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Selenoprotein T is required for pathogenic bacteria avoidance in Caenorhabditis elegans

Thu, 05/18/2017 - 10:18am

Selenoprotein T (SELENOT) is an endoplasmatic reticulum (ER)-associated redoxin that contains the amino acid selenocysteine (Sec, U) within a CXXU motif within a thioredoxin-like fold. Its precise function in multicellular organisms is not completely understood although it has been shown in mammals to be involved in Ca2+ homeostasis, antioxidant and neuroendocrine functions. Here, we use the model organism C. elegans to address SELENOT function in a whole organism throughout its life cycle. C. elegans possess two genes encoding SELENOT protein orthologues (SELT-1.1 and SELT-1.2), which lack Sec and contain the CXXC redox motif instead. Our results show that a Sec-->Cys replacement and a gene duplication were two major evolutionary events that occurred in the nematode lineage. We find that worm SELT-1.1 localizes to the ER and is expressed in different cell types, including the nervous system. In contrast, SELT-1.2 exclusively localizes in the cytoplasm of the AWB neurons. We find that selt-1.1 and selt-1.2 single mutants as well as the double mutant are viable, but the selt-1.1 mutant is compromised under rotenone-induced oxidative stress. We demonstrate that selt-1.1, but not selt-1.2, is required for avoidance to the bacterial pathogens Serratia marcescens and Pseudomonas aeruginosa. Aversion to the noxious signal 2-nonanone is also significantly impaired in selt-1.1, but not in selt-1.2 mutant animals. Our results suggest that selt-1.1 would be a redox transducer required for nociception and optimal organismal fitness. The results highlight C. elegans as a valuable model organism to study SELENOT-dependent processes.

Local neuropeptide signaling modulates serotonergic transmission to shape the temporal organization of C. elegans egg-laying behavior

Thu, 05/18/2017 - 10:18am

Animal behaviors are often composed of distinct alternating behavioral states. Neuromodulatory signals are thought to be critical for establishing stable behavioral states and for orchestrating transitions between them. However, we have only a limited understanding of how neuromodulatory systems act in vivo to alter circuit performance and shape behavior. To address these questions, we have investigated neuromodulatory signaling in the context of Caenorhabditis elegans egg-laying. Egg-laying activity cycles between discrete states-short bursts of egg deposition (active phases) that alternate with prolonged quiescent periods (inactive phases). Here using genetic, pharmacological and optogenetic approaches for cell-specific activation and inhibition, we show that a group of neurosecretory cells (uv1) located in close spatial proximity to the egg-laying neuromusculature direct the temporal organization of egg-laying by prolonging the duration of inactive phases. We demonstrate that the modulatory effects of the uv1 cells are mediated by peptides encoded by the nlp-7 and flp-11 genes that act locally to inhibit circuit activity, primarily by inhibiting vesicular release of serotonin from HSN motor neurons. This peptidergic inhibition is achieved, at least in part, by reducing synaptic vesicle abundance in the HSN motor neurons. By linking the in vivo actions of specific neuropeptide signaling systems with the generation of stable behavioral outcomes, our study reveals how cycles of neuromodulation emanating from non-neuronal cells can fundamentally shape the organization of a behavioral program.

Excitatory neurons sculpt GABAergic neuronal connectivity in the C. elegans motor circuit

Thu, 05/18/2017 - 10:17am

Establishing and maintaining the appropriate number of GABA synapses is key for balancing excitation and inhibition in the nervous system, though we have only a limited understanding of the mechanisms controlling GABA circuit connectivity. Here, we show that disrupting cholinergic innervation of GABAergic neurons in the C. elegans motor circuit alters GABAergic neuron synaptic connectivity. These changes are accompanied by a reduced frequency and increased amplitude of GABAergic synaptic events. Acute genetic disruption in early development-during the integration of post-embryonic born GABAergic neurons into the circuit-produces irreversible effects on GABAergic synaptic connectivity that mimic those produced by chronic manipulations. In contrast, acute genetic disruption of cholinergic signaling in the adult circuit does not reproduce these effects. Our findings reveal that GABAergic signaling is regulated by cholinergic neuronal activity, likely through distinct mechanisms in the developing and mature nervous system.

