Fungal-Induced Cell Cycle Impairment, Chromosome Instability and Apoptosis via Differential Activation of NF-κB

PubMed Central

Ben-Abdallah, Mariem; Sturny-Leclère, Aude; Avé, Patrick; Louise, Anne; Moyrand, Frédérique; Weih, Falk; Janbon, Guilhem; Mémet, Sylvie

2012-01-01

Microbial pathogens have developed efficient strategies to compromise host immune responses. Cryptococcus neoformans is a facultative intracellular pathogen, recognised as the most common cause of systemic fungal infections leading to severe meningoencephalitis, mainly in immunocompromised patients. This yeast is characterized by a polysaccharide capsule, which inhibits its phagocytosis. Whereas phagocytosis escape and macrophage intracellular survival have been intensively studied, extracellular survival of this yeast and restraint of host innate immune response are still poorly understood. In this study, we have investigated whether C. neoformans affected macrophage cell viability and whether NF-κB (nuclear factor-κB), a key regulator of cell growth, apoptosis and inflammation, was involved. Using wild-type (WT) as well as mutant strains of C. neoformans for the pathogen side, and WT and mutant cell lines with altered NF-κB activity or signalling as well as primary macrophages for the host side, we show that C. neoformans manipulated NF-κB-mediated signalling in a unique way to regulate macrophage cell fate and viability. On the one hand, serotype A strains reduced macrophage proliferation in a capsule-independent fashion. This growth decrease, which required a critical dosage of NF-κB activity, was caused by cell cycle disruption and aneuploidy, relying on fungal-induced modification of expression of several cell cycle checkpoint regulators in S and G2/M phases. On the other hand, C. neoformans infection induced macrophage apoptosis in a capsule-dependent manner with a differential requirement of the classical and alternative NF-κB signalling pathways, the latter one being essential. Together, these findings shed new light on fungal strategies to subvert host response through uncoupling of NF-κB activity in pathogen-controlled apoptosis and impairment of cell cycle progression. They also provide the first demonstration of induction of aneuploidy by a fungal pathogen, which may have wider implications for human health as aneuploidy is proposed to promote tumourigenesis. PMID:22396644

Fungal-induced cell cycle impairment, chromosome instability and apoptosis via differential activation of NF-κB.

PubMed

Ben-Abdallah, Mariem; Sturny-Leclère, Aude; Avé, Patrick; Louise, Anne; Moyrand, Frédérique; Weih, Falk; Janbon, Guilhem; Mémet, Sylvie

2012-01-01

Microbial pathogens have developed efficient strategies to compromise host immune responses. Cryptococcus neoformans is a facultative intracellular pathogen, recognised as the most common cause of systemic fungal infections leading to severe meningoencephalitis, mainly in immunocompromised patients. This yeast is characterized by a polysaccharide capsule, which inhibits its phagocytosis. Whereas phagocytosis escape and macrophage intracellular survival have been intensively studied, extracellular survival of this yeast and restraint of host innate immune response are still poorly understood. In this study, we have investigated whether C. neoformans affected macrophage cell viability and whether NF-κB (nuclear factor-κB), a key regulator of cell growth, apoptosis and inflammation, was involved. Using wild-type (WT) as well as mutant strains of C. neoformans for the pathogen side, and WT and mutant cell lines with altered NF-κB activity or signalling as well as primary macrophages for the host side, we show that C. neoformans manipulated NF-κB-mediated signalling in a unique way to regulate macrophage cell fate and viability. On the one hand, serotype A strains reduced macrophage proliferation in a capsule-independent fashion. This growth decrease, which required a critical dosage of NF-κB activity, was caused by cell cycle disruption and aneuploidy, relying on fungal-induced modification of expression of several cell cycle checkpoint regulators in S and G2/M phases. On the other hand, C. neoformans infection induced macrophage apoptosis in a capsule-dependent manner with a differential requirement of the classical and alternative NF-κB signalling pathways, the latter one being essential. Together, these findings shed new light on fungal strategies to subvert host response through uncoupling of NF-κB activity in pathogen-controlled apoptosis and impairment of cell cycle progression. They also provide the first demonstration of induction of aneuploidy by a fungal pathogen, which may have wider implications for human health as aneuploidy is proposed to promote tumourigenesis.

Optimizing eukaryotic cell hosts for protein production through systems biotechnology and genome-scale modeling.

PubMed

Gutierrez, Jahir M; Lewis, Nathan E

2015-07-01

Eukaryotic cell lines, including Chinese hamster ovary cells, yeast, and insect cells, are invaluable hosts for the production of many recombinant proteins. With the advent of genomic resources, one can now leverage genome-scale computational modeling of cellular pathways to rationally engineer eukaryotic host cells. Genome-scale models of metabolism include all known biochemical reactions occurring in a specific cell. By describing these mathematically and using tools such as flux balance analysis, the models can simulate cell physiology and provide targets for cell engineering that could lead to enhanced cell viability, titer, and productivity. Here we review examples in which metabolic models in eukaryotic cell cultures have been used to rationally select targets for genetic modification, improve cellular metabolic capabilities, design media supplementation, and interpret high-throughput omics data. As more comprehensive models of metabolism and other cellular processes are developed for eukaryotic cell culture, these will enable further exciting developments in cell line engineering, thus accelerating recombinant protein production and biotechnology in the years to come. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A Bovine Lymphosarcoma Cell Line Infected with Theileria annulata Exhibits an Irreversible Reconfiguration of Host Cell Gene Expression

PubMed Central

Durrani, Zeeshan; Pillai, Sreerekha S.; Baird, Margaret; Shiels, Brian R.

2013-01-01

Theileria annulata, an intracellular parasite of bovine lymphoid cells, induces substantial phenotypic alterations to its host cell including continuous proliferation, cytoskeletal changes and resistance to apoptosis. While parasite induced modulation of host cell signal transduction pathways and NFκB activation are established, there remains considerable speculation on the complexities of the parasite directed control mechanisms that govern these radical changes to the host cell. Our objectives in this study were to provide a comprehensive analysis of the global changes to host cell gene expression with emphasis on those that result from direct intervention by the parasite. By using comparative microarray analysis of an uninfected bovine cell line and its Theileria infected counterpart, in conjunction with use of the specific parasitacidal agent, buparvaquone, we have identified a large number of host cell gene expression changes that result from parasite infection. Our results indicate that the viable parasite can irreversibly modify the transformed phenotype of a bovine cell line. Fifty percent of genes with altered expression failed to show a reversible response to parasite death, a possible contributing factor to initiation of host cell apoptosis. The genes that did show an early predicted response to loss of parasite viability highlighted a sub-group of genes that are likely to be under direct control by parasite infection. Network and pathway analysis demonstrated that this sub-group is significantly enriched for genes involved in regulation of chromatin modification and gene expression. The results provide evidence that the Theileria parasite has the regulatory capacity to generate widespread change to host cell gene expression in a complex and largely irreversible manner. PMID:23840536

Viral infection and human disease - insights from minimotifs

PubMed Central

Kadaveru, Krishna; Vyas, Jay; Schiller, Martin R.

2008-01-01

Short functional peptide motifs cooperate in many molecular functions including protein interactions, protein trafficking, and posttranslational modifications. Viruses exploit these motifs as a principal mechanism for hijacking cells and many motifs are necessary for the viral life-cycle. A virus can accommodate many short motifs in its small genome size providing a plethora of ways for the virus to acquire host molecular machinery. Host enzymes that act on motifs such as kinases, proteases, and lipidation enzymes, as well as protein interaction domains, are commonly mutated in human disease, suggesting that the short peptide motif targets of these enzymes may also be mutated in disease; however, this is not observed. How can we explain why viruses have evolved to be so dependent on motifs, yet these motifs, in general do not seem to be as necessary for human viability? We propose that short motifs are used at the system level. This system architecture allows viruses to exploit a motif, whereas the viability of the host is not affected by mutation of a single motif. PMID:18508672

Excretory products of the cestode, Schistocephalus solidus, modulate in vitro responses of leukocytes from its specific host, the three-spined stickleback (Gasterosteus aculeatus).

PubMed

Scharsack, Jörn Peter; Gossens, Anabel; Franke, Frederik; Kurtz, Joachim

2013-12-01

Helminth parasites have evolved remarkable strategies to manipulate the immune system of their hosts. During infections of three-spined stickleback (Gasterosteus aculeatus) with the cestode Schistocephalus solidus prominent immunological changes occur, presumably due to manipulative activity of the parasite. We hypothesise that excretory/secretory products of the parasite are involved in the manipulation of the stickleback's immune system and that this may depend on the individual parasite and its origin. We therefore produced S. solidus conditioned cell culture media (SSCM) with parasites from different origins (Norway, Spain and Germany) and exposed head kidney leukocytes (HKL) from un-infected sticklebacks in cell cultures to SSCM. After in vitro culture, HKL were subjected to differential cell counts (granulocytes/lymphocytes) by means of flow cytometry. Leukocyte sub-populations were analysed for cell viability and changes in cell morphology. The respiratory burst activity was measured with a luminescence assay. Exposure of HKL to SSCM induced an up-regulation of respiratory burst activity after already 1 h, which was still elevated at 24 h, but which was in some cases significantly down-regulated after 96 h. Respiratory burst was positively correlated with the number of live granulocytes in the culture, suggesting that the respiratory burst activity was changed by SSCM effects on granulocyte viability. After 1 h and 24 h of HKL culture, no lymphocyte responses to SSCM were detectable, but after 96 h lymphocyte viability was significantly decreased with SSCM from Spanish S. solidus. In these cultures, residual lymphocytes increased in size, suggesting that cell death and activation might have occurred in parallel. The highest respiratory burst activity was induced by SSCM from Spanish parasites, in particular when they were grown in sympatric sticklebacks. The in vitro HKL responses to SSCM depended on the individual parasite and its population of origin, suggesting that in vivo, S. solidus excretory products are regulated individually, possibly to balance the interplay of each individual host-parasite pair. Copyright © 2013 Elsevier Ltd. All rights reserved.

In vitro effect of phototherapy with low-intensity laser on HSV-1 and epithelial cells

NASA Astrophysics Data System (ADS)

Eduardo, Fernanda P.; Mehnert, Dolores U.; Monezi, Telma A.; Zezell, Denise M.; Schubert, Mark M.; Eduardo, Carlos P.; Marques, Márcia M.

2007-02-01

The effects of phototherapy on herpes lesions have been clinically demonstrated by either preventing the lesion formation or speeding their repair. The aim of this in vitro study was analyze the effect of phototherapy on epithelial cells and HSV-1 in culture. Cultures of HSV-1 and epithelial cells (Vero cell line) were used. The irradiations were done using a GaAlAs laser (660 e 780 nm, 4.0 mm2). One, two and three irradiations with 6 h-intervals were done. The experimental groups were: Control: non-irradiated; 660 nm and 3 J/cm2 (2.8 sec); 660 nm and 5 J/cm2 (3.8 sec); 780 nm and 3 J/cm2 (1.9 sec), and 780 nm and 5 J/cm2 (2.5 sec). The HSV-1 cytopatic effect and the cell viability of irradiated cultures and controls were analyzed in four different conditions: irradiation of non-infected epithelial cells; epithelial cells irradiated prior infection; virus irradiated prior infection; irradiation of HSV infected cells. The mitochondrial activity and cytopathic effects were assessed. The number of irradiations influenced the cell growth positively and proportionally, except for the 660 nm/ 3 J/cm2 group. Any variation in cytopathic effects was observed amongst the experimental groups. The viability of infected cells prior irradiation was significantly higher than that of non-irradiated cultures when 2 irradiations were done. Under the experimental conditions of this study we concluded that phototherapy is capable of enhancing epithelial cell growth and prolonging cell viability of HSV-1 infected cells. Positive benefits of phototherapy could be resultant from prolongation of infected cells viability, corroborating with host defenses.

Plasmepsin V licenses Plasmodium proteins for export into the host erythrocyte.

PubMed

Russo, Ilaria; Babbitt, Shalon; Muralidharan, Vasant; Butler, Tamira; Oksman, Anna; Goldberg, Daniel E

2010-02-04

During their intraerythrocytic development, malaria parasites export hundreds of proteins to remodel their host cell. Nutrient acquisition, cytoadherence and antigenic variation are among the key virulence functions effected by this erythrocyte takeover. Proteins destined for export are synthesized in the endoplasmic reticulum (ER) and cleaved at a conserved (PEXEL) motif, which allows translocation into the host cell via an ATP-driven translocon called the PTEX complex. We report that plasmepsin V, an ER aspartic protease with distant homology to the mammalian processing enzyme BACE, recognizes the PEXEL motif and cleaves it at the correct site. This enzyme is essential for parasite viability and ER residence is essential for its function. We propose that plasmepsin V is the PEXEL protease and is an attractive enzyme for antimalarial drug development.

Preservation of Rhizobium viability and symbiotic infectivity by suspension in water

DOE Office of Scientific and Technical Information (OSTI.GOV)

Crist, D.K.; Wyza, R.E.; Mills, K.K.

1984-05-01

Three Rhizobium japonicum strains and two slow-growing cowpea-type Rhizobium strains were found to remain viable and able to rapidly nodulate their respective hosts after being stored in purified water at ambient temperatures for periods of 1 year and longer. Three fast-growing Rhizobium species did not remain viable under the same water storage conditions. After dilution of slow-growing Rhizobium strains with water to 10/sup 3/ to 10/sup 5/ cells ml/sup -1/, the bacteria multiplied until the viable cell count reached levels of between 10/sub 6/ and 10/sup 7/ cells ml/sup -1/. The viable cell count subsequently remained fairly constant. When themore » rhizobia were diluted to 10/sup 7/ cells ml/sup -1/, they did not multiply, but full viability was maintained. If the rhizobia were washed and suspended at 10/sup 9/ cells ml/sup -1/, viability slowly declined to 10/sup 7/ cells ml/sup -1/ during 9 months of storage. Scanning electron microscopy showed that no major morphological changes took place during storage. Preservation of slow-growing rhizobia in water suspensions could provide a simple and inexpensive alternative to current methods for the preservation of rhizobia for legume inoculation. 25 references, 7 figures, 2 tables.« less

Isolation, characterization and recombinant protein expression in Veggie-CHO: A serum-free CHO host cell line.

PubMed

Rasmussen, B; Davis, R; Thomas, J; Reddy, P

1998-11-01

The dihydrofolate reductase-deficient Chinese hamster ovary cell line, DXB11-CHO, commonly used as a host cell for the production of recombinant proteins requires 7.5% serum-supplementation for optimal growth. Regulatory issues surrounding the use of serum in clinical production processes and the direct and indirect costs of using serum in large-scale production and recovery processes have triggered efforts to derive serum-independent host cell lines. We have successfully isolated a serum-free host that we named Veggie- CHO. Veggie-CHO was generated by adapting DXB11-CHO cells to growth in serum-free media in the absence of exogenous growth factors such as Transferrin and Insulin-like growth factor, which we have previously shown to be essential for growth and viability of DXB11- CHO cells. Veggie-CHO cells have been shown to maintain an average doubling time of 22 hr in continuous growth cultures over a period of three months and have retained the dihydrofolate reductase -deficient phenotype of their parental DXB11-CHO cells. These properties and the stability of its serum-free phenotype have allowed the use of Veggie- CHO as host cells for transfection and amplified expression of recombinant proteins. We describe the derivation a serum-free recombinant cell line with an average doubling time of 20 hr and specific productivity of 2.5 Units recombinant Flt-3L protein per 10e6 cells per day.

Human Adipose-Derived Mesenchymal Stem Cells Cryopreservation and Thawing Decrease α4-Integrin Expression.

PubMed

Irioda, Ana Carolina; Cassilha, Rafael; Zocche, Larissa; Francisco, Julio Cesar; Cunha, Ricardo Correa; Ferreira, Priscila Elias; Guarita-Souza, Luiz Cesar; Ferreira, Reginaldo Justino; Mogharbel, Bassam Felipe; Garikipati, Venkata Naga Srikanth; Souza, Daiany; Beltrame, Mirian Perlingeiro; de Carvalho, Katherine Athayde Teixeira

2016-01-01

Aim. The effects of cryopreservation on adipose tissue-derived mesenchymal stem cells are not clearly documented, as there is a growing body of evidence about the importance of adipose-derived mesenchymal stem cells for regenerative therapies. The aim of this study was to analyze human adipose tissue-derived mesenchymal stem cells phenotypic expression (CD34, CD45, CD73, CD90, CD105, and CD49d), colony forming unit ability, viability, and differentiation potential before and after cryopreservation. Materials and Methods. 12 samples of the adipose tissue were collected from a healthy donor using the liposuction technique. The cell isolation was performed by enzymatic digestion and then the cells were cultured up to passage 2. Before and after cryopreservation the immunophenotype, cellular viability analysis by flow cytometer, colony forming units ability, differentiation potential into adipocytes and osteoblasts as demonstrated by Oil Red O and Alizarin Red staining, respectively. Results. The immunophenotypic markers expression was largely preserved, and their multipotency was maintained. However, after cryopreservation, the cells decreased α4-integrin expression (CD49d), cell viability, and number of colony forming units. Conclusions. These findings suggest that ADMSC transplanted after cryopreservation might compromise the retention of transplanted cells in the host tissue. Therefore, further studies are warranted to standardize protocols related to cryopreservation to attain full benefits of stem cell therapy.

In Vitro Effect of the Synthetic cal14.1a Conotoxin, Derived from Conus californicus, on the Human Parasite Toxoplasma gondii.

PubMed

De León-Nava, Marco A; Romero-Núñez, Eunice; Luna-Nophal, Angélica; Bernáldez-Sarabia, Johanna; Sánchez-Campos, Liliana N; Licea-Navarro, Alexei F; Morales-Montor, Jorge; Muñiz-Hernández, Saé

2016-04-08

Toxins that are secreted by cone snails are small peptides that are used to treat several diseases. However, their effects on parasites with human and veterinary significance are unknown. Toxoplasma gondii is an opportunistic parasite that affects approximately 30% of the world's population and can be lethal in immunologically compromised individuals. The conventional treatment for this parasitic infection has remained the same since the 1950s, and its efficacy is limited to the acute phase of infection. These findings have necessitated the search for new drugs that specifically target T. gondii. We examined the effects of the synthetic toxin cal14.1a (s-cal14.1a) from C. californicus on the tachyzoite form of T. gondii. Our results indicate that, at micromolar concentrations, s-cal14.1a lowers viability and inhibits host cell invasion (by 50% and 61%, respectively) on exposure to extracellular parasites. Further, intracellular replication decreased significantly while viability of the host cell was unaffected. Our study is the first report on the antiparasitic activity of a synthetic toxin of C. californicus.

Stretchable living materials and devices with hydrogel–elastomer hybrids hosting programmed cells

PubMed Central

Liu, Xinyue; Tang, Tzu-Chieh; Tham, Eléonore; Yuk, Hyunwoo; Lin, Shaoting; Lu, Timothy K.; Zhao, Xuanhe

2017-01-01

Living systems, such as bacteria, yeasts, and mammalian cells, can be genetically programmed with synthetic circuits that execute sensing, computing, memory, and response functions. Integrating these functional living components into materials and devices will provide powerful tools for scientific research and enable new technological applications. However, it has been a grand challenge to maintain the viability, functionality, and safety of living components in freestanding materials and devices, which frequently undergo deformations during applications. Here, we report the design of a set of living materials and devices based on stretchable, robust, and biocompatible hydrogel–elastomer hybrids that host various types of genetically engineered bacterial cells. The hydrogel provides sustainable supplies of water and nutrients, and the elastomer is air-permeable, maintaining long-term viability and functionality of the encapsulated cells. Communication between different bacterial strains and with the environment is achieved via diffusion of molecules in the hydrogel. The high stretchability and robustness of the hydrogel–elastomer hybrids prevent leakage of cells from the living materials and devices, even under large deformations. We show functions and applications of stretchable living sensors that are responsive to multiple chemicals in a variety of form factors, including skin patches and gloves-based sensors. We further develop a quantitative model that couples transportation of signaling molecules and cellular response to aid the design of future living materials and devices. PMID:28202725

Probiotic fermented sausage: viability of probiotic microorganisms and sensory characteristics.

PubMed

Rouhi, M; Sohrabvandi, S; Mortazavian, A M

2013-01-01

Probiotics are from functional foods that bring health benefits for humans. Nowadays, a major development in functional foods is related to food containing probiotic cultures, mainly lactic acid bacteria or bifidobacteria. Probiotics must be alive and ingested in sufficient amounts to exert the positive effects on the health and the well-being of the host. Therefore, viability of probiotic products (the minimum viable probiotic cells in each gram or milliliter of product till the time of consumption) is their most important characteristic. However, these organisms often show poor viability in fermented products due to their detrimental conditions. Today, the variety of fermented meat products available around the world is nearly equal to that of cheese. With meat products, raw fermented sausages could constitute an appropriate vehicle for such microorganisms into the human gastrointestinal tract. In present article, the viability of probiotic microorganisms in fermented sausage, the main factors affect their viability, and the sensorial characteristics of final product are discussed.

Trace detection of specific viable bacteria using tetracysteine-tagged bacteriophages.

PubMed

Wu, Lina; Luan, Tian; Yang, Xiaoting; Wang, Shuo; Zheng, Yan; Huang, Tianxun; Zhu, Shaobin; Yan, Xiaomei

2014-01-07

Advanced methods are urgently needed to determine the identity and viability of trace amounts of pathogenic bacteria in a short time. Existing approaches either fall short in the accurate assessment of microbial viability or lack specificity in bacterial identification. Bacteriophages (or phages for short) are viruses that exclusively infect bacterial host cells with high specificity. As phages infect and replicate only in living bacterial hosts, here we exploit the strategy of using tetracysteine (TC)-tagged phage in combination with biarsenical dye to the discriminative detection of viable target bacteria from dead target cells and other viable but nontarget bacterial cells. Using recombinant M13KE-TC phage and Escherichia coli ER2738 as a model system, distinct differentiation between individual viable target cells from dead target cells was demonstrated by flow cytometry and fluorescence microscopy. As few as 1% viable E. coli ER2738 can be accurately quantified in a mix with dead E. coli ER2738 by flow cytometry. With fluorescence microscopic measurement, specific detection of as rare as 1 cfu/mL original viable target bacteria was achieved in the presence of a large excess of dead target cells and other viable but nontarget bacterial cells in 40 mL artificially contaminated drinking water sample in less than 3 h. This TC-phage-FlAsH approach is sensitive, specific, rapid, and simple, and thus shows great potential in water safety monitoring, health surveillance, and clinical diagnosis of which trace detection and identification of viable bacterial pathogens is highly demanded.

Toxicity of anti-fouling biocides to encysted metacercariae of Echinoparyphium recurvatum (Digenea: Echinostomatidae) and their snail hosts.

PubMed

Morley, N J; Leung, K M Y; Morritt, D; Crane, M

2004-07-01

The toxicity of the anti-fouling biocides tributyltin (TBTO), copper, and Irgarol 1051 (irgarol) at a nominal concentration of 10 microg/l over a 30 day period were investigated against the viability of metacercarial cysts of the digenean parasite Echinoparyphium recurvatum resident within the body of two common freshwater snails, Lymnaea peregra and Physa fontinalis. Reduced parasite viability was found under most exposures in both snail species. However a greater effect of toxicant exposure was found in cysts within P. fontinalis compared to those in L. peregra. This was associated with an increased mortality of the host snail. Among all tested biocides, TBTO exposures induced the highest mortality to both the parasite and their hosts. These results suggest that parasite viability is interlinked with survival of the host snail. The mechanisms of differing toxicity between host species and its relevance to successful parasite transmission to the next host are discussed.

Salinity effects on viability, metabolic activity and proliferation of three Perkinsus species

USGS Publications Warehouse

La, Peyre M.; Casas, S.; La, Peyre J.

2006-01-01

Little is known regarding the range of conditions in which many Perkinsus species may proliferate, making it difficult to predict conditions favorable for their expansion, to identify conditions inducing mortality, or to identify instances of potential cross-infectivity among sympatric host species. In this study, the effects of salinity on viability, metabolic activity and proliferation of P. marinus, P. olseni and P. chesapeaki were determined. Specifically, this research examined the effects of 5 salinities (7, 11, 15, 25, 35???), (1) without acclimation, on the viability and metabolic activity of 2 isolates of each Perkinsus species, and (2) with acclimation, on the viability, metabolic activity, size and number of 1 isolate of each species. P. chesapeaki showed the widest range of salinity tolerance of the 3 species, with high viability and cell proliferation at all salinities tested. Although P. chesapeaki originated from low salinity areas (i.e. <15???), several measures (i.e. cell number and metabolic activity) indicated that higher salinities (15, 25???) were more favorable for its growth. P. olseni, originating from high salinity areas, had better viability and proliferation at the higher salinities (15, 25, 35???). Distinct differences in acute salinity response of the 2 P. olseni isolates at lower salinities (7, 11???), however, suggest the need for a more expansive comparison of isolates to better define the lower salinity tolerance. Lastly, P. marinus was more tolerant of the lower salinities (7 and 11???) than P. olseni, but exhibited reduced viability at 7???, even after acclimation. ?? Inter-Research 2006.

Effect of various concentrations of antibiotics on osteogenic cell viability and activity.

PubMed

Rathbone, Christopher R; Cross, Jessica D; Brown, Kate V; Murray, Clinton K; Wenke, Joseph C

2011-07-01

Infection is a common complication of open fractures. Systemic antibiotics often cause adverse events before eradication of infected bone occurs. The local delivery of antibiotics and the use of implants that deliver both growth factors and antimicrobials are ways to circumvent systemic toxicity while decreasing infection and to reach extremely high levels required to treat bacterial biofilms. When choosing an antibiotic for a local delivery system, one should consider the effect that the antibiotic has on cell viability and osteogenic activity. To address this concern, osteoblasts were treated with 21 different antibiotics over 8 concentrations from 0 to 5000 µg/ml. Osteoblast deoxyribonucleic acid content and alkaline phosphatase activity (ALP) were measured to determine cell number and osteogenic activity, respectively. Antibiotics that caused the greatest decrement include rifampin, minocycline, doxycycline, nafcillin, penicillin, ciprofloxacin, colistin methanesulfonate, and gentamicin; their cell number and ALP were significantly less than control at drug concentrations ≤ 200 µg/ml. Conversely, amikacin, tobramycin, and vancomycin were the least cytotoxic and did not appreciably affect cell number and ALP until very high concentrations were used. This comprehensive evaluation of numerous antibiotics' effects on osteoblast viability and activity will enable clinicians and researchers to choose the optimal antibiotic for treatment of infection and maintenance of healthy host bone. Copyright © 2011 Orthopaedic Research Society.

In vitro effects of dental cements on hard and soft tissues associated with dental implants.

PubMed

Rodriguez, Lucas C; Saba, Juliana N; Chung, Kwok-Hung; Wadhwani, Chandur; Rodrigues, Danieli C

2017-07-01

Dental cements for cement-retained restorations are often chosen based on clinician preference for the product's material properties, mixing process, delivery mechanism, or viscosity. The composition of dental cement may play a significant role in the proliferation or inhibition of different bacterial strains associated with peri-implant disease, and the effect of dental cements on host cellular proliferation may provide further insight into appropriate cement material selection. The purpose of this in vitro study was to investigate the cellular host response of bone cells (osteoblasts) and soft tissue cells (gingival fibroblasts) to dental cements. Zinc oxide (eugenol and noneugenol), zinc phosphate, and acrylic resin cements were molded into pellets and directly applied to confluent preosteoblast (cell line MC3T3 E1) or gingival fibroblast cell cultures (cell line HGF) to determine cellular viability after exposure. Controls were defined as confluent cell cultures with no cement exposure. Direct contact cell culture testing was conducted following International Organization for Standardization 10993 methods, and all experiments were performed in triplicate. To compare either the MC3T3 E1 cell line, or the HGF cell line alone, a 1-way ANOVA test with multiple comparisons was used (α=.05). To compare the MC3T3 E1 cell line results and the HGF cell line results, a 2-way ANOVA test with multiple comparisons was used (α=.05). The results of this study illustrated that while both bone and soft tissue cell lines were vulnerable to the dental cement test materials, the soft tissue cell line (human gingival fibroblasts) was more susceptible to reduced cellular viability after exposure. The HGF cell line was much more sensitive to cement exposure. Here, the acrylic resin, zinc oxide (eugenol), and zinc phosphate cements significantly reduced cellular viability after exposure with respect to HGF cells only. Within the limitation of this in vitro cellular study, the results indicated that cell response to various implant cements varied significantly, with osteoblast proliferation much less affected than gingival fibroblast cells. Furthermore, the zinc oxide noneugenol dental cement appeared to affect the cell lines significantly less than the other test cements. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Echinococcus multilocularis vesicular fluid inhibits activation and proliferation of natural killer cells.

PubMed

Bellanger, Anne-Pauline; Mougey, Valentine; Pallandre, Jean-Rene; Gbaguidi-Haore, Houssein; Godet, Yann; Millon, Laurence

2017-08-25

Alveolar echinococcosis is a severe chronic helminthic disease that mimics slow-growing liver cancer. The immune evasion strategy of Echinococcus multilocularis Leuckart, 1863 remains poorly understood. The aim of this study was to investigate in vitro the impact of E. multilocularis vesicular fluid (Em-VF) on peripheral blood mononuclear cells (PBMC) and on natural killer (NK) cells. PBMC and NK cells were exposed to Em-VF (1 µg/ml) during six days. The effect of Em-VF was assessed on CD69, viability and proliferation, and on and transforming growth factor β (TGF-β), interferon γ (IFN-γ), interleukin 17 (IL-17) and interleukin 10, using flow cytometry and ELISA, respectively. Exposure to Em-VF had no bearing on PBMC's viability, proliferation and expression of CD69. In contrast, higher levels of IL-17 at day three and of TGF-β at day six were observed in PBMC supernatant after exposure to Em-VF (p < 0.05, Wilcoxon signed-rank test). Exposure to Em-VF induced a significant decrease of CD69 expression of NK cells at day three and a significant decrease of proliferation of NK cells at day six (p < 0.05, Wilcoxon signed-rank test). In contrast, NK cells viability and levels of cytokines did not vary significantly over Em-VF stimulation. Exposure to Em-VF had a significant bearing on activation and proliferation of NK cells. NK cells may play an important role in the immune response of the host against E. multilocularis.

Ixazomib suppresses human dendritic cell and modulates murine graft-versus-host disease in a schedule-dependent fashion.

PubMed

Al-Homsi, Ahmad Samer; Goodyke, Austin; Cole, Kelli; Muilenburg, Marlee; McLane, Michael; Abdel-Mageed, Sarah; Feng, Yuxin

2017-04-01

There is an abiding need for innovative approaches to the prevention of graft-versus-host disease (GvHD) following allogeneic hematopoietic stem cell transplantation (HSCT). Interest in prevention of GvHD by dendritic cell (DC) suppression has re-emerged since the introduction of proteasome inhibitors into clinical practice. Ixazomib is an orally bioavailable proteasome inhibitor with a rapid proteasome dissociation rate. We studied the effects of ixazomib on human DC maturation, viability, and cytokine production in vitro. We also determined the effects of ixazomib in a murine GvHD model. Although ixazomib suppressed naïve human DC maturation, it had only a limited effect on cell viability. Ixazomib decreased pro-inflammatory cytokine production of resting DCs. This effect was diminished or reversed when DCs were pre-stimulated. In vivo, ixazomib administered post-transplantation on days +1 and +4 or days -1, +2, and +5 ameliorated GvHD in comparison to the GvHD group. Although a fraction of mice treated according to the prolonged schedule died abruptly after the day +5 treatment, both schedules resulted in improved overall survival. When we examined the effects of ixazomib on splenic cells and serum cytokines, we found that ixazomib exerted complex schedule-dependent immunomodulatory effects. Our study provides a rationale for the potential use of ixazomib in the prevention of GvHD. Copyright © 2016 ISEH - International Society for Experimental Hematology. Published by Elsevier Inc. All rights reserved.

In Vitro Effect of the Synthetic cal14.1a Conotoxin, Derived from Conus californicus, on the Human Parasite Toxoplasma gondii

PubMed Central

De León-Nava, Marco A.; Romero-Núñez, Eunice; Luna-Nophal, Angélica; Bernáldez-Sarabia, Johanna; Sánchez-Campos, Liliana N.; Licea-Navarro, Alexei F.; Morales-Montor, Jorge; Muñiz-Hernández, Saé

2016-01-01

Toxins that are secreted by cone snails are small peptides that are used to treat several diseases. However, their effects on parasites with human and veterinary significance are unknown. Toxoplasma gondii is an opportunistic parasite that affects approximately 30% of the world’s population and can be lethal in immunologically compromised individuals. The conventional treatment for this parasitic infection has remained the same since the 1950s, and its efficacy is limited to the acute phase of infection. These findings have necessitated the search for new drugs that specifically target T. gondii. We examined the effects of the synthetic toxin cal14.1a (s-cal14.1a) from C. californicus on the tachyzoite form of T. gondii. Our results indicate that, at micromolar concentrations, s-cal14.1a lowers viability and inhibits host cell invasion (by 50% and 61%, respectively) on exposure to extracellular parasites. Further, intracellular replication decreased significantly while viability of the host cell was unaffected. Our study is the first report on the antiparasitic activity of a synthetic toxin of C. californicus. PMID:27070627

Elevated Cholesterol in the Coxiella burnetii Intracellular Niche Is Bacteriolytic

PubMed Central

Mulye, Minal; Samanta, Dhritiman; Winfree, Seth; Heinzen, Robert A.

2017-01-01

ABSTRACT Coxiella burnetii is an intracellular bacterial pathogen and a significant cause of culture-negative endocarditis in the United States. Upon infection, the nascent Coxiella phagosome fuses with the host endocytic pathway to form a large lysosome-like vacuole called the parasitophorous vacuole (PV). The PV membrane is rich in sterols, and drugs perturbing host cell cholesterol homeostasis inhibit PV formation and bacterial growth. Using cholesterol supplementation of a cholesterol-free cell model system, we found smaller PVs and reduced Coxiella growth as cellular cholesterol concentration increased. Further, we observed in cells with cholesterol a significant number of nonfusogenic PVs that contained degraded bacteria, a phenotype not observed in cholesterol-free cells. Cholesterol had no effect on axenic Coxiella cultures, indicating that only intracellular bacteria are sensitive to cholesterol. Live-cell microscopy revealed that both plasma membrane-derived cholesterol and the exogenous cholesterol carrier protein low-density lipoprotein (LDL) traffic to the PV. To test the possibility that increasing PV cholesterol levels affects bacterial survival, infected cells were treated with U18666A, a drug that traps cholesterol in lysosomes and PVs. U18666A treatment led to PVs containing degraded bacteria and a significant loss in bacterial viability. The PV pH was significantly more acidic in cells with cholesterol or cells treated with U18666A, and the vacuolar ATPase inhibitor bafilomycin blocked cholesterol-induced PV acidification and bacterial death. Additionally, treatment of infected HeLa cells with several FDA-approved cholesterol-altering drugs led to a loss of bacterial viability, a phenotype also rescued by bafilomycin. Collectively, these data suggest that increasing PV cholesterol further acidifies the PV, leading to Coxiella death. PMID:28246364

Pleomorphism and Viability of the Lyme Disease Pathogen Borrelia burgdorferi Exposed to Physiological Stress Conditions: A Correlative Cryo-Fluorescence and Cryo-Scanning Electron Microscopy Study.

PubMed

Vancová, Marie; Rudenko, Nataliia; Vaněček, Jiří; Golovchenko, Maryna; Strnad, Martin; Rego, Ryan O M; Tichá, Lucie; Grubhoffer, Libor; Nebesářová, Jana

2017-01-01

To understand the response of the Lyme disease spirochete Borrelia burgdorferi exposed to stress conditions and assess the viability of this spirochete, we used a correlative cryo-fluorescence and cryo-scanning microscopy approach. This approach enables simple exposition of bacteria to various experimental conditions that can be stopped at certain time intervals by cryo-immobilization, examination of cell viability without necessity to maintain suitable culture conditions during viability assays, and visualization of structures in their native state at high magnification. We focused on rare and transient events e.g., the formation of round bodies and the presence of membranous blebs in spirochetes exposed to culture medium, host sera either without or with the bacteriolytic effect and water. We described all crucial steps of the workflow, particularly the influence of freeze-etching and accelerating voltage on the visualization of topography. With the help of newly designed cryo-transport device, we achieved greater reproducibility.

Characterization of an Sf-rhabdovirus-negative Spodoptera frugiperda cell line as an alternative host for recombinant protein production in the baculovirus-insect cell system.

PubMed

Maghodia, Ajay B; Geisler, Christoph; Jarvis, Donald L

2016-06-01

Cell lines derived from the fall armyworm, Spodoptera frugiperda (Sf), are widely used as hosts for recombinant protein production in the baculovirus-insect cell system (BICS). However, it was recently discovered that these cell lines are contaminated with a virus, now known as Sf-rhabdovirus [1]. The detection of this adventitious agent raised a potential safety issue that could adversely impact the BICS as a commercial recombinant protein production platform. Thus, we examined the properties of Sf-RVN, an Sf-rhabdovirus-negative Sf cell line, as a potential alternative host. Nested RT-PCR assays showed Sf-RVN cells had no detectable Sf-rhabdovirus over the course of 60 passages in continuous culture. The general properties of Sf-RVN cells, including their average growth rates, diameters, morphologies, and viabilities after baculovirus infection, were virtually identical to those of Sf9 cells. Baculovirus-infected Sf-RVN and Sf9 cells produced equivalent levels of three recombinant proteins, including an intracellular prokaryotic protein and two secreted eukaryotic glycoproteins, and provided similar N-glycosylation patterns. In fact, except for the absence of Sf-rhabdovirus, the only difference between Sf-RVN and Sf9 cells was SF-RVN produced higher levels of infectious baculovirus progeny. These results show Sf-RVN cells can be used as improved, alternative hosts to circumvent the potential safety hazard associated with the use of Sf-rhabdovirus-contaminated Sf cells for recombinant protein manufacturing with the BICS. Copyright © 2016 Elsevier Inc. All rights reserved.

A potential target gene for the host-directed therapy of mycobacterial infection in murine macrophages

PubMed Central

Bao, Zhang; Chen, Ran; Zhang, Pei; Lu, Shan; Chen, Xing; Yao, Yake; Jin, Xiaozheng; Sun, Yilan; Zhou, Jianying

2016-01-01

Mycobacterium tuberculosis (MTB), one of the major bacterial pathogens for lethal infectious diseases, is capable of surviving within the phagosomes of host alveolar macrophages; therefore, host genetic variations may alter the susceptibility to MTB. In this study, to identify host genes exploited by MTB during infection, genes were non-selectively inactivated using lentivirus-based antisense RNA methods in RAW264.7 macrophages, and the cells that survived virulent MTB infection were then screened. Following DNA sequencing of the surviving cell clones, 26 host genes affecting susceptibility to MTB were identified and their pathways were analyzed by bioinformatics analysis. In total, 9 of these genes were confirmed as positive regulators of collagen α-5(IV) chain (Col4a5) expression, a gene encoding a type IV collagen subunit present on the cell surface. The knockdown of Col4a5 consistently suppressed intracellular mycobacterial viability, promoting the survival of RAW264.7 macrophages following mycobacterial infection. Furthermore, Col4a5 deficiency lowered the pH levels of intracellular vesicles, including endosomes, lysosomes and phagosomes in the RAW264.7 cells. Finally, the knockdown of Col4a5 post-translationally increased microsomal vacuolar-type H+-ATPase activity in macrophages, leading to the acidification of intracellular vesicles. Our findings reveal a novel role for Col4a5 in the regulation of macrophage responses to mycobacterial infection and identify Col4a5 as a potential target for the host-directed anti-mycobacterial therapy. PMID:27432120

Cell Viability and Functionality of Probiotic Bacteria in Dairy Products

PubMed Central

Vinderola, Gabriel; Binetti, Ana; Burns, Patricia; Reinheimer, Jorge

2011-01-01

Probiotic bacteria, according to the definition adopted by the World Health Organization in 2002, are live microorganisms, which when administered in adequate amounts confer a health benefit to the host. Recent studies show that the same probiotic strain produced and/or preserved under different storage conditions, may present different responses regarding their susceptibility to the adverse conditions of the gastrointestinal tract, its capacity to adhere to the intestinal epithelium, or its immunomodulating capacity, the functionality being affected without changes in cell viability. This could imply that the control of cell viability is not always enough to guarantee the functionality (probiotic capacity) of a strain. Therefore, a new challenge arises for food technologists and microbiologists when it comes to designing and monitoring probiotic food: to be able to monitor the functionality of a probiotic microorganism throughout all the stages the strain goes through from the moment it is produced and included in the food vehicle, until the moment of consumption. Conventional methodological tools or others still to be developed must be used. The application of cell membrane functionality markers, the use of tests of resistance to intestinal barriers, the study of surface properties and the application of in vivo models come together as complementary tools to assess the actual capacity of a probiotic organism in a specific food, to exert functional effects regardless of the number of viable cells present at the moment of consumption. PMID:21833320

Challenges and Strategies for Proteome Analysis of the Interaction of Human Pathogenic Fungi with Host Immune Cells.

PubMed

Krüger, Thomas; Luo, Ting; Schmidt, Hella; Shopova, Iordana; Kniemeyer, Olaf

2015-12-14

Opportunistic human pathogenic fungi including the saprotrophic mold Aspergillus fumigatus and the human commensal Candida albicans can cause severe fungal infections in immunocompromised or critically ill patients. The first line of defense against opportunistic fungal pathogens is the innate immune system. Phagocytes such as macrophages, neutrophils and dendritic cells are an important pillar of the innate immune response and have evolved versatile defense strategies against microbial pathogens. On the other hand, human-pathogenic fungi have sophisticated virulence strategies to counteract the innate immune defense. In this context, proteomic approaches can provide deeper insights into the molecular mechanisms of the interaction of host immune cells with fungal pathogens. This is crucial for the identification of both diagnostic biomarkers for fungal infections and therapeutic targets. Studying host-fungal interactions at the protein level is a challenging endeavor, yet there are few studies that have been undertaken. This review draws attention to proteomic techniques and their application to fungal pathogens and to challenges, difficulties, and limitations that may arise in the course of simultaneous dual proteome analysis of host immune cells interacting with diverse morphotypes of fungal pathogens. On this basis, we discuss strategies to overcome these multifaceted experimental and analytical challenges including the viability of immune cells during co-cultivation, the increased and heterogeneous protein complexity of the host proteome dynamically interacting with the fungal proteome, and the demands on normalization strategies in terms of relative quantitative proteome analysis.

Dynamic Electrochemical Control of Cell Capture-and-Release Based on Redox-Controlled Host-Guest Interactions.

PubMed

Gao, Tao; Li, Liudi; Wang, Bei; Zhi, Jun; Xiang, Yang; Li, Genxi

2016-10-18

Artificial control of cell adhesion on smart surface is an on-demand technique in areas ranging from tissue engineering, stem cell differentiation, to the design of cell-based diagnostic system. In this paper, we report an electrochemical system for dynamic control of cell catch-and-release, which is based on the redox-controlled host-guest interaction. Experimental results reveal that the interaction between guest molecule (ferrocene, Fc) and host molecule (β-cyclodextrin, β-CD) is highly sensitive to electrochemical stimulus. By applying a reduction voltage, the uncharged Fc can bind to β-CD that is immobilized at the electrode surface. Otherwise, it is disassociated from the surface as a result of electrochemical oxidation, thus releasing the captured cells. The catch-and-release process on this voltage-responsive surface is noninvasive with the cell viability over 86%. Moreover, because Fc can act as an electrochemical probe for signal readout, the integration of this property has further extended the ability of this system to cell detection. Electrochemical signal has been greatly enhanced for cell detection by introducing branched polymer scaffold that are carrying large quantities of Fc moieties. Therefore, a minimum of 10 cells can be analyzed. It is anticipated that such redox-controlled system can be an important tool in biological and biomedical research, especially for electrochemical stimulated tissue engineering and cell-based clinical diagnosis.

In vitro biocorrosion of Co-Cr-Mo implant alloy by macrophage cells.

PubMed

Lin, Hsin-Yi; Bumgardner, Joel D

2004-11-01

We hypothesized that macrophage cells and their released reactive chemical species (RCS) affect Co-Cr-Mo alloy's corrosion properties and that alloy corrosion products change macrophage cell behavior. A custom cell culture corrosion cell was used to evaluate how culture medium, cells, and RCS altered alloy corrosion in 3-day tests. Corrosion was evaluated by measuring total charge transfer at a constant potential using a potentiostat and metal ion release by atomic emission spectroscopy. Viability, proliferation, and NO (nitric oxide) and IL-1beta (interlukin-1beta) release were used to assess cellular response to alloy corrosion products. In the presence of activated cells, total charge transfers and Co ion release were the lowest (p < 0.05). This was attributed to an enhancement of the surface oxide by RCS. Cr and Mo release were not different between cells and activated cells. Low levels of metal ions did not affect cell viability, proliferation, or NO release, though IL-1beta released from the activated cells was higher on the alloy compared to the controls. These data support the hypothesis that macrophage cells and their RCS affect alloy corrosion. Changes in alloy corrosion by cells may be important to the development of host responses to the alloy and its corrosion products.

Oseltamivir phosphate monotherapy ablates tumor neovascularization, growth, and metastasis in mouse model of human triple-negative breast adenocarcinoma

PubMed Central

Haxho, Fiona; Allison, Stephanie; Alghamdi, Farah; Brodhagen, Lacey; Kuta, Victoria EL; Abdulkhalek, Samar; Neufeld, Ronald J; Szewczuk, Myron R

2014-01-01

Background Triple-negative breast cancers (TNBCs) lack the estrogen, progesterone, and epidermal growth factor (EGF) receptor-2 (HER2/neu) receptors. Patients with TNBC have typical high grading, more frequent relapses, and exhibit poorer outcomes or prognosis compared with the other subtypes of breast cancers. Currently, there are no targeted therapies that are effective for TNBC. Preclinical antitumor activity of oseltamivir phosphate (OP) therapy was investigated to identify its role in tumor neovascularization, growth, invasiveness, and long-term survival in a mouse model of human TNBC. Methods Live cell sialidase, water soluble tetrazolium, WST-1 cell viability, and immunohistochemistry assays were used to evaluate sialidase activity, cell survival, and the expression levels of tumor E-cadherin, N-cadherin, and host endothelial CD31+/PECAM-1 cells in archived paraffin-embedded TNBC MDA-MB-231 tumors grown in RAGxCγ double mutant mice. Results OP, anti-Neu1 antibodies, and matrix metalloproteinase-9-specific inhibitor blocked Neu1 activity associated with EGF-stimulated TNBC MDA-MB-231 cells. OP treatment of MDA-MB-231 and MCF-7 cells and their long-term tamoxifen-resistant clones reproducibly and dose-dependently reduced the sialidase activity associated with EGF-stimulated live cells and the cell viability after 72 hours of incubation. Combination of 1 μM cisplatin, 5-FU, paclitaxel, gemcitabine, or tamoxifen with OP dosages ≥300 μg/mL significantly reduced cell viability at 24, 48, and 72 hours when compared to the chemodrug alone. Heterotopic xenografts of MDA-MB-231 tumors developed robust and bloody tumor vascularization in RAG2xCγ double mutant mice. OP treatment at 30 mg/kg daily intraperitoneally reduced tumor vascularization and growth rate as well as significantly reduced tumor weight and spread to the lungs compared with the untreated cohorts. OP treatment at 50 mg/kg completely ablated tumor vascularization, tumor growth and spread to the lungs, with significant long-term survival at day 180 postimplantation, tumor shrinking, and no relapses after 56 days off-drug. OP 30 mg/kg cohort tumors expressed significantly reduced levels of human N-cadherins and host CD31+ endothelial cells with concomitant significant expression of E-cadherins compared to the untreated cohorts. Conclusion OP monotherapy may be the effective treatment therapy for TNBC. PMID:25525387

Development and application of a sensitive, phenotypic, high-throughput image-based assay to identify compound activity against Trypanosoma cruzi amastigotes

PubMed Central

Sykes, Melissa L.; Avery, Vicky M.

2015-01-01

We have developed a high content 384-well, image-based assay to estimate the effect of compound treatment on Trypanosoma cruzi amastigotes in 3T3 fibroblasts. In the same well, the effect of compound activity on host cells can also be determined, as an initial indicator of cytotoxicity. This assay has been used to identify active compounds from an in-house library of compounds with either known biological activity or that are FDA approved, and separately, from the Medicines for Malaria Venture Malaria Box collection. Active compounds were screened against T. cruzi trypomastigotes, utilising an assay developed with the viability dye resazurin. Twelve compounds with reconfirmed solid sample activity, with IC50 values of less than 10 μM and selectivity indices to T. cruzi amastigotes over 3T3 host cells of between >22 and 319 times were identified from these libraries. As 3T3 cells are contact inhibited, with limited proliferation in the assay, selective compounds of interest were profiled in a separate assay to estimate the viability of compound treated, replicating HEK293 cells. Selective compounds that were not previously reported in the literature were further profiled by extending the incubation time against amastigote infected 3T3 cells to determine if there were residual amastigotes post-treatment, important for the consideration of the exposure time required for further biological characterisation. The assay development process and the suitability of identified compounds as hit molecules for Chagas disease research are discussed. PMID:27120069

Development and application of a sensitive, phenotypic, high-throughput image-based assay to identify compound activity against Trypanosoma cruzi amastigotes.

PubMed

Sykes, Melissa L; Avery, Vicky M

2015-12-01

We have developed a high content 384-well, image-based assay to estimate the effect of compound treatment on Trypanosoma cruzi amastigotes in 3T3 fibroblasts. In the same well, the effect of compound activity on host cells can also be determined, as an initial indicator of cytotoxicity. This assay has been used to identify active compounds from an in-house library of compounds with either known biological activity or that are FDA approved, and separately, from the Medicines for Malaria Venture Malaria Box collection. Active compounds were screened against T. cruzi trypomastigotes, utilising an assay developed with the viability dye resazurin. Twelve compounds with reconfirmed solid sample activity, with IC50 values of less than 10 μM and selectivity indices to T. cruzi amastigotes over 3T3 host cells of between >22 and 319 times were identified from these libraries. As 3T3 cells are contact inhibited, with limited proliferation in the assay, selective compounds of interest were profiled in a separate assay to estimate the viability of compound treated, replicating HEK293 cells. Selective compounds that were not previously reported in the literature were further profiled by extending the incubation time against amastigote infected 3T3 cells to determine if there were residual amastigotes post-treatment, important for the consideration of the exposure time required for further biological characterisation. The assay development process and the suitability of identified compounds as hit molecules for Chagas disease research are discussed. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Synthesis and Biological Evaluation of Analogues of AKT (Protein Kinase B) Inhibitor-IV

PubMed Central

Sun, Qi; Wu, Runzhi; Cai, Sutang; Lin, Yuan; Sellers, Llewlyn; Sakamoto, Kaori; He, Biao; Peterson, Blake R.

2011-01-01

Inhibitors of the PI3-kinase/AKT (protein kinase B) pathway are under investigation as anticancer and antiviral agents. The benzimidazole derivative AKT inhibitor-IV (ChemBridge 5233705) affects this pathway and exhibits potent anticancer and antiviral activity. To probe its biological activity, we synthesized AKT inhibitor-IV and 21 analogues using a novel six-step route based on ZrCl4-catalyzed cyclization of 1,2-arylenediamines with α,β-unsaturated aldehydes. We examined effects on viability of HeLa carcinoma cells, viability of normal human cells (NHBE), replication of recombinant parainfluenza virus 5 (PIV5) in HeLa cells, and replication of the intracellular bacterium Mycobacterium fortuitum in HeLa cells. Replacement of the benzimidazole N-ethyl substitutent of AKT inhibitor-IV with N-hexyl and N-dodecyl groups enhanced antiviral activity and cytotoxicity against the cancer cell line, but these compounds showed substantially lower toxicity (from 6-fold to >20-fold) against NHBE cells, and no effect on M. fortuitum, suggesting inhibition of one or more host protein(s) required for proliferation of cancer cells and PIV5. The key structural elements identified here may facilitate identification of targets of this highly biologically active scaffold. PMID:21319800

Engineering tolerance to industrially relevant stress factors in yeast cell factories.

PubMed

Deparis, Quinten; Claes, Arne; Foulquié-Moreno, Maria R; Thevelein, Johan M

2017-06-01

The main focus in development of yeast cell factories has generally been on establishing optimal activity of heterologous pathways and further metabolic engineering of the host strain to maximize product yield and titer. Adequate stress tolerance of the host strain has turned out to be another major challenge for obtaining economically viable performance in industrial production. Although general robustness is a universal requirement for industrial microorganisms, production of novel compounds using artificial metabolic pathways presents additional challenges. Many of the bio-based compounds desirable for production by cell factories are highly toxic to the host cells in the titers required for economic viability. Artificial metabolic pathways also turn out to be much more sensitive to stress factors than endogenous pathways, likely because regulation of the latter has been optimized in evolution in myriads of environmental conditions. We discuss different environmental and metabolic stress factors with high relevance for industrial utilization of yeast cell factories and the experimental approaches used to engineer higher stress tolerance. Improving stress tolerance in a predictable manner in yeast cell factories should facilitate their widespread utilization in the bio-based economy and extend the range of products successfully produced in large scale in a sustainable and economically profitable way. © FEMS 2017.

Engineering tolerance to industrially relevant stress factors in yeast cell factories

PubMed Central

Deparis, Quinten; Claes, Arne; Foulquié-Moreno, Maria R.

2017-01-01

Abstract The main focus in development of yeast cell factories has generally been on establishing optimal activity of heterologous pathways and further metabolic engineering of the host strain to maximize product yield and titer. Adequate stress tolerance of the host strain has turned out to be another major challenge for obtaining economically viable performance in industrial production. Although general robustness is a universal requirement for industrial microorganisms, production of novel compounds using artificial metabolic pathways presents additional challenges. Many of the bio-based compounds desirable for production by cell factories are highly toxic to the host cells in the titers required for economic viability. Artificial metabolic pathways also turn out to be much more sensitive to stress factors than endogenous pathways, likely because regulation of the latter has been optimized in evolution in myriads of environmental conditions. We discuss different environmental and metabolic stress factors with high relevance for industrial utilization of yeast cell factories and the experimental approaches used to engineer higher stress tolerance. Improving stress tolerance in a predictable manner in yeast cell factories should facilitate their widespread utilization in the bio-based economy and extend the range of products successfully produced in large scale in a sustainable and economically profitable way. PMID:28586408

Production of interleukin-10 by human bronchogenic carcinoma.

PubMed Central

Smith, D. R.; Kunkel, S. L.; Burdick, M. D.; Wilke, C. A.; Orringer, M. B.; Whyte, R. I.; Strieter, R. M.

1994-01-01

Interleukin-10 (IL-10) is a recently characterized cytokine with suppressive activity against various aspects of the cellular immune response. Our laboratory has previously demonstrated that another anti-inflammatory cytokine, IL-1 receptor antagonist (IRAP) is produced and secreted by human bronchogenic carcinomas. We speculated that tumor production of IRAP may mitigate host responses and confer increased tumor viability. In this study, we investigated the capacity of human bronchogenic tumors to produce IL-10 as another possible mechanism to attenuate host defenses. We found increased levels of antigenic IL-10 in tissue homogenates of human bronchogenic carcinomas compared with normal lung tissue (13.69 +/- 2.87 versus 5.84 +/- 0.84 ng/mg total protein). Immunohistochemical staining of tumors illustrate primary localization of antigenic IL-10 to individual tumor cells. Analysis of supernatants of several unstimulated human bronchogenic cell lines in vitro demonstrated the ability of tumor cells to constitutively produce IL-10. Functional studies of mononuclear cells, cultured in the presence of conditioned medium from a bronchogenic cell line, demonstrated their increased tumor necrosis factor and IL-6 production with the addition of neutralizing antibodies to IL-10. These findings demonstrate that human bronchogenic carcinomas elaborate functional IL-10, which may significantly impair immune effector cell function and enable the tumor to evade host defenses. Images Figure 1 Figure 2 PMID:8030748

Granulocyte-macrophage colony-stimulating factor responses of oral epithelial cells to Candida albicans.

PubMed

Dongari-Bagtzoglou, A; Kashleva, H

2003-06-01

Candida albicans is the principal fungal species responsible for oropharyngeal candidiasis, the most frequent opportunistic infection associated with immune deficiencies. Cytokines, such as granulocyte-macrophage colony-stimulating factor (GM-CSF), are important in the generation of effective immunity to C. albicans. The purposes of this investigation were to determine whether C. albicans triggers secretion of GM-CSF by oral epithelial cells in vitro and to investigate mechanisms of host cell-fungal interactions that trigger such responses. Oral epithelial cell lines as well as primary oral mucosal epithelial cells were challenged with stationary phase viable C. albicans, added to human cell cultures at varying yeast:oral cell ratios. Yeast were allowed to germinate for up to 48 h and supernatants were analyzed for GM-CSF by ELISA. Fixed organisms, germination-deficient mutants and separation of yeast from epithelial cells using cell culture inserts were used to assess the effects of viability, germination and physical contact, respectively, on the GM-CSF responses of these cells. Two out of three cell lines and three out of six primary cultures responded to C. albicans with an increase in GM-CSF secretion. GM-CSF responses were contact-dependent, strain-dependent, required yeast viability and were optimal when the yeast germinated into hyphae.

Alginate microencapsulation technology for the percutaneous delivery of adipose-derived stem cells.

PubMed

Moyer, Hunter R; Kinney, Ramsey C; Singh, Kimberly A; Williams, Joseph K; Schwartz, Zvi; Boyan, Barbara D

2010-11-01

Autologous fat is the ideal soft-tissue filler; however, its widespread application is limited because of variable clinical results and poor survival. Engineered fillers have the potential to maximize survival. Alginate is a hydrogel copolymer that can be engineered into spheres of <200 μm, thus facilitating mass transfer, allowing for subcutaneous injection, and protecting cells from shearing forces. Alginate powder was dissolved in saline, and adipose-derived stem cells (ADSCs) were encapsulated (1 million cells/mL) in alginate using an electrostatic bead generator. To assess effects of injection on cell viability, microspheres containing ADSCs were separated into 2 groups: the control group was decanted into culture wells and the injection group was mixed with basal media and injected through a 21-gauge needle into culture wells. Microbeads were cultured for 3 weeks, and cell number and viability were measured weekly using electron and confocal microscopy. To assess effects of percutaneous injection in vivo, twenty-four male nude mice were randomly separated into 2 groups and injected with either empty microcapsules or ADSC-laden microcapsules. Mice were harvested at 1 and 3 months, and the implants were examined microscopically to assess bead and cell viability. A flow rate of 5 mL/h and an electrostatic potential of 7 kV produced viable ADSC-laden microbeads of <200 μm. There were no differences in bead morphology and ADSC viability between microcapsules placed versus injected into tissue culture plates for up to 3 weeks. Microspheres implanted in a nude mouse model show durability up to 3 months with a host response around each individual sphere. ADSCs remained viable and showed signs of mitosis. ADSCs can be readily cultured, encapsulated, and injected in alginate microspheres. Stem cells suspended in alginate microspheres survive in vivo and are seen to replicate in vitro.

Toxoplasma gondii Is Dependent on Glutamine and Alters Migratory Profile of Infected Host Bone Marrow Derived Immune Cells through SNAT2 and CXCR4 Pathways

PubMed Central

Lee, I-Ping; Works, Melissa G.; Kumar, Vineet; De Miguel, Zurine; Manley, Nathan C.; Sapolsky, Robert M.

2014-01-01

The obligate intracellular parasite, Toxoplasma gondii, disseminates through its host inside infected immune cells. We hypothesize that parasite nutrient requirements lead to manipulation of migratory properties of the immune cell. We demonstrate that 1) T. gondii relies on glutamine for optimal infection, replication and viability, and 2) T. gondii-infected bone marrow-derived dendritic cells (DCs) display both “hypermotility” and “enhanced migration” to an elevated glutamine gradient in vitro. We show that glutamine uptake by the sodium-dependent neutral amino acid transporter 2 (SNAT2) is required for this enhanced migration. SNAT2 transport of glutamine is also a significant factor in the induction of migration by the small cytokine stromal cell-derived factor-1 (SDF-1) in uninfected DCs. Blocking both SNAT2 and C-X-C chemokine receptor 4 (CXCR4; the unique receptor for SDF-1) blocks hypermotility and the enhanced migration in T. gondii-infected DCs. Changes in host cell protein expression following T. gondii infection may explain the altered migratory phenotype; we observed an increase of CD80 and unchanged protein level of CXCR4 in both T. gondii-infected and lipopolysaccharide (LPS)-stimulated DCs. However, unlike activated DCs, SNAT2 expression in the cytosol of infected cells was also unchanged. Thus, our results suggest an important role of glutamine transport via SNAT2 in immune cell migration and a possible interaction between SNAT2 and CXCR4, by which T. gondii manipulates host cell motility. PMID:25299045

Differential survival of Ichthyophonus isolates indicates parasite adaptation to its host environment

USGS Publications Warehouse

Hershberger, P.K.; Pacheco, C.A.; Gregg, J.L.; Purcell, M.K.; LaPatra, S.E.

2008-01-01

In vitro viability of Ichthyophonus spp. spores in seawater and freshwater corresponded with the water type of the host from which the spores were isolated. Among Ichthyophonus spp. spores from both marine and freshwater fish hosts (Pacific herring, Clupea pallasii, and rainbow trout, Oncorhynchus mykiss, respectively), viability was significantly greater (P < 0.05) after incubation in seawater than in freshwater at all time points from 1 to 60 min after immersion; however, magnitude of the spore tolerances to water type differed with host origin. Ichthyophonus sp. adaptation to its host environment was indicated by greater seawater tolerance of spores from the marine host and greater freshwater tolerance of spores from the freshwater host. Prolonged aqueous survival of Ichthyophonus spp. spores in the absence of a host provides insight into routes of transmission, particularly among planktivorous fishes, and should be considered when designing strategies to dispose of infected fish carcasses and tissues.

Cryopreservation has no effect on function of natural killer cells differentiated in vitro from umbilical cord blood CD34(+) cells.

PubMed

Domogala, Anna; Madrigal, J Alejandro; Saudemont, Aurore

2016-06-01

Natural killer (NK) cells offer the potential for a powerful cellular immunotherapy because they can target malignant cells without being direct effectors of graft-versus-host disease. We have previously shown that high numbers of functional NK cells can be differentiated in vitro from umbilical cord blood (CB) CD34(+) cells. To develop a readily available, off-the-shelf cellular product, it is essential that NK cells differentiated in vitro can be frozen and thawed while maintaining the same phenotype and functions. We evaluated the phenotype and function of fresh and frozen NK cells differentiated in vitro. We also assessed whether the concentration of NK cells at the time of freezing had an impact on cell viability. We found that cell concentration of NK cells at the time of freezing did not have an impact on their viability and on cell recovery post-thaw. Moreover, freezing of differentiated NK cells in vitro did not affect their phenotype, cytotoxicity and degranulation capacity toward K562 cells, cytokine production and proliferation. We are therefore able to generate large numbers of functional NK cells from CB CD34(+) cells that maintain the same phenotype and function post-cryopreservation, which will allow for multiple infusions of a highly cytotoxic NK cell product. Copyright © 2016 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

The enemy within: Targeting host-parasite interaction for antileishmanial drug discovery.

PubMed

Lamotte, Suzanne; Späth, Gerald F; Rachidi, Najma; Prina, Eric

2017-06-01

The state of antileishmanial chemotherapy is strongly compromised by the emergence of drug-resistant Leishmania. The evolution of drug-resistant phenotypes has been linked to the parasites' intrinsic genome instability, with frequent gene and chromosome amplifications causing fitness gains that are directly selected by environmental factors, including the presence of antileishmanial drugs. Thus, even though the unique eukaryotic biology of Leishmania and its dependence on parasite-specific virulence factors provide valid opportunities for chemotherapeutical intervention, all strategies that target the parasite in a direct fashion are likely prone to select for resistance. Here, we review the current state of antileishmanial chemotherapy and discuss the limitations of ongoing drug discovery efforts. We finally propose new strategies that target Leishmania viability indirectly via mechanisms of host-parasite interaction, including parasite-released ectokinases and host epigenetic regulation, which modulate host cell signaling and transcriptional regulation, respectively, to establish permissive conditions for intracellular Leishmania survival.

Genome Expression Profiling-Based Identification and Administration Efficacy of Host-Directed Antimicrobial Drugs against Respiratory Infection by Nontypeable Haemophilus influenzae

PubMed Central

Euba, Begoña; Moleres, Javier; Segura, Víctor; Viadas, Cristina; Morey, Pau; Moranta, David; Leiva, José; de-Torres, Juan Pablo; Bengoechea, José Antonio

2015-01-01

Therapies that are safe, effective, and not vulnerable to developing resistance are highly desirable to counteract bacterial infections. Host-directed therapeutics is an antimicrobial approach alternative to conventional antibiotics based on perturbing host pathways subverted by pathogens during their life cycle by using host-directed drugs. In this study, we identified and evaluated the efficacy of a panel of host-directed drugs against respiratory infection by nontypeable Haemophilus influenzae (NTHi). NTHi is an opportunistic pathogen that is an important cause of exacerbation of chronic obstructive pulmonary disease (COPD). We screened for host genes differentially expressed upon infection by the clinical isolate NTHi375 by analyzing cell whole-genome expression profiling and identified a repertoire of host target candidates that were pharmacologically modulated. Based on the proposed relationship between NTHi intracellular location and persistence, we hypothesized that drugs perturbing host pathways used by NTHi to enter epithelial cells could have antimicrobial potential against NTHi infection. Interfering drugs were tested for their effects on bacterial and cellular viability, on NTHi-epithelial cell interplay, and on mouse pulmonary infection. Glucocorticoids and statins lacked in vitro and/or in vivo efficacy. Conversely, the sirtuin-1 activator resveratrol showed a bactericidal effect against NTHi, and the PDE4 inhibitor rolipram showed therapeutic efficacy by lowering NTHi375 counts intracellularly and in the lungs of infected mice. PDE4 inhibition is currently prescribed in COPD, and resveratrol is an attractive geroprotector for COPD treatment. Together, these results expand our knowledge of NTHi-triggered host subversion and frame the antimicrobial potential of rolipram and resveratrol against NTHi respiratory infection. PMID:26416856

Generation of murine induced pluripotent stem cells by using high-density distributed electrodes network.

PubMed

Lu, Ming-Yu; Li, Zhihong; Hwang, Shiaw-Min; Linju Yen, B; Lee, Gwo-Bin

2015-09-01

This study reports a robust method of gene transfection in a murine primary cell model by using a high-density electrodes network (HDEN). By demonstrating high cell viability after gene transfection and successful expression of transgenes including fluorescent proteins, the HDEN device shows great promise as a solution in which reprogramming efficiency using non-viral induction for generation of murine induced pluripotent stem cells (iPSCs) is optimized. High and steady transgene expression levels in host cells of iPSCs can be demonstrated using this method. Moreover, the HDEN device achieved successful gene transfection with a low voltage of less than 180 V while requiring relatively low cell numbers (less than 1.5 × 10(4) cells). The results are comparable to current conventional methods, demonstrating a reasonable fluorescent-plasmid transfection rate (42.4% in single transfection and 24.5% in triple transfection) and high cell viability of over 95%. The gene expression levels of each iPSC factor was measured to be over 10-fold higher than that reported in previous studies using a single mouse embryonic fibroblast cell. Our results demonstrate that the generation of iPSCs using HDEN transfection of plasmid DNA may be a feasible and safe alternative to using viral transfection methods in the near future.

Implanted Cell-Dense Prevascularized Tissues Develop Functional Vasculature That Supports Reoxygenation After Thrombosis

PubMed Central

White, Sean M.; Pittman, Chelsea R.; Hingorani, Ryan; Arora, Rajan; Esipova, Tatiana V.; Vinogradov, Sergei A.; Hughes, Christopher C.W.; Choi, Bernard

2014-01-01

Achieving adequate vascularization within implanted engineered tissues is a significant obstacle to maintaining viability and functionality. In vitro prevascularization of engineered tissues has been explored as a potential solution to this challenge. The traditional paradigm of in vitro prevascularization is to implant an engineered tissue with a preformed vascular network that is perfused after anastomosis with the host circulation. We investigated the efficacy of this strategy by implanting cell-dense prevascularized tissues created via cell-mediated contraction and composed of collagen and a collagen-fibrin mixture into dorsal window chambers surgically prepared on immunocompromised mice. We found that host-implant anastomosis takes place in 2–6 days and that perfusion of vessels within the implants is subsequently restricted by thrombosis. However, by day 7, a functional vascular network composed of host and implant vessels developed. Prevascularization enhanced intra-implant pO2 significantly as early as 2 days postimplantation, reaching a maximum of 55 mmHg by day 8, which was significantly greater than the maximum within cellularized control tissues (18 mmHg). By day 14, collagen tissues supported ∼0.51×109 implanted and host-derived cells per mL. Our findings elucidate key features of in vitro prevascularization that can be used toward the design of larger and more functionally complex engineered tissues. PMID:24593148

Copper(II)-bis(thiosemicarbazonato) complexes as anti-chlamydial agents.

PubMed

Marsh, James W; Djoko, Karrera Y; McEwan, Alastair G; Huston, Wilhelmina M

2017-09-29

Lipophilic copper (Cu)-containing complexes have shown promising antibacterial activity against a range of bacterial pathogens. To examine the susceptibility of the intracellular human pathogen Chlamydia trachomatis to copper complexes containing bis(thiosemicarbazone) ligands [Cu(btsc)], we tested the in vitro effect of CuII-diacetyl- and CuII-glyoxal-bis[N(4)-methylthiosemicarbazonato] (Cu(atsm) and Cu(gtsm), respectively) on C. trachomatis. Cu(atsm) and to a greater extent, Cu(gtsm), prevented the formation of infectious chlamydial progeny. Impacts on host cell viability and respiration were also observed in addition to the Chlamydia impacts. This work suggests that copper-based complexes may represent a new lead approach for future development of new therapeutics against chlamydial infections, although host cell impacts need to be fully explored. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Pneumocystis Melanins Confer Enhanced Organism Viability

PubMed Central

Icenhour, Crystal R.; Kottom, Theodore J.; Limper, Andrew H.

2006-01-01

Pneumocystis continues to represent an important opportunistic fungal pathogen of those with compromised immunity. Thus, it is crucial to identify factors that affect its viability and pathogenicity. We previously reported the first identification of melanins in Pneumocystis. In the present study, we sought to further characterize these components and define the function for these melanins. Melanins extracted from Pneumocystis and melanized Pneumocystis cells were analyzed by electron spin resonance spectroscopy, revealing spectra consistent with melanins from other fungi. Immunofluorescence assays using anti-melanin monoclonal antibodies showed that melanins are widely present across Pneumocystis host species, including mouse-, ferret-, and human-derived Pneumocystis organisms, as well as Pneumocystis carinii derived from rat. Using immunoelectron microscopy, melanins were found to localize to the cell wall and cytoplasm of P. carinii cysts, as well as to intracystic bodies within mature cysts. Next, the role of melanins on the maintenance of Pneumocystis viability was determined by using quantitative reverse transcription-PCR measurement of the heat shock protein mRNA under adverse environmental conditions. Using a new method to promote the melanization of Pneumocystis, we observed that strongly melanized Pneumocystis retained viability to a greater degree when exposed to UV irradiation or desiccation compared to less-pigmented organisms. These studies support our previous identification of Pneumocystis melanins across the genus, further characterize these Pneumocystis components, and demonstrate that melanins protect Pneumocystis from environmental stressors. PMID:16757739

Evaluation of Impermeant, DNA-Binding Dye Fluorescence as a Real-Time Readout of Eukaryotic Cell Toxicity in a High Throughput Screening Format

PubMed Central

Chiaraviglio, Lucius

2014-01-01

Abstract Interpretation of high throughput screening (HTS) data in cell-based assays may be confounded by cytotoxic properties of screening compounds. Therefore, assessing cell toxicity in real time during the HTS process itself would be highly advantageous. Here, we investigate the potential of putatively impermeant, fluorescent, DNA-binding dyes to give cell toxicity readout during HTS. Amongst 19 DNA-binding dyes examined, three classes were identified that were (1) permeant, (2) cytotoxic, or (3) neither permeant nor cytotoxic during 3-day incubation with a macrophage cell line. In the last class, four dyes (SYTOX Green, CellTox Green, GelGreen, and EvaGreen) gave highly robust cytotoxicity data in 384-well screening plates. As proof of principle, successful combination with a luminescence-based assay in HTS format was demonstrated. Here, both intracellular growth of Legionella pneumophila (luminescence) and host cell viability (SYTOX Green exclusion) were assayed in the same screening well. Incorporation of membrane-impermeant, DNA-binding, fluorescent dyes in HTS assays should prove useful by allowing evaluation of cytotoxicity in real time, eliminating reagent addition steps and effort associated with endpoint cell viability analysis, and reducing the need for follow-up cytotoxicity screening. PMID:24831788

Emerging Concepts in Innate Immunity.

PubMed

Pelka, Karin; De Nardo, Dominic

2018-01-01

This review introduces recent concepts in innate immunity highlighting some of the latest exciting findings. These include: the discovery of the initiator of pyroptosis, Gasdermin D, and mechanisms of inflammatory caspases in innate immune signaling; the formation of oligomeric signalosomes downstream of innate immune receptors; mechanisms that shape innate immune responses, such as cellular homeostasis, cell metabolism, and pathogen viability; rapid methods of cell-to-cell communication; the interplay between the host and its microbiome and the concept of innate immunological memory. Furthermore, we discuss open questions and illustrate how technological advances, such as CRISPR/Cas9, may provide important answers for outstanding questions in the field of innate immunity.

Riboflavin deprivation inhibits macrophage viability and activity - a study on the RAW 264.7 cell line.

PubMed

Mazur-Bialy, Agnieszka Irena; Buchala, Beata; Plytycz, Barbara

2013-08-28

Riboflavin, or vitamin B2, as a precursor of the coenzymes FAD and FMN, has an indirect influence on many metabolic processes and determines the proper functioning of several systems, including the immune system. In the human population, plasma riboflavin concentration varies from 3·1 nM (in a moderate deficiency, e.g. in pregnant women) to 10·4 nM (in healthy adults) and 300 nM (in cases of riboflavin supplementation). The purpose of the present study was to investigate the effects of riboflavin concentration on the activity and viability of macrophages, i.e. on one of the immunocompetent cell populations. The study was performed on the murine monocyte/macrophage RAW 264.7 cell line cultured in medium with various riboflavin concentrations (3·1, 10·4, 300 and 531 nM). The results show that riboflavin deprivation has negative effects on both the activity and viability of macrophages and reduces their ability to generate an immune response. Signs of riboflavin deficiency developed in RAW 264.7 cells within 4 d of culture in the medium with a low riboflavin concentration (3·1 nM). In particular, the low riboflavin content reduced the proliferation rate and enhanced apoptotic cell death connected with the release of lactate dehydrogenase. The riboflavin deprivation impaired cell adhesion, completely inhibited the respiratory burst and slightly impaired phagocytosis of the zymosan particles. In conclusion, macrophages are sensitive to riboflavin deficiency; thus, a low riboflavin intake in the diet may affect the immune system and may consequently decrease proper host immune defence.

Porcine circovirus 2 (PCV2) increases the expression of endothelial adhesion/junction molecules.

PubMed

Marks, Fernanda S; Almeida, Laura L; Driemeier, David; Canal, Cláudio; Barcellos, David E S N; Guimarães, Jorge A; Reck, José

Porcine circovirus type 2 (PCV2) is the primary causative agent of porcine circovirus disease, a complex multisystem syndrome in domestic pigs. Despite the significant economic losses caused by porcine circovirus disease, the mechanisms of pathogenesis underlying the clinical findings remain largely unclear. As various reports have highlighted the potential key role of vascular lesions in the pathogenesis of porcine circovirus disease, the aim of this work was to investigate effects of PCV2 infection on vascular endothelial cells, focusing on cell viability and expression of adhesion/junction molecules. PCV2 infection reduced endothelial cell viability, while viral infection did not affected the viability of several other classical cell lines. Also, PCV2 infection in endothelial cells displayed a dual/biphasic effect: initially, infection increased ICAM-1 expression, which can favor leukocyte recruitment and emigration to tissues and possibly inducing characteristic porcine circovirus disease inflammatory lesions; then, secondarily, infection caused an increase in zonula occludens 1 tight junction protein (ZO-1) expression, which in turn can result in difficulties for cell traffic across the endothelium and a potential impairment the immune response in peripheral tissues. These virus-induced endothelial changes could directly impact the inflammatory process of porcine circovirus disease and associated vascular/immune system disturbances. Data suggest that, among the wide range of effects induced by PCV2 on the host, endothelial modulation can be a pivotal process which can help to explain PCV2 pathogenesis in some porcine circovirus disease presentations. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

Evaluation of ZnSe(S) Quantum Dots on the Cell Viability of Prostate Cancer Cell (PC3)

NASA Astrophysics Data System (ADS)

Calderón-Ortiz, E. R.; Bailón-Ruiz, S.; Martínez-Ferrer, M.; Rodríguez-Orengo, J. F.; Perales-Pérez, O.

2018-05-01

Nanomedicine is described as the process of diagnosing, treating, and preventing disease using nanostructured materials to improve human health. Quantum dots (QDs) host suitable optical properties for light-driven therapies, e.g., photo-dynamic therapy (PDT), for cancer treatment. The efficacy of QDs-assisted PDT relies on the capability of QDs to generate reactive oxygen species, which can be enhanced by inducing structural defects at the atomic level. Furthermore, data concerning the applicability of QDs-PDT in medicine is scarce, particularly for prostate cancer cells (PC3). On this basis, and as a first step in this research, the present report focused on the direct aqueous-synthesis of water-stable ZnSe(S) QDs via a microwave-assisted synthesis approach in the presence of thioglycolic acid (TGA) and mercaptopropionic acid (MPA). XRD analysis confirmed the face centered cubic structure in host ZnS; the average crystallite size was estimated at 10 nm. The photoluminescence of MPA-capped ZnSe(S) showed a strong main emission peak around 363 nm and a trap emission, attributed to structural defects, centered on 450 nm. The photoluminescence spectrum for TGA-capped ZnSe(S) QDs exhibited only the band gap peak around 390 nm, suggesting the absence of major structural defects. In turn, cell viability assays TGA-capped ZnSe(S) were not toxic at concentrations up to 100 ppm, whereas MPA-capped ZnSe(S) evidenced cytotoxicity at a concentration of 10 ppm. The lethal dose (LD50) for the MPA-capped ZnSe(S) in the PC3 cell line was 36 ppm and 35 ppm for 24 h and 48 h, respectively.

Phosphatidylethanolamine Synthesis Is Required for Optimal Virulence of Brucella abortus▿

PubMed Central

Bukata, Lucas; Altabe, Silvia; de Mendoza, Diego; Ugalde, Rodolfo A.; Comerci, Diego J.

2008-01-01

The Brucella cell envelope contains the zwitterionic phospholipids phosphatidylcholine (PC) and phosphatidylethanolamine (PE). Synthesis of PC occurs exclusively via the PC synthase pathway, implying that the pathogen depends on the choline synthesized by the host cell to form PC. Notably, PC is necessary to sustain a chronic infection process, which suggests that the membrane lipid content is relevant for Brucella virulence. In this study we investigated the first step of PE biosynthesis in B. abortus, which is catalyzed by phosphatidylserine synthase (PssA). Disruption of pssA abrogated the synthesis of PE without affecting the growth in rich complex medium. In minimal medium, however, the mutant required choline supplementation for growth, suggesting that at least PE or PC is necessary for Brucella viability. The absence of PE altered cell surface properties, but most importantly, it impaired several virulence traits of B. abortus, such as intracellular survival in both macrophages and HeLa cells, the maturation of the replicative Brucella-containing vacuole, and mouse colonization. These results suggest that membrane phospholipid composition is critical for the interaction of B. abortus with the host cell. PMID:18931122

Biocatalytically active silCoat-composites entrapping viable Escherichia coli.

PubMed

Findeisen, A; Thum, O; Ansorge-Schumacher, M B

2014-02-01

Application of whole cells in industrial processes requires high catalytic activity, manageability, and viability under technical conditions, which can in principle be accomplished by appropriate immobilization. Here, we report the identification of carrier material allowing exceptionally efficient adsorptive binding of Escherichia coli whole cells hosting catalytically active carbonyl reductase from Candida parapsilosis (CPCR2). With the immobilizates, composite formation with both hydrophobic and hydrophilized silicone was achieved, yielding advanced silCoat-material and HYsilCoat-material, respectively. HYsilCoat-whole cells were viable preparations with a cell loading up to 400 mg(E. coli) · g(-1)(carrier) and considerably lower leaching than native immobilizates. SilCoat-whole cells performed particularly well in neat substrate exhibiting distinctly increased catalytic activity.

Strain-specific differences in pili formation and the interaction of Corynebacterium diphtheriae with host cells

PubMed Central

2010-01-01

Background Corynebacterium diphtheriae, the causative agent of diphtheria, is well-investigated in respect to toxin production, while little is known about C. diphtheriae factors crucial for colonization of the host. In this study, we investigated strain-specific differences in adhesion, invasion and intracellular survival and analyzed formation of pili in different isolates. Results Adhesion of different C. diphtheriae strains to epithelial cells and invasion of these cells are not strictly coupled processes. Using ultrastructure analyses by atomic force microscopy, significant differences in macromolecular surface structures were found between the investigated C. diphtheriae strains in respect to number and length of pili. Interestingly, adhesion and pili formation are not coupled processes and also no correlation between invasion and pili formation was found. Using RNA hybridization and Western blotting experiments, strain-specific pili expression patterns were observed. None of the studied C. diphtheriae strains had a dramatic detrimental effect on host cell viability as indicated by measurements of transepithelial resistance of Detroit 562 cell monolayers and fluorescence microscopy, leading to the assumption that C. diphtheriae strains might use epithelial cells as an environmental niche supplying protection against antibodies and macrophages. Conclusions The results obtained suggest that it is necessary to investigate various isolates on a molecular level to understand and to predict the colonization process of different C. diphtheriae strains. PMID:20942914

Titan Cell Production Enhances the Virulence of Cryptococcus neoformans

PubMed Central

Crabtree, Juliet N.; Okagaki, Laura H.; Wiesner, Darin L.; Strain, Anna K.; Nielsen, Judith N.

2012-01-01

Infection with Cryptococcus neoformans begins when desiccated yeast cells or spores are inhaled and lodge in the alveoli of the lungs. A subset of cryptococcal cells in the lungs differentiate into enlarged cells, referred to as titan cells. Titan cells can be as large as 50 to 100 μm in diameter and exhibit a number of features that may affect interactions with host immune defenses. To characterize the effect of titan cell formation on the host-pathogen interaction, we utilized a previously described C. neoformans mutant, the gpr4Δ gpr5Δ mutant, which has minimal titan cell production in vivo. The gpr4Δ gpr5Δ mutant strain had attenuated virulence, a lower CFU, and reduced dissemination compared to the wild-type strain. Titan cell production by the wild-type strain also resulted in increased eosinophil accumulation and decreased phagocytosis in the lungs compared to those with the gpr4Δ gpr5Δ mutant strain. Phagocytosed cryptococcal cells exhibited less viability than nonphagocytosed cells, which potentially explains the reduced cell survival and overall attenuation of virulence in the absence of titan cells. These data show that titan cell formation is a novel virulence factor in C. neoformans that promotes establishment of the initial pulmonary infection and plays a key role in disease progression. PMID:22890995

Titan cell production enhances the virulence of Cryptococcus neoformans.

PubMed

Crabtree, Juliet N; Okagaki, Laura H; Wiesner, Darin L; Strain, Anna K; Nielsen, Judith N; Nielsen, Kirsten

2012-11-01

Infection with Cryptococcus neoformans begins when desiccated yeast cells or spores are inhaled and lodge in the alveoli of the lungs. A subset of cryptococcal cells in the lungs differentiate into enlarged cells, referred to as titan cells. Titan cells can be as large as 50 to 100 μm in diameter and exhibit a number of features that may affect interactions with host immune defenses. To characterize the effect of titan cell formation on the host-pathogen interaction, we utilized a previously described C. neoformans mutant, the gpr4Δ gpr5Δ mutant, which has minimal titan cell production in vivo. The gpr4Δ gpr5Δ mutant strain had attenuated virulence, a lower CFU, and reduced dissemination compared to the wild-type strain. Titan cell production by the wild-type strain also resulted in increased eosinophil accumulation and decreased phagocytosis in the lungs compared to those with the gpr4Δ gpr5Δ mutant strain. Phagocytosed cryptococcal cells exhibited less viability than nonphagocytosed cells, which potentially explains the reduced cell survival and overall attenuation of virulence in the absence of titan cells. These data show that titan cell formation is a novel virulence factor in C. neoformans that promotes establishment of the initial pulmonary infection and plays a key role in disease progression.

Cytokine Diedel and a viral homologue suppress the IMD pathway in Drosophila.

PubMed

Lamiable, Olivier; Kellenberger, Christine; Kemp, Cordula; Troxler, Laurent; Pelte, Nadège; Boutros, Michael; Marques, Joao Trindade; Daeffler, Laurent; Hoffmann, Jules A; Roussel, Alain; Imler, Jean-Luc

2016-01-19

Viruses are obligatory intracellular parasites that suffer strong evolutionary pressure from the host immune system. Rapidly evolving viral genomes can adapt to this pressure by acquiring genes that counteract host defense mechanisms. For example, many vertebrate DNA viruses have hijacked cellular genes encoding cytokines or cytokine receptors to disrupt host cell communication. Insect viruses express suppressors of RNA interference or apoptosis, highlighting the importance of these cell intrinsic antiviral mechanisms in invertebrates. Here, we report the identification and characterization of a family of proteins encoded by insect DNA viruses that are homologous to a 12-kDa circulating protein encoded by the virus-induced Drosophila gene diedel (die). We show that die mutant flies have shortened lifespan and succumb more rapidly than controls when infected with Sindbis virus. This reduced viability is associated with deregulated activation of the immune deficiency (IMD) pathway of host defense and can be rescued by mutations in the genes encoding the homolog of IKKγ or IMD itself. Our results reveal an endogenous pathway that is exploited by insect viruses to modulate NF-κB signaling and promote fly survival during the antiviral response.

In Vitro Activity of Manuka Honey and Polyhexamethylene Biguanide on Filamentous Fungi and Toxicity to Human Cell Lines

PubMed Central

Yabes, Joseph M.; White, Brian K.; Murray, Clinton K.; Sanchez, Carlos J.; Mende, Katrin; Beckius, Miriam L.; Zera, Wendy C.; Wenke, Joseph C.; Akers, Kevin S.

2016-01-01

Soft-tissue invasive fungal infections are increasingly recognized as significant entities directly contributing to morbidity and mortality. They complicate clinical care, requiring aggressive surgical debridement and systemic antifungal therapy. To evaluate new topical approaches to therapy, we examined the antifungal activity and cytotoxicity of Manuka Honey (MH) and polyhexamethylene biguanide (PHMB). The activities of multiple concentrations of MH (40%, 60%, 80%) and PHMB (0.01%, 0.04%, 0.1%) against 13 clinical mold isolates were evaluated using a time-kill assay between 5 min and 24 h. Concentrations were selected to represent current clinical use. Cell viability was examined in parallel for human epidermal keratinocytes, dermal fibroblasts and osteoblasts, allowing determination of the 50% viability (LD50) concentration. Antifungal activity of both agents correlated more closely with exposure time than concentration. Exophiala and Fusarium growth was completely suppressed at 5 min for all PHMB concentrations, and at 12 and 6 h, respectively, for all MH concentrations. Only Lichtheimia had persistent growth to both agents at 24 h. Viability assays displayed concentration-and time-dependent toxicity for PHMB. For MH, exposure time predicted cytotoxicity only when all cell types were analyzed in aggregate. This study demonstrates that MH and PHMB possess primarily time-dependent antifungal activity, but also exert in vitro toxicity on human cells which may limit clinical use. Further research is needed to determine ideal treatment strategies to optimize antifungal activity against molds while limiting cytotoxicity against host tissues in vivo. PMID:27601610

Supplementation of adjuvants for increasing the nutritive value and cell viability of probiotic fermented milk beverage.

PubMed

Shobharani, P; Agrawal, Renu

2009-01-01

Probiotic are microorganisms that, upon ingestion in adequate amounts, exert a beneficial effect on the host. In the present work, the potent probiotic Leuconostoc mesenteroides was used as a starter culture in the preparation of fermented milk beverage. The product was analyzed for protein, titrable acidity, fat, total sugar, fatty acids and minerals. The viability of culture and nutrition in the product was further enhanced with supplementation of adjuvants like tryptone, casein hydrolysate, cysteine hydrochloride and ascorbic acid. After 5 days, maximum viability was observed on supplementation of tryptone (100 mg/l). The protein content was enhanced by 1.1-fold in the presence of tryptone (100 mg/l) as compared with control after 5 days of storage. Fermented milk supplemented with tryptone (100 mg/l) showed maximum bioavailability of the minerals like iron (92.05%), zinc (95.02%) and magnesium (92.04%) as compared with control. The increase in the composition of beneficial fatty acids on supplementation of adjuvants supports the therapeutic value of the product.

Phages of Lactobacillus casei/paracasei: response to environmental factors and interaction with collection and commercial strains.

PubMed

Capra, M L; Quiberoni, A; Reinheimer, J

2006-02-01

To investigate the influence of several environmental factors on the viability and cell-adsorption for two Lactobacillus casei/paracasei bacteriophages (PL-1 and J-1). Both phages showed a remarkably high specificity of species, sharing similar host spectra. Two phages and four sensitive strains were used to conform five phage/strain systems. Each showed a particular behaviour (burst size: ranging from 32 to 160 PFU/infective centre; burst time: 120-240 min and latent time: 5-90 min). For both phages, the viability was not significantly affected from pH 4 to 11 (room temperature) and from pH 5 to 10 (37 degrees C). Adsorption rates were not influenced by calcium ions, but decreased after the thermal inactivation of cells. Adsorption rates were high between 0 and 50 degrees C with maximum values at 30 degrees C and pH 6. System PL-1/Lact. paracasei A showed noticeable differences in comparison with the others, being times required to reach 90% of adsorption of 4 h and lower than 45 min, respectively. The data obtained in this work demonstrated that environmental parameters can influence the viability and cell adsorption rates of Lact. casei/paracasei phages. The extent of this influence was phage dependent. This work contributes to the enlargement of the currently scarce knowledge of phages of probiotic bacteria.

Docosahexaenoic acid attenuates oxidative stress and protects human gingival fibroblasts against cytotoxicity induced by hydrogen peroxide and butyric acid.

PubMed

Zgorzynska, Emilia; Wierzbicka-Ferszt, Anita; Dziedzic, Barbara; Witusik-Perkowska, Monika; Zwolinska, Anna; Janas, Anna; Walczewska, Anna

2015-01-01

The oxidative burst of the host cells associated with bacterial pathogen infection contributes to the destruction of periodontal tissue. The present study investigates the effect of docosahexaenoic acid (DHA) on human gingival fibroblast (HGF) viability and ROS generation. The cell viability by MTT assay, ROS level using H2DCF-DA probe, and protein thiol content were measured in HGFs after 24h preincubation with different concentrations of DHA followed by treatment with H2O2. The cell death rate was determined by Annexin V/propidium iodide staining, and mitochondrial membrane potential (ΔΨm) was examined by MitoTracker Red probe in H2O2- and butyric acid-treated HGFs. The fatty acid composition of plasma membranes after incubation with DHA was determined by gas chromatography mass spectrometry. DHA preincubation in a dose-dependent manner increased the viability of HGFs exposed to H2O2 and decreased ROS generation compared to the control cells. In HGFs preincubated with 30μM DHA, the ΔΨm significantly increased in both H2O2- and butyric acid-treated cells. Moreover, incubation with DHA preserved the protein thiol level as effectively as N-acetylcysteine. Application of 50μM DHA increased the quantity of viable cells, decreased the number of necrotic cells after H2O2 treatment, and protected HGFs from apoptosis induced by butyric acid. DHA in the plasma membranes of these HGFs represented about 6% of the total amount of fatty acids. These results demonstrate that enrichment of HGFs with DHA reduces ROS generation and enhances the mitochondrial membrane potential protecting the fibroblasts against cytotoxic factors. Copyright © 2014 Elsevier Ltd. All rights reserved.

Characterisation of the Xenogeneic Immune Response to Microencapsulated Fetal Pig Islet-Like Cell Clusters Transplanted into Immunocompetent C57BL/6 Mice

PubMed Central

Ratnapala, Sabina; Foster, Jayne; Vaghjiani, Vijesh; Manuelpillai, Ursula; Tuch, Bernard E.

2013-01-01

Xenotransplantation of microencapsulated fetal pig islet-like cell clusters (FP ICCs) offers a potential cellular therapy for type 1 diabetes. Although microcapsules prevent direct contact of the host immune system with the xenografted tissue, poor graft survival is still an issue. This study aimed to characterise the nature of the host immune cells present on the engrafted microcapsules and effects on encapsulated FP ICCs that were transplanted into immunocompetent mice. Encapsulated FP ICCs were transplanted into the peritoneal cavity of C57BL/6 mice. Grafts retrieved at days 1, 3, 7, 14 and 21 post-transplantation were analysed for pericapsular fibrotic overgrowth (PFO), cell viability, intragraft porcine gene expression, macrophages, myofibroblasts and intraperitoneal murine cytokines. Graft function was assessed ex vivo by insulin secretion studies. Xenogeneic immune response to encapsulated FP ICCs was associated with enhanced intragraft mRNA expression of porcine antigens MIP-1α, IL-8, HMGB1 and HSP90 seen within the first two weeks post-transplantation. This was associated with the recruitment of host macrophages, infiltration of myofibroblasts and collagen deposition leading to PFO which was evident from day 7 post-transplantation. This was accompanied by a decrease in cell viability and loss of FP ICC architecture. The only pro-inflammatory cytokine detected in the murine peritoneal flushing was TNF-α with levels peaking at day 7 post transplantation. This correlated with the onset of PFO at day 7 implying activated macrophages as its source. The anti-inflammatory cytokines detected were IL-5 and IL-4 with levels peaking at days 1 and 7, respectively. Porcine C-peptide was undetectable at all time points post-transplantation. PFO was absent and murine intraperitoneal cytokines were undetectable when empty microcapsules were transplanted. In conclusion, this study demonstrated that the macrophages are direct effectors of the xenogeneic immune response to encapsulated FP ICCs leading to PFO mediated by a combination of both pro- and anti-inflammatory cytokines. PMID:23554983

Thiazolino 2-Pyridone Amide Inhibitors of Chlamydia trachomatis Infectivity.

