Evaluation of cytotoxic,antifungal, and larvicidal activities of different bis-sulfonamide Schiff base compounds

Schiff bases (imines or azomethines) are versatile ligands synthesized from the condensation of amino compounds with active carbonyl groups and used for many pharmaceutical and medicinal applications. In our study, we aimed to determine the cytotoxic, antifungal and larvicidal activities of biologically potent bis-sulfonamide Schiff base derivatives that were re-synthesized by us. For this aim, 16 compounds were re-synthesized and tested for their cytotoxic, antifungal and larvicidal properties. Among this series, compounds A1B2 , A1B4 , A4B2 , A4B3 , and A4B4 were shown to have cytotoxic activity against tested cancer lung cell line (A549). The most potent antifungal activity was observed in compounds A2B1 and A2B2 against all fungi. A1B1 showed the strongest larvicidal effect at all concentrations at the 72nd h (100% mortality). These obtained results demonstrate that these type of bis-substituted compounds might be used as biologically potent pharmacophores against different types of diseases.     

The Human EKC/KEOPS Complex Is Recruited to Cullin2 Ubiquitin Ligases by the Human Tumour Antigen PRAME

The human tumour antigen PRAME (preferentially expressed antigen in melanoma) is frequently overexpressed during oncogenesis, and high PRAME levels are associated with poor clinical outcome in a variety of cancers. However, the molecular pathways in which PRAME is implicated are not well understood. We recently characterized PRAME as a BC-box subunit of a Cullin2-based E3 ubiquitin ligase. In this study, we mined the PRAME interactome to a deeper level and identified specific interactions with OSGEP and LAGE3, which are human orthologues of the ancient EKC/KEOPS complex. By characterizing biochemically the human EKC complex and its interactions with PRAME, we show that PRAME recruits a Cul2 ubiquitin ligase to EKC. Moreover, EKC subunits associate with PRAME target sites on chromatin. Our data reveal a novel link between the oncoprotein PRAME and the conserved EKC complex and support a role for both complexes in the same pathways.     

Characterization and properties of biosurfactants produced by a newly isolated strain <Emphasis Type="Italic">Bacillus methylotrophicus</Emphasis> DCS1 and their applications in enhancing solubility of hydrocarbon

Six biosurfactant-producing bacteria were isolated from hydrocarbon contaminated soils in Sfax, Tunisia. Isolates were screened for biosurfactant production by different conventional methods including hemolytic activity, surface tension reduction, drop-collapsing and oil displacement tests. All these screening tests show that all the isolates behave differently. Among the isolated bacteria, DCS1 strain was selected for further studies based on its highest activities and it was identified as Bacillus methylotrophicus DCS1. This strain was found to be a potent producer of biosurfactant when cultivated in mineral-salts medium supplemented with diesel oil (2 %, v/v) as a sole carbon source. Physicochemical properties and stability of biosurfactants synthesized by B. methylotrophicus DCS1 were investigated. The produced biosurfactants DCS1, from Landy medium, possess high surface activity that could lower the surface tension of water to a value of 31 from 72 mN m^?1 and have a critical micelle concentration (CMC) of 100 mg L^?1. Compared with SDS and Tween 80, biosurfactants showed excellent emulsification activities against different hydrocarbon substrates and high solubilization efficiency towards diesel oil. Biosurfactants DCS1 showed good stability in a wide range of temperature, pH and salinity. These results suggested that biosurfactants produced by B. methylotrophicus DCS1 could be an alternative to chemically synthesized surfactants for use in bioremediation processes to enhance the solubility of hydrophobic compounds.     

