microRNA Regulation of Cellular Immunity

Immunity is broadly defined as a mechanism of protection against non-self entities, a process which must be sufficiently robust to both eliminate the initial foreign body and then be maintained over the life of the host. Life-long immunity is impossible without the development of immunological memory, of which a central component is the cellular immune system, or T cells. Cellular immunity hinges upon a naïve T cell pool of sufficient size and breadth to enable Darwinian selection of clones responsive to foreign antigens during an initial encounter. Further, the generation and maintenance of memory T cells is required for rapid clearance responses against repeated insult, and so this small memory pool must be actively maintained by pro-survival cytokine signals over the life of the host.

T cell development, function, and maintenance are regulated on a number of molecular levels through complex regulatory networks. Recently, small non-coding RNAs, miRNAs, have been observed to have profound impacts on diverse aspects of T cell biology by impeding the translation of RNA transcripts to protein. While many miRNAs have been described that alter T cell development or functional differentiation, little is known regarding the role that miRNAs have in T cell maintenance in the periphery at homeostasis.

In Chapter 3 of this dissertation, tools to study miRNA biology and function were developed. First, to understand the effect that miRNA overexpression had on T cell responses, a novel overexpression system was developed to enhance the processing efficiency and ultimate expression of a given miRNA by placing it within an alternative miRNA backbone. Next, a conditional knockout mouse system was devised to specifically delete miR-191 in a cell population expressing recombinase. This strategy was expanded to permit the selective deletion of single miRNAs from within a cluster to discern the effects of specific miRNAs that were previously inaccessible in isolation. Last, to enable the identification of potentially therapeutically viable miRNA function and/or expression modulators, a high-throughput flow cytometry-based screening system utilizing miRNA activity reporters was tested and validated. Thus, several novel and useful tools were developed to assist in the studies described in Chapter 4 and in future miRNA studies.

In Chapter 4 of this dissertation, the role of miR-191 in T cell biology was evaluated. Using tools developed in Chapter 3, miR-191 was observed to be critical for T cell survival following activation-induced cell death, while proliferation was unaffected by alterations in miR-191 expression. Loss of miR-191 led to significant decreases in the numbers of CD4+ and CD8+ T cells in the periphery lymph nodes, but this loss had no impact on the homeostatic activation of either CD4+ or CD8+ cells. These peripheral changes were not caused by gross defects in thymic development, but rather impaired STAT5 phosphorylation downstream of pro-survival cytokine signals. miR-191 does not specifically inhibit STAT5, but rather directly targets the scaffolding protein, IRS1, which in turn alters cytokine-dependent signaling. The defect in peripheral T cell maintenance was exacerbated by the presence of a Bcl-2YFP transgene, which led to even greater peripheral T cell losses in addition to developmental defects. These studies collectively demonstrate that miR-191 controls peripheral T cell maintenance by modulating homeostatic cytokine signaling through the regulation of IRS1 expression and downstream STAT5 phosphorylation.

The studies described in this dissertation collectively demonstrate that miR-191 has a profound role in the maintenance of T cells at homeostasis in the periphery. Importantly, the manipulation of miR-191 altered immune homeostasis without leading to severe immunodeficiency or autoimmunity. As much data exists on the causative agents disrupting active immune responses and the formation of immunological memory, the basic processes underlying the continued maintenance of a functioning immune system must be fully characterized to facilitate the development of methods for promoting healthy immune function throughout the life of the individual. These findings also have powerful implications for the ability of patients with modest perturbations in T cell homeostasis to effectively fight disease and respond to vaccination and may provide valuable targets for therapeutic intervention.

