Madin-Darby Canine Kidney Cell Line Research Articles

Characterization and Immunogenicity of Influenza H7N9 Vaccine Antigens Produced Using a Serum-Free Suspension MDCK Cell-Based Platform.

Human infections with avian-origin H7N9 influenza A viruses were first reported in China, and an approximately 38% human mortality rate was described across six waves from February 2013 to September 2018. Vaccination is one of the most cost-effective ways to reduce morbidity and mortality during influenza epidemics and pandemics. Egg-based platforms for the production of influenza vaccines are labor-intensive and unable to meet the surging demand during pandemics. Therefore, cell culture-based technology is becoming the alternative strategy for producing influenza vaccines. The current influenza H7N9 vaccine virus (NIBRG-268), a reassortant virus from A/Anhui/1/2013 (H7N9) and egg-adapted A/PR/8/34 (H1N1) viruses, could grow efficiently in embryonated eggs but not mammalian cells. Moreover, a freezing-dry formulation of influenza H7N9 vaccines with long-term stability will be desirable for pandemic preparedness, as the occurrence of influenza H7N9 pandemics is not predictable. In this study, we adapted a serum-free anchorage-independent suspension Madin-Darby Canine Kidney (MDCK) cell line for producing influenza H7N9 vaccines and compared the biochemical characteristics and immunogenicity of three influenza H7N9 vaccine antigens produced using the suspension MDCK cell-based platform without freeze-drying (S-WO-H7N9), the suspension MDCK cell-based platform with freeze-drying (S-W-H7N9) or the egg-based platform with freeze-drying (E-W-H7N9). We demonstrated these three vaccine antigens have comparable biochemical characteristics. In addition, these three vaccine antigens induced robust and comparable neutralizing antibody (NT; geometric mean between 1016 and 4064) and hemagglutinin-inhibition antibody (HI; geometric mean between 640 and 1613) titers in mice. In conclusion, the serum-free suspension MDCK cell-derived freeze-dried influenza H7N9 vaccine is highly immunogenic in mice, and clinical development is warranted.

Madin-Darby Canine Kidney (MDCK) Cell line permeability of Curcumin loaded Phycocyanin nanosponges - In-Vitro study

Blood Brain barrier (BBB) is a natural protective wall in the brain to restrict the invasion of xenobiotics or toxic chemicals. This, in turn, becomes a major obstacle for researchers and industry people in formulating new drugs to treat brain disorders like brain tumors, Alzheimer's disease, multiple sclerosis, meningitis, and so on. The purpose of this research is to study the in-vitro cytotoxicity & BBB permeation of curcumin-loaded phycocyanin nanosponges (Cur-PC NS) using Madin-Darby Canine Kidney (MDCK) cell lines. Cell viability of Cur-PC NS was performed using 3-(4,5-dimethylthiazol-2-yl)-2.5- diphenyltetrazolium bromide (MTT) assay, the transepithelial electrical resistance (TEER) values, and permeability coefficient were measured to test the integrity of monolayer of MDCK cell line. Results of the current study showed that Cur-PC NS at 50µM, 85% of MDCK cells are more viable and there was a significant (p<0.01) reduction in TEER values up to 48 hours when compared to the curcumin. The permeability coefficient of nanosponges produced a 2.5-fold increase in enhancement ratio with a Papp value of 1.94±0.11×10-6 cm/s and 4.86±0.04×10-6cm/s for curcumin and Cur-PC NS respectively. Results of the study can be concluded that phycocyanin nanosponges can be used as a carrier for curcumin to permeate the BBB which may play a major role in the treatment of various brain disorders. Future studies are needed to substantiate the exact mechanism of permeability with clarification of efflux transporters presented in BBB.

Sialylated and sulfated N-Glycans in MDCK and engineered MDCK cells for influenza virus studies

