Regulation of lysyl oxidase mRNA in dermal fibroblasts from normal donors and patients with inherited connective tissue disorders

Matricellular protein CCN1 promotes collagen alignment and scar integrity after myocardial infarction

BACKGROUND

Members of the cellular communication network family (CCN) of matricellular proteins, like CCN1, have long been implicated in the regulation of cellular processes underlying wound healing, tissue fibrogenesis, and collagen dynamics. While many studies suggest antifibrotic actions for CCN1 in the adult heart through the promotion of myofibroblast senescence, they largely relied on exogenous supplementation strategies in in vivo models of cardiac injury where its expression is already induced-which may confound interpretation of its function in this process. The objective of this study was to interrogate the role of the endogenous protein on fibroblast function, collagen structural dynamics, and its associated impact on cardiac fibrosis after myocardial infarction (MI).

METHODS/RESULTS

Here, we employed CCN1 loss-of-function methodologies, including both in vitro siRNA-mediated depletion and in vivo fibroblast-specific knockout mice to assess the role of the endogenous protein on cardiac fibroblast fibrotic signaling, and its involvement in acute scar formation after MI. In vitro depletion of CCN1 reduced cardiac fibroblast senescence and proliferation. Although depletion of CCN1 decreased the expression of collagen processing and stabilization enzymes (i.e., P4HA1, PLOD1, and PLOD2), it did not inhibit myofibroblast induction or type I collagen synthesis. Alone, fibroblast-specific removal of CCN1 did not negatively impact ventricular performance or myocardial collagen content but did contribute to disorganization of collagen fibrils and increased matrix compliance. Similarly, Ccn1 ablated animals subjected to MI showed no discernible alterations in cardiac structure or function one week after permanent coronary artery ligation, but exhibited marked increases in incidence of mortality and cardiac rupture. Consistent with our findings that CCN1 depletion does not assuage myofibroblast conversion or type I collagen synthesis in vitro, Ccn1 knockout animals revealed no measurable differences in collagen scar width or mass compared to controls; however, detailed structural analyses via SHG and TEM of scar regions revealed marked alterations in their scar collagen topography-exhibiting changes in numerous macro- and micro-level collagen architectural attributes. Specifically, Ccn1 knockout mice displayed heightened ECM structural complexity in post-MI scar regions, including diminished local alignment and heightened tortuosity of collagen fibers, as well as reduced organizational coherency, packing, and size of collagen fibrils. Associated with these changes in ECM topography with the loss of CCN1 were reductions in fibroblast-matrix interactions, as evidenced by reduced fibroblast nuclear and cellular deformation in vivo and reduced focal-adhesion formation in vitro; findings that ultimately suggest CCN1's ability to influence fibroblast-led collagen alignment may in part be credited to its capacity to augment fibroblast-matrix interactions.

CONCLUSIONS

These findings underscore the pivotal role of endogenous CCN1 in the scar formation process occurring after MI, directing the appropriate arrangement of the extracellular matrix's collagenous components in the maturing scar-shaping the mechanical properties that support its structural stability. While this suggests an adaptive role for CCN1 in regulating collagen structural attributes crucial for supporting scar integrity post MI, the long-term protracted expression of CCN1 holds maladaptive implications, potentially diminishing collagen structural complexity and compliance in non-infarct regions.

Recurrence rates in the treatment of keloids and hypertrophic scars with intralesional triamcinolone combined with other intralesional agents

Hypertrophic scars (HTS) and keloids are pathologic scars that are products of a wound healing pathway error attributed to genetic and inflammatory causes (Leventhal et al., Arch Facial Plast Surg 8(6):362-368. https://doi.org/10.1001/archfaci.8.6.362 , 2006). Methods of pathologic scar treatment include intralesional agents, cryotherapy, surgical excision, pressure dressings, topical agents, laser resurfacing, radiotherapy, and other investigational therapies (Leventhal et al. 2006). The recurrence of pathologic scar is high across all treatment modalities, including the use of intralesional agents (Trisliana Perdanasari et al., Arch Plast Surg 41(6):620-629. https://doi.org/10.5999/aps.2014.41.6.620 , 2014). In the treatment of pathologic scar, combination approaches using intralesional agents, such as triamcinolone (TAC), 5-fluorouracil (5FU), verapamil (VER), bleomycin (BLM), and botulinum toxin (BTX), are superior therapies when compared to monotherapy (Yosipovitch et al., J Dermatol Treat 12(2):87-90. https://doi.org/10.1080/095466301317085363 , 2001; Yang et al., Front Med 8:691628. https://doi.org/10.3389/fmed.2021.691628 , 2021; Sun et al., Aesthetic Plast Surg 45(2):791-805. https://doi.org/10.1007/s00266-019-01570-8 , 2021). This review assesses recurrence and the reporting of recurrence in pathologic scar after treatment with intralesional triamcinolone (TAC) in combination with another intralesional agent. A literature review was conducted using research journals from PubMed using the following search terms: [(keloid) AND (triamcinolone) AND (combination) AND (intralesional)], as well as [(keloid) AND (triamcinolone) AND (combination)]. Articles were reviewed and included if the article analyzed  or compared intralesional agents for pathologic scar treatment within the last 10 years. The average follow-up period of included articles (n = 14) that utilized combination intralesional therapy (TAC-X) was approximately 11 months (range 1-24 months). Consistent recurrence rate reporting across studies was lacking. The combination agent with the highest recurrence rate was TAC-5FU (23.3%). The range of reported recurrence rates was 7.5-23.3%. Six studies using various intralesional combination regimens reported 0% recurrence over the follow-up period (TAC-5FU, TAC-BTX, TAC-BLM, TAC-CRY). Three studies did not report recurrence rates. While the efficacy of combination therapy is typically assessed via scar scales, the assessment of recurrence across studies of combination therapy is inconsistent and inadequate, with truncated follow-up periods. While scar recurrence can take place during 1-year post-treatment, long-term follow-up (18-24 months) is needed to characterize recurrence in the treatment of pathologic scar using various intralesional agents. Long-term follow-up periods allow patients to receive accurate prognostic information regarding recurrence after combination intralesional therapy. There are limitations to this review in that comparisons were made across studies with varying outcome variables, including scar size, injection concentration and interval, and follow-up period. Standardized follow-up periods and recurrence rate reporting are integral to furthering the understanding of these therapies and enhancing patient care.

