Drosophila used in a study related to spastic quadriplegic cerebral palsy

 Clin Genet. 2022 Aug 31. doi: 10.1111/cge.14220. Online ahead of print.

Hereditary spastic paraparesis (HSP) presenting as cerebral palsy due to ADD3 variant with mechanistic insight provided by a Drosophila γ-adducin model.

Sanchez Marco SB Buhl E, Firth R, Zhu B, Gainsborough M, Beleza-Meireles A, Moore S, Caswell R, Stals K, Ellard S, Kennedy C, Hodge JJL, Majumdar A
 

From the abstract:

INTRODUCTION: Cerebral palsy (CP) causes neurological disability in early childhood. Hypoxic-ischaemic injury plays a major role in its aetiology, nevertheless, genetic and epigenetic factors may contribute to the clinical presentation. Mutations in ADD3 (encoding γ-adducin) gene have been described in a monogenic form of spastic quadriplegic cerebral palsy (OMIM 601568).
 

METHODS: We studied a sixteen-year-old male with spastic diplegia. ... clinical genetics assessment and Whole Exome Sequencing (WES) gave the diagnosis. We generated an animal model using Drosophila to study the effects of γ-adducin loss and gain of function.

RESULTS: ... Pan-neuronal over-expression or knock-down of the Drosophila ortholog of ADD3 called hts caused a reduction of life span and impaired locomotion thereby phenocopying aspects of the human disease.

CONCLUSION: Our animal experiments present a starting point to understand the biological processes underpinning the clinical phenotype and pathogenic mechanisms, to gain insights into potential future methods for treating or preventing ADD3 related spastic quadriplegic cerebral palsy.

PMID: 36046955

Drosophila assays of movement and mitochondria included in study of an autosomal dominant spastic paraplegia and dystonia

Mov Disord. 2021 Oct 11. doi: 10.1002/mds.28821

A Novel Variant of ATP5MC3 Associated with Both Dystonia and Spastic Paraplegia

Neilson DE, Zech M, Hufnagel RB, Slone J, Wang X, Homan S, Gutzwiller LM, Leslie EJ, Leslie ND, Xiao J, Hedera P, LeDoux MS, Gebelein B, Wilbert F, Eckenweiler M, Winkelmann J, Gilbert DL, Huang T

Abstract:

BACKGROUND: In a large pedigree with an unusual phenotype of spastic paraplegia or dystonia and autosomal dominant inheritance, linkage analysis previously mapped the disease to chromosome 2q24-2q31.

OBJECTIVE: The aim of this study is to identify the genetic cause and molecular basis of an unusual autosomal dominant spastic paraplegia and dystonia.

METHODS: Whole exome sequencing following linkage analysis was used to identify the genetic cause in a large family. Cosegregation analysis was also performed. An additional 384 individuals with spastic paraplegia or dystonia were screened for pathogenic sequence variants in the adenosine triphosphate (ATP) synthase membrane subunit C locus 3 gene (ATP5MC3). The identified variant was submitted to the "GeneMatcher" program for recruitment of additional subjects. Mitochondrial functions were analyzed in patient-derived fibroblast cell lines. Transgenic Drosophila carrying mutants were studied for movement behavior and mitochondrial function.

RESULTS: Exome analysis revealed a variant (c.318C > G; p.Asn106Lys) (NM_001689.4) in ATP5MC3 in a large family with autosomal dominant spastic paraplegia and dystonia that cosegregated with affected individuals. No variants were identified in an additional 384 individuals with spastic paraplegia or dystonia. GeneMatcher identified an individual with the same genetic change, acquired de novo, who manifested upper-limb dystonia. Patient fibroblast studies showed impaired complex V activity, ATP generation, and oxygen consumption. Drosophila carrying orthologous mutations also exhibited impaired mitochondrial function and displayed reduced mobility.

CONCLUSION: A unique form of familial spastic paraplegia and dystonia is associated with a heterozygous ATP5MC3 variant that also reduces mitochondrial complex V activity.

