So far, studies on the mechanism of scar formation have mainly focused on cells, cytokines and extracellular matrix. Some studies have shown that fibroblast is one of the most important element in the process of scar formation, while epidermal and endothelial cells exert synergistic effects as well. Genetic factor can not be ignored in scar formation, either. Recently, studies have shown decisively the loss or damage of the three-dimensional structure of dermal tissue is the initiator of scar formation. Thus, the defect of epidermis template is proposed as a theory in order to explain the mechanism of scar formation. There are various techniques for scar treatment. The commonly accepted methods are physical therapy, pressure therapy, pharmaceutical therapy, radiotherapy, etc.
Cicatrix ; metabolism ; pathology ; therapy ; Dermis ; pathology ; Humans

OBJECTIVETo study the expression of P57(kip2) and Maspin in the pathological scar and their possible role in the pathogenesis of abnormal scars.

METHODSImmunohistochemistry integrated image analysis and reverse transcription polymerase chain reaction (RT-RCR) were performed to detect the expression of P57(kip2) and Maspin in hypertrophic scar, keloid, mature scar and normal skin. Statistics was used to analyze the datas.

RESULTSThe expression of P57(kip2) protein was fixed to fibroblast intranuclear in abnormal scar, and the expression of P57(kip2) protein and P57(kip2) mRNA decreased (P < 0.05). The expression of Maspin protein was fixed to fibroblast cytoplasm and intranuclear in abnormal scar, and the expression of Maspin protein and Maspin mRNA decrease, compared with that in normal group (P < 0.05). There was positive correlation between P57(kip2) protein and Maspin protein expression (P < 0.01).

CONCLUSIONSThe decreased expression of P57(kip2) and Maspin in abnormal scar shows that they are cicatrix-related genes. There is a positive relationship between the two genes. It may be one of the mechanisms of pathogenesis of abnormal scar. It makes effect through fibroblasts.

Cicatrix ; metabolism ; pathology ; Cicatrix, Hypertrophic ; metabolism ; pathology ; Cyclin-Dependent Kinase Inhibitor p57 ; metabolism ; Fibroblasts ; metabolism ; Humans ; Serpins ; metabolism

Blood supply is believed to be an important aspect in the development of pathological scars. However, there are controversies about vascular distribution, vascular structure and blood flow in pathological scars. Additionally, hypoxic microenvironment plays an important role in the vascularization of pathological scar tissues, and hypoxic conditions can be reflected by metabolic indexes and some cytokines. Furthermore, the correlation between blood supply and tissue hypoxia is controversial. The aim of this article is to review the literature on the characteristics of blood supply and tissue hypoxia in pathological scars, from which we can see pathological scars have unique characteristics of blood supply that are closely associated with tissue hypoxia. Moreover, development in the treatment of pathological scars is herein reviewed.
Cell Hypoxia ; Cicatrix ; blood ; metabolism ; Humans ; Regional Blood Flow

OBJECTIVETo explore the role of collagen degradation and scar morphology and structure in the formation of hypertrophic scar.

METHODSSDS-PAGE (sodium dodecyl sulfate polyacrylamide gel electrophoresis) plus collagen substrate electrophoresis, amino acid analysis and compound staining were employed to observe the collagenase activity within hypertrophic scar, collagen degradation and the tissue morphology of the scar.

RESULTSThere exhibited deranged collagen fibres within hypertrophic scar, and large amounts of acid mucopolysaccharide closely surrounded the collagen fibres. All these led to an obvious decrease in collagenase activity and reduction of collagen degradation.

CONCLUSIONThe decrease of collagen degradation and the formation of hypertrophic scar might be closely related to the decrease in collagenase activity and the inhibiting activity of acid mucopolysaccharide on collagenase.

Adolescent ; Adult ; Child ; Cicatrix, Hypertrophic ; metabolism ; pathology ; Collagen ; metabolism ; Collagenases ; metabolism ; Female ; Humans ; Male

OBJECTIVETo investigate the influence of substance P (SP) on the release of histamine in the human hypertrophic scar tissue, and to explore the prerequisite of their interaction.

