Superoxide dismutase C affects Dictyostelium contractile vacuole biogenesis and function

2020 ◽  
Vol 62 (9) ◽  
pp. 516-526
Author(s):  
Adwait Kabra ◽  
Lou W. Kim
Keyword(s):  
Superoxide Dismutase ◽  
Contractile Vacuole ◽  
And Function ◽  
Vacuole Biogenesis

scholarly journals Inactive extracellular superoxide dismutase disrupts secretion and function of active extracellular superoxide dismutase

BMB Reports ◽  
2011 ◽  
Vol 44 (1) ◽  
pp. 40-45 ◽  
Author(s):  
Byeong-Wook Jeon ◽  
Byung-Hak Kim ◽  
Yun-Sang Lee ◽  
Sung-Sub Kim ◽  
Jong-Bok Yoon ◽  
...  
Keyword(s):  
Superoxide Dismutase ◽  
Extracellular Superoxide Dismutase ◽  
And Function

scholarly journals Erythropoietin Increases Expression and Function of Vascular Copper- and Zinc-Containing Superoxide Dismutase

Hypertension ◽  
2010 ◽  
Vol 55 (4) ◽  
pp. 998-1004 ◽  
Author(s):  
Livius V. d'Uscio ◽  
Leslie A. Smith ◽  
Zvonimir S. Katusic
Keyword(s):  
Superoxide Dismutase ◽  
Copper And Zinc ◽  
And Function

scholarly journals Rab11-like GTPase associates with and regulates the structure and function of the contractile vacuole system in Dictyostelium

2001 ◽  
Vol 114 (16) ◽  
pp. 3035-3045 ◽  
Author(s):  
Edward Harris ◽  
Kunito Yoshida ◽  
James Cardelli ◽  
John Bush
Keyword(s):  
Proton Pump ◽  
Membrane Trafficking ◽  
Amino Acid Level ◽  
Fluid Phase ◽  
Membrane System ◽  
Structure And Function ◽  
Dominant Negative ◽  
Contractile Vacuole ◽  
And Function ◽  
Mutant Cells

Screening of a cDNA library revealed the existence of a Dictyostelium cDNA encoding a protein 80% identical at the amino acid level to mammalian Rab11. Subcellular fractionation and immunofluorescence studies revealed that DdRab11 was exclusively associated with the ATPase proton pump-rich contractile vacuole membrane system, consisting of a reticular network and bladder-like vacuoles. Video microscopy of cells expressing GFP-DdRab11 revealed that this Rab was associated with contractile vacuolar bladders undergoing formation, fusion and expulsion of water. The association of DdRab11 with contractile vacuole membranes was disrupted when cells were exposed to either hypo-osmotic conditions or an inhibitor of the ATPase proton pump. Cells that overexpressed a dominant negative form of DdRab11 were analyzed biochemically and microscopically to measure changes in the structure and function of the contractile vacuole system. Compared with wild-type cells, the dominant negative DdRab11-expressing cells contained a more extensive contractile vacuole network and abnormally enlarged contractile vacuole bladders, most likely the result of defects in membrane trafficking. In addition, the mutant cells enlarged, detached from surfaces and contained large vacuoles when exposed to water, suggesting a functional defect in osmotic regulation. No changes were observed in mutant cells in the rate of fluid phase internalization or release, suggesting the DdRab11-mediated membrane trafficking defects were not general in nature. Surprisingly, the rate of phagocytosis was increased in the dominant negative DdRab11-expressing cells when compared with control cells. Our results are consistent with a role for DdRab11 in regulating membrane traffic to maintain the normal morphology and function of the contractile vacuole.

scholarly journals Involvement of the vacuolar proton-translocating ATPase in multiple steps of the endo-lysosomal system and in the contractile vacuole system of Dictyostelium discoideum

1996 ◽  
Vol 109 (6) ◽  
pp. 1479-1495 ◽  
Author(s):  
L.A. Temesvari ◽  
J.M. Rodriguez-Paris ◽  
J.M. Bush ◽  
L. Zhang ◽  
J.A. Cardelli
Keyword(s):  
Morphological Changes ◽  
Specific Inhibitor ◽  
Fluid Phase ◽  
Contractile Vacuole ◽  
Dependent Manner ◽  
Concanamycin A ◽  
Latex Beads ◽  
And Function

