Systemic DNA damage accumulation under in vivo tumor growth can be inhibited by the antioxidant Tempol

Recently we found that mice bearing subcutaneous non-metastatic tumors exhibited elevated levels of two types of complex DNA damage, i.e., double-strand breaks and oxidatively-induced clustered DNA lesions in various tissues throughout the body, both adjacent to and distant from the tumor site. This DNA damage was dependent on CCL2, a cytokine involved in the recruitment and activation of macrophages, suggesting that this systemic DNA damage was mediated via tumor-induced chronic inflammatory responses involving cytokines, activation of macrophages, and consequent free radical production. If free radicals are involved, then a diet containing an antioxidant may decrease the distant DNA damage. Here we repeated our standard protocol in cohorts of two syngeneic tumor-bearing C57BL/6NCr mice that were on a Tempol-supplemented diet. We show that double-strand break and oxidatively-induced clustered DNA lesion levels were considerably decreased, about two- to three fold, in the majority of tissues studied from the tumor-bearing mice fed the antioxidant Tempol compared to the control tumor-bearing mice. Similar results were also observed in nude mice suggesting that the Tempol effects are independent of functioning adaptive immunity. This is the first in vivo study demonstrating the effect of a dietary antioxidant on abscopal DNA damage in tissues distant from a localized source of genotoxic stress. These findings may be important for understanding the mechanisms of genomic instability and carcinogenesis caused by chronic stress-induced systemic DNA damage and for developing preventative strategies.

Osteopontin-CD44v6 interaction mediates calcium deposition via phospho-Akt in valve interstitial cells from patients with noncalcified aortic valve sclerosis

OBJECTIVE

The activation of valve interstitial cells (VICs) toward an osteogenic phenotype characterizes aortic valve sclerosis, the early asymptomatic phase of calcific aortic valve disease. Osteopontin is a phosphorylated acidic glycoprotein that accumulates within the aortic leaflets and labels VIC activation even in noncalcified asymptomatic patients. Despite this, osteopontin protects VICs against in vitro calcification. Here, we hypothesize that the specific interaction of osteopontin with CD44v6, and the related intracellular pathway, prevents calcium deposition in human-derived VICs from patients with aortic valve sclerosis.

APPROACH AND RESULTS

On informed consent, 23 patients and 4 controls were enrolled through the cardiac surgery and heart transplant programs. Human aortic valves and VICs were tested for osteogenic transdifferentiation, ex vivo and in vitro. Osteopontin-CD44 interaction was analyzed using proximity ligation assay and the signaling pathways investigated. A murine model based on angiotensin II infusion was used to mimic early pathological remodeling of the aortic valves. We report osteopontin-CD44 functional interaction as a hallmark of early stages of calcific aortic valve disease. We demonstrated that osteopontin-CD44 interaction mediates calcium deposition via phospho-Akt in VICs from patients with noncalcified aortic valve sclerosis. Finally, microdissection analysis of murine valves shows increased cusp thickness in angiotensin II-treated mice versus saline infused along with colocalization of osteopontin and CD44 as seen in human lesions.

CONCLUSIONS

Here, we unveil a specific protein-protein association and intracellular signaling mechanisms of osteopontin. Understanding the molecular mechanisms of early VIC activation and calcium deposition in asymptomatic stage of calcific aortic valve disease could open new prospective for diagnosis and therapeutic intervention.

The three CARMA sisters: so different, so similar: a portrait of the three CARMA proteins and their involvement in human disorders

Initially identified by their ability to modulate the functional activity of BCL10, the three CARMA proteins, CARMA1, -2, and -3, have recently themselves taken a leading role on the stage of molecular medicine. Although considered for some time as simple ancillary proteins, increasingly accumulating recent data evidently indicate a role of primary importance for these three proteins in the pathophysiology of several human tumors and inflammatory disorders. In fact, recent scientific literature clearly establishes that CARMA1 is one of the most mutated genes in a subtype of B-cell lymphoma and, at the same time, responsible for some rare human immunodeficiency conditions. On the other hand, mutations in CARMA2 are responsible for the hereditary transmission of some inflammatory disorders of the skin, including familial psoriasis and ptiriasis; whereas expression of CARMA3 appears to be deregulated in different human tumors. Here we describe and summarize the mutations found in the genes coding for the three CARMA proteins in these different human pathological conditions, and offer an interpretation of the molecular mechanisms from which arise the biological outcomes in which these proteins are involved.

PID15, a novel 6 kDa secreted peptide, mediates Naja naja venom phospholipase A₂ induced apoptosis in isolated human peripheral lymphocytes

Background

Snake venoms are a complex mixture of active principles mainly peptides and proteins also including amino acids, nucleotides, free lipids, carbohydrates and metallic elements bound to proteins that interfere in several biological systems. In this study, we aimed to understand the mode of action of the apoptosis inducing ability of Naja naja venom phospholipase A₂ (NV-PLA₂) using isolated human peripheral lymphocytes.

Results

Human peripheral lymphocytes when incubated with Naja naja venom phospholipase A₂ (NV-PLA₂) induced up to 68% DNA fragmentation. The dialysed conditioned media obtained by incubating lymphocytes with NV-PLA₂ at 15^th min induced 44% DNA fragmentation, referred to as cmlp-active. Cmlp-active showed 20.5% increased protein concentration than the corresponding control condition media cmlp-c-15. Test for creatine kinase activity in cmlp-active proved negative and negligible amount of lactate dehydrogenase did not show significant DNA fragmentation. Fractionation of cmlp-active on Sephadex G-25 showed two peaks, major peak induced 38% DNA fragmentation, which was further rechromatographed on Sephadex G-25. The single peak obtained was named PID15 (Phospholipase A₂Induced DNA fragmentation factor secreted at 15^th min). Q-Tof MS/MS analysis of PID-15 showed it is a 6 kDa peptide. PID15 sequence analysis gave 40 amino acids in the following order, msilpcknvs iwvikdtaas dkevvlgsdr aikflylatg. The homology search for the sequence revealed it to be an Apoptosis Inducing Factor (AIF).

Conclusion

Results indicate that the secretion of PID15 is dependent on concentration of NV-PLA₂ treatment, incubation time and also on temperature and the probable membrane origin of PID15 and not of cytosolic origin with apoptosis inducing ability.

Autophagy and microRNA dysregulation in liver diseases

Autophagy is a catabolic process through which organelles and cellular components are sequestered into autophagosomes and degraded via fusion with lysosomes. Autophagy plays a role in many physiological processes, including stress responses, energy homeostasis, elimination of cellular organelles, and tissue remodeling. In addition, autophagy capacity changes in various disease states. A series of studies have shown that autophagy is strictly controlled to maintain homeostatic balance of energy metabolism and cellular organelle and protein turnover. These studies have also shown that this process is post-transcriptionally controlled by small noncoding microRNAs that regulate gene expression through complementary base pairing with mRNAs. Conversely, autophagy regulates the expression of microRNAs. Therefore, dysregulation of the link between autophagy and microRNA expression exacerbates the pathogenesis of various diseases. In this review, we summarize the roles of autophagy and microRNA dysregulation in the course of liver diseases, with the aim of understanding how microRNAs modify key autophagic effector molecules, and we discuss how this dysregulation affects both physiological and pathological conditions. This article may advance our understanding of the cellular and molecular bases of liver disease progression and promote the development of strategies for pharmacological intervention.

