Epidermal growth factor affects the synthesis and degradation of type I collagen in cultured human dermal fibroblasts

Mesenteric Adipose Tissue Contributes to Intestinal Fibrosis in Crohn's Disease Through the ATX-LPA Axis

BACKGROUND AND AIMS

Intestinal fibrostenosis is an important cause of surgical intervention in patients with Crohn's disease [CD]. Hypertrophic mesenteric adipose tissue [MAT] is associated with the disease process of CD. The purpose of this study was to investigate the contribution of MAT to intestinal fibrosis.

METHODS

MAT from surgical specimens of fibrostenotic CD patients and controls was collected for measurement of the levels of autotaxin [ATX] and lysophosphatidic acid [LPA]. ATX was inhibited in vivo in DNBS [dinitrobenzene sulfonic acid]-induced colitis mice, which were evaluated for colonic inflammation and fibrosis. 3T3-L1 cells and primary colonic fibroblasts were used in vitro to investigate the interaction between MAT and intestinal fibrosis, as well as the molecular mechanism underlying this interaction.

RESULTS

MAT adjacent to the fibrostenotic intestine in CD patients showed an activated ATX-LPA axis. An in vivo study indicated that inhibition of ATX was associated with the improvement of morphology and function of diseased MAT, which was combined with ameliorated intestinal inflammation and fibrosis in DNBS-instilled mice. In vitro studies showed that hypoxia stimulated adipocyte ATX expression and that LPA stabilized adipocyte HIF-1α protein, forming an ATX-LPA-HIF-1α amplification loop and aggravating adipocyte dysfunction. LPA secreted by adipocytes bound to LPA1 on the surface of fibroblasts, promoted their proliferation and differentiation, and increased the expression of fibrosis-related factors.

CONCLUSIONS

The ATX-LPA axis regulated intestinal fibrosis by influencing the proliferation and differentiation of intestinal fibroblasts. Inhibiting this axis may be a therapeutic target for intestinal fibrosis in CD.

Proteome-Wide Analysis Using SOMAscan Identifies and Validates Epidermal Growth Factor as a Disease Marker of Collagenous Gastritis

Background and Aims

Collagenous gastritis (CG) is a rare disorder characterized by increased subepithelial collagen deposition and inflammatory infiltrates. The mechanisms involved in CG pathogenesis are poorly understood, and no CG-associated biomarkers have been identified. This proteomics study identified serum biomarkers and pathogenic pathways to provide new knowledge about the pathobiology of CG, a disease reported in less than 100 patients.

Methods

Nine serum samples from pediatric patients diagnosed with CG were evaluated using novel aptamer-based proteomic technology and systems biology to generate new knowledge about the complex interactions between the differentially expressed proteins and candidate upstream regulators, using the Ingenuity Pathway Analysis in patients with non-CG and patients with normal gastric biopsies or nongastritis (NG).

Results

SOMAscan analysis identified 63 proteins significantly dysregulated in CG as compared to non-CG or NG patients that converged around enhanced inflammatory response and immune cell migration but reduced vascular functions. Principal component analysis using 15 of those proteins accurately separated the CG cases from the 2 comparator control groups. Using immunoassays, serum epidermal growth factor concentrations in CG patients, a protein involved in collagen production, were confirmed to be significantly lower than those in gastritis/NG patients.

Conclusion

This is the first comprehensive analysis of the proteome in CG patients that reveals metabolic pathways relating inflammation and fibrosis as well as a new potential role of epidermal growth factor as a disease biomarker.

