| 1. |
- Freischmidt, Axel, et al.
(author)
-
A serum microRNA sequence reveals fragile X protein pathology in amyotrophic lateral sclerosis
- 2021
-
In: Brain. - : Oxford University Press. - 0006-8950 .- 1460-2156. ; 144:4, s. 1214-1229
-
Journal article (peer-reviewed)abstract
- Knowledge about converging disease mechanisms in the heterogeneous syndrome amyotrophic lateral sclerosis (ALS) is rare, but may lead to therapies effective in most ALS cases. Previously, we identified serum microRNAs downregulated in familial ALS, the majority of sporadic ALS patients, but also in presymptomatic mutation carriers. A 5-nucleotide sequence motif (GDCGG; D = G, A or U) was strongly enriched in these ALS-related microRNAs. We hypothesized that deregulation of protein(s) binding predominantly to this consensus motif was responsible for the ALS-linked microRNA fingerprint. Using microRNA pull-down assays combined with mass spectrometry followed by extensive biochemical validation, all members of the fragile X protein family, FMR1, FXR1 and FXR2, were identified to directly and predominantly interact with GDCGG microRNAs through their structurally disordered RGG/RG domains. Preferential association of this protein family with ALS-related microRNAs was confirmed by in vitro binding studies on a transcriptome-wide scale. Immunohistochemistry of lumbar spinal cord revealed aberrant expression level and aggregation of FXR1 and FXR2 in C9orf72- and FUS-linked familial ALS, but also patients with sporadic ALS. Further analysis of ALS autopsies and induced pluripotent stem cell-derived motor neurons with FUS mutations showed co-aggregation of FXR1 with FUS. Hence, our translational approach was able to take advantage of blood microRNAs to reveal CNS pathology, and suggests an involvement of the fragile X-related proteins in familial and sporadic ALS already at a presymptomatic stage. The findings may uncover disease mechanisms relevant to many patients with ALS. They furthermore underscore the systemic, extra-CNS aspect of ALS.
|
|
| 2. |
- Helferich, Anika M., et al.
(author)
-
Dysregulation of a novel miR-1825/TBCB/TUBA4A pathway in sporadic and familial ALS
- 2018
-
In: Cellular and Molecular Life Sciences (CMLS). - : Springer. - 1420-682X .- 1420-9071. ; 75:23, s. 4301-4319
-
Journal article (peer-reviewed)abstract
- Genetic and functional studies suggest diverse pathways being affected in the neurodegenerative disease amyotrophic lateral sclerosis (ALS), while knowledge about converging disease mechanisms is rare. We detected a downregulation of microRNA-1825 in CNS and extra-CNS system organs of both sporadic (sALS) and familial ALS (fALS) patients. Combined transcriptomic and proteomic analysis revealed that reduced levels of microRNA-1825 caused a translational upregulation of tubulin-folding cofactor b (TBCB). Moreover, we found that excess TBCB led to depolymerization and degradation of tubulin alpha-4A (TUBA4A), which is encoded by a known ALS gene. Importantly, the increase in TBCB and reduction of TUBA4A protein was confirmed in brain cortex tissue of fALS and sALS patients, and led to motor axon defects in an in vivo model. Our discovery of a microRNA-1825/TBCB/TUBA4A pathway reveals a putative pathogenic cascade in both fALS and sALS extending the relevance of TUBA4A to a large proportion of ALS cases.
|
|
| 3. |
- Yilmaz, Rüstem, et al.
(author)
-
SQSTM1/p62 variants in 486 patients with familial ALS from Germany and Sweden
- 2020
-
In: Neurobiology of Aging. - : ELSEVIER SCIENCE INC. - 0197-4580 .- 1558-1497. ; 87, s. 139.e9-139.e15
-
Journal article (peer-reviewed)abstract
- Several studies reported amyotrophic lateral sclerosis (ALS)-linked mutations in TBK1, OPTN, VCP, UBQLN2, and SQSTM1 genes encoding proteins involved in autophagy. SQSTM1 was originally identified by a candidate gene approach because it encodes p62, a multifunctional protein involved in protein degradation both through proteasomal regulation and autophagy. Both p62 and optineurin (encoded by OPTN) are direct interaction partners and substrates of TBK1, and these 3 proteins form the core of a genetic and functional network that may connect autophagy with ALS. Considering the molecular and conceptual relevance of the TBK1/OPTN/SQSTM1 "triangle," we here performed a targeted screen for SQSTM1 variants in 486 patients with familial ALS from Germany and Sweden by analyzing whole-exome sequencing data. We report 9 novel and 5 previously reported rare variants in SQSTM1 and discuss the current evidence for SQSTM1 as a primary disease gene for ALS. We conclude that the evidence for causality remains vague for SQSTM1 and is weaker than for the other autophagy genes, for example, TBK1 and OPTN.
