Therapeutic utilities of fibroblast growth factor 19

Introduction: Diabetes and associated metabolic conditions have reached pandemic proportions worldwide and there is a clear unmet medical need for new therapies that are both effective and safe. FGF19 is a distinctive member of the FGF family that functions as an endocrine hormone.

Areas covered: An up-to-date report on the exciting findings related to the involvement of FGF19 in the regulation of glucose, bile acid metabolism and energy expenditure. The role of FGF receptors in these different activities. The therapeutic potential of FGF19 and the engineering opportunities for removing undesirable mitogenic activity.

Expert opinion: The ability of FGF19 to regulate bile acid homeostasis, gallbladder filling and tumor development and its potent ability to normalize glucose, lipid and energy homeostasis have made it a potential therapeutic target for the treatment of patients with gallstones, cancer and metabolic diseases, among others. Its potential utility as a novel therapeutic for both type 1 and type 2 diabetes is of particular interest. The ability to separate the undesired mitogenic activity from its potent metabolic activities has opened new opportunities for the development of potential therapeutic molecules based on FGF19 in treating various conditions associated with metabolic syndrome.     

Therapeutic utilities of fibroblast growth factor 19

INTRODUCTION: Diabetes and associated metabolic conditions have reached pandemic proportions worldwide and there is a clear unmet medical need for new therapies that are both effective and safe. FGF19 is a distinctive member of the FGF family that functions as an endocrine hormone. AREAS COVERED: An up-to-date report on the exciting findings related to the involvement of FGF19 in the regulation of glucose, bile acid metabolism and energy expenditure. The role of FGF receptors in these different activities. The therapeutic potential of FGF19 and the engineering opportunities for removing undesirable mitogenic activity. EXPERT OPINION: The ability of FGF19 to regulate bile acid homeostasis, gallbladder filling and tumor development and its potent ability to normalize glucose, lipid and energy homeostasis have made it a potential therapeutic target for the treatment of patients with gallstones, cancer and metabolic diseases, among others. Its potential utility as a novel therapeutic for both type 1 and type 2 diabetes is of particular interest. The ability to separate the undesired mitogenic activity from its potent metabolic activities has opened new opportunities for the development of potential therapeutic molecules based on FGF19 in treating various conditions associated with metabolic syndrome.     

Mini-review: endocrine actions of fibroblast growth factor 19

Fibroblast growth factor (FGF) 19 is an atypical member of the fibroblast growth factor family of signaling molecules. FGF19, FGF21, and FGF23 comprise a phylogenetic subfamily with attributes that distinguish them from typical FGFs. The FGF19 subfamily has reduced heparin binding resulting from a disrupted beta-trefoil domain. Reduced heparin binding allows these FGFs to diffuse beyond their site of origin and act as endocrine hormones. This family of FGFs is regulated, at least in part, by nuclear hormone receptors. FGF19 expression is regulated by the farnesoid X receptor, a nuclear hormone receptor that is a key regulator of bile acid biosynthesis and transport. In line with its regulation by a bile acid receptor, FGF19 is involved in the regulation of bile acid biosynthesis and gallbladder filling. FGF19 originates from intestine and signals to liver via the portal circulation with a pronounced diurnal pattern. FGF19 is the only FGF to not have a closely related mouse homologue. The mouse homologue of FGF19, called FGF15, is only 53% identical to the human FGF19. FGF19 transgenic mice and mice administered exogenous FGF19 are resistant to the effects of a high fat diet, suggesting FGF19 may play a role in metabolic signaling pathways. Hepatocellular carcinoma is seen in mice, predominantly female mice, exposed to FGF19. Further investigation into the cellular mechanisms involved in these activities will allow better understanding of FGF19 biology in the context of human physiology.     

