Monday, 13 February 2017

Back To The Zebra Fish: A Neuropathic Wonder! (Vid)

Today's video from (see link below) is so short (and silent) you might be forgiven for wondering why I bothered but it shows the remarkable ability of the zebra fish to regenerate its nerves when damaged. We're back to the ubiquitous zebra fish again - it pops up all over the neurology internet and has done for some time, as scientists try to discover why it does this and whether the science can somehow be applied to humans with damaged nerves. It's not for the want of trying as the article below shows. Let's hope they can eventually apply zebra fish self-healing to people living with neuropathy - now wouldn't that be something!!

Cool Videos: Regenerating Nerve Fibers
Posted on October 13, 2016 by Dr. Francis Collins

If you enjoy action movies, you can probably think of a superhero—maybe Wolverine?—who can lose a limb in battle, yet grow it right back and keep on going. But could regenerating a lost limb ever happen in real life? Some scientists are working hard to understand how other organisms do this. As shown in this video of a regenerating fish fin, biology can sometimes be stranger than fiction. The zebrafish (Danio rerio), which is a species of tropical freshwater fish that’s an increasingly popular model organism for biological research, is among the few vertebrates that can regrow body parts after they’ve been badly damaged or even lost. Using time-lapse photography over a period of about 12 hours, NIH grantee Sandra Rieger, now at MDI Biological Laboratory, Bar Harbor, ME, used a fluorescent marker (green) to track a nerve fiber spreading through the skin of a zebra fish tail fin (gray). The nerve regeneration was occurring in tissue being spontaneously formed to replace a section of a young zebra fish’s tail fin that had been lopped off 3 days earlier.

 Along with other tools, Rieger is using such imaging to explore how the processes of nerve regeneration and wound healing are coordinated. The researcher started out by using a laser to sever nerves in a zebrafish’s original tail fin, assuming that the nerves would regenerate—but they did not! So, she went back to the drawing board and discovered that if she also used the laser to damage some skin cells in the tail fin, the nerves regenerated. 

Rieger suspects the answer to the differing outcomes lies in the fact that the fish’s damaged skin cells release hydrogen peroxide, which may serve as a critical prompt for the regenerative process [1]. Rieger and colleagues went on discover that the opposite is also true: when they used a cancer chemotherapy drug to damage skin cells in a zebra fish tail fin, it contributed to the degeneration of the fin’s nerve fibers [2]. Based on these findings, Rieger wants to see whether similar processes may be going on in the hands and feet of cancer patients who struggle with painful nerve damage, called peripheral neuropathy, caused by certain chemotherapy drugs, including taxanes and platinum compounds. For some people, the pain and tingling can be so severe that doctors must postpone or even halt cancer treatment. 

Rieger is currently working with a collaborator to see if two protective molecules found in the zebra fish might be used to reduce or prevent chemotherapy-induced peripheral neuropathy in humans. In recent years, a great deal of regenerative medicine has focused on learning to use stem cell technologies to make different kinds of replacement tissue. Still, as Rieger’s work demonstrates, there remains much to be gained from studying model organisms, such as the zebra fish and axolotl salamander, that possess the natural ability to regenerate limbs, tissues, and even internal organs. Now, that’s a super power we’d all like to have. 

Reference: [1] Hydrogen peroxide promotes injury-induced peripheral sensory axon regeneration in the zebrafish skin. Rieger S, Sagasti A. PLoS Biol. 2011 May;9(5):e1000621 [2] Paclitaxel-induced epithelial damage and ectopic MMP-13 expression promotes neurotoxicity in zebra fish. Lisse TS, Middleton LJ, Pellegrini AD, Martin PB, Spaulding EL, Lopes O, Brochu EA, Carter EV, Waldron A, Rieger S. Proc Natl Acad Sci U S A. 2016 Apr 12;113(15):E2189-E2198. Links: Chemotherapy-Induced Peripheral Neuropathy (National Cancer Institute/NIH) Learning About Human Biology From a Fish (National Institute of General Medical Sciences/NIH) Sandra Rieger (MDI Biological Laboratory, Bar Harbor, ME) NIH Support: National Institute of Dental and Craniofacial Research; National Institute of General Medical Sciences; National Institute of Neurological Disorders and Stroke

No comments:

Post a Comment

All comments welcome but advertising your own service or product will unfortunately result in your comment not being published.