Expression of recombinant h-FGF21 in periplasmic space of Escherichia coli / 药学学报

Fibroblast growth factor 21 (FGF21) is a novel metabolic regulator of glucose and lipid, which is safe, effective and independent on insulin. FGF21 is considered as a prospective anti-diabetic drug. The aim of this study was to express recombinant h-FGF21 in periplasmic space of Escherichia coli. The pET27b plasmid was used to create the expression vectors of h-FGF21 with a PelB secretion signal. The ph-FGF21 (periplasmic expression of h-FGF21) was successfully expressed in the periplasm of E. coli BL21 (DE3), and soluble ph-FGF21 was isolated by disruption of the outer membrane. After twice of ion exchange chromatography, the purity of ph-FGF21 was above 95% in an analysis with a gray analysis software. The molecular weight of ph-FGF21 was about 20 kDa in SDS-PAGE and Western blotting analysis. The activity of ph-FGF21 and ih-FGF21 (intracellular expression of h-FGF21) was observed in vitro in the glucose uptake assay in HepG2 cells. The activity was observed in type 2 diabetic db/db mice after short or long-term treatments. The results suggest that the ph-FGF21 has a consistent activity with ih-FGF21 in vitro and in vivo.

Mechanisms of the role of fibroblast growth factor 21 in attenuating insulin resistance / 药学学报

This study is to evaluate the therapeutic effect of fibroblast growth factor 21 (FGF21) on type 2 diabetic mice model and to provide mechanistic insights into its therapeutic effect. Type 2 diabetic animal model was established with high calorie fat diet and low dose streptozotocin (STZ) injection. Mice were then randomized into 5 groups: model control, FGF21 0.25 and 0.05 μmol x kg(-1) x d(-1) groups, insulin treatment group. Ten age-matched normal KM mouse administered with saline were used as normal controls. Serum glucose, insulin, lipid products and the change of serum and liver tissue inflammation factor levels between five groups of mouse were determined. The results showed that blood glucose, insulin, free fatty acids (FFAs), triglycerides, and inflammatory factor average FGF-21 of type 2 diabetes model group and normal control group were significantly higher (P < 0.01), while compared with insulin group, no difference was significant. Average blood glucose, insulin, blood lipid and inflammatory factor of FGF-21 treatment group compared with type 2 diabetes group was significantly lower (P < 0.01) and insulin group has no difference with the model control group. The results of OGTT and HOMA-IR showed that insulin resistance state was significantly relieved in a dose-dependent manner. Thus, this study demonstrates that FGF-21 significantly remits type 2 diabetic mice model's insulin resistance state and participates in the regulation of inflammatory factor levels and type 2 diabetes metabolic disorders.

Antitumor efficacy of the recombinant Newcastle disease virus rNDV-IL15 on melanoma models / 药学学报

In order to enhance the antitumor efficacy of recombinant Newcastle disease virus, rNDV-IL15 was rescued in this study. Recombinant plasmid prNDV-IL15 was constructed, and BHK21 cells were transfected with the recombinant plasmid. Finally, the recombinant Newcastle disease virus rNDV-IL15 was successfully rescued. The growth curves of these two recombinant viruses were determined. Murine melanoma B16F10 cells were infected with rNDV-IL15 at MOI of 0.1, and the expression level of IL15 in the supernatant was detected by ELISA. The antitumor efficacy of rNDV-IL15 and rNDV was compared in vitro and in vivo. Results showed that prNDV-IL15 was constructed and recombinant virus rNDV-IL15 was successfully rescued. The growth curve of rNDV-IL15 showed that the growth of rNDV-IL15 had not been changed after insertion of IL15 gene. Results showed that there was high level of IL15 expression in the supernatant of rNDV-IL5-infected B16F10 cells (1 044.3 +/- 27.7 ng x mL(-1)). rNDV-IL15 and rNDV significantly inhibited the growth of B16F10 cells in vitro in a time-dependent manner. However, there was no significant difference between them. In animal experiments, rNDV-IL15 efficiently suppressed tumor growth in vivo when compared with rNDV, and the difference was statistically significant. The results suggested that rNDV-IL15 is a more effective antitumor agent.

