Modulation of wound contracture alpha-smooth muscle actin and multispecific vitronectin receptor integrin alphavbeta3 in the rabbit's experimental model

LncRNA PVT1 Promotes the Progress of Hypertrophic Scar via Regulating the Proliferation and Migration of Myofibroblasts Through Targeting miR-29a-3p/STAT3

Purpose

Hypertrophic scar (HS) is a common clinical disease during skin injury recovery. Although medicines have been listed for treatment, none are universally effective, and the details of the underlying molecular regulation are yet to be revealed. This research was aimed at exploring the clinical value of lncRNA PVT1 in HS formation and its potential mechanisms in human hyperplastic scar myofibroblasts (HSFs).

Patients and Methods

Fifty-seven HS patients were enrolled. RT-qPCR was conducted to examine the RNA levels of lncRNA PVT1, miR-29a-3p and STAT3. CCK-8, Transwell, and flow cytometry were used to analyze cell proliferation, migration, and apoptosis. The targeting relationship of PVT1/miR-29a-3p and miR-29a-3p/STAT3 was proved by the dual luciferase reporter.

Results

Relative expression of lncRNA PVT1 in human HS tissues was higher compared with normal tissues. LncRNA PVT1 silencing slowed proliferation and migration and accelerated apoptosis in human HSFs. miR-29a-3p was downregulated in human HS tissues, which was negatively correlated with PVT1 levels. LncRNA PVT1 was covalently bound to miR-29a-3p. miR-29a-3p played an important role in the proliferation, migration, and apoptosis of human HSFs. miR-29a-3p inhibitor rescued the negative influence of lncRNA PVT1 silencing on cells. STAT3 was covalently linked to miR-29a-3p.

Conclusion

LncRNA PVT1 was a potential biomarker for HS and regulated the biological behavior of human HSFs via miR-29a-3p/STAT3.

Multifunctional Hydrogel with Photothermal ROS Scavenging and Antibacterial Activity Accelerates Diabetic Wound Healing

Poor diabetic wound healing poses a critical threat to human health. Excessive oxidative stress and increased susceptibility to bacterial infection are key issues that impede diabetic wound healing. Cerium oxide nanoparticles (CeO2 NPs) have attracted increasing attention because of their unique antioxidant and antimicrobial properties. Here, this work designs a near-infrared (NIR) light-responsive gelatin methacryloyl (GelMA)/CeO2/polydopamine (PDA) hydrogel with antibacterial and antioxidant effects. The hydrogel exhibits a stable, efficient, and controllable photothermal conversion capacity under NIR stimulation. The hydrogel can be used to construct a local microenvironment conducive to chronic diabetic wound healing. Significant antibacterial effects of the NIR-responsive GelMA/CeO2/PDA hydrogel on both Escherichia coli (E.coli) and methicillin-resistant Staphylococcus aureus (MRSA) are demonstrated by counting colony-forming units (CFUs) and in bacterial live/dead staining experiments. The strong antioxidant activity of hydrogels is demonstrated by measuring the level of reactive oxygen species (ROS). The effect of the NIR-responsive GelMA/CeO2/PDA hydrogel in terms of promoting diabetic wound healing is validated in full-thickness cutaneous wounds of diabetic rat models. Additionally, this work describes the mechanism by which the NIR-responsive GelMA/CeO2/PDA hydrogel promotes diabetic wound healing; the hydrogel inhibits the interleukin (IL)-17 signaling pathway. This NIR-responsive, multifunctional hydrogel dressing provides a targeted approach to diabetic wound healing.

