Nerve <em>growth</em> <em>factor</em> (NGF) and acidic or basic <em>fibroblast</em> <em>growth</em> <em>factor</em> (aFGF and bFGF, respectively) induce neurite out<em>growth</em> from the rat pheochromocytoma cell line, PC12. The neurites induced by these three <em>factors</em> are stable for up to a month in cell culture in the continued presence of any of the above <em>growth</em> <em>factors</em>. bFGF (ED50 = 30 pg/ml) is 800 fold more potent in stimulating neurite out<em>growth</em> than aFGF (ED50 = 25 ng/ml) and 260 fold more potent than NGF (ED50 = 8 ng/ml). While the neurotropic activities of aFGF and NGF are potentiated by heparin, that of bFGF is both partially inhibited or stimulated, depending upon the concentration of bFGF. Radioreceptor binding experiments show that aFGF and bFGF bind to a common binding site on the PC12 cell surface. Affinity labeling studies demonstrate a single receptor with an apparent molecular weight of 145,000 daltons, which corresponds to the high molecular weight receptor identified in BHK-<em>21</em> cells. NGF does not appear to compete with aFGF or bFGF for binding to the receptor. Heparin blocked the binding of bFGF to the receptor but had only a small inhibitory effect on the binding of aFGF to the receptor. Thus, it appears that heparin inhibition of the neurotropic effects of bFGF occurs, at least in part, by impairing the interaction of bFGF with the receptor, while having little effect on that of aFGF. The stimulatory effects of heparin on the neurotropic activity of aFGF, bFGF, and NGF may occur through a site not associated with the respective cellular receptor for the <em>growth</em> <em>factors</em>.

Single point mutations of the amyloid precursor protein generate Abeta variants bearing amino acid substitutions at positions <em>21</em>-23. These mutants are associated with distinct hereditary phenotypes of cerebral amyloid angiopathy, manifesting varying degrees of tropism for brain vessels, and impaired microvessel remodeling and angiogenesis. We examined the differential effects of E22Q (Dutch), and E22G (Arctic) variants in comparison to WT Abeta on brain endothelial cell proliferation, angiogenic phenotype expression triggered by <em>fibroblast</em> <em>growth</em> <em>factor</em> (FGF-2), pseudo-capillary sprouting, and induction of apoptosis. E22Q exhibited a potent anti-angiogenic profile in contrast to E22G, which had a much weaker effect. Investigations on the FGF-2 signaling pathway revealed the greatest differences among the peptides: E22Q and WT peptides suppressed FGF-2 expression while E22G had barely any effect. Phosphorylation of the FGF-2 receptor, FGFR-1, and the survival signal Akt were abolished by E22Q and WT peptides, but not by E22G. The biological dissimilar effect of the mutant and WT peptides on cerebral EC cannot be assigned to a particular Abeta structure, suggesting that the toxic effect of the Abeta assemblies goes beyond mere multimerization.

We present a fast protocol that can be used to obtain highly purified cultures of proliferating adult human and rat Schwann cells accessible for non-viral transfection methods. The use of enriched genetically modified adult Schwann cells is of interest in the context of autologous cell transplantation within nerve transplants for peripheral nerve repair. Cell preparation from pre-degenerated adult peripheral nerves is described, together with the use of melanocyte <em>growth</em> medium plus forskolin, <em>fibroblast</em> <em>growth</em> <em>factor</em>-2 (FGF-2), pituitary extract and heregulin as a selective, serum-free culture medium and a subsequent cell enrichment step (cold jet). Proliferating adult Schwann cells can be efficiently genetically modified using optimized, non-viral electroporation protocols. The protocol results in Schwann cell cultures that are more than 90-95% pure, and transfection efficiencies vary depending on the initial cell constitution from 20 to 40%. The procedure takes up to <em>21</em> d, depending on the length of the pre-degeneration period.

<em>Fibroblast</em> <em>growth</em> <em>factor</em> (FGF) <em>21</em> is an endocrine <em>factor</em> that normalizes glucose homeostasis and reduces insulin resistance in diabetes. Although the pancreas is an FGF<em>21</em> target organ, its role in pancreatic islets remains obscure. This study aimed to elucidate the physiological role of FGF<em>21</em> in pancreatic islets using FGF<em>21</em>-knockout (FGF<em>21</em>-KO) mice. Twenty-four-week-old male global FGF<em>21</em>-KO mice were used in this study. Glucose and insulin tolerance were assessed. Expression of genes and proteins related to islet function and underlying mechanisms were also examined. Islet morphology and insulin-secreting capacity were further evaluated. FGF<em>21</em>-KO mice exhibited insulin resistance while being normoglycemic, associated with increases in beta-cell proliferation and insulin synthesis, acting as compensatory responses. This phenotype probably results from enhanced <em>growth</em> hormone (GH) sensitivity in FGF<em>21</em>-KO mouse islets. In addition, ex vivo FGF<em>21</em> treatment in normal C57BL/6J mouse islets reduced GH signaling, probably via upregulation of peroxisome proliferator-activated receptor gamma (PPARγ) and cytokine-inducible SH-2 containing (CIS) protein, whereas KO mouse islets displayed reduced PPARγ and CIS expression. FGF<em>21</em> treatment also reversed GH-induced insulin expression, beta-cell proliferation and GH-impaired glucose-stimulated insulin secretion (GSIS) in islets. Furthermore, distorted islet morphology and impaired GSIS were observed in KO mice, suggestive of islet dysfunction, whereas the enhanced insulin expression and impaired GSIS in FGF<em>21</em>-KO mouse islets could be reversed by blockade of GH signaling. Our data indicate that FGF<em>21</em> is important in the regulation of beta-cell proliferation and insulin synthesis, probably via modulation of GH signaling. These findings provide evidence that FGF<em>21</em> is an obligatory metabolic regulator in pancreatic islets and shed new light onto the role of endogenous FGF<em>21</em> in the pathogenesis of insulin resistance and islet dysfunction.

