miR-4645-3p attenuates podocyte injury and mitochondrial dysfunction in diabetic kidney disease by targeting Cdk5.

Podocyte injury plays a critical role in the progression of diabetic kidney disease (DKD), but the underlying cellular and molecular mechanisms remain poorly understanding. MicroRNAs (miRNAs) can disrupt gene expression by inducing translation inhibition and mRNA degradation, and recent evidence has shown that miRNAs may play a key role in many kidney diseases. In this study, we identified miR-4645-3p by global transcriptome expression profiling as one of the major downregulated miRNAs in high glucose-cultured podocytes. Moreover, whether DKD patients or STZ-induced diabetic mice, expression of miR-4645-3p was also significantly decreased in kidney. In the podocytes cultured by normal glucose, inhibition of miR-4645-3p expression promoted mitochondrial damage and podocyte apoptosis. In the podocytes cultured by high glucose (30 mM glucose), overexpression of miR-4645-3p significantly attenuated mitochondrial dysfunction and podocyte apoptosis induced by high glucose. Furthermore, we found that miR-4645-3p exerted protective roles by targeting Cdk5 inhibition. In vitro, miR-4645-3p obviously antagonized podocyte injury by inhibiting overexpression of Cdk5. In vivo of diabetic mice, podocyte injury, proteinuria, and impaired renal function were all effectively ameliorated by treatment with exogenous miR-4645-3p. Collectively, these findings demonstrate that miR-4645-3p can attenuate podocyte injury and mitochondrial dysfunction in DKD by targeting Cdk5. Sustaining the expression of miR-4645-3p in podocytes may be a novel strategy to treat DKD.

Association between urinary polycyclic aromatic hydrocarbons and risk of metabolic associated fatty liver disease.

OBJECTIVE: To investigate the effect of urinary PAHs on MAFLD. METHODS: The study included 3,136 adults from the National Health and Nutrition Examination Survey (NHANES) conducted between 2009 and 2016. Among them, 1,056 participants were diagnosed with MAFLD and were designated as the case group. The analysis of the relationship between monohydroxy metabolites of seven PAHs in urine and MAFLD was carried out using logistic regression and Bayesian kernel regression (BKMR) models. RESULTS: In single-pollutant models, the concentration of 2-hydroxynaphthalene (2-OHNAP) was positively correlated with MAFLD (OR = 1.47, 95% CI 1.18, 1.84), whereas 3-hydroxyfluorene (3-OHFLU) and 1-hydroxypyrene (1-OHPYR) demonstrated a negative correlation with MAFLD (OR = 0.59, 95% CI 0.48 0.73; OR = 0.70, 95% CI 0.55, 0.89). Conversely, in multi-pollutant models, 2-OHNAP, 2-hydroxyfluorene (2-OHFLU), 2-hydroxyphenanthrene, and 3-hydroxyphenanthrene (2&3-OHPHE) displayed positive correlations with MAFLD (OR = 6.17, 95% CI 3.15, 12.07; OR = 2.59, 95% CI 1.37, 4.89). However, 3-OHFLU and 1-OHPYR continued to exhibit negative correlations with MAFLD (OR = 0.09, 95% CI 0.05, 0.15; OR = 0.62, 95% CI 0.43, 0.88). Notably, the BKMR analysis mixtures approach did not indicate a significant joint effect of multiple PAHs on MAFLD, but identified interactions between 3-OHFLU and 2-OHFLU, 1-OHPYR and 2-OHFLU, and 1-OHPYR and 3-OHFLU. CONCLUSION: No significant association was found between mixed PAHs exposure and the risk of MAFLD. However, interactions were observed between 3-OHFLU and 2-OHFLU. Both 2-OHFLU and 2&3-OHPHE exposure are significant risk factors for MAFLD, whereas 3-OHFLU is a key protective factor for the disease.

Retraction Note to: MicroRNA-322 Cluster Promotes Tau Phosphorylation via Targeting Brain-Derived Neurotrophic Factor.