The Madin-Darby canine kidney (MDCK) cell line is an in vitro model for influenza A virus (IAV) infection and propagation. MDCK-SIAT1 (SIAT1) and humanized MDCK (hCK) cell lines are engineered MDCK cells that express N-glycans with elevated levels of sialic acid (Sia) in α2,6-linkage (α2,6-Sia) that are recognized by many human IAVs. To characterize the N-glycan structures in these cells and the potential changes compared to the parental MDCK cell line resulting from engineering, we analyzed the N-glycans from these cells at different passages, using both mass spectrometry and specific lectin and antibody binding. We observed significant differences between the three cell lines in overall complex N-glycans and terminal galactose modifications. MDCK cells express core fucosylated, bisected complex-type N-glycans at all passage stages, in addition to expressing α2,6-Sia on short N-glycans and α2,3-Sia on larger N-glycans. By contrast, SIAT1 cells predominantly express α2,6-Sia glycans and greatly reduced level of α2,3-Sia glycans. Additionally, they express bisected, sialylated N-glycans that are scant in MDCK cells. The hCK cells exclusively express α2,6-Sia glycans. Unexpectedly, hCK glycoproteins bound robustly to the plant lectin MAL-1, indicating α2,3-Sia glycans, but such binding was not Sia-dependent and closely mirrored that of an antibody that recognizes glycans with terminal 3-O-sulfate galactose (3-O-SGal). The 3-O-SGal epitope is highly expressed in N-glycans on multiple hCK glycoproteins. These results indicate vastly different N-glycomes between MDCK cells and the engineered clones that could relate to IAV infectivity.

Evaluation of cytotoxicity and antiviral activity of Rhazya stricta Decne leaves extract against influenza A/PR/8/34 (H1N1)

Influenza viruses have developed resistance to the current classes of drugs, which means they could eventually become more virulent and cause more mortality and hospitalization. Our study aims to investigate the antiviral activity of Rhazya stricta Decne leaves extract in vitro and search for new promising drugs from R. stricta identified compounds in silico. The study was performed in vitro by utilizing Madin-Darby Canine Kidney cell line (MDCK) as a substrate for the influenza virus and estimating the inhibition performance of the plant leaves extract. Additionally, in silico screening was conducted to explore the antiviral activity of R. stricta phytochemicals. We investigated the cytotoxicity of R. stricta leaves extract and its antiviral activity against influenza virus (A/Puerto Rico/8/34 (H1N1)) using the MTT assay. The mode of action of the plant leaves extract during the viral life cycle was tested using time-of-addition assay. In silico analyses were performed, including molecular docking, drug-likeness analysis, and toxicity risk assessment, to state the leading compounds to be developed into an anti-influenza virus drug. The 50% cytotoxicity concentration of the leaves extract was CC50: 184.6 µg/mL, and the 50% inhibition concentration was CI50: 19.71 µg\\mL. The time of addition assay revealed that R. stricta leaves extract exerted its activity in the late step of the influenza virus replication cycle. In comparison to Oseltamivir, the leading compounds showed better binding affinity and can be developed into oral drugs with low toxicity risk. Isolation and purification of the leading compounds and testing their antiviral activity in vitro and in vivo are required.

In vitro anti-influenza assessment of anionic compounds ascorbate, acetate and citrate

BackgroundInfluenza A virus (IAV) infection remains a serious public health threat. Due to drug resistance and side effects of the conventional antiviral drugs, repurposing the available natural compounds with high tolerability and fewer side effects has attracted researchers’ attention. The aim of this study was to screen in vitro anti-influenza activity of three anionic compounds ascorbate, acetate, and citrate.MethodsThe non-cytotoxic concentration of the compounds was determined by MTT assay and examined for the activity against IAV in simultaneous, pre-, and post-penetration combination treatments over 1 h incubation on Madin-Darby Canine Kidney (MDCK) cell line. The virus titer and viral load were determined using hemagglutination assay (HA) and qPCR, respectively. Few pro-inflammatory and anti-inflammatory cytokines were evaluated at RNA and protein levels by qPCR and ELISA, respectively.ResultsThe non-cytotoxic concentrations of the ascorbate (200 mg/ml), acetate and citrate (both 3 mg/ml) reduced the viral titer by 6.5, 4.5, and 1.5 logs in the simultaneous combination treatment. The M protein gene copy number decreased significantly in simultaneous treatment (P < 0.01). The expression of cytokines was also affected by the treatment of these compounds.ConclusionsThese anionic compounds could affect the influenza virus load, thereby reducing pro-inflammatory cytokines and increasing anti-inflammatory cytokines levels.

