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Publication
Journal: Journal of Molecular Biology
October/8/2009
Abstract
The <em>22</em> members of the mouse/human <em>fibroblast</em> <em>growth</em> <em>factor</em> (FGF) family of proteins contain a conserved cysteine residue at position 83 (numbering scheme of the 140-residue form of FGF-1). Sequence and structure information suggests that this position is a free cysteine in 16 members and participates as a half-cystine in at least 3 (and perhaps as many as 6) other members. While a structural role as a half-cystine provides a stability basis for possible selective pressure, it is less clear why this residue is conserved as a free cysteine (although free buried thiols can limit protein functional half-life). To probe the structural role of the free cysteine at position 83 in FGF-1, we constructed Ala, Ser, Thr, Val, and Ile mutations and determined their effects on structure and stability. These results show that position 83 in FGF-1 is thermodynamically optimized to accept a free cysteine. A second cysteine mutation was introduced into wild-type FGF-1 at adjacent position Ala66, which is known to participate as a half-cystine with position 83 in FGF-8, FGF-19, and FGF-23. Results show that, unlike position 83, a free cysteine at position 66 destabilizes FGF-1; however, upon oxidation, a near-optimal disulfide bond is formed between Cys66 and Cys83, resulting in approximately 14 kJ/mol of increased thermostability. Thus, while the conserved free cysteine at position 83 in the majority of the FGF proteins may have a principal role in limiting functional half-life, evidence suggests that it is a vestigial half-cystine.
Publication
Journal: Journal of Cellular Physiology
September/11/1996
Abstract
Angiogenesis, new vessel <em>growth</em> from existing vessels, is critical to tissue development and healing. Much is known about the molecular and cellular elements of angiogenesis, such as the effects of <em>growth</em> <em>factors</em> and matrix molecules on proliferation and migration. However, it is not clear how these elements are coordinated to produce specific microvascular beds. To address this, the effects of basic <em>fibroblast</em> <em>growth</em> <em>factor</em> (bFGF) on beta 1 integrin-mediated adhesion relative to migration in human microvessel endothelial cells (HMVEC) was examined. Using two assays of migration that differ in the density of cells being examined, bFGF stimulated single cell migration and reduced cell migration from a confluent monolayer on collagen I. Adhesion to collagen I of HMVEC treated at low density (2-4 x 10(4) cells/cm2) with bFGF for <em>22</em> h was reduced, while bFGF increased cell adhesion of HMVEC treated at high density (6-8 x 10(4) cells/cm2). Adhesion of both bFGF-treated and untreated HMVEC was mediated by the beta 1 integrin matrix receptor. Basic FGF treatment did not significantly alter surface expression of the beta 1 integrin subunit. Reduction in bFGF-mediated adhesion correlated with delayed cell spreading and altered organization of beta 1 integrin into substrate contacts. Thus, integrin-mediated cell adhesion in microvessel endothelial cells is sensitive to regulation by a <em>growth</em> <em>factor</em>. Furthermore, the nature of the response to this signal depends on another cell regulator, cell density. In addition, modulation of cell adhesion by a <em>growth</em> <em>factor</em> may be a central regulatory feature in controlling endothelial cell migration.
Publication
Journal: Experimental Cell Research
July/20/2006
Abstract
The superfamily of <em>fibroblast</em> <em>growth</em> <em>factors</em> (FGF), which counts <em>22</em> members in humans, exerts many functions during animal development and adult life. LET-756 is one of the two FGFs of the nematode C. elegans. Re-introduction of LET-756 in a null mutant strain restores viability, allowing the study of structural requirements for LET-756 trafficking and function. LET-756 protein has several regions and motifs, including a non-classical internal motif required for secretion. We show here that a main difference in the wild-type LET-756 molecule and a truncated molecule that mimics a partial loss-of-function mutant lies on subnuclear expression. Using Cos-1 cells and rescue activity we show that: (i) nuclear localization is due to various redundant NLS, one of them acting as a nucleolar localization signal; (ii) nuclear LET-756 is addressed to the speckles by a stretch of glutamine residues; (iii) nuclear LET-756 is trafficking between speckles and nucleoli; (iv) in the nucleolus, LET-756 is associated with proteins of the rRNA splicing compartment; (v) changing LET-756 secretion signal prevents its nuclear localization. We propose that LET-756 exerts its functions through a balance between secreted and nuclear forms due to two opposite addressing signals, (i) synergy of several NLS and (ii) attenuated secretion signal.
Publication
Journal: Cancer Science
March/24/2012
Abstract
Whole genome-scale integrated analyses of exon array and array-comparative genomic hybridization are expected to enable the identification of unknown genetic features of cancer cells. Here, we evaluated this approach in <em>22</em> gastric and colorectal cancer cell lines, focusing on protein kinase genes and genes belonging to the cadherin-catenin family. Regarding alternative splicing patterns, several cancer cell lines predominantly expressed isoform 1 of protein kinase A catalytic subunit beta (PRKACB). Paired gastric cancer specimens demonstrated that isoform 1 of PRKACB was a novel cancer-related variant transcript in gastric cancers. In addition, the exon array analysis clearly identified exon 3 or exon 3-4 skipping in catenin beta 1, a short intron insertion with exon 9 skipping in CDH1, and a deletional transcript of CDH13. These abnormal transcripts were shown to have arisen from small genomic deletions. Meanwhile, an integrated analysis of 11 gastric cancer cell lines revealed that four cell lines amplified <em>fibroblast</em> <em>growth</em> <em>factor</em> receptor 2, with truncated forms observed in two of the cell lines. Gene amplification, and not the truncated form, was found to determine the sensitivity to a <em>fibroblast</em> <em>growth</em> <em>factor</em> receptor inhibitor, indicating that our cell line panel might be useful for cell-based evaluations of specific inhibitors. Using an integrated analysis, we identified several abnormal transcripts and genomic alterations in gastric and colorectal cancer cells. Our approach might enable genetic changes to be identified more efficiently, and the present results warrant further investigation using clinical samples and integrated analyses.