Population pharmacokinetics of recombinant factor XIII in cynomolgus monkeys

Hemostasis in humans and other animals is a complex process that controls blood loss after a vascular injury. Factor XIII (FXIII) stabilizes clots primarily by cross-linking fibrin, thus protecting a newly formed clot from fibrinolysis by plasmin. Congenital deficiencies in humans involving FXIII are associated with delayed bleeding and wound healing and severe spontaneous hemorrhaging. These symptoms can be alleviated by intravenous administration of enriched FXIII plasma fractions. Circulating plasma FXIII is found as a heterotetramer that dissociates in the presence of calcium and thrombin into an active dimer and 2 inactive monomers. The recombinant FXIII under investigation is the active dimer alone. A 3-compartment, nonlinear population pharmacokinetic model was implemented in NONMEM V and then used to analyze data from preclinical studies in cynomolgus monkeys. The model simultaneously describes endogenous production of dimer (0.622 microg kg(-1) hr(-1)) and monomer (12.1 microg kg(-1) hr(-1)), and the administration of recombinant dimer. The model incorporates the rate and extent of complexation of recombinant dimer with available endogenous monomer (6.59 mg(-1) kg hr(-1)) to form the heterotetramer. Half-lives for dimer, heterotetramer, and monomer (3.33 hours, 2.83 days, and 3.94 hours for A(2), A(2)B(2), and B, respectively) were estimated, along with their variability in the population studied.     

成纤维细胞生长因子受体拮抗剂AZD4547的合成工艺改进

目的改进成纤维细胞生长因子受体拮抗剂AZD4547(1)的合成方法。方法以3,5-二甲氧基苯甲醛(2)为起始原料,经过羟醛缩合、催化氢化、酯化反应制备3-(3,5-二甲氧基苯基)丙酸乙酯(5),5通过分步法或者一锅法制得关键中间体5-(3,5-二甲氧基苯基乙基)-1H-吡唑-3-胺(7)。7再与4-((3S,5R)-3,5-二甲基哌嗪基-1-基)苯甲酸乙酯(9)反应生成酰胺,最终合成目标物AZD4547(1)。结果与结论分步法和一锅法分别将化合物7的收率由文献中的42.0%提高到86.0%和54.0%(以5计)。分步法显著地提高了化合物7的收率,一锅法操作更加简便,反应条件更加安全、温和。     

Targeting fibroblast growth factor 19 in liver disease: a potential biomarker and therapeutic target

Introduction: Fibroblast growth factor 19 (FGF19) is a member of the hormone-like FGF family and has activity as an ileum-derived postprandial hormone. It shares high binding affinity with β-Klotho and together with the FGF receptor (FGFR) 4, is predominantly targeted to the liver. The main function of FGF19 in metabolism is the negative control of bile acid synthesis, promotion of glycogen synthesis, lipid metabolism and protein synthesis.

Areas covered: Drawing on in vitro and in vivo studies, this review discusses FGF19 and some underlying mechanisms of action of FGF19 as an endocrine hormone in several liver diseases. The molecular pathway of the FGF19-FGFR4 axis in non-alcoholic liver disease and hepatocellular carcinoma are discussed. Furthermore, definition of function and pharmacological effects of FGF19 for liver disease are also presented.

Expert opinion: A series of studies have highlighted a crucial role of FGF19 in liver disease. However, the conclusions of these studies are partly paradoxical and controversial. An understanding of the underlying biological mechanisms which may explain inconsistent findings is especially important for consideration of potential biomarker strategies and an exploration of the putative therapeutic efficacy of FGF19 for human liver disease.     

注射用重组人成纤维细胞生长因子-21食蟹猴药动学研究

目的 研究注射用重组人成纤维细胞生长因子-21（FGF-21）在食蟹猴体内单次和多次皮下给药后的药代动力学特征。方法 采用随机、平行和剂量递增设计,18只食蟹猴分别单次sc150、300和600 μg/kg的FGF-21或多次sc 300 μg/kg的FGF-21,按设计采集动态血清样本。采用双抗体夹心ELISA法检测血清中药物浓度的动态变化,采用DAS 3.2.4药动程序拟合并计算药动参数。结果 食蟹猴单次sc FGF-21后,各剂量组峰浓度C_max和药时曲线下面积AUC_（0-24h）、AUC_（0-∞）均随给药剂量的增加而增大,C_max、AUC_（0-24h）和AUC_（0-∞）三者均与剂量呈线性相关,各剂量组t_1/2Z、T_max、CL_z和V_z均较为一致。与单次给药相比,食蟹猴多次sc给药后的t_1/2z有所延长但其他主要PK参数（T_max、V_z和CL_z等）均较为一致,多次给药后,体内药物无蓄积倾向。结论 食蟹猴单次sc FGF-21后,在150~600 μg/kg剂量范围内呈现线性动力学特征。单次与多次sc给予FGF-21后,两者的PK行为特征基本一致,无明显药物蓄积。     

