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Publication
Journal: Therapeutic Advances in Gastroenterology
July/13/2011
Abstract
Bowel symptoms including diarrhoea can be produced when excess bile acids (BA) are present in the colon. This condition, known as bile acid or bile salt malabsorption, has been under recognized, as the best diagnostic method, the (75)Se-homocholic acid taurine (SeHCAT) test, is not available in many countries and is not fully utilized in others. Reduced SeHCAT retention establishes that this is a complication of many other gastrointestinal diseases. Repeated studies show SeHCAT tests are abnormal in about 30% of patients otherwise diagnosed as diarrhoea-predominant irritable bowel syndrome or functional diarrhoea, with an estimated population prevalence of around 1%. Recent work suggests that the condition previously called idiopathic bile acid malabsorption (BAM) is not in fact due to a defect in absorption, but results from an overproduction of BA because of defective feedback inhibition of hepatic bile acid synthesis, a function of the ileal hormone <em>fibroblast</em> <em>growth</em> <em>factor</em> <em>19</em> (FGF<em>19</em>). The approach to treatment currently depends on binding excess BA, to reduce their secretory actions, using colestyramine, colestipol and, most recently, colesevelam. Colesevelam has a number of potential advantages that merit further investigation in trials directed at patients with bile acid diarrhoea.
Publication
Journal: Blood
April/25/2001
Abstract
Disruption of the RAS-to-mitogen-activated protein kinase (MAPK/ERK) signaling pathway, either directly through activating RAS gene mutations or indirectly through other genetic aberrations, plays an important role in the molecular pathogenesis of myeloid leukemias. Constitutive activation of ERK-1/2 and MEK-1/2, which elicit oncogenic transformation in <em>fibroblasts</em>, has recently been observed in acute myeloid leukemias (AML). In this study, the activation of the RAS-to-MAPK cascade in 14 AML and 5 chronic myeloid leukemia (CML) cell lines is examined and correlated with the effects of a panel of 9 RAS signaling inhibitors on cell viability, colony formation, cell-cycle progression, and induction of apoptosis. Activation of MEK, ERK, and the transcription <em>factors</em> CREB-1, ATF-1, and c-Myc is demonstrated in the majority of the cell lines (9 of 14 AML and 2 of 5 CML cell lines). Although activation of the ERK cascade did not always correlate with the presence of activating RAS mutations or BCR-Abl, it is linked to the G0/G1 and the G2/M phase of the cell cycle. In contrast to most inhibitors (eg, B581, Cys-4-Abs-Met, FPT-2, FTI-276, and FTS), a significant <em>growth</em> inhibition was only observed for FTI-277 (<em>19</em> of <em>19</em>), FPT-3 (10 of <em>19</em>), and the MEK inhibitors U0126 (<em>19</em> of <em>19</em>) and PD098059 (8 of <em>19</em>). Treatment of NB-4 cells with FTI-277 primarily resulted in a G2/M block, whereas treatment with FPT-3 and U0126 led to induction of apoptosis. FTI-277 revealed strong toxicity toward normal purified CD34+ cells. The results suggest differences in the mechanisms of action and support a potential therapeutic usefulness of these inhibitors in the treatment of myeloid leukemias.
Publication
Journal: Biochimica et Biophysica Acta - General Subjects
February/1/2009
Abstract
BACKGROUND
Many fibroblast growth factor family proteins (FGFs) bind to the heparan sulfate/heparin (HP) subtypes of sulfated glycosaminoglycans (GAGs), and a few have recently been reported to also interact with chondroitin sulfate (CS), another sulfated GAG subtype.
METHODS
To gain additional insight into this interaction, we prepared all currently known FGFs (i.e., FGF1-FGF23) and assessed their affinity for HP, CS-B, CS-D and CS-E. In addition, midkine, hepatocyte growth factor and pleiotrophin were studied as other known HP-binding proteins.
RESULTS
We found that members of the FGF19 subfamily (i.e., FGF15, 19, 21 and 23) had little or no affinity for HP; all of the other secretable growth factors tested had strong affinities for HP, as was indicated by the finding that their elution from HP-Sepharose columns required 1.0-1.5 M NaCl. We also found that FGF3, 6, 8 and 22 had strong affinities for CS-E, while FGF5 had a moderate affinity for CS-D. The interactions between FGFs and GAGs thus appear to be more diverse than previously understood.
CONCLUSIONS
This is noteworthy, as the differential interactions of these growth factors with GAGs may be key determinants of their specific biological activities.
Publication
Journal: The Lancet Oncology
May/19/2016
Abstract
BACKGROUND
Angiogenesis is a target in the treatment of ovarian cancer. Nintedanib, an oral triple angiokinase inhibitor of VEGF receptor, platelet-derived growth factor receptor, and fibroblast growth factor receptor, has shown activity in phase 2 trials in this setting. We investigated the combination of nintedanib with standard carboplatin and paclitaxel chemotherapy in patients with newly diagnosed advanced ovarian cancer.
METHODS
In this double-blind phase 3 trial, chemotherapy-naive patients (aged 18 years or older) with International Federation of Gynecology and Obstetrics (FIGO) IIB-IV ovarian cancer and upfront debulking surgery were stratified by postoperative resection status, FIGO stage, and planned carboplatin dose. Patients were randomly assigned (2:1) via an interactive voice or web-based response system to receive six cycles of carboplatin (AUC 5 mg/mL per min or 6 mg/mL per min) and paclitaxel (175 mg/m(2)) in addition to either 200 mg of nintedanib (nintedanib group) or placebo (placebo group) twice daily on days 2-21 of every 3-week cycle for up to 120 weeks. Patients, investigators, and independent radiological reviewers were masked to treatment allocation. The primary endpoint was investigator-assessed progression-free survival analysed in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, number NCT01015118.
