Reduced Plasma Estradiol Levels are Associated with Sleep Apnea in Depressed Peri- and Post-Menopausal Women.

OBJECTIVE: This study aimed at investigating the correlation between estradiol and sleep apnea among women with major depressive disorders during the perimenopausal and postmenopausal periods. METHODS: A total of 84 perimenopausal and postmenopausal women diagnosed with depression, and who had been subjected to whole-night polysomnography (PSG) were retrospectively studied. They were assigned into two groups based on the presence of OSA (apnea-hypopnea index (AHI)≥5) (OSA vs non-OSA). The correlation between estradiol levels and apnea-hypopnea index were assessed by logistic regression models after adjusting for age, body mass index (BMI), Hamilton Depression Rating Scale (HAMD), Pittsburgh Sleep Quality Index (PSQI), apnea frequency and progesterone. RESULTS: Among the 84 patients, 45.23% had OSA. Estradiol levels were significantly elevated in non-OSA than in OSA patients (p<0.05). Univariate analysis revealed that elevated estradiol levels are associated with reduced odds of OSA (odds ratio [OR] 0.92, 95% confidence interval [CI] 0.875-0.966, p = 0.001). Multivariate analyses showed that low estradiol levels (OR = 0.859, 95% CI 0.826-0.991, p = 0.031), higher HAMD scores (OR = 1.212, 95% CI 1.012-1.453, p = 0.037), higher apnea frequency (OR = 2.493, 95% CI 1.389-4.473, p = 0.002) and higher BMI (OR=1.635, 95% CI 1.136-2.353, p = 0.008) are correlated with OSA. CONCLUSION: The ratio of depressed perimenopausal to postmenopausal women comorbid OSA was high. Higher BMI, low estradiol levels, high apnea frequency and high HAMD scores were correlated with OSA diagnosis and could be potential diagnostic markers for OSA in depressed perimenopausal and postmenopausal women. Reduced estradiol levels were correlated with an increased risk of OSA among depressed perimenopausal and postmenopausal women.

MicroRNA expression changes in the hippocampi of rats subjected to global ischemia.

The hippocampus is particularly vulnerable to ischemia, which is accompanied by substantial alterations in gene expression. Recent studies show that microRNAs extensively mediate post-transcriptional gene expression. However, the regulatory mechanisms in the hippocampus that microRNAs participate in remain unclear. Here, we used microarray analysis to characterize the microRNA expression profile in rat hippocampus and to identify changes in expression after 20 minutes of global ischemia followed by either 30 minutes or 24 hours of reperfusion. In the normal hippocampus, we detected 286 microRNAs, of which the let-7 family accounted for 32%. After ischemia followed by 30 minutes of reperfusion, 23 microRNAs were upregulated and 32 were downregulated; after 24 hours of reperfusion 40 were upregulated and 31 were downregulated. These results suggest that several microRNAs may be involved in regulating the normal physiological activity of the hippocampus and its response to ischemia and reperfusion.

[The properties and research methods of pannexins].

The gene encoding pannexin is a new gap junction family member discovered in 2000. Recent studies indicated that pannexin protein can form hemichannel on the membrane or intercellular gap junction channel, which is involved in many physiological and pathological activities. Here, we make a review of the latest research progress on the expression and cellular localization, the channel properties and the research methods of pannexins in an attempt to provide some evidences and methodological references to further investigation on the physiological and pathological functions of pannexin.