New Narratives of International Security Governance: The Shift from Global Interventionism to Global Self-Policing

This article examines the transformation in the narratives of the international governance of security over the last two decades. It suggests that there has been a major shift from governing interventions designed to address the causes of security problems to the regulation of the effects of these problems. In rearticulating the goals of international actors, the means and mechanisms of security governance have also changed, no longer focused on the universal application of Western knowledge and resources but rather on the unique local and organic processes at work in societies that bear the brunt of these problems. This transformation takes the conceptualisation of security governance out of the traditional terminological lexicon of security expertise and universal solutions and instead articulates the problematic of security and the policing of global risks in terms of local management processes, suggesting that decentralised coping strategies and self-policing are more effective and sustainable solutions.

De Relatie tussen Angst- en Stemmingsklachten en Self-disclosure: het Effect van Emotie-inhibitie en Mindfulness

Angst- en stemmingsklachten worden geassocieerd met verminderde self-disclosure. Met self-disclosure wordt zelfonthulling van ervaren emoties bedoeld. Dit speelt een rol bij zelfacceptatie en zelfinzicht, en is belangrijk bij gesprekstherapie. Deze studie onderzocht of emotie-inhibitie de negatieve relatie tussen angst- en stemmingsklachten en self-diclosure verklaart, en of de relatie gunstig te beïnvloeden is door mindfulness. Het effect van mindfulness op deze relatie was nog niet eerder onderzocht. Deelnemers waren 99 vrouwen van 24 t/m 74 jaar (M = 44.60, SD = 10.55) en 26 mannen van 26 t/m 77 jaar (M = 48.27, SD = 12.68), afkomstig uit de normale Nederlands populatie. Het onderzoeksontwerp betrof een cross-sectioneel online vragenlijstonderzoek, waarbij gebruik gemaakt werd van de Symptom Checklist (Arrindel & Ettema, 1986), Emotional Self-Disclosure Scale (Snell, Miller, & Belk, 1988), Emotion Regulation Questionnaire (Gross & John, 2003) en Five Factor Mindfulness Questionnaire – Short Form (Bohlmeijer, Ten Klooster, Fledderus, Veehof, & Baer, 2011). Resultaten tonen, conform bestaande literatuur, dat angst- en stemmingsklachten negatief samenhangen met self-disclosure. Emotie-inhibitie heeft echter géén mediatie-effect en mindfulness heeft géén moderatie-effect op de negatieve relatie tussen angst- en stemmingsklachten en self-disclosure. Mindfulness heeft wel mediatie-effect op deze relatie. Mindfulness hangt hierbij positief samen met self-disclosure. De relevantie van de bevindingen is vooral praktisch: om mensen met angst- en stemmingsklachten te stimuleren over hun emoties te praten zou mindfulness aangewend kunnen worden.

The Legal, Medical and Cultural Regulation of the Body: Transformation and Transgression

The regulation of the body provides an important concern in law, medical practice and culture. This volume contributes to existing research in the area by encouraging experts from a range of related disciplines to consider the legal, cultural and medical ways in which we regulate the body, further exploring how conceptions of self, liberalism, property and harm inform and influence contentious legal and ethical questions about what we can and cannot do to or with our own bodies.

Do Individual Differences in Emotion Regulation Mediate the Relationship Between Mental Toughness and Symptoms of Depression?

Mental Toughness (MT) provides crucial psychological capacities for achievement in sports,
education, and work settings. Previous research examined the role of MT in the domain of
mental health and showed that MT is negatively associated with and predictive of fewer
depressive symptoms in non-clinical populations. The present study aimed at 1) investigating
to what extent mentally tough individuals use two emotion regulation strategies: cognitive
reappraisal and expressive suppression; 2) exploring whether individual differences in
emotion regulation strategy use mediate the relationship between MT and depressive
symptoms. Three hundred sixty-four participants (M = 24.31 years, SD = 9.16) provided
self-reports of their levels of MT, depressive symptoms, and their habitual use of cognitive
reappraisal and expressive suppression. The results showed a statistically significant
correlation between MT and two commonly used measures of depressive symptoms. A small
statistically significant positive correlation between MT and the habitual use of cognitive
reappraisal was also observed. The correlation between MT and the habitual use of
expressive suppression was statistically significant, but the size of the effect was small. A
statistical mediation model indicated that individual differences in the habitual use of
expressive suppression mediate the relationship between MT and depressive symptoms. No
such effect was found for the habitual use of cognitive reappraisal. Implications of these
findings and possible avenues for future research are discussed.