注射用重组人成纤维细胞生长因子-21食蟹猴急性毒性试验研究

目的 观察食蟹猴单次sc注射用重组人成纤维细胞生长因子-21（RH-FGF-21）的急性毒性反应。方法 8只健康食蟹猴,随机分成RH-FGF-21组和对照组,RH-FGF-21组6只,对照组2只,均雌雄各半,分别单次sc最大给药浓度和最大给药体积的供试品RH-FGF-21（9.0 mg/kg）和最大体积的对照品灭菌注射用水（1.0 mL/kg）,给药后连续观察21 d。在给药前适应期和给药后观察期内进行动物的一般观察（外观、行为、饮食、反应能力、分泌物和排泄物等）、死亡情况、体质量变化、肛温、进食量、眼科和心电图检查、血液学和血液生化学检测、尿液观察和分析;观察期结束安乐死全部存活动物,进行组织病理学检查。结果 动物体质量、肛温、进食量、心电图检查和眼科检查与同期对照组比较均未见明显异常;血液学检测、血液生化检测、尿液观察和分析结果、组织病理学检查也未见由药物引起的异常变化。结论 在本试验条件下未发现由药物引起的急性毒性症状,9.0 mg/kg可认为是食蟹猴单次sc RH-FGF-21的最大给药量。     

Basic fibroblast growth factor and keratinocyte growth factor over-expression in benign prostatic hyperplasia

The prostate growth is under the indirect control of androgens through the medium of many growth factors. The fibroblast growth factors (FGFs) seem to play an important part in stimulating the development of this organ. In this work, the expression of two FGFs: bFGF (or FGF2) and KGF (or FGF7), was studied in RT-PCR and semi-quantified in densitometry. Both genes expression was increased in BPH in comparison with normal prostates. A two to three times and a 1.5 to four times over-expressions were observed for bFGF and KGF, respectively. An over-expression of these growth factors could lead to a cell multiplication resulting in a pathological development of the prostate size. Moreover, bFGF and KGF act in parallel in the prostate, one stimulating the prostatic stroma and the other one stimulating the epithelium. These two growth factors could participate in the increase of the two tissues constituting the prostate.     

Developmental toxicity assessment of tanezumab,an anti-nerve growth factor monoclonal antibody,in cynomolgus monkeys (Macaca fascicularis)

Two intravenous studies with tanezumab, an anti-nerve growth factor monoclonal antibody, were conducted in pregnant cynomolgus monkeys to assess potential effects on pregnancy and pre- and postnatal development. Study 1 evaluated infants up to 12 months of age following weekly maternal dosing (0, 0.5, 4 or 30 mg/kg; 18 per group) from gestation day (GD) 20 through parturition. Study 2 evaluated infants 2 months postnatally following weekly maternal dosing (0, 0.5 or 30 mg/kg; 20–21 per group) from GD 20 through 48. In the absence of maternal toxicity, tanezumab increased stillbirth and post-birth infant mortality/morbidity, decreased infant growth and resulted in microscopic changes in the peripheral sympathetic and sensory nervous system of the infants at all doses. Decreased primary antibody responses and increased incidences in skin changes in infants were also observed. The no-observed-adverse-effect-level for maternal toxicity was 30 mg/kg and <0.5 mg/kg for developmental toxicity.     

Chronic antidepressant treatments increase basic fibroblast growth factor and fibroblast growth factor-binding protein in neurons

One of the mechanisms proposed for antidepressant drugs is the enhancement of synaptic connections and plasticity in the hippocampus and cerebral cortex. Fibroblast growth factor 2 (FGF2) is a growth factor essential for the proper formation of synaptic connections in the cerebral cortex, maturation and survival of catecholamine neurons, and neurogenesis. In this report, we attempted to establish a correlation between antidepressant treatments and FGF2 expression in the cerebral cortex and hippocampus, two brain areas relevant for depression. Desipramine (DMI, 10 mg/kg) or fluoxetine (FLU, 5 mg/kg) was injected acutely (single injection) or chronically (daily injection for two weeks) in adult rats. Chronic, but not acute, antidepressant treatments increase FGF2 immunoreactivity in neurons of the cerebral cortex and in both astrocytes and neurons of the hippocampus. FGF2 immunoreactivity in the cortex was increased mainly in the cytoplasm of neurons of layer V. Western blot analyses of nuclear and cytosolic extracts from the cortex revealed that both antidepressants increase FGF2 isoforms in the cytosolic extracts and decrease accumulation of FGF2 immunoreactivity in the nucleus. To characterize the anatomical and cellular specificity of antidepressants, we examined FGF-binding protein (FBP), a secreted protein that acts as an extracellular chaperone for FGF2 and enhances its activity. DMI and FLU increased FBP immunoreactivity in both cortical and hippocampal neurons. Our data suggest that FGF2 and FBP may participate in the plastic responses underlying the clinical efficacy of antidepressants.     

