# New approaches for understanding lipid movement in health and disease

> **NIH NIH P01** · UNIVERSITY OF CALIFORNIA LOS ANGELES · 2022 · $2,325,780

## Abstract

PPG Title: New Approaches for Understanding Lipid Movement in Health and Disease
SUMMARY/ABSTRACT
Our Program Project Grant (PPG) focuses on lipid metabolism and transport, with the goal of defining
mechanisms for metabolic and cardiovascular disease. Our PPG team has made seminal discoveries in lipid
metabolism and transport. We discovered an endothelial cell protein, GPIHBP1, that transports lipoprotein lipase
(LPL) to the capillary lumen and stabilizes the structure of LPL. Recently, we defined the structure of the
GPIHBP1–LPL complex, providing fresh insights into mutations causing hypertriglyceridemia and opening the
door to understanding mechanisms that regulate intravascular lipolysis. In the realm of cholesterol metabolism,
our PPG discovered that macrophages release, by plasma membrane (PM) budding, particles that are enriched
in cholesterol. Our PPG uncovered a link between inflammatory signaling and cholesterol metabolism in
macrophages, and we identified a new protein, Aster-B, that is critical for cholesterol movement between the PM
and the endoplasmic reticulum (ER). A deficiency of Aster-B impairs cholesterol movement to the ER, causing
a striking upregulation of lipid biosynthetic genes. These discoveries, all relevant to the pathogenesis of
atherosclerosis, were utterly dependent on collaborations between our PPG leaders and the advanced
molecular, biochemical, and imaging capabilities in their laboratories. As we look to the future, we will dig deeper
into the molecules and mechanisms that we have uncovered. In project 1, Drs. Young and his PPG colleagues
will use biochemical and biophysical tools to elucidate the functions of the LPL–GPIHBP1 complex, including the
role of GPIHBP1’s acidic domain in stabilizing LPL activity and capturing LPL within the subendothelial spaces.
They will also study, with electron microscopy and NanoSIMS imaging, the budding of cholesterol-rich particles
from the macrophage PM. They will define the composition of the particles and explore their relevance to reverse
cholesterol transport. In project 2, Dr. Bensinger and coworkers will determine how inflammatory signals
modulate the lipidome of macrophages. They will also define mechanisms by which alterations in cholesterol
homeostasis affect STING signaling and the impact of the STING pathway on dyslipidemia, inflammation, and
atherogenesis. In Project 3, Dr. Tontonoz and his PPG coworkers will explore the role of Aster-B in cholesterol
transport, efflux, and esterification and elucidate the function of Aster-B in sterol transport in vivo. They will also
assess the contribution of the “macrophage Aster pathway” to atherosclerosis and screen for additional proteins
required for the nonvesicular transport of cholesterol within cells. The three component projects will be supported
by a single scientific core, led by Dr. Loren Fong and colleagues. They will produce recombinant proteins, provide
advanced microscopy services, including NanoSIMS imaging of...

## Key facts

- **NIH application ID:** 10397409
- **Project number:** 5P01HL146358-04
- **Recipient organization:** UNIVERSITY OF CALIFORNIA LOS ANGELES
- **Principal Investigator:** Stephen G. Young
- **Activity code:** P01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $2,325,780
- **Award type:** 5
- **Project period:** 2019-05-01 → 2024-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10397409

## Citation

> US National Institutes of Health, RePORTER application 10397409, New approaches for understanding lipid movement in health and disease (5P01HL146358-04). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10397409. Licensed CC0.

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