Therapeutic efficacy of three bispecific antibodies on rheumatoid arthritis mice models / 药学学报

In order to obtain the lead compound for treatment of rheumatoid arthritis (RA), in this study, therapeutic efficacy of three bispecific antibodies (BsAB-1, BsAB-2 and BsAB-3) against both hIL-1beta and hIL-17 were compared on CIA model mice. First, by ELISA method we compared the binding capacity of the three bispecific antibodies to the two antigens. The results showed that all three antibodies could simultaneously bind both antigens, among these antibodies, BsAB-1 was superior over BsAB-2 and BsAB-3. CIA model was established with chicken type II collagen (CII) and developed RA-like symptoms such as ankle swelling, skin tight, hind foot skin hyperemia. The CIA mice were treated with three antibodies once every two days for total of 29 days. Compared with the CIA model mice, the RA-like symptoms of the antibody treated-mice significantly relieved, while the BsAB-1 treated-mice were almost recovered. CII antibody level in the serum and cytokines (IL-2, IL-1beta, IL-17A and TNF-alpha) expression in the spleen were examined. Compared with the CIA model mice, all three antibodies could significantly reduce CII antibody and cytokine expression levels. BsAB-1 antibody was more potent than BsAB-2 and BsAB-3. In summary, BsAB-1 is superior over BsAB-2 and BsAB-3 in amelioration of RA symptoms and regulation of CII antibody production and pro-inflammatory cytokine expression, therefore, BsAB-1 can be chosen as a lead compound for further development of drug candidate for treatment of RA.

FGF-21 protects H9c2 cardiomyoblasts against hydrogen peroxide-induced oxidative stress injury / 药学学报

Fibroblast growth factor-21 (FGF-21) is an important metabolism regulator, however, whether FGF-21 has effects on cardiovascular remains unclear. In this study, H2O2-induced injury in H9c2 cells was used as a cell model, the anti-apoptosis potential and mechanism of FGF-21 against oxidative injury were evaluated by MTT assay, flow cytometry assay and real-time PCR. The results showed that FGF-21 could increase the cell survival of H2O2-induced injury in H9c2 cells and prevent H9c2 cells from oxidative stress-induced apoptosis. Furthermore, FGF-21 can elevate SOD activity and regulate Bcl-2/Bax expression in H9c2 cells. The results suggest that FGF-21 have protective effect against the H2O2-induced apoptosis in H9c2 cells.

The synergistic effect of FGF-21 and insulin on regulating glucose metabolism and its mechanism / 药学学报

Previous studies proposed that the synergistic effect of fibroblast growth factor-21 (FGF-21) and insulin may be due to the improvement of insulin sensitivity by FGF-21. However, there is no experimental evidence to support this. This study was designed to elucidate the mechanism of synergistic effect of FGF-21 and insulin in the regulation of glucose metabolism. The synergistic effect of FGF-21 and insulin on regulating glucose metabolism was demonstrated by investigating the glucose absorption rate by insulin resistance HepG2 cell model and the blood glucose chances in type 2 diabetic db/db mice after treatments with different concentrations of FGF-21 or/and insulin; The synergistic metabolism was revealed through detecting GLUT1 and GLUT4 transcription levels in the liver by real-time PCR method. The experimental results showed that FGF-21 and insulin have a synergistic effect on the regulation of glucose metabolism. The results of real-time PCR showed that the effective dose of FGF-21 could up-regulate the transcription level of GLUT1 in a dose-dependent manner, but had no effect on the transcription level of GLUT4. Insulin (4 u) alone could up-regulate the transcription level of GLUT4, yet had no effect on that of GLUT1. Ineffective dose 0.1 mg kg(-1) FGF-21 alone could not change the transcription level of GLUT1 or GLUT4. However, when the ineffective dose 0.1 mg x kg(-1) FGF-21 was used in combination with insulin (4 u) significantly increased the transcription levels of both GLUT1 and GLUT4, the transcription level of GLUT1 was similar to that treated with 5 time concentration of FGF-21 alone; the transcription level of GLUT4 is higher than that treated with insulin (4 u) alone. In summary, in the presence of FGF-21, insulin increases the sensitivity of FGF-21 through enhancing GLUT1 transcription. Vice versa, FGF-21 increases the sensitivity of insulin by stimulating GLUT4 transcription in the presence of insulin. FGF-21 and insulin exert a synergistic effect on glucose metabolism through mutual sensitization.

