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1.
Braz. j. med. biol. res ; 54(7): e10213, 2021. tab, graf
Article in English | LILACS | ID: biblio-1249312

ABSTRACT

Sevoflurane (SEVO) is widely applied as an anesthetic, which exerts antitumor capacity in various cancers, including hepatocellular carcinoma (HCC). Previous studies indicated that long non-coding RNA KCNQ1 opposite strand/antisense transcript 1 (KCNQ1OT1) was upregulated, while microRNA-29a-3p (miR-29a-3p) was downregulated in HCC. Thus, we aimed to explore the roles of KCNQ1OT1 and miR-29a-3p in HCC cells exposed to SEVO. Cell proliferation, apoptosis, migration, and invasion were assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, flow cytometry, and transwell assays, respectively. The levels of genes were determined by quantitative real-time polymerase chain reaction (qRT-PCR) or western blot. Furthermore, the interaction between miR-29a-3p and KCNQ1OT1 or chromebox protein homolog 3 (CBX3) was predicted by Starbase or Targetscan, and then confirmed by dual-luciferase reporter assay. We found that the levels of KCNQ1OT1 and CBX3 were decreased, while miR-29a-3p was increased in SEVO-treated HCC cells. KCNQ1OT1 overexpression weakened the inhibitory effects of SEVO on HCC cell proliferation, apoptosis, migration, and invasion. Interestingly, KCNQ1OT1 bound to miR-29a-3p, and miR-29a-3p targeted CBX3. KCNQ1OT1 upregulated CBX3 level by repressing miR-29a-3p expression. Furthermore, KCNQ1OT1 exerted tumor promotion in HCC cells via suppressing miR-29a-3p to regulate CBX3 expression. Collectively, our findings demonstrated that KCNQ1OT1 regulated the antitumor effects of SEVO on HCC cells through modulating the miR-29a-3p/CBX3 axis, providing a theoretical basis for the treatment of HCC.


Subject(s)
Humans , Carcinoma, Hepatocellular/genetics , Carcinoma, Hepatocellular/drug therapy , Potassium Channels, Voltage-Gated , MicroRNAs/genetics , Liver Neoplasms/genetics , Liver Neoplasms/drug therapy , Chromosomal Proteins, Non-Histone , RNA, Long Noncoding/genetics , Sevoflurane/pharmacology
2.
Article in English | WPRIM | ID: wpr-921372

ABSTRACT

OBJECTIVES@#This study aims to explore the effect and molecular mechanism of long non-coding RNA (lncRNA) potassium voltage-gated channel subfamily Q member 1 overlapping transcript 1 (KCNQ1OT1) on proliferation and osteogenic differentiation in human periodontal ligament stem cells (hPDLSCs).@*METHODS@#The hPDLSCs of normal periodontal tissues were isolated and cultured. The mineralized solution induced the osteoblast differentiation of hPDLSCs. The down-regulation of lncRNA KCNQ1OT1, the overexpression of anti-miR-24-3p on the proliferation and the levels of osteocalcin (OCN), osteopontin (OPN) and alkaline phosphatase (ALP) of hPDLSCs were investigated. Real-time quantitative polymerase chain reaction (RT-qPCR) was used to detect the levels of lncRNA KCNQ1OT1, miR-24-3p, OCN, OPN, and ALP. Methyl thiazolyl tetrazolium (MTT) method was used to detect cell viability and activity. Cell proliferation was evaluated by MTT. Western blot was used to detect protein expression. The targeted relationship between lncRNA KCNQ1OT1 and miR-24-3p was detected by double-luciferase experiment.@*RESULTS@#The expression level of lncRNA KCNQ1OT1 increased, and that of miR-24-3p decreased during the osteogenesis of hPDLSCs (@*CONCLUSIONS@#Down-regulation of lncRNA KCNQ1OT1 inhibited the proliferation and osteogenic differentiation of hPDLSCs by targeting the up-regulated expression of miR-24-3p.


