Project description:With the advent of nanotechnology, the prospects for using engineered nanomaterials with diameters of < 100 nm in industrial applications, medical imaging, disease diagnoses, drug delivery, cancer treatment, gene therapy, and other areas have progressed rapidly. The potential for nanoparticles (NPs) in these areas is infinite, with novel new applications constantly being explored. The possible toxic health effects of these NPs associated with human exposure are unknown. Many fine particles generally considered "nuisance dusts" are likely to acquire unique surface properties when engineered to nanosize and may exhibit toxic biological effects. Consequently, the nuisance dust may be transported to distant sites and could induce adverse health effects. In addition the beneficial uses of NPs in drug delivery, cancer treatment, and gene therapy may cause unintentional human exposure. Because of our lack of knowledge about the health effects associated with NP exposure, we have an ethical duty to take precautionary measures regarding their use. In this review we highlight the possible toxic human health effects that can result from exposure to ultrafine particles (UFPs) generated by anthropogenic activities and their cardiopulmonary outcomes. The comparability of engineered NPs to UFPs suggests that the human health effects are likely to be similar. Therefore, it is prudent to elucidate their toxicologic effect to minimize occupational and environmental exposure. Highlighting the human health outcomes caused by UFPs is not intended to give a lesser importance to either the unprecedented technologic and industrial rewards of the nanotechnology or their beneficial human uses.
Project description:Intracellular transport is one of the most confusing issues in the field of cell biology. Many different models and their combinations have been proposed to explain the experimental data on intracellular transport. Here, we analyse the data related to the mechanisms of endoplasmic reticulum-to-Golgi and intra-Golgi transport from the point of view of the main models of intracellular transport; namely: the vesicular model, the diffusion model, the compartment maturation-progression model, and the kiss-and-run model. This review initially describes our current understanding of Golgi function, while highlighting the recent progress that has been made. It then continues to discuss the outstanding questions and potential avenues for future research with regard to the models of these transport steps. To compare the power of these models, we have applied the method proposed by K. Popper; namely, the formulation of prohibitive observations according to, and the consecutive evaluation of, previous data, on the basis on the new models. The levels to which the different models can explain the experimental observations are different, and to date, the most powerful has been the kiss-and-run model, whereas the least powerful has been the diffusion model.
Project description:In acute respiratory distress syndrome (ARDS), increased pulmonary vascular permeability makes the lung vulnerable to edema. The use of conservative as compared to liberal fluid strategies may increase the number of ventilator-free days and survival, as well as reduce organ dysfunction. Monitoring the effects of fluid administration is of the utmost importance; dynamic indexes, such as stroke volume and pulse pressure variations, outperform static ones, such as the central venous pressure. The passive leg raise and end-expiratory occlusion tests are recommended for guiding fluid management decisions. The type of intravenous fluids should also be taken into consideration: crystalloids, colloids, and human albumin have all been used for fluid resuscitation. Recent studies have also shown differences in outcome between balanced and non-balanced intravenous solutions. In preclinical studies, infusion of albumin promotes maintenance of the glycocalyx layer, reduces inflammation, and improves alveolar-capillary membrane permeability. Fluids in ARDS must be administered cautiously, considering hemodynamic and perfusion status, oncotic and hydrostatic pressures, ARDS severity, fluid type, volume and infusion rate, and cardiac and renal function. Of note, no guideline to date has recommended a specific fluid composition for use in ARDS; most physicians currently follow recommendations for sepsis.
Project description:Drug-resistant Mycobacterium tuberculosis (MTB), the causative pathogen of tuberculosis (TB), has become a serious threat to global public health. Yet the development of novel drugs against MTB has been lagging. One potentially powerful approach to drug development is computation-aided repositioning of current drugs. However, the effectiveness of this approach has rarely been examined. Here we select the "TB drugome" approach--a protein structure-based method for drug repositioning for tuberculosis treatment--to (1) experimentally validate the efficacy of the identified drug candidates for inhibiting MTB growth, and (2) computationally examine how consistently drug candidates are prioritized, considering changes in input data. Twenty three drugs in the TB drugome were tested. Of them, only two drugs (tamoxifen and 4-hydroxytamoxifen) effectively suppressed MTB growth at relatively high concentrations. Both drugs significantly enhanced the inhibitory effects of three first-line anti-TB drugs (rifampin, isoniazid, and ethambutol). However, tamoxifen is not a top-listed drug in the TB drugome, and 4-hydroxytamoxifen is not approved for use in humans. Computational re-examination of the TB drugome indicated that the rankings were subject to technical and data-related biases. Thus, although our results support the effectiveness of the TB drugome approach for identifying drugs that can potentially be repositioned for stand-alone applications or for combination treatments for TB, the approach requires further refinements via incorporation of additional biological information. Our findings can also be extended to other structure-based drug repositioning methods.
