Resveratrol attenuates cigarette smoke induced endothelial apoptosis by activating Notch1 signaling mediated autophagy.

BACKGROUND: Increasing evidence shows that endothelial apoptosis contributes to cigarette smoke (CS)-induced disease progression, such as chronic obstructive pulmonary disease (COPD). Our previous studies have validated Notch1 as an anti-apoptotic signaling in CS-induced endothelial apoptosis. Resveratrol (RESV) is a naturally occurring polyphenol that exhibits an anti-apoptotic activity in endothelial cells that exposed to many kinds of destructive stimulus. However, the effects of resveratrol on Notch1 signaling in CS-induced endothelial apoptosis have not yet been fully elucidated. Therefore, the aim of this study was to examine whether RESV can protect endothelial cells from CS-induced apoptosis via regulating Notch1 signaling. METHODS: Human umbilical vein endothelial cells (HUVECs) were pretreated with RESV for 2 h, followed by cotreatment with 2.5%CSE for 24 h to explore the role of RESV in CSE induced endothelial apoptosis. 3-methyladenine (3-MA) or rapamycin was used to alter autophagic levels. Lentivirus Notch1 intracellular domain (LV-N1ICD), γ-secretase inhibitor (DAPT) and Notch1 siRNA were used to change Notch1 expression. The expression of Notch1, autophagic and apoptotic markers were examined by Western blot and the apoptosis rate was detected by Flow cytometry analysis. RESULTS: Our results showed that activating autophagy reduced CSE-induced endothelial apoptosis, while blocking autophagy promoted cell apoptosis in HUVECs. RESV pretreatment attenuated the CSE-induced endothelial apoptosis and activated Notch1 signaling. RESV pretreatment also increased LC3b-II and Beclin1 production, decreased p62 and mTOR expression. 3-MA treatment inhibited autophagy and aggravated CSE induced apoptosis, while rapamycin promoted autophagy, led to a decrease in cell apoptosis. LV-N1ICD transfection upregulated autophagy and reduced apoptosis. However, this protective effect was abolished by 3-MA treatment. In cells treated with DAPT or Notch1 siRNA, autophagy was decreased, while apoptosis was increased. RESV partly rescued the DAPT or Notch1 siRNA induced apoptosis by activating Notch1 signaling. CONCLUSION: In HUVECs, RESV attenuates CSE induced endothelial apoptosis by inducing autophagy in a Notch1-dependent manner.

Multifaceted role of prohibitin in cell survival and apoptosis.

Human eukaryotic prohibitin (prohibitin-1 and prohibitin-2) is a membrane protein with different cellular localizations. It is involved in multiple cellular functions, including energy metabolism, proliferation, apoptosis, and senescence. The subcellular localization of prohibitin may determine its functions. Membrane prohibitin regulate the cellular signaling of membrane transport, nuclear prohibitin control transcription activation and the cell cycle, and mitochondrial prohibitin complex stabilize the mitochondrial genome and modulate mitochondrial dynamics, mitochondrial morphology, mitochondrial biogenesis, and the mitochondrial intrinsic apoptotic pathway. Moreover, prohibitin can translocates into the nucleus or the mitochondria under apoptotic signals and the subcellular shuttling of prohibitin is necessary for apoptosis process. Apoptosis is the process of programmed cell death that is important for the maintenance of normal physiological functions. Consequently, any alteration in the content, post-transcriptional modification (i.e. phosphorylation) or the nuclear or mitochondrial translocation of prohibitin may influence cell fate. Understanding the mechanisms of the expression and regulation of prohibitin may be useful for future research. This review provides an overview of the multifaceted and essential roles played by prohibitin in the regulation of cell survival and apoptosis.

[Effect of Th1/Th2 cytokine immune imbalance on the expression of nerve growth factors in asthma].

