Biosynthèse et remodelage des Phospholipides: Une nouvelle catégorie des EIM
Printemps de la SFEIM Toulouse Juin 2013 Structure des Phospholipides
O
O H C OH H O C C O H HO C H Fatty acid (saturated) Fatty acid H C OH (MU, PU) Phospho- O glycerol HO P OH O-
NH COOH H3C 2
+ H3C N CH3 2HN CH CH2 OH OH O O O O- O O O- P O O- P O O- O O-
P P O O P
O O O
O O O O O O O
O O C C C O C C C C C C C C C C C O O C O O O O O O O O
Lyso-PA PA PC PE PS variabilité Structurale Remodelage permanent des structures
X O PLD O P O- PLC
O O O PLA1 C C C O O PLA2
PA
• Fatty acids release • Fatty acids exchange • Base exchange Rôle Physiologique des PL
• Biological membranes – Cell membranes – Myelin • Energy metabolism • Cell signaling ( Archidonique Ac, Endocannabinoïds, PGN, LTN..) – Inflammation – Apopotosis – Metabolic regulation (Acylation) • Intracellular trafficking and cell adhesion • Epidermal water barrier • Mitochondrial function • Visual cycle Présentation Clinique
CNS presentation
Leukodystrophy and/or iron deposits in basal ganglia (NBIA) (Neurodegeneration with Brain Iron Accumulation NBIA) : PLA2G6,
Spastic paraplegia (SPG 54:DDH2;SPG 28:DDH1;SPG 49: CYP2U1)
SPG with muscle wasting : Neuropathy target esterase deficiency (NTE: SPG 39).
Spastic quadriplegia with ichthyosis : ELOV4 deficiency and Sjogren-Larsson syndrome
Peripheral nerve presentation
PHARC syndrome: α-/β-hydrolase 12 deficiency
Muscular/cardiac presentations
Recurrent myoglobinuria : (Lipin1) deficiency
Barth syndrome : Cardiolipin deficiency ( Tafazzin mutations)
Sengers syndrome : mitochondrial acylglycerolkinase deficiency.
Congenital muscular dystrophy : choline-kinase deficiency Dihydroxyacetone Glycerol-3-phosphate Glycerol 3-phosphate Acyl CoA G3P-AT CoA-SH -
Lysophosphatidic Acid
Acyl CoA ABHD5 AG-AT CoA-SH
Phosphatidic Acid a/b Hydrolase domain containig 5 (ABHD5) Syndrome de Chanarin-Dorfman (AR) Chanarin et al, 1974 Lefèvre et al,2001 • Erythrodermic Ichthyosis (congenital) • Hepatomegaly with liver steatosis (70%) • Nystagmus, cataracts, decreased hearing • Mental, developmental retardation • Myopathy
Non lysosomal lipid storage disease Tissular accumulation of neutral lipids (vacuolated PBC). Dihydroxyacetone Glycerol-3-phosphate Glycerol 3-phosphate Acyl CoA G3P-AT CoA-SH -
Lysophosphatidic Acid
Acyl CoA ABHD5 AG-AT CoA-SH
Phosphatidic Acid CTP CDP-DAG PAP ADP ATP Synthase PPi
Diacylglycerol CDP Diacylglycerol Déficit en Lipin 1 Phosphatidate phosphatase (AR)
Lipin1 deficiency Zeharia et al. 2008 Onset in infancy and childhood (2-7 y). • Rhabdomyolysis, iduced by febrile illness, anaesthesia, fasting • Episodic myoglobinuria with CK elevation • Muscular Hypotonia First cause of rhabdomyolysis after bêta-oxydation defects Dual role : • Biosynthesis of Triacylglycerol and phospholipids • Regulation of the expression of genes encoding fatty acid oxidation and respiratory chain enzymes: PPAR-a and PGC-1a
Lpin2 deficiency : Majeed Syndrome Onset in infancy and childhood. • Multifocal osteomyelitis, • Dyserythropoietic anemia • Hepatosplenomagaly Dihydroxyacetone Glycerol-3-phosphate Glycerol 3-phosphate Acyl CoA G3P-AT CoA-SH -
Lysophosphatidic Acid
Acyl CoA ABHD5 AG-AT CoA-SH
Phosphatidic Acid CTP CDP-DAG PAP Synthase PPi
Diacylglycerol CDP Diacylglycerol
PC-Cytidylyl CDP-PEth CHK transferase CMP Phospho- choline choline CDP-PChol PE-N-methyl CMP ATP ADP transferase SAH SAM
PC PE PG
Chol PS Ser Ser Eth Déficit en CHKb Choline Kinase b (AR) Mitsuhashi et al. 2011
Early onset Muscular dystrophy (in infancy) Mental retardation Developmental delay (+/- epilepsy) Dilated cardiomyopathy Megaconial mitochondria
Decresed levels of PC and PC/PE ratio in muscle biopsy.
