Selected cytotoxic gold compounds cause significant inhibition of 20S proteasome catalytic activities

2014 ◽  
Vol 141 ◽  
pp. 79-82 ◽  
Author(s):  
Nicola Micale ◽  
Tanja Schirmeister ◽  
Roberta Ettari ◽  
Maria A. Cinellu ◽  
Laura Maiore ◽  
...  
2016 ◽  
Vol 397 (9) ◽  
pp. 921-926 ◽  
Author(s):  
Wioletta Rut ◽  
Marcin Drag

Abstract The proteasome is a multicatalytic protease responsible for the degradation of misfolded proteins. We have synthesized fluorogenic substrates in which the peptide chain was systematically elongated from two to six amino acids and evaluated the effect of peptide length on all three catalytic activities of human 20S proteasome. In the cases of five- and six-membered peptides, we have also synthesized libraries of fluorogenic substrates. Kinetic analysis revealed that six-amino-acid substrates are significantly better for chymotrypsin-like and caspase-like activity than shorter peptidic substrates. In the case of trypsin-like activity, a five-amino-acid substrate was optimal.


2016 ◽  
Vol 86 (1-2) ◽  
pp. 36-47 ◽  
Author(s):  
Imen Dridi ◽  
Nidhal Soualeh ◽  
Torsten Bohn ◽  
Rachid Soulimani ◽  
Jaouad Bouayed

Abstract.This study examined whether perinatal exposure to polluted eels (Anguilla anguilla L.) induces changes in the locomotor activity of offspring mice across lifespan (post-natal days (PNDs) 47 – 329), using the open field and the home cage activity tests. Dams were exposed during gestation and lactation, through diets enriched in eels naturally contaminated with pollutants including PCBs. Analysis of the eel muscle focused on the six non-dioxin-like (NDL) indicator PCBs (Σ6 NDL-PCBs: 28, 52, 101, 138, 153 and 180). Four groups of dams (n = 10 per group) received either a standard diet without eels or eels (0.8 mg/kg/day) containing 85, 216, or 400 ng/kg/day of ϵ6 NDL-PCBs. The open field test showed that early-life exposure to polluted eels increased locomotion in female offspring of exposed dams but not in males, compared to controls. This hyperlocomotion appeared later in life, at PNDs 195 and 329 (up to 32 % increase, p < 0.05). In addition, overactivity was observed in the home cage test at PND 305: exposed offspring females showed a faster overall locomotion speed (3.6 – 4.2 cm/s) than controls (2.9 cm/s, p <0.05); again, males remained unaffected. Covered distances in the home cage test were only elevated significantly in offspring females exposed to highest PCB concentrations (3411 ± 590 cm vs. 1377 ± 114 cm, p < 0.001). These results suggest that early-life exposure to polluted eels containing dietary contaminants including PCBs caused late, persistent and gender-dependent neurobehavioral hyperactive effects in offspring mice. Furthermore, female hyperactivity was associated with a significant inhibition of acetylcholinesterase activity in the hippocampus and the prefrontal cortex.


1993 ◽  
Vol 69 (01) ◽  
pp. 021-024 ◽  
Author(s):  
Shawn Tinlin ◽  
Sandra Webster ◽  
Alan R Giles

SummaryThe development of inhibitors to factor VIII in patients with haemophilia A remains as a serious complication of replacement therapy. An apparently analogous condition has been described in a canine model of haemophilia A (Giles et al., Blood 1984; 63:451). These animals and their relatives have now been followed for 10 years. The observation that the propensity for inhibitor development was not related to the ancestral factor VIII gene has been confirmed by the demonstration of vertical transmission through three generations of the segment of the family related to a normal (non-carrier) female that was introduced for breeding purposes. Haemophilic animals unrelated to this animal have not developed functionally significant factor VIII inhibitors despite intensive factor VIII replacement. Two animals have shown occasional laboratory evidence of factor VIII inhibition but this has not been translated into clinical significant inhibition in vivo as assessed by clinical response and F.VIII recovery and survival characteristics. Substantial heterogeneity of inhibitor expression both in vitro and in vivo has been observed between animals and in individual animals over time. Spontaneous loss of inhibitors has been observed without any therapies designed to induce tolerance, etc., being instituted. There is also phenotypic evidence of polyclonality of the immune response with variable expression over time in a given animal. These observations may have relevance to the human condition both in determining the pathogenetic factors involved in this condition and in highlighting the heterogeneity of its expression which suggests the need for caution in the interpretation of the outcome of interventions designed to modulate inhibitor activity.


1997 ◽  
Vol 77 (04) ◽  
pp. 760-766 ◽  
Author(s):  
Hiroshi Mohri ◽  
Etsuko Yamazaki ◽  
Zekou Suzuki ◽  
Toshikuni Takano ◽  
Shumpei Yokota ◽  
...  

