A stable cell-line was established that expressed the recombinant avian antibody (rAb) against the infectious bursal disease virus (IBDV). rAb exhibited neutralization activity to IBDV-B87 strain in DF1 cells. The minimum rAb concentration required for inhibition of the cytopathic effect (CPE) was 1.563 μg/mL. To test the efficacy of rAb, a 168-h cohabitation challenge experiment was performed to transmit the disease from the chickens challenged with vvIBDV (HLJ0504 strain) to three test groups of chickens, i.e. (1) chickens treated with rAb, (2) chickens treated with yolk antibody, and (3) non-treatment chickens. The survival rates of chickens treated with rAb, yolk antibody and without treatment were 73%, 67% and 20%, respectively. Another batch of chickens was challenged with IBDV (BC6/85 strain) and then injected with rAb (1.0 mg/kg) 6, 24 and 36 h post-challenge. Non-treatment chickens had 100% morbidity, whereas those administered with rAb exhibited only 20% morbidity. Morbidity was evaluated using clinical indicators and bursal histopathological section. This study provides a new approach to treating IBDV and the rAb represents a promising candidate for this IBDV therapy.

Acute lung injury (ALI) is still a leading cause of morbidity and mortality in critically ill patients. Recently, our study found that a bispecific fusion protein treatment can ameliorate the lung injury induced by LPS. However, the molecular mechanisms which bispecific fusion protein ameliorates acute lung injury remain unclear. In this study, we found that the bispecific fusion protein treatment inhibited the nuclear transcription of NF-κB in confocal laser scanning fluorescence microscopy, the bispecific fusion protein exert protective effects in the cell model of ALI induced by lipopolysaccharide (LPS) via inhibiting the nuclear factor κB (NF-κB) signaling pathway and mediate inflammation. Moreover, the treatment of the bispecific fusion protein show its efficacy in animal models stimulated by LPS, the results of real-time PCR and ELISA demonstrate that bispecific fusion protein treatment effectively inhibited the over-expression of inflammatory cytokines(tumor necrosis factor α, interleukin 1β and interleukin 17). In addition, LPS-challenged mice exhibited significant lung injury characterized by the deterioration of histopathology, which was meliorated by bispecific fusion protein treatment. Collectively, these results demonstrate that bispecific fusion protein treatment ameliorates LPS-induced ALI through reducing inflammatory cytokines and lung inflammation, which may be associated with the decreased the nuclear transcription of NF-κB. The bispecific fusion protein may be useful as a novel therapy to treat ALI.

目的 研究成纤维细胞生长因子-21(fibroblast growth factor-21,FGF-21)抑制脂多糖(LPS)诱导的急性炎症的作用及机制.方法 构建LPS诱导的小鼠急性炎症模型,FGF-21高、中、低剂量进行处理后,HE染色法观察肺部组织病理学变化,ELISA法检测血清中肿瘤坏死因子(TNF)-α、白细胞介素(IL)-1β、IL-6、IL-17含量,实时荧光定量聚合酶链反应(PCR)法检测TNF-α、IL-1β、IL-6、IL-17表达量,激光共聚焦和Western blot法检测腹腔巨噬细胞核因子(NF)-κB蛋白向细胞核内转移情况.结果 FGF-21干预后,模型小鼠肺部损伤明显减轻,炎性浸润细胞减少.血清和腹腔巨噬细胞中TNF-α、IL-1β、IL-6、IL-17含量均显著降低且成剂量依赖性趋势.激光共聚焦和Western-blot结果均显示,FGF-21能够抑制NF-κB向细胞核内转移.结论 FGF-21能够作用于巨噬细胞调控机体免疫系统,通过NF-κB信号通路缓解小鼠炎症反应状态可能是FGF-21调节免疫系统的机制之一.

