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Ammar OF, Moodley T. Assessment of intracellular calcium and plasmalemmal membrane potential in cryopreserved metaphase II mouse oocytes. In Vitro Cell Dev Biol Anim 2022; 58:441-445. [PMID: 35708817 DOI: 10.1007/s11626-022-00695-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 05/18/2022] [Indexed: 11/05/2022]
Affiliation(s)
- Omar Farhan Ammar
- Nuffield Department of Women's and Reproductive Health, Women's Centre, University of Oxford, John Radcliffe Hospital, Level 3, Oxford, OX3 9DU, UK.
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Darbandi S, Darbandi M, Khorram Khorshid HR, Sengupta P. Electrophysiology of Human Gametes: A Systematic Review. World J Mens Health 2022; 40:442-455. [PMID: 35021309 PMCID: PMC9253800 DOI: 10.5534/wjmh.210107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 09/05/2021] [Accepted: 09/14/2021] [Indexed: 11/15/2022] Open
Abstract
Purpose Oocytes and spermatozoa are electrogenic cells with the ability to respond to electrical stimuli and modulate their electrical properties accordingly. Determination of the ionic events during the gamete maturation helps to design suitable culture media for gametes in assisted reproductive technology (ART). The present systematic review focuses on the electrophysiology of human gametes during different stages of maturation and also during fertilization. Materials and Methods The reports published in the English language between January 2000 and July 2021 were extracted from various electronic scientific databases following the PRISMA checklist using specific MeSH keywords. Results Subsequent to the screening process with defined inclusion and exclusion criteria, 60 articles have been included in this review. Among them, 11 articles were directly related to the electrophysiology of human oocytes and 49 physiology department to the electrophysiology of human spermatozoa. Conclusions Gametes generate electrical currents by ionic exchange, particularly Na+, K+, Cl-, H+, Zn2+, Cu2+, Se2+, Mg2+, HCO3-, and Ca2+ through specific ion channels in different stages of gamete maturation. The ionic concentrations, pH, and other physicochemical variables are modulated during the gametogenesis, maturation, activation, and the fertilization process following gamete function and metabolism. The electrical properties of human gametes change during different stages of maturation. Although it is demonstrated that the electrical properties are significant regulators of cell signaling and are fundamental to gamete maturation and fertilization, their exact roles in these processes are still poorly understood. Further research is required to unveil the intricate electrophysiological processes of human gamete maturation.
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Affiliation(s)
- Sara Darbandi
- Fetal Health Research Center, Hope Generation Foundation, Tehran, Iran
| | - Mahsa Darbandi
- Fetal Health Research Center, Hope Generation Foundation, Tehran, Iran
| | - Hamid Reza Khorram Khorshid
- Gene Therapy and Regenerative Medicine Research Center, Hope Generation Foundation, Tehran, Iran.,Personalized Medicine and Genometabolomics Research Center, Hope Generation Foundation, Tehran, Iran
| | - Pallav Sengupta
- Department of Physiology, Faculty of Medicine, Biosciences and Nursing, MAHSA University, Jenjarom, Selangor, Malaysia.,School of Medical Sciences, Bharath Institute of Higher Education and Research (BIHER), Chennai, India.
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Silvestris E, Cohen M, Cornet D, Jacquesson-Fournols L, Clement P, Chouteau J, Schneider M, Besnard T, Ménézo Y. Supporting the One-Carbon Cycle Restores Ovarian Reserve in Subfertile Women: Absence of Correlation with Urinary Bisphenol A Concentration. Biores Open Access 2017; 6:104-109. [PMID: 29082109 PMCID: PMC5628560 DOI: 10.1089/biores.2017.0016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Environmental endocrine disrupting chemicals (EDCs), including bisphenol A (BPA), induce DNA methylation errors and oxidative stress, and alter fertility. Animal studies have demonstrated that supporting the one-carbon cycle (1-CC) with appropriate dietary supplements can reduce the effects of EDCs. Anti-Mullerian hormone (AMH), a marker of ovarian functionality, has been tested in subfertile female patients, to control this hypothesis in humans. Fifty-five women with a history of 3-7 years of infertility, with at least two assisted reproductive technology (ART) treatment failures, and low serum levels of AMH were enrolled in the study. Before starting any further ART treatment, they were tested for AMH and for follicular count. A urinary control of BPA was proposed. Then a support of the 1-CC, already tested in other clinical studies, was initiated and continued for 4 months. At the end of this period, antral follicle count and serum AMH levels were re-evaluated. The AMH levels before and after treatment were compared using the Wilcoxon test (nonparametric test, non-Gaussian population). Out of the 55 patients, 35 accepted a BPA dosage in the urine. No correlation was found between BPA and serum AMH concentrations. Forty-nine patients followed the full treatment with 1-CC supplements, which resulted in increased AMH levels, independent of initial AMH levels and maternal age (in the range studied), p = 0.0001. Eight patients spontaneously conceived ongoing pregnancies within 3 months, at the end of the protocol. A support of the 1-CC can partly alleviate metabolic derangements induced by environment, as observed in animal models, and improve endocrine background in women.
