Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P42345 (mTOR)
 26,049 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The mammalian target of rapamycin (mTOR) is a protein tyrosine kinase that regulates cell proliferation and survival via its effects on transcription, translation and autophagy. The activity of mTOR is controlled by a number of nutrient and energy sensing pathways, inhibiting cell proliferation under conditions of deprivation. In addition, mTOR has been associated with the inhibition of apoptosis and the clearance of toxic protein aggregates. Many neurodegenerative diseases are characterized by neuronal death via apoptosis, and it is possible that modulation of mTOR activity may offer some protection against their effects. In particular, diseases involving oxygen and nutrient deprivation, such as stroke, or diseases characterized by aggregate formation, such as Alzheimer's and Huntington's disease, could gain substantial benefit by either inhibiting or enhancing mTOR activity. In addition, inhibition of mTOR in cancerous tissue decreases cell proliferation and increases apoptosis, and is an effective therapy for brain tumors. In this article, the effects of mTOR and their potential usefulness for the treatment of neurological disease are examined.
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PMID:The mTOR pathway as a potential target for the development of therapies against neurological disease. 1808 36

Germinal matrix hemorrhage (GMH) is the most common neurological disease of premature newborns. GMH causes neurological sequelae such as cerebral palsy, post-hemorrhagic hydrocephalus, and mental retardation. Despite this, there is no standardized animal model of spontaneous GMH using newborn rats to depict the condition. We asked whether stereotactic injection of collagenase type VII (0.3 U) into the ganglionic eminence of neonatal rats would reproduce the acute brain injury, gliosis, hydrocephalus, periventricular leukomalacia, and attendant neurological consequences found in humans. To test this hypothesis, we used our neonatal rat model of collagenase-induced GMH in P7 pups, and found that the levels of free-radical adducts (nitrotyrosine and 4-hyroxynonenal), proliferation (mammalian target of rapamycin), inflammation (COX-2), blood components (hemoglobin and thrombin), and gliosis (vitronectin and GFAP) were higher in the forebrain of GMH pups, than in controls. Neurobehavioral testing showed that pups with GMH had developmental delay, and the juvenile animals had significant cognitive and motor disability, suggesting clinical relevance of the model. There was also evidence of white-matter reduction, ventricular dilation, and brain atrophy in the GMH animals. This study highlights an instructive animal model of the neurological consequences after germinal matrix hemorrhage, with evidence of brain injuries that can be used to evaluate strategies in the prevention and treatment of post-hemorrhagic complications.
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PMID:Rodent neonatal germinal matrix hemorrhage mimics the human brain injury, neurological consequences, and post-hemorrhagic hydrocephalus. 2252 90

The mTOR signaling pathway integrates inputs from a variety of upstream stimuli to regulate diverse cellular processes including proliferation, growth, survival, motility, autophagy, protein synthesis and metabolism. The mTOR pathway is dysregulated in a number of human pathologies including cancer, diabetes, obesity, autoimmune disorders, neurological disease and aging. Ongoing clinical trials testing mTOR-targeted treatments number in the hundreds and underscore its therapeutic potential. To date mTOR inhibitors are clinically approved to prevent organ rejection, to inhibit restenosis after angioplasty, and to treat several advanced cancers. In this review we discuss the continuously evolving field of mTOR pharmacogenomics, as well as highlight the emerging efforts in identifying diagnostic and prognostic markers, including miRNAs, in order to assess successful therapeutic responses.
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PMID:Tailoring mTOR-based therapy: molecular evidence and clinical challenges. 2402 1

The mammalian target of rapamycin (mTOR) assembles into two distinct multi-protein complexes called mTORC1 and mTORC2. While mTORC1 controls the signaling pathways important for cell growth, the physiological function of mTORC2 is only partially known. Here we comment on recent work on gene-targeted mice lacking mTORC2 in the cerebellum or the hippocampus that provided strong evidence that mTORC2 plays an important role in neuron morphology and synapse function. We discuss that this phenotype might be based on the perturbed regulation of the actin cytoskeleton and the lack of activation of several PKC isoforms. The fact that PKC isoforms and their targets have been implicated in neurological disease including spinocerebellar ataxia and that they have been shown to affect learning and memory, suggests that aberration of mTORC2 signaling might be involved in diseases of the brain.
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PMID:In vivo evidence for mTORC2-mediated actin cytoskeleton rearrangement in neurons. 2472 30

