MicroRNA-495 Ameliorates Cardiac Microvascular Endothelial Cell Injury and Inflammatory Reaction by Suppressing the NLRP3 Inflammasome Signaling Pathway.

Abstract

BACKGROUND/AIMS:

In recent years, microRNA-495 (miR-495) has been reported to be a tumor-suppressor miR that is down-modulated in cancers. However, its potential mechanism remains unknown. Therefore, this study aimed to demonstrate the role of miR-495 in cardiac microvascular endothelial cell (CMEC) injury and inflammatory reaction by mediating the pyrin domain-containing 3 (NLRP3) inflammasome signaling pathway.

METHODS:

Overall, 40 mice were assigned into myocardial ischemia/reperfusion injury (MIR) and sham groups. After model establishment, the levels of troponin T (TnT), troponin I (TnI), N-terminal pro-B-type natriuretic peptide (NT-proBNP), creatine kinase isoenzyme MB (CK-MB), myoglobin (MYO), tumor necrosis factor-alpha (TNF-α), and interleukin 1beta (IL-1β) were detected by Enzyme-Linked Immunosorbent Assay (ELISA). Apoptosis was evaluated using Terminal deoxy (d)-UTP nick end labeling (TUNEL) staining, the level of NLRP3 protein was determined by immunohistochemical assay, and miR-495 was detected by in situ hybridization (ISH). The infarct size was determined using 2, 3, 5-triphenyltetrazolium chloride (TTC) staining. The expression of miR-495 and the mRNA and protein levels of NLRP3, TNF-α, IL-1β, IL-18 and caspase-1 were evaluated by RT-qPCR and western blot analysis. After transfection, the cells were treated with a miR-495 mimic, a miR-495 inhibitor, or siNLRP3. Cell proliferation was measured by the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay and cell cycle and apoptosis by flow cytometry.

RESULTS:

Mice with myocardial I/R injury had elevated levels of TnT, TnI, NT-proBNP, CK-MB, MYO, TNF-α and IL-1β; enhanced cell apoptosis; increased expression of NLRP3, TNF-α, IL-1β, IL-18 and caspase-1; and decreased miR-495 expression. MiR-495 was confirmed to target NLRP3. Moreover, miR-495 reduced the mRNA and protein levels of NLRP3, TNF-α, IL-1β, IL-18 and caspase-1, inhibited cell apoptosis and decreased cells at the G0/G1 phase while improving cell proliferation and increasing cells at the S phase. However, the effects of NLRP4 were proved to be reciprocal.

CONCLUSION:

In conclusion, the current study indicated that miR-495 improved CMEC injury and inflammation by suppressing the NLRP3 inflammasome signaling pathway.

• Authors: Tao Zhou, Dao-Kang Xiang, Sui-Ning Li, Lie-Hong Yang, Lu-Fang Gao, Chao Feng
• Journal: Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry, and pharmacology (Cell Physiol Biochem) Vol. 49 Issue 2 Pg. 798-815 ( 2018) ISSN: 1421-9778 [Electronic] Germany
• PMID: 30165354 (Publication Type: Journal Article)
• Copyright: © 2018 The Author(s). Published by S. Karger AG, Basel.

Chemical References

• 3' Untranslated Regions
• Antagomirs
• Inflammasomes
• Interleukin-18
• Interleukin-1beta
• MIRN495 microRNA, mouse
• MicroRNAs
• NLR Family, Pyrin Domain-Containing 3 Protein
• RNA, Small Interfering
• Caspase 1

Topics

• 3' Untranslated Regions
• Animals
• Antagomirs (metabolism)
• Apoptosis
• Caspase 1 (genetics, metabolism)
• Disease Models, Animal
• Endothelial Cells (cytology, metabolism)
• G1 Phase Cell Cycle Checkpoints
• Inflammasomes (metabolism)
• Interleukin-18 (genetics, metabolism)
• Interleukin-1beta (genetics, metabolism)
• Mice
• Mice, Inbred C57BL
• MicroRNAs (antagonists & inhibitors, genetics, metabolism)
• Myocardial Reperfusion Injury (metabolism, pathology)
• Myocardium (metabolism, pathology)
• NLR Family, Pyrin Domain-Containing 3 Protein (antagonists & inhibitors, genetics, metabolism)
• RNA Interference
• RNA, Small Interfering (metabolism)
• Signal Transduction