Fear renewal activates cyclic adenosine monophosphate signaling in the dentate gyrus.

BACKGROUND: Fear renewal, the context-specific relapse of a conditioned fear after extinction, is a widely pursued model of post-traumatic stress disorder and phobias. However, its cellular and molecular mechanisms remain poorly understood. The dentate gyrus (DG) has emerged as a critical locus of plasticity with relevance to memory, anxiety disorders, and depression, and it contributes to fear memory retrieval. Here, we have identified the role of the DG in fear renewal and its molecular mechanism. MATERIALS AND METHODS: Muscimol (MUS), activator of cyclic adenosine monophosphate (cAMP) forskolin (FSK), inhibitor of protein kinase A (PKA), Rip-cAMP, and a phosphodiesterase inhibitor rolipram were infused into DG of standard deviation rats before renewal testing. cAMP levels after fear renewal was measured by enzyme-linked immunosorbent assay. The protein levels of phosphodiesterase 4 (PDE4) isoforms were tested by western blot. At last, the roles of cAMP signaling were also tested in the acquisition of fear conditioning, fear retrieval, and extinction. RESULTS: Intra-DG treatment of MUS and Rp-cAMP impaired fear renewal. FSK and rolipram exhibited the opposite effect, which also occurred in the retrieval of original fear memory. This change in fear renewal was regulated by PDE4 isoforms PDE4A, PDE4A5, and PDE4D. In addition, FSK and rolipram facilitated the acquisition of fear conditioning in long-term memory, but not short-term memory, while Rp-cAMP impaired long-term memory. For extinction, FSK and rolipram inhibited extinction process, while Rp-cAMP facilitated fear extinction. CONCLUSION: These findings demonstrated that fear renewal activated cAMP signaling in the DG through decreased PDE4 activity. Because of the role of cAMP signaling in the acquisition or retrieval of fear conditioning and encoding of extinction, it is speculated that initial learning and extinction may have similarities in molecular mechanism, especially fear retrieval and fear renewal may share cAMP signaling pathway in the DG.

Genetic polymorphisms and mutation rates of 27 Y-chromosomal STRs in a Han population from Guangdong Province, Southern China.

In this study, we collected blood samples from 1033 father-son pairs of a Han population from Guangdong Province, Southern China, of which 1007 fathers were unrelated male individuals. All together, 2040 male individuals were analyzed at 27 Y-chromosomal short tandem repeats (Y-STRs) with Yfiler(®) Plus system. A total of 1003 different haplotypes were observed among 1007 unrelated fathers, with the overall haplotype diversity (HD) 0.999992 and discrimination capacity (DC) 0.996. The gene diversity (GD) values for the 27 Y-STR loci ranged from 0.4400 at DYS438 to 0.9597 at DYS385a/b. 11 off-ladder alleles and 25 copy number variants were detected in 1007 males. Population relationships were analyzed by comparison with 19 other worldwide populations. With 27,920 allele transfers in 1033 father-son pairs, 124 mutation events occurred, of which 118 were one-step mutations and 6 were two-step mutations. Eleven father-son pairs were found to have mutations at two loci, while one pair at three loci. The estimated locus-specific mutation rates varied from 0 to 1.74×10(-2), with an average estimated mutation rate 4.4×10(-3) (95%CI: 3.7×10(-3) to 5.3×10(-3)). Mutations were most frequently observed at three rapidly mutating Y-STRs (RM Y-STRs), DYS576, DYS518 and DYS627. However, at DYS570, DYS449 and DYF387S1 loci, which were also described as RM Y-STRs, the mutation rates in Guangdong Han population were not as high as estimated in other populations.

Analysis of 24 Y-STR haplotype data in a Chinese Han population from Guangdong Province.

