Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Joslin researchers uncover potential role of leptin in diabetes

05.10.2007
A new Joslin-led study has shown that leptin, a hormone known mainly for regulating appetite control and energy metabolism, plays a major role in islet cell growth and insulin secretion. This finding opens up new avenues for studying leptin and its role in islet cell biology, which may lead to new treatments for diabetes. This study appears in the October 2007 issue of The Journal of Clinical Investigation.

Previous in vitro studies suggested that leptin receptors, which are found in tissues throughout the body including the pancreas as well as the brain, mediate leptin-induced inhibition of insulin secretion in islet cells, also known as beta cells. “We wanted to further our understanding of leptin and its role in beta cells independent of its effects in the brain,” said Rohit N. Kulkarni, M.D., Ph.D., principal investigator at Joslin Diabetes Center and Assistant Professor of Medicine at Harvard Medical School, who led this study. It is currently not known why obese individuals exhibit a high incidence of diabetes despite high levels of both insulin and leptin circulating in the bloodstream.

To understand the role of leptin in the islets, researchers developed a mouse model (known as a “knock out” or KO mouse) genetically engineered not to produce leptin receptors in the pancreas, while maintaining the receptors in the brain and the rest of the body. Researchers found that the mice lacking leptin receptors in the pancreas showed improved glucose tolerance and greater insulin secretion and beta cell growth. “Since the normal function of leptin is to keep insulin levels from getting too high, the lack of leptin enhances insulin action in the beta cells and promotes insulin secretion, which was the result we expected,” said Dr. Kulkarni.

In the second part of the study, the KO mice and a control group of mice with intact leptin receptors were placed on a high-fat diet. Although both the control and KO mice became obese, only the KO mice developed severe glucose intolerance and insulin resistance, a precursor to the development of diabetes. “These novel results indicate that in the presence of obesity, the combination of insulin resistance in the beta cell and the lack of leptin signaling leads to poor beta cell growth and function leading to glucose intolerance. Interactions between leptin and insulin signaling in the beta cell need to be considered to understand the relationship between diabetes and obesity,” said Dr. Kulkarni.

Obesity is a major risk factor for the development of type 2 diabetes, the most common form of the disease. Other risk factors are age (over 40) and a family history of diabetes, although today it is increasing prevalent in younger people, including adolescents. In type 2 diabetes, islet cells malfunction and the body is unable to compensate by growing more beta cells. By investigating the cellular mechanisms that affect islet cell development and growth, Joslin researchers hope to find better ways to prevent and treat the disease.

Follow-up studies will focus on examining the interactions between insulin and leptin signaling in beta cells and identifying the key proteins found in the pathways that regulate beta cell growth and activity. This could lead to the development of therapeutic drugs that manipulate these proteins to influence beta cell growth and function. “Unraveling the role of leptin in the regulation of beta cell biology will be especially useful in understanding the mechanisms that contribute to beta cell growth with implications for the treatment of both type 1 and type 2 diabetes,” said Dr. Kulkarni.

Jenny Eriksen | EurekAlert!
Further information:
http://www.joslin.harvard.edu

More articles from Health and Medicine:

nachricht NTU scientists build new ultrasound device using 3-D printing technology
07.12.2016 | Nanyang Technological University

nachricht How to turn white fat brown
07.12.2016 | University of Pennsylvania School of Medicine

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

NTU scientists build new ultrasound device using 3-D printing technology

07.12.2016 | Health and Medicine

The balancing act: An enzyme that links endocytosis to membrane recycling

07.12.2016 | Life Sciences

How to turn white fat brown

07.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>