1
|
Aboregela AM. Approaches based on natural products and miRNAs in pituitary adenomas: unveiling therapeutic intervention. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2024:10.1007/s00210-024-03347-6. [PMID: 39102032 DOI: 10.1007/s00210-024-03347-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2024] [Accepted: 07/30/2024] [Indexed: 08/06/2024]
Abstract
Pituitary adenomas (PAs) are tumors originating in the pituitary gland, a small gland located at the base of the brain. They are the most common type of pituitary tumor, affecting approximately 1 in 10 people over their lifetime. Common symptoms include headaches, vision problems, hormonal imbalances, and weight changes. Treatment options depend on the type and size of the adenoma and may consist of medication, surgery, radiation therapy, or a combination. PAs are typically benign and slow-growing, but they can cause significant health issues if left untreated. Proper diagnosis and management by an experienced multidisciplinary team is important for achieving the best outcomes. Natural compounds like celastrol, curcumin, quercetin, apigenin, resveratrol, epigallocatechin gallate (EGCG), and genistein have shown the ability to inhibit cell growth, promote cell death, and suppress hormone activity in pituitary tumor cells, suggesting their potential as alternative or complementary treatments for PAs. MicroRNAs (miRNAs) are a kind of tiny RNA molecules that do not code for proteins and have a vital function in controlling gene expression. These 21-23 nucleotide-long molecules regulate gene expression by binding to complementary sequences in mRNA molecules, leading to mRNA degradation. miRNAs participate in a wide range of biological activities, including apoptosis, metastasis, differentiation, and proliferation. The research indicates that miRNAs play a crucial role in the pathogenesis, therapeutic approaches, diagnosis, and prognosis of PAs. This review article will provide a comprehensive analysis of the current understanding of the efficacy of naturally derived anti-cancer agents in the treatment of PAs. Furthermore, the study provides a comprehensive assessment of the miRNAs in PAs, their role in the development of PAs, and their potential application in the treatment of the condition.
Collapse
Affiliation(s)
- Adel Mohamed Aboregela
- Anatomy Department, College of Medicine, University of Bisha, P.O Box 551, Bisha, 61922, Saudi Arabia.
| |
Collapse
|
2
|
Bo X, Chen J, Mu J, Dong X, Ren Z, Liu J, Wang S. Quercetin promotes the secretion of musk by regulating the hormone level and microbial structure of forest musk deer. Integr Zool 2024; 19:596-611. [PMID: 37789560 DOI: 10.1111/1749-4877.12763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
Musk is a scarce and precious medical resource secreted by male forest musk deer (FMD). Current research to promote musk secretion in FMD has used almost exclusively hormone injections, but this approach can be detrimental to the health of FMD. In order to conserve this endangered species as much as possible while increasing the production of musk, this study first used bioinformatics methods to predict the function of quercetin, a flavonoid that promotes testosterone (T) production and prevents late-onset male hypogonadism. On the basis of good prediction effect, different concentrations of quercetin were added to the diet of FMD. The results showed that quercetin could change the levels of T, luteinizing hormone releasing hormone, luteinizing hormone, and estradiol, and regulate the structure of intestinal microorganisms and musk microorganisms of FMD. Moreover, there is a correlation among musk components, hormones, intestinal microorganisms, and musk microorganisms, which indicates that the production of musk may be regulated by these three at the same time, and the addition of quercetin with 800 mg per kg diet could significantly increase the yield of muscone (P < 0.05), the most effective ingredient in musk. In addition, quercetin decreased the high level of cortisol during musk secretion, which may relieve the stress on FMD in this process. This may help to protect the health of FMD. Combined with the results of software prediction, we finally proposed a possible mechanism for the complex process of musk secretion in FMD with a view to providing ideas for further studies.
Collapse
Affiliation(s)
- Xinyu Bo
- College of Animal Science and Technology, Northwest A & F University, Shaanxi, China
| | - Jialing Chen
- College of Animal Science and Technology, Northwest A & F University, Shaanxi, China
| | - Jinzhan Mu
- College of Animal Science and Technology, Northwest A & F University, Shaanxi, China
| | - Xianggui Dong
- College of Animal Science and Technology, Northwest A & F University, Shaanxi, China
| | - Zhanjun Ren
- College of Animal Science and Technology, Northwest A & F University, Shaanxi, China
| | - Jinyao Liu
- College of Animal Science and Technology, Northwest A & F University, Shaanxi, China
| | - Shuhui Wang
- College of Animal Science and Technology, Northwest A & F University, Shaanxi, China
| |
Collapse
|
3
|
Hung TY, Wu SN, Huang CW. Concerted suppressive effects of carisbamate, an anti-epileptic alkyl-carbamate drug, on voltage-gated Na + and hyperpolarization-activated cation currents. Front Cell Neurosci 2023; 17:1159067. [PMID: 37293624 PMCID: PMC10244622 DOI: 10.3389/fncel.2023.1159067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 05/02/2023] [Indexed: 06/10/2023] Open
Abstract
Carisbamate (CRS, RWJ-333369) is a new anti-seizure medication. It remains unclear whether and how CRS can perturb the magnitude and/or gating kinetics of membrane ionic currents, despite a few reports demonstrating its ability to suppress voltage-gated Na+ currents. In this study, we observed a set of whole-cell current recordings and found that CRS effectively suppressed the voltage-gated Na+ (INa) and hyperpolarization-activated cation currents (Ih) intrinsically in electrically excitable cells (GH3 cells). The effective IC50 values of CRS for the differential suppression of transient (INa(T)) and late INa (INa(L)) were 56.4 and 11.4 μM, respectively. However, CRS strongly decreased the strength (i.e., Δarea) of the nonlinear window component of INa (INa(W)), which was activated by a short ascending ramp voltage (Vramp); the subsequent addition of deltamethrin (DLT, 10 μM) counteracted the ability of CRS (100 μM, continuous exposure) to suppress INa(W). CRS strikingly decreased the decay time constant of INa(T) evoked during pulse train stimulation; however, the addition of telmisartan (10 μM) effectively attenuated the CRS (30 μM, continuous exposure)-mediated decrease in the decay time constant of the current. During continued exposure to deltamethrin (10 μM), known to be a pyrethroid insecticide, the addition of CRS resulted in differential suppression of the amplitudes of INa(T) and INa(L). The amplitude of Ih activated by a 2-s membrane hyperpolarization was diminished by CRS in a concentration-dependent manner, with an IC50 value of 38 μM. For Ih, CRS altered the steady-state I-V relationship and attenuated the strength of voltage-dependent hysteresis (Hys(V)) activated by an inverted isosceles-triangular Vramp. Moreover, the addition of oxaliplatin effectively reversed the CRS-mediated suppression of Hys(V). The predicted docking interaction between CRS and with a model of the hyperpolarization-activated cyclic nucleotide-gated (HCN) channel or between CRS and the hNaV1.7 channel reflects the ability of CRS to bind to amino acid residues in HCN or hNaV1.7 channel via hydrogen bonds and hydrophobic interactions. These findings reveal the propensity of CRS to modify INa(T) and INa(L) differentially and to effectively suppress the magnitude of Ih. INa and Ih are thus potential targets of the actions of CRS in terms of modulating cellular excitability.
Collapse
Affiliation(s)
- Te-Yu Hung
- Department of Pediatrics, Chi Mei Medical Center, Tainan, Taiwan
| | - Sheng-Nan Wu
- Department of Physiology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- College of Medicine, Institute of Basic Medical Sciences, National Cheng Kung University, Tainan, Taiwan
- School of Medicine, College of Medicine, National Sun Yat-sen University, Kaohsiung City, Taiwan
| | - Chin-Wei Huang
- Department of Neurology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| |
Collapse
|
4
|
Chen M, Wu Q. Roles and mechanisms of natural drugs on sinus node dysfunction. Biomed Pharmacother 2023; 164:114777. [PMID: 37229801 DOI: 10.1016/j.biopha.2023.114777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 04/18/2023] [Accepted: 04/23/2023] [Indexed: 05/27/2023] Open
Abstract
Sinus node dysfunction is a common arrhythmia disorder with a high incidence and significant social and economic burden. Currently, there are no effective drugs for treating chronic sinus node dysfunction. The disease is associated with ion channel disturbances caused by aging, fibrosis, inflammation, oxidative stress, and autonomic dysfunction. Natural active substances and Chinese herbal medicines have been widely used and extensively studied in the medical community for the treatment of arrhythmias. Multiple studies have demonstrated that various active ingredients and Chinese herbal medicines, such as astragaloside IV, quercetin, and ginsenosides, exhibit antioxidant effects, reduce fibrosis, and maintain ion channel stability, providing promising drugs for treating sinus node dysfunction. This article summarizes the research progress on natural active ingredients and Chinese herbal formulas that regulate sick sinoatrial node function, providing valuable references for the treatment of sinus node dysfunction.