Nitric oxide-based treatments improve wound healing associated with diabetes mellitus

Non-healing wounds are long-term complications of diabetes mellitus (DM) that increase mortality risk and amputation-related disability and decrease the quality of life. Nitric oxide (NO·)-based treatments (i.e., use of both systemic and topical NO· donors, NO· precursors, and NO· inducers) have received more attention as complementary approaches in treatments of DM wounds. Here, we aimed to highlight the potential benefits of NO·-based treatments on DM wounds through a literature review of experimental and clinical evidence. Various topical NO·-based treatments have been used. In rodents, topical NO·-based therapy facilitates wound healing, manifested as an increased healing rate and a decreased half-closure time. The wound healing effect of NO·-based treatments is attributed to increasing local blood flow, angiogenesis induction, collagen synthesis and deposition, re-epithelization, anti-inflammatory and anti-oxidative properties, and potent broad-spectrum antibacterial effects. The existing literature lacks human clinical evidence on the safety and efficacy of NO·-based treatments for DM wounds. Translating experimental favors of NO·-based treatments of DM wounds into human clinical practice needs conducting clinical trials with well-predefined effect sizes, i.e., wound reduction area, rate of wound healing, and hospital length of stay.

Preclinical determination of wound-healing activity of halibut oil cream in rat model of burn wound

This study investigated the effects of halibut oil cream, containing omega-3 fatty acids, vitamins A and D, and hydroxyproline, on burn wound healing in rats. Acute dermal toxicity tests confirmed its nontoxicity. Wistar rats were divided into five groups: a control, a positive control treated with silver sulfadiazine 1% (SSD), and three groups treated with 3%, 9%, and 27% halibut oil cream Formulation (HBOF). The SSD and HBOF groups showed significant healing improvements compared to the control. Histopathological analysis indicated increased collagen production in the HBOF groups, suggesting halibut oil cream's potential as a topical treatment for burn wounds.

The Use of Extracellular Vesicles in Achilles Tendon Repair: A Systematic Review

Achilles tendon (AT) pathologies are common musculoskeletal conditions that can significantly impair function. Despite various traditional treatments, recovery is often slow and may not restore full functionality. The use of extracellular vesicles (EVs) has emerged as a promising therapeutic option due to their role in cell signaling and tissue regeneration. This systematic review aims to consolidate current in vivo animal study findings on the therapeutic effects of EVs on AT injuries. An extensive literature search was conducted using the PubMed, Scopus, and Embase databases for in vivo animal studies examining the effects of EVs on AT pathologies. The extracted variables included but were not limited to the study design, type of EVs used, administration methods, efficacy of treatment, and proposed therapeutic mechanisms. After screening, 18 studies comprising 800 subjects were included. All but one study reported that EVs augmented wound healing processes in the AT. The most proposed mechanisms through which this occurred were gene regulation of the extracellular matrix (ECM), the enhancement of macrophage polarization, and the delivery of therapeutic microRNAs to the injury site. Further research is warranted to not only explore the therapeutic potential of EVs in the context of AT pathologies, but also to establish protocols for their clinical application.

Effects of dose-dependent chronic caffeine consumption in a rat burn wound model: Histopathological and immunohistochemical evaluation

Objectives

Using histopathological and immunohistochemical methods, we aimed to examine the dose-dependent effects of chronic caffeine consumption on the recovery of burn wounds in an in vivo rat model.

Materials and Methods

Forty-five rats were randomly assigned to a high-dose group (20 mg/kg per day for eight weeks; n=15), a low-dose group (10 mg/kg per day for eight weeks; n=15), or a control group (n=15). The burn model was created in rats. The groups were separated into three subgroups (n=5) based on the day after injury (7th, 14th, or 21st day). The wound area, wound closure percentage, and histopathological and immunohistochemical reactivity were evaluated.

Results

Successful wound healing was noted in rats treated with low doses of caffeine, similar to the control group. Pathology revealed low re-epithelization, low inflammation, and high granulation in the high-dose group. In addition, there was a significant difference between the control and high-dose groups regarding the immunohistochemical reactivity of αVβ3 integrin, vascular endothelial growth factor (VEGF), and matrix metalloproteinase 9 (MMP-9) (P<0.05).

Conclusion

We demonstrated that chronic caffeine consumption in rats adversely affects the recovery process of wounds in a dose-dependent manner. This effect may occur through delayed wound healing via the molecules MMP-9, αVβ3 integrin, and VEGF. Treatment that modulates these molecules can lead to enhanced and quicker recovery of damaged skin in coffee lovers.

