A novel link between angiogenesis and natural products: Anti-angiogenic effects of Opuntia dillenii

Angiogenesis is the formation of new blood vessels from the existing blood vessels and is involved in both physiological and pathological events. Pathological angiogenesis provokes in several important diseases as in inflammatory diseases, ischemic conditions, diabetic neuropathy and cancer. The discovery of new drugs from phyto-chemicals has a long history and anti-angiogenic agents from plant sources provide a platform for the development of phyto-medicines to treat/control pathological angiogenesis. The current project was designed to determine the efficacy of different concentrations of aqueous extract from Opuntia dillenii (OD) on angiogenesis by employing chicken chorioallantoic membrane (CAM) assay. Computer based 3D image probing was utilized to quantify anti-angiogenic effects of OD extract. Extremely aggravated dose dependent anti-angiogenic response was recorded in all groups treated with OD extract with significant reduction (P<0.01) in total area, diameter of the primary, secondary, tertiary blood vessels and capillary plexuses. Analysis of 3D parameters of OD treated CAMs revealed deteriorated angular spectrum and reduction in the height of Abbott curves. In addition, histological data revealed thinning of ectodermal layer and damaged extracellular matrix. The results spotlight that OD extract possess considerable anti-angiogenic potential and further characterization/isolation of diverse phyto-chemicals would turn up with the discovery of novel phyto-agents to control/mitigate pathological angiogenesis.     

Production of β-carotene from deproteinized waste whey filtrate using Mucor azygosporus MTCC 414 in submerged fermentation

The cheese whey, a by-product of dairy industry proved to be an attractive substrate for production of β-carotene. The β-carotene production from Mucor azygosporus MTCC 414 by using deproteinized waste whey filtrate under submerged fermentation was investigated. Various fermentation variables, such as lactose content in whey, initial pH, production temperature, incubation time, and carbon and nitrogen sources played significant role on β-carotene production. Maximum β-carotene production (385 μg/g dcw) was obtained with the whey (pH 5.5) containing 3.5% (w/v) lactose supplemented with soluble starch at (1.0%, w/v) at 30°C after a 5 days incubation. Moreover, unlike other microorganisms which utilize pre-hydrolyzed lactose, this Mucor azygosporus MTCC 414 was found to be capable of utilizing unhydrolyzed lactose present in the whey.     

Expression and characterization of <Emphasis Type="Italic">Trichoderma virens</Emphasis> UKM-1 endochitinase in <Emphasis Type="Italic">Escherichia</Emphasis> <Emphasis Type="Italic">coli</Emphasis>

A gene encoding endochitinase from Trichoderma virens UKM-1 was cloned and expressed in E. coli BL21 (DE3). Both the endochitinase gene and its cDNA sequences were obtained. The endochitinase gene encodes 430 amino acids from an open reading frame comprising of 1,690 bp nucleotide sequence with three introns. The endochitinase was expressed as soluble and active enzyme at 20°C when induced with 1 mM IPTG. Maximum activity was observed at 4 h of post-induction time. SDS-PAGE showed that the purified endochitinase exhibited a single band with molecular weight of 42 kDa. Biochemical characterization of the enzyme displayed a near neutral pH characteristic with an optimum pH at 6.0 and optimum temperature at 50°C. The enzyme is stable between pH 3.0–7.0 and is able to retain its activity from 30 to 60°C. The presence of Mg²⁺ and Ca²⁺ ions increased the enzyme activity up to 20%. The purified enzyme has a strong affinity towards colloidal chitin and low effect on ethyl cellulose and D-cellubiose which are non-chitin related substrates. HPLC analysis from the chitin hydrolysis showed the release of (GlcNAc)₃, (GlcNAc)₂ and GlcNAc, in which (GlcNAc)₂ was the main product.     

Native Enzyme Mobility Shift Assay (NEMSA): a new method for monitoring carboxyl group modification of carboxymethylcellulase from Aspergillus niger

A simple, sensitive, accurate and more informative assay for determining the number of modified groups during the course of carboxyl group modification is described. Monomeric carboxymethylcellulase (CMCase) from Aspergillus niger was modified by 1-ethyl-3(3-dimethylaminopropyl)carbodiimide (EDC) in the presence of glycinamide. The different time-course aliquots were subjected to non-denaturing PAGE and the gel stained for CMCase activity. The number of carboxyl groups modified are directly read from the ladder of the enzyme bands developed at given time. This method showed that after 75 min of modification reaction there were five major species of modified CMCases in which 6 to 10 carboxyls were modified.     

