[Preliminary study on the effect of Echinococcus multilocaris on phenotypic transformations of glucose metabolism and polarization types in macrophages]

OBJECTIVE

To investigate the effects of Echinococcus multilocularis on the phenotypic transformations of glucose metabolism, polarization types and inflammatory responses in macrophages, so as to provide insights into elucidation of echinococcosis pathogenesis.

METHODS

Bone marrow cells were isolated from C57BL/6J mice at ages of 6 to 8 weeks, and induced into bone marrow-derived macrophages (BMDMs) with mouse macrophage colony-stimulating factor (M-CSF), which served as controls (BMDMs-M0). BMDMs-M0 induced M2 macrophages by interleukin-4 for 24 hours served as the IL-4 induction group, and BMDMs-M0 co-cultured with 2.4 ng/mL E. multilocularis cystic fluid (CF) served as the BMDM-CF co-culture group, while BMDMs-M0 co-cultured with E. multilocularis protoscolex (PSC) at a ratio of 500:1 served as the BMDM-PSC co-culture group. The types of polarization of BMDMs co-cultured with E. multilocularis CF and PSC were analyzed using flow cytometry, and the expression of macrophage markers, inflammatory factors, and glucose metabolism-related enzymes was quantified using fluorescent quantitative real-time PCR (qPCR) and Western blotting assays.

RESULTS

There were significant differences among the four groups in terms of Arginase-1 (Arg1) (F = 1 457.00, P < 0.000 1), macrophages-derived C-C motif chemokine 22 (Ccl22) (F = 22 203.00, P < 0.000 1), resistin-like α (Retnla) (F = 151.90, P < 0.000 1), inducible nitric oxide synthase (iNOS) (F = 107.80, P < 0.001), hexokinase (HK) (F = 9 389.00, P < 0.000 1), pyruvate kinase (PK) (F = 641.40, P < 0.001), phosphofructokinase 1 (PFK1) (F = 43.97, P < 0.01), glucokinase (GK) (F = 432.50, P < 0.000 1), pyruvate dehydrogenase kinases1 (PDK1) (F = 737.30, P < 0.000 1), lactic dehydrogenase (LDH) (F = 3 632.00, P < 0.000 1), glucose transporter 1 (GLUT1) (F = 532.40, P < 0.000 1), glyceraldehyde-3-phosphate dehydrogenase (GAPDH) (F = 460.00, P < 0.000 1), citrate synthase (CS) (F = 5 642.00, P < 0.01), glycogen synthase1 (GYS1) (F = 273.30, P < 0.000 1), IL-6 (F = 1 823.00, P < 0.000 1), IL-10 (F = 291.70, P < 0.000 1), IL-1β (F = 986.60, P < 0.000 1), and tumor necrosis factor (TNF)-α (F = 334.80, P < 0.000 1) and transforming growth factor (TGF)-β mRNA expression (F = 163.30, P < 0.001). The proportion of M2 macrophages was significantly higher than that of M1 macrophages in the BMDM-PSC co-culture group [(22.87% ±1.48%) vs. (1.70% ±0.17%); t = 24.61, P < 0.001], and the proportion of M2 macrophages was significantly higher than that of M1 macrophages in the BMDM-CF co-culture group [(20.07% ±0.64%) vs. (1.93% ±0.25%); t = 45.73, P < 0.001]. The mRNA expression of M2 macrophages markers Arg1, Ccl22 and Retnla was significantly higher in the BMDM-CF and BMDM-PSC co-culture groups than in the control group (all P values < 0.01), and no significant difference was seen in the mRNA expression of the M1 macrophage marker iNOS among the three groups (P > 0.05), while qPCR assay quantified higher mRNA expression of key glycolytic enzymes HK, PK and PFK, as well as inflammatory factors IL-10, IL-1β, TNF-α and TGF-β in the BMDM-CF and BMDM-PSC co-culture groups than in the control group (all P values < 0.01). Western blotting assay determined higher HK, PK and PFK protein expression in the BMDM-PSC co-culture group than in the control group (all P values < 0.05), and qPCR quantified higher GLUT1, GAPDH and IL-6 mRNA expression in the BMDM-CF co-culture group than in the control group (all P values < 0.05), while higher HK, PK and PFK protein and mRNA expression (all P values < 0.01), as well as lower IL-6 and TNF-α and higher TGF-β mRNA expression (both P values < 0.05) was detected in the IL-4 induction group than in the control group. Glycolytic stress test showed no significant difference in the extracellular acidification rate (ECAR) of mouse BMDM among the control group, IL-4 induction group and BMDM-PSC co-culture group (F = 124.4, P < 0.05), and a higher ECAR was seen in the BMDM-PSC co-culture group and a lower ECAR was found in the IL-4 induction group than in the control group (both P values < 0.05).

