Profiles of Serum Cytokines in Acute Drug-Induced Liver Injury and Their Prognostic Significance

Drug-induced liver injury (DILI) is the most common cause of acute liver failure in the United-States. The aim of the study was to describe serum immune profiles associated with acute DILI, to investigate whether there are profiles associated with clinical features or types of DILI and/or with prognosis, and to assess temporal changes in levels. Twenty-seven immune analytes were measured in the sera of 78 DILI subjects in the Drug-Induced Liver Injury Network (DILIN) and compared with 40 healthy controls. Immune analytes (14 cytokines, 7 chemokines and 6 growth factors) were measured by BioPlex multiplex ELISA at DILI onset and after 6 months. A modeling process utilizing immune principles was used to select a final set of variables among 27 immune analytes and several additional clinical lab values for prediction of early death (within 6 months of DILI onset). Nineteen of the 27 immune analytes were differentially expressed among healthy control, DILI onset and 6-month cohorts. Disparate patterns of immune responses, especially innate and adaptive cellular (mostly TH17) immunity were evident. Low values of four immune analytes (IL-9, IL-17, PDGF-bb and RANTES) and serum albumin are predictive of early death [PPV = 88% (95% CI, 65%-100%), NPV = 97% (95% CI, 93%-100%), accuracy = 96% (95% CI, 92%-100%)].

Conclusions

Acute DILI is associated with robust and varying immune responses. High levels of expression of cytokines associated with innate immunity are associated with a poor prognosis, whereas high levels of expression of adaptive cytokines are associated with good long-term prognosis and eventual recovery. Serum immune analyte profiles at DILI onset appear to be of prognostic, and perhaps, diagnostic significance.     

Purification and biochemical characterization of a highly active cysteine protease ervatamin A from the latex of Ervatamia coronaria

Ervatamia coronaria, a flowering plant (family Apocynaceae) indigenous to India, has medicinally important applications. A search for biochemical constituents of the latex of the plant yielded at least three thiol proteases with distinctly different properties. One of them, a highly active protease (ervatamin A), was purified to homogeneity by ion exchange and gel filtration chromatography. The enzyme exhibited high proteolytic activity toward natural substrates and amidolytic activity toward synthetic substrates. The pH and temperature optima for proteolytic activity were 8–8.5 and 50–55°C, respectively. Proteolytic activity of the enzyme was strongly inhibited by thiol-specific inhibitors. The estimated molecular mass of the enzyme was 27.6 kDa. The extinction coefficient (1% 280) of the enzyme was estimated as 21.9, and the protein molecule consists of 8 tryptophan, 11 tyrosine and 7 cysteine residues. Isoelectric point of the purified enzyme was 8.37. Polyclonal antibodies raised against the pure enzyme gave a single precipitin line in Ouchterlony's double immunodiffusion and a typical color in ELISA. The N-terminal sequence of the enzyme showed conserved amino acid residues to other plant cysteine proteases. Ervatamin A shows high activity in relation to the other thiol proteases isolated from the same source.     

Foraging ecology of aphidophagous predators against Aphis punicae Passerini

Foraging behaviour of three aphidophagous predators, viz., Cheilomenes sexmaculata (Fabricius), Scymnus sp. (Coleoptera: Coccinellidae) and Paragus serratus (Fabricius) (Diptera: Syrphidae) on prey Aphis punicae Passerini (Homoptera: Aphididae) was studied in the laboratory at Indian Institute of Horticultural Research, Bangalore (12 degrees 58' N; 77 degrees 35'E) during 2002-03 to understand the predation dynamics. The foraging studies of grubs of C. sexmaculata and Scymnus sp. on A. punicae revealed that the distance travelled to reach the food (aphids) was negatively correlated with the feeding time of prey (r = -0.434 and -0.743, respectively). The time taken for second encounter was positively correlated with feeding time in case of both C. sexmaculata (r = 0.715) and P.serratus (r = 0.641). The time taken for first encounter of prey by Scymnus sp. showed negative correlation with the feeding time (r = -0.9491) and positive correlation with the distance traveled by the predator to reach the food (r = 0.620). The foraging behavioural studies of syrphid, P. serratus on A. punicae showed that the time taken for first encounter of prey was positively correlated with both the feeding time (r = 0.467) and the distance travelled by the syrphid to reach the food (r = 0.485). The time taken for first encounter of prey also showed significant positive correlation with the search time of the prey (r = 0.384).     

