Multilayered Polyelectrolyte Microcapsules: Interaction with the Enzyme Cytochrome C Oxidase

Cell-sized polyelectrolyte capsules functionalized with a redox-driven proton pump protein were assembled for the first time. The interaction of polyelectrolyte microcapsules, fabricated by electrostatic layer-by-layer assembly, with cytochrome c oxidase molecules was investigated. We found that the cytochrome c oxidase retained its functionality, that the functionalized microcapsules interacting with cytochrome c oxidase were permeable and that the permeability characteristics of the microcapsule shell depend on the shell components. This work provides a significant input towards the fabrication of an integrated device made of biological components and based on specific biomolecular functions and properties.     

Dendritic cell recovery post-lymphodepletion: a potential mechanism for anti-cancer adoptive T cell therapy and vaccination

Adoptive transfer of autologous tumor-reactive T cells holds promise as a cancer immunotherapy. In this approach, T cells are harvested from a tumor-bearing host, expanded in vitro and infused back to the same host. Conditioning of the recipient host with a lymphodepletion regimen of chemotherapy or radiotherapy before adoptive T cell transfer has been shown to substantially improve survival and anti-tumor responses of the transferred cells. These effects are further enhanced when the adoptive T cell transfer is followed by vaccination with tumor antigens in combination with a potent immune adjuvant. Although significant progress has been made toward an understanding of the reasons underlying the beneficial effects of lymphodepletion to T cell adoptive therapy, the precise mechanisms remain poorly understood. Recent studies, including ours, would indicate a more central role for antigen presenting cells, in particular dendritic cells. Unraveling the exact role of these important cells in mediation of the beneficial effects of lymphodepletion could provide novel pathways toward the rational design of more effective anti-cancer immunotherapy. This article focuses on how the frequency, phenotype, and functions of dendritic cells are altered during the lymphopenic and recovery phases post-induction of lymphodepletion, and how they affect the anti-tumor responses of adoptively transferred T cells.     

Role of Mechanical Cues in Cell Differentiation and Proliferation: A 3D Numerical Model

Cell differentiation, proliferation and migration are essential processes in tissue regeneration. Experimental evidence confirms that cell differentiation or proliferation can be regulated according to the extracellular matrix stiffness. For instance, mesenchymal stem cells (MSCs) can differentiate to neuroblast, chondrocyte or osteoblast within matrices mimicking the stiffness of their native substrate. However, the precise mechanisms by which the substrate stiffness governs cell differentiation or proliferation are not well known. Therefore, a mechano-sensing computational model is here developed to elucidate how substrate stiffness regulates cell differentiation and/or proliferation during cell migration. In agreement with experimental observations, it is assumed that internal deformation of the cell (a mechanical signal) together with the cell maturation state directly coordinates cell differentiation and/or proliferation. Our findings indicate that MSC differentiation to neurogenic, chondrogenic or osteogenic lineage specifications occurs within soft (0.1-1 kPa), intermediate (20-25 kPa) or hard (30-45 kPa) substrates, respectively. These results are consistent with well-known experimental observations. Remarkably, when a MSC differentiate to a compatible phenotype, the average net traction force depends on the substrate stiffness in such a way that it might increase in intermediate and hard substrates but it would reduce in a soft matrix. However, in all cases the average net traction force considerably increases at the instant of cell proliferation because of cell-cell interaction. Moreover cell differentiation and proliferation accelerate with increasing substrate stiffness due to the decrease in the cell maturation time. Thus, the model provides insights to explain the hypothesis that substrate stiffness plays a key role in regulating cell fate during mechanotaxis.     

Incorporation of negative rules and evolution of a fuzzy controller for yeast fermentation process

The control of bioprocesses can be very challenging due to the fact that these kinds of processes are highly affected by various sources of uncertainty like the intrinsic behavior of the used microorganisms. Due to the reason that these kinds of process uncertainties are not directly measureable in most cases, the overall control is either done manually because of the experience of the operator or intelligent expert systems are applied, e.g., on the basis of fuzzy logic theory. In the latter case, however, the control concept is mainly represented by using merely positive rules, e.g., “If A then do B”. As this is not straightforward with respect to the semantics of the human decision-making process that also includes negative experience in form of constraints or prohibitions, the incorporation of negative rules for process control based on fuzzy logic is emphasized. In this work, an approach of fuzzy logic control of the yeast propagation process based on a combination of positive and negative rules is presented. The process is guided along a reference trajectory for yeast cell concentration by alternating the process temperature. The incorporation of negative rules leads to a much more stable and accurate control of the process as the root mean squared error of reference trajectory and system response could be reduced by an average of 62.8 % compared to the controller using only positive rules.     

α-Synuclein Levels in Blood Plasma from LRRK2 Mutation Carriers

The diagnosis of Parkinson’s disease (PD) remains primarily a clinical issue, based mainly on phenotypic patterns. The identification of biomarkers capable of permitting the preclinical detection of PD is critically needed. α-Synuclein is a key protein in PD, with missense and multiplication mutations in the gene encoding α-synuclein (SNCA) having been reported in familial cases of PD, and accumulation of the protein identified in Lewy bodies (LBs) and Lewy neurites (LNs) in affected brain regions. With the objective of validating the use of α-synuclein as a clinical or progressive biomarker in an accessible tissue, we used an enzyme-linked immunosorbent assay (ELISA) to measure α-synuclein levels in the peripheral blood plasma of idiopathic PD and LRRK2 mutation carrier patients and compared our findings with healthy control subjects. Compared to healthy controls, we found a significant decrease in plasma total α-synuclein levels in idiopathic PD (iPD) patients (n = 134, p = 0.010). However, the reduction was less significant in patients who were LRRK2 mutation carriers (n = 32, p = 0.133). This lack of significance could be due to the small number of individuals employed in this group. No predictive value of total α-synuclein in the diagnosis of PD was found in a receiver operating characteristic (ROC) curve analysis. Although this is a pilot study requiring corroboration on a larger cohort of patients, our results highlight the possible use of plasma α-synuclein as a biomarker for PD.     