CONCLUSIONS

Treatment of E. multilocularis CF or PSC mainly causes polarization of BMDM into M2 macrophages, and phenotypic transformation of glucose metabolism into high-energy and high-glycolytic metabolism, and affects inflammatory responses in BMDM.

Comparative characterization of microRNA-71 of Echinococcus granulosus exosomes

Cystic echinococcosis (CE) is a global zoonotic disease caused by Echinococcus granulosus, posing a great threat to human and animal health. MiRNAs are small regulatory noncoding RNA involved in the pathogenesis of parasitic diseases, possibly via exosomes. Egr-miR-71 has been identified as one of the miRNAs in the blood of CE patients, but its secretory characteristics and functions remains unclear. Herein, we studied the secretory and biological activity of exosomal egr-miR-71 and its immunoregulatory functions in sheep peripheral blood mononuclear cells (PBMCs). Our results showed that egr-miR-71 was enriched in the exosome secreted by protoscoleces with biological activity. These egr-miR-71-containing exosomes were easily internalized and then induced the dysregulation of cytokines (IL-10 and TNF-α), nitric oxide (NO) and key components (CD14 and IRF5) in the LPS/TLR4 pathway in the coincubated sheep PBMCs. Similarly, egr-miR-71 overexpression also altered the immune functions but exhibited obvious differences in regulation of the cytokines and key components, preferably inhibiting proinflammatory cytokines (IL-1α, IL-1β and TNF-α). These results demonstrate that exosomal egr-miR-71 is bioactive and capacity of immunomodulation of PBMCs, potentially being involved in immune responses during E. granulosus infection.

Effect of sunitinib against Echinococcus multilocularis through inhibition of VEGFA-induced angiogenesis

BACKGROUND

Alveolar echinococcosis (AE) is a lethal zoonosis caused by the fox tapeworm Echinococcus multilocularis. The disease is difficult to treat, and an effective therapeutic drug is urgently needed. Echinococcus multilocularis-associated angiogenesis is required by the parasite for growth and metastasis; however, whether antiangiogenic therapy is effective for treating AE is unclear.

METHODS

The in vivo efficacy of sunitinib malate (SU11248) was evaluated in mice by secondary infection with E. multilocularis. Enzyme-linked immunosorbent assays (ELISAs) were used to evaluate treatment effects on serum IL-4 and vascular endothelial growth factor A (VEGFA) levels after SU11248 treatment. Gross morphological observations and immunohistochemical staining were used to evaluate the impact of SU11248 on angiogenesis and the expression of pro-angiogenic factors VEGFA and VEGF receptor 2 (VEGFR2) in the metacestode tissues. Furthermore, the anthelmintic effects of SU11248 were tested on E. multilocularis metacestodes in vitro. The effect of SU11248 on the expression of VEGFA, VEGFR2, and phosphorylated VEGFR2 (p-VEGFR2) in liver cells infected with protoscoleces in vitro was detected by western blotting, reverse transcription quantitative polymerase chain reaction (RT-qPCR), and enzyme-linked immunosorbent assay (ELISA). The influence of SU11248 on endothelial progenitor cell (EPC) proliferation and migration was determined using CCK8 and transwell assays.

RESULTS

In vivo, SU11248 treatment markedly reduced neovascular lesion formation and substantially inhibited E. multilocularis metacestode growth in mice. Further, it exhibited high anti-hydatid activity as efficiently as albendazole (ABZ), and the treatment resulted in reduced protoscolex development. In addition, VEGFA, VEGFR2, and p-VEGFR2 expression was significantly decreased in the metacestode tissues after SU11248 treatment. However, no effect of SU11248 on serum IL-4 levels was observed. In vitro, SU11248 exhibited some anthelmintic effects and damaged the cellular structure in the germinal layer of metacestodes at concentrations below those generally considered acceptable for treatment (0.12-0.5 μM). Western blotting, RT-qPCR, and ELISA showed that in co-cultured systems, only p-VEGFR2 levels tended to decrease with increasing SU11248 concentrations. Furthermore, SU11248 was less toxic to Reuber rat hepatoma (RH) cells and metacestodes than to EPCs, and 0.1 μM SU11248 completely inhibited EPC migration to the supernatants of liver cell and protoscolex co-cultures.

