1.Citalopram attenuates tau hyperphosphorylation of cortex and memory deficits in social isolation-reared rats
Chinese Journal of Behavioral Medicine and Brain Science 2016;25(3):193-197
Objective To explore the effect of citalopram on tau phosphorylation and memory defi-cits induced by social isolation (SI) in adult rats.Methods Sixty Sprague-Dawley adult rats (8 months) were grouped or isolation reared for six-weeks.Following the initial two-week period of rearing, citalopram ( 10 mg/kg,i.p.) was administered for 4 weeks.Novel object recognition test,Western blot and ELISA were used to detect recognitive function,the levels of tau and GSK-3βprotein,and melatonin level respectively. Results In the novel object recognition test,compared with the citalopram group(0.71±0.05) and housed group(0.73±0.13),discrimination ratio(0.48±0.15) in SI group was significant decreased (P<0.05).Tau hyperphosphorylation at Tau-1 ((0.88±0.11)),Ser396 (3.94±0.74) episodes were found and almost re-versed by citalopram at Tau-1 (1.56±0.17),Ser396 (2.31±0.24) episodes in SI group.Compared with GH group,the total level of GSK-3β(1.12±0.09) was significantly increased,while the level of Ser9-phosphoryl-ated GSK-3β(inactive form) (0.47±0.11) was significantly decreased in the SI group,both of which were reversed by citalopram (GSK-3β(0.87±0.08) and Ser9-phosphorylated GSK-3β(0.80±0.07)).The me-latonin level was decreased in SI group ((359.54±18.80)pg/ml),and citalopram could partly restore the level of melatonin (418.15±18.72)pg/ml, P<0.05).Conclusion The results demonstrate that citalopram increases the level of melatonin which negatively regulates GSK-3βand attenuates tau hyperphosphorylation and memory deficits induced by SI in adult rats.
2.Analysis of risk factors of recurrent uveitis and establishment of prediction model
Jin, GONG ; Ping, WANG ; Guanghai, QIN ; Qingguo, YANG ; Ting, ZHAO ; Linling, WANG
Chinese Journal of Experimental Ophthalmology 2014;32(7):627-630
Background Replase of uveitis is a primary cause of vision damage.To predict recurrentassociated factors for uveitis is very critical for the prevention and management of uveitis.Objective This study was to explore the risk factors of recurrent uveitis and establish the prediction model of recurrent uveitis.Methods Clinical data of recurrent uveitis patients who were diagnosed in Renhe Hospital of Three Gorges University from July 1,2010 to June 30,2011 were retrospectively reviewed.The demography characteristics of the patients were collected and the disease was followed-up under the informed consent.Kaplan-Meier method was used to estimate the disease recurrence rate and to plot relapse-free survival curve at different levels of predictive factors.Multivariate Cox proportional hazards model was used to select independent risk factors of relapse and establish the prediction model for recurrent uveitis.Results Total 825 cases of recurrent uveitis were included and followed up for 1 month to 38 months,with a median following-up time of 16 months.Relapse of uveitis was identified in 149 cases (18.1%)during the following-up duration.The relapse-free survival time was from 1 month to 38 months,and the 1-,2-and 3-year cumulative recurrence-free survival rates were 87.3%,82.8% and 80.9%.Multivariate Cox proportional hazards regression analysis showed that immunosuppression withdrawal(X1) (β =0.940,Waldx2 =12.018,P =0.001),oral steroid withdrawal (X2) (β =1.334,Wald x2 =18.450,P < 0.001),colds (X3) (β =0.642,Wald x2 =11.988,P =0.001),work and study stress(X4) (β=0.285,Wald x2 =4.925,P=0.026) and excessive alcohol and tobacco(X5) (3--0.541,Wald x2 =4.718,P =0.030) were the independent risk factors for recurrence of uveitis.The risk of recurrence in patients with uveitis function model expression was h (t)=h0 exp (2.559 X1 +3.797 X2 + 1.901 X3 + 1.331 X4 +1.719 X5).Conclusions Replase of uveitis is an interaction of many factors,and immunosuppression withdrawal,oral steroid withdrawal,colds,work and study stress,excessive alcohol and tobacco are independent risk factors for recurrence of uveitis.An intervention according to the controllable factors is one of the important ways to prevent the recurrence of uveitis.
3.Determining structural ensembles of flexible multi-domain proteins using small-angle X-ray scattering and molecular dynamics simulations.
Yonghui ZHANG ; Bin WEN ; Junhui PENG ; Xiaobing ZUO ; Qingguo GONG ; Zhiyong ZHANG
Protein & Cell 2015;6(8):619-623
Algorithms
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Carrier Proteins
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chemistry
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Crystallography, X-Ray
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Humans
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Magnetic Resonance Spectroscopy
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Molecular Dynamics Simulation
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Nuclear Proteins
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chemistry
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Principal Component Analysis
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Protein Structure, Tertiary
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Proteins
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chemistry
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Scattering, Small Angle
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X-Ray Diffraction
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methods
4.The study on growth and proliferation of neural stem cells from rats in vitro.
Qingguo CHEN ; Yong FU ; Xianhong WANG ; Xiaohui WU ; Rui ZHU ; Zewen LI ; Shusheng GONG
Journal of Clinical Otorhinolaryngology Head and Neck Surgery 2008;22(16):747-750
OBJECTIVE:
To investigate culturing neural stem cells (NSCs) from rat embryos in vitro and to observe their growth and differentiation.