Nuclear medicine in the management of superficial skin abnormalities and institutional experience

Keloid, hypertrophic scars and basal cell carcinoma (BCC) falls under the category of non-melanoma skin cancer. Intralesional steroids, external beam radiation therapy, 5-Fluorouracil, cryotherapy, laser, etc are the available treatment options. However, recurrence has been reported with each type of treatment mode. In the present article, various treatment modes have been discussed and institutional experience of Rhenium-188 skin patches for the treatment of keloids and BCC has been discussed.

The effectiveness of long Pulsed Nd:YAG Laser alone for treatment of keloids and hypertrophic scars versus its combination with bleomycin

BACKGROUND AND OBJECTIVES

Pathological scars are benign hyper-proliferative growths of dermal collagen that causes severe psychological and physical problems. This study was performed to assess and compare safety and clinical efficiency of combined pulsed Nd-YAG laser and intralesional bleomycin versus pulsed Nd-YAG laser alone to treat the hypertrophic scars and keloids.

PATIENTS AND METHODS

Randomly, 40 patients with hypertrophic scars or keloids were divided into two groups A and B. Group A were handled by pulsed Nd:YAG laser and intralesional bleomycin while group B were handled by pulsed Nd:YAG laser only. Response was assessed subjectively by clinical imaging and modified Vancouver Scar Scale (mVSS). While for objective evaluation, skin biopsies were taken from volunteer patients before and after treatment, and were examined by Hematoxylin and eosin staining (H&E) and Masson trichrome staining.

RESULTS

Our study demonstrated almost complete improvement in 4 (20%) patients, partial improvement in 16 (80%) patients and 0 patient with no improvement in group A. Furthermore, in group B, we demonstrated almost complete improvement in 2 (10%) patients, partial in 14 (70%) patients and no improvement in 4 (20%) patients. Modified Vancouver Scar Scale reduced from 10.15 to 3.5 in group A and from 11.05 to 4.95 in group B. Elastica Masson-Goldner staining and Hematoxylin and eosin staining showed that treatment in both groups structurally changed tissue collagen.

CONCLUSION

Long-pulsed Nd-YAG laser combined with intralesional bleomycin could be a promising way for treatment of keloids or hypertrophic scars.

Hypertrophic scars and keloids: a review and current treatment modalities

Hypertrophic scars (HTS) are raised, red, rigid, inflexible cell-like, and cosmetic problems precipitated due to multiple underlying dermal injuries such as burn, surgery, and trauma during which aberrant wound healing with more pathological deposition of the extracellular matrix than degradation leads to their spawning. Till date, well established and specific treatments for HTS have not been reported; hence, the need of recent developments is thrusted with novel drug delivery vision. This review will try to encompass all the agogs to HTS, definition, pathophysiology, mechanism of hypertrophic scar formation, the role of growth factors in hypertrophic scarring, and their difference with keloids. Further, it will illuminate the available medicaments and recent advances in novel topical drug delivery systems such as ethosomes, transethosomes, liposomes, solid lipid nanoparticles, and microsponges for treatment of HTS.

Keloids: Current and emerging therapies

Keloids are pathological scars that grow over time and extend beyond the initial site of injury after impaired wound healing. These scars frequently recur and rarely regress. They are aesthetically disfiguring, can cause pain, itching, discomfort as well as psychological stress, often affecting quality of life. Many treatment modalities, including surgical and non-surgical, have been explored and have been reported to be beneficial; however, none have been absolutely satisfactory or optimal for the treatment of all keloid subtypes to date. This poses a major challenge to clinicians. Often, a combinational therapeutic approach appears to offer the best results with higher patient satisfaction compared to monotherapy. The aetiopathogenesis of keloids is not fully elucidated; however, with recent advances in molecular biology and genetics, insight is being gained on the complex process of scar formation and hence new therapeutic and management options for keloids. In this paper, we explore the literature and summarise the general concepts surrounding keloid development and review both current (corticosteroids, surgical excision, silicone-based products, pressure therapy, radiotherapy, cryotherapy, laser therapy, imiquimod and 5-fluorouracil) and emerging (stem cell therapy, mitomycin C, verapamil, interferons, bleomycin, botulinum toxin type A and angiotensin-converting enzyme inhibitors) treatments. Increased knowledge and understanding in this area may potentially lead to the discovery and development of novel therapeutic options that are more efficacious for all keloid types.

LAY SUMMARY

Keloids are problematic scars that are difficult to treat and manage. The aetiopathogenesis of keloids is not clear; however, recent advances in molecular biology and genetics are beginning to shed light on the underlying mechanisms implicated in keloid scar formation which will hopefully lead to the development of treatment options for all keloid types. This review summarises current and emerging therapies.

