Unraveling the Functions of Wiskott-Aldrich Syndrome Protein: Insights into RNA Splicing, Nucleolus Regulation, and Immunosenescence

dc.contributor.advisorLi, Mo
dc.contributor.authorZhou, Xuan
dc.contributor.committeememberAdamo, Antonio
dc.contributor.committeememberBlilou, Ikram
dc.contributor.committeememberZhou, Jiaxi
dc.contributor.departmentBiological and Environmental Science and Engineering (BESE) Division
dc.date.accessioned2023-09-05T13:14:48Z
dc.date.available2023-09-05T13:14:48Z
dc.date.issued2023-08
dc.description.abstractThe Wiskott-Aldrich syndrome (WAS) is an X-linked primary immunodeficiency characterized by microthrombocytopenia, eczema, recurrent infections, autoimmunity, and predisposition to malignancy. Mutations in the WAS gene lead to dysfunction of the Wiskott-Aldrich syndrome protein (WASP), a multifunctional regulator implicated in various hematopoietic and immune processes. While some disease phenotypes have been linked to classical WASP's actin nucleation function, recent advances have unveiled additional nuclear functions, such as involvement in R-loop formation, transcriptional regulation during T helper 1 cell differentiation, and homology-directed repair. However, a comprehensive understanding of WASP's multifaceted functions remains elusive. We employ induced pluripotent stem cells (iPSCs) and Clustered Regularly Interspaced Palindromic Repeats (CRISPR) technology, specifically the CRISPR-Cas9 system, as powerful tools to investigate the mechanisms underlying WASP's functions. We first explore the consequences of WASP loss on RNA splicing. We reveal its critical role in RNA splicing. WASP-deficiency causes widespread alterations RNA splicing patterns and epigenetic activation of splicing factor gene promoters. Additionally, we uncover its involvement in liquid-liquid phase separation, forming phase-separated condensates to dynamically regulate the splicing machinery. In the second part of this thesis, our investigation uncovers the presence of WASP within the nucleolus and its interactions with key nucleolar proteins. Intriguingly, depletion of WASP leads to significant reduction in nucleolar size, disrupted nucleolar morphology, and decreased ribosomal RNA transcription, unveiling its critical role in nucleolus structure and function. Furthermore, we successfully recapitulated nucleolus changes and ribosomal RNA profile in patient samples. Lastly, we investigate immunosenescence, a crucial aspect of aging-related immune dysregulation, in the context of WAS. Through the use of WASP-deficient macrophage cells, our study revealed several distinctive features associated with immunosenescence in WASP-KO-iMPs. These include increased senescent cell proportions, heightened expression of senescence-associated secretory phenotype genes, nuclear deformation, loss of heterochromatin, and enhanced susceptibility to DNA damage. These preliminary findings offer valuable insights into our understanding of immunosenescence within the framework of WASP-deficient macrophages and its association with conditions related to WAS. In conclusion, the mechanistic study of WASP has unveiled its novel roles in regulating RNA splicing, nucleolus structure and function, as well as its potential involvement in immunosenescence.
dc.identifier.doi10.25781/KAUST-8UQE2
dc.identifier.orcid0000-0003-2820-4104
dc.identifier.urihttp://hdl.handle.net/10754/694157
dc.language.isoen
dc.person.id157738
dc.relation.issupplementedbyN/A
dc.rights.accessrightsAt the time of archiving, the student author of this dissertation opted to temporarily restrict access to it. The full text of this dissertation will become available to the public after the expiration of the embargo on 2024-09-05.
dc.rights.embargodate2024-09-05
dc.subjectWiskott-Aldrich syndrome
dc.subjectWASP
dc.subjectRNA splicing
dc.subjectnucleolus regulation
dc.subjectimmunosenescence
dc.titleUnraveling the Functions of Wiskott-Aldrich Syndrome Protein: Insights into RNA Splicing, Nucleolus Regulation, and Immunosenescence
dc.typeDissertation
display.details.left<span><h5>Embargo End Date</h5>2024-09-05<br><br><h5>Type</h5>Dissertation<br><br><h5>Authors</h5><a href="https://repository.kaust.edu.sa/search?query=orcid.id:0000-0003-2820-4104&spc.sf=dc.date.issued&spc.sd=DESC">Zhou, Xuan</a> <a href="https://orcid.org/0000-0003-2820-4104" target="_blank"><img src="https://repository.kaust.edu.sa/server/api/core/bitstreams/82a625b4-ed4b-40c8-865a-d6a5225a26a4/content" width="16" height="16"/></a><br><br><h5>Advisors</h5><a href="https://repository.kaust.edu.sa/search?query=orcid.id:0000-0003-0827-8907&spc.sf=dc.date.issued&spc.sd=DESC">Li, Mo</a> <a href="https://orcid.org/0000-0003-0827-8907" target="_blank"><img src="https://repository.kaust.edu.sa/server/api/core/bitstreams/82a625b4-ed4b-40c8-865a-d6a5225a26a4/content" width="16" height="16"/></a><br><br><h5>Committee Members</h5><a href="https://repository.kaust.edu.sa/search?query=orcid.id:0000-0003-1080-3547&spc.sf=dc.date.issued&spc.sd=DESC">Adamo, Antonio</a> <a href="https://orcid.org/0000-0003-1080-3547" target="_blank"><img src="https://repository.kaust.edu.sa/server/api/core/bitstreams/82a625b4-ed4b-40c8-865a-d6a5225a26a4/content" width="16" height="16"/></a><br><a href="https://repository.kaust.edu.sa/search?query=orcid.id:0000-0001-8003-3782&spc.sf=dc.date.issued&spc.sd=DESC">Blilou, Ikram</a> <a href="https://orcid.org/0000-0001-8003-3782" target="_blank"><img src="https://repository.kaust.edu.sa/server/api/core/bitstreams/82a625b4-ed4b-40c8-865a-d6a5225a26a4/content" width="16" height="16"/></a><br>Zhou, Jiaxi<br><br><h5>Program</h5><a href="https://repository.kaust.edu.sa/search?spc.sf=dc.date.issued&spc.sd=DESC&f.program=Bioscience,equals">Bioscience</a><br><br><h5>KAUST Department</h5><a href="https://repository.kaust.edu.sa/search?spc.sf=dc.date.issued&spc.sd=DESC&f.department=Biological and Environmental Science and Engineering (BESE) Division,equals">Biological and Environmental Science and Engineering (BESE) Division</a><br><br><h5>Date</h5>2023-08</span>