CONCLUSIONS

SU11248 is a potential candidate drug for the treatment of AE, which predominantly inhibits parasite-induced angiogenesis. Host-targeted anti-angiogenesis treatment strategies constitute a new avenue for the treatment of AE.

Report of a two-headed protoscolex of Echinococcus granulosus revealed by phase contrast microscopy in Shiraz, Iran

Echinococcus granulosus sensu lato can produce cystic echinococcosis (CE)/hydatidosis in different hosts. Each CE cyst can produce numerous protoscoleces by its germinal layer in two forms: evaginated and invaginated. Usually, each protoscolex has one head consisting of a rostellum with two rows of hooks and four suckers. During a study of protoscolicidal agents on sheep Echinococcus granulosus protoscoleces, and investigations on their microscopic changes using Phase contrast microscopy, we observed a case of two- headed evaginated protoscolex. Two heads were attached to a unique bigger size of protoscolex body. Morphological observations showed its dimension around two times of usual protoscolex. There was no space between the bodies, hence one fused body was observed which was clearly shown by Phase contrast microscopy. Each head possessed two rows of hooks. Using micrometry all parts of the two-headed protoscolex, especially hooks were measured and photographed showing all aspects of its morphology including tegument, hooks, and two heads. Specific parts of two-headed protoscolex including suckers, hooks, also calcareous corpuscles were measured. The measurements on the two-headed protoscolex showed that the small hook blade length (SBL) and large hook blade length (LBL) were almost langer than one head protoscolex. A total of 120 calcareous corpuscles in two headed-protoscolex is much higher than one head protoscoleces.

Establishment of a secondary infection laboratory model of Echinococcus shiquicus metacestode using BALB/c mice and Mongolian jirds (Meriones unguiculatus)

Echinococcus shiquicus is peculiar to the Qinghai–Tibet plateau of China. Research on this parasite has mainly focused on epidemiological surveys and life cycle studies. So far, limited laboratory studies have been reported. Here, experimental infection of E. shiquicus metacestode in BALB/c mice and Mongolian jirds (Meriones unguiculatus) was carried out to establish alternative laboratory animal models. Intraperitoneal inoculation of metacestode material containing protoscoleces (PSCs) obtained from infected plateau pikas were conducted on BALB/c mice. Furthermore, metacestode material without PSCs deriving from infected BALB/c mice was intraperitoneally inoculated to Mongolian jirds. Experimental animals were dissected for macroscopic and histopathological examination. The growth of cysts in BALB/c mice was infiltrative, and they invaded the murine entire body. Most of the metacestode cysts were multicystic, but a few were unilocular. The cysts contained sterile vesicles, which had no PSCs. The metacestode materials were able to successfully infect new mice. In the jirds model, E. shiquicus cysts were typically formed freely in the peritoneal cavity; the majority of these cysts were free while a small portion adhered loosely to nearby organs. The proportion of fertile cysts was high, and contained many PSCs. The PSCs produced in Mongolian jirds also successfully infected new ones, which confirms that jirds can serve as an alternative experimental intermediate host. In conclusion, a laboratory animal infection was successfully established for E. shiquicus using BALB/c mice and Mongolian jirds. These results provide new models for the in-depth study of Echinococcus metacestode survival strategy, host interactions and immune escape mechanism.

Bioinformatics analysis and experimental verification of Notch signalling pathway-related miRNA-mRNA subnetwork in extracellular vesicles during Echinococcus granulosus encystation

Background

Encystation of the protoscoleces (PSCs) of Echinococcus granulosus is the main cause of secondary hydatid dissemination in the intermediate host. Extracellular vesicles (EVs) can transfer miRNAs into parasite cells to regulate mRNA expression. However, loading of developmental pathway-related miRNAs, such as those related to the Notch signalling pathway in EVs is unclear. Thus, we screened the miRNA-mRNA subnetwork involved in the Notch pathway during E. granulosus encystation in vitro and assessed changes in expression in the parasite and EVs.