We have investigated the effects of Concanamycin A (CMA), a specific inhibitor of vacuolar type H(+)-ATPases, on acidification and function of the endo-lysosomal and contractile vacuole (CV) systems of D. discoideum. This drug inhibited acidification and increased the pH of endo-lysosomal vesicles both in vivo and in vitro in a dose dependent manner. Treatment also inhibited endocytosis and exocytosis of fluid phase, and phagocytosis of latex beads. This report also confirms our previous conclusions (Cardelli et al. (1989) J. Biol. Chem. 264, 3454–3463) that maintenance of acidic pH in lumenal compartments is required for efficient processing and targeting of a lysosomal enzyme, alpha-mannosidase. CMA treatment compromised the function of the contractile vacuole complex as amoebae exposed to a hypo-osmotic environment in the presence of CMA, swelled rapidly and ruptured. Fluorescence microscopy revealed that CMA treatment induced gross morphological changes in D. discoideum cells, characterized by the formation of large intracellular vacuoles containing fluid phase. The reticular membranes of the CV system were also no longer as apparent in drug treated cells. Finally, this is the first report describing cells that can adapt in the presence of CMA; in nutrient medium, D. discoideum overcame the effects of CMA after one hour of drug treatment even in the absence of protein synthesis. Upon adaptation to CMA, normal sized endo-lysosomal vesicles reappeared, endo-lysosomal pH decreased, and the rate of endocytosis, exocytosis and phagocytosis returned to normal. This study demonstrates that the V-H(+)-ATPase plays an important role in maintaining the integrity and function of the endo-lysosomal and CV systems and that D. discoideum can compensate for the loss of a functional V-H(+)-ATPase.

scholarly journals Serum Superoxide Dismutase Is Associated with Vascular Structure and Function in Hypertensive and Diabetic Patients

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Manuel A. Gómez-Marcos ◽  
Ana M. Blázquez-Medela ◽  
Luis Gamella-Pozuelo ◽  
José I. Recio-Rodriguez ◽  
Luis García-Ortiz ◽  
...  
Keyword(s):  
Superoxide Dismutase ◽  
Vascular Function ◽  
Augmentation Index ◽  
Serum Levels ◽  
Structure And Function ◽  
Stiffness Index ◽  
Diabetic Patients ◽  
Vascular Structure ◽  
Arterial Stiffness Index ◽  
And Function

Oxidative stress is associated with cardiac and vascular defects leading to hypertension and atherosclerosis, being superoxide dismutase (SOD) one of the main intracellular antioxidant defence mechanisms. Although several parameters of vascular function and structure have a predictive value for cardiovascular morbidity-mortality in hypertensive patients, there are no studies on the involvement of SOD serum levels with these vascular parameters. Thus, we assessed if SOD serum levels are correlated with parameters of vascular function and structure and with cardiovascular risk in hypertensive and type 2 diabetic patients. We enrolled 255 consecutive hypertensive and diabetic patients and 52 nondiabetic and nonhypertensive controls. SOD levels were measured with an enzyme-linked immunosorbent assay kit. Vascular function and structure were evaluated by pulse wave velocity, augmentation index, ambulatory arterial stiffness index, and carotid intima-media thickness. We detected negative correlations between SOD and pressure wave velocity, peripheral and central augmentation index and ambulatory arterial stiffness index, pulse pressure, and plasma HDL-cholesterol, as well as positive correlations between SOD and plasma uric acid and triglycerides. Our study shows that SOD is a marker of cardiovascular alterations in hypertensive and diabetic patients, since changes in its serum levels are correlated with alterations in vascular structure and function.

scholarly journals Antioxidant radiation response of rat brain after exposure to a clinical dose of γ-rays

2005 ◽  
Vol 57 (4) ◽  
pp. 273-275
Author(s):  
Ana Todorovic ◽  
Jelena Kasapovic ◽  
Snezana Pejic ◽  
Vesna Stojiljkovic ◽  
Snezana Pajovic
Keyword(s):  
Superoxide Dismutase ◽  
Cell Structure ◽  
Brain Regions ◽  
Dependent Manner ◽  
Clinical Dose ◽  
Mitochondrial Superoxide ◽  
Γ Rays ◽  
And Function ◽  
The Brain ◽  
Mitochondrial Superoxide Dismutase

Ionizing radiation increases intracellular production of reactive oxygen species (ros), which can damage cell structure and function. The brain is particularly vulnerable to oxidative injury, and in an area-dependent manner. In order to elucidate differences in enzymatic antioxidative responses of the rat hippocampus and cortex, we measured the activities of cytosol superoxide dismutase (CuZnSOD), mitochondrial superoxide dismutase (MnSOD), and catalase (CAT) in those two brain regions, isolated 1 h and 24 h after exposure to 2 Gy of ?-rays. Our results indicate that the lower MnSOD activity and inducibility found in the hippocampus are probably among the main reasons for particularly great oxidative vulnerability of this brain region.

scholarly journals A role for a Rab4-like GTPase in endocytosis and in regulation of contractile vacuole structure and function in Dictyostelium discoideum.

