scholarly journals PINK1/Parkin-Mediated Mitophagy Promotes Resistance to Sonodynamic Therapy

2018 ◽  
Vol 49 (5) ◽  
pp. 1825-1839 ◽  
Author(s):  
Lin Song ◽  
Yongmin Huang ◽  
Xuandi Hou ◽  
Yaoheng Yang ◽  
Shashwati Kala ◽  
...  
Keyword(s):  
Cell Death ◽  
Cell Fate ◽  
Immunofluorescence Microscopy ◽  
Aminolevulinic Acid ◽  
Mitochondrial Dynamics ◽  
Breast Adenocarcinoma ◽  
Sonodynamic Therapy ◽  
Confocal Immunofluorescence Microscopy ◽  
Confocal Immunofluorescence ◽  
Mcf 7

Background/Aims: Sonodynamic therapy (SDT), based on the synergistic effect of low-intensity ultrasound and sonosensitizer, is a potential approach for non-invasive treatment of cancers. In SDT, mitochondria played a crucial role in cell fate determination. However, mitochondrial activities and their response to SDT remain elusive. The purpose of this study was to examine the response of mitochondria to SDT in tumor cells. Methods: A human breast adenocarcinoma cell line - MCF-7 cells were subjected to 5-aminolevulinic acid (ALA)-SDT, with an average ultrasonic intensity of 0.25W/cm2. Mitochondrial dynamics and redox balance were examined by confocal immunofluorescence microscopy and western blot. The occurrence of mitophagy was determined by confocal immunofluorescence microscopy. Results: Our results showed that ALA-SDT could induce mitochondrial dysfunction through mitochondrial depolarization and fragmentation and lead to mitophagy. The Parkin-dependent signaling pathway was involved and promoted resistance to ALA-SDT induced cell death. Finally, excessive production of ROS was found to be necessary for the initiation of mitophagy. Conclusion: Taken together, we conclude that ROS produced by 5-ALA-SDT could initiate PINK1/Parkin-mediated mitophagy which may exert a protective effect against 5-ALA-SDT-induced cell death in MCF-7 cells.

Enhancement of docetaxel-treated MCF-7 cell death by 900-MHz radiation

2013 ◽  
Vol 8 (4) ◽  
pp. 357-365
Author(s):  
Marianna Trebuňová ◽  
Galina Laputková ◽  
Imrich Géci ◽  
Igor Andrašina ◽  
Ján Sabo
Keyword(s):  
Cell Culture ◽  
Cell Death ◽  
Electromagnetic Field ◽  
High Frequency ◽  
Input Power ◽  
Breast Adenocarcinoma ◽  
Human Breast ◽  
Human Breast Adenocarcinoma ◽  
High Frequency Electromagnetic Field ◽  
Mcf 7

AbstractThe aim of the study was to investigate the effect of high-frequency electromagnetic field of 900 MHz at 8 W input power on metabolic activity of human breast adenocarcinoma MCF-7 cells. With the aid of the colorimetric MTT assay, it was shown that there is significant change in cell culture survival exposed to docetaxel in field-free conditions in comparison with cells treated with docetaxel simultaneously exposed to high-frequency electromagnetic field.

scholarly journals Human Rhinovirus Type 2 Is Internalized by Clathrin-Mediated Endocytosis

2003 ◽  
Vol 77 (9) ◽  
pp. 5360-5369 ◽  
Author(s):  
Luc Snyers ◽  
Hannes Zwickl ◽  
Dieter Blaas
Keyword(s):  
Plasma Membrane ◽  
Hela Cells ◽  
Immunofluorescence Microscopy ◽  
Dominant Negative ◽  
Human Rhinovirus ◽  
Coated Pits ◽  
Confocal Immunofluorescence Microscopy ◽  
Confocal Immunofluorescence ◽  
Transient Overexpression