In this study, we investigated the genetic polymorphisms of 24 Y-chromosomal short tandem repeat (Y-STR) loci in 885 unrelated Chinese Han male individuals from Guangdong Province, using a domestic AGCU Y24 STR kit. A total of 878 different haplotypes were observed at the 24 Y-STR loci; among them, 871 haplotypes were unique and 7 haplotypes occurred twice. The overall haplotype diversity was 0.99998 and the discrimination capacity was 99.2%. The gene diversity values ranged from 0.4354 at DYS438 to 0.9606 at DYS385a/b. Population relationships between the Guangdong Han population and seven other published Chinese populations were evaluated by Rst values and visualized in a two multi-dimensional scaling plot. The results showed the 24 Y-STR loci are highly polymorphic in Guangdong Han population and of great value in forensic application.

[Mutations in a Large Pedigree with Y-STR Genetic Markers].

OBJECTIVE: To explore the mutation of Y-STR loci in meiotic allelic transmission in a large pedigree. METHODS: The oral swabs of 163 male individuals were collected from a Lin pedigree. Twenty-two Y-STR genetic markers were typed with AGCU Y24 fluorescent detection kit (AGCU Y24 system), which also contained 16 Y-STR markers included in Yfiler multiple amplification kit (Yfiler system). The genotyping results of Y-STR loci were compared between each two males in the pedigree. RESULTS: There were 20 and 30 kinds of haplotypes obtained with Yfiler and AGCU Y24 systems in 163 male individuals from the Lin pedigree, respectively. The rates referred to haplotype differences (RRHD) of these two typing systems between male pairs were 0.910 5 and 0.922 7, respectively. The average number of marker differences were 6.582 1 and 9.824 8, respectively. The RRHD increased along with the incidents of meiosis. CONCLUSION: Y-STR mutation leads to different Y-STR haplotypes among the male members in a paternal pedigree and the rate of difference increases along with the incidents of meiosis.

Analysis of 17 Y-STR loci haplotype and Y-chromosome haplogroup distribution in five Chinese ethnic groups.

To investigate genetic diversity in Chinese populations, 706 unrelated male individuals from five ethnic groups (Han, Korean, Hui, Mongolian, and Tibetan, respectively) were analyzed with 17 Y-chromosomal STRs. The haplotype diversity was 0.99985 in the combined data. A total of 675 distinct haplotypes were observed, of which 649 were unique. Y-chromosome haplogroups in the five groups were also predicted with Y-STR haplotypes. Genetic distance between the five studied ethnic groups and other published groups was analyzed by analysis of molecular variance and visualized in a multidimensional scaling plot. In conclusion, the 17 Y-STR loci are highly polymorphic markers in the five groups and hence are very useful in forensic application, population genetics, and human evolution studies.

[Age estimation using content of sjTREC in human peripheral blood].

OBJECTIVE: To determine and verify the correlation formula of age estimation using the content of signal joint T-cell receptor excision DNA circle (sjTREC) in human peripheral blood and to discuss its application value in forensic biological practice. METHODS: The samples of peripheral blood stains were collected from 30 healthy unrelated individuals whose ages were known. The DNAs were extracted from the samples stored at room temperature after 4 weeks. The content of sjTREC was measured by real-time fluorescent quantitative PCR technique, and the TATA box binding protein (TBP) was selected as reference genes. The age of each sample was predicted with the formula which was Age = -7.181 5 Y-42.458 +/- 9.42 (Y = dCtTBP-sjTREC), and the result was compared with the real age of each individual to determine the accuracy of the formula. RESULTS: sjTREC and TBP gene were detectable in all 30 samples of peripheral blood. The contents of sjTREC in human peripheral blood showed a decreasing tendency with aging. The accuracy rate for the age estimation by this method was 76.67%. CONCLUSION: The method for the age estimation with the content of sjTREC was simple, fast, sensitive, and good species specific with important potential application prospect.

A novel micro-linear vector for in vitro and in vivo gene delivery and its application for EBV positive tumors.