Statins for Primary Prevention in Older Adults: Uncertainty and the Need for More Evidence

Wed, 05/17/2017 - 8:29am

Introduction: Given the substantially increasing geriatric population, the need for evidence-based strategies to address the medical and societal consequences of these demographic trends has never been greater. In this context, statins for primary prevention of atherosclerotic cardiovascular disease (ASCVD) provide substantial potential social value by improving health and survival. However, using statins for primary prevention in older adults presents a clinical dilemma. Even though compelling evidence exists supporting statins for secondary prevention in individuals older than 75 years with clinical ASCVD, the same cannot be said for primary prevention. In this Viewpoint, we describe existing evidence on the benefits of statins for primary prevention in older adults, uncertainties about risks, and the need for a randomized trial before non–evidence-based prescribing patterns become irreversibly incorporated into practice.

Keeping Weight Off: study protocol of an RCT to investigate brain changes associated with mindfulness-based stress reduction

Wed, 05/17/2017 - 8:28am

INTRODUCTION: Obesity is a growing epidemic fuelled by unhealthy behaviours and associated with significant comorbidities and financial costs. While behavioural interventions produce clinically meaningful weight loss, weight loss maintenance is challenging. This may partially be due to failure to target stress and emotional reactivity. Mindfulness-based stress reduction (MBSR) reduces stress and emotional reactivity and may be a useful tool for behaviour change maintenance. This study seeks to provide a mechanistic understanding for clinical trials of the benefits of MBSR for weight loss maintenance by examining changes in functional connectivity (FC) and the association of these changes with clinical outcomes.

METHODS AND ANALYSIS: Community-dwelling individuals (n=80) who intentionally lost >/=5% of their body weight in the past year will be recruited and randomised to an MBSR programme or educational control. FC using resting-state functional MRI will be measured at baseline and 8 weeks. Psychological factors, health behaviours, body mass index and waist circumference will be measured at baseline, 8 weeks and 6 months post intervention. A 12-month telephone follow-up will assess self-reported weight. Analyses will characterise FC changes in response to MBSR in comparison with a control condition, assess the relationship between baseline FC status and pre-post MBSR changes in FC and investigate the association of FC change with changes in psychological factors and weight loss maintenance.

ETHICS AND DISSEMINATION: The University of Massachusetts Medical School Institutional Review Board has approved this study, Declaration of Helsinki protocols are being followed, and patients will give written informed consent. The Independent Monitoring Committee will monitor protocol adherence. Results from the study will be disseminated to the medical community at conferences and submitted for publication in peer-reviewed journals when the last patient included has been followed up for 12 months.

TRIAL REGISTRATION NUMBER: NCT02189187.

Online tobacco websites and online communities-who uses them and do users quit smoking? The quit-primo and national dental practice-based research network Hi-Quit studies

Wed, 05/17/2017 - 8:28am

Online tobacco cessation communities are beneficial but underused. Our study examined whether, among smokers participating in a web-assisted tobacco intervention (Decide2quit.org), specific characteristics were associated with navigating to BecomeAnEx.org, an online cessation community, and with subsequent quit rates. Among smokers (N = 759) registered with Decide2quit.org, we identified visitors to BecomeAnEx.org, examining associations between smoker characteristics and likelihood of visiting. We then tested for associations between visits and 6-month cessation (point prevalence). We also tested for an interaction between use of other online support-seeking (Decide2quit.org tobacco cessation coaches), visiting, and 6-month cessation. One quarter (26.0 %; n = 197) of the smokers visited BecomeAnEx.org; less than one tenth (7.5 %; n = 57) registered to participate in the online forum. Visitors were more likely to be female (73.0 vs. 62.6 % of non-visitors, P < 0.01) to have visited a cessation website before (33.0 vs. 17.4 %, P < 0.01) and to report quit attempts in the previous year (62.0 vs. 53.0 %, P = 0.03). In analyses of all participants, BecomeAnEx.org visiting was not associated with 6-month quit completion. Among participants who communicated with a coach, BecomeAnEx.org visiting also lacked a significant association with 6 month quit completion, although a non-significant trend toward quit completion in visitors was noted (OR 2.21, 95 % CI 0.81-3.1). Online cessation communities attract smokers with previous cessation website experience and recent quit attempts. Community visiting was not associated with quit rates in our study, but low use may have limited our power to detect differences. Further research should explore whether an additive effect can be achieved by offering community visitors support via online coaches.

