Download Oxidative Phosphorylation Disease

Georgia Neurological Society
Annual Meeting 2011
Neurometabolic Disease
in Adult Neurologic Practice
NADH
NAD+
CoQ10
H+
III
V
IV
C
ATP
ADP
II
I
H+
H+
H2O O2
H+
H+
Research Grants
2009-2010
Department of Defense, Grant: Mitochondrial Defects in
Autism AR080046
2009-2012
Department of Defense, Grant: Mechanisms of mitochondrial
defects in Gulf War Syndrome GW080138
2010-2013
Department of Defense, Grant: Mechanisms of mitochondrial
dysfunction in autism. Combined laboratory analysis and
functional MRI assessments. AR093329
2010-2011
PND Association Research Grant Program titled
"Keratinocytes and / or melanocytes as a cell source for the
enzyme assay of tyrosine hydroxylase"
2005-2010
Subcontract for NIH HPA grant (UO1 AI057565):
Hyperphenylalaninemia in cerebral malaria
Cerebral Folate Defects
Mitochondrial Diseases
Treatment
Cerebral Folate Defects: Definition
What are cerebral folate defects and how are they diagnosed?
Any neurological syndrome associated with a low CSF 5methyltetrahydrofolate (5-MTHF) (<50 mmol/L) in the presence of
NORMAL peripheral folate status.
(Dev Med Child Neurol 46:843;2004)
If diagnosed early enough, these defects are treatable.
Cerebral Folate Defects: Causes
What causes cerebral folate defects?
Genetic Disease
Drugs
Autoimmune Disease
Cerebral folate defects affect ALL AGE GROUPS.
For more detailed information about various conditions causing CFD,
email me at:
[email protected]
Hyland K, Shoffner J, Heales SJ.
J Inherit Metab Dis. 2010 Oct;33(5):563-70
Cerebral Folate Defects: Symptoms
What are the symptoms of CFD?
Demyelination
Epilepsy (essentially all types)
Movement disorders
Neuropathies
Neurobehavioral (autism) and psychiatric disorders
Cognitive impairment and mental retardation
Spasticity
NOT ANEMIA IN MOST CASES !!!
Symptoms evolve over time
Cerebral Folate Defects: Mechanisms
Plasma
5-MTHF
Choroid Plexus
F
R
1
ATP
CSF
R
F
C
5-MTHF
3-4x
Higher
than
plasma
Folate Polyglutamate
Pool
5-MTHF = 5-methyltetrahydrofolate; FR1 = Folate receptor 1;
RFC = Reduced Folate Carrier
Cerebral Folate Defects: Causes
Drugs
(e.g. L-Dopa,
methotrexate)
Autoimmune
Disease
(Antibodies to Folate
Receptor)
Genetic
Disease
(e.g. Mitochondrial
Disease, FOLR1
mutations, and many
more)
Mitochondrial Disease
Not just a defect in ATP production
ATP production
Free radical generation
Apoptosis
Mitochondrial/Endoplasmic Reticulum
Calcium regulation
Effects on other metabolic pathways
Toxic interactions
Glucose + Fatty Acids = ATP!
GLYCOGEN
Medium Chain (C8-C12)
Long Chain (C14-C20)
Short Chain (C4-C6)
GLYCOLYSIS
Fatty Acids
Alanine
Pyruvate
Lactate
L-Carnitine
CPT I
CPT II
VLCAD
Pyruvate
Long
Chain
(C14-C20)
Acetyl -CoA
PDHC
Medium Chain
Acetyl -CoA
TCA
NADH
NAD+
I
H+
II
CoQ10
H+
III
ADP
ATP
H+
ATP
ADP
A
N
V
IV
C
-oxidation
H+
H2O O2
Short Chain
T
H+
P
O
R
ATP ADP
HOW IT REALLY WORKS:
SUPERCOMPLEXES
Stability and Assembly
J Biol Chem 279;36349,2004
Complex I
Complex III
Complex IV
Supercomplexes + Monomeric OXPHOS Enzymes
Blue Native Electrophoresis
I1III2IVn + CVn
I1III2IV1
CI1CIII2
The higher molecular weight bands may be
oligomeric forms of Complex V.
*
*
Complex I
Complex III
Dimeric CV
Monomeric CV
Complex IV
Dimeric CIII
Monomeric CIV
Normal Patient 1 Patient 3
Pediatric
Adult
SURF1
SURF1
Complex IV: CLEAR NATIVE GEL
Monomeric OXPHOS Enzyme Assembly
Monomeric Complex IV
*
*
Normal Patient 2 Patient 3 Normal
Pediatric
Adult
Monomeric Complex IV
*
*
Normal Patient 1 Patient 2 Normal
Pediatric Pediatric
Mitochondrial Disease: Treatment
Irreversible
Reversible
Normal
Mitochondrial Dysfunction: Threshold Expression
Normal
OXPHOS
Function
Abnormal
Normal
Phenotype
Cerebral Folate Deficiency: Adolescent
Mitochondrial disease: Adolescent
•
•
•
Kearnes-Sayre Syndrome
Sporadic mtDNA Deletion
Abnormal choroid plexus
Progressive loss of balance and motor
function. Became confined to bed over
several months.
