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1

Issues within Keratinocyte Growth Factor (KGF) research  

Microsoft Academic Search

As the seventh member of Fibroblast Growth Factor (FGF) family, Keratinocyte Growth Factor (KGF or FGF-7) is observed to mediate\\u000a epithelial cell proliferation and differentiation in a variety of tissues. In this article, such following issues within KGF\\u000a research were reviewed, as (1) KGF functioning pathways: experimental results demonstrated the paracrine pathway of KGF played\\u000a main role in mesenchymal-epithelial interactions

Zheng Wen-jing; Yuan Li; Liu Xue-dong; Zheng Dong

2005-01-01

2

Keratinocyte Growth Factor Causes Proliferation of Urothelium In Vivo  

Microsoft Academic Search

PurposeTo determine the effect of keratinocyte growth factor (KGF), a mesenchymally derived epithelial growth factor that can cause proliferation of pulmonary, gastrointestinal and mammary epithelia, on urothelium.

Eunhee S. Yi; Ahmed S. Shabaik; David L. Lacey; Adriana A. Bedoya; Songmei Yin; Regina M. Housley; Dimitry M. Danilenko; William Benson; Arthur M. Cohen; Glenn F. Pierce; Arlen Thomason

1995-01-01

3

Keratinocyte Growth Inhibition by High-Dose Epidermal Growth Factor Is Mediated by Transforming Growth Factor ? Autoinduction: A Negative Feedback Mechanism for Keratinocyte Growth  

Microsoft Academic Search

The epidermal growth factor receptor and its ligands initiate a major signaling pathway that regulates keratinocyte growth in an autocrine manner. It is well known that high doses of epidermal growth factor receptor ligands inhibit keratinocyte growth. Recently, signal transducers and activators of transcription 1-dependent p21Waf1\\/Cip1 induction were reported to be involved in high-dose epidermal growth factor-dependent cell growth arrest

Kenshi Yamasaki; Nobuko Toriu; Yasushi Hanakawa; Yuji Shirakata; Koji Sayama; Atsushi Takayanagi; Masafumi Ohtsubo; Shinobu Gamou; Nobuyoshi Shimizu; Makiko Fujii; Kohei Miyazono; Koji Hashimoto

2003-01-01

4

Mechanisms of hepatocyte growth factor stimulation of keratinocyte metalloproteinase production.  

PubMed

Matrix metalloproteinases participate in normal physiologic processes; however, their overproduction has been associated with connective tissue destruction in a variety of pathological states. Migrating basal keratinocytes transiently express collagenase-1 during normal cutaneous reepithelialization. However, the overexpression of both collagenase-1 and stromelysin-1 has been associated with the pathogenesis of chronic nonhealing ulcers. Aberrant expression of metalloproteinases in inflammation is mediated, at least in part, by soluble factors. Since hepatocyte growth factor/scatter factor (HGF/SF) has been reported to promote keratinocyte migration and proliferation, key events in wound repair, and since HGF/SF is produced by dermal fibroblasts and its c-Met receptor is expressed by basal keratinocytes in wounded skin, we have studied the effects of HGF/SF upon keratinocyte metalloproteinase expression. We have found that HGF/SF can stimulate keratinocyte collagenase-1 and stromelysin-1 production in a dose-dependent and matrix-dependent manner. Expression of 92-kDa gelatinase was not affected by HGF/SF. We determined that HGF/SF regulation of collagenase-1 expression is transcriptionally mediated and requires tyrosine kinase and protein kinase C activaties. HGF/NK1, a naturally occurring, truncated form of HGF/SF, also stimulates collagenase-1 production, but much less efficiently than does the parent molecule. However, HGF/NK2, another HGF/SF splice variant, as well as heparin, potently inhibit HGF/SF-induced collagenase-1 synthesis. These results indicate that HGF/SF and its naturally occurring splice variants have diverse biological effects on keratinocytes and suggest an additional mechanism whereby HGF/SF may regulate keratinocyte function during wound repair. PMID:8798721

Dunsmore, S E; Rubin, J S; Kovacs, S O; Chedid, M; Parks, W C; Welgus, H G

1996-10-01

5

Epidermal Growth Factor and Insulin-Like Growth Factor I Enhance Keratinocyte Migration  

Microsoft Academic Search

Although their mechanisms of action are unclear, a number of growth factors has been shown to promote cutaneous wound repair. Keratinocyte migration and proliferation are required for re-epithelialization, and there is evidence to suggest that these processes may be regulated by one or more growth factors that promote wound repair. Using the phagokinetic assay, which allows direct observation of migration

Yoshihiro Ando; Pamela J. Jensen

1993-01-01

6

Hepatocyte Growth Factor, Keratinocyte Growth Factor, Their Receptors, Fibroblast Growth Factor Receptor2, and the Cells of the Cornea  

Microsoft Academic Search

Purpose. The purpose of this study was to determine whether messenger RNA coding for hepatocyte growth factor (HGF), HGF receptor (MET), keratinocyte growth factor (KGF), KGF receptor, and fibroblast growth factor (FGF) receptor-2 were produced in primary cul- tures of human corneal epithelial, stromal fibroblast, and endothelial cells, as well as ex vivo corneal epithelium, endothelial cells transfected with the

Steven E. Wilson; Joel W. Walker; Eric L. Chwang; Yu-Guang He

7

Keratinocyte Growth Factor Accelerates Corneal Epithelial Wound Healing In Vivo  

Microsoft Academic Search

Purpose. To examine whether the topical application of keratinocyte growth factor (KGF) can enhance corneal epithelial healing in vivo. In addition, the distribution of S-phase cells in KGF-treated and control corneas was investigated during regeneration and under normal conditions. Methods. A 10-mm diameter epithelial defect was made in the center of rabbit corneas. A 50- fA aliquot of 10 \\/\\/g\\/ml

Chie Sotozono; Tsutomu Inatomi; Masatsugu Nakamura; Shigeru Kinoshita

8

Hepatocyte and keratinocyte growth factors and their receptors in human lung emphysema  

PubMed Central

Background Hepatocyte and keratinocyte growth factors are key growth factors in the process of alveolar repair. We hypothesized that excessive alveolar destruction observed in lung emphysema involves impaired expression of hepatocyte and keratinocyte growth factors or their respective receptors, c-met and keratinocyte growth factor receptor. The aim of our study was to compare the expression of hepatocyte and keratinocyte growth factors and their receptors in lung samples from 3 groups of patients: emphysema; smokers without emphysema and non-smokers without emphysema. Methods Hepatocyte and keratinocyte growth factor proteins were analysed by immunoassay and western blot; mRNA expression was measured by real time quantitative polymerase chain reaction. Results Hepatocyte and keratinocyte growth factors, c-met and keratinocyte growth factor receptor mRNA levels were similar in emphysema and non-emphysema patients. Hepatocyte growth factor mRNA correlated negatively with FEV1 and the FEV1/FVC ratio both in emphysema patients and in smokers with or without emphysema. Hepatocyte and keratinocyte growth factor protein concentrations were similar in all patients' groups. Conclusion The expression of hepatocyte and keratinocyte growth factors and their receptors is preserved in patients with lung emphysema as compared to patients without emphysema. Hepatocyte growth factor mRNA correlates with the severity of airflow obstruction in smokers.

Bonay, Marcel; Boutten, Anne; Lecon-Malas, Veronique; Marchal, Joelle; Soler, Paul; Fournier, Michel; Leseche, Guy; Dehoux, Monique; Crestani, Bruno

2005-01-01

9

Cortactin involvement in the keratinocyte growth factor and fibroblast growth factor 10 promotion of migration and cortical actin assembly in human keratinocytes  

SciTech Connect

Keratinocyte growth factor (KGF/FGF7) and fibroblast growth factor 10 (FGF10/KGF2) regulate keratinocyte proliferation and differentiation by binding to the tyrosine kinase KGF receptor (KGFR). KGF induces keratinocyte motility and cytoskeletal rearrangement, whereas a direct role of FGF10 on keratinocyte migration is not clearly established. Here we analyzed the motogenic activity of FGF10 and KGF on human keratinocytes. Migration assays and immunofluorescence of actin cytoskeleton revealed that FGF10 is less efficient than KGF in promoting migration and exerts a delayed effect in inducing lamellipodia and ruffles formation. Both growth factors promoted phosphorylation and subsequent membrane translocation of cortactin, an F-actin binding protein involved in cell migration; however, FGF10-induced cortactin phosphorylation was reduced, more transient and delayed with respect to that promoted by KGF. Cortactin phosphorylation induced by both growth factors was Src-dependent, while its membrane translocation and cell migration were blocked by either Src and PI3K inhibitors, suggesting that both pathways are involved in KGF- and FGF10-dependent motility. Furthermore, siRNA-mediated downregulation of cortactin inhibited KGF- and FGF10-induced migration. These results indicate that cortactin is involved in keratinocyte migration promoted by both KGF and FGF10.

Ceccarelli, Simona [Dipartimento di Medicina Sperimentale, Universita di Roma 'La Sapienza', Viale Regina Elena 324, 00161, Rome (Italy); Cardinali, Giorgia [Istituto Dermatologico San Gallicano, IRCCS, Rome (Italy); Aspite, Nicaela [Istituto Dermatologico San Gallicano, IRCCS, Rome (Italy); Picardo, Mauro [Istituto Dermatologico San Gallicano, IRCCS, Rome (Italy); Marchese, Cinzia [Dipartimento di Medicina Sperimentale, Universita di Roma 'La Sapienza', Viale Regina Elena 324, 00161, Rome (Italy); Torrisi, Maria Rosaria [Dipartimento di Medicina Sperimentale, Universita di Roma 'La Sapienza', Viale Regina Elena 324, 00161, Rome (Italy); Azienda Ospedaliera Sant'Andrea, Rome (Italy); Mancini, Patrizia [Dipartimento di Medicina Sperimentale, Universita di Roma 'La Sapienza', Viale Regina Elena 324, 00161, Rome (Italy)]. E-mail: patrizia.mancini@uniroma1.it

2007-05-15

10

Keratinocyte growth factor (KGF) is required for postnatal thymic regeneration  

PubMed Central

Keratinocyte growth factor (KGF) is a member of the fibroblast growth factor family that mediates epithelial cell proliferation and differentiation in a variety of tissues, including the thymus. We studied the role of KGF in T-cell development with KGF-/- mice and demonstrated that thymic cellularity and the distribution of thymocyte subsets among KGF-/-, wildtype (WT), and KGF+/- mice were similar. However, KGF-/- mice are more vulnerable to sublethal irradiation (450 cGy), and a significant decrease was found in thymic cellularity after irradiation. Defective thymopoiesis and peripheral T-cell reconstitution were found in KGF-/- recipients of syngeneic or allogeneic bone marrow transplant, but using KGF-/- mice as a donor did not affect T-cell development after transplantation. Despite causing an early developmental block in the thymus, administration of KGF to young and old mice enhanced thymopoiesis. Exogenous KGF also accelerated thymic recovery after irradiation, cyclophosphamide, and dexamethasone treatment. Finally, we found that administering KGF before bone marrow transplantation (BMT) resulted in enhanced thymopoiesis and peripheral T-cell numbers in middle-aged recipients of an allogeneic BM transplant. We conclude that KGF plays a critical role in postnatal thymic regeneration and may be useful in treating immune deficiency conditions. (Blood. 2006;107:2453-2460)

Alpdogan, Onder; Hubbard, Vanessa M.; Smith, Odette M.; Patel, Neel; Lu, Sydney; Goldberg, Gabrielle L.; Gray, Daniel H.; Feinman, Jared; Kochman, Adam A.; Eng, Jeffrey M.; Suh, David; Muriglan, Stephanie J.; Boyd, Richard L.; van den Brink, Marcel R. M.

2006-01-01

11

Keratinocyte growth factor is highly overexpressed in inflammatory bowel disease.  

PubMed Central

Recently we demonstrated an important function of keratinocyte growth factor (KGF) in wound re-epithelialization. As KGF is mitogenic for various epithelial cells, we speculated about a role of KGF in epithelial repair processes of other organs as seen in a variety of inflammatory diseases. Here we demonstrate a strikingly increased expression of KGF in surgical specimens from patients suffering from Crohn's disease and ulcerative colitis. The levels of KGF expression strongly correlated with the degree of inflammation as assessed by histological analysis of adjacent tissue and expression analysis of the pro-inflammatory cytokine interleukin-1 beta. The highest levels of KGF mRNA and protein were found in mesenchymal cells of the lamina propria, particularly in highly inflamed areas. As the KGF receptor is expressed in intestinal epithelial cells, KGF seems to act in a paracrine manner to stimulate proliferation of these cells. These data suggest a crucial role of KGF in epithelial repair after injury caused by inflammatory processes. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

Brauchle, M.; Madlener, M.; Wagner, A. D.; Angermeyer, K.; Lauer, U.; Hofschneider, P. H.; Gregor, M.; Werner, S.

1996-01-01

12

Expression and Function of Keratinocyte Growth Factor and Activin in Skin Morphogenesis and Cutaneous Wound Repair  

Microsoft Academic Search

Reepithelialization and granulation tissue formation during cutaneous wound repair are mediated by a wide variety of growth and differentiation factors. Recent studies from our laboratory provided evidence for an important role of keratinocyte growth factor (KGF) in the repair of the injured epithelium and for a novel function of the transforming growth factor-? superfamily member activin in granulation tissue formation.

Hans-Dietmar Beer; Marcus G. Gassmann; Barbara Munz; Heike Steiling; Felix Engelhardt; Kerstin Bleuel; Sabine Werner

2000-01-01

13

Fibrin Stimulates the Proliferation of Human Keratinocytes through the Autocrine Mechanism of Transforming Growth Factor-? and Epidermal Growth Factor Receptor  

Microsoft Academic Search

YAMAMOTO, M., YANAGA, H., NISHINA, H., WATABE, S. and MAMBA, K. Fibrin Stimu- lates the Proliferation of Human Keratinocytes through the Autocrine Mechanism of Transforming Growth Factor-? and Epidermal Growth Factor Receptor. Tohoku J. Exp. Med., 2005, 207 (1), 33-40 ?? In the field of dermatology and plastic and reconstructive surgery, fibrin gel is regarded as a material that promotes

Misa Yamamoto; Hiroko Yanaga; Hiromichi Nishina; Shoji Watabe; Koichi Mamba

2005-01-01

14

Modulation of growth and differentiation in normal human keratinocytes by transforming growth factor-beta  

SciTech Connect

The effect of transforming growth factor-type beta 1(TGF-beta) on the growth and differentiation of normal human skin keratinocytes cultured in serum-free medium was investigated. TGF-beta markedly inhibited the growth of keratinocytes at the concentrations greater than 2 ng/ml under low Ca2+ conditions (0.1 mM). Growth inhibition was accompanied by changes in cell functions related to proliferation. Remarkable inhibition of DNA synthesis was demonstrated by the decrease of (3H)thymidine incorporation. The decrease of (3H)thymidine incorporation was observed as early as 3 hr after addition of TGF-beta. TGF-beta also decreased c-myc messenger RNA (mRNA) expression 30 min after addition of TGF-beta. This rapid reduction of c-myc mRNA expression by TGF-beta treatment is possibly one of the main factors in the process of TGF-beta-induced growth inhibition of human keratinocytes. Since growth inhibition and induction of differentiation are closely related in human keratinocytes, the growth-inhibitory effect of TGF-beta under high Ca2+ conditions was examined. TGF-beta inhibited the growth of keratinocytes under high Ca2+ conditions in the same manner as under low Ca2+ conditions, suggesting that it is a strong growth inhibitor in both low and high Ca2+ environments. The induction of keratinocyte differentiation was evaluated by measuring involucrin expression and cornified envelope formation: TGF-beta at 20 ng/ml increased involucrin expression from 9.3% to 18.8% under high Ca2+ conditions, while it decreased involucrin expression from 7.0% to 3.3% under low Ca2+ conditions. Cornified envelope formation was modulated in a similar way by addition of TGF-beta: TGF-beta at 20 ng/ml decreased cornified envelope formation by 53% under low Ca2+ conditions, while it enhanced cornified envelope formation by 30.7% under high Ca2+ conditions.

Matsumoto, K.; Hashimoto, K.; Hashiro, M.; Yoshimasa, H.; Yoshikawa, K. (Osaka Univ. School of Medicine (Japan))

1990-10-01

15

Effect of nifedipine on the expression of keratinocyte growth factor and its receptor in cocultured/monocultured fibroblasts and keratinocytes.  

PubMed

BACKGROUND AND OBJECTIVE: Keratinocyte growth factor (KGF) and its receptor (KGFR) are involved in hyperplastic diseases. This study explored the effect of intercellular communication on KGF and KGFR in cocultured/monocultured gingival fibroblasts and keratinocytes following treatment with nifedipine. MATERIAL AND METHODS: Human gingival fibroblasts and keratinocytes were monocultured and cocultured, respectively. MTT was used to investigate the effects of nifedipine on the proliferation of gingival fibroblasts and keratinocytes. Monoculture and coculture systems were treated with different concentrations (0, 0.2 or 20 ?g/mL) of nifedipine, and the expression of KGF and KGFR mRNAs was examined by RT-PCR, whilst the secretion of KGF and the expression of KGFR on the membrane were analyzed using ELISA and flow cytometry, respectively. RESULTS: Nifedipine (0, 0.2 and 20 ?g/mL) had no influence on cell proliferation within 3 d. KGF and KGFR mRNAs were up-regulated, but only in the cocultures. In coculture, the secretion of KGF was significantly increased by nifedipine, while it was only significantly up-regulated by 20 ?g/mL of nifedipine in monoculture. Moreover, the level of KGFR protein in the membrane was significantly increased by 20 ?g/mL of nifedipine in monocultures, while it was significantly down-regulated by 20 ?g/mL of nifedipine in cocultures. CONCLUSION: The expression of KGF and KGFR are influenced by the interplay of gingival keratinocytes and fibroblasts. Epithelial keratinocytes and mesenchymal fibroblasts may interplay to dynamically regulate gene expression, which may have an effect on the gingival condition following treatment with nifedipine. PMID:23528007

Di, C-P; Sun, Y; Zhao, L; Li, L; Ding, C; Xu, Y; Fan, Y

2013-03-25

16

Keratinocyte Growth Factor Prevents Ventilator-induced Lung Injury in an Ex Vivo Rat Model  

Microsoft Academic Search

Mechanical ventilation has been shown to produce lung injury characterized by noncardiogenic pulmonary edema. Keratinocyte growth factor (KGF) is a heparin-binding growth factor that causes alveolar type II pneumocyte hyperplasia. KGF pretreatment and the resultant pneumocyte hyperplasia reduce fluid flux in models of lung injury. We utilized the isolated perfused rat lung model to produce lung injury by varying tidal

DAVID A. WELSH; WARREN R. SUMMER; ELIZABETH P. DOBARD; STEVE NELSON; CAROL M. MASON

17

KERATINOCYTE GROWTH FACTOR IS UPREGULATED BY THE HYPERPLASIA-INDUCING DRUG NIFEDIPINE  

Microsoft Academic Search

Keratinocyte growth factor (KGF) is the seventh member of the fibroblast growth factor (FGF) family. It is produced by mesenchymal cells and its activity is specific for epithelial cells, controlling epithelial homeostasis and wound repair in a paracrine manner. Although KGF has been implicated in a number of hyperplastic pathologies, it has not previously been investigated in gingival hyperplasia (GH),

Swarga Jyoti Das; Irwin Olsen

2000-01-01

18

Silencing of Keratinocyte Growth Factor Receptor Restores 5Fluorouracil and Tamoxifen Efficacy on Responsive Cancer Cells  

Microsoft Academic Search

BackgroundKeratinocyte growth factor receptor (KGFR) is a splice variant of the FGFR2 gene expressed in epithelial cells. Activation of KGFR is a key factor in the regulation of physiological processes in epithelial cells such as proliferation, differentiation and wound healing. Alterations of KGFR signaling have been linked to the pathogenesis of different epithelial tumors. It has been also hypothesized that

Sabrina Rotolo; Simona Ceccarelli; Ferdinando Romano; Luigi Frati; Cinzia Marchese; Antonio Angeloni; Stefan Maas

2008-01-01

19

Keratinocyte Growth Factor Modulates Alveolar Epithelial Cell Phenotype In Vitro : Expression of Aquaporin 5  

Microsoft Academic Search

We investigated the role of keratinocyte growth factor (KGF) in regulation of alveolar epithelial cell (AEC) phenotype in vitro. Effects of KGF on cell morphology, expression of surfactant apoproteins A, B, and C (SP-A, -B, and -C), and expression of aquaporin 5 (AQP5), a water channel present in situ on the apical surface of alveolar type I (AT1) cells but

Zea Borok; Richard L. Lubman; Spencer I. Danto; Xiao-Ling Zhang; Stephanie M. Zabski; Landon S. King; Douglas M. Lee; Peter Agre; Edward D. Crandall

20

Keratinocyte response to immobilized growth factors for enhanced dermal wound healing  

NASA Astrophysics Data System (ADS)

Chronic wounds cost billions of dollars per year to treat and wound care is limited to ineffective and/or expensive options. Chronic wounds are characterized by a failure to reepithelialize, as well as deficiencies in growth factors, such as epidermal growth factor (EGF) and insulin-like growth factor-1 (IGF-1), normally present during wound healing. Our system described herein begins to tackle the problems associated with designing bioactive materials for chronic wound healing applications. We show that we can induce accelerated keratinocyte migration with photo-immobilized EGF and further control migration speed through the culture of cells on different types of gradient patterns of EGF. We also successfully immobilized IGF-1 while retaining its bioactivity, and further showed it induces directed keratinocyte migration, although not as potently as immobilized EGF. Potential synergy between co-immobilized IGF-1 and EGF was also investigated, although EGF continued to dominate the cellular response, and no significant increase in cell migration was achieved via the addition of IGF-1 to the system. To further understand cellular response to our immobilized growth factors, we investigated keratinocyte signaling and function in response to changes in EGF presentation. It was found that immobilized and soluble EGF can play different, yet complementary, roles in regulating keratinocyte function. Specifically, keratinocytes responded to immobilized EGF with high EGF receptor (EGFR) activation, accompanied by low proliferation and high migratory activity. In contrast, keratinocytes treated with soluble EGF displayed a highly proliferative, rather than migratory, phenotype. We then transitioned our photo-immobilization techniques to materials that may be more suitable as a wound dressing, such as silk fibroin films. Silk fibroin is a natural fiber with many desirable qualities for a biomaterial including high strength and elasticity, biocompatibility, a beta-keratin structure which closely mimics human keratin, and ease of fabrication and modification. These silk films can also provide topographical cues via simple cast molding of any feature on the micron scale. This system allowed simultaneous presentation of topographic cues, inhibitory and/or synergistic, with our chemotactic cues. Our preliminary data suggest keratinocytes remain viable on silk fibroin films, and that these films can be patterned with immobilized EGF to induce keratinocyte migration.

Stefonek-Puccinelli, Tracy Jane

21

Expression of keratinocyte growth factor and its receptor in human breast cancer  

Microsoft Academic Search

The level of expression of keratinocyte growth factor (KGF) mRNA has been measured in human breast cell lines, purified populations of epithelial cells, myoepithelial cells and fibroblasts from reduction mammoplasty tissue and a panel of 42 breast cancers and 30 non-malignant human breast tissues using a semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR) procedure. We found similar levels of KGF

GS Bansal; HC Cox; S Marsh; JJ Gomm; C Yiangou; Y Luqmani; RC Coombes; CL Johnston

1997-01-01

22

Keratinocyte growth factor prevents intra-alveolar oedema in experimental lung isografts  

Microsoft Academic Search

Primary graft dysfunction, characterised by intra-alveolar oedema, is a major obstacle in pulmonary transplantation. The present study evaluates the potential of keratinocyte growth factor (palmiferin; DN23-KGF) for the prevention of oedema in lung transplants. Intratracheal instillation of 5 mg?kg-1 DN23-KGF was performed in Lewis rats on days 3 and 2 before explantation. Control animals obtained an equivalent volume of vehicle.

J. Sadovski; T. Kuchenbuch; C. Ruppert; A. Fehrenbach; M. Hirschburger; W. Padberg; A. Gunther; J. M. Hohlfeld; H. Fehrenbach; V. Grau

2008-01-01

23

Insulin-Like Growth Factors are Mitogenic for Human Keratinocytes and a Squamous Cell Carcinoma  

Microsoft Academic Search

Normal adult human keratinocytes in monolayer culture and SCL-1, a skin-derived squamous-cell carcinoma cell line, were investigated for the expression of receptors for insulin- like growth factors (IGF) and insulin. As demonstrated by affinity crosslinking, radiolabeled IGF-1, IGF-2, and insulin bound specifically to both cell types. Each cell expressed type I IGF receptors, with affinity for IGF-1 > IGF-2 >>

E. Kirk Neely; Vera B. Morhenn; Raymond L. Hintz; Darrell M. Wilson; Ron G. Rosenfeld

1991-01-01

24

Autocrine Stimulation of Interleukin-1(alpha) and Transforming Growth Factor(alpha) Production in Human Keratinocytes and Its Antagonism by Glucocorticoids.  

National Technical Information Service (NTIS)

Interleukin-1 (IL-1) and transforming growth factor alpha (TGF alpha) mRNA expression were analyzed in cultured normal human keratinocytes. Keratinocytes express IL-1 mRNA when cultured in keratinocyte growth medium but not in Dulbecco's minimal essential...

S. W. Lee V. B. Morhenn M. Ilnicka E. M. Eugui A. C. Allison

1989-01-01

25

Fibroblast Growth Factor-Peptide Improves Barrier Function and Proliferation in Human Keratinocytes After Radiation  

SciTech Connect

Purpose: Epidermal keratinocytes, which can be severely damaged after ionizing radiation (IR), are rapid turnover cells that function as a barrier, protecting the host from pathogenic invasion and fluid loss. We tested fibroblast growth factor-peptide (FGF-P), a small peptide derived from the receptor-binding domain of FGF-2, as a potential mitigator of radiation effects via proliferation and the barrier function of keratinocytes. Methods and Materials: Keratinocytes isolated from neonatal foreskin were grown on transwells. After being exposed to 0, 5, or 10 Gy IR, the cells were treated with a vehicle or FGF-P. The permeability of IR cells was assessed by using transepithelial electrical resistance (TEER) and a paracellular tracer flux of fluorescein isothiocyanate-conjugated bovine serum albumin (FITC-BSA) with Ussing chambers. The cell proliferation was measured with yellow tetrazolium salt (MTT) and tritiated thymidine ([{sup 3}H]-TdR) assays. The phosphorylation of extracellular signal-regulated kinases (ERK) was measured in an enzyme-linked immunosorbent (ELISA)-like assay, and the proteins related to tight junctions (TJ) and adherens junctions (AJ) were examined with Western blotting. We used a mouse model to assess the ability of FGF-P to promote the healing of skin {beta} burns created with a strontium applicator. Results: We found (1) FGF-P reduced the permeability of irradiated keratinocytes, as evidenced by increased TEER and decreased diffusion of FITC-BSA, both associated with the regulation of different proteins and levels of TJ and AJ; and (2) FGF-P enhanced the proliferation of irradiated keratinocytes, as evidenced by increased MTT activity and [{sup 3}H]-TdR incorporation, which was associated with activation of the ERK pathway; and (3) FGF-P promoted the healing of skin {beta} burns. Conclusions: FGF-P enhances the barrier function, including up-regulation of TJ proteins, increases proliferation of human keratinocytes, and accelerates the healing of skin {beta} burns. FGF-P is a promising mitigator that improves the proliferation and barrier function of keratinocytes after IR.

Zhang Kunzhong [Department of Radiation Oncology, University of Rochester Medical Center, Rochester, New York 14642 (United States); Tian Yeping [Second Military Medical College, Shanghai, P.R. China 200433 (China); Yin Liangjie; Zhang Mei [Department of Radiation Oncology, University of Florida, Gainesville Florida 32610 (United States); Beck, Lisa A. [Department of Dermatology, University of Rochester Medical Center, Rochester, New York 14642 (United States); Zhang, Bingrong; Okunieff, Paul [Department of Radiation Oncology, University of Florida, Gainesville Florida 32610 (United States); Zhang Lurong, E-mail: lurongzhang@ufl.edu [Department of Radiation Oncology, University of Florida, Gainesville Florida 32610 (United States); Vidyasagar, Sadasivan, E-mail: vidyasagar@ufl.edu [Department of Radiation Oncology, University of Florida, Gainesville Florida 32610 (United States)

2011-09-01

26

Modulation of keratinocyte growth factor and its receptor in reepithelializing human skin  

PubMed Central

We investigated the expression and distribution of keratinocyte growth factor (KGF) (FGF-7) and its receptor (KGFR) during reepithelialization of human skin. KGF mRNA levels increased rapidly by 8-10-fold and remained elevated for several days. In contrast, KGFR transcript levels decreased early but were significantly elevated by 8-9 d. A KGF- immunoglobulin G fusion protein (KGF-HFc), which specifically and sensitively detects the KGFR, localized the receptor to differentiating keratinocytes of control epidermis, but revealed a striking decrease in receptor protein expression during the intermediate period of reepithelization. Suramin, which blocked KGF binding and stripped already bound KGF from its receptor, failed to unmask KGFRs in tissue sections from the intermediate phase of wound repair. The absence of KGFR protein despite increased KGFR transcript levels implies functional receptor downregulation in the presence of increased KGF. This temporal modulation of KGF and KGFRs provides strong evidence for the functional involvement of KGF in human skin reepithelialization.

1995-01-01

27

Ultraviolet Irradiation-Induces Epidermal Growth Factor Receptor (EGFR) Nuclear Translocation in Human Keratinocytes  

PubMed Central

Epidermal growth factor receptor (EGFR) plays a critical role in mediating ultraviolet (UV) irradiation-induced signal transduction and gene expression in human keratinocytes. EGFR activation results from increased phosphorylation on specific tyrosine residues in the C-terminal intracellular domain. It has recently been reported that following growth factor stimulation EGFR translocates from the surface membrane to the nucleus, where it may directly regulate gene transcription. We have investigated the ability of UV irradiation to induce EGFR nuclear translocation in human primary and HaCaT keratinocytes. UV irradiation caused rapid nuclear translocation of EGFR. Significant accumulation of EGFR in the nucleus was observed within fifteen minutes after UV irradiation exposure. Maximal translocation occurred at 30 minutes post UV irradiation, and resulted in a 10-fold increase in EGFR in the nucleus, as determined by Western blot analysis of nuclear extracts and confirmed by immunofluorescence. Inhibition of nuclear export by Leptomycin B did not alter UV irradiation-induced nuclear accumulation. EGFR tyrosine kinase inhibitor (PD169540) reduced UV irradiation-induced EGFR nuclear translocation 50%. Mutation of either tyrosine 1148 or tyrosine 1173 reduced nuclear translocation 70%, while mutation of tyrosine 1068 was without effect. In addition, over-expression of receptor type protein tyrosine phosphatase-kappa (RPTP-?), which specifically dephosphorylates EGFR tyrosines, decreased UV irradiation-induced EGFR nuclear translocation in human keratinocytes. These data demonstrate that UV irradiation stimulates rapid EGFR nuclear translocation, which is dependent on phosphorylation of specific EGFR tyrosine residues. EGFR nuclear translocation may act in concert with conventional signaling pathways to mediate UV irradiation-induced responses in human keratinocytes.

Xu, Yiru; Shao, Yuan; Zhou, Jin; Voorhees, John J.; Fisher, Gary J.

2010-01-01

28

Attenuated Salmonella typhimurium carrying the hepatocyte growth factor and keratinocyte growth factor genes repairs gastrointestinal mucosal damage caused by chemotherapy.  

PubMed

Radiotherapy and chemotherapy are the main therapeutic approaches for patients with malignant tumours, especially advanced tumours. However, they can cause adverse effects, one of which is gastrointestinal mucosal damage, which can greatly affect patients' quality of life. Until now, there have been no effective therapies to avoid or treat these adverse effects. In this study, we used attenuated Salmonella typhimurium (S. typhimurium) to deliver the hepatocyte growth factor (HGF) or keratinocyte growth factor (KGF) to murine gastrointestinal mucosa. We found that attenuated S. typhimurium carrying the HGF or KGF genes can effectively reduce the ratio of tumour to non-tumour carcass weight, repair damage to the gastrointestinal mucosal from chemotherapy, improve the immune response, and reduce the mortality rate of mice. Oral administration of attenuated S. typhimurium with HGF and KGF may be promising as a way of improving the quality of life of patients undergoing radiotherapy and chemotherapy. PMID:23335069

Sun, Jun-Zhong; Ha, Xiao-Qin; Zhang, Li-Ming; Wang, Hai-Bin; Wang, Hong-Wei; Duan, Hai-Feng

2013-01-19

29

Latent and Active Transforming Growth Factor ?1 Released from Genetically Modified Keratinocytes Modulates Extracellular Matrix Expression by Dermal Fibroblasts in a Coculture System  

Microsoft Academic Search

Transforming growth factor ?1 is a multifunctional cytokine involved in many aspects of wound healing. Here we report the effects of both latent and active transforming growth factor ?1 released from genetically modified keratinocytes on extracellular matrix expression by dermal fibroblasts in a coculture system. Human keratinocytes were genetically modified with adenovirus containing cDNA for latent transforming growth factor ?1

Barbara S. Bauer; Edward E. Tredget; Yvonne Marcoux; Paul G. Scott; Aziz Ghahary

2002-01-01

30

Insulin-Like Growth Factor 1 Receptor Signaling Regulates Skin Development and Inhibits Skin Keratinocyte Differentiation  

PubMed Central

The insulin-like growth factor 1 receptor (IGF-1R) is a multifunctional receptor that mediates signals for cell proliferation, differentiation, and survival. Genetic experiments showed that IGF-1R inactivation in skin results in a disrupted epidermis. However, because IGF-1R-null mice die at birth, it is difficult to study the effects of IGF-1R on skin. By using a combined approach of conditional gene ablation and a three-dimensional organotypic model, we demonstrate that IGF-1R-deficient skin cocultures show abnormal maturation and differentiation patterns. Furthermore, IGF-1R-null keratinocytes exhibit accelerated differentiation and decreased proliferation. Investigating the signaling pathway downstream of IGF-1R reveals that insulin receptor substrate 2 (IRS-2) overexpression compensates for the lack of IGF-1R, whereas IRS-1 overexpression does not. We also demonstrate that phosphatidylinositol 3-kinase and extracellular signal-regulated kinase 1 and 2 are involved in the regulation of skin keratinocyte differentiation and take some part in mediating the inhibitory signal of IGF-1R on differentiation. In addition, we show that mammalian target of rapamycin plays a specific role in mediating IGF-1R impedance of action on keratinocyte differentiation. In conclusion, these results reveal that IGF-1R plays an inhibitory role in the regulation of skin development and differentiation.

Sadagurski, Marianna; Yakar, Shoshana; Weingarten, Galina; Holzenberger, Martin; Rhodes, Christopher J.; Breitkreutz, Dirk; LeRoith, Derek; Wertheimer, Efrat

2006-01-01

31

Transforming growth factor beta1 induces differentiation in human papillomavirus-positive keratinocytes.  

PubMed Central

Human papillomaviruses (HPVs) are implicated in the etiology of anogenital cancers. Expression of the HPV E6 and E7 oncoproteins is believed to contribute to the carcinogenic process. Progressive loss of the ability to differentiate and resistance to the growth-inhibitory effects of endogenous signals also appear important in multistep tumorigenesis. Transforming growth factor beta1 (TGF-beta1) is a potent growth inhibitor for a variety of cultured cells. There have been conflicting reports on the ability of TGF-beta1 to inhibit the growth of HPV-positive keratinocytes in monolayer cultures. We have employed the organotypic (raft) tissue culture system, which more accurately mimics the in vivo cellular environment and architecture. We have investigated the TGF-beta1 response of HPV-positive keratinocytes derived from neoplastic cervical biopsies. Growth of these cell lines as raft tissues showed that many were altered in the ability to stratify and synthesize differentiation-specific proteins. When the organotypic tissues were treated with TGF-beta1, a more complete differentiation of the keratinocytes was induced. Treatment with 12-0-tetradecanoylphorbol-13-acetate gave similar results. TGF-beta1 treatment of HPV-positive raft epithelia led to a dose-dependent increase in E7 RNA expression in contrast to results from previous studies with monolayer cultures. Furthermore, TGF-beta1 interfered with the proliferation of HPV-positive cell lines grown in monolayer cultures. Our results suggest that loss of the ability to express markers of differentiation, a characteristic of malignancy, is a two-step process. The first step is reversible; the second is irreversible.

Ozbun, M A; Meyers, C

1996-01-01

32

Targeted Disruption of the Epidermal Growth Factor Receptor Inhibits Development of Papillomas and Carcinomas from Human Papillomavirus-immortalized Keratinocytes  

Microsoft Academic Search

The epidermal growth factor receptor (EGF-R) is frequently overex- pressed in human papillomavirus (HPV)-associated dysplasias and carci- nomas, implying that it is important for the progression of keratinocytes to malignancy. We used mice with a targeted disruption of the EGF-R gene to directly examine its role in cell immortalization and tumor devel- opment. Epidermal keratinocytes were cultured from EGF-R knockout,

Craig D. Woodworth; Darci Gaiotti; Evan Michael; Laura Hansen; Matthias Nees

2000-01-01

33

UVB-induced Senescence in Human Keratinocytes Requires a Functional Insulin-like Growth Factor1 Receptor and p53  

Microsoft Academic Search

To cope with the frequent exposure to carcinogenic UV B (UVB) wavelengths found in sunlight, keratinocytes have acquired extensive protective measures to handle UVB-induced DNA damage. Recent in vitro and epidemiological data suggest one these protective mechanisms is dependent on the functional status of the insulin-like growth factor-1 receptor (IGF-1R) signaling network in keratinocytes. During the normal UVB response, ligand-activated

Davina A. Lewis; Qiaofang Yi; Jeffrey B. Travers; Dan F Spandau

2008-01-01

34

Stimulation of all epithelial elements during skin regeneration by keratinocyte growth factor  

PubMed Central

Keratinocyte growth factor (KGF), a recently discovered 18.9 kD member of the fibroblast growth factor family has been shown to selectively induce keratinocyte proliferation and differentiation in tissue culture. To explore its potential stimulating keratinocyte growth and differentiation in vivo, we analyzed for the influence of KGF on epithelial derived elements within a wound created through the cartilage on the rabbit ear. KGF accelerated reepithelialization (p = 0.004) and increased the thickness of the epithelium (p = 0.0005) when 4-40 micrograms/cm2 recombinant KGF was added at the time of wounding. The regenerating epidermis showed normal differentiation as detected by cytokeratin immunostaining. Remarkably, however, KGF stimulated proliferation and differentiation of early progenitor cells within hair follicles and sebaceous glands in the wound bed and adjacent dermis. There was a transient but highly significant increase in specific labeling of cycling cells in both basal and suprabasal layers that extended into the spinous layer of the regenerating epidermis. As an indication of specificity, the inflammatory cells and fibroblasts within the wound were not influenced by KGF. The results indicate that KGF is unique in its ability to accelerate reepithelialization and dermal regeneration by targeting multiple epithelial elements within the skin. These results suggest that KGF may induce specific epithelial progenitor cell lineages within the skin to proliferate and differentiate, and thus may be a critical determinant of regeneration of skin. Furthermore, these findings illustrate the potential capacity of this system to analyze epithelial differentiation programs and disorders of epidermis, dermal glandular elements, and hair follicles.

1994-01-01

35

Keratinocyte growth factor mRNA expression in periodontal ligament fibroblasts.  

PubMed

Keratinocyte growth factor (KGF) is a fibroblast growth factor which mediates epithelial growth and differentiation. KGF is expressed in subepithelial fibroblasts, but generally not in fibroblasts of deep connective tissue, such as fascia and ligaments. Here we demonstrate that KGF mRNA is expressed in periodontal ligament fibroblasts, and that the expression is increased upon serum stimulation. Fibroblasts from human periodontal ligament, from buccal mucosa, from gingiva, and from skin were established from explants. Alkaline phosphatase activity was used as an indicator of the periodontal nature of fibroblasts. Cells were first cultured in DMEM with 0.5% fetal calf serum (FCS) and then incubated for 8 h, and 72 h in fresh DMEM with 10% FCS. Total RNA was isolated and used for Northern blotting with a P32-labeled KGF cDNA probe. Total RNA from cultured keratinocytes was used as negative controls. KGF mRNA was found in all cultured fibroblasts. Upon addition of 10% FCS to the cell cultures, an increase in KGF mRNA levels was noticed especially after 72 h. Furthermore, RT-PCR analysis of material scraped from the tooth root surface indicated the presence of KGF mRNA even in noncultured periodontal ligament cells. PMID:9469611

Dabelsteen, S; Wandall, H H; Grøn, B; Dabelsteen, E

1997-12-01

36

Keratinocyte growth factor induces proliferation of hepatocytes and epithelial cells throughout the rat gastrointestinal tract.  

PubMed Central

Keratinocyte growth factor (KGF), a member of the fibroblast growth factor (FGF) family, was identified as a specific keratinocyte mitogen after isolation from a lung fibroblast line. Recently, recombinant (r)KGF was found to influence proliferation and differentiation patterns of multiple epithelial cell lineages within skin, lung, and the reproductive tract. In the present study, we designed experiments to identify additional target tissues, and focused on the rat gastrointestinal (GI) system, since a putative receptor, K-sam, was originally identified in a gastric carcinoma. Expression of KGF receptor and KGF mRNA was detected within the entire GI tract, suggesting the gut both synthesized and responded to KGF. Therefore, rKGF was administered to adult rats and was found to induce markedly increased proliferation of epithelial cells from the foregut to the colon, and of hepatocytes, one day after systemic treatment. Daily treatment resulted in the marked selective induction of mucin-producing cell lineages throughout the GI tract in a dose-dependent fashion. Other cell lineages were either unaffected (e.g., Paneth cells), or relatively decreased (e.g., parietal cells, enterocytes) in rKGF-treated rats. The direct effect of rKGF was confirmed by demonstrating markedly increased carcinoembryonic antigen production in a human colon carcinoma cell line, LIM1899. Serum levels of albumin were specifically and significantly elevated after daily treatment. These results demonstrate rKGF can induce epithelial cell activation throughout the GI tract and liver. Further, endogenous KGF may be a normal paracrine mediator of growth within the gut. Images

Housley, R M; Morris, C F; Boyle, W; Ring, B; Biltz, R; Tarpley, J E; Aukerman, S L; Devine, P L; Whitehead, R H; Pierce, G F

1994-01-01

37

Cyclophosphamide Prevents Systemic Keratinocyte Growth Factor-induced Up-Regulation of Surfactant Protein A after Allogeneic Transplant in Mice  

Microsoft Academic Search

We reported that systemic keratinocyte growth factor (KGF) given before bone marrow transplantation (BMT) prevents allogeneic T cell-dependent lung inflammation assessed on Day 7 post-BMT, but the antiinflammatory effects of KGF were impaired in mice in- jected with both T cells and conditioning regimen of cyclophos- phamide (Cy). Intratracheal KGF is known to stimulate the expres- sion of surfactant protein

SHUXIA YANG; ANGELA PANOSKALTSIS-MORTARI; DAVID H. INGBAR; SADIS MATALON; SHA ZHU; ERNESTO R. RESNIK; CATHERINE L. FARRELL; DAVID L. LACEY; BRUCE R. BLAZAR; IMAD Y. HADDAD

2000-01-01

38

Bone Marrow Stem Cells Expressing Keratinocyte Growth Factor via an Inducible Lentivirus Protects against Bleomycin-Induced Pulmonary Fibrosis  

Microsoft Academic Search

Many common diseases of the gas exchange surface of the lung have no specific treatment but cause serious morbidity and mortality. Idiopathic Pulmonary Fibrosis (IPF) is characterized by alveolar epithelial cell injury, interstitial inflammation, fibroblast proliferation and collagen accumulation within the lung parenchyma. Keratinocyte Growth Factor (KGF, also known as FGF-7) is a critical mediator of pulmonary epithelial repair through

Susana Aguilar; Chris J. Scotton; Katrina McNulty; Emma Nye; Gordon Stamp; Geoff Laurent; Dominique Bonnet; Sam M. Janes; Rory Edward Morty

2009-01-01

39

Expression of keratinocyte growth factor and its receptor in human breast cancer.  

PubMed

The level of expression of keratinocyte growth factor (KGF) mRNA has been measured in human breast cell lines, purified populations of epithelial cells, myoepithelial cells and fibroblasts from reduction mammoplasty tissue and a panel of 42 breast cancers and 30 non-malignant human breast tissues using a semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR) procedure. We found similar levels of KGF mRNA in malignant and non-malignant breast tissues. The study of the amount of KGF mRNA in breast cell lines and purified populations of cells revealed that fibroblasts are the predominant source of KGF with malignant and non-malignant epithelial cells containing very low levels of KGF mRNA. We have examined the distribution of fibroblast growth factor receptor (FGFR)-2-IIIb, which is a high-affinity receptor for KGF and find that it is present on malignant and non-malignant epithelial cells. The level of FGFR-2-IIIb present on breast cancer cell lines was sufficient for KGF stimulation of breast cancer cell proliferation. Other members of the fibroblast growth factor family have been either not expressed in the human breast (FGF3, FGF4) or have been found at much reduced levels in breast cancer (FGF1, FGF2) and this is the first member of the family to potentially influence the progression of breast cancer through stimulation of cell division. PMID:9184170

Bansal, G S; Cox, H C; Marsh, S; Gomm, J J; Yiangou, C; Luqmani, Y; Coombes, R C; Johnston, C L

1997-01-01

40

Enhanced expression of keratinocyte growth factor and its receptor correlates with venous invasion in pancreatic cancer.  

PubMed

Keratinocyte growth factor (KGF) and KGF receptor (KGFR) have been implicated in cancer growth as well as tissue development and repair. In this study, we examined whether KGF and KGFR have a role in human pancreatic ductal adenocarcinoma (PDAC). KGFR mRNA was expressed in eight pancreatic cancer cell lines, whereas the KGF mRNA was detected in seven of the cell lines and was absent in MIA PaCa-2 cells. KGFR and KGF immunoreactivity were localized in the cancer cells in 41.5 and 34.0% of patients, respectively. There was a significant correlation between KGFR or KGF immunoreactivity and venous invasion and a significant correlation between the presence of both markers and venous invasion, vascular endothelial growth factor (VEGF)-A expression, and poor prognosis. Exogenous KGF increased VEGF-A expression and release in MIA PaCa-2 cells, and PANC-1 cells stably transfected to overexpress KGF-exhibited increased VEGF-A expression. Moreover, short hairpin-KGFR transfection in MIA PaCa-2 cells reduced the stimulatory effect of exogenous KGF on VEGF-A expression. Short hairpin-KGF transfection in KLM-1 cells reduced VEGF-A expression in the cells. KGFR and KGF may act to promote venous invasion and tumor angiogenesis in PDAC, raising the possibility that they may serve as novel therapeutic targets in anti-angiogenic strategies in PDAC. PMID:17525264

Cho, Kazumitsu; Ishiwata, Toshiyuki; Uchida, Eiji; Nakazawa, Nando; Korc, Murray; Naito, Zenya; Tajiri, Takashi

2007-06-01

41

Keratinocyte growth factor induces matrix metalloproteinase-9 expression and correlates with venous invasion in pancreatic cancer  

PubMed Central

Keratinocyte growth factor (KGF), also known as fibroblast growth factor-7, and KGF receptor (KGFR) play important roles in the growth of epithelial cells and are overexpressed in a variety of malignant epithelial tumors, including pancreatic ductal adenocarcinoma (PDAC). We previously reported that co-expression of KGF and KGFR in PDAC is associated with venous invasion, enhanced vascular endothelial growth factor A expression and poor prognosis. Matrix metalloproteinase-9 (MMP-9) is known to participate in the degradation of type IV collagen, which is a primary component of extracellular matrices in the vascular basement membrane. In the present study, we examined the expression and roles of KGF, KGFR and MMP-9 in human PDAC cell lines and tissues. Quantitative real-time polymerase chain reaction analysis demonstrated the expression of MMP-9 mRNA in all eight PDAC cell lines. KGF, KGFR and MMP-9 were, respectively, expressed in 27 (43%), 23 (37%) and 35 (56%) of 63 patients. Each expression of KGF, KGFR or MMP-9 correlated positively with venous invasion. Furthermore, expression of KGF or MMP-9 correlated positively with liver metastasis. KGF-positive cases exhibited shorter survival than KGF-negative cases, while KGFR and MMP-9 expression were unrelated to prognosis. Administration of recombinant human KGF increased MMP-9 expression in PDAC cells, while transient transfection with short hairpin RNAs targeting KGF transcripts reduced MMP-9 expression in PDAC cells. Moreover, recombinant human KGF significantly enhanced migration and invasion of PDAC cells. These findings suggest that KGF and KGFR promote venous invasion via MMP-9 in PDAC, and closely correlate with liver metastasis. The KGF/KGFR pathway may be a critical therapeutic target for PDAC metastasis.

CHO, KAZUMITSU; MATSUDA, YOKO; UEDA, JUNJI; UCHIDA, EIJI; NAITO, ZENYA; ISHIWATA, TOSHIYUKI

2012-01-01

42

Keratinocyte growth factor gene transduction ameliorates acute lung injury and mortality in mice.  

PubMed

At present there is no known effective pharmacological therapy for acute lung injury (ALI). Because keratinocyte growth factor (KGF) promotes epithelial cell growth, intratracheal administration of KGF has the possibility of restoring lung tissue integrity in injured lungs and improving patient outcomes. However, treatment using recombinant KGF protein is limited by its short effective duration. Thus, we investigated the effectiveness of intratracheal KGF gene transduction using adenoviral vector in ALI. We constructed an adenoviral vector expressing mouse KGF (mKGF), and 1.0 x 10(9 ) plaque-forming units of mKGF cDNA-expressing (Ad-KGF) and control (Ad-1w1) adenoviral vector was intratracheally instilled, using a MicroSprayer, into anesthetized BALB/c mice. Three days later, the mice were exposed to >90% oxygen for 72 hr, and the effect of KGF on hyperoxia-induced lung injury was examined. In the Ad-KGF group, KGF was strongly expressed in the airway epithelial cells, while peribronchiolar and alveolar inflammation caused by adenoviral vector instillation was minimal. The KGF overexpression not only induced proliferation of surfactant protein C-positive cuboidal cells, especially in the terminal bronchiolar and alveolar walls, but also prevented lung injury including intraalveolar exudation/hemorrhage, albumin permeability increase, and pulmonary edema. The arterial oxygen tension and the survival rate were significantly higher in the KGF-transfected group. These findings suggest that KGF gene transduction into the airway epithelium is a promising potential treatment for ALI. PMID:17328680

Baba, Yasuko; Yazawa, Takuya; Kanegae, Yumi; Sakamoto, Seiko; Saito, Izumu; Morimura, Naoto; Goto, Takahisa; Yamada, Yoshitsugu; Kurahashi, Kiyoyasu

2007-02-01

43

Expression of keratinocyte growth factor receptor (KGFR/FGFR2 IIIb) in human uterine cervical cancer.  

PubMed

Keratinocyte growth factor receptor (KGFR), also known as FGFR2 IIIb, is a splice variant of FGFR-2. KGFR is expressed in many types of epithelial cell and is activated with four known ligands [FGF-1, FGF-3, FGF-7 (also known as KGF) and FGF-10] that are predominantly synthesized by mesenchymal cells. KGFR is highly expressed in the late-proliferative phase of a normal endometrium and in endometrial adenocarcinoma. In the present study, we attempted to determine the expression and localization of KGFR in human cervical cancer cell lines and cervical cancer tissues. The KGFR protein was detected in CaSki and HeLa cells, but not in ME-180 cells of cervical cancer cell lines. In non-cancer cervical tissues, KGFR immunoreactivity was weakly expressed in the surface of squamous epithelial cells and vascular smooth muscle cells. Immunohistochemically, the KGFR protein was detected in squamous cell carcinoma in 36 of 42 (86%) cervical cancer patients. In cervical cancer tissues, KGFR was detected in 17 of 18 (94%) of patients with the keratinizing type and 19 of 24 (79%) of patients with the non-keratinizing type of cervical cancer. Furthermore, KGFR was prominently localized in proliferating reserve cells and squamous metaplastic reserve cells adjacent to cancer cells. In contrast, KGFR was not detected in cervical ductal cells in cancer or non-cancer cervical tissues. These findings may indicate that KGFR mediates the growth and differentiation of reserve cells and squamous cell carcinoma in the cervix. PMID:15069536

Kurban, Gulnar; Ishiwata, Toshiyuki; Kudo, Mitsuhiro; Yokoyama, Munehiro; Sugisaki, Yuichi; Naito, Zenya

2004-05-01

44

Stabilization of recombinant human keratinocyte growth factor by osmolytes and salts.  

PubMed

Keratinocyte growth factor (KGF) has limited stability in aqueous media, as it undergoes denaturation followed by aggregation at 37 degrees C. Heparin and anionic polymers have been shown to increase the denaturation temperatures and extend the half-life of the monomeric, native form of KGF during storage. These polymers, however, bind more than one protein molecule with high affinity, and such tight complex formation may cause problems for clinical use. In this study, we have tested low molecular weight additives, such as osmolytes and salts, for their effects on the stability of KGF against thermal denaturation and high-temperature storage. Salts such as NaCl, sodium phosphate, ammonium sulfate, and sodium citrate were highly effective in increasing both the denaturation temperature and storage stability. The fact that the same additives stabilize KGF against both stresses is consistent with the idea that the storage stability is determined by denaturation followed by aggregation. Among the osmolytes tested, N,N'-dimethylglycine, trehalose, and sucrose were also effective stabilizers. However, quantitative comparison of the osmolytes tested indicated that their effectiveness on the thermal denaturation and the storage stability is not exactly parallel, suggesting that other factors also contribute to the storage stability. PMID:8901081

Chen, B L; Arakawa, T

1996-04-01

45

Clinical significance of keratinocyte growth factor and K-sam gene expression in gastric cancer.  

PubMed

Although gastric cancer is increasingly being detected at an early stage of development, diffuse growth?type malignant tumors, such as scirrhous gastric cancer, are usually at an advanced stage at the time of diagnosis, resulting in poor treatment outcomes. The aim of this study was to determine whether the K-sam gene and keratinocyte growth factor (KGF) expression may be used to identify malignant tumors with a poor prognosis. K-sam and KGF expression was retrospectively evaluated in samples from 86 patients with early and advanced gastric cancer according to type, by examining serum levels and using immunohistochemical staining. The associations with clinicopathological characteristics and survival were also examined. The mean serum KGF levels were 11.191±3.808 pg/ml in early stage and 10.715±3.4991 pg/ml in advanced gastric cancer patients. KGF levels were significantly higher in types 4 and 5 (14.498±3.812 pg/ml, n=6) compared with types 1, 2 and 3 (10.747±3.571 pg/ml, n=80; P=0.028). Stage classification was identified as the only significant factor which determined overall survival. Patients with KGF-positive tumors had significantly higher serum KGF levels compared with those who had KGF-negative tumors. Patients with K-sam?positive tumors had significantly higher KGF levels compared with those who had K-sam-negative tumors. Pathological KGF expression was not significantly correlated with the degree of differentiation; however, there was a positive correlation between high K-sam expression in scirrhous gastric tumors and serum KGF levels. The present study revealed that high serum KGF levels are a risk factor for diffuse infiltrative gastric cancer and may provide a simple method of identifying patients with a poor prognosis among previously diagnosed preoperative gastric cancer patients. PMID:23545898

Tani, Hideki; Saito, Noboru; Kobayashi, Makio; Kameoka, Shingo

2013-03-27

46

Clinical significance of keratinocyte growth factor and K-sam gene expression in gastric cancer  

PubMed Central

Although gastric cancer is increasingly being detected at an early stage of development, diffuse growth-type malignant tumors, such as scirrhous gastric cancer, are usually at an advanced stage at the time of diagnosis, resulting in poor treatment outcomes. The aim of this study was to determine whether the K-sam gene and keratinocyte growth factor (KGF) expression may be used to identify malignant tumors with a poor prognosis. K-sam and KGF expression was retrospectively evaluated in samples from 86 patients with early and advanced gastric cancer according to type, by examining serum levels and using immunohistochemical staining. The associations with clinicopathological characteristics and survival were also examined. The mean serum KGF levels were 11.191±3.808 pg/ml in early stage and 10.715±3.4991 pg/ml in advanced gastric cancer patients. KGF levels were significantly higher in types 4 and 5 (14.498±3.812 pg/ml, n=6) compared with types 1, 2 and 3 (10.747±3.571 pg/ml, n=80; P=0.028). Stage classification was identified as the only significant factor which determined overall survival. Patients with KGF-positive tumors had significantly higher serum KGF levels compared with those who had KGF-negative tumors. Patients with K-sam-positive tumors had significantly higher KGF levels compared with those who had K-sam-negative tumors. Pathological KGF expression was not significantly correlated with the degree of differentiation; however, there was a positive correlation between high K-sam expression in scirrhous gastric tumors and serum KGF levels. The present study revealed that high serum KGF levels are a risk factor for diffuse infiltrative gastric cancer and may provide a simple method of identifying patients with a poor prognosis among previously diagnosed preoperative gastric cancer patients.

TANI, HIDEKI; SAITO, NOBORU; KOBAYASHI, MAKIO; KAMEOKA, SHINGO

2013-01-01

47

Transforming growth factor beta 1 suppression of c-myc gene transcription: role in inhibition of keratinocyte proliferation.  