CCN1 expression by fibroblasts is required for bleomycin-induced skin fibrosis

The microenvironment contributes to the excessive connective tissue deposition that characterizes fibrosis. Members of the CCN family of matricellular proteins are secreted by fibroblasts into the fibrotic microenvironment; however, the role of endogenous CCN1 in skin fibrosis is unknown. Mice harboring a fibroblast-specific deletion for CCN1 were used to assess if CCN1 contributes to dermal homeostasis, wound healing, and skin fibrosis. Mice with a fibroblast-specific CCN1 deletion showed progressive skin thinning and reduced accumulation of type I collagen; however, the overall mechanical property of skin (Young's modulus) was not significantly reduced. Real time-polymerase chain reaction analysis revealed that CCN1-deficient skin displayed reduced expression of mRNAs encoding enzymes that promote collagen stability (including prolyl-4-hydroxylase and PLOD2), although expression of COL1A1 mRNA was unaltered. CCN1-deficent skin showed reduced hydroxyproline levels. Electron microscopy revealed that collagen fibers were disorganized in CCN1-deficient skin. CCN1-deficient mice were resistant to bleomycin-induced skin fibrosis, as visualized by reduced collagen accumulation and skin thickness suggesting that deposition/accumulation of collagen is impaired in the absence of CCN1. Conversely, CCN1-deficient mice showed unaltered wound closure kinetics, suggesting de novo collagen production in response to injury did not require CCN1. In response to either wounding or bleomycin, induction of α-smooth muscle actin-positive myofibroblasts was unaffected by loss of CCN1. CCN1 protein was overexpressed by dermal fibroblasts isolated from lesional (i.e., fibrotic) areas of patients with early onset diffuse scleroderma. Thus, CCN1 expression by fibroblasts, being essential for skin fibrosis, is a viable anti-fibrotic target.

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The role of endogenous CCN1 in skin biology is largely unknown

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Fibroblast-specific deletion CCN1 causes thinner skin and misaligned collagen

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CCN1-deficient mice were resistant to bleomycin-induced skin fibrosis

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Wound healing closure kinetics was unaffected by loss of CCN1

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CCN1 may be as a target for anti-fibrotic therapy

Remodeling of the Collagen Matrix in Aging Skin Promotes Melanoma Metastasis and Affects Immune Cell Motility

Physical changes in skin are among the most visible signs of aging. We found that young dermal fibroblasts secrete high levels of extracellular matrix (ECM) constituents, including proteoglycans, glycoproteins, and cartilage-linking proteins. The most abundantly secreted was HAPLN1, a hyaluronic and proteoglycan link protein. HAPLN1 was lost in aged fibroblasts, resulting in a more aligned ECM that promoted metastasis of melanoma cells. Reconstituting HAPLN1 inhibited metastasis in an aged microenvironment, in 3-D skin reconstruction models, and in vivo. Intriguingly, aged fibroblast-derived matrices had the opposite effect on the migration of T cells, inhibiting their motility. HAPLN1 treatment of aged fibroblasts restored motility of mononuclear immune cells, while impeding that of polymorphonuclear immune cells, which in turn affected regulatory T-cell recruitment. These data suggest that although age-related physical changes in the ECM can promote tumor cell motility, they may adversely affect the motility of some immune cells, resulting in an overall change in the immune microenvironment. Understanding the physical changes in aging skin may provide avenues for more effective therapy for older patients with melanoma. SIGNIFICANCE: These data shed light on the mechanochemical interactions that occur between aged skin, tumor, and immune cell populations, which may affect tumor metastasis and immune cell infiltration, with implications for the efficacy of current therapies for melanoma.See related commentary by Marie and Merlino, p. 19.This article is highlighted in the In This Issue feature, p. 1.

Recent Understandings of Biology, Prophylaxis and Treatment Strategies for Hypertrophic Scars and Keloids

Hypertrophic scars and keloids are fibroproliferative disorders that may arise after any deep cutaneous injury caused by trauma, burns, surgery, etc. Hypertrophic scars and keloids are cosmetically problematic, and in combination with functional problems such as contractures and subjective symptoms including pruritus, these significantly affect patients’ quality of life. There have been many studies on hypertrophic scars and keloids; but the mechanisms underlying scar formation have not yet been well established, and prophylactic and treatment strategies remain unsatisfactory. In this review, the authors introduce and summarize classical concepts surrounding wound healing and review recent understandings of the biology, prevention and treatment strategies for hypertrophic scars and keloids.

Nutraceuticals: A Review

Skin aging is continuously influenced by various internal and external factors such as the biologic progression of cells, ultraviolet (UV) radiation, tobacco, nutritional deficiencies, and hormonal imbalances that lead to the degradation of skin cells. Through the degradation of skin cells, free radicals and inflammation weaken repair mechanisms and result in collagen and elastic fiber breakdown. The appearance of aging skin is highlighted by skin roughness, wrinkling, pigmentation change, telangiectasias, loss of elasticity, and decreased firmness, all of which are accelerated by these internal and external factors. Throughout the years, nutraceuticals have been studied to delay and fight against these internal and external factors, many of which are found in foods and byproducts consumed naturally. The aim of this review is to aid dermatologists in understanding the mechanism of action of popular nutraceuticals and their possible efficacy in antiaging and skin health.

