Increased expression of collagen types I and III in human skin as a consequence of radiotherapy

Effect of the gut microbiota on the expression of genes that are important for maintaining skin function: Analysis using aged mice

The gut microbiota changes greatly at the onset of disease, and the importance of intestinal bacteria has been highlighted. The gut microbiota also changes greatly with aging. Aging causes skin dryness, but it is not known how changes in the gut microbiota with aging affects the expression of genes that are important for maintaining skin function. In this study, we investigated how age-related changes in gut microbiota affect the expression of genes that regulate skin function. The gut microbiotas from young mice and aged mice were transplanted into germ-free mice (fecal microbiota transplantation [FMT]). These recipient mice were designated FMT-young mice and FMT-old mice respectively, and the expression levels of genes important for maintaining skin function were analyzed. The dermal water content was significantly lower in old mice than that in young mice, indicating dry skin. The gut microbiota significantly differed between old mice and young mice. The water channel aquaporin-3 (Aqp3) expression level in the skin of FMT-old mice was significantly higher than that in FMT-young mice. In addition, among the genes that play an important role in maintaining skin function, the expression levels of those encoding ceramide-degrading enzyme, ceramide synthase, hyaluronic acid-degrading enzyme, and Type I collagen were also significantly higher in FMT-old mice than in FMT-young mice. It was revealed that the gut microbiota, which changes with age, regulates the expression levels of genes related to skin function, including AQP3.

Expression analysis of genes important for maintaining skin function in a senescence-accelerated mouse prone model

AIM

Senescence-accelerated mouse prone (SAMP) mice can reproduce the same conditions as normal aging mice in a short period. Although SAMP mice have been widely used in aging research, research on skin function in SAMP mice is lacking. In this study, to investigate the skin function of SAMP mice, we analyzed the expression of genes important for maintaining skin function.

METHODS

Eight-month-old SAMP mice and senescence-accelerated mouse resistant (SAMR) mice with normal aging were used. The expression levels of various functional genes in the skin were analyzed.

RESULTS

The dermal water content of SAMP mice was significantly lower than that of SAMR mice, indicating dry skin. The mRNA expression levels of elastin (Ela), filaggrin (Flg), loricrin (Lor), collagen type I alpha 1 chain (Col1a1) and Col1a2 in the skin of SAMP mice were all significantly decreased compared with those of SAMR mice. Hyaluronan-degrading enzyme (Hyal1) expression levels in SAMP mice were similar to those in SAMR mice, but hyaluronan synthase (Has2) levels were significantly decreased. In addition, the expression level of aquaporin-3 in the skin of SAMP mice was significantly decreased at both the mRNA and protein levels.

CONCLUSIONS

In the skin of SAMP mice, the expression levels of various skin function-regulating genes were decreased, and this phenomenon might cause skin dryness. The SAMP mouse could be a tool for analyzing skin aging. Geriatr Gerontol Int 2023; 23: 951-957.

New 675 nm Laser Device: The Innovative and Effective Non-Ablative Resurfacing Technique

Background and Objectives: Photo/chrono-aging is usually expressed as facial discolouration, wrinkles, redness, elastosis, laxity, and dehydration, thus representing major signs of ageing that often lead to a negative phycological impact on a patient's quality of life. Several types of treatment have been tested during the last decade, especially laser treatments. This article aims to share our experience in the treatment of photoaging with a new 675 nm laser source system on facial chrono-ageing. Materials and Methods: Thirty-five (35) patients were treated with the 675 nm laser device: 32 females (mean age 49 years) and 3 men (mean age 57 years), with Fitzpatrick skin types I-III (9% type I, 43% type II, 48% type III), facial wrinkles and hyperpigmented spots. The efficacy of this treatment was assessed using the Modified Fitzpatrick Wrinkles Scale (FWS), which was calculated before starting the treatment and after 6 months. The pain was evaluated using the VAS Pain Scale. Results: All 35 patients showed a significant improvement in facial wrinkles according to the FWS (from 1.96 to 1.73 at the 3-month follow-up, up to a value of 1.43 at 6 months). In a small group of patients, it was observed that 44% of them showed vascular moderate improvement and that 13% showed a vascular marked improvement after treatment. No side effects were detected except a mild erythematous rash in two patients, and the VAS Pain scale was assessed at 1.17. Conclusions: Red Touch allows a uniform and stable result to be achieved over time with minimum discomfort.

Laser emission at 675 nm: In vitro study evidence of a promising role in skin rejuvenation

Light-based therapies have been proven to influence and perhaps reverse skin ageing at clinical, molecular and histologic levels. Laser technology decreases photodamage by promoting collagen type I and III synthesis and enhancing the expression of heat shock protein. Aims: This study aims to assess different doses of 675 nm irradiation on human dermal fibroblast cells to evaluate the potential therapeutic effects on the rejuvenation process. Methods: This study employed a laser system that emits 675 nm wavelength: 260, 390, 520 and 650 J/cm² doses were tested on adult human dermal fibroblast cells. Cellular viability, proliferation, and synthesis of type I and III collagen were studied. Results: No dose tested showed effects on cell viability and proliferation at 24 and 48 h from the irradiation. Doses of 260 and 520 J/cm² causes a significant decrease in type I collagen fluorescence intensity, while 390 J/cm² elicits a significant increase in type III collagen expression. Conclusions: Our results showed that 675 nm laser irradiation does not affect cell viability while modulating cell proliferation and collagen synthesis in human adult cultured fibroblasts in vitro. These findings suggest that 675 nm laser irradiation potentially plays a role in skin rejuvenation.

Advancements in Extracellular Matrix-Based Biomaterials and Biofabrication of 3D Organotypic Skin Models

Over the last decades, three-dimensional (3D) organotypic skin models have received enormous attention as alternative models to in vivo animal models and in vitro two-dimensional assays. To date, most organotypic skin models have an epidermal layer of keratinocytes and a dermal layer of fibroblasts embedded in an extracellular matrix (ECM)-based biomaterial. The ECM provides mechanical support and biochemical signals to the cells. Without advancements in ECM-based biomaterials and biofabrication technologies, it would have been impossible to create organotypic skin models that mimic native human skin. In this review, the use of ECM-based biomaterials in the reconstruction of skin models, as well as the study of complete ECM-based biomaterials, such as fibroblasts-derived ECM and decellularized ECM as a better biomaterial, will be highlighted. We also discuss the benefits and drawbacks of several biofabrication processes used in the fabrication of ECM-based biomaterials, such as conventional static culture, electrospinning, 3D bioprinting, and skin-on-a-chip. Advancements and future possibilities in modifying ECM-based biomaterials to recreate disease-like skin models will also be highlighted, given the importance of organotypic skin models in disease modeling. Overall, this review provides an overview of the present variety of ECM-based biomaterials and biofabrication technologies available. An enhanced organotypic skin model is expected to be produced in the near future by combining knowledge from previous experiences and current research.

