Heat delays skin wound healing in mice

Abstract

In vivo studies have shown that the combination of infrared radiation (IR) and visible light (VIS) is responsible for the activation of metaloproteinases, causing matrix degradation and damage to healthy skin. However, the role of heat originating from the VIS spectrum on wound healing remains poorly understood. Our objective was to investigate the macroscopic, microscopic and biochemical effects of heat induced by visible light on cutaneous wound healing in mice. Male mice were anesthetized, subjected to a cutaneous excisional wound and divided into two groups ( n = 10/group) exposed to 23℃ or 43℃ in a thermal chamber for 30 min every other day, for 13 days. On day 14, the animals were sacrificed, and their lesions were processed for histochemistry, immunohistochemistry and protein expression analysis. The wound area was 42% greater 11 days ( p < 0.01) and 29% greater 14 days ( p < 0.001) after wounding in the 43℃ group than in the 23℃ group. The 43℃ group presented a lower (17%) percentage of reepithelialized wounds ( p < 0.001) 14 days after wounding. The length of the epidermal gap was greater in the 43℃ group ( p < 0.01). The volume density of myofibroblasts and the number of F4/80-positive macrophages was greater in the 43℃ group ( p < 0.05). The 43℃ group showed increased protein expression of type III collagen ( p < 0.001), decreased protein expression of type I collagen ( p < 0.05), increased MMP-1 expression ( p < 0.05), and decreased MMP-2 activity ( p < 0.001). The protein expression of fibrillin-1 ( p < 0.001), MMP-12 ( p < 0.05), TGF-β 1/2/3 ( p < 0.01) and ERK activation ( p < 0.05) was increased in the 43℃ group. Our results suggest that heat delays the stages of wound healing in mice.

Presence of TRPV3 in macrophage lysosomes helps in skin wound healing against bacterial infection

“…Considering the core‐body temperature is roughly maintained at 37°C, the peripheral organs and skin have slightly less temperature, and the wounded/inflamed tissue has higher temperature, the effect of TRPV3 in skin‐wound healing can be more complex in vivo conditions. Our data also accords well with previous report demonstrating that mice exposed to 43°C daily for a brief time affects skin‐wound healing process 22 …”

“…Previous reports also suggest that mice maintained at 27°C, but exposed to 43°C for 30 min daily delays the wound healing process significantly 22 . In general, bacterial infection and/or LPS leads to inflammation and/or fever leading to an increase in temperature resulting in the hyper‐thermic condition.…”

“…significantly. 22 In general, bacterial infection and/or LPS leads to inflammation and/or fever leading to an increase in temperature resulting in the hyper-thermic condition. Therefore, we explored the status of TRPV3 in the lysosome in hyper-thermic shock conditions.…”

Microcurrent Stimulation Triggers MAPK Signaling and TGF-β1 Release in Fibroblast and Osteoblast-Like Cell Lines

“…It is worth mentioning that during the exposure to microcurrents, the temperature of the culture medium was monitored and was found to be constantly stable. Thus, we excluded the possibility that the WMCS device generates heat, which could delay the wound healing process by reducing the re-epithelialized area [ 52 ]. As a result, the effect of microcurrents is not affected by the heat.…”

Μελέτη Της Επίδρασης Μικρορευμάτων Σε Κυτταρικούς Πληθυσμούς

“…Συγκεκριμένα, κατά τη φάση της φλεγμονής τα μακροφάγα εκκρίνουν TGF-β, ο οποίος προσελκύει στην περιοχή του έλκους τους ινοβλάστες προκειμένου να ξεκινήσει η επόμενη φάση, όμως, σε υψηλές θερμοκρασίες ο αριθμός των μακροφάγων αυξάνεται συνεχώς, οδηγώντας σε μία παρατεταμένη φλεγμονώδη φάση. Επίσης, κατά τη φάση της ανάπλασης όταν υπάρχει υψηλή θερμοκρασία αυξάνεται ο αριθμός των μυοϊνοβλαστών και των μακροφάγων, ενώ υπό φυσιολογικές συνθήκες θα έπρεπε να μειώνεται και, ταυτόχρονα, αυξάνεται η ποσότητα του κολλαγόνου τύπου ΙΙΙ, το οποίο κανονικά σε αυτή τη φάση μειώνεται και αντικαθίσταται από το κολλαγόνο τύπου Ι (dos Santos-Silva et al 2017). Προκειμένου να αποκλείσουμε το ενδεχόμενο η συσκευή ασύρματης μικροηλεκτροδιέγερσης να προκαλεί αύξηση στη θερμοκρασία του θρεπτικού μέσου των κυττάρων, έγινε μέτρησή της καθ' όλη τη διάρκεια της επίδρασης και εμφανίστηκε σταθερή.…”