Induction of apoptosis in nasal polyp-derived fibroblasts by bleomycin A5 in vitro

The present study aimed to evaluate the pro-apoptotic effects of bleomycin A5 on nasal polyp‑derived fibroblasts (NPDFs) and the underlying molecular mechanisms. Nasal polyp tissue was acquired from 10 patients during surgery and NPDFs were isolated from surgical tissues. Fibroblasts were identified using immunohistochemistry. Bleomycin A5 was used to treat NPDFs along a concentration gradient. Cell viability was evaluated using a Cell Counting Kit‑8 assay. A flow cytometric Annexin V‑fluorescein isothiocyanate/propidium iodide assay was used to determine the percentage of apoptotic NPDFs. The mRNA expression levels of apoptotic genes were determined by reverse transcription‑quantitative polymerase chain reaction and levels of proteins associated with apoptosis were determined by western blotting. The results indicated that bleomycin A5 was able to induce apoptosis in NPDFs in a dose‑dependent manner. NPDFs treated with bleomycin A5 were identified to contain significantly high amounts of the active forms of caspase‑3 and showed considerable cleavage of poly(ADP‑ribose) polymerase. The mRNA and protein expression levels of the pro‑apoptotic molecule Bcl‑2‑associated X protein were significantly higher in treated NPDFs than in untreated NPDFs. In contrast, the mRNA and protein expression of the anti‑apoptotic molecule B‑cell lymphoma 2 (Bcl‑2) was significantly lower in treated NPDFs. These results indicated that bleomycin A5 could induce apoptosis in primary NPDFs through activation of the Bcl‑2 family and caspase cascades in a time-, and concentration-dependent manner.

Pathophysiologic Mechanisms and Current Treatments for Cutaneous Sequelae of Burn Wounds

Burn injuries are a pervasive clinical problem. Extensive thermal trauma can be life-threatening or result in long-lasting complications, generating a significant impact on quality of life for patients as well as a cost burden to the healthcare system. The importance of addressing global or systemic issues such as resuscitation and management of inhalation injuries is not disputed but is beyond the scope of this review, which focuses on cutaneous pathophysiologic mechanisms for current treatments, both in the acute and long-term settings. Pathophysiological mechanisms of burn progression and wound healing are mediated by highly complex cascades of cellular and biochemical events, which become dysregulated in slow-healing wounds such as burns. Burns can result in fibroproliferative scarring, skin contractures, or chronic wounds that take weeks or months to heal. Burn injuries are highly individualized owing to wound-specific differences such as burn depth and surface area, in addition to patient-specific factors including genetics, immune competency, and age. Other extrinsic complications such as microbial infection can complicate wound healing, resulting in prolonged inflammation and delayed re-epithelialization. Although mortality is decreasing with advancements in burn care, morbidity from postburn deformities continues to be a challenge. Optimizing specialized acute care and late burn outcome intervention on a patient-by-patient basis is critical for successful management of burn wounds and the associated pathological scar outcome. Understanding the fundamentals of integument physiology and the cellular processes involved in wound healing is essential for designing effective treatment strategies for burn wound care as well as development of future therapies. Published 2018. Compr Physiol 8:371-405, 2018.

Crosslinking Enzyme Lysyl Oxidase Modulates Scleral Remodeling in Form-Deprivation Myopia

PURPOSE

Scleral remodeling causes the excessive ocular elongation that underlies myopia. Lysyl oxidase (LOX), a copper-containing amine oxidase, can catalyze collagen and elastin crosslinking. The purpose of this study was to investigate the role of LOX in scleral remodeling in form-deprivation myopia (FDM).

METHODS

Seventy-five guinea pigs were randomly divided into five groups as follows: a normal control group, an FDM group, an FDM plus β-aminopropionitrile (BAPN) group, an FDM plus TGF-β1 (TGF-β1) group, and an FDM plus vehicle group. A translucent diffuser was used to induce FDM, and intravitreal injection was used to administer BAPN, TGF-β1 or vehicle. The scleral LOX and collagen gene and protein levels and the posterior scleral ultrastructure and biomechanics were measured.

RESULTS

In the FDM group, both the scleral LOX and collagen gene and protein levels were significantly lower than those in the control eyes. The collagen fibril diameters were significantly decreased in the FDM group compared with the diameters in the control group. A significant decrease in LOX gene and protein expression was observed after BAPN injection, and an increase was observed after TGF-β1 treatment compared with the levels in the FDM group. Additionally, the scleral collagen fibrils were significantly decreased in the BAPN-treated eyes but increased in the TGF-β1-treated eyes compared with the FDM eyes. The ultimate stress and Young's modulus of the sclera were lowest in the BAPN group, followed by the FDM group and the TGF-β1 group. The ultimate strain (%) of the sclera was lowest in the TGF-β1 group, followed by the FDM group and the BAPN group.

CONCLUSION

LOX expression was significantly lowered in myopic sclera. Modulating LOX expression induced a change in both the scleral collagen fibril diameter and the scleral biomechanics. Therefore, LOX may play a key role in the myopia scleral remodeling procedure.

Keloids and Hypertrophic Scars: Pathophysiology, Classification, and Treatment

BACKGROUND

Keloid and hypertrophic scars represent an aberrant response to the wound healing process. These scars are characterized by dysregulated growth with excessive collagen formation, and can be cosmetically and functionally disruptive to patients.

OBJECTIVE

Objectives are to describe the pathophysiology of keloid and hypertrophic scar, and to compare differences with the normal wound healing process. The classification of keloids and hypertrophic scars are then discussed. Finally, various treatment options including prevention, conventional therapies, surgical therapies, and adjuvant therapies are described in detail.

MATERIALS AND METHODS

Literature review was performed identifying relevant publications pertaining to the pathophysiology, classification, and treatment of keloid and hypertrophic scars.