Site-directed chemically-modified magnetic enzymes: fabrication,improvements, biotechnological applications and future prospects

Numerous enzymes of biotechnological importance have been immobilized on magnetic nanoparticles (MNP) via random multipoint attachment, resulting in a heterogeneous protein population with potential reduction in activity due to restriction of substrate access to the active site. Several chemistries are now available, where the modifier can be linked to a single specific amino acid in a protein molecule away from the active-site, thus enabling free access of the substrate. However, rarely these site-selective approaches have been applied to immobilize enzymes on nanoparticles. In this review, for the first time, we illustrate how to adapt site-directed chemical modification (SDCM) methods for immobilizing enzymes on iron-based MNP. These strategies are mainly chemical but may additionally require genetic and enzymatic methods. We critically examine each method and evaluate their scope for simple, quick, efficient, mild and economical immobilization of enzymes on MNP. The improvements in the catalytic properties of few available examples of immobilized enzymes are also discussed. We conclude the review with the applications and future prospects of site-selectively modified magnetic enzymes and potential benefits of this technology in improving enzymes, including cold-adapted homologues, modular enzymes, and CO₂-sequestering, as well as non-iron based nanomaterials.     

Plant growth-promoting Bacillus sp. strain SDA-4 confers Cd tolerance by physio-biochemical improvements,better nutrient acquisition and diminished Cd uptake in Spinacia oleracea L.

Cadmium (Cd) is highly toxic metal for plant metabolic processes even in low concentration due to its longer half-life and non-biodegradable nature. The current study was designed to assess the bioremediation potential of a Cd-tolerant phytobeneficial bacterial strain Bacillus sp. SDA-4, isolated, characterized and identified from Chakera wastewater reservoir, Faisalabad, Pakistan, together with spinach (as a test plant) under different Cd regimes. Spinach plants were grown with and without Bacillus sp. SDA-4 inoculation in pots filled with 0, 5 or 10 mg kg⁻¹ CdCl₂-spiked soil. Without Bacillus sp. SDA-4 inoculation, spinach plants exhibited reduction in biomass accumulation, antioxidative enzymes and nutrient retention. However, plants inoculated with Bacillus sp. SDA-4 revealed significantly augmented growth, biomass accumulation and efficiency of antioxidative machinery with concomitant reduction in proline and MDA contents under Cd stress. Furthermore, application of Bacillus sp. SDA-4 assisted the Cd-stressed plants to sustain optimal levels of essential nutrients (N, P, K, Ca and Mg). It was inferred that the characterized Cd-tolerant PGPR strain, Bacillus sp. SDA-4 has a potential to reduce Cd uptake and lipid peroxidation which in turn maintained the optimum balance of nutrients and augmented the growth of Cd-stressed spinach. Analysis of bioconcentration factor (BCF) and translocation factor (TF) revealed that Bacillus sp. SDA-4 inoculation with spinach sequestered Cd in rhizospheric zone. Research outcomes are important for understanding morpho-physio-biochemical attributes of spinach-Bacillus sp. SDA-4 synergy which might provide efficient strategies to decrease Cd retention in edible plants and/or bioremediation of Cd polluted soil colloids.     

LXR/ApoE Activation Restricts Innate Immune Suppression in Cancer

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Evolutionary significance of selected EDAR variants in Tibetan high-altitude adaptations

Humans have been exposed to many environmental challenges since their evolutionary origins in Africa and subsequent migrations to the rest of the world. A severe environmental challenge to human migrants was hypoxia caused by low barometric oxygen pressure at high altitudes. Several genome-wide scans have elucidated the genetic basis of human high-altitude adaptations.However, the dearth of functional variant information has led to the successful association of only a few candidate genes. In the present study, we employed a candidate gene approach and re-sequenced the EDAR locus in 45 Tibetan individuals to identify mutations involved in hypoxia adaptation. We identified 10 and five quantitative trait-associated mutations for oxygen saturation (SaO_2) and blood platelet count, respectively, at the EDAR locus. Among these, rs10865026 and rs3749110 (associated with SaO_2 and platelet count, respectively) were identified as functional candidate targets. These data demonstrate that EDAR has undergone natural selection in recent human history and indicate an important role of EDAR variants in Tibetan high-altitude adaptations.