From the extracellular matrix to the microprocessor: Investigating the post-transcriptional regulation of miRNA-155 by tenascin-C

A highly controlled type of short RNA sequences called microRNAs (miRNAs) regulates cellular processes via translational repression or degradation of target mRNAs. In particular, miRNA-155 plays a central role in the macrophage inflammatory response to infection, with dysregulation of miR-155 associated with pathological inflammation. Previous work in the Piccinini lab has identified a post-transcriptional mechanism of miR-155 regulation, showing that the extracellular matrix (ECM) glycoprotein tenascin-C (TN-C) regulates processing of the miR-155 transcript (pri-miR155) in lipopolysaccharide (LPS)-stimulated bone marrow-derived macrophages (BMDMs). However, how this regulation occurs is yet to be elucidated. This project aimed to identify by what mechanism TN-C regulates miR-155 processing in activated macrophages, involving examination of candidate TNC receptors, intracellular signalling pathways associated with both TN-C and miR-155 biogenesis machinery, as well as identification of pri-miRNA features associated with TN-Cs regulatory activity. Utilising gain and loss-of-function approaches, examination of the candidate yes-associated protein (YAP) pathway, an increasingly relevant pathway in the study of cancer and inflammation, showed no association between this pathway and the post-transcriptional regulation of miR-155 by TN-C. Remarkably, however, for the first time ectopic expression of YAP was found to negatively regulate macrophage miR-155 transcription, this being linked to inhibition of the critical pro-inflammatory transcription factor NF-κB. Additionally, knockdown of TN-C expression in steady-state RAW 246.7 macrophages found TN-C to regulate p38α and MK2, a master regulator of RNA-binding proteins, total protein abundance, but not their phosphorylation, this being attributed to an increase in p38α mRNA levels as a result of TN-C knockdown, occurring via an unknown mechanism. Furthermore, siRNA-based knockdown analysis of candidate TN-C receptors pointed to integrin αV as potential transducer of TN-C signalling the regulation of miR-155 expression. Finally, interrogation of RNA-SEQ data from LPS treated TNC knockout and wild type BMDMs found no significant association between specific pri-miRNAs cis-regulatory elements, known to facilitate miRNA processing, and miRNAs modulated by TN-C in a similar manner as miR-155. Interestingly, TNC knockout was found to associate with a significant decline in 5p strand mature miRNA, with a concurrent induction in the levels of the 3p strand, potential evidence of TN-C orchestrating a miRNA arm-switching event. Overall, whilst this project rules out YAP and MK2 as molecular players in the TN-C-miR-155 pathway, it unveils two new research directions: YAP as potential regulator of miR-155 transcription independent of TN-C and, excitingly, TN-C as a potential regulator of cell-wide miRNA strand selection

A Consideration of Methods of Securing Historical Price and Production Data and a Survey of Their Relationship for South Dakota

In our studies of prices we will analyze the present prices; discuss the use of price date now available and consider methods of collecting further data. As South Dakota is one of several states or countries producing a surplus of crops and livestock for market, production for the United States and for the world, of certain products, must be considered as affecting the farm prices in South Dakota

Eastern Presence: Metropolitan responses to the Indian Army, 1914-15

The mobilisation of the British empire during the First World War created new spaces for encounter between British and Indian society. Between August 1914 and December 1915, the Indian army dispatched over 100,000 Indian servicemen to the Western Front as part of Indian Expeditionary Force A. The thesis’s objective is to improve understanding of how Western and, more specifically, British society responded to the presence of these Indian servicemen. It reconsiders British perspectives of the Indian solider, reflects upon how these perspectives impacted the discourse which surrounded the sepoys, and the effect it had on the Indian army’s colonial hierarchy. As a result, ‘Eastern Presence’ furthers understanding of British conceptions of racial identity and colonialism within the context of the First World War and demonstrates the impact that these conceptions had on the Indian army’s hierarchical structure. To achieve this goal, the thesis uses the geographical and locational settings experienced by Indian servicemen during their stay in Western Europe to analyse their interactions with various parts of British and Western society. Through its analysis of these interactions, ‘Eastern Presence’ challenges much of the existing historiography by arguing that variances in conceptions of race can be identified, depending on the part of British society which experienced the encounter. It consequently concludes that British society demonstrated varying degrees of knowledge, empathy, and perception towards the colonial ‘other’ in its midst

From the extracellular matrix to the microprocessor: Investigating the post-transcriptional regulation of miRNA-155 by tenascin-C

