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Hypertrophic scar (HS) is a chronic inflammatory skin disorder characterized by excessive deposition of extracellular matrix, and the mechanisms underlying their formation remain poorly understood. We analysed scRNA‐seq data from samples of normal skin and HS. Using the hdWGCNA method, key gene modules of fibroblasts in HS were identified. Non‐negative matrix factorization was employed to perform subtype analysis of HS patients using these gene modules. Multiple machine learning algorithms were applied to screen and validate accurate gene signatures for identifying and predicting HS, and a convolutional neural network (CNN) based on deep learning was established and validated. Quantitative reverse transcription‐polymerase chain reaction and western blotting were performed to measure mRNA and protein expression. Immunofluorescence was used for gene localization analysis, and biological features were assessed through CCK8 and wound healing assay. Single‐cell sequencing revealed distinct subpopulations of fibroblasts in HS. HdWGCNA identified key gene characteristics of this population, and pseudotime analysis was conducted to investigate gene variation during fibroblast differentiation. By employing various machine learning algorithms, the gene range was narrowed down to three key genes. A CNN was trained using the expression of these key genes and immune cell infiltration, enabling diagnosis and prediction of HS. Functional experiments demonstrated that THBS2 is associated with fibroblast proliferation and migration in HS and affects the formation and development of HS through the TGFβ1/P‐Smad2/3 pathway. Our study identifies unique fibroblast subpopulations closely associated with HS and provides biomarkers for the diagnosis and treatment of HS. [ABSTRACT FROM AUTHOR]

Background: Hypertrophic scar (HS) is caused by the abnormal proliferation of fibroblasts and excessive deposition of extracellular matrix (ECM). Emerging evidence demonstrates that c‐Maf positive M2 macrophages were mainly located in the hypertrophic scar tissues of proliferative phase. But whether c‐Maf positive M2 macrophages can promote hypertrophic scar formation through modulating hypertrophic scar fibroblasts remains elusive. Aims: The aim of this study is to investigate the effects of c‐Maf positive M2 macrophages on the biological behaviors and functions of hypertrophic scar fibroblasts and the potential mechanism. Methods: HE and Masson trichrome staining were used to examine the histological features of human hypertrophic scar. Immunofluorescence staining was employed to label and quantify the c‐Maf+/CD68+ M2 macrophages. CCK8, wound healing, and transwell assays were utilized to test the effects of c‐Maf overexpressed M2 macrophages or the cell culture supernatants on the proliferation and migration of hypertrophic scar derived fibroblasts (HFBs) and normal skin derived fibroblasts (NFBs). Western blot and qPCR were harnessed to test the expressions of COL1, COL3, and α‐SMA in the co‐cultivated fibroblasts and TGF‐β1 in the c‐Maf overexpressed M2 macrophages. Results: Increased number of c‐Maf+/CD68+ M2 macrophages were found in HS in contrast to the normal skin (NS). Elevated proliferation and migration were observed in the HFBs or NFBs co‐cultured with c‐Maf overexpressed macrophages or the cell culture supernatants. A higher mRNA and protein expressions of COL1, COL3, and α‐SMA were recorded in the HFBs co‐cultured with c‐Maf overexpressed macrophages or treated with its culture supernatants. In addition, augmented mRNA and protein expressions of TGF‐β1 were also investigated in the c‐Maf overexpressed macrophages. Conclusion: c‐Maf positive macrophages promote hypertrophic scar formation through regulating HFBs proliferation, migration, and ECM deposition via the secreted TGF‐β1. [ABSTRACT FROM AUTHOR]

Background Fat grafting is an effective procedure for breast augmentation, but the variations in this technique result in unpredictable fat retention. Therefore, animal models are needed to simulate the operation and the optimal layer for fat retention. Objectives An autologous fat grafting murine model for breast augmentation was built to detect a new layer for fat grafting in the chest. Methods The left side of the female rat inguinal fat flap was harvested, dissected into small pieces, and autotransplanted into 3 different layers of the breast. Retention rate and hematoxylin and eosin (H&E) staining were measured at 1, 4, 8 12, and 16 weeks. Immunofluorescence staining was utilized to detect adipocytes and endothelial cells, and immunohistochemistry was conducted to evaluate the expression of integrins β1 and α6. Results The volume of fat grafts slightly grew in the intramuscular and submuscular layers at Week 4. Retention rates in the subcutaneous layer and submuscular layer were significantly higher than the intramuscular layer at Week 16. H&E staining showed that oil cysts existed in the subcutaneous layer throughout the 16 weeks. At the terminal time point, well-vascularized mature adipose structures were observed in intramuscular and submuscular layers, with smaller adipocytes in intramuscular layers. Immunohistochemistry analysis showed that integrin β1 was identically expressed in every adipocyte in all the layers, whereas integrin α6 selectively expressed in bigger adipocytes in the intramuscular layer. The expression intensities of integrin β1 and α6 were significantly higher in the intramuscular layer than in the subcutaneous and submuscular layers. Conclusions The angiogenic and moderate mechanical environment makes the submuscular layer the optimal layer for fat retention. [ABSTRACT FROM AUTHOR]

Background Dorsal augmentation with costal cartilage is generally used for aesthetic rhinoplasty. However, the tendency of costal cartilage to warp may jeopardize the aesthetic outcome. Objectives The aim of this study was to describe a new "Z" technique to overcome the warping of costal cartilage after implantation and to evaluate the efficacy of this technique in vitro. Methods A total of 31 pairs of porcine costal cartilage grafts (40 mm × 10 mm × 5 mm) were obtained and kept in Dulbecco's Modified Eagle Medium (Sigma-Aldrich, St. Louis, MO) to maintain cell viability. Paired grafts were obtained and randomly allocated for preparation by the accordion technique and the "Z" technique. Standardized photographs (obtained immediately after operation and at 4 weeks) were used for warping analysis. Biomechanical testing was performed to measure the graft's capacity to resist deformation by an external force. Results Cell viability of the grafts at 4 weeks was comparably good in the accordion group and the Z group (61.88% ± 4.47% vs 67.48% ± 7.03%, P = 0.55). Warping angle was comparable between the 2 groups (P > 0.01). The capacity to resist external force was significantly better in the Z group; the force needed to cause deformation was 3.98 ± 1.04 N in the Z group vs 1.61 ± 0.47 N in the accordion group in lateral view (P < 0.0001), and 1.33 ± 0.41 N vs 0.96 ± 0.24 N, respectively, in frontal view (P = 0.0013). Conclusions The "Z" technique appears to be a simple and effective method to minimize the tendency of costal cartilage to warp after implantation. [ABSTRACT FROM AUTHOR]