The synergism and mechanism of action of rClone30-hDR5 in combination with TRAIL on HCC / 药学学报

To investigate the cell-killing effect and its possible mechanism of rClone30-hDR5 in combination with TRAIL on human hepatic carcinoma (HCC) cell line, first of all, recombinant plasmid pee12.4-hDR5 was introduced into HepG2 cells by liposome transfection. After five rounds of screening by flow cytometry, HepG2 cells expressing high levels of DR5 on cell surface were isolated. The cytotoxicity of TRAIL to selected cells was higher than that of TRAIL to HepG2 cells by MTT method (P < 0.01). The result suggested that the cloned hDR5 gene had biological activity. MTT assay showed that, rClone30- hDR5 in combination with TRAIL more efficiently inhibited the tumor growth of HepG2 cells compared to rClone30-hDR5 or TRAIL in vitro. The results of Annexin V-FITC/PI staining and Quantitative Real-time PCR indicated that rClone30-hDR5 in combination with TRAIL significantly increased the mRNA levels of caspase 3 and caspase 8, and induced the apoptosis of tumor cells. HepG2 cells were infected with rClone30-hDR5 or rClone30 at MOI of 1. The expression of hDR5 on tumor surface increased significantly by rClone30-hDR5 compared to that by rClone30, which contributed to the sensitivity to TRAIL. In conclusion, rClone30-hDR5 in combination with TRAIL has potential application value in cancer treatment.

Effect of FGF-21 on learning and memory ability and antioxidant capacity in brain tissue of D-galactose-induced aging mice / 药学学报

This study aims to investigate the effects of fibroblast growth factor 21 (FGF-21) on learning and memory abilities and antioxidant capacity of D-galactose-induced aging mice. Kunming mice (37.1 +/- 0.62) g were randomly divided into normal control group, model group and FGF-21 high, medium and low dose groups (n = 8). Each group was injected in cervical part subcutaneously with D-galactose 180 mg x kg(-1) x d(-1) once a day for 8 weeks. At the same time, FGF-21-treated mice were administered with FGF-21 by giving subcutaneous injection in cervical part at the daily doses of 5, 2 and 1 mg x kg(-1) x d(-1). The normal control group was given with normal saline by subcutaneous injection in cervical part. At seventh week of the experiment, the learning and memory abilities of mice were determined by water maze and jumping stand tests. At the end of the experiment, the mice were sacrificed and the cells damage of hippocampus was observed by HE staining in each group. Reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) and total antioxidant capacity (T-AOC) in the brain of mice were determined. The results showed that different doses of FGF-21 could reduce the time reaching the end (P < 0.01 or P < 0.05) and the number of touching blind side (P < 0.01 or P < 0.05) in the water maze comparing with the model group. It could also prolong the latency time (P < 0.05) and decrease the number of errors (P < 0.01 or P < 0.05) in the step down test. The result of HE staining showed that FGF-21 could significantly reduce brain cell damage in the hippocampus. The ROS and MDA levels of three different doses FGF-21 treatment group reduced significantly than that of the model group [(5.58 +/- 1.07), (7.78 +/- 1.92), (9.03 +/- 1.77) vs (12.75 +/- 2.02) pmol (DCF) x min(-1) x mg(-1), P < 0.01 or P < 0.05], [(2.92 +/- 0.71), (4.21 +/- 0.81), (4.41 +/- 0.97) vs (5.62 +/- 0.63) nmol x mg(-1) (protein), P < 0.01]. Comparing with the model group, the activities of SOD, GPx, CAT and T-AOC of the three different doses FGF-21 treatment groups were also improved in a dose-dependent manner. This study demonstrates that FGF-21 can ameliorate learning and memory abilities of D-galactose induced aging mice, improve the antioxidant abilities in brain tissue and delay brain aging. This finding provides a theoretical support for clinical application of FGF-21 as a novel therapeutics for preventing aging.

