Universität zu Köln

Janzen, Eva, Mendoza-Ferreira, Natalia, Hosseinibarkooie, Seyyedmohsen, Schneider, Svenja, Hupperich, Kristina, Tschanz, Theresa, Grysko, Vanessa, Riessland, Markus ORCID: 0000-0003-2592-5045, Hammerschmidt, Matthias, Rigo, Frank, Bennett, C. Frank, Kye, Min Jeong ORCID: 0000-0002-1323-7256, Torres-Benito, Laura and Wirth, Brunhilde ORCID: 0000-0003-4051-5191 (2018). CHP1 reduction ameliorates spinal muscular atrophy pathology by restoring calcineurin activity and endocytosis. Brain, 141. S. 2343 - 2362. OXFORD: OXFORD UNIV PRESS. ISSN 1460-2156

Full text not available from this repository.

Abstract

Autosomal recessive spinal muscular atrophy (SMA), the leading genetic cause of infant lethality, is caused by homozygous loss of the survival motor neuron 1 (SMN1) gene. SMA disease severity inversely correlates with the number of SMN2 copies, which in contrast to SMN1, mainly produce aberrantly spliced transcripts. Recently, the first SMA therapy based on antisense oligonucleotides correcting SMN2 splicing, namely SPINRAZA (TM), has been approved. Nevertheless, in type I SMA-affected individuals-representing 60% of SMA patients-the elevated SMN level may still be insufficient to restore motor neuron function lifelong. Plastin 3 (PLS3) and neurocalcin delta (NCALD) are two SMN-independent protective modifiers identified in humans and proved to be effective across various SMA animal models. Both PLS3 overexpression and NCALD downregulation protect against SMA by restoring impaired endocytosis; however, the exact mechanism of this protection is largely unknown. Here, we identified calcineurin-like EF-hand protein 1 (CHP1) as a novel PLS3 interacting protein using a yeast-two-hybrid screen. Co-immunoprecipitation and pull-down assays confirmed a direct interaction between CHP1 and PLS3. Although CHP1 is ubiquitously present, it is particularly abundant in the central nervous system and at SMA-relevant sites including motor neuron growth cones and neuromuscular junctions. Strikingly, we found elevated CHP1 levels in SMA mice. Congruently, CHP1 downregulation restored impaired axonal growth in Smn-depleted NSC34 motor neuron-like cells, SMA zebrafish and primary murine SMA motor neurons. Most importantly, subcutaneous injection of low-dose SMN antisense oligonucleotide in pre-symptomatic mice doubled the survival rate of severely-affected SMA mice, while additional CHP1 reduction by genetic modification prolonged survival further by 1.6-fold. Moreover, CHP1 reduction further ameliorated SMA disease hallmarks including electrophysiological defects, smaller neuromuscular junction size, impaired maturity of neuromuscular junctions and smaller muscle fibre size compared to low-dose SMN antisense oligonucleotide alone. In NSC34 cells, Chp1 knockdown tripled macropinocytosis whereas clathrin-mediated endocytosis remained unaffected. Importantly, Chp1 knockdown restored macropinocytosis in Smn-depleted cells by elevating calcineurin phosphatase activity. CHP1 is an inhibitor of calcineurin, which collectively dephosphorylates proteins involved in endocytosis, and is therefore crucial in synaptic vesicle endocytosis. Indeed, we found marked hyperphosphorylation of dynamin 1 in SMA motor neurons, which was restored to control level by the heterozygous Chp1 mutant allele. Taken together, we show that CHP1 is a novel SMA modifier that directly interacts with PLS3, and that CHP1 reduction ameliorates SMA pathology by counteracting impaired endocytosis. Most importantly, we demonstrate that CHP1 reduction is a promising SMN-independent therapeutic target for a combinatorial SMA therapy.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Janzen, Eva UNSPECIFIED UNSPECIFIED UNSPECIFIED Mendoza-Ferreira, Natalia UNSPECIFIED UNSPECIFIED UNSPECIFIED Hosseinibarkooie, Seyyedmohsen UNSPECIFIED UNSPECIFIED UNSPECIFIED Schneider, Svenja UNSPECIFIED UNSPECIFIED UNSPECIFIED Hupperich, Kristina UNSPECIFIED UNSPECIFIED UNSPECIFIED Tschanz, Theresa UNSPECIFIED UNSPECIFIED UNSPECIFIED Grysko, Vanessa UNSPECIFIED UNSPECIFIED UNSPECIFIED Riessland, Markus UNSPECIFIED orcid.org/0000-0003-2592-5045 UNSPECIFIED Hammerschmidt, Matthias UNSPECIFIED UNSPECIFIED UNSPECIFIED Rigo, Frank UNSPECIFIED UNSPECIFIED UNSPECIFIED Bennett, C. Frank UNSPECIFIED UNSPECIFIED UNSPECIFIED Kye, Min Jeong UNSPECIFIED orcid.org/0000-0002-1323-7256 UNSPECIFIED Torres-Benito, Laura UNSPECIFIED UNSPECIFIED UNSPECIFIED Wirth, Brunhilde UNSPECIFIED orcid.org/0000-0003-4051-5191 UNSPECIFIED
URN:	urn:nbn:de:hbz:38-178414
DOI:	10.1093/brain/awy167
Journal or Publication Title:	Brain
Volume:	141
Page Range:	S. 2343 - 2362
Date:	2018
Publisher:	OXFORD UNIV PRESS
Place of Publication:	OXFORD
ISSN:	1460-2156
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language SYNAPTIC VESICLE ENDOCYTOSIS; DEPENDENT BULK ENDOCYTOSIS; DISEASE GENE-PRODUCT; MOTOR-NEURON SMN; MOUSE MODEL; NEUROMUSCULAR-JUNCTIONS; CA2+-BINDING PROTEIN; IMPAIRED ENDOCYTOSIS; HOMOLOGOUS PROTEIN; ALZHEIMERS-DISEASE Multiple languages Clinical Neurology; Neurosciences Multiple languages
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/17841