scholarly journals A histochemical approach to the mechanism of action of cisplatin and its analogues.

1993 ◽  
Vol 41 (7) ◽  
pp. 1053-1073 ◽  
Author(s):  
S K Aggarwal
Keyword(s):  
Membrane Transport ◽  
Mechanism Of Action ◽  
Morphological Changes ◽  
Calcium Supplementation ◽  
Rat Kidney ◽  
Light And Electron Microscopy ◽  
Atp Synthesis ◽  
Chloride Ion ◽  
Tissue Homogenates ◽  
Cancer Agent

The effects of cisplatin (CDDP), a potent anti-cancer agent, and its various analogues were analyzed for any biochemical changes involving Ca2+ and lysosomal and membrane-associated transport enzymes in rat kidney, liver, serum, urine, tissue homogenates, and isolated mitochondria. Correlation was made with any morphological changes observed by light and electron microscopy to gain an insight into the mechanism of action of various platinum coordination complexes. CDDP in its hydrolyzed state under conditions of low chloride ion concentrations causes uncoupling of oxidative phosphorylation, calcium efflux from the mitochondria, inhibits ATP synthesis, lowers membrane-associated calcium and various membrane transport enzymes, and induces an increase in the number of lysosomes. Enzymes such as alkaline phosphatase are stripped from the brush borders of the proximal tubule cells and are discharged in the urine. However, daily IV injections of calcium (1.1 ml of 1.3% CaCl2) supplementation protect the membrane-associated enzymes from cisplatin action. Carboplatin (CBDCA), an analogue of CDDP and the least nephrotoxic of all its analogues, shows little effect on the membrane-associated transport enzymes. Therefore, cisplatin and its various analogues seem to affect the membrane transport enzymes to varying degrees with related nephrotoxicity. Calcium supplementation seems to protect these enzymes and preserve kidney function.

Physiological and morphological responses of the rat kidney to reduced dietary protein

1985 ◽  
Vol 248 (1) ◽  
pp. F31-F42
Author(s):  
B. Schmidt-Nielsen ◽  
J. M. Barrett ◽  
B. Graves ◽  
B. Crossley
Keyword(s):  
Dietary Protein ◽  
Morphological Changes ◽  
Rat Kidney ◽  
Light And Electron Microscopy ◽  
Protein Diet ◽  
Free Access ◽  
Vascular Bundles ◽  
Urea Clearance ◽  
Morphological Studies ◽  
Additional Group

Renal physiological and morphological adjustments to a reduced protein diet were studied in young Munich-Wistar rats. Two groups of animals were used for the correlative physiological-morphological studies: normal protein (NP, 24% dietary protein) rats and reduced protein (LP, 8% dietary protein) rats. Both groups were fed their respective diets for 4-5 wk and had free access to drinking water. Physiological measurements of GFR and urea clearance were made on five animals from each group. These data showed that the changes in renal function specifically and almost exclusively affected the handling of urea. There was no difference in GFR between the NP and LP rats. Urea clearance was substantially reduced in LP rats. Morphological analyses were made on perfusion-fixed kidneys of five animals from each group. Selected slices were examined and photographed by light and electron microscopy. These data showed no difference in size and number of elements within the vascular bundles but showed significantly smaller lumina of the thin limbs of the short-looped nephrons and a significant thinning of the wall of the thin descending limbs of the long-looped nephrons. These morphological changes may in part be responsible for the observed physiological adjustments to a reduced protein diet. An additional group of rats (6 NP and 5 LP, all dehydrated) were analyzed for distribution of solutes within the inner medulla. The data showed that the concentration of urea, but not that of Na+, was reduced at the papillary tip in LP rats.