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Affiliation(s)
- Erica Silvestris
- Division of Gynecology and Obstetrics, University of Bari "Aldo Moro," Bari, Italy.,Clinique Natecia, Lyon, France
| | | | | | | | | | | | | | | | - Yves Ménézo
- Laboratoire Clément, Paris, France.,Laboratoire Oriade, Grenoble, France.,Clinique Belledone, Saint-Martin-d'Hères, France.,Laboratoire LTB, Narbonne, France.,London Fertility Associates, London, England
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Kalehoei E, Azadbakht M. The beneficial effect of repaglinide on in vitro maturation and development ability of immature mouse oocytes. In Vitro Cell Dev Biol Anim 2017; 53:626-31. [PMID: 28432599 DOI: 10.1007/s11626-017-0152-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 04/05/2017] [Indexed: 10/19/2022]
Abstract
Repaglinide is a hypoglycemic drug, causing depolarization of the cell membrane, opening the voltage-gated calcium channels, and then increasing intracellular calcium in the pancreatic B cells by inhibition of the K-ATP-sensitive channels. Oocyte in vitro maturation (IVM) is influenced by different factors such as calcium signaling. In this study, we examined the effects of repaglinide on in vitro maturation and fertilization ability of mouse oocyte. Immature oocytes were isolated from female Naval Medical Research Institute mice which are 6-8 wk old mechanically and then cultured in 30 μl droplets of T6 medium with different concentrations of repaglinide. The control group did not receive repaglinide (R0). Treatment groups received different concentrations (5, 10, and 100 nM and 1 and 10 μM) of repaglinide (R1, R2, R3, R4, and R5, respectively). Oocyte in vitro maturation rate was assessed after 24 h. In vitro fertilization was performed using metaphase II oocytes obtained from R0 and R4 treatments. Embryo cleavage rate was calculated at 48 h post-IVF. Chi-square test was used for evaluating difference between control and treatment groups (p < 0.05). Oocyte maturation rate after 24 h in treatment groups R2, R3, R4, and R5 was significantly higher than that in the control (p < 0.05). Supplementation of medium with 1 μM of repaglinide (R4) during IVM significantly improved outcome of embryo cleavage rate than control at 48 h post-IVF (p < 0.05). In conclusion, repaglinide can be considered as an effective agent for in vitro oocyte maturation and embryo cleavage.
