{"title":"Pigmentation-based insertional mutagenesis is a simple and potent screening approach for identifying neurocristopathy-associated genes in mice.","authors":"Nicolas Pilon","doi":"10.1080/21675511.2016.1156287","DOIUrl":"https://doi.org/10.1080/21675511.2016.1156287","url":null,"abstract":"<p><p>Neurocristopathies form a specific group of rare genetic diseases in which a defect in neural crest cell development is causal. Because of the large number of neural crest cell derivatives, distinct structures/cell types (isolated or in combination) are affected in each neurocristopathy. The most important issues in this research field is that the underlying genetic cause and associated pathogenic mechanism of most cases of neurocristopathy are poorly understood. This article describes how a relatively simple insertional mutagenesis approach in the mouse has proved useful for identifying new candidate genes and pathogenic mechanisms for diverse neurocristopathies. </p>","PeriodicalId":74639,"journal":{"name":"Rare diseases (Austin, Tex.)","volume":"4 1","pages":"e1156287"},"PeriodicalIF":0.0,"publicationDate":"2016-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/21675511.2016.1156287","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"34355399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The conditional KO approach: Cre/Lox technology in human neurons.","authors":"Christopher Patzke, Thomas C Südhof","doi":"10.1080/21675511.2015.1131884","DOIUrl":"https://doi.org/10.1080/21675511.2015.1131884","url":null,"abstract":"ABSTRACT The use of human pluripotent stem cells to model human diseases has become a new standard in biomedical sciences. To this end, patient-derived somatic cells are studied in vitro to mimic human pathological conditions. Here, we describe an alternative experimental strategy, the ‘conditional KO approach’, which allows engineering disease-relevant mutations in pluripotent stem cells from healthy donors. In combination with the Cre/Lox technology, this strategy enables us to study the molecular causes of human diseases independent of the genetic background or of genetic alterations induced by clonal selection. As a proof-of-principle, we generated pluripotent stem cells with conditional loss-of-function mutations in the human STXBP1 gene that encodes Munc18-1. Using neurons derived from these cells, we show that heterozygous disruption of STXBP1 produces a specific and selective impairment in synaptic transmission that may account for the severe neurological disease caused by such mutations in human patients.","PeriodicalId":74639,"journal":{"name":"Rare diseases (Austin, Tex.)","volume":"4 1","pages":"e1131884"},"PeriodicalIF":0.0,"publicationDate":"2016-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/21675511.2015.1131884","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"34451708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Dystrophin: The dead calm of a dogma.","authors":"Dariusz C Górecki","doi":"10.1080/21675511.2016.1153777","DOIUrl":"10.1080/21675511.2016.1153777","url":null,"abstract":"<p><p>Duchenne muscular dystrophy (DMD) is the most common inherited muscle disease leading to severe disability and death of young men. Current interventions are palliative as no treatment improves the long-term outcome. Therefore, new therapeutic modalities with translational potential are urgently needed and abnormalities downstream from the absence of dystrophin are realistic targets. It has been shown that DMD mutations alter extracellular ATP (eATP) signaling via P2RX7 purinoceptor upregulation, which leads to autophagic death of dystrophic muscle cells. Furthermore, the eATP-P2RX7 axis contributes to DMD pathology by stimulating harmful inflammatory responses. We demonstrated recently that genetic ablation or pharmacological inhibition of P2RX7 in the mdx mouse model of DMD produced functional attenuation of both muscle and non-muscle symptoms, establishing this receptor as an attractive therapeutic target. Central to the argument presented here, this purinergic phenotype affects dystrophic myoblasts. Muscle cells were believed not to be affected at this stage of differentiation, as they do not produce detectable dystrophin protein. Our findings contradict the central hypothesis stating that aberrant dystrophin expression is inconsequential in myoblasts and the DMD pathology results from effects such as sarcolemma fragility, due to the absence of dystrophin, in differentiated myofibres. However, we discuss here the evidence that, already in myogenic cells, DMD mutations produce a plethora of abnormalities, including in cell proliferation, differentiation, energy metabolism, Ca(2+) homeostasis and death, leading to impaired muscle regeneration. We hope that this discussion may bring to light further results that will help re-evaluating the established belief. Clearly, understanding how DMD mutations alter such a range of functions in myogenic cells is vital for developing effective therapies. </p>","PeriodicalId":74639,"journal":{"name":"Rare diseases (Austin, Tex.)","volume":"4 1","pages":"e1153777"},"PeriodicalIF":0.0,"publicationDate":"2016-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/8f/c6/krad-04-01-1153777.PMC4838315.