The GATOR1 complex is located at the upstream of the mTOR signal pathway and can regulate the function of mTORC1. Genetic variants of the GATOR1 complex are closely associated with epilepsy, developmental delay, cerebral cortical malformation and tumor. This article has reviewed the research progress in diseases associated with genetic variants of the GATOR1 complex, with the aim to provide a reference for the diagnosis and treatment of such patients.
Humans ; GTPase-Activating Proteins/metabolism* ; Signal Transduction/genetics* ; Mechanistic Target of Rapamycin Complex 1/metabolism* ; Epilepsy/genetics* ; Neoplasms

OBJECTIVES: To summarize the clinical phenotype and genetic characteristics of children with autosomal dominant mental retardation type 5 caused by SYNGAP1 gene mutations. METHODS: A retrospective analysis was performed on the medical data of 8 children with autosomal dominant mental retardation type 5 caused by SYNGAP1 gene mutations who were diagnosed and treated in the Department of Pediatrics, Xiangya Hospital of Central South University. RESULTS: The mean age of onset was 9 months for the 8 children. All children had moderate-to-severe developmental delay (especially delayed language development), among whom 7 children also had seizures. Among these 8 children, 7 had novel heterozygous mutations (3 with frameshift mutations, 2 with nonsense mutations, and 2 with missense mutations) and 1 had 6p21.3 microdeletion. According to the literature review, there were 48 Chinese children with mental retardation caused by SYNGAP1 gene mutations (including the children in this study), among whom 40 had seizures, and the mean age of onset of seizures was 31.4 months. Frameshift mutations (15/48, 31%) and nonsense mutations (19/48, 40%) were relatively common in these children. In terms of treatment, among the 33 children with a history of epileptic medication, 28 (28/33, 85%) showed response to valproic acid antiepileptic treatment and 16 (16/33, 48%) achieved complete seizure control after valproic acid monotherapy or combined therapy. CONCLUSIONS Children with autosomal dominant mental retardation type 5 caused by SYNGAP1 gene mutations tend to have an early age of onset, and most of them are accompanied by seizures. These children mainly have frameshift and nonsense mutations. Valproic acid is effective for the treatment of seizures in most children.
Child ; Humans ; Intellectual Disability/diagnosis* ; Codon, Nonsense ; Retrospective Studies ; Valproic Acid ; ras GTPase-Activating Proteins/genetics* ; Mutation ; Seizures/genetics*

OBJECTIVE: To explore the genetic basis for a child with mental retardation. METHODS: Whole exome sequencing was carried out for the child. Candidate variant was screened based on his clinical features and verified by Sanger sequencing. RESULTS: The child was found to harbor a c.995_1002delAGACAAAA(p.Asp332AlafsTer84) frameshift variant in the SYNGAP1 gene. Bioinformatic analysis suggested it to be pathogenic. The same variant was not detected in either parent. CONCLUSION The c.995_1002delAGACAAAA(p.Asp332AlafsTer84) frameshift variant of the SYNGAP1 gene probably underlay the mental retardation in this child. Above finding has expanded the spectrum of SYNGAP1 gene variants and provided a basis for the diagnosis and treatment for this child.
Child ; Humans ; Intellectual Disability/genetics* ; Frameshift Mutation ; High-Throughput Nucleotide Sequencing ; Computational Biology ; Heterozygote ; Mutation ; ras GTPase-Activating Proteins/genetics*

