# Restriction of psoriatic skin and joint disease by A20

> **NIH NIH K08** · UNIVERSITY OF CALIFORNIA, SAN FRANCISCO · 2021 · $189,000

## Abstract

PROJECT SUMMARY: The relationship between psoriatic skin and joint disease remains enigmatic. A subset
of patients with psoriasis develop arthritis, early diagnosis of which is challenging. Additionally, therapies for
skin disease are less successful at treating arthritis. A20 (Tnfaip3) is a broadly-expressed protein that restricts
multiple inflammatory signaling pathways and is genetically associated with both psoriasis and psoriatic
arthritis in humans. However, the molecular and tissue-specific mechanisms by which A20 restricts psoriatic
disease are unknown. Our preliminary data shows that A20's capacity for binding linear ubiquitin is critical for
preventing distal digit psoriatic skin and joint disease in mice, with pathology requiring TNF, IL17A, and T-cells.
Early disease surrounded the epidermis; therefore, we generated mice allowing inducible deletion of A20 only
in keratinocytes in adulthood (A20iEKO mice). Remarkably, these mice also develop similar psoriatic skin and
joint disease that requires TNF, IL17A, and T-cells. I aim to determine the immune mechanisms by which A20
dysregulation in keratinocytes orchestrates skin and joint disease. Aim 1 centers around understanding the
cytokine requirements for coordinating the pathogenic immune infiltrate. In Aim 2 I will dissect the role of T-
cells by determining which subsets or antigen-specific cells are critical for pathogenic cytokine secretion as
well as their anatomical sites of action. Aim 3 focuses on the cell-intrinsic role of A20 in keratinocytes, where I
plan to understand the mechanisms by which A20 restricts inflammatory pathways in vivo, during keratinocyte
differentiation, and downstream TNFR and IL17R. Together, these studies will reveal how keratinocytes can
orchestrate an inflammatory process that results in psoriatic skin and joint disease. This is relevant to NIAMS
because these studies may help explain how human psoriasis is connected to psoriatic arthritis and may reveal
novel therapeutic targets or biomarkers for early or potential arthritic disease.
 My long-term goal is to establish an independent research program studying how inflammation remains
localized within epithelial tissues such as the skin. The studies described above will provide an outstanding
starting point as they aim to understand how skin dysregulation can cause joint inflammation. My research
background is primarily in cellular signaling and protein biochemistry. My career development aims are to build
my intellectual and scientific foundation in cellular immunology and develop professional relationships with
rheumatology-focused researchers. I also plan on developing key research skills in epithelial biology as well as
transcriptomic and statistical analysis. These development goals will be pursued with didactic courses along
with participation in seminar series, workshops, and conferences. Together with mentorship from Dr. Averil Ma,
a leading molecular immunologist, and guidance from a multidisci...

## Key facts

- **NIH application ID:** 10125868
- **Project number:** 1K08AR077065-01A1
- **Recipient organization:** UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
- **Principal Investigator:** Bahram Razani
- **Activity code:** K08 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $189,000
- **Award type:** 1
- **Project period:** 2021-02-05 → 2025-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10125868

## Citation

> US National Institutes of Health, RePORTER application 10125868, Restriction of psoriatic skin and joint disease by A20 (1K08AR077065-01A1). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10125868. Licensed CC0.

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