RESULTS

Though the pathophysiology of keloid and hypertrophic scars is not completely known, various cytokines have been implicated, including interleukin (IL)-6, IL-8, and IL-10, as well as various growth factors including transforming growth factor-beta and platelet-derived growth factor. Numerous treatments have been studied for keloid and hypertrophic scars,which include conventional therapies such as occlusive dressings, compression therapy, and steroids; surgical therapies such as excision and cryosurgery; and adjuvant and emerging therapies including radiation therapy, interferon, 5-fluorouracil, imiquimod, tacrolimus, sirolimus, bleomycin, doxorubicin, transforming growth factor-beta, epidermal growth factor, verapamil, retinoic acid, tamoxifen, botulinum toxin A, onion extract, silicone-based camouflage, hydrogel scaffold, and skin tension offloading device.

CONCLUSION

Keloid and hypertrophic scars remain a challenging condition, with potential cosmetic and functional consequences to patients. Several therapies exist which function through different mechanisms. Better understanding into the pathogenesis will allow for development of newer and more targeted therapies in the future.

The Use of Chemotherapeutics for the Treatment of Keloid Scars

Keloid scars are pathological scars, which develop as a result of exaggerated dermal tissue proliferation following cutaneous injury and often cause physical, psychological and cosmetic problems. Various theories regarding keloidogenesis exist, however the precise pathophysiological events remain unclear. Many different treatment modalities have been implicated in their management, but currently there is no entirely satisfactory method for treating all keloid lesions. We review a number of different chemotherapeutic agents which have been proposed for the treatment of keloid and hypertrophic scars while giving insight into some of the novel chemotherapeutic drugs which are currently being investigated. Non-randomized trials evaluating the influence of different chemotherapeutic agents, such as 5-fluorouracil (5-FU); mitomycin C; bleomycin and steroid injection, either alone or in combination with other chemotherapeutic agents or alternative treatment modalities, for the treatment of keloids were identified using a predefined PubMed search strategy. Twenty seven papers were identified. Scar improvement ≥50% was found in the majority of cases treated with 5-FU, with similar results found for mitomycin C, bleomycin and steroid injection. Combined intralesional 5-FU and steroid injection produced statistically significant improvements when compared to monotherapy. Monotherapy recurrence rates ranged from 0-47% for 5-FU, 0-15% for bleomycin and 0-50% for steroid injection. However, combined therapy in the form of surgical excision and adjuvant 5-FU or steroid injections demonstrated lower recurrence rates; 19% and 6% respectively. Currently, most of the literature supports the use of combination therapy (usually surgery and adjuvant chemotherapy) as the mainstay treatment of keloids, however further investigation is necessary to determine success rates over longer time frames. Furthermore, there is the potential for novel therapies, but further investigation is required to elucidate their true efficacy.

Elevated expression levels of lysyl oxidases protect against aortic aneurysm progression in Marfan syndrome

Patients with Marfan syndrome (MFS) are at high risk of life-threatening aortic dissections. The condition is caused by mutations in the gene encoding fibrillin-1, an essential component in the formation of elastic fibers. While experimental findings in animal models of the disease have shown the involvement of transforming growth factor-β (TGF-β)- and angiotensin II-dependent pathways, alterations in the vascular extracellular matrix (ECM) may also play a role in the onset and progression of the aortic disease. Lysyl oxidases (LOX) are extracellular enzymes, which initiates the formation of covalent cross-linking of collagens and elastin, thereby contributing to the maturation of the ECM. Here we have explored the role of LOX in the formation of aortic aneurysms in MFS. We show that aortic tissue from MFS patients and MFS mouse model (Fbn1(C1039G/+)) displayed enhanced expression of the members of the LOX family, LOX and LOX-like 1 (LOXL1), and this is associated with the formation of mature collagen fibers. Administration of a LOX inhibitor for 8weeks blocked collagen accumulation and aggravated elastic fiber impairment, and these effects correlated with the induction of a strong and rapidly progressing aortic dilatation, and with premature death in the more severe MFS mouse model, Fbn1(mgR/mgR), without any significant effect on wild type animals. This detrimental effect occurred preferentially in the ascending portion of the aorta, with little or no involvement of the aortic root, and was associated to an overactivation of both canonical and non-canonical TGF-β signaling pathways. The blockade of angiotensin II type I receptor with losartan restored TGF-β signaling activation, normalized elastic fiber impairment and prevented the aortic dilatation induced by LOX inhibition in Fbn1(C1039G/+) mice. Our data indicate that LOX enzymes and LOX-mediated collagen accumulation play a critical protective role in aneurysm formation in MFS.

The treatment of keloids and hypertrophic scars with intralesional bleomycin in skin of color

Intralesional injection with corticosteroid remains the mainstay of therapy for hypertrophic scars and keloids, however some lesions are unresponsive or may result in skin atrophy. Intralesional bleomycin injection is an alternative therapy that has been widely reported. In order to compare the effectiveness and safety of bleomycin for the treatment of keloids and hypertrophic scars in skin of color population, Fitzpatrick skin type III to V patients with keloids or hypertrophic scars were randomized into two groups. Group A was treated monthly with intralesional triamcinolone acetonide (10 mg/mL), while group B with intralesional bleomycin (1 mg/mL) for three consecutive months. Evaluation of the treatment was performed using "Patient and Observer Scar Assessment Scale" (POSAS), self-rated patient satisfaction score, photography, and ultrasonography. Two patients had their bleomycin blood levels monitored. Twenty-six patients with keloids or hypertrophic scars were recruited. The clinical improvement as assessed by the POSAS was not statistically significant. In terms of patients satisfaction score, one half of both groups reported a very good improvement. Photographic as well as ultrasonographic evaluation showed no difference between the two groups. Bleomycin was found to enter the blood circulation in a very small amount. The major side effect was hyperpigmentation. There was no skin atrophy detected in this study. Intralesional bleomycin is a safe and effective treatment for keloids and hypertrophic scars. The treatment is comparable to intralesional triamcinolone. Unfortunately, hyperpigmentation was the major side effect in darker skin type.

