OBJECTIVES: To investigate the regulatory role of Ral guanine nucleotide dissociation stimulator-like 1 (RGL1) in metastasis of colorectal cancer (CRC). METHODS: We analyzed the differential expression of RGL1 between metastatic and non-metastatic CRC in GEO database, and examined its expression in 25 patients with metastatic CRC and 25 patients with non-metastatic CRC treated in Zhujiang Hospital between January, 2020 and December, 2022 using quantitative PCR (qPCR) and immunohistochemistry. HCT116 cell lines with stable RGL1 overexpression and SW480 cells with RGL1 knockdown were established using lentiviral vecors, and the changes in invasion and migration abilities of the cells were assessed using Transwell invasion and migration assays. The transduced cells were injected into the serosa of the cecum of nude mice, and tumor growth and liver metastasis were observed 8 weeks later. Fibronectin adhesion assays and immunofluorescence experiments were employed to assess the relationship between RGL1 and focal adhesion formation, and co-immuno-precipitation assays were performed to explore the interaction between RGL1 and GTPase activation. RESULTS: Compared with non-metastatic CRC, metastatic CRC showed significantly upregulated expression of RGL1. HCT116 cells overexpressing RGL1 exhibited obviously enhanced migration and invasion in vitro with increased capacity for liver metastasis in nude mice. RGL1 overexpression strongly accelerated focal adhesion assembly, facilitated the formation of motile focal adhesions, and enhanced the binding of activated CDC42/RAC1 complex to RGL1. CONCLUSIONS RGL1 is highly expressed in metastatic CRC and promotes distant metastasis of CRC by activating the CDC42/RAC1 complex to facilitate the formation of motile focal adhesions. These findings suggest that RGL1 can potentially serve as a therapeutic target for CRC metastasis.
Humans ; Colorectal Neoplasms/metabolism* ; cdc42 GTP-Binding Protein/metabolism* ; Animals ; Mice, Nude ; rac1 GTP-Binding Protein/metabolism* ; Cell Movement ; Mice ; Focal Adhesions/metabolism* ; Neoplasm Metastasis ; Cell Line, Tumor ; HCT116 Cells ; Up-Regulation ; Neoplasm Invasiveness ; Adaptor Proteins, Signal Transducing ; Female ; Rho Guanine Nucleotide Exchange Factors

OBJECTIVES: To investigate the subcellular localization and biological functions of transmembrane protein 240 (TMEM240). METHODS: NCBI BLAST and TMHMM bioinformatics software were used for protein sequence analysis and prediction of transmembrane domain of TMEM240. Brain tissues from male C57BL/6 mice (18-20 days old) were examined for distribution of TMEM240 using in situ hybridization, and qPCR and Western blotting were used to detect TMEM240 expression in different mouse tissues and in cortical neurons at different time points (n=3). In the in vitro experiment, HepG2 and Neuro-2a cells were transfected with plasmids for overexpression of TMEM240, and subcellular localization of TMEM240 was analyzed using cell imaging. In primary cultures of cortical neurons isolated from C57BL/6 mice, TMEM240 expression and its biological functions were investigated using qPCR, Western blotting, and immunofluorescence staining. RESULTS: Human and mouse TMEM240 proteins share a 97.69% similarity in the protein sequences, and both are transmembrane proteins with two transmembrane domains. TMEM240 mRNA and protein were highly expressed in mouse brain tissues and cortical neurons. In isolated mouse cortical neurons, TMEM240 expression reached the peak level after primary culture for 9 days and distributed in scattered spots within the cells. In HepG2 cells, TMEM240 was characterized as intracellular membrane structures and showed 80% colocalization with peroxisomes. In Neuro-2a cells, TMEM240 overexpression caused significant enhancement of the expressions of Rho GDP dissociation inhibitor β (ARHGDIB) at both the mRNA and protein levels. CONCLUSIONS TMEM240 is a novel intracellular subcellular structure specifically expressed in neurons with significant potential for targeted cellular function regulation.
Animals ; Humans ; Mice ; Peroxisomes/metabolism* ; Membrane Proteins/genetics* ; Mice, Inbred C57BL ; Neurons/metabolism* ; Male ; rho-Specific Guanine Nucleotide Dissociation Inhibitors ; Hep G2 Cells ; Brain/metabolism*

