Dataset Information

Deciphering the Neurological Puzzle in ALG13-CDG Through Cutting-Edge Brain Organoid Modeling

ABSTRACT: Asparagine-linked glycosylation 13 (ALG13) is an X-linked congenital disorder of glycosylation (CDG) with limited treatment options and mechanistic understanding. Investigating ALG13-CDG has been challenging due to elusive glycosylation defects in patient samples, particularly in blood and fibroblasts. However, profound neurological symptoms strongly suggest a primary impact on the brain. To explore this, we developed an in vitro ALG13-CDG 3D human cortical brain organoid (hCOs) model using induced pluripotent stem cells (iPSCs) derived from fibroblasts. Both iPSCs and hCOs revealed X-inactivation skewing. Our multi-omics analysis unveiled reductions in glycosylation of key proteins crucial for brain function, along with alterations in proteins and transcripts linked to neuronal migration, nucleotide synthesis, epilepsy risk, and lipid metabolism. Metabolomic analyses in ALG13-CDG hCOs showed elevated GlcNAc levels and decreased nucleotide synthesis metabolites. Our study sheds light on the unrecognized protein glycosylation defect in ALG13-CDG, offering insights into its brain-related disturbances and potential for guiding clinical management, especially in addressing seizures, a critical unmet medical need.

INSTRUMENT(S):

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Brain

DISEASE(S): Congenital Disorder Of Glycosylation

SUBMITTER: Akhilesh Pandey

LAB HEAD: Akhilesh Pandey

PROVIDER: PXD051647 | Pride | 2026-02-02

REPOSITORIES: Pride

ACCESS DATA

Dataset's files

Source:

			Action	DRS
	061423_RB_ALG13_Brain_TMT18_HCD_NGP_F1.raw	Raw
	061423_RB_ALG13_Brain_TMT18_HCD_NGP_F10.raw	Raw
	061423_RB_ALG13_Brain_TMT18_HCD_NGP_F11.raw	Raw
	061423_RB_ALG13_Brain_TMT18_HCD_NGP_F12.raw	Raw
	061423_RB_ALG13_Brain_TMT18_HCD_NGP_F2.raw	Raw

Items per page:

1 - 5 of 27

Publications

Network Hypoactivity in ALG13-CDG: Disrupted Developmental Pathways and E/I Imbalance as Early Drivers of Neurological Features in CDG.

Shah Rameen R Budhhraja Rohit R Radenkovic Silvia S Preston Graeme G King Alexia Tyler AT Sabry Sahar S Bleukx Charlotte C Shammas Ibrahim I Young Lyndsay L Chandran Jisha J Byeon Seul Kee SK Hrstka Ronald R Smith Doughlas Y DY Staff Nathan P NP Drake Richard R Sloan Steven A SA Pandey Akhilesh A Morava Eva E Kozicz Tamas T

Cells 20260114 2

<h4>Background</h4>ALG13-CDG is an X-linked N-linked glycosylation disorder caused by pathogenic variants in the glycosyltransferase ALG13, leading to severe neurological manifestations. Despite the clear CNS involvement, the impact of ALG13 dysfunction on human brain glycosylation and neurodevelopment remains unknown. We hypothesize that ALG13-CDG causes brain-specific hypoglycosylation that disrupts neurodevelopmental pathways and contributes directly to cortical network dysfunction.<h4>Method ...[more]

PMID: 41597222

Similar Datasets

Project description:Phosphomannomutase 2 (PMM2) converts mannose-6-phospahate to mannose-1-phosphate; the substrate for GDP-mannose, a building block of the glycosylation biosynthetic pathway. Pathogenic variants in the PMM2 gene have been shown to be associated with protein hypoglycosylation causing PMM2-congenital disorder of glycosylation (PMM2-CDG). While mannose supplementation improves glycosylation in vitro, but not in vivo, we hypothesized that liposomal delivery of mannose-1-phosphate could increase the stability and delivery of the activated sugar to enter the targeted compartments of cells. Thus, we studied the effect of liposome-encapsulated mannose-1-P (GLM101) on global protein glycosylation and on the cellular proteome in skin fibroblasts from individuals with PMM2-CDG, as well as in individuals with two N-glycosylation defects early in the pathway, namely ALG2-CDG and ALG11-CDG. We leveraged multiplexed proteomics and N-glycoproteomics in fibroblasts derived from different individuals with various pathogenic variants in PMM2, ALG2 and ALG11 genes. Proteomics data revealed a moderate but significant change in the abundance of some of the proteins in all CDG fibroblasts upon GLM101 treatment. On the other hand, N-glycoproteomics revealed the GLM101 treatment enhanced the expression levels of several high-mannose and complex/hybrid glycopeptides from numerous cellular proteins in individuals with defects in PMM2 and ALG2 genes. Both PMM2-CDG and ALG2-CDG exhibited several-fold increase in glycopeptides bearing Man6 and higher glycans and a decrease in Man5 and smaller glycan moieties, suggesting that GLM101 helps in the formation of mature glycoforms. These changes in protein glycosylation were observed in all individuals irrespective of their genetic variants. ALG11-CDG fibroblasts also showed increase in high mannose glycopeptides upon treatment; however, the improvement was not as dramatic as the other two CDG. Overall, our findings suggest that treatment with GLM101 overcomes the genetic block in the glycosylation pathway and can be used as a potential therapy for CDG with enzymatic defects in early steps in protein N-glycosylation.

Project description:SRD5A3-CDG is a congenital disorder of glycosylation (CDG) resulting from pathogenic variants in SRD5A3 and follows an autosomal recessive inheritance pattern. The enzyme encoded by SRD5A3, polyprenal reductase, plays a crucial role in synthesizing lipid precursors essential for N-linked glycosylation. Despite insights from functional studies into its enzymatic function, there remains a gap in understanding global changes in patient cells. We sought to identify glycoproteomic and proteomic signatures specific to SRD5A3-CDG, potentially aiding in biomarker discovery and advancing our understanding of disease mechanisms. Using tandem mass tag (TMT)-based relative quantitation, we analyzed fibroblasts derived from five patients along with control fibroblasts. Glycoproteomics analysis by liquid chromatographyâ€“tandem mass spectrometry (LC-MS/MS) identified 3,047 glycopeptides with 544 unique glycosylation sites from 276 glycoproteins. Of these, 418 glycopeptides showed statistically significant changes with 379 glycopeptides decreased (p<0.05) in SRD5A3-CDG patient-derived samples. These included high mannose, complex and hybrid glycan-bearing glycopeptides. High mannose glycopeptides from protocadherin Fat 4 and integrin alpha-11 and complex glycopeptides from CD55 were among the most significantly decreased glycopeptides. Proteomics analysis led to the identification of 5,933 proteins, of which 873 proteins showed statistically significant changes. Decreased proteins included cell surface glycoproteins, various mitochondrial protein populations and proteins involved in the N-glycosylation pathway. Lysosomal proteins such as N-acetylglucosamine-6-sulfatase and procathepsin-L also showed reduced levels of phosphorylated mannose-containing glycopeptides. Our findings point to disruptions in glycosylation pathways as well as energy metabolism and lysosomal functions in SRD5A3-CDG, providing clues to improved understanding and management of patients with this disorder.