Regulation of expression of the rat CYP2B1 and CYP2B2 genes

CYP2B1 and CYP2B2 proteins are highly induced in rat liver by phenobarbital (PB). CYP2B1 promoter sequences from -179 to -347 bp and -348 to -451 bp were observed in gel shift assays to bind liver nuclear protein that was either more abundant or activated from PB-treated than untreated rats. The DNA-binding activity of the protein bound to the sequence between -348 and -451 bp was enhanced when liver nuclear extracts from both untreated and PB-treated rats were treated with ATP prior to gel shift assays. While pre-treatment with either calf intestinal alkaline phosphatase (CIP) or 2-aminopurine (2-AP), a general protein kinase inhibitor inhibited complex formation. Thus, phosphorylation of this protein increases its binding to DNA and dephosphorylation inhibits binding. When primary hepatocytes or whole animals were treated with 2-aminopurine, it could totally suppress both basal and PB-induced CYP2B mRNAs expression in vitro but only partially suppress PB-induction of CYP2B mRNAs in vivo. A PB-responsive element (PBRE) has been identified in the distal region of the CYP2B2 promoter. The homologous region in the CYP2B1 promoter between -2142 and -2301 bp was cloned into a reporter gene construct and was shown to confer PB-responsiveness to the luciferase gene when transfected either into primary rat hepatocytes or directly into rat liver tissues. A higher fold induction was observed with in vivo DNA transfection. The PBRE sequence could activate gene expression better when the -348 to -451 bp sequence was included in the promoter region of the reporter construct. The CYP2B2 promoter, between -183 and -199 bp, also bound more liver nuclear protein from PB-treated rats in gel shift assay. An octamer consensus oligonucleotide competed for protein binding to this region. An antibody which recognised the DNA-binding domain of Oct-1 and Oct-2 inhibited complex formation and an Oct-1 specific antibody supershifted the protein-DNA complex

The Sweet Surrender: How Myeloid Cell Metabolic Plasticity Shapes the Tumor Microenvironment

Immune cells are one of the most versatile cell types, as they can tailor their metabolic activity according to their required function. In response to diverse environmental cues, immune cells undergo metabolic reprogramming to support their differentiation, proliferation and pro-inflammatory effector functions. To meet a dramatic surge in energetic demand, immune cells rewire their metabolism to utilize aerobic glycolysis. This preferential use of glycolysis even under aerobic conditions is well established in tumor cells, and is known as the “Warburg effect.” Tumor cells avidly use glucose for aerobic glycolysis, thereby creating a nutrient-starved microenvironment, outcompeting T cells for glucose, and directly inhibiting T-cell anti-tumoral effector function. Given that both immune and tumor cells use similar modes of metabolism in the tumor stroma, it is imperative to identify a therapeutic window in which immune-cell and tumor-cell glycolysis can be specifically targeted. In this review, we focus on the Warburg metabolism as well as other metabolic pathways of myeloid cells, which comprise a notable niche in the tumor environment and promote the growth and metastasis of malignant tumors. We examine how differential immune-cell activation triggers metabolic fate, and detail how this forbidding microenvironment succeeds in shutting down the vigorous anti-tumoral response. Finally, we highlight emerging therapeutic concepts that aim to target immune-cell metabolism. Improving our understanding of immunometabolism and immune-cell commitment to specific metabolic fates will help identify alternative therapeutic approaches to battle this intractable disease

Challenges and Achievements of Senior Citizen Pursuing Open and Distance Learning

In the era of technology and borderless world, open and distance learning has become a choice for many adults who wish to pursue tertiary education. In responding to this development, many higher education institutions, including Open University Malaysia, have designed various academic programmes to meet the needs of adult learners. Senior citizens naturally experience a decline in their physical, cognitive, motor and memory abilities. Despite having to face such challenges, many senior citizens have enrolled at the Open University Malaysia. The objective of this study is to examine their academic performance, analyse it by gender, age and zone of learning centres; and identify the issues and challenges they faced. Senior citizens who graduated from two schools, the Faculty of Applied Social Sciences (now known as Cluster of Education and Social Sciences) and OUM Business School (now known as Cluster of Business and Management), were included in this study. Secondary data was used to analyse learners’ academic performance while interviews were conducted to identify the challenges they faced. The findings indicated that they had faced difficulties in relation to their health and information technology skills but still performed well. (Abstract by authors

Contact-dependent carcinoma aggregate dispersion by M2a macrophages via ICAM-1 and β2 integrin interactions

