Effect of gamma-interferon on the clinical and biologic evolution of hypertrophic scars and Dupuytren's disease: an open pilot study

Crosstalk between fibroblasts and immunocytes in fibrosis: From molecular mechanisms to clinical trials

BACKGROUND

The impact of fibroblasts on the immune system provides insight into the function of fibroblasts. In various tissue microenvironments, multiple fibroblast subtypes interact with immunocytes by secreting growth factors, cytokines, and chemokines, leading to wound healing, fibrosis, and escape of cancer immune surveillance. However, the specific mechanisms involved in the fibroblast-immunocyte interaction network have not yet been fully elucidated.

MAIN BODY AND CONCLUSION

Therefore, we systematically reviewed the molecular mechanisms of fibroblast-immunocyte interactions in fibrosis, from the history of cellular evolution and cell subtype divisions to the regulatory networks between fibroblasts and immunocytes. We also discuss how these communications function in different tissue and organ statuses, as well as potential therapies targeting the reciprocal fibroblast-immunocyte interplay in fibrosis. A comprehensive understanding of these functional cells under pathophysiological conditions and the mechanisms by which they communicate may lead to the development of effective and specific therapies targeting fibrosis.

Pharmacotherapies in Dupuytren Disease: Current and Novel Strategies

Dupuytren disease is a benign, progressive fibroproliferative disorder of the hands. To date, only one pharmacotherapy (clostridial collagenase) has been approved for use in Dupuytren disease. There is a great need for additional nonsurgical methods that can be used to either avoid the risks of invasive treatments or help minimize recurrence rates following treatment. A number of nonsurgical modalities have been discussed in the past and continue to appear in discussions among hand surgeons, despite highly variable and often poor or no long-term clinical data. This article reviews many of the pharmacotherapies discussed in the treatment of Dupuytren disease and novel therapies used in inflammation and fibrosis that offer potential treatment options.

Biological Targets for Dupuytren Disease

ABSTRACT

Dupuytren disease is a connective tissue disorder occurring on the palm, causing flexion contractures of fingers. There is a pressing need for therapeutic interventions that can slow, stop, or even incrementally reverse the progression of the disease. Numerous in vitro studies have shed light on cellular and molecular agents that contribute to contractures. This article comprehensively reviews various growth factors that can be targeted to prevent and limit the progression and recurrence of Dupuytren contracture (DC). Fibroblasts are the major cell population that has been reported for the contractures in DC, and they are also known to exacerbate the cytokine production. Limiting the fibroblast function by targeting the growth factor production will be of great benefit in treating DC. This review will focus on the studies that have shown to limit the exaggerated function of fibroblasts by reducing the expression of profibrotic growth factors by using antagonizing agents.

Interferon-γ enhances the antifibrotic effects of pirfenidone by attenuating IPF lung fibroblast activation and differentiation

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) pathogenesis involves multiple pathways, and combined antifibrotic therapy is needed for future IPF therapy. Inhaled interferon-γ (IFN-γ) was recently shown to be safe and without systemic effects in patients with IPF.

AIM

To examine the in vitro effects of individual and combined treatment with IFN-γ and pirfenidone (PFD) on normal and IPF fibroblast activation and extracellular matrix remodeling after TGF-β1 and PDGF-BB stimulation.

METHODS

IPF and normal human lung fibroblasts (NHLF) were treated with IFN-γ, PFD or a combination of both drugs in the presence of either TGF-β1 or PDGF-BB. The effects of TGF-β1 and PDGF-BB treatment on cell viability, proliferation, differentiation and migration were examined. The expression of collagen 1, matrix metalloproteinases (MMPs) and tissue inhibitors of MMP (TIMPs) was analyzed using qPCR, Western blotting and gelatin zymography. Total collagen content in conditioned media was also measured using a Sircol assay.

RESULTS

Compared to that of PFD, the effect of IFN-γ in downregulating normal and IPF lung fibroblast differentiation to myofibroblasts in response to TGF-β1 was more potent. Importantly, the combination of IFN-γ and PFD had a possibly synergistic/additive effect in inhibiting the TGF-β1- and PDGF-BB-induced proliferation, migration and differentiation of normal and IPF lung fibroblasts. Furthermore, both drugs reversed TGF-β1-induced effects on MMP-1, - 2, - 3, - 7, and - 9, while only PFD promoted TIMP-1 and-2 expression and release.

CONCLUSIONS

Our findings demonstrate that the antifibrotic effects of IFN-γ and PFD on normal and IPF lung fibroblasts are different and complementary. Combination therapy with inhaled IFN-γ and PFD in IPF is promising and should be further explored in IPF clinical trials.

Normal and keloid fibroblasts are differentially influenced by IFN-γ and triamcinolone as well as by their combination

