Functional analysis of cardiomyocytes carrying mutations in SCN5A gene
Linnoinen, Anna-Maria (2017)
Linnoinen, Anna-Maria
2017
Bioteknologian tutkinto-ohjelma - Degree Programme in Biotechnology
Lääketieteen ja biotieteiden tiedekunta - Faculty of Medicine and Life Sciences
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Hyväksymispäivämäärä
2017-02-24
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:uta-201703071231
https://urn.fi/URN:NBN:fi:uta-201703071231
Tiivistelmä
Background and aims: Heart function is based on electrochemical changes (action potentials) across the cardiomyocyte cell membranes. Action potentials induces the release of calcium ions from intracellular stores (sarcoplasmic reticulum), binding of calcium to sarcomeric proteins and finally in cardiac muscle contraction. The most important ions, which take part in the action potential generation, are sodium, calcium and potassium. The rapid flow of sodium ions into the cardiomyocytes causes the depolarization of the cell membrane.
SCN5A is the gene located on chromosome 3p21, and it encodes the pore-forming α-subunit of the voltage-gated sodium channel Nav1.5. Patients with these mutations in SCN5A gene have different inherited arrhythmia syndromes, such as congenital long QT syndrome (LQTS) and Brugada syndrome (BrS).
This work will focus on two different SCN5A mutations, I141V and R1913C. It has different aims: 1) Baseline beating characterization of cardiomyocytes carrying mutation in SCN5A. 2) To study drug responses of cardiomyocytes carrying mutation in SCN5A. 3) Image and analyse both visually and using the BeatView software SCN5A mutation -patient specific and wildtype (WT) iPSC -derived cardiomyocytes (CMs) 4) To get reliable data of SCN5A mutation -patient specific CMs visual inspection was used, if it is impossible to analyze signals with BeatView.
Methods: Two of cell lines were derived from patients with mutations in the SCN5A gene and they were compared to a control cell line from a healthy individual. Behavior of the cells were analyzed using videos of single dissociated beating cardiomyocytes of each cell line. Individuals carrying mutations in the SCN5A gene get arrhythmias during exercise. Adrenaline was used to replicate this phenomenon in vitro. Flecainide was used to study how it effects in good way to arrhythmic symptoms of the CMs. Analyzing and classification of CMs were studied both visually and using Beatview software.
Results: Beating frequency of cells with SCN5A mutations was higher than in control cells. Flecainide decreased beating frequency of all cell lines and made disease cells more regular. Adrenaline did not increase beating frequency in SCN5A cells as assumed most likely due to high baseline beating frequency. Similar beating behavior were obtained whether the analysis was done by visual analyzing or by using Beatview software.
Conclusions: SCN5A cells beating behaviors were more arrhythmic than control cells and beating frequencies was also higher than in control cells. Time cells were relaxed was shorter time than in control cells. Flecainide slowed down the beating frequency and increased time cells were relaxed in all cell lines.
SCN5A is the gene located on chromosome 3p21, and it encodes the pore-forming α-subunit of the voltage-gated sodium channel Nav1.5. Patients with these mutations in SCN5A gene have different inherited arrhythmia syndromes, such as congenital long QT syndrome (LQTS) and Brugada syndrome (BrS).
This work will focus on two different SCN5A mutations, I141V and R1913C. It has different aims: 1) Baseline beating characterization of cardiomyocytes carrying mutation in SCN5A. 2) To study drug responses of cardiomyocytes carrying mutation in SCN5A. 3) Image and analyse both visually and using the BeatView software SCN5A mutation -patient specific and wildtype (WT) iPSC -derived cardiomyocytes (CMs) 4) To get reliable data of SCN5A mutation -patient specific CMs visual inspection was used, if it is impossible to analyze signals with BeatView.
Methods: Two of cell lines were derived from patients with mutations in the SCN5A gene and they were compared to a control cell line from a healthy individual. Behavior of the cells were analyzed using videos of single dissociated beating cardiomyocytes of each cell line. Individuals carrying mutations in the SCN5A gene get arrhythmias during exercise. Adrenaline was used to replicate this phenomenon in vitro. Flecainide was used to study how it effects in good way to arrhythmic symptoms of the CMs. Analyzing and classification of CMs were studied both visually and using Beatview software.
Results: Beating frequency of cells with SCN5A mutations was higher than in control cells. Flecainide decreased beating frequency of all cell lines and made disease cells more regular. Adrenaline did not increase beating frequency in SCN5A cells as assumed most likely due to high baseline beating frequency. Similar beating behavior were obtained whether the analysis was done by visual analyzing or by using Beatview software.
Conclusions: SCN5A cells beating behaviors were more arrhythmic than control cells and beating frequencies was also higher than in control cells. Time cells were relaxed was shorter time than in control cells. Flecainide slowed down the beating frequency and increased time cells were relaxed in all cell lines.