Hydroxyl containing benzo[b]thiophene analogs mitigates the acrylamide induced oxidative stress in the zebrafish larvae by stabilizing the glutathione redox cycle

AimsThis study aims to elucidate a systematic free-radical quenching ability of synthesized benzo[b]thiophene derivatives using in vitro assays and acrylamide induced oxidatively stressed model in zebrafish larvae. Materials and methodsAntioxidant activity of the compounds was evaluated using in vitro methods. The toxicity of the compounds was evaluated in Madin-Darby Canine Kidney (MDCK) cell line and zebrafish embryos. Oxidative stress was generated by acrylamide (1 mM) in zebrafish larvae and treated with compounds to evaluate the in vivo antioxidant ability. Specific fluorescence dyes were used to detect ROS generation, lipid peroxidation, and cell death followed by gene expression using RT PCR. Density functional theory (DFT) and in silico pharmacokinetics were also studied. Key findingsCompound BP and EP have a greater in vitro free radical scavenging ability. The maximum tolerated concentration (MTC) of the compounds in zebrafish larvae is 80 μM. The antioxidant system in zebrafish larvae was dysregulated due to acrylamide exposure and improvement was found while treating acrylamide exposed larvae with compounds 1-(3-hydroxybenzo[b]thiophen-2-yl) ethanone (BP) and 1-(3-hydroxybenzo[b]thiophen-2-yl) propan-1-one hydrate (EP). Compound BP and EP enhanced the SOD and CAT activity, reduced the ROS and lipid peroxidation level, thus decreasing cell death in zebrafish larvae. Compound BP and EP also improved the glutathione redox cycle by stabilizing glutathione-related gene expressions. SignificanceHydroxyl-containing compounds BP and EP are promising lead molecules for pathological conditions related to oxidative stress, which showed an attenuated effect on acrylamide-induced oxidative stress in zebrafish larvae by enhancing the glutathione redox cycle and enzymatic antioxidants.

Efficacy of a Cell-Based Influenza Vaccine in Children

Source: Nolan T, Fortanier AC, Leav B, et al. Efficacy of a cell-culture-derived quadrivalent influenza vaccine in children. N Engl J Med. 2021;385(16):1485-1495; doi:10.1056/NEJMoa2024848Investigators from multiple institutions conducted a randomized controlled trial to assess the efficacy of a cell-culture-derived quadrivalent inactivated influenza vaccine (IIV4c). Children ages 2 to <18 years from 8 countries: Australia, the Philippines, Thailand, Estonia, Finland, Lithuania, Poland, and Spain, were enrolled from May 25, 2017 to November 5, 2018 and followed during a total of 3 influenza seasons. At enrollment, participants were randomized to receive IIV4c, or a noninfluenza vaccine (meningococcal ACWY [Groups A, C, W-135, and Y] vaccine) as a control. IIV4c was derived from virus grown on Madin-Darby canine kidney cell lines and included 15 µg of hemagglutinin for 2 influenza A subtypes (H1N1 and H3N2) and 2 influenza B lineages (Yamagata and Victoria) per 0.5 mL dose. Parents of participants were contacted weekly and asked about symptoms consistent with influenza-like illness in their child (temperature ≥37.8°C and at least 1 of the following: cough, sore throat, nasal congestion, or rhinorrhea). A nasal swab was obtained on those with influenza-like illness and tested for influenza by PCR and culture. The primary outcome was first occurrence of influenza, confirmed by PCR and/or culture, occurring >14 days after the last vaccination until the end of the influenza season. Secondary outcomes included occurrence of specific influenza subtypes. Cox proportional-hazards models were used to compare occurrence of influenza in those randomized to IIV4c or the control vaccine; age, country, influenza season, and influenza vaccination history were included in the models. Vaccine efficacy was estimated as 1 minus the hazard ratio.A total of 4,514 participants with a mean age of 8.8 ± 4.1 years were enrolled; 50.7% were <9 years old. Among these children, 65.9% were previously vaccinated against influenza. Outcome data were analyzed on 4,509 participants. Overall, a total of 2,186 influenza-like illnesses were reported in 1,576 participants. Nasal swabs for PCR and culture were obtained during 97.4% of these illnesses, and first occurrence of influenza was confirmed in 539 participants, including 231 cases of influenza B (42.9%), 162 cases of influenza A/H3N2 (30.1%), and 126 of influenza A/H1N1 (23.4%). Among those randomized to IIV4c, influenza occurred in 175 of 2,257 participants (7.8%) vs 364 of 2,252 (16.2%) of those randomized to meningococcal ACWY. Overall efficacy of IIV4c was estimated at 54.6% (95% CI, 45.7, 62.1), 58.7% (95% CI, 47.5, 67.5) in children previously vaccinated, and 48.4% (95% CI, 32.1, 60.8) in those previously unvaccinated. Efficacy against A/H1N1, A/H3N2, and type B were 80.7% (95% CI, 69.2, 87.9), 42.1% (95% CI, 20.3, 57.9) and 47.6% (95% CI, 31.4, 60.0), respectively.The authors conclude that IIV4c was effective in preventing influenza.Dr Brady has disclosed no financial relationship relevant to this commentary. This commentary does not contain a discussion of an unapproved/investigative use of a commercial product/device.Most pediatric influenza vaccines in the US are manufactured using virus strains grown in eggs (egg-based).1 During growth in eggs, an influenza virus may undergo mutations in the globular head of the hemagglutinin protein, the major epitope.2 Antibodies to the hemagglutinin elicited by egg-based vaccine strains may fail to recognize the hemagglutinin of wild-type influenza strains, even when the vaccine strains and circulating strains are well-matched.3 This has led to low influenza vaccine effectiveness, especially of the H3N2 vaccine strain, in recent seasons.2 Another disadvantage of egg-based influenza vaccines is the long response time to manufacture vaccines when a new influenza virus emerges.4The IIV4c vaccine has been available for adults and children ≥4 years old since 2016.5 In March 2021, approval was extended to children ≥2 years old based on efficacy data from the current study. In October 2021, approval was further extended to infants ≥6 months based on data from a phase 3 randomized controlled study of children aged 6-47 months.6,5Much of the world is still in the throes of a coronavirus pandemic.7 Influenza also has the potential to cause pandemics, which are difficult to predict.1 Newer vaccine platforms (eg, mRNA vaccines as used in SARS-CoV-2 vaccine development) may offer additional protection against influenza.7Cell-culture-derived influenza vaccines have been approved for children ≥6 months. They are safe and effective in preventing influenza in healthy children. (See AAP Grand Rounds. 2022;47[1]:3).8