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Xie M, Ye H, Wang H, Charpin-El Hamri G, Lormeau C, Saxena P, Stelling J, Fussenegger M. -cell-mimetic designer cells provide closed-loop glycemic control. Science 2016; 354:1296-1301. [DOI: 10.1126/science.aaf4006] [Citation(s) in RCA: 140] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 11/10/2016] [Indexed: 12/12/2022]
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Telles CJ, Decker SE, Motley WW, Peters AW, Mehr AP, Frizzell RA, Forrest JN. Functional and molecular identification of a TASK-1 potassium channel regulating chloride secretion through CFTR channels in the shark rectal gland: implications for cystic fibrosis. Am J Physiol Cell Physiol 2016; 311:C884-C894. [PMID: 27653983 DOI: 10.1152/ajpcell.00030.2016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 09/18/2016] [Indexed: 11/22/2022]
Abstract
In the shark rectal gland (SRG), apical chloride secretion through CFTR channels is electrically coupled to a basolateral K+ conductance whose type and molecular identity are unknown. We performed studies in the perfused SRG with 17 K+ channel inhibitors to begin this search. Maximal chloride secretion was markedly inhibited by low-perfusate pH, bupivicaine, anandamide, zinc, quinidine, and quinine, consistent with the properties of an acid-sensitive, four-transmembrane, two-pore-domain K+ channel (4TM-K2P). Using PCR with degenerate primers to this family, we identified a TASK-1 fragment in shark rectal gland, brain, gill, and kidney. Using 5' and 3' rapid amplification of cDNA ends PCR and genomic walking, we cloned the full-length shark gene (1,282 bp), whose open reading frame encodes a protein of 375 amino acids that was 80% identical to the human TASK-1 protein. We expressed shark and human TASK-1 cRNA in Xenopus oocytes and characterized these channels using two-electrode voltage clamping. Both channels had identical current-voltage relationships (outward rectifying) and a reversal potential of -90 mV. Both were inhibited by quinine, bupivicaine, and acidic pH. The pKa for current inhibition was 7.75 for shark TASK-1 vs. 7.37 for human TASK-1, values similar to the arterial pH for each species. We identified this protein in SRG by Western blot and confocal immunofluorescent microscopy and detected the protein in SRG and human airway cells. Shark TASK-1 is the major K+ channel coupled to chloride secretion in the SRG, is the oldest 4TM 2P family member identified, and is the first TASK-1 channel identified to play a role in setting the driving force for chloride secretion in epithelia. The detection of this potassium channel in mammalian lung tissue has implications for human biology and disease.
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Affiliation(s)
- Connor J Telles
- Nephrology Division, Department of Medicine, Yale University School of Medicine, New Haven, Connecticut.,Mount Desert Island Biological Laboratory, Salisbury Cove, Maine
| | - Sarah E Decker
- Nephrology Division, Department of Medicine, Yale University School of Medicine, New Haven, Connecticut.,Mount Desert Island Biological Laboratory, Salisbury Cove, Maine
| | - William W Motley
- Nephrology Division, Department of Medicine, Yale University School of Medicine, New Haven, Connecticut.,Mount Desert Island Biological Laboratory, Salisbury Cove, Maine
| | - Alexander W Peters
- Nephrology Division, Department of Medicine, Yale University School of Medicine, New Haven, Connecticut.,Mount Desert Island Biological Laboratory, Salisbury Cove, Maine
| | - Ali Poyan Mehr
- Nephrology Division, Department of Medicine, Yale University School of Medicine, New Haven, Connecticut.,Mount Desert Island Biological Laboratory, Salisbury Cove, Maine
| | - Raymond A Frizzell
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; and.,Mount Desert Island Biological Laboratory, Salisbury Cove, Maine
| | - John N Forrest
- Nephrology Division, Department of Medicine, Yale University School of Medicine, New Haven, Connecticut; .,Mount Desert Island Biological Laboratory, Salisbury Cove, Maine
