VictorJuiz/thesis huggingface dataset:
Anesthetic Activation of GABAA Receptors in Astrocytes Triggers a Persistent Increase in the Function of GABAA Receptors in Neurons via IL-1β and p38 MAPK-dependent Pathways
Keywords: Anaesthesia
Astrocytes
Biochemistry
Electrophysiology
GABA

Introduction: Many patients develop perioperative neurocognitive disorders; however, the mechanisms underlying these disorders are poorly understood. Preclinical studies have shown that a brief exposure to a general anesthetic drug can trigger a persistent increase in inhibitory tonic current generated by α5GABAARs in hippocampal neurons. This increase in inhibitory current is associated with sustained postanesthetic cognitive deficits. Astrocytes, which are necessary for this effect, express anesthetic-sensitive GABAARs. However, it is unknown how anesthetic drugs act on astrocytes to trigger the persistent increase in tonic current. Astrocytes release IL-1β, which increases the tonic current in neurons via p38 MAPK-dependent pathways. However, it is also unknown if IL-1β can trigger a persistent change in neuronal GABAAR function via p38 MAPK following anesthetic treatment. Here, we test the hypothesis that anesthetic drugs activate GABAARs in astrocytes, which in turn increases cell-surface expression and function of α5GABAARs in neurons via IL-1β and p38 MAPK-dependent pathways.Methods: Astrocytes and neurons from mice were studied in ex vivo brain slices and in primary cell cultures. Patch clamp and biotinylation studies were used to study the role of GABAAR expressed in astrocytes in the response to anesthetic drugs. The expression profiles of GABAAR subtypes in astrocytes and neurons were studied with ddPCR and Western blotting. The release of IL-1β from astrocytes was evaluated with ELISA and mass spectrometry. IL-1β and p38 MAPK-dependent pathways were evaluated via whole-cell patch clamp recording and Western blot. Results: Inhibiting GABAARs in astrocytes prevented the anesthetic-induced increase in cell-surface expression and function of GABAAR in neurons. Astrocytes express a unique compliment of anesthetic-sensitive GABAARs. The increase of tonic current in neurons was dependent on IL-1β and p38 MAPK function. Conclusions: These results suggest that anesthetic drugs activate GABAARs in astrocytes, which in turn triggers IL-1β and p38 MAPK signaling pathways in neurons. This signaling cascade then causes a persistent increase in α5GABAAR cell-surface expression and function. These results identify a novel crosstalk mechanism between astrocytic GABAARs and neuronal GABAARs that may be targeted to mitigate postanesthetic neurocognitive deficits.
Settler Filipino Kinship Work: Being Better Relations within Turtle Island
Keywords: anti-colonial studies
critical race studies
Filipino studies
Indigenous studies
kinship

This dissertation asks how settler Filipinos can be better relations to Indigenous lands and life within Canada. Through writing autoethnographic reflections as a settler Filipina and conducting close readings of Indigenous, diasporic Asian, and Filipino literary art, I think through how settler Filipinos can ethically support Indigenous communities and movements. My analysis centres three ideas: that, to be better relations, Filipinos should 1) un-first our perspectives of the territories colonially called Canada, 2) practice what Gregory Cendana (2020) and DRUM — Desis Rising Up and Moving call embodied, transformative solidarity, and 3) revitalize the principle of kapwa, a Filipino belief of shared relationality between and across all of creation. I examine these ideas in four chapters. In chapter 1, I discuss colonization in the Filipino context, to understand the colonially caused migration that has resulted in many Filipinos settling in Canada. In chapter 2, I study a map of Vancouver, Eden Robinson’s novel Monkey Beach (2000), and the poem beholden (2018) by Rita Wong and Fred Wah; here I borrow Jean M. O’Brien’s concept of “firsting” — those acts that portray “the colonial regime” as “the ‘first’ to bring ‘civilization’ and authentic history to” Turtle Island (xv) — and Melissa K. Nelson’s concept of “eco-eroticism” — intimate human-land, human-water, and human-nonhuman connections — to argue that these texts un-first common conceptualizations of Canada and uplift eco-erotic relations with/in Indigenous territories. In chapter 3, I discuss the potentials and limitations of settler Filipino solidarity work with Indigenous nations, sharing my experiences in organizing as well as working with scenes of solidarity within Catherine Hernandez’s novel Scarborough (2017) and Jill Carter’s play Encounters at the “Edge of the Woods” (2019). In chapter 4, I analyse José Rizal’s novels Noli Me Tangere (1887) and El Filibusterismo (1891) to examine how colonialism has disconnected Filipinos from the principle of kapwa, and to discuss the need to revitalize kapwa in the process of being better relations. The conclusion recognizes the need to extend these conversations to consider how Filipinos can be better relations to Black communities as well as to Indigenous communities in the Philippines.
Identifying tissue specific transcriptional regulatory elements in mammalian genomes
Keywords: Enhancers
Gene expression regulation
Genomics
Pluripotent Stem Cells
Transcription factor
Transcription factor binding site