Publication
Journal: Experimental Lung Research
December/21/1986
Abstract
The regulation of DNA synthesis in 19 day rat fetal lung epithelial (alveolar type II) and mesenchymal (<em>fibroblast</em>) cells by protein <em>growth</em> <em>factors</em> has been studied. In each case a single <em>growth</em> <em>factor</em> is capable of stimulating 3H-thymidine incorporation into DNA: platelet-derived <em>growth</em> <em>factor</em> in the case of the alveolar type II cell and epidermal <em>growth</em> <em>factor</em> in the case of the fetal lung <em>fibroblast</em>. We hypothesize that these results indicate that the type II cell endogenously produces progression activities (i.e., epidermal <em>growth</em> <em>factor</em>-like and somatomedin-like activity) while the <em>fibroblast</em> produces competence (i.e., platelet-derived <em>growth</em> <em>factor</em>-like) and progression (i.e., somatomedin-like activity). The latter is in keeping with previous observations with skin <em>fibroblasts</em>. To test the above hypothesis, the effect of fetal lung <em>fibroblast</em>-derived conditioned media upon the <em>growth</em> of fetal alveolar type II cells has been determined. The results indicate that, indeed, such media contain competence activity for this cell type. The mitogenic activity was further characterized as heat-sensitive, trypsin-sensitive, and has an apparent molecular weight of 30,000 Daltons. It is not synthesized by 19 day fetal liver, kidney or skin <em>fibroblasts</em> and its synthesis is higher in lung <em>fibroblasts</em> isolated from 19 day fetuses as compared to those isolated on day 16 or day <em>22</em>.
Publication
Journal: Proceedings of the National Academy of Sciences of the United States of America
May/3/1993
Abstract
The expression of the major protein kinase C (PKC) substrate, originally called "80K" for acidic SDS/PAGE-observed 80-kDa PKC substrate and now called "MARCKS" for myristoylated alanine-rich C kinase substrate, in Swiss 3T3 <em>fibroblasts</em> changes strikingly (15- to <em>22</em>-fold) during transitions of cell <em>growth</em>. Quiescent cells in G0 express high levels of MARCKS mRNA and protein. However, plating these cells in fresh medium at low density to stimulate multiple rounds of cell division caused a striking down-regulation of MARCKS expression. The mRNA level declined to a minimum of 4.5% compared with quiescent control cells 6 hr after plating, and protein levels declined during the same period to 6.5% of the control value. This rapid down-regulation was independent of PKC activation and length of exposure to trypsin (1-10 min) but required plating in medium containing fresh serum. MARCKS mRNA and protein levels remained down-regulated for 3 days, during which time the cells were actively progressing through the cell cycle as judged by fluorescence-activated cell sorting analysis. However, on reaching quiescence, the expression of MARCKS mRNA and protein increased markedly. Furthermore, the rate of recovery of MARCKS mRNA and protein levels was shown to be dependent on the supply of serum-derived <em>growth</em> <em>factors</em> in the medium. Addition of hydroxyurea to arrest the cells in S phase or at the G1/S boundary rather than G0 completely prevented the recovery of MARCKS protein. The down-regulation of MARCKS following plating and its serum-dependent recovery was also demonstrated in tertiary cultures of mouse embryo <em>fibroblasts</em>. The results suggest that MARCKS may play a role in the regulation of entry and exit of cells from G0.
Publication
Journal: Biochemical and Biophysical Research Communications
July/4/1991
Abstract
Northern blot analysis showed transcripts of two types of the <em>fibroblast</em> <em>growth</em> <em>factor</em> (FGF) receptor genes, flg and bek, in almost all the tissues samples of 18 human gliomas and <em>22</em> human meningiomas, which produced abundant basic and/or acidic FGF. From immunohistochemistry, FGF receptors were expressed in the tumor cells of a glioma and a meningioma. RNA expression of these FGF receptors was also detectable in normal human brains and normal bovine meninges. The expression level of either FGF receptor gene was not significantly different between tumor tissues and normal tissues.
Publication
Journal: Reproduction
August/17/2006
Abstract
The aim of this study was to evaluate the expression pattern of <em>fibroblast</em> <em>growth</em> <em>factor</em> 2 (FGF2), its receptor variants (FGFR1IIIc, FGFR2IIIc) and nucleolin in time-defined follicle classes before and after GnRH application and after ovulation in the cow. Ovaries containing preovulatory follicles or new corpora lutea (CL) were collected at approximately 0, 4, 10, 20 and 25 h (follicles) and 60 h (new CL) relative to injection of GnRH to induce an LH surge (n = 5 animals per group). The expressions of FGF2 and FGFR1IIIc mRNA were significantly up-regulated only in the follicle group 4 h after GnRH (during the LH surge) with a significant down-regulation immediately afterwards. Western blot analyses showed two protein bands with at <em>22</em> and 18 kDa with apparent up-regulation beginning with the LH surge (4 h) and maximum levels 20 h after GnRH. FGF2 protein in follicles collected at 0 h (before LH surge) was localised in theca tissue (endothelial and pericytes of blood vessels) but not in granulosa cells (GCs). The FGF2 staining (by immunohistochemistry) pattern changed dramatically after the LH surge for a short period (about 2 days) and FGF2 protein was localised dominantly in the nucleus of many GCs, while most capillary endothelial cells were FGF2 immunonegative. In conclusion, the novel observation of FGF2 up-regulation and the distinct change in FGF2 localisation from theca (cytoplasm of endothelial cells) to the nucleus of GCs after the LH surge may be important for survival of GCs or for the transition of the GCs to luteal cells.
