OBJECTIVE: To review the research progress of the principle and clinical application of keloid core excision technique. METHODS: The literature on keloid core excision technique at home and abroad in recent years was extensively reviewed, and the principle, development history, indications, advantages and disadvantages of this technique were summarized, and the existing controversies were analyzed. RESULTS: Keloid core excision is a technique to remove the inner fibrous core from the keloid and cover the defect with the keloidal flap. It reduces the wound tension, yields good aesthetic results in the treatment of ear keloids, and reduces the recurrence rate of keloids combining with adjuvant therapies. CONCLUSION The keloid core excision technique has specific advantages, yet its overall efficacy remains controversial. Further studies are imperative to explore the mechanisms regarding keloid recurrence and the vascular supply principles of the keloidal flap. It is also necessary to define appropriate surgical indications and safety protocols of this technique.
Humans ; Keloid/pathology* ; Recurrence ; Surgical Flaps/pathology* ; Plastic Surgery Procedures ; Treatment Outcome

Objective: To compare the differences of water barrier function between keloids and its surrounding normal skin in patients with keloids, and to explore the primary mechanism. Methods: A cross-sectional observational study was conducted. From October 2020 to March 2021, 30 patients with keloids who met the inclusion criteria visited Shanghai Ninth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, including 18 females and 12 males, aged 20-48 years. The transepidermal water loss (TEWL) of their keloids and the surrounding normal skin of the 30 patients were measured by multi probe adapter on the reception day. The keloid tissues and normal skin of 5 patients after keloid repair surgery were processed for hematoxylin-eosin staining to measure the thickness of epidermis. Immunohistochemistry was performed on samples from 3 of those 5 patients to detect the expressions of cytokeratin-10, involucrin, and filaggrin in keloids and normal skin. Data were statistically analyzed with paired sample t test and independent sample t test. Results: On the reception day, the TEWL of keloids of 30 patients was 9.0 (6.9, 13.4) g·m^-2·h^-1 and the TEWL of the normal skin was 8.1 (6.4, 18.1) g·m^-2·h^-1, between which the difference was not statistically significant (t=0.44, P>0.05). After keloid repair surgery, the thickness of epidermis in the keloids of 5 patients was (194±44) μm, which was significantly thicker than that of the normal skin (44±11) μm, (t=6.88, P<0.01). Furthermore, increased keratinocytes, lack of normal epidermal ridge structures, and thickened stratum corneum were observed in the keloid area. After keloid repair surgery, the expression level of cytokeratin-10 in keloids was significantly lower than that in normal skin of 3 patients (t=8.50, P<0.01), but there were no statistically significant differences in the expression levels of involucrin or filaggrin between keloids and normal skin (with t values of 0.07 and 0.96, respectively, P>0.05). Conclusions: Keloid tissue from patients with keloids displays increased number of keratinocytes and thickened epidermis. But the water barrier function in keloid area is similar to the surrounding normal skin, suggesting that TEWL may not be the main mechanism lead to the persistent development of keloids.
Adult ; China ; Cross-Sectional Studies ; Female ; Humans ; Keloid/pathology* ; Male ; Middle Aged ; Skin/pathology* ; Water ; Young Adult

In re-cent 20 years, the development of cell biology technology has promoted the research of keloid. Keloid fibroblasts (KFbs) are the main effector cells in keloid, which are closely related to the occurrence and development of keloid. It is significantly different in terms of biological characteristics and gene expression between KFbs and normal fibroblasts. This articles reviews the characteristics of KFbs from multiple perspectives, describing its biological character- istics in details including microstructures, metabolic character- istics, and proliferation properties, and introducing the main characteristics of heterogeneity and genomics of KFbs. The further research on KFbs will help to elucidate the pathogenesis of keloids and provide valuable strategies for the prevention and treatment of keloids.
Fibroblasts/metabolism* ; Humans ; Keloid/pathology*