Hot Flash Frequency and Blood Pressure: Data from the Study of Women's Health Across the Nation

Wed, 05/17/2017 - 8:28am

BACKGROUND: Vasomotor symptoms (VMS) are highly prevalent among midlife women and have been associated with subclinical cardiovascular disease (CVD). However, the association between VMS frequency and risk factors such as hypertension (HTN) remains unclear.

MATERIALS AND METHODS: We examined VMS frequency and blood pressure (BP) among 2839 participants of the Study of Women's Health Across the Nation (SWAN), a multiethnic, prospective, study of women enrolled from seven U.S. sites between November 1995 and October 1997. Women were age 42-52, with no history of CVD, and not postmenopausal at baseline. VMS was defined by the number of days a woman reported VMS over the 2-week period before each annual visit. Frequent VMS was defined as >/=6 days of VMS; less frequent VMS was defined 1-5 days of symptoms with asymptomatic women the reference group. BP was measured at each visit in addition to demographic and clinic factors.

RESULTS: At baseline, 298 women reported frequent VMS, 794 less frequent VMS and 1747 no VMS. More frequent baseline VMS was associated with higher BP. Compared to no VMS, baseline VMS was associated with HTN (odds ratio [OR] 1.47, 95% confidence interval [CI]; 1.14-1.88 for infrequent VMS, and OR 1.40, (95% CI; 0.97-2.02 for frequent VMS). Risk for incident pre-HTN or HTN during follow-up was increased among women with frequent VMS (hazard ratio of 1.39, 95% CI; 1.09-1.79) after adjustment for multiple covariates.

CONCLUSION: Women with VMS may be more likely to develop HTN compared to women without VMS. Further research related to VMS including frequency of symptoms is warranted.

Five-year Safety Data from 5 Clinical Trials of Subcutaneous Golimumab in Patients with Rheumatoid Arthritis, Psoriatic Arthritis, and Ankylosing Spondylitis

Wed, 05/17/2017 - 8:28am

OBJECTIVE: Assess 5-year golimumab (GOL) safety in rheumatoid arthritis (RA), psoriatic arthritis (PsA), and ankylosing spondylitis (AS).

METHODS: Subcutaneous (SC) GOL (50 mg or 100 mg every 4 weeks) was evaluated in phase 3 trials of patients with active RA, PsA, and AS. Safety data through Year 5 were pooled across 3 RA trials [1 each evaluating methotrexate (MTX)-naive, MTX-experienced, and antitumor necrosis factor (TNF)-experienced patients], 1 PsA trial, and 1 AS trial. Data summarized was derived from both placebo-controlled (through weeks 24-52) and uncontrolled study periods. For adverse events (AE) of special interest [serious infections (SI), opportunistic infections (OI), deaths, malignancies, demyelination, tuberculosis (TB)], incidence per 100 patient-years (pt-yrs) was determined.