OBJECTIVE: To explore the effect of Th1/Th2 cytokines on the expression of nerve growth factor(NGF)in splenic lymphocytes in asthmatic model. METHODS: Four SD rats were sensitized and challenged with ovalbumin to establish an asthmatic model, and the rat splenic lymphocytes were isolated and cultured with ConA. The expressions of NGF mRNA were detected by reverse transcription-polymerase chain reaction (RT-PCR), and were observed after the lymphocytes were exogenously added with interferon-gamma(IFN-gamma) or interleukin-4 (IL-4). RESULTS: The lymphocytes of the asthmatic model stimulated by ConA in vitro expressed NGF mRNA in a time-dependent manner. After the lymphocytes had been cultured with IL-4 for 12 h, 24 h, 36 h, and 48 h, 50 microg/L IL-4 upregulated the expressions of NGF mRNA in a time-dependent manner and all the NGF mRNA expressions were significantly higher than the basal values at the same time(all Ps<0.01). After 0, 10, 50, and 100 microg/L IL-4 had been added for 24 h, IL-4 upregulated the expressions of NGF mRNA in a dose-dependent manner and the NGF mRNA expressions were all significantly higher than the values of the lower dose IL-4(all Ps<0.05). After the lymphocytes had been cultured with 10 mug/L IFN-gamma for 0 h, 12 h, 24 h, 36 h, and 48 h, IFN-gamma downregulated the expressions of NGF mRNA in a time-dependent manner and all the NGF mRNA expressions were significantly lower than the basal values at the same time(all Ps<0.01). After 0, 1, 10, and 50 microg/L IFN-gamma have been added for 24 h, IFN-gamma downregulated the expressions of NGF mRNA in a dose-dependent manner and all the NGF mRNA expressions were significantly lower than the values of the lower IFN-gamma dose(all Ps<0.05). CONCLUSION: In the splenic lymphocytes of asthmatic rats, IL-4, one of the Th2 cytokines, can upregulate the expressions of NGF; IFN-gamma, one of the Th1 cytokines, can downregulate the expressions of NGF both in a time-dependent manner and in a dose-dependent manner. Th1/Th2 cytokine immune imbalance may indirectly induce the airway neurogenic inflammation by regulating the NGF mRNA expression.

[Changes of nerve growth factor and its receptors in the lung tissues in asthmatic rats and their effects on the airway inflammation].

OBJECTIVE: To determine the expression of nerve growth factor (NGF), tyrosine kinase receptor A (trkA), and pan-neurotrophin receptor (p75) in the lung tissues in asthmatic rats, and to explore their effects on the airway inflammation. METHODS: Thirty-two SD rats were randomly divided into 4 groups: the control, asthma, NGF and anti-NGF groups. The asthmatic model was established by the inhalation and injection of ovalbumin. The total cell count and differential cell count in the bronchoalveolar lavage fluid (BALF) were performed. The pathologic changes in the lung tissues of the 4 groups was detected by HE staining. The NGF mRNA expression in the lung tissues of the asthma and control groups was determined by reverse transcription-polymerase chain reaction (RT-PCR). The changes of trkA and p75 mRNA expressions in the lung tissues in the 4 groups were also investigated by RT-PCR. RESULTS: Compared with the control group, the BALF total cell, the BALF eosinophils (Eos), and the BALF lymphocytes (Lyms) significantly increased (All P <0. 001) in the asthma group; and the lung tissues of the asthma group had more infiltrating inflammatory cells. Not only the expression of NGF mRNA, but also its receptors trkA and p75 mRNA in the lung tissues were significantly higher in the asthma group than those in the control group (All P < 0.01). Positive correlation was found between the expression of NGF mRNA and the BALF total cell, the BALF Lyms in the asthma group. Compared with the asthma group, the total cell, the Eos, and the lyms in BALF in the NGF group significantly increased (All P < 0.01), and the lungs of the NGF group had apparent inflammatory changes. The expre-ssions of p75 and trkA mRNA were enhanced significantly (All P < 0.05). Compared with the asthma group, the total cell, the Eos, and the lyms in BALF in the anti-NGF group significantly decreased (All P < 0.001), and the lungs of the anti-NGF group showed alleviative inflammatory changes. The expre-ssions of p75 and trkA mRNA significantly decreased (All P < 0.01). CONCLUSION: In lungs of asthmatic rats, the elevated expression of NGF mRNA is closely related to the airway inflammation. NGF can upregulate the expressions of p75 and trkA mRNA in asthmatic rats, and then may promote their role in the airway neuronal inflammation in asthma.

Effects and mechanism of arsenic trioxide on reversing the asthma pathologies including Th17-IL-17 axis in a mouse model.

In traditional Chinese medicine, arsenous compounds, including arsenic trioxide (ATO), are often used to treat many diseases, which are safe and effective. Recently, studies have indicated that Th17- IL-17 involved in the pathogenesis and development of asthma. The goal of this study was to investigate the effect and mechanism of ATO on asthma, especially the Th17- IL-17 axis.We used oval bumin (OVA)-immunized mice as a model for asthma and treated mice with ATO or dexamethasone. The mice were then monitored airway responsiveness, airway inflammation, mucus production, IL-17 levels in BALF and the positive rate of Th17 cells. In vitro, CD4+ T cells from splenic cell suspensions were separated and purified. We measured the expression of IL-17 and caspase-12 protein in purified CD4+ T cells, and detected IL-17 levels in CD4+ T lymphocyte culture solution with or without ATO. Moreover, apoptosis, mitochondrial membrane potential, cytosolic calcium were analyzed. We found that ATO could reduce airway responsiveness, airway inflammation, mucus hyperplasia, the expression of IL-17 in BALF and the positive rate of Th17 cells at a level comparable to treatment with DXM. In vitro data suggested that ATO can induce CD4+ T cells apoptosis, cause mitochondrial dysfunction, Ca2+ overload and promote caspase-12 activation. Our study suggested that ATO had potential medical value for the treatment of human asthma..