Nav: Home

Study identifies enzyme that protects cells from toxic fat

August 01, 2017

Key takeaway:
  • The enzyme--DGAT1--ensures that toxic fats don't damage a key organelle within cells


Boston, Mass. - A new study from Harvard T.H. Chan School of Public Health and Howard Hughes Medical Institute sheds light on how a key fat-producing enzyme helps protect cells from a toxic form of fat.

The new finding contributes to a fuller understanding of the fundamental biology that underlies common metabolic diseases related to obesity, such as type 2 diabetes, fatty liver disease, and heart failure, and could lead to new insights on how to better treat such diseases.

The study will be published online August 1, 2017 in Cell Metabolism.

"We are excited about these findings--they solve a mystery and show how fat synthesis protects cells from dysfunction and disease," said Robert Farese, Jr., professor of genetics and complex diseases at Harvard Chan School.

Lead author of the study was Harvard Chan research fellow Chandramohan Chitraju.

The researchers looked at what happens to triglycerides (a type of fat) in cells during lipolysis, the process through which the triglycerides are broken down into fatty acids and transported for energy use to other tissues in the body. For decades, scientists have wondered why some triglycerides, after being broken down into fatty acids, wind up back in the cells in the form of triglycerides--a process known as "re-esterification."

By examining cell processes both in mice and in human cells, the researchers found out why: Re-esterification helps protect a key cell organelle called the endoplasmic reticulum (ER). The ER helps make cellular products such as proteins and lipids and it can be damaged by fatty acids--but not by triglycerides. The researchers also found that an enzyme called DGAT1 (diacylglycerol acyltransferase) is crucial to the re-esterification process, acting as a sort of cell police officer to ensure that toxic fatty acids stay away from the ER.

"To better understand what happens when cells are overwhelmed with fat during obesity, we first have to understand how the system normally deals with fluctuations in lipids," said Tobias Walther, professor of genetics and complex diseases at Harvard Chan and co-senior author of the study. "Our findings will hopefully spark new ideas on how to prevent the health consequences of obesity."
-end-
Harvard Chan School's Niklas Mejhert was also a co-author.

This work was supported by National Institutes of Health grants (R01 DK101579, R01 DK056084, R01 GM097194), the American Diabetes Association, the Howard Hughes Medical Institute, and seed funding from the Gladstone Institute.

"Triglyceride Synthesis by DGAT1 Protects Adipocytes from Lipid-Induced ER Stress during Lipolysis," Chandramohan Chitraju, Niklas Mejhert, Joel T. Haas, L. Grisell Diaz-Ramirez, Carrie A. Grueter, Jason E. Imbriglio, Shirly Pinto, Suneil K. Koliwad, Tobias C. Walther, Robert V. Farese, Jr., Cell Metabolism, August 1, 2017, doi: 10.1016/j.cmet.2017.07.012

Visit the Harvard Chan School website for the latest news, press releases, and multimedia offerings.

Harvard T.H. Chan School of Public Health brings together dedicated experts from many disciplines to educate new generations of global health leaders and produce powerful ideas that improve the lives and health of people everywhere. As a community of leading scientists, educators, and students, we work together to take innovative ideas from the laboratory to people's lives--not only making scientific breakthroughs, but also working to change individual behaviors, public policies, and health care practices. Each year, more than 400 faculty members at Harvard Chan School teach 1,000-plus full-time students from around the world and train thousands more through online and executive education courses. Founded in 1913 as the Harvard-MIT School of Health Officers, the School is recognized as America's oldest professional training program in public health.

Harvard T.H. Chan School of Public Health

Related Obesity Articles:

Changing the debate around obesity
The UK's National Health Service (NHS) needs to do more to address the ingrained stigma and discrimination faced by people with obesity, says a leading health psychologist.
Study links longer exposure to obesity and earlier development of obesity to increased risk of type 2 diabetes
Cumulative exposure to obesity could be at least as important as actually being obese in terms of risk of developing type 2 diabetes (T2D), concludes new research published in Diabetologia (the journal of the European Association for the Study of Diabetes [EASD]).
How much do obesity and addictions overlap?
A large analysis of personality studies has found that people with obesity behave somewhat like people with addictions to alcohol or drugs.
Should obesity be recognized as a disease?
With obesity now affecting almost a third (29%) of the population in England, and expected to rise to 35% by 2030, should we now recognize it as a disease?
Is obesity associated with risk of pediatric MS?
A single-center study of 453 children in Germany with multiple sclerosis (MS) investigated the association of obesity with pediatric MS risk and with the response of first-line therapy in children with MS.
Women with obesity prior to conception are more likely to have children with obesity
A systematic review and meta-analysis identified significantly increased odds of child obesity when mothers have obesity before conception, according to a study published June 11, 2019 in the open-access journal PLOS Medicine by Nicola Heslehurst of Newcastle University in the UK, and colleagues.
Obesity medicine association announces major updates to its adult obesity algorithm
The Obesity Medicine Association (OMA) announced the immediate availability of the 2019 OMA Adult Obesity Algorithm, with new information for clinicians including the relationship between Obesity and Cardiovascular Disease, Diabetes Mellitus, Dyslipidemia, and Cancer; information on investigational Anti-Obesity Pharmacotherapy; treatments for Lipodystrophy; and Pharmacokinetics and Obesity.
Systematic review shows risk of a child developing overweight or obesity is more than trebled by maternal obesity prior to pregnancy
New research presented at this year's European Congress on Obesity (ECO) in Glasgow, Scotland (April 28- May 1) reveals that the risk of a child becoming overweight or obese is more than trebled by maternal obesity prior to getting pregnant.
Eating later in the day may be associated with obesity
Eating later in the day may contribute to weight gain, according to a new study to be presented Saturday at ENDO 2019, the Endocrine Society's annual meeting in New Orleans, La.
How obesity affects vitamin D metabolism
A new Journal of Bone and Mineral Research study confirms that vitamin D supplementation is less effective in the presence of obesity, and it uncovers a biological mechanism to explain this observation.
More Obesity News and Obesity Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: Reinvention
Change is hard, but it's also an opportunity to discover and reimagine what you thought you knew. From our economy, to music, to even ourselves–this hour TED speakers explore the power of reinvention. Guests include OK Go lead singer Damian Kulash Jr., former college gymnastics coach Valorie Kondos Field, Stockton Mayor Michael Tubbs, and entrepreneur Nick Hanauer.
Now Playing: Science for the People

#562 Superbug to Bedside
By now we're all good and scared about antibiotic resistance, one of the many things coming to get us all. But there's good news, sort of. News antibiotics are coming out! How do they get tested? What does that kind of a trial look like and how does it happen? Host Bethany Brookeshire talks with Matt McCarthy, author of "Superbugs: The Race to Stop an Epidemic", about the ins and outs of testing a new antibiotic in the hospital.
Now Playing: Radiolab

Dispatch 6: Strange Times
Covid has disrupted the most basic routines of our days and nights. But in the middle of a conversation about how to fight the virus, we find a place impervious to the stalled plans and frenetic demands of the outside world. It's a very different kind of front line, where urgent work means moving slow, and time is marked out in tiny pre-planned steps. Then, on a walk through the woods, we consider how the tempo of our lives affects our minds and discover how the beats of biology shape our bodies. This episode was produced with help from Molly Webster and Tracie Hunte. Support Radiolab today at Radiolab.org/donate.