Mammalian genomes are >98% non-coding and the function of most of this DNA remains unknown. Enhancers are one of the major components of the complex non-coding genome, which regulate gene expression in a tissue specific manner by binding transcription factors (TFs). Moreover, non-coding regulatory regions are critical for normal development, inter intra-species evolution and often inappropriately regulated in disease contexts, yet we have only a limited understanding of these regions at a sequence level. The analysis of known enhancers has failed to provide a sequence code of enhancers, how many and which specific TFs are required to build a functional enhancer. To better understand the transcriptional regulatory code, I identified embryonic stem (ES) cell enhancers using mouse-human comparative epigenomics and machine learning. I found genomic regions with conserved binding of multiple transcription factors (TFs) in mouse and human embryonic stem cells (ESCs) are enriched in a diverse repertoire of transcription factor binding sites (TFBS) including known and novel ESC regulators. The accuracy of these predictions was confirmed using enhancer reporter assays and site directed mutagenesis of conserved TFBS in natural enhancers as well as the construction of synthetic enhancers. As I found that natural enhancers have on average 12 unique conserved TFBS I hypothesized that >10 unique TFBS are important for regulatory activity. Multiple synthetic enhancers constructed from >10 unique TFBS had robust enhancer activity, whereas sequences containing
Constructing the Modern Hacienda: Land, Work, Memory and Migration in the Seasonal Agricultural Worker Program
Keywords: Agriculture
Canada
Labor
Mexico
Migration

This dissertation examines the everyday lives of Mexican migrants participating in the Seasonal Agricultural Worker Program (SAWP). I examine the SAWP as an example of how the Canadian state mobilizes neoliberal governance techniques to decentralize power and court political support, while also establishing labour stratification according to immigration status, race, and occupational sector. I use migrants’ experiences in this context to critically examine neoliberal interventions as they affect power relations, land, development, and work. I am particularly interested in interrogating the effectiveness of these interventions as well as investigating what forms of resistance, control, and discipline are possible as they become vernacularized within local power relations. To do this, I draw on 14 months of fieldwork conducted between 2012 and 2014 in both Canada and Mexico. My fieldwork was multi-sited and included working on Meadowvale Farms, a medium-sized vegetable farm in Southern Ontario, as well as living in the Central Mexican village of Atzala. The first portion of this dissertation examines how migrants are constructed as a productive and manageable workforce. I argue that examinations of the structural and historical factors contributing to migrants’ exploitation only provide a partial understanding of this process. It is often in the “offstage” life of the farm, conducted in intimate spaces such as bunkhouses and working spaces, that these factors are both reproduced and challenged. The latter portion of the dissertation is based on fieldwork conducted in Mexico and focuses on the themes of rural development programs, land tenure, and resistance as they relate to the lives of SAWP migrants. I argue that neoliberal state-making has fundamentally changed the role of land and work in rural Mexico and that these shifts have created an increasingly competitive environment that has often excluded SAWP migrants. However, these changes also have limited and often contradictory affects in local communities such as Atzala. My central argument is that SAWP migrants negotiate these interventions and changes through using moments of impasse to explore novel ways of resisting and refusing attempts to coopt their participation in acts of self-discipline and conformity.
With and Beyond Marx: The Global Circulation of Marxism through Calcutta
Keywords: history of ideas
Intellectual history
Internationalism
Marxism
media studies
Nationalism

