<em>Fibroblast</em> <em>growth</em> <em>factor</em> <em>21</em> is a novel hormonal regulator with the potential to treat a broad variety of metabolic abnormalities, such as type 2 diabetes, obesity, hepatic steatosis, and cardiovascular disease. Human recombinant wild type FGF<em>21</em> (FGF<em>21</em>) has been shown to ameliorate metabolic disorders in rodents and non-human primates. However, development of FGF<em>21</em> as a drug is challenging and requires re-engineering of its amino acid sequence to improve protein expression and formulation stability. Here we report the design and characterization of a novel FGF<em>21</em> variant, LY2405319. To enable the development of a potential drug product with a once-daily dosing profile, in a preserved, multi-use formulation, an additional disulfide bond was introduced in FGF<em>21</em> through Leu118Cys and Ala134Cys mutations. FGF<em>21</em> was further optimized by deleting the four N-terminal amino acids, His-Pro-Ile-Pro (HPIP), which was subject to proteolytic cleavage. In addition, to eliminate an O-linked glycosylation site in yeast a Ser167Ala mutation was introduced, thus allowing large-scale, homogenous protein production in Pichia pastoris. Altogether re-engineering of FGF<em>21</em> led to significant improvements in its biopharmaceutical properties. The impact of these changes was assessed in a panel of in vitro and in vivo assays, which confirmed that biological properties of LY2405319 were essentially identical to FGF<em>21</em>. Specifically, subcutaneous administration of LY2405319 in ob/ob and diet-induced obese (DIO) mice over 7-14 days resulted in a 25-50% lowering of plasma glucose coupled with a 10-30% reduction in body weight. Thus, LY2405319 exhibited all the biopharmaceutical and biological properties required for initiation of a clinical program designed to test the hypothesis that administration of exogenous FGF<em>21</em> would result in effects on disease-related metabolic parameters in humans.

<em>Fibroblast</em> <em>growth</em> <em>factor</em> <em>21</em> is a member of endocrine FGFs subfamily, along with FGF19 and FGF23. It is emerging as a novel regulator with beneficial effects on a variety of metabolic parameters, including glucose and lipid control. FGF<em>21</em> activity depends on membrane protein betaKlotho that physically complexes with various FGF receptors, thus conferring them the ability to bind FGF<em>21</em> and activate downstream signaling pathways. FGF<em>21</em>, like other FGFs, folds to a beta-trefoil-like core region, with disordered N- and C-termini. In order to investigate their role in the activity of FGF<em>21</em>, we have constructed a series of deletion mutants and tested them for their ability to (1) bind betaKlotho, analyzed by surface plasmon resonance spectroscopy (2) signal through MAPK phosphorylation and inhibit apoptosis in 3T3-L1/betaKlotho <em>fibroblasts</em> (3) stimulate GLUT1 mRNA upregulation and glucose uptake in 3T3-L1 adipocytes. Binding studies with betaKlotho revealed that the interaction with the co-receptor involves the C-terminus, as progressive removal of amino acids from the carboxy end decreased affinity for betaKlotho. By contrast, removal of up to 17 amino acids from the N-terminus had no effect on the interaction with betaKlotho. Terminal deletions had greater effect on function, as deletions of six amino acids from the amino-terminus and only four from the carboxy-terminus each significantly impacted activity (10-fold). Of the extreme terminal truncations, with no detectable activity, DeltaN17 acted as competitive antagonist while DeltaC20 did not. Our structure/function studies show that the C-terminus is important for betaKlotho interaction whereas the N-terminus likely interacts directly with FGF receptors.

The bleomycin-induced rodent lung fibrosis model is commonly used to study mechanisms of lung fibrosis and to test potential therapeutic interventions, despite the well recognized dissimilarities to human idiopathic pulmonary fibrosis (IPF). Therefore, in this study, we sought to identify genomic commonalities between the gene expression profiles from 100 IPF lungs and 108 control lungs that were obtained from the Lung Tissue Research Consortium, and rat lungs harvested at Days 3, 7, 14, <em>21</em>, 28, 42, and 56 after bleomycin instillation. Surprisingly, the highest gene expression similarity between bleomycin-treated rat and IPF lungs was observed at Day 7. At this point of maximal rat-human commonality, we identified a novel set of 12 disease-relevant translational gene markers (C6, CTHRC1, CTSE, FHL2, GAL, GREM1, LCN2, MMP7, NELL1, PCSK1, PLA2G2A, and SLC2A5) that was able to separate almost all patients with IPF from control subjects in our cohort and in two additional IPF/control cohorts (GSE10667 and GSE24206). Furthermore, in combination with diffusing capacity of carbon monoxide measurements, four members of the translational gene marker set contributed to stratify patients with IPF according to disease severity. Significantly, pirfenidone attenuated the expression change of one (CTHRC1) translational gene marker in the bleomycin-induced lung fibrosis model, in transforming <em>growth</em> <em>factor</em>-β1-treated primary human lung <em>fibroblasts</em> and transforming <em>growth</em> <em>factor</em>-β1-treated human epithelial A549 cells. Our results suggest that a strategy focused on rodent model-human disease commonalities may identify genes that could be used to predict the pharmacological impact of therapeutic interventions, and thus facilitate the development of novel treatments for this devastating lung disease.

