Echinacoside Alleviates Cognitive Impairment in Cerebral Ischemia Rats through α 7nAChR-Induced Autophagy.

OBJECTIVES: To evaluate the effect of echinacoside (ECH) on cognitive dysfunction in post cerebral stroke model rats. METHODS: The post stroke cognitive impairment rat model was created by occlusion of the transient middle cerebral artery (MCAO). The rats were randomly divided into 3 groups by a random number table: the sham group (sham operation), the MCAO group (received operation for focal cerebral ischemia), and the ECH group (received operation for focal cerebral ischemia and ECH 50 mg/kg per day), with 6 rats in each group. The infarct volume and spatial learning were evaluated by triphenyl tetrazolium chloride staining and Morris water maze. The expression of α7nAChR in the hippocampus was detected by immunohistochemistry. The contents of acetylcholine (ACh), malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), activities of choline acetyltransferase (ChAT), acetylcholinesterase (AChE), and catalase (CAT) were evaluated by enzyme linked immunosorbent assay. The neural apoptosis and autophagy were determined by TUNEL staining and LC3 staining, respectively. RESULTS: ECH significantly lessened the brain infarct volume and ameliorated neurological deficit in infarct volume and water content (both P<0.01). Compared with MCAO rats, administration of ECH revealed shorter escape latency and long retention time at 7, 14 and 28 days (all P<0.01), increased the α7nAChR protein expression, ACh content, and ChAT activity, and decreased AChE activity in MCAO rats (all P<0.01). ECH significantly decreased MDA content and increased the GSH content, SOD, and CAT activities compared with MCAO rats (all P<0.05). ECH suppressed neuronal apoptosis by reducing TUNEL-positive cells and also enhanced autophagy in MCAO rats (all P<0.01). CONCLUSION: ECH treatment helped improve cognitive impairment by attenuating neurological damage and enhancing autophagy in MCAO rats.

Association between plasma homocysteine levels and pancreatic islet beta-cell function in the patients with type 2 diabetes mellitus: a cross-sectional study from China.

BACKGROUND: This study sought to investigate the association between plasma homocysteine (HCY) levels and pancreatic islet beta-cell function in type 2 diabetes mellitus (T2DM) patients. METHODS: 430 hospitalized T2DM patients were enrolled in this cross-sectional study from December 2013 to December 2016. All participants were requested to complete a detailed questionnaire and undergo anthropometric measurements. Blood samples were collected from all participants. A 75-g oral glucose tolerance test (OGTT) was performed to diagnose T2DM in each individual, and an insulin releasing test (IRT) was used to calculate selected parameters for glucose, insulin, and C-peptide. Linear correlation and multivariate regression analyses were performed to assess the association between serum HCY concentration and these parameters. RESULTS: Patients were divided into the following subgroups based on quartiles of serum HCY levels: Group Q1: <17.03 µmol/L; Group Q2: 17.03-19.50 µmol/L; Group Q3: 19.5-24.7 µmol/L; and Group Q4: >24.7 µmol/L. The levels of fasting blood glucose (FBG), 2 h postprandial blood glucose (2hPBG), glycated hemoglobin A1c (HbA1c), fasting C-peptide and fasting insulin increased significantly as HCY levels increased (P<0.05). The area under the curves (AUCs) of serum glucose and insulin in IRT increased significantly and that of serum C-peptide decreased as HCY levels increased (P<0.05). The levels of Homeostasis Model Assessment-ß (HOMA-ß), Modified Beta-cell function Index (MBCI), Disposal Index (DI), C-peptide immunoreactivity (CPR), Insulinogenic Index 30 (IGI 30), and Secretory Units of Islets in Transplantation (SUIT) decreased as HCY levels increased. An inverse linear correlation was found between HOMA-ß, MBCI, DI, CPR, IGI 30, SUIT 0 h, and HCY plasma concentration (R2, 0.539, 0.569, 0.500, 0.676, 0.579, and 0.588, respectively; P<0.001), and this association was independent of many confounders, such as age, gender, body mass index, glucose and insulin levels, and HbA1c. CONCLUSIONS: Serum HCY levels were inversely related to the parameters for pancreatic islet beta-cell function. Thus, the insulin releasing function of beta cells in the pancreas can be well elucidated by plasma HCY concentration.

PolyMet-HA nanocomplexs regulates glucose uptake by inhibiting SHIP2 activity.

Metformin, the first-line drug to treat type 2 diabetes, inhibits mitochondrial glycerolphosphate dehydrogenase in the liver to suppress gluconeogenesis. The major adverse effects caused by metformin were lactic acidosis and gastrointestinal discomfort. Therefore, there is need to develop a strategy with excellent permeability and appropriate retention effects.In this study, we synthesized a simple and biocompatible PolyMetformin (denoted as PolyMet) through conjugation of PEI1.8K with dicyandiamide, and then formed PolyMet-hyaluronic acid (HA) nanocomplexs by electrostatic self-assembly of the polycationic PolyMet and polyanionic hyaluronic acid (HA). Similar to metformin, the PolyMet-HA nanocomplexs could reduce the catalytic activity of the recombinant SHIP2 phosphatase domain in vitro. In SHIP2-overexpressing myotubes, PolyMet-HA nanocomplexes ameliorated glucose uptake by downregulating glucose transporter 4 endocytosis. PolyMet-HA nanocomplexes also could restore Akt signaling and protect the podocyte from apoptosis induced by SHIP2 overexpression. In essence, the PolyMet-HA nanocomplexes act similarly to metformin and increase glucose uptake, and maybe have a potential role in the treatment of type 2 diabetes.

