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1.
Chinese Journal of Biotechnology ; (12): 312-320, 2021.
Article in Chinese | WPRIM | ID: wpr-878564

ABSTRACT

To enhance recombinant protein production by CHO cells, We compared the impact of overexpression of metabolic enzymes, namely pyruvate carboxylase 2 (PYC2), malate dehydrogenase Ⅱ (MDH2), alanine aminotransferase Ⅰ (ALT1), ornithine transcarbamylase (OTC), carbamoyl phosphate synthetase Ⅰ (CPSⅠ), and metabolism related proteins, namely taurine transporter (TAUT) and Vitreoscilla hemoglobin (VHb), on transient expression of anti-hLAG3 by ExpiCHO-S. Overexpression of these 7 proteins could differentially enhance antibody production. OTC, CPSI, MDH2, and PYC2 overexpression could improve antibody titer by 29.2%, 27.6%, 24.1%, and 20.3%, respectively. Specifically, OTC and MDH2 could obviously improve early-stage antibody production rate and the culture period was shortened by 4 days compared with that of the control. In addition, OTC and MDH2 had little impact on the affinity of anti-hLAG3. In most cases, overexpression of these proteins had little impact on the cell growth of ExpiCHO-S. MDH2 and ALT1 overexpression in H293T cells could also improve antibody production. Overall, overexpression of enzymes involved in cellular metabolism is an effective tool to improve antibody production in transient expression system.


Subject(s)
Animals , CHO Cells , Cricetinae , Cricetulus , Enzymes/metabolism , Recombinant Proteins/genetics
2.
Chinese Journal of Biotechnology ; (12): 1041-1050, 2020.
Article in Chinese | WPRIM | ID: wpr-826872

ABSTRACT

In recent years, the demand of biologics has increased rapidly. Cell culture process with perfusion mode has become more and more popular due to its high productivity, good quality and high efficiency. In this paper, the unique operation and the details of process optimization for perfusion culture mode are discussed by comparing with traditional batch culture process. Meanwhile, the progress and strategies in the development and optimization of perfusion culture process in recent years are summarized to provide reference for the future development of mammalian cell perfusion culture technology.


Subject(s)
Animals , Batch Cell Culture Techniques , Bioreactors , Reference Standards , CHO Cells , Cricetulus , Mammals , Perfusion
3.
Chinese Journal of Biotechnology ; (12): 1209-1215, 2020.
Article in Chinese | WPRIM | ID: wpr-826857

ABSTRACT

Bioreactors have been central in monoclonal antibodies and vaccines manufacturing by mammalian cells in suspension culture. Numerical simulation of five impeller combinations in a stirred bioreactor was conducted, and characteristics of velocity vectors, distributions of gas hold-up, distributions of shear rate in the bioreactor using 5 impeller combinations were numerically elucidated. In addition, genetically engineered CHO cells were cultivated in bioreactor installed with 5 different impeller combinations in fed-batch culture mode. The cell growth and antibody level were directly related to the maximum shear rate in the bioreactor, and the highest viable cell density and the peak antibody level were achieved in FBMI3 impeller combination, indicating that CHO cells are sensitive to shear force produced by impeller movement when cells were cultivated in bioreactor at large scale, and the maximum shear rate would play key roles in scaling-up of bioreactor at industrial scale.


Subject(s)
Animals , Batch Cell Culture Techniques , Bioreactors , Reference Standards , CHO Cells , Cell Count , Computer Simulation , Cricetinae , Cricetulus , Industrial Microbiology , Methods
4.
Biol. Res ; 53: 52, 2020. tab, graf
Article in English | LILACS | ID: biblio-1142419

