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Disease
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Drug
Enzyme
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Pivot Concepts:
Gene/Protein
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Drug
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Target Concepts:
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Query: UNIPROT:P42345 (
mTOR
)
26,049
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Spinal Cord
Injury (SCI) results in severe sub-lesional muscle atrophy and fiber type transformation from slow oxidative to fast glycolytic, both contributing to functional deficits and maladaptive metabolic profiles. Therapeutic countermeasures have had limited success and muscle-related pathology remains a clinical priority.
mTOR
signaling is known to play a critical role in skeletal muscle growth and metabolism, and signal integration of anabolic and catabolic pathways. Recent studies show that the natural compound ursolic acid (UA) enhances
mTOR
signaling intermediates, independently inhibiting atrophy and inducing hypertrophy. Here, we examine the effects of UA treatment on sub-lesional muscle
mTOR
signaling, catabolic genes, and functional deficits following severe SCI in mice. We observe that UA treatment significantly attenuates SCI induced decreases in activated forms of
mTOR
, and signaling intermediates PI3K, AKT, and S6K, and the upregulation of catabolic genes including FOXO1, MAFbx, MURF-1, and PSMD11. In addition, UA treatment improves SCI induced deficits in body and sub-lesional muscle mass, as well as functional outcomes related to muscle function, motor coordination, and strength. These findings provide evidence that UA treatment may be a potential therapeutic strategy to improve muscle-specific pathological consequences of SCI.
...
PMID:Effects of ursolic acid on sub-lesional muscle pathology in a contusion model of spinal cord injury. 3015 45
Objective:
The study was aimed to investigate whether the neuroprotective role of curcumin is associated with regulation of autophagy.
Methods:
Rat spinal cord injury (SCI) models were established according to Allen's weight-drop trauma method. Curcumin was administered 30 min after the contusion and continued weekly. At 3, 7, 14, 21, and 28 days after SCI, functional recovery was evaluated using the Basso, Beattie and Bresnahan (BBB) scoring and the oblique plate test, following which, spinal cord tissues were obtained. Histological changes and apoptosis were then measured with H&E staining and TUNEL assay. Glia activation, inflammatory infiltration, inflammatory factor release, and myelination were observed through immunohistochemical (IHC) staining and ELISA. Autophagy and Akt activation were detected by western blotting. After autophagy was inhibited by injection of chloroquine, TUNEL, inflammatory factor release, myelin basic protein (MBP) IHC staining and functional recovery evaluation were performed again.
Results:
Curcumin treatment promoted functional recovery after SCI and reduced neuron apoptosis, improved spinal cord integrity, recovery, and re-myelination, and suppressed the inflammatory response. Autophagy was enhanced and Akt/
mTOR
pathway was inhibited by curcumin. Autophagy inhibition partially eliminated the protective effect of curcumin on SCI.
Conclusion:
Curcumin may exert its therapeutic effect on SCI through the enhancement of autophagy, in which, inhibition of the Akt/
mTOR
signaling pathway may be also involved.
J
Spinal Cord
Med 2019 Jun 04
PMID:Curcumin promotes functional recovery and inhibits neuronal apoptosis after spinal cord injury through the modulation of autophagy. 3116 84
Degenerative disc disease is a highly prevalent, global health problem that represents the primary cause of back pain and is associated with neurological disorders, including radiculopathy,
myelopathy
, and paralysis, resulting in worker disability and socioeconomic burdens. The intervertebral disc is the largest avascular organ in the body, and degeneration is suspected to be linked to nutritional deficiencies. Autophagy, the process through which cells self-digest and recycle damaged components, is an important cell survival mechanism under stress conditions, especially nutrient deprivation. Autophagy is negatively controlled by the
mammalian target of rapamycin
(
mTOR
) signaling pathway.
mTOR
is a serine/threonine kinase that detects nutrient availability to trigger the activation of cell growth and protein synthesis pathways. Thus, resident disc cells may utilize autophagy and
mTOR
signaling to cope with harsh low-nutrient conditions, such as low glucose, low oxygen, and low pH. We performed rabbit and human disc cell and tissue studies to elucidate the involvement and roles played by autophagy and
mTOR
signaling in the intervertebral disc. In vitro serum and nutrient deprivation studies resulted in decreased disc cell proliferation and metabolic activity and increased apoptosis and senescence, in addition to increased autophagy. The selective RNA interference-mediated and pharmacological inhibition of
mTOR
complex 1 (mTORC1) was protective against inflammation-induced disc cellular apoptosis, senescence, and extracellular matrix catabolism, through the induction of autophagy and the activation of the Akt-signaling network. Although temsirolimus, a rapamycin derivative with improved water solubility, was the most effective mTORC1 inhibitor tested, dual
mTOR
inhibitors, capable of blocking multiple
mTOR
complexes, did not rescue disc cells. In vivo, high levels of
mTOR
-signaling molecule expression and phosphorylation were observed in human intermediately degenerated discs and decreased with age. A mechanistic understanding of autophagy and
mTOR
signaling can provide a basis for the development of biological therapies to treat degenerative disc disease.
...
PMID:Autophagy and mTOR signaling during intervertebral disc aging and degeneration. 3221 93
Intervertebral disc degeneration is the primary cause of back pain and associated with neurological disorders including radiculopathy,
myelopathy
, and paralysis. The currently available surgical treatments predominantly include the excision of pathological discs, resulting in the function loss, immobilization, and potential additional complications due to the altered biomechanics. Gene therapy approach involves gene transfer into cells, affects RNA and protein synthesis of the encoded genes in the recipient cells, and facilitates biological treatment. Relatively long-exerting therapeutic effects by gene therapy are potentially advantageous to treat slow progressive degenerative disc disease. In gene therapy, the delivery method and selection of target gene(s) are essential. Although gene therapy was first mediated by viral vectors, technological progress has enabled to apply nonviral vectors and polyplex micelles for the disc. While RNA interference successfully provides specific downregulation of multiple genes in the disc, clustered regularly interspaced short palindromic repeats (CRISPR) system has increased attention to alter the process of intervertebral disc degeneration. Then, more recent findings of our studies have suggested autophagy, the intracellular self-digestion, and recycling system under the negative regulation by the
mammalian target of rapamycin
(
mTOR
), as a gene therapy target in the disc. Here we briefly review backgrounds and applications of gene therapy for the disc, introducing strategies of autophagy and
mTOR
signaling modulation through selective RNA interference.
...
PMID:Gene Therapy Approach for Intervertebral Disc Degeneration: An Update. 3225 49