FGF21 is a novel member of the FGFs family, is mainly expressed in liver and it functions as a potent activator of glucose uptake on adipocytes. When over expressed in transgenic mice, it protects animals from diet-induced obesity and its administration to diabetic rodents and monkeys lowers blood glucose and triglyceride levels. Recently, increased levels of FGF21 have been identified as an independent risk factor related with metabolic syndrome. A review of the relevant roles of FGF21 in metabolism is presented here.

OBJECTIVE

Receptor tyrosine kinase (RTK) activation is critical for growth factor-mediated cell proliferation. The present study was designed to determine the effect of tyrphostin AG1295, a selective blocker of platelet-derived growth factor (PDGF) RTK, on proliferative vitreoretinopathy (PVR) development.

METHODS

Rabbit conjunctival fibroblasts cells (1 x 10(4)) were seeded into 96-well plates and maintained in Dulbecco's modified essentialmedium (DMEM) with 0.5% fetal bovine serum. The cells were exposed to 50 ng/mL PDGF-AAor PDGF-BBor phosphate-buffered saline with or without AG1295 (1 microM, 10 microM, and 100 microM). After 3 days, the viable cells in each well were measured by 3,(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. Homologous rabbit conjunctival fibroblasts were injected intravitreally, followed by injection of 100 microM of AG1295. The development of tractional retinal detachment (TRD) was assessed to evaluate the effect of AG1295 in vivo. Electroretinography and histologic studies were performed after intravitreal injection of AG1295 into untreated eyes to evaluate toxicity.

RESULTS

Two concentrations of AG1295 (10 and 100 microM) significantly inhibited rabbit conjunctival fibroblast cell growth stimulated by PDGF-AA or PDGF-BB in vitro. Development of TRD was significantly attenuated (P <.01) with 100 microM of AG1295 until day 21. No significant histologic or retinal functional damage was found in the AG1295-treated group.

CONCLUSIONS

PDGF receptor specific inhibitor AG1295 attenuated PVR without significant side effects in rabbits. This reagent could be a useful treatment to prevent PVR.

Age-related thymic degeneration is associated with loss of naïve T cells, restriction of peripheral T-cell diversity, and reduced healthspan due to lower immune competence. The mechanistic basis of age-related thymic demise is unclear, but prior evidence suggests that caloric restriction (CR) can slow thymic aging by maintaining thymic epithelial cell integrity and reducing the generation of intrathymic lipid. Here we show that the prolongevity ketogenic hormone <em>fibroblast</em> <em>growth</em> <em>factor</em> <em>21</em> (FGF<em>21</em>), a member of the endocrine FGF subfamily, is expressed in thymic stromal cells along with FGF receptors and its obligate coreceptor, βKlotho. We found that FGF<em>21</em> expression in thymus declines with age and is induced by CR. Genetic gain of FGF<em>21</em> function in mice protects against age-related thymic involution with an increase in earliest thymocyte progenitors and cortical thymic epithelial cells. Importantly, FGF<em>21</em> overexpression reduced intrathymic lipid, increased perithymic brown adipose tissue, and elevated thymic T-cell export and naïve T-cell frequencies in old mice. Conversely, loss of FGF<em>21</em> function in middle-aged mice accelerated thymic aging, increased lethality, and delayed T-cell reconstitution postirradiation and hematopoietic stem cell transplantation (HSCT). Collectively, FGF<em>21</em> integrates metabolic and immune systems to prevent thymic injury and may aid in the reestablishment of a diverse T-cell repertoire in cancer patients following HSCT.

OBJECTIVE

As we approach the era of mesenchymal stem cell (MSC) application in the medical clinic, the standarization of their culture conditions are of the particular importance. We re-evaluated the influences of oxygens concentration on proliferation, stemness and differentiation of human umbilical cord Wharton Jelly-derived MSCs (WJ-MSCs).

