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Braz. dent. j ; 31(3): 290-297, May-June 2020. tab, graf
Article in English | LILACS, BBO | ID: biblio-1132302


Abstract Chloride intracellular channel-4 (CLIC4) is regulated by p53 and tumor necrosis factor-α (TNF-α), it is linked to the increase of transforming growth factor-β (TGF-β), and myofibroblastic differentiation in skin carcinogenesis. This study analyzed the immunoexpression of CLIC4, p53, TGF-β, TNF-α, and α-SMA in 50 actinic cheilitis (AC) and 50 lower lip squamous cell carcinoma (LLSCC). AC and LLSCC immunoexpression were categorized as score 1 (<5% positive cells), 2 (5-50%) or 3 (>50%). For CLIC4, nuclear and cytoplasmic immunostaining of epithelial cells was considered individually. For morphologic analysis, the World Health Organization criteria were used to epithelial dysplasia grade of ACs, and Bryne grading of malignancy system was applied for LLSCC. Higher nuclear CLIC4 (CLIC4n) and TGF-β were observed in ACs with low-risk of transformation, while cytoplasmic CLIC4 (CLIC4c), p53 and TNF-α were higher in the high-risk cases (p<0.05). In LLSCCs, CLIC4c was higher in cases with lymph node metastasis, advanced clinical stages, and histological high-grade malignancy. p53 expression was higher in high-grade LLSCCs, whereas TGF-β decreased as the clinical stage and morphological grade progressed (p<0.05). ACs showed an increased expression of CLIC4n and TGF-β, while CLIC4c and α-SMA were higher in LLSCCs (p<0.0001). Both lesions showed negative correlation between CLIC4n and CLIC4c, while in LLSCCs, negative correlation was also verified between CLIC4c and p53, as well as CLIC4c and TGF-β (p<0.05). Change of CLIC4 from the nucleus to cytoplasm and alterations in p53, TGF-β, TNF-α, and α-SMA expression are involved in lip carcinogenesis.

Resumo O canal intracelular de cloreto 4 (CLIC4) é regulado pela p53 e fator de necrose tumoral α (TNF-α) e está relacionado ao aumento do fator de crescimento transformador β (TGF-β) e na diferenciação miofibroblástica na carcinogênese cutânea. Este estudo analisou a imunoexpressão de CLIC4, p53, TGF-β, TNF-α e α-SMA em 50 queilites actínicas (QA) e 50 carcinomas de células escamosas de lábio inferior (CCELI). A imunoexpressão da QA e CCELI foram categorizadas em escore 1 (<5% de células positivas), 2 (5-50%) ou 3 (>50%). Para CLIC4, a imunomarcação nuclear e citoplasmática das células epiteliais foi considerada separadamente. Para análise morfológica, foram utilizados os critérios da Organização Mundial da Saúde para a gradação das displasias epiteliais nas QAs, e o sistema de gradação de malignidade de Bryne foi utilizado para os casos de CCELIs. Alta imunoexpressão de CLIC4 nuclear (CLIC4n) e TGF-β foi observada em QA de baixo risco de transformação, enquanto CLIC4 citoplasmática (CLIC4c), p53 e TNF-α foram elevadas nos casos de alto risco (p<0.05). No CCELI, a imunoexpressão de CLIC4c foi maior em caos com metástase linfonodal, estágio clínico avançado e alto grau histológico de malignidade. A expressão de p53 foi elevada em CCELI de alto grau, enquanto o TGF-β diminuiu à medida que o estádio clínico e o grau morfológico progrediram (p<0.05). QAs exibiram uma elevada expressão de CLIC4n e TGF-β, enquanto o CLIC4c e α-SMA foram elevados em CCELIs (p<0.0001). Ambas as lesões mostraram correlação negativa entre CLIC4n e CLIC4c, enquanto nos CCELIs, também se verificou correlação negativa entre CLIC4c e p53, assim como entre CLIC4c e TGF-β (p<0.05). Alteração do CLIC4 do núcleo para o citoplasma e alterações na expressão de p53, TGF-β, TNF-α, e α-SMA estão envolvidas na carcinogênese labial.

Humans , Lip Neoplasms , Transforming Growth Factor beta , Tumor Suppressor Protein p53 , Tumor Necrosis Factor-alpha , Chloride Channels , Myofibroblasts , Carcinogenesis , Lip
Article in Korean | WPRIM | ID: wpr-785354


Cystic fibrosis (CF) is an autosomal recessive disease caused by mutations in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR). These mutations alter the synthesis, processing, function, or half-life of CFTR, the main chloride channel expressed in the apical membrane of epithelial cells in the airway, intestine, pancreas, and reproductive tract. Lung disease is the most critical manifestation of CF. It is characterized by airway obstruction, infection, and inflammation that lead to fatal tissue destruction, which causes most CF morbidity and mortality. This article reviews the pathophysiology of CF, recent animal models, and current treatment of CF.