Impaired wound healing as well as imbalanced cell proliferation and extracellular matrix synthesis and degeneration can cause aberrant scarring. The most severe impacts of such scarring on patients' lives are stigmatization and physical restriction. Although, a broad variety of combinatorial approaches with, e.g., glucocorticoids, chemotherapeutics, and immunomodulators are used, there is still a high recurrence rate of keloids. The aim of this study was to investigate which influence interferon γ (IFN-γ, 1.000-10.000 IU/mL) and/or triamcinolone acetonide (TA, 1 μg/mL) have on proliferation, cell viability, collagen type I synthesis, and cytokine secretion in healthy and keloid fibroblasts. It was shown that mono-treatment with IFN-γ or TA for 2 days induced a severe reduction of the proliferative potential in both cell species. The combinatory treatment (IFN-γ plus TA) of keloid fibroblasts enhanced the anti-proliferative effect of the mono-treatments, whereas no additional anti-proliferative effect was observed in normal fibroblasts. Furthermore, we observed that the combinatory treatment regimen reduced the expression of α-smooth muscle actin (α-SMA), an actin isotype contributing to cell-generated mechanical tension, in keloid fibroblasts. In normal fibroblasts, α-SMA was reduced by the mono-treatment with IFN-γ as well as by the combinatory treatment. The analysis of collagen-type I synthesis revealed that TA did not reduce collagen type I synthesis in normal fibroblasts but in keloid fibroblasts. IFN-γ reduced in both cell species the collagen type I synthesis. The combination of TA and IFN-γ intensified the previously observed collagen type I synthesis reduction in keloid fibroblasts. The herein presented data suggest the combinatory application of IFN-γ and TA as a promising therapy concept for keloids.

Range of motion, postoperative rehabilitation and patient satisfaction in MCP and PIP joints affected by Dupuytren Tubiana stage 1-3: collagenase enzymatic fasciotomy or limited fasciectomy? A clinical study in 52 patients

INTRODUCTION

In Switzerland, collagenase Clostridium histolyticum therapy (CCH) for Dupuytren's disease was introduced in 2011. This study analyzes possible differences between CCH and limited fasciectomy (LF) in terms of range of motion, patient satisfaction and postoperative rehabilitation.

MATERIALS AND METHODS

This retrospective study included 52 patients with Dupuytren's disease stage 1-3 according to Tubiana, treated with CCH or LF between January 2012 and December 2013. Complications were analyzed for each patient. The contracture of each treated joint measured on average at the 3 months and up to 2 years follow-up was compared with the preoperative values. The Michigan Hand score was evaluated at 2 years and the patients were asked to subjectively evaluate the outcome of the treatment and whether they would repeat it if necessary. Postoperative rehabilitation was also precisely quantified.

RESULTS

11 minor complications were reported for a complication rate of 29% in the CCH group. No major complications were reported in both groups. In the CCH group, mean MCP joint contracture was, respectively, 44° ± 20°, 9° ± 2° (gain of mobility compared to the preoperative situation 35°, P < 0.001), and 10° ± 3° (gain 34°, P < 0.001), respectively, before, at the 3 months' control and at the 2-year clinical control. In the LF group, mean MCP joint contracture was, respectively, 30° ± 21°, 2° ± 0.5° (gain 28°, P < 0.001), and 1° ± 0.5° (gain 29°, P < 0.001) for the same control periods. In the CCH group, mean PIP joint contracture was, respectively, 51° ± 21°, 18° ± 3° (gain of mobility compared to the preoperative situation 33°, P < 0.001), and 32° ± 4° (gain 19°, P < 0.001), respectively, before, at the 3 months' control and at the 2-year clinical control. In the LF group, mean PIP joint contracture was, respectively, 30° ± 20°, 2° ± 0.5° (gain of mobility compared to the preoperative situation 28°, P < 0.001), and 11° ± 4° (gain 19°, P < 0.001) for the same control periods. Outcomes were compared across the LF and CCH groups: surgery performed better than collagenase for PIP joint treatment at early (P < 0.001) and 2-year follow-up (P = 0.004) controls. However, patient satisfaction was higher in the CCH group: 92% were satisfied or very satisfied of the treatment compared to 71% in the LF group. All patients would reiterate the treatment in the CCH group if necessary compared to only 71% in the LF group. Rehabilitation was highly reduced in the CCH group compared to the LF group.

CONCLUSION

In this study, surgery performed better than collagenase at early and 2-year follow-up in PIP joints and similar in MCP joints. While surgery seems to achieve better results, collagenase is considered in Switzerland as an off-the-shelf therapy that provides consistent results without scars, with shorter rehabilitation time, minor hand therapy, shorter splinting time, and applicability.

LEVEL OF EVIDENCE AND STUDY TYPE

Level III.

Alternative and Adjunctive Treatments for Dupuytren Disease

Clinicians struggle with limited efficacy and durability of standard treatments when treating patients with Dupuytren disease diathesis. Alternative treatments such as low-dose radiation therapy in early phase of disease, supplemental pharmacotherapy with anti-inflammatory and/or anti-mitotic drugs, as well as other pharmacologic targets, and more aggressive surgery such as dermofasciectomy all have been reported with variable success or with serious side effects that hamper their standard use. This article gives an overview of the available literature.

Corticosteroid inhibits differentiation of palmar fibromatosis-derived stem cells (FSCs) through downregulation of transforming growth factor-β1 (TGF-β1)

Treatment for musculoskeletal fibromatosis remains challenging. Surgical excision for fibromatosis is the standard therapy but recurrence remains high. Corticosteroids, an anti-fibrogenic compound, have been used to treat early stage palmar fibromatosis, but the mechanism is unknown. We investigated the inhibitory mechanism effect of corticosteroids in the murine model of fibromatosis nodule as well as in cultured FSCs. Quantitative reverse transcription/polymerase chain reaction (PCR) analysis and immunofluorescence (IF) staining for markers of myofibroblasts (α-smooth muscle actin and type III collagen) were used to examine the effect of dexamethasone on myofibroblasic differentiation of FSCs both in vitro and in vivo. Transforming growth factor-β1 (TGF-β1) signaling and its downstream targets were examined using western blot analysis. TGF-β1 expression in FSCs before and after dexamethasone treatment was compared. In addition, inhibition of TGF-β1 expression was examined using RNA interference (RNAi) on FSCs, both in vitro and in vivo. Treating FSCs with dexamethasone inhibited FSCs’ myofibroblastic differentiation in vitro. Treating FSCs with dexamethasone before or after implantation further inhibited formation of fibromatosis nodules. Dexamethasone suppressed expression of TGF-β1 and pSmad2/3 by FSCs in vitro. TGF-β1 knockdown FSCs showed reducing myofibroblastic differentiation both in vitro and in vivo. Finally, addition of TGF-β1 abolished dexamethasone-mediated inhibition of myofibroblastic differentiation. Dexamethasone inhibits the myofibroblastic differentiated potential of FSCs both in vitro and in vivo through inhibition of TGF-β1 expression in FSCs. TGF-β1 plays a key role in myofibroblastic differentiation.

