Stress exposure, whether acute or chronic, is now recognized to be a determinant of epileptogenic vulnerability. Psychological stress or trauma may not only precipitate seizures but also actively cont Show more
Stress exposure, whether acute or chronic, is now recognized to be a determinant of epileptogenic vulnerability. Psychological stress or trauma may not only precipitate seizures but also actively contribute to the development of epilepsy, a concept that in the clinical setting could be termed "psychoepileptogenesis". Recent evidence from both animal models and clinical studies supports the role of emotional stress in facilitating epileptogenesis, particularly within limbic structures such as the amygdala and hippocampus. In rodent models, chronic stress has been shown to lower seizure thresholds and promote epileptogenesis through mechanisms involving brain-derived neurotrophic factor (BDNF) and dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis. Human studies reinforce these findings: individuals exposed to trauma or suffering from post-traumatic stress disorder (PTSD) exhibit an elevated risk of developing epilepsy, especially temporal lobe epilepsy (TLE), with structural and functional neuroimaging revealing changes in limbic and paralimbic circuits. These converging lines of evidence suggest that psychoepileptogenesis is a plausible, albeit complex, phenomenon. Further research is needed to identify biomarkers of vulnerability and evaluate whether early interventions targeting stress pathways might alter the course of epileptogenesis. Show less
The extracellular matrix (ECM) is essential to provide mechanical support to tissues but is also a bioactive edifice which controls cell behavior. Cell signaling generated by ECM components through in Show more
The extracellular matrix (ECM) is essential to provide mechanical support to tissues but is also a bioactive edifice which controls cell behavior. Cell signaling generated by ECM components through integrin-mediated contacts, modulates cell biological activity. In addition, by sequestrating or releasing growth factors, the ECM is an active player of physiological and pathological processes such as vascular development. EGFL7 is mainly expressed during blood vessel development and is deposited in the ECM after secretion by endothelial cells. While EGFL7 is known to control various endothelial cell molecular mechanisms [i.e., the repression of endothelial-derived lysyl oxidase (LOX) enzyme, the regulation of the Notch pathway, and the expression of leukocyte adhesion molecules and of RHOA by endothelial cells], it is not established whether EGFL7 functions when bound to the ECM. Here, we show that microfibrillar-associated glycoprotein-1 (MAGP-1) and fibronectin drive the deposition of EGFL7 into both fibers and individual aggregates in endothelial ECM. Although EGFL7 does not need to be docked into the ECM to control endothelial adhesion molecule expression, the ECM accumulation of EGFL7 is required for its regulation of LOX activity and of HEY2 expression along the Notch pathway. The interaction of EGFL7 with MAGP-1 is necessary for LOX activity repression by EGFL7 while it does not participate in the control of the Notch pathway by this protein. Altogether, this study highlights the roles played by EGFL7 in controlling various endothelial molecular mechanisms upon its localization and shows how the ECM can modulate its functions. Show less