scholarly journals α-Cyclodextrin decreases cholera toxin binding to GM1-gangliosides

2013 ◽  
Vol 62 (7) ◽  
pp. 1011-1014 ◽  
Author(s):  
Boris Ermolinsky ◽  
Michael Peredelchuk ◽  
Daniele Provenzano
Keyword(s):  
Cholera Toxin ◽  
Vibrio Cholerae ◽  
Virulence Factor ◽  
Hela Cells ◽  
Dependent Manner ◽  
Gm1 Ganglioside ◽  
Microtitre Plate ◽  
Concentration Dependent Manner ◽  
Toxin Binding ◽  
Therapeutic Properties

Cholera toxin (CT), the principal virulence factor secreted by Vibrio cholerae, is an A-B5 type exotoxin that binds to host cell GM1-gangliosides and is responsible for cholera diarrhoea. We tested the hypothesis that the cyclic hexasaccharide α-cyclodextrin (α-CD), but not the cyclic heptasaccharides methyl-β-cyclodextrin (MD-β-CD) and hydroxypropyl-β-cyclodextrin (HP-β-CD) inhibit binding of CT to GM1-gangliosides. We report that α-CD decreases CT binding to GM1-ganglioside-coated microtitre plate wells and on the surface of fixed HeLa cells in a concentration-dependent manner, suggesting that this may be a promising lead for the development of compounds with therapeutic properties.

scholarly journals Enterotoxigenicity of Mature 45-Kilodalton and Processed 35-Kilodalton Forms of Hemagglutinin Protease Purified from a Cholera Toxin Gene-Negative Vibrio cholerae Non-O1, Non-O139 Strain

2006 ◽  
Vol 74 (5) ◽  
pp. 2937-2946 ◽  
Author(s):  
A. Ghosh ◽  
D. R. Saha ◽  
K. M. Hoque ◽  
M. Asakuna ◽  
S. Yamasaki ◽  
...  
Keyword(s):  
Cholera Toxin ◽  
Vibrio Cholerae ◽  
Hela Cells ◽  
Histopathological Examination ◽  
Short Circuit ◽  
Ussing Chamber ◽  
Short Circuit Current ◽  
Toxin Gene ◽  
Dependent Manner ◽  
A Cell

ABSTRACT Cholera toxin gene-negative Vibrio cholerae non-O1, non-O139 strain PL-21 is the etiologic agent of cholera-like syndrome. Hemagglutinin protease (HAP) is one of the major secretory proteins of PL-21. The mature 45-kDa and processed 35-kDa forms of HAP were purified in the presence and absence of EDTA from culture supernatants of PL-21. Enterotoxigenicities of both forms of HAP were tested in rabbit ileal loop (RIL), Ussing chamber, and tissue culture assays. The 35-kDa HAP showed hemorrhagic fluid response in a dose-dependent manner in the RIL assay. Histopathological examination of 20 μg of purified protease-treated rabbit ileum showed the presence of erythrocytes and neutrophils in the upper part of the villous lamina propria. Treatment with 40 μg of protease resulted in gross damage of the villous epithelium with inflammation, hemorrhage, and necrosis. The 35-kDa form of HAP, when added to the lumenal surface of rat ileum loaded in an Ussing chamber, showed a decrease in the intestinal short-circuit current and a cell rounding effect on HeLa cells. The mature 45-kDa form of HAP showed an increase in intestinal short-circuit current in an Ussing chamber and a cell distending effect on HeLa cells. These results show that HAP may play a role in the pathogenesis of PL-21.

