Strategies for the Design of Donors and Precursors of Reactive Sulfur Species.

Reactive sulfur species (RSS) play regulatory roles in biological systems. Many RSS are highly reactive and transient molecules, making their study difficult. RSS donors or precursors, which are used to specifically produce or deliver RSS, are useful research tools, as well as possible therapeutic agents. In this Minireview, we summarized the chemical strategies that have been used in the design of donors/precursors of hydrogen sulfide relevant RSS (including hydrogen sulfide, hydrogen polysulfides, persulfides, and S-nitroso-hydrogen sulfide). The potential problems of applying these strategies in biological settings are also discussed.

Three new diterpenoids from Aralia dumetorum.

Three new diterpenoids, dumetoranes A (1) and B (2), melanocane B (3), together with four known ones including melanocane A (4), ent-15S,16-dihydroxypimar-8(14)-en-19-oic acid (5), ent-pimara-8(14),15-diene-19-oic acid (6), and ent-pimara-8(14),15-diene-19-ol (7) were obtained from the ethanol extract of the roots of Aralia dumetorum. Their structure elucidation was achieved by the methods of spectroscopic HRMS, IR, NMR, and by comparison with literature. The cytotoxicities of compounds 1-3 and 5 were assayed by in vitro MTT methods.

Rational Design of a Dual-Reactivity-Based Fluorescent Probe for Visualizing Intracellular HSNO.

Thionitrous acid (HSNO), the smallest S-nitrosothiol, is emerging as a potential key intermediate in cellular redox regulation linking two signaling molecules H2 S and NO. However, the chemical biology of HSNO remains poorly understood. A major hurdle is the lack of methods for selective detection of HSNO in biological systems. Herein, we report the rational design, synthesis, and evaluation of the first fluorescent probe TAP-1 for HSNO detection. TAP-1 showed high selectivity and sensitivity to HSNO in aqueous media and cells, providing a useful tool for understanding the functions of HSNO in biology.

Data-Driven Identification of Hydrogen Sulfide Scavengers.

Hydrogen sulfide (H2 S) is an important signaling molecule whose up- and down-regulation have specific biological consequences. Although significant advances in H2 S up-regulation, by the development of H2 S donors, have been achieved in recent years, precise H2 S down-regulation is still challenging. The lack of potent/specific inhibitors for H2 S-producing enzymes contributes to this problem. We expect the development of H2 S scavengers is an alternative approach to address this problem. Since chemical sensors and scavengers of H2 S share the same criteria, we constructed a H2 S sensor database, which summarizes key parameters of reported sensors. Data-driven analysis led to the selection of 30 potential compounds. Further evaluation of these compounds identified a group of promising scavengers, based on the sulfonyl azide template. The efficiency of these scavengers in in vitro and in vivo experiments was demonstrated.

TRPC6 contributes to LPS-induced inflammation through ERK1/2 and p38 pathways in bronchial epithelial cells.

receptor potential canonical (TRPC) channels are presently an emerging target for airway disorders. Recent evidence has indicated that TRPC6 as a member of the TRPC family plays an important role in airway inflammation, but its precise function in bronchial epithelial cells remains unclear. The aim of this study was to investigate the role of TRPC6 in Toll-like receptor 4 (TLR4)-mediated inflammation in human bronchial epithelial cells stimulated by endotoxin [lipopolysaccharide (LPS)]. Hyp9 is a simplified phloroglucinol derivative of hyperforin that highly selectively activates TRPC6 channels. The results show that the activation of TRPC6 by Hyp9 induced the production of interleukin (IL)-8 and IL-6. LPS was also able to induce the release of IL-8 and IL-6, which was significantly aggravated by Hyp9 and reduced by knockdown of TRPC6. Treatment with LPS not only chronically induced the expression of TRPC6 mRNA and protein in a TLR4-dependent manner but also acutely increased Ca2+ influx through TRPC6 channels. In addition, LPS-induced overexpression of TRPC6 and Ca2+ influx were associated with the phosphorylation of phosphatidylinositol 3-kinase (PI3K) and Akt. Importantly, TRPC6 was required for the activation of ERK1/2, p38, and NF-κB. In conclusion, these data reveal that LPS induced the overexpression of TRPC6 and TRPC6-dependent Ca2+ influx via the TLR4/PI3K/Akt pathway resulting in Ca2+ mobilization, which subsequently promoted the activation of ERK1/2, p38, and NF-κB and the inflammatory response in bronchial epithelial cells.