Antitumor activity of the recombinant rClone30-CD/5-FC system / 药学学报

5-Flucytosine (5-FC) could be changed to 5-fluorouracil (5-FU) by cytosine deaminase (CD), the latter is able to kill cancer cells. However, there is no efficient method to deliver the CD gene into the tumor cells, which hampers the application of the suicide gene system. In this experiment, for the first time, the NDV has been utilized as a vector to deliver the CD gene into the cancer cells, the virus can infect the cancer cells specifically, replicate and assemble, while the cytosine deaminase is expressed. Then the CD converts the prodrug 5-FC into 5-FU to achieve the purpose of inhibiting tumor. Firstly, the whole genome of E. coli JM109 was extracted, and the CD gene was obtained by cloning method. Then the CD and IRES-EGFP were ligated into the pEE12.4 expression vector to become a recombinant pEE12.4IE-CD eukaryotic expression plasmid. The human liver cancer cells were transfected with the plasmid. The cells were treated with different concentrations of 5-FC, MTT method was used to determine the killing effect of CD/5-FC system on the human liver cancer cells. The cell deaths were 18.07%, 42.98% and 62.20% respectively when the concentrations of prodrug were at 10, 20 and 30 mmol x L(-1). In 5-FC acute toxicity experiment, Kunming mice were injected with different concentrations of 5-FC at intervals of 1:0.5. The LD50 of 5-FC through iv injection was determined by improved Karber's method, the LD50 was 507 mg x kg(-1) and the 95% confidence limit was 374-695 mg x kg(-1). According to the maximum LD0 dose of the LD50, the maximum safe dose was 200 mg x kg(-1). Body weight and clinic symptoms of the experimental animals were observed. These results laid the foundation to verify the antitumor effect and safety of CD/5-FC system in animal models. The CD gene was ligated into the NDV (rClone30) carrier, then the tumor-bearing animal was established to perform the tumor inhibiting experiment. The result showed that the recombinant rClone30-CD/5-FC system has a high antitumor activity in vivo. To summarize, CD gene has been cloned and its bioactivity has been confirmed in the mammalian cells. It is the first time in this study to utilize the recombinant NDV to deliver the CD gene into the tumor cells; our result proves the rClone30-CD/5-FC system is a potential method for cancer therapy.

The long lasting effect of the murine fibroblast growth factor-21 on blood glucose control of diabetic animals / 药学学报

Insulin is the most common medicine used for diabetic patients, unfortunately, its effective time is short, even the long-acting insulin cannot obtain a satisfactory effect. Fibroblast growth factor (FGF)-21 is a recently discovered glucose mediator and expected to be a potential anti-diabetic drug that does not rely on insulin. In this study, db/db mice were used as the type 2 diabetic model to examine whether mFGF-21 has the long-term blood lowering effect on the animal model. The results showed that mFGF-21 could stably maintain the blood glucose at normal level for a long-term in a dose-dependent manner. Administration of mFGF-21 once a day with three doses (0.125, 0.25 and 0.5 mg x kg(-1)) could maintain blood glucose of the model animals at normal level for at least 24 h. Administration of mFGF-21 every two days with the same doses could maintain blood glucose of the model animals at normal level for at least 48 h, although it took longer time for blood glucose to reach to normal level depending on doses used (twenty injections for 0.125 mg x kg(-1) and 0.25 mg x kg(-1) doses, ten injections for 0.5 mg x kg(-1) dose). Surprisingly, the blood glucose of the treated model animals still maintained at normal level for 24 h after the experiment terminated. Glycosylated hemoglobin level of the animals treated with mFGF-21, which represented long-term glucose status, decreased significantly compared to the control group and the insulin group. The results suggest that FGF-21 has potential to become a long-acting and potent anti-diabetic drug.

Therapeutic effect of fibroblast growth factor 21 on hypertension induced by insulin resistance / 药学学报