N-cadherin-mediated cell adhesion restricts cell proliferation in the dorsal neural tube

Neural progenitors are organized as a pseudostratified epithelium held together by adherens junctions (AJs), multiprotein complexes composed of cadherins and α- and β-catenin. Catenins are known to control neural progenitor division; however, it is not known whether they function in this capacity as cadherin binding partners, as there is little evidence that cadherins themselves regulate neural proliferation. We show here that zebrafish N-cadherin (N-cad) restricts cell proliferation in the dorsal region of the neural tube by regulating cell-cycle length. We further reveal that N-cad couples cell-cycle exit and differentiation, as a fraction of neurons are mitotic in N-cad mutants. Enhanced proliferation in N-cad mutants is mediated by ligand-independent activation of Hedgehog (Hh) signaling, possibly caused by defective ciliogenesis. Furthermore, depletion of Hh signaling results in the loss of junctional markers. We therefore propose that N-cad restricts the response of dorsal neural progenitors to Hh and that Hh signaling limits the range of its own activity by promoting AJ assembly. Taken together, these observations emphasize a key role for N-cad-mediated adhesion in controlling neural progenitor proliferation. In addition, these findings are the first to demonstrate a requirement for cadherins in synchronizing cell-cycle exit and differentiation and a reciprocal interaction between AJs and Hh signaling.     

Resolvin D1 prevents TNF-α-mediated disruption of salivary epithelial formation

Sj?gren's syndrome is a chronic autoimmune disorder characterized by inflammation of salivary glands resulting in impaired secretory function. Our present studies indicate that chronic exposure of salivary epithelium to TNF-α and/or IFN-γ alters tight junction integrity, leading to secretory dysfunction. Resolvins of the D-series (RvDs) are endogenous lipid mediators derived from DHA that regulate excessive inflammatory responses leading to resolution and tissue homeostasis. In this study, we addressed the hypothesis that activation of the RvD1 receptor ALX/FPR2 in salivary epithelium prevents and/or resolves the TNF-α-mediated disruption of acinar organization and enhances monolayer formation. Our results indicate that 1) the RvD1 receptor ALX/FPR2 is present in fresh, isolated cells from mouse salivary glands and in cell lines of salivary origin; and 2) the agonist RvD1 (100 ng/ml) abolished tight junction and cytoskeletal disruption caused by TNF-α and enhanced cell migration and polarity in salivary epithelium. These effects were blocked by the ALX/FPR2 antagonist butyloxycarbonyl-Phe-Leu-Phe-Leu-Phe. The ALX/FPR2 receptor signals via modulation of the phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathways since, in our study, blocking PI3K activation with LY294002, a potent and selective PI3K inhibitor, prevented RvD1-induced cell migration. Furthermore, Akt gene silencing with the corresponding siRNA almost completely blocked the ability of Par-C10 cells to migrate. Our findings suggest that RvD1 receptor activation promotes resolution of inflammation and tissue repair in salivary epithelium, which may have relevance in the restoration of salivary gland dysfunction associated with Sj?gren's syndrome.     

Carbohydrate Hydrolysis and Transport in the Extreme Thermoacidophile Sulfolobus solfataricus

Extremely thermoacidophilic microbes, such as Sulfolobus solfataricus, are strict chemoheterotrophs despite their geologic niche. To clarify their ecophysiology, the overlapping roles of endoglucanases and carbohydrate transporters were examined during growth on soluble cellodextrins as the sole carbon and energy source. Strain-specific differences in genome structure implied a unique role for one of three endogenous endoglucanases. Plasmid-based endoglucanase expression promoted the consumption of oligosaccharides, including cellohexaose (G6) through cellonanaose (G9). Protein transporters required for cellodextrin uptake were identified through mutagenesis and complementation of an ABC transporter cassette, including a putative oligosaccharide binding protein. In addition, ablation of the binding protein compromised growth on glucose and alpha-linked oligosaccharides while inactivation of a previously described glucose transporter had no apparent impact. These data demonstrate that S. solfataricus employs a redundant mechanism for soluble cellodextrin catabolism having both substrate uptake and extracytoplasmic hydrolytic components.     

