Video Transcript
Macular degeneration is when the
light-sensitive cells in the center of your eye stop working. Which of the following best
explains how stem cells could be used to treat someone with macular
degeneration? (A) Stem cells can be stimulated to
differentiate into light-sensitive cells to replace the damaged ones. (B) Stem cells can be used to
create an entire eyeball and replace the eye of someone with this condition. (C) Stem cells can be inserted into
the eye to fix the damaged cells. (D) Stem cells can stimulate the
immune response to repair the damaged cells. Or (E) stem cells cannot be used to
treat this condition.
Let’s remove the multiple-choice
options for now and explore how stem cells can be used to treat conditions like
macular degeneration. You may recall that organs such as
the eye contain tissues made of specialized cells that are adapted for their
function. For example, the retina tissue of
the eye is made of cells that are specialized by being sensitive to light. We say that specialized cells such
as these are differentiated because they’re committed to being specialized for their
function. Not all cells are differentiated
however. Some cells — which can be found in
developing human embryos, in the umbilical cord, in some tissues of the developed
human body or that can be artificially made from reprogrammed skin cells — are
undifferentiated, and these are known as stem cells.
Because they’re not specialized,
stem cells are capable of differentiating into a range of different cell types. This is how all our tissues and
organs are formed during development and how they repair themselves if they become
damaged during adult life. Stem cells are also very useful to
us because they can be used in medicine and research. This question is about macular
degeneration, which is one of the conditions that could be treated using stem
cells. The macula is the region of the
retina shown in orange on this diagram. A macular degeneration is when the
light-sensitive cells that make up this region gradually stop working over time,
leading to sight loss, particularly in the center of the sufferer’s field of
vision.
Fortunately, stem cells show great
potential for treating macular degeneration. Scientists could modify stem cells
with specific proteins called transcription factors, which would stimulate them to
differentiate into light-sensitive cells. These healthy cells could then be
inserted into the macula to replace the damaged ones.
Now we can return to the
multiple-choice options and answer this question. The statement that best explains
how stem cells could be used to treat someone with macular degeneration is (A). Stem cells can be stimulated to
differentiate into light-sensitive cells to replace the damaged ones.