Results of a combination of bleomycin and triamcinolone acetonide in the treatment of keloids and hypertrophic scars

While treatment of keloids and hypertrophic scars normally shows modest results, we found that treatment with bleomycin was more promising. The present study was divided into two parts. In the first part the aim was to show the results using a combination of bleomycin and triamcinolone acetonide per cm² (BTA). In the second part the objective was to determine the response to both drugs in large keloids that were divided into 1 cm² squares, treating each square with the dose previously used. In the first part of the study, the clinical response of 37 keloids ranging from 0.3 to 1.8 cm² treated with BTA were followed up over a period of 1- 2 years. 0.375 IU bleomycin and 4 mg triamcinolone acetonide were injected every 3 months. In the second part of the study we reviewed the clinical response in six patients with large keloids. The monthly dose administered never exceeded 3 IU of bleomycin. The first study showed 36 keloids (97.29%) softening after the first dose. In the second study, 5 showed different responses (the response was complete in the four smaller keloids). The largest keloid needed 9 doses to achieve an improvement of 70%. In conclusion, combined treatment with 0.375 IU of bleomycin and 4mg of triamcinolone acetonide to 1 cm² was considered to be an acceptable procedure for the treatment of keloids. The best results were obtained in keloids over 1 cm² or when divided into 1 cm² square areas. Larger series need to be performed in order to confirm these results..

Potassium channel openers increase aortic elastic fiber formation and reverse the genetically determined elastin deficit in the BN rat

Hypertension is a cardiovascular disorder that appears in more than half of the patients with Williams-Beuren syndrome, hemizygous for the elastin gene among 26 to 28 other genes. It was shown that the antihypertensive drug minoxidil, an ATP-dependent potassium channel opener, enhances elastic fiber formation; however, no wide clinical application was developed because of its adverse side effects. The Brown Norway rat was used here as an arterial elastin-deficient model. We tested 3 different potassium channel openers, minoxidil, diazoxide, and pinacidil, and 1 potassium channel blocker, glibenclamide, on cultured smooth muscle cells from Brown Norway rat aorta. All tested potassium channel openers increased mRNAs encoding proteins and enzymes involved in elastic fiber formation, whereas glibenclamide had the opposite effect. The higher steady-state level of tropoelastin mRNA in minoxidil-treated cells was attributable to an increase in both transcription and mRNA stability. Treatment of Brown Norway rats for 10 weeks with minoxidil or diazoxide increased elastic fiber content and decreased cell number in the aortic media, without changing collagen content. The minoxidil-induced cardiac hypertrophy was reduced when animals simultaneously received irbesartan, an angiotensin II-receptor antagonist. This side effect of minoxidil was not observed in diazoxide-treated animals. In conclusion, diazoxide, causing less undesirable side effects than minoxidil, or coadministration of minoxidil and irbesartan, increases elastic fiber content, decreases cell number in the aorta and, thus, could be suitable for treating vascular pathologies characterized by diminished arterial elastin content and simultaneous hypertension.

A review of the effectiveness of antimitotic drug injections for hypertrophic scars and keloids

Hypertrophic scars and keloids are common problems after injury and cause functional and cosmetic deformities. A wide variety of treatments have been advocated for hypertrophic scars and keloids regression. Unfortunately, the reported efficacy has been variable. This article explores antimitotic drugs described in the literature such as steroid injection, 5-FU, mitomycin C, and bleomycin, which mainly target the fibroblasts in scar tissue, have been proposed as the effective modalities for scar treatment and scar prevention after surgery, but restricted due to possible side effects. The current accepted treatment for hypertrophic scar and keloid are combination therapy and the early treatment which could achieve better efficacy and less adverse effect.

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.

Treatment of keloids and hypertrophic scars with dermojet injections of bleomycin: a preliminary study

BACKGROUND

Numerous treatment modalities have been used to treat keloids and hypertrophic scars, but the optimal treatment has not been established.

OBJECTIVE

The aim of this study was to determine the efficacy and safety of intralesional jet injection of bleomycin as therapy for keloids and hypertrophic scars that are unresponsive to intralesional steroid injection.

METHODS

The study included 14 patients with 15 keloids or hypertrophic scars that had not responded to a minimum of three intralesional injections of triamcinolone acetonide. Multiple jet injections of 0.1 ml of bleomycin (1.5 IU/ml) were administered to each lesion, with injection sites spaced 0.5 mm apart. Injections were repeated each month. Scar height was measured, and scar pliability and erythema were scored at baseline and then monthly during the treatment and follow-up periods. Patients' self-assessments of subjective symptoms (pruritus and pain) were also scored. Clinical improvement was defined primarily on the basis of scar height reduction (percentage reduction from baseline), and was classified using the following scale: complete flattening (100%), highly significant flattening (> 90%), significant flattening (75-90%), moderate flattening (50-75%), and minimal flattening (< 50%). Pre- and post-treatment mean values for scar height, scar pliability, erythema, pruritus and pain were statistically compared.

RESULTS

The number of sessions required to successfully treat the lesions ranged from two to six. Eleven lesions (73.3%) showed complete flattening, one (6.7%) showed highly significant flattening, two (13.3%) showed significant flattening, and one scar (6.7%) showed moderate flattening. The mean scar height was significantly lower, and the mean scores for scar pliability and erythema were significantly better at the end of treatment (P < 0.001, P < 0.001 and P < 0.001, respectively). The mean scores for pruritus and pain also improved significantly (P < 0.001 and P = 0.01, respectively). The observed side-effects were hyperpigmentation (four lesions) and skin atrophy (three lesions). No recurrences were noted during follow up (mean duration of 19 months).