PubMed Central

Transforming growth factor beta 1 (TGF-beta 1) is a potent growth inhibitor for many cell types, including most epithelial cells. However, the mechanism of growth inhibition is unknown. In skin keratinocytes, TGF-beta 1 has been shown to inhibit growth and to rapidly reduce c-myc expression. It has been demonstrated that protein synthesis is required for TGF-beta 1 regulation of c-myc in keratinocytes. Here we present evidence that treatment of mouse BALB/MK keratinocyte cells with either antisense c-myc oligonucleotides or TGF-beta 1 inhibited cell entry into S phase. These results suggest that TGF-beta inhibition of c-myc expression may be essential for growth inhibition by TGF-beta 1. The block in c-myc expression by TGF-beta 1 occurred at the level of transcriptional initiation. Studies with a series of 5' deletion c-myc/chloramphenicol acetyltransferase constructs indicated that a cis regulatory element(s), which resides between positions -100 and +71 relative to P1 transcription start site, is responsible for the TGF-beta 1 responsiveness. Based on these data, it is proposed that the mechanism of TGF-beta 1 growth inhibition involves synthesis or modification of a protein that may interact with a specific element(s) in the 5' regulatory region of the c-myc gene, resulting in inhibition of transcriptional initiation. Images

Pietenpol, J A; Holt, J T; Stein, R W; Moses, H L

1990-01-01

48

Keratinocyte growth factor-induced hyperplasia of rat alveolar type II cells in vivo is resolved by differentiation into type I cells and by apoptosis  

Microsoft Academic Search

Keratinocyte growth factor-induced hyperplasia of rat alveolar type II cells in vivo is re- solved by differentiation into type I cells and by apoptosis. H. Fehrenbach, M. Kasper, T. Tschernig, T. Pan, D. Schuh, J.M. Shannon, M. Muller, R.J. Mason.#ERS Journals Ltd 1999. ABSTRACT: Keratinocyte growth factor (KGF) is a potent mitogen of alveolar epi- thelial type II cells (AEII).

H. Fehrenbach; M. Kasper; T. Tschernig; T. Pan; D. Schuh; J. M. Shannon; M. Müller; R. J. Mason

1999-01-01

49

Recent advances in the epidermal growth factor receptor/ligand system biology on skin homeostasis and keratinocyte stem cell regulation.  

PubMed

The epidermal growth factor (EGF) receptor/ligand system stimulates multiple pathways of signal transduction, and is activated by various extracellular stimuli and inter-receptor crosstalk signaling. Aberrant activation of EGF receptor (EGFR) signaling is found in many tumor cells, and humanized neutralizing antibodies and synthetic small compounds against EGFR are in clinical use today. However, these drugs are known to cause a variety of skin toxicities such as inflammatory rash, skin dryness, and hair abnormalities. These side effects demonstrate the multiple EGFR-dependent homeostatic functions in human skin. The epidermis and hair follicles are self-renewing tissues, and keratinocyte stem cells are crucial for maintaining these homeostasis. A variety of molecules associated with the EGF receptor/ligand system are involved in epidermal homeostasis and hair follicle development, and the modulation of EGFR signaling impacts the behavior of keratinocyte stem cells. Understanding the roles of the EGF receptor/ligand system in skin homeostasis is an emerging issue in dermatology to improve the current therapy for skin disorders, and the EGFR inhibitor-associated skin toxicities. Besides, controlling of keratinocyte stem cells by modulating the EGF receptor/ligand system assures advances in regenerative medicine of the skin. We present an overview of the recent progress in the field of the EGF receptor/ligand system on skin homeostasis and regulation of keratinocyte stem cells. PMID:23819985

Nanba, Daisuke; Toki, Fujio; Barrandon, Yann; Higashiyama, Shigeki

2013-06-13

50

Selective inhibition of growth-related gene expression in murine keratinocytes by transforming growth factor beta.  

PubMed Central

Transforming growth factor beta (TGF beta) is a potent inhibitor of epithelial cell proliferation. A nontumorigenic epidermal growth factor (EGF)-dependent epithelial cell line, BALB/MK, is reversibly growth arrested by TGF beta. TGF beta will also abrogate EGF-stimulated mitogenesis of quiescent BALB/MK cells. Increased levels of calcium (greater than 1.0 mM) will induce differentiation in BALB/MK cells; in contrast, TGF beta-mediated growth inhibition does not result in induction of terminal differentiation. In the present study, the effects of TGF beta and calcium on growth factor-inducible gene expression were examined. TGF beta markedly decreased c-myc and KC gene expression in rapidly growing BALB/MK cells and reduced the EGF induction of c-myc and KC in a quiescent population of cells. TGF beta exerted its control over c-myc expression at a posttranscriptional level, and this inhibitory effect was dependent on protein synthesis. TGF beta had no effect on c-fos gene expression, whereas 1.5 mM calcium attenuated EGF-induced c-fos expression in quiescent cells. Expression of beta-actin, however, was slightly increased in both rapidly growing and EGF-restimulated quiescent BALB/MK cells treated with TGF beta. Thus, in this system, TGF beta selectively reduced expression of certain genes associated with cell proliferation (c-myc and KC), and at least part of the TGF beta effect was at a posttranscriptional level. Images

Coffey, R J; Bascom, C C; Sipes, N J; Graves-Deal, R; Weissman, B E; Moses, H L

1988-01-01

51

Keratinocyte growth factor stimulates growth of MIA PaCa-2 cells through extracellular signal-regulated kinase phosphorylation.  

PubMed

Keratinocyte growth factor (KGF), also known as fibroblast growth factor-7, is mainly synthesized by mesenchymal cells. KGF modulates proliferation, differentiation, migration and adhesion to extracellular matrices of epithelial cells that specifically express the KGF receptor (KGFR). We previously reported that KGF is expressed in cancer cells and adjacent stromal fibroblasts in human pancreatic cancer tissues. Furthermore, KGF is thought to stimulate the growth of certain pancreatic cancer cell lines. The aim of the present study was to examine whether the mitogen-activated protein kinase (MAPK) pathway contributes to exogenous KGF-induced pancreatic cancer cell growth. Recombinant human KGF (rhKGF) was administered to MIA PaCa-2 cells, which expressed KGFR and negligible levels of KGF. Cell growth rates in MIA PaCa-2 cells were significantly increased in a dose-dependent manner following the addition of rhKGF. In the MAPK pathway, phosphorylation of extracellular signal-regulated kinase (ERK) in MIA PaCa-2 cells was increased in a dose-dependent manner, and phosphorylation of p38 was slightly increased following the administration of 100 ng/ml rhKGF. In contrast, JNK was not phosphorylated following the addition of rhKGF in MIA PaCa-2 cells. U0126, a specific inhibitor of ERK activation, decreased the rhKGF-induced phosphorylation of ERK and the growth rates of MIA PaCa-2 cells. These findings indicated that phosphorylation of the ERK signaling pathway plays a significant role in exogenous KGF-induced pancreatic cancer cell growth. PMID:22740901

Yamamoto, Tetsushi; Matsuda, Yoko; Kawahara, Kiyoko; Naito, Zenya; Ishiwata, Toshiyuki

2011-10-31

52

Keratinocyte growth factor modulates alveolar epithelial cell phenotype in vitro: expression of aquaporin 5.  

PubMed

We investigated the role of keratinocyte growth factor (KGF) in regulation of alveolar epithelial cell (AEC) phenotype in vitro. Effects of KGF on cell morphology, expression of surfactant apoproteins A, B, and C (SP-A, -B, and -C), and expression of aquaporin 5 (AQP5), a water channel present in situ on the apical surface of alveolar type I (AT1) cells but not expressed in alveolar type II (AT2) cells, were evaluated in AECs grown in primary culture. Observations were made on AEC monolayers grown in serum-free medium without KGF (control) or grown continuously in the presence of KGF (10 ng/ml) from either Day 0 (i.e., the time of plating) or Day 4 or 6 through Day 8 in culture. AECs monolayers express AQP5 only on their apical surfaces as determined by cell surface biotinylation studies. Control AECs grown in the absence of KGF through Day 8 express increasing levels of AQP5, consistent with transition toward the AT1 cell phenotype. Exposure of AECs to KGF from Day 0 results in decreased AQP5 expression, retention of a cuboidal morphology, and greater numbers of lamellar bodies relative to control on Day 8 in culture. AECs treated with KGF from Day 4 or 6 exhibit a decrease in AQP5 expression through subsequent days in culture, as well as an increase in expression of surfactant apoproteins. These data, showing that KGF both prevents and reverses the increase in AQP5 (and decrease in surfactant apoprotein) expression that accompanies progression of the AT2 toward the AT1 cell phenotype, support the concepts that transdifferentiation between AT2 and AT1 cell phenotypes is at least partially reversible and that KGF may play a major role in modulating AEC phenotype. PMID:9533944

Borok, Z; Lubman, R L; Danto, S I; Zhang, X L; Zabski, S M; King, L S; Lee, D M; Agre, P; Crandall, E D

1998-04-01

53

Keratinocyte growth factor enhances barrier function without altering claudin expression in primary alveolar epithelial cells.  

PubMed

Keratinocyte growth factor (KGF) has efficacy in several experimental models of lung injury; however, the mechanisms underlying KGF's protective effect remain incompletely understood. This study was undertaken to determine whether KGF augments barrier function in primary rat alveolar epithelial cells grown in culture, specifically whether KGF alters tight junction function via claudin expression. KGF significantly increased alveolar epithelial barrier function in culture as assessed by transepithelial electrical resistance (TER) and paracellular permeability. Fluorescence-activated cell sorting of freshly isolated type 1 (AT1) and type 2 (AT2) cells followed by quantitative real-time RT-PCR revealed that more than 97% of claudin mRNA transcripts in these cells were for claudins-3, -4, and -18. Using cultured AT2 cells, we then examined the effect of KGF on the protein levels of the claudins with the highest mRNA levels: -3, -4, -5, -7, -12, -15, and -18. KGF did not alter the levels of any of the claudins tested, nor of zona occludens-1 (ZO-1) or occludin. Moreover, localization of claudins-3, -4, -18, and ZO-1 was unchanged. KGF did induce a marked increase in the apical perijunctional F-actin ring. Actin depolymerization with cytochalasin D blocked the KGF-mediated increase in TER without significantly changing TER in control cells. Together, these data support a novel mechanism by which KGF enhances alveolar barrier function, modulation of the actin cytoskeleton. In addition, these data demonstrate the complete claudin expression profile for AT1 and AT2 cells and indicate that claudins-3, -4, and -18 are the primary claudins expressed in these cell types. PMID:20833776

LaFemina, Michael J; Rokkam, Deepti; Chandrasena, Anita; Pan, Jue; Bajaj, Anisha; Johnson, Meshell; Frank, James A

2010-09-10

54

Keratinocyte growth factor enhances barrier function without altering claudin expression in primary alveolar epithelial cells  

PubMed Central

Keratinocyte growth factor (KGF) has efficacy in several experimental models of lung injury; however, the mechanisms underlying KGF's protective effect remain incompletely understood. This study was undertaken to determine whether KGF augments barrier function in primary rat alveolar epithelial cells grown in culture, specifically whether KGF alters tight junction function via claudin expression. KGF significantly increased alveolar epithelial barrier function in culture as assessed by transepithelial electrical resistance (TER) and paracellular permeability. Fluorescence-activated cell sorting of freshly isolated type 1 (AT1) and type 2 (AT2) cells followed by quantitative real-time RT-PCR revealed that more than 97% of claudin mRNA transcripts in these cells were for claudins-3, -4, and -18. Using cultured AT2 cells, we then examined the effect of KGF on the protein levels of the claudins with the highest mRNA levels: -3, -4, -5, -7, -12, -15, and -18. KGF did not alter the levels of any of the claudins tested, nor of zona occludens-1 (ZO-1) or occludin. Moreover, localization of claudins-3, -4, -18, and ZO-1 was unchanged. KGF did induce a marked increase in the apical perijunctional F-actin ring. Actin depolymerization with cytochalasin D blocked the KGF-mediated increase in TER without significantly changing TER in control cells. Together, these data support a novel mechanism by which KGF enhances alveolar barrier function, modulation of the actin cytoskeleton. In addition, these data demonstrate the complete claudin expression profile for AT1 and AT2 cells and indicate that claudins-3, -4, and -18 are the primary claudins expressed in these cell types.

LaFemina, Michael J.; Rokkam, Deepti; Chandrasena, Anita; Pan, Jue; Bajaj, Anisha; Johnson, Meshell

2010-01-01

55

Keratinocyte growth factor-induced proliferation of rat airway epithelium is restricted to Clara cells in vivo  

Microsoft Academic Search

ABSTRACT: Keratinocyte growth,factor (KGF) is a potent mitogen,of pulmonary bronchial and alveolar epithelial cells. However, it is unclear which type(s) of airway epithelial cells (AEC) proliferate(s) in response to KGF. AEC proliferation was,induced in rats by either endobronchial,instillation of 5 mg recombinant,human,(rHu) KGF per kg body,weight or by adenoviral transfer of the human,KGF gene (Ad5-HuKGF). Alterations in terminal airway AEC

H. Fehrenbach; A. Fehrenbach; T. Pan; M. Kasperz; R. J. Mason

2002-01-01

56

Pancreatic Expression of Keratinocyte Growth Factor Leads to Differentiation of Islet Hepatocytes and Proliferation of Duct Cells  

PubMed Central

Keratinocyte growth factor, (KGF), a member of the fibroblast growth factor (FGF) family, is involved in wound healing. It also promotes the differentiation of many epithelial tissues and proliferation of epithelial cells as well as pancreatic duct cells. Additionally, many members of the highly homologous FGF family (including KGF), influence both growth and cellular morphology in the developing embryo. We have previously observed elevated levels of KGF in our interferon-? transgenic mouse model of pancreatic regeneration. To understand the role of KGF in pancreatic differentiation, we generated insulin promoter-regulated KGF transgenic mice. Remarkably, we have found that ectopic KGF expression resulted in the emergence of hepatocytes within the islets of Langerhans in the pancreas. Additionally, significant intra-islet duct cell proliferation in the pancreata of transgenic KGF mice was observed. The unexpected appearance of hepatocytes and proliferation of intra-islet duct cells in the pancreata of these mice evidently stemmed directly from local exposure to KGF.

Krakowski, Michelle L.; Kritzik, Marcie R.; Jones, Ellene M.; Krahl, Troy; Lee, Jae; Arnush, Marc; Gu, Danling; Sarvetnick, Nora

1999-01-01

57

Modulation of keratinocyte motility. Correlation with production of extracellular matrix molecules in response to growth promoting and antiproliferative factors.  

PubMed Central

Normal human epidermal keratinocytes (KC) grown under conditions that maintain the undifferentiated state are highly motile. Migration of these cells as measured in two different assays (migration out of an agarose drop explant, and into micropore filters in a modified Boyden chamber), is stimulated by fibronectin (FN) and to a lesser extent by thrombospondin (TSP). In contrast, laminin (LN) inhibits KC migration. Cultivation of the cells for 1 day under conditions that induce differentiation (ie, in the presence of 1.4 mM Ca2+) suppresses KC motility. A number of soluble growth modulating polypeptide factors also influence KC migration. Transforming growth factor-beta (TGF-beta) and epidermal growth factor (EGF) stimulate KC motility. These factors simultaneously induce KC production of FN and a significant portion of the stimulated motility can be inhibited with antibodies to FN. EGF and somatomedin-C (SM-C), but not TGF-beta, also stimulate TSP production while EGF and SM-C (but not TGF-beta) induce KC proliferation. In contrast to these factors, interferon-gamma (INF-gamma) inhibits KC production of both FN and TSP and concomitantly inhibits both motility and proliferation. These data suggest that KC properties essential for normal wound healing (ie, motility and proliferation) are regulated by both extracellular matrix molecules and soluble peptide factors. Finally, these effects of various growth promoting and antiproliferative factors on KCs may, in part, be mediated through alteration in the endogenous production of extracellular matrix molecules by KCs. Images Figure 2

Nickoloff, B. J.; Mitra, R. S.; Riser, B. L.; Dixit, V. M.; Varani, J.

1988-01-01

58

Further Characterization of the Keratinocyte Somatomedin-C\\/Insulin-like Growth Factor I (SMC\\/IGF-I) Receptor and the Biological Responsiveness of Cultured Keratinocytes to SMC\\/IGF-I  

Microsoft Academic Search

Somatomedin-C\\/insulin-like growth factor I (SM-C\\/IGF-I) binds to both cultured keratinocytes trypsinized to single-cell suspensions and fresh epidermal sheets derived from 1 M NaBr-treated 6-mm punch biopsies. A gradual increase of 1–4% in specific binding of SM-C\\/IGF-I to fresh epidermal sheets was observed during a 5-hour incubation period at 15°C. The human keratinocyte SM-C\\/IGF-I receptor was isolated by polyacrylamide gel electrophoresis

Brian J. Nickoloff; Pratima Misra; Vera B. Morhenn; Raymond L. Hintz; Ron G. Rosenfeld

1988-01-01

59

Profiling and metaanalysis of epidermal keratinocytes responses to epidermal growth factor  

PubMed Central

Background One challenge of systems biology is the integration of new data into the preexisting, and then re-interpretation of the integrated data. Here we use readily available metaanalysis computational methods to integrate new data on the transcriptomic effects of EGF in primary human epidermal keratinocytes with preexisting transcriptomics data in keratinocytes and in EGF-treated non-epidermal cell types. Results We find that EGF promotes keratinocyte proliferation, attachment and motility and, surprisingly, induces DUSPs that attenuate the EGF signal. Our metaanalysis identified overlapping effects of EGF with those of IL-1 and IFN?, activators of keratinocyte in inflammation and wound healing. We also identified the genes and pathways suppressed by EGF but induced by agents promoting epidermal differentiation. Metaanalysis comparison with the EGF effects in other cell types identified extensive similarities between responses in keratinocytes and in other epithelial cell types, but specific differences with the EGF effects in endothelial cells, and in transformed, oncogenic epithelial cell lines. Conclusions This work defines the specific transcriptional effects of EGF on human epidermal keratinocytes. Our approach can serve as a suitable paradigm for integration of new omics data into preexisting databases and re-analysis of the integrated data sets.

2013-01-01

60

Synergistic Effects of Epidermal Growth Factor (EGF) and Insulin-Like Growth Factor I\\/Somatomedin C (IGF-I) on Keratinocyte Proliferation May Be Mediated by IGF-I Transmodulation of the EGF Receptor  

Microsoft Academic Search

The epidermal growth factor (EGF) receptor pathway is an important mediator of keratinocyte growth in vitro and both receptor and ligand components of this pathway are abnormally expressed in hyperproliferative epidermis. The purpose of this study was to examine interactions between the EGF receptor pathway and the insulin-like growth factor I\\/somatomedin C (IGF-I) receptor pathway in modulating the growth of

Jeffrey F. Krane; Daniel P. Murphy; D. Martin Carter; James G. Krueger

1991-01-01

61

Keratinocyte growth factor in acute lung injury to reduce pulmonary dysfunction - a randomised placebo-controlled trial (KARE): study protocol  

PubMed Central

Background Acute lung injury is a common, devastating clinical syndrome associated with substantial mortality and morbidity with currently no proven therapeutic interventional strategy to improve patient outcomes. The objectives of this study are to test the potential therapeutic effects of keratinocyte growth factor for patients with acute lung injury on oxygenation and biological indicators of acute inflammation, lung epithelial and endothelial function, protease:antiprotease balance, and lung extracellular matrix degradation and turnover. Methods/design This will be a prospective, randomised, double-blind, allocation-concealed, placebo-controlled, phase 2, multicentre trial. Randomisation will be stratified by presence of severe sepsis requiring vasopressors. Patients in an ICU fulfilling the American–European Consensus Conference Definition of acute lung injury will be randomised in a 1:1 ratio to receive an intravenous bolus of either keratinocyte growth factor (palifermin, 60 ?g/kg) or placebo (0.9% sodium chloride solution) daily for a maximum of 6 days. The primary endpoint of this clinical study is to evaluate the efficacy of palifermin to improve the oxygenation index at day 7 or the last available oxygenation index prior to patient discontinuation from the study. A formal statistical analysis plan has been constructed. Analyses will be carried out on an intention-to-treat basis. A single analysis is planned at the end of the trial. P = 0.05 will be considered statistically significant and all tests will be two-sided. For continuously distributed outcomes, differences between groups will be tested using independent-sample t tests, analysis of variance and analysis of covariance with transformation of variables to normality or nonparametric equivalents. The trial will be reported in line with the Consolidated Standards of Reporting Trials (Consort 2010 guidelines). Trial registration http://ISRCTN95690673

2013-01-01

62

Myofibroblast keratinocyte growth factor reduces tight junctional integrity and increases claudin-2 levels in polarized Caco-2 cells.  

PubMed

The colonic epithelium is composed of a polarized monolayer sheathed by a layer of pericryptal myofibroblasts (PCMFs). We mimicked these cellular compartments in vitro to assess the effects of paracrine-acting PCMF-derived factors on tight junction (TJ) integrity, as measured by transepithelial electrical resistance (TER). Coculture with 18Co PCMFs, or basolateral administration of 18Co conditioned medium, significantly reduced TER of polarized Caco-2 cells. Among candidate paracrine factors, only keratinocyte growth factor (KGF) reduced Caco-2 TER; basolateral KGF treatment led to time- and concentration-dependent increases in claudin-2 levels. We also demonstrate that amphiregulin (AREG), produced largely by Caco-2 cells, increased claudin-2 levels, leading to epidermal growth factor receptor-mediated TER reduction. We propose that colonic epithelial TJ integrity can be modulated by paracrine KGF and autocrine AREG through increased claudin-2 levels. KGF-regulated claudin-2 induction may have implications for inflammatory bowel disease, where both KGF and claudin-2 are upregulated. PMID:22946653

Kim, Tae Il; Poulin, Emily J; Blask, Elliot; Bukhalid, Raghida; Whitehead, Robert H; Franklin, Jeffrey L; Coffey, Robert J

2012-09-05

63

Myofibroblast keratinocyte growth factor reduces tight junctional integrity and increases claudin-2 levels in polarized Caco-2 cells  

PubMed Central

The colonic epithelium is composed of a polarized monolayer sheathed by a layer of pericryptal myofibroblasts (PCMFs). We mimicked these cellular compartments in vitro to assess the effects of paracrine-acting PCMF-derived factors on tight junction (TJ) integrity, as measured by transepithelial electrical resistance (TER). Co-culture with 18Co PCMFs, or basolateral administration of 18Co conditioned medium (CM), significantly reduced TER of polarized Caco-2 cells. Amongst candidate paracrine factors, only keratinocyte growth factor (KGF) reduced Caco-2 TER; basolateral KGF treatment led to time- and concentration-dependent increases in claudin-2 levels. We also demonstrate amphiregulin (AREG), produced largely by Caco-2 cells, increased claudin-2 levels, leading to epidermal growth factor receptor-mediated TER reduction. We propose that colonic epithelial TJ integrity can be modulated by paracrine KGF and autocrine AREG through increased claudin-2 levels. KGF-regulated claudin-2 induction may have implications for inflammatory bowel disease, where both KGF and claudin-2 are upregulated.

Kim, Tae Il; Poulin, Emily J.; Blask, Elliot; Bukhalid, Raghida; Whitehead, Robert H.; Franklin, Jeffrey L.; Coffey, Robert J.

2013-01-01

64

Expression and modulation of nerve growth factor in murine keratinocytes (PAM 212)  

Microsoft Academic Search

Nerve growth factor (NGF) is a polypeptide that is required for normal development and maintenance of the sympathetic and sensory nervous systems. Skin has been shown to contain relatively high amounts of NGF, which is in keeping with the finding that the quantity of NGF in a tissue is proportional to the extent of sympathetic innervation of that organ. Since

V. A. Tron; M. D. Coughlin; D. E. Jang; J. Stanisz; D. N. Sauder

1990-01-01

65

Transactivation of involucrin, a marker of differentiation in keratinocytes, by lens epithelium-derived growth factor (LEDGF).  

PubMed

Human involucrin (hINV), first appears in the cytosol of keratinocytes and ultimately cross-linked to membrane proteins via transglutaminase and forms a protective barrier as an insoluble envelope beneath the plasma membrane. Although the function and evolution of involucrin is known, the regulation of its gene expression is not well understood. An analysis of the hINV gene sequence, upstream of the transcription start site (-534 to +1 nt) revealed the presence of potential sites for binding of lens epithelium-derived growth factor (LEDGF); stress response element (STRE; A/TGGGGA/T) and heat shock element (HSE; nGAAn). We reported earlier that LEDGF activates stress-associated genes by binding to these elements and elevates cellular resistance to various stresses. Here, gel-shift and super-shift assays confirm the binding of LEDGF to the DNA fragments containing HSEs and STREs that are present in the involucrin gene promoter. Furthermore, hINV promoter linked to CAT reporter gene, cotransfected in human corneal simian virus 40-transformed keratinocytes (HCK), was transactivated by LEDGF significantly. In contrast, the activity of hINV promoter bearing mutations at the WT1 (containing HSE and STRE), WT2 (containing STRE) and WT3 (containing STRE) binding sites was diminished. In addition, in HCK cell over-expressing LEDGF, the levels of hINV mRNA and hINV protein are increased by four to five-fold. LEDGF is inducible to oxidants. Cells treated with 12-O-tetradecanoyl-phorbol-13-acetate (TPA), known to stimulate production of H(2)O(2), showed higher levels of LEDGF mRNA. Furthermore, our immunohistochemical studies revealed that hINV protein is found in the cytoplasm of HCK cells over-expressing LEDGF, but not detectable in the normal HCK cells or HCK cells transfected with vector. This regulation appears to be physiologically important, as over-expression of HCK with LEDGF increases the expression of the endogenous hINV gene and may provide new insight to understand the molecular mechanism of transcriptional regulation of this gene. LEDGF may play an important role in establishing an important barrier in corneal keratinocytes by maintaining epidermal turn-over rate, and protecting HCKs against stress. PMID:12126624

Kubo, E; Fatma, N; Sharma, P; Shinohara, T; Chylack, L T; Akagi, Y; Singh, D P

2002-07-26

66

Insulin-Like Growth Factor 1 Receptor Signaling Regulates Skin Development and Inhibits Skin Keratinocyte Differentiation  

Microsoft Academic Search

The insulin-like growth factor 1 receptor (IGF-1R) is a multifunctional receptor that mediates signals for cell proliferation, differentiation, and survival. Genetic experiments showed that IGF-1R inactivation in skin results in a disrupted epidermis. However, because IGF-1R-null mice die at birth, it is difficult to study the effects of IGF-1R on skin. By using a combined approach of conditional gene ablation

Marianna Sadagurski; Shoshana Yakar; Galina Weingarten; Martin Holzenberger; Christopher J. Rhodes; Dirk Breitkreutz; Derek LeRoith; Efrat Wertheimer

2006-01-01

67

Keratinocyte Growth Factor Improves Epithelial Structure and Function in a Mouse Model of Intestinal Ischemia/Reperfusion  

PubMed Central

Background Intestinal ischemia/reperfusion (I/R) induces the desquamation of the intestinal epithelium, increases the intestinal permeability, and in patients often causes fatal conditions including sepsis and multiple organ failure. Keratinocyte growth factor (KGF) increases intestinal growth, although little is known about KGF activity on intestinal function after intestinal I/R. We hypothesized that KGF administration would improve the intestinal function in a mouse model of intestinal I/R. Methods Adult C57BL/6J mice were randomized to three groups: Sham, I/R group and I/R+KGF group. Mice were killed on day 5, and the small bowel was harvested for histology, wet weight, RNA and protein content analysis. Epithelial cell (EC) proliferation was detected by immunohistochemistry for PCNA, and apoptosis was determined by TUNEL staining. The expressions of Claudin-1 and ZO-1 were detected by immunohistochemistry. Epithelial barrier function was assessed with transepithelial resistance (TER). Results KGF significantly increased the intestinal wet weight, contents of intestinal protein and RNA, villus height, crypt depth and crypt cell proliferation, while KGF resulted in the decrease of epithelial apoptosis. KGF also stimulated the recovery of mucosal structures and attenuated the disrupted distribution of TJ proteins. Moreover, KGF attenuated the intestinal I/R-induced decrease in TER and maintained the intestinal barrier function. Conclusion KGF administration improves the epithelial structure and barrier function in a mouse model of intestinal I/R. This suggests that KGF may have clinical applicability.

Cai, Yujiao; Wang, Wensheng; Liang, Hongying; Sun, Lihua; Teitelbaum, Daniel H.; Yang, Hua

2012-01-01

68

A decisive function of transforming growth factor-?/Smad signaling in tissue morphogenesis and differentiation of human HaCaT keratinocytes  

PubMed Central

?The mechanism by which transforming growth factor-? (TGF?) regulates differentiation in human epidermal keratinocytes is still poorly understood. To assess the role of Smad signaling, we engineered human HaCaT keratinocytes either expressing small interfering RNA against Smads2, 3, and 4 or overexpressing Smad7 and verified impaired Smad signaling as decreased Smad phosphorylation, aberrant nuclear translocation, and altered target gene expression. Besides abrogation of TGF?-dependent growth inhibition in conventional cultures, epidermal morphogenesis and differentiation in organotypic cultures were disturbed, resulting in altered tissue homeostasis with suprabasal proliferation and hyperplasia upon TGF? treatment. Neutralizing antibodies against TGF?, similar to blocking the actions of EGF-receptor or keratinocyte growth factor, caused significant growth reduction of Smad7-overexpressing cells, thereby demonstrating that epithelial hyperplasia was attributed to TGF?-induced “dermis”-derived growth promoting factors. Furthermore impaired Smad signaling not only blocked the epidermal differentiation process or caused epidermal-to-mesenchymal transition but induced a switch to a complex alternative differentiation program, best characterized as mucous/intestinal-type epithelial differentiation. As the same alternative phenotype evolved from both modes of Smad-pathway interference, and reduction of Smad7-overexpression caused reversion to epidermal differentiation, our data suggest that functional TGF?/Smad signaling, besides regulating epidermal tissue homeostasis, is not only essential for terminal epidermal differentiation but crucial in programming different epithelial differentiation routes.

Buschke, Susanne; Stark, Hans-Jurgen; Cerezo, Ana; Pratzel-Wunder, Silke; Boehnke, Karsten; Kollar, Jasmin; Langbein, Lutz; Heldin, Carl-Henrik; Boukamp, Petra

2011-01-01

69

A protective role for keratinocyte growth factor in a murine model of chemotherapy and radiotherapy-induced mucositis  

SciTech Connect

Purpose: To evaluate the activity of palifermin (rHuKGF) in a murine model of mucosal damage induced by a radiotherapy/chemotherapy (RT/CT) regimen mimicking treatment protocols used in head-and-neck cancer patients. Methods and Materials: A model of mucosal damage induced by RT/CT was established by injecting female BDF1 mice with cisplatin (10 mg/kg) on Day 1; 5-fluorouracil (40 mg/kg/day) on Days 1-4, and irradiation (5 Gy/day) to the head and neck on Days 1-5. Palifermin was administered subcutaneously on Days -2 to 0 (5 mg/kg/day) and on Day 5 (5 mg/kg). Evaluations included body weight, organ weight, keratinocyte growth factor receptor expression, epithelial thickness, and cellular proliferation. Results: Initiation of the radiochemotherapeutic regimen resulted in a reduction in body weight in control animals. Palifermin administration suppressed weight loss and resulted in increased organ weight (salivary glands and small intestine), epithelial thickness (esophagus and tongue), and cellular proliferation (tongue and salivary glands). Conclusions: Administration of palifermin before RT/CT promotes cell proliferation and increases in epithelial thickness in the oral mucosa, salivary glands, and digestive tract. Palifermin administration before and after RT/CT mitigates weight loss and a trophic effect on the intestinal mucosa and salivary glands, suggesting that palifermin use should be investigated further in the RT/CT settings, in which intestinal mucositis and salivary gland dysfunction are predominant side effects of cytotoxic therapy.

Borges, Luis [Departments of Hematology, Cancer Biology, and Pathology, Amgen Inc., Thousand Oaks, CA (United States)]. E-mail: borgesl@amgen.com; Rex, Karen L. [Departments of Hematology, Cancer Biology, and Pathology, Amgen Inc., Thousand Oaks, CA (United States); Chen, Jennifer N. [Departments of Hematology, Cancer Biology, and Pathology, Amgen Inc., Thousand Oaks, CA (United States); Wei, Ping [Departments of Hematology, Cancer Biology, and Pathology, Amgen Inc., Thousand Oaks, CA (United States); Kaufman, Stephen [Departments of Hematology, Cancer Biology, and Pathology, Amgen Inc., Thousand Oaks, CA (United States); Scully, Sheila [Departments of Hematology, Cancer Biology, and Pathology, Amgen Inc., Thousand Oaks, CA (United States); Pretorius, James K. [Departments of Hematology, Cancer Biology, and Pathology, Amgen Inc., Thousand Oaks, CA (United States); Farrell, Catherine L. [Departments of Hematology, Cancer Biology, and Pathology, Amgen Inc., Thousand Oaks, CA (United States)

2006-09-01

70

1,25-dihydroxyvitamin D3, transforming growth factor beta1, calcium, and ultraviolet B radiation induce apoptosis in cultured human keratinocytes.  

PubMed

Apoptosis is a cellular process of self-directed suicide that plays a key role during morphogenesis and in the maintenance of homeostasis in continuously renewing tissues. Currently, apoptosis is detected mainly by gel electrophoresis of fragmented DNA and by typical ultrastructural features such as cell shrinkage and chromatin condensation. Recently, an in situ technique was developed that allows the detection of the apoptotic process in cells and the quantitation of apoptosis in cell populations. We applied this technique to evaluate the apoptotic process in cultured normal human keratinocytes under basic conditions and after stimulation with factors and agents that are presumed but have never been proved to induce apoptosis in these cells. Apoptosis was analyzed after stimulation with 1,25-dihydroxyvitamin D3 [1,25(OH)2D3], transforming growth factor beta1 (TGFbeta1), calcium, UVB, or tumor necrosis factor alpha (TNFalpha). All these factors except TNFalpha induced apoptosis in human keratinocytes. Whereas UVB and calcium were good apoptogenic stimuli at 6 and 24 h, respectively, the vitamin D derivative and TGFbeta1 induced apoptosis after 5 and 6 d in culture. Apoptosis was also established by DNA fragmentation and electron microscopy. Finally, TUNEL technique showed that the number of apoptotic cells increases slightly (5-10%) from 24 to 144 h even in untreated keratinocytes. Our studies indicate that factors normally involved in the regulation of cell growth and differentiation can also control apoptosis. PMID:9284090

Benassi, L; Ottani, D; Fantini, F; Marconi, A; Chiodino, C; Giannetti, A; Pincelli, C

1997-09-01

71

Long-term maintenance of limbal epithelial progenitor cells using rho kinase inhibitor and keratinocyte growth factor.  

PubMed

Corneal epithelial stem cells are located in the limbus, the junction between the cornea and the conjunctiva. A limbal epithelium model in vitro would be useful for the study of epithelial stem cells, as well as improving the quality of cultivated epithelial sheets for the treatment of limbal stem cell deficiency. In this study, we succeeded in constructing a limbal epithelium-like structure that could be maintained for at least 5 months in vitro. We modified conventional medium by replacing epidermal growth factor with keratinocyte growth factor (KGF) and adding Y-27632, a rho kinase inhibitor. Using this medium, epithelial cells freshly isolated from human limbus were cocultured with human mesenchymal stem cell-derived feeder cells. Cells formed a stratified layer without air exposure, and both basal and suprabasal layers maintained their unique morphologies for up to 5 months. Basal layers expressed the progenitor marker p63 uniformly and K15 heterogeneously. Expressions of PAX6, K3, and K12 indicated that cell sheets underwent normal differentiation in the corneal epithelium lineage. Although medium was changed daily after day 7, cell debris was observed every day, suggesting that cell sheets underwent turnover. Furthermore, secondary colonies were observed from cells dissociated from 1-month and 3-month cultured sheets. In conclusion, human limbal epithelial cell sheet cultures with KGF and Y-27632 maintained stratification, high expression of both stem/progenitor markers and differentiation markers, and colony-forming cells long-term. This protocol may be useful as an in vitro limbal epithelial model for basic studies. PMID:23981725

Miyashita, Hideyuki; Yokoo, Seiichi; Yoshida, Satoru; Kawakita, Tetsuya; Yamagami, Satoru; Tsubota, Kazuo; Shimmura, Shigeto

2013-08-27

72

Reduction of radiochemotherapy-induced early oral mucositis by recombinant human keratinocyte growth factor (palifermin): Experimental studies in mice  

SciTech Connect

Purpose: To study the effect of recombinant human keratinocyte growth factor (rHuKGF or palifermin) on oral mucositis induced by radiochemotherapy in a mouse model. Methods and Materials: Cis-diamminedichloroplatinum (cisplatin) and/or 5-fluorouracil were given before single dose irradiation, combined with palifermin before or after the treatment, or both. Daily fractionated irradiation for 2 weeks was followed by graded test doses. With additional chemotherapy in Week 1, palifermin was given before radiotherapy and at the end of the first week, or additionally at the end of Week 2. Radiochemotherapy in Week 2 was combined with palifermin at the end of Weeks 1 and 2, Weeks 1, 2, and 3, or additionally before radiotherapy. Ulceration of mouse tongue mucosa was analyzed as the endpoint. Results: The dose associated with ulcer induction in 50% of the mice (ED{sub 50}) for single-dose irradiation was 11.5 {+-} 0.7 Gy. Palifermin increased the ED{sub 50} to about 19 Gy in all protocols tested. Similar values were observed when chemotherapy was added before irradiation. With fractionated irradiation, palifermin increased the ED{sub 50} for test irradiation from 5.7 {+-} 1.5 Gy to 12-15 Gy, depending on the administration protocol. With chemotherapy in Week 1, two palifermin injections had no significant effect, but a third injection increased the ED{sub 50} to 13 Gy. With chemotherapy in Week 2, all palifermin protocols resulted in ED{sub 50} values of 13-14 Gy. Conclusion: A marked increase in oral mucosal radiation tolerance by palifermin was found, which was preserved in combinations with chemotherapy using cisplatin and/or 5-fluorouracil.

Doerr, Wolfgang [Klinik und Poliklinik fuer Strahlentherapie und Radioonkologie, Medical Faculty Carl Gustav Carus, University of Technology, Dresden (Germany) and Experimentelles Zentrum, Medical Faculty Carl Gustav Carus, University of Technology, Dresden (Germany)]. E-mail: doerr@rcs.urz.tu-dresden.de; Baessler, Stefan; Reichel, Sandra [Klinik und Poliklinik fuer Strahlentherapie und Radioonkologie, Medical Faculty Carl Gustav Carus, University of Technology, Dresden (Germany); Spekl, Kathrin [Klinik und Poliklinik fuer Strahlentherapie und Radioonkologie, Medical Faculty Carl Gustav Carus, University of Technology, Dresden (Germany); Experimentelles Zentrum, Medical Faculty Carl Gustav Carus, University of Technology, Dresden (Germany)

2005-07-01

73

Localization of nerve growth factor (NGF) and low-affinity NGF receptors in touch domes and quantification of NGF mRNA in keratinocytes of adult rats.  

PubMed

Touch domes are clearly delineated mechanoreceptors that are visible on the depilated skin of mammals. These structures consist of a sharply circumscribed disk of thickened epithelium surmounting a group of Merkel cells that are innervated by type I sensory neurons. These characteristic cutaneous structures provide an ideal opportunity for investigating whether the localization of nerve growth factor (NGF) in the skin is related to sites of sensory axon termination. For these reasons, we have used immunocytochemistry to study the distribution of NGF and the low-affinity NGF receptor (p75NGFR) in the touch domes of adult rat skin. Intense NGF-like immunoreactivity was sharply restricted to keratinocytes (excluding the stratum corneum) of the thickened epidermis of touch domes. The epidermis immediately surrounding touch domes and the epidermis of the tylotrich hair follicle associated with touch domes were not stained by anti-NGF antiserum. Merkel cells of the basal epidermis of touch domes were immunonegative for NGF but were immunopositive for p75NGFR as were the type I nerve endings innervating these cells. Quantitative Northern blotting revealed that the level of NGF mRNA was substantially higher in keratinocytes isolated from the stratum granulosum and stratum spinosum than in keratinocytes isolated from the stratum germinativum. These findings indicate that NGF synthesis in mature skin has a highly restricted regional distribution that is primarily associated with the innervation of a specialized touch receptor. PMID:8063962

English, K B; Harper, S; Stayner, N; Wang, Z M; Davies, A M

1994-06-15

74

The neuronal nitric oxide synthase is upregulated in mouse skin repair and in response to epidermal growth factor in human HaCaT keratinocytes.  

PubMed

Expression of nNOS mRNA was found in normal human and mouse skin tissue. Upon wounding, we observed a rapid downregulation of nNOS mRNA and protein in wounds of mice; however, when repair continued, nNOS mRNA was strongly upregulated and nNOS protein expression peaked at late stages of healing. Immunohistochemistry revealed wound keratinocytes as the cellular source of nNOS. In line with the in vivo situation, we found a basal expression of nNOS in the human keratinocyte cell line HaCaT. A marked stimulation of nNOS expression in the cells was achieved with epidermal growth factor receptor (EGFR) ligands such as epidermal growth factor (EGF), heparin-binding EGF, transforming growth factor-alpha and two alternate splicing forms of the neuregulin gene. EGF-induced induction of nNOS was completely inhibited by the specific EGFR antagonist PD153035 and by the EGFR and Janus kinase 2/3 inhibitor AG490. Activation of EGFR might contribute to the observed upregulation of nNOS also in skin repair, as we found a spatial and temporal correlation of phosphorylated EGFR (Y1173) with nNOS expression at the wound site. Thus, in addition to the inducible- and endothelial-type NOS isoforms, also nNOS expression is regulated in the process of cutaneous wound repair. PMID:15191553

Boissel, Jean-Paul; Ohly, Dorothea; Bros, Matthias; Gödtel-Armbrust, Ute; Förstermann, Ulrich; Frank, Stefan

2004-07-01

75

The protective effect of recombinant human keratinocyte growth factor on radiation-induced pulmonary toxicity in rats  

SciTech Connect

Purpose: Radiation-induced lung toxicity is a significant dose-limiting side effect of radiotherapy for thoracic tumors. Recombinant human keratinocyte growth factor (rHuKGF) has been shown to be a mitogen for type II pneumocytes. The purpose of this study was to determine whether rHuKGF prevents or ameliorates the severity of late lung damage from fractionated irradiation in a rat model. Methods and materials: Female Fisher 344 rats were irradiated to the right hemithorax with a dose of 40 Gy/5 fractions/5 days. rHuKGF at dose of 5 mg/kg or 15 mg/kg was given via a single intravenous injection 10 min after the last fraction of irradiation. Animals were followed for 6 months after irradiation. Results: The breathing rate increased beginning at 6 weeks and reached a peak at 14 weeks after irradiation. The average breathing frequencies in the irradiated groups with rHuKGF (5 mg/kg and 15 mg/kg) treatment were significantly lower than that in the group receiving radiation without rHuKGF (116.5 {+-} 1.0 and 115.2 {+-} 0.8 vs 123.5 {+-} 1.2 breaths/min, p < 0.01). The severity of lung fibrosis and the level of immunoreactivity of integrin {alpha}v{beta}6, TGF{beta}1, type II TGF{beta} receptor, Smad3, and phosphorylated Smad2/3 were significantly decreased only in the group receiving irradiation plus high-dose rHuKGF treatment compared with irradiation plus vehicle group, suggesting a dose response for the effect of rHuKGF. Conclusions: This study is the first to demonstrate that rHuKGF treatment immediately after irradiation protects against late radiation-induced pulmonary toxicity. These results suggest that restoration of the integrity of the pulmonary epithelium via rHuKGF stimulation may downregulate the TGF-{beta}-mediated fibrosis pathway. These data also support the use of rHuKGF in a clinical trial designed to prevent radiation-induced lung injury.

Chen Liguang [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Brizel, David M. [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Rabbani, Zahid N. [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Samulski, Thaddeus V. [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Farrell, Catherine L. [Amgen, Inc., Thousand Oaks, CA (United States); Larrier, Nicole [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Anscher, Mitchell S. [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Vujaskovic, Zeljko [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States)]. E-mail: vujas@radonc.duke.edu

2004-12-01

76

Severe ulceration with impaired induction of growth factors and cytokines in keratinocytes after trichloroacetic acid application on TRPV1-deficient mice.  

PubMed

Transient receptor potential vanilloid 1 (TRPV1) is a highly polymodal TRP channel activated by various stimuli, including capsaicin, heat and acids. TRPV1 expression can be detected widely but is highest in sensory neurons and its activation alerts the body to noxious signals via neurogenic pain. Although TRPV1 is reportedly localized in the epidermis, it remains unclear how TRPV1 is involved in the chemical peeling processes with cytotoxic acids. Therefore, in this study, the role of TRPV1 on the effects of trichloroacetic acid (TCA) peeling was assessed using TRPV1-deficient mice. Following the confirmation of TRPV1 expression in murine keratinocytes with reverse transcription-polymerase chain reaction and immunohistochemistry, the effects of TCA on TRPV1-deficient mouse skin were compared with those on wild-type mouse skin. Our results indicated that TRPV1 expression was not required for TCA-induced DNA damage, as shown by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling, but was indispensable for the TCA-induced production of distinct growth factors and cytokines by keratinocytes. Ulceration after TCA peeling was actually more severe in the absence of TRPV1, suggesting that the TRPV1-mediated epidermal production of growth factors and cytokines affected the damaging and healing processes of TCA-peeled skin to induce rejuvenation. PMID:22858856

Li, Hong-jin; Kanazawa, Nobuo; Kimura, Ayako; Kaminaka, Chikako; Yonei, Nozomi; Yamamoto, Yuki; Furukawa, Fukumi

77

Growth factors and extracellular matrix proteins during wound healing promoted with frozen cultured sheets of human epidermal keratinocytes  

Microsoft Academic Search

In a murine model of full-thickness wounds, healing is stimulated by the application of human frozen cultured epidermal sheets. With immunofluorescence techniques, we studied, during this process, the spatial and temporal pattern of expression of: transforming growth factor-! (TGF-!); transforming growth factor-# (TGF-#) isoforms 1, 2, and 3; platelet-derived growth factor (PDGF); and the extracellular matrix proteins fibronectin, collagen IV,

Elisa Tamariz-Domínguez; Federico Castro-Muñozledo; Walid Kuri-Harcuch

2002-01-01

78

Effect of a Vitamin D3 Analogue on Keratinocyte Growth Factor-Induced Cell Proliferation in Benign Prostate Hyperplasia  

Microsoft Academic Search

Prostate enlargement and function is under the dual control of androgens and intraprostatic growth factors. They regulate, in con- cert, prostate cell proliferation and apoptosis. An increased signaling of both growth factors and androgens are supposed to underlie benign prostate hyperplasia (BPH), one of the more common disorders of the aging male. Since, in clinical practice, androgen ablation resulted in

CLARA CRESCIOLI; MARIO MAGGI; GABRIELLA BARBARA VANNELLI; MICHAELA LUCONI; ROBERTO SALERNO; TULLIO BARNI; MASSIMO GULISANO; GIANNI FORTI; MARIO SERIO

2010-01-01

79

Plant Polyphenols Regulate Chemokine Expression and Tissue Repair in Human Keratinocytes Through Interaction with Cytoplasmic and Nuclear Components of Epidermal Growth Factor Receptor System  

PubMed Central

Abstract Aims: To evaluate mechanisms underlying modulation of inflammatory chemokines in primary human keratinocytes (normal human epidermal keratinocytes) and repair-related processes in wound models by plant polyphenols (PPs) with antioxidant and superoxide scavenging properties (verbascoside [Vb], resveratrol [Rv], polydatin [Pd], quercetin [Qr], and rutin). Results: Epidermal growth factor receptor (EGFR)-controlled chemokines CXCL8/interleukin 8 (IL-8), CCL2/monocyte chemotactic protein-1 (MCP-1), and CXCL10/interferon gamma-produced protein of 10?kDa (IP-10) were modulated by transforming growth factor alpha (TGF-?) and by the tumor necrosis factor alpha/interferon gamma combination (T/I). EGFR phosphorylation, nuclear translocation, and downstream cytoplasmic signaling pathways (extracellular regulation kinase [ERK]1/2, p38, STAT3, and PI-3K) were studied. All PPs did not affect TGF-?-induced STAT3 phosphorylation, whereas they suppressed T/I-activated NFkappaB and constitutive and T/I-induced but not TGF-?-induced ERK1/2 phosphorylation. Vb and Qr suppressed total EGFR phosphorylation, but they synergized with TGF-? to enhance nuclear accumulation of phosphorylated EGFR. Vb strongly inhibited TGF-?-induced p38 phosphorylation and T/I-induced NFkappaB and activator protein-1 (AP-1) binding to DNA. Vb was an effective inhibitor of T/I-stimulated chemokine synthesis, and it accelerated scratch wound healing in vitro. Anti-inflammatory and wound healing activities of Vb were confirmed in vivo in the full-thickness excision wound. Although Pd and Rv did not affect EGFR activation/translocation, they and Qr synergized with TGF-? and T/I in the induction of IL-8 transcription/synthesis while opposing enhanced MCP-1 and IP-10 transcription/synthesis connected with pharmacologically impaired EGFR functioning. Innovation: PPs perturb the EGFR system in human keratinocytes, and this effect may be implicated in the regulation of inflammatory and repair-related processes in the skin. Conclusion: Anti-inflammatory and wound healing effects of PPs depend on their interaction with EGFR-controlled cytoplasmic and nuclear pathways rather than on their direct redox properties. Antioxid. Redox Signal. 16, 314–328.

Pastore, Saveria; Lulli, Daniela; Fidanza, Paolo; Potapovich, Alla I.; Kostyuk, Vladimir A.; De Luca, Chiara; Mikhal'Chik, Elena

2012-01-01

80

Integrin expression by human epidermal keratinocytes can be modulated by interferon-gamma, transforming growth factor-beta, tumor necrosis factor-alpha, and culture on a dermal equivalent.  

PubMed

Receptors of the integrin family are largely confined to the basal layer of keratinocytes, both in human epidermis and in stratified cultures of human keratinocytes. However, suprabasal integrin expression is observed during epidermal wound healing and in psoriatic lesions. We have investigated potential stimuli of suprabasal expression. Addition of transforming growth factor-beta (TGF-beta), interferon-gamma (IFN-gamma), or tumor necrosis factor-alpha (TNF-alpha) to keratinocytes cultured with a 3T3 feeder layer did not induce suprabasal expression. The cytokines caused small changes in the levels of alpha 2 beta 1 or alpha 3 beta 1 on the surface of basal keratinocytes but had no significant effect on the proportion of cells adhering to fibronectin, type IV collagen, and laminin, and did not cause changes in the mobility of integrin subunits on polyacrylamide gels. Injection of TNF-alpha or IFN-gamma intradermally into healthy human volunteers induced an inflammatory response but did not induce suprabasal integrin expression. However, we did observe transient suprabasal integrin expression when keratinocytes were grown on a dermal equivalent consisting of fibroblasts in a collagen gel. One week after raising the cultures to the air-liquid interface, beta 1 integrins were found in all the viable cell layers, with suprabasal cells co-expressing integrins and involucrin; 1 week later integrins were confined to the basal layer. Addition of TGF-beta, IFN-gamma, or TNF-alpha to the dermal equivalents neither induced nor inhibited suprabasal integrin expression. We conclude that suprabasal integrin expression is not induced by the inflammatory cytokines tested, and instead may reflect the proliferation/differentiation status of the epidermis. PMID:7829883

Hertle, M D; Jones, P H; Groves, R W; Hudson, D L; Watt, F M

1995-02-01

81

Selective Modulation of Hedgehog\\/GLI Target Gene Expression by Epidermal Growth Factor Signaling in Human Keratinocytes  

Microsoft Academic Search

Hedgehog (HH)\\/GLI signaling plays a critical role in epidermal development and basal cell carcinoma. Here, we provide evidence that epidermal growth factor receptor (EGFR) signaling modulates the target gene expression profile of GLI transcription factors in epidermal cells. Using expression profiling and quantitative reverse transcriptase PCR, we identified a set of 19 genes whose transcription is synergisti- cally induced by

Maria Kasper; Harald Schnidar; Graham W. Neill; Michaela Hanneder; Stefan Klingler; Leander Blaas; Carmen Schmid; Cornelia Hauser-Kronberger; Gerhard Regl; Michael P. Philpott; Fritz Aberger

2006-01-01

82

Activated protein C enhances human keratinocyte barrier integrity via sequential activation of epidermal growth factor receptor and Tie2.  

PubMed

Keratinocytes play a critical role in maintaining epidermal barrier function. Activated protein C (APC), a natural anticoagulant with anti-inflammatory and endothelial barrier protective properties, significantly increased the barrier impedance of keratinocyte monolayers, measured by electric cell substrate impedance sensing and FITC-dextran flux. In response to APC, Tie2, a tyrosine kinase receptor, was rapidly activated within 30 min, and relocated to cell-cell contacts. APC also increased junction proteins zona occludens, claudin-1 and VE-cadherin. Inhibition of Tie2 by its peptide inhibitor or small interfering RNA abolished the barrier protective effect of APC. Interestingly, APC did not activate Tie2 through its major ligand, angiopoietin-1, but instead acted by binding to endothelial protein C receptor, cleaving protease-activated receptor-1 and transactivating EGF receptor. Furthermore, when activation of Akt, but not ERK, was inhibited, the barrier protective effect of APC on keratinocytes was abolished. Thus, APC activates Tie2, via a mechanism requiring, in sequential order, the receptors, endothelial protein C receptor, protease-activated receptor-1, and EGF receptor, which selectively enhances the PI3K/Akt signaling to enhance junctional complexes and reduce keratinocyte permeability. PMID:21173154

Xue, Meilang; Chow, Shu-Oi; Dervish, Suat; Chan, Yee-Ka Agnes; Julovi, Sohel M; Jackson, Christopher J

2010-12-20

83

Activated Protein C Enhances Human Keratinocyte Barrier Integrity via Sequential Activation of Epidermal Growth Factor Receptor and Tie2*  

PubMed Central

Keratinocytes play a critical role in maintaining epidermal barrier function. Activated protein C (APC), a natural anticoagulant with anti-inflammatory and endothelial barrier protective properties, significantly increased the barrier impedance of keratinocyte monolayers, measured by electric cell substrate impedance sensing and FITC-dextran flux. In response to APC, Tie2, a tyrosine kinase receptor, was rapidly activated within 30 min, and relocated to cell-cell contacts. APC also increased junction proteins zona occludens, claudin-1 and VE-cadherin. Inhibition of Tie2 by its peptide inhibitor or small interfering RNA abolished the barrier protective effect of APC. Interestingly, APC did not activate Tie2 through its major ligand, angiopoietin-1, but instead acted by binding to endothelial protein C receptor, cleaving protease-activated receptor-1 and transactivating EGF receptor. Furthermore, when activation of Akt, but not ERK, was inhibited, the barrier protective effect of APC on keratinocytes was abolished. Thus, APC activates Tie2, via a mechanism requiring, in sequential order, the receptors, endothelial protein C receptor, protease-activated receptor-1, and EGF receptor, which selectively enhances the PI3K/Akt signaling to enhance junctional complexes and reduce keratinocyte permeability.

Xue, Meilang; Chow, Shu-Oi; Dervish, Suat; Chan, Yee-Ka Agnes; Julovi, Sohel M.; Jackson, Christopher J.

2011-01-01

84

AMPK regulation of the growth of cultured human keratinocytes  

Microsoft Academic Search

AMP kinase (AMPK) is a fuel sensing enzyme that responds to cellular energy depletion by increasing processes that generate ATP and inhibiting others that require ATP but are not acutely necessary for survival. In the present study, we examined the relationship between AMPK activation and the growth (proliferation) of cultured human keratinocytes and assessed whether the inhibition of keratinocyte growth

Asish K.. Saha; Kelly Persons; Joshua D. Safer; Zhijun Luo; Michael F. Holick; Neil B. Ruderman

2006-01-01

85

Retinoic Acid Resistance at Late Stages of Human Papillomavirus Type 16-Mediated Transformation of Human Keratinocytes Arises Despite Intact Retinoid Signaling and Is Due to a Loss of Sensitivity to Transforming Growth Factor-?  

Microsoft Academic Search

In our in vitro model of human cell carcinogenesis, normal human foreskin keratinocytes (HKc) transfected with human papillomavirus type 16 DNA (HKc\\/HPV16) progress toward malignancy through several phenotypically defined and reproducible “steps” that include immortalization, growth factor independence (HKc\\/GFI), differentiation resistance (HKc\\/DR), and ultimately malignant conversion. While HKc\\/HPV16 are very sensitive to growth inhibition by all-trans-retinoic acid (RA) at early

Darrell R. Borger; Yi-de Mi; Gemma Geslani; Li Li Zyzak; Ayse Batova; Timur S. W. Engin; Lucia Pirisi; Kim E. Creek

2000-01-01

86

[Transfection of recombinant adenoviral vector with co-expressing keratinocyte growth factor and enhanced green fluorescent protein to murine bone marrow mesenchymal stem cells].  

