# Dissecting the transcriptional mechanisms that govern melanocyte stem cell activation

> **NIH NIH F31** · ROCKEFELLER UNIVERSITY · 2020 · $42,257

## Abstract

Project Summary
 Adult tissues possess long-lived stem cells (SCs) that are responsible for maintaining and repairing
their lineage. Melanocyte stem cells (McSCs) are unique adult SCs located in hair follicles that maintain the
population of differentiated, pigment-producing melanocytes. To function properly, the balance between SC
quiescence, activation, and differentiation must be tightly regulated, and McSCs cycle between these states in
sync with the hair cycle. Understanding how McSCs transition from quiescence to activation and eventual
differentiation may provide insight that could be used to develop new treatments for melanocyte-related
pathologies. These include conditions such as the autoimmune pigmentation disorder vitiligo, where
stimulating quiescent McSCs with ultraviolet radiation has been shown to restore pigment-producing progeny
to the skin. Additionally, with increasing evidence suggesting that cancers hijack fundamental SC
mechanisms, this information will be important for understanding and treating melanoma. Therefore, the
objective of my proposed study is to elucidate the gene expression programs that drive McSC quiescence and
differentiation using comparative transcriptional profiling and functional testing in vivo. My preliminary data
indicate that there is significant differential gene expression between quiescent McSCs and their differentiated
progeny, many of which are transcription factors (TFs) with no known role in McSC biology. My central
hypothesis is that distinct transcriptional programs fueled by specific TFs are responsible for
maintaining quiescence and activation/differentiation of McSCs. In this study, I will 1) mechanistically
define the TF genes that promote McSC quiescence, and 2) interrogate key genes of the mature melanocyte
signature for their role in driving activation/differentiation. Using bioinformatics and pathways analysis, I have
selected TF candidates that I hypothesize are key regulators of each process. To start, I will map the temporal
expression patterns of each factor in their native microenvironment using in situ hybridization and
immunofluorescence staining of back skin throughout hair cycling. TFs will then be manipulated in vitro to
identify the most promising candidates for in vivo testing. For this purpose, I have developed an approach
combining CRISPR/Cas9 technology with our lab's well-established in utero lentiviral delivery system.
Lentivirus containing sgRNA will be used to transduce the neural crest (from which McSCs and melanocytes
arise) of embryos with lineage-specific and inducible TyrCreERT2-dependent Cas9 expression. Tamoxifen will
be administered postnatally to activate Cre, turn on Cas9, and knockout my candidate. After ablating these
TFs, I will assess the phenotypic consequences on McSC quiescence and activation/differentiation and
perform mechanistic studies to elucidate the cohorts of genes that they regulate. Understanding how McSCs
coordinate these cellular states...

## Key facts

- **NIH application ID:** 9972872
- **Project number:** 5F31AR073110-03
- **Recipient organization:** ROCKEFELLER UNIVERSITY
- **Principal Investigator:** Nicole Rai Infarinato
- **Activity code:** F31 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $42,257
- **Award type:** 5
- **Project period:** 2018-08-01 → 2021-06-14

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9972872

## Citation

> US National Institutes of Health, RePORTER application 9972872, Dissecting the transcriptional mechanisms that govern melanocyte stem cell activation (5F31AR073110-03). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9972872. Licensed CC0.

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