CSF 5-MTHF 8 (NL 50-120)
CFD observed in over 80% of Kearnes-Sayre
cases
Genetic Diagnosis
Rapidly Evolving:
mtDNA ----16,569 nucleotides
Nuclear DNA----~1400 genes
Next Generation Sequencing
Cerebral Folate Deficiency: Adolescent
Mitochondrial disease: Adolescent
Kearnes-Sayre Syndrome
Cerebral Folate Deficiency: Adolescent
Mitochondrial disease: Adolescent
Treatment with Leucovorin (Folinic acid) 25mg po
bid.
Resolution of symptoms and return to baseline:
Walking independently, going to school, complete
self care
Fatigue and Myalgias
Cerebral Folate Deficiency: Adult Onset
Mitochondrial disease: Adult Onset
41 year old woman
20-25 years: Less endurance than peers
26 years – present:
Progressive fatigue, severely limiting activity
36 years: Distal pain, paresthesias in hands and feet; Cognitive
complaints (calculations, word retrieval, memory)
Brain and spinal cord imaging: Negative
EMG/NCV: Negative
Rheumatological Testing: Negative
Two sons: One healthy (9 years old). One with muscle weakness, leg
cramps, myopathic EMG, normal CPK.
Exercise Testing:
Essential for diagnosing and
following fatigue
Anaerobic Threshold (AT)
Patient: 10 ml/kg/min
Predicted: >11 ml/kg/min
Peak VO2 Max
Patient: 1.44 L/min
Predicted: ≥ 1.83 L/Min
Predicted normal ranges:
Based on age, gender, weight, height, BMI)
Normal Pulmonary Function Testing
Exercise Testing: Met-Test
Fatigue and Myalgias
Cerebral Folate Deficiency: Adult Onset
Mitochondrial disease: Adult Onset
Muscle Biopsy:
Sarcoplasmic Masses
Epidermal Nerve Fiber Density: Decreased consistent with a small fiber neuropathy
CSF 5-methyltetrahydrofolate: 25 (NL >50 mmol/L)
CSF protein: 45 (NL 15-45)
Mitochondrial Disease
CSF Alanine: 44.9 µmol/L (NL 20.8-35.4 µmol/L)
Muslce Biochemistry: Complex I and Complex III Defect
Fatigue and Myalgias
Cerebral Folate Deficiency: Adult Onset
Mitochondrial disease: Adult Onset
Genetics:
Mitochondrial DNA (nuclear and mtDNA)
Pending
FOLR1 (Folate Receptor)
Single mutation in Exon 3: c.352C>T P.Q118X
Stop codon producing a truncated protein
May increase susceptibility to developing a cerebral folate defect
Fatigue and Myalgias
Cerebral Folate Deficiency: Adult Onset
Mitochondrial disease: Adult Onset
Folinic acid Treatment:
25mg PO every 8 hours
Improved neuropathic symptoms:
Pain and dysaesthesias
Improved episodes with difficulty thinking (calculations, word retrieval, memory)
Adult Onset Fatigue and
Myalgias Syndromes
A retrospective analysis of evaluations performed on 62 patients
was performed.
36 adults (>19 years) (11 male; 25 female)
Mean age ± SD = 39.2 ± 9.2 years;
Median = 39.5 years; Range 20-60 years
ADULT
FATIGUE + MYALGIAS
Weakness
17% (6/36)
Increased CPK
17% (6/36)
Rhabdomyolysis
14% (5/36)
Abnormal Metabolic Testing
28% (10/36)
Abnormal OXPHOS Enzymology
83% (30/36)
Abnormal OXPHOS Western Blot
48% (14/29)
Abnormal Muscle CoQ10 (Deficiency)
41% (7/17)
Abnormal mtDNA Copy Number
7% (2/27)
Pathogenic mtDNA mutations
8% (2/26)
Provisionally Pathogenic mtDNA mutation
27% (7/26)
Fatty acid oxidation diseases, glycogen storage diseases,
autoimmune disease, congenital myopathies and muscular
dystrophies were excluded.
Mitochondrial Disease Treatment
Coenzyme Q10:
Mildly effective
Exception: Primary (genetic) CoQ10 deficiency.
Response can be dramatic.
Clinical investigations:
EPI-743 (Edison Pharmaceutical): Effect not clear in Leigh Disease (2
patients). Drug currently under study
Other companies: Collaboration moving forward on agents showing
improvements in cells with mitochondrial dysfunction
Mitochondrial ATP Generation:
Medical Neurogenetics Research
Mitochondrial and Cytoplasmic Luciferase
Georgia Neurological Society
Annual Meeting 2011
Neurometabolic Disease
in Adult Neurologic Practice
NADH
NAD+
CoQ10
H+
III
V
IV
C
ATP
ADP
II
I
H+
H+
H2O O2
H+
Thank You!
H+