Júlia Senserrich

Major depressive disorder (MDD) is a complex neuropsychiatric disorder affected by genetic and environmental factors and associated with inflammation and impaired neuroplasticity. This study investigated the role of matrix metalloproteinase-9 (MMP-9), inflammatory markers (STAT3 and NF-κB), and the neuroplasticity marker BDNF in the prefrontal cortex of subjects with MDD and their matched controls. The results showed increased MMP-9 expression and activity in MDD, particularly in those without detectable antidepressant treatment and in subjects who died by suicide. The association with suicide was especially pronounced in women, suggesting sex-dependent differences. Regarding inflammation, untreated subjects showed higher STAT3 and NF-κB levels, while antidepressant-treated subjects showed reduced STAT3 levels, particularly men, suggesting a possible anti-inflammatory effect of antidepressants. In addition, treated men showed higher BDNF levels, which may reflect enhanced neuroplasticity. Overall, this study suggests that MMP-9 may be a potential marker of depression severity and suicidal behavior, especially in women, while neuroinflammation may play a more prominent role in men. These findings further highlight the importance of considering sex differences when investigating the role of MMP-9 in the pathophysiology of MDD.

The increase in antioxidant defenses mediated by physical exercise signaling is proposed to be a protective factor against brain aging and neurodegeneration. However, the processes involved, particularly the response of senescence markers and cell fitness status in the context of Alzheimer’s disease (AD) pathology, remain unclear. We analyzed male and female 5XFAD transgenic AD mice subjected to 6 months of voluntary wheel running using molecular and behavioral techniques. Levels of mRNA of selected genes, mitochondrial complex proteins, and proteasomal function, were analyzed in the cerebral cortex or hippocampus. In an exploratory translational approach, proteasomal dynamics- and senescence-related genes were analyzed in peripheral blood from middle-aged amateur sportsmen. Physical exercise increased expression of antioxidant genes and modulated epigenetic genes in 5XFAD male and female mice. An increase in protein levels of hippocampal mitochondrial complexes CIII and CV was also induced in males. Both exercised 5XFAD mice and veteran sportsmen showed improved proteasomal status and decreased expression of senescence genes. Exercised mice showed memory and behavior preservation, as well as increases in brain metabolic fitness and gene modulation. These changes may contribute to the neuroprotective effect of physical exercise.

Depression is the most prevalent of the mental illnesses and serotonin (5-hydroxytryptamine, 5-HT) is considered to be the major neurotransmitter involved in its etiology and treatment. In this context, 5-HT_1A receptors have attracted interest as targets for therapeutic intervention. Notably the activation of presynaptic 5-HT_1A autoreceptors delays antidepressant effects whereas the stimulation of postsynaptic 5-HT_1A heteroreceptors is needed for an antidepressant action. NLX-101 (also known as F15599) is a selective biased agonist which exhibits preferred activation of cortical over brain stem 5-HT_1A receptors. Here, we used behavioral, neurochemical and molecular methods to examine the antidepressant-like effects in rats of a single dose of NLX-101 (0.16 mg/kg, i.p.). NLX-101 reduced immobility in the forced swim test when measured 30 min but not 24 h after drug administration. NLX-101 increased extracellular concentrations of glutamate and dopamine in the medial prefrontal cortex, but no changes were detected in the efflux of noradrenaline or 5-HT. NLX-101 also produced an increase in the activation of pmTOR, pERK1/2 and pAkt, and the expression of PSD95 and GluA1, which may contribute to its rapid antidepressant action.

Oxidative damage is involved in the pathophysiology of age-related ailments, including Alzheimer’s disease (AD). Studies have shown that the brain tissue and also lymphocytes from AD patients present increased oxidative stress compared to healthy controls (HCs). Here, we use lymphoblastoid cell lines (LCLs) from AD patients and HCs to investigate the role of resveratrol (RV) and selenium (Se) in the reduction of reactive oxygen species (ROS) generated after an oxidative injury. We also studied whether these compounds elicited expression changes in genes involved in the antioxidant cell response and other aging-related mechanisms. AD LCLs showed higher ROS levels than those from HCs in response to H₂O₂ and FeSO₄ oxidative insults. RV triggered a protective response against ROS under control and oxidizing conditions, whereas Se exerted antioxidant effects only in AD LCLs under oxidizing conditions. RV increased the expression of genes encoding known antioxidants (catalase, copper chaperone for superoxide dismutase 1, glutathione S-transferase zeta 1) and anti-aging factors (sirtuin 1 and sirtuin 3) in both AD and HC LCLs. Our findings support RV as a candidate for inducing resilience and protection against AD, and reinforce the value of LCLs as a feasible peripheral cell model for understanding the protective mechanisms of nutraceuticals against oxidative stress in aging and AD.