|
|
| 4. |
- Higelin, Julia, et al.
(author)
-
NEK1 loss-of-function mutation induces DNA damage accumulation in ALS patient-derived motoneurons
- 2018
-
In: Stem Cell Research. - : Elsevier. - 1873-5061 .- 1876-7753. ; 30, s. 150-162
-
Journal article (peer-reviewed)abstract
- Mutations in genes coding for proteins involved in DNA damage response (DDR) and repair, such as C9orf72 and FUS (Fused in Sarcoma), are associated with neurodegenerative diseases and lead to amyotrophic lateral sclerosis (ALS). Heterozygous loss-of-function mutations in NEK1 (NIMA-related kinase 1) have also been recently found to cause ALS. NEK1 codes for a multifunctional protein, crucially involved in mitotic checkpoint control and DDR. To resolve pathological alterations associated with NEK1 mutation, we compared hiPSC-derived motoneurons carrying a NEK1 mutation with mutant C9orf72 and wild type neurons at basal level and after DNA damage induction. Motoneurons carrying a C9orf72 mutation exhibited cell specific signs of increased DNA damage. This phenotype was even more severe in NEK1c.2434A>T neurons that showed significantly increased DNA damage at basal level and impaired DDR after induction of DNA damage in an maturation-dependent manner. Our results provide first mechanistic insight in pathophysiological alterations induced by NEK1 mutations and point to a converging pathomechanism of different gene mutations causative for ALS. Therefore, our study contributes to the development of novel therapeutic strategies to reduce DNA damage accumulation in neurodegenerative diseases and ALS.
|
|
| 5. |
- Lulé, Dorothée E., et al.
(author)
-
Deficits in verbal fluency in presymptomatic C9orf72 mutation gene carriers-a developmental disorder
- 2020
-
In: Journal of Neurology, Neurosurgery and Psychiatry. - : BMJ Publishing Group Ltd. - 0022-3050 .- 1468-330X. ; 91:11, s. 1195-1200
-
Journal article (peer-reviewed)abstract
- Background: A mutation in C9orf72 constitute a cross-link between amyotrophic lateral sclerosis (ALS) and fronto-temporal dementia (FTD). At clinical manifestation, both patient groups may present with either cognitive impairment of predominantly behaviour or language (in FTD) or motor dysfunctions (in ALS).Methods: In total, 36 non-symptomatic mutation carriers from ALS or FTD families were examined, including 21 subjects with C9orf72 and 15 with SOD1 mutations. Data were compared with 91 age-matched, education-matched and gender-matched healthy subjects (56 were first-degree relatives from ALS or FTD families, 35 with no known family history of ALS/FTD). MRI scanning for diffusion tensor imaging was performed to map fractional anisotropy (FA). Subjects performed an extensive neuropsychological assessment to address verbal fluency, language, executive, memory and visuospatial function. Measurements were repeated after 12 months.Results: C9orf72 expansion carriers performed significantly worse in verbal fluency and non-verbal memory and presented with distinct alterations in structural white matter integrity indicated by lower FA values in inferior and orbitofrontal cortical areas compared with carriers of SOD1 mutations or healthy subjects. Loss of structural integrity was associated with decreased verbal fluency performance. White matter alterations and cognitive performance showed no changes over 12 months in all subjects.Discussion: Reduced verbal fluency performance seems to be a distinct clinical feature of C9orf72 carriers before symptomatic disease onset without evidence for change over time in our cohort. The results support the emerging hypothesis of a general disorder in development in addition to neurodegeneration in C9orf72 carriers.
|
|
| 6. |
- Mueller, Kathrin, et al.