Plasma membrane Ca2+-ATPase isoforms composition regulates cellular pH homeostasis in differentiating PC12 cells in a manner dependent on cytosolic Ca2+ elevations

Plasma membrane Ca²⁺-ATPase (PMCA) by extruding Ca²⁺ outside the cell, actively participates in the regulation of intracellular Ca²⁺ concentration. Acting as Ca²⁺/H⁺ counter-transporter, PMCA transports large quantities of protons which may affect organellar pH homeostasis. PMCA exists in four isoforms (PMCA1-4) but only PMCA2 and PMCA3, due to their unique localization and features, perform more specialized function. Using differentiated PC12 cells we assessed the role of PMCA2 and PMCA3 in the regulation of intracellular pH in steady-state conditions and during Ca²⁺ overload evoked by 59 mM KCl. We observed that manipulation in PMCA expression elevated pH_mito and pH_cyto but only in PMCA2-downregulated cells higher mitochondrial pH gradient (ΔpH) was found in steady-state conditions. Our data also demonstrated that PMCA2 or PMCA3 knock-down delayed Ca²⁺ clearance and partially attenuated cellular acidification during KCl-stimulated Ca²⁺ influx. Because SERCA and NCX modulated cellular pH response in neglectable manner, and all conditions used to inhibit PMCA prevented KCl-induced pH drop, we considered PMCA2 and PMCA3 as mainly responsible for transport of protons to intracellular milieu. In steady-state conditions, higher TMRE uptake in PMCA2-knockdown line was driven by plasma membrane potential (Ψp). Nonetheless, mitochondrial membrane potential (Ψm) in this line was dissipated during Ca²⁺ overload. Cyclosporin and bongkrekic acid prevented Ψ_m loss suggesting the involvement of Ca²⁺-driven opening of mitochondrial permeability transition pore as putative underlying mechanism. The findings presented here demonstrate a crucial role of PMCA2 and PMCA3 in regulation of cellular pH and indicate PMCA membrane composition important for preservation of electrochemical gradient.

The intracellular redox protein MICAL-1 regulates the development of hippocampal mossy fibre connections

Mical is a reduction-oxidation (redox) enzyme that functions as an unusual F-actin disassembly factor during Drosophila development. Although three Molecule interacting with CasL (MICAL) proteins exist in vertebrate species, their mechanism of action remains poorly defined and their role in vivo unknown. Here, we report that vertebrate MICAL-1 regulates the targeting of secretory vesicles containing immunoglobulin superfamily cell adhesion molecules (IgCAMs) to the neuronal growth cone membrane through its ability to control the actin cytoskeleton using redox chemistry, thereby maintaining appropriate IgCAM cell surface levels. This precise regulation of IgCAMs by MICAL-1 is essential for the lamina-specific targeting of mossy fibre axons onto CA3 pyramidal neurons in the developing mouse hippocampus in vivo. These findings reveal the first in vivo role for a vertebrate MICAL protein, expand the repertoire of cellular functions controlled through MICAL-mediated effects on the cytoskeleton, and provide insights into the poorly characterized mechanisms underlying neuronal protein cell surface expression and lamina-specific axonal targeting.

Histone deacetylase inhibition with trichostatin A does not reverse severe angioproliferative pulmonary hypertension in rats (2013 Grover Conference series)

Pulmonary arterial hypertension (PAH) is a rapidly progressive and devastating disease characterized by remodeling of lung vessels, increased pulmonary vascular resistance, and eventually right ventricular hypertrophy and failure. Because histone deacetylase (HDAC) inhibitors are agents hampering tumor growth and cardiac hypertrophy, they have been attributed a therapeutic potential for patients with PAH. Outcomes of studies evaluating the use of HDAC inhibitors in models of PAH and right ventricular pressure overload have been equivocal, however. Here we describe the levels of HDAC activity in the lungs and hearts of rats with pulmonary hypertension and right heart hypertrophy or failure, experimentally induced by monocrotaline (MCT), the combined exposure to the VEGF-R inhibitor SU5416 and hypoxia (SuHx), and pulmonary artery banding (PAB). We show that HDAC activity levels are reduced in the lungs of rat with experimentally induced hypertension, whereas activity levels are increased in the hypertrophic hearts. In contrast to what was previously found in the MCT model, the HDAC inhibitor trichostatin A had no effect on pulmonary vascular remodeling in the SuHx model. When our results and those in the published literature are taken together, it is suggested that the effects of HDAC inhibitors in humans with PAH and associated RV failure are, at best, unpredictable. Significant progress can perhaps be made by using more specific HDAC inhibitors, but before clinical tests in human PAH can be undertaken, careful preclinical studies are required to determine potential cardiotoxicity.

Store-operated Ca2+ entry does not control proliferation in primary cultures of human metastatic renal cellular carcinoma

Store-operated Ca²⁺ entry (SOCE) is activated following depletion of the inositol-1,4,5-trisphosphate (InsP₃)-sensitive Ca²⁺ pool to regulate proliferation in immortalized cell lines established from either primary or metastatic lesions. The molecular nature of SOCE may involve both Stim1, which senses Ca²⁺ levels within the endoplasmic reticulum (ER) Ca²⁺ reservoir, and a number of a Ca²⁺-permeable channels on the plasma membrane, including Orai1, Orai3, and members of the canonical transient receptor (TRPC1–7) family of ion channels. The present study was undertaken to assess whether SOCE is expressed and controls proliferation in primary cultures isolated from secondary lesions of heavily pretreated metastatic renal cell carcinoma (mRCC) patients. SOCE was induced following pharmacological depletion of the ER Ca²⁺ store, but not by InsP₃-dependent Ca²⁺ release. Metastatic RCC cells express Stim1-2, Orai1–3, and TRPC1–7 transcripts and proteins. In these cells, SOCE was insensitive to BTP-2, 10 µM Gd³⁺ and Pyr6, while it was inhibited by 100 µM Gd³⁺, 2-APB, and carboxyamidotriazole (CAI). Neither Gd³⁺ nor 2-APB or CAI impaired mRCC cell proliferation. Consistently, no detectable Ca²⁺ signal was elicited by growth factor stimulation. Therefore, a functional SOCE is expressed but does not control proliferation of mRCC cells isolated from patients resistant to multikinase inhibitors.

Modeling pharmacokinetics/pharmacodynamics of abatacept and disease progression in collagen-induced arthritic rats: a population approach

The PK/PD of abatacept, a selective T cell co-stimulation modulator, was examined in rats with collagen-induced arthritis (CIA) using a nonlinear mixed effect modeling approach. Male Lewis rats underwent collagen induction to produce rheumatoid arthritis. Two single-dose groups received either 10 mg/kg intravenous (IV) or 20 mg/kg subcutaneous (SC) abatacept, and one multiple-dose group received one 20 mg/kg SC abatacept dose and four additional 10 mg/kg SC doses. Effects on disease progression (DIS) were measured by paw swelling. Plasma concentrations of abatacept were assayed by enzyme-linked immunosorbent assay. The PK/PD data were sequentially fitted using NONMEM VI. Goodness-of-fit was assessed by objective functions and visual inspection of diagnostic plots. The PK of abatacept followed a two-compartment model with linear elimination. For SC doses, short-term zero-order absorption was assumed with F = 59.2 %. The disease progression component was an indirect response model with a time-dependent change in paw edema production rate constant (k in ) that was inhibited by abatacept. Variation in the PK data could be explained by inter-individual variability in clearance and central compartment volume (V 1 ), while the large variability of the PD data may be the result of paw edema production (k in 0 ) and loss rate constant (k out ). Abatacept has modest effects on paw swelling in CIA rats. The PK/PD profiles were well described by the proposed model and allowed evaluation of inter-individual variability on drug- and DIS-related parameters.