Barriers of sentiment : Identity -formation, -regulation and subjectification in preschools

This thesis studies preschool socialization in terms of identity -formation, -regulation, and subjectification. Both the methodology and theoretical backdrop draws on Critical Management Studies, and the contribution to research comes from studying a subject otherwise non-prioritized. I have performed a qualitative study entailing interviews of pedagogues and preschool chiefs working within the same company in the Stockholm region. The study indicate that preschool discourse emphasize the importance of social competences and rituals, and moreover that the institution also accentuates its role in setting the proper ‘preconditions’. Furthermore, the study demonstrates how pedagogues – using mechanisms such as individual discourses, the children’s agency, and the milieu – try to form individuals who are: social, independent, self-reliant, have a strong ‘self’, joyful towards learning, and ‘can do it themselves’. I make a liaison between the aforementioned ideals and certain trends discussed by managerial literature, like for instance currents towards: self-management, neo-normative control, self-entrepreneurial attitudes, ambidextrousness, and the ‘principle of potential’ (Costea et al., 2012; Fleming & Study, 2009; Holmqvist & Spicer, 2013; Maravelias, 2011; Pongratz & Voß, 2003). Finally the thesis concludes by firstly underscoring that the Discourse of for example ‘joyful learning’ and ‘independency’ in preschools tend to demolish physical modes of control in place of psychological ones; and secondly, by discussing historical practices, the thesis brings attention to a shift from safekeeping children to preparing them for industrial, urbanistic, and capitalistic social existence. 

Professionalising positive psychology: Developing guidelines for training and regulation

Although positive psychology (PP) was initially conceived as more a shift in perspective (towards the “positive”) than a new field per se, in pragmatic terms, it is arguably beginning to function as a distinct discipline, with people self-identifying as “positive psychologists.” Thus, we contend it is time for the field to start developing a system of professional (e.g., ethical) guidelines to inform the practice of PP. To this end, we outline one such possible system, drawing on guidelines in counselling and psychotherapy. Moreover, we argue for the creation of two tiers of professional identity within PP. Firstly, people with a master’s qualification in PP might label themselves “positive psychology practitioners.” Secondly, we raise the possibility of creating a professional doctorate in PP which would enable graduates to assume the title of “positive psychologist.” We hope that this paper will contribute towards a dialogue within the field around these issues, helping PP to develop further over the years ahead.

Functional Neuroimaging of the Social Regulation of Emotion in Schizophrenia

Negative symptoms in schizophrenia are characterized by deficits in normative experiences and expression of emotion. Social anhedonia (diminished pleasure from social experiences) is one negative symptom that may impact patients’ motivation to engage in meaningful social relationships. Past research has begun to examine the mechanisms that underlie social anhedonia, but it is unclear how this lack of social interest may impact the typically positive effects of social buffering and social baseline theory whereby social support attenuates stress. The present pilot study examines how social affiliation through hand holding is related to subjective and neural threat processing, negative symptoms, and social functioning. Twenty-one participants (14 controls; 7 schizophrenia) developed social affiliation with a member of the research staff who served as the supportive partner during the threat task. Participants displayed greater subjective benefit to holding the hand of their partner during times of stress relative to being alone or with an anonymous experimenter, as indicated by self-reported increased positive valence and decreased arousal ratings. When examining the effects of group, hand holding, and their interaction on the neurological experience of threat during the fMRI task, the results were not significant. However, exploratory analyses identified preliminary data suggesting that controls experienced small relative increases in BOLD signal to threat when alone compared to being with the anonymous experimenter or their partner, whereas the schizophrenia group results indicated subtle relative decreases in BOLD signal to threat when alone compared to either of the hand holding conditions. Additionally, within the schizophrenia group, more positive valence in the partner condition was associated with less severe negative symptoms, better social functioning, and more social affiliation, whereas less arousal was correlated with more social affiliation. Our pilot study offers initial insights about the difficulties of building and using social affiliation and support through hand holding with individuals with schizophrenia during times of stress. Further research is necessary to clarify which types of support may be more or less beneficial to individuals with schizophrenia who may experience social anhedonia or paranoia with others that may challenge the otherwise positive effects of social buffering and maintaining a social baseline.