METHODSTissue specimens of normal skin and hypertrophic scar from eight hospitalized patients were excised and cut into 0.5 to 1.0 mm3 pieces, and the histamine release by mast cell (MC) under the stimulation of different concentration of SP and calcium, as well as the different affect time of SP, were determined with fluorescence spectrometer. Then the histamine release rate was calculated.

RESULTSThere was obvious release of histamine when SP concentration was 1 x 10(-6) mol/L , and the release rate was (50.0 +/- 3.6) %, which was significantly higher than that by SP in the concentration of 0 mol/L [(44.0 +/- 3.2) %, P < 0.01]. Therefore it seemed to be dose-dependent. About 90% of histamine was released within 15 minutes of 5 x 10(-1) mol/L Substance P stimulation, and it was also time-dependent. The histamine release reached the peak when calcium concentration was 5 x 10(-3) mol/L, which seemed to be dose-dependent, but it decreased transiently when calcium concentration was 1 x 10(-3) mol/L. In all occasions, the influence of SP on the histamine release by MC in hypertrophic scar (HS) was markedly higher than that in normal skin (NS) (P < 0.01). Conclusion The influence of SP on the histamine release by MC in HS was markedly higher than that in NS, and it might be closely related to itching sensation and the formation of hypertrophic scar.

Child ; Child, Preschool ; Cicatrix, Hypertrophic ; metabolism ; Female ; Histamine ; metabolism ; Humans ; Male ; Skin ; metabolism ; Substance P ; pharmacology

OBJECTIVE: To investigate the relationshion between the angiogenesis of different kinds of scar and expression of HO-1. METHODS: The expression of heme oxygenase-1 and vessel counted by CD34 of biopsies from different kinds of scars such as hypertrophic scar, keloid, surgical scar and normal skin of 24 cases was valued by immunochemical method, and the relationship was compared between them. RESULTS: The vessel count of hypertrophic scar, keloid was significantly abundant compared with surgical scar or normal skin (P < 0.01). While the expression of HO-1 of hypertrophic scar, keloid was obviously higher than that in surgical scar or normal skin (P < 0.01), decreased from hypertrophic scar, keloid, surgical scar to normal skin. There existed a positive correlation between vessel count and the expression of HO-1 (r = 0. 761, P < 0.01) as well as the number of fibroblastic cells (r = 0. 731, P < 0.01) in the study groups. CONCLUSION HO-1 might play a important role in the angiogenesis of scar formation. The cause of these changes may be local. Over angiogenesis is one symbol of pathological scar.
Adult ; Cicatrix ; metabolism ; pathology ; Cicatrix, Hypertrophic ; metabolism ; pathology ; Female ; Heme Oxygenase-1 ; biosynthesis ; genetics ; Humans ; Keloid ; metabolism ; pathology ; Male ; Middle Aged ; Neovascularization, Pathologic ; Skin ; blood supply

OBJECTIVETo investigate the expression of tenascin-C (Tn-C) in keloid and hyperplastic scar (HS).

METHODSTissue samples were harvested from 10 patients with keloid and 10 with HS (6 - 10 months) and from the skin of 5 adult healthy volunteers. The expression of Tn-C in these samples was determined with immunohistochemistry method.

RESULTSThere was scarce expression of Tn-C in the skin tissue in adult healthy volunteers, and it was only present in the dermal papillae at the dermis epidermis conjunctions and partly in the blood vessels and skin appendages adjacent to the basement membrane. There was enhanced expression of Tn-C in the dermal scar tissue and skin appendages in both keloid and HS, especially in keloid, which exhibited a diffused pattern in the tissue. When compared with that in normal skin, the Tn-C expression in the normal skin adjacent to the keloid was enhanced markedly, but not in the normal skin near HS tissue.

CONCLUSIONThere was increased Tn-C expression in keloid and HS (6 - 10 months).