ABSTRACT

BACKGROUND: Chinese hamster ovary (CHO) cells are the most commonly used mammalian host cell In the commercial-scale production of biopharmaceutical proteins. Modification of genes involved in apoptosis may improve the productivity of CHO cells. Executive caspases, including caspases 3 and 7, play critical roles in apoptosis. The effects of the ablation of the caspase 7 gene on proliferation and viability of CHO cells remains unknown. In this study, we applied clustered regularly interspaced short palindromic repeat (CRISPR/Cas9) to target caspase 7 gene of CHO K1 cell via all in one and homology targeted integration strategies. Consequently, the effect of caspase 7 deficiency on cell proliferation, viability, and apoptosis was studied by MTT assay and flow cytometry. RESULTS: Findings of gel electrophoresis, western blotting, and sequencing confirmed the caspase 7 gene silencing in CHO cells (CHO-KO). Proliferation assay revealed that caspase 7 deficiency in CHO cells resulted in the reduction of proliferation in various CHO-KO clones. Besides, the disruption of caspase 7 had negative effects on cell viability in exposure with NaBu which confirmed by MTT assay. Results of flow cytometry using Anexin V/PI demonstrated that Nabu treatment (11 mM) declined the percentage of live CHO-K1 and CHO-KO cells to 70.3% and 5.79%. These results verified that the CHO-K1 cells were more resistant to apoptosis than CHO-KO, however most of CHO-KO cells undergone early apoptosis (91.9%) which seems to be a fascinating finding. CONCLUSION: These results reveal that caspase 7 may be involved in the cell cycle progression of CHO cells. Furthermore, it seems that targeting caspase 7 is not the ideal route as it had previously been imagined within the prevention of apoptosis but the relation between caspase 7 deficiency, cell cycle arrest, and the occurrence of early apoptosis will require more investigation.


Subject(s)
Animals , Cell Survival , Apoptosis , Cell Proliferation , Caspase 7/deficiency , Cricetulus , Cricetinae , CHO Cells , Caspase 7/genetics
5.
Gac. méd. Méx ; 155(5): 504-510, Sep.-Oct. 2019. graf
Article in English | LILACS | ID: biblio-1286551

ABSTRACT

Cancer is a multifactorial disease that constitutes a serious public health problem worldwide. Prostate cancer advanced stages are associated with the development of androgen-independent tumors and an apoptosis-resistant phenotype that progresses to metastasis. By studying androgen-independent lymphoid nodule carcinoma of the prostate (LNCaP) cells induced to apoptosis by serum elimination, we identified the activation of a non-selective cationic channel of 23pS conductance that promotes incoming Ca2+ currents, as well as apoptosis final stages. arp2cDNA was isolated and identified to be of the same cell type, and mRNA was expressed in Xenopus laevis oocytes, which was found to be associated with the activation of incoming Ca2+ currents and induction to apoptosis. cDNA, which encodes the ARP2 protein, was overexpressed in LNCaP cells and Chinese hamster ovary cells, which induced apoptosis. Our evidence suggests that protein ARP2 overexpression and transit to the cell membrane allows an increased Ca2+ incoming current that initiates the apoptosis process in epithelial-type cells whose phenotype shows resistance to programmed cell death.


Subject(s)
Humans , Animals , Male , Prostatic Neoplasms/pathology , Calcium/metabolism , Apoptosis/physiology , Apoptosis Regulatory Proteins/metabolism , Ovum/metabolism , Prostatic Neoplasms/metabolism , Xenopus laevis , RNA, Messenger/metabolism , Calcium Channels/metabolism , Cricetulus , CHO Cells , DNA, Complementary/isolation & purification , Apoptosis Regulatory Proteins/isolation & purification
6.
Chinese Journal of Biotechnology ; (12): 1071-1078, 2019.
Article in Chinese | WPRIM | ID: wpr-771821

ABSTRACT

The aim of this study is to investigate the effect of the chimeric intron in different directions on the expression of the nerve growth factor (NGF) in recombinant Chinese hamster ovary (CHO) cells. The chimeric intron that contained the splice sequence of the first intron of the human β-globin and the human immunoglobulin heavy chain variable region intron was used. NGF gene was cloned into the expression vectors containing the chimeric intron in the forward or reverse direction, followed by transfecting into CHO cells, and screened under G418 to produce the stable transfected CHO cells. Fluorescence quantitative PCR, ELISA, and Western blotting were performed to detect the recombinant NGF gene expression in CHO cells. The results showed that the chimeric introns could significantly enhance the expression of NGF in recombinant CHO cells. Moreover, the enhancing effect on NGF expression level by the intron in the forward direction showed stronger than that of the reverse direction both at mRNA and protein level. In conclusion, the chimeric intron could increase NGF expression in stably transfected CHO cells and the effect is associated with the direction of the intron insertion.


