TITLE

The roles of IL-6 in the regulation of glucose homeostasis

AUTHOR(S)
Gusba, Jenny E.
PUB. DATE
February 2009
SOURCE
Applied Physiology, Nutrition & Metabolism;Feb2009, Vol. 34 Issue 1, p83
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
This thesis examined the roles of interleukin (IL)-6 in the regulation of glucose homeostasis, with a specific focus on skeletal muscle. Study 1 sought to determine whether muscle glycogen content is a stimulus for the production of IL-6, examining the periods during and after exercise. The relationship between IL-6 and muscle glycogen content was measured during similar bouts of exhaustive exercise on 2 occasions that resulted in large increases in muscle messenger (m)RNA for IL-6 and circulating levels of IL-6. On 1 occasion, subjects received carbohydrate during recovery to facilitate rates of glycogen resynthesis. During exercise, subjects performed similar bouts of exercise, such that differences in an individual’s glycogen levels between trials could be compared with differences in IL-6. No correlation was detected between the net change in glycogen content and the net change in plasma IL-6 or IL-6 mRNA from rest to exhaustion. Moreover, when the difference within subjects at exhaustion in IL-6 and glycogen was compared, there was no correlation between the 2 variables. During recovery, although carbohydrate intake significantly increased glycogen resynthesis, there was no change in postexercise IL-6 mRNA level or plasma IL-6 concentration. Therefore, glycogen was not the sole regulator of IL-6 production in skeletal muscle. Study 2 examined the direct effect of IL-6 and tumor necrosis factor (TNF)-α on glucose transport and the phosphorylation of key signalling proteins with or without insulin and during rodent muscle contraction. Under basal conditions, IL-6 increased glucose transport in association with an increase in 5′AMP-activated protein kinase (AMPK) and AS160 phosphorylation, but IL-6 decreased insulin-stimulated glucose transport via a reduction in phosphorylation of calcium-calmodulin-dependent protein kinase (CaMK)II and AS160. A novel finding generated from these experiments was the direct involvement of IL-6 in contraction-mediated glucose transport. In the case of muscle contraction, IL-6 was found to increase the phosphorylation of CaMKII and AS160. This research suggests that the activation of CaMKII is involved in the actions of IL-6 under insulin-stimulated and contraction-mediated conditions. Furthermore, AS160 was identified as a common signalling intermediate, influenced by IL-6. It also suggests that AS160 may be a point of convergence for multiple signalling pathways. Finally, the actions of TNF-α mimicked those of IL-6, except during contraction, where TNF-α had no significant effect on glucose transport and attenuated the effects of IL-6.
ACCESSION #
36593560

 

Related Articles

  • Control of CNP homeostasis in herbivore consumers through differential assimilation Logan, J. David; Joern, Anthony; Wolesensky, William // Bulletin of Mathematical Biology;Jul2004, Vol. 66 Issue 4, p707 

    Stoichiometric analysis recognizes that a herbivore is a mixture of multiple chemical elements, especially C, N, and P, that are fixed in various proportions. In the face of a variable quality food supply, herbivores must regulate ingested nutrients to maintain a homeostatic state. We develop a...

  • Cardiac output: a view from Buffalo. Olszowka, A. J.; Shykoff, B. E.; Pendergast, D. R.; Lundgren, C. E. G.; Farhi, L. E. // European Journal of Applied Physiology;Oct2003, Vol. 90 Issue 3/4, p292 

    Cardiac output (Q) is a primary determinant of blood pressure and O2 delivery and is critical in the maintenance of homeostasis, particularly during environmental stress. Cardiac output can be determined invasively in patients; however, indirect methods are required for other situations. Soluble...

  • The interleukin 6 -174G/C Polymorphism is associated with indices of obesity in men. Berthier, M.-T.; Paradis, A.-M.; Tchernof, A.; Bergeron, J.; Prud'homme, D.; Després, J.-P.; Vohl, M.-C. // Journal of Human Genetics;2003, Vol. 48 Issue 1, p14 

    Obesity represents an expansion of adipose tissue (AT) mass and is closely related to insulin resistance and cardiovascular disease. Several hormonal signals have been shown to originate from AT, one of them being interleukin 6 (IL6), for which one third of circulating levels is accounted for by...

  • The Local Control of Blood Flow: An Illustration of Homeostasis. Carrier, Jr., Oliver // BioScience;Oct1965, Vol. 15 Issue 10, p665 

    The article presents information on homeostasis in living organisms. Homeostasis is a process through which the organs and organ systems of organisms maintain an equilibrium with the external environment. There are regulatory mechanisms that react with external stresses such as temperature...

  • Retinol Metabolism in the Mollusk Osilinus lineatus Indicates an Ancient Origin for Retinyl Ester Storage Capacity. Gesto, Manuel; Castro, L. Filipe C.; Reis-Henriques, Maria Armanda; Santos, Miguel Machado // PLoS ONE;Apr2012, Vol. 7 Issue 4, p1 

    Although retinoids have been reported to be present and active in vertebrates and invertebrates, the presence of mechanisms for retinoid storage in the form of retinyl esters, a key feature to maintain whole-organism retinoid homeostasis, have been considered to date a vertebrate innovation....

  • Role of mitochondrial re-energization and Ca2+ influx in reperfusion injury of metabolically inhibited cardiac myocytes Rodrigo, Glenn C.; Standen, Nicholas B. // Cardiovascular Research;Aug2005, Vol. 67 Issue 2, p291 

    Abstract: Objective: We used isolated myocytes to investigate the role of mitochondrial re-energization and Ca2+ influx during reperfusion on hypercontracture, loss of Ca2+ homeostasis and contractile function. Methods: Isolated adult rat ventricular myocytes were exposed to metabolic inhibition...

  • A key stone cop regulates oxalate homeostasis. Kleta, Robert // Nature Genetics;Apr2006, Vol. 38 Issue 4, p403 

    A new study shows that Slc26a6-null mice manifest calcium-oxalate nephrolithiasis accompanied by enhanced net intestinal oxalate absorption. These findings point to a critical role for Slc26a6 in gastrointestinal oxalate secretion and suggest a genetic explanation for a common form of renal...

  • Calcium Homeostasis Change in CD4+ T Lymphocytes from Human Peripheral Blood during Differentiation in vivo. Khaidukov, S. V.; Litvinov, I. S. // Biochemistry (00062979);Jun2005, Vol. 70 Issue 6, p692 

    Resting naive CD4+CD45R0−CD45RA+ T cells are sensitive to ionomycin. In contrast, resting CD4+CD45RA−CD45R0+ memory T cells show resistance to this Ca2+ ionophore. In the present study, the ability of activated T lymphocytes to respond to ionomycin during the transition from naive...

  • Sodium homeostasis: Steady states without a set point. Bonventre, Joseph V.; Leaf, Alexander // Kidney International;Jun1982, Vol. 21 Issue 6, p880 

    Describes the regulation of sodium in the body through a series of steady states determined by many factors including the intake of sodium. Biological control system affecting sodium homeostasis; Effects of sodium intake and urinary sodium excretion; Function of the kidney in dictating the...

Share

Read the Article

Courtesy of VIRGINIA BEACH PUBLIC LIBRARY AND SYSTEM

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics