Tokyo: Researchers from the National Institute for Physiological Sciences in Japan say that they have gained success in growing functional kidneys using some donor stem cells inside rats. This development can have important positive implications for human organ transplantation.
According to the study published in Nature Communications, kidney transplant is the only hope for the patients suffering from end-stage kidney disease to regain quality of life.
Despite that, a lot of these patients will never undergo transplant surgery because of a chronic dearth of donor kidneys, said the researchers.
In the US alone, 95,000 patients are on the waiting-list for donor kidney which shows the huge gap between the demand and supply, they added.
Therefore, researches are going on to find methods to grow functional organs like kidney, outside the human body. One such method, called blastocyst complementation, has already shown promising results.
For blastocyst complementation, researchers take blastocysts—the clusters of cells formed several days after egg fertilization—from mutant animals that miss specific organs and inject them with stem cells from a normal donor, not necessarily from the same species. The stem cells then differentiate to form the entire missing organ in the animal. The new organ has the same characteristics as that of the original stem cell donor, and can thus potentially be used for transplantation.
Teppei Goto, the lead author of the study said, “We previously used blastocyst complementation to generate rat pancreas in a pancreatic mutant mice. Therefore, we decided to investigate whether the method could be used to generate functional kidneys, which would have much greater application in regenerative medicine owing to the high donor demand.”
The researchers have attempted to grow rat kidneys in mice earlier too but could not succeed because stem cells of rat did not differentiate into the two main types of cells required for the formation of kidneys.
But, when the reverse scenario was tried, mouse stem cells efficiently differentiated inside rat blastocysts, resulting in the basic form of a kidney.
The researchers told that after being implanted into pseudo-pregnant rats, the complemented blastocysts had matured into normal fetuses and more than 2/3rd of the rat neonates so resulted, contained kidney pair derived from mouse stem cells.
On further screening, it was found that all of the kidneys were structurally fine and at least half could potentially produce urine.
Masumi Hirabayashi, the corresponding author of the study said, “Our findings confirm that inter-specific blastocyst complementation is a viable method for kidney generation.” Therefore, “In the future, this approach could be used to generate human stem cell-derived organs in livestock, potentially extending the lifespan and improving the quality of life of millions of people worldwide,” Hirabayashi added.
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