Dihydroxyacetone Glycerol-3-phosphate Glycerol 3-phosphate Acyl CoA G3P-AT CoA-SH -
Lysophosphatidic Acid
Acyl CoA ABHD5 AG-AT CoA-SH
Phosphatidic Acid CTP CDP-DAG PAP Synthase PPi
Triacylglycerol Diacylglycerol CDP Diacylglycerol DGAT
PC-Cytidylyl CDP-PEth CHK transferase CMP Phospho- choline choline CDP-PChol PE-N-methyl CMP ATP ADP transferase SAH SAM
PC PE PG C18:0/C18:1 Chol PS Ser Ser Eth Déficit en DGAT 1 Congenital diarrhea disorder
Haas et al. 2012
Reported in a nonconsanguineous Ashkenazi Jewish family • Early onset intractable diarrhea (few days after birth) • Delayed fat absorption • Fasting hypertriglyceridemia with normal cholesterol • Resolution of symptoms at 10 to 12 months of age
Dihydroxyacetone Glycerol-3-phosphate Glycerol 3-phosphate Acyl CoA G3P-AT CoA-SH -
Lysophosphatidic Acid
Acyl CoA ABHD5 AG-AT CoA-SH
Phosphatidic Acid CTP CDP-DAG PAP + Synthase PPi PNPLA2 Diacylglycerol CDP Diacylglycerol Triacylglycerol DGAT
PC-Cytidylyl CDP-PEth CHK transferase CMP Phospho- choline choline CDP-PChol PE-N-methyl CMP ATP ADP transferase SAH SAM
PC PE PG C18:0/C18:1 Chol PS Ser Ser Eth Déficit en PNPLA2 Neutral lipid storage with myopathy (AR)
Fischer et al. 2007
• Adipose triglyceride lipase of lipid droplets • Myopathy of proximal and distal muscles • Assymetric Muscle Atrophy •Hepatomegaly, liver steatosis (50%) • Absence of ichthyosis •Accumulation of Multisystem triglyceride storage : • Lipid droplets in muscle, leucocytes (triglycerides) Dihydroxyacetone Glycerol-3-phosphate Glycerol 3-phosphate Acyl CoA G3P-AT CoA-SH -
Lysophosphatidic Acid
Acyl CoA ABHD5 AG-AT CoA-SH AGK Phosphatidic Acid Monoacylglycerol CTP CDP-DAG PAP ADP ATP + Synthase PPi DGKE PNPLA2 Diacylglycerol CDP Diacylglycerol Triacylglycerol DGAT
PC-Cytidylyl CDP-PEth CHK transferase CMP Phospho- choline choline CDP-PChol PE-N-methyl CMP ATP ADP transferase SAH SAM
PC PE PG C18:0/C18:1 Chol PS Ser Ser Eth Déficit en AGK2 Sengers Syndrome (AR)
• Congenital Cataract Mayr et al. 2012 • Hypertrophic cardiomyopathy (cause of death) • Myopathy • Lactique Acidosis • Elevated 3-Methylglutaconic acid excretion • Mitochondrial abnormalities : • Decreased Adenine Nucleotide Translocator (ANT) expression • Defective Cardiolipin and ATP synthesis
Déficit en DGKE Atypical HUS type 1 (AR)
• Early onset Hemolytic Uremic Syndrome (< 1 y) Lemaire et al. 2013 • Persistent hypertension • Hematuria and proteinuria • Chronic renal failure with age Dihydroxyacetone Glycerol-3-phosphate Glycerol 3-phosphate Acyl CoA G3P-AT CoA-SH -
Lysophosphatidic Acid
Acyl CoA ABHD5 AG-AT CoA-SH AGK Phosphatidic Acid Monoacylglycerol CTP CDP-DAG PAP ADP ATP + Synthase PPi DGKE PNPLA2 Phosphoglycero- Diacylglycerol CDP Diacylglycerol Triacylglycerol phosphate DGAT Phse PC-Cytidylyl CDP-PEth Phosphatidyl- CHK transferase CMP Glycerol Phospho- choline choline CDP-PChol PE-N-methyl CMP ATP ADP transferase SAH SAM CH2 CH2 - O C O - PC PE PG O P O. P O . C18:0/C18:1 O. H H O O O Chol PS Ser Ser Taz CH CH2 Eth 2 CO CH CH CO