This dissertation builds on but also revises the existing approaches to global intellectual history bringing insights from media and cultural studies. It examines one of the most global discourses of the twentieth century, Marxism, seen from Calcutta, India. I present the circulation of Marxism through Calcutta as a historically situated problem located within contemporary debates in mass mediation which also generated the works of Gramsci, Benjamin, and the Frankfurt School. I examine the discourse in terms of the aspects of its mediation: technology, textuality and meaning, and publics. I present the Marxist publics, especially the Popular Front (the Depression-era platform for anti-Fascist cultural movement), as a field of struggle between the self-identified “people’s group” and those whom they called the “intellectuals.” Secondly, I show how the people’s group privileged folk performances and choir songs while the so-called intellectuals championed the print media, and how these technologies of mass mediation were incorporated into the political economy of nation building in postcolonial India. Finally, I demonstrate how the meanings of Marxism in Calcutta played out within the double bind of internationalism and nationalism, through an examination of the generation, development and repudiation of the narrative of the Indian Renaissance. In summary, my dissertation brings historical methods and archives to cultural and media studies, detailing what Raymond Williams has called “cultural materialism,” in a bid to critique technological determinism in media studies.
Developing Conformationally Constrained L-Shaped HDAC8 Selective Inhibitors for Epigenetic Therapies
Keywords: Cancer
Chemotherapy
Conformationally Constrained
Epigenetics
Histone Deacetylase Inhibitors
Medicinal Chemistry

This thesis details my PhD journey towards bridging the gap between the clinical demand of emerging epigenetic therapies and developing safer therapies by developing unique methods to target histone deacetylases (HDACs) selectively. HDACs are at the forefront of epigenetic therapies due to their involvement in gene transcription, cellular signaling, and other biological processes governing diseased phenotypes. My work on selectively targeting HDACs led to the discovery of MMH409, the most potent HDAC8 inhibitor known to date, demonstrating 23 nM HDAC8 in vitro potency and 410-fold selectivity. This was done by serendipitously discovering that benzanilides have a unique conformational equilibrium that, upon N-alkylation, allows them to adopt an L-shaped E¬-configuration that fits as the perfect ‘tetris piece’ into the HDAC8 L-shaped catalytic tunnel. Furthermore, these benzanilide pharmacophores have drug-like characteristics and have the potential to be useful in the clinic against the HDAC8-relevant late-stage neuroblastoma. These benzanilides were further tested in HDAC8-relevant parasite model, Schistosoma mansoni, that showed no direct correlation to its SmHDAC8 activity. This study yielded MMH258 as a reasonable lead for future studies on treating the parasitic disease. Furthermore, our results indicate that these benzanilide-based highly potent and selective hHDAC8 inhibitors show minimal SmHDAC8 potency and have a differential binding to hHDAC8 and SmHDAC8 indicating a potential for developing inhibitors selective for SmHDAC8 for targeting the parasitic disease with a higher therapeutic index.
CSF1 Maintains Myeloid Cell Homeostasis in the Aortic Intima
Keywords: Autoimmune
Cardiovascular Disease
Intimal myeloid cells homeostasis
Vascular biology
Vascular homeostasis

