Plasma growth factors maintain constitutive translation in platelets to regulate reactivity and thrombotic potential

ABSTRACT

Mechanisms of proteostasis in anucleate circulating platelets are unknown and may regulate platelet function. We investigated the hypothesis that plasma-borne growth factors/hormones (GFHs) maintain constitutive translation in circulating platelets to facilitate reactivity. Bio-orthogonal noncanonical amino acid tagging (BONCAT) coupled with liquid chromatography-tandem mass spectrometry analysis revealed constitutive translation of a broad-spectrum translatome in human platelets dependent upon plasma or GFH exposure, and in murine circulation. Freshly isolated platelets from plasma showed homeostatic activation of translation-initiation signaling pathways: phosphorylation of p38/ERK upstream kinases, essential intermediate MNK1/2, and effectors eIF4E/4E-BP1. Plasma starvation led to loss of pathway phosphorylation, but it was fully restored with 5-minute stimulation by plasma or GFHs. Cycloheximide or puromycin infusion suppressed ex vivo platelet GpIIb/IIIa activation and P-selectin exposure with low thrombin concentrations and low-to-saturating concentrations of adenosine 5'-diphosphate (ADP) or thromboxane analog but not convulxin. ADP-induced thromboxane generation was blunted by translation inhibition, and secondary-wave aggregation was inhibited in a thromboxane-dependent manner. Intravenously administered puromycin reduced injury-induced clot size in cremaster muscle arterioles, and delayed primary hemostasis after tail tip amputation but did not delay neither final hemostasis after subsequent rebleeds, nor final hemostasis after jugular vein puncture. In contrast, these mice were protected from injury-induced arterial thrombosis and thrombin-induced pulmonary thromboembolism (PE), and adoptive transfer of translation-inhibited platelets into untreated mice inhibited arterial thrombosis and PE. Thus, constitutive plasma GFH-driven translation regulates platelet G protein-coupled receptor reactivity to balance hemostasis and thrombotic potential.

Proteomics-Based Approach for Detailing the Allergenic Profile of Cannabis Chemotypes

Allergic sensitization to cannabis is an emerging public health concern and is difficult to clinically establish owing to lack of standardized diagnostic approaches. Attempts to develop diagnostic tools were largely hampered by the Schedule I restrictions on cannabis, which limited accessibility for research. Recently, however, hemp was removed from the classified list, and increased accessibility to hemp allows for the evaluation of its practical clinical value for allergy diagnosis. We hypothesized that the proteomic profile is preserved across different cannabis chemotypes and that hemp would be an ideal source of plant material for clinical testing. Using a proteomics-based approach, we examined whether distinct varieties of cannabis plant contain relevant allergens of cannabis. Cannabis extracts were generated from high tetrahydrocannabinol variety (Mx), high cannabidiol variety (V1-19) and mixed profile variety (B5) using a Plant Total Protein Extraction Kit. Hemp extracts were generated using other standardized methods. Protein samples were subjected to nanoscale tandem mass spectrometry. Acquired peptides sequences were examined against the Cannabis sativa database to establish protein identity. Non-specific lipid transfer protein (Can s 3) level was measured using a recently developed ELISA 2.0 assay. Proteomic analysis identified 49 distinct potential allergens in protein extracts from all chemotypes. Most importantly, clinically relevant and validated allergens, such as profilin (Can s 2), Can s 3 and Bet v 1-domain-containing protein 10 (Can s 5), were identified in all chemotypes at label-free quantification (LFP) intensities > 106. However, the oxygen evolving enhancer protein 2 (Can s 4) was not detected in any of the protein samples. Similarly, Can s 2, Can s 3 and Can s 5 peptides were also detected in hemp protein extracts. The validation of these findings using the ELISA 2.0 assay indicated that hemp extract contains 30-37 ng of Can s 3 allergen per µg of total protein. Our proteomic studies indicate that relevant cannabis allergens are consistently expressed across distinct cannabis chemotypes. Further, hemp may serve as an ideal practical substitute for clinical testing, since it expresses most allergens relevant to cannabis sensitization, including the validated major allergen Can s 3.

