Morphological changes of neural and vascular peptides in human skin suction blister injury

Abstract

Suction blister injury is an experimental model for the investigation of the possible derangement of dermal/epidermal interaction in injury. An extensive fibre network can be stained in skin using antisera to the pan-neuronal marker protein gene product 9.5 (PGP) and the sensory neuropeptide calcitonin gene-related peptide (CGRP), while microvessels are identifiable with antisera to the endothelial marker von Willebrand's factor (vWf) and the peptide endothelin (ET). To investigate the possible involvement of superficial cutaneous innervation and microcirculation during the repair process in injury, human skin biopsies taken at different times after suction blister injury were investigated by quantitative immunohistochemistry. Neural and endothelial changes were seen in both edge and blister areas. PGP- and CGRP-immunoreactive nerves showed an increase in both areas compared with control skin up to 6 h after injury, followed by a decrease which lasted until 72 h. This was followed by a gradual increase of both nerve types starting from the blister edge and lasting up to 8 days after injury when the values were similar to controls. Similarly, in the blister area of the skin, vWF-immunoreactive capillaries showed statistically significant increases between 0 and 6 h after injury, followed by a decrease at 12 and 18 h which was maintained up to 72 h. ET-1 immunoreactivity showed a similar, although more variable, pattern of changes. At the blister edge from 23 h onwards, both vWf and ET-1 immunoreactivities showed a second increase from the edge of the blister spreading towards the centre of the blister ahead of the nerve increase. This lasted up to 8 days, when vWf immunoreactivity showed a statistically significant increase compared with control skin. Generally the numerical increase observed at early time points was accompanied by a strong staining intensity, which reverted to a normal staining intensity at later time points. These results suggest that there is a reactive process for all immunoreactive elements in the early stages of injury, followed by changes indicative of neuronal and endothelial damage (depletion phase) and the subsequent repair process. The repair started with re-epidermalization from the blister edge, followed by revascularization and, lastly, by reinnervation of the tissue. These results indicate a close relationship between epidermis, blood vessels, and nerve fibres during the healing process which follows suction blister injury.

Interstitial Fluid and Lymph Formation and Transport: Physiological Regulation and Roles in Inflammation and Cancer

“…Clearly, the negative pressure will create hyperfiltration, and the blister formation induces an inflammatory reaction evidenced by high levels of the proinflammatory cytokines IL-6, IL-8, and RANTES in control blister fluid (537); release of neural and vascular peptides in human skin (162); and increased migration of Langerhans cells from epidermis (108), elements that will all contribute to increased protein permeability. There are hence factors that may influence the blister fluid protein concentration in opposite directions and moreover its composition, e.g., with respect to mediators, and it is doubtful whether samples will be representative for IF at least regarding composition of proteins.…”

A skin blister method to study epidermal nerves in peripheral nerve disease

“…Calcitonin gene-related peptide (CGRP) and substance P (SP) -ir fibers are only rarely observed in epidermis in biopsies of nonglabrous skin, 10,11,20 although Hosoi et al 9 described CGRP-ir nerves that were closely associated with Langerhans cells. Gu et al 7 used the superficial wound created by a blister to study changes in dermal nerves and blood vessels, but they did not describe or illustrate nerves in the blister. We showed the usefulness of the skin blister method for studying ENF reinnervation of a superficial skin wound 12 and the degenerative effects of topical 21 and intradermal capsaicin 24 on cutaneous nerves.…”

“…18 This results in disruption of hemidesmosomes and anchoring filaments that attach basal keratinocytes to the dermal-epidermal basement membrane and dermis. epidermis and basement membrane 2,3 and reactivity of dermal nerves and blood vessels have been described, 7 but there was no information on the fate of epidermal nerves. We observed that the distal segments of ENFs remain in the roof of the blister, separated from their proximal origins at the point where they penetrate basement membrane.…”

Plasma proteins in a standardised skin mini-erosion (I): permeability changes as a function of time

“…Studies using the laser Doppler technique to assess local superficial blood flow during the formation of an erosion have shown low values indicating a decreased blood flow, then a transient early increased blood flow 10–15 min after applying suction; this is followed by a hyperemic reaction initiated when the epidermal vesicle is formed and continuing unaltered after the end of the suction stimulus [5]. The hyperemic reaction is believed to be induced by a neurogenic inflammation triggered by the detachment of the epidermis with its thin, non-sensory nerve branches [4,5]. In neurogenic inflammation, peptides such as histamine, serotonine and bradykinine induce endothelial cell contraction producing endothelial cell gaps leading to increased permeability [21,22].…”