Exogenous L6 myotube mitochondrial transplantation attenuates hypertrophy and elicits a unique proteomic signature in phenylephrine-treated H9C2 cardiomyocytes
- 1Auburn University
Abstract
Mitochondrial transplantation has recently emerged as an alternative treatment for cardiovascular disease (CVD), aimed at increasing mitochondrial number and improving mitochondrial function. Though mitochondrial dysfunction is a key factor in the development of right ventricular hypertrophy/failure, the effects of mitochondrial transplantation on disease mitigation have been largely unexplored. Therefore, this in vitro study aimed to determine whether the transplantation of exogenous L6 myotube mitochondria mitigates negative outcomes in H9C2 cardiomyocytes that were stimulated to hypertrophy with phenylephrine. Control (CTL), control with mitochondrial transplantation (MitoTx), Phenylephrine only (Phe-only), and phenylephrine with mitochondrial transplantation (Phe+MitoTx) treatments were evaluated. Pilot experiments indicated mitochondrial transplantation into healthy cardiomyocytes acutely increased Complex I-linked oxidative phosphorylation (OXPHOS) capacity (p=0.005) and maximal respiratory capacity (p=0.022) within 24 hours, and these data alongside microscopic evidence of fluorescently labeled L6 mitochondria in H9C2 cardiomyocytes suggested successful transplantation. Regarding treatment comparisons, Phe-only showed a significant increase in cell area (p<0.05), while Phe+MitoTx blunted the hypertrophic cardiomyocyte response. Consistent with these results, proteomic analysis of 4,806 proteins showed that transplantation enriched the mitochondrial proteome, impacting pathways including OXPHOS, respiration, fatty acid and amino acid metabolism, while suppressing extracellular matrix remodeling and de-differentiation signatures. This response was observed in healthy and phenylephrine-stressed cardiomyocytes. In conclusion, our in vitro data indicates that transplantation of L6 skeletal muscle mitochondria mitigates negative effects induced by phenylephrine in H9C2 cardiomyocytes. However, more rigorous in vivo studies are needed to determine if this is a suitable approach for disease mitigation.
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BibTeX
@misc{kontos2026exogenous,
title = {{Exogenous L6 myotube mitochondrial transplantation attenuates hypertrophy and elicits a unique proteomic signature in phenylephrine-treated H9C2 cardiomyocytes}},
author = {N. J. Kontos and G. J. Kontos and D. T. Lewis and S. C. Norton and B. A. Ruple and A. N. Kavazis and D. T. Beck and M. D. Boersma and C. B. Mobley and D. J. McCullough and A. Ismaeel and M. D. Roberts},
howpublished = {bioRxiv},
year = {2026},
month = sep,
doi = {10.64898/2026.09.21.753229},
url = {https://www.biorxiv.org/content/10.64898/2026.09.21.753229v1},
note = {CC BY},
}
RIS
TY - UNPB
TI - Exogenous L6 myotube mitochondrial transplantation attenuates hypertrophy and elicits a unique proteomic signature in phenylephrine-treated H9C2 cardiomyocytes
AU - N. J. Kontos
AU - G. J. Kontos
AU - D. T. Lewis
AU - S. C. Norton
AU - B. A. Ruple
AU - A. N. Kavazis
AU - D. T. Beck
AU - M. D. Boersma
AU - C. B. Mobley
AU - D. J. McCullough
AU - A. Ismaeel
AU - M. D. Roberts
PY - 2026
DA - 2026/09/21
PB - bioRxiv
DO - 10.64898/2026.09.21.753229
UR - https://www.biorxiv.org/content/10.64898/2026.09.21.753229v1
AB - Mitochondrial transplantation has recently emerged as an alternative treatment for cardiovascular disease (CVD), aimed at increasing mitochondrial number and improving mitochondrial function. Though mitochondrial dysfunction is a key factor in the development of right ventricular hypertrophy/failure, the effects of mitochondrial transplantation on disease mitigation have been largely unexplored. Therefore, this in vitro study aimed to determine whether the transplantation of exogenous L6 myotube mitochondria mitigates negative outcomes in H9C2 cardiomyocytes that were stimulated to hypertrophy with phenylephrine. Control (CTL), control with mitochondrial transplantation (MitoTx), Phenylephrine only (Phe-only), and phenylephrine with mitochondrial transplantation (Phe+MitoTx) treatments were evaluated. Pilot experiments indicated mitochondrial transplantation into healthy cardiomyocytes acutely increased Complex I-linked oxidative phosphorylation (OXPHOS) capacity (p=0.005) and maximal respiratory capacity (p=0.022) within 24 hours, and these data alongside microscopic evidence of fluorescently labeled L6 mitochondria in H9C2 cardiomyocytes suggested successful transplantation. Regarding treatment comparisons, Phe-only showed a significant increase in cell area (p<0.05), while Phe+MitoTx blunted the hypertrophic cardiomyocyte response. Consistent with these results, proteomic analysis of 4,806 proteins showed that transplantation enriched the mitochondrial proteome, impacting pathways including OXPHOS, respiration, fatty acid and amino acid metabolism, while suppressing extracellular matrix remodeling and de-differentiation signatures. This response was observed in healthy and phenylephrine-stressed cardiomyocytes. In conclusion, our in vitro data indicates that transplantation of L6 skeletal muscle mitochondria mitigates negative effects induced by phenylephrine in H9C2 cardiomyocytes. However, more rigorous in vivo studies are needed to determine if this is a suitable approach for disease mitigation.
ER -