METHODS

Primary cultures <em>growing</em> in <em>21</em>% oxygen were either transferred into 5% O2 or continued to grow under standard <em>21</em>% oxygen conditions. Cell expansion was estimated by WST1/enzyme-linked immunosorbent assay or cell counting. After 2 or 4 weeks of culture, cell phenotypes were evaluated using microscopic, immunocytochemical, fluorescence-activated cell-sorting and molecular methods. Genes and proteins typical of mesenchymal cells, committed neural cells or more primitive stem/progenitors (Oct4A, Nanog, Rex1, Sox2) and hypoxia inducible <em>factor</em> (HIF)-1α-3α were evaluated.

RESULTS

Lowering O2 concentration from <em>21</em>% to the physiologically relevant 5% level substantially affected cell characteristics, with induction of stemness-related-transcription-<em>factor</em> and stimulation of cell proliferative capacity, with increased colony-forming unit fibroblasts (CFU-F) centers exerting OCT4A, NANOG and HIF-1α and HIF-2α immunoreactivity. Moreover, the spontaneous and time-dependent ability of WJ-MSCs to differentiate into neural lineage under <em>21</em>% O2 culture was blocked in the reduced oxygen condition. Importantly, treatment with trichostatin A (TSA, a histone deacetylase inhibitor) suppressed HIF-1α and HIF-2α expression, in addition to blockading the cellular effects of reduced oxygen concentration.

CONCLUSIONS

A physiologically relevant microenvironment of 5% O2 rejuvenates WJ-MSC culture toward less-differentiated, more primitive and faster-growing phenotypes with involvement of HIF-1α and HIF-2α-mediated and TSA-sensitive chromatin modification mechanisms. These observations add to the understanding of MSC responses to defined culture conditions, which is the most critical issue for adult stem cells translational applications.

UNASSIGNED

Approximately 5%-10% of gastric cancers have a fibroblast growth factor receptor-2 (FGFR2) gene amplification. AZD4547 is a selective FGFR-1, 2, 3 tyrosine kinase inhibitor with potent preclinical activity in FGFR2 amplified gastric adenocarcinoma SNU16 and SGC083 xenograft models. The randomized phase II SHINE study (NCT01457846) investigated whether AZD4547 improves clinical outcome versus paclitaxel as second-line treatment in patients with advanced gastric adenocarcinoma displaying FGFR2 polysomy or gene amplification detected by fluorescence in situ hybridization.

UNASSIGNED

Patients were randomized 3:2 (FGFR2 gene amplification) or 1:1 (FGFR2 polysomy) to AZD4547 or paclitaxel. Patients received AZD4547 80 mg twice daily, orally, on a 2 weeks on/1 week off schedule of a 21-day cycle or intravenous paclitaxel 80 mg/m2 administered weekly on days 1, 8, and 15 of a 28-day cycle. The primary end point was progression-free survival (PFS). Safety outcomes were assessed and an exploratory biomarker analysis was undertaken.

UNASSIGNED

Of 71 patients randomized (AZD4547 n = 41, paclitaxel n = 30), 67 received study treatment (AZD4547 n = 40, paclitaxel n = 27). Among all randomized patients, median PFS was 1.8 months with AZD4547 and 3.5 months with paclitaxel (one-sided P = 0.9581); median follow-up duration for PFS was 1.77 and 2.12 months, respectively. The incidence of adverse events was similar in both treatment arms. Exploratory biomarker analyses revealed marked intratumor heterogeneity of FGFR2 amplification and poor concordance between amplification/polysomy and FGFR2 mRNA expression.

UNASSIGNED

AZD4547 did not significantly improve PFS versus paclitaxel in gastric cancer FGFR2 amplification/polysomy patients. Considerable intratumor heterogeneity for FGFR2 gene amplification and poor concordance between FGFR2 amplification/polysomy and FGFR2 expression indicates the need for alternative predictive biomarker testing. AZD4547 was generally well tolerated.

BACKGROUND

The tyrosine kinase inhibitor imatinib mesylate was developed as an inhibitor of the kinase activity of BCR-ABL. However, imatinib also has potent inhibitory activity against the platelet-derived growth factor receptor (PDGFR). Nilotinib is approved for treating patients with chronic myeloid leukemia showing resistance or intolerance to imatinib. Like imatinib, nilotinib selectively inhibits the tyrosine kinase activity of PDGFR.

OBJECTIVE

We examined the effect of imatinib and nilotinib on acute lung injury and pulmonary fibrosis in a mouse model.

METHODS

Mice were treated by intratracheal instillation of bleomycin. Imatinib or nilotinib were administered by oral gavage. To study the early inflammatory and late fibrotic phases of lung injury, mice were sacrificed on days 3, 7, 14 and 21 after bleomycin instillation.

RESULTS

Histopathology showed that imatinib and nilotinib attenuated the extent of lung injury and fibrosis. The numbers of inflammatory cells and levels of IL-6, IL-1β and tumor necrosis factor-α were decreased in the imatinib and nilotinib groups on days 3 and 7. Imatinib and nilotinib therapy significantly reduced the levels of hydroxyproline on days 14 and 21, which was accompanied by decreased expression levels of transforming growth factor (TGF)-β1 and PDGFR-β. Imatinib and nilotinib also significantly reduced the expression levels of the genes for TGF-β1 and platelet-derived growth factor (PDGF). Imatinib and nilotinib treatment also significantly inhibited the PDGF-induced proliferation of lung fibroblasts in vitro. When imatinib or nilotinib was given 7 days after the instillation of bleomycin, only nilotinib attenuated pulmonary fibrosis.