Previous studies reveal that fibroblast growth factor 21 (FGF21) sensitizes insulin to achieve a synergy in regulating glucose metabolism. Here, we report that insulin sensitizes FGF21 in regulating both glucose and lipid metabolisms. db/db diabetic mice were subcutaneously administrated once a day for 6 weeks. Effective dose of insulin (1 U) could control blood glucose level of the db/db mice for maximum of 2 h, increased the body weight of the db/db mice and did not improve serum lipid parameters. In contrast, effective dose of FGF21 (0.5 mg/kg) could maintain blood glucose of the db/db mice at normal level for at least 24 h, repressed the weight gain of the mice and significantly improved lipid parameters. Ineffective doses of FGF21 (0.125 mg/kg) and insulin had no effect on blood glucose level of the db/db mice after 24 h administration, body weight or lipid parameters. However, combination of the two ineffective doses could maintain blood glucose level of the db/db mice for at least 24 h, suppressed weight gain and significantly improved lipid parameters. These results suggest that insulin sensitizes FGF21 in regulating both glucose and lipid metabolism. The results aimed to study the molecular basis of FGF21 sensitization indicates that combination of the two ineffective doses increased the mRNA expression of glut1, glut4, β-Klotho, sirt1, pgc-1α, ucp-1 and AKT phosphorylation, decreased fasn. The results demonstrate that insulin sensitizes FGF21 through elevating the phosphorylation of common gene Akt and amplifying FGF21 downstream signaling, including increasing expression of glut1 sirt1, pgc-1α, ucp-1, and decreasing fasn expression. In summary, we reports herein for the first time that insulin sensitizes FGF21 to achieve a synergy in regulating glucose and lipid metabolism. Along with previous studies, we conclude that the synergistic effect between FGF21 and insulin is realized through mutual sensitization.

将小鼠随机分为4组,第1组为正常组,第2-4组为D-半乳糖(D-gal)模型组.每天用低剂量(1mg·kg-1)和高剂量(5 mg·kg-1)FGF-21分别对3、4组模型小鼠进行治疗.7周后,检测小鼠肝脏中ROS、MDA含量,确定小鼠氧化应激水平.检测肝脏细胞核内Nrf2含量及其下游抗氧化酶SOD、CAT、GSH-Px、T-AOC活性,利用Real-time PCR检测Nrf2下游抗氧化基因转录量变化.肝脏进行病理学切片,观察不同组小鼠肝脏凋亡细胞数量变化.检测PI3K、Akt含量,并对PI3K/Akt通路调控的下游抗凋亡蛋白Bcl-2以及促凋亡蛋白Bax、Caspase-3表达量进行检测.结果表明:与模型组相比,FGF-21治疗组小鼠肝脏ROS、MDA含量均下降;Nrf2含量上升,其下游抗氧化酶活性上升,抗氧化基因转录量增加;PI3K、Akt含量下降,其下游Bcl-2蛋白表达量增加,Bax、Caspase-3表达量下降.从分子水平揭示FGF-21对小鼠肝脏的保护机制,为脂肪肝或其他肝病的治疗提供参考.

FGF21 is recently discovered with pleiotropic effects on glucose and lipid metabolism. However, the potential protective effect of FGF21 against D-gal-induced injury in the liver has not been demonstrated. The aim of this study is to investigate the pathophysiological role of FGF21 on hepatic oxidative injury and apoptosis in mice induced by D-gal. The 3-month-old Kunming mice were subcutaneously injected with D-gal (180 mg kg(-1) d(-1)) for 8 weeks and administered simultaneously with FGF21 (5 or 1 mg kg(-1) d(-1)). Our results showed that the administration of FGF21 significantly alleviated histological lesion including structure damage, degeneration, and necrosis of hepatocytes induced by D-gal, and attenuated the elevation of liver injury markers, serum AST, and ALP in a dose-dependent manner. FGF21 treatment also suppressed D-gal-induced profound elevation of ROS production and oxidative stress, as evidenced by an increase of the MDA level and depletion of the intracellular GSH level in the liver, and restored the activities of antioxidant enzymes SOD, CAT, GSH-Px, and T-AOC. Moreover, FGF21 treatment increased the nuclear abundance of Nrf2 and subsequent up regulation of several antioxidant genes. Furthermore, a TUNEL assay showed that D-gal-induced apoptosis in the mouse liver was significantly inhibited by FGF21. The expression of caspase-3 was markedly inhibited by the treatment of FGF21 in the liver of D-gal-treated mice. The levels of PI3K and PBK/Akt were also largely enhanced, which in turn inactivated pro-apoptotic signaling events, restoring the balance between pro- and anti-apoptotic Bcl-2 and Bax proteins in the liver of D-gal-treated mice. In conclusion, these results suggest that FGF21 protects the mouse liver against D-gal-induced hepatocyte oxidative stress via enhancing Nrf2-mediated antioxidant capacity and apoptosis via activating PI3K/Akt pathway.