Cytokine Interferon-γ suppresses the function of capsule myofibroblasts and induces cell apoptosis

Myofibroblasts (MFs), a contractile subset of fibroblasts, play a pivotal role in physiological wound healing and in the development of many fibroconnective disorders. The complex cytokine network regulating the function of MFs in joint stiffness is still poorly understood. In this in vitro study, we investigated the effect of the cytokine Interferon-gamma (IFN-γ) on MFs isolated from human joint capsules. MFs were cultivated either in the presence of increasing concentrations of IFN-γ alone or in combination with IFN-γ neutralizing antibodies. Cell viability, cytotoxicity, apoptosis, and mRNA gene expression of the MF markers alpha-smooth muscle actin (α-SMA) and collagen type I were analyzed in MF cultures. Contraction potential was analyzed in an established collagen gel contraction assay simulating the extracellular matrix. Using immunofluorescence staining, we could verify that MFs express IFN-γ-receptor (R)-1 on their membrane. IFN-γ decreased MF viability and significantly elevated the apoptosis rate in a dose-dependent manner. IFN-γ down-regulated α-SMA and collagen type I mRNA expression which was associated with a diminished MF mediated contraction of the gel matrices. These effects were suppressed by simultaneous treatment of cells with a neutralizing IFN-γ antibody. Our experiments confirm the hypothesis that the cytokine IFN-γ is a crucial component of the regulatory network of capsule MFs. IFN-γ notably influences the ability of MFs to contract collagen matrices by suppressing α-SMA gene expression. IFN-γ is toxic for MFs in high concentrations and may negatively regulate the number of pro-fibrotic MFs during the healing process via induction of cell apoptosis. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2524-2533, 2017.

Long-term follow-up of Dupuytren disease after injection of triamcinolone acetonide in Chinese patients in Taiwan

Injection of triamcinolone acetonide is a non-operative treatment for early-stage Dupuytren disease in Caucasians, but its effectiveness in non-Caucasians is unclear. We report averaged 5-year follow-up results of 37 patients (49 affected hands) with early-stage Dupuytren disease for patients in Taiwan (non-Caucasian) who received a single dose of 5 mg triamcinolone acetonide injection into nodules monthly for 3 months. Using ultrasound, we recorded no progression of sizes of the modules following injection after 6 months. After an average 5-year follow-up, two patients with three hands (6%) experienced reactivation of the treated nodules. None required surgical intervention. Ultrasound examination showed that sizes of the treated Dupuytren nodules decreased significantly by 40% 6 months after injection and 56% at the final follow-up. We conclude that in these Chinese patients in Taiwan with early Dupuytren nodules, triamcinolone acetonide injection was effective in reducing the size of the Dupuytren nodules and maintaining long-term durable control of the nodular growth.

LEVEL OF EVIDENCE

III.

Myofibroblasts in Palatal Wound Healing: Prospects for the Reduction of Wound Contraction after Cleft Palate Repair

The surgical closure of orofacial clefts is considered to impair maxillary growth and dento-alveolar development. Wound contraction and subsequent scar tissue formation, during healing of these surgical wounds, contribute largely to these growth disturbances. The potential to minimize wound contraction and subsequent scarring by clinical interventions depends on the surgeon’s knowledge of the events responsible for these phenomena. Fibroblasts initiate wound contraction, but proto-myofibroblasts and mature myofibroblasts are by far the most important cells in this process. Myofibroblasts are characterized by their cytoskeleton, which contains alpha-smooth-muscle actin. Additionally, their contractile apparatus contains bundles of actin microfilaments and associated contractile proteins, such as non-muscle myosin. This contractile apparatus is thought to be the major force-generating element involved in wound contraction. After closure of the wound, the myofibroblasts disappear by apoptosis, and a less cellular scar is formed. A reduction of contraction and scarring might be obtained by inhibition of myofibroblast differentiation, stimulation of their de-differentiation, stimulation of myofibroblast apoptosis, or impairment of myofibroblast function. In this review, we will discuss all of these possibilities, which ultimately may lead to a better outcome of cleft palate surgery.

The Impact of Collagenase Clostridium histolyticum Introduction on Dupuytren Treatment Patterns in the United States

PURPOSE

The U.S. Food and Drug Administration approved the use of collagenase Clostridium histolyticum (CCH) in the United States in February 2010. This study addresses the impact of that approval on the number of Dupuytren contracture (DC) encounters and treatment patterns in the United States.

METHODS

Using the Intercontinental Marketing Services Health Office-Based Medical Claims database, we identified the monthly number of DC encounters and DC procedures between January 2007 and December 2013. Collagenase Clostridium histolyticum usage data from March 2010 to December 2013 was derived from the U.S. CCH manufacturer's data warehouse. Using the combined data, the yearly increasing trends in DC encounters and treatment volume were compared before and after the introduction of CCH. Time trends in the relative procedure frequencies were then examined. Finally, the presence of seasonal variation was tested for in each treatment type.

