scholarly journals Integrated proteomics reveals brain-based cerebrospinal fluid biomarkers in asymptomatic and symptomatic Alzheimer’s disease

2020 ◽  
Vol 6 (43) ◽  
pp. eaaz9360 ◽  
Author(s):  
Lenora Higginbotham ◽  
Lingyan Ping ◽  
Eric B. Dammer ◽  
Duc M. Duong ◽  
Maotian Zhou ◽  
...  

Alzheimer’s disease (AD) lacks protein biomarkers reflective of its diverse underlying pathophysiology, hindering diagnostic and therapeutic advancements. Here, we used integrative proteomics to identify cerebrospinal fluid (CSF) biomarkers representing a wide spectrum of AD pathophysiology. Multiplex mass spectrometry identified ~3500 and ~12,000 proteins in AD CSF and brain, respectively. Network analysis of the brain proteome resolved 44 biologically diverse modules, 15 of which overlapped with the CSF proteome. CSF AD markers in these overlapping modules were collapsed into five protein panels representing distinct pathophysiological processes. Synaptic and metabolic panels were decreased in AD brain but increased in CSF, while glial-enriched myelination and immunity panels were increased in brain and CSF. The consistency and disease specificity of panel changes were confirmed in >500 additional CSF samples. These panels also identified biological subpopulations within asymptomatic AD. Overall, these results are a promising step toward a network-based biomarker tool for AD clinical applications.

2019 ◽  
Author(s):  
Lenora Higginbotham ◽  
Lingyan Ping ◽  
Eric B. Dammer ◽  
Duc M. Duong ◽  
Maotian Zhou ◽  
...  

AbstractAlzheimer’s disease (AD) features a complex web of pathological processes beyond amyloid accumulation and tau-mediated neuronal death. To meaningfully advance AD therapeutics, there is an urgent need for novel biomarkers that comprehensively reflect these disease mechanisms. Here we applied an integrative proteomics approach to identify cerebrospinal fluid (CSF) biomarkers linked to a diverse set of pathophysiological processes in the diseased brain. Using multiplex proteomics, we identified >3,500 proteins across 40 CSF samples from control and AD patients and >12,000 proteins across 48 postmortem brain tissues from control, asymptomatic AD (AsymAD), AD, and other neurodegenerative cases. Co-expression network analysis of the brain tissues resolved 44 protein modules, nearly half of which significantly correlated with AD neuropathology. Fifteen modules robustly overlapped with proteins quantified in the CSF, including 271 CSF markers highly altered in AD. These 15 overlapping modules were collapsed into five panels of brain-linked fluid markers representing a variety of cortical functions. Neuron-enriched synaptic and metabolic panels demonstrated decreased levels in the AD brain but increased levels in diseased CSF. Conversely, glial-enriched myelination and immunity panels were highly increased in both the brain and CSF. Using high-throughput proteomic analysis, proteins from these panels were validated in an independent CSF cohort of control, AsymAD, and AD samples. Remarkably, several validated markers were significantly altered in AsymAD CSF and appeared to stratify subpopulations within this cohort. Overall, these brain-linked CSF biomarker panels represent a promising step toward a physiologically comprehensive tool that could meaningfully enhance the prognostic and therapeutic management of AD.


2021 ◽  
pp. 1-14
Author(s):  
Christiana Bjorkli ◽  
Claire Louet ◽  
Trude Helen Flo ◽  
Mary Hemler ◽  
Axel Sandvig ◽  
...  

Background: Preclinical models of Alzheimer’s disease (AD) can provide valuable insights into the onset and progression of the disease, such as changes in concentrations of amyloid-β (Aβ) and tau in cerebrospinal fluid (CSF). However, such models are currently underutilized due to limited advancement in techniques that allow for longitudinal CSF monitoring. Objective: An elegant way to understand the biochemical environment in the diseased brain is intracerebral microdialysis, a method that has until now been limited to short-term observations, or snapshots, of the brain microenvironment. Here we draw upon patient-based findings to characterize CSF biomarkers in a commonly used preclinical mouse model for AD. Methods: Our modified push-pull microdialysis method was first validated ex vivo with human CSF samples, and then in vivo in an AD mouse model, permitting assessment of dynamic changes of CSF Aβ and tau and allowing for better translational understanding of CSF biomarkers. Results: We demonstrate that CSF biomarker changes in preclinical models capture what is observed in the brain; with a decrease in CSF Aβ observed when plaques are deposited, and an increase in CSF tau once tau pathology is present in the brain parenchyma. We found that a high molecular weight cut-off membrane allowed for simultaneous sampling of Aβ and tau, comparable to CSF collection by lumbar puncture in patients. Conclusion: Our approach can further advance AD and other neurodegenerative research by following evolving neuropathology along the disease cascade via consecutive sampling from the same animal and can additionally be used to administer pharmaceutical compounds and assess their efficacy (Bjorkli, unpublished data).


