The cytokine-receptor- heparin sulfate functional complex combined by cytokines, cytokine receptors, and heparin sulfate chains formed by concatenation of heparin sulfate proteoglycans (HSPG), an important component of extracellular matrix and modified by some relative enzymes, can regulate the density of cytokine receptors and their intracellular signal transduction. This article focused on the regulatory function of this complex. Many morphological abnormalities and diseases occur when the complex is dysfunctional.

To investigate the expression characteristics of fibroblast growth factor 10 (FGF10) and its receptor (Bek) underlying their effect on the formation of fetal skin appendages (SA). Expressions of FGF10, Bek, cytokeratin (CK19), Bcl-2 and proliferating cell nuclear antigen (PCNA) were detected with pathological and immunohistochemistry techniques in 130 skin specimens, which were obtained from 5 different sites (head, lower jaw, ear lobe, shoulder and presternal region) of 26 fetuses at different embryonic ages (E 8～31weeks). Results showed that FGF10, PCNA and Bcl-2 were over-expressed in interstitial cells distributed in clumps under the epidermis, and all proteins were strongly expressed in epidermal cells and pericytes at E 11weeks. In E 13weeks fetal skin, epidermal cells formed SA anlage through focal proliferation; then they developed, differentiated and migrated towards the dermis. In the skin of E 11～13weeks fetus, the expression of FGF-10, PCNA and Bcl-2 in interstitial cells in the dermis, and the expression of FGF10, Bek, PCNA, CK19, and Bcl-2 proteins in the epithelial cells in SA showed the expression characteristics of these proteins which were in accordance with growth and development of fetal SA. The results suggested that the specific binding of FGF10 from interstitial cells with Bek on the membrane of epithelial cells was the important signal to induce the proliferation and morphogenesis of embryonic SA epithelial \{cells.\ \ \ \}

Objective To explore the correlation of the formation of pseudoepitheliomatous hyperplasia (PEH) after healing of inappropriately treated wound of skin with epithelial mesenchymal cells transdifferentiation (EMT). Methods Morphological change in epithelial tissue was observed with histopathologic methods in epithelial cells from PEH lesions ( n =11) and normal skin specimens obtained adjacent to PEH (PEH N, n =6) from 11 patients with PEH. At the same time, the characteristic of expressions and distribution of type Ⅰ and Ⅲ collagen, alpha smooth muscule actin (? SMA), vimentin (Vim), desmin (Des), transforming growth factor ?1 (TGF ?1)and its receptor (TGFRI), pan cytokeratin (CKp), and type Ⅳ collagen in PEH were examined with indirect immunofluorescent double labelling method. Results In comparison with PEH N, squamous epithelium in PEH presented a picture of atypical hyperplasia, there was a derangement of basal apical polarity, disrupture in structure, and a displacement of cells foward mesenchyme. Examination under electron microscope revealed deformation of epithelial basal cells, with loose intercellular junction, and newly formed tumor like cells distingaishable from original epithelial cells. Expressions of type Ⅰ and Ⅲ collagen,? SMA,Vim and Des could be detected in the epithelial cells of PEH. However,the protein expressions of CKp, Ⅳ type collagen were significantly decreased in basal epithelial cells. Furthermore, free epithelial cells expressing CKp were found in the deep layer of mesenchyme. Conclusion It was confirmed for the first time that there was a phenomenon of EMT during the course of PEH formation. Epithelial cells in PEH lesion with granuloma and non hypertrophic scar are characteristized by de differentiation, redifferentiation and a decrement of TGF ?1 induction, which are involved in reactive hyperplasia of the epithelium.

AIM: To investigate gene expression of bax, bcl-2 and p53 in fetal skin at different gestational ages and children skin in order to explore their potentially biological significance. METHODS: Apoptosis in skin specimens was determined by terminal deoxynucleotidy transferase mediated dUTP-biotin nick-end labeling technique (TUNEL). Gene expressions of bax, bcl-2 and p53 in skin at different developmental stages was examined with reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: Along with fetal growth and development, the incidence rate of apoptosis was increased progressively in skin. In skin from early gestational fetus, bcl-2 was strongly expressed. This gene expression was progressively decreased with increment in gestational age. In children skin, the mRNA content of this gene was significantly reduced compared with fetal skin (P

