成纤维细胞生长因子21对1型糖尿病动物模型的肝糖代谢影响及机制研究

成纤维细胞生长因子(FGF)-21是FGF家族的成员之一.作为近年发现的一种新的糖代谢调节因子,大量研究表明,FGF-21是一种不依赖胰岛素,能够独立降糖的2型糖尿病治疗潜力型药物.但是,能否应用于1型糖尿病的治疗,国内外目前尚无报道.通过改良传统造模方法,诱导小鼠缓慢产生糖耐量异常,研究FGF-21对此类模型的糖代谢影响及肝糖代谢机制.通过检测FGF-21短期注射和长期注射后模型动物血糖的变化,研究FGF-21在模型动物上对血糖的调控效果.采用实时定量PCR检测FGF-21对模型动物肝脏中葡萄糖转运蛋白(GLUT)1、4 mRNA的表达影响.利用蒽酮法检测模型动物肝脏中糖原合成量.实验结果显示,FGF-21能够调节1型糖尿病动物的血糖水平,并呈剂量依赖性.同时,首次在1型糖尿病动物模型上证实了低剂量FGF-21(0.125 mg/kg)与胰岛素的协同作用效果优于相同剂量FGF-21和胰岛素单独注射的效果.治疗结果表明,FGF-21能够维持1型糖尿病动物模型血糖在正常范围,效果优于胰岛素.实时定量PCR结果发现,与胰岛素上调GLUT4 mRNA表达量不同的是,FGF-21作用动物模型8周后,GLUT1 mRNA表达量显著提高,长期的FGF-21与胰岛素协同注射使GLUT1、4 mRNA表达量同时显著提高.长期FGF-21与胰岛素协同注射组和高剂量FGF-21注射均可显著提高模型动物肝糖原的合成.结果表明,FGF-21促进动物模型糖代谢机制与增加GLUT1表达、增加糖原合成作用有关.为临床应用FGF-21治疗1型糖尿病,增加胰岛素敏感性提供了理论依据.     

FGF21的代谢调控及临床应用

成纤维细胞生长因子21(fibroblast growth factor 21,FGF21)是一种新型的参与代谢调控的关键分子,对降低体重和增加机体胰岛素敏感性具有十分显著的作用。大量的临床前和临床研究结果显示,FGF21是治疗肥胖和2型糖尿病潜在的药物靶点,该文从肝脏、脂肪和神经系统等组织入手,对FGF21调控代谢的分子作用机制及临床研究进展作一综述。     

精氨酸修饰成纤维细胞生长因子21及修饰后蛋白体内稳定性和糖代谢调节作用的研究

成纤维细胞生长因子21(fibroblast growth factor21,FGF21)是2000年发现的一个不依赖胰岛素调节血糖的细胞因子,有望成为治疗糖尿病的候选药物.但是,野生型FGF21由于半衰期较短,在体内不稳定,从而影响其成药性.为提高FGF21的稳定性,本实验在FGF21的C端添加了2个精氨酸(arginine,Arg),命名为FGF21-2A,用Compute pI/Mw软件计算之后,等电点(isoelectric point,pI)从5.43上升到5.84,随后进行了蛋白质的表达、分离纯化、体内稳定性及糖代谢调节作用的研究.诱导表达后菌液的SDS-PAGE图经BandScan5.0分析后显示FGF21-2A的表达量相对于野生型FGF21提高了10.6%.家兔体内半衰期检测实验结果显示FGF21-2A的半衰期显著延长.GOD-POD法检测HepG2肝癌细胞葡萄糖吸收实验、糖尿病小鼠降血糖实验和肝糖原检测实验的结果证明,FGF21-2A的降糖效果得到了增强,并且持续时间相对于野生型FGF21显著延长.Real-time PCR结果发现,长期注射FGF21-2A显著提高了糖尿病小鼠肝脏内葡萄糖转运蛋白(GLUT)1和葡萄糖激酶(GK)mRNA的表达量,降低了葡萄糖-6-磷酸酶(G6P)的mRNA表达量,表明FGF21-2A调节糖代谢的机制与野生型FGF21一致.综上所述,精氨酸修饰的FGF21其蛋白质稳定性提高,进而增加了对血糖的调控效果,有望成为新型糖尿病药物.     

