Esther E. Dupont-Versteegden

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Muscles of spinal cord-transected rats exhibit severe atrophy and a shift toward a faster phenotype. Exercise can partially prevent these changes. The goal of this study was to investigate early events involved in regulating the muscle response to spinal transection and passive hindlimb exercise. Adult female Sprague-Dawley rats were anesthetized, and a(More)
Muscle atrophy is associated with a loss of muscle fiber nuclei, most likely through apoptosis. We investigated age-related differences in the extent of apoptosis in soleus muscle of young (6 mo) and old (32 mo) male Fischer 344 x Brown Norway rats subjected to acute disuse atrophy induced by 14 days of hindlimb suspension (HS). HS-induced atrophy(More)
Muscle atrophy with aging or disuse is associated with deregulated iron homeostasis and increased oxidative stress likely inflicting damage to nucleic acids. Therefore, we investigated RNA and DNA oxidation, and iron homeostasis in gastrocnemius muscles. Disuse atrophy was induced in 6- and 32-month old male Fischer 344/Brown Norway rats by 14 days of hind(More)
Cycling exercise attenuates atrophy in hindlimb muscles and causes changes in spinal cord properties after spinal cord injury in rats. We hypothesized that exercising soleus muscle expresses genes that are potentially beneficial to the injured spinal cord. Rats underwent spinal cord injury at T10 and were exercised on a motor-driven bicycle. Soleus muscle(More)
Disuse has been shown to cause a rapid and dramatic loss of skeletal mass and strength in the load-bearing bones of young and mature animals and humans. However, little is known about the skeletal effects of disuse in aged mammals. The present study was designed to determine whether the skeletal effects of disuse are maintained with extreme age. Fischer(More)
The loss of muscle mass with aging, or sarcopenia, is an important contributor to the functional decline and loss of independence observed with aging. Little is known about the role of apoptosis in sarcopenia. Studies in adult animals have shown that apoptosis is involved in the loss of muscle nuclei during acute disuse atrophy, and caspase-3 dependent(More)
In this study, possible mechanisms underlying soleus muscle atrophy after spinal cord transection and attenuation of atrophy with cycling exercise were studied. Adult female Sprague-Dawley rats were divided into three groups; in two groups the spinal cord was transected by a lesion at T10. One group was transected and killed 10 days later, and another group(More)
Changes in the structure and function of aging non-locomotor muscles remains understudied, despite their importance for daily living. Extraocular muscles (EOMs) have a high incidence of age-related mitochondrial defects possibly because of the metabolic stress resulting from their fast and constant activity. Apoptosis and autophagy (type I and II cell(More)
MicroRNAs (miRNAs) play critical roles in diverse cellular events through their effects on translation. Emerging data suggest that modulation of miRNA biogenesis at post-transcriptional steps by RNA-binding proteins is a key point of regulatory control over the expression of some miRNAs and the cellular processes they influence. However, the extent and(More)
The potential of two interventions, alone or in combination, to restore chronic spinal cord transection-induced changes in skeletal muscles of adult Sprague-Dawley rats was studied. Hind limb skeletal muscles were examined in the following groups of animals: rats with a complete spinal cord transection (Tx) for 8 weeks; Tx with a 4-week delay before(More)