Assessing real-time signaling and agonist-induced CRHR1 internalization by optical methods

CRHR1 endocytosis: Spatiotemporal regulation of receptor signaling

Corticotropin releasing hormone (CRH) is crucial for basal and stress-initiated reactions in the hypothalamic-pituitary-adrenal axis (HPA) and extrahypothalamic brain circuits, where it acts as a neuromodulator to organize behavioral and humoral responses to stress. We review and describe cellular components and molecular mechanisms involved in CRH system signaling through G protein-coupled receptors (GPCRs) CRHR1 and CRHR2, under the current view of GPCR signaling from the plasma membrane but also from intracellular compartments, which establish the bases of signal resolution in space and time. Focus is placed on latest studies of CRHR1 signaling in physiologically significant contexts of the neurohormone function that disclosed new mechanistic features of cAMP production and ERK1/2 activation. We also introduce in a brief overview the pathophysiological function of the CRH system, underlining the need for a complete characterization of CRHRs signaling to design new and specific therapies for stress-related disorders.

Stress-Related Brain Neuroinflammation Impact in Depression: Role of the Corticotropin-Releasing Hormone System and P2X7 Receptor

Depression and other psychiatric stress-related disorders are leading causes of disability worldwide. Up to date, treatments of mood disorders have limited success, most likely due to the multifactorial etiology of these conditions. Alterations in inflammatory processes have been identified as possible pathophysiological mechanisms in psychiatric conditions. Here, we review the main features of 2 systems involved in the control of these inflammatory pathways: the CRH system as a key regulator of the stress response and the ATP-gated ion-channel P2X7 receptor (P2X7R) involved in the control of immune functions. The pathophysiology of depression as a stress-related psychiatric disorder is depicted in terms of the impact of CRH and P2X7R function on inflammatory pathways in the brain. Understanding pathogenesis of affective disorders will lead to the development of therapies for treatment of depression and other stress-related diseases.