PubMed

To construct the adenoviral vector with co-expressing keratinocyte growth factor (KGF) and enhanced green fluorescent protein (EGFP) for transfection into the mesenchymal stem cells (MSC), the target gene KGF was cloned into the shuttle plasmid with the report gene EGFP, then the recombinant shuttle plasmid was transformed into DH5a bacteria to recombine with backbone vector pAdxsi. Next, the plasmid pAd-EGFP-mKGF was amplified in H293 cells and the viral titer was determined. The MSC were separated and enriched by using bone marrow adherent culture and identified in vitro to observe the efficiency of transfection. The results indicated that the recombinant shuttle plasmid pShuttle-EGFP-mKGF digested with restriction endonucleases was confirmed by two products which length was about 0.6 kb and 5.1 kb, respectively; the recombinant plasmid pAdxsi-EGFP-mKGF digested with restriction endonucleases was confirmed by 7 products; recombinant adenoviral vector Ad-EGFP-mKGF was amplified to titer of 1.6 × 10(10) pfu/ml. At 10 h after transfecting MSC began to express fluorescence at 6 to 8 days later, the fluorescence reached to the peak with infection rate of 92.3, at 28 days the expression of fluorescence was still observed. It is concluded that the recombinant adenoviral vector Ad-EGFP-mKGF is successfully constructed and can transfect MSC effectively and safely. PMID:22541113

Wang, Mei-Hua; Hu, Kai-Xun; Li, Xiao-Bing

2012-04-01

87

Selective Modulation of Hedgehog/GLI Target Gene Expression by Epidermal Growth Factor Signaling in Human Keratinocytes  

PubMed Central

Hedgehog (HH)/GLI signaling plays a critical role in epidermal development and basal cell carcinoma. Here, we provide evidence that epidermal growth factor receptor (EGFR) signaling modulates the target gene expression profile of GLI transcription factors in epidermal cells. Using expression profiling and quantitative reverse transcriptase PCR, we identified a set of 19 genes whose transcription is synergistically induced by GLI1 and parallel EGF treatment. Promoter studies of a subset of GLI/EGF-regulated genes, including the genes encoding interleukin-1 antagonist IL1R2, Jagged 2, cyclin D1, S100A7, and S100A9, suggest convergence of EGFR and HH/GLI signaling at the level of promoters of selected direct GLI target genes. Inhibition of EGFR and MEK/ERK but not of phosphatidylinositol 3-kinase/AKT abrogated synergistic activation of GLI/EGF target genes, showing that EGFR can signal via RAF/MEK/ERK to cooperate with GLI proteins in selective target gene regulation. Coexpression of the GLI/EGF target IL1R2, EGFR, and activated ERK1/2 in human anagen hair follicles argues for a cooperative role of EGFR and HH/GLI signaling in specifying the fate of outer root sheath (ORS) cells. We also show that EGF treatment neutralizes GLI-mediated induction of epidermal stem cell marker expression and provide evidence that EGFR signaling is essential for GLI-induced cell cycle progression in epidermal cells. The results suggest that EGFR signaling modulates GLI target gene profiles which may play an important regulatory role in ORS specification, hair growth, and possibly cancer.

Kasper, Maria; Schnidar, Harald; Neill, Graham W.; Hanneder, Michaela; Klingler, Stefan; Blaas, Leander; Schmid, Carmen; Hauser-Kronberger, Cornelia; Regl, Gerhard; Philpott, Michael P.; Aberger, Fritz

2006-01-01

88

Keratinocyte growth factor and dexamethasone plus elevated cAMP levels synergistically support pluripotent stem cell differentiation into alveolar epithelial type II cells.  

PubMed

Alveolar epithelial type II (ATII)-like cells can be generated from murine embryonic stem cells (ESCs), although to date, no robust protocols applying specific differentiation factors are established. We hypothesized that the keratinocyte growth factor (KGF), an important mediator of lung organogenesis and primary ATII cell maturation and proliferation, together with dexamethasone, 8-bromoadenosine-cAMP, and isobutylmethylxanthine (DCI), which induce maturation of primary fetal ATII cells, also support the alveolar differentiation of murine ESCs. Here we demonstrate that the above stimuli synergistically potentiate the alveolar differentiation of ESCs as indicated by increased expression of the surfactant proteins (SP-) C and SP-B. This effect is most profound if KGF is supplied not only in the late stage, but at least also during the intermediate stage of differentiation. Our results indicate that KGF most likely does not enhance the generation of (mes)endodermal or NK2 homeobox 1 (Nkx2.1) expressing progenitor cells but rather, supported by DCI, accelerates further differentiation/maturation of respiratory progeny in the intermediate phase and maturation/proliferation of emerging ATII cells in the late stage of differentiation. Ultrastructural analyses confirmed the presence of ATII-like cells with intracellular composite and lamellar bodies. Finally, induced pluripotent stem cells (iPSCs) were generated from transgenic mice with ATII cell-specific lacZ reporter expression. Again, KGF and DCI synergistically increased SP-C and SP-B expression in iPSC cultures, and lacZ expressing ATII-like cells developed. In conclusion, ATII cell-specific reporter expression enabled the first reliable proof for the generation of murine iPSC-derived ATII cells. In addition, we have shown KGF and DCI to synergistically support the generation of ATII-like cells from ESCs and iPSCs. Combined application of these factors will facilitate more efficient generation of stem cell-derived ATII cells for future basic research and potential therapeutic application. PMID:23176317

Schmeckebier, Sabrina; Mauritz, Christina; Katsirntaki, Katherina; Sgodda, Malte; Puppe, Verena; Duerr, Julia; Schubert, Susanne C; Schmiedl, Andreas; Lin, Qiong; Pale?ek, Jiri; Draeger, Gerald; Ochs, Matthias; Zenke, Martin; Cantz, Tobias; Mall, Marcus A; Martin, Ulrich

2013-01-15

89

AMPK regulation of the growth of cultured human keratinocytes  

SciTech Connect

AMP kinase (AMPK) is a fuel sensing enzyme that responds to cellular energy depletion by increasing processes that generate ATP and inhibiting others that require ATP but are not acutely necessary for survival. In the present study, we examined the relationship between AMPK activation and the growth (proliferation) of cultured human keratinocytes and assessed whether the inhibition of keratinocyte growth by vitamin D involves AMPK activation. In addition, we explored whether the inhibition of keratinocyte proliferation as they approach confluence could be AMPK-related. Keratinocytes were incubated for 12 h with the AMPK activator, 5-aminoimidazole-4-carboxamide-1-{beta}-D-ribofuranoside (AICAR). At concentrations of 10{sup -4} and 10{sup -3} M, AICAR inhibited keratinocyte growth by 50% and 95%, respectively, based on measurements of thymidine incorporation into DNA. It also increased AMPK and acetyl CoA carboxylase phosphorylation (P-AMPK and P-ACC) and decreased the concentration of malonyl CoA confirming that AMPK activation had occurred. Incubation with the thiazolidinedione, troglitazone (10{sup -6} M) caused similar alterations in P-AMPK, P-ACC, and cell growth. In contrast, the well known inhibition of keratinocyte growth by 1,25-dihydroxyvitamin D{sub 3} (10{sup -7} and 10{sup -6} M) was not associated with changes in P-AMPK or P-ACC. Like most cells, the growth of keratinocytes diminished as they approached confluence. Thus, it was of note that we found a progressive increase in P-AMPK (1.5- to 2-fold, p < 0.05) as keratinocytes grown in control medium went from 25% to 100% confluence. In conclusion, the data are consistent with the hypothesis that activation of AMPK acts as a signal to diminish the proliferation of cultured keratinocytes as they approach confluence. They also suggest that AMPK activators, such as AICAR and troglitazone, inhibit keratinocyte growth and that the inhibition of cell growth by 1,25-dihydroxyvitamin D{sub 3} is AMPK-independent.

Saha, Asish K. [Endocrinology, Diabetes and Nutrition, Department of Medicine, Boston University School of Medicine, Boston, MA (United States)]. E-mail: aksaha@bu.edu; Persons, Kelly [Endocrinology, Diabetes and Nutrition, Department of Medicine, Boston University School of Medicine, Boston, MA (United States); Safer, Joshua D. [Endocrinology, Diabetes and Nutrition, Department of Medicine, Boston University School of Medicine, Boston, MA (United States); Luo Zhijun [Endocrinology, Diabetes and Nutrition, Department of Medicine, Boston University School of Medicine, Boston, MA (United States); Holick, Michael F. [Endocrinology, Diabetes and Nutrition, Department of Medicine, Boston University School of Medicine, Boston, MA (United States); Ruderman, Neil B. [Endocrinology, Diabetes and Nutrition, Department of Medicine, Boston University School of Medicine, Boston, MA (United States)

2006-10-20

90

Up-Regulation of Intestinal Epithelial Cell Derived IL-7 Expression by Keratinocyte Growth Factor through STAT1/IRF-1, IRF-2 Pathway  

PubMed Central

Background Epithelial cells(EC)-derived interleukin-7 (IL-7) plays a crucial role in control of development and homeostasis of neighboring intraepithelial lymphocytes (IEL), and keratinocyte growth factor (KGF) exerts protective effects on intestinal epithelial cells and up-regulates EC-derived IL-7 expression through KGFR pathway. This study was to further investigate the molecular mechanism involved in the regulation of IL-7 expression by KGF in the intestine. Methods Intestinal epithelial cells (LoVo cells) and adult C57BL/6J mice were treated with KGF. Epithelial cell proliferation was studied by flow cytometry for BrdU-incorporation and by immunohistochemistry for PCNA staining. Western blot was used to detect the changes of expression of P-Tyr-STAT1, STAT1, and IL-7 by inhibiting STAT1. Alterations of nuclear extracts and total proteins of IRF-1, IRF-2 and IL-7 following IRF-1 and IRF-2 RNA interference with KGF treatment were also measured with western blot. Moreover, IL-7 mRNA expressions were also detected by Real-time PCR and IL-7 protein level in culture supernatants was measured by enzyme linked immunosorbent assay(ELISA). Results KGF administration significantly increased LoVo cell proliferation and also increased intestinal wet weight, villus height, crypt depth and crypt cell proliferation in mice. KGF treatment led to increased levels of P-Tyr-STAT1, RAPA and AG490 both blocked P-Tyr-STAT1 and IL-7 expression in LoVo cells. IRF-1 and IRF-2 expression in vivo and in vitro were also up-regulated by KGF, and IL-7 expression was decreased after IRF-1 and IRF-2 expression was silenced by interfering RNA, respectively. Conclusion KGF could up-regulate IL-7 expression through the STAT1/IRF-1, IRF-2 signaling pathway, which is a new insight in potential effects of KGF on the intestinal mucosal immune system.

Cai, Yu-Jiao; Wang, Wen-Sheng; Yang, Yang; Sun, Li-Hua; Teitelbaum, Daniel H.; Yang, Hua

2013-01-01

91

The autonomous growth of human papillomavirus type 16-immortalized keratinocytes is related to the endothelin-1 autocrine loop.  

PubMed Central

Some human papillomaviruses (HPVs) such as HPV type 16 (HPV16) and HPV18 are involved in cervical carcinoma, and they can immortalize and transform keratinocytes. Endothelin-1 (ET-1) is produced in keratinocytes and has been shown to act through ETA receptors as an autocrine growth factor for keratinocytes. This study examines whether HPV16 alters the ET-1-mediated autocrine loop in human keratinocytes, providing a selective growth advantage for transformed cells. ET-1 is released in similar amounts from normal and HPV-transfected keratinocytes. All HPV-transfected cell lines express high-affinity ETA receptors. A two-fold increase in ET-1 binding sites is present in HPV16-immortalized keratinocytes, and this effect seems to be linked to the overexpression of mRNA for this receptor rather than to differences in the surface/internalized ratio of the receptors. ET-1 induces significant increases in [3H]thymidine incorporation and cell proliferation. Furthermore, HPV-transfected keratinocytes can proliferate in the absence of any growth factor added to the growth medium, and the ETA receptor antagonist BQ123 prevents this proliferation. These data suggest a new mechanism in the growth control of HPV-transformed cells mediated by the upregulation of ET-1 autocrine loop.

Venuti, A; Marcante, M L; Flamini, S; Di Castro, V; Bagnato, A

1997-01-01

92

Enhancement of intestinal growth and repair by growth factors  

Microsoft Academic Search

Recently, glucagon-like peptide 2 has emerged as a potent stimulator of epithelial growth, joining insulin-like growth factor I, hepatocyte growth factor and keratinocyte growth factor as potential treatment modalities for intestinal disorders associated with loss of mucosal mass, such as short bowel syndrome. Investigations into other members of the expanded epidermal growth factor peptide family, the development of more potent

Gordon S Howarth; Cheryl A Shoubridge

2001-01-01

93

Binding and biological effects of tumor necrosis factor alpha on cultured human neonatal foreskin keratinocytes.  

PubMed Central

Tumor necrosis factor alpha (TNF alpha) localizes to the epidermis when injected in vivo, but its role in the skin has heretofore not been evaluated. As a first approach to assessing the role of TNF alpha in the skin, we evaluated the binding and biological effects of TNF alpha on human neonatal foreskin keratinocytes maintained in culture. We found that TNF alpha at 0.3-1.0 nM inhibited proliferation of keratinocytes in a reversible fashion as demonstrated by a reduction in total DNA content and clonal growth. The antiproliferative effects were most marked when TNF alpha was added in the preconfluent stages of cell growth. Accompanying this antiproliferative effect was a stimulation by TNF alpha of differentiation of keratinocytes as indicated by the stimulation of cornified envelope formation. Keratinocytes specifically bound TNF alpha, reaching maximal binding in 2 h at 34 degrees C or 8 h at 4 degrees C. Much of the apparent binding at 34 degrees C was due to internalization of the TNF alpha. At 4 degrees C the rate of internalization was much less. Confluent keratinocytes showed a single class of high-affinity receptors with 1,250 receptors/cell and a Kd of 0.28 nM. These data suggest a role for TNF alpha in the growth and differentiation of the epidermis. Images

Pillai, S; Bikle, D D; Eessalu, T E; Aggarwal, B B; Elias, P M

1989-01-01

94

Amphiregulin Carboxy-Terminal Domain Is Required for Autocrine Keratinocyte Growth  

Microsoft Academic Search

The EGFR ligand amphiregulin (AREG) has been implicated as an important autocrine growth factor in several epithelial malignancies and in psoriasis, a hyperproliferative skin disorder. To characterize the mechanisms by which AREG regulates autocrine epithelial cell growth, we transduced human keratinocytes (KCs) with lentiviral constructs expressing tetracycline (TET)-inducible small hairpin RNA (shRNA). TET-induced expression of AREG shRNA markedly reduced autocrine

Stefan W Stoll; Jessica L Johnson; Yong Li; Laure Rittié; James T Elder

2010-01-01

95

Dyskeratosis Congenita Dermal Fibroblasts are Defective in Supporting the Clonogenic Growth of Epidermal Keratinocytes  

PubMed Central

Telomere shortening is associated with cellular senescence and aging. Dyskeratosis congenita (DC) is a premature aging syndrome caused by mutations in genes for telomerase components or telomere proteins. DC patients have very short telomeres and exhibit aging-associated pathologies including epidermal abnormalities and bone marrow failure. Here, we show that DC skin fibroblasts are defective in their ability to support the clonogenic growth of epidermal keratinocytes. Conditioned media transfer experiments demonstrated that this defect was largely due to lack of a factor or factors secreted from the DC fibroblasts. Compared to early passage normal fibroblasts, DC fibroblasts express significantly lower transcript levels of several genes that code for secreted proteins, including Insulin-like Growth Factor 1 (IGF1) and Hepatocyte Growth Factor (HGF). Aged normal fibroblasts with short telomeres also had reduced levels of IGF1 and HGF, similar to early passage DC fibroblasts. Knockdown of IGF1 or HGF in normal fibroblasts caused a reduction in the capacity of conditioned media from these fibroblasts to support keratinocyte clonogenic growth. Surprisingly, reconstitution of telomerase in DC fibroblasts did not significantly increase transcript levels of IGF1 or HGF or substantially increase the ability of the fibroblasts to support keratinocyte growth, indicating that the gene expression defect is not readily reversible. Our results suggest that telomere shortening in dermal fibroblasts leads to reduction in expression of genes such as IGF1 and HGF and that this may cause a defect in supporting normal epidermal proliferation.

Buckingham, Erin M.; Goldman, Frederick D.; Klingelhutz, Aloysius J.

2012-01-01

96

Dyskeratosis Congenita Dermal Fibroblasts are Defective in Supporting the Clonogenic Growth of Epidermal Keratinocytes.  

PubMed

Telomere shortening is associated with cellular senescence and aging. Dyskeratosis congenita (DC) is a premature aging syndrome caused by mutations in genes for telomerase components or telomere proteins. DC patients have very short telomeres and exhibit aging-associated pathologies including epidermal abnormalities and bone marrow failure. Here, we show that DC skin fibroblasts are defective in their ability to support the clonogenic growth of epidermal keratinocytes. Conditioned media transfer experiments demonstrated that this defect was largely due to lack of a factor or factors secreted from the DC fibroblasts. Compared to early passage normal fibroblasts, DC fibroblasts express significantly lower transcript levels of several genes that code for secreted proteins, including Insulin-like Growth Factor 1 (IGF1) and Hepatocyte Growth Factor (HGF). Aged normal fibroblasts with short telomeres also had reduced levels of IGF1 and HGF, similar to early passage DC fibroblasts. Knockdown of IGF1 or HGF in normal fibroblasts caused a reduction in the capacity of conditioned media from these fibroblasts to support keratinocyte clonogenic growth. Surprisingly, reconstitution of telomerase in DC fibroblasts did not significantly increase transcript levels of IGF1 or HGF or substantially increase the ability of the fibroblasts to support keratinocyte growth, indicating that the gene expression defect is not readily reversible. Our results suggest that telomere shortening in dermal fibroblasts leads to reduction in expression of genes such as IGF1 and HGF and that this may cause a defect in supporting normal epidermal proliferation. PMID:23251848

Buckingham, Erin M; Goldman, Frederick D; Klingelhutz, Aloysius J

2012-10-12

97

Modulation of TGF-?-inducible hypermotility by EGF and other factors in human prostate epithelial cells and keratinocytes  

Microsoft Academic Search

Keratinocytes migrating from a wound edge or initiating malignant invasion greatly increase their expression of the basement\\u000a membrane protein Laminin-322 (Lam332). In culture, keratinocytes initiate sustained directional hypermotility when plated\\u000a onto an incompletely processed form of Lam332 (Lam332?) or when treated with transforming growth factor beta (TGF-?), an inducer\\u000a of Lam332 expression. The development and tissue architecture of stratified squamous

Wei Wei; Patricia D. Barron; James G. Rheinwald

2010-01-01

98

Platelet-activating factor induces proliferation in differentiated keratinocytes.  

PubMed

Increased levels of platelet-activating factor (PAF; 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) are found in several inflammatory dermatoses, but PAF's exact role in epidermis is uncertain. In order to better understand the physiological consequences of excess PAF production in epidermis, we examined the gene regulatory effects of PAF short-term stimulation in differentiated HaCaT keratinocytes by transcriptional profiling. Even though PAF induces COX2 expression, we found that PAF regulates only few genes associated with inflammation in differentiated keratinocytes. Rather, we show that natural PAF rapidly regulates genes involved in proliferation, (anti)-apoptosis and migration, all sub-processes of re-epithelialization and wound healing. Moreover, profiling of phosphorylated kinases, cellular wound-scratch experiments, resazurin assay and flow cytometry cell cycle phase analysis all support a role for PAF in keratinocyte proliferation and epidermal re-epithelialization. In conclusion, these results suggest that PAF acts as an activator of proliferation and may, therefore, function as a connector between inflammation and proliferation in differentiated keratinocytes. PMID:23975504

Feuerherm, Astrid J; Jørgensen, Katarina M; Sommerfelt, Randi M; Eidem, Live E; Lægreid, Astrid; Johansen, Berit

2013-08-24

99

Hydrogen sulfide impairs keratinocyte cell growth and adhesion inhibiting mitogen-activated protein kinase signaling  

Microsoft Academic Search

The effects of exogenous hydrogen sulfide (H2S) on normal skin-derived immortalized human keratinocytes have been investigated in detail. We show in vitro that exogenous hydrogen sulfide reduces clonal growth, cell proliferation and cell adhesion of human keratinocytes. H2S, in fact, decreases the frequency of the putative keratinocyte stem cell subpopulation in culture, consequently affecting clonal growth, and impairs cell proliferation

Giuliana Gobbi; Francesca Ricci; Chiara Malinverno; Cecilia Carubbi; Maurizia Pambianco; Giuseppe de Panfilis; Marco Vitale; Prisco Mirandola

2009-01-01

100

Xylan-regulated delivery of human keratinocyte growth factor-2 to the inflamed colon by the human anaerobic commensal bacterium Bacteroides ovatus  

Microsoft Academic Search

BackgroundHuman growth factors are potential therapeutic agents for various inflammatory disorders affecting the gastrointestinal tract. However, they are unstable when administered orally and systemic administration requires high doses increasing the risk of unwanted side effects. Live microorganism-based delivery systems can overcome these problems although they suffer from the inability to control heterologous protein production and there are concerns regarding biosafety

Zaed Z R Hamady; Nigel Scott; Mark D Farrar; J Peter A Lodge; Keith T Holland; Terence Whitehead; Simon R Carding

2009-01-01

101

Role of melanoma growth stimulatory activity (MGSA/gro) on keratinocyte function in wound healing.  

PubMed

Melanoma growth stimulatory activity/gro alpha (MGSA), a member of the alpha-chemokine family, is produced by a variety of dermal and epidermal cells and can act in a paracrine and autocrine fashion. However, little is known about the importance of MGSA in wound healing. In this study, we quantified the levels of MGSA protein in burn blister and donor site wound fluids. We studied the effects of MGSA on proliferation and migration of primary human keratinocytes and modulation of their integrin expression. Blister fluids contained 0.79 ng/ml (range 0.018 to 4.86 ng/ml) MGSA. Substantial increasing amounts of MGSA were found in donor site fluids from day 1 through day 5 with mean levels ranging from 1.77 to 103 ng/ml at postoperative day 5, which correlated with increasing amounts of tumor necrosis factor alpha (r = 0.86), a known stimulus for MGSA production. In vitro proliferation experiments revealed a maximum stimulation (2.6-fold) with 10 ng/ ml MGSA for 7 days over unstimulated keratinocyte controls; the ED50 was 0.2 ng/ml. DNA content analysis revealed an increase in S phase with 10 ng/ml MGSA stimulation. In cultured keratinocytes, MGSA enhanced the mean fluorescence intensity for alpha 6, while no significant change was seen for beta 1, alpha 2 and alpha 5. We also studied the effect of topically applied MGSA (50 ng/cm2) on the healing of meshed split-thickness human skin grafts on athymic mice. In these wounds, MGSA stimulated the rate of epithelialization (P < 0.05) at day 7, and an increased proportion of mitotic keratinocytes was observed. Wound contraction was significantly (P < 0.05) reduced on days 7 and 14 in the MGSA-treated group. These results suggest that MGSA participates in wound healing by stimulating keratinocyte proliferation. PMID:9143736

Rennekampff, H O; Hansbrough, J F; Woods, V; Doré, C; Kiessig, V; Schröder, J M

1997-03-01

102

Taurin-conjugated ursodeoxycholic acid has a reversible inhibitory effect on human keratinocyte growth  

Microsoft Academic Search

Tauroursodeoxycholic acid (TUDC) is one of the most hydrophilic taurin conjugated bile acids. TUDC has a suppressive effect on DNA synthesis in primary cultured rat hepatocytes. In this study, we investigated the growth inhibitory effect of TUDC on cultured human keratinocytes. TUDC suppressed the proliferation of keratinocytes in a dose dependent fashion, as measured by both cell counts and 5-bromo-2?-deoxyuridine

Yuji Yamaguchi; Satoshi Itami; Kenju Nishida; Yumi Ando

1998-01-01

103

Immunohistochemical localization of transforming growth factor-? and epithelial growth factor receptor in human fetal developing skin, psoriasis and restrictive dermopathy  

Microsoft Academic Search

Keratinocytes release a number of cytokines interacting with other intra-and subepidermal cells during the initiation and\\u000a the perpetuation of skin inflammatory reactions. Cultured human keratinocytes overexpressing the transforming growth factor\\u000a alpha (TGF-alpha) assumed a spindled morphology and displayed increased locomotion. Moreover, the receptor for TGF-alpha,\\u000a the epithelial growth factor receptor (EGFR), is important for autocrine growth, promotion of cell survival,

Consolato Sergi; Philip Kahl; Herwart Fotto

2000-01-01

104

The Effect of Secretory Factors of Adipose-Derived Stem Cells on Human Keratinocytes  

PubMed Central

The beneficial effects of adipose-derived stem cell conditioned medium (ADSC-CM) on skin regeneration have been reported. Although the mechanism of how ADSC-CM promotes skin regeneration is unclear, ADSC-CM contained various growth factors and it is an excellent raw material for skin treatment. ADSC-CM produced in a hypoxia condition of ADSC—in other words, Advanced Adipose-Derived Stem cell Protein Extract (AAPE)—has great merits for skin regeneration. In this study, human primary keratinocytes (HKs), which play fundamental roles in skin tissue, was used to examine how AAPE affects HK. HK proliferation was significantly higher in the experimental group (1.22 ?g/mL) than in the control group. DNA gene chip demonstrated that AAPE in keratinocytes (p < 0.05) notably affected expression of 290 identified transcripts, which were associated with cell proliferation, cycle and migration. More keratinocyte wound healing and migration was shown in the experimental group (1.22 ?g/mL). AAPE treatment significantly stimulated stress fiber formation, which was linked to the RhoA-ROCK pathway. We identified 48 protein spots in 2-D gel analysis and selected proteins were divided into 64% collagen components and 30% non-collagen components as shown by the MALDI-TOF analysis. Antibody array results contained growth factor/cytokine such as HGF, FGF-1, G-CSF, GM-CSF, IL-6, VEGF, and TGF-?3 differing from that shown by 2-D analysis. Conclusion: AAPE activates HK proliferation and migration. These results highlight the potential of the topical application of AAPE in the treatment of skin regeneration.

Moon, Kyoung Mi; Park, Ye-Hyoung; Lee, Jae Seol; Chae, Yong-Byung; Kim, Moon-Moo; Kim, Dong-Soo; Kim, Byung-Woo; Nam, Soo-Wan; Lee, Jong-Hwan

2012-01-01

105

S100A11, an Dual Mediator for Growth Regulation of Human Keratinocytes  

PubMed Central

We previously revealed a novel signal pathway involving S100A11 for inhibition of the growth of normal human keratinocytes (NHK) caused by high Ca++ or transforming growth factor ?. Exposure to either agent resulted in transfer of S100A11 to nuclei, where it induced p21WAF1. In contrast, S100A11 has been shown to be overexpressed in many human cancers. To address this apparent discrepancy, we analyzed possible new functions of S100A11, and we provide herein evidence that 1) S100A11 is actively secreted by NHK; 2) extracellular S100A11 acts on NHK to enhance the production of epidermal growth factor family proteins, resulting in growth stimulation; 3) receptor for advanced glycation end products, nuclear factor-?B, Akt, and cAMP response element-binding protein are involved in the S100A11-triggered signal transduction; and 4) production and secretion of S100A11 are markedly enhanced in human squamous cancer cells. These findings indicate that S100A11 plays a dual role in growth regulation of epithelial cells.

Sakaguchi, Masakiyo; Sonegawa, Hiroyuki; Murata, Hitoshi; Kitazoe, Midori; Futami, Jun-ichiro; Kataoka, Ken; Yamada, Hidenori

2008-01-01

106

Cultivation, frozen storage, and clonal growth of normal human epidermal keratinocytes in serum-free media  

Microsoft Academic Search

Summary Methods are described for serum-free culture of human epidermal keratinocytes derived from neonatal foreskin tissue. Cultures are initiated, stored frozen, and returned to active growth, all with bovine pituitary extract as the only undefined supplement. Clonal growth assays are then performed in a biochemically defined medium. The degree of stratification and differentiation in the defined medium (and also with

Steven T. Boyce; Richard G. Ham

1985-01-01

107

UV-induced degradation of collagen I is mediated by soluble factors released from keratinocytes.  

PubMed

Photoaging is a complex condition but its hallmark is the destruction of dermal collagen. This has been attributed to the direct activation of fibroblast matrix metalloproteinases by solar UV. However, we report here that unirradiated fibroblasts increase metalloproteinase production and digest collagen when exposed to cell culture media from irradiated keratinocytes. Enhanced DNA repair in the keratinocytes ameliorates this response. This suggests that soluble factors induced by DNA damage in UV-exposed epidermal keratinocytes signal collagen degradation by fibroblasts in the dermis. This motif of DNA damage in keratinocytes producing effects on other cell types mediated by soluble factors was first identified by Kripke and colleagues in studying UV-induced immune suppression. PMID:18173703

Yarosh, Daniel; Dong, Kelly; Smiles, Kenneth

108

Identification of Functional Platelet-Activating Factor Receptors on Human Keratinocytes  

Microsoft Academic Search

Platelet-activating factor (PAP) is a potent inflammatory mediator that has been shown to be produced by human keratinocytes and is thought to play a role in cutaneous inflammation, Immunofluorescence and radioligand binding studies were used to characterize PAP receptors (PAF-R) on human keratinocytes and the human epidermoid cell lines A-431 and HaCaT. Indirect immunofluorescence studies demonstrated anti-PAF-R staining of primary

Jeffrey B. Travers; J. Clark Huff; Marek Rola-Pleszczynski; Erwin W. Gelfand; Joseph G. Morelli; Robert C. Murphy

1995-01-01

109

Kaposi's Sarcoma-Associated Herpesvirus Can Productively Infect Primary Human Keratinocytes and Alter Their Growth Properties  

PubMed Central

Previous studies have shown the presence of Kaposi's sarcoma-associated herpesvirus (KSHV/HHV8) DNA in endothelial cells, in keratinocytes in the basal layer of the epidermis overlying plaque-stage nodular lesions of cutaneous Kaposi's sarcoma (KS), and in the epithelial cells of eccrine glands within KS lesions. We infected primary cell cultures of human keratinocytes with KSHV/HHV8. At 6 days post infection, transcription of viral genes was detected by reverse transcriptase PCR (RT-PCR), and protein expression was documented by an immunofluorescence assay with an anti-LANA monoclonal antibody. To determine whether the viral lytic cycle was inducible by chemical treatment, KSHV/HHV8-infected keratinocytes were treated with 12-O-tetradecanoylphorbol-13-acetate (TPA) and RT-PCR was performed to confirm the transcription of lytic genes such as open reading frame 26, (which encodes a capsid protein). Finally, to assess infectious viral production, other primary human cells (human umbilical vein endothelial cells), were infected with concentrated supernatant of KSHV-infected, TPA-induced keratinocytes and the presence of viral transcripts was confirmed by RT-PCR. The uninfected keratinocytes senesced 3 to 5 weeks after mock infection, while the KSHV/HHV8-infected keratinocytes continued to proliferate and to date are still in culture. However, 8 weeks after infection, viral genomes were no longer detectable by nested PCR. Although the previously KSHV/HHV8-infected keratinocytes still expressed epithelial markers, they acquired new characteristics such as contact inhibition loss, telomerase activity, anchorage-independent growth, and changes in cytokine production. These results show that KSHV/HHV8, like other herpesviruses, can infect and replicate in epithelial cells in vitro and suggest that in vivo these cells may play a significant role in the establishment of KSHV/HHV8 infection and viral transmission.

Cerimele, Francesca; Curreli, Francesca; Ely, Scott; Friedman-Kien, Alvin E.; Cesarman, Ethel; Flore, Ornella

2001-01-01

110

Transcription factor regulation of epidermal keratinocyte gene expression  

Microsoft Academic Search

The epidermis is a tissue that undergoes a very complex and tightly controlled differentiation program. The elaboration of this program is generally flawless, resulting in the production of an effective protective barrier for the organism. Many of the genes expressed during keratinocyte differentiation are expressed in a coordinate manner; this suggests that common regulatory models may emerge. The simplest model

Richard L. Eckert; Jean F. Welter

1996-01-01

111

Human Keratinocyte Growth and Differentiation on Acellular Porcine Dermal Matrix in relation to Wound Healing Potential  

PubMed Central

A number of implantable biomaterials derived from animal tissues are now used in modern surgery. Xe-Derma is a dry, sterile, acellular porcine dermis. It has a remarkable healing effect on burns and other wounds. Our hypothesis was that the natural biological structure of Xe-Derma plays an important role in keratinocyte proliferation and formation of epidermal architecture in vitro as well as in vivo. The bioactivity of Xe-Derma was studied by a cell culture assay. We analyzed growth and differentiation of human keratinocytes cultured in vitro on Xe-Derma, and we compared the results with formation of neoepidermis in the deep dermal wounds treated with Xe-Derma. Keratinocytes cultured on Xe-Derma submerged in the culture medium achieved confluence in 7–10 days. After lifting the cultures to the air-liquid interface, the keratinocytes were stratified and differentiated within one week, forming an epidermis with basal, spinous, granular, and stratum corneum layers. Immunohistochemical detection of high-molecular weight cytokeratins (HMW CKs), CD29, p63, and involucrin confirmed the similarity of organization and differentiation of the cultured epidermal cells to the normal epidermis. The results suggest that the firm natural structure of Xe-Derma stimulates proliferation and differentiation of human primary keratinocytes and by this way improves wound healing.

Zajicek, Robert; Mandys, Vaclav; Mestak, Ondrej; Sevcik, Jan; Konigova, Radana; Matouskova, Eva

2012-01-01

112

Loss of serum response factor in keratinocytes results in hyperproliferative skin disease in mice  

PubMed Central

The transcription factor serum response factor (SRF) plays a crucial role in the development of several organs. However, its role in the skin has not been explored. Here, we show that keratinocytes in normal human and mouse skin expressed high levels of SRF but that SRF expression was strongly downregulated in the hyperproliferative epidermis of wounded and psoriatic skin. Keratinocyte-specific deletion within the mouse SRF locus during embryonic development caused edema and skin blistering, and all animals died in utero. Postnatal loss of mouse SRF in keratinocytes resulted in the development of psoriasis-like skin lesions. These lesions were characterized by inflammation, hyperproliferation, and abnormal differentiation of keratinocytes as well as by disruption of the actin cytoskeleton. Ultrastructural analysis revealed markedly reduced cell-cell and cell-matrix contacts and loss of cell compaction in all epidermal layers. siRNA-mediated knockdown of SRF in primary human keratinocytes revealed that the cytoskeletal abnormalities and adhesion defects were a direct consequence of the loss of SRF. In contrast, the hyperproliferation observed in vivo was an indirect effect that was most likely a consequence of the inflammation. These results reveal that loss of SRF disrupts epidermal homeostasis and strongly suggest its involvement in the pathogenesis of hyperproliferative skin diseases, including psoriasis.

Koegel, Heidi; von Tobel, Lukas; Schafer, Matthias; Alberti, Siegfried; Kremmer, Elisabeth; Mauch, Cornelia; Hohl, Daniel; Wang, Xiao-Jing; Beer, Hans-Dietmar; Bloch, Wilhelm; Nordheim, Alfred; Werner, Sabine

2009-01-01

113

Role of myocyte enhancing factor 2B in epithelial myofibroblast transition of human gingival keratinocytes.  

PubMed

It has recently emerged that the myogenic contribution of the epithelial mesenchymal transition plays a role in neoplastic invasion and metastasis. Myocyte enhancing factor 2B (MEF2B) is the only MEF2 isoform expressed during early embryonic development, and is herein proposed to transactivate the downstream target proteins of the epithelial myofibroblast transition (EMyT). We have previously generated eight preneoplastic cell lines with spindle and cobblestone morphology from human gingival mucosal keratinocytes immortalized by E6/E7 of human papillomavirus type 16. Spindle cells formed tubulogenic morphogenesis on Matrigel and exhibited contractility, anchorage-independent growth and invasiveness to a greater extent than cobblestone cells. Expression of MEF2B mRNA and myofibroblast proteins was higher in spindle cells compared with cobblestone cells. Epidermal growth factor (EGF) treatment of cobblestone cells also induced expression of these genes. Knockdown of MEF2B in a cobblestone cell line abolished EGF-induced upregulation of MEF2, vimentin and non-muscle caldesmon proteins, but enhanced basal expression of mesenchymal vimentin and fibronectin. Differential regulation of intermediate filaments revealed an unrecognized role of MEF2B in myogenic transformation of the epithelial to a myofibroblast phenotype, which occurs as epithelioid variants in some soft tissue sarcomas. PMID:22302709

Sun, Qiang; Sattayakhom, Apsorn; Backs, Johannes; Stremmel, Wolfgang; Chamulitrat, Walee

2012-02-02

114

Hypoxia-inducible factor-1alpha, a key factor in the keratinocyte response to UVB exposure.  

PubMed

Hypoxia-inducible factor-1 (HIF-1) is a major transcription factor sensitive to oxygen levels, which responds to stress factors under both hypoxic and nonhypoxic conditions. UV irradiation being a common stressor of skin, we looked at the effect of UVB on HIF-1alpha expression in keratinocytes. We found that UVB induces a biphasic HIF-1alpha variation through reactive oxygen species (ROS) generation. Whereas rapid production of cytoplasmic ROS down-regulates HIF-1alpha expression, delayed mitochondrial ROS generation results in its up-regulation. Indeed, activation of p38 MAPK and JNK1 mediated by mitochondrial ROS were required for HIF-1alpha phosphorylation and accumulation after UVB irradiation. Our experiments also revealed a key role of HIF-1alpha in mediating UVB-induced apoptosis. We conclude that the broad impact of the HIF-1 transcription factor on gene expression could make it a key regulator of UV-responsive genes and photocarcinogenesis. PMID:17400550

Rezvani, Hamid Reza; Dedieu, Sophie; North, Sophie; Belloc, Francis; Rossignol, Rodrigue; Letellier, Thierry; de Verneuil, Hubert; Taïeb, Alain; Mazurier, Frédéric

2007-03-30

115

Fish oil constituent docosahexa-enoic acid selectively inhibits growth of human papillomavirus immortalized keratinocytes  

Microsoft Academic Search

The omega-3-fatty acids inhibit proliferation of breast cancer cells whereas omega-6-fatty acids stimulate growth. In this study, we examined effects of these fatty acids on human pre-cancerous cells. Cervical keratinocytes, immortalized with the oncogenic human papillomavirus (HPV) type 16, were treated with linoleic acid, an omega- 6-fatty acid, and the omega-3-fatty acids, eicosapentaenoic and docosahexaenoic acids. Using both cell counts

DaZhi Chen; Karen Auborn

116

Keratinocyte serum-free medium maintains long-term liver gene expression and function in cultured rat hepatocytes by preventing the loss of liver-enriched transcription factors  

PubMed Central

Freshly isolated hepatocytes rapidly lose their differentiated properties when placed in culture. Therefore, production of a simple culture system for maintaining the phenotype of hepatocytes in culture would greatly facilitate their study. Our aim was to identify conditions that could maintain the differentiated properties of hepatocytes for up to 28 days of culture. Adult rat hepatocytes were isolated and attached in Williams’ medium E containing 10% serum. The medium was changed to either fresh Williams’ medium E or keratinocyte serum-free medium supplemented with dexamethasone, epidermal growth factor and pituitary gland extract. The hepatic phenotype was then analysed using RT-PCR, immunohistochemistry, Western blotting and assays of liver function. Cells cultured in keratinocyte serum-free medium supplemented with dexamethasone, epidermal growth factor and pituitary gland extract maintained their phenotype for 3–4 weeks, based on expression of liver proteins, ureagensis and response to xenobiotics. In contrast, hepatocytes cultured in Williams’ medium E rapidly lost the expression of liver proteins after 3 days. Cells cultured in keratinocyte serum-free medium supplemented with dexamethasone, epidermal growth factor and pituitary gland extract maintained their expression of liver-enriched transcription factors (C/EBP? and ?, HNF4? and RXR?) while expression was either lost or reduced in cells cultured in Williams’ medium E. These results suggest that keratinocyte serum-free medium supplemented with dexamethasone, epidermal growth factor and pituitary gland extract can maintain the hepatic phenotype for a prolonged period and that this is probably related to the continued expression of the liver-enriched transcription factors.

Li, Wan-Chun; Ralphs, Kate L.; Slack, Jonathan M.W.; Tosh, David

2007-01-01

117

Suppression of AP1 Transcription Factor Function in Keratinocyte Suppresses Differentiation  

PubMed Central

Our previous study shows that inhibiting activator protein one (AP1) transcription factor function in murine epidermis, using dominant-negative c-jun (TAM67), increases cell proliferation and delays differentiation. To understand the mechanism of action, we compare TAM67 impact in mouse epidermis and in cultured normal human keratinocytes. We show that TAM67 localizes in the nucleus where it forms TAM67 homodimers that competitively interact with AP1 transcription factor DNA binding sites to reduce endogenous jun and fos factor binding. Involucrin is a marker of keratinocyte differentiation that is expressed in the suprabasal epidermis and this expression requires AP1 factor interaction at the AP1-5 site in the promoter. TAM67 interacts competitively at this site to reduce involucrin expression. TAM67 also reduces endogenous c-jun, junB and junD mRNA and protein level. Studies with c-jun promoter suggest that this is due to reduced transcription of the c-jun gene. We propose that TAM67 suppresses keratinocyte differentiation by interfering with endogenous AP1 factor binding to regulator elements in differentiation-associated target genes, and by reducing endogenous c-jun factor expression.

Han, Bingshe; Rorke, Ellen A.; Adhikary, Gautam; Chew, Yap Ching; Xu, Wen; Eckert, Richard L.

2012-01-01

118

Role of Keratinocytes in the Development of Vitiligo  

PubMed Central

Vitiligo is an acquired depigmentary disorder of the skin that results from the loss of functioning epidermal melanocytes. Most studies on vitiligo have concentrated on the abnormality of melanocytes rather than the abnormality of keratinocytes; however, epidermal melanocytes form a functional and structural unit with neighboring keratinocytes. In fact, direct cell-to cell contact stimulates in vitro proliferation of melanocytes, and growth factors produced by adjacent keratinocytes regulate the proliferation and differentiation of melanocytes. The potential role of keratinocyte-derived cytokines has also been presented. We focused on the structural changes in vitiliginous keratinocytes, which may result in loss of melanocytes, to examine the pathomechanism of vitiligo. The results of a comparison between depigmented and normally pigmented epidermis in patients with vitiligo showed that the keratinocytes in the depigmented epidermis were more vulnerable to apoptosis. Impaired Phosphatidylinositol 3-kinase (PI3K)/serine/threonine protein kinase (Akt) activation followed by reduced nuclear factor-?B activation under increased tumor necrosis factor-? levels was demonstrated as a mechanism for keratinocyte apoptosis. The role of aquaporin 3 in keratinocyte apoptosis was addressed based on the relationship between the PI3K/AKT pathway and the E-cadherin-catenin complex. Apoptotic keratinocytes induced a lower expression of keratinocyte-derived factors, including stem cell factor, in depigmented epidermis, resulting in passive melanocyte death.

2012-01-01

119

Role of keratinocytes in the development of vitiligo.  

PubMed

Vitiligo is an acquired depigmentary disorder of the skin that results from the loss of functioning epidermal melanocytes. Most studies on vitiligo have concentrated on the abnormality of melanocytes rather than the abnormality of keratinocytes; however, epidermal melanocytes form a functional and structural unit with neighboring keratinocytes. In fact, direct cell-to cell contact stimulates in vitro proliferation of melanocytes, and growth factors produced by adjacent keratinocytes regulate the proliferation and differentiation of melanocytes. The potential role of keratinocyte-derived cytokines has also been presented. We focused on the structural changes in vitiliginous keratinocytes, which may result in loss of melanocytes, to examine the pathomechanism of vitiligo. The results of a comparison between depigmented and normally pigmented epidermis in patients with vitiligo showed that the keratinocytes in the depigmented epidermis were more vulnerable to apoptosis. Impaired Phosphatidylinositol 3-kinase (PI3K)/serine/threonine protein kinase (Akt) activation followed by reduced nuclear factor-?B activation under increased tumor necrosis factor-? levels was demonstrated as a mechanism for keratinocyte apoptosis. The role of aquaporin 3 in keratinocyte apoptosis was addressed based on the relationship between the PI3K/AKT pathway and the E-cadherin-catenin complex. Apoptotic keratinocytes induced a lower expression of keratinocyte-derived factors, including stem cell factor, in depigmented epidermis, resulting in passive melanocyte death. PMID:22577260

Lee, Ai-Young

2012-04-26

120

Expression of the human papillomavirus type 16 E7 oncoprotein induces an autophagy-related process and sensitizes normal human keratinocytes to cell death in response to growth factor deprivation  

SciTech Connect

Expression of oncogenes, such as the human papillomavirus type 16 (HPV16) E7 oncoprotein, promotes aberrant cell proliferation. In the absence of concurrent mitogenic stimuli, this triggers a cell-intrinsic defense mechanism, the 'trophic sentinel response', which eliminates such aberrant cells. The molecular pathways that elicit this response, however, remain obscure. We set up an experimental system to investigate the trophic sentinel pathway triggered by HPV16 E7 expression in normal human keratinocytes, the natural host cells of HPVs. Keratinocytes expressing HPV16 E7 cultured in E-medium undergo cell death and show increased sub-G1 DNA content when grown to confluence or under conditions of serum deprivation. Moreover, HPV16 E7 expressing human keratinocytes express higher levels of the autophagy marker, LC3-II, which can be abrogated by 3-methyladenine, an autophagy inhibitor. These findings indicate that even under normal culture conditions, HPV16 E7 expression triggers metabolic stress that may result in autophagy, a pathway implicated in carcinogenesis.

Zhou Xiaobo [Infectious Diseases Division, Channing Laboratories, Brigham and Women's Hospital and Department of Medicine, Harvard Medical School (United States); Muenger, Karl [Infectious Diseases Division, Channing Laboratories, Brigham and Women's Hospital and Department of Medicine, Harvard Medical School (United States)], E-mail: kmunger@rics.bwh.harvard.edu

2009-03-01

121

[Modifications in cultivating gingival keratinocytes].  

PubMed

Gingival keratinocyte grafts are usually cultured using 3T3 mouse fibroblasts as feeder cells and fetal calf serum as growth factor. These additives entail risks due to xenogenic DNA and protein. Therefore the explant and the disperse culture technique free of feeder cells were compared, and autogenous human serum was tested. Twelve halved gingival biopsies were trypsinized and cultured as single-cell suspensions, the other halves were cultured as explants. Six halved biopsies were cultured in autogenous serum, the other halves in fetal calf serum. Growth, morphology and cell biological aspects were compared. The single-cell suspensions did not form a confluent epithelial layer, whereas all explants formed confluent primary gingival keratinocyte cultures. The keratinocytes' growth in autogenous serum was equivalent to that in fetal calf serum. Morphology and cytokeratin expression were identical. The explant technique combined with autogenous serum can be used for culturing gingival autografts as well as for individual cultures for special issues. PMID:9483925

Lauer, G; Otten, J E; Schilli, W

1997-02-01

122

Growth factors and cytokines in wound healing.  

PubMed

Wound healing is an evolutionarily conserved, complex, multicellular process that, in skin, aims at barrier restoration. This process involves the coordinated efforts of several cell types including keratinocytes, fibroblasts, endothelial cells, macrophages, and platelets. The migration, infiltration, proliferation, and differentiation of these cells will culminate in an inflammatory response, the formation of new tissue and ultimately wound closure. This complex process is executed and regulated by an equally complex signaling network involving numerous growth factors, cytokines and chemokines. Of particular importance is the epidermal growth factor (EGF) family, transforming growth factor beta (TGF-beta) family, fibroblast growth factor (FGF) family, vascular endothelial growth factor (VEGF), granulocyte macrophage colony stimulating factor (GM-CSF), platelet-derived growth factor (PDGF), connective tissue growth factor (CTGF), interleukin (IL) family, and tumor necrosis factor-alpha family. Currently, patients are treated by three growth factors: PDGF-BB, bFGF, and GM-CSF. Only PDGF-BB has successfully completed randomized clinical trials in the Unites States. With gene therapy now in clinical trial and the discovery of biodegradable polymers, fibrin mesh, and human collagen serving as potential delivery systems other growth factors may soon be available to patients. This review will focus on the specific roles of these growth factors and cytokines during the wound healing process. PMID:19128254

Barrientos, Stephan; Stojadinovic, Olivera; Golinko, Michael S; Brem, Harold; Tomic-Canic, Marjana

123

Nrf Transcription Factors in Keratinocytes Are Essential for Skin Tumor Prevention but Not for Wound Healing  

Microsoft Academic Search

The Nrf2 transcription factor is a key player in the cellular stress response through its regulation of cytoprotective genes. In this study we determined the role of Nrf2-mediated gene expression in keratinocytes for skin development, wound repair, and skin carcinogenesis. To overcome compensation by the related Nrf1 and Nrf3 proteins, we expressed a dominant-negative Nrf2 mutant (dnNrf2) in the epidermis

U. auf dem Keller; M. Huber; T. A. Beyer; A. Kumin; C. Siemes; S. Braun; P. Bugnon; V. Mitropoulos; D. A. Johnson; J. A. Johnson; D. Hohl; S. Werner

2006-01-01

124

Tumor necrosis factor-? decreases aquaporin-3 expression in DJM-1 keratinocytes  

Microsoft Academic Search

Aquaporin-3 (AQP3) is a water\\/glycerol-transporting protein that is strongly expressed at the plasma membranes of keratinocytes in skin. There is evidence for involvement of AQP3-facilitated water and glycerol transport in skin hydration and wound repair, respectively. In this study, we show that tumor necrosis factor-? (TNF-?) and TNF receptor-1 signaling decreased AQP3 protein expression and plasma membrane water permeability in

Ichiro Horie; Mamiko Maeda; Satoshi Yokoyama; Akinori Hisatsune; Hiroshi Katsuki; Takeshi Miyata; Yoichiro Isohama

2009-01-01

125

Tumor necrosis factor beta and ultraviolet radiation are potent regulators of human keratinocyte ICAM-1 expression  

SciTech Connect

Intercellular adhesion molecule-1 (ICAM-1) functions as a ligand of leukocyte function-associated antigen-1 (LFA-1), as well as a receptor for human picorna virus, and its regulation thus affects various immunologic and inflammatory reactions. The weak, constitutive ICAM-1 expression on human keratinocytes (KC) can be up-regulated by cytokines such as interferon-gamma (IFN gamma) and tumor necrosis factor alpha (TNF alpha). In order to further examine the regulation of KC ICAM-1 expression, normal human KC or epidermoid carcinoma cells (KB) were incubated with different cytokines and/or exposed to ultraviolet (UV) radiation. Subsequently, ICAM-1 expression was monitored cytofluorometrically using a monoclonal anti-ICAM-1 antibody. Stimulation of cells with recombinant human (rh) interleukin (IL) 1 alpha, rhIL-4, rhIL-5, rhIL-6, rh granulocyte/macrophage colony-stimulating factor (GM-CSF), rh interferon alpha (rhIFN alpha), and rh transforming growth factor beta (TGF beta) did not increase ICAM-1 surface expression. In contrast, rhTNF beta significantly up-regulated ICAM-1 expression in a time- and dose-dependent manner. Moreover, the combination of rhTNF beta with rhIFN gamma increased the percentage of ICAM-1-positive KC synergistically. This stimulatory effect of rhTNF beta was further confirmed by the demonstration that rhTNF beta was capable of markedly enhancing ICAM-1 mRNA expression in KC. Finally, exposure of KC in vitro to sublethal doses of UV radiation (0-100 J/m2) prior to cytokine (rhIFN tau, rhTNF alpha, rhTNF beta) stimulation inhibited ICAM-1 up-regulation in a dose-dependent fashion. These studies identify TNF beta and UV light as potent regulators of KC ICAM-1 expression, which may influence both attachment and detachment of leukocytes and possibly viruses to KC.

Krutmann, J.; Koeck, A.S.; Schauer, E.; Parlow, F.; Moeller, A.K.; Kapp, A.; Foerster, E.S.; Schoepf, E.L.; Luger, T.A. (Univ. of Freiburg (Germany, F.R.))

1990-08-01

126

Plant polyphenols differentially modulate inflammatory responses of human keratinocytes by interfering with activation of transcription factors NF?B and AhR and EGFR-ERK pathway.  

PubMed

Molecular mechanisms underlying modulation of inflammatory responses in primary human keratinocytes by plant polyphenols (PPs), namely the glycosylated phenylpropanoid verbascoside, the stilbenoid resveratrol and its glycoside polydatin, and the flavonoid quercetin and its glycoside rutin were evaluated. As non-lethal stimuli, the prototypic ligand for epidermal growth factor receptor (EGFR) transforming growth factor alpha (TGFalpha), the combination of tumor necrosis factor (TNFalpha) and interferon (IFNgamma) (T/I), UVA+UVB irradiation, and bacterial lipopolysaccharide (LPS) were used. We demonstrated differential modulation of inflammatory responses in keratinocytes at signal transduction, gene transcription, and protein synthesis levels as a function of PP chemical structure, the pro-inflammatory trigger used, and PP interaction with intracellular detoxifying systems. The PPs remarkably inhibited constitutive, LPS- and T/I-induced but not TGFalpha-induced ERK phosphorylation. They also suppressed NFkappaB activation by LPS and T/I. Verbascoside and quercetin invariably impaired EGFR phosphorylation and UV-associated aryl hydrocarbon receptor (AhR)-mediated signaling, while rutin, polydatin and resveratrol did not affect EGFR phosphorylation and further activated AhR machinery in UV-exposed keratinocytes. In general, PPs down-regulated gene expression of pro-inflammatory cytokines/enzymes, except significant up-regulation of IL-8 observed under stimulation with TGFalpha. Both spontaneous and T/I-induced release of IL-8 and IP-10 was suppressed, although 50?M resveratrol and polydatin up-regulated IL-8. At this concentration, resveratrol activated both gene expression and de novo synthesis of IL-8 and AhR-mediated mechanisms were involved. We conclude that PPs differentially modulate the inflammatory response of human keratinocytes through distinct signal transduction pathways, including AhR and EGFR. PMID:21756928

Potapovich, Alla I; Lulli, Daniela; Fidanza, Paolo; Kostyuk, Vladimir A; De Luca, Chiara; Pastore, Saveria; Korkina, Liudmila G

2011-07-12

127

Alteration and Significance of Heparin-Binding Epidermal-Growth-Factor-Like Growth Factor in Psoriatic Epidermis  

Microsoft Academic Search

Background: Heparin-binding epidermal-growth-factor-like growth factor (HB-EGF) has proved to be a mitogen of keratinocytes, which may be involved in the pathogenesis of inflammatory diseases, but its mechanism in psoriasis remains unknown. Objective: To investigate the alteration of HB-EGF in the epidermis of active psoriasis vulgaris. Methods: The expression of HB-EGF in normal skin tissues, uninvolved tissues and psoriatic lesions was

Yan Zheng; Zhenhui Peng; Yili Wang; Shengshun Tan; Yanping Xi; Guorong Wang

2003-01-01

128

A murine monoclonal antibody (VM-1) against human basal cells inhibits the growth of human keratinocytes in culture.  

PubMed

Using epidermal cells from psoriatic plaques as the immunogen, an IgG1 murine monoclonal antibody, VM-1, has been produced which stains basal keratinocytes on frozen sections of skin obtained from normal individuals and from psoriatic plaques. In some areas of both normal and psoriatic epidermis, the cell layer immediately above the basal cells is also stained. Cells in the external root sheath of the hair follicles also bind VM-1. The antibody binding site is trypsin-resistant, and is not blocked by bullous pemphigoid serum. If dispersed epidermal cells are preincubated with VM-1 for 1 h or more before plating, the majority of the cells do not attach and spread out on a collagen-coated Petri dish surface or on a fibroblast feeder layer. When added to attached, preconfluent cultures of keratinocytes, VM-1 inhibits growth and alters cell morphology. The growth inhibition is specific for keratinocytes, and viability studies show that it is not due to an immediate toxic effect of the antibody. The VM-1-induced inhibition of keratinocyte growth is not reversed by soy bean or lima bean trypsin inhibitors added at the time of cell plating or at the time of addition of antibody. PMID:3981036

Oseroff, A R; Pfendt, E A; DiCicco, L; Morhenn, V B

1985-04-01

129

Differentiation-specific transcriptional regulation of the ESE-2 gene by a novel keratinocyte-restricted factor.  

PubMed

Epithelium specific Ets-2 (ESE-2), an epithelium-specific ETS-domain transcription factor, is highly expressed in differentiated keratinocytes. To understand the molecular mechanisms that govern the cell-type and differentiation-specific expression of ESE-2 in keratinocytes, we have focused our studies on the identification and characterization of its cis-regulatory elements. We first performed DNase I hypersensitive site mapping and demonstrated that the promoter region of ESE-2 is in open chromatin conformation in differentiated keratinocytes. Next, we performed transient transfection assays with several 5' serially deleted constructs containing segments of the ESE-2 promoter. These experiments have led to the identification of a short fragment that shows remarkable sequence conservation between several species and harbors most of the transcriptional activity. Interestingly, a high level of transcriptional activity was only observed when the transfected keratinocytes were induced to differentiate by increasing the calcium concentration in the cell-culture medium. To identify the factors that mediate the transcriptional activity, we analyzed this segment by mutational and electrophoretic mobility shift assays (EMSA) experiments. Our studies have identified a critical stretch of nucleotides that is important for both basal as well as calcium responsive reporter activity and that binds to a nuclear factor, keratinocyte restricted factor (KRF). KRF is a novel transcription factor that is restricted to nuclear extracts isolated from keratinocytes and that binds to unique DNA sequences, which do not resemble any known consensus binding motif for transcription factors. Our preliminary experiments shed light on the biochemical nature of KRF and set the stage for future studies in identification of KRF and testing its role in governing ESE-2 gene expression in vivo. PMID:16229011

Tummala, Ramakumar; Sinha, Satrajit

2006-03-01

130

Ligand Activation of Peroxisome Proliferator-Activated Receptor-?/? (PPAR?/?) Inhibits Cell Growth of Human N/TERT-1 Keratinocytes  

PubMed Central

The functional role of peroxisome proliferator-activated receptor-? (PPAR?; also referred to as PPAR?) in epidermal cell growth remains controversial. Recent evidence suggests that ligand activation of PPAR?/? increases cell growth and inhibits apoptosis in epidermal cells. In contrast, other reports suggest that ligand activation of PPAR?/? leads to the induction of terminal differentiation and inhibition of cell growth. In the present study, the effect of the highly specific PPAR?/? ligand GW0742 on cell growth was examined using a human keratinocyte cell line (N/TERT-1) and mouse primary keratinocytes. Ligand activation of PPAR?/? with GW0742 prevented cell cycle progression from G1 to S phase and attenuated cell proliferation in N/TERT-1 cells. Despite specifically activating PPAR?/? as revealed by target gene induction, no changes in PTEN, PDK and ILK expression or downstream phosphorylation of Akt were found in either N/TERT-1 cells or primary keratinocytes. Further, altered cell growth resulting from serum withdrawal and the induction of caspase-3 activity by ultraviolet radiation were unchanged in the absence of PPAR?/? expression and/or the presence of GW0742. While no changes in the expression of mRNAs encoding cell cycle control proteins were found in response to GW0742, a significant decrease in the level of ERK phosphorylation was observed. Results from these studies demonstrate that ligand activation of PPAR?/? does not lead to an anti-apoptotic effect in either human or mouse keratinocytes, but rather, leads to inhibition of cell growth likely through the induction of terminal differentiation.

Burdick, Andrew D.; Bility, Moses T.; Girroir, Elizabeth E.; Billin, Andrew N.; Willson, Timothy M.; Gonzalez, Frank J.; Peters, Jeffrey M.

2007-01-01

131

Tumor necrosis factor-alpha decreases aquaporin-3 expression in DJM-1 keratinocytes.  

PubMed

Aquaporin-3 (AQP3) is a water/glycerol-transporting protein that is strongly expressed at the plasma membranes of keratinocytes in skin. There is evidence for involvement of AQP3-facilitated water and glycerol transport in skin hydration and wound repair, respectively. In this study, we show that tumor necrosis factor-alpha (TNF-alpha) and TNF receptor-1 signaling decreased AQP3 protein expression and plasma membrane water permeability in DJM-1 keratinocytes. TNF-alpha also decreased AQP3 mRNA expression and promoter activity, indicating that TNF-alpha suppresses AQP3 gene transcription. In addition, inhibitors of p38 and extracellular signal-regulated kinase (ERK) abolished the effect of TNF-alpha on AQP3 expression level, whereas inhibitors for NF-kappaB did not. These data indicate that TNF-alpha decreases AQP3 gene expression through p38 and ERK activation, and suggest that the decrease in AQP3 expression caused by TNF-alpha might be related to the phenotypes of skin inflammation, such as dry skin. PMID:19619514

Horie, Ichiro; Maeda, Mamiko; Yokoyama, Satoshi; Hisatsune, Akinori; Katsuki, Hiroshi; Miyata, Takeshi; Isohama, Yoichiro

2009-07-18

132

Assessment of Optimal Virus-Mediated Growth Factor Gene Delivery for Human Cutaneous Wound Healing Enhancement  

Microsoft Academic Search

Using a recently described skin-humanized model based on the engraftment of human bioengineered skin equivalents onto immunodeficient mice, we compared the efficacy of different in vivo gene transfer strategies aimed at delivering growth factors to promote skin wound healing. The approaches involving transient delivery of keratinocyte growth factor (KGF) to wounds performed in the engrafted human skin included (1) KGF

María J Escámez; Marta Carretero; Marta García; Lucía Martínez-Santamaría; Isabel Mirones; Blanca Duarte; Almudena Holguín; Eva García; Verónica García; Alvaro Meana; José L Jorcano; Fernando Larcher; Marcela Del Río

2008-01-01

133

Interleukin1-stimulated Secretion of Interleukin8 and Growth-related Oncogene-? Demonstrates Greatly Enhanced Keratinocyte Growth in Human Raft Cultured Epidermis  

Microsoft Academic Search

The CXC chemokines, interleukin-8 and growth-related oncogene?, are known to play a prominent part in wound healing as well as inflammatory skin disorders, including psoriasis. Both chemokines are potent neutrophil activators and were discussed as potential stimuli in keratinocyte growth. We examined the action of growth-related oncogene ? and interleukin-8 in organotypic raft culture, which resembles in vivo skin in

Judith Steude; Reinhard Kulke; Enno Christophers

2002-01-01

134

Fibroblast growth factors  

Microsoft Academic Search

SUMMARY: Fibroblast growth factors (FGFs) make up a large family of polypeptide growth factors that are found in organisms ranging from nematodes to humans. In vertebrates, the 22 members of the FGF family range in molecular mass from 17 to 34 kDa and share 13-71% amino acid identity. Between vertebrate species, FGFs are highly conserved in both gene structure and

David M Ornitz; Nobuyuki Itoh

2001-01-01

135

Intracellular free calcium and growth changes in single human keratinocytes in response to vitamin D and five 20-epi-analogues  

Microsoft Academic Search

Vitamin D, 1,25(OH)2D3, decreases proliferation and promotes differentiation of keratinocytes, and other keratinocyte differentiation stimuli have been associated with an early rise in intracellular free calcium, [Ca2+]i. We therefore investigated the effect of 1,25(OH)2D3, its precursor D3 and five 20-epi-analogues (EB1089, KH1060, KH1139, MC1288, MC1301) on growth and [Ca2+]i levels of normal human keratinocytes. Cells were cultured in medium MCDB153

K. T. Jones; G. R. Sharpe

1994-01-01

136

Interleukin 7 is produced by murine and human keratinocytes  

PubMed Central

Interleukin 7 (IL-7) was originally identified as a growth factor for B cell progenitors, and subsequently has been shown to exert proliferative effects on T cell progenitors and mature peripheral T cells as well. Constitutive IL-7 mRNA expression so far had been demonstrated in bone marrow stromal cell lines, thymus, spleen, and among nonlymphoid tissues in liver and kidney. Here we show that both murine and human keratinocytes express IL-7 mRNA and release IL-7 protein in biologically relevant amounts. The physiological or pathological relevance of keratinocyte-derived IL-7 is presently unknown. Our finding that keratinocytes can produce IL-7 in concert with reports that IL-7 is a growth factor for in vivo primed antigen- specific T cells, as well as for T lymphoma cells suggests, however, that keratinocyte-derived IL-7 is important in the pathogenesis of inflammatory skin diseases and cutaneous T cell lymphoma.

1993-01-01

137

FGF growth factor analogs  

SciTech Connect

The present invention provides a fibroblast growth factor heparin-binding analog of the formula: ##STR00001## where R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, X, Y and Z are as defined, pharmaceutical compositions, coating compositions and medical devices including the fibroblast growth factor heparin-binding analog of the foregoing formula, and methods and uses thereof.

Zamora, Paul O. (Gaithersburg, MD); Pena, Louis A. (Poquott, NY); Lin, Xinhua (Plainview, NY); Takahashi, Kazuyuki (Germantown, MD)

2012-07-24

138

Peptide growth factors, part A  

SciTech Connect

This book contains information on the following topics: Epidermal Growth Factor;Transforming Growth Factors;Bone and Cartilage Growth Factors;Somatomedin/Insulin-Like Growth Factors;Techniques for the Study of Growth Factor Activity;Assays, Phosphorylation, and Surface Membrane Effects.

Barnes, D.; Sirbasku, D.A.

1987-01-01

139

Hypoxia-inducible factor-1? regulates the expression of nucleotide excision repair proteins in keratinocytes  

PubMed Central

The regulation of DNA repair enzymes is crucial for cancer prevention, initiation, and therapy. We have studied the effect of ultraviolet B (UVB) radiation on the expression of the two nucleotide excision repair factors (XPC and XPD) in human keratinocytes. We show that hypoxia-inducible factor-1? (HIF-1?) is involved in the regulation of XPC and XPD. Early UVB-induced downregulation of HIF-1? increased XPC mRNA expression due to competition between HIF-1? and Sp1 for their overlapping binding sites. Late UVB-induced enhanced phosphorylation of HIF-1? protein upregulated XPC mRNA expression by direct binding to a separate hypoxia response element (HRE) in the XPC promoter region. HIF-1? also regulated XPD expression by binding to a region of seven overlapping HREs in its promoter. Quantitative chromatin immunoprecipitation assays further revealed putative HREs in the genes encoding other DNA repair proteins (XPB, XPG, CSA and CSB), suggesting that HIF-1? is a key regulator of the DNA repair machinery. Analysis of the repair kinetics of 6-4 photoproducts and cyclobutane pyrimidine dimers also revealed that HIF-1? downregulation led to an increased rate of immediate removal of both photolesions but attenuated their late removal following UVB irradiation, indicating the functional effects of HIF-1? in the repair of UVB-induced DNA damage.

Rezvani, Hamid Reza; Mahfouf, Walid; Ali, Nsrein; Chemin, Cecile; Ged, Cecile; Kim, Arianna L.; de Verneuil, Hubert; Taieb, Alain; Bickers, David R.; Mazurier, Frederic

2010-01-01

140

New thrombopoietic growth factors  

PubMed Central

Although development of first-generation thrombopoietic growth factors (recombinant human thrombopoietin [TPO] and pegylated recombinant human megakaryocyte growth and development factor [PEG-rHuMGDF]) was stopped due to development of antibodies to PEG-rHuMGDF, nonimmunogenic second-generation thrombopoietic growth factors with unique pharmacologic properties have been developed. TPO peptide mimetics contain TPO receptor-activating peptides inserted into complementarity-determining regions of Fab (Fab 59), attached to the IgG Fc region (AMG 531), or pegylated (Peg-TPOmp). Orally available, TPO nonpeptide mimetics (eltrombopag, AKR-501) bind and activate the TPO receptor by a mechanism different from TPO and may have an additive effect to TPO. TPO agonist antibodies are monoclonal antibodies activating the TPO receptor but modified in size [TPO minibodies; ie, VB22B sc(Fv)2] or immunoglobuln type (domain subclass-converted TPO agonist antibodies; ie, MA01G4G344). All second-generation thrombopoietic growth factors stimulate growth of TPO-dependent cell lines via JAK2/STAT signaling pathways and increase platelet counts in animals. When tested in healthy humans, TPO peptide and nonpeptide mimetics produced a dose-dependent rise in platelet count. AMG 531 and eltrombopag markedly increase platelet counts in patients with immune thrombocytopenic purpura, without significant adverse effects. One or more second-generation thrombopoietic growth factors should soon be clinically available for treating thrombocytopenic disorders.

2007-01-01

141

Tanshinone IIA Inhibits Growth of Keratinocytes through Cell Cycle Arrest and Apoptosis: Underlying Treatment Mechanism of Psoriasis  

PubMed Central

The aim of the present investigation was to elucidate the cellular mechanisms whereby Tanshinone IIA (Tan IIA) leads to cell cycle arrest and apoptosis in vitro in keratinocytes, the target cells in psoriasis. Tan IIA inhibited proliferation of mouse keratinocytes in a dose- and time-dependent manner and induced apoptosis, resulting in S phase arrest accompanied by down-regulation of pCdk2 and cyclin A protein expression. Furthermore, Tan IIA-induced apoptosis and mitochondrial membrane potential changes were also further demonstrated by DNA fragmentation, single-cell gel electrophoresis assay (SCGE), and flow cytometry methods. Apoptosis was partially blocked by the caspase-3 inhibitor Ac-DEVD-CHO. Mitochondrial regulation of apoptosis further downstream was investigated, showing changes in the mitochondrial membrane potential, cytochrome c release into the cytoplasm, and enhanced activation of cleaved caspase-3 and Poly ADP-ribose polymerase (PARP). There was also no translocation of apoptosis-inducing factor (AIF) from mitochondria to the nucleus in apoptotic keratinocytes, indicating Tan IIA-induced apoptosis occurs mainly through the caspase pathway. Our findings provide the molecular mechanisms by which Tan IIA can be used to treat psoriasis and support the traditional use of Salvia miltiorrhiza Bungee (Labiatae) for psoriasis and related skin diseases.

Li, Fu-Lun; Xu, Rong; Zeng, Qing-chun; Li, Xin; Chen, Jie; Wang, Yi-Fei; Fan, Bin; Geng, Lin; Li, Bin

2012-01-01

142

Platelet activating factor stimulates arachidonic acid release in differentiated keratinocytes via arachidonyl non-selective phospholipase A 2  

Microsoft Academic Search

Platelet activating factor (PAF, 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) is known to be present in excess in psoriatic skin, but its exact role is uncertain. In the present\\u000a study we demonstrate for the first time the role of group VI PLA2 in PAF-induced arachidonic acid release in highly differentiated human keratinocytes. The group IV? PLA2 also participates in the release, while secretory PLA2s play

Katarina Mariann Jørgensen; Hanne Solvang Felberg; Rolf K. Berge; Astrid Lægreid; Berit Johansen

2010-01-01

143

Thapsigargin Induces Rapid, Transient Growth Inhibition and c-fos Expression Followed by Sustained Growth Stimulation in Mouse Keratinocyte Cultures  

Microsoft Academic Search

Although the sesquiterpene lactone thapsigargin has been shown to possess hyperplastic and tumor-promoting activities when applied topically to mouse skin in vivo, the cellular mechanism(s) which underlie these effects are unclear. We show here that thapsigargin treatment of primary mouse epidermal keratinocytes increased intracellular free Ca2+ concentration (Cai) in a concentration-dependent manner. Thapsigargin induced a rapid, transient elevation in keratinocyte

Charles S. Harmon; Janet Ducote; Yimin Xiong

1996-01-01

144

The effect of three Korean traditional medicines on the growth rate of cultured human keratinocytes  

Microsoft Academic Search

The effect of three different Korean Traditional Medicines (KTM) was studied on several functional parameters of adult human cells in culture. The cells were non-transformed strains of normal, skin epidermal cells (keratinocytes) from adult humans. Aqueous extracts of the herbal medicines were tested using two types of cell strains: one type was essential fatty acid deficient (EFAD) cells which grow

Seok Hee Chung; Hiroto Terashi; Lenore M Rhodes; Namdoo Moon; William R Dunham; Cynthia L Marcelo

2001-01-01

145

Stathmin Regulates Keratinocyte Proliferation and Migration during Cutaneous Regeneration.  

PubMed

Cutaneous regeneration utilizes paracrine feedback mechanisms to fine-tune the regulation of epidermal keratinocyte proliferation and migration. However, it is unknown how fibroblast-derived hepatocyte growth factor (HGF) affects these mutually exclusive processes in distinct cell populations. We here show that HGF stimulates the expression and phosphorylation of the microtubule-destabilizing factor stathmin in primary human keratinocytes. Quantitative single cell- and cell population-based analyses revealed that basal stathmin levels are important for the migratory ability of keratinocytes in vitro; however, its expression is moderately induced in the migration tongue of mouse skin or organotypic multi-layered keratinocyte 3D cultures after full-thickness wounding. In contrast, clearly elevated stathmin expression is detectable in hyperproliferative epidermal areas. In vitro, stathmin silencing significantly reduced keratinocyte proliferation. Automated quantitative and time-resolved analyses in organotypic cocultures demonstrated a high correlation between Stathmin/phospho-Stathmin and Ki67 positivity in epidermal regions with proliferative activity. Thus, activation of stathmin may stimulate keratinocyte proliferation, while basal stathmin levels are sufficient for keratinocyte migration during cutaneous regeneration. PMID:24066165

Schmitt, Sabrina; Safferling, Kai; Westphal, Kathi; Hrabowski, Manuel; Müller, Ute; Angel, Peter; Wiechert, Lars; Ehemann, Volker; Müller, Benedikt; Holland-Cunz, Stefan; Stichel, Damian; Harder, Nathalie; Rohr, Karl; Germann, Günter; Matthäus, Franziska; Schirmacher, Peter; Grabe, Niels; Breuhahn, Kai

2013-09-16

146

Stathmin Regulates Keratinocyte Proliferation and Migration during Cutaneous Regeneration  

PubMed Central

Cutaneous regeneration utilizes paracrine feedback mechanisms to fine-tune the regulation of epidermal keratinocyte proliferation and migration. However, it is unknown how fibroblast-derived hepatocyte growth factor (HGF) affects these mutually exclusive processes in distinct cell populations. We here show that HGF stimulates the expression and phosphorylation of the microtubule-destabilizing factor stathmin in primary human keratinocytes. Quantitative single cell- and cell population-based analyses revealed that basal stathmin levels are important for the migratory ability of keratinocytes in vitro; however, its expression is moderately induced in the migration tongue of mouse skin or organotypic multi-layered keratinocyte 3D cultures after full-thickness wounding. In contrast, clearly elevated stathmin expression is detectable in hyperproliferative epidermal areas. In vitro, stathmin silencing significantly reduced keratinocyte proliferation. Automated quantitative and time-resolved analyses in organotypic cocultures demonstrated a high correlation between Stathmin/phospho-Stathmin and Ki67 positivity in epidermal regions with proliferative activity. Thus, activation of stathmin may stimulate keratinocyte proliferation, while basal stathmin levels are sufficient for keratinocyte migration during cutaneous regeneration.

Schmitt, Sabrina; Safferling, Kai; Westphal, Kathi; Hrabowski, Manuel; Muller, Ute; Angel, Peter; Wiechert, Lars; Ehemann, Volker; Muller, Benedikt; Holland-Cunz, Stefan; Stichel, Damian; Harder, Nathalie; Rohr, Karl; Germann, Gunter; Matthaus, Franziska; Schirmacher, Peter; Grabe, Niels; Breuhahn, Kai

2013-01-01

147

New Advances on the Functions of Epidermal Growth Factor Receptor and Ceramides in Skin Cell Differentiation, Disorders and Cancers  

Microsoft Academic Search

Recent advances in understanding of the biological functions of the epidermal growth factor and epidermal growth factor receptor (EGF-EGFR) system and ceramide production for the maintenance of skin integrity and barrier function are reported. In particular, the opposite roles of EGFR and ceramide cascades in epithelial keratinocyte proliferation, migration and terminal differentiation are described. Moreover, the functions of ceramides in

M. Mimeault; D. Bonenfant; S. K. Batra

2004-01-01

148

Role of Growth Factors, Cytokines, and Their Receptors in the Pathogenesis of Psoriasis  

Microsoft Academic Search

Psoriasis is characterized by epidermal hyperplasia, altered epidermal maturation, and local accumulation of acute and chronic inflammatory cells. Keratinocyte hyperplasia in psoriasis may be explained in part by overproduction of growth factors or cytokines which stimulate epidermal proliferation and by altered metabolism of growth-factor receptors in affected skin. Psoriatic epidermis displays overproduction of TGF-alpha and interleukin-6 (IL-6), factors produced by

James G. Krueger; Jeffrey F. Krane; D. Martin Carter; Alice B. Gottlieb

1990-01-01

149

Augmentation of Granulocyte\\/Macrophage Colony-Stimulating Factor Expression by Ultraviolet Irradiation Is Mediated by Interleukin 1 in Pam 212 Keratinocytes  

Microsoft Academic Search

Keratinocytes are a potent source of a variety of cytokines including granulocyte-macrophage colony-stimulating factor (GM-CSF). In this study, we have shown that ultraviolet B (UVB) irradiation augments GM-CSF mRNA expression by murine keratinocytes. This is reflected in the increased production of GM-CSF protein by these cells. In the same cell population, exposure to UVB irradiation increases interleukin 1? (IL-1?) mRNA

Shigeyuki Nozaki; John S. Abrams; Michael K. Pearce; Daniel N. Sauder

1991-01-01

150

Growth regulation of skin cells by epidermal cell-derived factors: implications for wound healing.  

PubMed Central

Epidermal cell-derived factors (EDF), present in extracts and supernatant fluids of cultured epidermal cells, were found to stimulate the proliferation of keratinocytes but to inhibit fibroblasts. In vitro, the effect of EDF on epidermal cells resulted in an increased number of rapidly proliferating colonies composed mainly of basal keratinocytes. Control cultures grown in the absence of EDF had a high proportion of terminally differentiated cells. In fibroblast cultures EDF inhibited the ability of fibroblasts to cause contraction of collagen sponges by 90%. Epidermal growth factor, basic fibroblast growth factor, platelet-derived growth factor, transforming growth factor beta, nerve growth factor, and extracts of WI-38 cells (human embryonic lung fibroblasts) did not have this inhibitory activity. Application of EDF to surgical wounds stimulated extensive migration and proliferation of keratinocytes from remnants of glands, hair follicles, and wound edges. The restoration of complete epidermal coverage of wounds treated with EDF occurred twice as rapidly as that of control wounds. In addition, regenerating dermis in the EDF-treated wounds contained 1/5th to 1/15th as many cells as wounds treated with epidermal growth factor, urogastrone, transforming growth factor, or phosphate-buffered saline. The use of EDF to enhance re-epithelization and to prevent scar formation is proposed. Images

Eisinger, M; Sadan, S; Silver, I A; Flick, R B

1988-01-01

151

Do nerve growth factor-related mechanisms contribute to loss of cutaneous nociception in leprosy?  

Microsoft Academic Search

While sensory loss in leprosy skin is the consequence of invasion by M. leprae of Schwann cells related to unmyelinated fibres, early loss of cutaneous pain sensation, even in the presence of nerve fibres and inflammation, is a hallmark of leprosy, and requires explanation. In normal skin, nerve growth factor (NGF) is produced by basal keratinocytes, and acts via its

Paul Facer; Dawn Mann; Rajeev Mathur; Shubha Pandya; Uma Ladiwala; Bhim Singhal; Jo-Anne Hongo; Dominick V Sinicropi; Giorgio Terenghi; Praveen Anand

2000-01-01

152

cis-Urocanic acid stimulates primary human keratinocytes independently of serotonin or platelet-activating factor receptors.  

PubMed

Urocanic acid (UCA) is a major epidermal chromophore that undergoes trans to cis isomerization after ultraviolet radiation (UVR). cis-UCA suppresses cell-mediated immunity. Recent studies suggest that cis-UCA binds to serotonin (5-hydroxytryptamine) 2A (5-HT(2A)) receptor and that antagonists of 5-HT(2A) and the platelet-activating factor (PAF) receptor can block cis-UCA-induced immune suppression in mice. Here, we examined the involvement of 5-HT(2A) and PAF receptors in the ability of cis-UCA to stimulate immunomodulatory mediator production in primary human keratinocytes. Using real-time reverse transcription-PCR (RT-PCR), PAF but not 5-HT(2A) receptor mRNA was constitutively expressed in primary human keratinocytes. Treatment with cis-UCA increased prostaglandin E(2) (PGE(2)), tumor necrosis factor-alpha (TNF-alpha), and IL-6 secretion, whereas 5-HT only stimulated IL-6 production. Pretreatment with a 5-HT receptor antagonist partially inhibited IL-6 increase by 5-HT, but did not inhibit mediator production by cis-UCA. Similarly, a PAF receptor antagonist did not inhibit cis-UCA-induced increase in PGE(2). Intracellular calcium mobilization studies using a human epithelial cell line stably transfected with PAF receptor also showed little evidence that cis-UCA stimulated PAF receptor and it did not bind to this receptor. Thus, cis-UCA stimulates mediator production by a pathway that is independent of these receptors in human keratinocytes, and these cells may not be the major target for cis-UCA-induced immune suppression. PMID:19474802

Kaneko, Kazuyo; Travers, Jeffrey B; Matsui, Mary S; Young, Antony R; Norval, Mary; Walker, Susan L

2009-05-28

153

Pituitary Tumor Transforming Gene 1 Induces Tumor Necrosis Factor-? Production from Keratinocytes: Implication for Involvement in the Pathophysiology of Psoriasis.  

PubMed

Proliferation and differentiation in the epidermis must be tightly regulated. This regulation is known to involve a range of transcription factors, including pituitary tumor transforming gene 1 (PTTG1), a ubiquitously distributed transcription factor that regulates keratinocyte proliferation and differentiation. Psoriasis is a common but refractory skin disorder, the pathophysiology of which is characterized by hyperproliferation and impaired differentiation in the epidermis. The present study was conducted to clarify the less well-known roles of PTTG1 in the pathophysiology of psoriasis, focusing on its relationship with tumor necrosis factor-? (TNF-?), which is a critical mediator of the disease. The levels of PTTG1 expression were increased in the psoriatic epidermis. Overexpression of PTTG1 resulted in the overproduction of TNF-?, and TNF-? itself had an inductive effect on PTTG1 expression, suggesting that their expression may involve autoinduction. Moreover, overexpression of PTTG1 involved augmented the expression of cyclin A and B1 proteins in both cultured keratinocytes and the psoriatic epidermis. Therefore, enhanced expression of PTTG1 in the psoriatic epidermis may result in aberrant regulation of the cell cycle and impaired differentiation via the interplay between PTTG1 and TNF-?. PMID:23677169

Ishitsuka, Yosuke; Kawachi, Yasuhiro; Maruyama, Hiroshi; Taguchi, Shijima; Fujisawa, Yasuhiro; Furuta, Junichi; Nakamura, Yasuhiro; Ishii, Yoshiyuki; Otsuka, Fujio

2013-04-18

154

Oncogenes, Growth Factors, and Cancer.  

National Technical Information Service (NTIS)

In this taped lecture Dr. Aaronson reviews the biology of several types of oncogene and their interactions with related growth factors and growth factor receptors. He then plots their participation in the regulation of gene expression and in the prolifera...

1994-01-01

155

Murine Cutaneous Mastocytosis and Epidermal Melanocytosis Induced by Keratinocyte Expression of Transgenic Stem Cell Factor  

Microsoft Academic Search

Summary The growth and differentiation of mast cells and melanocytes require stem cell factor (SCF), the ligand for the kit receptor tyrosine kinase. SCF may exist as a membrane-bound or soluble molecule. Abnormalities of the SCF-kit signaling pathway, with increased local concentrations of soluble SCF, have been implicated in the pathogenesis of the human disease cutaneous mas- tocytosis, but have

Takahiro Kunisada; Shu-Zhuang Lu; Hisahiro Yoshida; Satomi Nishikawa; Shin-ichi Nishikawa; Masako Mizoguchi; Shin-ichi Hayashi; Lynda Tyrrell; David A. Williams; Xiaomei Wang; B. Jack Longley

2010-01-01

156

Induction of RANTES by TWEAK\\/Fn14 Interaction in Human Keratinocytes  

Microsoft Academic Search

TNF-like weak inducer of apoptosis (TWEAK), a member of the tumor necrosis factor (TNF) family, is a multifunctional cytokine that regulate cellular proliferation, angiogenesis, inflammation, and apoptosis. In this study, we investigated the effect of TWEAK on human keratinocytes. Primary cultured normal human keratinocytes constitutively expressed a TWEAK receptor, fibroblast growth factor-inducible 14 (Fn14), and produced regulated on activation, normal

Long Jin; Atsuhito Nakao; Masafumi Nakayama; Noriko Yamaguchi; Yuko Kojima; Nobuhiro Nakano; Ryoji Tsuboi; Ko Okumura; Hideo Yagita; Hideoki Ogawa

2004-01-01

157

Gene network dynamics controlling keratinocyte migration  

Microsoft Academic Search

Translation of large-scale data into a coherent model that allows one to simulate, predict and control cellular behavior is far from being resolved. Assuming that long-term cellular behavior is reflected in the gene expression kinetics, we infer a dynamic gene regulatory network from time-series measurements of DNA microarray data of hepatocyte growth factor-induced migration of primary human keratinocytes. Transferring the

Hauke Busch; David Camacho-Trullio; Zbigniew Rogon; Kai Breuhahn; Peter Angel; Roland Eils; Axel Szabowski

2008-01-01

158

Inhibition of NF-kappaB signaling interferes with phorbol ester-induced growth arrest of keratinocytes in a TNFR1-independent manner.  

PubMed

A skin-specific block in NF-kappaB signaling leads to hyperproliferation of the keratinocytes, inflammation, and spontaneous development of squamous cell carcinoma (SCC). Here we show that an inhibition of NF-kappaB signaling in keratinocytes, via the expression of the super-repressor/ degradation-resistant form of the IkappaBalpha protein (IkappaBalphaDN), interferes with the growth arrest induced by the tumor promoter 12-O-tetradecanoylphorbol 13-acetate (TPA). The IkappaBalphaDN cells are able to overcome the TPA-induced cell cycle block. Although SCC development as well as hyperproliferation due to IkappaBalphaDN expression in keratinocytes is known to require TNFR1 signaling, the effect of IkappaBalphaDN on phorbol ester signaling is downstream/independent of TNFR1. These data thus identify an interaction between IkappaBalphaDN and the tumor promoter TPA in the growth regulation of keratinocytes. The proposed mechanism is also likely to be significant in the process of cancer development due to NF-kappaB inhibition. PMID:19519169

Sur, Inderpreet; Ulvmar, Maria; Jungedal, Roger; Toftgård, Rune

2009-01-01

159

Plant polyphenols differentially modulate inflammatory responses of human keratinocytes by interfering with activation of transcription factors NF{kappa}B and AhR and EGFR-ERK pathway  

SciTech Connect

Molecular mechanisms underlying modulation of inflammatory responses in primary human keratinocytes by plant polyphenols (PPs), namely the glycosylated phenylpropanoid verbascoside, the stilbenoid resveratrol and its glycoside polydatin, and the flavonoid quercetin and its glycoside rutin were evaluated. As non-lethal stimuli, the prototypic ligand for epidermal growth factor receptor (EGFR) transforming growth factor alpha (TGFalpha), the combination of tumor necrosis factor (TNFalpha) and interferon (IFNgamma) (T/I), UVA + UVB irradiation, and bacterial lipopolysaccharide (LPS) were used. We demonstrated differential modulation of inflammatory responses in keratinocytes at signal transduction, gene transcription, and protein synthesis levels as a function of PP chemical structure, the pro-inflammatory trigger used, and PP interaction with intracellular detoxifying systems. The PPs remarkably inhibited constitutive, LPS- and T/I-induced but not TGFalpha-induced ERK phosphorylation. They also suppressed NFkappaB activation by LPS and T/I. Verbascoside and quercetin invariably impaired EGFR phosphorylation and UV-associated aryl hydrocarbon receptor (AhR)-mediated signaling, while rutin, polydatin and resveratrol did not affect EGFR phosphorylation and further activated AhR machinery in UV-exposed keratinocytes. In general, PPs down-regulated gene expression of pro-inflammatory cytokines/enzymes, except significant up-regulation of IL-8 observed under stimulation with TGFalpha. Both spontaneous and T/I-induced release of IL-8 and IP-10 was suppressed, although 50 {mu}M resveratrol and polydatin up-regulated IL-8. At this concentration, resveratrol activated both gene expression and de novo synthesis of IL-8 and AhR-mediated mechanisms were involved. We conclude that PPs differentially modulate the inflammatory response of human keratinocytes through distinct signal transduction pathways, including AhR and EGFR. - Graphical abstract: Display Omitted Highlights: > Effects of plant polyphenols on inflammatory responses in human keratinocytes. > Inflammatory stimuli used: TGFalpha, TNFalpha+IFNgamma, UVA+UVB, and LPS. > Inflammatory pathways connected with NFB, ERK1/2, EGFR, and AhR were investigated. > Plant polyphenols, flavonoids, stilbenoids, and phenylpropanoids, were studied. > Modulation of inflammation depends on phenolic core structure and glycosylation.

Potapovich, Alla I. [Tissue Engineering and Skin Pathophysiology Laboratory, Dermatology Research Institute (IDI IRCCS), Via Monti di Creta 104, Rome 00167 (Italy); Biology Department, Belarus State University, Skorina Prosp. 10, Minsk 220050 (Belarus); Lulli, Daniela; Fidanza, Paolo [Tissue Engineering and Skin Pathophysiology Laboratory, Dermatology Research Institute (IDI IRCCS), Via Monti di Creta 104, Rome 00167 (Italy); Kostyuk, Vladimir A. [Tissue Engineering and Skin Pathophysiology Laboratory, Dermatology Research Institute (IDI IRCCS), Via Monti di Creta 104, Rome 00167 (Italy); Biology Department, Belarus State University, Skorina Prosp. 10, Minsk 220050 (Belarus); De Luca, Chiara; Pastore, Saveria [Tissue Engineering and Skin Pathophysiology Laboratory, Dermatology Research Institute (IDI IRCCS), Via Monti di Creta 104, Rome 00167 (Italy); Korkina, Liudmila G., E-mail: l.korkina@idi.it [Tissue Engineering and Skin Pathophysiology Laboratory, Dermatology Research Institute (IDI IRCCS), Via Monti di Creta 104, Rome 00167 (Italy)

2011-09-01

160

Ligand activation of peroxisome proliferator-activated receptor-beta/delta(PPARbeta/delta) inhibits cell growth of human N/TERT-1 keratinocytes.  

PubMed

The functional role of peroxisome proliferator-activated receptor-beta(PPARbeta; also referred to as PPARdelta) in epidermal cell growth remains controversial. Recent evidence suggests that ligand activation of PPARbeta/delta increases cell growth and inhibits apoptosis in epidermal cells. In contrast, other reports suggest that ligand activation of PPARbeta/delta leads to the induction of terminal differentiation and inhibition of cell growth. In the present study, the effect of the highly specific PPARbeta/delta ligand GW0742 on cell growth was examined using a human keratinocyte cell line (N/TERT-1) and mouse primary keratinocytes. Ligand activation of PPARbeta/delta with GW0742 prevented cell cycle progression from G1 to S phase and attenuated cell proliferation in N/TERT-1 cells. Despite specifically activating PPARbeta/delta as revealed by target gene induction, no changes in PTEN, PDK and ILK expression or downstream phosphorylation of Akt were found in either N/TERT-1 cells or primary keratinocytes. Further, altered cell growth resulting from serum withdrawal and the induction of caspase-3 activity by ultraviolet radiation were unchanged in the absence of PPARbeta/delta expression and/or the presence of GW0742. While no changes in the expression of mRNAs encoding cell cycle control proteins were found in response to GW0742, a significant decrease in the level of ERK phosphorylation was observed. Results from these studies demonstrate that ligand activation of PPARbeta/delta does not lead to an anti-apoptotic effect in either human or mouse keratinocytes, but rather, leads to inhibition of cell growth likely through the induction of terminal differentiation. PMID:17254750

Burdick, Andrew D; Bility, Moses T; Girroir, Elizabeth E; Billin, Andrew N; Willson, Timothy M; Gonzalez, Frank J; Peters, Jeffrey M

2007-01-03

161

Asymmetric Migration of Human Keratinocytes under Mechanical Stretch and Cocultured Fibroblasts in a Wound Repair Model  

PubMed Central

Keratinocyte migration during re-epithelization is crucial in wound healing under biochemical and biomechanical microenvironment. However, little is known about the underlying mechanisms whereby mechanical tension and cocultured fibroblasts or keratinocytes modulate the migration of keratinocytes or fibroblasts. Here we applied a tensile device together with a modified transwell assay to determine the lateral and transmembrane migration dynamics of human HaCaT keratinocytes or HF fibroblasts. A novel pattern of asymmetric migration was observed for keratinocytes when they were cocultured with non-contact fibroblasts, i.e., the accumulative distance of HaCaT cells was significantly higher when moving away from HF cells or migrating from down to up cross the membrane than that when moving close to HF cells or when migrating from up to down, whereas HF migration was symmetric. This asymmetric migration was mainly regulated by EGF derived from fibroblasts, but not transforming growth factor ? or ?1 production. Mechanical stretch subjected to fibroblasts fostered keratinocyte asymmetric migration by increasing EGF secretion, while no role of mechanical stretch was found for EGF secretion by keratinocytes. These results provided a new insight into understanding the regulating mechanisms of two- or three-dimensional migration of keratinocytes or fibroblasts along or across dermis and epidermis under biomechanical microenvironment.

Lu, Dongyuan; Liu, Xiaofeng; Gao, Yuxin; Huo, Bo; Kang, Yingyong; Chen, Juan; Sun, Shujin; Chen, Li; Luo, Xiangdong; Long, Mian

2013-01-01

162

Human keratinocytes are a source for tumor necrosis factor alpha: Evidence for synthesis and release upon stimulation with endotoxin or ultraviolet light  

Microsoft Academic Search

Tumor necrosis factor alpha (TNF-alpha), in addition to being cytotoxic for certain tumor cells, has turned out as a multifunctional cytokine that is involved in the regulation of immunity and inflammation. Since human keratinocytes have been demonstrated to be a potent source of various cytokines, it was investigated whether epidermal cells synthesize and release TNF-alpha. Supernatants derived from normal human

A. S. Koeck; T. Schwarz; R. Kirnbauer; A. Urbanski; P. Perry; J. C. Ansel; T. A. Luger

1990-01-01

163

Upregulation of epidermal growth factor receptor 4 in oral leukoplakia  

PubMed Central

In the present study, we investigate the expression profile of the epidermal growth factor receptor family, which comprises EGFR/ErbB1, HER2/ErbB2, HER3/ErbB3 and HER4/ErbB4 in oral leukoplakia (LP). The expression of four epidermal growth factor receptor (EGFR) family genes and their ligands were measured in LP tissues from 14 patients and compared with levels in 10 patients with oral lichen planus (OLP) and normal oral mucosa (NOM) from 14 healthy donors by real-time polymerase chain reaction (PCR) and immunohistochemistry. Synchronous mRNA coexpression of ErbB1, ErbB2, ErbB3 and ErbB4 was detected in LP lesions. Out of the receptors, only ErbB4 mRNA and protein was more highly expressed in LP compared with NOM tissues. These were strongly expressed by epithelial keratinocytes in LP lesions, as shown by immunohistochemistry. Regarding the ligands, the mRNA of Neuregulin2 and 4 were more highly expressed in OLP compared with NOM tissues. Therefore, enhanced ErbB4 on the keratinocytes and synchronous modulation of EGFR family genes may contribute to the pathogenesis and carcinogenesis of LP.

Kobayashi, Hiroshi; Kumagai, Kenichi; Gotoh, Akito; Eguchi, Takanori; Yamada, Hiroyuki; Hamada, Yoshiki; Suzuki, Satsuki; Suzuki, Ryuji

2013-01-01

164

Upregulation of epidermal growth factor receptor 4 in oral leukoplakia.  

PubMed

In the present study, we investigate the expression profile of the epidermal growth factor receptor family, which comprises EGFR/ErbB1, HER2/ErbB2, HER3/ErbB3 and HER4/ErbB4 in oral leukoplakia (LP). The expression of four epidermal growth factor receptor (EGFR) family genes and their ligands were measured in LP tissues from 14 patients and compared with levels in 10 patients with oral lichen planus (OLP) and normal oral mucosa (NOM) from 14 healthy donors by real-time polymerase chain reaction (PCR) and immunohistochemistry. Synchronous mRNA coexpression of ErbB1, ErbB2, ErbB3 and ErbB4 was detected in LP lesions. Out of the receptors, only ErbB4 mRNA and protein was more highly expressed in LP compared with NOM tissues. These were strongly expressed by epithelial keratinocytes in LP lesions, as shown by immunohistochemistry. Regarding the ligands, the mRNA of Neuregulin2 and 4 were more highly expressed in OLP compared with NOM tissues. Therefore, enhanced ErbB4 on the keratinocytes and synchronous modulation of EGFR family genes may contribute to the pathogenesis and carcinogenesis of LP. PMID:23492901

Kobayashi, Hiroshi; Kumagai, Kenichi; Gotoh, Akito; Eguchi, Takanori; Yamada, Hiroyuki; Hamada, Yoshiki; Suzuki, Satsuki; Suzuki, Ryuji

2013-03-15

165

Wound Stimulation by Growth-Arrested Human Keratinocytes and Fibroblasts: HP802-247, a New-Generation Allogeneic Tissue Engineering Product  

Microsoft Academic Search

Background: HP802-247 is a new-generation, allogeneic tissue engineering product consisting of growth-arrested, human keratinocytes (K) and fibroblasts (F) delivered in a fibrin matrix by a spray device. Objective: To identify the preferred dose of HP802-247 based on cell concentration and K\\/F ratio. Methods: A multicenter, randomized, double-blind, placebo-controlled, explorative phase II study of 6 different doses of HP802-247 administered once

René Goedkoop; Rodney Juliet; Percy Hou Kang You; Judit Daroczy; Kees-Peter de Roos; Raf Lijnen; Eric Rolland; Thomas Hunziker

2010-01-01

166

Inhibition of tumor necrosis factor-alpha stimulated NFkappaB/p65 in human keratinocytes by alpha-melanocyte stimulating hormone and adrenocorticotropic hormone peptides.  

PubMed

Alpha-melanocyte stimulating hormone (alpha-MSH) has pigmentary, anti-inflammatory, antipyretic, and general immunomodulatory roles. It can oppose several cytokines including tumor necrosis factor-alpha in a number of tissues, including skin. We have previously shown that alpha-MSH can inhibit tumor necrosis factor-alpha stimulated intercellular adhesion molecule 1 upregulation and nuclear factor kappaB (NFkappaB) transcription factor activation in melanocyte and melanoma cells. It is thought, however, that this MSH biology may also extend to other cells of the skin and in this study we extend our work to keratinocytes. We have investigated in detail the ability of three alpha-MSH peptides to inhibit tumor necrosis factor alpha stimulated NFkappaB activation in nonpigmentary HaCaT keratinocytes (alpha-MSH, L-Lys-L-Pro-L-Val, and L-Lys-L-Pro-D-Val) and two adrenocorticotropic hormone (ACTH) peptides (1-17 and 1-39), reported to be present in skin tissue. NFkappaB/p65 activation was analyzed by electrophoretic mobility shift assay and immunofluorescent microscopy. alpha-MSH, L-Lys-L-Pro-L-Val, and L-Lys-L-Pro-D-Val all significantly inhibited tumor necrosis factor alpha stimulated NFkappaB activation, whereas ACTH 1-17 and 1-39 did not, in the HaCaT keratinocytes. MSH peptides and ACTH 1-39 were effective, however, at inhibiting NFkappaB activation in normal human keratinocytes. Immunolabeling of inhibitor kappaBalpha of NFkappaB (IkappaBalpha) revealed an abnormal localization to the nucleus of HaCaT cells, which was unaffected by MSH/ACTH peptides. In contrast, normal human keratinocytes showed a normal IkappaBalpha distribution that responded to MSH/ACTH with nuclear translocation. Our data support previous work on the role of MSH/ACTH peptides as immunomodulatory/anti-inflammatory regulators, and extend this work to keratinocytes identifying a novel IkappaBalpha mechanism and extends findings to ACTH peptides, identifying an abnormal IkappaBalpha mechanism in the immortal HaCaT versus normal keratinocyte. PMID:12485424

Moustafa, Manar; Szabo, Marika; Ghanem, Ghanem E; Morandini, Renato; Kemp, E Helen; MacNeil, Sheila; Haycock, John W

2002-12-01

167

Human Keratinocytes That Express hTERT and Also Bypass a p16INK4a-Enforced Mechanism That Limits Life Span Become Immortal yet Retain Normal Growth and Differentiation Characteristics  

PubMed Central

Normal human cells exhibit a limited replicative life span in culture, eventually arresting growth by a process termed senescence. Progressive telomere shortening appears to trigger senescence in normal human fibroblasts and retinal pigment epithelial cells, as ectopic expression of the telomerase catalytic subunit, hTERT, immortalizes these cell types directly. Telomerase expression alone is insufficient to enable certain other cell types to evade senescence, however. Such cells, including keratinocytes and mammary epithelial cells, appear to require loss of the pRB/p16INK4a cell cycle control mechanism in addition to hTERT expression to achieve immortality. To investigate the relationships among telomerase activity, cell cycle control, senescence, and differentiation, we expressed hTERT in two epithelial cell types, keratinocytes and mesothelial cells, and determined the effect on proliferation potential and on the function of cell-type-specific growth control and differentiation systems. Ectopic hTERT expression immortalized normal mesothelial cells and a premalignant, p16INK4a-negative keratinocyte line. In contrast, when four keratinocyte strains cultured from normal tissue were transduced to express hTERT, they were incompletely rescued from senescence. After reaching the population doubling limit of their parent cell strains, hTERT+ keratinocytes entered a slow growth phase of indefinite length, from which rare, rapidly dividing immortal cells emerged. These immortal cell lines frequently had sustained deletions of the CDK2NA/INK4A locus or otherwise were deficient in p16INK4a expression. They nevertheless typically retained other keratinocyte growth controls and differentiated normally in culture and in xenografts. Thus, keratinocyte replicative potential is limited by a p16INK4a-dependent mechanism, the activation of which can occur independent of telomere length. Abrogation of this mechanism together with telomerase expression immortalizes keratinocytes without affecting other major growth control or differentiation systems.

Dickson, Mark A.; Hahn, William C.; Ino, Yasushi; Ronfard, Vincent; Wu, Jenny Y.; Weinberg, Robert A.; Louis, David N.; Li, Frederick P.; Rheinwald, James G.

2000-01-01

168

Caveolin-1 and -2 Expression Is Differentially Regulated in Cultured Keratinocytes and within the Regenerating Epidermis of Cutaneous Wounds  

Microsoft Academic Search

Keratinocyte growth factor (KGF) and its receptor are involved in various types of epithelial repair processes. To gain insight into the molecular mechanisms of KGF action in the healing skin wound, we searched for genes which are regulated by this factor in cultured keratinocytes. Using the PCR-select technology we constructed a subtractive cDNA library. One of the KGF-regulated genes that

Marcus G. Gassmann; Sabine Werner

2000-01-01

169

Primary structure of keratinocyte transglutaminase  

Microsoft Academic Search

The nucleotide and deduced amino acid sequences of the coding regions of human and rat keratinocyte transglutaminases (protein-glutamine: amine γ-glutamyltransferase; EC 2.3.2.13) have been determined. These yield proteins of â¼90 kDa that are 92% identical, indicative of the conservation of important structural features. Alignments of amino acid sequences show substantial similarity among the keratinocyte transglutaminase, human clotting factor XIII catalytic

M. A. Phillips; B. E. Stewart; Q. Qin; R. H. Rice; R. Chakravarty; E. E. Floyd; A. M. Jetten

1990-01-01

170

An unbiased in vivo screen reveals multiple transcription factors that control HPV E6-regulated hTERT in keratinocytes.  

PubMed

Activation of telomerase by human papillomavirus 16 (HPV16) E6 is a critical step for cell immortalization and transformation in human foreskin keratinocytes (HFKs). Multiple transcription factors have been identified as being involved in E6-induced hTERT expression. Here, we adapted an unbiased in vivo screen using a LacO-LacI system in human cells to discover hTERT promoter-interacting regulators. This approach allowed us to identify a novel hTERT repressor, Maz, which bound the hTERT promoter. E6 expression reduced Maz binding and correspondingly increased Sp1 binding at the hTERT promoter. Knockdown of Maz further increased histone acetylation, as well as hTERT expression in the presence of E6. Overall, these data indicate the utility of a novel screen for promoter-interacting and transcription-regulating proteins. These data also highlight multiple factors that normally regulate hTERT repression in HFKs, and therefore are targeted by E6 for hTERT expression. PMID:24074563

Xu, Mei; Katzenellenbogen, Rachel A; Grandori, Carla; Galloway, Denise A

2013-08-08

171

Staphylococcus aureus peptidoglycan stimulates granulocyte macrophage colony-stimulating factor production from human epidermal keratinocytes via mitogen-activated protein kinases  

Microsoft Academic Search

Epidermal keratinocytes with atopic dermatitis (AD) overproduce mediators such as granulocyte macrophage colony-stimulating factor (GM-CSF), which are associated with pathology of AD. We found that peptidoglycan (PGN) of Staphylococcus aureus, which is frequently observed in lesion with AD, induced the production of numerous mediators such as GM-CSF and regulated on activation, normal T-cell expressed and secreted. Moreover, PGN phosphorylated extracellular-signal-regulated

Masahiro Matsubara; Daisuke Harada; Haruhiko Manabe; Kazuhide Hasegawa

2004-01-01

172

Staphylococcus aureus peptidoglycan stimulates granulocyte macrophage colony-stimulating factor production from human epidermal keratinocytes via mitogen-activated protein kinases  

Microsoft Academic Search

Epidermal keratinocytes with atopic dermatitis (AD) overproduce mediators such as granulocyte macrophage colony- stimulating factor (GM-CSF), which are associated with pathology of AD. We found that peptidoglycan (PGN) of Staphylococcus aureus, which is frequently observed in lesion with AD, induced the production of numerous mediators such as GM-CSF and regulated on activation, normal T-cell expressed and secreted. Moreover, PGN phosphorylated

Masahiro Matsubara; Daisuke Harada; Haruhiko Manabe; Kazuhide Hasegawa

2004-01-01

173

Identification of a novel keratinocyte mitogen derived from bovine pituitary glands.  

PubMed

Bovine pituitary glands contain one or more factors that are important for keratinocyte proliferation in serum-free culture medium. We used a tissue culture system in which the growth of keratinocytes in basal medium (KBM) containing insulin was dependent upon exogenous growth factors. Using this experimental system, we began to purify and characterize the pituitary factor(s) necessary for clonal growth of human keratinocytes in serum-free medium. Proteins of approximately 150 kDa and 95 kDa bound specifically to living keratinocytes, and we suggest that the 95 kDa protein is a likely novel mitogen. Although prolactin has been previously identified as a pituitary hormone that may act as an in vitro mitogen for keratinocytes, imunoblots indicated that the 95 kDa protein was unrelated to prolactin. Furthermore, the 95 kDa protein showed high homology with a bovine 90 kDa heat shock protein in the limited sequencing of an internal peptide. PMID:9209675

González-Castro, U; Castells-Rodellas, A; Krueger, J G

1997-05-01

174

Growth factors in synaptic function  

PubMed Central

Synapses are increasingly recognized as key structures that malfunction in disorders like schizophrenia, mental retardation, and neurodegenerative diseases. The importance and complexity of the synapse has fuelled research into the molecular mechanisms underlying synaptogenesis, synaptic transmission, and plasticity. In this regard, neurotrophic factors such as netrin, Wnt, transforming growth factor-? (TGF-?), tumor necrosis factor-? (TNF-?), and others have gained prominence for their ability to regulate synaptic function. Several of these factors were first implicated in neuroprotection, neuronal growth, and axon guidance. However, their roles in synaptic development and function have become increasingly clear, and the downstream signaling pathways employed by these factors have begun to be elucidated. In this review, we will address the role of these factors and their downstream effectors in synaptic function in vivo and in cultured neurons.

Poon, Vivian Y.; Choi, Sojoong; Park, Mikyoung

2013-01-01

175

Keratinocyte stimulation of matrix metalloproteinase-1 production and proliferation in fibroblasts: regulation through mitogen-activated protein kinase signalling events  

Microsoft Academic Search

Incubation of human dermal fibroblasts in keratinocyte-conditioned culture medium led to a 5.7-fold increase in the level of matrix metalloproteinase-1. Virtually all of the matrix metalloproteinase-1 – inducing activity could be related to agonists acting through members of the epidermal growth factor receptor family or to agonists acting through the interleukin-1 receptor. The same keratinocyte-conditioned medium also induced a modest

S E Moon; N Bhagavathula; J Varani

2002-01-01

176

A Murine Monoclonal Antibody (VM1) Against Human Basal Cells Inhibits the Growth of Human Keratinocytes in Culture  

Microsoft Academic Search

Using epidermal cells from psoriatic plaques as the immunogen, an IgG1 murine monoclonal antibody, VM-1, has been produced which stains basal keratinocytes on frozen sections of skin obtained from normal individuals and from psoriatic plaques. In some areas of both normal and psoriatic epidermis, the cell layer immediately above the basal cells is also stained. Cells in the external root

Allan R. Oseroff; Eva A. Pfendt; Linda DiCicco; Vera B. Morhenn

1985-01-01

177

Dehydroxymethylepoxyquinomicin, a novel nuclear factor-kappaB inhibitor, prevents inflammatory injury induced by interferon-gamma and histamine in NCTC 2544 keratinocytes.  

PubMed

1. The novel nuclear factor (NF)-kappaB inhibitor dehydroxymethylepoxyquinomicin (DHMEQ) is a derivative of the antibiotic epoxyquinomicin C from Amycolatopsis sp. that has been found to inhibit tumour necrosis factor (TNF)-alpha-induced activation of NF-kappaB by suppressing nuclear translocation of NF-kappaB. The aim of the present study was to determine the effects of DHMEQ on interferon (IFN)-gamma- and histamine-activated NCTC 2544 keratinocytes. 2. Keratinocytes were stimulated or not with 200 U/mL IFN-gamma and 10(-4) mol/L histamine in the absence or presence of different concentrations of DHMEQ (1, 5 and 10 microg/mL) or hydrocortisone (10(-5) mol/L), which was used as a reference anti-inflammatory drug. After 48 h, each sample was tested for the presence of intercellular adhesion molecule (ICAM)-1 by western blot analysis, as well as for the release of monocyte chemoattractant protein (MCP)-1, RANTES and interleukin (IL)-8 using specific sandwich ELISAs. To verify the effect of DHMEQ on cell viability of non-stimulated NCTC 2544 keratinocytes, the 3-(4,5-dimethyl-2 thiazoyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay was used. 3. The results showed that 10 microg/mL DHMEQ potently inhibited ICAM-1 production (by 50%), as well as the release of MCP-1 (to 25% of control), RANTES (to 5% of control) and IL-8 (to 2% of control). The results of the MTT assay indicated that DHMEQ has no effect on cell viability. 4. In conclusion, DHMEQ inhibits the IFN-gamma- and histamine-induced activation of the keratinocyte cell line NCTC 2544. The anti-inflammatory effects of DHMEQ could be exploited by applying the drug topically alone or in combination with sub-toxic concentrations of anti-inflammatory drugs to producer a synergistic effect. PMID:20337659

Cardile, Venera; Libra, Massimo; Caggia, Silvia; Frasca, Giuseppina; Umezawa, Kazuo; Stivala, Franca; Mazzarino, Maria Clorinda; Bevelacqua, Ylenia; Coco, Marinella; Malaponte, Grazia

2010-03-12

178

Overexpression of CRABPI in suprabasal keratinocytes enhances the proliferation of epidermal basal keratinocytes in mouse skin topically treated with all-trans retinoic acid  

SciTech Connect

We investigated whether ectopic expression of CRABPI, a cellular retinoic acid binding protein, influenced the actions of all-trans retinoic acid (ATRA) in transgenic (TG) mice. We targeted CRABPI to the basal vs. suprabasal layers of mouse epidermis by using the keratin 14 (K14) and keratin 10 (K10) promoters, respectively. Greater CRABPI protein levels were detected in the epidermis of adult transgenic(+) mice than in transgenic(-) mice for both transgenes. In adult mouse skin CRABPI overexpression in the basal or suprabasal keratinocytes did not cause morphological abnormalities, but did result in decreased CRABPII mRNA levels. Ectopically overexpressed CRABPI in suprabasal keratinocytes, but not in basal keratinocytes, enhanced the thickening of the epidermis induced by topical ATRA treatments (10 {mu}M, 400 {mu}l for 4 days) by 1.59 {+-} 0.2-fold (p < 0.05). ATRA treatment (10 {mu}M) resulted in a 59.9 {+-} 9.8% increase (p < 0.05) in the BrdU labeling index in K10/FLAG-CRABPI TG(+) mice vs. TG(-) mice. Retinoid topical treatments reduced p27 and CYP26A1 mRNA levels in TG(+) and TG(-) mouse skin in K14 and K10/FLAG-CRABPI transgenic mice. As epidermal basal keratinocyte proliferation is stimulated by paracrine growth factors secreted by ATRA activated suprabasal keratinocytes, our results indicate that CRABPI overexpression in suprabasal keratinocytes enhances the physiological functions of ATRA.

Tang, X.-H.; Vivero, Marina [Department of Pharmacology, Weill Cornell Medical College, 1300 York Avenue, New York, NY 10021 (United States); Gudas, Lorraine J. [Department of Pharmacology, Weill Cornell Medical College, 1300 York Avenue, New York, NY 10021 (United States)], E-mail: ljgudas@med.cornell.edu

2008-01-01

179

The Insulin-like Growth Factor 1 Receptor Is Expressed by Epithelial Cells with Proliferative Potential in Human Epidermis and Skin Appendages: Correlation of Increased Expression with Epidermal Hyperplasia  

Microsoft Academic Search

Ligand-mediated activation of the insulin-like growth factor 1 (IGF-1) receptor is critical for epidermal keratinocyte proliferation in vitro, and its expression in normal and psoriatic epidermis suggests that it might regulate keratinocyte proliferation in vivo. In this study, we used a monoclonal antibody (?-IR3) that binds to the ?-chain of this receptor to study its expression (1) in other epithelial

Emmilia Hodak; Alice B. Gottlieb; Michele Anzilotti; James G. Krueger

1996-01-01

180

Sumoylation Dynamics During Keratinocyte Differentiation  

PubMed Central

Summary SUMO modification regulates the activity of numerous transcription factors that have a direct role in cell cycle progression, apoptosis, cellular proliferation, and development, but its role in differentiation processes is less clear. Keratinocyte differentiation requires the coordinated activation of a series of transcription factors, and as several critical keratinocyte transcription factors are known to be SUMO substrates, we investigated the role of sumoylation in keratinocyte differentiation. In a human keratinocyte cell line model (HaCaT cells), calcium-induced differentiation led to the transient and coordinated transcriptional activation of the genes encoding critical sumoylation system components, including SAE1, SAE2, Ubc9, SENP1, Miz-1 (PIASx?), SUMO2, and SUMO3. The increased gene expression resulted in higher levels of the respective proteins and changes in the pattern of sumoylated substrate proteins during the differentiation process. Similar to the HaCaT results, stratified human foreskin keratinocytes showed an upregulation of Ubc9 in the suprabasal layers. Lastly, abrogation of sumoylation by Gam1 expression severely disrupted normal HaCaT differentiation, consistent with an important role for sumoylation in the proper progression of this biological process.

Deyrieux, Adeline F.; Rosas-Acosta, German; Ozbun, Michelle A.; Wilson, Van G.

