from the Massachusetts Eye and Ear Center have
identified key cells present in the human ear.
- These LDR5+ cells are capable of getting
converted into hair cells upon treatment with specific drug combinations.
- The regeneration of these hair cells
could reverse hearing loss, providing possible therapeutic advancements.
sensory cells called hair cells in the ear aid in our ability to hear. They
convert the sound vibrations into electrical signals that travel through the
nerves to the brain. When these hair cells are damaged due to medication,
noise, advanced age or even injury, it leads to profound hearing loss. Humans
cannot regrow these cells; 5 % of the population suffer from hearing loss due
to this reason. Advancements in medical science have now shown that there could
be a potential form of therapy to reverse this condition.
a study published in the journal Cell Reports
, scientists describe a
method to convert inner ear cells into hair cells, thus providing a possible
solution to certain forms of hearing loss.
‘Hearing Loss can soon be reversed using drug therapies that convert LGR5+ cells into hair cells.’
research team from Massachusetts Eye and Ear in 2013 showed that they could
regenerate hair cells successfully by altering the inner cells of the ear and
thus aid in the partial restoration of hearing. The only limiting factor in
this study was that the number of inner ear cells that could be converted into
hair cells was restricted.
research team from Massachusetts Institute of Technology, Massachusetts Eye and
Ear and Brigham and Women's Hospital has found that LGR5+ cells could be
- Increased in
number- a process known as cell augmentation
- Converted into
could be used to restore hearing loss among individuals who have lost their
hearing due to damage to hair cells. The method of cell augmentation yielded
more than 11,500 hair cells from a single mouse while earlier efforts without
cell augmentation produced only 200 hair cells.
Director of the Tillotson Cell Biology Unit at Massachusetts Eye and Ear, Dr.
Albert Edge said that the scientists were able to show that increasing the
expression of LGR5-expressing cells and inducing them to yield hair cells could
soon be an effective means of therapy for hearing loss.
Stem Cells in the Ear
current study to augment the LGR5 cells originated from an earlier study
conducted by the same scientists that showed the presence of stem cells in the
ear. In the previous study, the scientists found that
- Certain cells
identified in the ear produced a protein called LGR5.
- The same cells
were also found in the intestinal stem cells and were involved in the
replacement of the intestinal cells every eight days.
- The ability of
these cells to regenerate new intestinal cells was studied along with
their possible ability to regenerate hair cells.
- The scientists
were successful in inducing these cells (stimulated by the use of specific
drugs) to grow into hair cells in animal studies through the Wnt pathway.
understanding gained in the previous study was utilized in the current study,
- The LGR5+ cells
were extracted from the inner ear of mice.
- These cells were
then treated to certain combination of drugs as well as growth factors to
make them multiply.
- After the cells
increased in number, they were treated to another combination of drugs
which induced them into developing into hair cells.
study aided in converting the LGR5+ cells into hair cells
and identified the different drugs and the drug combination that could be used
to increase the number of cells and to convert the cells into hair cells
Edge further stated that the study could be used to repair critical damages to
the ear and that the clues provided by this study could be used to improve drug
therapy for hearing loss.
Hearing Loss and Its
is a vital means of communication among humans; hence the loss of hearing
especially among the elderly due to loss of hair cells, is a difficult aspect
to come to terms with. It alienates the elderly as they begin to restrict their
social interactions, with feelings of loneliness and despair setting in.
Hearing loss is prevalent among children as well, reinforcing the urgency to
address the problem.
to data provided by the Centers for Disease Control and Prevention (CDC) in
2007, there were 36 million American adults who suffered from hearing loss.
children, CDC estimates suggest that for every 1000 babies, two to three have a
detectable hearing loss, which translates into difficulties in cognitive
development, speech, language and social behavior.
study is a comprehensive step towards eliminating hearing loss in humans. The
study has identified the cells which could be targeted for therapy, their
pathways as well as the drug combinations that are effective in the
transformation process. This knowledge could be used to improve treatment for
hearing loss using specific drug therapy.
- Hair Cell Regeneration and Hearing Loss - (https://report.nih.gov/NIHfactsheets/ViewFactSheet.aspx?csid=94)
- Noise-Induced Hearing Loss - (https://www.nidcd.nih.gov/health/noise-induced-hearing-loss)