifs and are transcriptionally deregulated in transgenic animals. In addition, ectopic expression of Ronin in embryonic stem cells significantly increases the protein level of Ataxin-1, the protein encoded by Atxn1, alterations of which cause SCA type 1. This increase is also seen in the cerebellum of transgenic animals, although the latter was not statistically significant. Hence, our data provide evidence for a link between Ronin and SCAs, and suggest that Ronin may be involved in the development of other neurodegenerative diseases.

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A relationship between cerebellar Purkinje cells and spatial working memory demonstrated in a lurcher/chimera mouse model system

Genes Brain & Behavior ◽

10.1111/j.1601-183x.2004.00067.x ◽

2004 ◽

Vol 3 (3) ◽

pp. 158-166 ◽

Cited By ~ 29

Author(s):

L. A. Martin ◽

T. Escher ◽

D. Goldowitz ◽

G. Mittleman

Keyword(s):

Working Memory ◽

Mouse Model ◽

Purkinje Cells ◽

Spatial Working Memory ◽

Model System ◽

Mouse Model System ◽

Cerebellar Purkinje Cells

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Altered synaptic and firing properties of cerebellar Purkinje cells in a mouse model of ARSACS

The Journal of Physiology ◽

10.1113/jp275902 ◽

2018 ◽

Vol 596 (17) ◽

pp. 4253-4267 ◽

Cited By ~ 12

Author(s):

Visou Ady ◽

Brenda Toscano-Márquez ◽

Moushumi Nath ◽

Philip K. Chang ◽

Jeanette Hui ◽

...

Keyword(s):

Mouse Model ◽

Purkinje Cells ◽

Firing Properties ◽

Cerebellar Purkinje Cells

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SYSTEMICALLY ADMINISTERED TYPE I (“ANTI-YO”) IGG, ASSOCIATED WITH PARANEOPLASTIC CEREBELLAR DEGENERATION, IS TAKEN UP BY RAT CEREBELLAR PURKINJE CELLS IN VIVO

Journal of Neuropathology & Experimental Neurology ◽

10.1097/00005072-199305000-00245 ◽

1993 ◽

Vol 52 (3) ◽

pp. 321

Author(s):

J. E. Greenlee ◽

J. B. Burns ◽

J. W. Rose ◽

K. A. Jaeckle

Keyword(s):

Purkinje Cells ◽

Cerebellar Degeneration ◽

Paraneoplastic Cerebellar Degeneration ◽

Type I ◽

Cerebellar Purkinje Cells

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Modulation of Increased mGluR1 Signaling by RGS8 Protects Purkinje Cells From Dendritic Reduction and Could Be a Common Mechanism in Diverse Forms of Spinocerebellar Ataxia

Frontiers in Cell and Developmental Biology ◽

10.3389/fcell.2020.569889 ◽

2021 ◽

Vol 8 ◽

Cited By ~ 1

Author(s):

Qin-Wei Wu ◽

Josef P. Kapfhammer

Keyword(s):

Purkinje Cells ◽

Spinocerebellar Ataxia ◽

Common Mechanism ◽

G Protein Signaling ◽

Protein Signaling ◽

Spinocerebellar Ataxias ◽

Negative Effects ◽

The Moment ◽

Cerebellar Purkinje Cells

Spinocerebellar ataxias (SCAs) are a group of hereditary neurodegenerative diseases which are caused by diverse genetic mutations in a variety of different genes. We have identified RGS8, a regulator of G-protein signaling, as one of the genes which are dysregulated in different mouse models of SCA (e.g., SCA1, SCA2, SCA7, and SCA14). In the moment, little is known about the role of RGS8 for pathogenesis of spinocerebellar ataxia. We have studied the expression of RGS8 in the cerebellum in more detail and show that it is specifically expressed in mouse cerebellar Purkinje cells. In a mouse model of SCA14 with increased PKCγ activity, RGS8 expression was also increased. RGS8 overexpression could partially counteract the negative effects of DHPG-induced mGluR1 signaling for the expansion of Purkinje cell dendrites. Our results suggest that the increased expression of RGS8 is an important mediator of mGluR1 pathway dysregulation in Purkinje cells. These findings provide new insights in the role of RGS8 and mGluR1 signaling in Purkinje cells and for the pathology of SCAs.

