Myofibroblast expression in skin wounds is enhanced by collagen III suppression

Inflammatory Markers Involved in the Pathogenesis of Dupuytren's Contracture

Dupuytren's disease is a common fibroproliferative disease that can result in debilitating hand deformities. Partial correction and return of deformity are common with surgical or clinical treatments at present. While current treatments are limited to local procedures for relatively late effects of the disease, the pathophysiology of this connective tissue disorder is associated with both local and systemic processes (e.g., fibrosis, inflammation). Hence, a better understanding of the systemic circulation of Dupuytren related cytokines and growth factors may provide important insights into disease progression. In addition, systemic biomarker analysis could yield new concepts for treatments of Dupuytren that attenuate circulatory factors (e.g., anti-inflammatory agents, neutralizing antibodies). Progress in the development of any disease modifying biologic treatment for Dupuytren has been hampered by the lack of clinically useful biomarkers. The characterization of nonsurgical Dupuytren biomarkers will permit disease staging from diagnostic and prognostic perspectives, as well as allows evaluation of biologic responses to treatment. Identification of such markers may transcend their use in Dupuytren treatment, because fibrotic biological processes fundamental to Dupuytren are relevant to fibrosis in many other connective tissues and organs with collagen-based tissue compartments. There is a wide range of potential Dupuytren biomarker categories that could be informative, including disease determinants linked to genetics, collagen metabolism, as well as immunity and inflammation (e.g., cytokines, chemokines). This narrative review provides a broad overview of previous studies and emphasizes the importance of inflammatory mediators as candidate circulating biomarkers for monitoring Dupuytren's disease.

Single Dose of N-Acetylcysteine in Local Anesthesia Increases Expression of HIF1α, MAPK1, TGFβ1 and Growth Factors in Rat Wound Healing

In this study, we aimed to investigate the influence of N-acetylcysteine (NAC) on the gene expression profile, neoangiogenesis, neutrophils and macrophages in a rat model of incisional wounds. Before creating wounds on the backs of 24 Sprague-Dawley rats, intradermal injections were made. Lidocaine-epinephrin solutions were supplemented with 0.015%, 0.03% or 0.045% solutions of NAC, or nothing (control group). Scars were harvested on the 3rd, 7th, 14th and 60th day post-surgery. We performed immunohistochemical staining in order to visualize macrophages (anti-CD68), neutrophils (anti-MPO) and newly formed blood vessels (anti-CD31). Additionally, RT-qPCR was used to measure the relative expression of 88 genes involved in the wound healing process. On the 14th day, the number of cells stained with anti-CD68 and anti-CD31 antibodies was significantly larger in the tissues treated with 0.03% NAC compared with the control. Among the selected genes, 52 were upregulated and six were downregulated at different time points. Interestingly, NAC exerted a significant effect on the expression of 45 genes 60 days after its administration. In summation, a 0.03% NAC addition to the pre-incisional anesthetic solution improves neovasculature and increases the macrophages' concentration at the wound site on the 14th day, as well as altering the expression of numerous genes that are responsible for the regenerative processes.

Downregulation of CFTR Is Involved in the Formation of Hypertrophic Scars

Hypertrophic Scars (HTSs) are a complex fibroproliferative disorder, and their exact mechanism is still not fully understood. In this study, we first found that cystic fibrosis transmembrane conductance regulator (CFTR) expression was downregulated in human hypertrophic scars at the RNA and protein levels by microarray data analysis, RT-PCR, and immunofluorescence (IF) staining. To validate that this downregulation of CFTR is involved in the formation of HTSs, we then applied a mechanical overloading intervention in both wild type and CFTR-mutant mice (ΔF508). Our results showed thatΔF508 mice exhibited delayed wound healing and a significantly larger HTS on day 28. Masson staining revealed that there was more collagen deposition in the HTS, and Sirius red staining and IF staining showed a higher ratio of collagen 1/collagen 3 (Col1/Col3) in ΔF508 mice. Real-time RT-PCR showed that the proinflammatory markers were higher in ΔF508 mice in all phases of scar formation, whereas the proliferation marker was similar. Moreover, we harvested the fibroblasts from both mice. Western blotting showed that the expression of Col1 was the same in both mice, and the expression of Col3 was significantly lower in ΔF508 mice. However, in a mechanical overloading condition, the expression of Col1 was significantly higher in ΔF508 mice, and the expression of Col3 was the same in both mice. Taken together, our results indicate that the downregulation of CFTR might affect the function of fibroblasts, resulting in a lower level of collagen type 3 and a higher ratio of Col1/Col3, and thus aggravate the formation of HTSs in mechanical overloading conditions.