Subject(s)
Animals , Animals, Genetically Modified , CHO Cells , Cricetinae , Cricetulus , Gene Expression , Humans , Introns , Transfection
7.
Article in Chinese | WPRIM | ID: wpr-774331

ABSTRACT

OBJECTIVE@#To establish 293T cell lines stably expressing Calpain-cleavage related α3 cytoplasmic tail mutants, and to explore the effect of amino acid motifs in integrin β3 cytoplasmic tail on αⅡbβ3-mediated cell function.@*METHODS@#293T cell lines stably co-expressing human wild type integrin αⅡb and full length β3 or mutant β3, including β3-ΔNITY (β3 cytoplasmic tail NITY motif deleted), β3-Δ754 (β3 cytoplasmic tail TNITYRGT motif deleted) and β3-Δ759 (β3 cytoplasmic tail RGT motif deleted) were established. Spreading and adhesion of these stable cell lines on immobilized fibrinogen were tested.@*RESULTS@#293T-αⅡbβ3ΔNITY, 293T-αⅡbβ3Δ754, 293T-αⅡbβ3Δ759 and 293T-αⅡbβ3 cell lines were successfully established. Compared with the 293T cells, 293T-αⅡbβ3 cells which expressed full β3, possessed well adhesion and spread ability on immobilized fibrinogen, suggesting it can be as a surrogate for platelet. Compared with 293T-αⅡbβ3 cells, the 293T-αⅡbβ3ΔNITY cells showed a partial impairment of adhesion and spreadability on immobilized fibrinogen. while the 293T-αⅡbβ3Δ754 cells and 293T-αⅡbβ3Δ759 cells failed to adhere or spread on immobilized fibrinogen.@*CONCLUSION@#To the cell spreading function mediated by integrin β3, RGT motif is vital, while NITY can be dispensable. These established 293T cell lines stably expressing different β3 mutants provide a solid basis for a further analysis of mass spectrometry.


Subject(s)
Amino Acid Motifs , Animals , CHO Cells , Cell Adhesion , Cricetinae , Cricetulus , HEK293 Cells , Humans , Integrin beta3 , Genetics , Metabolism , Platelet Glycoprotein GPIIb-IIIa Complex , Genetics , Metabolism , Signal Transduction
8.
Article in English | WPRIM | ID: wpr-727936

ABSTRACT

In patients with epilepsy, depression is a common comorbidity but difficult to be treated because many antidepressants cause pro-convulsive effects. Thus, it is important to identify the risk of seizures associated with antidepressants. To determine whether paroxetine, a very potent selective serotonin reuptake inhibitor (SSRI), interacts with ion channels that modulate neuronal excitability, we examined the effects of paroxetine on Kv3.1 potassium channels, which contribute to highfrequency firing of interneurons, using the whole-cell patch-clamp technique. Kv3.1 channels were cloned from rat neurons and expressed in Chinese hamster ovary cells. Paroxetine reversibly reduced the amplitude of Kv3.1 current, with an IC₅₀ value of 9.43 µM and a Hill coefficient of 1.43, and also accelerated the decay of Kv3.1 current. The paroxetine-induced inhibition of Kv3.1 channels was voltage-dependent even when the channels were fully open. The binding (k₊₁) and unbinding (k₋₁) rate constants for the paroxetine effect were 4.5 µM⁻¹s⁻¹ and 35.8 s⁻¹, respectively, yielding a calculated K(D) value of 7.9 µM. The analyses of Kv3.1 tail current indicated that paroxetine did not affect ion selectivity and slowed its deactivation time course, resulting in a tail crossover phenomenon. Paroxetine inhibited Kv3.1 channels in a usedependent manner. Taken together, these results suggest that paroxetine blocks the open state of Kv3.1 channels. Given the role of Kv3.1 in fast spiking of interneurons, our data imply that the blockade of Kv3.1 by paroxetine might elevate epileptic activity of neural networks by interfering with repetitive firing of inhibitory neurons.


