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- Rani, Komal, et al.
(författare)
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A novel approach to correlate the salivary exosomes and their protein cargo in the progression of cognitive impairment into Alzheimer’s disease
- 2021
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Ingår i: Journal of Neuroscience Methods. - : Elsevier. - 0165-0270 .- 1872-678X. ; 347
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundCognition is the ability of a person to think, remember, and interconnect ideas from various dimensions to strive for solutions. Cognitive defects accompany all forms of dementia and the decline in cognition is a most feared aspect. Mild cognitive impairment is considered as a transitional phase and the progressive loss in cognition can finally lead to Alzheimer’s disease.New MethodIn this study, we demonstrated a novel method based on nanoparticle tracking analysis (NTA) technique to directly correlate salivary exosomes concentration with the progression of cognitive impairment (CI) in Alzheimer’s disease (AD).This could open up the possibility for an early and cost-effective screening of Alzheimer's disease.ResultsUsing our novel method, the total salivary exosomes concentration was measured by NTA technique, followed by validation of key exosomal cargo proteins through an automated western blot analyzer. We observed significant differences in salivary exosomes concentration among the groups of cognitively impaired and Alzheimer’s disease patients (p = 0.0023) compared to the healthy control cohort. The method was validated through CD63 (exosomes surface marker) fluorescent antibody based quantification, which yielded a similar outcome (p = 0.0286). We further corroborated our findings with the expression level of oligomeric amyloid-beta, phosphorylated-tau protein from salivary exosomes. The Aβ oligomer/fibril abundance (p = 0.0291), phospho-tau (p = 0.0325) and Aβ protein abundance (p = 0.0198) was significantly higher in Alzheimer’s and cognitively impaired patients in comparison to the healthy controls.Comparison with Existing Method(s)There are few molecular biomarkers available to differentiate between various stages of cognitive impairment. Moreover, the current methodologies utilizing the few biomarkers available are either invasive or expensive; also, for a patient with mild cognitive complains, it is impractical to use these as a screening tool.ConclusionOur initial results indicate that the salivary exosomes concentration based on the nano-tracking technique has the potential to be used as a cost-effective screening method for early disease detection.
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| 3. |
- Rastogi, Simran, et al.
(författare)
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Fluorescence-tagged salivary small extracellular vesicles as a nanotool in early diagnosis of Parkinson’s disease
- 2023
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Ingår i: BMC Medicine. - : Springer Nature. - 1741-7015. ; 21
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Tidskriftsartikel (refereegranskat)abstract
- Background: Parkinson’s disease is generally asymptomatic at earlier stages. At an early stage, there is an extensive progression in the neuropathological hallmarks, although, at this stage, diagnosis is not possible with currently available diagnostic methods. Therefore, the pressing need is for susceptibility risk biomarkers that can aid in better diagnosis and therapeutics as well can objectively serve to measure the endpoint of disease progression. The role of small extracellular vesicles (sEV) in the progression of neurodegenerative diseases could be potent in playing a revolutionary role in biomarker discovery.Methods: In our study, the salivary sEV were efficiently isolated by chemical precipitation combined with ultrafiltration from subjects (PD = 70, healthy controls = 26, and prodromal PD = 08), followed by antibody-based validation with CD63, CD9, GAPDH, Flotillin-1, and L1CAM. Morphological characterization of the isolated sEV through transmission electron microscopy. The quantification of sEV was achieved by fluorescence (lipid-binding dye-labeled) nanoparticle tracking analysis and antibody-based (CD63 Alexa fluor 488 tagged sEV) nanoparticle tracking analysis. The total alpha-synuclein (α-synTotal) in salivary sEVs cargo was quantified by ELISA. The disease severity staging confirmation for n = 18 clinically diagnosed Parkinson’s disease patients was done by 99mTc-TRODAT-single-photon emission computed tomography.Results: We observed a significant increase in total sEVs concentration in PD patients than in the healthy control (HC), where fluorescence lipid-binding dye-tagged sEV were observed to be higher in PD (p = 0.0001) than in the HC using NTA with a sensitivity of 94.34%. In the prodromal PD cases, the fluorescence lipid-binding dye-tagged sEV concentration was found to be higher (p = 0.008) than in HC. This result was validated through anti-CD63 tagged sEV (p = 0.0006) with similar sensitivity of 94.12%. We further validated our findings with the ELISA based on α-synTotal concentration in sEV, where it was observed to be higher in PD (p = 0.004) with a sensitivity of 88.24%. The caudate binding ratios in 99mTc-TRODAT-SPECT represent a positive correlation with sEV concentration (r = 0.8117 with p = 0.0112).Conclusions: In this study, for the first time, we have found that the fluorescence-tagged sEV has the potential to screen the progression of disease with clinically acceptable sensitivity and can be a potent early detection method for PD.
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