Prevention and Treatment of Burn Scar Contracture: A Practical Review

Burn contracture affects close to one-third of all burn patients, leading to significant functional impairment and costs. Effective prevention and treatment strategies are necessary to decrease morbidity and unnecessary costs. This scoping review aimed to summarize prevention and treatment strategies used for management of burn scar contractures published in the literature since 2000. A comprehensive PubMed review was performed in October 2022 to identify methods of burn contracture prevention and treatments. Non-English, duplicate, and unavailable articles were excluded. Data were extracted including publication year, techniques, and outcomes. A total of 327 publications met criteria for inclusion. Most articles were published in 2011 (n = 22). Treatment strategies were discussed in 82.9% of studies, prevention in 16.5%, and both in 0.6%. The most common areas discussed included the upper extremity (n = 127) and neck (n = 102). Flaps were the most frequently used method (n = 208), followed by autografts (n = 89). Most preventative therapies were still in early stages of development. Burn contracture management requires a highly individualized approach with many available reconstructive techniques available. Further research is needed to improve prevention techniques and decrease morbidity and cost to patients.

Stromal cell-derived factor 1 (SDF-1) increases the number of telocytes in ex vivo and in vitro assays

Telocytes are interstitial cells that are present in various tissues, have long cytoplasmic projections known as telopodes, and are classified as CD34+ cells. Telopodes form extensive networks that permeate the stroma, and there is evidence that these networks connect several stromal cell types, giving them an important role in intercellular communication and the maintenance of tissue organisation. Data have also shown that these networks can be impaired and the number of telocytes reduced in association with many pathological conditions such as cancer and fibrosis. Thus, techniques that promote telocyte proliferation have become an important therapeutic target. In this study, ex vivo and in vitro assays were conducted to evaluate the impact on prostatic telocytes of SDF-1, a factor involved in the proliferation and migration of CD34+ cells. SDF-1 caused an increase in the number of telocytes in explants, as well as morphological changes that were possibly related to the proliferation of these cells. These changes involved the fusion of telopode segments, linked to an increase in cell body volume. In vitro assays also showed that SDF-1 enriched prostate stromal cells with telocytes. Altogether, the data indicate that SDF-1 may offer promising uses in therapies that aim to increase the number of telocytes. However, further studies are needed to confirm the efficiency of this factor in different tissues/pathological conditions.

3D-Printed Gelatin Methacrylate Scaffolds with Controlled Architecture and Stiffness Modulate the Fibroblast Phenotype towards Dermal Regeneration

Impaired skin wound healing due to severe injury often leads to dysfunctional scar tissue formation as a result of excessive and persistent myofibroblast activation, characterised by the increased expression of α-smooth muscle actin (αSMA) and extracellular matrix (ECM) proteins. Yet, despite extensive research on impaired wound healing and the advancement in tissue-engineered skin substitutes, scar formation remains a significant clinical challenge. This study aimed to first investigate the effect of methacrylate gelatin (GelMA) biomaterial stiffness on human dermal fibroblast behaviour in order to then design a range of 3D-printed GelMA scaffolds with tuneable structural and mechanical properties and understand whether the introduction of pores and porosity would support fibroblast activity, while inhibiting myofibroblast-related gene and protein expression. Results demonstrated that increasing GelMA stiffness promotes myofibroblast activation through increased fibrosis-related gene and protein expression. However, the introduction of a porous architecture by 3D printing facilitated healthy fibroblast activity, while inhibiting myofibroblast activation. A significant reduction was observed in the gene and protein production of αSMA and the expression of ECM-related proteins, including fibronectin I and collagen III, across the range of porous 3D-printed GelMA scaffolds. These results show that the 3D-printed GelMA scaffolds have the potential to improve dermal skin healing, whilst inhibiting fibrosis and scar formation, therefore potentially offering a new treatment for skin repair.

RETRACTED: Healing potential of Spirulina platensis for skin wounds by modulating bFGF, VEGF, TGF-ß1 and α-SMA genes expression targeting angiogenesis and scar tissue formation in the rat model

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. The journal was alerted to an associated PubPeer post in which suspected duplicated features were identified within Figure 4 B1, and the histological image in Figure 3 A1 appears to have been previously published in another article, as detailed here: https://pubpeer.com/publications/E5658B7B735FF993AA795A5F14C086. The journal performed independent analysis and identified additional suspected image duplications between the images of mice in Figure 1 A+B and images of mice in Figure 6 A+B from Elbialy et al., BMC Veterinary Research (2020). The journal requested the authors provide an explanation to these concerns and associated raw data, but this request was not satisfactorily fulfilled. The Editor-in-Chief assessed the case and decided to retract the article.

