Skin Collagen Content Research Articles

Topical application of Gallic acid suppresses the 7,12-DMBA/Croton oil induced two-step skin carcinogenesis by modulating anti-oxidants and MMP-2/MMP-9 in Swiss albino mice

Gallic acid (GA – 3,4,5-trihydroxybenzoic acid), a dietary anti-oxidant has been shown to inhibit cancer cell growth in in vitro. Herein, we investigated the in vivo chemo preventive activity of GA on 7,12-Dimethylbenz[a]anthracene (DMBA)/Croton oil induced two-step skin carcinogenesis in Swiss albino mice. Skin tumor incidence and tumor volume were recorded during the 16weeks of experimental period. In addition, LDH-isozyme shift, skin collagen content, activities of matrix metalloproteinases (MMP-2/MMP-9) enzymes and enzymatic and non-enzymatic antioxidant were studied in the skin and serum of experimental mice. Tumor incidence was significantly increased in the DMBA/Croton oil induced mice (100%; p<0.001) when compared to GA co-treated mice (60%; p<0.01) and 5-FU treated mice (50%; p<0.01). Skin collagen content, MMPs activities, LDH-isoenzymes and MMP-2/-9 expressions were increased in DMBA/Croton oil induced skin while decreased levels of enzymatic (GST, SOD, CAT & GPx) and non-enzymatic anti-oxidant (GSH) were noticed. On the other hand, GA co-treatment exhibited a significant protection by reverting back the altered levels of LDH-isoenzymes, antioxidants, collagen and MMP-2/MMP-9 activities. The results of this study indicate that topical application of GA inhibits DMBA/Croton oil induced two-stage skin carcinogenic process by modulating the antioxidants and MMPs (-2 & -9) in the mouse skin.

In Vivo Antioxidant and Anti-Skin-Aging Activities of Ethyl Acetate Extraction from Idesia polycarpa Defatted Fruit Residue in Aging Mice Induced by D-Galactose.

Two different concentrations of D-galactose (D-gal) induced organism and skin aging in Kunming mice were used to examine comprehensively the antioxidant and antiaging activities of ethyl acetate extraction (EAE) from Idesia polycarpa defatted fruit residue for the first time. The oxygen radical absorbance capacity (ORAC) of EAE was 13.09 ± 0.11 μmol Trolox equivalents (TE)/mg, which showed EAE had great in vitro free radical scavenging and antioxidant activity. Biochemical indexes and morphological analysis of all tested tissues showed that EAE could effectively improve the total antioxidant capacity (T-AOC) of the antioxidant defense system of the aging mice, enhance the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) of tissues and serum, increase glutathione (GSH) content and decrease the malondialdehyde (MDA) content, and maintain the skin collagen, elastin, and moisture content. Meanwhile, EAE could effectively attenuate the morphological damage in brain, liver, kidney, and skin induced by D-gal and its effect was not less than that of the well-known L-ascorbic acid (VC) and α-tocopherol (VE). Overall, EAE is a potent natural antiaging agent with great antioxidant activity, which can be developed as a new medicine and cosmetic for the treatment of age-related conditions.

Optical coherence tomography (OCT) of collagen in normal skin and skin fibrosis

Optical coherence tomography (OCT) is a non-invasive imaging modality that is transforming clinical diagnosis in dermatology and other medical fields. OCT provides a cross-sectional evaluation of the epidermis and dermis and allows in vivo imaging of skin collagen. Upregulated collagen content is a key feature of fibrotic skin diseases. These diseases are often managed by the practitioner's subjective assessment of disease severity and response to therapies. The purpose of this review is to provide an overview of the principles of OCT and present available evidence on the ability of OCT to image skin collagen in vivo for the diagnosis and management of diseases characterized by skin fibrosis. We review OCT studies that characterize the collagen content in normal skin and fibrotic skin diseases including systemic sclerosis and hypertrophic scars secondary to burn, trauma, and other injury. We also highlight several limitations of OCT and suggest enhancements to improve OCT imaging of skin fibrosis. We conclude that OCT imaging has the potential to serve as an objective, non-invasive measure of collagen's status and disease progression for use in both research trials and clinical practice. The future use of OCT imaging as a quantitative imaging biomarker of fibrosis will help identify fibrosis and facilitate clinical examination in monitoring response to treatment longitudinally without relying on serial biopsies. The use of OCT technology for quantification of fibrosis is in the formative stages and we foresee tremendous growth potential, similar to the ultrasound development paradigm that evolved over the past 30 years.

