Changes of Functional, Morphological, and Inflammatory Reactions in Spontaneous Peripheral Nerve Reinnervation after Thermal Injury

Abstract

In recent decades, the use of energy-based devices has substantially increased the incidence of iatrogenic thermal injury to nerves (cauterization, etc.). While recovery of the nerve after thermal injury is important, the changes in neural structure, function, and peripheral inflammatory reactions postinjury remain unclear. This study is aimed at demonstrating the changes mentioned above during the acute, subacute, and chronic stages of nerve reinnervation after thermal injury. Spontaneous reinnervation was evaluated, including the neural structures, nerve conduction abilities, and muscle regeneration. These effects vary depending on the severity of thermal injury (slight, moderate, and severe). Peripheral inflammatory reactions, as impediments to reinnervation, were found in significant numbers 3 days after thermal injury, exhibiting high expression of IL-1β and TNF-α, but low expression of IL-10. Our findings reveal the pathogenesis of peripheral nerve reinnervation after thermal injury, which will assist in selecting appropriate treatments in further research.

Role of Transforming Growth Factor Beta in Peripheral Nerve Regeneration: Cellular and Molecular Mechanisms

“…Neural repair is a complex biological process, including the clearance of myelin debris ( Rotshenker, 2011 ), the formation of bands of Büngner that provide physical guidance for regrowing axons ( Min et al, 2021 ), and the synthesis of neurotrophic factors, extracellular matrix (ECM) and cell-adhesion molecules ( Luo et al, 2012 ; Pereira et al, 2012 ; Carvalho et al, 2020 ). In addition, the activation of the neuronal intrinsic growth capacity ( Chandran et al, 2016 ), blood nerve barrier (BNB) permeability ( Mizisin and Weerasuriya, 2011 ) and the inflammation level of wound microenvironment ( Molnár et al, 2022 ; Yu et al, 2022 ) also affect the outcome of neural regeneration. Among the various types of cells that participate in the regenerative process, Schwann cells (SCs) and macrophages are considered to have the most prominent roles ( Chen et al, 2015c ; Jessen et al, 2015 ; Kubiak et al, 2020 ).…”