Toxoplasma gondii is a worldwide parasite that can infect almost all kinds of mammals and cause fatal toxoplasmosis in immunocompromised patients. Apoptosis is one of the principal strategies of host cells to clear pathogens and maintain organismal homeostasis, but the mechanism of cell apoptosis induced by T. gondii remains obscure. To explore the apoptosis influenced by T. gondii, Vero cells infected or uninfected with the parasite were subjected to apoptosis detection and subsequent dual RNA sequencing (RNA-seq). Using high-throughput Illumina sequencing and bioinformatics analysis, we found that pro-apoptosis genes such as DNA damage-inducible transcript 3 (DDIT3), growth arrest and DNA damage-inducible α (GADD45A), caspase-3 (CASP3), and high-temperature requirement protease A2 (HtrA2) were upregulated, and anti-apoptosis genes such as poly(adenosine diphosphate (ADP)-ribose) polymerase family member 3 (PARP3), B-cell lymphoma 2 (Bcl-2), and baculoviral inhibitor of apoptosis protein (IAP) repeat containing 5 (BIRC5) were downregulated. Besides, tumor necrosis factor (TNF) receptor-associated factor 1 (TRAF1), TRAF2, TNF receptor superfamily member 10b (TNFRSF10b), disabled homolog 2 (DAB2)‍-interacting protein (DAB2IP), and inositol 1,4,5-trisphosphate receptor type 3 (ITPR3) were enriched in the upstream of TNF, TNF-related apoptosis-inducing ligand (TRAIL), and endoplasmic reticulum (ER) stress pathways, and TRAIL-receptor 2 (TRAIL-R2) was regarded as an important membrane receptor influenced by T. gondii that had not been previously considered. In conclusion, the T. gondii RH strain could promote and mediate apoptosis through multiple pathways mentioned above in Vero cells. Our findings improve the understanding of the T. gondii infection process through providing new insights into the related cellular apoptosis mechanisms.
Animals ; Apoptosis ; Chlorocebus aethiops ; Gene Expression Profiling ; Humans ; Mammals/genetics* ; Toxoplasma/genetics* ; Toxoplasmosis/pathology* ; Vero Cells ; ras GTPase-Activating Proteins/genetics*

Humans ; Epilepsy/genetics* ; Epilepsies, Partial/genetics* ; Mutation ; GTPase-Activating Proteins/genetics*

Asian Continental Ancestry Group ; Child, Preschool ; Electroencephalography ; Female ; GTPase-Activating Proteins ; genetics ; Humans ; Magnetic Resonance Imaging ; Mutation ; genetics ; Spasms, Infantile ; diagnostic imaging ; genetics

OBJECTIVE: To report on a child with mental retardation caused by SYNGAP1 gene mutation. METHODS: Peripheral blood samples were collected from the proband and her parents. High throughput sequencing (HTS) was employed for screening for potential mutation in the patient. Suspected mutation was validated by Sanger sequencing of the child and her parents. RESULTS: By HTS, a previously unknown mutation [c.1656C>A (p.C552*)] was found in exon 10 of the SYNGAP1 gene in the proband. Sanger sequencing confirmed the heterozygous nature of the mutation and that neither of her parents carried the same mutation. CONCLUSION The dysmorphism and developmental delay of the child were probably due to the pathogenic mutation of the SYNGAP1 gene. HTS can facilitate elucidation of the genetic etiology with efficiency, which has great significance in the diagnosis, treatment and prognosis of the child.
Child ; Exons ; Female ; Heterozygote ; High-Throughput Nucleotide Sequencing ; Humans ; Intellectual Disability ; genetics ; Mutation ; ras GTPase-Activating Proteins ; genetics

The methylcytosine dioxygenases TET proteins (TET1, TET2, and TET3) play important regulatory roles in neural function. In this study, we investigated the role of TET proteins in neuronal differentiation using Neuro2a cells as a model. We observed that knockdown of TET1, TET2 or TET3 promoted neuronal differentiation of Neuro2a cells, and their overexpression inhibited VPA (valproic acid)-induced neuronal differentiation, suggesting all three TET proteins negatively regulate neuronal differentiation of Neuro2a cells. Interestingly, the inducing activity of TET protein is independent of its enzymatic activity. Our previous studies have demonstrated that srGAP3 can negatively regulate neuronal differentiation of Neuro2a cells. Furthermore, we revealed that TET1 could positively regulate srGAP3 expression independent of its catalytic activity, and srGAP3 is required for TET-mediated neuronal differentiation of Neuro2a cells. The results presented here may facilitate better understanding of the role of TET proteins in neuronal differentiation, and provide a possible therapy target for neuroblastoma.
Animals ; Catalytic Domain ; Cell Differentiation ; drug effects ; physiology ; Cell Line, Tumor ; DNA-Binding Proteins ; antagonists & inhibitors ; genetics ; metabolism ; Enzyme Inhibitors ; pharmacology ; GTPase-Activating Proteins ; genetics ; metabolism ; Immunohistochemistry ; Mice ; Microscopy, Fluorescence ; Neuroblastoma ; metabolism ; pathology ; Protein Isoforms ; antagonists & inhibitors ; genetics ; metabolism ; Proto-Oncogene Proteins ; antagonists & inhibitors ; genetics ; metabolism ; RNA Interference ; RNA, Messenger ; metabolism ; RNA, Small Interfering ; metabolism ; Valproic Acid ; pharmacology