Serotonin circuits and anxiety: what can invertebrates teach us?

Fear, a reaction to a threatening situation, is a broadly adaptive feature crucial to the survival and reproductive fitness of individual organisms. By contrast, anxiety is an inappropriate behavioral response often to a perceived, not real, threat. Functional imaging, biochemical analysis, and lesion studies with humans have identified the HPA axis and the amygdala as key neuroanatomical regions driving both fear and anxiety. Abnormalities in these biological systems lead to misregulated fear and anxiety behaviors such as panic attacks and post-traumatic stress disorders. These behaviors are often treated by increasing serotonin levels at synapses, suggesting a role for serotonin signaling in ameliorating both fear and anxiety. Interestingly, serotonin signaling is highly conserved between mammals and invertebrates. We propose that genetically tractable invertebrate models organisms, such as Drosophila melanogaster and Caenorhabditis elegans, are ideally suited to unravel the complexity of the serotonin signaling pathways. These model systems possess well-defined neuroanatomies and robust serotonin-mediated behavior and should reveal insights into how serotonin can modulate human cognitive functions.     

Promise(s) of Mesenchymal Stem Cells as an In Vitro Model System to Depict Pre-Diabetic/Diabetic Milieu in WNIN/GR-Ob Mutant Rats

Background

Development of model systems have helped to a large extent, in bridging gap to understand the mechanism(s) of disease including diabetes. Interestingly, WNIN/GR-Ob rats (Mutants), established at National Centre for Laboratory Animals (NCLAS) of National Institute of Nutrition (NIN), form a suitable model system to study obesity with Type 2 diabetes (T2D) demonstrating several secondary complications (cataract, cardiovascular complications, infertility, nephropathy etc). The present study has been carried out to explore the potent application(s) of multipotent stem cells such as bone marrow mesenchymal stem cells (BM-MSCs), to portray features of pre-diabetic/T2D vis-à-vis featuring obesity, with impaired glucose tolerance (IGT), hyperinsulinemia (HI) and insulin resistance (IR) seen with Mutant rats akin to human situation.

Methodology/Principal Findings

Primary cultures of BM-MSCs (third passage) from Mutants, its lean littermate (Lean) and parental control (Control) were characterized for: proliferation markers, disease memory to mark obesity/T2D/HI/IR which included phased gene expression studies for adipogenic/pancreatic lineages, inflammatory markers and differentiation ability to form mature adipocytes/Insulin-like cellular aggregates (ILCAs). The data showed that BM-MSCs from Mutant demonstrated a state of disease memory, depicted by an upregulated expression of inflammatory markers (IL-6, TNFα); increased stem cell recruitment (Oct-4, Sox-2) and proliferation rates (CD90+/CD29+, PDA, ‘S’ phase of cell cycle by FACS and BrdU incorporation); accelerated preadipocyte induction (Dact-1, PPARγ2) with a quantitative increase in mature adipocyte formation (Leptin); ILCAs, which were non-responsive to high glucose did confer the Obese/T2D memory in Mutants. Further, these observations were in compliance with the anthropometric data.

Conclusions

Given the ease of accessibility and availability of MSCs, the present study form the basis to report for the first time, application of BM-MSCs as a feasible in vitro model system to portray the disease memory of pre-clinical/T2D with IR - a major metabolic disorder of global concern.     

Bio-Fuel Crops Research for Energy Security and Rural Development in Developing Countries

Soaring prices of fossil fuels, geo-political issues and environmental pollution associated with fossil fuel use has led to worldwide interest in the production and use of bio-fuels. Both the developed and developing countries have developed a range of policies to encourage production of combustible fuels from plants that triggered public and private investments in bio-fuel crop research and development, and bio-fuels production. In this article, we discuss the potential benefits of bio-fuels in increasing the farmers’ incomes, reducing environment pollution, the crop options and research and development interventions required to generate feedstocks to produce bio-fuels to meet projected demand without compromising food/fodder security in developing countries.