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Background Autologous lipofilling is an emerging procedure to treat and possibly reverse dermal scars and to reduce scar-related pain, but its efficacy and mechanisms are poorly understood. Objectives The aim of this study was to test the hypothesis that repeated lipografts reverse dermal scars by reinitiation of wound healing. Methods In a prospective, non-placebo-controlled clinical study, 27 adult patients with symptomatic scars were given 2 lipofilling treatments at 3-month intervals. As primary outcome, clinical effects were measured with the Patient and Observer Scar Assessment Scale (POSAS). Scar biopsies were taken before and after treatments to assess scar remodeling at a cellular level. Results Twenty patients completed the study. Patients’ scars improved after lipofilling. The total POSAS scores (combined patient and observer scores) decreased from 73.2 [14.7] points (mean [standard deviation]) pretreatment to 46.1 [14.0] and 32.3 [13.2] points after the first and second lipofilling treatment, respectively. Patient POSAS scores decreased from 37.3 [8.8] points to 27.2 [11.3] and 21.1 [11.4] points, whereas observer POSAS scores decreased from 35.9 [9.5] points to 18.9 [6.0] and 11.3 [4.5] points after the first and second treatment, respectively. After each lipofilling treatment, T lymphocytes, mast cells, and M2 macrophages had invaded scar tissue and were associated with increased vascularization. In addition, the scar-associated epidermis showed an increase in epidermal cell proliferation to levels similar to that normal in skin. Moreover, lipofilling treatment caused normalization of the extracellular matrix organization towards that of normal skin. Conclusions Autologous lipofilling improves the clinical outcome of dermal scars through the induction of a pro-regenerative immune response, increased vascularization, and epidermal proliferation and remodeling of scar tissue extracellular matrix. Level of Evidence: 4

Background Tumor-associated macrophages (TAMs) are a major component of innate immunity supporting primary tumor growth and metastasis. Chemotherapy is one of the main treatment strategies for solid tumors, while chemoresistance is the major limitation of the chemotherapy for patients with various types of cancer. A number of evidence indicate that TAMs can accumulate in tumors after chemotherapy and contribute to chemoresistance. Methods For the endocytic uptake of EGF we used flow cytometry analysis. Confocal microscopy was used for the analysis of stabilin-1-mediated internalization and endocytic trafficking of EGF in CHO cells and in modeled TAMs differentiated in the presence of conditioned supernatants of breast cancer (MCF-7) and colorectal cancer (Colo206F) cell lines. We performed next-generation sequencing of RNA samples obtained from our modeled TAMs. Validation of sequencing data by real-time PCR was performed for selected genes implicated in the endocytic uptake: DNM3, STX8, DENND1A and EHD1. Results For the first time we demonstrated that stabilin-1 ectopically expressed in CHO cells mediates endocytic uptake of EGF, key growth factor stimulating progression of breast and colorectal cancer. In the model of primary human TAMs, we have demonstrated that cisplatin decreases stabilin-1-mediated internalization and endocytic trafficking of EGF, without affecting gene expression of scavenger receptor stabilin-1. Molecular mechanisms of cisplatin effect on TAMs were uncovered using high throughput RNA sequencing. Gene set enrichment analysis identified that cisplatin contributes to defects in endocyting machinery reducing membrane biogenesis and vesicular transport. Significant suppression of DNM3, STX8, DENND1A and EHD1 genes expression by cisplatin was confirmed by RT-PCR. Conclusions We suggested that suppression of receptor-mediated clearance of tumor-supportive factors, such as EGF, by chemotherapeutic drugs may potentially lead to the tumor progression and/or relapse as a mechanism of macrophage-mediated chemoresistance. This study was supported by grand RSF №19-15-00151. Legal entity responsible for the study National Research Tomsk State University. Funding RSF N19-15-00151. Disclosure All authors have declared no conflicts of interest.