BACKGROUND: The human Rho guanine nucleotide exchange factor 11 (ARHGEF11) functions as an activator of Rho GTPases and is thought to influence insulin signaling. The R1467H variant of ARHGEF11 has been reported to be associated with susceptibility to type 2 diabetes mellitus (T2DM) in Western populations. METHODS: We investigated the effects of the R1467H variant on susceptibility to T2DM as well as related traits in a Korean population. We genotyped the R1467H (rs945508) of ARHGEF11 in 689 unrelated T2DM patients and 249 non-diabetic individuals and compared the clinical and biochemical characteristics according to different alleles. RESULTS: The H allele was significantly more frequent in T2DM cases than in controls (P = 0.037, 17.1% and 13.1%; respectively). H homozygocity was associated with a higher risk of T2DM compared to those with R/R or R/H genotype (odds ratio, 5.24; 95% confidence interval, 1.06 to 25.83; P = 0.042). The fasting plasma glucose, HbA1c, fasting insulin, HOMA2-IR and HOMA2-%beta levels did not differ significantly between different genotypes. CONCLUSION: Our study replicated associations of the ARHGEF11 polymorphism with increased risk of T2DM in a Korean population and thus supports previous data implicating a potential role of ARHGEF11 in the etiology of T2DM. Further studies revealing the underlying mechanism for this association are needed.
Alleles ; Diabetes Mellitus, Type 2 ; Fasting ; Genotype ; Glucose ; Guanine ; Guanine Nucleotide Exchange Factors ; Humans ; Insulin ; Plasma ; Polymorphism, Single Nucleotide ; rho GTP-Binding Proteins

OBJECTIVE: To explore the clinical characteristics of a child with early-onset infantile epileptic encephalopathy type 8 associated with synonymous variant of ARHGEF9 gene. METHODS: Clinical data of the patient was summarized. The child and his parents were subjected to trio-whole exome sequencing. RESULTS: The child has presented with global developmental delay, epilepsy, impulsive behavior, hypersensitivity to sound, and mental retardation. He was found to harbor a de novo synonymous variant c.741C>T (p.Cys247Cys) of the ARHGEF9 gene. RNA splicing analysis confirmed that the variant has led to abnormal splicing of exon 5, resulting in a 55-bp deletion. CONCLUSION The clinical features of ARHGEF9 gene-related early-onset infantile epileptic encephalopathy type 8 includes mental and motor developmental delay, epilepsy, auditory allergy, and hyperactivity impulsivity. For synonymous variant, in vitro study and transcriptional experiment may be carried out to evaluate its functional and splicing effect. Above finding has enriched the phenotypic and genotypic spectrum of the ARHGEF9 gene.
Child ; Epilepsy/genetics* ; Exons ; Humans ; Infant ; Intellectual Disability/genetics* ; Male ; Rho Guanine Nucleotide Exchange Factors/genetics* ; Spasms, Infantile/genetics*

OBJECTIVETo study the influence of lipopolysaccharide (LPS) on the permeability of rat brain microvascular endothelial cells (BMECs) and possible molecular mechanism.

METHODSMonolayers of primary rat BMECs were separated and cultured, and then treated with (LPS group) or without LPS (control group). The barrier integrity was measured by transendothelial electrical resistance (TEER) assay. The degrees of RhoA activation were determined by Pull-down assay. The expression levels of p115RhoGEF, zonula occludens-1 (ZO-1), occludin and claudin-5 proteins were detected by Western blot analysis.

RESULTSThe average TEER values of rat BMECs in the LPS group were 108.3±4.2 Ω•cm2 and 85.4±2.5 Ω•cm2 respectively 3 and 12 hrs after LPS treatment, which were significantly lower than that in the control group (159.0±8.6 Ω•cm2). Compared with the control group, the activity of RhoA started to increase 5 minutes after LPS treatment, and the expression of p115RhoGEF protein started to increase 1 hr after LPS treatment and the cellular protein levels of ZO-1, occludin and claudin-5 decreased significantly 3 hrs after LPS treatment in the LPS group (P<0.05).

CONCLUSIONSLPS may activate the p115RhoGEF/RhoA pathway and decrease protein expression of ZO-1, occludin and claudin-5, resulting in an increased permeability of rat BMECs.

