Oxidative stress plays a critical role in the etiology and pathogenesis of neurodegenerative disorders, and the molecular mechanisms that control the neuron response to ROS have been extensively studied. However, the oxidative stress-effect on miRNA expression in hippocampal neurons has not been investigated, and little is known on the effect of ROS-modulated miRNAs on cell function. In this study, H₂O₂ was used to stimulate the mouse primary hippocampal neurons to develop an oxidative stress cell model. The alterations of miRNAs expression were detected by microarray analysis and five miRNAs were validated by real-time RT-PCR. The bioinformatic analysis of deregulated miRNAs was performed to determine their potential roles in the pathogenesis of neurological disorders. We found that H₂O₂ mediated a total of 101 deregulated miRNAs, which mainly took part in the regulation of the MAPK pathway. Among them, miR-135b and miR-708 were up-regulated significantly and their targets were predicted to be involved in DNA recombination, protein ubiquitination, protein autophosphorylation and development of neurons. These results demonstrated that oxidative stress alters the miRNA expression profile of hippocampal neurons, and the deregulated miRNAs might play a potential role in the pathogenesis of neurodegenerative diseases, such as Alzheimer’s disease (AD).

To examine the comorbidity between insomnia and medical conditions. This cross-sectional study was conducted in community adults, aged ≥ 60 years, who resided in one of four major cities in northern China. Sociodemographic and clinical data were collected simultaneously. A total of 3,176 elderly adults (1,292 male, mean ± standard deviation age 70.2 ± 6.8 years; 1,884 female, 68.8 ± 6.7 years) were interviewed. The prevalence of specific medical conditions in both people with insomnia and people without insomnia was detected. Significantly higher proportions of arrhythmia, hypertension, cerebral hemorrhage, migraine, and hyperlipidemia were observed in people with insomnia than in people without insomnia. Moreover, a significantly higher proportion of insomnia was seen in elderly people with arrhythmia and migraine. We also found that elderly people with insomnia who took sleep medications reported a higher prevalence of coexisting arrhythmia, hypertension, and migraine, even after adjusting for age, sex, and depression. Our results indicate associations between insomnia and medical conditions in the community elderly in China. People who complained of insomnia had poorer physical health conditions. Sleep medication may not be a covariate that influences the comorbidity of some specific physical conditions. Trial name: The study of diagnosis and treatment of senile dementia in Hebei Province; URL: http://www.chictr.org.cn/showproj.aspx?proj=8194; Registration number: ChiCTR-RRC-11001345.

Evidence has demonstrated that vascular risk factors (VRFs) contribute to mild cognitive impairment (MCI) in the elderly population. Because of the race and different diagnosis standard, there is still no definitive conclusions. To estimate the VRFs and potential protective factors for MCI in elderly population living in the community in North China. A total of 3136 participants entered the study. They were screened for hypertension, coronary heart disease (CHD), and cerebrovascular disease (CVD). Cognitive function was assessed with Mini-Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA). The diagnosis of MCI was made according to Petersen’s criteria. We investigated the relationship between vascular risk factors, potential protective factors and MCI. A total of 2511 (80%) participant belonged to normal group and 625 (20%) participants showed MCI. Multiple logistic regression analysis demonstrated that stroke and diabetes, but not hypertension or CHD was associated with MCI. Besides, exercise habit could lower the risk of MCI. Vascular Risk Factors, including stroke and diabetes, rather than hypertension and CHD are independent risk factors of MCI. Involvement in physical activities seems to reduce the risk of MCI.

Most patients with mild cognitive impairment (MCI) are thought to be in an early stage of Alzheimer’s disease (AD). Resting-state functional magnetic resonance imaging reflects spontaneous brain activity and/or the endogenous/background neurophysiological process of the human brain. Regional homogeneity (ReHo) rapidly maps regional brain activity across the whole brain. In the present study, we used the ReHo index to explore whole brain spontaneous activity pattern in MCI. Our results showed that MCI subjects displayed an increased ReHo index in the paracentral lobe, precuneus, and postcentral and a decreased ReHo index in the medial temporal gyrus and hippocampus. Impairments in the medial temporal gyrus and hippocampus may serve as important markers distinguishing MCI from healthy aging. Moreover, the increased ReHo index observed in the postcentral and paracentral lobes might indicate compensation for the cognitive function losses in individuals with MCI.