# Integration of single-cell imaging and multi-omics sequencing to study EC mechano-pathophysiology

> **NIH NIH R01** · UNIVERSITY OF SOUTHERN CALIFORNIA · 2024 · $583,656

## Abstract

Endothelial cells (ECs) play a critical role in regulating vascular functions. We and others have demonstrated
that, through epigenetic and transcriptional regulations, laminar pulsatile shear stress (PS) induces athero-
protective genes to maintain EC homeostasis, whereas disturbed flow with oscillatory shear (OS) elevates
athero-prone genes to cause EC dysfunctions. We have performed single-cell RNA sequencing (scRNA-seq)
analyses to demonstrate that the transcriptomic effects of PS are distinct from those of OS. In addition, we have
shown that PS caused enrichments of histone active mark (H3K27ac) at genes related to EC homeostasis and
histone repressing mark (H3K9me3) at genes related to inflammation. We also demonstrated that the PS-
induced H3K9me3 is dependent on the nuclear envelop proteins lamin/emerin. These findings have led to our
hypothesis that PS and OS modulate EC functions through the coupling of lamin/emerin and chromatin to recruit
histone modifiers, thus leading to differential changes in histone epigenetics and the associated genomic and
transcriptomic regulations, and hence the opposite functional outcomes. The couplings between lamin/emerin
and chromatin/genome can transduce the mechanical signals from physical space into genome space for gene
and cell fate regulations. In order to test our hypothesis, we will conduct ChIP-seq to identify the lamin/emerin
associated genome regions (LEAGRs) under PS and OS, and determine the LEAGR-associated histone
modifications (i.e., epigenome). To visualize the differential flow-modulations of the dynamic interaction between
LEAGRs and lamin/emerin in single live cells, we will employ endonuclease-deficient Cas9 (dCas9) together
with small guide RNAs (sgRNAs) and engineered biosensors to track the dynamics of the histone profiles of
these genomic loci, particularly those related to EC homeostasis or inflammation. We will then determine the
roles of the locus-specific epigenetic profiles in regulating the transcriptome and cellular functions under different
flows. We will conduct studies in vivo on aorta arch (OS) and thoracic aorta (PS) in mice to validate our in vitro
results, and assess their impacts on atherogenesis by using atherosclerotic mouse models. Specifically, the MR
(magnetic resonance)-guided FUS (focused ultrasound) (MRg-FUS) system will be used to remotely and
noninvasively activate the inducible shRNA and CRISPRa/i (CRISPR activation or interference) systems to
manipulate lamin/emerin and locus-specific histone epigenetics at local tissue areas of mouse with partially
ligated carotid arteries to examine their functional roles in vivo. Accordingly, three specific aims are proposed: 1)
In vitro investigation of lamin/emerin and EC epigenome/transcriptome under different flows, 2) Imaging of locus-
specific epigenetic and chromatin remodeling in single live ECs, 3) In vivo examination and validation of the
epigenome/transcriptome regulation in mouse atherosclerosis models. W...

## Key facts

- **NIH application ID:** 10629289
- **Project number:** 5R01HL121365-11
- **Recipient organization:** UNIVERSITY OF SOUTHERN CALIFORNIA
- **Principal Investigator:** SHU CHIEN
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $583,656
- **Award type:** 5
- **Project period:** 2013-12-20 → 2026-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10629289

## Citation

> US National Institutes of Health, RePORTER application 10629289, Integration of single-cell imaging and multi-omics sequencing to study EC mechano-pathophysiology (5R01HL121365-11). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10629289. Licensed CC0.

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