RESULTS
Between Dec 9, 2009, and July 27, 2011, 1503 patients were screened and 1366 randomly assigned by nine study groups in 22 countries: 911 to the nintedanib group and 455 to the placebo group. 486 (53%) of 911 patients in the nintedanib group experienced disease progression or death compared with 266 (58%) of 455 in the placebo group. Median progression-free survival was significantly longer in the nintedanib group than in the placebo group (17·2 months [95% CI 16·6-19·9] vs 16·6 months [13·9-19·1]; hazard ratio 0·84 [95% CI 0·72-0·98]; p=0·024). The most common adverse events were gastrointestinal (diarrhoea: nintedanib group 191 [21%] of 902 grade 3 and three [<1%] grade 4 vs placebo group nine [2%] of 450 grade 3 only) and haematological (neutropenia: nintedanib group 180 [20%] grade 3 and 200 (22%) grade 4 vs placebo group 90 [20%] grade 3 and 72 [16%] grade 4; thrombocytopenia: 105 [12%] and 55 [6%] vs 21 [5%] and eight [2%]; anaemia: 108 [12%] and 13 [1%] vs 26 [6%] and five [1%]). Serious adverse events were reported in 376 (42%) of 902 patients in the nintedanib group and 155 (34%) of 450 in the placebo group. 29 (3%) of 902 patients in the nintedanib group experienced serious adverse events associated with death compared with 16 (4%) of 450 in the placebo group, including 12 (1%) in the nintedanib group and six (1%) in the placebo group with a malignant neoplasm progression classified as an adverse event by the investigator. Drug-related adverse events leading to death occurred in three patients in the nintedanib group (one without diagnosis of cause; one due to non-drug-related sepsis associated with drug-related diarrhoea and renal failure; and one due to peritonitis) and in one patient in the placebo group (cause unknown).
CONCLUSIONS
Nintedanib in combination with carboplatin and paclitaxel is an active first-line treatment that significantly increases progression-free survival for women with advanced ovarian cancer, but is associated with more gastrointestinal adverse events. Future studies should focus on improving patient selection and optimisation of tolerability.
BACKGROUND
Boehringer Ingelheim.
Publication
Journal: Journal of Internal Medicine
January/11/2012
Abstract
BACKGROUND
Bile acid (BA) synthesis is essential in cholesterol and lipid homoeostasis.
METHODS
Serum samples from 435 normal and 23 cholecystectomized subjects were obtained after overnight fasting and assayed for markers of BA and cholesterol synthesis, as well as cholesterol absorption. We determined whether BA synthesis was related to <em>fibroblast</em> <em>growth</em> <em>factor</em> <em>19</em> (FGF<em>19</em>; a circulating metabolic regulator that is thought to inhibit BA synthesis), gender, age and serum lipids.
RESULTS
Bile acid synthesis varied more than 9-fold in normal individuals and was 29% higher in men than in women. Whilst low-density lipoprotein cholesterol increased with age, BA and cholesterol synthesis were stable. BA production was positively correlated with serum triglycerides (TGs), and 35% of individuals with a high level (>95th percentile) of BA synthesis had hypertriglyceridaemia (HTG) (>95th percentile). Serum FGF<em>19</em> levels varied by 7-fold in normal individuals and were related inversely to BA synthesis but were not related to gender, plasma lipids or history of cholecystectomy.
CONCLUSIONS
Bile acid synthesis has a wide inter-individual variation, is lower in women than in men and is correlated positively with serum TGs. High BA production is frequently linked to HTG. Age-related hypercholesterolaemia is not associated with changes in BA or cholesterol production, nor to an increase in cholesterol absorption. In humans, the circulating level of FGF<em>19</em> may regulate hepatic BA production under fasting conditions.
Publication
Journal: Lupus
September/8/2010
Abstract
Systemic lupus erythematosus (SLE) has been considered as stem cell disorder. The objective of this study was to examine the phenotype, <em>growth</em> and immunomodulatory effect of mesenchymal stem cells (MSCs) from SLE patients compared with those from age- and sex-matched healthy donors. MSCs were expanded from bone marrow aspirate and were examined for morphological appearance, quantified in different passages to determine <em>growth</em> rate and evaluated for ability of adipogenesis and osteogenesis. Telomerase activity was measured by telomerase repeat amplification protocol. The immunomodulatory effect of MSCs was evaluated by mixed lymphocyte reaction. MSCs from SLE patients were found to be bigger and flattened in appearance after passage 3 and demonstrated slower <em>growth</em> rate compared with <em>fibroblast</em>-like MSCs from normal controls. These cells were not able to reach confluence after passage 4. Telomerase activity was upregulated in five SLE patients mostly with active disease compared with two with negative expression with lesser activity. MSCs from SLE patients were, otherwise, comparable to normal controls in terms of their surface marker (CD73, CD90 and CD105) expression and extent of suppression on proliferation of allogeneic T lymphocytes. In conclusion, MSCs from SLE demonstrated early signs of senescence which may be a corollary of active lupus or a contributory <em>factor</em> to disease pathogenesis. Lupus (2010) <em>19</em>, 850-859.
Publication
Journal: Cardiovascular Research
February/12/1998
Abstract
OBJECTIVE
We have shown that basic fibroblast growth factor (bFGF/FGF-2) enhances myocardial collateral development in a canine model of progressive coronary occlusion when delivered via the left atrial or intracoronary routes; however, we have found intravenous bFGF ineffective in the same model. Data on the fate and efficacy of intravenous bFGF are limited. We hypothesized that first pass lung uptake might limit myocardial bFGF availability after intravenous injection. We postulated that delivery of bFGF through the distal port of a wedged Swan Ganz catheter might circumvent this problem by restricting exposure of bFGF to a limited number of pulmonary binding sites. This study evaluated differential regional uptake of 125I labeled bFGF following bolus intravenous, Swan Ganz, left atrial, intracoronary, and pericardial delivery.
