PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Reducing liver protein SIRT1 levels

2014-01-22
(Press-News.org) Contact information: Jenny Eriksen Leary
jenny.eriksen@bmc.org
617-638-6841
Boston University Medical Center
Reducing liver protein SIRT1 levels (Boston) – A new study led by Boston University School of Medicine (BUSM) demonstrates that the abnormal metabolism linked to obesity could be regulated in part by the interaction of two metabolic regulators, called the NAD-dependent deacetylase SIRT1 and fibroblast growth factor 21 (FGF21). Using experimental models, the researchers found that a lack of SIRT1 protein in the liver led to lower levels of a liver secreted protein FGF21, which resulted in an increased likelihood of developing fatty liver disease and obesity.

When levels of FGF21 in the liver of experimental models were elevated, some of the white fat cells became some of brown fat cells, producing more heat and burned calories. White fat stores energy as large fat droplets, while brown fat has much smaller fat droplets and is specialized to burn them, yielding heat. In humans, there is evidence that more brown fat is associated with a lower body weight. Finding a way to turn white fat into brown fat could potentially lead to a decrease in obesity and other metabolic diseases.

This study, which is published in Gastroenterology, was led by Mengwei Zang, MD, PhD, and her team in the department of medicine at BUSM.

In previous experiments, Zang's laboratory showed that elevated liver SIRT1 protein limited the development of fatty liver in experimental models when the diet was high in fat. However, the mechanism was not known. To determine how this happens, Zang laboratory used a unique mouse model that did not have liver SIRT1 protein, which resulted in an elevation in hepatic fat levels, an increase in body weight, and a decrease in nighttime oxygen consumption. It also led to decreased levels of liver FGF21, which were associated with abnormal fat metabolic changes in liver and adipose tissues.

However, when levels of liver and serum FGF21 were elevated, some white fat cells changed and became brown fat cells, which could increase whole-body oxygen consumption and produce more heat. These changes in the fat cells caused by elevated FGF21 protein could help explain how the experimental mice experienced more weight loss, had less fat mass and slowed the progression of fatty liver.

"Excess abdominal white fat in humans promotes heart disease, diabetes and other metabolic diseases, and it would be potentially therapeutic if we could transform white fat into brown fat by elevating FGF21 levels," said Zang, the study's corresponding author.

### Funding for this study was provided in part by the National Institutes of Health Grants RO1 DK076942 and R21 AA021181, Robert Dawson Evans Faculty Merit Award, and Wing Tat Lee Award.


ELSE PRESS RELEASES FROM THIS DATE:

Polar bear diet changes as sea ice melts

2014-01-22
Polar bear diet changes as sea ice melts 3-part study shows that some Hudson Bay polar bears are switching prey, mixing plant and animal food sources as they survive in changing enviroment A series of papers recently published by scientists at the American ...

Hospitals and nursing homes can learn much from hospice care

2014-01-22
Hospitals and nursing homes can learn much from hospice care Basic hospice strategies can make last days of dying inpatients more comfortable and dignified There is much value in training hospital and nursing home staff in the basics of palliative care to make the last ...

New poll finds diabetes top health concern for Latino families

2014-01-22
New poll finds diabetes top health concern for Latino families Boston, MA – A new NPR/Robert Wood Johnson Foundation/Harvard School of Public Health poll was released today on the views of Latinos in America about their health and health care, communities, ...

UM study finds wolf predation of cattle affects calf weight in Montana

2014-01-22
UM study finds wolf predation of cattle affects calf weight in Montana MISSOULA – A recent study by University of Montana faculty and graduate students found that wolf predation of cattle contributes to lower weight gain in calves on western Montana ...

Researcher proves mass important at nano-scale, matters in calculations and measurements

2014-01-22
Researcher proves mass important at nano-scale, matters in calculations and measurements New model drastically reduces run times A UT Arlington engineering professor has proven that the effect of mass is important, can be measured and has a significant impact on ...

Analysis of salamander jump reveals an unexpected twist

2014-01-22
Analysis of salamander jump reveals an unexpected twist A small, secretive creature with unlikely qualifications for defying gravity may hold the answer to an entirely new way of getting off the ground. Salamanders—or at least several species of the Plethodontidae ...

CU-built software uses big data to battle forgetting with personalized content review

2014-01-22
CU-built software uses big data to battle forgetting with personalized content review Computer software similar to that used by online retailers to recommend products to a shopper can help students remember the content they've studied, according to a new study by the University ...

Common blood cancer may be initiated by single mutation in bone cells

2014-01-22
Common blood cancer may be initiated by single mutation in bone cells Potential drug target in bone cells may help 40 percent of patients with mutation NEW YORK, NY (January 21, 2014) — Acute myeloid leukemia (AML) is a blood cancer, but for many ...

Predatory organisms at depth

2014-01-22
Predatory organisms at depth Viruses within the ocean floor comprise the greatest fraction of the deep biosphere In the current issue of the Journal of the International Society for Microbial Ecology (ISME Journal, 20.1.2014) scientists ...

Mayo Clinic research finds risk of glaucoma blindness drops by half

2014-01-22
Mayo Clinic research finds risk of glaucoma blindness drops by half ROCHESTER, Minn. — Jan. 21 — A comparative long-range study by Mayo Clinic ophthalmology researchers shows that the probability of blindness from glaucoma 20 years after diagnosis has dropped by half in the last ...

LAST 30 PRESS RELEASES:

New strategies to enhance chiral optical signals unveiled

Cambridge research uncovers powerful virtual reality treatment for speech anxiety

2025 Gut Microbiota for Health World Summit to spotlight groundbreaking research

International survey finds that support for climate interventions is tied to being hopeful and worried about climate change

Cambridge scientist launches free VR platform that eliminates the fear of public speaking

Open-Source AI matches top proprietary model in solving tough medical cases

Good fences make good neighbors (with carnivores)

NRG Oncology trial supports radiotherapy alone following radical hysterectomy should remain the standard of care for early-stage, intermediate-risk cervical cancer

Introducing our new cohort of AGA Future Leaders

Sharks are dying at alarming rates, mostly due to fishing. Retention bans may help

Engineering excellence: Engineers with ONR ties elected to renowned scientific academy

New CRISPR-based diagnostic test detects pathogens in blood without amplification

Immunotherapy may boost KRAS-targeted therapy in pancreatic cancer

Growing solar: Optimizing agrivoltaic systems for crops and clean energy

Scientists discover how to reactivate cancer’s molecular “kill switch”

YouTube influencers: gaming’s best friend or worst enemy?

uOttawa scientists use light to unlock secret of atoms

NJIT mathematician to help map Earth's last frontier with Navy grant

NASA atmospheric wave-studying mission releases data from first 3,000 orbits

‘Microlightning’ in water droplets may have sparked life on Earth

Smoke from wildland-urban interface fires more deadly than remote wildfires

What’s your body really worth? New AI model reveals your true biological age from 5 drops of blood

Protein accidentally lassos itself, helping explain unusual refolding behavior

With bird flu in raw milk, many in U.S. still do not know risks of consuming it

University of Minnesota research team awarded $3.8 million grant to develop cell therapy to combat Alzheimer’s disease

UConn uncovers new clue on what is leading to neurodegenerative diseases like Alzheimer’s and ALS

Resuscitation in out-of-hospital cardiac arrest – it’s how quickly it is done, rather than who does it

A closer look at biomolecular ‘silly putty’

Oxytocin system of breastfeeding affected in mothers with postnatal depression

Liquid metal-enabled synergetic cooling and charging: a leap forward for electric vehicles

[Press-News.org] Reducing liver protein SIRT1 levels