RESULTS: Across all trials, 639 patients received placebo and 2228 received SC GOL 50 mg only (n = 671), 50 mg and 100 mg (n = 765), or 100 mg only (n = 792). Safety followup extended for averages of 28.5 and 203.2 weeks for placebo and GOL, respectively. Respective placebo and GOL AE incidence/100 pt-yrs (95% CI) through Year 5 were 4.86 (2.83-7.78) and 3.29 (2.92-3.69) for SI, 0.00 (0.00-0.86) and 0.23 (0.14-0.35) for TB, 0.00 (0.00-0.86) and 0.22 (0.13-0.34) for OI, 0.00 (0.00-0.86) and 0.10 (0.05-0.20) for lymphoma, 0.00 (0.00-0.86) and 0.08 (0.03-0.17) for demyelination, and 0.29 (0.01-1.59) and 0.41 (0.29-0.57) for death. TB, OI, lymphoma, and demyelination incidence appeared to be higher among patients receiving GOL 100 mg only.

CONCLUSION: SC GOL safety through Year 5 remained consistent with previously reported Year 3 findings and with other TNF antagonists. Numerically higher incidences of TB, OI, lymphoma, and demyelination were observed with 100 mg versus 50 mg. Clinicaltrials.gov identifiers: NCT00264537 (GO-BEFORE), NCT00264550 (GO-FORWARD), NCT00299546 (GO-AFTER), NCT00265096 (GO-REVEAL), and NCT00265083 (GO-RAISE).

Differential Effects of Inflammation on Bone and Response to Biologics in Rheumatoid Arthritis and Spondyloarthritis

Wed, 05/17/2017 - 8:28am

PURPOSE OF REVIEW: We review the pathways, cytokines, and concepts important to the pathogenesis of bone resorption and formation in rheumatoid arthritis (RA) and spondyloarthritis (SpA).

RECENT FINDINGS: Research in bone biology has shed light on the pathogenesis of the joint destruction that occurs in RA and in peripheral SpA. However, understanding the mechanisms behind the bone formation seen in peripheral and axial SpA has been challenging. Mouse models have been used to gain an understanding of key signaling pathways, cytokines and cells regulating inflammation in these diseases. Biologic therapies directed against these targets have been developed to control both inflammation and effects on bone. Although biologic therapies improve joint inflammation in both RA and SpA, leading to a decrease in pain and improving quality of life for patients, the long-term effects of such therapies must also be evaluated by assessing their impact on structural progression. Inhibition of radiographic progression in both RA and peripheral SpA has been easier to demonstrate than in axial SpA. Here, we discuss the similarities and differences among biologic therapies as they pertain to radiographic progression.

Increased healthcare resource utilization in higher disease activity levels in initiators of TNF inhibitors among US rheumatoid arthritis patients

Wed, 05/17/2017 - 8:28am

OBJECTIVE: Determine healthcare resource utilization (HCRU) in biologic-naive initiators of TNF inhibitors (TNFis) associated with their disease activity from a national cohort of rheumatoid arthritis (RA) patients. METHODS: RA patients were identified at their first TNFi initiation (index date) in the Corrona registry. Patients with age of RA onset <18, comorbid psoriasis/psoriatic arthritis, fibromyalgia, or osteoarthritis were excluded. Patients were categorized into disease activity (DA) strata by the lowest level of DA (and sustaining low levels for at least two visits) using the Clinical Disease Activity Index (CDAI) across all visits in Corrona while on a TNFi during 1 year after initiation. Rates of all-cause and RA-related hospitalizations, rheumatologist visits, and joint surgeries while on TNFi therapy were reported and compared across DA levels along with the incidence rate ratio (IRR) adjusted for age, gender, and RA duration using Poisson mixed models. RESULTS: Of 1931 RA patients: 15% achieved sustained remission, 22% remission, 14% sustained low DA, 23% low DA and 27% moderate/high DA (M/HDA). Those in M/HDA had statistically higher rates of hospitalizations (37.3 per 100 patient years (py), 95% CI: 31.6-43.7 and joint surgeries (20.8 per 100 py, 95% CI: 16.6-25.8) compared to the sustained remission cohort, resulting in respective IRRs of 2.3 (p < 0.001) and 1.7 (p = 0.046). CONCLUSION: Many biologic naive RA patients initiating TNFi failed to achieve sustained remission during a 1 year period while remaining on TNFi therapy. Patients in higher DA levels had higher HCRU rates vs. patients in sustained remission, suggesting that achieving treat-to-target goals would reduce health care expenses.

