Periodic Reporting for period 1 - TiGER (Titin can govern epigenetic remodelling)
Berichtszeitraum: 2022-01-01 bis 2023-12-31
Heart diseases are the leading cause of death in Western countries for both men and women. These diseases are often irreversible and get worse over time. One of the reasons behind these diseases is the way the heart contracts and the tension in the heart tissue.
There is a protein called titin, which is very large and present in all muscle cells. Titin plays a major role in determining the tension in the heart tissue. Titin has a special part called N2B that acts like a spring and is only found in heart cells. When the N2B part is missing in mice, their hearts become even stiffer and smaller. We still have many questions about how the N2B part affects heart cells. We used cardiac cell of human origin to study the function of the N2B sequence in titin. We removed the N2B sequence from the gene in the cells and studied the effects on contraction, expression of genes and cell structure.
This research is important to understand how the N2B part of titin affects the human heart in both normal and diseased conditions and therefore will help designing new therapeutic strategies to combat cardiac diseases.
There is a protein called titin, which is very large and present in all muscle cells. Titin plays a major role in determining the tension in the heart tissue. Titin has a special part called N2B that acts like a spring and is only found in heart cells. When the N2B part is missing in mice, their hearts become even stiffer and smaller. We still have many questions about how the N2B part affects heart cells. We used cardiac cell of human origin to study the function of the N2B sequence in titin. We removed the N2B sequence from the gene in the cells and studied the effects on contraction, expression of genes and cell structure.
This research is important to understand how the N2B part of titin affects the human heart in both normal and diseased conditions and therefore will help designing new therapeutic strategies to combat cardiac diseases.
To study this in human heart cells, I used a special technique called CRISPR/Cas9 gene-editing to remove the N2B part from human stem cells. These stem cells can turn into heart cells, so we grew them in the lab and observed how they developed. The cells without the N2B part grew normally and had the same amount and location of the titin protein as the normal cells, as we saw in tests with gels and staining.
However, the absence of N2B affected the nucleus. I measured the levels of two proteins called lamin A/C and the tension inside the nucleus using special probes. I found that the cells without N2B had less lamin A and more lamin C, and the tension inside the nucleus was higher than in the normal cells.
In addition, I made small heart tissues in the lab to test how well they contracted. The tissues without N2B produced more force and contracted and relaxed faster than the normal tissues.
These results have been presented at scientific conferences and a scientific publication is under preparation.
However, the absence of N2B affected the nucleus. I measured the levels of two proteins called lamin A/C and the tension inside the nucleus using special probes. I found that the cells without N2B had less lamin A and more lamin C, and the tension inside the nucleus was higher than in the normal cells.
In addition, I made small heart tissues in the lab to test how well they contracted. The tissues without N2B produced more force and contracted and relaxed faster than the normal tissues.
These results have been presented at scientific conferences and a scientific publication is under preparation.
This work links titin to the nucleus and provides novel insights to understand how titin stiffness can affect gene expression and organization. Potential impacts of this work include improved understanding of how stiffness mediates disease states. Similar studies could be performed to characterize other regions of titin.