German scientists say the key to regenerating neurons in humans with conditions such as Alzheimer's disease may be found in zebrafish. Photo by geralt/Pixabay
DRESDEN, Germany, Oct. 19 (UPI) -- Manipulating immune responses may help patients with Alzheimer's disease recover from neurodegenerative damage, researchers in Germany say.
The study, which focused on the regenerative properties of zebrafish, was conducted by scientists at the German Center for Neurodegenerative Diseases. According to the authors, an examination of zebrafish may provide clues for how to develop drugs to reverse the neuronal damage associated with Alzheimer's disease. Their findings were published in the journal Cell Reports.
While investigators concede humans and zebrafish have obvious biological differences, the two species share important similarities.
"The regenerative skills apparent in zebrafish might lie dormant in humans and might somehow be activated by pulling the right strings," lead researcher Caghan Kizil said in a press release. "This is why we study if and how zebrafish cope with neurodegeneration. We want to understand the basic molecular mechanisms of such a regenerative aptitude in order to design better clinical therapies."
During the study, the research team mimicked the effects of Alzheimer's in a zebrafish brain using Amyloid-Beta42 deposits, one of the contributors to the human condition. The deposits triggered an inflammation-related pathway resulting in the creation of new neurons.
"We found that a molecule called Interleukin-4 is very much involved in the generation of neurons. The molecule is released by the dying neurons and immune system cells. It then acts on neural stem cells, which are the progenitors of neurons, by increasing their proliferation," Kizil said. "Interleukin-4 has been known to be a player in immune response and inflammation. But to date, the direct role of IL4 on stem cell proliferation has not been shown."
Kizil went on to explain that while the same course of action may not have the same results in humans, the behaviors demonstrated provide valuable insight.
"Our zebrafish model offers the opportunity to study such factors one by one in a reductionist manner," Kizil added. "Besides, our study points to the significance of the immune response. That is to say: by tweaking the immune response, for example with drugs, and targeting the right cell types, we might unlock the potential of human neural stem cells to proliferate and build new neurons."