RANK-Independent Osteoclast Formation and Bone Erosion in Inflammatory Arthritis

Wed, 05/17/2017 - 8:28am

OBJECTIVE: Proinflammatory molecules promote osteoclast-mediated bone erosion by up-regulating local RANKL production. However, recent evidence suggests that combinations of cytokines, such as tumor necrosis factor (TNF) plus interleukin-6 (IL-6), induce RANKL-independent osteoclastogenesis. The purpose of this study was to better understand TNF/IL-6-induced osteoclast formation and to determine whether RANK is absolutely required for osteoclastogenesis and bone erosion in murine inflammatory arthritis.

METHODS: Myeloid precursors from wild-type (WT) mice or mice with either germline or conditional deletion of Rank, Nfatc1, Dap12, or Fcrg were treated with either RANKL or TNF plus IL-6. Osteoprotegerin, anti-IL-6 receptor (anti-IL-6R), and hydroxyurea were used to block RANKL, the IL-6R, and cell proliferation, respectively. Clinical scoring, histologic assessment, micro-computed tomography, and quantitative polymerase chain reaction (qPCR) were used to evaluate K/BxN serum-transfer arthritis in WT and RANK-deleted mice. Loss of Rank was verified by qPCR and by osteoclast cultures.

RESULTS: TNF/IL-6 generated osteoclasts in vitro that resorbed mineralized tissue through a pathway dependent on IL-6R, NFATc1, DNAX-activation protein 12, and cell proliferation, but independent of RANKL or RANK. Bone erosion and osteoclast formation were reduced, but not absent, in arthritic mice with inducible deficiency of RANK. TNF/IL-6, but not RANKL, induced osteoclast formation in bone marrow and synovial cultures from animals deficient in Rank. Multiple IL-6 family members (IL-6, leukemia inhibitory factor, oncostatin M) were up-regulated in the synovium of arthritic mice.

CONCLUSION: The persistence of bone erosion and synovial osteoclasts in Rank-deficient mice, and the ability of TNF/IL-6 to induce osteoclastogenesis, suggest that more than one cytokine pathway exists to generate these bone-resorbing cells in inflamed joints.

Comparative effectiveness of abatacept versus tocilizumab in rheumatoid arthritis patients with prior TNFi exposure in the US Corrona registry

Wed, 05/17/2017 - 8:28am

BACKGROUND:

We compared the effectiveness of abatacept (ABA) vs tocilizumab (TCA) in tumor necrosis factor inhibitor (TNFi) experienced patients. METHODS:

We identified rheumatoid arthritis (RA) patients from a large observational US cohort (1 January 2010-31 May 2014) who had discontinued at least one TNFi and initiated ABA or TCZ in moderate or high disease activity based on the Clinical Disease Activity Index (CDAI) and had no prior exposure to the comparator drug. Using propensity score matching (1:1) stratified by prior TNF use (1 TNFi vs ≥2 TNFis), effectiveness at 6 months after initiation was evaluated. Mean change in CDAI over 6 months following initiation was the primary outcome, with secondary outcomes of achievement of low disease activity/remission (CDAI ≤ 10) and mean change in modified Health Assessment Questionnaire (mHAQ) score. RESULTS:

The 264 pairs of propensity score-matched ABA and TCZ initiators were well matched with no substantial differences in the baseline characteristics, defined as standardized differences >0.1 in the stratification. Both treatment groups had similar mean change in CDAI at 6 months (-11.3 in ABA vs -9.9 in TCZ; mean difference -1.27, 95% CI -3.65, 1.11). Similar proportions of both treatment groups achieved low disease activity/remission (adjusted odds ratio for ABA vs TCZ 0.99, 95% CI 0.69, 1.43). Mean change in mHAQ was -0.12 in ABA initiators vs -0.11 in TCZ initiations (mean difference -0.01, 95% CI -0.09, 0.06). CONCLUSIONS:

Patients receiving either ABA or TCZ had substantial improvement in clinical disease activity. In this propensity score-matched sample, similar outcomes were observed for both treatment cohorts.

