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Symptoms of red stripe disease caused by Acidovorax avenae subsp. avenae in Louisiana between 1985 and 2010 were limited to the leaf stripe form, which caused no apparent yield loss. During 2010, the more severe top rot form was observed, and a study was initiated to investigate the distribution of red stripe in the field and determine its effects on cane and sugar yields. Soil properties data, red stripe incidence, and sugarcane yields were all highly variable and were not randomly distributed in the field. Combined harvest data showed a negative correlation between yield components and red stripe incidence, with the strongest relationship between sucrose per metric ton and disease incidence. Red stripe incidence was positively correlated with several soil properties, including phosphorus, potassium, zinc, and calcium. Red stripe incidence also was found to increase with increasing nitrogen rate, with the greatest effects in heavy soils. Results also indicated that using red-stripe-infected cane as a seed source can significantly decrease shoot emergence, stalk population, and subsequent cane and sugar yields. These combined data suggest that red stripe disease can exhibit a highly variable rate of infection in commercial sugarcane fields and may also significantly decrease sugar yields.

Nonalcoholic fatty liver disease (NAFLD) ranges from simple steatosis to steatohepatitis, which may progress to fibrosis, and cirrhosis, leading eventually to hepatocarcinoma development. Recently, cases of hepatocarcinoma have been diagnosed in steatotic patients without nonalcoholic steatohepatitis (NASH) and cirrhosis. The p53 protein, besides its function as tumor suppressor, is emerging as an important regulator of cellular metabolism, but its role in steatosis remains unclear. We induced steatosis in HepG2 (wt-p53) and Huh7.5.1 (Y220C-mutant p53) cells using free fatty acids. We observed a different modulation of p53, different intracellular lipid content, and similar down-regulation of the de novo lipid synthesis genes but opposite modulation of the fatty acid β-oxidation pathway between HepG2 and Huh7.5.1. Accordingly, we found a diverse amount of apoptosis and reactive oxygen species between the two cell lines. Transfection of the wt-p53 in Huh7.5.1 cells reverted the different lipid metabolism behavior observed in these cells. In conclusion, unlike the wt-p53, the Y220C mutant provides a specific protection against steatosis and potentially against its progression. Our findings highlight for the first time an unknown role of a p53 mutant in the setting of steatosis. Being this mutation very frequent in human cancers, this study could be a breakthrough in explaining the occurrence of hepatocarcinoma in steatotic patients without NASH and cirrhosis.

The use of the products derived from the olive tree on human health dates back centuries. In several civilizations, the olive tree had and still has a very strong cultural and religious symbolism. Notably, the official seal and emblem of the World Health Organization features the rod of Asclepius over a world map surrounded by olive tree branches, chosen as a symbol of peace and health. Recently, accumulating experimental, clinical and epidemiological data have provided support to the traditional beliefs of the beneficial effect provided by olive derivates. In particular, the polyphenols present in olive leaves, olives, virgin (unrefined) olive oil and olive mill waste are potent antioxidant and radical scavengers with anti-tumor and anti-inflammatory properties. Here, we review the positive impact on human health of oleuropein, the most prevalent polyphenol present in olives. In addition, we provide data collected in our laboratory on the role of oleuropein in counteracting lipid accumulation in a mouse model of non-alcoholic fatty liver disease.

Background and Aim: Evidence from clinical and laboratory studies have accumulated indicating that the activation of the cannabinoid system is crucial for non-alcoholic fatty liver disease. However, the association between hepatic cannabinoid receptor with mitochondria function has not been well investigated in obesity-induced fatty liver. In this study, we examined the role of a cannabinoid receptor (CBR) and the lipid accumulation in primary hepatocytes and for it’s ability to modulate pathways implicated in obese mice that develop hyperglycemia and fatty livers. Methods and Results: We challenged hepatocytes with high concentrations of a mixture of oleate and palmitate (HFFA) as a model of hepatic lipogenesis and impairment of mitochondria function. Both cannabinoid receptor-1 antagonist AM251 and silencing of the CB1R gene prevented HFFA-stimulated change in intracellular triglyceride levels, the generation of ROS, and mitochondria membrane potential (MMP). On the other hand, AM251 suppression of steatosis was reflected by a lowering in liver triglyceride contents as compared with obese (ob/ob) controls. In addition, AM251 simultaneously decreased hepatic fatty acid synthesis (SREBP-1c, FAS) and increased b-oxidation (CPT-1, CPT-2) genes expression of ob/ob mice. Reduction of SREBP-1 protein level in livers of ob/ob mice by AM251 treatment modestly improves fat drop deposition. This was accompanied by a marked reversal in the expression of mitochondria biogenesis-related factors (PGC1a and NRF1 and 2) as reflected by the elevated expression of mitochondrial complex I and ATP levels. Conclusions: These data suggest that up-regulated CB1-mediated signaling by increasing SREBP-1 proteins, leading to up-regulation of fatty acid synthesis expression and increased oxidative stress in liver. Thus, AM251 may play a modulate role in pathogenesis of the hepatic steatosis and suggest that CB1R antagonist has potential clinical applications in obesity-induced hepatic lipogenesis and that should be explored.