OP0228 Protective Effect of LPA1 and 3 Receptor Antagonism in Experimental Skin Fibrosis is Linked to LPA Activity in Dermal Fibroblasts of SSC Patients

BackgroundLysophosphatidic acid (LPA) is a phospholipid generated by phospholipase D-mediated cleavage of phosphatidylcholine, mainly in adipocytes, fibroblasts or activated platelets. Knock down studies of the LPA1 receptor in lung and...

The natural organosulfur compound dipropyltetrasulfide prevents HOCl-induced systemic sclerosis in the mouse

IntroductionThe aim of this study was to test the naturally occurring organosulfur compound dipropyltetrasulfide (DPTTS), found in plants, which has antibiotic and anticancer properties, as a treatment for HOCl-induced systemic sclerosis in the mouse.MethodsThe prooxidative, antiproliferative, and cytotoxic effects of DPTTS were evaluated ex vivo on fibroblasts from normal and HOCl mice. In vivo, the antifibrotic and immunomodulating properties of DPTTS were evaluated in the skin and lungs of HOCl mice.ResultsH2O2 production was higher in fibroblasts derived from HOCl mice than in normal fibroblasts (P < 0.05). DPTTS did not increase H2O2 production in normal fibroblasts, but DPTTS dose-dependently increased H2O2 production in HOCl fibroblasts (P < 0.001 with 40 μM DPTTS). Because H2O2 reached a lethal threshold in cells from HOCl mice, the antiproliferative, cytotoxic, and proapoptotic effects of DPTTS were significantly higher in HOCl fibroblasts than for normal fibroblasts. In vivo, DPTTS decreased dermal thickness (P < 0.001), collagen content in skin (P < 0.01) and lungs (P < 0.05), αSMA (P < 0.01) and pSMAD2/3 (P < 0.01) expression in skin, formation of advanced oxidation protein products and anti-DNA topoisomerase-1 antibodies in serum (P < 0.05) versus untreated HOCl mice. Moreover, in HOCl mice, DPTTS reduced splenic B-cell counts (P < 0.01), the proliferative rates of B-splenocytes stimulated by lipopolysaccharide (P < 0.05), and T-splenocytes stimulated by anti-CD3/CD28 mAb (P < 0.001). Ex vivo, it also reduced the production of IL-4 and IL-13 by activated T cells (P < 0.05 in both cases).ConclusionsThe natural organosulfur compound DPTTS prevents skin and lung fibrosis in the mouse through the selective killing of diseased fibroblasts and its immunomodulating properties. DPTTS may be a potential treatment for systemic sclerosis.

Collagen Content in Skin and Internal Organs of the Tight Skin Mouse: An Animal Model of Scleroderma

The Tight Skin mouse is a genetically induced animal model of tissue fibrosis caused by a large in-frame mutation in the gene encoding fibrillin-1 (Fbn-1). We examined the influence of gender on the collagen content of tissues in C57BL/6J wild type (+/+) and mutant Tight Skin (Tsk/+) mice employing hydroxyproline assays. Tissue sections were stained with Masson's trichrome to identify collagen in situ. Adult Tsk/+ mice skin contains ~15% more collagen, on average, than skin from +/+ mice of the same gender. The heart of Tsk/+ males had significantly more collagen than that of +/+ males. No significant gender differences were found in lungs and kidney collagen content. Overall, the collagen content of Tsk/+ males and +/+ males was higher than that of their Tsk/+ and +/+ female counterparts, respectively. Our data confirm increased deposition of collagen in skin and hearts of Tsk/+ mice; however, the effects of the Tsk mutation on collagen content are both tissue specific and gender specific. These results indicate that comparative studies of collagen content between normal and Tsk/+ mice skin and internal organs must take into account gender differences caused by expression of the androgen receptor.