Identification and differential expression of microRNAs in Madin-Darby canine kidney cells with high and low tumorigenicities.

Madin-Darby canine kidney (MDCK) cells are widely used for vaccine production, however, the safety of MDCK cells needs to be considered seriously because of high tumorigenicity. Micro RNAs (miRNAs) that are involved in the tumorigenicity of MDCK cells have been never been reported. To reveal the role of miRNA in the tumorigenic phenotype of MDCK cell line. The miRNA expression profiles of two monoclonal MDCK cells (M09CL and M35CL) with low tumorigenicity and one MDCK cell line (M73P) with high tumorigenicity were characterized and investigated by using small RNA-seq technology. A total of 5 known miRNAs and 5 novel miRNAs were highly expressed in M73P. In addition, 4 known miRNAs and 4 novel miRNAs were highly expressed in M09CL and M35CL. The target genes of the differentially expressed miRNAs were significantly enriched in several biological processes, and the majority of these genes were involved in pathways in cancer and the MAPK signaling pathway. Through interaction analysis, 4 up-regulated miRNAs (cfa-miR-452, cfa-miR-8826, cfa-miR-224, and cfa-miR-2387) and their crucial target genes related to the tumor regulation network were identified. Results indicated these 4 miRNAs might play crucial roles in the tumorigenesis of MDCK cells. Our findings, which were based on the functional prediction of miRNAs and target genes, suggested that miRNAs might influence the tumorigenicity of MDCK cells by regulating target genes. Moreover, the results provided important data for understanding the miRNA-mediated regulatory networks that control the tumorigenicities of MDCK cells.

Combined ataxia telangiectasia mutated and DNA-dependent protein kinase inhibition radiosensitizes Madin-Darby canine kidney cells.

Uncovering radiation toxicity is critical for the adaptation and expansion of advanced radiation therapies and for the development of novel cancer radiotherapy. In the near future, advanced radiotherapies, including heavy ion beam treatment, are expected to be applied in the treatment of dogs, but further basic research on the effects of radiation using canine normal and cancer cells is necessary to actually apply these techniques and achieve high therapeutic efficacy. The radiation sensitivity is varied by the activities of DNA damage response (DDR) and DNA repair. The development of radiosensitizers that target DDR- and DNA repair-kinases, like ataxia telangiectasia mutated (ATM) and DNA-dependent protein kinase (DNA-PK), is progressing and is expected to be introduced into canine radiotherapy. However, there are no cytotoxicity reports on using the combination of radiation and these sensitizers as treatment in canine cells. In this study, we examined the cytotoxic effects of X-rays and/or radiosensitizers on the Madin-Darby canine kidney (MDCK) cell line. Our results show that X-rays suppress MDCK cell colony formation and proliferation in a dose-dependent manner. Additionally, our observations imply that the combination treatment with ATM inhibitor KU-55933 and DNA-PK inhibitor NU7441 significantly increased X-ray cytotoxicity in MDCK cells compared with the drugs alone. Furthermore, our findings further suggest that MDCK cells might be useful in clarifying the cytotoxicity in canine epithelial cells due to radiation and/or radiosensitizers, such as molecule-targeted drugs.