The Editors have retracted this article [1] following an investigation conducted by the journal. After publication concerns were raised regarding interpretation of the data presented in Fig. 4. The Editors requested additional data and clarification to confirm interpretation of data results. After further review, the Editors found that the additional data were not adequate to support the conclusion of the article and that P-values for the additional data were based on improper statistical analyses. With more appropriate statistical analysis, the reported effects for miR-322 and BDNF were not statistically significant. Dr. Chichu Xie agrees to this retraction. None of the other authors have responded to any correspondence from the publisher about this retraction.

Evaluation of the diagnostic value of peripheral BDNF levels for Alzheimer's disease and mild cognitive impairment: results of a meta-analysis.

Deregulation of brain-derived neurotrophic factor (BDNF) is a possible contributor to the pathology and symptoms of Alzheimer's disease (AD). Most studies support an association between the dysfunction of BDNF and the pathogenesis of AD. This study aimed to evaluate the diagnostic value of peripheral BDNF levels in patients with AD and mild cognitive impairment (MCI) using meta-analytic techniques. A systematic search of the MEDLINE, EMBASE, ISI Web of Science, and the Cochrane Central database was performed and 34 eligible articles were identified for inclusion in the meta-analysis. Random-effects meta-analysis showed that AD patients had significantly decreased levels of peripheral BDNF compared with healthy control (HC) subjects (Hedges' g = - 0.725, 95% CI = -1.06 to - 0.39, p < 0.01). MCI patients showed a same trend with decreased BDNF levels compared with HC subjects (Hedges' g = - 0.296, 95% CI = - 0.57 to - 0.02, p < 0.01). Significant differences were found between AD and MCI subjects in peripheral BDNF levels (Hedges' g = - 0.462, 95% CI = - 0.95 to 0.03, p < 0.01). However, the ROC curve analysis revealed that the peripheral BDNF levels may not be an optimal biomarker potentially for AD and MCI diagnosis with a lower AUC (AD: 0.707; MCI: 0.573), less sensitivity (AD: 66.67%; MCI: 50.00%) and poor specificity (AD: 93.33%; MCI: 83.33%). These results suggested that AD or MCI is accompanied by reduction of peripheral BDNF, but the levels of circulating BDNF may not be suitable as a diagnostic marker for AD and MCI.

GPER stabilizes F-actin cytoskeleton and activates TAZ via PLCß-PKC and Rho/ROCK-LIMK-Cofilin pathway.

Actin is a highly abundant cytoskeletal protein that is essential for all eukaryotic cells and participates in many structural and functional roles. It has long been noted that estrogen affects cellular morphology. However, recent studies observed that both estrogen and tamoxifen induce a remarkable cytoskeletal remodeling independent of ER. In addition to ER, G protein-coupled estrogen receptor 1 (GPER, also known as GPR30) also binds to estrogen with high affinity and mediates intracellular estrogenic signaling. Here, we show that activation of GPER by its specific agonist G-1 induces re-organization of F-actin cytoskeleton. We further demonstrate that GPER acts through PLCß-PKC and Rho/ROCK-LIMK-Cofilin pathway, which are upstream regulators of F-actin cytoskeleton assembly, thereby enhancing TAZ nuclear localization and activation. Furthermore, we find that LIMK1/2 is critical for GPER activation-induced breast cancer cell migration. Together, our results suggest that GPER mediates G-1-induced cytoskeleton assembly and GPER promotes breast cancer cell migration via PLCß-PKC and Rho/ROCK-LIMK-Cofilin pathway.

MicroRNA-322 Cluster Promotes Tau Phosphorylation via Targeting Brain-Derived Neurotrophic Factor.