RESULTS

Dupuytren contracture encounters increased on average by 19,015 per year between 2007 and 2009, whereas between 2011 and 2013, DC encounters increased on average by 34,940 per year. In terms of absolute procedure counts, the surgery trend line began decreasing in 2010 with the release of CCH. Meanwhile, CCH continuously increased between 2010 and 2013, and needle aponeurotomy (NA) remained relatively stable. By the year 2013, minimally invasive techniques (NA and CCH) comprised 39% of all treatment, compared with only 14% in 2007. Lastly, there was a statistically significant seasonal increase in the number of surgical procedures during the wintertime but no seasonal variation in NA or CCH.

CONCLUSIONS

After the introduction of CCH, the number of Dupuytren encounters increased at a greater annual rate. The introduction and growth of CCH coincided with a decrease in surgery. The number of NA procedures remained steady throughout the study period. The number of open surgery cases followed a predictable seasonal variation with more procedures during the winter months, but this seasonal variation was not seen with less invasive techniques.

TYPE OF STUDY/LEVEL OF EVIDENCE

Economic/Decision Analysis II.

Angiotensin receptors in Dupuytren's tissue: Implications for the pharnnacological treatment of Dupuytren's disease

The role of Angiotensin II as a pro-fibrotic mediator has been established in models of cardiac, hepatic and renal fibrosis. The administration of Angiotensin-Converting Enzyme (ACE) – inhibitors to these models results in a reduction in the myofibroblast population and collagen synthesis. In rodent excisionat wound-healing experiments, an ACE inhibitor reduced the rate of wound contraction, collagen deposition and angiogenesis. Using immunohistochemistry, the presence of Angiotensin I receptors was identified within tissue samples from patients with Dupuytren's disease. These were found to be co-localised with areas of myofibrobtast expression. This co-localisation has implications for the potential of pharmacological regulation of Dupuytren's disease. Further research is necessary to confirm whether the use of ACE-inhibitors can modulate this disease process, which until now has not been responsive to safe, effective pharmacological treatment.

The myofibroblast, a key cell in normal and pathological tissue repair

Myofibroblasts are characterized by their expression of α-smooth muscle actin, their enhanced contractility when compared to normal fibroblasts and their increased synthetic activity of extracellular matrix proteins. Myofibroblasts play an important role in normal tissue repair processes, particularly in the skin where they were first described. During normal tissue repair, they appear transiently and are then lost via apoptosis. However, the chronic presence and continued activity of myofibroblasts characterize many fibrotic pathologies, in the skin and internal organs including the liver, kidney and lung. More recently, it has become clear that myofibroblasts also play a role in many types of cancer as stromal or cancer-associated myofibroblast. The fact that myofibroblasts are now known to be key players in many pathologies makes understanding their functions, origin and the regulation of their differentiation important to enable them to be regulated in normal physiology and targeted in fibrosis, scarring and cancer.

Dupuytren's Contracture: A Bibliometric Study of the Most Cited Papers

The literature on Dupuytren's contracture is vast yet little information is known as to which papers have been the most influential. The purpose of this study was to identify the 50 most cited papers on Dupuytren's contracture and perform a citation analysis. Utilizing the Web of Science, 23 surgical, medical, plastic and hand surgery journals were searched for papers on Dupuytren's contracture. Resulting articles were ranked in order of times cited and each paper was analyzed for article-type, year of publication, country of origin, institution and level of evidence. The 50 most cited articles represent many important landmarks in Dupuytren's treatment and contain several seminal works by experts in the field. Whilst the top 50 list highlights the important papers on the condition, they certainly do not provide information about the quality of the evidence of the research, as most papers presented level 4 or 5 evidence.

Intralesional injection treatment of hypertrophic scars and keloids: a systematic review regarding outcomes

Background

The aim of this review was to explore the existing body of literature focusing on the intralesional treatments of keloids and hypertrophic scars.

Methods

A comprehensive systematic review of related articles was conducted across multiple databases. Article selection was limited to those published in the English language between 1950 and 2014. Search terms for the on-line research were “scar(s),” “keloid(s),” “hypertrophic,” “injection,” “intralesional,” and “treatment”.

Results

The initial search returned 2548 published articles. After full text review, the final search yielded 11 articles that met inclusion criteria. A total of 14 patient samples in 11 articles were collected. The most frequent intralesional injection treatment studied was triamcinolone (n = 5), followed by bleomycin (n = 3), 5-fluorouracil (n = 2), verapamil (n = 2), cryosurgery, and collagenase. The scar height reduction for all but one study was demonstrated, with acceptable complication and recurrence rate. Only three articles reported a follow-up period longer than 18 months, and only two studies used standardized outcome criteria with a quantitative scale.

Conclusions

Although many treatment options have already been described in the literature, there is no universally accepted treatment resulting in permanent hypertrophic or keloid scar ablation. The lack of adequately long-term powered randomized controlled trials does not permit to establish definitive conclusions with implications for routine clinical practice.

Level of evidence

III/Therapeutic

Dupuytren's disease therapy: targeting the vicious cycle of myofibroblasts?

INTRODUCTION

Dupuytren's disease (DD) is a proliferative fibromatosis of the hand, which causes permanent flexion contracture of the digits and, ultimately, loss of function. The treatment of DD is complex and involves surgical and nonsurgical approaches, with the goal of removing the affected tissue. New biological targets are under investigation in order to develop innovative therapies.

