The effect of hypoxia on Hydrogen Sulfide concentration of brain tissue in AD transgenic mice and its mechanism.

OBJECTIVE: Research has shown that hydrogen sulfide (H2S) plays a protective role in many diseases of the nervous system. The aim of this study is to investigate the effect of hypoxia on endogenous H2S concentration in the cerebral cortex of Alzheimer's disease (AD) transgenic mice and its mechanism. METHODS: AD transgenic mice were raised in closed boxes and pure nitrogen was introduced to reduce the oxygen concentration to 8%-10%, establishing an animal model of hypoxia. Oxygen partial pressure was measured with an oxygen meter. The expression of cystathionine-ß-synthase (CBS) in cerebral cortex tissue was determined by Western blot, and H2S concentration was measured by a modified methylene blue method. RESULTS: (1) Hypoxia down-regulated CBS expression in cerebral cortex tissue of AD transgenic mice (p < 0.05). (2) The concentration of H2S in the cerebral cortex tissue of the hypoxic transgenic group was significantly lower than that of the Control group (p < 0.01). (3) Overexpression of CBS reversed the hypoxia-induced decrease of H2S concentration in the cerebral cortex tissue of AD transgenic mice (p < 0.01). CONCLUSIONS: Hypoxia decreased the concentration of endogenous H2S in the cerebral cortex tissue of AD transgenic mice by down-regulating the expression of CBS.

Invasive Blood Pressure Measurement and In-hospital Mortality in Critically Ill Patients With Hypertension.

Background: Invasive blood pressure (IBP) measurement is common in the intensive care unit, although its association with in-hospital mortality in critically ill patients with hypertension is poorly understood. Methods and Results: A total of 11,732 critically ill patients with hypertension from the eICU-Collaborative Research Database (eICU-CRD) were enrolled. Patients were divided into 2 groups according to whether they received IBP. The primary outcome in this study was in-hospital mortality. Propensity score matching (PSM) and inverse probability of treatment weighing (IPTW) models were used to balance the confounding covariates. Multivariable logistic regression was used to evaluate the association between IBP measurement and hospital mortality. The IBP group had a higher in-hospital mortality rate than the no IBP group in the primary cohort [238 (8.7%) vs. 581 (6.5%), p < 0.001]. In the PSM cohort, the IBP group had a lower in-hospital mortality rate than the no IBP group [187 (8.0%) vs. 241 (10.3%), p = 0.006]. IBP measurement was associated with lower in-hospital mortality in the PSM cohort (odds ratio, 0.73, 95% confidence interval, 0.59-0.92) and in the IPTW cohort (odds ratio, 0.81, 95% confidence interval, 0.67-0.99). Sensitivity analyses showed similar results in the subgroups with high body mass index and no sepsis. Conclusions: In conclusion, IBP measurement was associated with lower in-hospital mortality in critically ill patients with hypertension, highlighting the importance of IBP measurement in the intensive care unit.

Hydrogen Sulfide Protects against Chemical Hypoxia-Induced Injury via Attenuation of ROS-Mediated Ca2+ Overload and Mitochondrial Dysfunction in Human Bronchial Epithelial Cells.

Oxidative stress induced by hypoxia/ischemia resulted in the excessive reactive oxygen species (ROS) and the relative inadequate antioxidants. As the initial barrier to environmental pollutants and allergic stimuli, airway epithelial cell is vulnerable to oxidative stress. In recent years, the antioxidant effect of hydrogen sulfide (H2S) has attracted much attention. Therefore, in this study, we explored the impact of H2S on CoCl2-induced cell injury in 16HBE14o- cells. The effect of CoCl2 on the cell viability was detected by Cell Counting Kit (CCK-8) and the level of ROS in 16HBE14o- cells in response to varying doses (100-1000 µmol/L) of CoCl2 (a common chemical mimic of hypoxia) was measured by using fluorescent probe DCFH-DA. It was shown that, in 16HBE14o- cells, CoCl2 acutely increased the ROS content in a dose-dependent manner, and the increased ROS was inhibited by the NaHS (as a donor of H2S). Moreover, the calcium ion fluorescence probe Fura-2/AM and fluorescence dye Rh123 were used to investigate the intracellular calcium concentration ([Ca2+]i) and mitochondria membrane potential (MMP) in 16HBE14o- cells, respectively. In addition, we examined apoptosis of 16HBE14o- cells with Hoechst 33342. The results showed that the CoCl2 effectively elevated the Ca2+ influx, declined the MMP, and aggravated apoptosis, which were abrogated by NaHS. These results demonstrate that H2S could attenuate CoCl2-induced hypoxia injury via reducing ROS to perform an agonistic role for the Ca2+ influx and MMP dissipation.

