Characteristics of dibenzothiophene desulfurization by Rhodococcus erythropolis R1 and its Dsz-negative mutant

Introduction: Biodesulfurization is used as a selective method for lowering the sulfur content of petroleum products. Materials and methods: A sulfur-oxidation bacterial strain named Rhodococcus erythropolis R1 (NCBI GenBank Accession No. GU570564) was used in this study for desulfurization of dibenzothiophene (DBT). Results: The induced culture of strain R1 was able to produce 2-hydroxybiphenyl (2- HBP) from DBT followed 4S pathway without further degrading carbon backbone. This process confirmed by gas chromatography (GC) analysis. The specific activity of DBT desulfurization by R1 was 45 µM (g dry wt)-1 h-1. The addition of Tween 80 as surfactant and glycerol as carbon source determines a 100% rate of DBT-desulfurization during 3 days. The heavy plasmid detected in R1 strain carries dsz genes responsible for biodesulfurization of DBT that was shown by PCR reaction. The mutant strains which had lost this plasmid also had lost desulfurization phenotype. Both mutant and wild strain were sensitive to high concentration of 2-HBP and some antibiotics. Discussion and conclusion: Strain R1 desulfurize DBT through the sulfur-specific degradation pathway or 4S pathway with the selective cleavage of carbon-sulfur (C-S) bonds without reducing the energy content. Addition of surfactant enhanced the desulfurization of DBT by increasing its bioavailability and also could improve the growth and desulfurization rate. The location of desulfurization genes was on a heavy plasmid in strain R1. Based on the results of this study, R. erythropolis R1 could serve as a model system for efficient biodesulfurization of petroleum oil without reducing the energy value

Effect of Plant Oils upon Lipase and Citric Acid Production in Yarrowia lipolytica Yeast

The nonconventional yeast Yarrowia lipolytica degrades very efficiently hydrophobic substrates to produce organic acids, single-cell oil, lipases, and so forth. The aim of this study was to investigate the biochemical behavior and simultaneous production of valuable metabolites such as lipase, citric acid (CA), and single-cell protein (SCP) by Yarrowia lipolytica DSM 3286 grown on various plant oils as sole carbon source. Among tested plant oils, olive oil proved to be the best medium for lipase and CA production. The Y. lipolytica DSM 3286 produced 34.6 ± 0.1 U/mL of lipase and also CA and SCP as by-product on olive oil medium supplemented with yeast extract. Urea, as organic nitrogen, was the best nitrogen source for CA production. The results of this study suggest that the two biotechnologically valuable products, lipase and CA, could be produced simultaneously by this strain using renewable low-cost substrates such as plant oils in one procedure

Biased Treg/Th17 balance away from regulatory toward inflammatory phenotype in relapsed multiple sclerosis and its correlation with severity of symptoms

The opposing immune functions of Treg and Th17 lymphocytes and the plasticity of Treg/Th17 differentiation, has led us to investigate the effects of their fluctuations and counterbalance in autoimmune condition of multiple sclerosis (MS). Evaluation of Treg and Th17 frequency in peripheral blood of a group of relapsed MS patients, showed a decrease in Treg/Th17 ratio compared to that of healthy controls. A reverse correlation between these subsets was observed in controls but not in patient groups. Both Treg frequency and Treg/Th17 ratio were negatively correlated with severity of symptoms. There was shown to be an enduring increase in Treg frequency associated with MS disease

Leptin promotes melanoma tumor growth in mice related to increasing circulating endothelial progenitor cells numbers and plasma NO production