Brain-derived neurotrophic factor (BDNF) is a crucial regulator to support synaptic plasticity and neuronal survival, its significant decrease is a pathophysiological hallmark in Alzheimer's disease (AD) brains and accounts for poor prognosis. MicroRNAs (miRNAs) interfere with the translation of target mRNAs and control a variety of physiological and pathological processes. MiR-322 is the rodent homologue of human miR-424, it is involved in the modulation of cell differentiation, proliferation, apoptosis and metabolic activities in diverse tissues and organs. However, the roles and potential mechanisms of miR-322 remain elusive in AD pathogenesis. Here we observed miR-322 is significantly increased along with BDNF decrease in AD mouse brain. Bioinformatics prediction implicated that BDNF 3'-untranslated region (3'-UTR) possesses the putative target sequence of miR-322. Luciferase reporter assay identified that miR-322 can directly conjugate to BDNF 3'-UTR. The functional research showed that MiR-322 input deregulates BDNF expression at either mRNA or protein levels, whereas miR-322 silence restores BDNF expression in vitro. Furthermore, we found miR-322 promotes Tau phosphorylation via negatively controlling BDNF-TrkB receptor activation, otherwise MiR-322 silence restores TrkB activation and attenuates tau phosphorylation. Collectively, this study demonstrated a novel miRNA-dependent manner of BDNF degradation in AD pathogenesis, it may drive a miRNAs- or BDNF based therapeutic strategies against Alzheimer's disease.

SUMOylation at K340 inhibits tau degradation through deregulating its phosphorylation and ubiquitination.

Intracellular accumulation of the abnormally modified tau is hallmark pathology of Alzheimer's disease (AD), but the mechanism leading to tau aggregation is not fully characterized. Here, we studied the effects of tau SUMOylation on its phosphorylation, ubiquitination, and degradation. We show that tau SUMOylation induces tau hyperphosphorylation at multiple AD-associated sites, whereas site-specific mutagenesis of tau at K340R (the SUMOylation site) or simultaneous inhibition of tau SUMOylation by ginkgolic acid abolishes the effect of small ubiquitin-like modifier protein 1 (SUMO-1). Conversely, tau hyperphosphorylation promotes its SUMOylation; the latter in turn inhibits tau degradation with reduction of solubility and ubiquitination of tau proteins. Furthermore, the enhanced SUMO-immunoreactivity, costained with the hyperphosphorylated tau, is detected in cerebral cortex of the AD brains, and ß-amyloid exposure of rat primary hippocampal neurons induces a dose-dependent SUMOylation of the hyperphosphorylated tau. Our findings suggest that tau SUMOylation reciprocally stimulates its phosphorylation and inhibits the ubiquitination-mediated tau degradation, which provides a new insight into the AD-like tau accumulation.

miR-154 suppresses colorectal cancer cell growth and motility by targeting TLR2.

MicroRNAs play critical roles in the development and progression of colorectal cancer (CRC). miR-154 acts as a tumor suppressor in several tumors; however, its role in CRC is poorly understood. Herein, we found that miR-154 was decreased in CRC tissues and cell lines. Ectopic expression of miR-154 remarkably suppressed cell proliferation and colony formation, migration and invasion in CRC cells. The toll-like receptor 2 (TLR2) was found to be a direct target of miR-154 in CRC cells. Inhibition of TLR2 performed similar effects with miR-154 overexpression on CRC cells, and overexpression of TLR2 could significantly reverse the tumor suppressive effects of miR-154 on CRC cells. This study suggests an essential role for miR-154 in CRC.

Exploring the mechanism of Jinlida granules against type 2 diabetes mellitus by an integrative pharmacology strategy.