CONCLUSIONS

Imatinib and nilotinib attenuated bleomycin-induced acute lung injury and pulmonary fibrosis in mice. In a therapeutic model, nilotinib showed more potent antifibrotic effects than imatinib.

<AbstractText>Recent therapeutic advances in cardiovascular disease, thanks to the discovery of endothelial progenitor cells (EPCs). Stromal cell-derived <em>factor</em>-1α (SDF-1α), platelet-derived <em>growth</em> <em>factor</em> (PDGF), basic <em>fibroblast</em> <em>growth</em> <em>factor</em> (bFGF), and nitric oxide (NO) play a role in migration, homing, and differentiation of EPCs into mature endothelial cells. The incidence of cardiovascular disease is higher in men than in women. This fact suggests the influence of sex hormones on incidence of cardiovascular disease.</AbstractText><p><div><b>Methods</b></div>Twenty-four female wistar rats weighing 160-180 g were randomly divided into four groups (<i>N</i> = 6): 1. sham-treated by sesame oil, 2. ovariectomized (OVX)-treated by sesame oil, 3. OVX-treated by 10 μg/kg/day testosterone, and 4. OVX-treated by 100 μg/kg/day testosterone. After <em>21</em> days, the animals were euthanized and blood samples were saved for determination of EPC count and serum levels of SDF-1α, PDGF, bFGF, and NO production.</p><p><div><b>Results</b></div>High-dose testosterone induced significant increase in EPC count in OVX rats (<i>P</i> < 0.05). Also 100 μg/kg/day testosterone increased serum level of SDF-1α more than OVX-treated by 10 μg/kg/day testosterone (<i>P</i> < 0.05). But 10 μg/kg/day testosterone increased significantly the serum level of PDGF >100 μg/kg/day testosterone-treated group (<i>P</i> < 0.05). The serum level of bFGF in sham-treated by sesame oil was equal with its concentration in OVX-treated by 100 μg/kg/day testosterone. And the serum concentration of NO production in testosterone-treated groups were significantly less than other groups (<i>P</i> < 0.05).</p><AbstractText>This study suggests that testosterone might be effective on cardiovascular disease in females by increasing EPC count through SDF-1α and PDGF mechanisms which are some of the vascular healing <em>factors</em>.</AbstractText>

Restricting availability of essential amino acids (EAAs) limits aminoacylation of tRNAs by their cognate EAAs and activates the nutrient-sensing kinase, general control nonderepressible 2 (GCN2). Activated GCN2 phosphorylates eukaryotic initiation <em>factor</em> 2 (eIF2), altering gene-specific translation and initiating a transcriptional program collectively described as the integrated stress response (ISR). Central GCN2 activation by EAA deprivation is also linked to an acute aversive feeding response. Dietary methionine restriction (MR) produces a well-documented series of physiological responses (increased energy intake and expenditure, decreased adiposity, and increased insulin sensitivity), but the role of GCN2 in mediating them is unknown. Using Gcn2(-/-) mice, we found that the absence of GCN2 had no effect on the ability of MR to reduce body weight or adiposity, increase energy intake and expenditure, increase hepatic transcription and release of <em>fibroblast</em> <em>growth</em> <em>factor</em> <em>21</em>, or improve insulin sensitivity. Interestingly, hepatic eIF2 phosphorylation by MR was uncompromised in Gcn2(-/-) mice. Instead, protein kinase R-like endoplasmic reticulum (ER) kinase (PERK) was activated in both intact and Gcn2(-/-) mice. PERK activation corresponded with induction of the ISR and the nuclear respiratory <em>factor</em> 2 antioxidant program but not ER stress. These data uncover a novel glutathione-sensing mechanism that functions independently of GCN2 to link dietary MR to its metabolic phenotype.