Airway Obstruction , Chloride Channels , Cystic Fibrosis Transmembrane Conductance Regulator , Cystic Fibrosis , Epithelial Cells , Epithelial Sodium Channels , Half-Life , Inflammation , Intestines , Lung Diseases , Lung , Membranes , Models, Animal , Mortality , Pancreas
Article in Chinese | WPRIM | ID: wpr-826529


Bartter syndrome is an inherited metabolic disorder characterized by hypokalemic alkalosis and high rennin-angiotensin-aldosteronism which can occur at all ages but mainly in childhood. Classical Bartter syndrome is caused by loss-of-function variants in the gene encoding basolateral chloride channel ClC-Kb (CLCNKB), which is a common type of Bartter syndrome characterized with diverse clinical manifestations ranging from severe to very mild. This article reviews the function and mechanism of CLCNKB variants in Chinese population and the genotype-phenotype correlation of CLCNKB variants in classical Bartter syndrome.

Asian Continental Ancestry Group , Bartter Syndrome , Genetics , Pathology , Chloride Channels , Genetics , Genetic Association Studies , Humans , Research
Medicina (B.Aires) ; 79(4): 303-314, ago. 2019. ilus, tab
Article in Spanish | LILACS | ID: biblio-1040528


Los canales de cloruros, de sodio, de bicarbonato y los de agua (aquaporinas) se coordinan para mantener la cubierta líquido superficial de las vías respiratorias, que es necesaria para el aclaramiento mucociliar. El mecanismo general para el transporte de electrolitos y agua depende principalmente de la expresión diferencial y distribución de los transportadores y bombas de iones. Los iones y el agua se mueven a través de las vía paracelular o transcelular. La ruta transcelular del transporte de electrolitos requiere un transporte activo (dependiente de ATP) o pasivo (siguiendo gradientes electroquímicos) de iones. La ruta paracelular es un proceso pasivo que está controlado, en última instancia, por los gradientes electroquímicos transepiteliales predominantes. La fibrosis quística es una enfermedad hereditaria que se produce por mutaciones en el gen que codifica la proteína reguladora de la conductibilidad transmembrana de la fibrosis quística (CFTR) que actúa como un canal de cloro y cumple funciones de hidratación del líquido periciliar y mantenimiento del pH luminal. La disfunción del canal de cloro en el epitelio respiratorio determina una alteración en las secreciones bronquiales, con aumento de su viscosidad y alteración de la depuración mucociliar y que asociado a procesos infecciosos puede conducir a daño pulmonar irreversible. La disfunción del CFTR, también se ha visto implicado en la patogénesis de la pancreatitis aguda, en la enfermedad pulmonar obstructiva crónica y la hiperreactividad en el asma. Existen fármacos que aprovechan los mecanismos fisiológicos en el transporte de iones, con un objetivo terapéutico.

The chloride channels, sodium and bicarbonate channels, and aquaporin water channels are coordinated to maintain the airway surface liquid that is necessary for mucociliary clearance. The general mechanism for the transport of electrolytes and fluids depends mainly on the differential expression and distribution of ion transporters and pumps. Ions and water move through the paracellular or transcellular pathways. The transcellular route of electrolyte transport requires an active transport (dependent on ATP) or passive (following electrochemical gradients) of ions. The paracellular pathway is a passive process that is ultimately controlled by the predominant transepithelial electrochemical gradients. Cystic fibrosis is a hereditary disease that is produced by mutations in the gene that encode cystic fibrosis transmembrane conductance regulatory protein (CFTR) that acts as a chloride channel and performs functions of hydration of periciliary fluid and maintenance of luminal pH. The dysfunction of the chlorine channel in the respiratory epithelium determines an alteration in the bronchial secretions, with an increase in its viscosity and alteration of the mucociliary clearance and that associated with infectious processes can lead to irreversible lung damage. CFTR dysfunction has also been implicated in the pathogenesis of acute pancreatitis, chronic obstructive pulmonary disease, and bronchial hyperreactivity in asthma. There are drugs that exploit physiological mechanisms in the transport of ions with a therapeutic objective.