Synthetic regulation of eukaryotic gene expression by noncoding RNA

Synthetic biological systems promise to combine the spectacular diversity of biological functionality with engineering principles to design new life to address many pressing needs. As these engineered systems advance in sophistication, there is ever-greater need for customizable, situation-specific expression of desired genes. However, existing gene control platforms are generally not modular, or do not display performance requirements required for robust phenotypic responses to input signals. This work expands the capabilities of eukaryotic gene control in two important directions.

For development of greater modularity, we extend the use of synthetic self-cleaving ribozyme switches to detect changes in input protein levels and convey that information into programmed gene expression in eukaryotic cells. We demonstrate both up- and down-regulation of levels of an output transgene by more than 4-fold in response to rising input protein levels, with maximal output gene expression approaching the highest levels observed in yeast. In vitro experiments demonstrate protein-dependent ribozyme activity modulation. We further demonstrate the platform in mammalian cells. Our switch devices do not depend on special input protein activity, and can be tailored to respond to any input protein to which a suitable RNA aptamer can be developed. This platform can potentially be employed to regulate the expression of any transgene or any endogenous gene by 3’ UTR replacement, allowing for more complex cell state-specific reprogramming.

We also address an important concern with ribozyme switches, and riboswitch performance in general, their dynamic range. While riboswitches have generally allowed for versatile and modular regulation, so far their dynamic ranges of output gene modulation have been modest, generally at most 10-fold. We address this shortcoming by developing a modular genetic amplifier for near-digital control of eukaryotic gene expression. We combine ribozyme switch-mediated regulation of a synthetic TF with TF-mediated regulation of an output gene. The amplifier platform allows for as much as 20-fold regulation of output gene expression in response to input signal, with maximal expression approaching the highest levels observed in yeast, yet being tunable to intermediate and lower expression levels. EC50 values are more than 4 times lower than in previously best-performing non-amplifier ribozyme switches. The system design retains the modular-input architecture of the ribozyme switch platform, and the near-digital dynamic ranges of TF-based gene control.

Together, these developments suggest great potential for the wide applicability of these platforms for better-performing eukaryotic gene regulation, and more sophisticated, customizable reprogramming of cellular activity.