Miospore stratigraphy of Lower and early Middle Devonian deposits from Tidikelt, Central Sahara, Algeria

The Tidikelt region forms an outstanding area for subsurface Lower Devonian stratigraphy in the central Algerian Sahara. Sediments from five boreholes have revealed abundant and diverse assemblages of miospores, acritarchs, chitinozoa, scolecodont and microplant remains. The miospores are moderately well preserved. Three new miospore species (Dibolisporites saharansis nov. sp. Hassan Kermandji, Acinosporites conatus nov. sp. Hassan Kermandji and Scylaspora tidikeltense nov. sp. Hassan Kermandji) are described. Miospore assemblages vary through the regressive and transgressive sequences. Seven miospore assemblage biozones, including six new miospore assemblage biozones (Scylaspora tidikeltense-Perotrilites microbaculatus, Dictyotriletes emsiensis-Emphanisporites spinaeformis, Apiculiretusispora arenorugosa-Camptozonotriletes caperatus, Verrucosisporites polygonalis-Dictyotriletes subgranifer, Emphanisporites annulatus-Geminospora svalbardiae, Hystricosporites microancyreus-Grandispora protea, Calyptosporites velatus-Rhabdosporites langii) are proposed for the Lower and early Middle Devonian rocks of Tidikelt Plateau. The combined use of distinctive, wide distribution cosmopolitan and Gondwanan forms as biozonal and species characteristics permits accurate subdivision, dating and correlation of Tidikelt successions with other similar miospore zones of the Lower Devonian of Europe, Canada and other parts of Gondwana plate. The miospore data provide new explanations to stratigraphic relationships of regional rock units, sedimentary cycles and stratigraphic hiatus. The miospore biozones are proposed as a provincial biozonation, which may also be applied to other Palaeozoic rocks of similar miospore content.     

Characterization of an α-haloalkanoic acid–degrading Pseudomonas aeruginosa MX1 isolated from contaminated seawater

Halogenated compounds such as α-halocarboxylix acids (αHAs) are widely liberated into the ecosystem through the prevailing xenobiotic activities that involve the use of herbicides for weed management in the agricultural sector and mass production of various commercial halogenated chemical intermediates. Since such compounds exert stress on the environment owing to their recalcitrance and are not easily degraded, the study aimed to isolate, identify, and characterize dehalogenase-producing bacteria with the purpose of bioremediation. The MX1 bacterium was successfully isolated from seawater samples off the coast of Desaru, Malaysia, using an enrichment technique supplemented with 2,2-dichloropropionic acid (2,2-DCP). Interestingly, the MX1 strain grew best in a 20 mM 2,2-DCP minimal medium as the sole carbon source and illustrated a 44 ± 0.2 h cell-doubling time as well as a 38 μmol Cl^?/ml maximum rate of chloride ion release. However, 2,2-DCP–containing medium with concentrations that exceeded 30 mM inhibited the growth of the MX1, possibly attributable to the increased toxicity of the compound on the bacteria. Biochemical examinations and 16S rDNA sequence analysis revealed that the MX1 strain shares high identity to Pseudomonas aeruginosa, and the gene sequence was deposited into GenBank as Pseudomonas aeruginosa MX1 under accession number KP336490. The presence of the putative dehalogenase gene in the MX1 strain was established by polymerase chain reaction (PCR) analysis, which proved the presence of conserved amino acid residues belonging to the Group I dehalogenase. This is the first report detailing a P. aeruginosa strain capable of degrading the recalcitrant 2,2-DCP and its functional amino acid residues.     

Prostatic Cell-Specific Regulation of the Synthesis of MUC1-Associated Sialyl Lewis a

Sialyl Lewis antigens are selectin ligands involved in leukocyte trafficking and cancer metastasis. Biosynthesis of these selectin ligands occurs by the sequential actions of several glycosyltransferases in the Golgi apparatus following synthesis of the protein backbone in the endoplasmic reticulum. In this study, we examine how the synthesis of sialyl Lewis a (sLe^a) is regulated in prostatic cells and identify a mucin that carries this glycotope. We treat human prostatic cells including one normal and three cancerous cells with histone deacetylase inhibitors, valproic acid, tricostatin A (TSA), and suberoylanilide hydroxamic acid (SAHA), and then monitor the expression of sLe^a. We have found that SAHA enhances the production of sLe^a in normal prostatic RWPE-1 cells but not prostatic cancer cells. Employing siRNA technology and co-immunoprecipitation, we show that the sLe^a is associated with MUC1, which is confirmed by confocal immunofluorescence microscopy and proximity ligation assay. The SAHA-induced production of sLe^a in RWPE-1 cells is resulted from upregulation of B3GALT1 gene via enhancement of acetylated histone-3 and histone-4. Interestingly, PC3 and LNCaP C-81 cells do not produce detectable amounts of sLe^a despite expressing high levels of B3GALT1. However, the MUC1-associated sLe^a is generated in these cells after introduction of MUC1 cDNA. We conclude that the synthesis of sLe^a is controlled by not only peptide backbone of the glycoprotein but also glycoprotein-specific glycosyltransferases involved in the synthesis of sLe^a. Further, the SAHA induction of this selectin ligand in normal prostatic cells may pose a potentially serious side effect of this drug recently approved by the US Food and Drug Administration.