Aged‐senescent cells contribute to impaired heart regeneration

Aging leads to increased cellular senescence and is associated with decreased potency of tissue‐specific stem/progenitor cells. Here, we have done an extensive analysis of cardiac progenitor cells (CPCs) isolated from human subjects with cardiovascular disease, aged 32–86 years. In aged subjects (>70 years old), over half of CPCs are senescent (p16^INK4A, SA‐β‐gal, DNA damage γH2AX, telomere length, senescence‐associated secretory phenotype [SASP]), unable to replicate, differentiate, regenerate or restore cardiac function following transplantation into the infarcted heart. SASP factors secreted by senescent CPCs renders otherwise healthy CPCs to senescence. Elimination of senescent CPCs using senolytics abrogates the SASP and its debilitative effect in vitro. Global elimination of senescent cells in aged mice (INK‐ATTAC or wild‐type mice treated with D + Q senolytics) in vivo activates resident CPCs and increased the number of small Ki67‐, EdU‐positive cardiomyocytes. Therapeutic approaches that eliminate senescent cells may alleviate cardiac deterioration with aging and restore the regenerative capacity of the heart.     

Molecular designing,virtual screening and docking study of novel curcumin analogue as mutation (S769L and K846R) selective inhibitor for EGFR

The somatic mutations in ATP binding cleft of the tyrosine kinase binding domain of EGFR are known to occur in 15–40% of non-small cell lung cancer (NSCLC) patients. Although first and second generation anti-EGFR inhibitors are widely used to treat these patients, their therapeutic efficacy is modest and often results in adverse effects or drug resistance. Therefore, there is a need to develop novel as well as safe anti-EGFR drugs. The rapid emergence of computational drug designing provided a great opportunity to both discover and predict the efficacy of novel EGFR inhibitors from plant sources. In the present study, we designed several chemical analogues of edible curcumin (CUCM) compound and assessed their drug likeliness, ADME and toxicity properties using a diverse range of advanced computational methods. We also have examined the structural plasticity and binding characteristics of EGFR wild-type and mutant forms (S769L and K846R) against ligand molecules like Gefitinib, native CUCM, and different CUCM analogues. Through multidimensional experimental approaches, we conclude that CUCM-36 ((1E,4Z,6E)-1-(3,4-Diphenoxyphenyl)-5-hydroxy-7-(4-hydroxy-3-phenoxyphenyl)-1,4,6-heptatrien-3-one) is the best anti-EGFR compound with high drug-likeness, ADME properties, and low toxicity properties. CUCM-36 compound has demonstrated better affinity towards both wild-type (ΔG is ?8.5?kcal/Mol) and mutant forms (V769L & K846R; ΔG for both is >?9.20?kcal/Mol) compared to natural CUCM and Gefitinib inhibitor. This study advises the future laboratory assays to develop CUCM-36 as a novel drug compound for treating EGFR positive non-small cell lung cancer patients.     

Computational aspects of feedback in neural circuits

It has previously been shown that generic cortical microcircuit models can perform complex real-time computations on continuous input streams, provided that these computations can be carried out with a rapidly fading memory. We investigate the computational capability of such circuits in the more realistic case where not only readout neurons, but in addition a few neurons within the circuit, have been trained for specific tasks. This is essentially equivalent to the case where the output of trained readout neurons is fed back into the circuit. We show that this new model overcomes the limitation of a rapidly fading memory. In fact, we prove that in the idealized case without noise it can carry out any conceivable digital or analog computation on time-varying inputs. But even with noise, the resulting computational model can perform a large class of biologically relevant real-time computations that require a nonfading memory. We demonstrate these computational implications of feedback both theoretically, and through computer simulations of detailed cortical microcircuit models that are subject to noise and have complex inherent dynamics. We show that the application of simple learning procedures (such as linear regression or perceptron learning) to a few neurons enables such circuits to represent time over behaviorally relevant long time spans, to integrate evidence from incoming spike trains over longer periods of time, and to process new information contained in such spike trains in diverse ways according to the current internal state of the circuit. In particular we show that such generic cortical microcircuits with feedback provide a new model for working memory that is consistent with a large set of biological constraints. Although this article examines primarily the computational role of feedback in circuits of neurons, the mathematical principles on which its analysis is based apply to a variety of dynamical systems. Hence they may also throw new light on the computational role of feedback in other complex biological dynamical systems, such as, for example, genetic regulatory networks.     

