TRAF4 Promotes Fibroblast Proliferation in Keloids by Destabilizing p53 via Interacting with the Deubiquitinase USP10.

Keloids represent one extreme of aberrant dermal wound healing. One of the important characteristics of keloids is uncontrolled fibroblasts proliferation. However, the mechanism of excessive proliferation of fibroblasts in keloids remains elusive. In this study, we demonstrated that TRAF4 was highly expressed in keloid fibroblasts and promoted fibroproliferation. We investigated the underlying molecular mechanism and found that TRAF4 suppressed the p53 pathway independent of its E3 ubiquitin ligase activity. Specifically, TRAF4 interacted with the deubiquitinase USP10 and blocked the access of p53 to USP10, resulting in p53 destabilization. Knockdown of p53 rescued cell proliferation in TRAF4-knockdown keloid fibroblasts, suggesting that the regulation of proliferation by TRAF4 in keloids relied on p53. Furthermore, in keloid patient samples, TRAF4 expression was inversely correlated with p53-p21 signaling activity. These findings help to elucidate the mechanisms underlying keloid development and indicate that blocking TRAF4 could represent a potential strategy for keloid therapy in the future.

Application of an oligonucleotide array assay for rapid detecting and genotyping of Chlamydia trachomatis from urogenital specimens.

An oligonucleotide array technology was established for rapidly detecting and genotyping Chlamydia trachomatis in urogenital infections. The VS1-VS2 region of the omp1 gene was used to design oligonucleotide probes. Eleven serovar-specific probes to serovars A, B, C, D, E, F, G, H, I, J, and K, and 3 group-specific probes to group B (B, Ba, D, E, L1, and L2), group C (A, C, H, I, J, K, and L3), and an intermediate group (F and G) were synthesized and spotted onto the nylon membrane. Two pairs of universal primers were designed for the nested polymerase chain reaction (PCR) amplification of the VS1-VS2 gene. Digoxigenin-labeled amplicons of the VS1-VS2 gene of C. trachomatis were hybridized to the membrane array. Hybridization signals were read by the nitroblue tetrazolium/5-bromo-4-chloro-3-indolylphosphate color development. The assay developed was tested with reference strains of C. trachomatis serovars and clinical samples. The sensitivity was evaluated for 57 samples previously found to be positive for C. trachomatis by using plasmid PCR, and 98.2% (56/57) concordance was obtained. Fourteen oligonucleotide probes were optimized by trying different reaction conditions, showing specific hybridization with the corresponding reference strains, but no cross-reactions with other urogenital microorganisms. Using this procedure, a total of 59 strains were detected from 56 chlamydial samples. Eight genotypes were found, and type D, E, F, and H were the most frequently observed types (77.9%). Three cases (5.4%) had multiple infections with serovars: 1.D/E, 2.D/F, and 3.F/K. To validate the reference strains and confirm the genotype identity as determined by the oligonucleotide array technology, we sequenced all reference strains and 10 selected specimens across variable sequence VS1 and VS2. No discrepancies were found between the array typing and the genotype identity confirmed by nucleotide sequencing of the PCR product. The findings from this study indicated that the oligonucleotide array is a simple, fast, and specific assay for directly detecting and genotyping C. trachomatis from clinical samples.

[A comparison of human papillomavirus detection and ThinPrep cytology test for women in Guangdong province].

OBJECTIVE: To evaluate the etiological significance of human papillomavirus (HPV) in cervical cancer and the clinical utility of HPV detection in cervical cancer screening. METHODS: Hybrid capture II test was used to detect 13 high-risk HPV genotypes from cervical scrapes of 2636 women. Cervical cytology was also evaluated in 454 of them by ThinPrep Pap smear. RESULTS: Among 2636 women, 699 (26.5%) were found to be high-risk HPV positive. The highest infection rate (59.4%) was found in the age group of < or = 20 years and the lowest infection rate in the age group of 41 approximately 50 years (21.0%). Significant differences in HPV infection rate were found between different cities in Guangdong province, such as those between Xinhui and Guangzhou, Xinhui and Shenzhen, Xinhui and Dongguan (P < 0.01). Fifteen out of 16 women (93.8%) with cervical carcinoma were infected with high-risk HPV versus 24 out of 125 women (19.2%) attending routine cervical cancer screening (P < 0.001). The HPV infection rate was 30.8% (142 out of 461) in women with cervical erosion, which was significantly lower than that in patients with cervical carcinoma (P < 0.001). HPV DNA were detected in 100% (2/2) of squamous cell carcinoma (SCC), 100% (12/12) high grade squamous intraepithelial lesion (HSIL), 88.9% (16/18) of low grade squamous intraepithelial lesion (LSIL) and 37.8% (28/74) of atypical squamous cells (ASC). CONCLUSION: High-risk HPV genotypes are the major causes of cervical cancers and HPV detection is a reliable adjuvant tool for cervical cancer screening.