SummaryA 20-year-old man with severe von Willebrand disease recently presented a progressive bleeding tendency, characterized recurrent subcutaneous hemorrhages and cerebral hemorrhage. Mixing and infusion studies suggested the presence of an inhibitor directed against vWF:RCo activity of von Willebrand factor (vWF) without significant inhibition of the FVIII:C. The inhibitor was identified as an antibody of IgG class. The inhibitor inhibited the interaction of vWF in the presence of ristocetin and that of asialo-vWF with GPIb while it partially blocked botrocetin-mediated interaction of vWF to GPIb. The inhibitor reacted with native vWF, the 39/34kDa fragment (amino acids [aa] 480/ 481-718) and the recombinant vWF fragment (MalE-rvWF508-704), but not with Fragment III-T2 (heavy chains, aa 273-511; light chains, aa 674-728). A synthetic peptide (aa 514-542) did not inhibit vWF-inhibitor complex formation. We conclude that this is the first autoantibody of class IgG from human origin that recognizes the sequence in the A1 loop of vWF, resulting in a virtual absence of functional vWF and a concomitant severe bleeding tendency although recognition site is different from the residues 514-542 which is crucial for vWF-GPIb interaction.


1983 ◽  
Vol 50 (04) ◽  
pp. 852-856 ◽  
Author(s):  
P Gresele ◽  
C Zoja ◽  
H Deckmyn ◽  
J Arnout ◽  
J Vermylen ◽  
...  

SummaryDipyridamole possesses antithrombotic properties in the animal and in man but it does not inhibit platelet aggregation in plasma. We evaluated the effect of dipyridamole ex vivo and in vitro on platelet aggregation induced by collagen and adenosine- 5’-diphosphate (ADP) in human whole blood with an impedance aggregometer. Two hundred mg dipyridamole induced a significant inhibition of both ADP- and collagen-induced aggregation in human blood samples taken 2 hr after oral drug intake. Administration of the drug for four days, 400 mg/day, further increased the antiplatelet effect. A significant negative correlation was found between collagen-induced platelet aggregation in whole blood and dipyridamole levels in plasma (p <0.001). A statistically significant inhibition of both collagen (p <0.0025) and ADP-induced (p <0.005) platelet aggregation was also obtained by incubating whole blood in vitro for 2 min at 37° C with dipyridamole (3.9 μM). No such effects were seen in platelet-rich plasma, even after enrichment with leukocytes. Low-dose adenosine enhanced in vitro inhibition in whole blood.Our results demonstrate that dipyridamole impedes platelet aggregation in whole blood by an interaction with red blood cells, probably involving adenosine.


1979 ◽  
Author(s):  
F Albert ◽  
U Schmidt

The effect of sulfinpyrazone (200 mg three times a day) and acetylsalicylic acid (500 mg three times a day) on the incidence of thrombosis of arteriovenous shunts was investigated in a controlled clinical trial. In 36 patients with chronic renal failure scheduled to begin haemodialysis the same operating team constructed a subcutaneous fistula in the distal forearm. During the first six weeks after the operation the antithrombotic efficacy proved to be good for both substances. No differences of thrombotic events between the two treatment groups were statistically significant. But in contrast to acetylsalicylic acid sulfinpyrazone made no significant inhibition of platelet - aggregation; sulfinpyrazone probably will prevent the clot formation by prolonging the shortened platelet survival in uraemic patients. In a high rate of patients given acetylsalicylic acid (10 out of 17) there were local bleeding and gastrointestinal side effects. In consequence we should prefer sulfinpyrazone, because in the sulfinpyrazone group side effects were minimal and in none patient withdrawal from the study was necessitated.


MRS Advances ◽  
2020 ◽  
Vol 5 (61) ◽  
pp. 3141-3152
Author(s):  
Alma C. Chávez-Mejía ◽  
Génesis Villegas-Suárez ◽  
Paloma I. Zaragoza-Sánchez ◽  
Rafael Magaña-López ◽  
Julio C. Morales-Mejía ◽  
...  

AbstractSeveral photocatalysts, based on titanium dioxide, were synthesized by spark anodization techniques and anodic spark oxidation. Photocatalytic activity was determined by methylene blue oxidation and the catalytic activities of the catalysts were evaluated after 70 hours of reaction. Scanning Electron Microscopy and X Ray Diffraction analysis were used to characterize the catalysts. The photocatalyst prepared with a solution of sulfuric acid and 100 V presented the best performance in terms of oxidation of the dye (62%). The electric potential during the synthesis (10 V, low potential; 100 V, high potential) affected the surface characteristics: under low potential, catalyst presented smooth and homogeneous surfaces with spots (high TiO2 concentration) of amorphous solids; under low potential, catalyst presented porous surfaces with crystalline solids homogeneously distributed.