Adult vascular smooth muscle cells in culture express neural stem cell markers typical of resident multipotent vascular stem cells

Differentiation of resident multipotent vascular stem cells (MVSCs) or de-differentiation of vascular smooth muscle cells (vSMCs) might be responsible for the SMC phenotype that plays a major role in vascular diseases such as arteriosclerosis and restenosis. We examined vSMCs from three different species (rat, murine and bovine) to establish whether they exhibit neural stem cell characteristics typical of MVSCs. We determined their SMC differentiation, neural stem cell marker expression and multipotency following induction in vitro by using immunocytochemistry, confocal microscopy, fluorescence-activated cell sorting analysis and quantitative real-time polymerase chain reaction. MVSCs isolated from rat aortic explants, enzymatically dispersed rat SMCs and rat bone-marrow-derived mesenchymal stem cells served as controls. Murine carotid artery lysates and primary rat aortic vSMCs were both myosin-heavy-chain-positive but weakly expressed the neural crest stem cell marker, Sox10. Each vSMC line examined expressed SMC differentiation markers (smooth muscle α-actin, myosin heavy chain and calponin), neural crest stem cell markers (Sox10(+), Sox17(+)) and a glia marker (S100β(+)). Serum deprivation significantly increased calponin and myosin heavy chain expression and decreased stem cell marker expression, when compared with serum-rich conditions. vSMCs did not differentiate to adipocytes or osteoblasts following adipogenic or osteogenic inductive stimulation, respectively, or respond to transforming growth factor-β1 or Notch following γ-secretase inhibition. Thus, vascular SMCs in culture express neural stem cell markers typical of MVSCs, concomitant with SMC differentiation markers, but do not retain their multipotency. The ultimate origin of these cells might have important implications for their use in investigations of vascular proliferative disease in vitro.

Insulin protects pancreatic acinar cells from palmitoleic acid-induced cellular injury

Acute pancreatitis is a serious and sometimes fatal inflammatory disease where the pancreas digests itself. The non-oxidative ethanol metabolites palmitoleic acid (POA) and POA-ethylester (POAEE) are reported to induce pancreatitis caused by impaired mitochondrial metabolism, cytosolic Ca²⁺ ([Ca²⁺]_i) overload and necrosis of pancreatic acinar cells. Metabolism and [Ca²⁺]_i are linked critically by the ATP-driven plasma membrane Ca²⁺-ATPase (PMCA) important for maintaining low resting [Ca²⁺]_i. The aim of the current study was to test the protective effects of insulin on cellular injury induced by the pancreatitis-inducing agents, ethanol, POA, and POAEE. Rat pancreatic acinar cells were isolated by collagenase digestion and [Ca²⁺]_i was measured by fura-2 imaging. An in situ [Ca²⁺]_i clearance assay was used to assess PMCA activity. Magnesium green (MgGreen) and a luciferase-based ATP kit were used to assess cellular ATP depletion. Ethanol (100 mm) and POAEE (100 μm) induced a small but irreversible Ca²⁺ overload response but had no significant effect on PMCA activity. POA (50–100 μm) induced a robust Ca²⁺ overload, ATP depletion, inhibited PMCA activity, and consequently induced necrosis. Insulin pretreatment (100 nm for 30 min) prevented the POA-induced Ca²⁺ overload, ATP depletion, inhibition of the PMCA, and necrosis. Moreover, the insulin-mediated protection of the POA-induced Ca²⁺ overload was partially prevented by the phosphoinositide-3-kinase (PI3K) inhibitor, LY294002. These data provide the first evidence that insulin directly protects pancreatic acinar cell injury induced by bona fide pancreatitis-inducing agents, such as POA. This may have important therapeutic implications for the treatment of pancreatitis.

Artefactual nanoparticle activation of the inflammasome platform: in vitro evidence with a nano-formed calcium phosphate

AIM

To determine whether in vitro experimental conditions dictate cellular activation of the inflammasome by apatitic calcium phosphate nanoparticles.

MATERIAL & METHODS

The responses of blood-derived primary human cells to in situ-formed apatite were investigated under different experimental conditions to assess the effect of aseptic culture, cell rest and duration of particle exposure. Cell death and particle uptake were assessed, while IL-1β and caspase 1 responses, with and without lipopolysaccharide prestimulation, were evaluated as markers of inflammasome activation.

RESULTS

Under carefully addressed experimental conditions, apatitic nanoparticles did not induce cell death or engage the inflammasome platform, although both could be triggered through artefacts of experimentation.

CONCLUSION

In vitro studies often predict that engineered nanoparticles, such as synthetic apatite, are candidates for inflammasome activation and, hence, are toxic. However, the experimental setting must be very carefully considered as it may promote false-positive outcomes.

Analysis of the lipidome of xenografts using MALDI-IMS and UHPLC-ESI-QTOF

Human tumor xenografts in immunodeficient mice are a very popular model to study the development of cancer and to test new drug candidates. Among the parameters analyzed are the variations in the lipid composition, as they are good indicators of changes in the cellular metabolism. Here, we present a study on the distribution of lipids in xenografts of NCI-H1975 human lung cancer cells, using MALDI imaging mass spectrometry and UHPLC-ESI-QTOF. The identification of lipids directly from the tissue by MALDI was aided by the comparison with identification using ESI ionization in lipid extracts from the same xenografts. Lipids belonging to PCs, PIs, SMs, DAG, TAG, PS, PA, and PG classes were identified and their distribution over the xenograft was determined. Three areas were identified in the xenograft, corresponding to cells in different metabolic stages and to a layer of adipose tissue that covers the xenograft.

Amphiphilic degradable polymers for immobilization and sustained delivery of sphingosine 1-phosphate

Controlled delivery of the angiogenic factor sphingosine 1-phosphate (S1P) represents a promising strategy for promoting vascularization during tissue repair and regeneration. In this study, we developed an amphiphilic biodegradable polymer platform for the stable encapsulation and sustained release of S1P. Mimicking the interaction between amphiphilic S1P and its binding proteins, a series of polymers with hydrophilic poly(ethylene glycol) core and lipophilic flanking segments of polylactide and/or poly(alkylated lactide) with different alkyl chain lengths were synthesized. These polymers were electrospun into fibrous meshes, and loaded with S1P in generally high loading efficiencies (>90%). Sustained S1P release from these scaffolds could be tuned by adjusting the alkyl chain length, blockiness and lipophilic block length, achieving 35-55% and 45-80% accumulative releases in the first 8h and by 7 days, respectively. Furthermore, using endothelial cell tube formation assay and chicken chorioallantoic membrane assay, we showed that the different S1P loading doses and release kinetics translated into distinct pro-angiogenic outcomes. These results suggest that these amphiphilic polymers are effective delivery vehicles for S1P and may be explored as tissue engineering scaffolds where the delivery of lipophilic or amphiphilic bioactive factors is desired.

Interference in immunoassays to support therapeutic antibody development in preclinical and clinical studies

During preclinical and clinical studies, immunoassays are used to measure the concentration of the therapeutic antibody, anti-drug antibodies and soluble protein biomarkers. The reliability of these assays is crucial since the results are routinely used for safety assessment and dose selection. Furthermore, soluble protein biomarkers can provide information about target engagement, proof of mechanism, proof of principle and prediction of response. Study samples mostly consist of complex matrices that can exhibit considerable interference, resulting in inaccurate measurements. This perspective discusses the source of interference and strategies to mitigate or eliminate interference in immunoassays used during preclinical and clinical drug development of drugs with a focus on the development of therapeutic antibodies.

The fat cell senescence hypothesis: a mechanism responsible for abrogating the resolution of inflammation in chronic disease

PURPOSE OF REVIEW

Obesity is a chronic inflammatory disease in which the physiological resolution of inflammation is attenuated, leading to low-grade inflammation throughout the body. However, the heat shock response, which is a key component of the physiological response to resolve inflammation, is seriously hampered in adipose tissue and other metabolic organs (e.g. skeletal muscle, liver, pancreatic β-cells) in metabolic diseases. In this review, we hypothesize that adipocyte metabolic stress triggers the onset of fat cell senescence, and companion senescence-associated secretory phenotype (SASP), and that such a scenario is responsible for attenuating the resolution of inflammation.

