New treatment for Major Depression Modulators of Synaptogenesis and Neurogenesis for the treatment of Major Depression Advantages: A novel biological system has been found altered in brain samples from Depressive patients. The alteration of a particular cytokine, has been associated with depressive/anxious behavior in a transgenic mouse model over- expressing this target specifically in the brain. Lead compounds acting on some of this specific cytokine receptors are available.Background:Studying post-mortem brain samples (right prefrontal cortex) by genomic and proteomic methods, BRAINco hasfound a significant over-expression of a particular cytokine in depressive suicides compared to controls.Hypothesis:BRAINco has set up a Drug DEPRESSIONDiscovery Program focused on thisnew therapeutic target, which ispotentially implicated in thebiological bases of Depressionthrough its effects onneuroplasticity and cognition. ALTERATIONS IN: BRAIN PLASTICITY BRC Target HPA AXIS NEUROTRANSMISSION BEHAVIOR & COGNITION (HPA: Hypothalamic‐Pituitary Adrenal) Targeting specific cell signaling pathways modulated by BRAINco target, could render new antidepressant drugs.
Development Stage: Target ValidationANIMAL MODELBRAINco has generated a transgenic (TG) animal modelthat over-expresses the specific cytokine in the brain(Fig.1). Its comprehensive characterization has pointed itout as a good model for the development of newantidepressant drugs with novel mechanisms of action. Figure 1. Target expression in WT and TG mice, measuredBehavioral features: by in situ hybridization. At basal conditions… 50 OF 80 EPM 125 LDB % open arm distance/total Time spent in central area 40 100 Time spent in lit (s)TG mice showed a consistent anxious phenotype (Fig.2), 60 ** (mean±sem) mean±sem 30 75not attributable to locomotion impairment. No 40 * 50differences were found in tests classically used to 20 20 **determine antidepressant efficacy (such as tail 10 25 n=18 n=21 n=16 n=10 n=16 n=10suspension and forced swimming test). 0 WT TG 0 WT TG 0 WT TG 100 T‐Maze % entries into new armIn addition, the over-expression of the candidate induced 80a decrease in long term potentiation as well as deficits in 60the T-Maze test (Fig.3), being both results associated * 40with a cognitive impairment. 20 n=7 n=6 0 WT TG After an aversive stimulus… Figure 2. Anxiety-like responses (top) and cognition analysis (botton) of TG animals and WT siblings. OF: Open Field; EPM: Elevated Plus Maze; LDB: Light-Dark Box. TG mice presented important indications of a depressive-like ↓ 26 % ↓↓ 44 % behavior as assessed by Anhedonia test, after being exposed 80 *** *** to different aversive stimulus (chronic unpredictable mild % Sucrose preference stress and olfactory bulbectomy) (Fig.3). These results 60 suggest that TG mice show a higher sensitivity to develop depression after a stressful situation, than wild-types. 40 20 A B NSF Anhedonia 500 WT n=11 n=15 n=16 n=14 TG *** 80 ** Latency to feed (secs) ** % Sucrose preference 0 400 WT WTO TG TGO 60 300 Figure 3. Sucrose preference in WT and TG mice with and without olfactory bulbectomy (O). 40 200 100 20 After pharmacological treatment… n=7 n=7 n=7 n=7 n=11 n=15 n=7 n=16 n=14 n =7 0 0 -Flx +FlxTG mice exhibited a higher sensitivity to chronic TO X T TG O X W FL FL TG W TO O TGFluoxetine treatment, measured in normal conditions, as W Figure 4. Chronic Fluoxetine treatment in WT and TG animals (A) under basalwell as after Olfactory Bulbectomy (Fig.4). conditions (measure by NSF (Novelty Supressed Feeding) test) and (B) in bulbectomized animals (measuring sucrose preference or anhedonia).
Development Stage: Target Validation Biochemical characterization:TG mice overexpressing the target showed importantalterations in phosphoproteins implicated in dendriteformation, synaptogenesis and regulation of actincytoskeleton.The over-expression of BRAINco target in hippocampus,induced significant changes in proteins previously foundaltered in Depression such as, Wnt, BDNF, CREB and β-catenin (Fig.5).All these data showed the implication of BRAINco target incrucial biological processes found altered in Depression. Figure 5. Cell signaling pathways affected in BRAINco TG model. Characterization of Neurogenesis: The overexpression of BRAINco target, induced a decrease in both, cell proliferation (measured by BrdU incorporation) and neurogenesis (Dcx labeled cells). Interestingly, KO mice for this target, showed a significant increase in hippocampal cellFigure 6. BrdU positive cells in TG and KO mouse models, compared tothe respective WT animals. proliferation (Fig.6). TG mice exhibit several features similar to those observed in human Depressive patients. Therefore, BRAINco TG mice could be considered as a novel animal model to study Depression and to test the effectiveness of new drugs as well as existing compounds modulating the system. FINDING OF NEW CHEMICAL ENTITIESThe main objective of this project is the development of a novel therapy for Depression by finding new drugs directedto a new target found altered in human specimens. For this purpose, we tested the effect of BRAINco target indifferent cellular systems in order to set up assays suitable for High-Throughput Screening.Different assays including cell proliferation, migration, differentiation and survival of new neurons are being set up,using human neural progenitor cells. BIOMARKERSBRAINco therapeutic target is a secreted cytokine measurable in human serum. A biomarker discovery program isbeing set up in order to investigate the alteration of target expression levels in non-invasive samples of the animalmodel, as well as in Depressive patients. The final purpose is to use this biomarker as patient selection criteria.
Summary Depression is a devastating disorder with high prevalence and mortality, resulting in massive socioeconomic burden (200 Millions in 2010). Current antidepressant treatments are limited by their efficacy and delay onset of action. Therefore, new therapies based on novel mechanisms of action are urgently needed. In 2008, BRAINco discovered that a specific cytokine was significantly over-expressed in the prefrontal cortex of depressive patients, which became a novel promising therapeutic target for drug discovery. With the purpose of functionally validate the target, a transgenic mouse which over-expressed the cytokine in the brain was generated. A comprehensive characterization of this mouse showed a consistent anxious-like behavior and cognitive impairment in basal conditions, combined with a depressive-like phenotype after a stressful event, which was reversed by chronic antidepressant treatment. Therefore, this transgenic mouse could be considered as a non-classical animal model of Depression, which may be a very valuable tool for the development of new antidepressants with novel mechanisms of action. BRAINco team is also developing a cell based High Throughput Screening program with human neuronal progenitor cells, to look for new chemical entities targeting the system. In addition, a biomarker program is ongoing. The objective is to identify non-invasive biomarkers specific to the mechanism of action of BRAINco compounds and that could be used for patient selection. BRAINco has already filed a Patent application on these results. BRAINco Biopharma S.L Edificio 504. Parque tecnológico de Vizcaya | 48160 Derio (Bilbao). Vizcaya. Spain | Telf: +34 94 4064525 | Fax: +34 94 406 4526 firstname.lastname@example.org | www.brainco.es