Collapse
Affiliation(s)
- Meilian Chen
- Quanzhou Hospital of Traditional Chinese Medicine, Fujian 362000, China
| | - Qiaomin Wu
- Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing 100053, China.
| |
Collapse
|
5
|
Wang L, Wang Z, Yang Z, Wang X, Yan L, Wu J, Liu Y, Fu B, Yang H. Potential common mechanism of four Chinese patent medicines recommended by diagnosis and treatment protocol for COVID-19 in medical observation period. Front Med (Lausanne) 2022; 9:874611. [PMID: 36388945 PMCID: PMC9643314 DOI: 10.3389/fmed.2022.874611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Accepted: 10/10/2022] [Indexed: 11/13/2022] Open
Abstract
The global epidemic has been controlled to some extent, while sporadic outbreaks still occur in some places. It is essential to summarize the successful experience and promote the development of new drugs. This study aimed to explore the common mechanism of action of the four Chinese patent medicine (CPMs) recommended in the Medical Observation Period COVID-19 Diagnostic and Treatment Protocol and to accelerate the new drug development process. Firstly, the active ingredients and targets of the four CPMs were obtained by the Chinese medicine composition database (TCMSP, TCMID) and related literature, and the common action targets of the four TCMs were sorted out. Secondly, the targets of COVID-19 were obtained through the gene-disease database (GeneCards, NCBI). Then the Venn diagram was used to intersect the common drug targets with the disease targets. And GO and KEGG pathway functional enrichment analysis was performed on the intersected targets with the help of the R package. Finally, the results were further validated by molecular docking and molecular dynamics analysis. As a result, a total of 101 common active ingredients and 21 key active ingredients of four CPMs were obtained, including quercetin, luteolin, acacetin, kaempferol, baicalein, naringenin, artemisinin, aloe-emodin, which might be medicinal substances for the treatment of COVID-19. TNF, IL6, IL1B, CXCL8, CCL2, IL2, IL4, ICAM1, IFNG, and IL10 has been predicted as key targets. 397 GO biological functions and 166 KEGG signaling pathways were obtained. The former was mainly enriched in regulating apoptosis, inflammatory response, and T cell activation. The latter, with 92 entries related to COVID-19, was mainly enriched to signaling pathways such as Coronavirus disease-COVID-19, Cytokine-cytokine receptor interaction, IL-17 signaling pathway, and Toll-like receptor signaling pathway. Molecular docking results showed that 19/21 of key active ingredients exhibited strong binding activity to recognized COVID-19-related targets (3CL of SARS-CoV-2, ACE2, and S protein), even better than one of these four antiviral drugs. Among them, shinflavanone had better affinity to 3CL, ACE2, and S protein of SARS-CoV-2 than these four antiviral drugs. In summary, the four CPMs may play a role in the treatment of COVID-19 by binding flavonoids such as quercetin, luteolin, and acacetin to target proteins such as ACE2, 3CLpro, and S protein and acting on TNF, IL6, IL1B, CXCL8, and other targets to participate in broad-spectrum antiviral, immunomodulatory and inflammatory responses.
Collapse
Affiliation(s)
- Lin Wang
- Department of Nephrology, First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion, Tianjin, China
| | - Zheyi Wang
- Qilu Hospital, Shandong University, Shandong, China
| | - Zhihua Yang
- Institute of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Xingwang Wang
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou, Guangdong, China
| | - Liping Yan
- School of Pharmacy, Jiangxi University of Traditional Chinese Medicine, Nanchang, China
| | - Jianxiong Wu
- School of Pharmacy, Jiangxi University of Traditional Chinese Medicine, Nanchang, China
| | - Yue Liu
- Department of Nephrology, First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion, Tianjin, China
| | - Baohui Fu
- Department of Nephrology, First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion, Tianjin, China
| | - Hongtao Yang
- Department of Nephrology, First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion, Tianjin, China
| |
Collapse
|
6
|
Functional, electrophysiology, and molecular dynamics analysis of quercetin-induced contraction of rat vascular musculature. Eur J Pharmacol 2022; 918:174778. [DOI: 10.1016/j.ejphar.2022.174778] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 01/14/2022] [Accepted: 01/24/2022] [Indexed: 12/21/2022]
|
7
|
Chang WT, Ragazzi E, Liu PY, Wu SN. Effective block by pirfenidone, an antifibrotic pyridone compound (5-methyl-1-phenylpyridin-2[H-1]-one), on hyperpolarization-activated cation current: An additional but distinctive target. Eur J Pharmacol 2020; 882:173237. [PMID: 32525005 PMCID: PMC7276140 DOI: 10.1016/j.ejphar.2020.173237] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 05/26/2020] [Accepted: 05/29/2020] [Indexed: 12/26/2022]
Abstract
Pirfenidone (PFD), a pyridone compound, is well recognized as an antifibrotic agent tailored for the treatment of idiopathic pulmonary fibrosis. Recently, through its anti-inflammatory and anti-oxidant effects, PFD based clinical trial has also been launched for the treatment of coronavirus disease (COVID-19). To what extent this drug can perturb membrane ion currents remains largely unknown. Herein, the exposure to PFD was observed to depress the amplitude of hyperpolarization-activated cation current (Ih) in combination with a considerable slowing in the activation time of the current in pituitary GH3 cells. In the continued presence of ivabradine or zatebradine, subsequent application of PFD decreased Ih amplitude further. The presence of PFD resulted in a leftward shift in Ih activation curve without changes in the gating charge. The addition of this compound also led to a reduction in area of voltage-dependent hysteresis evoked by long-lasting inverted triangular (downsloping and upsloping) ramp pulse. Neither the amplitude of M-type nor erg-mediated K+ current was altered by its presence. In whole-cell potential recordings, addition of PFD reduced the firing frequency, and this effect was accompanied by the depression in the amplitude of sag voltage elicited by hyperpolarizing current stimulus. Overall, this study highlights evidence that PFD is capable of perturbing specific ionic currents, revealing a potential additional impact on functional activities of different excitable cells.
Collapse
Affiliation(s)
- Wei-Ting Chang
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan, 70101, Taiwan; Division of Cardiology, Internal Medicine, Chi-Mei Medical Center, Tainan, 71004, Taiwan; Department of Biotechnology, Southern Taiwan University of Science and Technology, Tainan, 71004, Taiwan.
| | - Eugenio Ragazzi
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, 35131, Padova, Italy
| | - Ping-Yen Liu
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan, 70101, Taiwan; Division of Cardiology, Internal Medicine, College of Medicine, National Cheng Kung University Hospital, Tainan, 70401, Taiwan.
| | - Sheng-Nan Wu
- Institute of Basic Medical Sciences, National Cheng Kung University Medical College, Tainan, Taiwan; Department of Physiology, National Cheng Kung University Medical College, Tainan, Taiwan; Department of Medical Research, China Medical University Hospital, China Medical University, Taichung, Taiwan.