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"34451713","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Problems and solutions for the analysis of somatic CAG repeat expansion and their relationship to Huntington's disease toxicity.","authors":"Helen Budworth, Cynthia T McMurray","doi":"10.1080/21675511.2015.1131885","DOIUrl":"https://doi.org/10.1080/21675511.2015.1131885","url":null,"abstract":"<p><p>Huntington's Disease is caused by inheritance of a single disease-length allele harboring an expanded CAG repeat, which continues to expand in somatic tissues with age. Whether somatic expansion contributed to toxicity was unknown. From extensive work from multiple laboratories, it has been made clear that toxicity depended on length of the inherited allele, but whether preventing or delaying somatic repeat expansion in vivo would be beneficial was unknown, since the inherited disease allele was still expressed. In Budworth et al., we provided definitive evidence that suppressing the somatic expansion in mice substantially delays disease onset in littermates that inherit the same disease-length allele. This key discovery opens the door for therapeutic approaches targeted at stopping or shortening the CAG tract during life. The analysis was difficult and, at times, non-standard. Here, we take the opportunity to discuss the challenges, the analytical solutions, and to address some controversial issues with respect to expansion biology. </p>","PeriodicalId":74639,"journal":{"name":"Rare diseases (Austin, Tex.)","volume":"4 1","pages":"e1131885"},"PeriodicalIF":0.0,"publicationDate":"2016-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/21675511.2015.1131885","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"34451711","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Mitochondrial dysfunction and defects in lipid homeostasis as therapeutic targets in neurodegeneration with brain iron accumulation.","authors":"Kerri J Kinghorn, Jorge Iván Castillo-Quan","doi":"10.1080/21675511.2015.1128616","DOIUrl":"https://doi.org/10.1080/21675511.2015.1128616","url":null,"abstract":"<p><p>The PLA2G6 gene encodes a group VIA calcium independent phospholipase A2 (iPLA2β), which hydrolyses glycerophospholipids to release fatty acids and lysophospholipids. Mutations in PLA2G6 are associated with a number of neurodegenerative disorders including neurodegeneration with brain iron accumulation (NBIA), infantile neuroaxonal dystrophy (INAD), and dystonia parkinsonism, collectively known as PLA2G6-associated neurodegeneration (PLAN). Recently Kinghorn et al. demonstrated in Drosophila and PLA2G6 mutant fibroblasts that loss of normal PLA2G6 activity is associated with mitochondrial dysfunction and mitochondrial lipid peroxidation. Furthermore, they were able to show the beneficial effects of deuterated polyunsaturated fatty acids (D-PUFAs), which reduce lipid peroxidation. D-PUFAs were able to rescue the locomotor deficits of flies lacking the fly ortholog of PLA2G6 (iPLA2-VIA), as well as the mitochondrial abnormalities in PLA2G6 mutant fibroblasts. This work demonstrated that the iPLA2-VIA knockout fly is a useful organism to dissect the mechanisms of pathogenesis of PLAN, and that further investigation is required to determine the therapeutic potential of D-PUFAs in patients with PLA2G6 mutations. The fruit fly has also been used to study some of the other genetic causes of NBIA, and here we also describe what is known about the mechanisms of pathogenesis of these NBIA variants. Mitochondrial dysfunction, defects in lipid metabolism, as well as defective Coenzyme A (CoA) biosynthesis, have all been implicated in some genetic forms of NBIA, including PANK2, CoASY, C12orf19 and FA2H. </p>","PeriodicalId":74639,"journal":{"name":"Rare diseases (Austin, Tex.)","volume":"4 1","pages":"e1128616"},"PeriodicalIF":0.0,"publicationDate":"2016-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/21675511.2015.1128616","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"34451707","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Saverio Marchi, Eliana Trapani, Mariangela Corricelli, Luca Goitre, Paolo Pinton, Saverio Francesco Retta
{"title":"Beyond multiple mechanisms and a unique drug: Defective autophagy as pivotal player in cerebral cavernous malformation pathogenesis and implications for targeted therapies.","authors":"Saverio Marchi, Eliana Trapani, Mariangela Corricelli, Luca Goitre, Paolo Pinton, Saverio Francesco Retta","doi":"10.1080/21675511.2016.1142640","DOIUrl":"https://doi.org/10.1080/21675511.2016.1142640","url":null,"abstract":"<p><p>Cerebral Cavernous Malformation (CCM) is a major cerebrovascular disease of proven genetic origin affecting 0.3-0.5% of the general population. It is characterized by abnormally enlarged and leaky capillaries, which predispose to seizures, focal neurological deficits and intracerebral hemorrhage. Causative loss-of-function mutations have been identified in 3 genes, KRIT1 (CCM1), CCM2 and PDCD10 (CCM3). While providing new options for the development of pharmacological therapies, recent advances in knowledge of the functions of these genes have clearly indicated that they exert pleiotropic effects on several biological pathways. Recently, we found that defective autophagy is a common feature of loss-of-function mutations of the 3 known CCM genes, and underlies major phenotypic signatures of CCM disease, including endothelial-to-mesenchymal transition and enhanced ROS production, suggesting a unifying pathogenetic mechanism and reconciling the distinct therapeutic approaches proposed so far. In this invited review, we discuss autophagy as a possible unifying mechanism in CCM disease pathogenesis, and new perspectives and avenues of research for disease prevention and treatment, including novel potential drug repurposing and combination strategies, and identification of genetic risk factors as basis for development of personalized medicine approaches. </p>","PeriodicalId":74639,"journal":{"name":"Rare diseases (Austin, Tex.)","volume":"4 1","pages":"e1142640"},"PeriodicalIF":0.0,"publicationDate":"2016-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/21675511.2016.1142640","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"34451712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Listen to your gut: Using adhesion to shape the surface of functionally