2013 ◽  
Vol 8 ◽  
pp. BMI.S11422 ◽  
Author(s):  
Chera L. Maarouf ◽  
Thomas G. Beach ◽  
Charles H. Adler ◽  
Michael Malek-Ahmadi ◽  
Tyler A. Kokjohn ◽  
...  

Identifying biomarkers that distinguish Parkinson's disease (PD) from normal control (NC) individuals has the potential to increase diagnostic sensitivity for the detection of early-stage PD. A previous proteomic study identified potential biomarkers in postmortem ventricular cerebrospinal fluid (V-CSF) from neuropathologically diagnosed PD subjects lacking Alzheimer's disease (AD) neuropathology. In the present study, we assessed these biomarkers as well as p-tau181, Aβ42, and S100B by ELISA in PD (n = 43) and NC (n = 49) cases. The p-tau181/Aβ42 ratio and ApoA-1 showed statistically significant differences between groups. Multiple regression analysis demonstrated that p-tau181/Aβ42 had a significant odds ratio: OR = 1.42 (95% confidence interval [CI], 1.12–1.84), P = 0.006. Among the molecules investigated, intriguing correlations were observed that require further investigation. Our results suggest coexistent AD CSF biomarkers within the PD group notwithstanding that it was selected to minimize AD neuropathological lesions.


2018 ◽  
Vol 46 (1-2) ◽  
pp. 90-99 ◽  
Author(s):  
Lena Johansson ◽  
Silke Kern ◽  
Henrik Zetterberg ◽  
Kaj Blennow ◽  
Anne Börjesson-Hansson ◽  
...  

Background/Aims: Psychological stress has previously been associated with higher risk of developing late-life dementia, especially Alzheimer’s disease (AD). This study tested whether longstanding midlife stress is related to cerebrospinal fluid (CSF) biomarkers of late-life AD, such as tau protein and amyloid beta (Aβ). Methods: The study included 79 nondemented females from the Prospective Population Study of Women in Gothenburg, Sweden, who responded to a standardized stress question at baseline (mean age 49 years) and underwent a lumbar puncture at follow-up 25 years later. Multiple linear regression models analyzed the relationships between midlife psychological stress and late-life CSF measures of total tau (t-tau), phosphorylated tau (p-tau), Aβ40, and Aβ42. Results: Longstanding stress in midlife was associated with higher levels of CSF t-tau (β = 0.64, p = 0.01) and Aβ40 (β = 0.60, p = 0.02) in late life. No associations were found between midlife stress and levels of p-tau or Aβ42. Conclusion: The findings suggest that longstanding stress stimulates unspecific neurodegenerative processes, but not the core processes of AD, at least not in the early phase of the disease. The association with higher concentration of CSF t-tau may reflect neural degeneration and the association with higher Aβ40 may be an early sign of Aβ overproduction or cerebrovascular processes in the brain.


2015 ◽  
Vol 31 (1) ◽  
pp. 34-41
Author(s):  
Imran Sarker ◽  
Md Rezaul Karim Khan ◽  
Anisul Haque ◽  
Md Rafiqul Islam

Alzheimer’s disease is the most common cause of dementia among elderly people. The major pathological hallmarks of AD are the loss of neurons, occurrence of extracellular senile plaques as well as intracellular neurofibrillary tangles (NFT). Biochemical changes in the brain are reflected in the cerebrospinal fluid (CSF), and intense research efforts have been made to develop biomarkers for the central pathogenic processes in AD that can be used as diagnostic tools. Biomarkers are essential part of disease management as they are essential for diagnosis, monitoring the disease progression, detecting early onset of the disease, monitoring the effect of therapeutic intervention, and also avoiding false diagnosis of the disease. Unfortunately, none of the biomarkers presently available are able to accomplish the disease diagnosis single-handedly. Three CSF biomarkers, Aâ42, Total-tau (t-tau), and phosphorylated-tau (p-tau), have been found to have the highest diagnostic potential. Bangladesh Journal of Neuroscience 2015; Vol. 31 (1): 34-41


2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Shahzad Ahmad ◽  
Adelina Orellana ◽  
Isabelle Kohler ◽  
Lutz Frölich ◽  
Itziar de Rojas ◽  
...  

