Effects of Antioxidant Tempol on Systematic Inflammation and Endothelial Apoptosis in Emphysematous Rats Exposed to Intermittent Hypoxia

PURPOSE: Obstructive sleep apnea and chronic obstructive pulmonary disease are independent risk factors of cardiovascular disease (CVD), and their coexistence is known as overlap syndrome (OS). Endothelial dysfunction is the initial stage of CVD; however, underlying mechanisms linking OS and CVD are not well understood. The aim of this study was to explore whether OS can lead to more severe inflammation and endothelial apoptosis by promoting endothelial dysfunction, and to assess the intervention effects of antioxidant tempol. MATERIALS AND METHODS: Male Wistar rats (n=66) were exposed to normal oxygen [normal control (NC) group], intermittent hypoxia (IH group), cigarette smoke (CH group), as well as cigarette smoke and IH (OS group). Tempol intervention was assessed in OS group treated with tempol (OST group) or NaCl (OSN group). After an 8-week challenge, lung tissues, serum, and fresh blood were harvested for analysis of endothelial markers and apoptosis. RESULTS: The levels of intracellular adhesion molecule-1, vascular cellular adhesion molecule-1, and apoptosis in circulating epithelial cells were the highest in OS group and the lowest in NC group. These levels were all greater in IH group than in CH group, and were lower in OST group than in OS and OSN groups (all p < 0.001). CONCLUSION: Synergistic effects of IH with cigarette smoke-induced emphysema produce a greater inflammatory status and endothelial apoptosis. OS-related inflammation and endothelial cell apoptosis may play important roles in promoting cardiovascular dysfunction, and antioxidant tempol could achieve a partial protective effect.

Effects of different degrees of intermittent hypoxia on the activation and the extracellular matrix secretion of mouse lung fibroblast cells / 天津医药

Objective To explore the effects of different degrees of intermittent hypoxia (IH) on the activation and the secretion of extracellular matrix in MLg lung fibroblast cell line. Methods MLg lung fibroblast cells in logarithmic growth phase were exposed for 5%O2 for 100 seconds and 21%O2 for 120 seconds in 1 h, 4 h and 8 h groups (IH1, IH4 and IH8) and normoxia group (21%O2 for 8 h, N group). The cells in each group were collected at the end of experiment. Real-time PCR was used to measure the mRNA expression levels ofα-SMA and typeⅠcollagen (COL1) A1, and Western blot assay was used to detect the protein expression levels ofα-SMA and COL1. Results The mRNA and protein expression levels ofα-SMA and COL1 were significantly increased in IH1, IH4 and IH8 groups than those in N group (all P < 0.05). Furthermore, expression levels of α-SMA and COL1 showed a time-dependent increase with IH exposure time. Conclusion The intermittent hypoxia can promote the cell activation and the extracellular matrix secretion of mouse lung fibroblast cells, which may be related with the oxidative stress.

Effects of OSAS model IH on the expressions of YAP and P-YAP in lung cancer cell lines / 天津医药

Objective To explore the effect of obstructive sleep apnea syndrome (OSAS), OSAS-like intermittent hypoxia (IH)on the expression levels of P-YAP and YAP in A549 lung cancer cell lines. Methods A549 cells were treated with IH exposure ( exposed to 5%O2 for 300 seconds and 21%O2 for 300 seconds) for 1, 3 and 6 h (IH1, IH3, IH6) or normoxia exposure (N group). Quantificational real-time PCR was used to measure the mRNA expression levels of YAP. Western blot assay was used to detect the protein expression levels of YAP and P-YAP. Results The mRNA expression levels of YAP were significantly increased with the increase of IH exposure time points in IH1 (2.50±0.18), IH3 (4.07±0.25) and IH6 (9.18 ± 0.58) groups than those in N group (1.00 ± 0.01) (all P<0.05). The protein expression levels of YAP were significantly increased with the increase of IH exposure time points in IH1, IH3 and IH6 groups than those in N group. The protein expression levels of P-YAP were significantly decreased with the increase of IH exposure time points in IH 1, IH3 and IH6 groups than those in N group. Conclusion YAP cell signaling plays an important role in the process of OSAS-like IH induced tumor development.

Effects of cobalt chloride-induced hypoxia on cell migration and expression and secretion of FSTL1 in melanoma cell line / 天津医药

Objective To explore the effects of cobalt chloride (CoCl2)-induced hypoxia on migration of melanoma cells, and to detect the transcription, expression and secretion of Follistatin-like 1(FSTL1) in this process. Methods B16F10 melanoma cell line was treated with CoCl2 in order to mimic hypoxia. Experimental cells were divided into three groups: 0μmol/L, 50μmol/L and 100μmol/L CoCl2 treatment groups. MTT assay was used to assure cell viability, and to determine the treatment concentration of CoCl2. Transwell assay was used to determine the migration ability of B16F10 melanoma cell line. Real-time PCR was used to measure the mRNA expression of Fstl1. Western blot assay was used to detect the intracel?lular and extracellular protein expression of FSTL1. Results The cell viability of B16F10 melanoma cell line was signifi?cantly reduced by CoCl2 treatment, with a time and concentration-dependent manner. The migration ability of B16F10 cell line was significantly increased in CoCl2 treated group compared with that of control group (P<0.05). The mRNA level of Fstl1 was obviously higher in CoCl2 treated group than that of control group (P<0.05). The intracellular expression of FSTL1 protein was consistent with the expression trend of Fstl1 mRNA. Simultaneously, the extracellular protein level of FSTL1 was significantly decreased compared with that of control group. There was no expression of FSTL1 in 100μmol/L CoCl2 treat?ment group. Conclusion The migration ability of melanoma cell line is enhanced by CoCl2 treatment, which may be associ?ated with expression and secretion of FSTL1, however, the relevant mechanism still needs further investigation.