Fusion Expression and Immunogenicity of EHEC EspA-Stx2A1 Protein: Implications for the Vaccine Development

Yan Cheng,Youjun Feng,Ping Luo,Jiang Gu,Shu Yu,Wei-jun Zhang,Yan-qing Liu,Qing-xu Wang,Quan-ming Zou,Xu-hu Mao 한국미생물학회 2009 The journal of microbiology Vol.47 No.4

Shiga toxin 2 (Stx2) is a major virulence factor for enterohemorrhagic Escherichia coli (EHEC), which is encoded by λ lysogenic phage integrated into EHEC chromosome. Stx2A1, A1 subunit of Stx2 toxin has gathered extensive concerns due to its potential of being developed into a vaccine candidate. However, the substantial progress is hampered in part for the lack of a suitable in vitro expression system. Here we report use of the prokaryotic system pET-28a::espA-Stx2A1/BL21 to carry out the fusion expression of Stx2A1 which is linked to E. coli secreted protein A (EspA) at its N-terminus. Under the IPTG induction, EspA- Stx2A1 fusion protein in the form of inclusion body was obtained successfully, whose expression level can reach about 40% of total bacterial protein at 25°C, much higher than that at 37°C. Western blot test suggested the refolded fusion protein is of excellent immuno-reactivity with both monoclonal antibodies, which are specific to EspA and Stx2A1, respectively. Anti-sera from Balb/c mice immunized with the EspA-Stx2A1 fusion protein were found to exhibit strong neutralization activity and protection capability in vitro and in vivo. These data have provided a novel feasible method to produce Stx2A1 in large scale in vitro, which is implicated for the development of multivalent subunit vaccines candidate against EHEC O157:H7 infections.

Distinctive Roles of Wnt Signaling in Chondrogenic Differentiation of BMSCs under Coupling of Pressure and Platelet-Rich Fibrin

Cheng Baixiang,Feng Fan,Shi Fan,Huang Jinmei,Zhang Songbai,Quan Yue,Tu Teng,Liu Yanli,Wang Junjun,Zhao Ying,Zhang Min 한국조직공학과 재생의학회 2022 조직공학과 재생의학 Vol.19 No.4

BACKGROUND: Although newly formed constructs of feasible pressure-preadjusted bone marrow mesenchymal stem cells (BMSCs) and platelet-rich fibrin (PRF) showed biomechanical flexibility and superior capacity for cartilage regeneration, it is still not very clear how BMSCs and seed cells feel mechanical stimuli and convert them into biological signals, and the difference in signal transduction underlying mechanical and chemical cues is also unclear. METHODS: To determine whether mechanical stimulation (hydrostatic pressure) and chemical cues (platelet-rich fibrin, PRF) activate canonical or noncanonical Wnt signaling in BMSCs, BMSCs cocultured with PRF were subjected to hydrostatic pressure loading, and the activation of the Wnt signaling molecules and expression of cartilage-associated proteins and genes were determined by western blotting and polymerase chain reaction (PCR). Inhibitors of canonical or noncanonical Wnt signaling, XVX-939 or L690,330, were adopted to investigate the role of Wnt signaling molecules in mechanically promoted chondrogenic differentiation of BMSCs. RESULTS: Hydrostatic pressure of 120 kPa activated both Wnt/b-catenin signaling and Wnt/Ca2? signaling, with the the maximum promotion effect at 60 min. PRF exerted no synergistic effect on Wnt/b-catenin signaling activation. However, the growth factors released by PRF might reverse the promotion effects of pressure on Wnt/Ca2? signaling. Real-time PCR and Western blotting results showed that pressure could activate the expression of Col-II, Sox9, and aggrecan in BMSCs cocultured with PRF. Blocking experiment found a positive role of Wnt/b-catenin signaling, and a negative role of Wnt/ Ca2? signaling in chondrogenic differentiation of the BMSCs. Mutual inhibition exists between canonical and noncanonical Wnt signaling in BMSCs under pressure. CONCLUSION: Wnt signaling participates in the pressure-promoted chondrogenesis of the BMSCs co-cultured with PRF, with canonical and noncanonical pathways playing distinct roles during the process.

Streptomyces lushanensis sp. nov., a novel actinomycete with anti-cyanobacterial activity

Zhang, Bing-Huo,Cheng, Juan,Chen, Wei,Li, Han-Quan,Yang, Jian-Yuan,Park, Dong-Jin,Kim, Chang-Jin,Shen, Rui,Duan, Yan-Qin,Li, Wen-Jun Nature Publishing Group 2015 The Journal of Antibiotics Vol. No.

