Destruction Of Mitochondrial Membranes Research Articles

МОРФОЛОГИЧЕСКИЕ И УЛЬТРАСТРУКТУРНЫЕ ИЗМЕНЕНИЯ ТКАНИ ПЕЧЕНИ ПРИ БИЛИАРНОЙ ОККЛЮЗИИ РАЗЛИЧНОЙ ДЛИТЕЛЬНОСТИ

An analysis of the morphological state of the liver was carried out in 160 patients with obstructive jaundice of non-tumor etiology who received treatment in the Novgorod Regional Clinical Hospital and Central City Clinical Hospital. The results of liver biopsy during surgery were studied. Pronounced structural and functional changes in liver tissue were revealed, which were further aggravated due to an increase in the duration of occlusion. In cases with long-term chronic jaundice, after decompression of the bile ducts, sclerotic changes, histiolymphocytic infiltration and proliferating biliary epithelium, fibrosis and foci of hepatocyte necrosis remain in the portal tracts. Ultrastructure analysis revealed changes in the cell membrane, cytoplasmic structures, destruction of mitochondrial membranes, formation of secondary lysosomes, disruption of the integrity of the nuclear membrane and signs of karyolysis. The study of puncture and surgical biopsies for obstructive jaundice makes it possible to establish the form and severity of cholestasis and, along with other diagnostic indicators, affects disease prognosis and the tactics of surgical treatment. Taking the different timing and severity of cholestasis into account, it is necessary to use therapeutic technologies in advance that lead to an improvement in liver morphology.

Multi-walled carbon nanotube induced liver injuries possibly by promoting endoplasmic reticulum stress in Cyprinus carpio

The mass production and discharge of carbon nanotubes (CNTs) to the water environment are of great concern since they threaten the health of organisms in the aquatic ecosystem. CNTs induce multi-organ injuries in fish, but limited literature is available regarding the mechanisms involved. In the present study, juvenile common carp (Cyprinus carpio) were exposed to multi-walled carbon nanotubes (MWCNTs) (0.25 mg L−1 and 2.5 mg L−1) for four weeks. MWCNTs caused dose-dependent alterations in the pathological morphology of liver tissues. Ultrastructural changes manifested as nuclear deformation, chromatin condensation, endoplasmic reticulum (ER) disorderly arrangement, mitochondria vacuolation, and mitochondrial membrane destruction. TUNEL analysis indicated that the apoptosis rate in hepatocytes markedly increased upon exposure to MWCNTs. Moreover, the apoptosis was confirmed by significant upregulation of mRNA levels of apoptosis-related genes (Bcl-2, XBP1, Bax, and caspase3) in MWCNTs-exposure groups, except for Bcl-2 expression which was not significantly changed in HSC groups (2.5 mg L−1 MWCNTs). Furthermore, real-time PCR assay indicated the increased expression of ER stress (ERS) marker genes (GRP78, PERK, and eIF2α) in the exposure groups compared to the control groups, suggesting that the PERK/eIF2α signaling pathway involved in the injuries of the liver tissue. Overall, the results above indicate that MWCNTs induce ERS by activating the PERK/eIF2α pathway in the liver of common carp, and resulted in the initiation of apoptosis procedure.

Influence of Green Synthesized Zinc Oxide Nanoparticles on Molecular Interaction and Comparative Binding of Azure Dye with Chymotrypsin: Novel Nano-Conjugate for Cancer Phototherapy.