RECENT FINDINGS

We shall discuss the role of the heat shock response in the context of the resolution of inflammation and the relevance of heat shock response blockade in chronic inflammatory diseases. Sirtuin-1 is responsible for the induction of heat shock transcription factor-1 mRNA expression and for the stabilization of heat shock transcription factor-1 in a high-profile activity state. However, adipose tissue-emanated SASP depress sirtuin-1 expression, leading adipocytes to a perpetual state of unresolved inflammation, due to a dampening of the heat shock response.

SUMMARY

The advance of inflammasome-mediated SASP from adipose to other tissues promotes cellular senescence in many other cells of the organism, aggravating obesity-dependent chronic inflammation. Inducers of heat shock response (e.g. heat shock itself, physical exercise and calorie restriction) may efficiently interrupt this vicious cycle and are envisaged as the best and also the most economical treatment for obesity-related chronic diseases.

Epigenetics and pancreatic cancer: pathophysiology and novel treatment aspects

An improvement in pancreatic cancer treatment represents an urgent medical goal. Late diagnosis and high intrinsic resistance to conventional chemotherapy has led to a dismal overall prognosis that has remained unchanged during the past decades. Increasing knowledge about the molecular pathogenesis of the disease has shown that genetic alterations, such as mutations of K-ras, and especially epigenetic dysregulation of tumor-associated genes, such as silencing of the tumor suppressor p16(ink4a), are hallmarks of pancreatic cancer. Here, we describe genes that are commonly affected by epigenetic dysregulation in pancreatic cancer via DNA methylation, histone acetylation or miRNA (microRNA) expression, and review the implications on pancreatic cancer biology such as epithelial-mesenchymal transition, morphological pattern formation, or cancer stem cell regulation during carcinogenesis from PanIN (pancreatic intraepithelial lesions) to invasive cancer and resistance development. Epigenetic drugs, such as DNA methyltransferases or histone deactylase inhibitors, have shown promising preclinical results in pancreatic cancer and are currently in early phases of clinical development. Combinations of epigenetic drugs with established cytotoxic drugs or targeted therapies are promising approaches to improve the poor response and survival rate of pancreatic cancer patients.

Identifcation of differentially expressed long non-coding RNAs in CD4+ T cells response to latent tuberculosis infection

Objective

To identify differentially expressed long non-coding RNAs (lncRNAs) in CD4⁺ T cells triggered upon latent tuberculosis (TB) infection.

Methods

Expression profiles of lncRNAs and mRNAs in CD4⁺ T cells from individuals with latent TB infection (LTBI), active TB and healthy controls were analyzed by microarray assay and four lncRNAs were selected for validation using real time-quantitative polymerase chain reaction (RT-qPCR). Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway based approaches were used to investigate biological functions and signaling pathways affected by the differentially expressed mRNAs.

Results

LncRNAs and mRNAs in CD4⁺ T cells were involved in LTBI and active TB disease. Compared with healthy controls, 449 lncRNAs and 461 mRNAs were deregulated in LTBI group, 1,113 lncRNAs and 1,490 mRNAs were deregulated in active TB group, as well as 163 lncRNAs and 187 mRNAs were differentially expressed in both LTBI and active TB group. It was worth noting that 41 lncRNAs and 60 mRNAs were deregulated between three groups. Most deregulated lncRNAs were from intergenic regions (∼50%), natural antisense to protein-coding loci (∼20%), or intronic antisense to protein-coding loci (∼10%). Significantly enriched signaling pathways based on deregulated mRNAs were mainly involved in mitogen-activated protein kinase (MAPK) signaling pathway, cytokine–cytokine receptor interaction, Toll-like receptor signaling pathway, etc.

Conclusions

The study was the first report of differentially expressed lncRNAs in CD4⁺ T cells response to TB infection and indicated that some lncRNAs may be involved in regulating host immune response to TB infection. Future studies are needed to further elucidate potential roles of these deregulated lncRNAs in LTBI and its reactivation.

Role of lysosomes in silica-induced inflammasome activation and inflammation in absence of MARCO

MARCO is the predominant scavenger receptor for recognition and binding of silica particles by alveolar macrophages (AM). Previously, it was shown that mice null for MARCO have a greater inflammatory response to silica, but the mechanism was not described. The aim of this study was to determine the relationship between MARCO and NLRP3 inflammasome activity. Silica increased NLRP3 inflammasome activation and release of the proinflammatory cytokine, IL-1β, to a greater extent in MARCO^−/− AM compared to wild type (WT) AM. Furthermore, in MARCO^−/− AM there was greater cathepsin B release from phagolysosomes, Caspase-1 activation, and acid sphingomyelinase activity compared to WT AM, supporting the critical role played by lysosomal membrane permeabilization (LMP) in triggering silica-induced inflammation. The difference in sensitivity to LMP appears to be in cholesterol recycling since increasing cholesterol in AM by treatment with U18666A decreased silica-induced NLRP3 inflammasome activation, and cells lacking MARCO were less able to sequester cholesterol following silica treatment. Taken together, these results demonstrate that MARCO contributes to normal cholesterol uptake in macrophages; therefore, in the absence of MARCO, macrophages are more susceptible to a greater inflammatory response by particulates known to cause NLRP3 inflammasome activation and the effect is due to increased LMP.

Complementary effects of ciclopirox olamine, a prolyl hydroxylase inhibitor and sphingosine 1-phosphate on fibroblasts and endothelial cells in driving capillary sprouting

Capillary sprouting, a key step of neoangiogenesis in wound healing and tumor growth, also represents a therapeutic target for tissue repair. It requires crosstalk between endothelial cells (EC) and other cell types. We studied this process in a microfluidic platform that allows EC to migrate out of a channel across a collagen gel up a gradient of factors produced by a collection of encapsulated fibroblasts. Introduction of a prolyl hydroxylase inhibitor (PHi), ciclopirox olamine (CPX) to stabilize hypoxia inducible factor 1α (HIF-1α) predominantly in fibroblasts induced capillary sprouting in EC, but the most complex tubular networks with true lumina formed after combining CPX with the lysophospholipid sphingosine 1-phosphate (S1P). The enhanced angiogenesis is a possible consequence of the generation of mutually stimulating factors as each cell type responded differently to the compounds. The combination of CPX and S1P induced secretion of vascular endothelial growth factor (VEGF) in fibroblast culture whereas the angiogenic monocyte chemoattractant protein (MCP)-1 was exclusively secreted by fibroblasts, but only in the presence of EC-conditioned medium. Antibody interference with fibroblast-produced VEGF and MCP-1 inhibited the sprouting response. These observations not only demonstrate the collaboration of EC and fibroblasts in inducing capillary sprouting but also suggest that the combination of CPX and S1P enhances angiogenesis and thus might be of therapeutic value for the pharmacological induction of tissue repair and regeneration.