Preparation and Properties of Carboxymethyl Chitosan/Alginate/Tranexamic Acid Composite Films

In this study, the porous composite films of carboxymethyl chitosan/alginate/tranexamic acid were fabricated, with calcium chloride as the crosslinking agent and glycerin as a plasticizer. The composite films were characterized by scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. The properties of the composite films, including water absorption, air permeability, and cumulative release rate, were tested. In addition, their hemostatic performance was evaluated. The results showed that the appearance of the films with good adhesion was smooth and porous. FTIR showed that chemical crosslinking between carboxymethyl chitosan and sodium alginate was successful. The excellent cumulative release of tranexamic acid in the composite films (60–80%) gives the films a significant procoagulant effect. This has good prospects for the development of medical hemostasis materials.

Effects of porcine acellular dermal matrix treatment on wound healing and scar formation: Role of Jag1 expression in epidermal stem cells

Skin wound healing involves Notch/Jagged1 signaling. However, little is known how Jag1 expression level in epidermal stem cells (ESCs) contributes to wound healing and scar formation. We applied multiple cellular and molecular techniques to examine how Jag1 expression in ESCs modulates ESCs differentiation to myofibroblasts (MFB) in vitro, interpret how Jag1 expression in ESCs is involved in wound healing and scar formation in mice, and evaluate the effects of porcine acellular dermal matrix (ADM) treatment on wound healing and scar formation. We found that Jag1, Notch1 and Hes1 expression was up-regulated in the wound tissue during the period of wound healing. Furthermore, Jag1 expression level in the ESCs was positively associated with the level of differentiation to MFB. ESC-specific knockout of Jag1 delayed wound healing and promoted scar formation in vivo. In addition, we reported that porcine ADM treatment after skin incision could accelerate wound closure and reduce scar formation in vivo. This effect was associated with decreased expression of MFB markers, including α-SMA Col-1 and Col-III in wound tissues. Finally, we confirmed that porcine ADM treatment could increase Jag1, Notch1 and Hesl expression in wound tissues. Taken together, our results suggested that ESC-specific Jag1 expression levels are critical for wound healing and scar formation, and porcine ADM treatment would be beneficial in promoting wound healing and preventing scar formation by enhancing Notch/Jagged1 signaling pathway in ESCs.

Effect of liposome‑mediated HSP27 transfection on collagen synthesis in alveolar type II epithelial cells

To investigate the effect of liposome Lipofectamine® 2000‑mediated HSP27 plasmid transfection in A549 human alveolar type II epithelial cell line on collagen synthesis during transforming growth factor‑β1 (TGF‑β1)‑induced type II epithelial cell transition to myofibroblasts. Cells were transfected with varying ratios of the Lipofectamine® 2000‑mediated heat shock protein 27 (HSP27) plasmid and the transfection efficiency was determined using flow cytometry. The maximum transfection efficacy was confirmed by laser confocal microscopy. HSP gene expression and the most efficient HSP27 plasmid were determined using reverse transcription‑quantitative polymerase chain reaction. Western blot analysis was used to examine HSP27 and collagen expression levels. With a transfection efficiency of 83%, the 8 µg:20 µl ratio of liposome: Plasmid had the highest transfection levels. Among the four different interference sequences in the HSP27 plasmid, the D sequence had the highest interference effect with 70% silencing of the HSP27 gene. The expression of type I and III collagen in TGF‑β1‑induced transition of A549 human alveolar type II epithelial cell line to myofibroblasts was significantly downregulated by the successful transfection with HSP27‑interfering plasmid. The expression of type I and III collagen in the TGF‑β1‑induced transition of A549 cells to myofibroblasts was significantly downregulated by transfection of A549 cells with HSP27 plasmid D‑interfering sequence and optimal ratio of Lipofectamine® 2000 and HSP27 plasmid.