Subject(s)
Animals , Antidepressive Agents , Clone Cells , Comorbidity , Cricetinae , Cricetulus , Depression , Epilepsy , Female , Fires , Humans , Interneurons , Ion Channels , Neurons , Ovary , Paroxetine , Patch-Clamp Techniques , Rats , Seizures , Serotonin , Shaw Potassium Channels , Tail
9.
Article in English | WPRIM | ID: wpr-727861

ABSTRACT

Extra-hypothalamic growth hormone-releasing hormone (GHRH) plays an important role in reproduction. To study the treatment effect of Grin (a novel hGHRH homodimer), the infertility models of 85 male Chinese hamsters were established by intraperitoneally injecting 20 mg/kg of cyclophosphamide once in a week for 5 weeks and the treatment with Grin or human menopausal gonadotropin (hMG) as positive control was evaluated by performing a 3-week mating experiment. 2–8 mg/kg of Grin and 200 U/kg of hMG showed similar effect and different pathological characteristics. Compared to the single cyclophosphamide group (0%), the pregnancy rates (H-, M-, L-Grin 26.7, 30.8, 31.3%, and hMG 31.3%) showed significant difference, but there was no difference between the hMG and Grin groups. The single cyclophosphamide group presented loose tubules with pathologic vacuoles and significant TUNEL positive cells. Grin induced less weight of body or testis, compactly aligned tubules with little intra-lumens, whereas hMG caused more weight of body or testis, enlarging tubules with annular clearance. Grin presented a dose-dependent manner or cell differentiation-dependentincrease in testicular GHRH receptor, and did not impact the levels of blood and testicular GH, testosterone. Grin promotes fertility by proliferating and differentiating primitive cells through up-regulating testicular GHRH receptor without triggering GH secretion, which might solve the etiology of oligoasthenozoospermia.


Subject(s)
Animals , Cricetinae , Cricetulus , Cyclophosphamide , Fertility , Gonadotropins , Growth Hormone-Releasing Hormone , Humans , In Situ Nick-End Labeling , Infertility , Infertility, Male , Male , Male , Pregnancy Rate , Reproduction , Testis , Testosterone , Vacuoles
10.
Article in Chinese | WPRIM | ID: wpr-345329

ABSTRACT

<p><b>OBJECTIVE</b>To generate recombinant GPⅢa as an alternative source for HPA-1a antigen and combine it with Luminex xMAP beads for the detection of HPA-1a-specific alloantibody.</p><p><b>METHODS</b>The full coding region of ITGB3 gene was amplified and ligated with pcDNA3.1. The recombinant plasmid was transfected into CHO cells, and those with stable expression were screened with G418. Expressed protein was identified and coupled with Luminex xMAP beads, which were then reacted with sera samples. Subsequently, phycoerythrin-labeled anti-species IgG antibody was added to the reaction wells and the median fluorescence was determined on a Luminex-100 analyzer.</p><p><b>RESULTS</b>DNA sequencing confirmed that the cloned ITGB3 gene was HPA-1aa. The recombinant GPⅢa was coupled with Luminex xMAP beads. The sensitivity of Luminex beads assay to detect HPA-1a antibody was dilution 1/32 (3.125 U/mL). The Luminex beads assay could specifically identify the HPA-1a antibody from the test sera, and the results were consistent with that of monoclonal antibody-specific immobilization of platelet antigens (MAIPA) technology. Cross-reactivity was not observed with the samples containing HLA, ABO and other HPA antibodies (HPA-3a and HPA-5b). The results illustrated that to detect HPA antibody with Luminex xMAP beads technology is feasible.</p><p><b>CONCLUSION</b>Recombinant GPⅢa was successfully obtained and used to establish a Luminex technology-based method for the detection of HPA antibodies.</p>


Subject(s)
Animals , Antigens, Human Platelet , Allergy and Immunology , Autoantibodies , Allergy and Immunology , Base Sequence , Blotting, Western , CHO Cells , Cricetinae , Cricetulus , Humans , Immunoassay , Methods , Integrin beta3 , Genetics , Allergy and Immunology , Metabolism , Microspheres , Recombinant Proteins , Allergy and Immunology , Metabolism , Reproducibility of Results
11.
Article in English | WPRIM | ID: wpr-180606

ABSTRACT

Chigger mites are parasites of rodents and other vertebrates, invertebrates, and other arthropods, and are the only vectors of scrub typhus, in addition to other zoonoses. Therefore, investigating their distribution, diversity, and seasonal abundance is important for public health. Rodent surveillance was conducted at 6 districts in Shandong Province, northern China (114–112°E, 34–38°N), from January to December 2011. Overall, 225/286 (78.7%) rodents captured were infested with chigger mites. A total of 451 chigger mites were identified as belonging to 5 most commonly collected species and 3 genera in 1 family. Leptotrombidium scutellare and Leptotrombidium intermedia were the most commonly collected chigger mites. L. scutellare (66.2%, 36.7%, and 49.0%) was the most frequently collected chigger mite from Apodemus agrarius, Rattus norvegicus, and Microtus fortis, respectively, whereas L. intermedia (61.5% and 63.2%) was the most frequently collected chigger mite from Cricetulus triton and Mus musculus, respectively. This study demonstrated a relatively high prevalence of chigger mites that varied seasonally in Shandong Province, China.


