OBJECTIVETo examine the effect of H2S donor, sodium hydrosulfide (NaHS), on ET-1 level in plasma and aorta in rats with atherosclerosis (AS).

METHODThirty male rats, weighting 200-220 g, were randomly divided into AS, AS+NaHS and control groups, n = 10 in each group.Rats were given a single dose of vitamin D3 (700 000 U/kg) in the first three days and fed with a high-cholesterol diet for 8 weeks to induce AS. Rats in AS+NaHS group were intraperitoneally injected with an H2S donor NaHS, at a dose of 56 µmol/(kg·d) for 8 weeks. At the end of the experiment for 8 weeks, all the rats were sacrificed. The plasma was collected and the aorta and coronary tissues were isolated. The atherosclerotic lesions in both aorta and coronary arteries were detected using oil red O method. H2S concentration in plasma was determined with sulfide-sensitive electrode method. ET-1 levels in plasma and aorta were calculated by radioimmunoassay kit and the localization of ET-1 in the aorta was detected by immunohistochemistry. Plasma nitric oxide synthase (NOS), endothelial NOS (eNOS), inducible NOS (iNOS) were detected with colorimetry.

RESULTAS plaque area in root of aorta of rats in AS group, AS+NaHS group and control group were (11.6±3.3)%, (1.6±1.1)%, (0.0±0.1)% respectively. The difference in AS plaque area in root of aorta among the three groups was statistically significant (F=97.675, P < 0.05). AS plaque area in coronary artery of rats in AS group, AS+NaHS group and control group were (21.4±5.7)%, (4.8±2.5)%, (0.0±0.0)% respectively. The difference in AS plaque area in coronary artery among the three groups was statistically significant (F=97.519, P < 0.05). Plasma H2S level in rats of AS group ((22.0±3.1) µmol/L) was significantly lower than that of control group ((27.9±1.0) µmol/L) and AS+NaHS group ((33.3±6.2) µmol/L, all P < 0.05). Compared with control group ((70.0±10.7) ng/L), plasma ET-1 in rats of AS group ((89.6±14.2) ng/L) and AS+NaHS group ((93.1±15.5) ng/L, P both < 0.05) were increased. However, there was no significant difference in plasma ET-1 content in rats between AS+NaHS group and AS group (P > 0.05). Compared with control group ((3.8±1.2) ng/g), ET-1 content in aorta in rats of AS group ((11.9±4.9) ng/g) and AS+NaHS group ((8.2±2.5) ng/g, both P < 0.05) were increased, and ET-1 content in aorta in rats of AS+NaHS group was decreased compared with AS group (P < 0.05). Immunochemistry results showed that ET expression in cytoplasm in aortic endothelial cells in rats of AS group was strengthened, while ET expression in rats of control group and AS+NaHS group was weak. NOS activity of rats in control group, AS group and AS+NaHS group was (25.4±5.6), (51.8±10.0) and (27.6±6.5) U/ml, eNOS activity (15.3±6.2), (4.5±2.7) and (8.7±3.9) U/ml, and iNOS activity (9.9±4.0), (47.3±10.7) and (19.0±5.2) U/ml, respectively.Differences among the three groups were statistically significant (NOS activity: F=37.231, P < 0.05, eNOS activity: F=14.600, P < 0.05, and iNOS activity: F=72.131, P < 0.05).

CONCLUSIONH2S donor NaHS reduced the AS plaque in AS rats. The mechanisms might involve the protective effect of H2S on the vascular endothelial cell, decreasing ET-1 production in aortal endothelium of atherosclerotic rats.

Animals ; Aorta ; metabolism ; pathology ; Atherosclerosis ; metabolism ; pathology ; Coronary Vessels ; pathology ; Disease Models, Animal ; Endothelin-1 ; blood ; metabolism ; Hydrogen Sulfide ; pharmacology ; Male ; Nitric Oxide Synthase Type II ; metabolism ; Nitric Oxide Synthase Type III ; metabolism ; Random Allocation ; Rats ; Sulfides ; pharmacology

BACKGROUNDAcute lymphoblastic leukemia (ALL) and chemotherapy can cause immune imbalance, and gaseous molecule hydrogen sulfide (H2S) can participate in the process of immune response. This study aimed to investigate the immune regulation of H2S in pediatric ALL.

METHODSChildren (n = 78) with ALL admitted during 2010-2013 were included in this study. Two blood samples were collected in period of before chemotherapy, bone marrow remission and two days after chemotherapy, respectively. Serum contents of H2S and cytokines, including interleukin-1β (IL-1β), interleukin-2 (IL-2), interferon-γ (IFN-γ), tumor necrosis factor (TNF-α), interleukin-4 (IL-4), interleukin-6 (IL-6), interleukin-10 (IL-10) and macrophage inflammatory protein-1α (MIP-1α), were detected using ELISA method. Stepwise regression was used to analyze the correlation between H2S and cytokines. Furthermore, human Jurkat cells were cultured in vitro, and nucleoprotein of Jurkat cells and peripheral blood mononuclear cells (PBMCs) were collected, contents of cystathionine γ-lyase (CSE) and certain cytokines were measured by Western blotting.

RESULTSSerum concentrations of H2S, IL-1β, IL-6, IL-10 and MIP-1a in children with ALL were increased significantly (P < 0.01), while concentrations of IL-2, TNF-α, IFN-γ and IL-4 decreased obviously (P < 0.01). In patients after chemotherapy, concentrations of H2S and IL-10 were decreased significantly (P < 0.05), but IL-4 and IFN-γ concentrations increased markedly (P < 0.05). At remission stage, H2S, IL-1β, IL-4, IL-6, IL-10 and MIP-1α concentrations were further decreased markedly (P < 0.05), but concentrations of IL-2, TNF-α and IFN-γ increased again (P < 0.05). Protein contents of CSE, IL-10, IL-4 and IL-2 of PBMCs also increased markedly in children with ALL. Moreover, changes of CSE protein contents of PBMCs were consistent with serum H2S contents, and there were significant correlation between H2S and certain cytokines based on stepwise regression analysis. Furthermore, compared with those of PBMCs group, in vitro study indicated that Jurkat cells of H2S group expressed IFN-γ, IL-10, IL-4 and IL-2 protein increased obviously (P < 0.05), while IL-4, IL-2 and CSE expression of PPG group decreased markedly (P < 0.05).

CONCLUSIONGaseous molecule H2S might participate in the process of immune regulation in pediatric ALL through modulating transcription and expression of cytokines.

Child ; Child, Preschool ; Cystathionine gamma-Lyase ; blood ; Female ; Humans ; Hydrogen Sulfide ; blood ; Interferon-gamma ; blood ; Interleukin-10 ; blood ; Interleukin-1beta ; blood ; Interleukin-2 ; blood ; Interleukin-4 ; blood ; Interleukin-6 ; blood ; Leukocytes, Mononuclear ; metabolism ; Male ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; blood ; Tumor Necrosis Factor-alpha ; blood