Abstract | BACKGROUND: Macrophages are one of the major cell types in innate immunity against microbial infection. It is believed that the expression of proinflammatory genes such as tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, and cyclooxygenase-2 (Cox-2) by macrophages is also crucial for activation of both innate and adaptive immunities. RNase L is an interferon (IFN) inducible enzyme which is highly expressed in macrophages. It has been demonstrated that RNase L regulates the expression of certain inflammatory genes. However, its role in macrophage function is largely unknown. METHODOLOGY: Bone marrow-derived macrophages (BMMs) were generated from RNase L(+/+)and (-/-) mice. The migration of BMMs was analyzed by using Transwell migration assays. Endocytosis and phagocytosis of macrophages were assessed by using fluorescein isothiocyanate ( FITC)-Dextran 40,000 and FITC-E. coli bacteria, respectively. The expression of inflammatory genes was determined by Western Blot and ELISA. The promoter activity of Cox-2 was measured by luciferase reporter assays. CONCLUSIONS/FINDINGS: Lack of RNase L significantly decreased the migration of BMMs induced by M-CSF, but at a less extent by GM-CSF and chemokine C-C motif ligand-2 (CCL2). Interestingly, RNase L deficient BMMs showed a significant reduction of endocytic activity to FITC-Dextran 40,000, but no any obvious effect on their phagocytic activity to FITC-bacteria under the same condition. RNase L impacts the expression of certain genes related to cell migration and inflammation such as transforming growth factor (TGF)-β, IL-1β, IL-10, CCL2 and Cox-2. Furthermore, the functional analysis of the Cox-2 promoter revealed that RNase L regulated the expression of Cox-2 in macrophages at its transcriptional level. Taken together, our findings provide direct evidence showing that RNase L contributes to innate immunity through regulating macrophage functions.
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Authors | Xin Yi, Chun Zeng, Hongli Liu, Xiaoli Chen, Ping Zhang, Boo Seok Yun, Ge Jin, Aimin Zhou |
Journal | PloS one
(PLoS One)
Vol. 8
Issue 12
Pg. e81269
( 2013)
ISSN: 1932-6203 [Electronic] United States |
PMID | 24324683
(Publication Type: Journal Article, Research Support, N.I.H., Extramural)
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Chemical References |
- Cytokines
- Ptgs2 protein, mouse
- Cyclooxygenase 2
- Endoribonucleases
- 2-5A-dependent ribonuclease
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Topics |
- Animals
- Cell Movement
- Cyclooxygenase 2
(genetics, metabolism)
- Cytokines
(biosynthesis)
- Endocytosis
- Endoribonucleases
(deficiency, metabolism)
- Macrophages
(cytology, enzymology, metabolism)
- Mice
- Mice, Inbred C57BL
- Phagocytosis
- Promoter Regions, Genetic
(genetics)
- Transcription, Genetic
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