A possible role for mitochondrial-derived peptides humanin and MOTS-c in patients with Q fever fatigue syndrome and chronic fatigue syndrome, by Ruud PH Raijmakers, Anne F M Jansen, Stephan P Keijmel, Rob ter Horst, Megan E Roerink, Boris Novakovic, Leo AB Joosten, Jos W M van der Meer, Mihai G Netea and Chantal P Bleeker-Roversen, in Journal of Translational Medicine 2019 17:157 [https://doi.org/10.1186/s12967-019-1906-3]
Research abstract:
Background:
Q fever fatigue syndrome (QFS) is a well-documented state of prolonged fatigue following around 20% of acute Q fever infections.
General schema showing the relationships of the genome, transcriptome, proteome, and metabolome (lipidome).
It has been hypothesized that low grade inflammation plays a role in its aetiology. In this study, we aimed to identify transcriptome profiles that could aid to better understand the pathophysiology of QFS.
Methods:
RNA of monocytes was collected from QFS patients (n = 10), chronic fatigue syndrome patients (CFS, n = 10), Q fever seropositive controls (n = 10), and healthy controls (n = 10) who were age- (± 5 years) and sex-matched. Transcriptome analysis was performed using RNA sequencing.
Results:
Mitochondrial-derived peptide (MDP)-coding genes MT-RNR2 (humanin) and MT-RNR1 (MOTS-c) were differentially expressed when comparing QFS (− 4.8 log2-fold-change P = 2.19 × 10−9 and − 4.9 log2-fold-change P = 4.69 × 10−8), CFS (− 5.2 log2-fold-change, P =3.49 × 10−11 − 4.4 log2-fold-change, P = 2.71 × 10−9), and Q fever seropositive control (− 3.7 log2-fold-change P = 1.78 × 10−6 and − 3.2 log2-fold-change P = 1.12 × 10−5) groups with healthy controls, resulting in a decreased median production of humanin in QFS patients (371 pg/mL; Interquartile range, IQR, 325–384), CFS patients (364 pg/mL; IQR 316–387), and asymptomatic Q fever seropositive controls (354 pg/mL; 292–393).
Conclusions:
Expression of MDP-coding genes MT-RNR1 (MOTS-c) and MT-RNR2 (humanin) is decreased in CFS, QFS, and, to a lesser extent, in Q fever seropositive controls, resulting in a decreased production of humanin. These novel peptides might indeed be important in the pathophysiology of both QFS and CFS.
