Effect of unacylated ghrelin on peripheral nerve regeneration

Ghrelin is a circulating peptide hormone released by enteroendocrine cells of the gastrointestinal tract as two forms, acylated and unacylated. Acylated ghrelin (AG) binds to the growth hormone secretagogue receptor 1a (GHSR1a), thus stimulating food intake, growth hormone release, and gastrointestinal motility. Conversely, unacylated GHR (UnAG), through binding to a yet unidentified receptor, protects the skeletal muscle from atrophy, stimulates muscle regeneration, and protects cardiomyocytes from ischemic damage. Recently, interest about ghrelin has raised also among neuroscientists because of its effect on the nervous system, especially the stimulation of neurogenesis in spinal cord, brain stem, and hippocampus. However, few information is still available about its effectiveness on peripheral nerve regeneration. To partially fill this gap, the aim of this study was to assess the effect of UnAG on peripheral nerve regeneration after median nerve crush injury and after nerve transection immediately repaired by means of an end-to-end suture. To this end, we exploited FVB1 Myh6/Ghrl transgenic mice in which overexpression of the ghrelin gene (Ghrl) results in selective up-regulation of circulating UnAG levels, but not of AG. Regeneration was assessed by both functional evaluation (grasping test) and morphometrical analysis of regenerated myelinated axons. Results obtained lead to conclude that UnAG could have a role in development of peripheral nerves and during more severe lesions.

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Chitooligosaccharides promote peripheral nerve regeneration in a rabbit common peroneal nerve crush injury model

Microsurgery ◽

10.1002/micr.20686 ◽

2009 ◽

Vol 29 (8) ◽

pp. 650-656 ◽

Cited By ~ 23

Author(s):

Yanpei Gong ◽

Leilei Gong ◽

Xiaosong Gu ◽

Fei Ding

Keyword(s):

Peripheral Nerve ◽

Nerve Regeneration ◽

Peroneal Nerve ◽

Peripheral Nerve Regeneration ◽

Common Peroneal Nerve ◽

Crush Injury ◽

Nerve Crush ◽

Injury Model ◽

Nerve Crush Injury

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The Parameters of Transcutaneous Electrical Nerve Stimulation Are Critical to Its Regenerative Effects When Applied Just after a Sciatic Crush Lesion in Mice

BioMed Research International ◽

10.1155/2014/572949 ◽

2014 ◽

Vol 2014 ◽

pp. 1-8 ◽

Cited By ~ 10

Author(s):

Diana Cavalcante Miranda de Assis ◽

Êmyle Martins Lima ◽

Bruno Teixeira Goes ◽

João Zugaib Cavalcanti ◽

Alaí Barbosa Paixão ◽

...

Keyword(s):

Peripheral Nerve ◽

Nerve Regeneration ◽

Nerve Stimulation ◽

Transcutaneous Electrical Nerve Stimulation ◽

Peripheral Nerve Regeneration ◽

Light And Electron Microscopy ◽

Nerve Crush ◽

Electrical Nerve Stimulation ◽

The Right ◽

Crush Lesion

We investigated the effect of two frequencies of transcutaneous electrical nerve stimulation (TENS) applied immediately after lesion on peripheral nerve regeneration after a mouse sciatic crush injury. The animals were anesthetized and subjected to crushing of the right sciatic nerve and then separated into three groups: nontreated, Low-TENS (4 Hz), and High-TENS (100 Hz). The animals of Low- and High-TENS groups were stimulated for 2 h immediately after the surgical procedure, while the nontreated group was only positioned for the same period. After five weeks the animals were euthanized, and the nerves dissected bilaterally for histological and histomorphometric analysis. Histological assessment by light and electron microscopy showed that High-TENS and nontreated nerves had a similar profile, with extensive signs of degeneration. Conversely, Low-TENS led to increased regeneration, displaying histological aspects similar to control nerves. High-TENS also led to decreased density of fibers in the range of 6–12 μm diameter and decreased fiber diameter and myelin area in the range of 0–2 μm diameter. These findings suggest that High-TENS applied just after a peripheral nerve crush may be deleterious for regeneration, whereas Low-TENS may increase nerve regeneration capacity.

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