D101 is critical for the function of AttJ, a repressor of quorum quenching system in Agrobacterium tumefaciens

Chao Wang,Chunlan Yan,Yong-Gui Gao,Lian-Hui Zhang 한국미생물학회 2015 The journal of microbiology Vol.53 No.9

The quorum quenching system of Agrobacterium tumefaciens is specifically activated upon entering the stationary phase. Evidence has shown that this system includes two key components: the IclR-type transcriptional factor AttJ (also named as BlcR) and the AHL-lactonase AttM (also named as BlcC). At exponential phase, AttJ binds to the promoter region of attM and thus suppresses the expression of attM. At stationary phase, however, the small molecule SSA directly binds to AttJ and relieves its inhibition of AttJ and thereby triggers the expression of attM. While the regulation of AttM has been extensively investigated, little is known about the regulation of AttJ. In this study, we demonstrated the D101 amino acid of AttJ is essential for the AttJ function. In vitro, the variant protein of AttJD101H appeared to be readily aggregated. In vivo, the D101H mutation in AttJ entirely abolished the inhibitory activity of AttJ and overexpressed attM in A. tumefaciens A6. In addition, D101H mutation led to an overexpression of attJ, indicating an auto-regulatory mechanism for the attJ regulation. Put together, these findings demonstrate that D101 is an important amino acid for the transcription activity of AttJ and the transcription of attJ is regulated by a negative feedback loop. These results expand previous biochemical characterization of AttJ and provide new mechanistic insights into the regulation of quorum quenching in A. tumefaciens.

Characteristics of Imported Malaria and Species of Plasmodium Involved in Shandong Province, China (2012-2014)

Chao Xu,Qing-Kuan Wei,Jin Li,Ting Xiao,Kun Yin,Chang-Lei Zhao,Yong-Bin Wang,Xiang-Li Kong,Gui-Hua Zhao,Hui Sun,Xin Liu,Bing-Cheng Huang 대한기생충학열대의학회 2016 The Korean Journal of Parasitology Vol.54 No.4

Epidemiological Investigation of Asymptomatic Dogs with Leishmania Infection in Southwestern China Where Visceral Leishmaniasis is Intractable

Gui-Hua Zhao,Kun Yin,Wei-Xia Zhong,Ting Xiao,Qing-Kuan Wei,Yong Cui,Gong-Zhen Liu,Chao Xu,Hong-Fa Wang 대한기생충학열대의학회 2016 The Korean Journal of Parasitology Vol.54 No.6

Heishui county, located in northwest Sichuan province, southwestern China, is an endemic area of zoonotic visceral leishmaniasis (VL) and is the most intractable area. VL is never destroyed in it. Asymptomatic dogs (Leishmania parasites have been diagnosed but clinically healthy) are considered to be a potential reservoir host in zoonotic VL area, and most can lead to infection of individuals, that is a new challenge for controlling VL in humans. The present study aimed to assess the Leishmania infection rate of asymptomatic dogs in Heishui county. Total 105 asymptomatic domestic dogs were gathered from 4 districts in Heishui county to investigate the infection rate with serological and molecular methods based on ELISA and kinetoplast minicircle DNA(kDNA) PCR, respectively. Out of 105 dogs, 44 (41.9%) were positive by more than 1 method; 21 (20.0%) were positive by ELISA, and 30 (28.6%) were positive by kDNA-PCR. Our study showed that Leishmania infection of domestic dogs which is clinically healthy is prevalent in the studied district, and the asymptomatic dogs infected by Leishmania may be the primary reason for the prevalence of visceral leishmaniasis in the area.

