Molecular mechanisms involved in obesity-associated insulin resistance: Therapeutical approach

Abstract

Insulin resistance is an important contributor to the pathogenesis of T2D and obesity is a risk factor for its development. It has been demonstrated that these obesity-related metabolic disorders are associated with a state of chronic low-intensity inflammation. Several mediators released from adipocytes and macrophages, such as the pro-inflammatory cytokines TNF-alpha and IL-6, have been suggested to impair insulin action in peripheral tissues, including fat and skeletal muscle. Such insulin resistance can initially be compensated by increased insulin secretion, but the prolonged presence of the hormone is detrimental for insulin sensitivity. Stress and pro-inflamatory kinases as well as more recent players, phosphatases, seem to be involved in the molecular mechanisms by which pro-inflammatory cytokines and hyperinsulinemia disrupt insulin signalling at the level of IRSs. Pharmacological approaches, such as treatment with PPAR and LXR agonists, overcome such insulin resistance, exerting anti-inflamatory properties as well as controlling the expression of cytokines with tissular specificity.

Keywords::

• GLUT4
• cytokines
• hyperinsulinemia
• PTP1B
• stress and proinflammatory kinases
• nuclear receptor agonists
• insulin resistance
• obesity

Acknowledgements

This work was supported by grants BFU2008-04043 from Ministerio de Ciencia e Innovacion, Spain, S-SAL-0159-2006 from Comunidad de Madrid, Spain. CIBER de Diabetes y Enfermedades Metabolicas Asociadas is an ISCIII project. We also acknowledge the support of COST Action BM0602 from the European Commission. We thank L. Muñoz and E. Gonzalez from Universidad Complutense for their experimental and administrative support.

Decleration of Interest: The authors report no conflict of interest.