Inhibition of Proliferation, Migration, and Invasion of Keloid Fibroblasts By miR-183-5p Through Downregulating EGR1 / Inhibición de la Proliferación, Migración e Invasión de Fibroblastos Queloides por miR-183-5p Mediante la Regulación Negativa de EGR1

SUMMARY: Keloid scar is a unique benign fibroproliferative tumor of the human skin. Previously, it was reported that early growth response 1 (EGR1), a transcription factor, promotes keloid fibrosis; however, the mechanism by which EGR1 modulates keloid formation was not elaborated. In this research, the specific function and the microRNA (miRNA) regulatory network of EGR1 in keloids was examined. Keloid fibroblasts (KFs) were transfected with EGR1-small interfering RNA (siEGR1), EGR1-overexpression plasmid (pcDNA3.1-EGR1), and microRNA (miR-183-5p)-mimics to regulate the expression of EGR1 and miR-183-5p. The study employed dual-luciferase reporter assays to explore the targeting regulation of miR-183-5p on EGR1. Additionally, Western blotting, flow cytometry, qRT-PCR, cell count kit-8 (CCK-8), transwell, and wound healing assays, and RNA sequencing were conducted. EGR1 was upregulated in KFs, and EGR1 silencing diminished proliferation, fibrosis, migration, invasion, and apoptosis of cells. In KFs, the expression of miR- 183-5p was reduced, leading to the inhibition of cell proliferation, migration, and invasion. Conversely, it enhanced apoptosis. By targeting EGR1, miR-183-5p partially counteracted the impact of EGR1 on migration, invasion, and fibrosis in KFs. The findings imply that miR-183-5p suppresses keloid formation by targeting EGR1. As a result, EGR1 holds promise as a potential therapeutic target for preventing and treating keloids.

La cicatriz queloide es un tumor fibroproliferativo benigno único de la piel humana. Anteriormente, se informó que la respuesta de crecimiento temprano 1 (EGR1), un factor de transcripción, promueve la fibrosis queloide; sin embargo, no se explicó el mecanismo por el cual EGR1 modula la formación de queloides. En esta investigación, se examinó la función específica y la red reguladora de microARN (miARN) de EGR1 en queloides. Se transfectaron fibroblastos queloides (KF) con ARN de interferencia pequeño de EGR1 (siEGR1), plásmido de sobreexpresión de EGR1 (pcDNA3.1-EGR1) y miméticos de microARN (miR-183-5p) para regular la expresión de EGR1 y miR-183. -5p. El estudio empleó ensayos de indicador de luciferasa dual para explorar la regulación dirigida de miR-183-5p en EGR1. Además, se realizaron pruebas de transferencia Western, citometría de flujo, qRT-PCR, kit de recuento celular-8 (CCK-8), transwell y curación de heridas, y secuenciación de ARN. EGR1 estaba regulado positivamente en KF, y el silenciamiento de EGR1 disminuyó la proliferación, fibrosis, migración, invasión y apoptosis de las células. En KF, la expresión de miR- 183-5p se redujo, lo que llevó a la inhibición de la proliferación, migración e invasión celular. Por el contrario, mejoró la apoptosis. Al apuntar a EGR1, miR-183-5p contrarrestó parcialmente el impacto de EGR1 en la migración, invasión y fibrosis en KF. Los hallazgos implican que miR-183-5p suprime la formación de queloides al apuntar a EGR1. Como resultado, EGR1 es prometedor como objetivo terapéutico potencial para prevenir y tratar los queloides.

Low-Level Light Therapy with 410 nm Light Emitting Diode Suppresses Collagen Synthesis in Human Keloid Fibroblasts: An In Vitro Study

BACKGROUND: Keloids are characterized by excessive collagen deposition in the dermis, in which transforming growth factor β (TGF-β)/Smad signaling plays an important role. Low-level light therapy (LLLT) is reported as effective in preventing keloids in clinical reports, recently. To date, studies investigating the effect of LLLT on keloid fibroblasts are extremely rare. OBJECTIVE: We investigated the effect of LLLT with blue (410 nm), red (630 nm), and infrared (830 nm) light on the collagen synthesis in keloid fibroblasts. METHODS: Keloid fibroblasts were isolated from keloid-revision surgery samples and irradiated using 410-, 630-, 830-nm light emitting diode twice, with a 24-hour interval at 10 J/cm². After irradiation, cells were incubated for 24 and 48 hours and real-time quantitative reverse transcription polymerase chain reaction was performed. Western blot analysis was also performed in 48 hours after last irradiation. The genes and proteins of collagen type I, TGF-β1, Smad3, and Smad7 were analyzed. RESULTS: We observed no statistically significant change in the viability of keloid fibroblasts after irradiation. Collagen type I was the only gene whose expression significantly decreased after irradiation at 410 nm when compared to the non-irradiated control. Western blot analysis showed that LLLT at 410 nm lowered the protein levels of collagen type I compared to the control. CONCLUSION: LLLT at 410 nm decreased the expression of collagen type I in keloid fibroblasts and might be effective in preventing keloid formation in their initial stage.

