Objective We cultured neonatal SD rat cardiomyocytes, treated then with solvents or drug (curcumin), anti-LOX-1 antibody, and then stimulated with AngII. We observed the difference of the mRNA expression of Lectin-like oxidised low density lipoprotein receptor 1 (LOX-1) among the four groups. We aim to establish the effects of curcumin on the mRNA expression of LOX-1 in cardiomyocytes cultured cells, and further investigate this effect of protecting and delaying some myocardial diseases.
Methods The experiment was accomplished between 2010/3–2010/9 in the animal operating room of Anhui Medical Univeisity, and the center laboratory of the First Affiliated Hospital of Anhui Medical University. (1) Neonatal SD rat6-10 (1–2 days), the hearts were extracted, neonatal rat heart tissue was digested 4 to 5 times, and then cultured with DMEM/F12 including 10% BSA. (2) The cardiomyocytes were cultured for 48 h in DMEM/F12 including 10% BSA, and then changed the culture medium to DMEM/F12 without BSA, cultured for 24 h. (3) The cultured cardiomyocytes were divided into four groups: group 1, the negative control group; group 2, the Positive control group (treated with AngII), group 3, the AngII+anti-LOX-1 antibody group, group 4, the AngII+curcumin group. (4) We cultured samples with DMEM/F12 without BSA for 24 h, changed the third group's culture medium to DMEM/F12 including 10 μg/ml anti-LOX-1 antibody and the fourth group's culture medium to DMEM/F12 including 5 μmol/l curcumin for 3 h. Then changed the second, third, fourth group's culture medium to DMEM/F12 including 0.1 μmol/l AngII, cultured for another 24 h. (5) We collected the total RNA of the cultured cardiomyocytes with Trizol, used RT-PCR to detect the mRNA expression of LOX-1 in four groups. The results were treated with gel-imaging system.
Results (1) This experiment was repeated for three times, the cultured cardiomyocytes grew well. The survived cardiomyocytes were assessed by 0.4% typsin, the survival rates between 95 to 97%, 70 to 80% beating cardiomyocytes were observed and the beating frequency of cells was 8 to 70 beats/min. In the area which the cardiomyocytes density was higher, the beating frequency was between 30 to 70 beats/min. (2) LOX-1 mRNA expression induced by angiotensin II was significantly upregulated in comparison with the negative control group (p<0.05). (3) Pretreatment of cells with curcumin reduced the increase of LOX-1 mRNA expression treated with Ang II (p<0.05), and the expression was not significantly different from the cells pretreated with anti-LOX-1 antibody (p>0.05).
Conclusion Curcumin may lead to anti-oxidation and change the ventricular remodeling by down-regulating the mRNA expression of LOX-1 induced by Ang II.