Ameliorating Fibrotic Phenotypes of Keloid Dermal Fibroblasts through an Epidermal Growth Factor-Mediated Extracellular Matrix Remodeling

Keloid and hypertrophic scars are skin fibrosis-associated disorders that exhibit an uncontrollable proliferation of fibroblasts and their subsequent contribution to the excessive accumulation of extracellular matrix (ECM) in the dermis. In this study, to elucidate the underlying mechanisms, we investigated the pivotal roles of epidermal growth factor (EGF) in modulating fibrotic phenotypes of keloid and hypertrophic dermal fibroblasts. Our initial findings revealed the molecular signatures of keloid dermal fibroblasts and showed the highest degree of skin fibrosis markers, ECM remodeling, anabolic collagen-cross-linking enzymes, such as lysyl oxidase (LOX) and four LOX-like family enzymes, migration ability, and cell–matrix traction force, at cell–matrix interfaces. Furthermore, we observed significant EGF-mediated downregulation of anabolic collagen-cross-linking enzymes, resulting in amelioration of fibrotic phenotypes and a decrease in cell motility measured according to the cell–matrix traction force. These findings offer insight into the important roles of EGF-mediated cell–matrix interactions at the cell–matrix interface, as well as ECM remodeling. Furthermore, the results suggest their contribution to the reduction of fibrotic phenotypes in keloid dermal fibroblasts, which could lead to the development of therapeutic modalities to prevent or reduce scar tissue formation.

Proline-dependent regulation of collagen metabolism

This review is focused on recent data on the role of proline (Pro) in collagen biosynthesis and cellular metabolism. It seems obvious that one of the main substrates for collagen biosynthesis Pro is required to form collagen molecule. The question raised in this review is whether the Pro for collagen biosynthesis is synthesized "de novo", comes directly from degraded proteins or it is converted from other amino acids. Recent data provided evidence that extracellular Pro (added to culture medium) had significant, but relatively little impact on collagen biosynthesis in fibroblasts (the main collagen synthesized cells) cultured in the presence of glutamine (Gln). However, extracellular Pro drastically increased collagen biosynthesis in the cells cultured in Gln-free medium. It suggests that Pro availability determines the rate of collagen biosynthesis and demand for Pro in fibroblasts is predominantly met by conversion from Gln. The potential mechanism of this process as well as possible implication of this knowledge in pharmacotherapy of connective tissue diseases is discussed in this review.

Shell extracts of the edible mussel and oyster induce an enhancement of the catabolic pathway of human skin fibroblasts, in vitro

Mollusc shells are composed of more than 95% calcium carbonate and less than 5% organic matrix consisting mostly of proteins, glycoproteins and polysaccharides. In this study, we investigated the effects of matrix macromolecular components extracted from the shells of two edible molluscs of economic interest, i.e., the blue mussel Mytilus edulis and the Pacific oyster Crassostrea gigas. The potential biological activities of these organic molecules were analysed on human dermal fibroblasts in primary culture. Our results demonstrate that shell extracts of the two studied molluscs modulate the metabolic activities of the cells. In addition, the extracts caused a decrease of type I collagen and a concomitant increase of active MMP-1, both at the mRNA and the protein levels. Therefore, our results suggest that shell extracts from M. edulis and C. gigas contain molecules that promote the catabolic pathway of human dermal fibroblasts. This work emphasises the potential use of these shell matrices in the context of anti-fibrotic strategies, particularly against scleroderma. More generally, it stresses the usefulness to valorise bivalve shells that are coproducts of shellfish farming activity.

Anti-Photoaging Effects of Angelica acutiloba Root Ethanol Extract in Human Dermal Fibroblasts

The effects that ultraviolet rays elicit on collagen synthesis and degradation are the most common causes of wrinkle formation and photo-aging in skin. The objectives of this study were to evaluate the effects of Angelica acutiloba root ethanol extract (AAEE) to promote collagen synthesis and inhibit collagen degradation in human dermal fibroblasts. By examining total polyphenol and flavonoid contents, electron donating ability, radical scavenging activity, and superoxide dismutase-like activity, we found that AAEE exhibited fairly good antioxidant activity. Treatment with AAEE significantly increased type I procollagen production by cultured fibroblasts, as well as reduced ultraviolet-induced matrix metalloproteinase-1 (MMP-1) expression and MMP-2 activity in a dose-dependent manner (p < 0.05). In addition, AAEE significantly increased TIMP-1 mRNA expression (p < 0.05), although without an associated dose-dependent increase in TIMP-1 protein expression. In summary, we suggest that AAEE may be a potentially effective agent for the prevention or alleviation of skin-wrinkle formation induced by ultraviolet rays.