Subject(s)
Animals , Arthropods , Arvicolinae , China , Cricetinae , Cricetulus , Humans , Invertebrates , Mice , Mites , Murinae , Neptune , Parasites , Prevalence , Public Health , Rats , Rodentia , Scrub Typhus , Seasons , Trombiculidae , Vertebrates , Zoonoses
12.
Article in English | WPRIM | ID: wpr-296493

ABSTRACT

4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is a potent and prevalent nitrosamine procarcinogen found in cigarette smoke. The aim of this work is to study alterations in peroxiredoxin (Prx) expression induced by NNK during carcinogenesis. Characterization of Prx genes from hamster was performed using bioinformatics. V79 cells were induced with different concentrations of NNK (0.1-0.4 mg/mL), and the expression levels of six Prx genes (Prx1-Prx6) were measured by qRT-PCR 24 h following NNK treatment. Prx gene expression was induced by NNK stress, and the highest transcription levels were induced by over 20.42-fold relative to that of the control. NNK induced alterations in Prx expression over the course of lung cancer, which means Prxs may play important roles in ROS detoxification under NNK stress and their functions are complementary.


Subject(s)
Animals , Carcinogens , Toxicity , Cell Line , Cell Survival , Cricetinae , Cricetulus , Dose-Response Relationship, Drug , Gene Expression Regulation , Nitrosamines , Toxicity , Peroxiredoxins , Genetics , Metabolism
13.
Article in Chinese | WPRIM | ID: wpr-323783

ABSTRACT

<p><b>OBJECTIVE</b>To investigate whether inhalable particulate matters can cause the damage of chromosome or mitotic apparatus to produce micronucleus, and to evaluate genetic toxicology of moxa smoke on chromosome.</p><p><b>METHODS</b>By MTT method, the 24 h half maximal inhibitory concentration (IC50) of moxa smoke condensation (MSC) on Chinese hamster ovary (CHO) cells was 0.087 mg/mL. CHO cells, which were cultured in vitro, were divided into a solvent control group, a positive control group (cyclophosphamide as solvent), a low concentration group, a moderate concentration group and a high concentration group. The low concentration group, moderate concentration group and high concentration group were set approximately 1/8, 1/4, 1/2 of IC50, respectively. Whether micronucleus had dose-effect response induced by the damage of chromosome or mitotic apparatus was observed after CHO cells were contaminated by MSC in the low concentration group, moderate concentration group and high concentration group.</p><p><b>RESULTS</b>The rate of micronucleus induced by MSC in the low concentration group, moderate concentration group and high concentration group was higher than that in the solvent control group (all P < 0.05), which presented dosage-effect response. The experiment was repeated 3 times, indicating it was repeatable with statistical significance.</p><p><b>CONCLUSION</b>High concentration of MSC shows toxicity to induce chromosome damage, which disappears at low concentration. The genetic toxicology is also dependent on concentration, and the concentration of moxa smoke is essential. In clinical treatment, it is noted to control the level of moxa smoke, while the clinical safety standard of moxa smoke concentration is in need of further study.</p>


Subject(s)
Air Pollutants , Animals , CHO Cells , Cell Nucleus , Genetics , Cricetinae , Cricetulus , Inhalation Exposure , Micronucleus Tests , Moxibustion , Particulate Matter , Smoke
14.
Article in English | WPRIM | ID: wpr-121858