Leptin Is Oversecreted by Respiratory Syncytial Virus-Infected Bronchial Epithelial Cells and Regulates Th2 and Th17 Cell Differentiation.

BACKGROUND: Infection of human bronchial epithelial cells (hBECs) with respiratory syncytial virus (RSV) has been shown to induce a Th lymphocyte subset drift, e.g. enhanced differentiation of Th2 and Th17 subsets, which is a classic characteristic of asthma. However, the molecules responsible for the drift in Th subsets remain unknown. This study aims to determine the expression of leptin in RSV-infected hBECs, and its role in Th2 and Th17 cell differentiation and extracellular regulated kinase (ERK) 1/2 phosphorylation. METHODS: Cultured hBECs were infected with RSV. mRNA expression of the LEP gene in cells was measured by real-time PCR while LEP protein secretion in culture medium was measured by ELISA. Th differentiation was investigated in cultured human peripheral blood mononuclear cells following stimulation with recombinant human leptin. Th2 and Th17 subsets were examined by flow cytometry. Phosphorylation of the ERK1/2 protein in lymphocytes was detected by Western blot and immunofluorescence. RESULTS: LEP mRNA expression was significantly upregulated in RSV-infected hBECs while the leptin protein level in the supernatants of RSV-infected hBECs was significantly increased. Stimulation of lymphocytes with leptin increased the differentiation of the Th17 subset and ERK1/2 phosphorylation, but suppressed Th2 subset differentiation. CONCLUSION: Leptin was oversecreted by RSV-infected hBECs, which promoted Th17 subset differentiation but suppressed Th2 subset differentiation possibly via regulating ERK1/2 phosphorylation.

[Expression of transient receptor potential canonical 1 in ozone-induced inflammatory lung tissues in mice].

OBJECTIVE: To detect the expression of transient receptor potential canonical 1 (TRPC1) in a mouse model of ozone-induced lung inflammation and explore its role in lung inflammation. METHODS: In a mouse model of lung inflammation established by ozone exposure, the expression of TRPC1 in the inflammatory lung tissues was detected by RT-PCR, Wstern blotting and immunohistochemistry. RESULTS: Compared to the control mice, the mice exposed to ozone showed significantly increased expression level of TRPC1 mRNA and protein in the inflammatory lung tissues (P<0.05). Immunohistochemistry showed increased TRPC1 protein expressions in the alveolar epithelial cells, bronchial epithelial cells, and inflammatory cells in the inflammatory lung tissues (P<0.05). The mRNA and protein expression levels of TRPC1 were positively correlated with the counts of white blood cells, macrophages, neutrophils and lymphocytes in the bronchoalveolar lavage fluid of the exposed mice (P<0.01). CONCLUSION: TRPC1 may play a role in ozone-induced lung inflammation in mice.

[Effects on blood fat and bone density of postmenopausal women fed by soy protein with isoflavone].

OBJECTIVE: To explore the effects of phytoestrogen (PE) on blood lipid and bone density in postmenopausal women. METHODS: A total of 75 menopausal women aged 50-70 years with estrogen reduction symptoms received an intake of soy protein containing 70 mg isoflavone daily in a year. Their changes of blood fat, density lumbar bone and sex hormone level were compared with control group without an intake. RESULTS: The changes of blood triglyceride (TG), total cholesterol (TC) and low-density lipoprotein (LDL) in two groups before and after a year showed no statistical significance.High-density lipoprotein (HDL) decreased in control group while it had no significant change in the study group. Bone densities in two groups showed a downward trend by an annual rate of 1%-4%, the changes in two groups showed no statistical significance.E2 increased slightly over basic value in the study group. But it had no statistical significance. The changes of follicle-stimulating hormone (FSH) in two groups were also similar. CONCLUSION: The above soy protein preparation has no effect on hypothalamic-pituitary-ovarian axis and no stimulation on endometrium of uterus. But it may improve the profile of HDL.