ABSTRACT Using several approaches, we investigated the importance of clathrin-mediated endocytosis in the uptake of human rhinovirus serotype 2 (HRV2). By means of confocal immunofluorescence microscopy, we show that K+ depletion strongly reduces HRV2 internalization. Viral uptake was also substantially reduced by extraction of cholesterol from the plasma membrane with methyl-β-cyclodextrin, which can inhibit clathrin-mediated endocytosis. In accordance with these data, overexpression of dynamin K44A in HeLa cells prevented HRV2 internalization, as judged by confocal immunofluorescence microscopy, and strongly reduced infection. We also demonstrate that HRV2 bound to the surface of HeLa cells is localized in coated pits but not in caveolae. Finally, transient overexpression of the specific dominant-negative inhibitors of clathrin-mediated endocytosis, the SH3 domain of amphiphysin and the C-terminal domain of AP180, potently inhibited internalization of HRV2. Taken together, these results indicate that HRV2 uses clathrin-mediated endocytosis to infect cells.

Involvement of myosin VI immunoanalog in pinocytosis and phagocytosis in Amoeba proteus

2008 ◽  
Vol 86 (6) ◽  
pp. 509-519 ◽  
Author(s):  
Magdalena Sobczak ◽  
Anna Wasik ◽  
Wanda Kłopocka ◽  
Maria Jolanta Rędowicz
Keyword(s):  
Electron Microscopy ◽  
Immunofluorescence Microscopy ◽  
Amoeba Proteus ◽  
Myosin Vi ◽  
Filamentous Actin ◽  
Confocal Immunofluorescence Microscopy ◽  
Endogenous Protein ◽  
Confocal Immunofluorescence ◽  
Pinocytotic Vesicles ◽  
Phagocytic Cups

Recently, we found a 130-kDa myosin VI immunoanalog in amoeba, which bound to actin in an ATP-sensitive manner and in migrating amoebae colocalized to filamentous actin and dynamin II-containing vesicular structures. To further characterize this protein, we assessed its involvement in amoeba pinocytosis and phagocytosis. Confocal immunofluorescence microscopy and electron microscopy of immunogold-stained cells revealed that, in pinocytotic and phagocytotic amoebae, the myosin VI immunoanalog was visible throughout the cells, including pinocytotic channels and pinocytotic vesicles as well as phagosomes and emerging phagocytic cups. Blocking endogenous protein with anti-porcine myosin VI antibody (introduced into cells by means of microinjection) caused severe defects in pinocytosis and phagocytosis. In comparison with control cells, the treated amoebae formed ~75% less pinocytotic channels and phagocytosed ~65% less Tetrahymena cells. These data indicate that the myosin VI immunoanalog has an important role in pinocytosis and phagocytosis in Amoeba proteus (Pal.).

scholarly journals Rab11 regulates recycling through the pericentriolar recycling endosome.

1996 ◽  
Vol 135 (4) ◽  
pp. 913-924 ◽  
Author(s):  
O Ullrich ◽  
S Reinsch ◽  
S Urbé ◽  
M Zerial ◽  
R G Parton
Keyword(s):  
Immunofluorescence Microscopy ◽  
Bound State ◽  
Small Gtpases ◽  
Recycling Endosome ◽  
Functional Studies ◽  
Confocal Immunofluorescence Microscopy ◽  
Confocal Immunofluorescence ◽  
Recycling Pathway ◽  
And Function ◽  
Perinuclear Area

Small GTPases of the rab family are crucial elements of the machinery that controls membrane traffic. In the present study, we examined the distribution and function of rab11. Rab11 was shown by confocal immunofluorescence microscopy and EM to colocalize with internalized transferrin in the pericentriolar recycling compartment of CHO and BHK cells. Expression of rab11 mutants that are preferentially in the GTP- or GDP-bound state caused opposite effects on the distribution of transferrin-containing elements; rab11-GTP expression caused accumulation of labeled elements in the perinuclear area of the cell, whereas rab11-GDP caused a dispersion of the transferrin labeling. Functional studies showed that the early steps of uptake and recycling for transferrin were not affected by overexpression of rab11 proteins. However, recycling from the later recycling endosome was inhibited in cells overexpressing the rab11-GDP mutant. Rab5, which regulates early endocytic trafficking, acted before rab11 in the transferrin-recycling pathway as expression of rab5-GTP prevented transport to the rab11-positive recycling endosome. These results suggest a novel role for rab11 in controlling traffic through the recycling endosome.

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