# Endothelial laminin in blood brain barrier regulation

> **NIH NIH R01** · UNIVERSITY OF SOUTH FLORIDA · 2022 · $373,750

## Abstract

Project Summary/Abstract
The long-term objective of this application is to fully understand the biology of endothelial laminin in
cerebrovascular development and function in physiological conditions. This is in line with NHLBI’s
overarching objective to understand normal biological function. This proposal aims to investigate the
biological function of endothelial laminin in blood brain barrier (BBB) integrity under homeostatic
conditions, and explore its underlying molecular mechanism. In Aim 1, whether loss of endothelial
laminin affects BBB formation in early development or BBB maintenance at later stage will be
investigated using an innovative endothelial laminin knockout mouse line (EKO) generated in our
laboratory. The extent of BBB disruption will be determined using fluorescent tracers of various
molecular weights. Next, the underlying molecular mechanism (paracellular and/or transcellular
transport) will be explored at biochemical, ultrastructural, and functional levels both in vitro and in vivo.
Since hematopoietic cell-derived laminin is also ablated in these mutants, we will further investigate if
BBB breakdown in EKO mice is due to loss of laminin in endothelial cells or hematopoietic cells using
the VE-Cadherin-CreERT line. In Aim 2, the hypothesis that endothelial laminin regulates BBB integrity
via adenylyl cyclase-2 (AC2) will be tested. First, whether and how exactly endothelial laminin regulates
AC2 expression in brain microvascular endothelial cells will be examined in vitro and in vivo. Next, the
function of AC2 in BBB permeability and paracellular/transcellular transport will be investigated using
both loss-of-function and gain-of-function approaches. Third, whether the effect of AC2 on BBB integrity
relies on its adenylyl cyclase activity (generation of cAMP) will be investigated using AC2 inhibitors
and/or activators. If the answer is yes, which cAMP-downstream effector/signaling pathway (PKA
versus Epac) mediates AC2’s BBB-regulating function will be explored using PKA- and/or Epac-specific
inhibitors and activators. Successful completion of this proposal will elucidate the biological function of
endothelial laminin in BBB integrity and its underlying molecular mechanism; uncover a previously
unrecognized role of AC2 in transcellular transport (transcytosis); and identify endothelial laminin and
AC2 as novel molecular targets in BBB regulation, which will promote the development of innovative
treatments for BBB disruption. In addition, this proposal will also generate innovative research materials
(e.g. transgenic mouse line and lentiviral constructs) useful in the field of laminin/basement membrane,
which is understudied due to its intrinsic complexity and lack of research tools.

## Key facts

- **NIH application ID:** 10558332
- **Project number:** 7R01HL146574-04
- **Recipient organization:** UNIVERSITY OF SOUTH FLORIDA
- **Principal Investigator:** Yao Yao
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $373,750
- **Award type:** 7
- **Project period:** 2019-07-01 → 2024-02-29

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10558332

## Citation

> US National Institutes of Health, RePORTER application 10558332, Endothelial laminin in blood brain barrier regulation (7R01HL146574-04). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10558332. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*