ABSTRACT

BACKGROUND: Isoflavones are biologically active compounds that occur naturally in a variety of plants, with relatively high levels in soybean. Tectorigenin, an isoflavone, protects against hydrogen peroxide (H2O2)-induced cell damage. However, the underlying mechanism is unknown. METHODS: The MTT assay was performed to determine cell viability. Catalase activity was assessed by determining the amount of enzyme required to degrade 1 μM H2O2. Protein expression of catalase, phospho-extracellular signal-regulated kinase (ERK), IκB-α, and NF-κB were evaluated by Western blot analysis. A mobility shift assay was performed to assess the DNA-binding ability of NF-κB. Transient transfection and a NF-κB luciferase assay were performed to assess transcriptional activity. RESULTS: Tectorigenin reduced H2O2-induced death of Chinese hamster lung fibroblasts (V79-4). In addition, tectorigenin increased the activity and protein expression of catalase. Blockade of catalase activity attenuated the protective effect of tectorigenin against oxidative stress. Furthermore, tectorigenin enhanced phosphorylation of ERK and nuclear expression of NF-κB, while inhibition of ERK and NF-κB attenuated the protective effect of tectorigenin against oxidative stress. CONCLUSIONS: Tectorigenin protects cells against oxidative damage by activating catalase and modulating the ERK and NF-κB signaling pathway.


Subject(s)
Animals , Blotting, Western , Catalase , Cell Death , Cell Survival , Cricetinae , Cricetulus , Electrophoretic Mobility Shift Assay , Extracellular Signal-Regulated MAP Kinases , Fibroblasts , Hydrogen Peroxide , Isoflavones , Luciferases , Lung , NF-kappa B , Oxidative Stress , Phosphorylation , Phosphotransferases , Soybeans , Transfection
15.
Article in Chinese | WPRIM | ID: wpr-287959

ABSTRACT

<p><b>OBJECTIVE</b>To explore the function of a novel nonsense mutation c.1476G>A of ITGB3 gene using an in vitro expression system.</p><p><b>METHODS</b>An eukaryotic expression vector containing ITGB3 c.1476G>A cDNA was generated by site-directed mutagenesis and transformed into E.coli. Plasmid DNA was extracted and sequenced to confirm the target mutations. Wild-type and mutant recombination plasmids were transfected into Chinese hamster ovarian cancer (CHO) cells by nonliposome method, and the stable expression cells were harvested by G418 screening. The ITGB3 gene mRNA transcription and GPIIIa expression level in CHO cells were detected with real-time quantitative PCR, Western blotting and flow cytometry, respectively.</p><p><b>RESULTS</b>The eukaryotic expression vectors of wild ITGB3 cDNA and c.1476G>A mutant were successfully constructed. CHO cells with stable expression were obtained after transfection and screening. Compared with the wild-type transfected cells, the amount of CD61 antigen expression was 37% and mRNA transcription level was only 6% in the mutant-transfected cells. Full length GPIIIa protein was found only in the stably wild-type-transfected cells, but not in mutant-transfected cells by Western blotting analysis.</p><p><b>CONCLUSION</b>The ITGB3 c.1476G>A mutation can decrease the transcription level and further affect GPIIIa synthesis and CD61 antigen expression.</p>


Subject(s)
Animals , Base Sequence , Blood Platelets , Cell Biology , Metabolism , CHO Cells , Cloning, Molecular , Codon, Nonsense , Genetics , Cricetinae , Cricetulus , Humans , Integrin beta3 , Genetics , Metabolism , Molecular Sequence Data , Plasmids , Genetics , Metabolism , Point Mutation
16.
Article in English | WPRIM | ID: wpr-296539

ABSTRACT

<p><b>OBJECTIVE</b>To determine the hepatitis B immunoprophylactic failure rate in infants born to hepatitis B virus (HBV) infected mothers and to characterize HBV genes.</p><p><b>METHODS</b>HBV-serological testing was conducted for pregnant women and infants. The complete genomes of 30 HBV isolates were sequenced, and genetic characteristics were analyzed using MEGA 5 software.</p><p><b>RESULTS</b>The immunoprophylactic failure rate for infants who had completed the scheduled hepatitis B vaccination program was 5.76% (32/556). High sequence homology (99.8%-100%) was observed in 8 of the 10 mother-infant pairs. We identified 19 subgenotype C2 strains, 9 subgenotype B2 strains, and 2 subgenotype C1 strains. Three serotypes were detected: adr (19/30), adw (9/30), and ayw (2/30). The frequency of amino acid mutation of the 'a' determinant region was 16.67% (5/30), including that of Q129H, F134Y, S136Y, and G145E. We detected 67 amino acid mutations in the basal core promoter, precore, and core regions of the genome.</p><p><b>CONCLUSION</b>The immunoprophylactic failure rate in infants born to HBV-infected mothers is low in the regions of China examined during this study. Moreover, HBV mutation in the 'a' determinant region could not account for immunoprophylactic failure for all infants.</p>