Electron microscopic study of the membrane glycoproteins in the rat kidney after cisplatin treatment

1989 ◽  
Vol 47 ◽  
pp. 912-913
Author(s):  
S.K. Aggarwal
Keyword(s):  
Alkaline Phosphatase ◽  
Rat Kidney ◽  
Light And Electron Microscopy ◽  
Kidney Tissue ◽  
Membrane Glycoproteins ◽  
Electron Microscopic ◽  
Before And After ◽  
Interstrand Cross Links ◽  
Cross Links

The proposed primary mechanism of action of the anticancer drug cisplatin (Cis-DDP) is through its interaction with DNA, mostly through DNA intrastrand cross-links or DNA interstrand cross-links. DNA repair mechanisms can circumvent this arrest thus permitting replication and transcription to proceed. Various membrane transport enzymes have also been demonstrated to be effected by cisplatin. Glycoprotein alkaline phosphatase was looked at in the proximal tubule cells before and after cisplatin both in vivo and in vitro for its inactivation or its removal from the membrane using light and electron microscopy.Outbred male Swiss Webster (Crl: (WI) BR) rats weighing 150-250g were given ip injections of cisplatin (7mg/kg). Animals were killed on day 3 and day 5. Thick slices (20-50.um) of kidney tissue from treated and untreated animals were fixed in 1% buffered glutaraldehyde and 1% formaldehyde (0.05 M cacodylate buffer, pH 7.3) for 30 min at 4°C. Alkaline phosphatase activity and carbohydrates were demonstrated according to methods described earlier.

scholarly journals Metformin induces Ferroptosis by inhibiting UFMylation of SLC7A11 in breast cancer

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Jingjing Yang ◽  
Yulu Zhou ◽  
Shuduo Xie ◽  
Ji Wang ◽  
Zhaoqing Li ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Treatment ◽  
Morphological Changes ◽  
Tumor Model ◽  
Independent Manner ◽  
Regulated Cell Death ◽  
Anti Cancer ◽  
Cancer Agent ◽  
Approved Drugs

Abstract Background Ferroptosis is a newly defined form of regulated cell death characterized by the iron-dependent accumulation of lipid peroxidation and is involved in various pathophysiological conditions, including cancer. Targeting ferroptosis is considered to be a novel anti-cancer strategy. The identification of FDA-approved drugs as ferroptosis inducers is proposed to be a new promising approach for cancer treatment. Despite a growing body of evidence indicating the potential efficacy of the anti-diabetic metformin as an anti-cancer agent, the exact mechanism underlying this efficacy has not yet been fully elucidated. Methods The UFMylation of SLC7A11 is detected by immunoprecipitation and the expression of UFM1 and SLC7A11 in tumor tissues was detected by immunohistochemical staining. The level of ferroptosis is determined by the level of free iron, total/lipid Ros and GSH in the cells and the morphological changes of mitochondria are observed by transmission electron microscope. The mechanism in vivo was verified by in situ implantation tumor model in nude mice. Results Metformin induces ferroptosis in an AMPK-independent manner to suppress tumor growth. Mechanistically, we demonstrate that metformin increases the intracellular Fe2+ and lipid ROS levels. Specifically, metformin reduces the protein stability of SLC7A11, which is a critical ferroptosis regulator, by inhibiting its UFMylation process. Furthermore, metformin combined with sulfasalazine, the system xc− inhibitor, can work in a synergistic manner to induce ferroptosis and inhibit the proliferation of breast cancer cells. Conclusions This study is the first to demonstrate that the ability of metformin to induce ferroptosis may be a novel mechanism underlying its anti-cancer effect. In addition, we identified SLC7A11 as a new UFMylation substrate and found that targeting the UFM1/SLC7A11 pathway could be a promising cancer treatment strategy.

