| 1. |
- Blom, Elin Susanne, et al.
(författare)
-
Low prevalence of APP duplications in Swedish and Finnish patients with early onset Alzheimer's disease
- 2008
-
Ingår i: European Journal of Human Genetics. - : Springer Science and Business Media LLC. - 1018-4813 .- 1476-5438. ; 16:2, s. 171-5
-
Tidskriftsartikel (refereegranskat)abstract
- Familial early-onset Alzheimer's disease with cerebral amyloid angiopathy (EOAD/CAA) was recently associated with duplications of the gene for the amyloid-beta precursor protein (APP). In this study, we have screened for duplications of APP in patients with EOAD from Sweden and Finland. Seventy-five individuals from families with EOAD and 66 individuals with EOAD without known familial inheritance were screened by quantitative PCR. On the basis of the initial results, a portion of the samples was also investigated with quantitative multiplex PCR. No duplications of APP were identified, whereby we conclude that this is not a common cause of EOAD in the Swedish and Finnish populations, at least not in our collection of families and cases.
|
|
| 2. |
- Giedraitis, Vilmantas, et al.
(författare)
-
CALHM1 P86L polymorphism does not alter amyloid-beta or tau in cerebrospinal fluid
- 2010
-
Ingår i: Neuroscience Letters. - : Elsevier BV. - 0304-3940 .- 1872-7972. ; 469:2, s. 265-267
-
Tidskriftsartikel (refereegranskat)abstract
- Recently, the P86L alteration in CALHM1 (calcium homeostasis modulator-1) was reported to be associated with Alzheimer's disease (AD). Moreover, the risk allele increased amyloid-beta (A beta) levels in conditioned media from cultured cells. Therefore, we hypothesized that CALHM1 P86L may modulate A beta or tau levels in cerebrospinal fluid (CSF). Nearly 200 individuals with AD or other cognitive disorders were included for CSF analysis and CALHM1 genotyping. No significant differences in CSF levels of A beta 42, tau or phospho-tau were found across the various CALHM1 genotypes. In conclusion, we found no evidence that CALHM1 P86L is associated with altered CSF levels of the investigated AD biomarkers.
|
|
| 3. |
- Herukka, Sanna-Kaisa, et al.
(författare)
-
Amyloid-beta and Tau Dynamics in Human Brain Interstitial Fluid in Patients with Suspected Normal Pressure Hydrocephalus
- 2015
-
Ingår i: Journal of Alzheimer's Disease. - 1387-2877 .- 1875-8908. ; 46:1, s. 261-269
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Amyloid-beta (A beta(1-42)), total tau (T-tau), and phosphorylated tau (P-tau(181)) in the cerebrospinal fluid (CSF) are the most promising biomarkers of Alzheimer's disease (AD). Still, little is known about the dynamics of these molecules in the living brain. In a transgenic mouse brain, soluble A beta decreases with increasing age and advanced A beta pathology as seen similarly in CSF. Objective: To assess the relationship between AD-related pathological changes in human brain tissue, ventricular and lumbar CSF, and brain interstitial fluid (ISF). Methods: Altogether 11 patients with suspected idiopathic normal pressure hydrocephalus underwent frontal cortical brain biopsy, 24-h intraventricular pressure monitoring, and a microdialysis procedure. AD-related biomarkers were analyzed from brain tissue, CSF, and ISF. Results: ISF T-tau levels decreased strongly within the first 12 h, then plateauing until the end of the experiment. A beta(1-42) and P-tau(181) remained stable during the experiment (n = 3). T-tau and P-tau were higher in the ISF than in ventricular or lumbar CSF, while A beta(1-42) levels were within similar range in both CSF and ISF samples. ISF P-tau correlated with the ventricular CSF T-tau (r = 0.70, p = 0.017) and P-tau(181) (r = 0.64, p = 0.034). Five patients with amyloid pathology in the brain biopsy tended to reveal lower ISF A beta(1-42) levels than those six without amyloid pathology. Conclusions: This is the first study to report ISF A beta and tau levels in the human brain without significant brain injury. The set-up used enables sampling from the brain ISF for at least 24 h without causing adverse effects due to the microdialysis procedure to follow the dynamics of the key molecules in AD pathogenesis in the living brain at various stages of the disease.
|
|
| 4. |
- Jansen, Iris E, et al.
(författare)
-
Genome-wide meta-analysis for Alzheimer's disease cerebrospinal fluid biomarkers.