Hypoxia Mesenchymal Stem Cells Accelerate Wound Closure Improvement by Controlling α-smooth Muscle actin Expression in the Full-thickness Animal Model

BACKGROUND: The active myofibroblast producing extracellular matrix deposition regarding wound closure is characterized by alpha-smooth muscle actin (α-SMA) expression. However, the persistence of α-SMA expression due to prolonged inflammation may trigger scar formation. A new strategy to control α-SMA expression in line with wound closure improvement uses hypoxic mesenchymal stem cells (HMSCs) due to their ability to firmly control inflammation for early initiating cell proliferation, including the regulation of α-SMA expression associated with wound closure acceleration. AIM: This study aimed to explore the role of HMSCs in accelerating the optimum wound closure percentages through controlling the α-SMA expression. MATERIALS AND METHODS: Twenty-four full-thickness rats wound model were randomly divided into four groups: Sham (Sh), Control (C) by NaCl administration only, and two treatment groups by HMSCs at doses of 1.5×106 cells (T1) and HMSCs at doses of 3×106 cells (T2). HMSCs were incubated under hypoxic conditions. The α-SMA expression was analyzed under immunohistochemistry staining assay, and the wound closure percentage was analyzed by ImageJ software. RESULTS: This study showed a significant increase in wound closure percentage in all treatment groups that gradually initiated on days 6 and 9 (p < 0.05). In line with the increase of wound closure percentages on day 9, there was also a significant decrease in α-SMA expression in all treatment groups (p < 0.05), indicating the optimum wound healing has preceded. CONCLUSION: HMSCs have a robust ability to accelerated wound closure improvement to the optimum wound healing by controlling α-SMA expression depending on wound healing phases.

A possible role for inducible arginase isoform (AI) in the pathogenesis of chronic venous leg ulcer

Chronic venous ulcer (CVU) is a major cause of chronic wounds of lower extremities and presents a significant financial and resource burden to health care systems worldwide. Defects in the vasculature, matrix deposition, and re-epithelialization are the main histopathological changes believed to impede healing. Supplementation of the amino acid arginine that plays a crucial role in the interactions that occur during inflammation and wound healing was proven clinically to improve acute wound healing probably through enhancing activity of inducible arginase (AI) locally in the wounds. However, the possible mechanism of arginine action and the potential beneficial effects of AI/arginine in human chronic wounds remain unclear. In the present study, using biopsies, taken under local anesthesia, from adult patients (n = 12, mean age 55 years old) with CVUs in lower extremities, we investigated the correlation between AI distribution in CVUs and the histopathological changes, mainly proliferative and vascular changes. Our results show a distinct spatial distribution of AI along the ulcer in the epidermis and in the dermis with the highest level of expression being at the ulcer edge and the least expression towards the ulcer base. The AI cellular immunoreactivity, enzymatic activity, and protein levels were significantly increased towards the ulcer edge. Interestingly, a similar pattern of expression was encountered in the proliferative and the vascular changes with strong correlations between AI and the proliferative activity and vascular changes. Furthermore, AI cellular distribution was associated with increased proliferative activity, inflammation, and vascular changes. Our findings of differential expression of AI along the CVU base, edge, and nearby surrounding skin and its associations with increased proliferative activity and vascular changes provide further support to the AI implication in CVU pathogenesis. The presence of high levels of AI in the epidermis of chronic wounds may serve as a molecular marker of impaired healing and may provide future targets for therapeutic intervention.

Revisiting the Role of the Myofibroblast in Socket Surgery: An Immunohistochemical Study

PURPOSE

To determine the impact of a single injection of various anti-inflammatory, antimitotic, and antiangiogenic agents on the cell count of myofibroblasts in an eviscerated socket.

