Aging is a normal physiological process accompanied by cognitive decline. This aging process has been the primary risk factor for development of aging-related diseases such as Alzheimer's disease (AD). Cognitive deficit is related to alterations of neurotrophic factors level such as brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF) and glial cellderived neurotrophic factor (GDNF). These strong relationship between aging and AD is important to investigate the time which they overlap, as well as, the pathophysiological mechanism in each event. Considering that aging and AD are related to cognitive impairment, here we discuss the involving these neurotrophic factors in the aging process and AD.

No abstract

Alzheimer's disease (AD) is a neurodegenerative disorder where the main risk factor is age, since its incidence increases dramatically after the age of 60. It is the most common form of dementia, and is accompanied by memory loss and cognitive impairment. Although AD was discovered over a century ago, the only drugs approved by the US Food and Drug Administration for use in its treatment are four cholinesterase inhibitors and memantine. However, these drugs are not fully effective in the treatment of AD. Therefore, the incessant search for new methods of treating AD continues, with the hope of improving both the effectiveness of therapies and the quality of life for patients suffering with AD. Current evidence suggests that the antibiotic minocycline could be a potential therapeutic drug for use in the treatment of AD due to its anti-neuroinflammatory effects. Minocycline is a tetracycline derivative that combines an anti-inflammatory property that is capable of crossing the blood brain barrier with neuroprotective properties that work by limiting inflammation and oxidative stress. Several studies have established the presence of inflammatory markers in the brains of patients suffering with AD, including elevated levels of cytokines/chemokines and microgliosis in damaged regions. Cytokines have been associated with increased tau phosphorylation and decreased levels of synaptophysin, establishing their roles in the cytoskeletal and synaptic alterations that take place in AD. Therefore, pharmacological approaches that allow for the discovery and development of new anti-inflammatory agents such as minocycline will be welcomed in the continuing struggle against AD. Considering these facts, this review will discuss the anti-inflammatory mechanisms underlying the neuroprotective effects of minocycline as a novel therapeutic approach for the treatment of AD.

Sepsis is defined as the host's reaction to infection and characterised by a systemic inflammatory response with important clinical implications. Central nervous system dysfunction secondary to sepsis is associated with local generation of pro- and anti-inflammatory cytokines, impaired cerebral microcirculation, an imbalance of neurotransmitters, apoptosis and cognitive impairment. It's known that the IL-1β is one of the first cytokines to be altered. Thus, the objective of this study was to evaluate the role of IL-1β in cognitive parameters in brain tissue through the use of an IL-1β (IL-1ra) receptor antagonist up to 10 days and to assess blood-brain barrier permeability, cytokine levels, oxidative parameters and energetic metabolism up to 24 h, after sepsis induction. To this aim, we used sham-operated Wistar rats or submitted to the cecal ligation and perforation (CLP) procedure. Immediately after, the animals received one dose of 10 μg of IL-1ra. After 24 h, the rats were killed and were evaluated for biochemical parameters in the pre-frontal cortex, hippocampus and striatum. After 10 days, the animals were submitted to the habituation to the open field and step-down inhibitory avoidance task. We observed that the use of IL-1ra reverted the increase of blood-brain barrier permeability in the pre-frontal cortex, hippocampus and striatum; the increase of IL-1β, IL1-6 and TNF-α levels in the pre-frontal cortex and striatum; the decrease of complex I activity in the pre-frontal, hippocampus and striatum; the increase of oxidative parameters in pre-frontal cortex, hippocampus and striatum; and cognitive impairment. In conclusion, the results observed in this study reinforce the role of acute brain inflammatory response, in particular, the IL1β response, in the cognitive impairment associated with sepsis.

No abstract