Possible mechanism for lead inhibition of vascular endothelial cell proliferation: a lower response to basic fibroblast growth factor through inhibition of heparan sulfate synthesis.

Although lead inhibits the proliferation of vascular endothelial cells, the mechanism has been incompletely understood. A lower response to basic fibroblast growth factor (bFGF) of growing bovine aortic endothelial cells after exposure to lead was investigated using a cell culture system in the present study. It was shown that lead significantly decreased the incorporation of [3H]thymidine into the acid-insoluble fraction of the cells but the inhibition disappeared in the presence of bFGF neutralizing antibody. Pretreatment with lead resulted in a reduction of the stimulation by exogenous bFGF on the [3H]thymidine incorporation. Lead decreased endogenous bFGF bound to cell surface heparan sulfate proteoglycans in a concentration-dependent manner but not the high affinity FGF receptor without a change of the accumulation within the cells. In spite of such a change in the endogenous bFGF distribution, the total amount of the growth factor synthesized was not significantly changed by lead. Although the binding of [125I]bFGF to heparan sulfate proteoglycans can be directly inhibited by lead, the inhibition was not so marked. On the other hand, lead markedly suppressed the incorporation of [35S]sulfate into heparan sulfate accumulated in the cell layer and the conditioned medium, suggesting that the metal inhibited the synthesis of the glycosaminoglycan in growing endothelial cells. Inhibition of the [3H]thymidine incorporation by lead was significantly restored by heparin. Since the binding of bFGF to its receptor is strongly promoted by heparan sulfate, the present data suggest that lead inhibits vascular endothelial cell proliferation by induction of a lower response to endogenous bFGF through a suppression of heparan sulfate synthesis.     

碱性成纤维细胞生长因子与转化生长因子β1在类风湿关节炎滑膜组织中的表达

目的了解类风湿关节炎(RA)滑膜组织中碱性成纤维细胞生长因子(bFGF)与转化生长因子β1(TGF-β1)的表达分布情况,探讨其与RA发病机制的关系.方法应用免疫组织化学SABC法对24例RA及4例正常滑膜组织中bFGF、TGF-β1的表达分布情况进行观察分析.结果 21/24例RA滑膜组织衬里层的巨噬细胞样细胞、成纤维细胞、浸润的炎症细胞与血管内皮细胞、细胞间质可见bFGF的表达分布,并且巨噬细胞样细胞、成纤维细胞、浸润的炎症细胞的阳性程度强于血管内皮细胞、细胞间质.22/24例RA滑膜组织衬里层与衬里下层的成纤维细胞、巨噬细胞样细胞、血管内皮细胞均见TGF-β1的阳性表达分布.两者比较,阳性细胞的染色程度、染色细胞数与分布范围大致相等.4例正常滑膜组织中bFGF、TGF-β1的表达分布均为阴性.结论 RA滑膜组织中bFGF、TGF-β1的表达分布均较正常增多且表达程度大致相等,两者协同作用,参与了RA病理过程的滑膜衬里层增生、炎症细胞浸润、血管增殖与滑膜血管翳的形成及对骨与软骨的破坏.     

The potential of fibroblast growth factor/fibroblast growth factor receptor signaling as a therapeutic target in tumor angiogenesis

Introduction: Fibroblast growth factors (FGFs) are endowed with a potent pro-angiogenic activity. Activation of the FGF/FGF receptor (FGFR) system occurs in a variety of human tumors. This may lead to neovascularization, supporting tumor progression and metastatic dissemination. Thus, a compelling biologic rationale exists for the development of anti-FGF/FGFR agents for the inhibition of tumor angiogenesis in cancer therapy.

Areas covered: A comprehensive search on PubMed was performed to identify studies on the role of the FGF/FGFR system in angiogenesis. Endothelial FGFR signaling, the pro-angiogenic function of canonical FGFs, and their role in human tumors are described. In addition, experimental approaches aimed at the identification and characterization of nonselective and selective FGF/FGFR inhibitors and their evaluation in clinical trials are summarized.

