Expression and localization of DAB1 and Reelin during normal human kidney development.

Aim To explore the spatial and temporal expression patterns of DAB1 and Reelin in the developing and postnatal healthy human kidneys as potential determinants of kidney development. Methods Paraffin embedded fetal kidney tissue between the 13/14th and 38th developmental weeks (dw) and postnatal tissue at 1.5 and 7 years were stained with DAB1 and Reelin antibodies by double immunofluorescence. Results During the fetal kidney development and postnatal period, DAB1 and Reelin showed specific spatial expression pattern and diverse fluorescence intensity. During the fetal period, DAB1 was strongly expressed in the distal convoluted tubules (DCT), with strong reactivity, and diversely in the proximal convoluted tubules (PCT) and glomeruli. In the postnatal period, DAB1 expression decreased. The strongest Reelin expression in early fetal stages was observed in the PCT. In the postnatal period, Reelin expression decreased dramatically in all observed structures. These two markers were colocalized during early developmental stages, mostly in PCT, DCT, and podocytes. Conclusion The appearance of DAB1 and Reelin during fetal kidney development confirms their potential significant role in the formation of kidney structure or function. High DAB1 expression in the DCT implies its regulatory rolo in tubular formation or function maintenance during development. Reelin was highly expressed in human kidneys at early fetal stages, mostly in the PCT while at late I stages and postnatal period its expression decreased.