Abstract Background Lysophosphatidic acids (LPAs) are bioactive signaling phospholipids that have been implicated in Alzheimer’s disease (AD). It is largely unknown whether LPAs are associated with AD pathology and progression from mild cognitive impairment (MCI) to AD. Methods The current study was performed on cerebrospinal fluid (CSF) and plasma samples of 182 MCI patients from two independent cohorts. We profiled LPA-derived metabolites using liquid chromatography-mass spectrometry. We evaluated the association of LPAs with CSF biomarkers of AD, Aβ-42, p-tau, and total tau levels overall and stratified by APOE genotype and with MCI to AD progression. Results Five LPAs (C16:0, C16:1, C22:4, C22:6, and isomer-LPA C22:5) showed significant positive association with CSF biomarkers of AD, Aβ-42, p-tau, and total tau, while LPA C14:0 and C20:1 associated only with Aβ-42 and alkyl-LPA C18:1, and LPA C20:1 associated with tau pathology biomarkers. Association of cyclic-LPA C16:0 and two LPAs (C20:4, C22:4) with Aβ-42 levels was found only in APOE ε4 carriers. Furthermore, LPA C16:0 and C16:1 also showed association with MCI to AD dementia progression, but results did not replicate in an independent cohort. Conclusions Our findings provide evidence that LPAs may contribute to early AD pathogenesis. Future studies are needed to determine whether LPAs play a role in upstream of AD pathology or are downstream markers of neurodegeneration.


2015 ◽  
Vol 40 (1-2) ◽  
pp. 54-62 ◽  
Author(s):  
Nina Rostgaard ◽  
Gunhild Waldemar ◽  
Jørgen Erik Nielsen ◽  
Anja Hviid Simonsen

As dementia is a fast-growing health care problem, it is becoming an increasingly urgent need to provide an early diagnosis in order to offer patients the best medical treatment and care. Validated biomarkers which reflect the pathology and disease progression are essential for diagnosis and are important when developing new therapies. Today, the core protein biomarkers amyloid-β42, total tau and phosphorylated tau in the cerebrospinal fluid (CSF) are used to diagnose Alzheimer's disease (AD), because these biomarkers have shown to reflect the underlying amyloid and tau pathology. However, the biomarkers have proved insufficient predictors of dementias with a different pathology, e.g. frontotemporal dementia (FTD); furthermore, the biomarkers are not useful for early AD diagnosis. Familial dementias with a known disease-causing mutation can be extremely valuable to study; yet the biomarker profiles in patients with familial dementias are not clear. This review summarizes CSF biomarker findings from studies on symptomatic and presymptomatic individuals carrying a mutation in one of the genes known to cause early-onset familial AD or FTD. In conclusion, the biomarker profile of inherited AD is quite similar between carriers of different mutations as well as similar to the profile found in sporadic AD, whereas familial FTD does not seem to have a clear biomarker profile. Hence, new biomarkers are needed for FTD.


2021 ◽  
pp. 1-6
Author(s):  
Jagan A. Pillai ◽  
James Bena ◽  
Lynn M. Bekris ◽  
Nancy Foldvary-Schaefer ◽  
Catherine Heinzinger ◽  
...  

Sleep dysfunction has been identified in the pathophysiology of Alzheimer’s disease (AD); however, the role and mechanism of circadian rhythm dysfunction is less well understood. In a well-characterized cohort of patients with AD at the mild cognitive impairment stage (MCI-AD), we identify that circadian rhythm irregularities were accompanied by altered humoral immune responses detected in both the cerebrospinal fluid and plasma as well as alterations of cerebrospinal fluid biomarkers of neurodegeneration. On the other hand, sleep disruption was more so associated with abnormalities in circulating markers of immunity and inflammation and decrements in cognition.


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