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Research Project
Modulation of BDNF effects by adenosine: a new strategy for schizophrenia treatment - Adenosinergic signaling as a new pharmacological target for schizophrenia treatment
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A small TAT-TrkB peptide prevents BDNF receptor cleavage and restores synaptic physiology in Alzheimer's disease
Publication . Fonseca-Gomes, João; Costa-Coelho, Tiago; Ferreira-Manso, Mafalda; Inteiro-Oliveira, Sara; Vaz, Sandra H.; Alemãn-Serrano, Nuno; Atalaia Barbacena, Henrique; Ribeiro Rodrigues, Leonor; Ramalho, Rita Mira; Climaco Pinto, Rui; Vicente Miranda, Hugo; Tanqueiro, Sara; de Almeida-Borlido, Carolina; Ramalho, Maria João; Miranda-Lourenço, Catarina; Belo, Rita F.; Ferreira, Catarina B.; Neves, Vera; Rombo, Diogo M.; Viais, Ricardo; Umemori, Juzoh; Martins, Ivo C.; Jerónimo-Santos, André; Caetano, António; Manso, Nuno; Mäkinen, Petra; Marttinen, Mikael; Takalo, Mari; Bremang, Michael; Pike, Ian; Haapasalo, Annakaisa; Loureiro, Joana A.; Pereira, Maria Carmo; Santos, Nuno C.; Outeiro, Tiago; Castanho, Miguel A. R. B.; Fernandes, Adelaide; Hiltunen, Mikko; Duarte, Carlos B.; Castrén, Eero; De Mendonça, Alexandre; Sebastião, Ana M; Rodrigues, Tiago M.; Diógenes, Maria José
In Alzheimer's disease (AD), amyloid β (Aβ)-triggered cleavage of TrkB-FL impairs brain-derived neurotrophic factor (BDNF) signaling, thereby compromising neuronal survival, differentiation, and synaptic transmission and plasticity. Using cerebrospinal fluid and postmortem human brain samples, we show that TrkB-FL cleavage occurs from the early stages of the disease and increases as a function of pathology severity. To explore the therapeutic potential of this disease mechanism, we designed small TAT-fused peptides and screened their ability to prevent TrkB-FL receptor cleavage. Among these, a TAT-TrkB peptide with a lysine-lysine linker prevented TrkB-FL cleavage both in vitro and in vivo and rescued synaptic deficits induced by oligomeric Aβ in hippocampal slices. Furthermore, this TAT-TrkB peptide improved the cognitive performance, ameliorated synaptic plasticity deficits and prevented Tau pathology progression in vivo in the 5XFAD mouse model of AD. No evidence of liver or kidney toxicity was found. We provide proof-of-concept evidence for the efficacy and safety of this therapeutic strategy and anticipate that this TAT-TrkB peptide has the potential to be a disease-modifying drug that can prevent and/or reverse cognitive deficits in patients with AD.
Challenges of BDNF-based therapies : from common to rare diseases
Publication . Miranda-Lourenço, Catarina; Ribeiro Rodrigues, Leonor; Fonseca-Gomes, João; Tanqueiro, Sara; Belo, Rita F.; Ferreira, Catarina B.; Rei, Nádia; Ferreira-Manso, Mafalda; de Almeida-Borlido, Carolina; Costa-Coelho, Tiago; Freitas, Céline; Zavalko, Svitlana; Mouro, Francisco; Sebastião, Ana M; Xapelli, Sara; Rodrigues, Tiago M.; Diógenes, Maria José
Neurotrophins are a well-known family of neurotrophic factors that play an important role both in the central and peripheral nervous systems, where they modulate neuronal survival, development, function and plasticity. Brain-derived neurotrophic factor (BDNF) possesses diverse biological functions which are mediated by the activation of two main classes of receptors, the tropomyosin-related kinase (Trk) B and the p75 neurotrophin receptor (p75NTR). The therapeutic potential of BDNF has drawn attention since dysregulation of its signalling cascades has been suggested to underlie the pathogenesis of both common and rare diseases. Multiple strategies targeting this neurotrophin have been tested; most have found obstacles that ultimately hampered their effectiveness. This review focuses on the involvement of BDNF and its receptors in the pathophysiology of Alzheimer's disease (AD), Amyotrophic Lateral Sclerosis (ALS) and Rett Syndrome (RTT). We describe the known mechanisms leading to the impairment of BDNF/TrkB signalling in these disorders. Such mechanistic insight highlights how BDNF signalling compromise can take various shapes, nearly disease-specific. Therefore, BDNF-based therapeutic strategies must be specifically tailored and are more likely to succeed if a combination of resources is employed.