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Fernandes G, Dasai N, Kozlova N, Mojadadi A, Gall M, Drew E, Barratt E, Madamidola OA, Brown SG, Milne AM, Martins da Silva SJ, Whalley KM, Barratt CLR, Jovanović A. A spontaneous increase in intracellular Ca2+ in metaphase II human oocytes in vitro can be prevented by drugs targeting ATP-sensitive K+ channels. Hum Reprod 2015; 31:287-97. [PMID: 26682579 PMCID: PMC4716808 DOI: 10.1093/humrep/dev300] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Accepted: 10/21/2015] [Indexed: 01/08/2023] Open
Abstract
STUDY QUESTION Could drugs targeting ATP-sensitive K+ (KATP) channels prevent any spontaneous increase in intracellular Ca2+ that may occur in human metaphase II (MII) oocytes under in vitro conditions? SUMMARY ANSWER Pinacidil, a KATP channel opener, and glibenclamide, a KATP channel blocker, prevent a spontaneous increase in intracellular Ca2+ in human MII oocytes. WHAT IS KNOWN ALREADY The quality of the oocyte and maintenance of this quality during in vitro processing in the assisted reproductive technology (ART) laboratory is of critical importance to successful embryo development and a healthy live birth. Maintenance of Ca2+ homeostasis is crucial for cell wellbeing and increased intracellular Ca2+ levels is a well-established indicator of cell stress. STUDY DESIGN, SIZE, DURATION Supernumerary human oocytes (n = 102) collected during IVF/ICSI treatment that failed to fertilize were used from October 2013 to July 2015. All experiments were performed on mature (MII) oocytes. Dynamics of intracellular Ca2+ levels were monitored in oocytes in the following experimental groups: (i) Control, (ii) Dimethyl sulfoxide (DMSO; used to dissolve pinacidil, glibenclamide and 2,4-Dinitrophenol (DNP)), (iii) Pinacidil, (iv) Glibenclamide, (v) DNP: an inhibitor of oxidative phosphorylation, (vi) Pinacidil and DNP and (vii) Glibenclamide and DNP. PARTICIPANTS/MATERIALS/SETTINGS/METHODS Oocytes were collected under sedation as part of routine treatment at an assisted conception unit from healthy women (mean ± SD) age 34.1 ± 0.6 years, n = 41. Those surplus to clinical use were donated for research. Oocytes were loaded with Fluo-3 Ca2+-sensitive dye, and monitored by laser confocal microscopy for 2 h at 10 min intervals. Time between oocyte collection and start of Ca2+ monitoring was 80.4 ± 2.1 h. MAIN RESULTS AND THE ROLE OF CHANCE Intracellular levels of Ca2+ increased under in vitro conditions with no deliberate challenge, as shown by Fluo-3 fluorescence increasing from 61.0 ± 11.8 AU (AU = arbitrary units; n = 23) to 91.8 ± 14.0 AU (n = 19; P < 0.001) after 2 h of monitoring. Pinacidil (100 µM) inhibited this increase in Ca2+ (85.3 ± 12.3 AU at the beginning of the experiment, 81.7 ± 11.0 AU at the end of the experiment; n = 13; P = 0.616). Glibenclamide (100 µM) also inhibited the increase in Ca2+ (74.7 ± 10.6 AU at the beginning and 71.8 ± 10.9 AU at the end of the experiment; n = 13; P = 0.851. DNP (100 mM) induced an increase in intracellular Ca2+ that was inhibited by glibenclamide (100 µM; n = 9) but not by pinacidil (100 µM; n = 5). LIMITATIONS, REASONS FOR CAUTION Owing to clinical and ethical considerations, it was not possible to monitor Ca2+ in MII oocytes immediately after retrieval. MII oocytes were available for our experimentation only after unsuccessful IVF or ICSI, which was, on average, 80.4 ± 2.1 h (n = 102 oocytes) after the moment of retrieval. As the MII oocytes used here were those that were not successfully fertilized, it is possible that they may have been abnormal with impaired Ca2+ homeostasis and, furthermore, the altered Ca2+ homeostasis might have been associated solely with the protracted incubation. WIDER IMPLICATIONS OF THE FINDINGS These results show that maintenance of oocytes under in vitro conditions is associated with intracellular increase in Ca2+, which can be counteracted by drugs targeting KATP channels. As Ca2+ homeostasis is crucial for contributing to a successful outcome of ART, these results suggest that KATP channel openers and blockers should be tested as drugs for improving success rates of ART. STUDY FUNDING/COMPETING INTEREST(S) University of Dundee, MRC (MR/K013343/1, MR/012492/1), NHS Tayside. Funding NHS fellowship (Dr Sarah Martins da Silva), NHS Scotland. The authors declare no conflicts of interest.
