Person: Pelayo Alarcón, Adela
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First Name
Adela
Last Name
Pelayo Alarcón
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Medicina
Department
Medicina Legal, Psiquiatría y Patología
Area
Anatomía Patológica
Identifiers
5 results
Search Results
Now showing 1 - 5 of 5
Item Primary hippocampal neuronal cell death induction after acute and repeated paraquat exposures mediated by AChE variants alteration and cholinergic and glutamatergic transmission disruption(Toxicology, 2017) Pino Sans, Javier Del; Moyano-Cires Ivanoff, Paula Viviana; Gómez Díaz, Gloria; Anadón Baselga, María José; Díaz Plaza, María Jesús; García Sánchez, José Manuel; Lobo Alonso, Margarita; Pelayo Alarcón, Adela; Sola Vendrell, Emma; Frejo Moya, María TeresaParaquat (PQ) is a widely used non-selective contact herbicide shown to produce memory and learning deficits after acute and repeated exposure similar to those induced in Alzheimer's disease (AD). However, the complete mechanisms through which it induces these effects are unknown. On the other hand, cholinergic and glutamatergic systems, mainly in the hippocampus, are involved on learning, memory and cell viability regulation. An alteration of hippocampal cholinergic or glutamatergic transmissions or neuronal cell loss may induce these effects. In this regard, it has been suggested that PQ may induce cell death and affect cholinergic and glutamatergic transmission, which alteration could produce neuronal loss. According to these data, we hypothesized that PQ could induce hippocampal neuronal loss through cholinergic and glutamatergic transmissions alteration. To prove this hypothesis, we evaluated in hippocampal primary cell culture, the PQ toxic effects after 24h and 14 consecutive days exposure on neuronal viability and the cholinergic and glutamatergic mechanisms related to it. This study shows that PQ impaired acetylcholine levels and induced AChE inhibition and increased CHT expression only after 14days exposure, which suggests that acetylcholine levels alteration could be mediated by these actions. PQ also disrupted glutamate levels through induction of glutaminase activity. In addition, PQ induced, after 24h and 14days exposure, cell death on hippocampal neurons that was partially mediated by AChE variants alteration and cholinergic and gultamatergic transmissions disruption. Our present results provide new view of the mechanisms contributing to PQ neurotoxicity and may explain cognitive dysfunctions observed after PQ exposure.Item Cadmium alters heat shock protein pathways in SN56 cholinergic neurons, leading to AB and phosphorylated Tau protein generation and cell death(Food and Chemical Toxicology, 2018) Moyano-Cires Ivanoff, Paula Viviana; García Sánchez, José Manuel; Lobo Alonso, Margarita; Anadón Baselga, María José; Sola Vendrell, Emma; Pelayo Alarcón, Adela; García Lobo, Jimena; Frejo Moya, María Teresa; Pino Sans, Javier DelCadmium, a neurotoxic environmental compound, produces cognitive disorders, although the mechanism remains unknown. Cadmium induces a more pronounced cell death on cholinergic neurons from basal forebrain (BF), mediated, in part, by increase in Aβ and total and phosphorylated Tau protein levels, which may explain cadmium effects on learning and memory processes. Cadmium downregulates the expression of heat shock proteins (HSPs) HSP 90, HSP70 and HSP27, and of HSF1, the master regulator of the HSP pathway. HSPs proteins reduce the production of Aβ and phosphorylated Tau proteins and avoid cell death pathways induction. Thus, we hypothesized that cadmium induced the production of Aβ and Tau proteins by HSP pathway disruption through HSF1 expression alteration, leading to BF cholinergic neurons cell death. Our results show that cadmium downregulates HSF1, leading to HSP90, HSP70 and HSP27 gene expression downregulation in BF SN56 cholinergic neurons. In addition, cadmium induced Aβ and total and phosphorylated Tau proteins generation, mediated partially by HSP90, HSP70 and HSP27 disruption, leading to cell death. These results provide new understanding of the mechanisms contributing to cadmium harmful effects on cholinergic neurons.Item Manganese induced ROS and AChE variants alteration leads to SN56 basal forebrain cholinergic neuronal loss after acute and long-term treatment(Food and Chemical Toxicology, 2019) Moyano-Cires Ivanoff, Paula Viviana; García Sánchez, José Manuel; Anadón Baselga, María José; Lobo Alonso, Margarita; García Lobo, Jimena; Frejo Moya, María Teresa; Sola Vendrell, Emma; Pelayo Alarcón, Adela; Pino Sans, Javier DelManganese (Mn) induces cognitive disorders and basal forebrain (BF) cholinergic neuronal loss, involved on learning and memory regulation, which could be the cause of such cognitive disorders. However, the mechanisms through which it induces these effects are unknown. We