Potential of Biofermentative Unsulfated Chondroitin and Hyaluronic Acid in Dermal Repair

Chondroitin obtained through biotechnological processes (BC) shares similarities with both chondroitin sulfate (CS), due to the dimeric repetitive unit, and hyaluronic acid (HA), as it is unsulfated. In the framework of this experimental research, formulations containing BC with an average molecular size of about 35 KDa and high molecular weight HA (HHA) were characterized with respect to their rheological behavior, stability to enzymatic hydrolysis and they were evaluated in different skin damage models. The rheological characterization of the HHA/BC formulation revealed a G’ of 92 ± 3 Pa and a G″ of 116 ± 5 Pa and supported an easy injectability even at a concentration of 40 mg/mL. HA/BC preserved the HHA fraction better than HHA alone. BTH was active on BC alone only at high concentration. Assays on scratched keratinocytes (HaCaT) monolayers showed that all the glycosaminoglycan formulations accelerated cell migration, with HA/BC fastening healing 2-fold compared to the control. In addition, in 2D HaCaT cultures, as well as in a 3D skin tissue model HHA/BC efficiently modulated mRNA and protein levels of different types of collagens and elastin remarking a functional tissue physiology. Finally, immortalized human fibroblasts were challenged with TNF-α to obtain an in vitro model of inflammation. Upon HHA/BC addition, secreted IL-6 level was lower and efficient ECM biosynthesis was re-established. Finally, co-cultures of HaCaT and melanocytes were established, showing the ability of HHA/BC to modulate melanin release, suggesting a possible effect of this specific formulation on the reduction of stretch marks. Overall, besides demonstrating the safety of BC, the present study highlights the potential beneficial effect of HHA/BC formulation in different damage dermal models.

Three-dimensional bioprinting of a full-thickness functional skin model using acellular dermal matrix and gelatin methacrylamide bioink

Treatment of full-thickness skin defects still presents a significant challenge in clinical practice. Three-dimensional (3D) bioprinting technique offers a promising approach for fabricating skin substitutes. However, it is necessary to identify bioinks that have both sufficient mechanical properties and desirable biocompatibilities. In this study, we successfully fabricated acellular dermal matrix (ADM) and gelatin methacrylamide (GelMA) bioinks. The results demonstrated that ADM preserved the main extracellular matrix (ECM) components of the skin and GelMA had tunable mechanical properties. Both bioinks with shear-thinning properties were suitable for 3D bioprinting and GelMA bioink exhibited high printability. Additionally, the results revealed that 20% GelMA with sufficient mechanical properties was suitable to engineer epidermis, 1.5% ADM and 10% GelMA displayed relatively good cytocompatibilities. Here, we proposed a new 3D structure to simulate natural full-thickness skin, which included 20% GelMA with HaCaTs as an epidermal layer, 1.5% ADM with fibroblasts as the dermis, and 10% GelMA mesh with human umbilical vein endothelial cells (HUVECs) as the vascular network and framework. We demonstrated that this 3D bioprinting functional skin model (FSM) could not only promote cell viability and proliferation, but also support epidermis reconstruction in vitro. When transplanted in vivo, the FSM could maintain cell viability for at least 1 week. Furthermore, the FSM promoted wound healing and re-epithelization, stimulated dermal ECM secretion and angiogenesis, and improved wound healing quality. The FSM may provide viable functional skin substitutes for future clinical applications. STATEMENT OF SIGNIFICANCE: We propose a new 3D structure to simulate natural full-thickness skin, which included 20% GelMA with HaCaTs as an epidermal layer, 1.5% ADM with fibroblasts as the dermis, and 10% GelMA mesh with HUVECs as the vascular network. It could not only maintain a moist microenvironment and barrier function, but also recreate the natural skin microenvironment to promote cell viability and proliferation. This may provide viable functional skin substitutes for future clinical applications.

Transformation of acellular dermis matrix with dicalcium phosphate into 3D porous scaffold for bone regeneration

Animal derived biomaterials have attracted much attentions in treating large size bone defect due to their excellent biocompatibility and potent bioactivities offered by the biomacromolecules and growth factors contained in these materials. Dermis-derived matrix (ADM) has been used as skin grafts and wound dressings for decades, however its application in bone tissue engineering has been largely limited as ADM possesses a dense structure which does not support bone tissue ingrowth. Recently, we have successfully fabricated porous scaffold structure using an ADM with the aid of micronization technique. When integrated with inorganic components such as calcium phosphate, ADM could be transformed to bone graft substitutes with desirable osteogenic properties. While purified and chemically cross-linked collagen has lost its natural structure, our ADM successfully preserved natural tropocollagen structure, as well as other bioactive components. A composite scaffold was fabricated by incorporating dicalcium phosphate (DCP) microparticles into ADM microfibers and freeze-dried to form a highly porous structure. Unlike conventional ADM materials, this scaffold possesses high porosity with interconnected pores. More importantly, our evaluation data demonstrated that it performed much more effective in treating critical bone defects in comparison with best commercial product on the market. In a head-to-head comparison with a commercial bone graft material Bongold^®, the ADM/DCP scaffold showed superior osteogenic capacity by filling the defect with well-organized new bone tissue in a rabbit radius segmental defect model. Put together, our results exhibited a novel bone graft substitute was developed by circumventing processing barriers associated with natural ADM, which offers another novel bone graft substitute for bone regeneration.

Second harmonic generation light quantifies the ratio of type III to total (I + III) collagen in a bundle of collagen fiber

The ratio of type III to type I collagen is important for properly maintaining functions of organs and cells. We propose a method to quantify the ratio of type III to total (type I + III) collagen (λ_III) in a given collagen fiber bundle using second harmonic generation (SHG) light. First, the relationship between SHG light intensity and the λ_III of collagen gels was examined, and the slope (k₁) and SHG light intensity at 0% type III collagen (k₂) were determined. Second, the SHG light intensity of a 100% type I collagen fiber bundle and its diameter (D) were measured, and the slope (k₃) of the relationship was determined. The λ_III in a collagen fiber bundle was estimated from these constants (k_1-3) and SHG light intensity. We applied this method to collagen fiber bundles isolated from the media and adventitia of porcine thoracic aortas, and obtained λ_III = 84.7% ± 13.8% and λ_III = 17.5% ± 15.2%, respectively. These values concurred with those obtained with a typical quantification method using sodium dodecyl sulfate–polyacrylamide gel electrophoresis. The findings demonstrated that the method proposed is useful to quantify the ratio of type III to total collagen in a collagen fiber bundle.

Knockdown of Dual Oxidase 1 (DUOX1) Promotes Wound Healing by Regulating Reactive Oxygen Species (ROS) by Activation of Nuclear Kactor kappa B (NF-κB) Signaling

Background

The aim of this study was to evaluate the potential role of dual oxidase 1 (DUOX1) in wound healing.

Material/Methods

Primary fibroblasts were isolated from wound granulation tissue. Fibroblasts cell lines were established using DUOX1 overexpression and interference. Cell proliferation and reactive oxygen species (ROS) production were measured and compared among the groups.

Results

DUOX1 expression was highest in the slow-healing tissues (P<0.05). Knockdown of DUOX1 significantly increased cell proliferation and inhibited ROS production and cell apoptosis (P<0.01). Moreover, expression of malondialdehyde (MDA) was significantly reduced, while expression of superoxide dismutase (SOD) expression was significantly increased (P<0.01). In addition, DUOX1 silencing significantly upregulated collagen I, collagen III, and NF-κB protein levels in the cytoplasm, and inhibited the protein levels of P21, P16, and NF-κB in the nucleus (P<0.01). Overexpression of DUOX1 caused a reverse reaction mediated by knockdown of DUOX1. When DUOX1-overexpressing cells were treated with the ROS inhibitor N-acetyl-L-cysteine (NAC), the protein levels that were increased by DUOX1 overexpression were reversed.