Reducing Suicide Risk: Challenges and Opportunities in the Emergency Department

Wed, 05/17/2017 - 8:28am

Emergency departments (ED) are prime locations for identifying individuals at high risk of suicide and for making life-saving interventions. In an ideal scenario, all ED patients at risk of suicide could be identified and connected with effective, feasible interventions, and this would occur in a supportive system not overburdened by screening or assessment requirements. In this review, we focus on challenges to achieving this ideal--along with potential solutions--at the level of patients, providers, the ED environment, and the larger health care system. .

Poster Session Program: 2017 UMass Center for Clinical and Translational Science Research Retreat

Tue, 05/16/2017 - 4:45pm

Poster Session Program for the 7th annual UMass Center for Clinical and Translational Science Research Retreat, held Tuesday, May 16, 2017 at the University of Massachusetts Medical School, Worcester, MA.

View poster abstracts

A microRNA family exerts maternal control on sex determination in C. elegans

Tue, 05/16/2017 - 2:06pm

Gene expression in early animal embryogenesis is in large part controlled post-transcriptionally. Maternally contributed microRNAs may therefore play important roles in early development. We elucidated a major biological role of the nematode mir-35 family of maternally contributed essential microRNAs. We show that this microRNA family regulates the sex determination pathway at multiple levels, acting both upstream of and downstream from her-1 to prevent aberrantly activated male developmental programs in hermaphrodite embryos. Both of the predicted target genes that act downstream from the mir-35 family in this process, suppressor-26 (sup-26) and NHL (NCL-1, HT2A, and LIN-41 repeat) domain-containing-2 (nhl-2), encode RNA-binding proteins, thus delineating a previously unknown post-transcriptional regulatory subnetwork within the well-studied sex determination pathway of Caenorhabditis elegans Repression of nhl-2 by the mir-35 family is required for not only proper sex determination but also viability, showing that a single microRNA target site can be essential. Since sex determination in C. elegans requires zygotic gene expression to read the sex chromosome karyotype, early embryos must remain gender-naïve; our findings show that the mir-35 family microRNAs act in the early embryo to function as a developmental timer that preserves naïveté and prevents premature deleterious developmental decisions.

Genomic landscape of colorectal cancer in Japan: clinical implications of comprehensive genomic sequencing for precision medicine

Tue, 05/16/2017 - 12:44pm

BACKGROUND: Comprehensive genomic sequencing (CGS) has the potential to revolutionize precision medicine for cancer patients across the globe. However, to date large-scale genomic sequencing of cancer patients has been limited to Western populations. In order to understand possible ethnic and geographic differences and to explore the broader application of CGS to other populations, we sequenced a panel of 415 important cancer genes to characterize clinically actionable genomic driver events in 201 Japanese patients with colorectal cancer (CRC).

METHODS: Using next-generation sequencing methods, we examined all exons of 415 known cancer genes in Japanese CRC patients (n = 201) and evaluated for concordance among independent data obtained from US patients with CRC (n = 108) and from The Cancer Genome Atlas-CRC whole exome sequencing (WES) database (n = 224). Mutation data from non-hypermutated Japanese CRC patients were extracted and clustered by gene mutation patterns. Two different sets of genes from the 415-gene panel were used for clustering: 61 genes with frequent alteration in CRC and 26 genes that are clinically actionable in CRC.

RESULTS: The 415-gene panel is able to identify all of the critical mutations in tumor samples as well as WES, including identifying hypermutated tumors. Although the overall mutation spectrum of the Japanese patients is similar to that of the Western population, we found significant differences in the frequencies of mutations in ERBB2 and BRAF. We show that the 415-gene panel identifies a number of clinically actionable mutations in KRAS, NRAS, and BRAF that are not detected by hot-spot testing. We also discovered that 26% of cases have mutations in genes involved in DNA double-strand break repair pathway. Unsupervised clustering revealed that a panel of 26 genes can be used to classify the patients into eight different categories, each of which can optimally be treated with a particular combination therapy.