<p>Abstract</p> <p>Background</p> <p>Epidemiological studies propose that obesity increases the risk of several cancers, including melanoma. Obesity increases the expression of leptin, a multifunctional peptide produced predominantly by adipocytes which may promote tumor growth. Several recently experiments have suggested that the tumors growth is in need of endothelial progenitor cell (EPC) dependent generation of new blood vessels.</p> <p>Our objectives in the present study were to examine the effects of leptin on melanoma growth, circulating EPCs number and plasma levels of nitric oxide metabolites (NOx).</p> <p>Methods</p> <p>2 × 10⁶B16F10 melanoma cells were injected to thirty two C57BL6 mice subcutaneously. The mice were randomly divided into 4 groups (n = 8) in 8th day. Two groups were received twice daily intraperitoneal(i.p) injections of either PBS or recombinant murine leptin (1 μg/g initial body weight). Two groups were received i.p. injections of either 9F8 an anti leptin receptor antibody or the control mouse IgG at 50 μg/mouse every 3 consecutive days. By the end of the second week the animals were euthanized and blood samples and tumors were analyzed.</p> <p>Results</p> <p>The tumor weight, EPC numbers and NOx level in leptin, PBS, 9F8, and IgG group were (3.2 ± 0.6, 1.7 ± 0.3, 1.61 ± 0.2,1.7 ± 0.3 g), (222.66 ± 36.5, 133.33 ± 171, 23.33 ± 18, 132.66 ± 27.26/ml of blood), and (22.47 ± 5.5, 12.30 ± 1.5, 6.26 ± 0.84, 15.75 ± 6.3 μmol/L) respectively. Tumors weight and size, circulating EPC numbers and plasma levels of NOx were significantly more in the leptin than 9f8 and both control groups (p < 0.05). The plasma concentration of NOx significantly decreased in 9f8 treated mice compare to control group (p < 0.05).</p> <p>Conclusions</p> <p>In conclusion, our observations indicate that leptin causes melanoma growth likely through increased NO production and circulating EPC numbers and consequently vasculogenesis.</p

Recognition of Cytokeratin 18 Marker by Flow Cytometry of Nucleus Pulposus Cells in Human Intervertebral Disc and Comparison of Proliferation and Morphology of these Cells in Chitosan-Gelatin and Alginate Scaffolds

Background: Low back pain is a major economical and social problem nowadays. Intervertebral disc herniation and central degeneration of disc are two major reasons of low back pain that occur because of structural impairment of discs. Intervertebral disc includes the annulus fibrosus, transitional region, and nucleus pulposus (NP). NP forms the central nucleus of the disc. Reduction of cell count and extracellular matrix, especially in NP, causes disc degeneration. Different scaffolds (natural and synthetic) have been used for tissue repairing and regeneration of intervertebral disc in tissue engineering. Most scaffolds have biodegradable and biocompatible characteristics and also prepare a fine condition for proliferation and migration of cells. Although no specific marker or method has been suggested for recognition of NP cells, some studies have used real time and immunocytochemical methods and reported high expression of cytokeratin 19, 18, 8, and others as markers for NP cells. This study aimed to recognize NP cells of human intervertebral disc by flow cytometry of cytokeratin 18 marker. It also compared the proliferation and morphology of these cells in chitosan-gelatin scaffold and alginate scaffold. Methods: NP cells were derived by enzymatic hydrolysis of collagenase from NP tissue of patients undergoing open surgery for discectomy in Alzahra Hospital (Isfahan, Iran). Chitosan was blended with gelatin and glutaraldehyde was used for cross linking of the two polymers. Then, alginate scaffold was prepared. After approving the NP cells by flow cytometry of cytokeratin 18 marker, a cellular suspension with 4 × 105 cells was transferred to each scaffold and cultured for 21 days. Cell viability and proliferation were investigated by trypan blue and methyl thiazolyl tetrazolium (MTT) assay. A scanning electron microscope (SEM) was used to assert the porosity and to survey the structures of the scaffolds. Findings: We can use flow cytometry of cytokeratin 18 markers for recognition of NP cells. MTT assay demonstrated that cell viability on the third day had significant difference with the first day in both scaffolds. There was also a significant reduction in cellular viability from day 3 to day 21. Results of cell count showed that mean difference between cell counts in alginate scaffold was significantly more than chitosan-gelatin scaffold (P < 0.001). Conclusion: Flow cytometry of cytokeratin 18 can be used as a method for recognition of NP cells. Compared to chitosan-gelatin scaffold, alginate scaffold prepared a better condition for proliferation of NP cells. The results of this study suggested that alginate scaffold could be useful in in-vivo studies and treatment

Toll like receptor 2 and 4 expression in peripheral blood mononuclear cells of multiple sclerosis patients

Background: Multiple sclerosis (MS) is a T cell mediated autoimmune disease with unknown etiology. Appropriate MS therapeutic strategies need thorough understanding of both disease etiology and pathogenesis mechanisms. Ligation of TLR-2 and TLR-4 stimulates the production of several cytokines leading to CNS autoimmunity and neurodegenerative diseases. Objective: To find a relationship between MS disability and TLR-2 and TLR-4 expression on mononuclear cells in the blood of MS patients. Methods: Forty-five new case (NC) MS patients (33 females and 12 males) and 45 age and gender-matched healthy controls (HC) were recruited to the study. PBMCs were prepared and the expressions of TLR-2 and TLR-4 were assessed by flowcytometry technique using appropriate monoclonal antibodies. Results: Our results showed that the expression of TLR-2 and TLR-4 proteins in the patients group was significantly higher than that of healthy controls. TLR-2 but not TLR-4 was correlated with expanded disability status scale (EDSS) scores. Conclusion: High expressions of TLR-2 and TLR-4 may represent a state of innate immune activation in patients with MS. © 2014, Shiraz University of Medical Sciences

