Protopanaxadiol derivative DDPU improvesbehaviorand cognitive deficitin AD mice involving regulation of both ER stress and autophagy

OBJECTIVE To explore the potential effect and mechanisms of protopanaxadiol deriva.tive 1-(3,4-dimethoxyphenethyl)-3-(3-dehydroxyl-20(s)-protopa-naxadiol-3 b-yl)-urea(DDPU) in the treatment of Alzheimer disease.METHODS ELISA assay was performed in both HEK293-APPswe and CHO-APP cells to demonstrate the efficacy of DDPU in reducing Ab level.SH-SY5 Y,primary neurons and astrocyte cellswereused to study the regulation of DDPU against the signaling pathways involved in Aβ/ER-stress pathology.APP/PS1 transgenic mice wereusedto study the regulation of DDPU against ADL and cognitive deficits.APP/PS1 transgenic mice were randomly placed into three groups(n=10):The two 6-month transgenic groups were administrated with 30 mg·kg^(-1) DDPU or vehicle and the 6-month non-transgenic group was administrated with vehicle for 100 days by intraperitonealinjec.tion.After 100-day administration,nest construction assay and Morris water maze(MWM) assay were applied to evaluate the daily living activities and cognitive abilities of the mice with continuous DDPU treatment.Upon completion of behavior assays,mice were euthanized,and the brains were removed and bisected in mid-sagittal plane.The right hemispheres were frozen and stored at-80°C,and the left hemispheres were fixed in 4% paraformaldehyde.RESULTS DDPU effectively improved learning and memory impairments in APP/PS1 transgenic mice,and the underlying mechanisms have been inten.sively investigated.DDPU reduced Ab production by inhibiting the PERK/eIF2 a signaling-mediated BACE1 translation,while promoted Ab clearance as a PI3K inhibitor thus negatively regulating PI3K/AKT/mTOR signaling in promotion of autophagy.Moreover,DDPU also exhibited neuroprotective effect by attenuating ER stress.Therefore,all findings have clearly demonstrated the crosstalk between Ab and ER stress,and confirmed that targeting ER stress should be a potential target for innovative anti-AD drug development,while highlighted the potential of DDPU in the treatment of AD.

Effect of ATF3-deletion on apoptosis of cultured retinal ganglion cells

AIM：To investigate the effect of activating transcription factor-3（ATF3）-deletion on apoptosis of cultured retinal ganglion cells（RGCs）.METHODS：Three ATF3 siR NA（ATF3-rat-651, ATF3-rat-319, ATF3-rat-520） were constructed, and were transiently transfected into RGC-5 cells. Quantitative real-time polymerase chain reaction（PCR） was used to examine ATF3 expression and the most effective ATF3 siR NA was selected for further studies. Flow cytometry was applied to investigate the effects of ATF3 deletion on RGC-5 apoptosis under elevated hydrostatic pressure. Quantitative realtime PCR and Western blot were performed to validate differentially expressed genes and proteins in ATF3-knockdown RGC-5 cells.RESULTS：ATF3 specific siR NA effectively down-regulated ATF3 expression and significantly inhibited cell apoptosis in RGC-5 cells. Quantitative real-time PCR and Western blot confirmed that ATF3 knockdown remarkably decreased Jun-B and increased c-Jun at both m RNA and protein levels in RGC-5 cells.CONCLUSION：ATF/cA MP-response element-binding family of transcription factors may be involved in the development of glaucoma and could be novel treatment targets for glaucoma.

Inhibition on Apoptosis Induced by Elevated Hydrostatic Pressure in Retinal Ganglion Cell-5 via Laminin Upregulating β1-integrin/Focal Adhesion Kinase/Protein Kinase B Signaling Pathway

Background：Glaucoma is a progressive optic neuropathy characterized by degeneration of neurons due to loss of retinal ganglion cells （RGCs）.High intraocular pressure （HIOP）,the main risk factor,causes the optic nerve damage.However,the precise mechanism of HIOP-induced RGC death is not yet completely understood.This study was conducted to determine apoptosis of RGC-5 cells induced by elevated hydrostatic pressures,explore whether laminin is associated with apoptosis under pressure,whether laminin can protect RGCs from apoptosis and affirm the mechanism that regulates the process of RGCs survival.Methods：RGC-5 cells were exposed to 0,20,40,and 60 mmHg in a pressurized incubator for 6,12,and 24 h,respectively.The effect of elevated hydrostatic pressure on RGC-5 cells was measured by Annexin V-fluorescein isothiocyanate/propidium iodide staining,3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide assay,and Western blotting of cleaved caspase-3 protein.Location and expression oflaminin were detected by immunofluorescence.The expression of β 1-integrin,phosphorylation of focal adhesion kinase （FAK） and protein kinase B （PKB,or AKT） were investigated with real-time polymerase chain reaction and Western blotting analysis.Results：Elevated hydrostatic pressure induced apoptosis in cultured RGC-5 cells.Pressure with 40 mmHg for 24 h induced a maximum apoptosis.Laminin was declined in RGC-5 cells after exposing to 40 mmHg for 24 h.After pretreating with laminin,RGC-5 cells survived from elevated pressure.Furthermore,β1-integrin and phosphorylation of FAK and AKT were increased compared to 40 mmHg group.Conclusions：The data show apoptosis tendency of RGC-5 cells with elevated hydrostatic pressure.Laminin can protect RGC-5 cells against high pressure via β 1-integrin/FAK/AKT signaling pathway.These results suggest that the decreased laminin of RGC-5 cells might be responsible for apoptosis induced by elevated hydrostatic pressure,and laminin or activating β1-integrin/FAK/AKT pathway might be potential treatments to prevent RGC loss in glaucomatous optic neuropathy.

套管支持技术用于超声内镜的置入

Introduction Over the last three decades,endoscopic ultrasonography(EUS)and EUS-guided fine-needle aspiration(EUS-FNA)have gradually become established tools for the diagnosis,staging and treatment of benign or malignant gastrointestinal diseases and pulmonary disorders[1].Compared with standard upper endoscope,EUS uses a dedicated echoendoscope that has a more rigid tip and a longer nonflexible segment at the most distal end of the device.On the other hand,most currently available linear echoendoscopes are side-viewing instruments.Both the unique mechanical and optical features of EUS scopes make manipulations difficult;even skilled EUS operators occasionally encounter difficulty when inserting,which may be more likely to cause severe complications[2].One of the most frequent complications is gastrointestinal perforation,which can take place in the hypopharynx,hiatal hernia,tip of the duodenal bulb and rectosigmoidal junction[3].The incidence rate of pharyngoesophageal perforations resulting from gastrointestinal endoscopes is approximately 0.01%[2].For EUS,a higher risk of perforation has been reported[4].Hypopharyngeal perforation can lead to lethal complications(e.g.mediastinitis,mediastinal pneumothorax and fistulas)and these complications are associated with a mortality rate of 2%–36%[5].Therefore,it is necessary to explore some techniques to avoid these complications to the utmost extent.