METHODS
Mongrel dogs were used. Human recombinant bFGF, monoiodinated with 125I, was mixed with cold bFGF to a specific activity of 0.03 microCi/microgram. Approximately 100 micrograms/kg was injected per animal by the intravenous, left atrial, Swan Ganz, intracoronary, or pericardial route. Dogs were killed 15 min or 150 min later. The heart, lungs, liver, spleen, and kidneys were harvested and 125I activity was assessed. Immunohistochemical and pharmacokinetic studies were also performed.
RESULTS
Serum half life of bFGF was comparable after intracoronary, intravenous and left atrial delivery (50 min); however, there were significant differences with regard to pharmacodynamics. After intracoronary administration, 3-5% of the total bFGF dose was recovered from the heart, with the peptide immunolocalized to the extracellular matrix and vascular endothelium. In contrast, only 1.3% of the injected bFGF was localized to the heart after left atrial administration and 0.5% was recovered after intravenous or Swan Ganz delivery. Pericardial administration resulted in substantial cardiac bFGF delivery; 19% was present at 150 min. Myocardial uptake was similar with Swan Ganz and intravenous delivery, suggesting that the administered dose did not saturate available pulmonary binding sites.
CONCLUSIONS
These data predict efficacy of intracoronary, left atrial, and pericardial bFGF for myocardial angiogenesis, and a lack of efficacy after bolus intravenous and Swan Ganz administration.
Publication
Journal: American Journal of Physiology - Gastrointestinal and Liver Physiology
January/5/2009
Abstract
beta-Klotho, a newly described membrane protein, regulates bile acid synthesis. <em>Fibroblast</em> <em>growth</em> <em>factor</em>-15 (FGF-15) and FGF receptor-4 (FGFR4) knockout mice share a similar phenotype with beta-Klotho-deficient mice. FGF-15 secretion by the intestine regulates hepatic bile acid biosynthesis. The effects of beta-Klotho and FGF-15 on the ileal apical sodium bile transporter (ASBT) are unknown. beta-Klotho siRNA treatment of the mouse colon cancer cell line, CT-26, and the human intrahepatic biliary epithelial cells (HIBEC) resulted in upregulation of endogenous ASBT expression that was associated with reduced expression of the farnesoid X receptor (FXR) and the short heterodimer partner (SHP). Silencing beta-Klotho activated the ASBT promoter in CT-26, Mz-ChA-1 (human cholangiocarcinoma), and HIBEC cells. Site-directed mutagenesis of liver receptor homolog-1 (mouse) or retinoic acid receptor/retinoid X receptor (RAR/RXR) (human) cis-elements attenuated the basal activity of the ASBT promoter and abrogated its response to beta-Klotho silencing. siSHP, siFXR, or dominant-negative FXR treatment also eliminated the beta-Klotho response. FGF-15 secretion into cell culture media by CT-26 cells was diminished after siFGF-15 or sibeta-Klotho treatment and enhanced by chenodeoxycholic acid. Exogenous FGF-<em>19</em> repressed ASBT protein expression in mouse ileum, gallbladder, and in HIBEC and repressed ASBT promoter activity in Caco-2, HIBEC, and Mz-ChA-1 cells. Promoter repression was dependent on the expression of FGFR4. These results indicate that both beta-Klotho and FGF-15/<em>19</em> repress ASBT in enterocytes and cholangiocytes. These novel signaling pathways need to be considered in analyzing bile acid homeostasis.
Publication
Journal: Clinical Cancer Research
January/5/2004
Abstract
OBJECTIVE
The purpose is to analyze the possible correlation between expression and activation of the high-affinity nerve growth factor (NGF) receptor TrkA, cell cycle protein expression, and disease outcome in serous ovarian carcinoma. In addition, we wished to study the possible link between expression of NGF, a novel angiogenic factor and its receptor TrkA, and the expression of factors involved in angiogenesis in effusions and solid tumors.
METHODS
Sections from 80 malignant effusions and 65 corresponding solid tumors were evaluated for protein expression of NGF, TrkA, and phospho-TrkA (p-TrkA). Effusions were additionally studied for expression of p53, p21(WAF1/CIP1), Ki-67, and the M(r) 85,000-cleaved fragment of poly(ADP-ribose) polymerase (p85-PARP) using immunohistochemistry (IHC). Thirty-two effusions were studied for TrkA, p-TrkA, p53, and p21(WAF1/CIP1) expression using immunoblotting. mRNA expression of basic fibroblast growth factor (bFGF), interleukin 8, and vascular endothelial growth factor (VEGF) was studied in 63 effusions and all solid tumors using in situ hybridization. Protein expression of bFGF, interleukin 8, and VEGF was additionally studied in 30 effusions using IHC.
RESULTS
NGF, TrkA, and p-TrkA were expressed in carcinoma cells in effusions in 60 of 80 (75%), 64 of 80 (80%), and 15 of 80 (19%) specimens, respectively. In solid tumors, p-TrkA expression was more frequent (52 of 65 tumors; 80%) and was accompanied by p-TrkA expression in endothelial cells. NGF colocalized with bFGF protein (P = 0.016) and mRNA (P = 0.032) in effusions, and with VEGF (P < 0.001) and bFGF (P = 0.008) in solid tumors. In survival analysis, expression of p85-PARP (P = 0.017) and cytoplasmic TrkA (P < 0.001) in effusions predicted better outcome, whereas membrane expression of p-TrkA in solid tumors correlated with poor survival (P = 0.004). Diffuse expression of p53 and Ki-67 was often seen using IHC, whereas p21(WAF1/CIP1) and p85-PARP expression was infrequent and focal. None of these correlated with NGF or TrkA expression or activity.