Subject(s)
Cell Differentiation , Cell Proliferation , Humans , MicroRNAs/genetics , Osteogenesis , Periodontal Ligament/cytology , Potassium , Potassium Channels, Voltage-Gated , RNA, Long Noncoding/genetics , Stem Cells/cytology
3.
Article in Chinese | WPRIM | ID: wpr-879269

ABSTRACT

As a noninvasive neuromodulation technique, transcranial magnetic stimulation (TMS) is widely used in the clinical treatment of neurological and psychiatric diseases, but the mechanism of its action is still unclear. The purpose of this paper is to investigate the effects of different frequencies of magnetic stimulation (MS) on neuronal excitability and voltage-gated potassium channels in the


Subject(s)
Action Potentials , Animals , Magnetic Phenomena , Mental Disorders , Mice , Neurons , Patch-Clamp Techniques , Potassium Channels, Voltage-Gated
4.
Acta Physiologica Sinica ; (6): 217-222, 2021.
Article in English | WPRIM | ID: wpr-878250

ABSTRACT

Accumulating evidence demonstrates that the nucleus tractus solitarii (NTS) neurons serve as central respiratory chemoreceptors, but the underlying molecular mechanisms remain undefined. The present study investigated the expression of acid-sensitive ether-à-go-go-gene-like (Elk, Kv12) channels in the NTS of mice. Immunofluorescence staining was used to observe the distribution and cellular localization of the Kv12 channels in NTS neurons. Western blot and quantitative real-time PCR (qPCR) were used to evaluate protein and mRNA expression levels of Kv12 channels. The results showed that all of the three members (Kv12.1, Kv12.2, Kv12.3) of the Kv12 channel family were expressed in NTS neurons, and their expressions were co-localized with paired-like homeobox 2b gene (Phox2b) expression. The expression of Kv12.1 mRNA was the largest, whereas the expression of Kv12.3 was the least in the NTS. The results suggest Kv12 channels are expressed in Phox2b-expressing neurons in the NTS of mice, which provides molecular evidence for pH sensitivity in Phox2b-expressing NTS neurons.


Subject(s)
Animals , Mice , Neurons , Potassium Channels, Voltage-Gated , Solitary Nucleus , Transcription Factors/genetics
5.
Article in English | WPRIM | ID: wpr-716768

ABSTRACT

PURPOSE: Abnormal potassium channels expression affects vessel function, including vascular tone and proliferation rate. Diverse potassium channels, including voltage-gated potassium (Kv) channels, are involved in pathological changes of pulmonary arterial hypertension (PAH). Since the role of the Kv1.7 channel in PAH has not been previously studied, we investigated whether Kv1.7 channel expression changes in the lung tissue of a monocrotaline (MCT)-induced PAH rat model and whether this change is influenced by the endothelin (ET)-1 and reactive oxygen species (ROS) pathways. METHODS: Rats were separated into 2 groups: the control (C) group and the MCT (M) group (60 mg/kg MCT). A hemodynamic study was performed by catheterization into the external jugular vein to estimate the right ventricular pressure (RVP), and pathological changes in the lung tissue were investigated. Changes in protein and mRNA levels were confirmed by western blot and polymerase chain reaction analysis, respectively. RESULTS: MCT caused increased RVP, medial wall thickening of the pulmonary arterioles, and increased expression level of ET-1, ET receptor A, and NADPH oxidase (NOX) 4 proteins. Decreased Kv1.7 channel expression was detected in the lung tissue. Inward-rectifier channel 6.1 expression in the lung tissue also increased. We confirmed that ET-1 increased NOX4 level and decreased glutathione peroxidase-1 level in pulmonary artery smooth muscle cells (PASMCs). ET-1 increased ROS level in PASMCs. CONCLUSION: Decreased Kv1.7 channel expression might be caused by the ET-1 and ROS pathways and contributes to MCT-induced PAH.


Subject(s)
Animals , Arterioles , Blotting, Western , Catheterization , Catheters , Endothelins , Glutathione , Hemodynamics , Hypertension , Jugular Veins , Lung , Models, Animal , Monocrotaline , Myocytes, Smooth Muscle , NADPH Oxidases , Polymerase Chain Reaction , Potassium , Potassium Channels , Potassium Channels, Voltage-Gated , Pulmonary Artery , Rats , Reactive Oxygen Species , RNA, Messenger , Ventricular Pressure
6.
Article in Chinese | WPRIM | ID: wpr-690933