2012-01-01

181

Neuroprotection by drug-induced growth factors  

Microsoft Academic Search

Growth factors are a heterogeneous group of polypeptides that act through specific receptors to regulate cell growth, proliferation, development, differentiation and regeneration. Nerve growth factor (NGF) and transforming growth factor-beta1 (TGF-?1) are members of this group. The increasing evidence points out the important role of these two factors in developmental nervous system as well as in the pathogenesis processes of

Yuan Zhu; Josef Krieglstein

2003-01-01

182

Essential role of integrin-linked kinase in regulation of phagocytosis in keratinocytes.  

PubMed

Phagocytic melanosome uptake by epidermal keratinocytes is a central protective mechanism against damage induced by ultraviolet radiation. Phagocytosis requires formation of pseudopodia via actin cytoskeleton rearrangements. Integrin-linked kinase (ILK) is an important modulator of actin cytoskeletal dynamics. We have examined the role of ILK in regulation of phagocytosis, using epidermal keratinocytes isolated from mice with epidermis-restricted Ilk gene inactivation. ILK-deficient cells exhibited severely impaired capacity to engulf fluorescent microspheres in response to stimulation of the keratinocyte growth factor (KGF) receptor or the protease-activated receptor-2. KGF induced ERK phosphorylation in ILK-expressing and ILK-deficient cells, suggesting that ILK is not essential for KGF receptor signaling. In contrast, KGF promoted activation of Rac1 and formation of pseudopodia in ILK-expressing, but not in ILK-deficient cells. Rac1-deficient keratinocytes also showed substantially impaired phagocytic ability, underlining the importance of ILK-dependent Rac1 function for particle engulfment. Finally, cross-modulation of KGF receptors by integrins may be another important element, as integrin ?1-deficient keratinocytes also fail to show significant phagocytosis in response to KGF. Thus, we have identified a novel signaling pathway essential for phagocytosis in keratinocytes, which involves ILK-dependent activation of Rac1 in response to KGF, resulting in the formation of pseudopodia and particle uptake. PMID:22767228

Sayedyahossein, Samar; Nini, Lylia; Irvine, Timothy S; Dagnino, Lina

2012-07-05

183

Growth factors in orthopedic surgery.  

PubMed

Growth factors have represented an essential issue of interest for the researchers and clinicians in orthopedics and trauma over the last 40 years. In the last 10 to 15 years, the advances registered in this field have permitted the identification of the most active cellular and humoral factors as well as the improvement of their use in the orthopedic and trauma surgery. Their domain of application has been continuously enlarged and the results have been visible from the beginning. The authors present their appreciation on the actual state of this subject as well as their experience with results and related conclusions. PMID:20302195

Zaharia, Comeliu; Niculescu, Marius; Despa, Nicoleta; Simionescu, Maya; Jinga, Victor; Fleseriu, Irina

184

The Epidermal Growth Factor Receptor Increases Cytokine Production and Cutaneous Inflammation in Response to Ultraviolet Irradiation  

PubMed Central

The epidermal growth factor receptor (EGFR) is activated in cutaneous keratinocytes upon ultraviolet (UV) exposure and has been implicated in ultraviolet-(UV-)induced inflammation and skin tumorigenesis. Egfr mutant mice and EGFR inhibitors were used to investigate the hypothesis that EGFR activation augments inflammation following UV irradiation. Topical treatment of mouse skin with the EGFR inhibitor AG1478 before UV exposure suppressed UV-induced erythema, edema, mast cell infiltration, and neutrophil infiltration. Genetic ablation of Egfr and EGFR inhibition by AG1478 also suppressed the increase in the proinflammatory cytokines tumor necrosis factor ? (TNF-?), interleukin-1?, KC (murine IL-8), and cyclooxygenase-2 (COX-2) after UV exposure of cultured keratinocytes. Finally, genetic ablation of inhibition of EGFR in cultured keratinocytes decreased p38 activation after UV, while inhibition of p38 kinase reduced COX-2 expression after UV. These data demonstrate that EGFR regulates multiple aspects of UV-induced inflammation and suggest activation of p38 kinase leading to increased COX-2 and cytokine expression as one mechanism through which it acts.

El-Abaseri, Taghrid Bahig; Repertinger, Susan K.; Hansen, Laura A.

2013-01-01

185

The epidermal growth factor receptor increases cytokine production and cutaneous inflammation in response to ultraviolet irradiation.  

PubMed

The epidermal growth factor receptor (EGFR) is activated in cutaneous keratinocytes upon ultraviolet (UV) exposure and has been implicated in ultraviolet-(UV-)induced inflammation and skin tumorigenesis. Egfr mutant mice and EGFR inhibitors were used to investigate the hypothesis that EGFR activation augments inflammation following UV irradiation. Topical treatment of mouse skin with the EGFR inhibitor AG1478 before UV exposure suppressed UV-induced erythema, edema, mast cell infiltration, and neutrophil infiltration. Genetic ablation of Egfr and EGFR inhibition by AG1478 also suppressed the increase in the proinflammatory cytokines tumor necrosis factor ? (TNF- ? ), interleukin-1 ? , KC (murine IL-8), and cyclooxygenase-2 (COX-2) after UV exposure of cultured keratinocytes. Finally, genetic ablation of inhibition of EGFR in cultured keratinocytes decreased p38 activation after UV, while inhibition of p38 kinase reduced COX-2 expression after UV. These data demonstrate that EGFR regulates multiple aspects of UV-induced inflammation and suggest activation of p38 kinase leading to increased COX-2 and cytokine expression as one mechanism through which it acts. PMID:23878744

El-Abaseri, Taghrid Bahig; Hammiller, Brianna; Repertinger, Susan K; Hansen, Laura A

2013-06-25

186

Fibroblast growth factor receptor inhibitors.  

PubMed

Fibroblast growth factor receptors (FGFRs) play an important role in embryonic development, angiogenesis, wound healing, cell proliferation and differentiation. The fibroblast growth factor receptor (FGFR) isoforms have been under intense scrutiny for effective anticancer drug candidates. The fibroblast growth factor (FGF) and its receptor (FGFR) provide another pathway that seems critical to monitoring angiogenesis. Recent findings suggest that FGFR mediates signaling, regulates the PKM2 activity, and plays a crucial role in cancer metabolism. The current review also covers the recent findings on the role of FGFR1 in cancer metabolism. This paper reviews the progress, mechanism, and binding modes of recently known kinase inhibitors such as PD173074, SU series and other inhibitors still under clinical development. Some of the structural classes that will be highlighted in this review include Pyrido[2,3-d]pyrimidines, Indolin- 2-one, Pyrrolo[2,1-f][1,2,4]triazine, Pyrido[2,3-d]pyrimidin-7(8H)-one, and 1,6- Naphthyridin-2(1H)-ones. PMID:23016864

Kumar, Suneel B V S; Narasu, Lakshmi; Gundla, Rambabu; Dayam, Raveendra; J A R P, Sarma

2013-01-01

187

Factors Affecting Growth Factor Activity in Goat Milk  

Microsoft Academic Search

Growth factors that are present in goat milk may be responsible for its beneficial effects on the digestive system as described in ancient Chinese medical texts. To develop a nutraceutical product rich in growth fac- tors for promoting gastrointestinal health, it is essen- tial to collect milk with consistently high growth factor activity.Therefore,weinvestigatedthefactorsaffecting growth factor activity in goat milk. Among

F. Y. Wu; P. H. Tsao; D. C. Wang; S. Lin; J. S. Wu; Y. K. Cheng

2006-01-01

188

Growth factors in haematological cancers.  

PubMed

Since their discovery just under a century ago, growth factors (GFs) have been used almost ubiquitously in haematology. Many haematological cancers are associated with bone marrow failure, either as a direct consequence of the disease or its treatment. Colony stimulating factors (CSFs) have been used to address the problems associated with the resulting cytopenias, however, concerns about the potential leukaemogenic effects of some of these CSFs led to a degree of initial hesitancy in usage, particularly in the management of acute myeloid leukaemia (AML). This has now been largely overcome. Other limitations have included cost and side effect profiles (the latter particularly with the multilineage factors). There has been wide variation locally, nationally and internationally in the usage of GFs. The American Society of Clinical Oncologists (ASCO) attempted to rationalise the usage of GFs by producing a consensus document enumerating the evidence-based indications for use of GFs. There is little information on cost effectiveness, this remains an important issue for the future. Peripheral blood stem cell transplantation (PBSCT) has revolutionised the management of many malignant conditions and has contributed to the increased use of growth factors. Many other indications are emerging for GFs used singly or in combination. Current clinical applications of GFs include: i) amelioration of cytopenias following chemotherapy and stem cell transplantation, ii) chemotherapy dose maintenance and escalation, iii) chemosensitisation and modification of disease states, iv) optimisation of methods for mobilisation of progenitor stem cells, v) immunotherapy, and vi) as therapeutic targets for treatment of haematolgical malignancies. PMID:15989543

Osuji, Nnenna; Pettengell, R

2002-05-01

189

Physiological factors influencing capillary growth.  

PubMed

(1) Angiogenesis (growth of new capillaries from an existing capillary bed) may result from a mismatch in microvascular supply and metabolic demand (metabolic error signal). Krogh examined the distribution and number of capillaries to explore the correlation between O(2) delivery and O(2) consumption. Subsequently, the heterogeneity in angiogenic response within a muscle has been shown to reflect either differences in fibre type composition or mechanical load. However, local control leads to targetted angiogenesis in the vicinity of glycolytic fibre types following muscle stimulation, or oxidative fibres following endurance training, while heterogeneity of capillary spacing is maintained during ontogenetic growth. (2) Despite limited microscopy resolution and lack of specific markers, Krogh's interest in the structure of the capillary wall paved the way for understanding the mechanisms of capillary growth. Angiogenesis may be influenced by the response of perivascular or stromal cells (fibroblasts, macrophages and pericytes) to altered activity, likely acting as a source for chemical signals modulating capillary growth such as vascular endothelial growth factor. In addition, haemodynamic factors such as shear stress and muscle stretch play a significant role in adaptive remodelling of the microcirculation. (3) Most indices of capillarity are highly dependent on fibre size, resulting in possible bias because of scaling. To examine the consequences of capillary distribution, it is therefore helpful to quantify the area of tissue supplied by individual capillaries. This allows the spatial limitations inherent in most models of tissue oxygenation to be overcome generating an alternative approach to Krogh's tissue cylinder, the capillary domain, to improve descriptions of intracellular oxygen diffusion. PMID:20946238

Egginton, S

2011-07-01

190

Improvement of hind-limb paralysis following traumatic spinal cord injury in rats by grafting normal human keratinocytes: new cell-therapy strategy for nerve regeneration.  

PubMed

Somatic (adult) stem cells are thought to have pluripotency, just as do embryotic stem (ES) cells. We investigated the possibility that grafted epithelial keratinocytes could induce spinal cord regeneration in an animal model of spinal cord injury (SCI). Normal human keratinocytes were cultured by the routine technique, and normal human dermal fibroblasts were cultured by a similar method as a control group. SCI model was prepared by dropping a 10-g weight onto the exposed spinal cord of rats from a height of 25 mm, and 8 days later, the cultured cells were grafted into the injury site. Motor function was significantly improved in the cultured-keratinocyte-grafted group compared with that in the fibroblast-grafted group. After functional observation, human nestin- and nuclei-positive cells were found at the grafted spinal cord. Grafted cultured keratinocytes induced in vitro morphological changes in the neural induction medium. These results indicated one possibility that some of the grafted cultured keratinocytes survived and could have contributed to neural regeneration. On the other hand, it should be noted that the grafted cultured keratinocytes secreted a large amount of enzymes and/or growth factors. Therefore, another possibility is that the grafted-keratinocyte-derived factors could induce survived cell growth and endogenous neural differentiation of spinal-nerve-derived stem cells surrounding the injured spinal cord, leading to functional recovery. Epithelial stem cell therapy may be applied clinically in the near future to treat SCI. PMID:21842261

Inoue, Hajime; Takenaga, Mitsuko; Ohta, Yuki; Tomioka, Miyuki; Watabe, Yu-Ichi; Aihara, Masaki; Kumagai, Norio

2011-08-13

191

Production of growth factors related to fibroblast growth factor and platelet-derived growth factor by human embryonal carcinoma cells  

Microsoft Academic Search

Summary  Previous studies have demonstrated that mouse embryonal carcinoma (EC) cells produce at least two growth factors: one related\\u000a to platelet-derived growth factor (PDGF) and another related to basic fibroblast growth factor (FGFb). Since human EC cell\\u000a lines are being used with increased frequency, the current study examined whether human EC cells produce growth factors, in\\u000a particular those produced by mouse

Jay Tiesman; Anita Meyer; Ronald N. Hines; Angie Rizzino

1988-01-01

192

Keratinocytes from APP/APLP2-deficient mice are impaired in proliferation, adhesion and migration in vitro  

SciTech Connect

Growing evidence shows that the soluble N-terminal form (sAPP{alpha}) of the amyloid precursor protein (APP) represents an epidermal growth factor fostering keratinocyte proliferation, migration and adhesion. APP is a member of a protein family including the two mammalian amyloid precursor-like proteins APLP1 and APLP2. In the mammalian epidermis, only APP and APLP2 are expressed. APP and APLP2-deficient mice die shortly after birth but do not display a specific epidermal phenotype. In this report, we investigated the epidermis of APP and/or APLP2 knockout mice. Basal keratinocytes showed reduced proliferation in vivo by about 40%. Likewise, isolated keratinocytes exhibited reduced proliferation rates in vitro, which could be completely rescued by either exogenously added recombinant sAPP{alpha}, or by co-culture with dermal fibroblasts derived from APP knockout mice. Moreover, APP-knockout keratinocytes revealed reduced migration velocity resulting from severely compromised cell substrate adhesion. Keratinocytes from double knockout mice died within the first week of culture, indicating essential functions of APP-family members for survival in vitro. Our data indicate that sAPP{alpha} has to be considered as an essential epidermal growth factor which, however, in vivo can be functionally compensated to a certain extent by other growth factors, e.g., factors released from dermal fibroblasts.

Siemes, Christina [Institute of Cell Biology and Bonner Forum Biomedizin, University of Bonn, Ulrich-Haberlandstr. 61A, 53121 Bonn (Germany); Quast, Thomas [Institute of Cell Biology and Bonner Forum Biomedizin, University of Bonn, Ulrich-Haberlandstr. 61A, 53121 Bonn (Germany); Kummer, Christiane [Institute of Cell Biology and Bonner Forum Biomedizin, University of Bonn, Ulrich-Haberlandstr. 61A, 53121 Bonn (Germany); Wehner, Sven [Institute of Cell Biology and Bonner Forum Biomedizin, University of Bonn, Ulrich-Haberlandstr. 61A, 53121 Bonn (Germany); Kirfel, Gregor [Institute of Cell Biology and Bonner Forum Biomedizin, University of Bonn, Ulrich-Haberlandstr. 61A, 53121 Bonn (Germany); Mueller, Ulrike [Max Planck Institute for Brain Research, Deutschordenstr. 46, 60528 Frankfurt (Germany) and Institute for Pharmacy and Molecular Biotechnology, University of Heidelberg, Im Neuenheimer Feld 364, 69120 Heidelberg (Germany); Herzog, Volker [Institute of Cell Biology and Bonner Forum Biomedizin, University of Bonn, Ulrich-Haberlandstr. 61A, 53121 Bonn (Germany)]. E-mail: Herzog@uni-bonn.de

2006-07-01

193

Dermal fibroblasts tumor suppression of ras-transformed keratinocytes is associated with induction of squamous cell differentiation.  

PubMed Central

We have previously reported that tumor formation of ras-transformed keratinocytes can be suppressed by dermal fibroblasts through production of a diffusible growth inhibitory factor of the transforming growth factor-beta (TGF-beta) family. Keratinocytes transformed by ras and E1a oncogenes or papilloma-derived keratinocytes transformed by a ras oncogene show concomitant resistance to dermal fibroblast tumor suppression and TGF-beta growth inhibition. We report here that dermal fibroblast tumor suppression is associated with a striking induction of squamous cell differentiation and that this effect is blocked in tumors resistant to dermal fibroblast inhibition. This experimental system strongly supports the notion that suppression of tumorigenicity and induction of a differentiated phenotype are closely associated events. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7

Ramon y Cajal, S.; Missero, C.; Marchetti, E.; Dotto, G. P.

1994-01-01

194

Species-specific detection of growth factor gene expression in developing murine prostatic tissue.  

PubMed

The aim of the present study was to develop a method by which the expression of paracrine signaling molecules could be localized to either epithelial or stromal cells of developing prostatic tissue. Heterospecific tissue recombinants composed of mouse urogenital epithelium (mouse UGE) plus rat urogenital mesenchyme (rat UGM) and the reciprocal tissue recombinants, rat urogenital epithelium (rat UGE) plus mouse urogenital mesenchyme (mouse UGM), were grafted under the renal capsule in intact, athymic male mouse and rat hosts. After 2 wk of growth, RNA from the grafts was analyzed by species-specific reverse transcription-polymerase chain reaction for the expression of the mRNA for the following molecules: transforming growth factors beta1, beta3, and alpha; epidermal growth factor; epidermal growth factor receptor; and keratinocyte growth factor. The species of expression of these growth factor and receptor gene products within the heterospecific tissue recombinants was identified, allowing determination of the cell layer in which the genes were expressed. Identification of the tissue-specific expression of the growth factor and growth factor receptor profiles of the epithelium and mesenchyme of this in vivo model provides a basis for understanding the autocrine and paracrine mediators of cell-cell interactions in prostatic development. PMID:9674998

Haughney, P C; Hayward, S W; Dahiya, R; Cunha, G R

1998-07-01

195

Secreted Growth Factors as Therapeutic Targets  

Microsoft Academic Search

\\u000a Secreted growth factors directed from malignant cell to malignant cell, malignant cell to stromal cells, vascular cells and\\u000a immune system cells or from stromal cells, vascular cells and immune system cells to malignant cells are essential for the\\u000a growth and progression of malignant disease. Proangiogenic factors including members of the vascular endothelial growth factor\\u000a (VEGF)-A family, placental growth factor, members

Beverly A. Teicher

196

Cellular signaling by fibroblast growth factor receptors  

Microsoft Academic Search

The 22 members of the fibroblast growth factor (FGF) family of growth factors mediate their cellular responses by binding to and activating the different isoforms encoded by the four receptor tyrosine kinases (RTKs) designated FGFR1, FGFR2, FGFR3 and FGFR4. Unlike other growth factors, FGFs act in concert with heparin or heparan sulfate proteoglycan (HSPG) to activate FGFRs and to induce

V. P. Eswarakumar; I. Lax; J. Schlessinger

2005-01-01

197

Expression of Growth Factors in Dictyostelium discoideum  

Microsoft Academic Search

Growth factors and their binding proteins are important proteins regulating mammalian cell proliferation and differentiation so there is considerable interest in producing them as recombinant proteins, especially in hosts that do not already produce a complex mixture of growth factors. Many growth factors require post- translational modifications making them unsuitable for production in Escherichia coli or other prokaryotes. Since several

Sassan Asgari; Sharmila Arun; Martin B. Slade; John Marshall; Keith L. Williams; John F. Wheldrake

198

Growth cone responses to growth and chemotropic factors.  

PubMed

During nervous system development axons reach their target areas under the influence of numerous guidance cues that affect rate and direction of growth. This report addresses the unsettled question of whether and to what extent growth velocity and turning responses (attraction, repulsion) are interdependent. We exposed individual growth cones of fetal rat dorsal root ganglion neurons in culture asymmetrically to gradients of seven different factors and recorded their growth rates and turning angles. Growth cones exhibited divergent patterns of turning and growth responses. For example, hepatocyte growth factor (HGF), insulin-like growth factor-1 (IGF-1) and thrombin all promoted growth, but HGF was a powerful attractant, thrombin a potent repellent and IGF-1 did not elicit turning. Galanin and neuropeptide Y also affected growth and/or turning differentially. Finally, nerve growth factor in the culture medium not only inhibited the turning responses to HGF, but also converted growth promotion of HGF and IGF-1 into inhibition. Overall, our studies indicate that: (i) turning and advance are regulated independently, except that strong attractive or repulsive responses generally are accompanied by growth promotion; (ii) asymmetric growth factor application per se does not elicit attraction; (iii) regulation of the two parameters may occur through a single receptor; and (iv) the effects of combined growth factors may not be additive and can be inhibitory. PMID:18702698

Sanford, Staci D; Gatlin, Jesse C; Hökfelt, Tomas; Pfenninger, Karl H

2008-07-01

199

Participation of Gab1 and Gab2 in IL-22-mediated keratinocyte proliferation, migration, and differentiation.  

PubMed

Interleukin-22 (IL-22) is one of the key mediators of keratinocyte alterations in psoriasis. IL-22 inhibits keratinocyte differentiation and induces the migration of human keratinocytes. Grb2-associated binder 1 (Gab1) has been shown to mediate epidermal growth factor-induced epidermal growth and differentiation via interaction with the Src homology-2-containing protein-tyrosine phosphatase (Shp2). In this investigation, we explore the role of Gab1 and Gab2 in IL-22-mediated keratinocyte activities. We show that both Gab1 and Gab2 were tyrosine phosphorylated in IL-22-stimulated HaCaT cells and human primary epidermal keratinocytes and contributed to the activation of Extracellular signal regulated kinase 1/2 (Erk1/2) through interaction with Shp2. We further demonstrate that HaCaT cells infected with adenoviruses expressing Shp2-binding-defective Gab1/2 mutants exhibited decreased cell proliferation and migration, as well as increased differentiation. Moreover, similar results were observed in HaCaT cells infected with adenovirus-based small interfering RNAs targeting Gab1 and/or Gab2. Altogether, these data underscore the critical roles of Gab1 and Gab2 in IL-22-mediated HaCaT cell proliferation, migration, and differentiation. PMID:22851227

Zhu, Xiaofang; Li, Zhongliang; Pan, Wenyan; Qin, Lu; Zhu, Guoqiang; Ke, Yuehai; Wu, Jie; Bo, Ping; Meng, Songshu

2012-08-01

200

Expression profiling of human epidermal keratinocyte response following 1-minute JP-8 exposure.  

PubMed

The cDNA microarray analysis of 9600 expressed sequence tags was performed to examine the gene expression changes in human epidermal keratinocytes after 1-minute JP-8 exposure; 151 genes were identified as JP-8 responsive and classified into 8 clusters by self organization map. Genes involved in basal transcription and translations were up-regulated, whereas genes related to DNA repair, metabolism, and keratin were mostly down-regulated. Genes encoded for growth factors, apoptosis, signal transduction, and adhesion were also altered. These results indicated that human keratinocyte responds to a single dose of JP-8 insult and revealed several cellular processes previously not associated with jet fuel exposure. PMID:16835149

Chou, Chi-Chung; Yang, Jen-Hung; Chen, San-Duo; Monteiro-Riviere, Nancy A; Li, Han-Ni; Chen, Jeremy J W

2006-01-01

201

Growth Regulation of Skin Cells by Epidermal Cell-Derived Factors: Implications for Wound Healing  

Microsoft Academic Search

Epidermal cell-derived factors (EDF), present in extracts and supernatant fluids of cultured epidermal cells, were found to stimulate the proliferation of keratinocytes but to inhibit fibroblasts. In vitro, the effect of EDF on epiermal cells resulted in an increased number of rapidly proliferating colonies composed mainly of basal keratinocytes. Control cultures grown in the absence of EDF had a high

M. Eisinger; S. Sadan; I. A. Silver; R. B. Flick

1988-01-01

202

Palmitic Acid Induces Production of Proinflammatory Cytokines Interleukin-6, Interleukin-1?, and Tumor Necrosis Factor-? via a NF-?B-Dependent Mechanism in HaCaT Keratinocytes  

PubMed Central

To investigate whether palmitic acid can be responsible for the induction of inflammatory processes, HaCaT keratinocytes were treated with palmitic acid at pathophysiologically relevant concentrations. Secretion levels of interleukin-6 (IL-6), tumor necrosis factor-? (TNF-?), interleukin-1? (IL-1?), NF-?B nuclear translocation, NF-?B activation, Stat3 phosphorylation, and peroxisome proliferator-activated receptor alpha (PPAR?) mRNA and protein levels, as well as the cell proliferation ability were measured at the end of the treatment and after 24 hours of recovery. Pyrrolidine dithiocarbamate (PDTC, a selective chemical inhibitor of NF-?B) and goat anti-human IL-6 polyclonal neutralizing antibody were used to inhibit NF-?B activation and IL-6 production, respectively. Our results showed that palmitic acid induced an upregulation of IL-6, TNF-?, IL-1? secretions, accompanied by NF-?B nuclear translocation and activation. Moreover, the effect of palmitic acid was accompanied by PPAR? activation and Stat3 phosphorylation. Palmitic acid-induced IL-6, TNF-?, IL-1? productions were attenuated by NF-?B inhibitor PDTC. Palmitic acid was administered in amounts able to elicit significant hyperproliferation and can be attenuated by IL-6 blockage. These data demonstrate for the first time that palmitic acid can stimulate IL-6, TNF-?, IL-1? productions in HaCaT keratinocytes and cell proliferation, thereby potentially contributing to acne inflammation and pilosebaceous duct hyperkeratinization.

Zhou, Bing-rong; Zhang, Jia-an; Zhang, Qian; Xu, Yang; Wu, Di; Yin, Zhi-qiang; Luo, Dan

2013-01-01

203

Carrageenans inhibit growth-factor binding.  

PubMed Central

Carrageenans, a family of polysulphated carbohydrates, inhibited binding of basic fibroblast growth factor (bFGF), transforming growth factor beta 1 (TGF beta 1) and platelet-derived growth factor (PDGF). iota-Carrageenan was the most potent bFGF antagonist (IC50 = 0.4 +/- 0.1 microgram/ml), kappa-carrageenan was the most potent PDGF antagonist (IC50 = 1.7 +/- 1.3 micrograms/ml) and lambda-carrageenan was the most potent TGF beta 1 antagonist (IC50 = 19 +/- 2 micrograms/ml). None of the carrageenans, at concentrations up to 200 micrograms/ml, inhibited binding of insulin-like growth factor 1 or transforming growth factor alpha. Carrageenans are selective growth-factor antagonists and have potential for the treatment of disorders associated with the over-production of certain growth factors.

Hoffman, R

1993-01-01

204

Growth Factors and Tension-Induced Skeletal Muscle Growth.  

National Technical Information Service (NTIS)

The project investigated biochemical mechanisms to enhance skeletal muscle growth, and developed a computer based mechanical cell stimulator system. The biochemicals investigated in this study were insulin/(Insulin like Growth Factor) IGF-1 and Steroids. ...

H. H. Vandenburgh

1994-01-01

205

Double-stranded RNA induces MMP-9 gene expression in HaCaT keratinocytes by tumor necrosis factor-?.  

PubMed

Viral double-stranded RNA (dsRNA) and its synthetic analog poly (I:C) are recognized via multiple pathways and induce the expression of genes related to inflammation. In the present study, we demonstrate that poly (I:C) specifically induced the expression of matrix metallo-proteinase-9 (MMP-9) in HaCaT keratinocytes. Studies using specific pharmacological inhibitors revealed the involvement of NF-?B, p38 MAPK, and PI-3K signal transduction pathways in poly (I:C)-induced MMP-9 gene expression. MMP-9 gene induction was sensitive toward treatment with the macrolide antibiotic bafilomycin A1, a vacuolar H(+)-ATPase inhibitor, and with the lysosomotropic agent chloroquine. However, cycloheximide treatment only partially blocked poly (I:C)-induced MMP-9 gene expression. Although HaCaT keratinocytes produce a number of cytokines and chemokines in response to poly (I:C), stimulation experiments revealed that exclusively TNF? strongly promoted MMP-9 gene expression. During the antiviral response MMP-9 expression may be of importance for the tissue injury phase. PMID:21428909

Voss, Andreas; Gescher, Kirsten; Hensel, Andreas; Nacken, Wolfgang; Kerkhoff, Claus

2011-06-01

206

Peptide growth factor interactions in embryonic and fetal growth.  

PubMed

Peptide growth factors are expressed by multiple tissues in the animal and human embryo and fetus. They undergo specific interactions which control the rate of cellular proliferation, tissue differentiation and the induction of specific morphogenic events such as mesoderm formation in the embryo. Biologic control may not only be exerted at the level of growth factor synthesis and receptor expression but by the sequestration and storage of growth factors by extracellular matrix molecules. In the case of insulin-like growth factors (IGFs), storage maybe mediated by attachment to specific IGF-binding proteins which may additionally modulate biological potency. Basic fibroblast growth factor (basic FGF) and transforming growth factor-beta (TGF beta) directly bind to glycosaminoglycan molecules. Release of growth factors from these stores may be by local proteolytic action. A sequential expression of basic FGF, IGF-II and TGF beta occurs in the ovine fetal epiphyseal growth plate as chondrocytes progress from a proliferative to a postmitotic, hypertrophic state. Cellular phenotype may be largely explained by the relative amounts of these autocrine growth factors within the growth plate. PMID:1307735

Hill, D J

1992-01-01

207

Appearance of heparin-binding EGF-like growth factor in wound fluid as a response to injury.  

PubMed Central

Wound fluid was obtained from porcine partial-thickness excisional wounds and analyzed for heparin-binding growth factors. Two heparin-binding growth factor activities were detected, a relatively minor one that was eluted from a heparin affinity column with 0.65 M NaCl and a major one that was eluted with 1.1 M NaCl. These activities were not present in wound fluid 1 hr after injury but appeared 1 day after injury, were maximal 2-3 days after injury, and were not detectable by 8 days after injury. The heparin-binding growth factor eluted with 0.65 M NaCl was identified as a platelet-derived growth factor (PDGF)-like activity by the use of specific anti-PDGF neutralizing antibodies. The heparin-binding growth factor eluted with 1.1 M NaCl was shown to be structurally related to heparin-binding epidermal growth factor (EGF)-like growth factor (HB-EGF) by several criteria, including binding to heparin affinity columns and elution with 1.1 M NaCl, competition with the binding of 125I-EGF to the EGF receptor, triggering phosphorylation of the EGF receptor, immunodetection on a Western blot, and stimulation of fibroblast and keratinocyte growth. It was concluded that HB-EGF is a major growth factor component of wound fluid and, since it is mitogenic for fibroblasts and keratinocytes, that it might play an important role in wound healing. Images Fig. 4 Fig. 5

Marikovsky, M; Breuing, K; Liu, P Y; Eriksson, E; Higashiyama, S; Farber, P; Abraham, J; Klagsbrun, M

1993-01-01

208

Immortalization of normal human gingival keratinocytes and cytological and cytogenetic characterization of the cells.  

PubMed

Most in vitro studies of oral carcinogenesis in human cells are carried out with oral keratinocytes immortalized by human papillomavirus type 16 DNA. However, because various etiological factors for oral cancer are known, it is important to establish new human keratinocyte cell lines useful for studying the mechanism of oral carcinogenesis. Normal human gingival keratinocytes in secondary cultures grown in serum-free medium were either transfected with origin (-) SV40 DNA or sequentially transfected with origin (-) SV40 DNA and human c-fos. The transfected cells were continually passaged and analyzed for cytological and cytogenetic characterizations. Four immortal cell lines were grown for over 1100 days in culture and maintained a vigorous growth for over 250 population doublings. They expressed SV40 T antigen, cytokeratins 8 and 18, and E-cadherin, and overexpressed the c-Fos protein. The immortal cell lines had telomerase activity but lacked transformed phenotypes on soft agar or in nude mice. Each cell line had nonrandom chromosomal abnormalities and minisatellite alterations. One of the immortal cell lines, NDUSD-1, retained the capability to deposit calcium, which was also demonstrated in normal human gingival keratinocytes by alizarin red staining, indicating the possibility that NDUSD-1 cells may retain some natural characteristics of normal gingival keratinocytes. Because the oral ectoderm plays an important role in tooth development, these immortal cell lines may be useful in various experimental models for investigations of oral biology and oral carcinogenesis. PMID:19184294

Kubo, Chikahiro; Tsutsui, Takeo W; Tamura, Yukiko; Kumakura, Shin-Ichi; Tsutsui, Takeki

2009-01-29

209

The titanium surface texture effects adherence and growth of human gingival keratinocytes and human maxillar osteoblast-like cells in vitro.  

PubMed

The adhesion, orientation and proliferation of human gingival epithelial cells and human maxillar osteoblast-like cells in primary and secondary culture were studied on glossy polished, sandblasted and plasma-sprayed titanium surfaces by scanning electron microscopy and in thin sections. The primary cultured explants of human gingival epithelial cells attached, spread and proliferated on all titanium surfaces with the greatest extension on the polished and the smallest extension on plasma-sprayed surfaces. In secondary suspension cultures of gingival keratinocytes, attachment spreading and growth was only observed on polished and plasma-sprayed surfaces, but not on sandblasted surfaces. Moreover, the attachment of these cells depended on the seeding concentration as well as on the coating with fetal calf serum. Cells on polished surfaces developed an extremely flat cell shape, but on sandblasted and plasma-sprayed surfaces a more cuboidal shape. In contrast human maxillar osteoblasts seeded as secondary suspension cultures attached very well to all three differently textured titanium surfaces and showed identical growth patterns independent of the titanium surface structure. These findings suggest that cell morphology, orientation, proliferation and adhesion of human gingival epithelial cells in primary or secondary culture are dependent on the texture of the titanium surface whereas no such differences were observed for maxillar osteoblast-like cells. In conclusion, the soft tissue integration and response is more influenced by the surface texture than the process of osseointegration. PMID:11545315

Lauer, G; Wiedmann-Al-Ahmad, M; Otten, J E; Hübner, U; Schmelzeisen, R; Schilli, W

2001-10-01

210

Design and Synthesis of Binding Growth Factors  

PubMed Central

Growth factors play important roles in tissue regeneration. However, because of their instability and diffusible nature, improvements in their performance would be desirable for therapeutic applications. Conferring binding affinities would be one way to improve their applicability. Here we review techniques for conjugating growth factors to polypeptides with particular affinities. Conjugation has been designed at the level of gene fusion and of polypeptide ligation. We summarize and discuss the designs and applications of binding growth factors prepared by such conjugation approaches.

Tada, Seiichi; Kitajima, Takashi; Ito, Yoshihiro

2012-01-01

211

G alpha(q/11)-coupled P2Y2 nucleotide receptor inhibits human keratinocyte spreading and migration.  

PubMed

Reepithelialization is a critical step in wound healing. It is initiated by keratinocyte migration at the wound edges. After wounding, extracellular nucleotides are released by keratinocytes and other skin cells. Here, we report that activation of P2Y2 nucleotide receptor by ATP/UTP inhibits keratinocyte cell spreading and induces lamellipodium withdrawal. Kymography analysis demonstrates that these effects correlate with a durable decrease of lamellipodium dynamics. P2Y2 receptor activation also induces a dramatic dismantling of the actin network, the loss of alpha3 integrin expression at the cell periphery, and the dissolution of focal contacts as indicated by the alteration of alpha(v) integrins and focal contact protein distribution. In addition, activation of P2Y2R prevents growth factor-induced phosphorylation of Erk(1,2) and Akt/PkB. The use of a specific pharmacological inhibitor (YM-254890), the depletion of G alpha(q/11) by siRNA, or the expression of a constitutively active G alpha(q/11) mutant (Q209L) show that activation of G alpha(q/11) is responsible for these ATP/UTP-induced effects. Finally, we report that ATP delays growth factor-induced wound healing of keratinocyte monolayers. Collectively, these findings provide evidence for a unique and important role for extracellular nucleotides as efficient autocrine/paracrine regulators of keratinocyte shape and migration during wound healing. PMID:17609252

Taboubi, Salma; Milanini, Julie; Delamarre, Estelle; Parat, Fabrice; Garrouste, Françoise; Pommier, Gilbert; Takasaki, Jun; Hubaud, Jean-Claude; Kovacic, Hervé; Lehmann, Maxime

2007-07-03

212

Fetal growth factors and fetal nutrition.  

PubMed

Optimal fetal growth is important for a healthy pregnancy outcome and also for lifelong health. Fetal growth is largely regulated by fetal nutrition, and mediated via the maternal and fetal glucose/insulin/insulin-like growth factor axes. Fetal nutrition may reflect maternal nutrition, but abnormalities of placental function can also affect fetal growth, as the placenta plays a key intermediary role in nutritional signalling between mother and fetus. Fetal nutrition also impacts on the development of key fetal endocrine systems such as the glucose-insulin and insulin-like growth factor axes. This is likely to contribute to the link between both fetal growth restriction and fetal overgrowth, and increased risks of obesity and impaired glucose tolerance in later life. This review focuses on the associations between maternal and fetal nutrition, fetal growth and later disease risk, with particular emphasis on the role of insulin-like growth factors and the importance of the periconceptional period. PMID:23639574

Bloomfield, F H; Spiroski, Ana-Mishel; Harding, J E

2013-04-30

213

Ligand activation of peroxisome proliferator-activated receptor-?\\/?(PPAR?\\/?) inhibits cell growth of human N\\/TERT1 keratinocytes  

Microsoft Academic Search

The functional role of peroxisome proliferator-activated receptor-?(PPAR?; also referred to as PPAR?) in epidermal cell growth remains controversial. Recent evidence suggests that ligand activation of PPAR?\\/? increases cell growth and inhibits apoptosis in epidermal cells. In contrast, other reports suggest that ligand activation of PPAR?\\/? leads to the induction of terminal differentiation and inhibition of cell growth. In the present

Andrew D. Burdick; Moses T. Bility; Elizabeth E. Girroir; Andrew N. Billin; Timothy M. Willson; Frank J. Gonzalez; Jeffrey M. Peters

2007-01-01

214

Regulation of Growth Factor Receptors by Gangliosides  

NSDL National Science Digital Library

Growth factor receptors are important in controlling many cellular functions, such as growth, differentiation, and disease. Growth factor receptors activate numerous signal transduction pathways within cells; however, how one growth factor receptor orchestrates multiple signal transduction pathways is not clear. This review focuses on a ubiquitous component of the plasma membrane, called "gangliosides," and how they modulate growth factor receptors at the cell membrane. Gangliosides are complex structures that consist of two parts--a lipid ceramide moiety and a carbohydrate head structure. Studies over the past two decades have demonstrated that different gangliosides can enhance or inhibit growth factor receptor activity. However, ganglioside modulation of growth factor receptors is more complex than simply stimulation or inhibition. We present and discuss three models of how gangliosides regulate growth factor receptors: (i) modulation of ligand binding, (ii) regulation of receptor dimerization, and (iii) regulation of receptor activation state and subcellular distribution. On the basis of these models, we speculate about the physiological consequences of ganglioside regulation of growth factor receptors.

Erik A. Miljan (Chicago;Children's Memorial Medical Center REV); Eric G. Bremer (Chicago;Children's Memorial Medical Center REV)

2002-11-26

215

Autocrine growth factors and solid tumor malignancy.  

PubMed Central

The ability of malignant cells to escape the constraint that normally regulate cell growth and differentiation has been a primary focus of attention for investigators of cancer cell biology. An outcome of this attention has been the discovery that the protein products of oncogenes play a role in the activation of growth signal pathways. A second outcome, possibly related to abnormal oncogene expression, has been the discovery that malignant cells frequently show an ability to regulate their own growth by the release of autocrine growth modulatory substances. Most important, the growth of certain malignant cell types has been shown to depend on autocrine growth circuits. A malignant tumor whose continued growth depends on the release of an autocrine growth factor may be vulnerable to treatment with specific receptor antagonists or immunoneutralizing antibodies designed to break the autocrine circuit. Information is rapidly emerging concerning autocrine growth factors in selected human solid tissue malignancy. Images

Walsh, J. H.; Karnes, W. E.; Cuttitta, F.; Walker, A.

1991-01-01

216

Roles for Growth Factors in Cancer Progression  

PubMed Central

Under physiological conditions, cells receive fate-determining signals from their tissue surroundings, primarily in the form of polypeptide growth factors. Integration of these extracellular signals underlies tissue homeostasis. Although departure from homeostasis and tumor initiation are instigated by oncogenic mutations rather than by growth factors, the latter are the major regulators of all subsequent steps of tumor progression, namely clonal expansion, invasion across tissue barriers, angiogenesis, and colonization of distant niches. Here, we discuss the relevant growth factor families, their roles in tumor biology, as well as the respective downstream signaling pathways. Importantly, cancer-associated activating mutations that impinge on these pathways often relieve, in part, the reliance of tumors on growth factors. On the other hand, growth factors are frequently involved in evolvement of resistance to therapeutic regimens, which extends the roles for polypeptide factors to very late phases of tumor progression and offers opportunities for cancer therapy.

Witsch, Esther; Sela, Michael; Yarden, Yosef

2011-01-01

217

Growth factor transgenes interactively regulate articular chondrocytes.  

PubMed

Adult articular chondrocytes lack an effective repair response to correct damage from injury or osteoarthritis. Polypeptide growth factors that stimulate articular chondrocyte proliferation and cartilage matrix synthesis may augment this response. Gene transfer is a promising approach to delivering such factors. Multiple growth factor genes regulate these cell functions, but multiple growth factor gene transfer remains unexplored. We tested the hypothesis that multiple growth factor gene transfer selectively modulates articular chondrocyte proliferation and matrix synthesis. We tested the hypothesis by delivering combinations of the transgenes encoding insulin-like growth factor I (IGF-I), fibroblast growth factor-2 (FGF-2), transforming growth factor beta1 (TGF-?1), bone morphogenetic protein-2 (BMP-2), and bone morphogenetic protien-7 (BMP-7) to articular chondrocytes and measured changes in the production of DNA, glycosaminoglycan, and collagen. The transgenes differentially regulated all these chondrocyte activities. In concert, the transgenes interacted to generate widely divergent responses from the cells. These interactions ranged from inhibitory to synergistic. The transgene pair encoding IGF-I and FGF-2 maximized cell proliferation. The three-transgene group encoding IGF-I, BMP-2, and BMP-7 maximized matrix production and also optimized the balance between cell proliferation and matrix production. These data demonstrate an approach to articular chondrocyte regulation that may be tailored to stimulate specific cell functions, and suggest that certain growth factor gene combinations have potential value for cell-based articular cartilage repair. PMID:23097312

Shi, Shuiliang; Mercer, Scott; Eckert, George J; Trippel, Stephen B

2013-04-01

218

[Tissue proliferation by thrombocyte growth factor].  

PubMed

An essay for determining the growth stimulating activity of human platelets has been established. With the aid of this system a mitogenic factor from crude platelet extract was isolated. Besides a stimulation of DNA-synthesis an enhanced synthesis of collagen and glycosaminoglycans is induced by the platelet growth factor. PMID:6510788

Dresow, B; Delbrück, A

1984-12-01

219

Efficacy of palifermin (keratinocyte growth factor-1) in the amelioration of oral mucositis  

PubMed Central

Purpose: Oral mucositis is a significant toxicity of cytotoxic chemo- and radiation-therapy used to treat cancer. Palifermin is the first pharmaceutical/biological agent approved for the intervention of oral mucositis. The major objective of this review is to evaluate the evidence supporting the use of palifermin. Methods: A literature search was performed using an appropriate keyword search in MEDLINE and PubMed databases. Results: Of 100 full papers and 4 abstracts identified, 12 papers and 3 abstracts were appropriate for analysis. Level 2 evidence supporting palifermin use in patients with hematologic malignancies being treated with autologous hematopoietic stem cell transplantation (HSCT) is clear. Level 2 evidence also exists for the use of palifermin in the prevention of oral mucositis in patients with solid tumors (colorectal cancer, head and neck cancer), but is incomplete. Level ? 3 data support the use of palifermin in allogeneic HSCT recipients and cycled chemotherapy. A single health economic study concluded that palifermin is essentially cost neutral in the autologous HSCT population. Conclusion: Data supporting the use of palifermin in autologous HSCT recipients with hematologic malignancies is clear. Some data exist demonstrating its efficacy in other oncologic indications. Additional studies are needed to broaden the potential applications of palifermin and to ascertain its economic, but not symptomatic, effectiveness.

Sonis, Stephen T

2010-01-01

220

Activated keratinocytes in the epidermis of hypertrophic scars.  

PubMed Central

The etiology of hypertrophic scarring, a pathological end point of wound healing, is unknown. The scars most commonly occur when epithelialization has been delayed during, for example, the healing of deep dermal burn wounds. Hypertrophic scars are conventionally described as a dermal pathology in which the epidermis has only a passive role. In this study, the expression of keratin intermediate filament proteins and filaggrin has been investigated in the epidermis of hypertrophic scars and site-matched controls from the same patients. Hypertrophic scar epidermis was found to express the hyperproliferative keratins K6 and K16 in interfollicular epidermis in association with K17 and precocious expression of filaggrin. K16 mRNA was localized by in situ hybridization using a highly specific cRNA probe. In contrast to the immunohistochemical location of K16 protein, the K16 mRNA was found to be expressed in the basal cell layer of normal skin. In hypertrophic scars the mRNA distribution corroborated the abnormal K16 protein distribution. These results suggest the keratinocytes in hypertrophic scar epidermis have entered an alternative differentiation pathway and are expressing an activated phenotype. Activated keratinocytes are a feature of the early stages of wound healing producing growth factors that influence fibroblasts, endothelial cells, and the inflammatory response. We propose that cellular mechanisms in the pathogenesis of hypertrophic scarring are more complex than isolated dermal phenomena. The persistence of activated keratinocytes in hypertrophic scar epidermis implicates abnormal epidermal-mesenchymal interactions. Images Figure 1 Figure 3

Machesney, M.; Tidman, N.; Waseem, A.; Kirby, L.; Leigh, I.

1998-01-01

221

A keratinocyte-specific transcription factor, KRF-1, interacts with AP-1 to activate expression of human papillomavirus type 18 in squamous epithelial cells.  

PubMed Central

Human papillomavirus type 18 (HPV-18) infects genital squamous epithelium and is an etiological agent of cervical cancer. Cell-type-specific expression of HPV-18 is directed by the region upstream of the viral early genes that contains a transcriptional enhancer whose function is dependent solely on cellular factors. This element directs expression to high levels in squamous epithelial cells but is only weakly active in other cell types. We demonstrate by gel mobility-shift, methylation interference, and mutational analysis that the binding of two distinct factors to the enhancer is necessary for cell-type-specific transcriptional activation. One of these factors is identified as a keratinocyte-specific transcriptional activator, which we call KRF-1, while the other is a member of the AP-1 family. We also find that Oct-1 competes with KRF-1 for binding to enhancer sequences though it does not contribute to transcriptional activation. These results suggest a complex interplay of ubiquitous and cell-type-restricted transcriptional factors in the tissue- and differentiation-specific expression of HPV-18. Images

Mack, D H; Laimins, L A

1991-01-01

222

Growth factors during ovarian Angiogenesis  

Microsoft Academic Search

\\u000a As recognized by Hudlická, capillary growth in normal adult tissues is indeed a rare event, and the endothelium represents\\u000a an extremely stable population of cells with a low mitotic activity (Denekamp, 1984; Hudlická, 1984). This observation is\\u000a not surprising, because physiologic angiogenesis is usually associated with tissue growth or repair, and most normal adult\\u000a tissues are relatively stable (Hudlická, 1984;

Anna T. Grazul-Bilska; Dale A. Redmer; Lawrence P. Reynolds

223

Transcriptional enhancer factor (TEF)-1 and its cell-specific co-activator activate human papillomavirus-16 E6 and E7 oncogene transcription in keratinocytes and cervical carcinoma cells.  

PubMed Central

The human papillomavirus (HPV)-16 oncogenes, E6 and E7, are transcribed preferentially in keratinocytes and cervical carcinoma cells due to a 5' enhancer. An abundant peptide binding to a 37 nt enhancer element was purified from human keratinocytes by sequence-specific DNA chromatography. This protein was identified as transcriptional enhancer factor (TEF)-1 by complex mobility, binding to wild-type and mutant SV40 and HPV-16 enhansons and antigenic reactivity with two anti-TEF-1 antibodies. TEF-1 is cell-specific, but its transactivation also depends on a limiting, cell-specific TEF-1 'co-activator'. We show that both TEF-1 and the TEF-1 co-activator are active in human keratinocytes and essential for HPV-16 transcription. TEF-1 binding in vivo was necessary for HPV-16 P97 promoter activity. Excess TEF-1 and chimeric GAL4-TEF-1 specifically inhibited the P97 promoter by 'squelching', indicating that HPV-16 transcription also requires a limiting TEF-1 co-activator. TEF-1 and the TEF-1 co-activator functions mirrored HPV-16 transcription by their presence in keratinocytes and cervical carcinoma cells and their absence from lymphoid B-cells, but also functioned in liver cells where the HPV-16 promoter is inactive. TEF-1 and its associated co-activator are thus part of a complex mechanism which determines the restricted cell range of the HPV-16 E6 and E7 oncogene promoter. Images

Ishiji, T; Lace, M J; Parkkinen, S; Anderson, R D; Haugen, T H; Cripe, T P; Xiao, J H; Davidson, I; Chambon, P; Turek, L P

1992-01-01

224

Factor Proportions, Trade, and Growth  

Microsoft Academic Search

The standard version of the Heckscher-Ohlin model of international trade treats the factors of production--land, labor, and capital--as essentially analytically similar and symmetrical. In these six essays Ronald Findlay explores modifications to the factor proportions model, looking in particular at what happens when human capital and land use are allowed to vary endogenously. Findlay extends the factor proportions theory of

Ronald Findlay

225

Hereditary Factors in Human Growth.  

National Technical Information Service (NTIS)

Growth curves were computed by an IBM 1620 for 31 fraternal and 29 identical pairs of twins between the ages of 3 and 5. The formula used was Y = a + bx + cx sq. where Y is height and x is the age in days. This parabola was found to give a good fit over t...

S. G. Vandenberg F. Falkner

1965-01-01

226

Cultured Human Trabecular Meshwork Cells Express Functional Growth Factor Receptors  

Microsoft Academic Search

RESULTS. Amplification products of the expected size for 15 growth factor receptors were detected in cultured HTM cells and in ex vivo HTM tissues. The administration of exogenous growth factors showed that (a) hepatocyte growth factor (HGF), epidermal growth factor (EGF), insulinlike growth factor (IGF)-1, tumor necrosis factor (TNF) a, platelet-derived growth factor (PDGF)-AA, PDGF-BB, PDGF-AB, and basic fibroblast growth

Robert J. Wordinger; Abbot F. Clark; Rajnee Agarwal; Wendi Lambert; Loretta McNatt; Steven E. Wilson; Z Qu; Bernard K.-K. Fung

227

Environmental factors influencing growth and pubertal development.  

PubMed Central

Postnatal growth is based on hereditary signals and environmental factors in a complex regulatory network. Each factor must be in an optimal state for normal growth of the child. Fetal conditions may also have consequences on postnatal height. Intrauterine growth retardation can be recovered postnatally, although postnatal growth remains depressed in about one-third of cases. After birth, the environment may exert either a positive or negative effect on growth. In underdeveloped countries, malnutrition plays a major role in inhibiting the growth process. Children from families of higher socioeconomic classes are taller than their coevals in the lower socioeconomic groups. Urbanization also has a positive effect on growth. Better child care is supported by sufficient food supply, appropriate health and sanitation services, and a higher level of education. Over the last century, these factors have induced a taller stature and a more rapid maturity in Europe, North America, and Australia; a phenomenon which has been referred to as "the secular trend" in growth. Recently, a secular trend has also been reported in some developing countries. Although urbanization in general appears to be associated with better conditions of living, this is not the case in the slums of South America or in Africa where rural children are better off than children living in the poor cities. This paper describes in more detail the different hereditary and environmental factors that act during the fetal period and postnatally, and which play a role in human growth and pubertal development.

Delemarre-van de Waal, H A

1993-01-01

228

Factor-binding element in the human c-myc promoter involved in transcriptional regulation by transforming growth factor beta 1 and by the retinoblastoma gene product.  

PubMed Central

Previous studies have shown that transforming growth factor beta 1 (TGF-beta 1) inhibition of keratinocyte proliferation involves suppression of c-myc transcription, and indirect evidence has suggested that the retinoblastoma gene product (pRB) may be involved in this process. In this study, transient expression of pRB in skin keratinocytes was shown to repress transcription of the human c-myc promoter as effectively as TGF-beta 1. The same c-myc promoter region was required for regulation by both TGF-beta 1 and pRB. These sequences, termed the TGF-beta control element (TCE), lie between positions -86 and -63 relative to the P1 transcription start site. Oligonucleotides containing the TCE bound to several nuclear factors in mobility-shift assays using extracts from cells with or without normal pRB. Binding of some factors was inhibited by TGF-beta 1 treatment of TGF-beta-sensitive but not TGF-beta-insensitive cells. These data indicate that pRB can suppress c-myc transcription and suggest the involvement of cellular factors in addition to pRB in the TGF-beta 1 pathway for the inhibition of c-myc transcription and growth inhibition. Images

Pietenpol, J A; Munger, K; Howley, P M; Stein, R W; Moses, H L

1991-01-01

229

Growth Factors and Neuropathic Pain  

Microsoft Academic Search

A treatment for neuropathic pain is an important unmet medical need because this pain often is refractory to many medical\\u000a interventions. An important element in the development of neuropathic pain is a dysfunction in the activity of peripheral\\u000a nerves. Because neurotrophic factors affect nerve development and maintenance, modulating the activity of these factors can\\u000a alter neuronal pathophysiology and produce a

Michael H. Ossipov

2011-01-01

230

Acidic Fibroblast Growth Factor Promotes Vascular Repair  

NASA Astrophysics Data System (ADS)

Intravascular injury to arteries can result in thickening of the intimal smooth muscle layer adjacent to the lumen by migration and proliferation of cells from the underlying medial smooth muscle layer accompanied by deposition of extracellular matrix. This pathological response, which decreases lumen diameter, might, in part, be the result of the access of smooth muscle cells to plasma and platelet-derived growth factors as a consequence of denudation of the overlying confluent monolayer of vascular endothelial cells. Injured rat carotid arteries were treated by i.v. administration of acidic fibroblast growth factor, a heparin-binding protein that is chemotactic and mitogenic for vascular endothelial cells. The growth factor treatment resulted in dose-dependent inhibition of intimal thickening with parallel promotion of endothelial regeneration over the injured area. Therefore, acidic fibroblast growth factor might be efficacious in the prevention of restenosis caused by intimal thickening following angioplasty in humans.

Bjornsson, Thorir D.; Dryjski, Maciej; Tluczek, John; Mennie, Robert; Ronan, John; Mellin, Theodore N.; Thomas, Kenneth A.

1991-10-01

231

Growth Factor Antagonism in Breast Cancer Chemotherapy.  

National Technical Information Service (NTIS)

The primary focus of this project is the first step in the aberrant cell signaling pathways that lead to uncontrolled proliferation and cancer, namely the interaction of growth factors with their receptor tyrosine kinases (RTKs). Our principal goal is to ...

A. Hamilton

2000-01-01

232

Integration of Growth Factor and Nutrient Signaling  

Microsoft Academic Search

Signaling networks that promote cell growth are frequently dysregulated in cancer. One regulatory network, which converges on effectors such as 4EBP1 and S6K1, leads to growth by promoting protein synthesis. Here, we discuss how this network is regulated by both extracellular signals, such as growth factors, and intracellular signals, such as nutrients. We discuss how mutations amplifying either type of

Alykhan F. Shamji; Paul Nghiem; Stuart L. Schreiber

2003-01-01

233

Controlled delivery of heparin-binding EGF-like growth factor yields fast and comprehensive wound healing.  

PubMed

Wound healing is a dynamic process that relies on coordinated signaling molecules to succeed. Heparin-binding epidermal growth factor (EGF)-like growth factor (HB-EGF) is proven to accelerate healing, however precise control over its application is necessary to reduce side effects and achieve desired therapeutic benefit. To achieve effective growth factor delivery we designed a bioactive heparin-based coacervate. In vitro, HB-EGF released from the coacervate delivery system displayed enhanced bioactivity and promoted human keratinocyte migration while preserving cell proliferative capability. In a mouse excisional full-thickness wound model, controlled release of HB-EGF within the wound significantly accelerated wound closure more effectively than an equal dosage of free HB-EGF. Healing was induced by rapid re-epithelialization, granulation tissue formation, and accompanied by angiogenesis. Consistent with in vitro results, wounds treated with HB-EGF coacervate exhibited enhanced migration of keratinocytes with retained proliferative potential, forming a confluent layer for regained barrier function within 7 days. Collectively, these results suggest that coacervate-based controlled release of HB-EGF may serve as a new therapy to accelerate healing of cutaneous wounds. PMID:23154193

Johnson, Noah Ray; Wang, Yadong

2012-11-12

234

Addition of Epidermal Growth Factor Improves the Rate of Sulfur Mustard Wound Healing in an In Vitro Model  

PubMed Central

Objective: Sulfur mustard (SM) causes blisters on the human skin. These blisters delay healing of the skin and make the victims more susceptible to infection. In vitro models have been used for protection studies against SM injury, but study on wound healing after SM exposure has not been explored. The purpose of this study was to test whether the addition of exogenous growth factors could improve the rate of SM wound healing. Methods: The model consisted of normal human epidermal keratinocytes seeded into 6-well plates, exposed to SM, and wounded (disruption of the cell monolayer) with a sterile wounding instrument. Cells were then stained and images were captured to measure percentage wound fill. Epidermal growth factor (EGF) and keratinocyte growth factor (KGF) were tested in this model. Results: EGF (1 ng/mL) significantly increased wound fill on all of the days tested (days 6, 9, and 12). KGF did not significantly improve wound healing. Conclusions: EGF showed promise as a potential therapy for SM-induced wounds. This in vitro model was a valuable tool for screening therapeutics before animal testing. These results will be used to develop a dressing that can slowly release EGF on to a debrided wound bed to help speed the healing process.