A novel pH-controlled hydrogen sulfide donor protects gastric mucosa from aspirin-induced injury.

Hydrogen sulphide (H2 S) serves as a vital gastric mucosal defence under acid condition. Non-steroidal anti-inflammatory drugs (NSAIDs) are among widely prescribed medications with effects of antipyresis, analgesia and anti-inflammation. However, their inappropriate use causes gastric lesions and endogenous H2 S deficiency. In this work, we reported the roles of a novel pH-controlled H2 S donor (JK-1) in NSAID-related gastric lesions. We found that JK-1 could release H2 S under mild acidic pH and increase solution pH value. Intragastrical administration of aspirin (ASP), one of NSAIDs, to mice elicited significant gastric lesions, evidenced by mucosal festering and bleeding. It also led to infiltration of inflammatory cells and resultant releases of IL-6 and TNF-α, as well as oxidative injury including myeloperoxidase (MPO) induction and GSH depletion. In addition, the ASP administration statistically inhibited H2 S generation in gastric mucosa, while up-regulated cyclooxygenase (COX)-2 and cystathionine gamma lyase (CSE) expression. Importantly, these adverse effects of ASP were prevented by the intragastrical pre-administration of JK-1. However, JK-1 alone did not markedly alter the property of mouse stomachs. Furthermore, in vitro cellular experiments showed the exposure of gastric mucosal epithelial (GES-1) cells to HClO, imitating MPO-driven oxidative injury, decreased cell viability, increased apoptotic rate and damaged mitochondrial membrane potential, which were reversed by pre-treatment with JK-1. In conclusion, JK-1 was proved to be an acid-sensitive H2 S donor and could attenuate ASP-related gastric lesions through reconstruction of endogenous gastric defence. This work indicates the possible treatment of adverse effects of NSAIDs with pH-controlled H2 S donors in the future.

Inhibition of Methylglyoxal-Induced AGEs/RAGE Expression Contributes to Dermal Protection by N-Acetyl-L-Cysteine.

BACKGROUND/AIM: Accumulation of advanced glycation end products (AGEs) is a major cause of diabetes mellitus (DM) skin complications. Methylglyoxal (MGO), a reactive dicarbonyl compound, is a crucial intermediate of AGEs generation. N-acetyl-L-cysteine (NAC), an active ingredient of some medicines, can induce endogenous GSH and hydrogen sulfide generation, and set off a condensation reaction with MGO. However, there is rare evidence to show NAC can alleviate DM-induced skin injury through inhibition of AGEs generation or toxicity. The present study aimed to observe the effects of NAC on MGO-induced inflammatory injury and investigate the roles of AGEs and its receptor (RAGE) in NAC's dermal protection in human HaCaT keratinocytes. METHODS: The cells were exposed to MGO to simulate a high MGO status in diabetic blood or tissues. The content of AGEs in serum or cell medium was measured with ELISA. The protective effects of NAC against MGO-induce injury were evaluated by administration before MGO one hour, in virtue of cell viability, mitochondrial membrane potential, inflammation reaction, nuclear factor (NF)-κB activation, matrix metalloproteinase (MMP)-9 expression, as well as cellular behavioral function. RESULTS: We found the AGEs levels of patients with DM were elevated comparing with healthy volunteers. The in vitro AGEs generation was also able to be enhanced by the exposure of HaCaT cells to MGO, which reduced dose-dependently cellular viability, damaged mitochondrial function, triggered secretion of interleukin (IL)-6 and IL-8, activated NF-κB and upregulated MMP-9 expression. Furthermore, the exposure caused cellular adhesion and migration dysfunction, as well as collagen type I inhibition. Importantly, before the exposure to MGO, the preconditioning with NAC significantly attenuated MGO-induced AGEs generation, improved cellular viability and mitochondrial function, partially reversed the overexpression of proinflammatory factors and MMP-9, as well as the activation of NF-κB. Lastly, NAC blocked MGO-induced RAGE upregulation, and inhibition of RAGE with its neutralizing antibody significantly alleviated MGO-induced NF-κB activation, MMP-9 upregulation and inflammatory injury in HaCaT cells. CONCLUSION: The present work indicates the administration of NAC can prevent MGO-induced dermal inflammatory injury through inhibition of AGEs/RAGE signal, which may provide a basal support for the treatment of diabetic skin complications with NAC-containing medicines in the future.