Jinlida granule (JLD) is a Traditional Chinese Medicine (TCM) formula used for the treatment of type 2 diabetes mellitus (T2DM). However, the mechanism of JLD treatment for T2DM is not fully revealed. In this study, we explored the mechanism of JLD against T2DM by an integrative pharmacology strategy. Active components and corresponding targets were retrieved from Traditional Chinese Medicine System Pharmacology (TCMSP), SwissADME and Bioinformatics Analysis Tool for Molecular Mechanisms of Traditional Chinese Medicine Database (BATMAN-TCM) database. T2DM-related targets were obtained from Drugbank and Genecards databases. The protein-protein interaction (PPI) network was constructed and analyzed with STRING (Search Toll for the Retrieval of Interacting Genes/proteins) and Cytoscape to get the key targets. Then, Gene Ontology (GO) and Kyoto Encyclopedia of Gene and Genomes (KEGG) enrichment analyses were performed with the Database for Annotation, Visualization and Integrated Discovery (DAVID). Lastly, the binding capacities and reliability between potential active components and the targets were verified with molecular docking and molecular dynamics simulation. In total, 185 active components and 337 targets of JLD were obtained. 317 targets overlapped with T2DM-related targets. RAC-alpha serine/threonine-protein kinase (AKT1), tumor necrosis factor (TNF), interleukin-6 (IL-6), cellular tumor antigen p53 (TP53), prostaglandin G/H synthase 2 (PTGS2), Caspase-3 (CASP3) and signal transducer and activator of transcription 3 (STAT3) were identified as seven key targets by the topological analysis of the PPI network. GO and KEGG enrichment analyses showed that the effects were primarily associated with gene expression, signal transduction, apoptosis and inflammation. The pathways were mainly enriched in PI3K-AKT signaling pathway and AGE-RAGE signaling pathway in diabetic complications. Molecular docking and molecular dynamics simulation verified the good binding affinity between the key components and targets. The predicted results may provide a theoretical basis for drug screening of JLD and a new insight for the therapeutic effect of JLD on T2DM.

Association between circulating levels of unsaturated fatty acids and risk for prediabetes in the NHANES 2003-2004 and 2011-2012.

AIMS: This study aimed to investigate the association between serum levels of common and uncommon unsaturated fatty acids and prediabetes risk. METHODS: Data were collected from the National Health and Nutrition Examination Survey for 2003-2004 and 2011-2012. Weighted proportional and multivariate logistic regression analyses were performed to assess the association of serum PUFAs and MUFAs with prediabetes risk after adjusting for potential confounders. RESULTS: A total of 3575 individuals were enrolled in this study. Serum levels of PUFAs EPA (20:5 n3) and GLA (18:3 n6) were associated with increased prediabetes risk (EPA (20:5 n3): OR = 1.878, 95% CI: 1.177-2.996, Ptrend = 0.002; GLA (18:3 n6): 1.702, 95% CI: 1.140-2.541, Ptrend = 0.016). The MUFAs PA (16:1 n7) and EA (20:1 n9) were associated with the risk of prediabetes (OR in quintile5: PA (16:1 n7): 1.780, 95% CI: 1.056-3.001, Ptrend = 0.003; EA (20:1 n9): 0.587, 95% CI: 0.347-0.994, Ptrend = 0.010). Moreover, nonlinear analysis revealed that serum levels of EPA (20:5 n3) and EA (20:1 n-9) were nonlinearly associated with prediabetes risk. CONCLUSION: Some serum n-3 PUFAs are positively associated with prediabetes, several serum n-6 PUFAs are inversely associated with prediabetes. Regulating individual serum USFA levels may help prevent prediabetes, thereby providing evidence for clinical and nutritional practices.

Oestrogen receptor α agonist improved long-term ovariectomy-induced spatial cognition deficit in young rats.

Ovariectomy is known as 'surgical menopause' with decreased levels of oestrogen in female rodents and its reported risks and adverse effects include cognitive impairment. In the brain, oestrogen exerts effects through its receptors, oestrogen receptor α (ERα) and ß (ERß). However, the role of ERα or ERß in ovariectomy-induced cognitive impairment needs further investigation. Here, we observed that bilaterally ovariectomized 3-month-old rats showed obvious spatial learning and memory deficits in the Morris water maze with significant loss of neurons and synapses in the hippocampus. In addition to the rapid decline in serum oestradiol levels, the expression of ERα, but not ERß, was decreased in the hippocampus starting 1 wk after ovariectomy. Prompt 4,4',4″-(4-propyl-[1H]-pyrazole-1,3,5-triyl) trisphenol (PPT) treatment (1 mg/kg.d), an agonist of ERα, improved the spatial learning and memory ability of ovariectomized rats and rescued ovariectomy-induced neuron loss by up-regulating the level of BCLxl, an important anti-apoptosis protein. Furthermore, PPT treatment also improved ovariectomy-induced hippocampal synapse loss and up-regulated the levels of synaptic proteins (synapsin I, NR2A and GluR1) and the activates of CaMK Πα, ERK and Akt. Thus, these results demonstrated that ERα plays an important role in neuroprotection and that prompt ERα rescue is effective to improve hippocampal-dependent cognition deficit after long-term ovariectomy.