Henemyre-Harris, Claudia L.; Adkins, Angela L.; Chuang, Augustine H.; Graham, John S.

2008-01-01

235

Factor Shares and Savings in Endogenous Growth  

Microsoft Academic Search

In models of steady investment-driven growth, an individual's propensity to save depends on how much of his income is drawn from accumulated factors of production ('capital') rather than from nonaccumulated factors. When agents are heterogeneous in this respect, growth-oriented policies have distributional consequences and, in the absence of lump-sum redistribution, their implementation faces political constraints. If the median voter is

Giuseppe Bertola

1993-01-01

236

TRANSFORMING GROWTH FACTOR ?S IN NEURODEGENERATIVE DISEASE  

Microsoft Academic Search

Transforming growth factors-?s (TGF-?s), a family of multifunctional peptide growth factors, affect cells of the central nervous system (CNS). The three mammalian TGF-? isoforms, TGF-?s 1, 2 and 3, are expressed in adult human brain. Since neuronal degeneration is a defining feature of CNS degenerative diseases, TGF-? may be important because it can influence neuronal survival. In vitro TGF-? promotes

KATHLEEN C FLANDERS; RENEÉ F REN; CAROL F LIPPA

1998-01-01

237

Calcium-Regulated Differentiation of Normal Human Epidermal Keratinocytes in Chemically Defined Clonal Culture and Serum-Free Serial Culture  

Microsoft Academic Search

An improved serum-free culture system has been developed for normal human epidermal keratinocytes (HK), Short-term clonal growth and differentiation studies are routinely performed in a defined medium consisting of optimized nutrient medium MCDB 153 supplemented with epidermal growth factor, insulin, hydrocortisone, ethanolamine, and phosphoethanolamine. A small amount of whole bovine pituitary extract (wBPE) is added for initiation of primary cultures,

Steven T. Boyce; Richard G. Ham

1983-01-01

238

Organic growth factor requirements of some yeasts.  

PubMed

Some sporogenous yeasts (Brettanomyces bruxellensis, Debaryomyces hansenii, Hansenula ciferrii, Hansenula polymorpha, Pichia polymorpha, Saccharomycopsis guttulata, and Saccharomyces chevalieri), isolated from various fruits have been examined for their organic growth factor requisites. H. ciferrii was completely deficient in thiamine, biotin, inositol, riboflavin, niacin, and partially deficient in pantothenic acid. It required an external supply of 0.1-1.0 ppm thiamine, 0.01-0.1 ppm biotin, 10.0 ppm inositol, 0.10 ppm niacin and riboflavin for its optimum growth. H. polymorpha showed partial deficiency only in xanthine. P. polymorpha gave indications of partial deficiencies in thiamine and biotin. S. guttulata was completely deficient in biotin, and partially deficient in adenine sulphate. It required 0.01 ppm biotin for optimum growth. S chevalieri was completely deficient in pyridoxine and partially deficient in thiamine. It required 0.1 ppm pyridoxine for maximum growth. D. hansenii and B bruxellensis were auxoautotrophic for the various growth factors studied. PMID:7242379

Madan, M; Gulati, N

1980-01-01

239

EFFECT OF ARSENICALS ON ULTRAVIOLET-RADIATION-INDUCED GROWTH ARREST AND RELATED SIGNALING EVENTS IN HUMAN KERATINOCYTES  

EPA Science Inventory

The molecular mechanisms mediating arsenic-induced carcinogenesis are not well understood. The role of confounding factors such as ultraviolet radiation (UV), add another level of complexity to the study of arsenic carcinogenesis and the cancer risk assessment to humans. We hypot...

240

Role of Platelet-derived Growth Factor and Vascular Endothelial Growth Factor in Obliterative Airway Disease  

Microsoft Academic Search

Rationale: Platelet-derived growth factor (PDGF) is an important smoothmusclecellmitogen,and vascularendothelialgrowth factor (VEGF) is a known angiogenic and proinflammatory growth factor. We hypothesized that specific therapy aimed at these growth fac- tors might inhibit the development of experimental obliterative airway disease (OAD). Methods: In fully mismatched rat tracheal allografts, we used ima- tinibandPTK\\/ZK,eitheraloneor incombination, toblockPDGFand VEGF receptor protein tyrosine kinase (RTK)

Jussi M. Tikkanen; Maria Hollmen; Antti I. Nykanen; Jeanette Wood; Petri K. Koskinen; Karl B. Lemstrom

2006-01-01

241

Transforming Growth Factor-« Acts as an Autocrine Growth Factor in Ovarian Carcinoma Cell Lines  

Microsoft Academic Search

The potential of transforming growth factor-a (TGF-a) to function as an autocrine growth factor was evaluated in numerous ovarian carcinoma cell lines. All 17 lines which were examined expressed the epidermal growth factor receptor and 16 cell lines, in addition, concomitantly secreted TGF-a. Radioimmunoassay of processed serum-free-conditioned medium indicated TGF-a concentrations ranging from 16 to 197 pg\\/ml, or 1.5 to

Kurt Stromberg; Theodore J. Collins; Alfred W. Gordon; Carolyn L. Jackson; Gibbes R. Johnson

242

860. Sustained Long-Term In Vivo Expression of Human Factor IX from Keratinocytes Transduced with HIV-Based Vectors  

Microsoft Academic Search

Hemophilia B is caused by a deficiency in coagulation factor IX (FIX), and is due to mutations in the factor IX gene. Patients suffer from severe bleeding disorders that may cause chronic tissue inflammation and degeneration. The only treatments currently available are paliative. Hemophilia B is a good candidate for cutaneous gene therapy, since factor levels as low as 1%

Angeles Escarti-Nebot; Fernando Serrano; Marcela del Rio; Fernando Larcher; Antonio Bernad

2006-01-01

243

Identification of copper/zinc superoxide dismutase as a nitric oxide-regulated gene in human (HaCaT) keratinocytes: implications for keratinocyte proliferation.  

PubMed Central

Recent studies have demonstrated an induction of expression of inducible nitric oxide synthase that is associated with several inflammatory diseases of the skin. To define the mechanisms of action of nitric oxide (NO) in the skin, we attempted to identify genes that are regulated by NO in keratinocytes. Using the human keratinocyte cell line HaCaT as a model system, we identified a Cu/Zn superoxide dismutase (SOD) that was strongly induced by high concentrations (500 microM) of NO-donating agents ¿S-nitrosoglutathione, sodium nitroprusside and (Z)-1-[2-(2-aminoethyl)-N-(2-ammonioethyl) amino] diazen-1-ium-1,2 -diolate (DETA-NO)¿, but not by serum or by single recombinant growth factors and inflammatory cytokines or by treatment with superoxide anions. Furthermore, endogenously produced NO increased the expression of Cu/Zn SOD mRNA in keratinocytes. Moreover, treatment of HaCaT cells with NO was associated with a biphasic effect on cell proliferation, because low doses (100 microM) of different NO donors (S-nitrosoglutathione and DETA-NO) mediated a proliferative signal to the cells, whereas high concentrations (500 microM) were cytostatic. To determine a possible correlation between the close regulation of Cu/Zn SOD expression and proliferation by NO in keratinocytes, we established a cell line (psp1CZ1N) carrying a human Cu/Zn SOD cDNA under the control of a ponasterone-inducible promoter construct. Ponasterone-induced overexpression of Cu/Zn SOD caused a cytostatic effect in proliferating psp1CZ1N cells. We therefore suggest that the up-regulation of Cu/Zn SOD expression by NO establishes an inhibitory mechanism on keratinocyte proliferation.

Frank, S; Kampfer, H; Podda, M; Kaufmann, R; Pfeilschifter, J

2000-01-01

244

Autologous keratinocyte suspension in platelet concentrate accelerates and enhances wound healing - a prospective randomized clinical trial on skin graft donor sites: platelet concentrate and keratinocytes on donor sites  

PubMed Central

Background Wound healing involves complex mechanisms, which, if properly chaperoned, can enhance patient recovery. The abilities of platelets and keratinocytes may be harnessed in order to stimulate wound healing through the formation of platelet clots, the release of several growth factors and cytokines, and cell proliferation. The aim of the study was to test whether autologous keratinocyte suspensions in platelet concentrate would improve wound healing. The study was conducted at the Lausanne University Hospital, Switzerland in 45 patients, randomized to three different topical treatment groups: standard treatment serving as control, autologous platelet concentrate (PC) and keratinocytes suspended in autologous platelet concentrate (PC?+?K). Split thickness skin graft donor sites were chosen on the anterolateral thighs of patients undergoing plastic surgery for a variety of defects. Wound healing was assessed by the duration and quality of the healing process. Pain intensity was evaluated at day five. Results Healing time was reduced from 13.9?±?0.5 days (mean?±?SEM) in the control group to 7.2?±?0.2 days in the PC group (P?keratinocytes in suspension further reduced the healing time to 5.7?±?0.2 days. Pain was reduced in both the PC and PC?+?K groups. Data showed a statistically detectable advantage of using PC?+?K over PC alone (P?keratinocytes in stimulating wound healing and reducing pain. This strikingly simple approach could have a significant impact on patient care, especially critically burned victims for whom time is of the essence. Clinical trial registry information Protocol Record Identification Number: 132/03 Registry URL: http://www.clinicaltrials.gov

2013-01-01

245

Growth factor effects on costal chondrocytes for tissue engineering fibrocartilage  

Microsoft Academic Search

Tissue-engineered fibrocartilage could become a feasible option for replacing tissues such as the knee meniscus or temporomandibular\\u000a joint disc. This study employed five growth factors (insulin-like growth factor-I, transforming growth factor-?1, epidermal\\u000a growth factor, platelet-derived growth factor-BB, and basic fibroblast growth factor) in a scaffoldless approach with costal\\u000a chondrocytes, attempting to improve biochemical and mechanical properties of engineered constructs. Samples

D. E. Johns; K. A. Athanasiou

2008-01-01

246

Light and electron microscopic immunohistochemical observations of p75 nerve growth factor receptor-immunoreactive dermal nerves in prurigo nodularis.  

PubMed

Prurigo nodularis is an inflammatory skin disease characterized by neurohyperplasia. Neurotrophins and their receptors play a critical role in nerve growth, differentiation, maturation and maintenance, including cutaneous nerve fiber growth and innervation. They may also be responsible for events related to the growth and differentiation control of keratinocytes. To explore the exact distribution of the p75 low-affinity nerve growth factor receptor (p75 NGFr) in the cutaneous nerve components, p75 NGFr immunofluorescence as well as ultrastructural immunohistochemical studies were performed on prurigo nodularis lesional skin and normal human skin samples. The immunofluorescence results revealed that nerve fibers and bundles were increased in number and size in lesional upper dermis with stronger p75 NGFr immunoreactivity than in the corresponding normal tissue. At the ultrastructural level, a lot of nerve fibers clustered together in the prurigo nodularis dermal tissue. The axons were enlarged and branched, but the axons themselves seldom showed any NGFr immunoreactivity. The Schwann cell bodies were extended and irregularly shaped, and tended to separate into many branches enveloping the axons. The Schwann cell membrane showed strong p75 NGFr immunoreactivity. The perineurium cells also revealed strong p75 NGFr immunoreactivity. The Schwann cells inside the perineurium were less p75 NGFr-immunoreactive than those outside the perineurium. The membrane of certain basal keratinocytes showed NGFr immunoreactivity as well. The present results indicate that overexpression of p75 NGFr in Schwann cells and perineurium cells could contribute to the neurohyperplasia in prurigo nodularis. PMID:10025723

Liang, Y; Marcusson, J A; Johansson, O

1999-01-01

247

Isolation and propagation of keratinocytes derived from Cashmere goat fetus.  

PubMed

The study was conducted to isolate epidermal keratinocytes from Cashmere goat fetus with the aim to develop suitable conditions for keratinocyte cultivation and propagation. The methods developed for keratinocyte culture include (i) use of a feeder-layer of mitotically inactivated fibroblasts obtained from goat and mouse fetal skin, (ii) use of a substrate such as collagen IV, or (iii) without use of any substrate. Epidermal cell removal was established by enzymatically separating keratinocytes from 12 to 16 weeks aged fetal skin tissues treated with 0.125% trypsin solution overnight at 4 degrees C. The cells were maintained in all culture conditions with serum containing medium. Keratinocyte multiplication and proliferation were comparable in different culture conditions and the improved cellular attachment and growth have been obtained in cultures on feeder layers. Colony forming keratinocytes on feeder layer were heterogeneous in their growth potential. In feeder free conditions, high cellular density was required at plating for sub-cultivation as their poor attachment in culture dishes. This study reports the comparative efficacy of different culture conditions for keratinocyte isolation and in vitro propagation originating from Cashmere goat fetus. PMID:17881027

Islam, M S; Zhou, H M

2007-09-18

248

CD44 isoforms containing exon V3 are responsible for the presentation of heparin-binding growth factor  

PubMed Central

Glycosaminoglycan-modified isoforms of CD44 have been implicated in growth factor presentation at sites of inflammation. In the present study we show that COS cell transfectants expressing CD44 isoforms containing the alternatively spliced exon V3 are modified with heparan sulfate (HS). Binding studies with three HS-binding growth factors, basic-fibroblast growth factor (b-FGF), heparin binding-epidermal growth factor (HB-EGF), and amphiregulin, showed that the HS-modified CD44 isoforms are able to bind to b-FGF and HB-EGF, but not AR. b-FGF and HB-EGF binding to HS-modified CD44 was eliminated by pretreating the protein with heparitinase or by blocking with free heparin. HS- modified CD44 immunoprecipitated from keratinocytes, which express a CD44 isoform containing V3, also bound to b-FGF. We examined whether HS- modified CD44 isoforms were expressed by activated endothelial cells where they might present HS-binding growth factors to leukocytes during an inflammatory response. PCR and antibody-binding studies showed that activated cultured endothelial cells only express the CD44H isoform which does not contain any of the variably spliced exons including V3. Immunohistological studies with antibodies directed to CD44 extracellular domains encoded by the variably spliced exons showed that vascular endothelial cells in inflamed skin tissue sections do not express CD44 spliced variants. Keratinocytes, monocytes, and dendritic cells in the same specimens were found to express variably spliced CD44. 35SO4(-2)-labeling experiments demonstrated that activated cultured endothelial cells do not express detectable levels of chondroitin sulfate or HS-modified CD44. Our results suggest that one of the functions of CD44 isoforms expressing V3 is to bind and present a subset of HS-binding proteins. Furthermore, it is probable that HS- modified CD44 is involved in the presentation of HS-binding proteins by keratinocytes in inflamed skin. However, our data suggests that CD44 is not likely to be the proteoglycan principally involved in presenting HS- binding growth factors to leukocytes on the vascular cell wall.

1995-01-01

249

p63 identifies keratinocyte stem cells  

Microsoft Academic Search

The proliferative compartment of stratified squamous epithelia consists of stem and transient amplifying (TA) keratinocytes. Some polypeptides are more abundant in putative epidermal stem cells than in TA cells, but no polypeptide confined to the stem cells has yet been identified. Here we show that the p63 transcription factor, a p53 homologue essential for regenerative proliferation in epithelial development, distinguishes

Graziella Pellegrini; Elena Dellambra; Osvaldo Golisano; Enrica Martinelli; Ivana Fantozzi; Sergio Bondanza; Diego Ponzin; Frank McKeon; Michele de Luca

2001-01-01

250

The integrin-growth factor receptor duet.  

PubMed

Cell adhesion receptors, referred to as integrins, are recognized as key regulators of cellular processes including growth and differentiation. Integrins communicate with growth factor receptors (GFRs) to control specific cellular responses to stimuli originating in the extracellular environment. In this article, we review the role of integrins as molecular switches that modulate GFR activation and specificity. We also examine the reciprocal modulation of integrin functions by GFRs and the mechanisms through which those actions are fine-tuned. PMID:17886260

Alam, Naved; Goel, Hira Lal; Zarif, Matthew J; Butterfield, Julie E; Perkins, Hillary M; Sansoucy, Brian G; Sawyer, Thomas K; Languino, Lucia R

2007-12-01

251

Serum growth factors and oncoproteins in firefighters.  

PubMed

Firefighters are potentially at increased risk for cancer and non-malignant respiratory disease due to their toxic exposures on the job. Growth factors and oncogene proteins are thought to play a role in the development of various malignancies and pulmonary fibrotic diseases. Therefore, a cohort of firefighters and matched controls have been screened for the presence of nine different growth factors and oncoproteins using an immunoblotting assay. Fourteen of the firefighters were found to be positive for beta-transforming growth factor (beta-TGF) related proteins compared to no positives in the controls (P = 0.0017). These results suggest that beta-TGF may be a possible biomarker for monitoring firefighters and other exposed workers for the potential development of cancer or non-malignant respiratory disease. PMID:1533320

Ford, J; Smith, S; Luo, J C; Friedman-Jimenez, G; Brandt-Rauf, P; Markowitz, S; Garibaldi, K; Niman, H

1992-02-01

252

Mycoplasma growth factors in bovine serum fraction.  

PubMed Central

Mycoplasma growth factors in bovine serum fraction were separated by Sephadex G150 column chromatography and density ultracentrifugation. The major growth factor of bovine serum fraction eluted from the Sephadex column in the void volume. Its growth-supporting activity was greatly enhanced by the presence of bovine serum albumin in the mycoplasma culture media. Other investigators had previously identified the major growth factor in serum as an alpha-lipoprotein. Although density ultracentrifugation revealed the presence of traces of a high-density lipoprotein in bovine serum fraction, another, less dense component, isolated by ultracentrifugation (component 3) and containing cholesterol, cholesteryl esters, free fatty acids, triglycerides, and protein, but no lipoprotein, exhibited considerably more growth-supporting activity than did the high-density lipoprotein, thus indicating that at least two mycoplasma species do not require intact serum lipoprotein for growth. Both the high-density lipoprotein and component 3 exhibited maximum activity only in the presence of bovine serum albumin. A chloroform extract containing component 3 lipids combined with bovine serum albumin to form an effective, partially defined, less complex substitute for serum in mycoplasma culture media. Images

Washburn, L R; Hughes, J H; Somerson, N L

1978-01-01

253

AP1-dependent repression of TGF?-mediated MMP9 upregulation by PPAR? agonists in keratinocytes.  

PubMed

Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors that function mainly in the regulation of glucose and lipid homeostasis. PPAR agonists have been shown to control inflammation by inhibition of distinct proinflammatory genes. Aberrant activation of the epidermal growth factor receptor and/or overexpression of its ligand, transforming growth factor-? (TGF?), are key features of both neoplastic and inflammatory hyperproliferative epithelia. Matrix metalloproteinase 9 (MMP9) belongs to the set of genes that are effectively induced by TGF? in keratinocytes. Induction of MMP9 expression is strongly linked to regenerative skin repair mechanisms, inflammatory skin diseases and tumor metastasis. We explored whether the known anti-inflammatory effects of PPAR? ligands involve inhibiting the TGF?-mediated upregulation of MMP9. The PPAR? agonists potently inhibited TGF?-induced MMP9 expression in human keratinocytes. This inhibition was observed at both the protein and mRNA levels. Transcriptional activation studies with deletion constructs of a reporter gene revealed that PPAR? agonists mediate their inhibitory effects via an AP1-binding site. Electromobility shift assay analysis indicated that MMP9 gene expression is inhibited by repressing site-dependent DNA binding and transactivation by c-fos. In conclusion, our data provide the first evidence that MMP9 expression induced by TGF? is a valid target of PPAR? ligands in keratinocytes. PMID:21496113

Meissner, Markus; Berlinski, Barbara; Doll, Monika; Hrgovic, Igor; Laubach, Vesselina; Reichenbach, Gabi; Kippenberger, Stefan; Gille, Jens; Kaufmann, Roland

2011-05-01

254

An endothelial cell-derived growth factor  

Microsoft Academic Search

Cell-free plasma-derived serum(PDS) isdeficient intheplatelet-derived growth factorand willnotsupportthegrowthof3T3 cells, fibroblasts, orsmoothmuscle cells .However,when PDS-containingmedium ispreincubatedwithendothelial cells, themedium becomesmodifiedsothatitwillsupportgrowth.The activity producedby theendothelial cellsresults from a polypeptideof10,000to30,000 daltonswhich hasseveralfeaturesthatdifferfrom thoseoftheplatelet-derived growthfactor, includingheatinstability and lackofadsorption toCM Sephadex. Growth ofnontransformed cellstrainsin culture requires one or more exogenous growth factors. The availabilityofthese polypeptides appears to determine the extent ofgrowth, and account, at leastin part, for

CORINNE GAJDUSEK; PAUL DICORLETO; RUSSELL ROSS; STEPHEN M. SCHWARTZ

1980-01-01

255

Biology of vascular endothelial growth factors.  

PubMed

Angiogenesis is the process by which new blood vessels are formed from existing vessels. The vascular endothelial growth factors (VEGFs) are considered as key molecules in the process of angiogenesis. The VEGF family currently includes VEGF-A, -B, -C, -D, -E, -F and placenta growth factor (PlGF), that bind in a distinct pattern to three structurally related receptor tyrosine kinases, denoted VEGF receptor-1, -2, and -3. VEGF-C and VEGF-D also play a crucial role in the process of lymphangiogenesis. Here, we review the biology of VEGFs and evaluate their role in pathological angiogenesis and lymphangiogenesis. PMID:16631753

Roy, Himadri; Bhardwaj, Shalini; Ylä-Herttuala, Seppo

2006-04-17

256

Growth factor parametrization in curved space  

SciTech Connect

The growth rate of matter perturbation and the expansion rate of the Universe can be used to distinguish modified gravity and dark energy models in explaining cosmic acceleration. We explore here the inclusion of spatial curvature into the growth factor. We expand previous results using the approximation {omega}{sub m}{sup {gamma}} and then suggest a new form, f{sub a}={omega}{sub m}{sup {gamma}}+({gamma}-4/7){omega}{sub k}, as an approximation for the growth factor when the curvature {omega}{sub k} is not negligible, and where the growth index {gamma} is usually model dependent. The expression recovers the standard results for the curved and flat {lambda}CDM and Dvali-Gabadadze-Porrati models. Using the best fit values of {omega}{sub m0} and {omega}{sub k0} to the expansion/distance measurements from Type Ia SNe, baryon acoustic oscillation, WMAP5, and H(z) data, we fit the growth index parameter to current growth factor data and obtain {gamma}{sub {lambda}}({omega}{sub k}{ne}0)=0.65{sub -0.15}{sup +0.17} and {gamma}{sub DGP}({omega}{sub k}{ne}0)=0.53{sub -0.12}{sup +0.14}. For the {lambda}CDM model, the 1-{sigma} observational bounds are found consistent with theoretical value, unlike the case for the Dvali-Gabadadze-Porrati model. We also find that the current data we used is not enough to put significant constraints when the 3 parameters in f{sub a} are fit simultaneously. Importantly, we find that, in the presence of curvature, the analytical expression proposed for f{sub a} provides a better fit to the growth factor than other forms and should be useful for future high precision missions and studies.

Gong Yungui; Ishak, Mustapha; Wang Anzhong [College of Mathematics and Physics, Chongqing University of Posts and Telecommunications, Chongqing 400065 (China) and Kavli Institute for Theoretical Physics China, CAS, Beijing 100190 (China); Department of Physics, University of Texas at Dallas, Richardson, Texas 75083 (United States); CASPER, Physics Department, Baylor University, Waco, Texas 76798 (United States)

2009-07-15

257

Vascular growth factors in cerebral ischemia  

Microsoft Academic Search

During the past decade, there has been a surge of interest in growth factors (GFs) that act selectively on vascular endothelium\\u000a and perivascular cells. Studies employing mutant mice or the administration of recombinant proteins have suggested that these\\u000a factors not only mediate the proliferation of endothelial cells, but also regulate vascular differentiation, regression, and\\u000a permeability. During and after cerebral ischemia,

Susan D. Croll; Stanley J. Wiegand

2001-01-01

258

Vascular endothelial growth factor in esophageal cancer.  

PubMed

Vascular endothelial growth factor (VEGF) plays a crucial role in angiogenesis of many solid malignancies. The influence of angiogenesis and VEGF expression on progression and recurrence of esophageal cancer has been investigated over the last years. This article reviews the prognostic significance of VEGF expression, microvessel density (MVD), and lymphangiogenic factors in squamous cell carcinoma (SCC), Barrett's dysplasia, and adenocarcinoma (AC) of the esophagus, their predictive value for treatment response to chemo-radiotherapy and new anti-angiogenic treatment strategies. PMID:15282704

Kleespies, Axel; Guba, Markus; Jauch, Karl-Walter; Bruns, Christiane J

2004-08-01

259

Effect of laser phototherapy on the release of fibroblast growth factors by human gingival fibroblasts.  

PubMed

The effects of laser phototherapy on the release of growth factors by human gingival fibroblasts were studied in vitro. Cells from a primary culture were irradiated twice (6 h interval), with continuous diode laser [gallium-aluminum-arsenium (GaAlAs), 780 nm, or indium-gallium-aluminum-phosphide (InGaAlP),_660 nm] in punctual and contact mode, 40 mW, spot size 0.042 cm(2), 3 J/cm(2) and 5 J/cm(2) (3 s and 5 s, respectively). Positive [10% fetal bovine serum (FBS)] and negative (1%FBS) controls were not irradiated. Production of keratinocyte growth factor (KGF) and basic fibroblast growth factor (bFGF) was quantified by enzyme-linked immunosorbent assay (ELISA). The data were statistically compared by analysis of variance (ANOVA) followed by Tukey's test (P

Damante, Carla Andreotti; De Micheli, Giorgio; Miyagi, Sueli Patrícia Harumi; Feist, Ilíria Salomão; Marques, Márcia Martins

2008-07-04

260

Growth factors and corneal epithelial wound healing  

PubMed Central

In this article, we briefly review recent findings in the effects of growth factors including the EGF family, KGF, HGF, IGF, insulin, and TGF-? on corneal epithelial wound healing. We discuss the essential role of EGFR in inter-receptor cross-talk in response to wounding in corneal epithelium and bring forward a concept of “alarmins” to the field of wound healing research.

Yu, Fu-Shin X.; Yin, Jia; Xu, Keping; Huang, Jenny

2010-01-01

261

Growth factors in skeletal muscle regeneration  

Microsoft Academic Search

Adult skeletal muscles are able to regenerate after injury. This process is due to the activation of quiescent muscle precursor cells, also called satellite cells, which proliferate and differentiate to form new myotubes. In this regeneration process, several growth factors which come from the muscle and\\/or from the motor nerve and inflammatory cells have been shown to play key roles.

Irene Husmann; Laurent Soulet; Jean Gautron; Isabelle Martelly; Denis Barritault

1996-01-01

262

Growth Factor Antagonism in Breast Cancer Chemotherapy.  

National Technical Information Service (NTIS)

The primary focus of this work is the identification of molecules that block the interaction of growth factors with their receptor tyrosine kinases (RTKs). We plan to design, synthesize and evaluate a novel series of synthetic agents that bind to the surf...

A. D. Hamilton

2001-01-01

263

Growth Factor Antagonism in Breast Cancer Chemotherapy.  

National Technical Information Service (NTIS)

The primary focus of this work is the identification of molecules that block the interaction of growth factors with their receptor tyrosine kinases (RTKs) . We have designed, synthesized and evaluated a novel series of synthetic agents that bind to the su...

A. D. Hamilton

2002-01-01

264

Transforming Growth Factor 1 to the Bone  

Microsoft Academic Search

TGF-1 is a ubiquitous growth factor that is implicated in the control of proliferation, migration, differentiation, and sur- vival of many different cell types. It influences such diverse processes as embryogenesis, angiogenesis, inflammation, and wound healing. In skeletal tissue, TGF-1 plays a major role indevelopmentandmaintenance,affectingbothcartilageand bone metabolism, the latter being the subject of this review. Because it affects both cells

Katrien Janssens; Sophie Janssens; Wim Van Hul; Leids Universitair

2005-01-01

265

Insulin-like growth factors and neoplasia  

Microsoft Academic Search

The insulin-like growth factor 1 (IGF1) signalling pathway has important roles in regulating cellular proliferation and apoptosis. Converging results from epidemiological research and in vivo carcinogenesis models indicate that high levels of circulating IGF1 are associated with increased risk of several common cancers. Ongoing research seeks to clarify the mechanisms underlying these observations and to determine the extent to which

Eva S. Schernhammer; Susan E. Hankinson; Michael N. Pollak

2004-01-01

266

Organotypic Modeling of Human Keratinocyte Response 1 to Peroxisome Proliferators  

PubMed Central

Peroxisome proliferators (PPs) are a diverse chemical group including hypolipidemic drugs and some fatty acids. Their stimulation of PP activated receptors (PPAR) and subsequent control of gene expression regulates metabolism and differentiation in many cells. PPs have multiple opportunities to target human epidermal keratinocytes because of delivery through dietary, clinical and/or topical exposure routes. PPAR knockout mice and PP treatment of mouse skin or human keratinocytes in monolayer culture have established some effects for PPs in cutaneous differentiation. However, incomplete epidermal maturation characteristic of monolayer keratinocytes and rodent-specific effects may limit our full understanding of human keratinocyte responses to PPs. To address these issues, we investigated PP influence on primary human keratinocytes in organotypic cultures that recapitulate biochemical markers of epidermis. We found the PPAR? agonists clofibrate, docasohexaenoic acid, and WY-14,643 produced mild to moderate keratinocyte hyperplasia, increased stratification, particularly of granular and cornified layers, and enhanced levels of the differentiation markers filaggrin, ABCA12, and phosphorylated HSP27. Several PP effects generated in the organotypic system however were distinct from those previously reported for rodent skin and human keratinocyte monolayer cultures suggesting the species and growth context of target cells can impact exposure outcomes. Given the utility of organotypic cultures to modeling the epidermis, studies in this system may bridge the gap between the rodent assays and clinical studies of human epidermal responses to PPs.

Zhang, Carmen; Gurevich, Igor; Aneskievich, Brian J.

2013-01-01

267

Growth factors in lung development and disease: friends or foe?  

Microsoft Academic Search

Growth factors mediate tissue interactions and regulate a variety of cellular functions that are critical for normal lung development and homeostasis. Besides their involvement in lung pattern formation, growth and cell differentiation during organogenesis, these factors have been also implicated in modulating injury-repair responses of the adult lung. Altered expression of growth factors, such as transforming growth factor ?1, vascular

Tushar J Desai; Wellington V Cardoso

2002-01-01

268

Growth factors in ulcer healing: Lessons from recent studies  

Microsoft Academic Search

Growth factors such as epidermal growth factor (EGF), basic fibroblast growth factor (bFGF), platelet-derived growth factor (PDGF) and more recently vascular endothelial growth factor (VEGF) have been used extensively to heal experimental gastric, duodenal and colonic ulcers in animal models. Encouraging results have been reported in clinical trials with EGF and bFGF. Since our laboratory has been involved with the

Sandor Szabo; Áron Vincze

2000-01-01

269

Senataxin modulates neurite growth through fibroblast growth factor 8 signalling.  

PubMed

Senataxin is encoded by the SETX gene and is mainly involved in two different neurodegenerative diseases, the dominant juvenile form of amyotrophic lateral sclerosis type 4 and a recessive form of ataxia with oculomotor apraxia type 2. Based on protein homology, senataxin is predicted to be a putative DNA/RNA helicase, while senataxin interactors from patients' lymphoblast cell lines suggest a possible involvement of the protein in different aspects of RNA metabolism. Except for an increased sensitivity to oxidative DNA damaging agents shown by some ataxia with neuropathy patients' cell lines, no data are available about possible functional consequences of dominant SETX mutations and no studies address the function of senataxin in neurons. To start elucidating the physiological role of senataxin in neurons and how disease-causing mutations in this protein lead to neurodegeneration, we analysed the effect of senataxin on neuronal differentiation in primary hippocampal neurons and retinoic acid-treated P19 cells by modulating the expression levels of wild-type senataxin and three different dominant mutant forms of the protein. Wild-type senataxin overexpression was required and sufficient to trigger neuritogenesis and protect cells from apoptosis during differentiation. These actions were reversed by silencing of senataxin. In contrast, overexpression of the dominant mutant forms did not affect the regular differentiation process in primary hippocampal neurons. Analysis of the cellular pathways leading to neuritogenesis and cytoprotection revealed a role of senataxin in modulating the expression levels and signalling activity of fibroblast growth factor 8. Silencing of senataxin reduced, while overexpression enhanced, fibroblast growth factor 8 expression levels and the phosphorylation of related target kinases and effector proteins. The effects of senataxin overexpression were prevented when fibroblast growth factor 8 signalling was inhibited, while exogenous fibroblast growth factor 8 reversed the effects of senataxin silencing. Overall, these results reveal a key role of senataxin in neuronal differentiation through the fibroblast growth factor 8 signalling and provide initial molecular bases to explain the neurodegeneration associated with loss-of-function mutations in senataxin found in recessive ataxia. The lack of effect on neuritogenesis observed with the overexpression of the dominant mutant forms of senataxin apparently excludes a dominant negative effect of these mutants while favouring haploinsufficiency as the pathogenic mechanism implicated in the amyotrophic lateral sclerosis 4-related degenerative condition. Alternatively, a different protein function, other than the one involved in neuritogenesis, may be implicated in these dominant degenerative processes. PMID:21576111

Vantaggiato, Chiara; Bondioni, Sara; Airoldi, Giovanni; Bozzato, Andrea; Borsani, Giuseppe; Rugarli, Elena I; Bresolin, Nereo; Clementi, Emilio; Bassi, Maria Teresa

2011-05-15

270

Regulation of fibroblast gene expression by keratinocytes in organotypic skin culture provides possible mechanisms for the antifibrotic effect of reepithelialization.  

PubMed

To investigate the mechanisms behind the antifibrotic effect associated with epidermal regeneration, the expression of 12 fibroblast genes important for the modulation of the extracellular matrix (ECM), as well as ?-smooth muscle actin, was studied in a keratinocyte-fibroblast organotypic skin culture model. The study was performed over time during epidermal generation and in the presence or absence of the profibrotic factor transforming growth factor-?. the Presence of epidermal differentiation markers in the model was essentially coherent with that of native skin. Fibroblast gene expression was analyzed with real-time polymerase chain reaction after removal of the epidermal layer. After 2 days of air-exposed culture, 11 out of the 13 genes studied were significantly regulated by keratinocytes in the absence or presence of transforming growth factor-?. The regulation of connective tissue growth factor, collagen I and III, fibronectin, plasmin system regulators, matrix metalloproteinases and their inhibitors as well as ?-smooth muscle actin was consistent with a suppression of ECM formation or contraction. Overall, the results support a view that keratinocytes regulate fibroblasts to act catabolically on the ECM in epithelialization processes. This provides possible mechanisms for the clinical observations that reepithelialization and epidermal wound coverage counteract excessive scar formation. PMID:20731800

Koskela, Anita; Engström, Kristina; Hakelius, Malin; Nowinski, Daniel; Ivarsson, Mikael

2010-08-19

271

Altered (/sup 125/I)epidermal growth factor binding and receptor distribution in psoriasis  

SciTech Connect

Stimulation of growth and differentiation of human epidermis by epidermal growth factor (EGF) is mediated by its binding to specific receptors. Whether EGF receptors primarily mediate cell division or differentiation in hyperproliferative disease such as psoriasis vulgaris is unclear. To study the pathogenesis of psoriasis, 4-mm2 punch biopsy specimens of normal, uninvolved, and involved psoriatic skin were assayed for EGF receptors by autoradiographic, immunohistochemical, and biochemical methods. Using autoradiographic and immunohistochemical methods, basal keratinocytes were found to contain the greatest number of EGF binding sites and immunoreactive receptors as compared to the upper layers of the epidermis in both normal epidermis and psoriatic skin. No EGF receptor differences between normal and psoriatic epidermis were observed in this layer. In the upper layers of the epidermis, a 2-fold increase in EGF binding capacity was observed in psoriatic skin as compared with normal thin or thick skin. Biochemical methods indicated that (/sup 125/I)EGF binding was increased in psoriatic epidermis as compared with similar thickness normal epidermis when measured on a protein basis. Epidermal growth factor was shown to increase phosphorylation of the EGF receptor in skin. EGF receptors retained in the nonmitotic stratum spinosum and parakeratotic stratum corneum may reflect the incomplete, abnormal differentiation that occurs in active psoriatic lesions. Alternatively, retained EGF receptors may play a direct role in inhibiting cellular differentiation in the suprabasal layers.

Nanney, L.B.; Stoscheck, C.M.; Magid, M.; King, L.E. Jr.

1986-03-01

272

Identification of a cell surface protein with a role in stimulating human keratinocyte proliferation, expressed during development and carcinogenesis.  

PubMed

In an attempt to define cell surface molecules with an important role in the development of squamous cell carcinomas (SCCs), we generated monoclonal antibodies (MoAbs) to a human keratinocyte cell line (FEP18-11-T1) capable of giving rise to SCCs in nude mice. MoAb 10G7 was selected for further study because it bound to a cell surface component preferentially expressed by this cell line as compared with normal human foreskin keratinocytes. This MoAb recognizes a cell surface protein (10G7 antigen) that is not detectable on normal keratinocytes in the foreskin in vivo, but whose expression is induced when the keratinocytes are dissociated from this tissue and placed in culture. Interestingly, the 10G7 antigen is downregulated upon keratinocyte differentiation in vitro. Consistent with its expression in hyper-proliferative epithelia in vitro, 10G7 antigen exhibited a classic oncofetal pattern of expression in vivo. Thus, although no reactivity was obtained with MoAb 10G7 in the epithelia of normal foreskin or cervical tissue, strong reactivity was detected in epithelia from genital lesions ranging from benign warts to invasive SCCs. Epidermis from developing fetal tissue also exhibited strong reactivity with MoAb 10G7. We have been able to demonstrate that this MoAb is capable of stimulating FEP18-11-T1 keratinocyte proliferation in vitro in a concentration-dependent manner in the absence of growth factors, suggesting that the 10G7 antigen may play an important role in regulating cellular proliferation during development and in carcinogenesis in epithelial tissues. PMID:9242507

Kaur, P; Paton, S; Furze, J; Wrin, J; Olsen, S; Danks, J; Scurry, J

1997-08-01

273

Calcineurin inhibitors reduce nuclear localization of transcription factor NFAT in UV-irradiated keratinocytes and reduce DNA repair.  

PubMed

Calcineurin inhibitors are drugs used to suppress the immune system by blocking the nuclear localization of the NFAT transcription factor. Systemic use of these drugs is essential to organ transplantation, but comes at the cost of elevated rates of skin cancer. They have been used topically in atopic dermatitis and other skin diseases on the assumption that they avoid the cancer risk by localized use. The results here show that in skin cells and artificial models of human skin, calcineurin inhibitors block UV-induced nuclear localization of NFAT, and significantly reduce repair of cyclobutane pyrimidine dimers induced in DNA. In addition they inhibit apoptosis of UV-irradiated cells. The effect of blocking nuclear localization of NFAT and inhibiting DNA repair should be considered in judging the risk of topical use of calcineurin inhibitors. PMID:16927198

Canning, Matthew T; Nay, Stephanie L; Peña, Arely V; Yarosh, Daniel B

2006-08-23

274

FGF-P improves barrier function and proliferation in human keratinocytes after radiation  

PubMed Central

Purpose Epidermal keratinocytes, which can be severely damaged after ionizing radiation (IR), are rapid turnover cells that function as a barrier protecting the host from pathogenic invasion and fluid loss. We tested fibroblast growth factor-peptide (FGF-P), a small peptide derived from the receptor-binding domain of FGF-2, as a potential mitigator of radiation effects via proliferation and the barrier function of keratinocytes. Methods and Materials Keratinocytes isolated from neonatal foreskin were grown on transwells. After 0, 5, or 10-Gy, the cells were treated with a vehicle or FGF-P. The permeability of IR cells was assessed through transepithelial electrical resistance (TEER) and a paracellular tracer flux of fluorescein isothiocyanate-conjugated bovine serum albumin (FITC-BSA) with Ussing chambers. The cell proliferation was measured with yellow tetrazolium salt (MTT) and tritiated thymidine (3H-TdR) assays. The phosphorylation of extracellular signal-regulated kinases (ERK) was measured in an enzyme-linked immunosorbent (ELISA)-like assay, and the proteins related to tight junctions (TJ) and adherens junctions (AJ) were examined with Western blotting. We used a mouse model to assess the ability of FGF-P to promote the healing of skin ?-burns created with a strontium applicator. Results 1) FGF-P reduced the permeability of irradiated keratinocytes, as evidenced by increased TEER and decreased diffusion of FITC-BSA both associated with the regulation of different proteins and levels of TJ and AJ; 2) FGF-P enhanced the proliferation of irradiated keratinocytes, as evidenced by increased MTT activity and 3H-TdR incorporation, which was associated with activation of the ERK pathway; and 3) FGF-P promoted the healing of skin ?-burns. Conclusions FGF-P enhances the barrier function, including up-regulation of TJ proteins, increases proliferation of human keratinocytes, and accelerates the healing of skin ?-burns. FGF-P is a promising mitigator that improves the proliferation and barrier function of keratinocytes after IR.

Zhang, Kunzhong; Tian, Yeping; Yin, Liangjie; Zhang, Mei; Beck, Lisa A.; Zhang, Bingrong; Okunieff, Paul; Zhang, Lurong; Vidyasagar, Sadasivan

2011-01-01

275

Binding of epidermal growth factor and insulin-like growth factor I in human myometrium and leiomyomata  

SciTech Connect

Samples of uterine myometrium and leiomyoma from 11 women were analyzed for the presence of epidermal growth factor receptors and insulin-like growth factor I receptors. In addition, the content of soluble insulin-like growth factor binding protein (IGF-BP/PP12) was measured in the tissue cytosols. Cell membrane preparations of myoma tissue bound significantly more insulin-like growth factor I than did those of adjacent normal myometrium, whereas myoma tissue bound less epidermal growth factor than did the normal myometrium. The differences in both insulin-like growth factor I and epidermal growth factor binding were due to changes in receptor concentration rather than to alterations in receptor affinity. Neither myoma nor myometrial tissue contained detectable levels of insulin-like growth factor binding protein. The changes in epidermal growth factor and insulin-like growth factor I binding to the myometrium may play a role in the pathogenesis of uterine leiomyomata.

Tommola, P.; Pekonen, F.; Rutanen, E.M. (Minerva Institute for Medical Research, Kauniainen (Finland))

1989-10-01

276

Regulation of cell growth and motility by hepatocyte growth factor and receptor expression in various cell species.  

PubMed

Hepatocyte growth factor (HGF), a humoral mediator for regeneration of liver and kidney, possesses multiple biological activities. To investigate target cell specificity and to examine whether multiple actions of HGF are related to properties of the HGF receptor on target cells, we examined the effects of HGF on cell growth and motility and analyzed the HGF receptor in various species of cells. HGF stimulated growth and DNA synthesis of PAM212 (naturally immortalized mouse keratinocytes), Mv1Lu (mink lung epithelia), and A431 (human epidermoid carcinoma) cells, as well as mature hepatocytes, but inhibited those of IM-9 (human B-lymphoblasts). Conversely, HGF had a marked stimulatory effect on cell motility of MDCK (Mardin-Darby canine kidney epithelia) cells, but not on their growth. Also, HGF enhanced the motility of various species of cells, including A431, PAM212, HepG2 (human hepatoma), KB (human epidermoid carcinoma), and J-111 (human monocytes) cells. Scatchard analysis of 125I-HGF binding to hepatocytes indicated that the cells expressed both high- and low-affinity binding sites for HGF with Kd values of 23 and 260 pM, respectively. High-affinity HGF receptor with Kd values of 20-25 pM was detected at 40-720 sites/cell in MDCK, A431, PAM212, Lu99, and IM-9 cells, but not in fibroblasts and hematopoietic cells. In contrast, low-affinity binding sites were detected in all cell lines examined, even in those not responsive to HGF. Northern blots revealed that cells possessing a high-affinity HGF receptor expressed c-MET/HGF receptor mRNA. Therefore, HGF probably regulates both cell growth and motility of various types of epithelial cells and some types of mesenchymal cells. The multiple biological activities of HGF may be exerted through a high-affinity HGF receptor linked to multiple distinct intracellular signaling pathways. PMID:1327854

Tajima, H; Matsumoto, K; Nakamura, T

1992-10-01

277

Stimulatory Actions of Insulin-Like Growth FactorI and Transforming Growth Factor  on Intestinal Neurotensin and Peptide YY  

Microsoft Academic Search

Proliferation of the gastrointestinal mucosa is stimulated by the growth factors, insulin-like growth factor-I (IGF-I) and transforming growth factor-a (TGF-a), or the closely related epidermal growth factor (EGF), as well as the gastrointestinal hormones, gastrin, neu- rotensin (NT), and peptide YY (PYY). The stimulatory actions of these growth factors or gastrointestinal hormones on the gastrointestinal mucosa may be direct or

HEUNG-MAN LEE; VIDYAVATHI UDUPI; ELLA W. ENGLANDER; SRINIVASAN RAJARAMAN; ROBERT J. COFFEY; GEORGE H. GREELEY

1999-01-01

278

Growth factors for bone growth and repair: IGF, TGF? and BMP  

Microsoft Academic Search

Current research is reviewed regarding the actions of three growth factor systems on bone formation: insulin-like growth factors (IGFs), transforming growth factor-?s (TGF?s), and bone morphogenetic proteins (BMPs). Each growth factor family consists of multiple related growth factor genes. TGF?s and BMPs 2–7 are subfamilies of a larger TGF? superfamily. IGFs, TGF?s and BMPs are produced by osteoblasts and other

Thomas A. Linkhart; Subburaman Mohan; David J. Baylink

1996-01-01

279

Growth factor signalling in endocrine and anti-growth factor resistant breast cancer  

Microsoft Academic Search

Growth factors provide powerful mitogenic and survival signals to breast cancer cells and it is therefore not surprising that\\u000a they are able to subvert inhibitory responses to anti-hormonal drugs. In this review we discuss several mechanisms by which\\u000a this may be achieved and expand our observations to encompass recently emerging anti-growth factor treatments. The information\\u000a presented is underpinned by inhibitor

R. I. Nicholson; I. R. Hutcheson; H. E. Jones; S. E. Hiscox; M. Giles; K. M. Taylor; J. M. W. Gee

2007-01-01

280

Epidermal growth factor receptor signaling in tissue  

SciTech Connect

Abstract: A peptide purified from the salivary gland of a mouse was shown few years ago to accelerate incisor eruption and eyelid opening in newborn mice, and was named epidermal growth factor (EGF). The members of this family of peptide growth factors had been identified in numerous physiological and pathological contexts. EGF binds to a cell surface EGF receptor, which induces a biochemical modification (phosphorylation) of the receptor's cytoplasmic tail. There is a growing consensus in the research community that, in addition to cellular and molecular studies, the dynamics of the EGFR network and its operation must be examined in tissues. A key challenge is to integrate the existing molecular and cellular information into a system-level description of the EGFR network at the tissue and organism level. In this paper, the two examples of EGFR signaling in tissues are described, and the recent efforts to model EGFR autocrine loops, which is a predominant mode of EGFR activation in vivo, are summarized.

Shvartsman, Stanislav; Wiley, H. S.; Lauffenburger, Douglas A.

2004-08-01

281

Transforming growth factor-? and smooth muscle differentiation  

PubMed Central

Transforming growth factor (TGF)-? family members are multifunctional cytokines regulating diverse cellular functions such as growth, adhesion, migration, apoptosis, and differentiation. TGF-?s elicit their effects via specific type?I?and type II serine/threonine kinase receptors and intracellular Smad transcription factors. Knockout mouse models for the different components of the TGF-? signaling pathway have revealed their critical roles in smooth muscle cell (SMC) differentiation. Genetic studies in humans have linked mutations in these signaling components to specific cardiovascular disorders such as aorta aneurysm and congenital heart diseases due to SMC defects. In this review, the current understanding of TGF-? function in SMC differentiation is highlighted, and the role of TGF-? signaling in SMC-related diseases is discussed.

Guo, Xia; Chen, Shi-You

2012-01-01

282

Epidermal growth factor receptor in glioblastoma.  

PubMed

We compiled the current state of knowledge about the epidermal growth factor receptor (EGFR) in glioblastoma. Glioblastoma is one of the most common primary brain tumours and has an unfavourable prognosis despite aggressive treatment. These factors stimulate new research trials and a recent area of interest of neuro-oncologists is EGFR. This molecule is frequently altered in glioblastoma and constitutes the potential target for therapy. We decided to review the literature on biological structure of that molecule, its biological activity and the role in GBL with potential targeting it in the future neuro-oncological practice. PMID:16245205

Zawrocki, Antoni; Biernat, Wojciech

2005-01-01

283

Transcriptional Regulation of the Elafin Gene in Human Keratinocytes  

Microsoft Academic Search

Elafin (also known as skin-derived anti-leukoproteinase\\/trappin-2) is an epithelial host-defense protein that is absent in normal skin but highly induced in keratinocytes of inflamed skin (e.g., psoriasis), in epidermal skin tumors, and after wounding. Previously, it was shown that in cultured keratinocytes, elafin expression is induced by serum or tumor necrosis factor–?, and that expression is suppressed by retinoids, dithranol,

Arno Pol; Rolph Pfundt; Patrick Zeeuwen; Henri Molhuizen; Joost Schalkwijk

2003-01-01

284

Transforming Growth Factor-? in Cancer Therapy  

Microsoft Academic Search

Several transforming growth factor-? (TGF-?) signaling pathway proteins undergo proteasomal degradation. Controlled proteasomal\\u000a degradation provides a means for the cell to time and fine-tune the duration of both positive and negative physiological signals.\\u000a Importantly, this physiological control appears to be aberrant in for example tumor cells carrying mutations of the Smad signaling\\u000a molecules. We summarize here the recent striking observations

Arja Band; Marikki Laiho

285

Cellular signaling by fibroblast growth factor receptors.  

PubMed

The 22 members of the fibroblast growth factor (FGF) family of growth factors mediate their cellular responses by binding to and activating the different isoforms encoded by the four receptor tyrosine kinases (RTKs) designated FGFR1, FGFR2, FGFR3 and FGFR4. Unlike other growth factors, FGFs act in concert with heparin or heparan sulfate proteoglycan (HSPG) to activate FGFRs and to induce the pleiotropic responses that lead to the variety of cellular responses induced by this large family of growth factors. A variety of human skeletal dysplasias have been linked to specific point mutations in FGFR1, FGFR2 and FGFR3 leading to severe impairment in cranial, digital and skeletal development. Gain of function mutations in FGFRs were also identified in a variety of human cancers such as myeloproliferative syndromes, lymphomas, prostate and breast cancers as well as other malignant diseases. The binding of FGF and HSPG to the extracellular ligand domain of FGFR induces receptor dimerization, activation and autophosphorylation of multiple tyrosine residues in the cytoplasmic domain of the receptor molecule. A variety of signaling proteins are phosphorylated in response to FGF stimulation including Shc, phospholipase-Cgamma, STAT1, Gab1 and FRS2alpha leading to stimulation of intracellular signaling pathways that control cell proliferation, cell differentiation, cell migration, cell survival and cell shape. The docking proteins FRS2alpha and FRS2beta are major mediators of the Ras/MAPK and PI-3 kinase/Akt signaling pathways as well as negative feedback mechanisms that fine-tune the signal that is initiated at the cell surface following FGFR stimulation. PMID:15863030

Eswarakumar, V P; Lax, I; Schlessinger, J

2005-02-01

286

Epidermal Growth Factor Receptor-Targeted Therapies  

Microsoft Academic Search

\\u000a The epidermal growth factor receptor (EGFR) has been implicated in the progression and maintenance of various solid tumors.\\u000a Efforts in understanding EGFR biology and related signaling cascades have lead to the development of anti-EGFR agents. The\\u000a two main approaches of inhibition that have been ­studied most extensively are monoclonal antibodies and tyrosine kinase inhibitors.\\u000a Despite clear evidence of antitumor activity

Sun M. Ahn; Seungwon Kim; Jennifer R. Grandis

287

Vascular Endothelial Growth Factor Overexpression Increases Vascularization by Murine But Not Human Endothelial Cells in Cultured Skin Substitutes Grafted to Athymic Mice  

PubMed Central

Cultured skin substitutes (CSS) consisting of fibroblasts, keratinocytes, and biopolymers are an adjunctive treatment for large burns. Because CSS lack a vascular plexus, they vascularize more slowly than split-thickness autografts. Previously, CSS were prepared with dermal microvascular endothelial cells (ECs), which formed vascular analogs at a low frequency but did not contribute to increased vascularization after grafting. The present study addressed whether keratinocytes genetically modified to overexpress vascular endothelial growth factor (VEGF), an endothelial cell mitogen, could improve the persistence and organization of ECs in CSS. CSS were prepared with control or VEGF-modified keratinocytes, with (CSS + ECs) or without added ECs, and were grafted to full-thickness wounds in athymic mice. Elevated VEGF expression was detected in VEGF-modified CSS and CSS + ECs compared with controls, but no significant difference in EC density in vitro was observed. After grafting, VEGF-modified CSS and CSS + ECs showed enhanced vascularization, and organization of human ECs into multicellular structures in CSS + ECs was observed. However, VEGF overexpression did not significantly enhance the proliferation of human ECs, suggesting that other factors may be required. Improved persistence and organization of human ECs in vitro will likely be required for their participation in vascularization of CSS + ECs after grafting.

Supp, Dorothy M.; Karpinski, Andrea C.; Boyce, Steven T.

2007-01-01

288

The suppression of fibroblast growth factor 2/fibroblast growth factor 4-dependent tumour angiogenesis and growth by the anti-growth factor activity of dextran derivative (CMDB7).  

PubMed Central

Our previous studies showed that carboxymethyl benzylamide dextran (CMDB7) blocks basic fibroblast growth factor (FGF-2)-dependent cell proliferation of a human breast epithelial line (HBL100), suggesting its potential role as a potent antiangiogenic substance. The derived cell line (HH9), which was transformed with the hst/FGF4 gene, has been shown to be highly proliferative in vitro and to induce angiogenic tumours in nude mice. We show here that CMDB7 inhibits the mitogenic activities of the conditioned media from HBL 100 and HH9 cells in a dose-dependent manner. When HH9 cells were injected s.c. into nude mice, CMDB7 treatment (300 mg kg(-1) week(-1)) suppressed the tumour take and the tumour growth by about 50% and 80% respectively. Immunohistochemical analysis showed a highly significant decrease, by more than threefold, in the endothelial density of viable tumour regions, together with a significant increase in the necrosis area. This antiangiogenic activity of CMDB7 was further demonstrated by direct inhibition of calf pulmonary artery (CPAE) and human umbilical vein (HUVEC) endothelial cell proliferation and migration in vitro. In addition, we showed that CMDB7 inhibits specifically the mitogenic effects of the growth factors that bind to heparin such as FGF-2, FGF-4, platelet-derived growth factor (PDGF-BB) and transforming growth factor (TGF-beta1), but not those of epidermal growth factor (EGF) and insulin-like growth factor (IGF-1). These results demonstrate that CMDB7 inhibits FGF-2/FGF-4-dependent tumour growth and angiogenesis, most likely by disrupting the autocrine and paracrine effects of growth factors released from the tumour cells. Images Figure 4

Bagheri-Yarmand, R.; Kourbali, Y.; Mabilat, C.; Morere, J. F.; Martin, A.; Lu, H.; Soria, C.; Jozefonvicz, J.; Crepin, M.

1998-01-01

289

Establishment of spontaneously immortalized keratinocyte lines from wild-type and mutant mice.  

PubMed

A considerable number of transgenic or knockout mice in which epidermal keratinocytes have been targeted die shortly after birth due to barrier defects. In this case, recovery and cultivation of keratinocytes from these animals provide an opportunity for in vitro studies. Working with isolated keratinocytes is also interesting for certain experiments which cannot be performed in live animals. Primary human keratinocytes can be kept in culture for a variable number of passages and then senescence. Immortalization can be achieved by transduction with constructs encoding viral genes. Murine keratinocytes can be kept in culture as primary cells. Naturally the numbers of cells obtained by direct isolation from mouse epidermis is restricted and sometimes not sufficient for certain biochemical analyses. To overcome this restriction some permanent murine keratinocyte lines have been generated by transfection with SV40T or HPV E6E7 genes. This is, however, not suitable if established or hypothetical biochemical links exist between these genes and the pathways or processes to be analysed in the respective experiment. We describe an easy and reproducible method of establishing permanent keratinocyte lines from spontaneously immortalized primary murine keratinocytes. This method employs co-cultivation of keratinocytes with 3T3-J2 fibroblast feeder cells for several passages during which immortalization occurs. The resulting keratinocyte lines do not only grow infinitely but, in many cases, individual lines from the same genetic background also exhibit similar growth characteristics, hence they are especially valuable for comparative studies. PMID:19907996

Reichelt, Julia; Haase, Ingo

2010-01-01

290

Growth factor parametrization and modified gravity  

SciTech Connect

The growth rate of matter perturbation and the expansion rate of the Universe can be used to distinguish modified gravity and dark energy models in explaining the cosmic acceleration. The growth rate is parametrized by the growth index {gamma}. We discuss the dependence of {gamma} on the matter energy density {omega} and its current value {omega}{sub 0} for a more accurate approximation of the growth factor. The observational data, including the data of the growth rate, are used to fit different models. The data strongly disfavor the Dvali-Gabadadze-Porrati model. For the dark energy model with a constant equation of state, we find that {omega}{sub 0}=0.27{+-}0.02 and w=-0.97{+-}0.09. For the {lambda}CDM model, we find that {gamma}=0.64{sub -0.15}{sup +0.17}. For the Dvali-Gabadadze-Porrati model, we find that {gamma}=0.55{sub -0.13}{sup +0.14}.