Tumor-associated macrophages (TAMs) can constitute up to 50% of the tumor mass and have strong implications in tumor progression and metastasis. Macrophages are plastic and can polarize to various subtypes that differ in terms of surface receptor expression as well as cytokine and chemokine production and effector function. Conventionally, macrophages are grouped into two major subtypes: the classically activated M1 macrophages and the alternatively activated M2 macrophages. M1 macrophages are pro-inflammatory, promote T helper (Th) 1 responses, and show tumoricidal activity, whereas M2 macrophages contribute to tissue repair and promote Th2 responses. Herein, we present a microfluidic system integrating tumor cell aggregates and subtypes of human monocyte-derived macrophages in a three-dimensional hydrogel scaffold, in close co-culture with an endothelial monolayer to create an in vitro tumor microenvironment. This platform was utilized to study the role of individual subtypes of macrophages (M0, M1, M2a, M2b and M2c) in human lung adenocarcinoma (A549) aggregate dispersion, as a representation of epithelial-mesenchymal transition (EMT). A significant difference was observed when M2a macrophages were in direct contact with or separated from A549 aggregates, suggesting a possible mechanism for proximity-induced, contact-dependent dissemination via ICAM-1 and integrin β2 interactions. Indeed, M2a macrophages tended to infiltrate and release cells from carcinoma cell aggregates. These findings may help in the development of immunotherapies based on enhancing the tumor-suppressive properties of TAMs.Singapore-MIT Alliance for Research and Technology (SMART - BioSym IRG)National University of Singapore. Biochemistry departmentSingapore. Biomedical Research CouncilSingapore. Agency for Science, Technology and Researc

Will the US Economy Recover in 2010? A Minimal Spanning Tree Study

We calculated the cross correlations between the half-hourly times series of the ten Dow Jones US economic sectors over the period February 2000 to August 2008, the two-year intervals 2002--2003, 2004--2005, 2008--2009, and also over 11 segments within the present financial crisis, to construct minimal spanning trees (MSTs) of the US economy at the sector level. In all MSTs, a core-fringe structure is found, with consumer goods, consumer services, and the industrials consistently making up the core, and basic materials, oil and gas, healthcare, telecommunications, and utilities residing predominantly on the fringe. More importantly, we find that the MSTs can be classified into two distinct, statistically robust, topologies: (i) star-like, with the industrials at the center, associated with low-volatility economic growth; and (ii) chain-like, associated with high-volatility economic crisis. Finally, we present statistical evidence, based on the emergence of a star-like MST in Sep 2009, and the MST staying robustly star-like throughout the Greek Debt Crisis, that the US economy is on track to a recovery.Comment: elsarticle class, includes amsmath.sty, graphicx.sty and url.sty. 68 pages, 16 figures, 8 tables. Abridged version of the manuscript presented at the Econophysics Colloquim 2010, incorporating reviewer comment

Susceptibility and Response of Human Blood Monocyte Subsets to Primary Dengue Virus Infection

Human blood monocytes play a central role in dengue infections and form the majority of virus infected cells in the blood. Human blood monocytes are heterogeneous and divided into CD16− and CD16+ subsets. Monocyte subsets play distinct roles during disease, but it is not currently known if monocyte subsets differentially contribute to dengue protection and pathogenesis. Here, we compared the susceptibility and response of the human CD16− and CD16+ blood monocyte subsets to primary dengue virus in vitro. We found that both monocyte subsets were equally susceptible to dengue virus (DENV2 NGC), and capable of supporting the initial production of new infective virus particles. Both monocyte subsets produced anti-viral factors, including IFN-α, CXCL10 and TRAIL. However, CD16+ monocytes were the major producers of inflammatory cytokines and chemokines in response to dengue virus, including IL-1β, TNF-α, IL-6, CCL2, 3 and 4. The susceptibility of both monocyte subsets to infection was increased after IL-4 treatment, but this increase was more profound for the CD16+ monocyte subset, particularly at early time points after virus exposure. These findings reveal the differential role that monocyte subsets might play during dengue disease

Systematic comparison of plasma EBV DNA, anti-EBV antibodies and miRNA levels for early detection and prognosis of nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is originated from the epithelial cells of nasopharynx, Epstein-Barr virus (EBV)-associated and has the highest incidence and mortality rates in Southeast Asia. Late presentation is a common issue and early detection could be the key to reduce the disease burden. Sensitivity of plasma EBV DNA, an established NPC biomarker, for Stage I NPC is controversial. Most newly reported NPC biomarkers have neither been externally validated nor compared to the established ones. This causes difficulty in planning for cost-effective early detection strategies. Our study systematically evaluated six established and four new biomarkers in NPC cases, population controls and hospital controls. We showed that BamHI-W 76 bp remains the most sensitive plasma biomarker, with 96.7% (29/30), 96.7% (58/60) and 97.4% (226/232) sensitivity to detect Stage I, early stage and all NPC, respectively. Its specificity was 94.2% (113/120) against population controls and 90.4% (113/125) against hospital controls. Diagnostic accuracy of BamHI-W 121 bp and ebv-miR-BART7-3p were validated. Hsa-miR-29a-3p and hsa-miR-103a-3p were not, possibly due to lower number of advanced stage NPC cases included in this subset. Decision tree modeling suggested that combination of BamHI-W 76 bp and VCA IgA or EA IgG may increase the specificity or sensitivity to detect NPC. EBNA1 99 bp could identify NPC patients with poor prognosis in early and advanced stage NPC. Our findings provided evidence for improvement in NPC screening strategies, covering considerations of opportunistic screening, combining biomarkers to increase sensitivity or specificity and testing biomarkers from single sampled specimen to avoid logistic problems of resampling