Till date, different types of conventional drugs have been used to fight tumors. However, they have significant flaws, including their usage being constrained because of their low bioavailability, poor supply, and serious side effects. The modern combination therapy has been viewed as a potent strategy for treating serious illnesses, including cancer-type feared diseases. The nanoparticles are a promising choice for cancer therapeutic and diagnostic applications because of their fascinating optoelectronic and physicochemical features. Among the metallic nanoparticles, Zinc oxide nanoparticles possess interesting physicochemical and anti-cancer characteristics, such as ROS generation, high retention, enhanced permeability etc., making them attractive candidates for the treatment and diagnosis of cancer. Zinc oxide nanoparticles showed anti-cancer property via excessive reactive oxygen species (ROS) production, and by the destruction of mitochondrial membrane. Here, we have synthesized organic/inorganic hybrid nanosystem composed of chymotrypsin protein (Chymo) with AzureC (AzC) conjugated with Zinc oxide nanoparticles (ZnONPs). The conjugation of AzureC with ZnONPs was confirmed by transmission electron microscopy (TEM), zeta potential, and dynamic light scattering (DLS) experiment. The interaction of Chymo with AzC alone and AzC-ZnONPs was investigated, and it was observed that the interaction was enhanced in the presence of ZnONPs, which was concluded by the results obtained from different spectroscopic techniques such as UV-Visible spectroscopy, fluorescence spectroscopy and circular dichroism in combination with molecular docking. UV-Visible spectroscopic studies and the corresponding binding parameters showed that the binding of AzC-ZnONPs complex with Chymo is much higher than that of AzC alone. Moreover, the fluorescence measurement showed enhancement in static quenching during titration of Chymo with AzC-ZnONPs as compared to dye alone. In addition to this, circular dichroism results show that the dye and dye-NPs conjugate do not cause much structural change in α-Chymo. The molecular docking and thermodynamic studies showed the predominance of hydrogen bonding, Van der Waal force, and hydrophobic forces during the interactions. After correlation of all the data, interaction of Chymo with AzC-ZnONPs complex showed strong interaction as compared to dye alone. The moderate binding with chymo without any alteration in the structure makes it desirable for the distribution and pharmacokinetics. In addition, the in vitro cytotoxicity of the AzC-ZnONPs was demonstrated on A-549 adenocarcinoma cell line. Our findings from physiochemical investigations suggested that the chymotrypsin coated AzC conjugated ZnONPs could be used as the novel nanoconjugates for various cancer phototherapies.

Effects of Origanum vulgare essential oil and its two main components, carvacrol and thymol, on the plant pathogen Botrytis cinerea.

BackgroundBotrytis cinerea causes serious gray mold disease in many plants. This pathogen has developed resistance to many fungicides. Thus, it has become necessary to look for new safe yet effective compounds against B. cinerea.MethodsEssential oils (EOs) from 17 plant species were assayed against B. cinerea, of which Origanum vulgare essential oil (OVEO) showed strong antifungal activity, and accordingly its main components were detected by GC/MS. Further study was conducted on the effects of OVEO, carvacrol and thymol in vitro on mycelium growth and spore germination, mycelium morphology, leakages of cytoplasmic contents, mitochondrial injury and accumulation of reactive oxygen species (ROS) of B. cinerea. The control efficacies of OVEO, carvacrol and thymol on tomato gray mold were evaluated in vivo.ResultsOf all the 17 plant EOs tested, Cinnamomum cassia, Litsea cubeba var. formosana and O. vulgare EOs had the best inhibitory effect on B. cinerea, with 0.5 mg/mL completely inhibiting the mycelium growth of B. cinerea. Twenty-one different compounds of OVEO were identified by gas chromatography–mass spectrometry, and the main chemical components were carvacrol (89.98%), β-caryophyllene (3.34%), thymol (2.39%), α-humulene (1.38%) and 1-methyl-2-propan-2-ylbenzene isopropyl benzene (1.36%). In vitro experiment showed EC50 values of OVEO, carvacrol and thymol were 140.04, 9.09 and 21.32 μg/mL, respectively. Carvacrol and thymol completely inhibited the spore germination of B. cinerea at the concentration of 300 μg/mL while the inhibition rate of OVEO was 80.03%. EC50 of carvacrol and thymol have significantly (P < 0.05) reduced the fresh and dry weight of mycelia. The collapse and damage on B. cinerea mycelia treated with 40 μg/mL of carvacrol and thymol was examined by scanning electron microscope (SEM). Through extracellular conductivity test and fluorescence microscope observation, it was found that carvacrol and thymol led to increase the permeability of target cells, the destruction of mitochondrial membrane and ROS accumulation. In vivo conditions, 1000 μg/mL carvacrol had the best protective and therapeutic effects on tomato gray mold (77.98% and 28.04%, respectively), and the protective effect was significantly higher than that of 400 μg/mL pyrimethanil (43.15%). While the therapeutic and protective effects of 1,000 μg/mL OVEO and thymol were comparable to chemical control.ConclusionsOVEO showed moderate antifungal activity, whereas its main components carvacrol and thymol have great application potential as natural fungicides or lead compounds for commercial fungicides in preventing and controlling plant diseases caused by B. cinerea.