Objective:To explore the effects and mechanism of interleukin-17 (IL-17)-modified mouse bone marrow mesenchymal stem cells (BMSCs) on the allogeneic skin transplantation in mice.Methods:(1) The femur, tibia, and humerus were isolated from five BALB/c mice (all female, aged 4 to 8 weeks, the same gender and age below) after sacrifice. BMSCs were isolated, purified, and cultured by whole bone marrow density gradient centrifugation combined with adherent separation method. The third passage of cells was used for morphological observation and identification of adipogenic and osteogenic differentiation. The fourth passage of cells was used for identification of the expression of stem cell surface markers. The third to sixth passages of BMSCs were pretreated with mouse recombinant IL-17 at a final mass concentration of 50 ng/mL for 5 days, and then were harvested for morphological observation. After being labeled with carbocyanine fluorescent dye (CM-Dil), IL-17-pretreated BMSCs and IL-17-unpretreated BMSCs were obtained for morphological observation and the labeling rates were calculated. (2) Forty-five C57BL/6J mice were divided into phosphate buffer solution (PBS) control group ( n=13), BMSCs alone group ( n=16), and BMSCs+ IL-17 group ( n=16) according to the random number table. One day before the skin transplantation of mice, 0.1 mL BMSCs (5×10 6 cells/mL) without CM-Dil labeling were injected to the 13 mice in BMSCs alone group through the tail vein, and 0.1 mL BMSCs (5×10 6 cells/mL) labeled with CM-Dil were injected to the other 3 mice in BMSCs alone group through the tail vein. IL-17-pretreated BMSCs (5×10 6 cells/mL) without CM-Dil labeling in the volume of 0.1 mL were injected to the 13 mice in BMSCs+ IL-17 group through the tail vein, and 0.1 mL IL-17-pretreated BMSCs (5×10 6 cells/mL) labeled with CM-Dil were injected to the other 3 mice in BMSCs+ IL-17 group through the tail vein. PBS in the volume of 0.1 mL was injected to the 13 mice in PBS control group through the tail vein. Forty-five BALB/c mice were used as donors, and forty-five treated C57BL/6J mice in the 3 groups were used as recipients to establish a back-to-back full-thickness skin transplantation model. On the 2nd day after transplantation, the same number of corresponding cells and the equal amount of PBS were injected to the recipient mice of each group again. On the 7th day after transplantation, three mice injected with CM-Dil-labeled BMSCs in BMSCs alone group and three mice injected with CM-Dil-labeled IL-17-pretreated BMSCs in BMSCs+ IL-17 group were sacrificed by cervical dislocation to track the CM-Dil-labeled BMSCs by fluorescence microscope, which was counted. After the dressing removal on the 6th day post transplantation, 7 mice were selected respectively from 13 mice in BMSCs alone group injected with BMSCs without CM-Dil-labeling, 13 mice in BMSCs+ IL-17 group injected with IL-17-pretreated BMSCs without CM-Dil-labeling, and 13 mice in PBS control group, respectively, to record the skin graft survival time. On the 8th day post transplantation, three of the remaining six mice in the three groups were taken for general observation of the grafted skin, serum levels of interferon-γ, IL-10, and transforming growth factor β (TGF-β) by enzyme-linked immunosorbent assay method, the percentage of CD4 + CD25 + forkhead/winged helix transcription factor p3 (Foxp3) + regulatory T cells (Tregs) in spleen by flow cytometer, and the histopathological observation of the grafted skin by hematoxylin eosin staining. The rest three mice in each group were also taken for histopathological observation as above on the 14th day post transplantation. Data were statistically analysed with independent sample t test, one-way analysis of variance, and least significant difference test. Results:(1) There were no significant differences in the morphology and size between IL-17-pretreated BMSCs and IL-17-unpretreated BMSCs on culture day 5. (2) After CM-Dil labeling, BMSCs and IL-17-pretreated BMSCs grew well, and the labeling rate was almost 100%. (3) On the 7th day post transplantation, there were 6.2±2.6 CM-Dil-labeled BMSCs per 100 fold visual field in the skin and adjacent subcutaneous tissue of mice in BMSCs alone group, which were significantly fewer than the 15.0±5.3 CM-Dil-labeled IL-17-pretreated BMSCs per 100 fold visual field in BMSCs+ IL-17 group ( t=-2.962, P<0.05). (4) The skin graft survival time of mice in BMSCs alone group and BMSCs+ IL-17 group was (13.3±1.2) and (17.0±1.5) days respectively, significantly longer than (8.7±0.8) days in PBS control group ( P<0.01), and the skin graft survival time of mice in BMSCs+ IL-17 group was significantly longer than that in BMSCs alone group ( P<0.01). (5) On the 8th day post transplantation, most of the skin grafts of mice in PBS control group was black, scabby, and necrotic. Most of the skin grafts of mice in BMSCs alone group survived well, while all the skin grafts of mice in BMSCs+ IL-17 group survived well. (6) On the 8th day post transplantation, compared with those of PBS control group, the serum levels of IL-10 and TGF-β of mice in BMSCs alone group and BMSCs+ IL-17 group were significantly higher ( P<0.01), and the serum level of interferon-γ was significantly lower ( P<0.01). Compared with those of BMSCs alone group, the serum levels of IL-10 and TGF-β of mice in BMSCs+ IL-17 group were significantly higher ( P<0.01), and the serum level of interferon-γ was significantly lower ( P<0.01). (7) On the 8th day post transplantation, the percentages of CD4 + CD25 + Foxp3 + Treg in spleen of mice in BMSCs alone group and BMSCs+ IL-17 group were significantly higher than the percentage of PBS control group ( P<0.01), and the percentage of CD4 + CD25 + Foxp3 + Treg in spleen of mice in BMSCs+ IL-17 group was significantly higher than that of BMSCs alone group ( P<0.01). (8) On the 8th day post transplantation, infiltration of a large number of inflammatory cells and necrosis of epidermis and dermis were found in the skin grafts of mice in PBS control group; focal infiltration of inflammatory cells and slight epidermal degeneration were found in the skin grafts of mice in BMSCs alone group; the skin appendages of the skin grafts of mice in BMSCs+ IL-17 group survived well with angiogenesis. On the 14th day post transplantation, the skin grafts of mice in BMSCs alone group showed extensive infiltration of inflammatory cells, severe epidermal degeneration and focal necrosis; the skin grafts of mice in BMSCs+ IL-17 group showed focal infiltration of inflammatory cells and slight epidermal degeneration; the skin grafts of mice in PBS control group were completely necrotic. Conclusions:IL-17 can reduce the immune rejection in allogeneic skin grafting and prolong the survival time of mouse skin grafts by improving mice BMSCs′ capabilities to induce immune tolerance and enhancing the homing ability of BMSCs.