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the expression of LncRNA KCNQ1OT1 in patients with acute myeloid leukemia (AML) and to analyze the relation of LncRNA KCNQ1OT1 expression levels with clinicopathological features.</p><p><b>METHODS</b>A total of 68 patients with AML were enrolled in the study, 48 out of them were suffered from acute myeloid leukemia (AML) and 20 reached to complete remission (CR), 30 age-matched patients with iron-deficient anemia were included in control group, the peripheral blood samples of all the patients were collected, and the real-time fluorescent quantitative PCR (qRT-PCR) was used to detect the expression of LncRNA KCNQ1OT1, meanwhile, the correlation of its expression with clinicopathological characteristics and prognosis was analyzed.</p><p><b>RESULTS</b>The expression of LncRNA KCNQ1OT1 in AML patients was significantly higher than that in the patient with complete remission and iron-deficient anemia (F=14.67, P<0.01). The expression of LncRNA KCNQ1OT1 was not significantly different between 20 cases of AML-CR and 30 cases of iron-deficient anemia (P>0.05). The expression of LncRNA KCNQ1OT1 was associated with NCCN risk grade and survival status in patients with AML. The median overall survival time was significantly shorter in patients with high expression of LncRNA KCNQ1OT1 than that in patients with low expression(P<0.05).</p><p><b>CONCLUSION</b>LncRNA KCNQ1OT1 may be involved in the regulation of AML. Expression of LncRNA KCNQ1OT1 and NCCN risk score can be used as biomarkers of prognosis in the patients with AML and may be a potential prognostic marker and therapeutic target for AML patients.</p>


Subject(s)
Humans , Leukemia, Myeloid, Acute , Potassium Channels, Voltage-Gated , Prognosis , RNA, Long Noncoding , Remission Induction
7.
Braz. j. med. biol. res ; 50(9): e5765, 2017. tab, graf
Article in English | LILACS | ID: biblio-888990

ABSTRACT

Clobenzorex is a metabolic precursor of amphetamine indicated for the treatment of obesity. Amphetamines have been involved with cardiovascular side effects such as hypertension and pulmonary arterial hypertension. The aim of the present study was to investigate whether the direct application of 10-9-10-5 M clobenzorex on isolated phenylephrine-precontracted rat aortic rings produces vascular effects, and if so, what mechanisms may be involved. Clobenzorex produced an immediate concentration-dependent vasorelaxant effect at the higher concentrations (10-7.5-10-5 M). The present outcome was not modified by 10-6 M atropine (an antagonist of muscarinic acetylcholine receptors), 3.1×10-7 M glibenclamide (an ATP-sensitive K+ channel blocker), 10-3 M 4-aminopyridine (4-AP; a voltage-activated K+ channel blocker), 10-5 M indomethacin (a prostaglandin synthesis inhibitor), 10-5 M clotrimazole (a cytochrome P450 inhibitor) or 10-5 M cycloheximide (a general protein synthesis inhibitor). Contrarily, the clobenzorex-induced vasorelaxation was significantly attenuated (P<0.05) by 10-5 M L-NAME (a direct inhibitor of nitric oxide synthase), 10-7 M ODQ (an inhibitor of nitric oxide-sensitive guanylyl cyclase), 10-6 M KT 5823 (an inhibitor of protein kinase G), 10-2 M TEA (a Ca2+-activated K+ channel blocker and non-specific voltage-activated K+ channel blocker) and 10-7 M apamin plus 10-7 M charybdotoxin (blockers of small- and large-conductance Ca2+-activated K+ channels, respectively), and was blocked by 8×10-2 M potassium (a high concentration) and removal of the vascular endothelium. These results suggest that the direct vasorelaxant effect by clobenzorex on phenylephrine-precontracted rat aortic rings involved stimulation of the NO/cGMP/PKG/Ca2+-activated K+ channel pathway.


Subject(s)
Animals , Male , Rats , Amphetamines/pharmacology , Aorta, Thoracic/drug effects , Endothelium, Vascular/drug effects , Vasodilation , Vasodilator Agents/pharmacology , Calcium Channels/drug effects , Calcium Channels/metabolism , Nitric Oxide Synthase Type III/drug effects , Nitric Oxide Synthase Type III/metabolism , Potassium Channels, Voltage-Gated/drug effects , Potassium Channels, Voltage-Gated/metabolism , Potassium Channels/drug effects , Potassium Channels/metabolism , Rats, Wistar
8.
Article in Chinese | WPRIM | ID: wpr-344183