Glucose-restriction increasesTrichomonas vaginaliscellular damage towards HeLa cells and proteolytic activity of cysteine proteinases (CPs), such as TvCP2

Parasitology ◽  
2019 ◽  
Vol 146 (9) ◽  
pp. 1156-1166 ◽  
Author(s):  
Jesús F. T. Miranda-Ozuna ◽  
Luis Alberto Rivera-Rivas ◽  
Rosa Elena Cárdenas-Guerra ◽  
Mar Sarai Hernández-García ◽  
Sarahí Rodríguez-Cruz ◽  
...  
Keyword(s):  
Proteolytic Activity ◽  
Hela Cells ◽  
Trichomonas Vaginalis ◽  
Host Cells ◽  
Cellular Damage ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Cell Monolayers ◽  
Glucose Restriction ◽  
Effect Of Glucose

AbstractTrichomonas vaginalisinduces cellular damage to the host cells (cytotoxicity) through the proteolytic activity of multiple proteinases of the cysteine type (CPs). Some CPs are modulated by environmental factors such as iron, zinc, polyamines, etc. Thus, the goal of this study was to assess the effect of glucose onT. vaginaliscytotoxicity, proteolytic activity and the particular role of TvCP2 (TVAG_057000) during cellular damage. Cytotoxicity assays showed that glucose-restriction (GR) promotes the highest HeLa cell monolayers destruction (~95%) by trichomonads compared to those grown under high glucose (~44%) condition. Zymography and Western blot using different primary antibodies showed that GR increased the proteolytic activity, amount and secretion of certain CPs, including TvCP2. We further characterized the effect of glucose on TvCP2. TvCP2 increases in GR, localized in vesicles close to the plasma membrane and on the surface ofT. vaginalis. Furthermore, pretreatment of GR-trichomonads with an anti-TvCP2r polyclonal antibody specifically reduced the levels of cytotoxicity and apoptosis induction to HeLa cells in a concentration-dependent manner. In conclusion, our data show that GR, as a nutritional stress condition, promotes trichomonal cytotoxicity to the host cells, increases trichomonad proteolytic activity and amount of CPs, such as TvCP2 involved in cellular damage.

Effects of Buthus martensii Karsch Venom on Cell Proliferation and Cytotoxicity in Hela Cells

2011 ◽  
Vol 345 ◽  
pp. 393-398 ◽  
Author(s):  
Zhi Wang ◽  
Wen Hui Fu ◽  
Xiang Yang Lu ◽  
Guang Xian Cai
Keyword(s):  
Hela Cell ◽  
Hela Cells ◽  
Inhibitory Concentration ◽  
Scorpion Venom ◽  
Dependent Manner ◽  
Hela Cell Line ◽  
Rt Pcr ◽  
Concentration Dependent Manner ◽  
Significant Difference ◽  
Apoptosis And Necrosis

This paper focuses on the effect of the venom of the scorpion Buthus martensii on the proliferation of human cervical carcinoma Hela cell line and the related molecular mechanism. MTT test showed that the scorpion venom inhibited proliferation of Hela cells in time-dependent and concentration-dependent manner with 50% inhibitory concentration (IC50) of 34.5 μg/mL(48 h). By using flow cytometry, it was found that the scorpion venom could induce apoptosis and necrosis in Hela cells. RT-PCR and Western blot indicated there were obviously up-regulated in the expressions of p21 protein but the expression of p21 mRNA showed no significant difference in the Hela cell by the scorpion venom. These results suggest that the possible mechanism of the scorpion venom is to activate the expressions of p21 protein and to cause Hela cell apoptosis.

scholarly journals Differential cholera-toxin- and pertussis-toxin-catalysed ADP-ribosylation of G-proteins coupled to formyl-peptide and leukotriene B4 receptors

1993 ◽  
Vol 289 (2) ◽  
pp. 469-473 ◽  
Author(s):  
T M Schepers ◽  
K R McLeish
Keyword(s):  
Cholera Toxin ◽  
G Proteins ◽  
Pertussis Toxin ◽  
Leukotriene B4 ◽  
Guanine Nucleotides ◽  
Dependent Manner ◽  
Functional Responses ◽  
Concentration Dependent Manner ◽  
Adp Ribosylation ◽  
Formyl Peptide