Deletions and amplifications are frequent alterations of the short arm of chromosome 8 associated with various types of cancers, including breast cancers. This indicates the likely presence of tumor suppressor genes and oncogenes. In the present study, we have used the expressed sequence tag (EST) map of 8p11-<em>21</em> to assemble a set of available cDNAs representing genes from this region. DNA arrays were prepared for expression analysis and search for genes potentially involved in breast cancer. Underexpresion in tumoral breast cells (versus normal breast) was observed for 15 transcripts. Among these, the Frizzled-related gene FRP1/FRZB, was turned off in 78% of breast carcinomas, suggesting that the lack of its product may be associated with malignant transformation. Overexpression in tumoral breast cells was observed for 13 genes. The FGFR1 gene, that encodes a tyrosine kinase receptor for members of the <em>fibroblast</em> <em>growth</em> <em>factor</em> family, was identified as a good candidate for one amplification unit. Taken together, our results demonstrate that such a strategy can rapidly identify genes with an altered pattern of expression and provide candidate genes for malignancies.

OBJECTIVE

Angiogenesis is mediated by a number of different growth factors and appears vital for tumor growth. The understanding of angiogenic mechanisms could offer new therapeutic perspectives; in this context, the role of four potentially angiogenic growth factors was analyzed in a large series of meningiomas of different grades.

METHODS

Vascular endothelial growth factor (VEGF), placenta growth factor, hepatocyte growth factor/scatter factor, and basic fibroblast growth factor were quantified in 69 tumors by enzyme-linked immunosorbent assay. Microvessel density and proliferative activity were determined on paraffin sections, and clinical tumor invasiveness was rated. Induction of endothelial chemotaxis and capillary-like tube formation were studied in vitro using modified Boyden chamber assays and three-dimensional collagen gel assays, respectively.

RESULTS

Tumors included 40 benign (World Health Organization [WHO] Grade I), 21 atypical (WHO Grade II), and 8 anaplastic/malignant (WHO Grade III) meningiomas. We found a correlation between meningioma grade and VEGF content (r = 0.37, P = 0.002), which was 2-fold higher in atypical than in benign meningiomas (P = 0.022) and 10-fold higher in malignant than in benign meningiomas (P = 0.025). Among different subtypes of Grade I meningiomas, VEGF levels were 10-fold higher in meningothelial than in fibrous meningiomas (P = 0.015). None of the other three factors investigated showed any association with tumor grade, microvessel density, or invasiveness, and VEGF also did not correlate with vascularity or invasiveness. Moreover, vascularity did not increase with malignancy grade. Endothelial chemotaxis and capillary-like tube formation in vitro were induced by meningioma extracts and were most effectively blocked by co-addition of antibodies against basic fibroblast growth factor, followed by anti-VEGF, whereas anti-hepatocyte growth factor/scatter factor was not effective. The chemotactic activity of meningioma extracts on endothelial cells correlated with their VEGF content (r = 0.6, P = 0.003).

CONCLUSIONS

Meningiomas do not show an angiogenic switch involving VEGF and/or hepatocyte growth factor/scatter factor, as has previously been found in gliomas. Nevertheless, the biological activity of VEGF and basic fibroblast growth factor in meningiomas suggests that both are potential targets for antiangiogenic therapy in meningiomas of all WHO grades.

BACKGROUND

Autosomal dominant cerebellar ataxias are a clinical and genetically heterogeneous group of progressive neurodegenerative diseases, at present associated with 22 loci (spinocerebellar ataxia [SCA] 1-SCA8, SCA10-SCA19, SCA21, SCA22, fibroblast growth factor 14 [FGF14]-SCA, and dentatorubral-pallidoluysian atrophy [DRPLA]). The relevant gene has been identified in 12 cases (SCA1-3, SCA6-8, SCA10, SCA12, FGF14, and DRPLA), and in all but the recently identified SCA14, SCA17, PRKCG and FGF14 genes, the defect consists of the expansion of a short nucleotide repeat.

OBJECTIVE

To investigate the relative prevalence of SCA1-3, SCA6-8, SCA10, SCA12, and SCA17 gene expansions in Italian families with hereditary ataxia, specifically to verify the occurrence of SCA10, SCA12, and SCA17 in Italy; and to analyze samples from probands with negative test results at the initial screening by means of the repeat expansion detection technique to identify CAG/CTG expansions in novel loci.Patients Two hundred twenty-five unrelated Italian index cases with hereditary ataxia, most (n = 183) of whom presented with a clear dominantly transmitted trait.

RESULTS

We found that SCA1 and SCA2 gene mutations accounted for most cases (21% and 24%, respectively). We found SCA3, SCA6, SCA7, SCA8, and SCA17 to be very rare (approximately 1% each), and no case of SCA10 or SCA12 was identified. Half of the index cases (113/225) were negative for expansions in the known SCA genes. Repeat expansion detection analysis performed on 111 of these cases showed a CAG/CTG repeat expansion of at least 50 triplets in 22 (20%). Twenty-one of 22 expansions could be attributed to length variation at 2 polymorphic loci (expanded repeat domain CAG/CTG 1 [ERDA1] or CTG repeat on chromosome 18q21.1 [CTG18.1]). In 1 patient, the expansion was assigned to the DRPLA gene.

CONCLUSIONS

The distribution of SCA1-3 and SCA6-7 gene mutations is peculiar in Italy. We found a relatively high frequency of SCA1 and SCA2 gene expansions; SCA3, SCA6, and SCA7 mutations were rare, compared with other European countries. No SCA10 or SCA12 and only a few SCA8 (2/225) and SCA17 (2/225) families were detected. In patients negative for defects in known SCA genes, repeat expansion detection data strongly suggest that, at least in our population, CAG/CTG expansions in novel genes should be considered an unlikely cause of the SCA phenotype.