BACKGROUND: The gene delivery vector for DNA-based therapy should ensure its transfection efficiency and safety for clinical application. The Micro-Linear vector (MiLV) was developed to improve the limitations of traditional vectors such as viral vectors and plasmids. METHODS: The MiLV which contained only the gene expression cassette was amplified by polymerase chain reaction (PCR). Its cytotoxicity, transfection efficiency in vitro and in vivo, duration of expression, pro-inflammatory responses and potential application for Epstein-Barr virus (EBV) positive tumors were evaluated. RESULTS: Transfection efficiency for exogenous genes transferred by MiLV was at least comparable with or even greater than their corresponding plasmids in eukaryotic cell lines. MiLV elevated the expression and prolonged the duration of genes in vitro and in vivo when compared with that of the plasmid. The in vivo pro-inflammatory response of MiLV group was lower than that of the plasmid group. The MEKK1 gene transferred by MiLV significantly elevated the sensitivity of B95-8 cells and transplanted tumor to the treatment of Ganciclovir (GCV) and sodium butyrate (NaB). CONCLUSIONS: The present study provides a safer, more efficient and stable MiLV gene delivery vector than plasmid. These advantages encourage further development and the preferential use of this novel vector type for clinical gene therapy studies.

Predicting human age with bloodstains by sjTREC quantification.

The age-related decline of signal joint T-cell receptor rearrangement excision circles (sjTRECs) in human peripheral blood has been demonstrated in our previous study and other reports. Until now, only a few studies on sjTREC detection in bloodstain samples were reported, which were based on a small sample of subjects of a limited age range, although bloodstains are much more frequently encountered in forensic practice. In this present study, we adopted the sensitive Taqman real-time quantitative polymerase chain reaction (qPCR) method to perform sjTREC quantification in bloodstains from individuals ranging from 0-86 years old (n = 264). The results revealed that sjTREC contents in human bloodstains were declined in an age-dependent manner (r = -0.8712). The formula of age estimation was Age = -7.1815Y-42.458 ± 9.42 (Y dCt(TBP-sjTREC); 9.42 standard error). Furthermore, we tested for the influence of short- or long- storage time by analyzing fresh and stored bloodstains from the same individuals. Remarkably, no statistically significant difference in sjTREC contents was found between the fresh and old DNA samples over a 4-week of storage time. However, significant loss (0.16-1.93 dCt) in sjTREC contents was detected after 1.5 years of storage in 31 samples. Moreover, preliminary sjTREC quantification from up to 20-year-old bloodstains showed that though the sjTREC contents were detectable in all samples and highly correlated with donor age, a time-dependent decrease in the correlation coefficient r was found, suggesting the predicting accuracy of this described assay would be deteriorated in aged samples. Our findings show that sjTREC quantification might be also suitable for age prediction in bloodstains, and future researches into the time-dependent or other potential impacts on sjTREC quantification might allow further improvement of the predicting accuracy.

[Calculation of the avuncular index].

OBJECTIVE: To introduce the method of avuncular index (AI) calculation. METHODS: Identity by decent coefficient, coancestry coefficient and AI law were employed in identification of uncle-niece relationship, when autosomal STR loci were detected to determine controversial uncle-niece relationship. RESULTS: The results of AI calculation were coincidental using identity by descent coefficien, coancestry coefficient and AI law. CONCLUSION: The results are coincidental using three methods in the different situations. AI index is higher with participation of children's mother.

[Cloning of Rcet3, a novel gene related to family 2 cystatins].

OBJECTIVE: To clone the full-length Rcet3 gene, a novel gene related to family 2 cystatins, from mouse testis or other tissues. METHODS: Rcet3 gene was cloned using digital differential display (DDD) and RT-PCR was performed for cloning the full-length Rcet3 gene from adult mouse testis cDNA library with sequence analysis. RESULTS: Rcet3 cDNA was 610 bp in length, consisting of 4 exons to encode a protein with 140 amino acid residues. The encoded protein contained a potential signal peptide and a cystatin domain, but lacked critical consensus site important for cysteine protease inhibition. These characteristics could be seen in the Cres subgroup related to the family 2 cystatins. Rcet3 was specifically expressed in adult mouse testis, epididymis and the cerebrum, but at higher levels in the testis than in the epididymis and cerebrum. CONCLUSION: Rcet3 may be a new member of Cres subgroup of family 2 cystatins.