Project description:Over the past decade, it has been well established that tumorigenesis is affected by chronic inflammation. During this event, proinflammatory cytokines are produced by numerous types of cells, such as fibroblasts, endothelial cells, macrophages, and tumor cells, and are able to promote the initiation, progression, and metastasis of different types of cancer. When persistent inflammation occurs, activation of inflammasome complexes is initiated, leading to its assembly and further activation of caspase, production of proinflammatory cytokines, and pyroptosis induction. The function of this multiprotein complex is not only to reassure inflammation and to promote cell death, through caspase activity, but also has been identified to have significant contributions during tumorigenesis and cancer development. So far, many efforts have been made in order to extend the knowledge of inflammasome implications and how its components could be targeted as therapeutic agents. Additionally, microRNAs (miRNAs), evolutionary conserved noncoding molecules, have emerged as pivotal players during numerous biological events by regulating gene and protein expression. Therefore, dysregulations of miRNA expressions have been correlated with inflammation during tumor development. In this review, we aim to highlight the dual role of inflammasomes and proinflammatory cytokines during carcinogenesis paired with the distinguished effects of miRNAs upon inflammation cascades during tumor growth and progression.
Project description:The introduction of C4d in daily clinical practice in the late nineties aroused an ever-increasing interest in the role of antibody-mediated mechanisms in allograft rejection. As a marker of classical complement activation, C4d made it possible to visualize the direct link between anti-donor antibodies and tissue injury at sites of antibody binding in a graft. With the expanding use of C4d worldwide several limitations of C4d were identified. For instance, in ABO-incompatible transplantations C4d is present in the majority of grafts but this seems to point at 'graft accommodation' rather than antibody-mediated rejection. C4d is now increasingly recognized as a potential biomarker in other fields where antibodies can cause tissue damage, such as systemic autoimmune diseases and pregnancy. In all these fields, C4d holds promise to detect patients at risk for the consequences of antibody-mediated disease. Moreover, the emergence of new therapeutics that block complement activation makes C4d a marker with potential to identify patients who may possibly benefit from these drugs. This review provides an overview of the past, present, and future perspectives of C4d as a biomarker, focusing on its use in solid organ transplantation and discussing its possible new roles in autoimmunity and pregnancy.
Project description:In cystic fibrosis (CF) therapy, the recent approval of CF-transmembrane conductance regulator (CFTR) channel modulators is considered to be the major breakthrough. However, the current first-line approach based mainly on pulmonary function to measure effects of the novel therapy, tested by forced expiratory volumes in one second (FEV1), provides restricted sensitivity to detect early structural damages. Accordingly, there is a need for new sensitive surrogate parameters. Most interestingly, these should quantify inflammation that precedes a decline of pulmonary function. We present a novel method assessing inflammatory markers in the upper airways' epithelial lining fluid (ELF) obtained by nasal lavage (NL). In contrast to broncho-alveolar lavage, ELF sampling by NL is an attractive method due to its limited invasiveness which allows repeated analyses, even performed in a home-based setting. In a longitudinal cohort study (ClinicalTrials.gov, Identifier: NCT02311140), we assessed changes of inflammatory mediators in 259 serially obtained nasal lavages taken up to every second day before and during therapy with ivacaftor from ten CF patients carrying a G551D mutation. Patients were trained to sample NL-fluid at home, to immediately freeze and transfer chilled secretions to centers. Neutrophil Elastase, Interleukins IL-1β, IL-6 and IL-8 in NL were quantified. During 8-12 weeks of ivacaftor-treatment, median values of IL-1β and IL-6 significantly declined 2.29-fold (2.97→1.30 pg/mL), and 1.13-fold (6.48→5.72 pg/mL), respectively. In parallel, sweat tests and pulmonary function improved considerably. This is the first study assessing changes of airway inflammation on a day-to-day basis in CF patients receiving a newly administered CFTR-modulator therapy. It proves a decline of airway inflammation during ivacaftor-therapy.