CONCLUSIONS

Intralesional jet injection of bleomycin is an effective and safe method of treating keloids and hypertrophic scars that are unresponsive to intralesional steroid therapy.

Lysyl oxidase deficiency: a new cause of human arterial dissection

Spontaneous coronary artery dissection is a rare cause of myocardial ischaemia. The underlying mechanism is unknown but some dissections are associated with extracellular matrix disorganisation of genetic origin. A deficiency in extracellular matrix protein cross links has rarely been studied. A single clinical case of spontaneous coronary artery dissection is reported. Lysyl oxidase (LOX) and extracellular matrix organisation were investigated by skin immunohistology and polymerase chain reaction of LOX expression. Both approaches found a dramatic LOX decrease. LOX deficiency has a major role in human arterial wall organisation during development. The suspected mechanism is an elastin or collagen polymer cross linking deficiency.

D-penicillamine treatment for lipoid proteinosis

Lipoid proteinosis, a rare disorder inherited in an autosomal recessive fashion, is characterized by the deposition of hyaline-like material in the skin, mucous membranes, and other tissues. Perturbation of collagen metabolism has been suggested to play an important role in the pathogenesis. No effective therapy is available for the disease. The chelating agent D-penicillamine has long been used to treat several diseases. In addition to its immunosuppressive and anti-inflammatory effects, it also impairs fibroblast proliferation and inhibits the formation of the cross-links in collagen and elastin fibers. A 13-year-old girl was clinically and histologically diagnosed with lipoid proteinosis. We treated her with 600 mg/day of D-penicillamine for 2 years. The patient had improved clinically and histopathologically by the end of this treatment. We suggest D-penicillamine as a promising agent, even in low doses, for the treatment of lipoid proteinosis.

Lysyl oxidases: a novel multifunctional amine oxidase family

Lysyl oxidase (LOX), a copper-containing amine oxidase, belongs to a heterogeneous family of enzymes that oxidize primary amine substrates to reactive aldehydes. LOX has been traditionally known for one function, the extracellular catalysis of lysine-derived cross-links in fibrillar collagens and elastin. More recently, diverse roles have been attributed to lysyl oxidase and these novel activities cover a spectrum of diverse biological functions such as developmental regulation, tumor suppression, cell motility, and cellular senescence. Lysyl oxidase has also been shown to have both intracellular and intranuclear locations. The multifunctional properties of lysyl oxidase (LOX) and our recent discovery of three novel members of this amine oxidase family, LOX-like (LOXL), LOXL2, and LOXL3, indicate the possibility that these varied functions are performed in both intracellular and extracellular environments by individual novel members of the LOX amine-oxidase family. Structural similarities of the highly conserved copper-binding and lysyl-tyrosylquinone cofactor sites among the LOX and LOX-like proteins may result in similar amine oxidase activities. However, specific novel functions, such as a potential role in cell adhesion and cell growth control, will be determined by other, conserved domains such as the cytokine receptor-like domain that is shared by all LOXs and by multiple scavenger receptor cysteine-rich (SRCR) domains present in LOXL2 and LOXL3. Furthermore, these functions may be carried out in a temporally and spatially regulated fashion.

Minoxidil inhibits proliferation and migration of cultured vascular smooth muscle cells and neointimal formation after balloon catheter injury

The goal of the study was to investigate the in vitro and in vivo inhibition of minoxidil on smooth muscle cell (SMC) proliferation and migration as well as neointimal formation. The in vitro effect of minoxidil was investigated by Boyden chamber assay and cell-cycle analysis. To evaluate the in vivo effect, we treated the animals with minoxidil in their drinking water before and after balloon catheter injury to carotid artery. Results showed that minoxidil inhibited SMC migration across type I collagen membrane in a dose-related manner (13.5% by 0.01 mg/ml; p < 0.05; 16.8% by 0.05 mg/ml: p < 0.01; 40.4% by 0.25 mg/ml; p < 0.001; and 65.8% by 1.25 mg/ml; p < 0.001). Minoxidil (0.8 mg/ml) increased the number of SMCs in G1 phase (p < 0.05) and decreased the number of SMCs in S phase (p < 0.001). In vivo minoxidil treatment reduced neointimal mass by 31.7% (120 mg/L) and 42.3% (200 mg/L), respectively. Data demonstrate that minoxidil inhibits vascular SMC proliferation and migration both in vitro and in vivo, and therefore may be useful to inhibit SMC hyperplasia that occurs in restenosis and other vascular diseases.

Lysyl oxidase: properties, regulation and multiple functions in biology

Lysyl oxidase (LO) is a copper-dependent amine oxidase that plays a critical role in the biogenesis of connective tissue matrices by crosslinking the extracellular matrix proteins, collagen and elastin. Levels of LO increase in many fibrotic diseases, while expression of the enzyme is decreased in certain diseases involving impaired copper metabolism. While the three-dimensional structure of the enzyme is not yet available, many of its physical-chemical properties, its novel carbonyl cofactor, and its catalytic mechanism have been described. Lysyl oxidase is synthesized as a preproprotein, secreted as a 50 kDa, N-glycosylated proenzyme and then proteolytically cleaved to the 32 kDa, catalytically active, mature enzyme. Within the past decade, the gene encoding LO has been cloned, facilitating investigations of the regulation of expression of the enzyme in response to diverse stimuli and in numerous disease states. Transforming growth factor-beta, platelet-derived growth factor, angiotensin II, retinoic acid, fibroblast growth factor, altered serum conditions, and shear stress are among the effectors or conditions that regulate LO expression. New, LO-like genes have also been identified and cloned, suggesting the existence of a multigene family. It has also become increasingly evident that LO may have other important biological functions in addition to its role in the crosslinking of elastin and collagen in the extracellular matrix.