| |
Collapse
|
8
|
Protective effect of quercetin against myocardial ischemia as a Ca 2+ channel inhibitor: involvement of inhibiting contractility and Ca 2+ influx via L-type Ca 2+ channels. Arch Pharm Res 2020; 43:808-820. [PMID: 32761308 DOI: 10.1007/s12272-020-01261-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Accepted: 08/01/2020] [Indexed: 02/07/2023]
Abstract
Many studies describe the stimulating effect of quercetin on Ca2+ channels and the treatment of cardiovascular diseases such as myocardial ischemia and hypertension. However, these studies are scattered and contradictory. The aim of this study is to elucidate the protective effects of quercetin against isoproterenol (ISO)-induced myocardial ischemia and verify the cellular mechanisms based on the L-type Ca2+ channel (LTCC), Ca2+ transients, and myocardial contractility. An animal model of myocardial ischemia was established by subcutaneous injection of ISO for 2 days. Quercetin significantly reduced J-point elevation, heart rate, reactive oxygen species, serum levels of myocardial enzymes, superoxide dismutase, catalase, glutathione, glutathione peroxidase, glutathione S-transferase and improved heart pathologic morphology. L-type Ca2+ current (ICa-L) was tested in an experiment with isolated rat myocardial cells by using the whole-cell patch-clamp recording technique and IonOptix Myocam detection system. Quercetin reduced ICa-L in a concentration-dependent fashion with a half-maximal inhibitory concentration of 4.67 × 10-4 M. Quercetin also shifted the current-voltage curve upwards, moved the activation and inactivation curves to the left and inhibited the amplitude of the cell shortening and Ca2+ transients. The results showed that quercetin acts as a LTCC inhibitor and exerts a cardioprotective effect by inhibiting Ca2+ influx and contractility in rats.
Collapse
|
9
|
Characterization of Effectiveness in Concerted Ih Inhibition and IK(Ca) Stimulation by Pterostilbene (Trans-3,5-dimethoxy-4'-hydroxystilbene), a Stilbenoid. Int J Mol Sci 2020; 21:ijms21010357. [PMID: 31948124 PMCID: PMC6981816 DOI: 10.3390/ijms21010357] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 12/31/2019] [Accepted: 01/02/2020] [Indexed: 12/13/2022] Open
Abstract
Pterostilbene (PTER), a natural dimethylated analog of resveratrol, has been demonstrated to produce anti-neoplastic or neuroprotective actions. However, how and whether this compound can entail any perturbations on ionic currents in electrically excitable cells remains unknown. In whole-cell current recordings, addition of PTER decreased the amplitude of macroscopic Ih during long-lasting hyperpolarization in GH3 cells in a concentration-dependent manner, with an effective IC50 value of 0.84 μM. Its presence also shifted the activation curve of Ih along the voltage axis to a more hyperpolarized potential, by 11 mV. PTER at a concentration greater than 10 μM could also suppress l-type Ca2+ and transient outward K+ currents in GH3 cells. With the addition of PTER, IK(Ca) amplitude was increased, with an EC50 value of 2.23 μM. This increase in IK(Ca) amplitude was attenuated by further addition of verruculogen, but not by tolbutamide or TRAM-39. Neither atropine nor nicotine, in the continued presence of PTER, modified the PTER-stimulated IK(Ca). PTER (10 μM) slightly suppressed the amplitude of l-type Ca2+ current and transient outward K+ current. The presence of PTER (3 μM) was also effective at increasing the open-state probability of large-conductance Ca2+-activated K+ (BKCa) channels identified in hippocampal mHippoE-14 neurons; however, its inability to alter single-channel conductance was detected. Our study highlights evidence to show that PTER has the propensity to perturb ionic currents (e.g., Ih and IK(Ca)), thereby influencing the functional activities of neurons, and neuroendocrine or endocrine cells.
Collapse
|
10
|
Huang MH, Liu PY, Wu SN. Characterization of Perturbing Actions by Verteporfin, a Benzoporphyrin Photosensitizer, on Membrane Ionic Currents. Front Chem 2019; 7:566. [PMID: 31508407 PMCID: PMC6714490 DOI: 10.3389/fchem.2019.00566] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 07/25/2019] [Indexed: 01/13/2023] Open
Abstract
Verteporfin (VP), a benzoporphyrin derivative, has been clinically tailored as a photosensitizer and recently known to suppress YAP-TEAD complex accompanied by suppression of the growth in an array of neoplastic cells. However, the detailed information is little available regarding possible modifications of it and its related compounds on transmembrane ionic currents, despite its growing use in clinical settings. In this study, from whole cell recordings, VP (0.3-100 μM) increased the amplitude of Ca2+-activated K+ currents (I K(Ca)) in pituitary tumor (GH3) cells in a concentration-dependent manner with an EC50 value of 2.4 μM. VP-stimulated I K(Ca) in these cells was suppressed by further addition of either paxilline, iberiotoxin, or dithiothreitol, but not by that of tobultamide or TRAM-39. VP at a concentration of 10 μM mildly suppressed the amplitude of delayed-rectifier K+ current; however, it had minimal effects on M-type K+ current. In cell-attached current recordings, addition of VP to the recording medium enhanced the activity of large-conductance Ca2+-activated K+ (BKCa) channels. In the presence of VP, additional illumination with light intensity of 5.5 mW/cm2 raised the probability of BKCa-channel openings further. Addition of VP decreased the peak amplitude of L-type Ca2+ current together with slowed inactivation time course of the current; however, it failed to modify voltage-gated Na+ current. Illumination of GH3 cells in continued presence of VP also induced a non-selective cation current. Additionally, VP increased the activity of BKCa channels in human 13-06-MG glioma cells with an EC50 value of 1.9 μM. Therefore, the effects of VP on ionic currents described herein tend to be upstream of its inhibition of YAP-TEAD complex and they are conceivably likely to contribute to the underlying mechanisms through which it and its structurally similar compounds effect the modifications in functional activities of pituitary or glial neoplastic cells, if the in vivo findings occur.
Collapse
Affiliation(s)
- Mei-Han Huang
- College of Medical and Health Sciences, Fooyin University, Kaohsiung City, Taiwan
| | - Ping-Yen Liu
- Division of Cardiovascular Medicine, National Cheng Kung University Medical College, Tainan City, Taiwan
| | - Sheng-Nan Wu
- Institute of Basic Medical Sciences, National Cheng Kung University Medical College, Tainan City, Taiwan.,Department of Physiology, National Cheng Kung University Medical College, Tainan City, Taiwan
| |
Collapse
|
11
|
Mitochondrial Electron Transport Chain Complex Dysfunction in MeCP2 Knock-Down Astrocytes: Protective Effects of Quercetin Hydrate. J Mol Neurosci 2018; 67:16-27. [PMID: 30519865 DOI: 10.1007/s12031-018-1197-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 10/15/2018] [Indexed: 12/30/2022]
Abstract
Astrocytes play the central role in CNS metabolism to support neuronal functions. Mehyl-CpG-binding protein 2 (MeCP2) is the global transcription factor with differential expression in neuronal and non-neuronal cells. MeCP2 mutation and downstream detrimental effects have been reported in astrocytes also in MeCP2-associated neurodevelopmental disorder-Rett syndrome. Several studies have shown mitochondrial impairment linked to ROS production and reduced ATP synthesis in Rett patients and models, but consequences of MeCP2 deficiency on mitochondrial electron transport chain complexes in astrocytes and effect of known antioxidant quercetin aglycone has not yet been reported. The present study aimed to investigate effect of quercetin on mitochondrial functioning in MeCP2-deficient astrocytes. Our data show onefold upregulated Uqcrc1 and Ndufv2 gene expression, subtle change in protein expression, and significantly reduced mitochondrial respiratory chain complex-II and complex-III enzyme activities in MeCP2 knock-down astrocytes. Intracellular calcium robustly increased and mitochondrial membrane potential decreased, while no change in ROS was observed in MeCP2 knock-down astrocytes. Quercetin increased MeCP2 and normalized Uqcrc1 and Ndufv2 gene expression but did not modulate MeCP2 and Ndufv2 proteins expression. Interestingly, quercetin upregulated significantly the mitochondrial respiratory complex-II, complex-III, and complex-IV activities in dose-dependent manner. It also restored intracellular calcium level and mitochondrial membrane potential. In vitro observations suggest the beneficial effect of quercetin in mitochondrial functioning in MeCP2-deficient condition. There are no reports focusing on role of quercetin in mitochondrial function in MeCP2-deficient astrocytes, and these observations serve as preliminary data to evaluate quercetin's effects in vivo.