PubMed

Good, James A D; Silver, Jim; Núñez-Otero, Carlos; Bahnan, Wael; Krishnan, K Syam; Salin, Olli; Engström, Patrik; Svensson, Richard; Artursson, Per; Gylfe, Åsa; Bergström, Sven; Almqvist, Fredrik

2016-03-10

The bacterial pathogen Chlamydia trachomatis is a global health burden currently treated with broad-spectrum antibiotics which disrupt commensal bacteria. We recently identified a compound through phenotypic screening that blocked infectivity of this intracellular pathogen without host cell toxicity (compound 1, KSK 120). Herein, we present the optimization of 1 to a class of thiazolino 2-pyridone amides that are highly efficacious (EC50 ≤ 100 nM) in attenuating infectivity across multiple serovars of C. trachomatis without host cell toxicity. The lead compound 21a exhibits reduced lipophilicity versus 1 and did not affect the growth or viability of representative commensal flora at 50 μM. In microscopy studies, a highly active fluorescent analogue 37 localized inside the parasitiphorous inclusion, indicative of a specific targeting of bacterial components. In summary, we present a class of small molecules to enable the development of specific treatments for C. trachomatis.

Survival and persistence of fecal host-specific Bacteroidales cells and their DNA assessed by PMA-qPCR

NASA Astrophysics Data System (ADS)

Bae, S.; Bombardelli, F.; Wuertz, S.

2008-12-01

Understanding and managing microbial pollutions in water is one of the foremost challenges of establishing effective managements and remediation strategies to impaired water bodies polluted by uncharacterized fecal sources. Quantitative microbial source tracking (MST) approaches using fecal Bacteroidales and quantitative PCR (qPCR) assays to measure gene copies of host-specific 16S rRNA genetic markers are promising because they can allow for identifying and quantifying fecal loadings from a particular animal host and understanding the fate and transport of host-specific Bacteroidales over a range of conditions in water bodies. Similar to the case of traditional fecal indicator bacteria, a relatively long persistence of target DNA may hamper applied MST studies, if genetic markers cannot be linked to recent fecal pollution in water. We report a successful approach to removing the qPCR signal derived from free DNA and dead host-specific Bacteroidales cells by selectively binding the DNA and consequently inhibiting PCR amplification using light- activated propidium monoazide (PMA). Optimal PMA-qPCR conditions were determined as 100 µM of PMA concentration and a 10-min light exposure time at different solids concentrations in order to mimic a range of water samples. Under these conditions, PMA-qPCR resulted in the selective exclusion of DNA from heat- treated cells of non-culturable Bacteroidales in human feces and wastewater influent and effluent samples. Also, the persistence of feces-derived host-specific Bacteroidales DNA and their cells (determined by universal, human-, cow- and dog-specific Bacteroidales qPCR assays) in seawater was investigated in microcosms at environmental conditions. The average T99 (two log reduction) value for host-specific viable Bacteroidales cells was 28 h, whereas that for total host-specific Bacteroidales DNA was 177 h. Natural sunlight did not have a strong influence on the fate of fecal Bacteroidales cells and their DNA, presumably because the presence of oxygen significantly affected the viability and persistence of these obligate anaerobes. In conclusion, measuring Bacteroidales DNA in viable cells is recommended in applied MST studies because extracellular Bacteroidales DNA persists longer in the environment. The methods and results presented are helpful to improve the accuracy of MST applications, to develop a model of fate and transport of host-specific Bacteroidales, and to implement management practices to protect water quality.

Preferential silent survival of intracellular bacteria in hemoglobin-primed macrophages.

PubMed

Subramanian, Karthik; Winarsih, Imelda; Keerthani, Chandrakumaran; Ho, Bow; Ding, Jeak Ling

2014-01-01

Hemolysis releases hemoglobin (Hb), a prooxidant, into circulation. While the heme iron is a nutrient for the invading pathogens, it releases ROS, which is both microbicidal and cytotoxic, making it a double-edged sword. Previously, we found a two-pass detoxification mechanism involving the endocytosis of Hb into monocytes in collaboration with vascular endothelial cells to overcome oxidative damage. This prompted us to examine the effect of Hb priming on host cell viability and intracellular bacterial clearance during a hemolytic infection. Here, we demonstrate that Hb-primed macrophages harbor a higher intracellular bacterial load but with suppressed apoptosis. p-ERK and p-p38 MAPK were significantly downregulated, with concomitant impairment of Bax and downstream caspases. The Hb-primed cells harboring intracellular bacteria upregulated anti-inflammatory IL-10 and downregulated proinflammatory TNF-α, which further enhanced the infectivity of the neighboring cells. Our findings suggest that opportunistic intracellular pathogens exploit the Hb-scavenging machinery of the host to silently persist within the circulating phagocytes by suppressing apoptosis while escaping immune surveillance. © 2014 S. Karger AG, Basel.

Toxoplasma gondii infection confers resistance against BimS-induced apoptosis by preventing the activation and mitochondrial targeting of pro-apoptotic Bax.

PubMed

Hippe, Diana; Weber, Arnim; Zhou, Liying; Chang, Donald C; Häcker, Georg; Lüder, Carsten G K

2009-10-01

In order to accomplish their life style, intracellular pathogens, including the apicomplexan Toxoplasma gondii, subvert the innate apoptotic response of infected host cells. However, the precise mechanisms of parasite interference with the mitochondrial apoptotic pathway remain unknown. Here, we used the conditional expression of the BH3-only protein Bim(S) to pinpoint the interaction of T. gondii with the intrinsic pathway of apoptosis. Infection of epithelial cells with T. gondii dose-dependently abrogated Bim(S)-triggered release of cytochrome c from host-cell mitochondria into the cytosol, induction of activity of caspases 3, 7 and 9, and chromatin condensation. Furthermore, inhibition of apoptosis in parasite-infected lymphocytes counteracted death of Toxoplasma-infected host cells. Although total cellular levels and mitochondrial targeting of Bim(S) was not altered by the infection, the activation of pro-apoptotic effector proteins Bax and Bak was strongly impaired. Inhibition of Bax and Bak activation by T. gondii was seen with regard to their conformational changes, the cytosol-to-mitochondria targeting and the oligomerization of Bax but not their cellular protein levels. Blockade of Bax and Bak activation was not mediated by the upregulation of anti-apoptotic Bcl-2-like proteins following infection. Further, the BH3-mimetic ABT-737 failed to overcome the Toxoplasma-imposed inhibition of Bim(S)-triggered apoptosis. These results indicate that T. gondii targets activation of pro-apoptotic Bax and Bak to inhibit the apoptogenic function of mitochondria and to increase host-cell viability.

Antibiotic free selection for the high level biosynthesis of a silk-elastin-like protein

PubMed Central

Barroca, Mário; Rodrigues, Paulo; Sobral, Rómulo; Costa, M. Manuela R.; Chaves, Susana R.; Machado, Raul; Casal, Margarida; Collins, Tony

2016-01-01

Silk-elastin-like proteins (SELPs) are a family of genetically engineered recombinant protein polymers exhibiting mechanical and biological properties suited for a wide range of applications in the biomedicine and materials fields. They are being explored as the next generation of biomaterials but low productivities and use of antibiotics during production undermine their economic viability and safety. We have developed an industrially relevant, scalable, fed-batch process for the high level production of a novel SELP in E. coli in which the commonly used antibiotic selection marker of the expression vector is exchanged for a post segregational suicide system, the separate-component-stabilisation system (SCS). SCS significantly augments SELP productivity but also enhances the product safety profile and reduces process costs by eliminating the use of antibiotics. Plasmid content increased following induction but no significant differences in plasmid levels were discerned when using SCS or the antibiotic selection markers under the controlled fed-batch conditions employed. It is suggested that the absence of competing plasmid-free cells improves host cell viability and enables increased productivity with SCS. With the process developed, 12.8 g L−1 purified SELP was obtained, this is the highest SELP productivity reported to date and clearly demonstrates the commercial viability of these promising polymers. PMID:27982135

Corynebacterium diphtheriae invasion-associated protein (DIP1281) is involved in cell surface organization, adhesion and internalization in epithelial cells

PubMed Central

2010-01-01

Background Corynebacterium diphtheriae, the causative agent of diphtheria, is well-investigated in respect to toxin production, while little is known about C. diphtheriae factors crucial for colonization of the host. In this study, we investigated the function of surface-associated protein DIP1281, previously annotated as hypothetical invasion-associated protein. Results Microscopic inspection of DIP1281 mutant strains revealed an increased size of the single cells in combination with an altered less club-like shape and formation of chains of cells rather than the typical V-like division forms or palisades of growing C. diphtheriae cells. Cell viability was not impaired. Immuno-fluorescence microscopy, SDS-PAGE and 2-D PAGE of surface proteins revealed clear differences of wild-type and mutant protein patterns, which were verified by atomic force microscopy. DIP1281 mutant cells were not only altered in shape and surface structure but completely lack the ability to adhere to host cells and consequently invade these. Conclusions Our data indicate that DIP1281 is predominantly involved in the organization of the outer surface protein layer rather than in the separation of the peptidoglycan cell wall of dividing bacteria. The adhesion- and invasion-negative phenotype of corresponding mutant strains is an effect of rearrangements of the outer surface. PMID:20051108

Identification and functional analysis of choline transporter in tongue cancer: A novel molecular target for tongue cancer therapy.

PubMed

Nishiyama, Ryohta; Nagashima, Fumiaki; Iwao, Beniko; Kawai, Yuiko; Inoue, Kana; Midori, Arisa; Yamanaka, Tsuyoshi; Uchino, Hiroyuki; Inazu, Masato

2016-06-01

We examined the functional characteristics of choline uptake in human tongue carcinoma using the cell line HSC-3. Furthermore, we explored the possible correlation between the inhibition of choline uptake and apoptotic cell death. Both choline transporter-like protein 1 (CTL1) and CTL2 mRNAs and proteins were expressed, and were located in plasma membrane and mitochondria, respectively. Choline uptake was saturable and mediated by a single transport system, which is pH-dependent. Several cationic drugs inhibited cell viability and [(3)H]choline uptake. Choline uptake inhibitors and choline deficiency inhibited cell viability and increased caspase-3/7 activity. We conclude that extracellular choline is mainly transported via a CTL1 that relies on a directed H(+) gradient as a driving force. The functional inhibition of CTL1 by cationic drugs could promote apoptotic cell death. Furthermore, CTL2 may be the major site for the control of choline oxidation in mitochondria and hence for the supply of endogenous betaine and S-adenosyl methionine, which serves as a major methyl donor. Identification of this CTL1- and CTL2-mediated choline transport system provides a potential new target for tongue cancer therapy. Copyright © 2016 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

Alphavirus production is inhibited in neurofibromin 1-deficient cells through activated RAS signalling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kolokoltsova, Olga A.; Domina, Aaron M.; Kolokoltsov, Andrey A.

2008-07-20

Virus-host interactions essential for alphavirus pathogenesis are poorly understood. To address this shortcoming, we coupled retrovirus insertional mutagenesis and a cell survival selection strategy to generate clonal cell lines broadly resistant to Sindbis virus (SINV) and other alphaviruses. Resistant cells had significantly impaired SINV production relative to wild-type (WT) cells, although virus binding and fusion events were similar in both sets of cells. Analysis of the retroviral integration sites identified the neurofibromin 1 (NF1) gene as disrupted in alphavirus-resistant cell lines. Subsequent analysis indicated that expression of NF1 was significantly reduced in alphavirus-resistant cells. Importantly, independent down-regulation of NF1 expressionmore » in WT HEK 293 cells decreased virus production and increased cell viability during SINV infection, relative to infected WT cells. Additionally, we observed hyperactive RAS signalling in the resistant HEK 293 cells, which was anticipated because NF1 is a negative regulator of RAS. Expression of constitutively active RAS (HRAS-G12V) in a WT HEK 293 cell line resulted in a marked delay in virus production, compared with infected cells transfected with parental plasmid or dominant-negative RAS (HRAS-S17N). This work highlights novel host cell determinants required for alphavirus pathogenesis and suggests that RAS signalling may play an important role in neuronal susceptibility to SINV infection.« less

Retinoids, retinoid analogs, and lactoferrin interact and differentially affect cell viability of 2 bovine mammary cell types in vitro.

PubMed

Wang, Y; Baumrucker, C R

2010-07-01

Two bovine mammary cell types (BME-UV1 and MeBo cells) were used to evaluate the effect of natural retinoids, retinoid analogs, and bovine lactoferrin (bLf) on cell viability in vitro. Experiments with Alamar Blue showed a linear relationship between fluorescence and cell viability index. The BME-UV1 cells exhibited twice the metabolic activity but required half the doubling time of the MeBo cells. The BME-UV1 cells were very sensitive to all-trans retinoic acid (atRA) inhibition of cell viability (P<0.05) and exhibited a dose-dependent inhibition with 9-cisRA (9cRA; P<0.05). The MeBo cells exhibited some inhibition with these natural ligands (P<0.05), but they were not as sensitive. The addition of bLf had similar inhibitory effects (P<0.05) on cell viability of the 2 mammary cell types. Applications of RA receptor (RAR) agonist indicated that the stimulation of the RAR in both mammary cell types was highly effective in inhibition of cell viability (P<0.05), whereas the application of an RAR antagonist stimulated MeBo cell viability (P<0.05) and inhibited BME-UV1 cell viability (P<0.05). Finally, the use of the RAR antagonist in conjunction with bLf indicated a rescue of the bLf effect in the MeBo cells, suggesting that bLf is acting through the RAR receptor. Conversely, bLf reverted inhibition of cell viability by 9cRA in the BME-UV1 cell type (P<0.05). We conclude that RAR interaction in bovine mammary cell types regulates cell viability in vitro; we hypothesize that the natural ligands mediate regulation of bovine mammary cell viability in vivo and that bLf can either enhance or reverse the retinoid-induced inhibition of cell viability, depending on the type of bovine mammary cell studied.

Morphological observation and analysis using automated image cytometry for the comparison of trypan blue and fluorescence-based viability detection method.

PubMed

Chan, Leo Li-Ying; Kuksin, Dmitry; Laverty, Daniel J; Saldi, Stephanie; Qiu, Jean

2015-05-01

The ability to accurately determine cell viability is essential to performing a well-controlled biological experiment. Typical experiments range from standard cell culturing to advanced cell-based assays that may require cell viability measurement for downstream experiments. The traditional cell viability measurement method has been the trypan blue (TB) exclusion assay. However, since the introduction of fluorescence-based dyes for cell viability measurement using flow or image-based cytometry systems, there have been numerous publications comparing the two detection methods. Although previous studies have shown discrepancies between TB exclusion and fluorescence-based viability measurements, image-based morphological analysis was not performed in order to examine the viability discrepancies. In this work, we compared TB exclusion and fluorescence-based viability detection methods using image cytometry to observe morphological changes due to the effect of TB on dead cells. Imaging results showed that as the viability of a naturally-dying Jurkat cell sample decreased below 70 %, many TB-stained cells began to exhibit non-uniform morphological characteristics. Dead cells with these characteristics may be difficult to count under light microscopy, thus generating an artificially higher viability measurement compared to fluorescence-based method. These morphological observations can potentially explain the differences in viability measurement between the two methods.

Cryptococcus neoformans-induced macrophage lysosome damage crucially contributes to fungal virulence1

PubMed Central

Davis, Michael J.; Eastman, Alison J.; Qiu, Yafeng; Gregorka, Brian; Kozel, Thomas R.; Osterholzer, John J.; Curtis, Jeffrey L.; Swanson, Joel A.; Olszewski, Michal A.

2015-01-01

Upon ingestion by macrophages, Cryptococcus neoformans (Cn) can survive and replicate intracellularly unless the macrophages become classically activated. The mechanism enabling intracellular replication is not fully understood; neither are the mechanisms which allow classical activation to counteract replication. Cn-induced lysosome damage was observed in infected murine bone marrow-derived macrophages, increased with time and required yeast viability. To demonstrate lysosome damage in the infected host, we developed a novel flow-cytometric method for measuring lysosome damage. Increased lysosome damage was found in Cn-containing lung cells compared to Cn–free cells. Among Cn-containing myeloid cells, recently recruited cells displayed lower damage than resident cells, consistent with the protective role of recruited macrophages. The magnitude of lysosome damage correlated with increased Cn replication. Experimental induction of lysosome damage increased Cn replication. Activation of macrophages with IFN-γ abolished macrophage lysosome damage and enabled increased killing of Cn. We conclude that induction of lysosome damage is an important Cn survival strategy and that classical activation of host macrophages counters replication by preventing damage. Thus, therapeutic strategies which decrease lysosomal damage, or increase resistance to such damage, could be valuable in treating cryptococcal infections. PMID:25637026

Candida albicans triggers interleukin-8 secretion by oral epithelial cells.

PubMed

Dongari-Bagtzoglou, A; Kashleva, H

2003-04-01

Oropharyngeal candidiasis is a frequent opportunistic infection associated with immunocompromised hosts. Candida albicans is the principal species responsible for this infection. Production of interleukin-8 (IL-8), by oral epithelial cells can be expected to play a major role in the recruitment and activation of professional phagocytes at the infected site. The purpose of this study was to determine whether C. albicans triggers secretion of IL-8 by oral epithelial cells in vitro and investigate mechanisms of host cell-fungal interactions that trigger such responses. Oral epithelial cell lines (SCC4, SCC15, and OKF6/TERT-2) as well as primary gingival epithelial cells were used. Epithelial cells were cocultured with C. albicans, strains SC5314, ATCC28366 or ATCC32077, for 24-48 hr, and supernatants were analyzed for IL-8 content by ELISA. A germination-deficient mutant (efg1/efg1 cph1/cph1), otherwise isogenic to strain SC5314, was used to assess the requirement for germination in triggering IL-8 responses. In order to ascertain whether direct contact of yeast with host cells is required to trigger cytokine production, epithelial cells were separated from yeast using cell culture inserts. To test whether IL-8 secretion is dependent on IL-1alpha activity, epithelial cells were challenged with viable C. albicans in the presence or absence of neutralizing anti-IL-1alpha antibody or IL-1ra, and IL-8 secretion was measured in the supernatants. All cell lines and primary cultures responded to C. albicans with an increase in IL-8 secretion. IL-8 responses were contact-dependent, strain-specific, required yeast viability and germination into hyphae, and were in part autoregulated by IL-1alpha. Copyright 2003 Elsevier Science Ltd.

Interaction of Bovine Peripheral Blood Polymorphonuclear Cells and Leptospira Species; Innate Responses in the Natural Bovine Reservoir Host

PubMed Central

Wilson-Welder, Jennifer H.; Frank, Ami T.; Hornsby, Richard L.; Olsen, Steven C.; Alt, David P.

2016-01-01

Cattle are the reservoir hosts of Leptospira borgpetersenii serovar Hardjo, and can also be reservoir hosts of other Leptospira species such as L. kirschneri, and Leptospira interrogans. As a reservoir host, cattle shed Leptospira, infecting other animals, including humans. Previous studies with human and murine neutrophils have shown activation of neutrophil extracellular trap or NET formation, and upregulation of inflammatory mediators by neutrophils in the presence of Leptospira. Humans, companion animals and most widely studied models of Leptospirosis are of acute infection, hallmarked by systemic inflammatory response, neutrophilia, and septicemia. In contrast, cattle exhibit chronic infection with few outward clinical signs aside from reproductive failure. Taking into consideration that there is host species variation in innate immunity, especially in pathogen recognition and response, the interaction of bovine peripheral blood polymorphonuclear cells (PMNs) and several Leptospira strains was evaluated. Studies including bovine-adapted strains, human pathogen strains, a saprophyte and inactivated organisms. Incubation of PMNs with Leptospira did induce slight activation of neutrophil NETs, greater than unstimulated cells but less than the quantity from E. coli P4 stimulated PMNs. Very low but significant from non-stimulated, levels of reactive oxygen peroxides were produced in the presence of all Leptospira strains and E. coli P4. Similarly, significant levels of reactive nitrogen intermediaries (NO2) was produced from PMNs when incubated with the Leptospira strains and greater quantities in the presence of E. coli P4. PMNs incubated with Leptospira induced RNA transcripts of IL-1β, MIP-1α, and TNF-α, with greater amounts induced by live organisms when compared to heat-inactivated leptospires. Transcript for inflammatory cytokine IL-8 was also induced, at similar levels regardless of Leptospira strain or viability. However, incubation of Leptospira strains with bovine PMNs did not affect Leptospira viability as measured by limiting dilution culture. This is in contrast to previously reported results of innate inflammatory activation by Leptospira in human and other animal models, or the activation and interaction of bovine PMNs with Escherichia coli and other bacterial pathogens. While it could be hypothesized that variations in innate receptor recognition, specifically variance in toll-like receptor 2, could underlie the observed reduction of activation in bovine PMNs, additional studies would be needed to explore this possibility. Reduction in neutrophil responses may help to establish nearly asymptomatic chronic Leptospira infection of cattle. This study emphasizes the importance of studying host-pathogen relationships in the appropriate species as extrapolation from other animal models may be incorrect and confounded by differences in the host responses. PMID:27486445

Human Embryonic Stem Cell-Derived Cardiomyocytes Regenerate Non-Human Primate Hearts

PubMed Central

Chong, James J.H.; Yang, Xiulan; Don, Creighton W.; Minami, Elina; Liu, Yen-Wen; Weyers, Jill J; Mahoney, William M.; Van Biber, Benjamin; Cook, Savannah M.; Palpant, Nathan J; Gantz, Jay; Fugate, James A.; Muskheli, Veronica; Gough, G. Michael; Vogel, Keith W.; Astley, Cliff A.; Hotchkiss, Charlotte E.; Baldessari, Audrey; Pabon, Lil; Reinecke, Hans; Gill, Edward A.; Nelson, Veronica; Kiem, Hans-Peter; Laflamme, Michael A.; Murry, Charles E.

2014-01-01

Pluripotent stem cells provide a potential solution to current epidemic rates of heart failure 1 by providing human cardiomyocytes to support heart regeneration 2. Studies of human embryonic stem cell-derived cardiomyocytes (hESC-CMs) in small animal models have shown favorable effects of this treatment 3–7. It remains unknown, however, whether clinical scale hESC-CMs transplantation is feasible, safe or can provide large-scale myocardial regeneration. Here we show that hESC-CMs can be produced at a clinical scale (>1 billion cells/batch) and cryopreserved with good viability. Using a non-human primate (NHP) model of myocardial ischemia-reperfusion, we show that that cryopreservation and intra-myocardial delivery of 1 billion hESC-CMs generates significant remuscularization of the infarcted heart. The hESC-CMs showed progressive but incomplete maturation over a three-month period. Grafts were perfused by host vasculature, and electromechanical junctions between graft and host myocytes were present within 2 weeks of engraftment. Importantly, grafts showed regular calcium transients that were synchronized to the host electrocardiogram, indicating electromechanical coupling. In contrast to small animal models 7, non-fatal ventricular arrhythmias were observed in hESC-CM engrafted primates. Thus, hESC-CMs can remuscularize substantial amounts of the infarcted monkey heart. Comparable remuscularization of a human heart should be possible, but potential arrhythmic complications need to be overcome. PMID:24776797

Sub-physiological oxygen levels optimal for growth and survival of human atrial cardiac stem cells.

PubMed

RajendranNair, Deepthi Sreerengam; Karunakaran, Jayakumar; Nair, Renuka R

2017-08-01

Cardiac stem cells reside in niches where the oxygen levels are close to 3%. For cytotherapy, cells are conventionally expanded in ambient oxygen (21% O 2 ) which represents hyperoxia compared to the oxygen tension of niches. Cardiosphere-derived cells (CDCs) are then transplanted to host tissue with lower-O 2 levels. The high-O 2 gradient can reduce the efficacy of cultured cells. Based on the assumption that minimizing injury due to O 2 gradients will enhance the yield of functionally efficient cells, CDCs were cultured in 3% O 2 and compared with cells maintained in ambient O 2 . CDCs were isolated from human right atrial explants and expanded in parallel in 21 and 3% oxygen and compared with regard to survival, proliferation, and retention of stemness. Increased cell viability even in the tenth passage and enhanced cardiosphere formation was observed in cells expanded in 3% O 2 . The cell yield from seven passages was fourfold higher for cells cultured in 3% O 2 . Preservation of stemness in hypoxic environment was evident from the proportion of c-kit-positive cells and reduced myogenic differentiation. Hypoxia promoted angiogenesis and reduced the tendency to differentiate to noncardiac lineages (adipocytes and osteocytes). Mimicking the microenvironment at transplantation, when shifted to 5% O 2 , viability and proliferation rate were significantly higher for CDCs expanded in 3% O 2 . Expansion of CDCs, from atria in sub-physiological oxygen, helps in obtaining a higher yield of healthy cells with better preservation of stem cell characteristics. The cells so cultured are expected to improve engraftment and facilitate myocardial regeneration.

Multiple reaction monitoring targeted LC-MS analysis of potential cell death marker proteins for increased bioprocess control.

PubMed

Albrecht, Simone; Kaisermayer, Christian; Reinhart, David; Ambrose, Monica; Kunert, Renate; Lindeberg, Anna; Bones, Jonathan

2018-05-01

The monitoring of protein biomarkers for the early prediction of cell stress and death is a valuable tool for process characterization and efficient biomanufacturing control. A representative set of six proteins, namely GPDH, PRDX1, LGALS1, CFL1, TAGLN2 and MDH, which were identified in a previous CHO-K1 cell death model using discovery LC-MS E was translated into a targeted liquid chromatography multiple reaction monitoring mass spectrometry (LC-MRM-MS) platform and verified. The universality of the markers was confirmed in a cell growth model for which three Chinese hamster ovary host cell lines (CHO-K1, CHO-S, CHO-DG44) were grown in batch culture in two different types of basal media. LC-MRM-MS was also applied to spent media (n = 39) from four perfusion biomanufacturing series. Stable isotope-labelled peptide analogues and a stable isotope-labelled monoclonal antibody were used for improved protein quantitation and simultaneous monitoring of the workflow reproducibility. Significant increases in protein concentrations were observed for all viability marker proteins upon increased dead cell numbers and allowed for discrimination of spent media with dead cell densities below and above 1 × 10 6  dead cells/mL which highlights the potential of the selected viability marker proteins in bioprocess control. Graphical abstract Overview of the LC-MRM-MS workflow for the determination of proteomic markers in conditioned media from the bioreactor that correlate with CHO cell death.

Optimized labeling of bone marrow mesenchymal cells with superparamagnetic iron oxide nanoparticles and in vivo visualization by magnetic resonance imaging

PubMed Central

2011-01-01

Background Stem cell therapy has emerged as a promising addition to traditional treatments for a number of diseases. However, harnessing the therapeutic potential of stem cells requires an understanding of their fate in vivo. Non-invasive cell tracking can provide knowledge about mechanisms responsible for functional improvement of host tissue. Superparamagnetic iron oxide nanoparticles (SPIONs) have been used to label and visualize various cell types with magnetic resonance imaging (MRI). In this study we performed experiments designed to investigate the biological properties, including proliferation, viability and differentiation capacity of mesenchymal cells (MSCs) labeled with clinically approved SPIONs. Results Rat and mouse MSCs were isolated, cultured, and incubated with dextran-covered SPIONs (ferumoxide) alone or with poly-L-lysine (PLL) or protamine chlorhydrate for 4 or 24 hrs. Labeling efficiency was evaluated by dextran immunocytochemistry and MRI. Cell proliferation and viability were evaluated in vitro with Ki67 immunocytochemistry and live/dead assays. Ferumoxide-labeled MSCs could be induced to differentiate to adipocytes, osteocytes and chondrocytes. We analyzed ferumoxide retention in MSCs with or without mitomycin C pretreatment. Approximately 95% MSCs were labeled when incubated with ferumoxide for 4 or 24 hrs in the presence of PLL or protamine, whereas labeling of MSCs incubated with ferumoxide alone was poor. Proliferative capacity was maintained in MSCs incubated with ferumoxide and PLL for 4 hrs, however, after 24 hrs it was reduced. MSCs incubated with ferumoxide and protamine were efficiently visualized by MRI; they maintained proliferation and viability for up to 7 days and remained competent to differentiate. After 21 days MSCs pretreated with mitomycin C still showed a large number of ferumoxide-labeled cells. Conclusions The efficient and long lasting uptake and retention of SPIONs by MSCs using a protocol employing ferumoxide and protamine may be applicable to patients, since both ferumoxides and protamine are approved for human use. PMID:21542946

Differential expression of Listeria monocytogenes virulence genes in mammalian host cells.

PubMed

Bubert, A; Sokolovic, Z; Chun, S K; Papatheodorou, L; Simm, A; Goebel, W

1999-03-01

We have used RT-PCR and GFP-mediated fluorescence to analyse the regulation of PrfA-dependent virulence genes of Listeria monocytogenes during proliferation in mammalian host cells. Our data show that most of the PrfA-regulated virulence genes are more efficiently expressed, as measured by transcript levels, when L. monocytogenes is grown in macrophages and macrophage-like cells rather than in epithelial cells, hepatocytes or endothelial cells. The promoters for hly and plcA are predominantly activated within the phagosomal compartment, while those for actA and inlC are predominantly activated in the host cell cytosol. Expression of actA and plcB precedes that of inlC after infection of epithelial cells and macrophages. Little transcription of inlA or inlB is observed in epithelial cells and there is only slightly more in macrophages. In both cell types the level of transcription of the inlAB operon is lower than is seen under extracellular growth conditions in rich media, which is compatible with the assumption that InlA and InlB are not required during intracellular growth of the bacteria. Activation of the PrfA-independent iap promoter is also low during intracellular growth, although the gene product (p60) is required for cell viability. The levels of the PrfA-dependent virulence gene transcripts do not correlate with the amount of prfA transcript present, which is low under all intracellular conditions analysed, suggesting that the prfA transcript is either highly unstable in bacteria that are growing intracellularly, or that the small amount of PrfA produced is highly activated by additional component(s).

An in vitro model of Mycobacterium leprae induced granuloma formation

PubMed Central

2013-01-01

Background Leprosy is a contagious and chronic systemic granulomatous disease caused by Mycobacterium leprae. In the pathogenesis of leprosy, granulomas play a key role, however, the mechanisms of the formation and maintenance of M. leprae granulomas are still not clearly understood. Methods To better understand the molecular physiology of M. leprae granulomas and the interaction between the bacilli and human host cells, we developed an in vitro model of human granulomas, which mimicked the in vivo granulomas of leprosy. Macrophages were differentiated from human monocytes, and infected with M. leprae, and then cultured with autologous human peripheral blood mononuclear cells (PBMCs). Results Robust granuloma-like aggregates were obtained only when the M. leprae infected macrophages were co-cultured with PBMCs. Histological examination showed M. leprae within the cytoplasmic center of the multinucleated giant cells, and these bacilli were metabolically active. Macrophages of both M1 and M2 types co-existed in the granuloma like aggregates. There was a strong relationship between the formation of granulomas and changes in the expression levels of cell surface antigens on macrophages, cytokine production and the macrophage polarization. The viability of M. leprae isolated from granulomas indicated that the formation of host cell aggregates benefited the host, but the bacilli also remained metabolically active. Conclusions A simple in vitro model of human M. leprae granulomas was established using human monocyte-derived macrophages and PBMCs. This system may be useful to unravel the mechanisms of disease progression, and subsequently develop methods to control leprosy. PMID:23782413

An in vitro model of Mycobacterium leprae induced granuloma formation.

PubMed

Wang, Hongsheng; Maeda, Yumi; Fukutomi, Yasuo; Makino, Masahiko

2013-06-20

Leprosy is a contagious and chronic systemic granulomatous disease caused by Mycobacterium leprae. In the pathogenesis of leprosy, granulomas play a key role, however, the mechanisms of the formation and maintenance of M. leprae granulomas are still not clearly understood. To better understand the molecular physiology of M. leprae granulomas and the interaction between the bacilli and human host cells, we developed an in vitro model of human granulomas, which mimicked the in vivo granulomas of leprosy. Macrophages were differentiated from human monocytes, and infected with M. leprae, and then cultured with autologous human peripheral blood mononuclear cells (PBMCs). Robust granuloma-like aggregates were obtained only when the M. leprae infected macrophages were co-cultured with PBMCs. Histological examination showed M. leprae within the cytoplasmic center of the multinucleated giant cells, and these bacilli were metabolically active. Macrophages of both M1 and M2 types co-existed in the granuloma like aggregates. There was a strong relationship between the formation of granulomas and changes in the expression levels of cell surface antigens on macrophages, cytokine production and the macrophage polarization. The viability of M. leprae isolated from granulomas indicated that the formation of host cell aggregates benefited the host, but the bacilli also remained metabolically active. A simple in vitro model of human M. leprae granulomas was established using human monocyte-derived macrophages and PBMCs. This system may be useful to unravel the mechanisms of disease progression, and subsequently develop methods to control leprosy.

How to design cell-based biosensors using the sol-gel process.

PubMed

Depagne, Christophe; Roux, Cécile; Coradin, Thibaud

2011-05-01

Inorganic gels formed using the sol-gel process are promising hosts for the encapsulation of living organisms and the design of cell-based biosensors. However, the possibility to use the biological activity of entrapped cells as a biological signal requires a good understanding and careful control of the chemical and physical conditions in which the organisms are placed before, during, and after gel formation, and their impact on cell viability. Moreover, it is important to examine the possible transduction methods that are compatible with sol-gel encapsulated cells. Through an updated presentation of the current knowledge in this field and based on selected examples, this review shows how it has been possible to convert a chemical technology initially developed for the glass industry into a biotechnological tool, with current limitations and promising specificities.

Global Screening of Antiviral Genes that Suppress Baculovirus Transgene Expression in Mammalian Cells.

PubMed

Wang, Chia-Hung; Naik, Nenavath Gopal; Liao, Lin-Li; Wei, Sung-Chan; Chao, Yu-Chan

2017-09-15

Although baculovirus has been used as a safe and convenient gene delivery vector in mammalian cells, baculovirus-mediated transgene expression is less effective in various mammalian cell lines. Identification of the negative regulators in host cells is necessary to improve baculovirus-based expression systems. Here, we performed high-throughput shRNA library screening, targeting 176 antiviral innate immune genes, and identified 43 host restriction factor genes in a human A549 lung carcinoma cell line. Among them, suppression of receptor interaction protein kinase 1 (RIP1, also known as RIPK1) significantly increased baculoviral transgene expression without resulting in significant cell death. Silencing of RIP1 did not affect viral entry or cell viability, but it did inhibit nuclear translocation of the IRF3 and NF-κB transcription factors. Also, activation of downstream signaling mediators (such as TBK1 and IRF7) was affected, and subsequent interferon and cytokine gene expression levels were abolished. Further, Necrostatin-1 (Nec-1)-an inhibitor of RIP1 kinase activity-dramatically increased baculoviral transgene expression in RIP1-silenced cells. Using baculovirus as a model system, this study presents an initial investigation of large numbers of human cell antiviral innate immune response factors against a "nonadaptive virus." In addition, our study has made baculovirus a more efficient gene transfer vector for some of the most frequently used mammalian cell systems.

In Vivo Long-Term Tracking of Neural Stem Cells Transplanted into an Acute Ischemic Stroke model with Reporter Gene-Based Bimodal MR and Optical Imaging.

PubMed

Zhang, Fang; Duan, Xiaohui; Lu, Liejing; Zhang, Xiang; Chen, Meiwei; Mao, Jiaji; Cao, Minghui; Shen, Jun

2017-10-01

Transplantation of neural stem cells (NSCs) is emerging as a new therapeutic approach for stroke. Real-time imaging of transplanted NSCs is essential for successful cell delivery, safety monitoring, tracking cell fate and function, and understanding the interactions of transplanted cells with the host environment. Magnetic resonance imaging (MRI) of magnetic nanoparticle-labeled cells has been the most widely used means to track stem cells in vivo. Nevertheless, it does not allow for the reliable discrimination between live and dead cells. Reporter gene-based MRI was considered as an alternative strategy to overcome this shortcoming. In this work, a class of lentiviral vector-encoding ferritin heavy chain (FTH) and enhanced green fluorescent protein (EGFP) was constructed to deliver reporter genes into NSCs. After these transgenic NSCs were transplanted into the contralateral hemisphere of rats with acute ischemic stroke, MRI and fluorescence imaging (FLI) were performed in vivo for tracking the fate of transplanted cells over a long period of 6 wk. The results demonstrated that the FTH and EGFP can be effectively and safely delivered to NSCs via the designed lentiviral vector. The distribution and migration of grafted stem cells could be monitored by bimodal MRI and FLI. FTH can be used as a robust MRI reporter for reliable reporting of the short-term viability of cell grafts, whereas its capacity for tracking the long-term viability of stem cells remains dependent on several confounding factors such as cell death and the concomitant reactive inflammation.

Detecting cell lysis using viscosity monitoring in E. coli fermentation to prevent product loss

PubMed Central

Newton, Joseph M.; Schofield, Desmond; Vlahopoulou, Joanna

2016-01-01

Monitoring the physical or chemical properties of cell broths to infer cell status is often challenging due to the complex nature of the broth. Key factors indicative of cell status include cell density, cell viability, product leakage, and DNA release to the fermentation broth. The rapid and accurate prediction of cell status for hosts with intracellular protein products can minimise product loss due to leakage at the onset of cell lysis in fermentation. This article reports the rheological examination of an industrially relevant E. coli fermentation producing antibody fragments (Fab'). Viscosity monitoring showed an increase in viscosity during the exponential phase in relation to the cell density increase, a relatively flat profile in the stationary phase, followed by a rapid increase which correlated well with product loss, DNA release and loss of cell viability. This phenomenon was observed over several fermentations that a 25% increase in broth viscosity (using induction‐point viscosity as a reference) indicated 10% product loss. Our results suggest that viscosity can accurately detect cell lysis and product leakage in postinduction cell cultures, and can identify cell lysis earlier than several other common fermentation monitoring techniques. This work demonstrates the utility of rapidly monitoring the physical properties of fermentation broths, and that viscosity monitoring has the potential to be a tool for process development to determine the optimal harvest time and minimise product loss. © 2016 The Authors. Biotechnology Progress published by Wiley Periodicals, Inc. on behalf of American Institute of Chemical Engineers, 32:1069–1076, 2016 PMID:27111912

A New Member of the Sin3 Family of Corepressors Is Essential for Cell Viability and Required for Retroelement Propagation in Fission Yeast

PubMed Central

Dang, Van Dinh; Benedik, Michael J.; Ekwall, Karl; Choi, Jeannie; Allshire, Robin C.; Levin, Henry L.

1999-01-01

Tf1 is a long terminal repeat (LTR)-containing retrotransposon that propagates within the fission yeast Schizosaccharomyces pombe. LTR-retrotransposons possess significant similarity to retroviruses and therefore serve as retrovirus models. To determine what features of the host cell are important for the proliferation of this class of retroelements, we screened for mutations in host genes that reduced the transposition activity of Tf1. We report here the isolation and characterization of pst1+, a gene required for Tf1 transposition. The predicted amino acid sequence of Pst1p possessed high sequence homology with the Sin3 family of proteins, known for their interaction with histone deacetylases. However, unlike the SIN3 gene of Saccharomyces cerevisiae, pst1+ is essential for cell viability. Immunofluorescence microscopy indicated that Pst1p was localized in the nucleus. Consistent with the critical role previously reported for Sin3 proteins in the histone acetylation process, we found that the growth of the strain with the pst1-1 allele was supersensitive to the specific histone deacetylase inhibitor trichostatin A. However, our analysis of strains with the pst1-1 mutation was unable to detect any changes in the acetylation of specific lysines of histones H3 and H4 as measured in bulk chromatin. Interestingly, the pst1-1 mutant strain produced wild-type levels of Tf1-encoded proteins and cDNA, indicating that the defect in transposition occurred after reverse transcription. The results of immunofluorescence microscopy showed that the nuclear localization of the Tf1 capsid protein was disrupted in the strain with the pst1-1 mutation, indicating an important role of pst1+ in modulating the nuclear import of Tf1 virus-like particles. PMID:10022921

In vitro effects of prostaglandin E2 on leucocytes from sticklebacks (Gasterosteus aculeatus) infected and not infected with the cestode Schistocephalus solidus.

PubMed

Kutyrev, Ivan A; Franke, Frederik; Büscher, Janine; Kurtz, Joachim; Scharsack, Jörn P

2014-12-01

Many helminth parasites have evolved strategies to evade the immune response of their hosts, which includes immunomodulation. Prostaglandin E2 (PGE2) is one of the best-described immunomodulators in mammalian helminth parasite infections. We hypothesized that also in teleost fish anti-helminthic immune responses are regulated via PGE2. We used a model system consisting of the tapeworm Schistocephalus solidus and its host, the three-spined stickleback (Gasterosteus aculeatus), to investigate in vitro effects of PGE2 on head kidney leucocytes (HKL) derived from sticklebacks that were experimentally infected with S. solidus. PGE2 was tested alone or in combination with either S. solidus antigens or bacterial lipopolysaccharides (LPS). After in vitro culture, cell viability and changes in leucocyte subpopulations (granulocytes to lymphocytes ratios) were monitored by flow cytometry and HKL were tested for their capacity to produce reactive oxygen species (ROS) with a chemiluminescence assay. In short term (2 h) HKL cultures PGE2 did not change the total numbers of live HKL, but the production of ROS decreased significantly with high (0.1 μmol L(-1)) PGE2 concentrations. In long-term (96 h) cultures high PGE2 concentrations induced a sharp decrease of leucocytes viability, while low (0.1 pmol L(-1)) and intermediate (0.1 nmol L(-1)) concentrations of PGE2 caused elevated leucocyte viability compared to controls. This coincided with reduced ROS production in cultures with high PGE2 and elevated ROS production in cultures with low PGE2. Granulocyte to lymphocyte ratios increased with high PGE2 concentrations alone and in combination with S. solidus antigens and LPS, most prominently with HKL from S. solidus infected sticklebacks. The present study supports the hypothesis that PGE2 might be an immunomodulator in tapeworm-fish parasite-host interactions. Copyright © 2014 Elsevier Ltd. All rights reserved.

miR-370 mimic inhibits replication of Japanese encephalitis virus in glioblastoma cells.

PubMed

Li, Wenjuan; Cheng, Peng; Nie, Shangdan; Cui, Wen

2016-01-01

Japanese encephalitis (JE) is one of the most severe viral infections of the central nervous system. No effective treatment for JE currently exists, because its pathogenesis remains largely unknown. The present study was designed to screen the potential microRNAs (miRNAs) involved in JE. Glioblastoma cells were collected, after being infected with the Japanese encephalitis virus (JEV). Total miRNAs were extracted and analyzed using an miRNA chip. One of the most severely affected miRNAs was selected, and the role of miR-370 in JEV infection was investigated. Cell viability and apoptosis of the host cells were evaluated. JEV replication was detected via analysis of gene E expression. Real-time polymerase chain reaction was used to determine the levels of endogenous miR-370 and expression of innate immunity-related genes. Following JEV infection, 114 miRNAs were affected, as evidenced by the miRNA chip. Among them, 30 miRNAs were upregulated and 84 were downregulated. The changes observed in five miRNAs were confirmed by real-time polymerase chain reaction. One of the significantly downregulated miRNAs was miR-370. Therefore, miR-370 mimic was transfected into the cells, following which the levels of endogenous miR-370 were significantly elevated. Concurrently, JEV replication was significantly reduced 24 hours after transfection of miR-370 mimic. Functionally, miR-370 mimic mitigated both JEV-induced apoptosis and the inhibition of host cell proliferation. Following JEV infection, interferon-β and nuclear factor-kappa B were upregulated, whereas miR-370 mimic prevented the upregulation of the genes induced by JEV infection. The present study demonstrated that miR-370 expression in host cells is downregulated following JEV infection, which further mediates innate immunity-related gene expression. Taken together, miR-370 mimic might be useful to prevent viral replication and infection-induced host cell injury.

The immunomodulatory properties of probiotic microorganisms beyond their viability (ghost probiotics: proposal of paraprobiotic concept).

PubMed

Taverniti, Valentina; Guglielmetti, Simone

2011-08-01

The probiotic approach represents a potentially effective and mild alternative strategy for the prevention and treatment of either inflammatory or allergic diseases. Several studies have shown that different bacterial strains can exert their probiotic abilities by influencing the host's immune system, thereby modulating immune responses. However, the emerging concern regarding safety problems arising from the extensive use of live microbial cells is enhancing the interest in non-viable microorganisms or microbial cell extracts, as they could eliminate shelf-life problems and reduce the risks of microbial translocation and infection. The purpose of this review is to provide an overview of the scientific literature concerning studies in which dead microbial cells or crude microbial cell fractions have been used as health-promoting agents. Particular attention will be given to the modulation of host immune responses. Possible mechanisms determining the effect on the immune system will also be discussed. Finally, in the light of the FAO/WHO definition of probiotics, indicating that the word 'probiotic' should be restricted to products that contain live microorganisms, and considering the scientific evidence indicating that inactivated microbes can positively affect human health, we propose the new term 'paraprobiotic' to indicate the use of inactivated microbial cells or cell fractions to confer a health benefit to the consumer.

RGDfK-Peptide Modified Alginate Scaffold for Cell Transplantation and Cardiac Neovascularization.

PubMed

Sondermeijer, Hugo P; Witkowski, Piotr; Seki, Tetsunori; van der Laarse, Arnoud; Itescu, Silviu; Hardy, Mark A

2018-05-01

Cell implantation for tissue repair is a promising new therapeutic strategy. Although direct injection of cells into tissue is appealing, cell viability and retention are not very good. Cell engraftment and survival following implantation are dependent on a sufficient supply of oxygen and nutrients through functional microcirculation as well as a suitable local microenvironment for implanted cells. In this study, we describe the development of a porous, biocompatible, three-dimensional (3D) alginate scaffold covalently modified with the synthetic cyclic RGDfK (Arg-Gly-Asp-D-Phe-Lys) peptide. Cyclic RGDfK peptide is protease resistant, highly stable in aqueous solutions, and has high affinity for cellular integrins. Cyclic RGDfK-modified alginate scaffolds were generated using a novel silicone sheet sandwich technique in combination with freeze-gelation, resulting in highly porous nonimmunogenic scaffolds that promoted both human and rodent cell survival in vitro, and neoangiogenesis in vivo. Two months following implantation in abdominal rectus muscles in rats, cyclic RGDfK-modified scaffolds were fully populated by host cells, especially microvasculature without an overt immune response or fibrosis, whereas unmodified control scaffolds did not show cell ingrowth. Importantly, modified scaffolds that were seeded with human mesenchymal precursor cells and were patched to the epicardial surface of infarcted myocardium induced myocardial neoangiogenesis and significantly improved cardiac function. In summary, purified cyclic RGDfK peptide-modified 3D alginate scaffolds are biocompatible and nonimmunogenic, enhance cell viability, promote angiogenesis, and may be used as a means to deliver cells to myocardial infarct areas to improve neovascularization and cardiac function.

Production of foot-and-mouth disease virus capsid proteins by the TEV protease.

PubMed

Puckette, Michael; Smith, Justin D; Gabbert, Lindsay; Schutta, Christopher; Barrera, José; Clark, Benjamin A; Neilan, John G; Rasmussen, Max

2018-06-10

Protective immunity to viral pathogens often includes production of neutralizing antibodies to virus capsid proteins. Many viruses produce capsid proteins by expressing a precursor polyprotein and related protease from a single open reading frame. The foot-and-mouth disease virus (FMDV) expresses a 3C protease (3Cpro) that cleaves a P1 polyprotein intermediate into individual capsid proteins, but the FMDV 3Cpro also degrades many host cell proteins and reduces the viability of host cells, including subunit vaccine production cells. To overcome the limitations of using the a wild-type 3Cpro in FMDV subunit vaccine expression systems, we altered the protease restriction sequences within a FMDV P1 polyprotein to enable production of FMDV capsid proteins by the Tobacco Etch Virus NIa protease (TEVpro). Separate TEVpro and modified FMDV P1 proteins were produced from a single open reading frame by an intervening FMDV 2A sequence. The modified FMDV P1 polyprotein was successfully processed by the TEVpro in both mammalian and bacterial cells. More broadly, this method of polyprotein production and processing may be adapted to other recombinant expression systems, especially plant-based expression. Published by Elsevier B.V.

MiRNA-124 is a link between measles virus persistent infection and cell division of human neuroblastoma cells.

PubMed

Naaman, Hila; Rall, Glenn; Matullo, Christine; Veksler-Lublinsky, Isana; Shemer-Avni, Yonat; Gopas, Jacob

2017-01-01

Measles virus (MV) infects a variety of lymphoid and non-lymphoid peripheral organs. However, in rare cases, the virus can persistently infect cells within the central nervous system. Although some of the factors that allow MV to persist are known, the contribution of host cell-encoded microRNAs (miRNA) have not been described. MiRNAs are a class of noncoding RNAs transcribed from genomes of all multicellular organisms and some viruses, which regulate gene expression in a sequence-specific manner. We have studied the contribution of host cell-encoded miRNAs to the establishment of MV persistent infection in human neuroblastoma cells. Persistent MV infection was accompanied by differences in the expression profile and levels of several host cell-encoded microRNAs as compared to uninfected cells. MV persistence infection of a human neuroblastoma cell line (UKF-NB-MV), exhibit high miRNA-124 expression, and reduced expression of cyclin dependent kinase 6 (CDK6), a known target of miRNA-124, resulting in slower cell division but not cell death. By contrast, acute MV infection of UKF-NB cells did not result in increased miRNA-124 levels or CDK6 reduction. Ectopic overexpression of miRNA-124 affected cell viability only in UKF-NB-MV cells, causing cell death; implying that miRNA-124 over expression can sensitize cells to death only in the presence of MV persistent infection. To determine if miRNA-124 directly contributes to the establishment of MV persistence, UKF-NB cells overexpressing miRNA-124 were acutely infected, resulting in establishment of persistently infected colonies. We propose that miRNA-124 triggers a CDK6-dependent decrease in cell proliferation, which facilitates the establishment of MV persistence in neuroblastoma cells. To our knowledge, this is the first report to describe the role of a specific miRNA in MV persistence.

Noninvasive Real-Time Assessment of Cell Viability in a Three-Dimensional Tissue.

PubMed

Mahfouzi, Seyed Hossein; Amoabediny, Ghassem; Doryab, Ali; Safiabadi-Tali, Seyed Hamid; Ghanei, Mostafa

2018-04-01

Maintaining cell viability within 3D tissue engineering scaffolds is an essential step toward a functional tissue or organ. Assessment of cell viability in 3D scaffolds is necessary to control and optimize tissue culture process. Monitoring systems based on respiration activity of cells (e.g., oxygen consumption) have been used in various cell cultures. In this research, an online monitoring system based on respiration activity was developed to monitor cell viability within acellular lung scaffolds. First, acellular lung scaffolds were recellularized with human umbilical cord vein endothelial cells, and then, cell viability was monitored during a 5-day period. The real-time monitoring system generated a cell growth profile representing invaluable information on cell viability and proliferative states during the culture period. The cell growth profile obtained by the monitoring system was consistent with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide analysis and glucose consumption measurement. This system provided a means for noninvasive, real-time, and repetitive investigation of cell viability. Also, we showed the applicability of this monitoring system by introducing shaking as an operating parameter in a long-term culture.

Neo-vascularization of the stroke cavity by implantation of human neural stem cells on VEGF-releasing PLGA microparticles

PubMed Central

Bible, Ellen; Qutachi, Omar; Chau, David Y.S.; Alexander, Morgan R.; Shakesheff, Kevin M.; Modo, Michel

2012-01-01

Replacing the tissue lost after a stroke potentially provides a new neural substrate to promote recovery. However, significant neurobiological and biotechnological challenges need to be overcome to make this possibility into a reality. Human neural stem cells (hNSCs) can differentiate into mature brain cells, but require a structural support that retains them within the cavity and affords the formation of a de novo tissue. Nevertheless, in our previous work, even after a week, this primitive tissue is void of a vasculature that could sustain its long-term viability. Therefore, tissue engineering strategies are required to develop a vasculature. Vascular endothelial growth factor (VEGF) is known to promote the proliferation and migration of endothelial cells during angio- and arteriogenesis. VEGF by itself here did not affect viability or differentiation of hNSCs, whereas growing cells on poly(D,L-lactic acid-co-glycolic acid) (PLGA) microparticles, with or without VEGF, doubled astrocytic and neuronal differentiation. Secretion of a burst and a sustained delivery of VEGF from the microparticles in vivo attracted endothelial cells from the host into this primate tissue and in parts established a neovasculature, whereas in other parts endothelial cells were merely interspersed with hNSCs. There was also evidence of a hypervascularization indicating that further work will be required to establish an adequate level of vascularization. It is therefore possible to develop a putative neovasculature within de novo tissue that is forming inside a tissue cavity caused by a stroke. PMID:22818980

Responses to High Seawater Temperatures in Zooxanthellate Octocorals

PubMed Central

Sammarco, Paul W.; Strychar, Kevin B.

2013-01-01

Increases in Sea Surface Temperatures (SSTs) as a result of global warming have caused reef-building scleractinian corals to bleach worldwide, a result of the loss of obligate endosymbiotic zooxanthellae. Since the 1980’s, bleaching severity and frequency has increased, in some cases causing mass mortality of corals. Earlier experiments have demonstrated that zooxanthellae in scleractinian corals from three families from the Great Barrier Reef, Australia (Faviidae, Poritidae, and Acroporidae) are more sensitive to heat stress than their hosts, exhibiting differential symptoms of programmed cell death – apoptosis and necrosis. Most zooxanthellar phylotypes are dying during expulsion upon release from the host. The host corals appear to be adapted or exapted to the heat increases. We attempt to determine whether this adaptation/exaptation occurs in octocorals by examining the heat-sensitivities of zooxanthellae and their host octocoral alcyonacean soft corals – Sarcophyton ehrenbergi (Alcyoniidae), Sinularia lochmodes (Alcyoniidae), and Xenia elongata (Xeniidae), species from two different families. The soft coral holobionts were subjected to experimental seawater temperatures of 28, 30, 32, 34, and 36°C for 48 hrs. Host and zooxanthellar cells were examined for viability, apoptosis, and necrosis (in hospite and expelled) using transmission electron microscopy (TEM), fluorescent microscopy (FM), and flow cytometry (FC). As experimental temperatures increased, zooxanthellae generally exhibited apoptotic and necrotic symptoms at lower temperatures than host cells and were expelled. Responses varied species-specifically. Soft coral hosts were adapted/exapted to higher seawater temperatures than their zooxanthellae. As with the scleractinians, the zooxanthellae appear to be the limiting factor for survival of the holobiont in the groups tested, in this region. These limits have now been shown to operate in six species within five families and two orders of the Cnidaria in the western Pacific. We hypothesize that this relationship may have taxonomic implications for other obligate zooxanthellate cnidarians subject to bleaching. PMID:23405104

Responses to high seawater temperatures in zooxanthellate octocorals.

PubMed

Sammarco, Paul W; Strychar, Kevin B

2013-01-01

Increases in Sea Surface Temperatures (SSTs) as a result of global warming have caused reef-building scleractinian corals to bleach worldwide, a result of the loss of obligate endosymbiotic zooxanthellae. Since the 1980's, bleaching severity and frequency has increased, in some cases causing mass mortality of corals. Earlier experiments have demonstrated that zooxanthellae in scleractinian corals from three families from the Great Barrier Reef, Australia (Faviidae, Poritidae, and Acroporidae) are more sensitive to heat stress than their hosts, exhibiting differential symptoms of programmed cell death - apoptosis and necrosis. Most zooxanthellar phylotypes are dying during expulsion upon release from the host. The host corals appear to be adapted or exapted to the heat increases. We attempt to determine whether this adaptation/exaptation occurs in octocorals by examining the heat-sensitivities of zooxanthellae and their host octocoral alcyonacean soft corals - Sarcophyton ehrenbergi (Alcyoniidae), Sinularia lochmodes (Alcyoniidae), and Xenia elongata (Xeniidae), species from two different families. The soft coral holobionts were subjected to experimental seawater temperatures of 28, 30, 32, 34, and 36°C for 48 hrs. Host and zooxanthellar cells were examined for viability, apoptosis, and necrosis (in hospite and expelled) using transmission electron microscopy (TEM), fluorescent microscopy (FM), and flow cytometry (FC). As experimental temperatures increased, zooxanthellae generally exhibited apoptotic and necrotic symptoms at lower temperatures than host cells and were expelled. Responses varied species-specifically. Soft coral hosts were adapted/exapted to higher seawater temperatures than their zooxanthellae. As with the scleractinians, the zooxanthellae appear to be the limiting factor for survival of the holobiont in the groups tested, in this region. These limits have now been shown to operate in six species within five families and two orders of the Cnidaria in the western Pacific. We hypothesize that this relationship may have taxonomic implications for other obligate zooxanthellate cnidarians subject to bleaching.

The effect of ultrasound-related stimuli on cell viability in microfluidic channels

PubMed Central

2013-01-01

Background In ultrasonic micro-devices, contrast agent micro-bubbles are known to initiate cavitation and streaming local to cells, potentially compromising cell viability. Here we investigate the effects of US alone by omitting contrast agent and monitoring cell viability under moderate-to-extreme ultrasound-related stimuli. Results Suspended H9c2 cardiac myoblasts were exposed to ultrasonic fields within a glass micro-capillary and their viability monitored under different US-related stimuli. An optimal injection flow rate of 2.6 mL/h was identified in which, high viability was maintained (~95%) and no mechanical stress towards cells was evident. This flow rate also allowed sufficient exposure of cells to US in order to induce bioeffects (~5 sec), whilst providing economical sample collection and processing times. Although the transducer temperature increased from ambient 23°C to 54°C at the maximum experimental voltage (29 Vpp), computational fluid dynamic simulations and controls (absence of US) revealed that the cell medium temperature did not exceed 34°C in the pressure nodal plane. Cells exposed to US amplitudes ranging from 0–29 Vpp, at a fixed frequency sweep period (tsw = 0.05 sec), revealed that viability was minimally affected up to ~15 Vpp. There was a ~17% reduction in viability at 21 Vpp, corresponding to the onset of Rayleigh-like streaming and a ~60% reduction at 29 Vpp, corresponding to increased streaming velocity or the potential onset of cavitation. At a fixed amplitude (29 Vpp) but with varying frequency sweep period (tsw = 0.02-0.50 sec), cell viability remained relatively constant at tsw ≥ 0.08 sec, whilst viability reduced at tsw < 0.08 sec and minimum viability recorded at tsw = 0.05 sec. Conclusion The absence of CA has enabled us to investigate the effect of US alone on cell viability. Moderate-to-extreme US-related stimuli of cells have allowed us to discriminate between stimuli that maintain high viability and stimuli that significantly reduce cell viability. Results from this study may be of potential interest to researchers in the field of US-induced intracellular drug delivery and ultrasonic manipulation of biological cells. PMID:23809777

The effect of ultrasound-related stimuli on cell viability in microfluidic channels.

PubMed

Ankrett, Dyan N; Carugo, Dario; Lei, Junjun; Glynne-Jones, Peter; Townsend, Paul A; Zhang, Xunli; Hill, Martyn

2013-06-28

In ultrasonic micro-devices, contrast agent micro-bubbles are known to initiate cavitation and streaming local to cells, potentially compromising cell viability. Here we investigate the effects of US alone by omitting contrast agent and monitoring cell viability under moderate-to-extreme ultrasound-related stimuli. Suspended H9c2 cardiac myoblasts were exposed to ultrasonic fields within a glass micro-capillary and their viability monitored under different US-related stimuli. An optimal injection flow rate of 2.6 mL/h was identified in which, high viability was maintained (~95%) and no mechanical stress towards cells was evident. This flow rate also allowed sufficient exposure of cells to US in order to induce bioeffects (~5 sec), whilst providing economical sample collection and processing times. Although the transducer temperature increased from ambient 23°C to 54°C at the maximum experimental voltage (29 Vpp), computational fluid dynamic simulations and controls (absence of US) revealed that the cell medium temperature did not exceed 34°C in the pressure nodal plane. Cells exposed to US amplitudes ranging from 0-29 Vpp, at a fixed frequency sweep period (tsw = 0.05 sec), revealed that viability was minimally affected up to ~15 Vpp. There was a ~17% reduction in viability at 21 Vpp, corresponding to the onset of Rayleigh-like streaming and a ~60% reduction at 29 Vpp, corresponding to increased streaming velocity or the potential onset of cavitation. At a fixed amplitude (29 Vpp) but with varying frequency sweep period (tsw = 0.02-0.50 sec), cell viability remained relatively constant at tsw ≥ 0.08 sec, whilst viability reduced at tsw < 0.08 sec and minimum viability recorded at tsw = 0.05 sec. The absence of CA has enabled us to investigate the effect of US alone on cell viability. Moderate-to-extreme US-related stimuli of cells have allowed us to discriminate between stimuli that maintain high viability and stimuli that significantly reduce cell viability. Results from this study may be of potential interest to researchers in the field of US-induced intracellular drug delivery and ultrasonic manipulation of biological cells.

The Role of Exosomal VP40 in Ebola Virus Disease.

PubMed

Pleet, Michelle L; DeMarino, Catherine; Lepene, Benjamin; Aman, M Javad; Kashanchi, Fatah

2017-04-01

Ebola virus (EBOV) can cause a devastating hemorrhagic disease, leading to death in a short period of time. After infection, the resulting EBOV disease results in high levels of circulating cytokines, endothelial dysfunction, coagulopathy, and bystander lymphocyte apoptosis in humans and nonhuman primates. The VP40 matrix protein of EBOV is essential for viral assembly and budding from the host cell. Recent data have shown that VP40 exists in the extracellular environment, including in exosomes, and exosomal VP40 can impact the viability of recipient immune cells, including myeloid and T cells, through the regulation of the RNAi and endosomal sorting complexes required for transport pathways. In this study, we discuss the latest findings of the impact of exosomal VP40 on immune cells in vitro and its potential implications for pathogenesis in vivo.

Anti-apoptotic genes Bcl-2 and Bcl-xL overexpression can block iridovirus serine/threonine kinase-induced Bax/mitochondria-mediated cell death in GF-1 cells.

PubMed

Reshi, Latif; Wang, Hua-Ven; Hui, Cho-Fat; Su, Yu-Chin; Hong, Jiann-Ruey

2017-02-01

Although serine/threonine (ST) kinase is known to induce host cell death in GF-1 cells, it remains unclear how ST kinase induces mitochondrial function loss. In the present study, we addressed the issue of mitochondrial function loss by determining whether the Bcl-2 family members Bcl-2 and Bcl-xL can prevent ST kinase-induced cell death activity via interacting with the pro-apoptotic gene Bax. Grouper fin cells (GF-1) carrying EGFP-Bal-xL and EGFP-Bcl-2 fused genes were selected, established in cell culture, and used to examine the involvement of Bcl-2 and Bcl-xL overexpression in protection of GF-1 cells from the effects of the giant sea perch iridovirus (GSIV) ST kinase gene. Using the TUNEL assay, we found that EGFP-Bcl-2 and EGFP-Bcl-xL reduced GSIV ST kinase-induced apoptosis to 20% all at 24 h and 48 h post-transfection (pt). Also, Bcl-2 and Bcl-xL substantially reduced the percentage of cells with GSIV ST kinase-induced loss of mitochondrial membrane potential (Δψps) at 24 and 48 hpt, respectively, and this reduction correlated with a 30% and 50% enhancement of host cell viability at 24 and 48 hpt as compared with vector control. Moreover, analysis of the effect of Bcl-2 and Bcl-xL interaction with Bax targeted to mitochondria during ST kinase expression at 48 hpt found that Bcl-2 and Bcl-xL also interacted with Bax to block cytochrome c release. Finally, Bcl-2 and Bcl-xL overexpression caused blockage of ST kinase function at 48 hpt, which was correlated with preventing caspase-9 and -3 cleavage and activation, thereby blocking downstream death signaling events. Taken together, our results suggest that the ST kinase-induced Bax/mitochondria-mediated cell death pathway can be blocked by the interaction of Bcl-2 and Bcl-xL with Bax to inhibit cytochrome c release during MMP loss. This rescue activity also correlated with inhibition of caspase-9 and -3 activation, thereby enhancing cell viability. Copyright © 2016 Elsevier Ltd. All rights reserved.

In Vitro Evaluation of Cell Compatibility of Dental Cements Used with Titanium Implant Components.

PubMed

Marvin, Jason C; Gallegos, Silvia I; Parsaei, Shaida; Rodrigues, Danieli C

2018-03-09

To evaluate the biocompatibility of five dental cement compositions after directly exposing human gingival fibroblast (HGF) and MC3T3-E1 preosteoblast cells to cement alone and cement applied on commercially pure titanium (cpTi) specimens. Nanostructurally integrated bioceramic (NIB), resin (R), resin-modified glass ionomer (RMGIC), zinc oxide eugenol (ZOE), and zinc phosphate (ZP) compositions were prepared according to the respective manufacturer's instructions. Samples were prepared in cylindrical Teflon molds or applied over the entire surface of polished cpTi discs. All samples were cured for 0.5, 1, 12, or 24 hours post-mixing. Direct contact testing was conducted according to ISO 10993 by seeding 6-well plates at 350,000 cells/well. Plates were incubated at 37°C in a humidified atmosphere with 5% CO 2 for 24 hours before individually plating samples and cpTi control discs. Plates were then incubated for an additional 24 hours. Microtetrazolium (MTT) cell viability assays were used to measure sample cytotoxicity. For samples that cured for 24 hours prior to direct contact exposure, only NIB and ZP cements when cemented on cpTi demonstrated cell viability percentages above the minimum biocompatibility requirement (≥70%) for both the investigative cell lines. R, RMGIC, and ZOE cements exhibited moderate to severe cytotoxic effects on both cell lines in direct contact and when cemented on cpTi specimens. For HGF cells, ZOE cemented-cpTi specimens exhibited significantly decreased cytotoxicity, whereas RMGIC cemented-cpTi specimens exhibited significantly increased cytotoxicity. Despite previous studies that showed enhanced cpTi corrosion activity for fluoride-containing compositions (NIB and ZP), there was no significant difference in cytotoxicity between cement alone and cemented-cpTi. In general, the MC3T3-E1 preosteoblast cells were more sensitive than HGF cells to cement composition. Ultimately, cement composition played a significant role in maintaining host cell compatibility. Results of this work help illustrate the impact of different cement formulations on host cell health and emphasize the need for understanding material properties when selecting certain formulations of dental cements, which can ultimately influence the survival of dental implant systems. © 2018 by the American College of Prosthodontists.

Iron and copper as virulence modulators in human fungal pathogens.

PubMed

Ding, Chen; Festa, Richard A; Sun, Tian-Shu; Wang, Zhan-You

2014-07-01

Fungal pathogens have evolved sophisticated machinery to precisely balance the fine line between acquiring essential metals and defending against metal toxicity. Iron and copper are essential metals for many processes in both fungal pathogens and their mammalian hosts, but reduce viability when present in excess. However, during infection, the host uses these two metals differently. Fe has a long-standing history of influencing virulence in pathogenic fungi, mostly in regards to Fe acquisition. Numerous studies demonstrate the requirement of the Fe acquisition pathway of Candida, Cryptococcus and Aspergillus for successful systemic infection. Fe is not free in the host, but is associated with Fe-binding proteins, leading fungi to develop mechanisms to interact with and to acquire Fe from these Fe-bound proteins. Cu is also essential for cell growth and development. Essential Cu-binding proteins include Fe transporters, superoxide dismutase (SOD) and cytochrome c oxidase. Although Cu acquisition plays critical roles in fungal survival in the host, recent work has revealed that Cu detoxification is extremely important. Here, we review fungal responses to altered metal conditions presented by the host, contrast the roles of Fe and Cu during infection, and outline the critical roles of fungal metal homeostasis machinery at the host-pathogen axis. © 2014 John Wiley & Sons Ltd.

Betulin derivatives impair Leishmania braziliensis viability and host-parasite interaction.

PubMed

Alcazar, Wilmer; López, Adrian Silva; Alakurtti, Sami; Tuononen, Maija-Liisa; Yli-Kauhaluoma, Jari; Ponte-Sucre, Alicia

2014-11-01

Leishmaniasis is a public health problem in tropical and subtropical areas of the world, including Venezuela. The incidence of treatment failure and the number of cases with Leishmania-HIV co-infection underscore the importance of developing alternative, economical and effective therapies against this disease. The work presented here analyzed whether terpenoids derived from betulin are active against New World Leishmania parasites. Initially we determined the concentration that inhibits the growth of these parasites by 50% or IC50, and subsequently evaluated the chemotactic effect of four compounds with leishmanicidal activity in the sub-micromolar and micromolar range. That is, we measured the migratory capacity of Leishmania (V.) braziliensis in the presence of increasing concentrations of compounds. Finally, we evaluated their cytotoxicity against the host cell and their effect on the infectivity of L. (V.) braziliensis. The results suggest that (1) compounds 14, 17, 18, 25 and 27 are active at concentrations lower than 10 μM; (2) compound 26 inhibits parasite growth with an IC50 lower than 1 μM; (3) compounds 18, 26 and 27 inhibit parasite migration at pico- to nanomolar concentrations, suggesting that they impair host-parasite interaction. None of the tested compounds was cytotoxic against J774.A1 macrophages thus indicating their potential as starting points to develop compounds that might affect parasite-host cell interaction, as well as being leishmanicidal. Copyright © 2014 Elsevier Ltd. All rights reserved.

Human Gastric Mucins Differently Regulate Helicobacter pylori Proliferation, Gene Expression and Interactions with Host Cells

PubMed Central

Skoog, Emma C.; Sjöling, Åsa; Navabi, Nazanin; Holgersson, Jan; Lundin, Samuel B.; Lindén, Sara K.

2012-01-01

Helicobacter pylori colonizes the mucus niche of the gastric mucosa and is a risk factor for gastritis, ulcers and cancer. The main components of the mucus layer are heavily glycosylated mucins, to which H. pylori can adhere. Mucin glycosylation differs between individuals and changes during disease. Here we have examined the H. pylori response to purified mucins from a range of tumor and normal human gastric tissue samples. Our results demonstrate that mucins from different individuals differ in how they modulate both proliferation and gene expression of H. pylori. The mucin effect on proliferation varied significantly between samples, and ranged from stimulatory to inhibitory, depending on the type of mucins and the ability of the mucins to bind to H. pylori. Tumor-derived mucins and mucins from the surface mucosa had potential to stimulate proliferation, while gland-derived mucins tended to inhibit proliferation and mucins from healthy uninfected individuals showed little effect. Artificial glycoconjugates containing H. pylori ligands also modulated H. pylori proliferation, albeit to a lesser degree than human mucins. Expression of genes important for the pathogenicity of H. pylori (babA, sabA, cagA, flaA and ureA) appeared co-regulated in response to mucins. The addition of mucins to co-cultures of H. pylori and gastric epithelial cells protected the viability of the cells and modulated the cytokine production in a manner that differed between individuals, was partially dependent of adhesion of H. pylori to the gastric cells, but also revealed that other mucin factors in addition to adhesion are important for H. pylori-induced host signaling. The combined data reveal host-specific effects on proliferation, gene expression and virulence of H. pylori due to the gastric mucin environment, demonstrating a dynamic interplay between the bacterium and its host. PMID:22563496

Development of a high yielding E. coli periplasmic expression system for the production of humanized Fab' fragments.

PubMed

Ellis, Mark; Patel, Pareshkumar; Edon, Marjory; Ramage, Walter; Dickinson, Robert; Humphreys, David P

2017-01-01

Humanized Fab' fragments may be produced in the periplasm of Escherichia coli but can be subject to degradation by host cell proteases. In order to increase Fab' yield and reduce proteolysis we developed periplasmic protease deficient strains of E. coli. These strains lacked the protease activity of Tsp, protease III and DegP. High cell density fermentations indicated Tsp deficient strains increased productivity two fold but this increase was accompanied by premature cell lysis soon after the induction of Fab' expression. To overcome the reduction in cell viability we introduced suppressor mutations into the spr gene. The mutations partially restored the wild type phenotype of the cells. Furthermore, we coexpressed a range of periplasmic chaperone proteins with the Fab', DsbC had the most significant impact, increasing humanized Fab' production during high cell density fermentation. When DsbC coexpression was combined with a Tsp deficient spr strain we observed an increase in yield and essentially restored "wild type" cell viability. We achieved a final periplasmic yield of over 2.4g/L (final cell density OD 600 105), 40 h post Fab' induction with minimal cell lysis.The data suggests that proteolysis, periplasm integrity, protein folding and disulphide bond formation are all potential limiting steps in the production of Fab' fragments in the periplasm of E. coli. In this body of work, we have addressed these limiting steps by utilizing stabilized protease deficient strains and chaperone coexpression. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 33:212-220, 2017. © 2016 American Institute of Chemical Engineers.

1-O-hexadecyloxypropyl cidofovir (CMX001) effectively inhibits polyomavirus BK replication in primary human renal tubular epithelial cells.

PubMed

Rinaldo, Christine Hanssen; Gosert, Rainer; Bernhoff, Eva; Finstad, Solrun; Hirsch, Hans H

2010-11-01

Antiviral drugs for treating polyomavirus BK (BKV) replication in polyomavirus-associated nephropathy or hemorrhagic cystitis are of considerable clinical interest. Unlike cidofovir, the lipid conjugate 1-O-hexadecyloxypropyl cidofovir (CMX001) is orally available and has not caused detectable nephrotoxicity in rodent models or human studies to date. Primary human renal proximal tubular epithelial cells were infected with BKV-Dunlop, and CMX001 was added 2 h postinfection (hpi). The intracellular and extracellular BKV DNA load was determined by quantitative PCR. Viral gene expression was examined by quantitative reverse transcription-PCR, Western blotting, and immunofluorescence microscopy. We also examined host cell viability, proliferation, metabolic activity, and DNA replication. The titration of CMX001 identified 0.31 μM as the 90% effective concentration (EC(90)) for reducing the extracellular BKV load at 72 hpi. BKV large T antigen mRNA and protein expression was unaffected at 24 hpi, but the intracellular BKV genome was reduced by 90% at 48 hpi. Late gene expression was reduced by 70 and 90% at 48 and 72 hpi, respectively. Comparisons of CMX001 and cidofovir EC(90)s from 24 to 96 hpi demonstrated that CMX001 had a more rapid and enduring effect on BKV DNA and infectious progeny at 96 hpi than cidofovir. CMX001 at 0.31 μM had little effect on overall cell metabolism but reduced bromodeoxyuridine incorporation and host cell proliferation by 20 to 30%, while BKV infection increased cell proliferation in both rapidly dividing and near-confluent cultures. We conclude that CMX001 inhibits BKV replication with a longer-lasting effect than cidofovir at 400× lower levels, with fewer side effects on relevant host cells in vitro.

Co-option of endocytic functions of cellular caveolae by pathogens

PubMed Central

Shin, J-S; Abraham, S N

2001-01-01

It is increasingly becoming clear that various immune cells are infected by the very pathogens that they are supposed to attack. Although many mechanisms for microbial entry exist, it appears that a common route of entry shared by certain bacteria, viruses and parasites involves cellular lipid-rich microdomains sometimes called caveolae. These cellular entities, which are characterized by their preferential accumulation of glycosylphosphatidylinositol (GPI)-anchored molecules, cholesterol and various glycolipids, and a distinct protein (caveolin), are present in many effector cells of the immune system including neutrophils, macrophages, mast cells and dendritic cells. These structures have an innate capacity to endocytoze various ligands and traffic them to different intracellular sites and sometimes, back to the extracellular cell surface. Because caveolae do not typically fuse with lysosomes, the ligands borne by caveolar vesicles are essentially intact, which is in marked contrast to ligands endocytozed via the classical endosome–lysosome pathway. A number of microbes or their exotoxins co-opt the unique features of caveolae to enter and traffic, without any apparent loss of viability and function, to different sites within immune and other host cells. In spite of their wide disparity in size and other structural attributes, we predict that a common feature among caveolae-utilizing pathogens and toxins is that their cognate receptor(s) are localized within plasmalemmal caveolae of the host cell. PMID:11168630

Detecting cell lysis using viscosity monitoring in E. coli fermentation to prevent product loss.

PubMed

Newton, Joseph M; Schofield, Desmond; Vlahopoulou, Joanna; Zhou, Yuhong

2016-07-08

Monitoring the physical or chemical properties of cell broths to infer cell status is often challenging due to the complex nature of the broth. Key factors indicative of cell status include cell density, cell viability, product leakage, and DNA release to the fermentation broth. The rapid and accurate prediction of cell status for hosts with intracellular protein products can minimise product loss due to leakage at the onset of cell lysis in fermentation. This article reports the rheological examination of an industrially relevant E. coli fermentation producing antibody fragments (Fab'). Viscosity monitoring showed an increase in viscosity during the exponential phase in relation to the cell density increase, a relatively flat profile in the stationary phase, followed by a rapid increase which correlated well with product loss, DNA release and loss of cell viability. This phenomenon was observed over several fermentations that a 25% increase in broth viscosity (using induction-point viscosity as a reference) indicated 10% product loss. Our results suggest that viscosity can accurately detect cell lysis and product leakage in postinduction cell cultures, and can identify cell lysis earlier than several other common fermentation monitoring techniques. This work demonstrates the utility of rapidly monitoring the physical properties of fermentation broths, and that viscosity monitoring has the potential to be a tool for process development to determine the optimal harvest time and minimise product loss. © 2016 The Authors. Biotechnology Progress published by Wiley Periodicals, Inc. on behalf of American Institute of Chemical Engineers, 32:1069-1076, 2016. © 2016 The Authors. Biotechnology Progress published by Wiley Periodicals, Inc. on behalf of American Institute of Chemical Engineers.

Integration host factor is important for biofilm formation by Salmonella enterica Enteritidis.

PubMed

Leite, Bruna; Werle, Catierine Hirsch; Carmo, Camila Pinheiro do; Nóbrega, Diego Borin; Milanez, Guilherme Paier; Culler, Hebert Fabricio; Sircili, Marcelo Palma; Alvarez-Martinez, Cristina E; Brocchi, Marcelo

2017-08-31

Salmonella enterica Enteritidis forms biofilms and survives in agricultural environments, infecting poultry and eggs. Bacteria in biofilms are difficult to eradicate compared to planktonic cells, causing serious problems in industry and public health. In this study, we evaluated the role of ihfA and ihfB in biofilm formation by S. enterica Enteritidis by employing different microbiology techniques. Our data indicate that ihf mutant strains are impaired in biofilm formation, showing a reduction in matrix formation and a decrease in viability and metabolic activity. Phenotypic analysis also showed that deletion of ihf causes a deficiency in curli fimbriae expression, cellulose production and pellicle formation. These results show that integration host factor has an important regulatory role in biofilm formation by S. enterica Enteritidis. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Comparisons of human amniotic mesenchymal stem cell viability in FDA-approved collagen-based scaffolds: Implications for engineered diaphragmatic replacement.

PubMed

Shieh, Hester F; Graham, Christopher D; Brazzo, Joseph A; Zurakowski, David; Fauza, Dario O

2017-06-01

We sought to examine amniotic fluid mesenchymal stem cell (afMSC) viability within two FDA-approved collagen-based scaffolds, as a prerequisite to clinical translation of afMSC-based engineered diaphragmatic repair. Human afMSCs were seeded in a human-derived collagen hydrogel and in a bovine-derived collagen sheet at 3 matching densities. Cell viability was analyzed at 1, 3, and 5days using an ATP-based 3D bioluminescence assay. Statistical comparisons were by ANOVA (P<0.05). There was a highly significant 3-way interaction between scaffold type, seeding density, and time in 3D culture as determinants of cell viability, clearly favoring the human hydrogel (P<0.001). In both scaffolds, cell viability was highest at the highest seeding density of 150,000 cells/mL. Time in 3D culture impacted cell viability at the optimal seeding density in the human hydrogel, with the highest levels on days 1 (P<0.001) and 5 (P=0.05) with no significant effect in the bovine sheet (P=0.39-0.96). Among clinically-approved cell delivery vehicles, mesenchymal stem cell viability is significantly enhanced in a collagen hydrogel when compared with a collagen sheet. Cell viability can be further optimized by seeding density and time in 3D culture. These data further support the regulatory viability of clinical trials of engineered diaphragmatic repair. N/A (animal and laboratory study). Copyright © 2017 Elsevier Inc. All rights reserved.

Lipopolysaccharide and Lipoteichoic Acid Virulence Deactivation by Stannous Fluoride.

PubMed

Haught, Chris; Xie, Sancai; Circello, Ben; Tansky, Cheryl S; Khambe, Deepa; Klukowska, Malgorzata; Huggins, Tom; White, Donald J

2016-09-01

Oral bacterial pathogens promote gingivitis and periodontal disease. Bacterial endotoxins, also known as lipopolysaccharides (LPSs) and lipoteichoic acids (LTAs), are known to enhance bacterial pathogenicity through binding with Toll-like receptors (TLRs), a group of pattern recognition receptors critical to the activation of innate immunity, that are expressed on host cells. Both LPS and LTA contain lipophilic domains and anionic charges that may be susceptible to reactivity with stannous fluoride, a commonly used ingredient clinically proven for the treatment and prevention of gingivitis. This study examined the effects of stannous fluoride on Toll-like receptor activation in response to bacterially derived LPS and LTA in select cell lines and secretion of inflammatory cytokines from human primary peripheral monocytes likewise exposed to LPS. TLR4 and TLR2 transfected HEK293 cells and THP1-Dual™ cells were exposed to bacterial LPS and LTA in the presence of increasing concentrations of stannous fluoride. Gene expression was assessed by measurement of secreted embryonic alkaline phosphatase (SEAP) reporter gene for HEK293 cells and SEAP and luciferase for THP-1 cells. Cell viability was confirmed using PrestoBlue. Human primary monocytes were treated with LPS with various concentrations of supplemented stannous fluoride, and cytokine expression was directly measured. Stannous fluoride inhibited gene expression response of TLR4 and TLR2 in HEK293 cells and THP1-Dual™ cells in a dose response fashion, producing complete inhibition at micromolar concentrations. The addition of stannous fluoride suppressed production of TNF-a, IFN-g, IL12p70, IL10, IL-1b, IL2, and IL-6, and also increased secretion of Il-8 in dose response fashion. Viability assays confirmed no effects of LPS or stannous fluoride on viability of HEK293, THP-1, and primary human monocytes. These results support the potential for stannous fluoride to provide clinical gingivitis benefits by directly decreasing the pathogenicity of plaque biofilms by blocking reactivity of LPS and LTA ligands with tissue receptors associated with inflammation. These learnings may influence recommendations for patients at risk for plaque-related diseases.

Anthropogenic Impacts on Mortality and Population Viability of the Monarch Butterfly.

PubMed

Malcolm, Stephen B

2018-01-07

Monarch butterflies (Danaus plexippus) are familiar herbivores of milkweeds of the genus Asclepias, and most monarchs migrate each year to locate these host plants across North American ecosystems now dominated by agriculture. Eastern migrants overwinter in high-elevation forests in Mexico, and western monarchs overwinter in trees on the coast of California. Both populations face three primary threats to their viability: (a) loss of milkweed resources for larvae due to genetically modified crops, pesticides, and fertilizers; (b) loss of nectar resources from flowering plants; and (c) degraded overwintering forest habitats due to commercially motivated deforestation and other economic activities. Secondary threats to population viability include (d) climate change effects on milkweed host plants and the dynamics of breeding, overwintering, and migration; (e) the influence of invasive plants and natural enemies; (f) habitat fragmentation and coalescence that promote homogeneous, species-depleted landscapes; and (g) deliberate culture and release of monarchs and invasive milkweeds.

Spread of butternut canker in North America, host range, evidence of resistance within butternut populations and conservation genetics

Treesearch

M. E. Ostry; K. Woeste

2004-01-01

Butternut canker is killing trees throughout the range of butternut in North America and is threatening the viability of many populations in several areas. Although butternut is the primary host, other Juglans species and some hardwood species also are potential hosts. Evidence is building that genetic resistance within butternut populations may be...

Enhanced viability of corneal epithelial cells for efficient transport/storage using a structurally modified calcium alginate hydrogel.

PubMed

Wright, Bernice; Cave, Richard A; Cook, Joseph P; Khutoryanskiy, Vitaliy V; Mi, Shengli; Chen, Bo; Leyland, Martin; Connon, Che J

2012-05-01

Therapeutic limbal epithelial stem cells could be managed more efficiently if clinically validated batches were transported for 'on-demand' use. In this study, corneal epithelial cell viability in calcium alginate hydrogels was examined under cell culture, ambient and chilled conditions for up to 7 days. Cell viability improved as gel internal pore size increased, and was further enhanced with modification of the gel from a mass to a thin disc. Ambient storage conditions were optimal for supporting cell viability in gel discs. Cell viability in gel discs was significantly enhanced with increases in pore size mediated by hydroxyethyl cellulose. Our novel methodology of controlling alginate gel shape and pore size together provides a more practical and economical alternative to established corneal tissue/cell storage methods.

How type 1 fimbriae help Escherichia coli to evade extracellular antibiotics.

PubMed

Avalos Vizcarra, Ima; Hosseini, Vahid; Kollmannsberger, Philip; Meier, Stefanie; Weber, Stefan S; Arnoldini, Markus; Ackermann, Martin; Vogel, Viola

2016-01-05

To survive antibiotics, bacteria use two different strategies: counteracting antibiotic effects by expression of resistance genes or evading their effects e.g. by persisting inside host cells. Since bacterial adhesins provide access to the shielded, intracellular niche and the adhesin type 1 fimbriae increases bacterial survival chances inside macrophages, we asked if fimbriae also influenced survival by antibiotic evasion. Combined gentamicin survival assays, flow cytometry, single cell microscopy and kinetic modeling of dose response curves showed that type 1 fimbriae increased the adhesion and internalization by macrophages. This was caused by strongly decreased off-rates and affected the number of intracellular bacteria but not the macrophage viability and morphology. Fimbriae thus promote antibiotic evasion which is particularly relevant in the context of chronic infections.

Efficient Intracellular Delivery of Molecules with High Cell Viability Using Nanosecond-Pulsed Laser-Activated Carbon Nanoparticles

PubMed Central

2015-01-01

Conventional physical and chemical methods that efficiently deliver molecules into cells are often associated with low cell viability. In this study, we evaluated the cellular effects of carbon nanoparticles believed to emit photoacoustic waves due to nanosecond-pulse laser activation to test the hypothesis that this method could achieve efficient intracellular delivery while maintaining high cell viability. Suspensions of DU145 human prostate carcinoma cells, carbon black (CB) nanoparticles, and calcein were exposed to 5–9 ns long laser pulses of near-infrared (1064 nm wavelength) light and then analyzed by flow cytometry for intracellular uptake of calcein and cell viability by propidium iodide staining. We found that intracellular uptake increased and in some cases saturated at high levels with only small losses in cell viability as a result of increasing laser fluence, laser exposure time, and as a unifying parameter, the total laser energy. Changing interpulse spacing between 0.1 and 10 s intervals showed no significant change in bioeffects, suggesting that the effects of each pulse were independent when spaced by at least 0.1 s intervals. Pretreatment of CB nanoparticles to intense laser exposure followed by mixing with cells also had no significant effect on uptake or viability. Similar uptake and viability were seen when CB nanoparticles were substituted with India ink, when DU145 cells were substituted with H9c2 rat cardiomyoblast cells, and when calcein was substituted with FITC-dextran. The best laser exposure conditions tested led to 88% of cells with intracellular uptake and close to 100% viability, indicating that nanosecond-pulse laser-activated carbon nanoparticles can achieve efficient intracellular delivery while maintaining high cell viability. PMID:24547946

Combination of hyperthermia and photodynamic therapy on mesenchymal stem cell line treated with chloroaluminum phthalocyanine magnetic-nanoemulsion

NASA Astrophysics Data System (ADS)

de Paula, Leonardo B.; Primo, Fernando L.; Pinto, Marcelo R.; Morais, Paulo C.; Tedesco, Antonio C.

2015-04-01

The present study reports on the preparation and the cell viability assay of two nanoemulsions loaded with magnetic nanoparticle and chloroaluminum phthalocyanine. The preparations contain equal amount of chloroaluminum phthalocyanine (0.05 mg/mL) but different contents of magnetic nanoparticle (0.15×1013 or 1.50×1013 particle/mL). The human bone marrow mesenchymal stem cell line was used as the model to assess the cell viability and this type of cell can be used as a model to mimic cancer stem cells. The cell viability assays were performed in isolated as well as under combined magnetic hyperthermia and photodynamic therapy treatments. We found from the cell viability assay that under the hyperthermia treatment (1 MHz and 40 Oe magnetic field amplitude) the cell viability reduction was about 10%, regardless the magnetic nanoparticle content within the magnetic nanoparticle/chloroaluminum phthalocyanine formulation. However, cell viability reduction of about 50% and 60% were found while applying the photodynamic therapy treatment using the magnetic nanoparticle/chloroaluminum phthalocyanine formulation containing 0.15×1013 or 1.50×1013 magnetic particle/mL, respectively. Finally, an average reduction in cell viability of about 66% was found while combining the hyperthermia and photodynamic therapy treatments.

Phenotypic and Genetic Evaluation of the Influence of Pseudomonas aeruginosa Culture Fractions on the Human Mesenchymal Stem Cells Viability, Apoptotic Pathways and Cytokine Profile.

PubMed

Holban, Alina Maria; Bleotu, Coralia; Chifiriuc, Mariana Carmen; Lazar, Veronica

2017-01-01

The objective of this study was to investigate the effects of P. aeruginosa PAO1 cellular and soluble culture fractions on human mesenchymal stem cells (MSCs) death signaling pathways and cytokine profile. The bone marrow isolated MSCs, incubated for different periods of time with one of the three P. aeruginosa PAO1 culture fractions, i.e. low density whole cultures, heat inactivated bacterial cultures sediments and sterile supernatants, were submitted to the following assays: i) fluorescence microscopy evaluation of cellular morphology and viability; ii) bax, caspase 9, relA and bcl-2 genes expression analysis by qRT-PCR; and iii) quantification of the level of IL-1β, IL-6, IL-8 and IL-10 cytokines released in the MSCs supernatants determined by ELISA. Results were statistically analyzed using the GraphPad In Stat software. The PAO1 whole cultures exhibited the most relevant influences, impacting on MSCs morphology and viability, interfering with apoptotic pathways and significantly stimulating the production of IL-1β and IL-10, while decreasing the production of IL-6 and IL-8. The culture supernatants increased the production of IL-1β and reduced the secretion of all other tested cytokines, while heat-inactivated bacterial cells significantly stimulated both IL-1β and IL-10 production. These data could suggest that in vivo, the fate of P. aeruginosa infection depends on the proportion between different bacterial culture fractions (i.e. the number of viable bacterial cells, the number of dead cells and the amount of bacterial soluble products accumulated locally) that could be influenced by the initial infective dose, by the host defense mechanisms, and also by the administered antimicrobial treatment that may thus interfere with the evolution and magnitude of the induced lesions. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Imatinib mesylate (Glivec) inhibits Schwann cell viability and reduces the size of human plexiform neurofibroma in a xenograft model.

PubMed

Demestre, Maria; Herzberg, Jan; Holtkamp, Nikola; Hagel, Christian; Reuss, David; Friedrich, Reinhard E; Kluwe, Lan; Von Deimling, Andreas; Mautner, Victor-F; Kurtz, Andreas

2010-05-01

Plexiform neurofibromas (PNF), one of the major features of neurofibromatosis type 1 (NF1), are characterized by complex cellular composition and mostly slow but variable growth patterns. In this study, we examined the effect of imatinib mesylate, a receptor tyrosine kinase inhibitor, on PNF-derived Schwann cells and PNF tumour growth in vitro and in vivo. In vitro, PNF-derived primary Schwann cells express platelet-derived growth factors receptors (PDGFR) alpha and beta, both targets of imatinib, and cell viability was reduced by imatinib mesylate, with 50% inhibition concentration (IC(50)) of 10 microM. For in vivo studies, PNF tumour fragments xenografted onto the sciatic nerve of athymic nude mice were first characterized. The tumours persisted for at least 63 days and maintained typical characteristics of PNFs such as complex cellular composition, low proliferation rate and angiogenesis. A transient enlargement of the graft size was due to inflammation by host cells. Treatment with imatinib mesylate at a daily dose of 75 mg/kg for 4 weeks reduced the graft size by an average of 80% (n = 8), significantly different from the original sizes within the group and from sizes of the grafts in 11 untreated mice in the control group (P < 0.001). We demonstrated that grafting human PNF tumour fragments into nude mice provides an adequate in vivo model for drug testing. Our results provide in vivo and in vitro evidence for efficacy of imatinib mesylate for PNF.