Myeloid cells reside in all normal tissues including normal arteries and their abundance is tightly regulated1,2. In the normal mouse aortic intima, myeloid cell numbers increase and reach a plateau at 16 to 20 weeks of age. Colony stimulating factor-1 (CSF1) is a key regulator of myeloid cell abundance, and mice deficient in CSF1 exhibit a profound reduction, in myeloid cells both in the artery intima and the adventitia. This thesis investigates the relevant source of CSF1 that regulate the abundance of myeloid cells in arteries. Experiments confirmed that the absolute numbers of intimal CD11c+ myeloid cells and adventitial CD68+ myeloid cells were reduced by >95% in CSF1-deficient (Csf1op/op) mice. Neutralizing antibodies to CSF1 or CSF1 receptor delivered for 1 week by a subcutaneously-implanted osmotic pump, reduced intimal and adventitial cells by 85% and 90%, respectively. Immunostaining revealed that CSF1 expression colocalized with luminal endothelial cells preferentially in the lesser curvature of the aortic arch, a region that harbors resident myeloid cells in the intima and is predisposed to atherosclerosis. Single cell mRNA sequencing of carefully isolated aortic intimal cells revealed preferential expression of CSF1 by endothelial cells while CSF1R is preferentially expressed by myeloid cells. Based on this observation, conditional endothelial-specific deletion of CSF1 in both Cdh5-CreERT2;CSF1flox/flox and BMX-Cre-ERT2;CSF1flox/flox mice revealed significantly reduced intimal, but not adventitial, myeloid cells. Circulating plasma levels of CSF1 were not changed in Cdh5-CreERT2;CSF1flox/flox mice, suggesting that endothelial cells are not the main source of soluble CSF1 in the plasma. Overall, our data demonstrate that CSF1/CSF1R signaling is required for the homeostatic maintenance of the intimal myeloid cells and that the production of CSF1 by adjacent arterial endothelial cells is critical. This defines an arterial intimal cell niche.
Translational Analyses of Cortical Microcircuitry Cell Type-Specific Transcriptomes in Major Depressive Disorder and Chronic Stress
Keywords: Animal models
Anterior cingulate cortex
Cell types
Depression
RNA sequencing
Stress

Major depressive disorder (MDD) is a common and debilitating psychiatric disorder with a lifetime prevalence of 20%. Current antidepressants are ineffective in 50% of patients, necessitating a deeper understanding of MDD neurobiology and of chronic stress models used in drug discovery and development. The subgenual anterior cingulate cortex (sgACC) regulates mood states, is hyperactive in MDD, and is composed of repeated cell microcircuit motifs. Cortical microcircuits contain excitatory pyramidal (PYR) cells, regulated by inhibitory Somatostatin- (SST), Parvalbumin- (PV), and Vasoactive intestinal peptide- (VIP) expressing interneurons. SST, PV, and VIP-cells target PYR-cell dendrites (input regulation), soma/axon-hillock (output regulation), and other interneurons (disinhibition), respectively. Human postmortem and rodent studies show impaired PYR-cell dendritic morphology and decreased SST-cell markers in MDD or after unpredictable chronic mild stress (UCMS) in mice. To address the lack of cell-specific transcriptomic knowledge, RNA-sequencing was used to transcriptomically profile microcircuit cell-types from postmortem sgACC samples of MDD patients and controls, and the medial prefrontal cortex of UCMS-exposed mice and controls. Cell type-specific differential expression and microcircuit-wide gene co-expression analyses were used to characterize biological changes. The results indicate that each microcircuit cell type responded uniquely in MDD and UCMS. Synaptic structure and function, bioenergetics, and cellular stress was differentially impacted across cell types. Notably, synaptic deficits were observed in PYR-cells, and evidence of unfolded protein response signaling in SST-cells replicated existing research. UCMS was characterized by an increased co-ordination of microcircuit cell types, centred around PYR-cells as a hub cell type. In MDD, there was a loss in cell type coordination across the microcircuit, and PYR-cells remained centralized in this reduction. Changes in MDD were broadly consistent with long-term compensatory changes or homeostatic adaptations (years of disease) to those observed in UCMS (4-6 weeks of stress). Taken together, these findings suggest that SST and VIP-cells are vulnerable in UCMS and MDD, potentially converging on altered PYR-cell regulation. These findings provide a cross-species resource for future hypothesis-driven studies, suggest that UCMS replicates cell type-specific vulnerabilities of MDD that model the early disease phase, and identify cell type-specific changes involved in MDD and UCMS warranting exploration for antidepressant-like effects.
The Transcriptional Regulation and Role of XERICO in Arabidopsis thaliana Development and Stress Responses
Keywords: ABA
Abiotic stress
Arabidopsis thaliana
CBF4
Drought
XERICO

