[Research advances on inflammatory responses involved in keloid development]

Expression of macrophage activation‑specific factors in hyperplastic scar tissue during hyperplasia phase by antibody array blotting membrane assay and its clinical significance

The expression of macrophage activation-specific factors in hyperplastic scar (HS) tissues during hyperplasia phase was detected by antibody array imprinted membrane method and the role of macrophage activation in the natural evolution of HS was explored. A total of 83 patients with HS admitted to the Affiliated Hospital of Beihua University (Jilin, China) between February 2021 and July 2021 were enrolled. The clinical data of the patients were retrospectively analyzed. These patients were divided into the hyperplasia HS group (n=26) and the decline HS group (the HS tissues ceased to grow and were in regression periods; n=57) according to the time of scar formation and clinical characteristics. The HS tissues were collected from patients in both groups. The contents of IL-12, IL-10, VEGF and basic fibroblast growth factor (bFGF) were detected by antibody array imprinted membrane method and the contents of IL-12, IL-10, VEGF and bFGF in tissues with various groups of tissues and clinical features were compared. The connection between macrophage activation-specific factors with VEGF and bFGF was analyzed using Pearson correlation analysis. The contents of IL-10 (9.48±1.06), VEGF (24.15±2.64) and bFGF (37.48±2.56) were much lower and IL-12 levels (16.45±0.85) were strongly higher in hyperplasia HS group compared with those in the decline HS group (14.56±1.26 for IL-10, 27.85±2.63 for VEGF, 43.15±3.16 for bFGF and 10.46±0.75 for IL-12, P<0.001). In the hyperplasia HS group, the contents of IL-10, VEGF and bFGF were obviously higher and the IL-12 levels were markedly lower in patients with age ≥30 years, protuberance height <2 mm, soft flexibility, low hyperemia degree and no concomitant symptoms than those in the patients with age <30 years, protuberance height ≥2 mm, hard flexibility, high hyperemia degree and concomitant symptoms (P<0.001). Pearson correlation analysis showed that IL-12 was negatively correlated with VEGF and bFGF (r=-0.328, 0.600, P<0.01). IL-10 was positively correlated with VEGF and bFGF (r=0.486, 0.684, respectively, P<0.001). In conclusion, macrophage activation-specific factors were abnormally expressed in hyperplasia HS, mainly M1 macrophages, accompanied by severe inflammatory reaction. The transformation of M1 macrophage into M2 macrophage usually occurred during the declining HS phase, which accelerated scar formation by promoting the formation of fibroblasts and angiogenesis. Detection of macrophage activation-specific factors may contribute to evaluate the clinical stage of HS.

Effect of Mortalin on Scar Formation in Human Dermal Fibroblasts and a Rat Incisional Scar Model

Wound healing is a complicated cascading process; disequilibrium among reparative processes leads to the formation of pathologic scars. Herein, we explored the role of mortalin in scar formation and its association with the interleukin-1α receptor using in vitro and in vivo models. To investigate the effects of mortalin, we performed an MTT cell viability assay, qRT-PCR, and Western blot analyses, in addition to immunofluorescence and immunoprecipitation studies using cultured fibroblasts. A rat incisional wound model was used to evaluate the effect of a mortalin-specific shRNA (dE1-RGD/GFP/shMot) Ad vector in scar tissue. In vitro, the mortalin-treated human dermal fibroblast displayed a significant increase in proliferation of type I collagen, α-smooth muscle actin, transforming growth factor-β, phospho-Smad2/3-complex, and NF-κB levels. Immunofluorescence staining revealed markedly increased mortalin and interleukin-1α receptor protein in keloid tissue compared to those in normal tissue, suggesting that the association between mortalin and IL-1α receptor was responsible for the fibrogenic effect. In vivo, mortalin-specific shRNA-expressing Ad vectors significantly decreased the scar size and type-I-collagen, α-SMA, and phospho-Smad2/3-complex expression in rat incisional scar tissue. Thus, dE1-RGD/GEP/shMot can inhibit the TGF-β/α-SMA axis and NF-κB signal pathways in scar formation, and blocking endogenous mortalin could be a potential therapeutic target for keloids.