# Ascorbate protects brain after TBI by epigenetic modulation of 5-hydroxymethylation

> **NIH VA I01** · WM S. MIDDLETON MEMORIAL VETERANS HOSP · 2024 · —

## Abstract

Traumatic brain injury (TBI) is one of the leading causes of death and disability in adult humans including
service personnel and veterans. TBI promotes significant motor, cognitive and neuropsychiatric dysfunction.
The effects of TBI in surviving veterans can often be seen for decades after the initial injury. However, there
is no efficacious therapy to prevent post-TBI secondary brain damage and neurologic deficits.
Vitamin C (ascorbate) is highly concentrated in brain and known to promote neuroprotection after acute and
chronic CNS insults. However, its efficacy in TBI was not yet tested comprehensively. In preliminary studies,
we observed that ascorbate treatment reduces secondary brain damage and promotes better motor and
cognitive functional outcome in adult mice subjected to controlled cortical impact (CCI)- induced TBI. Based
on this, we will test the hypothesis “ascorbate treatment is neuroprotective after TBI.”
Epigenetic changes are known to significantly influence the gene expression and outcome after many
diseases. Of particular interest, cytosine in DNA undergoes methylation to form 5-methylcytosine (5mC) which
is a transcriptional silencer. 5mC will be oxidized by TET hydroxylases to form 5- hydroxymethylcytosine
(5hmC) which is a transcriptional derepression mark that increases cell survival under adverse conditions. In
particular, brain contains ~10 fold higher 5hmC levels than other organs of the body. Preliminary studies
showed that that ascorbate treatment enhances cerebral TET activity and 5hmC levels after TBI. Hence, we
further hypothesize that “the mechanism of ascorbate-induced neuroprotection after TBI is by the epigenetic
modulation of 5hmC.”
Aim 1: To test the neuroprotective potential of ascorbate after TBI. For any drug to be translated
clinically after TBI, robust preclinical testing that includes, but not limited to, a window of therapeutic
opportunity, long-term outcomes, efficacy in both sexes using a mouse CCI injury model that is rigorously
established in our lab.
Aim 2: To evaluate if DNA hydroxymethylation is mechanistically responsible for ascorbate
neuroprotection after TBI. Understanding the mechanisms of a drug actions help fine tune the therapy as
needed. Based on established work and preliminary data, we will test the functional significance of 5hmC in
post-TBI pathophysiology by knockdown of TET/5hmC together with ascorbate treatment. Genomic sites
where 5hmC is increased by ascorbate treatment after TBI will be mapped by hMeDIP- seq following TET
knockdown. This profiling will show the ascorbate-induced (TET-dependent) gene expression that helps to
understand the downstream effects of ascorbate protection. We will then analyze the effect of ascorbate
therapy on post-TBI gene expression (RNA-seq) in both male and female mice.
Overall, the present project will help us to identify if ascorbate minimizes secondary brain damage and
neurologic dysfunction after TBI by modulating the neuroprotective epigenet...

## Key facts

- **NIH application ID:** 10701140
- **Project number:** 1I01BX006062-01A1
- **Recipient organization:** WM S. MIDDLETON MEMORIAL VETERANS HOSP
- **Principal Investigator:** Raghu VEMUGANTI
- **Activity code:** I01 (R01, R21, SBIR, etc.)
- **Funding institute:** VA
- **Fiscal year:** 2024
- **Award amount:** —
- **Award type:** 1
- **Project period:** 2024-01-01 → 2028-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10701140

## Citation

> US National Institutes of Health, RePORTER application 10701140, Ascorbate protects brain after TBI by epigenetic modulation of 5-hydroxymethylation (1I01BX006062-01A1). Retrieved via AI Analytics 2026-06-02 from https://api.ai-analytics.org/grant/nih/10701140. Licensed CC0.

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