CONCLUSIONS: Use of a panel of 415 genes can reliably identify all of the critical mutations in CRC patients and this information of CGS can be used to determine the most optimal treatment for patients of all ethnicities.

Regulatory T Cells in Endemic Burkitt Lymphoma Patients Are Associated with Poor Outcomes: A Prospective, Longitudinal Study

Tue, 05/16/2017 - 12:44pm

Deficiencies in Epstein-Barr virus (EBV)-specific T cell immunosurveillance appear to precede the development of endemic Burkitt lymphoma (eBL), a malaria-associated pediatric cancer common in sub-Saharan Africa. However, T cell contributions to eBL disease progression and survival have not been characterized. Our objective was to investigate regulatory and inflammatory T cell responses in eBL patients associated with clinical outcomes. By multi-parameter flow cytometry, we examined peripheral blood mononuclear cells from 38 eBL patients enrolled in a prospective cohort study in Kisumu, Kenya from 2008-2010, and 14 healthy age-matched Kenyan controls. Children diagnosed with eBL were prospectively followed and outcomes categorized as 2-year event-free survivors, cases of relapses, or those who died. At the time of diagnosis, eBL children with higher CD25+Foxp3+ regulatory T (Treg) cell frequencies were less likely to survive than patients with lower Treg frequencies (p = 0.0194). Non-survivors also had higher absolute counts of CD45RA+Foxp3lo naive and CD45RA-Foxp3hi effector Treg subsets compared to survivors and healthy controls. Once patients went into clinical remission, Treg frequencies remained low in event-free survivors. Patients who relapsed, however, showed elevated Treg frequencies months prior to their adverse event. Neither concurrent peripheral blood EBV load nor malaria infection could explain higher Treg cell frequencies. CD8+ T cell PD-1 expression was elevated in all eBL patients at time of diagnosis, but relapse patients tended to have persistently high PD-1 expression compared to long-term survivors. Non-survivors produced more CD4+ T-cell IL-10 in response to both Epstein-Barr Nuclear Antigen-1 (EBNA-1) (p = 0.026) and the malaria antigen Plasmodium falciparum Schizont Egress Antigen-1 (p = 0.0158) compared to survivors, and were concurrently deficient in (EBNA-1)-specific CD8+ T-cell derived IFN-gamma production (p = 0.002). In addition, we identified the presence of Foxp3-IL10+ regulatory Type 1 cells responding to EBNA-1 in contrast to the malaria antigen tested. These novel findings suggest that poor outcomes in eBL patients are associated with a predominantly immuno-regulatory environment. Therefore, Treg frequencies could be a predictive biomarker of disease progression and manipulation of Treg activity has potential as a therapeutic target to improve eBL survival.

A Sema3C Mutant Resistant to Cleavage by Furin (FR-Sema3C) Inhibits Choroidal Neovascularization