Methods

mRNAs and miRNAs differentially expressed (DE) between PSCs and microcysts (MCs) were screened using high-throughput sequencing. DE mRNAs obtained from transcriptome analysis were intersected with mRNAs predicted to be targets of the conserved DE miRNAs of a small RNA library. DE miRNA functions were analysed using public databases, and a miRNA–mRNA subnetwork related to the Notch pathway was established. Notch pathway-related mRNA and miRNA expression of worms and EVs at different times was verified.

Results

In total, 1445 DE mRNAs between MCs and PSCs were screened after the intersection between 1586 DE mRNAs from the transcriptome and 9439 target mRNAs predicted using 39 DE miRNAs from the small RNA library. The DE mRNAs were clustered into 94 metabolic pathways, including the Notch pathway. Five DE miRNAs, including the most significantly expressed new DE miRNA, egr-new-mir0694-3p, corresponding to four target mRNAs (EgrG_000892700, EgrG_001029400, EgrG_001081400 and EgrG_000465800) were all enriched in the Notch pathway. The expression of the above mRNAs and miRNAs was consistent with the results of high-throughput sequencing, and the expression of each miRNA in EVs was verified. Annotated as ADAM17/TACE in the Notch pathway, EgrG_000892700 was down-regulated during PSC encystation. egr-miR-4989-3p and egr-miR-277a-3p expression in EVs after encystation was nearly five times that in EVs before encystation, which might regulate the expression of EgrG_000892700.

Conclusions

Five miRNAs corresponding to four target mRNAs may be involved in regulating the Notch pathway during the PSC encystation. EVs may regulate the expression of EgrG_000892700 in PSCs because of continuous targeting of egr-miR-4989-3p and egr-miR-277a-3p and participate in the regulation the Notch pathway. The study might expand new ideas for blocking the secondary infection of E. granulosus PSCs via EVs miRNAs.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-022-05391-8.

In vitro evaluation of albendazole-loaded nanostructured lipid carriers on Echinococcus granulosus microcysts and their prophylactic efficacy on experimental secondary hydatidosis

To enhance the therapeutic effects of albendazole (ABZ) on Echinococcus granulosus protoscoleces and metacestodes, ABZ-loaded nanostructured lipid carriers (ABZ-NLCs) are prepared by the hot high-speed homogenization method. Protoscoleces and microcysts were treated in vitro with free ABZ and ABZ-NLCs (concentrations of 1, 5, and 10 μg/ml), and the corresponding effects were monitored by methylene blue exclusion test and scanning and transmission electron microscopy. Chemoprophylactic treatment was performed on Balb/C mice 1 day before intraperitoneal injection of viable protoscoleces. The drugs were administered daily by intragastric inoculation for a period of 30 days. The prophylactic efficacy was assessed based on the number and weight of cysts developed in treated mice. The ultrastructural alterations in cysts were examined by transmission electron microscopy. After 18 days, all the protoscoleces incubated with 10 μg/ml ABZ-NLCs were killed, while 51.25 ± 4.03% of the protoscoleces incubated with 10 μg/ml free ABZ were still viable. Microcysts treated with ABZ-NLCs underwent degenerative alterations in a shorter time than when free ABZ was applied. The mean weight of the cysts recovered from mice of ABZ-NLCs group was significantly lower than that of the free ABZ group (P < 0.05), yielding prophylactic efficacy of 92.45% and 38.53%, respectively. The cysts treated with ABZ-NLCs showed marked ultrastructural changes in the germinal layer. This study demonstrated that both in vitro and in vivo treatments with ABZ-NLCs are significantly more efficient than treatment with free ABZ against E. granulosus protoscoleces, metacestodes, and prevention of cyst development in mice.

Ultrastructural characterization of the tegument in protoscoleces of Echinococcus ortleppi

Cystic echinococcosis is a globally distributed zoonosis caused by cestodes of the Echinococcus granulosus sensu lato (s.l.) complex, with Echinococcus ortleppi mainly involved in cattle infection. Protoscoleces show high developmental plasticity, being able to differentiate into either adult worms or metacestodes within definitive or intermediate hosts, respectively. Their outermost cellular layer is called the tegument, which is important in determining the infection outcome through its immunomodulating activities. Herein, we report an in-depth characterization of the tegument of E. ortleppi protoscoleces performed through a combination of scanning and transmission electron microscopy techniques. Using electron tomography, a three-dimensional reconstruction of the tegumental cellular territories was obtained, revealing a novel structure termed the 'tegumental vesicular body' (TVB). Vesicle-like structures, possibly involved in endocytic/exocytic routes, were found within the TVB as well as in the parasite glycocalyx, distal cytoplasm and close inner structures. Furthermore, parasite antigens (GST-1 and AgB) were unevenly localised within tegumental structures, with both being detected in vesicles found within the TBV. Finally, the presence of host (bovine) IgG was also assessed, suggesting a possible endocytic route in protoscoleces. Our data forms the basis for a better understanding of E. ortleppi and E. granulosus s.l. structural biology.

