Metabolic consequences of mitochondrial coenzyme A deficiency in patients with PANK2 mutations.
Pantothenate kinase-associated neurodegeneration (PKAN) is a rare, inborn error of metabolism characterized by iron accumulation in the basal ganglia and by the presence of dystonia, dysarthria, and retinal degeneration. Mutations in pantothenate kinase 2 (PANK2), the rate-limiting enzyme in mitochondrial coenzyme A biosynthesis, represent the most common genetic cause of this disorder. How mutations in this core metabolic enzyme give rise to such a broad clinical spectrum of pathology remains a mystery. To systematically explore its pathogenesis, we performed global metabolic profiling on plasma from a cohort of 14 genetically defined patients and 18 controls. Notably, lactate is elevated in PKAN patients, suggesting dysfunctional mitochondrial metabolism. As predicted, but never previously reported, pantothenate levels are higher in patients with premature stop mutations in PANK2. Global metabolic profiling and follow-up studies in patient-derived fibroblasts also reveal defects in bile acid conjugation and lipid metabolism, pathways that require coenzyme A. These findings raise a novel therapeutic hypothesis, namely, that dietary fats and bile acid supplements may hold potential as disease-modifying interventions. Our study illustrates the value of metabolic profiling as a tool for systematically exploring the biochemical basis of inherited metabolic diseases.
Laboratory of Clinical Pathology and Medical Genetics IRCCS Foundation Neurological Institute C.Besta, Milan, Italy.
Valerio
V
Leoni
Laura
L
Strittmatter
Giovanna
G
Zorzi
Federica
F
Zibordi
Sabrina
S
Dusi
Barbara
B
Garavaglia
Paola
P
Venco
Claudio
C
Caccia
Amanda L
AL
Souza
Amy
A
Deik
Clary B
CB
Clish
Marco
M
Rimoldi
Emilio
E
Ciusani
Enrico
E
Bertini
Nardo
N
Nardocci
Vamsi K
VK
Mootha
Valeria
V
Tiranti
D000293:Adolescent; D000328:Adult; D001647:Bile Acids and Salts / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D018389:Codon, Nonsense; D003065:Coenzyme A / Q000096:biosynthesis / Q000172:deficiency* / Q000235:genetics; D015331:Cohort Studies; D005260:Female; D006801:Humans; D019189:Iron Metabolism Disorders; D019344:Lactic Acid / Q000097:blood; D050356:Lipid Metabolism / Q000235:genetics; D052439:Lipid Metabolism Disorders / Q000235:genetics / Q000378:metabolism; D008297:Male; D055442:Metabolome; D008928:Mitochondria / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D019150:Neuroaxonal Dystrophies / Q000175:diagnosis / Q000201:enzymology / Q000378:metabolism*; D006211:Pantothenate Kinase-Associated Neurodegeneration / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D010205:Pantothenic Acid / Q000097:blood; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics*; D013109:Sphingomyelins / Q000097:blood; D055815:Young Adult
D001647:Bile Acids and Salts; D018389:Codon, Nonsense; D013109:Sphingomyelins; D010205:Pantothenic Acid; D019344:Lactic Acid; D017853:Phosphotransferases (Alcohol Group Acceptor); C023088:pantothenate kinase; D003065:Coenzyme A