5-hydroxytryptamine (5-HT) is a mitogen for <em>fibroblasts</em>, vascular smooth muscle cells, renal mesangial cells, and jejunal crypt cells. The human carcinoid cell line (termed BON) that we established in our laboratory from a pancreatic carcinoid tumor produces and secretes 5-HT. In this study, therefore, we examined the effect of 5-HT on <em>growth</em> of BON cells. Furthermore, by use of selective 5-HT receptor antagonists, we examined receptor and post-receptor mechanisms by which 5-HT-induced responses were produced. 5-HT stimulated <em>growth</em> of BON cells. 5-HT stimulated phosphatidylinositol (PI) hydrolysis in a dose-dependent fashion and inhibited cyclic AMP production in a dose-dependent fashion. The 5-HT1A/1B receptor antagonist, SDZ <em>21</em>-009, prevented the reduction of cyclic AMP production evoked by 5-HT and inhibited the mitogenic action of 5-HT. The 5-HT1C/2 receptor antagonist, mesulergine, competitively inhibited PI hydrolysis, but did not affect the mitogenic action of 5-HT. The mitogenic action of 5-HT and the reduction of cyclic AMP production evoked by 5-HT were also inhibited by pertussis toxin. These results suggest that 5-HT is an autocrine <em>growth</em> <em>factor</em> for BON cells and that mitogenic mechanism of 5-HT involves receptor-mediated inhibition of the production of cyclic AMP which may be linked to pertussis toxin-sensitive GTP binding protein. 8-bromo-cyclic AMP inhibited <em>growth</em> of BON cells whereas 8-bromo-cyclic GMP had no effect on cell <em>growth</em>. Involvement of protein kinase A in BON cell <em>growth</em> regulation was confirmed by the observation that a cAMP-dependent protein kinase antagonist (Rp-cAMPS) could stimulate BON cell <em>growth</em>.

OBJECTIVE

<em>Fibroblast</em> <em>growth</em> <em>factor</em> <em>21</em> (FGF<em>21</em>) is an endocrine hormone that exhibits anti-diabetic and anti-obesity activity. FGF<em>21</em> expression is increased in patients with and mouse models of obesity or nonalcoholic fatty liver disease (NAFLD). However, the functional role and molecular mechanism of FGF<em>21</em> induction in obesity or NAFLD are not clear. As endoplasmic reticulum (ER) stress is triggered in obesity and NAFLD, we investigated whether ER stress affects FGF<em>21</em> expression or whether FGF<em>21</em> induction acts as a mechanism of the unfolded protein response (UPR) adaptation to ER stress induced by chemical stressors or obesity.

METHODS

Hepatocytes or mouse embryonic fibroblasts deficient in UPR signalling pathways and liver-specific eIF2α mutant mice were employed to investigate the in vitro and in vivo effects of ER stress on FGF<em>21</em> expression, respectively. The in vivo importance of FGF<em>21</em> induction by ER stress and obesity was determined using inducible Fgf<em>21</em>-transgenic mice and Fgf<em>21</em>-null mice with or without leptin deficiency.

RESULTS

We found that ER stressors induced FGF<em>21</em> expression, which was dependent on a PKR-like ER kinase-eukaryotic translation <em>factor</em> 2α-activating transcription <em>factor</em> 4 pathway both in vitro and in vivo. Fgf<em>21</em>-null mice exhibited increased expression of ER stress marker genes and augmented hepatic lipid accumulation after tunicamycin treatment. However, these changes were attenuated in inducible Fgf<em>21</em>-transgenic mice. We also observed that Fgf<em>21</em>-null mice with leptin deficiency displayed increased hepatic ER stress response and liver injury, accompanied by deteriorated metabolic variables.

CONCLUSIONS

Our results suggest that FGF<em>21</em> plays an important role in the adaptive response to ER stress- or obesity-induced hepatic metabolic stress.

<em>Fibroblast</em> <em>growth</em> <em>factor</em> <em>21</em>, a metabolic regulator, plays roles in lipolysis and glucose uptake in adipose tissues and skeletal muscles. Its expression in skeletal muscle is upregulated upon activation of the phosphatidylinositol 3-kinase/Akt signaling pathway, which is induced by exercise and muscle contraction. We examined the increase of <em>fibroblast</em> <em>growth</em> <em>factor</em> <em>21</em> after acute exercise in metabolic organs, especially skeletal muscles and circulation. Participants exercised on bicycle ergometers for 60 min at 75% of their V˙O2max. Venous blood samples were taken before exercise and immediately after exercise. In an animal study, male ICR mice were divided into sedentary and exercise groups. Mice in the exercise group performed treadmill exercises at 30 m min(-1) for 60 min. Shortly thereafter, blood, liver, and skeletal muscle samples were taken from mice. Acute exercise induced the increase of serum <em>fibroblast</em> <em>growth</em> <em>factor</em> <em>21</em> in both humans and mice, and increased <em>fibroblast</em> <em>growth</em> <em>factor</em> <em>21</em> expression in the skeletal muscles and the liver of mice. Acute exercise activated Akt in mice skeletal muscle. Acute exercise increases <em>fibroblast</em> <em>growth</em> <em>factor</em> <em>21</em> concentrations in both serum and metabolic organs. Moreover, results show that acute exercise increased the expression of <em>fibroblast</em> <em>growth</em> <em>factor</em> <em>21</em> in skeletal muscle, accompanied by the phosphorylation of Akt in mice.

BACKGROUND

Small for gestational age (SGA)-born children comprise a heterogeneous group in which only few genetic causes have been identified.

OBJECTIVE

To determine copy number variations in 18 growth-related genes in 100 SGA children with persistent short stature.

METHODS

Copy number variations in 18 growth-related genes (SHOX, GH1, GHR, IGF1, IGF1R, IGF2, IGFBP1-6, NSD1, GRB10, STAT5B, ALS, SOCS2, and SOCS3) were determined by an "in house" multiplex ligation-dependent probe amplification kit. The deletions were further characterized by single-nucleotide polymorphism array analysis.