Cytokine gene expression in newly diagnosed multiple sclerosis patients

Multiple Sclerosis (MS) is characterized by multiple areas of inflammation, demyelination and neurodegeneration. Infiltrating Th1 CD4+ T cells secrete proinflammatory cytokines. They stimulate the release of some cytokines, expression of adhesion molecules and these cytokines may cause damage to the myelin sheath and axons. In this study, we analyzed plasma levels and gene expressions of five important cytokines in the new diagnosed MS Patients by ELISA and Real time PCR. PCR amplifications were performed to determine the IL-17, IL-23, IL-10, IL-27 and TGF-β mRNA expression levels using the SYBR Green PCR Kit. Our results showed significant decrease in IL-10, IL-27 and TGF-β but there was no significant difference in the IL-17 and IL-23 between patients and healthy controls. Altogether, our results indicated that dysregulation of cytokines, mainly increased expression of pro-inflammatory cytokines and decreased expression of inhibitory cytokines occurred in MS patients. This study may shed light to the probable role of these cytokines in neurodegeneration mechanism and current or future use of cytokines in managing and treatment of multiple sclerosis

Evaluation of the leptin receptor in human spermatozoa

<p>Abstract</p> <p>Background</p> <p>Leptin, a 167 amino acid peptide hormone, profoundly effects reproduction exerting its biological effects via interaction with the leptin receptor (ObR) which is widely expressed on peripheral tissues. In this study, we have attempted to assess leptin receptor expression in the spermatozoa of fertile males and those diagnosed with male factor infertility; both at the mRNA or protein levels.</p> <p>Methods</p> <p>Semen samples were collected from fertile males and individuals with male factor infertility. In order to evaluate leptin receptor expression several techniques were utilized, including: reverse transcriptase-polymerase chain reaction (RT-PCR), immunostaining, flow cytometry, and western blotting. Mononuclear cells isolated from volunteers' peripheral blood were used as positive controls for leptin receptor expression.</p> <p>Results</p> <p>leptin receptor was noted on mononuclear cells but we were unable to detect this receptor on spermatozoa at the protein level. Leptin receptor expression was detected on peripheral blood mononuclear cells (PBMCs) as positive controls; however it was not detectable on the spermatozoa of both groups by immunofluorescence microscopy or flow cytometry. Furthermore, positive expression of the ObR long isoform as assessed by RT-PCR was observed in the sperm of only four cases, whereas expression of beta-Actin, a house keeping gene, and HspA2, a testis specific gene, was present in all cases.</p> <p>Conclusion</p> <p>The long isoform of leptin receptor may not be present on human sperm. Species difference may be accounted for diverse reproductive physiology which depends on metabolic requirement. Leptin receptor expression at the mRNA level in some individuals may be related to contamination by other cells in semen.</p

Differential Expression of CD16 and CD56 on Natural Killer (NK) Cell Subsets in Multiple Sclerosis and Neuromyelitis Optica

Background: Multiple sclerosis (MS) and Neuromyelitis optica (NMO) are inflammatory and demyelinating diseases of the central nervous system (CNS). NK cells are supposed to play an important role in the pathophysiology of MS, but their role in the NMO remains unknown. The aim of this study was to compare the prevalence of different subpopulations of NK cells in the patients with MS and NMO and healthy individuals. Methods: Treatment Naive MS and NMO patients, age, and sex matched controls were included in this study. PBMCs were isolated from peripheral blood and different phenotypes of circulating NK cells were compared with the flow cytometry analysis. Results: There were no significant differences in the mean percentages of circulating NK cells expressing the CD56 bright molecule in patients with MS and NMO. However, the mean percentages of circulating NK cells expressing the CD56bright molecule were significantly lower in all patients groups, compared to controls. In addition, the mean percentages of circulating NK cells expressing the CD16dim molecule was significantly higher in the patients with MS, compared to controls/any other groups. The mean percentages of circulating NK cells expressing the CD56dim molecule were significantly higher in the patients with MS than the controls. There were significant differences in the mean percentages of circulating NK cells expressing the CD16bright molecule between the patients with MS, and NMO/controls. Conclusions: The results indicate that evaluation of NK cell subsets has an implication for the biomarker discovery and therapeutic targets in given diseases