Keloids are a common type of pathological scar as a result of skin healing, which are extremely difficult to prevent and treat without recurrence. The pathological mechanism of keloids is the excessive proliferation of fibroblasts, which synthesize more extracellular matrices (ECMs), including type I/III collagen (COL-1/3), mucopolysaccharides, connective tissue growth factor (CTGF, also known as cellular communication network factor 2 (CCN2)), and fibronectin (FN) in scar tissue, mostly through the abnormal activation of transforming growth factor-‍β (TGF-‍β)/Smads pathway (Finnson et al., 2013; Song et al., 2018). Genetic factors, including race and skin tone, are considered to contribute to keloid formation. The reported incidence of keloids in black people is as high as 16%, whereas white people are less affected. The prevalence ratio of colored people to white people is 5:1‍‍-‍‍15:1 (Rockwell et al., 1989; LaRanger et al., 2019). In addition, keloids have not been reported in albinism patients of any race, and those with darker skin in the same race are more likely to develop this disease (LaRanger et al., 2019). Skin melanocyte activity is significantly different among people with different skin tones. The more active the melanocyte function, the more melanin is produced and the darker the skin. Similarly, in the same individual, the incidence of keloids increases during periods when melanocytes are active, such as adolescence and pregnancy. Keloids rarely appear in areas where melanocytes synthesize less melanin, such as in the palms and soles. Thus, the formation of keloids seems to be closely related to melanocyte activity.
Adolescent ; Cells, Cultured ; Exosomes/metabolism* ; Fibroblasts/metabolism* ; Humans ; Keloid/pathology* ; Melanins/metabolism* ; Melanocytes/pathology* ; Pilot Projects ; Skin/metabolism* ; Transforming Growth Factor beta/metabolism*

Objective: To explore the clinical effects of pulsed dye laser (PDL) dynamically combined with triamcinolone acetonide (TAC) in the treatment of keloids. Methods: A retrospectively observational study was conducted. From April 2015 to October 2020, 34 keloid patients (46 keloids) who met the inclusion criteria were admitted to Huaihe Hospital of Henan University. The patients were divided into TAC group and dynamic treatment group according to their treatment methods. There were 18 patients (26 keloids) in TAC group, including 8 males and 10 females, aged (30±12) years, who were treated with TAC injection alone. There were 16 patients (20 keloids) in dynamic treatment group, including 6 males and 10 females, aged (26±11) years, who were treated with TAC injection, PDL, or PDL combined with TAC injection according to the Vancouver scar scale (VSS) score before each treatment. Before the first treatment (hereinafter referred to as before treatment) and 12 months after the first treatment (hereinafter referred to as after treatment), the keloids were assessed by VSS, patient and observer scar assessment scale (POSAS), and the effect of keloids on the quality of life of patients was evaluated with dermatology life quality index (DLQI) scale. Twelve months after treatment, the curative effect of keloid was evaluated according to the VSS score and the effective rate was calculated. The first effective time and the cumulative times of TAC injection at the first effective time, the number of follow-up and the occurrence of adverse reactions of keloids within 12 months after treatment were recorded, and the incidence of adverse reactions was calculated. Data were statistically analyzed with paired sample t test, independent sample t test, Wilcoxon rank-sum test, Mann-Whitney U test, chi-square test, and Fisher's exact probability test. Results: The total VSS scores of patients' keloids in TAC group and dynamic treatment group 12 months after treatment were significantly lower than those before treatment (with t values of 7.53 and 8.09, respectively, P<0.01), and the total scores of pigmentation and vascularity in VSS and POSAS, the total POSAS score, and the DLQI scale score were significantly lower than those before treatment (with Z values of -3.71, -4.04, -4.21, -4.11, -3.76, -3.73, -3.92, and -3.93, respectively, P<0.01). The total scores of pigmentation and vascularity in VSS and POSAS of patients' keloids in dynamic treatment group 12 months after treatment were significantly lower than those in TAC group (with Z values of -2.03 and -2.12, respectively, P<0.05). Twelve months after treatment, the effective rate of patients' keloids in dynamic treatment group was significantly higher than that in TAC group (χ²=3.88, P<0.05). The first effective time of patients' keloids in dynamic treatment group was 5.5 (2.0, 6.0) months, which was significantly shorter than 6.0 (2.3, 10.3) months in TAC group (χ²=4.02, P<0.05). The cumulative times of TAC injection at the first effective time of patients' keloids in dynamic treatment group was 3.2±1.7, which was significantly less than 4.2±1.8 in TAC group (t=2.09, P<0.05). The number of follow-up of patients' keloids within 12 months after treatment in dynamic treatment group was significantly more than that in TAC group (t=-2.94, P<0.01), and the total incidence of adverse reactions was lower than that in TAC group but without statistically significant difference (P>0.05). Conclusions: Compared with TAC injection alone, PDL dynamically combined with TAC in the treatment of keloid can shorten the effective time, reduce the number of TAC injection, and improve the patient's compliance and clinical efficacy.
Female ; Humans ; Keloid/pathology* ; Lasers, Dye/therapeutic use* ; Male ; Quality of Life ; Retrospective Studies ; Treatment Outcome ; Triamcinolone Acetonide/therapeutic use*