Nomogram for prediction of diabetic retinopathy in patients with type 2 diabetes mellitus: A retrospective study.

OBJECTIVE: To develop a nomogram for the risk of diabetic retinopathy (DR) among type 2 diabetes mellitus (T2DM). METHODS: Questionnaires, physical examinations and biochemical tests were performed on 5900 T2DM patients in the Second Hospital of Shijiazhuang. The least absolute shrinkage and selection operator regression was used to optimize feature selection, and the importance of selected features was analyzed by random forest. Logistic regression was performed with selected features, and the nomogram was established based on the results. The Harrell's C-statistic, bootstrap-corrected C-statistic, area under curve (AUC), calibration curve, decision curve analysis (DCA) and clinical impact curve (CIC) were used to validate the discrimination, calibration and clinical usefulness of the nomogram, and further assessment was running by external validation. RESULTS: Predictors included duration of diabetes, diabetic neuropathy, diabetic kidney disease, diabetic foot, hyperlipidemia, hypoglycemic drugs, glycated albumin, Lactate dehydrogenase. The model displayed medium predictive power with a Harrell's C-statistic of 0.820, bootstrap-corrected C-statistic of 0.813 and AUC of 0.820 in the training set, and which was respectively 0.842, 0.835 and 0.842 in the validation set. The calibration curve displayed good agreement (P > 0.05). The DCA and CIC showed that the nomogram could be applied clinically if the risk threshold is between 2 % and 75 % and 2 %-88 % in validation set. CONCLUSIONS: This nomogram incorporating 8 features is useful to predict the risk of DR in T2DM patients.

Identification of a novel CACNA1F mutation in a Chinese family with CORDX3.

BACKGROUND: X-linked cone-rod dystrophy (CORDX) is one form of inherited retinal disorders (IRDs) characterized by progressive dysfunction of photoreceptor. Three types of CORDX were reported and CACNA1F gene defect can cause CORDX3. The aim of this study was to investigate the pathogenic variant in a Chinese family with IRD. METHODS: The two affected subjects including the proband and his elder sister underwent ophthalmic examinations. Whole exome sequencing (WES) was performed in the proband at first, then co-segregation analysis was performed in the family by Sanger sequencing. Minigene approach was used to verify the effect of the mutation on the splicing of CACNA1F. X-chromosomal inactivation assay was performed to evaluate the inactivation patterns of the female carriers. RESULTS: The ophthalmic examination results of the proband fit the clinical description of CORDX3, and the female patient presented with only mild symptoms due to mildly skewed X-chromosomal inactivation (ratio 67: 33). Molecular genetic testing identified a novel splice-site mutation c.3847-2A > G in CACNA1F (NM_005183.4) gene in the patients, which inherited from their asymptomatic mother. Minigene approach confirmed that c.3847-2A > G could affect the splicing of CACNA1F. CONCLUSION: Our study identified a novel splice-site mutation in the CACNA1F gene, which expanded the mutational spectrum of CACNA1F-releated diseases and demonstrated the importance of combining clinical and genetic testing in the diagnosis of IRDs.

Crosstalk Between Gut Microflora and Vitamin D Receptor SNPs Are Associated with the Risk of Amnestic Mild Cognitive Impairment in a Chinese Elderly Population.