Reactive oxygen species–mediated killing of activated fibroblasts by arsenic trioxide ameliorates fibrosis in a murine model of systemic sclerosis

In patients with systemic sclerosis (SSc), activated fibroblasts produce reactive oxygen species (ROS) that stimulate their proliferation and collagen synthesis. By analogy with tumor cells that undergo apoptosis upon cytotoxic treatment that increases ROS levels beyond a lethal threshold, we tested whether activated fibroblasts could be selectively killed by the cytotoxic molecule arsenic trioxide (As(2) O(3) ) in a murine model of SSc. SSc was induced in BALB/c mice by daily intradermal injections of HOCl. Mice were simultaneously treated with daily intraperitoneal injections of As(2) O(3) . As(2) O(3) limited dermal thickness and inhibited collagen deposition, as assessed by histologic examination and measurement of mouse skin and lung collagen contents. As(2) O(3) abrogated vascular damage, as shown by serum vascular cell adhesion molecule 1 level, and inhibited the production of autoantibodies, interleukin-4 (IL-4), and IL-13 by activated T cells. These beneficial effects were mediated through ROS generation that selectively killed activated fibroblasts containing low levels of glutathione. Our findings indicate that treatment with As(2) O(3) dramatically improves skin and lung fibrosis in a mouse model of SSc, providing a rationale for the evaluation of As(2) O(3) treatment in patients with SSc.

17β‐estradiol protects human skin fibroblasts and keratinocytes against oxidative damage

Reactive oxygen species (ROS) cause severe damage to extracellular matrix and to molecular structure of DNA, proteins and lipids. Accumulation of these molecular changes apparently constitutes the basis of cell ageing. 17b-estradiol (E2) has a key role in skin ageing homeostasis as evidenced by the accelerated decline in skin appearance seen in the perimenopausal years. Oestrogens improve many aspects of the skin such as skin thickness, vascularization, collagen content and quality. Despite these clinical evidences, the effects of oestrogens on skin at the cellular level need further clarification. HaCaT and human fibroblasts were cultured under various conditions with E2 and H2 O2 ; then were subjected to immunofluorescence and western blot analysis. Lipoperoxidation was investigated using BODIPY. In human fibroblasts oxidative stress decreases procollagen-I synthesis, while E2 significantly increases it. Fibroblasts and HaCaT cells viability in the presence of E2 demonstrates a notably increased resistance to H2 O2 effects. Furthermore E2 is able to counteract H2 O2 -mediated lipoperoxidation and DNA oxidative damage in skin cells. In this study we highlight that the menopause-associated oestrogens decline is involved in reduced collagen production and that E2 could counteract the detrimental effects of oxidative stress on the dermal compartment during skin aging. Furthermore, our data show that physiological concentrations of oestrogens are able to interfere with ROS-mediated cell viability reduction and to protect human skin cells against oxidative damage to cellular membranes and nucleic acids structure. Our experimental data show that the presence of 17β-estradiol may protect skin cells against oxidative damage and that the dramatic lowering of oestrogen levels during menopause, could render skin more susceptible to oxidative damage.

Profil Kadar Kolagen Kulit dan Tulang Tikus Wistar pada Berbagai Umur yang Mendapat Perlakuan Stres Oksidatif Hiperkolesterolemia dan Oleoresin Kulit Batang Kayu Manis (Cinnamomum sp)

