Il-6 Modulates CRF in the Hypothalamus in Response to Different Signals.

Module: 5/22/2010

Background: CRF can regulate signaling in response to different odors. In those cases, it can lead to an anxiolytic or elevation and other responses typical of the stress response including pain generation, immune regulation, itch, rash and other changes such as gastric function alterations. Of course, these are symptoms characteristic of chemical sensitivity and also some symptoms characteristic of other environmentally influenced conditions such as CFS and sickness syndrome.

A major regulator of sickness syndrome is Il-6 which can be functionally modulated through Il-10 and ultimately most probably HO-1 which has been shown in other studies to increase during exercise. Interestingly, one can identify similarities in cancer-related fatigue to some chronic symptoms of CFS and sickness syndrome including the exhausting fatigue and cachexia that is exhibited in the latter, in animals and humans. Preliminary studies suggest cytokine Il-6/Il-8 may modulate the severity of cancer-related fatigue and others show cancer-related fatigue is common with serotonin dysregulation. Coincidentally, in the trout corticotrophin activation by ammonia is associated with alterations in neurotransmitter levels including dopamine and serotonin. So here again, we see potential especially with periods of aberrant corticotrophin signalling, where symptoms of environmental illness such as anxiety, depression, weakeness and fatigue may present itself. These findings supports past studies that suggest that fatigue in CFS may be in part due to serotonin dysregulation and elevations in Il-6.(Ryan)

CiteULike: Transcriptional regulation of hypothalamic corticotropin-releasing factor gene.: "Glucocorticoid-dependent repression of cAMP-stimulated CRF promoter activity is mediated by both nGRE and SRE in hypothalamic cells. Interleukin (IL)-6 produced in the hypothalamus stimulates the CRF gene. Suppressor of cytokine signaling-3, which is induced by a cAMP stimulant and IL-6, is involved in the negative regulation of CRF gene expression in hypothalamic cells. Such complex mechanisms would contribute to stress responses and homeostasis in the hypothalamus."

Related: Hummel, M., Cummons, T., Lu, P., Mark, L., Harrison, J. E., Kennedy, J. D., and Whiteside, G. T. (2010). Pain is a salient ßtressor" that is mediated by corticotropin- releasing factor-1 receptors. Neuropharmacology.
http://www.citeulike.org/user/HEIRS/article/7177466
Coric, V., Feldman, H. H., Oren, D. A., Shekhar, A., Pultz, J., Dockens, R. C., Wu, X., Gentile, K. A., Huang, S.-P. P., Emison, E., Delmonte, T., D'Souza, B. B., Zimbroff, D. L., Grebb, J. A., Goddard, A. W., and Stock, E. G. (2010). Multicenter, randomized, double-blind, active comparator and placebo-controlled trial of a corticotropin-releasing factor receptor-1 antagonist in generalized anxiety disorder. Depression and anxiety, 27(5):417-425.
http://www.citeulike.org/user/HEIRS/article/7193107
Theoharides, T. C., Singh, Boucher, W., Pang, X., Letourneau, R., Webster, E., and Chrousos, G. (1998). Corticotropin-releasing hormone induces skin mast cell degranulation and increased vascular permeability, a possible explanation for its proinflammatory effects. Endocrinology, 139(1):403-413.
http://www.citeulike.org/user/HEIRS/article/7207688
Mustian, K. M., Fisher, S., Adams, J., Janelsins, M., Palesh, O., Darling, T., Peppone, L., Heckler, C., Williams, J., and Morrow, G. (2009). Cytokine-mediated changes associated with improvements in cancer-related fatigue induced by exercise: Results from a randomized pilot study of cancer patients receiving radiotherapy. Journal of Clinical Oncology, 27(15s).
http://www.citeulike.org/user/HEIRS/article/7207720
Ryan, J. L., Carroll, J. K., Ryan, E. P., Mustian, K. M., Fiscell, K., and Morrow, G. R. (2007). Mechanisms of cancer-related fatigue. The Oncologist, 12(1 supp):22-34.
http://www.citeulike.org/user/HEIRS/article/7207823