OBJECTIVETo investigate the effect of Metformin on the proliferation and collagen synthesis of the human keloids fibroblasts as well as the effect on phosphorylation of Akt/FoxO1 signal transduction pathway.

METHODSFibroblasts of keloid were divided into control group treated with medium solution and experimental groups treated with different concentrations of Metformin. 48 h later CCK-8 assay was adopted to evaluate cell survival; Western blot was performed to detect the Akt and FoxO1 phosphorylation; and Hydroxyproline reagent kit was used to detect the collagen synthesis.

RESULTSWith different concentrations (30, 60, 90, 120 mmol/L) of Metformin, the absorbance of cultured keloid fibroblasts detected by CCK8 assay decreased by (13.30 ± 2.04)%, (22.64 ± 4.70)%, (54.00 ± 5.34)% and (63.12 ± 3.48)%. The growth of fibroblasts was suppressed by Metformin in a dose-dependent manner. It showed that the level of phoshpo-akt and phoshpo-foxOl in keloids fibroblasts in experimental groups was lower than that in the control group and the collagen synthesis were also decreased in experimental groups, all in a dose-dependent manner (P < 0.05, P < 0.01).

CONCLUSIONSMetformin can effectively inhibit the proliferation and collagen synthesis of the human keloids fibroblasts in vitro, which may be associated with the suppression of phosphorylation of Akt/FoxO1 signaling pathway

Cell Proliferation ; drug effects ; Collagen ; biosynthesis ; Dose-Response Relationship, Drug ; Fibroblasts ; cytology ; drug effects ; metabolism ; Forkhead Box Protein O1 ; Forkhead Transcription Factors ; metabolism ; Humans ; Keloid ; pathology ; Metformin ; pharmacology ; Phosphorylation ; Proto-Oncogene Proteins c-akt ; metabolism ; Signal Transduction ; drug effects

OBJECTIVETo construct and characterize the TGF-β1, induced epithelial-mesenchymal transition (EMT) model of keloid epithelial cells in vitro, and to investigate the expression of epithelial stem cells related surface markers in keloid epithelial cells during EMT induction.

METHODSThe epithelial cells from 3 keloid samples of ears were cultured in vitro and induced by transforming growth factor betal (TGF-β1, 1 ng/ml) for 5 days, which was the experimental group, the same cells untreated were considered as the negative control group. The expressions of EMT-associated markers and regulative genes were detected using immunofluorescence staining, real-time PCR and western blot analysis. Then the surface markers of epithelial stem cells were detected using real-time PCR. Statistical significance was determined using Independent-Samples t Test, a p value less than 0. 05 was considered statistically significant.