Humans , Biological Transport, Active/physiology , Mucociliary Clearance/physiology , Ion Transport/physiology , Chloride Channels/metabolism , Cystic Fibrosis Transmembrane Conductance Regulator/metabolism , Cystic Fibrosis/metabolism , Chloride Channels/physiology , Cystic Fibrosis Transmembrane Conductance Regulator/physiology , Cystic Fibrosis/physiopathology
Acta Physiologica Sinica ; (6): 555-561, 2019.
Article in Chinese | WPRIM | ID: wpr-777156


The aim of the present study was to establish a cell model of volume-regulated anion channel subunit LRRC8A and investigate the physiological characteristics of LRRC8A. The eukaryotic expression vectors of LRRC8A and YFP-H148Q/I152L were constructed and transfected into Fischer rat thyroid (FRT) cells by Lipofectamine 2000. The FRT cell lines co-expressing LRRC8A and YFP-H148Q/I152L were obtained by antibiotic screening. The expression of LRRC8A and YFP-H148Q/I152L in FRT cells was detected by the inverted fluorescence microscope. The fluorescence quenching kinetic experiment was done to verify the function and effectiveness of the cell model. Then the cell model was utilized to study the physiological characteristics of LRRC8A, such as the characteristics of anion transport, the opening of LRRC8A by osmotic pressure, the effect of anion transport velocity, and the effect of chloride channel inhibitors on LRRC8A anion channel. The results of the inverted fluorescence microscope showed that LRRC8A was expressed on the cell membrane and YFP-H148Q/I152L was expressed in the cytoplasm. The results of fluorescence quenching kinetic test showed that under the condition of low osmotic state, LRRC8A could transport some kinds of anions, such as iodine and chloride ions. Osmotic pressure played a key role in the regulation of LRRC8A volume-regulated anion channel opening. Chloride channel inhibitors inhibited ion transport of LRRC8A channel in a dose-dependent manner. It is suggested that LRRC8A has the characteristics of classic volume-regulated anion channels by using the cell model of FRT cells co-expressing LRRC8A and YFP-H148Q/I152L.

Animals , Anions , Cells, Cultured , Chloride Channels , Ion Transport , Membrane Proteins , Physiology , Microscopy, Fluorescence , Rats , Rats, Inbred F344 , Thyroid Gland , Cell Biology , Transfection
Experimental Neurobiology ; : 658-669, 2019.
Article in English | WPRIM | ID: wpr-785791


Anoctamin1 (ANO1) also known as TMEM16A is a transmembrane protein that functions as a Ca²⁺ activated chloride channel. Recently, the structure determination of a fungal Nectria haematococca TMEM16 (nhTMEM16) scramblase by X-ray crystallography and a mouse ANO1 by cryo-electron microscopy has provided the insight in molecular architecture underlying phospholipid scrambling and Ca²⁺ binding. Because the Ca²⁺ binding motif is embedded inside channel protein according to defined structure, it is still unclear how intracellular Ca²⁺ moves to its deep binding pocket effectively. Here we show that EF-hand like region containing multiple acidic amino acids at the N-terminus of ANO1 is a putative site regulating the activity of ANO1 by Ca²⁺ and voltage. The EF-hand like region of ANO1 is highly homologous to the canonical EF hand loop in calmodulin that contains acidic residues in key Ca²⁺-coordinating positions in the canonical EF hand. Indeed, deletion and Ala-substituted mutation of this region resulted in a significant reduction in the response to Ca²⁺ and changes in its key biophysical properties evoked by voltage pulses. Furthermore, only ANO1 and ANO2, and not the other TMEM16 isoforms, contain the EF-hand like region and are activated by Ca²⁺. Moreover, the molecular modeling analysis supports that EF-hand like region could play a key role during Ca²⁺ transfer. Therefore, these findings suggest that EF-hand like region in ANO1 coordinates with Ca²⁺ and modulate the activation by Ca²⁺ and voltage.

Amino Acids, Acidic , Animals , Calcium , Calmodulin , Chloride Channels , Cryoelectron Microscopy , Crystallography, X-Ray , EF Hand Motifs , Mice , Models, Molecular , Mutagenesis , Nectria , Protein Isoforms
Article in English | WPRIM | ID: wpr-765965