Gong Yungui [College of Mathematics and Physics, Chongqing University of Posts and Telecommunications, Chongqing 400065 (China)

2008-12-15

291

Modelling the interaction of keratinocytes and fibroblasts during normal and abnormal wound healing processes  

PubMed Central

The crosstalk between fibroblasts and keratinocytes is a vital component of the wound healing process, and involves the activity of a number of growth factors and cytokines. In this work, we develop a mathematical model of this crosstalk in order to elucidate the effects of these interactions on the regeneration of collagen in a wound that heals by second intention. We consider the role of four components that strongly affect this process: transforming growth factor-?, platelet-derived growth factor, interleukin-1 and keratinocyte growth factor. The impact of this network of interactions on the degradation of an initial fibrin clot, as well as its subsequent replacement by a matrix that is mainly composed of collagen, is described through an eight-component system of nonlinear partial differential equations. Numerical results, obtained in a two-dimensional domain, highlight key aspects of this multifarious process, such as re-epithelialization. The model is shown to reproduce many of the important features of normal wound healing. In addition, we use the model to simulate the treatment of two pathological cases: chronic hypoxia, which can lead to chronic wounds; and prolonged inflammation, which has been shown to lead to hypertrophic scarring. We find that our model predictions are qualitatively in agreement with previously reported observations and provide an alternative pathway for gaining insight into this complex biological process.

Menon, Shakti N.; Flegg, Jennifer A.; McCue, Scott W.; Schugart, Richard C.; Dawson, Rebecca A.; McElwain, D. L. Sean

2012-01-01

292

Keratinocytes in inflammatory skin diseases.  

PubMed

Although in the past, keratinocytes were considered simply as passive targets of immunological attack from infiltrating T lymphocytes, a number of studies have definitively demonstrated that keratinocytes actively participate in the cutaneous immune responses. Upon activation, keratinocytes express a plethora of cytokines, chemokines and accessory molecules, which can transmit both positive and negative signals to cells of innate and adaptive immunity. Dysregulation and abnormal expression of inflammatory mediators or their receptors in keratinocytes are relevant to the pathogenesis of chronic inflammatory skin diseases such as psoriasis, atopic dermatitis and allergic contact dermatitis. PMID:16101542

Albanesi, Cristina; Scarponi, Claudia; Giustizieri, Maria L; Girolomoni, Giampiero

2005-06-01

293

Fibroblast growth factor 7, secreted by breast fibroblasts, is an interleukin-1beta-induced paracrine growth factor for human breast cells.  

PubMed

Keratinocyte growth factor/fibroblast growth factor 7 (KGF/FGF7) is known to be a potent growth factor for mammary cells but its origin, cellular targets and mode of action in the breast are unclear. In this study, we carried out studies to determine the localisation of FGF7 and its receptor, and the related growth factor FGF10. We also determined the factors that regulate FGF7 release from stromal cells and the effects of FGF7 on normal and neoplastic breast cells. Using an FGF7-specific antibody which does not react with the FGF7 heparan sulphate proteoglycan (HSPG)-binding site, we showed epithelial and myoepithelial immunohistochemical staining in normal breast sections, and epithelial staining in breast carcinomas. Stromal staining was also detected in some lobular carcinomas as well as a subset of invasive ductal carcinomas. FGF10 and FGF receptor (FGFR)2 immunostaining showed a similar epithelial expression pattern, whereas no stromal staining was observed. We purified normal breast stromal, epithelial and myoepithelial cells and showed that FGF7 stimulated proliferation of both epithelial cell types, but not stromal fibroblasts. We also examined the effects of FGF7 on Matrigel-embedded organoids, containing both epithelial and myoepithelial cells, and showed FGF7 induced an increase in cellular proliferation. Furthermore, conditioned medium derived from stromal cells was shown to increase the proliferation of normal and neoplastic breast epithelial cells, which could be abolished by a neutralising antibody to FGF7. Finally, we showed that interleukin-1beta, but not oestradiol or other oestrogen receptor ligands, caused a dose-related FGF7 release. Further results also indicate that the epithelial localisation of FGF7 and FGF10 in breast tissue sections is likely to be due to their binding to their cognate receptor. In summary, our findings suggest that FGF7 is a paracrine growth factor in the breast. FGF7 is produced by the breast stromal fibroblasts and has profound proliferative and morphogenic roles on both epithelial and myoepithelial cells. PMID:12697038

Palmieri, C; Roberts-Clark, D; Assadi-Sabet, A; Coope, R C; O'Hare, M; Sunters, A; Hanby, A; Slade, M J; Gomm, J J; Lam, E W-F; Coombes, R C

2003-04-01

294

Fibroblast growth factor and insulin-like growth factor differentially modulate the apoptosis and G1 arrest induced by anti-epidermal growth factor receptor monoclonal antibody  

Microsoft Academic Search

DiFi human colon carcinoma cells are stimulated by the transforming growth factor-? (TGF-?)\\/epidermal growth factor (EGF) receptor autocrine loop. Exposure of DiFi cells to monoclonal antibody (mAb) 225, which blocks ligand-induced activation of the EGF receptor, induces G1 arrest and subsequent cell death via apoptosis. We investigated the signal pathways by which basic fibroblast growth factor (bFGF) and insulin-like growth

Bolin Liu; Min Fang; Yang Lu; John Mendelsohn; Zhen Fan

2001-01-01

295

Expression of connective tissue growth factor in human renal fibrosis  

Microsoft Academic Search

Expression of connective tissue growth factor in human renal fibrosis. Chronic renal failure may occur in etiologically diverse renal diseases and can be caused by hemodynamic, immunologic and metabolic factors. Initial damage may evoke irreversible scarring, which involves production of a number of proinflammatory and fibrogenic cytokines, including platelet-derived growth factor (PDGF) and transforming growth factor ? (TGF-?). Connective tissue

Yasuhiko Ito; Jan Aten; Richard J. Bende; Barry S. Oemar; Ton J. Rabelink; Jan J. Weening; Roel Goldschmeding

1998-01-01

296

Growth factors involved in prostate carcinogenesis.  

PubMed

Prostate cancer is the most common non-skin cancer affecting men in United States and the second leading cause of death after lung cancer. The clinical course of patients after given diagnosis of prostate cancer is highly variable and the underlying reasons for such variability remain elusive. To better understand the pathophysiology of prostate cancer, there has been a push to elucidate the molecular mechanisms that mediate the development and progression of prostate cancer. Recent literature has pointed that a complex interplay between various cytokines, growth factors, and androgen receptors regulate the growth and functions of the prostate gland. Amongst the currently implicated anomalous pathways involved in prostate oncogenesis, the IGF-IGFBP axis has been demonstrated to play a very important role, although the precise molecular events regulated by IGF remain to be elucidated. The tumor promoting functions of VEGF has been defined in tumor angiogenesis and currently remains the central focus of anti-angiogenesis therapy in prostate cancer. Another key cytokine, TGF-beta has tumor-suppressor functions in normal prostate gland, but its pleiotropic functions in prostate cancer are influenced by the hormonal state of the disease. In partnership with other deregulated growth factor signaling, the TGF-beta cascade has also been implicated in the spread of prostate cancer. Lastly, members of the EGFR family, particularly the HER2 receptor, have also been recognized as crucial elements of aberrant signal transduction pathways, which induce activation of downstream signaling, involved in cellular proliferation, cell survival, and angiogenesis. The abnormal function of a number of growth factors in prostate cancer biology explains the heterogeneity of its histologic grade, mode of presentation and disease prognosis. At the same time, continued research in this field allows for the potential development of drug therapies against a diverse pool of cancer causing targets. PMID:15769631

Kambhampati, Suman; Ray, Gibanananda; Sengupta, Krishanu; Reddy, Venkataprasanth P; Banerjee, Sushanta K; Van Veldhuizen, Peter J

2005-05-01

297

Inhibition of ultraviolet B-mediated activation of nuclear factor ?B in normal human epidermal keratinocytes by green tea Constituent (-)-epigallocatechin-3-gallate  

Microsoft Academic Search

Epigallocatechin-3-gallate (EGCG), the major constituent of green tea, possesses significant anti-inflammatory and cancer chemopreventive properties. Studies have shown the photochemopreventive effects of green tea and EGCG in cell culture, animal models, and human skin. The molecular mechanism(s) of photochemopreventive effects of EGCG are incompletely understood. We recently showed that EGCG treatment of the normal human epidermal keratinocytes (NHEK) inhibits ultraviolet

Farrukh Afaq; Vaqar M Adhami; Nihal Ahmad; Hasan Mukhtar; H Mukhtar

2003-01-01

298

Epidermal growth factor receptor and bladder cancer.  

PubMed

Muscle-invasive bladder cancer is a disease which causes significant morbidity and mortality. The two main forms of treatment for this disease include radical cystectomy and radical radiotherapy, but five year survival after treatment remains low at 40%. Many clinical and molecular risk factors have been shown to be associated with poor prognosis. One such factor is the expression of epidermal growth factor receptor (EGFR), which is overexpressed by many epithelial tumours, including bladder cancers. There are several methods of inhibiting the activity of EGFR and it may be that use of an anti-EGFR therapy, in combination with more conventional treatment, provides a method of improving the prognosis for muscle-invasive bladder cancer. PMID:12415079

Colquhoun, A J; Mellon, J K

2002-10-01

299

Biomechanical factors as triggers of vascular growth.  

PubMed

Haemodynamic factors influence all forms of vascular growth (vasculogenesis, angiogenesis, arteriogenesis). Because of its prominent role in atherosclerosis, shear stress has gained particular attention, but other factors such as circumferential stretch are equally important to maintain the integrity and to (re)model the vascular network. While these haemodynamic forces are crucial determinants of the appearance and the structure of the vasculature, they are in turn subjected to structural changes in the blood vessels, such as an increased arterial stiffness in chronic arterial hypertension and ageing. This results in an interplay between the various forces (biomechanical forces) and the involved vascular elements. Although many molecular mediators of biomechanical forces still need to be identified, there is plenty of evidence for the causal role of these forces in vascular growth processes, which will be summarized in this review. In addition, we will discuss the effects of concomitant diseases and disorders on these processes by altering either the biomechanics or their transduction into biological signals. Particularly endothelial dysfunction, diabetes, hypercholesterolaemia, and age affect mechanosensing and -transduction of flow signals, thereby underpinning their influence on cardiovascular health. Finally, current approaches to modify biomechanical forces to therapeutically modulate vascular growth in humans will be described. PMID:23580605

Hoefer, Imo E; den Adel, Brigit; Daemen, Mat J A P

2013-04-10

300

Increased epidermal growth factor receptors in gastric carcinomas.  

PubMed

The epidermal growth factor and the homologous alpha-tumor growth factor are mitogenic polypeptides that act by binding to the epidermal growth factor receptor. The present study investigated whether increased production of epidermal growth factor/alpha-tumor growth factor or increased density of epidermal growth factor receptors may occur in gastric carcinomas as compared with normal mucosa from the same individuals. Epidermal growth factor receptors were measurable by (125I)EGF-binding assays in 13 of 15 normal mucosas and in 15 of 15 carcinomas. The epidermal growth factor-binding capacity was significantly higher in carcinomas than in mucosa. A comparison of pairs of mucosa and carcinomas showed an increase of epidermal growth factor receptors in 9 of 15 carcinomas, no change in 3, and a decrease in 2 carcinomas. One mucinous adenocarcinoma contained extreme numbers of epidermal growth factor receptors (2445 fmol/mg protein) corresponding to a 320-fold increase over normal mucosa. Epidermal growth factor-like activity was increased in 2 of 22 carcinomas compared with mucosa. We conclude that relative overexpression of epidermal growth factor receptors occurs in a fraction of gastric carcinomas. Whether increased expression of epidermal growth factor receptors is associated with particular patterns of tumor progression needs to be investigated. PMID:2311877

Pfeiffer, A; Rothbauer, E; Wiebecke, B; Pratschke, E; Krämling, H J; Mann, K

1990-04-01

301

Genes for Epidermal Growth Factor Receptor, Transforming Growth Factor a, and Epidermal Growth Factor and Their Expression in Human Gliomas in Vivo  

Microsoft Academic Search

Anomalies of the epidermal growth factor receptor (EGFR) gene, including amplification, rearrangement, and overexpression, have been reported in malignant human gliomas in t'ivo. In vitro glioma cell lines coexpress EGFR and at least one of its ligands, transforming growth factor a, suggesting the existence of an autocrine growth stimulatory loop. \\\\Ve have studied the tumor tissue from 62 human glioma

A. Jonas Ekstrand; C. David James; Webster K. Cavenee; Barbara Seliger; Ralf F. Pettersson; V. Peter Collins

302

Human papilloma virus DNAs immortalize normal human mammary epithelial cells and reduce their growth factor requirements  

SciTech Connect

Human papilloma virus (HPV) types 16 and 18 are most commonly associated with cervical carcinoma in patients and induce immortalization of human keratinocytes in culture. HPV has not been associated with breast cancer. This report describes the immortalization of normal human mammary epithelial cells (76N) by plasmid pHPV18 or pHPV16, each containing the linearized viral genome. Transfectants were grown continuously for more than 60 passages, whereas 76N cells senesce after 18-20 passages. The transfectants also differ from 76N cells in cloning in a completely defined medium called D2 and growing a minimally supplemented defined medium (D3) containing epidermal growth factor. All transfectant tested contain integrated HPV DNA, express HPV RNA, and produce HPV E7 protein. HPV transfectants do not form tumors in a nude mouse assay. It is concluded that products of the HPV genome induce immortalization of human breast epithelial cells and reduce their growth factor requirements. This result raises the possibility that HPV might be involved in breast cancer. Furthermore, other tissue-specific primary epithelial cells that are presently difficult to grown and investigate may also be immortalized by HPV.

Band, V.; Zajchowski, D.; Kulesa, V.; Sager, R. (Dana-Farber Cancer Institute, Boston, MA (USA))

1990-01-01

303

Modulation of arsenic-induced epidermal growth factor receptor pathway signalling by resveratrol.  

PubMed

Arsenic (As) is both a human carcinogen and an effective anticancer drug. These aspects of arsenic toxicity develop as a consequence of arsenic-induced oxidative stress and modifications to signal pathway activity which alter gene expression. Resveratrol (RVL) a food antioxidant found in grapes and other fruits, exhibits anti-carcinogenic properties by reducing oxidative stress and restoring signal pathway control. This study investigated the impact of RVL on arsenite [As(III)]-induced cell signalling in HaCaT keratinocytes by assaying phosphorylation status of epidermal growth factor receptor (EGFR) signalling intermediates and measuring changes in expression of Phase II and DNA repair biomarkers. As(III) exposure produced dose-dependent toxicity which was associated with increased activation of EGFR pathway intermediates, cSrc, Rac1 and extracellular signal-regulated kinases 1 and 2 (ERK1/2). Arsenic-mediated ERK1/2 activation negatively regulated DNA polymerase beta expression and up regulated heme-oxygenase-1 at toxic concentrations. RVL treatment modulated As(III)-mediated ERK1/2 activation by shifting the balance of cSrc regulatory domain phosphorylation. These effects significantly altered the response of the EGFR pathway to growth factor-induced stimulation. Our research provides evidence that treatment with pharmacologically relevant doses of RVL influences cellular responses to As(III), largely due to RVL-mediated changes to Src and ERK1/2 activation. PMID:22634503

Herbert, Katharine J; Snow, Elizabeth T

2012-05-23

304

Toll-Like Receptor Expression in Human Keratinocytes: Nuclear Factor ?B Controlled Gene Activation by Staphylococcus aureus is Toll-Like Receptor 2 But Not Toll-Like Receptor 4 or Platelet Activating Factor Receptor Dependent  

Microsoft Academic Search

Cultured primary human keratinocytes were screened for their expression of various members of the toll-like receptor (TLR) family. Keratinocytes were found to constitutively express TLR1, TLR2, TLR3, TLR5, and TLR9 but not TLR4, TLR6, TLR7, TLR8, or TLR10 as shown by polymerase chain reaction analysis. The expression of the crucial receptor for signaling of staphylococcal compounds TLR2 was also confirmed

Martin Mempel; Verena Voelcker; Gabriele Köllisch; Christian Plank; Roland Rad; Markus Gerhard; Christina Schnopp; Peter Fraunberger; Autar K. Walli; Johannes Ring; Dietrich Abeck; Markus Ollert

2003-01-01

305

Pituitary insulin-like growth factors  

Microsoft Academic Search

Insulin-like growth factor (IGF)-I and IGF-II peptides as well as their mRNAs are produced in many organs, including the pituitary.\\u000a Although IGF-I and IGF-II peptides are localized in endocrine cells of the anterior pituitary, IGF-I mRNA can be detected\\u000a throughout the adenohypophysis, and IGF-II mRNA is abundant in intermediate and neural lobes.\\u000a \\u000a It is well-established that both circulating and intrinsic

Shunichi Yokoyama; Lucia Stefaneanu; Kalman Kovacs

1997-01-01

306

Transforming growth factor-beta and breast cancer: Tumor promoting effects of transforming growth factor-?  

Microsoft Academic Search

The transforming growth factor (TGF)-?s are potent growth inhibitors of normal epithelial cells. In established tumor cell systems, however, the preponderant experimental evidence suggests that TGF-?s can foster tumor-host interactions that indirectly support the viability and\\/or progression of cancer cells. The timing of this 'TGF-? switch' during the progressive transformation of epithelial cells is not clear. More recent evidence also

Nancy Dumont; Carlos L Arteaga

2000-01-01

307

Fabrication of Growth Factor Array Using an Inkjet Printer  

Microsoft Academic Search

\\u000a Although multiple growth factors influence the fate of cells in vivo, it is technically difficult to reproduce similar condition\\u000a in vitro. To overcome this problem, we have developed growth factor array, a system to study compound effects of multiple\\u000a growth factors fabricated with a commercial color inkjet printer. By replacing color inks to 2–4 growth factors and printing\\u000a them on

Kohei Watanabe; Tomoyo Fujiyama; Rina Mitsutake; Masaya Watanabe; Yukiko Tazaki; Takeshi Miyazaki; Ryoichi Matsuda

308

Absence of tumorigenicity in athymic mice by normal human epidermal keratinocytes after culture in serum-free medium.  

PubMed

The very rapid growth rate (1 population doubling/day) of normal human epidermal keratinocytes (HK) cultured in serum-free medium can be utilized for wound closure in burn treatment. However, rapid growth in vitro may present the possibility of neoplastic transformation. To investigate this possibility, HK were cultured from primary isolation to large populations in MCDB 153 medium supplemented with epidermal growth factor (EGF, 10 ng/ml), insulin (5 micrograms/ml), hydrocortisone (0.5 micrograms/ml), and Bovine Pituitary Extract (BPE, 70 micrograms/ml). HK were studied for their ability to form tumors in athymic mice after subcutaneous inoculation. Sixteen separate HK strains were inoculated from primary cultures, or from secondary cultures either before or after storage in liquid nitrogen. Transformed cell lines, SCC 13 and FL, derived from human epithelial carcinomata were used as controls for tumor formation. HK formed no tumors (0/79) after 26 weeks incubation, SCC 13 formed nodular tumors (3/5) after 20 weeks incubation, and FL formed tumors (5/5) after 4 weeks incubation. HK cells were not found by histological examination of inoculation sites of keratinocyte cultures derived from primary culture from skin. In contrast, palpable tumors from both SCC 13 and FL were returned to tissue culture and continued to proliferate. These results support the conclusion that the rapid growth rate of human epidermal keratinocytes in vitro can be attributed to permissive culture conditions, and not to neoplastic transformation. PMID:1540941

Boyce, S T; Foreman, T J; Furmanski, P; Hansbrough, J F

1992-02-29

309

Synthetic chimeras of mouse growth factor-associated glandular kallikreins. II. Growth factor binding properties.  

PubMed Central

Six chimeric constructs of the sequentially similar growth factor-associated kallikreins-epidermal growth factor binding protein (EGF-BP) and the gamma-subunit of nerve growth factor (gamma-NGF)--have been expressed, and their ability to generate complexes with epidermal growth factor (EGF) and beta-NGF, analogous to the high molecular weight forms (7S NGF and HMW-EGF) found in the mouse submaxillary gland, evaluated. The chimeras are distinguished by the interchange of three regions composing the amino, middle, and carboxyl terminal regions that encompass four surface loops possibly involved in specific growth factor interactions. Native beta-NGF (along with native alpha-NGF) formed complexes indistinguishable from naturally occurring 7S NGF, characterized by an alpha 2 beta gamma 2 structure (where beta-NGF is itself a dimer), with recombinant (r) gamma-NGF and with a chimera in which the amino terminal region from EGF-BP was substituted. Two other chimeras containing either the middle or carboxyl terminal regions of gamma-NGF showed weaker ability to form 7S complexes. Thus, all chimeras containing two segments from gamma-NGF retained at least some ability to form the 7S complex. rEGF-BP reacted weakly with EGF, but the chimera composed of the amino and middle segments of EGF-BP and the carboxyl terminal segment of gamma-NGF formed a nativelike HMW-EGF complex. None of the other chimeras appeared to bind EGF. These results identify amino acid positions within each kallikrein that participate in strong growth factor interactions and demonstrate that, outside of active site contacts, different regions of the kallikreins are involved in the binding of EGF and beta-NGF, respectively.

Blaber, M.; Isackson, P. J.; Holden, H. M.; Bradshaw, R. A.

1993-01-01

310

Hepatocyte growth factor in renal failure: Promise and reality  

Microsoft Academic Search

Hepatocyte growth factor in renal failure: Promise and reality. Can science discover some secrets of Greek mythology? In the case of Prometheus, we can now suppose that his amazing hepatic regeneration was caused by a peptide growth factor called hepatocyte growth factor (HGF). Increasing evidence indicates that HGF acts as a multifunctional cytokine on different cell types. This review addresses

Gustavo A Vargas; Andreas Hoeflich; Peter M Jehle

2000-01-01

311

Role of epidermal growth factor in peptic ulcer healing  

Microsoft Academic Search

In recent years, increasing interest has been focused on peptide growth factors, and impressive progress has been made in the understanding of their role in tumor development and progression. However, evidence is mounting that peptides such as epidermal growth factor and transforming growth factor-alpha may be of much more physiological than pathological importance. This brief article is intended to give

A. Calabrò; S. Milani; I. Paladini; B. Orsini; G. Salvadori; C. Surrenti

1995-01-01

312

Feedback inhibitors of the epidermal growth factor receptor signaling pathways  

Microsoft Academic Search

The epidermal growth factor receptor family tyrosine kinases transduce signals for cell proliferation and migration and contribute to tumorigenesis. A recent extensive research has highlighted the major roles of the negative regulators of complex epidermal growth factor receptor signaling networks. These regulators fine-tune signaling under physiological conditions. When their expression is downregulated, the resultant aberrant epidermal growth factor receptor signaling

Noriko Gotoh

2009-01-01

313

Murine oligodendroglial cells express nerve growth factor.  

PubMed Central

The studies reported here present evidence for the expression of nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) by an oligodendroglial cell line and of NGF by oligodendrocytes in mouse primary culture. An immortalized oligodendroglial cell line (N19) expressing markers for immature oligodendrocytes stimulated PC12 cells to elaborate processes. Polymerase chain reaction analysis with degenerate primers indicated that the N19 cells expressed the mRNAs for the neurotrophic factors NGF and BDNF. Northern blot analysis confirmed that the N19 cells expressed the 1.3-kb NGF mRNA and the 1.4- and 4-kb BDNF mRNAs. In situ hybridization histochemistry identified the presence of NGF mRNAs in 9-day primary oligodendroglial cultures. Combined immunocytochemistry and in situ hybridization histochemistry colocalized NGF mRNA within primary cultured cells that immunostained for the oligodendrocyte marker galactocerebroside (GC). Double-immunofluorescence analysis also colocalized NGF protein within GC+ cells and within A2B5+ cells, a marker for oligodendrocyte progenitors. These results show that oligodendroglia and their precursor cells can express the neurotrophic factor NGF. They suggest that cells in the oligodendrocyte lineage may play an active role in neurite extension through fiber tracts in addition to myelination. Images

Byravan, S; Foster, L M; Phan, T; Verity, A N; Campagnoni, A T

1994-01-01

314

Reproducibility of serum cytokines and growth factors  

PubMed Central

Background In most studies, circulating biomarkers are usually assessed from a single sample, assuming that this single measurement represents the long-term biomarker status of the individual. Such an assumption is rarely tested although it may not be valid for all biomarkers. The objective of this study was to investigate the temporal reproducibility of a panel of cytokines and growth factors. Methods Thirty-five postmenopausal women with two annual visits and 30 premenopausal women with three annual visits were randomly selected from the participants in an existing prospective cohort. A total of 23 serum cytokines, nine growth factors and C-reactive protein (CRP) were measured using the Luminex xMap™ technology. In addition, for eight biomarkers, regular and high sensitivity (hs) assays were compared. Results The biomarkers with adequate (>60%) detection rates and acceptable (?0.55) intra-class correlation coefficients (ICCs) were: hsIL-1?, IL-1RA, hsIL-2, hsIL-4, hsIL-5, hsIL-6, hsIL-10, IL-12p40, hsIL-12p70, hsTNF-?, TNF-R1, TNF-R2, CRP, HGF, NGF, and EGFR. The remaining biomarkers either had low temporal reproducibility or were undetectable in more than 40% of samples. Conclusions The results suggest that 16 of the 41 biomarkers measured with Luminex technology showed sufficient sensitivity and temporal reproducibility in sera.

Gu, Yian; Zeleniuch-Jacquotte, Anne; Linkov, Faina; Koenig, Karen L.; Liu, Mengling; Velikokhatnaya, Lyudmila; Shore, Roy E.; Marrangoni, Adele; Toniolo, Paolo; Lokshin, Anna E.; Arslan, Alan A.

2010-01-01

315

Transforming growth factor beta regulates thyroid growth. Role in the pathogenesis of nontoxic goiter.  

PubMed Central

The production and growth regulatory activity of transforming growth factor beta were studied in human thyroid tissue. As estimated by its mRNA expression in fresh tissue samples, transforming growth factor beta was produced in normal and in diseased thyroid glands. Transforming growth factor beta mRNA was mainly produced by thyroid follicular cells and in lesser quantities by thyroid infiltrating mononuclear cells. The concentrations of transforming growth factor beta mRNA were lower in iodine-deficient nontoxic goiter than in Graves' disease and normal thyroid tissue. Transforming growth factor beta protein secretion by cultured thyroid follicular cells was also low in nontoxic goiter, but could be increased by addition of sodium iodide (10 microM) to the culture medium. Recombinant transforming growth factor beta did not affect basal tritiated thymidine incorporation in cultured thyroid follicular cells, but inhibited, at a concentration of 10 ng/ml, the growth stimulatory influence of insulin-like growth factor I, epidermal growth factor, transforming growth factor alpha, TSH, and partly that of normal human serum on cultured thyroid follicular cells. This inhibition was greater in Graves' disease than in nontoxic goiter. These results suggest that transforming growth factor beta may act as an autocrine growth inhibitor on thyroid follicular cells. Decreased transforming growth factor beta production and decreased responsiveness to transforming growth factor beta may be cofactors in the pathogenesis of iodine-deficient nontoxic goiter. Images

Grubeck-Loebenstein, B; Buchan, G; Sadeghi, R; Kissonerghis, M; Londei, M; Turner, M; Pirich, K; Roka, R; Niederle, B; Kassal, H

1989-01-01

316

The prognostic significance of growth factors and growth factor receptors in gastric adenocarcinoma.  

PubMed

We evaluated growth factors/receptors expression in gastric adenocarcinoma. Immunohistochemistry was used to evaluate epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF), VEGF-D, VEGF receptor (VEGFR)-2, VEGFR-3, transforming growth factor (TGF)-?, TGF-?1, and TGF-?-RII in tissue microarrays of adenocarcinoma, dysplasia, metaplasia, and gastritis. In adenocarcinoma, the expression rates of EGFR, VEGF, VEGF-D, VEGFR-2, VEGFR-3, TGF-?, TGF-?1, and TGF-?-RII were 2.0%, 0%, 10.7%, 4.4%, 11.2%, 26.3%, 9.4%, and 19.5%, respectively. VEGF-D, TGF-?, TGF-?1, and TGF-?-RII expression rate were higher in adenocarcinoma than in other groups. TGF-?-RII expression was correlated with VEGFR-3, VEGF-D, and TGF-? expression in adenocarcinomas. Tumor location, histologic type, stage, lymphatic invasion, perineural invasion, angioinvasion, VEGF-D, and VEGFR-2 expressions were associated with patient survival in a log rank test and advanced stage and positive expression of VEGF-D were poor prognostic factors using Cox analysis. VEGF-D expression may be of prognostic value in gastric adenocarcinoma, whereas EGFR and TGF family expression may only have a minor influence. PMID:23030255

Kim, Jung Yeon; Jeon, Tae Joo; Bae, Byung-Noe; Kwon, Ji Eun; Kim, Hyun-Jung; Park, Kyeongmee; Shin, Eunah

2012-08-17

317

Effects of recombinant basic fibroblast growth factor, insulin-like growth factor-II and transforming growth factor- ? 1 on dog dental pulp cells in vivo  

Microsoft Academic Search

The effects of recombinant basic fibroblast growth factor (bFGF), insulin-like growth factor (IGF)-II and transforming growth factor (TGF)-?1 on dental pulp cells were investigated by light and transmission electron microscopy after their implantation for 1 and 3 weeks at central sites of mechanically exposed pulps in dog molar and canine teeth. The implants were Millipore filters that have been soaked

D. Tziafas; A. Alvanou; S. Papadimitriou; J. Gasic; A. Komnenou

1998-01-01

318

Scatter factor regulation of integrin expression and function on oral epithelial cells  

Microsoft Academic Search

Integrin receptors and the growth factor, scatter factor (SF; also known as hepatocyte growth factor) have been shown to modulate similar cellular processes including embryogenesis, wound healing and tumour invasion. The purpose of this study was to examine the role of SF in the regulation of integrin expression, migration and adhesion in normal human oral keratinocytes (NHK). Integrin expression was

Sopee Poomsawat; Simon A. Whawell; Matthew J. Morgan; Gareth J. Thomas; Paul M. Speight

2003-01-01

319

Reduced Expression of Fibroblast Growth Factor Receptor 2IIIb in Hepatocellular Carcinoma Induces a More Aggressive Growth  

PubMed Central

Fibroblast growth factor receptor 2 isoform b (FGFR2-IIIb) is highly expressed in hepatocytes and plays an important role in liver homeostasis and regeneration. Here, we analyzed the expression and function of FGFR2-IIIb in hepatocellular carcinoma (HCC). FGFR2-IIIb expression in HCC tissues and cell lines was lower than in primary human hepatocytes and nontumorous tissue. FGFR2-IIIb-negative HCCs showed a significantly higher Ki-67 labeling index, and loss of FGFR2-IIIb expression correlated significantly with vascular invasion and more advanced tumor stages. A decrease in FGFR-2IIIb expression in HCC cell lines was not related to promoter hypermethylation. However, PCR analysis indicated that chromosomal deletion at 10q accounted for the loss of FGFR2 expression in a subset of HCC cells. FGFR2-IIIb re-expression in stable transfected HCC cell lines induced a higher basal apoptosis rate and a significantly reduced proliferation and migratory potential in vitro. In nude mice, FGFR2-IIIb re-expressing HCC cells grew significantly slower, and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay revealed higher apoptosis rates. The antitumorigenic effects of FGFR2-IIIb expression in HCC cells were not affected by keratinocyte growth factor or an inhibitor of FGFR-phosphorylation, indicating that they are independent of tyrosine kinase activation. In conclusion, our data indicate that FGFR2-IIIb inhibits tumorigenicity of HCC cells. Identification of the molecular mechanisms promoting regeneration in normal tissue while suppressing malignancy may lead to novel therapeutic targets of this highly aggressive tumor.

Amann, Thomas; Bataille, Frauke; Spruss, Thilo; Dettmer, Katja; Wild, Peter; Liedtke, Christian; Muhlbauer, Marcus; Kiefer, Paul; Oefner, Peter J.; Trautwein, Christian; Bosserhoff, Anja-Katrin; Hellerbrand, Claus

2010-01-01

320

Reduced expression of fibroblast growth factor receptor 2IIIb in hepatocellular carcinoma induces a more aggressive growth.  

PubMed

Fibroblast growth factor receptor 2 isoform b (FGFR2-IIIb) is highly expressed in hepatocytes and plays an important role in liver homeostasis and regeneration. Here, we analyzed the expression and function of FGFR2-IIIb in hepatocellular carcinoma (HCC). FGFR2-IIIb expression in HCC tissues and cell lines was lower than in primary human hepatocytes and nontumorous tissue. FGFR2-IIIb-negative HCCs showed a significantly higher Ki-67 labeling index, and loss of FGFR2-IIIb expression correlated significantly with vascular invasion and more advanced tumor stages. A decrease in FGFR-2IIIb expression in HCC cell lines was not related to promoter hypermethylation. However, PCR analysis indicated that chromosomal deletion at 10q accounted for the loss of FGFR2 expression in a subset of HCC cells. FGFR2-IIIb re-expression in stable transfected HCC cell lines induced a higher basal apoptosis rate and a significantly reduced proliferation and migratory potential in vitro. In nude mice, FGFR2-IIIb re-expressing HCC cells grew significantly slower, and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay revealed higher apoptosis rates. The antitumorigenic effects of FGFR2-IIIb expression in HCC cells were not affected by keratinocyte growth factor or an inhibitor of FGFR-phosphorylation, indicating that they are independent of tyrosine kinase activation. In conclusion, our data indicate that FGFR2-IIIb inhibits tumorigenicity of HCC cells. Identification of the molecular mechanisms promoting regeneration in normal tissue while suppressing malignancy may lead to novel therapeutic targets of this highly aggressive tumor. PMID:20093481

Amann, Thomas; Bataille, Frauke; Spruss, Thilo; Dettmer, Katja; Wild, Peter; Liedtke, Christian; Mühlbauer, Marcus; Kiefer, Paul; Oefner, Peter J; Trautwein, Christian; Bosserhoff, Anja-Katrin; Hellerbrand, Claus

2010-01-21

321

Sequential Delivery of Basic Fibroblast Growth Factor and Platelet-Derived Growth Factor for Angiogenesis  

PubMed Central

An externally regulated delivery model that permits temporal separation of multiple angiogenic factors was used for the delivery of basic fibroblast growth factor (bFGF) and platelet-derived growth factor (PDGF). While bFGF plays a significant role in the sprouting of new capillaries, PDGF plays a role in the recruitment of mural cells, which stabilize neovessels. However, these two factors have been shown to inhibit each other, when presented together. Using the externally regulated model, sequential delivery of bFGF and PDGF led to not only increased endothelial cell migration, but also endothelial cell and vascular pericyte colocalization. More importantly, this delivery strategy was able to induce red blood cell-filled neovessels, suggesting integration of angiogenesis with the existing vasculature.

Tengood, Jillian E.; Ridenour, Ryan; Brodsky, Ross; Russell, Alan J.

2011-01-01

322

Induction of matrix metalloproteinase-1 (MMP-1) during epidermal invasion of the stroma in human skin organ culture: keratinocyte stimulation of fibroblast MMP-1 production  

PubMed Central

Organ cultures of human skin were incubated for 8 days under growth factor-free conditions or exposed to 10?ng ml?1 of human recombinant epidermal growth factor (EGF) during the incubation period. Normal histological features were preserved in the absence of growth factor, while epithelial cells underwent a proliferative response and invaded the underlying stroma in the presence of exogenous EGF. The same concentrations of EGF that induced stromal invasion also resulted in up-regulation of matrix metalloproteinase-9 (MMP-9; 92-kD gelatinase B) in organ culture and keratinocyte monolayer culture, and expression of MMP-1 (interstitial collagenase) in organ culture and fibroblast monolayer culture. When skin organ cultures were exposed to a potent, irreversible EGF–receptor tyrosine kinase (EGF–RTK) antagonist along with EGF, abnormal histological features were reversed, and MMP-9 production was suppressed. In contrast, EGF-RKT antagonism had only a modest inhibitory effect on MMP-1 production. Culture fluid from keratinocytes grown in monolayer culture stimulated fibroblast proliferation and MMP-1 elaboration. Treatment of fibroblasts with the same EGF–RTK antagonist inhibited keratinocyte-induced fibroblast proliferation but had only a modest inhibitory effect (approximately 20% inhibition) on MMP-1 production. In contrast, treatment of dermal fibroblasts with Interleukin-1 Receptor Antagonist had no effect on keratinocyte-induced fibroblast growth but strongly inhibited MMP-1 production (greater than 70% inhibition). These data indicate that stromal invasion by epithelial cells in EGF-treated skin is associated with events occurring in both the epidermis and dermis. The direct effect of the exogenous growth factor appears to be primarily on the epidermis. Dermal events reflect, at least in part, a response to factors elaborated in the epidermis. © 2001 Cancer Research Campaign??http://www.bjcancer.com

Moon, S E; Dame, M K; Remick, D R; Elder, J T; Varani, J

2001-01-01

323

Exogenous Addition of a C-Xylopyranoside Derivative Stimulates Keratinocyte Dermatan Sulfate Synthesis and Promotes Migration  

PubMed Central

As C-Xyloside has been suggested to be an initiator of glycosaminoglycan (GAG) synthesis, and GAGs such as Dermatan sulfate (DS) are potent enhancers of fibroblast growth factor (FGF) - 10 action, we investigated if a C-Xylopyranoside derivative, (C-?-D-xylopyranoside-2-hydroxy-propane, C-Xyloside), could promote DS production by cultured normal human keratinocytes, how this occurs and if C-Xyloside could also stimulate FGF-dependent cell migration and proliferation. C-Xyloside-treated keratinocytes greatly increased secretion of total sulfated GAGs. Majority of the induced GAG was chondroitin sulfate/dermatan sulfate (CS/DS) of which the major secreted GAG was DS. Cells lacking xylosyltransferase enzymatic activity demonstrated that C-Xyloside was able to stimulate GAG synthesis without addition to core proteins. Consistent with the observed increase in DS, keratinocytes treated with C-Xyloside showed enhanced migration in response to FGF-10 and secreted into their culture media GAGs that promoted FGF-10-dependent cellular proliferation. These results indicate that C-Xyloside may enhance epithelial repair by serving as an initiator of DS synthesis.

Muto, Jun; Naidu, Nandita Natasha; Yamasaki, Kenshi; Pineau, Nathalie

2011-01-01

324

Hair cycle and wound healing in mice with a keratinocyte-restricted deletion of FAK  

PubMed Central

Focal adhesion kinase (FAK) is a critical component in transducing signals downstream of both integrins and growth factor receptors. To determine how the loss of FAK affects the epidermis in vivo, we have generated a mouse model with a keratinocyte-restricted deletion of fak(FAKK5 KO mice). FAKK5 KO mice displayed three major phenotypes – irregularities of hair cycle, sebaceous glands hypoplasia, and a thinner epidermis – pointing to defects in the proliferative capacity of multipotent stem cells found in the bulge. FAK-null keratinocytes in conventional primary culture undergo massive apoptosis hindering further analyses, whereas the defects observed in vivo do not shorten the mouse lifespan. These results suggest that the structure and the signaling environment of the native tissue may overcome the lack of signaling through FAK. Our findings point to the importance of in vivo and threedimensional in vitro models in analyses of cell migration, proliferation, and survival. Surprisingly, the difference between FAKloxP/+ and FAKK5 KO mice in wound closure was not statistically significant, suggesting that in vivo loss of FAK does not affect migration/proliferation of basal keratinocytes in the same way as it affects multipotent stem cells of the skin.

Essayem, S; Kovacic-Milivojevic, B; Baumbusch, C; McDonagh, S; Dolganov, G; Howerton, K; Larocque, N; Mauro, T; Ramirez, A; Ramos, DM; Fisher, SJ; Jorcano, JL; Beggs, HE; Reichardt, LF; Ilic, D

2009-01-01

325

N-Glycosylation of ss4 Integrin Controls the Adhesion and Motility of Keratinocytes  

PubMed Central

?6ß4 integrin is an essential component of hemidesmosomes and modulates cell migration in wound healing and cancer invasion. To elucidate the role of N-glycosylation on ß4 integrin, we investigated keratinocyte adhesion and migration through the re-expression of wild-type or N-glycosylation-defective ß4 integrin (?Nß4) in ß4 integrin null keratinocytes. N-glycosylation of ß4 integrin was not essential for the heterodimer formation of ß4 integrin with ?6 integrin and its expression on a cell surface, but N-glycosylation was required for integrin-mediated cell adhesion and migration. Concomitantly with the reduction of ß4 integrin in the membrane microdomain, the intracellular signals of Akt and ERK activation were decreased in cells expressing ?Nß4 integrin. Forced cross-linking of ß4 integrin rescued the decreased ERK activation in ?Nß4 integrin-expressing cells to a similar extent in wild-type ß4 integrin-expressing cells. Surprisingly, compared with cells expressing wild-type ß4 integrin, an alternation in N-glycan structures expressed on epidermal growth factor receptor (EGFR), and the induction of a stronger association between EGFR and ß4 integrin were observed in ?Nß4 integrin-expressing cells. These results clearly demonstrated that N-glycosylation on ß4 integrin plays an essential role in keratinocyte cellular function by allowing the appropriate complex formation on cell surfaces.

Kariya, Yoshinobu; Gu, Jianguo

2011-01-01

326

Efficient and rapid generation of induced pluripotent stem cells from human keratinocytes.  

PubMed

The utility of induced pluripotent stem (iPS) cells for investigating the molecular logic of pluripotency and for eventual clinical application is limited by the low efficiency of current methods for reprogramming. Here we show that reprogramming of juvenile human primary keratinocytes by retroviral transduction with OCT4, SOX2, KLF4 and c-MYC is at least 100-fold more efficient and twofold faster compared with reprogramming of human fibroblasts. Keratinocyte-derived iPS (KiPS) cells appear indistinguishable from human embryonic stem cells in colony morphology, growth properties, expression of pluripotency-associated transcription factors and surface markers, global gene expression profiles and differentiation potential in vitro and in vivo. To underscore the efficiency and practicability of this technology, we generated KiPS cells from single adult human hairs. Our findings provide an experimental model for investigating the bases of cellular reprogramming and highlight potential advantages of using keratinocytes to generate patient-specific iPS cells. PMID:18931654

Aasen, Trond; Raya, Angel; Barrero, Maria J; Garreta, Elena; Consiglio, Antonella; Gonzalez, Federico; Vassena, Rita; Bili?, Josipa; Pekarik, Vladimir; Tiscornia, Gustavo; Edel, Michael; Boué, Stéphanie; Izpisúa Belmonte, Juan Carlos

2008-10-17

327

Epidermal Expression of Neuropilin 1 Protects Murine keratinocytes from UVB-induced apoptosis  

PubMed Central

Background Neuropilin 1 (NRP1) is expressed on several cell types including neurons and endothelial cells, where it functions as an important regulator in development and during angiogenesis. As a cell surface receptor, NRP1 is able to bind to members of the VEGF family of growth factors and to secreted class 3 semaphorins. Neuropilin 1 is also highly expressed in keratinocytes, but the function of NRP1 in epidermal physiology and pathology is still unclear. Methods and Results To elucidate the role of NRP1 in skin in vivo we generated an epidermis-specific neuropilin 1 knock out mouse model by using the Cre-LoxP-System. Mice were viable and fertile and did not display any obvious skin or hair defects. After challenge with UVB irradiation, we found that deletion of epidermal NRP1 leads to increased rates of apoptosis both in vitro and in vivo. NRP1-deficient primary keratinocytes cultured in vitro showed significantly higher rates of apoptosis 24 hours after UVB. Likewise, there is a significant increase of active caspase 3 positive cells in the epidermis of Keratin 14-Cre-NRP1 (?/?) mice 24 hours after UVB irradiation. By Western Blot analysis we could show that NRP1 influences the cytosolic levels of Bcl-2, a pro-survival member of the Bcl-2 family. After UVB irradiation the amounts of Bcl-2 decrease in both protein extracts from murine epidermis and in NRP1-deficient keratinocytes in vitro, whereas wild type cells retain their Bcl-2 levels. Likewise, levels of phospho-Erk and Rac1 were lower in NRP1-knock out keratinocytes, whereas levels of pro-apoptotic p53 were higher. Conclusion NRP1 expression in keratinocytes is dispensable for normal skin development. Upon UVB challenge, NRP1 contributes to the prevention of keratinocyte apoptosis. This pro-survival function of NRP1 is accompanied by the maintenance of high levels of the antiapoptotic regulator Bcl-2 and by lower levels of pro-apoptotic p53.

Riese, Anna; Eilert, Yvonne; Meyer, Yvonne; Arin, Meral; Baron, Jens M.; Eming, Sabine; Krieg, Thomas; Kurschat, Peter

2012-01-01

328

Vascular endothelial growth factor and vascular endothelial growth factor receptor-2 expression in mdx mouse brain  

Microsoft Academic Search

Recent data have demonstrated that vascular endothelial growth factor (VEGF) is expressed by subsets of neurons, coincident with angiogenesis within its developing cerebral cortex. In this study, with the aim of elucidating the mechanisms of vascular involvement during brain impairment in Duchenne muscular distrophy (DMD), we have correlated the vascular density with VEGF and VEGF receptor-2 (VEGFR-2) expression in the

Beatrice Nico; Patrizia Corsi; Angelo Vacca; Luisa Roncali; Domenico Ribatti

2002-01-01

329

Expression of Epidermal Growth Factor and Epidermal Growth Factor Receptor Immunoreactivity in the Asthmatic Human Airway  

Microsoft Academic Search

Chronic airway inflammation, one of the pathophysiologic features of bronchial asthma, is suspected to be responsible for irreversible pathological changes of airways, called airway remodeling . To exam- ine the mechanisms of airway remodeling in asthma, we investigated the expression of epidermal growth factor (EGF) and its receptor immunohistochemically in asthmatic human airways. Airway specimens from seven patients with asthma

MASARU AMISHIMA; MITSURU MUNAKATA; YASUYUKI NASUHARA; ATSUKO SATO; TORU TAKAHASHI; YUKIHIKO HOMMA; YOSHIKAZU KAWAKAMI

1998-01-01

330

An Epidermal Growth Factor Receptor Intron 1 Polymorphism Mediates Response to Epidermal Growth Factor Receptor Inhibitors  

Microsoft Academic Search

This study tested the hypothesis that the number of CA single sequence repeat (CA-SSR) in the intron 1 of the epidermal growth factor receptor (egfr) gene, which affects transcription efficiency of the gene, is associated with the response to EGFR inhibitors. To this end, we determined the number of CA dinucleotides in the intron 1 of the egfr gene in

Maria L. Amador; Darin Oppenheimer; Sofia Perea; Anirban Maitra; George Cusati; Christi Iacobuzio-Donahue; Sharyn D. Baker; Raheela Ashfaq; Chris Takimoto; Arlene Forastiere; Manuel Hidalgo

2004-01-01

331

Connective tissue growth factor binds vascular endothelial growth factor (VEGF) and inhibits VEGF-induced angiogenesis  

Microsoft Academic Search

Vascular endothelial growth factor (VEGF) is a strong angiogenic mitogen and plays important roles in angiogenesis under various pathophysiological conditions. The in vivo angiogenic activity of secreted VEGF may be regulated by extracellular inhibitors, because it is also produced in avascular tissues such as the cartilage. To seek the binding inhibitors against VEGF, we screened the chondrocyte cDNA library by

Isao Inoki; Takayuki Shiomi; Gakuji Hashimoto; Hiroyuki Enomoto; Hiroyuki Nakamura; Ken-ichi Makino; Eiji Ikeda; Shigeo Takata; Ken-ichi Kobayashi; Yasunori Okada

2001-01-01

332

Scatter factor\\/hepatocyte growth factor is essential for liver development  

Microsoft Academic Search

POLYPEPTIDE growth factors are important effectors of cell growth and differentiation in vitro and are thought to be critical for processes such as specification of cell fate, tissue growth and organogenesis in vivo. Scatter factor1-3\\/hepatocyte growth factor4,5 (SF\\/HGF) is the prototype of an emerging family of growth factors that resemble in their domain structure and mechanism of activation the blood

Claudia Schmidt; Friedhelm Bladt; Stefanie Goedecke; Volker Brinkmann; Wolfgang Zschiesche; Melanie Sharpe; Ermanno Gherardi; Carmen Birchmeler

1995-01-01

333

Shuttling of the autoantigen La between nucleus and cell surface after uv irradiation of human keratinocytes  

SciTech Connect

During the past years we have established that the nuclear autoantigen La shuttles between the nucleus and the cytoplasm in tumor cells after inhibition of transcription or virus infection. We reinvestigated this shuttling using primary human keratinocytes from both healthy donors and patients with xeroderma pigmentosum. Ultraviolet irradiation resulted in both an inhibition of transcription and a translocation of La protein from the nucleus to the cytoplasm. After a prolonged inhibition of transcription La protein relocated into the nucleus and assembled with nuclear storage regions. The uv-induced shuttling included a translocation to the cell surface, where La protein colocalized with epidermal growth factor receptors.

Bachmann, M.; Chang, S.; Slor, H.; Kukulies, J.; Mueller, W.E. (Universitaet, Mainz (Germany, F.R.))

1990-12-01

334

Isolation and characterization of a spontaneously arising long-lived line of human keratinocytes (NM1)  

Microsoft Academic Search

Summary  The long-lived keratinocyte line, NM1, was isolated from the epidermis of a pool of foreskins obtained from apprently, normal\\u000a neonates at the time of circumcision. Cultures were initiated in Dulbecco’s minimal essential medium containing 20% fetal\\u000a bovine serum, 0.4 ?g\\/ml hydrocortisone, 10?9\\u000a M cholera, toxin, and 10 ng\\/ml epidermal growth factor using mitomycin C-treated 3T3 cells as a feeder layer.

Howard P. Baden; Joseph Kubilus; Joseph C. Kvedar; Mark L. Steinberg; Sandra R. Wolman

1987-01-01

335

Administration of growth factors for bone regeneration.  

PubMed

Growth factors (GFs) such as BMPs, FGFs, VEGFs and IGFs have significant impacts on osteoblast behavior, and thus have been widely utilized for bone tissue regeneration. Recently, securing biological stability for a sustainable and controllable release to the target tissue has been a challenge to practical applications. This challenge has been addressed to some degree with the development of appropriate carrier materials and delivery systems. This review highlights the importance and roles of those GFs, as well as their proper administration for targeting bone regeneration. Additionally, the in vitro and in vivo performance of those GFs with or without the use of carrier systems in the repair and regeneration of bone tissue is systematically addressed. Moreover, some recent advances in the utility of the GFs, such as using fusion technology, are also reviewed. PMID:22594329

Yun, Ye-Rang; Jang, Jun Hyeog; Jeon, Eunyi; Kang, Wonmo; Lee, Sujin; Won, Jong-Eun; Kim, Hae Won; Wall, Ivan

2012-05-01

336

Systems Biology of Vascular Endothelial Growth Factors  

PubMed Central

Several cytokine families have roles in development, maintenance and remodeling of the microcirculation. Of these, the VEGF family is one of the best studied and one of the most complex. Five VEGF ligand genes and five cell surface receptor genes are known in the human, and each of these may be transcribed as multiple splice isoforms to generate an extensive family of proteins, many of which are subject to further proteolytic processing. Using the VEGF family as an example, we describe the current knowledge of growth factor expression, processing and transport in vivo. Experimental studies and computational simulations are being used to measure and predict the activity of these molecules, and we describe avenues of research that seek to fill the remaining gaps in our understanding of VEGF family behavior.

Mac Gabhann, Feilim; Popel, Aleksander S.

2009-01-01

337

Matrix control of transforming growth factor-? function  

PubMed Central

The cytokine transforming growth factor-beta (TGF-?) has multiple effects in both physiological and pathological conditions. TGF-? is secreted as part of a tripartite complex from which it must be released in order to bind to its receptor. Sequestration of latent TGF-? in the extracellular matrix (ECM) is crucial for proper mobilization of the latent cytokine and its activation. However, contrary to expectation, loss-of-function mutations in genes encoding certain matrix proteins that bind TGF-? yield elevated, rather than decreased, TGF-? levels, posing a ‘TGF-? paradox.’ In this review, we discuss recent findings concerning the relationship of TGF-?, ECM molecules, and latent TGF-? activation and propose a model to resolve the ‘TGF-? paradox.’

Horiguchi, Masahito; Ota, Mitsuhiko; Rifkin, Daniel B.

2012-01-01

338

Growth hormone, insulinlike growth factor-1, and insulinlike growth factor binding proteins 1 and 3 in chronic liver disease  

Microsoft Academic Search

The liver is the major source of circulating insulinlike growth factor-I (IGF-I) and has been suggested as a major source of at least two of the major binding proteins that modify its bioavailability. We aimed to assess the direct effects of liver dysfunction on serum levels of IGF1 and its major binding proteins by measuring fasting levels of growth hormone,

Anthony Donaghy; Richard Ross; Alexander Gimson; Sian Cwyfan Hughes; Jeffrey Holly; Roger Williams

1995-01-01

339

Growth Regulation in Scleroderma Fibroblasts: Increased Response to Transforming Growth Factor-?1  

Microsoft Academic Search

We investigated the responses of normal and scleroderma fibroblasts to various growth Factors, especially transforming growth factor-?1 (TGF-?1). The effects of various growth Factors on [3H]thymidine incorporation in normal and scleroderma fibroblasts were examined. [125KI]-labeled platelet-derived growth factor (PDGF)-BB binding in scleroderma and normal fibroblasts was examined both in the presence and absence of TGF-?1 (1 ng\\/ml). Cytoplasmic protein was

Kanako Kikuchi; Takafumi Kadono; Hironobu Ihn; Shinichi Sato; Atsuyuki Igarashi; Hidemi Nakagawa; Kunihiko Tamaki; Kazuhiko Takehara

1995-01-01

340

Attenuation of the Transforming Growth Factor ? -Signaling Pathway in Chronic Venous Ulcers  

PubMed Central

Transforming growth factor ? (TGF?) is important in inflammation, angiogenesis, reepithelialization and connective tissue regeneration during wound healing. We analyzed components of TGF? signaling pathway in biopsies from 10 patients with nonhealing venous ulcers (VUs). Using comparative genomics of transcriptional profiles of VUs and TGF?-treated keratinocytes, we found deregulation of TGF? target genes in VUs. Using quantitative polymerase chain reaction (qPCR) and immunohistochemical analysis, we found suppression of TGF? RI, TGF? RII and TGF? RIII, and complete absence of phosphorylated Smad2 (pSmad2) in VU epidermis. In contrast, pSmad2 was induced in the cells of the migrating epithelial tongue of acute wounds. TGF?-inducible transcription factors (GADD45? , ATF3 and ZFP36L1) were suppressed in VUs. Likewise, genes suppressed by TGF? (FABP5, CSTA and S100A8) were induced in nonhealing VUs. An inhibitor of Smad signaling, Smad7 was also downregulated in VUs. We conclude that TGF? signaling is functionally blocked in VUs by downregulation of TGF? receptors and attenuation of Smad signaling resulting in deregulation of TGF? target genes and consequent hyperproliferation. These data suggest that application of exogenous TGF? may not be a beneficial treatment for VUs.

Pastar, Irena; Stojadinovic, Olivera; Krzyzanowska, Agata; Barrientos, Stephan; Stuelten, Christina; Zimmerman, Karen; Blumenberg, Miroslav; Brem, Harold; Tomic-Canic, Marjana

2010-01-01

341

Attenuation of the transforming growth factor beta-signaling pathway in chronic venous ulcers.  

PubMed

Transforming growth factor beta (TGFbeta) is important in inflammation, angiogenesis, reepithelialization and connective tissue regeneration during wound healing. We analyzed components of TGFbeta signaling pathway in biopsies from 10 patients with nonhealing venous ulcers (VUs). Using comparative genomics of transcriptional profiles of VUs and TGFbeta-treated keratinocytes, we found deregulation of TGFbeta target genes in VUs. Using quantitative polymerase chain reaction (qPCR) and immunohistochemical analysis, we found suppression of TGFbeta RI, TGFbeta RII and TGFbeta RIII, and complete absence of phosphorylated Smad2 (pSmad2) in VU epidermis. In contrast, pSmad2 was induced in the cells of the migrating epithelial tongue of acute wounds. TGFbeta-inducible transcription factors (GADD45beta , ATF3 and ZFP36L1) were suppressed in VUs. Likewise, genes suppressed by TGFbeta (FABP5, CSTA and S100A8) were induced in nonhealing VUs. An inhibitor of Smad signaling, Smad7 was also downregulated in VUs. We conclude that TGFbeta signaling is functionally blocked in VUs by downregulation of TGFbeta receptors and attenuation of Smad signaling resulting in deregulation of TGFbeta target genes and consequent hyperproliferation. These data suggest that application of exogenous TGFbeta may not be a beneficial treatment for VUs. PMID:20069132

Pastar, Irena; Stojadinovic, Olivera; Krzyzanowska, Agata; Barrientos, Stephan; Stuelten, Christina; Zimmerman, Karen; Blumenberg, Miroslav; Brem, Harold; Tomic-Canic, Marjana

2010-01-06

342

The role of the tetraspanin CD151 in primary keratinocyte and fibroblast functions: Implications for wound healing  

SciTech Connect

Previous studies showed that CD151-null mice have a skin wound healing deficit. To gain an understanding of the role of CD151 in re-epithelialisation and dermal contraction, keratinocyte and fibroblast functions were assayed. Primary CD151-null keratinocytes displayed defective migration on Matrigel (a basement membrane equivalent) and laminin-332, the primary adhesion component of basement membranes, but not on collagen-I. Adhesion, spreading and proliferation were also deficient on laminin-332, but not collagen-I. The data suggest that loss of CD151 impairs the function of its primary interaction partners, integrin {alpha}3{beta}1- and/or {alpha}6{beta}4 which bind to laminin-332. Skin fibroblasts also produce CD151 mRNA. CD151-null fibroblasts migrated significantly faster on collagen I than wild type fibroblasts, confirming that they possess functional collagen receptors. However, no significant decrease in the ability of CD151-null fibroblasts to cause contraction in floating collagen gel assays in response to transforming growth factor beta-1 (TGF-{beta}1) or platelet derived growth factor (PDGF-BB) was observed, nor was there an effect on fibroblast adhesion or proliferation on collagen-I. The data implicate CD151 as a facilitator of laminin-332-mediated keratinocyte functions that impact on the re-epithelialisation process intrinsic to wound healing and further suggest a potential novel role for CD151 in fibroblast migration.

