FGF-7 facilitates the process of psoriasis by inducing TNF-α expression in HaCaT cells.

The purpose of this study was to uncover the mechanism of tumor necrosis factor (TNF)-α induction by fibroblast growth factor-7 (FGF-7) in human HaCaT cells and the potential role of FGF-7-specific antibody F-9 in psoriatic therapy. TNF-α expression in HaCaT cells induced by FGF-7 was analyzed by quantitative polymerase chain reaction, western blot analysis, and enzyme-linked immunosorbent assays. In vivo, the BALB/c mouse psoriasis model established by topical application of imiquimod (IMQ) was used to determine the role of FGF-7-specific antibody (F-9) in skin inflammation. We found that induction of TNF-α expression by FGF-7 in HaCaT cells was suppressed by FGF-7-specific antibody F-9. Western blot analysis results showed that FGF-7 induced TNF-α expression in HaCaT cells via the FGF receptor 2 (FGFR2)/AKT/NF-κB signaling pathway. In vivo, F-9 could significantly ameliorate the inflammations in a mouse psoriatic model evaluated by Psoriasis Area and Severity Index scores and ear thickness, which was consistent with the results of hematoxylin-eosin staining, immunohistochemistry assay, and western blot analysis. These results indicate that FGF-7 induces TNF-α expression in HaCaT cells and FGF-7 antibody F-9 alleviates IMQ-induced psoriasiform in mice. Therefore, FGF-7/FGFR2 signaling pathway is a potential target for psoriasis treatment.

Intraurethral injection with LPS: an effective experimental model of prostatic inflammation.

OBJECTIVE: Chronic inflammation has been recognized as having a prominent role pathogenesis of benign prostatic hyperplasia (BPH) and cancer. It is believed that chronic inflammation induces prostatic fibromuscular growth. This correlation has been clearly illustrated by both in vivo and in vitro studies; however, current experimental models of BPH require complex surgery or hormonal treatment. Therefore, the aim of the present study was to propose a new murine model of BPH/prostatitis induced by intraurethral injection of LPS. METHODS: Male Swiss and C57Bl/6 mice were then sacrificed 3, 7, 10, and 14 days after intraurethral injection of LPS. The prostates were quickly dissected and fixed for morphological and immunohistochemical analyses. RESULTS: The results showed that LPS played an important role in the cell proliferation of the prostate. Histological and ultrastructural analysis showed epithelial hyperplasia, clear stromal cells, little inflammatory infiltration, and heavy bleeding. Treatment with LPS also promoted the increase of growth factor (FGF-7 and TGF-ß), α-actin, and proinflammatory cytokines (IL-1, IL-6, IL-17), both in the stroma and epithelium. CONCLUSION: According to the present findings, it can be concluded that the intraurethral administration of LPS promotes tissue remodeling, as well as stimulating the pattern of pro-inflammatory cytokines, and therefore, constitutes an effective experimental model of BPH/inflammation.

Up-regulation of intestinal epithelial cell derived IL-7 expression by keratinocyte growth factor through STAT1/IRF-1, IRF-2 pathway.

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.

A stimulation-dependent alternate core promoter links lymphotoxin α expression with TGF-ß1 and fibroblast growth factor-7 signaling in primary human T cells.

Lymphotoxin (LT)-α regulates many biologic activities, yet little is known of the regulation of its gene. In this study, the contribution to LTA transcriptional regulation of the region between the transcription and translation start sites (downstream segment) was investigated. The LTA downstream segment was found to be required for, and alone to be sufficient for, maximal transcriptional activity in both T and B lymphocytes. The latter observation suggested that an alternate core promoter might be present in the downstream segment. Characterization of LTA mRNAs isolated from primary and from transformed human T cells under different stimulation conditions identified eight unique transcript variants (TVs), including one (LTA TV8) that initiated within a polypyrimidine tract near the 3' end of the downstream segment. Further investigation determined that the LTA downstream segment alternate core promoter that produces the LTA TV8 transcript most likely consists of a stimulating protein 1 binding site and an initiator element and that factors involved in transcription initiation (stimulating protein 1, TFII-I, and RNA polymerase II) bind to this LTA region in vivo. Interestingly, the LTA downstream segment alternate core promoter was active only after specific cellular stimulation and was the major promoter used when human T cells were stimulated with TGF-ß1 and fibroblast growth factor-7. Most importantly, this study provides evidence of a direct link for crosstalk between T cells and epithelial/stromal cells that has implications for LT signaling by T cells in the cooperative regulation of various processes typically associated with TGF-ßR and fibroblast growth factor-R2 signaling.

