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 kidney disease patient's risk of developing kidney failure, 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 kidney cells. 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 autophagy may improve the kidney 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."
HighlightsUnlike in normal-weight mice with kidney disease, a degradation process called autophagy is suppressed in obese mice with kidney disease. This suppression leads to kidney cell damage.
Obese kidney disease patients also have suppressed autophagy.
Study co-authors include Shinji Kume, Daisuke Koya, Yuki Tanaka, Yoshikata Morita, Masami Chin-Kanasaki, Hisazumi Araki, Keiji Isshiki, Shin-ichi Araki, Masakazu Haneda, Taiji Matsusaka, Atsunori Kashiwagi, and Hiroshi Maegawa.
Disclosures: The authors reported no financial disclosures.
The article, entitled "Obesity-mediated Autophagy Insufficiency Exacerbates Proteinuria-induced Tubulointerstitial Lesions," will appear online at http://jasn.asnjournals.org/ 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 at http://jasn.asnjournals.org/ on October 3, 2013, doi: 10.1681/ASN.2013070794.
The content of this article does not reflect the views or opinions of The American Society of Nephrology (ASN). Responsibility for the information and views expressed therein lies entirely with the author(s). ASN does not offer medical advice. All content in ASN publications is for informational purposes only, and is not intended to cover all possible uses, directions, precautions, drug interactions, or adverse effects. This content should not be used during a medical emergency or for the diagnosis or treatment of any medical condition. Please consult your doctor or other qualified health care provider if you have any questions about a medical condition, or before taking any drug, changing your diet or commencing or discontinuing any course of treatment. Do not ignore or delay obtaining professional medical advice because of information accessed through ASN. Call 911 or your doctor for all medical emergencies.
Founded in 1966, and with more than 14,000 members, the American Society of Nephrology (ASN) leads the fight against kidney disease by educating health professionals, sharing new knowledge, advancing research, and advocating the highest quality care for patients.
Tracy Hampton | EurekAlert!
NIH scientists describe potential antibody treatment for multidrug-resistant K. pneumoniae
14.03.2018 | NIH/National Institute of Allergy and Infectious Diseases
Researchers identify key step in viral replication
13.03.2018 | University of Pittsburgh Schools of the Health Sciences
In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.
Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...
Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.
They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...
A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...
For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.
In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...
Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...
19.03.2018 | Event News
16.03.2018 | Event News
13.03.2018 | Event News
21.03.2018 | Physics and Astronomy
21.03.2018 | Materials Sciences
21.03.2018 | Life Sciences