BACKGROUND/AIMS: Interstitial cells play important roles in gastrointestinal (GI) neuro-smooth muscle transmission. The underlying mechanisms of colonic dysmotility have not been well illustrated. We established a partial colon obstruction (PCO) mouse model to investigate the changes of interstitial cells and the correlation with colonic motility. METHODS: Western blot technique was employed to observe the protein expressions of Kit, platelet-derived growth factor receptor-α (Pdgfra), Ca²⁺-activated Cl⁻ (Ano1) channels, and small conductance Ca²⁺- activated K⁺ (SK) channels. Colonic migrating motor complexes (CMMCs) and isometric force measurements were employed in control mice and PCO mice. RESULTS: PCO mice showed distended abdomen and feces excretion was significantly reduced. Anatomically, the colon above the obstructive silicone ring was obviously dilated. Kit and Ano1 proteins in the colonic smooth muscle layer of the PCO colons were significantly decreased, while the expression of Pdgfra and SK3 proteins were significantly increased. The effects of a nitric oxide synthase inhibitor (L-NAME) and an Ano1 channel inhibitor (NPPB) on CMMC and colonic spontaneous contractions were decreased in the proximal and distal colons of PCO mice. The SK agonist, CyPPA and antagonist, apamin in PCO mice showed more effect to the CMMCs and colonic smooth muscle contractions. CONCLUSIONS: Colonic transit disorder may be due to the downregulation of the Kit and Ano1 channels and the upregulation of SK3 channels in platelet-derived growth factor receptor-α positive (PDGFRα⁺) cells. The imbalance between interstitial cells of Cajal-Ano1 and PDGFRα-SK3 distribution might be a potential reason for the colonic dysmotility.

Abdomen , Animals , Apamin , Blotting, Western , Chloride Channels , Colon , Down-Regulation , Feces , Interstitial Cells of Cajal , Mice , Muscle, Smooth , Myoelectric Complex, Migrating , Nitric Oxide Synthase , Platelet-Derived Growth Factor , Silicon , Silicones , Small-Conductance Calcium-Activated Potassium Channels , Up-Regulation
Article in English | WPRIM | ID: wpr-765928


BACKGROUND/AIMS: Interstitial cells of Cajal (ICC) and their special calcium-activated chloride channel, anoctamin-1 (ANO1) play pivotal roles in regulating colonic transit. This study is designed to investigate the role of ICC and the ANO1 channel in colonic transit disorder in dextran sodium sulfate (DSS)-treated colitis mice. METHODS: Colonic transit experiment, colonic migrating motor complexes (CMMCs), smooth muscle spontaneous contractile experiments, intracellular electrical recordings, western blotting analysis, and quantitative polymerase chain reaction were applied in this study. RESULTS: The mRNA and protein expressions of c-KIT and ANO1 channels were significantly decreased in the colons of DSS-colitis mice. The colonic artificial fecal-pellet transit experiment in vitro was significantly delayed in DSS-colitis mice. The CMMCs and smooth muscle spontaneous contractions were significantly decreased by 5-nitro-2-(3-phenylpropylamino)benzoic acid (NPPB), an ANO1 channel blocker, and NG-Nitro-L-arginine methyl ester hydrochloride (L-NAME), an inhibitor of nitric oxide synthase activity, in DSS-colitis mice compared with that of control mice. Intracellular electrical recordings showed that the amplitude of NPPB-induced hyperpolarization was more positive in DSS-colitis mice. The electric field stimulation-elicited nitric-dependent slow inhibitory junctional potentials were also more positive in DSS-colitis mice than those of control mice. CONCLUSION: The results suggest that colonic transit disorder is mediated via downregulation of the nitric oxide/ICC/ANO1 signalling pathway in DSS-colitis mice.

Animals , Blotting, Western , Chloride Channels , Colitis , Colon , Dextrans , Down-Regulation , In Vitro Techniques , Interstitial Cells of Cajal , Mice , Muscle, Smooth , Myoelectric Complex, Migrating , NG-Nitroarginine Methyl Ester , Nitric Oxide Synthase , Polymerase Chain Reaction , RNA, Messenger , Sodium
Article in English | WPRIM | ID: wpr-761809


Anoctamin 5 (ANO5)/TMEM16E belongs to a member of the ANO/TMEM16 family member of anion channels. However, it is a matter of debate whether ANO5 functions as a genuine plasma membrane chloride channel. It has been recognized that mutations in the ANO5 gene cause many skeletal muscle diseases such as limb girdle muscular dystrophy type 2L (LGMD2L) and Miyoshi muscular dystrophy type 3 (MMD3) in human. However, the molecular mechanisms of the skeletal myopathies caused by ANO5 defects are poorly understood. To understand the role of ANO5 in skeletal muscle development and function, we silenced the ANO5 gene in C2C12 myoblasts and evaluated whether it impairs myogenesis and myotube function. ANO5 knockdown (ANO5-KD) by shRNA resulted in clustered or aggregated nuclei at the body of myotubes without affecting differentiation or myotube formation. Nuclear positioning defect of ANO5-KD myotubes was accompanied with reduced expression of Kif5b protein, a kinesin-related motor protein that controls nuclear transport during myogenesis. ANO5-KD impaired depolarization-induced [Ca²⁺]i transient and reduced sarcoplasmic reticulum (SR) Ca²⁺ storage. ANO5-KD resulted in reduced protein expression of the dihydropyridine receptor (DHPR) and SR Ca²⁺-ATPase subtype 1. In addition, ANO5-KD compromised co-localization between DHPR and ryanodine receptor subtype 1. It is concluded that ANO5-KD causes nuclear positioning defect by reduction of Kif5b expression, and compromises Ca²⁺ signaling by downregulating the expression of DHPR and SERCA proteins.

