The Immunostimulatory Effect of Biogenic Selenium Nanoparticles on the 4T1 Breast Cancer Model: an In Vivo Study

Selenium salts as well as elemental selenium nanoparticles are attracting the attention of researchers due to their excellent biological properties. The aim of the present work was to study immunomodulation by applying elemental Se NPs to stimulate the immune response of mice bearing 4?T1 breast cancer tumors. Six- to 8-week-old female inbred BALB/c mice were divided into two groups of test and control, each containing 15 mice. Every day, for 2?weeks prior to tumor induction, selenium nanoparticles were orally administered to the mice at a dose of 100?μg/day. Then, 1?×?10(6) cells from a 4?T1 cell line were injected subcutaneously to each mouse. Oral nanoparticle administration was continued daily for 3?weeks after tumor induction. Different immunological parameters were then evaluated including cytokine level, delayed type hypersensitivity (DTH) response as well as tumor growth and the survival rates in all treated or nontreated animals. The production of Th1 cytokines, such as IFN-γ and IL-12, in spleen cell culture was increased in the test mice-administered selenium nanoparticles. The DTH response of test mice also showed a significant increase when compared to the control mice. The survival rate was notably higher for the selenium nanoparticle-treated mice compared to the control mice. Our results suggest that selenium nanoparticle administration can result in considerable induction of the Th1 platform of immune response through the elevation of IFN-γ and IL-12 and may be a cause for better prognosis in mice with tumors.     

Synthesis, antibacterial activity, and quantitative structure-activity relationships of new (Z)-2-(nitroimidazolylmethylene)-3(2H)-benzofuranone derivatives

A new series of (Z)-2-(1-methyl-5-nitroimidazole-2-ylmethylene)-3(2H)-benzofuranones (11a-p) and (Z)-2-(1-methyl-4-nitroimidazole-5-ylmethylene)-3(2H)-benzofuranones (12a-m) were synthesized and assayed for their antibacterial activity against Gram-positive and Gram-negative bacteria. Most of the 5-nitroimidazole analogues (11a-p) showed a remarkable inhibition of a wide spectrum of Gram-positive bacteria (Staphylococcus aureus, Streptococcus epidermidis, MRSA, and Bacillus subtilis) and Gram-negative Klebsiella pneumoniae, whereas 4-nitroimidazole analogues (12a-m) were not effective against selected bacteria. The quantitative structure-activity relationship investigations were applied to find out the correlation between the experimentally evaluated activities with various parameters of the compounds studied. The QSAR models built in this work had reasonable predictive power and could be explained by the observed trends in activities.     

Poly (3-hydroxybutyrate-co-3-hydroxyvalerate) improved osteogenic differentiation of the human induced pluripotent stem cells while considered as an artificial extracellular matrix

Cocell polymers can be the best implants for replacing bone defects in patients. The pluripotent stem cells produced from the patient and the nanofibrous polymeric scaffold that can be completely degraded in the body and its produced monomers could be also usable are the best options for this implant. In this study, electrospun poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) nanofibers were fabricated and characterized and then osteogenic differentiation of the human-induced pluripotent stem cells (iPSCs) was investigated while cultured on PHBV scaffold. MTT results showed that cultured iPSCs on PHBV proliferation were increased compared to those cultured on tissue culture polystyrene (TCPS) as the control. Alkaline phosphatase (ALP) activity and calcium content were also significantly increased in iPSCs cultured on PHBV compared to the cultured on TCPS under osteogenic medium. Gene expression evaluation demonstrated that Runx2, collagen type I, ALP, osteonectin, and osteocalcin were upregulated in iPSCs cultured on PHBV scaffold in comparison with those cultured on TCPS for 2 weeks. Western blot analysis have shown that osteocalcin and osteopontin expression as two major osteogenic markers were increased in iPSCs cultured on PHBV scaffold. According to the results, nanofiber-based PHBV has a promising potential to increase osteogenic differentiation of the stem cells and iPSCs-PHBV as a cell-co-polymer construct demonstrated that has a great efficiency for use as a bone tissue engineered bioimplant.     

Diversity of actin architecture in human osteoclasts: network of curved and branched actin supporting cell shape and intercellular micrometer-level tubes

Osteoclasts are multinucleated bone-resorbing cells with a dynamic actin cytoskeleton. Osteoclasts are derived from circulating mononuclear precursors. Confocal and stimulated emission depletion (STED) super-resolution microscopy was used to investigate peripheral blood-derived human osteoclasts cultured on glass surfaces. STED and confocal microscopy demonstrated that the actin was curved and branched, for instance, in the vicinity of membrane ruffles. The overall architecture of the curved actin network extended from the podosomes to the top of the cell. The other novel finding was that a micrometer-level tube containing actin bridged the osteoclasts well above the level of the culture glass. The actin filaments of the tubes originated from the network of curved actin often surrounding a group of nuclei. Furthermore, nuclei were occasionally located inside the tubes. Our findings demonstrated the accumulation of c-Src, cortactin, cofilin, and actin around nuclei suggesting their role in nuclear processes such as the locomotion of nuclei. ARP2/3 labeling was abundant at the substratum level of osteoclasts and in the branched actin network, where it localized to the branching points. We speculate that the actin-containing tubes of osteoclasts may provide a means of transportation of nuclei, e.g., during the fusion of osteoclasts. These novel findings can pave the way for future studies aiming at the elucidation of the differentiation of multinucleated osteoclasts.     

