Human pluripotent stem cells can generate a diverse type of cells, but few methods have been developed to differentiate them into renal lineages.

Now, a team of American scientists has successfully converted some stem cells into renal tubular cells, which is a significant advance for regenerative medicine. It implicates that, in place of dialysis and transplant, the treatment of kidney disease can incorporate the rebuilding or repair of tissues and organs.

The study, published in the Journal of American Society of Nephrology, is the result of five years of work that tested strategies with the aim of persuading embryonic stem cells, particularly human ones and human pluripotent stem cells, into kidney cells for renal regeneration.

According to the principal author of the study, Dr. Albert Q. Lam:

“Our objective is to develop a simple, efficient and reproducible method of differentiating human pluripotent stem cells into the cells of the intermediate mesoderm—the earliest tissue in a developing embryo that forms the kidneys.”

What researchers have observed is that the treatment of human pluripotent cells taken from skin biopsies with distinct chemical components results in the differentiation of mesoderm cells, which are expressed by the genes PAX2 and LHx1, with almost 100 percent efficacy.

The differentiated cells express various genes from the intermediate mesoderm and spontaneously can form tubular structures, which show the markings of mature renal tubules. The authors can then differentiate even more in the cells that show SIX2, Sall1 and WT1, important markers in metanephrogenic blastema. This is a critical stage for the differentiation of the kidneys which contains the population of progenitor cells where almost all of the epithelial cells of the kidneys are formed.

The cells also continue to act like kidney cells when they are transplanted into an adult rat or into the kidneys of rat embryos. Hopefully, one day scientists will be able to create functional kidney tissues that are one hundred percent immunocompatible for patients.