CUP-1 Is a Novel Protein Involved in Dietary Cholesterol Uptake in Caenorhabditis elegans

Sterols transport and distribution are essential processes in all multicellular organisms. Survival of the nematode Caenorhabditis elegans depends on dietary absorption of sterols present in the environment. However the general mechanisms associated to sterol uptake in nematodes are poorly understood. In the present work we provide evidence showing that a previously uncharacterized transmembrane protein, designated Cholesterol Uptake Protein-1 (CUP-1), is involved in dietary cholesterol uptake in C. elegans. Animals lacking CUP-1 showed hypersensitivity to cholesterol limitation and were unable to uptake cholesterol. A CUP-1-GFP fusion protein colocalized with cholesterol-rich vesicles, endosomes and lysosomes as well as the plasma membrane. Additionally, by FRET imaging, a direct interaction was found between the cholesterol analog DHE and the transmembrane “cholesterol recognition/interaction amino acid consensus” (CRAC) motif present in C. elegans CUP-1. In-silico analysis identified two mammalian homologues of CUP-1. Most interestingly, CRAC motifs are conserved in mammalian CUP-1 homologous. Our results suggest a role of CUP-1 in cholesterol uptake in C. elegans and open up the possibility for the existence of a new class of proteins involved in sterol absorption in mammals

Deoxycholate induces COX-2 expression via Erk1/2-, p38-MAPK and AP-1-dependent mechanisms in esophageal cancer cells

<p>Abstract</p> <p>Background</p> <p>The progression from Barrett's metaplasia to adenocarcinoma is associated with the acquirement of an apoptosis-resistant phenotype. The bile acid deoxycholate (DCA) has been proposed to play an important role in the development of esophageal adenocarcinoma, but the precise molecular mechanisms remain undefined. The aim of this study was to investigate DCA-stimulated COX-2 signaling pathways and their possible contribution to deregulated cell survival and apoptosis in esophageal adenocarcinoma cells.</p> <p>Methods</p> <p>Following exposure of SKGT-4 cells to DCA, protein levels of COX-2, MAPK and PARP were examined by immunoblotting. AP-1 activity was assessed by mobility shift assay. DCA-induced toxicity was assessed by DNA fragmentation and MTT assay.</p> <p>Results</p> <p>DCA induced persistent activation of the AP-1 transcription factor with Fra-1 and JunB identified as the predominant components of the DCA-induced AP-1 complex. DCA activated Fra-1 via the Erk1/2- and p38 MAPK while Erk1/2 is upstream of JunB. Moreover, DCA stimulation mediated inhibition of proliferation with concomitant low levels of caspase-3-dependent PARP cleavage and DNA fragmentation. Induction of the anti-apoptotic protein COX-2 by DCA, via MAPK/AP-1 pathway appeared to balance the DCA mediated activation of pro-apoptotic markers such as PARP cleavage and DNA fragmentation. Both of these markers were increased upon COX-2 suppression by aspirin pretreatment prior to DCA exposure.</p> <p>Conclusion</p> <p>DCA regulates both apoptosis and COX-2-regulated cell survival in esophageal cells suggesting that the balance between these two opposing signals may determine the transformation potential of DCA as a component of the refluxate.</p

A multiscale systems perspective on cancer, immunotherapy, and Interleukin-12

Monoclonal antibodies represent some of the most promising molecular targeted immunotherapies. However, understanding mechanisms by which tumors evade elimination by the immune system of the host presents a significant challenge for developing effective cancer immunotherapies. The interaction of cancer cells with the host is a complex process that is distributed across a variety of time and length scales. The time scales range from the dynamics of protein refolding (i.e., microseconds) to the dynamics of disease progression (i.e., years). The length scales span the farthest reaches of the human body (i.e., meters) down to the range of molecular interactions (i.e., nanometers). Limited ranges of time and length scales are used experimentally to observe and quantify changes in physiology due to cancer. Translating knowledge obtained from the limited scales observed experimentally to predict patient response is an essential prerequisite for the rational design of cancer immunotherapies that improve clinical outcomes. In studying multiscale systems, engineers use systems analysis and design to identify important components in a complex system and to test conceptual understanding of the integrated system behavior using simulation. The objective of this review is to summarize interactions between the tumor and cell-mediated immunity from a multiscale perspective. Interleukin-12 and its role in coordinating antibody-dependent cell-mediated cytotoxicity is used illustrate the different time and length scale that underpin cancer immunoediting. An underlying theme in this review is the potential role that simulation can play in translating knowledge across scales

Quantitative and Qualitative Analysis of Blood-based Liquid Biopsies to Inform Clinical Decision-making in Prostate Cancer