The accumulation of deoxyribonucleic acid (DNA) oxidative damage mediated by reactive oxygen species (ROS) is closely associated with liver diseases. 8-Oxoguanine (8-OxoG), a prevalent DNA oxidation product, plays a significant role in liver disease progression. The base excision repair (BER) pathway, comprising over 30 proteins including 8-OxoG DNA glycosylase1 (OGG1), MutY homolog (MUTYH), and MutT homolog protein 1 (MTH1), is responsible for the clearance and mismatch repair of 8-OxoG. Abnormally high levels of 8-OxoG and dysregulated expression and function of 8-OxoG repair enzymes contribute to the onset and development of liver diseases. Consequently, targeting the 8-OxoG production and repair system with agonists or inhibitors may offer a promising approach to liver disease treatment. This review summarizes the impact of 8-OxoG accumulation and dysregulated repair enzymes on various liver diseases, including viral liver disease, alcoholic liver disease (ALD), metabolic dysfunction-associated steatotic liver disease (MASLD), cholestatic liver disease (CLD), liver fibrosis, cirrhosis, and liver cancer. Additionally, we review natural constituents as potential therapeutic agents that regulate 8-OxoG production, repair enzymes, and repair system-related signal pathways in oxidative damage-induced liver diseases.
Humans ; Liver Diseases/genetics* ; Biological Products/pharmacology* ; DNA Repair/drug effects* ; Guanine/metabolism* ; Animals ; Disease Progression ; DNA Damage ; Oxidative Stress

Guanine nucleotide exchange factor Kalirin-7 (Kal-7) is a key factor in synaptic plasticity and plays an important regulatory role in the brain. Abnormal synaptic function leads to the weakening of cognitive functions such as learning and memory, accompanied by abnormal expression of Kal-7, which in turn induces a variety of neurodegenerative diseases. Exercise can upregulate the expression of Kal-7 in related brain regions to alleviate neurodegenerative diseases. By reviewing the literature on Kal-7 and neurodegenerative diseases, as well as the research progress of exercise intervention, this paper summarizes the role and possible mechanism of Kal-7 in the improvement of neurodegenerative diseases by exercise and provides a new rationale for the basic and clinical research on the prevention and treatment of neurodegenerative diseases by exercise.
Humans ; Neurodegenerative Diseases/therapy* ; Guanine Nucleotide Exchange Factors/metabolism* ; Exercise Therapy

