Effects of 4-methylcatechol on skin reinnervation: promotion of cutaneous nerve regeneration after crush injury.
We assessed the effects of treatment with 4-methylcatechol (4MC), a known inducer of nerve growth factor, on peripheral nerve regeneration by analyzing cutaneous and muscular reinnervation in mice after sciatic nerve crush injury. At 3 months postinjury, the skin innervation index was significantly higher in the 4MC group than the control group (p=0.0002); there was also increased unmyelinated fiber density (p=0.0042) and unmyelinated fibers/Remak bundle (p = 0.001) in sural nerves, indicating unmyelinated nerve fiber regeneration. These changes were accompanied by increases of transcripts for nerve growth factor (p = 0.0026) and glial cell line-derived neurotrophic factor (p=0.03) in the 4MC group. In contrast, muscle innervation indices were similar in both groups and were higher than the skin innervation index (p < 0.0001). The regeneration of myelinated nerve fibers, as assessed by fiber density, diameter and g ratio analyses in sural nerves, and amplitudes of muscle action potential in sciatic nerves, was similar in both groups. Taken together, these data suggest that 4MC specifically promoted the regeneration of unmyelinated nerve fibers and reinnervation of the skin by increasing the expression of nerve growth factor and glial cell line-derived neurotrophic factor.
Hsieh
Yu-Lin
YL
Department of Anatomy and Cell Biology, College of Medicine, National Taiwan University, Taipei, Taiwan.
Lin
Whei-Min
WM
Lue
June-Horng
JH
Chang
Ming-Fong
MF
Hsieh
Sung-Tsang
ST
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D002396:Catechols / Q000494:pharmacology*; D015870:Gene Expression / Q000187:drug effects; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D046529:Microscopy, Electron, Transmission; D018482:Muscle, Skeletal / Q000187:drug effects / Q000294:innervation*; D009409:Nerve Crush; D009413:Nerve Fibers, Myelinated / Q000187:drug effects / Q000648:ultrastructure; D036421:Nerve Fibers, Unmyelinated / Q000187:drug effects / Q000648:ultrastructure; D020932:Nerve Growth Factor / Q000096:biosynthesis / Q000187:drug effects; D009416:Nerve Regeneration / Q000187:drug effects*; D009431:Neural Conduction; D009469:Neuromuscular Junction / Q000187:drug effects / Q000648:ultrastructure; D018696:Neuroprotective Agents / Q000494:pharmacology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012584:Sciatic Nerve / Q000293:injuries; D012867:Skin / Q000187:drug effects / Q000294:innervation*
D002396:Catechols; D018696:Neuroprotective Agents; C018599:4-methylcatechol; D020932:Nerve Growth Factor