Xenopus: leaping forward in kidney organogenesis

Abstract

While kidney donations stagnate, the number of people in need of kidney transplants continues to grow. Although transplanting culture-grown organs is years away, pursuing the engineering of the kidney de novo is a valid means of closing the gap between the supply and demand of kidneys for transplantation. The structural organization of a mouse kidney is similar to that of humans. Therefore, mice have traditionally served as the primary model system for the study of kidney development. The mouse is an ideal model organism for understanding the complexity of the human kidney. Nonetheless, the elaborate structure of the mammalian kidney makes the discovery of new therapies based on de novo engineered kidneys more challenging. In contrast to mammals, amphibians have a kidney that is anatomically less complex and develops faster. Given that analogous genetic networks regulate the development of mammalian and amphibian nephric organs, using embryonic kidneys of Xenopus laevis (African clawed frog) to analyze inductive cell signaling events and morphogenesis has many advantages. Pioneering work that led to the ability to generate kidney organoids from embryonic cells was carried out in Xenopus. In this review, we discuss how Xenopus can be utilized to compliment the work performed in mammalian systems to understand kidney development.

Characterization of Xenopus laevis guanine deaminase reveals new insights for its expression and function in the embryonic kidney

“…Thus, a Gda effect on kidney functioning or maturation to mesonephroi might be expected. Moreover, knockdown of Xenopus GDAs resulted in edema formation, which has been shown to be indicative of kidney malfunction (Wessely and Tran, 2011; Krneta-Stankic et al, 2017). Nevertheless, at the Xenopus developmental time point that we performed our studies, the pronephroi has still not matured to mesonephroi, thus, it remains to be determined if Gda has an effect on kidney maturation to mesonephroi, or if the effect is restricted to kidney function.…”

“…Still, we wondered whether Gda might be important for kidney function. It has been demonstrated that an altered osmoregulatory function of the kidney leads to edema formation due to water retention (Wessely and Tran, 2011;Krneta-Stankic et al, 2017) and evaluation of edema has been widely used to assess kidney function (Getwan and Lienkamp, 2017;Krneta-Stankic et al, 2017). Thus, we used an antisense oligonucleotide to knock down (KD) gda by 50% (Fig.…”

Wnt signaling in kidney: the initiator or terminator?

“…In human and murine organisms, the pronephros and mesonephros are transient organs and degenerate at the embryonic stage [ 2 ]. Unlike in lower vertebrates, such as zebrafish and Xenopus, where the pronephros is functional at the embryonic and larval stages [ 24 , 25 ], the metanephros begins at E 32 in human and E 10.5 in mice [ 26 ]. Notably, the metanephros is permanent and will develop into a functional adult kidney in mammals.…”

Transgenic Xenopus laevis Line for In Vivo Labeling of Nephrons within the Kidney

“…Although the external development of X. laevis embryos allows for live imaging of many tissues, [ 24 ] live imaging of the kidney is difficult because there are currently no live markers. To facilitate the study of the dynamic cellular movements that occur during nephrogenesis, we generated a X. laevis transgenic line that labels the kidney cells.…”