Month: January 2019

Beclin1 directly interacts not only with bcl-2 but also with other anti-apoptotic proteins of the bcl-2 family such as bcl-xL. Cardiac bcl-2 overexpression also inhibits autophagy in murine heart cells. This present study focuses on an understanding of the molecular mechanisms underlying DOX-induced cardiac toxicity. It identifies p53 as a candidate in augmenting retrograde signaling leading to cardiac injury by using genetic manipulations, functional tests, ultrastructural analyses, and biochemical assays. One approach to solving this problem is to rely on biochemical assays of oxidatively damaged products. A major problem with these assays, however, is that the oxidatively damaged products are susceptible to further in vitro oxidation, which hinders accurate measurement of levels of oxidatively damaged products in cellular organelles and in specific cell types from complex tissues. To circumvent this problem, the Oberley laboratory and others have developed techniques to localize and quantify oxidatively damaged products using specific antibodies coupled with electron microscopy procedures. Two previous studies have validated the immunomorphologic approaches presented herein by documenting good agreement between biochemical and immunomorphologic analyses in an experimental model of oxidative stress. We have previously shown that DOX causes significant oxidative damage manifested by increased levels of 4HNE adducted protein levels in mitochondria. Recent studies suggest that p53 plays an important role in maintaining Nifedipine mitochondrial function, but it is not known whether the oxidative stress status of the nucleus and mitochondria are differentially affected by p53. JNKs are involved in activation of caspases, but their role is not uncomplicated. JNK activation could be either upstream or downstream of cell death activation, depending on cell type and death-initiating agents. We therefore evaluated whether DOX treatment increases JNK in mitochondria as a result of 4-HNE increase, using a phospho-specific antibody that recognizes dual site phosphorylation of JNK at Thr183 and Tyr185. The best known function of p53 is its action as a transcription factor. p53 can Choline Chloride activate or suppress expression of its target genes in a number of ways. Upon exposure to various forms of stress, such as DNA damage, oncogenic activation, hypoxia, mitotic apparatus dysfunction, telomere erosion, energy stress or oxidative stress, p53 coordinates cellular responses through both transcription-dependent and -independent mechanisms. These responses prevent or repair genomic damage, or eliminate cells when damage is beyond repair. The present study identifies a novel mechanism by which p53 activation selectively enhances DOX-induced oxidative stress in mitochondria, which is manifested by an increase in the level of 4HNE-adducted proteins in the mitochondria.

This activity variation is highly correlated for the two aflatoxins and also for the two furanocoumarins Euphorbia factor L3 angelicin and 8-MOP, but there is very little correlation between activities for the aflatoxin and the two furanocoumarin substrates. The aflatoxins and coumarins in this study may represent only a small proportion of the possible substrates for these enzymes because the a,b-unsaturated lactone moiety that appears to be required for activity occurs in a wide variety of xenobiotics and antibiotics. Such compounds may include UV oxidised polyaromatic hydrocarbons, plant derived lactones such as digitalis and other antibiotics including leptomycin. It remains to be determined as to whether the aflatoxins or coumarins are in fact physiological substrates for any of the enzymes here; some of the host organisms have ecologies which would not likely encompass these specific compounds. Once the coumarins are reduced by the FDR-As they are likely to be further catabolized in the Actinomycetales through the catechol catabolic pathway, providing substrates for the citric acid cycle. In the case of coumarin, dihydrocoumarin resulting from the FDR-catalyzed reduction reaction would be spontaneously hydrolyzed to 3-hydroxyphenyl propionic acid, which could be further hydrolyzed to 2,3-dihydroxyphenyl propionic acid by melilotate hydroxylase, enabling ring meta-cleavage by extradiol dioxygenases. After cleavage, the resulting succinate would enter the citric acid cycle. The other furanocoumarin compounds are Choline Chloride similarly reduced by the FDRs and after further hydrolysis should be ring cleaved by extradiol dioxygenases and lysed to produce succinate, thus also providing a carbon source. Other metabolic fates might also be possible for the possible hydrolyzed intermediates, such as through condensation by 4-coumarate-CoA ligase. Genes encoding FDR-As in Streptomyces species have been found in antibiotic biosynthetic operons, although their exact role in the biosynthesis has not been determined. No operons with at least partially conserved gene complements were found for the genes encoding enzymes in the FDR subclades -A2, -A3 or in the FDR-AA and -B clades. F420 has been shown to be a non-essential cofactor in M. smegmatis but this and other studies have shown that F420 is required for the metabolism of several otherwise recalcitrant molecules. As noted above, the aflatoxins and plant furanocoumarins studied here may only be model substrates for most of the FDR-A enzymes, many of which are in organisms found in environments not likely to encounter such compounds. The FDRAs are a divergent family with few conserved amino acids, thus suggesting the ability to adapt to new substrates and perhaps new cofactors. We have proposed a role of these enzymes in the secondary metabolism of toxic compounds, including antibiotic biosynthesis.