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*

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*

Objective: To analyze guanine nucleotide-binding protein subunit beta-2-like 1 (GNB2L1) expression based on bioinformatics, so as to evaluate its role and its relationship with survival rate during the occurrence and development of hepatocellular carcinoma. Methods: GEPIA, UALCAN and HPA databases were used to analyze the expression level of GNB2L1 and its relationship with HCC survival rate. Mutations in the GNB2L1 gene and their impact on survival were analyzed using the cBioPortal database. LinkedOmics database was used to analyze GNB2L1-related genes in HCC. Gene Ontology (GO) functional annotation and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis were performed simultaneously. STEING database was used to construct the GNB2L1 protein interaction network. TIMER database was used to analyze the relationship between GNB2L1 gene expression and immune infiltration in hepatocellular carcinoma. Differential expression of GNB2L1 in plasma platelets of HCC patients and healthy controls was analyzed using mRNA-based sequencing technology. Data between groups were compared using an independent-samples t-test. Results: GNB2L1 expression level was significantly increased in HCC tissues (P<0.05), and its expression was significantly correlated with body weight, classification and stage (P<0.05). The overall survival rate was higher in GNB2L1 low expression group (P<0.001). GNB2L1 and its related genes were related to biological process regulation, metabolic process, protein binding, oxidative phosphorylation, JAK-STAT signaling pathway, Ras signaling pathway and so on. GNB2L1 had interaction with RPS12, RPS11 and RPL19, and participated in multiple biological processes such as liver regeneration and positive regulation of endogenous apoptotic signaling pathway. GNB2L1 expression was significantly positively correlated with the infiltration degree of various immune cells in HCC (P<0.05). Cox regression analysis showed that GNB2L1 was an independent risk factor for lower survival rate in patients with HCC [Hazard ratio (95% confidence interval)=1.456 (1.034~2.051), P=0.031]. GNB2L1expression levels were significantly higher in platelets of HCC patients than that of healthy controls (10.40±1.36 vs. 9.58±0.51, t=2.194, P=0.037). Conclusion: GNB2L1 has high expression and close relationship to survival rate in HCC. Therefore, GNB2L1 may be a potential biomarker of HCC.
Humans ; Carcinoma, Hepatocellular/pathology* ; Computational Biology ; Liver Neoplasms/pathology* ; Protein Subunits/metabolism* ; Gene Expression Profiling ; Gene Expression Regulation, Neoplastic ; RNA, Messenger ; Guanine Nucleotides ; Gene Expression ; Biomarkers, Tumor/genetics*

To interact with the egg, the spermatozoon must undergo several biochemical and motility modifications in the female reproductive tract, collectively called capacitation. Only capacitated sperm can undergo acrosomal exocytosis, near or on the egg, a process that allows the sperm to penetrate and fertilize the egg. In the present study, we investigated the involvement of cyclic adenosine monophosphate (cAMP)-dependent processes on acrosomal exocytosis. Inhibition of protein kinase A (PKA) at the end of capacitation induced acrosomal exocytosis. This process is cAMP-dependent; however, the addition of relatively high concentration of the membrane-permeable 8-bromo-cAMP (8Br-cAMP, 0.1 mmol l^-1) analog induced significant inhibition of the acrosomal exocytosis. The induction of acrosomal exocytosis by PKA inhibition was significantly inhibited by an exchange protein directly activated by cAMP (EPAC) ESI09 inhibitor. The EPAC selective substrate activated AE at relatively low concentrations (0.02-0.1 μmol l^-1), whereas higher concentrations (>5 μmol l^-1) were inhibitory to the AE induced by PKA inhibition. Inhibition of PKA revealed about 50% increase in intracellular cAMP levels, conditions under which EPAC can be activated to induce the AE. Induction of AE by activating the actin severing-protein, gelsolin, which causes F-actin dispersion, was inhibited by the EPAC inhibitor. The AE induced by PKA inhibition was mediated by phospholipase C activity but not by the Ca²⁺-channel, CatSper. Thus, inhibition of PKA at the end of the capacitation process induced EPAC/phospholipase C-dependent acrosomal exocytosis. EPAC mediates F-actin depolymerization and/or activation of effectors downstream to F-actin breakdown that lead to acrosomal exocytosis.
8-Bromo Cyclic Adenosine Monophosphate/pharmacology* ; Acrosome/metabolism* ; Acrosome Reaction/drug effects* ; Calcimycin/pharmacology* ; Cyclic AMP/metabolism* ; Cyclic AMP-Dependent Protein Kinases/antagonists & inhibitors* ; Exocytosis/drug effects* ; Guanine Nucleotide Exchange Factors/metabolism* ; Humans ; Male ; Protein Kinase Inhibitors/pharmacology* ; Signal Transduction/drug effects* ; Spermatozoa/metabolism* ; Thapsigargin/pharmacology*

