ObjectiveTo detect the expression level of phosphate and tension homolog deleted on chromsome ten(PTEN) and its downstream signal molecules phosphorylated protein kinase B (p-AKT) in liver cells of rats during intermittent hypoxia,to investigate the effect of PTEN and p-AKT of liver cells on insulin resistance which intermittent hypoxia is relevant. MethodsA total of 24 healthy male SD rats were selected and divided into 3 groups randomly,ie.CIA (chronic intermittent air) group,CIH4 (chronic intermittent hypoxia for 4 weeks) group,and CIH8 (chronic intermittent hypoxia for 8 weeks) group. The fasting blood glucose,fasting insulin,PTEN and p-AKT expressions in the liver cells were detected. The insulin resistance was evaluated systematically by the insulin sensitive index (ISI) and homeostasis model assessment of insulin resistance (HOMA-IR). Average gray value was used to represent the protein expressions of PTEN and p-AKT. ResultsCompared with CIA group,the decline of ISI in CIH4 group and CIH8 group was significant (P<0.05). Furthermore,the decline in CIH8 group was more significant than that in CIH4 group (P<0.05). Compared with CIA group,the rise of HOMA-IR in CIH4 and CIH8 groups was statistically significant (P<0.05). In addition,the rise in CIH8 group was more significant than that in CIH4 group (P<0.05). Compared with CIA group,there was a significant rise in the protein expressions of PTEN in CIH4 and CIH8 groups (P<0.05). Compared with CIH4 group,the rise of the protein expressions of PTEN in CIH8 group was still statistically significant (P<0.05). Compared with CIA group,there was a significant decline in the protein expressions of p-AKT in CIH4 and CIH8 groups (P<0.05). Compared with CIH4 group,the decline of protein expression of p-AKT in CIH8 group was still of statistical significance (P<0.05). There was a significantly increasing trend for the expression of PTEN in the liver cells of rats with intermittent hypoxia along with the decline of ISI and rise of HOMA-IR. The expression increased significantly with the longer duration of intermittent hypoxia. The expression of p-AKT in liver cells of rats with intermittent hypoxia decreased along with the decline of ISI and rise of HOMA-IR. Furthermore,the decline tendency was more significant with the long duration of intermittent hypoxia. ConclusionThe fasting blood glucose of rats and insulin level increase due to the chronic intermittent hypoxia,resulting in the insulin resistance. The degree of insulin resistance increases with the longer duration of intermittent hypoxia. The expression of PTEN protein increases with intermittent hypoxia,and that of p-AKT protein decreases,which is obviously correlated with ISI and HOMA-IR. It is indicated that the PTEN protein possibly play an important role in the mechanism of insulin resistance for rats with intermittent hypoxia.
Objective To explore the correlation between the levels of serum nuclear factor-erythroid 2-related factor 2 (Nrf2) as well as heme oxygenase-1 (HO-1) and cognitive dysfunction by determining the levels of Nrf2 and HO-1 in patients with obstructive sleep apnea (OSA) to different degrees and combining Montreal cognitive assessment (MoCA). Methods Serum levels of Nrf2 and HO-1 were determined in 32 patients with mild-moderate OSA, 23 patients with severe OSA and 20 healthy controls. The differences of Nrf2 and HO-1 levels among groups were compared. All subjects were evaluated by MoCA score. According to MoCA score, OSA patients were divided into two groups: OSA with mild cognitive impairment (MCI) group and OSA with normal cognition group. Serum Nrf2 and HO-1 levels were compared between the two groups, and the differences in the OSA patients with or without cognitive impairment were understood. Spearman correlation coefficient was used to explore the correlation between serum Nrf2 and HO-1 levels and cognitive function of OSA patients. The diagnostic value of serum Nrf2 and HO-1 in the OSA patients with cognitive impairment was determined by receiver operating characteristic curve. Results Serum levels of Nrf2 and HO-1 in the mild-moderate and severe OSA groups were higher than those in the control group, and those in the severe OSA group were higher than those in the mild-moderate OSA group (P<0.05). Compared with the OSA with normal cognition group, the serum HO-1 level in the OSA patients with MCI was higher (P<0.05), but the serum NRF2 level had no significant difference between the two groups (P>0.05). There was a negative correlation between serum HO-1 level and total MoCA score in the OSA patients (r=–0.495, P=0.000), but there was no significant correlation between serum Nrf2 and total MoCA score in the OSA patients (P>0.05). Serum Nrf2 and HO-1 were 0.791 and 0.818 for predicting OSA patients with cognitive impairment. The sensitivity was 84.20% and 86.80%, and the specificity was 67.60% and 73.00%, respectively. Conclusions Serum Nrf-2 and serum HO-1 play important role in the pathogenesis of OSA. Serum HO-1 level may be closely related to cognitive dysfunction in OSA patients. Detection of serum HO-1 may be helpful in early identification of cognitive dysfunction in OSA patients, which has potential clinical application value.