Liposomes with Silk Fibroin Hydrogel Core to Stabilize bFGF and Promote the Wound Healing of Mice with Deep Second-Degree Scald

How to maintain the stability of basic fibroblast growth factor (bFGF) in wounds with massive wound fluids is important to accelerate wound healing. Here, a novel liposome with hydrogel core of silk fibroin (SF-LIP) is successfully developed by the common liposomal template, followed by gelation of liquid SF inside vesicle under sonication. SF-LIP is capable of encapsulating bFGF (SF-bFGF-LIP) with high efficiency, having a diameter of 99.8 ± 0.5 nm and zeta potential of -9.41 ± 0.10 mV. SF-LIP effectively improves the stability of bFGF in wound fluids. After 8 h of incubation with wound fluids at 37 °C, more than 50% of free bFGF are degraded, while only 18.6% of the encapsulated bFGF in SF-LIP are destroyed. Even after 3 d of preincubation with wound fluids, the cell proliferation activity and wound healing ability of SF-bFGF-LIP are still preserved but these are severely compromised for the conventional bFGF-liposome (bFGF-LIP). In vivo experiments reveal that SF-bFGF-LIP accelerates the wound closure of mice with deep second-degree scald. Moreover, due to the protective effect and enhanced penetration ability, SF-bFGF-LIP is very helpful to induce regeneration of vascular vessel in comparison with free bFGF or bFGF-LIP. The liposome with SF hydrogel core may be a potential carrier as growth factors for wound healing.

Suppressive effects of human fetal keratinocytes on the proliferation, differentiation and extracellular matrix synthesis of human hypertrophic scar fibroblasts in vitro

A hypertrophic scar is characterized by fibroblast proliferation and excessive extracellular matrix deposition. Emerging evidence has revealed that fetal keratinocytes (KCs) contribute to scarless wound healing. However, the association between fetal keratinocytes and hypertrophic scarring remains unclear. In the present study, human KCs of different gestational ages were isolated and co-cultured with human hypertrophic scar fibroblasts (HSFbs) or normal skin fibroblasts. Gene expression and protein levels of fibronectin, collagen 1and α-smooth muscle actin in the fibroblasts were measured by reverse transcription-quantitative polymerase chain reaction and western blot analyses. It was observed that fetal KCs significantly inhibited the proliferation of HSFbs in vitro. Fetal keratinocytes also affected the expression of fibronectin, collagen 1 and α-smooth muscle actin in HSFbs. In addition, miR-940 may modulate the suppressive effects of fetal KCs on the cell proliferation, differentiation and extracellular matrix synthesis of HSFbs by directly targeting transforming growth factor-β1. Taken together, the results of the present study provide evidence to support the potential use of fetal KCs for cell-based therapeutic grafting in the prevention of hypertrophic scarring.

Basic fibroblast growth factor reduces scar by inhibiting the differentiation of epidermal stem cells to myofibroblasts via the Notch1/Jagged1 pathway

Background

Basic fibroblast growth factor (bFGF) plays an important role in promoting wound healing and reducing scar, but the possible molecular mechanisms are still unclear. Our previous studies have found that activating the Notch1/Jagged1 pathway can inhibit the differentiation of epidermal stem cells (ESCs) to myofibroblasts (MFB). Herein, we document that bFGF reduces scar by inhibiting the differentiation of ESCs to MFB via activating the Notch1/Jagged1 pathway.

Methods

In in-vitro study, ESCs were isolated from 10 neonatal SD rats (1–3 days old), cultured in keratinocyte serum-free medium, and divided into six groups: bFGF group, bFGF + SU5402 group, bFGF + DAPT group, siJagged1 group, bFGF + siJagged1 group, and control group. Jagged1 of the ESCs in the siJagged1 group and bFGF + siJagged1 group was knocked down by small-interfering RNA transfection. Expression of ESC markers (CK15/CK10), MFB markers (α-SMA, Collagen I, Collagen III), and Notch1/Jagged1 components (Jagged1, Notch1, Hes1) was detected by FCM, qRT-PCR, and western blot analysis to study the relationships of bFGF, ESCs, and Notch1/Jagged1 pathway. In in-vivo study, the wound healing time and scar hyperplasia were observed on rabbit ear scar models. The quality of wound healing was estimated by hematoxylin and eosin staining and Masson staining. Expression of ESC markers, MFB markers and Notch1/Jagged1 components was elucidated by immunohistochemistry, immunofluorescence, and western blot analysis.

