Transcriptome Analysis of the Human Striatum in Tourette Syndrome

• Published in: Biological psychiatry (1969) Vol. 79; no. 5; pp. 372 - 382
• Main Authors: Lennington, Jessica B., Coppola, Gianfilippo, Kataoka-Sasaki, Yuko, Fernandez, Thomas V., Palejev, Dean, Li, Yifan, Huttner, Anita, Pletikos, Mihovil, Sestan, Nenad, Leckman, James F., Vaccarino, Flora M.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.03.2016
• Subjects: Acetylcholine - metabolism; Adult; Aged; Aged, 80 and over; Basal ganglia; DNA Copy Number Variations; Female; gamma-Aminobutyric Acid - metabolism; Gene Expression Profiling; Gene Regulatory Networks; Genome-Wide Association Study; Humans; Immune system; Interneuron; Interneurons - metabolism; Male; Middle Aged; Network; Nitric oxide synthase; NOS; Psychiatric/Mental Health; Putamen - metabolism; RNA-Seq; Sequence Analysis, RNA; Tourette Syndrome - genetics; Transcriptome; Basal ganglia; NOS; RNA-Seq; Network; Nitric oxide synthase; Immune system; Interneuron
• ISSN: 0006-3223; 1873-2402; 1873-2402
• DOI: 10.1016/j.biopsych.2014.07.018

Genome-wide association studies have not revealed any risk-conferring common genetic variants in Tourette syndrome (TS), requiring the adoption of alternative approaches to investigate the pathophysiology of this disorder. We obtained the basal ganglia transcriptome by RNA sequencing in the caudate and putamen of nine TS and nine matched normal control subjects. We found 309 downregulated and 822 upregulated genes in the caudate and putamen (striatum) of TS individuals. Using data-driven gene network analysis, we identified 17 gene coexpression modules associated with TS. The top-scoring downregulated module in TS was enriched in striatal interneuron transcripts, which was confirmed by decreased numbers of cholinergic and gamma-aminobutyric acidergic interneurons by immunohistochemistry in the same regions. The top-scoring upregulated module was enriched in immune-related genes, consistent with activation of microglia in patients’ striatum. Genes implicated by copy number variants in TS were enriched in the interneuron module, as well as in a protocadherin module. Module clustering revealed that the interneuron module was correlated with a neuronal metabolism module. Convergence of differential expression, network analyses, and module clustering, together with copy number variants implicated in TS, strongly implicates disrupted interneuron signaling in the pathophysiology of severe TS and suggests that metabolic alterations may be linked to their death or dysfunction.