AAV-delivered diacylglycerol kinase DGKk achieves long-term rescue of fragile X syndrome mouse model

EMBO Mol Med. 2022 May 9;14(5):e14649. doi: 10.15252/emmm.202114649. Epub 2022 Apr 4.

Abstract

Fragile X syndrome (FXS) is the most frequent form of familial intellectual disability. FXS results from the lack of the RNA-binding protein FMRP and is associated with the deregulation of signaling pathways downstream of mGluRI receptors and upstream of mRNA translation. We previously found that diacylglycerol kinase kappa (DGKk), a main mRNA target of FMRP in cortical neurons and a master regulator of lipid signaling, is downregulated in the absence of FMRP in the brain of Fmr1-KO mouse model. Here we show that adeno-associated viral vector delivery of a modified and FMRP-independent form of DGKk corrects abnormal cerebral diacylglycerol/phosphatidic acid homeostasis and FXS-relevant behavioral phenotypes in the Fmr1-KO mouse. Our data suggest that DGKk is an important factor in FXS pathogenesis and provide preclinical proof of concept that its replacement could be a viable therapeutic strategy in FXS.

Keywords: AAV; FMRP; Fmr1-KO; Fragile X syndrome; diacylglycerol kinase.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Diacylglycerol Kinase / genetics
  • Diacylglycerol Kinase / metabolism
  • Disease Models, Animal
  • Fragile X Mental Retardation Protein / genetics
  • Fragile X Mental Retardation Protein / metabolism
  • Fragile X Syndrome* / genetics
  • Fragile X Syndrome* / metabolism
  • Fragile X Syndrome* / therapy
  • Mice
  • Mice, Knockout

Substances

  • Fmr1 protein, mouse
  • Fragile X Mental Retardation Protein
  • Diacylglycerol Kinase