Scolicidal effects of Cassia fistula and Urtica dioica extracts on protoscoleces of hydatid cysts

Echinococcosis is among the most underestimated parasitic diseases that have universal distribution. The primary treatment is surgery. Hence, the development of new and more effective scolicidal agents with lower side effects is crucial. This study evaluated the therapeutic effects of Urtica dioica and Cassia fistula extracts as a scolicidal herbal drug in vitro. Suspension of protoscoleces was obtained from the infected livers of sheep in Khorramabad, Iran. Hydro-alcoholic solution was extracted from the leaves and stems of Urtica dioica and the fruit of Cassia fistula. Echinococcus granulosus protoscoleces were treated with the essential oils at concentrations of 10, 25, 50, and 100 mg/mL for 10, 20, 30, and 60 min and their viability was evaluated by the eosin staining test. The extract of Urtica dioica at a concentration of 100 mg/mL killed 90.51% of protoscoleces after 60 min. Cassia fistula also killed 67.74% of protoscoleces after 60 min. This study obtained satisfactory results. Urtica dioica and Cassia fistula extracts are promising protoscolicides and can be used in the treatment of hydatid cysts and pre-surgically to prevent secondary infections.

In vitro evaluation on the scolicidal effect of Myrtus communis L. and Tripleurospermum disciforme L. methanolic extracts

Hydatid disease, a zoonotic disease, is still endemic in many developing countries that is caused by the metacestode of Echinococcus (E.) granulosus. Surgical management is one of the best choices for the treatment of the hydatidosis and using effective scolicidal agents during hydatid surgery is essential to prevent the secondary infection. The aim of the present in vitro study was to evaluate the scolicidal effect of the methanolic extract of Myrtus communis and Tripleurospermum disciforme against protoscoleces of hydatid cyst. Protoscoleces of E. granulosus were aspirated aseptically from infected livers. Various concentrations of M. communis and T. disciforme extracts at different exposure times were examined for their scolicidal activity. Normal saline and silver nitrate were used as negative and positive groups, correspondingly. The viability of protoscoleces was evaluated by 0.1% eosin. The result of the current study indicated that the highest scolicidal effect (100%) of M. communis was obtained at 100 and 50 mg/ml concentrations and LC50 in 10, 20 and 30 min were 11.64 mg/ml, 7.62 mg/ml, and 6.47 mg/ml respectively. The scolicidal activity of T. disciforme was negligible even at high concentration. The findings have shown that the scolicidal activity of M. communis against echinococcosis protoscoleces was strong, while the T. disciforme extract showed fewer effects. However, further studies are required for identification of the active ingredients in the extract and its safety on cells in effective concentrations.

Efficiency of flubendazole-loaded mPEG-PCL nanoparticles: A promising formulation against the protoscoleces and cysts of Echinococcus granulosus

None of the existing drugs can effectively treat the human cystic echinococcosis. This study aimed to improve the efficacy of flubendazole (FLBZ) against the protoscoleces and cysts of Echinococcus granulosus by preparing polymeric FLBZ-loaded methoxy polyethylene glycol-polycaprolactone (mPEG-PCL) nanoparticles. The protoscoleces and microcysts were treated with FLBZ-loaded mPEG-PCL nanoparticles (FLBZ-loaded nanoparticles) and free FLBZ at the final concentrations of 1, 5, and 10 μg/mL for 27 and 14 days, respectively. The chemoprophylactic efficacy of the drugs was evaluated in experimentally infected mice. The nanoparticles were stable for 1 month, with an average size of 101.41 ± 5.14 nm and a zeta potential of -19.13 ± 2.56 mV. The drug-loading and entrapment efficiency of the FLBZ-loaded nanoparticles were calculated to be 3.08 ± 0.15% and 89.16 ± 2.93%, respectively. The incubation of the protoscoleces with the 10 μg/mL nano-formulation for 15 days resulted in 100% mortality, while after incubation with the 10 μg/mL free FLBZ, the viability rate of the protoscoleces was only 44.0% ± 5.22%. Destruction of the microcysts was observed after 7 days' exposure to the FLBZ-loaded nanoparticles at a concentration of 10 μg/mL. The in vivo challenge showed a significant reduction in the weight and number of the cysts (P <  0.05) in the mice treated with the FLBZ-loaded nanoparticles, yielding efficacy rates of 94.64% and 70.21%, correspondingly. Transmission electron microscopy revealed extensive ultrastructural damage to the cysts treated with the FLBZ-loaded nanoparticles. The results indicated that the FLBZ-loaded nanoparticles were more effective than the free FLBZ against the protoscoleces and cysts of E. granulosus both in vitro and in vivo.