RESULTSThe mRNA expression of transcription factor snail2 and mesenchymal-specific marker vimentin increased significantly in TGF-β1, induced keloid epithelial cells (P < 0. 05), in which snail2 increasing from 0. 91 ± 0. 23 to 1. 69 ± 0. 10, and vimentin from 5. 86 ± 2. 07 to 24. 29 ± 5. 39. Whereas the mRNA expression of epithelial-specific marker E-cadherin decreased from 1. 06 ± 0. 19 to 0. 65 ± 0. 09. The mRNA expression of CD29 and Lgr6, two surface markers of epithelial stem cells, significantly increased after induction of the TGF-β1, (P < 0. 05), from 0. 55 ± 0. 14 and 1. 61 ± 0. 31 to 1. 19 ± 0. 12 and 3. 84 t 0. 62 respectively. In induced cells, the immunofluorescence results showed staining of E- cadherin became faint, but the number of positive staining cells of vimentin increased. Western blot confirmed the protein expression of E-cadherin weakened, and the vimentin and p-Smad3 enhanced (P < 0. 05).

CONCLUSIONSTGF-β1, initiated EMT in keloid epithelial cells by inducing the up-regulation of snail2, and TGF-β1,/Smad3 signaling pathway was involved in EMT. EMT could change the phenotype of epithelial stem cells in keloid.

Biomarkers ; metabolism ; Cadherins ; genetics ; metabolism ; Epithelial Cells ; drug effects ; physiology ; Epithelial-Mesenchymal Transition ; drug effects ; physiology ; Humans ; In Vitro Techniques ; Keloid ; pathology ; RNA, Messenger ; metabolism ; Signal Transduction ; Smad3 Protein ; genetics ; metabolism ; Snail Family Transcription Factors ; Transcription Factors ; genetics ; metabolism ; Transforming Growth Factor beta1 ; metabolism ; pharmacology ; Up-Regulation ; Vimentin ; genetics ; metabolism

OBJECTIVETo investigate the effect of 8-aminolevulinic acid (ALA) photodynamic therapy (PDT) on the cell proliferation, apoptosis and collagen secretion in keloid fibroblasts and to provide the theoretical base for ALA-PDT treatment of keloids.

METHODSFibroblasts from keloid patients were cultured to the third generation in vitro and incubated in 0, 1, 3, 6, 9 mmol/L of δ-aminolevulinic acid for 3 h in the darkness. Then they were exposed to 635 nm wavelength red light ( 30 J/cm2 ) and continued incubation 24 h after irradiation. CCK-8 assay was used to detect proliferation inhibition rate of fibroblasts. The content of hydroxyproline was measured by colorimetric method. The expression of p-Akt and programmed cell death 4 ( PDCD4) were detected by Western blot.

RESULTSThe inhibition rate of keloid fibroblasts were respectively 0, (8.30 ± 1.01)%, (29.48 ± 3.27)%, (52.01 ± 5.34)%, (79.99 ± 5.85)% with the presence of difference concentrations (0, 1, 3, 6, 9 mmol/L) of ALA. The content of hydroxyproline were respectively (9.540 0 ± 0.352 42), (6.242 5 ± 0.224 85 ), (5.107 5 ± 0.534 88), (3.490 0 ± 0.623 48), (2.945 0 ± 0.514 10) μg/mg. The relative expression of p-Akt were respectively 1, 0.75 ± 0.12, 0.52 ± 0.14, 0.41 ± 0.18, 0.32 ± 0.09. The relative expression of PDCD4 were respectively 1, 1.18 ± 0.19, 1.51 ± 0.22, 0.15 ± 0.30, 2.44 ± 0.22. The difference was statistically significant when compared the group of 1, 3, 6, 9 mmol/L with 0 mmol/L (P < 0.05).

CONCLUSIONSIn concentration within the range of 1-9 mmol/L, ALA could inhibit the proliferation of fibroblasts significantly, promote fibroblasts apoptosis and reduce the content of hydroxyproline in a dose-dependent manner, indicating that 8-aminolevulinic acid photodynamic therapy may be a potential treatment for keloid.

Aminolevulinic Acid ; pharmacology ; Apoptosis ; drug effects ; Cell Culture Techniques ; Cell Proliferation ; drug effects ; Collagen ; secretion ; Fibroblasts ; cytology ; drug effects ; secretion ; Humans ; Keloid ; drug therapy ; pathology ; Light ; Photochemotherapy ; methods ; Photosensitizing Agents ; pharmacology

OBJECTIVETo investigate the effect of hIL-24 gene on proliferation, migration and invasion activity of human keloid fibroblasts (KFs).