Oleoresin cinnamon bark belonging to the phenolic compounds that are known to have potential as antioxidants. On the basis of the potential of these compounds may be used to prevent or repair tissue damage, whether caused by the factors of age and condition of oxidative stress hypercholesterolemia. This study aimed to obtain skin and bone collagen profile of Wistar rats at various ages after oxidative stress treated hypercholesterolemia and oleoresin from the bark of cinnamon (Cinnamomum sp). This study used 54 male Wistar rats with body weight (200 ± 5 g), which are grouped into six treatment groups combined with the three age groups of mice that is three, six or nine months with three replications. Each group received treatment oleoresin and hypercholesterolemia. Giving oral oleoresin conducted on rats given oral way during the 7 days with a dose of 12 rats mg/200-gr bw / day. Hypercholesterolemic rats was conducted by feeding cholesterol content within 1% during the two months. The results showed that the profile of skin and bone collagen content of the highest found on threemonth old rats treated with oleoresin, oleoresin hypercholesterolemia and given again (P6, 2), namely 57.44 tg / mg and 33.47 tg / mg, while the profile of skin and bone collagen content of the lowest found in rats aged 9 months to get treatment without treatment of hypercholesterolemia oleoresin (P2, 9), namely 28.26 tg / mg and 10.65 tg / mg. From this research can be concluded that the condition of hypercholesterolemia and duration of the aging effect on skin collagen levels decrease and bone, and vice versa oleoresin at the age of young rats that received the treatment of oxidative stress could repair or prevent hypercholesterolemia decreased content of skin collagen and bone. In general, the rats are treated oleoresin and young age profile of the collagen content of skin and bones better compared with rats that do not get treatment in conditions of oxidative stress oleoresin hypercholesterolemia.

Effect of dietary zinc proteinate supplementation on growth performance, and skin and meat quality of male and female broiler chicks

1. An experiment was conducted to evaluate the effect of dietary zinc proteinate (ZP) supplementation on growth performance and on skin and meat quality of male and female broiler chicks. 2. A total of 240 1-d-old male and 240 1-d-old female broiler chicks were randomly distributed into 24 floor pens (12 replicate pens/sex; 20 birds/pen) and were given either 0 (Control diet) or 40 mg/kg ZP (ZP 40), resulting in a 2 × 2 factorial arrangement of treatments. 3. The growth performance of male and female broiler chicks was not affected by the ZP supplementation, but the males showed significantly higher growth performance than did females. 4. ZP supplementation increased the total thickness of skin in both sexes, and males had thicker skin than females. It also increased the collagen content of skin, but not that of meat. Males had higher skin collagen contents than did females, but no sex difference was found in the meat collagen contents. 5. ZP supplementation did not affect the shear force values of skin and meat; however, males had higher shear force values of back skin than females. ZP supplementation increased the zinc contents of thigh meat and plasma in both sexes. Males had higher zinc contents in back skin than females. 6. It is concluded that dietary ZP supplementation could increase the skin quality of broiler chicks in both sexes, particularly in female broilers, without any effect on growth performance. Male broilers have better growth performance and skin quality than females.

Increasing Effect of an Oral Intake of &lt;small&gt;L&lt;/small&gt;-Hydroxyproline on the Soluble Collagen Content of Skin and Collagen Fragments in Rat Serum

We examined the effects of oral L-hydroxyproline (Hyp) on collagen in the body. After 2 weeks' administration of Hyp (0.5 or 1 g/kg) to F344 male rats, the soluble collagen content of the skin had increased, and the serum concentration of collagen peptides was correlated with the skin content of soluble collagen. This result suggests that oral Hyp augmented collagen metabolism.

Effect of Sex and Dietary Organic Zinc on Growth Performance, Carcass Traits, Tissue Mineral Content, and Blood Parameters of Broiler Chickens

Zinc (Zn) is an essential mineral for animal development and function. A study was carried out to evaluate the effect of sex and dietary organic zinc (OZ) on growth performance, carcass traits, tissue mineral content, and blood parameters of broiler chickens. A total of 240 1-day-old male and 240 female broiler chicks (Cobb × Cobb) were assigned to two dietary levels of OZ (2 × 2 factorial) with six replicates per treatment (20 birds/replicate pen). The OZ supplementation levels were 0 and 25 ppm. Results showed that OZ supplementation did not affect the growth performance of male and female broilers, but the males showed significantly better (P < 0.05) growth performance than females did. Similarly, OZ supplementation did not affect the thickness of both the back and thigh skin of male and female broilers; however, males had thicker skin than females. Dietary OZ supplementation did not affect collagen contents in the skin and meat samples. Male broilers had higher skin collagen contents than females, but no sex difference was found in meat collagen contents. OZ supplementation did not affect the shear force values of skin and meat samples. Male broilers had higher shear force values of back skin than females, but not in the meat samples. Dietary OZ supplementation increased (P < 0.05) the thigh meat Zn content in both sexes. The plasma Ca content was significantly (P < 0.05) increased by dietary OZ supplementation; however, other blood parameters were not affected by dietary OZ supplementation. Males had higher plasma glucose and cholesterol content than females. It is concluded that dietary OZ supplementation at the level of 25 ppm does not affect the growth performance and skin quality of broiler chickens but increases the Zn content in thigh meat and Ca content in plasma of broiler chickens. Male broilers had better growth performance and skin quality than females.

