Phytochemical composition and in vitro biological activities of Morinda citrifolia fruit juice

Morinda citrifolia is a plant with broad nutraceutical and therapeutic effects and used in the traditional treatment of several ailments. The objective of this work is to investigate the phytochemistry of the fruit juice of M. citrifolia on one hand and on other hand to evaluate its antiradical and antibacterial activity. The phytochemical investigation was carried out by tube staining tests of the extract of two types of fruit juice of M. citrifolia. The antioxidant activity of these juices was evaluated by reducing the DPPH radical method. Concerning the antibacterial activity, it was tested on the in vitro growth of 10 reference bacterial strains using the well diffusion method. Qualitative phytochemistry of M. citrifolia fruit juices revealed the presence of large groups of secondary metabolites including polyphenols, reducing compounds, mucilage and terpernoids. The antioxidant activity of M. citrifolia fruit juices is dose-dependent and higher than that of ascorbic acid. Antimicrobial activity on other hand revealed that fruit juices inhibit growth inhibitory activity of Staphylococcus aureus, Pseudomonas aeruginosa, Proteus mirabilis, S. epidermidis, Proteus vulgaris, Streptococcus oralis, Enterococcus faecalis and Escherichia coli. This observed difference is significant for each juices on the strains (p < 0.001). These results support the use of M. citrifolia in traditional medicine and are the starting points for the development of a new drug to combat both dietary conditions and chronic conditions associated with oxidative stress.     

<Emphasis Type="Italic">KNOX</Emphasis> overexpression in transgenic <Emphasis Type="Italic">Kohleria</Emphasis> (Gesneriaceae) prolongs the activity of proximal leaf blastozones and drastically alters segment fate

KNOX (knotted1-like homeobox) genes have a widely conserved role in the generation of dissected leaves. Ectopic KNOX activity in leaves in various angiosperm lineages causes leaf form changes that can elucidate how the configuration of leaf development evolved. We present an analysis of leaf morphology and morphogenesis in transgenic Kohleria lines overexpressing a heterologous KNOX gene. Kohleria, like many members of Gesneriaceae, has simple-serrated leaves with pinnate venation. KNOX overexpression causes prolonged segment proliferation in proximal, but not distal, parts of leaf blades. Elaborate dissected segments reiterate the zonation of the whole leaf, with organogenic activity persisting between a distal maturation zone and a proximal intercalary elongation zone. The architecture of vascular bundles is severely altered, with a reduced midvein and a more palmate venation. The initial establishment of organogenically competent primordial margins (marginal blastozones) and the onset of tissue differentiation in early stages of leaf development were similar in wild-type and KNOX overexpressing lines. However, leaves overexpressing KNOX often failed to fully mature, and persistent marginal blastozones were found at the base of blades in mature portions of the shoot. We conclude that KNOX-mediated perpetuation of marginal blastozones in Kohleria is sufficient to induce a set of processes that result in highly dissected leaflets, which are unusual in this plant family. Spatial confinement of blastozones between an early maturing tip and a late elongating petiole zone reflects the presence of distinct maturation processes that limit the ability of the leaf margins to respond to ectopic KNOX gene expression.     

Aquaporin 4 in Traumatic Brain Injury: From Molecular Pathways to Therapeutic Target

Traumatic brain injury (TBI) is known as an acute degenerative pathology of the central nervous system, and has been shown to increase brain aquaporin 4 (AQP4) expression. Various molecular mechanisms affect AQP4 expression, including neuronal high mobility group box 1, forkhead box O3a, vascular endothelial growth factor, hypoxia-inducible factor-1 α (HIF-1 α) sirtuin 2, NF-κB, Malat1, nerve growth factor and Angiotensin II receptor type 1. In addition, inhibition of AQP4 with FK-506, MK-801 (indirectly by targeting N-methyl-d-aspartate receptor), inactivation of adenosine A2A receptor, levetiracetam, adjudin, progesterone, estrogen, V1aR inhibitor, hypertonic saline, erythropoietin, poloxamer 188, brilliant blue G, HIF-1alpha inhibitor, normobaric oxygen therapy, astaxanthin, epigallocatechin-3-gallate, sesamin, thaliporphine, magnesium, prebiotic fiber, resveratrol and omega-3, as well as AQP4 gene silencing lead to reduced edema upon TBI. This review summarizes current knowledge and evidence on the relationship between AQP4 and TBI, and the potential mechanisms involved.