<P>Strain JXJ 0135(T), an anti-cyanobacterial actinomycete, was isolated from a soil sample collected from Lushan Mountain, south China, and identified by using polyphasic approach. Phylogenetic analysis of the near-complete 16S rRNA gene sequence indicated that strain JXJ 0135(T) belongs to the genus Streptomyces and exhibited distinct subclade and also highest similarity (98.6%) to Streptomyces scopuliridis RB72(T). The strain developed well-branched substrate and aerial mycelia, and produced spiral spore chains. Spores were elliptical and the spore surface was smooth. The strain contained LL-diaminopimelic acid with whole-cell sugars of mannose, rhamnose, glucose and galactose. Phospholipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol mannosides, phosphotidylinositol dimannoside, an unidentified aminophospholipid and an unknown phospholipid. The menaquinones were MK-9(H6) and MK-9(H8). The major components of the fatty acids were anteiso-C15:0, iso-C16:0, anteiso-C17:0, iso-C15:0, C16:0, iso-C17:0 and iso-C14:0. The G+C content was 69.3?mol%. The DNA-DNA hybridization value between JXJ 0135(T) and S. scopuliridis RB72(T) was 41.21.4%. On the basis of the polyphasic data, strain JXJ 0135(T) represents a novel species of the genus Streptomyces, for which the name Streptomyces lushanensis sp. nov. is proposed. The type strain is JXJ 0135(T) (=DSM 42121(T)=JCM 19628(T)=KCTC 29261(T)=KACC 17834(T)=NRRL B-24994(T)).</P>

Systematic Analysis on the GSTM1 Null Phenotype and Prostate Cancer Risk in Chinese People

Shi, Jing,Zhuang, Yan,Liu, Yan,Yan, Cheng-Quan,Liu, Xian-Kui,Zhang, Ying Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.5

Objective: Glutathione S-transferase M 1 (GSTM1) is implicated as a risk factor for prostate cancer. However, this issue is not clear in Chinese population. This systemic analysis was conducted to evaluate the effect of GSTM1 null genotypes on prostate cancer risk in Chinese. Methods: Published studies investigating the associations between GSTM1 null genotypes and the risk of prostate cancer in China were identified by using a predefined search strategy. Main statisticals were pooled and estimated according to the primarily reported data. Results: The prevalence of the GSTM1 null genotype was higher in prostate cancer patients than in controls, with significance. Conclusion: The GSTM1 null genotypes is associated with increased risk of prostate cancer in Chinese.

Scutellarin protects against doxorubicin-induced acute cardiotoxicity and regulates its accumulation in the heart

Xi-Peng Sun,Li-Li Wan,Quan-Jun Yang,Yan Huo,Yong-Long Han,Cheng Guo 대한약학회 2017 Archives of Pharmacal Research Vol.40 No.7

The clinical use of doxorubicin (DOX) is limited by its dose-dependent cardiotoxicity. The present study investigated the effects of scutellarin against DOX-induced cardiotoxicity in rats using pharmacodynamic and pharmacokinetic approaches. DOX (20 mg/kg) was injected intraperitoneally (i.p.) as a single dose, and scutellarin (5 mg/kg/day) was injected intravenously (i.v.) for 3 days. Rats treated with DOX showed acute cardiotoxicity as indicated by the elevated serum lactate dehydrogenase (LDH) activity (4057.8 ± 107.2 vs. 2032.7 ± 70.95), tissue malondialdehyde (MDA) level (2.083 ± 0.10 vs. 1.103 ± 0.09), cardiac troponin T (cTnT) concentration (0.1695 ± 0.0114 ng/mL), the decreased left ventricular ejection fraction (LVEF) (47.75 ± 15.79 vs. 78.72 ± 7.25) and left ventricular fractional shortening (LVFS) (20.66 ± 8.06 vs. 43.7 ± 6.76) compared with those of the control group. Cotreatment with scutellarin significantly decreased the LDH activity (2595.9 ± 72.73), MDA level (1.380 ± 0.06), cTnT concentration (0.0222 ± 0.0041 ng/ m L), increased LVEF (76.70 ± 3.91) and LVFS (40.28 ± 3.68). Histopathological studies showed disruption of cardiac tissues in the DOX groups. Cotreatment with scutellarin reduced the damage to cardiac tissues. In the pharmacokinetic and tissue distribution study, scutellarin reduced the heart tissue exposure to DOX but did not change the AUC of plasma. These results suggest that scutellarin can protect against DOX-induced acute cardiotoxicity through its antioxidant activity and alterations of heart concentrations.

No Association Between the USP7 Gene Polymorphisms and Colorectal Cancer in the Chinese Han Population

Li, Xin,Wang, Yang,Li, Xing-Wang,Liu, Bao-Cheng,Zhao, Qing-Zhu,Li, Wei-Dong,Chen, Shi-Qing,Huang, Xiao-Ye,Yang, Feng-Ping,Wang, Quan,Wang, Jin-Fen,Xiao, Yan-Zeng,Xu, Yi-Feng,Feng, Guo-Yin,Peng, Zhi-Ha Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.5

Colorectal cancer (CRC), now the third most common cancer across the world, is known to aggregate in families. USP7 is a very important protein with an important role in regulating the p53 pathway, which is critical for genomic stability and tumor suppression. We here genotyped eight SNPs within the USP7 gene and conducted a case-control study in 312 CRC patients and 270 healthy subjects in the Chinese Han population. No significant associations were found for any single SNP and CRC risk. Our data eliminate USP7 as a potential candidate gene towards for CRC in the Han Chinese population.

