A research study has actually connected a high-sugar diet to insulin resistance in the brain, impairing the removal of neuronal debris and possibly increasing the risk of neurodegenerative diseases such as Alzheimers.
High-sugar diet in fruit flies leads to insulin resistance in the brain and impairs cleanup of neuronal waste.
Scientists led by Mroj Alassaf at the Fred Hutchinson Cancer Research Center in the United States have actually found a link in between obesity and neurodegenerative conditions like Alzheimers disease. Utilizing the common fruit fly, the research shows that a high-sugar diet plan– a hallmark of weight problems– triggers insulin resistance in the brain, which in turn minimizes the capability to get rid of neuronal debris, hence increasing the danger of neurodegeneration. Published on November 7th in the open access journal PLOS Biology, the research study will affect therapies developed to minimize the risk of developing neurodegenerative illness.
Insulin Resistance and Neuronal Debris
Obesity is understood to be a risk element for neurodegenerative disorders like Alzheimers illness and Parkinsons disease, exactly how one leads to the other remains a secret. Having formerly shown that a high-sugar diet plan leads to insulin resistance in the peripheral organs of flies, the scientists now turned to their brains.
Sugar fly. Creative rendering created by DALL.E using the prompt “The drawing of the fruit fly Drosophila in a dark background in the design of Seurat.” The researchers fed fruit flies high-sugar diets and analyzed the result on brain function. Credit: Akhila Rajan
Ramifications for Neurodegenerative Disease Risk
Levels of the protein PI3k indicate just how much a cell has the ability to react to insulin. The researchers found that the high-sugar diet resulted in lowered PI3k levels in glial cells, suggesting insulin resistance. They likewise looked at the fly equivalent of microglia, called ensheathing glia, whose primary function is to get rid of neural debris, such as deteriorating axons. They observed that these glia had low levels of the protein Draper, suggesting impaired function.
More tests revealed that synthetic reduction of PI3k levels caused both insulin resistance and low Draper levels in ensheathing glia. They showed that after really destructive olfactory nerve cells, the ensheathing glia might not get rid of the deteriorating axons in the flies on the high-sugar diet because their Draper levels did not increase.
The authors include, “Using fruit flies, the authors establish that high-sugar diets activate insulin resistance in glia, disrupting their capability to clear neuronal particles. This study provides insight into how obesity-inducing diets possibly contribute to the increased threat of neurodegenerative disorders.”
Reference: “Diet-induced glial insulin resistance hinders the clearance of neuronal debris in Drosophila brain” by Mroj Alassaf and Akhila Rajan, 7 November 2023, PLOS Biology.DOI: 10.1371/ journal.pbio.3002359.
Funding: This work is possible due to grants granted to AR from the National Institute of General Medical Sciences (R35GM124593), the Brain Research structure (BRFSG-2022-09), and the 2023 McKnight Foundation Neurobiology Disorders Award. MA is supported by a postdoctoral fellowship from the Helen Hay Whitney Foundation. The funders had no function in research study design, data collection and analysis, decision to release, or preparation of the manuscript.
Utilizing the typical fruit fly, the research study reveals that a high-sugar diet– a trademark of weight problems– triggers insulin resistance in the brain, which in turn minimizes the capability to eliminate neuronal particles, therefore increasing the risk of neurodegeneration. Having actually formerly revealed that a high-sugar diet leads to insulin resistance in the peripheral organs of flies, the researchers now turned to their brains. The researchers fed fruit flies high-sugar diets and took a look at the impact on brain function. Levels of the protein PI3k suggest how much a cell is able to react to insulin. The researchers discovered that the high-sugar diet led to lowered PI3k levels in glial cells, suggesting insulin resistance.