Isolation of MDCK cells with low expression of mdr1 gene and their use in membrane permeability screening.

The Madin-Darby canine kidney (MDCK) cell line is frequently used for permeability screening in drug discovery. It contains endogenous transporters, most prominently canine multidrug resistance P-glycoprotein (Mdr1), which can interfere with studies of P-glycoprotein substrate assessment and permeability measurements. Because MDCK wild type (WT) is genetically heterogeneous, an isolation procedure was investigated in this study to obtain the subclonal line with low P-glycoprotein expression. The best clone obtained had up to 3-fold lower amprenavir efflux and P-glycoprotein expression in comparison to WT. Of 12 standard compounds tested that exhibited active efflux in WT cells, 11 showed a decrease in efflux in the isolated clone. However, the decrease was not below the cut-off value of 2, indicating residual P--glycoprotein activity. Clone isolation via the limiting dilution method, combined with bidirectional amprenavir permeability for clone selection, successfully identified MDCK clones with substantially lower P-glycoprotein efflux and has been demonstrated as a useful tool for assessing passive permeability in early drug discovery.

In vitro screening of novel anti-Babesia gibsoni drugs from natural products.

Babesia gibsoni is a tick-transmitted intraerythrocytic apicomplexan parasite that causes babesiosis in dogs. Due to the strong side effects and lack of efficacy of current drugs, novel drugs against B. gibsoni are urgently needed. Natural products as a source for new drugs is a good choice for screening drugs against B. gibsoni. The current study focuses on identifying novel potential drugs from natural products against B. gibsoniin vitro. Parasite inhibition was verified using a SYBR green I-based fluorescence assay. A total of 502 natural product compounds were screened for anti-B. gibsoni activity in vitro. Twenty-four compounds showed high growth inhibition (>80%) on B. gibsoni and 5 plant-derived compounds were selected for further study. The half-maximal inhibitory concentration (IC50) values of lycorine (LY), vincristine sulfate (VS), emetine·2HCl (EME), harringtonine (HT) and cephaeline·HBr (CEP) were 784.4±3.3, 643.0±2.8, 253.1±1.4, 23.4±1.2, and 108.1±4.3nM, respectively. The Madin-Darby canine kidney (MDCK) cell line was used to assess cytotoxicity of hit compounds. All compounds showed minimal toxicity to the MDCK cells. The effects of hit compounds combined with diminazene aceturate (DA) on B. gibsoni were further evaluated in vitro. VS, EME, HT or CEP combined with DA showed synergistic effects against B. gibsoni, whereas LY combined with DA showed an antagonistic effect against B. gibsoni. The results obtained in this study indicate that LY, VS, EME, HT and CEP are promising compounds for B. gibsoni treatment.

Comparative Susceptibility of Madin-Darby Canine Kidney (MDCK) Derived Cell Lines for Isolation of Swine Origin Influenza A Viruses from Different Clinical Specimens.

Madin–Darby canine kidney (MDCK) cells are commonly used for the isolation of mammalian influenza A viruses. The goal of this study was to compare the sensitivity and suitability of the original MDCK cell line in comparison with MDCK-derived cell lines, MDCK.2, MDCK SIAT-1 and MDCK-London for isolation of swine-origin influenza A viruses (IAV-S) from clinical specimens. One-hundred thirty clinical specimens collected from pigs in the form of nasal swabs, lung tissue and oral fluids that were positive by PCR for the presence of IAV-S RNA were inoculated in the cell cultures listed above. MDCK-SIAT1 cells yielded the highest proportion of positive IAV-S isolations from all specimen types. For nasal swabs, 58.62% of the specimens were IAV-S positive in MDCK-SIAT1 cells, followed by MDCK-London (36.21%), and conventional MDCK and MDCK.2 cells (27.5%). For lung specimens, 59.38% were IAV-S positive in MDCK-SIAT1 cells, followed by MDCK-London (40.63%), and conventional MDCK and MDCK.2 cells (18.75–31.25%). Oral fluids yielded the lowest number of positive virus isolation results, but MDCK-SIAT1 cells were still had the highest rate (35%) of IAV-S isolation, whereas the isolation rate in other cells ranged from 5–7.5%. Samples with lower IAV-S PCR cycle threshold (Ct) values were more suitable for culturing and isolation. The isolated IAV-S represented H1N1-β, H1N2-α, H1N1pdm and H3N2 cluster IV and cluster IVB viruses. The result of the current study demonstrated the importance of using the most appropriate MDCK cells when isolating IAV-S from clinical samples.