Cytoglobin: a potential marker for adipogenic differentiation in preadipocytes in vitro

Obesity, mainly characterized by the excess fat storage, is a global health problem resulting in serious morbidity and mortality. Identification of molecular mechanisms in adipogenic differentiation pathway might lead to development of new strategies for diagnosis, prevention and therapy of obesity and associated diseases. Discovery of new genes and proteins in the differentiation pathway could help to understand the key specific regulators of the adipogenesis. Cytoglobin (Cygb), identified as a new globin family member protein, is expressed in various tissues. Although its interaction with oxygen and nitric oxide indicates the potential role in antioxidant pathways, the exact role remains unclear. In the current study, expression level of Cygb was determined in proliferating and differentiating 3T3-F442A cells by gene expression and protein expression analysis. Results revealed that Cygb expression up-regulated in differentiated cells in parallel with adipogenic differentiation markers; PPARγ, CEBPα and FABP4 expressions. Besides, Cygb overexpression in preadipocytes contributed to the adipogenic differentiation as verified by detection of higher lipid droplets and increased PPARγ, CEBPα and FABP4 expressions with respect to control cells. These findings will shed light on the unknown roles of Cygb in adipogenesis and obesity.     

Morphology and anatomy of root nodules of Retama monosperma (L.)Boiss.

Background and aims

In spite of the importance of Retama species for dune stabilization and re-vegetation and the contribution to the bio-fertilization of semi-arid and arid ecosystems, the symbiotic interaction of Retama species with rhizobia remains largely unstudied. In this paper, we aim to provide the first detailed study on nodule morphology and anatomy of Retama monosperma.

Methods

We collected nodules from coastal areas nearby Oran (Algeria) and studied in detail their anatomy and ultrastructure by light and electron microscopy.

Results

First, we confirmed the likely identity of the microsymbiont as B. retamae and found that nodules of R. monosperma belong to the genistoid type of indeterminate nodules. Infection threads, typical for most nodules of legumes, are absent in nodules of R. monosperma and bacterial spread is associated with plant cell division. The nitrogen fixation zone is homogenous with only invaded cells and a network of non-invaded cells found in many nodules, is absent. Moreover, endoreduplication does not take place in bacteroids in nodules of R. monosperma.

Conclusions

The features observed in this study are compared to the morphology and anatomy of nodules of other legumes and the possible consequences for nodule functioning and the mode of infection during the establishment of the interaction are discussed.     

Determination of antimicrobial properties of Picaridin and DEET against a broad range of microorganisms

Insect repellents are topically applied to the skin and clothing of human and pet to keep flies, mosquitoes, and ticks away. Two important repellents, N,N-diethyl-meta-toluamide (DEET) and Picaridin, have been widely used since their discovery. Although repellency and toxicological effects of DEET and Picaridin on human being and insects are well documented without understanding molecular mechanisms, there have been no attempts to study their effects on microorganisms up to now. In the current study, DEET and Picaridin have been investigated for their antimicrobial characteristics against a broad range of microorganisms including bacteria, yeast, and fungi for the first time. They exhibited considerable antibacterial, anticandidal and antifungal properties. Even though bacteria was found to be more sensitive to Picaridin, yeast and fungi were more susceptible to DEET. Antimicrobial properties of these two repellents will increase the usage and application areas of the products containing DEET and Picaridin.     

Semaphorin 3F and Neuropilin-2 Control the Migration of Human T-Cell Precursors

Neuropilins and semaphorins are known as modulators of axon guidance, angiogenesis, and organogenesis in the developing nervous system, but have been recently evidenced as also playing a role in the immune system. Here we describe the expression and role of semaphorin 3F (SEMA3F) and its receptor neuropilin-2 (NRP2) in human T cell precursors. NRP2 and SEMA3F are expressed in the human thymus, in both lymphoid and non-lymphoid compartments. SEMA3F have a repulsive effect on thymocyte migration and inhibited CXCL12- and sphingosine-1-phosphate (S1P)-induced thymocyte migration by inhibiting cytoskeleton reorganization prior to stimuli. Moreover, NRP2 and SEMA3F are expressed in human T-cell acute lymphoblastic leukemia/lymphoma primary cells. In these tumor cells, SEMA3F also blocks their migration induced by CXCL12 and S1P. Our data show that SEMA3F and NRP2 are further regulators of human thymocyte migration in physiological and pathological conditions.