Subject(s)
Adult , Animals , CHO Cells , China , Epidemiology , Cricetinae , Cricetulus , Female , Hepatitis B , Epidemiology , Hepatitis B Vaccines , Therapeutic Uses , Hepatitis B virus , Genetics , Humans , Infant, Newborn , Infectious Disease Transmission, Vertical , Mutation , Phylogeny , Pregnancy , Treatment Failure , Young Adult
17.
Article in English | WPRIM | ID: wpr-728549

ABSTRACT

Paroxetine, a selective serotonin reuptake inhibitor (SSRI), has been reported to have an effect on several ion channels including human ether-a-go-go-related gene in a SSRI-independent manner. These results suggest that paroxetine may cause side effects on cardiac system. In this study, we investigated the effect of paroxetine on Kv1.5, which is one of cardiac ion channels. The action of paroxetine on the cloned neuronal rat Kv1.5 channels stably expressed in Chinese hamster ovary cells was investigated using the whole-cell patch-clamp technique. Paroxetine reduced Kv1.5 whole-cell currents in a reversible concentration-dependent manner, with an IC50 value and a Hill coefficient of 4.11 microM and 0.98, respectively. Paroxetine accelerated the decay rate of inactivation of Kv1.5 currents without modifying the kinetics of current activation. The inhibition increased steeply between -30 and 0 mV, which corresponded with the voltage range for channel opening. In the voltage range positive to 0 mV, inhibition displayed a weak voltage dependence, consistent with an electrical distance delta of 0.32. The binding (k(+1)) and unbinding (k(-1)) rate constants for paroxetine-induced block of Kv1.5 were 4.9 microM(-1)s(-1) and 16.1 s-1, respectively. The theoretical K(D) value derived by k(-1)/k(+1) yielded 3.3 microM. Paroxetine slowed the deactivation time course, resulting in a tail crossover phenomenon when the tail currents, recorded in the presence and absence of paroxetine, were superimposed. Inhibition of Kv1.5 by paroxetine was use-dependent. The present results suggest that paroxetine acts on Kv1.5 currents as an open-channel blocker.


Subject(s)
Animals , Clone Cells , Cricetinae , Cricetulus , Female , Humans , Inhibitory Concentration 50 , Ion Channels , Kinetics , Neurons , Ovary , Paroxetine , Patch-Clamp Techniques , Rats , Serotonin , Tail
18.
Article in English | WPRIM | ID: wpr-728535

ABSTRACT

Sertraline, a selective serotonin reuptake inhibitor (SSRI), has been reported to lead to cardiac toxicity even at therapeutic doses including sudden cardiac death and ventricular arrhythmia. And in a SSRI-independent manner, sertraline has been known to inhibit various voltage-dependent channels, which play an important role in regulation of cardiovascular system. In the present study, we investigated the action of sertraline on Kv1.5, which is one of cardiac ion channels. The eff ect of sertraline on the cloned neuronal rat Kv1.5 channels stably expressed in Chinese hamster ovary cells was investigated using the whole-cell patch-clamp technique. Sertraline reduced Kv1.5 whole-cell currents in a reversible concentration-dependent manner, with an IC50 value and a Hill coefficient of 0.71 microM and 1.29, respectively. Sertraline accelerated the decay rate of inactivation of Kv1.5 currents without modifying the kinetics of current activation. The inhibition increased steeply between -20 and 0 mV, which corresponded with the voltage range for channel opening. In the voltage range positive to +10 mV, inhibition displayed a weak voltage dependence, consistent with an electrical distance delta of 0.16. Sertraline slowed the deactivation time course, resulting in a tail crossover phenomenon when the tail currents, recorded in the presence and absence of sertraline, were superimposed. Inhibition of Kv1.5 by sertraline was use-dependent. The present results suggest that sertraline acts on Kv1.5 currents as an open-channel blocker.