METHODS

One eye from 15 skeletally mature New Zealand white rabbits was eviscerated, and the rabbits were divided into 5 groups. Each group of 3 rabbits received a 0.1 ml subconjunctival injection of a different agent. Group I received bevacizumab 25 mg/ml, group II received triamcinolone 40 mg/ml, group III received 5-fluorouracil 50 mg/ml, group IV received mitomycin-C 0.4 mg/ml, while group V was the control group and received no injections. The animals were euthanized 19 days after evisceration and conjunctival samples were submitted for histopathological examination. Monoclonal α-smooth muscle actin antibody was applied, and the mean of 5 readings of the number of myofibroblasts was recorded in each slide.

RESULTS

The mean count of myofibroblasts was highest for the control group and all groups achieved a statistically significant reduction in myofibroblast count compared with the control group. Sorting the means showed that Group IV (mitomycin-C) achieved the lowest mean value (p = 0.000006) followed by triamcinolone (p = 0.00048), while group I (bevacizumab) achieved the least reduction in myofibroblast count (p = 0.00148).

CONCLUSION

Until newer antimyofibroblast medications and antibodies are commercially available, a single injection of mitomycin-C or triamcinolone during surgery achieves the highest mean reduction of myofibroblast count.

Wound healing potential of scaffolds prepared from porcine jejunum and urinary bladder by a non-detergent/enzymatic method

Scaffolds prepared using extracellular matrices of mammalian organs/tissues, when used as grafts, have wound healing potential. This paper evaluated the physical properties and in vivo wound healing potential of jejunum-derived scaffold (JDS) and urinary bladder-derived scaffold (UDS) of porcine origin prepared by a non-detergent/enzymatic method. The former had higher flexural rigidity and suture retention strength compared to the latter, but both of them had the essential flexural rigidity and suture retention strength required for skin grafts. Full thickness skin-wounds on rabbit dorsum were treated with these scaffolds and the wound healing ability was compared by studying histomorphology parameters such as re-epithelialisation, collagen deposition, angiogenesis, proliferation of cells, mesenchymal cell infiltration and myofibroblast response. The extent of these reactions was assessed using histomorphometry. The results indicated that both grafts initiated healing faster than those wounds without any graft, as evidenced by the extent of cell proliferation and mesenchymal cell infiltration. The myofibroblast response persisted longer in the non-graft assisted wound healing reaction compared to the healing in the graft assisted wounds. Moreover, the JDS induced higher cell proliferation and greater angiogenesis than UDS probably indicating better healing by the former. The results suggested that JDS and UDS prepared by non-detergent/enzymatic method have potential clinical applications.

Role of WNT10A-expressing kidney fibroblasts in acute interstitial nephritis

WNT signaling mediates various physiological and pathological processes. We previously showed that WNT10A is a novel angio/stromagenic factor involved in such processes as tumor growth, wound healing and tissue fibrosis. In this study, we investigated the role of WNT10A in promoting the fibrosis that is central to the pathology of acute interstitial nephritis (AIN). We initially asked whether there is an association between kidney function (estimated glomerular filtration rate; eGFR) and WNT10A expression using kidney biopsies from 20 patients with AIN. Interestingly, patients with WNT10A expression had significantly lower eGFR than WNT10A-negative patients. However, changes in kidney function were not related to the level of expression of other WNT family members. Furthermore, there was positive correlation between WNT10A and α-SMA expression. We next investigated the involvement of WNT10A in kidney fibrosis processes using COS1 cells, a kidney fibroblast cell line. WNT10A overexpression increased the level of expression of fibronectin and peroxiredoxin 5. Furthermore, WNT10A overexpression renders cells resistant to apoptosis induced by hydrogen peroxide and high glucose. Collectively, WNT10A may induce kidney fibrosis and associate with kidney dysfunction in AIN.

Immunohistochemical monitoring of wound healing in antibiotic treated Buruli ulcer patients

Background

While traditionally surgery has dominated the clinical management of Buruli ulcer (BU), the introduction of the combination chemotherapy with oral rifampicin and intramuscular streptomycin greatly improved treatment and reduced recurrence rates. However management of the often extensive lesions after successful specific therapy has remained a challenge, in particular in rural areas of the African countries which carry the highest burden of disease. For reasons not fully understood, wound healing is delayed in a proportion of antibiotic treated BU patients. Therefore, we have performed immunohistochemical investigations to identify markers which may be suitable to monitor wound healing progression.