<em>Fibroblast</em> <em>growth</em> <em>factor</em> <em>21</em> (FGF<em>21</em>) stimulates fatty acid oxidation and ketone body production in animals. In this study, we investigated the role of FGF<em>21</em> in the metabolic activity of sodium butyrate, a dietary histone deacetylase (HDAC) inhibitor. FGF<em>21</em> expression was examined in serum and liver after injection of sodium butyrate into dietary obese C57BL/6J mice. The role of FGF<em>21</em> was determined using antibody neutralization or knockout mice. FGF<em>21</em> transcription was investigated in liver and HepG2 hepatocytes. Trichostatin A (TSA) was used in the control as an HDAC inhibitor. Butyrate was compared with bezafibrate and fenofibrate in the induction of FGF<em>21</em> expression. Butyrate induced FGF<em>21</em> in the serum, enhanced fatty acid oxidation in mice, and stimulated ketone body production in liver. The butyrate activity was significantly reduced by the FGF<em>21</em> antibody or gene knockout. Butyrate induced FGF<em>21</em> gene expression in liver and hepatocytes by inhibiting HDAC3, which suppresses peroxisome proliferator-activated receptor-α function. Butyrate enhanced bezafibrate activity in the induction of FGF<em>21</em>. TSA exhibited a similar set of activities to butyrate. FGF<em>21</em> mediates the butyrate activity to increase fatty acid use and ketogenesis. Butyrate induces FGF<em>21</em> transcription by inhibition of HDAC3.

BACKGROUND

Cartilage degeneration driven by catabolic stimuli is a critical pathophysiological process in osteoarthritis (OA). We have defined fibroblast growth factor 2 (FGF-2) as a degenerative mediator in adult human articular chondrocytes. Biological effects mediated by FGF-2 include inhibition of proteoglycan production, up-regulation of matrix metalloproteinase-13 (MMP-13), and stimulation of other catabolic factors. In this study, we identified the specific receptor responsible for the catabolic functions of FGF-2, and established a pathophysiological connection between the FGF-2 receptor and OA.

METHODS

Primary human articular chondrocytes were cultured in monolayer (24 hours) or alginate beads (21 days), and stimulated with FGF-2 or FGF18, in the presence or absence of FGFR1 (FGF receptor 1) inhibitor. Proteoglycan accumulation and chondrocyte proliferation were assessed by dimethylmethylene blue (DMMB) assay and DNA assay, respectively. Expression of FGFRs (FGFR1 to FGFR4) was assessed by flow cytometry, immunoblotting, and quantitative real-time PCR (qPCR). The distinctive roles of FGFR1 and FGFR3 after stimulation with FGF-2 were evaluated using either pharmacological inhibitors or FGFR small interfering RNA (siRNA). Luciferase reporter gene assays were used to quantify the effects of FGF-2 and FGFR1 inhibitor on MMP-13 promoter activity.

RESULTS

Chondrocyte proliferation was significantly enhanced in the presence of FGF-2 stimulation, which was inhibited by the pharmacological inhibitor of FGFR1. Proteoglycan accumulation was reduced by 50% in the presence of FGF-2, and this reduction was successfully rescued by FGFR1 inhibitor. FGFR1 inhibitors also fully reversed the up-regulation of MMP-13 expression and promoter activity stimulated by FGF-2. Blockade of FGFR1 signaling by either chemical inhibitors or siRNA targeting FGFR1 rather than FGFR3 abrogated the up-regulation of matrix metalloproteinases 13 (MMP-13) and a disintegrin and metalloproteinase with a thrombospondin type 1 motif 5 (ADAMTS5), as well as down-regulation of aggrecan after FGF-2 stimulation. Flow cytometry, qPCR and immunoblotting analyses suggested that FGFR1 and FGFR3 were the major FGFR isoforms expressed in human articular chondrocytes. FGFR1 was activated more potently than FGFR3 upon FGF-2 stimulation. In osteoarthritic chondrocytes, FGFR3 was significantly down regulated (P < 0.05) with a concomitant increase in the FGFR1 to FGFR3 expression ratio (P < 0.05), compared to normal chondrocytes. Our results also demonstrate that FGFR3 was negatively regulated by FGF-2 at the transcriptional level through the FGFR1-ERK (extracellular signal-regulated kinase) signaling pathway in human articular chondrocytes.

CONCLUSIONS

FGFR1 is the major mediator with the degenerative potential in the presence of FGF-2 in human adult articular chondrocytes. FGFR1 activation by FGF-2 promotes catabolism and impedes anabolism. Disruption of the balance between FGFR1 and FGFR3 signaling ratio may contribute to the pathophysiology of OA.

OBJECTIVE

<em>Fibroblast</em> <em>growth</em> <em>factor</em> <em>21</em> (FGF<em>21</em>), a hormone predominantly secreted by the liver, has been shown to be positively associated with the severity of non-alcoholic fatty liver disease (NAFLD) in cross-sectional studies. We investigated the prospective association of FGF<em>21</em> with NAFLD development in a 3-year prospective study involving a population-based cohort comprising 808 Chinese subjects.

METHODS

Serum FGF<em>21</em> levels at baseline and follow-up were measured using an enzyme-linked immunosorbent assay. Independent predictors of NAFLD development were identified using multiple logistic regressions. The predicting accuracy of the models was evaluated using area under the receiver-operating characteristic (ROC) curves (AUCs).