DOI: 10.1002/mds.28821
PMID: 34636445

Drosophila model reveals mechanistic insights into the human disease-associated gene PNPLA6 and disease-associated variants

Sunderhaus ER, Law AD, Kretzschmar D. Disease-Associated PNPLA6 Mutations Maintain Partial Functions When Analyzed in Drosophila. Front Neurosci. 2019 Nov 6;13:1207. PMID:
31780887; PMCID: PMC6852622.

From the abstract: "Mutations in patatin-like phospholipase domain-containing protein 6 (PNPLA6) have been linked with a number of inherited diseases with clinical symptoms that include spastic paraplegia, ataxia, and chorioretinal dystrophy. PNPLA6 is an evolutionary conserved protein whose ortholog in Drosophila is Swiss-Cheese (SWS). ... disease-causing point mutations are found in homozygous patients, with some localized in the phospholipase domain while others are in a region that contains several cNMP binding sites. To investigate how different mutations affect the function of PNPLA6 in an in vivo model, we expressed them in the Drosophila sws1 null mutant. Expressing wild-type PNPLA6 suppressed the locomotion and degenerative phenotypes in sws 1 and restored lipid levels, confirming that the human protein can replace fly SWS. In contrast, none of the mutant proteins restored lipid levels, although they suppressed the behavioral and degenerative phenotypes, at least in early stages. These results show that these mutant forms of PNPLA6 retain some biological function, indicating that disruption of lipid homeostasis is only part of the pathogenic mechanism. ..."

Review in the journal Traffic on neuronal growth factor signaling -- relevance to ALS and hereditary spastic paraplegia

Deshpande M, Rodal AA. The Crossroads of Synaptic Growth Signaling, Membrane Traffic and Neurological Disease: Insights from Drosophila. Traffic. 2016 Feb;17(2):87-101. PMID: 26538429.

From the abstract: "... Neuronal growth factor signaling is highly dependent on membrane traffic... Here, we review recent findings from the Drosophila larval neuromuscular junction (NMJ) that illustrate how specific steps of intracellular traffic and inter-organelle interactions impinge on signaling ... These membrane trafficking and signaling pathways have been implicated in human motor neuron diseases including amyotrophic lateral sclerosis and hereditary spastic paraplegia, highlighting their importance for neuronal health and survival."

Confidence in numbers: work in 3 model organisms supports gene-disease link in humans

Gan-Or Z, Bouslam N, Birouk N, Lissouba A, Chambers DB, Vérièpe J, Androschuck A, Laurent SB, Rochefort D, Spiegelman D, Dionne-Laporte A, Szuto A, Liao M, Figlewicz DA, Bouhouche A, Benomar A, Yahyaoui M, Ouazzani R, Yoon G, Dupré N, Suchowersky O, Bolduc FV, Parker JA, Dion PA, Drapeau P, Rouleau GA, Bencheikh BO. Mutations in CAPN1 Cause Autosomal-Recessive Hereditary Spastic Paraplegia. Am J Hum Genet. 2016 May 5;98(5):1038-46. PMID: 27153400.

From the abstract: "Hereditary spastic paraplegia (HSP) is a genetically and clinically heterogeneous disease characterized by spasticity and weakness of the lower limbs with or without additional neurological symptoms. Although more than 70 genes and genetic loci have been implicated in HSP, many families remain genetically undiagnosed, suggesting that other genetic causes of HSP are still to be identified. HSP can be inherited in an autosomal-dominant, autosomal-recessive, or X-linked manner. In the current study, we performed whole-exome sequencing to analyze a total of nine affected individuals in three families with autosomal-recessive HSP. Rare homozygous and compound-heterozygous nonsense, missense, frameshift, and splice-site mutations in CAPN1 were identified ... CAPN1 encodes calpain 1, a protease that is widely present in the CNS. ... Three models of calpain 1 deficiency were further studied. In Caenorhabditis elegans, loss of calpain 1 function resulted in neuronal and axonal dysfunction and degeneration. Similarly, loss-of-function of the Drosophila melanogaster ortholog calpain B caused locomotor defects and axonal anomalies. Knockdown of calpain 1a, a CAPN1 ortholog in Danio rerio, resulted in abnormal branchiomotor neuron migration and disorganized acetylated-tubulin axonal networks in the brain. The identification of mutations in CAPN1 in HSP expands our understanding of the disease causes and potential mechanisms."