(author)
-
Comprehensive analysis of the mutation spectrum in 301 German ALS families
- 2018
-
In: Journal of Neurology, Neurosurgery and Psychiatry. - : BMJ Publishing Group Ltd. - 0022-3050 .- 1468-330X. ; 89:8, s. 817-827
-
Journal article (peer-reviewed)abstract
- Objectives Recent advances in amyotrophic lateral sclerosis (ALS) genetics have revealed that mutations in any of more than 25 genes can cause ALS, mostly as an autosomal-dominant Mendelian trait. Detailed knowledge about the genetic architecture of ALS in a specific population will be important for genetic counselling but also for genotype-specific therapeutic interventions.Methods Here we combined fragment length analysis, repeat-primed PCR, Southern blotting, Sanger sequencing and whole exome sequencing to obtain a comprehensive profile of genetic variants in ALS disease genes in 301 German pedigrees with familial ALS. We report C9orf72 mutations as well as variants in consensus splice sites and non-synonymous variants in protein-coding regions of ALS genes. We furthermore estimate their pathogenicity by taking into account type and frequency of the respective variant as well as segregation within the families.Results 49% of our German ALS families carried a likely pathogenic variant in at least one of the earlier identified ALS genes. In 45% of the ALS families, likely pathogenic variants were detected in C9orf72, SOD1, FUS, TARDBP or TBK1, whereas the relative contribution of the other ALS genes in this familial ALS cohort was 4%. We identified several previously unreported rare variants and demonstrated the absence of likely pathogenic variants in some of the recently described ALS disease genes.Conclusions We here present a comprehensive genetic characterisation of German familial ALS. The present findings are of importance for genetic counselling in clinical practice, for molecular research and for the design of diagnostic gene panels or genotype-specific therapeutic interventions in Europe.
|
|
| 7. |
- Tazelaar, Gijs H. P., et al.
(author)
-
Association of NIPA1 repeat expansions with amyotrophic lateral sclerosis in a large international cohort
- 2019
-
In: Neurobiology of Aging. - : Elsevier. - 0197-4580 .- 1558-1497. ; 74, s. 234.e9-234.e15
-
Journal article (peer-reviewed)abstract
- NIPA1 (nonimprinted in Prader-Willi/Angelman syndrome 1) mutations are known to cause hereditary spastic paraplegia type 6, a neurodegenerative disease that phenotypically overlaps to some extent with amyotrophic lateral sclerosis (ALS). Previously, a genomewide screen for copy number variants found an association with rare deletions in NIPA1 and ALS, and subsequent genetic analyses revealed that long (or expanded) polyalanine repeats in NIPA1 convey increased ALS susceptibility. We set out to perform a large-scale replication study to further investigate the role of NIPA1 polyalanine expansions with ALS, in which we characterized NIPA1 repeat size in an independent international cohort of 3955 patients with ALS and 2276 unaffected controls and combined our results with previous reports. Meta-analysis on a total of 6245 patients with ALS and 5051 controls showed an overall increased risk of ALS in those with expanded (>8) GCG repeat length (odds ratio = 1.50, p = 3.8×10−5). Together with previous reports, these findings provide evidence for an association of an expanded polyalanine repeat in NIPA1 and ALS.
|
|
| 8. |
- Andersen, Peter M., 1962-, et al.
(author)
-
Caregivers’ divergent perspectives on patients’ well-being and attitudes towards hastened death in Germany, Poland and Sweden
- 2022
-
In: Amyotrophic Lateral Sclerosis and Frontotemporal Degeneration. - : Taylor & Francis. - 2167-8421 .- 2167-9223. ; 23:3-4, s. 252-262
-
Journal article (peer-reviewed)abstract
- Background: During the course of amyotrophic lateral sclerosis (ALS), patients and their families are faced with existential decisions concerning life-prolonging and -shortening measures. Correct anticipation of patient’s well-being and preferences is a prerequisite for patient-centered surrogate decision making.Methods: In Germany (N = 84), Poland (N = 77) and Sweden (N = 73) patient-caregiver dyads were interviewed. Standardized questionnaires on well-being (ADI-12 for depressiveness; ACSA for global quality of life) and wish for hastened death (SAHD) were used in ALS patients. Additionally, caregivers were asked to fill out the same questionnaires by anticipating patients’ perspective (surrogate perspective).Results: Caregivers significantly underestimated patients’ well-being in Germany and Poland. For Swedish caregivers, there were just as many who underestimated and overestimated well-being. The same was true for wish for hastened death in all three countries. For Swedish and Polish patients, caregivers’ estimation of well-being was not even associated with patients’ responses and the same was true for estimation of wish for hastened death in all three countries. Older caregivers and those with the most frequent encounter with the patient were the closest in their rating of well-being and wish for hastened death to the patients’ actual state, while caregivers with chronic disease him/herself were more likely to underestimate patient’s well-being.Discussion: Despite distinct cultural differences, there was a clear discrepancy between patients’ and caregivers’ perspective on patients’ well-being and preferences towards life in all three countries. This possible bias in caregivers’ judgment needs to be taken into account in surrogate decision making.