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Disrupted Calcium Signaling in Animal Models of Human Spinocerebellar Ataxia (SCA)

International Journal of Molecular Sciences ◽

10.3390/ijms21010216 ◽

2019 ◽

Vol 21 (1) ◽

pp. 216 ◽

Cited By ~ 3

Author(s):

Francesca Prestori ◽

Francesco Moccia ◽

Egidio D’Angelo

Keyword(s):

Animal Models ◽

Purkinje Cell ◽

Calcium Signaling ◽

Purkinje Cells ◽

Motor Coordination ◽

Cerebellar Atrophy ◽

Cerebellar Nuclei ◽

Spinocerebellar Ataxias ◽

Cell Degeneration ◽

Cerebellar Purkinje Cells

Spinocerebellar ataxias (SCAs) constitute a heterogeneous group of more than 40 autosomal-dominant genetic and neurodegenerative diseases characterized by loss of balance and motor coordination due to dysfunction of the cerebellum and its efferent connections. Despite a well-described clinical and pathological phenotype, the molecular and cellular events that underlie neurodegeneration are still poorly undaerstood. Emerging research suggests that mutations in SCA genes cause disruptions in multiple cellular pathways but the characteristic SCA pathogenesis does not begin until calcium signaling pathways are disrupted in cerebellar Purkinje cells. Ca2+ signaling in Purkinje cells is important for normal cellular function as these neurons express a variety of Ca2+ channels, Ca2+-dependent kinases and phosphatases, and Ca2+-binding proteins to tightly maintain Ca2+ homeostasis and regulate physiological Ca2+-dependent processes. Abnormal Ca2+ levels can activate toxic cascades leading to characteristic death of Purkinje cells, cerebellar atrophy, and ataxia that occur in many SCAs. The output of the cerebellar cortex is conveyed to the deep cerebellar nuclei (DCN) by Purkinje cells via inhibitory signals; thus, Purkinje cell dysfunction or degeneration would partially or completely impair the cerebellar output in SCAs. In the absence of the inhibitory signal emanating from Purkinje cells, DCN will become more excitable, thereby affecting the motor areas receiving DCN input and resulting in uncoordinated movements. An outstanding advantage in studying the pathogenesis of SCAs is represented by the availability of a large number of animal models which mimic the phenotype observed in humans. By mainly focusing on mouse models displaying mutations or deletions in genes which encode for Ca2+ signaling-related proteins, in this review we will discuss the several pathogenic mechanisms related to deranged Ca2+ homeostasis that leads to significant Purkinje cell degeneration and dysfunction.

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Posterior cerebellar Purkinje cells in an SCA5/SPARCA1 mouse model are especially vulnerable to the synergistic effect of loss of β-III spectrin and GLAST

Human Molecular Genetics ◽

10.1093/hmg/ddw274 ◽

2016 ◽

pp. ddw274 ◽

Cited By ~ 8

Author(s):

Emma M. Perkins ◽

Daumante Suminaite ◽

Yvonne L. Clarkson ◽

Sin Kwan Lee ◽

Alastair R. Lyndon ◽

...

Keyword(s):

Mouse Model ◽

Synergistic Effect ◽

Purkinje Cells ◽

Cerebellar Purkinje Cells

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Antibodies to cerebellar Purkinje cells in patients with paraneoplastic cerebellar degeneration and ovarian carcinoma

Annals of Neurology ◽

10.1002/ana.410140603 ◽

1983 ◽

Vol 14 (6) ◽

pp. 609-613 ◽

Cited By ~ 195

Author(s):

John E. Greenlee ◽

H. Robert Brashear

Keyword(s):

Ovarian Carcinoma ◽

Purkinje Cells ◽

Cerebellar Degeneration ◽

Paraneoplastic Cerebellar Degeneration ◽

Cerebellar Purkinje Cells

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Generation and validation of versatile inducible CRISPRi embryonic stem cell and mouse model

PLoS Biology ◽

10.1371/journal.pbio.3000749 ◽

2020 ◽

Vol 18 (11) ◽

pp. e3000749

Author(s):

Rui Li ◽

Xianyou Xia ◽

Xing Wang ◽

Xiaoyu Sun ◽

Zhongye Dai ◽

...

Keyword(s):

Gene Expression ◽

Mouse Model ◽

Ex Vivo ◽

Embryonic Stem ◽

Regulatory Elements ◽

Loss Of Function ◽

Transgenic Expression ◽

Guide Rnas ◽

High Throughput Screens

Clustered regularly interspaced short palindromic repeat (CRISPR)-CRISPR-associated (Cas) 9 has been widely used far beyond genome editing. Fusions of deactivated Cas9 (dCas9) to transcription effectors enable interrogation of the epigenome and controlling of gene expression. However, the large transgene size of dCas9-fusion hinders its applications especially in somatic tissues. Here, we develop a robust CRISPR interference (CRISPRi) system by transgenic expression of doxycycline (Dox) inducible dCas9-KRAB in mouse embryonic stem cells (iKRAB ESC). After introduction of specific single-guide RNAs (sgRNAs), the induced dCas9-KRAB efficiently maintains gene inactivation, although it modestly down-regulates the expression of active genes. The proper timing of Dox addition during cell differentiation or reprogramming allows us to study or screen spatiotemporally activated promoters or enhancers and thereby the gene functions. Furthermore, taking the ESC for blastocyst injection, we generate an iKRAB knock-in (KI) mouse model that enables the shutdown of gene expression and loss-of-function (LOF) studies ex vivo and in vivo by a simple transduction of gRNAs. Thus, our inducible CRISPRi ESC line and KI mouse provide versatile and convenient platforms for functional interrogation and high-throughput screens of specific genes and potential regulatory elements in the setting of development or diseases.

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