Expression of nerve growth factor p75 receptor and sortilin in the skin fibroblasts and scar fibroblasts / 中国组织工程研究

BACKGROUND: Previous studies have found that nerve growth factors play an important role in the process of wound healing, but there is less research for the low-affinity nerve growth factor receptor p75 and sortilin in fibroblasts, and no reports on whether there are differences in expression of p75 and sortilin in the scar fibroblasts and normal skin fibroblasts. OBJECTIVE: To study the expression of low-affility nerve growth factor receptor p75 and sortilin in the normal human skin fibroblasts and the human keloid fibroblasts. METHODS: The keloid fibroblasts and normal hunman skin fibroblasts were cultured in vitro, and the immortalized epithelial cells HaCaT were used as the positive control. The real-time PCR was used to detect the mRNA expression of the p75 and sortilin in the keloid fibroblasts and normal human skin fibroblasts, and western blot and immunocytochemical staining were used to detect the protein expression of p75 and sortilin. RESULTS AND CONCLUSION: The real-time PCR and western blot results showed that in the protein and mRNA levels, p75 and sortilin showed positive expression in the keloid fibroblasts and normal human skin fibroblasts, and there was no significant difference in the expression of p75 between keloid fibroblasts and normal human skin fibroblasts, and the expressions of p75 and sortilin in the keloid fibroblasts and normal human skin fibroblasts were significantly lower than those in HaCaT. There was no significant difference of p75 expression between keloid fibroblasts and normal human skin fibroblasts, and the expression of sortilin in the keloid fibroblasts was significantly lower than that in the normal human skin fibroblasts (P < 0.05). Immunocytochemical staining result showed that the expression of p75 and sortilin in the keloid fibroblasts and normal human skin fibroblasts were distributed in the membrane and cytoplasm. Precursor nerve growth factor combined with high-affinity p75 receptor could promote the apoptosis of the cells with the help of sortilin, and the expression of sortilin in the keloid fibroblasts was significantly lower than that in the normal human skin fibroblasts, which may associated with the high proliferation of the keloid fibroblasts. The results provide a new target for the prevention and treatment of pathological scars.

Effects of Hepatocyte Growth Factor on Collagen Synthesis and Matrix Metalloproteinase Production in Keloids

Keloids are pathologic proliferations of the dermal layer of the skin resulting from excessive collagen production and deposition. Hepatocyte growth factor (HGF) increases the expression of matrix metalloproteinase (MMP)-1 and suppresses collagen synthesis to modulate extracellular matrix turnover. To investigate the anti-fibrotic effects of HGF, we examine the mRNA expression of collagen types I and III and matrix metalloproteinase (MMP-1, MMP-3) on human dermal fibroblast (HDF) cell lines and keloid fibroblasts (KFs, n = 5) after adding various amount of HGF protein. We also evaluated the enzymatic activity of MMP-2, MMP-9 by zymograghy. In HDFs treated with TGF-beta1 and HGF protein simultaneously, both type I and III collagen mRNA expression significantly decreased (P < 0.05). Expression of MMP-1, MMP-3 mRNA also decreased. However, the mRNA expression of MMP-1, MMP-3 significantly increased in KFs with increasing amount of HGF in dose dependent manner (P < 0.05). The enzymatic activities of MMP-2 increased with increasing HGF protein in a dose-dependent manner. However, the enzymatic activity of MMP-9 did not change. These results suggest that the anti-fibrotic effects of HGF may have therapeutic effects on keloids by reversing pathologic fibrosis.

Effect of carboxymethyl-chitosan on proliferation and collagen synthesis in keloid fibroblasts in vitro / 中华医学美学美容杂志

Objective To investigate the effects of carboxymethyl-chitosan (CM-CH) on keloid fibroblasts (KFB) proliferation and collagen synthesis. Methods Keloid fibroblasts were isolated from fresh keloid tissue and cultured. The effect of CM-CH on proliferation was examined by MTT assay. The synthesis of collagen was evaluated by hydroxy proline (HP) colorimetric analysis. Results The fibroblasts were treated with CM-CH at concentration of 10 ?g/ml, 50 ?g/ml, and 100 ?g/ml 48h and 72h after treatment, and all of the three concentrations showed inhibitory effects significantly (P0.05) at 200 ?g/ml concentration after 24h, 48h, and 72h. CM-CH at concentration of 10 ?g/ml, 50 ?g/ml, and 100 ?g/ml after treatment for 48h on KFB could markedly decrease the synthesis of collagen (P