Stem cells can develop into many different cell types in the body during early life and growth. In many tissues they serve as a sort of internal repair system, dividing essentially without limit to replenish other cells as long as the person or animal is still alive. When a stem cell divides, each new cell has the potential either to remain a stem cell or become another type of cell with a more specialized function, such as a muscle cell, a red blood cell, or a brain cell. Without these cells human tissues could not survive and we would die when the first cells wore out.
Bone marrow stem cells from humans has restored the lost hearing and vision in embryonic guinea pigs.This may be the key to unlock the first step toward helping people. Another group of researchers grew functioning eyes in tadpoles using frog cells.
Stem cell research hold extraordinary promise for treating a wide range of deadly and disabling diseases that plague millions.
How did they grow hearing cells?
By cultivating stem cells into neuron-like cells in petri dishes and then harvesting and transplanted them into the inner ears of the guinea pigs within three months later, the animals appeared to have some hearing, The goal was to regrow the tiny hair cells that are essential for mammals to hear.
What damages these hair cells?
“When sensitive hair cells in the inner ear of humans and other mammals are killed — by loud noise, autoimmune attack, toxic drugs, or aging — the damage is permanent. Humans cannot naturally replace them, other animals like birds and reptiles can automatically regenerate hearing cells.
Michael Zuber and colleagues at the SUNY Upstate Medical University in Syracuse, New York, grew functioning eyes in blinded frog embryos using stem cells.
In frog usually stem cells only form skin when grown in vitro. Zuber’s team of researchers discovered thatby adding seven different stimulating genetic “factors” eye formation genes were turned on..
When they transplanted the transformed cells into frog embryos, the resulting tadpoles could see out of those eyes, Zuber told the meeting. Genetic tests showed that the stem cells had transformed, a process called differentiation, into many different cell types. all cell types needed for vision were formed again.
Excerpts courtesy of stemcells.nih.gov/info/basics
Excerpts courtesy of Rueters.com Stem cells restore hearing, vision in animals
– Maggie Fox, Health And Science Editor Reuters– Wed Nov 19, 2008.
Image courtesy of csa.com/discoveryguides/stemcell/pluri