Characterization and functional analysis of fatty acid binding protein from the carcinogenic liver fluke, Opisthorchis viverrini

AbstractIn the present study, the cDNA encoding FABP (Ov-FABP) was isolated from the adult stage of Opisthorchis viverrini and characterized. The Ov-FABP protein sequence (107 amino acids) was predicted to have a molecular mass of 12.26kDa and an isoelectric point (PI) of 6.82. This sequence had a high identity and similarity to Cs-FABP of the related opisthorchid Clonorchis sinensis. Multiple sequence alignment with FABPs from other parasitic flatworms and mammals showed a number of conserved amino acids including Phe34, Gly37, Glu38, Glu39,Val50, Iso62, Gly81, Ile84, Ser87 and Arg101. In addition, the structure of Ov-FABP was predicted to have eleven β-sheets and one α-helix based on the known structures for FABPs from human (hL-FABP), rat and a schistosome. Phylogenetic analysis of amino acid sequence data revealed a close relationship of Ov-FABP with Cs-FABP and hL-FABP. Reverse transcription-PCR revealed that Ov-FABP was transcribed in the egg, metacercaria, juvenile and adult stages. The soluble form of recombinant Ov-FABP (rOv-FABP) was shown to specifically bind fatty acids, including oleic acid, palmitic acid and linoleic acid, as shown for other animals. Anti-serum against rOv-FABP (produced in mice) located the protein to parenchyma, egg, sucker musculature, testes and tegument of adult O. viverrini. Taken together, the findings suggest key functional roles for Ov-FABP in development, reproduction and/or host–parasite interactions

Soil-transmitted helminthiasis in Laos: A community-wide cross-sectional study of humans and dogs in a mass drug administration environment

We conducted a community cross-sectional survey of soil-transmitted helminthiasis in humans and dogs in four provinces in northern Laos. We collected and tested human and dog fecal samples and analyzed results against sociodemographic data. The prevalence of Ascaris lumbricoides, Trichuris trichiura, hookworm, and Strongyloides stercoralis was 26.1% (95% confidence interval [CI,1 = 23.7-28.4%), 41.5% (95% CI = 38.8-44.1%), 46.3% (95% CI = 43.3-49.0%), and 8.9% (95% CI = 7.4-10.4%), respectively. We observed strong heterogeneity for helminthiasis by ethnicity, province, and wealth status, which coincided with a risk profile demonstrating that Mon-Khmer persons and the poorest households are highly vulnerable. Necator americanus was the dominant hookworm species infecting humans and Ancylostoma ceylanicum was the only Ancylastoma species detected. Hookworm prevalence in village dogs was 94%, and the dominant species was A. ceylanicum. Necator americanus was also detected in dogs. It appears that dogs have a role in human hookworm transmission and warrant further investigation

Gene discovery for the carcinogenic human liver fluke, Opisthorchis viverrini

Background: Cholangiocarcinoma (CCA) - cancer of the bile ducts - is associated with chronic infection with the liver fluke, Opisthorchis viverrini. Despite being the only eukaryote that is designated as a 'class I carcinogen' by the International Agency for Research on Cancer, little is known about its genome.\ud \ud Results: Approximately 5,000 randomly selected cDNAs from the adult stage of O. viverrini were characterized and accounted for 1,932 contigs, representing ~14% of the entire transcriptome, and, presently, the largest sequence dataset for any species of liver fluke. Twenty percent of contigs were assigned GO classifications. Abundantly represented protein families included those involved in physiological functions that are essential to parasitism, such as anaerobic respiration, reproduction, detoxification, surface maintenance and feeding. GO assignments were well conserved in relation to other parasitic flukes, however, some categories were over-represented in O. viverrini, such as structural and motor proteins. An assessment of evolutionary relationships showed that O. viverrini was more similar to other parasitic (Clonorchis sinensis and Schistosoma japonicum) than to free-living (Schmidtea mediterranea) flatworms, and 105 sequences had close homologues in both parasitic species but not in S. mediterranea. A total of 164 O. viverrini contigs contained ORFs with signal sequences, many of which were platyhelminth-specific. Examples of convergent evolution between host and parasite secreted/membrane proteins were identified as were homologues of vaccine antigens from other helminths. Finally, ORFs representing secreted proteins with known roles in tumorigenesis were identified, and these might play roles in the pathogenesis of O. viverrini-induced CCA.\ud \ud Conclusion: This gene discovery effort for O. viverrini should expedite molecular studies of cholangiocarcinogenesis and accelerate research focused on developing new interventions, drugs and vaccines, to control O. viverrini and related flukes

