Spermidine supplementation influences mitochondrial number and morphology in the heart of aged mice

© 2021 The Authors. Journal of Anatomy published by John Wiley & Sons Ltd on behalf of Anatomical Society..

Aging is associated with cardiac hypertrophy and progressive decline in heart function. One of the hallmarks of cellular aging is the dysfunction of mitochondria. These organelles occupy around 1/4 to 1/3 of the cardiomyocyte volume. During cardiac aging, the removal of defective or dysfunctional mitochondria by mitophagy as well as the dynamic equilibrium between mitochondrial fusion and fission is distorted. Here, we hypothesized that these changes affect the number of mitochondria and alter their three-dimensional (3D) characteristics in aged mouse hearts. The polyamine spermidine stimulates both mitophagy and mitochondrial biogenesis, and these are associated with improved cardiac function and prolonged lifespan. Therefore, we speculated that oral spermidine administration normalizes the number of mitochondria and their 3D morphology in aged myocardium. Young (4-months old) and old (24-months old) mice, treated or not treated with spermidine, were used in this study (n = 10 each). The number of mitochondria in the left ventricles was estimated by design-based stereology using the Euler-Poincaré characteristic based on a disector at the transmission electron microscopic level. The 3D morphology of mitochondria was investigated by 3D reconstruction (using manual contour drawing) from electron microscopic z-stacks obtained by focused ion beam scanning electron microscopy. The volume of the left ventricle and cardiomyocytes were significantly increased in aged mice with or without spermidine treatment. Although the number of mitochondria was similar in young and old control mice, it was significantly increased in aged mice treated with spermidine. The interfibrillar mitochondria from old mice exhibited a lower degree of organization and a greater variation in shape and size compared to young animals. The mitochondrial alignment along the myofibrils in the spermidine-treated mice appeared more regular than in control aged mice, however, old mitochondria from animals fed spermidine also showed a greater diversity of shape and size than young mitochondria. In conclusion, mitochondria of the aged mouse left ventricle exhibited changes in number and 3D ultrastructure that is likely the structural correlate of dysfunctional mitochondrial dynamics. Spermidine treatment reduced, at least in part, these morphological changes, indicating a beneficial effect on cardiac mitochondrial alterations associated with aging.

Medienart:

E-Artikel

Erscheinungsjahr:

2023

Erschienen:

2023

Enthalten in:

Zur Gesamtaufnahme - volume:242

Enthalten in:

Journal of anatomy - 242(2023), 1 vom: 16. Jan., Seite 91-101

Sprache:

Englisch

Beteiligte Personen:

Messerer, Jil [VerfasserIn]
Wrede, Christoph [VerfasserIn]
Schipke, Julia [VerfasserIn]
Brandenberger, Christina [VerfasserIn]
Abdellatif, Mahmoud [VerfasserIn]
Eisenberg, Tobias [VerfasserIn]
Madeo, Frank [VerfasserIn]
Sedej, Simon [VerfasserIn]
Mühlfeld, Christian [VerfasserIn]

Links:

Volltext

Themen:

Aging
Focused ion beam scanning electron microscopy
Journal Article
Mitochondria
Research Support, Non-U.S. Gov't
Spermidine
Stereology
U87FK77H25

Anmerkungen:

Date Completed 23.12.2022

Date Revised 21.02.2023

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1111/joa.13618

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM334943477