Tag: auranofin

Arthritis Drug Auranofin may Improve Diabetes Symptoms

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Researchers have found that rheumatoid arthritis drug auranofin can potentially be repurposed to improve diabetes-associated symptoms. The study, which used a mouse model, appeared in the journal Cell Metabolism.

Although clear links have been identified between inflammation in white adipose tissue and insulin resistance in humans and rodents, broad anti-inflammatory treatments lack durable clinical efficacy on diabetes. In the current study, the researchers delved deeper into this association between inflammation and diabetes by looking for existing drugs that might affect both conditions.

“We computationally screened a small-molecule dataset and identified auranofin, an FDA-approved drug that has been used to treat rheumatoid arthritis, a condition involving inflammation,” said first and co-corresponding author Dr Aaron R. Cox, instructor of medicine-endocrinology, diabetes and metabolism at Baylor. “Auranofin exerts anti-inflammatory properties, which many people suspected would be beneficial in obesity and diabetes; however, nothing was really known about how it might affect metabolism.”

The team evaluated the metabolic effects of auranofin in a mouse model of diabetes in which the animals consume a high-fat diet.

“We discovered that auranofin has anti-inflammatory and anti-diabetic effects that are independent from each other,” said co-corresponding author Dr Sean Hartig, associate professor at Baylor. “Auranofin improved insulin sensitivity, or the body’s ability to respond to insulin to keep blood sugar at healthy levels. The drug also normalised obesity-associated changes such as hyperinsulinaemia in the mouse model. In addition, we found that auranofin accumulation in white adipose tissue reduced inflammatory responses without altering body composition in obese mice.”

Looking into the mechanism of these metabolic changes, the team discovered that auranofin’s anti-diabetic effects involved reduction of leptin levels. Leptin is a hormone whose levels markedly increase in obesity, contributing to insulin resistance and diabetes. In addition, auranofin restored white adipose tissue’s ability to respond to catecholamines, which are signals that increase metabolic activities in adipose tissue, triggering the burning of lipids at a higher rate.

“These changes coupled together contribute to the overall improvement in insulin sensitivity of the mice, leading to blood glucose control, which is the ultimate goal of diabetes treatments,” Dr Cox said. “High levels of glucose in the blood are detrimental to many tissues in the body. Uncontrolled, diabetes can lead to organ failure.”

Source: Baylor College of Medicine

The Search for New Cancer Therapies Strikes Gold

Photo by Jingming Pan on Unsplash

The gold complex auranofin has traditionally been used for treating rheumatism but is also being evaluated as a one number of new cancer therapies. According to a study published in Redox Biology, molecules with the same inhibition effect have been discovered that have a more specific effect than auranofin and therefore may have greater potential as cancer therapies.

Auranofin (AF) is classed by the WHO (World Health Organization) as an anti-rheumatic agent and is an active component in the drug Ridaura. AF is also currently being assayed in a string of clinical trials as a possible cancer therapy. One reason for the researchers’ interest in AF is its ability to inhibit thioredoxin reductase (TrxR), a protein central to the thioredoxin system, which protects cells from oxidative stress in all mammals. 

However, TrxR also protects cancer cells, making cancer therapies less effective. Moreover, TrxR, which affects cellular growth and survival, is upregulated in certain forms of cancer.

“There’s a great deal of interest in the ability to inhibit the thioredoxin system in the treatment of cancer, but there’s a risk that healthy cells will also be damaged and killed,” says the study’s co-last author Elias Arnér, professor at the Department of Medical Biochemistry and Biophysics at Karolinska Institutet. “Our aim is for TrxR inhibitors to be as specific as possible.”

The researchers studied the effects of AF in mouse cancer cells (lung adenocarcinoma and melanoma) and compared them with other recently-developed TrxR-inhibiting molecules called TRi-1 and TRi-2 (thioredoxin reductase inhibitors 1 and 2). 

The study, which was based on new proteomic methods of analysing the entire set of proteins in cells, suggests that the TRi compounds are more specific in their effect than AF. The results show that AF causes very high levels of oxidative stress and has other effects that seem unrelated to the inhibition of TrxR. They also demonstrate that TRi-1 seems to be the most specific TrxR inhibitor so far.

“Our results can serve as an important blueprint for further studies of AF’s mechanism of action and side effects,” said the study’s other co-last author Roman Zubarev, professor at the Department of Medical Biochemistry and Biophysics, Karolinska Institutet. “Having now compared AF with the more specific molecules TRi-1 and TRi-2, we hope that our findings will contribute to the further development of TrxR inhibitors as anticancer drugs.”

Source: Karolinska Insitutet