Collapse
|
12
|
Wang XF, Song SD, Li YJ, Hu ZQ, Zhang ZW, Yan CG, Li ZG, Tang HF. Protective Effect of Quercetin in LPS-Induced Murine Acute Lung Injury Mediated by cAMP-Epac Pathway. Inflammation 2018; 41:1093-1103. [PMID: 29569077 DOI: 10.1007/s10753-018-0761-3] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Quercetin (Que) as an abundant flavonol element possesses potent antioxidative properties and has protective effect in lipopolysaccharide (LPS)-induced acute lung injury (ALI), but the specific mechanism is still unclear, so we investigated the effect of Que from in vivo and in vitro studies and the related mechanism of cAMP-PKA/Epac pathway. The results in mice suggested that Que can inhibit the release of inflammatory cytokine, block neutrophil recruitment, and decrease the albumin leakage in dose-dependent manners. At the same time, Que can increase the cAMP content of lung tissue, and Epac content, except PKA. The results in epithelial cell (MLE-12) suggested that Que also can inhibit the inflammatory mediators keratinocyte-derived chemokines release after LPS stimulation; Epac inhibitor ESI-09 functionally antagonizes the inhibitory effect of Que; meanwhile, PKA inhibitor H89 functionally enhances the inhibitory effect of Que. Overexpression of Epac1 in MLE-12 suggested that Epac1 enhance the effect of Que. All those results suggested that the protective effect of quercetin in ALI is involved in cAMP-Epac pathway.
Collapse
Affiliation(s)
- Xue-Feng Wang
- Second Affiliated Hospital, Zhejiang Chinese Medical University, Hangzhou, 310005, China
| | - Shun-de Song
- Zhejiang Respiratory Drugs Research Laboratory, School of Basic Medical Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Ya-Jun Li
- Zhejiang Respiratory Drugs Research Laboratory, School of Basic Medical Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Zheng Qiang Hu
- Zhejiang Respiratory Drugs Research Laboratory, School of Basic Medical Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Zhe-Wen Zhang
- Zhejiang Respiratory Drugs Research Laboratory, School of Basic Medical Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Chun-Guang Yan
- Department of Pathogenic Biology and Immunology, Southeast University School of Medicine, Nanjing, 210009, China
| | - Zi-Gang Li
- Department of Anesthesiology, Women's Hospital,School of Medicine, Zhejiang University , Hangzhou, 310006, China
| | - Hui-Fang Tang
- Zhejiang Respiratory Drugs Research Laboratory, School of Basic Medical Sciences, Zhejiang University, Hangzhou, 310058, China.
| |
Collapse
|
13
|
Zatkova M, Bacova Z, Puerta F, Lestanova Z, Alanazi M, Kiss A, Reichova A, Castejon AM, Ostatnikova D, Bakos J. Projection length stimulated by oxytocin is modulated by the inhibition of calcium signaling in U-87MG cells. J Neural Transm (Vienna) 2018; 125:1847-1856. [DOI: 10.1007/s00702-018-1933-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Accepted: 09/21/2018] [Indexed: 12/12/2022]
|
14
|
Fusi F, Spiga O, Trezza A, Sgaragli G, Saponara S. The surge of flavonoids as novel, fine regulators of cardiovascular Ca v channels. Eur J Pharmacol 2016; 796:158-174. [PMID: 28012974 DOI: 10.1016/j.ejphar.2016.12.033] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 12/15/2016] [Accepted: 12/20/2016] [Indexed: 01/28/2023]
Abstract
Ion channels underlie a wide variety of physiological processes that involve rapid changes in cell dynamics, such as cardiac and vascular smooth muscle contraction. Overexpression or dysfunction of these membrane proteins are the basis of many cardiovascular diseases that represent the leading cause of morbidity and mortality for human beings. In the last few years, flavonoids, widely distributed in the plant kingdom, have attracted the interest of many laboratories as an emerging class of fine ion, in particular Cav, channels modulators. Pieces of in vitro evidence for direct as well as indirect effects exerted by various flavonoids on ion channel currents are now accumulating in the scientific literature. This activity may be responsible, at least in part, for the beneficial and protective effects of dietary flavonoids toward cardiovascular diseases highlighted in several epidemiological studies. Here we examine numerous studies aimed at analysing this feature of flavonoids, focusing on the mechanisms that promote their sometimes controversial activities at cardiovascular Cav channels. New methodological approaches, such as molecular modelling and docking to Cav1.2 channel α1c subunit, used to elucidate flavonoids intrinsic mechanism of action, are introduced. Moreover, flavonoid-membrane interaction, bioavailability, and antioxidant activity are taken into account and discussed.
Collapse
Affiliation(s)
- Fabio Fusi
- Dipartimento di Scienze della Vita, Università degli Studi di Siena, via A. Moro 2, 53100 Siena, Italy.
| | - Ottavia Spiga
- Dipartimento di Biotecnologie, Chimica e Farmacia, Università degli Studi di Siena, via A. Moro 2, 53100 Siena, Italy
| | - Alfonso Trezza
- Dipartimento di Biotecnologie, Chimica e Farmacia, Università degli Studi di Siena, via A. Moro 2, 53100 Siena, Italy
| | - Giampietro Sgaragli
- Dipartimento di Scienze della Vita, Università degli Studi di Siena, via A. Moro 2, 53100 Siena, Italy
| | - Simona Saponara
- Dipartimento di Scienze della Vita, Università degli Studi di Siena, via A. Moro 2, 53100 Siena, Italy
| |
Collapse
|
15
|
Hanski L, Vuorela P. Lead Discovery Strategies for Identification of Chlamydia pneumoniae Inhibitors. Microorganisms 2016; 4:E43. [PMID: 27916800 PMCID: PMC5192526 DOI: 10.3390/microorganisms4040043] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 10/28/2016] [Accepted: 11/04/2016] [Indexed: 12/18/2022] Open
Abstract
Throughout its known history, the gram-negative bacterium Chlamydia pneumoniae has remained a challenging target for antibacterial chemotherapy and drug discovery. Owing to its well-known propensity for persistence and recent reports on antimicrobial resistence within closely related species, new approaches for targeting this ubiquitous human pathogen are urgently needed. In this review, we describe the strategies that have been successfully applied for the identification of nonconventional antichlamydial agents, including target-based and ligand-based virtual screening, ethnopharmacological approach and pharmacophore-based design of antimicrobial peptide-mimicking compounds. Among the antichlamydial agents identified via these strategies, most translational work has been carried out with plant phenolics. Thus, currently available data on their properties as antichlamydial agents are described, highlighting their potential mechanisms of action. In this context, the role of mitogen-activated protein kinase activation in the intracellular growth and survival of C. pneumoniae is discussed. Owing to the complex and often complementary pathways applied by C. pneumoniae in the different stages of its life cycle, multitargeted therapy approaches are expected to provide better tools for antichlamydial therapy than agents with a single molecular target.
Collapse
Affiliation(s)
- Leena Hanski
- Pharmaceutical Biology, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, Helsinki FI-00014, Finland.
| | - Pia Vuorela
- Pharmaceutical Biology, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, Helsinki FI-00014, Finland.
| |
Collapse
|
16
|
Sandireddy R, Yerra VG, Komirishetti P, Areti A, Kumar A. Fisetin Imparts Neuroprotection in Experimental Diabetic Neuropathy by Modulating Nrf2 and NF-κB Pathways. Cell Mol Neurobiol 2016; 36:883-892. [PMID: 26399251 DOI: 10.1007/s10571-015-0272-9] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Accepted: 09/15/2015] [Indexed: 01/02/2023]
Abstract
The current study is aimed to assess the therapeutic potential of fisetin, a phytoflavonoid in streptozotocin (STZ)-induced experimental diabetic neuropathy (DN) in rats. Fisetin was administered (5 and 10 mg/kg) for 2 weeks (7th and 8th week) post STZ administration. Thermal and mechanical hyperalgesia were assessed by measuring tactile sensitivity to thermal and mechanical stimuli, respectively. Motor nerve conduction velocity (MNCV) was determined using power lab system and sciatic nerve blood flow (NBF) was determined using laser Doppler system. Nerve sections were processed for TUNEL assay and NF-κB, COX-2 immunohistochemical staining. Sciatic nerve homogenate was used for biochemical and Western blotting analysis. MNCV and sciatic NBF deficits associated with DN were ameliorated in fisetin administered rats. Fisetin treatment reduced the interleukin-6 and tumour necrosis factor-alpha in sciatic nerves of diabetic rats (p < 0.001). Protein expression studies have identified that the therapeutic benefit of fisetin might be through regulation of redox sensitive transcription factors such as nuclear erythroid 2-related factor 2 (Nrf2) and nuclear factor kappa B (NF-κB). Our study provides an evidence for the therapeutic potential of fisetin in DN through simultaneous targeting of NF-κB and Nrf2.
