Regeneration of the digestive system in the crinoid Himerometra robustipinna occurs by transdifferentiation of neurosecretory-like cells

Abstract

The structure and regeneration of the digestive system in the crinoid Himerometra robustipinna (Carpenter, 1881) were studied. The gut comprises a spiral tube forming radial lateral processes, which gives it a five-lobed shape. The digestive tube consists of three segments: esophagus, intestine, and rectum. The epithelia of these segments have different cell compositions. Regeneration of the gut after autotomy of the visceral mass progresses very rapidly. Within 6 h after autotomy, an aggregation consisting of amoebocytes, coelomic epithelial cells and juxtaligamental cells (neurosecretory neurons) forms on the inner surface of the skeletal calyx. At 12 h post-autotomy, transdifferentiation of the juxtaligamental cells starts. At 24 h post-autotomy these cells undergo a mesenchymal-epithelial-like transition, resulting in the formation of the luminal epithelium of the gut. Specialization of the intestinal epithelial cells begins on day 2 post-autotomy. At this stage animals acquire the mouth and anal opening. On day 4 post-autotomy the height of both the enterocytes and the visceral mass gradually increases. Proliferation does not play any noticeable role in gut regeneration. The immersion of animals in a 10−7 M solution of colchicine neither stopped formation of the lost structures nor caused accumulation of mitoses in tissues. Weakly EdU-labeled nuclei were observed in the gut only on day 2 post-autotomy and were not detected at later regeneration stages. Single mitotically dividing cells were recorded during the same period. It is concluded that juxtaligamental cells play a major role in gut regeneration in H. robustipinna. The main mechanisms of morphogenesis are cell migration and transdifferentiation.

Injury affects coelomic fluid proteome of the common starfishAsterias rubens

“…Our assumptions about the activation of regenerative processes is supported by an overlap of injury-responsive proteins with those involved in regeneration in sea cucumbers, namely β-microseminoprotein, serum amyloid A, and ependymin-like and avidin-like proteins. Observed associations of cancer-related terms with such proteins as WAPL, LYSTARs, GRAN, BMSP, CATB, CLTR and ENDL is not surprising, because carcinogenesis involves both cell migration and transdifferentiation, which are thought to be important mechanisms of regeneration in echinoderms (Kalacheva et al, 2017). Therefore, our dataset may represent an important tool for discovery of novel proteins involved in regeneration in echinoderms, suggesting important targets for future studies.…”

Sewing up the wounds : The epithelial morphogenesis as a central mechanism of calcaronean sponge regeneration

“…variabilis . This type of transdifferentiation is well known in some animals (Becker & Jarriault, ), for example, during transdifferentiation of fibroblasts into neuronal cells (Fishman et al, ), or juxtaligamental cells into enterocytes in Crinoidea (Kalacheva et al, ).…”

“…In this case, this transdifferentiation occurs through the direct conversion of exopinacocytes into porocytes without the requirement for cell division. This type of transdifferentiation is well known in animals (Becker & Jarriault, 2016) for example, during transdifferentiation of fibroblasts into neuronal cells (Fishman et al, 2015), or juxtaligamental cells into enterocytes in Crinoidea (Kalacheva, Eliseikina, Frolova, & Dolmatov, 2017).…”

Induced in vivo transdifferentiation of vertebrate muscle into early endoderm-like cells

“…However, in the invertebrate roundworm Caenorhabditis elegans, it was demonstrated that two speci c non-endoderm cell lineages, can be arti cially converted into intestinal cells, which are normally of endoderm origin 3,4 . It remains unclear whether in vivo intergerm layer lineage conversion is unique to these cell types or to this and other invertebrates 5 . The ability to directly reprogram a differentiated vertebrate cell identity in vivo, without spatial or lineage limitations, would indicate that the developmental origin of a cell and its natural microenvironment does not absolutely limit its potential identity, challenging the dogma of in vivo developmental lineage restriction and opening potential new avenues for regenerative medicine.…”