Rapid and Efficient Methods for the Generation of Proximal Tubular-Like Cells

23 Rapid and Efficient Methods for the Generation of Proximal Tubular-Like Cells 

by treating CH1R99021-, FGF2-, and RA-induced FAX LHXL cells with FGF9 and activin A, differentiation into 81X2 SALLL cap mesenchyme nephron progenitorlike cells could be achieved (Fig. 23.1). These cells could be stained with LTL in response to Wnt signaling (Lam et al., 2014). 

STEM CELL-DERIVED RENAL CELLS AND PREDICTIVE RENAL IN VITRO MODELS 

Therefore, differences between properties of PTC in vivo in the normal adult kidney and in vitro properties of PTC and stem cell-derived proximal tubular-like cells may not just reflect dedifferentiation or lack of full terminal differentiation. Rather, altered marker expression patterns seem to be related to the biology of these cells and their response to altered conditions. It is important to keep in mind that human and animal PTC are probably always different under in vitro conditions (compared to the in vivo situation), unless the in vivo simation can be exactly mimicked. This is also important with respect to the interpretation of the differentiation status of stem cell-derived proximal tubular-like cells, as the expression of progenitor markers and markers specific for other renal cell types is normal under in vitro conditions, also in HPTC. For practical reasons we suggest to always compare stem cell-derived cells carefully to respective primary cells cultivated in vitro, which gives a realistic impression of the best possible differentiation state that can be achieved under the conditions used. In addition, rigorous functional tests (e.g., of transporter functions) are often more informative than marker expression patterns in terms of the applicability of stem cell-derived cells for drug screening. 

As mentioned previously, the marker expression patterns of hESC-derived HPTC-Uke cells were similar to those of HPTC cultivated in vitro (Narayanan et al., 2013). hi addition, hESC-derived HPTC-Uke cells formed simple epithelia with tight junctions and displayed a polarized morphology with an apical brush border (Narayanan et al., 2013). Both are typical 

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