Mps1 kinase regulates tumor cell viability via its novel role in mitochondria

PubMed Central

Zhang, X; Ling, Y; Guo, Y; Bai, Y; Shi, X; Gong, F; Tan, P; Zhang, Y; Wei, C; He, X; Ramirez, A; Liu, X; Cao, C; Zhong, H; Xu, Q; Ma, R Z

2016-01-01

Targeting mitotic kinase monopolar spindle 1 (Mps1) for tumor therapy has been investigated for many years. Although it was suggested that Mps1 regulates cell viability through its role in spindle assembly checkpoint (SAC), the underlying mechanism remains less defined. In an endeavor to reveal the role of high levels of mitotic kinase Mps1 in the development of colon cancer, we unexpectedly found the amount of Mps1 required for cell survival far exceeds that of maintaining SAC in aneuploid cell lines. This suggests that other functions of Mps1 besides SAC are also employed to maintain cell viability. Mps1 regulates cell viability independent of its role in cytokinesis as the genetic depletion of Mps1 spanning from metaphase to cytokinesis affects neither cytokinesis nor cell viability. Furthermore, we developed a single-cycle inhibition strategy that allows disruption of Mps1 function only in mitosis. Using this strategy, we found the functions of Mps1 in mitosis are vital for cell viability as short-term treatment of mitotic colon cancer cell lines with Mps1 inhibitors is sufficient to cause cell death. Interestingly, Mps1 inhibitors synergize with microtubule depolymerizing drug in promoting polyploidization but not in tumor cell growth inhibition. Finally, we found that Mps1 can be recruited to mitochondria by binding to voltage-dependent anion channel 1 (VDAC1) via its C-terminal fragment. This interaction is essential for cell viability as Mps1 mutant defective for interaction fails to main cell viability, causing the release of cytochrome c. Meanwhile, deprivation of VDAC1 can make tumor cells refractory to loss of Mps1-induced cell death. Collectively, we conclude that inhibition of the novel mitochondrial function Mps1 is sufficient to kill tumor cells. PMID:27383047

Mps1 kinase regulates tumor cell viability via its novel role in mitochondria.

PubMed

Zhang, X; Ling, Y; Guo, Y; Bai, Y; Shi, X; Gong, F; Tan, P; Zhang, Y; Wei, C; He, X; Ramirez, A; Liu, X; Cao, C; Zhong, H; Xu, Q; Ma, R Z

2016-07-07

Targeting mitotic kinase monopolar spindle 1 (Mps1) for tumor therapy has been investigated for many years. Although it was suggested that Mps1 regulates cell viability through its role in spindle assembly checkpoint (SAC), the underlying mechanism remains less defined. In an endeavor to reveal the role of high levels of mitotic kinase Mps1 in the development of colon cancer, we unexpectedly found the amount of Mps1 required for cell survival far exceeds that of maintaining SAC in aneuploid cell lines. This suggests that other functions of Mps1 besides SAC are also employed to maintain cell viability. Mps1 regulates cell viability independent of its role in cytokinesis as the genetic depletion of Mps1 spanning from metaphase to cytokinesis affects neither cytokinesis nor cell viability. Furthermore, we developed a single-cycle inhibition strategy that allows disruption of Mps1 function only in mitosis. Using this strategy, we found the functions of Mps1 in mitosis are vital for cell viability as short-term treatment of mitotic colon cancer cell lines with Mps1 inhibitors is sufficient to cause cell death. Interestingly, Mps1 inhibitors synergize with microtubule depolymerizing drug in promoting polyploidization but not in tumor cell growth inhibition. Finally, we found that Mps1 can be recruited to mitochondria by binding to voltage-dependent anion channel 1 (VDAC1) via its C-terminal fragment. This interaction is essential for cell viability as Mps1 mutant defective for interaction fails to main cell viability, causing the release of cytochrome c. Meanwhile, deprivation of VDAC1 can make tumor cells refractory to loss of Mps1-induced cell death. Collectively, we conclude that inhibition of the novel mitochondrial function Mps1 is sufficient to kill tumor cells.

The viability of lytic bacteriophage ΦD5 in potato-associated environments and its effect on Dickeya solani in potato (Solanum tuberosum L.) plants

PubMed Central

Smolarska, Anna; Ozymko, Zofia

2017-01-01

Dickeya solani is one of the most important pectinolytic phytopathogens responsible for high losses in potato, especially in seed potato production in Europe. Lytic bacteriophages can affect the structure of the host population and may influence spread, survival and virulence of the pathogen and in consequence, infection of the plant. In this study, we aimed to acquire information on the viability of the broad host lytic bacteriophage ΦD5 on potato, as well as to apprehend the specific effect of this bacteriophage on its host D. solani type-strain in different settings, as a preliminary step to target co-adaptation of phages and host bacteria in plant environment. Viability of the ΦD5 phage in tuber extract, on tuber surface, in potting compost, in rainwater and on the leaf surface, as well as the effect of copper sulfate, were examined under laboratory conditions. Also, the interaction of ΦD5 with the target host D. solani in vitro and in compost-grown potato plants was evaluated. ΦD5 remained infectious in potato tuber extract and rain water for up to 72 h but was inactivated in solutions containing 50 mM of copper. The phage population was stable for up to 28 days on potato tuber surface and in potting compost. In both, tissue culture and compost-grown potato plants, ΦD5 reduced infection by D. solani by more than 50%. The implications of these findings are discussed. PMID:28800363

The viability of lytic bacteriophage ΦD5 in potato-associated environments and its effect on Dickeya solani in potato (Solanum tuberosum L.) plants.

PubMed

Czajkowski, Robert; Smolarska, Anna; Ozymko, Zofia

2017-01-01

Dickeya solani is one of the most important pectinolytic phytopathogens responsible for high losses in potato, especially in seed potato production in Europe. Lytic bacteriophages can affect the structure of the host population and may influence spread, survival and virulence of the pathogen and in consequence, infection of the plant. In this study, we aimed to acquire information on the viability of the broad host lytic bacteriophage ΦD5 on potato, as well as to apprehend the specific effect of this bacteriophage on its host D. solani type-strain in different settings, as a preliminary step to target co-adaptation of phages and host bacteria in plant environment. Viability of the ΦD5 phage in tuber extract, on tuber surface, in potting compost, in rainwater and on the leaf surface, as well as the effect of copper sulfate, were examined under laboratory conditions. Also, the interaction of ΦD5 with the target host D. solani in vitro and in compost-grown potato plants was evaluated. ΦD5 remained infectious in potato tuber extract and rain water for up to 72 h but was inactivated in solutions containing 50 mM of copper. The phage population was stable for up to 28 days on potato tuber surface and in potting compost. In both, tissue culture and compost-grown potato plants, ΦD5 reduced infection by D. solani by more than 50%. The implications of these findings are discussed.

The potential role of polyphenols in the modulation of skin cell viability by Aspalathus linearis and Cyclopia spp. herbal tea extracts in vitro.

PubMed

Magcwebeba, Tandeka Unathi; Riedel, Sylvia; Swanevelder, Sonja; Swart, Pieter; De Beer, Dalene; Joubert, Elizabeth; Andreas Gelderblom, Wentzel Christoffel

2016-11-01

The relationship between polyphenol constituents, antioxidant properties of aqueous and methanol extracts of green tea (Camellia sinensis), the herbal teas, rooibos (Aspalathus linearis) and honeybush (Cyclopia spp.), against skin cell viability was investigated in vitro. The effect of extracts, characterised in terms of polyphenol content and antioxidant properties, on cell viability of premalignant, normal and malignant skin cells was determined. Phenolic composition, particularly high levels of potent antioxidants, of rooibos and green tea methanol extracts was associated with a strong reduction in cell viability specifically targeting premalignant cells. In contrast, the aqueous extracts of Cyclopia spp. were more effective in reducing cell viability. This correlated with a relatively high flavanol/proanthocyanidin content and ABTS radical cation scavenging capacity. The major green tea flavanol (epigallocatechin gallate) and rooibos dihydrochalcone (aspalathin) exhibited differential effects against cell viability, while the major honeybush xanthone (mangiferin) and flavanone (hesperidin) lacked any effect presumably due to a cytoprotective effect. The underlying mechanisms against skin cell viability are likely to involve mitochondrial dysfunction resulting from polyphenol-iron interactions. The polyphenol constituents and antioxidant parameters of herbal tea extracts are useful tools to predict their activity against skin cell survival in vitro and potential chemopreventive effects in vivo. © 2016 Royal Pharmaceutical Society.

Inkjet printing Schwann cells and neuronal analogue NG108-15 cells.

PubMed

Tse, Christopher; Whiteley, Robert; Yu, Tong; Stringer, Jonathan; MacNeil, Sheila; Haycock, John W; Smith, Patrick J

2016-03-01

Porcine Schwann cells and neuronal analogue NG108-15 cells were printed using a piezoelectric-inkjet-printer with a nozzle diameter of 60 μm, within the range of 70-230 V, with analysis of viability and quality after printing. Neuronal and glial cell viabilities of >86% and >90% were detected immediately after printing and no correlation between voltage applied and cell viability could be seen. Printed neuronal cells were shown to produce neurites earlier compared to controls, and over several days, produced longer neurites which become most evident by day 7. The number of neurites becomes similar by day 7 also, and cells proliferate with a similar viability to that of non-printed cells (controls). This method of inkjet printing cells provides a technical platform for investigating neuron-glial cell interactions with no significant difference to cell viability than standard cell seeding. Such techniques can be utilized for lab-on-a-chip technologies and to create printed neural networks for neuroscience applications.

Folic-Acid-Targeted Self-Assembling Supramolecular Carrier for Gene Delivery.

PubMed

Liao, Rongqiang; Yi, Shouhui; Liu, Manshuo; Jin, Wenling; Yang, Bo

2015-07-27

A targeting gene carrier for cancer-specific delivery was successfully developed through a "multilayer bricks-mortar" strategy. The gene carrier was composed of adamantane-functionalized folic acid (FA-AD), an adamantane-functionalized poly(ethylene glycol) derivative (PEG-AD), and β-cyclodextrin-grafted low-molecular-weight branched polyethylenimine (PEI-CD). Carriers produced by two different self-assembly schemes, involving either precomplexation of the PEI-CD with the FA-AD and PEG-AD before pDNA condensation (Method A) or pDNA condensation with the PEI-CD prior to addition of the FA-AD and PEG-AD to engage host-guest complexation (Method B) were investigated for their ability to compact pDNA into nanoparticles. Cell viability studies show that the material produced by the Method A assembly scheme has lower cytotoxicity than branched PEI 25 kDa (PEI-25KD) and that the transfection efficiency is maintained. These findings suggest that the gene carrier, based on multivalent host-guest interactions, could be an effective, targeted, and low-toxicity carrier for delivering nucleic acid to target cells. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Long term cryopreservation in 5% DMSO maintains unchanged CD34(+) cells viability and allows satisfactory hematological engraftment after peripheral blood stem cell transplantation.

PubMed

Abbruzzese, L; Agostini, F; Durante, C; Toffola, R T; Rupolo, M; Rossi, F M; Lleshi, A; Zanolin, S; Michieli, M; Mazzucato, M

2013-07-01

Peripheral blood stem cell cryopreservation is associated with cell damage and decreased viability. We evaluated the impact of up to 10 years of cryopreservation (5% DMSO) on viability of CD34(+) cells utilizing graft samples of consecutive patients (2002-2012) with different malignancies who underwent stem cell collection and transplantation. Viability of CD34(+) cells from oncohaematological patients measured after 5 weeks (97·2 ± 0·6%) or after 9-10 years of cryopreservation (95·9 ± 0·5%) was unaffected. Haemoglobin, granulocyte and platelet recovery after transplantation of long-term cryopreserved grafts occurred within 8-13 days. CD34(+) stem cells can be safely stored up to 9-10 years, without affecting cell viability and clinical effectiveness. © 2013 International Society of Blood Transfusion.

An approach for cell viability online detection based on the characteristics of lensfree cell diffraction fingerprint.

PubMed

Li, Guoxiao; Zhang, Rongbiao; Yang, Ning; Yin, Changsheng; Wei, Mingji; Zhang, Yecheng; Sun, Jian

2018-06-01

To overcome the drawbacks such as low automation and high cost, an approach for cell viability online detection is proposed, based on the extracted lensfree cell diffraction fingerprint characteristics. The cell fingerprints are acquired by a constructed large field-of-view (FOV) diffraction imaging platform without any lenses. The approach realizes distinguishing live and dead cells online and calculating cell viability index based on the number of live cells. With theoretical analysis and simulation, diffraction fingerprints of cells with different morphology are simulated and two characteristics are discovered to be able to reflect cell viability status effectively. Two parameters, fringe intensity contrast (FIC) and fringe dispersion (FD), are defined to quantify these two characteristics. They are verified to be reliable to identify live cells. In a cytotoxicity assay of different methyl mercury concentration on BRL cells, the proposed approach is used to detect cell viability. MTT method is also employed and the results of correlational analysis and Bland-Altman analysis prove the validity of the proposed approach. By comparison, it can be revealed that the proposed approach has some advantages over other present techniques. Therefore it may be widely used as a cell viability measurement method in drug screening, nutritional investigation and cell toxicology studies. Copyright © 2018 Elsevier B.V. All rights reserved.

Fibrin facilitates both innate and T cell-mediated defense against Yersinia pestis.1

PubMed Central

Luo, Deyan; Lin, Shiuan; Parent, Michelle A.; Kanevsky, Isis Mullarky; Szaba, Frank M.; Kummer, Lawrence W.; Duso, Debra K.; Tighe, Michael; Hill, Jim; Gruber, Andras; Mackman, Nigel; Gailani, David; Smiley, Stephen T.

2013-01-01

The gram-negative bacterium Yersinia pestis causes plague, a rapidly progressing and often fatal disease. The formation of fibrin at sites of Y. pestis infection supports innate host defense against plague, perhaps by providing a non-diffusible spatial cue that promotes the accumulation of inflammatory cells expressing fibrin-binding integrins. This report demonstrates that fibrin is an essential component of T cell-mediated defense against plague but can be dispensable for antibody-mediated defense. Genetic or pharmacologic depletion of fibrin abrogated innate and T cell-mediated defense in mice challenged intranasally with Y. pestis. The fibrin-deficient mice displayed reduced survival, increased bacterial burden, and exacerbated hemorrhagic pathology. They also showed fewer neutrophils within infected lung tissue and reduced neutrophil viability at sites of liver infection. Depletion of neutrophils from wild type mice weakened T cell-mediated defense against plague. The data suggest that T cells combat plague in conjunction with neutrophils, which require help from fibrin in order to withstand Y. pestis encounters and effectively clear bacteria. PMID:23487423

Antitumor activity of four macrocyclic ellagitannins from Cuphea hyssopifolia.

PubMed

Wang, C C; Chen, L G; Yang, L L

1999-06-01

We evaluated the antitumor activities of four macrocyclic hydrolyzable tannin dimers, cuphiin D1, cuphiin D2, oenothein B and woodfordin C isolated from Cuphea hyssopifolia (Lythraceae). All significantly inhibited the growth of the human carcinoma cell lines KB, HeLa, DU-145, Hep 3B, and the leukemia cell line HL-60, and showed less cytotoxicity than adriamycin against a normal cell line (WISH). All four compounds inhibited the viability of S-180 tumor cells in an in vitro assay and an in vivo S-180 tumor-bearing ICR mice model. Oenothein B demonstrated the greatest cytotoxicity (IC50 = 11.4 microg/ml) against S-180 tumor cells in culture, while cuphiin D1 resulted in the greatest increase in survival on S-180 tumor-bearing mice (%ILS = 84.1%). Our findings suggest that the antitumor effects of these compounds are not only related to their cytotoxicity on carcinoma cell lines, but also depended on a host-mediated mechanism; they may therefore have potential for antitumor applications.

Cell viability monitoring using Fano resonance in gold nanoslit array

NASA Astrophysics Data System (ADS)

Wu, Shu-Han; Hsieh, Shu-Yi; Lee, Kuang-Li; Weng, Ruei-Hung; Chiou, Arthur; Wei, Pei-Kuen

2013-09-01

Cell viability is a crucial issue in biological research. We present label-free monitoring of adhesion cells viability by gold nanoslits-based Fano resonance biosensors. Plastic multiple wells with gold nanoslits substrate were made using a thermal nanoimprint method. Adhesion cells in the wells were treated with doxorubicin for inducing cell death and compared with conventional colorimetric assay. The nanoslits method shows better respones of viability tests under low concentration and short interaction time due to its high surface sensitivies. The vinculin labelling indicates that the measured signals are in good agreement with the adhesion abilities of cells.

The enemy within: Targeting host–parasite interaction for antileishmanial drug discovery

PubMed Central

Späth, Gerald F.; Rachidi, Najma; Prina, Eric

2017-01-01

The state of antileishmanial chemotherapy is strongly compromised by the emergence of drug-resistant Leishmania. The evolution of drug-resistant phenotypes has been linked to the parasites’ intrinsic genome instability, with frequent gene and chromosome amplifications causing fitness gains that are directly selected by environmental factors, including the presence of antileishmanial drugs. Thus, even though the unique eukaryotic biology of Leishmania and its dependence on parasite-specific virulence factors provide valid opportunities for chemotherapeutical intervention, all strategies that target the parasite in a direct fashion are likely prone to select for resistance. Here, we review the current state of antileishmanial chemotherapy and discuss the limitations of ongoing drug discovery efforts. We finally propose new strategies that target Leishmania viability indirectly via mechanisms of host–parasite interaction, including parasite-released ectokinases and host epigenetic regulation, which modulate host cell signaling and transcriptional regulation, respectively, to establish permissive conditions for intracellular Leishmania survival. PMID:28594938

Engineering the heart: Evaluation of conductive nanomaterials for improving implant integration and cardiac function

PubMed Central

Zhou, Jin; Chen, Jun; Sun, Hongyu; Qiu, Xiaozhong; Mou, Yongchao; Liu, Zhiqiang; Zhao, Yuwei; Li, Xia; Han, Yao; Duan, Cuimi; Tang, Rongyu; Wang, Chunlan; Zhong, Wen; Liu, Jie; Luo, Ying; (Mengqiu) Xing, Malcolm; Wang, Changyong

2014-01-01

Recently, carbon nanotubes together with other types of conductive materials have been used to enhance the viability and function of cardiomyocytes in vitro. Here we demonstrated a paradigm to construct ECTs for cardiac repair using conductive nanomaterials. Single walled carbon nanotubes (SWNTs) were incorporated into gelatin hydrogel scaffolds to construct three-dimensional ECTs. We found that SWNTs could provide cellular microenvironment in vitro favorable for cardiac contraction and the expression of electrochemical associated proteins. Upon implantation into the infarct hearts in rats, ECTs structurally integrated with the host myocardium, with different types of cells observed to mutually invade into implants and host tissues. The functional measurements showed that SWNTs were essential to improve the performance of ECTs in inhibiting pathological deterioration of myocardium. This work suggested that conductive nanomaterials hold therapeutic potential in engineering cardiac tissues to repair myocardial infarction. PMID:24429673

Apoptosis-inducing and apoptosis-preventing functions of poliovirus.

PubMed Central

Tolskaya, E A; Romanova, L I; Kolesnikova, M S; Ivannikova, T A; Smirnova, E A; Raikhlin, N T; Agol, V I

1995-01-01

Data showing that an apoptotic reaction (the exit into the cytoplasm and nucleolytic internucleosomal degradation of chromosomal DNA, compaction and fragmentation of chromatin, cellular shrinkage, and cytoplasmic blebbing) developed in a subline of HeLa-S3 cells upon nonpermissive poliovirus infection with either a guanidine-sensitive poliovirus in the presence of guanidine, a guanidine-dependent mutant in the absence of guanidine, or certain temperature-sensitive mutants at a restrictive temperature are presented. Essentially, no apoptotic reaction occurred upon permissive infection of these cells. Both permissive and nonpermissive infections resulted in the inhibition of host protein synthesis. Actinomycin D or cycloheximide also elicited a rapid apoptotic reaction in uninfected cells. However, preinfection or coinfection with poliovirus prevented the apoptotic response to the addition of actinomycin D, and preinfection blocked cycloheximide-induced apoptosis as well. These data fit a model in which the cells used are prepared to develop apoptosis, with their viability due to the presence of certain short-lived mRNA and protein species. Poliovirus infection turns on two oppositely directed sets of reactions. On the one hand, the balance is driven toward apoptosis, probably via the shutoff of host macromolecular synthesis. On the other hand, viral protein exhibits antiapoptotic activity, thereby preventing premature cell death. To our knowledge, this is the first description of an antiapoptotic function for an RNA virus. PMID:7529330

Controlling the Biomimetic Implant Interface: Modulating Antimicrobial Activity by Spacer Design

NASA Astrophysics Data System (ADS)

Wisdom, Cate; Vanoosten, Sarah Kay; Boone, Kyle W.; Khvostenko, Dmytro; Arnold, Paul M.; Snead, Malcolm L.; Tamerler, Candan

2016-08-01

Surgical site infection is a common cause of post-operative morbidity, often leading to implant loosening, ultimately requiring revision surgery, increased costs and worse surgical outcomes. Since implant failure starts at the implant surface, creating and controlling the bio-material interface will play a critical role in reducing infection while improving host cell-to-implant interaction. Here, we engineered a biomimetic interface based upon a chimeric peptide that incorporates a titanium binding peptide (TiBP) with an antimicrobial peptide (AMP) into a single molecule to direct binding to the implant surface and deliver an antimicrobial activity against S. mutans and S. epidermidis, two bacteria which are linked with clinical implant infections. To optimize antimicrobial activity, we investigated the design of the spacer domain separating the two functional domains of the chimeric peptide. Lengthening and changing the amino acid composition of the spacer resulted in an improvement of minimum inhibitory concentration by a three-fold against S. mutans. Surfaces coated with the chimeric peptide reduced dramatically the number of bacteria, with up to a nine-fold reduction for S. mutans and a 48-fold reduction for S. epidermidis. Ab initio predictions of antimicrobial activity based on structural features were confirmed. Host cell attachment and viability at the biomimetic interface were also improved compared to the untreated implant surface. Biomimetic interfaces formed with this chimeric peptide offer interminable potential by coupling antimicrobial and improved host cell responses to implantable titanium materials, and this peptide based approach can be extended to various biomaterials surfaces.

Shock Wave-Stimulated Periosteum for Cartilage Repair

DTIC Science & Technology

2013-12-01

were added to the Gtn-HPA prior to the gelation 6 process, at a cell density of 1×105 cells/ml. In the control groups, cells received no treatment...Mesenchymal Stem Cell Viability Viability test was performed 24 hours post- gelation using the Live/Dead assay. Viability/cytotoxicity kit was used (Molecular

Viability and infectivity of Ichthyophonus sp. in post-mortem Pacific herring, Clupea pallasii

USGS Publications Warehouse

Kocan, Richard M.; Hart, Lucas M.; Lewandowski, Naomi; Hershberger, Paul

2014-01-01

Ichthyophonus-infected Pacific herring, Clupea pallasii, were allowed to decompose in ambient seawater then serially sampled for 29 days to evaluate parasite viability and infectivity for Pacific staghorn sculpin, Leptocottus armatus. Ichthyophonus sp. was viable in decomposing herring tissues for at least 29 days post-mortem and could be transmitted via ingestion to sculpin for up to 5 days. The parasite underwent morphologic changes during the first 48 hr following death of the host that were similar to those previously reported, but as host tissue decomposition progressed, several previously un-described forms of the parasite were observed. The significance of long-term survival and continued morphologic transformation in the post-mortem host is unknown, but it could represent a saprozoic phase of the parasite life cycle that has survival value for Ichthyophonus sp.

The role of adrenergic activation on murine luteal cell viability and progesterone production.

PubMed

Wang, Jing; Tang, Min; Jiang, Huaide; Wu, Bing; Cai, Wei; Hu, Chuan; Bao, Riqiang; Dong, Qiming; Xiao, Li; Li, Gang; Zhang, Chunping

2016-09-15

Sympathetic innervations exist in mammalian CL. The action of catecholaminergic system on luteal cells has been the focus of a variety of studies. Norepinephrine (NE) increased progesterone secretion of cattle luteal cells by activating β-adrenoceptors. In this study, murine luteal cells were treated with NE and isoprenaline (ISO). We found that NE increased the viability of murine luteal cells and ISO decreased the viability of luteal cells. Both NE and ISO promoted the progesterone production. Nonselective β-adrenergic antagonist, propranolol reversed the effect of ISO on cell viability but did not reverse the effect of NE on cell viability. Propranolol blocked the influence of NE and ISO on progesterone production. These results reveal that the increase of luteal cell viability induced by NE is not dependent on β-adrenergic activation. α-Adrenergic activation possibly contributes to it. Both NE and ISO increased progesterone production through activating β-adrenergic receptor. Further study showed that CyclinD2 is involved in the increase of luteal cell induced by NE. 3β-Hydroxysteroid dehydrogenase, LHR, steroidogenic acute regulatory protein (StAR), and PGF2α contribute to the progesterone production induced by NE and ISO. Copyright © 2016 Elsevier Inc. All rights reserved.

Mechanical stimulation enhances integration in an in vitro model of cartilage repair.

PubMed

Theodoropoulos, John S; DeCroos, Amritha J N; Petrera, Massimo; Park, Sam; Kandel, Rita A

2016-06-01

(1) To characterize the effects of mechanical stimulation on the integration of a tissue-engineered construct in terms of histology, biochemistry and biomechanical properties; (2) to identify whether cells of the implant or host tissue were critical to implant integration; and (3) to study cells believed to be involved in lateral integration of tissue-engineered cartilage to host cartilage. We hypothesized that mechanical stimulation would enhance the integration of the repair implant with host cartilage in an in vitro integration model. Articular cartilage was harvested from 6- to 9-month-old bovine metacarpal-phalangeal joints. Constructs composed of tissue-engineered cartilage implanted into host cartilage were placed in spinner bioreactors and maintained on a magnetic stir plate at either 0 (static control) or 90 (experimental) rotations per minute (RPM). The constructs from both the static and spinner bioreactors were harvested after either 2 or 4 weeks of culture and evaluated histologically, biochemically, biomechanically and for gene expression. The extent and strength of integration between tissue-engineered cartilage and native cartilage improved significantly with both time and mechanical stimulation. Integration did not occur if the implant was not viable. The presence of stimulation led to a significant increase in collagen content in the integration zone between host and implant at 2 weeks. The gene profile of cells in the integration zone differs from host cartilage demonstrating an increase in the expression of membrane type 1 matrix metalloproteinase (MT1-MMP), aggrecan and type II collagen. This study shows that the integration of in vitro tissue-engineered implants with host tissue improves with mechanical stimulation. The findings of this study suggests that consideration should be given to implementing early loading (mechanical stimulation) into future in vivo studies investigating the long-term viability and integration of tissue-engineered cartilage for the treatment of cartilage injuries. This could simply be done through the use of continuous passive motion (CPM) in the post-operative period or through a more complex and structured rehabilitation program with a gradual increase in forces across the joint over time.

High-efficient and high-content cytotoxic recording via dynamic and continuous cell-based impedance biosensor technology.

PubMed

Hu, Ning; Fang, Jiaru; Zou, Ling; Wan, Hao; Pan, Yuxiang; Su, Kaiqi; Zhang, Xi; Wang, Ping

2016-10-01

Cell-based bioassays were effective method to assess the compound toxicity by cell viability, and the traditional label-based methods missed much information of cell growth due to endpoint detection, while the higher throughputs were demanded to obtain dynamic information. Cell-based biosensor methods can dynamically and continuously monitor with cell viability, however, the dynamic information was often ignored or seldom utilized in the toxin and drug assessment. Here, we reported a high-efficient and high-content cytotoxic recording method via dynamic and continuous cell-based impedance biosensor technology. The dynamic cell viability, inhibition ratio and growth rate were derived from the dynamic response curves from the cell-based impedance biosensor. The results showed that the biosensors has the dose-dependent manners to diarrhetic shellfish toxin, okadiac acid based on the analysis of the dynamic cell viability and cell growth status. Moreover, the throughputs of dynamic cytotoxicity were compared between cell-based biosensor methods and label-based endpoint methods. This cell-based impedance biosensor can provide a flexible, cost and label-efficient platform of cell viability assessment in the shellfish toxin screening fields.

Porcine parvovirus infection induces apoptosis in PK-15 cells through activation of p53 and mitochondria-mediated pathway

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Hongling; Huang, Yong; Du, Qian

Highlights: • PPV reduces PK-15 cells viability by inducing apoptosis. • PPV infection induces apoptosis through mitochondria-mediated pathway. • PPV infection activates p53 to regulate the mitochondria apoptotic signaling. - Abstract: Porcine parvovirus (PPV) infection has been reported to induce the cytopathic effects (CPE) in some special host cells and contribute the occurrence of porcine parvovirus disease, but the molecular mechanisms underlying PPV-induced CPE are not clear. In this study, we investigated the morphological and molecular changes of porcine kidney cell line (PK-15 cells) infected with PPV. The results showed that PPV infection inhibited the viability of PK-15 cells inmore » a time and concentration dependent manner. PPV infection induced typical apoptotic features including chromatin condensation, apoptotic body formation, nuclear fragmentation, and Annexin V-binding activity. Further studies showed that Bax was increased and translocated to mitochondria, whereas Bcl-2 was decreased in PPV-infected cells, which caused mitochondrial outer-membrane permeabilization, resulting in the release of mitochondrial cytochrome c, followed by caspase-9 and caspase-3 activation. However, the expression of Fas and Fas ligand (FasL) did not appear significant changes in the process of PPV-induced apoptosis. Moreover, PPV infection activated p53 signaling, which was involved in the activation of apoptotic signaling induced by PPV infection via regulation of Bax and Bcl-2. Taken together, our results demonstrated that PPV infection induced apoptosis in PK-15 cells through activation of p53 and mitochondria-mediated apoptosis pathway. This study may contribute to shed light on the molecular pathogenesis of PPV infection.« less

Effect of sodium hypochlorite on human pulp cells: an in vitro study

PubMed Central

Essner, Mark D.; Javed, Amjad; Eleazer, Paul D.

2014-01-01

Background The purpose of this study was to determine the effect of sodium hypochlorite (NaOCl) on human pulp cells to provide an aid in determining its optimum concentration in maintaining the viability of remaining pulp cells in the revascularization of immature permanent teeth with apical periodontitis. Study design Human pulp tissue cells taken from extracted third molars were plated, incubated, and subjected to various concentrations of NaOCl (0.33%, 0.16%, 0.08%, and 0.04%) for 5-, 10-, and 15-minute time intervals to simulate possible contact times in vivo. The Cell Titer–Glo Luminescent Cell Viability Assay was used to determine the number of viable cells present in culture following treatment. Results The results showed an increase in cell viability with the lowering of NaOCl concentration. The use of 0.04% NaOCl was similar to the control, indicating nearly complete preservation of cell viability at all time intervals tested. As sodium hypochlorite concentration increased from 0.04% to 0.33%, cell viability decreased correspondingly. Conclusions The results indicate that the lowest concentration of NaOCl tested did not affect the viability of cells. This may prove beneficial in developing a new treatment protocol to help preserve existing vital pulp cells in revascularization cases. PMID:21821446

Foot-and-mouth disease virus 5'-terminal S fragment is required for replication and modulation of the innate immune response in host cells.

PubMed

Kloc, Anna; Diaz-San Segundo, Fayna; Schafer, Elizabeth A; Rai, Devendra K; Kenney, Mary; de Los Santos, Teresa; Rieder, Elizabeth

2017-12-01

The S fragment of the FMDV 5' UTR is predicted to fold into a long stem-loop structure and it has been implicated in virus-host protein interactions. In this study, we report the minimal S fragment sequence required for virus viability and show a direct correlation between the extent of the S fragment deletion mutations and attenuated phenotypes. Furthermore, we provide novel insight into the role of the S fragment in modulating the host innate immune response. Importantly, in an FMDV mouse model system, all animals survive the inoculation with the live A 24 FMDV-S 4 mutant, containing a 164 nucleotide deletion in the upper S fragment loop, at a dose 1000 higher than the one causing lethality by parental A 24 FMDV, indicating that the A 24 FMDV-S 4 virus is highly attenuated in vivo. Additionally, mice exposed to high doses of live A 24 FMDV-S 4 virus are fully protected when challenged with parental A 24 FMDV virus. Published by Elsevier Inc.

Performance of the auxotrophic Saccharomyces cerevisiae BY4741 as host for the production of IL-1β in aerated fed-batch reactor: role of ACA supplementation, strain viability, and maintenance energy

PubMed Central

2009-01-01

Background Saccharomyces cerevisiae BY4741 is an auxotrophic commonly used strain. In this work it has been used as host for the expression and secretion of human interleukin-1β (IL1β), using the cell wall protein Pir4 as fusion partner. To achieve high cell density and, consequently, high product yield, BY4741 [PIR4-IL1β] was cultured in an aerated fed-batch reactor, using a defined mineral medium supplemented with casamino acids as ACA (auxotrophy-complementing amino acid) source. Also the S. cerevisiae mutant BY4741 Δyca1 [PIR4-IL1β], carrying the deletion of the YCA1 gene coding for a caspase-like protein involved in the apoptotic response, was cultured in aerated fed-batch reactor and compared to the parental strain, to test the effect of this mutation on strain robustness. Viability of the producer strains was examined during the runs and a mathematical model, which took into consideration the viable biomass present in the reactor and the glucose consumption for both growth and maintenance, was developed to describe and explain the time-course evolution of the process for both, the BY4741 parental and the BY4741 Δyca1 mutant strain. Results Our results show that the concentrations of ACA in the feeding solution, corresponding to those routinely used in the literature, are limiting for the growth of S. cerevisiae BY4741 [PIR4-IL1β] in fed-batch reactor. Even in the presence of a proper ACA supplementation, S. cerevisiae BY4741 [PIR4-IL1β] did not achieve a high cell density. The Δyca1 deletion did not have a beneficial effect on the overall performance of the strain, but it had a clear effect on its viability, which was not impaired during fed-batch operations, as shown by the kd value (0.0045 h-1), negligible if compared to that of the parental strain (0.028 h-1). However, independently of their robustness, both the parental and the Δyca1 mutant ceased to grow early during fed-batch runs, both strains using most of the available carbon source for maintenance, rather than for further proliferation. The mathematical model used evidenced that the energy demand for maintenance was even higher in the case of the Δyca1 mutant, accounting for the growth arrest observed despite the fact that cell viability remained comparatively high. Conclusions The paper points out the relevance of a proper ACA formulation for the outcome of a fed-batch reactor growth carried out with S. cerevisiae BY4741 [PIR4-IL1β] strain and shows the sensitivity of this commonly used auxotrophic strain to aerated fed-batch operations. A Δyca1 disruption was able to reduce the loss of viability, but not to improve the overall performance of the process. A mathematical model has been developed that is able to describe the behaviour of both the parental and mutant producer strain during fed-batch runs, and evidence the role played by the energy demand for maintenance in the outcome of the process. PMID:20042083

How type 1 fimbriae help Escherichia coli to evade extracellular antibiotics

PubMed Central

Avalos Vizcarra, Ima; Hosseini, Vahid; Kollmannsberger, Philip; Meier, Stefanie; Weber, Stefan S.; Arnoldini, Markus; Ackermann, Martin; Vogel, Viola

2016-01-01

To survive antibiotics, bacteria use two different strategies: counteracting antibiotic effects by expression of resistance genes or evading their effects e.g. by persisting inside host cells. Since bacterial adhesins provide access to the shielded, intracellular niche and the adhesin type 1 fimbriae increases bacterial survival chances inside macrophages, we asked if fimbriae also influenced survival by antibiotic evasion. Combined gentamicin survival assays, flow cytometry, single cell microscopy and kinetic modeling of dose response curves showed that type 1 fimbriae increased the adhesion and internalization by macrophages. This was caused by strongly decreased off-rates and affected the number of intracellular bacteria but not the macrophage viability and morphology. Fimbriae thus promote antibiotic evasion which is particularly relevant in the context of chronic infections. PMID:26728082

Monitoring change in refractive index of cytosol of animal cells on affinity surface under osmotic stimulus for label-free measurement of viability.

PubMed

Park, Jina; Jin, Sung Il; Kim, Hyung Min; Ahn, Junhyoung; Kim, Yeon-Gu; Lee, Eun Gyo; Kim, Min-Gon; Shin, Yong-Beom

2015-02-15

We demonstrated that a metal-clad waveguide (MCW)-based biosensor can be applied to label-free measurements of viability of adherent animal cells with osmotic stimulation in real time. After Chinese hamster ovary (CHO) and human embryonic kidney cell 293 (HEK293) cells were attached to a Concanavalin A (Con A)-modified sensor surface, the magnitudes of cell responses to non-isotonic stimulation were compared between live and dead cells. The live cells exhibited a change in the refractive index (RI) of the cytosol caused by a redistribution of water through the cell membrane, which was induced by the osmotic stimulus, but the dead cells did not. Moreover, the normalized change in the RI measured via the MCW sensor was linearly proportional to the viability of attached cells and the resolution in monitoring cell viability was about 0.079%. Therefore, the viability of attached animal cells can be measured without labels by observing the relative differences in the RI of cytosol in isotonic and non-isotonic buffers. Copyright © 2014 Elsevier B.V. All rights reserved.

Role of nanostructured gold surfaces on monocyte activation and Staphylococcus epidermidis biofilm formation

PubMed Central

Svensson, Sara; Forsberg, Magnus; Hulander, Mats; Vazirisani, Forugh; Palmquist, Anders; Lausmaa, Jukka; Thomsen, Peter; Trobos, Margarita

2014-01-01

The role of material surface properties in the direct interaction with bacteria and the indirect route via host defense cells is not fully understood. Recently, it was suggested that nanostructured implant surfaces possess antimicrobial properties. In the current study, the adhesion and biofilm formation of Staphylococcus epidermidis and human monocyte adhesion and activation were studied separately and in coculture in different in vitro models using smooth gold and well-defined nanostructured gold surfaces. Two polystyrene surfaces were used as controls in the monocyte experiments. Fluorescent viability staining demonstrated a reduction in the viability of S. epidermidis close to the nanostructured gold surface, whereas the smooth gold correlated with more live biofilm. The results were supported by scanning electron microscopy observations, showing higher biofilm tower formations and more mature biofilms on smooth gold compared with nanostructured gold. Unstimulated monocytes on the different substrates demonstrated low activation, reduced gene expression of pro- and anti-inflammatory cytokines, and low cytokine secretion. In contrast, stimulation with opsonized zymosan or opsonized live S. epidermidis for 1 hour significantly increased the production of reactive oxygen species, the gene expression of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), IL-6, and IL-10, as well as the secretion of TNF-α, demonstrating the ability of the cells to elicit a response and actively phagocytose prey. In addition, cells cultured on the smooth gold and the nanostructured gold displayed a different adhesion pattern and a more rapid oxidative burst than those cultured on polystyrene upon stimulation. We conclude that S. epidermidis decreased its viability initially when adhering to nanostructured surfaces compared with smooth gold surfaces, especially in the bacterial cell layers closest to the surface. In contrast, material surface properties neither strongly promoted nor attenuated the activity of monocytes when exposed to zymosan particles or S. epidermidis. PMID:24550671

Label-Free, Flow-Imaging Methods for Determination of Cell Concentration and Viability.

PubMed

Sediq, A S; Klem, R; Nejadnik, M R; Meij, P; Jiskoot, Wim

2018-05-30

To investigate the potential of two flow imaging microscopy (FIM) techniques (Micro-Flow Imaging (MFI) and FlowCAM) to determine total cell concentration and cell viability. B-lineage acute lymphoblastic leukemia (B-ALL) cells of 2 different donors were exposed to ambient conditions. Samples were taken at different days and measured with MFI, FlowCAM, hemocytometry and automated cell counting. Dead and live cells from a fresh B-ALL cell suspension were fractionated by flow cytometry in order to derive software filters based on morphological parameters of separate cell populations with MFI and FlowCAM. The filter sets were used to assess cell viability in the measured samples. All techniques gave fairly similar cell concentration values over the whole incubation period. MFI showed to be superior with respect to precision, whereas FlowCAM provided particle images with a higher resolution. Moreover, both FIM methods were able to provide similar results for cell viability as the conventional methods (hemocytometry and automated cell counting). FIM-based methods may be advantageous over conventional cell methods for determining total cell concentration and cell viability, as FIM measures much larger sample volumes, does not require labeling, is less laborious and provides images of individual cells.

Mce4A protein of Mycobacterium tuberculosis induces pro inflammatory cytokine response leading to macrophage apoptosis in a TNF-α dependent manner.

PubMed

Saini, Neeraj Kumar; Sinha, Rajesh; Singh, Pooja; Sharma, Monika; Pathak, Rakesh; Rathor, Nisha; Varma-Basil, Mandira; Bose, Mridula

2016-11-01

Mycobacterium tuberculosis subverts the host immune response through numerous immune-evasion strategies. Apoptosis has been identified as one such mechanism and has been well studied in M. tuberculosis infection. Here, we demonstrate that the Mce4A protein of mce4 operon is involved in the induction of host cell apoptosis. Earlier we have shown that the Mce4A was required for the invasion and survival of M. tuberculosis. In this report we present evidence to establish a role for Mce4A in the modulation of THP-1 cell survival. Recombinant Mce4A was expressed and purified from Escherichia coli as inclusion bodies and then refolded. Viability of THP-1 cells decreased in a dose-dependent manner when treated with Mce4A. The secretion of pro-inflammatory cytokines like tumor necrosis factor (TNF-α) or interferon gamma (IFN-γ), and enhanced nitric oxide release was observed when the THP-1 cells, were treated with Mce4A protein. The Mce4A induced apoptosis of the THP-1 cells was TNF-α dependent since blocking with anti TNF-α antibody abrogated this phenomenon. Collectively, these data suggest that Mce4A can induce the THP-1 cells to undergo apoptosis which primarily follows a TNF- α dependent pathway. Copyright © 2016 Elsevier Ltd. All rights reserved.

Sporotrichosis between 1898 and 2017: The evolution of knowledge on a changeable disease and on emerging etiological agents.

PubMed

Lopes-Bezerra, Leila M; Mora-Montes, Hector M; Zhang, Yu; Nino-Vega, Gustavo; Rodrigues, Anderson Messias; de Camargo, Zoilo Pires; de Hoog, Sybren

2018-04-01

The description of cryptic species with different pathogenic potentials has changed the perspectives on sporotrichosis. Sporothrix schenckii causes a benign chronic subcutaneous mycosis, Sporothrix brasiliensis is highly virulent, and Sporothrix globosa mainly causes fixed cutaneous lesions. Furthermore, S. brasiliensis is the prevalent species related to cat-transmitted sporotrichosis. Sources of infection, transmission, and distribution patterns also differ between species, and variability differs between species because of different degrees of clonality. The present review article will cover several aspects of the biology of clinically relevant agents of sporotrichosis, including epidemiological aspects of emerging species. Genomic information of Sporothrix spp. is also discussed. The cell wall is an essential structure for cell viability, interaction with the environment, and the host immune cells and contains several macromolecules involved in virulence. Due to its importance, aspects of glycosylation and cell wall polysaccharides are reviewed. Recent genome data and bioinformatics analyses helped to identify specific enzymes of the biosynthetic glycosylation routes, with no homologs in mammalian cells, which can be putative targets for development of antifungal drugs. A diversity of molecular techniques is available for the recognition of the clinically relevant species of Sporothrix. Furthermore, antigens identified as diagnostic markers and putative vaccine candidates are described. Cell-mediated immunity plays a key role in controlling infection, but Sporothrix species differ in their interaction with the host. The adaptive branch of the immune response is essential for appropriate control of infection.

The effect of simultaneous exposure of HEMn-DP and HEMn-LP melanocytes to nicotine and UV-radiation on the cell viability and melanogenesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Delijewski, Marcin; Wrześniok, Dorota; Beberok, Ar

Nicotine is a main compound of tobacco plants and may affect more than a billion people all over the world that are permanently exposed to nicotine from cigarettes, various forms of smoking cessation therapies, electronic cigarettes or second-hand smoke. It is known that nicotine forms complexes with melanin what may lead to accumulation of this alkaloid in tissues of living organisms containing the pigment. This may affect the viability of cells and process of melanin biosynthesis that takes place in melanocytes. Although UV radiation is known to be a particular inductor of melanin biosynthesis, its simultaneous effect with nicotine onmore » this process as well as the viability of human cells containing melanin have not been assessed so far. The aim of this study was to examine the simultaneous impact of nicotine and UV radiation on viability and melanogenesis in cultured normal human melanocytes dark (HEMn-DP) and light (HEMn-LP) pigmented. Nicotine together with UV radiation induced concentration-dependent loss in melanocytes viability. The higher cell loss was observed in dark pigmented melanocytes in comparison to light pigmented cells. Simultaneous exposure of cells to nicotine and UV radiation also caused changes in melanization process in both tested cell lines. The data suggest that simultaneous exposure of melanocytes to nicotine and UV radiation up-regulates melanogenesis and affects cell viability. Observed processes are more pronounced in dark pigmented cells. - Highlights: • Nicotine and UVA induced concentration-dependent loss in melanocytes viability. • Nicotine and UVA modulated melanization process in melanocytes. • Changes in viability and melanization were more pronounced in dark pigmented cells.« less

Assessment of cell concentration and viability of isolated hepatocytes using flow cytometry.

PubMed

Wigg, Alan J; Phillips, John W; Wheatland, Loretta; Berry, Michael N

2003-06-01

The assessment of cell concentration and viability of freshly isolated hepatocyte preparations has been traditionally performed using manual counting with a Neubauer counting chamber and staining for trypan blue exclusion. Despite the simple and rapid nature of this assessment, concerns about the accuracy of these methods exist. Simple flow cytometry techniques which determine cell concentration and viability are available yet surprisingly have not been extensively used or validated with isolated hepatocyte preparations. We therefore investigated the use of flow cytometry using TRUCOUNT Tubes and propidium iodide staining to measure cell concentration and viability of isolated rat hepatocytes in suspension. Analysis using TRUCOUNT Tubes provided more accurate and reproducible measurement of cell concentration than manual cell counting. Hepatocyte viability, assessed using propidium iodide, correlated more closely than did trypan blue exclusion with all indicators of hepatocyte integrity and function measured (lactate dehydrogenase leakage, cytochrome p450 content, cellular ATP concentration, ammonia and lactate removal, urea and albumin synthesis). We conclude that flow cytometry techniques can be used to measure cell concentration and viability of isolated hepatocyte preparations. The techniques are simple, rapid, and more accurate than manual cell counting and trypan blue staining and the results are not affected by protein-containing media.

Isolated and Community Contexts Produce Distinct Responses by Host Plants to the Presence of Ant-Aphid Interaction: Plant Productivity and Seed Viability.

PubMed

Canedo-Júnior, Ernesto Oliveira; Santiago, Graziele Silva; Zurlo, Luana Fonseca; Ribas, Carla Rodrigues; Carvalho, Rafaela Pereira; Alves, Guilherme Pereira; Carvalho, Mariana Comanucci Silva; Souza, Brígida

2017-01-01

Ant-aphid interactions may affect host plants in several ways, however, most studies measure only the amount of fruit and seed produced, and do not test seed viability. Therefore, the aim of this study was to assess the effects of the presence of ant-aphid interactions upon host plant productivity and seed viability in two different contexts: isolated and within an arthropod community. For this purpose we tested the hypothesis that in both isolated and community contexts, the presence of an ant-aphid interaction will have a positive effect on fruit and seed production, seed biomass and rate of seed germination, and a negative effect on abnormal seedling rates, in comparison to plants without ants. We performed a field mesocosm experiment containing five treatments: Ant-aphid, Aphid, Community, Ant-free community and Control. We counted fruits and seeds produced by each treatment, and conducted experiments for seed biomass and germinability. We found that in the community context the presence of an ant-aphid interaction negatively affected fruit and seed production. We think this may be because aphid attendance by tending-ants promotes aphid damage to the host plant, but without an affect on seed weight and viability. On the other hand, when isolated, the presence of an ant-aphid interaction positively affected fruit and seed production. These positive effects are related to the cleaning services offered to aphids by tending-ants, which prevent the development of saprophytic fungi on the surface of leaves, which would cause a decrease in photosynthetic rates. Our study is important because we evaluated some parameters of plant fitness that have not been addressed very well by other studies involving the effects of ant-aphid interactions mainly on plants with short life cycles. Lastly, our context dependent approach sheds new light on how ecological interactions can vary among different methods of crop management.

Isolated and Community Contexts Produce Distinct Responses by Host Plants to the Presence of Ant-Aphid Interaction: Plant Productivity and Seed Viability

PubMed Central

Santiago, Graziele Silva; Zurlo, Luana Fonseca; Ribas, Carla Rodrigues; Carvalho, Rafaela Pereira; Alves, Guilherme Pereira; Carvalho, Mariana Comanucci Silva; Souza, Brígida

2017-01-01

Ant-aphid interactions may affect host plants in several ways, however, most studies measure only the amount of fruit and seed produced, and do not test seed viability. Therefore, the aim of this study was to assess the effects of the presence of ant-aphid interactions upon host plant productivity and seed viability in two different contexts: isolated and within an arthropod community. For this purpose we tested the hypothesis that in both isolated and community contexts, the presence of an ant-aphid interaction will have a positive effect on fruit and seed production, seed biomass and rate of seed germination, and a negative effect on abnormal seedling rates, in comparison to plants without ants. We performed a field mesocosm experiment containing five treatments: Ant-aphid, Aphid, Community, Ant-free community and Control. We counted fruits and seeds produced by each treatment, and conducted experiments for seed biomass and germinability. We found that in the community context the presence of an ant-aphid interaction negatively affected fruit and seed production. We think this may be because aphid attendance by tending-ants promotes aphid damage to the host plant, but without an affect on seed weight and viability. On the other hand, when isolated, the presence of an ant-aphid interaction positively affected fruit and seed production. These positive effects are related to the cleaning services offered to aphids by tending-ants, which prevent the development of saprophytic fungi on the surface of leaves, which would cause a decrease in photosynthetic rates. Our study is important because we evaluated some parameters of plant fitness that have not been addressed very well by other studies involving the effects of ant-aphid interactions mainly on plants with short life cycles. Lastly, our context dependent approach sheds new light on how ecological interactions can vary among different methods of crop management. PMID:28141849

Coconut milk and probiotic milk as storage media to maintain periodontal ligament cell viability: an in vitro study.

PubMed

Saini, Divya; Gadicherla, Prahlad; Chandra, Prakash; Anandakrishna, Latha

2017-06-01

The viability of periodontal ligament (PDL) cells is a significant determinant of the long-term prognosis of replanted avulsed teeth. A storage medium is often required to maintain the viability of these cells during the extra-alveolar period. Many studies have been carried out to search for the most suitable storage medium for avulsed teeth, but an ideal solution has not yet been found. The purpose of the study was to compare and analyze the ability of coconut milk and probiotic milk to maintain PDL cell viability. In an in vitro setting, 69 caries free human premolars with normal periodontium that had been extracted for orthodontic purposes were randomly divided into two experimental groups on the basis of storage media used (i.e., coconut milk or probiotic milk) and a Hanks' balanced salt solution (HBSS) control group (23 samples per group). Immediately after extraction, the teeth were stored dry for 20 min and then immersed for 30 min in one of the storage media. The teeth were then subjected to collagenase-dispase assay and labeled with 0.5% trypan blue staining solution for determination of cell viability. The number of viable cells was counted under a light microscope and statistically analyzed using anova and post hoc Tukey test (P ≤ 0.05). Statistical analysis demonstrated there was a significant difference (P < 0.001) between coconut milk and probiotic milk as well as HBSS in maintaining cell viability. However, there was no significant difference between probiotic milk and HBSS in ability to maintain PDL cell viability (P > 0.05). Coconut milk may not be suitable as an interim transport media due to poor maintenance of cell viability. However, probiotic milk was able to maintain PDL cell viability as well as HBSS. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Bioactive compounds or metabolites from black raspberries modulate T lymphocyte proliferation, myeloid cell differentiation and Jak/STAT signaling

PubMed Central

Mace, Thomas A.; King, Samantha A.; Ameen, Zeenath; Elnaggar, Omar; Young, Gregory; Riedl, Kenneth M.; Schwartz, Steven J.; Clinton, Steven K.; Knobloch, Thomas J.; Weghorst, Christopher M.; Lesinski, Gregory B.

2014-01-01

Bioactive phyotochemicals from natural products, such as black raspberries (BRB; Rubus occidentalis) have direct anti-cancer properties on malignant cells in culture and in xenograft models. BRB components inhibit cancer progression in more complex rodent carcinogenesis models. Although mechanistic targets for BRB phytochemicals in cancer cells are beginning to emerge, the potential role in modulating host immune processes impacting cancer have not been systematically examined. We hypothesized that BRB contain compounds capable of eliciting potent immunomodulatory properties that impact cellular mediators relevant to chronic inflammation and tumor progression. We studied both an ethanol extract from black raspberries (BRB-E) containing a diverse mixture of phytochemicals and two abundant phytochemical metabolites of BRB produced upon ingestion (Cyanidin-3-Rutinoside, C3R; Quercitin-3-Rutinoside, Q3R). BRB-E inhibited proliferation and viability of CD3/CD28 activated human CD4+ and CD8+ T lymphocytes. BRB-E also limited in vitro expansion of myeloid-derived suppressor cells (MDSC) and their suppressive capacity. Pre-treatment of immune cells with BRB-E attenuated IL-6-mediated phosphorylation of signal transducer and activator of transcription-3 (STAT3) and IL-2 induced STAT5 phosphorylation. In contrast, pre-treatment of immune cells with the C3R and Q3R metabolites inhibited MDSC expansion, IL-6-mediated STAT3 signaling, but not IL-2 induced STAT5 phosphorylation and were less potent inhibitors of T cell viability. Together these data indicate that BRB extracts and their physiologically-relevant metabolites contain phytochemicals that affect immune processes relevant to carcinogenesis and immunotherapy. Furthermore, specific BRB components and their metabolites may be a source of lead compounds for drug development that exhibit targeted immunological outcomes or inhibition of specific STAT-regulated signaling pathways. PMID:24893859

Potential Role for a Carbohydrate Moiety in Anti-Candida Activity of Human Oral Epithelial Cells

PubMed Central

Steele, Chad; Leigh, Janet; Swoboda, Rolf; Ozenci, Hatice; Fidel, Paul L.

2001-01-01

Candida albicans is both a commensal and a pathogen at the oral mucosa. Although an intricate network of host defense mechanisms are expected for protection against oropharyngeal candidiasis, anti-Candida host defense mechanisms at the oral mucosa are poorly understood. Our laboratory recently showed that primary epithelial cells from human oral mucosa, as well as an oral epithelial cell line, inhibit the growth of blastoconidia and/or hyphal phases of several Candida species in vitro with a requirement for cell contact and with no demonstrable role for soluble factors. In the present study, we show that oral epithelial cell-mediated anti-Candida activity is resistant to gamma-irradiation and is not mediated by phagocytosis, nitric oxide, hydrogen peroxide, and superoxide oxidative inhibitory pathways or by nonoxidative components such as soluble defensin and calprotectin peptides. In contrast, epithelial cell-mediated anti-Candida activity was sensitive to heat, paraformaldehyde fixation, and detergents, but these treatments were accompanied by a significant loss in epithelial cell viability. Treatments that removed existing membrane protein or lipid moieties in the presence or absence of protein synthesis inhibitors had no effect on epithelial cell inhibitory activity. In contrast, the epithelial cell-mediated anti-Candida activity was abrogated after treatment of the epithelial cells with periodic acid, suggesting a role for carbohydrates. Adherence of C. albicans to oral epithelial cells was unaffected, indicating that the carbohydrate moiety is exclusively associated with the growth inhibition activity. Subsequent studies that evaluated specific membrane carbohydrate moieties, however, showed no role for sulfated polysaccharides, sialic acid residues, or glucose- and mannose-containing carbohydrates. These results suggest that oral epithelial cell-mediated anti-Candida activity occurs exclusively with viable epithelial cells through contact with C. albicans by an as-yet-undefined carbohydrate moiety. PMID:11598085

Viability of human fibroblasts in coconut water as a storage medium.

PubMed

Moreira-Neto, J J S; Gondim, J O; Raddi, M S G; Pansani, C A

2009-09-01

To evaluate the effectiveness of a new storage medium for avulsed teeth, coconut water, in maintaining the viability of human fibroblasts. Cell viability after different time periods was evaluated in the following storage media: coconut water, coconut water with sodium bicarbonate, milk, saline and still mineral water. Human fibroblasts were seeded in Eagle's minimal essential medium (EMEM) supplemented with 7.5% foetal calf serum. After trypsinisation, 100 microL of culture medium containing approximately 10(4) cells mL(-1) were collected and pipetted into the wells of 96-well plates, which were incubated overnight in 5% CO(2) and 95% air mixture at 37 degrees C. EMEM was then replaced by the storage media and the plates were incubated at 37 degrees C for 1, 2 and 4 h. Cell viability was determined using the neutral red assay. The proportions of viable cells after exposure to the storage media were analysed statistically by anova and the least significant difference (LSD) test (alpha = 5%). Milk had the greatest capacity to maintain cell viability (P < 0.05), followed by coconut water with sodium bicarbonate and saline. Coconut water was significantly worse at maintaining cell viability compared to milk, coconut water with sodium bicarbonate and saline. The smallest number of viable cells was observed for mineral water (P < 0.05). Coconut water was worse than milk in maintaining human fibroblast cell viability.

BID is a critical factor controlling cell viability regulated by IFN-α.

PubMed

Tsuno, Takaya; Mejido, Josef; Zhao, Tongmao; Phillips, Terry; Myers, Timothy G; Bekisz, Joseph; Zoon, Kathryn C

2012-01-01

Clinical applications of human interferon (IFN)-α have met with varying degrees of success. Nevertheless, key molecules in cell viability regulated by IFN-α have not been clearly identified. Our previous study indicated that IFN (α, β, and ω) receptor (IFNAR) 1/2- and IFN regulatory factor 9-RNA interference (RNAi) completely restored cell viability after IFN-α treatment in human ovarian adenocarcinoma OVCAR3 cells sensitive to IFN-α. In this study, IFNAR1/2- and IFN regulatory factor 9-RNAi inhibited the gene expression of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), but not of Fas ligand, after IFN-α treatment. In fact, TRAIL but not Fas ligand inhibited the viability of OVCAR3 cells. IFN-α notably upregulated the levels of TRAIL protein in the supernatant and on the membrane of OVCAR3 cells. After TRAIL signaling, caspase 8 inhibitor and BH3 interacting domain death agonist (BID)-RNAi significantly restored cell viability in response to IFN-α and TRAIL in OVCAR3 cells. Furthermore, BID-RNAi prevented both IFN-α and TRAIL from collapsing the mitochondrial membrane potential (ΔΨm). Finally, we provided important evidence that BID overexpression led to significant inhibition of cell viability after IFN-α or TRAIL treatments in human lung carcinoma A549 cells resistant to IFN-α. Thus, this study suggests that BID is crucial for cell viability regulated by IFN-α which can induce mitochondria-mediated apoptosis, indicating a notable potential to be a targeted therapy for IFN-α resistant tumors.

Effect of bioink properties on printability and cell viability for 3D bioplotting of embryonic stem cells.

PubMed

Ouyang, Liliang; Yao, Rui; Zhao, Yu; Sun, Wei

2016-09-16

3D cell printing is an emerging technology for fabricating complex cell-laden constructs with precise and pre-designed geometry, structure and composition to overcome the limitations of 2D cell culture and conventional tissue engineering scaffold technology. This technology enables spatial manipulation of cells and biomaterials, also referred to as 'bioink', and thus allows study of cellular interactions in a 3D microenvironment and/or in the formation of functional tissues and organs. Recently, many efforts have been made to develop new bioinks and to apply more cell sources for better biocompatibility and biofunctionality. However, the influences of printing parameters on the shape fidelity of 3D constructs as well as on cell viability after the cell printing process have been poorly characterized. Furthermore, parameter optimization based on a specific cell type might not be suitable for other types of cells, especially cells with high sensibility. In this study, we systematically studied the influence of bioink properties and printing parameters on bioink printability and embryonic stem cell (ESC) viability in the process of extrusion-based cell printing, also known as bioplotting. A novel method was established to determine suitable conditions for bioplotting ESCs to achieve both good printability and high cell viability. The rheological properties of gelatin/alginate bioinks were evaluated to determine the gelation properties under different bioink compositions, printing temperatures and holding times. The bioink printability was characterized by a newly developed semi-quantitative method. The results demonstrated that bioinks with longer gelation times would result in poorer printability. The live/dead assay showed that ESC viability increased with higher printing temperatures and lower gelatin concentrations. Furthermore, an exponential relationship was obtained between ESC viability and induced shear stress. By defining the proper printability and acceptable viability ranges, a combined parameters region was obtained. This study provides guidance for parameter optimization and the fine-tuning of 3D cell printing processes regarding both bioink printability and cell viability after bioplotting, especially for easily damaged cells, like ESCs.

Directing the assembly of nanostructured films with living cells

NASA Astrophysics Data System (ADS)

Brinker, C. Jeffrey

2007-03-01

This talk describes our recent discovery of the ability of living cells to organize extended nanostructures and nano-objects in a manner that creates a unique, highly biocompatible nano//bio interface (Science 313, 337-340, 2006). We find that, using short chain phospholipids to direct the formation of thin film silica mesophases during evaporation-induced self-assembly, the introduction of cells (so far yeast and bacteria) alters profoundly the inorganic self-assembly pathway. Cells actively organize around themselves an ordered, multilayered lipid-membrane that interfaces coherently with a lipid-templated silica mesophase. This bio/nano interface is unique in that it withstands drying (even evacuation) without cracking or the development of tensile stresses -- yet it maintains accessibility to molecules, proteins/antibodies, plasmids, etc - introduced into the 3D silica host. Additionally cell viability is preserved for weeks to months in the absence of buffer, making these constructs useful as standalone cell-based sensors. The bio/nano interfaces we describe do not form `passively' -- rather they are a consequence of the cell's ability to sense and actively respond to external stimuli. During EISA, solvent evaporation concentrates the extracellular environment in osmolytes. In response to this hyperosmotic stress, the cells release water, creating a gradient in pH, which is maintained within the adjoining nanostructured host and serves to localize lipids, proteins, plasmids, lipidized nanocrystals, and a variety of other components at the cellular surface. This active organization of the bio/nano interface can be accomplished during ink-jet printing or selective wetting -- processes allowing patterning of cellular arrays - and even spatially-defined genetic modification.

In vitro cell imaging using multifunctional small sized KGdF4:Yb3+,Er3+ upconverting nanoparticles synthesized by a one-pot solvothermal process

NASA Astrophysics Data System (ADS)

Wong, Hon-Tung; Tsang, Ming-Kiu; Chan, Chi-Fai; Wong, Ka-Leung; Fei, Bin; Hao, Jianhua

2013-03-01

Multifunctional KGdF4:18%Yb3+,2%Er3+ nanoparticles with upconversion fluorescence and paramagnetism are synthesized. The average sizes of the nanoparticles capped with branched polyethyleneimine (PEI) and 6-aminocaproic acid (6AA) are ~14 and ~13 nm, respectively. Our KGdF4 host does not exhibit any phase change with the decrease of particle size, which can prevent the detrimental significant decrease in upconversion luminescence caused by this effect observed in the well-known NaYF4 host. The branched PEI and 6AA capping ligands endow our nanoparticles with water-dispersibility and biocompatibility, which can favor internalization of our nanoparticles into the cytoplasm of HeLa cells and relatively high cell viability. The strong upconversion luminescence detected at the cytoplasm of HeLa cells incubated with the branched PEI-capped nanoparticles is probably attributed to the reported high efficiency of cellular uptake. The magnetic mass susceptibility of our nanoparticle is 8.62 × 10-5 emu g-1 Oe-1. This is the highest value ever reported in trivalent rare-earth ion-doped KGdF4 nanoparticles of small size (<=14 nm), and is very close to that of nanoparticles used as T1 contrast agents in magnetic resonance imaging. These suggest the potential of our KGdF4:Yb3+,Er3+ nanoparticles as small-sized multifunctional bioprobes.

Histone deacetylases inhibitors effects on Cryptococcus neoformans major virulence phenotypes

PubMed Central

Brandão, Fabiana AS; Derengowski, Lorena S; Albuquerque, Patrícia; Nicola, André M; Silva-Pereira, Ildinete; Poças-Fonseca, Marcio J

2015-01-01

Cryptococcus neoformans undergoes phenotypical changes during host infection in order to promote persistence and survival. Studies have demonstrated that such adaptations require alterations in gene transcription networks by distinct mechanisms. Drugs such as the histone deacetylases inhibitors (HDACi) Sodium Butyrate (NaBut) and Trichostatin A (TSA) can alter the chromatin conformation and have been used to modulate epigenetic states in the treatment of diseases such as cancer. In this work, we have studied the effect of NaBut and TSA on the expression of C. neoformans major virulence phenotypes and on the survival rate of an animal model infected with drugs-treated yeasts. Both drugs affected fungal growth at 37°C more intensely than at 30°C; nonetheless, drugs did not affect cell viability at the concentrations we studied. HDACi also provoked the reduction of the fungal capsule expansion. Phospholipases enzyme activity decreased; mating process and melanin synthesis were also affected by both inhibitors. NaBut led to an increase in the population of cells in G2/M. Treated yeast cells, which were washed in order to remove the drugs from the culture medium prior to the inoculation in the Galleria mellonela infection model, did not cause significant difference at the host survival curve when compared to non-treated cells. Overall, NaBut effects on the impairment of C. neoformans main virulence factors were more intense and stable than the TSA effects. PMID:26103530

Effect of the oncolytic ECHO-7 virus Rigvir® on the viability of cell lines of human origin in vitro.

PubMed

Tilgase, Andra; Patetko, Liene; Blāķe, Ilze; Ramata-Stunda, Anna; Borodušķis, Mārtiņš; Alberts, Pēteris

2018-01-01

Background: The role of oncolytic viruses in cancer treatment is increasingly studied. The first oncolytic virus (Rigvir®, ECHO-7) was registered in Latvia over a decade ago. In a recent retrospective study Rigvir® decreased mortality 4.39-6.57-fold in stage IB-IIC melanoma patients. The aims of the present study are to test the effect of Rigvir® on cell line viability in vitro and to visualize the cellular presence of Rigvir® by immunocytochemistry. Methods: The cytolytic effect of Rigvir® on the viability of FM-9, RD, AGS, A549, HDFa, HPAF‑II, MSC, MCF7, HaCaT, and Sk-Mel-28 cell lines was measured using live cell imaging. PBMC viability was measured using flow cytometry. The presence of ECHO-7 virus was visualized using immunocytochemistry. Statistical difference between treatment groups was calculated using two-way ANOVA. Results: Rigvir® (10%, volume/volume) reduced cell viability in FM-9, RD, AGS, A549, HDFa, HPAF‑II and MSC cell lines by 67-100%. HaCaT cell viability was partly affected while Rigvir® had no effect on MCF7, Sk-Mel-28 and PBMC viability. Detection of ECHO-7 by immunocytochemistry in FM-9, RD, AGS, A549, HDFa, HPAF-II and Sk-Mel-28 cell lines suggests that the presence of Rigvir® in the cells preceded or coincided with the time of reduction of cell viability. Rigvir® (10%) had no effect on live PBMC count. Conclusions: The results suggest that Rigvir® in vitro reduces the viability of cells of human melanoma, rhabdomyosarcoma, gastric adenocarcinoma, lung carcinoma, pancreas adenocarcinoma but not in PBMC. The presence of Rigvir® in the sensitive cells was confirmed using anti-ECHO-7 antibodies. The present results suggest that a mechanism of action for the clinical benefit of Rigvir® is its cytolytic properties. The present results suggest that the effect of Rigvir® could be tested in other cancers besides melanoma. Further studies of possible Rigvir® entry receptors are needed.

Innovative Microcapsules for Pancreatic β-Cells Harvested from Mature Double-Transgenic Mice: Cell Imaging, Viability, Induced Glucose-Stimulated Insulin Measurements and Proinflammatory Cytokines Analysis.

PubMed

Mooranian, Armin; Tackechi, Ryu; Jamieson, Emma; Morahan, Grant; Al-Salami, Hani

2017-06-01

Recently we demonstrated that microencapsulation of a murine pancreatic β-cell line using an alginate-ursodeoxycholic acid (UDCA) matrix produced microcapsules with good stability and cell viability. In this study, we investigated if translation of this formulation to microencapsulation of primary β-cells harvested from mature double-transgenic healthy mice would also generate stable microcapsules with good cell viability. Islets of Langerhans were isolated from Ngn3-GFP/RIP-DsRED mice by intraductal collagenase P digestion and density gradient centrifugation, dissociated into single cells and the β-cell population purified by Fluorescence Activated Cell Sorting. β-cells were microencapsulated using either alginate-poly-l-ornithine (F1; control) or alginate-poly-l-ornithine-UDCA (F2; test) formulations. Microcapsules were microscopically examined and microencapsulated cells were analyzed for viability, insulin and cytokine release, 2 days post-microencapsulation. Microcapsules showed good uniformity and morphological characteristics and even cell distribution within microcapsules with or without UDCA. Two days post microencapsulation cell viability, mitochondrial ATP and insulin production were shown to be optimized in the presence of UDCA whilst production of the proinflammatory cytokine IL-1β was reduced. Contradictory to our previous studies, UDCA did not reduce production of any other pro-inflammatory biomarkers. These results suggest that UDCA incorporation improves microcapsules' physical and morphological characteristics and improves the viability and function of encapsulated mature primary pancreatic β-cells.

Laser and Non-Coherent Light Effect on Peripheral Blood Normal and Acute Lymphoblastic Leukemic Cells by Using Different Types of Photosensitizers

NASA Astrophysics Data System (ADS)

El Batanouny, Mohamed H.; Khorshid, Amira M.; Arsanyos, Sonya F.; Shaheen, Hesham M.; Abdel Wahab, Nahed; Amin, Sherif N.; El Rouby, Mahmoud N.; Morsy, Mona I.

2010-04-01

Photodynamic therapy (PDT) is a novel treatment modality of cancer and non-cancerous conditions that are generally characterized by an overgrowth of unwanted or abnormal cells. Irradiation of photosensitizer loaded cells or tissues leads via the photochemical reactions of excited photosensitizer molecules to the production of singlet oxygen and free radicals, which initiate cell death. Many types of compounds have been tested as photosensitizers, such as methylene blue (MB) and photopherin seemed to be very promising. This study involved 26 cases of acute lymphoblastic leukemia and 15 normal volunteers as a control group. The cell viability was measured by Light microscope and flowcytometer. Mode of cell death was detected by flowcytometer and electron microscope in selected cases. The viability percentage of normal peripheral blood mononuclear cells (PBMC) incubated with methylene blue (MB) alone or combined with photo irradiation with diode laser (as measured by light microscope) was significantly lower than that of untreated cases either measured after 1 hour (p<0.001) or 24 hours (p<0.001) post incubation. There was a significantly lower viability percentage of normal cells incubated with MB and photoirradiated with diode laser compared to normal cells treated with MB alone for either measured after 1 hour (p<0.001) or 24 hours (p<0.001) post incubation. The decrease in viability was more enhanced with increasing the incubation time. For normal cells incubated with photopherin either for 1/2 an hour or 1 hour, there was a weak cytotoxic effect compared to the effect on untreated cells. There was a significant decrease in viability percentage of cells incubated with photopherin either for 1/2 an hour or 1 hour and photoirradiated with He:Ne laser compared to normal untreated cells. The decrease in the cell viability percentage was significantly lower with the use of PDT (photopherin and He:Ne laser ) compared to either photopherin alone or He:Ne laser alone. The decrease in viability was more enhanced with increasing the incubation time. The same effects reported on normal cells were detected on leukemic cells on comparing different methods used. However a more pronounced decrease in cell viability was detected. The most efficient ways of decreasing viability of leukemic cells with much less effect on normal cells was the use of PDT of cell incubation with MB for 1 hour then photoirradiation with diode laser and PDT of cell incubation with photopherin for 1 hour then photoirradiation with He:Ne laser. Flowcytometer (FCM) was more sensitivite than the light microscope in detecting the decrease in cell viability, it also helped in determining the mode of cell death weather apoptosis, necrosis or combined apoptosis and necrosis. Apoptotic cell percentage was higher in PDT of MB and Diode laser or photopherin and He:Ne laser, treated ALL cells compared to untreated ALL cells after 1 hour but was significantly lower after 24 hours post irradiation. A significant increase in necrotic, combined necrotic and apoptotic cell percentages either measured 1 hour or 24 hours post PDT, compared to untreated ALL cells and PDT treated normal cells. Electron microscope helped in detecting early cellular apoptotic changes occurring in response to different therapeutic modalities used in this study. In conclusion, PDT proved to be an effective clinical modality in decreasing the number of leukemic cells when irradiated in vitro with appropriate laser and photosensitizer system. Both PDT systems used in this study were efficient in inducing cell death of leukemic cells compared to untreated leukemic cells. However, photopherin PDT system was more efficient in decreasing the cell viability. A significant decrease in viability percentage was detected when studying the effect of PDT on leukemic cells compared to that on normal cells. This suggests that PDT when applied clinically will selectively differentiate between leukemic cells and normal cells, offering a successful component in ALL therapy.

Tissue engineering and regenerative medicine approaches to enhance the functional response to skeletal muscle injury.

PubMed

Sicari, Brian M; Dearth, Christopher L; Badylak, Stephen F

2014-01-01

The well-recognized ability of skeletal muscle for functional and structural regeneration following injury is severely compromised in degenerative diseases and in volumetric muscle loss. Tissue engineering and regenerative medicine strategies to support muscle reconstruction have typically been cell-centric with approaches that involve the exogenous delivery of cells with myogenic potential. These strategies have been limited by poor cell viability and engraftment into host tissue. Alternative approaches have involved the use of biomaterial scaffolds as substrates or delivery vehicles for exogenous myogenic progenitor cells. Acellular biomaterial scaffolds composed of mammalian extracellular matrix (ECM) have also been used as an inductive niche to promote the recruitment and differentiation of endogenous myogenic progenitor cells. An acellular approach, which activates or utilizes endogenous cell sources, obviates the need for exogenous cell administration and provides an advantage for clinical translation. The present review examines the state of tissue engineering and regenerative medicine therapies directed at augmenting the skeletal muscle response to injury and presents the pros and cons of each with respect to clinical translation. Copyright © 2013 Wiley Periodicals, Inc.

Ultrasound-Mediated DNA Transformation in Thermophilic Gram-Positive Anaerobes

PubMed Central

Ji, Yuetong; He, Zhili; Pu, Yunting; Zhou, Jizhong; Xu, Jian

2010-01-01

Background Thermophilic, Gram-positive, anaerobic bacteria (TGPAs) are generally recalcitrant to chemical and electrotransformation due to their special cell-wall structure and the low intrinsic permeability of plasma membranes. Methodology/Principal Findings Here we established for any Gram-positive or thermophiles an ultrasound-based sonoporation as a simple, rapid, and minimally invasive method to genetically transform TGPAs. We showed that by applying a 40 kHz ultrasound frequency over a 20-second exposure, Texas red-conjugated dextran was delivered with 27% efficiency into Thermoanaerobacter sp. X514, a TGPA that can utilize both pentose and hexose for ethanol production. Experiments that delivered plasmids showed that host-cell viability and plasmid DNA integrity were not compromised. Via sonoporation, shuttle vectors pHL015 harboring a jellyfish gfp gene and pIKM2 encoding a Clostridium thermocellum β-1,4-glucanase gene were delivered into X514 with an efficiency of 6×102 transformants/µg of methylated DNA. Delivery into X514 cells was confirmed via detecting the kanamycin-resistance gene for pIKM2, while confirmation of pHL015 was detected by visualization of fluorescence signals of secondary host-cells following a plasmid-rescue experiment. Furthermore, the foreign β-1,4-glucanase gene was functionally expressed in X514, converting the host into a prototypic thermophilic consolidated bioprocessing organism that is not only ethanologenic but cellulolytic. Conclusions/Significance In this study, we developed an ultrasound-based sonoporation method in TGPAs. This new DNA-delivery method could significantly improve the throughput in developing genetic systems for TGPAs, many of which are of industrial interest yet remain difficult to manipulate genetically. PMID:20838444

Morphology based scoring of chromosomal instability and its correlation with cell viability.

PubMed

Yadav, Shubhlata; Bhatia, Alka

2017-09-01

The aim of this study was to devise the quantitative scoring system for Chromosomal instability (CIN) based on morphological indicators like MPM, NB, NPB, CS, La and MN in cancer cell line and to correlate it with cell viability and death. Human hepatocellular carcinoma (HepG2) cells were treated with drugs like Diethylstilbestrol 0-100μM, Griseofulvin 0-40μg/ml, Vincristine sulphate 0-25μg/ml, Mitomycin C 0-600ng/ml, Bleomycin 0-10μg/ml, Doxorubicin 0-30μg/ml for 24h. Following this, the CIN was assessed by counting the morphological indicators like Micronuclei (MN), Nuclear Buds (NB), Nucleoplasmic bridges, Laggards, Multipolar mitosis and chromatin strings/1000 cells in Giemsa stained smears by light microscopy and by determining the percentage of aneuploid cells by flow cytometry. The cell viability was assessed by MTT assay and percentage of apoptotic cells was determined by flow cytometry. The MN and NB were most frequently seen indicators and main determinants of morphological CIN. However, the morphological CIN score did not show any correlation with cell viability and apoptosis. Aneuploidy however was found to correlate positively with cell viability and NB score in our study (P-value <0.05). The study for the 1st time attempted to develop a scoring system for CIN based on morphological parameters. However, a no correlation was observed between the later and cell viability or apoptosis. More robust techniques to quantify CIN may perhaps be more helpful in exploring the true link between CIN and cell viability in future. Copyright © 2017 Elsevier GmbH. All rights reserved.

Soy milk as a storage medium to preserve human fibroblast cell viability: an in vitro study.

PubMed

Moura, Camilla Christian Gomes; Soares, Priscilla Barbosa Ferreira; Reis, Manuella Verdinelli de Paula; Fernandes Neto, Alfredo Júlio; Soares, Carlos José

2012-01-01

Soy milk (SM) is widely consumed worldwide as a substitute for cow milk. It is a source of vitamins, carbohydrates and sugars, but its capacity to preserve cell viability has not been evaluated. The purpose of the present study was to investigate the efficacy of SM to maintain the viability of human fibroblasts at short periods compared with different cow milks. Human mouth fibroblasts were cultured and stored in the following media at room temperature: 10% Dulbecco's Modified Eagle Medium (DMEM) (positive control group); long shelf-life ultra-high temperature whole cow milk (WM); long shelf-life ultra-high temperature skim cow milk (SKM); powdered cow milk (PM); and soy milk (SM). After 5, 15, 30 and 45 min, cell viability was analyzed using the MTT assay. Data were analyzed statistically by the Kruskal-Wallis test with post-analysis using the Dunn's method (α=0.05). SKM showed the lowest capacity to maintain cell viability in all analyzed times (p<0.05). At 30 and 45 min, the absorbance levels in control group (DMEM) and SM were significantly higher than in SKM (p<0.05). Cell viability decreased along the time (5-45 min). The results indicate that SM can be used as a more adequate storage medium for avulsed teeth. SKM was not as effective in preserving cell viability as the cell culture medium and SM.

Effect of berberine on the viability of adipose tissue-derived mesenchymal stem cells in nutrients deficient condition.

PubMed

Ghorbani, Ahmad; Baradaran Rahimi, Vafa; Sadeghnia, Hamid Reza; Hosseini, Azar

2018-03-01

This study was designed to examine whether berberine protects rat adipose tissue-derived stem cells (ASCs) against glucose and serum deprivation (GSD)-induced cell death. ASCs were cultured for 24 h in GSD condition in the presence of berberine and then cell viability, apoptosis and generation of reactive oxygen species (ROS) were evaluated. The GSD condition significantly decreased ASCs viability and increased ROS generation and apoptosis. Incubation with 0.75-3 μM berberine partially increased cell viability and decreased ROS generation and apoptosis in GSD condition. In conclusion, berberine partially protects ASCs in nutrients deficient condition and may help ASCs to preserve their survival during cell therapy of ischemia.

Gain of glucose-independent growth upon metastasis of breast cancer cells to the brain

PubMed Central

Chen, Jinyu; Lee, Ho-Jeong; Wu, Xuefeng; Huo, Lei; Kim, Sun-Jin; Xu, Lei; Wang, Yan; He, Junqing; Bollu, Lakshmi Reddy; Gao, Guang; Su, Fei; Briggs, James; Liu, Xiaojing; Melman, Tamar; Asara, John M.; Fidler, Isaiah J.; Cantley, Lewis C.; Locasale, Jason W.; Weihua, Zhang

2014-01-01

Breast cancer brain metastasis is resistant to therapy and a particularly poor prognostic feature in patient survival. Altered metabolism is a common feature of cancer cells but little is known as to what metabolic changes benefit breast cancer brain metastases. We found that brain-metastatic breast cancer cells evolved the ability to survive and proliferate independent of glucose due to enhanced gluconeogenesis and oxidations of glutamine and branched chain amino acids, which together sustain the non-oxidative pentose pathway for purine synthesis. Silencing expression of fructose-1,6-bisphosphatases (FBPs) in brain metastatic cells reduced their viability and improved the survival of metastasis-bearing immunocompetent hosts. Clinically, we showed that brain metastases from human breast cancer patients expressed higher levels of FBP and glycogen than the corresponding primary tumors. Together, our findings identify a critical metabolic condition required to sustain brain metastasis, and suggest that targeting gluconeogenesis may help eradicate this deadly feature in advanced breast cancer patients. PMID:25511375

Gain of glucose-independent growth upon metastasis of breast cancer cells to the brain.

PubMed

Chen, Jinyu; Lee, Ho-Jeong; Wu, Xuefeng; Huo, Lei; Kim, Sun-Jin; Xu, Lei; Wang, Yan; He, Junqing; Bollu, Lakshmi R; Gao, Guang; Su, Fei; Briggs, James; Liu, Xiaojing; Melman, Tamar; Asara, John M; Fidler, Isaiah J; Cantley, Lewis C; Locasale, Jason W; Weihua, Zhang

2015-02-01

Breast cancer brain metastasis is resistant to therapy and a particularly poor prognostic feature in patient survival. Altered metabolism is a common feature of cancer cells, but little is known as to what metabolic changes benefit breast cancer brain metastases. We found that brain metastatic breast cancer cells evolved the ability to survive and proliferate independent of glucose due to enhanced gluconeogenesis and oxidations of glutamine and branched chain amino acids, which together sustain the nonoxidative pentose pathway for purine synthesis. Silencing expression of fructose-1,6-bisphosphatases (FBP) in brain metastatic cells reduced their viability and improved the survival of metastasis-bearing immunocompetent hosts. Clinically, we showed that brain metastases from human breast cancer patients expressed higher levels of FBP and glycogen than the corresponding primary tumors. Together, our findings identify a critical metabolic condition required to sustain brain metastasis and suggest that targeting gluconeogenesis may help eradicate this deadly feature in advanced breast cancer patients. ©2014 American Association for Cancer Research.

The Pore-Forming Protein Gasdermin D Regulates Interleukin-1 Secretion from Living Macrophages.

PubMed

Evavold, Charles L; Ruan, Jianbin; Tan, Yunhao; Xia, Shiyu; Wu, Hao; Kagan, Jonathan C

2018-01-16

The interleukin-1 (IL-1) family cytokines are cytosolic proteins that exhibit inflammatory activity upon release into the extracellular space. These factors are released following various cell death processes, with pyroptosis being a common mechanism. Recently, it was recognized that phagocytes can achieve a state of hyperactivation, which is defined by their ability to secrete IL-1 while retaining viability, yet it is unclear how IL-1 can be secreted from living cells. Herein, we report that the pyroptosis regulator gasdermin D (GSDMD) was necessary for IL-1β secretion from living macrophages that have been exposed to inflammasome activators, such as bacteria and their products or host-derived oxidized lipids. Cell- and liposome-based assays demonstrated that GSDMD pores were required for IL-1β transport across an intact lipid bilayer. These findings identify a non-pyroptotic function for GSDMD, and raise the possibility that GSDMD pores represent conduits for the secretion of cytosolic cytokines under conditions of cell hyperactivation. Copyright © 2017 Elsevier Inc. All rights reserved.

Potential of coconut water and soy milk for use as storage media to preserve the viability of periodontal ligament cells: an in vitro study.

PubMed

Moura, Camilla Cristhian Gomes; Soares, Priscilla Barbosa Ferreira; de Paula Reis, Manuella Verdinelli; Fernandes Neto, Alfredo Júlio; Zanetta Barbosa, Darceny; Soares, Carlos José

2014-02-01

There is no consensus regarding the ability of coconut water and soy milk to maintain long-term cell viability. This study investigated the ability of pH-adjusted coconut water and soy milk to maintain the viability of periodontal ligament cells over a short and a longer period and compared these abilities with those of other solutions. Dog premolar teeth were extracted, dried for 30 min, and stored in the following media for 50 min or 24 h: long shelf-life whole milk (SWM), long shelf-life skim milk (SSM), Hank's Balanced Salt Solution (HBSS), soy milk (SM), and pH-adjusted coconut water (CW). The positive and two negative control groups corresponded to 0-min, 30-min (short-term), and 24-h (long-term) dry times, respectively. Cell viability was analyzed by trypan blue exclusion. Data were statistically analyzed using the Kruskal-Wallis test with post-analysis using the Dunn method. In the short-term experiment, the SSM resulted in significantly lower cell viability than SM and CW. At 24 h, SM and CW resulted in higher viability than HBSS and SSM and in comparable performance with the positive control group. Cell viability decreased over time, except in SM and CW. Soy milk and pH-adjusted coconut water showed promising results as storage solutions for avulsed teeth, preserving the viability for up to 24 h. © 2013 John Wiley & Sons A/S.

Role of cytoskeletal mechanics and cell membrane fluidity in the intracellular delivery of molecules mediated by laser-activated carbon nanoparticles.

PubMed

Holguin, Stefany Y; Anderson, Caleb F; Thadhani, Naresh N; Prausnitz, Mark R

2017-10-01

Exposure of cells and nanoparticles to near-infrared nanosecond pulsed laser light can lead to efficient intracellular delivery of molecules while maintaining high cell viability by a photoacoustic phenomenon known as transient nanoparticle energy transduction (TNET). Here, we examined the influence of cytoskeletal mechanics and plasma membrane fluidity on intracellular uptake of molecules and loss of cell viability due to TNET. We found that destabilization of actin filaments using latrunculin A led to greater uptake of molecules and less viability loss caused by TNET. Stabilization of actin filaments using jasplakinolide had no significant effect on uptake or viability loss caused by TNET. To study the role of plasma membrane fluidity, we increased fluidity by depletion of membrane cholesterol using methyl-β-cyclodextrin and decreased fluidity by enrichment of the membrane with cholesterol using water-soluble cholesterol. Neither of these membrane fluidity changes significantly altered cellular uptake or viability loss caused by TNET. We conclude that weakening mechanical integrity of the cytoskeleton can increase intracellular uptake and decrease loss of cell viability, while plasma membrane fluidity does not appear to play a significant role in uptake or viability loss caused by TNET. The positive effects of cytoskeletal weakening may be due to an enhanced ability of the cell to recover from the effects of TNET and maintain viability. Biotechnol. Bioeng. 2017;114: 2390-2399. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Development of an optimized tetracycline-inducible expression system to increase the accumulation of interleukin-10 in tobacco BY-2 suspension cells.

PubMed

Bortesi, Luisa; Rademacher, Thomas; Schiermeyer, Andreas; Schuster, Flora; Pezzotti, Mario; Schillberg, Stefan

2012-07-11

Plant cell suspension cultures can be used for the production of valuable pharmaceutical and industrial proteins. When the recombinant protein is secreted into the culture medium, restricting expression to a defined growth phase can improve both the quality and quantity of the recovered product by minimizing proteolytic activity. Temporal restriction is also useful for recombinant proteins whose constitutive expression affects cell growth and viability, such as viral interleukin-10 (vIL-10). We have developed a novel, tetracycline-inducible system suitable for tobacco BY-2 suspension cells which increases the yields of vIL-10. The new system is based on a binary vector that is easier to handle than conventional vectors, contains an enhanced inducible promoter and 5'-UTR to improve yields, and incorporates a constitutively-expressed visible marker gene to allow the rapid and straightforward selection of the most promising transformed clones. Stable transformation of BY-2 cells with this vector, without extensive optimization of the induction conditions, led to a 3.5 fold increase in vIL-10 levels compared to constitutive expression in the same host. We have developed an effective and straightforward molecular farming platform technology that improves both the quality and the quantity of recombinant proteins produced in plant cells, particularly those whose constitutive expression has a negative impact on plant growth and development. Although we tested the platform using vIL-10 produced in BY-2 cells, it can be applied to other host/product combinations and is also useful for basic research requiring strictly controlled transgene expression.

A bilaminated decellularized scaffold for islet transplantation: Structure, properties and functions in diabetic mice.

PubMed

Wang, Xi; Wang, Kai; Zhang, Wei; Qiang, Ming; Luo, Ying

2017-09-01

Ectopic transplantation of islets provides a beta cell-replacement approach that may allow the recovery of physiological regulation of the blood sugar level in patients with Type I diabetes (T1D). In development of new extrahepatic islet transplantation protocols in support of the islet engraftment, it is pivotal to develop scaffold materials with multifaceted functions to provide beneficial microenvironment, mediate host response in favor of vascularization/islet integration and maintain long-term islet function at the transplantation site. In this study, a new composite bilaminar decellularized scaffold (CDS) was fabricated with differential structural, degradation and mechanical properties by the combination of a fast-degrading porous collagen matrix and a mechanically supportive porcine pericardium. When investigated in the epididymal fat pad in syngeneic mouse models, it was shown that CDS could serve as superior scaffolds to promote islet adhesion and viability, and islet-CDS constructs also allowed rapid reversal of the hyperglycemic condition in the host. The engraftment and effects of islets were achieved at low islet numbers, accompanied by minimal adverse tissue reactions and optimal islet integration with the surrounding fat tissue. The bioactive surface, mechanical/chemical durability and biocompatibility of the CDS may all have played important roles in facilitating the engraftment of islets. Our study provided new insights into scaffold's function in the interplay of cells, materials and host tissue and the extracellular matrix-based scaffolds have potential for clinical translation in the beta cell-replacement therapy to treat T1D. Copyright © 2017 Elsevier Ltd. All rights reserved.

Hydrolytically Degradable Poly(Ethylene Glycol) Hydrogel Scaffolds as a Cell Delivery Vehicle: Characterization of PC12 Cell Response

PubMed Central

Zustiak, Silviya P.; Pubill, Stephanie; Ribeiro, Andreia; Leach, Jennie B.

2013-01-01

The central nervous system (CNS) has a low intrinsic potential for regeneration following injury and disease, yet neural stem/progenitor cell (NPC) transplants show promise to provide a dynamic therapeutic in this complex tissue environment. Moreover, biomaterial scaffolds may improve the success of NPC-based therapeutics by promoting cell viability and guiding cell response. We hypothesized that a hydrogel scaffold could provide a temporary neurogenic environment that supports cell survival during encapsulation, and degrades completely in a temporally controlled manner to allow progression of dynamic cellular processes such as neurite extension. We utilized PC12 cells as a model cell line with an inducible neuronal phenotype to define key properties of hydrolytically-degradable poly(ethylene glycol) hydrogel scaffolds that impact cell viability and differentiation following release from the degraded hydrogel. Adhesive peptide ligands (RGDS, IKVAV or YIGSR), were required to maintain cell viability during encapsulation; as compared to YIGSR, the RGDS and IKVAV ligands were associated with a higher percentage of PC12 cells that differentiated to the neuronal phenotype following release from the hydrogel. Moreover, among the hydrogel properties examined (e.g., ligand type, concentration), total polymer density within the hydrogel had the most prominent effect on cell viability, with densities above 15% w/v leading to decreased cell viability likely due to a higher shear modulus. Thus, by identifying key properties of degradable hydrogels that affect cell viability and differentiation following release from the hydrogel, we lay the foundation for application of this system towards future applications of the scaffold as a neural cell delivery vehicle. PMID:24474590

Atorvastatin Promotes Cytotoxicity and Reduces Migration and Proliferation of Human A172 Glioma Cells.

PubMed

Oliveira, Karen A; Dal-Cim, Tharine; Lopes, Flávia G; Ludka, Fabiana K; Nedel, Cláudia B; Tasca, Carla I

2018-02-01

Malignant gliomas have resistance mechanisms to chemotherapy that enable tumor invasiveness and aggressiveness. Alternative therapies in cancer treatment, as statins, have been suggested to decrease proliferation, inhibit cell migration, and induce cell death. The aim of this study was to evaluate the effect of atorvastatin (ATOR) on cell viability, migration, proliferation, apoptosis, and autophagy in A172 human glioma cells. Temozolomide (TMZ), a chemotherapic used to glioma treatment, was tested as a comparison to cytotoxic effects on gliomas. Cell viability was also assessed in primary culture of cortical astrocytes. ATOR treatment (0.1 to 20 μM) did not alter astrocytic viability. However, in glioma cells, ATOR showed cytotoxic effect at 10 and 20 μM concentrations. TMZ (500 μM) reduced cell viability similarly to ATOR, and drug association did not show additive effect on cell viability. ATOR, TMZ, and their association decreased cell migration. ATOR also decreased glioma cell proliferation. ATOR increased apoptosis, and TMZ association showed a potentiation effect, enhancing it. ATOR and TMZ treatment increased acidic vesicular organelle (AVO) presence in A172 cells, an indicative of autophagy. ATOR effect of reducing A172 cell viability did not alter glutamate transport and glutamine synthetase activity, but it was partially prevented through antagonism of ionotropic and metabotropic glutamate receptors. Our data shows a cytotoxic effect of ATOR on glioma cells, whereas no toxicity was observed to astrocytes. ATOR showed similar cytotoxic effect as TMZ to glioma cells, and it may be a safer drug, regarding side effect induction, than chemotherapic agents.

