Characterizing the NLRP3 Inflammasome in Mood Disorders: Overview,Technical Development,and Measures of Peripheral Activation in Adolescent Patients

The NOD-, LRR-, and pyrin-domain-containing protein 3 (NLRP3) inflammasome is a node of intracellular stress pathways and a druggable target which integrates mitochondrial stress and inflammatory cascades. While a body of evidence suggests the involvement of the NLRP3 inflammasome in numerous diseases, a lack of reliable measurement techniques highlights the need for a robust assay using small quantities of biological samples. We present a literature overview on peripheral activation of the NLRP3 inflammasome in mood disorders, then outline a process to develop and validate a robust assay to measure baseline and activated intracellular levels of “apoptosis-associated speck-like protein containing a CARD” (ASC) as a key component of an inflammatory profile in peripheral blood mononuclear cells (PBMC). A consistent association between high NLRP3 mRNA levels and relevant cytokines was seen in the literature. Using our method to measure ASC, stimulation of PBMC with lipopolysaccharide and nigericin or adenosine triphosphate resulted in microscopic identification of intracellular ASC specks, as well as interleukin 1 (IL-1) beta and caspase-1 p10 in the periphery. This was abolished by dose-dependent pre-treatment with 100 nM MCC950. We also report the use of this technique in a small pilot sample from patients with bipolar disorder and depressive disorders. The results show that levels of intracellular ASC and IL-1 beta are sensitive to change upon activation and maintained over time, which may be used to improve the detection of NLRP3 activation and guide personalized therapeutic strategy in the treatment of patients.     

Impaired Retromer Function in Niemann-Pick Type C Disease Is Dependent on Intracellular Cholesterol Accumulation

Niemann-Pick type C disease (NPC) is a rare inherited neurodegenerative disorder characterized by an accumulation of intracellular cholesterol within late endosomes and lysosomes due to NPC1 or NPC2 dysfunction. In this work, we tested the hypothesis that retromer impairment may be involved in the pathogenesis of NPC and may contribute to increased amyloidogenic processing of APP and enhanced BACE1-mediated proteolysis observed in NPC disease. Using NPC1-null cells, primary mouse NPC1-deficient neurons and NPC1-deficient mice (BALB/cNctr-Npc1m1N), we show that retromer function is impaired in NPC. This is manifested by altered transport of the retromer core components Vps26, Vps35 and/or retromer receptor sorLA and by retromer accumulation in neuronal processes, such as within axonal swellings. Changes in retromer distribution in NPC1 mouse brains were observed already at the presymptomatic stage (at 4-weeks of age), indicating that the retromer defect occurs early in the course of NPC disease and may contribute to downstream pathological processes. Furthermore, we show that cholesterol depletion in NPC1-null cells and in NPC1 mouse brains reverts retromer dysfunction, suggesting that retromer impairment in NPC is mechanistically dependent on cholesterol accumulation. Thus, we characterized retromer dysfunction in NPC and propose that the rescue of retromer impairment may represent a novel therapeutic approach against NPC.     

Effect of Cobalt and Chromium Ions on the Chlorhexidine Digluconate as Seen by Intermolecular Diffusion

Metal ions such as cobalt (II) and chromium (III) might be present in the oral cavity, as a consequence of the corrosion of Co-Cr dental alloys. The diffusion of such metal ions into the organism, carried by saliva, can cause health problems as a consequence of their toxicity, enhanced by a cumulative effect in the body. The effect of the chlorhexidine digluconate, which is commonly used in mouthwash formulations, on the transport of these salts is evaluated in this paper by using the Taylor dispersion technique, which will allow an assessment of how the presence of chlorhexidine digluconate (either in aqueous solution or in a commercial formulation) may affect the diffusion of metal ions. The ternary mutual diffusion coefficients of metal ions (Co and Cr) in the presence of chlorhexidine digluconate, in an artificial saliva media, were measured. Significant coupled diffusion of CoCl₂ (and CrCl₃) and chlorhexidine digluconate is observed by analysis of the non-zero values of the cross-diffusion coefficients, D₁₂ and D₂₁. The observed interactions between metal ions and chlorhexidine digluconate suggest that the latter might be considered as an advantageous therapeutic agent, once they contribute to the reduction of the concentration of those ions inside the mouth.     

