Uncovering Dual Roles for PERK Signaling During Experimentally Induced Pancreatitis

Pancreatitis is characterized by inappropriate activation of digestive enzyme precursors, or zymogens, local and systemic inflammation, dysregulation of cellular calcium (Ca2+), and induction of the unfolded protein response (UPR). The UPR consists of three distinct pathways all of which are activated during pancreatitis. However, the molecular roles of each remain unclear. The protein kinase RNA (PKR)-like ER kinase (PERK) pathway reduces general protein translation by phosphorylating eIF2!, and is activated within minutes of initiating pancreatic damage. Microarray analysis carried out by our lab revealed robust upregulation of the PERK pathways members Activating Transcription Factor (ATF) 3 and stanniocalcin (STC) 2. The roles of ATF3 and STC2 within the context of PERK signaling and pancreatitis are not well known. Thus, the goal of this study was to define the roles of STC2 and ATF3 during pancreatitis. Gene expression analysis revealed significant increases in STC2 during cerulein induced pancreatitis (CIP) and mice overexpressing STC2 (STC2Tg) exhibited decreased pancreatitis severity as evidenced by the maintenance of acinar cell differentiation markers, lower levels of serum amylase compared to wild type (WT) and a decreased necrosis to apoptosis ratio. Conversely, ATF3 appears to function in an opposite fashion to STC2 during pancreatitis. Chromatin immunoprecipitation (ChIP) of pancreatic tissue following CIP showed that ATF3 bound the Mist1 promoter, recruited Histone Deacteylasee (HDAC) 5 and repressed Mist1 expression, leading to loss of the acinar cell phenotype. Human and mouse pancreatitis tissue samples reveal mutually exclusive expression of ATF3 and MIST1, illustrating clinical relevance for ATF3. Mice lacking Atf3 (Atf3-/-) exhibited a similar phenotype to STC2Tg mice, with increased maintenance of cellular junctions and cell polarity. These findings suggest that these mediators of the PERK pathway lead to opposing outcomes, and that this pathway plays a dual role of both protection and injury during pancreatitis

Role Occupancy, Physical Health and the Diminishment of the Sense of Mattering in Late Life

Mattering is an important but understudied part of the self-concept. Morris Rosenberg and Claire McCullough (1981) suggested that older adults feel they matter less than middle-aged adults and this discrepancy may in part be explained by a lack of role occupancies such as paid work, and a devaluation of the old in society at large. This dissertation examines sense of mattering in older adults and two mechanisms that may explain the decline of the self-concept in later life - fewer role occupancies and poorer physical health. It examines whether these processes differ for men versus women and for African-Americans versus whites. The study employs the first wave (2001) of data from the Aging, Stress and Health (ASH) Study, which includes over 1100 white and African-American adults over age 65 living in the Washington, D.C. metropolitan area. Results indicate that there is a negative relationship between age and both dependence mattering and importance mattering and that it is in part explained by role occupancies as well as physical health status. Compared to informal ties, work and volunteer roles (productive or formal roles), are more important in explaining the relationship between age and mattering. Additionally, the total number of roles held is significantly and positively related to dependence and importance mattering. How roles mediate the relationship between age and dependence mattering depends on race and gender. The work role significantly mediates the age/mattering relationship for whites, but not for African-Americans. For African-Americans, the volunteer role mediates the relationship between age and dependence mattering, but this is not the case for whites. Also, self-rated health mediates the age-dependence mattering relationship for whites but not African-Americans. These findings point to the need to employ multiple mattering measures in analyses of older adults as well to study diverse samples; results differ depending on the outcome variable and group examined. Mattering is critical to the comprehensive study of the self-concept in later phases of the life course, as it is sensitive to social roles and physical health both of which are locations for key changes occurring during late life

La “vida secreta” del Estado de Flujo de Efectivo: un análisis bibliométrico

[EN] The International Financial Reporting Standard Foundation issued a new Conceptual Framework for Financial Reporting. According to this document, the general purpose of financial reporting is to provide financial information about the reporting entity which is useful to existing and potential investors, lenders and other creditors in making decisions related to raise resources for the entity. Focused on the Statement of Cash Flow analysis the main objective of this paper is to provide an overview about how academic researchers have evolved about the usefulness of this Statement. Firstly, we sought to find the best database to perform a bibliometric analysis on the sample identified about the Statement of Cash Flow research. Secondly, we analysed the different stages of the research trends and the main topics. As interesting results of the analysis we can highlight that the clusters in the bibliographic network match with the research lines identified and connections between the papers have been increasing further through networks. The research lines mentioned by the accounting regulators, who issued the cash flow standards, have mostly concluded that the Statement of Cash Flow is useful to fulfill those purposes together with the researchers.[ES] La Fundación Internacional de Normas de Información Financiera emitió un nuevo Marco Conceptual para la Información Financiera. Según este documento, el objetivo general de la información financiera es proporcionar información financiera sobre la entidad informante que sea útil para los inversores existentes y potenciales, los prestamistas y otros acreedores en la toma de decisiones relacionadas con la obtención de recursos para la entidad. Centrado en el análisis del Estado de Flujo de Efectivo, el objetivo principal de este trabajo es proporcionar una visión general sobre la evolución de los investigadores académicos acerca de la utilidad de este estado financiero. En primer lugar, se buscó la mejor base de datos para realizar un análisis bibliométrico sobre la muestra identificada respecto a la investigación del Estado de Flujo de Efectivo. En segundo lugar, se analizaron las diferentes etapas de las tendencias de investigación y los principales temas sobre el tema. Como resultados interesantes del análisis se destaca que los clusters de la red bibliográfica coinciden con las líneas de investigación identificadas y que las conexiones entre los trabajos han ido aumentando. Las líneas de investigación mencionadas por los reguladores contables, que emitieron las normas de flujo de caja, han concluido en su mayoría que el Estado de Flujo de Efectivo es útil para cumplir esos propósitos

