Application of an ex vivo cellular model of circadian variation for bipolar disorder research: a proof of concept study

• Published in: Bipolar disorders 2013-09, Vol.15 (6), p.694-700
• Main Authors: Bamne, Mikhil N, Ponder, Christine A, Wood, Joel A, Mansour, Hader, Frank, Ellen, Kupfer, David J, Young, Michael W, Nimgaonkar, Vishwajit L
• Format: Article
• Language: English
• Subjects: Adult; Antiemetics - pharmacology; ARNTL Transcription Factors - genetics; ARNTL Transcription Factors - metabolism; biorhythm; bipolar disorder; Bipolar Disorder - pathology; Bipolar Disorder - physiopathology; BmalI; Cell Line; circadian; Dexamethasone - pharmacology; Female; fibroblast; Fibroblasts - drug effects; Gene Expression Regulation - drug effects; Humans; Male; Middle Aged; Time Factors; Transfection; Young Adult
• ISSN: 1398-5647; 1399-5618
• DOI: 10.1111/bdi.12095

Objectives Disruption of circadian function has been observed in several human disorders, including bipolar disorder (BD). Research into these disorders can be facilitated by human cellular models that evaluate external factors (zeitgebers) that impact circadian pacemaker activity. Incorporating a firefly luciferase reporter system into human fibroblasts provides a facile, bioluminescent readout that estimates circadian phase, while leaving the cells intact. We evaluated whether this system can be adapted to clinical BD research and whether it can incorporate zeitgeber challenge paradigms. Methods Fibroblasts from patients with bipolar I disorder (BD‐I) (n = 13) and controls (n = 12) were infected ex vivo with a lentiviral reporter incorporating the promoter sequences for Bmal1, a circadian gene to drive expression of the firefly luciferase gene. Following synchronization, the bioluminescence was used to estimate period length. Phase response curves (PRCs) were also generated following forskolin challenge and the phase response patterns were characterized. Results Period length and PRCs could be estimated reliably from the constructs. There were no significant case‐control differences in period length, with a nonsignificant trend for differences in PRCs following the phase‐setting experiments. Conclusions An ex vivo cellular fibroblast‐based model can be used to investigate circadian function in BD‐I. It can be generated from specific individuals and this could usefully complement ongoing circadian clinical research.