BACKGROUND: The interactions between environmental factors and genetic variants have been implicated in the pathogenesis of Alzheimer's disease (AD). The altered gut microbiota (GM) and vitamin D deficiency are closely associated with the higher risk of AD. OBJECTIVE: This study was performed to evaluate whether the crosstalk between GM and single nucleotide polymorphisms (SNPs) of vitamin D receptor (VDR) or vitamin D binding protein (VDBP) have a link with the risk of amnestic mild cognitive impairment (aMCI) in the Chinese elderly population. METHODS: A total of 171 aMCI patients and 261 cognitive normal controls (NC) were enrolled in this study. Six tag SNPs of VDR and VDBP were genotyped by PCR-RFLP. The serum levels of vitamin D, Aß1-42, and p-tau (181P) were determined by using of ELISA kits. The alterations in the GM were analyzed by full-length 16S ribosomal RNA (rRNA) gene sequencing. RESULTS: The frequencies of AG genotype and A allele of VDR rs1544410 in aMCI group were significantly higher than that in NC group (genotype: p = 0.002, allele: p = 0.003). Patients with aMCI showed an abnormal GM composition compared with NC group. Interestingly, significant differences in GM composition were found between aMCI and NC group among individuals with AG genotype, as well as between individuals with AG and GG genotype of VDR rs1544410 among patients with aMCI. CONCLUSION: These results implicated that the crosstalk between gut microflora and vitamin D receptor variants are associated with the risk of aMCI in Chinese elderly population.

Identification of Maturity-Onset Diabetes of the Young Caused by Mutation in FOXM1 via Whole-Exome Sequencing in Northern China.

Diabetes mellitus is a highly heterogeneous disorder encompassing different types with particular clinical manifestations, while maturity-onset diabetes of the young (MODY) is an early-onset monogenenic diabetes. Most genetic predisposition of MODY has been identified in European and American populations. A large number of Chinese individuals are misdiagnosed due to defects of unknown genes. In this study, we analyzed the genetic and clinical characteristics of the Northern China. A total of 200 diabetic patients, including 10 suspected MODY subjects, were enrolled, and the mutational analysis of monogenic genes was performed by whole-exome sequencing and confirmed by familial information and Sanger sequencing. We found that clinical features and genetic characteristics have varied widely between MODY and other diabetic subjects in Northern China. FOXM1, a key molecule in the proliferation of pancreatic ß-cells, has a rare mutation rs535471991, which leads to instability within the phosphorylated domain that impairs its function. Our findings indicate that FOXM1 may play a critical role in MODY, which could reduce the misdiagnose rate and provide promising therapy for MODY patients.

Elevation of Peripheral BDNF Promoter Methylation Predicts Conversion from Amnestic Mild Cognitive Impairment to Alzheimer's Disease: A 5-Year Longitudinal Study.

Epigenetic aberrations have been identified as biomarkers to predict the risk of Alzheimer's disease (AD). This study aimed to evaluate whether altered DNA methylation status of BDNF promoter could be used as potential epigenetic biomarkers for predicting the progression from amnestic mild cognitive impairment (aMCI) to AD. A total of 506 aMCI patients and 728 cognitively normal controls were recruited in the cross-sectional analyses. Patients (n = 458) from aMCI cohort were classified into two groups after 5-year follow-up: aMCI-stable group (n = 330) and AD-conversion group (n = 128). DNA methylation of BDNF promoter was detected by bisulfite-PCR amplification and pyrosequencing. The DNA methylation levels of CpG1 and CpG2 in promoter I and CpG5 and CpG6 in promoter IV of BDNF gene were significantly higher in the aMCI group than in the control group at baseline and also were increased in the conversion group compared with the non-conversion group at 5-year follow up time point. CpG5 in BDNF promoter IV had the highest AUC of 0.910 (95% CI: 0.817-0.983, p < 0.05). Kaplan-Meier analysis showed a significant AD conversion propensity for aMCI patients with high methylation levels of CpG5 (HR = 1.96, 95% CI: 1.07-2.98, p < 0.001). Multivariate Cox regression analysis revealed elevated methylation status of CpG5 was a significant independent predictor for AD conversion (HR = 3.51, p = 0.013). These results suggest that elevation of peripheral BDNF promoter methylation might be used as potential epigenetic biomarkers for predicting the conversion from aMCI to AD.

DNA Methylation and Tag SNPs of the BDNF Gene in Conversion of Amnestic Mild Cognitive Impairment into Alzheimer's Disease: A Cross-Sectional Cohort Study.