Supplementation of graded levels of organic zinc in the diets of female broilers: effects on performance and carcase quality

1. Zinc is an essential trace element. The objective of this research was to investigate the effects of various levels of organic zinc (OZ) supplementation on growth performance and carcase quality of female broiler chickens. 2. A total of 3200 1-d-old female broiler chicks were randomly allotted to 16 floor pens with 200 birds per pen. A maize-wheat-soyabean meal basal diet (Control) was formulated and 20 mg/kg OZ (20 OZ), 40 mg/kg OZ (40 OZ), and 80 mg/kg OZ (80 OZ) were added to the basal diet to form 4 dietary treatments with 4 replicates per treatment. The OZ source was zinc proteinate which contained 15% zinc. 3. Results showed no significant difference between the treatments in growth performance. A significant increase in thigh skin epidermis and dermis thickness was shown in the OZ supplementation groups; however, no effect was found on the thickness of back skin epidermis and dermis. 4. Collagen contents in breast and thigh meats were not influenced by OZ supplementation but a significant increase in collagen content was found in the back and thigh skin. This increase in collagen content was significantly greater in the back and thigh skin of OZ 80 than with OZ 20. 5. Shear force value and zinc concentration in skins and meat were not significantly influenced by supplementation with OZ. 6. It is concluded that dietary OZ does not improve growth performance of broilers; however, it could increase skin thickness by increasing collagen content in skin, thereby improving carcase quality.

S100A8/A9 in bleomycin-induced skin fibrosis

Background and objectivesSystemic sclerosis is a heterogeneous disease characterised both by inflammation and fibrosis. TLR4-dependent signalling has been proposed to play a significant role in the connection between inflammation and...

Effects of topical application of Calendula officinalis gel on collagen and hydroxyproline content of skin in rats

In this investigation, the effects of different concentrations of Calendula officinalis gel on collagen and hydroxyproline content of the skin are studied. Sixty-five mature male rats were randomly divided into three groups (control, placebo, and treatment group). Under sterile conditions, a 2 × 2-cm piece of cervical skin was excised in each animal. Treatment group received a daily topical application of 5%, 7%, and 10% C. officinalis gel, the placebo group received a daily topical application of the base gel, and the control group received no treatment during this experimental study. Fourteen, 21, and 45 days later, the rats were euthanized and biopsies were taken from the site of the initial incisions and samples were collected for biochemical investigation. Collagen production in the group treated with 7% gel was significantly more than the placebo and control group. Upper and lower doses seem to be less effective, although the reasons for this remain unclear.

Skin collagen reproduction increased by ascorbic acid derivative iontophoresis by frequent‐reversal bipolar electric stimulation

The effect of the iontophoresis of ascorbic acid (Vitamin C; VC) derivative with frequent-reversal bipolar electric stimulation on the production of collagen in rat skin was evaluated in terms of hydroxyproline content through high-performance liquid chromatography. First, a control group was not given electrical stimulation and four groups were stimulated with a unipolar pulse for 0.5-10 min every day for one week. The hydroxyproline level in the skin was increased depending on the length of the stimulation. Second, a control group was not given any electrical stimulation, and three groups were treated with (a) VC solution without any stimulation, (b) a bipolar pulse for 10 min with saline, or (c) a bipolar pulse for 5 min with the VC solution. Significant increases were found in all the stimulation groups, although these treated with the VC solution without any stimulation did not have any effects compared to the control. Thus, in order to increase the hydroxyproline levels in skin, a VC must be delivered with bipolar stimulation as a method of iontophoresis. These results suggest that our newly developed electric stimulation is effective at increasing skin collagen content, and that bipolar stimulation is more effective on the iontophoresis of not only VC but also some medicines such as low- and high-molecular drugs directed to the target organ (7).