S327 phosphorylation of the presynaptic protein SEPTIN5 increases in the early stages of neurofibrillary pathology and alters the functionality of SEPTIN5
Publication . Ferreira, Catarina B.; Marttinen, Mikael; Coelho, Joana E; Paldanius, Kaisa M.A.; Takalo, Mari; Mäkinen, Petra; Leppänen, Luukas; Miranda-Lourenço, Catarina; Fonseca-Gomes, João; Tanqueiro, Sara; Vaz, Sandra H.; Belo, Rita F.; Sebastião, Ana M; Leinonen, Ville; Soininen, Hilkka; Pike, Ian; Haapasalo, Annakaisa; Lopes, Luisa V.; De Mendonça, Alexandre; Diógenes, Maria José; Hiltunen, Mikko
Alzheimer's disease (AD) is the most common form of dementia, which is neuropathologically characterized by extracellular senile plaques containing amyloid-β and intracellular neurofibrillary tangles composed of hyperphosphorylated tau protein. Previous studies have suggested a role for septin (SEPTIN) protein family members in AD-associated cellular processes. Here, we elucidated the potential role of presynaptic SEPTIN5 protein and its post-translational modifications in the molecular pathogenesis of AD. RNA and protein levels of SEPTIN5 showed a significant decrease in human temporal cortex in relation to the increasing degree of AD-related neurofibrillary pathology. Conversely, an increase in the phosphorylation of the functionally relevant SEPTIN5 phosphorylation site S327 was observed already in the early phases of AD-related neurofibrillary pathology, but not in the cerebrospinal fluid of individuals fulfilling the criteria for mild cognitive impairment due to AD. According to the mechanistic assessments, a link between SEPTIN5 S327 phosphorylation status and the effects of SEPTIN5 on amyloid precursor protein processing and markers of autophagy was discovered in mouse primary cortical neurons transduced with lentiviral constructs encoding wild type SEPTIN5 or SEPTIN5 phosphomutants (S327A and S327D). C57BL/6 J mice intrahippocampally injected with lentiviral wild type SEPTIN5 or phosphomutant constructs did not show changes in cognitive performance after five to six weeks from the start of injections. However, SEPTIN5 S327 phosphorylation status was linked to changes in short-term synaptic plasticity ex vivo at the CA3-CA1 synapse. Collectively, these data suggest that SEPTIN5 and its S327 phosphorylation status play a pivotal role in several cellular processes relevant for AD.
Microglial Sirtuin 2 shapes long-term potentiation in hippocampal slices
Publication . Sa de Almeida, Joana; Vargas, Mariana; Fonseca-Gomes, João; Tanqueiro, Sara; Belo, Rita F.; Miranda-Lourenço, Catarina; Sebastião, Ana M; Diógenes, Maria José; Pais, Teresa F.
Microglial cells have emerged as crucial players in synaptic plasticity during development and adulthood, and also in neurodegenerative and neuroinflammatory conditions. Here we found that decreased levels of Sirtuin 2 (Sirt2) deacetylase in microglia affects hippocampal synaptic plasticity under inflammatory conditions. The results show that long-term potentiation (LTP) magnitude recorded from hippocampal slices of wild type mice does not differ between those exposed to lipopolysaccharide (LPS), a pro-inflammatory stimulus, or BSA. However, LTP recorded from hippocampal slices of microglial-specific Sirt2 deficient (Sirt2-) mice was significantly impaired by LPS. Importantly, LTP values were restored by memantine, an antagonist of N-methyl-D-aspartate (NMDA) receptors. These results indicate that microglial Sirt2 prevents NMDA-mediated excitotoxicity in hippocampal slices in response to an inflammatory signal such as LPS. Overall, our data suggest a key-protective role for microglial Sirt2 in mnesic deficits associated with neuroinflammation.
Presynaptic vesicle protein SEPTIN5 regulates the degradation of APP C-Terminal fragments and the levels of Aβ
Publication . Marttinen, Mikael; Ferreira, Catarina B.; Paldanius, Kaisa M. A.; Takalo, Mari; Natunen, Teemu; Mäkinen, Petra; Leppänen, Luukas; Leinonen, Ville; Tanigaki, Kenji; Kang, Gina; Hiroi, Noboru; Soininen, Hilkka; Rilla, Kirsi; Haapasalo, Annakaisa; Hiltunen, Mikko
Alzheimer's disease (AD) is a neurodegenerative disease characterized by aberrant amyloid-β (Aβ) and hyperphosphorylated tau aggregation. We have previously investigated the involvement of SEPTIN family members in AD-related cellular processes and discovered a role for SEPTIN8 in the sorting and accumulation of β-secretase. Here, we elucidated the potential role of SEPTIN5, an interaction partner of SEPTIN8, in the cellular processes relevant for AD, including amyloid precursor protein (APP) processing and the generation of Aβ. The in vitro and in vivo studies both revealed that the downregulation of SEPTIN5 reduced the levels of APP C-terminal fragments (APP CTFs) and Aβ in neuronal cells and in the cortex of Septin5 knockout mice. Mechanistic elucidation revealed that the downregulation of SEPTIN5 increased the degradation of APP CTFs, without affecting the secretory pathway-related trafficking or the endocytosis of APP. Furthermore, we found that the APP CTFs were degraded, to a large extent, via the autophagosomal pathway and that the downregulation of SEPTIN5 enhanced autophagosomal activity in neuronal cells as indicated by altered levels of key autophagosomal markers. Collectively, our data suggest that the downregulation of SEPTIN5 increases the autophagy-mediated degradation of APP CTFs, leading to reduced levels of Aβ in neuronal cells.
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Fundação para a Ciência e a Tecnologia
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Funding Award Number
PD/BD/128091/2016