RESULTS

In subjects who had progressed to NAFLD, the baseline FGF<em>21</em> concentration (319.12 pg/ml [172.65, 518.78]) was significantly higher than that in subjects who did not develop NAFLD (199.10 pg/ml [123.56, 322.80]) (p <0.001). At follow-up, significant increase of FGF<em>21</em> level was observed in those subjects who developed NAFLD (p <0.05). Baseline FGF<em>21</em> was an independent predictor of NAFLD (OR: 7.102 [95% CI 2.488-20.270]; p <0.001), together with body mass index (BMI) (OR: 1.489 [95% CI 1.310-1.691]; p <0.001). The ROC-AUC was 0.816 (95% CI 0.766-0.867) for the FGF<em>21</em> Model, which was calculated with FGF<em>21</em> and BMI. FGF<em>21</em> Model <0.13 can be used to rule out (sensitivity=85.71%, negative likelihood ratio=0.23) and ≥0.30 can be rule in (specificity=86.34%, positive likelihood ratio=3.66) ultrasonography-diagnosed NAFLD after 3 years.

CONCLUSIONS

High serum FGF<em>21</em> concentration was an independent predictor of NAFLD in humans. The FGF<em>21</em> Model and its cut-offs may be useful for early diagnosis and intervention of NAFLD.

BACKGROUND

Biliary tract cancers (BTCs) typically present at an advanced stage, and systemic chemotherapy is often of limited benefit.

METHODS

Hybrid capture-based comprehensive genomic profiling (CGP) was performed for 412 intrahepatic cholangiocarcinomas (IHCCAs), 57 extrahepatic cholangiocarcinomas (EHCCAs), and 85 gallbladder carcinomas (GBCAs). The mutational profile was correlated with the clinical outcome of standard and experimental therapies for 3<em>21</em> patients. Clinical variables, detected mutations, and administered therapies were correlated with overall survival (OS) in a Cox regression model.

RESULTS

The most frequent genetic aberrations (GAs) observed were tumor protein 53 (TP53; 27%), cyclin-dependent kinase inhibitor 2A/B (CDKN2A/B; 27%), KRAS (22%), AT-rich interactive domain-containing protein 1A (ARID1A; 18%), and isocitrate dehydrogenase 1 (IDH1; 16%) in IHCCA; KRAS (42%), TP53 (40%), CDKN2A/B (17%), and SMAD4 (<em>21</em>%) in EHCCA; and TP53 (59%), CDKN2A/B (19%), ARID1A (13%), and ERBB2 (16%) in GBCA. <em>Fibroblast</em> <em>growth</em> <em>factor</em> receptor (FGFR; 11%) and IDH mutations (20%) were mostly limited to IHCCA but appeared to be mutually exclusive. In the IHCCA group, TP53 and KRAS mutations were associated significantly with poor OS, whereas FGFR2 mutations were associated with improved OS (P = .001), a younger age at onset, and female sex. IDH1/2 mutations were not prognostic. In a multivariate model, the effects of TP53 and FGFR GAs remained significant (P < .05). Patients with FGFR GAs had superior OS with FGFR-targeted therapy versus standard regimens (P = .006). Targeted therapy in IHCCA was associated with a numerical OS improvement (P = .07).

CONCLUSIONS

This is the largest clinically annotated data set of BTC cases with CGP and indicates the potential of CGP for improving outcomes. CGP should be strongly considered in the management of BTC patients. Cancer 2016;122:3838-3847. © 2016 American Cancer Society.

Intrahippocamal injections of kainic acid (KA) significantly increase the expression of monocyte chemoattractant protein-1 (MCP-1) and macrophage inflammatory protein-2 (MIP-2) in the ipsilateral hippocampus at 2-4 h and <em>21</em>-45 days post-administration, suggesting the possible involvement of these chemokines in both neurodegenerative and regenerative processes. To examine the possible role of these chemokines on neuronal cell death, hippocampal neurons were incubated with either MCP-1 or MIP-2 in vitro and examined to assess the effects on neuronal cell viability. These treatments resulted in significant neuronal apoptosis that could be abrogated by prior treatment with the caspase-1 inhibitor, Z-VAD-FMK, the caspase-3 inhibitor, Z-DEVD-FMK, the Galphai inhibitor, pertussis toxin, or the MAO-B inhibitor, (-)deprenyl. Furthermore, this chemokine apoptotic effect could also be observed in vivo as intrahippocampal injections of MCP-1 or MIP-2 resulted in the apoptosis of hippocampal neurons, thus supporting a direct role of these chemokines in neuronal death. In contrast, immunohistological analysis of kainic acid lesions on days <em>21</em>-45 revealed significant expression of MCP-1 and MIP-2 associated with reactive astrocytes and macrophages, respectively, with no apoptotic populations being observed. These results suggested that these chemokines might also mediate distinct biological effects on local microenvironmental cell populations at various stages post truama and during cellular repair. To address this possibility, astrocyte were cultured in the presence or absence of these chemokines and examined by microarray analysis for effects on astrocytes gene expression. A number of genes encoding proteins associated with inflammation, cellular signaling, differentiation, and repair were directly modulated by chemokine treatment. More specifically, the RNA and protein expression of the neurotrophic <em>factor</em>, basic <em>fibroblast</em> <em>growth</em> <em>factor</em> (bFGF), was found to be significantly increased upon culture with MCP-1 and MIP-2. Conditioned media derived from chemokine-stimulated astrocytes also facilitated bFGF-dependent neuronal cell differentiation and promoted survival of H19-7 neurons in vitro, suggesting a possible role for chemokine-activated astrocytes as a source of trophic support. Taken together, these data support possible autocrine and paracrine roles for MCP-1 and MIP-2 in both the "death and life" of hippocampal neurons following CNS injury.