AREAS COVERED

The etiology of DD is still unknown. Several authors who focused their studies on the genetics of DD recognized an inherited autosomal dominant pattern. Actually, DD is a multifactorial and complex disease. Myofibroblasts are thought to play a crucial role in its pathogenesis, although their origin is not clear.

EXPERT OPINION

There is a general consensus that a better understanding of cellular and molecular mechanisms of DD will lead to the design of more specific and effective treatment alternatives. In this review, the authors hypothesize a new biological model for DD pathology, where myofibroblasts enhance the reservoir of the disease acting as if in a vicious cycle. This could help, ultimately, in identifying new therapeutic strategies to treat this common and disabling fibroproliferative disorder.

Fibroblasts from phenotypically normal palmar fascia exhibit molecular profiles highly similar to fibroblasts from active disease in Dupuytren's Contracture

BACKGROUND

Dupuytren's contracture (DC) is a fibroproliferative disorder characterized by the progressive development of a scar-like collagen-rich cord that affects the palmar fascia of the hand and leads to digital flexion contractures. DC is most commonly treated by surgical resection of the diseased tissue, but has a high reported recurrence rate ranging from 27% to 80%. We sought to determine if the transcriptomic profiles of fibroblasts derived from DC-affected palmar fascia, adjacent phenotypically normal palmar fascia, and non-DC palmar fascial tissues might provide mechanistic clues to understanding the puzzle of disease predisposition and recurrence in DC.

METHODS

To achieve this, total RNA was obtained from fibroblasts derived from primary DC-affected palmar fascia, patient-matched unaffected palmar fascia, and palmar fascia from non-DC patients undergoing carpal tunnel release (6 patients in each group). These cells were grown on a type-1 collagen substrate (to better mimic their in vivo environments). Microarray analyses were subsequently performed using Illumina BeadChip arrays to compare the transcriptomic profiles of these three cell populations. Data were analyzed using Significance Analysis of Microarrays (SAM v3.02), hierarchical clustering, concordance mapping and Venn diagram.

RESULTS

We found that the transcriptomic profiles of DC-disease fibroblasts and fibroblasts from unaffected fascia of DC patients exhibited a much greater overlap than fibroblasts derived from the palmar fascia of patients undergoing carpal tunnel release. Quantitative real time RT-PCR confirmed the differential expression of select genes validating the microarray data analyses. These data are consistent with the hypothesis that predisposition and recurrence in DC may stem, at least in part, from intrinsic similarities in the basal gene expression of diseased and phenotypically unaffected palmar fascia fibroblasts. These data also demonstrate that a collagen-rich environment differentially alters gene expression in these cells. In addition, Ingenuity pathway analysis of the specific biological pathways that differentiate DC-derived cells from carpal tunnel-derived cells has identified the potential involvement of microRNAs in this fibroproliferative disorder.

CONCLUSIONS

These data show that the transcriptomic profiles of DC-disease fibroblasts and fibroblasts from unaffected palmar fascia in DC patients are highly similar, and differ significantly from the transcriptomic profiles of fibroblasts from the palmar fascia of patients undergoing carpal tunnel release.

Recent developments in myofibroblast biology: paradigms for connective tissue remodeling

The discovery of the myofibroblast has opened new perspectives for the comprehension of the biological mechanisms involved in wound healing and fibrotic diseases. In recent years, many advances have been made in understanding important aspects of myofibroblast basic biological characteristics. This review summarizes such advances in several fields, such as the following: i) force production by the myofibroblast and mechanisms of connective tissue remodeling; ii) factors controlling the expression of α-smooth muscle actin, the most used marker of myofibroblastic phenotype and, more important, involved in force generation by the myofibroblast; and iii) factors affecting genesis of the myofibroblast and its differentiation from precursor cells, in particular epigenetic factors, such as DNA methylation, microRNAs, and histone modification. We also review the origin and the specific features of the myofibroblast in diverse fibrotic lesions, such as systemic sclerosis; kidney, liver, and lung fibrosis; and the stromal reaction to certain epithelial tumors. Finally, we summarize the emerging strategies for influencing myofibroblast behavior in vitro and in vivo, with the ultimate goal of an effective therapeutic approach for myofibroblast-dependent diseases.

Molecular mechanisms and treatment strategies for Dupuytren's disease

Dupuytren’s disease (DD) is a common disease of the hand and is characterized by thickening of the palmar fascia and formation of tight collagenous disease cords. At present, the disease is incurable and the molecular pathophysiology of DD is unknown. Surgery remains the most commonly used treatment for DD, but this requires extensive postoperative therapy and is associated with high rates of recurrence. Over the past decades, more indepth exploration of the molecular basis of DD has raised the hopes of developing new treatment modalities. This paper reviews the clinical presentation and molecular pathophysiology of this disease, as well as current and emerging treatment. It also explores the implications of new findings in the laboratory for future treatment.

Collagenase injection as nonsurgical treatment of Dupuytren's disease: 8-year follow-up

PURPOSE

Collagenase has been investigated in phase II and phase III clinical trials for the treatment of Dupuytren's disease. The purpose of this study is to report 8-year follow-up results in a subset of patients who had collagenase injection for the treatment of Dupuytren's contracture.

METHODS

Twenty-three patients who participated in the phase II clinical trial of injectable collagenase were contacted by letter and phone. Eight patients were enrolled, completed a Dupuytren's disease questionnaire, and had independent examination of joint motion by a single examiner.

