Aims: Psychosocial stress alters the hypothalamic-pituitary-adrenal axis (HPA-axis). Increasing evidence shows a link between these alterations and oxidant elevation. Oxidative stress is implicated in the stress response and in the pathogenesis of neurologic and psychiatric diseases. NADPH oxidases (NOXs) are a major source of reactive oxygen species (ROS) in the central nervous system. Here, we investigated the contributory role of NOX2-derived ROS to the development of neuroendocrine alterations in a rat model of chronic psychosocial stress, the social isolation. Results: Significant elevations in the hypothalamic levels of corticotropin-releasing factor and plasmatic adrenocorticotropic hormone were observed from 4 weeks of social isolation. Increased levels of peripheral markers of the HPA-axis (plasmatic and salivary corticosterone) were observed at a later time point of social isolation (7 weeks). Alteration in the exploratory activity of isolated rats followed the same time course. Increased expression of markers of oxidative stress (8-hydroxy-2-deoxyguanosine [8OhdG] and nitrotyrosine) and NOX2 mRNA was early detectable in the hypothalamus of isolated rats (after 2 weeks), but later (after 7 weeks) in the adrenal gland. A 3-week treatment with the antioxidant/NOX inhibitor apocynin stopped the progression of isolation-induced alterations of the HPA-axis. Rats with a loss-of-function mutation in the NOX2 subunit p47(phox) were totally protected from the alterations of the neuroendocrine profile, behavior, and increased NOX2 mRNA expression induced by social isolation. Innovation: We demonstrate that psychosocial stress induces early elevation of NOX2-derived oxidative stress in the hypothalamus and consequent alterations of the HPA-axis, leading ultimately to an altered behavior. Conclusion: Pharmacological targeting of NOX2 might be of crucial importance for the treatment of psychosocial stress-induced psychosis. Antioxid. Redox Signal. 18, 1385-1399.
Neuroendocrine Profile in a Rat Model of Psychosocial Stress: Relation to Oxidative Stress / Marilena, Colaianna; Schiavone, Stefania; Margherita, Zotti; Tucci, Paolo; Maria Grazia, Morgese; Liselotte, Backdahl; Rikard, Holmdahl; Karl Heinz, Krause; Cuomo, Vincenzo; Luigia, Trabace. - In: ANTIOXIDANTS & REDOX SIGNALING. - ISSN 1523-0864. - 18:12(2013), pp. 1385-1399. [10.1089/ars.2012.4569]
Neuroendocrine Profile in a Rat Model of Psychosocial Stress: Relation to Oxidative Stress
SCHIAVONE, STEFANIA;TUCCI, Paolo;CUOMO, VINCENZO;
2013
Abstract
Aims: Psychosocial stress alters the hypothalamic-pituitary-adrenal axis (HPA-axis). Increasing evidence shows a link between these alterations and oxidant elevation. Oxidative stress is implicated in the stress response and in the pathogenesis of neurologic and psychiatric diseases. NADPH oxidases (NOXs) are a major source of reactive oxygen species (ROS) in the central nervous system. Here, we investigated the contributory role of NOX2-derived ROS to the development of neuroendocrine alterations in a rat model of chronic psychosocial stress, the social isolation. Results: Significant elevations in the hypothalamic levels of corticotropin-releasing factor and plasmatic adrenocorticotropic hormone were observed from 4 weeks of social isolation. Increased levels of peripheral markers of the HPA-axis (plasmatic and salivary corticosterone) were observed at a later time point of social isolation (7 weeks). Alteration in the exploratory activity of isolated rats followed the same time course. Increased expression of markers of oxidative stress (8-hydroxy-2-deoxyguanosine [8OhdG] and nitrotyrosine) and NOX2 mRNA was early detectable in the hypothalamus of isolated rats (after 2 weeks), but later (after 7 weeks) in the adrenal gland. A 3-week treatment with the antioxidant/NOX inhibitor apocynin stopped the progression of isolation-induced alterations of the HPA-axis. Rats with a loss-of-function mutation in the NOX2 subunit p47(phox) were totally protected from the alterations of the neuroendocrine profile, behavior, and increased NOX2 mRNA expression induced by social isolation. Innovation: We demonstrate that psychosocial stress induces early elevation of NOX2-derived oxidative stress in the hypothalamus and consequent alterations of the HPA-axis, leading ultimately to an altered behavior. Conclusion: Pharmacological targeting of NOX2 might be of crucial importance for the treatment of psychosocial stress-induced psychosis. Antioxid. Redox Signal. 18, 1385-1399.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
