Obesity suppresses cellular process critical to kidney health

October 5, 2013, American Society of Nephrology

Obesity increases a chronic kidney disease patient's risk of developing kidney failure.

Obesity suppresses an important cellular process that prevents kidney cell damage, according to a study appearing in an upcoming issue of the Journal of the American Society of Nephrology (JASN). The findings suggest that restoring the process could protect the kidney health of obese individuals.

Obesity increases a chronic patient's risk of developing , but the mechanism underlying this connection has remained unclear.

Kosuke Yamahara, Takashi Uzu, MD, PhD (Shiga University of Medical Science, in Japan), and their colleagues suspected that decreased functioning of a process called autophagy might play a role. Autophagy is a degradation system within cells that removes damaged proteins and other defective cellular components, and autophagy insufficiency is common in obese individuals.

The researchers found that in normal-weight mice with kidney disease, autophagy was active in . However, in obese mice with kidney disease, autophagy was suppressed and kidney cells became damaged. Normal-weight mice with kidney disease and defective autophagy (due to a gene deletion) also experienced kidney cell damage.

The investigators also discovered that a potent suppressor of autophagy (called mTOR) was hyperactivated in the kidneys of obese mice, and treatment with an mTOR inhibitor ameliorated autophagy insufficiency. Furthermore, both mTOR hyperactivation and autophagy suppression were observed in kidney specimens from obese patients with kidney disease.

"Obesity suppresses autophagy via an abnormal activation of nutrition sensing signals in the kidney," said Yamahara. "Our results suggest that restoring the kidney-protective action of may improve the health of obese patients."

In an accompanying editorial, Ken Inoki, PhD (University of Michigan) stated that "the results of this study provide an important pathomechanism underlying obesity-associated renal… cell damage."

Explore further: Genetic variant linked with kidney failure in diabetic women but not men

More information: The article, entitled "Obesity-mediated Autophagy Insufficiency Exacerbates Proteinuria-induced Tubulointerstitial Lesions," will appear online on October 3, 2013, DOI: 10.1681/ASN.2012111080

The editorial, entitled "Proximal Tubules Forget 'Self-Eating' When They Meet Western Meals," will appear online on October 3, 2013, DOI: 10.1681/ASN.2013070794

Related Stories

Genetic variant linked with kidney failure in diabetic women but not men

September 12, 2013
A genetic variant on chromosome 2 is strongly linked with kidney failure in diabetic women but not in men, according to a study appearing in an upcoming issue of the Journal of the American Society of Nephrology (JASN). The ...

Obese kidney failure patients receive survival benefit from transplantation

July 25, 2013
Most obese individuals with kidney failure can prolong their lives by receiving a kidney transplant, although this survival benefit is lower in severely obese individuals. That's the conclusion of a new study published in ...

Key cellular auto-cleaning mechanism mediates the formation of plaques in Alzheimer's brain

October 3, 2013
Autophagy, a key cellular auto-cleaning mechanism, mediates the formation of amyloid beta plaques, one of the hallmarks of Alzheimer's disease. It might be a potential drug target for the treatment of the disease, concludes ...

Heart healthy lifestyle may cut kidney disease patients' risk of kidney failure

May 23, 2013
Maintaining a heart healthy lifestyle may also help protect chronic kidney disease patients from developing kidney failure and dying prematurely, according to a study appearing in an upcoming issue of the Journal of the American ...

Specific inhibition of autophagy may represent a new concept for treatment of kidney cancer

April 16, 2012
New research at the University of Cincinnati (UC) suggests that kidney cancer growth depends on autophagy, a complex process that can provide cells with nutrients from intracellular sources. Researchers say in certain circumstances ...

Chronic kidney disease a recipe for kidney failure? Not necessarily

March 8, 2012
Not all patients with chronic kidney disease (CKD) are destined for kidney failure, according to a study appearing in an upcoming issue of the Journal of the American Society Nephrology (JASN). The findings provide hope that ...

Recommended for you

Creation of synthetic horsepox virus could lead to more effective smallpox vaccine

January 19, 2018
UAlberta researchers created a new synthetic virus that could lead to the development of a more effective vaccine against smallpox. The discovery demonstrates how techniques based on the use of synthetic DNA can be used to ...

Study ends debate over role of steroids in treating septic shock

January 19, 2018
The results from the largest ever study of septic shock could improve treatment for critically ill patients and save health systems worldwide hundreds of millions of dollars each year.

New approach could help curtail hospitalizations due to influenza infection

January 18, 2018
More than 700,000 Americans were hospitalized due to illnesses associated with the seasonal flu during the 2014-15 flu season, according to federal estimates. A radical new approach to vaccine development at UCLA may help ...

Zika virus damages placenta, which may explain malformed babies

January 18, 2018
Though the Zika virus is widely known for a recent outbreak that caused children to be born with microencephaly, or having a small head, and other malformations, scientists have struggled to explain how the virus affects ...

Certain flu virus mutations may compensate for fitness costs of other mutations

January 18, 2018
Seasonal flu viruses continually undergo mutations that help them evade the human immune system, but some of these mutations can reduce a virus's potency. According to new research published in PLOS Pathogens, certain mutations ...

Study reveals how MRSA infection compromises lymphatic function

January 17, 2018
Infections of the skin or other soft tissues with the hard-to-treat MRSA (methicillin-resistant Staphylococcus aureus) bacteria appear to permanently compromise the lymphatic system, which is crucial to immune system function. ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.