Methodology/Principal findings

Tissue specimens from eight BU patients with plaque lesions collected before, during and after chemotherapy were analyzed by immunohistochemistry for the presence of a set of markers associated with connective tissue neo-formation, tissue remodeling and epidermal activation. Several target proteins turned out to be suitable to monitor wound healing. While α-smooth muscle actin positive myofibroblasts were not found in untreated lesions, they emerged during the healing process. These cells produced abundant extracellular matrix proteins, such as pro-collagen 1 and tenascin and were found in fibronectin rich areas. After antibiotic treatment many cells, including myofibroblasts, revealed an activated phenotype as they showed ribosomal protein S6 phosphorylation, a marker for translation initiation. In addition, healing wounds revealed dermal tissue remodeling by apoptosis, and showed increased cytokeratin 16 expression in the epidermis.

Conclusion/Significance

We have identified a set of markers that allow monitoring wound healing in antibiotic treated BU lesions by immunohistochemistry. Studies with this marker panel may help to better understand disturbances responsible for wound healing delays observed in some BU patients.

Coagulative tissue necrosis and local immunosuppression caused by the M. ulcerans macrolide toxin mycolactone are typical features of Buruli ulcer disease (BU). In particular in BU endemic remote rural areas of West Africa, patients often report with large ulcerated lesions. Despite the availability of an effective dual antimycobacterial antibiotic therapy, some ulcerative lesions may take long time to healing and represent a major burden for the patients as well as for the health system. Proper wound healing is a well-orchestrated process involving numerous cellular and acellular components. Here we have performed immunohistochemical studies with tissue from BU lesions collected before, during and after antibiotic treatment. We identified a set of markers which are appropriate to evaluate formation of granulation tissue (alpha-smooth muscle positive fibroblasts), matrix deposition (pro-collagen 1, fibronectin and tenascin C), cell activation (phosphorylated S6), hyper proliferation of the epidermis (cytokeratin 16) and apoptosis (cleaved caspase 3) during wound healing. These markers may become suitable for assessing progression of tissue repair and for investigating the functional basis of impaired wound healing.

Moist exposed burn ointment promotes cutaneous excisional wound healing in rats involving VEGF and bFGF

Cutaneous delayed wounds are a challenging clinical problem, and vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) exhibit key roles in wound healing. Moist exposed burn ointment (MEBO), a Chinese burn ointment with a USA patented formulation, has been reported to promote chronic ischemic and neurogenic ulcer healing in patients; however, the underlying mechanisms remain unclear. In the present study, MEBO significantly promoted the formation of granulation tissue in cutaneous excisional wounds, shortened the time of wound healing, and increased neovascularization and the number of fibroblasts. Furthermore, as well as enhancing the protein expression, MEBO application also increased the gene expression of VEGF and bFGF. The results indicate that MEBO promotes cutaneous excisional wound healing by at least partially enhancing VEGF and bFGF production, implicating the potential uses of MEBO for delayed cutaneous wound healing.

Propolis modulates vitronectin, laminin, and heparan sulfate/heparin expression during experimental burn healing

OBJECTIVE

This study was aimed at assessing the dynamics of vitronectin (VN), laminin (LN), and heparan sulfate/heparin (HS/HP) content changes during experimental burn healing.

METHODS

VN, LN, and HS/HP were isolated and purified from normal and injured skin of domestic pigs, on the 3rd, 5th, 10th, 15th, and 21st days following thermal damage. The wounds were treated with apitherapeutic agent (propolis), silver sulfadiazine (SSD), physiological salt solution, and propolis vehicle. VN and LN were quantified using an immunoenzymatic assay and HS/HP was estimated by densitometric analysis.

RESULTS

Propolis treatment stimulated significant increases in VN, LN, and HS/HP contents during the initial phase of study, followed by a reduction in the estimated extracellular matrix molecules. Similar patterns, although less extreme, were observed after treatment with SSD.