Fibroblast growth factor 21 (FGF-21) is a secreted protein, which has anti-diabetic and lipocaic effects, but its ability to protect against hepatic fibrosis has not been studied. In this study, we investigated the ability of FGF-21 to attenuate dimethylnitrosamine (DMN)-induced hepatic fibrogenesis in mice and the mechanism of its action. Hepatic fibrosis was induced by injection of DMN, FGF-21 was administered to the mice once daily in association with DMN injection till the end of the experiment. Histopathological examination, tissue 4-hydroxyproline content and expressions of smooth muscle α-actin (α-SMA) and collagen I were measured to assess hepatic fibrosis. Ethanol/PDGF-BB-activated hepatic stellate cells (HSCs) were used to understand the mechanisms of FGF-21 inhibited hepatic fibrogenesis. Results showed that FGF-21 treatment attenuated hepatic fibrogenesis and was associated with a significant decrease in intrahepatic fibrogenesis, 4-hydroxyproline accumulation, α-SMA expression and collagen I deposition. FGF-21 treatment inhibited the activation of HSCs via down-regulating the expression of TGF-β, NF-κB nuclear translocation, phosphorylation levels of smad2/3 and IκBα. Besides, FGF-21 treatment caused activated HSC apoptosis with increasing expression of Caspase-3, and decreased the ratio of Bcl-2 to Bax. In conclusion, FGF-21 attenuates hepatic fibrogenesis and inhibits the activation of HSC warranting the use of FGF-21 as a potential therapeutic agent in the treatment of hepatic fibrosis.

Fibroblast growth factor 21 (FGF-21) is a major paracrine and endocrine regulator of metabolic homeostasis. Here we demonstrate that FGF-21 is also a potent mediator of innate immunity. Double-staining flow cytometry identified neutrophils and monocytes as the main sources of FGF-21 among circulating leukocytes. Functional assays showed that FGF-21 stimulates phagocytosis and production of reactive oxygen species in neutrophil-like HL-60 cells and monocytic THP-1 cells. The mechanism of action of FGF-21 was observed to involve FGF receptor activation, signal transduction through the PI3K/Akt pathway, and stimulation of NADPH oxidase activity. This study indicates that FGF-21 could be an attractive target for the management of inflammatory disorders.

The clearance of host cell DNA is a critical indicator for Vero-cell culture-derived rabies vaccine. In this study, we evaluated the clearance of DNA in Vero-cell culture-derived rabies vaccine by purification process utilizing ultrafiltration, nuclease digestion, and gel filtration chromatography. The results showed that the bioprocess of using nuclease decreased residual DNA. Dot-blot hybridization analysis showed that the residual host cell DNA was <100 pg/ml in the final product. The residual nuclease in rabies vaccine was less than 0.1 ng/ml protein. The residual nuclease could not paly the biologically active role of digestion of DNA. Experiments of stability showed that the freeze-drying rabies virus vaccine was stable and titers were >5.0 IU/ml. Immunogenicity test and protection experiments indicated mice were greatly induced generation of neutralizing antibodies and invoked protective effects immunized with intraperitoneal injections of the rabies vaccine. These results demonstrated that the residual DNA was removed from virus particles and nuclease was removed by gel filtration chromatography. The date indicated that technology was an efficient method to produce rabies vaccine for human use by using nuclease.