Abstract

A growing and important category of modern medicine is the field of regenerative medicine because through it exists the potential for organ replacement and improved tissue repair procedures. The challenges to regenerative medicine are many because of the complexity of the regenerative process. One approach to deciphering the mechanisms underlying regeneration is analysis of more simplified tissue systems that mimic that seen among all metazoans. To that end many laboratories across the world have focused on organisms such as Hydra (phylum Cnidaria and class Hydrozoa) because its body wall is reduced to an epithelial bilayer with an intervening extracellular matrix (ECM). That fact coupled with its high regenerative capacity (complete body form regeneration from pellets of dissociated epithelial cells isolated from the adult polyp) makes Hydra a powerful tool to investigate the underlying mechanisms of regeneration. Over the years it has become apparent that Hydra and higher vertebrates such as human share a common "developmental tool kit" that is used in their regenerative processes. This review will discuss the 1) cell-cell and cell-ECM processes as well as advances in 2) genomic and transcriptome studies that highlight key aspects of hydra regeneration that can be transferred to the field of regenerative medicine. In this regard, it can be concluded that understanding of basic regenerative mechanisms of Hydra can be applied and used to advance the field of regenerative medicine.

Keywords

regenerative medicine, regeneration, Hydra, receptor tyrosine kinase, transforming growth factor, ectoderm and endoderm, primitive groups, epithelial tissues, non-enzymatically, molecular structural components, gradient systems, disc activator, gradient equilibrium, cellular morphology, single-cell RNA