Morphological changes in putrefactive anaerobe 3679 (Clostridium sporogenes) induced by sorbate, hydrochloric acid, and nitrite

1989 ◽  
Vol 35 (3) ◽  
pp. 388-398 ◽  
Author(s):  
Irene E. Ronning ◽  
Hilmer A. Frank
Keyword(s):  
Cell Wall ◽  
Hydrochloric Acid ◽  
Growth Regulation ◽  
Morphological Changes ◽  
Light And Electron Microscopy ◽  
Normal Growth ◽  
Outer Wall ◽  
Exponential Growth Phase ◽  
Clostridium Sporogenes ◽  
Cellular Debris

Putrefactive anaerobe 3679 (Clostridium sporogenes), a gram-positive bacterium, was examined by light and electron microscopy during normal growth and in a medium containing sorbate (50 mM, pH 6.5), hydrochloric acid (pH of medium adjusted from 7 to 5 with HCl), or nitrite (1 mM, pH 7). During the early exponential growth phase, untreated cells were filamentous and nonseptate, but became septate later and divided when the culture entered the stationary phase. Untreated short and filamentous cells had a double-layered cell wall. Sorbate-treated cells were usually filamentous and nonseptate, but with distorted shapes characterized by numerous bends and bulges. Septation, when present, resulted in minicells. The inner cell wall appeared to be thickened and the outer wall was absent in many areas. Acid-treated cells were similar to sorbate-treated cells but contained septa. Considerable cellular debris was present in the suspension. Nitrite-treated cells were also filamentous, bent, and bulged but the cell wall appeared normal. Considerable cellular debris was also present in suspensions of nitrite-treated cells. Changes in morphology are discussed in relation to possible mechanisms of cell growth regulation and the inhibitory action of sorbate, acid, and nitrite.Key words: putrefactive anaerobe 3679, sorbate, hydrochloric acid, nitrite.

Development of a High-Content Screening Assay Panel to Accelerate Mechanism of Action Studies for Oncology Research

2012 ◽  
Vol 17 (8) ◽  
pp. 1005-1017 ◽  
Author(s):  
Danli L. Towne ◽  
Emily E. Nicholl ◽  
Kenneth M. Comess ◽  
Scott C. Galasinski ◽  
Philip J. Hajduk ◽  
...  
Keyword(s):  
Drug Discovery ◽  
Mechanism Of Action ◽  
Large Scale ◽  
Morphological Changes ◽  
Single Cells ◽  
High Content Screening ◽  
Individual Compound ◽  
Screening Assay ◽  
Oncology Research ◽  
Protein Functions

Efficient elucidation of the biological mechanism of action of novel compounds remains a major bottleneck in the drug discovery process. To address this need in the area of oncology, we report the development of a multiparametric high-content screening assay panel at the level of single cells to dramatically accelerate understanding the mechanism of action of cell growth–inhibiting compounds on a large scale. Our approach is based on measuring 10 established end points associated with mitochondrial apoptosis, cell cycle disruption, DNA damage, and cellular morphological changes in the same experiment, across three multiparametric assays. The data from all of the measurements taken together are expected to help increase our current understanding of target protein functions, constrain the list of possible targets for compounds identified using phenotypic screens, and identify off-target effects. We have also developed novel data visualization and phenotypic classification approaches for detailed interpretation of individual compound effects and navigation of large collections of multiparametric cellular responses. We expect this general approach to be valuable for drug discovery across multiple therapeutic areas.

Phenotypic change from transformed to normal induced by benzoquinonoid ansamycins accompanies inactivation of p60src in rat kidney cells infected with Rous sarcoma virus

1986 ◽  
Vol 6 (6) ◽  
pp. 2198-2206
Author(s):  
Y Uehara ◽  
M Hori ◽  
T Takeuchi ◽  
H Umezawa
Keyword(s):  
Immune Complex ◽  
Rous Sarcoma Virus ◽  
Morphological Changes ◽  
Rat Kidney ◽  
Phenotypic Change ◽  
Permissive Temperature ◽  
Rous Sarcoma ◽  
Cell Extracts ◽  
Sarcoma Virus