Every year, periods of agricultural drought devastate crop yields globally, limiting food production and leading to significant economic losses. The phytohormone abscisic acid (ABA) accumulates during drought and is crucial for the plant to mount an effective stress response. Arabidopsis thaliana XERICO (XER) is a stress-inducible E3 ubiquitin ligase that plays a role in regulating ABA levels, stomatal closure, and drought tolerance. While the function XER in ABA homeostasis and drought tolerance has been substantiated in various monocot and dicot species, other roles for XER in controlling plant stress responses remain unknown. In addition, knowledge of the mechanisms governing XER transcriptional regulation under stress conditions is limited. Thus, this work aimed to further characterize the function of XER in Arabidopsis stress responses and to shed light on the regulation of its spatiotemporal expression pattern by stress stimuli. The data in this thesis demonstrate that XER expression is repressed by stress-responsive CBF4/DREB1D, which was identified by yeast one-hybrid screening and established as a negative regulator of ABA responses and drought tolerance through CRISPR/Cas9 mutant analysis. Furthermore, by characterizing loss-of-function xer mutants and transgenic lines overexpressing a RING-mutated XER variant, XER was found to inhibit stomatal development and gibberellin (GA) signaling. Lastly, 88 ABA-regulated putative XER interactors were identified by high-throughput yeast two-hybrid screening, unveiling potential mechanisms and pathways through which XER may modulate ABA and stress responses. Overall, the results presented in this thesis reveal that XER contributes to stress responses by enhancing ABA and repressing GA signaling, as well as by restricting stomatal development, and that tight transcriptional control of XER expression by CBF4 is important for the plant to balance plant growth and survival under adverse environmental conditions such as drought.
The Free City of Danzig: Between the Vistula and the World (1919-1933)
Keywords: free cities
Free City of Danzig
Germany
History
Poland
Wolne Miasto Gdansk

This dissertation demonstrates, using the example of the Free City of Danzig (1920-1939)—a city-state that was established as part of the Treaty of Versailles to grant Poland access to the Baltic Sea and local autonomy to the predominantly German population—that encounters in regions of conflict are characterized by both antagonism and cooperation. Showcasing cooperative and antagonistic relationships between the population and the government in three institutions within and outside the city—a shipyard, a casino, and a university—as well as a range of illicit transnational relationships, this project argues that Danzig’s political leaders tried to make sense of the ambiguous Free City status through exacerbating divides along national, ethnic and class lines as well as through (unintentionally) creating diverse, multiethnic spaces filled with immigrants who seized the opportunities of the city-state and contributed to its cultural and economic advancement. Danzig’s local population grappled with the bifurcated governance framework in various related ways, but local support for the city-state solution remained consistently low. This project reveals that lack of support for the Free City was not an instinctive reaction characterized by German nationalism (a view dominant in the historiography) but was rather due to the hardship that the majority of the population experienced because of significant changes in the economics of everyday life after the establishment of the Free City. The local population’s negative response originated in the emergence of what this dissertation calls a “post-war borderland society,” a community that languished in post-war conditions longer than other parts of the former German Empire, while almost overnight it confronted a wide array of new (legal and illicit) socio-economic opportunities.Based on research in German, Polish, American and Swiss archives and bringing German and Polish printed primary and secondary sources into conversation, this dissertation moves beyond the dominant historiographical narrative about German-Polish antagonism in Danzig to offer a nuanced interpretation of the history of a city most commonly regarded as nothing but a failed geopolitical experiment that contributed to the outbreak of the Second World War.