pH-Controlled Hydrogen Sulfide Release for Myocardial Ischemia-Reperfusion Injury.

Hydrogen sulfide (H2S) is a critical signaling molecule that regulates many physiological and/or pathological processes. Modulation of H2S levels could have potential therapeutic value. In this work, we report the rational design, synthesis, and biological evaluation of a class of phosphonamidothioate-based H2S-releasing agents (i.e., H2S donors). A novel pH-dependent intramolecular cyclization was employed to promote H2S release from the donors. These water-soluble compounds showed slow, controllable, and pH-sensitive production of H2S in aqueous solutions. The donors also showed significant cytoprotective effects in cellular models of oxidative damage. Most importantly, the donors were found to exhibit potent cardioprotective effects in an in vivo murine model of myocardial ischemia-reperfusion (MI/R) injury through a H2S-related mechanism.

Ammonium tetrathiomolybdate as a water-soluble and slow-release hydrogen sulfide donor.

Ammonium tetrathiomolybdate (TTM) was found to be a slow hydrogen sulfide (H2S) releasing agent. Its H2S generation capability in aqueous solutions was confirmed by UV-vis and fluorescence assays. TTM also showed H2S-like cytoprotective effects in hydrogen peroxide (H2O2)-induced oxidative damage in HaCaT cells.

Cytotoxic Diterpenoids from the Roots of Aralia melanocarpa.

Five new diterpenoids (1-5) were isolated from the roots of Aralia melanocarpa, together with four known compounds, 7ß-hydroxy-ent-pimara-8(14),15-diene-19-oic acid (6), 18-norpimara-8(14),15-dien-4-ol (7), ent-16ßH,17-isovalerate-kauran-19-oic acid (8), and ent-16α,17-dihydroxykauran-19-oic acid (9). Based on the MS, IR, and NMR spectral analysis, the structures of the five new diterpenoids (1-5) were elucidated. The cytotoxic activities of compounds 1-9 were assayed, and compounds 1 and 2 showed cytotoxicity in four cancer cell lines with IC50s from 4.2 to 8.2 µM.

[N-acetyl-L-cysteine reduces the ozone-induced lung inflammation response in mice].

In this study, we investigated the protective effect of the antioxidant N-acetyl-L-cysteine (NAC) on the lung inflammation caused by ozone (O3) exposure in mice. Thirty-two C57BL/6 mice were randomly divided into control group, O3 group, O3+NAC group and NAC group. Mice were exposed to O3 (1.0 ppm) or fresh air for 3 h on the day 1, day 3 and day 5, respectively. NAC (100 mg/kg) was intraperitoneally applied to the mice 1 h before each exposure. At 24 h after the 3-time exposure, the alveolar wall structure was severely damaged and the infiltrated inflammatory cells were apparent perivascularly and peribronchiolarly. Significant increases in the total white blood cell count, macrophage, lymphocyte and neutrophil counts, as well as total protein concentration were observed in the bronchoalveolar lavage fluid (BALF) (P < 0.05). The IL-6, IL-8 (P < 0.01) and MDA levels (P < 0.05) in the lung homogenates were elevated coherently. Administration of NAC could attenuate the alveolar wall structure damage induced by O3 exposure and reduce the amount of infiltrated inflammatory cells, total and differential leukocyte counts (P < 0.05), as well as the IL-6, IL-8 (P < 0.01) and MDA release (P < 0.05). Western blotting results showed that the O3 exposure up-regulated the p38 MAPK and NF-κB p65 protein expression in the lung tissue of mice (P < 0.05), which could be alleviated by NAC (P < 0.05). These results indicated that NAC could protect against O3-induced pulmonary inflammation in mice. The beneficial effect of NAC might be related with the p38 MAPK and NF-κB p65 signal pathway.

