Novel single-cell RNA-sequencing data demonstrates
upregulation of angiogenesis-associated gene pathways in a
late-stage mouse model of Alzheimer’s disease.
Developing a transcriptomic atlas of Alzheimer’s disease progression in the Tg2576 mouse model using single-cell RNA-sequencing technology
AUTHORS: Kelly Marie Johns
1-8
, Hatice Kubra Kibar
7,8
, Giorgia Caspani
1-8
, Razieh Kamali-Jamil
1-8
, Kyung Bok Choi
1-8
,Chaahat S.B. Singh
1-8
, Maria-Elizabeth Baeva
1-8
, Wing Yan Leung
1-8
, Cheryl G. Pfeifer
1-8
, Anne Haegert
8
, Stephane Le Bihan
8
, Robert
Bell8
, Colin Collins
8
, Nathan Lack
7,8
, and Wilfred A. Jefferies
1-8
AFFILIATIONS: The University of British Columbia: 1) Michael Smith Laboratories, 2) The Djavad Mowafaghian Centre for Brain Health, 3) Centre for Blood Research, 4) Department of Medical Genetics & Genomics, 5) Department of
Microbiology and Immunology, 6) Department of Zoology, 7) Department of Urologic Sciences, 8) The Vancouver Prostate Centre
CONTACT: Wilf Jefferies, wilf@msl.ubc.ca
Created with BioRender Poster Builder
BACKGROUND
● Alzheimer's disease (AD)
is a debilitating
neurodegenerative
condition characterized
by cognitive decline,
progressing to eventual
dementia and death.
● Recent discoveries have
challenged the traditional
“amyloid hypothesis” of
AD, warranting new
approaches and
prospective treatment
agents in the AD
therapeutic pipeline.
● Angiogenesis, the
formation of new blood
vessels, is characteristic
of early AD. Early
evidence suggests that
modulating angiogenesis
may repair damage in the
AD brain, though
transcriptomic data is
currently lacking.
● AIM: to create the frst
single-cell view of AD
progression in mice in
order to identify
alternative mechanisms
of AD pathophysiology,
and reveal putative
molecular targets for AD
drug therapy.
METHODS
● Single-cell RNA-sequencing (scRNA-seq) enables gene expression profling
from individual cells in a tissue to defne the specifc contribution of each
cell to the function of the whole tissue.
● Tg2576 mice contain a mutation in the Amyloid Precursor Protein (APP)
gene which results in a double amino-acid substitution. In Tg2576 mice,
expression of mutated APP reliably causes overexpression of human APP
in neurons, resulting in AD pathophysiology.
Tg2576
Tg2576
Wildtype
Wildtype
Sequencing
x 7 developmental
timepoints
Extract & dissociate brain tissue
Data analysis
Single Cell GEMS
(Gel Bead-In EMulsions)
10x Barcoded
Gel Beads
Cells
Enzyme
Oil
Collect
BBB Disruption
Figure 1: Experimental methods diagram.
Cohorts of four mice representing both AD and control genotypes (Tg2576 and wildtype) and both
sexes (male and female) were humanely euthanized at seven different disease progression
timepoints (N=28). Brains were dissected and dissociated into a single-cell suspension. Individual
cells were captured, and cellular mRNA was sequenced and profled at a single cell resolution. Single￾cell expression data was analyzed using 10X Genomics software. Created with BioRender.com
PRELIMINARY RESULTS
● Pathway analysis demonstrated statistically
signifcant enrichment in pathways related to:
increased angiogenesis (p = 0.0337),
vasculature development (p = 0.0371), and
amyloid-beta (Aβ) formation (p = 0.0149).
Figure 2. Negatively stained transmission electron micrograph of
amyloid fbrils.
Representative microscopy visualizing characteristic amyloid fbrils
in brain tissue from the Tg2576 mouse model of AD. Image source:
Dr. Razieh Kamali-Jamil, unpublished
Figure 3: Cluster diagram for merged AD and wt samples. During
the data analysis process, clusters are formed by grouping cells with
similar transcriptomic profles. (N=28)
CONCLUSION
● This study offers a unique cellular-level
view of transcriptional alterations
associated with AD pathology in mouse
and human tissue. Our methods will
capture:
○ Cell-type-specifc and shared gene￾expression perturbations
○ Disease-associated cellular
subpopulations
○ Sex-biased transcriptional responses.
● Preliminary fndings support the
neurovascular theory of AD
○ Supports growing evidence that
neoangiogenesis-induced disruptions
to blood-brain-barrier integrity lead to
the increase in Aβ accumulation and
subsequent AD pathology seen in
Tg2576 mice and AD patients.
● Next steps:
○ Long-read and deep sequencing on
mouse brain samples to identify
precise splice variants differentially
expressed in AD cells.
○ Knock-out studies in rodent and
neural organoid models of AD to
probe differentially-expressed genes
of interest.
○ Preclinical drug repurposing of
established medications with
angiogenesis-modifying properties
for treatment and prevention of AD
using scRNA-seq as a readout/
endpoint