Efficacy of salicylic acid in modulating physiological andbiochemical mechanisms to improve postharvest longevity in cut spikes of Consolida ajacis (L.) Schur.

Postharvest losses of cut flowers is one of the considerable challenges restricting their efficient marketability. Consequently, such challenges have triggered a constant hunt for developing compatible postharvest treatments to mitigate postharvest losses. Interestingly, recent studies entrench extensive role of salicylic acid (SA) in mitigating postharvest losses in various flower systems. The current investigation focusses on role of SA in augmenting physiological and biochemical responses to mitigate postharvest senescence in cut spikes of Consolida ajacis. The cut spikes of C. ajacis were supplemented with various SA treatments viz, 2 mM, 4 mM, 6 mM. The effects of these treatments were evaluated against control set of spikes placed in distilled water. Our study indicates considerable increment in postharvest longevity of cut spikes, besides an increase in solution uptake, sugar and protein content of tepal tissues.SA augmented antioxidant system via upsurge in phenolic content and antioxidant enzymes viz, superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) to forfend reactive oxygen species (ROS) related oxidative damage. SA profoundly reduced lipoxygenase (LOX) activity to preserve the membrane integrity and thus prevented seepage of solutes from tepal tissues. These results authenticate SA particularly 4 mM concentration as effective postharvest treatment to preserve the postharvest quality of C. ajacis cut spikes.     

Comparative pulmonary toxicity of cadmium and nickel: histopathological and bronchoalveolar lavage analysis

Pulmonary toxicity of cadmium and nickel was evaluated in rat lungs following intratracheal instillation of their chlorides. Concentration of both the metals varied from 0.2-5 mM. Both the metals increased total number of cells, number of polymorphonuclear neutrophils, total protein, sialic acid and the activity of lactate dehydrogenase and beta-glucuronidase in bronchoalveolar lavage 3 days after exposure. Increase in the levels of the selected parameters was more following Cd exposure than in Ni exposed rats. Histologically there was an inflammatory response and interstitial fibroblastic proliferation in the lungs of Cd exposed animals. These changes were mild in Ni-exposed animals and higher concentrations of Ni were needed to produce changes similar to those produced by smaller concentrations of Cd.     

Decolorization and detoxification of extraction-stage effluent from chlorine bleaching of kraft pulp by Rhizopus oryzae

Rhizopus oryzae, a zygomycete, was found to decolorize, dechlorinate, and detoxify bleach plant effluent at lower cosubstrate concentrations than the basidiomycetes previously investigated. With glucose at 1 g/liter, this fungus removed 92 to 95% of the color, 50% of the chemical oxygen demand, 72% of the adsorbable organic halide, and 37% of the extractable organic halide in 24 h at temperatures of 25 to 45 degrees C and a pH of 3 to 5. Even without added cosubstrate the fungus removed up to 78% of the color. Monomeric chlorinated aromatic compounds were removed almost completely, and toxicity to zebra fish was eliminated. The fungal mycelium could be immobilized in polyurethane foam and used repeatedly to treat batches of effluent. The residue after treatment was not further improved by exposure to fresh R. oryzae mycelium.     

Biological bleaching of chemical pulps

Use of biotechnology in pulp bleaching has attracted considerable attention and achieved interesting results in recent years. Enzymes of the hemicellulolytic type, particularly xylan-attacking enzymes, xylanases are now used commercially in the mills for pulp treatment and subsequent incorporation into bleach sequences. The aims of the enzymatic treatment depend on the actual mill conditions and may be related to environmental demands, reduction of chemical costs or maintenance or even improvement of product quality. The use of oxidative enzymes from white-rot fungi, that can directly attack lignin, is a second-generation approach, which could produce larger chemical savings than xylanase but has not yet been developed to the full scale. It is being studied in several laboratories in Canada, Japan, the U.S.A. and Europe. Certain white-rot fungi can delignify kraft pulps increasing their brightness and their responsiveness to brightening with chemicals. The fungal treatments are too slow but the enzyme manganese peroxidase and laccase can also delignify pulps and enzymatic processes are likely to be easier to optimize and apply than the fungal treatments. Development work on laccase and manganese peroxidase continues. This article presents an overview of developments in the application of hemicellulase enzymes, lignin-oxidizing enzymes and white-rot fungi in bleaching of chemical pulps. The basic enzymology involved and the present knowledge of the mechanisms of the action of enzymes as well as the practical results and advantages obtained on the laboratory and industrial scale are discussed.     

