Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0004352 (autism)
 32,579 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tuberous sclerosis (TSC) is a hamartoma syndrome attributable to mutations in either TSC1 or TSC2 in which brain involvement causes epilepsy, mental retardation, and autism. We have reported recently (Meikle et al., 2007) a mouse neuronal model of TSC in which Tsc1 is ablated in most neurons during cortical development. We have tested rapamycin and RAD001 [40-O-(2-hydroxyethyl)-rapamycin], both mammalian target of rapamycin mTORC1 inhibitors, as potential therapeutic agents in this model. Median survival is improved from 33 d to more than 100 d; behavior, phenotype, and weight gain are all also markedly improved. There is brain penetration of both drugs, with accumulation over time with repetitive treatment, and effective reduction of levels of phospho-S6, a downstream target of mTORC1. In addition, there is restoration of phospho-Akt and phospho-glycogen synthase kinase 3 levels in the treated mice, consistent with restoration of Akt function. Neurofilament abnormalities, myelination, and cell enlargement are all improved by the treatment. However, dysplastic neuronal features persist, and there are only modest changes in dendritic spine density and length. Strikingly, mice treated with rapamycin or RAD001 for 23 d only (postnatal days 7-30) displayed a persistent improvement in phenotype, with median survival of 78 d. In summary, rapamycin/RAD001 are highly effective therapies for this neuronal model of TSC, with benefit apparently attributable to effects on mTORC1 and Akt signaling and, consequently, cell size and myelination. Although caution is appropriate, the results suggest the possibility that rapamycin/RAD001 may have benefit in the treatment of TSC brain disease, including infantile spasms.
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PMID:Response of a neuronal model of tuberous sclerosis to mammalian target of rapamycin (mTOR) inhibitors: effects on mTORC1 and Akt signaling lead to improved survival and function. 1912 12

Tuberous sclerosis is a single-gene disorder caused by heterozygous mutations in the TSC1 (9q34) or TSC2 (16p13.3) gene and is frequently associated with mental retardation, autism and epilepsy. Even individuals with tuberous sclerosis and a normal intelligence quotient (approximately 50%) are commonly affected with specific neuropsychological problems, including long-term and working memory deficits. Here we report that mice with a heterozygous, inactivating mutation in the Tsc2 gene (Tsc2(+/-) mice) show deficits in learning and memory. Cognitive deficits in Tsc2(+/-) mice emerged in the absence of neuropathology and seizures, demonstrating that other disease mechanisms are involved. We show that hyperactive hippocampal mammalian target of rapamycin (mTOR) signaling led to abnormal long-term potentiation in the CA1 region of the hippocampus and consequently to deficits in hippocampal-dependent learning. These deficits included impairments in two spatial learning tasks and in contextual discrimination. Notably, we show that a brief treatment with the mTOR inhibitor rapamycin in adult mice rescues not only the synaptic plasticity, but also the behavioral deficits in this animal model of tuberous sclerosis. The results presented here reveal a biological basis for some of the cognitive deficits associated with tuberous sclerosis, and they show that treatment with mTOR antagonists ameliorates cognitive dysfunction in a mouse model of this disorder.
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PMID:Reversal of learning deficits in a Tsc2+/- mouse model of tuberous sclerosis. 1856 33

Behavioral problems are common in children with tuberous sclerosis complex (TSC) and can be challenging to manage at home. Standardized measures were used to assess behavior in 99 pediatric patients with TSC and to evaluate parenting stress in their parents. About 40% of the pediatric patients presented clinically significant behavioral problems, most frequently involving symptoms of autism spectrum disorder, inattention, and hyperactivity. Higher seizure frequency, mixed seizure disorder, and low intellectual functioning placed the patient at significant risk for behavior problems. Almost 50% of participating parents reported experiencing clinically significant parenting stress, which was associated with specific characteristics of the child, including the presence of current seizures, a history of psychiatric diagnosis, low intelligence, and behavioral problems. Clinicians should be aware that behavioral problems are prominent in children with TSC. Referrals for behavioral intervention and monitoring of parental stress should be included in the medical management of children with TSC.
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PMID:Behavior problems in children with tuberous sclerosis complex and parental stress. 1860 68

Self-injurious behavior (SIB) has been observed in people with tuberous sclerosis complex (TSC), although the frequency of SIB in TSC is largely unknown. SIB is associated with intellectual and developmental disabilities, but there is no single cause of SIB. We retrospectively examined the frequency of SIB in a population of 257 patients with TSC and determined possible associations with SIB. We found a 10% frequency of SIB in our TSC population. When compared with patients without psychiatric symptoms, we identified a significantly higher rate of electroencephalographic interictal spikes in the left frontal lobe and a significantly lower number of tubers in the left occipital, parietal, and posterior temporal lobes. We also found that frequency of TSC2 mutation, history of infantile spasms, history of seizures, mental retardation, and autism are significantly associated with SIB.
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PMID:Self-injurious behavior and tuberous sclerosis complex: frequency and possible associations in a population of 257 patients. 1870 61

Tuberous sclerosis complex (TSC) is an important cause of epilepsy, autism, and renal and pulmonary disease in children and adults. The clinical course of TSC and the prognosis and appropriate therapy for TSC patients are often different than that for individuals with epilepsy, renal tumors, or interstitial lung disease from other causes. This article reviews the current therapeutic recommendations for medical and surgical management of neurologic, renal, and pulmonary manifestations of TSC. In addition, recent clinical trials using inhibitors of the mammalian target of rapamycin (mTOR) have demonstrated regression of astrocytomas, angiofibromas, and angiomyoliomas, as well as improved pulmonary function in persons with TSC.
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PMID:Current management of tuberous sclerosis complex. 1875 97