The adaptor CRADD/RAIDD controls activation of endothelial cells by proinflammatory stimuli

A hallmark of inflammation, increased vascular permeability, is induced in endothelial cells by multiple agonists through stimulus-coupled assembly of the CARMA3 signalosome, which contains the adaptor protein BCL10. Previously, we reported that BCL10 in immune cells is targeted by the "death" adaptor CRADD/RAIDD (CRADD), which negatively regulates nuclear factor κB (NFκB)-dependent cytokine and chemokine expression in T cells (Lin, Q., Liu, Y., Moore, D. J., Elizer, S. K., Veach, R. A., Hawiger, J., and Ruley, H. E. (2012) J. Immunol. 188, 2493-2497). This novel anti-inflammatory CRADD-BCL10 axis prompted us to analyze CRADD expression and its potential anti-inflammatory action in non-immune cells. We focused our study on microvascular endothelial cells because they play a key role in inflammation. We found that CRADD-deficient murine endothelial cells display heightened BCL10-mediated expression of the pleotropic proinflammatory cytokine IL-6 and chemokine monocyte chemoattractant protein-1 (MCP-1/CCL2) in response to LPS and thrombin. Moreover, these agonists also induce significantly increased permeability in cradd(-/-), as compared with cradd(+/+), primary murine endothelial cells. CRADD-deficient cells displayed more F-actin polymerization with concomitant disruption of adherens junctions. In turn, increasing intracellular CRADD by delivery of a novel recombinant cell-penetrating CRADD protein (CP-CRADD) restored endothelial barrier function and suppressed the induction of IL-6 and MCP-1 evoked by LPS and thrombin. Likewise, CP-CRADD enhanced barrier function in CRADD-sufficient endothelial cells. These results indicate that depletion of endogenous CRADD compromises endothelial barrier function in response to inflammatory signals. Thus, we define a novel function for CRADD in endothelial cells as an inducible suppressor of BCL10, a key mediator of responses to proinflammatory agonists.

IIS--Integrated Interactome System: a web-based platform for the annotation, analysis and visualization of protein-metabolite-gene-drug interactions by integrating a variety of data sources and tools

BACKGROUND

High-throughput screening of physical, genetic and chemical-genetic interactions brings important perspectives in the Systems Biology field, as the analysis of these interactions provides new insights into protein/gene function, cellular metabolic variations and the validation of therapeutic targets and drug design. However, such analysis depends on a pipeline connecting different tools that can automatically integrate data from diverse sources and result in a more comprehensive dataset that can be properly interpreted.

RESULTS

We describe here the Integrated Interactome System (IIS), an integrative platform with a web-based interface for the annotation, analysis and visualization of the interaction profiles of proteins/genes, metabolites and drugs of interest. IIS works in four connected modules: (i) Submission module, which receives raw data derived from Sanger sequencing (e.g. two-hybrid system); (ii) Search module, which enables the user to search for the processed reads to be assembled into contigs/singlets, or for lists of proteins/genes, metabolites and drugs of interest, and add them to the project; (iii) Annotation module, which assigns annotations from several databases for the contigs/singlets or lists of proteins/genes, generating tables with automatic annotation that can be manually curated; and (iv) Interactome module, which maps the contigs/singlets or the uploaded lists to entries in our integrated database, building networks that gather novel identified interactions, protein and metabolite expression/concentration levels, subcellular localization and computed topological metrics, GO biological processes and KEGG pathways enrichment. This module generates a XGMML file that can be imported into Cytoscape or be visualized directly on the web.

CONCLUSIONS

We have developed IIS by the integration of diverse databases following the need of appropriate tools for a systematic analysis of physical, genetic and chemical-genetic interactions. IIS was validated with yeast two-hybrid, proteomics and metabolomics datasets, but it is also extendable to other datasets. IIS is freely available online at: http://www.lge.ibi.unicamp.br/lnbio/IIS/.

Monoacylglycerol lipase promotes metastases in nasopharyngeal carcinoma

Monoacylglycerol lipase (MAGL) is a serine hydrolase that hydrolyzes monoacylglycerides into free fatty acids and glycerol. It has recently been found to be involved in cancer progression through the free fatty acid or endocannabinoid network after studies on its function in the endocannabinoid system. Here, we determined a role for MAGL in nasopharyngeal carcinoma (NPC), which is known for its high metastatic potential. Among the different NPC cells we tested, MAGL was highly expressed in high metastatic NPC cells, whereas low metastatic potential NPC cells exhibited lower expression of MAGL. Overexpression of MAGL in low metastatic NPC cells enhanced their motile behavior and metastatic capacity in vivo. Conversely, knockdown of MAGL reduced the motility of highly metastatic cells, reducing their metastatic capacity in vivo. Growth rate was not influenced by MAGL in either high or low metastatic cells. MAGL expression was associated with the epithelial-mesenchymal transition (EMT) proteins, such as E-cadherin, vimentin and Snail. It was also related to the sidepopulation (SP) of NPC cells. Our findings establish that MAGL promotes metastases in NPC through EMT, and it may serve as a target for the prevention of NPC metastases.

NFAT1 and NFAT3 cooperate with HDAC4 during regulation of alternative splicing of PMCA isoforms in PC12 cells

Background

The bulk of human genes undergo alternative splicing (AS) upon response to physiological stimuli. AS is a great source of protein diversity and biological processes and is associated with the development of many diseases. Pheochromocytoma is a neuroendocrine tumor, characterized by an excessive Ca²⁺-dependent secretion of catecholamines. This underlines the importance of balanced control of calcium transport via regulation of gene expression pattern, including different calcium transport systems, such as plasma membrane Ca²⁺-ATPases (PMCAs), abundantly expressed in pheochromocytoma chromaffin cells (PC12 cells). PMCAs are encoded by four genes (Atp2b1, Atp2b2, Atp2b3, Atp2b4), whose transcript products undergo alternative splicing giving almost 30 variants.

Results

In this scientific report, we propose a novel mechanism of regulation of PMCA alternative splicing in PC12 cells through cooperation of the nuclear factor of activated T-cells (NFAT) and histone deacetylases (HDACs). Luciferase assays showed increased activity of NFAT in PC12 cells, which was associated with altered expression of PMCA. RT-PCR experiments suggested that inhibition of the transcriptional activity of NFAT might result in the rearrangement of PMCA splicing variants in PC12 cells. NFAT inhibition led to dominant expression of 2x/c, 3x/a and 4x/a PMCA variants, while in untreated cells the 2w,z/b, 3z,x/b,c,e,f, and 4x/b variants were found as well. Furthermore, chromatin immunoprecipitation experiments showed that NFAT1-HDAC4 or NFAT3-HDAC4 complexes might be involved in regulation of PMCA2x splicing variant generation.

Conclusions

We suggest that the influence of NFAT/HDAC on PMCA isoform composition might be important for altered dopamine secretion by PC12 cells.

Assessment of the metabolism of therapeutic proteins and antibodies

INTRODUCTION

In the last decade, our increased knowledge of factors governing the pharmacokinetics and metabolism of biologics (recombinant therapeutic proteins) has driven, and will continue to support, biological engineering and the design of delivery systems for more efficient biologics. Further research in analytical methods for assessing their in vitro and/or in vivo metabolism will also support these developments.

AREAS COVERED

In this review we will discuss the main components affecting the metabolism of biologics, and try to demonstrate how novel analytical evaluations will facilitate their future development. We will focus on the use of radiolabeled drugs, ligand-binding assays and mass spectrometry.

EXPERT OPINION

Future marketed biologics will be complex structures, such as glycoengineered, fused, or chemically modified proteins. Their in vivo efficiencies will be strongly dependent on their metabolic stabilities. Similarly to small molecular drugs, for which in vitro and in vivo biochemical platforms and analytical techniques have helped to rationalize preclinical and clinical developments, we would expect this also to translate to effective approaches to study the metabolism of biologics in the near future. Mass spectrometry should emerge as a standard technique for in vivo characterization of the biotransformation products of biologics.

Drug-Like Protein-Protein Interaction Modulators: Challenges and Opportunities for Drug Discovery and Chemical Biology

[Formula: see text] Fundamental processes in living cells are largely controlled by macromolecular interactions and among them, protein-protein interactions (PPIs) have a critical role while their dysregulations can contribute to the pathogenesis of numerous diseases. Although PPIs were considered as attractive pharmaceutical targets already some years ago, they have been thus far largely unexploited for therapeutic interventions with low molecular weight compounds. Several limiting factors, from technological hurdles to conceptual barriers, are known, which, taken together, explain why research in this area has been relatively slow. However, this last decade, the scientific community has challenged the dogma and became more enthusiastic about the modulation of PPIs with small drug-like molecules. In fact, several success stories were reported both, at the preclinical and clinical stages. In this review article, written for the 2014 International Summer School in Chemoinformatics (Strasbourg, France), we discuss in silico tools (essentially post 2012) and databases that can assist the design of low molecular weight PPI modulators (these tools can be found at www.vls3d.com). We first introduce the field of protein-protein interaction research, discuss key challenges and comment recently reported in silico packages, protocols and databases dedicated to PPIs. Then, we illustrate how in silico methods can be used and combined with experimental work to identify PPI modulators.

