Hemozoin is the pigment produced by some blood-feeding parasites. It demonstrates high diagnostic and therapeutic potential. In this work the formation of co-called hemozoin “knobs” – the bile duct ectasia filled up by hemozoin pigment - in Opisthorhis felineus infected hamster liver has been observed. The O. felineus infected liver was examined by histological analysis and magnetic resonance imaging (MRI). The pigment hemozoin was identified by Fourier transform infrared spectroscopy and high resolution electrospray ionization mass spectrometry analysis. Hemozoin crystals were characterised by high resolution transmission electron microscopy. Hemozoin crystals produced by O. felineus have average length 403 nm and the length-to-width ratio equals 2.0. The regurgitation of hemozoin from parasitic fluke during infection leads to formation of bile duct ectasia. The active release of hemozoin from O. felineus during in vitro incubation has also been evidenced. It has been shown that the hemozoin knobs can be detected by magnetic resonance imaging. In the paper for the first time the characterisation of hemozoin pigment extracted from liver fluke O. felineus has been conducted. The role of hemozoin in the modification of immune response by opisthorchiasis is assumed.

Opisthorchiasis is a hepatobiliary disease caused by flukes of the trematode family Opisthorchiidae. Opisthorchiasis can lead to severe hepatobiliary morbidity and is classified as a carcinogenic agent. Here we investigate the time-resolved metabolic response to Opisthorchis felineus infection in an animal model. Thirty golden hamsters were divided in three groups: severe infection (50 metacercariae/hamster), mild infection (15 metacercariae/hamster) and uninfected (vehicle-PBS) groups. Each group consisted of equal number of male and female animals. Plasma samples were collected one day before the infection and then every two weeks up to week 22 after infection. The samples were subjected to ¹H Nuclear Magnetic Resonance (NMR) spectroscopy and multivariate statistical modelling. The time-resolved study of the metabolic response to Opisthorchis infection in plasma in the main lines agrees with our previous report on urine data. The response reaches its peak around the 4th week of infection and stabilizes after the 10th week. Yet, unlike the urinary data there is no strong effect of the gender in the data and the intensity of infection is presented in the first two principal components of the PCA model. The main trends of the metabolic response to the infection in blood plasma are the transient depletion of essential amino acids and an increase in lipoprotein and cholesterol concentrations. The time resolved metabolic signature of Opisthorchis infection in the hamster’s plasma shows a coherent shift in amino acids and lipid metabolism. Our work provides insight into the metabolic basis of the host response on the helminth infection. Opisthorchiasis is a parasitic infection caused by liver flukes of the Opisthorchiidae family. The liver fluke infection triggers development of hepatobiliary pathologies such as chronic forms of cholecystitis, cholangitis, pancreatitis, and cholelithiasis and increases the risk of intrahepatic cholangiocarcinoma. This manuscript is the second part of our outgoing project dedicated to a comprehensive description of the metabolic response to opisthorchiasis (more specifically Opisthorchis felineus) in an animal model. We show that the metabolic response in blood plasma is unfolding according to the same scenario as in urine, reaching its peak at the 4th week and stabilizing after the 10th week post-infection. Yet, unlike the response described in urine, the observed metabolic response in plasma is less gender specific. Moreover, the biochemical basis of the detected response in blood plasma is restricted to the remodeling of the lipid metabolism and the transient depletion of essential amino acids. Together with our first manuscript this report forms the first systematic description of the metabolic response on opisthorchiasis in an animal model using two easily accessible biofluids. Thus, this contribution provides novel results and fills an information gap still existing in the analytically driven characterization of the “Siberian liver fluke”, Opisthorchis felineus.