     

The role of organic synthesis in glycoconjugate research: selected examples

Chemical synthesis of various oligosaccharides allowed the determination of structural requirements for specific interaction between heparin and anti-thrombin III. The synthesis of a sialylated tetrasaccharide, subunit of the human blood group Cad determinant, is also reported.     

Potential small‐molecule drugs as available weapons to fight novel coronavirus (2019‐nCoV): A review

Since the new coronavirus known as 2019‐nCoV (severe acute respiratory syndrome coronavirus 2, SARS‐CoV‐2) has widely spread in Wuhan, China, with severe pneumonia, scientists and physicians have made remarkable efforts to use various options such as monoclonal antibodies, peptides, vaccines, small‐molecule drugs and interferon therapies to control, prevent or treatment infections of 2019‐nCoV. However, no vaccine or drug has yet been confirmed to completely treat 2019‐nCoV. In this review, we focus on the use of potential available small‐molecule drug candidates for treating infections caused by 2019‐nCoV.     

Lessons,narratives, and research directions for a sustainable circular economy

The current enthusiasm for the circular economy (CE) offers a unique opportunity to advance the impact of research on sustainability transitions. Diverse interpretations of CE by scholars, however, produce partly opposing assessments of its potential benefits, which can hinder progress. Here, we synthesize policy-relevant lessons and research directions for a sustainable CE and identify three narratives—optimist, reformist, and skeptical—that underpin the ambiguity in CE assessments. Based on 54 key CE scholars’ insights, we identify three research needs: the articulation and discussion of ontologically distinct CE narratives; bridging of technical, managerial, socio-economic, environmental, and political CE perspectives; and critical assessment of opportunities and limits of CE science–policy interactions. Our findings offer practical guidance for scholars to engage reflexively with the rapid expansion of CE knowledge, identify and pursue high-impact research directions, and communicate more effectively with practitioners and policymakers.     

The Sumo proteome of proliferating and neuronal-differentiating cells reveals Utf1 among key Sumo targets involved in neurogenesis

Post-translational modification by covalent attachment of the Small ubiquitin-like modifier (Sumo) polypeptide regulates a multitude of processes in vertebrates. Despite demonstrated roles of Sumo in the development and function of the nervous system, the identification of key factors displaying a sumoylation-dependent activity during neurogenesis remains elusive. Through a SILAC (stable isotope labeling by/with amino acids in cell culture)-based proteomic approach, we have identified the Sumo proteome of the model cell line P19 under proliferation and neuronal differentiation conditions. More than 300 proteins were identified as putative Sumo targets differentially associated with one or the other condition. A group of proteins of interest were validated and investigated in functional studies. Among these, Utf1 was revealed as a new Sumo target. Gain-of-function experiments demonstrated marked differences between the effects on neurogenesis of overexpressing wild-type and sumoylation mutant versions of the selected proteins. While sumoylation of Prox1, Sall4a, Trim24, and Utf1 was associated with a positive effect on neurogenesis in P19 cells, sumoylation of Kctd15 was associated with a negative effect. Prox1, Sall4a, and Kctd15 were further analyzed in the vertebrate neural tube of living embryos, with similar results. Finally, a detailed analysis of Utf1 showed the sumoylation dependence of Utf1 function in controlling the expression of bivalent genes. Interestingly, this effect seems to rely on two mechanisms: sumoylation modulates binding of Utf1 to the chromatin and mediates recruitment of the messenger RNA-decapping enzyme Dcp1a through a conserved SIM (Sumo-interacting motif). Altogether, our results indicate that the combined sumoylation status of key proteins determines the proper progress of neurogenesis.Subject terms: Enzyme mechanisms, Cell signalling, Chromatin, Sumoylation     

Synthése du 6-O-β-D-Galactofuranosyl-D-galactopyranose

6-O-β-D-Galactofuranosyl-D-galactose was obtained in crystalline form by condensation of 3,5,6-tri-O-acetyl-1,2-O-(1-methoxyethylidene)-α-D-galactofuranose with benzyl 2,3,4-tri-O-benzyl-α-D-galactopyranoside, followed by O-deacetylation and catalytic hydrogenation. This compound is identical with that isolated from the cell wall of Mycobacterium tuberculosis by partial acid hydrolysis.     

Bacterial superantigens in human disease: structure, function and diversity

All bacterial superantigens use common structural strategies to bind to major histocompatibility complex class II receptors, while binding the T cell antigen receptor in different ways.

Overstimulation of the immune response is responsible for the acute pathological effects, while reactivation of developmentally silenced T cells might result in autoimmune disease. Certain diseases might be controlled with superantigens or genetically attenuated vaccines.