Atheroprotective role of high-density lipoprotein (HDL)-associated sphingosine-1-phosphate (S1P)

Numerous epidemiological studies documented an inverse relationship between plasma high-density lipoprotein (HDL) cholesterol levels and the extent of atherosclerotic disease. However, clinical interventions targeting HDL cholesterol failed to show clinical benefits with respect to cardiovascular risk reduction, suggesting that HDL components distinct from cholesterol may account for anti-atherogenic effects attributed to this lipoprotein. Sphingosine-1-phosphate (S1P)-a lysosphingolipid exerting its biological activity via binding to specific G protein-coupled receptors and regulating a wide array of biological responses in a variety of different organs and tissues including the cardiovascular system-has been identified as an integral constituent of HDL particles. In the present review, we discuss current evidence from epidemiological studies, experimental approaches in vitro, and animal models of atherosclerosis, suggesting that S1P contributes to atheroprotective effects exerted by HDL particles.

Altered antigenic profiling and infectivity of Porphyromonas gingivalis in smokers and non-smokers with periodontitis

BACKGROUND

Cigarette smokers are more susceptible to periodontal diseases and are more likely to be infected with Porphyromonas gingivalis than non-smokers. Furthermore, smoking is known to alter the expression of P. gingivalis surface components and compromise immunoglobulin (Ig)G generation. The aim of this study is to evaluate whether the overall IgG response to P. gingivalis is suppressed in smokers in vivo and whether previously established in vitro tobacco-induced phenotypic P. gingivalis changes would be reflected in vivo.

METHODS

The authors examined the humoral response to several P. gingivalis strains as well as specific tobacco-regulated outer membrane proteins (FimA and RagB) by enzyme-linked immunosorbent assay in biochemically validated (salivary cotinine) smokers and non-smokers with chronic periodontitis (CP: n = 13) or aggressive periodontitis (AgP: n = 20). The local and systemic presence of P. gingivalis DNA was also monitored by polymerase chain reaction.

RESULTS

Smoking was associated with decreased total IgG responses against clinical (10512, 5607, and 10208C; all P <0.05) but not laboratory (ATCC 33277, W83) P. gingivalis strains. Smoking did not influence IgG produced against specific cell-surface proteins, although a non-significant pattern toward increased total FimA-specific IgG in patients with CP, but not AgP, was observed. Seropositive smokers were more likely to be infected orally and systemically with P. gingivalis (P <0.001), as determined by 16S RNA analysis.

CONCLUSION

Smoking alters the humoral response against P. gingivalis and may increase P. gingivalis infectivity, strengthening the evidence that mechanisms of periodontal disease progression in smokers may differ from those of non-smokers with the same disease classification.

One-step synthesis of platinum nanoparticles loaded in alginate bubbles

Composite particles with multifunctions have been extensively utilized for various applications. Bubble particles can be applied for ultrasound-mediated imaging, drug delivery, absorbers, cell culture, etc. This study proposes a one-step strategy to obtain Pt nanoparticles loaded in alginate bubbles. A needle-based droplet formation was used to generate uniform alginate particles about 2 mm in diameter. The hydrolysis reaction of NaBH4 was utilized to produce gaseous hydrogen and then trapped within alginate particles to form bubbles. The Pt(4+) mixed with alginate solution was dropped into the reservoir to react with reducing NaBH4 and hardening CaCl2 to form Pt nanoparticles-alginate composite bubbles. Results indicate that the size of bubbles decreases with the CaCl2 concentration (1% ~ 20%), and size of bubbles increases with the NaBH4 concentration (1 ~ 20 mM). The advantages for the present approach include low cost, easy operation, and effective production of Pt nanoparticles-alginate composite bubbles.

Prostate cancer relevant antigens and enzymes for targeted drug delivery

Chemotherapy is one of the most widely used approaches in combating advanced prostate cancer, but its therapeutic efficacy is usually insufficient due to poor specificity and associated toxicity. Lack of targeted delivery to prostate cancer cells is also the primary obstacles in achieving feasible therapeutic effect of other promising agents including peptide, protein, and nucleic acid. Consequently, there remains a critical need for strategies to increase the selectivity of anti-prostate cancer agents. This review will focus on various prostate cancer-relevant antigens and enzymes that could be exploited for prostate cancer targeted drug delivery. Among various targeting strategies, active targeting is the most advanced approach to specifically deliver drugs to their designated cancer cells. In this approach, drug carriers are modified with targeting ligands that can specifically bind to prostate cancer-specific antigens. Moreover, there are several specific enzymes in the tumor microenvironment of prostate cancer that can be exploited for stimulus-responsive drug delivery systems. These systems can specifically release the active drug in the tumor microenvironment of prostate cancer, leading to enhanced tumor penetration efficiency.

Lipopolysaccharide-induced microRNA-146a targets CARD10 and regulates angiogenesis in human umbilical vein endothelial cells

This aim of this study was to explore the role of miRNA-146a (miR-146a) and its target genes in endothelial cells. We demonstrated that lipopolysaccharide (LPS) induced the upregulation of miR-146a in human umbilical vein endothelial cells (HUVECs), and that the induction was blocked by silencing toll-like receptors, the adaptor molecule MyD88, and the nonspecific NF-κB inhibitor BAY 11-7082. In addition, knockdown of miR-146a by transfection of the locked nucleic acid antimiR-146a significantly inhibited LPS-induced cell migration and tube formation. A combined analysis of bioinformatics miRanda algorithms and a whole genome expression microarray of immunoprecipitated Ago2 ribonucleoprotein complexes identified 14 potential target genes. Subsequent transfection with the miR-146a precursor pre-miR-146a into HUVECs validated that CARD10 was the target gene of the miR-146a, both at the mRNA and protein levels. Silencing CARD10 inhibited p65 nuclear translocation in the cells receiving LPS stimulation and increased angiogenesis. Therefore, miR-146a may play a role in regulating the angiogenesis in HUVECs by downregulating CARD10, which acts in a negative feedback regulation loop to inhibit the activation of NF-κB that normally impairs angiogenesis.

Promoter hypermethylation influences the suppressive role of maternally expressed 3, a long non-coding RNA, in the development of epithelial ovarian cancer

Maternally expressed 3 (MEG3) is a long non-coding RNA that can activate p53 and inhibit tumorigenesis and progression of various types of cancers. However, the role of MEG3 in epithelial ovarian cancer (EOC) is still unknown. The aim of the present study was to confirm whether MEG3 is downregulated in human EOC, determine its possible mechanism of action and elucidate the role of MEG3 in EOC. Differences in the expression of MEG3 and in the methylation status of the MEG3 promoter between EOC and normal ovary were analyzed using RT-PCR and methylation-specific PCR (MSP), respectively. MTT and EdU assays and flow cytometric analysis were used to assess the growth of ovarian cancer cells after overexpression of MEG3. The target genes regulated by MEG3 were detected with the Dual Luciferase Reporter system. The expression levels of target genes were confirmed using RT-PCR and western blotting. In contrast to normal ovarian tissues, the expression of MEG3 was absent or decreased in most EOC tissues as well as in human EOC cell lines, and the promoter of the MEG3 gene was highly methylated in both cancer tissues and cell lines. Treatment with 5-aza-2-deoxycytidine reversed the promoter hypermethylation and increased MEG3 expression. In addition, ectopic expression of MEG3 suppressed the proliferation and growth of OVCAR3 cells and promoted apoptosis. Finally, MEG3 activated p53 in OVCAR3 cells. In conclusion, our data suggest that MEG3 is epigenetically silenced in EOC due to promoter hypermethylation, which may contribute to the development of EOC.