Analysis for genetic loci controlling protoscolex development in the Echinococcus multilocularis infection using congenic mice

The resistance/susceptibility to Echinococcus multilocularis infection in mice is genetically controlled. However, genetic factors responsible for these differences remain unknown. Our previous study in genetic linkage analysis has revealed that there is a significant quantitative trait locus (QTL) for the establishment of cyst (Emcys1), and a highly significant QTL for the development of protoscolex of E. multilocularis larvae (Empsc1), on mouse chromosomes 6 and 1, respectively. The current study aimed to confirm these QTLs and narrow down the critical genetic region that controls resistance/susceptibility to E. multilocularis infection by establishing congenic and subcongenic lines from C57BL/6 (B6) and DBA/2 (D2) mice. For protoscolex development phenotype, two congenic lines, B6.D2-Empsc1 and D2.B6-Empsc1 were developed, where responsible QTL, Empsc1 was introgressed from D2 into B6 background and vice versa. For cyst establishment phenotype, two congenic lines, B6.D2-Emcys1 and D2.B6-Emcys1 were developed, where responsible QTL, Emcys1 was introgressed from D2 into B6 background and vice versa. Because there was no significant difference in cyst establishment between B6.D2-Emcys1 and D2.B6-Emcys1 mice after challenge with E. multilocularis, it is suggested that the Emcys1 does not solely control the cyst establishment in mouse liver. However, infection experiments with B6.D2-Empsc1 and D2.B6-Empsc1 mice showed a significant difference in protoscolex development in the cyst. It confirms that the Empsc1 controls phenotype of the protoscolex development in the cyst. Subsequently, two subcongenic lines, B6.D2-Empsc1.1 and B6.D2-Empsc1.2 from B6.D2-Emcys1 and one subcongenic line, D2.B6-Empsc1.1 from D2.B6-Empsc1 were developed to narrow down the critical region responsible for protoscolex development. From the results of infection experiments with E. multilocularis in these subcongenic mice, it is concluded that a gene responsible for protoscolex development is located between D1Mit290 (68.1 cM) and D1Mit511 (97.3 cM).

Identification of emu-TegP11, an EF-hand domain-containing tegumental protein of Echinococcus multilocularis

Tegumental proteins (TegPs) are a group of proteins that coat on the surface of worms, mainly being involved in ion uptake and immune evasion. Echinococcus species have many TegPs, but none of them have been characterized and their role remains unclear. The genome-wide analysis revealed that there were at least 14 tegp genes (tegp1 - 14) in Echinococcus species, the majority of which were found to contain an EF-hand domain or a dynein light chain-like domain or both. Despite low identity, all TegP11 proteins from 25 flatworms were conserved in structure. Echinococcus multilocularis TegP11 (emu-TegP11) was verified to be secreted by extracellular vesicles and to be localized in different spatiotemporal patterns in protoscoleces. Moreover, emu-TegP11 was also shown to have weak or no Ca²⁺-binding capacity. In treated macrophages, emu-TegP11 interfered with the small RNA-induced silencing pathway via inducing ectopic expression of some key component genes. Additionally, emu-TegP11 remarkably promoted NO secretion possibly by upregulation of inos gene expression (p < 0.05). It was further shown that emu-TegP11 acted as a suppressor of inflammation, with il-12B and il-1β being significantly down-regulated (p < 0.01), and il-10 and il-4 being significantly upregulated (p < 0.05). The study demonstrates a regulatory role of emu-TegP11, likely acting as a immunomodulator to be involved in regulation of host immune system during Echinococcus infection.

Improved experimental model of hepatic cystic hydatid disease resembling natural infection route with stable growing dynamics and immune reaction

AIM

To investigate a safer way to set up the disease model of cystic echinococcosis without contamination risk and develop a novel experimental murine model of hepatic cystic echinococcosis.