Alzheimer's disease (AD) is a complex multifactorial disease influenced by both genetic and epigenetic factors. This study was aimed to evaluate the interaction between brain-derived neurotrophic factor (BDNF) promoter methylation status and tag single nucleotide polymorphisms (tag SNPs) on amnestic mild cognitive impairment (aMCI) and its conversion to AD. A total of 506 aMCI patients and 728 cognitive normal controls were included in the cross-sectional analysis. Patients (n = 458) from aMCI cohort were selected in the 5-year longitudinal study and classified into two groups: aMCI-stable group (n = 330) and AD-conversion group (n = 128). BDNF promoter methylation was detected by bisulfite-PCR amplification and pyrosequencing. Seven tag SNPs were genotyped by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Elevation of BDNF promoter methylation status was associated with aMCI and AD conversion. The higher methylation levels at CpG5 site showed significant main interactive effects between group and time (F = 8.827, p = 0.005). Genetic analysis revealed rs2030324 and rs6265 were associated with aMCI and rs6265 was associated with AD conversion. The interaction between DNA methylation of CpG5 and AA genotype of rs6265 had a risk role in the development of aMCI (p = 0.019, OR = 1.233, 95% CI: 1.117-1.303) and its progression to AD (p = 0.003, OR = 1.399, 95% CI: 1.198-1.477). The interactions between DNA methylation (CpG5) of the BDNF gene promoter and the tag SNP (rs6265) play important roles in the etiology of aMCI and its conversion to AD.

Upregulation of miR-195 accelerates oxidative stress-induced retinal endothelial cell injury by targeting mitofusin 2 in diabetic rats.

This study was performed to investigate the oxidative stress-induced miRNA changes in relation to pathogenesis of diabetic retinopathy (DR) and to establish a functional link between miRNAs and oxidative stress-induced retinal endothelial cell injury. Our results demonstrated that oxidative stress could induce alterations of miRNA expression profile, including up-regulation of miR-195 in the diabetic retina or cultured HMRECs after exposed to H2O2 or HG (P < 0.05). Oxidative stress also resulted in a significant reduction of MFN2 expression in diabetic retina or HMRECs (P < 0.05). Overexpression of miR-195 reduced MFN2 protein levels, and induced tube formation and increased permeability of diabetic retinal vasculature. The luciferase reporter assay confirmed that miR-195 binds to the 3' -untranslated region (3'-UTR) of MFN2 mRNA. This study suggested that miR-195 played a critical role in oxidative stress-induced retinal endothelial cell injury by targeting MFN2 in diabetic rats.

Increased Serum miR-206 Level Predicts Conversion from Amnestic Mild Cognitive Impairment to Alzheimer's Disease: A 5-Year Follow-up Study.

Evidence suggests that individuals with amnestic mild cognitive impairment (aMCI) tend to progress to probable Alzheimer's disease (AD) with aging. This study was performed to examine whether circulating miRNAs could be potential predictors for the progression of aMCI to AD. A total of 458 patients with aMCI were included in this study, and the clinical data were collected at two time points: the baseline and the follow-up assessment. These aMCI patients were classified into two groups after 5 years: aMCI-stable group (n = 330) and AD-conversion group (n = 128). The expression of miR-206 and miR-132 and the levels of BDNF and SIRT1 in serum were detected using a quantitative real-time RT-PCR (qPCR) and the ELISA method, respectively. Kaplan-Meier method (Log-rank test) was used for univariate survival analysis. Cox proportional hazard model was used to estimate the prognostic value of miRNAs in conversion from aMCI to AD. At the baseline, serum levels of miR-206 in aMCI-AD group were significantly elevated compared to aMCI-aMCI group and the same trend was found at 5-year follow-up time point as well. There were no significant differences in serum levels of miR-132 between the conversion and non-conversion group at both time points. Kaplan-Meier analysis showed significant correlation between AD conversion and higher serum levels of miR-206 for aMCI patients (HR = 3.60, 95% CI: 2.51- 5.36, p < 0.001). Multivariate Cox regression analysis revealed that serum miR-206 and its target BDNF were significant independent predictors for AD conversion (HR = 4.22, p < 0.001). These results suggested that increased serum miR-206 level might be a potential predictor of conversion from aMCI to AD.