Conclusions

These results suggest that knockdown of DUOX1 significantly benefits wound healing, likely by the regulation of oxidative stress via NF-κB pathway activation.

Risk Factors for Skin Tears Following Collagenase Clostridium histolyticum to Treat Dupuytren Contractures

PURPOSE

Skin tears are an unpleasant complication that may occur after collagenase Clostridium histolyticum (CCH) administration to treat Dupuytren contractures of the fingers. The purpose of this study was to determine risk factors for the development of this complication.

METHODS

Over a 6-year period, patients with a measurable metacarpophalangeal or proximal interphalangeal joint Dupuytren contracture and a palpable cord treated with CCH were prospectively observed. Patients were assessed for the development of skin tears immediately on the day of manipulation as well 30 days or more after manipulation.

RESULTS

A total of 117 patients (174 cords) met inclusion criteria. There was a 25.6% incidence of skin tears (30 of 117 patients; 33 skin tears). Multivariable regression analysis revealed that patients with a combined digital flexion contracture (total combined metacarpophalangeal, proximal interphalangeal, and distal interphalangeal joint contracture) of 75° and greater and those treated with 2 simultaneous doses of CCH in the same hand were more likely to sustain a tear. All skin tears healed with nonsurgical management at short-term follow-up.

CONCLUSIONS

Although a relatively minor complication, skin tears are not well-tolerated by all patients and may change the postinjection course of orthosis use, wound care, and manual activity. Based on these results, patients with digital contractures 75° or greater and those treated with 2 simultaneous doses of CCH in the same hand may be counseled that they have a higher likelihood of developing a skin tear during manipulation. Pretreatment education may reduce anxiety experienced by patients who otherwise unexpectedly develop a skin tear at the time of manipulation.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic II.

Type I Collagen Suspension Induces Neocollagenesis and Myodifferentiation in Fibroblasts In Vitro

The ability of a collagen-based matrix to support cell proliferation, migration, and infiltration has been reported; however, the direct effect of an aqueous collagen suspension on cell cultures has not been studied yet. In this work, the effects of a high-concentration aqueous suspension of a micronized type I equine collagen (EC-I) have been evaluated on a normal mouse fibroblast cell line. Immunofluorescence analysis showed the ability of EC-I to induce a significant increase of type I and III collagen levels, parallel with overexpression of crucial proteins in collagen biosynthesis, maturation, and secretion, prolyl 4-hydroxylase (P4H) and heat shock protein 47 (HSP47), as demonstrated by western blot experiments. The treatment led, also, to an increase of α-smooth muscle actin (α-SMA) expression, evaluated through western blot analysis, and cytoskeletal reorganization, as assessed by phalloidin staining. Moreover, scanning electron microscopy analysis highlighted the appearance of plasma membrane extensions and blebbing of extracellular vesicles. Altogether, these results strongly suggest that an aqueous collagen type I suspension is able to induce fibroblast myodifferentiation. Moreover, our findings also support in vitro models as a useful tool to evaluate the effects of a collagen suspension and understand the molecular signaling pathways possibly involved in the effects observed following collagen treatment in vivo.

Upper body motor function and swallowing impairments and its association in survivors of head and neck cancer: A cross-sectional study

Background

Upper body motor function and swallowing may be affected after curative treatment for head and neck cancer. The aims of this study are to compare maximum mouth opening (MMO), temporomandibular dysfunction (TMD), cervical and shoulder active range of motion (AROM) and strength, and swallowing difficulty between survivors of head and neck cancer (sHNC) and healthy matched controls (HMC) and to examine the correlations between these outcomes in sHNC.

Methods

Thirty-two sHNC and 32 HMC participated on the study. MMO, TMD, cervical and shoulder AROM, cervical and shoulder strength, the SPADI shoulder pain and disability indices, the Eating Assessment Tool (EAT-10) score, swallowing difficulty as determined using a visual analogue scale (VAS), and the location of disturbances in swallowing, were recorded.

Results

MMO and cervical and shoulder AROM and strength were significantly lower in sHNC, whereas FAI, SPADI score, EAT-10 and VAS were higher. The MMO, TMD, cervical and shoulder AROM, and cervical shoulder strength values showed significant correlations (some direct, others inverse) with one another. Swallowing difficulty was inversely associated with the MMO, cervical AROM and shoulder strength.

Conclusion

Compared with controls, sHNC present smaller MMO, lower cervical and shoulder AROM, lower cervical and shoulder strength and higher perception of TMD, shoulder pain and disability and swallowing difficulty. sHNC suffer impaired swallowing related to lower MMO, presence of TMD, cervical AROM and shoulder strength values. Improving these variables via physiotherapy may reduce the difficulty in swallowing experienced by some sHNC.

The Ex Vivo Skin Model as an Alternative Tool for the Efficacy and Safety Evaluation of Topical Products

The development of alternative approaches for safety and efficacy testing that avoid the use of animals is a worldwide trend, which relies on the improvement of current models and tools so that they better reproduce human biology. Human skin from elective plastic surgery is a promising experimental model to test the effects of topically applied products. As the structure of native skin is maintained, including cell population (keratinocytes, melanocytes, Langerhans cells and fibroblasts) and dermal matrix (containing collagen, elastin, glycosaminoglycans, etc.), it most closely matches the effects of substances on in vivo human skin. In this review, we present a collection of results that our group has generated over the last years, involving the use of human skin and scalp explants, demonstrating the feasibility of this model. The development of a test system with ex vivo skin explants, of standard size and thickness, and cultured at the air–liquid interface, can provide an important tool for understanding the mechanisms involved in several cutaneous disorders.

Successful Immediate Staged Breast Reconstruction with Intermediary Autologous Lipotransfer in Irradiated Patients

As indications for radiotherapy in mastectomized patients grow, the need for greater reconstructive options is critical. Preliminary research suggests an ameliorating impact of lipotransfer on irradiated patients with expander-to-implant reconstruction. Herein, we present our technique using lipotransfer during the expansion stage to facilitate implant placement.

Hernia and Cancer: The Points Where the Roads Intersect

Introduction: This review aimed to present common points, intersections, and potential interactions or mutual effects for hernia and cancer. Besides direct relationships, indirect connections, and possible involvements were searched. Materials and Methods: A literature search of PubMed database was performed in July 2018 as well as a search of relevant journals and reference lists. The total number of screened articles was 1,422. Some articles were found in multiple different searches. A last PubMed search was performed during manuscript writing in December 2018 to update the knowledge. Eventually 427 articles with full text were evaluated, and 264 included, in this review. Results: There is no real evidence for a possible common etiology for abdominal wall hernias and any cancer type. The two different diseases had been found to have some common points in the studies on genes, integrins, and biomarkers, however, to date no meaningful relationship has been identified between these points. There is also some, albeit rather conflicting, evidence for inguinal hernia being a possible risk factor for testicular cancer. Neoadjuvant or adjuvant therapeutic modalities like chemotherapy and radiotherapy may cause postoperative herniation with their adverse effects on tissue repair. Certain specific substances like bevacizumab may cause more serious complications and interfere with hernia repair. There are only two articles in PubMed directly related to the topic of "hernia and cancer." In one of these the authors claimed that there was no association between cancer development and hernia repair with mesh. The other article reported two cases of squamous-cell carcinoma developed secondary to longstanding mesh infections. Conclusion: As expected, the relationship between abdominal wall hernias and cancer is weak. Hernia repair with mesh does not cause cancer, there is only one case report on cancer development following a longstanding prosthetic material infections. However, there are some intersection points between these two disease groups which are worthy of research in the future.