RESULTS

Eight patients completed the 8-year follow-up study: 6 had been treated for isolated metacarpophalangeal (MCP) joint contracture, and 2 had been treated for isolated proximal interphalangeal (PIP) joint contracture. Average preinjection contracture was 57 degrees in the MCP group. Average contracture was 9 degrees at 1 week, 11 degrees at 1 year, and 23 degrees at 8-year follow-up. Four of 6 patients experienced recurrence, and 2 of 6 had no evidence of disease recurrence at 8-year follow-up. Average preinjection contracture was 45 degrees in the PIP group. Average contracture was 8 degrees at 1 weeks, 15 degrees at 1 year, and 60 degrees at 8-year follow-up. Both patients experienced recurrence at 8-year follow-up. No patients had had further intervention on the treated finger in either the MCP or the PIP group. Patients subjectively rated the overall clinical success at 60%, and 88% of patients stated that they would pursue further injection for the treatment of their recurrent or progressive Dupuytren's disease.

CONCLUSIONS

Enzymatic fasciotomy is safe and efficacious, with initial response to injection resulting in reduction of joint contracture to within 0 degrees -5 degrees of normal in 72 out of 80 patients. Initial evaluation of long-term recurrence rates suggests disease recurrence or progression in 4 out of 6 patients with MCP contractures and 2 patients with PIP contractures; however, recurrence was generally less severe than the initial contracture in the MCP group. In addition, patient satisfaction was high.

Prevention and management of hypertrophic scars and keloids after burns in children

Hypertrophic scars and keloids are challenging to manage, particularly as sequelae of burns in children in whom the psychologic burden and skin characteristics differ substantially from adults. Prevention of hypertrophic scars and keloids after burns is currently the best strategy in their management to avoid permanent functional and aesthetical alterations. Several actions can be taken to prevent their occurrence, including parental and children education regarding handling sources of fire and flammable materials, among others. Combination of therapies is the mainstay of current burn scar management, including surgical reconstruction, pressure therapy, silicon gels and sheets, and temporary garments. Other adjuvant therapies such as topical imiquimod, tacrolimus, and retinoids, as well as intralesional corticosteroids, 5-fluorouracil, interferons, and bleomycin, have been used with relative success. Cryosurgery and lasers have also been reported as alternatives. Newer treatments aimed at molecular targets such as cytokines, growth factors, and gene therapy, currently in developing stages, are considered the future of the treatment of postburn hypertrophic scars and keloids in children.

Modulation of the BCL-2/BAX ratio by interferon-γ and hypoxia in human peritoneal and adhesion fibroblasts

OBJECTIVE

To examine the effect of interferon (IFN)-gamma treatment under normal and hypoxic conditions on the BCL-2/BAX ratio of fibroblasts obtained from normal peritoneal and adhesion tissues of the same patients.

DESIGN

Prospective experimental study.

SETTING

University medical center.

PATIENT(S)

Fibroblasts from peritoneum and adhesion tissues of 5 patients.

INTERVENTION(S)

Hypoxia and IFN-gamma treatments of fibroblasts.

MAIN OUTCOME MEASURE(S)

We used the multiplex polymerase chain reaction technique to measure expression of BCL-2 and BAX in normal peritoneal and adhesion fibroblasts exposed to hypoxia (2% O(2)), in the presence or absence of IFN-gamma for different time points and dosages.

RESULT(S)

At baseline, adhesion fibroblasts manifested decreased basal levels of apoptosis compared with normal fibroblasts. Hypoxia treatment resulted in a time-response decrease in apoptosis in both cell lines. Interferon-gamma treatment resulted in a dose-response increase in apoptosis in both cell lines. Hypoxia had a reduced or no effect on apoptosis in the presence of increasing doses of IFN-gamma in both cell types.

CONCLUSION(S)

Interferon-gamma can block the effects of hypoxia on apoptosis, supporting the antifibrogenic nature of this cytokine. This suggests that IFN-gamma would be a good candidate for consideration for intervention in the development of peritoneal adhesions and fibrosis.

Laser in the treatment of hypertrophic burn scars

This prospective study looked at the outcome of laser (light amplification by stimulated emission of radiation) treatment for hypertrophic scarring. Dermatrade mark K laser (a set of combined lasers erbium:yttrium aluminium garnet/carbon dioxide, qualified as a class IV laser) was used. Between 21 June 2000 and 19 November 2002, at the Siemianowice Burn Center, Poland, 592 interventions, using laser, were performed on N= 327 patients (220 women and 107 men, aged between 3 and 80 years). The majority of cases [N= 223 (68.9%)] were patients with post-burn hypertrophic scars, and 104 cases (31.8%) had various types of hypertrophic scars. Evaluation took place using an adapted Vancouver Scar Scale and digital photographs as well as the patient's opinion. It was noted that after laser treatment, satisfactory results were achieved in 72% of cases. The scars had become less red (192/327 scored no redness at the end of the study versus 92/327 upon initial), less raised (272/327 scored a flat scar versus 72/327 upon initial) and demonstrated an improved viscoelasticity (192/327 scored a soft skin versus 62/327 upon initial). Laser treatment did not improve contractures in post-burn hypertrophic scars. Results were not confirmed using objective measurement tools, as these were not available to us.

