Next-Generation RNA-Sequencing of Serum Small Extracellular Vesicles Discovers Potential Diagnostic Biomarkers for Dementia With Lewy Bodies

Anto P. Rajkumar; Abdul Hye; Johannes Lange; Yazmin Rashid Manesh; Clive Ballard; Tormod Fladby; Dag Aarsland

doi:10.1016/j.jagp.2020.10.012

Next-Generation RNA-Sequencing of Serum Small Extracellular Vesicles Discovers Potential Diagnostic Biomarkers for Dementia With Lewy Bodies

Anto P. Rajkumar^*, Abdul Hye, Johannes Lange, Yazmin Rashid Manesh, Clive Ballard, Tormod Fladby, Dag Aarsland

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

6 Citations (Scopus)

Abstract

Objective: There is an urgent clinical need for identifying blood-based diagnostic biomarkers for Dementia with Lewy Bodies (DLB). Transcriptomic studies have reported unique RNA changes in postmortem DLB brains. Small extracellular vesicles (SEV) that transport RNA between brain and peripheral circulation enable identifying molecular changes in living human brain. Hence, we aimed to identify differentially expressed RNA in serum SEVs from people with DLB. Methods: We investigated serum SEV total RNA profiles in people with DLB (n = 10) and age and gender matched comparisons (n = 10) using next-generation RNA-sequencing. SEVs were separated by ultracentrifugation with density gradient and were characterized by nanoparticle analysis and western blotting. We verified the differential expression levels of identified differentially expressed genes (DEG) using high-throughput qPCR. Functional implications of identified DEG were evaluated using Ingenuity pathway analyses. Results: We identified 846 nominally significant DEG including 30 miRNAs in DLB serum SEVs. We identified significant downregulation of proinflammatory genes, IL1B, CXCL8, and IKBKB. Previously reported postmortem DLB brain DEGs were significantly enriched (χ²=4.99; df=1; p = 0.03) among the identified DEGs, and the differential expression of 40 postmortem DLB brain DEGs could be detected in serum SEVs of people living with DLB. Functional pathway and network analyses highlighted the importance of immunosenescence, ubiquitin proteasome system (UPS) dysfunction, DNA repair, and RNA post-transcriptional modification deficits in DLB pathology. Conclusion: Identified DEGs, especially reduced expression levels of inflammation, and UPS-associated RNA, may aid diagnosing DLB, and their biomarker potential warrants further investigation in larger clinical cohorts. Our findings corroborate the absence of chronic neuroinflammation in DLB.

Original language	English
Journal	American Journal of Geriatric Psychiatry
DOIs	https://doi.org/10.1016/j.jagp.2020.10.012
Publication status	Accepted/In press - 2020

Keywords

biomarkers
exosomes
high-throughput RNA sequencing
Lewy body dementia
quantitative real-time polymerase chain reaction

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

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10.1016/j.jagp.2020.10.012

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@article{093d2fb4d9af433a98b11ef7a7cfab06,

title = "Next-Generation RNA-Sequencing of Serum Small Extracellular Vesicles Discovers Potential Diagnostic Biomarkers for Dementia With Lewy Bodies",

abstract = "Objective: There is an urgent clinical need for identifying blood-based diagnostic biomarkers for Dementia with Lewy Bodies (DLB). Transcriptomic studies have reported unique RNA changes in postmortem DLB brains. Small extracellular vesicles (SEV) that transport RNA between brain and peripheral circulation enable identifying molecular changes in living human brain. Hence, we aimed to identify differentially expressed RNA in serum SEVs from people with DLB. Methods: We investigated serum SEV total RNA profiles in people with DLB (n = 10) and age and gender matched comparisons (n = 10) using next-generation RNA-sequencing. SEVs were separated by ultracentrifugation with density gradient and were characterized by nanoparticle analysis and western blotting. We verified the differential expression levels of identified differentially expressed genes (DEG) using high-throughput qPCR. Functional implications of identified DEG were evaluated using Ingenuity pathway analyses. Results: We identified 846 nominally significant DEG including 30 miRNAs in DLB serum SEVs. We identified significant downregulation of proinflammatory genes, IL1B, CXCL8, and IKBKB. Previously reported postmortem DLB brain DEGs were significantly enriched (χ2=4.99; df=1; p = 0.03) among the identified DEGs, and the differential expression of 40 postmortem DLB brain DEGs could be detected in serum SEVs of people living with DLB. Functional pathway and network analyses highlighted the importance of immunosenescence, ubiquitin proteasome system (UPS) dysfunction, DNA repair, and RNA post-transcriptional modification deficits in DLB pathology. Conclusion: Identified DEGs, especially reduced expression levels of inflammation, and UPS-associated RNA, may aid diagnosing DLB, and their biomarker potential warrants further investigation in larger clinical cohorts. Our findings corroborate the absence of chronic neuroinflammation in DLB.",

keywords = "biomarkers, exosomes, high-throughput RNA sequencing, Lewy body dementia, quantitative real-time polymerase chain reaction",

author = "Rajkumar, {Anto P.} and Abdul Hye and Johannes Lange and Manesh, {Yazmin Rashid} and Clive Ballard and Tormod Fladby and Dag Aarsland",

year = "2020",

doi = "10.1016/j.jagp.2020.10.012",

language = "English",

journal = "American Journal of Geriatric Psychiatry",

issn = "1064-7481",

}

TY - JOUR

T1 - Next-Generation RNA-Sequencing of Serum Small Extracellular Vesicles Discovers Potential Diagnostic Biomarkers for Dementia With Lewy Bodies

AU - Rajkumar, Anto P.

