Plasma membrane cholesterol depletion disrupts prechordal plate and affects early forebrain patterning

Abstract

Cholesterol-rich membrane microdomains (CRMMs) are specialized structures that have recently gained much attention in cell biology because of their involvement in cell signaling and trafficking. However, few investigations, particularly those addressing embryonic development, have succeeded in manipulating and observing CRMMs in living cells. In this study, we performed a detailed characterization of the CRMMs lipid composition during early frog development. Our data showed that disruption of CRMMs through methyl-β-cyclodextrin (MβCD) cholesterol depletion at the blastula stage did not affect Spemann's organizer gene expression and inductive properties, but impaired correct head development in frog and chick embryos by affecting the prechordal plate gene expression and cellular morphology. The MβCD anterior defect phenotype was recapitulated in head anlagen (HA) explant cultures. Culture of animal cap expressing Dkk1 combined with MβCD-HA generated a head containing eyes and cement gland. Together, these data show that during Xenopus blastula and gastrula stages, CRMMs have a very dynamic lipid composition and provide evidence that the secreted Wnt antagonist Dkk1 can partially rescue anterior structures in cholesterol-depleted head anlagen.

Pharmacologic Treatment Assigned for Niemann Pick Type C1 Disease Partly Changes Behavioral Traits in Wild-Type Mice

“…Possibly a reduced membrane biosynthesis or reduced lipid storage due to inhibition of the glucosylceramide biosynthetic pathway by miglustat is responsible for the reduced brain weights of combination- and miglustat-treated mice [42]. For methyl-β-cyclodextrin (MβCD) it has recently been shown that plasma membrane cholesterol depletion affects early forebrain patterning in Xenopus [43]. MβCD-injected embryos displayed reduced eyes or lack eyes entirely, most likely because of loss of neural tissue from where these structures derive.…”

Sterol carrier protein 2 regulates proximal tubule size in the Xenopus pronephric kidney by modulating lipid rafts

“…It has recently been shown that lipid rafts are present during early Xenopus development (Reis et al, 2012). However, little is known about their occurrence and function during kidney development.…”

“…Mevinolin) disrupts signaling events mediated by lipid rafts (Klein et al, 1995; Taraboulos et al, 1995). They cause dramatic defects during embryonic development affecting signaling pathways like sonic hedgehog and Wnt (Cooper et al, 2003; Tadjuidje and Hollemann, 2006; Anderson et al, 2011; Reis et al, 2012). Similarly, mice lacking protein components of lipid rafts such as Caveolin-1 display a wide range of embryological defects (Drab et al, 2001; Razani et al, 2001; Zhao et al, 2002).…”

Establishing embryonic territories in the context of Wnt signaling

“…Which was illustrated by Sox2 diminished expression only at the anterior neural plate region (Fig. 3c), as well as the mispatterned expression of Otx2 and Six3 (Reis et al, 2012). Then, we went further on and specified, through transplantation experiments, the developmental window in which the head mesoderm/prechordal plate gets compromised.…”