Mitochondria have a crucial role in the supply of energy to the brain. Mitochondrial alterations can lead to detrimental consequences on the function of brain cells and are thought to have a pivotal role in the pathogenesis of several neurologic disorders. This study was aimed to evaluate mitochondrial function, fusion-fission and biogenesis and autophagy in brain cortex of 6-month-old Goto-Kakizaki (GK) rats, an animal model of nonobese type 2 diabetes (T2D). No statistically significant alterations were observed in mitochondrial respiratory chain and oxidative phosphorylation system. A significant decrease in the protein levels of OPA1, a protein that facilitates mitochondrial fusion, was observed in brain cortex of GK rats. Furthermore, a significant decrease in the protein levels of LC3-II and a significant increase in protein levels of mTOR phosphorylated at serine residue 2448 were observed in GK rats suggesting a suppression of autophagy in diabetic brain cortex. No significant alterations were observed in the parameters related to mitochondrial biogenesis. Altogether, these results demonstrate that during the early stages of T2D, brain mitochondrial function is maintained in part due to a delicate balance between mitochondrial fusion-fission and biogenesis and autophagy. However, future studies are warranted to evaluate the role of mitochondrial quality control pathways in late stages of T2D.
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PMID:Mitochondrial quality control systems sustain brain mitochondrial bioenergetics in early stages of type 2 diabetes. 2483 64

Tau is a normal microtubule-associated protein; mutations to phosphorylated or acetylated forms are neurotoxic. In many dementias of adult life tauopathies cause neuronal degeneration. Four developmental disorders of the fetal and infant brain are presented, each of which exhibits up-regulation of tau. Microtubules are cytoskeletal structures that provide the strands of mitotic spindles and specify cellular polarity, growth, lineage, differentiation, migration and axonal transport of molecules. Phosphorylated tau is abnormal in immature as in mature neurons. Several malformations are demonstrated in which upregulated tau may be important in pathogenesis. All produce highly epileptogenic cortical foci. The prototype infantile tauopathy is (1) hemimegalencephaly (HME); normal tau is degraded by a mutant AKT3 or AKT1 gene as the aetiology of focal somatic mosaicism in the periventricular neuroepithelium. HME may be isolated or associated with neurocutaneous syndromes, particularly epidermal naevus syndromes, also due to somatic mutations. Other tauopathies of early life include: (2) tuberous sclerosis complex; (3) focal cortical dysplasia type 2b (FCD2b); and (4) ganglioglioma, a tumor with dysplastic neurons and neoplastic glial cells. Pathological tau in these infantile cases alters cellular growth and architecture, synaptic function and tissue organization, but does not cause neuronal loss. All infantile tauopathies are defined neuropathologically as a tetrad of (1) dysmorphic and megalocytic neurons; (2) activation of the mTOR signaling pathway; (3) post-zygotic somatic mosaicism; and (4) upregulation of phosphorylated tau. HME and FCD2b may be the same disorder with different timing of the somatic mutation in the mitotic cycles of the neuroepithelium. HME and FCD2b may be the same disorder with different timing of the somatic mutation in the mitotic cycles of the neuroepithelium. Tauopathies must be considered in infantile neurological disease and no longer restricted to adult dementias. The mTOR inhibitor everolimus, already demonstrated to be effective in TSC, also may be a potential treatment in other infantile tauopathies.
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PMID:Infantile tauopathies: Hemimegalencephaly; tuberous sclerosis complex; focal cortical dysplasia 2; ganglioglioma. 2545 14

Mammalian target of rapamycin (mTOR) is an evolutionarily conserved serine/threonine kinase that is a member of the phosphoinositide 3-kinase (PI3K)-related kinase (PIKK) family. mTOR forms two distinct complexes, mTORC1 and mTORC2. mTORC1 has emerged as a central regulator of cellular metabolism, cell proliferation, cellular differentiation, autophagy and immune response regulation. In contrast to mTORC1, mTORC2, which is not well understood, participates in cell survival and the regulation of actin and cytokeratin organization. In addition, mTORC1 has been implicated in many diseases, including cancer, metabolic diseases, neurological disease, genetic diseases and longevity/aging. One of the diseases resulting from dysfunction of mTORC1 is tuberous sclerosis complex (TSC), which reflects all the symptoms that arise in response to mTORC1 dysfunction. TSC is a multiple hamartomas syndrome with epilepsy, autism, mental retardation and hypopigmented macules that are caused by the constitutive activation of mTORC1 resulting from genetic mutation of TSC1 or TSC2. Inhibitors of mTORC1, such as rapamycin, effectively suppress the symptoms of TSC. This article summarizes the current knowledge on mTOR and the efficacy of mTORC1 inhibitors in the treatment of TSC.
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PMID:Mammalian target of rapamycin and tuberous sclerosis complex. 2605 78

