Reactive oxygen species (ROS or free radicals) are signal mediators in physiological condition. Over production of ROS is able to induce many side effects such as cell apoptosis, inflammation, and gene mutation, which has been well documented in cancer, immunology and aging fields. A role of ROS in the pathogenesis of insulin resistance has been speculated for some times. However, there was no direct evidence to support this possibility. This condition is changed by a new study in the current issue of Nature. The report suggests that ROS is required for development of insulin resistance in response to TNF-alpha or glucocortcoide hormone. Attached is the paper that is recommended by Dr. Hong-Ping Guan at UT Southwestern Medical Center. (Attachment 1)

ROS is able to activate signaling molecules such as JNK, and NF-kB, which are known to contribute to insulin resistance. In Nature Medicine, a study shows that ROS is able to activate MAP kinase p38 to reduce life span of hemopoietic stem cells (Attachment 2).

By Jianping at PBRC
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Jianping Ye, MD
Associate Professor
Pennington Biomedical Research Center
Louisiana State University
6400 Perkins Road
Baton Rouge, LA 70808
Phone: (225) 763-3163
Fax: (225) 763-2525
E-mail: yej@pbrc.edu