A comparison of the decontamination efficacy of foam-making blends based on cationic and nonionic tensides against organophosphorus compounds determinedin vitro and in vivo

The ability of foam-making blends to decontaminate the skin exposed to organophosphorus compounds was tested. The appropriate composition and rheological features (stability, grade of foaming) of tested blends were evaluated by in vitro methods and their ability to remove the contaminants from hard surface and to transform the contaminants into nontoxic compounds was evaluated byin vivo methods.

The blends containing cationic and nonionic tensides as well as alkalized hydrogen peroxide seem to be the most efficacious to decontaminate the skin exposed to organophosphorus compounds according to the literature data.

The composition of tested blends was optimized because particular components often have antagonistic effects. Cationic tensides support the reactivity of the blend and control the grade of foaming. Nonionic tensides control the stability of the foams but also react as retardants of the reactivity of the foams. Hydrogen peroxide is a real reacting component when it is transformed into hydrogen peroxide anion. It also acts as buffer if pH is higher than 11.

Our in vivo results confirm that Desam OX (34 and 68%) and the foam-making blend containing benzalkonium chloride / Althosan MB (8%), Slovasol 2510 (2%) and hydrogen peroxide (3%) alkalized at pH 12 seem to be the most efficacious to remove contaminants (soman, VX) from the skin and transform them into nontoxic compounds. Therefore they could be used for primary decontamination of chemical casualties contaminated with nerve agents in the field condition.

[DESIDENT CaviCide a new disinfectant]

The properties of the new disinfection agent DESIDENT CaviCide, such as characteristics, disinfection efficiency, biological degradability and ecotoxicity are described. Also areas and forms of usage this biocidal agent are mentioned.

[Foams as disinfectant carriers]

The article deals with surfactants capable of forming an aerodispersive system, foam, under specific conditions as described below. Characteristics of surfactants usable as foaming agents are specified. Attention is paid to detergency and detergent effects of foams, wetting process, dispersion formation, stabilization of foams and stabilizers. Rheological properties of foams, more precisely volume increase and stability, are described. Methods for disinfection efficacy testing of foaming agents are presented. Advantages and disadvantages of using foams for disinfection are summarized: it is concluded that the use of foams in disinfection is universally advantageous and means a great advance in disinfection technology.

The dialysis of Ochratoxin A (OTA)

Standard dialysis did not result in a decrease of the OTA level in the blood serum of patients regularly treated by dialysis. Therefore, we examined the effect of dialysis on both OTA bound to the blood plasma proteins and free OTA. We carried out an in vivo experiment to determine OTA levels in the serum of patients in the terminal stage of chronic renal insufficiency (CHRI) before and after dialysis and also in the dialysate in which we did not find OTA. OTA bound to blood plasma proteins did not penetrate the dialysis membrane. In contrast, free OTA during an in vitro experiment with the identical dialyzer (as during the in vivo experiment), easily penetrated the same dialysis membrane.

Distribution of nickel in body fluids and organs of rats chronically exposed to nickel sulphate

1. Male and female rats were given 100 mg Ni L-1 (as nickel sulphate) in drinking water for 6 months. 2. The feeding of nickel was associated with an increased concentration of nickel in body fluids and organs. The highest concentrations of nickel were found in the liver of both male and female rats. In male rats nickel levels decreased in the order: liver > kidney = whole blood = serum > testes > urine. In female rats the decreasing order was similar: liver > kidney = whole blood = serum = plasma > urine > ovaries. 3. No significant differences were found between nickel concentrations in organs (except ovaries), blood and urine of rats exposed for 3 months and those exposed for 6 months indicating the reaching of a steady state of nickel in the rat during long-term exposure. 4. The urinary excretion of the orally administered nickel was only 2% of absorbed dose (supposing 1% Ni absorption).