Collagen and Elastic Content of Abdominal Skin After Surgical Weight Loss

Collapsed skin folds after bariatric weight loss are often managed by plastic procedures, but changes in dermal composition and architecture have rarely been documented. Given the potential consequences on surgical outcome, a prospective histochemical study was designed. The hypothesis was that a deranged dermal fiber pattern would accompany major changes in adipose tissue. Female surgical candidates undergoing postbariatric abdominoplasty (n=40) and never obese women submitted to control procedures (n=40) were submitted to double abdominal biopsy, respectively in the epigastrium and hypogastrium. Histomorphometric assessment of collagen and elastic fibers was executed by the Image Analyzer System (Kontron Electronic 300, Zeiss, Germany). Depletion of collagen, but not of elastic fibers, in cases with massive weight loss was confirmed. Changes were somewhat more severe in epigastrium (P=0.001) than hypogastrium (P=0.007). Correlation with age did not occur. (1) Patients displayed lax, soft skin lacking sufficient collagen fiber network. (2) Elastic fiber content was not damaged, and was even moderately increased in epigastrium; (3) Preoperative obesity negatively correlated with hypogastric collagen concentration; (4) Future studies should pinpoint the roles of obesity, and especially of massive weight loss, on dermal architecture and response to surgery.

Novel Anti-Fibrotic Therapies for Experimental Chronic Graft-Versus-Host Disease.

Abstract 4490 BackgroundChronic graft-versus host disease (cGvHD) can result in a scleroderma-like disease with dermal, pulmonary and gastrointestinal fibrosis. The histopathological hallmark of sclerodermatous chronic GvHD is accumulation of extracellular matrix proteins by pathologically activated fibroblasts, caused at least in part by the profibrotic cytokines TGF-β and PDGF. It was shown recently that the family of abl kinases plays an important role in the activation of matrix synthesis. Here we investigated whether imatinib and nilotinib, both targeting specifically TGF-β and PDGF signaling pathways by inhibiting the tyrosine kinase activity of c-abl and PDGF receptors, could reduce cGvHD in a murine model. Material and MethodsRecipient mice (BALB/c, H2d) received total body irradiation (2×6 Gy), followed by 1×10∧6 bone marrow cells and 2×10∧6 splenocytes from B10.D2 donors (H2d, multiple minor mismatches). Recipients receiving syngeneic bone marrow and spleen cells served as control. The treatment of transplanted mice started 12 to 14 days post transplantation. Imatinib (150 mg/kg) was given per os once daily and nilotinib (37.5 mg/kg) was administrated per os twice daily until 6 weeks after bone marrow transplantation. Observed skin changes were documented using a clinical score. After 6 weeks dermal thickness was determined by staining with hematoxylin and eosin and activated fibroblasts by using immunohistochemistry for alpha smooth muscle actin. Collagen concentration in afflicted skin was analyzed with the hydroxyproline assay. ResultsUntreated mice receiving an allogeneic transplant, in contrast to syngeneic controls, showed clinical features of cutaneous cGvHD, including skin lesions with alopecia and a lower mobility, in addition to diarrhea and weight loss until 6 weeks after alloBMT. Treatment of recipients with imatinib and nilotinib resulted in serum concentrations comparable to those achieved in humans by standard dosing. Application of imatinib or nilotinib completely prevented the development of cutaneous cGvHD including alopecia and skin ulceration, and was effective in preventing weight loss. Compared to untreated recipients dermal thickness was decreased by 100 ± 8 % (p = 0.001) with imatinib and by 54 ± 14 % (p = 0.016) with nilotinib. The numbers of myofibroblasts were reduced by 84 ± 16 % (p = 0.001) with imatinib and by 87 ± 18 % (p = 0.002) with nilotinib. Furthermore, the collagen content in afflicted skin was reduced by 83 ± 15 % with imatinib and by 94 ± 14 % with nilotinib. ConclusionsThe combined inhibition of c-abl and PDGFR by imatinib or nilotinib was effective for the prevention of sclerodermatous chronic GvHD. The data support recent clinical observations of the potential effect of imatinib in fibrotic chronic graft-versus-host disease. Disclosures:Spriewald:Novartis: Research Funding. Off Label Use: Imatinib and Nilotinib as anti-fibrotic drug in the prevention and treatment of chronic graft-versus-host disease.. Distler:Novartis: Research Funding.