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Affiliation(s)
- Gonçalo Fernandes
- Medical Research Institute, Ninewells Hospital and Medical School, University of Dundee, Dundee DD1 9SY, UK
| | - Navin Dasai
- Medical Research Institute, Ninewells Hospital and Medical School, University of Dundee, Dundee DD1 9SY, UK
| | - Natalia Kozlova
- Medical Research Institute, Ninewells Hospital and Medical School, University of Dundee, Dundee DD1 9SY, UK
| | - Albaraa Mojadadi
- Medical Research Institute, Ninewells Hospital and Medical School, University of Dundee, Dundee DD1 9SY, UK Department of Anatomy and Clinical Embryology, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Mandy Gall
- Assisted Conception Unit, NHS Tayside, Ninewells Hospital, Dundee
| | - Ellen Drew
- Assisted Conception Unit, NHS Tayside, Ninewells Hospital, Dundee
| | - Evelyn Barratt
- Assisted Conception Unit, NHS Tayside, Ninewells Hospital, Dundee
| | - Oladipo A Madamidola
- Medical Research Institute, Ninewells Hospital and Medical School, University of Dundee, Dundee DD1 9SY, UK Assisted Conception Unit, NHS Tayside, Ninewells Hospital, Dundee University of Abertay, Dundee, UK
| | | | - Alison M Milne
- Medical Research Institute, Ninewells Hospital and Medical School, University of Dundee, Dundee DD1 9SY, UK
| | - Sarah J Martins da Silva
- Medical Research Institute, Ninewells Hospital and Medical School, University of Dundee, Dundee DD1 9SY, UK Assisted Conception Unit, NHS Tayside, Ninewells Hospital, Dundee
| | | | - Christopher L R Barratt
- Medical Research Institute, Ninewells Hospital and Medical School, University of Dundee, Dundee DD1 9SY, UK Assisted Conception Unit, NHS Tayside, Ninewells Hospital, Dundee
| | - Aleksandar Jovanović
- Medical Research Institute, Ninewells Hospital and Medical School, University of Dundee, Dundee DD1 9SY, UK
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Jovanović S, Ballantyne T, Du Q, Blagojević M, Jovanović A. Phenylephrine preconditioning in embryonic heart H9c2 cells is mediated by up-regulation of SUR2B/Kir6.2: A first evidence for functional role of SUR2B in sarcolemmal KATP channels and cardioprotection. Int J Biochem Cell Biol 2015; 70:23-8. [PMID: 26556311 PMCID: PMC4711337 DOI: 10.1016/j.biocel.2015.10.029] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Revised: 10/22/2015] [Accepted: 10/30/2015] [Indexed: 02/07/2023]
Abstract
ATP-sensitive K+ (KATP) channels were originally described in cardiomyocytes, where physiological levels of intracellular ATP keep them in a closed state. Structurally, these channels are composed of pore-forming inward rectifier, Kir6.1 or Kir6.2, and a regulatory, ATP-binding subunit, SUR1, SUR2A or SUR2B. SUR1 and Kir6.2 form pancreatic type of KATP channels, SUR2A and Kir6.2 form cardiac type of KATP channels, SUR2B and Kir6.1 form vascular smooth muscle type of KATP channels. The presence of SUR2B has been described in cardiomyocytes, but its functional significance and role has remained unknown. Pretreatment with phenylephrine (100 nM) for 24 h increased mRNA levels of SUR2B and Kir6.2, without affecting those levels of SUR1, SUR2A and Kir6.1 in embryonic heart H9c2 cells. Such increase was associated with increased K+ current through KATP channels and Kir6.2/SUR2B protein complexes as revealed by whole cell patch clamp electrophysiology and immunoprecipitation/Western blotting respectively. Pretreatment with phenylephrine (100 nM) generated a cellular phenotype that acquired resistance to chemical hypoxia induced by 2,4-dinitrophenol (DNP; 10 mM), which was accompanied by increased in K+ current in response to DNP (10 mM). Cytoprotection afforded by phenylephrine (100 nM) was abolished by infection of H9c2 cells with adenovirus containing Kir6.2AFA, a mutant form of Kir6.2 with largely reduced K+ conductance. Taking all together, the present findings demonstrate that the activation of α1-adrenoceptors up-regulates SUR2B/Kir6.2 to confer cardioprotection. This is the first account of possible physiological role of SUR2B in cardiomyocytes.
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Affiliation(s)
- Sofija Jovanović
- Medical Research Institute, Division of Cardiovascular & Diabetic Medicine, Ninewells Hospital & Medical School, University of Dundee, UK
| | - Thomas Ballantyne
- Medical Research Institute, Division of Cardiovascular & Diabetic Medicine, Ninewells Hospital & Medical School, University of Dundee, UK
| | - Qingyou Du
- Medical Research Institute, Division of Cardiovascular & Diabetic Medicine, Ninewells Hospital & Medical School, University of Dundee, UK
| | - Miloš Blagojević
- Department of Anatomy, Faculty of Veterinary Medicine, University of Belgrade, Belgrade, Serbia
| | - Aleksandar Jovanović
- Medical Research Institute, Division of Cardiovascular & Diabetic Medicine, Ninewells Hospital & Medical School, University of Dundee, UK.