Circular RNA expression profiles and features in NAFLD mice: a study using RNA-seq data.

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is primarily characterized by the hepatic cholesterol accumulation. Circular RNA (circRNA), one of noncoding RNA, involves in many liver diseases progression. However, no recent studies on circRNA expression profiles in NAFLD have been reported previously. METHODS: A NAFLD mouse model was constructed by providing high-fat diet (HFD) for 32 weeks. The circRNAs expression profile in normal mice and NAFLD mice were determined using high-output RNA sequencing method and bioinformatics methods, while the differentially expressed circRNAs were confirmed using Sanger sequencing and qRT-PCR. The circRNA-miRNA network was also predicted. The biological functions of circRNAs were annotated by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). RESULTS: The results demonstrated the successful construction of NAFLD mice model by immunohistology and serology assay. In total, 93 dysregulated circRNAs were observed, including 57 upregulated circRNAs and 36 downregulated circRNAs, in the NAFLD group. The circRNA-miRNA network revealed the complex interaction between circRNAs and its potential miRNA targets in NAFLD. The characteristic of tissue-specific expression in circRNA was demonstrated. The differentially expressed circRNAs with important biological function were also annotated using GO and KEGG. Both DDAH1 and VAV3 genes were found to be associated with the NAFLD development. CONCLUSIONS: Taken together, this study demonstrated the circRNAs expression profile and features in NAFLD, which may provide potential biological markers for the pathogenesis of NAFLD.

MicroRNA expression profiling of nicotine-treated human periodontal ligament cells.

Cigarette smoking is a lifestyle-related risk factor involved in the causation and progression of periodontal disease. Nicotine is a key toxic component of tobacco. However, the mechanisms underlying nicotine-induced periodontitis have not yet been fully elucidated. The present study investigated the microRNA (miRNA) expression profile of human periodontal ligament cells (PDLCs) treated with nicotine. Using differential analysis of miRNA array data, several differentially expressed miRNAs were identified in nicotine-treated PDLCs. Quantitative real-time PCR was employed to verify the accuracy of the miRNA array, and the targets of these dysregulated miRNAs were further analyzed. Function and pathway enrichment of differentially expressed miRNAs suggested that several important signaling pathways, such as the Toll-like receptor signaling pathway, nicotine addiction, the transforming growth factor-beta signaling pathway, and the hypoxia inducible factor-1 signaling pathway, are potentially responsible for nicotine-induced periodontitis. This study has helped to clarify the epigenetic mechanisms of nicotine-induced periodontitis, highlighting novel biomarkers and therapeutic targets.

MicroRNA expression profile of human periodontal ligament cells under the influence of Porphyromonas gingivalis LPS.

Periodontitis is a chronic inflammatory disease which is caused by bacterial infection and leads to the destruction of periodontal tissues and resorption of alveolar bone. Thus, special attention should be paid to the mechanism under lipopolysaccharide (LPS)-induced periodontitis because LPS is the major cause of periodontitis. However, to date, miRNA expression in the LPS-induced periodontitis has not been well characterized. In this study, we investigated miRNA expression patterns in LPS-treated periodontal ligament cells (PDLCs). Through miRNA array and differential analysis, 22 up-regulated miRNAs and 28 down-regulated miRNAs in LPS-treated PDLCs were identified. Seven randomly selected up-regulated (miR-21-5p, 498, 548a-5p) and down-regulated (miR-495-3p, 539-5p, 34c-3p and 7a-2-3p) miRNAs were examined by qRT-PCR, and the results proved the accuracy of the miRNA array. Moreover, targets of these deregulated miRNAs were analysed using the miRWalk database. Database for Annotation, Visualization and Integration Discovery software were performed to analyse the Gene Ontology and Kyoto Encyclopaedia of Genes and Genomes pathway of differential expression miRNAs, and the results shown that Toll-like receptor signalling pathway, cAMP signalling pathway, transforming growth factor-beta signalling pathway, mitogen-activated protein kinase (MAPK) signalling pathway and other pathways were involved in the molecular mechanisms underlying LPS-induced periodontitis. In conclusion, this study provides clues for enhancing our understanding of the mechanisms and roles of miRNAs as key regulators of LPS-induced periodontitis.

[The relationship between c-fos gene and filamentous actin cytoskeleton in MG-63 osteoblasts under cyclic tensile stress].

OBJECTIVE: To investigate the relationship between c-fos gene and filamentous actin (F-actin) in MG-63 osteoblasts under cyclic tensile stress. METHODS: MG-63 osteoblasts were subjected to cyclic tensile stress (0.5 Hz, 2 000 microstrain) for 3, 6, and 12 h. The changes of c-fos gene were investigated by fluorescent quantitation polymerase chain reaction. Then the best loading time group was screened as the experimental group compared with 0 h group. The changes of F-actin and c-fos were investigated with or without cytochalasin D treatment. RESULTS: Cyclic tensile stress induced high expression of c-fos mRNA, and peaked at 3 h. After loading, F-actin had a structure reorganization, but had no change in expression. After cytochalasin D treatment, the formation of stress fibers and the fluorescence intensity of F-actin cytoskeleton significantly reduced, meanwhile the c-fos mRNA expression was inhibited. CONCLUSION: After loading, there is only structure reorganization for F-actin, and the expression has not any change. That means the remodeling F-actin is the existing one. F-actin reorganization is an important part in c-fos gene expression induced by stress.