Mouse Nephron Progenitor Cells

Long-Term Clonal Expansion of Nephron Progenitor Cells via p38 and YAP Modulation

The limited expansion capacity of nephron progenitor cells (NPCs) restricts kidney research and disease modeling. To address this, Huang et al. developed mNPSR-v2, a chemically defined medium optimized for long-term clonal expansion of mouse NPCs (mNPCs) in 2D culture. Compared to the original mNPSR, mNPSR-v2 incorporates four key inhibitors: p38 MAPK (SB202190), Notch (DAPT), TGF-β (A83-01), and BMP (LDN193189), alongside adjusted CHIR99021 concentration. Among these, SB202190 was critical for maintaining the SIX2⁺/PAX2⁺ NPC pool (Fig. 1B, 1C), while DAPT prevented spontaneous differentiation.

mNPCs cultured in mNPSR-v2 proliferated stably with homogeneous morphology (Fig. 1D, 1E) and uniform expression of NPC markers (Fig. 1F, 1G). Withdrawal of any single component compromised self-renewal. Functionally, cultured mNPCs retained robust nephrogenic potential. In the spinal cord induction assay, they formed tubule-like structures containing PODXL⁺ glomeruli, LTL⁺ proximal tubules, and CDH1⁺ distal tubules (Fig. 1H, 1I). They also generated nephron organoids in defined media. drove ureteric bud branching morphogenesis, and differentiated into nephrons when transplanted in vivo.

Clonal expansion from single cells achieved 60%-70% efficiency (Fig. 1J-1N). Bulk RNA sequencing confirmed that cultured mNPCs transcriptionally resembled primary E11.5-E13.5 NPCs (Fig. 1O, 1P). This platform enabled robust derivation of mNPC lines from isolated metanephric mesenchyme or whole embryonic kidneys across multiple mouse strains, providing a scalable resource for kidney development and disease studies.