CH2 CH2 O O CO CO
Cardiolipin Déficit en Monolysocardiolipine acyl transférase (Tafazzin) Barth Syndrome (X-linked)
Bione et al. 1996 • Symptoms in infancy and childhood • Dilated cardiomyopathy (bi or left ventricular dilatation) • Muscle weaknesse, Neutropenia, Developmental delay • Variability in age of onset and course • No genotype/phenotype correlation • 3-Methylglutaric aciduria (type III): inconstant • Defective ATP synthesis • Blood screening test Dihydroxyacetone Glycerol-3-phosphate Glycerol 3-phosphate Acyl CoA G3P-AT CoA-SH -
Lysophosphatidic Acid
Acyl CoA ABHD5 AG-AT CoA-SH AGK Phosphatidic Acid Monoacylglycerol CTP CDP-DAG PAP ADP ATP + Synthase PPi DGKE PNPLA2 Phosphoglycero- Diacylglycerol CDP Diacylglycerol Triacylglycerol phosphate DGAT Phse PC-Cytidylyl CDP-PEth Phosphatidyl- CHK transferase CMP Glycerol Phospho- choline choline CDP-PChol PE-N-methyl CMP ATP ADP transferase SAH SAM CH2 CH2 - O C O - SERAC PC PE PG O P O. P O . C18:0/C18:1 O. H H O O O Chol PS Ser Ser Taz CH CH2 Eth 2 CO CH CH CO
CH2 CH2 O O CO CO
Cardiolipin Déficit en SERAC-1 MEGDEL Syndrome (AR)
Wortmann et al, 2012
• 3-METHYLGLUTACONIC ACIDURIA (Type III) • DEAFNESS • ENCEPHALOPATHY • LEIGH-LIKE SYNDROME •Lactic acidemia
• Psychomotor delay/regression in childhood • Spasticity or dystonia
•MRI : • Leigh syndrome •Cerebral and cerebellar atrophy DDHD1,2 + PLA2G6
COOH
Arachidonic Acid Déficit en PLA2g calcium-independante (PLA2G6) (AR)
INAD : Infantile Neuroaxonal dystrophie: Onset before 5y Cerebellar atrophy NO iron deposition Motor and mental Retardation Cerebellar ataxie 3 years 3 years Trunc hypotonia and spastic paraplegia Visual disturbances (Optic atrophy, nystagmus, strabism) MRI : cerebellar atrophy, Iron storage in globus pallidus and grey matter neuroaxonal spheroids
NBIA : Neurodegeneration with Brain Iron Accumulation Milder phenotype of INAD Cerebellar atrophy with iron deposits in pallida 9 years Variable age of onset (2-18 y) Encephalopathy in infancy to childhood , Neurodegeneration at adolescence
Dystonia/parkinson L-Dopa-responsive After 20 years Cerebellar atrophy, no iron deposits Pyramidal, psychiatric signs, cognitive decline Mutations en DDHD1 et DDHD2 Paraplégie spastique 28 et 54 (AR)
Tesson et al. 2012 Mixed spastic paraplegia : Schuurs-Hoeijmakers et al, 2012 • Early-onset (before 2y) • Progressive spasticity upper limbs+++ • Strabismus, dysarthria +/- dysphagia • Cognitive alterations • Variable severity of symptoms, independently from the nature of mutation
Basal ganglia MRI : Thin corpus calosum and subtle periventricular WM hyperintensities thalamus Spinal syrinx
