Characterization of microRNAs Involved in Embryonic Stem Cell States

Abstract

Studies of embryonic stem cells (ESCs) reveal that these cell lines can be derived from differing stages of embryonic development. We analyzed common changes in the expression of microRNAs (miRNAs) and mRNAs in 9 different human ESC (hESC) lines during early commitment and further examined the expression of key ESCenriched miRNAs in earlier developmental states in several species. We show that several previously defi ned hESC-enriched miRNA groups (the miR-302, -17, and -515 families, and the miR-371-373 cluster) and several other hESC-enriched miRNAs are down-regulated rapidly in response to differentiation. We further found that mRNAs up-regulated upon differentiation are enriched in potential target sites for these hESC-enriched miRNAs. Interestingly, we also observed that the expression of ESC-enriched miRNAs bearing identical seed sequences changed dynamically while the cells transitioned through early embryonic states. In human and monkey ESCs, as well as human-induced pluripotent stem cells (iPSCs), the miR-371-373 cluster was consistently up-regulated, while the miR-302 family was mildly down-regulated when the cells were chemically treated to regress to an earlier developmental state. Similarly, miR-302b, but not mmu-miR-295, was expressed at higher levels in murine epiblast stem cells (mEpiSC) as compared with an earlier developmental state, mouse ESCs. These results raise the possibility that the relative expression of related miRNAs might serve as diagnostic indicators in defi ning the developmental state of embryonic cells and other stem cell lines, such as iPSCs. These data also raise the possibility that miRNAs bearing identical seed sequences could have specifi c functions during separable stages of early embryonic development.

Comprehensive microRNA expression profiling of the hematopoietic hierarchy

“…Recent work suggests that miRNAs are modulated during differentiation and act to lock in specific gene expression programs (13,14). The mean number of miRNAs detected in each population was 96 and varied between 49 and 148 (Fig.…”

Derivation of naïve human embryonic stem cells

“…For this reason, we decided to look at select miRs, miR-302b, miR-372, miR-518b, miR-520b, and miR520c. These miRs are expressed in the primed state of human pluripotency (9,10). miR-302b is thought to remain relatively stable throughout human pluripotency and was used as a positive control for the pluripotent state.…”

“…miR-302b is thought to remain relatively stable throughout human pluripotency and was used as a positive control for the pluripotent state. miR-372 may increase in hESC developmentally earlier than primed (10,11). As part of a primate-specific chromosome 19 miR cluster (CM19C), miR-518b, miR-520b, and mir-520c are known to be expressed in the primed state and to decline upon differentiation (9).…”

Um Modelo para Estudos de Modulação da Pluripotência e Diferenciação Celular em Células-Tronco Pluripotentes

“…Com base na literatura, é sabido que determinados miRNAs apresentam-se mais expressos em células indiferenciadas e, conforme essas células começam a diferenciar-se, o nível de expressão destes decai. O oposto também ocorre com diferentes miRNAs, sendo que estes não se apresentam expressos ou apresentam baixos níveis de expressão nas células indiferenciadas e sofrem um aumento de expressão conforme as células se diferenciam (Stadler et al, 2010;Xu et al, 2009).…”

“…Recentemente foram identificados grupos de miRNAs que são expressos em altos níveis nas CTE e cujos níveis reduziam durante a diferenciação e, alternativamente, grupos de miRNAs cujos níveis de expressão (ausentes ou baixos nas células pluripotentes) aumentavam durante a diferenciação (Stadler et al, 2010). Enquanto os miRNAs com expressão aumentada durante a diferenciação estariam envolvidos com a inibição do programa transcricional relacionado à pluripotência e auto-renovação das CTE, os miRNAs com expressão diminuída durante a diferenciação estariam envolvidos com a liberação do programa transcricional das células diferenciadas.…”