Fetal dermal mesenchymal stem cells (FDMSCs) are pluripotent stem cells derived from skin tissue of accidentally aborted fetuses of healthy pregnant women who are free of genetic diseases and do not take abortion drug. FDMSCs have exosome secretion activity, high proliferation and self-renewal abilities, low immunogenicity, and advantages of homing to damaged tissue and promoting tissue regeneration. In recent years, studies on basic biological characteristics, capacity of inducing differentiation in vitro, and promotion of skin wound repair provide new direction for the clinical treatment of burn patients in the future. In this review, we summarize the research advances of FDMSCs in promoting burn wound healing.

OBJECTIVETo lower down the antigenicity of heterogenous swine acellular dermal tissue, and to explore the feasibility of clinical using it as a composite graft for human patients.

METHODSSplit-thickness skin was harvested from healthy swines and then processed by two methods. The swine acellular dermal matrix (sADM) was prepared by removing cells from the skin with trypsin and Triton X-100. Then the cross-linked sADM (sADM(1)) and non-cross-linked sADM (sADM(0)) were embedded subcutaneously in rabbits and also transplanted onto the burn wounds of patients. The histological changes and also transplantation results were observed.

RESULTS(1) In animals with sADM(0) embedded subcutaneously, the grafted tissue was invaded immediately by host cells with obvious inflammatory reaction and tissue degradation. But there was less inflammatory reaction, and with no obvious skin degradation and contraction with sADM(1). (2) In ten burn patients with III degree burn wounds and one patient with wound in chest after scar removal, sADM and ultra-thin skin (UTS) composite graft were grafted on the wounds with autologous thin skin (ATS) and autologous razor-thin or UTS as the control. Nineteen pieces of composite skin of sADM with UTS were grafted on the wounds with survival rate of 78.9%, exhibiting no evident difference with that of ATS. When sADM(0) and UTS were grafed, there exhibited remarkable early inflammatory reaction and wound contraction with similar external appearance with that of UTS. Whereas when sADM(1) and UTS were grafted, there appeared less early inflammatory reaction and wound contraction, resulting in an even appearance and soft to touch similar to that with ATS. But ulceration occurred, with exposure of sADM(1), exposure and severe macrophage reaction to foreign body in 6 wounds of 3 cases 12.8 +/- 6.9 weeks after sADM(1) and UTS grafting.

CONCLUSIONGrafting of sADM as a dermal substitute of composite skin could alleviate early post-grafting immune reaction and improve UTS grafting results. But the delayed graft rejection couldn't be avoided.