display.details.right<span><h5>Access Restrictions</h5>At the time of archiving, the student author of this dissertation opted to temporarily restrict access to it. The full text of this dissertation will become available to the public after the expiration of the embargo on 2024-09-05.<br><br><h5>Abstract</h5>The Wiskott-Aldrich syndrome (WAS) is an X-linked primary immunodeficiency characterized by microthrombocytopenia, eczema, recurrent infections, autoimmunity, and predisposition to malignancy. Mutations in the WAS gene lead to dysfunction of the Wiskott-Aldrich syndrome protein (WASP), a multifunctional regulator implicated in various hematopoietic and immune processes. While some disease phenotypes have been linked to classical WASP's actin nucleation function, recent advances have unveiled additional nuclear functions, such as involvement in R-loop formation, transcriptional regulation during T helper 1 cell differentiation, and homology-directed repair. However, a comprehensive understanding of WASP's multifaceted functions remains elusive. We employ induced pluripotent stem cells (iPSCs) and Clustered Regularly Interspaced Palindromic Repeats (CRISPR) technology, specifically the CRISPR-Cas9 system, as powerful tools to investigate the mechanisms underlying WASP's functions. We first explore the consequences of WASP loss on RNA splicing. We reveal its critical role in RNA splicing. WASP-deficiency causes widespread alterations RNA splicing patterns and epigenetic activation of splicing factor gene promoters. Additionally, we uncover its involvement in liquid-liquid phase separation, forming phase-separated condensates to dynamically regulate the splicing machinery. In the second part of this thesis, our investigation uncovers the presence of WASP within the nucleolus and its interactions with key nucleolar proteins. Intriguingly, depletion of WASP leads to significant reduction in nucleolar size, disrupted nucleolar morphology, and decreased ribosomal RNA transcription, unveiling its critical role in nucleolus structure and function. Furthermore, we successfully recapitulated nucleolus changes and ribosomal RNA profile in patient samples. Lastly, we investigate immunosenescence, a crucial aspect of aging-related immune dysregulation, in the context of WAS. Through the use of WASP-deficient macrophage cells, our study revealed several distinctive features associated with immunosenescence in WASP-KO-iMPs. These include increased senescent cell proportions, heightened expression of senescence-associated secretory phenotype genes, nuclear deformation, loss of heterochromatin, and enhanced susceptibility to DNA damage. These preliminary findings offer valuable insights into our understanding of immunosenescence within the framework of WASP-deficient macrophages and its association with conditions related to WAS. In conclusion, the mechanistic study of WASP has unveiled its novel roles in regulating RNA splicing, nucleolus structure and function, as well as its potential involvement in immunosenescence.<br><br><h5>DOI</h5><a href="https://doi.org/10.25781/KAUST-8UQE2">10.25781/KAUST-8UQE2</a></span>
kaust.availability.selectionEmbargo the work for one year and then release for public access* on the internet through the KAUST Repository.
kaust.gpcburgundy.powell@kaust.edu.sa
kaust.request.doiyes
kaust.thesis.readyToSubmitYes, I confirm that I am ready to upload the following 3 documents (in PDF format): 1) Final thesis or dissertation. 2) Completed Defense Results form showing “pass” or “pass with conditions”. 3) Final Advisor Approval confirmation email (received after advisor completed the digital form).
orcid.id0000-0001-8003-3782
orcid.id0000-0003-1080-3547
orcid.id0000-0003-0827-8907
orcid.id0000-0003-2820-4104
refterms.dateFOA2023-09-05T13:14:49Z
thesis.degree.disciplineBioscience
thesis.degree.grantorKing Abdullah University of Science and Technology
thesis.degree.nameDoctor of Philosophy
Files
Original bundle
Now showing 1 - 3 of 3
Name:
Defense_results form_Xuan_Zhou.pdf
Size:
316.66 KB
Format:
Adobe Portable Document Format
Description:
Defense results form
Name:
King Abdullah University of Science & Technology Mail - Final Approval Form – 157738, Xuan Zhou, Ph.D_.pdf
Size:
153.63 KB
Format:
Adobe Portable Document Format
Description:
Final Advisor Approval Confirmation Email
Name:
Xuan_Zhou_PhD_thesis_Sep42023.pdf
Size:
30.85 MB
Format:
Adobe Portable Document Format
Description:
PhD Dissertation
License bundle
Now showing 1 - 1 of 1
Name:
license.txt
Size:
919 B
Format:
Item-specific license agreed upon to submission
Description: