A Brucella abortus cstA mutant is defective for association with endoplasmic reticulum exit sites and displays altered trafficking in HeLa cells

Microbiology ◽  
2012 ◽  
Vol 158 (10) ◽  
pp. 2610-2618 ◽  
Author(s):  
Marie de Barsy ◽  
Aurélie Mirabella ◽  
Jean-Jacques Letesson ◽  
Xavier De Bolle
Keyword(s):  
Endoplasmic Reticulum ◽  
Hela Cells ◽  
Brucella Abortus

scholarly journals Brucella abortus Transits through the Autophagic Pathway and Replicates in the Endoplasmic Reticulum of Nonprofessional Phagocytes

1998 ◽  
Vol 66 (12) ◽  
pp. 5711-5724 ◽  
Author(s):  
Javier Pizarro-Cerdá ◽  
Stéphane Méresse ◽  
Robert G. Parton ◽  
Gisou van der Goot ◽  
Alberto Sola-Landa ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Hela Cells ◽  
Brucella Abortus ◽  
Cathepsin D ◽  
Bacterial Strains ◽  
Infected Cells ◽  
Bacterial Replication ◽  
Protein Disulfide ◽  
Intracellular Pathway ◽  
Replication Compartment

ABSTRACT Brucella abortus is an intracellular pathogen that replicates within a membrane-bounded compartment. In this study, we have examined the intracellular pathway of the virulent B. abortus strain 2308 (S2308) and the attenuated strain 19 (S19) in HeLa cells. At 10 min after inoculation, both bacterial strains are transiently detected in phagosomes characterized by the presence of early endosomal markers such as the early endosomal antigen 1. At ∼1 h postinoculation, bacteria are located within a compartment positive for the lysosome-associated membrane proteins (LAMPs) and the endoplasmic reticulum (ER) marker sec61β but negative for the mannose 6-phosphate receptors and cathepsin D. Interestingly, this compartment is also positive for the autophagosomal marker monodansylcadaverin, suggesting that S2308 and S19 are located in autophagic vacuoles. At 24 h after inoculation, attenuated S19 is degraded in lysosomes, while virulent S2308 multiplies within a LAMP- and cathepsin D-negative but sec61β- and protein disulfide isomerase-positive compartment. Furthermore, treatment of infected cells with the pore-forming toxin aerolysin from Aeromonas hydrophila causes vacuolation of the bacterial replication compartment. These results are compatible with the hypothesis that pathogenic B. abortus exploits the autophagic machinery of HeLa cells to establish an intracellular niche favorable for its replication within the ER.

Use of Uranium-Labeled Antibodies for Electron Microscopic Localization of Various Antigens in Mammalian Cells

1967 ◽  
Vol 25 ◽  
pp. 136-137
Author(s):  
J. P. Petrali ◽  
E. J. Donati ◽  
L. A. Sternberger
Keyword(s):  
Endoplasmic Reticulum ◽  
Hela Cells ◽  
Mammalian Cells ◽  
Specific Antiserum ◽  
Electron Microscopic ◽  
E Coli ◽  
Cytoplasmic Membranes ◽  
Viral Progeny ◽  
Ultrathin Sections ◽  
Electron Microscopic Localization

Specific contrast is conferred to subcellular antigen by applying purified antibodies, exhaustively labeled with uranium under immunospecific protection, to ultrathin sections. Use of Seligman’s principle of bridging osmium to metal via thiocarbohydrazide (TCH) intensifies specific contrast. Ultrathin sections of osmium-fixed materials were stained on the grid by application of 1) thiosemicarbazide (TSC), 2) unlabeled specific antiserum, 3) uranium-labeled anti-antibody and 4) TCH followed by reosmication. Antigens to be localized consisted of vaccinia antigen in infected HeLa cells, lysozyme in monocytes of patients with monocytic or monomyelocytic leukemia, and fibrinogen in the platelets of these leukemic patients. Control sections were stained with non-specific antiserum (E. coli).In the vaccinia-HeLa system, antigen was localized from 1 to 3 hours following infection, and was confined to degrading virus, the inner walls of numerous organelles, and other structures in cytoplasmic foci. Surrounding architecture and cellular mitochondria were unstained. 8 to 14 hours after infection, antigen was localized on the outer walls of the viral progeny, on cytoplasmic membranes, and free in the cytoplasm. Staining of endoplasmic reticulum was intense and focal early, and weak and diffuse late in infection.

Temporal and spatial interrelationships of confronting cisternae to nuclear envelope

1992 ◽  
Vol 50 (1) ◽  
pp. 930-931
Author(s):  
John R. Palisano
Keyword(s):  
Endoplasmic Reticulum ◽  
Nuclear Envelope ◽  
Tumor Cells ◽  
Hela Cells ◽  
Microscopic Investigation ◽  
Electron Microscopic Investigation ◽  
Serial Sections ◽  
Electron Microscopic ◽  
Fetal Rat ◽  
Temporal And Spatial

Although confronting cistemae (CC) have been observed in a variety of tumor cells and normal fetal rat, mouse, and human epithelial tissues, little is known about their origin or role in mitotic cells. While several investigators have suggested that CC arise from nuclear envelope (NE) folding back on itself during prophase, others have suggested that CC arise when fragments of NE pair with endoplasmic reticulum. An electron microscopic investigation of 0.25 um thick serial sections was undertaken to examine the origin of CC in HeLa cells.

Apigetrin Promotes Cell Autophagy by Activating the Endoplasmic Reticulum Stress in Human Cervical Cancer Hela Cells

2021 ◽  
Vol 20 (1) ◽  
pp. 56-63
Author(s):  
Li Jiang ◽  
Zhi-Cheng Yao ◽  
Miao-Miao Liu ◽  
Run-Hui Ma ◽  
Kiran Thakur
Keyword(s):  
Cervical Cancer ◽  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Hela Cells ◽  
Fruits And Vegetables ◽  
Radical Scavenging ◽  
Anticancer Activities ◽  
Treatment Results ◽  
Metastasis Rate ◽  
The Relationship

Cervical cancer has always been the top malignant cancer among female cancers in the world. Due to its recurrence, metastasis rate, and drug resistance, the treatment results of cervical cancer have been unsatisfactory. Apigetrin is present in a variety of fruits and vegetables and has been reported to have antioxidant, free radical scavenging, anti-inflammatory, and anticancer activities. Therefore, this study focuses on the effect of apigetrin on the autophagy of cervical cancer HeLa cells based on the previous research. The results showed that apigetrin can enhance the autophagy fluorescence of light chain 3B (LC3B), and further combined with quantitative real-time PCR (qPCR) and Western blotting found that the expression of autophagy-related genes and proteins p-mTOR, Beclin1, and LC3B increased, while the expression of AMPK, ULK1, and p62 decreased. In addition, apigetrin also promoted the release of Ca2+, the PERK/eIF2α/ATF4/chop, and IRE1α pathways activate endoplasmic reticulum (ER) stress. The addition of 4PBA proved that ER stress promoted autophagy in HeLa cells. Finally, the addition of the 3-MA indicates the relationship between autophagy and apoptosis in HeLa cells. Our results indicate that apigetrin has a certain anticancer potential and can be used as a drug adjuvant and food additive for the prevention and treatment of cervical cancer.

Brucella abortus efp gene is required for an efficient internalization in HeLa cells

2012 ◽  
Vol 52 (1) ◽  
pp. 31-40 ◽  
Author(s):  
Florencia Iannino ◽  
Juan E. Ugalde ◽  
Nora Iñón de Iannino
Keyword(s):  
Hela Cells ◽  
Brucella Abortus

scholarly journals Co-involvement of the mitochondria and endoplasmic reticulum in cell death induced by the novel ertargeted protein HAP

2006 ◽  
Vol 11 (2) ◽  
Author(s):  
Hua Xu ◽  
Qing Zhou ◽  
Xin Liu ◽  
Yi-Peng Qi
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Death ◽  
Membrane Potential ◽  
Hela Cells ◽  
Cell Apoptosis ◽  
Mitochondrial Membrane ◽  
Caspase 3 ◽  
Protein A ◽  
The Novel ◽  
Induce Cell Apoptosis

AbstractHAP (a homologue of the ASY/Nogo-B protein), a novel human apoptosis-inducing protein, was found to be identical to RTN3. In an earlier study, we demonstrated that HAP localized exclusively to the endoplasmic reticulum (ER) and that its overexpression could induce cell apoptosis via a depletion of endoplasmic reticulum (ER) Ca2+ stores. In this study, we show that overexpression of HAP causes the activation of caspase-12 and caspase-3. We still detected the collapse of mitochondrial membrane potential (Δωm) and the release of cytochrome c in HAP-overexpressing HeLa cells. All the results indicate that both the mitochondria and the ER are involved in apoptosis caused by HAP overexpression, and suggest that HAP overexpression may initiate an ER overload response (EOR) and bring about the downstream apoptotic events.

scholarly journals Endoplasmic reticulum positioning and partitioning in mitotic HeLa cells

2005 ◽  
Vol 206 (5) ◽  
pp. 415-425 ◽  
Author(s):  
Simon McCullough ◽  
John Lucocq
Keyword(s):  
Endoplasmic Reticulum ◽  
Hela Cells

scholarly journals Induction of calreticulin expression in HeLa cells by depletion of the endoplasmic reticulum Ca2+ store and inhibition of N-linked glycosylation

1996 ◽  
Vol 318 (2) ◽  
pp. 555-560 ◽  
Author(s):  
David H LLEWELLYN ◽  
Jonathan M. KENDALL ◽  
SHEIKH Naureen ◽  
Anthony K. F. CAMPBELL
Keyword(s):  
Endoplasmic Reticulum ◽  
Hela Cells ◽  
Transcriptional Activation ◽  
Prolonged Exposure ◽  
Transcriptional Start Site ◽  
Firefly Luciferase ◽  
Luciferase Expression ◽  
Primary Role ◽  
Transfected Cells ◽  
Promoter Construct

Calreticulin is now considered to be a multifunctional Ca2+-binding protein. Its primary role is as a Ca2+ storage protein within the lumen of the endoplasmic reticulum (ER), where it also seems to assist in the correct folding and assembly of proteins. We have investigated whether agents that affect these processes can alter calreticulin expression in HeLa cells. Perturbation of intracellular Ca2+ levels by prolonged exposure to either thapsigargin or ionomycin induced calreticulin mRNA, both in the presence and absence of extracellular Ca2+, consistent with the proposal that sustained depletion of the ER Ca2+ store can trigger these increases. The mechanism underlying the induction seems to be transcriptional up-regulation as both agents increased calreticulin promoter-driven firefly luciferase expression in transfected cells to the same degree as the observed increases in calreticulin mRNA. Experiments with a truncated promoter construct showed that the sequences that confer this inducibility reside within the 225 bp immediately upstream of the putative major transcriptional start site. We also examined the effect of tunicamycin, which inhibits N-linked glycosylation in the ER thereby interfering with protein processing. This caused increases in calreticulin mRNA greater than those with either thapsigargin or ionomycin, but failed to transactivate the calreticulin promoter. Thus either additional cis sequences that reside outside our promoter region are necessary for transcriptional activation by tunicamycin, or the increases in calreticulin mRNA occur post-transcriptionally. This suggests that there are probably different mechanisms by which calreticulin expression can be induced in response to agents that affect normal ER functioning.

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