MC3T3-E1 Cells on Titanium Surfaces with Nanometer Smoothness and Fibronectin Immobilization

PubMed Central

Hayakawa, Tohru; Yoshida, Eiji; Yoshimura, Yoshitaka; Uo, Motohiro; Yoshinari, Masao

2012-01-01

The present study was aimed to evaluate the viability and total protein contents of osteoblast-like cells on the titanium surface with different surface mechanical treatment, namely, nanometer smoothing (Ra: approximately 2.0 nm) and sandblasting (Ra: approximately 1.0 μm), and biochemical treatment, namely, with or without fibronectin immobilization. Fibronectin could be easily immobilized by tresyl chloride-activation technique. MC3T3-E1 cells were seeded on the different titanium surfaces. Cell viability was determined by MTT assay. At 1 day of cell culture, there were no significant differences in cell viability among four different titanium surfaces. At 11 days, sandblasted titanium surface with fibronectin immobilization showed the significantly highest cell viability than other titanium surface. No significant differences existed for total protein contents among four different titanium surfaces at 11 days of cell culture. Scanning electron microscopy observation revealed that smoothness of titanium surface produced more spread cell morphologies, but that fibronectin immobilization did not cause any changes of the morphologies of attached cells. Fibronectin immobilization provided greater amount of the number of attached cells and better arrangement of attached cells. In conclusion, the combination of sandblasting and fibronectin immobilization enhanced the cell viability and fibronectin immobilization providing better arrangements of attached cells. PMID:22675359

Cathelicidins Inhibit Escherichia coli–Induced TLR2 and TLR4 Activation in a Viability-Dependent Manner

PubMed Central

Coorens, Maarten; Schneider, Viktoria A. F.; Meijerink, Marjolein; Wells, Jerry M.; Scheenstra, Maaike R.

2017-01-01

Activation of the immune system needs to be tightly regulated to provide protection against infections and, at the same time, to prevent excessive inflammation to limit collateral damage to the host. This tight regulation includes regulating the activation of TLRs, which are key players in the recognition of invading microbes. A group of short cationic antimicrobial peptides, called cathelicidins, have previously been shown to modulate TLR activation by synthetic or purified TLR ligands and may play an important role in the regulation of inflammation during infections. However, little is known about how these cathelicidins affect TLR activation in the context of complete and viable bacteria. In this article, we show that chicken cathelicidin-2 kills Escherichia coli in an immunogenically silent fashion. Our results show that chicken cathelicidin-2 kills E. coli by permeabilizing the bacterial inner membrane and subsequently binds the outer membrane–derived lipoproteins and LPS to inhibit TLR2 and TLR4 activation, respectively. In addition, other cathelicidins, including human, mouse, pig, and dog cathelicidins, which lack antimicrobial activity under cell culture conditions, only inhibit macrophage activation by nonviable E. coli. In total, this study shows that cathelicidins do not affect immune activation by viable bacteria and only inhibit inflammation when bacterial viability is lost. Therefore, cathelicidins provide a novel mechanism by which the immune system can discriminate between viable and nonviable Gram-negative bacteria to tune the immune response, thereby limiting collateral damage to the host and the risk for sepsis. PMID:28710255

Cytotoxic outcomes of orthodontic bands with and without silver solder in different cell lineages.

PubMed

Jacoby, Letícia Spinelli; Rodrigues Junior, Valnês da Silva; Campos, Maria Martha; Macedo de Menezes, Luciane

2017-05-01

The safety of orthodontic materials is a matter of high interest. In this study, we aimed to assess the in-vitro cytotoxicity of orthodontic band extracts, with and without silver solder, by comparing the viability outcomes of the HaCat keratinocytes, the fibroblastic cell lineages HGF and MRC-5, and the kidney epithelial Vero cells. Sterilized orthodontic bands with and without silver solder joints were added to culture media (6 cm 2 /mL) and incubated for 24 hours at 37°C under continuous agitation. Subsequently, the cell cultures were exposed to the obtained extracts for 24 hours, and an assay was performed to evaluate the cell viability. Copper strip extracts were used as positive control devices. The extracts from orthodontic bands with silver solder joints significantly reduced the viability of the HaCat, MRC-5, and Vero cell lines, whereas the viability of HGF was not altered by this material. Conversely, the extracts of orthodontic bands without silver solder did not significantly modify the viability index of all evaluated cell lines. Except for HGF fibroblasts, all tested cell lines showed decreased viability percentages after exposure to extracts of orthodontic bands containing silver solder joints. These data show the relevance of testing the toxicity of orthodontic devices in different cell lines. Copyright © 2017 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

The ATP/DNA Ratio Is a Better Indicator of Islet Cell Viability Than the ADP/ATP Ratio

PubMed Central

Suszynski, T.M.; Wildey, G.M.; Falde, E.J.; Cline, G.W.; Maynard, K. Stewart; Ko, N.; Sotiris, J.; Naji, A.; Hering, B.J.; Papas, K.K.

2009-01-01

Real-time, accurate assessment of islet viability is critical for avoiding transplantation of nontherapeutic preparations. Measurements of the intracellular ADP/ATP ratio have been recently proposed as useful prospective estimates of islet cell viability and potency. However, dead cells may be rapidly depleted of both ATP and ADP, which would render the ratio incapable of accounting for dead cells. Since the DNA of dead cells is expected to remain stable over prolonged periods of time (days), we hypothesized that use of the ATP/DNA ratio would take into account dead cells and may be a better indicator of islet cell viability than the ADP/ATP ratio. We tested this hypothesis using mixtures of healthy and lethally heat-treated (HT) rat insulinoma cells and human islets. Measurements of ATP/DNA and ADP/ATP from the known mixtures of healthy and HT cells and islets were used to evaluate how well these parameters correlated with viability. The results indicated that ATP and ADP were rapidly (within 1 hour) depleted in HT cells. The fraction of HT cells in a mixture correlated linearly with the ATP/DNA ratio, whereas the ADP/ADP ratio was highly scattered, remaining effectively unchanged. Despite similar limitations in both ADP/ADP and ATP/DNA ratios, in that ATP levels may fluctuate significantly and reversibly with metabolic stress, the results indicated that ATP/DNA was a better measure of islet viability than the ADP/ATP ratio. PMID:18374063

A high-throughput AO/PI-based cell concentration and viability detection method using the Celigo image cytometry.

PubMed

Chan, Leo Li-Ying; Smith, Tim; Kumph, Kendra A; Kuksin, Dmitry; Kessel, Sarah; Déry, Olivier; Cribbes, Scott; Lai, Ning; Qiu, Jean

2016-10-01

To ensure cell-based assays are performed properly, both cell concentration and viability have to be determined so that the data can be normalized to generate meaningful and comparable results. Cell-based assays performed in immuno-oncology, toxicology, or bioprocessing research often require measuring of multiple samples and conditions, thus the current automated cell counter that uses single disposable counting slides is not practical for high-throughput screening assays. In the recent years, a plate-based image cytometry system has been developed for high-throughput biomolecular screening assays. In this work, we demonstrate a high-throughput AO/PI-based cell concentration and viability method using the Celigo image cytometer. First, we validate the method by comparing directly to Cellometer automated cell counter. Next, cell concentration dynamic range, viability dynamic range, and consistency are determined. The high-throughput AO/PI method described here allows for 96-well to 384-well plate samples to be analyzed in less than 7 min, which greatly reduces the time required for the single sample-based automated cell counter. In addition, this method can improve the efficiency for high-throughput screening assays, where multiple cell counts and viability measurements are needed prior to performing assays such as flow cytometry, ELISA, or simply plating cells for cell culture.

Comparative evaluation of the isolation and quantification of stem cells derived from dental pulp and periodontal ligament of a permanent tooth and to assess their viability and proliferation on a platelet-rich fibrin scaffold.

PubMed

Khurana, Rohit; Kudva, Praveen Bhasker; Husain, Syed Yawer

2017-01-01

The present study aims to comparatively evaluate the isolation and quantification of stem cells derived from dental pulp and periodontal ligament of a permanent tooth and to assess their viability and proliferation on a platelet-rich fibrin (PRF) scaffold. A total of 15 systemically healthy individuals between the age group of 15-25 years requiring third molar or orthodontic premolar extractions. Teeth were extracted atraumatically and transported to the laboratory. Stem cells were isolated from dental pulp and periodontal ligament. After attaining more than 90% confluency by the 7 th day, these cells were tested for their viability and characterization. Stem cells were also incubated with PRF and viability was assessed on the 7 th day. The mean number of cell for dental pulp stem cells (DPSCs) and periodontal ligament stem cell (PDLSC) was statistically insignificant ( P > 0.05). The mean live cell viability was compared between DPSC (98.07%) and PDLSC (98%). Both DPSC and PDLSC showed a high percentage of expression of CD73 markers, 30.40% and 29.80%, respectively. However, DPSCs and PDLSCs lacked expression of CD34 expressing only 3.47% and 3.53%, respectively. PRF membrane as a scaffold exhibited no cytotoxic effects on DPCS's or PDLSC's. The cell viability of cells cultured with PRF was statistically insignificant ( P > 0.05) when compared to the cells cultured with culture media. The study thus indicates that dental pulp and periodontal ligament are both rich sources of mesenchymal stem cells and can be successfully used for obtaining stem cells. PRF exhibits no cytotoxic effects on the cells and can be used in conjunction with dental stem cells.

The analysis of viability for mammalian cells treated at different temperatures and its application in cell shipment.

PubMed

Wang, Juan; Wei, Yun; Zhao, Shasha; Zhou, Ying; He, Wei; Zhang, Yang; Deng, Wensheng

2017-01-01

Mammalian cells are very important experimental materials and widely used in biological and medical research fields. It is often required that mammalian cells are transported from one laboratory to another to meet with various researches. Conventional methods for cell shipment are laborious and costive despite of maintaining high viability. In this study we aimed to develop a simple and low-cost method for cell shipment by investigating the viabilities of different cell lines treated at different temperatures. We show that the viability of mammalian cells incubated at 1°C or 5°C significantly reduced when compared with that at 16°C or 22°C. Colony formation assays revealed that preservation of mammalian cells at 1°C or 5°C led to a poorer recovery than that at 16°C or 22°C. The data from proliferation and apoptotic assays confirmed that M2 cells could continue to proliferate at 16°C or 22°C, but massive death was caused by apoptosis at 1°C or 5°C. The morphology of mammalian cells treated under hypothermia showed little difference from that of the untreated cells. Quantitative RT-PCR and alkaline phosphatase staining confirmed that hypothermic treatment did not change the identity of mouse embryonic stem cells. A case study showed that mammalian cells directly suspended in culture medium were able to be shipped for long distance and maintained a high level of viability and recovery. Our findings not only broaden the understanding to the effect of hypothermia on the viability of mammalian cells, but also provide an alternative approach for cell shipment.

Exacerbation of innate immune response in mouse primary cultured sertoli cells caused by nanoparticulate TiO2 involves the TAM/TLR3 signal pathway.

PubMed

Wu, Nan; Hong, Fashui; Zhou, Yingjun; Wang, Yajing

2017-01-01

Sertoli cells provide appropriate mitogens, differentiation factors and sources of energy for developing germ cells throughout the lifetime of males, and protect these germ cells from harmful agents and from the host's own immune system. Therefore, reductions in the rate and quality of spermatogenesis caused by nanoparticulate titanium dioxide (nano-TiO 2 ) may be closely involved in the immunoregulation of Sertoli cells. However, the underlying mechanism of this response is still unclear. To address this issue, we used mouse primary cultured Sertoli cells to examine the toxic effects of nano-TiO 2 via alterations in morphology, cell viability, and activation of the TAM/TLR3 signal pathway. The results demonstrated that nano-TiO 2 could cross the cytomembrane into the cytoplasm or nucleus, decrease Sertoli cell viability, damage morphology (such as elongated fusiform, cellular and nuclear shrinkage) and induce the expression of various immune mediators and inflammatory cytokines, including TLR3(+0.31-fold to +0.81-fold), IL-lβ(+0.33-fold to +5.0-fold), NF-κB(+0.22-fold to +3.65-fold), IL-6(+0.47-fold to +3.53-fold), TNF-α(+0.14-fold to +2.44-fold), IFN-α(+0.17-fold to +2.27-fold), and IFN-β(+0.09-fold to +2.29-fold), and suppress the expression of Tyro3(-9.33% to -61.93%), Axl(-19.03% to -60.67%), Mer(-8.04% to -59.16%), and IκB(-34.35% to -86.59%) in primary cultured Sertoli cells. These results suggest that testicular innate immune responses to pathogens caused by nano-TiO 2 may be involved in the regulatory mechanisms of TAM/TLR3 signaling in testicular Sertoli cells. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 198-208, 2017. © 2016 Wiley Periodicals, Inc.

Photochemical bonding of epithelial cell-seeded collagen lattice to rat muscle layer for esophageal tissue engineering: a pilot study

NASA Astrophysics Data System (ADS)

Chan, Barbara P.; Sato, M.; Vacanti, Joseph P.; Kochevar, Irene E.; Redmond, Robert W.

2005-04-01

Bilayered tube structures consist of epithelial cell-seeded collagen lattice and muscle layer have been fabricated for esophageal tissue engineering. Good adhesion between layers in order to facilitate cell infiltration and neovascularization in the collagen lattice is required. Previous efforts include using other bioglues such as fibrin glue and silicone tube as the physical support. However, the former is subjected to chances of transmitting blood-born infectious disease and is time consuming while the latter requires a second surgical procedure. The current project aimed to bond the cell-seeded collagen lattice to muscle layer using photochemical bonding, which has previously been demonstrated a rapid and non-thermal procedure in bonding collagenous tissues. Rat esophageal epithelial cells were seeded on collagen lattice and together with the latissimus dorsi muscle layer, were exposed to a photosensitizer rose Bengal at the bonding surface. An argon laser was used to irradiate the approximated layers. Bonding strength was measured during the peeling test of the collagen layer from the muscle layer. Post-bonding cell viability was assessed using a modified NADH-diaphorase microassay. A pilot in vivo study was conducted by directly bonding the cell-seeded collagen layer onto the muscle flap in rats and the structures were characterized histologically. Photochemical bonding was found to significantly increase the adherence at the bonding interface without compromising the cell viability. This indicates the feasibility of using the technique to fabricate multi-layered structures in the presence of living cells. The pilot animal study demonstrated integration of the collagen lattice with the muscle layer at the bonding interface although the subsequent surgical manipulation disturbed the integration at some region. This means that an additional procedure removing the tube could be avoided if the approximation and thus the bonding are optimized. Cell infiltration and neovascularization were also evident demonstrating that direct bonding of engineered tissue structures in particular those with low processability such as collagen lattice to the host tissue is feasible.

The combined influence of sub-optimal temperature and salinity on the in vitro viability of Perkinsus marinus, a protistan parasite of the eastern oyster Crassostrea virginica

USGS Publications Warehouse

La Peyre, M.K.; Casas, S.M.; Gayle, W.; La Peyre, Jerome F.

2010-01-01

Perkinsus marinus is a major cause of mortality in eastern oysters along the Gulf of Mexico and Atlantic coasts. It is also well documented that temperature and salinity are the primary environmental factors affecting P. marinus viability and proliferation. However, little is known about the effects of combined sub-optimal temperatures and salinities on P. marinus viability. This in vitro study examined those effects by acclimating P. marinus at three salinities (7, 15, 25. ppt) to 10 ??C to represent the lowest temperatures generally reached in the Gulf of Mexico, and to 2 ??C to represent the lowest temperatures reached along the mid-Atlantic coasts and by measuring changes in cell viability and density on days 1, 30, 60 and 90 following acclimation. Cell viability and density were also measured in 7. ppt cultures acclimated to each temperature and then transferred to 3.5. ppt. The largest decreases in cell viability occurred only with combined low temperature and salinity, indicating that there is clearly a synergistic effect. The largest decreases in cell viability occurred only with both low temperature and salinity after 30. days (3.5. ppt, 2 ??C: 0% viability), 60. days (3.5. ppt, 10 ??C: 0% viability) and 90. days (7. ppt, 2 ??C: 0.6 ?? 0.7%; 7. ppt, 10 ??C: 0.2 ?? 0.2%). ?? 2010 .

The effects of cetrorelix and triptorelin on the viability and steroidogenesis of cultured human granulosa luteinized cells.

PubMed

Metallinou, Chryssa; Köster, Frank; Diedrich, Klaus; Nikolettos, Nikos; Asimakopoulos, Byron

2012-01-01

We investigated the effects of the gonadotropin-releasing hormone (GnRH) agonist triptorelin as well the GnRH antagonist cetrorelix those of on the viability and steroidogenesis in human granulosa luteinized (hGL) cell cultures. The hGL cells were obtained from 34 women undergoing ovarian stimulation for IVF treatment. The cells were cultured for 48 h with or without 1 nM or 3 nM of cetrorelix or triptorelin in serum-free media. The cell viability was evaluated by the MTT [3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide] assay. The concentrations of estradiol and progesterone in culture supernatants were measured by ELISA. Treatment with triptorelin slightly increased cell viability, whereas treatment with 3 nM cetrorelix led to a significant decrease. Estradiol concentrations were reduced with 3 nM triptorelin. Cultures treated with high-dose of either cetrorelix or triptorelin tended to secrete less progesterone than controls. Cetrorelix significantly reduces the viability of hGL cells. Triptorelin and cetrorelix may have minor effects on steroidogenesis. These results suggest that GnRH analogues may influence ovarian functions.

Biotechnological uses of desiccation-tolerant microorganisms for the rhizoremediation of soils subjected to seasonal drought.

PubMed

Vilchez, S; Manzanera, Maximino

2011-09-01

Plant growth-promoting rhizobacteria (PGPR) increase the viability and health of host plants when they colonize roots and engage in associative symbiosis (Bashan et al. 2004). In return, PGPR viability is increased by host plant roots by the provision of nutrients and a more protective environment (Richardson et al. in Plant Soil 321:305-339, 2009). The PGPR have great potential in agriculture since the combination of certain microorganisms and plants can increase crop production and increase protection against frost, salinity, drought and other environmental stresses such as the presence of xenobiotic pollutants. But there is a great challenge in combining plants and microorganisms without compromising the viability of either microorganisms or seeds. In this paper, we review how anhydrobiotic engineering can be used for the formulation of biotechnological tools that guarantee the supply of both plants and microorganisms in the dry state. We also describe the application of this technology for the selection of desiccation-tolerant PGPR for polycyclic aromatic hydrocarbons bioremediation, in soils subjected to seasonal drought, by the rhizoremediation process.

Avenanthramide-C reduces the viability of MDA-MB-231 breast cancer cells through an apoptotic mechanism.

PubMed

Hastings, Jordan; Kenealey, Jason

2017-01-01

Avenanthramides (AVN) are a relatively unstudied family of phytochemicals that could be novel chemotherapeutics. These compounds, found in oats, are non-toxic to healthy cells and have been shown to reduce viability of human colon and liver cancers in vitro. However, these studies do not elucidate a molecular mechanism for individual AVN. In this study we aim to see the effects of AVN on MDA-MB-231 breast cancer cells. An MTT assay was used to determine cell viability. Staining and analysis with a flow cytometer was used to identify cell cycle progression and apoptosis. FloJo software was used to analyze the cytometric data. In all experiments, statistical significance was determined by a two-tailed t test. This study demonstrates that AVN-A, B, and C individually reduce viability in the MDA-MB-231 breast cancer cell line. AVN-C has the most potent decrease in tumor cell viability, decreasing viable cells to below 25% at 400 µM when compared to control after 96 h. We demonstrate that treatment with AVN-C causes DNA fragmentation and accumulation of over 90% of cells into a sub G 1 cell cycle population. Further, we conclude that AVN-C treated cells activate apoptosis because 97% of treated cells stain positive for annexin V while 91% have caspase-3/7 activity, a late marker of apoptosis. Breast cancer cells treated with AVN-C have a decrease in cell viability, an increase in the sub G 1 population, and stain positive for both annexin V and caspase activity, indicating that AVN-C induces apoptosis in breast cancer cells. These compounds may be able to act as chemotherapeutics as demonstrated through future in vivo studies.

Differential Effects of Bevacizumab, Ranibizumab, and Aflibercept on the Viability and Wound Healing of Corneal Epithelial Cells.

PubMed

Kang, Seungbum; Choi, Hyunsu; Rho, Chang Rae

2016-12-01

This study compared the effects of 3 antivascular endothelial growth factor (VEGF) agents (bevacizumab, ranibizumab, and aflibercept) on corneal epithelial cell viability and wound healing using human corneal epithelial cells (HCECs). To determine the cytotoxic effects of anti-VEGF agents on HCECs, HCEC viability was determined at various concentrations of these agents. An in vitro migration assay was used to investigate the migration of HCECs treated with 3 anti-VEGF agents. The protein level of extracellular signal-regulated kinase was used to evaluate the effect of anti-VEGF treatment on cell proliferation. The protein levels of p38 mitogen-activated protein kinase (MAPK) were analyzed by Western blotting to investigate cell migration. After 24 or 48 h of exposure, aflibercept treatment showed no apparent effect on cell viability; however, bevacizumab and ranibizumab treatment decreased cell viability at high concentrations (1 and 2 mg/mL). A migration assay showed that HCEC migration was different among the 3 anti-VEGF treatment groups. Bevacizumab significantly delayed HCEC migration. Western blotting showed that bevacizumab treatment decreased the expression levels of phosphorylated p38 MAPK. Bevacizumab, the most widely used and investigated anti-VEGF agent, decreased epithelial cell migration and viability. Anti-VEGF agents other than bevacizumab might therefore be better for treating corneal neovascularization complicated with epithelial defects.

Improvement in the Viability of Cryopreserved Cells by Microencapsulation

NASA Astrophysics Data System (ADS)

Matsumoto, Yoshifumi; Morinaga, Yukihiro; Ujihira, Masanobu; Oka, Kotaro; Tanishita, Kazuo

The advantages of microencapsulated cells over those of suspended cells were evaluated for improving viability in cryopreservation. Rat pheochromocytoma (PC12) cells were selected as the test biological cells and then microencapsulated in alginate-polylysine-alginate membranes. These microencapsulated PC12 cells were frozen by differential scanning calorimetry (DSC) at various cooling rates, from 0.5 to 10°C/min. Their latent heat was measured during freezing from 4 to -80°C. The post-thaw viability was evaluated by dopamine-concentration measurement and by trypan blue exclusion assay. Results showed that at cooling rates of 0.5 and 1°C/min, the latent heat of microencapsulated PC12 cells was lower than that of suspended cells. This lower latent heat is caused by the fact that the extra-microcapsule froze and the intra-capsule remained unfrozen due to the formation of ice crystals in the extra-capsule space. The post-thaw viability of microencapsulated PC12 cells was improved when the cooling rate was 0.5 or 1°C/min, compared with that of suspended cells. Therefore, in microencapsulated PC12 cells, maintaining the intra-microcapsules in an unfrozen state during freezing reduces the solution effect and thus improves the post-thaw viability.

Immunomodulatory/inflammatory effects of geopropolis produced by Melipona fasciculata Smith in combination with doxorubicin on THP-1 cells.

PubMed

Oliveira, Lucas Pires Garcia; Conte, Fernanda Lopes; Cardoso, Eliza de Oliveira; Conti, Bruno José; Santiago, Karina Basso; Golim, Marjorie de Assis; Cruz, Maria Teresa; Sforcin, José Maurício

2016-12-01

Geopropolis (GEO) in combination with doxorubicin (DOX) reduced HEp-2 cells viability compared to GEO and DOX alone. A possible effect of this combination on the innate immunity could take place, and its effects were analysed on THP-1 cell - a human leukaemia monocytic cell line used as a model to study monocyte activity and macrophage activity, assessing cell viability, expression of cell markers and cytokine production. THP-1 cells were incubated with GEO, DOX and their combination. Cell viability was assessed by MTT assay, cell markers expression by flow cytometry and cytokine production by ELISA. GEO + DOX did not affect cell viability. GEO alone or in combination increased TLR-4 and CD80 but not HLA-DR and TLR-2 expression. GEO stimulated TNF-α production while DOX alone or in combination did not affect it. GEO alone or in combination inhibited IL-6 production. GEO exerted a pro-inflammatory profile by increasing TLR-4 and CD80 expression and TNF-α production, favouring the activation of the immune/inflammatory response. GEO + DOX did not affect cell viability and presented an immunomodulatory action. Lower concentrations of DOX combined to GEO could be used in cancer patients, avoiding side effects and benefiting from the biological properties of GEO. © 2016 Royal Pharmaceutical Society.

Synthesis and bioevaluation of substituted chalcones, coumaranones and other flavonoids as anti-HIV agents.

PubMed

Cole, Amy L; Hossain, Sandra; Cole, Alex M; Phanstiel, Otto

2016-06-15

A series of chalcone, flavone, coumaranone and other flavonoid compounds were screened for their anti HIV-1 activity in two cell culture models using TZM-bl and PM1 cells. Within the systems evaluated, the most promising compounds contained either an α- or β-hydroxy-carbonyl motif within their structure (e.g., 8 and 9). Efficacious substituents were identified and used to design new HIV inhibitors with increased potency and lower cytotoxicity. Of the scaffolds evaluated, specific chalcones were found to provide the best balance between anti-HIV potency and low host cell toxicity. Chalcone 8l was shown to inhibit different clinical isolates of HIV in a dose-dependent manner (e.g., IC50 typically⩽5μM). Inhibition of HIV infection experiments using TZM-bl cells demonstrated that chalcone 8l and flavonol 9c had IC50 values of 4.7μM and 10.4μM, respectively. These insights were used to design new chalcones 8o and 8p. Rewardingly, chalcones 8o and 8p (at 10μM) each gave >92% inhibition of viral propagation without impacting PM1 host cell viability. Inhibition of viral propagation significantly increased (60-90%) when PM1 cells were pre-incubated with chalcone 8o, but not with the related flavonol 9c. These results suggested that chalcone 8o may be of value as both a HIV prophylactic and therapy. In summary, O-benzyl-substituted chalcones were identified as promising anti-HIV agents for future investigation. Copyright © 2016 Elsevier Ltd. All rights reserved.

The Center for HIV/AIDS Vaccine Immunology (CHAVI) Multi-site Quality Assurance Program for Cryopreserved Human Peripheral Blood Mononuclear Cells

PubMed Central

Sarzotti-Kelsoe, Marcella; Needham, Leila K.; Rountree, Wes; Bainbridge, John; Gray, Clive M.; Fiscus, Susan A.; Ferrari, Guido; Stevens, Wendy S.; Stager, Susan L.; Binz, Whitney; Louzao, Raul; Long, Kristy O.; Mokgotho, Pauline; Moodley, Niranjini; Mackay, Melanie; Kerkau, Melissa; McMillion, Takesha; Kirchherr, Jennifer; Soderberg, Kelly A.; Haynes, Barton F.; Denny, Thomas N.

2014-01-01

The Center for HIV/AIDS Vaccine Immunology (CHAVI) consortium was established to determine the host and virus factors associated with HIV transmission, infection and containment of virus replication, with the goal of advancing the development of an HIV protective vaccine. Studies to meet this goal required the use of cryopreserved Peripheral Blood Mononuclear Cell (PBMC) specimens, and therefore it was imperative that a quality assurance (QA) oversight program be developed to monitor PBMC samples obtained from study participants at multiple international sites. Nine site-affiliated laboratories in Africa and the USA collected and processed PBMCs, and cryopreserved PBMC were shipped to CHAVI repositories in Africa and the USA for long-term storage. A three-stage program was designed, based on Good Clinical Laboratory Practices (GCLP), to monitor PBMC integrity at each step of this process. The first stage evaluated the integrity of fresh PBMCs for initial viability, overall yield, and processing time at the site-affiliated laboratories (Stage 1); for the second stage, the repositories determined post-thaw viability and cell recovery of cryopreserved PBMC, received from the site-affiliated laboratories (Stage 2); the third stage assessed the long-term specimen storage at each repository (Stage 3). Overall, the CHAVI PBMC QA oversight program results highlight the relative importance of each of these stages to the ultimate goal of preserving specimen integrity from peripheral blood collection to long-term repository storage. PMID:24910414

Dexamethasone palmitate ameliorates macrophages-rich graft-versus-host disease by inhibiting macrophage functions.

PubMed

Nishiwaki, Satoshi; Nakayama, Takayuki; Murata, Makoto; Nishida, Tetsuya; Terakura, Seitaro; Saito, Shigeki; Kato, Tomonori; Mizuno, Hiroki; Imahashi, Nobuhiko; Seto, Aika; Ozawa, Yukiyasu; Miyamura, Koichi; Ito, Masafumi; Takeshita, Kyosuke; Kato, Hidefumi; Toyokuni, Shinya; Nagao, Keisuke; Ueda, Ryuzo; Naoe, Tomoki

2014-01-01

Macrophage infiltration of skin GVHD lesions correlates directly with disease severity, but the mechanisms underlying this relationship remain unclear and GVHD with many macrophages is a therapeutic challenge. Here, we characterize the macrophages involved in GVHD and report that dexamethasone palmitate (DP), a liposteroid, can ameliorate such GVHD by inhibiting macrophage functions. We found that host-derived macrophages could exacerbate GVHD in a mouse model through expression of higher levels of pro-inflammatory TNF-α and IFN-γ, and lower levels of anti-inflammatory IL-10 than resident macrophages in mice without GVHD. DP significantly decreased the viability and migration capacity of primary mouse macrophages compared to conventional dexamethasone in vitro. DP treatment on day 7 and day 14 decreased macrophage number, and attenuated GVHD score and subsequent mortality in a murine model. This is the first study to provide evidence that therapy for GVHD should be changed on the basis of infiltrating cell type.

Elimination of HIV-1 Genomes from Human T-lymphoid Cells by CRISPR/Cas9 Gene Editing

PubMed Central

Kaminski, Rafal; Chen, Yilan; Fischer, Tracy; Tedaldi, Ellen; Napoli, Alessandro; Zhang, Yonggang; Karn, Jonathan; Hu, Wenhui; Khalili, Kamel

2016-01-01

We employed an RNA-guided CRISPR/Cas9 DNA editing system to precisely remove the entire HIV-1 genome spanning between 5′ and 3′ LTRs of integrated HIV-1 proviral DNA copies from latently infected human CD4+ T-cells. Comprehensive assessment of whole-genome sequencing of HIV-1 eradicated cells ruled out any off-target effects by our CRISPR/Cas9 technology that might compromise the integrity of the host genome and further showed no effect on several cell health indices including viability, cell cycle and apoptosis. Persistent co-expression of Cas9 and the specific targeting guide RNAs in HIV-1-eradicated T-cells protected them against new infection by HIV-1. Lentivirus-delivered CRISPR/Cas9 significantly diminished HIV-1 replication in infected primary CD4+ T-cell cultures and drastically reduced viral load in ex vivo culture of CD4+ T-cells obtained from HIV-1 infected patients. Thus, gene editing using CRISPR/Cas9 may provide a new therapeutic path for eliminating HIV-1 DNA from CD4+ T-cells and potentially serve as a novel and effective platform toward curing AIDS. PMID:26939770

Cell viability in optical tweezers: high power red laser diode versus Nd:YAG laser

NASA Astrophysics Data System (ADS)

Schneckenburger, Herbert; Hendinger, Anita; Sailer, Reinhard; Gschwend, Michael H.; Strauss, Wolfgang S.; Bauer, Manfred; Schuetze, Karin

2000-01-01

Viability of cultivated Chinese hamster ovary cells in optical tweezers was measured after exposure to various light doses of red high power laser diodes ((lambda) equals 670 - 680 nm) and a Nd:yttrium-aluminum-garnet laser ((lambda) equals 1064 nm). When using a radiant exposure of 2.4 GJ/cm2, a reduction of colony formation up to a factor 2 (670 - 680 nm) or 1.6 (1064 nm) as well as a delay of cell growth were detected in comparison with nonirradiated controls. In contrast, no cell damage was found at an exposure of 340 MJ/cm2 applied at 1064 nm. Cell viabilities were correlated with fluorescence excitation spectra and with literature data of wavelength dependent cloning efficiencies. Fluorescence excitation maxima of the coenzymes NAD(P)H and flavins were detected at 365 and 450 nm, respectively. This is half of the wavelengths of the maxima of cell inactivation, suggesting that two-photon absorption by these coenzymes may contribute to cellular damage. Two-photon excitation of NAD(P)H and flavins may also affect cell viability after exposure to 670 - 680 nm, whereas one-photon excitation of water molecules seems to limit cell viability at 1064 nm.

Paraoxonase 2 modulates a proapoptotic function in LS174T cells in response to quorum sensing molecule N-(3-oxododecanoyl)-L-homoserine lactone

PubMed Central

Tao, Shiyu; Luo, Yanwen; Bin He; Liu, Jie; Qian, Xi; Ni, Yingdong; Zhao, Ruqian

2016-01-01

A mucus layer coats the gastrointestinal tract and serves as the first line of intestinal defense against infection. N-acyl-homoserine lactone (AHL) quorum-sensing molecules produced by gram-negative bacteria in the gut can influence the homeostasis of intestinal epithelium. In this study, we investigated the effects of two representative long- and short-chain AHLs, N-3-(oxododecanoyl)-homoserine lactone (C12-HSL) and N-butyryl homoserine lactone (C4-HSL), on cell viability and mucus secretion in LS174T cells. C12-HSL but not C4-HSL significantly decreased cell viability by inducing mitochondrial dysfunction and activating cell apoptosis which led to a decrease in mucin expression. Pretreatment with lipid raft disruptor (Methyl-β-cyclodextrin, MβCD) and oxidative stress inhibitor (N-acetyl-L-cysteine, NAC) slightly rescued the viability of cells damaged by C12-HSL exposure, while the paraoxonase 2 (PON2) inhibitor (Triazolo[4,3-a]quinolone, TQ416) significantly affected recovering cells viability and mucin secretion. When LS174T cells were treated with C12-HSL and TQ416 simultaneously, TQ416 showed the maximal positive effect on cells viability. However, if cells were first treated with C12-HSL for 40 mins, and then TQ46 was added, the TQ416 had no effect on cell viability. These results suggest that the C12-HSL-acid process acts at an early step to activate apoptosis as part of C12-HSL’s effect on intestinal mucus barrier function. PMID:27364593

Nitric Oxide as a Biomarker of Intracellular Salmonella Viability and Identification of the Bacteriostatic Activity of Protein Kinase A Inhibitor H-89

PubMed Central

He, Haiqi; Genovese, Kenneth J.; Swaggerty, Christina L.; Nisbet, David J.; Kogut, Michael H.

2013-01-01

Salmonella enterica serovar Enteritidis is one of the most prevalent Salmonella serovars in poultry and is often associated with human salmonellosis. S. Enteritidis is known to suppress nitric oxide (NO) production in infected chicken macrophage HD11 cells, while dead S. Enteritidis stimulates a high level of NO production, suggesting a bacterial inhibitory effect on NO production. Based on these observations, the present study was conducted to evaluate whether NO production in S. Enteritidis-infected HD11 cells can be used as a biomarker to identify molecules that kill intracellular Salmonella. Since Salmonella are known to manipulate the host cell kinase network to facilitate intracellular survival, we screened a group of pharmaceutical inhibitors of various kinases to test our hypothesis. A protein kinase A inhibitor, H-89, was found to reverse the suppression of NO production in S. Enteritidis-infected HD11 cells. Production of NO in S. Enteritidis-infected HD11 cells increased significantly following treatment with H-89 at or above 20 µM. Inversely, the number of viable intracellular Salmonella decreased significantly in cells treated with H-89 at or above 30 µM. Furthermore, the growth rate of S. Enteritidis in culture was significantly inhibited by H-89 at concentrations from 20 to 100 µM. Our results demonstrate that NO-based screening using S. Enteritidis-infected HD11 cells is a viable tool to identify chemicals with anti-intracellular Salmonella activity. Using this method, we have shown H-89 has bacteriostatic activity against Salmonella, independent of host cell protein kinase A or Akt1 activity. PMID:23554945

Nitric oxide as a biomarker of intracellular Salmonella viability and identification of the bacteriostatic activity of protein kinase A inhibitor H-89.

PubMed

He, Haiqi; Genovese, Kenneth J; Swaggerty, Christina L; Nisbet, David J; Kogut, Michael H

2013-01-01

Salmonella enterica serovar Enteritidis is one of the most prevalent Salmonella serovars in poultry and is often associated with human salmonellosis. S. Enteritidis is known to suppress nitric oxide (NO) production in infected chicken macrophage HD11 cells, while dead S. Enteritidis stimulates a high level of NO production, suggesting a bacterial inhibitory effect on NO production. Based on these observations, the present study was conducted to evaluate whether NO production in S. Enteritidis-infected HD11 cells can be used as a biomarker to identify molecules that kill intracellular Salmonella. Since Salmonella are known to manipulate the host cell kinase network to facilitate intracellular survival, we screened a group of pharmaceutical inhibitors of various kinases to test our hypothesis. A protein kinase A inhibitor, H-89, was found to reverse the suppression of NO production in S. Enteritidis-infected HD11 cells. Production of NO in S. Enteritidis-infected HD11 cells increased significantly following treatment with H-89 at or above 20 µM. Inversely, the number of viable intracellular Salmonella decreased significantly in cells treated with H-89 at or above 30 µM. Furthermore, the growth rate of S. Enteritidis in culture was significantly inhibited by H-89 at concentrations from 20 to 100 µM. Our results demonstrate that NO-based screening using S. Enteritidis-infected HD11 cells is a viable tool to identify chemicals with anti-intracellular Salmonella activity. Using this method, we have shown H-89 has bacteriostatic activity against Salmonella, independent of host cell protein kinase A or Akt1 activity.

A combined approach for the assessment of cell viability and cell functionality of human fibrochondrocytes for use in tissue engineering.

PubMed

Garzón, Ingrid; Carriel, Victor; Marín-Fernández, Ana Belén; Oliveira, Ana Celeste; Garrido-Gómez, Juan; Campos, Antonio; Sánchez-Quevedo, María Del Carmen; Alaminos, Miguel

2012-01-01

Temporo-mandibular joint disc disorders are highly prevalent in adult populations. Autologous chondrocyte implantation is a well-established method for the treatment of several chondral defects. However, very few studies have been carried out using human fibrous chondrocytes from the temporo-mandibular joint (TMJ). One of the main drawbacks associated to chondrocyte cell culture is the possibility that chondrocyte cells kept in culture tend to de-differentiate and to lose cell viability under in in-vitro conditions. In this work, we have isolated human temporo-mandibular joint fibrochondrocytes (TMJF) from human disc and we have used a highly-sensitive technique to determine cell viability, cell proliferation and gene expression of nine consecutive cell passages to determine the most appropriate cell passage for use in tissue engineering and future clinical use. Our results revealed that the most potentially viable and functional cell passages were P5-P6, in which an adequate equilibrium between cell viability and the capability to synthesize all major extracellular matrix components exists. The combined action of pro-apoptotic (TRAF5, PHLDA1) and anti-apoptotic genes (SON, HTT, FAIM2) may explain the differential cell viability levels that we found in this study. These results suggest that TMJF should be used at P5-P6 for cell therapy protocols.

Fluorescein diacetate for determination of cell viability in 3D fibroblast-collagen-GAG constructs.

PubMed

Powell, Heather M; Armour, Alexis D; Boyce, Steven T

2011-01-01

Quantification of cell viability and distribution within engineered tissues currently relies on representative histology, phenotypic assays, and destructive assays of viability. To evaluate uniformity of cell density throughout 3D collagen scaffolds prior to in vivo use, a nondestructive, field assessment of cell viability is advantageous. Here, we describe a field measure of cell viability in lyophilized collagen-glycosaminoglycan (C-GAG) scaffolds in vitro using fluorescein diacetate (FdA). Fibroblast-C-GAG constructs are stained 1 day after cellular inoculation using 0.04 mg/ml FdA followed by exposure to 366 nm UV light. Construct fluorescence quantified using Metamorph image analysis is correlated with inoculation density, MTT values, and histology of corresponding biopsies. Construct fluorescence correlates significantly with inoculation density (p  <  0.001) and MTT values (p  <  0.001) of biopsies collected immediately after FdA staining. No toxicity is detected in the constructs, as measured by MTT assay before and after the FdA assay at different time points; normal in vitro histology is demonstrated for the FdA-exposed constructs. In conclusion, measurement of intracellular fluorescence with FdA allows for the early, comprehensive measurement of cellular distributions and viability in engineered tissue.

High Modulus Biodegradable Polyurethanes for Vascular Stents: Evaluation of Accelerated in vitro Degradation and Cell Viability of Degradation Products

PubMed Central

Sgarioto, Melissa; Adhikari, Raju; Gunatillake, Pathiraja A.; Moore, Tim; Patterson, John; Nagel, Marie-Danielle; Malherbe, François

2015-01-01

We have recently reported the mechanical properties and hydrolytic degradation behavior of a series of NovoSorb™ biodegradable polyurethanes (PUs) prepared by varying the hard segment (HS) weight percentage from 60 to 100. In this study, the in vitro degradation behavior of these PUs with and without extracellular matrix (ECM) coating was investigated under accelerated hydrolytic degradation (phosphate buffer saline; PBS/70°C) conditions. The mass loss at different time intervals and the effect of aqueous degradation products on the viability and growth of human umbilical vein endothelial cells (HUVEC) were examined. The results showed that PUs with HS 80% and below completely disintegrated leaving no visual polymer residue at 18 weeks and the degradation medium turned acidic due to the accumulation of products from the soft segment (SS) degradation. As expected the PU with the lowest HS was the fastest to degrade. The accumulated degradation products, when tested undiluted, showed viability of about 40% for HUVEC cells. However, the viability was over 80% when the solution was diluted to 50% and below. The growth of HUVEC cells is similar to but not identical to that observed with tissue culture polystyrene standard (TCPS). The results from this in vitro study suggested that the PUs in the series degraded primarily due to the SS degradation and the cell viability of the accumulated acidic degradation products showed poor viability to HUVEC cells when tested undiluted, however particles released to the degradation medium showed cell viability over 80%. PMID:26000274

Assessment of cryopreserved donor skin viability: the experience of the regional tissue bank of Siena.

PubMed

Pianigiani, E; Tognetti, L; Ierardi, F; Mariotti, G; Rubegni, P; Cevenini, G; Perotti, R; Fimiani, M

2016-06-01

Skin allografts from cadaver donors are an important resource for treating extensive burns, slow-healing wounds and chronic ulcers. A high level of cell viability of cryopreserved allografts is often required, especially in burn surgery, in Italy. Thus, we aimed to determine which conditions enable procurement of highly viable skin in our Regional Skin Bank of Siena. For this purpose, we assessed cell viability of cryopreserved skin allografts procured between 2011 and 2013 from 127 consecutive skin donors, before and after freezing (at day 15, 180, and 365). For each skin donor, we collected data concerning clinical history (age, sex, smoking, phototype, dyslipidemia, diabetes, cause of death), donation process (multi-tissue or multi-organ) and timing of skin procurement (assessment of intervals such as death-harvesting, harvesting-banking, death-banking). All these variables were analysed in the whole case study (127 donors) and in different groups (e.g. multi-organ donors, non refrigerated multi-tissue donors, refrigerated multi-tissue donors) for correlations with cell viability. Our results indicated that cryopreserved skin allografts with higher cell viability were obtained from female, non smoker, heartbeating donors died of cerebral haemorrhage, and were harvested within 2 h of aortic clamping and banked within 12 h of harvesting (13-14 h from clamping). Age, cause of death and dyslipidaemia or diabetes did not appear to influence cell viability. To maintain acceptable cell viability, our skin bank needs to reduce the time interval between harvesting and banking, especially for refrigerated donors.

Maintenance and assessment of cell viability in formulation of non-sporulating bacterial inoculants.

PubMed

Berninger, Teresa; González López, Óscar; Bejarano, Ana; Preininger, Claudia; Sessitsch, Angela

2018-03-01

The application of beneficial, plant-associated microorganisms is a sustainable approach to improving crop performance in agriculture. However, microbial inoculants are often susceptible to prolonged periods of storage and deleterious environmental factors, which negatively impact their viability and ultimately limit efficacy in the field. This particularly concerns non-sporulating bacteria. To overcome this challenge, the availability of protective formulations is crucial. Numerous parameters influence the viability of microbial cells, with drying procedures generally being among the most critical ones. Thus, technological advances to attenuate the desiccation stress imposed on living cells are key to successful formulation development. In this review, we discuss the core aspects important to consider when aiming at high cell viability of non-sporulating bacteria to be applied as microbial inoculants in agriculture. We elaborate the suitability of commonly applied drying methods (freeze-drying, vacuum-drying, spray-drying, fluidized bed-drying, air-drying) and potential measures to prevent cell damage from desiccation (externally applied protectants, stress pre-conditioning, triggering of exopolysaccharide secretion, 'helper' strains). Furthermore, we point out methods for assessing bacterial viability, such as colony counting, spectrophotometry, microcalorimetry, flow cytometry and viability qPCR. Choosing appropriate technologies for maintenance of cell viability and evaluation thereof will render formulation development more efficient. This in turn will aid in utilizing the vast potential of promising, plant beneficial bacteria as sustainable alternatives to standard agrochemicals. © 2018 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

Synthetic vs natural scaffolds for human limbal stem cells

PubMed Central

Tominac Trcin, Mirna; Dekaris, Iva; Mijović, Budimir; Bujić, Marina; Zdraveva, Emilija; Dolenec, Tamara; Pauk-Gulić, Maja; Primorac, Dragan; Crnjac, Josip; Špoljarić, Branimira; Mršić, Gordan; Kuna, Krunoslav; Špoljarić, Daniel; Popović, Maja

2015-01-01

Aim To investigate the impact of synthetic electrospun polyurethane (PU) and polycaprolactone (PCL) nanoscaffolds, before and after hydrolytic surface modification, on viability and differentiation of cultured human eye epithelial cells, in comparison with natural scaffolds: fibrin and human amniotic membrane. Methods Human placenta was taken at elective cesarean delivery. Fibrin scaffolds were prepared from commercial fibrin glue kits. Nanoscaffolds were fabricated by electrospinning. Limbal cells were isolated from surpluses of human cadaveric cornea and seeded on feeder 3T3 cells. The scaffolds used for viability testing and immunofluorescence analysis were amniotic membrane, fibrin, PU, and PCL nanoscaffolds, with or without prior NaOH treatment. Results Scanning electron microscope photographs of all tested scaffolds showed good colony spreading of seeded limbal cells. There was a significant difference in viability performance between cells with highest viability cultured on tissue culture plastic and cells cultured on all other scaffolds. On the other hand, electrospun PU, PCL, and electrospun PCL treated with NaOH had more than 80% of limbal cells positive for stem cell marker p63 compared to only 27%of p63 positive cells on fibrin. Conclusion Natural scaffolds, fibrin and amniotic membrane, showed better cell viability than electrospun scaffolds. On the contrary, high percentages of p63 positive cells obtained on these scaffolds still makes them good candidates for efficient delivery systems for therapeutic purposes. PMID:26088849

Effect of laser energy, substrate film thickness and bioink viscosity on viability of endothelial cells printed by Laser-Assisted Bioprinting

NASA Astrophysics Data System (ADS)

Catros, Sylvain; Guillotin, Bertrand; Bačáková, Markéta; Fricain, Jean-Christophe; Guillemot, Fabien

2011-04-01

Biofabrication of three dimensional tissues by Laser-Assisted Bioprinting (LAB) implies to develop specific strategies for assembling the extracellular matrix (ECM) and cells. Possible strategies consist in (i) printing cells onto or in the depth of ECM layer and/or (ii) printing bioinks containing both cells and ECM-like printable biomaterial. The aim of this article was to evaluate combinatorial effects of laser pulse energy, ECM thickness and viscosity of the bioink on cell viability. A LAB workstation was used to print Ea.hy926 endothelial cells onto a quartz substrate covered with a film of ECM mimicking Matrigel™. Hence, effect of laser energy, Matrigel™ film thickness and bioink viscosity was addressed for different experimental conditions (8-24 μJ, 20-100 μm and 40-110 mPa s, respectively). Cell viability was assessed by live/dead assay performed 24 h post-printing. Results show that increasing the laser energy tends to augment the cell mortality while increasing the thickness of the Matrigel™ film and the viscosity of the bioink support cell viability. Hence, critical printing parameters influencing high cell viability have been related to the cell landing conditions and more specifically to the intensity of the cell impacts occurring at the air-ECM interface and at the ECM-glass interface.

Effects of Non-Collagenous Proteins, TGF-β1, and PDGF-BB on Viability and Proliferation of Dental Pulp Stem Cells

PubMed Central

Tabatabaei, Fahimeh Sadat

2016-01-01

ABSTRACT Objectives The dentin matrix servers as a reservoir of growth factors, sequestered during dentinogenesis. The aim of this study was to assess the viability and proliferation of dental pulp stem cells in the presence of dentin matrix-derived non-collagenous proteins and two growth factors; platelet-derived growth factor BB and transforming growth factor beta 1. Material and Methods The dental pulp cells were isolated and cultured. The dentin proteins were extracted and purified. The MTT assay was performed for assessment of cell viability and proliferation in the presence of different concentrations of dentin proteins and growth factors during 24 - 72 h post-treatment. Results The cells treated with 250 ng/mL dentin proteins had the best viability and proliferation ability in comparison with other concentrations (P < 0.05). The MTT assay demonstrated that cells cultured with 5 ng/mL platelet-derived growth factor BB had the highest viability at each time point as compared to other groups (P < 0.05). However, in presence of platelet-derived growth factor BB alone and in combination with transforming growth factor beta 1 and dentin proteins (10 ng/mL), significant higher viability was seen at all time points (P < 0.05). The least viability and proliferation at each growth factor concentration was seen in cells treated with combination of transforming growth factor beta 1 and dentin proteins at 72 h (P < 0.05). Conclusions The results indicated that the triple combination of growth factors and matrix-derived non-collagenous proteins (especially at 10 ng/mL concentration) has mitogenic effect on dental pulp stem cells. PMID:27099698

Evaluation of a Mouse Embryonic Stem Cell Adherent Cell Differentiation and Cytotoxicity (ACDC) assay (SOT)

EPA Science Inventory

The Embryonic Stem Cell Test (EST) has been used to evaluate the effects of xenobiotics using three endpoints, stem cell differentiation, stem cell viability and 3T3-cell viability. Our research goal is to establish amodel system that would evaluate chemical effects using a singl...

How effectors promote beneficial interactions.

PubMed

Miwa, Hiroki; Okazaki, Shin

2017-08-01

Beneficial microbes such as rhizobia possess effector proteins that are secreted into the host cytoplasm where they modulate host-signaling pathways. Among these effectors, type 3 secreted effectors (T3Es) of rhizobia play roles in promoting nitrogen-fixing nodule symbiosis, suppressing host defenses and directly activating symbiosis-related processes. Rhizobia use the same strategy as pathogenic bacteria to suppress host defenses such as targeting the MAPK cascade. In addition, rhizobial T3E can promote root nodule symbiosis by directly activating Nod factor signaling, which bypasses Nod factor perception. The various strategies employed by beneficial microbes to promote infection and maintain viability in the host are therefore crucial for plant endosymbiosis. Copyright © 2017 Elsevier Ltd. All rights reserved.

Ability of Nonpathogenic Fusarium oxysporum Strain Fo47 To Induce Resistance against Pythium ultimum Infection in Cucumber

PubMed Central

Benhamou, Nicole; Garand, Chantal; Goulet, Alain

2002-01-01

The influence exerted by nonpathogenic Fusarium oxysporum strain Fo47 in triggering cucumber protection against infection by Pythium ultimum was investigated ultrastructurally. Macroscopic and microscopic observations of the pathogen colony in dual cultures revealed that reduction of Pythium growth was associated with marked disorders, including generalized disorganization of the host cytoplasm, retraction of the plasmalemma, and complete loss of the protoplasm. Cytochemical labeling of cellulose with an exoglucanase-gold complex showed that the cellulose component of the host cell walls was structurally preserved at a time when the host cytoplasm had undergone complete disorganization. A similar antagonistic process was observed at the root cell surface. Most striking and interesting was the finding that mycoparasitism, as evidenced by the frequent occurrence of Fo47 hyphae within nearly empty cells of the pathogen, occurred not only at the root surface but also within the invaded root tissues. The specific labeling pattern obtained with the exoglucanase-gold complex confirmed that Fo47 successfully penetrated cells of the pathogen, both in the rhizosphere and inside the root tissues. Pythium cells that could evade the first defensive line in the rhizosphere could penetrate the root epidermis, but their growth was restricted to the outermost tissues. Positive correlations between Fo47 treatment and induced resistance to infection by P. ultimum in cucumber were confirmed by (i) the reduction of pathogen viability; (ii) the elaboration of newly formed barriers, a phenomenon which was not seen in Fo47-free plants, where the pathogen proliferated in all root tissues within a few days; and (iii) the occlusion of intercellular spaces with a dense material likely enriched in phenolics. Taken together, our observations provide the first convincing evidence that Fo47 exerts a direct inhibitory effect on P. ultimum through a combination of antibiosis and mycoparasitism, in addition to being a strong inducer of plant defense reactions. PMID:12147506

Mouse Embryonic Stem Cell Adherent Cell Differentiation and Cytotoxicity (ACDC) assay

EPA Science Inventory

The Embryonic Stem Cell Test (EST) is an assay which evaluates xenobiotic-induced effects using three endpoints: mouse embryonic stem cell (mESC) differentiation, mESC viability, and 3T3-cell viability. Our research goal was to develop an improved high-throughput assay by establi...

Effects of P Element Insertions on Quantitative Traits in Drosophila Melanogaster

PubMed Central

Mackay, TFC.; Lyman, R. F.; Jackson, M. S.

1992-01-01

P element mutagenesis was used to construct 94 third chromosome lines of Drosophila melanogaster which contained on average 3.1 stable P element inserts, in an inbred host strain background previously free of P elements. The homozygous and heterozygous effects of the inserts on viability and abdominal and sternopleural bristle number were ascertained by comparing the chromosome lines with inserts to insert-free control lines of the inbred host strain. P elements reduced average homozygous viability by 12.2% per insert and average heterozygous viability by 5.5% per insert, and induced recessive lethal mutations at a rate of 3.8% per insert. Mutational variation for the bristle traits averaged over both sexes was 0.03V(e) per homozygous P insert and 0.003V(e) per heterozygous P insert, where V(e) is the environmental variance. Mutational variation was greater for the sexes considered separately because inserts had large pleiotropic effects on sex dimorphism of bristle characters. The distributions of homozygous effects of inserts on the bristle traits were asymmetrical, with the largest effects in the direction of reducing bristle number; and highly leptokurtic, with most of the increase in variance contributed by a few lines with large effects. The inserts had partially recessive effects on the bristle traits. Insert lines with extreme bristle effects had on average greatly reduced viability. PMID:1311697

Role and mechanism of the Hsp70 molecular chaperone machines in bacterial pathogens.

PubMed

Ghazaei, Ciamak

2017-03-01

Heat shock proteins are highly conserved, stress-inducible, ubiquitous proteins that maintain homeostasis in both eukaryotes and prokaryotes. Hsp70 proteins belong to the heat shock protein family and enhance bacterial survival in hostile environments. Hsp70, known as DnaK in prokaryotes, supports numerous processes such as the assembly and disassembly of protein complexes, the refolding of misfolded and clustered proteins, membrane translocation and the regulation of regulatory proteins. The chaperone-based activity of Hsp70 depends on dynamic interactions between its two domains, known as the ATPase domain and the substrate-binding domain. It also depends on interactions between these domains and other co-chaperone molecules such as the Hsp40 protein family member DnaJ and nucleotide exchange factors. DnaJ is the primary chaperone that interacts with nascent polypeptide chains and functions to prevent their premature release from the ribosome and misfolding before it is targeted by DnaK. Adhesion of bacteria to host cells is mediated by both host and bacterial Hsp70. Following infection of the host, bacterial Hsp70 (DnaK) is in a position to initiate bacterial survival processes and trigger an immune response by the host. Any mutations in the dnaK gene have been shown to decrease the viability of bacteria inside the host. This review will give insights into the structure and mechanism of Hsp70 and its role in regulating the protein activity that contributes to pathogenesis.

ROS-induced oxidative stress and apoptosis-like event directly affect the cell viability of cryopreserved embryogenic callus in Agapanthus praecox.

PubMed

Zhang, Di; Ren, Li; Chen, Guan-Qun; Zhang, Jie; Reed, Barbara M; Shen, Xiao-Hui

2015-09-01

Oxidative stress and apoptosis-like programmed cell death, induced in part by H 2 O 2 , are two key factors that damage cells during plant cryopreservation. Their inhibition can improve cell viability. We hypothesized that oxidative stress and apoptosis-like event induced by ROS seriously impact plant cell viability during cryopreservation. This study documented changes in cell morphology and ultrastructure, and detected dynamic changes in ROS components (O 2 (·-) , H2O2 and OH·), antioxidant systems, and programmed cell death (PCD) events during embryonic callus cryopreservation of Agapanthus praecox. Plasmolysis, organelle ultrastructure changes, and increases in malondialdehyde (a membrane lipid peroxidation product) suggested that oxidative damage and PCD events occurred at several early cryopreservation steps. PCD events including autophagy, apoptosis-like, and necrosis also occurred at later stages of cryopreservation, and most were apoptosis. H2O2 is the most important ROS molecule mediating oxidative damage and affecting cell viability, and catalase and AsA-GSH cycle are involved in scavenging the intracellular H2O2 and protecting the cells against stress damage in the whole process. Gene expression studies verified changes of antioxidant system and PCD-related genes at the main steps of the cryopreservation process that correlated with improved cell viability. Reducing oxidative stress or inhibition of apoptosis-like event by deactivating proteases improved cryopreserved cell viability from 49.14 to 86.85 % and 89.91 %, respectively. These results verify our model of ROS-induced oxidative stress and apoptosis-like event in plant cryopreservation. This study provided a novel insight into cell stress response mechanisms in cryopreservation.

Viability of HEK 293 cells on poly-β-hydroxybutyrate (PHB) biosynthesized from a mutant Azotobacter vinelandii strain. Cast film and electrospun scaffolds.

PubMed

Romo-Uribe, Angel; Meneses-Acosta, Angelica; Domínguez-Díaz, Maraolina

2017-12-01

Sterilization, cytotoxicity and cell viability are essential properties defining a material for medical applications and these characteristics were investigated for poly(β-hydroxybutyrate) (PHB) of 230kDa obtained by bacterial synthesis from a mutant strain of Azotobacter vinelandii. Cell viability was investigated for two types of PHB scaffolds, solution cast films and non-woven electrospun fibrous membranes, and the efficiency was compared against a culture dish. The biosynthesized PHB was sterilized by ultraviolet radiation and autoclave, it was found that the thermal properties and intrinsic viscosity remained unchanged indicating that the sterilization methods did not degrade the polymer. Sterilized scaffolds were then seeded with human embryonic kidney 293 (HEK 293) cells to evaluate the cytotoxic response. The cell viability of these cells was evaluated for up to six days, and the results showed that the cell morphology was normal, with no cytotoxic effects. The films and electrospun membranes exhibited over 95% cell viability whereas the viability in culture dishes reached only ca. 90%. The electrospun membrane, however, exhibited significantly higher cell density than the cast film suggesting that the fibrous morphology enables better nutrients transfer. The results indicate that the biosynthesized PHB stands UV and autoclave sterilization methods, it is biocompatible and non-toxic for cell growth of human cell lines. Furthermore, cell culture for up to 18 days showed that 62% and 90% of mass was lost for the film and fibrous electrospun scaffold, respectively. This is a favorable outcome for use in tissue engineering where material degradation, as tissue regenerates, is desirable. Copyright © 2017 Elsevier B.V. All rights reserved.

L929 cell cytotoxicity associated with experimental and commercial dental flosses

NASA Astrophysics Data System (ADS)

Tua-ngam, P.; Supanitayanon, L.; Dechkunakorn, S.; Anuwongnukroh, N.; Srikhirin, T.; Roongrujimek, P.

2017-11-01

This aim of the study was to investigate the cytotoxicity of two commercial and two experimental dental flosses. Two commercial, Oral B® Essential Floss (nylon-waxed) and Thai Silk Floss (silk-waxed), and two experimental, Floss X (nylon-waxed) and Floss Xu (nylon-unwaxed) dental flosses were used. The cytotoxic assay was performed by using cell cultures (L929) which were subjected to cell viability test with methyl-tetrazolium. Each floss specimen (0.4 g) was placed in 1 ml of Minimum Essential Medium at 37°C with 5% CO2 at 100% humidity in an incubator for 24 hours. After incubation, the cell mitochondrial activity was evaluated for detecting viable cells using optical density as per the guidelines of ISO 10993-5:2009(E). Cytotoxic effects were evaluated by measuring percentage of cell viability at 3 points of time- 5 mins, 30 mins, and 1 hr. The results showed that two commercial dental flosses and Floss X had cell viability about 90% at the three time points; however, the experimental Floss Xu presented 80% cell viability at 5 min and <70% cell viability at 30 min and 1 hr. The results concluded that the commercial dental flosses and the experimental dental floss with wax tested in this study were acceptable for clinical use.

Cell morphology, viability, osteocalcin activity, and alkaline phosphatase activity in milled versus unmilled surface of the femoral head.

PubMed

Rhyu, Kee Hyung; Cho, Chang Hoon; Yoon, Kyung Sik; Chun, Young Soo

2016-12-01

To evaluate cellular activity in milled versus unmilled surface of the femoral head in 21 patients who underwent robot-assisted total hip arthroplasty(THA). The femoral head of 21 consecutive patients who underwent robot-assisted THA for osteonecrosis was used. 10 cc of trabecular bone from the entire milled surface was obtained using a curette. The same amount of trabecular bone was obtained at least 1 cm away from the milled surface and served as a matched control. Cell morphology, viability, osteocalcin activity, and alkaline phosphatase activity in milled versus unmilled surface were assessed. Cell morphology of the milled or unmilled surface was comparable; cells were smaller in the milled surface. Cell viability was a mean of 40% higher in the milled surface (107.4% vs. 67.2%, p<0.001); cell viability at 5 time points was comparable in each group. Osteocalcin activity of cells was slightly higher in the milled surface (1.43 vs. 1.24 ng/ml, p=0.69). Alkaline phosphatase activity of cells was slightly higher in the unmilled surface (150 105 vs. 141 789 U/L, p=0.078). The milled and unmilled surfaces of the femoral head were comparable in terms of cell morphology, viability, osteocalcin activity, and alkaline phosphatase activity.

Predicting cell viability within tissue scaffolds under equiaxial strain: multi-scale finite element model of collagen-cardiomyocytes constructs.

PubMed

Elsaadany, Mostafa; Yan, Karen Chang; Yildirim-Ayan, Eda

2017-06-01

Successful tissue engineering and regenerative therapy necessitate having extensive knowledge about mechanical milieu in engineered tissues and the resident cells. In this study, we have merged two powerful analysis tools, namely finite element analysis and stochastic analysis, to understand the mechanical strain within the tissue scaffold and residing cells and to predict the cell viability upon applying mechanical strains. A continuum-based multi-length scale finite element model (FEM) was created to simulate the physiologically relevant equiaxial strain exposure on cell-embedded tissue scaffold and to calculate strain transferred to the tissue scaffold (macro-scale) and residing cells (micro-scale) upon various equiaxial strains. The data from FEM were used to predict cell viability under various equiaxial strain magnitudes using stochastic damage criterion analysis. The model validation was conducted through mechanically straining the cardiomyocyte-encapsulated collagen constructs using a custom-built mechanical loading platform (EQUicycler). FEM quantified the strain gradients over the radial and longitudinal direction of the scaffolds and the cells residing in different areas of interest. With the use of the experimental viability data, stochastic damage criterion, and the average cellular strains obtained from multi-length scale models, cellular viability was predicted and successfully validated. This methodology can provide a great tool to characterize the mechanical stimulation of bioreactors used in tissue engineering applications in providing quantification of mechanical strain and predicting cellular viability variations due to applied mechanical strain.

Is cell viability always directly related to corrosion resistance of stainless steels?

PubMed

Salahinejad, E; Ghaffari, M; Vashaee, D; Tayebi, L

2016-05-01

It has been frequently reported that cell viability on stainless steels is improved by increasing their corrosion resistance. The question that arises is whether human cell viability is always directly related to corrosion resistance in these biostable alloys. In this work, the microstructure and in vitro corrosion behavior of a new class of medical-grade stainless steels were correlated with adult human mesenchymal stem cell viability. The samples were produced by a powder metallurgy route, consisting of mechanical alloying and liquid-phase sintering with a sintering aid of a eutectic Mn-Si alloy at 1050 °C for 30 and 60 min, leading to nanostructures. In accordance with transmission electron microscopic studies, the additive particles for the sintering time of 30 min were not completely melted. Electrochemical impedance spectroscopic experiments suggested the higher corrosion resistance for the sample sintered for 60 min; however, a better cell viability on the surface of the less corrosion-resistant sample was unexpectedly found. This behavior is explained by considering the higher ion release rate of the Mn-Si additive material, as preferred sites to corrosion attack based on scanning electron microscopic observations, which is advantageous to the cells in vitro. In conclusion, cell viability is not always directly related to corrosion resistance in stainless steels. Typically, the introduction of biodegradable and biocompatible phases to biostable alloys, which are conventionally anticipated to be corrosion-resistant, can be advantageous to human cell responses similar to biodegradable metals. Copyright © 2016 Elsevier B.V. All rights reserved.

Nonredundant Roles of Interleukin-17A (IL-17A) and IL-22 in Murine Host Defense against Cutaneous and Hematogenous Infection Due to Methicillin-Resistant Staphylococcus aureus

PubMed Central

Chan, Liana C.; Chaili, Siyang; Filler, Scott G.; Barr, Kevin; Wang, Huiyuan; Kupferwasser, Deborah; Edwards, John E.; Xiong, Yan Q.; Ibrahim, Ashraf S.; Miller, Lloyd S.; Schmidt, Clint S.; Hennessey, John P.

2015-01-01

Staphylococcus aureus is the leading cause of skin and skin structure infections (SSSI) in humans. Moreover, the high frequency of recurring SSSI due to S. aureus, particularly methicillin-resistant S. aureus (MRSA) strains, suggests that infection induces suboptimal anamnestic defenses. The present study addresses the hypothesis that interleukin-17A (IL-17A) and IL-22 play distinct roles in immunity to cutaneous and invasive MRSA infection in a mouse model of SSSI. Mice were treated with specific neutralizing antibodies against IL-17A and/or IL-22 and infected with MRSA, after which the severity of infection and host immune response were determined. Neutralization of either IL-17A or IL-22 reduced T cell and neutrophil infiltration and host defense peptide elaboration in lesions. These events corresponded with increased abscess severity, MRSA viability, and CFU density in skin. Interestingly, combined inhibition of IL-17A and IL-22 did not worsen abscesses but did increase gamma interferon (IFN-γ) expression at these sites. The inhibition of IL-22 led to a reduction in IL-17A expression, but not vice versa. These results suggest that the expression of IL-17A is at least partially dependent on IL-22 in this model. Inhibition of IL-17A but not IL-22 led to hematogenous dissemination to kidneys, which correlated with decreased T cell infiltration in renal tissue. Collectively, these findings indicate that IL-17A and IL-22 have complementary but nonredundant roles in host defense against cutaneous versus hematogenous infection. These insights may support targeted immune enhancement or other novel approaches to address the challenge of MRSA infection. PMID:26351278

Hyaluronic acid increases tendon derived cell viability and proliferation in vitro: comparative study of two different hyaluronic acid preparations by molecular weight.

PubMed

Gallorini, Marialucia; Berardi, Anna C; Berardocco, Martina; Gissi, Clarissa; Maffulli, Nicola; Cataldi, Amelia; Oliva, Francesco

2017-01-01

Hyaluronic Acid (HA) has been already approved by Food and Drug Administration (FDA) for osteoarthritis (OA), while its use in the treatment of tendinopathy is still debated. The aim of this study was to evaluate the effects of two different HA on human rotator cuff tendon derived cells in terms of cell viability, proliferation and apoptosis. An in vitro model was developed on human tendon derived cells from rotator cuff tears to study the effects of two different HA preparations: Sinovial HL® (High-Low molecular weight) (MW: 80-100 kDa) and KDa Sinovial Forte SF (MW: 800-1200), at various concentrations. Tendon derived cells morphology was evaluated after 0, 7 and 14 d of culture. Viability and proliferation were analyzed after 0, 24, and 48 h of culture and apoptosis occurrence was assessed after 24 h of culture. All the HAPs tested here increased viability and proliferation, in a dose-dependent manner and they reduced apoptosis at early stages (24 h) compared to control cells (without HAPs). HAPs enhanced viability and proliferation and counteracted apoptosis in tendon derived cells.

Study of wettability and cell viability of H implanted stainless steel

NASA Astrophysics Data System (ADS)

Shafique, Muhammad Ahsan; Ahmad, Riaz; Rehman, Ihtesham Ur

2018-03-01

In the present work, the effect of hydrogen ion implantation on surface wettability and biocompatibility of stainless steel is investigated. Hydrogen ions are implanted in the near-surface of stainless steel to facilitate hydrogen bonding at different doses with constant energy of 500 KeV, which consequently improve the surface wettability. Treated and untreated sample are characterized for surface wettability, incubation of hydroxyapatite and cell viability. Contact angle (CA) study reveals that surface wettability increases with increasing H-ion dose. Raman spectroscopy shows that precipitation of hydroxyapatite over the surface increase with increasing dose of H-ions. Cell viability study using MTT assay describes improved cell viability in treated samples as compared to the untreated sample. It is found that low dose of H-ions is more effective for cell proliferation and the cell count decreases with increasing ion dose. Our study demonstrates that H ion implantation improves the surface wettability and biocompatibility of stainless steel.

Engineering a prostate-specific membrane antigen-activated tumor endothelial cell prodrug for cancer therapy.

PubMed

Denmeade, Samuel R; Mhaka, Annastasiah M; Rosen, D Marc; Brennen, W Nathaniel; Dalrymple, Susan; Dach, Ingrid; Olesen, Claus; Gurel, Bora; Demarzo, Angelo M; Wilding, George; Carducci, Michael A; Dionne, Craig A; Møller, Jesper V; Nissen, Poul; Christensen, S Brøgger; Isaacs, John T

2012-06-27

Heterogeneous expression of drug target proteins within tumor sites is a major mechanism of resistance to anticancer therapies. We describe a strategy to selectively inhibit, within tumor sites, the function of a critical intracellular protein, the sarcoplasmic/endoplasmic reticulum calcium adenosine triphosphatase (SERCA) pump, whose proper function is required by all cell types for viability. To achieve targeted inhibition, we took advantage of the unique expression of the carboxypeptidase prostate-specific membrane antigen (PSMA) by tumor endothelial cells within the microenvironment of solid tumors. We generated a prodrug, G202, consisting of a PSMA-specific peptide coupled to an analog of the potent SERCA pump inhibitor thapsigargin. G202 produced substantial tumor regression against a panel of human cancer xenografts in vivo at doses that were minimally toxic to the host. On the basis of these data, a phase 1 dose-escalation clinical trial has been initiated with G202 in patients with advanced cancer.

Chimeric brain: theoretical and clinical aspects.

PubMed

Saveliev, S V; Lebedev, V V; Evgeniev, M B; Korochkin, L I

1997-12-01

Using xeno-transplantation, interactions of neural tissues of vertebrates and insects were studied. Ventral neurogenic primordium of Notch Drosophila melanogaster embryos was transplanted into neural tube of amphibian and mammalian embryos with the aid of microhydrofeeding. Embryos of four different amphibian species, random bred mice and rats were used as graft recipients. It was concluded that there is a possibility to incorporate nerve cells of insects into the brain of vertebrates. Morphological and functional contacts can be established between the transplanted cells and host brain tissues. Transplanted Drosophila cells preserve their viability for a long time, so that a prolonged influence of the transplant upon the recipient can be predicted, which may be used in medical practice. A mixture of human fetal brain and Notch Drosophila melanogaster neural embryonic tissues were transplanted into the ventro-lateral nucleus of the thalamus of the patients of Parkinson' disease. As a result, tremor and constrained movements disappeared. Post-operation patients have been observed within 13-38 months. No side effects were noted during this time.

Development of an optimized tetracycline-inducible expression system to increase the accumulation of interleukin-10 in tobacco BY-2 suspension cells

PubMed Central

2012-01-01

Background Plant cell suspension cultures can be used for the production of valuable pharmaceutical and industrial proteins. When the recombinant protein is secreted into the culture medium, restricting expression to a defined growth phase can improve both the quality and quantity of the recovered product by minimizing proteolytic activity. Temporal restriction is also useful for recombinant proteins whose constitutive expression affects cell growth and viability, such as viral interleukin-10 (vIL-10). Results We have developed a novel, tetracycline-inducible system suitable for tobacco BY-2 suspension cells which increases the yields of vIL-10. The new system is based on a binary vector that is easier to handle than conventional vectors, contains an enhanced inducible promoter and 5′-UTR to improve yields, and incorporates a constitutively-expressed visible marker gene to allow the rapid and straightforward selection of the most promising transformed clones. Stable transformation of BY-2 cells with this vector, without extensive optimization of the induction conditions, led to a 3.5 fold increase in vIL-10 levels compared to constitutive expression in the same host. Conclusions We have developed an effective and straightforward molecular farming platform technology that improves both the quality and the quantity of recombinant proteins produced in plant cells, particularly those whose constitutive expression has a negative impact on plant growth and development. Although we tested the platform using vIL-10 produced in BY-2 cells, it can be applied to other host/product combinations and is also useful for basic research requiring strictly controlled transgene expression. PMID:22784336

Impact of release dynamics of laser-irradiated polymer micropallets on the viability of selected adherent cells

PubMed Central

Ma, Huan; Mismar, Wael; Wang, Yuli; Small, Donald W.; Ras, Mat; Allbritton, Nancy L.; Sims, Christopher E.; Venugopalan, Vasan

2012-01-01

We use time-resolved interferometry, fluorescence assays and computational fluid dynamics (CFD) simulations to examine the viability of confluent adherent cell monolayers to selection via laser microbeam release of photoresist polymer micropallets. We demonstrate the importance of laser microbeam pulse energy and focal volume position relative to the glass–pallet interface in governing the threshold energies for pallet release as well as the pallet release dynamics. Measurements using time-resolved interferometry show that increases in laser pulse energy result in increasing pallet release velocities that can approach 10 m s−1 through aqueous media. CFD simulations reveal that the pallet motion results in cellular exposure to transient hydrodynamic shear stress amplitudes that can exceed 100 kPa on microsecond timescales, and which produces reduced cell viability. Moreover, CFD simulation results show that the maximum shear stress on the pallet surface varies spatially, with the largest shear stresses occurring on the pallet periphery. Cell viability of confluent cell monolayers on the pallet surface confirms that the use of larger pulse energies results in increased rates of necrosis for those cells situated away from the pallet centre, while cells situated at the pallet centre remain viable. Nevertheless, experiments that examine the viability of these cell monolayers following pallet release show that proper choices for laser microbeam pulse energy and focal volume position lead to the routine achievement of cell viability in excess of 90 per cent. These laser microbeam parameters result in maximum pallet release velocities below 6 m s−1 and cellular exposure of transient hydrodynamic shear stresses below 20 kPa. Collectively, these results provide a mechanistic understanding that relates pallet release dynamics and associated transient shear stresses with subsequent cellular viability. This provides a quantitative, mechanistic basis for determining optimal operating conditions for laser microbeam-based pallet release systems for the isolation and selection of adherent cells. PMID:22158840

Impact of release dynamics of laser-irradiated polymer micropallets on the viability of selected adherent cells.

PubMed

Ma, Huan; Mismar, Wael; Wang, Yuli; Small, Donald W; Ras, Mat; Allbritton, Nancy L; Sims, Christopher E; Venugopalan, Vasan

2012-06-07

We use time-resolved interferometry, fluorescence assays and computational fluid dynamics (CFD) simulations to examine the viability of confluent adherent cell monolayers to selection via laser microbeam release of photoresist polymer micropallets. We demonstrate the importance of laser microbeam pulse energy and focal volume position relative to the glass-pallet interface in governing the threshold energies for pallet release as well as the pallet release dynamics. Measurements using time-resolved interferometry show that increases in laser pulse energy result in increasing pallet release velocities that can approach 10 m s(-1) through aqueous media. CFD simulations reveal that the pallet motion results in cellular exposure to transient hydrodynamic shear stress amplitudes that can exceed 100 kPa on microsecond timescales, and which produces reduced cell viability. Moreover, CFD simulation results show that the maximum shear stress on the pallet surface varies spatially, with the largest shear stresses occurring on the pallet periphery. Cell viability of confluent cell monolayers on the pallet surface confirms that the use of larger pulse energies results in increased rates of necrosis for those cells situated away from the pallet centre, while cells situated at the pallet centre remain viable. Nevertheless, experiments that examine the viability of these cell monolayers following pallet release show that proper choices for laser microbeam pulse energy and focal volume position lead to the routine achievement of cell viability in excess of 90 per cent. These laser microbeam parameters result in maximum pallet release velocities below 6 m s(-1) and cellular exposure of transient hydrodynamic shear stresses below 20 kPa. Collectively, these results provide a mechanistic understanding that relates pallet release dynamics and associated transient shear stresses with subsequent cellular viability. This provides a quantitative, mechanistic basis for determining optimal operating conditions for laser microbeam-based pallet release systems for the isolation and selection of adherent cells.

A Field-Portable Cell Analyzer without a Microscope and Reagents.

PubMed

Seo, Dongmin; Oh, Sangwoo; Lee, Moonjin; Hwang, Yongha; Seo, Sungkyu

2017-12-29

This paper demonstrates a commercial-level field-portable lens-free cell analyzer called the NaviCell (No-stain and Automated Versatile Innovative cell analyzer) capable of automatically analyzing cell count and viability without employing an optical microscope and reagents. Based on the lens-free shadow imaging technique, the NaviCell (162 × 135 × 138 mm³ and 1.02 kg) has the advantage of providing analysis results with improved standard deviation between measurement results, owing to its large field of view. Importantly, the cell counting and viability testing can be analyzed without the use of any reagent, thereby simplifying the measurement procedure and reducing potential errors during sample preparation. In this study, the performance of the NaviCell for cell counting and viability testing was demonstrated using 13 and six cell lines, respectively. Based on the results of the hemocytometer ( de facto standard), the error rate (ER) and coefficient of variation (CV) of the NaviCell are approximately 3.27 and 2.16 times better than the commercial cell counter, respectively. The cell viability testing of the NaviCell also showed an ER and CV performance improvement of 5.09 and 1.8 times, respectively, demonstrating sufficient potential in the field of cell analysis.

Improved immunomagnetic enrichment of CD34(+) cells from umbilical cord blood using the CliniMACS cell separation system.

PubMed

Blake, Joseph M; Nicoud, Ian B; Weber, Daniel; Voorhies, Howard; Guthrie, Katherine A; Heimfeld, Shelly; Delaney, Colleen

2012-08-01

CD34(+) enrichment from cord blood units (CBU) is used increasingly in clinical applications involving ex vivo expansion. The CliniMACS instrument from Miltenyi Biotec is a current good manufacturing practice (cGMP) immunomagnetic selection system primarily designed for processing larger numbers of cells: a standard tubing set (TS) can process a maximum of 60 billion cells, while the larger capacity tubing set (LS) will handle 120 billion cells. In comparison, most CBU contain only 1-2 billion cells, raising a question regarding the optimal tubing set for CBU CD34(+) enrichment. We compared CD34(+) cell recovery and overall viability after CliniMACS processing of fresh CBU with either TS or LS. Forty-six freshly collected CBU (≤ 36 h) were processed for CD34(+) enrichment; 22 consecutive units were selected using TS and a subsequent 24 processed with LS. Cell counts and immunophenotyping were performed pre- and post-selection to assess total nucleated cells (TNC), viability and CD34(+) cell content. Two-sample t-tests of mean CD34(+) recovery and viability revealed significant differences in favor of LS (CD34(+) recovery, LS = 56%, TS = 45%, P = 0.003; viability, LS = 74%, TS = 59%, P = 0.011). Stepwise linear regression, considering pre-processing unit age, viability, TNC and CD34(+) purity, demonstrated statistically significant correlations only with the tubing set used and age of unit. For CD34(+) enrichment from fresh CBU, LS provided higher post-selection viability and more efficient recovery. In this case, a lower maximum TNC specification of TS was not predictive of better performance. The same may hold for smaller scale enrichment of other cell types with the CliniMACS instrument.

Zoledronic Acid Inhibits Aromatase Activity and Phosphorylation: Potential Mechanism for Additive Zoledronic Acid and Letrozole Drug Interaction

PubMed Central

Schech, Amanda J.; Nemieboka, Brandon E.; Brodie, Angela H.

2012-01-01

Zoledronic acid (ZA), a bisphosphonate originally indicated for use in osteoporosis, has been reported to exert a direct effect on breast cancer cells, although the mechanism of this effect is currently unknown. Data from the ABCSG-12 and ZO-FAST clinical trials suggest that treatment with the combination of ZA and aromatase inhibitors (AI) result in increased disease free survival in breast cancer patients over AI alone. To determine whether the mechanism of this combination involved inhibition of aromatase, AC-1 cells (MCF-7 human breast cancer cells transfected with an aromatase construct) were treated simultaneously with combinations of ZA and AI letrozole for 72 hours. This combination significantly increased inhibition of aromatase activity of AC-1 cells by compared to letrozole alone. Combination treatment of 1nM letrozole and 1μM and 10μM zoledronic acid resulted in an additive drug interaction on inhibiting cell viability, as measured by MTT assay. Treatment with ZA was found to inhibit phosphorylation of aromatase on serine 473. Zoledronic acid was also shown to be more effective in inhibiting cell viability in aromatase transfected AC-1 cells when compared to inhibition of cell viability observed in non-transfected MCF-7. Estradiol was able to partially rescue the effect of 1μM and 10μM ZA on cell viability following treatment for 72 hours, as shown by a shift to the right in the estradiol dose response curve. In conclusion, these results indicate that the combination of ZA and letrozole results in an additive inhibition of cell viability. Furthermore, ZA alone can inhibit aromatase activity through inhibition of serine phosphorylation events important for aromatase enzymatic activity and contributes to inhibition of cell viability. PMID:22659283

Monosodium urate monohydrate crystals inhibit osteoblast viability and function: implications for development of bone erosion in gout.

PubMed

Chhana, Ashika; Callon, Karen E; Pool, Bregina; Naot, Dorit; Watson, Maureen; Gamble, Greg D; McQueen, Fiona M; Cornish, Jillian; Dalbeth, Nicola

2011-09-01

Bone erosion is a common manifestation of chronic tophaceous gout. To investigate the effects of monosodium urate monohydrate (MSU) crystals on osteoblast viability and function. The MTT assay and flow cytometry were used to assess osteoblast cell viability in the MC3T3-E1 and ST2 osteoblast-like cell lines, and primary rat and primary human osteoblasts cultured with MSU crystals. Quantitative real-time PCR and von Kossa stained mineralised bone formation assays were used to assess the effects of MSU crystals on osteoblast differentiation using MC3T3-E1 cells. The numbers of osteoblasts and bone lining cells were quantified in bone samples from patients with gout. MSU crystals rapidly reduced viability in all cell types in a dose-dependent manner. The inhibitory effect on cell viability was independent of crystal phagocytosis and was not influenced by differing crystal length or addition of serum. Long-term culture of MC3T3-E1 cells with MSU crystals showed a reduction in mineralisation and decreased mRNA expression of genes related to osteoblast differentiation such as Runx2, Sp7 (osterix), Ibsp (bone sialoprotein), and Bglap (osteocalcin). Fewer osteoblast and lining cells were present on bone directly adjacent to gouty tophus than bone unaffected by tophus in patients with gout. MSU crystals have profound inhibitory effects on osteoblast viability and differentiation. These data suggest that bone erosion in gout occurs at the tophus-bone interface through alteration of physiological bone turnover, with both excessive osteoclast formation, and reduced osteoblast differentiation from mesenchymal stem cells.

Tumor microenvironment is multifaceted.

PubMed

Sautès-Fridman, Catherine; Cherfils-Vicini, Julien; Damotte, Diane; Fisson, Sylvain; Fridman, Wolf Hervé; Cremer, Isabelle; Dieu-Nosjean, Marie-Caroline

2011-03-01

Cancer initiation, progression, and invasion occur in a complex and dynamic microenvironment which depends on the hosts and sites where tumors develop. Tumors arising in mucosal tissues may progress in an inflammatory context linked to local viral and/or bacterial infections. At the opposite, tumors developing in immunoprivileged sites are protected from microorganisms and grow in an immunosuppressive environment. In the present review, we summarize and present our recent data on the influence of infectious context and immune cell infiltration organization in human Non-Small Cell Lung Cancers (NSCLC) progression. We show that stimulation of tumor cells by TLR for viral ssRNA, such as TLR7/8, or bacteria, such as TLR4, promotes cell survival and induces chemoresistance. On the opposite, stimulation by TLR3, receptor for double-stranded viral RNA, decreases tumor cell viability and induces chemosensitivity in some lung tumor cell lines. Since fresh lung tumor cells exhibit a gene expression profile characteristic of TLR-stimulated lung tumor cell lines, we suspect that viral and bacterial influence may not only act on the host immune system but also directly on tumor growth and sensitivity to chemotherapy. The stroma of NSCLC contains tertiary lymphoid structures (or Tumor-induced Bronchus-Associated Lymphoid Tissues (Ti-BALT)) with mature DC, follicular DC, and T and B cells. Two subsets of immature DC, Langerhans cells (LC) and interstitial DC (intDC), were detected in the tumor nests and the stroma, respectively. Here, we show that the densities of the three DC subsets, mature DC, LC, and intDC, are highly predictive of disease-specific survival in a series of 74 early-stage NSCLC patients. We hypothesize that the mature DC may derive from local activation and migration of the immature DC--and especially LC which contact the tumor cells--to the tertiary lymphoid structures, after sampling and processing of the tumor antigens. In view of the prominent role of DC in the immune response, we suggest that the microenvironment of early-stage NSCLC may allow the in situ activation of the adaptive response. Finally, we find that the eyes or brain of mice with growing B cell lymphoma are infiltrated with T cells and that the cytokines produced ex vivo by the tumoral tissues have an impaired Th1 cytokine profile. Our work illustrates that the host and external tumor microenvironments are multifaceted and strongly influence tumor progression and anti-tumor immune responses.

Influence of electrospun scaffolds prepared from distinct polymers on proliferation and viability of endothelial cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matveeva, V. G., E-mail: matveeva-vg@mail.ru; Antonova, L. V., E-mail: antonova.la@mail.ru; Velikanova, E. A.

We compared electrospun nonwoven scaffolds from polylactic acid (PLA), polycaprolactone (PCL), and polyhydroxybutyrate/valerate (PHBV)/polycaprolactone (PHBV/PCL). The surface of PHBV/PCL and PCL scaffolds was highly porous and consisted of randomly distributed fibers, whilst the surface of PLA scaffolds consisted of thin straight fibers, which located more sparsely, forming large pores. Culture of EA.hy 926 endothelial cells on these scaffolds during 7 days and further fluorescent microscopy demonstrated that the surface of PHBV/PCL scaffolds was most favorable for efficient adhesion, proliferation, and viability of endothelial cells. The lowest proliferation rate and cell viability were detected on PLA scaffolds. Therefore, PHBV/PCL electrospun nonwovenmore » scaffolds demonstrated the best results regarding endothelial cell proliferation and viability as compared to PCL and PLA scaffolds.« less

Phospholipids Trigger Cryptococcus neoformans Capsular Enlargement during Interactions with Amoebae and Macrophages

PubMed Central

Chrisman, Cara J.; Albuquerque, Patricia; Guimaraes, Allan J.; Nieves, Edward; Casadevall, Arturo

2011-01-01

A remarkable aspect of the interaction of Cryptococcus neoformans with mammalian hosts is a consistent increase in capsule volume. Given that many aspects of the interaction of C. neoformans with macrophages are also observed with amoebae, we hypothesized that the capsule enlargement phenomenon also had a protozoan parallel. Incubation of C. neoformans with Acanthamoeba castellanii resulted in C. neoformans capsular enlargement. The phenomenon required contact between fungal and protozoan cells but did not require amoeba viability. Analysis of amoebae extracts showed that the likely stimuli for capsule enlargement were protozoan polar lipids. Extracts from macrophages and mammalian serum also triggered cryptococcal capsular enlargement. C. neoformans capsule enlargement required expression of fungal phospholipase B, but not phospholipase C. Purified phospholipids, in particular, phosphatidylcholine, and derived molecules triggered capsular enlargement with the subsequent formation of giant cells. These results implicate phospholipids as a trigger for both C. neoformans capsule enlargement in vivo and exopolysaccharide production. The observation that the incubation of C. neoformans with phospholipids led to the formation of giant cells provides the means to generate these enigmatic cells in vitro. Protozoan- or mammalian-derived polar lipids could represent a danger signal for C. neoformans that triggers capsular enlargement as a non-specific defense mechanism against potential predatory cells. Hence, phospholipids are the first host-derived molecules identified to trigger capsular enlargement. The parallels apparent in the capsular response of C. neoformans to both amoebae and macrophages provide additional support for the notion that certain aspects of cryptococcal virulence emerged as a consequence of environmental interactions with other microorganisms such as protists. PMID:21637814

S-Layer Protein Mediates the Stimulatory Effect of Lactobacillus helveticus MIMLh5 on Innate Immunity

PubMed Central

Taverniti, Valentina; Stuknyte, Milda; Minuzzo, Mario; Arioli, Stefania; De Noni, Ivano; Scabiosi, Christian; Cordova, Zuzet Martinez; Junttila, Ilkka; Hämäläinen, Sanna; Turpeinen, Hannu; Mora, Diego; Karp, Matti; Pesu, Marko

2013-01-01

The ability to positively affect host health through the modulation of the immune response is a feature of increasing importance in measuring the probiotic potential of a bacterial strain. However, the identities of the bacterial cell components involved in cross talk with immune cells remain elusive. In this study, we characterized the dairy strain Lactobacillus helveticus MIMLh5 and its surface-layer protein (SlpA) using in vitro and ex vivo analyses. We found that MIMLh5 and SlpA exert anti-inflammatory effects by reducing the activation of NF-κB on the intestinal epithelial Caco-2 cell line. On the contrary, MIMLh5 and SlpA act as stimulators of the innate immune system by triggering the expression of proinflammatory factors tumor necrosis factor alpha and COX-2 in the human macrophage cell line U937 via recognition through Toll-like receptor 2. In the same experiments, SlpA protein did not affect the expression of the anti-inflammatory cytokine interleukin-10. A similar response was observed following stimulation of macrophages isolated from mouse bone marrow or the peritoneal cavity. These results suggest that SlpA plays a major role in mediating bacterial immune-stimulating activity, which could help to induce the host's defenses against and responses toward infections. This study supports the concept that the viability of bacterial cells is not always essential to exert immunomodulatory effects, thus permitting the development of safer therapies for the treatment of specific diseases according to a paraprobiotic intervention. PMID:23220964

CpG oligodeoxynucleotide induces apoptosis and cell cycle arrest in A20 lymphoma cells via TLR9-mediated pathways.

PubMed

Qi, Xu-Feng; Zheng, Li; Kim, Cheol-Su; Lee, Kyu-Jae; Kim, Dong-Heui; Cai, Dong-Qing; Qin, Jun-Wen; Yu, Yan-Hong; Wu, Zheng; Kim, Soo-Ki

2013-07-01

Recent studies have suggested that the anti-cancer activity of CpG-oligodeoxynucleotides (CpG-ODNs) is owing to their immunomodulatory effects in tumor-bearing host. The purpose of this study is to investigate the directly cytotoxic activity of KSK-CpG, a novel CpG-ODN with an alternative CpG motif, against A20 and EL4 lymphoma cells in comparison with previously used murine CpG motif (1826-CpG). To evaluate the potential cytotoxic effects of KSK-CpG on lymphoma cells, cell viability assay, confocal microscopy, flow cytometry, DNA fragmentation, Western blotting, and reverse transcription-polymerase chain reaction (RT-PCR) analysis were used. We found that KSK-CpG induced direct cytotoxicity in A20 lymphoma cells, but not in EL4 lymphoma cells, at least in part via TLR9-mediated pathways. Apoptotic cell death was demonstrated to play an important role in CpG-ODNs-induced cytotoxicity. In addition, both mitochondrial membrane potential decrease and G1-phase arrest were involved in KSK-CpG-induced apoptosis in A20 cells. The activities of apoptotic molecules such as caspase-3, PARP, and Bax were increased, but the activation of p27 Kip1 and ERK were decreased in KSK-CpG-treated A20 cells. Furthermore, autocrine IFN-γ partially contributed to apoptotic cell death in KSK-CpG-treated A20 cells. Collectively, our findings suggest that KSK-CpG induces apoptotic cell death in A20 lymphoma cells at least in part by inducing G1-phase arrest and autocrine IFN-γ via increasing TLR9 expression, without the need for immune system of tumor-bearing host. This new understanding supports the development of TLR9-targeted therapy with CpG-ODN as a direct therapeutic agent for treating B lymphoma. Copyright © 2013 Elsevier Ltd. All rights reserved.

