scholarly journals ANTAGONISTIC EFFECTS OF 6-MERCAPTOPURINE AND COENZYME A ON MITOCHONDRIA AND MITOSIS IN TISSUE CULTURE

1955 ◽  
Vol 1 (2) ◽  
pp. 119-126 ◽  
Author(s):  
John J. Biesele

The partial mitotic inhibition caused by 6-mercaptopurine in tissue cultures of Crocker mouse sarcoma 180 and embryonic mouse skin is blocked by co-enzyme A. 6-Mercaptopurine and coenzyme A also have opposite effects on mitochondrial morphology. Mitochondria in cells treated with 6-mercaptopurine become thin and fragmented. Coenzyme A blocks this effect, and alone coenzyme A makes for longer and thicker mitochondria. 6-Mercaptopurine inhibits lipogenesis in embryo skin fibroblasts, and this inhibition is partly counteracted by coenzyme A, which by itself makes for a greater accumulation of lipid droplets in the cytoplasm. It is suggested that at least one part of the action by which 6-mercaptopurine decreases mitotic incidence in tissue cultures may be an interference on the part of 6-mercaptopurine, acting as an antimetabolite of coenzyme A, in mitochondrial function related to cell division.

2019 ◽  
Author(s):  
Kaylee Steen ◽  
Desu Chen ◽  
Fengrong Wang ◽  
Song Chen ◽  
Surinder Kumar ◽  
...  

AbstractMitochondria fulfill essential roles in ATP production, metabolic regulation, calcium signaling, generation of reactive oxygen species (ROS) and additional determinants of cellular health. Recent studies have highlighted a role for mitochondria during cell differentiation, including in skin epidermis. The observation of oxidative stress in keratinocytes from Krt16 null mouse skin, a model for pachyonychia congenita (PC)-associated palmoplantar keratoderma, prompted us to examine the role of Keratin (K) 16 protein and its partner K6 in regulating the structure and function of mitochondria. Electron microscopy revealed major anomalies in mitochondrial ultrastructure in late stage, E18.5, Krt6a/Krt6b null embryonic mouse skin. Follow-up studies utilizing biochemical, metabolic, and live imaging readouts showed that, relative to controls, skin keratinocytes null for Krt6a/Krt6b or Krt16 exhibit elevated ROS, reduced mitochondrial respiration, intracellular distribution differences and altered movement of mitochondria within the cell. These findings highlight a novel role for K6 and K16 in regulating mitochondrial morphology, dynamics and function and shed new light on the causes of oxidative stress observed in PC and related keratin-based skin disorders.


Metabolites ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 322
Author(s):  
Jae-Eun Song ◽  
Tiago C. Alves ◽  
Bernardo Stutz ◽  
Matija Šestan-Peša ◽  
Nicole Kilian ◽  
...  

In the presence of high abundance of exogenous fatty acids, cells either store fatty acids in lipid droplets or oxidize them in mitochondria. In this study, we aimed to explore a novel and direct role of mitochondrial fission in lipid homeostasis in HeLa cells. We observed the association between mitochondrial morphology and lipid droplet accumulation in response to high exogenous fatty acids. We inhibited mitochondrial fission by silencing dynamin-related protein 1(DRP1) and observed the shift in fatty acid storage-usage balance. Inhibition of mitochondrial fission resulted in an increase in fatty acid content of lipid droplets and a decrease in mitochondrial fatty acid oxidation. Next, we overexpressed carnitine palmitoyltransferase-1 (CPT1), a key mitochondrial protein in fatty acid oxidation, to further examine the relationship between mitochondrial fatty acid usage and mitochondrial morphology. Mitochondrial fission plays a role in distributing exogenous fatty acids. CPT1A controlled the respiratory rate of mitochondrial fatty acid oxidation but did not cause a shift in the distribution of fatty acids between mitochondria and lipid droplets. Our data reveals a novel function for mitochondrial fission in balancing exogenous fatty acids between usage and storage, assigning a role for mitochondrial dynamics in control of intracellular fuel utilization and partitioning.


1986 ◽  
Vol 81 (2) ◽  
pp. 225-232 ◽  
Author(s):  
Marilda M. Siqueira ◽  
Vanja Ferreira ◽  
Jussara P. Nascimento

Two techniques for rapid diagnosis, immunofluorescence (IFAT) and enzyme immunoassay (EIA), have been compared with virus isolaion in tissue culture for the detection of respiratory syncytial virus (RSV) in specimens of nasopharyngeal secretions. The specimens were obtained from children under five years of age suffering from acute respiratory iliness, during a period of six months from January to June 1982. Of 471 specimens examined 54 (11.5%) were positive by virus isolation and 180 (38.2%) were positive by immunofluorescence. The bacterial contamination of inoculated tissue cultures unfortunately prevented the isolation of virus from many samples. Specimens from 216 children were tested to compare enzyme immunoassay and immunofluorescence. Of these 60 (27%) were positive by EIA and 121 (56%) were positive by IFAT. Our results suggest that the EIA technique although highly specific is rather insensitive. This may be because by the time these tests were done the originl nasopharyngeal secretions were considerably diluted and contained more mucus fragments than the call suspension used for IFAT. Of the three techniques, IFAT gives the best results although EIA may be useful where IFAT is not possible.