Adiabatic dynamics in a spin-1 chain with uniaxial single-spin anisotropy

We study the adiabatic quantum dynamics of an anisotropic spin-1 XY chain across a second order quantum phase transition. The system is driven out of equilibrium by performing a quench on the uniaxial single-spin anisotropy, that is supposed to vary linearly in time. We show that, for sufficiently large system sizes, the excess energy after the quench admits a non trivial scaling behavior that is not predictable by standard Kibble-Zurek arguments for isolated critical points or extended critical regions. This emerges from a competing effect of many accessible low-lying excited states, inside the whole continuous line of critical points.Comment: 17 pages, 8 figures, published versio

Stanniocalcin 2 alters PERK signalling and reduces cellular injury during cerulein induced pancreatitis in mice

BACKGROUND: Stanniocalcin 2 (STC2) is a secreted protein activated by (PKR)-like Endoplasmic Reticulum Kinase (PERK) signalling under conditions of ER stress in vitro. Over-expression of STC2 in mice leads to a growth-restricted phenotype; however, the physiological function for STC2 has remained elusive. Given the relationship of STC2 to PERK signalling, the objective of this study was to examine the role of STC2 in PERK signalling in vivo. RESULTS: Since PERK signalling has both physiological and pathological roles in the pancreas, STC2 expression was assessed in mouse pancreata before and after induction of injury using a cerulein-induced pancreatitis (CIP) model. Increased Stc2 expression was identified within four hours of initiating pancreatic injury and correlated to increased activation of PERK signalling. To determine the effect of STC2 over-expression on PERK, mice systemically expressing human STC2 (STC2Tg) were examined. STC2Tg pancreatic tissue exhibited normal pancreatic morphology, but altered activation of PERK signalling, including increases in Activating Transcription Factor (ATF) 4 accumulation and autophagy. Upon induction of pancreatic injury, STC2Tg mice exhibited limited increases in circulating amylase levels and increased maintenance of cellular junctions. CONCLUSIONS: This study links STC2 to the pathological activation of PERK in vivo, and suggests involvement of STC2 in responding to pancreatic acinar cell injury

Dietary geraniol by oral or enema administration strongly reduces dysbiosis and systemic inflammation in dextran sulfate sodium-treated mice

(Trans)-3,7-Dimethyl-2,6-octadien-1-ol, commonly called geraniol (Ge-OH), is an acyclic monoterpene alcohol with well-known anti-inflammatory, antitumoral, and antimicrobial properties. It is widely used as a preservative in the food industry and as an antimicrobial agent in animal farming. The present study investigated the role of Ge-OH as an anti-inflammatory and anti-dysbiotic agent in the dextran sulfate sodium (DSS)-induced colitis mouse model. Ge-OH was orally administered to C57BL/6 mice at daily doses of 30 and 120 mg kg(-1) body weight, starting 6 days before DSS treatment and ending the day after DSS removal. Furthermore, Ge-OH 120 mg kg(-1) dose body weight was administered via enema during the acute phase of colitis to facilitate its on-site action. The results show that orally or enema-administered Ge-OH is a powerful antimicrobial agent able to prevent colitis-associated dysbiosis and decrease the inflammatory systemic profile of colitic mice. As a whole, Ge-OH strongly improved the clinical signs of colitis and significantly reduced cyclooxygenase-2 (COX-2) expression in colonocytes and in the gut wall. Ge-OH could be a powerful drug for the treatment of intestinal inflammation and dysbiosis

Many-body localization and thermalization in the full probability distribution function of observables

We investigate the relation between thermalization following a quantum quench and many-body localization in quasiparticle space in terms of the long-time full distribution function of physical observables. In particular, expanding on our recent work [E. Canovi {\em et al.}, Phys. Rev. B {\bf 83}, 094431 (2011)], we focus on the long-time behavior of an integrable XXZ chain subject to an integrability-breaking perturbation. After a characterization of the breaking of integrability and the associated localization/delocalization transition using the level spacing statistics and the properties of the eigenstates, we study the effect of integrability-breaking on the asymptotic state after a quantum quench of the anisotropy parameter, looking at the behavior of the full probability distribution of the transverse and longitudinal magnetization of a subsystem. We compare the resulting distributions with those obtained in equilibrium at an effective temperature set by the initial energy. We find that, while the long time distribution functions appear to always agree {\it qualitatively} with the equilibrium ones, {\it quantitative} agreement is obtained only when integrability is fully broken and the relevant eigenstates are diffusive in quasi-particle space.Comment: 18 pages, 11 figure

