Transcriptomic Analysis of in-vitro foamy macrophages
- Title
- Transcriptomic Analysis of in-vitro foamy macrophages
- Other Titles
- 생체 외 포말성 대식세포군의 전사체 변화 분석
- Author
- 이지혜
- Advisor(s)
- 최재훈
- Issue Date
- 2020-02
- Publisher
- 한양대학교
- Degree
- Master
- Abstract
- Macrophages provide a fundamental role in the immune system and atherosclerosis, reacting
immediately upon foreign pathogens through phagocytosis. Phagocytic cells such as monocytes or
macrophages uptake oxidized low-density lipoproteins in order to maintain cholesterol homeostasis
in the artery, and during this process, membrane-bound lipid droplets are accumulated in
macrophages, leading to formation of foam cells.
For in-vitro foam cell studies, macrophages are treated with oxLDL for foam cell formation.
Macrophages from various origins are used, and the most widely used cell systems are RAW 264.7
cells, bone marrow-derived macrophages (BMDMs) and Thioglycollate-medium elicited macrophages
(TGEMs). The problems associated with these in-vitro foam cell models are that they express different
cell surface markers or are inflammation-induced, leading to inconsistent in-vivo and in-vitro results.
By re-analyzing ChIP sequencing data of TGEMs and observing the main macrophage subset upon
Thioglycollate-medium injection provided clues that resident peritoneal macrophages without any
inflammatory stimuli may show similar phenotype compared to in-vivo foam cells.
In order to select the best in-vitro foam cell model, transcriptome analysis was done on foam
cells formed from RAW 264.7, BMDMs, TGEMs and resident peritoneal macrophages. Comparing
mRNA expression levels of various cell systems by RT-PCR with recent publication data (Kim et al.,
Circulation Research. 2018) and bulk RNA sequencing indicated resident peritoneal macrophages
show analogous mRNA expressions and cellular pathways compared to in-vivo foam cells. Observation
of upstream regulators showed key genes that are involved in the cellular changes upon oxLDL
stimulation.
We also observed gene expression changes in in-vitro foam cells representing various
atherosclerotic stages. By treating oxLDL for prolonged time points, we found rapid downregulation
of inflammatory gene expressions, and succeeding upregulation of cholesterol related gene
expressions. These collectively suggest in in-vitro induced foam cell studies by using resident
peritoneal macrophages, which is composed of tissue-resident large peritoneal macrophages, may be
the most adequate in-vitro foam cell model. In-vitro atherosclerosis by using this cell system may lead
to further future transcriptome studies regarding the effect of upstream regulators, resolution of IL-
1β-induced inflammation, LXR activation and SREBP signaling leading to cholesterol homeostasis in
hyperlipidemia.
- URI
- https://repository.hanyang.ac.kr/handle/20.500.11754/123457http://hanyang.dcollection.net/common/orgView/200000437122
- Appears in Collections:
- GRADUATE SCHOOL[S](대학원) > LIFE SCIENCE(생명과학과) > Theses (Master)
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