Animals ; Brain ; blood supply ; Capillary Permeability ; drug effects ; Electric Impedance ; Endothelial Cells ; drug effects ; metabolism ; Guanine Nucleotide Exchange Factors ; analysis ; Lipopolysaccharides ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Rho Guanine Nucleotide Exchange Factors ; Tight Junctions ; chemistry ; rhoA GTP-Binding Protein ; analysis

BACKGROUND: The normal functions of the cell cycle inhibitor p16INK4a are frequently inactivated in many human cancers. Over 80% of hepatocellular carcinoma (HCC) cases lack a functional p16/Rb pathway. p16/Rb pathway, as well as p53 pathway, is considered as one of key components of tumor suppression. METHODS: To study the roles of p16INK4a in HCC, a stable cell line expressing exogenous p16 was generated from SNU-449 hepatocellular carcinoma cells lacking endogenous p16, and suppression subtractive hybridization (SSH) was performed in parallel with the control cells. RESULTS: 1) SSH identifies fibronectin (FN1), crystallin alphaB (CRYAB), Rac1, WASP, RhoGEF, and CCT3 as differentially-expressed genes. 2) Among the selected genes, the up- regulation of FN1 and CRYAB was confirmed by Northern blot, RT-PCR and by proteomic methods. CONCLUSION: These genes are likely to be associated with the induction of stress fiber and stabilization of cytoskeleton. Further studies are required to clarify the possible role of p16 in the signal transduction pathway.
Blotting, Northern ; Carcinoma, Hepatocellular* ; Cell Cycle ; Cell Line ; Crystallins ; Cytoskeleton ; Fibronectins ; Gene Expression* ; Humans ; Rho Guanine Nucleotide Exchange Factors ; Signal Transduction ; Stress Fibers ; Wasps

The radial migration of cortical pyramidal neurons (PNs) during corticogenesis is necessary for establishing a multilayered cerebral cortex. Neuronal migration defects are considered a critical etiology of neurodevelopmental disorders, including autism spectrum disorders (ASDs), schizophrenia, epilepsy, and intellectual disability (ID). TRIO is a high-risk candidate gene for ASDs and ID. However, its role in embryonic radial migration and the etiology of ASDs and ID are not fully understood. In this study, we found that the in vivo conditional knockout or in utero knockout of Trio in excitatory precursors in the neocortex caused aberrant polarity and halted the migration of late-born PNs. Further investigation of the underlying mechanism revealed that the interaction of the Trio N-terminal SH3 domain with Myosin X mediated the adherence of migrating neurons to radial glial fibers through regulating the membrane location of neuronal cadherin (N-cadherin). Also, independent or synergistic overexpression of RAC1 and RHOA showed different phenotypic recoveries of the abnormal neuronal migration by affecting the morphological transition and/or the glial fiber-dependent locomotion. Taken together, our findings clarify a novel mechanism of Trio in regulating N-cadherin cell surface expression via the interaction of Myosin X with its N-terminal SH3 domain. These results suggest the vital roles of the guanine nucleotide exchange factor 1 (GEF1) and GEF2 domains in regulating radial migration by activating their Rho GTPase effectors in both distinct and cooperative manners, which might be associated with the abnormal phenotypes in neurodevelopmental disorders.
Autism Spectrum Disorder/metabolism* ; Cell Movement/genetics* ; Humans ; Interneurons/metabolism* ; Neurodevelopmental Disorders/genetics* ; Neurons/metabolism* ; Rho Guanine Nucleotide Exchange Factors/genetics*

PURPOSE: We investigated the protective effects of the herbal formulation KH-204 in the bladder of androgen-deprived rats. MATERIALS AND METHODS: Male rats aged eight weeks were randomly divided into four groups, containing eight rats each: sham operation only (normal control group), androgen-deprived only (androgen-deprived control group), and androgen-deprived followed by treatment with 200 mg/kg or 400 mg/kg of KH-204. After 0.5 mg/kg of leuprorelin was subcutaneously injected in the androgen-deprived groups, the oral administration of either distilled water in the two control groups or KH-204 in the treatment group was continued for four weeks. Serum testosterone levels, RhoGEF levels, nitric oxide (NO)-cyclic guanosine monophosphate (cGMP)-related parameters, oxidative stress, and histologic changes were evaluated after treatment. RESULTS: Treatment with the herbal formulation KH-204 (1) increased serum testosterone levels; (2) restored the expression of RhoGEFs, endothelial NO synthase, and neuronal NO synthase; (3) increased the expression of superoxide dismutase; and (4) decreased bladder fibrosis. CONCLUSIONS: Our results suggest that the positive effects of KH-204 on the urinary bladder may be attributed to its antioxidant effects or to an elevation in NO-cGMP activity.
Administration, Oral ; Animals ; Antioxidants ; Fibrosis ; Guanosine Monophosphate ; Humans ; Hypogonadism ; Leuprolide ; Male ; Neurons ; Nitric Oxide ; Nitric Oxide Synthase ; Oxidative Stress ; Phytotherapy ; Rats* ; Rho Guanine Nucleotide Exchange Factors ; Superoxide Dismutase ; Testosterone ; Urinary Bladder* ; Water

