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Tetramethylpyrazine in a Murine Alkali-Burn Model Blocks NFκB/NRF-1/CXCR4-Signaling-Induced Corneal Neovascularization.
- Source :
-
Investigative ophthalmology & visual science [Invest Ophthalmol Vis Sci] 2018 Apr 01; Vol. 59 (5), pp. 2133-2141. - Publication Year :
- 2018
-
Abstract
- Purpose: Tetramethylpyrazine (TMP) is the active ingredient extracted from the Chinese herb Chuanxiong. The purpose of our study was to identify the mechanism of therapeutic TMP suppression of pathologic chemokine receptor 4 (CXCR4) transcription.<br />Methods: C57BL/6J mice with alkali-burned corneas were treated with either TMP eye drops (1.5 mg/mL) or PBS. Corneal neovascularization (CNV) was measured and a clinical assessment was made by slit lamp microscopy. Expression of CXCR4 and the transcription factors nuclear respiratory factor-1 (NRF-1), nuclear factor kappa B (NFκB), forkhead box C1, and yin yang 1 were tracked by real-time RT-PCR and immunofluorescence staining of murine corneas. Western blot, real-time PCR, and immunofluorescence evaluated expression of related genes in human umbilical vein endothelial cells (HUVECs) after 200-μmol/L TMP treatment. In addition, plasmid transfection and chromatin immunoprecipitation assays elucidated the relationship among NRF-1, NFκB, and CXCR4.<br />Results: Corneas treated with TMP had smaller areas of neovascularization and scored better in clinical assessments. Injured corneas showed significantly elevated expressions of NRF-1, NFκB, and CXCR4 that were normalized in vivo by TMP treatment. Similarly, in HUVECs in vitro, TMP decreased expression of NRF-1, NFκB, and CXCR4. Overexpression of NFκB or NRF-1 raised the expression of CXCR4 in HUVECs, but not synergistically. Chromatin immunoprecipitation assays detected only NRF-1 bound to the CXCR4 promoter region, suggesting NFκB controls CXCR4 expression by upregulating NRF-1. Together, our data suggest TMP downregulates CXCR4 by repressing NRF-1 expression in CNV, likely indirectly by downregulating NFκB.<br />Conclusions: Our results implicate a novel mechanism wherein TMP inhibits neovascularization via an NFκB/NRF-1/CXCR4 circuit.
- Subjects :
- Animals
Blotting, Western
Burns, Chemical metabolism
Corneal Neovascularization pathology
Disease Models, Animal
Human Umbilical Vein Endothelial Cells
Humans
Mice
Mice, Inbred C57BL
NF-kappa B genetics
Nuclear Respiratory Factor 1 genetics
Real-Time Polymerase Chain Reaction
Receptors, CXCR4 genetics
Sodium Hydroxide
Vasodilator Agents therapeutic use
Burns, Chemical drug therapy
Corneal Neovascularization prevention & control
Eye Burns chemically induced
NF-kappa B metabolism
Nuclear Respiratory Factor 1 metabolism
Pyrazines therapeutic use
Receptors, CXCR4 metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1552-5783
- Volume :
- 59
- Issue :
- 5
- Database :
- MEDLINE
- Journal :
- Investigative ophthalmology & visual science
- Publication Type :
- Academic Journal
- Accession number :
- 29801148
- Full Text :
- https://doi.org/10.1167/iovs.17-23712