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RU QIN, TIAN XIANG, WU YUXIANG, WU RIHUI, PI MINGSHAN, LI CHAOYING. Voltage-gated and ATP-sensitive K+ channels are associated with cell proliferation and tumorigenesis of human glioma. Oncol Rep 2013; 31:842-8. [DOI: 10.3892/or.2013.2875] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Accepted: 11/01/2013] [Indexed: 11/05/2022] Open
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Khan F, Choong WL, Du Q, Jovanović A. Real-time RT-PCR threshold cycles value for Kir6.1 from the blood correlates with parameters of vascular function: a potential for the vascular function biomarker? Biomarkers 2013; 18:221-9. [PMID: 23480296 DOI: 10.3109/1354750x.2013.770553] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Abstract We examined the presence of KATP channel subunits, Kir6.1 and SUR2B, mRNAs in the blood and vascular function in healthy volunteers (41 males, 34 females). Real-time reverse transcriptase (RT)-PCR threshold cycles (Ct) was used as an indicator of mRNA levels. Baseline skin perfusion and the post-occlusion reactive hyperemia response exhibited a significant positive correlation with Ct for Kir6.1. There was no correlation between Kir6.1 Ct and brachial artery flow-mediated dilatation. Gender had no influence on relationships between blood Kir6.1 Ct and vascular function. We conclude that blood Kir6.1 mRNA levels could be potentially used as a biomarker of the vascular function.
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Affiliation(s)
- Faisel Khan
- Medical Research Institute, Division of Cardiovascular and Diabetic Medicine, Ninewells Hospital & Medical School, University of Dundee, Dundee DD1 9SY, UK
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Khan F, Choong WL, Du Q, Jovanovi'c A. Real-time RT-PCR Ct values for blood GAPDH correlate with measures of vascular endothelial function in humans. Clin Transl Sci 2013; 6:481-4. [PMID: 24330693 DOI: 10.1111/cts.12053] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
PURPOSE To date, there is a wide range of methods in use to assess endothelial function, each with its own advantages and limitations. Here, we tested hypothesis that real-time RT-PCR threshold value (Ct), which is reflective of mRNA level, for Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) from whole blood is indicative of endothelial function in humans. MATERIALS AND METHODS To assess vascular function, we measured baseline skin perfusion, postocclusion reactive hyperemia (PORH), and brachial artery flow-mediated dilatation (FMD) and tested for a possible correlation between vascular responses and blood GAPDH real-time RT-PCR Ct value in 75 healthy volunteers. RESULTS Tests known to measure, at least in part, endothelial function such as baseline skin perfusion, the 2-minute recovery PORH, and FMD exhibited significant positive correlations with blood GAPDH Ct values. In contrast, there was no significant correlation between Ct values for blood GAPDH and peak PORH, an endothelium-independent parameter. CONCLUSIONS Based on these findings, we report that GAPDH mRNA level in the blood correlates with vascular function in healthy subjects. This suggests that GAPDH mRNA level could be a potential biomarker of vascular endothelial function.
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Affiliation(s)
- Faisel Khan
- Medical Research Institute, Division of Cardiovascular and Diabetic Medicine, Ninewells Hospital & Medical School, University of Dundee, Dundee, United Kingdom
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12
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Du Q, Jovanović S, Tulić L, Sljivančanin D, Jack DW, Zižić V, Abdul KSM, Tulić I, Jovanović A. KATP channels are up-regulated with increasing age in human myometrium. Mech Ageing Dev 2013; 134:98-102. [PMID: 23369859 DOI: 10.1016/j.mad.2013.01.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2012] [Revised: 11/26/2012] [Accepted: 01/12/2013] [Indexed: 11/16/2022]
Abstract
It is well established that ageing is associated with decrease in myometrial efficiency and higher incidence of labour complications. In myometrium, the presence of ATP-sensitive K+ (KATP) channels has been detected and they could be a factor in regulating uterine quiescence in pregnancy and contractions during labour. Here, we have examined a possibility of ageing-mediated regulation of KATP channels in the human myometrium. Myometrial samples were taken from non-pregnant women undergoing hysterectomy (n=34) and from women undergoing caesarean section in late pregnancy (n=36). Real time RT-PCR revealed that mRNAs of all known KATP channel subunits were present in the human myometrium. In non-pregnant myometrium, ageing up-regulated SUR2B/Kir6.1, subunits forming KATP channels in this tissue, without affecting the expression of other channel subunits. In the late pregnant myometrium, the level of subunits that do not form functional KATP channels was not affected by age within 20-41 age range. However, uterine SUR2B and Kir6.1 were up-regulated in parturient over 35 years. An ageing-induced increase in those channel subunits was confirmed by Western blotting. Thus, this study suggests that KATP channels are up-regulated with increasing age in human myometrium. This may help explain, at least partially, increased rate of birth complications in women aged over 35 years.