ABSTRACT

<p><b>OBJECTIVE</b>To assess the association of KCNE1 (rs1805127) and KCNE4 (rs12621643) polymorphisms with atrial fibrillation (AF) among ethnic Uygur and Han Chinese in Xinjiang.</p><p><b>METHODS</b>A case-control study was carried out. The patients and controls were selected based on ethnicity, gender and age with an 1:1 ratio. DNA was extracted from peripheral blood samples. Genotypes of KCNE1 (rs1805127) and KCNE4 (rs12621643) were determined with a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay.</p><p><b>RESULTS</b>Multivariate Logistic regression analysis showed KCNE1 (rs1805127) to be an independent risk factor for AF among Uygurs, while KCNE4 (rs12621643) was a risk factor for both Uygur and Han patients with AF (P < 0.05). The population attributable risk percentage (PARc%) of obstructive sleep apnea hpoventilation syndrome, obesity, hypertension, cholesterol, Hcy, hs-CRP, IL-6, KCNE1 (rs1805127) and KCNE4 (rs12621643) were 9.68%, 12.06%, 15.76%, 6.91%, 11.37%, 17.78%, 9.31%, 11.27% and 6.46% among the Uygurs, respectively. The PARc% of drinking, hypertension, cholesterol, Hcy, hs-CRP, IL-6, and KCNE4 (rs12621643) were 12.94%, 14.48%, 7.24%, 8.49%, 17.29%, 9.49% and 7.41% among Hans.</p><p><b>CONCLUSION</b>The KCNE1 (rs1805127) appears to an independent risk factor for AF in the Uygur population. And the KCNE4 (rs12621643) was an independent risk factor for AF among both Uygurs and Hans. Management of the risk factors of AF based on testing of "risk genes" may have an impact on the prevention and treatment of AF.</p>


Subject(s)
Atrial Fibrillation , Genetics , Case-Control Studies , China , Ethnology , Humans , Polymorphism, Genetic , Potassium Channels, Voltage-Gated , Genetics , Risk Factors
9.
Article in English | WPRIM | ID: wpr-33726

ABSTRACT

Autoimmune limbic encephalitis is a rare cause of encephalitic disease. It is associated with various target antigens and is difficult to diagnose, and experience with its treatment is limited. This case report describes a 69-year-old man, who presented with life-threatening hyponatremia and confusion, following several months of gradually worsening faciobrachial dystonic seizures. Faciobrachial dystonic seizures are a well-described feature classically observed in voltage-gated potassium channel autoimmune encephalitis. The presence of chronic hyponatremia without cognitive dysfunction, eventually culminating in an acute episode of encephalopathy and severe hyponatremia, is a pattern of natural history not previously documented in this condition.


Subject(s)
Aged , Brain Diseases , Dystonia , Encephalitis , Humans , Hyponatremia , Limbic Encephalitis , Natural History , Potassium Channels, Voltage-Gated , Seizures
10.
Chinese Medical Journal ; (24): 200-205, 2016.
Article in English | WPRIM | ID: wpr-310683

ABSTRACT

<p><b>BACKGROUND</b>Adenomyosis (AM) has impaired contraction. This study aimed to explore the expression of potassium channels related to contraction in myometrial smooth muscle cells (MSMCs) of AM.</p><p><b>METHODS</b>Uterine tissue samples from 22 patients (cases) with histologically confirmed AM and 12 (controls) with cervical intraepithelial neoplasia were collected for both immunohistochemistry and real-time polymerase chain reaction to detect the expression of large conductance calcium- and voltage-sensitive K + channel (BKCa)-α/β subunits, voltage-gated potassium channel (Kv) 4.2, and Kv4.3. Student's t-test was used to compare the expression.</p><p><b>RESULTS</b>The BKCa-α/β subunits, Kv4.2, and Kv4.3 were located in smooth muscle cells, glandular epithelium, and stromal cells. However, BKCa-β subunit expression in endometrial glands of the controls was weak, and Kv4.3 was almost undetectable in the controls. The expression of BKCa-α messenger RNA (mRNA) (0.62 ± 0.19-fold decrease, P < 0.05) and Kv4.3 mRNA (0.67 ± 0.20-fold decrease, P < 0.05) decreased significantly in the MSMCs of the control group compared with the AM group. However, there were no significant differences in BKCa-β subunit mRNA or Kv4.2 mRNA.</p><p><b>CONCLUSIONS</b>The BKCa-α mRNA and the Kv4.3 mRNA are expressed significantly higher in AM than those in the control group, that might cause the abnormal uterus smooth muscle contractility, change the microcirculation of uterus to accumulate the inflammatory factors, impair the endometrium further, and aggravate the pain.</p>


Subject(s)
Adenomyosis , Metabolism , Adult , Female , Humans , Immunohistochemistry , Large-Conductance Calcium-Activated Potassium Channels , Metabolism , Male , Myocytes, Smooth Muscle , Metabolism , Potassium Channels, Voltage-Gated , Metabolism , Real-Time Polymerase Chain Reaction , Shal Potassium Channels , Metabolism , Uterine Contraction , Physiology , Uterine Neoplasms , Metabolism , Uterus , Metabolism
11.
Chinese Journal of Stomatology ; (12): 137-142, 2016.
Article in Chinese | WPRIM | ID: wpr-259428

