Glycosylphosphatidylinositol biosynthesis and remodeling are required for neural tube closure, heart development, and cranial neural crest cell survival

Abstract

Glycosylphosphatidylinositol (GPI) anchors attach nearly 150 proteins to the cell membrane. Patients with pathogenic variants in GPI biosynthesis genes develop diverse phenotypes including seizures, dysmorphic facial features and cleft palate through an unknown mechanism. We identified a novel mouse mutant (cleft lip/palate, edema and exencephaly; Clpex) with a hypo-morphic mutation in Post-Glycophosphatidylinositol Attachment to Proteins-2 (Pgap2), a component of the GPI biosynthesis pathway. The Clpex mutation decreases surface GPI expression. Surprisingly, Pgap2 showed tissue-specific expression with enrichment in the brain and face. We found the Clpex phenotype is due to apoptosis of neural crest cells (NCCs) and the cranial neuroepithelium. We showed folinic acid supplementation in utero can partially rescue the cleft lip phenotype. Finally, we generated a novel mouse model of NCC-specific total GPI deficiency. These mutants developed median cleft lip and palate demonstrating a previously undocumented cell autonomous role for GPI biosynthesis in NCC development.

CNS Glycosylphosphatidylinositol Deficiency Results in Delayed White Matter Development, Ataxia, and Premature Death in a Novel Mouse Model

“…We obtained the conditional Piga allele, ( B6.129-Piga <tm1> ) which has been used in several studies to delete Piga with Cre/lox technology [14, 16, 18]. Upon Cre recombination, the final exon of the conditional Piga is deleted and GPI biosynthesis is severely disrupted indicating the allele efficiently abolishes Piga function [14, 16, 18]. We crossed these mice to Nestin-Cre mice (B6.Cg-Tg(Nes-cre)1 Kln/J ).…”

“…Recently, we used this conditional allele to delete Piga in the developing mouse neural crest cells with Wnt1-Cre. This deletion resulted in cleft lip and cleft palate as well as hypoplasia of the craniofacial skeleton highlighting a critical role for GPI biosynthesis in neural crest cell survival [14]. Others have used this approach to reveal an important role for GPI biosynthesis in skin, limb, blood and craniofacial development [15–17].…”

Association Study of Genetic Variants in Autophagy Pathway and Risk of Non-syndromic Cleft Lip With or Without Cleft Palate

“…We further knockdown of HIF1A to evaluate its role in the function of HOEC and HEPM. Promoted cell apoptosis, inhibited cell proliferation, and increase in G0/G1 phase cells, accompanied by a decrease in the number of S phase cells were detected and all of events commonly occurred during the development of NSCL/P ( Tian et al, 2017 ; Lukacs et al, 2019 ). For instance, Lu et al reported that cell proliferation increased and apoptosis decreased in the E13d mutant rabbit model related to NSCL/P, which would lead to the persistence of seams in the facial processes ( Lu et al, 2019 ).…”

A novel hypomorphic allele ofSpag17causes primary ciliary dyskinesia phenotypes in mice

“…We identified the primary ciliary dyskinesia only (Pcdo) mutant in a mouse ENU mutagenesis forward genetic screen for recessive alleles leading to organogenesis phenotypes. ENU mutagenesis was performed as described previously (Stottmann, Moran et al 2011, Stottmann and Beier 2014, Menke, Cionni et al 2015, Lukacs, Roberts et al 2019) and phenotyping to recover mutant alleles was performed at early postnatal stages as part of an experiment to look for mutants with abnormal forebrain development. Pcdo mutants were initially identified by enlarged head and distended lateral ventricles upon gross dissection.…”