This study is to evaluate the therapeutic effect of fibroblast growth factor 21 (FGF21) on hypertension induced by insulin resistance in rats and to provide mechanistic insights into its therapeutic effect. Male Sprague-Dawley (SD) rats were fed with high-fructose (10%) water to develop mild hypertensive models within 4 weeks, then randomized into 4 groups: model control, FGF21 0.25, 0.1 and 0.05 micromol x kg(-1) x d(-1) groups. Five age-matched normal SD rats administrated with saline were used as normal controls. The rats in each group were treated once a day for 4 weeks. Body weight was measured weekly, systolic blood pressure (SBP) was measured noninvasively using a tail-cuff method, insulin sensitivity was assessed using oral glucose tolerance test (OGTT) and HOMA-IR assay. At the end of the treatment, blood samples were collected, and blood glucose, serum cholesterol, serum triglyceride and serum insulin were measured. The results showed that blood pressure of the rats treated with different doses of FGF21 returned to normal levels [(122.2 +/- 3.5) mmHg, P < 0.01] after 4-week treatment, whereas, SBP of untreated (model control) rats maintained a high level [(142.5 +/- 4.5) mmHg] throughout the treatment. The observation of blood pressure in 24 h revealed that SBP of FGF21 treated-rats maintained at (130 +/- 4.5) mmHg vs. (143 +/- 5.5) mmHg for model control (P < 0.01). FGF21 treatment groups improved serum lipids obviously, total cholesterol (TC) and triglyceride (TG) levels decreased significantly to normal levels. The serum NO levels of three different doses FGF21 treatment group were significantly higher than that of the model control group [(7.32 +/- 0.11), (7.24 +/- 0.13), (6.94 +/- 0.08) vs. (6.56 +/- 0.19) micromol x L(-1), P < 0.01], and the degree of improvement showed obvious dose-dependent manner, indicating that FGF21 can significant increase serum NO in fructose-induced hypertension rat model and improve endothelial NO release function. The results of OGTT and HOMA-IR showed that insulin resistance state was significantly relieved in a dose-dependent manner. Thus, this study demonstrates that FGF21 significantly ameliorates blood pressure in fructose-induced hypertension model by relieving insulin resistance. This finding provides a theoretical support for clinical application of FGF21 as a novel therapeutics for treatment of essential hypertension.

Therapeutic effect of fibroblast growth factor 21 on NAFLD in MSG-iR mice and its mechanism / 药学学报

This study is to evaluate the therapeutic effect of fibroblast growth factor 21 (FGF21) on NAFLD in MSG-IR mice and to provide mechanism insights into its therapeutic effect. The MSG-IR mice with insulin resistance were treated with high dose (0.1 micromol.kg-1d-1) and low dose (0.025 micromol.kg-1d-1) of FGF21 once a day for 5 weeks. Body weight was measured weekly. At the end of the experiment, serum lipids, insulin and aminotransferases were measured. Hepatic steatosis was observed. The expression of key genes regulating energy metabolism were detected by real-time PCR. The results showed that after 5 weeks treatment, both doses of FGF21 reduced body weight (P<0.01), corrected dyslipidemia (P<0.01), reversed steatosis and restored the liver morphology in the MSG model mice and significantly ameliorated insulin resistance. Additionally, real-time PCR showed that FGF21 significantly reduced transcription levels of fat synthetic genes, decreased fat synthesis and promoted lipolysis and energy metabolism by up-regulating key genes of lipolysis, thereby liver fat accumulation was reduced and liver function was restored to normal levels. In conclusion, FGF21 significantly reduces body weight of the MSG-IR mice, ameliorates insulin resistance, reverses hepatic steatosis. These findings provide a theoretical support for clinical application of FGF21 as a novel therapeutics for treatment of NAFLD.

Optimization and characterization of a novel FGF21 mutant / 药学学报

Fibroblast growth factor 21 (FGF21) is a member of FGF family. It has been demonstrated that FGF21 is an independent, safe and effective regulator of blood glucose levels in vivo. In order to improve the activity of FGF21, we exchanged the beta10-beta12 domain of the human FGF21 with that of the mouse FGF21 to construct a novel FGF21 gene (named hmFGF21), and then subcloned hmFGF21 gene into the SUMO expression vector to create pSUMO-hmFGF21 and transformed it into E. coli Rosetta for expression of the fusion protein SUMO-hmFGF21. Both in vitro and in vivo glucose regulation activity of hmFGF21 was evaluated. The SDS-PAGE result showed that compared with wild-type hFGF21, the soluble expression of hmFGF21 increased about 2-fold. HmFGF21 was more potent in stimulation of glucose uptake in HepG2 cells in vitro. The results of anti-diabetic effect on db/db mice demonstrated that hmFGF21 had better efficacy on controlling the blood glucose of the db/db diabetic animals than wild-type hFGF21. These results suggest that the biological properties of FGF21 are significantly improved by optimization.