Indeed, mild (S)Ginsenoside-Rh2 mitochondrial uncoupling is a highly effective intervention to prevent the formation of ROS. Interestingly, increased respiratory rates associated with mitochondrial uncoupling are measured in some organisms under caloric restriction, the most widely reproduced approach associated with lifespan extension. CR-induced Calycosin changes in respiratory activity result in lower mitochondrial ROS generation and oxidative damage reinforcing the ����uncoupling to survive���� hypothesis. CR also increases the number of functional respiratory units and promotes changes in mitochondrial dynamics which may affect respiratory rates. Nisoli et al. demonstrated that mitochondrial biogenesis was essential for many beneficial effects of dietary limitation in mice, and that this process was driven by nitric oxide signaling. Biogenesis-promoting NON is synthesized by the endothelial isoform of nitric oxide synthase, an enzyme present in diverse tissues and sensitive to nutritional status which modulates Akt activity and, consequently, eNOS phosphorylation. In addition, long term exposure to elevated ROS levels impairs eNOS activity. As a result, mitochondrial biogenesis is regulated by changes in animal energy metabolism as well as the redox state of the tissue. We recently demonstrated that murine lifespan can be extended by low doses of the mitochondrial uncoupler 2,4-dinitrophenol in a manner accompanied by weight loss, lower serological levels of glucose, insulin and triglycerides as well as a strong decrease in biomarkers of oxidative damage and tissue ROS release. Similar effects have been repeatedly reported using CR diets. Based on the similarities between these two interventions, we hypothesized that DNP treatment could also lead to enhanced mitochondrial biogenesis. In this manuscript, we measured the effects of DNP treatment and CR on mitochondrial biogenesis and associated pathways. We observed that both DNP and CR increase mitochondrial biogenesis as well as basal Akt and eNOS activities, confirming that signaling events in both treatments converge. This is the first experimental evidence that uncoupling in vivo can impact mitochondrial number and function. Most of them are 10�C50 residues in length. They can provide an effective and fast acting defense against harmful microorganisms. There are two major vertebrate antimicrobial peptide families including cathelicidins and defensins. Cathelicidins have been found in many mammalians and birds. Recently, a few cathelicidin antimicrobial peptides were identified from snake venoms. They are the first report of reptile cathelicidins. Acne vulgaris is the most common skin disease. It often occured in areas containing large skin oil glands, such as face, back, and trunk. The pathogenesis of acne is currently attributed to multiple factors such as hormonal factors, hyperkeratinization, resident microbiota, sebum, nutrition, cytokines and toll-like receptors.

