Peptide Associated with Alzheimer's Disease May Also Impact Diabetes

July 24, 2009

When humanin was injected into the brains of diabetic rats, “the infused humanin significantly improved overall insulin sensitivity, both in the liver and in skeletal muscle,” according to the researchers.

A peptide found in mitochondria that may protect nerve cells against death associated with Alzheimer’s and other brain disease may also be beneficial for diabetes, new research from the Albert Einstein College of Medicine at Yeshiva University shows.

When humanin was injected into the brains of diabetic rats, “the infused humanin significantly improved overall insulin sensitivity, both in the liver and in skeletal muscle,” according to the researchers. In addition, it only took one treatment with a “highly potent form” of the peptide to see a significantly lower level of blood sugar.

"This new role of humanin in glucose metabolism, in addition to its role in Alzheimer's disease, is very intriguing since scientists have long proposed a link between type 2 diabetes and Alzheimer's disease," said Nir Barzilai, M.D., a co-senior author of the study, the Ingeborg and Ira Leon Rennert Professor of Aging Research, and director of the Institute for Aging Research at Einstein. "Humanin could turn out to be a therapeutic option for two common debilitating diseases that affect millions of people.”

Because the peptide has been linked to two age-related diseases, the researchers were prompted to examine whether or not levels of humanin are related to changes in age in both humans and rats. As a result, they found that levels of humanin in the hypothalamus, the cortex, and skeletal muscle decreased in rodents as they aged, and that levels of the peptide in circulating blood decreased in people as they aged.

The researchers are now studying “the pharmacokinetics and safety profile of humanin and its analogues.”

"The remarkable activity of this novel peptide proposes a new role for an emerging class of endogenous molecules derived from the mitochondria that have previously been overlooked and can potentially represent a different paradigm for drug development for a variety of diseases," said Dr. Pinchas Cohen, co-senior author, professor and chief of endocrinology at the Mattel Children's Hospital UCLA, and co-director of the UCSD/UCLA Diabetes/Endocrinology Research Center at the David Geffen School of Medicine at UCLA.

Findings of the study were also published in PLoS One

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