N-Formylmethionyl-leucyl-phenylalanine (fMet-Leu-Phe) and leukotriene B4 (LTB4) induce disparate second-messenger generation and functional responses in neutrophils and HL-60 granulocytes. Receptors for these chemoattractants couple to a common pool of G-proteins which are substrates for both pertussis-toxin- and cholera-toxin-catalysed ADP-ribosylation. The hypothesis that formyl-peptide and LTB4 receptors induce different receptor-specific conformations of activated G-proteins was tested. The ability of pertussis toxin and cholera toxin to ADP-ribosylate G(i) proteins coupled to formyl-peptide or LTB4 receptors in membranes isolated from HL-60 granulocytes was used to assess the conformational state of the alpha subunits. Cholera-toxin-catalysed ADP-ribosylation of alpha 40 (40 kDa alpha subunit) was inhibited by guanosine 5′-[beta gamma-imido]triphosphate and GDP in a concentration-dependent manner. Addition of fMet-Leu-Phe, but not LTB4, re-established cholera-toxin labelling of alpha 40 in the presence of either guanine nucleotide. In the absence of guanine nucleotides, fMet-Leu-Phe and C5a enhanced cholera-toxin-catalysed labelling of alpha 40, whereas LTB4 and platelet-activating factor had no effect. Preincubation with fMet-Leu-Phe, but not LTB4, inhibited pertussis-toxin labelling of alpha 40 in the presence of guanosine 5′-[gamma-thio]triphosphate and in the absence of guanine nucleotides. Preincubation with fMet-Leu-Phe or LTB4 enhanced pertussis-toxin labelling of alpha 40 in the presence of GDP. These data suggest that activated G(i) proteins coupled to formyl-peptide and LTB4 receptors exist in different conformations determined by the receptor with which they interact.

scholarly journals Induction of Apoptosis in HeLa Cells by a Novel Peptide from Fruiting Bodies of Morchella importuna via the Mitochondrial Apoptotic Pathway

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Chuan Xiong ◽  
Ping Li ◽  
Qiang Luo ◽  
Chia Wei Phan ◽  
Qiang Li ◽  
...  
Keyword(s):  
Hela Cells ◽  
Gel Filtration ◽  
Dependent Manner ◽  
Fruiting Bodies ◽  
Edible Fungi ◽  
Apoptotic Pathway ◽  
Concentration Dependent Manner ◽  
Flow Cytometric ◽  
Medicinal Value ◽  
Morchella Importuna

Morels (Morchella spp.) are a genus of edible fungi with important economic and medicinal value. In this study, a novel peptide (MIPP) was extracted from the fruiting bodies of Morchella importuna using gel filtration chromatography. Structural analysis showed that the molecular mass of MIPP is 831 Da, and it has a simple amino acid sequence: Ser-Leu-Ser-Leu-Ser-Val-Ala-Arg. To explore the antitumor activity of MIPP, the effect of MIPP on HeLa cell apoptosis and the underlying preventative mechanisms were investigated. Results showed that MIPP reduced the viability of HeLa cells in a concentration-dependent manner. TUNEL analysis and flow cytometric examination showed that MIPP decreased cell proliferation via a mitochondrial-dependent pathway, as manifested by downregulation of Bcl-2/Bax, promotion of the movement of cytochrome C from the mitochondria to the cytoplasm, and triggering of caspase-9 and caspase-3. Therefore, MIPP may be a promising tumor-preventive agent, especially in human cervical cancer.

Reversal of cholera toxin-induced secretion in rat ileum by luminal berberine

1981 ◽  
Vol 241 (3) ◽  
pp. G248-G252 ◽  
Author(s):  
E. A. Swabb ◽  
Y. H. Tai ◽  
L. Jordan
Keyword(s):  
Polyethylene Glycol ◽  
Cholera Toxin ◽  
Electrolyte Transport ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Berberine Hydrochloride ◽  
Rat Ileum ◽  
Normal Water ◽  
Electrolyte Secretion

The effect of luminal berberine hydrochloride concentration on cholera toxin-induced water and electrolyte secretion and on normal water and electrolyte transport was determined in vivo in the cannulated, perfused rat ileum using [14C]polyethylene glycol as a nonabsorbable marker. Berberine reduced the cholera toxin-induced secretion of water, Na, Cl, and calculated residual ion (primarily HCO3) in a concentration-dependent manner. The effect of berberine on cholera toxin-induced ileal secretion was evident 60-80 min after exposure and was reversed 60–80 min after removal of berberine from the perfusate. Mild changes in mucosal histology (villous tip edema) due to cholera toxin were also reversed by berberine. Berberine did not significantly alter normal ileal water and electrolyte transport.