Comparative evaluation of the isolation and quantification of stem cells derived from dental pulp and periodontal ligament of a permanent tooth and to assess their viability and proliferation on a platelet-rich fibrin scaffold

PubMed Central

Khurana, Rohit; Kudva, Praveen Bhasker; Husain, Syed Yawer

2017-01-01

Background: The present study aims to comparatively evaluate the isolation and quantification of stem cells derived from dental pulp and periodontal ligament of a permanent tooth and to assess their viability and proliferation on a platelet-rich fibrin (PRF) scaffold. Materials and Methods: A total of 15 systemically healthy individuals between the age group of 15–25 years requiring third molar or orthodontic premolar extractions. Teeth were extracted atraumatically and transported to the laboratory. Stem cells were isolated from dental pulp and periodontal ligament. After attaining more than 90% confluency by the 7th day, these cells were tested for their viability and characterization. Stem cells were also incubated with PRF and viability was assessed on the 7th day. Results: The mean number of cell for dental pulp stem cells (DPSCs) and periodontal ligament stem cell (PDLSC) was statistically insignificant (P > 0.05). The mean live cell viability was compared between DPSC (98.07%) and PDLSC (98%). Both DPSC and PDLSC showed a high percentage of expression of CD73 markers, 30.40% and 29.80%, respectively. However, DPSCs and PDLSCs lacked expression of CD34 expressing only 3.47% and 3.53%, respectively. PRF membrane as a scaffold exhibited no cytotoxic effects on DPCS's or PDLSC's. The cell viability of cells cultured with PRF was statistically insignificant (P > 0.05) when compared to the cells cultured with culture media. Conclusion: The study thus indicates that dental pulp and periodontal ligament are both rich sources of mesenchymal stem cells and can be successfully used for obtaining stem cells. PRF exhibits no cytotoxic effects on the cells and can be used in conjunction with dental stem cells. PMID:29386795

Effect of low-level laser irradiation on proliferation and viability of human dental pulp stem cells.

PubMed

Zaccara, Ivana Maria; Ginani, Fernanda; Mota-Filho, Haroldo Gurgel; Henriques, Águida Cristina Gomes; Barboza, Carlos Augusto Galvão

2015-12-01

A positive effect of low-level laser irradiation (LLLI) on the proliferation of some cell types has been observed, but little is known about its effect on dental pulp stem cells (DPSCs). The aim of this study was to identify the lowest energy density able to promote the proliferation of DPSCs and to maintain cell viability. Human DPSCs were isolated from two healthy third molars. In the third passage, the cells were irradiated or not (control) with an InGaAlP diode laser at 0 and 48 h using two different energy densities (0.5 and 1.0 J/cm²). Cell proliferation and viability and mitochondrial activity were evaluated at intervals of 24, 48, 72, and 96 h after the first laser application. Apoptosis- and cell cycle-related events were analyzed by flow cytometry. The group irradiated with an energy density of 1.0 J/cm² exhibited an increase of cell proliferation, with a statistically significant difference (p < 0.05) compared to the control group at 72 and 96 h. No significant changes in cell viability were observed throughout the experiment. The distribution of cells in the cell cycle phases was consistent with proliferating cells in all three groups. We concluded that LLLI, particularly a dose of 1.0 J/cm², contributed to the growth of DPSCs and maintenance of its viability. This fact indicates this therapy to be an important future tool for tissue engineering and regenerative medicine involving stem cells.

Agglomeration, sedimentation, and cellular toxicity of alumina nanoparticles in cell culture medium

NASA Astrophysics Data System (ADS)

Yoon, Dokyung; Woo, Daekwang; Kim, Jung Heon; Kim, Moon Ki; Kim, Taesung; Hwang, Eung-Soo; Baik, Seunghyun

2011-06-01

The cytotoxicity of alumina nanoparticles (NPs) was investigated for a wide range of concentration (25-200 μg/mL) and incubation time (0-72 h) using floating cells (THP-1) and adherent cells (J774A.1, A549, and 293). Alumina NPs were gradually agglomerated over time although a significant portion of sedimentation occurred at the early stage within 6 h. A decrease of the viability was found in floating (THP-1) and adherent (J774A.1 and A549) cells in a dose-dependent manner. However, the time-dependent decrease in cell viability was observed only in adherent cells (J774A.1 and A549), which is predominantly related with the sedimentation of alumina NPs in cell culture medium. The uptake of alumina NPs in macrophages and an increased cell-to-cell adhesion in adherent cells were observed. There was no significant change in the viability of 293 cells. This in vitro test suggests that the agglomeration and sedimentation of alumina NPs affected cellular viability depending on cell types such as monocytes (THP-1), macrophages (J774A.1), lung carcinoma cells (A549), and embryonic kidney cells (293).

Effect of fluoride on the cell viability, cell organelle potential, and photosynthetic capacity of freshwater and soil algae.

PubMed

Chae, Yooeun; Kim, Dokyung; An, Youn-Joo

2016-12-01

Although fluoride occurs naturally in the environment, excessive amounts of fluoride in freshwater and terrestrial ecosystems can be harmful. We evaluated the toxicity of fluoride compounds on the growth, viability, and photosynthetic capacity of freshwater (Chlamydomonas reinhardtii and Pseudokirchneriella subcapitata) and terrestrial (Chlorococcum infusionum) algae. To measure algal growth inhibition, a flow cytometric method was adopted (i.e., cell size, granularity, and auto-fluorescence measurements), and algal yield was calculated to assess cell viability. Rhodamine123 and fluorescein diacetate were used to evaluate mitochondrial membrane potential (MMA, ΔΨ m ) and cell permeability. Nine parameters related to the photosynthetic capacity of algae were also evaluated. The results indicated that high concentrations of fluoride compounds affected cell viability, cell organelle potential, and photosynthetic functions. The cell viability measurements of the three algal species decreased, but apoptosis was only observed in C. infusionum. The MMA (ΔΨ m ) of cells exposed to fluoride varied among species, and the cell permeability of the three species generally decreased. The decrease in the photosynthetic activity of algae may be attributable to the combination of fluoride ions (F - ) with magnesium ions (Mg 2+ ) in chlorophyll. Our results therefore provide strong evidence for the potential risks of fluoride compounds to microflora and microfauna in freshwater and terrestrial ecosystems. Copyright © 2016 Elsevier Ltd. All rights reserved.

Viability and Virulence of Experimentally Stressed Nonculturable Salmonella typhimurium

PubMed Central

Caro, Audrey; Got, Patrice; Lesne, Jean; Binard, Sylvie; Baleux, Bernard

1999-01-01

Maintenance of pathogenicity of viable but nonculturable Salmonella typhimurium cells experimentally stressed with UV-C and seawater, was investigated relative to the viability level of the cellular population. Pathogenicity, tested in a mouse model, was lost concomitantly with culturability, whereas cell viability remained undamaged, as determined by respiratory activity and cytoplasmic membrane and genomic integrities. PMID:10388726

Curcumin and Viscum album Extract Decrease Proliferation and Cell Viability of Soft-Tissue Sarcoma Cells: An In Vitro Analysis of Eight Cell Lines Using Real-Time Monitoring and Colorimetric Assays.

PubMed

Harati, K; Behr, B; Daigeler, A; Hirsch, T; Jacobsen, F; Renner, M; Harati, A; Wallner, C; Lehnhardt, M; Becerikli, M

2017-01-01

The cytostatic effects of the polyphenol curcumin and Viscum album extract (VAE) were assessed in soft-tissue sarcoma (STS) cells. Eight human STS cell lines were used: fibrosarcoma (HT1080), liposarcoma (SW872, T778, MLS-402), synovial sarcoma (SW982, SYO1, 1273), and malignant fibrous histiocytoma (U2197). Primary human fibroblasts served as control cells. Cell proliferation, viability, and cell index (CI) were analyzed by BrdU assay, MTT assay, and real-time cell analysis (RTCA). As indicated by BrdU and MTT, curcumin significantly decreased the cell proliferation of five cell lines (HT1080, SW872, SYO1, 1273, and U2197) and the viability of two cell lines (SW872 and SW982). VAE led to significant decreases of proliferation in eight cell lines (HT1080, SW872, T778, MLS-402, SW982, SYO1, 1293, and U2197) and reduced viability in seven STS lines (HT1080, SW872, T778, MLS-402, SW982, SYO1, and 1273). As indicated by RTCA for 160 h, curcumin decreased the CI of all synovial sarcoma cell lines as well as T778 and HT1080. VAE diminished the CI in most of the synovial sarcoma (SW982, SYO1) and liposarcoma (SW872, T778) cell lines as well as HT1080. Primary fibroblasts were not affected adversely by the two compounds in RTCA. Curcumin and VAE can inhibit the proliferation and viability of STS cells.

Dragon's Blood Sap (Croton Lechleri) As Storage Medium For Avulsed Teeth: In Vitro Study Of Cell Viability.

PubMed

Martins, Christine Men; Hamanaka, Elizane Ferreira; Hoshida, Thayse Yumi; Sell, Ana Maria; Hidalgo, Mirian Marubayashi; Silveira, Catarina Soares; Poi, Wilson Roberto

2016-01-01

Tooth replantation success depends on the condition of cementum periodontal ligament after tooth avulsion; which is influenced by storage medium. The dragon's blood (Croton lechleri) sap has been suggested as a promising medium because it supports collagen formation and exhibits healing, anti-inflammatory and antimicrobial properties. Thus, the aim of this study was to evaluate the efficacy of dragon's blood sap as a storage medium for avulsed teeth through evaluation of functional and metabolic cell viability. This in vitro study compared the efficacy of different storage media to maintain the viability of human peripheral blood mononuclear and periodontal ligament cells. A 10% dragon's blood sap was tested while PBS was selected as its control. Ultra pasteurized whole milk was used for comparison as a commonly used storage medium. DMEM and distilled water were the positive and negative controls, respectively. The viability was assessed through trypan blue exclusion test and colorimetric MTT assay after 1, 3, 6, 10 and 24 h of incubation. The dragon's blood sap showed promising results due to its considerable maintenance of cell viability. For trypan blue test, the dragon's blood sap was similar to milk (p<0.05) and both presented the highest viability values. For MTT, the dragon's blood sap showed better results than all storage media, even better than milk (p<0.05). It was concluded that the dragon's blood sap was as effective as milk, the gold standard for storage medium. The experimental sap preserved the membrane of all cells and the functional viability of periodontal ligament cells.

The Effects of Oxygen Level and Glucose Concentration on the Metabolism of Porcine TMJ Disc Cells

PubMed Central

Cisewski, Sarah E.; Zhang, Lixia; Kuo, Jonathan; Wright, Gregory J.; Wu, Yongren; Kern, Michael J.; Yao, Hai

2015-01-01

Objective To determine the combined effect of oxygen level and glucose concentration on cell viability, ATP production, and matrix synthesis of temporomandibular joint (TMJ) disc cells. Design TMJ disc cells were isolated from pigs aged 6-8 months and cultured in a monolayer. Cell cultures were preconditioned for 48 hours with 0, 1.5, 5, or 25mM glucose DMEM under 1%, 5%, 10%, or 21% O2 level, respectively. The cell viability was measured using the WST-1 assay. ATP production was determined using the Luciferin-Luciferase assay. Collagen and proteoglycan synthesis were determined by measuring the incorporation of [2, 3-3H]proline and [35S]sulfate into the cells, respectively. Results TMJ disc cell viability significantly decreased (P<0.0001) without glucose. With glucose present, decreased oxygen levels significantly increased viability (P<0.0001), while a decrease in glucose concentration significantly decreased viability (P<0.0001). With glucose present, decreasing oxygen levels significantly reduced ATP production (P<0.0001) and matrix synthesis (P<0.0001). A decreased glucose concentration significantly decreased collagen synthesis (P<0.0001). The interaction between glucose and oxygen was significant in regards to cell viability (P<0.0001), ATP production (P=0.00015), and collagen (P=0.0002) and proteoglycan synthesis (P<0.0001). Conclusions Although both glucose and oxygen are important, glucose is the limiting nutrient for TMJ disc cell survival. At low oxygen levels, the production of ATP, collagen, and proteoglycan are severely inhibited. These results suggest that steeper nutrient gradients may exist in the TMJ disc and it may be vulnerable to pathological events that impede nutrient supply. PMID:26033165

The effects of oxygen level and glucose concentration on the metabolism of porcine TMJ disc cells.

PubMed

Cisewski, S E; Zhang, L; Kuo, J; Wright, G J; Wu, Y; Kern, M J; Yao, H

2015-10-01

To determine the combined effect of oxygen level and glucose concentration on cell viability, ATP production, and matrix synthesis of temporomandibular joint (TMJ) disc cells. TMJ disc cells were isolated from pigs aged 6-8 months and cultured in a monolayer. Cell cultures were preconditioned for 48 h with 0, 1.5, 5, or 25 mM glucose DMEM under 1%, 5%, 10%, or 21% O2 level, respectively. The cell viability was measured using the WST-1 assay. ATP production was determined using the Luciferin-Luciferase assay. Collagen and proteoglycan synthesis were determined by measuring the incorporation of [2, 3-(3)H] proline and [(35)S] sulfate into the cells, respectively. TMJ disc cell viability significantly decreased (P < 0.0001) without glucose. With glucose present, decreased oxygen levels significantly increased viability (P < 0.0001), while a decrease in glucose concentration significantly decreased viability (P < 0.0001). With glucose present, decreasing oxygen levels significantly reduced ATP production (P < 0.0001) and matrix synthesis (P < 0.0001). A decreased glucose concentration significantly decreased collagen synthesis (P < 0.0001). The interaction between glucose and oxygen was significant in regards to cell viability (P < 0.0001), ATP production (P = 0.00015), and collagen (P = 0.0002) and proteoglycan synthesis (P < 0.0001). Although both glucose and oxygen are important, glucose is the limiting nutrient for TMJ disc cell survival. At low oxygen levels, the production of ATP, collagen, and proteoglycan are severely inhibited. These results suggest that steeper nutrient gradients may exist in the TMJ disc and it may be vulnerable to pathological events that impede nutrient supply. Copyright © 2015 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Molecular Viability Testing of UV-Inactivated Bacteria.

PubMed

Weigel, Kris M; Nguyen, Felicia K; Kearney, Moira R; Meschke, John S; Cangelosi, Gerard A

2017-05-15

PCR is effective in detecting bacterial DNA in samples, but it is unable to differentiate viable bacteria from inactivated cells or free DNA fragments. New PCR-based analytical strategies have been developed to address this limitation. Molecular viability testing (MVT) correlates bacterial viability with the ability to rapidly synthesize species-specific rRNA precursors (pre-rRNA) in response to brief nutritional stimulation. Previous studies demonstrated that MVT can assess bacterial inactivation by chlorine, serum, and low-temperature pasteurization. Here, we demonstrate that MVT can detect inactivation of Escherichia coli , Aeromonas hydrophila , and Enterococcus faecalis cells by UV irradiation. Some UV-inactivated E. coli cells transiently retained the ability to synthesize pre-rRNA postirradiation (generating false-positive MVT results), but this activity ceased within 1 h following UV exposure. Viable but transiently undetectable (by culture) E. coli cells were consistently detected by MVT. An alternative viability testing method, viability PCR (vPCR), correlates viability with cell envelope integrity. This method did not distinguish viable bacteria from UV-inactivated bacteria under some conditions, indicating that the inactivated cells retained intact cell envelopes. MVT holds promise as a means to rapidly assess microbial inactivation by UV treatment. IMPORTANCE UV irradiation is increasingly being used to disinfect water, food, and other materials for human use. Confirming the effectiveness of UV disinfection remains a challenging task. In particular, microbiological methods that rely on rapid detection of microbial DNA can yield misleading results, due to the detection of remnant DNA associated with dead microbial cells. This report describes a novel method that rapidly distinguishes living microbial cells from dead microbial cells after UV disinfection. Copyright © 2017 American Society for Microbiology.

MiR-34a Inhibits Viability and Invasion of Human Papillomavirus-Positive Cervical Cancer Cells by Targeting E2F3 and Regulating Survivin.

PubMed

Geng, Dianzhong; Song, Xiaohua; Ning, Fangling; Song, Qianhua; Yin, Honghua

2015-05-01

Previous studies confirmed that high-risk human papillomavirus (HR-HPV) infection is a risk factor of cervical cancer, and the infection was associated with significantly reduced miR-34a expression during carcinogenesis. However, the downstream targets of miR-34a and their roles are still not well understood. This study explored the regulative role of miR-34a on E2F3 and survivin expression and the viability and invasion of HPV-positive cervical cancer cells. MiR-34a and survivin expression in 56 cases of HR-HPV-positive patients, 28 cases of HR-HPV-negative patients, and 28 normal cases without HR-HPV infections were measured. Human papillomavirus-18-positive HeLa cervical cancer cells and HPV-16-positive SiHa cells were used to explore the effect of miR-34a on cell viability and invasion. The molecular target of miR-34a was also explored in cervical cancer cells. The results showed that miR-34a overexpression could inhibit HPV-positive cancer cell viability, whereas its downregulation promoted cell viability. E2F3 is a direct target of miR-34a in HPV-positive cervical cancer cells. By targeting E2F3, miR-34a could regulate the expression of survivin. Thus, through regulating E2F3 and survivin, miR-34a could reduce the viability and invasion of HPV-positive cervical cancer cells. This study confirmed a novel miR-34a-E2F3-survivin axis in the tumor suppressor role of miR-34a in cervical cancer.

The type and composition of alginate and hyaluronic-based hydrogels influence the viability of stem cells of the apical papilla.

PubMed

Lambricht, Laure; De Berdt, Pauline; Vanacker, Julie; Leprince, Julian; Diogenes, Anibal; Goldansaz, Hadi; Bouzin, Caroline; Préat, Véronique; Dupont-Gillain, Christine; des Rieux, Anne

2014-12-01

The goal of the present work was to evaluate in vitro and in vivo the influence of various types and compositions of natural hydrogels on the viability and metabolic activity of SCAPs. Two alginate, three hyaluronic-based (Corgel™) hydrogel formulations and Matrigel were characterized for their mechanical, surface and microstructure properties using rheology, X-ray photoelectron spectroscopy and scanning electron microscopy, respectively. A characterized SCAP cell line (RP89 cells) was encapsulated in the different experimental hydrogel formulations. Cells were cultured in vitro, or implanted in cyclosporine treated mice. In vitro cell viability was evaluated using a Live/Dead assay and in vitro cellular metabolic activity was evaluated with a MTS assay. In vivo cell apoptosis was evaluated by a TUNEL test and RP89 cells were identified by human mitochondria immunostaining. Hydrogel composition influenced their mechanical and surface properties, and their microstructure. In vitro cell viability was above 80% after 2 days but decreased significantly after 7 days (60-40%). Viability at day 7 was the highest in Matrigel (70%) and then in Corgel 1.5 (60%). Metabolic activity increased over time in all the hydrogels, excepted in alginate SLM. SCAPs survived after 1 week in vivo with low apoptosis (<1%). The highest number of RP89 cells was found in Corgel 5.5 (140cells/mm(2)). Collectively, these data demonstrate that SCAP viability was directly modulated by hydrogel composition and suggest that a commercially available hyaluronic acid-based formulation might be a suitable delivery vehicle for SCAP-based dental pulp regeneration strategies. Copyright © 2014 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Study of the stability of packaging and storage conditions of human mesenchymal stem cell for intra-arterial clinical application in patient with critical limb ischemia.

PubMed

Gálvez-Martín, Patricia; Hmadcha, Abdelkrim; Soria, Bernat; Calpena-Campmany, Ana C; Clares-Naveros, Beatriz

2014-04-01

Critical limb ischemia (CLI) is associated with significant morbidity and mortality. In this study, we developed and characterized an intra-arterial cell suspension containing human mesenchymal stem cells (hMSCs) for the treatment of CLI. Equally, the stability of cells was studied in order to evaluate the optimal conditions of storage that guarantee the viability from cell processing to the administration phase. Effects of various factors, including excipients, storage temperature and time were evaluated to analyze the survival of hMSCs in the finished medicinal product. The viability of hMSCs in different packaging media was studied for 60 h at 4 °C. The best medium to maintain hMSCs viability was then selected to test storage conditions (4, 8, 25 and 37 °C; 60 h). The results showed that at 4 °C the viability was maintained above 80% for 48 h, at 8 °C decreased slightly, whereas at room temperature and 37 °C decreased drastically. Its biocompatibility was assessed by cell morphology and cell viability assays. During stability study, the stored cells did not show any change in their phenotypic or genotypic characteristics and physicochemical properties remained constant, the ability to differentiate into adipocytes and osteocytes and sterility requirements were also unaltered. Finally, our paper proposes a packing media composed of albumin 20%, glucose 5% and Ringer's lactate at a concentration of 1×10(6) cells/mL, which must be stored at 4 °C as the most suitable to maintain cell viability (>80%) and without altering their characteristics for more than 48 h. Copyright © 2013 Elsevier B.V. All rights reserved.

Temperature fluctuations during deep temperature cryopreservation reduce PBMC recovery, viability and T-cell function.

PubMed

Germann, Anja; Oh, Young-Joo; Schmidt, Tomm; Schön, Uwe; Zimmermann, Heiko; von Briesen, Hagen

2013-10-01

The ability to analyze cryopreserved peripheral blood mononuclear cell (PBMC) from biobanks for antigen-specific immunity is necessary to evaluate response to immune-based therapies. To ensure comparable assay results, collaborative research in multicenter trials needs reliable and reproducible cryopreservation that maintains cell viability and functionality. A standardized cryopreservation procedure is comprised of not only sample collection, preparation and freezing but also low temperature storage in liquid nitrogen without any temperature fluctuations, to avoid cell damage. Therefore, we have developed a storage approach to minimize suboptimal storage conditions in order to maximize cell viability, recovery and T-cell functionality. We compared the influence of repeated temperature fluctuations on cell health from sample storage, sample sorting and removal in comparison to sample storage without temperature rises. We found that cyclical temperature shifts during low temperature storage reduce cell viability, recovery and immune response against specific-antigens. We showed that samples handled under a protective hood system, to avoid or minimize such repeated temperature rises, have comparable cell viability and cell recovery rates to samples stored without any temperature fluctuations. Also T-cell functionality could be considerably increased with the use of the protective hood system compared to sample handling without such a protection system. This data suggests that the impact of temperature fluctuation on cell integrity should be carefully considered in future clinical vaccine trials and consideration should be given to optimal sample storage conditions. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

Cell viability, reactive oxygen species, apoptosis, and necrosis in myoblast cultures exposed to low-level infrared laser.

PubMed

Alexsandra da Silva Neto Trajano, Larissa; da Silva, Camila Luna; de Carvalho, Simone Nunes; Cortez, Erika; Mencalha, André Luiz; de Souza da Fonseca, Adenilson; Stumbo, Ana Carolina

2016-07-01

Low-level infrared laser is considered safe and effective for treatment of muscle injuries. However, the mechanism involved on beneficial effects of laser therapy are not understood. The aim was to evaluate cell viability, reactive oxygen species, apoptosis, and necrosis in myoblast cultures exposed to low-level infrared laser at therapeutic fluences. C2C12 myoblast cultures at different (2 and 10 %) fetal bovine serum (FBS) concentrations were exposed to low-level infrared laser (808 nm, 100 mW) at different fluences (10, 35, and 70 J/cm(2)) and evaluated after 24, 48, and 72 h. Cell viability was evaluated by WST-1 assay; reactive oxygen species (ROS), apoptosis, and necrosis were evaluated by flow cytometry. Cell viability was decreased atthe lowest FBS concentration. Laser exposure increased the cell viability in myoblast cultures at 2 % FBS after 48 and 72 h, but no significant increase in ROS was observed. Apoptosis was decreased at the higher fluence and necrosis was increased at lower fluence in myoblast cultures after 24 h of laser exposure at 2 % FBS. No laser-induced alterations were obtained at 10 % FBS. Results show that level of reactive oxygen species is not altered, at least to those evaluated in this study, but low-level infrared laser exposure affects cell viability, apoptosis, and necrosis in myoblast cultures depending on laser fluence and physiologic conditions of cells.

Limitations in the Use of Fluorescein Diacetate/Propidium Iodide (FDA/PI) and Cell Permeable Nucleic Acid Stains for Viability Measurements of Isolated Islets of Langerhans.

PubMed

Boyd, Vinc; Cholewa, Olivia Maria; Papas, Klearchos K

2008-03-01

BACKGROUND: A review of current literature shows that the combined use of the cell permeable esterase-substrate fluorescein diacetate (FDA) and the cell impermeant nucleic acid stain propidium iodide (PI) to be one of the most common fluorescence-based methods to assess the viability of isolated islets of Langerhans, and it is currently used for islet product release prior to transplantation in humans. However, results from this assay do not correlate with islet viability and function or islet transplantation success in animals or humans (Eckhard et al. 2004; Ricordi et al. 2001). This may be in part attributed to considerable differences as well as discrepancies in the use of these reagents on islets. We critically surveyed the literature and evaluated the impact of a number of variables associated with the use of FDA/PI to determine their reliability in assessing islet cell viability. In addition, we evaluated other fluorescent stains, such as SYTO(R)13, SYTO(R)24 and SYBR(R)14 as possible alternatives to FDA. RESULTS: We found that the stability of stains in storage and stock solutions, the number of islets stained, concentration of stains, staining incubation time, the buffer/media used, and the method of examining islets were significant in the final scoring of viability. For archival file photos, the exposure time and camera/software settings can also impact interpretation of viability. Although our results show that FDA does detect intracellular esterase activity and staining with PI does assess cell membrane integrity, the results obtained from using these stains did not correlate directly with expected islet function and viability per transplantation into diabetic athymic nude mice (Papas et al. 2007). In addition, the use of two nucleic acid stains, such as SYTO(R)13 and PI, for live/dead scoring exhibited staining anomalies which limit their accuracy in assessing islet viability. CONCLUSIONS: From a review of the literature and from our observations on the impact of reagent handling and various staining and imaging parameters used to visually evaluate islets, consistent interpretation of islet cell membrane integrity and viability is dependent upon a number of factors. We discuss the utility and limitations of these reagents in evaluating islet cell membrane integrity and viability.

Limitations in the Use of Fluorescein Diacetate/Propidium Iodide (FDA/PI) and Cell Permeable Nucleic Acid Stains for Viability Measurements of Isolated Islets of Langerhans

PubMed Central

Boyd, Vinc; Cholewa, Olivia Maria; Papas, Klearchos K.

2010-01-01

Background A review of current literature shows that the combined use of the cell permeable esterase-substrate fluorescein diacetate (FDA) and the cell impermeant nucleic acid stain propidium iodide (PI) to be one of the most common fluorescence-based methods to assess the viability of isolated islets of Langerhans, and it is currently used for islet product release prior to transplantation in humans. However, results from this assay do not correlate with islet viability and function or islet transplantation success in animals or humans (Eckhard et al. 2004; Ricordi et al. 2001). This may be in part attributed to considerable differences as well as discrepancies in the use of these reagents on islets. We critically surveyed the literature and evaluated the impact of a number of variables associated with the use of FDA/PI to determine their reliability in assessing islet cell viability. In addition, we evaluated other fluorescent stains, such as SYTO®13, SYTO®24 and SYBR®14 as possible alternatives to FDA. Results We found that the stability of stains in storage and stock solutions, the number of islets stained, concentration of stains, staining incubation time, the buffer/media used, and the method of examining islets were significant in the final scoring of viability. For archival file photos, the exposure time and camera/software settings can also impact interpretation of viability. Although our results show that FDA does detect intracellular esterase activity and staining with PI does assess cell membrane integrity, the results obtained from using these stains did not correlate directly with expected islet function and viability per transplantation into diabetic athymic nude mice (Papas et al. 2007). In addition, the use of two nucleic acid stains, such as SYTO®13 and PI, for live/dead scoring exhibited staining anomalies which limit their accuracy in assessing islet viability. Conclusions From a review of the literature and from our observations on the impact of reagent handling and various staining and imaging parameters used to visually evaluate islets, consistent interpretation of islet cell membrane integrity and viability is dependent upon a number of factors. We discuss the utility and limitations of these reagents in evaluating islet cell membrane integrity and viability. PMID:20814586

Characterization of the host-guest complex of a curcumin analog with β-cyclodextrin and β-cyclodextrin-gemini surfactant and evaluation of its anticancer activity.

PubMed

Poorghorban, Masoomeh; Das, Umashankar; Alaidi, Osama; Chitanda, Jackson M; Michel, Deborah; Dimmock, Jonathan; Verrall, Ronald; Grochulski, Pawel; Badea, Ildiko

2015-01-01

Curcumin analogs, including the novel compound NC 2067, are potent cytotoxic agents that suffer from poor solubility, and hence, low bioavailability. Cyclodextrin-based carriers can be used to encapsulate such agents. In order to understand the interaction between the two molecules, the physicochemical properties of the host-guest complexes of NC 2067 with β-cyclodextrin (CD) or β-cyclodextrin-gemini surfactant (CDgemini surfactant) were investigated for the first time. Moreover, possible supramolecular structures were examined in order to aid the development of new drug delivery systems. Furthermore, the in vitro anticancer activity of the complex of NC 2067 with CDgemini surfactant nanoparticles was demonstrated in the A375 melanoma cell line. Physicochemical properties of the complexes formed of NC 2067 with CD or CDgemini surfactant were investigated by synchrotron-based powder X-ray diffraction, Fourier-transform infrared spectroscopy, and thermogravimetric analysis. Synchrotron-based small- and wide-angle X-ray scattering and size measurements were employed to assess the supramolecular morphology of the complex formed by NC 2067 with CDgemini surfactant. Lastly, the in vitro cell toxicity of the formulations toward A375 melanoma cells at various drug-to-carrier mole ratios were measured by cell viability assay. Physical mixtures of NC 2067 and CD or CDgemini surfactant showed characteristics of the individual components, whereas the complex of NC 2067 and CD or CDgemini surfactant presented new structural features, supporting the formation of the host-guest complexes. Complexes of NC 2067 with CDgemini surfactants formed nanoparticles having sizes of 100-200 nm. NC 2067 retained its anticancer activity in the complex with CDgemini surfactant for different drug-to-carrier mole ratios, with an IC50 (half-maximal inhibitory concentration) value comparable to that for NC 2067 without the carrier. The formation of host-guest complexes of NC 2067 with CD or CDgemini surfactant has been confirmed and hence the CDgemini surfactant shows good potential to be used as a delivery system for anticancer agents.

Survival of Lactobacillus plantarum 44a after spraying and drying in feed and during exposure to gastrointestinal tract fluids in vitro.

PubMed

Bucio, Adolfo; Hartemink, Ralf; Schrama, Johan W; Verreth, Johan; Rombouts, Frank M

2005-08-01

A good probiotic strain should be able to survive the conditions of handling and storage to be delivered in high concentration to the host. That is especially important when stressful conditions are prevalent in the carrier, for instance in low water content foods like animal feed. The aim of this research was to study the survival of the probiotic candidate Lactobacillus plantarum 44a after spraying and drying in feed, and during storage and exposure to gastrointestinal tract fluids in vitro. In addition, the viability of the strain during exposure to distilled water and 2% NaCl was studied. Feed was sprayed with a suspension of asymptotically equal to 2 x 10(10) CFU of L. plantarum 44a in 10, 15, 20, 25 and 30% v/w of the feed and dried to constant weight (6% moisture) in a convective oven at 25 degrees C. L. plantarum 44a survived 14.67, 36, 51.86, 78.9 and 105.3% respectively in relation to the original % v/w of the feed. After 3 weeks of storage at 25 degrees C, survival was similarly low in all the treatments. L. plantarum 44a stored in feed containing 13% moisture, vacuum-packaged and stored in refrigeration, maintained high viability (approximately 100%) after 1 year of storage. Survival was not affected after feed-containing lactobacilli was exposed to gastrointestinal fluids in a simulation model. Viability of L. plantarum 44a as a cell suspension in PBS added directly to distilled water or distilled water with 2% NaCl was maintained up to 48 h; after 72 h, viability started to decline. It is concluded that L. plantarum 44a maintained high viability after being dried and stored in feed even after exposure to gastric and intestinal fluids in vitro.

Prokaryotic RNA Associated to Bacterial Viability Induces Polymorphonuclear Neutrophil Activation.

PubMed

Rodriguez-Rodrigues, Nahuel; Castillo, Luis A; Landoni, Verónica I; Martire-Greco, Daiana; Milillo, M Ayelén; Barrionuevo, Paula; Fernández, Gabriela C

2017-01-01

Polymorphonuclear neutrophils (PMN) are the first cellular line of antibacterial host defense. They sense pathogens through recognition of pathogen-associated molecular patterns (PAMPs) by innate pattern recognition receptors, such as Toll-like receptors (TLR). The aim of this study was to investigate whether PMN sense bacterial viability and explore which viability factor could be involved in this phenomenon. For this purpose, different functions were evaluated in isolated human PMN using live Escherichia coli (Ec) and heat-killed Ec (HK-Ec). We found that bacterial viability was indispensable to induce PMN activation, as measured by forward-scatter (FSC) increase, CD11b surface expression, chemotaxis, reactive oxygen species (ROS) generation and neutrophil extracellular trap (NET) formation. As uncapped non-polyadenylated prokaryotic mRNA has been recognized as a PAMP associated to bacterial viability by macrophages and dendritic cells, total prokaryotic RNA (pRNA) from live Ec was purified and used as a stimulus for PMN. pRNA triggered similar responses to those observed with live bacteria. No RNA could be isolated from HK-Ec, explaining the lack of effect of dead bacteria. Moreover, the supernatant of dead bacteria was able to induce PMN activation, and this was associated with the presence of pRNA in this supernatant, which is released in the killing process. The induction of bactericidal functions (ROS and NETosis) by pRNA were abolished when the supernatant of dead bacteria or isolated pRNA were treated with RNAse. Moreover, endocytosis was necessary for pRNA-induced ROS generation and NETosis, and priming was required for the induction of pRNA-induced ROS in whole blood. However, responses related to movement and degranulation (FSC increase, CD11b up-regulation, and chemotaxis) were still triggered when pRNA was digested with RNase, and were not dependent on pRNA endocytosis or PMN priming. In conclusion, our results indicate that PMN sense live bacteria through recognition of pRNA, and this sensing triggers potent bactericidal mechanisms.

Prokaryotic RNA Associated to Bacterial Viability Induces Polymorphonuclear Neutrophil Activation

PubMed Central

Rodriguez-Rodrigues, Nahuel; Castillo, Luis A.; Landoni, Verónica I.; Martire-Greco, Daiana; Milillo, M. Ayelén; Barrionuevo, Paula; Fernández, Gabriela C.

2017-01-01

Polymorphonuclear neutrophils (PMN) are the first cellular line of antibacterial host defense. They sense pathogens through recognition of pathogen-associated molecular patterns (PAMPs) by innate pattern recognition receptors, such as Toll-like receptors (TLR). The aim of this study was to investigate whether PMN sense bacterial viability and explore which viability factor could be involved in this phenomenon. For this purpose, different functions were evaluated in isolated human PMN using live Escherichia coli (Ec) and heat-killed Ec (HK-Ec). We found that bacterial viability was indispensable to induce PMN activation, as measured by forward-scatter (FSC) increase, CD11b surface expression, chemotaxis, reactive oxygen species (ROS) generation and neutrophil extracellular trap (NET) formation. As uncapped non-polyadenylated prokaryotic mRNA has been recognized as a PAMP associated to bacterial viability by macrophages and dendritic cells, total prokaryotic RNA (pRNA) from live Ec was purified and used as a stimulus for PMN. pRNA triggered similar responses to those observed with live bacteria. No RNA could be isolated from HK-Ec, explaining the lack of effect of dead bacteria. Moreover, the supernatant of dead bacteria was able to induce PMN activation, and this was associated with the presence of pRNA in this supernatant, which is released in the killing process. The induction of bactericidal functions (ROS and NETosis) by pRNA were abolished when the supernatant of dead bacteria or isolated pRNA were treated with RNAse. Moreover, endocytosis was necessary for pRNA-induced ROS generation and NETosis, and priming was required for the induction of pRNA-induced ROS in whole blood. However, responses related to movement and degranulation (FSC increase, CD11b up-regulation, and chemotaxis) were still triggered when pRNA was digested with RNase, and were not dependent on pRNA endocytosis or PMN priming. In conclusion, our results indicate that PMN sense live bacteria through recognition of pRNA, and this sensing triggers potent bactericidal mechanisms. PMID:28730145

Effects of Fluid Shear Stress on Cancer Stem Cell Viability

NASA Astrophysics Data System (ADS)

Sunday, Brittney; Triantafillu, Ursula; Domier, Ria; Kim, Yonghyun

2014-11-01

Cancer stem cells (CSCs), which are believed to be the source of tumor formation, are exposed to fluid shear stress as a result of blood flow within the blood vessels. It was theorized that CSCs would be less susceptible to cell death than non-CSCs after both types of cell were exposed to a fluid shear stress, and that higher levels of fluid shear stress would result in lower levels of cell viability for both cell types. To test this hypothesis, U87 glioblastoma cells were cultured adherently (containing smaller populations of CSCs) and spherically (containing larger populations of CSCs). They were exposed to fluid shear stress in a simulated blood flow through a 125-micrometer diameter polyetheretherketone (PEEK) tubing using a syringe pump. After exposure, cell viability data was collected using a BioRad TC20 Automated Cell Counter. Each cell type was tested at three physiological shear stress values: 5, 20, and 60 dynes per centimeter squared. In general, it was found that the CSC-enriched U87 sphere cells had higher cell viability than the CSC-depleted U87 adherent cancer cells. Interestingly, it was also observed that the cell viability was not negatively affected by the higher fluid shear stress values in the tested range. In future follow-up studies, higher shear stresses will be tested. Furthermore, CSCs from different tumor origins (e.g. breast tumor, prostate tumor) will be tested to determine cell-specific shear sensitivity. National Science Foundation Grant #1358991 supported the first author as an REU student.

Effects of cranberry components on IL-1β-stimulated production of IL-6, IL-8 and VEGF by human TMJ synovial fibroblasts.

PubMed

Tipton, David A; Christian, James; Blumer, Adam

2016-08-01

Osteoarthritis (OA) in the TMJ is characterized by deterioration of articular cartilage and secondary inflammatory changes. Interleukin-1β (IL-1β) stimulates IL-6, IL-8, and vascular endothelial growth factor (VEGF) in synovial fluid of TMJ with internal derangement and bony changes. The cranberry (Vaccinium macrocarpon) contains polyphenolic compounds that inhibit production of pro-inflammatory molecules by gingival cells in response to several stimulators. This study examined effects of cranberry components on IL-1β-stimulated IL-6, IL-8, and VEGF production by human TMJ synovial fibroblast-like cells. Cranberry high molecular weight non-dialyzable material (NDM) was derived from cranberry juice. Human TMJ synovial fibroblast-like cells from joints with degenerative OA and an ankylosed TMJ without degeneration were incubated with IL-1β (0.001-1nM)±NDM (25-250μg/ml) (2h preincubation). Viability was assessed via activity of a mitochondrial enzyme. IL-6, IL-8, and VEGF in culture supernatants were measured by ELISA; NF-κB and AP-1 transcription factors were measured in nuclear extracts via binding to specific oligonucleotides. ANOVA and Scheffe's F procedure for post hoc comparisons. NDM did not affect cell viability but inhibited IL-1β stimulated IL-6, IL-8, and VEGF production in all cell lines (p<0.05). NDM partially reduced nuclear levels of NF-κB and AP-1 (p<0.04), depending upon cell line and time of exposure to IL-1β+NDM. Cranberry NDM inhibition of IL-1β-stimulated IL- 6, IL-8, and VEGF production by TMJ synovial fibroblast-like cells suggests that cranberry components may be useful as a host modulatory therapeutic agent to prevent or treat inflammatory arthropathies of the TMJ. Copyright © 2016 Elsevier Ltd. All rights reserved.

The in vitro viability and growth of fibroblasts cultured in the presence of different bone grafting materials (NanoBone and Straumann Bone Ceramic).

PubMed

Kauschke, E; Rumpel, E; Fanghänel, J; Bayerlein, T; Gedrange, T; Proff, P

2006-02-01

Different clinical applications, including dentistry, are making increasing demands on bone grafting material. In the present study we have analysed the viability, proliferation and growth characteristics of fibroblasts cultured in vitro together with two different bone grafting materials, NanoBone and Straumann Bone Ceramic, over a period of 24 and 28 days respectively. Viability was measured at least every 72 hours by using the alamarBlue assay, a test that measures quantitatively cell proliferation and viability but does not require cell fixation or extraction. After one week of culture fibroblast viability was as high as in controls for both grafting materials and remained high (> 90%) for the duration of the experiment. Cell growth was evaluated microscopically. Scanning electron microscopy revealed a dense fibroblast growth at the surface of both bone grafting materials after three weeks of in vitro culture. Generally, our in vitro analyses contribute to further insights into cell - scaffold interactions.

Effects of voluntary exercise on the viability, proliferation and BDNF levels of bone marrow stromal cells in rat pups born from morphine- dependent mothers during pregnancy.

PubMed

Haydari, Sakineh; Safari, Manouchehr; Zarbakhsh, Sam; Bandegi, Ahmad Reza; Miladi-Gorji, Hossein

2016-11-10

This study was designed to investigate whether free access to a running wheel during pregnancy in morphine-dependent mothers would influence the viability, proliferation and BDNF levels of bone marrow stromal cells in rat pups. Pregnant rats were made dependent by chronic administration of morphine in drinking water simultaneously with free access to a running wheel. Male pups are weaned at 21days of birth and their bones marrows were aspirated from the femurs and tibias and also the bone marrow stromal cells (BMSCs) cultured. MTT assay was used to determine cell viability and proliferation rate. The level of BDNF was measured in the supernant of BMSCs culture by ELISA. The sedentary morphine-dependent mothers' pups showed a significant increase in the percentage cell viability and proliferation rate and also a significant decrease in the BDNF protein levels in BMSCs. The rat pups borne from exercising the control and morphine-dependent mothers exhibited an increase in the percentage viability, proliferation rate and BDNF levels of the BMSCs. This study showed that maternal exercise during pregnancy in morphine-dependent and non-dependent mothers, with increasing of BDNF levels increased the proliferation and viability of BMSCs in the rat pups. Also, chronic administration of morphine during pregnancy was able to increase the proliferation and viability of BMSCs in the rat pups. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Effect of doping in carbon nanotubes on the viability of biomimetic chitosan-carbon nanotubes-hydroxyapatite scaffolds.

PubMed

Fonseca-García, Abril; Mota-Morales, Josué D; Quintero-Ortega, Iraís A; García-Carvajal, Zaira Y; Martínez-López, V; Ruvalcaba, Erika; Landa-Solís, Carlos; Solis, Lilia; Ibarra, Clemente; Gutiérrez, María C; Terrones, Mauricio; Sanchez, Isaac C; del Monte, Francisco; Velasquillo, María C; Luna-Bárcenas, G

2014-10-01

This work describes the preparation and characterization of biomimetic chitosan/multiwall carbon nanotubes/nano-hydroxyapatite (CTS/MWCNT/nHAp) scaffolds and their viability for bone tissue engineering applications. The cryogenic process ice segregation-induced self-assembly (ISISA) was used to fabricate 3D biomimetic CTS scaffolds. Proper combination of cryogenics, freeze-drying, nature and molecular ratio of solutes give rise to 3D porous interconnected scaffolds with clusters of nHAp distributed along the scaffold surface. The effect of doping in CNT (e.g. with oxygen and nitrogen atoms) on cell viability was tested. Under the same processing conditions, pore size was in the range of 20-150 μm and irrespective on the type of CNT. Studies on cell viability with scaffolds were carried out using human cells from periosteum biopsy. Prior to cell seeding, the immunophenotype of mesenchymal periosteum or periosteum-derived stem cells (MSCs-PCs) was characterized by flow cytometric analysis using fluorescence-activated and characteristic cell surface markers for MSCs-PCs. The characterized MSCs-PCs maintained their periosteal potential in cell cultures until the 2nd passage from primary cell culture. Thus, the biomimetic CTS/MWCNT/nHAp scaffolds demonstrated good biocompatibility and cell viability in all cases such that it can be considered as promising biomaterials for bone tissue engineering. © 2013 Wiley Periodicals, Inc.

[Impact of cryopreservation duration of 605 units umbilical cord blood on quality of hematopoietic stem cell and outcome of clinical transplantation].

PubMed

Zhang, Yi; Zhu, Hua; Jin, Huanying; Wang, Yinting; Shao, Xiayan; Kong, Jingsi; Huang, Wenhao; Hong, Yan; Li, Chunli; Gao, Feng; Chen, Liang; Wang, Feng; Lu, Yao

2015-01-01

To investigate the impact of cryopreservation duration of umbilical cord blood (UCB) on quality of hematopoietic stem cell and outcome of clinical transplantation. 605 units of UCB which had been used in clinical transplantation were previously cryopreserved for 820 (88-2651) days in average. UCB was detected for total nucleated cell count, CD34+ cells count, cell recovery rate, cell viability and CFU-GM after thawing. No statistical correlation was found between cryopreservation duration and cell recovery rate, cell viability. CFU-GM decreased along with the extension of cryopreservation duration (P=0.011), ranging between 109.6 and 105.7/1 × 10⁵. There was no significant difference on hematopoietic reconstitution time, graft failure, acute GVHD and overall survival among groups with different cryopreservation duration. Cryopreservation duration has no significant effect on cell recovery rate, cell viability and clinical transplantation outcome. Extension of cryopreservation duration may reduce CFU-GM of stem cells with fluctaion still in normal range. UCB could maintain cell viability and function to achieve satisfactory clinical transplantation outcome even when thawed after 3 to 7 years' cryopreservation.

Saccharomyces boulardii expresses neuraminidase activity selective for α2,3-linked sialic acid that decreases Helicobacter pylori adhesion to host cells.

PubMed

Sakarya, Serhan; Gunay, Necati

2014-10-01

Helicobacter pylori is a major causative agent of gastritis and peptic ulcer disease and is an established risk factor for gastric malignancy. Antibiotic combination therapy can eradicate H. pylori. As these same regimens can evoke adverse effects and resistance, new alternative therapies or adjunctive treatments are needed. A probiotic approach may provide a novel strategy for H. pylori treatment. In the current study, two probiotic bacteria, Lactobacillus acidophilus and Lactobacillus reuteri, and a probiotic yeast, Saccharomyces boulardii, were evaluated for their ability to influence H. pylori viability, adherence to gastric and duodenal cells, as well as the effect of S. boulardii on cell surface expression of sialic acid. Our results indicate that S. boulardii contains neuraminidase activity selective for α(2-3)-linked sialic acid. This neuraminidase activity removes surface α(2-3)-linked sialic acid, the ligand for the sialic acid-binding H. pylori adhesin, which in turn, inhibits H. pylori adherence to duodenal epithelial cells. © 2014 APMIS. Published by John Wiley & Sons Ltd.

BAG3 down-modulation sensitizes HPV18(+) HeLa cells to PEITC-induced apoptosis and restores p53.

PubMed

Cotugno, Roberta; Basile, Anna; Romano, Elena; Gallotta, Dario; Belisario, Maria Antonietta

2014-11-28

BAG3 is a multi-functional component of tumor cell pro-survival machinery, and its biological functions have been largely associated to proteasome system. Here, we show that BAG3 down-modulation resulted in reduced cell viability and enhanced PEITC-induced apoptosis largely more extensively in HeLa (HPV18(+)) rather than in C33A (HPV(-)) cervical carcinoma cell lines. Moreover, we demonstrate that BAG3 suppression led to a decrease of viral E6 oncoprotein and a concomitant recovery of p53 tumor suppressor, the best recognized target of E6 for proteasome degradation. E6 and p53 expression were modulated at protein level, since their respective mRNAs were unaffected. Taken together our findings reveal a novel role for BAG3 as host protein contributing to HPV18 E6-activated pro-survival strategies, and suggest a possible relevance of its expression levels in drug/radiotherapy-resistance of HPV18-bearing cervical carcinomas. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Dasatinib and Doxorubicin Treatment of Sarcoma Initiating Cells: A Possible New Treatment Strategy.

PubMed

Aggerholm-Pedersen, Ninna; Demuth, Christina; Safwat, Akmal; Meldgaard, Peter; Kassem, Moustapha; Sandahl Sorensen, Boe

2016-01-01

Background. One of the major challenges affecting sarcoma treatment outcome, particularly that of metastatic disease, is resistance to chemotherapy. Cancer-initiating cells are considered a major contributor to this resistance. Methods. An immortalised nontransformed human stromal (mesenchymal) stem cell line hMSC-TERT4 and a transformed cell line hMSC-TERT20-CE8, known to form sarcoma-like tumours when implanted in immune-deficient mice, were used as models. Receptor tyrosine kinase (RTK) activation was analysed by RTK arrays and cellular viability after tyrosine kinases inhibitor (TKI) treatment with or without doxorubicin was assessed by MTS assay. Results. Initial results showed that the hMSC-TERT4 was more doxorubicin-sensitive while hMSC-TERT20-CE8 was less doxorubicin-sensitive evidenced by monitoring cell viability in the presence of doxorubicin at different doses. The epidermal growth factor receptor (EGFR) was activated in both cell lines. However hMSC-TERT20-CE8 exhibited significantly higher expression of the EGFR ligands. EGFR inhibitors such as erlotinib and afatinib alone or in combination with doxorubicin failed to further decrease cell viability of hMSC-TERT20-CE8. However, inhibition with the TKI dasatinib in combination with doxorubicin decreased cell viability of the hMSC-TERT20-CE8 cell line. Conclusion. Our results demonstrate that dasatinib, but not EGFR-directed treatment, can decrease cell viability of stromal cancer stem cells less sensitive to doxorubicin.

Differences in Tolerance to Host Cactus Alkaloids in Drosophila koepferae and D. buzzatii

PubMed Central

Soto, Ignacio M.; Carreira, Valeria P.; Corio, Cristian; Padró, Julián; Soto, Eduardo M.; Hasson, Esteban

2014-01-01

The evolution of cactophily in the genus Drosophila was a major ecological transition involving over a hundred species in the Americas that acquired the capacity to cope with a variety of toxic metabolites evolved as feeding deterrents in Cactaceae. D. buzzatii and D. koepferae are sibling cactophilic species in the D. repleta group. The former is mainly associated with the relatively toxic-free habitat offered by prickly pears (Opuntia sulphurea) and the latter has evolved the ability to use columnar cacti of the genera Trichocereus and Cereus that contain an array of alkaloid secondary compounds. We assessed the effects of cactus alkaloids on fitness-related traits and evaluated the ability of D. buzzatii and D. koepferae to exploit an artificial novel toxic host. Larvae of both species were raised in laboratory culture media to which we added increasing doses of an alkaloid fraction extracted from the columnar cactus T. terschekii. In addition, we evaluated performance on an artificial novel host by rearing larvae in a seminatural medium that combined the nutritional quality of O. sulphurea plus amounts of alkaloids found in fresh T. terschekii. Performance scores in each rearing treatment were calculated using an index that took into account viability, developmental time, and adult body size. Only D. buzzatii suffered the effects of increasing doses of alkaloids and the artificial host impaired viability in D. koepferae, but did not affect performance in D. buzzatii. These results provide the first direct evidence that alkaloids are key determinants of host plant use in these species. However, the results regarding the artificial novel host suggest that the effects of alkaloids on performance are not straightforward as D. koepferae was heavily affected. We discuss these results in the light of patterns of host plan evolution in the Drosophila repleta group. PMID:24520377

Yeast Modulation of Human Dendritic Cell Cytokine Secretion: An In Vitro Study

PubMed Central

Smith, Ida M.; Christensen, Jeffrey E.; Arneborg, Nils; Jespersen, Lene

2014-01-01

Probiotics are live microorganisms which when administered in adequate amounts confer a health benefit on the host. The concept of individual microorganisms influencing the makeup of T cell subsets via interactions with intestinal dendritic cells (DCs) appears to constitute the foundation for immunoregulatory effects of probiotics, and several studies have reported probiotic strains resulting in reduction of intestinal inflammation through modulation of DC function. Consequent to a focus on Saccharomyces boulardii as the fundamental probiotic yeast, very little is known about hundreds of non-Saccharomyces yeasts in terms of their interaction with the human gastrointestinal immune system. The aim of the present study was to evaluate 170 yeast strains representing 75 diverse species for modulation of inflammatory cytokine secretion by human DCs in vitro, as compared to cytokine responses induced by a S. boulardii reference strain with probiotic properties documented in clinical trials. Furthermore, we investigated whether cytokine inducing interactions between yeasts and human DCs are dependent upon yeast viability or rather a product of membrane interactions regardless of yeast metabolic function. We demonstrate high diversity in yeast induced cytokine profiles and employ multivariate data analysis to reveal distinct clustering of yeasts inducing similar cytokine profiles in DCs, highlighting clear species distinction within specific yeast genera. The observed differences in induced DC cytokine profiles add to the currently very limited knowledge of the cross-talk between yeasts and human immune cells and provide a foundation for selecting yeast strains for further characterization and development toward potentially novel yeast probiotics. Additionally, we present data to support a hypothesis that the interaction between yeasts and human DCs does not solely depend on yeast viability, a concept which may suggest a need for further classifications beyond the current definition of a probiotic. PMID:24816850

Vitamin D enhances resistance to aspergillus fumigatus in mice via inhibition of excessive autophagy.

PubMed

Dai, Jingjing; Liang, Yong; Li, Honglin; Zhou, Wubi; Wang, Bing; Gong, Aijia; Zhang, Rongbo

2018-01-01

The role of vitamin D in the regulation of lung immune defense and inflammatory response has attracted more and more attention. Vitamin D deficiency is closely related to respiratory tract infections. However, few studies have elucidated the mechanism of vitamin D deficiency on host pulmonary resistance to Aspergillus fumigatus ( A. fumigatus ). In this paper, the role of autophagy and Treg regulation in the treatment of rat models of A. fumigatus infection with vitamin D was investigated. We intratracheally injected the A. fumigatus spores into Mice fed with sufficient vitamin D (VitD+) or deficient diets (VitD-). Mortality, fungal load and weight changes were evaluated. The conidia of lung tissue were isolated for analysis of viability. Alveolar macrophages (AMs) were stimulated with a viable A. fumigatus conidia for determining the formation of lysosomes in vitro. The autophagy-related proteins dectin-1, ROS and LC3BII expression in AMs were measured. Fluorescence and Western blot were performed to evaluate the autophagic flux and Treg cells were detected by flow cytometry. After inoculation with A. fumigatus, the vitamin D deficient mice exhibited a higher rate of death, more fungal growth, and more weight loss than its sufficient peers. The viability of A. fumigatus conidia in VitD+ mice was significantly lower than that in VitD- mice. In the case of A. fumigatus infection, vitamin D delays the formation of lysosomes against A. fumigatus through autophagy. The autophagy flow measurement experiment also found that the vitamin D group lowered autophagy levels in cells and a small number of Treg cells. In conclusion, Vitamin D deficiency can lead to impaired lung defense in mice, which may be associated with the formation of excessive autophagy-induced lysosomes and increased counts of Treg cells.

Viability and proliferation of L929, tumour and hybridoma cells in the culture media containing sericin protein as a supplement or serum substitute.

PubMed

Cao, Ting-Ting; Zhang, Yu-Qing

2015-09-01

Cell cultures often require the addition of animal serum and other supplements. In this study, silk sericin, a bioactive protein, recovered from the waste of silk floss production was hydrolysed into three pepsin-degraded sericin peptides with different ranges of molecular mass. Normal animal cells, tumour cells and hybridoma cells were cultured systematically in FBS culture media containing sericin as a supplement or serum substitute. The culture test and microscopic observation of L929 cells showed that the smaller molecular weight of the degraded sericin is most suitable for cell culture. The cell culture results showed that with the degradation of sericin, for normal mouse fibroblast L929 cells, addition of 0.75 % sericin into FBS culture medium yields cell viability that is superior to FBS culture medium alone. When all serum was replaced by sericin, cell viability in the sericin medium could reach about one half of that in FBS medium. When in a medium containing a mixture of FBS: sericin (6:4, v/v), the cell culture effect is about 80 %. For the cultures of four tumour and one hybridoma cells, regardless of the molecular weight range, these degraded sericin peptides could substitute all serum in FBS media. The cell viability and proliferation of these tumour and hybridoma cells are equivalent or superior to that in FBS medium. In other words, cell viability and proliferation of these tumour and hybridoma cells in sericin media are more preferable to serum media. The mechanism of the sericin protein to promote cell growth and proliferation will be further investigated later.

Mechanism of H₂O₂-induced oxidative stress regulating viability and biocontrol ability of Rhodotorula glutinis.

PubMed

Chen, Jian; Li, Boqiang; Qin, Guozheng; Tian, Shiping

2015-01-16

The use of antagonistic yeasts to control postharvest pathogens is a promising alternative to fungicides. The effectiveness of the antagonists against fungal pathogens is greatly dependent on their viability, which is usually mediated by reactive oxygen species (ROS). Here, we investigated the effects of H₂O₂-induced oxidative stress on the viability and biocontrol efficacy of Rhodotorula glutinis and, using flow cytometric analysis, observed the changes of ROS accumulation and apoptosis in the yeast cells with or without H₂O₂ treatment. We found that the viability of R. glutinis decreased in a time- and dose-dependent manner under H₂O₂-induced oxidative stress. Compared to the control, yeast cells exposed to oxidative stress exhibited more accumulation of ROS and higher levels of protein oxidative damage, but showed lower efficacy for biocontrol of Penicillium expansum causing blue mold rot on peach fruit. The results indicate that apoptosis is a main cause of the cell viability loss in R. glutinis, which is attributed to ROS accumulation under oxidative stress. These findings offer a plausible explanation that oxidative stress affects biocontrol efficacy of R. glutinis via regulating its viability and cell apoptosis. Copyright © 2014 Elsevier B.V. All rights reserved.

A cell transportation solution that preserves live circulating tumor cells in patient blood samples.

PubMed

Stefansson, Steingrimur; Adams, Daniel L; Ershler, William B; Le, Huyen; Ho, David H

2016-05-06

Circulating tumor cells (CTCs) are typically collected into CellSave fixative tubes, which kills the cells, but preserves their morphology. Currently, the clinical utility of CTCs is mostly limited to their enumeration. More detailed investigation of CTC biology can be performed on live cells, but obtaining live CTCs is technically challenging, requiring blood collection into biocompatible solutions and rapid isolation which limits transportation options. To overcome the instability of CTCs, we formulated a sugar based cell transportation solution (SBTS) that stabilizes cell viability at ambient temperature. In this study we examined the long term viability of human cancer cell lines, primary cells and CTCs in human blood samples in the SBTS for transportation purposes. Four cell lines, 5 primary human cells and purified human PBMCs were tested to determine the viability of cells stored in the transportation solution at ambient temperature for up to 7 days. We then demonstrated viability of MCF-7 cells spiked into normal blood with SBTS and stored for up to 7 days. A pilot study was then run on blood samples from 3 patients with metastatic malignancies stored with or without SBTS for 6 days. CTCs were then purified by Ficoll separation/microfilter isolation and identified using CTC markers. Cell viability was assessed using trypan blue or CellTracker™ live cell stain. Our results suggest that primary/immortalized cell lines stored in SBTS remain ~90% viable for > 72 h. Further, MCF-7 cells spiked into whole blood remain viable when stored with SBTS for up to 7 days. Finally, live CTCs were isolated from cancer patient blood samples kept in SBTS at ambient temperature for 6 days. No CTCs were isolated from blood samples stored without SBTS. In this proof of principle pilot study we show that viability of cell lines is preserved for days using SBTS. Further, this solution can be used to store patient derived blood samples for eventual isolation of viable CTCs after days of storage. Therefore, we suggest an effective and economical transportation of cancer patient blood samples containing live CTCs can be achieved.

Neuronal Tracing with Magnetic Labels: NMR Imaging Methods, Preliminary Results, and New Optimized Coils.

NASA Astrophysics Data System (ADS)

Ghosh, Pratik

1992-01-01

The investigations focussed on in vivo NMR imaging studies of magnetic particles with and within neural cells. NMR imaging methods, both Fourier transform and projection reconstruction, were implemented and new protocols were developed to perform "Neuronal Tracing with Magnetic Labels" on small animal brains. Having performed the preliminary experiments with neuronal tracing, new optimized coils and experimental set-up were devised. A novel gradient coil technology along with new rf-coils were implemented, and optimized for future use with small animals in them. A new magnetic labelling procedure was developed that allowed labelling of billions of cells with ultra -small magnetite particles in a short time. The relationships among the viability of such cells, the amount of label and the contrast in the images were studied as quantitatively as possible. Intracerebral grafting of magnetite labelled fetal rat brain cells made it possible for the first time to attempt monitoring in vivo the survival, differentiation, and possible migration of both host and grafted cells in the host rat brain. This constituted the early steps toward future experiments that may lead to the monitoring of human brain grafts of fetal brain cells. Preliminary experiments with direct injection of horse radish peroxidase-conjugated magnetite particles into neurons, followed by NMR imaging, revealed a possible non-invasive alternative, allowing serial study of the dynamic transport pattern of tracers in single living animals. New gradient coils were built by using parallel solid-conductor ribbon cables that could be wrapped easily and quickly. Rapid rise times provided by these coils allowed implementation of fast imaging methods. Optimized rf-coil circuit development made it possible to understand better the sample-coil properties and the associated trade -offs in cases of small but conducting samples.

A Lipopeptide Facilitate Induction of Mycobacterium leprae Killing in Host Cells

PubMed Central

Maeda, Yumi; Tamura, Toshiki; Fukutomi, Yasuo; Mukai, Tetsu; Kai, Masanori; Makino, Masahiko

2011-01-01

Little is known of the direct microbicidal activity of T cells in leprosy, so a lipopeptide consisting of the N-terminal 13 amino acids lipopeptide (LipoK) of a 33-kD lipoprotein of Mycobacterium leprae, was synthesized. LipoK activated M. leprae infected human dendritic cells (DCs) to induce the production of IL-12. These activated DCs stimulated autologous CD4+ or CD8+ T cells towards type 1 immune response by inducing interferon-gamma secretion. T cell proliferation was also evident from the CFSE labeling of target CD4+ or CD8+ T cells. The direct microbicidal activity of T cells in the control of M. leprae multiplication is not well understood. The present study showed significant production of granulysin, granzyme B and perforin from these activated CD4+ and CD8+ T cells when stimulated with LipoK activated, M. leprae infected DCs. Assessment of the viability of M. leprae in DCs indicated LipoK mediated T cell-dependent killing of M. leprae. Remarkably, granulysin as well as granzyme B could directly kill M. leprae in vitro. Our results provide evidence that LipoK could facilitate M. leprae killing through the production of effector molecules granulysin and granzyme B in T cells. PMID:22132248

Label-free identification of white blood cell using optical diffraction tomography (Conference Presentation)

NASA Astrophysics Data System (ADS)

Yoon, Jonghee; Kim, Kyoohyun; Kim, Min-hyeok; Kang, Suk-Jo; Park, YongKeun

2016-03-01

White blood cells (WBC) have crucial roles in immune systems which defend the host against from disease conditions and harmful invaders. Various WBC subsets have been characterized and reported to be involved in many pathophysiologic conditions. It is crucial to isolate a specific WBC subset to study its pathophysiological roles in diseases. Identification methods for a specific WBC population are rely on invasive approaches, including Wright-Gimesa staining for observing cellular morphologies and fluorescence staining for specific protein markers. While these methods enable precise classification of WBC populations, they could disturb cellular viability or functions. In order to classify WBC populations in a non-invasive manner, we exploited optical diffraction tomography (ODT). ODT is a three-dimensional (3-D) quantitative phase imaging technique that measures 3-D refractive index (RI) distributions of individual WBCs. To test feasibility of label-free classification of WBC populations using ODT, we measured four subtypes of WBCs, including B cell, CD4 T cell, CD8 T cell, and natural killer (NK) cell. From measured 3-D RI tomograms of WBCs, we obtain quantitative structural and biochemical information and classify each WBC population using a machine learning algorithm.

Manganese-Enhanced Magnetic Resonance Imaging Enables In Vivo Confirmation of Peri-Infarct Restoration Following Stem Cell Therapy in a Porcine Ischemia-Reperfusion Model.

PubMed

Dash, Rajesh; Kim, Paul J; Matsuura, Yuka; Ikeno, Fumiaki; Metzler, Scott; Huang, Ngan F; Lyons, Jennifer K; Nguyen, Patricia K; Ge, Xiaohu; Foo, Cheryl Wong Po; McConnell, Michael V; Wu, Joseph C; Yeung, Alan C; Harnish, Phillip; Yang, Phillip C

2015-07-27

The exact mechanism of stem cell therapy in augmenting the function of ischemic cardiomyopathy is unclear. In this study, we hypothesized that increased viability of the peri-infarct region (PIR) produces restorative benefits after stem cell engraftment. A novel multimodality imaging approach simultaneously assessed myocardial viability (manganese-enhanced magnetic resonance imaging [MEMRI]), myocardial scar (delayed gadolinium enhancement MRI), and transplanted stem cell engraftment (positron emission tomography reporter gene) in the injured porcine hearts. Twelve adult swine underwent ischemia-reperfusion injury. Digital subtraction of MEMRI-negative myocardium (intrainfarct region) from delayed gadolinium enhancement MRI-positive myocardium (PIR and intrainfarct region) clearly delineated the PIR in which the MEMRI-positive signal reflected PIR viability. Human amniotic mesenchymal stem cells (hAMSCs) represent a unique population of immunomodulatory mesodermal stem cells that restored the murine PIR. Immediately following hAMSC delivery, MEMRI demonstrated an increased PIR viability signal compared with control. Direct PIR viability remained higher in hAMSC-treated hearts for >6 weeks. Increased PIR viability correlated with improved regional contractility, left ventricular ejection fraction, infarct size, and hAMSC engraftment, as confirmed by immunocytochemistry. Increased MEMRI and positron emission tomography reporter gene signal in the intrainfarct region and the PIR correlated with sustained functional augmentation (global and regional) within the hAMSC group (mean change, left ventricular ejection fraction: hAMSC 85±60%, control 8±10%; P<0.05) and reduced chamber dilatation (left ventricular end-diastole volume increase: hAMSC 24±8%, control 110±30%; P<0.05). The positron emission tomography reporter gene signal of hAMSC engraftment correlates with the improved MEMRI signal in the PIR. The increased MEMRI signal represents PIR viability and the restorative potential of the injured heart. This in vivo multimodality imaging platform represents a novel, real-time method of tracking PIR viability and stem cell engraftment while providing a mechanistic explanation of the therapeutic efficacy of cardiovascular stem cells. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Analytical Research to Determine the effects of the Components of ONGABO on the Viability of HepG2 Cancer Cells by Using the Sovereign, Minister, Assistant and Courier Principle (君臣佐使論)

PubMed Central

Shin, Jeong-Hun; Jun, Seung-lyul; Hwang, Sung-Yeoun; Ahn, Seong-Hun

2012-01-01

Objectives: This study used the basic principle of Oriental medicine, the sovereign, minister, assistant and courier principle (君臣佐使論) to investigate the effects of the component of ONGABO, which is composed of Ginseng Radix (Red Ginseng), Angelica Gigantis Radix, Schisandrae Fructus, Cuscuta Semen and Curcumae tuber on the viability of HepG2 cells. Methods: Single and mixed extracts of the component of ONGABO were prepared by lypohilizing powder of Red Ginseng (6-year root from Kanghwa), Angelica Gigantis Radix, Schisandrae Fructus, Cuscuta Semen, Curcumae Tuber (from Omniherb Co., Ltd., Korea) at the laboratory of herbal medicine in Woosuk University and were eluted after being macerated with 100% ethanol for three days. The cell viability of HepG2 was determined by using an absorptiometric analysis with PrestoBlue (Invitrogen) reagent after the plate had been incubated for 48 hours. All of the experiments were repeated three times to obtain the average value and standard deviation. The statistical analysis was done and the correlation factor was obtained by using Microsoft Office Excel 2007 and Origin 6.0 software. Results: Although Ginseng Radix (Red Ginseng) and Schisandrae Fructus did not enhance the viability of HepG2 cells, they were shown to provide protection of those cells. On the other hand, Angelica Gigantis Radix decreased the viability of HepG2 cells significantly, Cuscuta Semen and Curcumae Tuber had a small or no effect on the viability of HepG2 cells. Conclusions: In the sovereign, minister, assistant and courier principle (君臣佐使論), Ginseng Radix (Red Ginseng) corresponds to the sovereign component because it provides cell protection effects, Angelica Gigantis Radix corresponds to minister medicinal because it kills cells, Schisandrae Fructus corresponds to the assistant medicinal to help red ginseng having cell protect effects. Cuscuta Semen and Curcumae Tuber correspond to the courier medicinal having no effect in cell viability in HepG2. We hope this study provides motivation for advanced research on the sovereign, minister, assistant and courier principle. PMID:25780653

Analytical Research to Determine the effects of the Components of ONGABO on the Viability of HepG2 Cancer Cells by Using the Sovereign, Minister, Assistant and Courier Principle ().

PubMed

Shin, Jeong-Hun; Jun, Seung-Lyul; Hwang, Sung-Yeoun; Ahn, Seong-Hun

2012-12-01

This study used the basic principle of Oriental medicine, the sovereign, minister, assistant and courier principle () to investigate the effects of the component of ONGABO, which is composed of Ginseng Radix (Red Ginseng), Angelica Gigantis Radix, Schisandrae Fructus, Cuscuta Semen and Curcumae tuber on the viability of HepG2 cells. Single and mixed extracts of the component of ONGABO were prepared by lypohilizing powder of Red Ginseng (6-year root from Kanghwa), Angelica Gigantis Radix, Schisandrae Fructus, Cuscuta Semen, Curcumae Tuber (from Omniherb Co., Ltd., Korea) at the laboratory of herbal medicine in Woosuk University and were eluted after being macerated with 100% ethanol for three days. The cell viability of HepG2 was determined by using an absorptiometric analysis with PrestoBlue (Invitrogen) reagent after the plate had been incubated for 48 hours. All of the experiments were repeated three times to obtain the average value and standard deviation. The statistical analysis was done and the correlation factor was obtained by using Microsoft Office Excel 2007 and Origin 6.0 software. Although Ginseng Radix (Red Ginseng) and Schisandrae Fructus did not enhance the viability of HepG2 cells, they were shown to provide protection of those cells. On the other hand, Angelica Gigantis Radix decreased the viability of HepG2 cells significantly, Cuscuta Semen and Curcumae Tuber had a small or no effect on the viability of HepG2 cells. In the sovereign, minister, assistant and courier principle (), Ginseng Radix (Red Ginseng) corresponds to the sovereign component because it provides cell protection effects, Angelica Gigantis Radix corresponds to minister medicinal because it kills cells, Schisandrae Fructus corresponds to the assistant medicinal to help red ginseng having cell protect effects. Cuscuta Semen and Curcumae Tuber correspond to the courier medicinal having no effect in cell viability in HepG2. We hope this study provides motivation for advanced research on the sovereign, minister, assistant and courier principle.

A Field-Portable Cell Analyzer without a Microscope and Reagents

PubMed Central

Oh, Sangwoo; Lee, Moonjin; Hwang, Yongha

2017-01-01

This paper demonstrates a commercial-level field-portable lens-free cell analyzer called the NaviCell (No-stain and Automated Versatile Innovative cell analyzer) capable of automatically analyzing cell count and viability without employing an optical microscope and reagents. Based on the lens-free shadow imaging technique, the NaviCell (162 × 135 × 138 mm3 and 1.02 kg) has the advantage of providing analysis results with improved standard deviation between measurement results, owing to its large field of view. Importantly, the cell counting and viability testing can be analyzed without the use of any reagent, thereby simplifying the measurement procedure and reducing potential errors during sample preparation. In this study, the performance of the NaviCell for cell counting and viability testing was demonstrated using 13 and six cell lines, respectively. Based on the results of the hemocytometer (de facto standard), the error rate (ER) and coefficient of variation (CV) of the NaviCell are approximately 3.27 and 2.16 times better than the commercial cell counter, respectively. The cell viability testing of the NaviCell also showed an ER and CV performance improvement of 5.09 and 1.8 times, respectively, demonstrating sufficient potential in the field of cell analysis. PMID:29286336

The effect of CO2 laser beam welded AISI 316L austenitic stainless steel on the viability of fibroblast cells, in vitro.

PubMed

Köse, Ceyhun; Kaçar, Ramazan; Zorba, Aslı Pınar; Bağırova, Melahat; Allahverdiyev, Adil M

2016-03-01

It has been determined by the literature research that there is no clinical study on the in vivo and in vitro interaction of the cells with the laser beam welded joints of AISI 316L biomaterial. It is used as a prosthesis and implant material and that has adequate mechanical properties and corrosion resistance characteristics. Therefore, the interaction of the CO2 laser beam welded samples and samples of the base metal of AISI 316L austenitic stainless steel with L929 fibroblast cells as an element of connective tissue under in vitro conditions has been studied. To study the effect of the base metal and the laser welded test specimens on the viability of the fibroblast cells that act as an element of connective tissues in the body, they were kept in DMEMF-12 medium for 7, 14, 28 days and 18 months. The viability study was experimentally studied using the MTT method for 7, 14, 28 days. In addition, the direct interaction of the fibroblast cells seeded on 6 different plates with the samples was examined with an inverted microscope. The MTT cell viability experiment was repeated on the cells that were in contact with the samples. The statistical relationship was analyzed using a Tukey test for the variance with the GraphPad statistics software. The data regarding metallic ion release were identified with the ICP-MS method after the laser welded and main material samples were kept in cell culture medium for 18 months. The cell viability of the laser welded sample has been detected to be higher than that of the base metal and the control based on 7th day data. However, the laser welded sample's viability of the fibroblast cells has diminished by time during the test period of 14 and 28 days and base metal shows better viability when compared to the laser welded samples. On the other hand, the base metal and the laser welded sample show better cell viability effect when compared to the control group. According to the ICP-MS results of the main material and laser welded samples which were kept in the cell culture medium for 18 months, it was determined that the Fe, Ni and Cr ion concentration released to the cell culture medium from the laser welded test sample was less than that of the main material. Copyright © 2015 Elsevier B.V. All rights reserved.

In vitro electrochemical corrosion and cell viability studies on nickel-free stainless steel orthopedic implants.

PubMed

Salahinejad, Erfan; Hadianfard, Mohammad Jafar; Macdonald, Digby Donald; Sharifi-Asl, Samin; Mozafari, Masoud; Walker, Kenneth J; Rad, Armin Tahmasbi; Madihally, Sundararajan V; Tayebi, Lobat

2013-01-01

The corrosion and cell viability behaviors of nanostructured, nickel-free stainless steel implants were studied and compared with AISI 316L. The electrochemical studies were conducted by potentiodynamic polarization and electrochemical impedance spectroscopic measurements in a simulated body fluid. Cytocompatibility was also evaluated by the adhesion behavior of adult human stem cells on the surface of the samples. According to the results, the electrochemical behavior is affected by a compromise among the specimen's structural characteristics, comprising composition, density, and grain size. The cell viability is interpreted by considering the results of the electrochemical impedance spectroscopic experiments.

Evaluation of goat milk as storage media to preserve viability of human periodontal ligament cells in vitro.

PubMed

Ulusoy, Ayça Tuba; Kalyoncuoglu, Elif; Kaya, Senay; Cehreli, Zafer Cavit

2016-08-01

The purpose of this study was to evaluate the effectiveness of goat milk as a storage media for maintenance of periodontal ligament (PDL) cell viability of avulsed teeth and compare it with commonly used and/or investigated storage media. PDL cells were obtained from the root surface of healthy premolars and were cultured in Eagle's maintenance medium (EMM). Cell cultures were treated with the following storage media: tap water (negative control); EMM (positive control); Hank's balanced salt solution; ultra high temperature (UHT) long-shelf-life lactose-free cow milk; UHT long-shelf-life whole cow milk; UHT long-shelf-life skimmed cow milk; UHT long-shelf-life soy milk; UHT long-shelf-life goat milk, UHT long-shelf-life follow on milk with probiotic, 20% propolis, and egg white. Culture plates were incubated with experimental media at 20°C for 1, 3, 6, 12, and 24 h. PDL cell viability was assessed by tetrazolium salt-based colorimetric (MTT) assay at each test period. One-way anova was used to evaluate the effects of storage solutions at each time point, followed by post hoc Duncan's multiple comparison test (P = 0.05). A dendrogram was constructed to show the arrangement of hierarchical clustering. Goat milk displayed the highest capacity to maintain cell viability at all test intervals (P < 0.001). Between 3 and 24 h, milk with the probiotic showed the lowest time-dependent PDL cell viability among all test media (P < 0.001). Compared with all milks, HBSS performed significantly less effectively in maintaining PDL cell viability during the entire test period (P < 0.001). Based on PDL viability, goat milk can be recommended as a suitable storage medium for avulsed teeth. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Storage effect on viability and biofunctionality of human adipose tissue-derived stromal cells.

PubMed

Falah, Mizied; Rayan, Anwar; Srouji, Samer

2015-09-01

In our recent studies, the transplantation of human adipose tissue-derived stromal cells (ASCs) has shown promise for treatment of diseases related to bone and joint disorders. For the current clinical applications, ASCs were formulated and suspended in PlasmaLyte A supplemented with heparin, glucose and human serum albumin, balanced to pH 7.4 with sodium bicarbonate. This cell solution constitutes 20% of the overall transplanted mixture and is supplemented with hyaluronic acid (60%) and OraGraft particles (20%). We intended to investigate the effect of this transplantation mixture on the viability and biofunctionality of ASCs in bone formation. Freshly harvested cells were resuspended and incubated in the indicated mixture for up to 48 h at 4°C. Cell viability was assessed using trypan blue and AlamarBlue, and cell functionality was determined by quantifying their adhesion rate in vitro and bone formation in an ectopic mouse model. More than 80% of the ASCs stored in the transplantation mixture were viable for up to 24 h. Cell viability beyond 24 h in storage decreased to approximately 50%. In addition, an equal degree of bone formation was observed between the cells transplanted following incubation in transplantation mixture for up to 24 h and zero-time non-incubated cells (control). The viability and functionality of ASCs stored in the presented formulation will make such cell therapy accessible to larger and more remote populations. Copyright © 2015 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

Implications for Ophthalmic Formulations: Ocular Buffers Show Varied Cytotoxic Impact on Human Corneal-Limbal and Human Conjunctival Epithelial Cells.

PubMed

Schuerer, Nadine; Stein, Elisabeth; Inic-Kanada, Aleksandra; Pucher, Marion; Hohenadl, Christine; Bintner, Nora; Ghasemian, Ehsan; Montanaro, Jacqueline; Barisani-Asenbauer, Talin

2017-06-01

To investigate toxicity associated with buffers commonly used in topical ocular drug formulations using a human corneal-limbal epithelial (HCLE) and a human conjunctival epithelial (HCjE) cell model. HCLE and HCjE cells were incubated for 10, 30, or 60 minutes with 4 different buffers based on borate, citrate, phosphate, and Tris-HCl at 10, 50, and 100 mM concentrations. To detect possible delayed effects on cell viability, after 60 minutes of buffer incubation, cells were further incubated for 24 hours with a cell medium. Cell viability was determined using a colorimetric XTT-based assay. The morphology of cells was also investigated. HCjE cells showed more sensitivity to buffer incubation than HCLE cells. The 100 mM phosphate buffer displayed significant delayed effects on cell viability of HCLE 16.8 ± 4.8% and HCjE 39.2 ± 6.1% cells after 60 minutes of exposure (P < 0.05). HCjE cell viability was reduced after 60 minutes incubations with 50 and 100 mM citrate buffer to 42.8 ± 6.5% and 39.3 ± 7.9%, respectively, and even lower percentages at the delayed time point (both P < 0.05). HCLE cell morphology was distinctly altered by 100 mM phosphate and Tris buffers after 30 minutes, whereas HCjE cells already showed marked changes after 10 minutes of exposure to 100 mM citrate and phosphate buffers. We observed a time-dependent decrease of viability in both HCLE and HCjE cells exposed to higher buffer concentrations. Therefore, we propose further in vivo studies to translate these finding to humans to discern the real effects of the buffer concentration in eye drops on the ocular surface.

Implications for Ophthalmic Formulations: Ocular Buffers Show Varied Cytotoxic Impact on Human Corneal–Limbal and Human Conjunctival Epithelial Cells

PubMed Central

Schuerer, Nadine; Stein, Elisabeth; Inic-Kanada, Aleksandra; Pucher, Marion; Hohenadl, Christine; Bintner, Nora; Ghasemian, Ehsan; Montanaro, Jacqueline

2017-01-01

Purpose: To investigate toxicity associated with buffers commonly used in topical ocular drug formulations using a human corneal–limbal epithelial (HCLE) and a human conjunctival epithelial (HCjE) cell model. Methods: HCLE and HCjE cells were incubated for 10, 30, or 60 minutes with 4 different buffers based on borate, citrate, phosphate, and Tris-HCl at 10, 50, and 100 mM concentrations. To detect possible delayed effects on cell viability, after 60 minutes of buffer incubation, cells were further incubated for 24 hours with a cell medium. Cell viability was determined using a colorimetric XTT–based assay. The morphology of cells was also investigated. Results: HCjE cells showed more sensitivity to buffer incubation than HCLE cells. The 100 mM phosphate buffer displayed significant delayed effects on cell viability of HCLE 16.8 ± 4.8% and HCjE 39.2 ± 6.1% cells after 60 minutes of exposure (P < 0.05). HCjE cell viability was reduced after 60 minutes incubations with 50 and 100 mM citrate buffer to 42.8 ± 6.5% and 39.3 ± 7.9%, respectively, and even lower percentages at the delayed time point (both P < 0.05). HCLE cell morphology was distinctly altered by 100 mM phosphate and Tris buffers after 30 minutes, whereas HCjE cells already showed marked changes after 10 minutes of exposure to 100 mM citrate and phosphate buffers. Conclusions: We observed a time-dependent decrease of viability in both HCLE and HCjE cells exposed to higher buffer concentrations. Therefore, we propose further in vivo studies to translate these finding to humans to discern the real effects of the buffer concentration in eye drops on the ocular surface. PMID:28399036

Observation of reversible, rapid changes in drug susceptibility of hypoxic tumor cells in a microfluidic device.

PubMed

Germain, Todd; Ansari, Megan; Pappas, Dimitri

2016-09-14

Hypoxia is a major stimulus for increased drug resistance and for survival of tumor cells. Work from our group and others has shown that hypoxia increases resistance to anti-cancer compounds, radiation, and other damage-pathway cytotoxic agents. In this work we utilize a microfluidic culture system capable of rapid switching of local oxygen concentrations to determine changes in drug resistance in prostate cancer cells. We observed rapid adaptation to hypoxia, with drug resistance to 2 μM staurosporine established within 30 min of hypoxia. Annexin-V/Sytox Green apoptosis assays over 9 h showed 78.0% viability, compared to 84.5% viability in control cells (normoxic cells with no staurosporine). Normoxic cells exposed to the same staurosporine concentration had a viability of 48.6% after 9 h. Hypoxia adaptation was rapid and reversible, with Hypoxic cells treated with 20% oxygen for 30 min responding to staurosporine with 51.6% viability after drug treatment for 9 h. Induction of apoptosis through the receptor-mediated pathway, which bypasses anti-apoptosis mechanisms induced by hypoxia, resulted in 39.4 ± 7% cell viability. The rapid reversibility indicates co-treatment of oxygen with anti-cancer compounds may be a potential therapeutic target. Copyright © 2016 Elsevier B.V. All rights reserved.

A comparison of TO-PRO-1 iodide and 5-CFDA-AM staining methods for assessing viability of planktonic algae with epifluorescence microscopy.

PubMed

Gorokhova, Elena; Mattsson, Lisa; Sundström, Annica M

2012-06-01

Two fluorescent dyes, TO-PRO-1 iodide and 5-CFDA-AM, were evaluated for LIVE/DEAD assessment of unicellular marine algae Brachiomonas submarina and Tetraselmis suecica. Epifluorescence microscopy was used to estimate cell viability in predetermined mixtures of viable and non-viable algal cells and validated using microplate growth assay as reference measurements. On average, 5-CFDA-AM underestimated live cell abundance by ~25% compared with viability estimated by the growth assay, whereas TO-PRO-1 iodide provided accurate viability estimates. Furthermore, viability estimates based on staining with TO-PRO-1 iodide were not affected by a storage period of up to one month in -80°C, making the assay a good candidate for routine assessment of phytoplankton populations in field and laboratory studies. Copyright © 2012 Elsevier B.V. All rights reserved.

The Phosphatase PTP-PEST/PTPN12 Regulates Endothelial Cell Migration and Adhesion, but Not Permeability, and Controls Vascular Development and Embryonic Viability*

PubMed Central

Souza, Cleiton Martins; Davidson, Dominique; Rhee, Inmoo; Gratton, Jean-Philippe; Davis, Elaine C.; Veillette, André

2012-01-01

Protein-tyrosine phosphatase (PTP)-PEST (PTPN12) is ubiquitously expressed. It is essential for normal embryonic development and embryonic viability in mice. Herein we addressed the involvement of PTP-PEST in endothelial cell functions using a combination of genetic and biochemical approaches. By generating primary endothelial cells from an inducible PTP-PEST-deficient mouse, we found that PTP-PEST is not needed for endothelial cell differentiation and proliferation or for the control of endothelial cell permeability. Nevertheless, it is required for integrin-mediated adhesion and migration of endothelial cells. PTP-PEST-deficient endothelial cells displayed increased tyrosine phosphorylation of Cas, paxillin, and Pyk2, which were previously also implicated in integrin functions. By eliminating PTP-PEST in endothelial cells in vivo, we obtained evidence that expression of PTP-PEST in endothelial cells is required for normal vascular development and embryonic viability. Therefore, PTP-PEST is a key regulator of integrin-mediated functions in endothelial cells seemingly through its capacity to control Cas, paxillin, and Pyk2. This function explains at least in part the essential role of PTP-PEST in embryonic development and viability. PMID:23105101

Corneal epithelial cell biocompatibility to silicone hydrogel and conventional hydrogel contact lens packaging solutions

PubMed Central

Tanti, N.C.; Jones, L.; Sheardown, H.

2010-01-01

Purpose Although all contact lenses (CLs) are applied initially to the eye directly from a packaging solution, little is known about the effects of these solutions on human corneal epithelial cells (HCECs). Due to the porous nature of CL materials, they have the potential to sorb components of the packaging solution during storage, which could then be subsequently released upon insertion of the CL on the eye. The purpose of this study was to investigate the effect of various packaging solutions on HCECs, using an in vitro model. Methods An in vitro assay was developed whereby various silicone hydrogels and conventional, poly-2-hydroxyethylmethacrylate  (polyHEMA)-based lens materials were removed directly from their packaging and then incubated for up to 24 h with HCECs. The effect of the retained and released packaging solution components on HCECs was assessed by measuring cell viability, adhesion phenotype, and apoptosis. Results Incubation of HCECs with CLs stored in borate-buffered packaging solutions resulted in a significant reduction in cell viability. Adherent cells incubated with these CLs also exhibited reduced levels of β1 and α3 integrin. Soaking borate-buffered packaged CLs in PBS before cell incubation resolved viability and integrin expression in all cases, with the exception of galyfilcon A and balafilcon A, from which a 20% reduction in cell viability was still observed. In comparison, CLs stored in phosphate-buffered packaging solutions had cellular viability and expression of integrins similar to control cells (cells incubated in the absence of a lens). When incubated with cells at a 10% concentration in serum-free medium, borate-buffered packaging solutions and borate-containing saline (Unisol 4) significantly reduced cell viability and integrin expression. Neither caspase activation nor annexin V binding was observed on cells following exposure to borate buffer solution. However, a significant decrease in reactive oxygen species was observed at 24 h. These latter results suggest that in vitro exposure to low concentration of borate/boric acid results in cell dysfunction, leading to necrosis rather than apoptosis. Conclusions Borate-buffered packaging solutions were shown to adversely affect the viability and integrin expression of HCECs in vitro. When used in ophthalmic packaging solutions, the antimicrobial properties of borate buffer may be outweighed by its relatively cytotoxic effects on cells. PMID:20169012

Corneal epithelial cell biocompatibility to silicone hydrogel and conventional hydrogel contact lens packaging solutions.

PubMed

Gorbet, M B; Tanti, N C; Jones, L; Sheardown, H

2010-02-19

Although all contact lenses (CLs) are applied initially to the eye directly from a packaging solution, little is known about the effects of these solutions on human corneal epithelial cells (HCECs). Due to the porous nature of CL materials, they have the potential to sorb components of the packaging solution during storage, which could then be subsequently released upon insertion of the CL on the eye. The purpose of this study was to investigate the effect of various packaging solutions on HCECs, using an in vitro model. An in vitro assay was developed whereby various silicone hydrogels and conventional, poly-2-hydroxyethylmethacrylate (polyHEMA)-based lens materials were removed directly from their packaging and then incubated for up to 24 h with HCECs. The effect of the retained and released packaging solution components on HCECs was assessed by measuring cell viability, adhesion phenotype, and apoptosis. Incubation of HCECs with CLs stored in borate-buffered packaging solutions resulted in a significant reduction in cell viability. Adherent cells incubated with these CLs also exhibited reduced levels of beta(1) and alpha(3) integrin. Soaking borate-buffered packaged CLs in PBS before cell incubation resolved viability and integrin expression in all cases, with the exception of galyfilcon A and balafilcon A, from which a 20% reduction in cell viability was still observed. In comparison, CLs stored in phosphate-buffered packaging solutions had cellular viability and expression of integrins similar to control cells (cells incubated in the absence of a lens). When incubated with cells at a 10% concentration in serum-free medium, borate-buffered packaging solutions and borate-containing saline (Unisol 4) significantly reduced cell viability and integrin expression. Neither caspase activation nor annexin V binding was observed on cells following exposure to borate buffer solution. However, a significant decrease in reactive oxygen species was observed at 24 h. These latter results suggest that in vitro exposure to low concentration of borate/boric acid results in cell dysfunction, leading to necrosis rather than apoptosis. Borate-buffered packaging solutions were shown to adversely affect the viability and integrin expression of HCECs in vitro. When used in ophthalmic packaging solutions, the antimicrobial properties of borate buffer may be outweighed by its relatively cytotoxic effects on cells.

Emerging roles for integrated imaging modalities in cardiovascular cell-based therapeutics: a clinical perspective

PubMed Central

Psaltis, Peter J.; Simari, Robert D.

2012-01-01

Despite preclinical promise, the progress of cell-based therapy to clinical cardiovascular practice has been slowed by several challenges and uncertainties that have been highlighted by the conflicting results of human trials. Most telling has been the revelation that current strategies fall short of achieving sufficient retention and engraftment of cells to meet the ambitious objective of myocardial regeneration. This has sparked novel research into the refinement of cell biology and delivery to overcome these shortcomings. Within this context, molecular imaging has emerged as a valuable tool for providing noninvasive surveillance of cell fate in vivo. Direct and indirect labelling of cells can be coupled with clinically relevant imaging modalities, such as radionuclide single photon emission computed tomography and positron emission tomography, and magnetic resonance imaging, to assess their short- and long-term distributions, along with their viability, proliferation and functional interaction with the host myocardium. This review details the strengths and limitations of the different cell labelling and imaging techniques and their potential application to the clinical realm. We also consider the broader, multifaceted utility of imaging throughout the cell therapy process, providing a discussion of its considerable value during cell delivery and its importance during the evaluation of cardiac outcomes in clinical studies. PMID:21901381

Chondrotoxicity of Liposomal Bupivacaine in Articular Chondrocytes: Preliminary Findings.

PubMed

Shaw, K Aaron; Johnson, Peter C; Zumbrun, Steve; Chuang, Augustine H; Cameron, Craig D

2017-03-01

The chondrotoxicity of local anesthetics has been previously recognized. Recent introduction of a liposomal formulation of bupivacaine has been found to significantly improve postoperative pain control but its effect on chondrocyte viability has yet to be investigated with this new formulation. We sought to assess the in vitro chondrotoxicity of liposomal bupivacaine. Chondrocytes were isolated from articular cartilage from fresh stifle joints and grown in culture medium. Cultured chondrocyte-derived cells (CDCs) were treated with 0.9% normal saline solution, 0.5%, 0.25%, and 0.13% bupivacaine and ropivacaine, 1.3% liposomal bupivacaine for 1 hour. Following treatment, cells were washed and incubated in media for 23 hours. The CDCs were then harvested and viability was assessed by flow cytometry using SYTOX green dead cell stain. Treated CDCs demonstrated a dose-response effect for chondrocyte viability when treated with bupivacaine, ropivacaine, and liposomal bupivacaine. Liposomal bupivacaine demonstrated the highest chondrocyte viability following treatment. Ropivacaine demonstrated higher chondrocyte viability than bupivacaine. Following 1 hour of treatment, liposomal bupivacaine demonstrated the highest chondrocyte viability. Chondrocyte viability was inversely proportional to anesthetic concentration. Reprint & Copyright © 2017 Association of Military Surgeons of the U.S.

Antiproliferative and cytotoxic effects of green coffee and yerba mate extracts, their main hydroxycinnamic acids, methylxanthine and metabolites in different human cell lines.

PubMed

Amigo-Benavent, M; Wang, S; Mateos, R; Sarriá, B; Bravo, L

2017-08-01

This work aimed at studying the effects of green coffee bean (GCBE) and yerba mate (YME) extracts, their main phenolic components (5-caffeoylquinic acid, 5-CQA; 3,5-dicaffeoylquinic acid, 3,5-DCQA) and metabolites (ferulic acid, FA; caffeic acid, CA; dihydrocaffeic acid, DHCA; and dihydroferulic acid, DHFA) along with caffeine (CAF) on the viability and proliferation of different human cell lines. Extracts (10-1000 μg/mL) and standards (10-1000 μM) were assayed in colon (Caco-2), lung (A549), oesophageal (OE-33), urinary bladder (T24) human carcinoma cells, and a non-cancer cell line (CCD-18Co). YME significantly reduced viability of cancer cells at all assayed concentrations, the higher doses also reducing cell proliferation. GCBE effects on cell viability were more effective at 100 and 1000 μg/mL, showing modest effects on cell proliferation. The highest doses of 5-CQA and 3,5-DCQA reduced cell viability and proliferation in all cell lines, whereas FA, DHCA and DHFA had lower and variable effects. Caffeine had no effect. Dietary-attainable concentrations (0.1, 1 and 10 μg/mL) of YME were tested for cytotoxicity and reactive oxygen species generation, showing no cytotoxic effect. Low concentrations of all tested compounds were non-cytotoxic to CCD-18Co cells. YME and to a lower degree GCBE, their phenolic components and metabolites may decrease cancer cell viability and proliferation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Rapid, portable and cost-effective yeast cell viability and concentration analysis using lensfree on-chip microscopy and machine learning.