Context: Genomic stratification can impact prostate cancer (PC) care through diagnostic, prognostic, and predictive biomarkers that aid in clinical decision-making. The temporal and spatial genomic heterogeneity of PC together with the challenges of acquiring metastatic tissue biopsies hinder implementation of tissue-based molecular profiling in routine clinical practice. Blood-based liquid biopsies are an attractive, minimally invasive alternative. Objective: To review the clinical value of blood-based liquid biopsy assays in PC and identify potential applications to accelerate the development of precision medicine. Evidence acquisition: A systematic review of PubMed/MEDLINE was performed to identify relevant literature on blood-based circulating tumor cells (CTCs), circulating tumor DNA (ctDNA), and extracellular vesicles (EVs) in PC. Evidence synthesis: Liquid biopsy has emerged as a practical tool to profile tumor dynamics over time, elucidating features that evolve (genome, epigenome, transcriptome, and proteome) with tumor progression. Liquid biopsy tests encompass analysis of DNA, RNA, and proteins that can be detected in CTCs, ctDNA, or EVs. Blood-based liquid biopsies have demonstrated promise in the context of localized tumors (diagnostic signatures, risk stratification, and disease monitoring) and advanced disease (response/resistance biomarkers and prognostic markers). Conclusions: Liquid biopsies have value as a source of prognostic, predictive, and response biomarkers in PC. Most clinical applications have been developed in the advanced metastatic setting, where CTC and ctDNA yields are significantly higher. However, standardization of assays and analytical/clinical validation is necessary prior to clinical implementation. Patient summary: Traces of tumors can be isolated from blood samples from patients with prostate cancer either as whole cells or as DNA fragments. These traces provide information on tumor features. These minimally invasive tests can guide diagnosis and treatment selection

Efeito do estradiol, dietas e duração do período seco sobre o consumo de matéria seca de vacas holandesas Effect of estradiol, diets and lenght of the dry period on feed intake of holstein cows

Foram avaliados os efeitos de dietas aniônicas (DA) e catiônicas (DC), associadas ou não ao uso de estradiol em dois períodos secos: período seco curto (30 dias) (PSC) e período seco regular (60 dias) (PSR) sobre o consumo de matéria seca (MS) de 40 vacas Holandesas, nos períodos pré-parto (PREP) e pós-parto (PP), distribuídas aleatoriamente em esquema fatorial 2x2+2. As dietas foram fornecidas por 21 dias no período pré-parto, após o qual, as vacas passaram a receber uma dieta de lactação. As DA não tiveram efeito sobre o consumo de MS no PREP; entretanto, resultaram em maior consumo quando comparadas à DC no pós-parto. Os contrastes entre tratamentos mostraram que DA fornecidas no PREP produziram aumento no consumo PP, PSR e no PSC associadas ao estradiol (P<0,01), sugerindo o efeito das DA sobre a mais rápida recuperação do consumo no PP; entretanto, essas no PSC sem estradiol resultaram em consumos semelhantes (P>0,05). Quando se comparam dietas com estradiol associado ao PSC com as demais, as primeiras apresentaram menores consumos, o que significa que a utilização de estrógenos exógenos pode reduzir o consumo no pós-parto. Não foram observadas diferenças entre consumo no PSC sem estradiol quando comparado ao PSR. O número de dias que antecederam o parto produziram efeito cúbico sobre o consumo (P<0,01), com aumento desse consumo logo na primeira semana pós-parto. Tanto o consumo no PRE, quanto no PP, foram menores na estação 2 (temperaturas acima de 260 C), quando comparados com a estação 1 (temperaturas abaixo de 260C) (P<0,01). Embora não tenha sido detectada diferença entre tratamentos no consumo no PREP, o uso de estradiol no PREP pode causar redução no consumo PP, e as vacas secas por 60 dias, que consumiram dietas aniônicas, apresentaram maiores consumos no PP, sugerindo sua efetividade sobre o controle da hipocalcemia.<br>The effects of anionic and cationic diets, associated or not with estradiol injection, and two dry periods (30 days and 60 days), were evaluated in dry matter intake in prepartum and postpartum. The trial was undertaken at Dairy Research Unit of Florida University, in Gainesville, USA. Forty Holstein cows were randomly assigned to the treatments in a factorial design: 1. anionic diet, 30 days dry period (AD30) 2. cationic diet, 30 days dry period (CD30), 3. anionic diet, 30 days dry period plus estradiol (AD30E) 4. cationic diet, 30 days dry period plus estradiol (CD30E); 5.anionic diet, 60 days dry period (AD60); 6. cationic diet, 60 days dry period (CD60). After calving, a standard early lactation diet was fed to all cows for 21 days. The cows were under two different range of temperatures: up to 260C, that calved in Autumn (season 1) and over 260C, (extreme temperatures) and calved in summer (season 2). AD did not affect prepartum feed intake, however it increases intake when compared to CA in postpartum. The contrasts between treatments showed AD increased postpartum intake in 60 days period (P<0.01) and in 30 days period only when associated with estradiol (P<0.01), suggesting that AD comes the cows faster to feeding, however, AD30 did not affect feed intake, and contrast was not significant (P>0,05).When diets associated with estradiol (AD30E and CD30E) were contrasted with the others, they showed lower intakes, what means that exogenous estrogen reduces postpartum intake. No differences were observed when 30 days period without estradiol injection were compared to sixty days dry period. The days in relation to peripartum showed cubic effects on intake (P<0,01), increasing the intake in the first week postpartum. Both feed intake in prepartum and postpartum decreased in season 2, when contrasted to season 1 (P<0,01). In conclusion, however differences between treatments were not detected in prepartum, estradiol injection in prepartum can decrease feed intake