Role of non-mulberry silk fibroin in deposition and regulation of extracellular matrix towards accelerated wound healing

Bombyx mori silk fibroin (BMSF) as biopolymer has been extensively explored in wound healing applications. However, limited study is available on the potential of silk fibroin (SF) from non-mulberry (Antheraea assama and Philosamia ricini) silk variety. Herein, we have developed non-mulberry SF (NMSF) based electrospun mats functionalized with epidermal growth factor (EGF) and ciprofloxacin HCl as potential wound dressing. The NMSF based mats exhibited essential properties of wound dressing like biocompatibility, high water retention capacity (440%), water vapor transmission rate (∼2330gm^-2day^-1), high elasticity (∼2.6MPa), sustained drug release and antibacterial activity. Functionalized NMSF mats enhanced the proliferation of human dermal fibroblasts and HaCaT cells in vitro as compared to non-functionalized mats (p⩽0.01) showing effective delivery of EGF. Extensive in vivo wound healing assesment demonstrated accelerated wound healing, enhanced re-epithelialization, highly vascularized granulation tissue and higher wound maturity as compared to BMSF based mats. NMSF mats treated wounds showed regulated deposition of mature elastin, collagen and reticulin fibers in the extracellular matrix of skin. Presence of skin appendages and isotropic collagen fibers in the regenerated skin also demonstrated scar-less healing and aesthetic wound repair.

STATEMENT OF SIGNIFICANCE

A facile fabrication of a ready-to-use bioactive wound dressing capable of concomitantly accelerating the healing process as well as deposition of the extracellular matrix (ECM) to circumvent further scarring complicacies has become a focal point of research. In this backdrop, our present work is based on non-mulberry silk fibroin (NMSF) electrospun antibiotic loaded semi-occlusive mats, mimicking the ECM of skin in terms of morphology, topology, microporous structure and mechanical stiffness. Regulation of ECM deposition and isotropic orientation evinced the potential of the mat as an instructive platform for skin regeneration. The unique peptide motifs of NMSF assisted the augmented recruitment of fibroblast, keratinocytes and endothelial cells leading to accelerated wound healing. Early progression of mature granulation, faster re-epithelialization and angiogenesis in the wounds in in vivo rabbit model forwarded the blended nanofibrous mats of NMSF and PVA ferrying EGF, apt for scarless healing.

Antiageing Mechanisms of a Standardized Supercritical CO 2 Preparation of Black Jack (Bidens pilosa L.) in Human Fibroblasts and Skin Fragments

The use of topical retinoids to treat skin disorders and ageing can induce local reactions, while oral retinoids are potent teratogens and produce several unwanted effects. This way, efforts to explore complementary care resources should be supported. Based on this, we evaluate the antiageing effects of a supercritical CO₂ extract from Bidens pilosa L. (BPE-CO₂A) containing a standardized multicomponent mixture of phytol, linolenic, palmitic, linoleic, and oleic acids. BPE-CO₂A was assessed for its effects on human dermal fibroblasts (TGF-β1 and FGF levels using ELISA; collagen, elastin, and glycosaminoglycan by colorimetric assays, and mRNA expression of RXR, RAR, and EGFr by qRT-PCR) and human skin fragments (RAR, RXR, collagen, elastin, and glycosaminoglycan by immunohistochemical analysis). Levels of extracellular matrix elements, TGF-β1 and FGF, and EGFr gene expression were significantly increased by BPE-CO₂A. The modulation of RXR and RAR was positively demonstrated after the treatment with BPE-CO₂A or phytol, a component of BPE-CO₂A. The effects produced by BPE-CO₂A were similar to or better than those produced by retinol and retinoic acid. The ability to stimulate extracellular matrix elements, increase growth factors, and modulate retinoid and rexinoid receptors provides a basis for the development of preparation containing BPE-CO₂A as an antiageing/skin-repair agent.