Animals ; Burns ; surgery ; Dermatologic Surgical Procedures ; Dermis ; immunology ; transplantation ; Humans ; Rabbits ; Skin ; immunology ; injuries ; Skin Transplantation ; methods ; Skin, Artificial ; Swine ; Time Factors ; Transplantation, Heterologous ; Wound Healing

Objective: To investigate the preparation of bioactive denatured acellular dermal matrix (DADM) from burn mice riched in mice bone marrow mesenchymal stem cells. Methods: Twelve BALB/c mice were collected and 20% total body surface area scalds (hereinafter referred to as burns) with deep partial thickness were inflicted on the back skin of each mouse. After removing epidermis, the burned skin were collected and divided into Triton X-100 group and elhylene diamine tetraacetic acid (EDTA) group according to the random number table, with 15 samples in each group. Samples in Triton X-100 group and EDTA group were respectively placed in mixture of 2.5 g/L Triton X-100 and 2.5 g/L trypsin solution and mixture of 0.2 g/L EDTA and 2.5 g/L trypsin solution for sustained vibration and elution for 24 hours to make mice DADM. The general appearance of DADM was observed. The structure and arrangement of collagen fibers of DADM were observed by scanning electron microscope and tissue structure of DADM were observed by fluorescence microscope. Bone marrow mesenchymal stem cells (BMSCs) from mice were transplanted in mice DADM in the two groups with concentration of 2×105 cells per well to prepare bioactive mice DADM. After cultured for 3 days, tissue structure of bioactive mice DADM was observed by hematoxylin and eosin staining, distribution and number of BMSCs of bioactive mice DADM were observed by immunofluorescence staining. Proliferation of BMSCs of bioactive mice DADM after cultured for 2 h, 1 d, 3 d, and 5 d was detected by cell count kit-8. Data were processed with analysis of variance for repeated measurement and t test. Results: (1) Mice DADM in the two groups were white in appearance with certain tenacity and elasticity. Mice DADM in the two groups maintained good three-dimensional porous network structure. Collagen fibers of mice DADM in EDTA group were with good continuity, and collagen fibers of mice DADM in Triton X-100 group were fractured in varying degrees. Mice DADM in the two groups were decellularized completely, and the collagen fibers were loose and arranged disorderly. The continuity of tissue structure of mice DADM in EDTA group was better than that of mice DADM in Triton X-100 group. (2) After cultured for 3 days, the BMSCs in bioactive mice DADM in the two groups were evenly distributed. The number of bioactive BMSCs in mice DADM in EDTA group was 37±7, which was significantly more than that of mice DADM in Triton X-100 group (25±8, t=0.128, P<0.05). The proliferation of bioactive BMSCs in mice DADM in Triton X-100 group and EDTA group was similar at 2 hours and on day 1 after cultured (t=1.292, 0.656, P>0.05). On 3, 5 days after cultured, the proliferation of bioactive BMSCs in mice DADM in EDTA group was significantly higher than that of mice DADM in Triton X-100 group (t=2.309, 14.128, P<0.05 or P<0.01). Conclusions Mice DADM prepared by decellularization of EDTA has better three-dimensional porous network structure and good continuity of collagen fiber. The BMSCs in bioactive DADM from burn mice prepared by transplanting BMSCs are evenly distributed with large quantity and strong proliferative capacity, which has the potential to be good autologous dermal substitute.

Stitching skin wounds is one of the essential skills of a surgeon. Whether it is a traumatic wound or a surgical incision, choosing the most appropriate closure technique according to its characteristics is an important factor for good healing. Various skin wounds suturing techniques have been created and improved over the years, which have advantages of simple operation, precise alignment, reducing tension of the wound edges, and reducing scar formation, etc. Although these techniques provide more options for wound suture, they also put forward requirements for the judgment and operation ability of the operators. This article summarizes the advantages and disadvantages of the different skin wounds suturing techniques and their clinical application.

Scarless healing is considered as the most ideal mode of wound repair. This ability generally exists in the early period of mammalian embryos, however it gradually turns to scar healing with the development of the embryos. This phenomenon is the result of the interaction of multiple biological functions, and the mechanism is still uncertain. This article deals with a systematical review of literature concerning the mechanism of scarless healing based on the recent experimental studies, hoping to provide evidence for the treatment of wounds to realize scarless healing in adult.
Adult ; Animals ; Cicatrix ; prevention & control ; Fetus ; physiology ; Humans ; Wound Healing ; physiology