We have tested the hypothesis that guanine-nucleotide-binding-protein-coupled receptors may be able to interact with each other at a molecular level. To address this question, we have initially created two chimeric receptors, alpha 2/m3 and m3/alpha 2, in which the C-terminal receptor portions (containing transmembrane domains VI and VII) were exchanged between the alpha 2C-adrenergic and the m3 muscarinic receptor. Transfection of COS-7 cells with either of the two chimeric constructs alone did not result in any detectable binding activity for the muscarinic ligand N-[3H]methylscopolamine or the adrenergic ligand [3H]rauwolscine. However, cotransfection with alpha 2/m3 and m3/alpha 2 resulted in the appearance of specific binding sites (30-35 fmol/mg of membrane protein) for both radioligands. These sites displayed ligand binding properties similar to those of the two wild-type receptors. Furthermore, COS-7 cells cotransfected with alpha 2/m3 and m3/alpha 2 were able to mediate a pronounced stimulation of phosphatidylinositol hydrolysis upon stimulation with the muscarinic agonist carbachol (Emax approximately 40-50% of wild-type m3). A mutant m3 receptor (containing 16 amino acids of m2 receptor sequence at the N terminus of the third cytoplasmic loop) that was capable of binding muscarinic ligands but was virtually unable to stimulate phosphatidylinositol hydrolysis was also used in various cotransfection experiments. Coexpression of this chimeric receptor with other functionally impaired mutant muscarinic receptors (e.g., with an m3 receptor containing a Pro-->Ala point mutation in transmembrane region VII) resulted in a considerable stimulation of phosphatidylinositol breakdown after carbachol treatment (Emax approximately 40-50% of wild-type m3). Thus, these data suggest that guanine-nucleotide-binding-protein-coupled receptors can interact with each other at a molecular level. One may speculate that the formation of receptor dimers involving the intermolecular exchange of N- and C-terminal receptor domains (containing transmembrane domains I-V and VI and VII, respectively) may underlie this phenomenon.

Because 1-methyl-4-phenyl-2,3-dihydropyridinium ion (MPP+) appears to damage the dopaminergic neuron and cause neuronal death, we characterized [3H]MPP+ binding sites in mouse brain membranes. Among several compounds tested, debrisoquin [3,4-dihydro-2(1H)-isoquinolinecarboxamidine] and some analogues were able to antagonize [3H]MPP+ binding. Debrisoquin is able to block adrenergic transmission and inhibit the activity of monoamine oxidase A (MAO-A). We found a certain correlation between the ability of these agents to displace [3H]MPP+ from its binding sites and their capacity to inhibit MAO-A activity. These data and the finding of a higher number of [3H]MPP+ binding sites in human placenta compared to mouse brain suggest that these sites may correspond to MAO-A enzymes. Recently it has been demonstrated in human brain that neurons in regions rich in catecholamines are positive for MAO-A. Accordingly, we suggest MAO-A as a possible accumulation site of MPP+ within the dopaminergic neuron. We also indicate the chemical structural requirement associated with the best binding of debrisoquin analogues with [3H]MPP+ sites. It would be reasonable to test the effects of debrisoquin-like drugs able to pass the blood-brain barrier on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine toxicity.

The importance of DNA synthesis during the early development of the sea urchin egg is discussed, as compared with the constancy of many other cellular constituents. The amount of enzymes which deaminate dCMP and MedCMP has been determined in different stages of development of the sea urchin embryo. A striking decrease in the two deaminases was observed, see Fig. 6. The following hypotheses have been discussed. (1) A cycle of conversion of the pyrimidine deoxynucleotides may exist in multiplying cells. In this way an appropriate assortment of pyrimidine deoxynucleotides is produced for DNA synthesis. (2) The deamination of dCMP to dUMP may have a pacemaker function for the DNA synthesis.