Expert opinion: Different approaches can be envisaged to inhibit the FGF/FGFR system, a target for the development of ‘two-compartment’ anti-angiogenic/anti-tumor agents, including FGFR selective and nonselective small-molecule tyrosine kinase inhibitors, anti-FGFR antibodies, and FGF ligand traps. Further studies are required to define the correlation between tumor vascularization and activation of the FGF/FGFR system and for the identification of cancer patients more likely to benefit from anti-FGF/FGFR treatments. In addition, advantages and disadvantages about the use of selective versus non-selective FGF inhibitors remain to be elucidated.     

Effects of the inhibition of intestinal P‐glycoprotein on aliskiren pharmacokinetics in cynomolgus monkeys

Aliskiren is a substrate for P‐glycoprotein (P‐gp) and is metabolized via cytochrome P450 3A4 (CYP3A4). The aim of the present study was to assess whether P‐gp influenced the pharmacokinetics of aliskiren and also if drug–drug interactions (DDIs) mediated through P‐gp could be reproduced in cynomolgus monkeys. The study investigated the pharmacokinetics of aliskiren in mdr1a/1b gene‐deficient (P‐gp KO) and wild‐type (WT) mice. The area under the plasma concentration–time curve (AUC) following the oral administration of aliskiren was 6.9‐fold higher in P‐gp KO mice than in WT mice, while no significant differences were observed in the AUC or total plasma clearance following the intravenous administration of aliskiren to P‐gp KO mice. Then the pharmacokinetics of aliskiren were evaluated and DDIs between aliskiren and P‐gp inhibitors, such as cyclosporin A (CsA) and zosuquidar, examined in cynomolgus monkeys. The AUC for aliskiren were 8.3‐ and 42.1‐fold higher after the oral administration of aliskiren with the concomitant oral administration of zosuquidar and CsA at doses of 10 and 30 mg/kg, respectively. In contrast, the AUC after the intravenous and oral administration of aliskiren was not significantly affected by the oral administration of zosuquidar or intravenous administration of CsA, respectively. These results indicated that P‐gp strictly limited the intestinal absorption of aliskiren in mice and monkeys, and also that the effects of intestinal P‐gp inhibition by CsA or zosuquidar on the pharmacokinetics of aliskiren were sensitively reproduced in monkeys. In conclusion, aliskiren can be used as a sensitive substrate to evaluate intestinal P‐gp inhibition in monkeys. Copyright © 2014 John Wiley & Sons, Ltd.     

Infliximab downregulates basic fibroblast growth factor and vascular endothelial growth factor in Crohn's disease patients

BACKGROUND: The use of infliximab in the treatment of Crohn's disease patients with symptomatic stenosis is controversial. AIM: To explore the influence of this agent on intestinal fibrogenesis by measuring in infliximab-treated Crohn's disease patients the serum levels of basic fibroblast growth factor and vascular endothelial growth factor, two factors known to be involved in the process of intestinal wound healing and fibrosis in this condition. METHODS: Serum levels of basic fibroblast growth factor and vascular endothelial growth factor were determined by enzyme-linked immunosorbent assay in 22 patients with steroid refractory or fistulizing Crohn's disease before, during (2 weeks) and after 12 weeks of treatment with infliximab, administered at week 0, 2 and 6 in a dose of 5 mg/kg. RESULTS: A substantial improvement in 19 of the 22 Crohn's disease patients was accompanied by a rapid and durable reduction in basic fibroblast growth factor and vascular endothelial growth factor serum levels. CONCLUSIONS: The action of infliximab in reducing serum basic fibroblast growth factor and vascular endothelial growth factor would seem to suggest a role of this agent in down-regulating the process of intestinal fibrogenesis in Crohn's disease.     

碱性成纤维细胞生长因子的药学研究进展

碱性成纤维细胞生长因子（bFGF）是成纤维细胞生长因子蛋白家族中的一员,是哺乳动物和人体中一种非常微量的活性多肽类物质,因其具有广泛的生理功能和重要的临床应用价值而受到国内外学者的高度重视。文中综述了bFGF的药理学、药效学及新型给药系统等方面的最新研究进展,旨在为bFGF的药学应用研究提供参考。