The African swine fever virus dynein-binding protein p54 induces infected cell apoptosis

A specific interaction of ASFV p54 protein with 8 kDa light chain cytoplasmic dynein (DLC8) has been previously characterized and this interaction is critical during virus internalization and transport to factory sites. During early phases of infection, the virus induces the initiation of apoptosis triggering activation of caspase-9 and -3. To analyze the role of the structural protein p54 in apoptosis, transient expression experiments of p54 in Vero cells were carried out which resulted in effector caspase-3 activation and apoptosis. Interestingly, p54 mutants, lacking the 13 aa dynein-binding motif lose caspase activation ability and pro-death function of p54. This is the first reported ASFV protein which induces apoptosis.     

Synthesis and cardiovascular activity of metoprolol analogues

The synthesis of four novel analogues of metoprolol, a well-known beta1-blocker used to reduce arterial blood pressure, is described. The preparation of (2S,2'S)-7, (2R,2'S)-7, (2R,2'R)-8, and (2S,2'R)-8 was based on the reaction of racemic 2-[4-(2'-methoxyethyl)-phenoxymethyl]-oxirane (4) with (R)- or (S)-2-amino-1-butanol. Salient characteristics of analogues 7 and 8 relative to metoprolol are the incorporation of an additional stereogenic center, as well as a methyl group and a hydroxyl function on the nitrogen-containing chain. These novel derivatives present significant hypotensive and bradycardiac activity, although no blocking action toward beta1 and beta2 adrenergic receptor.     

Conformational Changes in Inositol 1,3,4,5,6-Pentakisphosphate 2-Kinase upon Substrate Binding: ROLE OF N-TERMINAL LOBE AND ENANTIOMERIC SUBSTRATE PREFERENCE

Inositol 1,3,4,5,6-pentakisphosphate 2-kinase (IP(5) 2-K) catalyzes the synthesis of inositol 1,2,3,4,5,6-hexakisphosphate from ATP and IP(5). Inositol 1,2,3,4,5,6-hexakisphosphate is implicated in crucial processes such as mRNA export, DNA editing, and phosphorus storage in plants. We previously solved the first structure of an IP(5) 2-K, which shed light on aspects of substrate recognition. However, failure of IP(5) 2-K to crystallize in the absence of inositide prompted us to study putative conformational changes upon substrate binding. We have made mutations to residues on a region of the protein that produces a clasp over the active site. A W129A mutant allowed us to capture IP(5) 2-K in its different conformations by crystallography. Thus, the IP(5) 2-K apo-form structure displays an open conformation, whereas the nucleotide-bound form shows a half-closed conformation, in contrast to the inositide-bound form obtained previously in a closed conformation. Both nucleotide and inositide binding produce large conformational changes that can be understood as two rigid domain movements, although local changes were also observed. Changes in intrinsic fluorescence upon nucleotide and inositide binding are in agreement with the crystallographic findings. Our work suggests that the clasp might be involved in enzyme kinetics, with the N-terminal lobe being essential for inositide binding and subsequent conformational changes. We also show how IP(5) 2-K discriminates between inositol 1,3,4,5-tetrakisphosphate and 3,4,5,6-tetrakisphosphate enantiomers and that substrate preference can be manipulated by Arg(130) mutation. Altogether, these results provide a framework for rational design of specific inhibitors with potential applications as biological tools for in vivo studies, which could assist in the identification of novel roles for IP(5) 2-K in mammals.     

Life cycle contributions of copper from vessel painting and maintenance activities

Copper-based epoxy and ablative antifouling painted panels were exposed in natural seawater to evaluate environmental loading parameters. In situ loading factors including initial exposure, passive leaching, and surface refreshment were measured utilizing two protocols developed by the US Navy: the dome method and the in-water hull cleaning sampling method. Cleaning techniques investigated included a soft-pile carpet and a medium duty 3M^? pad for fouling removal. Results show that the passive leach rates of copper peaked three days after both initial deployment and cleaning events (CEs), followed by a rapid decrease over about 15 days and a slow approach to asymptotic levels on approximately day 30. Additionally, copper was more bioavailable during a CE in comparison to the passive leaching that immediately followed. A paint life cycle model quantifying annual copper loading estimates for each paint and cleaning method based on a three-year cycle of painting, episodic cleaning, and passive leaching is presented.     

Different mutation profiles associated to P53 accumulation in colorectal cancer

This paper analyzes the DNA code of several species in the perspective of information content. For that purpose several concepts and mathematical tools are selected towards establishing a quantitative method without a priori distorting the alphabet represented by the sequence of DNA bases. The synergies of associating Gray code, histogram characterization and multidimensional scaling visualization lead to a collection of plots with a categorical representation of species and chromosomes.     