Three benzenoid ansamycin antibiotics (herbimycin, macbecin, and geldanamycin) were found to reduce the intracellular phosphorylation of p60src at a permissive temperature (33 degrees C) in a rat kidney cell line infected with a temperature-sensitive mutant of Rous sarcoma virus. This effect was accompanied by morphological changes from the transformed to the normal phenotype. The filamentous staining pattern of actin fibers was observed in the cells treated with these antibiotics at 33 degrees C. Removal of the antibiotics allowed the cells to revert to the transformed morphology. Ansamitocin, another benzenoid ansamycin, and naphthalenoid ansamycins such as streptovaricin and rifamycins did not show this effect. Pulse-labeling of the antibiotic-treated cultures with 32Pi showed a marked reduction of 32P radioactivity incorporated into p60src. A parallel experiment with [35S]methionine showed that synthesis of p60src was slightly inhibited. The immune complex prepared by mixing the herbimycin-treated cell extracts with antibody against p60src was inactive in vitro in phosphorylating the complex itself. On the contrary, the immune complex derived from untreated cells was active in vitro even in the presence of the antibiotics. These results suggest that benzoquinonoid ansamycins have no direct effect on src kinase but destroy its intracellular environment, resulting in an irreversible alteration of p60src and loss of catalytic activity.

Anti-amoebic Activity of Leaf Extracts and Aporphine Alkaloids Obtained from Annona purpurea

Planta Medica ◽  
2020 ◽  
Vol 86 (06) ◽  
pp. 425-433 ◽  
Author(s):  
César Díaz-Godínez ◽  
Julio C. Ontiveros-Rodríguez ◽  
Diana G. Ríos-Valencia ◽  
José Enrique Herbert-Pucheta ◽  
L. Gerardo Zepeda-Vallejo ◽  
...  
Keyword(s):  
Mechanism Of Action ◽  
Morphological Changes ◽  
Annexin V ◽  
Socioeconomically Disadvantaged ◽  
X Ray Diffraction ◽  
Leaf Extracts ◽  
1H And 13C Nmr ◽  
X Ray ◽  
Dye Reduction ◽  
First Time

Abstract Annona purpurea has been traditionally used by indigenous and socioeconomically disadvantaged people to treat infectious and parasitic diseases, including amoebiasis. The goal of this study was to assess the effect of a crude methanolic extract, an alkaloid extract, and aporphine alkaloids from leaves of A. purpurea on the viability of Entamoeba histolytica trophozoite cultures and to identify the mechanism of action. Different concentrations of the extracts and alkaloids purpureine (1), 3-hydroxyglaucine (2), norpurpureine (3) glaziovine (4), and oxopurpureine (5) were added to the cultures, and dead parasites were counted after 24 h using a tetrazolium dye reduction assay and analyzed by flow cytometry. The crude extract did not affect the viability of amoebae, but the alkaloid extract and the derived alkaloid glaziovine (4) had important anti-amoebic activity with an IC50 of 33.5 µM compared to that shown by metronidazole (6.8 µM). The treatments induced significant morphological changes in the trophozoites, and most parasites killed by the alkaloid extract were positive for Annexin V, suggesting that apoptosis was the main mechanism of action. In contrast, glaziovine (4) induced less apoptosis with more amoebic lysis. This study supports the idea that aporphine alkaloids from A. purpurea, mainly (+)-(R)-glaziovine (4), could contribute to the development of new formulations for the treatment of amoebiasis. In addition, X-ray diffraction structural analysis and complete 1H and 13C NMR assignments of (+)-(R)-glaziovine (4) were performed and reported for the first time.

scholarly journals Peroxisome development in the regenerating pars recta (P3 segment) of proximal tubules of the rat kidney.

1976 ◽  
Vol 24 (12) ◽  
pp. 1239-1248 ◽  
Author(s):  
J K Reddy ◽  
M S Rao ◽  
D E Moody ◽  
S A Qureshi
Keyword(s):  
Electron Microscopy ◽  
Rat Kidney ◽  
Light And Electron Microscopy ◽  
Proximal Tubules ◽  
Cell Multiplication ◽  
Tubular Necrosis ◽  
Mitochondrial Population ◽  
Pars Recta ◽  
Almost All ◽  
Maximum Development