ABSTRACT

<p><b>OBJECTIVE</b>To evaluate the expression of voltage-gated potassium channel Kv3.4 and to determine its significance in oral squamous cell carcinoma (OSCC) and precancerous lesions.</p><p><b>METHODS</b>Immunohistochemical SP methods were performed to detect the expression of Kv3.4 at tissue level on 57 paraffin-embedded samples collected from Pathology Department of Anhui Province Stomatological Hospital during January 2013 to June 2014. The relationships between the expression of Kv3.4 and precancerous lesion and clinical pathologic factors of oral squamous cell carcinoma, such as pathologic classification, clinical stage and lymph node metastasis, were also analyzed. Totally 6 samples of normal oral mucosa tissue, 23 samples of OSCC and 13 samples of precancerous lesions were collected from the Department of Oral and Maxillofacial Surgery of The First Affiliated Hospital of Anhui Medical University during May 2014 to March 2015. Real-time quantitative PCR and Western blotting were used to detect the expression of Kv3.4 in these 42 samples at molecular and protein levels.</p><p><b>RESULTS</b>Real-time quantitative PCR showed the relative expression quantity of Kv3.4 in normal oral mucosa, precancerous lesions, and OSCC tissues were 0.85±0.48, 3.50±2.51 and 18.48±7.70, respectively. The relative expression quantity of Kv3.4 in OSCC and precancerous lesions were higher than that in normal group, the differences were both statistically significant (P=0.002, P=0.029). The relative expression quantities of Kv3.4 protein in precancerous and OSCC tissues were 0.87±0.14 and 0.35±0.03 respectively by Western blotting, and both were higher than that in normal tissues (0.18±0.10). The differences were statistically significant (P=0.002). In 57 paraffin-embedded samples, the positive expression rates of Kv3.4 in normal, precancerous and OSCC tissues were 2/6, 13/18 and 95% (37/39), respectively. The differences were statistically significant(P<0.05). However, the expression of Kv3.4 did not show obvious correlation with patients' genders, presence of lymph node metastasis and clinical stages (P>0.05).</p><p><b>CONCLUSIONS</b>The expression of Kv3.4 is positively correlated to OSCC's occurrence and development. Detection of the expression of Kv3.4 may be used for early diagnosis and prognostic judgment of oral squamous cell carcinoma and precancerous lesions.</p>


Subject(s)
Carcinoma, Squamous Cell , Metabolism , Pathology , Female , Humans , Lymphatic Metastasis , Male , Mouth Mucosa , Metabolism , Mouth Neoplasms , Metabolism , Pathology , Potassium Channels, Voltage-Gated , Metabolism , Precancerous Conditions , Metabolism , Pathology , Prognosis , Sex Factors
12.
Acta Physiologica Sinica ; (6): 401-408, 2015.
Article in Chinese | WPRIM | ID: wpr-255933

ABSTRACT

The aim of the present study was to investigate the role of calcineurin in the down-regulation of left ventricular transmural voltage-dependent K(+) currents in heart failure. Transverse aorta was banded by using microsurgical techniques to create mouse heart failure model. Sham-operated (Sham) or aorta banded (Band) mice were randomized to receive calcineurin inhibitor cyclosporine A (CsA) or vehicle. The densities and kinetic properties of voltage-dependent K(+) currents, as well as action potential (AP), of left ventricular subendocardial (Endo) and subepicardial (Epi) myocytes were determined by using whole-cell patch-clamp technique. The results showed that calcineurin activity was significant higher in Endo myocytes than that in Epi ones in all the groups. Compared with Sham group, Band mice showed significantly increased calcineurin activity both in Endo and Epi myocytes. CsA significantly reduced calcineurin activity in Band mice. CsA treatment in Band mice partially reversed the down-regulation of Ito density, completely reversed the down-regulation of IK,slow density both in Endo and Epi myocytes, and Iss density in Endo myocytes. In addition, CsA treatment in Band mice partially antagonized the prolongation of action potential duration (APD), and APD at 50% (APD50) and 90% repolarization (APD90) were significantly reduced. Because of non-parallel shortening of APD in Endo and Epi myocytes, the ratio of Endo/Epi APD90 was reduced from 4.8:1 in Band mice to 2.6:1 in CsA-treated mice, which was close to that in Sham mice. The results suggest that non-parallel activation of calcineurin in Endo and Epi myocytes contributes to the down-regulation of transmural voltage-dependent K(+) currents and the amplification of transmural dispersion of repolarization (TDR) in left ventricular failure hearts. Inhibition of calcineurin may be a potential new therapeutic strategy to prevent and cure arrhythmias and sudden death in heart failure.