Expression of three neuropeptide genes (SfEH, SfETH, and SfCCAP) in response to insecticide stress on the white-backed planthopper Sogatella furcifera (Hemiptera: Delphacidae)

Long Gui-yun,Wang Zhao,Yang Jia-peng,Tang Chen-hong,Jin Dao-Chao,Yang Hong,Zhou Cao,Yang Xi-bin 한국응용곤충학회 2023 Journal of Asia-Pacific Entomology Vol.26 No.3

Insect neuropeptides are involved in many important developmental processes. Here, we cloned three neuro peptide genes (SfEH, SfETH, and SfCCAP) from Sogatella furcifera (Horváth) and analyzed the relative expression levels of these genes through Real-time Quantitative polymerase chain reaction (RT-qPCR) during different developmental stages and in different wing types of S. furcifera following exposure to sublethal concentrations (LC 10 and LC 25 ) of methylaminoavermectin benzoate. The results revealed that the three neuropeptide genes (SfEH, SfETH, and SfCCAP) of S. furcifera contained open reading frame sequences of 222, 636, and 408 bp, encoding 73, 211, and 135 amino acids, respectively. Moreover, the expression of SfEH and SfETH reached its peak on day 3 of the 5 th instar nymph stage, while the SfCCAP expressed pinnacle on 40 min after eclosion. Furthermore, the relative expression levels of the three genes were in the following order: SfEH, short-winged female > long-winged female > long-winged male; SfETH, long-winged female > short-winged female > longwinged male; and SfCCAP, short-winged female > long-winged male > short-winged female. Upon calculating the relative expression of the three peptide genes after 24 and 48 h of treatment with sublethal concentrations of methylaminoavermectin benzoate, it was found that the relative mRNA expression levels of SfEH and SfETH declined upon LC 10 treatment but increased upon LC 25 treatment. Meanwhile, the relative mRNA expression level of SfCCAP declined upon both LC 10 and LC 25 treatments. This result will help us understand the effects of pesticides on insect growth and development at the molecular level.

Sublethal effects of buprofezin on development, reproduction, and chitin synthase 1 gene (SfCHS1) expression in the white-backed planthopper, Sogatella furcifera (Hemiptera: Delphacidae)

Zhao Wang,Cao Zhou,Gui-yun Long,Hong Yang,Dao-chao Jin 한국응용곤충학회 2018 Journal of Asia-Pacific Entomology Vol.21 No.2

The white-backed planthopper, Sogatella furcifera (Horváth) (Hemiptera: Delphacidae), is a major rice pest in some Asia-Pacific countries. Buprofezin is an insect growth regulator with relatively low mammalian toxicity but high efficacy to many rice pests. In this study, we estimated the toxicity of buprofezin against 3rd-instar nymphs of S. furcifera using the rice-stem dipping method. The results showed that the LC50 of buprofezin to 3rd-instar nymphs were 0.89 mg/L. When 3rd-instar nymphs were exposed to the LC10 and LC25 (0.10 and 0.28 mg/L) of buprofezin, the duration of juvenile development was significantly prolonged in the F0 and F1 generations. The fecundity (eggs per female) of the F1 females was reduced by 5.29% and 12.34%, respectively, in addition to the survival rate, emergence rate, copulation rate, and hatchability were decreased by treatment with buprofezin at LC10 and LC25, compared with the control group. The relative fitness of S. furcifera in LC10 and LC25 treatments was reduced by 47% and 63%, respectively. Furthermore, real-time quantitative PCR analyses revealed increased the expressions of SfCHS1 and its two variants following the exposure of nymphs to buprofezin. Increased these genes mRNA levels associated with reduced chitin biosynthesis may result from the inhibition of chitin synthase activity, and thereby leading to a higher mortality of S. furcifera. Overall, sublethal concentrations of buprofezin suppressed the population growth of S. furcifera.

Genetic Variations in the HIF1A Gene Modulate Response to Adjuvant Chemotherapy after Surgery in Patients with Colorectal Cancer

Zhang, Yi,Wang, Peng,Zhou, Xing-Chun,Bao, Guo-Qiang,Lyu, Zhuo-Ming,Liu, Xiao-Nan,Wan, Shao-Gui,He, Xian-Li,Huang, Qi-Chao Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.11