Mitochondria as a Target of Intermittent Hypoxia

The review is focused upon summarizing the current knowledge of the mechanisms of interval hypoxic training (IHT) impact on the mitochondria (Mt) structure and functions in comparison with the effects of acute hypoxia (AH). It has been revealed that AH causes mitochondrial swelling, vacuolization of organelles, disorganization and destruction of mitochondrial membranes. When exposed to IHT, the increase in the total number of mitochondria, the reduction of the number of structurally modified organelles, the appearance of energetically active Mt with vesicular cristae, and the micromitochondria (microMt) formation are observed. One of the key mechanisms of cell damage during hypoxia and reoxygenation is excessive production of reactive oxygen species (ROS) in the mitochondria which oxidize proteins, lipids and DNA. On the other hand, low level of ROS production is protective and serves as a trigger for adaptive responses. IHT leads to reprogramming of the mitochondria metabolism, ensuring adequate production of ATP. The activation of potassium transport in the mitochondrial matrix under IHT is a protective mechanism against Ca2+ overload caused by acute hypoxia. The intensity of neuronal mitochondrial energy production in the brain stem is directly related to the regulation of neurotransmitter metabolism, including glutamate and GABA, which are involved in the mechanisms of respiratory rhythmogenesis formation. All adaptive reactions to hypoxia are regulated by HIF-factors (HIF-1, HIF-2 and HIF-3). Each of HIF-subunits plays a certain role depending on the mode of hypoxia-induced stress. These peculiarities can be important when choosing a mode of IHT to prevent and treat various diseases. New data on the organ specificity of HIF operation provide potential pharmacological regulation of HIFs as a new therapeutic approach for treatment of diseases.

The effect of 2,4-D and ABA on respiration of isolated mitochondria from maize coleoptiles

The susceptibility of isolated maize mitochondria to the growth regulators: 2,4-dichlorophenoxyacetic acid (2,4-D) and abscisic acid (ABA) was studied. It was found that 2,4-D (a herbicide) inhibits respiration in mitochondria, as do other herbicides or phenoxy-acids. In the entire range of concentrations used (10&lt;sup&gt;-3&lt;/sup&gt;-10&lt;sup&gt;-9&lt;/sup&gt; M), 2,4-D introduced into the medium before the respiration reaction was begun, or during it, limited the intensity of succinate oxidation. It did not, however, markedly change phosphorylation properties. Uncoupling of oxidative phosphorylation took place only after preincubation of mitochondria with 2,4-D and was the result of the destruction of mitochondrial membranes. ABA (a growth inhibitor of plants) caused a similar response in maize mitochondria. Preincubation of mitochondria with ABA lead to the uncoupling of oxidative phosphorylation. Whereas ABA introduced during respiration (state 4 respiration) or before its onset, lowered the oxidative potential of mitochondria, it also changed the pattern of state 4-3-4 transition after addition of ADP (it was especially visible at high concentrations), which indicates that the coupling of oxidative phosphorylation with the respiratory chain has faltered. It seems that this negative effect of 2,4-D and ABA on respiration of isolated maize mitochondria is connected with the inhibitory effect of these growth regulators on the growth of maize coleoptiles. Interference in the organization mitochondrial membranes results in a lowered supply of ATP - a source of energy needed in elongation processes.

Physiological role of nitrate under anaerobic stress in Saccharum officinarum callus cells tolerant and sensitive to anoxia

The physiological role of nitrate as a protective factor against anaerobic stress was studied in experiments with tolerant to anoxia sugarcane (Saccharum officibarum L.) callus lines obtained by in vitro selection in the absence of exogenous carbohydrates. Original cell lines, which were not subjected to selection and therefore more sensitive to oxygen shortage, served as a control. In these lines, anaerobic stress was created in the presence or absence of nitrate in nutrient medium. The presence of nitrate in nutrient medium increased markedly tolerance to anaerobic stress of both lines differing in their sensitivity to anaerobiosis. However, the degree of tolerance differed substantially in compared lines. In the presence of exogenous nitrate, in tolerant cells there were no signs of mitochondrial membrane destruction or degradation even after 72 h of anoxia, whereas in control cells 48-h anaerobic incubation led to the complete degradation of mitochondrial membranes and membranes of other organelles. It is concluded that significant increase in the tolerance of S. officinarum cells in the process of in vitro selection most likely occurred due to induction and stimulation of not only the processes of glycolysis and fermentation, but also nitrate and maybe nitrite utilization.