PubMed

Feizi, Alborz; Zhang, Yibo; Greenbaum, Alon; Guziak, Alex; Luong, Michelle; Chan, Raymond Yan Lok; Berg, Brandon; Ozkan, Haydar; Luo, Wei; Wu, Michael; Wu, Yichen; Ozcan, Aydogan

2016-11-01

Monitoring yeast cell viability and concentration is important in brewing, baking and biofuel production. However, existing methods of measuring viability and concentration are relatively bulky, tedious and expensive. Here we demonstrate a compact and cost-effective automatic yeast analysis platform (AYAP), which can rapidly measure cell concentration and viability. AYAP is based on digital in-line holography and on-chip microscopy and rapidly images a large field-of-view of 22.5 mm 2 . This lens-free microscope weighs 70 g and utilizes a partially-coherent illumination source and an opto-electronic image sensor chip. A touch-screen user interface based on a tablet-PC is developed to reconstruct the holographic shadows captured by the image sensor chip and use a support vector machine (SVM) model to automatically classify live and dead cells in a yeast sample stained with methylene blue. In order to quantify its accuracy, we varied the viability and concentration of the cells and compared AYAP's performance with a fluorescence exclusion staining based gold-standard using regression analysis. The results agree very well with this gold-standard method and no significant difference was observed between the two methods within a concentration range of 1.4 × 10 5 to 1.4 × 10 6 cells per mL, providing a dynamic range suitable for various applications. This lensfree computational imaging technology that is coupled with machine learning algorithms would be useful for cost-effective and rapid quantification of cell viability and density even in field and resource-poor settings.

Reduction of cell viability induced by IFN-alpha generates impaired data on antiviral assay using Hep-2C cells.

PubMed

de Oliveira, Edson R A; Lima, Bruna M M P; de Moura, Wlamir C; Nogueira, Ana Cristina M de A

2013-12-31

Type I interferons (IFNs) exert an array of important biological functions on the innate immune response and has become a useful tool in the treatment of various diseases. An increasing demand in the usage of recombinant IFNs, mainly due to the treatment of chronic hepatitis C infection, augmented the need of quality control for this biopharmaceutical. A traditional bioassay for IFN potency assessment is the cytopathic effect reduction antiviral assay where a given cell line is preserved by IFN from a lytic virus activity using the cell viability as a frequent measure of end point. However, type I IFNs induce other biological effects such as cell-cycle arrest and apoptosis that can influence directly on viability of many cell lines. Here, we standardized a cytopathic effect reduction antiviral assay using Hep-2C cell/mengovirus combination and studied a possible impact of cell viability variations caused by IFN-alpha 2b on responses generated on the antiviral assay. Using the four-parameter logistic model, we observed less correlation and less linearity on antiviral assay when responses from IFN-alpha 2b 1000 IU/ml were considered in the analysis. Cell viability tests with MTT revealed a clear cell growth inhibition of Hep-2C cells under stimulation with IFN-alpha 2b. Flow cytometric cell-cycle analysis and apoptosis assessment showed an increase of S+G2 phase and higher levels of apoptotic cells after treatment with IFN-alpha 2b 1000 IU/ml under our standardized antiviral assay procedure. Considering our studied dose range, we also observed strong STAT1 activation on Hep-2C cells after stimulation with the higher doses of IFN-alpha 2b. Our findings showed that the reduction of cell viability driven by IFN-alpha can cause a negative impact on antiviral assays. We assume that the cell death induction and the cell growth inhibition effect of IFNs should also be considered while employing antiviral assay protocols in a quality control routine and emphasizes the importance of new approaches for IFN potency determination. Copyright © 2013 Elsevier B.V. All rights reserved.

Viability and Isolation of Marine Bacteria by Dilution Culture: Theory, Procedures, and Initial Results

PubMed Central

Button, D. K.; Schut, Frits; Quang, Pham; Martin, Ravonna; Robertson, Betsy R.

1993-01-01

Dilution culture, a method for growing the typical small bacteria from natural aquatic assemblages, has been developed. Each of 11 experimental trials of the technique was successful. Populations are measured, diluted to a small and known number of cells, inoculated into unamended sterilized seawater, and examined three times for the presence of 104 or more cells per ml over a 9-week interval. Mean viability for assemblage members is obtained from the frequency of growth, and many of the cultures produced are pure. Statistical formulations for determining viability and the frequency of pure culture production are derived. Formulations for associated errors are derived as well. Computer simulations of experiments agreed with computed values within the expected error, which verified the formulations. These led to strategies for optimizing viability determinations and pure culture production. Viabilities were usually between 2 and 60% and decreased with >5 mg of amino acids per liter as carbon. In view of difficulties in growing marine oligobacteria, these high values are noteworthy. Significant differences in population characteristics during growth, observed by high-resolution flow cytometry, suggested substantial population diversity. Growth of total populations as well as of cytometry-resolved subpopulations sometimes were truncated at levels of near 104 cells per ml, showing that viable cells could escape detection. Viability is therefore defined as the ability to grow to that population; true viabilities could be even higher. Doubling times, based on whole populations as well as individual subpopulations, were in the 1-day to 1-week range. Data were examined for changes in viability with dilution suggesting cell-cell interactions, but none could be confirmed. The frequency of pure culture production can be adjusted by inoculum size if the viability is known. These apparently pure cultures produced retained the size and apparent DNA-content characteristic of the bulk of the organisms in the parent seawater. Three cultures are now available, two of which have been carried for 3 years. The method is thus seen as a useful step for improving our understanding of typical aquatic organisms. PMID:16348896

Pregnenolone protects the PC-12 cell line against amyloid beta peptide toxicity but its sulfate ester does not.

PubMed

Akan, Pinar; Kizildag, Servet; Ormen, Murat; Genc, Sermin; Oktem, Mehmet Ali; Fadiloglu, Meral

2009-01-15

Pregnenolone (P), the main precursor of the steroids, and its sulfate ester, pregnenolone sulfate (PS), are the major neurosteroids produced in the neural tissue. Many neuroendocrinological studies stressed the neuroprotective role of neurosteroids although it has been suggested that the inhibition of P and PS synthesis can delay neuronal cell death. The potential roles of P and PS in vital neuronal functions and in amyloid beta peptide (Abeta) toxicity are not clearly identified. This work aims to investigate the effects of P and PS on cell viability and Abeta peptide toxicity in a concentration and exposure time-dependent manner in rat PC-12 cells. The cells were treated with 20muM Abeta peptide 25-35 and variable concentrations of P and PS ranging from 0.5muM to 100muM. To examine the effects of steroid treatment on Abeta peptide toxicity, 0.5muM (low) and 50muM (high) neurosteroids were used. The cell viability and lactate dehydrogenase release of cells were evaluated after 24, 48 and 72h. Morphological changes of cells were also examined. The treatment with higher than 1muM concentrations of P and PS significantly decreased the cell viability comparing to untreated cells. At lower concentrations, P and PS had no toxic actions until 72h. The Abeta treatment resulted in a significant decrease in cell viability comparing to untreated cells. P showed a dose-dependent protective effect against Abeta peptide in PC-12 cells. But its sulfate ester did not have the same effect on Abeta peptide toxicity, even it significantly decreased cell viability in Abeta-treated cells. Consequently, the discrepant effects of P and PS on Abeta peptide toxicity may provide insight on the pathogenesis of Alzheimer's disease.

Effect of all-trans retinoic acid (ATRA) on viability, proliferation, activation and lineage-specific transcription factors of CD4+ T cells.

PubMed

Bidad, Katayoon; Salehi, Eisa; Oraei, Mona; Saboor-Yaraghi, Ali-Akbar; Nicknam, Mohammad Hossein

2011-12-01

All-trans retinoic acid (ATRA), as an active metabolite of vitamin A, has been shown to affect immune cells. This study was performed to evaluate the effect of ATRA on viability, proliferation, activation and lineage-specific transcription factors of CD4+ T cells. CD4+ T cells were separated from heparinized blood of healthy donors and were cultured in conditions, some with, some without ATRA. Viability was assessed by PI flowcytometry and proliferation was measured by MTT assay. CD69 expression was determined by flowcytometry as a measure of cell activation. Lineage-specific transcription factors (FOXP3, RORγt and T-bet) were examined by intracellular staining and flowcytometry. High doses of ATRA (0.1-1 mM) caused extensive cell death in both PBMCs and CD4+ T cells. Doses of ATRA equal to or lower than 10 µM did not adversely affect cell viability and proliferation in comparison to culture medium without ATRA. Doses of ATRA between 10 µM and 1nM significantly increased cell activation when compared to culture medium without ATRA. ATRA could increase FOXP3+ and also FOXP3+RORγt+ T cells while it decreased RORγt+ and T-bet+ T cells. This study showed that doses of ATRA up to 10 µM are safe when using with CD4+ T cells in terms of cell viability, proliferation and activation. We could also show that ATRA diverts the human immune response in neutral conditions (without adding polarizing cytokines) by increasing FOXP3+ cells and decreasing RORγt+ cells. ATRA could be regarded as a potential therapy in inflammatory conditions and autoimmunities.

Serum-free cryopreservation of human amniotic epithelial cells before and after isolation from their natural scaffold.

PubMed

Niknejad, Hassan; Deihim, Tina; Peirovi, Habibollah; Abolghasemi, Hassan

2013-08-01

Amniotic epithelial cells are a promising source for stem cell-based therapy through their potential capacity to differentiate into the cell lineages of all three germ layers. Long-term preservation is necessary to have a ready-to-use source of stem cells, when required. Reduced differentiation capability, decrease of viability and use of fetal bovine serum (FBS) are three drawbacks of clinical application of cryopreserved stem cells. In this study, we used human amniotic fluid instead of animal serum, and evaluated viability and multipotency of amniotic epithelial cells after cryopreservation in suspension and compared with those cryopreserved on their natural scaffold (in situ cryopreservation). There was no significant difference in viability of the cells cryopreserved in amniotic fluid and FBS. Also, the same results were achieved for expression of pluripotency marker OCT-4 when FBS was replaced by amniotic fluid in the samples with the same cryoprotectant. The cells cryopreserved in presence of scaffold had a higher level of viability compared to the cells cryopreserved in suspension. Although, the number of the cells expressed OCT-4 significantly decreased within cryopreservation in suspension, no decrease in expression of OCT-4 was observed when the cells cryopreserved with their natural scaffold. Upon culturing of post-thawed cells in specific lineage differentiating mediums, the markers of neuronal, hepatic, cardiomyocytic and pancreatic were found in differentiated cells. These results show that replacement of FBS by amniotic fluid and in situ cryopreservation of amniotic epithelial cells is an effective approach to overcome limitations related to long-term preservation including differentiation during cryopreservation and decrease of viability. Copyright © 2013 Elsevier Inc. All rights reserved.

Biocompatibility of nanoporous alumina membranes for immunoisolation

PubMed Central

La Flamme, Kristen E.; Popat, Ketul C.; Leoni, Lara; Markiewicz, Erica; LaTempa, Thomas J.; Roman, Brian B.; Grimes, Craig A.; Desai, Tejal A.

2011-01-01

Cellular immunoisolation using semi-permeable barriers has been investigated over the past several decades as a promising treatment approach for diseases such as Parkinson’s, Alzheimer’s, and Type 1 diabetes. Typically, polymeric membranes are used for immunoisolation applications; however, recent advances in technology have led to the development of more robust membranes that are able to more completely meet the requirements for a successful immunoisolation device, including well controlled pore size, chemical and mechanical stability, non-biodegradability, and biocompatibility with both the graft tissue as well as the host. It has been shown previously that nanoporous alumina biocapsules can act effectively as immunoisolation devices, and support the viability and functionality of encapsulated β cells. The aim of this investigation was to assess the biocompatibility of the material with host tissue. The cytotoxicity of the capsule, as well as its ability to activate complement and inflammation was studied. Further, the effects of PEG-modification on the tissue response to implanted capsules were studied. Our results have shown that the device is non-toxic and does not induce significant complement activation. Further, in vivo work has demonstrated that implantation of these capsules into the peritoneal cavity of rats induces a transient inflammatory response, and that PEG is useful in minimizing the host response to the material. PMID:17335895

Nanodiamonds on tetrahedral amorphous carbon significantly enhance dopamine detection and cell viability.

PubMed

Peltola, Emilia; Wester, Niklas; Holt, Katherine B; Johansson, Leena-Sisko; Koskinen, Jari; Myllymäki, Vesa; Laurila, Tomi

2017-02-15

We hypothesize that by using integrated carbon nanostructures on tetrahedral amorphous carbon (ta-C), it is possible to take the performance and characteristics of these bioelectrodes to a completely new level. The integrated carbon electrodes were realized by combining nanodiamonds (NDs) with ta-C thin films coated on Ti-coated Si-substrates. NDs were functionalized with mixture of carboxyl and amine groups ND andante or amine ND amine , carboxyl ND vox or hydroxyl groups ND H and drop-casted or spray-coated onto substrate. By utilizing these novel structures we show that (i) the detection limit for dopamine can be improved by two orders of magnitude [from 10µM to 50nM] in comparison to ta-C thin film electrodes and (ii) the coating method significantly affects electrochemical properties of NDs and (iii) the ND coatings selectively promote cell viability. ND andante and ND H showed most promising electrochemical properties. The viability of human mesenchymal stem cells and osteoblastic SaOS-2 cells was increased on all ND surfaces, whereas the viability of mouse neural stem cells and rat neuroblastic cells was improved on ND andante and ND H and reduced on ND amine and ND vox. The viability of C6 cells remained unchanged, indicating that these surfaces will not cause excess gliosis. In summary, we demonstrated here that by using functionalized NDs on ta-C thin films we can significantly improve sensitivity towards dopamine as well as selectively promote cell viability. Thus, these novel carbon nanostructures provide an interesting concept for development of various in vivo targeted sensor solutions. Copyright © 2016 Elsevier B.V. All rights reserved.

Comparison of impact of two decontamination solutions on the viability of the cells in human amnion.

PubMed

Smeringaiova, Ingrida; Trosan, Peter; Mrstinova, Miluse Berka; Matecha, Jan; Burkert, Jan; Bednar, Jan; Jirsova, Katerina

2017-09-01

Human amniotic membrane (HAM) is used as an allograft in regenerative medicine or as a source of pluripotent cells for stem cell research. Various decontamination protocols and solutions are used to sterilize HAM before its application, but little is known about the toxicity of disinfectants on HAM cells. In this study, we tested two decontamination solutions, commercial (BASE·128) and laboratory decontamination solution (LDS), with an analogous content of antimycotic/antibiotics for their cytotoxic effect on HAM epithelial (EC) and mesenchymal stromal cells (MSC). HAM was processed in a standard way, placed on nitrocellulose scaffold, and decontaminated, following three protocols: (1) 6 h, 37 °C; (2) 24 h, room temperature; (3) 24 h, 4 °C. The viability of EC was assessed via trypan blue staining. The apoptotic cells were detected using terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL). The mean % (±SD) of dead EC (%DEC) from six fresh placentas was 12.9 ± 18.1. Decontamination increased %DEC compared to culture medium. Decontamination with BASE·128 for 6 h, 37 °C led to the highest EC viability (81.7%). Treatment with LDS at 24 h, 4 °C resulted in the lowest EC viability (55.9%) in the set. MSC were more affected by apoptosis than EC. Although the BASE·128 expresses lower toxicity compared to LDS, we present LDS as an alternative decontamination solution with a satisfactory preservation of cell viability. The basic formula of LDS will be optimised by enrichment with nutrient components, such as glucose or vitamins, to improve cell viability.

Increase in the nitric oxide release without changes in cell viability of macrophages after laser therapy with 660 and 808 nm lasers.

PubMed

Silva, Igor Henrique Morais; de Andrade, Samantha Cardoso; de Faria, Andreza Barkokebas Santos; Fonsêca, Deborah Daniela Diniz; Gueiros, Luiz Alcino Monteiro; Carvalho, Alessandra Albuquerque Tavares; da Silva, Wylla Tatiana Ferreira; de Castro, Raul Manhães; Leão, Jair Carneiro

2016-12-01

The aim of this study was to evaluate the influence of low-level laser therapy (LLLT) with different parameters and wavelengths on nitric oxide (NO) release and cell viability. Irradiation was performed with Ga-Al-As laser, continuous mode and wavelengths of 660 and 808 nm at different energy and power densities. For each wavelength, powers of 30, 50, and 100 mW and times of 10, 30, and 60 s were used. NO release was measured using Griess reaction, and cell viability was evaluated by mitochondrial reduction of bromide 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) to formazan. LLLT promoted statistically significant changes in NO release and MTT value only at the wavelength of 660 nm (p < 0.05). LLLT also promoted an increase in the NO release and cell viability when the energy densities 64 (p = 0.04) and 214 J/cm 2 (p = 0.012), respectively, were used. LLLT has a significant impact on NO release without affecting cell viability, but the significance of these findings in the inflammatory response needs to be further studied.

Comparison of the effect of three autogenous bone harvesting methods on cell viability in rabbits

PubMed Central

Moradi Haghgoo, Janet; Arabi, Seyed Reza; Hosseinipanah, Seyyed Mohammad; Solgi, Ghasem; Rastegarfard, Neda; Farhadian, Maryam

2017-01-01

Background. This study was designed to compare the viability of autogenous bone grafts, harvested using different methods, in order to determine the best harvesting technique with respect to more viable cells. Methods. In this animal experimental study, three harvesting methods, including manual instrument (chisel), rotary device and piezosurgery, were used for harvesting bone grafts from the lateral body of the mandible on the left and right sides of 10 rabbits. In each group, 20 bone samples were collected and their viability was assessed using MTS kit. Statistical analyses, including ANOVA and post hoc Tukey tests, were used for evaluating significant differences between the groups. Results. One-way ANOVA showed significant differences between all the groups (P=0.000). Data analysis using post hoc Tukey tests indicated that manual instrument and piezosurgery had no significant differences with regard to cell viability (P=0.749) and the cell viability in both groups was higher than that with the use of a rotary instrument (P=0.000). Conclusion. Autogenous bone grafts harvested with a manual instrument and piezosurgery had more viable cells in comparison to the bone chips harvested with a rotary device. PMID:28748046

Withagulatin A inhibits hepatic stellate cell viability and procollagen I production through Akt and Smad signaling pathways

PubMed Central

Liu, Qiong; Chen, Jing; Wang, Xu; Yu, Liang; Hu, Li-hong; Shen, Xu

2010-01-01

Aim: To investigate the effects of the natural product Withagulatin A on hepatic stellate cell (HSC) viability and type I procollagen production. The potential mechanism underlying the pharmacological actions was also explored. Methods: The effect of Withagulatin A on cell viability was evaluated in HSC and LX-2 cells using a sulforhodamine B (SRB) assay. Cell cycle distribution was analyzed using flow cytometry. Type I procollagen gene expression was determined using real-time PCR. Regulation of signaling molecules by Withagulatin A was detected using Western blotting. Results: Primary rat HSCs and the human hepatic stellate cell line LX-2 treated with Withagulatin A (0.625-20 μmol/L) underwent a dose-dependent decrease in cell viability, which was associated with S phase arrest and the induction of cell apoptosis. In addition, the natural product decreased phosphorylation of the Akt/mTOR/p70S6K pathway that controls cell proliferation and survival. Furthermore, Withagulatin A (1, 2 μmol/L) inhibited transforming growth factor-β (TGF-β) stimulated type I procollagen gene expression, which was attributable to the suppression of TGF-β stimulated Smad2 and Smad3 phosphorylation. Conclusion: Our results demonstrated that Withagulatin A potently inhibited HSC viability and type I procollagen production, thereby implying that this natural product has potential use in the development of anti-fibrogenic reagents for the treatment of hepatic fibrosis. PMID:20644552

Enhanced resveratrol production in Vitis vinifera cell suspension cultures by heavy metals without loss of cell viability.

PubMed

Cai, Zhenzhen; Kastell, Anja; Speiser, Claire; Smetanska, Iryna

2013-09-01

The effects of heavy metal ions (Co(2+), Ag(+), Cd(2+)) on cell viability and secondary metabolite production, particularly anthocyanins and phenolic acids in Vitis vinifera cell suspension cultures, were investigated. Of these, Co at all three used concentrations (5.0, 25, and 50 μM), Ag, and Cd at low concentration (5.0 μM) were most effective to stimulate the phenolic acid production, increasing the 3-O-glucosyl-resveratrol up to 1.6-fold of the control level (250.5 versus 152.4 μmol/g), 4 h after the treatments. Meanwhile, the elicitors at effective concentrations did not suppress cell growth, while the cell viability maintained. In contrast, Ag and Cd at high concentrations (25 and 50 μM) remarkably reduced the cell viability, decreasing the cell viability up to about 15 % of the control level, 24 h after the treatments. The heavy metal ions did not affect the anthocyanin production. These observations show how, in a single system, different groups of secondary products can show distinct differences in their responses to potential elicitors. The 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity, peroxidase activity, medium pH value, and conductivity were only slightly elevated by the heavy metal ions. The results suggest that some of the secondary metabolites production was stimulated by the used elicitors, but there was not a stress response of the cells.

Serum-dependent effects of tamoxifen and cannabinoids upon C6 glioma cell viability.

PubMed

Jacobsson, S O; Rongård, E; Stridh, M; Tiger, G; Fowler, C J

2000-12-15

In the present study, the effects of the combination of tamoxifen ((Z)-2[p-(1,2-diphenyl-1-butenyl)phenoxy]-N,N-dimethylamine citrate) and three cannabinoids (Delta(9)-tetrahydrocannabinol [Delta(9)-THC], cannabidiol, and anandamide [AEA]) upon the viability of C6 rat glioma cells was assessed at different incubation times and using different culturing concentrations of foetal bovine serum (FBS). Consistent with previous data for human glioblastoma cells, the tamoxifen sensitivity of the cells was increased as the FBS content of the culture medium was reduced from 10 to 0.4 and 0%. The cells expressed protein kinase C alpha and calmodulin (the concentration of which did not change significantly as the FBS concentration was reduced), but did not express estrogen receptors. Delta(9)-THC and cannabidiol, but not AEA, produced a modest reduction in cell viability after 6 days of incubation in serum-free medium, whereas no effects were seen in 10% FBS-containing medium. There was no observed synergy between the effects of tamoxifen and the cannabinoids upon cell viability.

Effects of cryopreservation and hypothermic storage on cell viability and enzyme activity in recombinant encapsulated cells overexpressing alpha-L-iduronidase.

PubMed

Mayer, Fabiana Quoos; Baldo, Guilherme; de Carvalho, Talita Giacomet; Lagranha, Valeska Lizzi; Giugliani, Roberto; Matte, Ursula

2010-05-01

Here, we show the effects of cryopreservation and hypothermic storage upon cell viability and enzyme release in alginate beads containing baby hamster kidney cells overexpressing alpha-L-iduronidase (IDUA), the enzyme deficient in mucopolysaccharidosis type I. In addition, we compared two different concentrations of alginate gel (1% and 1.5%) in respect to enzyme release from the beads and their shape and integrity. Our results indicate that in both alginate concentrations, the enzyme is released in lower amounts compared with nonencapsulated cells. Alginate 1% beads presented increased levels of IDUA release, although this group presented more deformities when compared with alginate 1.5% beads. Importantly, both encapsulated groups presented higher cell viability after long cryopreservation period and hypothermic storage. In addition, alginate 1.5% beads presented higher enzyme release after freezing protocols. Taken together, our findings suggest a benefic effect of alginate upon cell viability and functionality. These results may have important application for treatment of both genetic and nongenetic diseases using microencapsulation-based artificial organs.

Antagonism of serotonin receptor 1B decreases viability and promotes apoptosis in the COS canine osteosarcoma cell line.

PubMed

Viall, A K; Goodall, C P; Stang, B; Marley, K; Chappell, P E; Bracha, S

2016-06-01

Serotonin receptor 1B (5HTR1B) traditionally exhibits anti-proliferative activity in osteoblasts. We examined the expression and function of 5HTR1B in the COS canine osteosarcoma cell line and normal canine osteoblasts. Equal levels of 5HTR1B gene and protein expression were found between normal and malignant osteoblasts. Treatment with serotonin enhanced viability of osteosarcoma cells but not normal osteoblasts. Challenge with the 5HTR1B agonist anpirtoline caused no change in cell viability. Rather incubation with the specific receptor antagonist SB224289 caused reduction in osteoblast viability, with this effect more substantial in osteosarcoma cells. Investigation of this inhibitory activity showed 5HTR1B antagonism induces apoptosis in malignant cells. Evaluation of phosphorylated levels of CREB and ERK, transcriptional regulators associated with serotonin receptor signalling in osteoblasts, revealed aberrant 5HTR1B signalling in COS. Our results confirm the presence of 5HTR1B in a canine osteosarcoma cell line and highlight this receptor as a possible novel therapeutic target. © 2014 John Wiley & Sons Ltd.

Validation of in vitro assays in three-dimensional human dermal constructs.

PubMed

Idrees, Ayesha; Chiono, Valeria; Ciardelli, Gianluca; Shah, Siegfried; Viebahn, Richard; Zhang, Xiang; Salber, Jochen

2018-05-01

Three-dimensional cell culture systems are urgently needed for cytocompatibility testing of biomaterials. This work aimed at the development of three-dimensional in vitro dermal skin models and their optimization for cytocompatibility evaluation. Initially "murine in vitro dermal construct" based on L929 cells was generated, leading to the development of "human in vitro dermal construct" consisting of normal human dermal fibroblasts in rat tail tendon collagen type I. To assess the viability of the cells, different assays CellTiter-Blue ® , RealTime-Glo ™ MT, and CellTiter-Glo ® (Promega) were evaluated to optimize the best-suited assay to the respective cell type and three-dimensional system. Z-stack imaging (Live/Dead and Phalloidin/DAPI-Promokine) was performed to visualize normal human dermal fibroblasts inside matrix revealing filopodia-like morphology and a uniform distribution of normal human dermal fibroblasts in matrix. CellTiter-Glo was found to be the optimal cell viability assay among those analyzed. CellTiter-Blue reagent affected the cell morphology of normal human dermal fibroblasts (unlike L929), suggesting an interference with cell biological activity, resulting in less reliable viability data. On the other hand, RealTime-Glo provided a linear signal only with a very low cell density, which made this assay unsuitable for this system. CellTiter-Glo adapted to three-dimensional dermal construct by optimizing the "shaking time" to enhance the reagent penetration and maximum adenosine triphosphate release, indicating 2.4 times higher viability value by shaking for 60 min than for 5 min. In addition, viability results showed that cells were viable inside the matrix. This model would be further advanced with more layers of skin to make a full thickness model.

Long non-coding RNA HOTAIR promotes UVB-induced apoptosis and inflammatory injury by up-regulation of PKR in keratinocytes.

PubMed

Liu, Guo; Zhang, Wenhao

2018-06-11

Excessive exposure to ultraviolet (UV) rays can cause damage of the skin and may induce cancer, immunosuppression, photoaging, and inflammation. The long non-coding RNA (lncRNA) HOX antisense intergenic RNA (HOTAIR) is involved in multiple human biological processes. However, its role in UVB-induced keratinocyte injury is unclear. This study was performed to investigate the effects of HOTAIR in UVB-induced apoptosis and inflammatory injury in human keratinocytes (HaCaT cells). Quantitative real-time polymerase chain reaction was performed to analyze the expression levels of HOTAIR, PKR, TNF-α, and IL-6. Cell viability was measured using trypan blue exclusion method and cell apoptosis using flow cytometry and western blot. ELISA was used to measure the concentrations of TNF-α and IL-6. Western blot was used to measure the expression of PKR, apoptosis-related proteins, and PI3K/AKT and NF-κB pathway proteins. UVB induced HaCaT cell injury by inhibiting cell viability and promoting cell apoptosis and expressions of IL-6 and TNF-α. UVB also promoted the expression of HOTAIR. HOTAIR suppression increased cell viability and decreased apoptosis and expression of inflammatory factors in UVB-treated cells. HOTAIR also promoted the expression of PKR. Overexpression of HOTAIR decreased cell viability and increased cell apoptosis and expression of inflammatory factors in UVB-treated cells by upregulating PKR. Overexpression of PKR decreased cell viability and promoted cell apoptosis in UVB-treated cells. Overexpression of PKR activated PI3K/AKT and NF-κB pathways. Our findings identified an essential role of HOTAIR in promoting UVB-induced apoptosis and inflammatory injury by up-regulating PKR in keratinocytes.

Influence of Waveform on Cell Viability during Ultrasound Exposure

NASA Astrophysics Data System (ADS)

Saliev, Timur; Feril, Loreto B.; McLean, Donald A.; Tachibana, Katsuro; Campbell, Paul A.

2011-09-01

We examined the role of ultrasound standing waves, and their travelling wave counterparts, on cell viability in an in-vitro insonation apparatus. Furthermore, the effect of distinct waveforms (sine and top-hat) was also explored, together with the role of microbubble presence. Measurements of cell viability in standing wave scenarios demonstrated a relatively higher rate of lysis (63.13±10.89% remaining viable) compared with the travelling wave data, where 96.22±4.0% remained viable. Significant differences were also seen as a function of waveform, where insonations employing top-hat wave shapes resulted in an average end stage viability of 30.31±5.71% compared with 61.94±14.28% in the sinusoidal counterparts.

Inhibiting ice recrystallization and optimization of cell viability after cryopreservation.

PubMed

Chaytor, Jennifer L; Tokarew, Jacqueline M; Wu, Luke K; Leclère, Mathieu; Tam, Roger Y; Capicciotti, Chantelle J; Guolla, Louise; von Moos, Elisabeth; Findlay, C Scott; Allan, David S; Ben, Robert N

2012-01-01

The ice recrystallization inhibition activity of various mono- and disaccharides has been correlated with their ability to cryopreserve human cell lines at various concentrations. Cell viabilities after cryopreservation were compared with control experiments where cells were cryopreserved with dimethylsulfoxide (DMSO). The most potent inhibitors of ice recrystallization were 220 mM solutions of disaccharides; however, the best cell viability was obtained when a 200 mM d-galactose solution was utilized. This solution was minimally cytotoxic at physiological temperature and effectively preserved cells during freeze-thaw. In fact, this carbohydrate was just as effective as a 5% DMSO solution. Further studies indicated that the cryoprotective benefit of d-galactose was a result of its internalization and its ability to mitigate osmotic stress, prevent intracellular ice formation and/or inhibit ice recrystallization. This study supports the hypothesis that the ability of a cryoprotectant to inhibit ice recrystallization is an important property to enhance cell viability post-freeze-thaw. This cryoprotective benefit is observed in three different human cell lines. Furthermore, we demonstrated that the ability of a potential cryoprotectant to inhibit ice recrystallation may be used as a predictor of its ability to preserve cells at subzero temperatures.

Potential functional bakery products as delivery systems for prebiotics and probiotics health enhancers.

PubMed

Longoria-García, S; Cruz-Hernández, M A; Flores-Verástegui, M I M; Contreras-Esquivel, J C; Montañez-Sáenz, J C; Belmares-Cerda, R E

2018-03-01

Several health benefits have been associated to probiotics and prebiotics, most of these are involved in the regulation of the host's gut microbiome. Their incorporation to diverse food products has been done to develop potential functional foods. In the case of bakery products, their incorporation has been seen to improve several technological parameters such as volume, specific volume, texture along with sensorial parameters such as flavor and aroma. Scientific literature in this topic has been divided in three main research branches: nutrition, physical quality and sensory analyzes, however, studies rarely cover all of them. Due to the harsh thermal stress during baking, sourdough technology along with microencapsulation of probiotics, has been studied as an alternative to enhance its nutritional values and increase cell viability, though in few occasions. The potential functional baked goods have maintained acceptable physical characteristics and sensorial acceptability, while in some cases an improvement is seen due to the effect of probiotics and prebiotics. The results obtained from several studies done, have shown the viability of developing functional bakery products by applying prebiotics or probiotics. This could be used as an encouragement for more research to be done in this topic.

[Octanol preconditioning alleviates mouse cardiomyocyte swelling induced by simulated ischemia/reperfusion challenge in vitro].

PubMed

Luo, Yukun; Fang, Jun; Fan, Lin; Lin, Chaogui; Chen, Zhaoyang; Chen, Lianglong

2012-10-01

To investigate the role of connexin 43-formed hemichannels in cell volume regulation induced by simulated ischemia/reperfusion (SI/R). Mouse cardiomyocytes isolated on a Langendorff apparatus with enzyme solution were aliquoted into control, SI/R and SI/R +octanol groups. Calcein-AM was used to stain the cells and the cell volume was measured with confocal microscope by stack scanning. Trypan blue was used to measure the cell viability after the treatments. Calcein-AM staining and cofocal microscopy yielded stable and reproducible results for cell volume measurement. Mouse cardiomyocytes subjected to simulated SI/R showed obvious cell swelling as compared with the control cells [(126∓6)% vs 100%, P<0.05], and octanol preconditioning significantly attenuated the cell swelling [(113∓6)%, P<0.05]. SI/R caused a significant reduction of the cell viability compared to the control cells [(19∓2)% vs (45∓3)%, P<0.01], and octanol preconditioning obviously reduced the viability of the cells with SI/R challenge [(31∓2)%, P<0.01]. Connexin 43-formed hemichannels are involved in the regulation of cardiomyocyte volumes induced by SI/R challenge, and octanol can alleviate the cell swelling to enhance the viability of the cardiomyocytes following SI/R.

Engineering Pre-vascularized Scaffolds for Bone Regeneration.

PubMed

Barabaschi, Giada D G; Manoharan, Vijayan; Li, Qing; Bertassoni, Luiz E

2015-01-01

Survival of functional tissue constructs of clinically relevant size depends on the formation of an organized and uniformly distributed network of blood vessels and capillaries. The lack of such vasculature leads to spatio-temporal gradients in oxygen, nutrients and accumulation of waste products inside engineered tissue constructs resulting in negative biological events at the core of the scaffold. Unavailability of a well-defined vasculature also results in ineffective integration of scaffolds to the host vasculature upon implantation. Arguably, one of the greatest challenges in engineering clinically relevant bone substitutes, therefore, has been the development of vascularized bone scaffolds. Various approaches ranging from peptide and growth factor functionalized biomaterials to hyper-porous scaffolds have been proposed to address this problem with reasonable success. An emerging alternative to address this challenge has been the fabrication of pre-vascularized scaffolds by taking advantage of biomanufacturing techniques, such as soft- and photo-lithography or 3D bioprinting, and cell-based approaches, where functional capillaries are engineered in cell-laden scaffolds prior to implantation. These strategies seek to engineer pre-vascularized tissues in vitro, allowing for improved anastomosis with the host vasculature upon implantation, while also improving cell viability and tissue development in vitro. This book chapter provides an overview of recent methods to engineer pre-vascularized scaffolds for bone regeneration. We first review the development of functional blood capillaries in bony structures and discuss controlled delivery of growth factors, co-culture systems, and on-chip studies to engineer vascularized cell-laden biomaterials. Lastly, we review recent studies using microfabrication techniques and 3D printing to engineer pre-vascularized scaffolds for bone tissue engineering.

Measurement of cell viability in in vitro cultures.

PubMed

Castro-Concha, Lizbeth A; Escobedo, Rosa María; Miranda-Ham, María de Lourdes

2006-01-01

An overview of the methods for assessing cell viability in in vitro cultures is presented. The protocols of four of the most commonly used assays are described in detail, so the readers may be able to determine which assay is suitable for their own projects using plant cell cultures.

Hydrogen Supplementation of Preservation Solution Improves Viability of Osteochondral Grafts

PubMed Central

Yamada, Takuya; Onuma, Kenji; Kuzuno, Jun; Ujihira, Masanobu; Kurokawa, Ryosuke; Sakai, Rina; Takaso, Masashi

2014-01-01

Allogenic osteochondral tissue (OCT) is used for the treatment of large cartilage defects. Typically, OCTs collected during the disease-screening period are preserved at 4°C; however, the gradual reduction in cell viability during cold preservation adversely affects transplantation outcomes. Therefore, improved storage methods that maintain the cell viability of OCTs are needed to increase the availability of high-quality OCTs and improve treatment outcomes. Here, we evaluated whether long-term hydrogen delivery to preservation solution improved the viability of rat OCTs during cold preservation. Hydrogen-supplemented Dulbecco's Modified Eagles Medium (DMEM) and University of Wisconsin (UW) solution both significantly improved the cell viability of OCTs during preservation at 4°C for 21 days compared to nonsupplemented media. However, the long-term cold preservation of OCTs in DMEM containing hydrogen was associated with the most optimal maintenance of chondrocytes with respect to viability and morphology. Our findings demonstrate that OCTs preserved in DMEM supplemented with hydrogen are a promising material for the repair of large cartilage defects in the clinical setting. PMID:25506061

Comparison of different particles and methods for magnetic isolation of circulating tumor cells

NASA Astrophysics Data System (ADS)

Sieben, S.; Bergemann, C.; Lübbe, A.; Brockmann, B.; Rescheleit, D.

2001-01-01

A more effective method for tumor cell separation from peripheral blood was established. The results of optimized magnetic particles verified by analyzing yield, purity and viability of isolated epithelial tumor cells were compared with a commercial kit for immunomagnetic cell separation. Porous silica particles of 230 nm were found to give best recovery rates and high viability of extracted cells.

Enrofloxacin and Toltrazuril Are Able to Reduce Toxoplasma gondii Growth in Human BeWo Trophoblastic Cells and Villous Explants from Human Third Trimester Pregnancy

PubMed Central

da Silva, Rafaela J.; Gomes, Angelica O.; Franco, Priscila S.; Pereira, Ariane S.; Milian, Iliana C. B.; Ribeiro, Mayara; Fiorenzani, Paolo; dos Santos, Maria C.; Mineo, José R.; da Silva, Neide M.; Ferro, Eloisa A. V.; de Freitas Barbosa, Bellisa

2017-01-01

Classical treatment for congenital toxoplasmosis is based on combination of sulfadiazine and pyrimethamine plus folinic acid. Due to teratogenic effects and bone marrow suppression caused by pyrimethamine, the establishment of new therapeutic strategies is indispensable to minimize the side effects and improve the control of infection. Previous studies demonstrated that enrofloxacin and toltrazuril reduced the incidence of Neospora caninum and Toxoplasma gondii infection. The aim of the present study was to evaluate the efficacy of enrofloxacin and toltrazuril in the control of T. gondii infection in human trophoblast cells (BeWo line) and in human villous explants from the third trimester. BeWo cells and villous were treated with several concentrations of enrofloxacin, toltrazuril, sulfadiazine, pyrimethamine, or combination of sulfadiazine+pyrimethamine, and the cellular or tissue viability was verified. Next, BeWo cells were infected by T. gondii (2F1 clone or the ME49 strain), whereas villous samples were only infected by the 2F1 clone. Then, infected cells and villous were treated with all antibiotics and the T. gondii intracellular proliferation as well as the cytokine production were analyzed. Finally, we evaluated the direct effect of enrofloxacin and toltrazuril in tachyzoites to verify possible changes in parasite structure. Enrofloxacin and toltrazuril did not decrease the viability of cells and villous in lower concentrations. Both drugs were able to significantly reduce the parasite intracellular proliferation in BeWo cells and villous explants when compared to untreated conditions. Regardless of the T. gondii strain, BeWo cells infected and treated with enrofloxacin or toltrazuril induced high levels of IL-6 and MIF. In villous explants, enrofloxacin induced high MIF production. Finally, the drugs increased the number of unviable parasites and triggered damage to tachyzoite structure. Taken together, it can be concluded that enrofloxacin and toltrazuril are able to control T. gondii infection in BeWo cells and villous explants, probably by a direct action on the host cells and parasites, which leads to modifications of cytokine release and tachyzoite structure. PMID:28798905

Enrofloxacin and Toltrazuril Are Able to Reduce Toxoplasma gondii Growth in Human BeWo Trophoblastic Cells and Villous Explants from Human Third Trimester Pregnancy.

PubMed

da Silva, Rafaela J; Gomes, Angelica O; Franco, Priscila S; Pereira, Ariane S; Milian, Iliana C B; Ribeiro, Mayara; Fiorenzani, Paolo; Dos Santos, Maria C; Mineo, José R; da Silva, Neide M; Ferro, Eloisa A V; de Freitas Barbosa, Bellisa

2017-01-01

Classical treatment for congenital toxoplasmosis is based on combination of sulfadiazine and pyrimethamine plus folinic acid. Due to teratogenic effects and bone marrow suppression caused by pyrimethamine, the establishment of new therapeutic strategies is indispensable to minimize the side effects and improve the control of infection. Previous studies demonstrated that enrofloxacin and toltrazuril reduced the incidence of Neospora caninum and Toxoplasma gondii infection. The aim of the present study was to evaluate the efficacy of enrofloxacin and toltrazuril in the control of T. gondii infection in human trophoblast cells (BeWo line) and in human villous explants from the third trimester. BeWo cells and villous were treated with several concentrations of enrofloxacin, toltrazuril, sulfadiazine, pyrimethamine, or combination of sulfadiazine+pyrimethamine, and the cellular or tissue viability was verified. Next, BeWo cells were infected by T. gondii (2F1 clone or the ME49 strain), whereas villous samples were only infected by the 2F1 clone. Then, infected cells and villous were treated with all antibiotics and the T. gondii intracellular proliferation as well as the cytokine production were analyzed. Finally, we evaluated the direct effect of enrofloxacin and toltrazuril in tachyzoites to verify possible changes in parasite structure. Enrofloxacin and toltrazuril did not decrease the viability of cells and villous in lower concentrations. Both drugs were able to significantly reduce the parasite intracellular proliferation in BeWo cells and villous explants when compared to untreated conditions. Regardless of the T. gondii strain, BeWo cells infected and treated with enrofloxacin or toltrazuril induced high levels of IL-6 and MIF. In villous explants, enrofloxacin induced high MIF production. Finally, the drugs increased the number of unviable parasites and triggered damage to tachyzoite structure. Taken together, it can be concluded that enrofloxacin and toltrazuril are able to control T. gondii infection in BeWo cells and villous explants, probably by a direct action on the host cells and parasites, which leads to modifications of cytokine release and tachyzoite structure.

Comparison of liposomal and 2-hydroxypropyl-β-cyclodextrin-lidocaine on cell viability and inflammatory response in human keratinocytes and gingival fibroblasts.

PubMed

Ferreira, Luiz Eduardo Nunes; Muniz, Bruno Vilela; Dos Santos, Cleiton Pita; Volpato, Maria Cristina; de Paula, Eneida; Groppo, Francisco Carlos

2016-06-01

The aim of this study was to observe the effect multilamellar liposomes (MLV) and 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) in the in-vitro effects of lidocaine in cell viability, pro-inflammatory cytokines and prostaglandin E2 release of both human keratinocytes (HaCaT) and gingival fibroblasts (HGF) cells. HaCaT and HGF cells were exposed to lidocaine 100-1 μm in plain, MLV and HP-β-CD formulations for 6 h or 24 h. The formulation effects in cell viability were measured by XTT assay and by fluorescent labelling. Cytokines (IL-8, IL-6 and TNF-α) and PGE2 release were quantified by ELISA. MLV and HP-β-CD formulations did not affect the HaCaT viability, which was significantly decreased by plain lidocaine after 24 h of exposure. Both drug carriers increased all cytokines released by HGF after 24-h exposure, and none of the carriers was able to reduce the PGE2 release induced by lidocaine. The effect of drug carrier in the lidocaine effects was dependent on the cell type, concentration and time of exposure. MLV and HP-β-CD showed benefits in improving cell viability; however, both of them showed a tendency to increase cytokine release when compared to the plain solution. © 2016 Royal Pharmaceutical Society.

Novel model for multispecies biofilms that uses rigid gas-permeable lenses.

PubMed

Peyyala, Rebecca; Kirakodu, Sreenatha S; Ebersole, Jeffrey L; Novak, Karen F

2011-05-01

Oral biofilms comprise complex multispecies consortia aided by specific inter- and intraspecies interactions occurring among commensals and pathogenic bacterial species. Oral biofilms are primary initiating factors of periodontal disease, although complex multifactorial biological influences, including host cell responses, contribute to the individual outcome of the disease. To provide a system to study initial stages of interaction between oral biofilms and the host cells that contribute to the disease process, we developed a novel in vitro model system to grow biofilms on rigid gas-permeable contact lenses (RGPLs), which enable oxygen to permeate through the lens material. Bacterial species belonging to early- and late-colonizing groups were successfully established as single- or three-species biofilms, with each group comprising Streptococcus gordonii, Streptococcus oralis, and Streptococcus sanguinis; S. gordonii, Actinomyces naeslundii, and Fusobacterium nucleatum; or S. gordonii, F. nucleatum, and Porphyromonas gingivalis. Quantification of biofilm numbers by quantitative PCR (qPCR) revealed substantial differences in the magnitude of bacterial numbers in single-species and multispecies biofilms. We evaluated cell-permeable conventional nucleic acid stains acridine orange, hexidium iodide, and Hoechst 33258 and novel SYTO red, blue, and green fluorochromes for their effect on bacterial viability and fluorescence yield to allow visualization of the aggregates of individual bacterial species by confocal laser scanning microscopy (CLSM). Substantial differences in the quantity and distribution of the species in the multispecies biofilms were identified. The specific features of these biofilms may help us better understand the role of various bacteria in local challenge of oral tissues.

Antitumor Responses Stimulated by Dendritic Cells Are Improved by Triiodothyronine Binding to the Thyroid Hormone Receptor β.

PubMed

Alamino, Vanina A; Mascanfroni, Iván D; Montesinos, María M; Gigena, Nicolás; Donadio, Ana C; Blidner, Ada G; Milotich, Sonia I; Cheng, Sheue-Yann; Masini-Repiso, Ana M; Rabinovich, Gabriel A; Pellizas, Claudia G

2015-04-01

Bidirectional cross-talk between the neuroendocrine and immune systems orchestrates immune responses in both physiologic and pathologic settings. In this study, we provide in vivo evidence of a critical role for the thyroid hormone triiodothyronine (T3) in controlling the maturation and antitumor functions of dendritic cells (DC). We used a thyroid hormone receptor (TR) β mutant mouse (TRβPV) to establish the relevance of the T3-TRβ system in vivo. In this model, TRβ signaling endowed DCs with the ability to stimulate antigen-specific cytotoxic T-cell responses during tumor development. T3 binding to TRβ increased DC viability and augmented DC migration to lymph nodes. Moreover, T3 stimulated the ability of DCs to cross-present antigens and to stimulate cytotoxic T-cell responses. In a B16-OVA mouse model of melanoma, vaccination with T3-stimulated DCs inhibited tumor growth and prolonged host survival, in part by promoting the generation of IFNγ-producing CD8(+) T cells. Overall, our results establish an adjuvant effect of T3-TRβ signaling in DCs, suggesting an immediately translatable method to empower DC vaccination approaches for cancer immunotherapy. ©2015 American Association for Cancer Research.

Radiotolerance of phosphatases of a Serratia sp.: potential for the use of this organism in the biomineralization of wastes containing radionuclides.

PubMed

Paterson-Beedle, M; Jeong, B C; Lee, C H; Jee, K Y; Kim, W H; Renshaw, J C; Macaskie, L E

2012-08-01

Aqueous wastes from nuclear fuel reprocessing present special problems of radiotoxicity of the active species. Cells of Serratia sp. were found previously to accumulate high levels of hydrogen uranyl phosphate (HUP) via the activity of a phosphatase enzyme. Uranium is of relatively low radiotoxicity whereas radionuclide fission products such as (90)Sr and (137)Cs are highly radiotoxic. These radionuclides can be co-crystallized, held within the bio-HUP "host" lattice on the bacterial cells and thereby removed from contaminated solution, depending on continued phosphatase activity. Radiostability tests using a commercial (60)Co γ-source showed that while cell viability and activity of purified phosphatase were lost within a few hours on irradiation, whole-cell phosphatase retained 80% of the initial activity, even after loss of cell culturability, which was increased to 100% by the incorporation of mercaptoethanol as an example radioprotectant, beyond an accumulated dose of >1.3 MGy. Using this co-crystallization approach (without mercaptoethanol) (137)Cs(+) and (85)Sr(2+) were removed from a simulated waste selectively against a 33-fold excess of Na(+). Copyright © 2012 Wiley Periodicals, Inc.

SMC1A recruits tumor-associated-fibroblasts (TAFs) and promotes colorectal cancer metastasis.

PubMed

Zhou, Pengyang; Xiao, Nan; Wang, Jian; Wang, Zhanhuai; Zheng, Shuchun; Shan, Siyang; Wang, Jianping; Du, Jinlin; Wang, Jianwei

2017-01-28

Tumor-associated-fibroblasts (TAFs) are the most important host cells in the stroma and take part in extracellular matrix construction and cancer colony development. During cancer colonization, seed cells from primary tumor can reconstruct the microenvironment by recruiting circulating cancer cells and TAFs to the metastasis site. Previous studies have established that SMC1A, a subunit of cohesin, is an important trigger signal for liver metastasis in colorectal cancer. We investigated the particular effects as well as the underlying mechanism of SMC1A on TAFs recruitment during liver metastasis of colorectal cancer. Here, We found that: first, the high expression of SMC1A in colorectal cancer cells promotes the invasiveness and the viability of these cells by recruiting circulating TAFs, facilitating early tumor construction and tumorigenesis; second, different expression levels of SMC1A influenced the reformation of fibroblasts, which assisted tumorigenesis, and third, expression of SMC1A stimulated the secretion of the inflammatory mediators of TNF-α and IL-1β, and up-regulated the transcriptional expression of MMP2 and VEGF-β, both of which were involved in the tumor-related gene pathway. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

In Vitro Electrochemical Corrosion and Cell Viability Studies on Nickel-Free Stainless Steel Orthopedic Implants

PubMed Central

Salahinejad, Erfan; Hadianfard, Mohammad Jafar; Macdonald, Digby Donald; Sharifi-Asl, Samin; Mozafari, Masoud; Walker, Kenneth J.; Rad, Armin Tahmasbi; Madihally, Sundararajan V.; Tayebi, Lobat

2013-01-01

The corrosion and cell viability behaviors of nanostructured, nickel-free stainless steel implants were studied and compared with AISI 316L. The electrochemical studies were conducted by potentiodynamic polarization and electrochemical impedance spectroscopic measurements in a simulated body fluid. Cytocompatibility was also evaluated by the adhesion behavior of adult human stem cells on the surface of the samples. According to the results, the electrochemical behavior is affected by a compromise among the specimen's structural characteristics, comprising composition, density, and grain size. The cell viability is interpreted by considering the results of the electrochemical impedance spectroscopic experiments. PMID:23630603

The effect of cell density, proximity, and time on the cytotoxicity of magnesium and galvanically coupled magnesium-titanium particles in vitro.

PubMed

Kim, Jua; Gilbert, Jeremy L

2018-05-01

Magnesium (Mg) and galvanically coupled magnesium-titanium (Mg-Ti) particles in vitro have been reported previously to kill cells in a dosage-dependent manner. Mg-Ti particles kill cells more effectively than Mg alone, due to the galvanic effect of Mg and Ti. This study further investigated the in vitro cytotoxicity of Mg and Mg-Ti in terms of particle concentration, cell density, time, and proximity. Cell density has an effect on cell viability only at low particle concentrations (below 250 µg/mL), where cell viability dropped only for lower cell densities (5000-10,000 cells/cm 2 ) and not for higher cell densities (20,000-30,000 cells/cm 2 ), showing that the particles cannot kill if there are more cells present. Cytotoxicity of Mg and Mg-Ti particles is quick and temporary, where the particles kill cells only during particle corrosion (first 24 h). Depending on the percentage of surviving cells, particle concentrations, and ongoing corrosion activity, the remaining live cells either proliferated and recovered, or just remained viable and quiescent. The particle killing is also proximity-dependent, where cell viability was significantly higher for cells far away from the particles (greater than ∼1 mm) compared to those close to the particles (less than ∼1 mm). Although the increase of pH does affect cell viability negatively, it is not the sole killing factor since cell viability is significantly dependent on particle type and proximity but not pH. Mg and Mg-Ti particles used in this study are large enough to prevent direct cell phagocytosis so that the cell killing effect may be attributed to solely electrochemical reactions. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1428-1439, 2018. © 2018 Wiley Periodicals, Inc.

Construction and Characterization of an in-vivo Linear Covalently Closed DNA Vector Production System

PubMed Central

2012-01-01

Background While safer than their viral counterparts, conventional non-viral gene delivery DNA vectors offer a limited safety profile. They often result in the delivery of unwanted prokaryotic sequences, antibiotic resistance genes, and the bacterial origins of replication to the target, which may lead to the stimulation of unwanted immunological responses due to their chimeric DNA composition. Such vectors may also impart the potential for chromosomal integration, thus potentiating oncogenesis. We sought to engineer an in vivo system for the quick and simple production of safer DNA vector alternatives that were devoid of non-transgene bacterial sequences and would lethally disrupt the host chromosome in the event of an unwanted vector integration event. Results We constructed a parent eukaryotic expression vector possessing a specialized manufactured multi-target site called “Super Sequence”, and engineered E. coli cells (R-cell) that conditionally produce phage-derived recombinase Tel (PY54), TelN (N15), or Cre (P1). Passage of the parent plasmid vector through R-cells under optimized conditions, resulted in rapid, efficient, and one step in vivo generation of mini lcc—linear covalently closed (Tel/TelN-cell), or mini ccc—circular covalently closed (Cre-cell), DNA constructs, separated from the backbone plasmid DNA. Site-specific integration of lcc plasmids into the host chromosome resulted in chromosomal disruption and 105 fold lower viability than that seen with the ccc counterpart. Conclusion We offer a high efficiency mini DNA vector production system that confers simple, rapid and scalable in vivo production of mini lcc DNA vectors that possess all the benefits of “minicircle” DNA vectors and virtually eliminate the potential for undesirable vector integration events. PMID:23216697

Construction and characterization of an in-vivo linear covalently closed DNA vector production system.

PubMed

Nafissi, Nafiseh; Slavcev, Roderick

2012-12-06

While safer than their viral counterparts, conventional non-viral gene delivery DNA vectors offer a limited safety profile. They often result in the delivery of unwanted prokaryotic sequences, antibiotic resistance genes, and the bacterial origins of replication to the target, which may lead to the stimulation of unwanted immunological responses due to their chimeric DNA composition. Such vectors may also impart the potential for chromosomal integration, thus potentiating oncogenesis. We sought to engineer an in vivo system for the quick and simple production of safer DNA vector alternatives that were devoid of non-transgene bacterial sequences and would lethally disrupt the host chromosome in the event of an unwanted vector integration event. We constructed a parent eukaryotic expression vector possessing a specialized manufactured multi-target site called "Super Sequence", and engineered E. coli cells (R-cell) that conditionally produce phage-derived recombinase Tel (PY54), TelN (N15), or Cre (P1). Passage of the parent plasmid vector through R-cells under optimized conditions, resulted in rapid, efficient, and one step in vivo generation of mini lcc--linear covalently closed (Tel/TelN-cell), or mini ccc--circular covalently closed (Cre-cell), DNA constructs, separated from the backbone plasmid DNA. Site-specific integration of lcc plasmids into the host chromosome resulted in chromosomal disruption and 10(5) fold lower viability than that seen with the ccc counterpart. We offer a high efficiency mini DNA vector production system that confers simple, rapid and scalable in vivo production of mini lcc DNA vectors that possess all the benefits of "minicircle" DNA vectors and virtually eliminate the potential for undesirable vector integration events.

The 3D printing of gelatin methacrylamide cell-laden tissue-engineered constructs with high cell viability.

PubMed

Billiet, Thomas; Gevaert, Elien; De Schryver, Thomas; Cornelissen, Maria; Dubruel, Peter

2014-01-01

In the present study, we report on the combined efforts of material chemistry, engineering and biology as a systemic approach for the fabrication of high viability 3D printed macroporous gelatin methacrylamide constructs. First, we propose the use and optimization of VA-086 as a photo-initiator with enhanced biocompatibility compared to the conventional Irgacure 2959. Second, a parametric study on the printing of gelatins was performed in order to characterize and compare construct architectures. Hereby, the influence of the hydrogel building block concentration, the printing temperature, the printing pressure, the printing speed, and the cell density were analyzed in depth. As a result, scaffolds could be designed having a 100% interconnected pore network in the gelatin concentration range of 10-20 w/v%. In the last part, the fabrication of cell-laden scaffolds was studied, whereby the application for tissue engineering was tested by encapsulation of the hepatocarcinoma cell line (HepG2). Printing pressure and needle shape was revealed to impact the overall cell viability. Mechanically stable cell-laden gelatin methacrylamide scaffolds with high cell viability (>97%) could be printed. Copyright © 2013 Elsevier Ltd. All rights reserved.

Differential eosinophil and mast cell regulation: Mast cell viability and accumulation in inflammatory tissue are independent of proton-sensing receptor GPR65

PubMed Central

Zhu, Xiang; Mose, Eucabeth; Hogan, Simon P.

2014-01-01

Extracellular acidification has been observed in allergic inflammatory diseases. Recently, we demonstrated that the proton-sensing receptor G protein-coupled receptor 65 (GPR65) regulates eosinophil survival in an acidic environment in vitro and eosinophil accumulation in an allergic lung inflammation model. For mast cells, another inflammatory cell type critical for allergic responses, it remains unknown whether GPR65 is expressed and/or regulates mast cell viability. Thus, in the present study, we employed in vitro experiments and an intestinal anaphylaxis model in which both mastocytosis and eosinophilia can be observed, particularly in the gastrointestinal tract, to enable us to directly compare the effect of GPR65 expression on these two cell types. We identified GPR65 expression on mast cells; however, unlike eosinophil viability, mast cell viability in vitro is not affected by acidification or GPR65 expression. Mechanistically, we determined that mast cells do not respond to extracellular acidification with increased cAMP levels. Furthermore, in the intestinal anaphylaxis model, we observed a significant reduction of eosinophils (59.1 ± 9.2% decrease) in the jejunum of allergen-challenged GPR65-deficient mice compared with allergen-challenged wild-type mice, despite the degree of antigen sensitization and the expression levels of Th2 cytokines (Il4, Il13) and eosinophil chemokines (Ccl11, Ccl24) in the jejunum being comparable. In contrast, the accumulation of mast cells in allergen-challenged mice was not affected by GPR65 deficiency. In conclusion, our study demonstrates differential regulation of eosinophils and mast cells in inflammatory tissue, with mast cell viability and accumulation being independent of GPR65. PMID:24742990

Long non-coding RNA HULC promotes UVB-induced injury by up-regulation of BNIP3 in keratinocytes.

PubMed

Zhao, Li; Man, Yigang; Liu, Shumei

2018-08-01

Ultraviolet radiation b (UVB) is a common high-energy radiation which can lead to cell damage and even skin cancer. The mechanisms of lncRNAs in various diseases have attracted much attention of researchers. Herein, we investigated the effects and regulations of lncRNA highly up-regulated in liver cancer (HULC) on UVB-induced injury in HaCaT cells. The HaCaT cells were exposed to UVB at a wavelength of 280-320 nm. Cell viability was detected at different times (0, 3, 6, 12 and 24 h) after UVB treatment. Cells were transfected with sh-HULC, pc-HULC, sh-BNIP3 (Bcl-2 interacting protein 3) or pc-BNIP3, respectively. ZM 39,923 HCl was used as JAK/STAT(1/3) inhibitor. Cell viability and apoptosis were tested by trypan blue dye and flow cytometry analysis, respectively. The expression levels of autophagy-related factors were analyzed by Western blot assay. The expression changes of HULC and BNIP3 were measured by qRT-PCR. We found that UVB decreased cell viability, increased apoptosis and autophagy, and up-regulated the expression of HULC in HaCaT cells. Overexpression of HULC reduced cell viability, enhanced apoptosis and autophagy, and up-regulated BNIP3 expression by activating JAK/STAT(1/3) signaling pathway. Finally, BNIP3 suppression increased cell viability, reduced apoptosis and autophagy via the deactivation of mTOR signaling pathway. The results demonstrated that lncRNA HULC up-regulated BNIP3 and activated JAK/STAT(1/3) signaling pathway to accelerate UVB-induced cell damage in HaCaT cells. This study provides a possible target for the clinical treatment of UVB-induced keratinocyte injury. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Effect of histone deacetylase inhibitor in combination with 5-fluorouracil on pancreas cancer and cholangiocarcinoma cell lines.

PubMed

Iwahashi, Shuichi; Ishibashi, Hiroki; Utsunomiya, Tohru; Morine, Yuji; Ochir, Tovuu Lkhaguva; Hanaoka, Jun; Mori, Hiroki; Ikemoto, Tetsuya; Imura, Satoru; Shimada, Mitsuo

2011-02-01

Histone deacetylase (HDAC) is well known to be associated with tumorigenesis through epigenetic regulation, and its inhibitors (HDACIs) induce differentiation and apoptosis of tumor cells. We examined the therapeutic effects of valproic acid (VPA, a HDACI) with a combination of 5-fluorouracil (5-FU) in vitro. A human pancreas cancer cell line (SUIT-2) and a cholangiocarcinoma cell line (HuCCT1) were used. Cell viabilities were evaluated by a cell proliferation assay. We determined the anticancer effects of VPA combined with 5-FU in these cell lines. Pancreas cancer (SUIT-2): No effect of 5-FU (1.0 µM) was observed, but 17% and 30% of proliferation-inhibitory effects were recognized in a dose of 2.5 or 5.0 µM, respectively. Cell viability was only weakly reduced by VPA (0.5 mM). However, in combination of 5-FU (1.0 µM) with VPA (0.5 mM), 19% of inhibitory effect was observed. Cholangiocarcinoma (HuCCT1): 5-FU (1.0 µM) did not suppress the cell viability, but 5-FU (2.5 µM) suppressed by 23%. VPA (0.5 mM) did not suppress the cell viability, while VPA (1.0 mM) weakly decreased it by 11%. Combination of 5-FU (1.0 µM) and VPA (0.5 mM) markedly reduced the cell viability by 30%. VPA augmented the anti-tumor effects of 5-FU in cancer cell lines. Therefore, a combination therapy of 5-FU plus VPA may be a promising therapeutic option for patients with pancreas cancer and cholangiocarcinoma.

siRNA - Mediated LRP/LR knock-down reduces cellular viability of malignant melanoma cells through the activation of apoptotic caspases.

PubMed

Rebelo, Thalia M; Vania, Leila; Ferreira, Eloise; Weiss, Stefan F T

2018-07-01

The 37 kDa/67 kDa laminin receptor (LRP/LR) is over-expressed in tumor cells and has been implicated in several tumourigenic processes such as metastasis and telomerase activation, however, more importantly the focus of the present study is on the maintenance of cellular viability and the evasion of apoptosis. The aim of the study was to investigate the role of LRP/LR on the cellular viability of early (A375) and late stage (A375SM) malignant melanoma cells. Flow cytometry and western blot analysis revealed that A375SM cells contain more cell-surface and total LRP/LR levels in comparison to the A375 cells, respectively. In order to determine the effect of LRP/LR on cell viability and apoptosis, LRP was down-regulated via siRNA technology. MTT assays revealed that LRP knock-down led to significant reductions in the viability of A375 and A375SM cells. Confocal microscopy indicated nuclear morphological changes suggestive of apoptotic induction in both cell lines and Annexin-V FITC/PI assays confirmed this observation. Additionally, caspase-3 activity assays revealed that apoptosis was induced in both cell lines after siRNA-mediated down-regulation of LRP. Caspase-8 and -9 activity assays suggested that post LRP knock-down; A375 cells undergo apoptosis solely via the extrinsic pathway, while A375SM cells undergo apoptosis via the intrinsic pathway. siRNAs mediated LRP knock-down might represent a powerful alternative therapeutic strategy for the treatment of malignant melanoma through the induction of apoptosis. Copyright © 2018. Published by Elsevier Inc.

Micro-RNA-181a suppresses progestin-promoted breast cancer cell growth.

PubMed

Gu, Muqing; Wang, Lijuan; Yang, Chun; Li, Xue; Jia, Chanwei; Croteau, Stephane; Ruan, Xiangyan; Hardy, Pierre

2018-08-01

Recent investigations have indicated that hormone therapy may increase the risk of breast cancer (BC), and the addition of synthetic progestins may play a critical role in this. Several studies have pointed out the important role of progesterone receptor membrane component 1 (PGRMC1) in the development of BC, especially with hormone therapy using progestins. Although the deregulation of microRNA-181a (miR-181a) is often associated with human BC, the effect of miR-181a on PGRMC1 expression during hormone therapy has not been investigated. Cell viability assay and apoptosis assay were performed to investigate the pro-BC effect of progestin (norethisterone, NET) and anti-BC effect of miR-181a on MCF-7 cells. Quantitative RT-PCR and Western blot analysis were used to evaluate gene expressions in the NET-treated MCF-7 cells. NET dose-dependently increased BC cell viability and this effect was accompanied by increased expression of PGRMC1. Overexpression of miR-181a strongly reduced the cell viability of MCF-7 cells, mainly through increased apoptosis, which was evidenced by substantially increased gene expression of pro-apoptosis factors such as BAX and CASPASE 9 in miR-181a overexpressed cells. Importantly, miR-181a abrogated NET-stimulated cell viability and PGRMC1 expression. We provide evidence that miR-181a promotes MCF-7 cell apoptosis. Moreover, miR-181a suppressed NET-provoked cell viability and PGRMC1 expression in MCF-7 cells. These data may suggest a therapeutic strategy of using miR-181a to reduce BC risk in progestin hormone replacement therapy. Copyright © 2018 Elsevier B.V. All rights reserved.

[Simultaneous staining with fluorescein diacetate-propidium iodide to determine isolated cochlear outer hair cell viability of guinea pig].

PubMed

Yu, Q; Shi, H; Wang, J

1995-01-01

A simultaneous double-staining procedure using fluorescein diacetate (FDA) and propidium iodide (PI) is discribed for use in the determination of isolated cochlear outer hair cell viability. With exciter light, viable cells fluoresce bright green, while nonviable cells are bright red. In cell culture and cytotoxicity studies, double-staining with FDA-PI is a accurate method to discriminate between live and nonviable cells.

Soilborne fungi have host affinity and host-specific effects on seed germination and survival in a lowland tropical forest.

PubMed

Sarmiento, Carolina; Zalamea, Paul-Camilo; Dalling, James W; Davis, Adam S; Stump, Simon M; U'Ren, Jana M; Arnold, A Elizabeth

2017-10-24

The Janzen-Connell (JC) hypothesis provides a conceptual framework for explaining the maintenance of tree diversity in tropical forests. Its central tenet-that recruits experience high mortality near conspecifics and at high densities-assumes a degree of host specialization in interactions between plants and natural enemies. Studies confirming JC effects have focused primarily on spatial distributions of seedlings and saplings, leaving major knowledge gaps regarding the fate of seeds in soil and the specificity of the soilborne fungi that are their most important antagonists. Here we use a common garden experiment in a lowland tropical forest in Panama to show that communities of seed-infecting fungi are structured predominantly by plant species, with only minor influences of factors such as local soil type, forest characteristics, or time in soil (1-12 months). Inoculation experiments confirmed that fungi affected seed viability and germination in a host-specific manner and that effects on seed viability preceded seedling emergence. Seeds are critical components of reproduction for tropical trees, and the factors influencing their persistence, survival, and germination shape the populations of seedlings and saplings on which current perspectives regarding forest dynamics are based. Together these findings bring seed dynamics to light in the context of the JC hypothesis, implicating them directly in the processes that have emerged as critical for diversity maintenance in species-rich tropical forests.

Soilborne fungi have host affinity and host-specific effects on seed germination and survival in a lowland tropical forest

PubMed Central

Dalling, James W.; Stump, Simon M.; U’Ren, Jana M.; Arnold, A. Elizabeth

2017-01-01

The Janzen–Connell (JC) hypothesis provides a conceptual framework for explaining the maintenance of tree diversity in tropical forests. Its central tenet—that recruits experience high mortality near conspecifics and at high densities—assumes a degree of host specialization in interactions between plants and natural enemies. Studies confirming JC effects have focused primarily on spatial distributions of seedlings and saplings, leaving major knowledge gaps regarding the fate of seeds in soil and the specificity of the soilborne fungi that are their most important antagonists. Here we use a common garden experiment in a lowland tropical forest in Panama to show that communities of seed-infecting fungi are structured predominantly by plant species, with only minor influences of factors such as local soil type, forest characteristics, or time in soil (1–12 months). Inoculation experiments confirmed that fungi affected seed viability and germination in a host-specific manner and that effects on seed viability preceded seedling emergence. Seeds are critical components of reproduction for tropical trees, and the factors influencing their persistence, survival, and germination shape the populations of seedlings and saplings on which current perspectives regarding forest dynamics are based. Together these findings bring seed dynamics to light in the context of the JC hypothesis, implicating them directly in the processes that have emerged as critical for diversity maintenance in species-rich tropical forests. PMID:28973927

Evaluation of transport conditions for autologous bone marrow-derived mesenchymal stromal cells for therapeutic application in horses

PubMed Central

Espina, Miguel; Jülke, Henriette; Brehm, Walter; Ribitsch, Iris; Winter, Karsten

2016-01-01

Background. Mesenchymal stromal cells (MSCs) are increasingly used for clinical applications in equine patients. For MSC isolation and expansion, a laboratory step is mandatory, after which the cells are sent back to the attending veterinarian. Preserving the biological properties of MSCs during this transport is paramount. The goal of the study was to compare transport-related parameters (transport container, media, temperature, time, cell concentration) that potentially influence characteristics of culture expanded equine MSCs. Methods. The study was arranged in three parts comparing (I) five different transport containers (cryotube, two types of plastic syringes, glass syringe, CellSeal), (II) seven different transport media, four temperatures (4 °C vs. room temperature; −20 °C vs. −80 °C), four time frames (24 h vs. 48 h; 48 h vs. 72 h), and (III) three MSC concentrations (5 × 106, 10 × 106, 20 × 106 MSC/ml). Cell viability (Trypan Blue exclusion; percent and total number viable cell), proliferation and trilineage differentiation capacity were assessed for each test condition. Further, the recovered volume of the suspension was determined in part I. Each condition was evaluated using samples of six horses (n = 6) and differentiation protocols were performed in duplicates. Results. In part I of the study, no significant differences in any of the parameters were found when comparing transport containers at room temperature. The glass syringe was selected for all subsequent evaluations (highest recoverable volume of cell suspension and cell viability). In part II, media, temperatures, or time frames had also no significant influence on cell viability, likely due to the large number of comparisons and small sample size. Highest cell viability was observed using autologous bone marrow supernatant as transport medium, and “transport” at 4 °C for 24 h (70.6% vs. control group 75.3%); this was not significant. Contrary, viability was unacceptably low (<40%) for all freezing protocols at −20 °C or −80 °C, particularly with bone marrow supernatant or plasma and DMSO. In part III, various cell concentrations also had no significant influence on any of the evaluated parameters. Chondrogenic differentiation showed a trend towards being decreased for all transport conditions, compared to control cells. Discussion. In this study, transport conditions were not found to impact viability, proliferation or ability for trilineage differentiation of MSCs, most likely due to the small sample size and large number of comparisons. The unusual low viability after all freezing protocols is in contrast to previous equine studies. Potential causes are differences in the freezing, but also in thawing method. Also, the selected container (glass syringe) may have impacted viability. Future research may be warranted into the possibly negative effect of transport on chondrogenic differentiation. PMID:27019778

Effects of aluminum in red spruce (Picea rubens) cell cultures: Cell growth and viability, mitochondrial activity, ultrastructure and potential sites of intracellular aluminum accumulation

Treesearch

Rakesh Minocha; Carolyn McQuattie; Wayne Fagerberg; Stephanie Long; Eun Woon Noh

2001-01-01

The effects of Al on red spruce (Picea rubens Sarg.) cell suspension cultures were examined using biochemical, stereo-logical and microscopic methods. Exposure to Al for 24-48 h resulted in a loss of cell viability, inhibition of growth and a significant decrease in mitochondrial activity. Soluble protein content increased in cells treated with Al....

Atomic force microscopic study of the influence of physical stresses on Saccharomyces cerevisiae and Schizosaccharomyces pombe.

PubMed

Adya, Ashok K; Canetta, Elisabetta; Walker, Graeme M

2006-01-01

Morphological changes in the cell surfaces of the budding yeast Saccharomyces cerevisiae (strain NCYC 1681), and the fission yeast Schizosaccharomyces pombe (strain DVPB 1354), in response to thermal and osmotic stresses, were investigated using an atomic force microscope. With this microscope imaging, together with measurements of culture viability and cell size, it was possible to relate topological changes of the cell surface at nanoscale with cellular stress physiology. As expected, when the yeasts were exposed to thermostress or osmostress, their viability together with the mean cell volume decreased in conjunction with the increase in thermal or osmotic shock. Nevertheless, the viability of cells stressed for up to 1 h remained relatively high. For example, viabilities were >50% and >90% for the thermostressed, and >60% and >70% for the osmostressed S. cerevisiae and Schiz. pombe, respectively. Mean cell volume measurements, and bearing and roughness analyses of atomic force microscope images of stressed yeasts indicate that Schiz. pombe may be more resistant to physical stresses than S. cerevisiae. Overall, this study has highlighted the usefulness of atomic force microscope in studies of yeast stress physiology.

Human Bone Marrow-Derived Mesenchymal Cell Reactions to 316L Stainless Steel: An in Vitro Study on Cell Viability and Interleukin-6 Expression.

PubMed

Anwar, Iwan Budiwan; Santoso, Asep; Saputra, Eko; Ismail, Rifky; Jamari, J; Van der Heide, Emile

2017-06-01

Purpose: Human bone marrow-derived mesenchymal cell (hBMC) reactions to 316L stainless steel (316L-SS) have never been evaluated. The objective of this study was to assess cell viability and interleukin-6 expression of hBMC cultures upon treatment with a 316L-SS implant. Methods: A cytotoxicity analysis was conducted with a 3-(4,5-dimethylthiazol 2-yl)-2,5-diphenyltetrazolium (MTT) assay after a period of 24, 48 and 72 hours of incubation. Expression of interleukin-6 was measured using enzyme-linked immunosorbent assay (ELISA). Results: Cell viability measurement was performed via IC50 formula. All treatment group showed a > 50 % cell viability with a range of 56,5 - 96,9 % at 24 hours, 51,8-77,3% at 48 hours and 70,1- 120 % at 72 hours. Interleukin-6 expression was downregulated subsequent to treatment with 316L-SS compared to the control group. Conclusion: We found that 316L-SS did not exhibit toxicity towards hBMC culture.

Human Bone Marrow-Derived Mesenchymal Cell Reactions to 316L Stainless Steel: An in Vitro Study on Cell Viability and Interleukin-6 Expression

PubMed Central

Anwar, Iwan Budiwan; Santoso, Asep; Saputra, Eko; Ismail, Rifky; Jamari, J.; Van der Heide, Emile

2017-01-01

Purpose: Human bone marrow-derived mesenchymal cell (hBMC) reactions to 316L stainless steel (316L-SS) have never been evaluated. The objective of this study was to assess cell viability and interleukin-6 expression of hBMC cultures upon treatment with a 316L-SS implant. Methods: A cytotoxicity analysis was conducted with a 3-(4,5-dimethylthiazol 2-yl)-2,5-diphenyltetrazolium (MTT) assay after a period of 24, 48 and 72 hours of incubation. Expression of interleukin-6 was measured using enzyme-linked immunosorbent assay (ELISA). Results: Cell viability measurement was performed via IC50 formula. All treatment group showed a > 50 % cell viability with a range of 56,5 - 96,9 % at 24 hours, 51,8-77,3% at 48 hours and 70,1- 120 % at 72 hours. Interleukin-6 expression was downregulated subsequent to treatment with 316L-SS compared to the control group. Conclusion: We found that 316L-SS did not exhibit toxicity towards hBMC culture. PMID:28761837

Sustaining fermentation in high-gravity ethanol production by feeding yeast to a temperature-profiled multifeed simultaneous saccharification and co-fermentation of wheat straw.

PubMed

Westman, Johan O; Wang, Ruifei; Novy, Vera; Franzén, Carl Johan

2017-01-01

Considerable progress is being made in ethanol production from lignocellulosic feedstocks by fermentation, but negative effects of inhibitors on fermenting microorganisms are still challenging. Feeding preadapted cells has shown positive effects by sustaining fermentation in high-gravity simultaneous saccharification and co-fermentation (SSCF). Loss of cell viability has been reported in several SSCF studies on different substrates and seems to be the main reason for the declining ethanol production toward the end of the process. Here, we investigate how the combination of yeast preadaptation and feeding, cell flocculation, and temperature reduction improves the cell viability in SSCF of steam pretreated wheat straw. More than 50% cell viability was lost during the first 24 h of high-gravity SSCF. No beneficial effects of adding selected nutrients were observed in shake flask SSCF. Ethanol concentrations greater than 50 g L -1 led to significant loss of viability and prevented further fermentation in SSCF. The benefits of feeding preadapted yeast cells were marginal at later stages of SSCF. Yeast flocculation did not improve the viability but simplified cell harvest and improved the feasibility of the cell feeding strategy in demo scale. Cultivation at 30 °C instead of 35 °C increased cell survival significantly on solid media containing ethanol and inhibitors. Similarly, in multifeed SSCF, cells maintained the viability and fermentation capacity when the temperature was reduced from 35 to 30 °C during the process, but hydrolysis yields were compromised. By combining the yeast feeding and temperature change, an ethanol concentration of 65 g L -1 , equivalent to 70% of the theoretical yield, was obtained in multifeed SSCF on pretreated wheat straw. In demo scale, the process with flocculating yeast and temperature profile resulted in 5% (w/w) ethanol, equivalent to 53% of the theoretical yield. Multifeed SSCF was further developed by means of a flocculating yeast and a temperature-reduction profile. Ethanol toxicity is intensified in the presence of lignocellulosic inhibitors at temperatures that are beneficial to hydrolysis in high-gravity SSCF. The counteracting effects of temperature on cell viability and hydrolysis call for more tolerant microorganisms, enzyme systems with lower temperature optimum, or full optimization of the multifeed strategy with temperature profile.

Prototheca zopfii Induced Ultrastructural Features Associated with Apoptosis in Bovine Mammary Epithelial Cells

PubMed Central

Shahid, Muhammad; Wang, Jianfang; Gu, Xiaolong; Chen, Wei; Ali, Tariq; Gao, Jian; Han, Dandan; Yang, Rui; Fanning, Séamus; Han, Bo

2017-01-01

Prototheca zopfii infections are becoming global concerns in humans and animals. Bovine protothecal mastitis is characterized by deteriorating milk quality and quantity, thus imparting huge economic losses to dairy industry. Previous published studies mostly focused on the prevalence and characterization of P. zopfii from mastitis. However, the ultrastructural pathomorphological changes associated with apoptosis in bovine mammary epithelial cells (bMECs) are not studied yet. Therefore, in this study we aimed to evaluate the in vitro comparative apoptotic potential of P. zopfii genotype-I and -II on bMECs using flow cytometry, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results showed fast growth rate and higher adhesion capability of genotype-II in bMECs as compared with genotype-I. The viability of bMECs infected with P. zopfii genotype-II was significantly decreased after 12 h (p < 0.05) and 24 h (p < 0.01) in comparison with control cells. Contrary, genotype-I couldn't show any significant effects on cell viability. Moreover, after infection of bMECs with genotype-II, the apoptosis increased significantly at 12 h (p < 0.05) and 24 h (p < 0.01) as compared with control group. Genotype-I couldn't display any significant effects on cell apoptosis. The host specificity of P. zopfii was also tested in mouse osteoblast cells, and the results suggest that genotype-I and -II could not cause any significant apoptosis in these cell lines. SEM interpreted the pathomorphological alterations in bMECs after infection. Adhesion of P. zopfii with cells and further disruption of cytomembrane validated the apoptosis caused by genotype-II under SEM. While genotype-1 couldn't cause any significant apoptosis in bMECs. Furthermore, genotype-II induced apoptotic manifested specific ultrastructure features, like cytoplasmic cavitation, swollen mitochondria, pyknosis, cytomembrane disruption, and appearance of apoptotic bodies under TEM. The findings of the current study revealed that genotype-II has the capability to invade and survive within the bMECs, thus imparting significant damages to the mammary cells which result in apoptosis. This study represents the first insights into the pathomorphological and ultrastructure features of apoptosis in bMECs induced by P. zopfii genotype-II. PMID:28752077

Ganoderma lucidum (Reishi) inhibits cancer cell growth and expression of key molecules in inflammatory breast cancer.

PubMed

Martínez-Montemayor, Michelle M; Acevedo, Raysa Rosario; Otero-Franqui, Elisa; Cubano, Luis A; Dharmawardhane, Suranganie F

2011-01-01

Inflammatory breast cancer (IBC) is the most lethal and least understood form of advanced breast cancer. Its lethality originates from its nature of invading the lymphatic system and absence of a palpable tumor mass. Different from other metastatic breast cancer cells, IBC cells invade by forming tumor spheroids that retain E-cadherin-based cell-cell adhesions. Herein we describe the potential of the medicinal mushroom Ganoderma lucidum (Reishi) as an attractive candidate for anti-IBC therapy. Reishi contains biological compounds that are cytotoxic against cancer cells. We report the effects of Reishi on viability, apoptosis, invasion, and its mechanism of action in IBC cells (SUM-149). Results show that Reishi selectively inhibits cancer cell viability although it does not affect the viability of noncancerous mammary epithelial cells. Apoptosis induction is consistent with decreased cell viability. Reishi inhibits cell invasion and disrupts the cell spheroids that are characteristic of the IBC invasive pathology. Reishi decreases the expression of genes involved in cancer cell survival and proliferation (BCL-2, TERT, PDGFB), and invasion and metastasis (MMP-9), whereas it increases the expression of IL8. Reishi reduces BCL-2, BCL-XL, E-cadherin, eIF4G, p120-catenin, and c-Myc protein expression and gelatinase activity. These findings suggest that Reishi is an effective anti-IBC therapeutic.

Three-Dimensional Cell Printing of Large-Volume Tissues: Application to Ear Regeneration.

PubMed

Lee, Jung-Seob; Kim, Byoung Soo; Seo, Donghwan; Park, Jeong Hun; Cho, Dong-Woo

2017-03-01

The three-dimensional (3D) printing of large-volume cells, printed in a clinically relevant size, is one of the most important challenges in the field of tissue engineering. However, few studies have reported the fabrication of large-volume cell-printed constructs (LCCs). To create LCCs, appropriate fabrication conditions should be established: Factors involved include fabrication time, residence time, and temperature control of the cell-laden hydrogel in the syringe to ensure high cell viability and functionality. The prolonged time required for 3D printing of LCCs can reduce cell viability and result in insufficient functionality of the construct, because the cells are exposed to a harsh environment during the printing process. In this regard, we present an advanced 3D cell-printing system composed of a clean air workstation, a humidifier, and a Peltier system, which provides a suitable printing environment for the production of LCCs with high cell viability. We confirmed that the advanced 3D cell-printing system was capable of providing enhanced printability of hydrogels and fabricating an ear-shaped LCC with high cell viability. In vivo results for the ear-shaped LCC also showed that printed chondrocytes proliferated sufficiently and differentiated into cartilage tissue. Thus, we conclude that the advanced 3D cell-printing system is a versatile tool to create cell-printed constructs for the generation of large-volume tissues.

Polyvinylpyrrolidone-Based Bio-Ink Improves Cell Viability and Homogeneity during Drop-On-Demand Printing

PubMed Central

Ng, Wei Long; Yeong, Wai Yee; Naing, May Win

2017-01-01

Drop-on-demand (DOD) bioprinting has attracted huge attention for numerous biological applications due to its precise control over material volume and deposition pattern in a contactless printing approach. 3D bioprinting is still an emerging field and more work is required to improve the viability and homogeneity of printed cells during the printing process. Here, a general purpose bio-ink was developed using polyvinylpyrrolidone (PVP) macromolecules. Different PVP-based bio-inks (0%–3% w/v) were prepared and evaluated for their printability; the short-term and long-term viability of the printed cells were first investigated. The Z value of a bio-ink determines its printability; it is the inverse of the Ohnesorge number (Oh), which is the ratio between the Reynolds number and a square root of the Weber number, and is independent of the bio-ink velocity. The viability of printed cells is dependent on the Z values of the bio-inks; the results indicated that the cells can be printed without any significant impairment using a bio-ink with a threshold Z value of ≤9.30 (2% and 2.5% w/v). Next, the cell output was evaluated over a period of 30 min. The results indicated that PVP molecules mitigate the cell adhesion and sedimentation during the printing process; the 2.5% w/v PVP bio-ink demonstrated the most consistent cell output over a period of 30 min. Hence, PVP macromolecules can play a critical role in improving the cell viability and homogeneity during the bioprinting process. PMID:28772551

Polyvinylpyrrolidone-Based Bio-Ink Improves Cell Viability and Homogeneity during Drop-On-Demand Printing.

PubMed

Ng, Wei Long; Yeong, Wai Yee; Naing, May Win

2017-02-16

Drop-on-demand (DOD) bioprinting has attracted huge attention for numerous biological applications due to its precise control over material volume and deposition pattern in a contactless printing approach. 3D bioprinting is still an emerging field and more work is required to improve the viability and homogeneity of printed cells during the printing process. Here, a general purpose bio-ink was developed using polyvinylpyrrolidone (PVP) macromolecules. Different PVP-based bio-inks (0%-3% w/v) were prepared and evaluated for their printability; the short-term and long-term viability of the printed cells were first investigated. The Z value of a bio-ink determines its printability; it is the inverse of the Ohnesorge number (Oh), which is the ratio between the Reynolds number and a square root of the Weber number, and is independent of the bio-ink velocity. The viability of printed cells is dependent on the Z values of the bio-inks; the results indicated that the cells can be printed without any significant impairment using a bio-ink with a threshold Z value of ≤9.30 (2% and 2.5% w/v). Next, the cell output was evaluated over a period of 30 min. The results indicated that PVP molecules mitigate the cell adhesion and sedimentation during the printing process; the 2.5% w/v PVP bio-ink demonstrated the most consistent cell output over a period of 30 min. Hence, PVP macromolecules can play a critical role in improving the cell viability and homogeneity during the bioprinting process.

Thermosensitive nanospheres with a gold layer revealed as low-cytotoxic drug vehicles.

PubMed

Qin, Jian; Jo, Yun Suk; Ihm, Jong Eun; Kim, Do Kyung; Muhammed, Mamoun

2005-09-27

In this paper, the positive effect of a gold layer on cell viability is demonstrated by examining the results given by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfop henyl)-2H-tetrazolium (MTS) assay and two-color cell fluorescence viability (TCCV) assay. These cytotoxicity tests were performed with human cervical adenocarcinoma cells (HeLa cell line) and transformed African green monkey kidney fibroblast cells (Cos-7 cell line). To fabricate the nanostructures as drug vehicles, first, poly(l,l-lactide-co-ethylene glycol) (PLLA-PEG) and poly(N-isopropylacrylamide-co-D,D-lactide) (PNIPAAm-PDLA) were synthesized, and then two kinds of thermosensitive nanospheres comprising "shell-in-shell" structures without a gold layer (PLLA-PEG@PNIPAAm-PDLA) and with a gold layer (Au@PLLA-PEG@PNIPAAm-PDLA) were constructed by a modified double-emulsion method (MDEM). Both of them displayed a unique thermosensitive character exhibiting the lower critical solubility temperature (LCST) at 36.7 degrees C which was confirmed by UV-vis spectroscopy and differential scanning calorimetry (DSC). The release profiles of entrapped bovine serum albumin (BSA) were monitored at 22 and 37 degrees C, respectively, to reveal the thermal dependence on the release rate. In cell viability tests, both PLLA-PEG@PNIPAAm-PDLA and Au@PLLA-PEG@PNIPAAm-PDLA showed excellent cell viability, and furthermore, Au@PLLA-PEG@PNIPAAm-PDLA, particularly at high doses, exhibited more enhanced cell viability than PLLA-PEG@PNIPAAm-PDLA. This effect is mainly attributed to the gold layer which binds the protein molecules first and consequently facilitates transmembrane uptake of essential nutrients in the cell media, resulting in favorable cell proliferation.

Angle-ply biomaterial scaffold for annulus fibrosus repair replicates native tissue mechanical properties, restores spinal kinematics, and supports cell viability.

PubMed

Borem, Ryan; Madeline, Allison; Walters, Joshua; Mayo, Henry; Gill, Sanjitpal; Mercuri, Jeremy

2017-08-01

Annulus fibrosus (AF) damage commonly occurs due to intervertebral disc (IVD) degeneration/herniation. The dynamic mechanical role of the AF is essential for proper IVD function and thus it is imperative that biomaterials developed to repair the AF withstand the mechanical rigors of the native tissue. Furthermore, these biomaterials must resist accelerated degradation within the proteolytic environment of degenerate IVDs while supporting integration with host tissue. We have previously reported a novel approach for developing collagen-based, multi-laminate AF repair patches (AFRPs) that mimic the angle-ply architecture and basic tensile properties of the human AF. Herein, we further evaluate AFRPs for their: tensile fatigue and impact burst strength, IVD attachment strength, and contribution to functional spinal unit (FSU) kinematics following IVD repair. Additionally, AFRP resistance to collagenase degradation and cytocompatibility were assessed following chemical crosslinking. In summary, AFRPs demonstrated enhanced durability at high applied stress amplitudes compared to human AF and withstood radially-directed biaxial stresses commonly borne by the native tissue prior to failure/detachment from IVDs. Moreover, FSUs repaired with AFRPs and nucleus pulposus (NP) surrogates had their axial kinematic parameters restored to intact levels. Finally, carbodiimide crosslinked AFRPs resisted accelerated collagenase digestion without detrimentally effecting AFRP tensile properties or cytocompatibility. Taken together, AFRPs demonstrate the mechanical robustness and enzymatic stability required for implantation into the damaged/degenerate IVD while supporting AF cell infiltration and viability. The quality of life for millions of individuals globally is detrimentally impacted by IVD degeneration and herniation. These pathologies often result in the structural demise of IVD tissue, particularly the annulus fibrosus (AF). Biomaterials developed for AF repair have yet to demonstrate the mechanical strength and durability required for utilization in the spine. Herein, we demonstrate the development of an angle-ply AF repair patch (AFRP) that can resist the application of physiologically relevant stresses without failure and which contributes to the restoration of functional spinal unit axial kinematics following repair. Furthermore, we show that this biomaterial can resist accelerated degradation in a simulated degenerate environment and supports AF cell viability. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

ATM Is Required for the Prolactin-Induced HSP90-Mediated Increase in Cellular Viability and Clonogenic Growth After DNA Damage.

PubMed

Karayazi Atici, Ödül; Urbanska, Anna; Gopinathan, Sesha Gopal; Boutillon, Florence; Goffin, Vincent; Shemanko, Carrie S

2018-02-01

Prolactin (PRL) acts as a survival factor for breast cancer cells, but the PRL signaling pathway and the mechanism are unknown. Previously, we identified the master chaperone, heat shock protein 90 (HSP90) α, as a prolactin-Janus kinase 2 (JAK2)-signal transducer and activator of transcription 5 (STAT5) target gene involved in survival, and here we investigated the role of HSP90 in the mechanism of PRL-induced viability in response to DNA damage. The ataxia-telangiectasia mutated kinase (ATM) protein plays a critical role in the cellular response to double-strand DNA damage. We observed that PRL increased viability of breast cancer cells treated with doxorubicin or etoposide. The increase in cellular resistance is specific to the PRL receptor, because the PRL receptor antagonist, Δ1-9-G129R-hPRL, prevented the increase in viability. Two different HSP90 inhibitors, 17-allylamino-17-demethoxygeldanamycin and BIIB021, reduced the PRL-mediated increase in cell viability of doxorubicin-treated cells and led to a decrease in JAK2, ATM, and phosphorylated ATM protein levels. Inhibitors of JAK2 (G6) and ATM (KU55933) abolished the PRL-mediated increase in cell viability of DNA-damaged cells, supporting the involvement of each, as well as the crosstalk of ATM with the PRL pathway in the context of DNA damage. Drug synergism was detected between the ATM inhibitor (KU55933) and doxorubicin and between the HSP90 inhibitor (BIIB021) and doxorubicin. Short interfering RNA directed against ATM prevented the PRL-mediated increase in cell survival in two-dimensional cell culture, three-dimensional collagen gel cultures, and clonogenic cell survival, after doxorubicin treatment. Our results indicate that ATM contributes to the PRL-JAK2-STAT5-HSP90 pathway in mediating cellular resistance to DNA-damaging agents. Copyright © 2018 Endocrine Society.

Evaluation of Commercial-off-the-Shelf Materials for the Preservation of Bacillus anthracis Vegetative Cells for Forensic Analysis.

PubMed

Angelini, Daniel J; Harris, Jacquelyn V; Burton, Laura L; Rastogi, Pooja R; Smith, Lisa S; Rastogi, Vipin K

2018-03-01

Environmental surface sampling is crucial in determining the zones of contamination and overall threat assessment. Viability retention of sampled material is central to such assessments. A systematic study was completed to determine viability of vegetative cells under nonpermissive storage conditions. Despite major gains in nucleic acid sequencing technologies, initial positive identification of threats must be made through direct culture of the sampled material using classical microbiological methods. Solutions have been developed to preserve the viability of pathogens contained within clinical samples, but many have not been examined for their ability to preserve biological agents. The purpose of this study was to systematically examine existing preservation materials that can retain the viability of Bacillus anthracis vegetative cells stored under nonpermissive temperatures. The results show effectiveness of five of seventeen solutions, which are capable of retaining viability of a sporulation deficient strain of B. anthracis Sterne when stored under nonrefrigerated conditions. © 2017 American Academy of Forensic Sciences.