Preclinical and clinical evidence for stem cell therapies as treatment for diabetic wounds

Diabetic wounds remain a global unsolved problem and the cost of diabetes-related amputations and diabetic wound treatment is approximately US$3 billion and US$9 billion per year, respectively. Diabetic foot ulcers (DFUs) occur in 15% of all patients with diabetes and precede 84% of all diabetes-related lower leg amputations. Currently, there is no satisfying treatment for these hard-to-heal-wounds. However, as we discuss here, experimental preclinical evidence for the successful use of adult stem cell therapies for diabetic wounds gives new hope for the development of effective treatments for use in the clinic.

Modulation of human mesenchymal stem cell survival on electrospun mesh with co-immobilized epithelial growth factor and gelatin

Co-immobilization of EGF and gelatin on a fibrous mesh promotes spreading and viability of hMSC, and coupled EGF involves involucrin expression and procollagen secretion, indicating trans-differentiation to keratinocyte-like cell.

Absence of feedback regulation in the synthesis of COL1A1

AIM

Recent studies have emphasized the importance of the extracellular microenvironment in modulating cell growth, motility, and signalling. In this study we have evaluated the ability of a fibroblast derived-extracellular matrix (fd-ECM) to regulate type I collagen synthesis and degradation in fibroblasts.

MAIN METHODS

Fibroblasts were plated on plastic (control) or on fd-ECM and type I collagen synthesis and degradation was evaluated. MTT, western blotting, real time PCR, zymographic analysis and inhibitor assays were utilised to investigate the molecular mechanism of type I collagen regulation by the fd-ECM.

KEY FINDINGS

Fibroblasts plated on fd-ECM showed significant downregulation in the production of type I collagen and COL1A2 messenger ribonucleic acid (mRNA) whilst COL1A1 mRNA remained unchanged. Cells grown on fd-ECM exhibited increased matrix metalloproteases (MMPs) and their corresponding mRNAs. The use of transforming growth factor β (TGF-β) and MMP inhibitors showed that the excess COL1A1 polypeptide chains were degraded by the combined action of MMP-1, MMP-2, MMP-9 and cathepsins.

SIGNIFICANCE

These results show the crucial role played by proteases in regulating extracellular matrix protein levels in the feedback regulation of connective tissue gene expression.

Epidermal growth factor, from gene organization to bedside

In 1962, epidermal growth factor (EGF) was discovered by Dr. Stanley Cohen while studying nerve growth factor (NGF). It was soon recognized that EGF is the prototypical member of a family of peptide growth factors that activate the EGF receptors, and that the EGF/EGF receptor signaling pathway plays important roles in proliferation, differentiation and migration of a variety of cell types, especially in epithelial cells. After the basic characterization of EGF function in the first decade or so after its discovery, the studies related to EGF and its signaling pathway have extended to a broad range of investigations concerning its biological and pathophysiological roles in development and in human diseases. In this review, we briefly describe the gene organization and tissue distribution of EGF, with emphasis on its biological and pathological roles in human diseases.

Ciprofloxacin has antifibrotic effects in scleroderma fibroblasts via downregulation of Dnmt1 and upregulation of Fli1

Systemic sclerosis (SSc) is characterized by fibrosis of the skin and internal organs. The present study was undertaken to examine the effects of ciprofloxacin, a fluoroquinolone antibiotic implicated in matrix remodeling, on dermal and lung fibroblasts obtained from SSc patients. Dermal and lung fibroblasts from SSc patients and healthy subjects were treated with ciprofloxacin. Western blotting was used to analyze protein levels and RT-PCR was used to measure mRNA expression. The pharmacologic inhibitor UO126 was used to block Erk1/2 signaling. SSc dermal fibroblasts demonstrated a significant decrease in collagen type I mRNA and protein levels after antibiotic treatment, while healthy dermal fibroblasts were less sensitive to ciprofloxacin, downregulating collagen only at the protein levels. Connective tissue growth factor (CCN2) gene expression was significantly reduced and matrix metalloproteinase 1 (MMP1) levels were enhanced after ciprofloxacin treatment to a similar extent in healthy and SSc fibroblasts. Ciprofloxacin induced Erk1/2 phosphorylation, and Erk1/2 blockade completely prevented MMP1 upregulation. However, Smad1 and Smad3 activation in response to TGFβ was not affected. The expression of friend leukemia integration factor 1 (Fli1), a transcriptional repressor of collagen, was increased after treatment with ciprofloxacin only in SSc fibroblasts, and this was accompanied by a decrease in the levels of DNA methyltransferase 1 (Dnmt1). Similar effects were observed in SSc-interstitial lung disease (ILD) lung fibroblasts. In summary, our study demonstrates that ciprofloxacin has antifibrotic actions in SSc dermal and lung fibroblasts via the downregulation of Dnmt1, the upregulation of Fli1 and induction of MMP1 gene expression via an Erk1/2-dependent mechanism. Thus, our data suggest that ciprofloxacin may be an attractive therapy for SSc skin and lung fibrosis.

