Lymphocyte-induced stimulation of the contractile response of the heart

Targeting Insulin-Degrading Enzyme in Insulin Clearance

Hepatic insulin clearance, a physiological process that in response to nutritional cues clears ~50–80% of circulating insulin, is emerging as an important factor in our understanding of the pathogenesis of type 2 diabetes mellitus (T2DM). Insulin-degrading enzyme (IDE) is a highly conserved Zn²⁺-metalloprotease that degrades insulin and several other intermediate-size peptides. Both, insulin clearance and IDE activity are reduced in diabetic patients, albeit the cause-effect relationship in humans remains unproven. Because historically IDE has been proposed as the main enzyme involved in insulin degradation, efforts in the development of IDE inhibitors as therapeutics in diabetic patients has attracted attention during the last decades. In this review, we retrace the path from Mirsky’s seminal discovery of IDE to the present, highlighting the pros and cons of the development of IDE inhibitors as a pharmacological approach to treating diabetic patients.

Stimulation of heart contractility by supernatants from lectin-activated lymphocytes. Role of IL-2

The positive inotropic effect of cell-free supernatants from lectin-activated lymphocytes is lost by dialysis and can be partially restored by addition of arachidonic acid (AA). Interleukin-2 (IL-2) in the presence of AA could stimulate the response of the heart while the interferons (alpha-IFN or gamma-IFN) were ineffective. The activity of PHA-L-SN and that of IL-2 + AA was neutralized by anti-IL-2 MAb. These results suggest a key role for IL-2 in the stimulation of heart contractility by supernatants from activated lymphocytes.