The postnatal development of Leydig cells can be divided into three distinct stages: initially they exist as <em>fibroblast</em>-like progenitor Leydig cells (PLCs) appearing in the testis by Days 14-<em>21</em>; subsequently, by Day 35, they become immature Leydig cells (ILCs) acquiring steroidogenic organelle structure and enzyme activities but metabolizing most of the testosterone they produce; finally, as adult Leydig cells (ALCs) by Day 90, they actively produce testosterone. The <em>factors</em> controlling proliferation and differentiation of Leydig cells remain largely unknown, and the aim of the present study was to identify changes in gene expression during development through cDNA array analysis of PLCs, ILCs, and ALCs. By cluster analysis, it was determined that the transitions from PLC to ILC to ALC were associated with downregulation of mRNAs corresponding to 107 genes. The downregulated genes included cell-cycle regulators, e.g., cyclin D1 (Ccnd1); <em>growth</em> <em>factors</em>, e.g., basic <em>fibroblast</em> <em>growth</em> <em>factor</em> (Fgf2); <em>growth</em>-<em>factor</em>-related receptors, e.g., platelet-derived <em>growth</em> <em>factor</em> alpha receptor (Pdgfra); oncogenes, e.g., kit oncogene (Kit); and transcription <em>factors</em>, e.g., early <em>growth</em> response 1 (Egr1). Conversely, expression levels of 264 genes were increased by at least twofold. Most of these were related to differentiated function and included steroidogenic enzymes, e.g., 11beta-hydroxysteroid dehydrogenase 2 (Hsd11b2); neurotransmitter receptors, e.g., acetylcholine receptor nicotinic alpha 4 (Chrna4); stress response <em>factors</em>, e.g., glutathione transferase 8 (Gsta4); and protein turnover enzymes, e.g., tissue inhibitor of metalloproteinase 2 (Timp2). The detection of Hsd11b2 mRNA in the array was the first indication that this gene is expressed in Leydig cells, and parallel increases in Hsd11b2 mRNA and enzyme activity were recorded. Thus, gene profiling demonstrates that postnatal development is associated with changes in the expression levels of several different clusters of genes consistent with the processes of Leydig cell <em>growth</em> and differentiation.

Heparin-binding (HB) epidermal <em>growth</em> <em>factor</em> (EGF)-like <em>growth</em> <em>factor</em> (HB-EGF), a member of the EGF protein family, is a potent mitogen for <em>fibroblasts</em>, smooth muscle cells, and keratinocytes that was initially identified as a secreted product of macrophage-like cells. HB-EGF and EGF appear to act on target cells utilizing the same receptor, but HB-EGF is distinguishable from EGF by its strong affinity for heparin. To facilitate studies of structure-function relationships in HB-EGF, a bacterial recombinant expression system was established that produced biologically active HB-EGF with the expected disulfide bonding pattern. Mutagenesis and protease digestion studies of the recombinant HB-EGF, coupled with heparin-binding analyses of synthetic peptides, indicated that the sequences within HB-EGF mediating its interaction with heparin are located primarily in a stretch of <em>21</em> amino acids characterized by a high content of lysine and arginine residues. Most of this heparin-binding domain lies in an amino-terminal region of HB-EGF that has no counterpart in EGF, but a portion of the <em>21</em>-residue sequence extends into the EGF-like region of HB-EGF. In addition, the mutagenesis and synthetic peptide studies indicated that sequences in HB-EGF lying outside of the <em>21</em>-residue stretch can also influence the interaction with heparin. Finally, a synthetic peptide derived from the <em>21</em>-residue stretch was found to compete with HB-EGF for binding to Chinese hamster ovary cells, suggesting that the heparin-binding sequences in HB-EGF may also mediate the interaction of this <em>factor</em> with cell surface heparan sulfate proteoglycan.