High macrophage activities are associated with advanced periductal fibrosis in chronic Opisthorchis viverrini infection

Liver fluke infection caused by Opisthorchis viverrini induces several hepatobiliary conditions including advanced periductal fibrosis (APF ) and cholangiocarcinoma (CCA ), but >25% of the infected population develops APF and 1% develop CCA . The innate immune response is the first line of defence, and macrophages are critical regulators of fibrosis. We hypothesized that macrophages from infected individuals have different capacities to either promote or suppress periductal fibrosis. We compared phagocytic activities of macrophages of healthy individuals and O viverrini‐ infected individuals ± APF , and found that macrophages from infected individuals with APF ingested significantly higher numbers of beads compared with healthy controls and O viverrini‐ infected individuals without APF . To further investigate proteolytic activity, we monitored real‐time phagosomal proteolysis of beads conjugated to DQ ‐BODIPY ‐BSA using live cell imaging. We show that macrophages from O viverrini‐ infected individuals with APF also have elevated phagosomal proteolysis activity, which is consistent with their increased phagocytic activity. Additionally, stimulated ROS production by blood monocytes was higher in individuals with APF compared with healthy controls and infected individuals without APF . These results suggest that during O viverrini infection, macrophages with high phagocytic and proteolytic activities together with elevated ROS production are the phenotypes that can promote tissue damage, which results in periductal fibrosis

Suppression of NAD(P)H-quinone oxidoreductase 1 enhanced the susceptibility of cholangiocarcinoma cells to chemotherapeutic agents

La lateralidad de la jugadora con el rol de base puede ser sólo una característica individual, o bien un factor influyente en el juego de su equipo, y por tanto, una herramienta a considerar por parte del equipo rival. El trabajo de investigación se centra en la necesidad de reflejar si la lateralidad de una jugadora con rol de base en baloncesto, al iniciar la acción de juego (bote o pase) influye de manera determinante en la toma de decisiones. El contexto de trabajo utilizado es la segunda categoría de baloncesto femenino nacional, Liga Femenina 2. En la observación han participado varios equipos de dicha categoría, con total de 10 partidos analizados y un total de 170 situaciones de juego analizadas (N=170). Para establecer las relaciones entre las variables se utilizó el Coeficiente de Contingencia. Los resultados muestran una relación estadísticamente significativa de la lateralidad de la base y el lado del campo en el que se empieza a jugar (X2 (1, N=170) = 4.789, p<.05)Laterality of the point-guard can be an individual characteristic, or in the other hand, an important factor in the offensive patterns of the team. In this way, it will be a useful information for the other team. This research has focused in the laterality of the point guard, and it influences in the decision making. The League studied was the second female Spanish basketball league, LF2. 10 matches were observed and 170 game situations analyzed (N=170). Crosstabs Command and the Contingency Coefficient were used to establish the relationship between variables. The results shows a significant relationship between the laterality of the point guard and the side of the field where the attack begin (X2 (1, N=170) = 4.789, p<.05)peerReviewe

Ultrastructural characters of the spermatozoon of the liver fluke Opisthorchis viverrini (Poirier, 1886) (Opisthorchiidae)