Cicatrix, Hypertrophic ; metabolism ; Female ; Humans ; Immunohistochemistry ; Keloid ; metabolism ; Male ; Skin ; chemistry ; Tenascin ; analysis

Hypertrophic scar is a pathological repair result of excessive accumulation of extracellular matrix after skin damage, which affects the appearance and function of patients with varying degrees. The degree of scar formation is directly related to the strength of inflammatory reaction during wound healing, and excessive or prolonged inflammatory response increases the incidence of hypertrophic scars. Interleukin-6 (IL-6) is a pleiotropic cytokine that is involved in regulating the fibrotic network composed of fibroblasts, macrophages, keratinocytes, and vascular endothelial cells, and is closely related to the formation of hypertrophic scars. This article reviews the role of IL-6 and its signaling pathway in hypertrophic scar formation.
Cicatrix, Hypertrophic/pathology* ; Endothelial Cells/metabolism* ; Fibroblasts/metabolism* ; Humans ; Interleukin-6 ; Skin/pathology* ; Wound Healing/physiology*

Objective: To explore the effect of microRNA(miR)-222 on cell proliferation and apoptosis of fibroblasts in hypertrophic scar (HS) and the underlying mechanisms. Methods: The expression of miR-222 in the HS and the normal skin tissues was detected by real-time RT-PCR. The HS fibroblasts were transfected with miR-222 mimic and miR-222 inhibitor respectively. The cell viability was tested with MTT assay, cell cycle distribution and apoptosis were detected with flow cytometry and the expression levels of proliferation, apoptosis and cell cycle related proteins were determined with Western blot. Direct target of miR-222 was evaluated by dual-luciferase reporter assay. Results: miR-222 was significantly up-regulated in HS tissues compared with normal skin tissues(P<0.05). Overexpression of miR-222 enhanced the cell viability of HS fibroblasts; increased mRNA and protein expressions of proliferating cell nuclear antigen (PCNA), collagen alpha-1 (Ⅰ) chain (Col1A1) and collagen alpha-1 (Ⅲ) chain (Col3A1); increased cell population in S phase and protein expressions of cyclin D1, cyclin E1 and cyclin-dependent kinases 1 (CDK1); inhibited cell apoptosis and reduced protein expressions of caspase-3/9. Overexpression of MMP1 attenuated the effects of miR-222 on the cell viability and apoptosis in fibroblasts, reduced expression levels of PCNA, cyclin D1 and the expression of caspase-3 was increased. Conclusion: miR-222 enhances cell proliferation and inhibits cell apoptosis of HS fibroblasts through negative regulation of MMP1, which suggests that miR-222 and MMP1 might be used as novel biomarkers and targets in diagnostic and therapeutic approaches for HS.
Apoptosis ; genetics ; Cell Proliferation ; genetics ; Cicatrix, Hypertrophic ; Fibroblasts ; Humans ; Matrix Metalloproteinase 1 ; metabolism ; MicroRNAs ; metabolism

Scarring, naturally induced by fibroblasts(Fb) during wound healing, is an essential process in response to repair damaged tissue. Excessive Fb proliferation which produces the excessive collagen deposition, including increased extracellular matrix synthesis or insufficient decomposition, typically contributes to hypertrophic scar(HS) formation. Although exact mechanisms of HS are not yet fully understood, it is generally believed that dysfunction of Fb and regulation of signal pathways play an important role in HS formation. Biologically, Fb function is affected by various factors such as cytokines, extracellular matrix and itself. In addition, modifications of miRNA, ceRNA, lncRNA, peptides and histones participate in HS formation by affecting the biological function of Fb. Despite the clinical importance, very few therapeutic modalities are available to prevent HS. To achieve this, a deeper characterization of Fb is required to identify mechanisms of HS. To the aspect of HS prevention and treatment, we review recent findings, concentrating on Fb function and collagen secretion. The objective of this article is to frame the current understanding, gain the deeper insights into Fb function, and provide the more comprehensive cognition and perspective for prevention and treatment of HS.
Humans ; Cicatrix, Hypertrophic/metabolism* ; Collagen/therapeutic use* ; Fibroblasts ; Signal Transduction ; Extracellular Matrix/metabolism*