BACKGROUNDRetinal edema is the major complication of retinal vein occlusion and diabetic retinopathy; it can damage visual function by influencing macular region. This study was to establish a rat retinal edema model and explore the related VEGF expression and observe the responses to anti-VEGF drugs in this model.

METHODSA rat retinal edema model was established by inducing photochemical reaction using a 532 nm laser after the intravenous injection of Erythrosin B. Immediately after the laser treatment, models were given intravitreal injections of Ranibizumab or Conbercept to inhibit VEGF expression, and the changes of retinal thickness were measured. Retinal edema was observed using fundus photography (FP), optical coherence tomography (OCT), and fluoresce in fundus angiography (FFA) at 0, 1, 2, 4, 7 and 14 days after intervention. The retinal VEGF expression was measured using enzyme-linked immunosorbent assay (ELISA) and western blotting at each time point. The rat retinal edema model was also used to verify the function of anti-VEGF polypeptide ZY1.

RESULTSBoth retinal edema and vascular leakage were clearly observed at 1, 2 and 4 days after photochemical induction and the retinal thickness increased notably over the same period. The retinal VEGF expression peaked at day 1 and retina became thickening simultaneously. After the interventions, the VEGF expression of the Ranibizumab and Conbercept groups decreased at each time point compared to the edema group (26.90 ± 3.57 vs. 40.29 ± 6.68, F = 31.269 on day 1 and 22.36 ± 1.12 vs. 29.92 ± 0.93 F = 163.789 on day 2, both P < 0.01); the mean RT (278 ± 4 vs. 288 ± 3, F = 134.190 on day 1 and 274 ± 7 vs. 284 ± 6, F = 64.367 on day 2, both P < 0.05) and vascular leakage in these groups also decreased. The same results were observed in the ZY1 group, particularly at day 2 (P < 0.05).

CONCLUSIONSThis retinal edema model induced by a photochemical reaction is reliable and repeatable. Induced edema increases expression of VEGF. This model can be used to test new drugs.

Angiogenesis Inhibitors ; therapeutic use ; Animals ; Enzyme-Linked Immunosorbent Assay ; Erythrosine ; toxicity ; Fluorescein Angiography ; Intravitreal Injections ; Macular Edema ; chemically induced ; drug therapy ; metabolism ; Ranibizumab ; therapeutic use ; Rats ; Rats, Sprague-Dawley ; Recombinant Fusion Proteins ; therapeutic use ; Tomography, Optical Coherence ; Vascular Endothelial Growth Factor A ; metabolism

PURPOSE: The purpose of this study was to examine the effects of Cu/Zn SOD on reduction of hindlimb muscular atrophy induced by cisplatin in rats. METHODS: Forty-two rats were assigned to three groups; control group, Cisplatin (CDDP) group and cisplatin with Cu/Zn SOD (CDDP-SOD) group. At day 35 hindlimb muscles were dissected. Food intake, activity, withdrawal threshold, muscle weight, and Type I, II fiber cross-sectional area (CSA) of dissected muscles were measured. Relative SOD activity and expression of MHC and phosphorylated Akt, ERK were measured after dissection. RESULTS: Muscle weight and Type I, II fiber CSA of hindlimb muscles in the CDDP group were significantly less than the control group. Muscle weight and Type I, II fiber CSA of hindlimb muscles, food intake, activity, and withdrawal thresholds of the CDDP-SOD group were significantly greater than the CDDP group. There were no significant differences in relative SOD activities of hindlimb muscles between the CDDP-SOD and CDDP groups. MHC expression and phosphorylated Akt, ERK of hindlimb muscles in the CDDP-SOD group were significantly greater than the CDDP group. CONCLUSION: Cu/Zn SOD attenuates hindlimb muscular atrophy induced by cisplatin through increased food intake and activity. Increment of phosphorylated Akt, ERK may relate to attenuation of hindlimb muscular atrophy.
Animals ; Body Weight/drug effects ; Cisplatin/*toxicity ; Disease Models, Animal ; Extracellular Signal-Regulated MAP Kinases/metabolism ; Hindlimb ; Male ; Muscle, Skeletal/*drug effects/enzymology/metabolism ; Muscular Atrophy/*chemically induced/metabolism/pathology ; Phosphorylation ; Proto-Oncogene Proteins c-akt/metabolism ; Rats ; Rats, Sprague-Dawley ; Recombinant Proteins/biosynthesis/genetics/pharmacology ; Superoxide Dismutase/genetics/metabolism/pharmacology ; Superoxides/metabolism

BACKGROUNDIn addition to hematopoietic effect, the erythropoietin is known as a multifunctional cytokine with anti-fibrosis and organ-protective activities. The purpose of this study was to evaluate the effect of recombinant human erythropoietin (rhEPO) on hepatic fibrosis and hepatic stellate cells (HSCs).

