# Identification and characterization of common, noncoding regulatory variants associated with Major Depressive Disorder.

> **NIH NIH F30** · WASHINGTON UNIVERSITY · 2020 · $50,520

## Abstract

Project Summary.
Major depressive disorder (MDD) is among the most common psychiatric illnesses in the United States and
worldwide, contributing significantly to the morbidity and lost quality of life attributable to mental illness. In spite
of personal and societal impacts of MDD, little progress has been made with regards to its cellular and brain-
wide etiology or pathogenesis—except, notably, replicable findings of lost hippocampal volume in patients.
This paucity of scientific information leaves additional questions as to why females experience MDD twice as
often. MDD-associated genetic regions recently identified in genome-wide association studies (GWAS) are a
first step toward identifying candidate genes and regulators underlying MDD and its sex differential incidence.
However, regions identified in GWAS, including those of MDD, generally contain tens or hundreds of single-
nucleotide variants in linkage, the vast majority being noncoding and regulatory in nature. Thus, attributing
biological function to a disease-associated GWAS region requires experimental identification of functional—
that is, gene-expression-altering—SNPs. Moreover, identifying functional SNPs requires study in disease
relevant cell-types, as regulatory elements behave in cell-type specific manners. A recent MDD GWAS
identified over a dozen loci, including ones near the genes Slc6a15 and Lin28b, which have existing biological
evidence to support their role in MDD. SNPs near Slc6a15 have been attributed to sex differential volume
changes in hippocampus in MDD patients, and Lin28b has been implicated by dysregulation of its targets, let-7
miRNAs, in depression patients, mouse models; Lin28b is also implicated in hippocampal neurodegeneration.
Therefore, this project seeks to thoroughly characterize sequences regulating these two genes, including sex-
specific regulators, and further seeks to identify functional SNPs from these two human GWAS loci. Using
massively-parallel reporter assays (MPRA), short 140bp regions of genomic sequences are paired to unique
9bp barcodes and a reporter gene. Transfection of the entire library of custom sequences, followed by RNA
sequencing, allows quantification of transcribed barcodes, each of which defines a specific 140bp sequence.
This allows for quantitative comparison of gene expression, including between sexes for the same sequence
and between SNP alleles. To study regulation of Slc6a15 and Lin28b, these experiments will be performed in
mouse neurospheres (for mouse genomic sequences near the two genes) and human neural progenitor cells
(for human genomic regions containing the linked SNPs). To assay these elements in a mature CNS context,
we also will deliver these MPRA libraries in vivo to the mouse brain, and selectively retrieve neuronal mRNAs
(i.e., including barcoded reporter RNAs) from the hippocampus using translating ribosome affinity purification
(TRAP). Ultimately, these findings will begin to unravel sex-differential gen...

## Key facts

- **NIH application ID:** 9941130
- **Project number:** 5F30MH116654-03
- **Recipient organization:** WASHINGTON UNIVERSITY
- **Principal Investigator:** Bernard John Mulvey
- **Activity code:** F30 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $50,520
- **Award type:** 5
- **Project period:** 2018-07-01 → 2021-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9941130

## Citation

> US National Institutes of Health, RePORTER application 9941130, Identification and characterization of common, noncoding regulatory variants associated with Major Depressive Disorder. (5F30MH116654-03). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/9941130. Licensed CC0.

---

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