Medindia
Advertisement

How 'Body Clock' Dysregulation Underlies Obesity Highlighted in Texas A&M Study

by Kathy Jones on May 15, 2014 at 8:53 PM
Font : A-A+

 How 'Body Clock' Dysregulation Underlies Obesity Highlighted in Texas A&M Study

The way in which "body clock dysregulation" might affect obesity-related metabolic disorders has been investigated by a team of Texas A&M University System scientists.

The team was led by Dr. Chaodong Wu, associate professor in the department of nutrition and food sciences of Texas A&M's College of Agriculture and Life Sciences, and Dr. David Earnest, professor in the department of neuroscience and experimental therapeutics, Texas A&M Health Science Center.

Advertisement

Study results were published recently on the Journal of Biological Chemistry website at www.jbc.org/content/early/2014/04/25/jbc.M113.539601.

"Animal sleeping and eating patterns, including those of humans, are subject to a circadian rhythmicity," Earnest said. "And previous studies have shown an association between the dysregulation of circadian or body clock rhythms and some metabolic disorders."
Advertisement

Wu said circadian clocks in peripheral tissues and cells drive daily rhythms and coordinate many physiological processes, including inflammation and metabolism.

"And recent scientific observations suggest that disruption of circadian clock regulation plays a key role in the development of metabolic diseases, including obesity and diabetes," he noted.

He said this study affirms that eating unhealthy foods causes health problems and that it's much worse to eat unhealthy foods at the wrong time. It also indicates that "time-based treatment may provide better management of metabolic diseases.

"To promote human health, we need not only to eat healthy foods, but also more importantly to keep a healthy lifestyle, which includes avoiding sleeping late and eating at night," he said.

Wu and Earnest said while previous studies using mice with genetic mutation of the removal of core clock genes has indicated that specific disruption of circadian clock function alters metabolism or produces obesity, the mechanism remained unknown. As key components of inflammation in obesity, macrophages, which are immune cells, contain cell-autonomous circadian clocks that have been shown to gate inflammatory responses.

"Our hypothesis was that overnutrition causes circadian clock dysregulation, which induces pro-inflammatory activity in adipose tissue. This then worsens inflammation and fat deposition, leading to systematic insulin resistance," Wu said.

To test the hypothesis, the team conducted experiments with "reporter mice" in which the circadian rhythmicity of various types of cells could be monitored by looking at their reporter activity. Accordingly, the reporter mice were put on a 12-hour light-dark cycle and were fed a high-fat diet. Additional reporter mice were fed a low-fat diet and served as controls. In this set of experiments, the team was able to characterize the effects of a high-fat diet on circadian clock rhythmicity and inflammatory responses in immune cells, or macrophages.

To further define a unique role for circadian clock dysregulation in metabolic disorders, the team conducted "bone marrow transplantation" experiments, through which the rhythmicity of circadian clocks was disrupted only in a specific type of immune cells. After high-fat diet feeding, the transplanted mice were used for collection of blood and tissue samples. A number of physiological and immunological assays also were performed on the mice.

Earnest said results showed that during obesity, that is when mice were fed a high-fat diet, the rhythmicity of circadian clocks in immune cells of fat tissue is dysregulated by a prolonged rhythmic period. This is, in turn, is linked to increased accumulation of immune cells in fat tissue and decreased whole-body insulin sensitivity.

"Animals on a high-fat diet display metabolic problems associated with obesity," Earnest said. "The problems are worsened in animals whose circadian clocks in immune cells are disrupted."

Earnest and Wu said the study will help those involved in human health and nutrition better understand the underlying mechanisms related to obesity and diabetes.



Source: Eurekalert
Advertisement

Advertisement
News A-Z
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
News Category
What's New on Medindia
Sedentary Behavior Precipitates Night-Time Hot Flashes
Gonorrhea
World Alzheimer's Day 2021 - 'Know Dementia, Know Alzheimer's
View all

Medindia Newsletters Subscribe to our Free Newsletters!
Terms & Conditions and Privacy Policy.

More News on:
Bariatric Surgery Obesity Bulimia Nervosa Body Mass Index Liposuction Battle of the Bulge Diabesity Hunger Fullness and Weight Control Diet and Nutrition for Healthy Weight Loss Diabetes Type 2 and Its Link to Sugar-Sweetened Beverages 

Recommended Reading
Sleep Disorder
Sleep disorders can either be having difficulty in getting sleep or dozing off at inappropriate ......
Sleep Disturbances In Women
The physical, emotional and hormonal changes that occur in women during puberty, menstrual cycle, .....
Circadian Rhythm Sleep Disorders
Circadian rhythm (also known as sleep/wake cycle or the body clock) is a biological process that ......
Battle of the Bulge
The ‘battle of bulge’ is the toughest of all battles. Once you put on weight it is so difficult to g...
Body Mass Index
Body mass index (BMI) is a simple tool that is generally used to estimate the total amount of body f...
Bulimia Nervosa
The term ''Bulimia'' refers to episodes of uncontrolled excessive eating, known as "binges," followe...
Diabesity
With more than one billion people affected, diabesity is the largest epidemic in the world today. Fo...
Diabetes Type 2 and Its Link to Sugar-Sweetened Beverages
Sugar-sweetened beverages contribute to metabolic syndrome leading to higher risk for type-2 diabete...
Diet and Nutrition for Healthy Weight Loss
Correct diet and a planned exercise regime is the mantra of healthy and sustainable weight loss....
Hunger Fullness and Weight Control
An erratic way of eating or any metabolic disturbance in the hunger fullness signals is one of the m...
Liposuction
Liposuction is a cosmetic procedure, which is used to suck out the excess or abnormal fat deposition...
Obesity
Obesity is a condition where there is excess accumulation of body fat which poses a risk to the heal...

Disclaimer - All information and content on this site are for information and educational purposes only. The information should not be used for either diagnosis or treatment or both for any health related problem or disease. Always seek the advice of a qualified physician for medical diagnosis and treatment. Full Disclaimer

© All Rights Reserved 1997 - 2021

This site uses cookies to deliver our services. By using our site, you acknowledge that you have read and understand our Cookie Policy, Privacy Policy, and our Terms of Use