Unlocking the Metabolic Secrets of Grizzly Bears: A Pathway to Human Health Innovations.

At Washington State University (WSU), a team of scientists is exploring the remarkable physiological changes grizzly bears undergo during hibernation, with the goal of translating these findings into novel therapies for human metabolic diseases.​

Dr. Heiko Jansen, a professor at WSU's College of Veterinary Medicine, initially focused his research on seasonal reproductive cycles in sheep. However, a chance to study a grizzly bear's brain shifted his attention to the bear's unique hibernation physiology. Now, at the WSU Bear Research, Education, and Conservation Center, Jansen's team investigates how bears manage to gain significant fat before hibernation without developing the health issues commonly associated with obesity in humans.​

Grizzly bears experience a substantial drop in metabolic rate—about 75%—during hibernation. Despite this, they maintain stable blood glucose levels and avoid the complications of insulin resistance that humans often face. Intriguingly, bears become insulin resistant during hibernation but regain sensitivity upon waking. This reversible insulin resistance is of particular interest to researchers seeking to understand and treat human conditions like type 2 diabetes.​

In laboratory settings, Jansen's team cultured fat cells from hibernating bears and exposed them to serum from active-season bears. Remarkably, these cells regained insulin sensitivity, suggesting that certain circulating factors in the blood play a role in this metabolic switch. Identifying these factors could lead to breakthroughs in managing human insulin resistance.​

Compared to traditional rodent models, grizzly bears offer a closer parallel to human physiology. Unlike smaller hibernators that significantly lower their body temperatures, bears maintain temperatures closer to those of humans during hibernation. This similarity enhances the relevance of bear studies to human health.​

The WSU Bear Center houses 11 grizzly bears, providing researchers with ample opportunities to collect blood and tissue samples. The bears are trained to voluntarily participate in these procedures, often rewarded with honey. This cooperative behavior allows for the collection of adipose, liver, and muscle tissues under anesthesia, facilitating comprehensive studies without undue stress on the animals.​

To minimize invasive procedures, the research team cryopreserves preadipocytes and stores serum samples at ultra-cold temperatures. This approach enables the examination of cellular metabolism and gene expression across different seasons, offering insights into the bears' metabolic adaptations.​

One of the long-term objectives of this research is to identify the molecular mechanisms behind the bears' seasonal insulin sensitivity shifts. While current treatments for type 2 diabetes, such as GLP-1 analogs, have shown promise, understanding the bears' natural metabolic transitions could lead to alternative or complementary therapies.​

Additionally, the team has observed that hibernating bears maintain active circadian rhythms, despite the energy conservation typically associated with hibernation. This finding suggests that circadian cycles play a crucial role in the bears' metabolism and warrants further investigation.​

By unraveling the complexities of grizzly bear hibernation, researchers at WSU hope to pave the way for innovative treatments for metabolic disorders in humans, transforming our approach to diseases like obesity and type 2 diabetes.

Source:https://www.the-scientist.com/bear-necessities-insights-from-grizzly-bears-72944

This is non-financial/medical advice and made using AI so could be wrong.