Efficacy of a Cell-Culture–Derived Quadrivalent Influenza Vaccine in Children

BackgroundCell-culture–derived influenza vaccines may enable a closer antigenic match to circulating strains of influenza virus by avoiding egg-adapted mutations.MethodsWe evaluated the efficacy of a cell-culture–derived quadrivalent inactivated influenza vaccine (IIV4c) using a Madin–Darby canine kidney cell line in children and adolescents 2 to less than 18 years of age. During three influenza seasons, participants from eight countries were enrolled in an observer-blinded, randomized clinical trial comparing IIV4c with a noninfluenza vaccine (meningococcal ACWY). All the participants received a dose of a trial vaccine. Children 2 to less than 9 years of age without previous influenza vaccination who were assigned to the IIV4c group received a second dose on day 29; their counterparts who were assigned to the comparator group received placebo. Participants were followed for at least 180 days for efficacy and safety. The presence of influenza virus in nasopharyngeal swabs from participants with influenza-like illness was confirmed by reverse-transcriptase–polymerase-chain-reaction assay and viral culture. A Cox proportional-hazards model was used to evaluate the efficacy of IIV4c as measured by the first occurrence of laboratory-confirmed type A or B influenza (primary end point).ResultsBetween 2017 and 2019, a total of 4514 participants were randomly assigned to receive IIV4c or the meningococcal ACWY vaccine. Laboratory-confirmed influenza occurred in 175 of 2257 participants (7.8%) in the IIV4c group and in 364 of 2252 participants (16.2%) in the comparator group, and the efficacy of IIV4c was 54.6% (95% confidence interval [CI], 45.7 to 62.1). Efficacy was 80.7% (95% CI, 69.2 to 87.9) against influenza A/H1N1, 42.1% (95% CI, 20.3 to 57.9) against influenza A/H3N2, and 47.6% (95% CI, 31.4 to 60.0) against influenza B. IIV4c showed consistent vaccine efficacy in subgroups according to age, sex, race, and previous influenza vaccination. The incidences of adverse events were similar in the IIV4c group and the comparator group.ConclusionsIIV4c provided protection against influenza in healthy children and adolescents across seasons, regardless of previous influenza vaccination. (Funded by Seqirus; EudraCT number, 2016-002883-15; ClinicalTrials.gov number, NCT03165617.)

Comprehensive N-glycosylation analysis of the influenza A virus proteins HA and NA from adherent and suspension MDCK cells.

Glycosylation is considered as a critical quality attribute for the production of recombinant biopharmaceuticals such as hormones, blood clotting factors, or monoclonal antibodies. In contrast, glycan patterns of immunogenic viral proteins, which differ significantly between the various expression systems, are hardly analyzed yet. The influenza A virus (IAV) proteins hemagglutinin (HA) and neuraminidase (NA) have multiple N-glycosylation sites, and alteration of N-glycan micro- and macroheterogeneity can have strong effects on virulence and immunogenicity. Here, we present a versatile and powerful glycoanalytical workflow that enables a comprehensive N-glycosylation analysis of IAV glycoproteins. We challenged our workflow with IAV (A/PR/8/34 H1N1) propagated in two closely related Madin-Darby canine kidney (MDCK) cell lines, namely an adherent MDCK cell line and its corresponding suspension cell line. As expected, N-glycan patterns of HA and NA from virus particles produced in both MDCK cell lines were similar. Detailed analysis of the HA N-glycan microheterogeneity showed an increasing variability and a higher complexity for N-glycosylation sites located closer to the head region of the molecule. In contrast, NA was found to be exclusively N-glycosylated at site N73. Almost all N-glycan structures were fucosylated. Furthermore, HA and NA N-glycan structures were exclusively hybrid- and complex-type structures, to some extent terminated with alpha-linked galactose(s) but also with blood group H type 2 and blood group A epitopes. In contrast to the similarity of the overall glycan pattern, differences in the relative abundance of individual structures were identified. This concerned, in particular, oligomannose-type, alpha-linked galactose, and multiantennary complex-type N-glycans.