Results

The in-vitro study showed that bFGF could significantly upregulate the expression of ESC markers and Notch1/Jagged1 components, while downregulating the expression of MFB markers at the same time. However, these effects could be obviously decreased when we knocked down Jagged1 or added DAPT. Similarly, in in-vivo study, bFGF also exhibited its functions in inhibiting the differentiation of rabbit ESCs to MFB by activating the Notch1/Jagged1 pathway, which improved the wound healing quality and alleviated scar significantly.

Conclusion

These results provide evidence that bFGF can reduce scar by inhibiting the differentiation of ESCs to MFB via the Notch1/Jagged1 pathway, and present a new promising potential direction for the treatment of scar.

Wound healing potential of lavender oil by acceleration of granulation and wound contraction through induction of TGF-β in a rat model

Background

Although previous studies have suggested that lavender oil promote wound healing, no study has examined the molecular mechanisms of its effect. In this study, we investigated the effect of lavender oil on various steps of wound healing and its molecular mechanism, focusing on transforming growth factor-β (TGF-β).

Methods

Circular full-thickness skin wounds were produced on rats. Control solution or lavender oil was topically applied to the wounds on alternating days for 14 days.

Results

The area of wounds topically treated with lavender oil was significantly decreased as compared to that of wounds of control rats at 4, 6, 8, and 10 days after wounding. Topical application of lavender oil induced expression of type I and III collagen at 4 days after wounding, accompanied by an increased number of fibroblasts, which synthesize collagen. Induced expression of type III collagen by topical application of lavender oil was reduced to control level at 7 days after wounding although increased expression of type I collagen still continued even at 7 days, suggesting rapid collagen replacement from type III to type I in wounds treated with lavender oil. Importantly, expression of TGF-β in wounds treated with lavender oil was significantly increased as compared to control. Moreover, an increased number of myofibroblasts was observed in wounds treated with lavender oil at 4 days after wounding, suggesting promotion of differentiation of fibroblasts through induction of TGF-β, which is needed for wound contraction.

Conclusion

This study demonstrated that topical application of lavender oil promoted collagen synthesis and differentiation of fibroblasts, accompanied by up-regulation of TGF-β. These data suggest that lavender oil has the potential to promote wound healing in the early phase by acceleration of formation of granulation tissue, tissue remodeling by collagen replacement and wound contraction through up-regulation of TGF-β. The beneficial effect of lavender oil on wound healing may raise the possibility of new approaches as complementary treatment besides conventional therapy.

Heparin-Based Coacervate of FGF2 Improves Dermal Regeneration by Asserting a Synergistic Role with Cell Proliferation and Endogenous Facilitated VEGF for Cutaneous Wound Healing

Effective wound healing requires complicated, coordinated interactions and responses at protein, cellular, and tissue levels involving growth factor expression, cell proliferation, wound closure, granulation tissue formation, and vascularization. In this study, we develop a heparin-based coacervate consisting of poly(ethylene argininylaspartate digylceride) (PEAD) as a storage matrix, heparin as a bridge, and fibroblast growth factor-2 (FGF2) as a cargo (namely heparin-FGF2@PEAD) for wound healing. First, in vitro characterization demonstrates the loading efficiency and control release of FGF2 from the heparin-FGF2@PEAD coacervate. The following in vivo studies examine the wound healing efficiency of the heparin-FGF2@PEAD coacervate upon delivering FGF2 to full-thickness excisional skin wounds in vivo, in comparison with the other three control groups with saline, heparin@PEAD as vehicle, and free FGF2. Collective in vivo data show that controlled release of FGF2 to the wounds by the coacervate significantly accelerates the wound healing by promoting cell proliferation, stimulating the secretion of vascular endothelial growth factor (VEGF) for re-epithelization, collagen deposition, and granulation tissue formation, and enhancing the expression of platelet endothelial cell adhesion molecule (CD31) and alpha-smooth muscle actin (α-SMA) for blood vessel maturation. In parallel, no obvious wound healing effect is found for the control, vehicle, and free FGF2 groups, indicating the important role of the coavervate in the wound healing process. This work designs a suitable delivery system that can protect and release FGF2 in a sustained and controlled manner, which provides a promising therapeutic potential for topical treatment of wounds.