A novel controllable hydrogen sulfide-releasing molecule protects human skin keratinocytes against methylglyoxal-induced injury and dysfunction.

BACKGROUND/AIM: Delayed wound healing is a common skin complication of diabetes, which is associated with keratinocyte injury and dysfunction. Levels of methylglyoxal (MGO), an α-dicarbonyl compound, are elevated in diabetic skin tissue and plasma, while levels of hydrogen sulfide (H2S), a critical gaseous signaling molecule, are reduced. Interestingly, the gas has shown dermal protection in our previous study. To date, there is no evidence demonstrating whether MGO affects keratinocyte viability and function or H2S donation abolishes these effects and improves MGO-related impairment of wound healing. The current study was conducted to examine the effects of MGO on the injury and function in human skin keratinocytes and then to evaluate the protective action of a novel H2S-releasing molecule. METHODS: An N-mercapto-based H2S donor (NSHD)-1 was synthesized and its ability to release H2S was observed in cell medium and cells, respectively. HaCaT cells, a cell line of human skin keratinocyte, were exposed to MGO to establish an in vitro diabetic wound healing model. NSHD-1 was added to the cells before MGO exposure and the improvement of cell function was observed in respect of cellular viability, apoptosis, oxidative stress, mitochondrial membrane potential (MMP) and behavioral function. RESULTS: Treatment with MGO decreased cell viability, induced cellular apoptosis, increased intracellular reactive oxygen species (ROS) content and depressed MMP in HaCaT cells. The treatment also damaged cell behavioral function, characterized by decreased cellular adhesion and migration. The synthesized H2S-releasing molecule, NSHD-1, was able to increase H2S levels in both cell medium and cells. Importantly, pretreatment with NSHD-1 inhibited MGO-induced decreases in cell viability and MMP, increases in apoptosis and ROS accumulation in HaCaT cells. The pretreatment was also able to improve adhesion and migration function. CONCLUSION: These results demonstrate that the novel synthesized H2S donor is able to protect human skin keratinocytes against MGO-induced injury and behavior dysfunction. We believe that more reasonable H2S-releasing molecules will bring relief to patients suffering from delayed wound healing in diabetes mellitus in the future.

New clerodane diterpenes from Tinospora sagittata var. yunnanensis.

Four new clerodane diterpenes, namely sagittatayunnanosides A-D (1-4), were isolated from the roots of Tinospora sagittata var. yunnanensis, together with two known compounds, tinospinoside C (5) and tinospinoside E (6). The structures of the four new compounds were well elucidated by extensive analyses of the MS, IR, and 1D and 2D NMR data. The cytotoxic and antifouling activities of compounds 1-6 were evaluated.

Inhibition of ROS-activated ERK1/2 pathway contributes to the protection of H2S against chemical hypoxia-induced injury in H9c2 cells.

