# CRISPRa induced expression of native MRI reporter proteins

> **NIH NIH R21** · MICHIGAN STATE UNIVERSITY · 2022 · $189,241

## Abstract

Abstract: Genome editing technologies such as CRISPR-Cas encompass new therapeutic tools for treating and
curing a broad set of diseases ranging from cancer to genetic abnormalities to metabolic diseases, even
stretching as far as combating aging and regenerating tissue. Extending beyond permanent genome
modification, the expanding ensemble of CRISPR technologies based on engineered Cas proteins now possess
capabilities for programmable epigenetic regulation, transcriptional control of native genes, and RNA editing;
moreover, these systems can be combined for orthogonal control of gene expression. These technologies open
up unlimited therapeutic applications but the critical requirement that the targeted or transplanted cells be
monitored and tracked in vivo for verifying both intended and unintended consequences, is unmet.
 Here we propose a new paradigm in imaging reporters based on CRISPR-Cas, well suited for in vivo
imaging of cell and gene therapies. Rather than introduce exogenous imaging reporter genes into the genome
or cell, we hypothesize that cell and gene therapies can be imaged in vivo by using CRISPR-mediated
transcriptional activation (CRISPRa) technology to induce expression of native proteins that function as
imaging reporters. We call this paradigm CRISPRa-MRI. The benefits of CRISPRa-MRI are that these
proteins would be inherently human, would only be transiently expressed without disrupting the genome and
would enable multiplexing either with other reporter proteins or CRISPR therapeutics, simultaneously. As a proof-
of-concept, we will focus on the hepatic organic anion transporting polypeptides (OATPs) mouse OATP1A1
(mOATP1A1) and human OATP1B3 (hOATP1B3), recognizing that many other transporters, metal binding
proteins and cell surface receptors are also viable endogenous reporter candidates. mOATP1A1 and hOATP1B3
both specifically transport the FDA-approved MRI contrast agent Gd-EOB-DTPA into cells, the accumulation of
which results in robust bright MRI signal. Normally, expression of these transporters is limited to the liver, but by
using CRISPRa these silent imaging reporter genes can be ‘turned on’ and used to image any cell type or
lineage. CRISPRa-MRI can co-opt the technology used for CRISPR editing or therapeutics in the engineered
cells or gene therapy, avoiding the potential for insertional mutagenesis or chronic expression of an exogenous
gene which may lead to immunogenicity or toxicity, while at the same time eliminating the additional challenge
of delivery and expression of conventional reporter genes. Here we propose to develop a CRISPRa strategy for
activating endogenous mOATP1A1 and hOATP1B3 in vitro (Specific Aim 1) and then test its performance for
in vivo imaging of directly targeted tissues or CRISPRa induction in cells post-transplantation (Specific Aim 2).
 The promise of imaging reporter genes for cell and gene-based therapies in humans is, as yet, largely
unfulfilled. CRISPRa-MRI is a completely no...

## Key facts

- **NIH application ID:** 10482409
- **Project number:** 5R21EB032110-02
- **Recipient organization:** MICHIGAN STATE UNIVERSITY
- **Principal Investigator:** Erik Shapiro
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $189,241
- **Award type:** 5
- **Project period:** 2021-09-15 → 2023-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10482409

## Citation

> US National Institutes of Health, RePORTER application 10482409, CRISPRa induced expression of native MRI reporter proteins (5R21EB032110-02). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10482409. Licensed CC0.

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