Effects of tocotrienols on cell viability and apoptosis in normal murine liver cells (BNL CL.2) and liver cancer cells (BNL 1ME A.7R.1), in vitro.

PubMed

Har, Chan Hooi; Keong, Chan Kok

2005-01-01

The effects of tocotrienols on murine liver cell viability and their apoptotic events were studied over a dose range of 0-32 microg mL(-1). Normal murine liver cells (BNL CL.2) and murine liver cancer cells (BNL 1ME A.7R.1) were treated with tocotrienols (T(3)), alpha tocopherol (alpha-T) and the chemo drug, Doxorubicin (Doxo, as a positive control). Cell viability assay showed that T(3) significantly (P < or = 0.05) lowered the percentage of BNL 1ME A.7R.1 cell viability in a dose-responsive manner (8-16 microg mL(-1)), whereas T did not show any significant (P>0.05) inhibition in cell viability with increasing treatment doses of 0-16 microg mL(-1). The IC(50) for tocotrienols were 9.8, 8.9, 8.1, 9.7, 8.1 and 9.3 microg mL(-1) at 12, 24, 36, 48, 60 and 72 hours respectively. Early apoptosis was detected 6 hours following T(3) treatment of BNL 1ME A.7R.1 liver cancer cells, using Annexin V-FITC fluorescence microscopy assay for apoptosis, but none were observed for the non-treated liver cancer cells at the average IC(50) of 8.98 microg mL(-1) tocotrienols for liver cancer cells. Several apoptotic bodies were detected in BNL 1ME A.7R.1 liver cancer cells at 6 hours post-treatment with tocotrienols (8.98 microg mL(-1)) using Acridine Orange/Propidium Iodide fluorescence assay. However, only a couple of apoptotic bodies were seen in the non-treated liver cancer cells and the BNL CL.2 normal liver cells. Some mitotic bodies were also observed in the T(3)-treated BNL 1ME A.7R.1 liver cancer cells but were not seen in the untreated BNL 1ME A.7R.1 cells and the BNL CL.2 liver cells. Following T(3)-treatment (8.98 microg mL(-1)) of the BNL 1ME A.7R.1 liver cancer cells, 24.62%, 25.53% and 44.90% of the cells showed elevated active caspase 3 activity at 9, 12 and 24 hours treatment period, respectively. DNA laddering studies indicated DNA fragmentation occurred in the T(3)-treated liver cancer cells, BNL 1ME A.7R.1 but not in non-treated liver cancer cells and the T(3)-treated and non-treated normal liver cells. These results suggest that tocotrienols were able to reduce the cell viability in the murine liver cancer cells at a dose of 8-32 microg mL(-1) and that this decrease in percentage cell viability may be due to apoptosis.

Involvement of TRPV1 and AQP2 in hypertonic stress by xylitol in odontoblast cells.

PubMed

Tokuda, M; Fujisawa, M; Miyashita, K; Kawakami, Y; Morimoto-Yamashita, Y; Torii, M

2015-02-01

To examine the responses of mouse odontoblast-lineage cell line (OLC) cultures to xylitol-induced hypertonic stress. OLCs were treated with xylitol, sucrose, sorbitol, mannitol, arabinose and lyxose. Cell viability was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium assay. The expression of transient receptor potential vanilloids (TRPV) 1, 3 and 4 was detected using a reverse transcriptase-polymerase chain reaction (RT-PCR) assay. The expression of aquaporin (AQP) 2 was detected using immunofluorescence and Western blotting analysis. The expression of interleukin-6 (IL-6) under xylitol-induced hypertonic stress was assessed using an enzyme-linked immunosorbent assay (ELISA). Small interfering ribonucleic acid (siRNA) for AQP-2 was used to inhibition assay. Xylitol-induced hypertonic stress did not decrease OLC viability, unlike the other sugars tested. OLCs expressed TRPV1, 3 and 4 as well as AQP2. Xylitol inhibited lipopolysaccharide (LPS)-induced IL-6 expression after 3 h of hypertonic stress. TRPV1 mRNA expression was upregulated by xylitol. Costimulation with HgCl2 (AQP inhibitor) and Ruthenium red (TRPV1 inhibitor) decreased cell viability with xylitol stimulation. OLCs treated with siRNA against TRPV1 exhibited decreased cell viability with xylitol stimulation. OLCs have high-cell viability under xylitol-induced hypertonic stress, which may be associated with TRPV1 and AQP2 expressions.

Neuroprotective effect of astaxanthin against rat retinal ganglion cell death under various stresses that induce apoptosis and necrosis.

PubMed

Yamagishi, Reiko; Aihara, Makoto

2014-01-01

Astaxanthin is a type of carotenoid known to have strong antioxidant effects. The purpose of this study was to investigate whether astaxanthin confers a neuroprotective effect against glutamate stress, oxidative stress, and hypoxia-induced apoptotic or necrotic cell death in primary cultures of rat retinal ganglion cells (RGCs). Purified rat RGCs were exposed to three kinds of stressors induced by 25 μM glutamate for 72 h, B27 medium without an antioxidant for 4 h, and a reduced oxygen level of 5% for 12 h. Each assay was repeated 12 times, with or without 1 nM, 10 nM, and 100 nM astaxanthin. The number of live RGCs was then counted using a cell viability assay. RGC viability in each condition was evaluated and compared with controls. In addition, we measured apoptosis and DNA damage. We found that under glutamate stress, RGC viability was reduced to 58%. Cultures with 1 nM, 10 nM, and 100 nM astaxanthin showed an increase in RGC viability of 63%, 74%, and 84%, respectively. Under oxidative stress, RGC viability was reduced to 40%, and astaxanthin administration resulted in increased viability of 43%, 50%, and 67%, respectively. Under hypoxia, RGC viability was reduced to 66%, and astaxanthin administration resulted in a significant increase in viability to 67%, 77%, and 93%, respectively. These results indicate that 100 nM astaxanthin leads to a statistically significant increase in RGC viability under the three kinds of stressors tested, compared to controls (Dunnett's test, p<0.05). The apoptotic activity of RGCs under glutamate stress increased to 32%, but was reduced to 15% with 100 nM astaxanthin administration. Glutamate stress led to a 58% increase in DNA damage, which was reduced to 43% when cultured with 100 nM astaxanthin. Thus, 100 nM astaxanthin showed a statistically significant reduction in apoptosis and DNA damage in RGCs (Wilcoxon rank-sum test, p<0.05). Our results suggest that astaxanthin has a neuroprotective effect against RGC death induced by glutamate stress, oxidative stress, and hypoxia, which induce apoptotic and necrotic cell death.

Placenta‐Derived Decidua Stromal Cells for Treatment of Severe Acute Graft‐Versus‐Host Disease

PubMed Central

Baygan, Arjang; Remberger, Mats; Gustafsson, Britt; Winiarski, Jacek; Khoein, Bita; Moll, Guido; Klingspor, Lena; Westgren, Magnus; Sadeghi, Behnam

2018-01-01

Abstract Severe acute graft‐versus‐host disease (GVHD) is a life‐threatening complication after allogeneic hematopoietic stem cell transplantation (HSCT). The placenta protects the fetus from the mother's immune system. We evaluated placenta‐derived decidua stromal cells (DSCs), which differ from bone marrow mesenchymal stromal cells (BM‐MSCs), as a treatment for severe acute GVHD. DSCs were obtained from term placentas. The DSCs were given to 38 patients with severe acute GVHD; 25 were steroid refractory (SR). DSCs were thawed and infused in buffer supplemented with either 10% AB plasma (group 1, n = 17), or 5% albumin (group 2, n = 21). The viability of cells was higher when thawed in albumin rather than AB plasma (p < .001). Group 1 received a higher cell dose (p < .001), cells of lower passage number (p < .001), and fewer infusions (p = .002) than group 2. The GVHD response (no/partial/complete) was 7/5/5 in group 1 and 0/10/11 in group 2 (p = .01). One‐year survival in the two groups was 47% (95% confidence interval [CI] 23–68) and 76% (95% CI 51–89), respectively (p = .016). For the SR patients, 1‐year survival was 73% (95% CI 37–90) in SR group 2 (n = 11), which was better than 31% (95% CI 11–54) in SR group 1 (n = 13; p = .02), 20% (95% CI 5–42) in BM‐MSC treated (n = 15; p = .0015), and 3% (95% CI 0–14) in historic controls (n = 32; p < .001). DSCs are a promising new treatment for severe acute GVHD. Prospective randomized trials are needed for evaluation of efficacy. (Clinical trial NCT‐02172937.) stem cells translational medicine 2018;7:325–332 PMID:29533533

Supercooling as a Viable Non-Freezing Cell Preservation Method of Rat Hepatocytes

PubMed Central

Usta, O. Berk; Kim, Yeonhee; Ozer, Sinan; Bruinsma, Bote G.; Lee, Jungwoo; Demir, Esin; Berendsen, Tim A.; Puts, Catheleyne F.; Izamis, Maria-Louisa; Uygun, Korkut; Uygun, Basak E.; Yarmush, Martin L.

2013-01-01

Supercooling preservation holds the potential to drastically extend the preservation time of organs, tissues and engineered tissue products, and fragile cell types that do not lend themselves well to cryopreservation or vitrification. Here, we investigate the effects of supercooling preservation (SCP at -4oC) on primary rat hepatocytes stored in cryovials and compare its success (high viability and good functional characteristics) to that of static cold storage (CS at +4oC) and cryopreservation. We consider two prominent preservation solutions a) Hypothermosol (HTS-FRS) and b) University of Wisconsin solution (UW) and a range of preservation temperatures (-4 to -10 oC). We find that there exists an optimum temperature (-4oC) for SCP of rat hepatocytes which yields the highest viability; at this temperature HTS-FRS significantly outperforms UW solution in terms of viability and functional characteristics (secretions and enzymatic activity in suspension and plate culture). With the HTS-FRS solution we show that the cells can be stored for up to a week with high viability (~56%); moreover we also show that the preservation can be performed in large batches (50 million cells) with equal or better viability and no loss of functionality as compared to smaller batches (1.5 million cells) performed in cryovials. PMID:23874947

Ganoderma lucidum (Reishi) Inhibits Cancer Cell Growth and Expression of Key Molecules in Inflammatory Breast Cancer

PubMed Central

Martínez-Montemayor, Michelle M.; Acevedo, Raysa Rosario; Otero-Franqui, Elisa; Cubano, Luis. A.; Dharmawardhane, Suranganie F.

2011-01-01

Inflammatory breast cancer (IBC) is the most lethal and least understood form of advanced breast cancer. Its lethality originates from its nature of invading the lymphatic system and absence of a palpable tumor mass. Different from other metastatic breast cancer cells, IBC cells invade by forming tumor spheroids that retain E-cadherin-based cell–cell adhesions. Herein we describe the potential of the medicinal mushroom Ganoderma lucidum (Reishi) as an attractive candidate for anti-IBC therapy. Reishi contains biological compounds that are cytotoxic against cancer cells. We report the effects of Reishi on viability, apoptosis, invasion, and its mechanism of action in IBC cells (SUM-149). Results show that Reishi selectively inhibits cancer cell viability although it does not affect the viability of noncancerous mammary epithelial cells. Apoptosis induction is consistent with decreased cell viability. Reishi inhibits cell invasion and disrupts the cell spheroids that are characteristic of the IBC invasive pathology. Reishi decreases the expression of genes involved in cancer cell survival and proliferation (BCL-2, TERT, PDGFB), and invasion and metastasis (MMP-9), whereas it increases the expression of IL8. Reishi reduces BCL-2, BCL-XL, E-cadherin, eIF4G, p120-catenin, and c-Myc protein expression and gelatinase activity. These findings suggest that Reishi is an effective anti-IBC therapeutic. PMID:21888505

Successful isolation of viable adipose-derived stem cells from human adipose tissue subject to long-term cryopreservation: positive implications for adult stem cell-based therapeutics in patients of advanced age.

PubMed

Devitt, Sean M; Carter, Cynthia M; Dierov, Raia; Weiss, Scott; Gersch, Robert P; Percec, Ivona

2015-01-01

We examined cell isolation, viability, and growth in adipose-derived stem cells harvested from whole adipose tissue subject to different cryopreservation lengths (2-1159 days) from patients of varying ages (26-62 years). Subcutaneous abdominal adipose tissue was excised during abdominoplasties and was cryopreserved. The viability and number of adipose-derived stem cells isolated were measured after initial isolation and after 9, 18, and 28 days of growth. Data were analyzed with respect to cryopreservation duration and patient age. Significantly more viable cells were initially isolated from tissue cryopreserved <1 year than from tissue cryopreserved >2 years, irrespective of patient age. However, this difference did not persist with continued growth and there were no significant differences in cell viability or growth at subsequent time points with respect to cryopreservation duration or patient age. Mesenchymal stem cell markers were maintained in all cohorts tested throughout the duration of the study. Consequently, longer cryopreservation negatively impacts initial live adipose-derived stem cell isolation; however, this effect is neutralized with continued cell growth. Patient age does not significantly impact stem cell isolation, viability, or growth. Cryopreservation of adipose tissue is an effective long-term banking method for isolation of adipose-derived stem cells in patients of varying ages.

Two-dimensional and three-dimensional viability measurements of adult stem cells with optical coherence phase microscopy

NASA Astrophysics Data System (ADS)

Bagnaninchi, Pierre O.; Holmes, Christina; Drummond, Nicola; Daoud, Jamal; Tabrizian, Maryam

2011-08-01

Cell viability assays are essential tools for cell biology. They assess healthy cells in a sample and enable the quantification of cellular responses to reagents of interest. Noninvasive and label-free assays are desirable in two-dimensional (2D) and three-dimensional (3D) cell culture to facilitate time-course viability studies. Cellular micromotion, emanating from cell to substrate distance variations, has been demonstrated as a marker of cell viability with electric cell-substrate impedance sensing (ECIS). In this study we investigated if optical coherence phase microscopy (OCPM) was able to report phase fluctuations of adult stem cells in 2D and 3D that could be associated with cellular micromotion. An OCPM has been developed around a Thorlabs engine (λo = 930 nm) and integrated in an inverted microscope with a custom scanning head. Human adipose derived stem cells (ADSCs, Invitrogen) were cultured in Mesenpro RS medium and seeded either on ECIS arrays, 2D cell culture dishes, or in 3D highly porous microplotted polymeric scaffolds. ADSC micromotion was confirmed by ECIS analysis. Live and fixed ADSCs were then investigated in 2D and 3D with OCPM. Significant differences were found in phase fluctuations between the different conditions. This study indicated that OCPM could potentially assess cell vitality in 2D and in 3D microstructures.

Performance and biocompatibility of extremely tough alginate/polyacrylamide hydrogels.

PubMed

Darnell, Max C; Sun, Jeong-Yun; Mehta, Manav; Johnson, Christopher; Arany, Praveen R; Suo, Zhigang; Mooney, David J

2013-11-01

Although hydrogels now see widespread use in a host of applications, low fracture toughness and brittleness have limited their more broad use. As a recently described interpenetrating network (IPN) of alginate and polyacrylamide demonstrated a fracture toughness of ≈ 9000 J/m(2), we sought to explore the biocompatibility and maintenance of mechanical properties of these hydrogels in cell culture and in vivo conditions. These hydrogels can sustain a compressive strain of over 90% with minimal loss of Young's Modulus as well as minimal swelling for up to 50 days of soaking in culture conditions. Mouse mesenchymal stem cells exposed to the IPN gel-conditioned media maintain high viability, and although cells exposed to conditioned media demonstrate slight reductions in proliferation and metabolic activity (WST assay), these effects are abrogated in a dose-dependent manner. Implantation of these IPN hydrogels into subcutaneous tissue of rats for 8 weeks led to mild fibrotic encapsulation and minimal inflammatory response. These results suggest the further exploration of extremely tough alginate/PAAM IPN hydrogels as biomaterials. © 2013 Elsevier Ltd. All rights reserved.

Apoptosis is an innate defense function of macrophages against Mycobacterium tuberculosis

PubMed Central

Behar, SM; Martin, CJ; Booty, MG; Nishimura, T; Zhao, X; Gan, H; Divangahi, M; Remold, HG

2011-01-01

Two different forms of death are commonly observed when Mycobacterium tuberculosis (Mtb)-infected macrophages die: (i) necrosis, a death modality defined by cell lysis and (ii) apoptosis, a form of death that maintains an intact plasma membrane. Necrosis is a mechanism used by bacteria to exit the macrophage, evade host defenses, and spread. In contrast, apoptosis of infected macrophages is associated with diminished pathogen viability. Apoptosis occurs when tumor necrosis factor activates the extrinsic death domain pathway, leading to caspase-8 activation. In addition, mitochondrial outer membrane permeabilization leading to activation of the intrinsic apoptotic pathway is required. Both pathways lead to caspase-3 activation, which results in apoptosis. We have recently demonstrated that during mycobacterial infection, cell death is regulated by the eicosanoids, prostaglandin E2 (proapoptotic) and lipoxin (LX)A4 (pronecrotic). Although PGE2 protects against necrosis, virulent Mtb induces LXA4 and inhibits PGE2 production. Under such conditions, mitochondrial inner membrane damage leads to macrophage necrosis. Thus, virulent Mtb subverts eicosanoid regulation of cell death to foil innate defense mechanisms of the macrophage. PMID:21307848

Apoptosis is an innate defense function of macrophages against Mycobacterium tuberculosis.

PubMed

Behar, S M; Martin, C J; Booty, M G; Nishimura, T; Zhao, X; Gan, H-X; Divangahi, M; Remold, H G

2011-05-01

Two different forms of death are commonly observed when Mycobacterium tuberculosis (Mtb)-infected macrophages die: (i) necrosis, a death modality defined by cell lysis and (ii) apoptosis, a form of death that maintains an intact plasma membrane. Necrosis is a mechanism used by bacteria to exit the macrophage, evade host defenses, and spread. In contrast, apoptosis of infected macrophages is associated with diminished pathogen viability. Apoptosis occurs when tumor necrosis factor activates the extrinsic death domain pathway, leading to caspase-8 activation. In addition, mitochondrial outer membrane permeabilization leading to activation of the intrinsic apoptotic pathway is required. Both pathways lead to caspase-3 activation, which results in apoptosis. We have recently demonstrated that during mycobacterial infection, cell death is regulated by the eicosanoids, prostaglandin E(2) (proapoptotic) and lipoxin (LX)A(4) (pronecrotic). Although PGE(2) protects against necrosis, virulent Mtb induces LXA(4) and inhibits PGE(2) production. Under such conditions, mitochondrial inner membrane damage leads to macrophage necrosis. Thus, virulent Mtb subverts eicosanoid regulation of cell death to foil innate defense mechanisms of the macrophage.

The reducibility of heLa cell viability by Sargassum polycystum extracts

NASA Astrophysics Data System (ADS)

Firdaus, M.; Setijawati, D.; Islam, I.; Nursyam, H.; Kartikaningsih, H.; Yufidasari, H. S.; Prihanto, A. A.; Nurdiani, R.; Jaziri, A. A.

2018-04-01

Cervical cancer is the second largest cause of death-related cancer in women. The efficacy of cancer drugs is still low. Bioactive of brown seaweed has been studied by in vitro and in vivo as anticancer. The aim of this study was to evaluate the cytotoxicity of Sargassum polycystum extracts on HeLa cell, to recognize bioactive on extract and estimate the interaction between the bioactive and target protein. S. polycystum was found from Talango Island waters and HeLa cell was obtained from Indonesian Science Institute. Sample was extracted by ethanol, ethyl acetate and hexane, concentrated and finally, extracts were assayed on HeLa cell. The viability of this cell was quantified on ELISA-Reader. The bioactive compounds of the extract were elucidated by GC-MS. The interaction between bioactive and target protein was evaluated by using in silico method. The result showed that the lowest viability of HeLa cell on n-hexane extracts treatment. The n-hexane extract of this seaweed contained benzenepropanoic acid. This compound reduced HeLa cell viability by reducing of thrombin concentration. In conclusion, the benzene propanoic acid of S. polycystum was the cytotoxic agent and it is potential agent for anti-cervical cancer.

Cross-link regulation of precursor N-cadherin and FGFR1 by GDNF increases U251MG cell viability.

PubMed

Tang, Chuan-Xi; Gu, Yan-Xia; Liu, Xin-Feng; Tong, Shu-Yan; Ayanlaja, Abiola A; Gao, Yue; Ji, Guang-Quan; Xiong, Ye; Huang, Lin-Yan; Gao, Dian-Shuai

2018-07-01

Glial cell line-derived neurotrophic factor (GDNF) is considered to be involved in the development of glioma. However, uncovering the underlying mechanism of the proliferation of glioma cells is a challenging work in progress. We have identified the binding of the precursor of N-cadherin (proN-cadherin) and GDNF on the cell membrane in previous studies. In the present study, we observed increased U251 Malignant glioma (U251MG) cell viability by exogenous GDNF (50 ng/ml). We also confirmed that the high expression of the proN-cadherin was stimulated by exogenous GDNF. Concurrently, we affirmed that lower expression of proN-cadherin correlated with reduced glioma cell viability. Additionally, we observed glioma cell U251MG viability as the phosphorylation level of FGFR1 at Y653 and Y654 was increased after exogenous GDNF treatment, which led to increased interaction between proN-cadherin and FGFR1 (pY653+Y654). Our experiments presented a new mechanism adopted by GDNF supporting glioma development and indicated a possible therapeutic potential via the inhibition of proN-cadherin/FGFR1 interaction.

Echinococcus metacestode: in search of viability markers.

PubMed

Gottstein, Bruno; Wang, Junhua; Blagosklonov, Oleg; Grenouillet, Frédéric; Millon, Laurence; Vuitton, Dominique A; Müller, Norbert

2014-01-01

Epidemiological studies have demonstrated that most humans infected with Echinococcus spp. exhibit resistance to disease. When infection leads to disease, the parasite is partially controlled by host immunity: in case of immunocompetence, the normal alveolar echinococcosis (AE) or cystic echinococcosis (CE) situation, the metacestode grows slowly, and first clinical signs appear years after infection; in case of impaired immunity (AIDS; other immunodeficiencies), uncontrolled proliferation of the metacestode leads to rapidly progressing disease. Assessing Echinococcus multilocularis viability in vivo following therapeutic interventions in AE patients may be of tremendous benefit when compared with the invasive procedures used to perform biopsies. Current options are F18-fluorodeoxyglucose-positron emission tomography (FDG-PET), which visualizes periparasitic inflammation due to the metabolic activity of the metacestode, and measurement of antibodies against recEm18, a viability-associated protein, that rapidly regresses upon metacestode inactivation. For Echinococcus granulosus, similar prognosis-associated follow-up parameters are still lacking but a few candidates may be listed. Other possible markers include functional and diffusion-weighted Magnetic Resonance Imaging (MRI), and measurement of products from the parasite (circulating antigens or DNA), and from the host (inflammation markers, cytokines, or chemokines). Even though some of them have been promising in pilot studies, none has been properly validated in an appropriate number of patients until now to be recommended for further use in clinical settings. There is therefore still a need to develop reliable tools for improved viability assessment to provide the sufficient information needed to reliably withdraw anti-parasite benzimidazole chemotherapy, and a basis for the development of new alternative therapeutic tools. © B. Gottstein et al., published by EDP Sciences, 2014.

Effects of ozone exposure on human epithelial adenocarcinoma and normal fibroblasts cells.

PubMed

Poma, Anna; Colafarina, Sabrina; Aruffo, Eleonora; Zarivi, Osvaldo; Bonfigli, Antonella; Di Bucchianico, Sebastiano; Di Carlo, Piero

2017-01-01

Previous studies show variable ozone cytotoxicity and genotoxicity in cell cultures, laboratory animals and humans directly exposed to tropospheric ozone. The aim of this study was therefore to investigate and compare the cyto and genotoxic effects of ozone using adenocarcinoma human alveolar basal epithelial cells A549 and normal human fibroblasts Hs27. A cell culture chamber with controlled atmosphere (a simulation reactor) was built to inject a flow of 120 ppb of ozone, which is two times the threshold value for the protection of human health, fixed by the EU legislation. Cell proliferation was evaluated by a luminescent cell viability assay while we assessed the genotoxic potential of ozone by the induction of micronuclei as well as evaluating DNA strand breaks by the induction of micronuclei evaluated by means of the cytokinesis-block micronucleus (CBMN) assay as well as evaluating DNA strand breaks by Alkaline Comet Assay (CA) or Comet Assay. A549 cells viability decreases significantly at 24 hours treatment with 120 ppb of O3 while at 48 hours and 72 hours O3 treated cells viability doesn't differ in respect to the control. However a significative decrease of A549 viability is shown at 72 hours vs. 48 hours in both treated and not-treated cells. The viability trend in the Hs27 cells did not show any significant changes in treated samples compared to the control in all conditions. The two genotoxicity biomarkers, the micronucleus and the comet tests, showed in both the cell types exposed to ozone, a significant increase in the number of micronuclei and in the tail DNA % in respect to the control even if at different times/cell type. Moreover, we found that O3 provokes genotoxic effects more evident in A549 cancer cells than in normal fibroblasts Hs27 ones. We applied a cell growth simulation model referred to ozone treated or not cell lines to confirm that the ozone exposure causes a slackening in the cells replication.

Recombinant Human T-Cell Leukemia Virus Types 1 and 2 Tax Proteins Induce High Levels of CC-Chemokines and Downregulate CCR5 in Human Peripheral Blood Mononuclear Cells

PubMed Central

Barrios, Christy S.; Abuerreish, Muna; Lairmore, Michael D.; Castillo, Laura; Giam, Chou-Zen

2011-01-01

Abstract Human T-cell leukemia viruses types 1 (HTLV-1) and 2 (HTLV-2) produce key transcriptional regulatory gene products, known as Tax1 and Tax2, respectively. Tax1 and Tax2 transactivate multiple host genes involved in cellular immune responses within the cellular microenvironment, including induction of genes encoding expression of CC-chemokines. It is speculated that HTLV Tax proteins may act as immune modulators. In this study, recombinant Tax1 and Tax2 proteins were tested for their effects on the viability of cultured peripheral blood mononuclear cells (PBMCs), and their ability to induce expression of CC-chemokines and to downregulate the level of CCR5 expression in PBMCs. PBMCs obtained from uninfected donors were cultured in a range of Tax1 and Tax2 concentrations (10–100 pM), and supernatant fluids were harvested at multiple time points for quantitative determinations of MIP-1α/CCL3, MIP-1β/CCL4, and RANTES/CCL5. Treatment of PBMCs with Tax1 and Tax2 proteins (100 pM) resulted in a significant increase in viability over a 7-d period compared to controls (p<0.01). Both Tax1 and Tax2 induced high levels of all three CC-chemokines over the dosing range compared to mock-treated controls (p<0.05). The gated population of lymphocytes treated with Tax2, as well as lymphocytes from HTLV-2-infected donors, showed a significantly lower percentage of CCR5-positive cells compared to those of uninfected donors and from mock-treated lymphocytes, respectively (p<0.05). These results suggest that Tax1 and Tax2 could promote innate immunity in the extracellular environment during HTLV-1 and HTLV-2 infections via CC-chemokine ligands and receptors. PMID:22111594

Effects of size and surface of zinc oxide and aluminum-doped zinc oxide nanoparticles on cell viability inferred by proteomic analyses.

PubMed

Pan, Chih-Hong; Liu, Wen-Te; Bien, Mauo-Ying; Lin, I-Chan; Hsiao, Ta-Chih; Ma, Chih-Ming; Lai, Ching-Huang; Chen, Mei-Chieh; Chuang, Kai-Jen; Chuang, Hsiao-Chi

2014-01-01

Although the health effects of zinc oxide nanoparticles (ZnONPs) on the respiratory system have been reported, the fate, potential toxicity, and mechanisms in biological cells of these particles, as related to particle size and surface characteristics, have not been well elucidated. To determine the physicochemical properties of ZnONPs that govern cytotoxicity, we investigated the effects of size, electronic properties, zinc concentration, and pH on cell viability using human alveolar-basal epithelial A549 cells as a model. We observed that a 2-hour or longer exposure to ZnONPs induced changes in cell viability. The alteration in cell viability was associated with the zeta potentials and pH values of the ZnONPs. Proteomic profiling of A549 exposed to ZnONPs for 2 and 4 hours was used to determine the biological mechanisms of ZnONP toxicity. p53-pathway activation was the core mechanism regulating cell viability in response to particle size. Activation of the Wnt and TGFβ signaling pathways was also important in the cellular response to ZnONPs of different sizes. The cadherin and Wnt signaling pathways were important cellular mechanisms triggered by surface differences. These results suggested that the size and surface characteristics of ZnONPs might play an important role in their observed cytotoxicity. This approach facilitates the design of more comprehensive systems for the evaluation of nanoparticles.

Induction of apoptosis by pyrrolidinedithiocarbamate and N-acetylcysteine in vascular smooth muscle cells.

PubMed

Tsai, J C; Jain, M; Hsieh, C M; Lee, W S; Yoshizumi, M; Patterson, C; Perrella, M A; Cooke, C; Wang, H; Haber, E; Schlegel, R; Lee, M E

1996-02-16

Pyrrolidinedithiocarbamate (PDTC) and N-acetylcysteine (NAC) have been used as antioxidants to prevent apoptosis in lymphocytes, neurons, and vascular endothelial cells. We report here that PDTC and NAC induce apoptosis in rat and human smooth muscle cells. In rat aortic smooth muscle cells, PDTC induced cell shrinkage, chromatin condensation, and DNA strand breaks consistent with apoptosis. In addition, overexpression of Bcl-2 suppressed vascular smooth muscle cell death caused by PDTC and NAC. The viability of rat aortic smooth muscle cells decreased within 3 h of treatment with PDTC and was reduced to 30% at 12 h. The effect of PDTC and NAC on smooth muscle cells was not species specific because PDTC and NAC both caused dose-dependent reductions in viability in rat and human aortic smooth muscle cells. In contrast, neither PDTC nor NAC reduced viability in human aortic endothelial cells. The use of antioxidants to induce apoptosis in vascular smooth muscle cells may help prevent their proliferation in arteriosclerotic lesions.

A new method for long-term storage of titred microbial standard solutions suitable for microbiologic quality control activities of pharmaceutical companies.

PubMed

Chiellini, Carolina; Mocali, Stefano; Fani, Renato; Ferro, Iolanda; Bruschi, Serenella; Pinzani, Alessandro

2016-08-01

Commercially available lyophilized microbial standards are expensive and subject to reduction in cell viability due to freeze-drying stress. Here we introduce an inexpensive and straightforward method for in-house microbial standard preparation and cryoconservation that preserves constant cell titre and cell viability over 14 months.

Inhibition of NFkappaB reduces cellular viability in GH3 pituitary adenoma cells.

PubMed

Vender, John R; Laird, Melissa D; Dhandapani, Krishnan M

2008-05-01

Adenomas of the pituitary gland are among the most common types of tumors of the adult brain. Although adenomas are histologically benign, they may be associated with significant morbidity and mortality, mostly because of their invasive growth pattern and hormone hypersecretion. Current medical therapies are suppressive, acting at a receptor level. Thus, there is a need to identify novel cellular and molecular targets for pituitary tumors. We investigated the possible role of the NFkappaB transcription factor in pituitary tumor cell growth. The effect of NFkappaB pathway inhibition on cellular viability was studied in the GH3 pituitary adenoma cell line, a well-characterized rat cell line that secretes growth hormone and prolactin. Cells were treated with mechanistically diverse pharmacological NFkappaB pathway inhibitors or with molecular inhibitors that were overexpressed in tumor cells before the assessment of cellular viability. NFkappaB activity was also assessed in GH3 cells using deoxyribonucleic acid binding assays. GH3 cells exhibited constitutive NFkappaB activity, which contributed to increased cellular proliferation. Treatment with wedelolactone, an IkappaB kinase inhibitor, or overexpression of an IkappaB super-repressor reduced cell viability, further implicating NFkappaB in pituitary tumor cell growth. Pharmacological or molecular inhibition of Akt similarly reduced GH3 viability and NFkappaB binding, suggesting that constitutive activation of NFkappaB may be, at least in part, mediated by Akt. Directed targeting of the Akt and NFkappaB signaling pathways may be a useful adjunct in the clinical management of pituitary tumors. Further elucidation of this pathway may yield novel information regarding the behavior of pituitary tumors in humans.

The biocompatibility of modified experimental Portland cements with potential for use in dentistry.

PubMed

Camilleri, J

2008-12-01

To evaluate the biocompatibility of a group of new potential dental materials and their eluants by assessing cell viability. Calcium sulpho-aluminate cement (CSA), calcium fluoro-aluminate cement (CFA) and glass-ionomer cement (GIC; Ketac Molar), used as the control, were tested for biocompatibility. Using a direct test method cell viability was measured quantitatively using alamarBluetrade mark dye, and an indirect test method where cells were grown on material elutions and cell viability was assessed using methyltetrazolium (MTT) assay as recommended by ISO 10 993-Part 5 for in vitro testing. Statistical analysis was performed by analysis of variance and Tukey multi-comparison test method. Elution collected from the prototype cements and the GIC cured for 1 and 7 days allowed high cell activity after 24 h cell exposure, which reduced after 48 h when compared to the nontoxic glass-ionomer control, but increased significantly after 72 h cell contact. Elutions collected after 28 days revealed reduced cell activity at all cell exposure times. Cells placed in direct contact with the prototype materials showed reduced cell activity when compared with the control. Cell growth was poor when seeded in direct contact with the prototype cements. GIC encouraged cell growth after 1 day of contact. The eluted species for all the cements tested exhibited adequate cell viability in the early ages with reduced cell activity at 28 days. Changes in the production of calcium hydroxide as a by-product of cement hydration affect the material biocompatibility adversely.

Effects of demethoxycurcumin on the viability and apoptosis of skin cancer cells.

PubMed

Wu, Yaoqun; Zhang, Pei; Yang, Hongyun; Ge, Yong; Xin, Yong

2017-07-01

The present study investigated the effects and mechanisms of demethoxycurcumin (DMC) on a human skin squamous cell carcinoma cell line, A431, and a human keratinocyte cell line, HaCaT. A431 and HaCaT cells were cultured in vitro. The effects of DMC treatment on cell viability were analyzed using the Cell Counting kit‑8 (CCK‑8) assay; cell cycle distribution was analyzed by flow cytometry; apoptosis was assessed by flow cytometry and Hoechst 33258 staining; and the protein expression levels of cytochrome c, B‑cell lymphoma 2 (Bcl‑2), Bcl‑2‑associated X protein (BAX), caspase‑9 and caspase‑3 were evaluated by western blotting. CCK‑8 assay results demonstrated that DMC treatment significantly inhibited viability of A431 and HaCaT cells in a dose‑dependent manner. Flow cytometric analysis confirmed that DMC treatment induced apoptosis in a dose‑dependent manner, and significantly increased the proportion of cells in G2/M phase. Western blot analysis indicated that the protein expression levels of Bcl‑2 were decreased, whereas the expression levels of BAX, caspase‑9, caspase‑3 and cytochrome c were increased following DMC treatment compared with in untreated cells. In conclusion, DMC treatment significantly inhibited viability of A431 and HaCaT cells, and induced cell cycle arrest in G2/M phase. The present study indicated that DMC may induce apoptosis of skin cancer cells through a caspase‑dependent pathway.

Effects of extracellular calcium on viability and osteogenic differentiation of bone marrow stromal cells in vitro.

PubMed

Cheng, Shaowen; Wang, Wei; Lin, Zhongqin; Zhou, Ping; Zhang, Xiaolei; Zhang, Wei; Chen, Qingyu; Kou, Dongquan; Ying, Xiaozhou; Shen, Yue; Cheng, Xiaojie; Yu, Ziming; Peng, Lei; Lu, Chuanzhu

2013-09-01

Bone marrow stromal cells (BMSCs) have been extensively used for tissue engineering. However, the effect of Ca(2+) on the viability and osteogenic differentiation of BMSCs has yet to be evaluated. To determine the dose-dependent effect of Ca(2+) on viability and osteogenesis of BMSCs in vitro, BMSCs were cultured in calcium-free DMEM medium supplemented with various concentrations of Ca(2+) (0, 1, 2, 3, 4, and 5 mM) from calcium citrate. Cell viability was analyzed by MTT assay and osteogenic differentiation was evaluated by alkaline phosphatase (ALP) assay, Von Kossa staining, and real-time PCR. Ca(2+) stimulated BMSCs viability in a dose-dependent manner. At slightly higher concentrations (4 and 5 mM) in the culture, Ca(2+) significantly inhibited the activity of ALP on days 7 and 14 (P < 0.01 or P < 0.05), significantly suppressed collagen synthesis (P < 0.01 or P < 0.05), and significantly elevated calcium deposition (P < 0.01) and mRNA levels of osteocalcin (P < 0.01 or P < 0.05) and osteopontin (P < 0.01 or P < 0.05). Therefore, elevated concentrations of extracellular calcium may promote cell viability and late-stage osteogenic differentiation, but may suppress early-stage osteogenic differentiation in BMSCs.

Suppression of human immunodeficiency virus replication by ascorbate in chronically and acutely infected cells.

PubMed Central

Harakeh, S; Jariwalla, R J; Pauling, L

1990-01-01

We have studied the action of ascorbate (vitamin C) on human immunodeficiency virus type 1 (HIV-1), the etiological agent clinically associated with AIDS. We report the suppression of virus production and cell fusion in HIV-infected T-lymphocytic cell lines grown in the presence of nontoxic concentrations of ascorbate. In chronically infected cells expressing HIV at peak levels, ascorbate reduced the levels of extracellular reverse transcriptase (RT) activity (by greater than 99%) and of p24 antigen (by 90%) in the culture supernatant. Under similar conditions, no detectable inhibitory effects on cell viability, host metabolic activity, and protein synthesis were observed. In freshly infected CD4+ cells, ascorbate inhibited the formation of giant-cell syncytia (by approximately 93%). Exposure of cell-free virus to ascorbate at 37 degrees C for 1 day had no effect on its RT activity or syncytium-forming ability. Prolonged exposure of virus (37 degrees C for 4 days) in the presence of ascorbate (100-150 micrograms/ml) resulted in the drop by a factor of 3-14 in RT activity as compared to a reduction by a factor of 25-172 in extracellular RT released from chronically infected cells. These results indicate that ascorbate mediates an anti-HIV effect by diminishing viral protein production in infected cells and RT stability in extracellular virions. Images PMID:1698293

Comparative Evaluation of Cell Viability Immediately After Osteotomy for Implants With Drills and Piezosurgery: Immunohistochemistry Analysis.

PubMed

Pereira, Cassiano Costa Silva; Batista, Fábio Roberto de Souza; Jacob, Ricardo Garcia Mureb; Nogueira, Lamis Meorin; Carvalho, Abrahão Cavalcante Gomes de Souza; Gealh, Walter Cristiano; Garcia-Júnior, Idelmo Rangel; Okamoto, Roberta

2018-05-08

To evaluate the effect of reusing drills and piezosurgery tips during implant osteotomy on immediate bone cell viability through immunohistochemical analysis. Six male rabbits were divided into 2 groups and then divided into 5 subgroups-correspond to drills and tips used 10, 20, 30, 40, and 50 times, respectively. All animals received 10 osteotomies in each tibia, by use of the classic drilling procedure in one group (G1) and the piezosurgery device in the other group (G2). For immunohistochemical technique were utilized the osteoprotegerin, RANKL, osteocalcin, and caspase 3. Control procedures were performed by omitting the primary antibodies (negative control). Bone formation and resorption responses presented in more intense way during the piezosurgery. The expression of osteocalcin had become quite intense in piezosurgery groups, but with reduced immunostaining from the 30th osteotomy. The caspase 3 showed the viability of the osteoblast from the 20th osteotomy with piezosurgery and remained constant until the 50th. Piezosurgery provides greater osteoblastic cell viability than the system of conventional drilling. This study will provide data so that the authors can recycle the drills and tips for implant placement, thus enabling a better cell viability for osseointegration.

Trehalose effectiveness as a cryoprotectant in 2D and 3D cell cultures of human embryonic kidney cells.

PubMed

Hara, Jared; Tottori, Jordan; Anders, Megan; Dadhwal, Smritee; Asuri, Prashanth; Mobed-Miremadi, Maryam

2017-05-01

Post cryopreservation viability of human embryonic kidney (HEK) cells under two-dimensional (2D) and three-dimensional (3D) culture conditions was studied using trehalose as the sole cryoprotective agent. An L 9 (3 4 ) Taguchi design was used to optimize the cryoprotection cocktail seeding process prior to slow-freezing with the specific aim of maximizing cell viability measured 7 days post thaw, using the combinatorial cell viability and in-vitro cytotoxicity WST assay. At low (200 mM) and medium (800 mM) levels of trehalose concentration, encapsulation in alginate offered a greater protection to cryopreservation. However, at the highest trehalose concentration (1200 mM) and in the absence of the pre-incubation step, there was no statistical difference at the 95% CI (p = 0.0212) between the viability of the HEK cells under 2D and 3D culture conditions estimated to be 17.9 ± 4.6% and 14.0 ± 3.6%, respectively. A parallel comparison between cryoprotective agents conducted at the optimal levels of the L 9 study, using trehalose, dimethylsulfoxide and glycerol in alginate microcapsules yielded a viability of 36.0 ± 7.4% for trehalose, in average 75% higher than the results associated with the other two cell membrane-permeating compounds. In summary, the effectiveness of trehalose has been demonstrated by the fact that 3D cell cultures can readily be equilibrated with trehalose before cryopreservation, thus mitigating the cytotoxic effects of glycerol and dimethylsulfoxide.

Effects of long-term cryopreservation on peripheral blood progenitor cells.

PubMed

Vosganian, Gregory S; Waalen, Jill; Kim, Kevin; Jhatakia, Sejal; Schram, Ethan; Lee, Tracey; Riddell, Dan; Mason, James R

2012-11-01

The long-term stability of cryopreserved peripheral blood progenitor cells is an important issue for patients experiencing disease relapse. However, there is no consensus on how to evaluate the long-term effects of cryopreservation. We describe the effect of cryopreservation on viability and progenitor colony activity from 87 individual samples processed at the Scripps Green Hospital Stem Cell Processing Center (La Jolla, CA, USA). We randomly selected 87 peripheral blood hematopoietic stem cell (PBHSC) samples from 60 patients and evaluated the effect of cryopreservation on sample viability and red and white cell colony activity after < 24 h and 7, 10 and 15 years of cryopreservation. Viability was assayed via trypan blue dye exclusion and activity was measured following 14 days of culture. An age at collection older than 50 years may result in suboptimal activity and viability following long-term cryopreservation, while gender and disease status had no effect. Cryopreservation did not significantly affect white or red cell activity following 10 years of cryopreservation. However, for samples stored longer than 10 years, viability and activity significantly decreased. We noted a positive association between higher pre-cryopreservation %CD34 count and colony activity. Cryopreservation of peripheral blood progenitor cells for up to 10 years results in no loss of clonogenic capacity, as determined by culture activity, although longer durations of storage may affect activity. Until validated methods are developed, cryopreserved grafts should be evaluated based on pre-freeze CD34(+) cell counts as assayed by flow cytometry, and post-thaw sample evaluation should be reserved for patients identified as poor mobilizers.

Suitable Concentrations of Uric Acid Can Reduce Cell Death in Models of OGD and Cerebral Ischemia-Reperfusion Injury.

PubMed

Zhang, Bin; Yang, Ning; Lin, Shao-Peng; Zhang, Feng

2017-07-01

Cerebral infarction (CI) is a common clinical cerebrovascular disease, and to explore the pathophysiological mechanisms and seek effective treatment means are the hotspot and difficult point in medical research nowadays. Numerous studies have confirmed that uric acid plays an important role in CI, but the mechanism has not yet been clarified. When treating HT22 and BV-2 cells with different concentrations of uric acid, uric acid below 450 μM does not have significant effect on cell viability, but uric acid more than 500 μM can significantly inhibit cell viability. After establishing models of OGD (oxygen-glucose deprivation) with HT22 and BV-2 cells, uric acid at a low concentration (50 μM) cannot improve cell viability and apoptosis, and Reactive oxygen species (ROS) levels during OGD/reoxygenation; a suitable concentration (300 μM) of uric acid can significantly improve cell viability and apoptosis, and reduce ROS production during OGD/reoxygenation; but a high concentration (1000 μM) of uric acid can further reduce cell viability and enhance ROS production. After establishing middle cerebral artery occlusion of male rats with suture method, damage and increase of ROS production in brain tissue could be seen, and after adding suitable concentration of uric acid, the degree of brain damage and ROS production was reduced. Therefore, different concentrations of uric acid should have different effect, and suitable concentrations of uric acid have neuroprotective effect, and this finding may provide guidance for study on the clinical curative effect of uric acid.

In vitro effects of preserved and unpreserved anti-allergic drugs on human corneal epithelial cells.

PubMed

Guzman-Aranguez, Ana; Calvo, Patricia; Ropero, Inés; Pintor, Jesús

2014-11-01

Treatment with topical eye drops for long-standing ocular diseases like allergy can induce detrimental side effects. The purpose of this study was to investigate in vitro cytotoxicity of commercially preserved and unpreserved anti-allergic eye drops on the viability and barrier function of monolayer and stratified human corneal-limbal epithelial cells. Cells were treated with unpreserved ketotifen solution, benzalkonium chloride (BAC)-containing anti-allergic drugs (ketotifen, olopatadine, levocabastine) as well as BAC alone. 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay was used to determine cell viability. Effects of compounds on barrier function were analyzed measuring transepithelial electrical resistance (TEER) to determine paracellular permeability and rose bengal assays to evaluate transcellular barrier formation. The BAC-preserved anti-allergic formulations and BAC alone significantly reduced cell viability, monolayer cultures being more sensitive to damage by these solutions. Unpreserved ketotifen induced the least diminution in cell viability. The extent of decrease of cell viability was clearly dependent of BAC presence, but it was also affected by the different types of drugs when the concentration of BAC was low and the short time of exposure. Treatment with BAC-containing anti-allergic drugs and BAC alone resulted in increased paracellular permeability and loss of transcellular barrier function as indicated by TEER measurement and rose bengal assays. The presence of the preservative BAC in anti-allergic eye drop formulations contributes importantly to the cytotoxic effects induced by these compounds. Stratified cell cultures seem to be a more relevant model for toxicity evaluation induced on the ocular surface epithelia than monolayer cultures.

Effects of Incorporating Carboxymethyl Chitosan into PMMA Bone Cement Containing Methotrexate

PubMed Central

Liu, Bo-Ming; Li, Ming; Yin, Bao-Sheng; Zou, Ji-Yang; Zhang, Wei-Guo; Wang, Shou-Yu

2015-01-01

Treatment of bone metastases usually includes surgical resection with local filling of methotrexate (MTX) in polymethyl methacrylate (PMMA) cement. We investigated whether incorporating carboxymethyl chitosan (CMCS) in MTX-PMMA cement might overcome disadvantages associated with MTX. To determine the optimal CMCS+MTX concentration to suppress the viability of cancer cells, an integrated microfluidic chip culturing highly metastatic lung cancer cells (H460) was employed. The mechanical properties, microstructure, and MTX release of (CMCS+MTX)-PMMA cement were evaluated respectively by universal mechanical testing machine, scanning electron microscopy (SEM), and incubation in simulated body fluid with subsequent HPLC-MS. Implants of MTX-PMMA and (CMCS+MTX)-PMMA cement were evaluated in vivo in guinea pig femurs over time using spiral computed tomography with three-dimensional image reconstruction, and SEM at 6 months. Viability of H460 cells was significantly lowest after treatment with 57 μg/mL CMCS + 21 μg/mL MTX, which was thus used in subsequent experiments. Incorporation of 1.6% (w/w) CMCS to MTX-PMMA significantly increased the bending modulus, bending strength, and compressive strength by 5, 2.8, and 5.2%, respectively, confirmed by improved microstructural homogeneity. Incorporation of CMCS delayed the time-to-plateau of MTX release by 2 days, but increased the fraction released at the plateau from 3.24% (MTX-PMMA) to 5.34%. Relative to the controls, the (CMCS+MTX)-PMMA implants integrated better with the host bone. SEM revealed pores in the cement of the (CMCS+MTX)-PMMA implants that were not obvious in the controls. In conclusion, incorporation of CMCS in MTX-PMMA appears a feasible and effective modification for improving the anti-tumor properties of MTX-PMMA cement. PMID:26657526

In vitro antimicrobial activity of natural toxins and animal venoms tested against Burkholderia pseudomallei

PubMed Central

Perumal Samy, R; Pachiappan, A; Gopalakrishnakone, P; Thwin, Maung M; Hian, Yap E; Chow, Vincent TK; Bow, Ho; Weng, Joseph T

2006-01-01

Background Burkholderia pseudomallei are the causative agent of melioidosis. Increasing resistance of the disease to antibiotics is a severe problem in treatment regime and has led to intensification of the search for new drugs. Antimicrobial peptides are the most ubiquitous in nature as part of the innate immune system and host defense mechanism. Methods Here, we investigated a group of venoms (snakes, scorpions and honey bee venoms) for antimicrobial properties against two strains of Gram-negative bacteria Burkholderia pseudomallei by using disc-diffusion assay for in vitro susceptibility testing. The antibacterial activities of the venoms were compared with that of the isolated L-amino acid oxidase (LAAO) and phospholipase A2 (PLA2s) enzymes. MICs were determined using broth dilution method. Bacterial growth was assessed by measurement of optical density at the lowest dilutions (MIC 0.25 mg/ml). The cell viability was measured using tetrazolium salts (XTT) based cytotoxic assay. Results The studied venoms showed high antimicrobial activity. The venoms of C. adamanteus, Daboia russelli russelli, A. halys, P. australis, B. candidus and P. guttata were equally as effective as Chloramphenicol and Ceftazidime (30 μg/disc). Among those tested, phospholipase A2 enzymes (crotoxin B and daboiatoxin) showed the most potent antibacterial activity against Gram-negative (TES) bacteria. Naturally occurring venom peptides and phospholipase A2 proved to possess highly potent antimicrobial activity against Burkholderia pseudomallei. The XTT-assay results showed that the cell survival decreased with increasing concentrations (0.05–10 mg/mL) of Crotalus adamanteus venom, with no effect on the cell viability evident at 0.5 mg/mL. Conclusion This antibacterial profile of snake venoms reported herein will be useful in the search for potential antibacterial agents against drug resistant microorganisms like B. pseudomallei. PMID:16784542

Effects of Incorporating Carboxymethyl Chitosan into PMMA Bone Cement Containing Methotrexate.

PubMed

Liu, Bo-Ming; Li, Ming; Yin, Bao-Sheng; Zou, Ji-Yang; Zhang, Wei-Guo; Wang, Shou-Yu

2015-01-01

Treatment of bone metastases usually includes surgical resection with local filling of methotrexate (MTX) in polymethyl methacrylate (PMMA) cement. We investigated whether incorporating carboxymethyl chitosan (CMCS) in MTX-PMMA cement might overcome disadvantages associated with MTX. To determine the optimal CMCS+MTX concentration to suppress the viability of cancer cells, an integrated microfluidic chip culturing highly metastatic lung cancer cells (H460) was employed. The mechanical properties, microstructure, and MTX release of (CMCS+MTX)-PMMA cement were evaluated respectively by universal mechanical testing machine, scanning electron microscopy (SEM), and incubation in simulated body fluid with subsequent HPLC-MS. Implants of MTX-PMMA and (CMCS+MTX)-PMMA cement were evaluated in vivo in guinea pig femurs over time using spiral computed tomography with three-dimensional image reconstruction, and SEM at 6 months. Viability of H460 cells was significantly lowest after treatment with 57 μg/mL CMCS + 21 μg/mL MTX, which was thus used in subsequent experiments. Incorporation of 1.6% (w/w) CMCS to MTX-PMMA significantly increased the bending modulus, bending strength, and compressive strength by 5, 2.8, and 5.2%, respectively, confirmed by improved microstructural homogeneity. Incorporation of CMCS delayed the time-to-plateau of MTX release by 2 days, but increased the fraction released at the plateau from 3.24% (MTX-PMMA) to 5.34%. Relative to the controls, the (CMCS+MTX)-PMMA implants integrated better with the host bone. SEM revealed pores in the cement of the (CMCS+MTX)-PMMA implants that were not obvious in the controls. In conclusion, incorporation of CMCS in MTX-PMMA appears a feasible and effective modification for improving the anti-tumor properties of MTX-PMMA cement.

STING-Dependent 2'-5' Oligoadenylate Synthetase-Like Production Is Required for Intracellular Mycobacterium leprae Survival.

PubMed

de Toledo-Pinto, Thiago Gomes; Ferreira, Anna Beatriz Robottom; Ribeiro-Alves, Marcelo; Rodrigues, Luciana Silva; Batista-Silva, Leonardo Ribeiro; Silva, Bruno Jorge de Andrade; Lemes, Robertha Mariana Rodrigues; Martinez, Alejandra Nóbrega; Sandoval, Felipe Galvan; Alvarado-Arnez, Lucia Elena; Rosa, Patrícia Sammarco; Shannon, Edward Joseph; Pessolani, Maria Cristina Vidal; Pinheiro, Roberta Olmo; Antunes, Sérgio Luís Gomes; Sarno, Euzenir Nunes; Lara, Flávio Alves; Williams, Diana Lynn; Ozório Moraes, Milton

2016-07-15

Cytosolic detection of nucleic acids elicits a type I interferon (IFN) response and plays a critical role in host defense against intracellular pathogens. Herein, a global gene expression profile of Mycobacterium leprae-infected primary human Schwann cells identified the genes differentially expressed in the type I IFN pathway. Among them, the gene encoding 2'-5' oligoadenylate synthetase-like (OASL) underwent the greatest upregulation and was also shown to be upregulated in M. leprae-infected human macrophage cell lineages, primary monocytes, and skin lesion specimens from patients with a disseminated form of leprosy. OASL knock down was associated with decreased viability of M. leprae that was concomitant with upregulation of either antimicrobial peptide expression or autophagy levels. Downregulation of MCP-1/CCL2 release was also observed during OASL knock down. M. leprae-mediated OASL expression was dependent on cytosolic DNA sensing mediated by stimulator of IFN genes signaling. The addition of M. leprae DNA enhanced nonpathogenic Mycobacterium bovis bacillus Calmette-Guerin intracellular survival, downregulated antimicrobial peptide expression, and increased MCP-1/CCL2 secretion. Thus, our data uncover a promycobacterial role for OASL during M. leprae infection that directs the host immune response toward a niche that permits survival of the pathogen. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

Quantum measurement and orientation tracking of fluorescent nanodiamonds inside living cells

NASA Astrophysics Data System (ADS)

McGuinness, L. P.; Yan, Y.; Stacey, A.; Simpson, D. A.; Hall, L. T.; MacLaurin, D.; Prawer, S.; Mulvaney, P.; Wrachtrup, J.; Caruso, F.; Scholten, R. E.; Hollenberg, L. C. L.

2011-06-01

Fluorescent particles are routinely used to probe biological processes. The quantum properties of single spins within fluorescent particles have been explored in the field of nanoscale magnetometry, but not yet in biological environments. Here, we demonstrate optically detected magnetic resonance of individual fluorescent nanodiamond nitrogen-vacancy centres inside living human HeLa cells, and measure their location, orientation, spin levels and spin coherence times with nanoscale precision. Quantum coherence was measured through Rabi and spin-echo sequences over long (>10 h) periods, and orientation was tracked with effective 1° angular precision over acquisition times of 89 ms. The quantum spin levels served as fingerprints, allowing individual centres with identical fluorescence to be identified and tracked simultaneously. Furthermore, monitoring decoherence rates in response to changes in the local environment may provide new information about intracellular processes. The experiments reported here demonstrate the viability of controlled single spin probes for nanomagnetometry in biological systems, opening up a host of new possibilities for quantum-based imaging in the life sciences.

Autumn Royal and Ribier Grape Juice Extracts Reduced Viability and Metastatic Potential of Colon Cancer Cells.

PubMed

Valenzuela, Manuel; Bastias, Lorena; Montenegro, Iván; Werner, Enrique; Madrid, Alejandro; Godoy, Patricio; Párraga, Mario; Villena, Joan

2018-01-01

Antioxidants are known to be beneficial to health. This paper evaluates the potential chemopreventive and anticancer properties of phenolic compounds present in grape juice extracts (GJE) from Autumn Royal and Ribier varieties. The effects of these GJE on viability (SRB day assay) and metastatic potential (migration and invasion parameters) of colon cancer cell lines HT-29 and SW-480 were evaluated. The effects of GJE on two matrix metalloproteinase gene expressions (MMP2 and MMP9) were also evaluated via qRT-PCR. In the former, GJE reduced cell viability in both cell lines in a dose-dependent manner. GJE treatment also reduced cell migration and invasion. Moreover, MMP-2 and MMP-9 gene expression diminished depending on extract and on cell type. Conclusions . These results provide novel information concerning anticancer properties of selected GJE by revealing selective cytotoxicity and the ability to reduce invasiveness of colon cancer cells.

Autumn Royal and Ribier Grape Juice Extracts Reduced Viability and Metastatic Potential of Colon Cancer Cells

PubMed Central

Valenzuela, Manuel; Bastias, Lorena; Montenegro, Iván; Werner, Enrique; Madrid, Alejandro; Godoy, Patricio

2018-01-01

Antioxidants are known to be beneficial to health. This paper evaluates the potential chemopreventive and anticancer properties of phenolic compounds present in grape juice extracts (GJE) from Autumn Royal and Ribier varieties. The effects of these GJE on viability (SRB day assay) and metastatic potential (migration and invasion parameters) of colon cancer cell lines HT-29 and SW-480 were evaluated. The effects of GJE on two matrix metalloproteinase gene expressions (MMP2 and MMP9) were also evaluated via qRT-PCR. In the former, GJE reduced cell viability in both cell lines in a dose-dependent manner. GJE treatment also reduced cell migration and invasion. Moreover, MMP-2 and MMP-9 gene expression diminished depending on extract and on cell type. Conclusions. These results provide novel information concerning anticancer properties of selected GJE by revealing selective cytotoxicity and the ability to reduce invasiveness of colon cancer cells. PMID:29552079

Yeast viability and concentration analysis using lens-free computational microscopy and machine learning

NASA Astrophysics Data System (ADS)

Feizi, Alborz; Zhang, Yibo; Greenbaum, Alon; Guziak, Alex; Luong, Michelle; Chan, Raymond Yan Lok; Berg, Brandon; Ozkan, Haydar; Luo, Wei; Wu, Michael; Wu, Yichen; Ozcan, Aydogan

2017-03-01

Research laboratories and the industry rely on yeast viability and concentration measurements to adjust fermentation parameters such as pH, temperature, and pressure. Beer-brewing processes as well as biofuel production can especially utilize a cost-effective and portable way of obtaining data on cell viability and concentration. However, current methods of analysis are relatively costly and tedious. Here, we demonstrate a rapid, portable, and cost-effective platform for imaging and measuring viability and concentration of yeast cells. Our platform features a lens-free microscope that weighs 70 g and has dimensions of 12 × 4 × 4 cm. A partially-coherent illumination source (a light-emitting-diode), a band-pass optical filter, and a multimode optical fiber are used to illuminate the sample. The yeast sample is directly placed on a complementary metal-oxide semiconductor (CMOS) image sensor chip, which captures an in-line hologram of the sample over a large field-of-view of >20 mm2. The hologram is transferred to a touch-screen interface, where a trained Support Vector Machine model classifies yeast cells stained with methylene blue as live or dead and measures cell viability as well as concentration. We tested the accuracy of our platform against manual counting of live and dead cells using fluorescent exclusion staining and a bench-top fluorescence microscope. Our regression analysis showed no significant difference between the two methods within a concentration range of 1.4 × 105 to 1.4 × 106 cells/mL. This compact and cost-effective yeast analysis platform will enable automatic quantification of yeast viability and concentration in field settings and resource-limited environments.

On-chip gradient generation in 256 microfluidic cell cultures: simulation and experimental validation.

PubMed

Somaweera, Himali; Haputhanthri, Shehan O; Ibraguimov, Akif; Pappas, Dimitri

2015-08-07

A microfluidic diffusion diluter was used to create a stable concentration gradient for dose response studies. The microfluidic diffusion diluter used in this study consisted of 128 culture chambers on each side of the main fluidic channel. A calibration method was used to find unknown concentrations with 12% error. Flow rate dependent studies showed that changing the flow rates generated different gradient patterns. Mathematical simulations using COMSOL Multi-physics were performed to validate the experimental data. The experimental data obtained for the flow rate studies agreed with the simulation results. Cells could be loaded into culture chambers using vacuum actuation and cultured for long times under low shear stress. Decreasing the size of the culture chambers resulted in faster gradient formation (20 min). Mass transport into the side channels of the microfluidic diffusion diluter used in this study is an important factor in creating the gradient using diffusional mixing as a function of the distance. To demonstrate the device's utility, an H2O2 gradient was generated while culturing Ramos cells. Cell viability was assayed in the 256 culture chambers, each at a discrete H2O2 concentration. As expected, the cell viability for the high concentration side channels increased (by injecting H2O2) whereas the cell viability in the low concentration side channels decreased along the chip due to diffusional mixing as a function of distance. COMSOL simulations were used to identify the effective concentration of H2O2 for cell viability in each side chamber at 45 min. The gradient effects were confirmed using traditional H2O2 culture experiments. Viability of cells in the microfluidic device under gradient conditions showed a linear relationship with the viability of the traditional culture experiment. Development of the microfluidic device used in this study could be used to study hundreds of concentrations of a compound in a single experiment.

Active targeting of cancer cells using folic acid-conjugated platinum nanoparticles.

PubMed

Teow, Yiwei; Valiyaveettil, Suresh

2010-12-01

Interaction of nanoparticles with human cells is an interesting topic for understanding toxicity and developing potential drug candidates. Water soluble platinum nanoparticles were synthesized via reduction of hexachloroplatinic acid using sodium borohydride in the presence of capping agents. The bioactivity of folic acid and poly(vinyl pyrrolidone) capped platinum nanoparticles (Pt-nps) has been investigated using commercially available cell lines. In the cell viability experiments, PVP-capped nanoparticles were found to be less toxic (>80% viability), whereas, folic acid-capped platinum nanoparticles showed a reduced viability down to 24% after 72 h of exposure at a concentration of 100 μg ml(-1) for MCF7 breast cancer cells. Such toxicity, combined with the possibility to incorporate functional organic molecules as capping agents, can be used for developing new drug candidates.

Polyphenolic extracts of edible flowers incorporated onto atelocollagen matrices and their effect on cell viability.

PubMed

López-García, Jorge; Kuceková, Zdenka; Humpolíček, Petr; Mlček, Jiři; Sáha, Petr

2013-10-30

The phenolic extract of chives flowers (Allium schoenoprasum, Liliaceae), introduced Sage (Salvia pratensis, Lamiaceae), European elderberry (Sambucus nigra, Caprifoliaceae) and common dandelion (Taraxacum officinale, Asteraceae) were characterised by High Performance Liquid Chromatography and incorporated in different concentrations onto atelocollagen thin films. In order to assess the biological impact of these phenolic compounds on cell viability, human immortalised non-tumorigenic keratinocyte cell line was seeded on the thin films and cell proliferation was determined by using an MTT assay. In addition, their antimicrobial activity was estimated by using an agar diffusion test. Data indicated the concomitance between cell viability and concentration of polyphenols. These findings suggest that these phenolic-endowed atelocollagen films might be suitable for tissue engineering applications, on account of the combined activity of polyphenols and collagen.

Increased efficiency of mammalian somatic cell hybrid production under microgravity conditions during ballistic rocket flight

NASA Technical Reports Server (NTRS)

Schnettler, R.; Gessner, P.; Zimmermann, U.; Neil, G. A.; Urnovitz, H. B.

1989-01-01

The electrofusion of hybridoma cell lines under short-duration microgravity during a flight of the TEXUS 18 Black Brand ballistic sounding rocket at Kiruna, Sweden is reported. The fusion partners, growth medium, cell fusion medium, cell fusion, cell viability in the fusion medium, and postfusion cell culture are described, and the rocket, cell fusion chamber, apparatus, and module are examined. The experimental timeline, the effects of fusion medium and incubation time on cell viability and hybrid yields, and the effect of microgravity on hybrid yields are considered.

Evolution subverting essentiality: Dispensability of the cell attachment Arg-Gly-Asp motif in multiply passaged foot-and-mouth disease virus

PubMed Central

Martínez, Miguel A.; Verdaguer, Nuria; Mateu, Mauricio G.; Domingo, Esteban

1997-01-01

Aphthoviruses use a conserved Arg-Gly-Asp triplet for attachment to host cells and this motif is believed to be essential for virus viability. Here we report that this triplet—which is also a widespread motif involved in cell-to-cell adhesion—can become dispensable upon short-term evolution of the virus harboring it. Foot-and-mouth disease virus (FMDV), which was multiply passaged in cell culture, showed an altered repertoire of antigenic variants resistant to a neutralizing monoclonal antibody. The altered repertoire includes variants with substitutions at the Arg-Gly-Asp motif. Mutants lacking this sequence replicated normally in cell culture and were indistinguishable from the parental virus. Studies with individual FMDV clones indicate that amino acid replacements on the capsid surface located around the loop harboring the Arg-Gly-Asp triplet may mediate in the dispensability of this motif. The results show that FMDV quasispecies evolving in a constant biological environment have the capability of rendering totally dispensable a receptor recognition motif previously invariant, and to ensure an alternative pathway for normal viral replication. Thus, variability of highly conserved motifs, even those that viruses have adapted from functional cellular motifs, can contribute to phenotypic flexibility of RNA viruses in nature. PMID:9192645

Air Pollution Particulate Matter Alters Antimycobacterial Respiratory Epithelium Innate Immunity

PubMed Central

Rivas-Santiago, César E.; Sarkar, Srijata; Cantarella, Pasquale; Osornio-Vargas, Álvaro; Quintana-Belmares, Raúl; Meng, Qingyu; Kirn, Thomas J.; Ohman Strickland, Pamela; Chow, Judith C.; Watson, John G.; Torres, Martha

2015-01-01

Inhalation exposure to indoor air pollutants and cigarette smoke increases the risk of developing tuberculosis (TB). Whether exposure to ambient air pollution particulate matter (PM) alters protective human host immune responses against Mycobacterium tuberculosis has been little studied. Here, we examined the effect of PM from Iztapalapa, a municipality of Mexico City, with aerodynamic diameters below 2.5 μm (PM2.5) and 10 μm (PM10) on innate antimycobacterial immune responses in human alveolar type II epithelial cells of the A549 cell line. Exposure to PM2.5 or PM10 deregulated the ability of the A549 cells to express the antimicrobial peptides human β-defensin 2 (HBD-2) and HBD-3 upon infection with M. tuberculosis and increased intracellular M. tuberculosis growth (as measured by CFU count). The observed modulation of antibacterial responsiveness by PM exposure was associated with the induction of senescence in PM-exposed A549 cells and was unrelated to PM-mediated loss of cell viability. Thus, the induction of senescence and downregulation of HBD-2 and HBD-3 expression in respiratory PM-exposed epithelial cells leading to enhanced M. tuberculosis growth represent mechanisms by which exposure to air pollution PM may increase the risk of M. tuberculosis infection and the development of TB. PMID:25847963

LncRNA-LET inhibits cell viability, migration and EMT while induces apoptosis by up-regulation of TIMP2 in human granulosa-like tumor cell line KGN.

PubMed

Han, Qingfang; Zhang, Wenke; Meng, Jinlai; Ma, Li; Li, Aihua

2018-04-01

Polycystic ovary syndrome (PCOS) is a common endocrine disease characterized by hyperandrogenism, irregular menses, and polycystic ovaries. Several long non-coding RNAs (lncRNAs) are aberrantly expressed in PCOS patients; however, little is known about the effects of the lncRNA-low expression in tumor (lncRNA-LET) on PCOS. We aimed to explore the effects of lncRNA-LET on human granulosa-like tumor cell line, KGN. Expression of lncRNA-LET in normal IOSE80 cells and granulosa cells was determined by qRT-PCR. KGN cell viability, apoptosis and migration were measured by trypan blue exclusion method, flow cytometry assay and wound healing assay, respectively. TGF-β1 was used to induce epithelial-mesenchymal transition (EMT) process. LncRNA-LET expression and mRNA expressions of TIMP2 and EMT-related proteins were measured by qRT-PCR. Western blot analysis was used to measure the protein expression of apoptosis-related proteins, EMT-related proteins, TIMP2, and the proteins in the Wnt/β-catenin and Notch signaling pathways. lncRNA-LET was down-regulated in KGN cells, and its overexpression inhibited cell viability and migration, and promoted apoptosis in KGN cells. Overexpression of lncRNA-LET increased the expression of E-cadherin and decreased the expressions of N-cadherin and vimentin in KGN cells. These effects of lncRNA-LET on KGN cells were reversed by TIMP2 suppression. Overexpression of TIMP2 inhibited cell viability, migration and EMT process, and increased apoptosis by activating the Wnt/β-catenin and Notch pathways. Overexpression of lncRNA-LET inhibits cell viability, migration and EMT process, and increases apoptosis in KGN cells by up-regulating the expression of TIMP2 and activating the Wnt/β-catenin and notch signaling pathways. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Improvement of Storage Medium for Cultured Human Retinal Pigment Epithelial Cells Using Factorial Design.

PubMed

Pasovic, L; Utheim, T P; Reppe, S; Khan, A Z; Jackson, C J; Thiede, B; Berg, J P; Messelt, E B; Eidet, J R

2018-04-09

Storage of human retinal pigment epithelium (hRPE) can contribute to the advancement of cell-based RPE replacement therapies. The present study aimed to improve the quality of stored hRPE cultures by identifying storage medium additives that, alone or in combination, contribute to enhancing cell viability while preserving morphology and phenotype. hRPE cells were cultured in the presence of the silk protein sericin until pigmentation. Cells were then stored for 10 days in storage medium plus sericin and either one of 46 different additives. Individual effects of each additive on cell viability were assessed using epifluorescence microscopy. Factorial design identified promising additive combinations by extrapolating their individual effects. Supplementing the storage medium with sericin combined with adenosine, L-ascorbic acid and allopurinol resulted in the highest cell viability (98.6 ± 0.5%) after storage for three days, as measured by epifluorescence microscopy. Flow cytometry validated the findings. Proteomics identified 61 upregulated and 65 downregulated proteins in this storage group compared to the unstored control. Transmission electron microscopy demonstrated the presence of melanosomes after storage in the optimized medium. We conclude that the combination of adenosine, L-ascorbic acid, allopurinol and sericin in minimal essential medium preserves RPE pigmentation while maintaining cell viability during storage.

Cooperation of HIF- and NCAM-mediated mechanisms in cell viability of hippocampal cultures after oxygen-glucose deprivation.

PubMed

Lushnikova, Iryna; Nikandrova, Yelyzaveta; Skibo, Galyna

2017-10-01

Neurodegenerative diseases of different genesis are the result of cellular damages including those caused by oxygen and glucose deficit. Neuronal survival or death in brain pathologies depends on a variety of interrelated molecular mechanisms. A key role in modulation of neuron viability belongs to HIF (hypoxia-inducible factor) and NCAM (neural cell adhesion molecules) signaling pathways. In this work, we used organotypic and dissociated hippocampal cultures to analyze cell viability and HIF-1α immunopositive (HIF-1α + ) signal after 30 min oxygen-glucose deprivation (OGD) followed by 24 h of reoxygenation in the presence of FGL (synthetic NCAM-derived mimetic peptide). According to LDH- and MTS-assay of cell viability, FGL showed a neuroprotective effect, which was attributed to the association with FGFR. We showed that these effects correlated with changes of the HIF-1α + level suggesting the communications of HIF and NCAM signaling pathways. These data extend our knowledge of neurodegeneration mechanisms and open additional potential for the development of neuroprotection strategies. © 2017 International Federation for Cell Biology.

The bacterial parasite Pasteuria ramosa is not killed if it fails to infect: implications for coevolution.

PubMed

King, Kayla C; Auld, Stuart K J R; Wilson, Philip J; James, Janna; Little, Tom J

2013-02-01

Strong selection on parasites, as well as on hosts, is crucial for fueling coevolutionary dynamics. Selection will be especially strong if parasites that encounter resistant hosts are destroyed and diluted from the local environment. We tested whether spores of the bacterial parasite Pasteuria ramosa were passed through the gut (the route of infection) of their host, Daphnia magna, and whether passaged spores remained viable for a "second chance" at infecting a new host. In particular, we tested if this viability (estimated via infectivity) depended on host genotype, whether or not the genotype was susceptible, and on initial parasite dose. Our results show that Pasteuria spores generally remain viable after passage through both susceptible and resistant Daphnia. Furthermore, these spores remained infectious even after being frozen for several weeks. If parasites can get a second chance at infecting hosts in the wild, selection for infection success in the first instance will be reduced. This could also weaken reciprocal selection on hosts and slow the coevolutionary process.

Comparative Genomics of Field Isolates of Mycobacterium bovis and M. caprae Provides Evidence for Possible Correlates with Bacterial Viability and Virulence.

PubMed

de la Fuente, José; Díez-Delgado, Iratxe; Contreras, Marinela; Vicente, Joaquín; Cabezas-Cruz, Alejandro; Tobes, Raquel; Manrique, Marina; López, Vladimir; Romero, Beatriz; Bezos, Javier; Dominguez, Lucas; Sevilla, Iker A; Garrido, Joseba M; Juste, Ramón; Madico, Guillermo; Jones-López, Edward; Gortazar, Christian

2015-11-01

Mycobacteria of the Mycobacterium tuberculosis complex (MTBC) greatly affect humans and animals worldwide. The life cycle of mycobacteria is complex and the mechanisms resulting in pathogen infection and survival in host cells are not fully understood. Recently, comparative genomics analyses have provided new insights into the evolution and adaptation of the MTBC to survive inside the host. However, most of this information has been obtained using M. tuberculosis but not other members of the MTBC such as M. bovis and M. caprae. In this study, the genome of three M. bovis (MB1, MB3, MB4) and one M. caprae (MB2) field isolates with different lesion score, prevalence and host distribution phenotypes were sequenced. Genome sequence information was used for whole-genome and protein-targeted comparative genomics analysis with the aim of finding correlates with phenotypic variation with potential implications for tuberculosis (TB) disease risk assessment and control. At the whole-genome level the results of the first comparative genomics study of field isolates of M. bovis including M. caprae showed that as previously reported for M. tuberculosis, sequential chromosomal nucleotide substitutions were the main driver of the M. bovis genome evolution. The phylogenetic analysis provided a strong support for the M. bovis/M. caprae clade, but supported M. caprae as a separate species. The comparison of the MB1 and MB4 isolates revealed differences in genome sequence, including gene families that are important for bacterial infection and transmission, thus highlighting differences with functional implications between isolates otherwise classified with the same spoligotype. Strategic protein-targeted analysis using the ESX or type VII secretion system, proteins linking stress response with lipid metabolism, host T cell epitopes of mycobacteria, antigens and peptidoglycan assembly protein identified new genetic markers and candidate vaccine antigens that warrant further study to develop tools to evaluate risks for TB disease caused by M. bovis/M.caprae and for TB control in humans and animals.

Canine adipose-derived stromal cell viability following exposure to synovial fluid from osteoarthritic joints.

PubMed

Kiefer, Kristina M; O'Brien, Timothy D; Pluhar, Elizabeth G; Conzemius, Michael

2015-01-01

Stem cell therapy used in clinical application of osteoarthritis in veterinary medicine typically involves intra-articular injection of the cells, however the effect of an osteoarthritic environment on the fate of the cells has not been investigated. Assess the viability of adipose derived stromal cells following exposure to osteoarthritic joint fluid. Adipose derived stromal cells (ASCs) were derived from falciform adipose tissue of five adult dogs, and osteoarthritic synovial fluid (SF) was obtained from ten patients undergoing surgical intervention on orthopedic diseases with secondary osteoarthritis. Normal synovial fluid was obtained from seven adult dogs from an unrelated study. ASCs were exposed to the following treatment conditions: culture medium, normal SF, osteoarthritic SF, or serial dilutions of 1:1 to 1:10 of osteoarthritic SF with media. Cells were then harvested and assessed for viability using trypan blue dye exclusion. There was no significant difference in the viability of cells in culture medium or normal SF. Significant differences were found between cells exposed to any concentration of osteoarthritic SF and normal SF and between cells exposed to undiluted osteoarthritic SF and all serial dilutions. Subsequent dilutions reduced cytotoxicity. Osteoarthritic synovial fluid in this ex vivo experiment is cytotoxic to ASCs, when compared with normal synovial fluid. Current practice of direct injection of ASCs into osteoarthritic joints should be re-evaluated to determine if alternative means of administration may be more effective.

Therapeutic potential of the metabolic modulator phenformin in targeting the stem cell compartment in melanoma.

PubMed

Petrachi, Tiziana; Romagnani, Alessandra; Albini, Adriana; Longo, Caterina; Argenziano, Giuseppe; Grisendi, Giulia; Dominici, Massimo; Ciarrocchi, Alessia; Dallaglio, Katiuscia

2017-01-24

Melanoma is the most dangerous and treatment-resistant skin cancer. Tumor resistance and recurrence are due to the persistence in the patient of aggressive cells with stem cell features, the cancer stem cells (CSC). Recent evidences have shown that CSC display a distinct metabolic profile as compared to tumor bulk population: a promising anti-tumor strategy is therefore to target specific metabolic pathways driving CSC behavior. Biguanides (metformin and phenformin) are anti-diabetic drugs able to perturb cellular metabolism and displaying anti-cancer activity. However, their ability to target the CSC compartment in melanoma is not known. Here we show that phenformin, but not metformin, strongly reduces melanoma cell viability, growth and invasion in both 2D and 3D (spheroids) models. While phenformin decreases melanoma CSC markers expression and the levels of the pro-survival factor MITF, MITF overexpression fails to prevent phenformin effects. Phenformin significantly reduces cell viability in melanoma by targeting both CSC (ALDHhigh) and non-CSC cells and by significantly reducing the number of viable cells in ALDHhigh and ALDHlow-derived spheroids. Consistently, phenformin reduces melanoma cell viability and growth independently from SOX2 levels. Our results show that phenformin is able to affect both CSC and non-CSC melanoma cell viability and growth and suggests its potential use as anti-cancer therapy in melanoma.

Therapeutic potential of the metabolic modulator phenformin in targeting the stem cell compartment in melanoma

PubMed Central

Albini, Adriana; Longo, Caterina; Argenziano, Giuseppe; Grisendi, Giulia; Dominici, Massimo; Ciarrocchi, Alessia; Dallaglio, Katiuscia

2017-01-01

Melanoma is the most dangerous and treatment-resistant skin cancer. Tumor resistance and recurrence are due to the persistence in the patient of aggressive cells with stem cell features, the cancer stem cells (CSC). Recent evidences have shown that CSC display a distinct metabolic profile as compared to tumor bulk population: a promising anti-tumor strategy is therefore to target specific metabolic pathways driving CSC behavior. Biguanides (metformin and phenformin) are anti-diabetic drugs able to perturb cellular metabolism and displaying anti-cancer activity. However, their ability to target the CSC compartment in melanoma is not known. Here we show that phenformin, but not metformin, strongly reduces melanoma cell viability, growth and invasion in both 2D and 3D (spheroids) models. While phenformin decreases melanoma CSC markers expression and the levels of the pro-survival factor MITF, MITF overexpression fails to prevent phenformin effects. Phenformin significantly reduces cell viability in melanoma by targeting both CSC (ALDHhigh) and non-CSC cells and by significantly reducing the number of viable cells in ALDHhigh and ALDHlow-derived spheroids. Consistently, phenformin reduces melanoma cell viability and growth independently from SOX2 levels. Our results show that phenformin is able to affect both CSC and non-CSC melanoma cell viability and growth and suggests its potential use as anti-cancer therapy in melanoma. PMID:28036292

Effect of photobiomodulation on viability and proliferation of stem cells from exfoliated deciduous teeth under different nutritional conditions

NASA Astrophysics Data System (ADS)

Morato de Souza, Letícia; Guilherme Roque Rinco, Ugo; Aparecida Tavares Aguiar, Daniela; Aparecido de Almeida Junior, Luciano; Cosme-Silva, Leopoldo; Marchini Oliveira, Thais; Teixeira Marques, Nádia Carolina; Thiemy Sakai, Vivien

2018-02-01

This study aimed to evaluate the effect of different doses of low-level laser irradiation on the viability and proliferation of stem cells from exfoliated deciduous teeth (SHED) cultured under nutritional deficit (cellular stress) or regular nutritional conditions. SHED underwent irradiation by a red laser between 1.2 and 6.2 J cm-2. Prior to the irradiation, all groups received culture medium (MEMα, Eagle’s minimum essential medium alpha modification) supplemented with 1% of fetal bovine serum (FBS) for 1 h. After the irradiation, cells received MEMα supplemented with 10% of FBS (regular nutrition) or 1% of FBS (nutritional deficit). Cell viability and proliferation were respectively determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and crystal violet assays 6 and 24 h after irradiation (P  <  0.05). At 24 h, SHED under nutritional deficit showed lower viability and proliferation after 1.2 J cm-2 irradiation. All of the irradiated groups revealed significantly higher viability and proliferation in SHED maintained under nutritional deficit than in regular nutritional conditions, except in the 3.7 and 6.2 J cm-2 groups by MTT assay. In the crystal violet assay, SHED irradiated with 1.2 J cm-2 showed no difference between the different nutritional conditions. Decrease of FBS concentration in the culture medium seems to enhance the sensitivity of SHED to the effects of photobiomodulation therapy. Nutritional stress conditions improved cell viability and proliferation of SHED after laser irradiation, except for 1.2 J cm-2.

Human neural progenitor cells retain viability, phenotype, proliferation, and lineage differentiation when labeled with a novel iron oxide nanoparticle, Molday ION Rhodamine B

PubMed Central

Shen, Wei-Bin; Plachez, Celine; Chan, Amanda; Yarnell, Deborah; Puche, Adam C; Fishman, Paul S; Yarowsky, Paul

2013-01-01

Ultrasmall superparamagnetic iron-oxide particles (USPIOs) loaded into stem cells have been suggested as a way to track stem cell transplantation with magnetic resonance imaging, but the labeling, and post-labeling proliferation, viability, differentiation, and retention of USPIOs within the stem cells have yet to be determined for each type of stem cell and for each type of USPIO. Molday ION Rhodamine B™ (BioPAL, Worcester, MA, USA) (MIRB) has been shown to be a USPIO labeling agent for mesenchymal stem cells, glial progenitor cells, and stem cell lines. In this study, we have evaluated MIRB labeling in human neuroprogenitor cells and found that human neuroprogenitor cells are effectively labeled with MIRB without use of transfection reagents. Viability, proliferation, and differentiation properties are unchanged between MIRB-labeled neuroprogenitors cells and unlabeled cells. Moreover, MIRB-labeled human neuroprogenitor cells can be frozen, thawed, and replated without loss of MIRB or even without loss of their intrinsic biology. Overall, those results show that MIRB has advantageous properties that can be used for cell-based therapy. PMID:24348036

Applications of biological control in resistant host-pathogen systems.

PubMed

White, Steven M; White, K A Jane

2005-09-01

Insect pest species can have devastating effects on crops. Control of these insect pests is usually achieved by using chemical insecticides. However, there has been much cause for concern with their overuse. Consequently, research has been carried out into alternative forms of control, in particular biological control methods. Recent laboratory studies have indicated that these natural forms of control can induce resistant strains of insect pest. In this paper we present a discrete-time host-pathogen model to describe the interaction between a host (insect species) that can develop a resistant strain and a pathogen (biological control) that can be externally applied to the system. For this model we use a single-state variable for the host population. We show that the proportion of resistance in the population impacts on the viability of the host population. Moreover, when the host population does persist, we explore the interaction between host susceptibility and host population levels. The different scenarios which arise are explained ecologically in terms of trade-offs in intrinsic growth rates, disease susceptibility and intraspecific host competition for the resistant subclass.

Lidocaine cytotoxicity to the bovine articular chondrocytes in vitro: changes in cell viability and proteoglycan metabolism.

PubMed

Miyazaki, Tsuyoshi; Kobayashi, Shigeru; Takeno, Kenichi; Yayama, Takafumi; Meir, Adam; Baba, Hisatoshi

2011-07-01

A lot of studies on the effect of intra-articular injections are clinical, but many questions on the effect of lidocaine to articular chondrocytes remain unanswered. This study was performed to determine the effects of varying concentrations and exposure times of lidocaine on the viability and proteoglycan metabolism of chondrocytes in vitro. Cartilage was obtained from metatarsal joints of adult bovines. Chondrocytes in alginate beads were cultured in medium containing 6% fetal calf serum at 370 mOsmol at cell densities of 4 million cells/ml. They were then cultured for 24 h under 21% oxygen with 0.125, 0.25, 0.5, and 1% lidocaine and without lidocaine as control. The cell viability profile across intact beads was determined by manual counting using fluorescent probes and transmission electron microscopy. Lactate production was measured enzymatically as a marker of energy metabolism. Glycosaminoglycan (GAG) accumulation was measured using a modified dimethylmethylene blue assay. Cell viability decreased in a time- and dose-dependent manner in the concentration range of 0.125-1.0% lidocaine under the confocal microscope. Under the electron microscope, apoptosis increased as the concentration of lidocaine increased. GAG accumulation/tissue volume decreases as the concentration of lidocaine increased. However, GAG produced per million cells and the rate of lactate production per live cell were significantly higher for cells cultured at 0.5 and 1% lidocaine than the control group. Bovine chondrocytes cultured in alginate beads under high oxygen pressure are negatively influenced by increasing concentrations of lidocaine. Cell viability and proteoglycan production (GAG accumulation/tissue volume) decreased as the concentration of lidocaine increased. These data suggest caution in prolonged exposure of cartilage to high concentration lidocaine. Repeated joint injection of lidocaine potentially worsens osteoarthrosis by accelerating cartilage degradation.

Intercellular cytosolic transfer correlates with mesenchymal stromal cell rescue of umbilical cord blood cell viability during ex vivo expansion

PubMed Central

Chu, Pat P. Y.; Bari, Sudipto; Fan, Xiubo; Gay, Florence P. H.; Ang, Justina M. L.; Chiu, Gigi N. C.; Lim, Sai K.; Hwang, William Y. K.

2012-01-01

Background aims. Mesenchymal stromal cells (MSC) have been observed to participate in tissue repair and to have growth-promoting effects on ex vivo co-culture with other stem cells. Methods. In order to evaluate the mechanism of MSC support on ex vivo cultures, we performed co-culture of MSC with umbilical cord blood (UCB) mononuclear cells (MNC) (UCB-MNC). Results. Significant enhancement in cell growth correlating with cell viability was noted with MSC co-culture (defined by double-negative staining for Annexin-V and 7-AAD; P<0.01). This was associated with significant enhancement of mitochondrial membrane potential (P<0.01). We postulated that intercellular transfer of cytosolic substances between MSC and UCB-MNC could be one mechanism mediating the support. Using MSC endogenously expressing green fluorescent protein (GFP) or labeled with quantum dots (QD), we performed co-culture of UCB-MNC with these MSC. Transfer of these GFP and QD was observed from MSC to UCB-MNC as early as 24 h post co-culture. Transwell experiments revealed that direct contact between MSC and UCB-MNC was necessary for both transfer and viability support. UCB-MNC tightly adherent to the MSC layer exhibited the most optimal transfer and rescue of cell viability. DNA analysis of the viable, GFP transfer-positive UCB-MNC ruled out MSC transdifferentiation or MSC-UCB fusion. In addition, there was statistical correlation between higher levels of cytosolic transfer and enhanced UCB-MNC viability (P< 0.0001). Conclusions. Collectively, the data suggest that intercellular transfer of cytosolic materials could be one novel mechanism for preventing UCB cell death in MSC co-culture. PMID:22775077

Rapamycin toxicity in MIN6 cells and rat and human islets is mediated by the inhibition of mTOR complex 2 (mTORC2).

PubMed

Barlow, A D; Xie, J; Moore, C E; Campbell, S C; Shaw, J A M; Nicholson, M L; Herbert, T P

2012-05-01

Rapamycin (sirolimus) is one of the primary immunosuppressants for islet transplantation. Yet there is evidence that the long-term treatment of islet-transplant patients with rapamycin may be responsible for subsequent loss of islet graft function and viability. Therefore, the primary objective of this study was to elucidate the molecular mechanism of rapamycin toxicity in beta cells. Experiments were performed on isolated rat and human islets of Langerhans and MIN6 cells. The effects of rapamycin and the roles of mammalian target of rapamycin complex 2 (mTORC2)/protein kinase B (PKB) on beta cell signalling, function and viability were investigated using cell viability assays, insulin ELISA assays, kinase assays, western blotting, pharmacological inhibitors, small interfering (si)RNA and through the overproduction of a constitutively active mutant of PKB. Rapamycin treatment of MIN6 cells and islets of Langerhans resulted in a loss of cell function and viability. Although rapamycin acutely inhibited mTOR complex 1 (mTORC1), the toxic effects of rapamycin were more closely correlated to the dissociation and inactivation of mTORC2 and the inhibition of PKB. Indeed, the overproduction of constitutively active PKB protected islets from rapamycin toxicity whereas the inhibition of PKB led to a loss of cell viability. Moreover, the selective inactivation of mTORC2 using siRNA directed towards rapamycin-insensitive companion of target of rapamycin (RICTOR), mimicked the toxic effects of chronic rapamycin treatment. This report provides evidence that rapamycin toxicity is mediated by the inactivation of mTORC2 and the inhibition of PKB and thus reveals the molecular basis of rapamycin toxicity and the essential role of mTORC2 in maintaining beta cell function and survival.

Effects of Pseudomonas aeruginosa virulence factor pyocyanin on human urothelial cell function and viability.

PubMed

McDermott, Catherine; Chess-Williams, Russ; Grant, Gary D; Perkins, Anthony V; McFarland, Amelia J; Davey, Andrew K; Anoopkumar-Dukie, Shailendra

2012-03-01

We determined the effects of Pseudomonas aeruginosa virulence factor pyocyanin on human urothelial cell viability and function in vitro. RT4 urothelial cells were treated with pyocyanin (1 to 100 μM) for 24 hours. After exposure the treatment effects were measured according to certain end points, including changes in urothelial cell viability, reactive oxygen species formation, caspase-3 activity, basal and stimulated adenosine triphosphate release, SA-β-gal activity and detection of acidic vesicular organelles. The 24-hour pyocyanin treatment resulted in a concentration dependent decrease in cell viability at concentrations of 25 μM or greater, and increases in reactive oxygen species formation and caspase-3 activity at 25 μM or greater. Basal adenosine triphosphate release was significantly decreased at all tested pyocyanin concentrations while stimulated adenosine triphosphate release was significantly inhibited at pyocyanin concentrations of 12.5 μM or greater with no significant stimulated release at 100 μM. Pyocyanin treated RT4 cells showed morphological characteristics associated with cellular senescence, including SA-β-gal expression. This effect was not evident at 100 μM pyocyanin and may have been due to apoptotic cell death, as indicated by increased caspase-3 activity. An increase in acridine orange stained vesicular-like organelles was observed in RT4 urothelial cells after pyocyanin treatment. Exposure to pyocyanin alters urothelial cell viability, reactive oxygen species production and caspase-3 activity. Treatment also results in cellular senescence, which may affect the ability of urothelium to repair during infection. The virulence factor depressed stimulated adenosine triphosphate release, which to our knowledge is a novel finding with implications for awareness of bladder filling in patients with P. aeruginosa urinary tract infection. Copyright © 2012 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

HIV-1 Protease in the Fission Yeast Schizosaccharomyces pombe.

PubMed

Benko, Zsigmond; Elder, Robert T; Li, Ge; Liang, Dong; Zhao, Richard Y

2016-01-01

HIV-1 protease (PR) is an essential viral enzyme. Its primary function is to proteolyze the viral Gag-Pol polyprotein for production of viral enzymes and structural proteins and for maturation of infectious viral particles. Increasing evidence suggests that PR cleaves host cellular proteins. However, the nature of PR-host cellular protein interactions is elusive. This study aimed to develop a fission yeast (Schizosaccharomyces pombe) model system and to examine the possible interaction of HIV-1 PR with cellular proteins and its potential impact on cell proliferation and viability. A fission yeast strain RE294 was created that carried a single integrated copy of the PR gene in its chromosome. The PR gene was expressed using an inducible nmt1 promoter so that PR-specific effects could be measured. HIV-1 PR from this system cleaved the same indigenous viral p6/MA protein substrate as it does in natural HIV-1 infections. HIV-1 PR expression in fission yeast cells prevented cell proliferation and induced cellular oxidative stress and changes in mitochondrial morphology that led to cell death. Both these PR activities can be prevented by a PR-specific enzymatic inhibitor, indinavir, suggesting that PR-mediated proteolytic activities and cytotoxic effects resulted from enzymatic activities of HIV-1 PR. Through genome-wide screening, a serine/threonine kinase, Hhp2, was identified that suppresses HIV-1 PR-induced protease cleavage and cell death in fission yeast and in mammalian cells, where it prevented PR-induced apoptosis and cleavage of caspase-3 and caspase-8. This is the first report to show that HIV-1 protease is functional as an enzyme in fission yeast, and that it behaves in a similar manner as it does in HIV-1 infection. HIV-1 PR-induced cell death in fission yeast could potentially be used as an endpoint for mechanistic studies, and this system could be used for developing a high-throughput system for drug screenings.

The effect of five artificial sweeteners on Caco-2, HT-29 and HEK-293 cells.

