Effects of tumor necrosis factor alpha on expression of phospholamban and intracellular calcium in cardiomyocytes.
- Author:
Yu-mei YAO
1
;
Shen-jiang HU
;
Yuan-wei HUANG
;
Chun-hu YANG
;
Jian SUN
;
Zhao-hui ZHU
;
Tao WU
Author Information
- Publication Type:Journal Article
- MeSH: Animals; Calcium; metabolism; Calcium-Binding Proteins; biosynthesis; genetics; Cells, Cultured; Female; Male; Myocytes, Cardiac; drug effects; metabolism; RNA, Messenger; genetics; Rats; Rats, Wistar; Sarcoplasmic Reticulum Calcium-Transporting ATPases; biosynthesis; genetics; Tumor Necrosis Factor-alpha; pharmacology
- From: Acta Academiae Medicinae Sinicae 2005;27(6):767-771
- CountryChina
- Language:Chinese
-
Abstract:
OBJECTIVETo explore the effects of tumor necrosis factor alpha (TNFalpha) on the expression of phospholamban (PLB) and sarco (endo) plasmic reticulum Ca(2+)-ATPase (SERCA2a) and concentration of intracellular free calcium in myocardiocytes.
METHODSThe neonatal rat myocardiocytes were randomly divided into 6 groups: treatment with different concentrations of TNFalpha (1,10,30,50,and 70 microg/L, respectively) and without TNFalpha (control). The mRNA and protein expression of PLB and SERCA2a were detected with one-step reverse transcription-polymerase chain reaction and Western blotting. The changes of intracellular free calcium concentration ([Ca2+]i) in cultured single neonatal rat cardiomyocyte were determined with Fluo-3/AM loading by laser scanning confocal microscopy. RESULTS TNFalpha significantly increased the expression of PLB mRNA and protein in a dose-dependent fashion. The ratio of PLB/beta-actin mRNA in myocardiocytes incubated with 10,30,50, and 70 microg/L TNFalpha significantly increased by 66%, 106%, 141%, and 189% compared with control (P < 0.05), and protein levels significantly increased by 30%, 48%, 73%, and 114% respectively compared with control (P < 0.001), but there was no significant difference in PLB mRNA expression between the group treated with 1 microg/L TNFalpha and control group. TNFalpha had no effect on the expression of mRNA and protein of SERCA2a. TNFalpha (50 microg/L) incubated with cell for 24 hours diminished delta[Ca2+]i of single neonatal rat cardiomyocyte about 33% stimulated by isoproterenol (P < 0.01), but had no effect on delta [Ca2+]i of cardiomyocyte without isoproterenol stimulation.
CONCLUSIONTNFalpha can increase the expression of PLB and decrease delta[Ca2+]i in cardiomyocytes, which may be related with its negative inotropic effects on cardiomyocytes.