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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] [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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Iguchi K, Saotome M, Yamashita K, Hasan P, Sasaki M, Maekawa Y, Watanabe Y. Pinacidil, a KATP channel opener, stimulates cardiac Na +/Ca 2+ exchanger function through the NO/cGMP/PKG signaling pathway in guinea pig cardiac ventricular myocytes. Naunyn Schmiedebergs Arch Pharmacol 2019; 392:949-959. [PMID: 30919008 DOI: 10.1007/s00210-019-01642-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 03/01/2019] [Indexed: 12/21/2022]
Abstract
Pinacidil, a nonselective ATP-sensitive K+ (KATP) channel opener, has cardioprotective effects for hypertension, ischemia/reperfusion injury, and arrhythmia. This agent abolishes early afterdepolarizations, delayed afterdepolarizations (DADs), and abnormal automaticity in canine cardiac ventricular myocytes. DADs are well known to be caused by the Na+/Ca2+ exchange current (INCX). In this study, we used the whole-cell patch-clamp technique and Fura-2/AM (Ca2+-indicator) method to investigate the effect of pinacidil on INCX in isolated guinea pig cardiac ventricular myocytes. In the patch-clamp study, pinacidil enhanced INCX in a concentration-dependent manner. The half-maximal effective concentration values were 23.5 and 23.0 μM for the Ca2+ entry (outward) and Ca2+ exit (inward) components of INCX, respectively. The pinacidil-induced INCX increase was blocked by L-NAME, a nitric oxide (NO) synthase inhibitor, by ODQ, a soluble guanylate cyclase inhibitor, and by KT5823, a cyclic guanosine monophosphate (cGMP)-dependent protein kinase (PKG) inhibitor, but not by N-2-mercaptopropyonyl glycine (MPG), a reactive oxygen species (ROS) scavenger. Glibenclamide, a nonselective KATP channel inhibitor, blocked the pinacidil-induced INCX increase, while 5-HD, a selective mitochondria KATP channel inhibitor, did not. In the Fura-2/AM study pinacidil also enhanced intracellular Ca2+ concentration, which was inhibited by L-NAME, ODQ, KT5823, and glibenclamide, but not by MPG and 5-HD. Sildenafil, a phosphodiesterase 5 inhibitor, increased further the pinacidil-induced INCX increase. Sodium nitroprusside, a NO donor, also increased INCX. In conclusion, pinacidil may stimulate cardiac Na+/Ca2+ exchanger (NCX1) by opening plasma membrane KATP channels and activating the NO/cGMP/PKG signaling pathway.
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Affiliation(s)
- Keisuke Iguchi
- Department of Internal Medicine III (Cardiology), Hamamatsu University School of Medicine, Hamamatsu, 431-3192, Japan.,Division of Pharmacological Science, Department of Health Science, Hamamatsu University School of Medicine, 1-20-1 Handayama, Hamamatsu, 431-3192, Japan
| | - Masao Saotome
- Department of Internal Medicine III (Cardiology), Hamamatsu University School of Medicine, Hamamatsu, 431-3192, Japan
| | - Kanna Yamashita
- Division of Pharmacological Science, Department of Health Science, Hamamatsu University School of Medicine, 1-20-1 Handayama, Hamamatsu, 431-3192, Japan
| | - Prottoy Hasan
- Department of Internal Medicine III (Cardiology), Hamamatsu University School of Medicine, Hamamatsu, 431-3192, Japan
| | - Miyuki Sasaki
- Division of Pharmacological Science, Department of Health Science, Hamamatsu University School of Medicine, 1-20-1 Handayama, Hamamatsu, 431-3192, Japan
| | - Yuichiro Maekawa
- Department of Internal Medicine III (Cardiology), Hamamatsu University School of Medicine, Hamamatsu, 431-3192, Japan
| | - Yasuhide Watanabe
- Division of Pharmacological Science, Department of Health Science, Hamamatsu University School of Medicine, 1-20-1 Handayama, Hamamatsu, 431-3192, Japan.
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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] [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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The beneficial effect of repaglinide on in vitro maturation and development ability of immature mouse oocytes. In Vitro Cell Dev Biol Anim 2017; 53:626-631. [PMID: 28432599 DOI: 10.1007/s11626-017-0152-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [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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Mohammed Abdul KS, Jovanović S, Jovanović A. Exposure to 15% oxygen in vivo up-regulates cardioprotective SUR2A without affecting ERK1/2 and AKT: a crucial role for AMPK. J Cell Mol Med 2017; 21:1342-1350. [PMID: 28121062 PMCID: PMC5487919 DOI: 10.1111/jcmm.13064] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 11/15/2016] [Indexed: 11/28/2022] Open
Abstract
SUR2A is an 'atypical' ABC protein that forms sarcolemmal ATP-sensitive K+ (KATP ) channels by binding to inward rectifier Kir6.2. Manipulation with SUR2A levels has been suggested to be a promising therapeutic strategy against ischaemic heart diseases and other diseases where increased heart resistance to stress is beneficial. Some years ago, it has been reported that high-altitude residents have lower mortality rates for ischaemic heart disease. The purpose of this study was to determine whether SUR2A is regulated by mild-to-severe hypoxic conditions (15% oxygen; oxygen tension equivalent to 3000 m above sea level) and elucidate the underlying mechanism. Mice were exposed to either to 21% (control) or 15% concentration of oxygen for 24 hrs. Twenty-four hours long exposure to 15% oxygen decreased partial pressure of O2 (PO2 ), but did not affect blood CO2 (PCO2 ), haematocrit nor levels of ATP, lactate and NAD+/NADH in the heart. Cardiac SUR2A levels were significantly increased while Kir6.2 levels were not affected. Hypoxia did not induce phosphorylation of extracellular signal-regulated kinases (ERK1/2) or protein kinase B (Akt), but triggered phosphorylation of AMP activated protein kinase (AMPK). AICAR, an activator of AMPK, increased the level of SUR2A in H9c2 cells. We conclude that oxygen increases SUR2A level by activating AMPK. This is the first account of AMPK-mediated regulation of SUR2A.
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Affiliation(s)
- Khaja Shameem Mohammed Abdul
- Division of Molecular & Clinical Medicine, Ninewells Hospital & Medical School, University of Dundee, Dundee, UK
| | - Sofija Jovanović
- Division of Molecular & Clinical Medicine, Ninewells Hospital & Medical School, University of Dundee, Dundee, UK
| | - Aleksandar Jovanović
- Division of Molecular & Clinical Medicine, Ninewells Hospital & Medical School, University of Dundee, Dundee, UK
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