Active Transport, Cell Nucleus , Calcium Channels, L-Type , Cell Membrane , Chloride Channels , Humans , Muscle Development , Muscle Fibers, Skeletal , Muscle, Skeletal , Muscular Diseases , Muscular Dystrophies , Muscular Dystrophies, Limb-Girdle , Myoblasts , RNA, Small Interfering , Ryanodine Receptor Calcium Release Channel , Sarcoplasmic Reticulum
Article in English | WPRIM | ID: wpr-765101


BACKGROUND: Tetrabromobisphenol A (TBBPA), one of the most widely used brominated flame-retardants, is a representative persistent organic pollutants group. Studies on TBBPA toxicity have been conducted using various target cells; however, few studies have investigated TBBPA toxicity in bone cells. Therefore, this study investigated the in vitro effects of TBBPA on osteoclasts, a cell type involved in bone metabolism. METHODS: RAW264.7 cells were cultured in medium containing 50 ng/mL receptor activator of nuclear factor kappa B ligand (RANKL) and varying concentrations of TBBPA. To evaluate the effects of TBBPA on the differentiation and function of osteoclasts, osteoclast-specific gene expression, tartrate-resistant acid phosphatase (TRAP) activity, bone resorbing activity, mitochondrial membrane potential (MMP) and mitochondrial superoxide were measured. RESULTS: The presence of 20 μM TBBPA significantly increased TRAP activity in RANKL-stimulated RAW264.7 cells, the bone resorbing activity of osteoclasts, and the gene expression of Akt2, nuclear factor of activated T-cells cytoplasmic 1, and chloride channel voltage-sensitive 7. However, TBBPA treatment caused no change in the expression of carbonic anhydrase II, cathepsin K, osteopetrosis-associated transmembrane protein 1, Src, extracellular signal-related kinase, GAB2, c-Fos, or matrix metalloproteinase 9. Furthermore, 20 μM TBBPA caused a significant decrease in MMP and a significant increase in mitochondrial superoxide production. CONCLUSION: This study suggests that TBBPA promotes osteoclast differentiation and activity. The mechanism of TBBPA-stimulated osteoclastogenesis might include increased expression of several genes involved in osteoclast differentiation and reactive oxygen species production.

Acid Phosphatase , Carbonic Anhydrase II , Cathepsin K , Chloride Channels , Cytoplasm , Gene Expression , In Vitro Techniques , Matrix Metalloproteinase 9 , Membrane Potential, Mitochondrial , Metabolism , Osteoclasts , Phosphotransferases , RANK Ligand , Reactive Oxygen Species , Receptor Activator of Nuclear Factor-kappa B , Superoxides , T-Lymphocytes
Arch. argent. pediatr ; 116(3): 442-444, jun. 2018. ilus
Article in English, Spanish | LILACS, BINACIS | ID: biblio-950023


La enfermedad de Dent es una tubulopatía recesiva ligada al cromosoma X caracterizada por proteinuria de bajo peso molecular (bpm), hipercalciuria, nefrocalcinosis o nefrolitiasis, disfunción tubular proximal e insuficiencia renal en la adultez. Las mujeres son portadoras y, en general, padecen una forma leve de la enfermedad. La progresión hacia la insuficiencia renal en estadio terminal se da entre los 30 y los 50 años de edad en el 30-80% de los varones afectados. A falta de un tratamiento dirigido al defecto molecular, en la actualidad, los pacientes con enfermedad de Dent reciben tratamientos complementarios orientados a prevenir la nefrolitiasis y la nefrocalcinosis. El caso que presentamos es el de un niño de 11 años con nefrocalcinosis y nefrolitiasis, en quien se detectó una nueva mutación en el gen CLCN5.

Dent's disease is a rare X-linked recessive tubulopathy characterized by low molecular weight (LMW) proteinuria, hypercalciuria, nephrolcalcinosis or nephrolithiasis, proximal tubular dysfunction and renal failure in adulthood. Females are carriers and usually mildly affected. Progression to endstage renal failure are at the 3rd-5th decades of life in 30-80% of affected males. In the absence of therapy targeting for the molecular defect, the current care of patients with Dent's disease is supportive, focusing on the prevention of nephrolithiasis and nephrocalcinosis. We present an 11-year-old child with nephrocalcinosis and nephrolithiasis caused by a new mutation at CLCN5 gene.

