Primary and Multipassage Culture of Human Fetal Kidney Epithelial Progenitor Cells

Abstract Homogeneous, well‐characterized cultures of kidney cells representative of defined cellular phenotypes comprising the developing and adult kidney provide important tools to investigate kidney biology. Further, the development of defined media for these culture systems provides opportunities to investigate the role of nutrients, hormones, and matrix components, as well as exogenous insults, in renal development, function, and toxicity. The current explosion in stem cell research has fueled an expanded effort to develop techniques to isolate and culture kidney progenitor and stem cells, which have the potential to treat various forms of renal disease. In this chapter, we outline methods to initiate and propagate long‐term cultures of highly homogeneous fetal kidney epithelial progenitor cells. By utilizing a low calcium‐containing serum‐free culture medium together with a set of defined hormones and extracellular matrix, kidney epithelial progenitor cells can be cultured for more than 60 population doublings without loss of growth potential or phenotypic signs of differentiation. The cultures appear to represent early kidney epithelial progenitors based on cellular marker expression. The cells express the mRNA encoding the embryonic kidney mesenchyme/epithelial marker PAX‐2, the stem cell protein CD133, the kidney embryonic progenitor protein CD24, as well as CD29 and CD44. The cells are negative for E‐cadherin when grown under low calcium conditions (