Publication
Journal: Clinical Orthopaedics and Related Research
January/29/1997
Abstract
The effect of basic <em>fibroblast</em> <em>growth</em> <em>factor</em> on tissue in<em>growth</em> and differentiation in porous hydroxyapatite of coralline origin was studied in a bone chamber model. The hydroxyapatite with or without basic <em>fibroblast</em> <em>growth</em> <em>factor</em> was placed in <em>22</em> mm3 titanium bone conduction chambers implanted bilaterally in rat tibiae. Ingrowing bone could enter the cylindrical interior of the chamber only at 1 end. It then penetrated the porous hydroxyapatite inside the chamber. The distance that the ingrown tissue had reached into the material then was measured on histologic slides. Because fibrous tissue always reached further into the material than did bone, both total tissue in<em>growth</em> and bone in<em>growth</em> distances were measured. In implants supplemented with 0.04 microg basic <em>fibroblast</em> <em>growth</em> <em>factor</em> in a hyaluronate gel carrier, the bone in<em>growth</em> distance was increased by 70% at 6 weeks, as compared with paired controls in the contralateral leg. The total tissue in<em>growth</em> distance also was increased by 58%. When the dose of basic <em>fibroblast</em> <em>growth</em> <em>factor</em> was increased to 1.0 microg, still using the hyaluronate carrier, there was no difference in bone in<em>growth</em> compared with controls, but this dose still increased the total tissue in<em>growth</em>. In hydroxyapatite with 1.5 microg basic <em>fibroblast</em> <em>growth</em> <em>factor</em> without hyaluronate gel at 4 weeks, no increase in bone in<em>growth</em> was shown, but total tissue in<em>growth</em> was increased. At 6 weeks, bone in<em>growth</em> and total tissue in<em>growth</em> were increased by 41% and 33%, respectively. With a lower dose of 0.15 microg without carrier, only the total in<em>growth</em> distance was increased. The results suggest that basic <em>fibroblast</em> <em>growth</em> <em>factor</em> may promote tissue in<em>growth</em> into porous hydroxyapatite and that bone in<em>growth</em> may be increased by appropriate doses. The hyaluronate gel carrier reduced the optimal dose.
Publication
Journal: Haematologica
November/21/2017
Abstract
The importance of the tumor microenvironment in chronic lymphocytic leukemia is widely accepted. Nevertheless, the understanding of the complex interplay between the various types of bystander cells and chronic lymphocytic leukemia cells is incomplete. Numerous studies have indicated that bystander cells provide chronic lymphocytic leukemia-supportive functions, but it has also become clear that chronic lymphocytic leukemia cells actively engage in the formation of a supportive tumor microenvironment through several cross-talk mechanisms. In this review, we describe how chronic lymphocytic leukemia cells participate in this interplay by inducing migration and tumor-supportive differentiation of bystander cells. Furthermore, chronic lymphocytic leukemia-mediated alterations in the interactions between bystander cells are discussed. Upon bystander cell interaction, chronic lymphocytic leukemia cells secrete cytokines and chemokines such as migratory <em>factors</em> [chemokine (C-C motif) ligand <em>22</em> and chemokine (CC motif) ligand 2], which result in further recruitment of T cells but also of monocyte-derived cells. Within the tumor microenvironment, chronic lymphocytic leukemia cells induce differentiation towards a tumor-supportive M2 phenotype of monocyte-derived cells and suppress phagocytosis, but also induce increased numbers of supportive regulatory T cells. Like other tumor types, the differentiation of stromal cells towards supportive cancer-associated <em>fibroblasts</em> is critically dependent on chronic lymphocytic leukemia-derived <em>factors</em> such as exosomes and platelet-derived <em>growth</em> <em>factor</em>. Lastly, both chronic lymphocytic leukemia and bystander cells induce a tolerogenic tumor microenvironment; chronic lymphocytic leukemia-secreted cytokines, such as interleukin-10, suppress cytotoxic T-cell functions, while chronic lymphocytic leukemia-associated monocyte-derived cells contribute to suppression of T-cell function by producing the immune checkpoint <em>factor</em>, programmed cell death-ligand 1. Deeper understanding of the active involvement and cross-talk of chronic lymphocytic leukemia cells in shaping the tumor microenvironment may offer novel clues for designing therapeutic strategies.
