Cellular mechanisnm that mediate the collecting duct (CD) formation during post-natal renal development

GUAYTIMA EV; BRANDAN YR; VALLS J; FAVALE NO; SANTACREU BJ; MARQUEZ MG

CABA

Congreso; II Reunión Conjunta de Sociedades de BioCiencias.; 2017

SAIB-SAIC-SAI-SAA-SAB-SAB-SAFE-SAFIS-SAH-SAP

In mammals, nephrogenesis is completed postnatally. In previous works, we have shown that primary cultures of renal papillary CD cells from neonatal rats, display a phenotype of mi- gratory sheet of epithelial cells. Now, we investigated the mecha- nisms involved in the postnatal CD formation. In order to evaluate the differentiation degree of primary cultured CD cells, the ability of DBA (a CD marker) and BSL-I (a renal interstice marker)-bind- ing, together with the expression of epithelial (cytokeratin-7, CK7, and adherens junction proteins, AJ) and mesenchymal biomarkers (vimentin and α-smooth muscle actin, α-SMA) were analyzed by im- muno uorescence. We observed the coexistence of CD cells with different degree of differentiation in the same colony. Those of high- er differentiation were DBA ( ), intermediate laments CK7 ( ) and exhibited assembled AJs. While those of lower differentiation were vimentin ( ), cytosolic CK7 ( ), DBA/BSL-I ( ), only BSL-I ( ), or DBA/BSL-I (-), and they lacked mature AJs. The analysis of over- lapping cells showed a mesenchymal phenotype. 3D reconstruc- tions and xz pro les of confocal microscopy images showed that they were located adjacent to or below the plane of the colonies. Cell behavior studies in real time by phase contrast microscopy re- vealed that they could be inserted between the CD cells from the basal plane through a mesenchymal-epithelial transition, acquiring the epithelial phenotype of the cells that surround them. Taking into account the above results, we suggest that overlapping cells could originate in situ through an epithelial-mesenchymal transition from CD cells. Therefore, our results suggest the existence of a ?dynamic balance? between CD and mesenchymal cells, strongly displaced towards the former. Most likely, between CD cells and the mesenchymal cells generated de novo, the mutual induction described above could occur.