Open Access Open Badges Research article

ErbB3 mRNA leukocyte levels as a biomarker for major depressive disorder

Elena Milanesi1, Alessandra Minelli1, Nadia Cattane1, Annamaria Cattaneo1, Cristina Mora1, Alessandro Barbon1, Alessandra Mallei2, Maurizio Popoli2, Vincenzo Florio3, Andreas Conca3, Stefano Bignotti4 and Massimo Gennarelli15*

Author Affiliations

1 Department of Biomedical Sciences and Biotechnologies - Biology and Genetic Division, University of Brescia, Viale Europa 11, Brescia, 25123, Italy

2 Department of Pharmacological Sciences, Center of Neuropharmacology, University of Milano, Via Balzaretti 9, Milano, Italy

3 Department of Psychiatry, Central Hospital of Bolzano, Bolzano, Italy

4 Psychiatric Unit, I.R.C.C.S. “San Giovanni di Dio” - Fatebenefratelli, via Pilastoni 4, Brescia, 25123, Italy

5 Genetic Unit, I.R.C.C.S. “San Giovanni di Dio” - Fatebenefratelli, Via Pilastroni, 4, Brescia, 25123, Italy

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BMC Psychiatry 2012, 12:145  doi:10.1186/1471-244X-12-145

Published: 18 September 2012



In recent years, the identification of peripheral biomarkers that are associated with psychiatric diseases, such as Major Depressive Disorder (MDD), has become relevant because these biomarkers may improve the efficiency of the differential diagnosis process and indicate targets for new antidepressant drugs. Two recent candidate genes, ErbB3 and Fgfr1, are growth factors whose mRNA levels have been found to be altered in the leukocytes of patients that are affected by bipolar disorder in a depressive state. On this basis, the aim of the study was to determine if ErbB3 and Fgfr1 mRNA levels could be a biomarkers of MDD.


We measured by Real Time PCR ErbB3 and Fgfr1 mRNA expression levels in leukocytes of MDD patients compared with controls. Successively, to assess whether ErbB3 mRNA levels were influenced by previous antidepressant treatment we stratified our patients sample in two cohorts, comparing drug-naive versus drug-free patients. Moreover, we evaluated the levels of the transcript in MDD patients after 12 weeks of antidepressant treatment, and in prefrontal cortex of rats stressed and treated with an antidepressant drug of the same class.


These results showed that ErbB3 but not Fgfr1 mRNA levels were reduced in leukocytes of MDD patients compared to healthy subjects. Furthermore, ErbB3 levels were not affected by antidepressant treatment in either human or animal models


Our data suggest that ErbB3 might be considered as a biomarker for MDD and that its deficit may underlie the pathopsysiology of the disease and is not a consequence of treatment. Moreover the study supports the usefulness of leukocytes as a peripheral system for identifying biomarkers in psychiatric diseases.

Major Depressive Disorder MDD; ErbB3; Fgfr1; Biomarkers; Leukocytes