MINPP1 prevents intracellular accumulation of the chelator inositol hexakisphosphate and is mutated in Pontocerebellar Hypoplasia.

Abstract

Inositol polyphosphates are vital metabolic and secondary messengers, involved in diverse cellular functions. Therefore, tight regulation of inositol polyphosphate metabolism is essential for proper cell physiology. Here, we describe an early-onset neurodegenerative syndrome caused by loss-of-function mutations in the multiple inositol-polyphosphate phosphatase 1 gene (MINPP1). Patients are found to have a distinct type of Pontocerebellar Hypoplasia with typical basal ganglia involvement on neuroimaging. We find that patient-derived and genome edited MINPP1-/- induced stem cells exhibit an inefficient neuronal differentiation combined with an increased cell death. MINPP1 deficiency results in an intracellular imbalance of the inositol polyphosphate metabolism. This metabolic defect is characterized by an accumulation of highly phosphorylated inositols, mostly inositol hexakisphosphate (IP6), detected in HEK293 cells, fibroblasts, iPSCs and differentiating neurons lacking MINPP1. In mutant cells, higher IP6 level is expected to be associated with an increased chelation of intracellular cations, such as iron or calcium, resulting in decreased levels of available ions. These data suggest the involvement of IP6-mediated chelation on Pontocerebellar Hypoplasia disease pathology and thereby highlight the critical role of MINPP1 in the regulation of human brain development and homeostasis.

• Authors: Ekin Ucuncu, Karthyayani Rajamani, Miranda S C Wilson, Daniel Medina-Cano, Nami Altin, Pierre David, Giulia Barcia, Nathalie Lefort, Céline Banal, Marie-Thérèse Vasilache-Dangles, Gaële Pitelet, Elsa Lorino, Nathalie Rabasse, Eric Bieth, Maha S Zaki, Meral Topcu, Fatma Mujgan Sonmez, Damir Musaev, Valentina Stanley, Christine Bole-Feysot, Patrick Nitschké, Arnold Munnich, Nadia Bahi-Buisson, Catherine Fossoud, Fabienne Giuliano, Laurence Colleaux, Lydie Burglen, Joseph G Gleeson, Nathalie Boddaert, Adolfo Saiardi, Vincent Cantagrel
• Journal: Nature communications (Nat Commun) Vol. 11 Issue 1 Pg. 6087 (11 30 2020) ISSN: 2041-1723 [Electronic] England
• PMID: 33257696 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Chelating Agents
• Phytic Acid
• Phosphoric Monoester Hydrolases
• multiple inositol-polyphosphate phosphatase

Topics

• Animals
• Cell Death
• Cell Differentiation
• Cerebellar Diseases (diagnostic imaging, metabolism, pathology)
• Chelating Agents (metabolism)
• Child
• Child, Preschool
• Cytoplasm (metabolism)
• Female
• Gene Knockout Techniques
• HEK293 Cells
• Homeostasis
• Humans
• Infant
• Male
• Mice, Inbred C57BL
• Mice, Knockout
• Mutation
• Neurodevelopmental Disorders (metabolism)
• Phosphoric Monoester Hydrolases (genetics, metabolism, pharmacology)
• Phosphorylation
• Phytic Acid (metabolism)
• Stem Cells (drug effects)
• Transcriptome