scholarly journals Macropinocytosis as a Mechanism of Entry into Primary Human Urethral Epithelial Cells by Neisseria gonorrhoeae

2000 ◽  
Vol 68 (3) ◽  
pp. 1696-1699 ◽  
Author(s):  
Michael K. Zenni ◽  
Peter C. Giardina ◽  
Hillery A. Harvey ◽  
Jianqiang Shao ◽  
Margaret R. Ketterer ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Laser Scanning ◽  
Actin Polymerization ◽  
Kinase Inhibitors ◽  
Fluorescein Isothiocyanate ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Transmission Electron ◽  
Microscopy Analysis ◽  
Phosphoinositide 3 Kinase

ABSTRACT Gonococcal entry into primary human urethral epithelial cells (HUEC) can occur by macropinocytosis. Scanning and transmission electron microscopy revealed lamellipodia surrounding gonococci, and confocal laser scanning microscopy analysis showed organisms colocalized with M r 70,000 fluorescein isothiocyanate-labeled dextran within the cells. Phosphoinositide 3-kinase inhibitors and an actin polymerization inhibitor prevented macropinocytic entry of gonococci into HUEC.

Contribution of Microscopy to a Better Knowledge of the Biology ofGiardia lamblia

2004 ◽  
Vol 10 (5) ◽  
pp. 513-527 ◽  
Author(s):  
Wanderley de Souza ◽  
Adriana Lanfredi-Rangel ◽  
Loraine Campanati
Keyword(s):  
Golgi Complex ◽  
Laser Scanning ◽  
Diarrheal Disease ◽  
Freeze Fracture ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Enzyme Cytochemistry ◽  
Morphological Studies ◽  
Transmission Electron ◽  
Microscopic Techniques

Giardia lambliais a flagellated protozoan of great medical and biological importance. It is the causative agent of giardiasis, one of the most prevalent diarrheal disease both in developed and third-world countries. Morphological studies have shown thatG. lambliadoes not present structures such as peroxisomes, mitochondria, and a well-elaborated Golgi complex. In this review, special emphasis is given to the contribution made by various microscopic techniques to a better knowledge of the biology of the protozoan. The application of video microscopy, immunofluorescence confocal laser scanning microscopy, and several techniques associated with transmission electron microscopy (thin section, enzyme cytochemistry, freeze-fracture, deep-etching, fracture-flip) to the study of the cell surface, peripheral vesicles, endoplasmic reticulum–Golgi complex system, and of the encystation vesicles found in trophozoites and during the process of trophozoite-cyst transformation are discussed.

scholarly journals Primary Neurons and Differentiated NSC-34 Cells Are More Susceptible to Arginine-Rich ALS Dipeptide Repeat Protein-Associated Toxicity than Non-Differentiated NSC-34 and CHO Cells

2019 ◽  
Vol 20 (24) ◽  
pp. 6238 ◽  
Author(s):  
Anna L. Gill ◽  
Monica Z. Wang ◽  
Beth Levine ◽  
Alan Premasiri ◽  
Fernando G. Vieira
Keyword(s):  
Motor Neurons ◽  
Laser Scanning ◽  
Neuronal Cell ◽  
Fluorescein Isothiocyanate ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Primary Neurons ◽  
Repeat Protein ◽  
Neuronal Cell Lines ◽  
Dipeptide Repeat

A repeat expansion mutation in the C9orf72 gene is the most common known genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). In this study, using multiple cell-based assay systems, we reveal both increased dipeptide repeat protein (DRP) toxicity in primary neurons and in differentiated neuronal cell lines. Using flow cytometry and confocal laser scanning microscopy of cells treated with fluorescein isothiocyanate (FITC)-labeled DRPs, we confirm that poly-glycine-arginine (GR) and poly-proline-arginine (PR) DRPs entered cells more readily than poly-glycine-proline (GP) and poly-proline-alanine (PA) DRPs. Our findings suggest that the toxicity of C9-DRPs may be influenced by properties associated with differentiated and aging motor neurons. Further, our findings provide sensitive cell-based assay systems to test phenotypic rescue ability of potential interventions.

Microtubule targeted therapeutics loaded polymeric assembled nanospheres for potentiation of antineoplastic activity

2016 ◽  
Vol 186 ◽  
pp. 45-59 ◽  
Author(s):  
Radhika Poojari ◽  
Rohit Srivastava ◽  
Dulal Panda
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Laser Scanning ◽  
Present Approach ◽  
Laser Scanning Microscopy ◽  
Microtubule Assembly ◽  
Confocal Laser ◽  
Cancer Cell Proliferation ◽  
Transmission Electron ◽  
Hepatocarcinoma Cells

Polymeric nanoassemblies represent an attractive strategy for efficient cellular internalization of microtubule targeted anticancer drugs. Using dynamic light scattering, zeta potential, transmission electron microscopy and scanning electron microscopy, the physical properties and surface morphology of microtubule-binding PEGylated PLGA assembled nanospheres (100–200 nm) were analyzed. The present approach leads to strong internalization as observed by confocal laser scanning microscopy and transmission electron microscopy in hepatocarcinoma cells. The effect of these nanoassemblies on microtubules and mitosis were explored using immunofluorescence microscopy. The effects of these nanoassemblies on cancer cell proliferation and cell death revealed their antitumor enhancing effects. Perturbation of the microtubule assembly, mitosis and nuclear modulations potentiated the antineoplastic effects delivered via nanospheres in hepatocarcinoma cells. The extensive biomolecular and physical characterizations of the synthesized nanoassemblies will help to design potent therapeutic materials and the present approach can be applied to deliver microtubule-targeted drugs for liver cancer therapy.

scholarly journals HtrA Homologue of Legionella pneumophila: an Indispensable Element for Intracellular Infection of Mammalian but Not Protozoan Cells

2001 ◽  
Vol 69 (4) ◽  
pp. 2569-2579 ◽  
Author(s):  
Lisa L. Pedersen ◽  
Marina Radulic ◽  
Miljenko Doric ◽  
Yousef Abu Kwaik
Keyword(s):  
Epithelial Cells ◽  
Confocal Laser Scanning Microscopy ◽  
Legionella Pneumophila ◽  
Parental Strain ◽  
Laser Scanning ◽  
Alveolar Epithelial Cells ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Intracellular Replication ◽  
Alveolar Epithelial

ABSTRACT Legionella pneumophila replicates within alveolar macrophages, and possibly, alveolar epithelial cells and also within protozoa in the aquatic environment. Here we characterize an L. pneumophila mutant defective in the HtrA/DegP stress-induced protease/chaperone homologue and show that HtrA is indispensable for intracellular replication within mammalian macrophages and alveolar epithelial cells and for intrapulmonary replication in A/J mice. Importantly, amino acid substitutions of two conserved residues in the catalytic domain of (H103➤R and S212➤A) and in-frame deletions of either or both of the two conserved PDZ domains of HtrA abolish its function. Interestingly, the htrAmutant exhibits a parental-type phenotype in intracellular replication within the protozoan host Acanthamoeba polyphaga. We used a promoterless lacZ fusion to the htrApromoter to probe the phagosomal microenvironment harboringL. pneumophila within macrophages and within A. polyphaga for the exposure to stress stimuli. The data show that expression through the htrA promoter is induced by 12,000- to 20,000-fold throughout the intracellular infection of macrophages but its induction is by 120- to 500-fold within protozoa compared to in vitro expression. Data derived from confocal laser scanning microscopy reveal that in contrast to the parental strain, phagosomes harboring the htrA mutant within U937 macrophages colocalize with the late endosomal-lysosomal marker LAMP-2, similar to killed L. pneumophila. Coinfection experiments examined by confocal laser scanning microscopy show that in communal phagosomes harboring both the parental strain and the htrA mutant, replication of the mutant is not rescued, while replication of a dotAmutant control, which is normally trafficked into a phagolysosome, is rescued by the parental strain. Our data show, for the first time, that the stress response by L. pneumophila (mediated, at least in part, by HtrA) is indispensable for intracellular replication within mammalian but not protozoan cells.

Confocal microscopy analysis of native, full length and B-domain deleted coagulation factor VIII trafficking in mammalian cells

2004 ◽  
Vol 92 (07) ◽  
pp. 23-35 ◽  
Author(s):  
Sven Becker ◽  
Jeremy Simpson ◽  
Rainer Pepperkok ◽  
Stefan Heinz ◽  
Christian Herder ◽  
...  
Keyword(s):  
Factor Viii ◽  
Golgi Complex ◽  
Mammalian Cells ◽  
Laser Scanning ◽  
Coagulation Factor ◽  
Full Length ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Microscopy Analysis ◽  
Recombinant Fviii

