Dongsup Lee

Cyanidin 3-O-Glucoside Reduces Helicobacter pylori VacA-Induced Cell Death of Gastric KATO III Cells through Inhibition of the SecA Pathway

Two key virulence factors of Helicobacter pylori are the secreted virulent proteins of vacuolating toxin A (VacA) and cytotoxin associated protein A (CagA) which lead to damages of gastric epithelial cells. We previously identified that the cyanidin 3-O-glucoside (C3G) inhibits the secretion of both VacA and CagA. In the current report, we show that C3G inhibits VacA secretion in a dose-dependent manner by inhibiting secretion system subunit protein A (SecA) synthesis. As SecA is involved in translocation of bacterial proteins, we predicted that inhibition of the SecA pathway by C3G should decrease H. pylori-induced cell death. To test this hypothesis, the human gastric cell line KATO III cells were co-cultured with H. pylori 60190 (VacA+/CagA+) and C3G. We found that C3G treatment caused a decrease in activation of the pro-apoptotic proteins caspase-3/-8 in H. pylori-infected cells leading to a decrease in cell death. Our data suggest that consumption of foods containing anthocyanin may be beneficial in reducing cell damage due to H. pylori infection.

Human Papillomavirus Distribution among Women in Western Shandong Province, East China using Reverse Blot Hybridization Assay

Cervical cancer is the third most common cancer in women worldwide and there is a significant association between human papillomavirus (HPV) infection and cervical cancer. Certain HPV groups, labeled high-risk (HR) HPV groups, are strongly associated with malignancies of the human cervix. HPV prevalence and genotype distribution were analyzed using the REBA HPV-ID ® (YD Diagnostics, Yongin, Korea) assay based on the reverse blot hybridization assay (REBA) with a total of 324 liquid-based cytology samples from women in Western Shandong Province, East China and results were compared with cytological diagnosis. Most of the HPV genotypes that were detected in high-grade cervical lesions were HR-HPV genotypes such as HPV 16, 18, 33, 53, and 58. The prevalence of these HR-HPV genotypes increased in high-grade cervical lesions. However, from low- to high-grade cervical lesions, the ability to detect LR-HPV genotypes decreased. Additionally, in general, the single HPV genotype infection rate increases in proportion to the severity of the lesion. The study findings suggest that a currently available preventive vaccine against HPV 16 and 18 may have limited effectiveness for prevention of all HPV infection in this province. Finally, based on these findings, these data could guide national or regional vaccination programs in the Western Shandong Province of East China to substantially reduce the burden of cervical lesions.

Triglyceride Up-regulates Expression of ABCG1 in PMA-induced THP-1 Macrophages Through Activation of JNK and p38 MAPK Pathways

Triglyceride (TG) can cause death of macrophages and formation of foam cells thereby increasing inflammation in atherosclerotic plaques. Accumulation of cholesterol in macrophages is another critical event that promotes development of inflammatory cardiovascular diseases. Several proteins are known to transport intracellular cholesterol outside of the cell and these proteins are thought to be protective against atherosclerosis pathogenesis. It is unknown whether TG can affect cholesterol efflux in macrophages. In the current study, we examined mRNA expression levels of genes that promote efflux of cholesterol (ABCA1, ABCG1 and SR-B1). We found that TG treated THP-1 macrophages exhibited an increase in ABCG1 expression in a dose- and time-dependent manner. In contrast, the expression of ABCA1 and SR-B1 remained unchanged. To identify cell signaling pathways that participate in up-regulation of ABCG1, THP-1 macrophages were treated with various cell signaling inhibitors. We found that inhibition of the JNK and p38 MAPK pathway completely abrogated up-regulation of ABCG1 whereas inhibition of MEK1 further enhanced ABCG1 expression in TG treated THP-1 macrophages. Also, TG induced phosphorylation of JNK and p38 MAPK in THP-1 macrophages. These results suggest that TG may potentially influence cholesterol efflux in macrophages.

Human Papillomavirus Prevalence and Genotype Distribution in Normal and ASCUS Specimens: Comparison of a Reverse Blot Hybridization Assay with a DNA Chip Test

High-risk (HR) human papillomavirus (HPV) genotypes are strongly associated with cervical cancer, whereas other HPV genotypes are not. To identify the various HPV genotypes in clinical samples, we conducted HPV genotyping using a DNA chip test and reverse blot hybridization assay (REBA) in normal cytology samples and atypical squamous cells of undetermined significance (ASCUS) cytology samples. We also investigated the HPV infection rate and HPV genotype prevalence in women with normal cytology and ASCUS cytology. Liquid-based cytology preparations were used for the initial screening of 205 subjects with normal cytology and ASCUS cytology. The HPV infection rate was 49.8% when using the DNA chip assay and 61.0% when using the REBA test. In patients with normal cytology, the HR-HPV positive rate was 21.9% with the DNA chip assay and 43.9% with the REBA test. In contrast, 8.3% of patients with ASCUS were HR-HPV positive when using the DNA chip assay, and 13.6% were positive when tested with the REBA test. The infection rate of HR-HPV in the 40~50-year age group was significantly higher than that of the other age groups. Based on the cytological analysis of the normal and ASCUS samples, the five most prominent HPV genotypes were HPV 16, 18, 68, 33, and 58 using the DNA chip test, and they were HPV 16, 18, 53, 33, and 66 when using the REBA test. In conclusion, the findings show that the results of the REBA test are comparable to those of the DNA chip test. Most strikingly, the REBA test detected the HR-HPV genotype associated with cervical carcinoma similar to that detected with the DNA chip method. Therefore, the REBA test is a useful method to detect clinically important HR-HPV genotypes.

