Interdigital tissue remodelling in the embryonic limb involves dynamic regulation of the miRNA profiles

Abstract

Next-generation sequencing in combination with quantitative polymerase chain reaction analysis revealed a dynamic miRNA signature in the interdigital mesoderm of the chick embryonic hinlimb in the course of interdigit remodelling. During this period, 612 previously known chicken miRNAs (gga-miRNAs) and 401 non-identified sequences were expressed in the interdigital mesoderm. Thirty-six microRNAs, represented by more than 750 reads per million, displayed differential expression between stages HH29 (6 id) and HH32 (7.5 id), which correspond to the onset and the peak of interdigital cell death. Twenty miRNAs were upregulated by at least 1.5-fold, and sixteen were downregulated by at least 0.5-fold. Upregulated miRNAs included miRNAs with recognized proapoptotic functions in other systems (miR-181 family, miR-451 and miR-148a), miRNAs associated with inflammation and cell senescence (miR-21 and miR-146) and miRNAs able to induce changes in the extracellular matrix (miR-30c). In contrast, miRNAs with known antiapoptotic effects in other systems, such as miR-222 and miR-205, became downregulated. In addition, miR-92, an important positive regulator of cell proliferation, was also downregulated. Together, these findings indicate a role for miRNAs in the control of tissue regression and cell death in a characteristic morphogenetic embryonic process based on massive apoptosis.

The Pervasive Role of the miR-181 Family in Development, Neurodegeneration, and Cancer

“…Role in interdigital tissue remodeling in the embryonic limb [30] Role in chondrocyte development [31][32][33]…”

“…miRNAs have been found to play relevant roles in several fundamental developmental processes among which gametogenesis, preimplantation and early embryonic development, neurogenesis and somitogenesis [8,9,29,30,106,107]. As a consequence, their expression during development needs to be tightly regulated in time and space.…”

“…Later in development, the tight regulation of miR-181 family members is of fundamental importance during interdigital tissue remodeling in the embryonic limb [30]. The development of the limb bud is accompanied by precise patterns of massive mesodermal programmed cell death required to eliminate undifferentiated cells which are needed only for a limited period of limb development.…”

“…These data were confirmed in embryonic duck limb during tissue remodeling. Quantitative polymerase chain reaction experiments showed increased expression levels of miR-181a at stages of maximum apoptosis and a drop at post-apoptosis stages compared with their expression levels before the onset of tissue regression [30]. At the same time, during embryonic limb formation, the development of cartilage begins with the condensation of mesenchymal stem cells (MSC) followed by differentiation toward the chondrocyte lineage [109].…”

MicroRNA profiling associated with muscle growth in modern broilers compared to an unselected chicken breed

“…The other miRNA, miR-133c-3p, that was abundantly expressed in chicken breast muscle [ 19 ], enhances skeletal muscle proliferation and differentiation by repressing SRF [ 11 ]. Similarly, miR-21 and miR-146c have been recently identified as miRNAs upregulated in chicken interdigital regression and associated with inflammation, cell senescence, and programed cell death [ 20 ]. Additionally, a previous study reported upregulated expression of miR-21 in breast muscle of low body weight chickens [ 9 ].…”