THE INFLUENCE OF MOTIVATION ON EMOTION REGULATION AND MOTOR PERFORMANCE: EXAMINATION OF A NEURO-AFFECTIVE MODEL

Mental stress is known to disrupt the execution of motor performance and can lead to decrements in the quality of performance, however, individuals have shown significant differences regarding how fast and well they can perform a skilled task according to how well they can manage stress and emotion. The purpose of this study was to advance our understanding of how the brain modulates emotional reactivity under different motivational states to achieve differential performance in a target shooting task that requires precision visuomotor coordination. In order to study the interactions in emotion regulatory brain areas (i.e. the ventral striatum, amygdala, prefrontal cortex) and the autonomic nervous system, reward and punishment interventions were employed and the resulting behavioral and physiological responses contrasted to observe the changes in shooting performance (i.e. shooting accuracy and stability of aim) and neuro-cognitive processes (i.e. cognitive load and reserve) during the shooting task. Thirty-five participants, aged 18 to 38 years, from the Reserve Officers’ Training Corp (ROTC) at the University of Maryland were recruited to take 30 shots at a bullseye target in three different experimental conditions. In the reward condition, $1 was added to their total balance for every 10-point shot. In the punishment condition, $1 was deducted from their total balance if they did not hit the 10-point area. In the neutral condition, no money was added or deducted from their total balance. When in the reward condition, which was reportedly most enjoyable and least stressful of the conditions, heart rate variability was found to be positively related to shooting scores, inversely related to variability in shooting performance and positively related to alpha power (i.e. less activation) in the left temporal region. In the punishment (and most stressful) condition, an increase in sympathetic response (i.e. increased LF/HF ratio) was positively related to jerking movements as well as variability of placement (on the target) in the shots taken. This, coupled with error monitoring activity in the anterior cingulate cortex, suggests evaluation of self-efficacy might be driving arousal regulation, thus affecting shooting performance. Better performers showed variable, increasing high-alpha power in the temporal region during the aiming period towards taking the shot which could indicate an adaptive strategy of engagement. They also showed lower coherence during hit shots than missed shots which was coupled with reduced jerking movements and better precision and accuracy. Frontal asymmetry measures revealed possible influence of the prefrontal lobe in driving this effect in reward and neutral conditions. The possible interactions, reasons behind these findings and implications are discussed.

Up-regulation Of Dnam-1 And Nkp30, Associated With Improvement Of Nk Cells Activation After Long-term Culture Of Mononuclear Cells From Patients With Ovarian Neoplasia.

This study aimed at evaluating the functional activation and activating receptors expression on resting, short- and long-term NK and NK-like T cells from blood of ovarian neoplasia patients. Blood from patients with adnexal benign alterations (n = 10) and ovarian cancer (grade I-IV n = 14) were collected after signed consent. Effector cells activation was evaluated by the expression of the CD107a molecule. Short-term culture was conducted overnight with IL-2 and long-term culture for 21 days, by a method designed to expand CD56(+) lymphocytes. Short-term culture significantly increased NK cells activation compared to resting NK cells (p<0.05), however, the long-term procedure supported an even higher increase (p<0.001). Resting NK-like T cells showed poor activation, which was not altered by the culture procedures. The long-term culture effectively increased the expression of the activating receptors on NK and NK-like T cells, either by increasing the number of cells expressing a given receptor and/or by up-regulating their expression intensity. As a conclusion, the long-term culture system employed, resulted in a high number of functional NK cells. The culture system was particularly efficient on the up-regulation of NKp30 and DNAM-1 receptors on NK cells.

A Microleakage Study Of Gutta-percha/ah Plus And Resilon/real Self-etch Systems After Different Irrigation Protocols.

The development and maintenance of the sealing of the root canal system is the key to the success of root canal treatment. The resin-based adhesive material has the potential to reduce the microleakage of the root canal because of its adhesive properties and penetration into dentinal walls. Moreover, the irrigation protocols may have an influence on the adhesiveness of resin-based sealers to root dentin. The objective of the present study was to evaluate the effect of different irrigant protocols on coronal bacterial microleakage of gutta-percha/AH Plus and Resilon/Real Seal Self-etch systems. One hundred ninety pre-molars were used. The teeth were divided into 18 experimental groups according to the irrigation protocols and filling materials used. The protocols used were: distilled water; sodium hypochlorite (NaOCl)+eDTA; NaOCl+H3PO4; NaOCl+eDTA+chlorhexidine (CHX); NaOCl+H3PO4+CHX; CHX+eDTA; CHX+ H3PO4; CHX+eDTA+CHX and CHX+H3PO4+CHX. Gutta-percha/AH Plus or Resilon/Real Seal Se were used as root-filling materials. The coronal microleakage was evaluated for 90 days against Enterococcus faecalis. Data were statistically analyzed using Kaplan-Meier survival test, Kruskal-Wallis and Mann-Whitney tests. No significant difference was verified in the groups using chlorhexidine or sodium hypochlorite during the chemo-mechanical preparation followed by eDTA or phosphoric acid for smear layer removal. The same results were found for filling materials. However, the statistical analyses revealed that a final flush with 2% chlorhexidine reduced significantly the coronal microleakage. A final flush with 2% chlorhexidine after smear layer removal reduces coronal microleakage of teeth filled with gutta-percha/AH Plus or Resilon/Real Seal SE.