METHODSCarbon tetrachloride (CCl(4)) induced hepatic fibrosis mice models were used for in vivo study and HSCs line for in vitro study. CCl(4) and rhEPO (0, 200 or 1000 U/kg) was injected intraperitoneally in BALB/c mice three times a week for 4 weeks. Immunohistochemistry and immunoblotting were performed to evaluate expressions of transforming growth factor-β1 (TGF-β1), α-smooth muscle actin (α-SMA), and fibronectin in explanted liver. Immunoblotting of α-SMA, phophorylated Smad-2 and Smad-2/3 was performed in HSCs treated with TGF-β1 and/or rhEPO.

RESULTSExpressions of TGF-β1, α-SMA, and fibronectin were increased in CCl(4) injected mice livers, but significantly attenuated by co-treatment with CCl(4) and rhEPO. Co-treatment of rhEPO markedly suppressed fibrosis in Masson's trichrome compared with treatment of only CCl(4). TGF-β1 increased phosphorylated α-SMA, Smad-2 expressions in HSCs, which were decreased by rhEPO co-treatment.

CONCLUSIONSTreatment of rhEPO effectively suppressed fibrosis in CCl(4)-induced liver fibrosis mice models. Anti-fibrosis effect of rhEPO could be related to inhibition of TGF-β1 induced activation of HSCs.

Animals ; Carbon Tetrachloride ; toxicity ; Cells, Cultured ; Erythropoietin ; pharmacology ; therapeutic use ; Fibronectins ; analysis ; Hepatic Stellate Cells ; drug effects ; Liver Cirrhosis, Experimental ; metabolism ; prevention & control ; Male ; Mice ; Mice, Inbred BALB C ; Recombinant Proteins ; pharmacology ; Smad2 Protein ; metabolism ; Transforming Growth Factor beta ; antagonists & inhibitors ; physiology

In order to increase the plasma half-life and tissue specificity of IL-1 receptor antagonist, a recombinant fusion protein IL-1Ra-HSA, linked by a rigid peptide linker PAPAP, was engineered and expressed by the Pichia pastoris host cells. The fusion protein was secreted to the host cells culture, identified by Western blot, and purified by affinity chromatography. This was followed by a further examination of its bioactivity and pharmacokinetics. Our results demonstrated that the fusion protein retained the antagonist activity of IL-1Ra, capable of binding specifically to the IL-1 receptor on human melanoma A375.S2 cells, and inhibits the cytolytic effect of IL-1beta to A375.S2 cells. Albumin fusion dramatically extended the half-life of IL-1Ra and resulted in a specific accumulation of IL-1Ra in the arthritic paws and a lower distribution of IL-1Ra in other organs such as liver, kidney, spleen and lung in mice with collagen-induced arthritis. The findings reported herein indicate that the fusion protein is likely to have greater clinical applications in areas such as the treatment of rheumatoid arthritis.
Animals ; Apoptosis ; drug effects ; Arthritis, Experimental ; metabolism ; Cell Line, Tumor ; Forelimb ; metabolism ; Half-Life ; Humans ; Interleukin 1 Receptor Antagonist Protein ; genetics ; metabolism ; pharmacokinetics ; pharmacology ; Interleukin-1beta ; toxicity ; Male ; Melanoma ; pathology ; Mice ; Mice, Inbred DBA ; Pichia ; genetics ; metabolism ; Plasmids ; Recombinant Fusion Proteins ; genetics ; metabolism ; pharmacokinetics ; pharmacology ; Serum Albumin ; genetics ; metabolism ; pharmacokinetics ; pharmacology ; Tissue Distribution

OBJECTIVEBloom's syndrome is an autosomal recessive disorder characterized by genomic instability and a predisposition to many cancers. Mutations of the BLM gene (encoding a BLM helicase) may form a structure of the etiology of this disease. As a global pollutant, mercury poses a major threat to human health. The current study was conducted to elucidate the effects of Hg(2+) on the structure and activity of BLM642-1290 recombinant helicase, and to further explore the molecular mechanisms of mercury toxicity to the DNA helicase.

METHODSThe effects of Hg(2+) on biological activity and structure of BLM642-1290 recombinant helicase were determined by fluorescence polarized, ultraviolet spectroscopic, and free-phosphorus assay technologies, respectively.

RESULTSThe helicase activity, the DNA-binding activity, and the ATPase activity of BLM642-1290 recombinant helicase were inhibited by Hg(2+) treatment. The LMCT (ligand-to-metal charge transition) peaks of the helicase were enhanced with the increase of the Hg(2+) level. The LMCT peaks of the same concentration of helicase gradually increased over time.