CONCLUSIONS
Coexpression of NGF with molecules involved in angiogenesis and p-TrkA expression in endothelial cells suggest that the proangiogenic role attributed to NGF in vitro and in vivo may be relevant in clinical cancer. Expression of p85-PARP as a marker of apoptosis and cytoplasmic expression of TrkA (probably representing nonglycosylated receptor) predict better outcome, whereas p-TrkA activation correlates with poor outcome in advanced stage serous ovarian carcinoma.
Publication
Journal: Gut
February/17/2015
Abstract
OBJECTIVE
Bile acids may play a role in the pathogenesis of IBS. We investigated the potential effects of bile acids entering the colon and its role in the symptom pattern in IBS.
METHODS
We measured 75Se-labelled homocholic acid-taurine (75SeHCAT) retention, and serum levels of 7α-hydroxy-4-cholesten-3-one (C4) and <em>fibroblast</em> <em>growth</em> <em>factor</em> (FGF) <em>19</em> in patients with IBS (n=141) and control subjects (75SeHCAT n=29; C4 and FGF<em>19</em> n=435). In patients with IBS stool frequency and form, as well as GI symptom severity were registered, and in a proportion of patients colonic transit time and rectal sensitivity were measured (n=66). An 8-week open-label treatment with colestipol was offered to patients with 75SeHCAT <20%, and the effect of treatment was evaluated with IBS severity scoring system and adequate relief of IBS symptoms.
RESULTS
Compared with controls, patients with IBS had lower 75SeHCAT values (p=0.005), higher C4c levels (C4 corrected for cholesterol) (p<0.001), but similar FGF<em>19</em> levels. Abnormal 75SeHCAT retention (<10%) was seen in 18% of patients, whereas 23% had elevated C4c levels. Patients with IBS with 75SeHCAT retention <10% had more frequent stools, accelerated colonic transit time, rectal hyposensitivity, a higher body mass index, higher C4c and lower FGF<em>19</em> levels. Colestipol treatment improved IBS symptoms (IBS severity scoring system 220±109 vs. 277±106; p<0.01), and 15/27 patients fulfilled criteria for treatment response (adequate relief ≥50% of weeks 5-8).
CONCLUSIONS
Increased colonic bile acid exposure influences bowel habit and colonic transit time in patients with IBS. A high response rate to open label treatment with colestipol supports this, but placebo-controlled studies are warranted.
Publication
Journal: Cancer Biology and Therapy
September/15/2015
Abstract
Nasopharyngeal carcinoma (NPC) is one of the most common head and neck malignancies and exhibits regional differences in incidence. Because many fusion genes have been discovered in different types of tumors over the past few years, we aimed to investigate the existence of a fusion gene in primary NPC patients using RNA-seq. In this study, for the first time, we found that <em>fibroblast</em> <em>growth</em> <em>factor</em> receptor 3-transforming acidic coiled-coil-containing protein 3 (FGFR3-TACC3) fusion transcripts are recurrently detected in NPC. The presence of this fusion gene was also detected in head and neck cancer, esophageal squamous cell carcinoma (ESCC), and lung cancer. Furthermore, we found certain new isoforms of the FGFR3-TACC3 fusion transcripts, such as a gene fusion between exon 18 of FGFR3 and exon 6 or exon 14 of TACC3 and agene fusion between exon <em>19</em> of FGFR3 and exon 11 of TACC3. In addition, we showed that the FGFR3-TACC3 fusion gene promotes cell proliferation, colony formation, and transforming ability in vitro, whereas the FGFR3-TACC3 K508M mutant or treatment with the FGFR inhibitor PD173074 abrogates these effects, suggesting that FGFR3-TACC3 most likely exerts its effects through activation of FGFR kinase activity. This activation likely leads to the development of NPC. Additionally, FGFR3-TACC3 could trigger activation of the ERK and Akt signaling pathways, whereas FGFR3-TACC3 K508M mutant could not, suggesting that these 2 signaling pathways might be involved in the function of FGFR3-TACC3. Taken together, our data demonstrated the oncogenic role of FGFR3-TACC3 in vitro, indicating that FGFR3-TACC3 may be useful as a diagnostic marker and therapeutic target in cancers.
Publication
Journal: Hepatology
February/26/2019
Abstract
NGM282, an engineered <em>fibroblast</em> <em>growth</em> <em>factor</em> <em>19</em> analogue, rapidly and significantly reduced liver fat content in a multicenter, randomized, double-blind, placebo-controlled study in patients with biopsy-confirmed nonalcoholic steatohepatitis (NASH). However, it is unclear whether these changes would be accompanied by histological improvement. In this open-label study, we assessed the histological efficacy of NGM282 in patients with biopsy-confirmed nonalcoholic steatohepatitis. Paired liver biopsies from 43 patients who received subcutaneous NGM282 (1 mg, n = 24; 3 mg, n = <em>19</em>) once daily for 12 weeks were evaluated blinded to time point, subject, and clinical information. At week 12, NGM282 significantly reduced nonalcoholic fatty liver disease activity score (NAS; -1.9; 95% confidence interval, -2.6 to -1.2; P < 0.001 in the 1 mg group; -2.2, -3.1 to -1.3; P < 0.001 in the 3 mg group) and fibrosis (-0.5; -0.9 to 0; P = 0.035 in the 3 mg group) scores. Overall, 50% and 63% of the patients receiving NGM282 1 mg or 3 mg, respectively, improved NAS by 2 or more points without fibrosis worsening. Of the patients receiving NGM282 1 mg or 3 mg, 25% and 42%, respectively, improved liver fibrosis by one stage or more without worsening of steatohepatitis. Treatment with NGM282 led to relative reductions in liver fat content (-58% and -67% in the 1 mg and 3 mg groups, respectively), corrected T1 (cT1; -8% and -9%), alanine aminotransferase (ALT) (-67% and -60%), aspartate aminotransferase (-57% and -52%), and fibrogenesis biomarkers neoepitope-specific N-terminal propeptide of type III collagen (Pro-C3; -22% and -33%) and enhanced liver fibrosis score (ELF; -3% and -6%) at week 12. Greater reductions in Pro-C3, ELF, and cT1, but not in liver fat content, 7alpha-hydroxy-4-cholesten-3-one, or ALT, were observed in histological responders than in nonresponders. Conclusion: In this open-label study, NGM282 improved the histological features of NASH in 12 weeks with significant reductions in NAS and fibrosis scores, accompanied by improvements in noninvasive imaging and serum markers.