- 2022
-
Ingår i: Acta neuropathologica. - : Springer Science and Business Media LLC. - 1432-0533 .- 0001-6322. ; 144:5, s. 821-842
-
Tidskriftsartikel (refereegranskat)abstract
- Amyloid-beta 42 (Aβ42) and phosphorylated tau (pTau) levels in cerebrospinal fluid (CSF) reflect core features of the pathogenesis of Alzheimer's disease (AD) more directly than clinical diagnosis. Initiated by the European Alzheimer & Dementia Biobank (EADB), the largest collaborative effort on genetics underlying CSF biomarkers was established, including 31 cohorts with a total of 13,116 individuals (discovery n = 8074; replication n = 5042 individuals). Besides the APOE locus, novel associations with two other well-established AD risk loci were observed; CR1 was shown a locus for Aβ42 and BIN1 for pTau. GMNC and C16orf95 were further identified as loci for pTau, of which the latter is novel. Clustering methods exploring the influence of all known AD risk loci on the CSF protein levels, revealed 4 biological categories suggesting multiple Aβ42 and pTau related biological pathways involved in the etiology of AD. In functional follow-up analyses, GMNC and C16orf95 both associated with lateral ventricular volume, implying an overlap in genetic etiology for tau levels and brain ventricular volume.
|
|
| 5. |
- Kämäläinen, Anna, et al.
(författare)
-
GRN Variant rs5848 Reduces Plasma and Brain Levels of Granulin in Alzheimer's Disease Patients.
- 2013
-
Ingår i: Journal of Alzheimer's disease : JAD. - 1875-8908. ; 33:1, s. 23-7
-
Tidskriftsartikel (refereegranskat)abstract
- Genetic variants in the granulin (GRN) gene have been shown to increase the risk of Alzheimer's disease (AD). Here, we report that the A allele of rs5848 in GRN reduces plasma granulin levels in a dose-dependent manner in a clinically-defined AD sample cohort. Similarly, the mRNA levels of granulin were decreased with respect to A allele of rs5848 in the inferior temporal cortex of neuropathologically confirmed AD patients. Our findings suggest that the A allele of rs5848 is functionally relevant by reducing the expression of granulin.
|
|
| 6. |
- Laitera, Tiina, et al.
(författare)
-
The Expression of Transthyretin and Amyloid-beta Protein Precursor is Altered in the Brain of Idiopathic Normal Pressure Hydrocephalus Patients
- 2015
-
Ingår i: Journal of Alzheimer's Disease. - 1387-2877 .- 1875-8908. ; 48:4, s. 959-968
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Idiopathic normal pressure hydrocephalus (iNPH) is a dementing condition in which Alzheimer's disease (AD)related amyloid-beta (A beta) plaques are frequently observed in the neocortex. iNPH patients with prominent A beta pathology show AD-related alterations in amyloid-beta protein precursor (A beta PP) processing resulting from increased gamma-secretase activity. Objectives: Our goal was to assess potential alterations in the global gene expression profile in the brain of iNPH patients as compared to non-demented controls and to evaluate the levels of the identified targets in the cerebrospinal fluid (CSF) of iNPH patients. Methods: The genome-wide expression profile of similar to 35,000 probes was assessed in the RNA samples obtained from 22 iNPH patients and eight non-demented control subjects using a microarray chip. The soluble levels of sA beta PP alpha, sA beta PP beta, and transthyretin (TTR) were measured from the CSF of 102 iNPH patients using ELISA. Results: After correcting the results for multiple testing, significant differences in the expression of TTR and A beta PP were observed between iNPH and control subjects. The mRNA levels of TTR were on average 17-fold lower in iNPH samples compared to control samples. Conversely, the expression level of A beta PP was on average three times higher in iNPH samples as compared to control samples. Interestingly, the expression of beta-secretase (ADAM10) was also increased in iNPH patients. In the lumbar CSF samples, soluble TTR levels showed a significant positive correlation with sA beta PP alpha and sA beta PP beta, but TTR levels did not predict the brain pathology or the shunt response. Conclusions: These findings suggest differences in the expression profile of key factors involved in AD-related cellular events in the brain of iNPH patients.
|
|
| 7. |
- Laiterä, Tiina, et al.