A Comparative In Vivo Study on Three Treatment Approaches to Applying Topical Botulinum Toxin A for Crow's Feet

Objective

To evaluate the efficacy and safety of three treatment approaches to applying Botulinum Toxin Type A (BoNTA) for crow's Feet.

Methods

Thirty female subjects with moderate-to-severe crow's feet were included in this comparative in vivo study. They were randomly divided into three groups, including the local intramuscular, intradermal microdroplet injection, and nanomicroneedle delivered with BoNTA therapy group. After one session, evaluations were done at the time points of weeks one, four, and twelve after the treatment. The assessments included subjective satisfaction, blinded clinical assessment, and the biophysical parameters (skin collagen content, elasticity, hydration, and sebum contents).

Results

For dynamic wrinkles, intramuscular injection and intradermal microdroplets injection were more effective than nanomicroneedles. For static wrinkles, nanomicroneedles and intradermal microdroplets injection were more effective. However, the intramuscular injection had no significant effect on static wrinkles. At one week and four weeks after the treatment, the skin elasticity, collagen content, and hydration of nanomicroneedle group and intradermal microdroplet group increased more significantly than those of the intramuscular injection group; at twelve weeks after the treatment, the skin elasticity, collagen content, and hydration of intradermal microdroplet group were higher than those of other two groups. However we observed no statistically significant difference in sebum content between the three groups before and after the treatment.

Conclusion

BoNTA delivered through nanomicroneedles and intradermal microdroplets injection can effectively treat crow's feet. This trial is registered with [2016]KY018-01, registered 16 Feb 2016.

Radiation-Induced Transformation of Immunoregulatory Networks in the Tumor Stroma

The implementation of novel cancer immunotherapies in the form of immune checkpoint blockers represents a major advancement in the treatment of cancer, and has renewed enthusiasm for identifying new ways to induce antitumor immune responses in patients. Despite the proven efficacy of neutralizing antibodies that target immune checkpoints in some refractory cancers, many patients do not experience therapeutic benefit, possibly owing to a lack of antitumor immune recognition, or to the presence of dominant immunosuppressive mechanisms in the tumor microenvironment (TME). Recent developments in this field have revealed that local radiotherapy (RT) can transform tumors into in situ vaccines, and may help to overcome some of the barriers to tumor-specific immune rejection. RT has the potential to ignite tumor immune recognition by generating immunogenic signals and releasing neoantigens, but the multiple immunosuppressive forces in the TME continue to represent important barriers to successful tumor rejection. In this article, we review the radiation-induced changes in the stromal compartments of tumors that could have an impact on tumor immune attack. Since different RT regimens are known to mediate strikingly different effects on the multifarious elements of the tumor stroma, special emphasis is given to different RT schedules, and the time after treatment at which the effects are measured. A better understanding of TME remodeling following specific RT regimens and the window of opportunity offered by RT will enable optimization of the design of novel treatment combinations.

Pirfenidone reduces profibrotic responses in human dermal myofibroblasts, in vitro

Pirfenidone (PFD) is a synthetic small molecule inhibitor with demonstrated anti-inflammatory and antifibrotic properties in vitro and in vivo. The exact mechanism(s) of PFD action remain unclear, due in part to the broad effects of this drug on the complex processes involved in inflammation and fibrosis. While PFD is FDA-approved for the treatment of idiopathic pulmonary fibrosis, the efficacy of this compound for the treatment of dermal fibrosis has not yet been fully characterized. Dermal fibrosis is the pathological formation of excess fibrous connective tissue of the skin, usually the result of traumatic cutaneous injury. Fibroproliferative scarring, caused by delayed wound healing and prolonged inflammation, remains a major clinical concern with considerable morbidity. Despite efforts to identify a therapeutic that targets the fibrotic pathways involved in wound healing to mitigate scar formation, no satisfactory dermal antifibrotic has yet been identified. We aim to better elucidate the antifibrotic mechanism(s) of PFD activity using an in vitro model of dermal fibrosis. Briefly, cultured human dermal fibroblasts were stimulated with TGF-β1 to induce differentiation into profibrotic myofibroblast cells. A dose-dependent reduction in cellular proliferation and migration was observed in TGF-β1-stimulated cells when treated with PFD. We observed a clear inhibition in the development of essential myofibroblast mechanoregulatory machinery, including contractile F-actin stress fibers containing α-SMA and large super-mature focal adhesions. PFD treatment significantly reduced protein levels of major ECM components type I and type III collagen. PFD targeted the p38 MAPK signaling pathway and mitigated profibrotic gene expression profiles. This in vitro data promotes PFD as a potential therapeutic agent for the treatment of dermal fibrosis.

A bioartificial dermal regeneration template promotes skin cell proliferation in vitro and enhances large skin wound healing in vivo

A novel bioartificial dermal regeneration template has been developed using platelet-rich plasma and acellular animal skin collagen sponge for the treatment of larger area and full thickness skin wounds. This platelet-rich plasma-collagen sponge keeps native skin structure and contains huge amounts of growth factors. The effect of this bioartificial dermal regeneration template was tested in vitro and in vivo via a mimic poor wound healing process by adding collagenase I into cell culture medium or the wound area. The in vitro experimental results indicated that the rat skin cells grew faster and produced more collagen in platelet-rich plasma-collagen sponge with collagenase than those treated either with collagen sponge plus collagenase, or collagenase, or control group without treatment. The in vivo experiments were performed by large rat skin wounds, 1.5 cm diameter, treated either with collagenase, or collagenase plus collagen sponge, or collagenase plus platelet-rich plasma-collagen sponge. The wound without treatment was used as a control. The wounds treated with collagenase-containing platelet-rich plasma-collagen sponge healed 4 times faster than the untreated wounds, 6 times faster than the collagenase treated wounds, 2.4 times faster than collagenase-containing collagen sponge treated wounds. The immunostaining indicated that the healed tissues in the wound areas treated with collagenase-containing platelet-rich plasma-collagen sponge were composed of collagen type I and collagen III with blood vessels and hair follicles. The results demonstrated that this collagenase-containing platelet-rich plasma-collagen sponge works as a bioartificial dermal regeneration template. The application of this collagenase-containing platelet-rich plasma-collagen sponge promotes the traumatic skin wound healing and permits the reconstitution of the inherent barrier functions of the skin.

In vivo study of dermal collagen of striae distensae by confocal Raman spectroscopy

This research work mainly deals with studying qualitatively the changes in the dermal collagen of two forms of striae distensae (SD) namely striae rubrae (SR) and striae albae (SA) when compared to normal skin (NS) using confocal Raman spectroscopy. The methodology includes an in vivo human skin study for the comparison of confocal Raman spectra of dermis region of SR, SA, and NS by supervised multivariate analysis using partial least squares discriminant analysis (PLS-DA) to determine qualitatively the changes in dermal collagen. These groups are further analyzed for the extent of hydration of dermal collagen by studying the changes in the water content bound to it. PLS-DA score plot showed good separation of the confocal Raman spectra of dermis region into SR, SA, and NS data groups. Further analysis using loading plot and S-plot indicated the participation of various components of dermal collagen in the separation of these groups. Bound water content analysis showed that the extent of hydration of collagen is more in SD when compared to NS. Based on the results obtained, this study confirms the active involvement of dermal collagen in the formation of SD. It also emphasizes the need to study quantitatively the role of these various biochemical changes in the dermal collagen responsible for the variance between SR, SA, and NS.