CONCLUSIONThe biological activity of BLM642-1290 recombinant helicase is inhibited by Hg(2+) treatment. The conformation of the helicase is significantly altered by Hg(2+). There exist two binding sites between Hg(2+) and the helicase, which are located in the amino acid residues 1063-1066 and 940-944 of the helicase, respectively.

Adenosine Triphosphatases ; metabolism ; Base Sequence ; DNA Primers ; Fluorescence Polarization ; Humans ; Mercury ; toxicity ; Protein Conformation ; RecQ Helicases ; chemistry ; drug effects ; metabolism ; Recombinant Proteins ; chemistry ; drug effects ; metabolism ; Spectrophotometry, Ultraviolet ; Structure-Activity Relationship

OBJECTIVETo assess the severity and reversibility of the chronic toxicity of a novel recombinant human granulocyte colony-stimulating factor (rhG-CSFa) in rats and the dose-effect relationship.

METHODSA total of 100 Sprague-Dawley rats (equal numbers of male and female) were randomly divided into five groups (20 rats in each group): four groups were treated with rhG-CSFa at 500, 100, 10, 1 µg/kg, respectively, and one group was treated with vehicle only to serve as the control. The rats were received subcutaneous injections of rhG-CSFa or vehicle daily for 13 weeks. During the course of the chronic toxicity study, the physical status, body weight, and food consumption were monitored. Half of the rats in each group (n = 10) were sacrificed after the last rhG-CSFa administration, and the other half were sacrificed at five weeks after the last rhG-CSFa administration. Urinalyses, blood biochemistry, hematological analysis, histopathological examination, and immunological tests were performed for each of the rats.

RESULTSThe hematological analyses revealed that the mean white blood cells count, neutrophils count, and neutrophils percentage were increased in male rats at the dose of 10 µg/kg or higher, and these were related with the biological activity of rhG-CSFa. Some small abnormalities were observed in the spleen of a few rats when used highest dose (500 µg/kg, a dosage of 200 folds higher than the normal clinical dosage), but these abnormalities were recovered within 5-week recovery period. No other rhG-CSFa-related abnormalities were observed in this chronic toxicity study.

CONCLUSIONNo significant toxicity and immunogenicity are observed with rhG-CSFa administration to rats in the chronic toxicity studies.

Animals ; Bilirubin ; urine ; Blood Chemical Analysis ; Dose-Response Relationship, Drug ; Female ; Granulocyte Colony-Stimulating Factor ; genetics ; toxicity ; Humans ; Lung ; cytology ; drug effects ; Male ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Recombinant Proteins ; Spleen ; cytology ; drug effects ; Trachea ; cytology ; drug effects

Mutations in the fused in sarcoma/translocated in liposarcoma (FUS/TLS) gene have been associated with amyotrophic lateral sclerosis (ALS). FUS-positive neuropathology is reported in a range of neurodegenerative diseases, including ALS and fronto-temporal lobar degeneration with ubiquitin-positive pathology (FTLDU). To examine protein aggregation and cytotoxicity, we expressed human FUS protein in yeast. Expression of either wild type or ALS-associated R524S or P525L mutant FUS in yeast cells led to formation of aggregates and cytotoxicity, with the two ALS mutants showing increased cytotoxicity. Therefore, yeast cells expressing human FUS protein recapitulate key features of FUS-positive neurodegenerative diseases. Interestingly, a significant fraction of FUS expressing yeast cells stained by propidium iodide were without detectable protein aggregates, suggesting that membrane impairment and cellular damage caused by FUS expression may occur before protein aggregates become microscopically detectable and that aggregate formation might protect cells from FUS-mediated cytotoxicity. The N-terminus of FUS, containing the QGSY and G rich regions, is sufficient for the formation of aggregates but not cytotoxicity. The C-terminal domain, which contains a cluster of mutations, did not show aggregation or cytotoxicity. Similar to TDP-43 when expressed in yeast, FUS protein has the intrinsic property of forming aggregates in the absence of other human proteins. On the other hand, the aggregates formed by FUS are thioflavin T-positive and resistant to 0.5% sarkosyl, unlike TDP-43 when expressed in yeast cells. Furthermore, TDP-43 and FUS display distinct domain requirements in aggregate formation and cytotoxicity.
Amino Acid Sequence ; Amino Acid Substitution ; DNA-Binding Proteins ; genetics ; metabolism ; Humans ; Mutation ; Neurodegenerative Diseases ; pathology ; Protein Structure, Tertiary ; RNA-Binding Protein FUS ; chemistry ; genetics ; metabolism ; Recombinant Proteins ; genetics ; metabolism ; toxicity ; Saccharomyces cerevisiae ; growth & development ; metabolism ; Sarcosine ; analogs & derivatives ; pharmacology ; Thiazoles ; metabolism

OBJECTIVETo provide the acute toxicity data of hygromycin B phosphotransferase (HPT) using recombinant protein purified from E. coli.