We have previously shown the development in vitro of tryptase+ human mast cells from fetal liver cells cocultured with murine 3T3 <em>fibroblasts</em>. In this study, recombinant human stem cell <em>factor</em> (rhuSCF), the ligand for the c-kit proto-oncogene product called Kit, stimulated the <em>growth</em> and differentiation primarily of mast cells from dispersed fetal liver cells, whereas recombinant human interleukin-3 (rhuIL-3) stimulated the differentiation of basophils along with other cell types. Cultures of fetal liver cells were initiated and maintained in the presence of rhuSCF or rhuIL-3 for up to 6 weeks. Metachromatic cells in cytospins were identified as mast cells primarily on the basis of tryptase expression, and as MCT or MCTC by immunohistochemistry using monoclonal antibodies against tryptase and chymase, whereas basophils were metachromatic, polymorphonuclear, and lacked these proteases. Levels of tryptase and histamine were measured by radioimmunoassay, tryptase and chymase activities by peptide hydrolysis, and cell surface Kit by flow cytometry with the monoclonal antibody YB5.B8. The predominant presence of mast cells occurred only in the cultures supplemented with rhuSCF. The percentage and total number of mast cells increased over time with increasing concentrations of rhuSCF and reached a plateau at 55 ng/mL. At this concentration of rhuSCF, mast cells first appeared by day 7; by day 42, 106% of the starting number of cells were present and 85% of these were tryptase+, 31% being weakly chymase+. These mast cells appeared immature by ultrastructural criteria; most cells were mononuclear, but some had nuclei with deeply divided lobes. DNA synthesis in tryptase+ mast cells at days <em>21</em> and 28 of culture with rhuSCF was demonstrated by incorporation of bromodeoxyuridine. Calculated levels of histamine (1.2 pg/mast cell) and tryptase (0.9 pg/mast cell) were similar to those determined previously in coculture experiments with murine 3T3 <em>fibroblasts</em>. Chymase activity was undetectable in most cell extracts. On day 0, 4% to 20% of fetal liver cells expressed cell surface Kit. In the presence of rhuSCF, the percentages and total numbers of Kit+ cells and the apparent concentration of Kit per cell increased along with the number of tryptase+ cells. In the presence of rhuIL-3, toluidine blue+, tryptase- cells first and maximally appeared at day 14 (11% +/- 2.5%). The percentage of these toluidine blue+ cells then declined to about 6% by days <em>21</em> and 35, while the total number of positive cells declined over 10-fold. Kit+ cells in the presence of rhuIL-3 declined from 9% on day 3 to 2% on day 35.(ABSTRACT TRUNCATED AT 400 WORDS)

When faced with a harsh climate or inadequate food, some mammals enter a state of suspended animation known as torpor. A major goal of torpor research is to determine mechanisms that integrate environmental cues, gene expression and metabolism to produce periods of torpor lasting from hours to weeks. Recent discoveries spanning the Metazoa suggest that sirtuins, the mammalian circadian clock, <em>fibroblast</em> <em>growth</em> <em>factor</em> <em>21</em> (FGF<em>21</em>) and lipids are involved in torpor induction. For example, sirtuins link cellular energy status to the mammalian circadian clock, oxidative stress and metabolic fuel selection. In this review, we discuss how these recent discoveries form a new hypothesis linking changes in the physical environment with changes in the expression of genes that regulate torpor induction.

The aim of this study was to produce dopaminergic neurons in vitro from human embryonic stem (hES) cells following treatment of various neurotrophic <em>factors</em>. MB03 hES cells were induced by retinoic acid (RA) or basic <em>fibroblast</em> <em>growth</em> <em>factor</em> (bFGF), which were further treated with brain derived neurotrophic <em>factor</em> (BDNF) or transforming <em>growth</em> <em>factor</em> (TGF)-alpha in each induction method during neuron differentiation days. At the final differentiation stage (<em>21</em> days), all treatment groups revealed very similar levels (bFGF, 76-78%; RA, 70-74%) of mature neurons (anti-NF-200) in two induction methods irrespective of the addition of BDNF or TGF-alpha. In addition, immunostaining and HPLC analyses revealed higher levels of tyrosine hydroxylase (20+/-2.3%) and dopamine (265.5+/-62.8 pg/ml) in the bFGF- and TGF-alpha-treated hES cells than in RA- or BDNF-treated hES cells. These data are one of the first reports on the generation of dopaminergic neurons of hES cells in vitro. Also, our results indicate that TGF-alpha may be successfully used in the bFGF induction protocol and yield higher numbers of dopaminergic neurons from hES cells.

The mineralocorticoids aldosterone and deoxycorticosterone acetate (DOCA) stimulate renal tubular salt reabsorption, increase salt appetite, induce extracellular volume expansion, and elevate blood pressure. Cardiac effects of mineralocorticoids include stimulation of matrix protein deposition leading to cardiac fibrosis, which is at least partially due to the direct action of the hormones on cardiac cells. The signaling mechanisms mediating mineralocorticoid-induced cardiac fibrosis have so far remained elusive. Mineralocorticoids have been shown to upregulate the serum- and glucocorticoid-inducible kinase 1 (SGK1), which participates in the effects of mineralocorticoids on renal tubular Na+ reabsorption and salt appetite. To explore the involvement of SGK1 in the pathogenesis of mineralocorticoid-induced cardiac fibrosis, SGK1 knockout mice (sgk1-/-) and wild-type littermates (sgk1+/+) were implanted a <em>21</em>-day-release 50-mg DOCA pellet and supplied with 1% NaCl in drinking water for 18 days. This DOCA/high-salt treatment increased blood pressure in both genotypes but led to significant cardiac fibrosis only in sgk1+/+ but not in sgk1-/- mice. According to real-time polymerase chain reaction and Western blotting, DOCA/high-salt treatment enhanced transcript levels and protein expression of cardiac connective tissue <em>growth</em> <em>factor</em> (CTGF) only in sgk1+/+ but not in sgk1-/- mice. Furthermore, DOCA (10 microM) upregulated CTGF expression and enhanced CTGF promoter activity in lung <em>fibroblasts</em> isolated from sgk1+/+ but not from sgk1-/- mice, an effect involving spironolactone-sensitive mineralocorticoid receptors and activation of nuclear <em>factor</em>-kappaB (NFkappaB). Our results suggest that SGK1 plays a decisive role in mineralocorticoid-induced CTGF expression and cardiac fibrosis.