CONCLUSIONS

The beneficial effects of propolis on experimental wounds make it a potential apitherapeutic agent in topical burn management.

Propolis Modifies Collagen Types I and III Accumulation in the Matrix of Burnt Tissue

Wound healing represents an interactive process which requires highly organized activity of various cells, synthesizing cytokines, growth factors, and collagen. Collagen types I and III, serving as structural and regulatory molecules, play pivotal roles during wound healing. The aim of this study was to compare the propolis and silver sulfadiazine therapeutic efficacy throughout the quantitative and qualitative assessment of collagen types I and III accumulation in the matrix of burnt tissues. Burn wounds were inflicted on pigs, chosen for the evaluation of wound repair because of many similarities between pig and human skin. Isolated collagen types I and III were estimated by the surface plasmon resonance method with a subsequent collagenous quantification using electrophoretic and densitometric analyses. Propolis burn treatment led to enhanced collagens and its components expression, especially during the initial stage of the study. Less expressed changes were observed after silver sulfadiazine (AgSD) application. AgSD and, with a smaller intensity, propolis stimulated accumulation of collagenous degradation products. The assessed propolis therapeutic efficacy, throughout quantitatively and qualitatively analyses of collagen types I and III expression and degradation in wounds matrix, may indicate that apitherapeutic agent can generate favorable biochemical environment supporting reepithelization.

The anti-scar effects of basic fibroblast growth factor on the wound repair in vitro and in vivo

Hypertrophic scars (HTS) and keloids are challenging problems. Their pathogenesis results from an overproduction of fibroblasts and excessive deposition of collagen. Studies suggest a possible anti-scarring effect of basic fibroblast growth factor (bFGF) during wound healing, but the precise mechanisms of bFGF are still unclear. In view of this, we investigated the therapeutic effects of bFGF on HTS animal model as well as human scar fibroblasts (HSF) model. We show that bFGF promoted wound healing and reduced the area of flattened non-pathological scars in rat skin wounds and HTS in the rabbit ear. We provide evidence of a new therapeutic strategy: bFGF administration for the treatment of HTS. The scar elevation index (SEI) and epidermal thickness index (ETI) was also significantly reduced. Histological reveal that bFGF exhibited significant amelioration of the collagen tissue. bFGF regulated extracellular matrix (ECM) synthesis and degradation via interference in the collagen distribution, the α-smooth muscle actin (α-SMA) and transforming growth factor-1 (TGF-β1) expression. In addition, bFGF reduced scarring and promoted wound healing by inhibiting TGFβ1/SMAD-dependent pathway. The levels of fibronectin (FN), tissue inhibitor of metalloproteinase-1 (TIMP-1) collagen I, and collagen III were evidently decreased, and matrix metalloproteinase-1 (MMP-1) and apoptosis cells were markedly increased. These results suggest that bFGF possesses favorable therapeutic effects on hypertrophic scars in vitro and in vivo, which may be an effective cure for human hypertrophic scars.

The role of tumour stroma in colorectal cancer invasion and metastasis

Colorectal cancer (CRC) is a major cause of mortality in western society with a 5-year survival of approximately 50%. Metastasis to the liver and lungs is the principal cause of death and occurs in up to 25% of patients at presentation. Despite advances in available techniques for treating metastases, the majority of patients remain incurable and existing adjuvant therapies such as chemotherapy are only of limited effectiveness. Understanding the molecular mechanisms underlying the metastatic process may allow us to identify those at greatest risk of recurrence and discover new tumour targets to prevent disease progression. It is now apparent that tumour stroma plays an important role in promoting tumour progression. A pronounced desmoplastic reaction was associated with a reduced immune response and has been shown to be an independent poor prognostic indicator in CRC and cancer recurrence. Determining the cause(s) and effect(s) of this stromal response will further our understanding of tumour cell/stromal interactions, and will help us identify prognostic indicators for patients with CRC. This will not only allow us to target our existing treatments more effectively, we also aim to identify novel and more specific therapeutic targets for the treatment of CRC which will add to our current therapeutic options.