Publication
Journal: PLoS ONE
December/29/2011
Abstract
Secreted proteins of the <em>fibroblast</em> <em>growth</em> <em>factor</em> (FGF) family play important roles during development of various organ systems. A detailed knowledge of their temporal and spatial expression profiles, especially of closely related FGF family members, are essential to further identification of specific functions in distinct tissues. In the central nervous system dopaminergic neurons of the substantia nigra and their axonal projections into the striatum progressively degenerate in Parkinson's disease. In contrast, FGF-2 deficient mice display increased numbers of dopaminergic neurons. In this study, we determined the expression profiles of all <em>22</em> FGF-ligands and 10 FGF-receptor isoforms, in order to clarify, if FGF-2 deficiency leads to compensatory up-regulation of other FGFs in the nigrostriatal system. Three tissues, ventral mesencephalon (VM), striatum (STR) and as reference tissue spinal cord (SC) of wild-type and FGF-2 deficient mice at four developmental stages E14.5, P0, P28, and adult were comparatively analyzed by quantitative RT-PCR. As no differences between the genotypes were observed, a compensatory up-regulation can be excluded. Moreover, this analysis revealed that the majority of FGF-ligands (18/<em>22</em>) and FGF-receptors (9/10) are expressed during normal development of the nigrostriatal system and identified dynamic changes for some family members. By comparing relative expression level changes to SC reference tissue, general alterations in all 3 tissues, such as increased expression of FGF-1, -2, -<em>22</em>, FgfR-2c, -3c and decreased expression of FGF-13 during postnatal development were identified. Further, specific changes affecting only one tissue, such as increased FGF-16 (STR) or decreased FGF-17 (VM) expression, or two tissues, such as decreased expression of FGF-8 (VM, STR) and FGF-15 (SC, VM) were found. Moreover, 3 developmentally down-regulated FGFs (FGF-8b, FGF-15, FGF-17a) were functionally characterized by plasmid-based over-expression in dissociated E11.5 VM cell cultures, however, such a continuous exposure had no influence on the yield of dopaminergic neurons in vitro.
Publication
Journal: Endocrinology
September/20/1990
Abstract
Interstitial tissue of the testis consists of Leydig cells, macrophages, lymphocytes, plasma cells, mast cells and <em>fibroblasts</em>. Previously we have reported that interleukin-1 (IL-1) inhibits Leydig cell androgen production. In the present study, the effect of IL-2 was investigated. Leydig cells (10(5) cells/ml) from adult Sprague-Dawley rats were cultured with or without IL-2 for 24 h. After medium changes, human CG (hCG), 8-bromo-cAMP, or forskolin was added with or without IL-2. Cultures were continued for an additional 24 h, and testosterone and cAMP levels were measured. IL-2 up to 100 U/ml had no effect on basal testosterone production. hCG-stimulated testosterone formation was inhibited in a dose-dependent manner by the addition of IL-2. IL-2 in a concentration of 100 U/ml decreased hCG-induced testosterone formation from 49.6 +/- 3.6 ng/ml (mean +/- SE) to 8.5 +/- 4.2 ng/ml. The hCG dose-response curve was shifted to the right by the addition of IL-2. Maximal testosterone production in response to hCG was reduced 40% in the presence of IL-2 (50 U/ml) without alteration of median effective dose (ED50). IL-2 also inhibited hCG-induced cAMP formation and 8-bromo cAMP- and forskolin-stimulated testosterone production. However, IL-2 did not alter the binding of [125I]hCG to purified Leydig cells. Furthermore, IL-2 significantly inhibited the conversion of 20-OH-cholesterol, <em>22</em>-OH-cholesterol, pregnenolone, progesterone, 17 alpha-hydroxypregnenolone, and 17 alpha-hydroxyprogesterone to testosterone but did not alter the conversion of dehydroepiandrosterone and androstenedione to testosterone. Our results suggest that a T cell <em>growth</em> <em>factor</em>, IL-2, is a potent inhibitor of steroidogenesis. IL-2 may play a paracrine role in modulating Leydig cell function.
Publication
Journal: Advances in Skin and Wound Care
October/14/2008
Abstract
OBJECTIVE
This study examined the bioactivity of porcine small intestinal submucosa (SIS Wound Matrix [SISWM], USP) and oxidized regenerated cellulose/collagen (ORC).
METHODS
Bioactivity was assessed in vitro as the ability to stimulate neurite outgrowth in rat pheochromocytoma (PC12) cells, proliferation of human fibroblasts, secretion of vascular endothelial growth factor (VEGF) from human fibroblasts, and in an in vivo angiogenesis model. In the angiogenesis model, SISWM and ORC were implanted subcutaneously into the mice, and vessel ingrowth was assessed at day 21 after implantation using fluorescence microangiography and histology.
METHODS
The change in cellular differentiation, proliferation, growth factor secretion, and angiogenesis over the negative control was measured after exposure to SISWM or ORC.
RESULTS
SISWM increased neurite outgrowth in PC12 cells by approximately 22% over negative controls and induced proliferation in 50.8% of human fibroblasts. These increases were comparable to positive controls. ORC was not active in either of these assays. SISWM also stimulated fibroblast VEGF secretion to a greater extent (422.4 pg/mL) than ORC (4.2 pg/mL) (P < .001). At 21 days, fluorescence microangiography showed dense infiltration of blood vessels in the SISWM that extended approximately 3 mm from the edge of the disc. In contrast, the ORC implant showed blood vessel incursion less than 1 mm from the edge of the disc, and it dissolved in the site.
CONCLUSIONS
SISWM shows much greater bioactivity than ORC. This is likely related to its close structural and biochemical approximation to natural dermal extracellular matrix and may help explain the strong clinical successes of SISWM.