The acute phase response (APR) produces marked alterations in lipid and carbohydrate metabolism including decreasing plasma ketone levels. <em>Fibroblast</em> <em>growth</em> <em>factor</em> <em>21</em> (FGF<em>21</em>) is a recently discovered hormone that regulates lipid and glucose metabolism and stimulates ketogenesis. Here we demonstrate that lipopolysaccharide (LPS), zymosan, and turpentine, which induce the APR, increase serum FGF<em>21</em> levels 2-fold. Although LPS, zymosan, and turpentine decrease the hepatic expression of FGF<em>21</em>, they increase FGF<em>21</em> expression in adipose tissue and muscle, suggesting that extrahepatic tissues account for the increase in serum FGF<em>21</em>. After LPS administration, the characteristic decrease in plasma ketone levels is accentuated in FGF<em>21</em>-/- mice, but this is not due to differences in expression of carnitine palmitoyltransferase 1α or hydroxymethyglutaryl-CoA synthase 2 in liver, because LPS induces similar decreases in the expression of these genes in FGF<em>21</em>-/- and control mice. However, in FGF<em>21</em>-/- mice, the ability of LPS to increase plasma free fatty acid levels is blunted. This failure to increase plasma free fatty acid could contribute to the accentuated decrease in plasma ketone levels because the transport of fatty acids from adipose tissue to liver provides the substrate for ketogenesis. Treatment with exogenous FGF<em>21</em> reduced the number of animals that die and the rapidity of death after LPS administration in leptin-deficient ob/ob mice and to a lesser extent in control mice. FGF<em>21</em> also protected from the toxic effects of cecal ligation and puncture-induced sepsis. Thus, FGF<em>21</em> is a positive APR protein that protects animals from the toxic effects of LPS and sepsis.

OBJECTIVE

The safety of bisphosphonates in human pregnancy has not been well established. To characterize pregnancy outcome in women receiving bisphosphonates, we conducted a multi-centre, prospective cohort study with a comparison group.

METHODS

Patients were recruited through 3 teratogen information centres in Canada and South Korea. We followed <em>21</em> women exposed to bisphosphonates during or <3 months before pregnancy, and <em>21</em> matched-comparison group women without exposure to known teratogens. Pregnancy/neonatal outcome data were collected by interview. The primary endpoint was neonatal outcome including major birth defects. The secondary endpoints included other pregnancy outcomes such as spontaneous abortions.

RESULTS

Indication of the therapy was osteoporosis in all patients. There was no difference in the maternal demographics between the 2 groups. In the bisphosphonate group, there were 18 live births, 2 spontaneous abortions and 1 therapeutic abortion, which were not significantly different from the comparison group. The mean gestational age (mean+/-SD) of the bisphosphonate group was 38.7+/-1.9 weeks (comparison group: 39.3+/-1.9 weeks; P=0.42), and the mean birth weight was 3.1+/-0.3 kg (comparison group: 3.3+/-0.5 kg; P=0.11). In the bisphosphonate group, there was a child diagnosed with Apert syndrome, an autosomal dominant acrocephalosyndactyly, with a fibroblast growth factor 2 mutation.

CONCLUSIONS

Coupled with existing data in the literature, our findings suggest that preconceptional and first-trimester use of bisphosphonates may not pose substantial fetal risks.

OBJECTIVE

Patients with eosinophilic esophagitis (EoE) often become dysphagic from the combination of organ fibrosis and motor abnormalities. We investigated mechanisms of dysphagia, assessing the response of human esophageal fibroblasts (HEFs), human esophageal muscle cells (HEMCs), and esophageal muscle strips to eosinophil-derived products.

METHODS

Biopsy specimens were collected via endoscopy from the upper, middle, and lower thirds of the esophagus of 18 patients with EoE and 21 individuals undergoing endoscopy for other reasons (controls). Primary cultures of esophageal fibroblasts and muscle cells were derived from 12 freshly resected human esophagectomy specimens. Eosinophil distribution was investigated by histologic analyses of full-thickness esophageal tissue. Active secretion of EoE-related mediators was assessed from medium underlying mucosal biopsy cultures. We quantified production of fibronectin and collagen I by HEF and HEMC in response to eosinophil products. We also measured the expression of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 by, and adhesion of human eosinophils to, HEFs and HEMCs. Eosinophil products were tested in an esophageal muscle contraction assay.

RESULTS

Activated eosinophils were present in all esophageal layers. Significantly higher concentrations of eosinophil-related mediators were secreted spontaneously in mucosal biopsy specimens from patients with EoE than controls. Exposure of HEFs and HEMCs to increasing concentrations of eosinophil products or co-culture with eosinophils caused HEFs and HEMCs to increase secretion of fibronectin and collagen I; this was inhibited by blocking transforming growth factor β1 and p38 mitogen-activated protein kinase signaling. Eosinophil binding to HEFs and HEMCs increased after incubation of mesenchymal cells with eosinophil-derived products, and decreased after blockade of transforming growth factor β1 and p38 mitogen-activated protein kinase blockade. Eosinophil products reduced electrical field-induced contraction of esophageal muscle strips, but not acetylcholine-induced contraction.

CONCLUSIONS

In an analysis of tissues samples from patients with EoE, we linked the presence and activation state of eosinophils in EoE with altered fibrogenesis and motility of esophageal fibroblasts and muscle cells. This process might contribute to the development of dysphagia.

