Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Pyruvate oxidation is critical determinant of pancreatic islet number and β-cell mass

06.08.2014

Researchers at the University at Buffalo, led by Dr. Mulchand Patel and also at Lawson Health Research Institute and Western Ontario, London, Canada, led by Dr. David Hill, collaboratively evaluated the role of the mitochondrial multienzyme pyruvate dehydrogenase complex in the regulation of pancreatic β-cell development and maturation in the immediate postnatal period in mice.

This study, reported in the August 2014 issue of Experimental Biology and Medicine, demonstrated that the pyruvate dehydrogenase complex is not only required for insulin gene expression and glucose-stimulated insulin secretion, but also directly influences β-cell growth and maturity. This places glucose metabolism as a direct regulator of β-cell mass and plasticity.

Glucose metabolism within the pancreatic β-cells is crucial for insulin gene expression and hormone exocytosis, but there is increasing evidence that glucose metabolic pathways are also important for β-cell development and the maintenance of β-cell mass in adult life.

A targeted deletion of glucokinase in mouse β-cells not only prevents glucose-stimulated insulin secretion, but also β-cell proliferation and is associated with increased apoptosis. A direct manipulation of glucose availability to the embryonic pancreas in tissue culture showed that it was necessary for both α- and β-cell development through the regulation of the transcription factors Neurogenin 3 (Neurog3) and NeuroD.

In the article by Patel et al., the authors show that a targeted β-cell deletion of the α subunit of the pyruvate dehydrogenase component, a major rate-limiting enzyme for the pyruvate dehydrogenase complex that regulates pyruvate metabolism from glucose in the mitochondria, in mouse resulted in reduced insulin availability and glucose-sensitive release as would be expected.

But they also demonstrate that β-cell number was reduced postnatally as was the expression of Neurog3, NeuroD and Pdx1. Interestingly, there was also a reduction in the numbers of insulin-immunopositive, extra-islet small endocrine cell clusters, a possible source of new β-cells from progenitors.

The new findings reinforce the concept that pathways controlling glucose metabolism in β-cells are as important for maintenance of β-cell mass as are hormones and growth factors, such as glucagon-like polypeptide 1 (GLP1).

"These findings show that glucose metabolism is a major regulator of β-cell mass which is likely to act independently of other signaling pathways, such as insulin receptor substrate 2", said Dr. Mulchand Patel, senior author of the study and SUNY Distinguished Professor, Department of Biochemistry, School of Medicine and Biomedical Sciences, University at Buffalo, the State University of New York.

Dr. Steven R. Goodman, Editor-in-Chief of Experimental Biology and Medicine, said "the study by Patel et al utilizes a mouse knockout model to disrupt the pyruvate dehydrogenase complex (PDC) activity to study the role of PDC in pancreatic β-cell development. They demonstrate that PDC has a direct impact upon the regulation of β-cell mass as well as plasticity."

###

Experimental Biology and Medicine is a journal dedicated to the publication of multidisciplinary and interdisciplinary research in the biomedical sciences. The journal was first established in 1903. Experimental Biology and Medicine is the journal of the Society of Experimental Biology and Medicine. To learn about the benefits of society membership visit http://www.sebm.org. If you are interested in publishing in the journal please visit http://ebm.sagepub.com/.

M.S. Patel | Eurek Alert!

Further reports about: Biology Medicine SUNY dehydrogenase islet metabolism pancreatic pathways plasticity

More articles from Life Sciences:

nachricht Could this protein protect people against coronary artery disease?
17.11.2017 | University of North Carolina Health Care

nachricht Microbial resident enables beetles to feed on a leafy diet
17.11.2017 | Max-Planck-Institut für chemische Ökologie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

NASA detects solar flare pulses at Sun and Earth

17.11.2017 | Physics and Astronomy

NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures

17.11.2017 | Health and Medicine

The importance of biodiversity in forests could increase due to climate change

17.11.2017 | Studies and Analyses

VideoLinks
B2B-VideoLinks
More VideoLinks >>>