Axon formation is fundamental for brain development and function. TSC1 and TSC2 are two genes, mutations in which cause tuberous sclerosis complex (TSC), a disease characterized by tumor predisposition and neurological abnormalities including epilepsy, mental retardation, and autism. Here we show that Tsc1 and Tsc2 have critical functions in mammalian axon formation and growth. Overexpression of Tsc1/Tsc2 suppresses axon formation, whereas a lack of Tsc1 or Tsc2 function induces ectopic axons in vitro and in the mouse brain. Tsc2 is phosphorylated and inhibited in the axon but not dendrites. Inactivation of Tsc1/Tsc2 promotes axonal growth, at least in part, via up-regulation of neuronal polarity SAD kinase, which is also elevated in cortical tubers of a TSC patient. Our results reveal key roles of TSC1/TSC2 in neuronal polarity, suggest a common pathway regulating polarization/growth in neurons and cell size in other tissues, and have implications for the understanding of the pathogenesis of TSC and associated neurological disorders and for axonal regeneration.
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PMID:Tuberous sclerosis complex proteins control axon formation. 1879 42

The recent development of several mouse models for tuberous sclerosis complex (TSC) provides in vivo systems to test new therapies for the neurological manifestations of TSC. Rapamycin is known to antagonize the effects of loss of TSC protein function in vitro and in mouse TSC models, rapamycin can prevent seizures and improve learning task performance. These findings provide new hope for TSC patients suffering from intractable seizures and possibly, for those with autism and cognitive disabilities.
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PMID:Do we have a cure for tuberous sclerosis complex? 1912 11

The high concordance for autism symptoms in monozygotic twin-pairs compared to di-zygotic twins and/or non-twin sib-ships suggests a high genetic determinism in autism. Those results have hypothesized multi-factorial determinism in accordance with family studies and mathematical models. However, linkage and association or candidate gene strategies have failed to-date to identify clearly involved mechanisms. Mental retardation (MR) is known as frequently associated to autism. Multiplex XLMR pedigrees have been reported with only one mutated patient having autism and MR: different X-located MR genes have been shown to be involved (NLGN4, MECP2, OPHN1, ZNF674 and FRAXA) which does not suggest that they could be "autism genes". Tuberous sclerosis studies and report of numerous autosomal domains shown deleted in MR-autistic subjects suggest that several autosomal dominant (AD) genes could be also involved in MR with autism. Whereas multiplex AD-MR families are rare, AD de novo mutations could explain numerous sporadic situations of non-specific MR and of autism with MR, in accordance with twin studies. Finally, we hypothesize that in those autistic subjects with mendelian MR, the XL-MR or AD-MR gene (G1) would pave the way for a second Mendelian factor (G2) responsible for autism symptoms.
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PMID:Could autism with mental retardation result from digenism and frequent de novo mutations? 1916 Jan 28

Epilepsy associated with tuberous sclerosis complex (TSC) is characterized by early onset and intractable seizures in the majority of children. There is a solid evidence of clinical efficacy of vigabatrin in interrupting infantile spasms associated with TSC. Due to an early diagnosis we were able to start vigabatrin at the very early onset of seizures in 10 children, who subsequently underwent a long-term neurodevelopmental follow-up. At the final evaluation, a seizure free status was achieved in 50% of patients; 30% of individuals had a normal or borderline mental development, with no patients developing severe mental retardation and/or autism. Early control of seizures has a crucial role in preventing subsequent epileptic encephalopathy, and in reducing the cognitive/behavioural consequences of seizures, but does not guarantee for a normal mental outcome in children with TSC.
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PMID:Early control of seizures improves long-term outcome in children with tuberous sclerosis complex. 1936 1

Tuberous sclerosis complex (TSC) is a neurogenetic disorder caused by loss-of-function mutations in either the TSC1 or TSC2 genes and frequently results in prominent CNS manifestations, including epilepsy, mental retardation, and autism spectrum disorder. The TSC1/TSC2 protein complex plays a major role in controlling the Ser/Thr kinase mammalian target of rapamycin (mTOR), which is a master regulator of protein synthesis and cell growth. In this study, we show that endoplasmic reticulum (ER) stress regulates TSC1/TSC2 complex to limit mTOR activity. In addition, Tsc2-deficient rat hippocampal neurons and brain lysates from a Tsc1-deficient mouse model demonstrate both elevated ER and oxidative stress. In Tsc2-deficient neurons, the expression of stress markers such as CHOP and HO-1 is increased, and this increase is completely reversed by the mTOR inhibitor rapamycin both in vitro and in vivo. Neurons lacking a functional TSC1/TSC2 complex have increased vulnerability to ER stress-induced cell death via the activation of the mitochondrial death pathway. Importantly, knockdown of CHOP reduces oxidative stress and apoptosis in Tsc2-deficient neurons. These observations indicate that ER stress modulates mTOR activity through the TSC protein complex and that ER stress is elevated in cells lacking this complex. They also suggest that some of the neuronal dysfunction and neurocognitive deficits seen in TSC patients may be attributable to ER and oxidative stress and therefore potentially responsive to agents moderating these pathways.
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PMID:Tuberous sclerosis complex activity is required to control neuronal stress responses in an mTOR-dependent manner. 1942 Feb 59


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