Hydrogen sulfide (H(2)S) has been shown to exert cardioprotective effects. However, the roles of extracellular signal-regulated protein kinases 1/2 (ERK1/2) in H(2)S-induced cardioprotection have not been completely elucidated. In this study, cobalt chloride (CoCl(2)), a chemical hypoxia mimetic agent, was applied to treat H9c2 cells to establish a chemical hypoxia-induced cardiomyocyte injury model. The results showed that pretreatment with NaHS (a donor of H(2)S) before exposure to CoCl(2) attenuated the decreased cell viability, the increased apoptosis rate, the loss of mitochondrial membrane potential (ΔΨm), and the intracellular accumulation of reactive oxygen species (ROS) in H9c2 cells. Exposure of H9c2 cells to CoCl(2) or hydrogen peroxide (H(2)O(2)) upregulated expression of phosphorylated (p) ERK1/2, which was reduced by pretreatment with NaHS or N-acetyl-L-cysteine, a ROS scavenger. More importantly, U0126, a selective inhibitor of ERK1/2, mimicked the above cytoprotection of H(2)S against CoCl(2)-induced injury in H9c2 cells. In conclusion, these results indicate that H(2)S protects H9c2 cells against chemical hypoxia-induced injury partially by inhibiting ROS-mediated activation of ERK1/2.

Hydrogen sulfide protects H9c2 cells against doxorubicin-induced cardiotoxicity through inhibition of endoplasmic reticulum stress.

The roles of hydrogen sulfide (H(2)S) and endoplasmic reticulum (ER) stress in doxorubicin (DOX)-induced cardiotoxicity are still unclear. This study aimed to dissect the hypothesis that H(2)S could protect H9c2 cells against DOX-induced cardiotoxicity by inhibiting ER stress. Our results showed that exposure of H9c2 cells to DOX significantly inhibited the expression and activity of cystathionine-γ-lyase (CSE), a synthetase of H(2)S, accompanied by the decreased cell viability and the increased reactive oxygen species (ROS) accumulation. In addition, exposure of cells to H(2)O(2) (an exogenous ROS) mimicked the inhibitory effect of DOX on the expression and activity of CSE. Pretreatment with N-acetyl-L: -cysteine (NAC) (a ROS scavenger) attenuated intracellular ROS accumulation, cytotoxicity, and the inhibition of expression and activity of CSE induced by DOX. Notably, the ER stress-related proteins, including glucose-regulated protein 78 (GRP78) and C/EBP homologous protein (CHOP) were obviously upregulated in DOX-treated H9c2 cells. Pretreatment with sodium hydrosulfide (NaHS, a H(2)S donor) before DOX exposure markedly suppressed DOX-induced overexpressions of GRP78 and CHOP, cytotoxicity and oxidative stress. In conclusion, we have demonstrated that ROS-mediated inhibition of CSE is involved in DOX-induced cytotoxicity in H9c2 cells, and that exogenous H(2)S can confer protection against DOX-induced cardiotoxicity partly through inhibition of ER stress.

Multiplayer Noncooperative and Cooperative Minimax H∞ Tracking Game Strategies for Linear Mean-Field Stochastic Systems With Applications to Cyber-Social Systems.

The multiplayer stochastic noncooperative tracking game (NTG) with conflicting target strategy and cooperative tracking game (CTG) with a common target strategy of the mean-field stochastic jump-diffusion (MFSJD) system with external disturbance is investigated in this study. Due to the mean (collective) behavior in the system dynamic and cost function, the designs of the NTG strategy and CTG strategy for target tracking of the MFSJD system are more difficult than the conventional stochastic system. By the proposed indirect method, the NTG and CTG strategy design problems are transformed into linear matrix inequalities (LMIs)-constrained multiobjective optimization problem (MOP) and LMIs-constrained single-objective optimization problem (SOP), respectively. The LMIs-constrained MOP could be solved effectively for all Nash equilibrium solutions of NTG at the Pareto front by the proposed LMIs-constrained multiobjective evolutionary algorithm (MOEA). Two simulation examples, including the share market allocation and network security strategies in cyber-social systems, are given to illustrate the design procedure and validate the effectiveness of the proposed LMI-constrained MOEA for all Nash equilibrium solutions of NTG strategies of the MFSJD system.

