Investigating the role of microRNAs during choroid plexus/ ependyma differentiation

PAULA AGUIRRE; PAULA GONZALEZ; NATHALIE SPASSKY; JUAN PABLO FEDEDA

Buenos Aires

Congreso; Xth Meeting of the Latin American Society for Developmental Biology; 2019

The choroid plexus (CP)/ependyma are essential tissues that maintain the brainhomeostasis by generating the cerebrospinal fluid and promoting its circulation,providing signaling space and anatomical support throughout development.Despite the important function of these multiciliated epitheliums (MEs), little isknown about how their differentiation is regulated.Using in situ hybridizations, we found that several members of miR-34/449, anessential vertebrate microRNA family, are highly expressed in the CP. By usingqRT-PCR, we found that miR-34/449 family member miR449a is expressedthroughout CP development, from E13.5 to P30.miR-34/449 is known to play important roles in the regulation of multiciliated cellsin the respiratory tract and the oviduct. In order to investigate a possible role ofmiR-34/449 on CP?s ME differentiation, we studied the expression of different CPmarkers in a miR-34/449 KO mouse model. Using qRT-PCR, we found that theexpression of the apical membrane marker AQP1 was completely de-regulated inadult CPs of miR-34/449 KO mice, suggesting a role in the differentiation of theME. Moreover, the expression of LHX2, a transcription factor whose inhibition isnecessary for the early specification of CP, was also abnormal in miR-34/449 KOmice.Altogether, these results are consistent with an important role of miR-34/449 on CPdevelopment. Further studies are necessary to dissect the regulatory functions ofthe miR-34/449 family during CP differentiation.