Publication
Journal: International Journal of Molecular Sciences
October/28/2018
Abstract
Farnesoid X receptor (FXR), a metabolic nuclear receptor, plays critical roles in the maintenance of systemic energy homeostasis and the integrity of many organs, including liver and intestine. It regulates bile acid, lipid, and glucose metabolism, and contributes to inter-organ communication, in particular the enterohepatic signaling pathway, through bile acids and <em>fibroblast</em> <em>growth</em> <em>factor</em>-15/<em>19</em> (FGF-15/<em>19</em>). The metabolic effects of FXR are also involved in gut microbiota. In addition, FXR has various functions in the kidney, adipose tissue, pancreas, cardiovascular system, and tumorigenesis. Consequently, the deregulation of FXR may lead to abnormalities of specific organs and metabolic dysfunction, allowing the protein as an attractive therapeutic target for the management of liver and/or metabolic diseases. Indeed, many FXR agonists have been being developed and are under pre-clinical and clinical investigations. Although obeticholic acid (OCA) is one of the promising candidates, significant safety issues have remained. The effects of FXR modulation might be multifaceted according to tissue specificity, disease type, and/or energy status, suggesting the careful use of FXR agonists. This review summarizes the current knowledge of systemic FXR biology in various organs and the gut⁻liver axis, particularly regarding the recent advancement in these fields, and also provides pharmacological aspects of FXR modulation for rational therapeutic strategies and novel drug development.
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Publication
Journal: Journal of Biological Chemistry
November/3/1999
Abstract
The HB-<em>19</em> pseudopeptide 5[Kpsi(CH(2)N)PR]-TASP, psi(CH(2)N) for reduced peptide bond, is a specific inhibitor of human immunodeficiency virus (HIV) infection in different CD4(+) cell lines and in primary T-lymphocytes and macrophages. Here, by using an experimental CD4(+) cell model to monitor HIV entry and infection, we demonstrate that HB-<em>19</em> binds the cell surface and inhibits attachment of HIV particles to permissive cells. At concentrations that inhibit HIV attachment, HB-<em>19</em> binds cells irreversibly, becomes complexed with the cell-surface-expressed nucleolin, and eventually results in its degradation. Accordingly, by confocal immunofluorescence microscopy, we demonstrate the drastic reduction of the cell-surface-expressed nucleolin following treatment of cells with HB-<em>19</em>. HIV particles can prevent the binding of HB-<em>19</em> to cells and inhibit complex formation with nucleolin. Such a competition between viral particles and HB-<em>19</em> is consistent with the implication of nucleolin in the process of HIV attachment to target cells. We show that another inhibitor of HIV infection, the <em>fibroblast</em> <em>growth</em> <em>factor</em>-2 (FGF-2) that uses cell-surface-expressed heparan sulfate proteoglycans as low affinity receptors, binds cells and blocks attachment of HIV to permissive cells. FGF-2 does not prevent the binding of HB-<em>19</em> to cells and to nucleolin, and similarly HB-<em>19</em> has no apparent effect on the binding of FGF-2 to the cell surface. The lack of competition between these two anti-HIV agents rules out the potential involvement of heparan sulfate proteoglycans in the mechanism of anti-HIV effect of HB-<em>19</em>, thus pointing out that nucleolin is its main target.
Publication
Journal: Cerebrovascular Diseases
January/2/2003
Abstract
BACKGROUND
Trafermin (basic fibroblast growth factor) has been shown to reduce infarct volume in acute ischemic stroke models, and to promote functional recovery and new synapse formation when given to animals with completed cerebral infarction. A previous study in acute stroke patients suggested that trafermin was safe and well tolerated when given over a 3-hour period over a wide dose range.
RESULTS
Double-blind, parallel group, placebo-controlled trial of a single 24-hour intravenous infusion of trafermin. Patients having onset of stroke symptoms within 6 h and a baseline score of>>/=7 on the NIH Stroke Scale >>/=2 motor) were randomized to receive 5 or 10 mg of trafermin or placebo intravenously infused over 24 h. The primary efficacy outcome was a categorized combination of the Barthel and Rankin scales assessed at 90 days. A total of 286 patients had been enrolled at 55 sites in 11 countries when the sponsor directed that enrollment be stopped because an interim analysis of efficacy data predicted too small a chance of demonstrating a statistically significant benefit after recruitment of the planned 900 patients. The 5-mg group showed a slight but nonsignificant advantage over placebo (OR 1.2, 95% CI 0.72-2.00, p = 0.48); the 10-mg group showed a nonsignificant disadvantage (OR 0.74, 95% CI 0.44-1.22, p = 0.24). Mortality rates at 90 days were 17% in the 5-mg group, 24% in the 10-mg group and 18% in the placebo group. Treatment with trafermin was associated with an increased leukocytosis and a decrease in blood pressure: mean decrease in systolic blood pressure from baseline was 19 mm Hg in the 5-mg group, 22 mm Hg in the 10-mg group and 8 mm Hg in the placebo group. In a post hoc subgroup analysis, patients in the 5-mg group treated more than 5 h after the onset of symptoms showed an apparent advantage over placebo (OR 2.1, 95% CI 1.00-4.41, p = 0.044; after age adjustment: OR 1.9, 95% CI 0.91-4.13, p = 0.08).