The present study records the ultrastructural organization of the mature spermatozoon of Opisthorchis viverrini by means of transmission electron microscopy. The spermatozoon of O. viverrini is a filiform cell, tapered at both extremities. It exhibits the characteristics of type IV spermatozoon of digeneans, namely with two axonemes of the 9+'1' trepaxonematan pattern, external ornamentation of the plasma membrane associated with cortical microtubules that are in the posterior part of the anterior region of the sperm cell, and with two mitochondria. The maximal number of cortical microtubules is in the anterior part of the spermatozoon and arranged into two bundles. Other characteristics are spine-like bodies and a posterior extremity with only the second axoneme. Ultrastructural characters of the spermatozoon of O. viverrini are compared with those of other known digeneans belonging to the Opisthorchioidea, with particular emphasis on representatives of the family Opisthorchiidae. The main differences between O. viverrini and its congener Opisthorchis felineus are the spine-like bodies (present and absent, respectively) and the posterior spermatozoon character (axoneme and nucleus, respectively)

Elevated Plasma IL-6 Associates with Increased Risk of Advanced Fibrosis and Cholangiocarcinoma in Individuals Infected by Opisthorchis viverrini

Opisthorchis viverrini is considered among the most important of the food-borne trematodes due to its strong association with advanced periductal fibrosis and bile duct cancer (cholangiocarcinoma). We investigated the relationship between plasma levels of Interleukin (IL)-6 and the risk of developing advanced fibrosis and bile duct cancer from chronic Opisthorchis infection. We show that IL-6 circulates in plasma at concentrations 58 times higher in individuals with advanced fibrosis than age, sex, and nearest-neighbor matched controls and 221 times higher in individuals with bile duct cancer than controls. We also observed a dose-response relationship between increasing levels of plasma IL-6 and increasing risk of advanced fibrosis and bile duct cancer; for example, in age and sex adjusted analyses, individuals with the highest quartiles of plasma IL-6 had a 19 times greater risk of developing advanced periductal fibrosis and a 150 times greater risk of developing of bile duct cancer than individuals with no detectable level of plasma IL-6. Finally, we show that a single plasma IL-6 measurement has excellent positive predictive value for the detection of both advanced bile duct fibrosis and bile duct cancer in regions with high O. viverrini transmission. These data support our hypothesis that common mechanisms drive bile duct fibrosis and bile duct tumorogenesis from chronic O. viverrini infection. Our study also adds a unique aspect to the literature on circulating levels of IL-6 as an immune marker of hepatobiliary pathology by showing that high levels of circulating IL-6 in plasma are not related to infection with O. viverrini, but to the development of the advanced and often lethal pathologies resulting from chronic O. viverrini infection

Opisthorchiasis-associated biliary stones: light and scanning electron microscopic study

Aim: Biliary stones are frequently encountered in areas endemic for opisthorchiasis in Thailand. The present study was to describe the prevalence and pathogenesis of these stones. Methods: Gallstones and/or common bile duct stones and bile specimens from 113 consecutive cholecystectomies were included. Bile samples, including sludge and/or microcalculi, were examined for Opisthorchis viverrini eggs, calcium and bilirubin. The stones were also processed for scanning electron microscopic (SEM) study. Results: Of the 113 cases, 82 had pigment stones, while one had cholesterol stones. The other 30 cases had no stones. Most of the stone cases (76%, 63/83) had multiple stones, while the remainder had a single stone. Stones were more frequently observed in females. Bile examination was positive for O. viverrini eggs in 50% of the cases studied. Aggregates of calcium bilirubinate precipitates were observed in all cases with sludge. Deposition of calcium bilirubinate on the eggshell was visualized by special staining. A SEM study demonstrated the presence of the parasite eggs in the stones. Numerous crystals, morphologically consistent with calcium derivatives and cholesterol precipitates, were seen. Conclusion: Northeast Thailand has a high prevalence of pigment stones, as observed at the cholecystectomy, and liver fluke infestation seems involved in the pathogenesis of stone formation. Copyrigh