Ascorbic acid provides a favorable microenvironment for peripheral nerve regeneration

Guo Jiasong's team from Southern Medical University in China found that ascorbic acid (vitamin C) can accelerate the degeneration of axons and myelin sheaths in damaged nerves through in vivo sciatic nerve transection model and in vitro nerve explantation block culture, promote the decentralization of Xuwang cells, enhance the recruitment of macrophages and their phagocytic ability, and thus accelerate the degeneration of Wallerian.

Peripheral nerve injury is a common clinical disease, and its harm is enormous. Although the peripheral nervous system has a certain regenerative ability, its regeneration rate is slow, and the function recovery effect is not ideal, so accelerated nerve regeneration has become a hot topic in today's research. Guo Jiasong and other previous studies have found that the commonly used clinical drug ascorbic acid has the effect of promoting the regeneration of peripheral nerves, and partially explains the mechanism from neurons, Xuwang cells and macrophages. Wallerian degeneration is an inevitable axonal and myelin ulceration that occurs distal to peripheral nerve injury, in which Xuwang cells and macrophages play a vital role. Accelerating Wallerian denaturation helps to provide a favorable microenvironment for nerve regeneration and is an effective strategy for promoting nerve regeneration, so this study aims to explore whether ascorbic acid can accelerate Valleyrian degeneration and explore related mechanisms.

Guo Jiasong et al. found that ascorbic acid can significantly promote the degradation of myelin alkaline protein-positive myelin and nerve filament 200 axons in transverse nerve and nerve explant blocks, while inhibiting the expression of MAG, c-Jun expression, and increasing the number of myelin fragments in macrophages and macrophages. Suggests that ascorbic acid accelerates the degeneration of axons and myelin sheaths in damaged nerves, promotes the dedifferentiation of Xuwang cells, and enhances macrophage recruitment and its phagocytic ability, thereby accelerating Wallerian degeneration. It is shown that ascorbic acid can accelerate the degeneration of the damaged nerves by Varyrian, which provides a good microenvironment for promoting the regeneration and repair of damaged nerves to the distal end. This will provide a new theoretical basis for the application of ascorbic acid to peripheral nerve damage repair.

The article based on the research results was published in the Journal of Chinese Neural Regeneration Research (English Edition) in Issue 6, 2021.

Article Summary: Wallerian degeneration that occurs after peripheral nerve injury helps to provide a favorable microenvironment for nerve regeneration. Previous studies by the authors have found that ascorbic acid may promote peripheral nerve regeneration by promoting the proliferation and phagocytosis of Xuwang cells, as well as enhancing the proliferation, migration and phagocytosis of macrophages. Since Xuwan cells and macrophages are the main cells involved in Valleyian degeneration, measuring ascorbic acid can accelerate Wallerian degeneration. To test this hypothesis, the experiment was performed to fill the rat with 400 mg/kg ascorbic acid immediately after the sciatic nerve was transverse, followed by 200 mg/kg per day, and the rat sciatic nerve explant was intervened with 200 μM ascorbic acid. The results showed that ascorbic acid could significantly promote the degradation of myelin alkaline protein-positive myelin and nerve filament 200 axons in transverse nerve and nerve explant blocks, and at the same time inhibit the expression of MAG, c-jun expression, and increase the number of myelin fragments in macrophages and macrophages. Suggests that ascorbic acid accelerates the degeneration of axons and myelin sheaths in damaged nerves, promotes the dedifferentiation of Xuwang cells, and enhances macrophage recruitment and its phagocytic ability, thereby accelerating Wallerian degeneration. The experiment was approved by the Animal Ethics Committee of Southern Medical University on October 15, 2015, and the approval number: SMU-L2015081.

Article keywords: ascorbic acid; Wallerian degeneration; peripheral nerve damage; axon; myelin sheath; Xuwang cells; macrophages; phagocytosis; regeneration; microenvironment

文章来源：Li L, Xu Y, Wang X, Liu J, Hu X, Tan D, Li Z, Guo J (2021) Ascorbic acid accelerates Wallerian degeneration after peripheral nerve injury. Neural Regen Res 16(6):1078-1085.