成纤维细胞生长因子21:参与代谢调节的细胞因子

成纤维细胞生长因子21(FGF21)作为新近发现的内源性调节物质代谢因子,可由人体两大内分泌器官肝脏及骨骼肌分泌,其在调节代谢性疾病方面的生理作用近年来被医学界密切关注.大量研究发现FGF21可增加能量消耗、降低血浆与肝脏甘油三脂及低密度脂蛋白水平;调节葡萄糖代谢,发挥增强脂肪细胞摄取葡萄糖能力、降低血糖及抑制胰高血糖素分泌的作用.在临床2型糖尿病及非酒精性脂肪肝患者血浆中FGF21水平与对照组的显著差异具有统计学意义,且在控制其它因素后,其与病情的预后显著相关.而对于心血管病患者,FGF21可能通过其各项生理作用,拮抗心肌细胞凋亡及增强心肌抗氧化能力,一定程度上延缓心血管疾病的发生发展,但FGF21上述调节代谢相关性疾病的生理作用机制及途径目前尚不完全明确.本文简述FGF21的生物学特性及在代谢性疾病中的研究进展.     

FGF1:一种治疗糖尿病的新型潜在药物

糖尿病是一种常见的内分泌代谢性疾病,它及其并发症的治疗是现代医学仍未解决的难题。常见的药物治疗有诸多不良反应,譬如胰岛素的长期使用会产生胰岛素耐受性。近年研究发现,酸性成纤维细胞因子（Fibroblast growth factor 1,FGF1或aFGF）及其衍生物能够使2型糖尿病小鼠的血糖快速恢复至正常水平,并且具有胰岛素增敏效果,规避了胰岛素治疗产生耐受性的问题。因此,人们对FGF1及其衍生物在开发新型T2DM疗法方面给予诸多期待。该综述系统介绍了FGF1的结构与功能、降糖功效的机制及新发现,对FGF1的2种注射方式和FGF家族在降糖作用方面进行了比较,并对FGF1在治疗糖尿病方面的研究进程进行展望,旨在为调节血糖、解决胰岛素耐受性问题提供一种新的思路和方法。     

人源FGF-21在脂肪细胞糖代谢中的作用

近年来研究发现,成纤维细胞生长因子(FGF)-21是一种新的代谢调节因子.为了深入研究人源FGF-21（hFGF-21）的生物活性,本实验利用SUMO高效表达载体,高效表达成熟的hFGF-21,并利用小鼠3T3-L1脂肪细胞检测hFGF-21的糖代谢活性．实验结果表明,hFGF-21可促进脂肪细胞的葡萄糖吸收,且葡萄糖吸收效率呈剂量依赖性．hFGF-21作用4 h即可促进脂肪细胞糖吸收,其活性可持续24 h以上．hFGF-21与胰岛素共同作用的葡萄糖吸收效果,明显优于它们的单独作用结果,说明hFGF-21与胰岛素发挥协同作用．脂肪细胞经hFGF-21预处理后,显著增加了胰岛素促进脂肪细胞吸收葡萄糖的效率,说明hFGF-21可以增加胰岛素的敏感性．本实验为临床应用hFGF-21治疗糖尿病,增加胰岛素敏感性提供了依据．     

成纤维细胞生长因子21对糖脂代谢调控的研究进展

成纤维细胞生长因子21(FGF21)是成纤维细胞生长因子(FGF)家族中的一员。由于它在改善能量代谢方面的积极作用,近年来获得了广泛的关注。FGF21可作用于多个组织参与调控糖脂代谢:减轻体重,改善肥胖、糖尿病等病理情况下的高血糖及高血脂;此外,FGF21在调节饥饿等特殊生理状态的能量代谢中也起着重要的作用。本文就FGF21调控糖脂代谢的研究进展作一综述,以便更好地理解其作用机制,为慢性代谢性疾病的防治提供依据。     

Nature：糖尿病患者新福音

FGF1蛋白可高效恢复小鼠血糖水平饮食诱导的小鼠糖尿病等同于人类2型糖尿病，一项新研究发现单次注射蛋白质FGF1足以恢复小鼠血糖水平到正常范围，并且FGF1的这一功效会持续两天以上。这一发现由Salk科学家完成。并发表在Nature杂志上，新的研究发现可能导致出现新一代更安全。更有效的糖尿病治疗药物。 研究小组发现持续的蛋白质FGF1治疗不只是控制住血糖，同时也逆转胰岛素的不敏感（糖尿病的根本生理原因）。同样令人兴奋的，新发现的治疗蛋白FGF1不会导致当前糖尿病治疗药物常见的副作用。     

