Human oocytes express ATP-sensitive K+ channels

Du, Qingyou; Jovanović, Sofija; Sukhodub, Andriy; Barratt, Evelyn; Drew, Ellen; Whalley, Katherine; Kay, Vanessa; McLaughlin, Marie; Telfer, Evelyn E.; Barratt, Christopher L. R.; Jovanović, Aleksandar

doi:10.1093/humrep/deq245

Cited by 17 publications

(26 citation statements)

References 38 publications

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“…These differences imply that drugs may have distinct abilities to affect K ATP channels in diverse tissues depending on the type of SUR expressed [20]. Gli binds to every type of SUR and therefore inhibits the activity of all known K ATP channels [33]. When we assayed the effect of Gli on MDA-MB-231 cell proliferation, results showed that Gli inhibits clonogenic ability in a concentration-dependent way, with an increment in population doubling time.…”

Section: Discussionmentioning

confidence: 99%

Glibenclamide inhibits cell growth by inducing G0/G1 arrest in the human breast cancer cell line MDA-MB-231

Núñez

Medina

Cricco

et al. 2013

BMC Pharmacol Toxicol

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BackgroundGlibenclamide (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.ResultsThe 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.ConclusionsOur 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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Section: Discussionmentioning

confidence: 99%

Glibenclamide inhibits cell growth by inducing G0/G1 arrest in the human breast cancer cell line MDA-MB-231

Núñez

Medina

Cricco

et al. 2013

BMC Pharmacol Toxicol

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“…ATP-sensitive potassium (K + ATP ) channels have been found in human, bovine, and porcine oocytes at various maturational stages [Du et al 2010]. In any tissues where they are expressed, K + ATP channels regulate membrane potential and, at the same time, affect intracellular calcium levels (reviewed by [Nichols 2006]).…”

Section: Mammalsmentioning

confidence: 99%

Ion currents modulating oocyte maturation in animals

Tosti

Boni

Gallo

et al. 2013

Systems Biology in Reproductive Medicine

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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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“…In this study, we have examined whether a relationship exists between markers of vascular function and Ct for blood GAPDH in humans. Although Ct value is affected by many factors, it is recognized that this value is mostly an indicator of a measured gene mRNA level . Basal perfusion, recovery PORH, and FMD are all parameters of vascular function that are known to be dependent on the integrity of the vascular endothelium.…”

Section: Discussionmentioning

confidence: 99%

“…The vacutainer was placed in a sealed transport plastic bag containing ice and sent immediately to the laboratory for determination of mRNA levels by real‐time RT‐PCR test. Real‐time RT‐PCR was performed using primers and controls as we previously described on other human samples . Threshold cycle values (C t ) were directly obtained by this methodology …”

Section: Methodsmentioning

confidence: 99%

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Real‐Time RT‐PCR Ct Values for Blood GAPDH Correlate with Measures of Vascular Endothelial Function in Humans

Khan

Choong

et al. 2013

Clinical Translational Sci

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IntroductionEarly changes in the normal functioning of the endothelium are key initiating factors in the development and progression of atherosclerosis and they are present well before the presentation of clinical symptoms. To date, there is a wide range of methods in use to assess endothelial function, each with its own advantages and limitations.1 For diagnostic purposes and for indications of progression and outcomes of disease, a methodology measuring a biomarker in the blood would be convenient. Measurement of mRNA levels could provide a good option as: (1) measurement of this parameter requires small amounts of blood and (2) real-time RT-PCR to measure mRNA is relatively straightforward and technically less challenging than techniques used to measure protein levels.Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is a highly expressed multifunctional protein with diverse physiological functions and activities involved in glycolysis, transcriptional and posttranscriptional gene regulation, vesicular transport, receptor-mediated cell signaling, chromatin structure, and the maintenance of DNA integrity. GAPDH activity is regulated by many factors, one of them being nitric oxide (NO).2 NO synthesized and released from vascular endothelium is an important regulator of vascular tone.3 It has been reported that NO can either inhibit or activate GAPDH in different cell types. 4,5 As it is known that NO derived from the vascular endothelium targets blood cells, 6 it is possible that GAPDH activity could be regulated by endothelial NO. If so, then GAPDH activity in blood cells could be reflective of vascular endothelial NO production and thus indicative of endothelial function in physiological and pathophysiological conditions.Although there was no previous work to support our hypothesis, we decided to explore the potential link between vascular endothelial function and GAPDH mRNA level in the blood in healthy volunteers. We found that real-time RT-PCR Ct values of blood GAPDH correlate with vascular function in healthy subjects. This suggests that GAPDH mRNA level could be a potential biomarker of vascular endothelial function. Subjects and Methods SubjectsSeventy-five young healthy volunteers (41 males, 34 females) were recruited for the study. None of the subjects were smokers, used any medication, or had a history of any symptomatic vascular disease(s). Subject characteristics are shown in Table 1. The study was approved by the Tayside Committee on Medical Research Ethics and written informed consent was obtained from each subject before participation in the study. All subjects attended for one single visit lasting up to 3 hours during which a blood sample was taken and vascular function tests performed (see below). Vascular assessments were conducted in a blood flow laboratory at a temperature of 23°C after 10 minutes of acclimatization. Subjects were asked to refrain from food and drink for at least 2 hours beforehand and also to refrain from physical activity for 1 day before their visit. RNA preparation and ...

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Human oocytes express ATP-sensitive K+ channels

Abstract: In conclusion, mammalian oocytes express K(ATP) channels. This opens a new avenue of research into the complex relationship between metabolism and membrane excitability in oocytes under different conditions, including conception.

Cited by 17 publications

References 38 publications

Glibenclamide inhibits cell growth by inducing G0/G1 arrest in the human breast cancer cell line MDA-MB-231

Glibenclamide inhibits cell growth by inducing G0/G1 arrest in the human breast cancer cell line MDA-MB-231

Ion currents modulating oocyte maturation in animals

Real‐Time RT‐PCR Ct Values for Blood GAPDH Correlate with Measures of Vascular Endothelial Function in Humans

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