Deficient DNASE1L3 facilitates neutrophil extracellular traps-induced invasion via cyclic GMP-AMP synthase and the non-canonical NF-κB pathway in diabetic hepatocellular carcinoma.

Objective: Diabetic hepatocellular carcinoma (HCC) patients have high mortality and metastasis rates. Diabetic conditions promote neutrophil extracellular traps (NETs) generation, which mediates HCC metastasis and invasion. However, whether and how diabetes-induced NETs trigger HCC invasion is largely unknown. Here, we aimed to observe the effects of diabetes-induced NETs on HCC invasion and investigate mechanisms relevant to a DNA sensor cyclic GMP-AMP synthase (cGAS). Methods: Serum from diabetic patients and healthy individuals was collected. Human neutrophil-derived NETs were isolated for stimulating HCC cell invasion. Data from the SEER and TCGA databases were used for bioinformatics analysis. In HCC cells and allograft models, NETs-triggered invasion was observed. Results: Diabetic HCC patients had poorer survival than non-diabetic ones. Either diabetic serum or extracted NETs caused HCC invasion. Induction of diabetes or NETosis elicited HCC allograft invasion in nude mice. HCC cell invasion was attenuated by the treatment with DNase1. In TCGA_LIHC, an extracellular DNase DNASE1L3 was downregulated in tumor tissues, while function terms (the endocytic vesicle membrane, the NF-κB pathway and extracellular matrix disassembly) were enriched. DNASE1L3 knockdown in LO2 hepatocytes or H22 cell-derived allografts facilitated HCC invasion in NETotic or diabetic nude mice. Moreover, exposure of HCC cells to NETs upregulated cGAS and the non-canonical NF-κB pathway and induced expression of metastasis genes (MMP9 and SPP1). Both cGAS inhibitor and NF-κB RELB knockdown diminished HCC invasion caused by NETs DNA. Also, cGAS inhibitor was able to retard translocation of NF-κB RELB. Conclusion: Defective DNASE1L3 aggravates NETs DNA-triggered HCC invasion on diabetic conditions via cGAS and the non-canonical NF-κB pathway.

Heat shock protein 90 mediates cytoprotection by H2S against chemical hypoxia-induced injury in PC12 cells.

1. Increasing evidence indicates that hydrogen sulphide (H2S) may serve as an important biological cytoprotective agent. Heat shock protein (Hsp) 90 can attenuate stress-induced injury. However, whether Hsp90 mediates the cytoprotective effect of H2S against chemical hypoxia-induced injury in PC12 cells is not known. 2. In the present study, CoCl2 (a chemical hypoxia mimetic) was used to treat PC12 cells to create a model of chemical hypoxia. To explore the role of Hsp90 in the cytoprotection afforded by H2S against chemical hypoxia-induced injury, 2 µmol/L 17-allylaminogeldanamycin (17-AAG), a selective inhibitor of Hsp90, was administered for 30 min prior to preconditioning with 400 µmol/L NaHS, followed by chemical hypoxia. 3. Cobalt chloride reduced cell viability (by 52.7 ± 1.5%), increased PC12 cell apoptosis (by 42.1 ± 1.5%), induced reactive oxygen species (ROS) by 3.79% compared with control and induced the dissipation of mitochondrial membrane potential (MMP) by 2.56% compared with control. 4. Pretreatment of PC12 cells with 100-400 µmol/L sodium hydrosulphide (NaHS), an H2S donor, for 3 h prior to exposure to 600 µmol/L CoCl2 provided significant, concentration-dependant protection to PC12 cells against CoCl2-induced cytotoxicity. Specifically, pretreatment of PC12 cells with 400 µmol/L NaHS decreased apoptosis to 16.77 ± 1.77% and blocked the CoCl2-induced increase in ROS production and loss of MMP. 5. At 400 µmol/L, NaHS upregulated Hsp90 in a time-dependant manner (over the period 0-180 min). In addition to its effects on Hsp90 expression, NaHS pretreatment of PC12 cells augmented the overexpression of Hsp90 induced by 600 µmol/L CoCl2 by 1.38-fold (P < 0.01). 6. Treatment of PC12 cells with 2 µmol/L 17-AAG for 30 min prior to NaHS pretreatment blocked the overexpression of Hsp90 induced by NaHS preconditioning, as evidenced by decreased cell viability (by 54.2 + 1.2%; P < 0.01), increased PC12 cell apoptosis (by 36.6 ± 1.2%; P < 0.01) and increasing ROS production. 7. The findings of the present study provide novel evidence that Hsp90 mediates H2S-induced neuroprotection against chemical hypoxia-induced injury via anti-oxidant and anti-apoptotic effects.