CONCLUSIONS
With the proper treatment regimen, trafermin can likely be given safely to stroke patients. The 5-mg dose showed a trend toward a treatment advantage. The ideal time window for this agent may exceed 5 h. This may open new avenues for acute stroke therapy, aiming at enhancing recovery mechanisms rather than immediate neuroprotection.
Publication
Journal: Obesity (Silver Spring, Md.)
March/2/2014
Abstract
OBJECTIVE
<em>Fibroblast</em> <em>growth</em> <em>factor</em> (FGF)-<em>19</em> and FGF-21 are novel metabolic regulators that improve insulin resistance and obesity in rodents. The aim of the study was to assess the effects of laparoscopic sleeve gastrectomy (LSG) on serum concentrations of FGF-<em>19</em> and FGF-21 along with circulating bile acids and other relevant hormonal and biochemical parameters.
METHODS
Seventeen females with obesity undergoing LSG and 15 lean healthy females were included into the study. Anthropometric and biochemical parameters, serum concentrations of FGF-<em>19</em> and -21, insulin, adiponectin, leptin, C-reactive protein, resistin, amylin (total), ghrelin (active), glucagon-like peptide 1 (GLP-1, active), glucose-dependent insulinotropic peptide (GIP, total), peptide YY (PYY, total), pancreatic polypeptide (PP), and bile acids, and mRNA expression of selected adipokines and inflammatory markers in bioptic samples of subcutaneous fat were assessed at baseline and 6, 12, and 24 months after LSG.
RESULTS
LSG markedly decreased body weight, BMI, waist circumference, and insulin levels and improved systemic inflammation and lipid levels. FGF-<em>19</em> concentrations increased and FGF-21 concentrations decreased after LSG along with increased adiponectin and decreased leptin, amylin, and ghrelin levels. GLP-1, GIP, PP, and circulating bile acids were not affected by LSG. PYY decreased significantly 24 months after surgery only. mRNA expression analysis in subcutaneous fat showed markedly reduced proinflammatory state.
CONCLUSIONS
Our results indicate that increased FGF-<em>19</em> and decreased ghrelin concentrations could have partially contributed to the improvement of systemic inflammation and some metabolic parameters after LSG, while changes of FGF-21 are rather secondary because of weight loss.
Publication
Journal: Radiation Research
February/14/2002
Abstract
Numerous investigators have reported that direct exposure of cells to a low dose of ionizing radiation can induce a condition of enhanced radioresistance, i.e. a "radioadaptive" response. In this report, we investigated the hypothesis that a radioadaptive bystander effect may be induced in unirradiated cells by a transmissible <em>factor</em>(s) present in the supernatants of cells exposed to a low dose of alpha particles. Normal human lung <em>fibroblasts</em> (HFL-1) were irradiated with 1 cGy of alpha particles and their supernatants were transferred to unirradiated HFL-1 cells as a bystander cell model. Compared to directly irradiated cells that were not treated with supernatants from HFL-1 cells exposed to low-dose radiation, such treatment resulted in increased clonogenic survival after subsequent exposure to 10 and <em>19</em> cGy of alpha particles. Increases in protein levels of AP-endonuclease, a redox and DNA base excision repair protein, were found in the bystander cells, but not in directly irradiated cells. Supernatants from alpha-particle-irradiated cells were also found to increase the clonogenicity of unirradiated cells. These results, in conjunction with our earlier findings that supernatants from cells exposed to a low dose of alpha particles contain <em>growth</em>-promoting activity, suggest that this new bystander effect may be related to an increase in DNA repair and cell <em>growth</em>/cell cycle regulation.
Publication
Journal: Cancer Research
June/2/1991
Abstract
The study demonstrates that basic <em>fibroblast</em> <em>growth</em> <em>factor</em> (bFGF) serves as an inducer of radiation damage repair in bovine aortic endothelial cells (BAEC). Radiation dose-survival curves were generated with plateau-phase BAEC using culture dishes precoated with HR9-bFGF/extracellular matrix (ECM) for the postradiation colony formation assay. This natural basement membrane-like ECM is enriched with ECM-bound bFGF. Under these conditions the cells exhibited increased repair of radiation damage as compared to cells plated on top of the bFGF-free isotype of this extracellular matrix (the HR9/ECM). While the slopes of the curves did not differ significantly (Do 107 +/- 6.8 cGy on the HR9/ECM, compared to 112 +/- 1.3 cGy on the HR9-bFGF/ECM), there was a nearly complete elimination of the threshold shoulder in the curves generated on the bFGF-free HR9/ECM (Dq 29 +/- <em>19</em> cGy, compared to 174 +/- 22 cGy on the HR9-bFGF/ECM; P less than 0.05). Delayed plating experiments, in which the cells were irradiated under bFGF-free conditions (while adherent as contact-inhibited monolayers to the HR9/ECM in bFGF-free medium) and maintained after irradiation in the same culture for various periods of time, showed that the cells performed repair of potentially lethal damage (PLDR) and restored clonogenic ability, with a 24 h to immediate postradiation recovery ratio of 3.27. This expression of PLDR was inhibited by neutralizing monoclonal antibodies against bFGF, indicating that the irradiated cells secreted bFGF into their conditioned medium. Northern blot hybridization showed a 5.6-fold increase of the 3.7-kilobase species and a 4.7-fold increase of the 7.0-kilobase species of the bFGF-specific mRNA within 6 h after delivery of a single dose of 400 cGy. The data suggest that radiation induces a complete cycle of an autoregulated damage-repair pathway in BAEC, initiated by radiation-induced damage to cellular DNA and followed by stimulation of bFGF synthesis and its secretion into the medium. The newly synthesized bFGF stimulates the PLDR pathway, acting via an extracellular autocrine loop (inhibitable by specific anti-bFGF antibodies), leading to recovery of cells from radiation lesions and restoration of their clonogenic capacity.