RESULTS

Two heterozygous de novo insulin-like growth factor 1 receptor (IGF1R) deletions were found: a deletion of the complete IGF1R gene (15q26.3, exons 1-21), including distally flanking sequences, and a deletion comprising exons 3-21, extending further into the telomeric region. In one case, serum IGF-I was low (-2.78 sd score), probably because of a coexisting growth hormone (GH) deficiency. Both children increased their height during GH treatment (1 mg/m(2) per day). Functional studies in skin fibroblast cultures demonstrated similar levels of IGF1R autophosphorylation and a reduced activation of protein kinase B/Akt upon a challenge with IGF-I in comparison with controls.

CONCLUSIONS

IGF1R haploinsufficiency was present in 2 of 100 short SGA children. GH therapy resulted in moderate catch-up growth in our patients. A review of the literature shows that small birth size, short stature, small head size, relatively high IGF-I levels, developmental delay, and micrognathia are the main predictors for an IGF1R deletion.

Major depressive disorder is often linked to stress. Although short-term stress is without effect in mice, prolonged stress leads to depressive-like behavior, indicating that an allostatic mechanism exists in this difference. Here we demonstrate that mice after short-term (1 h per day for 7 days) chronic restraint stress (CRS), do not display depressive-like behavior. Analysis of the hippocampus of these mice showed increased levels of neurotrophic <em>factor</em>-α1 (NF-α1; also known as carboxypeptidase E, CPE), concomitant with enhanced <em>fibroblast</em> <em>growth</em> <em>factor</em> 2 (FGF2) expression, and an increase in neurogenesis in the dentate gyrus. In contrast, after prolonged (6 h per day for <em>21</em> days) CRS, mice show decreased hippocampal NF-α1 and FGF2 levels and depressive-like responses. In NF-α1-knockout mice, hippocampal FGF2 levels and neurogenesis are reduced. These mice exhibit depressive-like behavior that is reversed by FGF2 administration. Indeed, studies in cultured hippocampal neurons reveal that NF-α1 treatment directly upregulates FGF2 expression through extracellular signal-regulated kinase-Sp1 signaling. Thus, during short-term CRS, hippocampal NF-α1 expression is upregulated and has a key role in preventing the onset of depressive-like behavior through enhanced FGF2-mediated neurogenesis. To evaluate the therapeutic potential of this pathway, we examined, rosiglitazone (Rosi), a PPARγ agonist, which has been shown to have antidepressant activity in rodents and humans. Rosi upregulates FGF2 expression in a NF-α1-dependent manner in hippocampal neurons. Mice fed Rosi show increased hippocampal NF-α1 levels and neurogenesis compared with controls, thereby indicating the antidepressant action of this drug. Development of drugs that activate the NF-α1/FGF2/neurogenesis pathway can offer a new approach to depression therapy.

BACKGROUND

Abnormal glucose metabolism is a central feature of disorders with increased rates of cardiovascular disease. Low levels of high-density lipoprotein (HDL) are a key predictor for cardiovascular disease. We used genetic mouse models with increased HDL levels (apolipoprotein A-I transgenic [apoA-I tg]) and reduced HDL levels (apoA-I-deficient [apoA-I ko]) to investigate whether HDL modulates mitochondrial bioenergetics in skeletal muscle.

RESULTS

ApoA-I ko mice exhibited fasting hyperglycemia and impaired glucose tolerance test compared with wild-type mice. Mitochondria isolated from gastrocnemius muscle of apoA-I ko mice displayed markedly blunted ATP synthesis. Endurance capacity during exercise exhaustion test was impaired in apoA-I ko mice. HDL directly enhanced glucose oxidation by increasing glycolysis and mitochondrial respiration rate in C2C12 muscle cells. ApoA-I tg mice exhibited lower fasting glucose levels, improved glucose tolerance test, increased lactate levels, reduced fat mass, associated with protection against age-induced decline of endurance capacity compared with wild-type mice. Circulating levels of <em>fibroblast</em> <em>growth</em> <em>factor</em> <em>21</em>, a novel biomarker for mitochondrial respiratory chain deficiencies and inhibitor of white adipose lipolysis, were significantly reduced in apoA-I tg mice. Consistent with an increase in glucose utilization of skeletal muscle, genetically increased HDL and apoA-I levels in mice prevented high-fat diet-induced impairment of glucose homeostasis.

CONCLUSIONS

In view of impaired mitochondrial function and decreased HDL levels in type 2 diabetes mellitus, our findings indicate that HDL-raising therapies may preserve muscle mitochondrial function and address key aspects of type 2 diabetes mellitus beyond cardiovascular disease.