Geary, Sean M. [School of Biomedical Sciences, University of Newcastle, New South Wales (Australia); Hunter Medical Research Institute, Newcastle, New South Wales (Australia); Cowin, Allison J. [Child Health Research Institute, North Adelaide, South Australia (Australia); Department of Paediatrics, University of Adelaide, South Australia (Australia); Copeland, Ben; Baleato, Rosa M. [School of Biomedical Sciences, University of Newcastle, New South Wales (Australia); Hunter Medical Research Institute, Newcastle, New South Wales (Australia); Miyazaki, Kaoru [Division of Cell Biology, Kihara Institute for Biological Research, Yokohama City University, Yokohama (Japan); Ashman, Leonie K. [School of Biomedical Sciences, University of Newcastle, New South Wales (Australia); Hunter Medical Research Institute, Newcastle, New South Wales (Australia)], E-mail: leonie.ashman@newcastle.edu.au

2008-07-01

343

Staphylococcus aureus Infection of Epidermal Keratinocytes Promotes Expression of Innate Antimicrobial Peptides  

Microsoft Academic Search

Received 21 October 2004\\/Returned for modification 26 January 2005\\/Accepted 5 April 2005 Keratinocytes upregulate expression of endogenous antimicrobial peptides in response to inflammatory stimuli. We show that both viable and heat-inactivated Staphylococcus aureus and lipoteichoic acid differentially alter expression of these peptides upon contact with human keratinocytes. The findings indicate a diversity of staphylococcal factors involved in upregulation of antimicrobial

Barbara E. Menzies; Aimee Kenoyer

2005-01-01

344

MicroRNA-21 is an important downstream component of BMP signalling in epidermal keratinocytes.  

PubMed

Bone morphogenetic proteins (BMPs) play essential roles in the control of skin development, postnatal tissue remodelling and tumorigenesis. To explore whether some of the effects of BMP signalling are mediated by microRNAs, we performed genome-wide microRNA (miRNA) screening in primary mouse keratinocytes after BMP4 treatment. Microarray analysis revealed substantial BMP4-dependent changes in the expression of distinct miRNAs, including miR-21. Real-time PCR confirmed that BMP4 dramatically inhibits miR-21 expression in the keratinocytes. Consistently, significantly increased levels of miR-21 were observed in transgenic mice overexpressing the BMP antagonist noggin under control of the K14 promoter (K14-noggin). By in situ hybridization, miR-21 expression was observed in the epidermis and hair follicle epithelium in normal mouse skin. In K14-noggin skin, miR-21 was prominently expressed in the epidermis, as well as in the peripheral portion of trichofolliculoma-like hair follicle-derived tumours that contain proliferating and poorly differentiated cells. By transfecting keratinocytes with a miR-21 mimic, we identified the existence of two groups of the BMP target genes, which are differentially regulated by miR-21. These included selected BMP-dependent tumour-suppressor genes (Pten, Pdcd4, Timp3 and Tpm1) negatively regulated by miR-21, as well as miR-21-independent Id1, Id2, Id3 and Msx2 that predominantly mediate the effects of BMPs on cell differentiation. In primary keratinocytes and HaCaT cells, miR-21 prevented the inhibitory effects of BMP4 on cell proliferation and migration. Thus, our study establishes a novel mechanism for the regulation of BMP-induced effects in the skin and suggests miRNAs are important modulators of the effects of growth factor signalling pathways on skin development and tumorigenesis. PMID:21984808

Ahmed, Mohammed I; Mardaryev, Andrei N; Lewis, Christopher J; Sharov, Andrey A; Botchkareva, Natalia V

2011-10-07

345

Keratinocyte galvanotaxis in combined DC and AC electric fields supports an electromechanical transduction sensing mechanism.  

PubMed

Sedentary keratinocytes at the edge of a skin wound migrate into the wound, guided by the generation of an endogenous electric field (EF) generated by the collapse of the transepithelial potential. The center of the wound quickly becomes more negative than the surrounding tissue and remains the cathode of the endogenous EF until the wound is completely re-epithelialized. This endogenous guidance cue can be studied in vitro. When placed in a direct current (DC) EF of physiological strength, 100 V/m, keratinocytes migrate directionally toward the cathode in a process known as galvanotaxis. Although a number of membrane-bound (e.g., epidermal growth factor receptor (EGFR), integrins) and cytosolic proteins (cAMP, ERK, PI3K) are known to play a role in the downstream signaling mechanisms underpinning galvanotaxis, the initial sensing mechanism for this response is not understood. To investigate the EF sensor, we studied the migration of keratinocytes in a DC EF of 100 V/m, alternating current (AC) EFs of 40 V/m at either 1.6 or 160 Hz, and combinations of DC and AC EFs. In the AC EFs alone, keratinocytes migrated randomly. The 1.6 Hz AC EF combined with the DC EF suppressed the direction of migration but had no effect on speed. In contrast, the 160 Hz AC EF combined with the DC EF did not affect the direction of migration but increased the migration speed compared to the DC EF alone. These results can be understood in terms of an electromechanical transduction model, but not an electrodiffusion/osmosis or a voltage-gated channel model. PMID:22907479

Hart, Francis X; Laird, Mhairi; Riding, Aimie; Pullar, Christine E

2012-08-21

346

Modifying muscular dystrophy through transforming growth factor-?.  

PubMed

Muscular dystrophy arises from ongoing muscle degeneration and insufficient regeneration. This imbalance leads to loss of muscle, with replacement by scar or fibrotic tissue, resulting in muscle weakness and, eventually, loss of muscle function. Human muscular dystrophy is characterized by a wide range of disease severity, even when the same genetic mutation is present. This variability implies that other factors, both genetic and environmental, modify the disease outcome. There has been an ongoing effort to define the genetic and molecular bases that influence muscular dystrophy onset and progression. Modifier genes for muscle disease have been identified through both candidate gene approaches and genome-wide surveys. Multiple lines of experimental evidence have now converged on the transforming growth factor-? (TGF-?) pathway as a modifier for muscular dystrophy. TGF-? signaling is upregulated in dystrophic muscle as a result of a destabilized plasma membrane and/or an altered extracellular matrix. Given the important biological role of the TGF-? pathway, and its role beyond muscle homeostasis, we review modifier genes that alter the TGF-? pathway and approaches to modulate TGF-? activity to ameliorate muscle disease. PMID:23551962

Ceco, Ermelinda; McNally, Elizabeth M

2013-04-24

347

Protection Against Mucosal Injury By Growth Factors and Cytokines  

Microsoft Academic Search

This article provides an overview of published studies in which growth factors and cytokines were used to modify the sensitivity of intestinal stem cells to a dose of radiation. In these experiments, growth factors were used to manipulate the sensitivity of stem cells in the gastrointestinal tract to reduce the severity of gastrointestinal mucositis in cancer therapy patients. Transforming growth

Dawn Booth; Christopher S. Potten

348

Endorsement of Growth Factors in Experiential Training Groups  

ERIC Educational Resources Information Center

|The purpose of this study was to identify student growth factors during a semester long Master's level group counseling class. Results indicated that 12 growth factors accounted for 86% of the total number of critical incidents that participants reported as influencing their personal growth and awareness during the group experience. Two other…

Kiweewa, John; Gilbride, Dennis; Luke, Melissa; Seward, Derek

2013-01-01

349

Opioid growth factor - opioid growth factor receptor axis inhibits proliferation of triple negative breast cancer.  

PubMed

Triple negative breast cancer (TNBC) represents approximately 15% of the newly diagnosed cancers worldwide and is characterized by tissue lacking in estrogen, progesterone and human epidermal growth factor receptors. TNBC disproportionately affects younger women and women of colour, and new treatments are needed. The opioid growth factor (OGF) - opioid growth factor receptor (OGFr) axis is a determinant of cell proliferation in neoplasia, and OGF is an endogenously produced pentapeptide that inhibits cell replication by interacting with OGFr and upregulating cyclin-dependent inhibitory kinase pathways thus reducing DNA synthesis. In these studies we investigated the presence and function of the OGF-OGFr axis in two human TNBC cell lines, as well as in breast cancer cell lines containing hormonal receptors. TNBC cell lines MDA-MD-231 and BT-20, as well as human breast cancer cells SK-BR-3 and MCF-7, were examined for the presence of pentapeptide and receptors, as well as their response to OGF. Specificity of peptide and receptor was confirmed by antibody neutralization and molecular studies to knockdown classical receptor protein. The requirement for protein transcription and translation and RNA transcription were investigated. Growth of TNBC cells in the presence of OGF and standard of care chemotherapeutic agent paclitaxel was evaluated to determine both efficacy and protective effects against toxicity. OGF treatment inhibited TNBC cells in a dosage related, receptor mediated, and reversible manner. OGF was the specific endogenous opioid to inhibit cell proliferation, and this was mediated by p21 cyclin dependent inhibitory kinase pathways, and required protein and RNA synthesis. OGFr was the specific receptor involved; both peptide and receptor were detected in all four cell lines. OGF treatment inhibited growth of all cancer cell lines evaluated, and reduced cell death in cultures exposed to paclitaxel. The OGF-OGFr axis is present and functioning in TNBC cell lines, and provides a novel biological pathway as potential therapy. PMID:23918871

Zagon, Ian S; Porterfield, Nancy K; McLaughlin, Patricia J

2013-06-01

350

Characterization of the Response of Human Umbilical Vein Endothelial Cells to Fibroblast Growth Factor, Epidermal Growth Factor, and Thrombin  

Microsoft Academic Search

Because the response of human endothelial cells to growth factors and condition- ing agents has broad implications for our understanding of wound healing, angiogenesis, and human atherogenesis, we have investigated the responses of these cells to the fibroblast (FGF) and epidermal growth factors (EGF), as well as to the protease thrombin, which has been previously shown to potentiate the growth

DENIS GOSPODAROWICZ; KENNETH D. BROWN; CHARLES R. BIRDWELL; BRUCE R. ZETTER

351

Fibroblast Growth Factors Are Required for Efficient Tumor Angiogenesis1  

Microsoft Academic Search

Although the function of vascular endothelial growth factor in the induction of tumor angiogenesis is well understood, the role of a second group of angiogenic factors, the fibroblast growth factors (FGFs), remains elusive. We used a recombinant adenovirus expressing soluble FGF re- ceptor (AdsFGFR) to interfere with FGF function in tumor angiogenesis. AdsFGFR repressed endothelial cell proliferation in vitro and

Amelia Compagni; Petra Wilgenbus; Maria-Antonietta Impagnatiello; Matt Cotten; Gerhard Christofori

352

Epidermal Growth Factor Receptor Dynamics Influences Response to Epidermal Growth Factor Receptor Targeted Agents  

Microsoft Academic Search

Analysis of gene expression of cancer cell lines exposed to erlotinib, a small molecule inhibitor of the epidermal growth factor receptor (EGFR), showed a marked increase in EGFR mRNA in resistant cell lines but not in susceptible ones. Because cetuximab induces EGFR down-regulation, we explored the hypothesis that treatment with cetuximab would interfere with erlotinib-induced EGFR up-regulation and result in

Antonio Jimeno; Maria L. Amador; Nadia Bouraoud; Peter Kulesza; Anirban Maitra; Manuel Hidalgo

2005-01-01

353

Pigment-independent cAMP-mediated epidermal thickening protects against cutaneous UV injury by keratinocyte proliferation.  

PubMed

The epidermis increases pigmentation and epidermal thickness in response to ultraviolet exposure to protect against UV-associated carcinogenesis; however, the contribution of epidermal thickness has been debated. In a humanized skin mouse model that maintains interfollicular epidermal melanocytes, we found that forskolin, a small molecule that directly activates adenylyl cyclase and promotes cAMP generation, up-regulated epidermal eumelanin accumulation in fair-skinned melanocortin-1-receptor (Mc1r)-defective animals. Forskolin-induced pigmentation was associated with a reproducible expansion of epidermal thickness irrespective of melanization or the presence of epidermal melanocytes. Rather, forskolin-enhanced epidermal thickening was mediated through increased keratinocyte proliferation, indirectly through secreted factor(s) from cutaneous fibroblasts. We identified keratinocyte growth factor (Kgf) as a forskolin-induced fibroblast-derived cytokine that promoted keratinocyte proliferation, as forskolin induced Kgf expression both in the skin and in primary fibroblasts. Lastly, we found that even in the absence of pigmentation, forskolin-induced epidermal thickening significantly diminished the amount of UV-A and UV-B that passed through whole skin and reduced the amount of UV-B-associated epidermal sunburn cells. These findings suggest the possibility of pharmacologic-induced epidermal thickening as a novel UV-protective therapeutic intervention, particularly for individuals with defects in pigmentation and adaptive melanization. PMID:23078399

Scott, Timothy L; Christian, Perry A; Kesler, Melissa V; Donohue, Kevin M; Shelton, Brent; Wakamatsu, Kazumasa; Ito, Shosuke; D'Orazio, John

2012-10-01

354

Pigment-independent cAMP-mediated epidermal thickening protects against cutaneous UV injury by keratinocyte proliferation  

PubMed Central

The epidermis increases pigmentation and epidermal thickness in response to ultraviolet exposure to protect against UV-associated carcinogenesis; however, the contribution of epidermal thickness has been debated. In a humanized skin mouse model that maintains interfollicular epidermal melanocytes, we found that forskolin, a small molecule that directly activates adenylyl cyclase and promotes cAMP generation, up-regulated epidermal eumelanin accumulation in fair-skinned melanocortin-1-receptor (Mc1r)-defective animals. Forskolin-induced pigmentation was associated with a reproducible expansion of epidermal thickness irrespective of melanization or the presence of epidermal melanocytes. Rather, forskolin-enhanced epidermal thickening was mediated through increased keratinocyte proliferation, indirectly through secreted factor(s) from cutaneous fibroblasts. We identified keratinocyte growth factor (Kgf) as a forskolin-induced fibroblast-derived cytokine that promoted keratinocyte proliferation, as forskolin induced Kgf expression both in the skin and in primary fibroblasts. Lastly, we found that even in the absence of pigmentation, forskolin-induced epidermal thickening significantly diminished the amount of UVA and UVB that passed through whole skin and reduced the amount of UVB-associated epidermal sunburn cells. These findings suggest the possibility of pharmacologic-induced epidermal thickening as a novel UV-protective therapeutic intervention, particularly for individuals with defects in pigmentation and adaptive melanization.

Scott, Timothy L.; Christian, P.A.; Kesler, M.; Donohue, Kevin M.; Shelton, Brent; Wakamatsu, Kazumasa; Ito, Shosuke; D'Orazio, John

2012-01-01

355

Agent Based Modelling Helps in Understanding the Rules by Which Fibroblasts Support Keratinocyte Colony Formation  

PubMed Central

Background Autologous keratincoytes are routinely expanded using irradiated mouse fibroblasts and bovine serum for clinical use. With growing concerns about the safety of these xenobiotic materials, it is desirable to culture keratinocytes in media without animal derived products. An improved understanding of epithelial/mesenchymal interactions could assist in this. Methodology/Principal Findings A keratincyte/fibroblast o-culture model was developed by extending an agent-based keratinocyte colony formation model to include the response of keratinocytes to both fibroblasts and serum. The model was validated by comparison of the in virtuo and in vitro multicellular behaviour of keratinocytes and fibroblasts in single and co-culture in Greens medium. To test the robustness of the model, several properties of the fibroblasts were changed to investigate their influence on the multicellular morphogenesis of keratinocyes and fibroblasts. The model was then used to generate hypotheses to explore the interactions of both proliferative and growth arrested fibroblasts with keratinocytes. The key predictions arising from the model which were confirmed by in vitro experiments were that 1) the ratio of fibroblasts to keratinocytes would critically influence keratinocyte colony expansion, 2) this ratio needed to be optimum at the beginning of the co-culture, 3) proliferative fibroblasts would be more effective than irradiated cells in expanding keratinocytes and 4) in the presence of an adequate number of fibroblasts, keratinocyte expansion would be independent of serum. Conclusions A closely associated computational and biological approach is a powerful tool for understanding complex biological systems such as the interactions between keratinocytes and fibroblasts. The key outcome of this study is the finding that the early addition of a critical ratio of proliferative fibroblasts can give rapid keratinocyte expansion without the use of irradiated mouse fibroblasts and bovine serum.

Sun, Tao; McMinn, Phil; Holcombe, Mike; Smallwood, Rod; MacNeil, Sheila

2008-01-01

356

Growth/differentiation factor-11: an evolutionary conserved growth factor in vertebrates.  

PubMed

Growth and differentiation factor-11 (GDF-11) is a member of the transforming growth factor-? superfamily and is thought to be derived together with myostatin (known also as GDF-8) from an ancestral gene. In the present study, we report the isolation and characterization of GDF-11 homolog from a marine teleost, the gilthead sea bream Sparus aurata, and show that this growth factor is highly conserved throughout vertebrates. Using bioinformatics, we identified GDF-11 in Tetraodon, Takifugu, medaka, and stickleback and found that they are highly conserved at the amino acid sequence as well as gene organization. Moreover, we found conservation of syntenic relationships among vertebrates in the GDF-11 locus. Transcripts for GDF-11 can be found in eggs and early embryos, albeit at low levels, while in post-hatching larvae expression levels are high and decreases as development progresses, suggesting that GDF-11 might have a role during early development of fish as found in tetrapods and zebrafish. Finally, GDF-11 is expressed in various tissues in the adult fish including muscle, brain, and eye. PMID:20694476

Funkenstein, Bruria; Olekh, Elena

2010-08-07

357

A case of pulmonary papillary adenoma: possible relationship between tumor histogenesis/tumorigenesis and fibroblast growth factor receptor 2 IIIb.  

PubMed

Pulmonary papillary adenoma is a rare tumor. We analyzed a tumor which appeared in a 16-year-old Japanese woman. The tumor histologically showed papillary proliferation of one-layered tumor cells coating inflammatory fibrovascular cores. At the periphery of the tumor, the tumor cells grew in a lepidic fashion. The tumor cells were confirmed as type-II pneumocytes with electron-microscope. In this study, using immunohistochemistry, in situ hybridization and real-time reverse transcription polymerase chain reaction, we examined the expressions and quantities of fibroblast growth factor 10 (FGF10), keratinocyte growth factor (KGF) and fibroblast growth factor receptor 2 (FGFR2) IIIb, based on the extent of their abilities of proliferation and differentiation of type II pneumocytes. The tumor cells expressed FGFR 2 and produced 350 times more FGFR2IIIb messenger RNA (mRNA) than did the nontumorous lung. The quantity of KGF mRNA in the tumor tissue was twice that of the nontumorous lung. Moreover, there was dysregulation of FGFR2IIIb transcription in the tumor. According to these findings, we expect overexpression of FGFR2IIIb to play an important role in causing tumor. Because FGFR is suspected to be connected with lung carcinoma, we also treat similar tumorigenesis via FGFR as carcinoma; complete resection of adenoma might be indicated. PMID:22924850

Masunaga, Atsuko; Nagashio, Ryo; Iwamoto, Sanju; Takeyama, Nobuyuki; Sato, Yuichi; Miyazaki, Akira; Mitsuya, Toshiyuki

2012-07-17

358

Fibroblast Growth Factor Control of Cartilage Homeostasis  

PubMed Central

Osteoarthritis (OA) and degenerative disc disease (DDD) are similar diseases involving the breakdown of cartilage tissue, and a better understanding of the underlying biochemical processes involved in cartilage degeneration may allow for the development of novel biologic therapies aimed at slowing the disease process. Three members of the fibroblast growth factor (FGF) family, FGF-2, FGF-18, and FGF-8, have been implicated as contributing factors in cartilage homeostasis. The role of FGF-2 is controversial in both articular and intervertebral disc (IVD) cartilage as it has been associated with species- and age-dependent anabolic or catabolic events. Recent evidence suggests that FGF-2 selectively activates FGF receptor 1 (FGFR1) to exert catabolic effects in human articular chondrocytes and IVD tissue via upregulation of matrix-degrading enzyme production, inhibition of extracellular matrix (ECM) accumulation and proteoglycan synthesis, and clustering of cells characteristic of arthritic states. FGF-18, on the other hand, most likely exerts anabolic effects in human articular chondrocytes by activating the FGFR3 pathway, inducing ECM formation and chondrogenic cell differentiation, and inhibiting cell proliferation. These changes result in dispersed chondrocytes or disc cells surrounded by abundant matrix. The role of FGF-8 has recently been identified as a catabolic mediator in rat and rabbit articular cartilage, but its precise biological impact on human adult articular cartilage or IVD tissue remains unknown. The available evidence reveals the promise of FGF-2/FGFR1 antagonists, FGF-18/FGFR3 agonists, and FGF-8 antagonists (i.e., anti-FGF-8 antibody) as potential therapies to prevent cartilage degeneration and/or promote cartilage regeneration and repair in the future.

Ellman, M.B.; Yan, D.; Ahmadinia, K.; Chen, D.; An, H.S.; Im, H.J.

2013-01-01

359

Fibroblast growth factor control of cartilage homeostasis.  

PubMed

Osteoarthritis (OA) and degenerative disc disease (DDD) are similar diseases involving the breakdown of cartilage tissue, and a better understanding of the underlying biochemical processes involved in cartilage degeneration may allow for the development of novel biologic therapies aimed at slowing the disease process. Three members of the fibroblast growth factor (FGF) family, FGF-2, FGF-18, and FGF-8, have been implicated as contributing factors in cartilage homeostasis. The role of FGF-2 is controversial in both articular and intervertebral disc (IVD) cartilage as it has been associated with species- and age-dependent anabolic or catabolic events. Recent evidence suggests that FGF-2 selectively activates FGF receptor 1 (FGFR1) to exert catabolic effects in human articular chondrocytes and IVD tissue via upregulation of matrix-degrading enzyme production, inhibition of extracellular matrix (ECM) accumulation and proteoglycan synthesis, and clustering of cells characteristic of arthritic states. FGF-18, on the other hand, most likely exerts anabolic effects in human articular chondrocytes by activating the FGFR3 pathway, inducing ECM formation and chondrogenic cell differentiation, and inhibiting cell proliferation. These changes result in dispersed chondrocytes or disc cells surrounded by abundant matrix. The role of FGF-8 has recently been identified as a catabolic mediator in rat and rabbit articular cartilage, but its precise biological impact on human adult articular cartilage or IVD tissue remains unknown. The available evidence reveals the promise of FGF-2/FGFR1 antagonists, FGF-18/FGFR3 agonists, and FGF-8 antagonists (i.e., anti-FGF-8 antibody) as potential therapies to prevent cartilage degeneration and/or promote cartilage regeneration and repair in the future. PMID:23060229

Ellman, M B; Yan, D; Ahmadinia, K; Chen, D; An, H S; Im, H J

2013-04-01

360

Transcriptional activation of cathepsin D gene expression by growth factors  

Microsoft Academic Search

Insulin-like growth factor-I (IGF-I), transforming growth factor (TGF) and epidermal growth factor (EGF) induced cathepsin D gene expression and reporter gene activity in MCF-7 human breast cancer cells transiently transfected with a construct (pCD1) containing a 2576 to 124 cathepsin D gene promoter insert. In contrast, IGF-I, but not TGF or EGF, induced reporter gene activity in cells cotransfected with

F Wang; R Duan; J Chirgwin; S H Safe

2000-01-01

361

Growth Factors, Apoptosis, and Survival of Mammary Epithelial Cells  

Microsoft Academic Search

Programmed cell death (apoptosis) occursregularly during normal growth and development of themammary gland. One of the most dramatic examples ofapoptosis is evident during the remodeling of the breast that accompanies postlactational involution.Transgenic mouse models have demonstrated thatoverexpression of polypeptides such as transforminggrowth factor alpha (TGFa)3 and insulinlike growth factor I (IGF-I) can block this remodeling, suggestingthat these growth factors may

Edward C. Rosfjord; Robert B. Dickson

1999-01-01

362

Abnormal Growth Factor\\/Cytokine Network in Gastric Cancer  

Microsoft Academic Search

Gastric cancer cells express a broad spectrum of the growth factor\\/cytokine receptor systems that organize the complex interaction\\u000a between cancer cells and stromal cells in tumor microenvironment, which confers cell growth, apoptosis, morphogenesis, angiogenesis,\\u000a progression and metastasis. However, these abnormal growth factor\\/cytokine networks differ in the two histological types of\\u000a gastric cancer. Importantly, activation of nuclear factor-kB pathway by Helicobacter

Eiichi Tahara

2008-01-01

363

Stem cell factor, a novel cutaneous growth factor for mast cells and melanocytes  

Microsoft Academic Search

Mechanisms affecting mast cell and melanocyte growth and function are still poorly understood. This report summarizes the current state of knowledge on a recently described growth factor for both these cell types and for primitive haematopoietic stem cells. Stem cell factor (SCF), also named mast cell growth factor or kit-ligand, has only recently been cloned and has been shown to

J. Grabbe; P. Welker; E. Dippel; B. M. Czarnetzki

1994-01-01

364

Nerve growth factor actions on the brain  

SciTech Connect

We examined the effect of the trophic protein, nerve growth factor (NGF), on cultures of fetal rat neostriatum and basal forebrain-medial septal area (BF-MS) to define its role in brain development. Treatment of cultures with NGF resulted in an increase in the specific activity of the cholinergic enzyme choline acetyltransferase (CAT) in both brain areas. CAT was immunocytochemically localized to neurons. In the BF-MS, NGF treatment elicited a marked increase in staining intensity and an apparent increase in the number of CAT-positive neurons. Moreover, treatment of BF-MS cultures with NGF increased the activity of acetylcholinesterase, suggesting that the cholinergic neuron as a whole was affected. To begin defining mechanisms of action of NGF in the BF-MS, we detected NGF receptors by two independent methods. Receptors were localized to two different cellular populations: neuron-like cells, and non-neuron-like cells. Dissociation studies with ({sup 125}I)NGF suggested that high affinity receptors were localized to the neuron-like population. Only low-affinity receptors were localized to the non-neuron-like cells. Moreover, employing combined immunocytochemistry and ({sup 125}I)NGF autoradiography, we detected a subpopulation of CAT-containing neutrons that exhibited high-affinity binding. Unexpectedly, a gamma-aminobutyric acid (GABA)-containing cell group also expressed high affinity binding. However, only subsets of cholinergic or GABA neurons expressed high-affinity biding, suggesting that these transmitter populations are composed of differentially response subpopulations.

Martinez, H.J.

1989-01-01

365

Epidermal growth factor receptors in the oesophagus.  

PubMed Central

The quantity and distribution of epidermal growth factor receptors (EGF-R) in oesophageal mucosa was studied in the oesophagus in order to determine its role in oesophageal disease. Fifty five biopsies were taken from different levels of the oesophagus in 25 consecutive patients undergoing endoscopy. Another group of eight patients with histologically proven Barrett's oesophagitis had a biopsy taken from the area of columnar lined oesophagus. A peripheral, membranous pattern was seen predominantly confined to the basal and immediately suprabasal cells in all of the first group of patients. In the superficial cells a few granular cytoplasmic structures were positive. All patients with Barrett's oesophagitis showed EGF-R staining of the surface epithelium. A computerised planimeter was used to determine the proportion of stained areas of squamous cells which were expressed as a percentage of the total area of squamous cells. The difference in the area of cells stained for EGF-R between normal and inflamed oesophageal mucosa (29.5% and 43.1% respectively) was significant (p less than 0.001). Images Figure 1

Jankowski, J; Murphy, S; Coghill, G; Grant, A; Wormsley, K G; Sanders, D S; Kerr, M; Hopwood, D

1992-01-01

366

Vascular Endothelial Growth Factor in Eye Disease  

PubMed Central

Collectively, angiogenic ocular conditions represent the leading cause of irreversible vision loss in developed countries. In the U.S., for example, retinopathy of prematurity, diabetic retinopathy and age-related macular degeneration are the principal causes of blindness in the infant, working age and elderly populations, respectively. Evidence suggests that vascular endothelial growth factor (VEGF), a 40 kDa dimeric glycoprotein, promotes angiogenesis in each of these conditions, making it a highly significant therapeutic target. However, VEGF is pleiotropic, affecting a broad spectrum of endothelial, neuronal and glial behaviors, and confounding the validity of anti-VEGF strategies, particularly under chronic disease conditions. In fact, among other functions VEGF can influence cell proliferation, cell migration, proteolysis, cell survival and vessel permeability in a wide variety of biological contexts. This article will describe the roles played by VEGF in the pathogenesis of retinopathy of prematurity, diabetic retinopathy and age-related macular degeneration. The potential disadvantages of inhibiting VEGF will be discussed, as will the rationales for targeting other VEGF-related modulators of angiogenesis.

Penn, J.S.; Madan, A.; Caldwell, R.B.; Bartoli, M.; Caldwell, R.W.; Hartnett, M.E.

2012-01-01

367

Epidermal growth factor receptors in the oesophagus.  

PubMed

The quantity and distribution of epidermal growth factor receptors (EGF-R) in oesophageal mucosa was studied in the oesophagus in order to determine its role in oesophageal disease. Fifty five biopsies were taken from different levels of the oesophagus in 25 consecutive patients undergoing endoscopy. Another group of eight patients with histologically proven Barrett's oesophagitis had a biopsy taken from the area of columnar lined oesophagus. A peripheral, membranous pattern was seen predominantly confined to the basal and immediately suprabasal cells in all of the first group of patients. In the superficial cells a few granular cytoplasmic structures were positive. All patients with Barrett's oesophagitis showed EGF-R staining of the surface epithelium. A computerised planimeter was used to determine the proportion of stained areas of squamous cells which were expressed as a percentage of the total area of squamous cells. The difference in the area of cells stained for EGF-R between normal and inflamed oesophageal mucosa (29.5% and 43.1% respectively) was significant (p less than 0.001). PMID:1582583

Jankowski, J; Murphy, S; Coghill, G; Grant, A; Wormsley, K G; Sanders, D S; Kerr, M; Hopwood, D

1992-04-01

368

Nerve growth factor: structure/function relationships.  

PubMed Central

Nerve growth factor (NGF), which has a tertiary structure based on a cluster of 3 cystine disulfides and 2 very extended, but distorted beta-hairpins, is the prototype of a larger family of neurotrophins. Prior to the availability of cloning techniques, the mouse submandibular gland was the richest source of NGF and provided sufficient material to enable its biochemical characterization. It binds as a dimer to at least 2 cell-surface receptor types expressed in a variety of neuronal and non-neuronal cells. Residues involved in these interactions and in the maintenance of tertiary and quaternary structure have been identified by chemical modification and site-directed mutagenesis, and this information can be related to their location in the 3-dimensional structure. For example, interactions between aromatic residues contribute to the stability of the NGF dimer, and specific surface lysine residues participate in receptor contacts. The conclusion from these studies is that receptor interactions involve broad surface regions, which may be composed of residues from both promoters in the dimer.

Bradshaw, R. A.; Murray-Rust, J.; Ibanez, C. F.; McDonald, N. Q.; Lapatto, R.; Blundell, T. L.

1994-01-01

369

Connective tissue growth factor in tumor pathogenesis  

PubMed Central

Key roles for connective tissue growth factor (CTGF/CCN2) are demonstrated in the wound repair process where it promotes myofibroblast differentiation and angiogenesis. Similar mechanisms are active in tumor-reactive stroma where CTGF is expressed. Other potential roles include prevention of hypoxia-induced apoptosis and promoting epithelial-mesenchymal transistion (EMT). CTGF expression in tumors has been associated to both tumor suppression and progression. For example, CTGF expression in acute lymphoblastic leukemia, breast, pancreas and gastric cancer correlates to worse prognosis whereas the opposite is true for colorectal, lung and ovarian cancer. This discrepancy is not yet understood. High expression of CTGF is a hallmark of ileal carcinoids, which are well-differentiated endocrine carcinomas with serotonin production originating from the small intestine and proximal colon. These tumors maintain a high grade of differentiation and low proliferation. Despite this, they are malignant and most patients have metastatic disease at diagnosis. These tumors demonstrate several phenotypes potentially related to CTGF function namely: cell migration, absent tumor cell apoptosis, as well as, reactive and well vascularised myofibroblast rich stroma and fibrosis development locally and in distal organs. The presence of CTGF in other endocrine tumors indicates a role in the progression of well-differentiated tumors.

2012-01-01

370

Heparin-Binding Epidermal-Growth-Factor-Like Growth Factor Activation of Keratinocyte ErbB Receptors Mediates Epidermal Hyperplasia, a Prominent Side-Effect of Retinoid Therapy  

Microsoft Academic Search

Sun-protected human skin was maintained in organ culture and treated with all-trans retinoic acid in the presence or absence of reversible or irreversible pharmacologic antagonists of c-erbB receptor tyrosine kinase activity. In the absence of these inhibitors, all-trans retinoic acid induced epidermal hyperplasia comparable to that induced in intact skin by all-trans retinol or all-trans retinoic acid itself. There was

James Varani; Mary Zeigler; Michael K. Dame; Sewon Kang; Gary J. Fisher; John J. Voorhees; Stefan W. Stoll; James T. Elder

2001-01-01

371

In vivo transfer and expression of a human epidermal growth factor gene accelerates wound repair.  

PubMed Central

This report details the transfer of a human epidermal growth factor (hEGF) expression plasmid to porcine partial-thickness wound keratinocytes by particle-mediated DNA transfer (Accell). After gene transfer an external sealed fluid-filled wound chamber was used to protect the wound, provide containment of the exogenous DNA and expressed peptide, and permit sampling of the wound fluid. Analysis of wound fluid for hEGF and total protein, an indicator of reformation of the epithelial barrier, showed that wounds bombarded with the hEGF plasmid exhibited a 190-fold increase in EGF concentration and healed 20% (2.1 days) earlier than the controls. EGF concentrations in wound fluid persisted over the entire 10-day monitored period, decreasing from 200 pg/ml to 25 pg/ml over the first 5 days. Polymerase chain reaction results showed that plasmid DNA was present in the wound for at least 30 days. These findings demonstrate the possible utility of in vivo gene transfer to enhance epidermal repair. Images

Andree, C; Swain, W F; Page, C P; Macklin, M D; Slama, J; Hatzis, D; Eriksson, E

1994-01-01

372

Expression of the E2F1 Transcription Factor Overcomes Type beta Transforming Growth Factor-Mediated Growth Suppression  

Microsoft Academic Search

Inhibition of cell growth by type beta transforming growth factor (TGF-beta) occurs in mid-G_1 and is associated with decreased G_1 cyclin-dependent kinase activity and maintenance of the retinoblastoma tumor suppressor protein Rb in an underphosphorylated, growth-suppressive state. A variety of recent experiments suggest that a functional target of Rb is the E2F transcription factor. In addition, the growth-suppressive effects of

James K. Schwarz; Craig H. Bassing; Imre Kovesdi; Michael B. Datto; Michael Blazing; Samuel George; Xiao-Fan Wang; Joseph R. Nevis

1995-01-01

373

Effect of Recombinant Human Keratinocyte Growth Factor (rHuKGF, Palifermin) on Radiation-Induced Mouse Urinary Bladder Dysfunction  

SciTech Connect

Purpose: To determine the effect of Palifermin (rHuKGF) on acute and late radiation effects in mouse urinary bladder. Methods and Materials: Graded radiation doses were applied on day 0. Single subcutaneous injections of Palifermin (15 mg/kg) were given on day -2 or day +2. Changes in bladder function (i.e., a reduction in bladder volume by {>=}50% of the individual preirradiation value) were assessed by cystometry. Results: Early changes in mouse bladder after irradiation occur in two phases. In the first early phase, a single injection of Palifermin on day -2 increased the ED{sub 50} (dose associated with a positive bladder response in 50% of the mice) from 20.0 {+-} 3.3 Gy to 27.1 {+-} 6.9 Gy (p < .0051). Palifermin given on day +2 was not beneficial. No significant effects of Palifermin were seen in the second early phase. However, Palifermin administration before, but not after, irradiation, also modified late radiation effects, with an ED{sub 50} of 22.2 {+-} 4.8 Gy compared with 16.2 {+-} 4.9 Gy in control animals (p < .0187). Conclusions: Initial early functional changes in the mouse urinary bladder after irradiation as well as late effects can be significantly reduced by a single administration of Palifermin before irradiation.

Jaal, Jana [Department of Radiotherapy and Radiation Oncology, University of Technology of Dresden, Dresden (Germany); Clinic of Hematology and Oncology, Tartu University Hospital (Estonia)], E-mail: Jana.Jaal@kliinikum.ee; Doerr, Wolfgang [Experimental Centre, Medical Faculty Carl Gustav Carus, University of Technology of Dresden, Dresden (Germany)

2007-10-01

374

Enhanced growth of small bowel in transgenic mice expressing human insulin-like growth factor I  

Microsoft Academic Search

BACKGROUND & AIMS: Growth hormone and insulin-like growth factor I (IGF- I) stimulate small bowel growth. The aim of this study was to analyze whether IGF-I mediates enterotrophic actions of growth hormone.METHODS: IGF-I transgenic mice that overexpress an IGF-I transgene driven by the mouse metallothionein I promoter and are growth hormone deficient were compared with wild-type littermates. Growth of small

K Ohneda; MH Ulshen; CR Fuller; AJ D'Ercole; PK Lund

1997-01-01

375

Human Keratinocytes Are Vanilloid Resistant  

PubMed Central

Background Use of capsaicin or resiniferatoxin (RTX) as analgesics is an attractive therapeutic option. RTX opens the cation channel inflammatory pain/vanilloid receptor type 1 (TRPV1) permanently and selectively removes nociceptive neurons by Ca2+-cytotoxicity. Paradoxically, not only nociceptors, but non-neuronal cells, including keratinocytes express full length TRPV1 mRNA, while patient dogs and experimental animals that underwent topical treatment or anatomically targeted molecular surgery have shown neither obvious behavioral, nor pathological side effects. Methods To address this paradox, we assessed the vanilloid sensitivity of the HaCaT human keratinocyte cell line and primary keratinocytes from skin biopsies. Results Although both cell types express TRPV1 mRNA, neither responded to vanilloids with Ca2+-cytotoxicity. Only ectopic overproduction of TRPV1 rendered HaCaT cells sensitive to low doses (1–50 nM) of vanilloids. The TRPV1-mediated and non-receptor specific Ca2+-cytotoxity ([RTX]>15 µM) could clearly be distinguished, thus keratinocytes were indeed resistant to vanilloid-induced, TRPV1-mediated Ca2+-entry. Having a wider therapeutic window than capsaicin, RTX was effective in subnanomolar range, but even micromolar concentrations could not kill human keratinocytes. Keratinocytes showed orders of magnitudes lower TRPV1 mRNA level than sensory ganglions, the bona fide therapeutic targets in human pain management. In addition to TRPV1, TRPV1b, a dominant negative splice variant was also noted in keratinocytes. Conclusion TRPV1B expression, together with low TRPV1 expression, may explain the vanilloid paradox: even genuinely TRPV1 mRNA positive cells can be spared with therapeutic (up to micromolar) doses of RTX. This additional safety information might be useful for planning future human clinical trials.

Pecze, Laszlo; Szabo, Kornelia; Szell, Marta; Josvay, Katalin; Kaszas, Krisztian; Kusz, Erzsebet; Letoha, Tamas; Prorok, Janos; Koncz, Istvan; Toth, Andras; Kemeny, Lajos; Vizler, Csaba; Olah, Zoltan

2008-01-01

376

Growth factor receptors as therapeutic targets: strategies to inhibit the insulin-like growth factor I receptor  

Microsoft Academic Search

Neoplastic transformation is often related to abnormal activation of growth factor receptors and their signaling pathways. The concept of targeting specific tumorigenic receptors and\\/or signaling molecules has been validated by the development and successful clinical application of drugs acting against the epidermal growth factor receptor 2 (HER2\\/neu, Erb2), the epidermal growth factor receptor 1 (EGFR, HER1), the Brc-Abl kinase, the

Eva Surmacz

2003-01-01

377

Actin filament dynamics impacts keratinocyte stem cell maintenance  

PubMed Central

Cultured human epidermal keratinocyte stem cells (holoclones) are crucial for regenerative medicine for burns and genetic disorders. In serial culture, holoclones progressively lose their proliferative capacity to become transient amplifying cells with limited growth (paraclones), a phenomenon termed clonal conversion. Although it negatively impacts the culture lifespan and the success of cell transplantation, little is known on the molecular mechanism underlying clonal conversion. Here, we show that holoclones and paraclones differ in their actin filament organization, with actin bundles distributed radially in holoclones and circumferentially in paraclones. Moreover, actin organization sets the stage for a differing response to epidermal growth factor (EGF), since EGF signalling induces a rapid expansion of colony size in holoclones and a significant reduction in paraclones. Furthermore, inhibition of PI3K or Rac1 in holoclones results in the reorganization of actin filaments in a pattern that is similar to that of paraclones. Importantly, continuous Rac1 inhibition in holoclones results in clonal conversion and reduction of growth potential. Together, our data connect loss of stem cells to EGF-induced colony dynamics governed by Rac1.

Nanba, Daisuke; Toki, Fujio; Matsushita, Natsuki; Matsushita, Sachi; Higashiyama, Shigeki; Barrandon, Yann

2013-01-01

378

Immunostimulatory activity of murine keratinocyte-derived exosomes.  

PubMed

It has long been known that keratinocytes influence cutaneous immunity through secretion of soluble factors. Exosomes, small membrane vesicles of endocytotic origin, have been implicated in intercellular communication processes such as the transfer of tumor cell antigens and the activation of recipient dendritic cells (DC). However, little is known about immunomodulatory functions of keratinocyte-derived exosomes. To address this question, we analysed exosome secretion of the murine keratinocyte cell line MPEK under steady state as well as inflammatory conditions (+/- IFN?). These exosomes were readily taken up by bone marrow-derived DC (BMDC) in vitro resulting in a matured phenotype, as evidenced by increased CD40 expression as well as by the production of large amounts of IL-6, IL-10 and IL-12. When the transfer of antigen-specific information through exosomes was investigated, it was found that keratinocytes took up antigen (ovalbumin) and transferred it to their exosomes. However, these antigen-harbouring exosomes failed to induce antigen-specific T cell responses via BMDC. Together, this novel biological function suggests that keratinocytes are able to direct unspecific immune processes but do not elicit specific immune responses. PMID:24079734

Kotzerke, Kristina; Mempel, Martin; Aung, Thiha; Wulf, Gerald G; Urlaub, Henning; Wenzel, Dirk; Schön, Michael P; Braun, Andrea

2013-10-01

379

Connective tissue growth factor is a new ligand of epidermal growth factor receptor.  

PubMed

Chronic kidney disease is reaching epidemic proportions worldwide and there is no effective treatment. Connective tissue growth factor (CCN2) has been suggested as a risk biomarker and a potential therapeutic target for renal diseases, but its specific receptor has not been identified. Epidermal growth factor receptor (EGFR) participates in kidney damage, but whether CCN2 activates the EGFR pathway is unknown. Here, we show that CCN2 is a novel EGFR ligand. CCN2 binding to EGFR extracellular domain was demonstrated by surface plasmon resonance. CCN2 contains four distinct structural modules. The carboxyl-terminal module (CCN2(IV)) showed a clear interaction with soluble EGFR, suggesting that EGFR-binding site is located in this module. Injection of CCN2(IV) in mice increased EGFR phosphorylation in the kidney, mainly in tubular epithelial cells. EGFR kinase inhibition decreased CCN2(IV)-induced renal changes (ERK activation and inflammation). Studies in cultured tubular epithelial cells showed that CCN2(IV) binds to EGFR leading to ERK activation and proinflammatory factors overexpression. CCN2 interacts with the neurotrophin receptor TrkA, and EGFR/TrkA receptor crosstalk was found in response to CCN2(IV) stimulation. Moreover, endogenous CCN2 blockade inhibited TGF-?-induced EGFR activation. These findings indicate that CCN2 is a novel EGFR ligand that contributes to renal damage through EGFR signalling. PMID:23929714

Rayego-Mateos, Sandra; Rodrigues-Díez, Raquel; Morgado-Pascual, Jose Luis; Rodrigues Díez, Raul R; Mas, Sebastian; Lavoz, Carolina; Alique, Matilde; Pato, Janos; Keri, Gyorgy; Ortiz, Alberto; Egido, Jesus; Ruiz-Ortega, Marta

2013-08-08

380

Epidermal growth factor and insulin-like growth factor-1 protect MDA231 cells from death induced by actinomycin D: The involvement of growth factors in drug resistance  

Microsoft Academic Search

Summary  In the present study, we investigated the ability of epidermal growth factor (EGF), insulin-like growth factor-1 (IGF-1),\\u000a and insulin to protect the human breast cancer cell line MDA-231 from death induced by the antitumor drug actinomycin D (ACT-D).\\u000a ACT-D is an inhibitor of RNA and protein synthesis, and its cytotoxicity may result due to continuous depletion in some vital\\u000a protein

Avraham Geier; Rina Hemi; Michal Haimsohn; Rachel Beery; Zvi Malik; Avraham Karasik

1994-01-01

381

Expression of epidermal growth factor, epidermal growth factor receptor and transforming growth factor-alpha in the human fetal inner ear  

Microsoft Academic Search

The expression of epidermal growth factor (EGF), EGF receptor and transforming growth factor (TGF)-alpha was analyzed in the human fetal inner ear using immuno-histochemical methods. EGF receptor was observed only in 9.5-week-old fetal vestibular epithelia. In 14- and 16-week-old fetuses, EGF receptor could not be detected. TGF-alpha was observed strongly in the 9- and 11-week-old vestibular epithelia, whereas only trace

H. Yamashita; M. Takahashi; D. Bagger-Sjöbäck

1996-01-01

382

Rapid Economic Growth: Contributing Factors and Challenges Ahead  

Microsoft Academic Search

The sustained improvement in the underlying conditions for growth for more than two decades has resulted in lifting the Indian economy from the bottom of the growth heap to one of the fastest growing economies in the world. This paper presents the factors that have contributed to the growth acceleration in India over the past 25 years and the challenges

Isher Judge AHLUWALIA

2008-01-01

383

PROBIOTICS: GROWTH-PROMOTING FACTORS PRODUCED BY MICROORGANISMS.  

PubMed

Several species of protozoa, during their logarithmic phases of growth, produce substances that prolong the logarithmic phase in other species. The effect is not as striking as the inhibition of growth caused by antibiotics, but a consistent 50-percent increase in growth has been obtained with Tetrahymena pyriformis in response to a factor produced by Colpidium campylum. PMID:14242024

LILLY, D M; STILLWELL, R H

1965-02-12

384

Factors influencing graphene growth on metal surfaces  

NASA Astrophysics Data System (ADS)

Graphene forms from a relatively dense, tightly bound C-adatom gas when elemental C is deposited on or segregates to the Ru(0001) surface. Nonlinearity of the graphene growth rate with C-adatom density suggests that growth proceeds by addition of C atom clusters to the graphene edge. The generality of this picture has now been studied by use of low-energy electron microscopy (LEEM) to observe graphene formation when Ru(0001) and Ir(111) surfaces are exposed to ethylene. The finding that graphene growth velocities and nucleation rates on Ru have precisely the same dependence on adatom concentration as for elemental C deposition implies that hydrocarbon decomposition only affects graphene growth through the rate of adatom formation. For ethylene, that rate decreases with increasing adatom concentration and graphene coverage. Initially, graphene growth on Ir(111) is like that on Ru: the growth velocity is the same nonlinear function of adatom concentration (albeit with much smaller equilibrium adatom concentrations, as we explain with DFT calculations of adatom formation energies). In the later stages of growth, graphene crystals that are rotated relative to the initial nuclei nucleate and grow. The rotated nuclei grow much faster. This difference suggests firstly, that the edge-orientation of the graphene sheets relative to the substrate plays an important role in the growth mechanism, and secondly, that attachment of the clusters to the graphene is the slowest step in cluster addition, rather than formation of clusters on the terraces.

Loginova, E.; Bartelt, N. C.; Feibelman, P. J.; McCarty, K. F.

2009-06-01

385

Differential signaling by the epidermal growth factor-like growth factors neuregulin-1 and neuregulin-2.  

PubMed

The neuregulins comprise a subfamily of epidermal growth factor (EGF)-like growth factors that elicit diverse cellular responses by activating members of the ErbB family of receptor tyrosine kinases. Although neuregulin-1 and neuregulin-2 are both binding ligands for the ErbB3 and ErbB4 receptors, they exhibit distinct biological activities depending on cellular context. In MDA-MB-468 human mammary tumor cells, neuregulin-2beta (NRG2beta) inhibits cell growth, whereas neuregulin-1beta (NRG1beta) does not. In these cells, NRG2beta appears to preferentially act through the EGF receptor, stimulating receptor tyrosine phosphorylation and the recruitment of phospholipase C-gamma, Cbl, SHP2, and Shc to that receptor. NRG1beta preferentially acts through ErbB3 in these cells by stimulating the tyrosine phosphorylation and recruitment of phosphatidylinositol 3-kinase and Shc to that receptor. In MDA-MB-453 cells, both NRG1beta and NRG2beta stimulate the tyrosine phosphorylation of the ErbB2 and ErbB3 receptors to similar extents, but only NRG1beta potently stimulates morphological changes consistent with their differentiation. The profiles of SH2 domain-containing proteins that are efficiently recruited to activated receptors differ for the two factors. These observations indicate that despite their overlapping receptor specificity, the neuregulins exhibit distinct biological and biochemical properties. Since both of these cell lines express only two of the known ErbB receptors, our results imply that EGF-like ligands might elicit differential signaling within the context of a single receptor heterodimer. PMID:9756944

Crovello, C S; Lai, C; Cantley, L C; Carraway, K L

1998-10-01

386

Possible role of transforming growth factor-?1 and vascular endothelial growth factor in Fabry disease nephropathy.  

PubMed

Fabry disease is a lysosomal storage disorder (LSD) caused by deficiency of ?-galactosidase A (?-gal A), resulting in deposition of globotriaosylceramide (Gb3; also known as ceramide trihexoside) in the vascular endothelium of many organs. A gradual accumulation of Gb3 leads to cardiovascular, cerebrovascular and renal dysfunction. Endothelial cell dysfunction leads to renal complications, one of the main symptoms of Fabry disease. However, the pathological mechanisms by which endothelial dysfunction occurs in Fabry disease are poorly characterized. The purpose of this study was to investigate whether the expression of transforming growth factor-?1 (TGF-?1) and vascular endothelial growth factor (VEGF) is associated with the renal pathogenesis of Fabry disease. We found that the protein expression levels of renal thrombospondin-1 (TSP-1), TGF-?1 and VEGF were higher in the kidneys from Fabry mice compared to wild-type mice. The expression levels of VEGF receptor 2 (VEGFR2), fibroblast growth factor-2 (FGF-2) and phospho-p38 (P-p38) were also higher in the kidneys from Fabry mice compared with wild-type mice. Activities of cysteine aspartic acid protease (caspase)-6 and caspase-9 were higher in kidneys from Fabry than from the wild-type mice. These results suggest that overexpression of TGF-?1 and VEGF in the Fabry mouse kidney might contribute to Fabry disease nephropathy by inducing apoptosis. To test whether Gb3 accumulation can induce apoptosis, we incubated bovine aortic endothelial cells with Gb3 and found increased expression of TGF-?1, VEGFR2, VEGF, FGF-2 and P-p38. The combination of increased expression of TGF-?1 and VEGF caused by Gb3 accumulation may allow upregulation of FGF-2, VEGFR2 and P-p38 expression, and these changes may be associated with Fabry disease nephropathy by inducing apoptosis. PMID:23007467

Lee, Mi Hee; Choi, Eun Nam; Jeon, Yeo Jin; Jung, Sung-Chul

2012-09-24

387

Heparin-binding epidermal growth factor-like growth factor suppresses experimental liver fibrosis in mice  

PubMed Central

Heparin-binding epidermal growth factor-like growth factor (HB-EGF) is a cytoprotective agent in several organ systems but its roles in liver fibrosis are unclear. We studied the roles of HB-EGF in experimental liver fibrosis in mice and during hepatic stellate cell (HSC) activation. Thioacetamide (TAA; 100mg/kg) was administered by intra-peritoneal injection three times a week for 4 weeks to wild-type HB-EGF+/+ or HB-EGF-null (HB-EGF?/?) male mice. Livers were examined for histology and expression of key fibrotic markers. Primary cultured HSC isolated from untreated HB-EGF+/+ or HB-EGF?/? mice were examined for fibrotic markers and/or cell migration either during culture-induced activation or after exogenous HB-EGF (100 ng/ml) treatment. TAA induced liver fibrosis in both HB-EGF+/+ and HB-EGF?/? mice. Hepatic HB-EGF expression was decreased in TAA-treated HB-EGF+/+ mice by 37.6% (p < 0.05) as compared to animals receiving saline alone. HB-EGF?/? mice treated with TAA showed increased hepatic ?-smooth muscle actin-positive cells and collagen deposition, and, as compared to HB-EGF+/+ mice, TAA-stimulated hepatic mRNA levels in HB-EGF?/? mice were, respectively, 2.1-, 1.7-, 1.8-, 2.2-, 1.2-, or 3.3-fold greater for ?-smooth muscle actin, ?1 chain of collagen I or III (COL1A1 or COL3A1), transforming growth factor-?1, connective tissue growth factor, or tissue inhibitor of metalloproteinase-1 (p < 0.05). HB-EGF expression was detectable in primary cultured HSC from HB-EGF+/+ mice. Both endogenous and exogenous HB-EGF inhibited HSC activation in primary culture, and HB-EGF enhanced HSC migration. These findings suggest that HB-EGF gene knockout in mice increases susceptibility to chronic TAA-induced hepatic fibrosis and that HB-EGF expression or action is associated with suppression of fibrogenic pathways in HSC.

Huang, Guangcun; Besner, Gail E.; Brigstock, David R.

2011-01-01

388

Growth factors are released by mechanically wounded endothelial cells  

Microsoft Academic Search

Growth factors may be required at sites of mechanical injury and normal wear and tear in vivo, suggesting that the direct action of mechanical forces on cells could lead to growth factor release. Scraping of cells from the tissue culture substratum at 37°C was used to test this possibility. We show that scraping closely mimics in vitro both the transient

Paul L. McNeil; Lakshmi Muthukrishnan; Elizabeth Warder; Patricia A. D

1989-01-01

389

Redundancy of myostatin and growth\\/differentiation factor 11 function  

Microsoft Academic Search

BACKGROUND: Myostatin (Mstn) and growth\\/differentiation factor 11 (Gdf11) are highly related transforming growth factor ? (TGF?) family members that play important roles in regulating embryonic development and adult tissue homeostasis. Despite their high degree of sequence identity, targeted mutations in these genes result in non-overlapping phenotypes affecting distinct biological processes. Loss of Mstn in mice causes a doubling of skeletal

Alexandra C McPherron; Thanh V Huynh; Se-Jin Lee

2009-01-01

390

Vascular endothelial growth factors and angiogenesis in eye disease  

Microsoft Academic Search

The vascular endothelial growth factor (VEGF) family of growth factors controls pathological angiogenesis and increased vascular permeability in important eye diseases such as diabetic retinopathy (DR) and age-related macular degeneration (AMD). The purpose of this review is to develop new insights into the cell biology of VEGFs and vascular cells in angiogenesis and vascular leakage in general, and to provide

A. N. Witmer; G. F. J. M. Vrensen; C. J. F Van Noorden; R. O. Schlingemann

2003-01-01

391

Autologous fibrin glue with growth factors in reconstructive maxillofacial surgery  

Microsoft Academic Search

The aim of this paper was to describe a method for the preparation of autologous fibrin glue with platelet growth factors and to report its use with particulate cancellous bone in reconstructive maxillofacial surgery. The fibrin glue is a two-component glue, where the one component is a concentrated fibrinogen solution with platelet growth factors and the other component is a

J. J. Thorn; H. Sørensen; U. Weis-Fogh; M. Andersen

2004-01-01

392

Vascular-specific growth factors and blood vessel formation  

Microsoft Academic Search

A recent explosion in newly discovered vascular growth factors has coincided with exploitation of powerful new genetic approaches for studying vascular development. An emerging rule is that all of these factors must be used in perfect harmony to form functional vessels. These new findings also demand re-evaluation of therapeutic efforts aimed at regulating blood vessel growth in ischaemia, cancer and

George D. Yancopoulos; Samuel Davis; Nicholas W. Gale; John S. Rudge; Stanley J. Wiegand; Jocelyn Holash

2000-01-01

393

GROWTH FACTOR REQUIREMENTS OF SIX FUNGI ASSOCIATED WITH FRUIT DECAY  

PubMed Central

Esposito, R. G. (United Fruit Co., Norwood, Mass.), H. Greenwood, and A. M. Fletcher. Growth factor requirements of six fungi associated with fruit decay. J. Bacteriol. 83:–250–255. 1962.—A study of the growth factor requirements of representatives of six genera of fruit-rotting fungi has been made. Gloeosporium musarum, Nigrospora sphaerica, Thielaviopsis paradoxa, and Verticillium theobromae all required biotin for growth. Under certain conditions in nitrate medium, Fusarium roseum appeared to be partially dependent on biotin. T. paradoxa also required thiamine for growth. In