Publication
Journal: American Journal of Pathology
February/17/1994
Abstract
Acidic <em>fibroblast</em> <em>growth</em> <em>factor</em> (aFGF) and basic <em>fibroblast</em> <em>growth</em> <em>factor</em> (bFGF) belong to a family of mitogenic polypeptides that are involved in cellular proliferation and differentiation. In this study we investigated the potential role of aFGF and bFGF in chronic pancreatitis (CP), a fibrotic condition associated with acinar cell dedifferentiation and atrophy, and <em>fibroblast</em>ic proliferation. By immunohistochemistry, aFGF and bFGF were abundant in pancreatic ductal and acinar cells in pancreatic tissues from CP patients. Immunoblotting with the same highly specific monoclonal antibodies demonstrated a marked increase in aFGF and bFGF in pancreatic homogenates from CP patients by comparison with the normal pancreas. Northern blot analysis indicated that, by comparison with normal controls, 16 of 21 CP tissues exhibited a 14-fold increase in aFGF mRNA levels, and <em>19</em> of 21 CP tissues exhibited a 15-fold increase in bFGF mRNA levels. In situ hybridization confirmed that this overexpression occurred in ductal and acinar cells, and indicated that both mRNA moieties colocalized with their respective proteins. These findings suggest that aFGF and bFGF may either be involved in the pathobiological mechanisms that occur in CP, or that their overexpression may be the consequence of other perturbations that occur in this disorder.
Publication
Journal: Cancer Research
May/2/1990
Abstract
Basic <em>fibroblast</em> <em>growth</em> <em>factor</em> (bFGF), a potent mitogen and angiogenic peptide, has been examined as an autocrine regulator of glioma cell <em>growth</em>. The addition of purified bovine pituitary bFGF to an established human glioma cell line, SNB-<em>19</em>, doubled the density of these cells in chemically defined medium. Half-maximal stimulation occurred at 8.2 ng/ml (480 pM). Also, human recombinant bFGF (hr-bFGF) significantly enhanced the <em>growth</em> of SNB-<em>19</em> cells in soft agar. SNB-<em>19</em> cells expressed both high and low affinity binding sites for hr-bFGF. These cells expressed approximately 13,000 high affinity sites/cell (Kd = 16.6 +/- 1.7 pM) and 9.5 x 10(6) low affinity sites/cell (Kd = 61.2 +/- 4.1 nM). The results of cross-linking experiments with iodinated hr-bFGF demonstrated the presence of two bands with molecular masses of 145 and 130 kDa. High affinity receptors were also demonstrated in SNB-<em>19</em> tumors grown in nude mice. SNB-<em>19</em> cell extracts contained mitogenic activity that eluted from heparin-agarose with high salt (1.2-2 M NaCl) and exhibited many properties normally associated with authentic bFGF. This material cross-reacted with a monoclonal antibody to hr-bFGF, comigrated with hr-bFGF by Western blot analysis, competed with 125I-hr-bFGF in a radioreceptor assay, and stimulated SNB-<em>19</em> cell <em>growth</em>. These results indicate that a human glioma cell line both expresses and utilizes a bFGF-like <em>growth</em> <em>factor</em>. Such a <em>factor</em> may be an important autocrine regulator of glioma cell <em>growth</em> and may also facilitate its neoplastic progression.
Publication
Journal: British Journal of Pharmacology
October/9/1996
Abstract
1. Airway smooth muscle proliferation is a significant component of the airway wall remodelling that occurs in asthma. In this study, the effects of glucocorticoids on mitogenic responses of human airway smooth muscle have been examined. 2. Pretreatment of smooth muscle cells with dexamethasone (100 nM, 60 min) inhibited thrombin-induced increases in [3H]-thymidine incorporation (DNA synthesis) and cell number. 3. Inhibition of thrombin-induced [3H]-thymidine incorporation was also observed with hydrocortisone (0.01-1 microM) and methylprednisolone (0.001-0.1 microM) pretreatment. In contrast, pretreatment with either testosterone (0.001-1 microM) progesterone (0.001-1 microM), 17 beta-oestradiol (0.001-1 microM), or aldosterone (0.001-1 microM) had no effect on the response to thrombin. 4. Responses to a range of mitogens including thrombin (0.01-. 10 u ml-1), epidermal <em>growth</em> <em>factor</em> (EGF, 3-3000 pM), basic <em>fibroblast</em> <em>growth</em> <em>factor</em> (bFGF, 0.3-300 pM) and foetal calf serum (FCS, 0.1-10% v/v) were inhibited by dexamethasone (100 nM) pretreatment. However, the magnitude of the inhibitory effect was dependent on the mitogen, with EGF being the least, and thrombin being the most sensitive to the inhibitory effect. 5. The potency of hydrocortisone as an inhibitor of [3H]-thymidine incorporation was reduced when FCS (10% v/v, which caused a 40 fold increase in [3H]-thymidine incorporation) was used as the mitogen in place of thrombin (0.3 u ml-1, which caused a 10 fold increase in [3H]-thymidine incorporation). 6. The effect of post-treatment with dexamethasone (100 nM) indicated that addition of the glucocorticoid up to 17-<em>19</em> h after thrombin (0.3 u ml-1) produced similar degrees of inhibition to those obtained when it was added as a pretreatment. Dexamethasone no longer produced an inhibitory effect if added 21 h or more after the addition of thrombin. 7. These results suggest that glucocorticoids regulate airway smooth muscle proliferation initiated by a range of stimuli. This effect may be of importance in the therapeutic actions of these compounds in asthma, particularly when they are used for prolonged periods of time.