Recent studies indicated that different caloric intake may influence neuronal function. Excessive caloric intake associated with accelerated aging of the brain and increased the risk of neurodegenerative disorders. And low caloric intake (caloric restriction, CR) could delay aging, and protect the central nervous system from neurodegenerative disorders. The underlying mechanisms remain poorly understood. In this study, thirty six-week-old male C57/BL male mice were randomly divided into three different dietary groups: normal control (NC) group (fed standard diet), CR group (fed low-caloric diet) and high-calorie (HC) group (fed high-caloric diet). After 10 months, spatial memory ability was determined by Morris water maze. Pathological changes of the hippocampus cells were detected with HE and Nissl staining. The expression of proteins involved in autophagy in the hippocampus was determined by immunofluorescence and Western blot. The result of Morris water maze showed that the learning and memory capacity significantly increased in the CR group, and significantly decreased in the HC group. HE and Nissl staining showed cells damaged obviously in the HC group. The expression of mTOR and p62 was increased in the HC group, and decreased in the CR group. The expression of Beclin1, LC3 and cathepsin B was decreased in the HC group, and increased in the CR group. Our findings demonstrate that long-term high caloric intake is a risk factor that can significantly contribute to the development of neurological disease via suppressing autophagy, and CR may prevent age-related learning ability impairment via activating autophagy in mice.
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PMID:Autophagy involving age-related cognitive behavior and hippocampus injury is modulated by different caloric intake in mice. 2638 26

Spinal cord injury (SCI) is a severe neurological disease with few efficacious drugs. Autophagy is a cellular process to confront with stress after SCI and considered to be a therapeutic target of SCI. In this study, we investigated the therapeutic effect of metformin on functional recovery after SCI and its underlying mechanism of autophagy regulation. Using a rat model of traumatic SCI, we found improved function recovery which was paralleled by a reduction of apoptosis after metformin treatment. We further examined autophagy via detecting autophagosomes by transmission electron microscopy and immunofluorescence, as well as autophagy markers by western blot in each groups. The results showed that the number of autophagosomes and expression of autophagy markers such as LC3 and beclin1 were increased in SCI group, while autophagy substrate protein p62 as well as ubiquitinated proteins were found to accumulate in SCI group, indicating an impaired autophagy flux in SCI. But, metformin treatment attenuated the accumulation of p62 and ubiquitinated proteins, suggesting a stimulative effect of autophagy flux by metformin. Blockage of autophagy flux by chloroquine partially abolished the apoptosis inhibition and functional recovery effect of metformin on SCI, which suggested that the protective effect of metformin on SCI was through autophagy flux stimulation. Activation of AMPK as well as inhibition of its downstream mTOR signaling were detected under metformin treatment in vivo and in vitro; inhibition of AMPK signaling by compound C suppressed autophagy flux induced by metformin in vitro, indicating that AMPK signaling was involved in the effect of metformin on autophagy flux regulation. Together, these results illustrated that metformin improved functional recovery effect through autophagy flux stimulation and implied metformin to be a potential drug for SCI therapy.
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PMID:Metformin Improves Functional Recovery After Spinal Cord Injury via Autophagy Flux Stimulation. 2716 28

Tuberous sclerosis complex (TSC) is an autosomal dominant and multi-system genetic disorder in humans. TSC affects around 25,000 to 40,000 individuals in the United States and about 1 to 2 million individuals worldwide, with an estimated prevalence of one in 6,000 newborns. TSC occurs in all races and ethnic groups, and in both genders. TSC is caused by defects or mutations in two genes, TSC1 and TSC2. Loss of TSC1/TSC2 leads to dysregulation of mTOR, resulting in aberrant cell differentiation and development, and abnormal enlargement of cells. TSC is characterized by the development of benign and/or malignant tumors in several organs including renal/liver angiomyolipomas, facial angiofibroma, lymphangiomyomatosis, cardiac rhabdomyomas, retinal astrocytic, renal cell carcinoma, and brain subependymal giant cell astrocytomas (SEGA). In addition, TSC disease causes disabling neurologic disorders, including epilepsy, mental retardation and autism. Particularly problematic are the development of renal angiomyolipomas, which tend to be larger, bilateral, multifocal and present at a younger age compared with sporadic forms. In addition, SEGA block the flow of fluid within the brain, causing a buildup of fluid and pressure that leads to blurred vision and seizures. In the current review, we describe the pathology of TSC disease in key organs and summarize the use of mTOR inhibitors to treat tumors in TSC patients.
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PMID:Is mTOR Inhibitor Good Enough for Treatment All Tumors in TSC Patients? 2769 99


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