Keratinocyte growth factor augments pulmonary innate immunity through epithelium-driven, GM-CSF-dependent paracrine activation of alveolar macrophages.

Keratinocyte growth factor (KGF) is an epithelial mitogen that has been reported to protect the lungs from a variety of insults. In this study, we tested the hypothesis that KGF augments pulmonary host defense. We found that a single dose of intrapulmonary KGF enhanced the clearance of Escherichia coli or Pseudomonas aeruginosa instilled into the lungs 24 h later. KGF augmented the recruitment, phagocytic activity, and oxidant responses of alveolar macrophages, including lipopolysaccharide-stimulated nitric oxide release and zymosan-induced superoxide production. Less robust alveolar macrophage recruitment and activation was observed in mice treated with intraperitoneal KGF. KGF treatment was associated with increased levels of MIP1γ, LIX, VCAM, IGFBP-6, and GM-CSF in the bronchoalveolar lavage fluid. Of these, only GM-CSF recapitulated in vitro the macrophage activation phenotype seen in the KGF-treated animals. The KGF-stimulated increase in GM-CSF levels in lung tissue and alveolar lining fluid arose from the epithelium, peaked within 1 h, and was associated with STAT5 phosphorylation in alveolar macrophages, consistent with epithelium-driven paracrine activation of macrophage signaling through the KGF receptor/GM-CSF/GM-CSF receptor/JAK-STAT axis. Enhanced bacterial clearance did not occur in response to KGF administration in GM-CSF(-/-) mice, or in mice treated with a neutralizing antibody to GM-CSF. We conclude that KGF enhances alveolar host defense through GM-CSF-stimulated macrophage activation. KGF administration may constitute a promising therapeutic strategy to augment innate immune defenses in refractory pulmonary infections.

Therapeutic effects of vitamin A on experimental cholestatic rats with hepatic fibrosis.

PURPOSE: The aim of this study is to investigate the role of hepatic stellate cells (HSCs) and the effect of vitamin A administration on liver damage induced by bile duct ligation (BDL) and administration of CCl(4). METHODS: Two types of animal model were used; one was BDL as a model of biliary atresia, the other was CCl(4)-induced hepatic fibrosis. Pathological changes of the liver with or without administration of vitamin A were compared by light and electron microscopy with focusing on HSCs in each experimental group. Immunohistochemical examination was performed with anti-keratinocyte growth factor (KGF), anti-alpha-smooth muscle actin (α-SMA), and anti-glial fibrillary acidic protein (GFAP) antibodies, as markers of fibrosis. RESULTS: On light microscopic findings, periportal inflammation with bile ductular proliferation was obvious in BDL group and pericentral necrosis with fatty degeneration was observed in CCl(4) group, both of which were ameliorated by subcutaneous injection of vitamin A. Electron microscopy showed lipid droplets were almost depleted in the HSCs treated with BDL or CCl(4), which improved with vitamin A administration. Immunohistochemistry demonstrated that enhanced expression of all three fibrotic markers in the BDL group was diminished by vitamin A administration. CONCLUSIONS: Although most of our data are qualitative observation, vitamin A may ameliorate hepatic fibrosis in the BDL model by restoring vitamin A in the HSCs.

Keratinocyte Growth Factor Stimulates Macrophage Inflammatory Protein 3α and Keratinocyte-derived Chemokine Secretion by Mouse Uterine Epithelial Cells.