Low-density Three-dimensional Foam Using Self-reinforced Hybrid Two-dimensional Atomic Layers.

Low-density nanostructured foams are often limited in applications due to their low mechanical and thermal stabilities. Here we report an approach of building the structural units of three-dimensional (3D) foams using hybrid two-dimensional (2D) atomic layers made of stacked graphene oxide layers reinforced with conformal hexagonal boron nitride (h-BN) platelets. The ultra-low density (1/400 times density of graphite) 3D porous structures are scalably synthesized using solution processing method. A layered 3D foam structure forms due to presence of h-BN and significant improvements in the mechanical properties are observed for the hybrid foam structures, over a range of temperatures, compared with pristine graphene oxide or reduced graphene oxide foams. It is found that domains of h-BN layers on the graphene oxide framework help to reinforce the 2D structural units, providing the observed improvement in mechanical integrity of the 3D foam structure.

[gait Speed, Grip Strength And Self-rated Health Among The Elderly: Data From The Fibra Campinas Network, São Paulo, Brazil].

The article seeks to investigate patterns of performance and relationships between grip strength, gait speed and self-rated health, and investigate the relationships between them, considering the variables of gender, age and family income. This was conducted in a probabilistic sample of community-dwelling elderly aged 65 and over, members of a population study on frailty. A total of 689 elderly people without cognitive deficit suggestive of dementia underwent tests of gait speed and grip strength. Comparisons between groups were based on low, medium and high speed and strength. Self-related health was assessed using a 5-point scale. The males and the younger elderly individuals scored significantly higher on grip strength and gait speed than the female and oldest did; the richest scored higher than the poorest on grip strength and gait speed; females and men aged over 80 had weaker grip strength and lower gait speed; slow gait speed and low income arose as risk factors for a worse health evaluation. Lower muscular strength affects the self-rated assessment of health because it results in a reduction in functional capacity, especially in the presence of poverty and a lack of compensatory factors.

Ki-1/57 And Cgi-55 Ectopic Expression Impact Cellular Pathways Involved In Proliferation And Stress Response Regulation.

Ki-1/57 (HABP4) and CGI-55 (SERBP1) are regulatory proteins and paralogs with 40.7% amino acid sequence identity and 67.4% similarity. Functionally, they have been implicated in the regulation of gene expression on both the transcriptional and mRNA metabolism levels. A link with tumorigenesis is suggested, since both paralogs show altered expression levels in tumor cells and the Ki-1/57 gene is found in a region of chromosome 9q that represents a haplotype for familiar colon cancer. However, the target genes regulated by Ki-1/57 and CGI-55 are unknown. Here, we analyzed the alterations of the global transcriptome profile after Ki-1/57 or CGI-55 overexpression in HEK293T cells by DNA microchip technology. We were able to identify 363 or 190 down-regulated and 50 or 27 up-regulated genes for Ki-1/57 and CGI-55, respectively, of which 20 were shared between both proteins. Expression levels of selected genes were confirmed by qRT-PCR both after protein overexpression and siRNA knockdown. The majority of the genes with altered expression were associated to proliferation, apoptosis and cell cycle control processes, prompting us to further explore these contexts experimentally. We observed that overexpression of Ki-1/57 or CGI-55 results in reduced cell proliferation, mainly due to a G1 phase arrest, whereas siRNA knockdown of CGI-55 caused an increase in proliferation. In the case of Ki-1/57 overexpression, we found protection from apoptosis after treatment with the ER-stress inducer thapsigargin. Together, our data give important new insights that may help to explain these proteins putative involvement in tumorigenic events.