Collapse
Affiliation(s)
- Reddemma Sandireddy
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER)-Hyderabad, Bala Nagar, Hyderabad, TG, 500037, India
| | - Veera Ganesh Yerra
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER)-Hyderabad, Bala Nagar, Hyderabad, TG, 500037, India
| | - Prashanth Komirishetti
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER)-Hyderabad, Bala Nagar, Hyderabad, TG, 500037, India
| | - Aparna Areti
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER)-Hyderabad, Bala Nagar, Hyderabad, TG, 500037, India
| | - Ashutosh Kumar
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER)-Hyderabad, Bala Nagar, Hyderabad, TG, 500037, India.
| |
Collapse
|
17
|
Hsu HT, Tseng YT, Lo YC, Wu SN. Ability of naringenin, a bioflavonoid, to activate M-type potassium current in motor neuron-like cells and to increase BKCa-channel activity in HEK293T cells transfected with α-hSlo subunit. BMC Neurosci 2014; 15:135. [PMID: 25539574 PMCID: PMC4288500 DOI: 10.1186/s12868-014-0135-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 12/11/2014] [Indexed: 12/17/2022] Open
Abstract
Background Naringenin (NGEN) is a citrus bioflavonoid known to have beneficial health properties; however, the ionic mechanism of its actions remains largely unclear. In this study, we attempted to evaluate the possible effects of NGEN on K+ currents in NSC-34 neuronal cells and in HEK293T cells expressing α-hSlo. Results NGEN increased M-type K+ current (IK(M)) in a concentration-dependent manner with an EC50 value of 9.8 μM in NSC-34 cells. NGEN shifted the activation curve of IK(M) conductance to the more negative potentials. In cell-attached recordings, NGEN or flupirtine enhanced the activity of M-type K+ (KM) channels with no changes in single-channel amplitude. NGEN (10 μM) had minimal effect on erg-mediated K+ currents. Under cell-attached voltage-clamp recordings, NGEN decreased the frequency of spontaneous action currents and further application of linopirdine can reverse NGEN-induced inhibition of firing. In HEK293T cells expressing α-hSlo, this compound increased the amplitude of Ca2+-activated K+ current (IK(Ca)). Under inside-out recordings, NGEN applied to the intracellular side of the detached patch enhanced the activity of large-conductance Ca2+-activated K+ (BKCa) channels. Moreover, from the study of a modeled neuron, burst firing of simulated action potentials (APs) was reduced in the presence of the increased conductances of both KM and KCa channels. Fast-slow analysis of AP bursting from this model also revealed that as the conductances of both KM and BKCa channels were increased by two-fold, the voltage nullcline was shifted in an upward direction accompanied by the compression of burst trajectory. Conclusions The present results demonstrate that activation of both KM and BKCa channels caused by NGEN might combine to influence neuronal activity if similar channels were functionally co-expressed in central neurons in vivo.
Collapse
Affiliation(s)
- Hung-Te Hsu
- Graduate Institute of Medicine, Kaohsiung Medical University, Kaohsiung, 80708, Taiwan. .,Department of Anesthesia, Kaohsiung Medical University Hospital, Kaohsiung City, 80708, Taiwan.
| | - Yu-Ting Tseng
- Department of Pharmacology, School of Medicine, Kaohsiung Medical University, Kaohsiung, 80708, Taiwan. .,Graduate Institute of Natural Products, School of Pharmacy, Kaohsiung Medical University, Kaohsiung, 80708, Taiwan.
| | - Yi-Ching Lo
- Graduate Institute of Medicine, Kaohsiung Medical University, Kaohsiung, 80708, Taiwan. .,Department of Pharmacology, School of Medicine, Kaohsiung Medical University, Kaohsiung, 80708, Taiwan. .,Graduate Institute of Natural Products, School of Pharmacy, Kaohsiung Medical University, Kaohsiung, 80708, Taiwan.
| | - Sheng-Nan Wu
- Department of Physiology, National Cheng Kung University Medical College, Tainan City, 70101, Taiwan. .,Institute of Basic Medical Sciences, National Cheng Kung University Medical College, Tainan City, 70101, Taiwan.
| |
Collapse
|
18
|
Zholobenko A, Modriansky M. Silymarin and its constituents in cardiac preconditioning. Fitoterapia 2014; 97:122-32. [DOI: 10.1016/j.fitote.2014.05.016] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Revised: 05/21/2014] [Accepted: 05/22/2014] [Indexed: 01/28/2023]
|
19
|
Stimulation of cytosolic and mitochondrial calcium mobilization by indomethacin in Caco-2 cells: Modulation by the polyphenols quercetin, resveratrol and rutin. Biochim Biophys Acta Gen Subj 2012; 1820:2052-61. [DOI: 10.1016/j.bbagen.2012.09.015] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Revised: 09/02/2012] [Accepted: 09/19/2012] [Indexed: 12/23/2022]
|
20
|
Ahn SH, Kim HJ, Jeong I, Hong YJ, Kim MJ, Rhie DJ, Jo YH, Hahn SJ, Yoon SH. Grape seed proanthocyanidin extract inhibits glutamate-induced cell death through inhibition of calcium signals and nitric oxide formation in cultured rat hippocampal neurons. BMC Neurosci 2011; 12:78. [PMID: 21810275 PMCID: PMC3160962 DOI: 10.1186/1471-2202-12-78] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2011] [Accepted: 08/03/2011] [Indexed: 11/30/2022] Open
Abstract
Background Proanthocyanidin is a polyphenolic bioflavonoid with known antioxidant activity. Some flavonoids have a modulatory effect on [Ca2+]i. Although proanthocyanidin extract from blueberries reportedly affects Ca2+ buffering capacity, there are no reports on the effects of proanthocyanidin on glutamate-induced [Ca2+]i or cell death. In the present study, the effects of grape seed proanthocyanidin extract (GSPE) on glutamate-induced excitotoxicity was investigated through calcium signals and nitric oxide (NO) in cultured rat hippocampal neurons. Results Pretreatment with GSPE (0.3-10 μg/ml) for 5 min inhibited the [Ca2+]i increase normally induced by treatment with glutamate (100 μM) for 1 min, in a concentration-dependent manner. Pretreatment with GSPE (6 μg/ml) for 5 min significantly decreased the [Ca2+]i increase normally induced by two ionotropic glutamate receptor agonists, N-methyl-D-aspartate and alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA). GSPE further decreased AMPA-induced response in the presence of 1 μM nimodipine. However, GSPE did not affect the 50 mM K+-induced increase in [Ca2+]i. GSPE significantly decreased the metabotropic glutamate receptor agonist (RS)-3,5-Dihydroxyphenylglycine-induced increase in [Ca2+]i, but it did not affect caffeine-induced response. GSPE (0.3-6 μg/ml) significantly inhibited synaptically induced [Ca2+]i spikes by 0.1 mM [Mg2+]o. In addition, pretreatment with GSPE (6 μg/ml) for 5 min inhibited 0.1 mM [Mg2+]o- and glutamate-induced formation of NO. Treatment with GSPE (6 μg/ml) significantly inhibited 0.1 mM [Mg2+]o- and oxygen glucose deprivation-induced neuronal cell death. Conclusions All these data suggest that GSPE inhibits 0.1 mM [Mg2+]o- and oxygen glucose deprivation-induced neurotoxicity through inhibition of calcium signals and NO formation in cultured rat hippocampal neurons.
