Satellite cells, muscle-specific stem cells, are anatomically identified as the mononuclear cells residing external to the myofiber plasma membrane and beneath the basal lamina. Skeletal muscle has great regenerative potential, and the regeneration process depends absolutely on satellite cells. In uninjured muscle, satellite cells are maintained in a quiescent state, ...

The mycotoxin T-2 toxin, produced by various Fusarium species, is a widespread contaminant of grain and grain products. Knowledge about its toxicity and metabolism in the human body is crucial for any risk assessment as T-2 toxin can be detected in processed and unprocessed food samples. Cell culture studies using ...

Human poisoning due to consumption of seafood contaminated with phycotoxins is a worldwide problem, and routine monitoring programs have been implemented in various countries to protect human consumers. Following successive episodes of unexplained shellfish toxicity since 2005 in the Arcachon Bay on the French Atlantic coast, a national research program ...

Yersinia entomophaga MH96, which was originally isolated from a New Zealand grass grub, Costelytra zealandica, produces an orally active proteinaceous toxin complex (Yen-Tc), and this toxin is responsible for mortality in a range of insect species, mainly within the Coleoptera and Lepidoptera. The genes encoding Yen-Tc are members of the ...

Notch signaling is a conserved cell fate regulator during development and postnatal tissue regeneration. Using skeletal muscle satellite cells as a model and through myogenic cell lineage-specific overexpression of constitutively activated Notch1 Intracellular Domain (NICD(OE)), here we investigate how Notch signaling regulates the cell fate choice of muscle stem cells. ...

Anthrax toxin is produced by Bacillus anthracis, the causative agent of anthrax, and is responsible for the majority of disease symptoms. The toxin consists of 3 proteins, protective antigen (PA), lethal factor (LF), and edema factor (EF), which combine to form lethal and edema toxin. Glycosaminoglycans, which are present on ...

This work describes the application of an impedance-based measurement for the real time evaluation of targeted tumor therapies in cell culture (HeLa cells). We used a treatment procedure that is well established in cells and mice. Therein, tumor cells are treated with a combination of an epidermal growth factor-based targeted ...

For a long time, colicin M was known for killing susceptible Escherichia coli cells by interfering with cell wall peptidoglycan biosynthesis, but its precise mode of action was only recently elucidated: this bacterial toxin was demonstrated to be an enzyme that catalyzes the specific degradation of peptidoglycan lipid intermediate II, ...

Although the release of intracellular toxins after chlorination has been reported, the relation between cell lysis and the release and degradation of toxins during chlorination has not been well illustrated. This study used Microcystis aeruginosa to investigate the release and degradation behaviors of toxins after its exposure to chlorine at ...

The aim of the present study was to investigate in vitro, whether cytolethality and oxidative damage is enhanced by combination of both mycotoxins as compared to their individual effect. In our paper, we applied a tiered in vitro experimental approach in order to predict the possible health risk effects of ...

Zymocin and PaT are killer toxins that induce cell cycle arrest of sensitive yeast cells in G1 and S phase, respectively. Recent studies have revealed that these two toxins cleave specific tRNAs, indicating that the cell growth impairment is due to the tRNA cleavage. Additionally, we have previously shown that ...

The binary Clostridium botulinum C2 toxin consists of the binding/translocation component C2IIa and the separate enzyme component C2I. C2IIa delivers C2I into the cytosol of eukaryotic target cells where C2I ADP-ribosylates actin. After receptor-mediated endocytosis of the C2IIa/C2I complex, C2IIa forms pores in membranes of acidified early endosomes and unfolded ...

An early determination of toxicant compounds of water contaminations can gain critical time to protect citizens' health and save substantial amounts of medical costs. To determine toxins in real time, a multi-dose classification algorithm using cellular state variable identification (CSVID) is developed in this paper. First, the dynamic cytotoxicity response ...

In this report, we studied the role of DNA damage signaling pathway in shiga toxin (STX)-induced mammalian cell death. Shiga toxin 1 exhibited cytotoxic activity in different mammalian cells such as HeLa cells, mouse embryo fibroblasts, and Caco-2 cells (a human intestinal primary fibroblast cell line). STX-1 was found to ...

Gymnodinium bloom events are of concern, since they produce toxins, which have unfavorable consequences to marine ecosystems, human health and the economy. This report describes the physico-chemical conditions that were present during the algal bloom event on May 2010 in Bahía Manzanillo and Bahía Santiago, Colima, Mexico. For this, seawater ...

We aimed to clarify if Campylobacter lari exerts a cytolethal distending toxin (CDT) effect on HeLa cells. Campylobacter cell lysates (CCLys) from C. jejuni 81-176 and urease-positive thermophilic Campylobacter (UPTC) CF89-12 and UPTC NCTC12893 isolates were shown to exert a CDT effect on HeLa cells with morphological changes examined by ...

VacA toxin from the cancer-inducing bacterium Helicobacter pylori is currently classified as a pore-forming toxin but is also considered a multifunctional toxin, apparently causing many pleiotropic cell effects. However, an increasing body of evidence suggests that VacA could be the prototype of a new class of monofunctional A-B toxins in ...