A highly controlled type of short RNA sequences called microRNAs (miRNAs) regulates cellular processes via translational repression or degradation of target mRNAs. In particular, miRNA-155 plays a central role in the macrophage inflammatory response to infection, with dysregulation of miR-155 associated with pathological inflammation. Previous work in the Piccinini lab has identified a post-transcriptional mechanism of miR-155 regulation, showing that the extracellular matrix (ECM) glycoprotein tenascin-C (TN-C) regulates processing of the miR-155 transcript (pri-miR155) in lipopolysaccharide (LPS)-stimulated bone marrow-derived macrophages (BMDMs). However, how this regulation occurs is yet to be elucidated. This project aimed to identify by what mechanism TN-C regulates miR-155 processing in activated macrophages, involving examination of candidate TNC receptors, intracellular signalling pathways associated with both TN-C and miR-155 biogenesis machinery, as well as identification of pri-miRNA features associated with TN-Cs regulatory activity. Utilising gain and loss-of-function approaches, examination of the candidate yes-associated protein (YAP) pathway, an increasingly relevant pathway in the study of cancer and inflammation, showed no association between this pathway and the post-transcriptional regulation of miR-155 by TN-C. Remarkably, however, for the first time ectopic expression of YAP was found to negatively regulate macrophage miR-155 transcription, this being linked to inhibition of the critical pro-inflammatory transcription factor NF-κB. Additionally, knockdown of TN-C expression in steady-state RAW 246.7 macrophages found TN-C to regulate p38α and MK2, a master regulator of RNA-binding proteins, total protein abundance, but not their phosphorylation, this being attributed to an increase in p38α mRNA levels as a result of TN-C knockdown, occurring via an unknown mechanism. Furthermore, siRNA-based knockdown analysis of candidate TN-C receptors pointed to integrin αV as potential transducer of TN-C signalling the regulation of miR-155 expression. Finally, interrogation of RNA-SEQ data from LPS treated TNC knockout and wild type BMDMs found no significant association between specific pri-miRNAs cis-regulatory elements, known to facilitate miRNA processing, and miRNAs modulated by TN-C in a similar manner as miR-155. Interestingly, TNC knockout was found to associate with a significant decline in 5p strand mature miRNA, with a concurrent induction in the levels of the 3p strand, potential evidence of TN-C orchestrating a miRNA arm-switching event. Overall, whilst this project rules out YAP and MK2 as molecular players in the TN-C-miR-155 pathway, it unveils two new research directions: YAP as potential regulator of miR-155 transcription independent of TN-C and, excitingly, TN-C as a potential regulator of cell-wide miRNA strand selection

miR-155-3p: processing by-product or rising star in immunity and cancer?

MicroRNAs (miRNAs) are key players in gene regulation that target specific mRNAs for degradation or translational repression. Each miRNA is synthesized as a miRNA duplex comprising two strands (5p and 3p). However, only one of the two strands becomes active and is selectively incorporated into the RNA-induced silencing complex in a process known as miRNA strand selection. Recently, significant progress has been made in understanding the factors and processes involved in strand selection. Here, we explore the selection and functionality of the miRNA star strand (either 5p or 3p), which is generally present in the cell at low levels compared to its partner strand and, historically, has been thought to possess no biological activity. We also highlight the concepts of miRNA arm switching and miRNA isomerism. Finally, we offer insights into the impact of aberrant strand selection on immunity and cancer. Leading us through this journey is miR-155, a well-established regulator of immunity and cancer, and the increasing evidence that its 3p strand plays a role in these arenas. Interestingly, the miR-155-5p/-3p ratio appears to vary dependent on the timing of the immune response, and the 3p strand seems to play a regulatory role upon its partner 5p strand

La multiplication de matériel de plantation de qualité pour améliorer l'état sanitaire et la productivité des cultures : pratiques clefs pour les bananiers et les bananiers plantain. Guide illustré

Available in English, French, Spanish and Arabic, on line and on CD-ROM, this illustrated guide summarizes the key practices for producing clean planting material of banana with a high yield potential for smallholders, depending on the pests and diseases which are present. The guide is also designed to contribute to better planning of the propagation of planting material for rural development and disaster relief projects. (Résumé d'auteur

Measurements of Scintillation Efficiency and Pulse-Shape for Low Energy Recoils in Liquid Xenon

Results of observations of low energy nuclear and electron recoil events in liquid xenon scintillator detectors are given. The relative scintillation efficiency for nuclear recoils is 0.22 +/- 0.01 in the recoil energy range 40 keV - 70 keV. Under the assumption of a single dominant decay component to the scintillation pulse-shape the log-normal mean parameter T0 of the maximum likelihood estimator of the decay time constant for 6 keV < Eee < 30 keV nuclear recoil events is equal to 21.0 ns +/- 0.5 ns. It is observed that for electron recoils T0 rises slowly with energy, having a value ~ 30 ns at Eee ~ 15 keV. Electron and nuclear recoil pulse-shapes are found to be well fitted by single exponential functions although some evidence is found for a double exponential form for the nuclear recoil pulse-shape.Comment: 11 pages, including 5 encapsulated postscript figure