Physical Therapy Challenges in Head and Neck Cancer

Treatment sequelae such as trismus, shoulder dysfunction syndrome resulting from spinal accessory nerve palsy, and radiotherapy-induced neck fibrosis are often overlooked when in the management of head and neck cancer patients. This chapter examines these underappreciated issues and their corresponding physical therapy intervention based on current evidence. Head and neck cancer survivors must contend with these disabilities for years after treatment has been concluded. A few quit their jobs which puts a tremendous burden on them and their families with a diminished quality of life. The physical rehabilitative needs of head and neck cancer patients and useful interventions to help meet them are addressed.

Extracorporeal Shock Wave Therapy: An Emerging Treatment Modality for Retracting Scars of the Hands

Prolonged and abnormal scarring after trauma, burns and surgical procedures often results in a pathologic scar. We evaluated the efficacy of unfocused shock wave treatment, alone or in combination with manual therapy, on retracting scars on the hands. Scar appearance was assessed by means of the modified Vancouver Scar Scale; functional hand mobility was evaluated using a range-of-motion scale, whereas a visual analogue score was implemented for detecting any improvements in referred pain. Additionally, biopsy specimens were collected for clinico-pathologic correlation. For each active treatment group, statistically significant improvements in modified Vancouver Scar Scale were recorded as early as five treatment sessions and confirmed 2 wk after the last treatment session. Analogous results were observed when assessing pain and range of movement. Histopathological examination revealed significant increases in dermal fibroblasts in each active treatment group, as well as in neoangiogenetic response and type-I collagen concentration.

Optimization of an ex vivo wound healing model in the adult human skin: Functional evaluation using photodynamic therapy

Limited utility of in vitro tests and animal models of human repair, create a demand for alternative models of cutaneous healing capable of functional testing. The adult human skin Wound Healing Organ Culture (WHOC) provides a useful model, to study repair and enable evaluation of therapies such as the photodynamic therapy (PDT). Thus, the aim here was to identify the optimal WHOC model and to evaluate the role of PDT in repair. Wound geometry, system of support, and growth media, cellular and matrix biomarkers were investigated in WHOC models. Subsequently, cellular activity, extracellular matrix remodeling, and oxidative stress plus gene and protein levels of makers of wound repair measured the effect of PDT on the optimized WHOC. WHOCs embedded in collagen and supplemented DMEM were better organized showing stratified epidermis and compact dermis with developing neo-epidermis. Post-PDT, the advancing reepithelialization tongue was 3.5 folds longer, and was highly proliferative with CK-14 plus p16 increased (p < 0.05) compared to controls. The neo-epidermis was fully differentiated forming neo-collagen. Proliferating nuclear antigen, p16, COLI, COLIII, MMP3, MMP19, and α-SMA were significantly more expressed (p < 0.05) in dermis surrounding the healing wound. In conclusion, an optimal model of WHOC treated with PDT shows increased reepithelialization and extracellular matrix reconstruction and remodeling, supporting evidence toward development of an optimal ex vivo wound healing model.

Expression of matrix metalloproteinase-1 in round ligament and uterosacral ligament tissue from women with pelvic organ prolapse

To evaluate the matrix metalloproteinase-1 (MMP-1) expression in different parts of pelvic connective tissue in postmenopausal women with and without pelvic organ prolapse (POP). Ninety-one samples were obtained from only postmenopausal women (42 with POP and 49 non-POP subjects). All women were evaluated by pelvic organ prolapse quantitation. The POP group had stage 2 or more, and the controls had stage 1 or less. Round ligament (RL) and uterosacral ligament (USL) biopsies were obtained from women with POP and controls. Immunohistochemistry for MMP-1 was performed on formalin-fixed and paraffin-embedded sections. The two groups were matched for age, body mass index, parity and postmenopausal status. MedCalc Statistical Software Programme Version 12.0.5 was used for statistical analysis. Expression of MMP-1 were significantly higher in both RL and USL tissue from postmenopausal women with POP, compared with controls. MMP-1 immunoreactivities were identified in both RL and USL biopsies from all women with and without POP. The expression pattern of MMP-1 were similar in these ligaments and were significantly higher in POP group compared with control subjects. These changes indicate a possible relation between MMP-1 expression of RL and USL in women with and without POP.

Skin perfusion and oxygenation changes in radiation fibrosis

BACKGROUND

Ionizing radiation is known to have deleterious chronic effects on skin, including fibrosis and poor wound healing, hypothesized as mediated by ischemia and hypoxia. Past studies have been unable to simultaneously investigate changes in perfusion and oxygenation as separate parameters. Hyperspectral imaging has emerged as a tool with which to concurrently measure skin perfusion and oxygenation. The authors investigated the use of hyperspectral imaging in a novel murine model of chronic radiation injury.

METHODS

Areas of flank skin (n = 20) on hairless mice were exposed to a 50-Gy dose of beta-radiation. Hyperspectral imaging acquisition was performed at select points through 8 weeks. Immunohistochemical staining and gene expression analysis were performed to evaluate cutaneous vascular density, epidermal cell hypoxia, and angiogenic factors.

RESULTS

All irradiated areas developed a chronic-phase wound by day 28. Hyperspectral imaging demonstrated a 21 percent decline in perfusion on day 56 (p < 0.001), whereas oxygenation levels were unchanged. A 1.7-fold reduction in blood vessel density was measured in irradiated skin compared with control tissue (p < 0.001), but no difference in epidermal cell hypoxia was observed. Vascular endothelial growth factor and related receptor expression were significantly lower in irradiated tissue.

CONCLUSIONS

The authors' analysis does not support the presence of hypoxia in chronic-phase irradiated skin but suggests that hypoperfusion may be a predominant characteristic. The concurrent states of hypoperfusion and normoxia may be explained by the lower metabolic demands of fibrosed tissue.

Effects of zoledronate on irradiated bone in vivo: analysis of the collagen types I, V and their cross-links lysylpyridinoline, hydroxylysylpyridinoline and hydroxyproline

Radiotherapy can lead to a reduction of bone density with an increased risk of pathological fractures. Bisphosphonates may represent a preventive treatment option by increasing the density of anorganic bone mineral. Yet it is unknown how bisphosphonates act on irradiated collagen cross-links, which play an essential role for the mechanical stability of bone. The aim of this study was to evaluate the effects of zoledronate on bone collagens and their cross-links after irradiation. The right femur of 37 rats was irradiated with a single dose of 9.5 Gy at a high dose rate using an afterloading machine. Half of the rats (n=18) received additionally a single dose zoledronate (0.1 mg/kg body weight). Fourteen and 100 days after irradiation the femora were collected for histologic evaluation and determination of the collagen cross-links lysylpyridinoline, hydroxylysylpyridinoline, and hydroxyproline. The collagen types were characterized by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Fourteen days after treatment the lysylpyridinoline levels of all treatment groups were significantly lower compared to the untreated control. After 100 days, in the combined radiotherapy+zoledronate group significantly lower lysylpyridinoline values were determined (p=0.009). Radiotherapy and/or zoledronate did not change significantly the level of hydroxylysylpyridinoline. The concentration of hydroxyproline was 14 days after irradiation significantly higher in the combined treatment group compared to the control. No significant differences were observed 100 days after treatment. Zoledronate does not have the ability to restore the physiological bone collagen cross-link levels after radiotherapy. However, this would be necessary for regaining the physiological mechanical stability of bone after irradiation and therefore to prevent effectively radiation-induced fractures.