Data Analysis-Driven Precise Asthmatic Treatment by Targeting Mast Cells.

BACKGROUND: Although the importance of mast cells in asthma has been studied, mast cellsinduced global changes in lungs are largely unknown. Data-driven identification contributes to discovering significant biomarkers or therapeutic targets, which are the basis of effective clinical medications. OBJECTIVE: This study aims to explore the effects of mast cells on gene expression in asthmatic lungs, and to assess the curative effects of inhaled budesonide (BUD). METHODS: Pulmonary gene expression in KitWsh mice with or without mast cell engraftment was analyzed with R software. Functional enrichment of Gene Ontology and KEGG was carried out through the DAVID online tool. Hub genes were identified with String and Cytoscape software. RESULTS: The array analyses showed that the mast cell engraftment enhanced inflammation/immune response, cytokine/chemokine signal, and monocyte/neutrophil/lymphocyte chemotaxis. Interleukin (IL)-6 was identified to be a significant hub gene with the highest interaction degree. Based on this, the effects of BUD were investigated on the aspects of anti-inflammation. BUD's treatment was found to reduce serum IL-6 content and pulmonary inflammation in ovalbumin-induced asthma rats. The treatment also downregulated beta-tryptase expression both in lung tissues and serum. Morphologically, the accumulation and degranulation of mast cells were significantly suppressed. Notably, the effects of BUD on inflammation and degranulation were comparable with Tranilast (a classic mast cell inhibitor), while a remarkable synergy was not observed. CONCLUSION: This study presented a unique pulmonary gene profile induced by mast cell engraftment, which could be reversed through blockage of mast cells or inhaled BUD.

Hydrogen sulphide protects H9c2 cells against chemical hypoxia-induced injury.

1. The aim of the present study was to investigate the effect of hydrogen sulphide (H(2)S) on cobalt chloride (CoCl(2))-induced injury in H9c2 embryonic rat cardiac cells. 2. After 36 h incubation in the presence of 600 micromol/L CoCl(2), reduced cell viability of H9c2 cells was observed, as well as the induction of apoptosis. In addition, CoCl(2) (600 micromol/L) enhanced the production of reactive oxygen species (ROS) and the expression of cleaved caspase 3, induced a loss of mitochondrial membrane potential (MMP) and decreased reduced glutathione (GSH) production. These results suggest that CoCl(2) induces similar responses to hypoxia/ischaemia. 3. Pretreatment of cells with 400 micromol/L NaHS (a H(2)S donor) for 30 min prior to exposure to CoCl(2) (600 micromol/L) significantly protected H9c2 cells against CoCl(2)-induced injury. Specifically, increased cell viability and decreased apoptosis were observed. In addition, NaHS pretreatment blocked the CoCl(2)-induced increases in ROS production and cleaved caspase 3 expression, as well as the decreases in GSH production and loss of MMP. 4. Pretreatment of cells with 2000 micromol/L N-acetylcysteine (NAC), a ROS scavenger, for 1 h prior to CoCl(2) exposure significantly protected H9c2 cells against CoCl(2)-induced injury, specifically enhancing cell viability, decreasing ROS production and preventing loss of MMP. 5. The findings of the present study suggest that H(2)S protects H9c2 cells against CoCl(2)-induced injury by suppressing oxidative stress and caspase 3 activation.