1996 ◽  
Vol 7 (10) ◽  
pp. 1623-1638 ◽  
Author(s):  
J Bush ◽  
L Temesvari ◽  
J Rodriguez-Paris ◽  
G Buczynski ◽  
J Cardelli
Keyword(s):  
Dictyostelium Discoideum ◽  
Cell Lines ◽  
Structure And Function ◽  
Dominant Negative ◽  
Contractile Vacuole ◽  
Vacuole Membrane ◽  
Endosomal Pathway ◽  
Transformed Cell Lines ◽  
And Function ◽  
Mutant Cells

The small Mr Rab4-like GTPase, RabD, localizes to the endosomal pathway and the contractile vacuole membrane system in Dictyostelium discoideum. Stably transformed cell lines overexpressing a dominant negative functioning RabD internalized fluid phase marker at 50% of the rate of wild-type cells. Mutant cells were also slower at recycling internalized fluid. Microscopic and biochemical approaches indicated that the transport of fluid to large postlysosome vacuoles was delayed in mutant cells, resulting in an accumulation in acidic smaller vesicles, probably lysosomes. Also, RabD N121I-expressing cell lines missorted a small but significant percentage of newly synthesized lysosomal alpha-mannosidase precursor polypeptides. However, the majority of the newly synthesized alpha-mannosidase was transported with normal kinetics and correctly delivered to lysosomes. Subcellular fractionation and immunofluorescent microscopy indicated that in mutant cells contractile vacuole membrane proteins were associated with compartments morphologically distinct from the normal reticular network. Osmotic tests revealed that the contractile vacuole functioned inefficiently in mutant cells. Our results suggest that RabD regulates membrane traffic along the endosomal pathway, and that this GTPase may play a role in regulating the structure and function of the contractile vacuole system by facilitating communication with the endosomal pathway.

scholarly journals Extracellular Superoxide Dismutase Enhances Recruitment of Immature Neutrophils to the Liver

2016 ◽  
Vol 84 (12) ◽  
pp. 3302-3312 ◽  
Author(s):  
Timothy J. Break ◽  
Alexandra R. Witter ◽  
Mohanalaxmi Indramohan ◽  
Mark E. Mummert ◽  
Ladislav Dory ◽  
...  
Keyword(s):  
Superoxide Dismutase ◽  
Neutrophil Recruitment ◽  
Innate Immune ◽  
Intracellular Pathogen ◽  
Extracellular Superoxide Dismutase ◽  
Oxygen Species ◽  
Content Type ◽  
A Cell ◽  
And Function ◽  
The Impact

Listeria monocytogenesis a Gram-positive intracellular pathogen that causes spontaneous abortion in pregnant women, as well as septicemia, meningitis, and gastroenteritis, primarily in immunocompromised individuals. AlthoughL. monocytogenescan usually be effectively treated with antibiotics, there is still around a 25% mortality rate with individuals who develop clinical listeriosis. Neutrophils are innate immune cells required for the clearance of pathogenic organisms, includingL. monocytogenes. The diverse roles of neutrophils during both infectious and noninfectious inflammation have recently gained much attention. However, the impact of reactive oxygen species, and the enzymes that control their production, on neutrophil recruitment and function is not well understood. Using congenic mice with varying levels of extracellular superoxide dismutase (ecSOD) activity, we have recently shown that the presence of ecSOD decreases clearance ofL. monocytogeneswhile increasing the recruitment of neutrophils that are not protective in the liver. The data presented here show that ecSOD activity does not lead to a cell-intrinsic increase in neutrophil-homing potential or a decrease in protection againstL. monocytogenes. Instead, ecSOD activity enhances the production of neutrophil-attracting factors and protects hyaluronic acid (HA) from damage. Furthermore, neutrophils from the livers of ecSOD-expressing mice have decreased intracellular and surface-bound myeloperoxidase, are less capable of killing phagocytosedL. monocytogenes, and have decreased oxidative burst. Collectively, our data reveal that ecSOD activity modulates neutrophil recruitment and function in a cell-extrinsic fashion, highlighting the importance of the enzyme in protecting tissues from oxidative damage.

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