Glycoursodeoxycholic acid reduces matrix metalloproteinase-9 and caspase-9 activation in a cellular model of superoxide dismutase-1 neurodegeneration

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease that affects mainly motor neurons (MNs). NSC-34 MN-like cells carrying the G93A mutation in human superoxide dismutase-1 (hSOD1(G93A)) are a common model to study the molecular mechanisms of neurodegeneration in ALS. Although the underlying pathways of MN failure still remain elusive, increased apoptosis and oxidative stress seem to be implicated. Riluzole, the only approved drug, only slightly delays ALS progression. Ursodeoxycholic acid (UDCA), as well as its glycine (glycoursodeoxycholic acid, GUDCA) and taurine (TUDCA) conjugated species, have shown therapeutic efficacy in neurodegenerative models and diseases. Pilot studies in ALS patients indicate safety and tolerability for UDCA oral administration. We explored the mechanisms associated with superoxide dismutase-1 (SOD1) accumulation and MN degeneration in NSC-34/hSOD1(G93A) cells differentiated for 4 days in vitro (DIV). We examined GUDCA efficacy in preventing such pathological events and in restoring MN functionality by incubating cells with 50 μM GUDCA at 0 DIV and at 2 DIV, respectively. Increased cytosolic SOD1 inclusions were observed in 4 DIV NSC-34/hSOD1(G93A) cells together with decreased mitochondria viability (1.2-fold, p < 0.01), caspase-9 activation (1.8-fold, p < 0.05), and apoptosis (2.1-fold, p < 0.01). GUDCA exerted preventive effects (p < 0.05) while also reduced caspase-9 levels when added at 2 DIV (p < 0.05). ATP depletion (2-fold, p < 0.05), increased nitrites (1.6-fold, p < 0.05) and metalloproteinase-9 (MMP-9) activation (1.8-fold, p < 0.05), but no changes in MMP-2, were observed in the extracellular media of 4 DIV NSC-34/hSOD1(G93A) cells. GUDCA inhibited nitrite production (p < 0.05) while simultaneously prevented and reverted MMP-9 activation (p < 0.05), but not ATP depletion. Data highlight caspase-9 and MMP-9 activation as key pathomechanisms in ALS and GUDCA as a promising therapeutic strategy for slowing disease onset and progression.

S100β as an early biomarker of excitotoxic damage in spinal cord organotypic cultures

S100β is a cytoplasmic calcium-binding protein mainly expressed by glia and considered to be a useful biomarker for brain or spinal cord injury. Indeed, clinical studies suggest that the S100β concentration in serum or cerebrospinal fluid may predict lesion outcome and prognosis. The relation of S100β levels to damage severity and its timecourse remains, however, unclear. This study used a validated in vitro model of spinal cord injury induced by kainate-mediated excitotoxicity to investigate these issues. After 22 days in vitro, rat organotypic spinal cord slices were subjected to one transient application (1 h) of 1 or 100 μM kainate followed by washout. While the lower kainate concentration did not evoke neuronal loss or S100β increase, the larger concentration elicited 40% neuronal death, no change in glial number and a delayed, significant rise in extracellular S100β that peaked at 24 h. This increase was associated with a stronger expression of the S100β protein as indicated by western blotting and immunohistochemistry. Application of the microtubule disrupting agent colchicine did not change the rise in S100β induced by kainate, an effect blocked by the glutamate receptor antagonists CNQX and APV. Our data suggest that excitotoxicity was followed by release of S100β perhaps from a readily releasable pool through a mechanism independent of microtubule assembly. The raised extracellular level of S100β appeared to reflect glial reactivity to the kainate-evoked lesion in accordance with the view that this protein may be involved in tissue protection and repair after acute injury. Excitotoxicity is a major mechanism responsible for neuronal death following acute spinal cord injury. The calcium-binding protein S100β is released by astrocytes into the extracellular compartment during the first 24 h after the initial insult and represents a useful biomarker of lesion progression as its level is related to the occurrence and severity of neuronal loss.

Genetic and metabolomic dissection of the ergothioneine and selenoneine biosynthetic pathway in the fission yeast, S. pombe, and construction of an overproduction system

Ergothioneine is a small, sulfur-containing metabolite (229 Da) synthesized by various species of bacteria and fungi, which can accumulate to millimolar levels in tissues or cells (e.g. erythrocytes) of higher eukaryotes. It is commonly marketed as a dietary supplement due to its proposed protective and antioxidative functions. In this study we report the genes forming the two-step ergothioneine biosynthetic pathway in the fission yeast, Schizosaccharomyces pombe. We identified the first gene, egt1⁺ (SPBC1604.01), by sequence homology to previously published genes from Neurospora crassa and Mycobacterium smegmatis. We showed, using metabolomic analysis, that the Δegt1 deletion mutant completely lacked ergothioneine and its precursors (trimethyl histidine/hercynine and hercynylcysteine sulfoxide). Since the second step of ergothioneine biosynthesis has not been characterized in eukaryotes, we examined four putative homologs (Nfs1/SPBC21D10.11c, SPAC11D3.10, SPCC777.03c, and SPBC660.12c) of the corresponding mycobacterial enzyme EgtE. Among deletion mutants of these genes, only one (ΔSPBC660.12c, designated Δegt2) showed a substantial decrease in ergothioneine, accompanied by accumulation of its immediate precursor, hercynylcysteine sulfoxide. Ergothioneine-deficient strains exhibited no phenotypic defects during vegetative growth or quiescence. To effectively study the role of ergothioneine, we constructed an egt1⁺ overexpression system by replacing its native promoter with the nmt1⁺ promoter, which is inducible in the absence of thiamine. We employed three versions of the nmt1 promoter with increasing strength of expression and confirmed corresponding accumulations of ergothioneine. We quantified the intracellular concentration of ergothioneine in S. pombe (0.3, 157.4, 41.6, and up to 1606.3 µM in vegetative, nitrogen-starved, glucose-starved, and egt1⁺-overexpressing cells, respectively) and described its gradual accumulation under long-term quiescence. Finally, we demonstrated that the ergothioneine pathway can also synthesize selenoneine, a selenium-containing derivative of ergothioneine, when the culture medium is supplemented with selenium. We further found that selenoneine biosynthesis involves a novel intermediate compound, hercynylselenocysteine.

Vasoactive intestinal peptide maintains the nonpathogenic profile of human th17-polarized cells

The cytokine microenvironment modulates CD4 T cell differentiation causing the shift of naïve CD4 T cells into different cell subsets. This process is also regulated by modulators such as vasoactive intestinal peptide (VIP), a neuropeptide with known immunomodulatory properties on CD4 T cells that exert this action through specific receptors, vasoactive intestinal peptide receptor (VPAC)1 and VPAC2. Our results show that the pattern of VIP receptors expression ratio is modified during Th17 differentiation. In this report, we evaluate the capacity of VIP to modulate naïve human cells into Th17 cells in vitro by analyzing their functional phenotype. The presence of VIP maintains the nonpathogenic profile of Th17-polarized cells, increases the proliferation rate, and decreases their Th1 potential. VIP induces the upregulation of the STAT3 gene interaction with the VPAC1 receptor during the onset of Th17 differentiation. Moreover, RAR-related orphan receptor C (RORC), RAR-related orphan receptor A (RORA), and interleukin (IL)-17A genes are upregulated in the presence of VIP through interaction with VPAC1 and VPAC2 receptors. Interestingly, VIP induces the expression of the IL-23R gene through interaction with the VPAC2 receptor during the expansion phase. This is the first report that describes the differentiation of naïve human T cells to Th17-polarized cells in the presence of VIP and demonstrates how this differentiation regulates the expression of the VIP receptors.