Humans , Male , Child , Chloride Channels/genetics , Nephrolithiasis/etiology , Dent Disease/genetics , Nephrocalcinosis/etiology , Nephrolithiasis/genetics , Dent Disease/physiopathology , Mutation , Nephrocalcinosis/genetics
Chinese Journal of Applied Physiology ; (6): 441-444 449, 2018.
Article in Chinese | WPRIM | ID: wpr-773764


OBJECTIVE@#To observe the effects of blocking and activating chloride channels on hemolysis induced by puerarin injection in rabbits and to investigate the roles of chloride channels in hemolytic reaction induced by puerarin injection.@*METHODS@#Rabbit erythrocyte suspension was incubated with different concentrations of puerarin injection(0.75, 1.5, 3, 6, 12 mg/ml) at 37C for 6 hours. The cell imaging system was employed to observe whether puerarin injection induced hemolysis. The hemolysis rate was detected by microplate reader and flow cytometry. Effects of activating and closing chloride channels on the hemolysis induced by puerarin injection were explored.@*RESULTS@#Puerarin injection could induce the hemolysis of rabbit erythrocytes . In the range of 1.5 mg/ml~12 mg/ml, puerarin injection could induce hemolysis in a concentration-dependent manner (=3, <0.01). The chloride channel blockers tamoxifen (20 μmol/L) and ATP (10 mmol/L) significantly inhibited the hemolysis induced by puerarin injection (=3~5, <0.01). Application of low concentration ATP (50 μmol/L) to activate the chloride channel significantly increased puerarin injection induced hemolysis (=4, <0.01).@*CONCLUSIONS@#The hemolytic effect of puerarin injection is dose-dependent , and the activation of chloride channel is closely related to the hemolysis induced by puerarin injection.

Animals , Chloride Channels , Erythrocytes , Hemolysis , Isoflavones , Rabbits
Journal of Breast Cancer ; : 103-111, 2018.
Article in English | WPRIM | ID: wpr-714871


PURPOSE: Chloride channel-3 (ClC-3) is a member of the chloride channel family and plays a critical role in a variety of cellular activities. The aim of the present study is to explore the molecular mechanisms underlying the antitumor effect of silencing ClC-3 in breast cancer. METHODS: Human breast cancer cell lines MDA-MB-231 and MCF-7 were used in the experiments. Messenger RNA and protein expression were examined by quantitative real-time polymerase chain reaction and western blot analysis. Cell proliferation was measured by the bromodeoxyuridine method, and the cell cycle was evaluated using fluorescence-activated cell sorting. Protein interaction in cells was analyzed by co-immunoprecipitation. Tumor tissues were stained with hematoxylin-eosin and tumor burden was measured using the Metamorph software. RESULTS: Breast cancer tissues collected from patients showed an increase in ClC-3 expression. Knockdown of ClC-3 inhibited the secretion of insulin-like growth factor (IGF)-1, cell proliferation, and G1/S transition in breast cancer cells. In the mouse xenograft model of human breast carcinoma, tumor growth was significantly slower in animals injected with ClC-3-deficient cells compared with the growth of normal human breast cancer cells. In addition, silencing of ClC-3 attenuated the expression of proliferating cell nuclear antigen, Ki-67, cyclin D1, and cyclin E, as well as the activation of extracellular signal-regulated protein kinases (ERK) 1/2, both in vitro and in vivo. CONCLUSION: Together, our data suggest that upregulation of ClC-3 by IGF-1 contributes to cell proliferation and tumor growth in breast cancer, and ClC-3 deficiency suppresses cell proliferation and tumor growth via the IGF/IGF receptor/ERK pathway.

Animals , Blotting, Western , Breast Neoplasms , Breast , Bromodeoxyuridine , Cell Cycle , Cell Line , Cell Proliferation , Chloride Channels , Cyclin D1 , Cyclin E , Cyclins , Flow Cytometry , Heterografts , Humans , Immunoprecipitation , In Vitro Techniques , Insulin-Like Growth Factor I , Methods , Mice , Proliferating Cell Nuclear Antigen , Protein Kinases , Real-Time Polymerase Chain Reaction , RNA, Messenger , Tumor Burden , Up-Regulation
Article in Korean | WPRIM | ID: wpr-107259


Chronic constipation is one of the most common digestive diseases frequently observed in a clinical setting. It has been known to cause considerable damage to the quality of life of patients. Despite recent developments, there are considerable limitations in the use of constipation-modulating agents in Korea. Chloride channel inhibitors, such as lubiprostone and linaclotide, have not been introduced in Korea yet, and prucalopride and several kinds of polyethylene glycol are not covered under medical insurance. This article assesses medicines that are clinically available for the management of constipation in Korea, with a brief review of agents that have recently developed around the world.