Anti-biofilm and Anti-Virulence Efficacy of Celastrol Against Stenotrophomonas maltophilia

Stenotrophomonas maltophilia is a multi-drug resistant opportunistic pathogen that causes nosocomial infections in immunocompromised patients. This pathogen is difficult to treat owing to its intrinsic multidrug resistance and ability to form antimicrobial-tolerant biofilms. In the present study, we aimed to assess the potential use of celastrol as a novel anti-biofilm and/or anti-virulence agent against S. maltophilia. Results showed that celastrol at its sub-inhibitory doses decreased biofilm formation and disrupt the established biofilms produced by S. maltophilia. Celastrol-induced decrease in biofilm formation was dose-dependent based on the results of the microtiter plate biofilm assays and confocal laser scanning microscopy. In addition, our data validated the anti-virulence efficacy of celastrol, wherein it significantly interfered with the production of protease and motility of S. maltophilia. To support these phenotypic results, transcriptional analysis revealed that celastrol down-regulated the expression of biofilm- and virulence- associated genes (smeYZ, fsnR, and bfmAK) in S. maltophilia. Interestingly, celastrol significantly inhibited the expression of smeYZ gene, which encodes the resistance-nodulation-division (RND)-type efflux pump, SmeYZ. Overall, our findings suggested that celastrol might be a promising bioactive agent for treatment of biofilm- and virulence-related infections caused by the multi-drug resistant S. maltophilia.

Comparison of FFPE histological versus LBP cytological samples for HPV detection and typing in cervical cancer

Human papillomavirus (HPV) infection is closely associated with cervical cancer. This study analyzed HPV genotype prevalence in 75 cases of formalin-fixed paraffin embedded (FFPE) tissue samples from patients diagnosed with cervical cancer. Genotype prevalence was assessed using Reverse Blot Assay (REBA) and quantitative polymerase chain reaction (qPCR), which target the HPV L1 and HPV E6/E7 genes, respectively. HPV DNA chip tests were also performed using liquid based preparation (LBP) cytological samples from the same patients who provided the FFPE histological samples. We observed a slight difference in HPV genotype distribution as assessed by DNA chip versus REBA. One possible explanation for this difference is that normal regions could be mixed with lesion regions when cytological samples are extracted from each patient with cancer. For the detection of moderate dysplasia, the main target of diagnosis, this difference is anticipated to be greater. We also made several unexpected observations. For example, HPV multi-infection was not detected. Moreover, the rate of HPV positivity varied radically depending on the cancer origin, e.g. squamous cell carcinoma versus adenocarcinoma. Our results imply that it is important to determine whether cytological specimens are suitable for HPV genotyping analysis and cervical cancer diagnosis. Future research on the mechanisms underlying cervical cancer pathogenesis is also necessary.

Performance of HPV E6/E7 mRNA Genotyping Test on Paired Cervical Cancer Exfoliated Cells and Formalin Fixed Paraffin Embedded Tissues

Investigation of human papillomavirus (HPV) in archival formalin-fixed paraffin-embedded (FFPE) material is important for understanding cervical carcinogenesis. The objective of the present study was to identify the high risk HPVs (HR-HPVs) using HPV E6/E7 mRNA testing from archival tissues in cervical cancer and the relation to HR-HPVs genotypes in paired cervical exfoliated cells. HPV E6/E7 mRNA testing and DNA chip testing were performed in 79 paired cervical FFPE tissues and exfoliated cells from women with histologically confirmed squamous cell carcinoma and adenocarcinoma. Overall agreement in HR-HPVs detection from FFPE samples and cytology samples were 98.5% in HPV 16, 100% in HPV 18, HPV 31, HPV 33, HPV 58, HPV 66, and HPV 68. Type-specific agreement between FFPE samples and cytology samples was 89.1% in HPV positive, 93.5% in HPV 16 and more than 70% in the other HR-HPVs. In conclusion, HR-HPVs were reliably detected in paired FFPE and cytology samples with some variation in type-specific detection.

Distribution of Oncogenic Human Papillomavirus Genotypes at High Grade Cervical Lesions above CIN 2 Grade with Histological Diagnosis

High risk human papillomavirus (HR-HPV) is major risk factor for uterine cervical cancer. There are approximately 15 types of HR-HPV. Liquid based cytology samples (116 samples) with high grade cervical lesions belonging to cervical intraepithelial neoplasia (CIN) 2, CIN 3, carcinoma in situ (CIS) and squamous cell carcinoma (SCC) were used after histologic confirmation. HR-HPV genotype assay was conducted using DNA chips. The HR-HPV infection rate was 81.9% with SCC samples showing the highest HR-HPV infection rate of 31%. CIN 3, CIS and CIN 2 showed infection rates of 25%, 16.4% and 9.5%, respectively. According to age with HR HPV infection rate, the 30~39 years-old group showed the highest infection rate by 92.3%. According to distribution with HR HPV genotyping, HPV 16 showed the highest infection rate by 42.3% whereas HPV 33 and HPV 58 showed infection rates of 11.7% and 10.8%, respectively. HPV 18 which is the second most common infected HPV genotype in the world showed 3.6%. Of the three most common oncogenic HR-HPV genotypes in CIN 2, we detected HPV 16, 35, 58; CIN 3 was HPV 16, 33, 58; CIS was HPV 16, 58, 33 (35/52); and SCC was HPV 16, 33, and 18 (31/52/58). Among the HPV 18, CIN 2, CIN 3, CIS and SCC showed 0.9%, 0.9%, 0% and 1.8%, respectively. The most often used preventive vaccines for cervical cancers use HPV 16 and HPV 18 as targets. However, results derived from this study suggest that a preventive vaccine against HPV 16 and HPV 18 would not be optimal for populations in this study.