Publication
Journal: British Journal of Pharmacology
July/27/2015
Abstract
OBJECTIVE
The haematopoietic activity of erythropoietin (EPO) is mediated by the classic EPO receptor (EpoR) homodimer, whereas tissue-protective effects are mediated by a heterocomplex between EpoR and the β-common receptor (βcR). Here, we investigated the effects of a novel, selective ligand of this heterocomplex - pyroglutamate helix B surface peptide (pHBSP) - in mice fed a diet enriched in sugars and saturated fats.
METHODS
Male C57BL/6J mice were fed a high-fat high-sucrose diet (HFHS) for <em>22</em> weeks. pHBSP (30 μg·kg(-1) s.c.) was administered for the last 11 weeks. Biochemical assays, histopathological and immunohistochemical examinations and Western blotting were performed on serum and target organs (liver, kidney and skeletal muscle).
RESULTS
Mice fed with HFHS diet exhibited insulin resistance, hyperlipidaemia, hepatic lipid accumulation and kidney dysfunction. In gastrocnemius muscle, HFHS impaired the insulin signalling pathway and reduced membrane translocation of glucose transporter type 4 and glycogen content. Treatment with pHBSP ameliorated renal function, reduced hepatic lipid deposition, and normalized serum glucose and lipid profiles. These effects were associated with an improvement in insulin sensitivity and glucose uptake in skeletal muscle. Diet-induced overproduction of the myokines IL-6 and fibroblast growth factor-21 were attenuated by pHBSP and, most importantly, pHBSP markedly enhanced mitochondrial biogenesis in skeletal muscle.
CONCLUSIONS
Chronic treatment of mice with an EPO derivative, devoid of haematopoietic effects, improved metabolic abnormalities induced by a high-fat high-sucrose diet, by affecting several levels of the insulin signalling and inflammatory cascades within skeletal muscle, while enhancing mitochondrial biogenesis.
Publication
Journal: AIDS
March/5/1998
Abstract
BACKGROUND
The growth of Kaposi's sarcoma (KS) spindle cells is dependent on a number of inflammatory cytokines as well as the autocrine growth factor, basic fibroblast growth factor (bFGF). Moreover, inflammatory cytokines, found at increased levels in KS lesions, promote bFGF production in KS and endothelial cells.
OBJECTIVE
To determine the induction of bFGF isoforms, role of bFGF in cell growth and activation of the bFGF promoter by inflammatory cytokines.
METHODS
3H-Thymidine uptake, bFGF immunoblotting and transfection of dominant-negative MAP kinase components were used to study the effect of cytokines on the bFGF promoter, bFGF isoform expression and proliferation of KS cells.
RESULTS
Treatment with oncostatin M (OSM), interleukin (IL)-1 and tumor necrosis factor (TNF)-alpha induced the expression of 18, 22 and 24 kDa bFGF isoforms in KS and human umbilical vein endothelial cells (HUVEC). Antisense bFGF oligonucleotides interfered in the induction of KS cell proliferation by individual cytokines. OSM, IL-1 and TNF-alpha induced the transcriptional activation of a bFGF promoter reporter gene in parallel with the activation of an AP-1 reporter. Dominant-negative ERK and dominant-negative JNK mutants interfered in cytokine-induced activation of these reporters in accordance with the role of the MAP kinase cascades in individual cytokine signaling pathways.
CONCLUSIONS
OSM, IL-1 and TNF-alpha induce KS cell growth by inducing the expression of various bFGF isoforms. Moreover, bFGF production by KS and HUVEC is dependent on the activation of the ERK and JNK cascades, which result in the transcriptional activation of the bFGF promoter.
Publication
Journal: PLoS ONE
September/19/2013
Abstract
BACKGROUND
Recent studies demonstrated that circulating fibroblast growth factor (FGF)-23 was associated with risk of end stage renal disease (ESRD) and mortality. This study aims to examine whether the predictive effect of FGF-23 is independent from circulating levels of tumor necrosis factor receptor 1 (TNFR1), a strong predictor of ESRD in Type 2 diabetes (T2D).
METHODS
We studied 380 patients with T2D who were followed for 8-12 years and were used previously to examine the effect of TNFR1. Baseline plasma FGF-23 was measured by immunoassay.
RESULTS
During follow-up, 48 patients (13%) developed ESRD and 83 patients (22%) died without ESRD. In a univariate analysis, baseline circulating levels of FGF-23 and TNFR1 were significantly higher in subjects who subsequently developed ESRD or died without ESRD than in those who remained alive. In a Cox proportional hazard model, baseline concentration of FGF-23 was associated with increased risk of ESRD, however its effect was no longer significant after controlling for TNFR1 and other clinical characteristics (HR 1.3, p = 0.15). The strong effect of circulating level of TNFR1 on risk of ESRD was not changed by including circulating levels of FGF-23 (HR 8.7, p<0.001). In the Cox multivariate model, circulating levels of FGF-23 remained a significant independent predictor of all-cause mortality unrelated to ESRD (HR 1.5, p<0.001).
CONCLUSIONS
We demonstrated that the effect of circulating levels of FGF-23 on the risk of ESRD is accounted for by circulating levels of TNFR1. We confirmed that circulating levels of FGF-23 have an independent effect on all-cause mortality in T2D.