成纤维细胞生长因子21的研究进展*

成纤维细胞生长因子21（fibroblast growth factor 21,FGF21）是一种主要的脂肪代谢调节因子,主要在肝脏中表达;FGF21有助于肝脏的脂肪代谢以及生酮反应,可以促进脂肪细胞摄取葡萄糖,促进胰岛素分泌,延缓肿瘤的发展等功能。近年来研究过程中发现,FGF21可以用于糖尿病和降血脂等其他代谢疾病治疗。主要对FGF21的特点,作用机理及其分子机制进行了概括,并对FGF21在糖尿病治疗和降血脂方面的研究进行了综述。     

聚乙二醇修饰的成纤维细胞生长因子-21的降血糖作用

成纤维细胞生长因子-21(FGF-21)是FGF家族的一员．现有大量研究表明,FGF-21是除胰岛素以外的一种新的血糖调节因子,有望成为治疗2型糖尿病的新型药物．然而,FGF-21在动物体内稳定性较差,半衰期较短,严重影响了其在临床上的应用．为解决这些问题,本实验采用分子质量为20 ku的单甲氧基聚乙二醇-丙醛(mPEG-ALD)对鼠源FGF-21(mFGF-21)进行N端定点修饰,以改善mFGF-21的性质(如提高体内半衰期、降低免疫原性等)．本文研究了反应pH、反应时间、蛋白质浓度及反应物之间的质量比对mFGF-21与聚乙二醇(PEG)合成反应的影响．采用Capto Q阴离子交换层析或Superdex 75凝胶过滤层析分离纯化聚乙二醇化mFGF-21(PEG-mFGF-21),并最终确定了mFGF-21 聚乙二醇修饰的反应条件和分离PEG-mFGF-21的纯化工艺．随后分别进行了PEG-mFGF-21的理化性质(大小、纯度和体外稳定性)、免疫原性、体内半衰期、体外葡萄糖吸收活性及体内降糖活性的研究．体外稳定性实验结果显示,mFGF-21经PEG修饰后温度稳定性和抗蛋白酶水解稳定性都显著提高．间接ELISA方法检测血清中mFGF-21抗体水平及目标蛋白含量的结果表明,PEG修饰mFGF-21可明显降低其免疫原性,延长体内半衰期．HepG2细胞的葡萄糖吸收实验结果发现,PEG-mFGF-21的细胞活性并没有下降,反而随着刺激细胞时间的延长,经PEG-mFGF-21刺激的细胞葡萄糖吸收显著高于mFGF-21刺激的细胞葡萄糖吸收．2型糖尿病db/db小鼠短期血糖调控实验结果表明,mFGF-21降糖速度快于PEG-mFGF-21,但其持续时间较PEG-mFGF-21短;长期血糖调控实验结果显示,PEG-mFGF-21长期降糖效果优于mFGF-21,作用持续时间长,并且PEG-mFGF-21在停药后控制血糖的能力也高于mFGF-21．综上所述可知,mFGF-21的PEG修饰在不影响其体外生物活性的前提下,能够提高mFGF-21的物理稳定性和抵抗蛋白酶水解的能力、降低免疫原性、增加体内稳定性、延长mFGF-21在动物体内降血糖作用的效果和时间．本实验为FGF-21化学修饰提供了重要的技术平台,对以后FGF-21的临床应用具有非常重要的意义．     

The emerging role of fibroblast growth factor 21 in diabetic nephropathy

Diabetic nephropathy (DN), an important cause of end-stage renal diseases, brings about great social and economic burden. Due to the variable pathological changes and clinical course, the prognosis of DN is very difficult to predict. DN is also usually associated with enhanced genomic damage and cellular injury. Fibroblast growth factor 21 (FGF21), a nutritionally regulated hormone secreted mainly by the liver, plays a critical role in metabolism. Administration of FGF21 decreases blood glucose, triglyceride, and cholesterol levels, and improves insulin sensitivity, which is closely associated with the development and progression of glomerular diseases. In addition, FGF21 level was associated with renal function. However, the precise role of FGF21 in DN remains unclear. This review will give a comprehensive understanding of the underlying role of FGF21 and its possible interaction with other molecules in DN.     

