# PIMT1 in Red Blood Cell aging in vivo and in vitro

> **NIH NIH R01** · UNIVERSITY OF COLORADO DENVER · 2020 · $605,807

## Abstract

ABSTRACT
A variety of specific chemical damage occurs as a result of normal cellular senescence, as well as accelerated
damage in the context of certain pathologies. One such chemical pathway is the degradation of aspartates into
isoaspartyl residues through oxidant damage. As a repair mechanisms, PIMT1 is an enzymatic pathway that
methylates isoaspartyl residues, creating an isoaspartyl methyl ester that is capable of then spontaneously
reverting into aspartate, thus reversing isoaspartyl damage. Insufficient PIMT1 activity has been associated with
increased oxidant stress and shorter cellular and organism lifespan in mice; however, a detailed metabolic and
biochemical analysis of the role of PIMT1 has not been elucidated. In this application, we propose to study the
role of PIMT1 in cellular aging. While multiple tissues will be analyzed to test general effects of PIMT1, this
proposal mainly focusses on a specific central hypothesis regarding effects in red blood cells (RBCs). RBCs are
essential to health, and dysfunction of RBCs plays a central role in multiple diseases. In addition, transfusion of
RBCs is the single most common inpatient invasive therapy, being given to approximately 1 out of every 70
Americans, annually. RBCs that are transfused are stored (as a logistical necessity) for up to 42 days, during
which time they undergo specific cellular and biochemical damage. RBCs are known to lose an essential
regulatory function through a key gene product (AE1) in normal cellular aging and in RBC storage. However, the
molecular mechanism by which AE1 dysfunction occurs has been unknown. In this application we provide novel
data demonstrating that isoaspartyl damage occurs in AE1 of both human and murine RBCs in a domain of AE1
that requires aspartates to function. We likewise present data suggesting that failure of PIMT1 pathways
accelerates this damage – however whole animal modeling with deletion of PIMT1 is required to test a
mechanistic role. In this context, we offer the following specific aims, designed to critically test hypotheses
around the role of PIMT1 mediated repair of oxidant damage. Specific Aim 1: Mechanistic elucidation of the
role of protein methylation by PIMT1 in the function and senescence of RBCs. Specific Aim 2: the interaction
of increased oxidant stress on PIMT1 and its effects on RBCs aging in vivo and ex vivo (blood storage). PIMT1
null mice will be combined with additional strains designed to isolate metabolic pathways of functional relevance
(e.g. G6PD deficient). Advanced experimental methodologies will be applied to these animals in order to isolate
cells of particular age and physiological conditions. Finally, the controlled biologies generated from these
approaches will be analyzed by cutting edge metabolomic and proteomic methodologies. In aggregate, these
studies will advance our understanding of the role of specific pathways of biochemical cellular aging, of the
mechanistic role of a conserved repair pathw...

## Key facts

- **NIH application ID:** 9983156
- **Project number:** 5R01HL146442-02
- **Recipient organization:** UNIVERSITY OF COLORADO DENVER
- **Principal Investigator:** Angelo D'Alessandro
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $605,807
- **Award type:** 5
- **Project period:** 2019-08-01 → 2024-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9983156

## Citation

> US National Institutes of Health, RePORTER application 9983156, PIMT1 in Red Blood Cell aging in vivo and in vitro (5R01HL146442-02). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9983156. Licensed CC0.

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