|
|
| 9. |
- Andersen, Peter M., 1962-, et al.
(author)
-
Therapeutic decisions in ALS patients : cross-cultural differences and clinical implications
- 2018
-
In: Journal of Neurology. - : Springer Berlin/Heidelberg. - 0340-5354 .- 1432-1459. ; 265:7, s. 1600-1606
-
Journal article (peer-reviewed)abstract
- Objective: Quantitative analysis of decision-making on therapeutic options in different sociocultural context in amyotrophic lateral sclerosis (ALS).Methods: ALS patients (n = 244) were consecutively recruited in Germany (n = 83), Poland (n = 83), and Sweden (n = 78) in a prospective cross-cultural study (www.NEEDSinALS.com). They were interviewed on preferences for therapeutic techniques including invasive (IV) and non-invasive ventilation (NIV), as well as percutaneous endoscopic gastrostomy (PEG) and on hypothetical termination of these using quantitative questions. Using standardized questionnaires, religiousness, personal values, quality of life, and depressiveness were assessed.Results: NIV was most frequently used in Germany and PEG in Sweden. Swedish patients were most liberal on initiation and termination of PEG, NIV and IV. Polish patients were mostly undecided and were least likely to consider discontinuing supportive management. Current use was partly associated with age, gender and state of physical function; also, financial support explained some variance. Future preferences on therapeutic options from the patient’s perspective were also closely associated with cultural factors. The more oriented towards traditional and conservative values, the less likely patients were to decide for invasive therapeutic devices (IV, PEG), the least likely to have ideations to discontinue any device and the more likely to have an undecided attitude.Conclusions: Current use of therapeutic options is determined by medical condition in analogy to clinical guidelines. For future considerations, other factors such as cultural background are crucial, yielding hurdles to be regarded in the implementation of advanced directives in a multicultural environment.
|
|
| 10. |
- Brenner, David, et al.
(author)
-
FUS mutations dominate TBK1 mutations in FUS/TBK1 double-mutant ALS/FTD pedigrees
- 2022
-
In: Neurogenetics. - : Springer. - 1364-6745 .- 1364-6753. ; 23, s. 59-65
-
Journal article (peer-reviewed)abstract
- Mutations in FUS and TBK1 often cause aggressive early-onset amyotrophic lateral sclerosis (ALS) or a late-onset ALS and/or frontotemporal dementia (FTD) phenotype, respectively. Co-occurrence of mutations in two or more Mendelian ALS/FTD genes has been repeatedly reported. However, little is known how two pathogenic ALS/FTD mutations in the same patient interact to shape the final phenotype. We screened 28 ALS patients with a known FUS mutation by whole-exome sequencing and targeted evaluation for mutations in other known ALS genes followed by genotype–phenotype correlation analysis of FUS/TBK1 double-mutant patients. We report on new and summarize previously published FUS and TBK1 double-mutant ALS/FTD patients and their families. We found that, within a family, mutations in FUS cause ALS while TBK1 single mutations are observed in FTD patients. FUS/TBK1 double mutations manifested as ALS and without a manifest difference regarding age at onset and disease duration when compared to FUS single-mutant individuals. In conclusion, TBK1 and FUS variants do not seem to interact in a simple additive way. Rather, the phenotype of FUS/TBK1 double-mutant patients appears to be dominated by the FUS mutation.
|
|