Development of a cell-derived matrix: effects of epidermal growth factor in chemically defined culture

Extracellular matrices without animal components and with high mechanical strength are needed for the development of the next generation of viable skin replacements. The goal of this study was to determine the optimal concentration of epidermal growth factor (EGF) to maximize the strength and collagen content of cell-derived matrix (CDM) produced by fibroblasts in vitro in serum-free media. Scaffold-free CDM samples were produced by human dermal fibroblasts in the presence of 0-50 ng/mL EGF in chemically defined media. After 21 days of culture, a membrane inflation system was used to measure the biaxial tensile strength, failure stretch ratio, and thickness of each treatment group. The fibroblasts treated with 5 ng/mL EGF produced the thickest matrix (270 microm). A thinner (130 microm) matrix, produced when the fibroblasts were treated with 0.5 ng/mL, had an ultimate tensile strength (895 kPa), greater than two times that of the other treatment groups. The fibroblasts treated with 0.5 ng/mL also had the highest collagen density (23.5 mg/cm(3)). Fibroblasts stimulated with the lowest (0.05 ng/mL) and highest (50 ng/mL) concentrations of EGF produced significantly weaker matrices and lower collagen densities. There was no significant correlation between UTS and collagen density suggesting that mechanisms other than density contribute to the strength of the matrix. Taken together, these data indicate that the optimal EGF concentration depends upon the relative importance of matrix strength and volume in a given application and that 0.5-5.0 ng/mL EGF promotes production of a robust extracellular matrix in only 3 weeks.

Altered molecular mechanisms of diabetic foot ulcers

The continuously increasing worldwide prevalence of diabetes will be accompanied by a greater incidence of diabetic foot ulcer, a complication in which many of the morphological processes involved in normal wound healing are disrupted. The highly complex and integrated process of wound healing is regulated by a large array of molecular factors. These often have overlapping functions, ensuring a certain degree of tolerance through redundancy. In diabetes, changes to the expression of a large number of molecular factors have been observed, overwhelming this inbuilt redundancy. This results in delayed healing or incomplete healing as in ulceration. Understanding the relationship between altered levels of molecular factors and the inhibited healing process in such ulcers will permit the development of targeted treatments aimed to greatly improve the quality of life of patients, at the same time helping to reduce the huge costs associated with treating this diabetic condition and its long-term consequences. This short review examines how changes in the expression of molecular factors are related to altered morphology in diabetic foot ulceration and very briefly considers treatment strategies at molecular level.

Epidermal growth factor upregulates motility of Mat-LyLu rat prostate cancer cells partially via voltage-gated Na+ channel activity

The main aim of this investigation was to determine whether a functional relationship existed between epidermal growth factor (EGF) and voltage-gated sodium channel (VGSC) upregulation, both associated with strongly metastatic prostate cancer cells. Incubation with EGF for 24 h more than doubled VGSC current density. Similar treatment with EGF significantly and dose-dependently enhanced the cells' migration through Transwell filters. Both the patch clamp recordings and the migration assay suggested that endogenous EGF played a similar role. Importantly, co-application of EGF and tetrodotoxin, a highly selective VGSC blocker, abolished 65% of the potentiating effect of EGF. It is suggested that a significant portion of the EGF-induced enhancement of migration occurred via VGSC activity.