Investigating how tenascin-C regulates miR-155 expression
Innate immunity is deeply reliant on post-transcriptional gene expression modulators such as microRNAs (miRNAs). miRNAs, such as miR-155, are involved in all levels of immune cell development, function and response, causing excessive inflammation and associating with several diseases when dysregulat...
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| Format: | Thesis (University of Nottingham only) |
| Language: | English |
| Published: |
2021
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| Online Access: | https://eprints.nottingham.ac.uk/65645/ |
| _version_ | 1848800253505961984 |
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| author | Zordan, N |
| author_facet | Zordan, N |
| author_sort | Zordan, N |
| building | Nottingham Research Data Repository |
| collection | Online Access |
| description | Innate immunity is deeply reliant on post-transcriptional gene expression modulators such as microRNAs (miRNAs). miRNAs, such as miR-155, are involved in all levels of immune cell development, function and response, causing excessive inflammation and associating with several diseases when dysregulated.
Tenascin-C is an extracellular matrix (ECM) glycoprotein specifically induced in lipopolysaccharide (LPS)-activated macrophages. It was found that tenascin-C was able to modulate miR-155 expression in bone marrow-derived macrophages (BMDMs) from mouse, consequently regulating pro-inflammatory cytokines, such as TNF-α. However, studies focusing on miRNA expression regulated by the ECM are still in their infancy, and how tenascin-C could regulate miR-155 expression remained unknown.
This work aimed to study the mechanism and form of tenascin-C involved in promoting miR-155 expression, specifically at what stage of miR-155 biogenesis tenascin-C was required and if the ECM-associated tenascin-C was the main actor in miR-155 regulation. Moreover, we aimed to identify the membrane receptor associating with tenascin-C during this regulation.
We demonstrated that tenascin-C was involved in regulating miR-155 specifically by activating receptors located on the plasma membrane of tenascin-C knockout (tnc-/-) and wild type (tnc+/+) macrophages from mice, induced with different pathogenic and sterile inflammation stimuli and measured by qPCR and northern blotting. Furthermore, lack of tenascin-C affected miR-155 expression post-transcriptionally, reducing precursor miRNA (pre-miR-155) availability in the cytoplasm, possibly influencing deficient Drosha-mediated cleavage of the primary miRNA (pri-miR-155), as determined by qPCR, northern blot and RNA immunoprecipitation.
Additionally, using a murine 3D cell culture model of ECM and inflammation developed by us, we could identify insoluble ECM-assembled tenascin-C as the form required for LPS-induced miR-155 regulation in macrophages. Indeed, ECM-assembled but not soluble tenascin-C was able to rescue miR-155 expression in tnc-/- BMDMs.
Finally, we identified a possible novel candidate cell-surface co-receptor or antagonist for tenascin-C that, when silenced enhanced miR-155 expression.
Altogether, this work reveals a novel regulatory mechanism of the inflammatory response to infection and identify a potential therapeutic target that could unveil new ways to control excessive inflammation. |
| first_indexed | 2025-11-14T20:48:37Z |
| format | Thesis (University of Nottingham only) |
| id | nottingham-65645 |
| institution | University of Nottingham Malaysia Campus |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-14T20:48:37Z |
| publishDate | 2021 |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | nottingham-656452025-02-28T15:12:33Z https://eprints.nottingham.ac.uk/65645/ Investigating how tenascin-C regulates miR-155 expression Zordan, N Innate immunity is deeply reliant on post-transcriptional gene expression modulators such as microRNAs (miRNAs). miRNAs, such as miR-155, are involved in all levels of immune cell development, function and response, causing excessive inflammation and associating with several diseases when dysregulated. Tenascin-C is an extracellular matrix (ECM) glycoprotein specifically induced in lipopolysaccharide (LPS)-activated macrophages. It was found that tenascin-C was able to modulate miR-155 expression in bone marrow-derived macrophages (BMDMs) from mouse, consequently regulating pro-inflammatory cytokines, such as TNF-α. However, studies focusing on miRNA expression regulated by the ECM are still in their infancy, and how tenascin-C could regulate miR-155 expression remained unknown. This work aimed to study the mechanism and form of tenascin-C involved in promoting miR-155 expression, specifically at what stage of miR-155 biogenesis tenascin-C was required and if the ECM-associated tenascin-C was the main actor in miR-155 regulation. Moreover, we aimed to identify the membrane receptor associating with tenascin-C during this regulation. We demonstrated that tenascin-C was involved in regulating miR-155 specifically by activating receptors located on the plasma membrane of tenascin-C knockout (tnc-/-) and wild type (tnc+/+) macrophages from mice, induced with different pathogenic and sterile inflammation stimuli and measured by qPCR and northern blotting. Furthermore, lack of tenascin-C affected miR-155 expression post-transcriptionally, reducing precursor miRNA (pre-miR-155) availability in the cytoplasm, possibly influencing deficient Drosha-mediated cleavage of the primary miRNA (pri-miR-155), as determined by qPCR, northern blot and RNA immunoprecipitation. Additionally, using a murine 3D cell culture model of ECM and inflammation developed by us, we could identify insoluble ECM-assembled tenascin-C as the form required for LPS-induced miR-155 regulation in macrophages. Indeed, ECM-assembled but not soluble tenascin-C was able to rescue miR-155 expression in tnc-/- BMDMs. Finally, we identified a possible novel candidate cell-surface co-receptor or antagonist for tenascin-C that, when silenced enhanced miR-155 expression. Altogether, this work reveals a novel regulatory mechanism of the inflammatory response to infection and identify a potential therapeutic target that could unveil new ways to control excessive inflammation. 2021-08-04 Thesis (University of Nottingham only) NonPeerReviewed application/pdf en cc_by https://eprints.nottingham.ac.uk/65645/1/Nicole%20Zordan%20PhD%20Thesis_Corrections.pdf Zordan, N (2021) Investigating how tenascin-C regulates miR-155 expression. PhD thesis, University of Nottingham. microRNAs tenascin-C glycoproteins immune system |
| spellingShingle | microRNAs tenascin-C glycoproteins immune system Zordan, N Investigating how tenascin-C regulates miR-155 expression |
| title | Investigating how tenascin-C regulates miR-155 expression |
| title_full | Investigating how tenascin-C regulates miR-155 expression |
| title_fullStr | Investigating how tenascin-C regulates miR-155 expression |
| title_full_unstemmed | Investigating how tenascin-C regulates miR-155 expression |
| title_short | Investigating how tenascin-C regulates miR-155 expression |
| title_sort | investigating how tenascin-c regulates mir-155 expression |
| topic | microRNAs tenascin-C glycoproteins immune system |
| url | https://eprints.nottingham.ac.uk/65645/ |