Author(s):  
А.А. Раецкая ◽  
С.В. Калиш ◽  
С.В. Лямина ◽  
Е.В. Малышева ◽  
О.П. Буданова ◽  
...  

Цель исследования. Доказательство гипотезы, что репрограммированные in vitro на М3 фенотип макрофаги при введении в организм будут существенно ограничивать развитие солидной карциномы in vivo . Методика. Рост солидной опухоли инициировали у мышей in vivo путем подкожной инъекции клеток карциномы Эрлиха (КЭ). Инъекцию макрофагов с нативным М0 фенотипом и с репрограммированным M3 фенотипом проводили в область формирования солидной КЭ. Репрограммирование проводили с помощью низких доз сыворотки, блокаторов факторов транскрипции STAT3/6 и SMAD3 и липополисахарида. Использовали две схемы введения макрофагов: раннее и позднее. При раннем введении макрофаги вводили на 1-е, 5-е, 10-е и 15-е сут. после инъекции клеток КЭ путем обкалывания макрофагами с четырех сторон область развития опухоли. При позднем введении, макрофаги вводили на 10-е, 15-е, 20-е и 25-е сут. Через 15 и 30 сут. после введения клеток КЭ солидную опухоль иссекали и измеряли ее объем. Эффект введения макрофагов оценивали качественно по визуальной и пальпаторной характеристикам солидной опухоли и количественно по изменению ее объема по сравнению с группой без введения макрофагов (контроль). Результаты. Установлено, что M3 макрофаги при раннем введении от начала развития опухоли оказывают выраженный антиопухолевый эффект in vivo , который был существенно более выражен, чем при позднем введении макрофагов. Заключение. Установлено, что введение репрограммированных макрофагов M3 ограничивает развитие солидной карциномы в экспериментах in vivo . Противоопухолевый эффект более выражен при раннем введении М3 макрофагов. Обнаруженные в работе факты делают перспективным разработку клинической версии биотехнологии ограничения роста опухоли, путем предварительного программирования антиопухолевого врожденного иммунного ответа «в пробирке». Aim. To verify a hypothesis that macrophages reprogrammed in vitro to the M3 phenotype and injected into the body substantially restrict the development of solid carcinoma in vivo . Methods. Growth of a solid tumor was initiated in mice in vivo with a subcutaneous injection of Ehrlich carcinoma (EC) cells. Macrophages with a native M0 phenotype or reprogrammed towards the M3 phenotype were injected into the region of developing solid EC. Reprogramming was performed using low doses of serum, STAT3/6 and SMAD3 transcription factor blockers, and lipopolysaccharide. Two schemes of macrophage administration were used: early and late. With the early administration, macrophages were injected on days 1, 5, 10, and 15 following the injection of EC cells at four sides of the tumor development area. With the late administration, macrophages were injected on days 10, 15, 20, and 25. At 15 and 30 days after the EC cell injection, the solid tumor was excised and its volume was measured. The effect of macrophage administration was assessed both qualitatively by visual and palpation characteristics of solid tumor and quantitatively by changes in the tumor volume compared with the group without the macrophage treatment. Results. M3 macrophages administered early after the onset of tumor development exerted a pronounced antitumor effect in vivo , which was significantly greater than the antitumor effect of the late administration of M3 macrophages. Conclusion. The observed significant inhibition of in vivo growth of solid carcinoma by M3 macrophages makes promising the development of a clinical version of the biotechnology for restriction of tumor growth by in vitro pre-programming of the antitumor, innate immune response.


2018 ◽  
Author(s):  
Julia Sun ◽  
Benjamin Almquist

For decades, fabrication of semiconductor devices has utilized well-established etching techniques to create complex nanostructures in silicon. Of these, two of the most common are reactive ion etching in the gaseous phase and metal-assisted chemical etching (MACE) in the liquid phase. Though these two methods are highly established and characterized, there is a surprising scarcity of reports exploring the ability of metallic films to catalytically enhance the etching of silicon in dry plasmas via a MACE-like mechanism. Here, we discuss a <u>m</u>etal-<u>a</u>ssisted <u>p</u>lasma <u>e</u>tch (MAPE) performed using patterned gold films to catalyze the etching of silicon in an SF<sub>6</sub>/O<sub>2</sub> mixed plasma, selectively increasing the rate of etching by over 1000%. The degree of enhancement as a function of Au catalyst configuration and relative oxygen feed concentration is characterized, along with the catalytic activities of other common MACE metals including Ag, Pt, and Cu. Finally, methods of controlling the etch process are briefly explored to demonstrate the potential for use as a liquid-free fabrication strategy.


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