Atoh1 \u3csup\u3e+\u3c/sup\u3e secretory progenitors possess renewal capacity independent of Lgr5 \u3csup\u3e+\u3c/sup\u3e cells during colonic regeneration

During homeostasis, the colonic epithelium is replenished every 3–5 days by rapidly cycling Lgr5 + stem cells. However, various insults can lead to depletion of Lgr5 + stem cells, and colonic epithelium can be regenerated from Lgr5-negative cells. While studies in the small intestine have addressed the lineage identity of the Lgr5-negative regenerative cell population, in the colon this question has remained unanswered. Here, we set out to identify which cell(s) contribute to colonic regeneration by performing genetic fate-mapping studies of progenitor populations in mice. First, using keratin-19 (Krt19) to mark a heterogeneous population of cells, we found that Lgr5-negative cells can regenerate colonic crypts and give rise to Lgr5 + stem cells. Notch1 + absorptive progenitor cells did not contribute to epithelial repair after injury, whereas Atoh1 + secretory progenitors did contribute to this process. Additionally, while colonic Atoh1 + cells contributed minimally to other lineages during homeostasis, they displayed plasticity and contributed to epithelial repair during injury, independent of Lgr5 + cells. Our findings suggest that promotion of secretory progenitor plasticity could enable gut healing in colitis

Intact LKB1 activity is required for survival of dormant ovarian cancer spheroids

Metastatic epithelial ovarian cancer (EOC) cells can form multicellular spheroids while in suspension and disperse directly throughout the peritoneum to seed secondary lesions. There is growing evidence that EOC spheroids are key mediators of metastasis, and they use specific intracellular signalling pathways to control cancer cell growth and metabolism for increased survival. Our laboratory discovered that AKT signalling is reduced during spheroid formation leading to cellular quiescence and autophagy, and these may be defining features of tumour cell dormancy. To further define the phenotype of EOC spheroids, we have initiated studies of the Liver kinase B1 (LKB1)-5′-AMP-activated protein kinase (AMPK) pathway as a master controller of the metabolic stress response. We demonstrate that activity of AMPK and its upstream kinase LKB1 are increased in quiescent EOC spheroids as compared with proliferating adherent EOC cells. We also show elevated AMPK activity in spheroids isolated directly from patient ascites. Functional studies reveal that treatment with the AMP mimetic AICAR or allosteric AMPK activator A-769662 led to a cytostatic response in proliferative adherent ovarian cancer cells, but they fail to elicit an effect in spheroids. Targeted knockdown of STK11 by RNAi to reduce LKB1 expression led to reduced viability and increased sensitivity to carboplatin treatment in spheroids only, a phenomenon which was AMPK-independent. Thus, our results demonstrate a direct impact of altered LKB1-AMPK signalling function in EOC. In addition, this is the first evidence in cancer cells demonstrating a pro-survival function for LKB1, a kinase traditionally thought to act as a tumour suppressor

Combination of AKT inhibition with autophagy blockade effectively reduces ascites-derived ovarian cancer cell viability

Recent genomics analysis of the high-grade serous subtype of epithelial ovarian cancer (EOC) show aberrations in the phosphatidylinositol 3-kinase (PI3K)/AKT pathway that result in upregulated signaling activity. Thus, the PI3K/AKT pathway represents a potential therapeutic target for aggressive high-grade EOC. We previously demonstrated that treatment of malignant ascites-derived primary human EOC cells and ovarian cancer cell lines with the allosteric AKT inhibitor Akti-1/2 induces a dormancy-like cytostatic response but does not reduce cell viability. In this report, we show that allosteric AKT inhibition in these cells induces cytoprotective autophagy. Inhibition of autophagy using chloroquine (CQ) alone or in combination with Akti-1/2 leads to a significant decrease in viable cell number. In fact, Akti-1/2 sensitizes EOC cells to CQ-induced cell death by exhibiting markedly reduced EC50 values in combination-treated cells compared with CQ alone. In addition, we evaluated the effects of the novel specific and potent autophagy inhibitor-1 (Spautin-1) and demonstrate that Spautin-1 inhibits autophagy in a Beclin-1-independent manner in primary EOC cells and cell lines. Multicellular EOC spheroids are highly sensitive to Akti-1/2 and CQ/Spautin-1 cotreatments, but resistant to each agent alone. Indeed, combination index analysis revealed strong synergy between Akti-1/2 and Spautin-1 when both agents were used to affect cell viability; Akti-1/2 and CQ cotreatment also displayed synergy in most samples. Taken together, we propose that combination AKT inhibition and autophagy blockade would prove efficacious to reduce residual EOC cells for supplying ovarian cancer recurrence. © The Author 2014. Published by Oxford University Press. All rights reserved