On the origin of amniotic stem cells: of mice and men

Abstract

A common characteristic of mammals is the development of extraembryonic supporting tissues and organs that are required for embryonic implantation, survival and development in utero. The amnion is the innermost extraembryonic membrane that eventually surrounds the fetus of amniotes, and contains the amniotic fluid. Next to its function in in utero development, the amnion has been shown to have an important potential for clinical applications. It is mainly used as a dressing to stimulate healing in skin and ocular wounds. Moreover, cells derived from the amniotic membrane and amniotic fluid have been reported to possess stem cell features, like pluripotent differentiation ability. Little is known about the early development of this membrane in humans. The mouse is a powerful genetic model organism that can be used to address the dynamics and the developmental origin of amnion and amnion-derived stem cells. Here, we discuss some fundamental differences in amnion development in the disc-shaped primate embryo and in the cup-shaped mouse embryo. We emphasize the consequences that this may have on the derivation of amniotic "stem" cells. After revision of the different isolation procedures of amniotic (fluid) derived "stem" cells from rodents, we reveal striking differences in the sources used to derive these cells across studies. The profound differences in the development of the extraembryonic membranes and cavities between primates and rodents may result in comparing cell types of different developmental origins, eventually leading to missinterpretations.

Advances in flow cytometry in basic and applied equine andrology

“…In the rhesus monkey (Enders et al, 1986) and human (Shahbazi et al, 2016), the amnion forms by cavitation as a space appears amidst a group of polarized cells in the epiblast. In the mouse, a proamnion appears in the centre of the epiblast, but the true amnion is formed from the amniochorionic fold (Dobreva et al, 2010). However, all members of Ferungulata retain the plesiomorphic state, which is amnion formation by folding (Mess and Carter, 2006).…”

Amniotic fluid stem cell-based models to study the effects of gene mutations and toxicants on male germ cell formation

“…Furthermore, monoclonal human AFS cell lines have been reported to maintain genome stability during expansion and do not induce tumour formation in severe combined immunodeficient mice. 41,44,46,47,49,61,62 To analyse the genetic mechanisms of sperm cell development, it is of the highest relevance to use stem cell-based models, which allow the investigation of the consequences of a specific genetic aberration. 63,64 One approach would be to use stem cells with natural occurring genetic aberrations, which are of relevance for human pathological phenotypes associated with infertility.…”

Portal hypertension-related inflammatory phenotypes: From a vitelline and amniotic point of view

“…Particularly, in the earliest stage of the embryonic development the vitelline system, as well as the amnion, stands out [7,8] (Figure 1). The portal system, derived from the extraembryonic vitelline venous system continues to perform a vital trophic role for post-natal organism survival and development, although based on its new metabolic needs [2,7].…”

“…Hence, it is important to keep in mind that a common characteristic of mammals is the development of extraembryonic supporting tissues and organs that are required for embryonic implantation, survival and development "in utero" [8]. Particularly, in the earliest stage of the embryonic development the vitelline system, as well as the amnion, stands out [7,8] (Figure 1).…”