[Proliferation cycle changes of Epstein-Barr virus in nasopharyngeal carcinoma cell line CNE after infection].

BACKGROUND & OBJECTIVE: The strategy of gene therapy on nasopharyngeal carcinoma (NPC) is determined by the characteristics of proliferation cycle of Epstein-Barr virus (EBV) in different histological types of NPC cells. This study was to investigate the characteristics of proliferation cycle of EBV in NPC cell line CNE2. METHODS: CNE2 cells were co-cultivated with marmoset lymphocyte line B95-8, which was EBV-positive. Then B95-8 cells were removed by cytotoxic test of complement activation. The initial infection state of EBV in CNE2 cells was analyzed by reverse transcription-polymerase chain reaction (RT-PCR) and Southern hybridization. RESULTS: CNE2 cells were infected with EBV by cell-to-cell contacting. The transcription of BZLF1, the symbol gene for EBV lytic phase, maintained 12 days on average. The transcription of EBV-encoded small RNA (EBER), the symbol gene for EBV infectious phase, maintained 22 days on average. CONCLUSIONS: After invading CNE2 cells, most EBV initially might be at lytic phase, then switch to the relatively stable latent phase, and finally be lost due to cell culture and passage.

[Preparation of anti-human indoleamine 2,3-dioxygenase polyclonal antibody].

BACKGROUND & OBJECTIVE: Indoleamine 2,3-dioxygenase (IDO), a cytosolic hemoprotein, catalyzes the rate-limiting step in tryptophan catabolism along the kynurenine pathway in mammals, arrests the growth of pathogens, and suppresses T-cell responses, therefore, leads to IDO-dependent tumor immune tolerance. This study was to express and purify His-hIDO fusion protein and to generate rabbit anti-human IDO polyclonal antibody, which was used to analyze IDO expression in tumor cells. METHODS: Human IDO cDNA was cloned into pET30a(+). The recombinant vector pET30a(+)-hIDO was transformed into BL21 after sequencing. The expression of His-hIDO protein was induced by IPTG. The anti-human IDO polyclonal antibody was obtained by immunizing rabbits with purified His-hIDO protein. The quality of the antibody was identified by Western blot. IDO expression in human fibroblast cancer cell line A431 and liver cancer cell line HepG2 induced by interferon-gamma (IFN-gamma) was also analyzed using the antibody. RESULTS: His-hIDO fusion protein was specifically combined with His-probe polyclonal antibody. The rabbit anti-human IDO polyclonal antibody was of high titer with high specificity. It could recognize IDO expression induced by IFN-gamma in A431 and HepG2 cells. CONCLUSION: The rabbit anti-human IDO polyclonal antibody could recognize IDO expression in tumor cells in vitro effectively, therefore, provides a tool to study the role of IDO in tumor immune tolerance.

Rapid detection of six common Chinese G6PD mutations by MALDI-TOF MS.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a common X-linked hereditary enzymopathy. We describe here the techniques based on matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) and multiprimer extension (multi-PEX) to detect the most common Chinese G6PD mutations, which are the single-point mutations G-->T at nt 1376, G-->A at nt 1388, A-->G at nt 95, G-->T at nt 392, C-->T at nt 1024, and C-->T at nt 1311. Fifteen samples were genotyped using this method coupled with direct sequencing, after identification of G6PD mutations by ARMS. In this study, we identified a mutation G-->T at nt 1376, which had been G-->A at nt 1388 using ARMS, while the result of sequencing corresponds with ours. This indicates the reliability of this method. Furthermore, since it can scan six common Chinese G6PD mutations simultaneously in one mass spectrum, this approach could be used to fast diagnose these G6PD mutations accurately in large-scale analysis.