Radiological gastrostomy: A comparative analysis of different image-guided methods

Hong-Tao Hu,Hang Yuan,Chen-Yang Guo,Quan-Jun Yao,Xiang Geng,Hong-Tao Cheng,Jun-Li Ma,Yan Zhao,Li Jiang,Yu-Qing Zhao,Hai-Liang Li 소화기인터벤션의학회 2021 International journal of gastrointestinal interven Vol.10 No.2

Background: Radiographic guided percutaneous gastrostomy has become a safe and effective enteral nutrition method for patients who can not eat by mouth. Fluoroscopy, computed tomography (CT) and cone-beam CT have been routinely used clinically. The aim of this study was to compare the advantages and disadvantages of percutaneous gastrostomy using different radiographic guided methods. Methods: We retrospectively analyzed the clinical data of 538 patients undergoing percutaneous gastrostomy in our department. According to the image guidance method used in gastrostomy, the patients were divided into groups A by fluoroscopy guidance, group B by fluoroscopy combined with C-arm CT guidance, and group C with the whole process CT guidance. The gastrostomy success rate, complication rate, procedure time, and patient radiation dose were analyzed in the three groups. Results: Among 538 patients, 534 were successful and the success rates are 94.3%, 99.3%, and 100% in group A, B, and C, respectively (P > 0.05). There were 3 cases occurred postoperative bleeding as serious adverse events and transferred to surgical gastrostomy. The minor complications include local infection, hyperplasia of granulation tissue, tube obstruction or prolapse, and local pain of the ostomy. The minor complication rates were 10.5%, 10.4%, and 7.7% in group A, B, and C, respectively (P > 0.05). The average procedure time was 25.57 ± 5.99 minutes, 29.01 ± 6.63 minutes, and 45.47 ± 8.98 minutes, respectively (χ2 = 87.98, P < 0.001). The average radiation dosage was 27.30 ± 19.27 mGy, 145.07 ± 106.08 mGy, and 2,590.26 ± 1,088.22 mGy, respectively (χ2 = 204.44, P < 0.001). Conclusion: There were no significant differences in the success rates and complication rates of gastrostomy under the three guiding methods. For difficult cases, CT-guided gastrostomy may be a very useful supplemental method.

Radiological gastrostomy: A comparative analysis of different image-guided methods

Hong-Tao Hu,Hang Yuan,Chen-Yang Guo,Quan-Jun Yao,Xiang Geng,Hong-Tao Cheng,Jun-Li Ma,Yan Zhao,Li Jiang,Yu-Qing Zhao,Hai-Liang Li 소화기인터벤션의학회 2021 Gastrointestinal Intervention Vol.10 No.2

Background: Radiographic guided percutaneous gastrostomy has become a safe and effective enteral nutrition method for patients who can not eat by mouth. Fluoroscopy, computed tomography (CT) and cone-beam CT have been routinely used clinically. The aim of this study was to compare the advantages and disadvantages of percutaneous gastrostomy using different radiographic guided methods. Methods: We retrospectively analyzed the clinical data of 538 patients undergoing percutaneous gastrostomy in our department. According to the image guidance method used in gastrostomy, the patients were divided into groups A by fluoroscopy guidance, group B by fluoroscopy combined with C-arm CT guidance, and group C with the whole process CT guidance. The gastrostomy success rate, complication rate, procedure time, and patient radiation dose were analyzed in the three groups. Results: Among 538 patients, 534 were successful and the success rates are 94.3%, 99.3%, and 100% in group A, B, and C, respectively (P > 0.05). There were 3 cases occurred postoperative bleeding as serious adverse events and transferred to surgical gastrostomy. The minor complications include local infection, hyperplasia of granulation tissue, tube obstruction or prolapse, and local pain of the ostomy. The minor complication rates were 10.5%, 10.4%, and 7.7% in group A, B, and C, respectively (P > 0.05). The average procedure time was 25.57 ± 5.99 minutes, 29.01 ± 6.63 minutes, and 45.47 ± 8.98 minutes, respectively (χ2 = 87.98, P < 0.001). The average radiation dosage was 27.30 ± 19.27 mGy, 145.07 ± 106.08 mGy, and 2,590.26 ± 1,088.22 mGy, respectively (χ2 = 204.44, P < 0.001). Conclusion: There were no significant differences in the success rates and complication rates of gastrostomy under the three guiding methods. For difficult cases, CT-guided gastrostomy may be a very useful supplemental method.