BACKGROUND/AIMS: Before tenofovir (TDF) become available in South Korea, combination therapy with entecavir (ETV) and adefovir (ADV) was the most potent regimen for chronic hepatitis B (CHB) patients who fail to respond to rescue therapy for drug resistance. We analyzed the efficacy of ETV-ADV combination therapy and investigated the clinical and clonal results of TDF-based rescue therapy in CHB patients refractory to this combination. METHODS: We retrospectively reviewed the medical records of CHB patients treated for up to 3 years with ETV-ADV combination therapy as a rescue therapy for drug resistance. In cases refractory to this combination, clinical and clonal analyses were performed for TDF-based rescue therapy. RESULTS: The analysis was performed on 48 patients. Twelve patients achieved a virological response (VR) within 3 years. A VR was subsequently achieved in nine of the ten patients without a VR who switched to TDF monotherapy. A VR was also achieved in six of the seven patients who switched to lamivudine-TDF combination therapy, and in two of the two patients who switched to ETV-TDF combination therapy. In an in vitro susceptibility test, viral replication was detected with TDF monotherapy but not with ETV-TDF combination therapy. CONCLUSIONS: The efficacy of ETV-ADV combination therapy was insufficient in CHB patients who were refractory to rescue therapy. A more potent regimen such as ETV-TDF combination therapy may be considered in such refractory cases.
Adenine/*analogs & derivatives/therapeutic use ; Adult ; Aged ; Antiviral Agents/*therapeutic use ; DNA, Viral/analysis/metabolism ; Drug Resistance, Viral ; Drug Therapy, Combination ; Female ; Guanine/*analogs & derivatives/therapeutic use ; Hepatitis B virus/genetics/isolation & purification ; Hepatitis B, Chronic/*drug therapy/virology ; Humans ; Male ; Middle Aged ; Organophosphonates/*therapeutic use ; Polymerase Chain Reaction ; Republic of Korea ; Retrospective Studies ; Tenofovir/*therapeutic use ; Treatment Outcome

BACKGROUND/AIMS: Before tenofovir (TDF) become available in South Korea, combination therapy with entecavir (ETV) and adefovir (ADV) was the most potent regimen for chronic hepatitis B (CHB) patients who fail to respond to rescue therapy for drug resistance. We analyzed the efficacy of ETV-ADV combination therapy and investigated the clinical and clonal results of TDF-based rescue therapy in CHB patients refractory to this combination. METHODS: We retrospectively reviewed the medical records of CHB patients treated for up to 3 years with ETV-ADV combination therapy as a rescue therapy for drug resistance. In cases refractory to this combination, clinical and clonal analyses were performed for TDF-based rescue therapy. RESULTS: The analysis was performed on 48 patients. Twelve patients achieved a virological response (VR) within 3 years. A VR was subsequently achieved in nine of the ten patients without a VR who switched to TDF monotherapy. A VR was also achieved in six of the seven patients who switched to lamivudine-TDF combination therapy, and in two of the two patients who switched to ETV-TDF combination therapy. In an in vitro susceptibility test, viral replication was detected with TDF monotherapy but not with ETV-TDF combination therapy. CONCLUSIONS: The efficacy of ETV-ADV combination therapy was insufficient in CHB patients who were refractory to rescue therapy. A more potent regimen such as ETV-TDF combination therapy may be considered in such refractory cases.
Adenine/*analogs & derivatives/therapeutic use ; Adult ; Aged ; Antiviral Agents/*therapeutic use ; DNA, Viral/analysis/metabolism ; Drug Resistance, Viral ; Drug Therapy, Combination ; Female ; Guanine/*analogs & derivatives/therapeutic use ; Hepatitis B virus/genetics/isolation & purification ; Hepatitis B, Chronic/*drug therapy/virology ; Humans ; Male ; Middle Aged ; Organophosphonates/*therapeutic use ; Polymerase Chain Reaction ; Republic of Korea ; Retrospective Studies ; Tenofovir/*therapeutic use ; Treatment Outcome