Estrogen reprograms the activity of neutrophils to foster protumoral microenvironment during mammary involution

Epidemiological studies have indicated increased risk for breast cancer within 10 years of childbirth. Acute inflammation during mammary involution has been suggested to promote this parity-associated breast cancer. We report here that estrogen exacerbates mammary inflammation during involution. Microarray analysis shows that estrogen induces an extensive proinflammatory gene signature in the involuting mammary tissue. This is associated with estrogen-induced neutrophil infiltration. Furthermore, estrogen induces the expression of protumoral cytokines/chemokines, COX-2 and tissue-remodeling enzymes in isolated mammary neutrophils and systemic neutrophil depletion abolished estrogen-induced expression of these genes in mammary tissue. More interestingly, neutrophil depletion diminished estrogen-induced growth of ERα-negative mammary tumor 4T1 in Balb/c mice. These findings highlight a novel aspect of estrogen action that reprograms the activity of neutrophils to create a pro-tumoral microenvironment during mammary involution. This effect on the microenvironment would conceivably aggravate its known neoplastic effect on mammary epithelial cells.MOE (Min. of Education, S’pore)Published versio

Unravelling Stakeholder Perceptions to Enable Adaptive Water Governance in Dryland Systems

Adaptive water governance seeks to increase a social-ecological system’s adaptive capacity in the face of uncertainty and change. This is especially important in non-linear dryland systems that are already exposed to water scarcity and increasing degradation. Conservation of water ecosystem services is key for increasing adaptive capacity in drylands, however, how stakeholders perceive water ecosystem services greatly affects how they are managed, as well as the potential for adaptive water governance. This paper focuses on identifying the system’s potential for enabling adaptive water governance by analysing different stakeholder perceptions on water ecosystem services. It takes the Rio del Carmen watershed as a case study, offering important insights for an increasing number of water-scarce regions. Semi-structured interviews were conducted with key stakeholders in the watershed in order to unravel their perceptions and understand the governance context. We found disparities in how stakeholders perceive water ecosystem services have led to water overexploitation and several conflicts over water access. Our results indicate that stakeholder perceptions have a major influence on the system’s adaptability, as they shape the acquisition of water ecosystem services. Divergent stakeholder perceptions act as an important barrier to collaboration. Generating and sharing knowledge could facilitate the development of a common vision, allowing all actors to co-create information about water ecosystem services and the system state, engaging them in a participatory process, suitable for their context, and that will better support adaptive water governance

Chromatin remodeling by the SWI/SNF-like BAF complex and STAT4 activation synergistically induce IL-12Rbeta2 expression during human Th1 cell differentiation.

Interleukin-12 (IL-12) is a key cytokine for the development of T helper type 1 (Th1) responses; however, naive CD4(+) T cells do not express IL-12Rbeta2, and are therefore unresponsive to IL-12. We have examined the mechanisms that control Th1-specific expression of the human IL-12Rbeta2 gene at early time points after T-cell stimulation. We have identified a Th1-specific enhancer element that binds signal transducer and activator of transcription 4 (STAT4) in vivo in developing Th1 but not Th2 cells. T-cell receptor (TCR) signaling induced histone hyperacetylation and recruitment of BRG1, the ATPase subunit of the SWI/SNF-like BAF chromatin remodeling complex, to the IL-12Rbeta2 regulatory regions and was associated with low-level gene transcription at the IL-12Rbeta2 locus. However, high-level IL-12Rbeta2 expression required TCR triggering in the presence of IL-12. Our results indicate a synergistic role of TCR-induced chromatin remodeling and cytokine-induced STAT4 activation to direct IL-12Rbeta2 expression during Th1 cell development