Changes in chemical composition and nutritional quality of fried sardine (Clupea pilchardus) produced by frozen storage and microwave reheating

Modifications in proximate composition, fatty acids, amino acids and –SH groups content, as well as changes in solubility and nutritional quality of protein, were studied in fillets of sardine (Clupea pilchardus) that had been successively pan-fried, frozen stored and reheated by two different means, namely conventional oven and microwave oven. Upon pan-frying in olive oil the sardine absorbed C18: 1(n-9) and C18: 2(n-6) and lost saturated (SFA) and polyunsaturated fatty acids (PUFA); this loss continued upon reheating, and as a consequence the percentage of MUFA increased compared to the just-fried sardine. A loss of water was observed during all processes. Upon frying there was a decrease of cyst(e)ine. Upon reheating by both microwave and conventional oven, methionine decreased; however, cyst(e)ine only decreased with the use of a conventional oven. A loss of –SH groups was recorded during frying and this phenomenon continued upon reheating. Biological value (BV) together with net protein utilisation (NPU) decreased upon both frying and reheating. © 1997 SCI.     

Unraveling Protein Interactions between the Temperate Virus Bam35 and Its Bacillus Host Using an Integrative Yeast Two Hybrid–High Throughput Sequencing Approach

Bacillus virus Bam35 is the model Betatectivirus and member of the family Tectiviridae, which is composed of tailless, icosahedral, and membrane-containing bacteriophages. Interest in these viruses has greatly increased in recent years as they are thought to be an evolutionary link between diverse groups of prokaryotic and eukaryotic viruses. Additionally, betatectiviruses infect bacteria of the Bacillus cereus group, which are known for their applications in industry and notorious since it contains many pathogens. Here, we present the first protein–protein interactions (PPIs) network for a tectivirus–host system by studying the Bam35–Bacillus thuringiensis model using a novel approach that integrates the traditional yeast two-hybrid system and high-throughput sequencing (Y2H-HTS). We generated and thoroughly analyzed a genomic library of Bam35′s host B. thuringiensis HER1410 and screened interactions with all the viral proteins using different combinations of bait–prey couples. Initial analysis of the raw data enabled the identification of over 4000 candidate interactions, which were sequentially filtered to produce 182 high-confidence interactions that were defined as part of the core virus–host interactome. Overall, host metabolism proteins and peptidases were particularly enriched within the detected interactions, distinguishing this host–phage system from the other reported host–phage PPIs. Our approach also suggested biological roles for several Bam35 proteins of unknown function, including the membrane structural protein P25, which may be a viral hub with a role in host membrane modification during viral particle morphogenesis. This work resulted in a better understanding of the Bam35–B. thuringiensis interaction at the molecular level and holds great potential for the generalization of the Y2H-HTS approach for other virus–host models.     

Engineered Metal-Loaded Biohybrids to Promote the Attachment and Electron-Shuttling between Enzymes and Carbon Electrodes

The inorganic content and the catalytic performance pose metal-loaded enzyme nanoflowers as promising candidates for developing bioelectrodes capable of functioning without the external addition of a redox mediator. However, these protein-inorganic hybrids have yet to be successfully applied in combination with electrode materials. Herein, the synthesis procedure of these bionanomaterials is reproposed to precisely control the morphology, composition, and performance of this particular protein-mineral hybrid, formed by glucose oxidase and cobalt phosphate. This approach aims to enhance the adherence and electron mobility between the enzyme and a carbon electrode. The strategy relies on dressing the protein in a tailored thin nanogel with multivalent chemical motifs. The functional groups of the polymer facilitate the fast protein sequence-independent biomineralization. Furthermore, the engineered enzymes enable the fabrication of robust cobalt-loaded enzyme inorganic hybrids with exceptional protein loads, exceeding 90% immobilization yields. Notably, these engineered biohybrids can be readily deposited onto flat electrode surfaces without requiring chemical pre-treatment. The resulting bioelectrodes are robust and exhibit electrochemical responses even without the addition of a redox mediator, suggesting that cobalt complexes promote electron wiring between the active site of the enzyme and the electrode.     

