Stem cell transplantation into mouse cochlea may impact future hearing loss therapies

Jun 26, 2012

Researchers in Japan who evaluated the risks and efficacy of transplanting two varieties of stem cells into mouse cochlea have concluded that both adult-derived induced pluripotent stem (iPS) cells and mouse embryonic stem (ES) cells demonstrate similar survival and neural differentiation capabilities. However, there is a risk of tumor growth associated with transplanting iPS cells into mouse cochleae. Given the potential for tumorigenesis, they concluded that the source of iPS cells is a critical issue for iPS cell-based therapy.

Their study is published in a recent issue of Cell Transplantation (21:4), now freely available online.

"Hearing loss affects millions of people worldwide," said Dr. Takayuki Nakagawa of the Department of Otolaryngology, Graduate School of Medicine, Kyoto University, Japan. "Recent studies have indicated the potential of stem-cell based approaches for the regeneration of and associated auditory primary neurons. These structures are essential for hearing and defects result in profound hearing loss and deafness."

The authors noted that have previously been identified as promising candidates for transplantation, however they have also been associated with and ethics issues. Consequently, this study compared the survival and capabilities of ES and three clones of mouse iPS cells.

"Our study examined using induced generated from the patient source to determine if they offer a promising alternative to ES cells," explained Dr. Nakagawa. "In addition, the potential for tumor risk from iPS cells needed clarification."

Four weeks after transplantation, the researchers found that the majority of cochleae that had been transplanted exhibited the settlement of iPS or ES-derived neurons. However, there was a difference in the number of cells present based on cell lines. They noted that the number of cells able to be transplanted into cochleae is limited because of the cochleae's tiny size. Thus, the number of settled cells is low.

They also noted the formation of a teratoma (encapsulated tumor) in some cochlea after transplantation with one group of iPS cells.

"To our knowledge, this is the first documentation of teratoma formation in cochleae after ," said Dr. Nakagawa.

The researchers concluded that the teratoma formation in one iPS cell line indicated the necessity for selecting appropriate iPS cell lines for avoiding . They also noted the need for developing methods to eliminate undifferentiated cells after neural induction in order to establish safe iPS-based therapy for the inner ear.

"While this study did not look at the ability of the transplanted cells to repair hearing loss, it does provide insight into the survival and fate of transplanted cells. It highlights the importance of factors such as knowing the original source of the cells and their degree of undifferentiation to enable the cells to be ranked in order of their likelihood of forming tumors" said Dr. John Sladek, professor of neurology and pediatrics at the University of Colorado School of Medicine.

Explore further: DNA may have had humble beginnings as nutrient carrier

More information: Nishimura, K.; Nakagawa, T.; Sakamoto, T.; Ito, J. Fates of murine pluripotent stem cell-derived neural progenitors following transplantation into mouse cochleae. Cell Transplant. 21(4):763-771; 2012.

add to favorites email to friend print save as pdf

Related Stories

Cells derived from different stem cells: Same or different?

May 02, 2011

There are two types of stem cell considered promising sources of cells for regenerative therapies: ES and iPS cells. Recent data indicate these cells are molecularly different, raising the possibility that cells derived from ...

Stem cells reverse disease in a model of Parkinson's disease

May 16, 2011

In a new study to be published in the Journal of Clinical Investigation, researchers compared the ability of cells derived from different types of human stem cell to reverse disease in a rat model of Parkinson disease and id ...

Not all cellular reprogramming is created equal

Dec 01, 2011

Tweaking the levels of factors used during the reprogramming of adult cells into induced pluriopotent stem (iPS) cells greatly affects the quality of the resulting iPS cells, according to Whitehead Institute researchers.

Recommended for you

Research helps identify memory molecules

11 hours ago

A newly discovered method of identifying the creation of proteins in the body could lead to new insights into how learning and memories are impaired in Alzheimer's disease.

Computer simulations visualize ion flux

12 hours ago

Ion channels are involved in many physiological and pathophysiological processes throughout the human body. A young team of researchers led by pharmacologist Anna Stary-Weinzinger from the Department of Pharmacology ...

Neutron diffraction sheds light on photosynthesis

12 hours ago

Scientists from ILL and CEA-Grenoble have improved our understanding of the way plants evolved to take advantage of sunlight. Using cold neutron diffraction, they analysed the structure of thylakoid lipids found in plant ...

DNA may have had humble beginnings as nutrient carrier

Sep 01, 2014

New research intriguingly suggests that DNA, the genetic information carrier for humans and other complex life, might have had a rather humbler origin. In some microbes, a study shows, DNA pulls double duty ...

Central biobank for drug research

Sep 01, 2014

For the development of new drugs it is crucial to work with stem cells, as these allow scientists to study the effects of new active pharmaceutical ingredients. But it has always been difficult to derive ...

User comments : 0