Skeletal fluorosis is a chronically metabolic bone disease with extensive hyperostosis osteosclerosis caused by long time exposure to fluoride. Skeletal fluorosis brings about a series of abnormal changes of the extremity, such as joint pain, joint stiffness, bone deformity, etc. Differentiation and maturation of osteoblasts were regulated by osteoclasts via Sema4D/Plexin-B1 signaling pathway. Furthermore, the differentiation and maturation of osteoclasts are conducted by osteoblasts via RANKL/RANK/OPG pathway. Both of these processes form a feedback circuit which is a key link in skeletal fluorosis. In this study, an osteoblast-osteoclast co-culture model in vitro was developed to illustrate the mechanism of skeletal fluorosis. With the increase of fluoride concentration, the expression level of Sema4D was decreased and TGF-β1 was increased continuously. OPG/RANKL mRNA level, however, increased gradually. On the basis of that, the inhibition of Sema4D/Plexin-B1/RhoA/ROCK signaling pathway caused by fluoride promoted the level of TGF-β1 and activated the proliferation of osteoblasts. In addition, osteroprotegerin (OPG) secreted by osteoblasts was up-regulated by fluoride. The competitive combination of OPG and RANKL was strengthened and the combination of RANKL and RANK was hindered. And then the differentiation and maturation of osteoclasts were inhibited, and bone absorption was weakened, leading to skeletal fluorosis.
Animals ; Antigens, CD ; genetics ; metabolism ; Cell Proliferation ; drug effects ; Feedback, Physiological ; Fetus ; Fluorides ; pharmacology ; GTPase-Activating Proteins ; genetics ; metabolism ; Gene Expression Regulation, Developmental ; Osteoblasts ; drug effects ; metabolism ; pathology ; Osteoclasts ; drug effects ; metabolism ; pathology ; Osteogenesis ; drug effects ; genetics ; Osteoprotegerin ; genetics ; metabolism ; RANK Ligand ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Rats ; Receptor Activator of Nuclear Factor-kappa B ; genetics ; metabolism ; Receptors, Cell Surface ; genetics ; metabolism ; Semaphorins ; genetics ; metabolism ; Signal Transduction ; Transforming Growth Factor beta1 ; genetics ; metabolism ; rho-Associated Kinases ; genetics ; metabolism ; rhoA GTP-Binding Protein ; genetics ; metabolism

Abnormal proliferation of vascular smooth muscle cells (VSMCs) plays an important role in several pathological processes of cardiovascular diseases. In this study, the effects of XCT790, a potent and selective inverse agonist of estrogen-related receptor alpha (ERRalpha), on rat VSMCs proliferation and related signal pathways were investigated. The proliferative activity of VSMCs was determined by CCK-8 assay. The mRNA levels of ERRalpha, PGC-1alpha, OPN and MCAD were assayed by RT-PCR. The protein levels of ERRalpha, ERK2 and p-ERK1/2 were evaluated by Western blotting. ELISA was used to assess the protein expression of VEGF. The results showed that XCT790 (5-20 micromol x L(-1)) inhibited rat VSMCs proliferation, and the expression of ERRalpha and its target genes, as well as p-ERK1/2, were also inhibited. XCT790 inhibited VSMCs proliferation in a dose-dependent manner at the dose range from 5 to 20 micromol x L(-1) and in a time-dependent manner at the dose range from 10 to 20 micromol x L(-1). These findings demonstrate that XCT790 inhibits rat VSMCs proliferation by down-regulating the gene level of ERRalpha and thus inhibiting the ERK signal pathway, suggesting that ERRalpha may be a novel potential target for therapeutic approaches to inhibit VSMCs proliferation, which plays an important role in several cardiovascular diseases.
Animals ; Cadherins ; genetics ; metabolism ; Cell Proliferation ; drug effects ; Cells, Cultured ; Cytoskeletal Proteins ; genetics ; metabolism ; Dose-Response Relationship, Drug ; GTPase-Activating Proteins ; genetics ; metabolism ; MAP Kinase Signaling System ; Male ; Muscle, Smooth, Vascular ; cytology ; Myocytes, Smooth Muscle ; cytology ; drug effects ; metabolism ; Nitriles ; administration & dosage ; pharmacology ; Nuclear Proteins ; genetics ; metabolism ; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha ; Phosphorylation ; RNA, Messenger ; metabolism ; Rats ; Rats, Sprague-Dawley ; Receptors, Estrogen ; genetics ; metabolism ; Thiazoles ; administration & dosage ; pharmacology ; Transcription Factors ; genetics ; metabolism ; Vascular Endothelial Growth Factor A ; genetics ; metabolism