NTE DDHD1,2 + Phospho- + glycerol PLA2G6
COOH
Arachidonic Acid Déficit en Neuropathy Target Esterase (NTE) Paraplégie spastique 39 (AR)
Rainier et al. 2008 Target for Organo-phosphorus induced delayed neuropathy (OPDN)
Onset in childhood or adulthood • Progressive spastic paraplegia in childhood • Motor axonopathy of lower and upper extremities • Muscle weakness • Motor nerve abnormalities / spared perepheral nerve MRI : Spinal cord atrophy and spared CNS
Disturbance of vesicular transport a long the axons
NTE DDHD1,2 + Phospho- + glycerol PLA2G6
Prostaglandins
COOH
Arachidonic Leukotriens Acid
CYP2U1
COOH COOH OH OH 20-HETE 19-HETE Mutations en Cytochrome P450 hydroxylase (CYP2U1) Paraplégie spastique 49 (AR)
Tesson et al. 2012
Onset between birth to 8 Y • Spastic paraplegia at upper limbs +/- dystonia • Discrete axonal neuropathy at the lower limbs • Cerebellar occulomotor disturbance (saccadic eye pursuit)
MRI : Thin corpus callosum white matter lesions Globus pallidus hypointensities (calcifications)-late Normal spine
NTE DDHD1,2 + Phospho- + glycerol PLA2G6
H2O PLC Fatty acid
Diacylglycerol
H O Prostaglandins DAGL 2 Fatty acid ABDH12 COOH 2-Arachidonoyl Leukotriens Glycerol Arachidonic Acid H2O Glycerol
CYP2U1
COOH COOH OH OH 20-HETE 19-HETE Déficit en a/b Hydrolase 12 (ABHD12) Syndrome de PHARC (AR)
Pseudo Refsum disease without phytanic acid elevation - Polyneurpathy - Hearing loss - Ataxia - Retinitis pigmentosa - Cataract
MRI :Cerebellar atrophy
Présentation hépatique des déficits de biosynthèse et remodelage des PL (Saudubray)
Neutral Lipid storage with myopathy, PNPLA2 deficiency Myopathy of proximal and distal muscles Assymetric Muscle Atrophy Hepatomegaly, liver steatosis (50%) Absence of ichthyosis
Chanarin Dorfman (ABHD5) Hepatomegaly with liver steatosis Cataract ,Deafness, Myopathy ,Developmental delay
Glycerol 3 phosphate dehydrogenase 1 deficiency : infantile hepatomegaly and hypertriglyceridemia Onset in the first months of life Asymptomatic soft hepatomegaly Transient hypertriglyceridemia, Normal with age liver dysfunction and progression of the fatty liver to fibrosis. Conclusions
Déficits de biosynthèse des lipides complexes : un nouveau groupe de MHM.
Les déficits de synthèse se situent à la frontière entre les MHM classiques et les maladies génétiques impliquant le métabolisme des protéines de structure.
Groupe de maladies en pleine expansion : nombreux gènes trés récemment décrits et d’autres probablement à venir.
Peu de cas décrits pour chaque déficit : déscription clinique temporaire
Le diagnostic repose principalement sur les analyses moléculaires et l’analyse lipidomique (plasma/fibro).
Frédéric SEDEL Giovanni STEVANIN Fanny MOCHEL Claude JARDEL Jean Marie SAUDUBRAY Christelle DEPIENNE Unité Neurométabolique bioclinique et génétique – Salpêtrière - Paris