Korean J Physiol Pharmacol.  2002 Apr;6(2):109-112.

The Regulation of AP-1 DNA Binding Activity by Long-term Nicotine Stimulation in Bovine Adrenal Medullary Chromaffin Cells: Role of Second Messengers

• Lee JK
• Choi SS
• Suh HW

Abstract

The signal pathways involved in the regulation of AP-1 DNA binding activity in long-term nicotine stimulated bovine adrenal medullary chromaffin (BAMC) cells have not been well characterized. To understand the involvement of second messengers in the regulation of AP-1 DNA binding activity, the present study was designed to define the time-course for inhibition of nicotine-induced responses by cholinergic antagonists, Ca2+ and calmodulin (CaM) antagonists, and calcium/calmodulin-dependent protein kinase (CaMK) II inhibitor using electrophoretic mobility shift assay. Nicotine (10microM) stimulation increased AP-1 DNA binding activity at 24 hr after treatment. Posttreatment with hexamethonium (1 mM) plus atropine (1microM) (HA), nimodipine (1microM), or calmidazolium (1microM) at 0.5, 3, and 6 hr after the nicotine treatment significantly inhibited the AP-1 DNA binding activity increased by long-term nicotine stimulation. However, posttreatment with HA, nimodipine, or calmidazolium at 9 or 12 hr after the nicotine treatment did not affect the nicotine-induced increase of AP-1 DNA binding activity. The pretreatment of BAMC cells with various concentrations of KN-62 inhibited the increase of AP-1 DNA binding activity induced by nicotine in a concentration-dependent manner. KN-62 (10microM) posttreatment beginning at 0.5, 3, or 6 hr after the nicotine treatment significantly inhibited the increase of AP-1 DNA binding activity. However, KN-62 posttreatment beginning at 9 or 12 hr after the nicotine treatment did not affect the increase of AP-1 DNA binding activity. This study suggested that stimulation (for at least 6 hr) of nicotinic receptors on BAMC cells was necessary for increase of AP-1 DNA binding activity, and activation of Ca2+, CaM, and CaMK II up to 6 hr at least seemed to be required for the increase of nicotine-induced AP-1 DNA binding activity.

Keyword

AP-1 DNA binding activity; Bovine adrenal medullary chromaffin cells; Nicotine; Second messenger

MeSH Terms

Atropine
Calmodulin
Cholinergic Antagonists
Chromaffin Cells*
DNA*
Electrophoretic Mobility Shift Assay
Hexamethonium
Nicotine*
Nimodipine
Protein Kinases
Receptors, Nicotinic
Second Messenger Systems*
Signal Transduction
Transcription Factor AP-1*
Atropine
Calmodulin
Cholinergic Antagonists
DNA
Hexamethonium
Nicotine
Nimodipine
Protein Kinases
Receptors, Nicotinic
Transcription Factor AP-1