Imidazole-2-carboxaldehyde Chitosan Thiosemicarbazones and their Copper(II) Complexes: Synthesis, Characterization and Antitumorigenic Activity against Madin-Darby Canine Kidney Cell Line

Chitosan oligosaccharide and high molecular weight crab shell chitosan were functionalized as imidazole-2-carboxaldehyde chitosan thiosemicarbazones and their copper(II) complexes were synthesized. The synthesized compounds were characterized by FT-IR, 13C NMR, EPR spectroscopy, powder X-ray diffraction (PXRD) analysis, elemental analysis and magnetic susceptibility measurements. The low molecular weight chitosan thiosemicarbazones showed higher in vitro inhibitory activity as studied by MTT assay against the tumorigenic epithelial Madin-Darby Canine Kidney (MDCK) cell line than the corresponding high molecular weight chitosan derivative. The antitumorigenic enhancement upon the complex formation was revealed by the better inhibitory activity of copper(II) chitosan thiosemicarbazone chelates.

Metabolic Profiles in Madin-Darby Canine Kidney Cell Lines Infected with H3N2 Canine Influenza Viruses.

Virus replication and host cell growth require host cell metabolic networks to provide energy and precursors for the synthesis of macromolecules. The aim of this study was to investigate the most direct changes in energy metabolism and small-molecule metabolism of Madin-Darby canine kidney (MDCK) cells infected with H3N2 canine influenza virus (CIV) and to determine whether small metabolites contribute to the pathogenesis of CIV. To study the metabolomics of MDCK cells infected with H3N2 CIV, we used liquid chromatography-tandem mass spectrometry combined with multivariate statistical analysis. The results showed that 798 positive ions were detected, among which 33 were upregulated and 11 were downregulated, and 406 negative ions were detected, among which 33 were upregulated and 9 were downregulated. Through Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, we found that these differentially expressed molecules were mainly concentrated in the steroid hormone biosynthesis, amino sugar and nucleotide sugar metabolism, sphingolipid metabolism, vitamin B6 metabolism, cysteine and methionine metabolism, vitamin digestion and absorption, arginine and proline metabolism, biosynthesis of amino acids, and folate biosynthesis metabolic pathways. These pathways are involved in energy metabolism and nucleic acid and protein synthesis, which are essential for virus replication. Our experimental data suggest that H3N2 CIV infection reconstitutes/influences cellular metabolic processes, which in turn may contribute to viral replication. These findings are important for the development of enzyme inhibitors or metabolites for the identification of antiviral drugs. In addition, understanding the metabolic interaction between CIV and host cells is also very important for the complex pathogenicity of CIV, providing certain guidance for the treatment of canine influenza.

Establishment of a low-tumorigenic MDCK cell line and study of differential molecular networks

Influenza is an acute respiratory infection caused by the influenza virus, and vaccination against influenza is considered the best way to prevent the onset and spread. MDCK (Madin-Darby canine kidney) cells are typically used to isolate the influenza virus, however, their high tumorigenicity is the main controversy in the production of influenza vaccines. Here, MDCK-C09 and MDCK-C35 monoclonal cell lines were established, which were proven to be low in tumorigenicity. RNA-seq of MDCK-C09, MDCK-C35, and MDCK-W73 cells was performed to investigate the putative tumorigenicity mechanisms. Tumor-related molecular interaction analysis of the differentially expressed genes indicates that hub genes, such as CUL3 and EGFR, may play essential roles in tumorigenicity differences between MDCK-C (MDCK-C09 and MDCK-C35) and MDCK-W (MDCK-W73) cells. Moreover, the analysis of cell proliferation regulation-associated molecular interaction shows that downregulated JUN and MYC, for instance, mediate increased proliferation of these cells. The present study provides a new low-tumorigenic MDCK cell line and describes the potential molecular mechanism for the low tumorigenicity and high proliferation rate.

In Vitro Nephrotoxicity Induced by Herb-Herb Interaction between Radix Glycyrrhizae and Radix Euphorbiae Pekinensis.