Impact of antifibrotic treatment of the course of Schistosoma mansoni infection in murine model

Administration of an antifibrotic agent as an adjunct to antihelmintic treatment with the objective of morbidity reduction was investigated in the murine schistosomiasis mansoni model. Antifibrotic, beta-aminopropionitrile treatment has a profound effect on the cellular matrix composition of the liver granuloma of Schistosoma mansoni infected mice when given alone, resulting in increase macrophage infiltration. These macrophages, in response to stimulation with soluble egg antigen or lipopolysaccharide produced elevated levels of nitric oxide but low levels of tumor necrosis factor alpha compared to untreated infected mice. This also correlated with reduced liver granuloma size. In spite of low numbers of eggs in the liver, mice receiving a combine treatment had a high level of resistance to a challenge infection compared with mice receiving only praziquantel. Those mice also exhibited a reduced lymphocyte proliferative response, similar to that of infected untreated mice. Antifibrotic treatment has an impact on the dynamic of the cellular nature of granulomas and impacts on the host immunity of infection.

Penicillamine-induced degenerative dermatoses: report of a case and brief review of such dermatoses

We describe a case of elastosis perforans serpiginosa with additional findings of degenerative skin changes. A 20-year-old man with hepatolenticular degeneration, under prolonged treatment with D-penicillamine, presented with a circular or serpiginous arrangement of nuchal papules. Histopathologically, transepidermal channels were accompanied by granulomatous reactions, with several giant cells engulfing elastic fibers. In addition to these findings of a typical elastosis perforans serpiginosa, we observed scar-like skin changes inside the circular arrangement of the papules. At the scar-like tissue, we found electron-microscopical evidence of randomly aggregated thin collagen fibers with no tendency toward systemic combined bundle formation, which is a characteristic feature of normal collagen fiber formation. Pseudoxanthoma-elasticum-like changes were observed on his neck. On his axillae and groin, slight skin thickening and wrinkling were detected. The diagnosis of elastosis perforans serpiginosa does not represent all of the manifestations or the pathological background described above. The skin manifestations described here represent not only an elastosis but also a total degenerative dermatosis with overhealed collagenosis. Thus, those dermatoses should be summarized as one entity, penicillamine-induced degenerative dermatosis. After considering the pathogenic background and clinical similarities, we further propose to simplify the penicillamine-induced skin manifestations to three categories: acute sensitivity reactions, bullous dermatoses, and degenerative dermatoses.

Induction of ovalbumin mRNA by ascorbic acid in primary cultures of tubular gland cells of the chicken oviduct

The present study was conducted to investigate the effects of aging and medium supplements on steroid-induced ovalbumin mRNA in primary cultures of tubular gland cells from the chicken oviduct. In experiment 1, the effect of aging was examined by comparing the responsiveness to administration of estrogen and corticosterone in cells derived from laying hens and estrogen-primed chicks. In experiment 2, the effect of supplementing a culture medium with various compounds on the responsiveness to the steroid treatment was examined. In experiment 3, the effect of supplementing with ascorbic acid was tested in the presence or absence of the steroid hormones. The results indicated that the oviduct cells from immature chicks had clearer induction of ovalbumin mRNA by the steroid treatment than did those from laying hens. Among medium supplements, ascorbate increased the steroid responsiveness to a great extent, and fetal calf serum had modest, but long lasting, induction of ovalbumin mRNA. The drastic induction of ovalbumin mRNA by ascorbic acid supplementation was exerted only when the steroid hormones were present in the medium, implying that the effect of ascorbic acid may be auxiliary in steroid-induced transcription of the ovalbumin gene.

Effects of ascorbic acid on proliferation and collagen synthesis in relation to the donor age of human dermal fibroblasts

Several events are associated with cellular aging: alterations in the extracellular matrix, loss of the cell's proliferative capacity, and decreased responsiveness to growth factors. In skin, a major component of the extracellular matrix is collagen; an important regulator of collagen synthesis is ascorbic acid, which may also have growth factor-like properties. To investigate the relationship of the extracellular matrix and proliferative capacity to aging, we examined the effects of ascorbic acid on cell proliferation and collagen expression in dermal fibroblasts from donors of two age classes, newborn (3-8 d old) and elderly (78-93 years old). In the absence of ascorbic acid (control) proliferative capacities were inversely related to age; newborn cell lines proliferated faster and reached greater densities than elderly cell lines. However, in the presence of ascorbic acid both newborn and elderly cells proliferated at a faster rate and reached higher densities than controls. To determine whether there are age-related differences in extracellular matrix production and ascorbic acid responsiveness we examined and found that collagen biosynthesis (collagenase-digestible protein) was inversely related to age, but the stimulation by ascorbic acid appeared age independent. The increase in collagen synthesis was reflected by coordinate increases in steady-state pro alpha 1(I) and pro alpha 1(III) collagen mRNAs, suggesting a pretranslational mechanism. Ascorbic acid appears capable of overcoming the reduced proliferative capacity of elderly dermal fibroblasts, as well as increasing collagen synthesis in elderly cells by similar degrees as in newborn cells even though basal levels of collagen synthesis are age dependent.