METHODSRecombinant HPT protein was expressed and purified from E. coli. To exclude the potential adverse effect of bacteria protein in recombinant HPT protein, bacterial control plasmid was constructed, and bacteria control protein was extracted and prepared as recombinant HPT protein. One hundred mice, randomly assigned to 5 groups, were administrated 10 g/kg, 5 g/kg, or 1 g/kg body weight of HPT or 5 g/kg body weight of bacterial control protein or phosphate-buffered saline (PBS) respectively by oral gavage.

RESULTSAll animals survived with no significant change in body weight gain throughout the study. Macroscopic necropsy examination on day 15 revealed no gross pathological lesions in any of the animals. The maximum tolerated dose (MTD) of HPT was 10 g/kg body weight in mice and could be regarded as nontoxic.

CONCLUSIONHPT protein does not have any safety problems to human health.

Animals ; Bacterial Proteins ; isolation & purification ; toxicity ; Escherichia coli ; genetics ; metabolism ; Female ; Male ; Mice ; Mice, Inbred Strains ; Phosphotransferases (Alcohol Group Acceptor) ; isolation & purification ; toxicity ; Recombinant Proteins ; isolation & purification ; toxicity ; Toxicity Tests, Acute

OBJECTIVETo explore the biological activity of recombinant human single-chain antibody against amyloid beta peptide in vitro.

METHODSHuman single-chain antibody against amyloid beta peptide was obtained from recombinant bacteria. The antigen-binding activity of this antibody was measured by enzyme-linked immunosorbent assay (ELISA) and competitive ELISA. Human neuroblastoma SH-SY5Y cells were used as cell models to test the protective role of human single-chain antibody against amyloid beta peptide.

RESULTSRecombinant human single-chain antibody was mainly located in the insoluble inclusion bodies of bacteria. The antibody was dissolved by urea and purified by metal affinity chromatography as active form to bind synthetic amyloid beta peptide 40 or amyloid beta peptide 42. The improvement of the survival rates of human neuroblastoma cells was significantly superior in amyloid peptide 42 plus equimolar antibody group than in amyloid peptide 42 group (P < 0.05), and was significantly superior in the amyloid peptide 40 plus equimolar antibody group than in amyloid peptide 40 group (P < 0.01).

CONCLUSIONThe recombinant human single-chain antibody against beta amyloid peptide 40 from E. coli can partially inhibit the neurotoxicity effect of amyloid beta peptide in vitro.

Amyloid beta-Peptides ; immunology ; metabolism ; toxicity ; Cell Line, Tumor ; Cell Survival ; drug effects ; Humans ; Peptide Fragments ; metabolism ; toxicity ; Protein Binding ; Recombinant Proteins ; pharmacology ; Single-Chain Antibodies ; pharmacology

BACKGROUNDHuman group O red blood cells have great benefit in specialized transfusion areas such as armed conflict and natural calamity. The group B antigen differs structurally from group O antigen only by the addition of one terminal alpha-linked galactose residue. In this study we aimed to remove the terminal galactose from group B red blood cell to get group O red blood cell.

METHODSalpha-galactosidase cDNA was cloned by RT-PCR from Catimor coffee beans grown on Hainan Island of China. The vector for alpha-galactosidase cDNA expression was constructed and transferred into Pichia pastoris cells by electroporation. The transgenic cells were cloned by fermentation and the recombinant alpha-galactosidase was purified by ion exchange chromatography. After studying the biochemical characters of alpha-galactosidase, we have used it in converting human erythrocytes from group B to group O.

RESULTSThe purity of recombinant alpha-galactosidase was higher than 96%, which was thought to be suitable for the use of blood conversion. Enzymatically converted human group O red blood cells (ECHORBC) exhibited membrane integrity, metabolic integrity, normal cell deformation and morphology. There were no coagulation between ECHORBC and any group of human blood. The ECHORBC will keep normal structure and function for a period of 21 days at 4 degrees C in monoammoniumphosphate nutrient solution. Experiments with Rhesus monkeys and gibbons showed that transfusion of enzymatically converted erythrocytes was safe.

CONCLUSIONECHORBC can be easily obtained from group B red blood cell by alpha-galactosidase digestion. This study suggests that ECHORBC could be transfused to patients safely and efficiently.

ABO Blood-Group System ; classification ; metabolism ; Animals ; Blood Transfusion ; Cloning, Molecular ; Coffee ; enzymology ; Erythrocytes ; metabolism ; Humans ; Macaca mulatta ; Quality Control ; Recombinant Proteins ; isolation & purification ; pharmacology ; alpha-Galactosidase ; immunology ; isolation & purification ; pharmacology ; toxicity