title: Mechanism of macrophage migration inhibitory factor-induced decrease of T-type Ca(2+) channel current in atrium-derived cells.
abstract: The T-type Ca(2+) current (I(Ca,T)) plays an important role in the pathogenesis of atrial fibrillation (AF). The present study sought to investigate the role of macrophage migration inhibitory factor (MIF), a pleiotropic cytokine, in the regulation of T-type Ca(2+) channels (TCCs) in atrial myocytes. We used the whole-cell voltage-clamp technique and biochemical assays to study the regulation and expression of I(Ca,T) in atrial myocytes. Gene levels of the α1G and α1H subunit of TCCs were decreased in human atrial tissue of patients with AF. In cultured atrium-derived myocytes (HL-1 cells), mouse recombinant MIF (20 or 40 nm, 24 h) suppressed peak I(Ca,T) in a concentration-dependent manner, impaired the voltage-dependent activation of I(Ca,T) and downregulated TCC α1G and α1H mRNA. The Src inhibitors genistein and PP1 significantly enhanced I(Ca,T). The reduction of I(Ca,T) and TCC subunit mRNA induced by recombinant MIF could be reversed by genistein and PP1. The TCC α1G associated with Src in HL-1 cells and mouse cardiomycytes. Macrophage migration inhibitory factor is involved in the pathogenesis of AF, probably by decreasing the T-type calcium current in atrium-derived myocytes through impairment of channel function and activation of c-Src kinases, representing a potential pathogenic mechanism in atrial fibrillation.
authors: Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong Academy of Medical Sciences, 96 Dongchuan Road, Guangzhou 510080, PR China.
authors: Fang
authors: F
authors: Rao
authors: Chun-Yu
authors: CY
authors: Deng
authors: Shu-Lin
authors: SL
authors: Wu
authors: Ding-Zhang
authors: DZ
authors: Xiao
authors: Wei
authors: W
authors: Huang
authors: Hai
authors: H
authors: Deng
authors: Su-Juan
authors: SJ
authors: Kuang
authors: Qiu-Xiong
authors: QX
authors: Lin
authors: Zhi-Xin
authors: ZX
authors: Shan
authors: Xiao-Ying
authors: XY
authors: Liu
authors: Jie-Ning
authors: JN
authors: Zhu
authors: Xi-Yong
authors: XY
authors: Yu
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D001281:Atrial Fibrillation; D000081247:CSK Tyrosine-Protein Kinase; D020747:Calcium Channels, T-Type / Q000502:physiology*; D002460:Cell Line; D005260:Female; D019833:Genistein / Q000494:pharmacology; D006325:Heart Atria / Q000166:cytology; D006801:Humans; D019746:Intramolecular Oxidoreductases / Q000494:pharmacology / Q000502:physiology*; D008263:Macrophage Migration-Inhibitory Factors / Q000494:pharmacology / Q000502:physiology*; D008297:Male; D051379:Mice; D008875:Middle Aged; D032383:Myocytes, Cardiac / Q000502:physiology; D018408:Patch-Clamp Techniques; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors; D011720:Pyrazoles / Q000494:pharmacology; D011743:Pyrimidines / Q000494:pharmacology; D011994:Recombinant Proteins / Q000494:pharmacology; D019061:src-Family Kinases / Q000096:biosynthesis
chemical_list: C108123:4-amino-5-(4-methylphenyl)-7-(tert-butyl)pyrazolo(3,4-d)pyrimidine; D020747:Calcium Channels, T-Type; D008263:Macrophage Migration-Inhibitory Factors; D011720:Pyrazoles; D011743:Pyrimidines; D011994:Recombinant Proteins; D019833:Genistein; D011505:Protein-Tyrosine Kinases; D000081247:CSK Tyrosine-Protein Kinase; D019061:src-Family Kinases; C000631346:CSK protein, human; D019746:Intramolecular Oxidoreductases; C076231:Mif protein, mouse