Tue, 05/16/2017 - 12:44pm

In age-related macular degeneration (AMD), abnormal sub retinal choroidal neovascularization (CNV) is a major cause of blindness. FR-sema3C is a point mutated form of semaphorin-3C that is resistant to cleavage by furin like pro-protein convertases (FPPC). We have found in previous work that FR-sema3C functions as an anti-angiogenic factor. In this study we investigated the possible use of FR-sema3C as an inhibitor of CNV. FR-sema3C inhibits VEGF as well as PDGF-BB signal transduction in endothelial cells and to less extent bFGF induced signal transduction using a mechanism that does not depend upon the binding of VEGF like the drugs that are currently the mainstay treatment for AMD. CNV was induced in eyes of C57 black mice by laser photocoagulation. Intravitreal injection of FR-Sema3C or aflibercept (VEGF-trap) was then used to inhibit CNV formation. Invading choroidal vessels were visualized a week later by injection of FITC-dextran into the circulation, followed by the measurement of the area of the invading blood vessels. Injection of 0.1 mug FR-Sema3C inhibited CNV by 55% (P<0.01) and was as effective as 5 mug aflibercept. FR-sema3C did not display any adverse effects on retinal function following its injection into eyes of healthy mice as assessed by optokinetic reflex (OKR) and Electro-retinogram (ERG) criteria. Furthermore, FR-sema3C did not induce apoptosis in the retina as determined by TUNEL nor was there any discernable structural damage to the retina as assessed by several immuno-histochemical criteria. Our results suggest that FR-sema3C could perhaps be used for the treatment of AMD, and that it may perhaps be of benefit to patients that do not respond well to current treatments relying on VEGF sequestering agents.

Anticonvulsive Effects of Licofelone on Status Epilepticus Induced by Lithium-pilocarpine in Wistar Rats: a Role for Inducible Nitric Oxide Synthase

Tue, 05/16/2017 - 12:44pm

BACKGROUND AND PURPOSE: Status epilepticus (SE) is a neurological disorder with high prevalence and mortality rates, requiring immediate intervention. Licofelone is a cyclooxygenase (COX) and 5-lipoxygenase (5-LOX) inhibitor, which its effectiveness to treat osteoarthritis has been approved. Increasing evidence suggests an involvement of COX and LOX enzymes in epileptic disorders. Thus, in the present study we investigate possible effects of licofelone on prevention and termination of SE. We also evaluated whether the nitrergic system could participate in this effect of licofelone.

METHODS: We have utilized lithium-pilocarpine model of SE in adult Wistar rats to assess the potential effect of licofelone on seizure susceptibility. Licofelone was administered 1 h before pilocarpine. To evaluate probable role of nitric oxide (NO) system, L-arginine (60 mg/kg, i.p.), as a NO precursor; L-NAME (15 mg/kg, i.p.), as a non-selective nitric oxide synthase (NOS) inhibitor; aminoguanidine (100 mg/kg, i.p.), as an inducible NOS (iNOS) inhibitor and 7-nitroindazole (60 mg/kg, i.p.), as a neuronal NOS inhibitor were injected 15 min before licofelone. Also, licofelone and diazepam 10 mg/kg were administered 30 minutes after onset of SE.

RESULTS: Pre-treatment with licofelone at the dosage of 10 mg/kg, significantly prevented the onset of SE in all subjects (p < 0.001). L-arginine significantly inverted this anticonvulsant effect (p < 0.05). However, L-NAME and aminoguanidine, potentiated the anticonvulsant effect of licofelone (p < 0.05, p < 0.01). Licofelone could not terminate seizures after onset which was terminated by diazepam.

CONCLUSIONS: Our findings showed that anticonvulsive effects of licofelone on SE could be mediated by iNOS. Also, we suggest that COX/5-LOX activation is possibly required in the initial stage of onset but SE recruits extra excitatory pathways with prolongation.

Humanized Mouse Models of Clinical Disease

Tue, 05/16/2017 - 12:44pm

Immunodeficient mice engrafted with functional human cells and tissues, that is, humanized mice, have become increasingly important as small, preclinical animal models for the study of human diseases. Since the description of immunodeficient mice bearing mutations in the IL2 receptor common gamma chain (IL2rgnull) in the early 2000s, investigators have been able to engraft murine recipients with human hematopoietic stem cells that develop into functional human immune systems. These mice can also be engrafted with human tissues such as islets, liver, skin, and most solid and hematologic cancers. Humanized mice are permitting significant progress in studies of human infectious disease, cancer, regenerative medicine, graft-versus-host disease, allergies, and immunity. Ultimately, use of humanized mice may lead to the implementation of truly personalized medicine in the clinic. This review discusses recent progress in the development and use of humanized mice and highlights their utility for the study of human diseases.