PROBLEM: communication between uterine epithelial cells and the underlying stromal fibroblasts is critical for proper endometrial function. Stromal fibroblast-derived growth factors have been shown to regulate epithelial immune functions. The purpose of this study was to determine whether keratinocyte growth factor (KGF) regulates uterine epithelial cell chemokine and antimicrobial secretion. METHOD OF STUDY: uterine epithelial cells were isolated from Balb/c mice and cultured in either 96-well plates or transwell inserts. Epithelial cells were treated with KGF, epidermal growth factor (EGF), or hepatocyte growth factor (HGF). Macrophage inflammatory protein 3α (MIP3α) and keratinocyte-derived chemokine (KC) levels were measured by ELISA. RESULTS: keratinocyte growth factor stimulated the secretion of MIP3α and KC. The effects on MIP3α by KGF were specific because EGF and HGF had no effect. In contrast, KGF, EGF, and HGF had similar effects on KC. Furthermore, KGF administered to the apical side of epithelial cells had no effect on MIP3α or KC secretion, indicating that the KGF receptor is located on the basolateral surface of uterine epithelial cells. CONCLUSION: we demonstrate that KGF plays a role in uterine epithelial cell secretion of MIP3α and KC, key immune mediators involved in the protection of mucosal surfaces in the female reproductive tract.

Effect of tumour-cell-derived or recombinant keratinocyte growth factor (KGF) on proliferation and radioresponse of human epithelial tumour cells (HNSCC) and normal keratinocytes in vitro.

Purpose of this work was to test the effect of tumour-cell-derived keratinocyte growth factor (KGF) or recombinant KGF (palifermin) on cell proliferation and radiation response of human HNSCC cells and normal keratinocytes in vitro. Four tumour cell cultures derived from head and neck squamous cell carcinomas, primary keratinocytes, and immortalized keratinocytes were analysed. Fibroblasts, the natural source of KGF protein, served as controls. KGF expression was observed in primary and immortalized keratinocytes, fibroblasts, and in tumour cells, while significant KGF receptor expression was only found in keratinocytes. Recombinant KGF as well as tumour-cell-derived KGF caused a significant growth stimulation and radioprotection in keratinocytes, which was abolished by a neutralizing anti-KGF antibody. This indicates that tumour-cell-derived KGF is biologically active. In the tumour cell lines, no significant growth stimulation was induced by recombinant KGF, and the neutralizing antibody did not influence tumour cell growth or radiation response. Our results indicate that the normal, paracrine KGF regulatory mechanisms, which are based on KGF receptor expression, are lost in malignant cells, with the consequence of irresponsiveness of the tumour cells to exogenous KGF. In face of the amelioration of the radiation response of normal epithelia, demonstrated in various clinical and various preclinical animal studies, recombinant KGF represents a candidate for the selective protection of normal epithelia during radio(chemo) therapy of squamous cell carcinoma.

Dendritic epidermal T cells: their role in the early phase of ectromelia virus infection.

INTRODUCTION: Dendritic epidermal T cells (DETCs) are bone marrow-derived T lymphocytes that express a canonical gammadelta TCR and form a dense network in the murine skin. Here, we sought to determine their role during the early phase of ectromelia virus (ECTV) infection. MATERIALS/METHODS: In vivo and in vitro models were established for this purpose. In the first model, C57BL/6 mice were intradermally infected into the central part of the ear pinnas with 105 PFU ECTV-Mos strain per ear. At indicated time-points, the total pinna cell population was isolated to determine the presence of DETCs and the enumeration of DETCs secreting IFN-gamma under in vitro stimulation. Purified DETCs were also analyzed for certain gene expressions by RT-PCR. In the second model, purified DETCs isolated from pinnas of uninfected C57BL/6 mice were stimulated in vitro with 5 MOI of UV-inactivated ECTV-Mos. Total RNA was isolated at indicated time-points for RT-PCR gene expression evaluation. RESULTS: A rapid increase in DETCs number in the pinnas was observed for 24 hours post-infection. During the next 24 h the DETCs number decreased, reaching control values. Rapid but short-lasting INF-gamma secretion by purified DETCs in vitro was observed and correlated well with the expression of the beta chemokine CCL5 gene responsible for macrophage and neutrophil attraction. It was also accompanied by DETCs expression of the immunoregulatory factors TGF-beta, GM-CSF, and KGF genes important for maintaining skin integrity. CONCLUSIONS: DETCs from mice infected with ECTV-Mos were rapidly induced to cascade the secretion of mediators that contribute to both immune protection and the control of skin integrity.

Thymic involution and immune reconstitution.

