A Fix for Muscle Mutations

What am I looking at?

This is an image of muscle fibers that were derived from human induced pluripotent stem cells (iPSCs) and grown in a lab. The scientists treated cells from a patient with DMD to fix their mutation and restore the dystrophin protein they were missing. After treatment, the cells were visualized. The nuclei of the muscle cells are blue (1). The muscle cells are labeled with myosin protein in red (3). The cells with dystrophin protein present in them are green (2). And cells that are yellow or orange (4) have a combination of both dystrophin and myosin in them.

Biology in the background

DMD is a rare, degenerative, and debilitating disease that predominantly affects boys. It is caused by a mutation in the gene that codes for the dystrophin protein, rendering it nonfunctional. Dystrophin is a protein in muscle cells involved in protecting the cell membrane structure. Without it, muscle cells cannot function properly, causing progressively worsening muscle weakness and ultimately death.

The muscle cells in this image are derived from iPSCs from a patient with DMD who had been treated with a CRISPR Cas9-based gene therapy to repair the mutation in the dystrophin gene. This treatment resulted in functional dystrophin production in these cells. The result suggests that this may be a promising treatment for the subset of DMD patients (roughly 60% of them) who have mutations in a specific gene region.

Human muscle cells are large cells, with a diameter of up to 100 micrometers, or slightly larger than the width of a human hair, and they can grow up to 12 centimeters long (almost 5 inches).

Technique

This image was created using confocal microscopy.