(författare)
-
Effects of Alzheimer's Disease-Associated Risk Loci on Amyloid-β Accumulation in the Brain of Idiopathic Normal Pressure Hydrocephalus Patients
- 2017
-
Ingår i: Journal of Alzheimer's Disease. - 1387-2877 .- 1875-8908. ; 55:3, s. 995-1003
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Idiopathic normal pressure hydrocephalus (iNPH) is a dementing condition featuring characteristic symptoms, ventriculomegaly, and normal or slightly elevated cerebrospinal fluid pressure. In Alzheimer's disease (AD) patients, diffuse aggregates of amyloid-β (Aβ) and neurofibrillary hyperphosphorylated tau are detected in the neocortex of the brain, while similar accumulation of Aβ is also detected in iNPH. Recent genome-wide association studies have identified several novel risk loci for AD, potentially affecting Aβ-related cellular processes. Apart from the apolipoprotein E ɛ4 allele (APOE4), the risk effect of single loci is low, emphasizing the importance of the polygenic risk score approach when assessing the combined effects.OBJECTIVE: To study the effects of AD-associated individual and polygenic risk score of single nucleotide polymorphisms (SNPs) on the accumulation of Aβ in the brain samples of iNPH patients.METHODS: A sample set of frontal cortex biopsies from 188 iNPH patients were divided into two groups according to the Aβ pathology. After the genotyping of the AD-associated risk loci, polygenic risk score was calculated for each iNPH patient and subsequently analyzed in relation to Aβ deposition.RESULTS: Apart from the APOE4, none of the SNPs revealed a statistically significant effect on the accumulation of Aβ in iNPH. Also, the non-APOE4 polygenic risk score did not associate with Aβ deposition.CONCLUSION: Novel AD-associated risk genes have no significant effect on Aβ accumulation in the brain of iNPH patients. However, APOE4 affects the Aβ deposition in the brain of iNPH and AD patients in a similar manner.
|
|
| 8. |
|
|
| 9. |
- Lambert, Jean-Charles, et al.
(författare)
-
The CALHM1 P86L Polymorphism is a Genetic Modifier of Age at Onset in Alzheimer's Disease : a Meta-Analysis Study
- 2010
-
Ingår i: Journal of Alzheimer's Disease. - 1387-2877 .- 1875-8908. ; 22:1, s. 247-255
-
Tidskriftsartikel (refereegranskat)abstract
- The only established genetic determinant of non-Mendelian forms of Alzheimer's disease (AD) is the epsilon 4 allele of the apolipoprotein E gene (APOE). Recently, it has been reported that the P86L polymorphism of the calcium homeostasis modulator 1 gene (CALHM1) is associated with the risk of developing AD. In order to independently assess this association, we performed a meta-analysis of 7,873 AD cases and 13,274 controls of Caucasian origin (from a total of 24 centers in Belgium, Finland, France, Italy, Spain, Sweden, the UK, and the USA). Our results indicate that the CALHM1 P86L polymorphism is likely not a genetic determinant of AD but may modulate age of onset by interacting with the effect of the epsilon 4 allele of the APOE gene.
|
|
| 10. |
- Luikku, Antti J., et al.
(författare)
-
Multimodal analysis to predict shunt surgery outcome of 284 patients with suspected idiopathic normal pressure hydrocephalus
- 2016
-
Ingår i: Acta Neurochirurgica. - : Springer Science and Business Media LLC. - 0001-6268 .- 0942-0940. ; 158:12, s. 2311-2319
-
Tidskriftsartikel (refereegranskat)abstract
- Optimal selection of idiopathic normal pressure hydrocephalus (iNPH) patients for shunt surgery is challenging. Disease State Index (DSI) is a statistical method that merges multimodal data to assist clinical decision-making. It has previously been shown to be useful in predicting progression in mild cognitive impairment and differentiating Alzheimer's disease (AD) and frontotemporal dementia. In this study, we use the DSI method to predict shunt surgery response for patients with iNPH. In this retrospective cohort study, a total of 284 patients (230 shunt responders and 54 non-responders) from the Kuopio NPH registry were analyzed with the DSI. Analysis included data from patients' memory disorder assessments, age, clinical symptoms, comorbidities, medications, frontal cortical biopsy, CT/MRI imaging (visual scoring of disproportion between Sylvian and suprasylvian subarachnoid spaces, atrophy of medial temporal lobe, superior medial subarachnoid spaces), APOE genotyping, CSF AD biomarkers, and intracranial pressure. Our analysis showed that shunt responders cannot be differentiated from non-responders reliably even with the large dataset available (AUC = 0.58). Prediction of the treatment response in iNPH is challenging even with our extensive dataset and refined analysis. Further research of biomarkers and indicators predicting shunt responsiveness is still needed.
|
|