diverse epithelia","authors":"M. Tyska","doi":"10.1080/21675511.2016.1220469","DOIUrl":"https://doi.org/10.1080/21675511.2016.1220469","url":null,"abstract":"ABSTRACT Cell surface protrusions play central roles in the physiological function of a number of organ systems. Recent discoveries suggest that polarized cells in functionally diverse epithelia employ conserved cadherin-based adhesion complexes to shape, stabilize, and organize actin-based protrusions during differentiation. Below we discuss the implications of these findings for understanding human biology and disease, and highlight promising directions for future studies on this conserved mechanism for shaping the cell surface.","PeriodicalId":74639,"journal":{"name":"Rare diseases (Austin, Tex.)","volume":"4 1","pages":"200"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/21675511.2016.1220469","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60422851","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Emma Bondy-Chorney, Tara E. Crawford Parks, A. Ravel-Chapuis, B. Jasmin, J. Côté
{"title":"Staufen1s role as a splicing factor and a disease modifier in Myotonic Dystrophy Type I","authors":"Emma Bondy-Chorney, Tara E. Crawford Parks, A. Ravel-Chapuis, B. Jasmin, J. Côté","doi":"10.1080/21675511.2016.1225644","DOIUrl":"https://doi.org/10.1080/21675511.2016.1225644","url":null,"abstract":"ABSTRACT In a recent issue of PLOS Genetics, we reported that the double-stranded RNA-binding protein, Staufen1, functions as a disease modifier in the neuromuscular disorder Myotonic Dystrophy Type I (DM1). In this work, we demonstrated that Staufen1 regulates the alternative splicing of exon 11 of the human Insulin Receptor, a highly studied missplicing event in DM1, through Alu elements located in an intronic region. Furthermore, we found that Staufen1 overexpression regulates numerous alternative splicing events, potentially resulting in both positive and negative effects in DM1. Here, we discuss our major findings and speculate on the details of the mechanisms by which Staufen1 could regulate alternative splicing, in both normal and DM1 conditions. Finally, we highlight the importance of disease modifiers, such as Staufen1, in the DM1 pathology in order to understand the complex disease phenotype and for future development of new therapeutic strategies.","PeriodicalId":74639,"journal":{"name":"Rare diseases (Austin, Tex.)","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/21675511.2016.1225644","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60423219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Canine models of human rare disorders","authors":"M. Hytönen, H. Lohi","doi":"10.1080/21675511.2016.1241362","DOIUrl":"https://doi.org/10.1080/21675511.2016.1241362","url":null,"abstract":"ABSTRACT Millions of children worldwide are born with rare and debilitating developmental disorders each year. Although an increasing number of these conditions are being recognized at the molecular level, the characterization of the underlying pathophysiology remains a grand challenge. This is often due to the lack of appropriate patient material or relevant animal models. Dogs are coming to the rescue as physiologically relevant large animal models. Hundreds of spontaneous genetic conditions have been described in dogs, most with close counterparts to human rare disorders. Our recent examples include the canine models of human Caffey (SLC37A2), van den Ende-Gupta (SCARF2) and Raine (FAM20C) syndromes. These studies demonstrate the pathophysiological similarity of human and canine syndromes, and suggest that joint efforts to characterize both human and canine rare diseases could provide additional benefits to the advancement of the field of rare diseases. Besides revealing new candidate genes, canine models allow access to experimental resources such as cells, tissues and even live animals for research and intervention purposes.","PeriodicalId":74639,"journal":{"name":"Rare diseases (Austin, Tex.)","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/21675511.2016.1241362","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60423549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Molecular mechanisms underlying Spinocerebellar Ataxia 17 (SCA17) pathogenesis","authors":"Su Yang, Xiao-Jiang Li, Shihua Li","doi":"10.1080/21675511.2016.1223580","DOIUrl":"https://doi.org/10.1080/21675511.2016.1223580","url":null,"abstract":"ABSTRACT Spinocerebellar ataxia 17 (SCA17) belongs to the family of 9 genetically inherited, late-onset neurodegenerative diseases, which are caused by polyglutamine (polyQ) expansion in different proteins. In SCA17, the polyQ expansion occurs in the TATA box binding protein (TBP), which functions as a general transcription factor. Patients with SCA17 suffer from a broad array of motor and non-motor defects, and their life expectancy is normally within 20 y after the initial appearance of symptoms. Currently there is no effective treatment, but remarkable efforts have been devoted to tackle this devastating disorder. In this review, we will summarize our current knowledge about the molecular mechanisms underlying the pathogenesis of SCA17, with a primary focus on transcriptional dysregulations. We believe that impaired transcriptional activities caused by mutant TBP with polyQ expansion is a major form of toxicity contributing to SCA17 pathogenesis, and rectifying the altered level of downstream transcripts represents a promising therapeutic approach for the treatment of SCA17.","PeriodicalId":74639,"journal":{"name":"Rare diseases (Austin, Tex.)","volume":"4 1","pages":"349 - 365"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/21675511.2016.1223580","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60422747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}