2016 ◽  
Vol 67 (3) ◽  
pp. 204-209 ◽  
Author(s):  
Nursel Gül ◽  
Nuri Yiğit ◽  
Fulya Saygılı ◽  
Ebru Demirel ◽  
Ceren Geniş

Abstract We used transmission electron microscopy to examine the cytotoxic effects of the second-generation anticoagulant rodenticides difenacoum and brodifacoum on rat liver. A single dose of difenacoum or brodifacoum was administered to rats by gastric gavage and liver samples were taken after 24 h, four days or seven days. In the livers of rats treated with difenacoum for 24 h, hepatocytes typically showed increased numbers of lysosomes, as well as enlargement of both the perinuclear space and the cisternae of the rough endoplasmic reticulum (RER), while sinusoids were irregularly shaped and contained Kupffer cells. Similar irregularities occurred in brodifacoum-treated rats at the same time point, but additionally increased numbers of vacuoles, damaged mitochondrial cristae, and clumping of chromatin were observed in hepatocytes, and hemolysed erythrocytes were noted in the sinusoids. Comparable findings were made in each group of rats after four days. After seven days of difenacoum treatment, hepatocytes suffered loss of cytoplasmic material and mitochondrial shrinkage, while RER cisternae became discontinuous. In contrast, exposure to brodifacoum for seven days caused the formation of numerous vacuoles and lipid droplets, disordered mitochondrial morphology, chromatin clumping and invagination of the nuclear envelope in hepatocytes. Sinusoids in the livers of rodenticide-treated rats contained an accumulation of dense material, lipid droplets, cells with pycnotic nuclei and hemolysed erythrocytes. Overall, our results show that brodifacoum causes more severe effects in liver cells than difenacoum. Thus our microscopic data along with additional biochemical assays point to a severe effect of rodenticide on vertebrates.


Oncology ◽  
1964 ◽  
Vol 17 (1) ◽  
pp. 1-6
Author(s):  
P. Tomashefsky ◽  
S. Baum ◽  
C. Funk

The application of the micromanipulative technique to the study of cells in tissue culture has for a long time offered an interesting, though difficult, field of research. Thus far, comparatively little has been done, the most notable contributions being those of Levi and of Peterfi and co-workers (Levi, 1926 ; Peterfi and Olivo, 1925 ; Peterfi, 1927 ; Peterfi and Kapel, 1928). Peterfi has also written a special paper on the technique (1927). The main deterrent in this work has been the lack of sufficient ease in the accurate and continuous control of the microneedles under the conditions required.


2018 ◽  
Vol 57 (2) ◽  
Author(s):  
Eric Gomez-Urena ◽  
Rafael J. Sierra ◽  
Kerryl E. Greenwood-Quiantance ◽  
Melissa J. Karau ◽  
James M. Steckelberg ◽  
...  

ABSTRACT Diagnosis of persistent infection at the time of reimplantation for staged revision of infected arthroplasties is challenging. Implant sonication culture for the diagnosis of prosthetic joint infection (PJI) has improved sensitivity compared to standard periprosthetic tissue culture. We report our experience with periprosthetic tissue culture and sonication culture of antimicrobial agent-containing cement spacers (ACSs) collected during second stages of staged revisions for arthroplasty infection. We studied 87 ACSs from 66 patients undergoing two-stage revision arthroplasty for PJI submitted for sonication culture, along with conventional periprosthetic tissue cultures. Two or more positive periprosthetic tissue cultures with the same organism were considered a positive tissue culture. For sonication culture, ≥20 CFU of bacteria per 10 ml of sonicate fluid was considered positive. The sensitivity and specificity of periprosthetic tissue and ACS sonication culture in detecting persistent infection, as well as their association with outcome, were assessed. Persistent infection occurred in 26% of cases. Periprosthetic tissue and sonicate fluid culture had specificities of 96.3 and 100% (P = 0.50), respectively, and sensitivities of 31.6 and 26.3% (P = 1.00), respectively, for the diagnosis of persistent infection. Thirteen subjects deemed not to have persistent infection at time of reimplantation and who had negative periprosthetic tissue and sonicate fluid cultures subsequently developed overt infection. Sonication culture of cement spacers identifies a similar proportion of patients with persistent infection during staged revisions, as detected by periprosthetic tissue cultures; both have low sensitivities to detect persistent infection.


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