Subject(s)
Action Potentials , Animals , Calcineurin , Physiology , Calcineurin Inhibitors , Pharmacology , Cyclosporine , Pharmacology , Disease Models, Animal , Down-Regulation , Heart , Heart Failure , Mice , Patch-Clamp Techniques , Potassium Channels, Voltage-Gated , Physiology , Ventricular Function, Left
13.
Braz. j. med. biol. res ; 47(10): 876-885, 10/2014. tab, graf
Article in English | LILACS | ID: lil-722165

ABSTRACT

The aim of the present study was to determine the mechanisms underlying the relaxant effect of adrenomedullin (AM) in rat cavernosal smooth muscle (CSM) and the expression of AM system components in this tissue. Functional assays using standard muscle bath procedures were performed in CSM isolated from male Wistar rats. Protein and mRNA levels of pre-pro-AM, calcitonin receptor-like receptor (CRLR), and Subtypes 1, 2 and 3 of the receptor activity-modifying protein (RAMP) family were assessed by Western immunoblotting and quantitative real-time polymerase chain reaction, respectively. Nitrate and 6-keto-prostaglandin F1α (6-keto-PGF1α; a stable product of prostacyclin) levels were determined using commercially available kits. Protein and mRNA of AM, CRLR, and RAMP 1, -2, and -3 were detected in rat CSM. Immunohistochemical assays demonstrated that AM and CRLR were expressed in rat CSM. AM relaxed CSM strips in a concentration-dependent manner. AM22-52, a selective antagonist for AM receptors, reduced the relaxation induced by AM. Conversely, CGRP8-37, a selective antagonist for calcitonin gene-related peptide receptors, did not affect AM-induced relaxation. Preincubation of CSM strips with NG-nitro-L-arginine-methyl-ester (L-NAME, nitric oxide synthase inhibitor), 1H-(1,2,4)oxadiazolo[4,3-a]quinoxalin-1-one (ODQ, quanylyl cyclase inhibitor), Rp-8-Br-PET-cGMPS (cGMP-dependent protein kinase inhibitor), SC560 [5-(4-chlorophenyl)-1-(4-methoxyphenyl)-3-trifluoromethyl pyrazole, selective cyclooxygenase-1 inhibitor], and 4-aminopyridine (voltage-dependent K+ channel blocker) reduced AM-induced relaxation. On the other hand, 7-nitroindazole (selective neuronal nitric oxide synthase inhibitor), wortmannin (phosphatidylinositol 3-kinase inhibitor), H89 (protein kinase A inhibitor), SQ22536 [9-(tetrahydro-2-furanyl)-9H-purin-6-amine, adenylate cyclase inhibitor], glibenclamide (selective blocker of ATP-sensitive K+ channels), and apamin (Ca2+-activated channel blocker) did not affect AM-induced relaxation. AM increased nitrate levels and 6-keto-PGF1α in rat CSM. The major new contribution of this research is that it demonstrated expression of AM and its receptor in rat CSM. Moreover, we provided evidence that AM-induced relaxation in this tissue is mediated by AM receptors by a mechanism that involves the nitric oxide-cGMP pathway, a vasodilator prostanoid, and the opening of voltage-dependent K+ channels.


Subject(s)
Animals , Male , Adrenomedullin/pharmacology , Calcitonin Receptor-Like Protein/analysis , Muscle, Smooth/drug effects , Parasympatholytics/pharmacology , Penis/drug effects , Vasodilator Agents/pharmacology , /pharmacology , /analysis , Adrenomedullin/genetics , Adrenomedullin/metabolism , Blotting, Western , Calcitonin Receptor-Like Protein/antagonists & inhibitors , Cyclic GMP-Dependent Protein Kinases/antagonists & inhibitors , Cyclooxygenase Inhibitors/pharmacology , Dose-Response Relationship, Drug , Enzyme Inhibitors/pharmacology , Immunohistochemistry , Indazoles/pharmacology , Muscle Relaxation , Muscle, Smooth/metabolism , Nitric Oxide Synthase/antagonists & inhibitors , Nitric Oxide/analysis , Nitric Oxide/analogs & derivatives , Penis/metabolism , Potassium Channels, Voltage-Gated/metabolism , Rats, Wistar , Real-Time Polymerase Chain Reaction , RNA, Messenger/metabolism , Receptor Activity-Modifying Protein 1/genetics , Receptor Activity-Modifying Protein 1/metabolism , /metabolism , /genetics , /metabolism , Receptors, Calcitonin Gene-Related Peptide/metabolism
14.
Biol. Res ; 47: 1-11, 2014. ilus, graf, tab
Article in English | LILACS | ID: biblio-950713

