The function of Trim71 in supporting cell reprogramming and hair cell regeneration

Employing an organoid based assay, we show that lentiviral overexpression of human TRIM71 in stage P5 cochlear epithelial cells restores their capacity to proliferate and form hair cells. RNA-sequencing and cell-based assays reveal that similar to LIN28B, TRIM71 overexpression activates the expression of pro-growth genes and inhibits pro-differentiation genes resulting in the reprogramming of supporting cells into progenitor like cells. Cochlear epithelial cells isolated from stage P5 wild type mice were used to establish organoid cultures as previously described (DOI: 10.1073/pnas.2000417117). Before plating, equal amount of cells were infected with control lentivirus expressing mCherry only or lentivirus expressing human TRIM71 and mCherry. At 10 days of expansion, RNA was extracted and RNA samples were processed using Illumina's TruSeq stranded Total RNA kit, per manufacturer's recommendations, using the UDI indexes. The samples were sequenced on the NovaSeq 6000, paired end, 2x50 base pair reads. Three independent samples from three different animals were analyzed.