Radix Glycyrrhizae (RG)-Radix Euphorbiae Pekinensis (REP) is a representative incompatible herbal pair of Eighteen Incompatible Medicaments (EIM) and has been disputed in clinical application for a long time. The present study was performed with the Madin-Darby canine kidney (MDCK) cell line using cell cytotoxicity assay, apoptosis detection, cell cycle measurement, reactive oxygen species (ROS) determination, and high content analysis (HCA) in combination with high-performance liquid chromatography (HPLC) fingerprint comparison to clarify whether RG and REP can be concomitantly used from the perspective of cytotoxicity, investigate the major correlated compounds, and elucidate the underlying mechanisms. The results showed that the toxicity of REP could be significantly enhanced through its concomitant use with RG in the ratio of 1 : 1, and this increased toxicity could be weakened with the further increased proportion of RG. 3,3′-di-O-methylellagic acid-4′-O-β-D-xylopyranoside (DEAX) and 3,3′-di-O-methylellagic acid (DEA) were shown to be mainly responsible for the toxicity induced by concomitant use of REP and RG. Both RG-REP decoctions and the above two compounds boosted cell apoptosis, cellular morphological change, ROS accumulation, and mitochondrial membrane potential (MMP) disruption. In conclusion, the incompatible use of RG and REP is conditionally established because of the bidirectional regulatory effect of RG, and the major compounds responsible for RG-REP incompatibility are DEAX and DEA, which result in toxicity through activation of mitochondria-dependent apoptosis induced by increased ROS production. This study provided a basis for understanding the incompatible use of RG and REP and the EIM theory.

Protective Effect of Hydroxytyrosol Against Oxidative Stress Induced by the Ochratoxin in Kidney Cells: in vitro and in vivo Study.

Ochratoxin-A (OTA) is a mycotoxin that is a common contaminant of food products for both humans and animals. This mycotoxin has several toxic effects. In particular, ochratoxin has significant nephrotoxic potential. In fact, OTA has been described as being responsible for naturally occurring animal and human kidney disorders. The toxicity of this mycotoxin involves the induction of the oxidative stress pathways. Therefore, in the present study, we wanted to evaluate the potential protective effects of hydroxytyrosol (HT), a phenolic constituent with potent antioxidant activity, of extra virgin olive oil in three different renal cell lines, the Madin-Darby canine kidney cell line (MDCK), a pig kidney cell line (LLC-PK1), and a rabbit kidney cell line (RK 13), and in rats. Our results clearly showed that renal cells respond to OTA exposure by reducing cell proliferation and the induction of oxidative stress. Pre-incubation of the cells with HT prevented the cellular cytotoxicity and increased reactive oxygen species (ROS) levels induced by OTA. In addition, the antioxidative activity of HT was studied by measuring malondialdehyde (MDA) and lactate dehydrogenase (LDH) levels and nitrosative stress. Finally, we investigated the capability of HT (20 mg/kg, intraperitoneally) to act in vivo. In rats, HT reduced oxidative stress and collagen accumulation in the kidney and counteracted the augmentations in AST, ALT, and creatinine levels following OTA induction (250 μg/kg for 90 days orally). In conclusion, our findings demonstrate that HT is able to protect three renal cell lines from the damage induced by OTA and protect the kidneys of rats. Therefore, the use of this compound could be an important strategy for the treatment and prevention of this type of kidney dysfunction.

Characterization and Prospective Applications of the Exopolysaccharides Produced by Rhodosporidium babjevae.

Purpose: Due to the potential industrial and therapeutic applications of the yeast exopolysaccharides (EPSs), there has been an increasing demand to assess these biopolymers with improved characteristics. This study aimed to characterize the EPSs from Rhodosporidium babjevae (ATCC 90942 and IBRC-M 30088) as well as to evaluate their possible antioxidant, emulsifying and antiproliferative activities. Methods: Rhodosporidium babjevae was cultured for 5 days and following isolation of supernatant, EPSs precipitated with adding of cold absolute ethanol and freeze-dried. The EPSs chemical structure was determined by FT-IR, SEM, HPLC-SEC and GC-MS. Additionally the solubility, water holding capacity and emulsifying activity of EPSs were evaluated. In vitro, antioxidant activity was investigated against DPPH, superoxide and hydroxyl radicals. Finally the EPSs consequence on the cell proliferation of human breast adenocarcinoma (MCF-7) and Madin-Darby canine kidney (MDCK) cell lines was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test. Results: R. babjevae excreted 1.6±0.2 g/L of the EPSs. The EPSs had three fractions with molecular weights of 1.02 ×106 , 5×105 and 2×105 Da. Mannose and glucose were found as the main monosaccharides of the EPSs (84:16 mol%, respectively). The EPSs exhibited emulsifying activity on sun flower oil. The scavenging activities were found to be dose-dependent and higher than hyaluronic acid. Significant difference among the EPSs treatments on the proliferation of MCF-7 and MDCK cell lines was not observed (P>0.05). Conclusion: These results show the interesting potential of the EPSs from R. babjevae as biocompatible compounds for using in food and pharmaceutical fields.