ABSTRACT

BACKGROUND: Black widow spider (L. tredecimguttatus) has toxic components not only in the venomous glands, but also in other parts of the body and its eggs. It is biologically important to investigate the molecular basis of the egg toxicity. RESULTS: In the present work, an aqueous extract was prepared from the eggs of the spider and characterized using multiple physiological and biochemical strategies. Gel electrophoresis and mass spectrometry demonstrated that the eggs are rich in high-molecular-mass proteins and the peptides below 5 kDa. The lyophilized extract of the eggs had a protein content of 34.22% and was shown to have a strong toxicity towards mammals and insects. When applied at a concentration of 0.25 mg/mL, the extract could completely block the neuromuscular transmission in mouse isolated phrenic nerve-hemidiaphragm preparations within 12.0 ± 1.5 min. Using whole-cell patch-clamp technique, the egg extract was demonstrated to be able to inhibit the voltage-activated Na+, K+and Ca2+ currents in rat DRG neurons. In addition, the extract displayed activities of multiple hydrolases. Finally, the molecular basis of the egg toxicity was discussed. CONCLUSIONS: The eggs of black widow spiders are rich in proteinous compounds particularly the high-molecular-mass proteins with different types of biological activity The neurotoxic and other active compounds in the eggs are believed to play important roles in the eggs' toxic actions.


Subject(s)
Animals , Mice , Rats , Ovum/chemistry , Tissue Extracts/chemistry , Black Widow Spider/chemistry , Arthropod Proteins/toxicity , Ovum/physiology , Phrenic Nerve/drug effects , Tissue Extracts/toxicity , Calcium Channels/drug effects , Cockroaches/drug effects , Potassium Channels, Voltage-Gated/drug effects , Animal Shells/physiology , Animal Shells/chemistry , Arthropod Proteins/isolation & purification , Voltage-Gated Sodium Channels/drug effects , Ganglia, Spinal/drug effects
15.
Chinese Medical Journal ; (24): 1482-1486, 2014.
Article in English | WPRIM | ID: wpr-322243

ABSTRACT

<p><b>BACKGROUND</b>Congenital long QT syndrome (LQTS) is an ion channelopathy associated with genetic mutations. It is well known that most LQTS patients (91%) have a single mutation. The purpose of this study was to investigate the clinical characteristics of congenital LQTS patients with bigenic mutations in Taiwan, China.</p><p><b>METHODS</b>Congenital LQTS patients were recruited consecutively at Taiwan University Hospital in Taiwan from 2003 to 2009. The diagnosis of LQTS was defined by an LQTS Schwartz score greater than 4. Mutation screening in KCNQ1, KCNH2, KCNE1, and SCN5A was performed using direct sequencing.</p><p><b>RESULTS</b>Three of 16 LQTS patients (18.7%) were identified with bigenic mutations. One patient had missense mutations in KCNQ1 and KCNH2, the second in KCNQ1 and KCNE1, and the third in KCNH2 and SCN5A. The mean age at onset of LQTS for patients with bigenic mutations was (17 ± 3) years, and all of these patients were female. Two of them experienced seizure and one presented with syncope, although one of them had a family history of syncope. The mean QTc interval was (515 ± 17) ms, similar to those with single mutation or SNPs ((536 ± 74) ms, P = 0.63). Compared to those LQTS patients with single mutation or SNPs, a significantly higher percentage of LQTS patients with bigenic mutations presented with seizure and were younger at onset of the first index event (P = 0.03 and 0.001, respectively), but lower percentage of them presented with sudden cardiac death (P = 0.03).</p><p><b>CONCLUSIONS</b>Although the percentage of bigenic mutations in LQTS is less than 10% in Caucasian populations, we identified 3 of 16 LQTS patients (18.7%, 95% confidence interval: 0.04-0.46) with bigenic mutations in Taiwan. However, the severity of their clinical presentations was not higher than those patients with single mutation or SNPs.</p>


Subject(s)
Adolescent , Adult , Aged , ERG1 Potassium Channel , Ether-A-Go-Go Potassium Channels , Genetics , Female , Genotype , Humans , KCNQ1 Potassium Channel , Genetics , Long QT Syndrome , Genetics , Pathology , Male , Middle Aged , Mutation , Genetics , Polymorphism, Single Nucleotide , Genetics , Potassium Channels, Voltage-Gated , Genetics , Young Adult
16.
Article in English | WPRIM | ID: wpr-113288

ABSTRACT

BACKGROUND: Acquired neuromyotonia (NMT) forms part of the spectrum of acquired peripheral nerve hyperexcitability syndrome, and is thought to be caused by antibodies to voltage-gated potassium channels (VGKC). Exertional weakness is unusual unless autoimmune myasthenia gravis (MG) is superimposed. CASE REPORT: A case of acquired NMT accompanied by exertional weakness without coexistence of seropositive MG is reported herein. CONCLUSIONS: Clinical and electrophysiological observations suggest that the cholinergic overactivity in NMT can compromise the safety factor sufficiently to cause a defect in neuromuscular junction transmission.