METHODS

C57B/6 mice were injected with human protoscolices of three different concentrations via the portal vein. The mice were followed for 10 mo by ultrasound, gross anatomy, and pathological and immunological examinations. The protoscolex migration in the portal vein, hydatid cyst growth, host immune reaction, and hepatic histopathology were examined periodically.

RESULTS

The infection rates in the mice in the high, medium, and low concentration groups were 90%, 100%, and 63.6%, respectively. The protoscolices migrated in the portal vein with blood flow, settled in the liver, and developed into orthotopic hepatic hydatid cysts, resembling the natural infection route and course.

CONCLUSION

We have established an improved experimental model of hepatic cystic echinococcosis with low biohazard risk but stable growing dynamics and immune reaction. It is especially useful for new anti-parasite medication trials against hydatid disease.

Evaluating the effect of Myrtus communis on programmed cell death in hydatid cyst protoscolices

OBJECTIVE

To evaluate the possible involvement of programmed cell death strategy in hydatid cyst protoscolices following treatment with Myrtus communis (M. communis) as an herbal medicine.

METHODS

Protoscolices were aseptically collected from sheep liver hydatid cysts. Evaluating the effect of M. communis extract on programmed cell death and increased activity of caspases 3, 8, and 9 in hydatid cyst protoscolices was conducted by treating the protoscolices with different concentration (5, 50, and 100 mg/mL) of M. communis extract at 37 °C and 5% CO₂ for 4 h by using the Bradford test and ELISA commercial kits.

RESULTS

The extract of M. communis at all concentrations led to initiation of programmed cell death in protoscolices and this effect, was only significant at 50 and 100 mg/mL concentrations, compared to the negative control (P < 0.05). Also, the activity of caspases 3, 8, and 9 in hydatid cyst protoscolices, was shown that the extract at all 3 concentrations could only increase the activity of caspases 3 and 9. Moreover, a significant increase in the activity of caspase 3 was only observed at concentrations 50 and 100 mg/mL by 37.00% and 66.19% while a significant increase in the activity of caspase 9 at the same concentrations was observed by 20.89% and 63.67%, respectively (P < 0.05).

CONCLUSIONS

The extract of M. communis at different concentrations could increase the activity of caspases 3 and 9 and caused programmed cell death in hydatid cyst protoscolices however, this effect was significant at high concentrations of the extract.

Suppression of nemo-like kinase by miR-71 in Echinococcus multilocularis

Echinococcus multilocularis metacestodes are a causative pathogen for alveolar echinococcosis in human beings, and have been found to express miRNAs including emu-miR-71. miR-71 is evolutionarily conserved and highly expressed across platyhelminths, but little is known about its role. Here it was shown that emu-miR-71 was differentially expressed in protoscoleces and was unlikely to be expressed in neoblasts. The results of the luciferase assay indicated that emu-miR-71 was able to bind in vitro to the 3'-UTR of emu-nlk, encoding a key regulator of cell division, causing significant downregulation of luciferase activity (p < 0.01) compared to the negative control and the construct with mutations in the binding site. Consistent with the decreased luciferase activity, transfection of emu-miR-71 mimics into protoscoleces notably repressed emu-NLK (p < 0.05). These results demonstrate the suppression of emu-nlk by emu-miR-71, potentially involved in the protoscolex development.

Nanosecond pulsed electric field (nsPEF) disrupts the structure and metabolism of human Echinococcus granulosus protoscolex in vitro with a dose effect