Publication
Journal: Frontiers in Cellular Neuroscience
April/25/2013
Abstract
In the developing hippocampus, <em>fibroblast</em> <em>growth</em> <em>factor</em> (FGF) <em>22</em> promotes the formation of excitatory presynaptic terminals. Remarkably, FGF<em>22</em> knockout (KO) mice show resistance to generalized seizures in adults as assessed by chemical kindling, a model that is widely used to study epileptogenesis (Terauchi et al., 2010). Repeated injections of low dose pentylenetetrazol (PTZ) induce generalized seizures ("kindled") in wild type (WT) mice. With additional PTZ injections, FGF<em>22</em>KO mice do show moderate seizures, but they do not kindle. Thus, analyses of how FGF<em>22</em> impacts seizure susceptibility will contribute to the better understanding of the molecular and cellular mechanisms of epileptogenesis. To decipher the roles of FGF<em>22</em> in the seizure phenotype, we examine four pathophysiological changes in the hippocampus associated with epileptogenesis: enhancement of dentate neurogenesis, hilar ectopic dentate granule cells (DGCs), increase in hilar cell death, and formation of mossy fiber sprouting (MFS). Dentate neurogenesis is enhanced, hilar ectopic DGCs appeared, and hilar cell death is increased in PTZ-kindled WT mice relative to PBS-injected WT mice. Even in WT mice with fewer PTZ injections, which showed only mild seizures (so were not kindled), neurogenesis, hilar ectopic DGCs, and hilar cell death are increased, suggesting that mild seizures are enough to induce these changes in WT mice. In contrast, PTZ-injected FGF<em>22</em>KO mice do not show these changes despite having moderate seizures: neurogenesis is rather suppressed, hilar ectopic DGCs do not appear, and hilar cell death is unchanged in PTZ-injected FGF<em>22</em>KO mice relative to PBS-injected FGF<em>22</em>KO mice. These results indicate that FGF<em>22</em> plays important roles in controlling neurogenesis, ectopic migration of DGCs, and hilar cell death after seizures, which may contribute to the generalized seizure-resistant phenotype of FGF<em>22</em>KO mice and suggests a possibility that inhibition of FGF<em>22</em> may alleviate epileptogenesis.
Publication
Journal: Genesis
August/28/2000
Abstract
The developing metanephric kidney is a convenient model to study molecular events associated with epithelial cell differentiation. To determine the genes involved in the defining event of this process, namely, the conversion of metanephric mesenchyme to the epithelium of the nephron, we applied differential display (DD) techniques. Explants of rat metanephric mesenchymes were induced to condense ex vivo with <em>fibroblast</em> <em>growth</em> <em>factor</em> 2 (FGF2) or to form tubules with FGF2 and conditioned medium (CM) from a cell line (RUB1) of ureteric bud, the renal inductive tissue. Three time points (6, 24, and 72 h) were chosen to track the dynamics of gene expression during morphogenesis. Seventy-two up- or down-regulated mRNAs were identified, including 36 novel sequences and those of cell cycle regulatory proteins (TGF-beta2, Cyclin D1, p57Kip2), transcription <em>factors</em> (beta-catenin, Sox11, DP1), signaling proteins (SH3-domain binding protein, G-protein-coupled receptor, Ser-Thr protein kinase), cell adhesion molecules (syndecan-4, integrin-beta1), and also gene33, H19, SM20, IGFBP5, MAMA receptor, lectin, keratin, beta-tubulin, calreticulin, GRP78, ERp72, MnSoD, thioredoxin, and others. Some have previously been associated with kidney development and serve as good controls for expected changes, while most have not been linked with kidney epithelial cell differentiation. Using thin sections of embryonic kidney and labeled antisense RNA probes, we applied RNA hybridization to confirm the results of DD and related the expression of these genes to specific cell lineages of the developing kidney. These results provide a window into the events that mediate this critical differentiation process and suggest that a limited number of interrelated events direct the epithelial conversion of metanephric mesenchyme. genesis 27:<em>22</em>-31, 2000. Published 2000 Wiley-Liss, Inc.
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Publication
Journal: Journal of Thoracic Oncology
January/19/2015
Abstract
BACKGROUND
There remains a significant therapeutic need for small-cell lung cancer (SCLC). We and others have reported high frequency of copy number gains in cytogenetic bands encoding fibroblast growth factor receptor 1 (FGFR1) in SCLC tumors and cell lines.
METHODS
Thirteen SCLC cell lines and 68 SCLC patient tumor samples were studied for FGFR1 amplification. Growth inhibition assays were performed using PD173074, a pan-FGFR inhibitor to determine the correlation between FGFR1 expression and drug sensitivity.
RESULTS
We did not detect FGFR1 mutations in SCLC cell lines. Focal amplification of FGFR1 gene was found in five tumor samples (7%), with high-level focal amplification in only one tumor sample (1%). Amplification owing to polysomy of chromosome 8, where FGFR1 locates, was observed in 22 tumor samples (32%). There was no correlation between FGFR1 gene copy number and messenger RNA expression or protein expression in SCLC cells. FGFR inhibitor sensitivity correlated with FGFR1 copy number determined by real-time polymerase chain reaction assay (r= -0.79; p = 0.01).
CONCLUSIONS
FGFR1 gene mutations and focal amplification are rare in SCLC, but polysomy of chromosome 8 is relatively common. FGFR1 copy number gain predicts sensitivity to FGFR inhibition, and FGFR expression correlates inversely with chemosensitivity.
