Features Partner Sites Information LinkXpress
Sign In
Advertise with Us
RANDOX LABORATORIES

Events

05 Mar 2017 - 09 Mar 2017
20 Mar 2017 - 23 Mar 2017
12 Apr 2017 - 14 Apr 2017

Insulin Resistance Also Mediated by White Blood Cells

By BiotechDaily International staff writers
Posted on 13 Aug 2012
Image: False-color scanning electron micrograph (SEM) of a neutrophil (Photo courtesy of UC San Diego School of Medicine).
Image: False-color scanning electron micrograph (SEM) of a neutrophil (Photo courtesy of UC San Diego School of Medicine).
ADVERTISEMENT
SARTORIUS AG
Researchers have now found that neutrophils play a role in mediating the development of insulin resistance, the central characteristic of type 2 diabetes. The discovery also provides a potential new treatment target.

Using live mouse models as well as cultured liver and fat cells, a study team based at the University of California, San Diego, School of Medicine (La Jolla, CA, USA) discovered that an enzyme secreted by neutrophils called neutrophil elastase (NE) impairs insulin signaling and boosts resistance. Conversely, deletion of NE in obese mice fed a high-fat diet improved insulin sensitivity. “These results are largely unexpected. Although several immune cells have been established in the etiology of insulin resistance, the role of neutrophils in this process has remained unclear until now,” said Da Young Oh, co-author and assistant project scientist in the laboratory of study leader Jerrold M. Olefsky, MD and professor of medicine.

Chronic low-grade inflammation is an important cause of systemic insulin resistance. Neutrophils are the first immune cells to respond to tissue inflammation and can promote chronic inflammation by helping to recruit additional white blood cells - macrophages. Oh noted that neutrophils were considered to be “transient infiltrates” incapable of sustaining chronic, low-grade inflammation. “Our studies now suggest neutrophils possess powerful immune modulatory effects,” Oh said. Specifically, neutrophils use NE to activate a signaling pathway that triggers macrophages to secrete proinflammatory cytokines. NE degrades IRS1, a key protein in the insulin-signaling pathway in both liver and fat cells. The scientists noted that although NE has been shown to degrade this protein in lung cancer cells, the effect on insulin target tissues such as liver and adipose is striking.

The insulin-mediating role of neutrophils makes them a new target for developing treatments of insulin resistance in particular and diabetes in general. “One could, in theory, take an NE activity inhibitory approach to reverse or improve insulin resistance,” Oh said, noting that NE inhibiting drugs are already used for treatment of emphysema in Japan and are being tested in the United States for both emphysema and type 1 diabetes.

The findings have been reported in the August 5, 2012, advance online edition of the journal Nature Medicine.

Related Links:

University of California, San Diego, School of Medicine



Channels

Biochemistry

view channel
Image: A space-filling model of the anticonvulsant drug carbamazepine (Photo courtesy of Wikimedia Commons).

Wastewater May Contaminate Crops with Potentially Dangerous Pharmaceuticals

Reclaimed wastewater used to irrigate crops is contaminated with pharmaceutical residues that can be detected in the urine of those who consumed such produce. Investigators at the Hebrew University... Read more

Business

view channel

Collaborative Agreement to Aid in Setting Guidelines for Evaluating Potential Ebola Therapy

Cooperation between an Israeli biopharmaceutical company and medical branches of the US government is designed to set ground rules for continued evaluation of an experimental therapy for Ebola virus disease. RedHill Biopharma Ltd. (Tel Aviv, Israel), a biopharmaceutical company primarily focused on development and c... Read more
Copyright © 2000-2016 Globetech Media. All rights reserved.