La depresión como factor de riesgo de la demencia: fisiopatología y modelos preclínicos de estudio / Depression as a risk factor for dementia: Pathophysiology and preclinical study models

El aumento de la esperanza de vida ha llevado a un incremento en la incidencia de enfermedades crónicas como la demencia. Tratar los factores de riesgo de la demencia, como la depresión, podría reducir su incidencia. Sin embargo, el tratamiento con antidepresivos no ha sido eficaz en el manejo de este síntoma, lo que aumenta el riesgo de demencia en el futuro. Es fundamental investigar las causas y el tratamiento de la depresión, y el uso de modelos animales es importante en este sentido. Este estudio busca analizar la relación entre la depresión y el riesgo de desarrollar demencia, así como los modelos preclínicos más relevantes para estudiar la depresión en roedores. (AU)

The increase in life expectancy has led to a rise in the incidence of chronic diseases, such as dementia. Treating the risk factors of dementia, such as depression, could help reduce its occurrence. However, antidepressant treatment has not proven effective in managing this symptom, thereby increasing the risk of dementia in the future. It is essential to investigate the causes and treatment of depression, and in this regard, the use of animal models is of great significance. This study aims to analyze the evidence supporting the relationship between depression and the risk of developing dementia, while also providing an update on the most relevant preclinical models for studying depression in rodents. (AU)

JM-20 treatment prevents neuronal damage and memory impairment induced by aluminum chloride in rats.

The number of people with dementia worldwide is estimated at 50 million by 2018 and continues to rise mainly due to increasing aging and population growth. Clinical impact of current interventions remains modest and all efforts aimed at the identification of new therapeutic approaches are therefore critical. Previously, we showed that JM-20, a dihydropyridine-benzodiazepine hybrid molecule, protected memory processes against scopolamine-induced cholinergic dysfunction. In order to gain further insight into the therapeutic potential of JM-20 on cognitive decline and Alzheimer's disease (AD) pathology, here we evaluated its neuroprotective effects after chronic aluminum chloride (AlCl3) administration to rats and assessed possible alterations in several types of episodic memory and associated pathological mechanisms. Oral administration of aluminum to rodents recapitulates several neuropathological alterations and cognitive impairment, being considered a convenient tool for testing the efficacy of new therapies for dementia. We used behavioral tasks to test spatial, emotional- associative and novel object recognition memory, as well as molecular, enzymatic and histological assays to evaluate selected biochemical parameters. Our study revealed that JM-20 prevented memory decline alongside the inhibition of AlCl3 -induced oxidative stress, increased AChE activity, TNF-α and pro-apoptotic proteins (like Bax, caspase-3, and 8) levels. JM-20 also protected against neuronal damage in the hippocampus and prefrontal cortex. Our findings expanded our understanding of the ability of JM-20 to preserve memory in rats under neurotoxic conditions and confirm its potential capacity to counteract cognitive impairment and etiological factors of AD by breaking the progression of key steps associated with neurodegeneration.