Publication
Journal: Hemodialysis international. International Symposium on Home Hemodialysis
September/3/2014
Abstract
Although cognitive impairment is common in hemodialysis patients, the etiology of and risk <em>factors</em> for its development remain unclear. <em>Fibroblast</em> <em>growth</em> <em>factor</em> 23 (FGF-23) levels are elevated in hemodialysis patients and are associated with increased mortality and left ventricular hypertrophy. Despite FGF-23 being found within the brain, there are no prior studies assessing whether FGF-23 levels are associated with cognitive performance. We measured FGF-23 in 263 prevalent hemodialysis patients in whom comprehensive neurocognitive testing was also performed. The cross-sectional association between patient characteristics and FGF-23 levels was assessed. Principal <em>factor</em> analysis was used to derive two <em>factors</em> from cognitive test scores, representing memory and executive function, which carried a mean of 0 and a standard deviation of 1. Multivariable linear regression adjusting for age, sex, education status, and other relevant covariates was used to explore the relationship between FGF-23 and each <em>factor</em>. Mean age was 63 years, 46% were women and <em>22</em>% were African American. The median FGF-23 level was 3098 RU/mL. Younger age, lower prevalence of diabetes, longer dialysis vintage, and higher calcium and phosphorus were independently associated with higher FGF-23 levels. Higher FGF-23 was independently associated with a lower memory score (per doubling of FGF-23, β = -0.08 SD [95% confidence interval, CI: -0.16, -0.01]) and highest quartile vs. lowest quartile (β = -0.42 SD [-0.82, -0.02]). There was no definite association of FGF 23 with executive function when examined as a continuous variable (β = -0.03 SD [-0.10, 0.04]); however, there was a trend in the quartile analysis (β = -0.28 SD [-0.63, 0.07], P = 0.13, for 4th quartile vs. 1st quartile). FGF-23 was associated with worse performance on a composite memory score, including after adjustment for measures of mineral metabolism. High FGF-23 levels in hemodialysis patients may contribute to cognitive impairment.
Publication
Journal: Frontiers in Immunology
August/15/2017
Abstract
Tumor necrosis <em>factor</em> (TNF)-like weak inducer of apoptosis (TWEAK) binds to its sole receptor <em>fibroblast</em> <em>growth</em> <em>factor</em>-inducible 14 (Fn14), participating in various inflammatory responses. Recently, TWEAK/Fn14 activation was found prominent in the lesions of cutaneous lupus erythematosus (CLE). This study was designed to further reveal the potential role of this pathway in Ro52-mediated photosensitization. TWEAK, Fn14, and Ro52 were determined in the skin lesions of patients with CLE. Murine keratinocytes received ultraviolet B (UVB) irradiation or plus TWEAK stimulation and underwent detection for Ro52 and proinflammatory cytokines. The chemotaxis of J774.2 macrophages was evaluated on TWEAK stimulation of cocultured keratinocytes. We found that TWEAK, Fn14, and downstream cytokines were highly expressed in CLE lesions that overexpressed Ro52. Moreover, TWEAK enhanced the UVB-induced Ro52 upregulation in murine keratinocytes. Meanwhile, TWEAK stimulation of keratinocytes favored the migration of macrophages through promoting the production of chemokine C-C motif ligands 17 and <em>22</em>. Furthermore, Fn14 siRNA transfection or nuclear <em>factor</em>-kappa B (NF-κB) inhibitor abrogated the TWEAK enhancement of Ro52 expression in keratinocytes. Similarly, TNF receptor associated <em>factor</em> 2 (TRAF2) siRNA reduced the protein level of Ro52 in these cells upon TWEAK stimulation. Interestingly, UVB irradiation increased the expression of TNF receptor type 1 (TNFR1) but not affecting TNFR2 expression in keratinocytes. In conclusion, the TWEAK/Fn14 signaling participates in Ro52-mediated photosensitization and involves the activation of NF-κB pathway as well as the function of the TRAF2/TNFR partners.
Publication
Journal: Results and Problems in Cell Differentiation
July/25/2017
Abstract
Polycystic kidney disease (PKD) is a commonly inherited disorder characterized by cyst formation and fibrosis (Wilson, N Engl J Med 350:151-164, 2004) and is caused by mutations in cilia or cilia-related proteins, such as polycystin 1 or 2 (Oh and Katsanis, Development 139:443-448, 2012; Kotsis et al., Nephrol Dial Transplant 28:518-526, 2013). A major pathological feature of PKD is the development of interstitial inflammation and fibrosis with an associated accumulation of inflammatory cells (Grantham, N Engl J Med 359:1477-1485, 2008; Zeier et al., Kidney Int 42:1259-1265, 1992; Ibrahim, Sci World J 7:1757-1767, 2007). It is unclear whether inflammation is a driving force for cyst formation or a consequence of the pathology (Ta et al., Nephrology 18:317-330, 2013) as in some murine models cysts are present prior to the increase in inflammatory cells (Phillips et al., Kidney Blood Press Res 30:129-144, 2007; Takahashi et al., J Am Soc Nephrol JASN 1:980-989, 1991), while in other models the increase in inflammatory cells is present prior to or coincident with cyst initiation (Cowley et al., Kidney Int 43:5<em>22</em>-534, 1993, Kidney Int 60:2087-2096, 2001). Additional support for inflammation as an important contributor to cystic kidney disease is the increased expression of many pro-inflammatory cytokines in murine models and human patients with cystic kidney disease (Karihaloo et al., J Am Soc Nephrol JASN <em>22</em>:1809-1814, 2011; Swenson-Fields et al., Kidney Int, 2013; Li et al., Nat Med 14:863-868, 2008a). Based on these data, an emerging model in the field is that disruption of primary cilia on tubule epithelial cells leads to abnormal cytokine cross talk between the epithelium and the inflammatory cells contributing to cyst <em>growth</em> and fibrosis (Ta et al., Nephrology 18:317-330, 2013). These cytokines are produced by interstitial <em>fibroblasts</em>, inflammatory cells, and tubule epithelial cells and activate multiple pathways including the JAK-STAT and NF-κB signaling (Qin et al., J Am Soc Nephrol JASN 23:1309-1318, 2012; Park et al., Am J Nephrol 32:169-178, 2010; Bhunia et al., Cell 109:157-168, 2002). Indeed, inflammatory cells are responsible for producing several of the pro-fibrotic <em>growth</em> <em>factors</em> observed in PKD patients with fibrosis (Nakamura et al., Am J Nephrol 20:32-36, 2000; Wilson et al., J Cell Physiol 150:360-369, 1992; Song et al., Hum Mol Genet 18:2328-2343, 2009; Schieren et al., Nephrol Dial Transplant 21:1816-1824, 2006). These <em>growth</em> <em>factors</em> trigger epithelial cell proliferation and myofibroblast activation that stimulate the production of extracellular matrix (ECM) genes including collagen types 1 and 3 and fibronectin, leading to reduced glomerular function with approximately 50% of ADPKD patients progressing to end-stage renal disease (ESRD). Therefore, treatments designed to reduce inflammation and slow the rate of fibrosis are becoming important targets that hold promise to improve patient life span and quality of life. In fact, recent studies in several PKD mouse models indicate that depletion of macrophages reduces cyst severity. In this chapter, we review the potential mechanisms of interstitial inflammation in PKD with a focus on ADPKD and discuss the role of interstitial inflammation in progression to fibrosis and ESRD.
