RNA binding protein 24 regulates the translation and replication of hepatitis C virus

The secondary structures of hepatitis C virus (HCV) RNA and the cellular proteins that bind to them are important for modulating both translation and RNA replication. However, the sets of RNA-binding proteins involved in the regulation of HCV translation, replication and encapsidation remain unknown. Here, we identified RNA binding motif protein 24 (RBM24) as a host factor participated in HCV translation and replication. Knockdown of RBM24 reduced HCV propagation in Huh7.5.1 cells. An enhanced translation and delayed RNA synthesis during the early phase of infection was observed in RBM24 silencing cells. However, both overexpression of RBM24 and recombinant human RBM24 protein suppressed HCV IRES-mediated translation. Further analysis revealed that the assembly of the 80S ribosome on the HCV IRES was interrupted by RBM24 protein through binding to the 5'-UTR. RBM24 could also interact with HCV Core and enhance the interaction of Core and 5'-UTR, which suppresses the expression of HCV. Moreover, RBM24 enhanced the interaction between the 5'- and 3'-UTRs in the HCV genome, which probably explained its requirement in HCV genome replication. Therefore, RBM24 is a novel host factor involved in HCV replication and may function at the switch from translation to replication.

Comparison of two measures assessing prospective memory impairment in elderly people with schizophrenia / 中国心理卫生杂志

Objective:To compare the results of two different measures assessing prospective memory (PM) in elderly schizophrenia,and explore their diagnostic validity.Methods:Fifty patients who were diagnosed as schiz-ophrenia according to the criteria of Diagnostic and Statistical Manual of Mental Disorders,Fourth Edition (DSM-Ⅳ)and 50 normal elderly people were enrolled in the study.Laboratory paradigm prospective memory task and the Chinese version of the Cambridge prospective memory Test (C-CAMPROMPT)were administered to measure thelevel of EBPM and TBPM.The Wechsler Adult Intelligence Scale-Fourth Edition,Continuous Performance Test-I-dentical Pairs were used to evaluate IQ and attention.Results:Whether in the laboratory paradigm or C-CAM-PROMPT,schizophrenia group performed worse than normal controls on PM total scores[7(0,16)vs.12(0,16),14 (4,34)vs.25(11,36)],EBPM[3(0,8)vs.6(0,8),7(2,16)vs.14(4,18)]and TBPM [3(0,8)vs.6(0,8),6(2,18) vs.12(4,18)],and patients had comparable performances in PM subtypes[-1.0(-2.2,1.0)vs. -1.0(-2.1, 0.8),-1.9(-3.4,0.8)vs. -1.8(-2.9,1.6)].In the C-CAMPROMPT,the scores of EBPM and TBPM were negatively related to age(r=-0.36 --0.40,P<0.001 ),but there was no significant relationship between PM performance and age in the laboratory paradigm task.The area under ROC curve of the laboratory paradigm and C-CAMPROMPT were 0.73 and 0.85.While 8 and 19 as the cut off value,the sensitivity were 0.60 and 0.74,and the specificity were 0.76 and 0.90,respectively.Conclusion:The two measures have confirmed that the elderly schizophrenia have comparable performances in EBPM and TBPM.Both the C-CAMPROMPT and the laboratory paradigm have moderate level of diagnostic validity,but the former is slightly higher and more susceptible to aging.

The study on prospective and retrospective memory deficits in chronic schizophrenia / 中国神经精神疾病杂志

Objectives To compare prospective memory (PM) deficits with retrospective memory (RM) deficits and to explore the correlation between PM and RM in chronic schizophrenia. Methods Fifty chronic schizophrenia pa?tients and fifty healthy controls were recruited. The PM performance [event-based PM (EBPM) and time-based PM (TB?PM)] were evaluated by the Chinese version of the Cambridge Prospective Memory Test (C-CAMPROMPT); working memory (WM) was evaluated by the digital span subtest (DS);immediate auditory logical memory (IALM), delayed audito?ry logical memory (DALM), immediate visual reproduction memory (IVRM) and delayed visual reproduction memory (DVRM) were evaluated by the logical memory and visual reproduction subtest. The score of each test was transformed to comparable standard score. Results Patients performed significantly worse on EBPM [(7.9 ± 3.4) vs. (13.7 ± 2.9)], TBPM [(6.9±3.6) vs. (13.0±3.2)], DS [sequence:(5.8±2.0) vs. (7.5±2.2);backward:(6.5±1.9) vs. (8.2±2.8)], IALM [(8.3±3.1) vs. (11.9 ± 2.5)], DALM [(7.4 ± 3.7) vs. (11.8 ± 2.6)], IVRM [(8.0 ± 2.7) vs. (11.2 ± 3.8)], and DVRM [(7.7 ± 3.5) vs. (10.8 ± 2.7)] scores than controls (P0.05). The performance of PM in chronic schizophrenia was significantly related to DS (sequence and backward), IALM, DALM and DVRM (P<0.05), but not IVRM (P=0.155). Conclusion:There are greater prospective memory deficits than retrospective memory deficits in chron?ic schizophrenia and the prospective memory deficits are correlated with the retrospective memory deficits in chronic schizophrenia.

Reliability and Validity of Computerized Chinese Version of Cambridge Prospective Memory Test in Chronic Schizophrenia / 中国康复理论与实践

Objective To explore the reliability and validity of the computerized Chinese version of Cambridge Prospective Memory Test (C-CAMPROMPT) for assessment of prospective memory (PM) in chronic schizophrenia patients. Methods 50 patients and 50 healthy controls formed the study sample. PM performance was measured with computerized C-CAMPROMPT, while the Wechsler Adult Memory Scale-Forth Edition (WMS-IV), Wisconsin Card Sorting Test (WCST) and Category Fluency Test (CFT) were administered to assess logical memory (LM), visual representation (VR), executive function and processing speed. Results The test-retest reliability (0.981, P<0.001), split half reliability (0.627, P<0.001) and internal consistency reliability (0.742) of C-CAMPROMPT were satisfied. The scores of C-CAM-PROMPT and its subtest in schizophrenia were lower than that in healthy control (P<0.001). The performance of PM in patients with schizo-phrenia closely related to the scores of LM, VR, WCST-CC and CFT (r=0.34~0.89, P<0.05). The sensitivity (86%) and specificity (92%) of the scale were satisfied. Factor analysis extracted 2 factors. Conclusion The computerized C-CAMPROMPT shows a good reliability and validity for assessment of PM function in chronic schizophrenia, and is a sensitive, adaptable, stable instrument.