Subject(s)
Antibodies , Isaacs Syndrome , Myasthenia Gravis , Neuromuscular Junction , Peripheral Nerves , Potassium Channels, Voltage-Gated
17.
Article in Korean | WPRIM | ID: wpr-91988

ABSTRACT

Limbic encephalitis (LE) is characterized by short-term memory loss, disorientation, agitation, seizures, and histological evidence of mesial temporal lobe inflammation. Leucine-rich, glioma inactivated 1 (LGI1) is the autoantigen associated with limbic encephalitis that was previously attributed to voltage-gated potassium channels. We report herein a 54-year-old female with LGI1-related limbic encephalitis who presented with recurrent episodes of episodic memory impairment, depressive mood, and phantosmia. Her symptoms dramatically improved with steroid therapy.


Subject(s)
Antibodies , Dihydroergotamine , Female , Glioma , Humans , Inflammation , Limbic Encephalitis , Memory, Episodic , Memory, Short-Term , Middle Aged , Potassium Channels, Voltage-Gated , Seizures , Temporal Lobe
18.
Article in Korean | WPRIM | ID: wpr-189695

ABSTRACT

Anti-LGI1 (leucine-rich glioma inactivated-1) antibody encephalitis is one of autoimmune encephalitis. We report a 66-year-old man who presented with frequent, brief dystonic seizures which involve predominantly ipsilateral face and arm without cognitive impairment. Brain MRI showed normal finding. Serum and CSF tests revealed anti-LGI1 antibody. His symptom was not relieved by antiepileptic drugs, but completely controlled after immunotherapy. This case indicates that recognition of the brief, dystonic seizures should do tests for anti-LGI1 antibodies.


Subject(s)
Aged , Antibodies , Anticonvulsants , Arm , Brain , Encephalitis , Glioma , Humans , Immunotherapy , Magnetic Resonance Imaging , Potassium Channels, Voltage-Gated , Seizures
19.
Article in English | WPRIM | ID: wpr-290172

ABSTRACT

Chlorogenic acid (5-caffeoylquinic acid, CGA) is a phenolic compound that is found ubiquitously in plants, fruits and vegetables and is formed via the esterification of caffeic acid and quinic acid. In addition to its notable biological functions against cardiovascular diseases, type-2 diabetes and inflammatory conditions, CGA was recently hypothesized to be an alternative for the treatment of neurological diseases such as Alzheimer's disease and neuropathic pain disorders. However, its mechanism of action is unclear. Voltage-gated potassium channel (Kv) is a crucial factor in the electro-physiological processes of sensory neurons. Kv has also been identified as a potential therapeutic target for inflammation and neuropathic pain disorders. In this study, we analysed the effects of CGA on the two main subtypes of Kv in trigeminal ganglion neurons, namely, the IK,A and IK,V channels. Trigeminal ganglion (TRG) neurons were acutely disassociated from the rat TRG, and two different doses of CGA (0.2 and 1 mmol⋅L(-1)) were applied to the cells. Whole-cell patch-clamp recordings were performed to observe alterations in the activation and inactivation properties of the IK,A and IK,V channels. The results demonstrated that 0.2 mmol⋅L(-1) CGA decreased the peak current density of IK,A. Both 0.2 mmol⋅L(-1) and 1 mmol⋅L(-1) CGA also caused a significant reduction in the activation and inactivation thresholds of IK,A and IK,V. CGA exhibited a strong effect on the activation and inactivation velocities of IK,A and IK,V. These findings provide novel evidence explaining the biological effects of CGA, especially regarding its neurological effects.


Subject(s)
Analgesics , Pharmacology , Animals , Animals, Newborn , Cell Culture Techniques , Chlorogenic Acid , Pharmacology , Ion Channel Gating , Membrane Potentials , Neurons , Neurotransmitter Agents , Pharmacology , Patch-Clamp Techniques , Potassium Channels, Voltage-Gated , Rats , Rats, Sprague-Dawley , Trigeminal Ganglion
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