scholarly journals Antioxidant Activity, Antitumor Effect, and Antiaging Property of Proanthocyanidins Extracted fromKunlun ChrysanthemumFlowers

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Siqun Jing ◽  
Xiaoming Zhang ◽  
Liang-Jun Yan
Keyword(s):  
Antioxidant Activity ◽  
Hela Cells ◽  
Antitumor Effect ◽  
Vero Cells ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Total Antioxidant ◽  
Aging Property

The objective of the present study was to evaluate the antioxidant activity, antitumor effect, and antiaging property of proanthocyanidins fromKunlun Chrysanthemumflowers (PKCF) grown in Xinjiang. In vitro antioxidant experiments results showed that the total antioxidant activity and the scavenging capacity of hydroxyl radicals (•OH) and 1,1-diphenyl-2-picrylhydrazyl (DPPH•) radicals increased in a concentration-dependent manner and were stronger than those of vitamin C. To investigate the antioxidant activity of PKCF in vivo, we used serum, liver, and kidney from mouse for the measurement of superoxide dismutase (SOD), malondialdehyde (MDA), and total antioxidant capacity (T-AOC). Results indicated that PKCF had antioxidative effect in vivo which significantly improved the activity of SOD and T-AOC and decreased MDA content. To investigate the antitumor activity of PKCF, we used H22 cells, HeLa cells, and Eca-109 cells with Vero cells as control. Inhibition ratio and IC50values were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay; PKCF showed great inhibitory activity on H22 cells and HeLa cells. We also used fruit flies as a model for analyzing the anti-aging property of PKCF. Results showed that PKCF has antiaging effect onDrosophila. Results of the present study demonstrated that PKCF could be a promising agent that may find applications in health care, medicine, and cosmetics.

scholarly journals Cytotoxic potential of camel whey and milk on cervix cancer (HeLa) cell line

2019 ◽  
Vol 5 (3) ◽  
pp. 231-236
Author(s):  
Lubna A Abdallah ◽  
Ashraf M Sawafta ◽  
Sanad A Ben Ali ◽  
Hasan A Baradia
Keyword(s):  
Hela Cells ◽  
Culture Technique ◽  
Cervix Cancer ◽  
Camel Milk ◽  
Dependent Manner ◽  
Anticancer Effect ◽  
Concentration Dependent Manner ◽  
Diphenyltetrazolium Bromide ◽  
Vitro Effect

Camel milk is an important nutritional source that historically been used in the treatment of cancer. Therefore, the main aim of the present study is to determine the in vitro anticancer effect of both camel milk and whey against cervix cancer (HeLa) cells. To perform that, skimmed milk as well as whey immunoglobulins concentrate samples were prepared at different concentrations (0, 1, 2.5, 5, 7.5 and 10 mg/ml). Then, the in vitro effect of the prepared concentrations on HeLa cells morphology and growth was investigated by tissue culture technique. Moreover, the anticancer activity of camel milk and whey against HeLa cells was estimated by the 3-[4, 5-dimethylthiazole-2-yl]-2, 5-diphenyltetrazolium bromide (MTT) assay. The obtained results displayed that both camel milk and whey reduced the viability of HeLa cells specially at 7.5 and 10 mg/ml. In addition, the viability of treated HeLa cells reduced after addition of both camel milk and whey to approximately 15% in a concentration dependent manner. In conclusion, this study showed the in vitro cytotoxic effect of camel milk and whey as they inhibited the growth of HeLa cells. Asian J. Med. Biol. Res. June 2019, 5(3): 231-236

scholarly journals Ethyl Acetate Fraction of Caesalpinia sappan L. Enhances Cisplatin’s Cytotoxicity on HeLa Cells via G1 and S Arrest through p53 Expression