DLG5 in cell polarity maintenance and cancer development

Failure in establishment and maintenance of epithelial cell polarity contributes to tumorigenesis. Loss of expression and function of cell polarity proteins is directly related to epithelial cell polarity maintenance. The polarity protein discs large homolog 5 (DLG5) belongs to a family of molecular scaffolding proteins called Membrane Associated Guanylate Kinases (MAGUKs). As the other family members, DLG5 contains the multi-PDZ, SH3 and GUK domains. DLG5 has evolved in the same manner as DLG1 and ZO1, two well-studied MAGUKs proteins. Just like DLG1 and ZO1, DLG5 plays a role in cell migration, cell adhesion, precursor cell division, cell proliferation, epithelial cell polarity maintenance, and transmission of extracellular signals to the membrane and cytoskeleton. Since the roles of DLG5 in inflammatory bowel disease (IBD) and Crohn's disease (CD) have been reviewed, here, our review focuses on the roles of DLG5 in epithelial cell polarity maintenance and cancer development.

Extra virgin olive oil intake delays the development of amyotrophic lateral sclerosis associated with reduced reticulum stress and autophagy in muscle of SOD1G93A mice

Amyotrophic lateral sclerosis is a neurodegenerative disease associated with mutations in antioxidant enzyme Cu/Zn-superoxide dismutase 1. Albeit there is no treatment for this disease, new insights related to an exacerbated lipid metabolism have been reported. In connection with the hypermetabolic lipid status, the hypothesis whether nature of dietary fat might delay the progression of the disease was tested by using a transgenic mouse that overexpresses the human SOD1G93A variant. For this purpose, SOD1G93A mice were assigned randomly to one of the following three experimental groups: (1) a standard chow diet (control, n=21), (2) a chow diet enriched with 20% (w/w) extra virgin olive oil (EVOO, n=22) and (3) a chow diet containing 20% palm oil (palm, n=20). They received the diets for 8 weeks and the progression of the disease was assessed. On the standard chow diet, average plasma cholesterol levels were lower than those mice receiving the high-fat diets. Mice fed an EVOO diet showed a significant higher survival and better motor performance than control mice. EVOO group mice survived longer and showed better motor performance and larger muscle fiber area than animals receiving palm. Moreover, the EVOO-enriched diet improved the muscle status as shown by expression of myogenic factors (Myod1 and Myog) and autophagy markers (LC3 and Beclin1), as well as diminished endoplasmic reticulum (ER) stress through decreasing Atf6 and Grp78. Our results demonstrate that EVOO may be effective in increasing survival rate, improving motor coordination together with a potential amelioration of ER stress, autophagy and muscle damage.

Proteomic analysis of putative heme-binding proteins in Streptococcus pyogenes

Streptococcus pyogenes is an important human bacterium with high pathogenicity. Heme is a major source of iron that plays a critical role in bacterial survival and virulence. In this study, heme-affinity chromatography, two-dimensional-electrophoresis and mass spectrometry were combined to identify putative heme-binding proteins and heme-regulatory proteins. In total, 68 heme-regulatory proteins and 284 putative heme-binding proteins were identified, among which 37 proteins showed expression alterations in response to heme deficiency. Bioinformatics analysis revealed that several key metabolic pathways had changed in the absence of heme, among which glycolysis was a major pathway impaired under heme-deficient conditions. New potential heme-binding proteins were successfully identified in this study providing novel clues for the study of the heme transport mechanism. Heme-binding proteins may play fundamental roles in many important biological pathways and thus contribute to bacterial pathogenicity.

Proteomic study of differential protein expression in mouse lung tissues after aerosolized ricin poisoning

Ricin is one of the most poisonous natural toxins from plants and is classified as a Class B biological threat pathogen by the Centers for Disease Control and Prevention (CDC) of U.S.A. Ricin exposure can occur through oral or aerosol routes. Ricin poisoning has a rapid onset and a short incubation period. There is no effective treatment for ricin poisoning. In this study, an aerosolized ricin-exposed mouse model was developed and the pathology was investigated. The protein expression profile in the ricin-poisoned mouse lung tissue was analyzed using proteomic techniques to determine the proteins that were closely related to the toxicity of ricin. 2D gel electrophoresis, mass spectrometry and subsequent biological functional analysis revealed that six proteins including Apoa1 apolipoprotein, Ywhaz 14-3-3 protein, Prdx6 Uncharacterized Protein, Selenium-binding protein 1, HMGB1, and DPYL-2, were highly related to ricin poisoning.

Nonclinical Safety Biomarkers of Drug-induced Vascular Injury

Better biomarkers are needed to identify, characterize, and/or monitor drug-induced vascular injury (DIVI) in nonclinical species and patients. The Predictive Safety Testing Consortium (PSTC), a precompetitive collaboration of pharmaceutical companies and the U.S. Food and Drug Administration (FDA), formed the Vascular Injury Working Group (VIWG) to develop and qualify translatable biomarkers of DIVI. The VIWG focused its research on acute DIVI because early detection for clinical and nonclinical safety monitoring is desirable. The VIWG developed a strategy based on the premise that biomarkers of DIVI in rat would be translatable to humans due to the morphologic similarity of vascular injury between species regardless of mechanism. The histomorphologic lexicon for DIVI in rat defines degenerative and adaptive findings of the vascular endothelium and smooth muscles, and characterizes inflammatory components. We describe the mechanisms of these changes and their associations with candidate biomarkers for which advanced analytical method validation was completed. Further development is recommended for circulating microRNAs, endothelial microparticles, and imaging techniques. Recommendations for sample collection and processing, analytical methods, and confirmation of target localization using immunohistochemistry and in situ hybridization are described. The methods described are anticipated to aid in the identification and qualification of translational biomarkers for DIVI.

Dominant-negative function of the C-terminal fragments of NBR1 and SQSTM1 generated during enteroviral infection

Coxsackievirus infection induces an abnormal accumulation of ubiquitin aggregates that are generally believed to be noxious to the cells and have a key role in viral pathogenesis. Selective autophagy mediated by autophagy adaptor proteins, including sequestosome 1 (SQSTM1/p62) and neighbor of BRCA1 gene 1 protein (NBR1), are an important pathway for disposing of misfolded/ubiquitin conjugates. We have recently demonstrated that SQSTM1 is cleaved after coxsackievirus infection, resulting in the disruption of SQSTM1 function in selective autophagy. NBR1 is a functional homolog of SQSTM1. In this study, we propose to test whether NBR1 can compensate for the compromise of SQSTM1 after viral infection. Of interest, we found that NBR1 was also cleaved after coxsackievirus infection. This cleavage took place at two sites mediated by virus-encoded protease 2A(pro) and 3C(pro), respectively. In addition to the loss-of-function, we further investigated whether cleavage of SQSTM1/NBR1 leads to the generation of toxic gain-of-function mutants. We showed that the C-terminal fragments of SQSTM1 and NBR1 exhibited a dominant-negative effect against native SQSTM1/NBR1, probably by competing for LC3 and ubiquitin chain binding. Finally, we demonstrated a positive, mutual regulatory relationship between SQSTM1 and NBR1 during viral infection. We showed that knockdown of SQSTM1 resulted in reduced expression of NBR1, whereas overexpression of SQSTM1 led to increased level of NBR1, and vice versa, further excluding the possible compensation of NBR1 for the loss of SQSTM1. Taken together, the findings in this study suggest a novel mechanism through which coxsackievirus infection induces increased accumulation of ubiquitin conjugates and subsequent viral damage.