Collapse
Affiliation(s)
- Seo-Hee Ahn
- Department of Physiology, College of Medicine, The Catholic University of Korea, 505 Banpo-dong, Seocho-gu, Seoul 137-701, Korea
| | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Modification of activation kinetics of delayed rectifier K+ currents and neuronal excitability by methyl-β-cyclodextrin. Neuroscience 2011; 176:431-41. [DOI: 10.1016/j.neuroscience.2010.10.060] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Revised: 10/19/2010] [Accepted: 10/20/2010] [Indexed: 11/23/2022]
|
22
|
Xu F, Proft J, Gibbs S, Winkfein B, Johnson JN, Syed N, Braun JEA. Quercetin targets cysteine string protein (CSPalpha) and impairs synaptic transmission. PLoS One 2010; 5:e11045. [PMID: 20548785 PMCID: PMC2883571 DOI: 10.1371/journal.pone.0011045] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2009] [Accepted: 05/21/2010] [Indexed: 01/25/2023] Open
Abstract
Background Cysteine string protein (CSPα) is a synaptic vesicle protein that displays unique anti-neurodegenerative properties. CSPα is a member of the conserved J protein family, also called the Hsp40 (heat shock protein of 40 kDa) protein family, whose importance in protein folding has been recognized for many years. Deletion of the CSPα in mice results in knockout mice that are normal for the first 2–3 weeks of life followed by an unexplained presynaptic neurodegeneration and premature death. How CSPα prevents neurodegeneration is currently not known. As a neuroprotective synaptic vesicle protein, CSPα represents a promising therapeutic target for the prevention of neurodegenerative disorders. Methodology/Principal Findings Here, we demonstrate that the flavonoid quercetin promotes formation of stable CSPα-CSPα dimers and that quercetin-induced dimerization is dependent on the unique cysteine string region. Furthermore, in primary cultures of Lymnaea neurons, quercetin induction of CSPα dimers correlates with an inhibition of synapse formation and synaptic transmission suggesting that quercetin interfers with CSPα function. Quercetin's action on CSPα is concentration dependent and does not promote dimerization of other synaptic proteins or other J protein family members and reduces the assembly of CSPα:Hsc70 units (70kDa heat shock cognate protein). Conclusions/Significance Quercetin is a plant derived flavonoid and popular nutritional supplement proposed to prevent memory loss and altitude sickness among other ailments, although its precise mechanism(s) of action has been unclear. In view of the therapeutic promise of upregulation of CSPα and the undesired consequences of CSPα dysfunction, our data establish an essential proof of principle that pharmaceutical agents can selectively target the neuroprotective J protein CSPα.
Collapse
Affiliation(s)
- Fenglian Xu
- Department of Anatomy and Cell Biology, University of Calgary, Calgary, Alberta, Canada
| | - Juliane Proft
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Sarah Gibbs
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Bob Winkfein
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Jadah N. Johnson
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Naweed Syed
- Department of Anatomy and Cell Biology, University of Calgary, Calgary, Alberta, Canada
| | - Janice E. A. Braun
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
- * E-mail:
| |
Collapse
|
23
|
Shin TJ, Choi SH, Lee BH, Pyo MK, Hwang SH, Kim BR, Lee SM, Han YS, Lee JH, Park JH, Kim HC, Rhim H, Nah SY. Effects of Quercetin on Human α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid Receptor-Mediated Ion Currents. Biol Pharm Bull 2010; 33:1615-9. [DOI: 10.1248/bpb.33.1615] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Tae-Joon Shin
- Department of Physiology, College of Veterinary Medicine and Bio/Molecular Informatics Center, Konkuk University
| | - Sun-Hye Choi
- Department of Physiology, College of Veterinary Medicine and Bio/Molecular Informatics Center, Konkuk University
| | - Byung-Hwan Lee
- Department of Physiology, College of Veterinary Medicine and Bio/Molecular Informatics Center, Konkuk University
| | - Mi Kyung Pyo
- Department of Physiology, College of Veterinary Medicine and Bio/Molecular Informatics Center, Konkuk University
| | - Sung-Hee Hwang
- Department of Physiology, College of Veterinary Medicine and Bio/Molecular Informatics Center, Konkuk University
| | - Bo-Ra Kim
- Department of Physiology, College of Veterinary Medicine and Bio/Molecular Informatics Center, Konkuk University
| | - Sang-Mok Lee
- Department of Physiology, College of Veterinary Medicine and Bio/Molecular Informatics Center, Konkuk University
| | - Ye Sun Han
- Advanced Technology Fusion, Konkuk University
| | - Jun-Ho Lee
- Department of Physiology, College of Oriental Medicine, Kyung Hee University
| | - Ji-Ho Park
- Graduate School of East-West Medical Science, Kyung Hee University
| | - Hyoung-Chun Kim
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University
| | - Hyewhon Rhim
- Life Science Division, Korea Institute of Science and Technology
| | - Seung-Yeol Nah
- Department of Physiology, College of Veterinary Medicine and Bio/Molecular Informatics Center, Konkuk University
| |
Collapse
|
24
|
Suri S, Liu XH, Rayment S, Hughes DA, Kroon PA, Needs PW, Taylor MA, Tribolo S, Wilson VG. Quercetin and its major metabolites selectively modulate cyclic GMP-dependent relaxations and associated tolerance in pig isolated coronary artery. Br J Pharmacol 2009; 159:566-75. [PMID: 20050852 DOI: 10.1111/j.1476-5381.2009.00556.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND AND PURPOSE Quercetin is a major flavonoid that contributes to the reduced risk of cardiovascular disease associated with dietary ingestion of fruits and vegetables. We have pharmacologically characterized the effect of quercetin, and its sulphate and glucuronide metabolites, on vasoconstrictor and vasodilator responses in the porcine isolated coronary artery. EXPERIMENTAL APPROACH Segments of the porcine coronary artery were prepared for either isometric tension recording or determination of cyclic GMP content. The effect of quercetin and metabolites on submaximal responses to U46619 was examined in the presence and absence of substance P, bradykinin, forskolin, sodium nitroprusside (SNP) and glyceryl trinitrate (GTN). KEY RESULTS Quercetin and quercetin 3'-sulphate inhibited endothelin and U46619-induced contractions with greater potency (three- to fivefold) against the former, while quercetin 3-glucoronide was inactive. Quercetin enhanced both the cyclic GMP content of the artery (threefold) and cyclic GMP-dependent relaxations to GTN and SNP (two to threefold), but forskolin-induced relaxations were unaffected. Although the effect of quercetin was qualitatively similar to that noted for UK-114,542, a selective inhibitor of phosphodiesterase 5, it was still evident against SNP-induced relaxations in the presence of 10 nM UK-114,542. Quercetin and quercetin 3'-sulphate significantly reduced the development of GTN-associated 'tolerance'. CONCLUSIONS AND IMPLICATIONS Quercetin and quercetin 3'-sulphate inhibited receptor-mediated contractions of the porcine isolated coronary artery by an endothelium-independent action. Quercetin selectively enhanced cyclic-GMP-dependent relaxations by a mechanism not involving phosphodiesterase 5 inhibition. In addition, quercetin and quercetin 3'-sulphate opposed GTN-induced tolerance in vitro, which may be beneficial for patients treated for angina pectoris.