Maturation and persistence of the anti-SARS-CoV-2 memory B cell response

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Expression of Caveolin 1 Is Enhanced by DNA Demethylation during Adipocyte Differentiation. Status of Insulin Signaling

Caveolin 1 (Cav-1) is an essential constituent of adipocyte caveolae which binds the beta subunit of the insulin receptor (IR) and is implicated in the regulation of insulin signaling. We have found that, during adipocyte differentiation of 3T3-L1 cells the promoter, exon 1 and first intron of the Cav-1 gene undergo a demethylation process that is accompanied by a strong induction of Cav-1 expression, indicating that epigenetic mechanisms must have a pivotal role in this differentiation process. Furthermore, IR, PKB-Akt and Glut-4 expression are also increased during the differentiation process suggesting a coordinated regulation with Cav-1. Activation of Cav-1 protein by phosphorylation arises during the differentiation process, yet in fully mature adipocytes insulin is no longer able to significantly increase Cav-1 phosphorylation. However, these long-term differentiated cells are still able to respond adequately to insulin, increasing IR and PKB-Akt phosphorylation and glucose uptake. The activation of Cav-1 during the adipocyte differentiation process could facilitate the maintenance of insulin sensitivity by these fully mature adipocytes isolated from additional external stimuli. However, under the influence of physiological conditions associated to obesity, such as chronic inflammation and hypoxia, insulin sensitivity would finally be compromised.     

Proteomic analysis of human osteoarthritic chondrocytes reveals protein changes in stress and glycolysis

Osteoarthritis (OA) is characterized by cartilage degradation. The chondrocyte is the only cell type present in mature cartilage, and it is important in the control of cartilage integrity. The aim of this study was to analyze, by a proteomic approach, the changes that are characteristic of OA chondrocytes, and to identify new OA-related proteins. Chondrocytes were isolated from the cartilage of ten OA patients undergoing joint replacement and ten donors with no history of joint disease. Whole-cell proteins were resolved by 2-DE and stained with SYPRO Ruby. Protein expression patterns of 2-DE gels from OA and normal chondrocyte proteins were analyzed with PDQuest 7.3.1 software. OA-related proteins were identified by MALDI-TOF or MALDI-TOF/TOF MS. The results were validated for ANXA1, GSTO1, GRP78, and HSP90beta in cells by Western blotting and in tissue cartilage by immunohistochemistry. Results showed an average of 700 protein spots that were present in the 2-DE gels. Compared to normal chondrocytes, 19 protein spots were found to be significantly increased in OA cells (ratio OA:N> or =2.0, p<0.05), whereas nine were decreased in OA chondrocytes (ratio OA:N< or =0.5, p<0.05). Three stress response proteins were increased (HSP90beta, GRP78, and GRP94) and three proteins involved in glycolysis were decreased (enolase, glyceraldehyde 3-phosphate dehydrogenase, and fructose biphosphate aldolase). Functionally, almost all proteins could be classified as proteins involved in cellular metabolism (33%), structure (21%), or protein targeting (21%).     

Toxicokinetics of di(2-ethylhexyl) phthalate (DEHP) and its effects on luteal function in sheep

The aim of the present study was to determine the toxicokinetics of short-term exposures to di(2-ethylhexyl) phthalate (DEHP) and its effects on ovarian cyclicity and luteal function using a sheep experimental model. For establishing the model, we examined the clearance of DEHP after intravenous (i.v.) and intramuscular (i.m.) administration of a single dose of 25 mg/kg body weight (b.w.) and after i.m. administration of two different doses (25 and 50 mg/kg b.w.; DEHP25 and DEHP50, respectively) three times a week for two months. Results showed a significant, dose-dependent effect of DEHP administration, when compared to the control group (CTL; untreated ewes; n = 6), on the duration of the ewes’ estrous cycles (17.1 ± 0.5 days, CTL; 15.1 ± 0.9 days, DEHP25; 12.0 ± 0.8 days, DEHP50; p < 0.05); 94.9% of the cycles were of regular duration (15–19 days) in CTL, but only 51.1% and 25.4% in DEHP25 and DEHP50, respectively. Corpora lutea (CL) were smaller in DEHP50 than in DEHP25 (p < 0.05) and were smaller in both groups than in CTL (p < 0.005), but the maximum plasma concentrations of progesterone were greater (p < 0.05) in DEHP25 and DEHP50 than in CTL. In conclusion, the exposure of cycling ewes to DEHP causes shortening of the ovulatory cycles due mainly to a reduction in the size and lifespan of CL. However, the exposure to the phthalate is also associated with an increase in circulating concentrations of progesterone, suggesting the influence of DEHP on steroid metabolism.