Basic <em>fibroblast</em> <em>growth</em> <em>factor</em> (bFGF) is a potent mitogenic and angiogenic <em>factor</em> that is known to regulate GH, PRL, and TSH secretion. Sequences within a bFGF gene family member have been detected in transforming DNA samples derived from human PRL-secreting tumors. Furthermore, elevated serum concentrations of bFGF have been noted in patients with multiple endocrine neoplasia-1. To further examine the significance of bFGF in sporadic human pituitary adenomas, we investigated the expression of bFGF by these tumors. Using an enzyme-linked immunoassay that recognizes all 16-24 kilodalton molecular mass forms of bFGF, we measured circulating serum concentrations in <em>21</em> patients with sporadic pituitary adenomas; they ranged from less than 0.5-84 pg/mL and declined following surgical adenomectomy. To confirm the pituitary source of this <em>growth</em> <em>factor</em>, we determined in vitro bFGF release from 43 adenomas (10 GH, 7 PRL, 10 ACTH, 14 gonadotrope adenomas/oncocytomas, and 2 silent subtype 3 adenomas). bFGF was present with wide variability (0.75-<em>21</em>00 pg/24 h.10(5) cells) in conditioned culture media of all adenomas examined. The adenohypophysial source of this <em>growth</em> <em>factor</em> was further demonstrated by the reverse hemolytic plaque assay. Variable bFGF messenger RNA expression was identified by the reverse-transcription polymerase chain reaction technique in 9 functional (2 PRL, 5 GH, 2 ACTH) and 7 nonfunctional (1 oncocytoma, 2 null cell, 2 gonadotrope, 2 Silent Subtype 3) adenomas examined. bFGF levels were unaltered in vitro following hypothalamic hormone stimulation/inhibition. The lack of a bFGF signal peptide sequence and hypothalamic hormone-independence suggest that secretion of this <em>factor</em> may be independent of pituitary hormone regulation. Immunocytochemistry failed to localize bFGF in tumors that released this <em>factor</em> in vitro, suggesting that storage of this peptide does not correlate with its synthesis and release. In conclusion, the heterogenous expression of bFGF suggests that it may play a specific and selective role in the tumorigenic process of some pituitary adenomas.

Schwann cells (SCs) can be used to repair both the peripheral and central nervous systems. Therefore, establishment of a procedure to obtain activated, highly proliferative SCs, in an appropriate time for clinical applications, is a prerequisite. Purification is complicated by contamination with <em>fibroblasts</em> which often become the predominant cell type in an in vitro SC culture. This study describes a novel and efficient method to enrich SCs by utilizing the differential detachment properties of the two cell types. In culture, cells were treated with two different media and the chelator, EGTA, which detached SCs faster than <em>fibroblasts</em> and allowed for easy isolation of SCs. Within seven days, high yields of SCs with a purity of greater than 99% were achieved. This was confirmed by immunostaining characterization and flow-cytometric analyses using an antibody against the p75 low affinity nerve <em>growth</em> <em>factor</em> receptor (p75LNGFR). The entire procedure was completed in approximately <em>21</em> days. This method has the advantage of being technically easier, faster, and more efficient than other previously described methods. An SC culture that was about 99% homogenous was achieved.

BACKGROUND

The relationship of <em>fibroblast</em> <em>growth</em> <em>factor</em> <em>21</em> (FGF<em>21</em>) with glucose metabolism and insulin resistance has not been well characterized in community-dwelling adults.

OBJECTIVE

The objective of the study was to examine the relationship of FGF<em>21</em> with glucose metabolism and insulin resistance.

METHODS

Serum FGF<em>21</em>, fasting plasma glucose (FPG), glucose tolerance, and insulin resistance were measured in a cross-sectional study, 2002-2007.

METHODS

The study was the Baltimore Longitudinal Study of Aging, a natural history cohort study of aging in community-dwelling men and women.

METHODS

Seven hundred adults, mean age 63.3 yr, participated in the study.

METHODS

FPG, 2-h plasma glucose, homeostasis model of insulin resistance, whole-body insulin sensitivity (Matsuda index), glucose area under the curve (AUC), and insulin AUC were measured.

RESULTS

Overall, the median (25th and 75th percentiles) FGF<em>21</em> concentration was 225 (126, 370) pg/ml. The proportion of adults with normal, impaired, and diabetic FPG was 77.0, <em>21</em>.4, and 1.6%, and those with normal, impaired, and diabetic 2-h plasma glucose was 76.7, 19.1, and 4.1%, respectively. Log serum FGF<em>21</em> (picograms per milliliter), per 1 sd increase, was associated with an FPG (odds ratio 1.43, 95% confidence interval 1.15, 1.77, P = 0.001) and with 2-h plasma glucose (odds ratio 1.39, 95% confidence interval 1.12, 1.73, P = 0.003), in respective multivariate, ordered logistic regression models, adjusted for potential confounders. Serum FGF<em>21</em> (picograms per milliliter) was associated with the homeostasis model of insulin resistance, the Matsuda index, glucose AUC, and insulin AUC (all P < 0.0001) in respective multivariable linear regression models adjusted for potential confounders.

CONCLUSIONS

Higher serum FGF<em>21</em> concentrations were associated with abnormal glucose metabolism and insulin resistance in community-dwelling adults.

