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Granulins are a family of protein growth factors that are involved in cell proliferation. An orthologue of granulin from the human parasitic liver fluke Opisthorchis viverrini, known as Ov-GRN-1, induces angiogenesis and accelerates wound repair. Recombinant Ov-GRN-1 production is complex and poses an obstacle for clinical development. To identify the bioactive region(s) of Ov-GRN-1, four truncated N-terminal analogues were synthesized and characterized structurally using NMR spectroscopy. Peptides that contained only two native disulfide bonds lack the characteristic granulin β-hairpin structure. Remarkably, the introduction of a non-native disulfide bond was critical for formation of β-hairpin structure. Despite this structural difference, both two and three disulfide-bonded peptides drove proliferation of a human cholangiocyte cell line and demonstrated potent wound healing in mice. Peptides derived from Ov-GRN-1 are leads for novel wound healing therapeutics, as they are likely less immunogenic than the full-length protein and more convenient to produce. [ABSTRACT FROM AUTHOR]

Bithynia siamensis goniomphalos is a freshwater snail that serves as the first intermediate host of the human liver fluke Opisthorchis viverrini. This parasite is a major public health problem in different countries throughout the Greater Mekong sub-region (Thailand, southern Vietnam, Lao PDR and Cambodia). Chronic O. viverrini infection also results in a gradual increase of fibrotic tissues in the biliary tract that are associated with hepatobiliary diseases and contribute to cholangiocarcinoma (a fatal type of bile duct cancer). Infectivity of the parasite in the snail host is strongly correlated with destruction of helminths by the snail’s innate immune system, composed of cellular (hemocyte) and humoral (plasma) defense factors. To better understand this important host-parasite interface we applied sequential window acquisition of all theoretical spectra mass spectrometry (SWATH-MS) to identify and quantify the proteins from the hemolymph of B. siamensis goniomphalos experimentally infected with O. viverrini and compare them to non-infected snails (control group). A total of 362 and 242 proteins were identified in the hemocytes and plasma, respectively. Of these, 145 and 117 proteins exhibited significant differences in expression upon fluke infection in hemocytes and plasma, respectively. Among the proteins with significantly different expression patterns, we found proteins related to immune response (up-regulated in both hemocyte and plasma of infected snails) and proteins belonging to the structural and motor group (mostly down-regulated in hemocytes but up-regulated in plasma of infected snails). The proteins identified and quantified in this work will provide important information for the understanding of the factors involved in snail defense against O. viverrini and might facilitate the development of new strategies to control O. viverrini infection in endemic areas. [ABSTRACT FROM AUTHOR]

Liver fluke infection caused by Opisthorchis viverrini remains a major public health problem in many parts of Asia including Thailand, Lao PDR, Vietnam and Cambodia, where there is a strikingly high incidence of cholangiocarcinoma (CCA – hepatic cancer of the bile duct epithelium). Among other factors, uptake of O. viverrini excretory/secretory products ( Ov ES) by biliary epithelial cells has been postulated to be responsible for chronic inflammation and proliferation of cholangiocytes, but the mechanisms by which cells internalise O. viverrini excretory/secretory products are still unknown. Herein we incubated normal human cholangiocytes (H69), human cholangiocarcinoma cells (KKU-100, KKU-M156) and human colon cancer (Caco-2) cells with O. viverrini excretory/secretory products and analysed the effects of different endocytic inhibitors to address the mechanism of cellular uptake of ES proteins. Opisthorchis viverrini excretory/secretory products was internalised preferentially by liver cell lines, and most efficiently/rapidly by H69 cells. There was no evidence for trafficking of ES proteins to cholangiocyte organelles, and most of the fluorescence was detected in the cytoplasm. Pretreatment with clathrin inhibitors significantly reduced the uptake of O. viverrini excretory/secretory products, particularly by H69 cells. Opisthorchis viverrini excretory/secretory products induced proliferation of liver cells (H69 and CCA lines) but not intestinal (Caco-2) cells, and proliferation was blocked using inhibitors of the classical endocytic pathways (clathrin and caveolae). Opisthorchis viverrini excretory/secretory products drove IL6 secretion by H69 cells but not Caco-2 cells, and cytokine secretion was significantly reduced by endocytosis inhibitors. This the first known study to address the endocytosis of helminth ES proteins by host epithelial cells and sheds light on the pathways by which this parasite causes one of the most devastating forms of cancer in south-eastern Asia. [ABSTRACT FROM AUTHOR]

Determining of the success of a parasite's infectiveness in its snail host clearly depends on environmental conditions. Temperature, one of the most influential factors impinging on metabolism of cold-blooded animals, is believed to be an important factor in parasitic infection in snails. In order to elucidate the influence of temperature, sex and size of snails on infectivity of Opisthorchis viverrini to its first intermediate host, Bithynia siamensis goniomphalos , 960 snails were divided into 2 groups by sex. Each group was subdivided by their size into small and medium sub-groups. Each snail was fed with embryonated uterine-eggs of O. viverrini at different temperatures (16–37 °C, 3 °C intervals). Dissections were carried out 1, 7, 14, 28 and 56 days thereafter and detection of O. viverrini infection was undertaken by PCR using specific primers. Infection was strongly temperature-dependent, as temperature increases of 1 °C resulted in increased odds of infection 5.4% ( P < 0.01). A temperature of 34 °C gave the highest rate of infection of 44.14%. We also found that the odds of infection in small sized snails was 39.8% higher relative to medium sized snails ( P < 0.05). Relative to day 1, the decrease in the odds of infection was detected when the day post infection was longer ( P < 0.01). Proportion of infection in female was not different to male significantly. [ABSTRACT FROM AUTHOR]

Abstract: A cross sectional study on hepatobiliary abnormalities in opisthorchiasis was performed in 8936 males and females aged from 20 to 60years from 90 villages of Khon Kaen province, Northeast Thailand. All were stool-examined for Opisthorchis viverrini infection by standard quantitative formalin/ethyl acetate concentration technique. Of these, 3359 participants with stool egg positive underwent ultrasonography of the upper abdomen. The hepatobiliary abnormalities detected by ultrasound are described here. This study found a significantly higher frequency of advanced periductal fibrosis in persons with chronic opisthorchiasis (23.6%), particularly in males. Risks of the fibrosis included intensity of infection, and age younger than 30years. Height of left lobe of the liver, cross-section of the gallbladder dimensions post fatty meal, sludge, and, interestingly, intrahepatic duct stones were significantly associated with the advanced periductal fibrosis. Eleven suspected cholangiocarcinoma (CCA) cases were observed. This study emphasizes the current status of high O. viverrini infection rate and the existence of hepatobiliary abnormalities including suspected CCA in opisthorchiasis endemic areas of Thailand. [Copyright &y& Elsevier]