Lipase is one of the most utilized classes of biocatalysts. It can be widely used in the enzymatic organic synthesis and clinical analysis. Denaturation of lipase, which destroys its catalytic activity and stability, can be induced by heat or organic solvents. Thus, the lipase-NPG biocomposite was investigated under different experimental conditions. The results showed that the novel biocomposite possessed significantly enhanced reaction durability under various thermal and in organic solvent systems. In addition, a conservative estimation suggested that the lipase-NPG biocomposite could retain its high activity for at least 240 h in transesterification reaction system. These results were markedly better than previous reports where a significant decrease in activity was observed within 10 recycles in biodiesel production using immobilized lipase. The high conversion rate once again confirmed that NPG is an excellent support for enzyme immobilization. The above results clearly suggested that the immobilization using bio-compatible and highly conductive NPG could enhance the stability of enzymes. The excellent catalytic performance and stability of the enzyme-NPG biocomposites might be explained by their physical confinement inside the relatively small pores. Especially, the size match between pore dimension and the molecular diameter of enzymes and the suitability of gold to function as an immobilization medium are of key importance in achieving high enzymatic stability. This involves the adsorption of the enzyme with its active site oriented away from the porous surface with little leaching yet sufficient mobility to retain catalytic activity. Moreover, it is well accepted that the interaction of nanoscale gold with NH2 was as strong as that with the commonly used SH. The lipase from Pseudomonas cepacia has fourteen lysine residues and six cysteine residues. The covalent attachments of enzymes by the amino and mercapto groups onto the surface of NPG could prevent the enzyme leaching, and the curvatures of the porous surfaces could provide an ideal configuration for multipoint covalent attachments to global enzyme molecules, resulting in better operational stability. To prove this, X-ray photoelectron spectroscopy was used to probe the chemical state of the surface for the lipase-NPG biocomposite. In free lipase, there is only a single broad peak at about 163.7 eV for S2p. In contrast, after immobilization on NPG, it splits into two peaks with binding energy in the range from 162.0 to 165.0 eV corresponding to the chemical states of sulfur in Au-S and S-H, respectively. Additionally, the N1s binding energy of nitrogen in protein at 399.6 eV was also observed in the lipase-NPG biocomposite as shown in Figure 7b, while no the signal of N1s was observed on the bare NPG.

The effect of dosage on the transcriptional profiles becomes clearer from the clustering analysis of samples from each pesticide treatment. The gene expression was concentration dependent and showing a distinct chemical-related pattern. In dimethoate exposures, the two lower and two higher concentrations were grouped separately, whereas for atrazine and carbendazim the concentrations that effect on reproduction were more closely related. Expression profiles show distinct patterns for each pesticide, suggesting that responses occur through different molecular pathways. These different responses are depicted by the different directions in which the same genes are 2-Thiouracil affected and by the uniquely affected transcripts in each pesticide exposure. The number of GYKI-52466 common and uniquely affected transcripts is represented in the Venn diagram of Figure 3. The number of overlapping genes, as an indicative of a common response, is higher between carbendazim and dimethoate. Atrazine seems to induce a more similar response to carbendazim than to dimethoate and, in fact, only 38 transcripts were exclusively affected by this herbicide. Overall, 49 transcripts are affected by all compounds which may represent general stress responses to stress. From the 49 genes, 11 have known homologies and code for e.g. heat shock protein 90, lombricine kinase, neutral and basic amino acid transport protein or integrin-linked kinase associated serine threonine phosphatase. The seven different sets of differentially expressed genes, as presented in the Venn diagram, correspond to 3 lists of uniquely affected transcripts by each pesticide and 4 lists of transcripts shared by two or three of these compounds. Those lists were used to perform an improved gene set enrichment analysis of GO terms and evaluate the biological functions significantly affected in each case. All differentially expressed genes, with significant blast homologies, present in each of the seven lists used for this analysis can be found in Table S4. Although several genes, and consequently biological processes, were affected by two or even by the three pesticides tested, some of these transcript expressions were negatively correlated, which can be seen in the heat map with the whole gene expression profiles. From this clustering analysis it is possible to observe that effects of atrazine and carbendazim were more closely related than effects of dimethoate. The behaviour of gene expression change across the range of concentrations of each pesticide is represented in Figure 4 for some of the significant differentially expressed transcripts involved in the biological processes mentioned above. Overall, and considering all the concentrations, the herbicide atrazine was the compound that induced less gene expression changes. This is not particularly surprising given that this is a compound designed to affect mainly plant organisms. Additionally, studies in fish and human cell lines with atrazine did not reveal significant changes in gene expression. In general there was an increase in the number of affected transcripts with increasing concentrations. This tendency was also observed in a study with E. albidus exposed to Cd and Zn. On the contrary, this was not the pattern when Cu was tested in this species or phenanthrene in the collembolan Folsomia candida. Although the same effect concentrations on reproduction were tested for all pesticides, the gene expression correlation between concentrations was different depending on the pesticide. These results indicate different mechanisms underlying reductions on the reproduction rates.