New Drug Protects Mitochondria and Prevents Kidney Injury in Mice
New Drug Protects Mitochondria and Prevents Kidney Injury in Mice
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Sophia Friesen
Manager, Research Communications, 麻豆学生精品版
Email: sophia.friesen@hsc.utah.edu
Serious damage to short-term kidney function鈥攌nown as acute kidney injury, or AKI鈥攃an be fatal and also increase the risk of irreversible chronic kidney disease. It can be triggered by stressors ranging from sepsis to heart surgery, and it affects more than half of ICU patients. There are currently no drugs to treat AKI.
Now, researchers at 麻豆学生精品版 (U of U Health) have found that AKI is triggered by fatty molecules called ceramides, which cause serious injury by damaging kidney mitochondria. Using a backup drug candidate that changes ceramide metabolism, the team was able to preserve mitochondrial integrity and prevent kidney injury in mice.
鈥淲e completely reversed the pathology of acute kidney injury by inactivating ceramides,鈥 says distinguished professor and Chair of the Department of Nutrition and Integrative Physiology in the University of Utah College of Health and senior author on a paper describing the results. 鈥淲e were stunned鈥攏ot only did kidney function stay normal, but the mitochondria were unscathed,鈥 Summers says. 鈥淚t was truly remarkable.鈥
Key points:
- Acute kidney injury (AKI) is a serious and common reaction to many severe health stressors, including heart surgery.
- New research in mice found that molecules called ceramides trigger AKI by damaging mitochondria.
- A ceramide-lowering drug protected mitochondria and prevented AKI in mice.
IMPACT: If the drug works in people, it could prevent kidney injury in high-risk populations, or potentially even treat other diseases that affect mitochondria, like heart failure and diabetes.
An early warning sign for kidney injury
The Summers lab had previously shown that ceramides can damage tissues ranging from heart to liver. When the team profiled ceramides in models of AKI, the correlation was striking: ceramide levels spiked sharply after kidney injury in both mice and human urine samples.
鈥淐eramide levels are very elevated in kidney injury,鈥 says first author on the study, who did the research as a graduate student in nutrition and integrative physiology at U of U Health and is now a postdoctoral fellow at the Arc Institute. 鈥淭hey go up quickly after damage to the kidneys, and they go up in relation to the severity of the injury. The worse the kidney injury is, the higher the ceramide levels will be.鈥
These findings suggest that urinary ceramide levels could serve as an early biomarker for AKI, helping doctors identify patients at risk鈥攕uch as those undergoing heart surgery鈥攂efore symptoms appear. 鈥淚f patients are undergoing a procedure that we know puts them at high risk of AKI, then we can better predict whether or not they're actually going to have one,鈥 Nicholson says.
Modifying ceramides prevents kidney injury
The researchers were able to almost completely prevent kidney injury in an animal model by changing how ceramides are made. By making a precise genetic change that affects ceramide production, the team created 鈥渟uper mice鈥 that don鈥檛 get AKI, even in conditions that would otherwise trigger it.
Similarly, pre-treating mice with a new ceramide-lowering drug candidate developed by Centaurus Therapeutics, a company co-founded by Summers, prevented kidney injury. Kidney function improved, mice stayed fully active, and the kidneys looked nearly normal under the microscope. The model the researchers use tends to put the kidneys under a lot of stress, Nicholson says, so 鈥渋t鈥檚 really remarkable that mice were protected from the injury.鈥
鈥淭hese mice looked incredible,鈥 Summers adds.
Ceramides cause kidney injury by damaging mitochondria, the part of the cell that produces energy, the researchers found. Mitochondria in injured kidney cells are visibly malformed under a microscope, and they can鈥檛 produce energy as efficiently. Tweaking how ceramides are made, either genetically or with the drug, kept mitochondria healthy and functional even under stress.
Hope for acute kidney injury and other diseases
Summers emphasizes that the compound used in the study is closely related to, but not the same as, the ceramide-lowering drug that has advanced into human clinical testing. Results in mice don鈥檛 always translate directly to humans, he notes, and additional studies are needed to establish safety.
鈥淲e鈥檙e thrilled by how protective this backup compound was, but it鈥檚 still preclinical,鈥 Summers says. 鈥淲e need to be cautious and do our due diligence to make sure this approach is truly safe before moving it into patients.鈥
But the researchers are optimistic. If the results hold true in humans, the researchers hope that the drug could be provided in advance to people at high risk of acute kidney injury鈥攕uch as people undergoing heart surgery, about a quarter of whom experience AKI.
Because the drug seems to work by keeping mitochondria healthy, the researchers suspect that it might help treat or prevent many other diseases that affect mitochondria.
鈥淢itochondrial problems show up in so many diseases鈥攈eart failure, diabetes, fatty liver disease,鈥 Summers says. 鈥淪o if we can truly restore mitochondrial health, the implications could be enormous.鈥
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The results are published in Cell Metabolism as 鈥溾
The work was supported by a NCRR Shared Instrument Grant, the Kidney Precision Medicine Project, the National Institutes of Health, including the National Cancer Institute (grants P30CA042014, CA272529), the National Institute of Diabetes and Digestive and Kidney Diseases (grants DK115824, DK116888, DK116450, DK130296, DK108833, DK112826, 1F31DK134088 and 5T32DK091317), the National Institute of General Medical Sciences (grants 3R35GM131854 and 3R35GM131854-04S1), the Juvenile Diabetes Research Foundation (JDRF 3-SRA-2019-768-A-B and JDRF 3-SRA-2019-768-A-B to WLH), the Burroughs Wellcome Fund for Postdoctoral Diversity Enrichment Program (1058616), the American Diabetes Association, the American Heart Association, the Margolis Foundation, and the University of Utah Diabetes and Metabolism Research Center. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
Scott Summers and Jeremy Blitzer are co-founders and shareholders of Centaurus Therapeutics. Liping Wang is a shareholder of Centaurus Therapeutics. DN and Blitzer are listed as inventors on US Patents 1177684, 11597715, and 11135207 licensed to Centaurus Therapeutics, Inc.