The histone deacetylase inhibitor, Trichostatin A, induces G2/M phase arrest and apoptosis in YD-10B oral squamous carcinoma cells

Histone acetylation is one of the key chromatin modifications that control gene transcription during development and tumorigenesis. Recently, it was reported that the histone deacetylase inhibitor, Trichostatin A (TSA), induces growth arrest and apoptosis in tumors. However, the molecular mechanisms responsible for its antitumor effects are not clear. The purpose of this study was to investigate the effect of TSA on human oral squamous carcinoma cells and to determine the mechanisms underlying the antitumor activity of TSA. MTT assays showed that TSA inhibited cell proliferation in YD-10B cells. TSA also effectively arrested cell cycle progression at the G2/M phase through the up-regulation of p21waf expression, down-regulation of CyclinB1 and reduction of the inhibitory phophorylation of Cdc2. In addition, mitochondrial membrane destruction was induced by a 48 h TSA treatment. TSA also induced cytochrome c release and proteolytic activation of caspase3 and caspase7 in YD-10B cells. Taken together, these observations in YD-10B oral cancer cells reveal the potential value of TSA in inhibiting oral tumor growth.

Protective effect of exogenous nitrate on the mitochondrial ultrastructure ofOryza sativa coleoptiles under strict anoxia

The effect of exogenous KNO3, the terminal acceptor of electrons in oxygen-free medium, on mitochondrial ultrastructure and on the growth rate of 4-day-old rice coleoptiles under strictly anoxic conditions was studied. Exogenous nitrate (10 mM) did not exert any significant effect on the growth rate of coleoptiles of intact seedlings compared to their growth in KNO3-free medium. Anaerobic incubation of detached coleoptiles in KNO3-free medium for 48 h resulted in the complete destruction of mitochondrial and other cell membranes. In the presence of KNO3, no mitochondrial-membrane destruction was observed even after 48 h anoxia although the mitochondrial ultrastructure was modifed. Cristae were arranged in parallel rows and elongated dumbbell-shaped mitochondria appeared in some cells. The data obtained indicate a protective role of exogenous nitrate as electron acceptors in oxygen-free medium. The results of the present investigation are discussed and compared with reports of either markedly damaging or favorable effects of exogenous nitrate on the growth, metabolism, and energetics of rice and other plants under hypoxic and anoxic conditions.

A quantitative evaluation of the extent of inner mitochondrial membrane destruction after freezing-thawing based on functional studies

An assay based on comparative investigation of ATPase and ATP synthetase changes in the activity in rat liver mitochondria after low temperature and uncoupler 2,4-dinitrophenol treatment is considered. By varying the activity of the respiratory chain, three extents of membrane cryoinjury could be distinguished by monitoring the changes in ATPase activity under different types of cryoinfluence. The first extent corresponds to a minimum membrane destruction, where the action of the respiratory chain compensates the changes in proton permeability and the cryotreatment does not change the ATPase activity. The second extent corresponds to changes in ion permeability which is partially compensated by the respiratory chain action. The third extent corresponds to a maximum membrane destruction and, therefore, maximum increase in permeability which is related to the irreversible stimulation of the ATPase activity and complete inhibition of the phosphorylation. In this study the extent of cryoinjury in mitochondrial preparations frozen and thawed at different rates was evaluated using this method.

Mitochondrial Ultrastructure of Three Hygrophyte Species at Anoxia and in Anoxic Glucose-Supplemented Medium

Vartapetian, B. B. and Andreeva, I. N. 1986. Mitochondrial ultrastructure of three hygrophyte species at anoxia and in anoxic glucose-supplemented medium.—J. exp. Bot. 37: 685-692. Mitochondrial ultrastructure of excised roots of Alisma plantago-aquatica L., Lycopus europaeus L. and Glyceria fluitans L. were electron-microscopically studied at anoxia and in anoxic glucose supplemented medium in order to find out if the roots of the three hygrophytes growing on water-logged anaerobic soils have an increased resistance to anoxia. Irreversible destruction of mitochondrial membranes and other subcellular structures was shown to occur in the above plants' roots after 24 h at anoxia or in anoxic glucose-supplemented medium. Only in roots of Glyceria had exogenous glucose a protective action, yet in this case, too, a 48 h anaerobic exposure resulted in a deep-going degradation of cell ultrastructure. It is concluded that though the plants in question grow on soils devoid of 02 their roots avoid anaerobiosis through translocation of 02 from aerated parts, which appears to explain why these plants have not developed a biochemical mechanism of adaptation to anaerobiosis in the process of evolution.