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Published on: July 16, 2013
2',5'-Dihydroxychalcone down-regulates endothelial connexin43 gap junctions and affects MAP kinase activation
Yi-Nan Lee1, Hung-I Yeh, Tin-Yi Tian
1Cardiovascular Division, Department of Internal Medicine, Mackay Memorial Hospital, Mackay Junior College of Nursing, Taipei Medical University, Taipei, Taiwan, ROC.
Toxicology
|September 3, 2002
Summary
2
Area of Science:
- Molecular Biology
- Cell Biology
- Biochemistry
Background:
- Connexin43 (Cx43) is crucial for gap-junctional communication in endothelial cells.
- Dysregulation of Cx43 impacts vascular function.
- Chalcones are plant-derived compounds with potential biological activities.
Purpose of the Study:
- To investigate the effect of 2',5'-dihydroxychalcone on Cx43 expression and function in human umbilical vein endothelial cells (HUVEC).
- To elucidate the underlying mechanisms, including the involvement of MAP kinase signaling and proteolysis pathways.
Main Methods:
- Dose-dependent analysis of Cx43 expression.
- Fluorescence recovery after photobleaching (FRAP) to assess gap-junctional communication.
- Investigation of MAP kinase activation and proteolysis pathways using specific inhibitors and varying fetal calf serum (FCS) concentrations.
Main Results:
- 2',5'-dihydroxychalcone significantly reduced Cx43 expression and gap-junctional communication in HUVECs in a dose-dependent manner.
- The compound's effect on Cx43 was blocked by protease inhibitors but not by a MAP kinase inhibitor (PD98059).
- 2',5'-dihydroxychalcone exhibited dual effects on MAP kinase activation, inhibiting it at low FCS levels and activating it at high FCS levels.
Conclusions:
- 2',5'-dihydroxychalcone down-regulates Cx43 expression and gap-junctional communication in HUVECs primarily by enhancing proteolysis.
- The compound has complex, concentration-dependent effects on MAP kinase activation.
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