Acquired stenosis of normally connected pulmonary veins

Pulmonary venous stenosis has been a challenge to paediatric cardiologists and surgeons. In spite of significant improvements in the management and outcome of various congenital cardiac problems, the prognosis of this condition continues to be dismal. Acquired stenosis of the pulmonary veins has been described in the adult population, especially after radiofrequency ablation for atrial arrhythmias. The outcome of this condition has generally been described to be favourable in the long term. Acquisition of pulmonary venous stenosis in childhood has a very different outcome, and is not a very well recognised entity, with symptoms and signs which are non-specific. We present 7 infants who, when first assessed, had normal pulmonary veins, but who subsequently acquired stenoses of the veins, with very significant resultant morbidity and mortality.

Opposite effects of TGF-?1 and IFN-? on transdifferentiation of myofibroblast in human gingival cell cultures

BACKGROUND/AIM

Previously, we have shown that myofibroblasts, the main cell type associated with interstitial fibrosis, may be implicated with the gingival overgrowth observed in hereditary gingival fibromatosis (HGF) patients. The goal of this study was to determine whether transforming growth factor-beta1 (TGF-beta1) stimulates myofibroblast generation in gingival fibroblast cultures. Moreover, we analysed how interferon-gamma (IFN-gamma) interferes in this process.

MATERIAL AND METHODS

Fibroblast cultures from normal gingiva and myofibroblast cells from HGF were included in this study. To determine the effects of TGF-beta1 and IFN-gamma stimulation in these cells, the expression of the specific myofibroblast marker smooth muscle isoform of alpha-actin (alpha-SMA) was examined by semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR), Western blot and immunofluorescence. Enzyme-linked immunosorbent assay (ELISA) for type I collagen was performed to measure the myofibroblast activity.

RESULTS

Our results demonstrated that TGF-beta1 promotes a dose- and time-dependent increase in the expression of alpha-SMA, whereas IFN-gamma blocks it and markedly prevents the fibroblast-myofibroblast switch induced by TGF-beta1 on normal gingiva cultures. IFN-gamma altered HGF myofibroblasts metabolism with a decrease of both alpha-SMA and type I collagen expression. Additionally, IFN-gamma treatment stimulated SMAD7 expression and inhibited connective tissue growth factor, which has been considered a key molecule to promote the transdifferentiation of myofibroblasts via TGF-beta1 activation.

CONCLUSIONS

These findings demonstrate that TGF-beta1 induces gingival fibroblast-myofibroblast transdifferentiation, whereas IFN-gamma blocks this process. More importantly, this study suggests that IFN-gamma may be clinically effective in attenuating excessive accumulation of extracellular matrix produced by myofibroblasts in HGF.

Off-label uses of biologics in dermatology: Interferon and intravenous immunoglobulin (Part 1 of 2)

The introduction of a number of biologic therapies into the market has revolutionized the practice of dermatology. These therapies include interferons, intravenous immunoglobulin, infliximab, adalimumab, etanercept, efalizumab, alefacept, and rituximab. Most dermatologists are familiar with the Food and Drug Administration-approved indications of these medications. However, numerous off-label uses have evolved. As part 1 of a 2-part series, this article will review the literature regarding the off-label uses of the interferons and intravenous immunoglobulin in dermatology.

Factors in the pathogenesis of Dupuytren's contracture

This article reviews the basic science elements involved in the pathogenesis of Dupuytren's disease. Dupuytren's contracture is effected by a multitude of complex processes at the cellular level and the exact relative contribution of each is unknown. Various investigators have proposed different theories and documented individual findings regarding the pathophysiology of Dupuytren's contracture. The current report attempts to summarize many of these findings together in a schema of pathogenesis.

Antifibrogenic effects of liposome-encapsulated IFN-alpha2b cream on skin wounds in a fibrotic rabbit ear model

This study was conducted to assess the ability of a dermal cream containing liposome-encapsulated interferon- alpha2b (IFN-alpha2b) (LIPO+IFN) to improve hypertrophic scarring in open and reepithelialized dermal wounds in a rabbit fibrotic ear model. Full-thickness skin wounds were made in New Zealand white rabbits, and were either left untreated, treated on day 16 postsurgery (open wound), or treated on day 23 postsurgery (reepithelialized wound) with either LIPO+IFN or liposome alone (LIPO). The conditions of the wounds were monitored until day 35 postsurgery, when hypertrophic scar formation reached its peak. Dry wound weight, scar thickness, hypertrophic index (HI), and tissue cellularity of treated and untreated wounded tissue samples were evaluated as an index for scar formation. The results of this study showed that reepithelialized wounds treated with LIPO+IFN and to a lesser extent with LIPO alone were reduced in thickness, HI, and cellularity compared with untreated control wounds or LIPO+IFN-treated open wounds. Dry wound weight was also reduced but not significantly. The findings of this study suggest that LIPO+IFN is more effective than using LIPO alone in reducing the scar formation in a rabbit fibrotic ear model. Further investigation is required to confirm these results.

Significance of the cytokine interferon gamma in clinical dermatology

Interferon (IFN)-gamma is considered a key cytokine of innate and adaptive immunity playing pivotal roles in host defence against microbial pathogens and tumours, and exerts profound antiproliferative and antifibrotic effects. In this review we discuss applications and perspectives of IFN-gamma in clinical dermatology, such as papillomavirus and bacterial infections, tumours, atopic dermatitis, and fibrotic conditions such as scleroderma and postradiation fibrosis. Moreover, we give a summary of the pharmacologic properties including main side effects and potential risk factors of IFN-gamma therapy. Although former enthusiasm for IFN-gamma (e.g. in atopic dermatitis) has subsided, this cytokine might remain a promising tool (and target) in clinical dermatology, due to its central immunobiologic functions, better characterization of its kinetics in diseases facilitating optimized treatment schedules, and successful applications in fibrotic conditions such as scleroderma, idiopathic pulmonary and skin postradiation fibrosis.