AU - Hye, Abdul

AU - Lange, Johannes

AU - Manesh, Yazmin Rashid

AU - Ballard, Clive

AU - Fladby, Tormod

AU - Aarsland, Dag

PY - 2020

Y1 - 2020

N2 - Objective: There is an urgent clinical need for identifying blood-based diagnostic biomarkers for Dementia with Lewy Bodies (DLB). Transcriptomic studies have reported unique RNA changes in postmortem DLB brains. Small extracellular vesicles (SEV) that transport RNA between brain and peripheral circulation enable identifying molecular changes in living human brain. Hence, we aimed to identify differentially expressed RNA in serum SEVs from people with DLB. Methods: We investigated serum SEV total RNA profiles in people with DLB (n = 10) and age and gender matched comparisons (n = 10) using next-generation RNA-sequencing. SEVs were separated by ultracentrifugation with density gradient and were characterized by nanoparticle analysis and western blotting. We verified the differential expression levels of identified differentially expressed genes (DEG) using high-throughput qPCR. Functional implications of identified DEG were evaluated using Ingenuity pathway analyses. Results: We identified 846 nominally significant DEG including 30 miRNAs in DLB serum SEVs. We identified significant downregulation of proinflammatory genes, IL1B, CXCL8, and IKBKB. Previously reported postmortem DLB brain DEGs were significantly enriched (χ2=4.99; df=1; p = 0.03) among the identified DEGs, and the differential expression of 40 postmortem DLB brain DEGs could be detected in serum SEVs of people living with DLB. Functional pathway and network analyses highlighted the importance of immunosenescence, ubiquitin proteasome system (UPS) dysfunction, DNA repair, and RNA post-transcriptional modification deficits in DLB pathology. Conclusion: Identified DEGs, especially reduced expression levels of inflammation, and UPS-associated RNA, may aid diagnosing DLB, and their biomarker potential warrants further investigation in larger clinical cohorts. Our findings corroborate the absence of chronic neuroinflammation in DLB.

AB - Objective: There is an urgent clinical need for identifying blood-based diagnostic biomarkers for Dementia with Lewy Bodies (DLB). Transcriptomic studies have reported unique RNA changes in postmortem DLB brains. Small extracellular vesicles (SEV) that transport RNA between brain and peripheral circulation enable identifying molecular changes in living human brain. Hence, we aimed to identify differentially expressed RNA in serum SEVs from people with DLB. Methods: We investigated serum SEV total RNA profiles in people with DLB (n = 10) and age and gender matched comparisons (n = 10) using next-generation RNA-sequencing. SEVs were separated by ultracentrifugation with density gradient and were characterized by nanoparticle analysis and western blotting. We verified the differential expression levels of identified differentially expressed genes (DEG) using high-throughput qPCR. Functional implications of identified DEG were evaluated using Ingenuity pathway analyses. Results: We identified 846 nominally significant DEG including 30 miRNAs in DLB serum SEVs. We identified significant downregulation of proinflammatory genes, IL1B, CXCL8, and IKBKB. Previously reported postmortem DLB brain DEGs were significantly enriched (χ2=4.99; df=1; p = 0.03) among the identified DEGs, and the differential expression of 40 postmortem DLB brain DEGs could be detected in serum SEVs of people living with DLB. Functional pathway and network analyses highlighted the importance of immunosenescence, ubiquitin proteasome system (UPS) dysfunction, DNA repair, and RNA post-transcriptional modification deficits in DLB pathology. Conclusion: Identified DEGs, especially reduced expression levels of inflammation, and UPS-associated RNA, may aid diagnosing DLB, and their biomarker potential warrants further investigation in larger clinical cohorts. Our findings corroborate the absence of chronic neuroinflammation in DLB.

KW - biomarkers

KW - exosomes

KW - high-throughput RNA sequencing

KW - Lewy body dementia

KW - quantitative real-time polymerase chain reaction

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U2 - 10.1016/j.jagp.2020.10.012

DO - 10.1016/j.jagp.2020.10.012

M3 - Article

C2 - 33160816

AN - SCOPUS:85096399637

SN - 1064-7481

JO - American Journal of Geriatric Psychiatry

JF - American Journal of Geriatric Psychiatry

ER -

Next-Generation RNA-Sequencing of Serum Small Extracellular Vesicles Discovers Potential Diagnostic Biomarkers for Dementia With Lewy Bodies

Abstract

Keywords

UN SDGs

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