Fibroblast growth factor 21 alleviates acute pancreatitis via activation of the Sirt1‐autophagy signalling pathway

Fibroblast growth factor 21 (FGF21), a metabolic hormone with pleiotropic effects on glucose and lipid metabolism and insulin sensitivity, alleviates the process of acute pancreatitis (AP). However, its mechanism remains elusive. The pathological and physiological characteristics of FGF21 are observed in both patients with AP and cerulein‐induced AP models, and the mechanisms of FGF21 in response to AP are investigated by evaluating the impact of autophagy in FGF21‐treated mice and cultured pancreatic cells. Circulating levels of FGF21 significantly increase in both AP patients and cerulein‐induced AP mice, which is accompanied by the change of pathology in pancreatic injury. Replenishment of FGF21 distinctly reverses cerulein‐induced pancreatic injury and improves cerulein‐induced autophagy damage in vivo and in vitro. Mechanically, FGF21 acts on pancreatic acinar cells to up‐regulate Sirtuin‐1 (Sirt1) expression, which in turn repairs impaired autophagy and removes damaged organs. In addition, blockage of Sirt1 accelerates cerulein‐induced pancreatic injury and weakens the regulative effect in FGF21‐activated autophagy in mice. These results showed that FGF21 protects against cerulein‐induced AP by activation of Sirtuin‐1‐autophagy axis.     

Fibroblast Growth Factor 21 Improves Insulin Sensitivity and Synergizes with Insulin in Human Adipose Stem Cell-Derived (hASC) Adipocytes

Fibroblast growth factor 21 (FGF21) has evolved as a major metabolic regulator, the pharmacological administration of which causes weight loss, insulin sensitivity and glucose control in rodents and humans. To understand the molecular mechanisms by which FGF21 exerts its metabolic effects, we developed a human in vitro model of adipocytes to examine crosstalk between FGF21 and insulin signaling. Human adipose stem cell-derived (hASC) adipocytes were acutely treated with FGF21 alone, insulin alone, or in combination. Insulin signaling under these conditions was assessed by measuring tyrosine phosphorylation of insulin receptor (InsR), insulin receptor substrate-1 (IRS-1), and serine 473 phosphorylation of Akt, followed by a functional assay using 14C-2-deoxyglucose [¹⁴C]-2DG to measure glucose uptake in these cells. FGF21 alone caused a modest increase of glucose uptake, but treatment with FGF21 in combination with insulin had a synergistic effect on glucose uptake in these cells. The presence of FGF21 also effectively lowered the insulin concentration required to achieve the same level of glucose uptake compared to the absence of FGF21 by 10-fold. This acute effect of FGF21 on insulin signaling was not due to IR, IGF-1R, or IRS-1 activation. Moreover, we observed a substantial increase in basal S473-Akt phosphorylation by FGF21 alone, in contrast to the minimal shift in basal glucose uptake. Taken together, our data demonstrate that acute co-treatment of hASC-adipocytes with FGF21 and insulin can result in a synergistic improvement in glucose uptake. These effects were shown to occur at or downstream of Akt, or separate from the canonical insulin signaling pathway.     

FGF21类似物治疗动脉粥样硬化机制研究进展

动脉粥样硬化是冠心病、脑梗死、外周血管病的主要诱因,近年来发病率越来越高,严重威胁着人类生命健康。脂质代谢障碍是动脉粥样硬化的病理基础。成纤维细胞生长因子21(FGF21)是FGF家族的一种内分泌因子,它能够增加葡萄糖的摄取,调节脂质代谢,并使代谢活跃的器官（如肝脏和脂肪组织）中胰岛素反应敏感。FGF21水平与动脉粥样硬化的发生率和严重程度密切相关。然而,FGF21原型在血浆的半衰期短、体外易聚集,严重限制了其临床应用。近年来,对FGF21类似物的研究取得了突破性进展。综述了FGF21的生理作用,并讨论了基于FGF21类似物治疗动脉粥样硬化的主要突破和局限性,为FGF21蛋白类新药的开发提供了理论依据。     

Fibroblast Growth Factor Receptor 4 (FGFR4) Deficiency Improves Insulin Resistance and Glucose Metabolism under Diet-induced Obesity Conditions

The role of fibroblast growth factor receptor 4 (FGFR4) in regulating bile acid synthesis has been well defined; however, its reported role on glucose and energy metabolism remains unresolved. Here, we show that FGFR4 deficiency in mice leads to improvement in glucose metabolism, insulin sensitivity, and reduction in body weight under high fat conditions. Mechanism of action studies in FGFR4-deficient mice suggest that the effects are mediated in part by increased plasma levels of adiponectin and the endocrine FGF factors FGF21 and FGF15, the latter of which increase in response to an elevated bile acid pool. Direct actions of increased bile acids on bile acid receptors, and other potential indirect mechanisms, may also contribute to the observed metabolic changes. The results described herein suggest that FGFR4 antagonists alone, or in combination with other agents, could serve as a novel treatment for diabetes.