METHODShIL-24 gene was cloned into lentivirus vector, then the lentivirus particles expressing hlL-24 were infected into KF cells. Real-time PCR and Western blot were performed to examine the expression of hIL-24 in lentivirus infected cells. The growth ability was detected by MTT assay. The cell cycle was analyzed by flow cytometry, The invasion and migration were detected by matrigel invasion assay and wound healing assay.

RESULTSComparing to controls group and KF-NC group, the expression levels of hIL-24 mRNA and protein were both significantly up-regulated after 4 days of hIL-24 lentivims infection. Comparing with the KF-NC group, MTT assay showed that the A490 of KF-hlL-24 group was down-regulated after lentivims infection ( P < 0. 05 ). Comparing with the KF-NC group, Cell cycle test revealed hlL-24 gene could block KF cells in G1 [(75. 40 ±2. 10)% ] , the proportion of KF cells was decreased in S phase [(4. 96 ± 1. 60)% ] and G2 phase [(0.01 ± 0.01)% ]. After KF cells were infected(P <0.01). Transfection of hlL-24 lentivirus inhibited the migration and invasion activity of KF cells.

CONCLUSIONLentivirus-mediated hlL-24 gene efficiently inhibits proliferation, cell cycle progression, migration and invasion activity of KF cells.

Cell Cycle ; Cell Line, Tumor ; Cell Movement ; genetics ; Cell Proliferation ; genetics ; Down-Regulation ; Fibroblasts ; physiology ; virology ; Genetic Vectors ; Humans ; Interleukins ; genetics ; physiology ; Keloid ; genetics ; pathology ; Lentivirus ; RNA, Messenger ; metabolism ; Transfection ; methods

OBJECTIVETo observe the effects of conditioned medium from keloid fibroblasts under hypoxia on angiogenesis, and to investigate the role of hypoxic microenvironment in invasive growth of keloid.

METHODSPrimary keloid fibroblasts and human umbilical endothelial cells (HUVEC) were cultured as conventional method. Keloid fibroblasts were cultured either in a hypoxic incubator (2% O2) for 48 h or in a normoxic incubator (20% O2) as control. Then those cell culture mediums were collected and mixed with endothelial cell medium by the proportion of 1:1 as conditioned medium. The mRNA and secreted protein of pro-angiogenic factors such as vascular endothelial growth factor (VEGF), angiopoietin-1 (Ang-1) and periostin of keloid fibroblasts under hypoxia were detected by real time PCR and ELISA. The proliferation, migration and invasion, tube formation of HUVEC cultured with conditioned medium were evaluated by CCK-8 assay, Transwell assay and matrigel tube formation assay, respectively.

RESULTSHypoxia increased the expression of VEGF, Ang-1 and periostin in both mRNA (increased by 75%, 43% and 118% respectively, P < 0.05) and secreted protein (increased by 30.2%, 14.2% and 19.5% respectively, P < 0.05) levels; the proliferations of HUVEC in hypoxic conditioned medium in 1, 2 and 3 d were 0.67 +/- 0.07, 0.84 +/- 0.09 and 1.08 +/- 0.10 respectively, which were higher compared to those in control group (0.52 +/- 0.08, 0.72 +/- 0.10 and 0.91 + 0.14, P < 0.05); the numbers of migration, invasion and tube formation of HUVEC were (73.2 +/- 8.9), (56.3 +/- 12.5), (9.66 +/- 1.96) cells/HP, which were higher compared to those in control group [(59.0 +/- 8.0), 35.5 +/- 8.5), (6.5 +/- 1.87) cells/HP, P < 0.05].

CONCLUSIONSHypoxia increases the expression of pro-angiogenic factors of keloid fibroblasts, and its conditioned medium under hypoxia could promote angiogenesis. The results suggest hypoxic microenvironment may play a significant role in the invasive growth of keloid by inducing angiogenesis.

Cell Hypoxia ; Cells, Cultured ; Culture Media, Conditioned ; Fibroblasts ; Humans ; Keloid ; pathology ; Neovascularization, Pathologic