IL-6 receptor inhibition positively modulates bone balance in rheumatoid arthritis patients with an inadequate response to anti-tumor necrosis factor therapy: biochemical marker analysis of bone metabolism in the tocilizumab RADIATE study (NCT00106522)

OBJECTIVE

To evaluate changes in biochemical markers of bone metabolism in response to tocilizumab in patients with anti-tumor necrosis factor-refractory rheumatoid arthritis (RA).

METHODS

RADIATE was a randomized, double-blind, placebo-controlled, parallel-group phase 3 trial. C-reactive protein, osteocalcin (OC), C-terminal telopeptides of type-I collagen (C-terminal telopeptides of type-1 collagen (CTX-I) and type-I collagen degradation product), and matrix metalloproteinase-3 (MMP-3) serum levels were analyzed from 299 RA patients. Patients were randomly assigned to either tocilizumab (4 or 8 mg/kg) or placebo intravenously every 4 weeks, along with concomitant stable methotrexate (10 to 25 mg weekly) in all treatment arms. The change in biochemical markers CTX-I and OC in combination was evaluated as a measure of net bone balance, a reflection of the change in equilibrium between resorption and formation.

RESULTS

Both tocilizumab doses decreased C-reactive protein levels and significantly inhibited cathepsin K-mediated bone resorption in RADIATE subjects, as measured by a decrease in CTX-I. There was a significant overall improvement in net bone balance at week 16 as measured by a decrease in the CTX-I:OC ratio (-25%, P < 0.01). Furthermore, a significant reduction in MMP-3 (43%, P < 0.001) and type-I collagen degradation product levels (18%, P < 0.001) were observed following treatment, both consistent with decreased MMP-mediated type-I collagen catabolism in joint tissue.

CONCLUSIONS

In anti-tumor necrosis factor-refractory patients, tocilizumab significantly reduced the levels of biochemical markers of cathepsin K-mediated bone resorption and MMP-mediated tissue degradation and remodeling. These observations suggest that tocilizumab has a positive effect on bone balance, which could in part explain the retardation of progressive structural damage observed with tocilizumab. Clinical trial registry number: NCT00106522.

MMP-12 catalytic domain recognizes and cleaves at multiple sites in human skin collagen type I and type III

Collagens of either soft connective or mineralized tissues are subject to continuous remodeling and turnover. Undesired cleavage can be the result of an imbalance between proteases and their inhibitors. Owing to their superhelical structure, collagens are resistant to many proteases and matrix metalloproteinases (MMPs) are required to initiate further degradation by other enzymes. Several MMPs are known to degrade collagens, but the action of MMP-12 has not yet been studied in detail. In this work, the potential of MMP-12 in recognizing sites in human skin collagen types I and III has been investigated. The catalytic domain of MMP-12 binds to the triple helix and cleaves the typical sites -Gly(775)-Leu(776)- in alpha-2 type I collagen and -Gly(775)-Ile(776)- in alpha-1 type I and type III collagens and at multiple other sites in both collagen types. Moreover, it was observed that the region around these typical sites contains comparatively less prolines, of which some have been proven to be only partially hydroxylated. This is of relevance since partial hydroxylation in the vicinity of a potential scissile bond may have a local effect on the conformational thermodynamics with probable consequences on the collagenolysis process. Taken together, the results of the present work confirm that the catalytic domain of MMP-12 alone binds and degrades collagens I and III.

The serial free fat transfer in irradiated prosthetic breast reconstructions

BACKGROUND

This study investigated the effects of lipofilling on both the functional and the aesthetic aspects of breast reconstruction.

METHODS

Sixty-one consecutive patients with irradiated reconstructed breasts (62 breasts) were offered free fat transfer to enhance the results and correct the defects. Twenty patients were enrolled (active branch) and underwent multiple sessions of lipofilling, while the others were considered controls. The fat was harvested by syringe and processed by saline washing only (no centrifugation). Three months after the last session the functional outcome was evaluated using the LENT-SOMA scoring system and the aesthetic outcome was evaluated using a visual 5-point scale.

RESULTS

A significant improvement in all the LENT-SOMA scores after free fat grafting was observed; the scores after treatment were all significantly lower than those before it and were also significantly lower than those of untreated breasts. These results also were confirmed by comparing homogeneous subgroups of breasts with similar LENT-SOMA ranks before treatment. Similarly, the cosmetic outcomes were significantly enhanced after serial lipofilling. The four cases in the active branch with severe flap thinning resolved with no implant exposure (mean follow-up = 17.6 months), while implant exposure occurred in the two cases with the same problem in the control group. In one case, a Baker 3-4 capsular contracture was downgraded to Baker 1 after only one session of lipofilling. No complications occurred in the treated cases.

CONCLUSION

Free fat transfer is a safe and reliable technique in improving the outcomes of irradiated reconstructed breasts with implants.

A novel organotypic model mimics the tumor microenvironment

Carcinoma cell invasion is traditionally studied in three-dimensional organotypic models composed of type I collagen and fibroblasts. However, carcinoma cell behavior is affected by the various cell types and the extracellular matrix (ECM) in the tumor microenvironment. In this study, a novel organotypic model based on human uterine leiomyoma tissue was established and characterized to create a more authentic environment for carcinoma cells. Human tongue squamous cell carcinoma cells (HSC-3) were cultured on top of either collagen or myoma. Organotypic sections were examined by immunohistochemistry and in situ hybridization. The maximal invasion depth of HSC-3 cells was markedly increased in myomas compared with collagen. In myomas, various cell types and ECM components were present, and the HSC-3 cells only expressed ECM molecules in the myoma model. Organotypic media were analyzed by radioimmunoassay, zymography, or Western blotting. During carcinoma cell invasion, matrix metalloprotease-9 production and collagen degradation were enhanced particularly in the myoma model. To evaluate the general applicability of the myoma model, several oral carcinoma, breast carcinoma, and melanoma cell lines were cultured on myomas and found to invade in highly distinct patterns. We conclude that myoma tissue mimics the native tumor microenvironment better than previous organotypic models and possibly enhances epithelial-to-mesenchymal transition. Thus, the myoma model provides a promising tool for analyzing the behavior of carcinoma cells.

Haplotype-based analysis of genes associated with risk of adverse skin reactions after radiotherapy in breast cancer patients

PURPOSE

To identify haplotypes of single nucleotide polymorphism markers associated with the risk of early adverse skin reactions (EASRs) after radiotherapy in breast cancer patients.

METHODS AND MATERIALS

DNA was sampled from 399 Japanese breast cancer patients who qualified for breast-conserving radiotherapy. Using the National Cancer Institute-Common Toxicity Criteria scoring system, version 2, the patients were grouped according to EASRs, defined as those occurring within 3 months of starting radiotherapy (Grade 1 or less, n = 290; Grade 2 or greater, n = 109). A total of 999 single nucleotide polymorphisms from 137 candidate genes for radiation susceptibility were genotyped, and the haplotype associations between groups were assessed.