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Affiliation(s)
- Qingyou Du
- Medical Research Institute, Ninewells Hospital and Medical School, University of Dundee, United Kingdom
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Abstract
Growing oocytes are arrested at the first prophase of meiosis which is morphologically identified by the presence of a large and vesicular nucleus, called the germinal vesicle. The dissolution of the germinal vesicle marks the resumption of meiosis during which the oocyte undergoes massive modifications up to the second meiotic block, which is removed at fertilization. The interval between the first and the second meiotic block is defined as maturation and the events occurring during this period are crucial for ovulation, fertilization, and embryo development. Oocytes are excitable cells that react to stimuli by modifying their electrical properties as a consequence of ion currents flowing through ion channels on the plasma membrane. These electrical changes have been largely described at fertilization whereas little information is available during oocyte maturation. The aim of this review is to give an overview on the involvement of ion channels and ion currents during oocyte maturation in species from invertebrates to mammals. The results summarized here point to the possible functional role of ion channels underlying oocyte growth and maturation.
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Núñez M, Medina V, Cricco G, Croci M, Cocca C, Rivera E, Bergoc R, Martín G. Glibenclamide inhibits cell growth by inducing G0/G1 arrest in the human breast cancer cell line MDA-MB-231. BMC Pharmacol Toxicol 2013; 14:6. [PMID: 23311706 PMCID: PMC3558386 DOI: 10.1186/2050-6511-14-6] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2012] [Accepted: 01/07/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Glibenclamide (Gli) binds to the sulphonylurea receptor (SUR) that is a regulatory subunit of ATP-sensitive potassium channels (KATP channels). Binding of Gli to SUR produces the closure of KATP channels and the inhibition of their activity. This drug is widely used for treatment of type 2-diabetes and it has been signaled as antiproliferative in several tumor cell lines. In previous experiments we demonstrated the antitumoral effect of Gli in mammary tumors induced in rats. The aim of the present work was to investigate the effect of Gli on MDA-MB-231 breast cancer cell proliferation and to examine the possible pathways involved in this action. RESULTS The mRNA expression of the different subunits that compose the KATP channels was evaluated in MDA-MB-231 cells by reverse transcriptase-polymerase chain reaction. Results showed the expression of mRNA for both pore-forming isoforms Kir6.1 and Kir6.2 and for the regulatory isoform SUR2B in this cell line. Gli inhibited cell proliferation assessed by a clonogenic method in a dose dependent manner, with an increment in the population doubling time. The KATP channel opener minoxidil increased clonogenic proliferation, effect that was counteracted by Gli. When cell cycle analysis was performed by flow cytometry, Gli induced a significant cell-cycle arrest in G0/G1 phase, together with an up-regulation of p27 levels and a diminution in cyclin E expression, both evaluated by immunoblot. However, neither differentiation evaluated by neutral lipid accumulation nor apoptosis assessed by different methodologies were detected. The cytostatic, non toxic effect on cell proliferation was confirmed by removal of the drug.Combination treatment of Gli with tamoxifen or doxorubicin showed an increment in the antiproliferative effect only for doxorubicin. CONCLUSIONS Our data clearly demonstrated a cytostatic effect of Gli in MDA-MB-231 cells that may be mediated through KATP channels, associated to the inhibition of the G1-S phase progression. In addition, an interesting observation about the effect of the combination of Gli with doxorubicin leads to future research for a potential novel role for Gli as an adjuvant in breast cancer treatment.
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Affiliation(s)
- Mariel Núñez
- Radioisotopes Laboratory, School of Pharmacy and Biochemistry, University of Buenos Aires, Buenos Aires, Argentina
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