Chloride Channels , Constipation , Drug Therapy , Humans , Insurance , Korea , Lubiprostone , Polyethylene Glycols , Quality of Life
Article in English | WPRIM | ID: wpr-764776


Calcium has versatile roles in diverse physiological functions. Among these functions, intracellular Ca²⁺ plays a key role during the secretion of salivary glands. In this review, we introduce the diverse cellular components involved in the saliva secretion and related dynamic intracellular Ca²⁺ signals. Calcium acts as a critical second messenger for channel activation, protein translocation, and volume regulation, which are essential events for achieving the salivary secretion. In the secretory process, Ca²⁺ activates K⁺ and Cl⁻ channels to transport water and electrolyte constituting whole saliva. We also focus on the Ca²⁺ signals from intracellular stores with discussion about detailed molecular mechanism underlying the generation of characteristic Ca²⁺ patterns. In particular, inositol triphosphate signal is a main trigger for inducing Ca²⁺ signals required for the salivary gland functions. The biphasic response of inositol triphosphate receptor and Ca²⁺ pumps generate a self-limiting pattern of Ca²⁺ efflux, resulting in Ca²⁺ oscillations. The regenerative Ca²⁺ oscillations have been detected in salivary gland cells, but the exact mechanism and function of the signals need to be elucidated. In future, we expect that further investigations will be performed toward better understanding of the spatiotemporal role of Ca²⁺ signals in regulating salivary secretion.

Calcium Signaling , Calcium , Chloride Channels , Inositol , Inositol 1,4,5-Trisphosphate Receptors , Protein Transport , Saliva , Salivary Glands , Salivation , Second Messenger Systems , Secretory Pathway , Water
Article in English | WPRIM | ID: wpr-728768


Myotonia congenita (MC) is a genetic disease that displays impaired relaxation of skeletal muscle and muscle hypertrophy. This disease is mainly caused by mutations of CLCN1 that encodes human skeletal muscle chloride channel (CLC-1). CLC-1 is a voltage gated chloride channel that activates upon depolarizing potentials and play a major role in stabilization of resting membrane potentials in skeletal muscle. In this study, we report 4 unrelated Korean patients diagnosed with myotonia congenita and their clinical features. Sequence analysis of all coding regions of the patients was performed and mutation, R47W and A298T, was commonly identified. The patients commonly displayed transient muscle weakness and only one patient was diagnosed with autosomal dominant type of myotonia congenita. To investigate the pathological role of the mutation, electrophysiological analysis was also performed in HEK 293 cells transiently expressing homo- or heterodimeric mutant channels. The mutant channels displayed reduced chloride current density and altered channel gating. However, the effect of A298T on channel gating was reduced with the presence of R47W in the same allele. This analysis suggests that impaired CLC-1 channel function can cause myotonia congenita and that R47W has a protective effect on A298T in relation to channel gating. Our results provide clinical features of Korean myotonia congenita patients who have the heterozygous mutation and reveal underlying pathophyological consequences of the mutants by taking electrophysiological approach.

Alleles , Chloride Channels , Clinical Coding , Electrophysiology , HEK293 Cells , Humans , Hypertrophy , Membrane Potentials , Muscle Weakness , Muscle, Skeletal , Myotonia Congenita , Myotonia , Relaxation , Sequence Analysis
IBJ-Iranian Biomedical Journal. 2017; 21 (5): 342-346
in English | IMEMR | ID: emr-188492


Background: Chloride channels have already been over-expressed in the different types of cancer. Chlorotoxins, as the blocking agent of these channels, have been indicated to be an effective drug against tumors. In this study, we characterized a putative chlorotoxin from a cDNA library of the venom glands obtained from the Iranian scorpion Odontobuthus doriae

Methods: A cDNA library was constructed from venom gland transcriptome of six scorpions. The cDNA encoding Odontobuthus doriae chlorotoxin was isolated from the library, and its putative peptide was characterized by some bioinformatics software such as protein blast, SignalP4.0, DISULFIND and Clustal Omega

Results: The mature Odontobuthus doriae chlorotoxin peptide has a 35-amino-acid residue and four disulfide bounds. This putative chlorotoxin is a small, compact, and stable molecule. Moreover, based on the open reading frame sequence similarity, this peptide is similar to Buthus martensii Karsch chlorotoxin-like toxin and Bml2-b neurotoxins from the Chinese scorpion Mesobuthus martensii

Conclusion: The small size of this putative chlorotoxin and its stability make it as a suitable candidate for medical and pharmacological research, especially in the cancer research

Chloride Channels , Transcriptome , Neoplasms/drug therapy , Gene Library , Biodiversity
Article in Korean | WPRIM | ID: wpr-65864


Myotonia congenita (MC) is a hereditary disease of the chloride channels of skeletal muscle caused by mutation of CLCN1. It characteristically manifests as delayed relaxation of the skeletal muscle or myotonia. It has a wide phenotypic variability, ranging from asymptomatic to severe disability. However, it is uncommon for a phenotypic difference to appear within a family. We report the first Korean family with the p.A313T mutation exhibiting marked phenotypic variability.

