Heat Shock-Induced Three-Dimensional-Like Proliferation of Normal Human Fibroblasts Mediated by Pressed Silk

Abstract

The aim of this study was to determine the optimal heat treatment conditions for enhancement of pressed silk-mediated 3D-like proliferation of normal human dermal fibroblasts, as well as to determine the responses to heat shock of cells and intracellular signaling pathways. The beginning of 3D-like pattern formation of cells was observed in the second week after the start of the experiment. The mean rates of beginning of 3D-like pattern formation by cells heat-treated at 40 ºC and 43 ºC for 10 min were significantly higher (3.2- and 8.6-fold, respectively) than that of untreated cells. We found that apoptosis had occurred in 7.5% and 50.0% of the cells at one week after heat treatment for 10 min at 43 ºC and 45 ºC, respectively. Western blot analysis demonstrated that phosphorylation of p38 MAPK and that of Hsp27 were markedly increased by heat treatment at 43 ºC for 10 min. The results of an experiment using a p38 MAPK inhibitor and Hsp27 inhibitor suggest that activation of p38 MAPK by heat shock is associated with 3D-like cell proliferation and that Hsp27 contributes to the inhibition of apoptosis. The results of this study should be useful for further studies aimed at elucidation of the physiologic mechanisms underlying thermotherapy.

Exogenous Local Hyperthermia at 41℃ Is Effective to Eliminate Mouse Model of Sporotrichosis, Independent of Neutrophil Extracellular Traps Formation

“…Mice that were exposed to 40℃ for 1 hour showed strongly reduced IL-8-induced neutrophilic skin inflammation 16 . Moreover, heat treatment can induce 3D-like cell proliferation of normal human fibroblast 17 , and improve wound healing 18 . In summary, these results indicate that hyperthermia functions by ameliorating the inflammation and promoting tissue repair.…”

Temporal Changes in Skin Temperature Caused by Wet and Dry Heat in Healthy Volunteers

“…Thermotherapy shows positive effects when an optimal heat treatment is applied. This suggests the importance of the excited state of water in inducting strong vasodilatation 25) . However, our results showed that body temperature was increased to a greater extent in males than in females following dry heat application.…”

Radiofrequency therapy in esthetic dermatology: A review of clinical evidences

“…37 The effects of heat for cellular apoptosis are prominent over a temperature range from 40°C to 55°C, with rupture around 43°C. 37 It is important to highlight that the electrodes should be moved on the surface of the skin during treatment to maintain the temperature in the target area. However, it is challenging to achieve uniform temperatures and keep them steady, what can limit the effectiveness of such dynamics.…”

“…During application, the power of the equipment can be regulated by back and forth movements, with the electrode pressed against the skin in small areas three times the size of the active electrode until the desired temperature is reached. 37 The effects of heat for cellular apoptosis are prominent over a temperature range from 40°C to 55°C, with rupture around 43°C. 37 It is important to highlight that the electrodes should be moved on the surface of the skin during treatment to maintain the temperature in the target area.…”

“…It is also known that the dosimetry of RFT in a nonablative form, for hyperthermia, a therapeutic range between 40°C and 45°C should be achieved. During application, the power of the equipment can be regulated by back and forth movements, with the electrode pressed against the skin in small areas three times the size of the active electrode until the desired temperature is reached . The effects of heat for cellular apoptosis are prominent over a temperature range from 40°C to 55°C, with rupture around 43°C .…”