Secreted expression of dengue virus type 2 full-length envelope glycoprotein in Pichia pastoris.

The full-length envelope glycoprotein gene of dengue virus type 2 was cloned using an RT-PCR method from the infected C6/36 cells and inserted into pPICZaB vector. The recombinant plasmid was integrated into Pichia pastoris by electroporation and the expressed product was identified by SDS-PAGE and Western blotting. High-level secreted expression was performed by determining the Mut(+) phenotype and screening multi-copy integrants in the recombinant yeast cells. A recombinant protein with a molecular size of approximately 69 kDa was secreted into the supernatant from the yeast cells when induced with methanol. The expressed supernatant was able to bind with mouse polyclonal antibody or E-specific monoclonal antibody of dengue-2 virus. Purified E-poly (His)-tagged fusion protein was obtained from the expressed product by passing through a metal-chelating affinity chromatographic (MCAC) column. The results of Western blotting and solid-phase ELISA using dengue virus antibodies indicated that the purified recombinant E glycoprotein retained its antigenicity. High-level production of the recombinant E protein up to 100 mg/l indicates that P. pastoris is an efficient expression system for dengue virus full-length envelope glycoprotein.

The prevalence and distribution of Chlamydia trachomatis genotypes among sexually transmitted disease clinic patients in Guangzhou, China, 2005-2008.

This study was designed to determine the prevalence and distribution of Chlamydia trachomatis genotypes from clinical specimens in Guangzhou, China, obtained in the period 2005-2008. One hundred and ninety-four urogenital C. trachomatis samples were collected from sexually transmitted disease clinic patients, and the VS1-VS2 of OmpA gene was amplified by nested PCR and sequenced using an ABI-prism 3730 sequencer. Clinical C. trachomatis strains were genotyped and analyzed for a mutation with respect to the reference VS1-VS2 sequence. VS1-VS2 fragments with 453 bp were amplified from 194 clinical samples. Upon alignment with the sequences of the reference strains, 189 strains with discernible sequences were typed into 9 genotypes, while 5 with ambiguous sequences were considered to be mixed-serovar samples. The most prevalent genotypes were E (50, 26%), F (46, 24%), J (35, 19%), and D (24, 13%). There was no significant difference in the distribution of any of the genotypes detected during the study period, except for genotype K (P<0.01). A total of 16 (8%, 16/189) genetic variants of the OmpA VS1-VS2 of the reference strains were identified. Mutations occurred frequently for genotypes D (2/24, 8%), E (6/50, 12%), F (2/46, 4%), G (1/8, 13%), H (1/12, 8%), and K (4/11, 36%), with most of these being sense mutations that may result in amino acid substitution. Sequencing the OmpA VS1-VS2 enabled the genotype and sequence variations within each genotype to be analyzed. Genotypes E, F, J, and D continued to dominate among urogenital C. trachomatis, whereas genotype K increased significantly in Guangzhou between 2005 and 2008.

[Inoculation of plasmid expressing the dengue 2 NS1 gene elicits immunity in mice].

OBJECTIVE: To study cellular and humoral immune responses to NS1 protein in mice inoculated intramuscularly with recombinant plasmid expressing dengue 2 NS1 gene. METHODS: The eukaryotic expressing plasmid pCNX2-NS1 was injected into tibialis anterior muscle in mice. The mice were subsequently boosted with the same dose and same method twice after the initial inoculation. The mice were killed at four-week intervals and their serum and spleen cells were harvested for further test. RESULTS: Dengue 2 antibodies were detectable in the sera from inoculated animals four weeks after the last boost. The changes of CD4+ T lymphocyte and CD8+ T lymphocyte were also determined by flow cytometry. CONCLUSION: The recombinant plasmid containing dengue 2 NS1 genes is immunogenic in intramuscularly inoculated mice. The vaccinated mice produced dengue-2 specific and long lasting immunity.