Collapse
Affiliation(s)
- S Suri
- School of Biomedical Sciences, Faculty of Medical and Health Sciences, Queens Medical Centre, University of Nottingham, Nottingham, UK
| | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Chen BS, Lo YC, Peng H, Hsu TI, Wu SN. Effects of ranolazine, a novel anti-anginal drug, on ion currents and membrane potential in pituitary tumor GH(3) cells and NG108-15 neuronal cells. J Pharmacol Sci 2009; 110:295-305. [PMID: 19609066 DOI: 10.1254/jphs.09018fp] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Ranolazine, a piperazine derivative, is currently approved for the treatment of chronic angina. However, its ionic mechanisms in other types of cells remain unclear, although it is thought to be a selective blocker of late Na(+) current. This study was conducted to evaluate the possible effects of ranolazine on Na(+) current (I(Na)), L-type Ca(2+) current (I(Ca,L)), inwardly rectifying K(+) current (I(K(IR))), delayed-rectifier K(+) current (I(K(DR))), and Ca(2+)-activated K(+) current (I(K(Ca))) in pituitary tumor (GH(3)) cells. Ranolazine depressed the transient and late components of I(Na) with different potencies. This drug exerted an inhibitory effect on I(K(IR)) with an IC(50) value of 0.92 microM, while it slightly inhibited I(K(DR)) and I(K(Ca)). It shifted the steady-state activation curve of I(K(IR)) to more positive potentials with no change in the gating charge of the channel. Ranolazine (30 microM) also reduced the activity of large-conductance Ca(2+)-activated K(+) channels in HEK293T cells expressing alpha-hSlo. Under current-clamp conditions, low concentrations (e.g., 1 microM) of ranolazine increased the firing of action potentials, while at high concentrations (>or=10 microM), it diminished the firing discharge. The exposure to ranolazine also suppressed I(Na) and I(K(IR)) effectively in NG108-15 neuronal cells. Our study provides evidence that ranolazine could block multiple ion currents such as I(Na) and I(K(IR)) and suggests that these actions may contribute to some of the functional activities of neurons and endocrine or neuroendocrine cells in vivo.
Collapse
Affiliation(s)
- Bing-Shuo Chen
- Institute of Basic Medical Sciences, National Cheng Kung University Medical College, Taiwan
| | | | | | | | | |
Collapse
|
26
|
Shen AY, Huang MH, Wang TS, Wu HM, Kang YF, Chen CL. Thymol-evoked Ca 2+ Mobilization and Ion Currents in Pituitary GH 3 Cells. Nat Prod Commun 2009. [DOI: 10.1177/1934578x0900400601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
In this study, an attempt was made to elucidate the effects of thymol, a monocyclic phenolic compound, on Ca2+ mobilization and ion currents in pituitary GH3 cells with the aid of fura-2 fluorimetry and the whole-cell voltage-clamp technique. Thymol increased intracellular Ca2+ concentrations ([Ca2+]i) in GH3 cells loaded with Ca2+-sensitive dye fura-2. Removing extracellular Ca2+ reduced the thymol-induced [Ca2+]i rise. In Ca2+-free solution, thymol-evoked [Ca2+]i rise was unchanged by depleting the Ca2+ store with thapsigargin (1 μM), while the thapsigargin-induced [Ca2+]i rise was reduced by pretreatment with thymol. These results imply that the Ca2+ stores depleted by thymol comprise thapsigargin-sensitive and thapsigargin-insensitive pools. In addition, after depletion of the internal Ca2+ store with 100 μM thymol in Ca2+-free solution, a subsequent application of Ca2+ greatly induced a [Ca2+]i increase. The results indicate that, similar to thapsigargin, 100 μM thymol may activate the capacitative calcium entry (CCE) channel. However, thymol (100 μM) had a slight depressant action in L-type calcium current ( ICaL). The stimulatory actions of thymol on Ca2+ signaling may partly be responsible for the underlying cellular mechanisms through which it affects neuroendocrine functions.
Collapse
Affiliation(s)
- Ai-Yu Shen
- College of Medical and Health Sciences, Fooyin University, Ta-Liao, Kaohsiung Hsien, Taiwan
| | - Mei-Han Huang
- College of Medical and Health Sciences, Fooyin University, Ta-Liao, Kaohsiung Hsien, Taiwan
| | - Trey-Shy Wang
- College of Environmental and Life Sciences, Fooyin University, Ta-Liao, Kaohsiung Hsien, Taiwan
| | - Hui-Ming Wu
- College of Medical and Health Sciences, Fooyin University, Ta-Liao, Kaohsiung Hsien, Taiwan
| | - Ya-Fei Kang
- College of Medical and Health Sciences, Fooyin University, Ta-Liao, Kaohsiung Hsien, Taiwan
| | - Chi-Lan Chen
- College of Medical and Health Sciences, Fooyin University, Ta-Liao, Kaohsiung Hsien, Taiwan
| |
Collapse
|
27
|
Saponara S, Sgaragli G, Fusi F. Quercetin antagonism of Bay K 8644 effects on rat tail artery L-type Ca2+ channels. Eur J Pharmacol 2008; 598:75-80. [DOI: 10.1016/j.ejphar.2008.08.016] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2008] [Revised: 08/11/2008] [Accepted: 08/22/2008] [Indexed: 01/06/2023]
|
28
|
Wu SN, Peng H, Chen BS, Wang YJ, Wu PY, Lin MW. Potent activation of large-conductance Ca2+-activated K+ channels by the diphenylurea 1,3-bis-[2-hydroxy-5-(trifluoromethyl)phenyl]urea (NS1643) in pituitary tumor (GH3) cells. Mol Pharmacol 2008; 74:1696-704. [PMID: 18809671 DOI: 10.1124/mol.108.049106] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
1,3-Bis-[2-hydroxy-5-(trifluoromethyl)phenyl]urea (NS1643) is reported to be an activator of human ether-à-go-go-related gene current. However, it remains unknown whether it has any effects on other types of ion channels. The effects of NS1643 on ion currents and membrane potential were investigated in this study. NS1643 stimulated Ca(2+)-activated K(+) current [I(K(Ca))] in a concentration-dependent manner with an EC(50) value of 1.8 microM in pituitary tumor (GH(3)) cells. In inside-out recordings, this compound applied to the intracellular side of the detached channels stimulated large-conductance Ca(2+)-activated K(+) (BK(Ca)) channels with no change in single-channel conductance. It shifted the activation curve of BK(Ca) channels to less depolarized voltages without altering the gating charge of the channels. NS1643-stimulated channel activity depended on intracellular Ca(2+), and mean closed time during exposure to NS1643 was reduced. NS1643 (3 microM) had little or no effect on peak amplitude of ether-à-go-go-related gene-mediated K(+) current evoked by membrane hyperpolarization, although it increased the amplitude of late-sustained components of K(+) inward current, which was suppressed by paxilline but not by azimilide. NS1643 (3 microM) had no effect on L-type Ca(2+) current. This compound reduced repetitive firing of action potentials, and further application of paxilline attenuated its decrease in firing rate. In addition, NS1643 enhanced BK(Ca)-channel activity in human embryonic kidney 293T cells expressing alpha-hSlo. In summary, we clearly show that NS1643 interacts directly with the BK(Ca) channel to increase the amplitude of I(K(Ca)) in pituitary tumor (GH(3)) cells. The alpha-subunit of the channel may be a target for the action of this small compound.
Collapse
Affiliation(s)
- Sheng-Nan Wu
- Department of Physiology, National Cheng Kung University Medical College, Tainan, Taiwan.
| | | | | | | | | | | |
Collapse
|
29
|
Wu SN, Wang YJ, Lin MW. Potent stimulation of large-conductance Ca2+-activated K+ channels by rottlerin, an inhibitor of protein kinase C-delta, in pituitary tumor (GH3) cells and in cortical neuronal (HCN-1A) cells. J Cell Physiol 2007; 210:655-66. [PMID: 17133362 DOI: 10.1002/jcp.20866] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The effects of rottlerin, a known inhibitor of protein kinase C-delta activation, on ion currents were investigated in pituitary tumor (GH3) cells. Rottlerin (0.3-100 microM) increased the amplitude of Ca2+-activated K+ current (I K(Ca)) in a concentration-dependent manner with an EC50 value of 1.7 microM. In intracellular perfusion with rottlerin (1 microM) or staurosporine (10 microM), phorbol 12-myristate 13-acetate-induced inhibition of I K(Ca) in these cells was abolished. In cell-attached mode, rottlerin applied on the extracellular side of the membrane caused activation of large-conductance Ca2+-activated K+ (BK(Ca)) channels, and a further application of BAPTA-AM (10 microM) to the bath had no effect on rottlerin-stimulated channel activity. When cells were exposed to rottlerin, the activation curve of these channels was shifted to less positive potential with no change in the slope factor. Rottlerin increased BK(Ca)-channel activity in outside-out patches. Its change in kinetic behavior of BK(Ca) channels is primarily due to an increase in mean open time. With the aid of minimal kinetic scheme, a quantitative description of rottlerin stimulation on BK(Ca) channels in GH3 cells was also provided. Under current-clamp configuration, rottlerin (1 microM) decreased the firing of action potentials. I K(Ca) elicited by simulated action potential waveforms was enhanced by this compound. In human cortical HCN-1A cells, rottlerin (1 microM) could also interact with the BK(Ca) channel to stimulate I K(Ca). Therefore, rottlerin may directly activate BK(Ca) channels in neurons or endocrine cells.