<em>Fibroblast</em> <em>growth</em> <em>factor</em> <em>21</em> (FGF<em>21</em>) is the first known endocrine signal activated by protein restriction. Although FGF<em>21</em> is robustly elevated in low-protein environments, increased FGF<em>21</em> is also seen in various other contexts such as fasting, overfeeding, ketogenic diets, and high-carbohydrate diets, leaving its nutritional context and physiological role unresolved and controversial. Here, we use the Geometric Framework, a nutritional modeling platform, to help reconcile these apparently conflicting findings in mice confined to one of 25 diets that varied in protein, carbohydrate, and fat content. We show that FGF<em>21</em> was elevated under low protein intakes and maximally when low protein was coupled with high carbohydrate intakes. Our results explain how elevation of FGF<em>21</em> occurs both under starvation and hyperphagia, and show that the metabolic outcomes associated with elevated FGF<em>21</em> depend on the nutritional context, differing according to whether the animal is in a state of under- or overfeeding.

Fibrillin-1 localization in the myocardium and the modulation of its expression in cardiac fibrosis were examined. In normal rat hearts, fibrillin-1 was abundant throughout the myocardium as thin fibers that crossed over the perimysium and around arteries. After cardiac fibrosis was induced in rats by either 14-day ANG II infusion or <em>21</em>-day DOCA-salt treatment [a high endothelin-1 (ET-1) model], fibrillin-1 immunostaining was stronger in the interstitium (2.8-fold and 4.4-fold increases, respectively, in each model), extended between myocytes, and accumulated in microscopic scars and in the perivascular area of both ventricles. mRNA analysis confirmed its enhanced ventricular expression in both groups of rats (2.5-fold and 6.6-fold increments, respectively, in each model). In 1B normotensive and 2C hypertensive transgenic mice, two lines expressing an ANG II fusion protein in cardiac myocytes, strong fibrillin-1 immunoreactivity was observed in the interstitium and around arteries (3.7-fold and 7-fold increases, respectively). ANG II and transforming <em>growth</em> <em>factor</em>-beta1 enhanced fibrillin-1 synthesis by cardiac <em>fibroblasts</em>. Some fibrillin-1 fragments interacted with RGD-dependent integrins, including alpha(8)beta(1)-integrin, of cardiac <em>fibroblasts</em> but not necessarily through the RGD motif. Our findings illustrate that fibrillin-1 is an important constituent of the myocardium. In vitro and in vivo evidence suggests that ANG II can directly induce fibrillin-1 expression in cardiac <em>fibroblasts</em>. This protein can thus contribute to reactive and reparative processes.

The inappropriate regeneration of sequentially injured epithelium is an important process leading to pulmonary fibrosis. Previous studies have shown that the epithelial expression of epidermal <em>growth</em> <em>factor</em> receptor (EGFR) is increased in fibrotic lung tissue, compared with normal lung tissue, suggesting that EGFR-mediated signaling is involved in epithelial regeneration in fibrotic lung diseases. We examined the effect of EGFR inhibition using ZD1839, a selective EGFR tyrosine kinase inhibitor (TKI), on bleomycin-induced pulmonary fibrosis in mice. ICR mice were administered a single intratracheal injection of bleomycin (5 units/kg) on day 1. ZD1839 (200 mg/kg) or vehicle alone were administered p.o. 1 h before this injection and on days 1-5 each week for 3 weeks. Lung tissue was harvested on day <em>21</em>. Lung histology and collagen analysis performed on day <em>21</em> showed more severe fibrosis in the mice receiving both bleomycin and the EGFR-TKI than in the mice receiving bleomycin and the vehicle. An immunohistochemistry analysis showed that phosphorylated EGFR and proliferation cell nuclear antigen were highly expressed by the regenerated epithelial cells in the mice treated with bleomycin and the vehicle. In contrast, the expression of these antigens was attenuated in the mice treated with bleomycin and the EGFR-TKI. In vitro studies also demonstrated that the addition of ZD1839 at a concentration of < or =1 microM suppressed the proliferation of type II-like epithelial cells (A549) but not that of lung <em>fibroblasts</em> (IMR90). These results suggest that the inhibition of EGFR phosphorylation augments bleomycin-induced pulmonary fibrosis by reducing regenerative epithelial proliferation. Our data suggest that EGFR-TKIs should be used with caution in cancer patients with pulmonary fibrosis.

Thyroid hormone has profound and diverse effects on liver metabolism. Here we show that tri-iodothyronine (T3) treatment in mice acutely and specifically induces hepatic expression of the metabolic regulator <em>fibroblast</em> <em>growth</em> <em>factor</em> <em>21</em> (FGF<em>21</em>). Mice treated with T3 showed a dose-dependent increase in hepatic FGF<em>21</em> expression with significant induction at doses as low as 100 microg/kg. Time course studies determined that induction is seen as early as 4 h after treatment with a further increase in expression at 6 h after injection. As FGF<em>21</em> expression is downstream of the nuclear receptor peroxisome proliferator-activated receptor alpha (PPARalpha), we treated PPARalpha knock-out mice with T3 and found no increase in expression, indicating that hepatic regulation of FGF<em>21</em> by T3 in liver is via a PPARalpha-dependent mechanism. In contrast, in white adipose tissue, FGF<em>21</em> expression was suppressed by T3 treatment, with other T3 targets unaffected. In cell culture studies with an FGF<em>21</em> reporter construct, we determined that three transcription <em>factors</em> are required for induction of FGF<em>21</em> expression: thyroid hormone receptor beta (TRbeta), retinoid X receptor (RXR), and PPARalpha. These findings indicate a novel regulatory pathway whereby T3 positively regulates hepatic FGF<em>21</em> expression, presenting a novel therapeutic target for diseases such as non-alcoholic fatty liver disease.