# Neurosteroid Inhibition of Pyroptotic Lysis

> **NIH NIH R21** · UNIVERSITY OF WASHINGTON · 2020 · $194,375

## Abstract

Project Summary
Pyroptosis is a program of cell death involved in the pathogenesis of leading global causes of mortality.
Caspase-1 family proteases initiate pyroptosis by releasing the pore-forming portion of gasdermin D, which
inserts into the plasma membrane leading to cell lysis. Cellular factors released during pyroptotic lysis cause
local and systemic pathology, but processes regulating gasdermin D pore formation and lysis are not well
understood. We recently identified the neurosteroid pregnenolone sulfate as a novel inhibitor of pyroptotic
lysis, but its mechanism of action is not yet known. Neurosteroids including pregnenolone sulfate have a
lipophilic backbone and interact with plasma membrane proteins and lipids, suggesting the hypothesis that
these molecules may disrupt formation of gasdermin D pores. This proposal aims to understand how
pregnenolone sulfate prevents pyroptotic lysis and determine whether other steroids share this activity.
Our preliminary data demonstrate that pregnenolone sulfate prevents lysis during pyroptosis without affecting
upstream activation of inflammasomes or caspase-1. The experiments outlined in this proposal will test the
hypothesis that pregnenolone sulfate affects pore formation during pyroptosis and assess gasdermin D
cleavage, plasma membrane localization and oligomerization. We will also address the alternative hypotheses
that pregnenolone sulfate may regulate cell volume to prevent lysis or potentiate membrane repair processes.
Together, the results of these experiments will inform a precise molecular understanding of the mechanism of
action and reveal a novel strategy to disrupt pyroptotic lysis.
The steroid backbone is shared by a large number of molecules, each with specific biological activities. Our
preliminary data suggest that there may be molecular determinants for steroid inhibition of pyroptotic lysis, as a
related steroid demonstrates reduced potency. We will test a rationally selected library of structurally distinct
steroids for the ability to prevent pyroptotic lysis. These experiments will determine whether endogenous
steroids demonstrate potency consistent with potential physiologic relevance. In addition, these results will
identify the structure-activity relationship for inhibition of pyroptotic lysis to facilitate development of potent and
specific molecules and define a new paradigm for disease intervention.

## Key facts

- **NIH application ID:** 10037720
- **Project number:** 1R21AI153487-01
- **Recipient organization:** UNIVERSITY OF WASHINGTON
- **Principal Investigator:** Susan Leilani Fink
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $194,375
- **Award type:** 1
- **Project period:** 2020-05-25 → 2022-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10037720

## Citation

> US National Institutes of Health, RePORTER application 10037720, Neurosteroid Inhibition of Pyroptotic Lysis (1R21AI153487-01). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10037720. Licensed CC0.

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