Cell organelle-based analysis of cell chirality

Cell polarity is essential for endothelial function, involving apicobasal, front-rear, and left-right (L-R) orientation. While apicobasal and front-rear polarity are well understood, the L-R axis remains less explored. Previous studies have shown that endothelial cells display a directional bias on ring-shaped micropatterns. However, the origin of this bias is unclear. No prior work had resolved whether this bias arises from internal organelle positioning. Researchers have not yet determined if this L-R bias is intrinsic or influenced by external cues. This gap motivated further investigation into the mechanisms behind cell chirality. The study aims to clarify how organelle positioning contributes to L-R polarity. Understanding this could improve in vivo analysis of cell chirality.

This study aims to investigate the left-right (L-R) bias in endothelial cells by analyzing the positioning of the cell centroid relative to the nucleus-centrosome axis. The researchers want to determine if this bias is intrinsic or influenced by external factors. They focus on individual cells to avoid confounding variables from cell-cell interactions. The goal is to establish a method for measuring cell chirality in situ. Current methods rely on isolated cells in engineered platforms, which may not reflect in vivo conditions. The study seeks to confirm if organelle positioning contributes to L-R bias. By using micropatterns, the researchers can control the cell environment. This approach allows for precise measurement of cell chirality at the single-cell level.

The researchers used ring-shaped micropatterns to culture individual endothelial cells. They analyzed the position of the cell centroid relative to the nucleus-centrosome axis. Fluorescent markers were used to visualize the nucleus and centrosome. The study measured the angle between the centroid and the nucleus-centrosome axis. Statistical analysis was performed to assess the directionality of the bias. The researchers compared results from multiple cells to ensure reproducibility. They validated their findings using alternative methods of chirality assessment. This approach allowed for a detailed examination of organelle positioning.

The study found that endothelial cell centroids preferentially aligned to the right side of the nucleus-centrosome axis. This rightward bias was consistent across multiple cells and micropatterns. The results matched those obtained from other chirality assessment methods. The bias was not affected by external mechanical cues in the micropattern setup. The researchers observed no significant variation in the direction of the bias. The alignment suggests an intrinsic left-right asymmetry in organelle positioning. This finding supports the idea that cell chirality is an internal property. The results provide a new method for measuring chirality in situ.

The study suggests that endothelial cells have an intrinsic left-right bias in organelle positioning. This bias is consistent with previously reported cell chirality. The findings support the use of the nucleus-centrosome axis as a reference for measuring chirality. The method allows for in situ analysis, which is not possible with current in vitro techniques. The results indicate that cell chirality is not dependent on external mechanical cues. The study confirms that the bias is reproducible across multiple cells. This approach provides a reliable way to assess cell chirality at the single-cell level. The findings may improve understanding of cell polarity in vascular systems.