Cold temperature & fly models of Hereditary Spastic Paraplegia

Baxter SL, Allard DE, Crowl C, Sherwood NT. Cold temperature improves mobility and survival in drosophila models of Autosomal-Dominant Hereditary Spastic Paraplegia (AD-HSP). Dis Model Mech. 2014 Jun 6. pii: dmm.013987. PMID: 24906373.

Rat cell and fly models related to hereditary spastic paraplegia

Solowska JM, D'Rozario M, Jean DC, Davidson MW, Marenda DR, Baas PW. Pathogenic Mutation of Spastin Has Gain-of-Function Effects on Microtubule Dynamics. J Neurosci. 2014 Jan 29;34(5):1856-67. PMID: 24478365.

Fly study related to hereditary spastic paraplegia (HSP)

O'Sullivan NC, Dräger N, O'Kane CJ. Characterization of the Drosophila atlastin interactome reveals VCP as a functionally related interactor. J Genet Genomics. 2013 Jun 20;40(6):297-306. PMID: 23790629.

Troyer syndrome. New fly model. Recent report.

Troyer syndrome is one of several hereditary spastic paraplegias.

Nahm M, Lee MJ, Parkinson W, Lee M, Kim H, Kim YJ, Kim S, Cho YS, Min BM, Bae YC, Broadie K, Lee S. Spartin Regulates Synaptic Growth and Neuronal Survival by
Inhibiting BMP-Mediated Microtubule Stabilization. Neuron. 2013 Feb 20;77(4):680-95. doi: 10.1016/j.neuron.2012.12.015. PubMed PMID: 23439121.

New fly model of hereditary spastic paraplegia. Recent report.

These authors describe a new fly model of HSP. View other posts on HSP here.

Füger P, Sreekumar V, Schüle R, Kern JV, Stanchev DT, Schneider CD, Karle KN, Daub KJ, Siegert VK, Flötenmeyer M, Schwarz H, Schöls L, Rasse TM. Spastic Paraplegia Mutation N256S in the Neuronal Microtubule Motor KIF5A Disrupts Axonal Transport in a Drosophila HSP Model. PLoS Genet. 2012 Nov;8(11):e1003066. doi:10.1371/journal.pgen.1003066. PubMed PMID: 23209432.

Complex Hereditary Spastic Paraplegia. Supporting evidence in fly. Recent report.

These authors state in the abstract that "An essential role for DDHD2 in the human CNS, and perhaps more specifically in synaptic functioning, is supported by a reduced number of active zones at synaptic terminals in Ddhd-knockdown Drosophila models."

Schuurs-Hoeijmakers JH, Geraghty MT, Kamsteeg EJ, Ben-Salem S, de Bot ST,
Nijhof B, van de Vondervoort II, van der Graaf M, Nobau AC, Otte-Höller I,
Vermeer S, Smith AC, Humphreys P, Schwartzentruber J; FORGE Canada Consortium,
Ali BR, Al-Yahyaee SA, Tariq S, Pramathan T, Bayoumi R, Kremer HP, van de
Warrenburg BP, van den Akker WM, Gilissen C, Veltman JA, Janssen IM, Vulto-van
Silfhout AT, van der Velde-Visser S, Lefeber DJ, Diekstra A, Erasmus CE,
Willemsen MA, Vissers LE, Lammens M, van Bokhoven H, Brunner HG, Wevers RA,
Schenck A, Al-Gazali L, de Vries BB, de Brouwer AP. Mutations in DDHD2, Encoding
an Intracellular Phospholipase A(1), Cause a Recessive Form of Complex Hereditary
Spastic Paraplegia. Am J Hum Genet. 2012 Nov 20. doi:pii: S0002-9297(12)00576-9.
10.1016/j.ajhg.2012.10.017. PubMed PMID: 23176823.

You can view associated human diseases and read about hereditary spastic paraplegias at NCBI's Gene Reviews.