RESUMO
Wnt signaling has been shown to play multiple roles in regenerative processes, one of the most widely studied of which is the regeneration of the intestinal luminal epithelia. Most studies in this area have focused on self-renewal of the luminal stem cells; however, Wnt signaling may also have more dynamic functions, such as facilitating intestinal organogenesis. To explore this possibility, we employed the sea cucumber Holothuria glaberrima that can regenerate a full intestine over the course of 21 days after evisceration. We collected RNA-seq data from various intestinal tissues and regeneration stages and used these data to define the Wnt genes present in H. glaberrima and the differential gene expression (DGE) patterns during the regenerative process. Twelve Wnt genes were found, and their presence was confirmed in the draft genome of H. glaberrima. The expressions of additional Wnt-associated genes, such as Frizzled and Disheveled, as well as genes from the Wnt/ß-catenin and Wnt/Planar Cell Polarity (PCP) pathways, were also analyzed. DGE showed unique distributions of Wnt in early- and late-stage intestinal regenerates, consistent with the Wnt/ß-catenin pathway being upregulated during early-stages and the Wnt/PCP pathway being upregulated during late-stages. Our results demonstrate the diversity of Wnt signaling during intestinal regeneration, highlighting possible roles in adult organogenesis.
Assuntos
Via de Sinalização Wnt , beta Catenina , Animais , beta Catenina/metabolismo , Intestinos , Mucosa Intestinal/metabolismo , OrganogêneseRESUMO
Regeneration of lost or injured organs is an intriguing process in which numerous cellular events take place to form the new structure. Studies of this process during reconstitution of the intestine have been performed in echinoderms, particularly in holothurians. Many cellular events triggered during regeneration have been described using the sea cucumber Holothuria glaberrima as a research model. More recent experiments have targeted the molecular mechanisms behind the process, a task that has been facilitated by the new sequencing technologies now available. In this review, we present studies involving cellular processes and the genes that have been identified to be associated with the early events of gut regeneration. We also present ongoing efforts to perform functional studies necessary to establish the role(s) of the identified genes. A synopsis of the studies is given with the course of the regenerative process established so far.