Opisthorchiasis is a parasitic infection caused by the liver flukes of the Opisthorchiidae family. Both experimental and epidemiological data strongly support a role of these parasites in the etiology of the hepatobiliary pathologies and an increased risk of intrahepatic cholangiocarcinoma. Understanding a functional link between the infection and hepatobiliary pathologies requires a detailed description a host-parasite interaction on different levels of biological regulation including the metabolic response on the infection. The last one, however, remains practically undocumented. Here we are describing a host response on Opisthorchiidae infection using a metabolomics approach and present the first exploratory metabolomics study of an experimental model of O. felineus infection. We conducted a Nuclear Magnetic Resonance (NMR) based longitudinal metabolomics study involving a cohort of 30 animals with two degrees of infection and a control group. An exploratory analysis shows that the most noticeable trend (30% of total variance) in the data was related to the gender differences. Therefore further analysis was done of each gender group separately applying a multivariate extension of the ANOVA—ASCA (ANOVA simultaneous component analysis). We show that in the males the infection specific time trends are present in the main component (43.5% variance), while in the females it is presented only in the second component and covers 24% of the variance. We have selected and annotated 24 metabolites associated with the observed effects and provided a physiological interpretation of the findings. The first exploratory metabolomics study an experimental model of O. felineus infection is presented. Our data show that at early stage of infection a response of an organism unfolds in a gender specific manner. Also main physiological mechanisms affected appear rather nonspecific (a status of the metabolic stress) the data provides a set of the hypothesis for a search of the more specific metabolic markers of the Opisthorchiidae infection. Opisthorchiasis is a parasitic infection caused by the liver flukes of the Opisthorchiidae family (Trematoda; Platyhelminthes). The liver fluke infections trigger development of the hepatobiliary pathologies such as chronic forms of cholecystitis, cholangitis, pancreatitis, and cholelithiasis. However, the most threatening effect of the Opisthorchiidae infection is an increased risk of intrahepatic cholangiocarcinoma. With this work we are getting an insight into a host response on Opisthorchiidae infection using a metabolomics approach. Metabolomics is a post-genomic discipline studying the metabolome. The dynamic character of the metabolome, its ability to change in response to the external stimuli makes it an optimal “readout” for exploratory studies aiming for the description of the systemic responses of an organism. Using this approach we demonstrate that that early response to the O. felineus infection unfolds in a gender-dependent manner. Moreover, with this first exploratory analysis of the metabolic response to O. felineus infection in an animal model we present a subset of the metabolites changing during the early phase of the infection and offer a possible physiological interpretation.

Aim. To examine the pattern of morphological changes, RNA quality number, and gene expression in mouse tissues sampled at autopsy under controlled experimental conditions.Materials and methods. Balb/c mice were euthanized and subsequently subjected to necropsy at 0, 3, 12, 24, 48, and 72 hours of the postmortem period. During the first three hours following euthanasia, the mice were maintained at room temperature, after which they were transferred to a refrigerator (4 º С). Total RNA was extracted from tissue samples taken from the kidney, liver, and brain; the integrity of the RNA samples was assessed by capillary electrophoresis, and the RNA quality number (RQN) was calculated. The expression levels of Actb, Epas1, and Rps18 housekeeping genes were evaluated by real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR) with original primers and probes using the TaqMan assay. The histologic examination was performed according to standard techniques.Results. Degradation of RNA extracted from mouse kidney tissues appeared to be greater than that of RNA taken from the liver. In the meantime, a negative linear correlation was observed between RQN and the duration of the postmortem interval for liver and kidney samples. In contrast, no significant changes in the RQN score were observed for brain RNA samples at any of the time points. The expression of the Epas1 and Rps18 genes was significantly decreased in mouse kidney and liver tissues. However, the level of Epas1 and Rps18 gene expression in the brain remained stable at all time points and did not exhibit a significant decrease at 72 hours after euthanasia. No obvious morphological changes were detected by the histologic examination, which does not exclude the presence of ultrastructural pathological changes.Conclusion. RQN in autopsy tissues serves as a crucial predictor of sample quality for molecular biology studies, including gene expression analysis.