RESULTS

The global haplotype association analysis (p < 0.05 and false discovery rate < 0.05) indicated that estimated haplotypes in six loci were associated with EASR risk. A comparison of the risk haplotype with the most frequent haplotype in each locus showed haplotype GGTT in CD44 (odds ratio [OR] = 2.17; 95% confidence interval [CI], 1.07-4.43) resulted in a significantly greater EASR risk. Five haplotypes, CG in MAD2L2 (OR = 0.55; 95% CI, 0.35-0.87), GTTG in PTTG1 (OR = 0.48; 95% CI, 0.24-0.96), TCC (OR = 0.48; 95% CI, 0.26-0.89) and CCG (OR = 0.50; 95% CI, 0.27-0.92) in RAD9A, and GCT in LIG3 (OR = 0.46; 95% CI, 0.22-0.93) were associated with a reduced EASR risk. No significant risk haplotype was observed in REV3L.

CONCLUSION

Individual radiosensitivity can be partly determined by these haplotypes in multiple loci. Our findings may lead to a better understanding of the mechanisms underlying the genetic variation in radiation sensitivity and resistance among breast cancer patients.

Radiation Induced Late Damage to the Barrier Function of Small Blood Vessels in Mouse Bladder

PURPOSE

We identified changes in vascular barrier function in relation to collagen deposition during the late radiation response of mouse bladders. In this study albumin leakage was assessed as a marker of blood vessel barrier disruption.

MATERIALS AND METHODS

Female C3H/Neu mice were irradiated with a single dose of 20 Gy and sacrificed for (immuno) histological studies after 90, 120, 180, 240 and 360 days. The fractional area of subepithelial tissue with extravascular albumin signal was defined. Moreover, the amount of collagen was determined after Masson's trichrome staining on an arbitrary score of 0 to 3.

RESULTS

Subepithelial albumin infiltration due to leakage from the blood vessels was seen in irradiated animals during the entire late phase. It was most pronounced at days 120 and 180 after treatment (vs control p <0.0001). Similarly an increase in collagen deposition in the bladder wall was seen during the whole late radiation phase but with increasing values toward the end of the experiment (day 360 vs control p <0.0001).

CONCLUSIONS

Irradiation of the bladder results in late damage to the barrier function of small subepithelial blood vessels, causing pronounced albumin leakage at the early steps of the chronic radiation reaction, clearly preceding excessive collagen deposition in the bladder wall. Current data suggest a vascular component in the development of late radiation induced changes in the bladder.

Radiotherapy for rectal carcinoma: an unusual cause of foreskin phimosis

Phimosis of the foreskin secondary to radiotherapy for a pelvic malignancy has not been previously described in the world literature. However, as radiotherapy is ever more widely used in the treatment of various pelvic malignancies, it is important to ensure that this complication is prevented by the use of appropriate penile shielding.

Analysis of non-genetic risk factors for adverse skin reactions to radiotherapy among 284 Breast Cancer patients

OBJECTIVES

We analyzed non-genetic risk factors for adverse skin reactions to irradiation at 4 collaborating Japanese institutions, to design future investigation into genetic risk factors for adverse skin reactions to irradiation in a multicenter setting.

METHODS

From April 2001, 284 breast cancer patients, who underwent radiotherapy with breast-conserving surgery, were enrolled from 4 collaborating institutions in Japan. We graded skin reactions according to international scoring systems. Clinical factors were tested against adverse effects.

RESULTS

Grade 1+ skin reactions were observed in 261 (92%) of the patients in less than 3 months, 118 (42%) at 3 months, and 29 (10%) at 6 months in the late phase. Univariate analysis of treatment risk factors (such as the use of a multi-leaf colimeter, wedge-filter, or immobilization device) for skin reactions revealed a significant association (p< 0.0001). After a variable selection procedure with logistic regression, the institution, operative procedure, and magnitude of photon energy remained significantly associated with acute skin reactions. Only the institution was an explanatory variable for skin reactions at 3 and 6 months in the final logistic model.

CONCLUSION

After stratification, substantial remaining variations in the occurrence of skin reactions of a given level suggested that individual genetic factors contribute markedly to individual radiosensitivity. Analysis of genetic factors associated with adverse effects would be possible by stratifying patients according to institution. Selection of eligible institutions, where appropriate treatment modalities could be performed, would also be possible when planning such a study.

Dentin-pulp complex responses to carious lesions

To understand the molecular events underlying the dentin-pulp complex responses to carious progression, we systematically analyzed tissue morphology and dentin matrix protein distribution in non-carious teeth and in teeth with enamel and dentin caries. Dentin matrix proteins analyzed included collagen type I, phosphophoryn (PP) and dentin sialoprotein (DSP), all of which play decisive roles in the dentin mineralization process. Human non-carious and carious third molar teeth were freshly collected, demineralized, and processed for hematoxylin and eosin staining. The ABC-peroxidase method was used for immunohistochemical staining of collagen type I, PP and DSP proteins using specific antibodies. In situ hybridization was also performed. In contrast to elongated odontoblasts in non-carious teeth, odontoblasts subjacent to dentin caries were cuboidal and fewer in number. The predentin zone was also dramatically reduced in teeth with dentin caries. The staining intensity for collagen type I, PP and DSP in the dentin-pulp complex increased progressively from non-carious teeth, to teeth with enamel and dentin caries. In situ hybridization studies showed DSP-PP mRNA expression in odontoblasts and dental pulp that was consistent with our immunohistochemical results. These results suggest that carious lesions stimulate the dentin-pulp complex to actively synthesize collagen type I, PP and DSP proteins. This response to carious lesions is likely to provide a basis for reparative and/or reactionary dentin formation.

Interleukin 1beta (IL1B) signaling is a critical component of radiation-induced skin fibrosis

Interleukin 1 beta (IL1B), a potent pro-inflammatory cytokine, is directly up-regulated by radiation and is known to regulate other inflammation-related molecules, such as the matrix metalloproteinases (MMPs) and their endogenous inhibitors (TIMPs). However, the nature of the interaction of IL1B with MMPs and TIMPs in radiation-induced skin fibrosis is unknown. We examined the response of primary dermal keratinocytes, fibroblasts and endothelial cells to single-fraction radiation (10 Gy) and compared the results to a temporal sequence of histology from irradiated C57BL/6 and IL1R1 knockout mice. These studies showed that keratinocytes are the major IL1-producing cells in vitro and that radiation induces an immediate and chronic elevation in the expression of IL1B mRNA in the skin of C57BL/6 mice. This elevation was principally early and was less pronounced in the IL1R1 knockout strain, which also demonstrated reduced late radiation fibrosis. Radiation also increased expression of MMP mRNA in C57BL/6 mice. Finally, exogenous IL1B protein induced robust endogenous IL1B mRNA expression, along with a brisk increase in MMPs and collagen III, but only in the C57BL/6 mice. In conclusion, these data suggest that IL1B plays a critical role in radiation-induced fibrosis and that the increased MMPs fail to block the IL1-related collagen accumulation.