Mice genetically deficient in the glucagon receptor (Gcgr(-/-)) show improved glucose tolerance, insulin sensitivity, and α-cell hyperplasia. In addition, Gcgr(-/-) mice do not develop diabetes after chemical destruction of β-cells. Since <em>fibroblast</em> <em>growth</em> <em>factor</em> <em>21</em> (FGF<em>21</em>) has insulin-independent glucose-lowering properties, we investigated whether FGF<em>21</em> was contributing to diabetes resistance in insulin-deficient Gcgr(-/-) mice. Plasma FGF<em>21</em> was 25-fold higher in Gcgr(-/-) mice than in wild-type mice. FGF<em>21</em> was found to be expressed in pancreatic β- and α-cells, with high expression in the hyperplastic α-cells of Gcgr(-/-) mice. FGF<em>21</em> expression was also significantly increased in liver and adipose tissue of Gcgr(-/-) mice. To investigate the potential antidiabetic actions of FGF<em>21</em> in insulin-deficient Gcgr(-/-) mice, an FGF<em>21</em>-neutralizing antibody was administered prior to oral glucose tolerance tests (OGTTs). FGF<em>21</em> neutralization caused a decline in glucose tolerance in insulin-deficient Gcgr(-/-) mice during the OGTT. Despite this decline, insulin-deficient Gcgr(-/-) mice did not develop hyperglycemia. Glucagon-like peptide 1 (GLP-1) also has insulin-independent glucose-lowering properties, and an elevated circulating level of GLP-1 is a known characteristic of Gcgr(-/-) mice. Neutralization of FGF<em>21</em>, while concurrently blocking the GLP-1 receptor with the antagonist Exendin 9-39 (Ex9-39), resulted in significant hyperglycemia in insulin-deficient Gcgr(-/-) mice, while blocking with Ex9-39 alone did not. In conclusion, FGF<em>21</em> acts additively with GLP-1 to prevent insulinopenic diabetes in mice lacking glucagon action.

The multifunctional cytokine interleukin 6 (IL-6) has direct <em>growth</em>, survival and differentiation effects on peripheral and central neurons. Furthermore, it can modulate the production by non-neuronal cells of other cytokines and <em>growth</em> <em>factors</em>, and thereby affect nerve cells indirectly. We have studied IL-6 expression and production in intact and injured peripheral nerves of C57/BL/6NHSD mice, which display the normal rapid progression of Wallerian degeneration. The IL-6 mRNA was detected in nerves degenerating in vitro or in vivo, but not in intact nerves. In vitro- and in vivo-degenerating nerve segments and neuroma nerve segments synthesized and secreted IL-6. The onset of IL-6 production was rapid and prolonged. It was detected as early as 2 h after injury and persisted for the entire period of <em>21</em> days tested after the injury. Of the non-neuronal cells that reside in intact and injured nerves, macrophages and <em>fibroblasts</em> were the major contributors to IL-6 production. We also studied IL-6 production in intact and injured nerves of mutant C57BL/6-WLD/OLA/NHSD mice, which display very slow progression of Wallerian degeneration. Injured nerves of C57BL/6-WLD/OLA/NHSD mice produced significantly lower amounts of IL-6 than did rapidly degenerating nerves of C57/BL/6NHSD mice.

OBJECTIVE

This in vivo study was designed to investigate the efficacy of ENMD-2076, a small-molecule kinase inhibitor with activity against the Aurora kinases A and B, and several other tyrosine kinases linked to cancer, including vascular endothelial growth factor receptor 2, cKit, and fibroblast growth factor receptor 1, against murine xenograft models of human colorectal cancer (CRC).

METHODS

HT-29 CRC cell line xenografts were treated with either vehicle or ENMD-2076 (100 or 200 mg/kg) orally daily for 28 days. Tumor growth inhibition, dynamic contrast-enhanced magnetic resonance imaging, and (18)FDG-positron emission tomography were conducted to assess the antiproliferative, antiangiogenic, and antimetabolic responses, respectively. Effects on proliferation were also analyzed by immunohistochemical methods. Additionally, three patient-derived xenografts from primary and metastatic sites were treated with ENMD-2076 (100 mg/kg) and assessed for tumor growth inhibition.

RESULTS

In the HT-29 xenograft model, ENMD-2076 induced initial tumor growth inhibition followed by regression. Treatment was associated with significant tumor blanching, indicating a loss of vascularity and substantial reductions in tumor vascular permeability and perfusion as measured by dynamic contrast-enhanced magnetic resonance imaging. Positron emission tomography scanning showed significant decreases in (18)FDG uptake at days 3 and 21 of treatment, which was associated with a marked reduction in proliferation as assessed by Ki-67. All three of the patient-derived xenografts tested were sensitive to treatment with ENMD 2076 as measured by tumor growth inhibition.

CONCLUSIONS

ENMD-2076 showed robust antitumor activity against cell line and patient-derived xenograft models of CRC that is detectable by functional imaging, supporting clinical investigation of this agent in CRC.