Chloride Channels , Genetic Diseases, Inborn , Humans , Muscle, Skeletal , Myotonia Congenita , Myotonia , Relaxation
Article in English | WPRIM | ID: wpr-285258


Swelling-activated chloride currents (ICl.swell) are thought to play a role in several physiologic and pathophysiologic processes and thus represent a target for therapeutic approaches. However, the mechanism of ICl.swell regulation remains unclear. In this study, we used the whole-cell patch-clamp technique to examine the role of protein kinase C (PKC) in the regulation of ICl.swell in human atrial myocytes. Atrial myocytes were isolated from the right atrial appendages of patients undergoing coronary artery bypass and enzymatically dissociated. ICl.swell was evoked in hypotonic solution and recorded using the whole-cell patch-clamp technique. The PKC agonist phorbol dibutyrate (PDBu) enhanced ICl.swell in a concentration-dependent manner, which was reversed in isotonic solution and by a chloride current inhibitor, 9-anthracenecarboxylicacid. Furthermore, the PKC inhibitor bis-indolylmaleimide attenuated the effect and 4α-PDBu, an inactive PDBu analog, had no effect on ICl.swell. These results, obtained using the whole-cell patch-clamp technique, demonstrate the ability of PKC to activate ICl,swell in human atrial myocytes. This observation was consistent with a previous study using a single-channel patch-clamp technique, but differed from some findings in other species.

Anthracenes , Pharmacology , Chloride Channels , Metabolism , Chlorides , Metabolism , Culture Media , Metabolism , Pharmacology , Dose-Response Relationship, Drug , Evoked Potentials , Physiology , Heart Atria , Cell Biology , Metabolism , Humans , Hypotonic Solutions , Metabolism , Pharmacology , Indoles , Pharmacology , Ion Transport , Maleimides , Pharmacology , Myocytes, Cardiac , Cell Biology , Metabolism , Patch-Clamp Techniques , Phorbol 12,13-Dibutyrate , Pharmacology , Primary Cell Culture , Protein Kinase C , Metabolism
Protein & Cell ; (12): 417-433, 2016.
Article in English | WPRIM | ID: wpr-757122


Microglia play a pivotal role in clearance of Aβ by degrading them in lysosomes, countering amyloid plaque pathogenesis in Alzheimer's disease (AD). Recent evidence suggests that lysosomal dysfunction leads to insufficient elimination of toxic protein aggregates. We tested whether enhancing lysosomal function with transcription factor EB (TFEB), an essential regulator modulating lysosomal pathways, would promote Aβ clearance in microglia. Here we show that microglial expression of TFEB facilitates fibrillar Aβ (fAβ) degradation and reduces deposited amyloid plaques, which are further enhanced by deacetylation of TFEB. Using mass spectrometry analysis, we firstly confirmed acetylation as a previously unreported modification of TFEB and found that SIRT1 directly interacted with and deacetylated TFEB at lysine residue 116. Subsequently, SIRT1 overexpression enhanced lysosomal function and fAβ degradation by upregulating transcriptional levels of TFEB downstream targets, which could be inhibited when TFEB was knocked down. Furthermore, overexpression of deacetylated TFEB at K116R mutant in microglia accelerated intracellular fAβ degradation by stimulating lysosomal biogenesis and greatly reduced the deposited amyloid plaques in the brain slices of APP/PS1 transgenic mice. Our findings reveal that deacetylation of TFEB could regulate lysosomal biogenesis and fAβ degradation, making microglial activation of TFEB a possible strategy for attenuating amyloid plaque deposition in AD.

Alzheimer Disease , Metabolism , Pathology , Amyloid beta-Peptides , Metabolism , Amyloid beta-Protein Precursor , Genetics , Metabolism , Animals , Basic Helix-Loop-Helix Leucine Zipper Transcription Factors , Chemistry , Genetics , Metabolism , Brain , Metabolism , Cells, Cultured , Chloride Channels , Genetics , Metabolism , Disease Models, Animal , HEK293 Cells , Humans , Lysosomes , Genetics , Metabolism , Mice , Mice, Transgenic , Microglia , Cell Biology , Metabolism , Mutagenesis, Site-Directed , Peptides , Chemistry , Protein Binding , RNA Interference , Sirtuin 1 , Genetics , Metabolism