Project description:The ubiquitous distribution of lysosomes and their heterogeneous protein composition reflects the versatility of these organelles in maintaining cell homeostasis and their importance in tissue differentiation and remodeling. In lysosomes, the degradation of complex, macromolecular substrates requires the synergistic action of multiple hydrolases that usually work in a stepwise fashion. This catalytic machinery explains the existence of lysosomal enzyme complexes that can be dynamically assembled and disassembled to efficiently and quickly adapt to the pool of substrates to be processed or degraded, adding extra tiers to the regulation of the individual protein components. An example of such a complex is the one composed of three hydrolases that are ubiquitously but differentially expressed: the serine carboxypeptidase, protective protein/cathepsin A (PPCA), the sialidase, neuraminidase-1 (NEU1), and the glycosidase β-galactosidase (β-GAL). Next to this 'core' complex, the existence of sub-complexes, which may contain additional components, and function at the cell surface or extracellularly, suggests as yet unexplored functions of these enzymes. Here we review how studies of basic biological processes in the mouse models of three lysosomal storage disorders, galactosialidosis, sialidosis, and GM1-gangliosidosis, revealed new and unexpected roles for the three respective affected enzymes, Ppca, Neu1, and β-Gal, that go beyond their canonical degradative activities. These findings have broadened our perspective on their functions and may pave the way for the development of new therapies for these lysosomal storage disorders.
Project description:In therapeutic antitumor vaccination, dendritic cells play the leading role since they decide if, how, when, and where a potent antitumor immune response will take place. Since the disentanglement of the complexity and merit of different antigen-presenting cell subtypes, antitumor immunotherapeutic research started to investigate the potential benefit of targeting these subtypes in situ. This review will discuss which antigen-presenting cell subtypes are at play and how they have been targeted and finally question the true meaning of targeting antitumor-based vaccines.
Project description:Macroalgae stand out for their high content of dietary fiber (30-75%) that include soluble, sulfated (fucoidan, agaran, carrageenan, and ulvan) and non-sulfated (laminaran and alginate) polysaccharides. Many studies indicate that these compounds exert varied biological activities and health-promoting effects and for this reason, there is a growing interest for using them in food products. The aim of this review was to critically evaluate prebiotic properties of algal polysaccharides, i.e., their ability to exert biological activities by modulating the composition and/or diversity of gut microbiota (GM). Pre-clinical studies show that the non-sulfated alginate and laminaran are well-fermented by GM, promoting the formation of short chain fatty acids (SCFAs) including butyrate, and preventing that of harmful putrefactive compounds (NH3, phenol, p-cresol, indole and H2S). Alginate increases Bacteroides, Bifidobacterium, and Lactobacillus species while laminaran mostly stimulates Bacteroides sp. Results with sulfated polysaccharides are more questionable. Agarans are poorly fermentable but agarose-oligosaccharides exhibit an interesting prebiotic potential, increasing butyrate-producing bacteria and SCFAs. Though carrageenan-oligosaccharides are also fermented, their use is currently limited due to safety concerns. Regarding fucoidan, only one study reports SCFAs production, suggesting that it is poorly fermented. Its effect on GM does not indicate a clear pattern, making difficult to conclude whether it is beneficial or not. Notably, fucoidan impact on H2S production has not been evaluated, though some studies report it increases sulfate-reducing bacteria. Ulvan is badly fermented by GM and some studies show that part of its sulfate is dissimilated to H2S, which could affect colonic mitochondrial function. Accordingly, these results support the use of laminaran, alginate and agaro-oligosaccharides as prebiotics while more studies are necessary regarding that of fucoidan, carrageenan and ulvan. However, the realization of clinical trials is necessary to confirm such prebiotic properties in humans.