Publication
Journal: Science Translational Medicine
October/14/2015
Abstract
Hepatic accumulation of bile acids is central to the pathogenesis of cholestatic liver diseases. Endocrine hormone <em>fibroblast</em> <em>growth</em> <em>factor</em> <em>19</em> (FGF<em>19</em>) may reduce hepatic bile acid levels through modulation of bile acid synthesis and prevent subsequent liver damage. However, FGF<em>19</em> has also been implicated in hepatocellular carcinogenesis, and consequently, the potential risk from prolonged exposure to supraphysiological levels of the hormone represents a major hurdle for developing an FGF<em>19</em>-based therapy. We describe a nontumorigenic FGF<em>19</em> variant, M70, which regulates bile acid metabolism and, through inhibition of bile acid synthesis and reduction of excess hepatic bile acid accumulation, protects mice from liver injury induced by either extrahepatic or intrahepatic cholestasis. Administration of M70 in healthy human volunteers potently reduces serum levels of 7α-hydroxy-4-cholesten-3-one, a surrogate marker for the hepatic activity of cholesterol 7α-hydroxylase (CYP7A1), the enzyme responsible for catalyzing the first and rate-limiting step in the classical bile acid synthetic pathway. This study provides direct evidence for the regulation of bile acid metabolism by FGF<em>19</em> pathway in humans. On the basis of these results, the development of nontumorigenic FGF<em>19</em> variants capable of modulating CYP7A1 expression represents an effective approach for the prevention and treatment of cholestatic liver diseases as well as potentially for other disorders associated with bile acid dysregulation.
Publication
Journal: American Journal of Kidney Diseases
January/16/2003
Abstract
BACKGROUND
Chronic uremia is considered a proinflammatory state associated with high cardiovascular morbidity and mortality. The aim of the present study is to evaluate the potential relationship between the prevalence of coronary artery calcification (CAC) and selected factors that may be involved in the process of atherogenesis (lipid profile, acute-phase reactants, growth factors, and cytokines).
METHODS
The study group consisted of 43 patients (19 women, 24 men) with a mean age of 50.6 +/- 13.4 years treated with peritoneal dialysis (PD) for a median period of 15 months (range, 2 to 96 months). Only patients with sinus rhythm were included. CAC score (CaSc) was measured using multirow spiral computed tomography (MSCT). As parameters of lipid profile, total cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, and triglycerides were assayed. C-reactive protein (CRP) and fibrinogen represented the level of acute-phase activation. Proinflammatory cytokines (interleukin-6 [IL-6] and tumor necrosis factor-alpha [TNF-alpha]), leptin, and basic fibroblast growth factor (bFGF) also were measured.
RESULTS
Median CaSc equaled 17.9 Agatston units (range, 0 to 5,502 Agatston units). No calcification was detected in 20 subjects (46.5%; CaSc < 10 Agatston units). CaSc correlated with age (R = 0.57; P < 0.0001), body mass index (R = 0.42; P < 0.005), and serum leptin (R = 0.3; P < 0.05) and CRP levels (R = 0.38; P < 0.05). The correlation with PD therapy duration was borderline statistically significant (P = 0.063). Patients with the greatest values for CaSc >> 400 Agatston units) were characterized by significantly greater levels of IL-6, bFGF, and CRP compared with subjects with a CaSc less than 10 Agatston units (P < 0.05 for all). Patients with history of coronary artery disease (CAD) had significantly greater CaSc values (median, 778.6 versus 3.3 Agatston units; P < 0.001) compared with those without CAD. Serum triglyceride levels were significantly greater and HDL cholesterol levels were significantly lower in patients with CAD. The first group also was characterized by significantly greater serum TNF-alpha (P < 0.01) and CRP levels (P < 0.005). In multiple regression analysis, only age was independently associated with CaSc (beta = 0.45; P = 0.002).
CONCLUSIONS
Our results may suggest an association between CAC and chronic inflammation activity in the mentioned group of patients. To our knowledge, this is the first study reporting the prevalence of CAC in PD patients using the MSCT method. The association between CaSc results and classic, as well as inflammatory, risk factors for CAD found in this study should be interpreted with caution because of its method limitations (cross-sectional design, heterogeneity of study population, and small number of studied patients).
Publication
Journal: Alimentary Pharmacology and Therapeutics
September/22/2011
Abstract
BACKGROUND
One half of patients with constipation are not satisfied with available therapies, hence there is a need for more effective and well-tolerated drugs.
OBJECTIVE
To evaluate the effects of a specific inhibitor of the Ileal Bile Acid Transporter (IBAT; syn apical sodium-dependent bile acid transporter; ASBT) in patients with chronic idiopathic constipation (CIC) with focus on safety, colonic transit and efficacy signals.
METHODS
This was a single-centre, prospective, randomised, double-blind, placebo-controlled study with a dose-escalating design in patients with CIC. In addition to evaluation of conventional safety and tolerability parameters, (i) colonic transit time (CTT) was measured using radio-opaque markers, (ii) metabolic parameters [lipid profile, C4 (7α-hydroxy-4-cholesten-3-one) and FGF<em>19</em> (<em>Fibroblast</em> <em>Growth</em> <em>Factor</em> <em>19</em>)] were evaluated, and (iii) constipation parameters, such as changes in stool frequency and consistency, were analysed.
RESULTS
Thirty patients were randomised into five dose-levels (range: 0.1-10 mg/day) or to placebo. All patients completed a 14-day treatment period, and the safety/tolerability analysis was favourable. A3309, present in picomolar concentrations in plasma, induced up to a three-fold increase in bile acid synthesis (C4) and a reduction of plasma FGF<em>19</em>, as well as reduction in total and LDL cholesterol. CTT was reduced in the highest dose groups; the main acceleration was identified in the left colon. Efficacy parameters showed trends for increased number of spontaneous bowel movements and improved stool consistency.
CONCLUSIONS
Ileal Bile Acid Transporter inhibition is a novel mechanism for treatment of patients with chronic idiopathic constipation and has additional benefits of improving metabolic parameters (EudraCT 2008-003255-72).
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