Establishment of a novel cell model targeted on FGF-21 receptor for screening anti-diabetic drug candidates / 药学学报

The aim of this project is to establish a fibroblast growth factor-21 (FGF-21) signaling pathway targeted cell model, for screening a class of FGF-21 receptor agonists as anti-diabetic candidates. FGF-21 requires beta klotho transmembrane proteins as co-receptor for the activation of tyrosine kinase FGF receptor (FGFR) signaling, thereby activating a series of intracellular signaling pathways and regulating gene transcription for glucose metabolism. Firstly a recombinant plasmid expressing co-receptor beta klotho and EGFP reporter genes was constructed. After introducing the recombinant plasmid into package cells, the cell culture supernatant was used to infect 3T3-L1 cells, which were then screened for stably expressing beta klotho gene. Administration of FGF-21 increased the expression of GLUT1 and stimulated GLUT1-mediated glucose uptake. This novel cell model can be conveniently used in high-throughput drug screening of FGF-21 or FGF-21 analogues.

Expression and pharmacological evaluation of fusion protein FGF21-L-Fc / 药学学报

FGF21 (fibroblast growth factor 21) is a recently described member of the FGF family. It has been previously demonstrated that FGF21 is a potent regulator of glucose homeostasis. To improve stability of FGF21 for better efficacy, a new form of recombinant FGF21 was generated by fusion of a full length FGF21 gene and the Fc fragment of human IgG4 with flexible linker sequence. To examine the glucose regulation activity of FGF21-L-Fc, 3T3-L1 pre-adipocytes were differentiated into adipocytes, and glucose uptake activity of FGF21-L-Fc was examined by glucose oxidase and peroxidase (GOD-POD) assay. The results showed that in comparison with wild type FGF21, FGF21-L-Fc was more potent in stimulation of glucose uptake by 3T3-L1. In vivo studies on the modified protein demonstrated that FGF-L-Fc had a better efficacy in lowering blood glucose of the STZ-induced diabetic animals and controlled glucose level for a longer time. The results provided a sound basis for further studies.

Efficient expression of soluble human FGF-21 and its glucose regulation activity / 药学学报

The cDNA of human FGF-21 was subcloned into the pSUMO expression vector and the fusion protein was induced to express in Escherichia coli Rosetta (DE3). The recombinant hFGF-21 was expressed in soluble form in the pSUMO expression system. The recombinant fusion protein was purified by Ni-NTA column. The purified recombinant protein was dialyzed against PBS for re-nature. To obtain pure and active recombinant protein, the fusion protein was subjected to cleavage with SUMO protease I. To examine glucose regulation activity of hFGF-21, 3T3-L1 pre-adipocytes were differentiated into adipocytes, glucose up-take activity of hFGF-21 was examined by glucose oxidase and peroxidase (GOD-POD) assay. Compared with no stimulation control, the recombinant hFGF-21 treatment led to a significant increase in glucose consumption of adipocytes and a significant decrease in concentration of glucose in the medium (P < 0.05, P < 0.001).

Correlation of human resistin gene expression with leukemia incidence / 中国实验血液学杂志

Although the effect of mouse resistin on insulin-resistance has been well defined, but the biological function of human resistin is still unknown. This study was aimed to explore the possible physiological and pathological effects of human resistin, as well as the tissue distribution of human resistin and correlation of resistin gene expression with leukemia incidence. 152 leukemia patients without inflammatory complication and 100 healthy persons were selected as experimental and control groups respectively. The blood samples were collected, the total RNA was extracted, the expression distribution of resistin in different tissues was detected by semi-quantitative RT-PCR and then the statistical analysis was carried out. The results indicated that the expression of the human resistin gene was detected in normal fetus liver, adult bone marrow and umbilical cord blood and peripheral blood cells, while the resistin gene could not be amplified in fat, umbilical cord, placenta and adult liver. The resistin expression was detected in 21% leukemia patients and 27% healthy persons. The difference of the resistin gene expression between the two groups was not statistically significant (p>0.05). It is concluded that the higher expression of resistin exists in normal human fetus liver, adult bone marrow, umbilical cord blood and peripheral blood cells, which indicates that the distribution of human resistin correlates with normal hematopoiesis in certain extent, but its expression level and rate may not correlate with the incidence of leukemia.