Skip to main content
construction release_alert
Scholars@Duke will be undergoing maintenance April 11-15. Some features may be unavailable during this time.
cancel
Journal cover image

A functional substitution in the L-aromatic amino acid decarboxylase enzyme worsens somatic symptoms via a serotonergic pathway.

Publication ,  Journal Article
Khoury, S; Piltonen, MH; Ton, A-T; Cole, T; Samoshkin, A; Smith, SB; Belfer, I; Slade, GD; Fillingim, RB; Greenspan, JD; Ohrbach, R; Neely, GG ...
Published in: Ann Neurol
August 2019

OBJECTIVE: Heightened somatic symptoms are reported by a wide range of patients with chronic pain and have been associated with emotional distress and physical dysfunction. Despite their clinical significance, molecular mechanisms leading to their manifestation are not understood. METHODS: We used an association study design based on a curated list of 3,295 single nucleotide polymorphisms mapped to 358 genes to test somatic symptoms reporting using the Pennebaker Inventory of Limbic Languidness questionnaire from a case-control cohort of orofacial pain (n = 1,607). A replication meta-analysis of 3 independent cohorts (n = 3,189) was followed by functional validation, including in silico molecular dynamics, in vitro enzyme assays, and measures of serotonin (5-HT) plasma concentration. RESULTS: An association with the T allele of rs11575542 coding for an arginine to glutamine substitution in the L-aromatic amino acid decarboxylase (AADC) enzyme was replicated in a meta-analysis of 3 independent cohorts. In a combined meta-analysis of all cohorts, this association reached p = 6.43 × 10-8 . In silico studies demonstrated that this substitution dramatically reduces the conformational dynamics of AADC, potentially lowering its binding capacity to a cofactor. in vitro enzymatic assays showed that this substitution reduces the maximum kinetic velocity of AADC, hence lowering 5-HT levels. Finally, plasma samples from 90 subjects showed correlation between low 5-HT levels and heightened somatic symptoms. INTERPRETATION: Using functional genomics approaches, we identified a polymorphism in the AADC enzyme that contributes to somatic symptoms through reduced levels of 5-HT. Our findings suggest a molecular mechanism underlying the pathophysiology of somatic symptoms and opens up new treatment options targeting the serotonergic system. ANN NEUROL 2019;86:168-180.

Duke Scholars

Altmetric Attention Stats
Dimensions Citation Stats

Published In

Ann Neurol

DOI

EISSN

1531-8249

Publication Date

August 2019

Volume

86

Issue

2

Start / End Page

168 / 180

Location

United States

Related Subject Headings

  • Young Adult
  • Signal Transduction
  • Serotonin
  • Protein Structure, Secondary
  • Prospective Studies
  • Neurology & Neurosurgery
  • Middle Aged
  • Medically Unexplained Symptoms
  • Male
  • Humans
 

Citation

APA
Chicago
ICMJE
MLA
NLM
Khoury, S., Piltonen, M. H., Ton, A.-T., Cole, T., Samoshkin, A., Smith, S. B., … Diatchenko, L. (2019). A functional substitution in the L-aromatic amino acid decarboxylase enzyme worsens somatic symptoms via a serotonergic pathway. Ann Neurol, 86(2), 168–180. https://doi.org/10.1002/ana.25521
Khoury, Samar, Marjo H. Piltonen, Anh-Tien Ton, Tiffany Cole, Alexander Samoshkin, Shad B. Smith, Inna Belfer, et al. “A functional substitution in the L-aromatic amino acid decarboxylase enzyme worsens somatic symptoms via a serotonergic pathway.Ann Neurol 86, no. 2 (August 2019): 168–80. https://doi.org/10.1002/ana.25521.
Khoury S, Piltonen MH, Ton A-T, Cole T, Samoshkin A, Smith SB, et al. A functional substitution in the L-aromatic amino acid decarboxylase enzyme worsens somatic symptoms via a serotonergic pathway. Ann Neurol. 2019 Aug;86(2):168–80.
Khoury, Samar, et al. “A functional substitution in the L-aromatic amino acid decarboxylase enzyme worsens somatic symptoms via a serotonergic pathway.Ann Neurol, vol. 86, no. 2, Aug. 2019, pp. 168–80. Pubmed, doi:10.1002/ana.25521.
Khoury S, Piltonen MH, Ton A-T, Cole T, Samoshkin A, Smith SB, Belfer I, Slade GD, Fillingim RB, Greenspan JD, Ohrbach R, Maixner W, Neely GG, Serohijos AWR, Diatchenko L. A functional substitution in the L-aromatic amino acid decarboxylase enzyme worsens somatic symptoms via a serotonergic pathway. Ann Neurol. 2019 Aug;86(2):168–180.
Journal cover image

Published In

Ann Neurol

DOI

EISSN

1531-8249

Publication Date

August 2019

Volume

86

Issue

2

Start / End Page

168 / 180

Location

United States

Related Subject Headings

  • Young Adult
  • Signal Transduction
  • Serotonin
  • Protein Structure, Secondary
  • Prospective Studies
  • Neurology & Neurosurgery
  • Middle Aged
  • Medically Unexplained Symptoms
  • Male
  • Humans