Inputs and outputs of insulin receptor

The insulin receptor (IR) is an important hub in insulin signaling and its activation is tightly regulated. Upon insulin stimulation, IR is activated through autophosphorylation, and consequently phosphorylates several insulin receptor substrate (IRS) proteins, including IRS1-6, Shc and Gab1. Certain adipokines have also been found to activate IR. On the contrary, PTP, Grb and SOCS proteins, which are responsible for the negative regulation of IR, are characterized as IR inhibitors. Additionally, many other proteins have been identified as IR substrates and participate in the insulin signaling pathway. To provide a more comprehensive understanding of the signals mediated through IR, we reviewed the upstream and downstream signal molecules of IR, summarized the positive and negative modulators of IR, and discussed the IR substrates and interacting adaptor proteins. We propose that the molecular events associated with IR should be integrated to obtain a better understanding of the insulin signaling pathway and diabetes.

Interleukin-32, not reduced by salmeterol/fluticasone propionate in smokers with chronic obstructive pulmonary disease / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The interleukin (IL)-32/tumor necrosis factor (TNF) a pathway is supposed to play a key role in the amplification of the immune response in chronic obstructive pulmonary disease (COPD) inflammation. Inhaled corticosteroids (ICS) in combination with long-acting β2-agonists (LABA) have shown airway anti-inflammatory effects in recent studies, but the mechanism is still uncertain.</p><p><b>METHODS</b>Patients were treated in a randomized, open-labeled, parallel group clinical trial with either a combination of salmeterol xinafoate/fluticasone propionate (SF; Seretide, GlaxoSmithKline) Diskus (50/500 µg twice daily) or ipratropium bromide/salbutamol (IS; Combivent, Boehringer Ingelheim) MDI (42 µg/240 µg quartic daily) for 12 weeks. At the start and the end of treatment, induced sputum was collected and the concentration of IL-32 and TNF-α, the number of neutrophils and eosinophils were measured.</p><p><b>RESULTS</b>Following 12 weeks of treatment, a statistically significant fall from baseline in the concentration of TNF-α in sputum (P = 0.004) was seen after treatment with SF but not with IS. However, neither treatment had significant effects on the concentration of IL-32 in sputum. There was a decrease from baseline in the number of sputum neutrophils with SF that approached statistical significance (P = 0.028) but not with IS, while the number of sputum eosinophils did not change significantly from baseline in either treatment group. There was a statistically significant decline from baseline in the quality of life as assessed by the St George's respiratory questionnaire in both the SF (P = 0.004) and IS (P = 0.030) treatment groups, but no evidence of improvement in lung function was observed in either group.</p><p><b>CONCLUSION</b>The sputum TNF-α and neutrophils, but not IL-32 and macrophages, could be reduced by ICS/LABA treatment, suggesting that IL-32 could be involved in the corticosteroid resistance of COPD inflammation.</p>