Background: Hypoxia-inducible factor $1{\alpha}$ (HIF-$1{\alpha}$) plays an important role in regulating cell survival and angiogenesis, which are critical for tumor growth and metastasis. Genetic variations of HIF1A have been shown to influence the susceptibility to many kinds of human tumors. Increased expression of HIF-$1{\alpha}$ has also been demonstrated to be involved in tumor progression. However, the prognostic value of single nucleotide polymorphisms (SNPs) inthe HIF1A gene remains to be determined in most cancer types, including colorectal cancer (CRC). In this study, we sought to investigate the predictive role of HIF1A SNPs in prognosis of CRC patients and efficacy of chemotherapy. Materials and Methods: We genotyped two functional SNPs in HIF1A gene using the Sequenom iPLEX genotyping system and then assessed their associations with clinicopathological parameters and clinical outcomes of 697 CRC patients receiving radical surgery using Cox logistic regression model and Kaplan Meier curves. Results: Generally, no significant association was found between these 2 SNPs and clinical outcomes of CRC. In stratified analysis of subgroup without adjuvant chemotherapy, patients carrying CT/TT genotypes of rs2057482 exhibited a borderline significant association with better overall survival when compared with those carrying CC genotype [Hazard ratio (HR), 0.47; 95% confidence interval (95% CI): 0.29-0.76; P < 0.01]. Moreover, significant protective effects on CRC outcomes conferred by adjuvant chemotherapy were exclusively observed in patients carrying CC genotype of rs2057482 and in those carrying AC/CC genotype of rs2301113. Conclusions: Genetic variations in HIF1A gene may modulate the efficacy of adjuvant chemotherapy after surgery in CRC patients.

Complete mitochondrial genome of a kind of snakehead fish Channa siamensis and its phylogenetic consideration

Rui Li,Gang Wang,Zheng‑Yong Wen,Yuan‑Chao Zou,Chuan‑Jie Qin,Yu Luo,Jun Wang,Gui‑Hong Chen 한국유전학회 2019 Genes & Genomics Vol.41 No.2

The snakehead fish, Channa siamensis, belongs to the genus of Channa (perciformes: Channidae) and was first reported by Günther in 1861. Despite it has been described approximately for 15 decades, the genetic information is limited and the taxon status of this kind of fish is still unclear. The primary objective of this study is to get more genomic data and calculate the taxon location of this kind of fish. The next generation sequencing method was used to obtain the whole mitochondrial DNA information, and bioinformatic analysis was performed to investigate the evolutionary status and taxon location of C. siamensis. The circular mitochondrial DNA was 16,570 bp in length, and which showed typical piscine structure and arrangement. The overall nucleotide composition was 29.28% A, 24.72% T, 30.71% C, 15.29% G, with 54.1% AT, respectively. Phylogenetic analyses using concatenated amino acid and nucleotide sequences of the 13 protein-coding genes with two different methods (Maximum likelihood and Bayesian analysis) both highly supported C. siamensis belongs to the genus Channa and shows a close relationship with C. micropeltes. These data will provide more useful information for a better understanding of the mitochondrial genomic diversities and evolution in fish as well as novel genetic markers for studying population genetics and species identification.

Analysis of Indoleamine 2-3 Dioxygenase (IDO) and EGFR Co-expression in Breast Cancer Tissue by Immunohistochemistry

Bi, Wei-Wei,Zhang, Wei-Hua,Yin, Gui-Hua,Luo, Hong,Wang, Shou-Qin,Wang, Hongran,Li, Chao,Yan, Wei-Qun,Nie, De-Zhi Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.14

Background: To determine the amount of co-expression of IDO and EGFR in breast cancer patients. Materials and Methods:In order to obtain the distribution of co-expression of IDO and EGFR in breast cancer, we tested 110 breast cancer paraffin tissue blocks with immunohistochemical methods. Then we investigated the relationship between the diagnostic and pathologic characteristics (tumor size, lymph node status, histologic grade, the gene expression of ER, PR, HER2, p53, Ki67 and PCNA) with the situation of co-expression of IDO and EGFR by reviewing the medical records of 32 breast cancer patients. Results: Among 110 breast cancers, 32 cases demonstrated IDO and EGFR co-expression (29.1%), IDO and EGFR synchronous co-expression being found in 19.1% and asynchronous in 10.0%. Conclusions: IDO and EGFR were co-expressed in breast cancer, including synchronous and asynchronous co-expression. The results suggest that considering IDO and EGFR as two indicators for breast cancer treatment or prognosis analysis provides a potential option of individual treatment for the portion of breast cancer patients with co-expression of IDO and EGFR.