Neuronal differentiation is a complex biological process accompanying cytoskeletal reorganization, including neurite outgrowth and growth cone formation. Therefore, neuronal differentiation is critically regulated by actin-related signaling proteins, such as small Rho GTPases, guanine nucleotide exchange factors (GEFs), and myosins. This study will demonstrate the change in activity of three small Rho GTPases, Rac, Cdc42, and Rho A, by treatment with blebbistatin (BBS), a specific inhibitor for myosin, during bFGF-induced neurite outgrowth in PC12 cells. Treatment with BBS induced morphological changes in growth cones and neurites during differentiation. A marked increase in protrusion and filopodia structures in growth cones, the shaft of neuritis, and cell membranes was observed in the cells treated with BBS. Activity of Rho GTPases showed the alterations in response to BBS. Activities of both Rac and Rho A were inhibited by BBS in a time-dependent manner. By contrast, Cdc42 activity was not changed by BBS. These results suggest that inactivation of myosin II by BBS induced morphological changes in neurites and growth cones and distinct regulation of three Rho GTPases during differentiation of PC12 cells.
Animals ; Biological Processes ; Cell Membrane ; Growth Cones ; Guanine Nucleotide Exchange Factors ; Heterocyclic Compounds with 4 or More Rings ; Myosin Type II ; Myosins ; Neurites ; Neuritis ; Neurons ; PC12 Cells* ; Proteins ; Pseudopodia ; rho GTP-Binding Proteins*

OBJECTIVE: To determine if ARHGEF10 has a haploinsufficient effect and provide evidence to evaluate the severity, if any, during prenatal consultation. METHODS: Zebrafish was used as a model for generating mutant. The pattern of arhgef10 expression in the early stages of zebrafish development was observed using whole-mount in situ hybridization (WISH). CRISPR/Cas9 was applied to generate a zebrafish model with a single-copy or homozygous arhgef10 deletion. Activity and light/dark tests were performed in arhgef10 ^-/-, arhgef10 ^+/-, and wild-type zebrafish larvae. ARHGEF10 was knocked down using small interferon RNA (siRNA) in the SH-SY5Y cell line, and cell proliferation and apoptosis were determined using the CCK-8 assay and Annexin V/PI staining, respectively. RESULTS: WISH showed that during zebrafish embryonic development arhgef10 was expressed in the midbrain and hindbrain at 36-72 h post-fertilization (hpf) and in the hemopoietic system at 36-48 hpf. The zebrafish larvae with single-copy and homozygous arhgef10 deletions had lower exercise capacity and poorer responses to environmental changes compared to wild-type zebrafish larvae. Moreover, arhgef10 ^-/- zebrafish had more severe symptoms than arhgef10 ^+/- zebrafish. Knockdown of ARHGEF10 in human neuroblastoma cells led to decreased cell proliferation and increased cell apoptosis. CONCLUSION Based on our findings, ARHGEF10 appeared to have a haploinsufficiency effect.
Animals ; Annexin A5 ; Apoptosis ; Blotting, Western ; CRISPR-Associated Protein 9 ; CRISPR-Cas Systems ; Cell Line ; Cell Proliferation ; Cells, Cultured ; Flow Cytometry ; Genotype ; Humans ; In Situ Hybridization ; Larva/physiology* ; Phenotype ; RNA/isolation & purification* ; Real-Time Polymerase Chain Reaction/standards* ; Rho Guanine Nucleotide Exchange Factors/metabolism* ; Sincalide/analysis* ; Spectrophotometry/methods* ; Zebrafish/physiology*