Bridges to cross, burn, and mend: cells of renin lineage as podocyte progenitors

摘要

as researchers and physicians, we wish to unlock the secret key to regenerate our organs and heal all disease. This seems an almost impossible task if it comes to the kidney glomerulus because its constituents are highly specialized cells that communicate in a complicated fashion. The study by Pippin et al. (7), in a recent issue of The American Journal of Physiology-Renal Physiology, extends our knowledge in the context of cells of renin lineage (CoRL) transdifferentiation in glomerular disease models by suggesting a cell type that replaces dwindling podocytes. Podocytes (or visceral epithelial cells) are highly specialized cells entwining the glomerular capillaries. While the podocyte cell body sits above the glomerular basement membrane (GBM), its finger-like extensions form inter-digitating foot processes (FPs) with its neighbors. FPs are connected to each other via the slit diaphragm (SD), which forms an important barrier to the filtration of protein. FPs are known to be rich in actin filaments, and their zipper-like substructure is crucial for keeping the filtration barrier stable and filtering the blood properly (5).