Subject(s)
Animals , Arrhythmias, Cardiac , Cardiovascular System , Clone Cells , Cricetinae , Cricetulus , Death, Sudden, Cardiac , Female , Inhibitory Concentration 50 , Ion Channels , Kinetics , Neurons , Ovary , Patch-Clamp Techniques , Rats , Serotonin , Sertraline , Tail
19.
Indian J Exp Biol ; 2015 Apr; 53(4): 195-201
Article in English | IMSEAR | ID: sea-158416

ABSTRACT

Erythropoietin is a glycohormone involved in the regulation of the blood cell levels. It is a 166 amino acid protein having 3 N-glycosylation and one O-linked glycosylation sites, and is used to treat anaemia related illness. Though human recombinant erythropoietin (rEPO) is produced in CHO cells, the loss in quality control is 80% due to incomplete glycosylation of the rEPO with low levels of fully glycosylated active rEPO. Here, we describe the expression from CHO cells of fully glycosylated human rEPO when expressed as a GPI anchored molecule (rEPO-g). The results demonstrated the production of a homogenous completely glycosylated human rEPO-g as a 42 kD band without any low molecular weight glycoform variants as shown by affinity chromatography followed by SDS-PAGE and anti-human EPO specific western blot. The western blot using specific monoclonal antibody is the available biochemical technique to prove the presence of homogeneity in the expressed recombinant protein. The GPI anchor can be removed during the purification process to yield a therapeutically relevant recombinant erythropoietin molecule cells with a higher in vivo biological activity due to its high molecular weight of 40 kD. This is possibly the first report on the production of a homogenous and completely glycosylated human rEPO from CHO cells for efficient therapy.


Subject(s)
Animals , Base Sequence , CHO Cells , Cricetinae , Cricetulus , Erythropoietin/metabolism , Glycosylation , Glycosylphosphatidylinositols/metabolism , Humans , Polymerase Chain Reaction , Recombinant Proteins/metabolism
20.
Mem. Inst. Oswaldo Cruz ; 110(1): 1-22, 03/02/2015. tab, graf
Article in English | LILACS | ID: lil-741625

ABSTRACT

An increasingly asked question is 'can we confidently link bats with emerging viruses?'. No, or not yet, is the qualified answer based on the evidence available. Although more than 200 viruses - some of them deadly zoonotic viruses - have been isolated from or otherwise detected in bats, the supposed connections between bats, bat viruses and human diseases have been raised more on speculation than on evidence supporting their direct or indirect roles in the epidemiology of diseases (except for rabies). However, we are convinced that the evidence points in that direction and that at some point it will be proved that bats are competent hosts for at least a few zoonotic viruses. In this review, we cover aspects of bat biology, ecology and evolution that might be relevant in medical investigations and we provide a historical synthesis of some disease outbreaks causally linked to bats. We provide evolutionary-based hypotheses to tentatively explain the viral transmission route through mammalian intermediate hosts and to explain the geographic concentration of most outbreaks, but both are no more than speculations that still require formal assessment.


Subject(s)
Animals , Humans , Antineoplastic Agents, Phytogenic/isolation & purification , Antioxidants/isolation & purification , Fatty Acids/analysis , Industrial Waste/analysis , Malus/chemistry , Plant Oils/isolation & purification , Seeds/chemistry , Antineoplastic Agents, Phytogenic/adverse effects , Antineoplastic Agents, Phytogenic/economics , Antineoplastic Agents, Phytogenic/pharmacology , Antioxidants/adverse effects , Antioxidants/economics , Antioxidants/pharmacology , Cell Line, Tumor , Chemical Phenomena , CHO Cells , Cricetulus , Cell Proliferation/drug effects , Dietary Supplements/adverse effects , Dietary Supplements/economics , Fatty Acids, Nonesterified/adverse effects , Fatty Acids, Nonesterified/analysis , Fatty Acids, Nonesterified/economics , Fatty Acids/adverse effects , Fatty Acids/economics , Food Preservatives/adverse effects , Food Preservatives/economics , Food Preservatives/isolation & purification , Food Preservatives/pharmacology , Food-Processing Industry/economics , Fruit/chemistry , Fruit/economics , India , Industrial Waste/economics , Linoleic Acid/adverse effects , Linoleic Acid/analysis , Linoleic Acid/economics , Oleic Acid/adverse effects , Oleic Acid/analysis , Oleic Acid/economics , Plant Oils/chemistry , Plant Oils/economics , Plant Oils/pharmacology
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