Progressive changes in inflammatory and matrix adherence of bronchial epithelial cells with persistent respiratory syncytial virus (RSV) infection (progressive changes in RSV infection).

In addition to the acute manifestations of respiratory syncytial virus (RSV), persistent infection may be associated with long-term complications in the development of chronic respiratory diseases. To understand the mechanisms underlying RSV-induced long-term consequences, we established an in vitro RSV (strain A2) infection model using human bronchial epithelial (16HBE) cells that persists over four generations and analyzed cell inflammation and matrix adherence. Cells infected with RSV at multiplicity of infection (MOI) 0.0067 experienced cytolytic or abortive infections in the second generation (G2) or G3 but mostly survived up to G4. Cell morphology, leukocyte and matrix adherence of the cells did not change in G1 or G2, but subsequently, leukocyte adherence and cytokine/chemokine secretion, partially mediated by intercellular adhesion molecule-1 (ICAM-1), increased drastically, and matrix adherence, partially mediated by E-cadherin, decreased until the cells died. Tumor necrosis factor-α (TNF-α) secretion was inhibited by ICAM-1 antibody in infected-16HBE cells, suggesting that positive feedback between TNF-α secretion and ICAM-1 expression may be significant in exacerbated inflammation. These data demonstrate the susceptibility of 16HBE cells to RSV and their capacity to produce long-term progressive RSV infection, which may contribute to inflammation mobilization and epithelial shedding.

Store-operated Ca2+ channels blockers inhibit lipopolysaccharide induced astrocyte activation.

The destruction of calcium homeostasis is an important factor leading to neurological diseases. Store-operated Ca(2+) (SOC) channels are essential for Ca(2+) homeostasis in many cell types. However, whether SOC channels are involved in astrocyte activation induced by lipopolysaccharide (LPS) still remains unknown. In this study, we used LPS as an exogenous stimulation to investigate the role of SOC channels in astrocyte activation. Using calcium imaging technology, we first found that SOC channels blockers, 1-[h-[3-(4-methoxyphenyl)propoxy]-4-methoxyphenethyl]-1H-imidazole (SKF-96365) and 2-aminoethyldiphenyl borate (2-APB), inhibited LPS induced [Ca(2+)]i increase, which prompted us to speculate that SOC channels may be involved in LPS induced astrocyte activation. Further experiments confirmed our speculation shown as SOC channels blockers inhibited LPS induced astrocyte activation characterized as cell proliferation by MTS and BrdU assay, raise in glial fibrillary acidic protein expression by immunofluorescence and Western Blot and secretion of interleukin 6 (IL-6) and interleukin 1ß (IL-1ß) by ELISA. So, our studies showed that SOC channels are involved in LPS-induced astrocyte activation.

Hydrogen sulfide prevents hypoxia-induced apoptosis via inhibition of an H2O2-activated calcium signaling pathway in mouse hippocampal neurons.

Hydrogen sulfide (H(2)S), an endogenous gaseous mediator, has been shown to exert protective effects against damage to different organs in the human body caused by various stimuli. However, the potential effects of H(2)S on hypoxia-induced neuronal apoptosis and its mechanisms remain unclear. Here, we exposed mouse hippocampal neurons to hypoxic conditions (2% O(2), 5% CO(2) and 93% N(2) at 37 °C) to establish a hypoxic cell model. We found that 4-h hypoxia treatment significantly increased intracellular reactive oxygen species (ROS) levels, and pretreatment with NaHS (a source of H(2)S) for 30 min suppressed hypoxia-induced intracellular ROS elevation. The hypoxia treatment significantly increased cytosolic calcium ([Ca(2+)](i)), and pretreatment with NaHS prevented the increase in [Ca(2+)](i). Additionally, polyethylene glycol (PEG)-catalase (a H(2)O(2) scavenger) but not PEG-SOD (an O(2)(-) scavenger) conferred an inhibitory effect similar to H(2)S on the hypoxia-induced increase in [Ca(2+)](i). Furthermore, we found that pretreatment with NaHS could significantly inhibit hypoxia-induced neuronal apoptosis, which was also inhibited by PEG-catalase or the inositol 1,4,5-triphosphate (IP(3)) receptor blocker xestospongin C. Taken together, these findings suggest that H(2)S inhibits hypoxia-induced apoptosis through inhibition of a ROS (mainly H(2)O(2))-activated Ca(2+) signaling pathway in mouse hippocampal neurons.