1
views
0
recommends
+1 Recommend
1 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found

      IL-6 and Its Circadian Secretion in Humans

      Read this article at

      ScienceOpenPublisherPubMed
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Interleukin-6 (IL-6) is a pleiotropic cytokine produced by numerous types of immune and nonimmune cells and is involved in many pathophysiologic mechanisms in humans. Many studies suggest that IL-6 is a putative ‘sleep factor’ and its circadian secretion correlates with sleep/sleepiness. IL-6 is elevated in disorders of excessive daytime sleepiness such as narcolepsy and obstructive sleep apnea. It correlates positively with body mass index and may be a mediator of sleepiness in obesity. Also the secretion of this cytokine is stimulated by total acute or partial short-term sleep loss reflecting the increased sleepiness experienced by sleep-deprived individuals. Studies that evaluated the 24-hour secretory pattern of IL-6 in healthy young adults suggest that IL-6 is secreted in a biphasic circadian pattern with two nadirs at about 08.00 and 21.00, and two zeniths at about 19.00 and 05.00 h. In contrast, following sleep deprivation or in disorders of sleep disturbance, e.g., insomnia, IL-6 peaks during the day and, based on the level of stress system activity, i.e., cortisol secretion, contributes to either sleepiness and deep sleep (low cortisol) or feelings of tiredness and fatigue and poor sleep (high cortisol). In order to address concerns about the potential impact of differences of IL-6 levels between the beginning and the end of the 24-hour blood-drawing experiment, we proceeded with a cosinor analysis of ‘detrended’ data in young and old healthy individuals. This new analysis did not affect the biphasic circadian pattern of IL-6 secretion in young adults, while it augmented the flattened circadian pattern in old individuals in whom the difference was greater. Finally, IL-6 appears to be somnogenic in rats and exhibits a diurnal rhythm that follows the sleep/wake cycle in these animals. We conclude that IL-6 is a mediator of sleepiness and its circadian pattern reflects the homeostatic drive for sleep.

          Related collections

          Most cited references 27

          • Record: found
          • Abstract: found
          • Article: not found

          Bone marrow, cytokines, and bone remodeling. Emerging insights into the pathophysiology of osteoporosis.

          Both osteoblasts and osteoclasts are derived from progenitors that reside in the bone marrow; osteoblasts belong to the mesenchymal lineage of the marrow stroma, and osteoclasts to the hematopoietic lineage. The development of osteoclasts from their progenitors is dependent on stromal-osteoblastic cells, which are a major source of cytokines that are critical in osteoclastogenesis, such as interleukin-6 and interleukin-11. The production of interleukin-6 by stromal osteoblastic cells, as well as the responsiveness of bone marrow cells to cytokines such as interleukin-6 and interleukin-11, is regulated by sex steroids. When gonadal function is lost, the formation of osteoclasts as well as osteoblasts increases in the marrow, both changes apparently mediated by an increase in the production of interleukin-6 and perhaps by an increase in the responsiveness of bone marrow progenitor cells not only to interleukin-6 but also to other cytokines with osteoclastogenic and osteoblastogenic properties. The cellular activity of the bone marrow is also altered by the process of aging. Specifically, senescence may decrease the ability of the marrow to form osteoblast precursors. The association between the dysregulation of osteoclast or osteoblast development in the marrow and the disruption of the balance between bone resorption and bone formation, resulting in the loss of bone, leads to the following notion. Like homeostasis of other regenerating tissues, homeostasis of bone depends on the orderly replenishment of its cellular constituents. Excessive osteoclastogenesis and inadequate osteoblastogenesis are responsible for the mismatch between the formation and resorption of bone in postmenopausal and age-related osteopenia. The recognition that changes in the numbers of bone cells, rather than changes in the activity of individual cells, form the pathogenetic basis of osteoporosis is a major advance in understanding the mechanism of this disease.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Adverse effects of modest sleep restriction on sleepiness, performance, and inflammatory cytokines.

            Total sleep restriction in humans is associated with increased daytime sleepiness, decreased performance, and hormonal/metabolic disturbances. The effects of mild chronic sleep restriction that mimic real life are not known. To assess the effects of modest sleep restriction from 8 to 6 h/night for 1 wk, 25 young, healthy, normal sleepers (12 men and 13 women) were studied for 12 consecutive nights in the sleep laboratory. After 1 wk of sleep restriction, although subjects' nighttime sleep was deeper, subjects were significantly sleepier (multiple sleep latency test) and performed worse in four primary variables of psychomotor vigilance test (both P < 0.01). Furthermore, 24-h secretion of IL-6 was increased by 0.8 +/- 0.3 pg/ml (P < 0.05) in both sexes, whereas TNFalpha was increased only in men. Also, the peak cortisol secretion was lower after sleep restriction than at baseline, and this difference was stronger in men (55.18 +/- 24.83 nmol/liter; P < 0.05) than in women (35.87 +/- 24.83 nmol/liter; P < 0.16). We conclude that in young men and women, modest sleep loss is associated with significant sleepiness, impairment of psychomotor performance, and increased secretion of proinflammatory cytokines. Given the potential association of these behavioral and physical alterations with health, well-being, and public safety, the idea that sleep or parts of it are optional should be regarded with caution.
              Bookmark
              • Record: found
              • Abstract: not found
              • Article: not found

              Subcutaneous Adipose Tissue Releases Interleukin-6, But Not Tumor Necrosis Factor- , in Vivo

               V Mohamed-Ali (1997)
                Bookmark

                Author and article information

                Journal
                NIM
                Neuroimmunomodulation
                10.1159/issn.1021-7401
                Neuroimmunomodulation
                S. Karger AG
                1021-7401
                1423-0216
                2005
                May 2005
                17 May 2005
                : 12
                : 3
                : 131-140
                Affiliations
                aSleep Research and Treatment Center, Department of Psychiatry and bHealth Evaluation Sciences, Penn State College of Medicine, Hershey, Pa., cDepartment of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, Calif., and dPediatric and Reproductive Endocrinology Branch, National Institutes of Health, Bethesda, Md., USA
                Article
                84844 Neuroimmunomodulation 2005;12:131–140
                10.1159/000084844
                15905620
                © 2005 S. Karger AG, Basel

                Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher. Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug. Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.

                Page count
                Figures: 8, References: 46, Pages: 10
                Categories
                Original Paper

                Comments

                Comment on this article