Abstract Details

Title Increasing SUR1-related pathway activity with increasing injury severity in immune and neurovascular cells after murine TBI

Topic Neuro Trauma and Critical Care

Presentation(s) P8 - Poster Session 8 (11:45 AM-12:45 PM)

Poster/Presentation
Number 9-006

Objective

To evaluate cell-specific changes in sulfonylurea-receptor-1 (SUR1)-transient
receptor melastatin-4 (TRPM4) related pathway gene expression activity and biological
processes by single-cell RNA sequencing (scRNA-Seq) across increasing severity of murine
traumatic brain injury (TBI).

Background

SUR1-TRPM4 inhibition is being evaluated in a phase-II TBI trial, however genes
upstream/downstream of this channel may also be impacted differentially across cell types at
the injury site. We hypothesized that SUR1-TRPM4 pathway gene expression and biological
processes vary with severity, particularly in immune-cells subtypes.

Design/Methods

Murine TBI models of increasing severity included naïve, mild-repetitive-TBI
(mrTBI), Controlled-Cortical Impact (CCI). Dissociated single-cell suspensions from peri-injured
tissue 24h post-TBI underwent scRNA-Seq (10X-Genomics, Illumina), pre-processing
(CellRanger) and quality-control (Seurat). A network of 202 SUR1-related genes was developed
and used to evaluate SUR1-pathway activity (AUCell). Gene expression, biological pathways,
gene-ontology network, cell-communication and pseudotime analyses were assessed (R-
packages).

Results

79,764 cells were sequenced (naïve=26,851, mrTBI=27,380, CCI=25,533), consisting
of 11 cell-types and several subtypes. SUR1-pathway activity was absent in naïve myeloid
cells, mildly increased in some cells after mrTBI, and markedly increased after CCI particularly
in monocyte, microglia, macrophage and neutrophil subtypes. In B- and T-cells, SUR1-pathway
activity was only noted after CCI. Increased SUR1-pathway activity was seen in several
astrocyte- and endothelial-subtypes (limited to CCI). Only one neuronal subtype demonstrated
increased SUR1-pathway activity after CCI. In immune cells S100a8, S100a9, Cxcl2, and Il1b
displayed the highest correlation to SUR1-pathway activity. In astrocytes this was AQP4.
Pseudotime analysis identified lineages specific for higher SUR1-pathway activity in several cell
types. Biological processes associated with SUR1-pathway activity (chemotaxis, differentiation,
apoptosis) were highly variable between celltypes.

Conclusions

SUR1-pathway activity and associated biological processes varied greatly with
TBI severity (maximal in severe TBI), and cell type. These differences should be leveraged to
develop cell-specific biomarkers and targeted pathway modulation/treatment.

Authors/Disclosures
PRESENTER	No disclosure on file
	No disclosure on file
Dhivyaa Rajasundaram (University of Pittsburgh)	Dhivyaa Rajasundaram has nothing to disclose.
Dennis W. Simon, MD (University of Pittsburgh)	Dr. Simon has nothing to disclose.
	No disclosure on file
	No disclosure on file
Shima Shahjouei, MD, MPH (Penn State Health)	Dr. Shahjouei has nothing to disclose.
	No disclosure on file
	No disclosure on file
	No disclosure on file
Jarrod Rulney	Mr. Rulney has nothing to disclose.
	No disclosure on file
	No disclosure on file
	No disclosure on file
	No disclosure on file
	No disclosure on file
	No disclosure on file
Patrick M. Kochanek, MD, MCCM (University of Pittsburgh)	Patrick M. Kochanek, MD, MCCM has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for University of Washington. Patrick M. Kochanek, MD, MCCM has received personal compensation in the range of $10,000-$49,999 for serving as an Expert Witness for Johns Hopkins Health System. Patrick M. Kochanek, MD, MCCM has received personal compensation in the range of $10,000-$49,999 for serving as an Expert Witness for de Boisblanc Law Firm. The institution of Patrick M. Kochanek, MD, MCCM has received research support from Chuck Noll Foundation. The institution of Patrick M. Kochanek, MD, MCCM has received research support from NIH. Patrick M. Kochanek, MD, MCCM has received publishing royalties from a publication relating to health care.
Ruchira M. Jha, MD (Barrow Neurological Institute)	Dr. Jha has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Biogen. An immediate family member of Dr. Jha has received personal compensation in the range of $5,000-$9,999 for serving as an Expert Witness for Legal fees. The institution of Dr. Jha has received research support from NIH/NINDS, Chuck Noll Foundation, University of Pittsburgh, Barrow Neurological Foundation.

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