The number of interventional treatments for hepatic cystic echinococcosis is increasing, but the chemicals or high temperatures used in these methodologies cause biliary complications, thus limiting their clinical applications. This experimental study aimed to apply a novel, non-thermal, non-chemical ablation method termed nanosecond pulsed electric field (nsPEF) for the treatment of human hepatic cystic echinococcosis. The nsPEF treatment parameters against protoscolices from human hepatic cystic echinococcosis were optimized in vitro. The efficacy and mechanism of nsPEF treatment were also investigated. Fresh protoscolices were isolated from human hepatic cystic echinococcosis and were exposed to 300 ns of nsPEF with different field strengths (0, 7, 14, 21, and 29 kV/cm) and pulse numbers (50 and 100 pulses). Then, the viability of the nsPEF-treated protoscolices was evaluated in vitro. Morphological and ultra-structural changes were visualized with H&E staining and scanning electron microscopy. The membrane enzyme activity of alkaline phosphatase (AP) and gamma-glutamyl-transpeptidase (GGT) was measured. nsPEF caused dose-dependent protoscolex death. One-hundred pulses of nsPEF at 21 kV/cm or higher caused a significant increase in the death rate of protoscolices. nsPEF induced significant lethal damage with 50 pulses at 21 or 29 kV/cm and with 100 pulses at 14, 21, or 29 kV/cm, accompanied by morphological destruction and increased levels of AP and GGT membrane enzymes. Thus, nsPEF induced dose-dependent protoscolex mortality and caused destruction of protoscolices and increased membrane enzymes. The mechanism may involve direct damage to the membrane structures of the protoscolices, promoting enzyme exhaustion and disruption of metabolism.

Proteomics analysis of Echinococcus granulosus protoscolex stage

Echinococcus granulosus protoscolex proteins were separated using two-dimensional electrophoresis and then identified using mass spectrometry; we identified 61 proteins, 28 which are newly described of which 4 could be involved in hydatid cyst fertility molecular mechanisms.

[Parasitological study of 78 cases of human cystic echinococcosis collected between 2005 to 2012 in Mustapha hospital center of Algiers]

AIM

The aim of this work is to know the fertility rate of the metacestodes resulting from patients suffering from hydatidosis, the one of protoscoleces's viability and by comparing the results obtained with those found elsewhere. It reports, also, the epidemiological, clinical and diagnostically aspects of the studied patients.

MATERIALS AND METHODS

This study has carried on 78 hydatics samples resulting from 78 patients collected between 2005 and 2012 at the laboratory of parasitology of the Mustapha hospital center of Algiers. A questionnaire on the epidemiological context (contact with an animal-host of the cycle, place of residence, presence of family cases reached of hydatidosis and knowledge on the hydatic disease) concerned 69 patients. For each sample, a direct microscopic examination is made with or without vital staining. The presence of protoscoleces made qualified the fertile cyst. Those visualized moving or resistant to eosin at 0.2% are considered viables. Indirect diagnosis is based on the techniques: passive hemagglutination, electrophoresis, Elisa IgG Echinococcus granulosus and immunoblotting IgG "Echinococcus". Molecular analysis is based on PCR and sequencing the partials fragments of two mitochondrial genes with the primers COX1 and ND1.

RESULTS

The results obtained show that the surgical frequency of hydatidosis is significant at the young adult and at the child. The epidemiological context associated at the disease is the conjointly presence of a dog and herbivores. The fertility rate of human hydatid cysts is 88.4% and the ones of viability of the protoscoleces is 74.5%. In this series, the serology shows global positivity at 70%. The molecular characterization of five samples identify the species: E. granulosus ss.

CONCLUSION

Finally, the viability and fertility rates found here are raised. Sometimes viables protoscoleses are found after use of scolicidal solution. In front of these results, the parasitical treatment is more than necessary in order to minimize the risk of occurred of secondary echinococcosis or the relapses postoperatives.

Serodiagnosis of human hydatidosis with an ELISA developed based on antigens derived from sheep hydatid cysts and comparison with a commercial human ELISA kit

OBJECTIVE

To explore the serodiagnosis of hydatid cyst in human using different antigens of sheep (hydatid fluid, Somatic and Excretory/secretory antigens of protoscolex) by ELISA and compares this result with commercial human ELISA kit.

METHODS

One hundred blood samples from patients with history of severe abdominal pain and eosinophilia were obtained. Ten serum samples were obtained from surgically and pathologically confirmed cystic echinococcosis patients from Mashhad university hospital as positive control and 5 serum samples from infant under one year old as negative control. Blood samples were centrifuged at 3 000μg at 20 °C for 15 min and sera were stored at -20 °C. First, these samples were tested for the presence of antibody by commercial human ELISA. Then, ELISA was developed on microplates coated with hydatid fluid, Somatic and Excretory/secretory antigens of protoscolex of sheep.

RESULTS

The results of this study as analyzed by Kappa test showed that, hydatid fluid antigen could be used as a precise source of detection in indirect ELISA test.

CONCLUSIONS

Hydatid fluid in comparison with Excretory-secretory and somatic antigens showed more compatibility agreement in kappa test which can be used for further studies in development of any ELISA test for diagnosis of human hydatidosis.