Publication
Journal: Journal of Clinical Oncology
October/18/2019
Abstract
<AbstractText>Bevacizumab treatment at 7.5 mg/kg every 3 weeks results in improved hearing in approximately 35%-40% of patients with neurofibromatosis type 2 (NF2) and progressive vestibular schwannomas (VSs). However, the optimal dose is unknown. In this multicenter phase II and biomarker study, we evaluated the efficacy and safety of high-dose bevacizumab in pediatric and adult patients with NF2 with progressive VS.</AbstractText><AbstractText>Bevacizumab was given for 6 months at 10 mg/kg every 2 weeks, followed by 18 months at 5 mg/kg every 3 weeks. The primary end point was hearing response defined by word recognition score (WRS) at 6 months. Secondary end points included toxicity, radiographic response, quality of life (QOL), and plasma biomarkers.</AbstractText><p><div><b>RESULTS</b></div>Twenty-two participants with NF2 (median age, 23 years) with progressive hearing loss in the target ear (median baseline WRS, 53%) were enrolled. Nine (41%) of <em>22</em> participants achieved a hearing response at 6 months (1 of 7 children and 8 of 15 adults; <i>P</i> = .08). Radiographic response was seen in 7 (32%) of <em>22</em> patients with VS at 6 months (7 of 15 adults and 0 of 7 children; <i>P</i> = .05). Common mild to moderate adverse events included hypertension, fatigue, headache, and irregular menstruation. Improvement in NF2-related QOL and reduction in tinnitus-related distress were reported in 30% and 60% of participants, respectively. Paradoxically, high-dose bevacizumab treatment was not associated with a significant decrease in free vascular endothelial <em>growth</em> <em>factor</em> but was associated with increased carbonic anhydrase IX, hepatocyte <em>growth</em> <em>factor</em>, placental <em>growth</em> <em>factor</em>, stromal cell-derived <em>factor</em> 1α, and basic <em>fibroblast</em> <em>growth</em> <em>factor</em> concentrations in plasma.</p><AbstractText>High-dose bevacizumab seems to be no more effective than standard-dose bevacizumab for treatment of patients with NF2 with hearing loss. In contrast to adults, pediatric participants did not experience tumor shrinkage. However, adult and pediatric participants reported similar improvement in QOL during induction. Novel approaches using bevacizumab should be considered for children with NF2.</AbstractText>
Publication
Journal: Scandinavian Journal of Medicine and Science in Sports
July/5/2015
Abstract
Calcium and phosphate are essential for cell functions, and their serum concentrations result from the balance between intestinal absorption, bony storage, and urinary excretion. <em>Fibroblast</em> <em>growth</em> <em>factor</em> 23 (FGF23), expressed by osteocytes and osteoblasts, acts in the kidney, leading to hypophosphatemia and low 1,25-dihydroxycholecalciferol synthesis, but suppresses parathyroid function. The aim of this study was to explore the effects of a high-energy demanding cycling race on this bone-kidney-parathyroid axis. We studied nine cyclists during the 2011 Giro d'Italia stage race. Pre-analytical and analytical phases followed academic and anti-doping recommendations. Serum parathyroid hormone (PTH), 25(OH)D, total calcium, inorganic phosphorus, and plasma FGF23 were measured on days -1, 12, and <em>22</em> and corrected for changes in plasma volume. Dietary calcium and phosphorus, anthropometric parameters (height, weight, and body mass index) and indexes of metabolic effort (net energy expenditure, power output) were recorded. Dietary calcium and phosphorus intakes were kept at the same levels throughout the race. Twenty-five (OH)D, PTH, and calcium concentrations remained stable. FGF23 increased 50% with a positive correlation with the indexes of metabolic effort and, consequently, phosphorous decreased, although only in the first half. The strong metabolic effort acts on the bone-kidney-parathyroid system, and the rise in FGF23 plasma concentration might be aimed at maintaining calcium and phosphorus homeostasis.
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