2017 ◽  
Vol 8 (2) ◽  
pp. 51 ◽  
Author(s):  
Ulfatul Husnaa ◽  
Ni Putu Linda Laksmiani ◽  
Ratna Asmah Susidarti ◽  
Edy Meiyanto
Keyword(s):  
Cell Cycle ◽  
Ethyl Acetate ◽  
Cytotoxic Activity ◽  
Hela Cells ◽  
Morphological Changes ◽  
Ethyl Acetate Fraction ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
P53 Expression ◽  
Cycle Arrest

Cisplatin (cisp) is the first line chemotherapeutic agent for several cancer diseases which can cause significant side effects and cellular resistance. Combination-chemotherapy treatment (co-chemotherapy) was reported to be able to reduce cisp effects. Therefore, this study was carried out to investigate the cytotoxic activity of ethyl acetate fraction of C. sappan (EFC) in combination with cisp by observing apoptosis induction and cell cycle profile. Cytotoxic activity was evaluated by MTT assay. Cell cycle and apoptosis analysis were performed using flow cytometry and p53 expression was analyzed using immunocytochemistry. EFC performed cytotoxic effect on HeLa cells by showing morphological changes such as cell shrinkage, rounding and decreasing of cells viability in concentration dependent manner, giving IC50 value of 65 μg/mL. Combination of EFC and cisp in low concentration decreased cell viability into 36.86%. Further assay indicated that this combination caused redistribution of cell cycle arrest in G1 and S phases through p53 stabilization in nucleus. However, that mechanism was not followed by apoptosis. These results provide evidence to support EFC development as the enhancer of cisp effect, by improving its cytotoxicity on HeLa cells. EFC increases HeLa cells sensitivity to cisp through G1 and S cells’ arrest depending on p53 expression. Key words: co-chemotherapy, EFC, cervix cancer HeLa cells, p53, G1 and S arrest.         

Prevention of alpha 2-adrenergic inhibition on ADH action by pertussis toxin in rabbit CCT

1987 ◽  
Vol 253 (1) ◽  
pp. C105-C112 ◽  
Author(s):  
C. P. Ribeiro ◽  
F. Ribeiro-Neto ◽  
J. B. Field ◽  
W. N. Suki
Keyword(s):  
Cholera Toxin ◽  
Pertussis Toxin ◽  
Regulatory Protein ◽  
Receptor Occupancy ◽  
Covalent Modification ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Water Permeability Coefficient ◽  
Previously Treated ◽  
Collecting Tubules

The present studies were performed to investigate the mechanism whereby alpha 2-adrenergic receptor occupancy inhibits the hydrosmotic action of antidiuretic hormone (ADH) in isolated cortical collecting tubules (CCT). The ADH-ribosyltransferase activity of pertussis toxin (PT) was used to promote covalent modification in CCT Ni, the inhibitory regulatory protein of adenylate cyclase, which presumably mediates the alpha 2-adrenergic inhibition of water flow. Tubules preincubated with PT were studied after the addition of ADH and then after the superimposition of clonidine. In these studies, the inhibition of Jv (water absorption, nl X mm-1 X min-1) and Pf (water permeability coefficient, cm/s), by the addition of 10(-4) M clonidine to the bath, was attenuated by PT in a concentration-dependent manner. Reversal of the inhibitory action of clonidine was accomplished with a concentration of 1.0 micrograms/ml PT. To further elucidate the molecular basis of Ni-mediated transduction of the alpha 2-adrenergic signal, ADP-ribosylation studies were undertaken in membrane preparations of dissected CCT segments. PT ADP ribosylated a 40,000 Mr peptide which was proportional to the amount of membrane protein added. Furthermore, pretreatment of CCT during dissection with 0.5 micrograms/ml PT dramatically decreased the susceptibility of the subunit of Ni (alpha i) to be subsequently ADP ribosylated by PT, when compared with CCT preparations not previously treated with PT. Cholera toxin ADP ribosylated a 42,000 Mr peptide from CCT membranes and PT pretreatment did not interfere with the reaction. We conclude that CCT segments have both the pertussis and cholera toxin substrates and the effect of clonidine to attenuate ADH action is mediated through Ni.

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