AIMS: To determine the relative toxicity and effects on the cell cycle of okadaic acid and dinophysistoxin-2 in primary hepatocyte cultures. MAIN METHODS: Cytotoxicity was determined by the MTT method, caspase-3 activity and lactate dehydrogenase release to the medium. The cell cycle analysis was performed by imaging flow cytometry and ...

Phospholipase C-gammal (PLC-gammal) expression is associated with cellular transformation. Notably, PLC-gamma is up-regulated in colorectal cancer tissue and breast carcinoma. Because exotoxins released by Clostridium botulinum have been shown to induce apoptosis and promote growth arrest in various cancer cell lines, we examined here the potential of Clostridium difficile toxin ...

Plastids have a multitude of functions in eukaryotic cells, ranging from photosynthesis to storage, and a role in essential biosynthetic pathways. All plastids are of either primary or higher-order endosymbiotic origin. That is, either a photosynthetic cyanobacterium was integrated into a mitochondriate eukaryotic host cell (primary endosymbiosis) or a plastid-bearing ...

Microsporidia are obligate intracellular fungal pathogens of increasing importance in immunocompromised patients. They have developed a unique invasion mechanism, which is based on the explosive discharge of a hollow tubulus, the so-called polar tube. The infectious sporoplasm is subsequently extruded through this flexible tube and injected into the host cell. ...

ABSTRACT: BACKGROUND: The periplasmic High Temperature Requirement protein A (HtrA) plays important roles in bacterial protein folding and stress responses. However, the role of chlamydial HtrA (cHtrA) in chlamydial pathogenesis is not clear. RESULTS: The cHtrA was detected both inside and outside the chlamydial inclusions. The detection was specific since ...

The Chlamydia-specific hypothetical protein CT795 was dominantly recognized by human antisera produced during C. trachomatis infection but not by animal antisera raised against dead chlamydia organisms. The immundominant region recognized by the human antibodies was mapped to the N-terminal fragment T22-S69. The endogenous CT795 was detected in the cytoplasm of ...

Dengue virus nonstructural protein 1 (NS1) is a glycoprotein involved in viral RNA replication. NS1 associates with host cell proteins and can be found in lipid raft domains on the host cell surface, suggesting an involvement in signal transduction events. In this work, we observed that NS1 expression in HepG2 ...

The molecular mechanisms of host cell invasion by T. cruzi metacyclic trypomastigotes (MT), the developmental forms that initiate infection in the mammalian host, are only partially understood. Here we aimed at further identifying the target cell components involved in signaling cascades leading to MT internalization, and demonstrate for the first ...

Intracellular pathogen-specific antibodies (Abs) can contribute to host protection by a number of different mechanisms. Ab opsonization of pathogens residing outside a host cell can prevent infection of target cells either via neutralization of the critical surface epitopes required for host cell entry, complement-mediated degradation, or via subsequent intracellular degradation. ...

Phospholipases are a diverse class of enzymes produced both by eukaryotic hosts and their pathogens. Major insights into action pathways of bacterial phospholipases have been provided during the last years. On the one hand bacterial phospholipases act as potent membrane destructors and on the other hand they manipulate and initiate ...

Invasion of host cells by apicomplexan parasites is initiated when specialized secretory organelles called micronemes discharge protein complexes onto the parasite surface in response to a rise in parasite intracellular calcium levels. The microneme proteins establish interactions with host cell receptors, engaging the parasite with the host cell surface, and ...

The nutrient sensor O-GlcNAc transferase modifies proteins with the O-GlcNAc moiety. In this issue, Capotosti et al. (2011) reveal that O-GlcNAc transferase not only glycosylates the cell-cycle regulator host cell factor 1 but activates it through proteolytic cleavage, providing a surprising link between metabolism and epigenetic regulation of the cell cycle.

The response of cells to a chemical or biological agent in terms of their impedance changes in real-time is a useful mechanism that can be utilized for a wide variety of biomedical and environmental applications. The use of a single-cell-based analytical platform could be an effective approach to acquiring more ...

The Gram-positive bacterial cell wall presents a structural barrier that requires modification for protein secretion and large-molecule transport as well as for bacterial growth and cell division. The Gram-positive bacterium Listeria monocytogenes adjusts cell wall architecture to promote its survival in diverse environments that include soil and the cytosol of ...

Many intracellular pathogens hijack host cell actin or its regulators for cell-to-cell spreading. In marked contrast, apicomplexan parasites, obligate intracellular, single cell eukaryotes that are phylogenetically older than the last common ancestor of animals and plants, employ their own actin cytoskeleton for active motility through tissues and invasion of host ...

The pathogenic Yersinia species share a conserved type III secretion system, which delivers cytotoxic effectors known as Yops into target mammalian cells. In all three species, YopK (also called YopQ) plays an important role in regulating this process. In cell culture infections, yopK mutants inject higher levels of Yops, leading ...

The Helicobacter pylori protein CagA (cytotoxin-associated gene A) is associated with an increased risk for gastric cancer formation. After attachment to epithelial cells, the bacteria inject CagA via a type IV secretion apparatus into host cells, where it exerts its biological activity. Host cell responses to intracellular CagA have been ...