METHOD:
NSCs were isolated from hippocampus of SD rat embryos (P16-P18) and cultured in DMEM/F12 medium containing EGF, bFGF, B27. To observe process of cell proliferation by microscope and identify cell types by immunocytochemical analyses after differentiation.
RESULT:
NSCs grew well in serum-free conditional medium and their cell bodies present transparent with good refraction at about eighth day. After differentiation, the cells demonstrated NSE and GFAP immunoreactive.
CONCLUSION
NSCs were cultured well in serum-free conditional medium and they could be induced to differentiate into neurons and astrocytes in serum conditional medium.
Animals
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Cell Differentiation
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Cell Proliferation
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Cells, Cultured
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Culture Media, Serum-Free
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Embryo, Mammalian
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Female
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Hippocampus
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cytology
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embryology
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Multipotent Stem Cells
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cytology
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Neural Stem Cells
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cytology
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Pregnancy
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Rats
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Rats, Sprague-Dawley
5.Effect of the intense noise on hearing function and cochlea morphology in rat.
Yong FU ; Shusheng GONG ; Qiuhong XUE ; Guopeng WANG ; Qingguo CHEN
Journal of Clinical Otorhinolaryngology Head and Neck Surgery 2008;22(11):509-512
OBJECTIVE:
To observe the changes of auditory electrophysiology and inner ear pathology in rat cochlea after the noise exposure, and to offer the experimental data for exploring the mechanism of noise-damaged cochlea.
METHOD:
The rats in the study group were exposed to a intense narrow band noise centered at 4 kHz at the leave of 120 dB (SPL) for 4 h. The exposed cochleae were collected at various intervals (1 or 21 days) after the noise exposure. Auditory function was monitored by measuring thresholds of auditory brain stem responses (ABR). The morphological changes in rat cochlear hair cell (HC) were examined by HC nuclei stained with Propidium iodide (PI), a fluorescent dye specifically labelling the nuclear DNA and scanning electron microscopy (SEM). The number of spiral ganglion cells was calculated using pathologic technique.
RESULT:
The thresholds of ABR in the study group were significantly greater than that in the normal control group (P < 0.01). Examined at 1 day after the noise exposure, normal, apoptosis, necrotic and missing out hair cell (OHC) could be distinguished with PI staining, whereas the apoptosis OHC were not found at 21 days. Significant OHC loss was found in as compared to the normal control group (P < 0.01). There was not significant difference in the calculation of spiral ganglion cells (P > 0.05). SEM revealed the injured stereocilia of OHC (disarrangement, collapse) and OHC loss in the study group, which was more severe in OHC3 than the other two rows of OHC.
CONCLUSION
The intense noise used in our study could injure the rat cochlea and bring permanent threshold shift (PTS). Under this condition, the death modes of HC in the cochlea include apoptosis and necrosis in the fore part, whereas necrotic is the major mode in the evening of exposure. The injured stereocilia of OHC and OHC loss could remain the most consistent correlate of PTS.
Animals
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Apoptosis
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Auditory Threshold
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Cochlea
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pathology
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physiopathology
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Evoked Potentials, Auditory, Brain Stem
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Hearing
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Hearing Loss, Noise-Induced
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pathology
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physiopathology
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Necrosis
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Noise
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adverse effects
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Rats
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Rats, Sprague-Dawley
6.Structural insights into the recognition of phosphorylated FUNDC1 by LC3B in mitophagy.
Mengqi LV ; Chongyuan WANG ; Fudong LI ; Junhui PENG ; Bin WEN ; Qingguo GONG ; Yunyu SHI ; Yajun TANG
Protein & Cell 2017;8(1):25-38
Mitophagy is an essential intracellular process that eliminates dysfunctional mitochondria and maintains cellular homeostasis. Mitophagy is regulated by the post-translational modification of mitophagy receptors. Fun14 domain-containing protein 1 (FUNDC1) was reported to be a new receptor for hypoxia-induced mitophagy in mammalian cells and interact with microtubule-associated protein light chain 3 beta (LC3B) through its LC3 interaction region (LIR). Moreover, the phosphorylation modification of FUNDC1 affects its binding affinity for LC3B and regulates selective mitophagy. However, the structural basis of this regulation mechanism remains unclear. Here, we present the crystal structure of LC3B in complex with a FUNDC1 LIR peptide phosphorylated at Ser17 (pS), demonstrating the key residues of LC3B for the specific recognition of the phosphorylated or dephosphorylated FUNDC1. Intriguingly, the side chain of LC3B Lys49 shifts remarkably and forms a hydrogen bond and electrostatic interaction with the phosphate group of FUNDC1 pS. Alternatively, phosphorylated Tyr18 (pY) and Ser13 (pS) in FUNDC1 significantly obstruct their interaction with the hydrophobic pocket and Arg10 of LC3B, respectively. Structural observations are further validated by mutation and isothermal titration calorimetry (ITC) assays. Therefore, our structural and biochemical results reveal a working model for the specific recognition of FUNDC1 by LC3B and imply that the reversible phosphorylation modification of mitophagy receptors may be a switch for selective mitophagy.
Crystallography, X-Ray
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Membrane Proteins
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chemistry
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metabolism
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Microtubule-Associated Proteins
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chemistry
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metabolism
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Mitochondrial Degradation
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Mitochondrial Proteins
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chemistry
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metabolism
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Peptides
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chemistry
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metabolism
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Phosphorylation
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Protein Structure, Quaternary