Unfertilized eggs, and blastula- and gastrula-stage embryos of Sphaerechinus granularis were incubated with [3H]uridine and [3H]cytidine for various lengths of time and their total ribonucleic acid extracted by a dodecyl sulfate-phenol method. Their ribonucleic acid was analyzed by the sucrose density-gradient method. Very little turnover of ribonucleic acid apparently occurs in the unfertilized eggs, but this is probably due to the inability of the precursors to penetrate the eggs. In the embryonic stages, a rapidly labelled ribonucleic acid appears, which is not soluble ribonucleic acid nor ribosomal ribonucleic acid. The nature of this ribonucleic acid, whether it is wholly “messenger” or ribosomal-precursor, or a mixture of both, is not known. Our results suggest that this pulse-labelled ribonucleic acid is of a small pool size, that it turns over rapidly, but it is difficult to demonstrate this experimentally probably because of the small internal precursor pool size and because this pool can be reached only with difficulty by exogenous precursor.

Truncated m2 and m3 muscarinic receptors (referred to as m2- and m3-trunc), containing transmembrane domains I-V and the N-terminal portion of the third cytoplasmic loop, were co-expressed in COS-7 cells with the corresponding C-tenninal receptor fragments (referred to as m2- and m3-tail; containing transmembrane domains VI and VII). Expression of any of these four polypeptides alone did not result in any detectable [3H]N-methylscopolamine ([3H]NMS) binding activity. However, specific [3H]NMS binding sites were observed after co-expression of m2-trunc with m2-tail and m3-trunc with m3-tail. These sites displayed ligand binding properties similar to those of the two wild-type receptors. The ‘reconstituted’ m3-trunc/m3-tail receptor was also able to stimulate agonist-dependent phosphatidyl inositol hydrolysis in a fashion similar to the wild-type m3 receptor, whereas all other polypeptide combinations were inactive. These data suggest that muscarinic receptors are assembled in a fashion analogous to two-subunit receptors.

Our study demonstrates that 3H-1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (3H-MPTP) specifically binds to platelet membrane sites in humans. This specific, high affinity and saturable binding has properties similar to those of 3H-MPTP binding to rat and monkey brain, with a higher affinity. Deprenyl, a specific inhibitor of MAO type B enzyme, was the most potent drug in displacing 3H-MPTP from platelet binding sites. Platelets are considered a good model for central aminergic neurons and are very rich with MAO enzymatic activity, exclusively of type B. Our findings support previous evidence indicating a correspondence between 3H-MPTP binding sites and MAO-B enzyme. Moreover the presence of 3H-MPTP binding sites on human platelets suggests the use of this peripheral tissue as a simple model to study at least partially the mechanisms of neurotoxic action of MPTP.

The low protein synthetic activity of the unfertilized sea urchin egg is attributed to a translational inhibition.1 Most of the attention has focused on the ribosomes, which have proved to be unable to engage in protein synthesis before fertilization.2' 3 The other components for the translation of messenger ribonucleic acid (mRNA) have not been thoroughly studied; in particular, very little is known as to whether or not transfer ribonucleic acids (tRNA) and aminoacyl-sRNA synthetases (EC 6.1.1) play any role in this process. Suggestions to this effect come from the work of Glisin and Glisin4 and Nemer and Bard.5

Previous work from this laboratory has demonstrated that unfertilized sea urchin eggs have very little, if any, ability to incorporate in vivo labelled amino acids into their proteins. Incorporation begins immediately following fertilization but its rate becomes especially high between blastula and midgastrula (1, 10, 12). Experiments carried out in vitro (4, 5) indicate that the ribosomes isolated from unfertilized eggs are unable to incorporate amino acids into proteins but acquire this ability within 30 minutes after fertilization. However, the ribosomes from unfertilized eggs can be induced in vitro to synthesize polyphenylalanine by the addition of synthetic polyuridylic acid (13, 16, 17). These results seem, therefore, to warrant the suggestion that the lack of synthetic ability on the part of the ribosomes of the unfertilized egg may depend on the nonavailability of messenger RNA. That a new synthesis of RNA begins shortly after fertilization is indicated by the recent work of Gross and Cousineau (2). Another important step, and indeed the first one, in the process of protein synthesis to which, in the case of the sea urchin embryo, almost no attention has thus far been paid is the activation of amino acids.

The activity of methionine-activating enzyme has been measured in normal and regenerating rat liver and in hepatoma cells.

The ribosomes of Dictyostelium discoideum and Dictyostelium purpureum have a sedimentation coefficient of about 77 S. Dissociation studies suggest that the ribosomes of the two species might behave differently at various Mg2+ concentrations. The ribosomal RNA is 25 S and 17 S.