# Tafazzin and metabolic reprogramming during cardiomyopathy

> **NIH NIH R01** · INDIANA UNIVERSITY INDIANAPOLIS · 2021 · $578,683

## Abstract

PROJECT SUMMARY / ABSTRACT
 Barth syndrome (BTHS) is a genetic disorder due to mutations in the X-linked tafazzin (TAZ) gene
encoding an enzyme required for the functioning of mitochondria, the energy powerhouses of our cells. Patients
with inherited TAZ mutations suffer from a wide range of clinical manifestations, from neutropenia to severe left
ventricular noncompaction cardiomyopathy and skeletal muscle weakness. Other mitochondrial diseases
produce similar but not identical symptoms, possibly reflecting distinct types of mitochondrial impairment in
different tissues. Thus, understanding of molecular pathogenesis of BTHS and other mitochondriopathies is
highly significant for the health of the general public. However, it is not mechanistically clear how and why faulty
TAZ function produces impairment of largely the male heart, immune and musculoskeletal systems.
Furthermore, the establishment of proper mouse models of BTHS, as in other human genetic diseases, is
imperative to study BTHS in vivo and test potential therapies. Although the work of others has shown an
important role for tafazzin in the heart, this has necessitated the use of alternative mouse models, including
inducible shRNA Taz knockdown and “mixed Taz chimeras”, that are unable to mirror BTHS pathogenesis nor
phenocopy its progressive clinical manifestations. In preliminary studies, we overcame this crucial limitation of
in vivo BTHS syndrome research by editing a BTHS patient’s TAZ mutation into the orthologous conserved
residue of murine Taz gene by CRISPR/CAS technology. Preliminary data show our novel patient-specific Taz
point mutant male mice (TazPM that express mutant Taz at normal levels) display all key indicators of BTHS, from
impaired granulopoiesis to lethal fetal and postnatal non-compaction cardiomyopathy and impaired cardiolipin
biosynthesis. In order test which lineages are primarily affected, we generated a cardiomyocyte-restricted floxed
(TazcKO) mutant that develops postnatal cardiomyopathy with mitochondria and cardiolipin defects. We will test
our hypothesis that lack of cardiolipin and mitochondrial immaturity impedes in utero trabeculation whilst loss of
Taz catalytic activity dictates the timing and severity of postnatal hypoglycemic heart pathology, glycolytic
reprogramming and survival. Therefore, we are actively pursuing multidisciplinary pre- and postnatal longitudinal
cardiovascular phenotyping and metabolic testing of these unique mouse models to understand the in vivo
course of disease in comparison to humans, and testing whether TAFAZZIN replacement therapy and in vivo
pharmacological amelioration can mitigate the life-threatening BTHS birth defects in our patient-specific mouse
model. Together, this precision medicine-based proposal will provide mechanistic insights into the molecular
pathogenesis of the various cardiomyopathies resulting from TAZ disruption, unravel novel leads for evidence-
driven candidate therapies and help create patient-s...

## Key facts

- **NIH application ID:** 10280339
- **Project number:** 1R01HL159436-01
- **Recipient organization:** INDIANA UNIVERSITY INDIANAPOLIS
- **Principal Investigator:** Simon James Conway
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $578,683
- **Award type:** 1
- **Project period:** 2021-09-01 → 2025-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10280339

## Citation

> US National Institutes of Health, RePORTER application 10280339, Tafazzin and metabolic reprogramming during cardiomyopathy (1R01HL159436-01). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10280339. Licensed CC0.

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