Stability and stabilisation of penicillin acylase

The stability of an oligomeric enzyme, penicillin acylase, was studied in aqueous media. The enzyme was produced by mutant cells of Escherichia coli ATCC 9637, extracted from the periplasmic space by osmotic shock and further purified using a pseudo‐affinity adsorption process. Enzyme stabilisation attempts were performed with salts, alcohols and sugars. The highest levels of retained activity were obtained in the presence of 15% (w/v) ammonium or sodium sulfate. A kinetic model was proposed to describe the inactivation of penicillin acylase, taking into account results obtained in stability assays performed at different temperatures and with different enzyme concentrations. According to this model, the inactivation of penicillin acylase involves an intermediary active precursor of the enzyme, formed prior to dissociation into sub‐units. © 1999 Society of Chemical Industry     

Solvent extraction of gold by LIX 79: experimental equilibrium study

The extraction of gold(I) from aurocyanide aqueous solutions using LIX 79 has been studied. Different variables that could affect the extraction system were evaluated: equilibration time, aqueous pH, metal and extractant concentrations, organic phase diluent and aqueous ionic strength. The extraction of the aurocyanide complex with respect to other metal‐cyano complexes has also been studied on both synthetic and real leach solutions. Gold experimental data have been analysed numerically to determine the stoichiometry of extracted species and its equilibrium constant. It was found that gold(I) was extracted into the organic phase by the formation of the species RHAu(CN)₂ (LIX 79=R). Stripping of gold from loaded organic phases was carried out using NaOH or NaCN solutions. © 1999 Society of Chemical Industry     

The Secretome of Human Neonatal Mesenchymal Stem Cells Modulates Doxorubicin-Induced Cytotoxicity: Impact in Non-Tumor Cells

Doxorubicin (Dox) is one of the most widely used treatments for breast cancer, although limited by the well-documented cardiotoxicity and other off-target effects. Mesenchymal stem cell (MSC) secretome has shown immunomodulatory and regenerative properties, further potentiated under 3D conditions. This work aimed to uncover the effect of the MSC-derived secretome from 3D (CM3D) or 2D (CM2D) cultures, in human malignant breast cells (MDA-MB-231), non-tumor breast epithelial cells (MCF10A) and differentiated AC16 cardiomyocytes, co-treated with Dox. A comprehensive proteomic analysis of CM3D/CM2D was also performed to unravel the underlying mechanism. CM3D/CM2D co-incubation with Dox revealed no significant differences in MDA-MB-231 viability when compared to Dox alone, whereas MCF10A and AC16 viability was consistently improved in Dox+CM3D-treated cells. Moreover, neither CM2D nor CM3D affected Dox anti-migratory and anti-invasive effects in MDA-MB-231. Notably, Ge-LC-MS/MS proteomic analysis revealed that CM3D displayed protective features that might be linked to the regulation of cell proliferation (CAPN1, CST1, LAMC2, RANBP3), migration (CCN3, MMP8, PDCD5), invasion (TIMP1/2), oxidative stress (COX6B1, AIFM1, CD9, GSR) and inflammation (CCN3, ANXA5, CDH13, GDF15). Overall, CM3D decreased Dox-induced cytotoxicity in non-tumor cells, without compromising Dox chemotherapeutic profile in malignant cells, suggesting its potential use as a chemotherapy adjuvant to reduce off-target side effects.