Residues of VP26 of herpes simplex virus type 1 that are required for its interaction with capsids

VP26 is the smallest capsid protein and decorates the outer surface of the capsid shell of herpes simplex virus. It is located on the hexons at equimolar amounts with VP5. Its small size (112 amino acids) and high copy number make it an attractive molecule to use as a probe to investigate the complex pattern of capsid protein interactions. An in vitro capsid binding assay and a green fluorescent protein (GFP) localization assay were used to identify VP26 residues important for its interaction with capsids. To test for regions of VP26 that may be essential for binding to capsids, three small in-frame deletion mutations were generated in VP26, Delta18-25, Delta54-60, and Delta93-100. Their designations refer to the amino acids deleted by the mutation. The mutation at the C terminus of the molecule, which encompasses a region of highly conserved residues, abolished binding to the capsid and the localization of GFP to the nucleus in characteristic large puncta. Additional mutations revealed that a region of VP26 spanning from residue 50 to 112 was sufficient for the localization of the fused protein (VP26-GFP) to the nucleus and for it to bind to capsids. Using site-directed mutagenesis of conserved residues in VP26, two key residues for protein-protein interaction, F79 and G93, were identified as judged by the localization of GFP to nuclear puncta. When these mutations were analyzed in the capsid binding assay, they were also found to eliminate binding of VP26 to the capsid structure. Surprisingly, additional mutations that affected the ability of VP26 to bind to capsids in vitro were uncovered. Mutations at residues A58 and L64 resulted in a reduced ability of VP26 to bind to capsids. Mutation of the hydrophobic residues M78 and A80, which are adjacent to the hydrophobic residue F79, abolished VP26 capsid binding. In addition, the block of conserved amino acids in the carboxy end of the molecule had the most profound effect on the ability of VP26 to interact with capsids. Mutation of amino acid G93, L94, R95, R96, or T97 resulted in a greatly diminished ability of VP26 to bind capsids. Yet, all of these residues other than G93 were able to efficiently translocate or concentrate GFP into the nucleus, giving rise to the punctate fluorescence. Thus, the interaction of VP26 with the capsid appears to occur through at least two separate mechanisms. The initial interaction of VP26 and VP5 may occur in the cytoplasm or when VP5 is localized in the nucleus. Residues F79 and G93 are important for this bi-molecular interaction, resulting in the accumulation of VP26 in the nucleus in concentrated foci. Subsequent to this association, additional amino acids of VP26, including those in the C-terminal conserved domain, are important for interaction of VP26 with the three-dimensional capsid structure.     

Biophoton emission of a lichen species Parmelia tinctorum

The properties of biophoton signals emitted by samples of lichen species P. tinctorum are investigated. The shape of a light induced signal is determined from 5 ms onwards using successively the bin resolution of 1, 10 and 100 ms; 1000 measurements in successive bins are made at each resolution. The measurement of the shape is repeated at various temperatures in the range (1 degree-40 degrees C) in steps of 1 degree C. It is found that a biophoton signal is very sensitive to temperature and different portions of the signal show different sensitivity. The temperature dependence of the decaying part is even qualitatively different from that of the non-decaying part. The signal responds to temperature changes of 0.1 degrees C in less than 1 ms. The effect of monochromatic stimulation on the strengths of the signal and its red, blue and green spectral components are determined in the wavelength range (400-700) nm in steps of 10 nm. The signal and its broad spectral components have similar excitation curves. The relative strength of spectral component appears independent of the stimulating wavelength. The shape of the decaying portion of the signal and its red, blue and green components is also determined. The character of decay in all four cases is non-exponential. The measurements with various interference filters spanning the entire visible region are made with the bin size of 20 s. These measurements are qualitative because of large fluctuations but suggest that the spectral components of a biophoton signal are distributed in the entire visible region. The probabilities of detecting different number of photons in the non-decaying portion are determined by making 30,000 measurements in each set with the bin size of 50, 100, 200, 300, 400, 500 and 700 ms. The probabilities determine the parameters of a squeezed state of light--the magnitude of its displacement parameter is different but the phase of its displacement parameter and its squeezing parameter are same for different sizes of a bin. These measurements further indicate that the average signal strength remains constant for 19 hr.