Rosiglitazone Abrogates Bleomycin-Induced Scleroderma and Blocks Profibrotic Responses Through Peroxisome Proliferator-Activated Receptor-γ

The nuclear hormone receptor, peroxisome proliferator-activated receptor (PPAR)-gamma, originally identified as a key mediator of adipogenesis, is expressed widely and implicated in diverse biological responses. Both natural and synthetic agonists of PPAR-gamma abrogated the stimulation of collagen synthesis and myofibroblast differentiation induced by transforming growth factor (TGF)-beta in vitro. To characterize the role of PPAR-gamma in the fibrotic process in vivo, the synthetic agonist rosiglitazone was used in a mouse model of scleroderma. Rosiglitazone attenuated bleomycin-induced skin inflammation and dermal fibrosis as well as subcutaneous lipoatrophy and counteracted the up-regulation of collagen gene expression and myofibroblast accumulation in the lesioned skin. Rosiglitazone treatment reduced the induction of the early-immediate transcription factor Egr-1 in situ without also blocking the activation of Smad2/3. In both explanted fibroblasts and skin organ cultures, rosiglitazone prevented the stimulation of collagen gene transcription and cell migration elicited by TGF-beta. Rosiglitazone-driven adipogenic differentiation of both fibroblasts and preadipocytes was abrogated in the presence of TGF-beta; this effect was accompanied by the concomitant down-regulation of cellular PPAR-gamma mRNA expression. Collectively, these results indicate that rosiglitazone treatment attenuates inflammation, dermal fibrosis, and subcutaneous lipoatrophy via PPAR-gamma in a mouse model of scleroderma and suggest that pharmacological PPAR-gamma ligands, widely used as insulin sensitizers in the treatment of type-2 diabetes mellitus, may be potential therapies for scleroderma.

α‐melanocyte–stimulating hormone suppresses bleomycin‐induced collagen synthesis and reduces tissue fibrosis in a mouse model of scleroderma: Melanocortin peptides as a novel treatment strategy for scleroderma?

Recently, we found that human dermal fibroblasts (HDFs) express melanocortin 1 receptors (MC-1R) that bind alpha-melanocyte-stimulating hormone (alpha-MSH). In search of novel therapies for scleroderma (systemic sclerosis [SSc]), we used the bleomycin (BLM) model to investigate the effects of alpha-MSH on collagen synthesis and fibrosis. Collagen expression in HDFs was determined by real-time reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analyses. Signal transduction studies included pharmacologic blockade, immunofluorescence analysis, Western blotting, and reporter-promoter assays. Oxidative stress was measured by fluorescence-activated cell sorter analysis, and anti-oxidative enzyme levels were determined by real-time RT-PCR and Western blot analyses. The effect of alpha-MSH in the BLM mouse model of scleroderma was assessed by histologic, immunohistochemical, real-time RT-PCR, and protein analyses. Expression of MC-1R and pro-opiomelanocortin (POMC) in skin and HDF samples from patients with SSc was determined by RT-PCR and compared with that in samples from normal controls. Treatment with alpha-MSH (and related peptides) suppressed BLM-induced expression of type I and type III collagen in HDFs, and this effect was cAMP-dependent. Neither BLM nor alpha-MSH altered Smad signaling, but antioxidants inhibited BLM-induced collagen expression in vitro. In addition, alpha-MSH suppressed BLM-induced oxidative stress and enhanced the expression of superoxide dismutase 2 (SOD2) and heme oxygenase 1 (HO-1). In the BLM mouse model, alpha-MSH reduced skin fibrosis and collagen content and increased tissue levels of SOD2 and HO-1. In skin and HDFs from patients with SSc, both MC-1R and POMC messenger RNAs were detected, but there were no differences compared with healthy controls. Alpha-melanocyte-stimulating hormone and related peptides that exert their effects via MC-1R may provide a novel antifibrogenic therapeutic tool for the treatment of fibrotic diseases such as scleroderma.