Significance of hydrogen sulfide in sepsis-induced myocardial injury in rats

Abstract

Sepsis-induced myocardial injury is a detrimental disorder for intensive care medicine due to its high rates of morbidity and mortality. Data suggest that nuclear factor (NF)-κB serves a critical role in the pathogenesis of myocardial injury. Hydrogen sulfide (H₂S) serves an important role in the physiology and pathophysiology of regulatory mechanisms, particularly during an inflammatory reaction. However, the relationship between NF-κB and H₂S in sepsis-induced myocardial injury is not well understood, and the underlying mechanisms remain unclear. In the present study, 60 male Sprague Dawley rats were randomly divided into the following six groups: A sham group, cecal ligation and puncture (CLP) group, sham + propargylglycine (PAG) group, CLP + PAG group, sham + sodium hydrosulfide (NaHS) group and CLP + NaHS group, with 10 rats in each group. The rats in all groups were sacrificed 12 h after surgery for sample collection. Compared with the sham group, it was observed that the concentrations of Creatine Kinase-MB (CK-MB) and cardiac troponin I (cTnI) in the serum, and pathological scores of myocardial tissue were significantly increased in the CLP, CLP + NaHS and CLP + PAG groups (P<0.05). The pathological scores and concentrations of CK-MB and cTnI were significantly higher in the CLP + PAG group (P<0.05) and significantly lower in the CLP + NaHS group (P<0.05) when compared with the CLP group. The expression of cystathionine-γ-lyase (CSE) mRNA and content of interleukin (IL)-10 were significantly higher in the CLP group compared with the CLP + PAG group (P<0.05), while the expression of myocardial NF-κB and content of tumor necrosis factor (TNF)-α in the CLP group were significantly lowered compared with the CLP + PAG group (P<0.05). The expression of NF-κB and content of TNF-α were significantly increased in the CLP group when compared with the CLP + NaHS group (P<0.05), while the content of myocardial IL-10 in the CLP group was significantly lower than in the CLP + NaHS group (P<0.05). In conclusion, H₂S acted as an anti-inflammatory cytokine and biomarker in sepsis-induced myocardial injury. Furthermore, H₂S may downregulate the NF-κB subunit p65 to mediate inflammatory responses. The present data suggest that myocardial injury in sepsis may be relieved through the regulation of H₂S expression, and provide an experimental basis for the treatment of sepsis patients presenting with myocardial injury. In addition, myocardial injury in sepsis may be identified by monitoring changes in the expression of H₂S.

Keywords: hydrogen sulfide; myocardial injury; nuclear factor-κB; sepsis; tumor necrosis factor-α.

Figure 1.

Examination of myocardial tissue pathology by hematoxylin and eosin staining. (A) Sham group, in which rats underwent a laparotomy; (B) sham + NaHS group, in which sham rats were treated with 8.9 µmol/kg NaHS 1 h after laparotomy; (C) sham + PAG group, in which sham rats were treated with 50 mg/kg PAG 1 h after laparotomy; (D) CLP group, in which rats underwent CLP; (E) CLP + NaHS group, in which CLP rats were treated with 8.9 µmol/kg NaHS 1 h after CLP; (F) CLP + PAG group, in which CLP rats were treated with 50 mg/kg PAG 1 h after CLP. Magnification, ×200. CLP, cecal ligation and puncture; NaHS, sodium hydrosulfide; PAG, propargylglycine.

Figure 2.

Change in the serum levels of (A) CK-MB and (B) cTnI in sepsis rats. Data are presented as the mean ± standard error of the mean. *P<0.05 vs. sham group; ^#P<0.05 vs. CLP group. CK-MB, Creatine Kinase-MB; cTnI, cardiac troponin I; CLP, cecal ligation and puncture; NaHS, sodium hydrosulfide; PAG, propargylglycine.

Figure. 3.

Change in the myocardial tissue levels of (A) TNF-α and (B) IL-10 in sepsis rats. Data are presented as the mean ± standard error of the mean. *P<0.05 vs. sham group; ^#P<0.05 vs. CLP group. TNF, tumor necrosis factor; IL, interleukin; CLP, cecal ligation and puncture; NaHS, sodium hydrosulfide; PAG, propargylglycine.

Figure 4.

Analysis of CSE mRNA expression in the myocardial tissue of sepsis rats by reverse transcription-polymerase chain reaction. Lanes a, b, c and d show results of the sham, sham + PAG, CLP + PAG and CLP groups, respectively. *P<0.05 vs. sham group; ^#P<0.05 vs. CLP + PAG group. CSE, cystathionine-γ-lyase; CLP, cecal ligation and puncture; PAG, propargylglycine.

Figure 5.

Change in the expression of NF-κB p65 in the myocardial tissue of sepsis rats following treatment with PAG. Lanes a, b, c and d show results of the sham, sham + PAG, CLP + PAG and CLP groups, respectively.*P<0.05 vs. sham group; ^#P<0.05 vs. CLP + PAG group. NF-κB, nuclear factor-κB; CLP, cecal ligation and puncture; PAG, propargylglycine.

Figure 6.

Change in the expression of NF-κB p65 in the myocardial tissue of sepsis rats following treatment with NaHS. Lanes a, b, c and d show results of the sham, sham + NaHS, CLP + NaHS and CLP groups, respectively. *P<0.05 vs. sham group; ^#P<0.05 vs. CLP + NaHS group. NF-κB, nuclear factor-κB; CLP, cecal ligation and puncture; NaHS, sodium hydrosulfide.