Invasive bacterial pathogens such as Shigella flexneri force their uptake into non-phagocytic host cells. Upon internalization, they rupture the endocytic vacuole and escape into the host cell cytoplasm. Recent studies applying fluorescence resonance energy transfer (FRET) based methods to track host-pathogen interactions have provided insights into the process of bacterial ...

The protozoan parasite Entamoeba histolytica is responsible for invasive intestinal and extraintestinal amebiasis. The virulence of Entamoeba histolytica is strongly correlated with the parasite's capacity to effectively kill and phagocytose host cells. The process by which host cells are killed and phagocytosed follows a sequential model of adherence, cell killing, ...

The recent introduction of "oxygen-independent" flavin mononucleotide (FMN)-based fluorescent proteins (FbFPs) is of major interest to both eukaryotic and prokaryotic microbial biologists. Accordingly, we demonstrate for the first time that an obligate anaerobe, the successful opportunistic pathogen of the oral cavity, Porphyromonas gingivalis, can be genetically engineered for expression of ...

Theileria annulata is an intracellular protozoan parasite that infects B cells and macrophages of ruminants. Macrophages infected with T. annulata are de-differentiated and display tumour cell properties and a metastatic behaviour. How parasitized cells adapt their morphology, motility and invasive behaviour has not yet been addressed in detail. In this ...

Mycobacterium tuberculosis is the causative agent of tuberculosis disease, which has developed a myriad of exceptional features contributing to its survival within the hostile environment of host cell. Unique cell wall structure with high lipid content plays an imperative role in the pathogenicity of mycobacteria. Cell wall components of MTB ...

Striatal carotid body cell aggregates (CBCA) grafts improve parkinsonism in animals and patients with Parkinson's disease. As CB cells contain trophic factors, we investigated the long-term effect of striatal CBCA grafts on nigrostriatal dopaminergic cells in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated monkeys receiving unilateral (UL-grafted group, n=4) or bilateral (BL-grafted group, n=3) CBCA ...

Pathogenic Yersinia species inject a panel of Yop virulence proteins by type III protein secretion into host cells to modulate cellular defense responses. This enables the survival and dissemination of the bacteria in the host lymphoid tissue. We have previously shown that YopE of the Y. enterocolitica serogroup O8 is ...

Bacterial exotoxins exploit protein transport pathways of their mammalian target cells to deliver their enzymatic active moieties into the cytosol. There, they modify their specific substrate molecules resulting in cell damage and the clinical symptoms characteristic for each individual toxin. We have investigated the cellular uptake of the binary actin ...

Candida albicans is part of the normal human flora, and it grows on mucosal surfaces in healthy individuals. In susceptible hosts, this organism can cause both mucosal and hematogenously disseminated disease. For C. albicans to persist in the host and induce disease, it must be able to adhere to biotic ...

The enteroinvasive bacterium Shigella flexneri uses multiple secreted effector proteins to downregulate interleukin-8 (IL-8) expression in infected epithelial cells. Yet, massive IL-8 secretion is observed in Shigellosis. Here we report a host mechanism of cell-cell communication that circumvents the effector proteins and strongly amplifies IL-8 expression during bacterial infection. By ...

We show that following oral inoculation, prions bind to ileal Peyer patch and cecal patch microfold cells (M cells) in vivo. Furthermore, we show evidence that the cecum acts a biological sump holding large concentrations of prions for relatively long periods, thus increasing the exposure time of cecal patch M ...

Female reproductive tract (FRT) epithelial cells protect against potential pathogens and sexually transmitted infections. The purpose of this study was to determine if epithelial cells from the upper FRT secrete antimicrobials that inhibit reproductive tract pathogens that threaten women's health. Apical secretions from primary cultures of Fallopian tube, uterine, cervical, ...

This study investigated the effect of the extract of Bupleuri Radix (BRE) on the infection of Madin-Darby Canine Kidney (MDCK) cells by anti-H1N1 virus. The effect of BRE on RANTES (the chemokine regulated on activation, normal T cells expressed and secreted) secretion in H1N1-infected A549 cells (human bronchial epithelial cells) ...

The obligate intracellular bacterium Parachlamydia acanthamoebae is a potential human pathogen, but the host range of the bacteria remains unknown. Hence, the growth of P. acanthamoebae Bn₉ in protozoa (Tetrahymena, Acanthamoeba, Dictyostelium) and mammalian cells (HEp-2, Vero, THP-1, PMA-stimulated THP-1, Jurkat) was assessed using an AIU assay which had been ...

In a previous study, we reported that a gene mutation of repeat in toxin E (RtxE), a transporter of cytotoxic factors, resulted in a significant impairment of epithelial cell cytotoxicity in Vibrio vulnificus, and that the expression of the rtxE gene was induced by the exposure to the host cells. ...

Some hundred cells of Chlorella-like green algae are naturally enclosed within the cytoplasm of a single cell of green paramecia (Paramecium bursaria). Therefore, P. bursaria serves as an experimental model for studying the nature of endo-symbiosis made up through chemical communication between the symbiotic partners. For studying the mechanism of ...