The development of peroxisomes, lysosomes and endocytic vacuoles in regenerating cells of the pars recta (P3 segment) of proximal tubules, in rats given a single interperitoneal injection of d-serine (80 mg/100 g.b.wt), was studied by light and electron microscopy using cytochemical methods. Rapid proliferation of cells occurred between 2 and 5 days after d-serine induced tubular necrosis; by day 6 almost all injured tubules were re-epithelialized with flat or low cuboidal cells. Peroxisomes and lysosomes were not observed during the period of rapid cell multiplication i.e., between 2 and 6 days after d-serine injection. Restitution of mitochondrial population preceded the development of peroxisomes in the newly regenerated cells of P3 tubules. Maximum development of peroxisomes occurred between 9 and 14 days after d-serine injection. The formation of peroxisomes appeared to correlate closely with the differentiation of apical endocytic vacuoles and the brush border. Lysosomes in the regenerated cells of P3 tubules were the last to develop.

The mechanism of aspirin

2018 ◽  
Author(s):  
Pierre Sirois ◽  
Pedro D’Orléans-Juste
Keyword(s):  
Beneficial Effect ◽  
Mechanism Of Action ◽  
Inflammatory Diseases ◽  
Tissue Homogenates ◽  
Willow Tree

Aspirin has been used for the treatment of pain and inflammation for more than a hundred years; however, the medical use of what we now called aspirin dates back to antiquity, since willow-tree extracts containing salicylates were described in the Egyptian pharmacopoeia around 1543 bc. In 1971, Sir John Vane and his collaborators discovered its mechanism of action. This discovery has generated tremendous interest into the beneficial effect of this drug for the treatment of pain, inflammation, many inflammatory diseases, and even cancers. Vane and his collaborators also tested a number of other well-known aspirin-like drugs, or NSAIDs (for non-steroid anti-inflammatory drugs), and found that they all inhibited to a different extent the release of prostaglandins from organs as well as from tissue homogenates.

scholarly journals Application of ECIS to Assess FCCP-Induced Changes of MSC Micromotion and Wound Healing Migration

Sensors ◽  
2019 ◽  
Vol 19 (14) ◽  
pp. 3210 ◽  
Author(s):  
Sheng-Po Chiu ◽  
Yu-Wei Lee ◽  
Ling-Yi Wu ◽  
Tse-Hua Tung ◽  
Sofia Gomez ◽  
...  
Keyword(s):  
Time Series ◽  
Wound Healing ◽  
Cell Migration ◽  
Morphological Changes ◽  
Mitochondrial Dynamics ◽  
Human Mesenchymal Stem Cells ◽  
Atp Synthesis ◽  
Extracellular Flux ◽  
Sigmoid Curve ◽  
The Difference

Electric cell-substrate impedance sensing (ECIS) is an emerging technique for sensitively monitoring morphological changes of adherent cells in tissue culture. In this study, human mesenchymal stem cells (hMSCs) were exposed to different concentrations of carbonyl cyanide 4-(trifluoromethoxy)phenylhydrazone (FCCP) for 20 h and their subsequent concentration-dependent responses in micromotion and wound healing migration were measured by ECIS. FCCP disrupts ATP synthesis and results in a decrease in cell migration rates. To detect the change of cell micromotion in response to FCCP challenge, time-series resistances of cell-covered electrodes were monitored and the values of variance were calculated to verify the difference. While Seahorse XF-24 extracellular flux analyzer can detect the effect of FCCP at 3 μM concentration, the variance calculation of the time-series resistances measured at 4 kHz can detect the effect of FCCP at concentrations as low as 1 μM. For wound healing migration, the recovery resistance curves were fitted by sigmoid curve and the hill slope showed a concentration-dependent decline from 0.3 μM to 3 μM, indicating a decrease in cell migration rate. Moreover, dose dependent incline of the inflection points from 0.3 μM to 3 μM FCCP implied the increase of the half time for wound recovery migration. Together, our results demonstrate that partial uncoupling of mitochondrial oxidative phosphorylation reduces micromotion and wound healing migration of hMSCs. The ECIS method used in this study offers a simple and sensitive approach to investigate stem cell migration and its regulation by mitochondrial dynamics.

Sign in / Sign up

Export Citation Format

Share Document