Cosima Rhein1, Martin Reichel2, Marcel Kramer3, Andrea Rotter2, Bernd Lenz2, Christiane Mühle2, Erich Gulbins4, Johannes Kornhuber2. 1. Department of Psychiatry and Psychotherapy, University Hospital, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Schwabachanlage 6, D-91054 Erlangen, Germany; Department of Medicine and Stony Brook Cancer Center, Stony Brook University, Stony Brook, New York, USA. Electronic address: Cosima.Rhein@uk-erlangen.de. 2. Department of Psychiatry and Psychotherapy, University Hospital, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Schwabachanlage 6, D-91054 Erlangen, Germany. 3. Department of Anesthesiology and Intensive Care Medicine, Jena University Hospital, Jena, Germany; Genome Analysis, Leibniz Institute on Aging - Fritz Lipmann Institute, Jena, Germany. 4. Department of Molecular Biology, University of Duisburg-Essen, Essen, Germany.
Abstract
BACKGROUND: Major depressive disorder (MDD) is a psychiatric disorder characterized by key symptoms that include depressed mood and a loss of interest and pleasure. A recently developed pathogenic model of MDD involves disturbed neurogenesis in the hippocampus, where the acid sphingomyelinase (ASM)/ceramide system plays an important role and is proposed as a molecular target for antidepressant action. Because alternative splicing of SMPD1 mRNA, coding for ASM, is relevant for the regulation of ASM enzymatic activity, we investigated the frequency of alternatively spliced ASM isoforms in peripheral blood cells of MDD patients versus healthy controls. METHODS: Because the full-length transcript variant 1 of SMPD1 (termed ASM-1) is the only known form within the splicing pattern that encodes an enzymatically fully active ASM, we determined a fraction of splice isoforms deviating from ASM-1 using PCR amplification and capillary electrophoresis with laser-induced fluorescence analysis. RESULTS: ASM alternative splicing events occurred significantly less frequently in MDD patients compared to healthy subjects. After 5 days of antidepressant treatment, the frequency of alternatively spliced ASM isoforms decreased in those patients who were treated with a functional inhibitor of ASM activity (FIASMA) but remained constant in MDD patients treated with other antidepressant drugs. This effect was more pronounced when healthy male volunteers were treated with the FIASMAs fluoxetine or paroxetine, in contrast to a placebo group. LIMITATIONS: Patients were treated with different antidepressant drugs, depending on individual parameters and disease courses. CONCLUSIONS: This study shows that the ASM alternative splicing pattern could be a biological target with diagnostic relevance and could serve as a novel biomarker for MDD.
BACKGROUND: Major depressive disorder (MDD) is a psychiatric disorder characterized by key symptoms that include depressed mood and a loss of interest and pleasure. A recently developed pathogenic model of MDD involves disturbed neurogenesis in the hippocampus, where the acid sphingomyelinase (ASM)/ceramide system plays an important role and is proposed as a molecular target for antidepressant action. Because alternative splicing of SMPD1 mRNA, coding for ASM, is relevant for the regulation of ASM enzymatic activity, we investigated the frequency of alternatively spliced ASM isoforms in peripheral blood cells of MDDpatients versus healthy controls. METHODS: Because the full-length transcript variant 1 of SMPD1 (termed ASM-1) is the only known form within the splicing pattern that encodes an enzymatically fully active ASM, we determined a fraction of splice isoforms deviating from ASM-1 using PCR amplification and capillary electrophoresis with laser-induced fluorescence analysis. RESULTS:ASM alternative splicing events occurred significantly less frequently in MDDpatients compared to healthy subjects. After 5 days of antidepressant treatment, the frequency of alternatively spliced ASM isoforms decreased in those patients who were treated with a functional inhibitor of ASM activity (FIASMA) but remained constant in MDDpatients treated with other antidepressant drugs. This effect was more pronounced when healthy male volunteers were treated with the FIASMAs fluoxetine or paroxetine, in contrast to a placebo group. LIMITATIONS: Patients were treated with different antidepressant drugs, depending on individual parameters and disease courses. CONCLUSIONS: This study shows that the ASM alternative splicing pattern could be a biological target with diagnostic relevance and could serve as a novel biomarker for MDD.
Authors: Cosima Rhein; Stefan Löber; Peter Gmeiner; Erich Gulbins; Philipp Tripal; Johannes Kornhuber Journal: J Neural Transm (Vienna) Date: 2018-09-06 Impact factor: 3.575
Authors: Iulia Zoicas; Christiane Mühle; Anna K Schmidtner; Erich Gulbins; Inga D Neumann; Johannes Kornhuber Journal: Cells Date: 2020-05-17 Impact factor: 6.600
Authors: Cosima Rhein; Iulia Zoicas; Lena M Marx; Stefanie Zeitler; Tobias Hepp; Claudia von Zimmermann; Christiane Mühle; Tanja Richter-Schmidinger; Bernd Lenz; Yesim Erim; Martin Reichel; Erich Gulbins; Johannes Kornhuber Journal: Int J Mol Sci Date: 2021-05-27 Impact factor: 5.923