Collapse
Affiliation(s)
- Sheng-Nan Wu
- Department of Physiology, National Cheng Kung University Medical College, Tainan, Taiwan.
| | | | | |
Collapse
|
30
|
Huang MH, So EC, Liu YC, Wu SN. Glucocorticoids stimulate the activity of large-conductance Ca2+ -activated K+ channels in pituitary GH3 and AtT-20 cells via a non-genomic mechanism. Steroids 2006; 71:129-40. [PMID: 16274717 DOI: 10.1016/j.steroids.2005.09.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2004] [Revised: 08/23/2005] [Accepted: 09/07/2005] [Indexed: 12/18/2022]
Abstract
The effects of glucocorticoids on ion currents were investigated in pituitary GH3 and AtT-20 cells. In whole-cell configuration, dexamethasone, a synthetic glucocorticoid, reversibly increased the density of Ca2+ -activated K+ current (IK(Ca)) with an EC50 value of 21 +/- 5 microM. Dexamethasone-induced increase in IK(Ca) density was suppressed by paxilline (1 microM), yet not by glibenclamide (10 microM), pandinotoxin-Kalpha (1 microM) or mifepristone (10 microM). Paxilline is a blocker of large-conductance Ca2+ -activated K+ (BKCa) channels, while glibenclamide and pandinotoxin-Kalpha are blockers of ATP-sensitive and A-type K+ channels, respectively. Mifepristone can block cytosolic glucocorticoid receptors. In inside-out configuration, the application of dexamethasone (30 microM) into the intracellular surface caused no change in single-channel conductance; however, it did increase BKCa -channel activity. Its effect was associated with a negative shift of the activation curve. However, no Ca2+ -sensitiviy of these channels was altered by dexamethasone. Dexamethasone-stimulated channel activity involves an increase in mean open time and a decrease in mean closed time. Under current-clamp configuration, dexamethasone decreased the firing frequency of action potentials. In pituitary AtT-20 cells, dexamethasone (30 microM) also increased BKCa -channel activity. Dexamethasone-mediated stimulation of IK(Ca) presented here that is likely pharmacological, seems to be not linked to a genomic mechanism. The non-genomic, channel-stimulating properties of dexamethasone may partly contribute to the underlying mechanisms by which glucocorticoids affect neuroendocrine function.
Collapse
Affiliation(s)
- Mei-Han Huang
- Institute of Basic Medical Sciences, National Cheng Kung University Medical College, No. 1, University Road, Tainan, Taiwan
| | | | | | | |
Collapse
|
31
|
Liu YC, Wu SN. BAY 41‐2272, a potent activator of soluble guanylyl cyclase, stimulates calcium elevation and calcium‐activated potassium current in pituitary GH3cells. Clin Exp Pharmacol Physiol 2006; 32:1078-87. [PMID: 16445574 DOI: 10.1111/j.1440-1681.2005.04315.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The effects of BAY 41-2272, a nitric oxide-independent activator of soluble guanylyl cyclase, on Ca2+ signalling and ion currents were investigated in pituitary GH3 cells. Intracellular Ca2+ concentrations ([Ca2+]i) in these cells were increased by BAY 41-2272. Removing extracellular Ca2+ abolished the BAY 41-2272-induced increase in [Ca2+]i. After [Ca2+]i was elevated by BAY 41-2272 (300 nmol/L), subsequent application of 1-benzyl-3-(5'-hydroxymethyl-2'-furyl) indazole (YC-1; 1 micromol/L) did not increase [Ca2+]i further. In whole-cell recordings, BAY 41-2272 reversibly stimulated Ca2+-activated K+ current (I(K(Ca))) with an EC50 of 225 +/- 8 nmol/L. At 3 micromol/L, BAY 41-2272 slightly and significantly decreased L-type Ca2+ current. In the cell-attached configuration, BAY 41-2272 (300 nmol/L) enhanced the activity of large-conductance Ca2+-activated K+ (BK(Ca)) channels. After BK(Ca) channel activity was stimulated by spermine NONOate (30 micromol/L) or YC-1 (10 micromol/L) in cell-attached patches, subsequent application of BAY 41-2272 (300 nmol/L) further increased the channel open probability. In the inside-out configuration, BAY 41-2272 applied to the intracellular surface of excised patches enhanced BK(Ca) channel activity. Unlike 1 micromol/L paxilline, 1H-[1,2,4]oxadiazolol-[4,3a] quinoxalin-1-one (ODQ; 10 micromol/L) or heme (10 micromol/L) had no effect on BAY 41-2272-stimulated channel activity. BAY 41-2272 caused no shift in the activation curve of BK(Ca) channels; however, it did increase the Ca2+ sensitivity of these channels. At 300 nmol/L, BAY 41-2272 reduced the firing rate of spontaneous action potentials stimulated by thyrotropin-releasing hormone (10 micromol/L). The BK(Ca) channel activity was also enhanced by 300 nmol/L BAY 41-2272 in neuroblastoma IMR-32 cells. Therefore, the BAY 41-2272-induced increase in [Ca2+]i is primarily explained by an increase in Ca2+ influx. The BAY 41-2272-mediated simulation of IK(Ca) may result from direct activation of BKCa channels and indirectly as a result of elevated [Ca2+]i.
Collapse
Affiliation(s)
- Yen-Chin Liu
- Department of Anaesthesiology, National Cheng-Kung University Medical College, Tainan, Taiwan
| | | |
Collapse
|
32
|
Fusi F, Sgaragli G, Saponara S. Mechanism of myricetin stimulation of vascular L-type Ca2+ current. J Pharmacol Exp Ther 2005; 313:790-7. [PMID: 15665142 DOI: 10.1124/jpet.104.080135] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
An in-depth analysis of the mechanism of the L-type Ca(2+) current [I(Ca(L))] stimulation induced by myricetin was performed in rat tail artery myocytes using the whole-cell patch-clamp method. Myricetin increased I(Ca(L)) in a frequency-, concentration-, and voltage-dependent manner. At holding potentials (V(h)) of -50 and -90 mV, the pEC(50) values were 4.9 +/- 0.1 and 4.2 +/- 0.1, respectively; the latter corresponded to the drug-apparent dissociation constant for resting channels, K(R), of 67.6 microM. Myricetin shifted the maximum of the current-voltage relationship by 10 mV in the hyperpolarizing direction but did not modify the threshold for I(Ca(L)) or the T-type Ca(2+) current. The Ca(2+) channel blockers nifedipine, verapamil, and diltiazem antagonized I(Ca(L)) in the presence of myricetin. Myricetin increased the time to peak of I(Ca(L)) in a voltage- and concentration-dependent manner. Washout reverted myricetin effect on both current kinetics and amplitude at V(h) of -90 mV while reverting only current kinetics at V(h) of -50 mV. At the latter V(h), myricetin shifted the voltage dependence of inactivation and activation curves to more negative potentials by 6.4 and 13.0 mV, respectively, in the mid-potential of the curves. At V(h) of -90 mV, myricetin shifted, in a concentration-dependent manner, the voltage dependence of the inactivation curve to more negative potentials with an apparent dissociation constant for inactivated channels (K(I)) of 13.8 muM. Myricetin induced a frequency- and V(h)-dependent block of I(Ca(L)). In conclusion, myricetin behaves as an L-type Ca(2+) channel agonist that stabilizes the channel in its inactivated state.
Collapse
Affiliation(s)
- Fabio Fusi
- Dipartimento di Scienze Biomediche, Università degli Studi di Siena, Italy.
| | | | | |
Collapse
|