Mutations in UCP2 in congenital hyperinsulinism reveal a role for regulation of insulin secretion.
Although the most common mechanism underlying congenital hyperinsulinism is dysfunction of the pancreatic ATP-sensitive potassium channel, the pathogenesis and genetic origins of this disease remains largely unexplained in more than half of all patients. UCP2 knockout mice exhibit an hyperinsulinemic hypoglycemia, suggesting an involvement of UCP2 in insulin secretion. However, a possible pathogenic role for UCP2 protein in the development of human congenital hyperinsulinism or of any human disease has not yet been investigated. We studied ten children exhibiting congenital hyperinsulinism, without detectable mutations in the known congenital hyperinsulinism-causing genes. Parental-inherited heterozygous UCP2 variants encoding amino-acid changes were found in two unrelated children with congenital hyperinsulinism. Functional assays in yeast and in insulin-secreting cells revealed an impaired activity of UCP2 mutants. Therefore, we report the finding of UCP2 coding variants in human congenital hyperinsulinism, which reveals a role for this gene in the regulation of insulin secretion and glucose metabolism in humans. Our results show for the first time a direct association between UCP2 amino acid alteration and human disease and highlight a role for mitochondria in hormone secretion.
González-Barroso
M Mar
MM
Université Paris Descartes Site Necker-enfants Malades, CNRS UPR 9078 BIOTRAM, Paris, France.
Giurgea
Irina
I
Bouillaud
Fredéric
F
Anedda
Andrea
A
Bellanné-Chantelot
Christine
C
Hubert
Laurence
L
de Keyzer
Yves
Y
de Lonlay
Pascale
P
Ricquier
Daniel
D
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D044903:Congenital Hyperinsulinism / Q000235:genetics*; D017124:Conserved Sequence; D004252:DNA Mutational Analysis; D005260:Female; D005947:Glucose / Q000494:pharmacology; D006579:Heterozygote; D006801:Humans; D007223:Infant; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D050417:Insulin-Secreting Cells / Q000187:drug effects / Q000378:metabolism; D007473:Ion Channels / Q000737:chemistry / Q000235:genetics*; D008297:Male; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D024101:Mitochondrial Proteins / Q000737:chemistry / Q000235:genetics*; D008969:Molecular Sequence Data; D050505:Mutant Proteins / Q000378:metabolism; D020125:Mutation, Missense / Q000235:genetics*; D010375:Pedigree; D011522:Protons; D051381:Rats; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000378:metabolism; D013104:Spheroplasts / Q000187:drug effects / Q000378:metabolism; D000071246:Uncoupling Protein 2
D007328:Insulin; D007473:Ion Channels; D024101:Mitochondrial Proteins; D050505:Mutant Proteins; D011522:Protons; C000604389:UCP2 protein, human; C000604390:Ucp2 protein, mouse; C000604391:Ucp2 protein, rat; D000071246:Uncoupling Protein 2; D005947:Glucose