KLF4 Expression Correlates with the Degree of Differentiation in Colorectal Cancer

( Ruo Lei Hu ),( Yan Zuo ),( Li Zuo ),( Chao Liu ),( Su Mei Zhang ),( Qiang Wu ),( Qing Zhou ),( Shu Yu Gui ),( Wei Wei ),( Yuan Wang ) 대한소화기기능성질환·운동학회 2011 Gut and Liver Vol.5 No.2

Background/Aims: Kruppel-like factor 4 (KLF4) is an epithelial-specifi c transcription factor primarily expressed in the gastrointestinal tract that mediates growth arrest in the colonic epithelium. We tried to find whether KLF4 expression is associated with the progression and differentiation of colorectal cancer. Methods: We detected KLF4 expression in 109 colorectal specimens (40 normal appearing mucosa, 7 adenomas, and 62 carcinomas) by immunohistochemistry using a tissue microarray. Western blot and RT-PCR analyses were also performed. Results: The upregulation of KLF4 expression in carcinoma tissue was statistically significant (p<0.05) when compared to normal appearing mucosa. The negative and weak positive staining rates in normal appearing mucosa, adenoma, and carcinoma were 42.5%, 71.4%, and 82.3%, respectively, indicating a decreased degree of KLF4 expression over the course of progressive transformation of normal cells into malignant derivatives. KLF4 protein levels showed no correlation with sex, age, or metastatic state (p>0.05), while KLF4 protein expression correlated with the diagnostic stage (p<0.05). Furthermore, strong KLF4 staining was detected in 22.9% (11/48) and 0% (0/14) of well/moderately and poorly differentiated colorectal cancers, respectively. Our results clearly indicate that KLF4 protein expression signifi cantly correlates with the degree of differentiation in colorectal cancers (p<0.05). KLF4 expression in RKO cells is also upregulated by butyrate, an inducer of differentiation. Conclusions: Downregulation of KLF4 expression may lead to more poorly differentiated tumors. (Gut Liver 2011;5:154-159)

Sublethal effects of abamectin on the development, fecundity, and wing morphs of the brown planthopper Nilaparvata lugens

Hong Yang,Cao Zhou,Dao-chao Jin,Ming-fu Gong,Zhao Wang,Gui-yun Long 한국응용곤충학회 2019 Journal of Asia-Pacific Entomology Vol.22 No.4

The brown planthopper Nilaparvata lugens negatively affects rice yield by sucking nutrients from the rice stem and spreading viruses. In this study, the effects of sublethal concentrations of abamectin on development, fecundity, and wing morphs of N. lugens were investigated. Treatment with sublethal concentrations of abamectin showed no significant effects on the developmental period of F 0 nymphs. Although LC 10 and LC 25 treatments resulted in 10% and 25% mortality, the LC 25 treatment significantly prolonged the lifespan of macropterous and brachypterous females. Abamectin-treated brachypterous females showed significantly lower fecundity than control females. Furthermore, abamectin treatment showed no significant effects on the developmental period of F 1 nymphs. However, LC 25 treatment significantly inhibited the fecundity of brachypterous F 1 females and significantly reduced the proportion of macropterous F 1 females and brachypterous F 1 males. LC 25 treatment showed no significant effects on the fecundity of macropterous F 1 females. Considering the proportion of macropterous and brachypterous F 1 females, the relative fitness of the macropterous F 1 nymphs in the control, LC 10 , and LC 25 treatment groups was 1, 1.02, and 0.84, respectively, and that of brachypterous F 1 nymphs was 1, 0.79, and 0.93, respectively. Sublethal concentrations of abamectin inhibited N. lugens emergence. The present findings indicate the potential of abamectin for N. lugens field control.