The fibroblast-populated collagen matrix as a model of wound healing: a review of the evidence

The fibroblast-populated collagen matrix (FPCM) has been utilized as an in vitro model of wound healing for more than 2 decades. It offers a reasonable approximation of the healing wound during the phases of established granulation tissue and early scar. The gross and microscopic morphology of the FPCM and the healing wound are similar at analogous phases. The processes of proliferation, survival/apoptosis, protein synthesis, and contraction act in similar directions in these two models, and the response to exogenous agents also is consistent between them. If its limitations are respected, then the FPCM can be used as a model of the healing wound.

Inhibition of induction of myofibroblasts by interferon gamma in a human fibroblast cell line

Interferon gamma (IFNgamma) has been reported as a possible therapeutic agent for contractile diseases in clinical trials and in vitro studies. It is not yet clear, however, whether IFNgamma simply inhibits myofibroblast generation or downregulates alpha smooth muscle actin (alphaSMA) production in myofibroblasts. In this study, we attempted to clarify how IFNgamma acts in the generation of myofibroblasts, and the production of alphaSMA by myofibroblasts, using immunofluorescence staining, cell capture enzyme immunoassay (CC-EIA) and the reverse transcription polymerase chain reaction (RT-PCR) for alphaSMA. We examined whether IFNgamma could block the TGFbeta1-promoted changes in myofibroblasts or the generation of myofibroblasts by TGFbeta1. IFNgamma strongly blocked the generation of myofibroblasts and moderately inhibited the production of alphaSMA in TGFbeta1-promoted myofibrobasts. These findings indicate that IFNgamma may be effective in the early stage of contractile diseases to prevent the progression of contractile lesions.

Morphometric analysis of the collagen changes induced by subcutaneous injection of interferon-gamma after bladder outlet obstruction in the rat

AIMS

The objective of this study was to examine the effects of interferon-gamma injection on changes in collagen content, after the creation of partial bladder outlet obstruction in the rats.

METHODS

A total of 50 Sprague-Dawley female rats were subjected to partial bladder outlet obstruction by using metal rods. The rats were divided into five groups (n = 10 in each group): normal control (N), sham operation (S), bladder outlet obstruction for 4 weeks (BOO), interferon-gamma injection after sham operation (S + IFN), and interferon-gamma injection after bladder outlet obstruction (BOO + IFN). Interferon-gamma was subcutaneously injected (100,000 units per injection, LG chemical Co., Seoul, Korea) daily for 4 weeks in the injection groups, after which all rats were sacrificed.

RESULTS

The collagen area percentage (collagen/collagen + muscle) in each bladder, calculated through image analysis, was 40.7 +/- 1.6% in the N, 38.2 +/- 2.0% in the S, 26.6 +/- 3.8% in the S + IFN, 19.9 +/- 2.5% in the BOO, and 12.4 +/- 2.0% in the BOO + IFN group (mean +/- standard error). The difference in the collagen area percentage between the N and S groups (P > 0.05) was not significant, but there were significant differences between the N and S + IFN groups (P < 0.05), between the S and S + IFN groups (P < 0.05), and between the BOO and BOO + IFN groups (P < 0.05).

CONCLUSIONS

It appears that interferon-gamma decreases the collagen content in the obstructed rat bladder.

Effects of locally injected interferon-β on palatal mucoperiosteal wound healing

BACKGROUND

Wound contraction and scar formation in the palatal mucoperiosteum after cleft palate surgery impair maxillary growth. The aim of this study was to determine the effects of IFN-beta on palatal mucoperiosteal wound healing in growing rats.

METHODS

Standardized wounds were made in the palatal mucoperiosteum of young rats. Either IFN-beta or vehicle were injected at the wound site between 4 and 29 days after wounding. The results were compared with control wounds. Tissue samples were collected at 8, 15, 30, and 60 days PW for biochemical and microscopic analysis.

RESULTS

IFN-beta stimulated re-epithelialization but did not reduce the number of myofibroblasts or scar tissue formation. Surprisingly, the injection of vehicle alone delayed the healing process.

CONCLUSION

IFN-beta might be suitable to stimulate re-epithelialization but it does not reduce scar tissue formation in rat palatal wound healing. The injection of agents into palatal wounds might severely impair the healing process.

Collagen as a clinical target: nonoperative treatment of Dupuytren's disease

The cellular events leading to abnormal synthesis of collagen are important to our understanding of pathologic processes leading to impaired joint function. The contracture of Dupuytren's disease is a notable example. In a series of controlled phase-2 clinical trials, excessive collagen deposition in Dupuytren's disease has been targeted by a unique nonoperative method using enzyme (Clostridial collagenase) injection therapy to lyse and rupture finger cords causing metacarpophalangeal and/or proximal interphalangeal joint contractures. Forty-nine patients were treated in a random, placebo-controlled trial of one dose of collagenase versus placebo at one center. Subsequently 80 patients were treated in a random, placebo-controlled, dose-response study of collagenase at 2 test centers. The results of these studies indicate that nonoperative collagenase injection therapy for Dupuytren's disease is both a safe and effective method of treating this disorder in the majority of patients as an alternative to surgical fasciectomy. Phase-3 efficacy trials are now being planned to further develop and test this method under Food and Drug Administration regulatory guidelines. The findings of our study may lead to simpler and less invasive nonoperative treatments of joint limitation in which collagen plays a major pathologic role.