Investigating the role of microRNAs during multiciliated brain tissue differentiation

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

Buenos Aires

Congreso; Latin American Society for Developmental Biology; 2019

LASDB

The choroid plexus (CP)/ependyma are essential tissues that maintain the brainhomeostasis by generating the cerebrospinal fluid and promoting its circulation, providingsignaling space and anatomical support throughout development. Despite the importantfunction of these multiciliated epitheliums (MEs), little is known about how theirdifferentiation is regulated.Using in situ hybridizations, we found that several members of miR-34/449, an essentialvertebrate microRNA family, are highly expressed in the CP. By using qRT-PCR, wefound that miR-34/449 family member miR449a is expressed throughout CP development,from E13.5 to P30.miR-34/449 is known to play important roles in the regulation of multiciliated cells in therespiratory tract and the oviduct. In order to investigate a possible role of miR-34/449 onCP?s ME differentiation, we studied the expression of different CP markers in a miR-34/449 KO mouse model. Using qRT-PCR, we found that the expression of the apicalmembrane marker AQP1 was completely de-regulated in adult CPs of miR-34/449 KOmice, suggesting a role in the differentiation of the ME. Moreover, the expression ofLHX2, a transcription factor whose inhibition is necessary for the early specification ofCP, was also abnormal in miR-34/449 KO mice.Altogether, these results are consistent with an important role of miR-34/449 on CPdevelopment. Further studies are necessary to dissect the regulatory functions of themiR-34/449 family during CP differentiation.