PubMed

van Eyk, Armorel Diane

2015-01-01

Artificial sweeteners (AS) have been associated with tumor development (including colon cancer) in both animals and humans although evidence has been conflicting. Additional research was thus conducted by studying the effects of 5 AS on the morphology, cell proliferation and DNA in cells by utilizing Caco-2, HT-29 (colon) and HEK-293 (kidney) cell lines. Cells were exposed to sodium cyclamate, sodium saccharin, sucralose and acesulfame-K (0-50 mM) and aspartame (0-35 mM) over 24, 48 and 72 hours. Morphological changes were presented photographically and % cell viability was determined by using the MTT cell viability assay. Possible DNA damage (comet assay) induced by the AS (0.1, 1 and 10 mM, treated for 24, 48 and 72 hours) was studied. The appearance of "comets" was scored from no damage to severe damage (0-4). Cells became flatter and less well defined at higher AS concentrations (>10 mM). At concentrations >10 mM, decreased cell viability was noted with both increasing concentration and increasing incubation time for all cell lines tested. In general, HEK-293 cells seemed to be less affected then the colon cancer cells. Sucralose and sodium saccharin seemed to elicit the greatest degree of DNA fragmentation of all the sweeteners tested in all the cell lines used. Morphological cell alterations, cell viability and DNA fragmentation seemed to be more in the colon cancer cells. Further studies have to be performed to clarify mechanisms involved causing these alterations in mammalian cells.

Towards gene banking amphibian maternal germ lines: short-term incubation, cryoprotectant tolerance and cryopreservation of embryonic cells of the frog, Limnodynastes peronii.

PubMed

Lawson, Bianca; Clulow, Simon; Mahony, Michael J; Clulow, John

2013-01-01

Gene banking is arguably the best method available to prevent the loss of genetic diversity caused by declines in wild populations, when the causes of decline cannot be halted or reversed. For one of the most impacted vertebrate groups, the amphibians, gene banking technologies have advanced considerably, and gametes from the male line can be banked successfully for many species. However, cryopreserving the female germ line remains challenging, with attempts at cryopreserving oocytes unsuccessful due to their large size and yolk content. One possible solution is to target cryopreservation of early embryos that contain the maternal germ line, but consist of smaller cells. Here, we investigate the short term incubation, cryoprotectant tolerance, and cryopreservation of dissociated early embryonic cells from gastrulae and neurulae of the Striped Marsh Frog, Limnodynastes peronii. Embryos were dissociated and cells were incubated for up to 24 hours in various media. Viability of both gastrula and neurula cells remained high (means up to 40-60%) over 24 hours of incubation in all media, although viability was maintained at a higher level in Ca(2+)-free Simplified Amphibian Ringer; low speed centrifugation did not reduce cell viability. Tolerance of dissociated embryonic cells was tested for two cryoprotectants, glycerol and dimethyl sulphoxide; dissociated cells of both gastrulae and neurulae were highly tolerant to both-indeed, cell viability over 24 hours was higher in media containing low-to-medium concentrations than in equivalent cryoprotectant-free media. Viability over 24 hours was lower in concentrations of cryoprotectant higher than 10%. Live cells were recovered following cryopreservation of both gastrula and neurula cells, but only at low rates. Optimal cryodiluents were identified for gastrula and neurula cells. This is the first report of a slow cooling protocol for cryopreservation of amphibian embryonic cells, and sets future research directions for cryopreserving amphibian maternal germ lines.

Effects of Spinosad, Imidacloprid, and Lambda-cyhalothrin on Survival, Parasitism, and Reproduction of the Aphid Parasitoid Aphidius colemani.

PubMed

D'Ávila, Vinicius A; Barbosa, Wagner F; Guedes, Raul N C; Cutler, G Christopher

2018-05-28

Insecticides can affect biological control by parasitoids. Here, we examined the lethal and sublethal effects of two conventional insecticides, imidacloprid and lambda-cyhalothrin, and a reduced-risk bioinsecticide, spinosad, on the aphid parasitoid Aphidius colemani Viereck (Hymenoptera: Braconidae). Concentration-mortality curves generated from insecticide residue bioassays found that wasps were nearly 20-fold more susceptible to spinosad than imidacloprid and lambda-cyhalothrin. Imidacloprid and lambda-cyhalothrin compromised adult parasitoid longevity, but not as dramatically as spinosad: concentrations >200 ng spinosad/cm2 reduced wasp longevity by half. Imidacloprid and lambda-cyhalothrin also compromised aphid parasitism by wasps. Although increasing imidacloprid concentrations led to increased host viability and reduced progeny production, lambda-cyhalothrin did not affect viability of parasitized hosts or parasitoid progeny production in a dose-dependent manner. Our results demonstrate that reduced risk bioinsecticide products like spinosad can be more toxic to biological control agents than certain conventional insecticides.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burch, S.W.; Goven, A.J.; Fitzpatrick, L.C.

An in vitro assay has been developed for rapid (48 h) evaluation of cytotoxic effects of exposure (24 h) of earthworm coelomocytes. The assay, inhibition of phagocytosis (24 h) of stained yeast cells and cell viability, links a traditional soil bioassay organism (Lumbricus terrestris) with a laboratory protocol for use in evaluating physical/chemical fractions resulting from terrestrial TIE manipulations. The assay was developed using copper sulfate as a reference toxicant. Copper exposures as low as 2--4 pg/ml. resulted in 20--60% inhibition of phagocytosis without significant decrease in cell viability. Exposures above 10 pg/ml resulted in reduced cell viability and inhibitionmore » of phagocytosis. The assay was successfully applied to terrestrial TIE fractions derived from extractions of soil from a PCP contaminated wood treatment site.« less

Potential for Monitoring Gut Microbiota for Diagnosing Infections and Graft-versus-Host Disease in Cancer and Stem Cell Transplant Patients.

PubMed

Koh, Andrew Y

2017-11-01

Gut microbiota, the collective community of microorganisms inhabiting the intestine, have been shown to provide many beneficial functions for the host. Recent advances in next-generation sequencing and advanced molecular biology approaches have allowed researchers to identify gut microbiota signatures associated with disease processes and, in some cases, establish causality and elucidate underlying mechanisms. This report reviews 3 commonly used methods for studying the gut microbiota and microbiome (the collective genomes of the gut microorganisms): 16S rRNA gene sequencing, bacterial group or species-specific quantitative polymerase chain reaction (qPCR), and metagenomic shotgun sequencing (MSS). The technical approaches and resources needed for each approach are outlined, and advantages and disadvantages for each approach are summarized. The findings regarding the role of the gut microbiota in the health of patients with cancer and stem cell transplant (SCT) patients (specifically in modulating the development of gut-derived bacterial infections and a posttransplant immune-mediated complication known as graft-vs-host-disease) are reviewed. Finally, there is discussion of the potential viability of these approaches in the actual clinical treatment of cancer and SCT patients. Advances in next-generation sequencing have revolutionized our understanding of the importance of the gut microbiome to human health. Both 16S rRNA gene sequencing and MSS are currently too labor-intensive or computationally burdensome to incorporate into real-time clinical monitoring of gut microbiomes. Yet, the lessons learned from these technologies could be adapted to currently used methods (e.g., qPCR) that could then be rigorously tested in the clinical care of these patients. © 2017 American Association for Clinical Chemistry.

BAY 41-2272, a soluble guanylate cyclase agonist, activates human mononuclear phagocytes

PubMed Central

Soeiro-Pereira, PV; Falcai, A; Kubo, CA; Oliveira-Júnior, EB; Marques, OC; Antunes, E; Condino-Neto, A

2012-01-01

BACKGROUND AND PURPOSE Phagocyte function is critical for host defense against infections. Defects in phagocytic function lead to several primary immunodeficiencies characterized by early onset of recurrent and severe infections. In this work, we further investigated the effects of BAY 41-2272, a soluble guanylate cyclase (sGC) agonist, on the activation of human peripheral blood monocytes (PBM) and THP-1 cells. EXPERIMENTAL APPROACH THP-1 cells and PBM viability was evaluated by methylthiazoletetrazolium assay; reactive oxygen species production by lucigenin chemiluminescence; gene and protein expression of NAPDH oxidase components by qRT-PCR and Western blot analysis, respectively; phagocytosis and microbicidal activity by co-incubation, respectively, with zymosan and Escherichia coli; and cytokine release by elisa. KEY RESULTS BAY 41-2272, compared with the untreated group, increased spreading of monocytes by at least 35%, superoxide production by at least 50%, and gp91PHOX and p67PHOX gene expression 20 to 40 times, in both PBM and THP-1 cells. BAY 41-2272 also augmented phagocytosis of zymosan particles threefold compared with control, doubled microbicidal activity against E. coli and enhanced the release of TNF-α and IL-12p70 by both PBM and THP-1 cells. Finally, by inhibiting sGC with ODQ, we showed that BAY 41-2272-induced superoxide production and phagocytosis is not dependent exclusively on sGC activation. CONCLUSIONS AND IMPLICATIONS In addition to its ability to induce vasorelaxation and its potential application for therapy of vascular diseases, BAY 41-2272 was shown to activate human mononuclear phagocytes. Hence, it is a novel pro-inflammatory drug that may be useful for controlling infections in the immunocompromised host. PMID:22044316

In vitro biological action of aqueous extract from roots of Physalis angulata against Leishmania (Leishmania) amazonensis.

PubMed

da Silva, Raquel Raick P; da Silva, Bruno J M; Rodrigues, Ana Paula D; Farias, Luis Henrique S; da Silva, Milton N; Alves, Danila Teresa V; Bastos, Gilmara N T; do Nascimento, José Luiz M; Silva, Edilene O

2015-07-24

Leishmaniasis is an infectious disease caused by various species of the protozoan parasites of the Leishmania genus and transmitted by phlebotomine sandflies. The protozoa multiply in phagocytic cells, mainly macrophages, which play an important role defending the organism from pathogens. The most effective treatment for leishmaniasis is the chemotherapy and besides the high cost, these drugs are toxic and require a long period of treatment. Currently, some herbal products are considered an important alternative source of a new leishmanicidal agent, which includes the plant Physalis angulata, . We evaluated effects of an aqueous extract from roots of Physalis angulata (AEPa) on Leishmania proliferation, morphology and also determined whether physalins were present in the extract contributing to the knowledge of its pharmacological efficacy. Morphological alterations were determined by light microscopy, transmission and scanning electron microscopy. Host cell viability was evaluated by MTT, and propidium iodide. AEPa were submitted in full HRESITOF analysis. AEPa promoted a dose-dependent reduction on promastigotes (IC50 = 39.5 μg/mL ± 5.1) and amastigotes (IC50 = 43.4 μg/mL ± 10.1) growth. This growth inhibition was associated with several morphological alterations observed in promastigote forms. No cytotoxic effect in mammalian cells was detected (IC50 > 4000 μg/mL). Furthemore, the presence of physalins A, B, D, E, F, G and H were described, for the first time, in the P. angulata root. Results demonstrate that AEPa effectively promotes antileishmanial activity with several important morphological alterations and has no cytotoxic effects on host cells.

In vitro effects of four macrolides (roxithromycin, spiramycin, azithromycin (CP-62,993), and A-56268) on Toxoplasma gondii

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, H.R.; Pechere, J.C.

1988-04-01

The effect of four macrolides against intracellular Toxoplasma gondii was determined in three different in vitro systems. Unactivated murine peritoneal macrophages were infected with the virulent RH strain of T. gondii. The activity of the macrolides was first measured with (/sup 3/H)uracil, which is incorporated by the parasite but not the host cell. The 50% inhibitory concentrations (IC50s) and 95% confidence limits were calculated at 54 (38 to 73), 140 (98 to 201), 147 (101 to 214), and 246 (187 to 325) micron for roxithromycin, azithromycin (CP-62,993), A-56268, and spiramycin, respectively. Inhibition of Toxoplasma growth was confirmed by microscopic examinationmore » of the infected macrophages after treatment with roxithromycin. Compared with untreated controls, roxithromycin concentrations near the IC50s decreased the number of infected cells, the number of tachyzoites per vacuole, and the number of cells containing rosettes (i.e., clusters of more than eight tachyzoites). After treatment with the four macrolides, tachyzoites were released from the macrophages and subcultured in HeLa cells, which are nonprofessional phagocytes, to assess the viability of the remaining parasites. This showed that the macrolides at concentrations corresponding to four times their 90% inhibitory concentrations (IC90s) had no significant killing effect. At 8 times the IC90, roxithromycin showed an incomplete killing effect, similar to that of the combination of pyrimethamine (0.41 microM)-sulfadiazine (99.42 microM). All macrolides tested showed inhibitory effects against intracellular T. gondii, but amounts of azithromycin and A-56268 corresponding to the IC90 appeared to be toxic against the host macrophages, which might have had nonspecific activity against Toxoplasma metabolism.« less

Effect of laser treatment on the attachment and viability of mesenchymal stem cell responses on shape memory NiTi alloy.

PubMed

Chan, C W; Hussain, I; Waugh, D G; Lawrence, J; Man, H C

2014-09-01

The objectives of this study were to investigate the effect of laser-induced surface features on the morphology, attachment and viability of mesenchymal stem cells (MSCs) at different periods of time, and to evaluate the biocompatibility of different zones: laser-melted zone (MZ), heat-affected zone (HAZ) and base metal (BM) in laser-treated NiTi alloy. The surface morphology and composition were studied by scanning electron microscope (SEM) and X-ray photoemission spectroscopy (XPS), respectively. The cell morphology was examined by SEM while the cell counting and viability measurements were done by hemocytometer and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric assay. The results indicated that the laser-induced surface features, such as surface roughening, presence of anisotropic dendritic pattern and complete surface Ni oxidation were beneficial to improve the biocompatibility of NiTi as evidenced by the highest cell attachment (4 days of culture) and viability (7 days of culture) found in the MZ. The biocompatibility of the MZ was the best, followed by the BM with the HAZ being the worst. The defective and porous oxide layer as well as the coarse grained structure might attribute to the inferior cell attachment (4 days of culture) and viability (7 days of culture) on the HAZ compared with the BM which has similar surface morphology. Copyright © 2014 Elsevier B.V. All rights reserved.

Viability of a human melanoma cell after single and combined treatment with fotemustine, dacarbazine, and proton irradiation.

PubMed

Petrović, Ivan M; Korićanac, Lela B; Todorović, Danijela V; Ristić-Fira, Aleksandra M; Valastro, Lucia M; Privitera, Giuseppe; Cuttone, Giacomo

2007-01-01

Viability of human HTB140 melanoma cells after being exposed to fotemustine (FM) and dacarbazine (DTIC) as well as to proton irradiation was studied. Effects of 100 and 250 microM drugs were assessed after incubation of 6, 24, 48, 72, and 96 h. Irradiations were performed with 62 MeV therapeutic protons, delivering to the cell monolayer single doses of 2, 4, 8, 12, and 16 Gy. Viability was evaluated 7 days after irradiation. Inactivation level was estimated using microtetrasolium (MTT) and sulforhodamine B (SRB) assays. Combined effects of each drug and protons, were carried out using the same drug concentrations. Proton doses applied were those used in therapy, that is, 12 and 16 Gy. With the increase of drug concentration or irradiation dose, level of cell inactivation reached approximately 60%, 48 h after drug treatment or 7 days after irradiation at 16 Gy. Considering the rate of drug concentrations used, as well as the level of doses applied, it appears that HTB140 cells are more resistant to proton irradiation than to alkylating agents tested. The combined treatment with FM or DTIC and protons did not show significant changes of cell viability as compared to the effects of single agents. Since the time point for measuring cumulative effects of drug and irradiation was 48 h post irradiation, it seems that the obtained level of viability could be attributed primarily to the effects of drugs.

Residual HEMA and TEGDMA Release and Cytotoxicity Evaluation of Resin-Modified Glass Ionomer Cement and Compomers Cured with Different Light Sources

PubMed Central

Botsali, Murat Selim; Kuşgöz, Adem; Altintaş, Subutay Han; Ülker, Hayriye Esra; Kiliç, Serdar; Başak, Feridun; Ülker, Mustafa

2014-01-01

The purpose of this study was first to evaluate the elution of 2-hydroxyethyl methacrylate (HEMA) and triethylene glycol dimethacrylate (TEGDMA) monomers from resin-modified glass ionomer cement (RMGIC) and compomers cured with halogen and light-emitting diode (LED) light-curing units (LCUs). The effect of cured materials on the viability of L929 fibroblast cells was also evaluated. One RMGIC (Ketac N100) and two compomers (Dyract Extra and Twinkystar) were tested. Materials were prepared in teflon disks and light-cured with LED or halogen LCUs. The residual monomers of resin materials in solution were identified using high-performance liquid chromatography. The fibroblast cells' viability was analyzed using MTT assay. The type of LCU did not have a significant effect on the elution of HEMA and TEGDMA. A greater amount of HEMA than TEGMDA was eluted. The amount of TEGDMA eluted from Twinkystar was greater than Dyract Extra (P < 0.05) when cured with a halogen LCU. All material-LCU combinations decreased the fibroblast cells' viability more than the control group (P < 0.01), except for Dyract Extra cured with a halogen LCU (P > 0.05). Curing with the LED LCU decreased the cells' viability more than curing with the halogen LCU for compomers. For Ketac N100, the halogen LCU decreased the cells' viability more than the LED LCU. PMID:24592149

The influence of size and charge of chitosan/polyglutamic acid hollow spheres on cellular internalization, viability and blood compatibility.

PubMed

Dash, Biraja C; Réthoré, Gildas; Monaghan, Michael; Fitzgerald, Kathleen; Gallagher, William; Pandit, Abhay

2010-11-01

Polymeric hollow spheres can be tailored as efficient carriers of various therapeutic molecules due to their tunable properties. However, the entry of these synthetic vehicles into cells, their cell viability and blood compatibility depend on their physical and chemical properties e.g. size, surface charge. Herein, we report the effect of size and surface charge on cell viability and cellular internalization behaviour and their effect on various blood components using chitosan/polyglutamic acid hollow spheres as a model system. Negatively charged chitosan/polyglutamic acid hollow spheres of various sizes 100, 300, 500 and 1000 nm were fabricated using a template based method and covalently surface modified using linear polyethylene glycol and methoxyethanol amine to create a gradient of surface charge from negative to neutrally charged spheres respectively. The results here suggest that both size and surface charge have a significant influence on the sphere's behaviour, most prominently on haemolysis, platelet activation, plasma recalcification time, cell viability and internalization over time. Additionally, cellular internalization behaviour and viability was found to vary with different cell types. These results are in agreement with those of inorganic spheres and liposomes, and can serve as guidelines for tailoring polymeric solid spheres for specific desired applications in biological and pharmaceutical fields, including the design of nanometer to submicron-sized delivery vehicles. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

An In vitro Comparison of Coconut Water, Milk, and Saline in Maintaining Periodontal Ligament Cell Viability

PubMed Central

D’Costa, Vivian Flourish; Bangera, Madhu Keshava; Kini, Shravan; Kutty, Shakkira Moosa; Ragher, Mallikarjuna

2017-01-01

Background and Objectives: Two of the most critical factors affecting the prognosis of an avulsed tooth after replantation are extraoral dry time and the storage media in which the tooth is placed before treatment is rendered. The present study is undertaken to evaluate the periodontal ligament (PDL) cell viability after storage of teeth in different storage media, namely, coconut water, milk, and saline. Materials and Methods: Forty sound human premolars undergoing extraction for orthodontic purpose were selected. The teeth were allowed to lie dry on sand/mud for 30 min followed by which they were randomly divided and stored in three different media, i.e., coconut water, milk, and saline. After 45-min storage in their respective media, the root surface was then scraped for PDL tissue. Results: The ANOVA and Newman–Keuls post hoc procedure for statistical analysis of viable cell count under a light microscope using hemocytometer demonstrated that coconut water preserved significantly more PDL cells viable (P < 0.05) compared with milk and saline. Conclusion: Storage media help in preserving the viability of PDL cells when immediate replantation is not possible. This study evaluated the posttraumatic PDL cells’ viability following storage in three different storage media. Within the parameters of this study, it was found that coconut water is the most effective media for maintaining the viability of PDL. PMID:29284947

Effect of storage time on the viability of cryopreserved bovine spermatozoa

USDA-ARS?s Scientific Manuscript database

Long term cryopreserved semen viability can impact the National Animal Germplasm Program’s (NAGP) sampling strategy and ability to reconstitute livestock populations. Therefore, the purpose of this project was to determine if prolonged storage of cryopreserved sperm impacts cell viability. Cryoprese...

Hyaluronic acid increases tendon derived cell viability and collagen type I expression in vitro: Comparative study of four different Hyaluronic acid preparations by molecular weight.

PubMed

Osti, Leonardo; Berardocco, Martina; di Giacomo, Viviana; Di Bernardo, Graziella; Oliva, Francesco; Berardi, Anna C

2015-10-06

Hyaluronic Acid (HA) has been already approved by Food and Drug Administration (FDA) for osteoarthritis (OA), while its use in the treatment of tendinopathy is still debated. The aim of this study was to evaluate in human rotator cuff tendon derived cells the effects of four different HA on cell viability, proliferation, apoptosis and the expression of collagen type I and collagen type III. An in vitro model was developed on human tendon derived cells from rotator cuff tears to study the effects of four different HA preparations (Ps) (sodium hyaluronate MW: 500-730 KDa - Hyalgan®, 1000 kDa Artrosulfur HA®, 1600 KDa Hyalubrix® and 2200 KDa Synolis-VA®) at various concentrations. Tendon derived cells morphology were evaluated after 0, 7 and 14 d of culture. Viability, proliferation, apoptosis were evaluated after 0, 24 and 48 h of culture. The expression and deposition of collagen type I and collagen type III were evaluated after 1, 7 and 14 d of culture. All HAPs tested increased viability and proliferation, in dose dependent manner. HAPs already reduce apoptosis at 24 h compared to control cells (without HAPs). Furthermore, HAPs stimulated the synthesis of collagen type I in a dose dependent fashion over 14 d, without increase in collagen type III; moreover, in the presence of Synolis-VA® the expression and deposition of collagen type I was significantly higher as compare with the other HAPs. HAPs enhanced viability, proliferation and expression of collagen type I in tendon derived cells.

[Cytotoxicity induced by gasoline engine exhausts associated with oxidative stress].

PubMed

Che, Wangjun; Zhang, Zunzhen; Wu, Mei; Wang, Ling

2008-09-01

To evaluate the relationship between cytotoxic effects of the extracts of condensate, particulates and semivolatile organic compounds from gasoline engine exhausts (EGE) and oxidative stress. After A549 cells were treated with various concentrations of EGE for 2h, and cell viabilities were detected induced by EGE were examined by MTT assay. Meanwhile, the reactive oxygen species (ROS) in A549 cells induced by EGE were examined, 2',7'-dichlorodihy-drofluorescin diacetate (DCFH-DA) was used to catch ROS and its level measured by value of pixel fluorescence intensity. Furthermore, A549 cells pretreated with different concentrations of glutathione (GSH) were exposed to various concentrations of EGE for 2h, and then cell viabilities were examined. Viabilities of A549 cells significantly decreased in comparison to the solvent group when the concentrations of EGE were more than 3.9 ml/ml (P < 0.05). There were a dose-response relationships between the viabilities and the concentration of EGE (r = -0.81, P < 0.01). At the concentrations of 31.3 ml/ml and 62.5 ml/ml, the values of pixel fluorescence intensity were (125.0 +/- 19.2) and (168.9 +/- 16.9), which were significantly higher than those of control (8.5 +/- 1.4). In addition, the viabilities of cells pretreated with GSH gradually increased with the increases of the concentrations of GSH. There were also a significant difference between the pretreated and non-pretreated group at the concentrations of 0.5 mmol/L and 1.0 mmol/L. Oxidative stress could be one of the mechanisms of cytotoxic effects of EGE.

Reduced Neurite Density in Neuronal Cell Cultures Exposed to Serum of Patients with Bipolar Disorder

PubMed Central

Wollenhaupt-Aguiar, Bianca; Pfaffenseller, Bianca; Chagas, Vinicius de Saraiva; Castro, Mauro A A; Passos, Ives Cavalcante; Kauer-Sant’Anna, Márcia; Kapczinski, Flavio

2016-01-01

Background: Increased inflammatory markers and oxidative stress have been reported in serum among patients with bipolar disorder (BD). The aim of this study is to assess whether biochemical changes in the serum of patients induces neurotoxicity in neuronal cell cultures. Methods: We challenged the retinoic acid-differentiated human neuroblastoma SH-SY5Y cells with the serum of BD patients at early and late stages of illness and assessed neurite density and cell viability as neurotoxic endpoints. Results: Decreased neurite density was found in neurons treated with the serum of patients, mostly patients at late stages of illness. Also, neurons challenged with the serum of late-stage patients showed a significant decrease in cell viability. Conclusions: Our findings showed that the serum of patients with bipolar disorder induced a decrease in neurite density and cell viability in neuronal cultures. PMID:27207915

Nur77 inhibits oxLDL induced apoptosis of macrophages via the p38 MAPK signaling pathway

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shao, Qin; Han, Fei; Peng, Shi

2016-03-18

The interaction between macrophages and oxLDL plays a crucial role in the initiation and progression of atherosclerosis. As a key initiator in a number of plaque promoting processes, oxLDL induces variable effects such as cell apoptosis or proliferation. Orphan nuclear receptor Nur77 is potently induced in macrophages by diverse stimuli, suggesting that it is of importance in vascular inflammation resulting in atherosclerosis, but whether Nur77 induction is detrimental or protective is unclear. In our study, we explore the role of Nur77 in the regulation of oxLDL-induced macrophage apoptosis and the signaling pathways that are involved. We found that oxLDL inducedmore » Nur77 expression in a dose and time dependent fashion, and cell viability was decreased in parallel. To determine whether Nur77 induction contributes to the loss of cell viability or is a protective mechanism, the effect of Nur77 overexpression was examined. Importantly, Nur77 overexpression inhibited the oxLDL-induced decrease of cell viability, inhibited the production of apoptotic bodies and restored DNA synthesis following oxLDL exposure. Furthermore, we found that Nur77 induction is mediated through the p38 MAPK signaling pathway. After pretreatment with SB203580, cell viability was decreased, the expression of CyclinA2 and PCNA was attenuated and the percentage of cell apoptosis was enhanced. Likewise, Nur77 overexpression increased the expression of the cell cycle genes PCNA and p21, and attenuated the increase in caspase-3. On the other hand, knockdown of Nur77 expression by specific siRNA resulted in the increased expression of caspase 3. The results demonstrate that Nur77 is induced by oxLDL via the p38 MAPK signaling pathway, which is involved in the regulation of cell survival. Nur77 enhanced cell survival via suppressing apoptosis, without affecting cell proliferation of activated macrophages, which may be beneficial in patients with atherosclerosis. - Highlights: • oxLDL could induce Nur77 expression. • Nur77 overexpression inhibited oxLDL-induced cell viability, production of apoptotic bodies and restored DNA synthesis. • Cell viability, CyclinA2 and PCNA expression and cell apoptosis were mediated through the p38 MAPK signaling pathway. • Nur77 overexpression mediated the expression of genes PCNA, p21, and caspase-3.« less

Diminished origin licensing capacity specifically sensitises tumour cells to replication stress

PubMed Central

Zimmerman, Kristin M.; Jones, Rebecca M.; Petermann, Eva; Jeggo, Penelope A.

2013-01-01

Previous studies have shown that dormant licensed replication origins can be exploited to enhance recovery from replication stress. Since tumour cells express high levels of origin licensing proteins, we examined whether depletion of such factors might specifically sensitise tumour versus non-tumour cells. Consistent with previous findings, we observed that three tumour-derived cell lines overexpress ORC1, a licensing component, compared to four non-tumour cell lines and that a greater level of ORC1 was required to maintain viability in the tumour cells. We determined siRNA-mediated knockdown conditions for each line that maximally reduced ORC1 but did not impact upon viability, which we considered would optimally deplete dormant origins. ORC1 depletion hypersensitised the tumour-derived cells to hydroxyurea (HU) and H202 but did not affect the sensitivity of the non-tumour lines. Similar results were observed following depletion of ORC6 or CDC6. Further, co-depletion of p53 and ORC1 modestly impaired viability of 1BR3hTERT non-tumour fibroblasts and more dramatically caused hypersensitivity to HU. Finally, overexpression of the c-Myc oncogene combined with ORC1 depletion in non-tumour BJhTERT cells diminished viability. Collectively, these findings suggest that tumour cells may have a reliance on origin licensing capacity, suggesting that licensing factors could represent a target for drug-based cancer therapy. PMID:23364533

The postmitotic Saccharomyces cerevisiae after spaceflight showed higher viability

NASA Astrophysics Data System (ADS)

Yi, Zong-Chun; Li, Xiao-Fei; Wang, Yan; Wang, Jie; Sun, Yan; Zhuang, Feng-Yuan

2011-06-01

The budding yeast Saccharomyces cerevisiae has been proposed as an ideal model organism for clarifying the biological effects caused by spaceflight conditions. The postmitotic S. cerevisiae cells onboard Practice eight recoverable satellite were subjected to spaceflight for 15 days. After recovery, the viability, the glycogen content, the activities of carbohydrate metabolism enzymes, the DNA content and the lipid peroxidation level in yeast cells were analyzed. The viability of the postmitotic yeast cells after spaceflight showed a three-fold increase as compared with that of the ground control cells. Compared to the ground control cells, the lipid peroxidation level in the spaceflight yeast cells markedly decreased. The spaceflight yeast cells also showed an increase in G2/M cell population and a decrease in Sub-G1 cell population. The glycogen content and the activities of hexokinase and succinate dehydrogenase significantly decreased in the yeast cells after spaceflight. In contrast, the activity of malate dehydrogenase showed an obvious increase after spaceflight. These results suggested that microgravity or spaceflight could promote the survival of postmitotic S. cerevisiae cells through regulating carbohydrate metabolism, ROS level and cell cycle progression.

Malva sylvestris Inhibits Inflammatory Response in Oral Human Cells. An In Vitro Infection Model

PubMed Central

Benso, Bruna; Rosalen, Pedro Luiz; Alencar, Severino Matias; Murata, Ramiro Mendonça

2015-01-01

The aim of this study was to investigate the in vitro anti-inflammatory activity of Malva sylvestris extract (MSE) and fractions in a co-culture model of cells infected by Aggregatibacter actinomycetemcomitans. In addition, we evaluated the phytochemical content in the extract and fractions of M. sylvestris and demonstrated that polyphenols were the most frequent group in all samples studied. An in vitro dual-chamber model to mimic the periodontal structure was developed using a monolayer of epithelial keratinocytes (OBA-9) and a subepithelial layer of fibroblasts (HGF-1). The invasive periodontopathogen A. actinomycetemcomitans (D7S-1) was applied to migrate through the cell layers and induce the synthesis of immune factors and cytokines in the host cells. In an attempt to analyze the antimicrobial properties of MSE and fractions, a susceptibility test was carried out. The extract (MIC 175 μg/mL, MBC 500μg/mL) and chloroform fraction (MIC 150 μg/mL, MBC 250 μg/mL) were found to have inhibitory activity. The extract and all fractions were assessed using a cytotoxicity test and results showed that concentrations under 100 μg/mL did not significantly reduce cell viability compared to the control group (p > 0.05, viability > 90%). In order to analyze the inflammatory response, transcriptional factors and cytokines were quantified in the supernatant released from the cells. The chloroform fraction was the most effective in reducing the bacterial colonization (p< 0.05) and controlling inflammatory mediators, and promoted the down-regulation of genes including IL-1beta, IL-6, IL-10, CD14, PTGS, MMP-1 and FOS as well as the reduction of the IL-1beta, IL-6, IL-8 and GM-CSF protein levels (p< 0.05). Malva sylvestris and its chloroform fraction minimized the A. actinomycetemcomitans infection and inflammation processes in oral human cells by a putative pathway that involves important cytokines and receptors. Therefore, this natural product may be considered as a successful dual anti-inflammatory–antimicrobial candidate. PMID:26479870

BMI-1 suppression increases the radiosensitivity of oesophageal carcinoma via the PI3K/Akt signaling pathway.

PubMed

Yang, Xing-Xiao; Ma, Ming; Sang, Mei-Xiang; Zhang, Xue-Yuan; Liu, Zhi-Kun; Song, Heng; Zhu, Shu-Chai

2018-02-01

B-cell‑specific Moloney murine leukaemia virus integration site-1 (BMI-1) contributes to the growth of tumour cells post-irradiation (IR). The aim of the present study was to characterize the effects of BMI-1 on cell viability, radiosensitivity and its mechanisms of action in oesophageal squamous cell cancer (ESCC). Western blotting and immunohistochemistry were employed to evaluate the protein expression of BMI-1 in ESCC cells and specimens, respectively. Additionally, the protein expression levels of BMI-1, H2AK119ub and γH2AX in ESCC cells were detected following different doses of IR and at different times after IR. The protein expression levels of MDC1 and 53BP1 were also measured. Flow cytometry and MTT assays were used to determine cell cycle progression, apoptosis and cell viability. The phosphatidylinositol 3-kinase inhibitor LY294002 and the agonist IGF-1 were employed to suppress or induce the phosphorylation of Akt to determine whether BMI-1 induces radioresistance in ESCC cells via activation of the PI3K/Akt pathway. The expression of BMI-1 was higher in ESCC tissues and cells compared with that in normal oesophageal tissues and cells. In addition, BMI-1 was positively related to tumour size and lymph node metastases and negatively to the overall survival of ESCC patients. IR induced the expression of BMI-1, H2AK119ub and γH2AX in a dose- and time-dependent manner. BMI-1 knockdown lowered the expression of γH2AX, MDC1 and 53BP1, suppressed cell viability and increased radiosensitivity. G2/M phase arrest was eliminated; this was followed by an increased proportion of cells entering the G0/G1 phase after IR and BMI-1 knockdown via the upregulation of P16 and downregulation of cyclin D2 and cyclin-dependent kinase-4. Moreover, BMI-1 knockdown increased cell apoptosis, downregulated MCL-1 and p-Akt and upregulated Bax. Additionally, the inhibitory effect of the downregulation of p-Akt by LY294002 on tumour cell viability was identical to that of BMI-1 knockdown, while the kinase agonist IGF-1 reversed the effects of BMI-1 knockdown on cell viability and radiosensitivity. Taken together, BMI-1 knockdown induces radiosensitivity in ESCC and significantly inhibits cell viability, which may contribute to an increased proportion of cells in the G0/G1 phase and cell apoptosis via suppression of the PI3K/Akt signalling pathway.

Three-dimensional culture of dental pulp stem cells in direct contact to tricalcium silicate cements.

PubMed

Widbiller, M; Lindner, S R; Buchalla, W; Eidt, A; Hiller, K-A; Schmalz, G; Galler, K M

2016-03-01

Calcium silicate cements are biocompatible dental materials applicable in contact with vital tissue. The novel tricalcium silicate cement Biodentine™ offers properties superior to commonly used mineral trioxide aggregate (MTA). Objective of this study was to evaluate its cytocompatibility and ability to induce differentiation and mineralization in three-dimensional cultures of dental pulp stem cells after direct contact with the material. Test materials included a new tricalcium silicate (Biodentine™, Septodont, Saint-Maur-des-Fossés, France), MTA (ProRoot® MTA, DENSPLY Tulsa Dental Specialities, Johnson City, TN, USA), glass ionomer (Ketac™ Molar Aplicap™, 3M ESPE, Seefeld, Germany), human dentin disks and polystyrene. Magnetic activated cell sorting for to the surface antigen STRO-1 was performed to gain a fraction enriched with mesenchymal stem cells. Samples were allowed to set and dental pulp stem cells in collagen carriers were placed on top. Scanning electron microscopy of tricalcium silicate cement surfaces with and without cells was conducted. Cell viability was measured for 14 days by MTT assay. Alkaline phosphatase activity was evaluated (days 3, 7, and 14) and expression of mineralization-associated genes (COL1A1, ALP, DSPP, and RUNX2) was quantified by real-time quantitative PCR. Nonparametric statistical analysis for cell viability and alkaline phosphatase data was performed to compare different materials as well as time points (Mann-Whitney U test, α = 0.05). Cell viability was highest on tricalcium silicate cement, followed by MTA. Viability on glass ionomer cement and dentin disks was significantly lower. Alkaline phosphatase activity was lower in cells on new tricalcium silicate cement compared to MTA, whereas expression patterns of marker genes were alike. Increased cell viability and similar levels of mineralization-associated gene expression in three-dimensional cell cultures on the novel tricalcium silicate cement and mineral trioxide aggregate indicate that the material is cytocompatible and bioactive. The tested new tricalcium silicate cement confirms its suitability as an alternative to MTA in vital pulp therapy.

Antiproliferative effects of cinobufacini on human hepatocellular carcinoma HepG2 cells detected by atomic force microscopy

PubMed Central

Wu, Qing; Lin, Wei-Dong; Liao, Guan-Qun; Zhang, Li-Guo; Wen, Shun-Qian; Lin, Jia-Ying

2015-01-01

AIM: To investigate the antiproliferative activity of cinobufacini on human hepatocellular carcinoma HepG2 cells and the possible mechanism of its action. METHODS: HepG2 cells were treated with different concentrations of cinobufacini. Cell viability was measured by methylthiazolyl tetrazolium (MTT) assay. Cell cycle distribution was analyzed by flow cytometry (FCM). Cytoskeletal and nuclear alterations were observed by fluorescein isothiocyanate-phalloidin and DAPI staining under a laser scanning confocal microscope. Changes in morphology and ultrastructure of cells were detected by atomic force microscopy (AFM) at the nanoscale level. RESULTS: MTT assay indicated that cinobufacini significantly inhibited the viability of HepG2 cells in a dose-dependent manner. With the concentration of cinobufacini increasing from 0 to 0.10 mg/mL, the cell viability decreased from 74.9% ± 2.7% to 49.41% ± 2.2% and 39.24% ± 2.1% (P < 0.05). FCM analysis demonstrated cell cycle arrest at S phase induced by cinobufacini. The immunofluorescence studies of cytoskeletal and nuclear morphology showed that after cinobufacini treatment, the regular reorganization of actin filaments in HepG2 cells become chaotic, while the nuclei were not damaged seriously. Additionally, high-resolution AFM imaging revealed that cell morphology and ultrastructure changed a lot after treatment with cinobufacini. It appeared as significant shrinkage and deep pores in the cell membrane, with larger particles and a rougher cell surface. CONCLUSION: Cinobufacini inhibits the viability of HepG2 cells via cytoskeletal destruction and cell membrane toxicity. PMID:25624718

Impact of lithium alone or in combination with haloperidol on oxidative stress parameters and cell viability in SH-SY5Y cell culture.

PubMed

Gawlik-Kotelnicka, Oliwia; Mielicki, Wojciech; Rabe-Jabłońska, Jolanta; Lazarek, Jerry; Strzelecki, Dominik

2016-02-01

It has been reported that lithium may inhibit lipid peroxidation and protein oxidation. Lithium salts also appear to stimulate cell proliferation, increase neurogenesis, and delay cell death. Oxidative stress and neurodegeneration may play an important role in the pathophysiology of bipolar disorder and the disease course thereof. The aim of this research is to estimate the influence of lithium (alone and in combination with haloperidol) on the parameters of oxidative stress and viability of SH-SY5Y cell lines in neutral and pro-oxidative conditions. The evaluated oxidative stress parameter was lipid peroxidation. The viability of the cell lines was measured utilising the MTT test. In neutral conditions, higher levels of thiobarbituric acid reactive substances were observed in those samples which contained both haloperidol and lithium than in other samples. However, these differences were not statistically significant. Cell viability was significantly higher in therapeutic lithium samples than in the controls; samples of haloperidol alone as well as those of haloperidol with lithium did not differ from controls. The results of our study may indicate that lithium possess neuroprotective properties that may be partly due to antioxidative effects. The combination of lithium and haloperidol may generate increased oxidative stress.

HEMOXCell, a New Oxygen Carrier Usable as an Additive for Mesenchymal Stem Cell Culture in Platelet Lysate-Supplemented Media.

PubMed

Le Pape, Fiona; Cosnuau-Kemmat, Lucie; Richard, Gaëlle; Dubrana, Frédéric; Férec, Claude; Zal, Franck; Leize, Elisabeth; Delépine, Pascal

2017-04-01

Human mesenchymal stem cells (MSCs) are promising candidates for therapeutic applications such as tissue engineering. However, one of the main challenges is to improve oxygen supply to hypoxic areas to reduce oxygen gradient formation while preserving MSC differentiation potential and viability. For this purpose, a marine hemoglobin, HEMOXCell, was evaluated as an oxygen carrier for culturing human bone marrow MSCs in vitro for future three-dimensional culture applications. Impact of HEMOXCell on cell growth and viability was assessed in human platelet lysate (hPL)-supplemented media. Maintenance of MSC features, such as multipotency and expression of MSC specific markers, was further investigated by biochemical assays and flow cytometry analysis. Our experimental results highlight its oxygenator potential and indicate that an optimal concentration of 0.025 g/L HEMOXCell induces a 25%-increase of the cell growth rate, preserves MSC phenotype, and maintains MSC differentiation properties; a two-fold higher concentration induces cell detachment without altering cell viability. Our data suggest the potential interest of HEMOXCell as a natural oxygen carrier for tissue engineering applications to oxygenate hypoxic areas and to maintain cell viability, functions and "stemness." These features will be further tested within three-dimensional scaffolds. © 2017 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

In vitro time- and dose-effect response of JP-8 and S-8 jet fuel on alveolar type II epithelial cells of rats.

PubMed

Robb, Tiffany M; Rogers, Michael J; Woodward, Suann S; Wong, Simon S; Witten, Mark L

2010-07-01

This study was designed to characterize and compare the effects of jet propellant-8 (JP-8) fuel and synthetic-8 (S-8) on cell viability and nitric oxide synthesis in cultured alveolar type II epithelial cells of rats. Exposure times varied from 0.25, 0.5, 1, and 6 hours at the following concentrations of jet fuel: 0.0, 0.1, 0.4, and 2.0 microg/mL. Data indicate that JP-8 presents a gradual decline in cell viability and steady elevation in nitric oxide release as exposure concentrations increase. At a 2.0 microg/mL concentration of JP-8, nearly all of the cells are not viable. Moreover, S-8 exposure to rat type II lung cells demonstrated an abrupt fall in percentage cell viability and increases in nitric oxide measurement, particularly after the 2.0 microg/mL was reached at 1 and 6 hours. At 0.0, 0.2, and 0.4 microg/mL concentrations of S-8, percentage viability was sustained at steady concentrations. The results suggest different epithelial toxicity and mechanistic effects of S-8 and JP-8, providing further insight concerning the impairment imposed at specific levels of lung function and pathology induced by the different fuels.

Comparative studies of cellular viability levels on 2D and 3D in vitro culture matrices.

PubMed

Gargotti, M; Lopez-Gonzalez, U; Byrne, H J; Casey, A

2018-02-01

In this study, the cellular viability and function of immortalized human cervical and dermal cells are monitored and compared in conventional 2D and two commercial 3D membranes, Collagen and Geltrex, of varying working concentration and volume. Viability was monitored with the aid of the Alamar Blue assay, cellular morphology was monitored with confocal microscopy, and cell cycle studies and cell death mechanism studies were performed with flow cytometry. The viability studies showed apparent differences between the 2D and 3D culture systems, the differences attributed in part to the physical transition from 2D to 3D environment causing alterations to effective resazurin concentration, uptake and conversion rates, which was dependent on exposure time, but also due to the effect of the membrane itself on cellular function. These effects were verified by flow cytometry, in which no significant differences in viable cell numbers between 2D and 3D systems were observed after 24 h culture. The results showed the observed effect was different after shorter exposure periods, was also dependent on working concentration of the 3D system and could be mediated by altering the culture vessel size. Cell cycle analysis revealed cellular function could be altered by growth on the 3D substrates and the alterations were noted to be dependent on 3D membrane concentration. The use of 3D culture matrices has been widely interpreted to result in "improved viability levels" or "reduced" toxicity or cellular "resistance" compared to cells cultured on traditional 2D systems. The results of this study show that cellular health and viability levels are not altered by culture in 3D environments, but their normal cycle can be altered as indicated in the cell cycle studies performed and such variations must be accounted for in studies employing 3D membranes for in vitro cellular screening.

Molecular size and origin do not influence the harmful side effects of hydroxyethyl starch on human proximal tubule cells (HK-2) in vitro.

PubMed

Bruno, Raphael R; Neuhaus, Winfried; Roewer, Norbert; Wunder, Christian; Schick, Martin A

2014-09-01

Recently, clinical trials revealed renal impairment induced by hydroxyethyl starch (HES) in septic patients. In prior studies, we managed to demonstrate that HES accumulated in renal proximal tubule cells (PTCs). The related pathomechanism has not yet been discovered. To validate our hypothesis that the HES molecule itself is harmful, regardless of its molecule size or origin, we conducted a comprehensive study to elucidate the influences of different HES preparations on PTC viability in vitro. Cell viability of human PTC was measured with a cytotoxicity assay, quantifying the reduction of tetrazolium salt to colored formazan. Experiments were performed by assessing the influence of different carrier solutions of HES (balanced, nonbalanced, culture medium), different average molecular weights (70, 130, 200 kDa), different origins (potato or corn derived), and various durations of incubation (2-21 hours). Furthermore, HES 130/0.4 was fractionated by ultrafiltration, and the impact on cell viability of average single-size fractions with <3, 3 to 10, 10 to 30, 30 to 50, 50 to 100, and >100 kDa was investigated. We also tested the possible synergistic effects of inflammation induced by tumor necrosis factor-α. All tested HES solutions, regardless of origin or carrier matrix, decreased cell viability in an equivalent, dose-dependent manner. Coincubation with tumor necrosis factor-α did not reduce HES-induced reduction of cell viability. Minor differences were detected comparing 70, 130, and 200 kDa preparations. Analysis of fractionated HES revealed that each fraction decreased cell viability. Even small HES molecules (10-30 kDa) were significantly deleterious. For the first time, we were able to show that only the total mass of HES molecules applied is responsible for the harmful impact on renal PTC in vitro. Neither molecular size nor their origin showed any relevance.

Progress technology in microencapsulation methods for cell therapy.

PubMed

Rabanel, Jean-Michel; Banquy, Xavier; Zouaoui, Hamza; Mokhtar, Mohamed; Hildgen, Patrice

2009-01-01

Cell encapsulation in microcapsules allows the in situ delivery of secreted proteins to treat different pathological conditions. Spherical microcapsules offer optimal surface-to-volume ratio for protein and nutrient diffusion, and thus, cell viability. This technology permits cell survival along with protein secretion activity upon appropriate host stimuli without the deleterious effects of immunosuppressant drugs. Microcapsules can be classified in 3 categories: matrix-core/shell microcapsules, liquid-core/shell microcapsules, and cells-core/shell microcapsules (or conformal coating). Many preparation techniques using natural or synthetic polymers as well as inorganic compounds have been reported. Matrix-core/shell microcapsules in which cells are hydrogel-embedded, exemplified by alginates capsule, is by far the most studied method. Numerous refinement of the technique have been proposed over the years such as better material characterization and purification, improvements in microbead generation methods, and new microbeads coating techniques. Other approaches, based on liquid-core capsules showed improved protein production and increased cell survival. But aside those more traditional techniques, new techniques are emerging in response to shortcomings of existing methods. More recently, direct cell aggregate coating have been proposed to minimize membrane thickness and implants size. Microcapsule performances are largely dictated by the physicochemical properties of the materials and the preparation techniques employed. Despite numerous promising pre-clinical results, at the present time each methods proposed need further improvements before reaching the clinical phase. (c) 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009.

Teratocarcinomas induced by embryonic stem (ES) cells lacking vimentin: an approach to study the role of vimentin in tumorigenesis.

PubMed

Langa, F; Kress, C; Colucci-Guyon, E; Khun, H; Vandormael-Pournin, S; Huerre, M; Babinet, C

2000-10-01

Vimentin is a class III intermediate filament protein widely expressed in the developing embryo and in cells of mesenchymal origin in the adult. Vimentin knock-out mice develop and reproduce without any obvious defect. This is an unexpected finding in view of the high degree of conservation of the vimentin gene among vertebrates. However, it does not exclude the possibility of a role for vimentin in pathological conditions, like tumorigenesis. To address this question directly, we have used a teratocarcinoma model involving the injection of ES cells into syngeneic mice. ES cells lacking vimentin were generated from 129/Sv Vim-/- mice with high efficiency. The absence of vimentin did not affect ES cell morphology, viability or growth rate in vitro. Tumours were induced by subcutaneous injection of either Vim-/- or Vim+/+ ES cells into Vim+/+ and Vim-/- mice, in order to analyse the effect of the absence of vimentin in either the tumorigenic cells or the host mice. No significant differences were found in either tumour incidence, size or vascularization of teratocarcinomas obtained with all possible combinations. Vim-/- ES-derived tumours showed the same cellular composition typical of teratocarcinomas induced by wild-type ES cells together with a very similar apoptotic pattern. Taken together, these results demonstrate that in this model vimentin is not essential for efficient tumour growth and differentiation in vivo.

Low temperature co-fired ceramic packaging of CMOS capacitive sensor chip towards cell viability monitoring.

PubMed

Halonen, Niina; Kilpijärvi, Joni; Sobocinski, Maciej; Datta-Chaudhuri, Timir; Hassinen, Antti; Prakash, Someshekar B; Möller, Peter; Abshire, Pamela; Kellokumpu, Sakari; Lloyd Spetz, Anita

2016-01-01

Cell viability monitoring is an important part of biosafety evaluation for the detection of toxic effects on cells caused by nanomaterials, preferably by label-free, noninvasive, fast, and cost effective methods. These requirements can be met by monitoring cell viability with a capacitance-sensing integrated circuit (IC) microchip. The capacitance provides a measurement of the surface attachment of adherent cells as an indication of their health status. However, the moist, warm, and corrosive biological environment requires reliable packaging of the sensor chip. In this work, a second generation of low temperature co-fired ceramic (LTCC) technology was combined with flip-chip bonding to provide a durable package compatible with cell culture. The LTCC-packaged sensor chip was integrated with a printed circuit board, data acquisition device, and measurement-controlling software. The packaged sensor chip functioned well in the presence of cell medium and cells, with output voltages depending on the medium above the capacitors. Moreover, the manufacturing of microfluidic channels in the LTCC package was demonstrated.

Novel type 1 photosensitizers: viability of leukemia cells exposed to reactive intermediates generated in situ by in vitro photofragmentation

NASA Astrophysics Data System (ADS)

Rajagopalan, Raghavan; Karwa, Amol; Lusiak, Przemyslaw M.; Srivastava, Kripa; Poreddy, Amruta R.; Pandurangi, Raghootama S.; Galen, Karen P.; Neumann, William L.; Cantrell, Gary E.; Dorshow, Richard B.

2009-06-01

Photodynamic therapy of tumors involving Type 2 photosenstizers has been conspicuously successful, but the Type 1 process, in contrast, has not received much attention despite its considerable potential. Accordingly, several classes of molecules containing fragile bonds such as azido (-N=N=N), azo (-N=N-), sulfenato (-S-O-) and oxaza (-N-O-) functional groups that produce reactive intermediates such as radicals and nitrenes upon photoexcitation were prepared and tested for cell viability using U397 leukemia cell line. The azido photosensitizer was conjugated to leukemia cell binding peptide, SFFWRLS, for targeted cell viability study. The cells were incubated with the photosensitizer at various concentrations, and were illuminated for 5, 10, and 20 minutes. The results show that all the photosensitizers caused cell death compared to the controls when exposed to both the photosensitizers and light. Most importantly, selective cell death was observed with the azido peptide conjugate 6, which clearly demonstrates that these Type 1 sensitizers are useful for phototherapeutic applications.

Electroinduced Delivery of Hydrogel Nanoparticles in Colon 26 Cells, Visualized by Confocal Fluorescence System.

PubMed

Atanasova, Severina; Nikolova, Biliana; Murayama, Shuhei; Stoyanova, Elena; Tsoneva, Iana; Zhelev, Zhivko; Aoki, Ichio; Bakalova, Rumiana

2016-09-01

Nano-scale drug delivery systems (nano-DDS) are under intense investigation. Nano-platforms are developed for specific administration of small molecules, drugs, genes, contrast agents [quantum dots (QDs)] both in vivo and in vitro. Electroporation is a biophysical phenomenon which consists of the application of external electrical pulses across the cell membrane. The aim of this study was to research electro-assisted Colon 26 cell line internalization of QDs and QD-loaded nano-hydrogels (polymersomes) visualized by confocal microscopy and their influence on cell viability. The experiments were performed on the Colon 26 cancer cell line, using a confocal fluorescent imaging system and cell viability test. Electroporation facilitated the delivery of nanoparticles in vivo. We demonstrated increased voltage-dependent delivery of nanoparticles into cells after electrotreatment, without significant cell viability reduction. The delivery and retention of the polymersomes in vitro is a promising tool for future cancer treatment strategies and nanomedcine. Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Novel Model for Multispecies Biofilms That Uses Rigid Gas-Permeable Lenses ▿

PubMed Central

Peyyala, Rebecca; Kirakodu, Sreenatha S.; Ebersole, Jeffrey L.; Novak, Karen F.

2011-01-01

Oral biofilms comprise complex multispecies consortia aided by specific inter- and intraspecies interactions occurring among commensals and pathogenic bacterial species. Oral biofilms are primary initiating factors of periodontal disease, although complex multifactorial biological influences, including host cell responses, contribute to the individual outcome of the disease. To provide a system to study initial stages of interaction between oral biofilms and the host cells that contribute to the disease process, we developed a novel in vitro model system to grow biofilms on rigid gas-permeable contact lenses (RGPLs), which enable oxygen to permeate through the lens material. Bacterial species belonging to early- and late-colonizing groups were successfully established as single- or three-species biofilms, with each group comprising Streptococcus gordonii, Streptococcus oralis, and Streptococcus sanguinis; S. gordonii, Actinomyces naeslundii, and Fusobacterium nucleatum; or S. gordonii, F. nucleatum, and Porphyromonas gingivalis. Quantification of biofilm numbers by quantitative PCR (qPCR) revealed substantial differences in the magnitude of bacterial numbers in single-species and multispecies biofilms. We evaluated cell-permeable conventional nucleic acid stains acridine orange, hexidium iodide, and Hoechst 33258 and novel SYTO red, blue, and green fluorochromes for their effect on bacterial viability and fluorescence yield to allow visualization of the aggregates of individual bacterial species by confocal laser scanning microscopy (CLSM). Substantial differences in the quantity and distribution of the species in the multispecies biofilms were identified. The specific features of these biofilms may help us better understand the role of various bacteria in local challenge of oral tissues. PMID:21421785

Mechanistic Aspects of Adenovirus Serotype 2 Inactivation with Free Chlorine ▿ †

PubMed Central

Page, Martin A.; Shisler, Joanna L.; Mariñas, Benito J.

2010-01-01

Free chlorine is an effective disinfectant for controlling adenoviruses in drinking water, but little is known about the underlying inactivation mechanisms. The objective of this study was to elucidate the molecular components of adenovirus type 2 (Ad2) targeted by free chlorine during the inactivation process. The effects of free chlorine treatment on several Ad2 molecular components and associated life cycle events were compared to its effect on the ability of adenovirus to complete its life cycle, i.e., viability. Free chlorine treatment of Ad2 virions did not impair their ability to interact with monoclonal antibodies specific for hexon and fiber proteins of the Ad2 capsid, as measured by enzyme-linked immunosorbent assays, nor did it impair their interaction with recombinant, purified Coxsackie-adenovirus receptor (CAR) proteins in vitro. Free chlorine-treated Ad2 virions also retained their ability to bind to CAR receptors on A549 cell monolayers, despite being unable to form plaques, suggesting that free chlorine inactivates Ad2 by inhibiting a postbinding event of the Ad2 life cycle. DNA isolated from Ad2 virions that had been inactivated by free chlorine was able to be amplified by PCR, indicating that genome damage was not the cause of inactivation. However, inactivated Ad2 virions were unable to express E1A viral proteins during infection of A549 host cells, as measured by using immunoblotting. Collectively, these results indicate that free chlorine inactivates adenovirus by damaging proteins that govern life cycle processes occurring after host cell attachment, such as endocytosis, endosomal lysis, or nuclear delivery. PMID:20305026

In vitro biocorrosion of Ti-6Al-4V implant alloy by a mouse macrophage cell line.

PubMed

Lin, Hsin-Yi; Bumgardner, Joel D

2004-03-15

Corrosion of implant alloys releasing metal ions has the potential to cause adverse tissue reactions and implant failure. We hypothesized that macrophage cells and their released reactive chemical species (RCS) affect the alloy's corrosion properties. A custom cell culture corrosion box was used to evaluate how cell culture medium, macrophage cells and RCS altered the Ti-6Al-4V corrosion behaviors in 72 h and how corrosion products affected the cells. There was no difference in the charge transfer in the presence (75.2 +/- 17.7 mC) and absence (62.3 +/- 18.8 mC) of cells. The alloy had the lowest charge transfer (28.2 +/- 4.1 mC) and metal ion release (Ti < 10 ppb, V < 2 ppb) with activated cells (releasing RCS) compared with the other two conditions. This was attributed to an enhancement of the surface oxides by RCS. Metal ion release was very low (Ti < 20 ppb, V < 10 ppb) with nonactivated cells and did not change cell morphology, viability, and NO and ATP release compared with controls. However, IL-1beta released from the activated cells and the proliferation of nonactivated cells were greater on the alloy than the controls. In summary, macrophage cells and RCS reduced the corrosion of Ti-6Al-4V alloys as hypothesized. These data are important in understanding host tissue-material interactions. Copyright 2004 Wiley Periodicals, Inc. J Biomed Mater Res 68A: 717-724, 2004

Establishment and characterization of a new cell line (SSP-9) derived from Atlantic salmon Salmo salar that expresses type I ifn.

PubMed

Rodriguez Saint-Jean, S; González, C; Monrás, M; Romero, A; Ballesteros, N; Enríquez, R; Perez-Prieto, S

2014-11-01

In the present work, the establishment and biological characterization of a new cell line, SSP-9, derived from the pronephros of the Atlantic salmon Salmo salar, are reported. These cells grew well in Leibovitz's (L15) medium supplemented with 10% foetal calf serum at temperatures from 15 to 25° C, and they have been sub-cultured over 100 passages to produce a continuous cell line with an epithelial-like morphology. The SSP-9 cells attached and spread efficiently at different plating densities, retaining 80% of cell viability after storage in liquid nitrogen. When karyotyped, the cells had 40-52 chromosomes, with a modal number of 48. Viral susceptibility tests showed that SSP-9 cells were susceptible to infectious pancreatic necrosis virus and infectious haematopoietic necrosis virus, producing infectious virus and regular cytopathic effects. Moreover, these cells could be stimulated by poly I:C, showing significant up-regulation in the expression of the genes that regulate immune responses, such as ifn and mx-1. SSP-9 cells constitutively express genes characteristic of macrophages, such as major histocompatibility complex (mhc-II) and interleukin 12b (il-12b), and flow cytometry assays confirmed that SSP-9 cells can be permanently transfected with plasmids expressing a reporter gene. Accordingly, this new cell line is apparently suitable for transgenic manipulation, and to study host cell-virus interactions and immune processes. © 2014 The Fisheries Society of the British Isles.

In Vitro Effects of Preserved and Unpreserved Anti-Allergic Drugs on Human Corneal Epithelial Cells

PubMed Central

Calvo, Patricia; Ropero, Inés; Pintor, Jesús

2014-01-01

Abstract Purpose: Treatment with topical eye drops for long-standing ocular diseases like allergy can induce detrimental side effects. The purpose of this study was to investigate in vitro cytotoxicity of commercially preserved and unpreserved anti-allergic eye drops on the viability and barrier function of monolayer and stratified human corneal-limbal epithelial cells. Methods: Cells were treated with unpreserved ketotifen solution, benzalkonium chloride (BAC)-containing anti-allergic drugs (ketotifen, olopatadine, levocabastine) as well as BAC alone. 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay was used to determine cell viability. Effects of compounds on barrier function were analyzed measuring transepithelial electrical resistance (TEER) to determine paracellular permeability and rose bengal assays to evaluate transcellular barrier formation. Results: The BAC-preserved anti-allergic formulations and BAC alone significantly reduced cell viability, monolayer cultures being more sensitive to damage by these solutions. Unpreserved ketotifen induced the least diminution in cell viability. The extent of decrease of cell viability was clearly dependent of BAC presence, but it was also affected by the different types of drugs when the concentration of BAC was low and the short time of exposure. Treatment with BAC-containing anti-allergic drugs and BAC alone resulted in increased paracellular permeability and loss of transcellular barrier function as indicated by TEER measurement and rose bengal assays. Conclusions: The presence of the preservative BAC in anti-allergic eye drop formulations contributes importantly to the cytotoxic effects induced by these compounds. Stratified cell cultures seem to be a more relevant model for toxicity evaluation induced on the ocular surface epithelia than monolayer cultures. PMID:25100331

A MULTIPLEXED ASSAY FOR DETERMINATION OF NEUROTOXICANT EFFECTS ON SPONTANEOUS NETWORK ACTIVITY AND CELL VIABILITY FROM MICROELECTRODE ARRAYS

EPA Science Inventory

AbstractTITLE: A MULTIPLEXED ASSAY FOR DETERMINATION OF NEUROTOXICANT EFFECTS ON SPONTANEOUS NETWORK ACTIVITY AND CELL VIABILITY FROM MICROELECTRODE ARRAYSABSTRACT BODY: Microelectrode array (MEA) recordings are increasingly being used as an in vitro method to detect and characte...

Encapsulation of a rhodamine dye within a bile acid binding protein: toward water processable functional bio host-guest materials.

PubMed

Tomaselli, Simona; Giovanella, Umberto; Pagano, Katiuscia; Leone, Giuseppe; Zanzoni, Serena; Assfalg, Michael; Meinardi, Francesco; Molinari, Henriette; Botta, Chiara; Ragona, Laura

2013-10-14

New strategies are requested for the preparation of bioinspired host-guest complexes to be employed in technologically relevant applications, as sensors and optoelectronic devices. We report here a new approach employing a single monomeric protein as host for the strongly fluorescent rhodamine dye. The selected protein, belonging to the intracellular lipid binding protein family, fully encapsulates one rhodamine molecule inside its cavity forming a host-guest complex stabilized by H and π-hydrogen bonds, a salt bridge, and favorable hydrophobic contacts, as revealed by the NMR derived structural model. The protein-dye solutions are easily processable and form homogeneous thin films exhibiting excellent photophysical and morphological properties, as derived from photoluminescence and AFM data. The obtained results represent the proof of concept of the viability of this bio host-guest system for the development of bioinspired optoelectronic devices.

Plant quality and local adaptation undermine relocation in a bog specialist butterfly

PubMed Central

Turlure, Camille; Radchuk, Viktoriia; Baguette, Michel; Meijrink, Mark; den Burg, Arnold; Vries, Michiel Wallis; Duinen, Gert-Jan

2013-01-01

The butterfly Boloria aquilonaris is a specialist of oligotrophic ecosystems. Population viability analysis predicted the species to be stable in Belgium and to collapse in the Netherlands with reduced host plant quality expected to drive species decline in the latter. We tested this hypothesis by rearing B. aquilonaris caterpillars from Belgian and Dutch sites on host plants (the cranberry, Vaccinium oxycoccos). Dutch plant quality was lower than Belgian one conferring lower caterpillar growth rate and survival. Reintroduction and/or supplementation may be necessary to ensure the viability of the species in the Netherlands, but some traits may have been selected solely in Dutch caterpillars to cope with gradual changes in host plant quality. To test this hypothesis, the performance of Belgian and Dutch caterpillars fed with plants from both countries were compared. Dutch caterpillars performed well on both plant qualities, whereas Belgian caterpillars could not switch to lower quality plants. This can be considered as an environmentally induced plastic response of caterpillars and/or a local adaptation to plant quality, which precludes the use of Belgian individuals as a unique solution for strengthening Dutch populations. More generally, these results stress that the relevance of local adaptation in selecting source populations for relocation may be as important as restoring habitat quality. PMID:23467336

Osteoarticular cells tolerate short-term exposure to nitisinone-implications in alkaptonuria.

PubMed

Mistry, J B; Jackson, D J; Bukhari, M; Taylor, A M

2016-02-01

Alkaptonuria (AKU) is a rare genetic disease resulting in severe, rapidly progressing, early onset multi-joint osteoarthropathy. A potential therapy, nitisinone, is being trialled that reduces the causative agent; homogentisic acid (HGA) and in a murine model has shown to prevent ochronosis. Little is currently known about the effect nitisinone has on osteoarticular cells; these cells suffer most from the presence of HGA and its polymeric derivatives. This led us to investigate nitisinone's effect on chondrocytes and osteoblast-like cells in an in vitro model. Human C20/A4 immortalized chondrocytes, and osteosarcoma cells MG63 cultured in DMEM, as previously described. Confluent cells were then plated into 24-well plates at 4 × 10(4) cells per well in varying concentrations of nitisinone. Cells were cultured for 7 days with medium changes every third day. Trypan blue assay was used to determine viability and the effect of nitisinone concentration on cells. Statistical analysis was performed using analysis of variance, and differences between groups were determined by Newman-Keuls post-test. Analysis of C20/A4 chondrocyte and MG63 osteoblast-like cell viability when cultured in different concentrations of nitisinone demonstrates that there is no statistically significant difference in cell viability compared to control cultures. There is currently no literature surrounding the use of nitisinone in human in vitro models, or its effect on chondrocytes or osteoblast like cells. Our results show that nitisinone does not appear detrimental to cell viability of chondrocytes or osteoblast-like cells, which adds to the evidence that this therapy could be useful in treating AKU.

The effect of uranium on bacterial viability and cell surface morphology using atomic force microscopy in the presence of bicarbonate ions.

PubMed

Sepulveda-Medina, Paola; Katsenovich, Yelena; Musaramthota, Vishal; Lee, Michelle; Lee, Brady; Dua, Rupak; Lagos, Leonel

2015-06-01

Past disposal practices at nuclear production facilities have led to the release of liquid waste into the environment creating multiple radionuclide plumes. Microorganisms are known for the ability to interact with radionuclides and impact their mobility in soils and sediments. Gram-positive Arthrobacter sp. are one of the most common bacterial groups in soils and are found in large numbers in subsurface environments contaminated with radionuclides. This study experimentally analyzed changes on the bacteria surface at the nanoscale level after uranium exposure and evaluated the effect of aqueous bicarbonate ions on U(VI) toxicity of a low uranium-tolerant Arthrobacter oxydans strain G968 by investigating changes in adhesion forces and cell dimensions via atomic force microscopy (AFM). Experiments were extended to assess cell viability by the Live/Dead BacLight Bacterial Viability Kit (Molecular Probes) and quantitatively illustrate the effect of uranium exposure in the presence of varying concentrations of bicarbonate ions. AFM and viability studies showed that samples containing bicarbonate were able to withstand uranium toxicity and remained viable. Samples containing no bicarbonate exhibited deformed surfaces and a low height profile, which, in conjunction with viability studies, indicated that the cells were not viable. Copyright © 2015 Institut Pasteur. All rights reserved.

Fibroblast Viability after Storage at 20 °C in Milk, Hank's Balanced Salt Solution and Coconut Water.

PubMed

Souza, Beatriz Dulcineia Mendes de; Alves, Ana Maria Hecke; Santos, Luciane Geanini Pena Dos; Simões, Claudia Maria de Oliveira; Felippe, Wilson Tadeu; Felippe, Mara Cristina Santos

2016-01-01

The objective of this study was to evaluate the effectiveness of various storage media at 20 °C in maintaining the viability of human periodontal ligament fibroblasts (HPLF) over time. HPLF were maintained at 20 °C in skim milk (SM), whole milk (WM), freshly prepared Hank's balanced salt solution (HBSS), Save-A-Tooth(r), natural coconut water (NCW), coconut water industrialized (ICW) and tap water (negative control) for 3, 6, 24, 48, 72, 96 and 120 h. Cells maintained in Minimal Essential Medium (MEM-37) at 37 °C served as a positive control. Cell viability was determined by MTT assay. Statistical analysis was performed by Kruskal-Wallis test and Scheffe test (α = 5%). From 24 h, NCW was significantly better in maintaining cell viability than all other tested storage media (p<0.05). SM and WM were significantly better than HBSS for up to 72 h. Save-A-Tooth(r) and ICW were the worst conservation storage media. In conclusion, the effectiveness of the tested storage media to maintain the viability of the periodontal ligament cells was as follows, in a descending order: NCW > MEM-37> SM and IM> HBSS> ICW > Save-A-Tooth(r)> tap water.

The active transport of histidine and its role in ATP production in Trypanosoma cruzi.

PubMed

Barisón, M J; Damasceno, F S; Mantilla, B S; Silber, A M

2016-08-01

Trypanosoma cruzi, the aetiological agent of Chagas's disease, metabolizes glucose, and after its exhaustion, degrades amino acids as energy source. Here, we investigate histidine uptake and its participation in energy metabolism. No putative genes for the histidine biosynthetic pathway have been identified in genome databases of T. cruzi, suggesting that its uptake from extracellular medium is a requirement for the viability of the parasite. From this assumption, we characterized the uptake of histidine in T. cruzi, showing that this amino acid is incorporated through a single and saturable active system. We also show that histidine can be completely oxidised to CO2. This finding, together with the fact that genes encoding the putative enzymes for the histidine - glutamate degradation pathway were annotated, led us to infer its participation in the energy metabolism of the parasite. Here, we show that His is capable of restoring cell viability after long-term starvation. We confirm that as an energy source, His provides electrons to the electron transport chain, maintaining mitochondrial inner membrane potential and O2 consumption in a very efficient manner. Additionally, ATP biosynthesis from oxidative phosphorylation was found when His was the only oxidisable metabolite present, showing that this amino acid is involved in bioenergetics and parasite persistence within its invertebrate host.

Propofol protects hippocampal neurons from apoptosis in ischemic brain injury by increasing GLT-1 expression and inhibiting the activation of NMDAR via the JNK/Akt signaling pathway.

PubMed

Gong, Hong-Yan; Zheng, Fang; Zhang, Chao; Chen, Xi-Yan; Liu, Jing-Jing; Yue, Xiu-Qin

2016-09-01

Ischemic brain injury (IBI) can cause nerve injury and is a leading cause of morbidity and mortality worldwide. The neuroprotective effects of propofol against IBI have been previously demonstrated. However, the neuroprotective effects of propofol on hippocampal neurons are not yet entirely clear. In the present study, models of IBI were established in hypoxia-exposed hippocampal neuronal cells. Cell viability assay and apoptosis assay were performed to examine the neuroprotective effects of propofol on hippocampal neurons in IBI. A significant decrease in cell viability and a significant increase in cell apoptosis were observed in the IBI group compared with the control group, accompanied by a decrease in glial glutamate transporter-1 (GLT‑1) expression as determined by RT-qPCR and western blot analysis. The effects of IBI were reversed by propofol treatment. The siRNA-mediated knockdown of GLT‑1 in the hypoxia-exposed hippocampal neuronal cells led to an increase in cell apoptosis, Jun N-terminal kinase (JNK) activation and N-methyl-D‑aspartate (NMDA) receptor (NR1 and NR2B) activation, as well as to a decrease in cell viability and a decrease in Akt activation. The effects of RNA interference-mediated GLT‑1 gene silencing on cell viability, JNK activation, NMDAR activation, cell apoptosis and Akt activation in the hippocampal neuronal cells were slightly reversed by propofol treatment. The JNK agonist, anisomycin, and the Akt inhibitor, LY294002, both significantly blocked the effects of propofol on hippocampal neuronal cell viability and apoptosis in IBI. The decrease in JNK activation and the increase in Akt activation caused by GLT‑1 overexpression were reversed by NMDA. Collectively, our findings suggest that propofol treatment protects hippocampal neurons against IBI by enhancing GLT‑1 expression and inhibiting the activation of NMDAR via the JNK/Akt signaling pathway.

Morphology, cell viability, karyotype, expression of surface markers and plasticity of three human primary cell line cultures before and after the cryostorage in LN2 and GN2.

PubMed

Del Pino, Alberto; Ligero, Gertrudis; López, María B; Navarro, Héctor; Carrillo, Jose A; Pantoll, Siobhan C; Díaz de la Guardia, Rafael

2015-02-01

Primary cell line cultures from human skin biopsies, adipose tissue and tumor tissue are valuable samples for research and therapy. In this regard, their derivation, culture, storage, transport and thawing are important steps to be studied. Towards this end, we wanted to establish the derivation, and identify the culture characteristics and the loss of viability of three human primary cell line cultures (human adult dermal fibroblasts (hADFs), human adult mesenchymal stem cells (hMSCs), and primary culture of tumor cells from lung adenocarcinoma (PCTCLA)). Compared to fresh hADFs, hMSCs and PCTCLA, thawed cells stored in a cryogenic Dewar tanks with liquid nitrogen (LN2), displayed 98.20% ± 0.99, 95.40% ± 1.41 and 93.31% ± 3.83 of cell viability, respectively. Thawed cells stored in a Dry Vapor Shipper container with gas phase (GN2), for 20 days, in addition displayed 4.61% ± 2.78, 3.70% ± 4.09 and 9.13% ± 3.51 of average loss of cells viability, respectively, showing strong correlation between the loss of viability in hADFs and the number of post-freezing days in the Dry Vapor Shipper. No significant changes in morphological characteristics or in the expression of surface markers (being hADFs, hMSCs and PCTCLA characterized by positive markers CD73+; CD90+; CD105+; and negative markers CD14-; CD20-; CD34-; and CD45-; n=2) were found. Chromosome abnormalities in the karyotype were not found. In addition, under the right conditions hMSCs were differentiated into adipogenic, osteogenic and chondrogenic lineages in vitro. In this paper, we have shown the characteristics of three human primary cell line cultures when they are stored in LN2 and GN2. Copyright © 2014 Elsevier Inc. All rights reserved.

Alternative therapeutic approach to renal-cell carcinoma: induction of apoptosis with combination of vitamin K3 and D-fraction.

PubMed

Degen, Michael; Alexander, Bobby; Choudhury, Muhammad; Eshghi, Majid; Konno, Sensuke

2013-12-01

Because of a dismal prognosis for advanced renal-cell carcinoma (RCC), an alternative therapeutic approach, using vitamin K3 (VK3) and D-fraction (DF) was investigated. VK3 is a synthetic VK derivative and DF is a bioactive mushroom extract, and they have been shown to have antitumor activity. We examined if the combination of VK3 and DF would exhibit the improved anticancer effect on RCC in vitro. Human RCC, ACHN cell line, were treated with varying concentrations of VK3, DF, or a combination of the two. Cell viability was assessed at 72 hours by MTT assay. To explore the possible anticancer mechanism, studies on cell cycle, chromatin modifications, and apoptosis were conducted. VK3 alone led to a ~20% reduction in cell viability at 4 μM, while DF alone induced a 20% to 45% viability reduction at ≥ 500 μg/mL. A combination of VK3 (4 μM) and DF (300 μg/mL) led to a drastic >90% viability reduction, however. Cell cycle analysis indicated that VK3/DF treatment induced a G1 cell cycle arrest, accompanied by the up-regulation of p21(WAF1) and p27(Kip1). Histone deacetylase (HDAC) was also significantly (~60%) inactivated, indicating chromatin modifications. In addition, Western blot analysis revealed that the up-regulation of Bax and activation of poly-(ADP-ribose)-polymerase (PARP) were seen in VK3/DF-treated cells, indicating induction of apoptosis. The combination of VK3 and DF can lead to a profound reduction in ACHN cell viability, through a p21(WAF1)-mediated G1 cell cycle arrest, and ultimately induces apoptosis. Therefore, the combination of VK3/DF may have clinical implications as an alternative, improved therapeutic modality for advanced RCC.

Long Noncoding RNA H19 Inhibits Cell Viability, Migration, and Invasion Via Downregulation of IRS-1 in Thyroid Cancer Cells

PubMed Central

Wang, Peng; Xu, Weimin; Liu, Haixia; Bu, Qingao; Sun, Diwen

2017-01-01

Thyroid cancer is a common endocrine gland malignancy which exhibited rapid increased incidence worldwide in recent decades. This study was aimed to investigate the role of long noncoding RNA H19 in thyroid cancer. Long noncoding RNA H19 was overexpressed or knockdown in thyroid cancer cells SW579 and TPC-1, and the expression of long noncoding RNA H19 was detected by real-time polymerase chain reaction. The cell viability, migration, and invasion were determined by 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide assay, Transwell assay, and wound healing assay, respectively. Furthermore, cell apoptosis was analyzed by flow cytometry, and expressions of some factors that were related to phosphatidyl inositide 3-kinases/protein kinase B and nuclear factor κB signal pathway were measured by Western blotting. This study revealed that cell viability and migration/invasion of SW579 and TPC-1 were significantly decreased by long noncoding RNA H19 overexpression compared with the control group (P < .05), whereas cell apoptosis was statistically increased (P < .001). Meanwhile, cell viability and migration/invasion were significantly increased after long noncoding RNA H19 knockdown (P < .05). Furthermore, long noncoding RNA H19 negatively regulated the expression of insulin receptor substrate 1 and thus effect on cell proliferation and apoptosis. Insulin receptor substrate 1 regulated the activation of phosphatidyl inositide 3-kinases/AKT and nuclear factor κB signal pathways. In conclusion, long noncoding RNA H19 could suppress cell viability, migration, and invasion via downregulation of insulin receptor substrate 1 in SW579 and TPC-1 cells. These results suggested the important role of long noncoding RNA H19 in thyroid cancer, and long noncoding RNA H19 might be a potential target of thyroid cancer treatment. PMID:29332545

In Vitro Model for Predicting the Protective Effect of Ultraviolet-Blocking Contact Lens in Human Corneal Epithelial Cells.

PubMed

Abengózar-Vela, Antonio; Arroyo, Cristina; Reinoso, Roberto; Enríquez-de-Salamanca, Amalia; Corell, Alfredo; González-García, María Jesús

2015-01-01

To develop an in vitro method to determine the protective effect of UV-blocking contact lenses (CLs) in human corneal epithelial (HCE) cells exposed to UV-B radiation. SV-40-transformed HCE cells were covered with non-UV-blocking CL, UV-blocking CL or not covered, and exposed to UV-B radiation. As control, HCE cells were covered with both types of CLs or not covered, but not exposed to UV-B radiation. Cell viability at 24, 48 and 72 h, after UV-B exposure and removing CLs, was determined by alamarBlue(®) assay. Percentage of live, dead and apoptotic cells was also assessed by flow cytometry after 24 h of UV-B exposure. Intracellular reactive oxygen species (ROS) production after 1 h of exposure was assessed using the dye H(2)DCF-DA. Cell viability significantly decreased, apoptotic cells and intracellular ROS production significantly increased when UVB-exposed cells were covered with non-UV-blocking CL or not covered compared to non-irradiated cells. When cells were covered with UV-blocking CL, cell viability significantly increased and apoptotic cells and intracellular ROS production did not increase compared to exposed cells. UV-B radiation induces cell death by apoptosis, increases ROS production and decreases viable cells. UV-blocking CL is able to avoid these effects increasing cell viability and protecting HCE cells from apoptosis and ROS production induced by UV-B radiation. This in vitro model is an alternative to in vivo methods to determine the protective effect of UV-blocking ophthalmic biomaterials because it is a quicker, cheaper and reliable model that avoids the use of animals.

Pravastatin and simvastatin inhibit the adhesion, replication and proliferation of Toxoplasma gondii (RH strain) in HeLa cells.

PubMed

Sanfelice, Raquel Arruda; da Silva, Suelen Santos; Bosqui, Larissa Rodrigues; Miranda-Sapla, Milena Menegazzo; Barbosa, Bellisa Freitas; Silva, Rafaela José; Ferro, Eloísa A Vieira; Panagio, Luciano Aparecido; Navarro, Italmar Teodorico; Bordignon, Juliano; Conchon-Costa, Ivete; Pavanelli, Wander Rogerio; Almeida, Ricardo Sergio; Costa, Idessania Nazareth

2017-03-01

The conventional treatment for toxoplasmosis with pyrimethamine and sulfadiazine shows toxic effects to the host, and it is therefore necessary to search for new drugs. Some studies suggest the use of statins, which inhibit cholesterol synthesis in humans and also the initial processes of isoprenoid biosynthesis in the parasite. Thus, the objective of this study was to evaluate the activity of the statins pravastatin and simvastatin in HeLa cells infected in vitro with the RH strain of T. gondii. HeLa cells (1×10 5 ) were infected with T. gondii tachyzoites (5×10 5 ) following two different treatment protocols. In the first protocol, T. gondii tachyzoites were pretreated with pravastatin (50 and 100μg/mL) and simvastatin (1.56 and 3.125μg/mL) for 30min prior to infection. In the second, HeLa cells were first infected (5×10 5 ) with tachyzoites and subsequently treated with pravastatin and simvastatin for 24h at the concentrations noted above. Initially, we evaluated the cytotoxicity of drugs by the MTT assay, number of tachyzoites adhered to cells, number of infected cells, and viability of tachyzoites by trypan blue exclusion. The supernatant of the cell cultures was collected post-treatment for determination of the pattern of Th1/Th2/Th17 cytokines by cytometric bead array. There was no cytotoxicity to HeLa cells with 50 and 100μg/mL pravastatin and 1.56 and 3.125μg/mL simvastatin. There was no change in the viability of tachyzoites that received pretreatment. Regarding the pre- and post-treatment of the cells with pravastatin and simvastatin alone, there was a reduction in adhesion, invasion and proliferation of cells to T. gondii. As for the production of cytokines, we found that IL-6 and IL-17 were significantly reduced in cells infected with T. gondii and treated with pravastatin and simvastatin, when compared to control. Based on these results, we can infer that pravastatin and simvastatin alone possess antiproliferative effects on tachyzoites forms of T. gondii, giving these drugs new therapeutic uses. Copyright © 2016 Elsevier B.V. All rights reserved.

Long noncoding RNA SNHG1 promotes non-small cell lung cancer progression by up-regulating MTDH via sponging miR-145-5p.

PubMed

Lu, Qingchun; Shan, Shan; Li, Yanyan; Zhu, Dongyi; Jin, Wenjing; Ren, Tao

2018-02-21

Long noncoding RNAs participate in the progression and initiation of non-small cell lung cancer (NSCLC), although the mechanism remains unknown. The lncRNA identified as small nucleolar RNA host gene 1 ( SNHG1) is a novel lncRNA that is increased in multiple human cancers; however, the regulatory mechanism requires further investigation. In this study, we discovered that SNHG1 was markedly up-regulated in NSCLC tissues and cells and that SNHG1 silencing decreased tumor volumes. Moreover, we explored its regulatory mechanism and found that SNHG1 directly bound to microRNA (miRNA)-145-5p, isolating miR-145-5p from its target gene MTDH. Inhibition of SNHG1 suppressed NSCLC cell viability, proliferation, migration, and invasion in vitro, but its effect was rescued by miR-145-5p inhibition. These results demonstrate that SNHG1 contributes to NSCLC progression by modulating the miR-145-5p/ MTDH axis, and it could potentially be a therapeutic target as well as a diagnostic marker.-Lu, Q., Shan, S., Li, Y., Zhu, D., Jin, W., Ren, T. Long noncoding RNA SNHG1 promotes non-small cell lung cancer progression by up-regulating MTDH via sponging miR-145-5p.

Effects of ozone exposure on human epithelial adenocarcinoma and normal fibroblasts cells

PubMed Central

Colafarina, Sabrina; Aruffo, Eleonora; Zarivi, Osvaldo; Bonfigli, Antonella; Di Bucchianico, Sebastiano; Di Carlo, Piero

2017-01-01

Previous studies show variable ozone cytotoxicity and genotoxicity in cell cultures, laboratory animals and humans directly exposed to tropospheric ozone. The aim of this study was therefore to investigate and compare the cyto and genotoxic effects of ozone using adenocarcinoma human alveolar basal epithelial cells A549 and normal human fibroblasts Hs27. A cell culture chamber with controlled atmosphere (a simulation reactor) was built to inject a flow of 120 ppb of ozone, which is two times the threshold value for the protection of human health, fixed by the EU legislation. Cell proliferation was evaluated by a luminescent cell viability assay while we assessed the genotoxic potential of ozone by the induction of micronuclei as well as evaluating DNA strand breaks by the induction of micronuclei evaluated by means of the cytokinesis-block micronucleus (CBMN) assay as well as evaluating DNA strand breaks by Alkaline Comet Assay (CA) or Comet Assay. A549 cells viability decreases significantly at 24 hours treatment with 120 ppb of O3 while at 48 hours and 72 hours O3 treated cells viability doesn’t differ in respect to the control. However a significative decrease of A549 viability is shown at 72 hours vs. 48 hours in both treated and not-treated cells. The viability trend in the Hs27 cells did not show any significant changes in treated samples compared to the control in all conditions. The two genotoxicity biomarkers, the micronucleus and the comet tests, showed in both the cell types exposed to ozone, a significant increase in the number of micronuclei and in the tail DNA % in respect to the control even if at different times/cell type. Moreover, we found that O3 provokes genotoxic effects more evident in A549 cancer cells than in normal fibroblasts Hs27 ones. We applied a cell growth simulation model referred to ozone treated or not cell lines to confirm that the ozone exposure causes a slackening in the cells replication. PMID:28886142

The expression and role of serotonin receptor 5HTR2A in canine osteoblasts and an osteosarcoma cell line.

PubMed

Bracha, Shay; Viall, Austin; Goodall, Cheri; Stang, Bernadette; Ruaux, Craig; Seguin, Bernard; Chappell, Patrick E

2013-12-12

The significance of the serotonergic system in bone physiology and, more specifically, the importance of the five hydroxytryptamine receptor 2A (5HTR2A) in normal osteoblast proliferation have been previously described; however the role of serotonin in osteosarcoma remains unclear. Particularly, the expression and function of 5HTR2A in canine osteosarcoma has not yet been studied, thus we sought to determine if this indoleamine modulates cellular proliferation in vitro. Using real time quantitative reverse transcription PCR and immunoblot analyses, we explored receptor expression and signaling differences between non-neoplastic canine osteoblasts (CnOb) and an osteosarcoma cell line (COS). To elucidate specific serotonergic signaling pathways triggered by 5HTR2A, we performed immunoblots for ERK and CREB. Finally, we compared cell viability and the induction of apoptosis in the presence 5HTR2A agonists and antagonists. 5HTR2A was overexpressed in the malignant cell line in comparison to normal cells. In CnOb cells, ERK phosphorylation (ERK-P) decreased in response to both serotonin and a specific 5HTR2A antagonist, ritanserin. In contrast, ERK-P abundance increased in COS cells following either treatment. While endogenous CREB was undetectable in CnOb, CREB was observed constitutively in COS, with expression and exhibited increased CREB phosphorylation following escalating concentrations of ritanserin. To determine the influence of 5HTR2A signaling on cell viability we challenged cells with ritanserin and serotonin. Our findings confirmed that serotonin treatment promoted cell viability in malignant cells but not in normal osteoblasts. Conversely, ritanserin reduced cell viability in both the normal and osteosarcoma cells. Further, ritanserin induced apoptosis in COS at the same concentrations associated with decreased cell viability. These findings confirm the existence of a functional 5HTR2A in a canine osteosarcoma cell line. Results indicate that intracellular second messenger signal coupling of 5HTR2A is different between normal and malignant cells, warranting further research to investigate its potential as a novel therapeutic target for canine osteosarcoma.

Flow cytometric assay for analysis of cytotoxic effects of potential drugs on human peripheral blood leukocytes

NASA Astrophysics Data System (ADS)

Nieschke, Kathleen; Mittag, Anja; Golab, Karolina; Bocsi, Jozsef; Pierzchalski, Arkadiusz; Kamysz, Wojciech; Tarnok, Attila

2014-03-01

Toxicity test of new chemicals belongs to the first steps in the drug screening, using different cultured cell lines. However, primary human cells represent the human organism better than cultured tumor derived cell lines. We developed a very gentle toxicity assay for isolation and incubation of human peripheral blood leukocytes (PBL) and tested it using different bioactive oligopeptides (OP). Effects of different PBL isolation methods (red blood cell lysis; Histopaque isolation among others), different incubation tubes (e.g. FACS tubes), anticoagulants and blood sources on PBL viability were tested using propidium iodide-exclusion as viability measure (incubation time: 60 min, 36°C) and flow cytometry. Toxicity concentration and time-depended effects (10-60 min, 36 °C, 0-100 μg /ml of OP) on human PBL were analyzed. Erythrocyte lysis by hypotonic shock (dH2O) was the fastest PBL isolation method with highest viability (>85%) compared to NH4Cl-Lysis (49%). Density gradient centrifugation led to neutrophil granulocyte cell loss. Heparin anticoagulation resulted in higher viability than EDTA. Conical 1.5 mL and 2 mL micro-reaction tubes (both polypropylene (PP)) had the highest viability (99% and 97%) compared to other tubes, i.e. three types of 5.0 mL round-bottom tubes PP (opaque-60%), PP (blue-62%), Polystyrene (PS-64%). Viability of PBL did not differ between venous and capillary blood. A gentle reproducible preparation and analytical toxicity-assay for human PBL was developed and evaluated. Using our assay toxicity, time-course, dose-dependence and aggregate formation by OP could be clearly differentiated and quantified. This novel assay enables for rapid and cost effective multiparametric toxicological screening and pharmacological testing on primary human PBL and can be adapted to high-throughput-screening.°z

Viability and biomass of Micrococcus luteus DE2008 at different salinity concentrations determined by specific fluorochromes and CLSM-image analysis.

PubMed

Puyen, Zully M; Villagrasa, Eduard; Maldonado, Juan; Esteve, Isabel; Solé, Antonio

2012-01-01

In previous studies, our group developed a method based on Confocal Laser Scanning Microscopy and Image Analysis (CLSM-IA) to analyze the diversity and biomass of cyanobacteria in microbial mats. However, this method cannot be applied to heterotrophic microorganisms, as these do not have autofluorescence. In this article, we present a method that combines CLSM-IA and Hoechst 33342 and SYTOX Green fluorochromes (FLU-CLSM-IA) to determine the viability and biomass of Micrococcus luteus DE2008, isolated from a saline microbial mat (Ebro Delta, Tarragona, Spain). The method has been applied to assess the effect of salinity on this microorganism. A reduction in viability and biomass (live cells) was observed as the salt concentration increases. The largest effect was at 100‰ NaCl with a cell death of 27.25% and a decrease in total and individual biomass of 39.75 and 0.009 mgC/cm(3), respectively, both with respect to optimal growth (10 ‰ NaCl). On the other hand, another important contribution of this article was that combining the FLU-CLSM-IA results with those achieved by plate counts enabled us to determine, for first time, the viability and the total biomass of the "dormant cells" (66.75% of viability and 40.59 mgC/cm(3) of total biomass at 100‰ NaCl). FLU-CLSM-IA is an efficient, fast, and reliable method for making a total count of cells at pixel level, including the dormant cells, to evaluate the viability and the biomass of a hetetrophic microorganism, M. luteus DE2008.

Novel in vivo flow cytometry platform for early prognosis of metastatic activity of circulating tumor cells (Conference Presentation)

NASA Astrophysics Data System (ADS)

Nolan, Jacqueline; Cai, Chenzhoung; Nedosekin, Dmitry A.; Zharov, Vladimir P.

2017-02-01

Approximately 8 million people lose their lives due to cancer each year. Metastatic disease is responsible for 90% of those cancer-related deaths. Only viable circulating tumor cells (CTCs) that can survive in the blood circulation can create secondary tumors. Thus, real-time enumeration of CTCs and assessment of their viability in vivo has great biological significance. However, little progress has been made in this field. Conventional flow cytometry is the current technique being used for the assessment of cell viability, but there are many limitations to this technique: 1) cell properties may be altered during the extraction and processing method; 2) collection of cells from blood prevents the long-term study of individual cells in their natural biological environment; and 3) there are time-consuming preparation procedures. Whether it be for the assessment of antitumor drugs, where induction of apoptosis or necrosis is the preferred event, or the identification of nanoparticle-induced toxicity during nanotherapeutic treatment, it is clear that new approaches for assessment of the viability circulating blood cells and CTCs are urgently needed. We have developed a novel high speed, multicolor in vivo flow cytometry (FC) platform that integrates photoacoustic (PA) and fluorescence FC (PAFFC) and demonstrate its ability to enumerate rare circulating normal and abnormal (e.g. tumor) cells and assess their viability (e.g. apoptotic and necrotic) in a mouse model.

Effects of nicotine in the presence and absence of vitamin E on morphology, viability and osteogenic gene expression in MG-63 osteoblast-like cells.

PubMed

Torshabi, Maryam; Esfahrood, Zeinab Rezaei; Gholamin, Parisan; Karami, Elahe

2016-11-01

Evidence shows that oxidative stress induced by nicotine plays an important role in bone loss. Vitamin E with its antioxidative properties may be able to reverse the effects of nicotine on bone. This study aimed to assess the effects of nicotine in the presence and absence of vitamin E on morphology, viability and osteogenic gene expression in MG-63 (osteosarcoma) human osteoblast-like cells. We treated the cells with 5 mM nicotine. The viability and morphology of cells were evaluated respectively using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium (MTT) and crystal violet assays. The effect of nicotine on osteogenic gene expression in MG-63 cells was assessed by real-time reverse-transcription polymerase chain reaction of osteoblast markers, namely, alkaline phosphatase, osteocalcin and bone sialoprotein. The results revealed that survival and proliferation of MG-63 cells were suppressed following exposure to nicotine, and cytoplasm vacuolization occurred in the cells. Nicotine significantly down-regulated the expression of osteogenic marker genes. Such adverse effects on morphology, viability and osteogenic gene expression of MG-63 cells were reversed by vitamin E therapy. In conclusion, vitamin E supplementation may play a role in proliferation and differentiation of osteoblasts, and vitamin E can be considered as an anabolic agent to treat nicotine-induced bone loss.