SummaryIn mammalian cells, factor VIII (FVIII) secretion depends upon its interaction with chaperones of the endoplasmic reticulum (ER) and requires a unique ATP-dependent step to dissociate aggregates formed within the ER. To further elucidate mechanisms which might account for the inefficient secretion of recombinant FVIII (rFVIII), we have analyzed the pathways of recombinant full length (rFVIII-FL) and B-domain deleted (rFVIIIΔB) FVIII and compared these to the secretion route of native FVIII in primary hepatocytes. Using confocal laser scanning microscopy in combination with a pulse chase of a known secretion marker, we describe the trafficking route of FVIII, which upon release from the ER – where it colocalizes with calnexin – is transported to the Golgi complex in vesiculartubular transport complexes (VTCs) which could be further identified as being COP I coated. However, a large portion of rFVIII is retained in the ER and additionally in structures which could not be assigned to the ER, Golgi complex or intermediate compartment. Moderate BiP transcription levels indicate that this observed retention of FVIII does not reflect cellular stress due to an overexpression of FVIII-protein in transduced cells. Moreover, a pulse of newly synthesized rFVIII protein is released within 4 hrs, indicating that once rFVIII is released from the ER there is no further limitation to its secretion. Our data provide new details about the secretory route of FVIII, which may ultimately help to identify factors currently limiting the efficient and physiological expression of FVIII in gene therapy and manufacture.

Soft Tissue and Epithelial Models

1999 ◽  
Vol 13 (1) ◽  
pp. 57-66 ◽  
Author(s):  
J.A. Jansen ◽  
E.T. Den Braber ◽  
X.F. Walboomers ◽  
J.E. De Ruijter
Keyword(s):  
Laser Scanning ◽  
Analytical Techniques ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Good Tool ◽  
Oral Implants ◽  
Body Tissues ◽  
Transmission Electron ◽  
Gingival Cells

The applicability of a biomaterial for the manufacturing of oral implants is determined by its physicochemical and geometric surface properties. Research, therefore, is concerned with the cellular reactions that occur when an implant material comes into contact with body tissues. For permucosal oral implants, this involves both the reaction of bone and gingival cells. In vitro cell culturing-including the use of various analytical techniques like light microscopy, scanning and transmission electron microscopy, confocal laser scanning microscopy, and digital image analysis-is a good tool whereby investigators can obtain more insight into the relevant components of implant-tissue adhesion. In the current overview, the role of cell models in oral implant research is discussed, specifically with reference to responses of epithelial cells and fibroblasts.

Sudan Black B Reduces Autofluorescence in Murine Renal Tissue

2011 ◽  
Vol 135 (10) ◽  
pp. 1335-1342 ◽  
Author(s):  
Yan Sun ◽  
Hong Yu ◽  
Dong Zheng ◽  
Qi Cao ◽  
Ya Wang ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Kidney Tissue ◽  
Fluorescein Isothiocyanate ◽  
Renal Tissue ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Frozen Sections ◽  
Paraffin Sections ◽  
Biopsy Material ◽  
Sudan Black B

Context.—Renal tissue emits intense autofluorescence, making it difficult to differentiate specific immunofluorescence signals and thus limiting its application to clinical biopsy material. Objective.—To identify and minimize autofluorescence of renal tissue and demonstrate a simple, efficient method to reduce autofluorescence using Sudan black B. Design.—In this study, the sources and features of autofluorescence emitted from kidney tissue were examined. Broad autofluorescence was visualized in both frozen and paraffin kidney sections of normal mice and mice with Adriamycin-induced nephropathy using confocal laser scanning microscopy. Autofluorescence appeared in commonly used 4′,6-diamidino-2-phenylindole, fluorescein isothiocyanate, and Texas Red channels but not in far-red channel, and emitted extensively from red cells, injured tubulointersitial cells, and protein casts in diseased kidney. To eliminate autofluorescence, Sudan black B was used on formaldehyde-fixed paraffin sections and frozen sections of mouse kidney. The effects of Sudan black B in various concentrations were tested on kidney tissue. Results.—The 0.1% Sudan black B effectively blocked autofluorescence from both paraffin and frozen sections without adversely affecting specific fluorescence signals. Interestingly, the solvent for Sudan black B, 70% ethanol, was also shown to reduce autofluorescence on frozen sections, but not on paraffin sections. Conclusions.—This study demonstrates a simple, efficient, and cost-effective method to reduce autofluorescence using Sudan black B, and also provides a comprehensive approach to identify and minimize autofluorescence of renal tissue.

Sign in / Sign up

Export Citation Format

Share Document