hypothesized that Mn could induce BF cholinergic neuronal loss through oxidative stress generation, cholinergic transmission and AChE variants alteration that could explain Mn cognitive disorders. This study shows that Mn impaired cholinergic transmission in SN56 cholinergic neurons from BF through alteration of AChE and ChAT activity and CHT expression. Moreover, Mn induces, after acute and long-term exposure, AChE variants alteration and oxidative stress generation that leaded to lipid peroxidation and protein oxidation. Finally, Mn induces cell death on SN56 cholinergic neurons and this effect is independent of cholinergic transmission alteration, but was mediated partially by oxidative stress generation and AChE variants alteration. Our results provide new understanding of the mechanisms contributing to the harmful effects of Mn on cholinergic neurons and their possible involvement in cognitive disorders induced by Mn.Item Manganese increases Aβ and Tau protein levels through proteasome 20S and heat shock proteins 90 and 70 alteration, leading to SN56 cholinergic cell death following single and repeated treatment(Ecotoxicology and Environmental Safety, 2020) Moyano-Cires Ivanoff, Paula Viviana; García Sánchez, José Manuel; García Lobo, Jimena; Anadón Baselga, María José; Naval López, María Victoria; Frejo Moya, María Teresa; Sola Vendrell, Emma; Pelayo Alarcón, Adela; Pino Sans, Javier DelManganese (Mn) produces cholinergic neuronal loss in basal forebrain (BF) region that was related to cognitive dysfunction induced after single and repeated Mn treatment. All processes that generate cholinergic neuronal loss in BF remain to be understood. Mn exposure may produce the reduction of BF cholinergic neurons by increasing amyloid beta (Aβ) and phosphorylated Tau (pTau) protein levels, altering heat shock proteins’ (HSPs) expression, disrupting proteasome P20S activity and generating oxidative stress. These mechanisms, described to be altered by Mn in regions different than BF, could lead to the memory and learning process alteration produced after Mn exposure. The research performed shows that single and repeated Mn treatment of SN56 cholinergic neurons from BF induces P20S inhibition, increases Aβ and pTau protein levels, produces HSP90 and HSP70 proteins expression alteration, and oxidative stress generation, being the last two effects mediated by NRF2 pathway alteration. The increment of Aβ and pTau protein levels was mediated by HSPs and proteasome dysfunction. All these mechanisms mediated the cell decline observed after Mn treatment. Our results are relevant because they may assist to reveal the processes leading to the neurotoxicity and cognitive alterations observed after Mn exposure.Item Cadmium induced ROS alters M1 and M3 receptors, leading to SN56 cholinergic neuronal loss, through AChE variants disruption(Toxicology, 2018) Moyano-Cires Ivanoff, Paula Viviana; De Frias, Mariano; Lobo Alonso, Margarita; Anadón Baselga, María José; Sola Vendrell, Emma; Pelayo Alarcón, Adela; Díaz Plaza, María Jesús; Frejo Moya, María Teresa; Pino Sans, Javier DelCadmium, an environmental neurotoxic compound, produces cognitive disorders, although the mechanism remains unknown. Previously, we described that cadmium induces a more pronounced cell death on cholinergic neurons from basal forebrain (BF). This effect, partially mediated by M1 receptor blockade, triggering it through AChE splices variants alteration, may explain cadmium effects on learning and memory processes. Cadmium has been also reported to induce oxidative stress generation leading to M2 and M4 muscarinic receptors alteration, in hippocampus and frontal cortex, which are necessary to maintain cell viability and cognitive regulation, so their alteration in BF could also mediate this effect. Moreover, it has been reported that antioxidant treatment could reverse cognitive disorders, muscarinic receptor and AChE variants alterations induced by cadmium. Thus, we hypothesized that cadmium induced cell death of BF cholinergic neurons is mediated by oxidative stress generation and this mechanism could produce this effect, in part, through AChE variants altered by muscarinic receptors disruption. To prove this, we evaluated in BF SN56 cholinergic neurons, whether cadmium induces oxidative stress and alters muscarinic receptors, and their involvement in the induction of cell death through alteration of AChE variants. Our results show that cadmium induces oxidative stress, which mediates partially the alteration of AChE variants and M2 to M4 muscarinic receptors expression and blockage of M1 receptor. In addition, cadmium induced oxidative stress generation by M1 and M3 receptors alteration through AChE variants disruption, leading to cell death. These results provide new understanding of the mechanisms contributing to cadmium harmful effects on cholinergic neurons.