Delignification and detoxification of peanut shell bio-waste using an extremely halophilic laccase from an Aquisalibacillus elongatus isolate

Extremophiles - Lignocellulose bioconversion is a harsh process requiring the use of surfactants and organic solvents. Consequently, the incorporation of laccases in this bioconversion requires the...     

Production of cholesterol oxidase by a newly isolated Rhodococcus sp.

Fifteen strains of microorganisms with ability to degrade cholesterol were isolated. Among them a Gram-positive, non-motile, non-sporing bacterium with meso-DAP in the cell wall and with a rod-coccus cycle showed the highest ability for cholesterol degradation. It was identified as Rhodococcus sp. strain 2C and was deposited by code 1633 in Persian type culture collection (PTCC). This strain was able to produce high levels of both extracellular and cell-bound cholesterol oxidases in media containing cholesterol as a sole carbon source. The effects of medium composition and physical parameters on cholesterol oxidase production were studied. The optimized medium was found to contain cholesterol 0.15% (w/v), yeast extract 0.3% (w/v), diammonium hydrogen phosphate 0.1% (w/v), Tween 80 (0.05%). The optimum pH and temperature for cholesterol oxidase production in optimized medium were found to be 8–30 °C respectively. Triton X-100 showed the greatest effect in releasing the cell-bound enzyme. The first and most probably the main metabolite of cholesterol degradation was purified and identified as 4-cholestene-3-one.     

Self-organization of domain structures by DNA-loop-extruding enzymes

The long chromosomal DNAs of cells are organized into loop domains much larger in size than individual DNA-binding enzymes, presenting the question of how formation of such structures is controlled. We present a model for generation of defined chromosomal loops, based on molecular machines consisting of two coupled and oppositely directed motile elements which extrude loops from the double helix along which they translocate, while excluding one another sterically. If these machines do not dissociate from DNA (infinite processivity), a disordered, exponential steady-state distribution of small loops is obtained. However, if dissociation and rebinding of the machines occurs at a finite rate (finite processivity), the steady state qualitatively changes to a highly ordered ‘stacked’ configuration with suppressed fluctuations, organizing a single large, stable loop domain anchored by several machines. The size of the resulting domain can be simply regulated by boundary elements, which halt the progress of the extrusion machines. Possible realizations of these types of molecular machines are discussed, with a major focus on structural maintenance of chromosome complexes and also with discussion of type I restriction enzymes. This mechanism could explain the geometrically uniform folding of eukaryote mitotic chromosomes, through extrusion of pre-programmed loops and concomitant chromosome compaction.     

Side-chain cleavage and C-20 ketone reduction of hydrocortisone by a natural isolate ofChroococcus dispersus

A unicellular cyanobacterium,Chroococcus dispersus (Keissl.) Lemmermann, was isolated from paddy-field and tested in biotransformation experiments of hydrocortisone (compound 1). This strain has not been previously examined for steroid substance modification. Fermentation was carried out in BG-11 medium supplemented with 0.05% substrate at 25 °C for seven days incubation. The metabolites were chromatographically purified and characterised using spectroscopic methods. The fermentation yielded 11β,17α,20β,21-tetrahydroxypregn-4-en-3-one (compound 2), 11β,17β-dihydroxyandrost-4-en-3,17-dione (compound 3), and 11β-hydroxyandrost-4-en-3,17-dione (compound 4). Bioreaction characteristics observed were 20-ketone reduction for accumulation of compound 2 and side chain degradation of the substrate to give compounds 3 and 4. Time course study showed the accumulation of the product 2 from the second day of the fermentation and product 3 as well as product 4 from the third day. All the metabolites reached their maximum concentration in seven days. Aeration and continuous light or light duration (16/8 hours light/dark) have no effect on the transformation yield. Optimum concentration of the substrate, which gave maximum bioconversion efficiency, was 0.5 mg ml^?1 in the transformation experiment. Growth was not influenced by the addition of steroid substrate. Biotransformation was completely inhibited when steroid concentration was above 2.0 mg ml^?1.     

Improved angiogenic activity of endothelial progenitor cell in diabetic patients treated with insulin plus metformin

Type 2 diabetes (T2DM) is associated with an increased vascular disease. Moreover, endothelial progenitor cell (EPC) function is impaired in diabetic patients. Decreased EPC number plays a critical role in reduced endothelial repair and development of the vascular disorder. To determine the effect of metformin and insulin plus metformin on functional activity of EPCs, 130 participants were divided into three groups (group 1: healthy control; group 2: metformin; group 3: insulin plus metformin). The concentration of EPCs in the circulation was first quantified. Thereafter, circulating EPCs (cEPCs) were harvested and the biological features of these cells including proliferative, clonogenicity, tubulogenic, and migratory properties were analyzed after expansion. The serum protein levels of some proangiogenic factors were also measured. Our results showed greater numbers of cEPCs in control and in diabetic patients treated with insulin plus metformin than in metformin-treated patients. Insulin plus metformin therapy was associated with augmented proliferative, clonogenicity, migratory, and tubulogenic activity of cEPCs in patients with T2DM. Increased serum concentrations of angiogenic factors were also observed in patients treated with insulin plus metformin. Western blot analysis showed increased protein levels of pTie-2/Tie2 and Pakt/AKT in cEPCs harvested from T2DM, treated with insulin metformin plus. This study showed that treatment with insulin plus metformin in diabetic patients is associated with increased mobilization of EPCs into the circulation, with potential beneficial effect in vascular protection in diabetic patients.