Effect of tropisetron on pyroptosis in cardiomyocytes subjected to hypoxia-reoxygenation: relationship with α7nAchR / 中华麻醉学杂志

ABSTRACT

Objective:To evaluate the effect of tropisetron on pyroptosis in cardiomyocytes subjected to hypoxia-reoxygenation (H/R) and the relationship with α7 nicotinic acetylcholine receptor (α7nAChR).Methods:Routinely cultured H9C2 cardiomyocytes were divided into 4 groups ( n=6 each) using a random number table method: control group (C group), H/R group, tropisetron plus H/R group (Tro+ H/R group), and α7nAchR antagonist MLA plus tropisetron plus H/R group (MLA+ Tro+ H/R group). H/R was produced by 12 h exposure of cells to hypoxia followed by 6 h reoxygenation in the other three groups except group C. Tropisetron at the final concentration of 10 nmol/L was added at 1 h before hypoxia in group Tro+ H/R.In group MLA+ Tro+ H/R, MLA was added at 2 h before hypoxia, and then 1 h later tropisetron at the final concentration of 10 nmol/L was given.At 6 h of reoxygenation, the pyroptosis rate of cardiomyocytes was determined by fluorescence immunostaining of caspase-1-AlexaFluor 488/DAPI, the concentrations of interleukin-1beta (IL-1β) and IL-18 in the supernatant were determined by enzyme-linked immunosorbent assay, the activity of LDH in the supernatant was measured by 2, 4 dinitrophenylhydra-zine colorimetric method, and the expression of α7nAchR, NLRP3 and caspase-1 in cardiomyocytes was detected by Western blot. Results:Compared with group C, the pyroptosis rate, activity of LDH and concentrations of IL-1β and IL-18 in the supernatant were significantly increased, the expression of NLRP3 and caspase-1 was up-regulated, and the expression of α7nAchR was down-regulated in group H/R ( P<0.05). Compared with group H/R, the pyroptosis rate, activity of LDH and concentrations of IL-1β and IL-18 in the supernatant were significantly decreased, the expression of NLRP3 and caspase-1 was down-regulated, and the expression of α7nAchR was up-regulated in group Tro+ H/R ( P<0.05). Compared with group Tro+ H/R, the pyroptosis rate, activity of LDH and concentrations of IL-1β and IL-18 in the supernatant were significantly increased, the expression of NLRP3 and caspase-1 was up-regulated, and the expression of α7nAchR was down-regulated in group MLA+ Tro+ H/R ( P<0.05). Conclusion:α7nAchR is involved in the process of tropisetron inhibiting pyroptosis in cardiomyocytes subjected to H/R.