MedPath

Impact of Mutations in Aminoacyl tRNA Synthetases on Protein Translation and Cellular Stress

Not Applicable
Not yet recruiting
Conditions
Interstitial Lung and Liver Disease
Infantile Liver Failure Syndrome 1
Neurologic, Endocrine and Pancreatic Disease, Multisystem, Infantile-Onset 2
Rajab Interstitial Lung Disease with Brain Calcifications 2
Interventions
Other: Skin biopsy
Registration Number
NCT05514470
Lead Sponsor
Assistance Publique - Hôpitaux de Paris
Brief Summary

Mutations in the genes encoding cytosolic aminoacyl-tRNA synthetases are responsible for early-onset multisystemic diseases including to varying degrees interstitial lung disease, liver damage, neurological and digestive disorders, and systemic inflammation. These are rare and severe diseases whose pathophysiology is poorly understood.

The investigative team hypothesizes that mutations within these genes are responsible for a decrease in protein translation and lead to a cellular stress response similar to that induced by amino acid deprivation. The investigative team also hypothesizes that these alterations could be corrected by high-dose supplementation in the culture medium of the corresponding amino acid.

The main objective of the study is to precisely determine the consequences of cytosolic aminoacyl-tRNA synthetase mutations at the cell level on protein translation.

Detailed Description

Mutations in the genes encoding cytosolic aminoacyl-tRNA synthetases are responsible for early-onset multisystemic diseases including to varying degrees interstitial lung disease, liver damage, neurological and digestive disorders, and systemic inflammation. These are rare and severe diseases whose pathophysiology is poorly understood.

The investigative team hypothesizes that mutations within these genes are responsible for a decrease in protein translation and lead to a cellular stress response similar to that induced by amino acid deprivation. The investigative team also hypothesizes that these alterations could be corrected by high-dose supplementation in the culture medium of the corresponding amino acid.

The main objective of the study is to precisely determine the consequences of cytosolic aminoacyl-tRNA synthetase mutations at the cell level on protein translation.

The parameters below will be studied in vitro in cell culture from skin biopsies of patients and control cells:

* Determination of total protein content

* The incorporation of d-methionine, leucine, tyrosine or phenylalanine into proteins

* The study of polysomes profiling

* The study of the assembly of the ribosomal 43S pre-initiation complex

* The phosphorylation of eIF2α and 4EBP and the expression of ATF4

* Ribosome profiling

* Transfer RNA (tRNA) sequencing

* The production of reactive oxygen species (ROS)

The results of these studies will be compared:

* Between patient cells and control cells

* Between genetically corrected patient cells, by stable transfection of the wild-type cDNA of the concerned genes and uncorrected cells

* Between patient cells cultured in medium enriched with the corresponding amino acid.

Recruitment & Eligibility

Status
NOT_YET_RECRUITING
Sex
All
Target Recruitment
22
Inclusion Criteria
  • Patients carrying mutations in genes encoding cytosolic aminoacyl-tRNA synthetases responsible for a multi-systemic phenotype
  • Information and consent of the patient if an adult and of the holders of parental authority if a minor patient and of the minor patient
Exclusion Criteria
  • Non-consent of one of the holders of parental authority or of the minor patient or of adult patient

Contrôl patients :

  • Fibroblasts from control patients without mutation in genes encoding cytosolic aminoacyl-tRNA synthetases, from an existing biological collection. The control patients will be selected according to the age at which the skin biopsy was performed in order to have an age match between the patients and the controls.
  • Information and consent of the patient if an adult and of the holders of parental authority if a minor patient and of the minor patient

Study & Design

Study Type
INTERVENTIONAL
Study Design
SINGLE_GROUP
Arm && Interventions
GroupInterventionDescription
PatientsSkin biopsyPatients with mutations in genes encoding cytosolic aminoacyl-tRNA synthetases and cared at Necker Hospital.
Primary Outcome Measures
NameTimeMethod
Ribosome profilingDay 0

Ribosome profiling by high throughput sequencing.

Incorporation of d-methionine and d-phenylalanine into proteinsDay 0

Incorporation of methionine and phenylalanine by labelled amino-acid fluorescent assays using ready-to-use kits.

Study of polysomes profilingDay 0

Study of polysome profils by differential sedimentation on sucrose gradients.

Production of reactive oxygen species (ROS)Day 0

Production of reactive oxygen species (ROS) by fluorescent measurement after cells' incubation with 2',7'- dichlorodihydrofluorescein diacetate (H2DCFDA).

Study of the assembly of the ribosomal 43S pre-initiation complexDay 0

Study of the assembly of the ribosomal 43S pre-initiation complex by co-immunoprecipitation experiments.

Phosphorylation of eIF2α and 4EBP and the expression of ATF4Day 0

Phosphorylation of eIF2α and 4EBP and the expression of ATF4 by western blot.

Transfer RNA (tRNA) sequencingDay 0

Transfer RNA (tRNA) sequencing by high throughput sequencing.

Determination of total protein contentDay 0

Determination of total protein content by Bicinchoninic acid assay.

Secondary Outcome Measures
NameTimeMethod

Trial Locations

Locations (1)

Hôpital Necker-Enfants Malades

🇫🇷

Paris, France

© Copyright 2025. All Rights Reserved by MedPath