Chronic thymus involution associated with aging results in less efficient T-cell development and decreased emigration of naïve T cells to the periphery. Thymic decline in the aged is linked to increased morbidity and mortality in a wide range of clinical settings. Negative consequences of these effects on global health make it of paramount importance to understand the mechanisms driving thymic involution and homeostatic processes across the lifespan. There is growing evidence that thymus tissue is plastic and that the involution process might be therapeutically halted or reversed. We present here progress on the exploitation of thymosuppressive and thymostimulatory pathways using factors such as keratinocyte growth factor, interleukin 7 or sex steroid ablation for therapeutic thymus restoration and peripheral immune reconstitution in adults.

A critical role for fibroblast growth factor-7 during early alveolar formation in the neonatal rat.

Mesenchymal cell-derived FGF-7 (fibroblast growth factor-7) induces proliferation in both epithelial and endothelial cells. We found FGF-7 to be expressed in the lungs of neonatal rats from birth to d 14 of age. A role for FGF-7 in early postnatal lung growth and alveolar formation, by an action on type II pneumocytes, has been excluded by the work of others. However, a role through an action of FGF-7 on other cell types has not been excluded. We used intraperitoneal injections of neutralizing antibodies on d 3, 4, and 5 of life to inhibit binding of FGF-7 to its receptors, and assessed alveolar formation on d 6 of life. This intervention inhibited DNA synthesis in, and number of, alveoli-forming secondary crests, resulting in a significantly reduced alveolar number. This failure of alveolar formation was associated with a reduction in the number of small blood vessels in the lung periphery. We conclude that FGF-7, most likely through its effect on the vascular bed, is required for normal early postnatal alveolar formation from secondary crests.

Hematopoietic growth factors including keratinocyte growth factor in allogeneic and autologous stem cell transplantation.

The aim of hematopoietic stem cell transplantation (HSCT) is to cure patients of malignancies, autoimmune diseases, and immunodeficiency disorders by redirecting the immune system: the often described graft-versus-leukemia (GVL) or graft-versus-tumor (GVT) effects. Unfortunately, fulfillment of this goal is often hampered by relapse of the underlying disease, graft-versus-host disease (GVHD), or severe opportunistic infections, which account for the majority of post-transplantation deaths. Moreover, studies of long-term survivors of transplantation indicate an accelerated immune aging due to the transplantation procedure itself, preceding chemo- or radiotherapy, and acute and chronic GVHD. Significant advances have been made towards overcoming these obstacles by enhancing immune reconstitution with hematopoietic growth factors (HGFs) such as granulocyte colony-stimulating factor (G-CSF) or erythropoietin (EPO) or through the application of cytokines. In addition, there are approaches to promote the thymic-dependent development of naive T cells, which are prepared for the interaction with a multitude of pathogens. Examples are the application of keratinocyte growth factor (KGF), neuroendocrine hormones such as growth hormone or prolactin, sex hormone ablation, or the invention of a three-dimensional artificial thymus based on a cytomatrix. Might these measures result in a higher rate of healthy and fully recovered patients? Here we review progress in each of these areas.

Keratinocyte growth factor (KGF) enhances postnatal T-cell development via enhancements in proliferation and function of thymic epithelial cells.

The systemic administration of keratinocyte growth factor (KGF) enhances T-cell lymphopoiesis in normal mice and mice that received a bone marrow transplant. KGF exerts protection to thymic stromal cells from cytoablative conditioning and graft-versus-host disease-induced injury. However, little is known regarding KGF's molecular and cellular mechanisms of action on thymic stromal cells. Here, we report that KGF induces in vivo a transient expansion of both mature and immature thymic epithelial cells (TECs) and promotes the differentiation of the latter type of cells. The increased TEC numbers return within 2 weeks to normal values and the microenvironment displays a normal architectural organization. Stromal changes initiate an expansion of immature thymocytes and permit regular T-cell development at an increased rate and for an extended period of time. KGF signaling in TECs activates both the p53 and NF-kappaB pathways and results in the transcription of several target genes necessary for TEC function and T-cell development, including bone morphogenetic protein 2 (BMP2), BMP4, Wnt5b, and Wnt10b. Signaling via the canonical BMP pathway is critical for the KGF effects. Taken together, these data provide new insights into the mechanism(s) of action of exogenous KGF on TEC function and thymopoiesis.