Plasminogen activator inhibitor-I–related regulation of procollagen I (α1 and α2) by antitransforming growth factor-β1 treatment during radiation-impaired wound healing

PURPOSE

Plasminogen activator inhibitor (PAI)-1 mediates transforming growth factor-beta1 (TGF-beta1)-related signaling by stimulating collagen Type I synthesis in radiation-impaired wound healing. The regulation of alpha(I)-procollagen is contradictory in fibroblasts of different fibrotic lesions. It is not known whether anti-TGF-beta1 treatment specifically inhibits alpha(I)-procollagen synthesis. We used an experimental wound healing study to address anti-TGF-beta1-associated influence on alpha(I)-procollagen synthesis.

METHODS AND MATERIALS

A free flap was transplanted into the preirradiated (40 Gy) or nonirradiated neck region of Wistar rats: Group 1 (n = 8) surgery alone; Group 2 (n = 14) irradiation and surgery; Group 3 (n = 8) irradiation and surgery and anti-TGF-beta1 treatment. On the 14th postoperative day, skin samples were processed for fibroblast culture, in situ hybridization for TGF-beta1, immunohistochemistry, and immunoblotting for PAI-1, alpha1/alpha2(I)-procollagen.

RESULTS

Anti-TGF-beta1 significantly reduced TGF-beta1 mRNA (p < 0.05) and PAI-1 expression (p < 0.05). Anti-TGF-beta1 treatment in vivo significantly reduced alpha1(I)-procollagen protein (p < 0.05) and the number of expressing cells (p < 0.05) in contrast to significantly increased (p < 0.05) alpha2(I)-procollagen expression.

CONCLUSION

These results emphasize anti-TGF-beta1 treatment to reduce radiation-induced fibrosis by decreasing alpha1(I)-procollagen synthesis in vivo. alpha1(I)-procollagen and alpha2(I)-procollagen might be differentially regulated by anti-TGF-beta1 treatment. Increased TGF-beta signaling in irradiated skin fibroblasts seemed to be reversible, as shown by a reduction in PAI-1 expression after anti-TGF-beta1 treatment.

Effects of intense pulsed light and the 1,064 nm Nd:YAG laser on sun-damaged human skin: histologic and immunohistochemical analysis

BACKGROUND

Nonablative methods may produce collagen synthesis in sun-damaged skin.

OBJECTIVE

To study the effects of intense pulsed light (IPL) and 1,064 nm neodymium:yttrium-aluminum-garnet (Nd:YAG) laser: a histologic and immunohistochemical analysis of sun-damaged skin.

MATERIALS AND METHODS

Nine subjects participated. Five subjects received five-monthly treatments with IPL (560 nm cutoff filter, 8 x 35 mm spot size, pulse duration 2.4/4.2 milliseconds, pulse delay 15 milliseconds, fluence 28-35 J/cm2). Four subjects received treatment with a 1,064 nm Nd:YAG laser (130 J/cm2, triple pulse, 7.0/7.0/7.0-millisecond pulse duration, 75-millisecond delay). Routine histology and immunohistochemistry on 2 mm punch biopsies were taken before treatment and then at 3 and 6 months. We quantified collagen in the upper dermis and expression of heat shock protein 70 and procollagen 1.

RESULTS

Pretreatment specimens contained solar damage. After treatment with the 1,064 nm Nd:YAG laser, the amount of collagen in the papillary dermis was slightly thicker than in those subjects treated with the IPL device (nonsignificant differences). Scattered dendritic cells in the papillary and upper reticular dermis expressed heat shock protein 70 and procollagen 1 after treatment with either light device.

CONCLUSION

Both the IPL and 1,064 nm Nd:YAG laser-induced heat activation of superficial dermal dendritic cells resulted in deposition of collagen in the papillary dermis without evident morphologic damage to the epidermis or dermis.

The production of collagen and the activity of mast-cell chymase increase in human skin after irradiation therapy

Fibrosis is a common complication of radiotherapy. The pathogenesis of radiation-induced fibrosis is not known in detail. There is increasing evidence to suggest that mast cells contribute to various fibrotic conditions. Several mast-cell mediators have been proposed to have a role in fibrogenesis. Tryptase and chymase, the predominant proteins in mast cells, have been shown to induce fibroblast proliferation and collagen synthesis in vitro. In order to explore the role of mast cells in irradiation-induced fibrosis, we analyzed skin biopsies and suction blister fluid (SBF) samples from the lesional and healthy-looking skin of 10 patients who had been treated for breast cancer with surgery and radiotherapy. The biopsies were analyzed histochemically for mast-cell tryptase, chymase, kit receptor, and tumor necrosis factor-alpha. Skin collagen synthesis was assessed by determining the levels of type I and III procollagen amino-terminal propeptides (PINP and PIIINP) in SBF and using immunohistochemical staining for PINP. Immunohistochemical stainings for prolyl-4-hydroxylase reflecting collagen synthesis and chymase immunoreactivity in irradiated and control skin were also performed. The mean level of procollagen propeptides in SBF, which reflects actual skin collagen synthesis in vivo, was markedly increased in irradiated skin compared to corresponding healthy control skin areas. The mean number of PINP-positive fibroblasts was also significantly increased in the upper dermis of radiotherapy-treated skin. The number of cells positive for tryptase, chymase and kit receptor was markedly increased in irradiated skin. In addition, using double-staining techniques, it was possible to demonstrate that in some areas of the dermis, tryptase-positive mast cells and fibroblasts are closely associated. These findings suggest a possible role of mast cells in enhanced skin collagen synthesis and fibrosis induced by radiotherapy.

Procollagen 1 expression in atypical fibroxanthoma and other tumors

BACKGROUND

Procollagen (PC) is secreted by fibroblasts into the extracellular matrix, where it is cleaved to form collagen. The rat anti-human PC-1 monoclonal antibody has been reported to react with atypical fibroxanthoma (AFX), a poorly differentiated but usually benign skin lesion common in elderly patients. We have studied PC-1 staining in 50 tumors with AFX histological features (four of which were subsequently reclassified as non-AFX tumors) to confirm this prior observation. In addition, we have investigated PC-1 in other skin tumors, particularly those with spindled cell or sclerosing/desmoplastic morphologies.

METHOD

Archival material was retrieved and sections were prepared and immunostained with PC-1 as well as a panel of antibodies, including S-100 and MNF-116 (cytokeratins 5, 6, 7, 8, 17, and 19).

RESULTS

PC-1 staining was strongly positive in 40 of 46 (87%) AFXs. Three AFXs displayed weak staining with PC-1 even after repeat staining of 10 tumors that were initially weak. Three additional tumors stained with both PC-1 and MNF-116 and were classified as AFX-like squamous cell carcinoma (SCC). One tumor with AFX-like histology was PC-1 negative and S-100 positive and was classified as an AFX-like melanoma. Positive staining in tumor cells was observed in three of nine (33%) desmoplastic malignant melanomas, three of eight (38%) desmoplastic SCCs, zero of 10 (0%) desmoplastic trichoepitheliomas, zero of 10 (0%) morpheic basal cell carcinomas, and zero of 10 (0%) sclerosing sweat duct carcinomas.

CONCLUSION

PC-1 is a useful antibody in a diagnostic immunohistochemical panel when investigating AFX and AFX-like tumors; however, good technical quality and careful interpretation are necessary when using a panel of antibodies, particularly to keratin and S-100 protein, for optimal accuracy.