Echinococcus multilocularis drives the polarization of macrophages by regulating the RhoA-MAPK signaling pathway and thus affects liver fibrosis.

Echinococcus multilocularis is a small parasite that causes alveolar echinococcosis. It primarily induces liver disorder, such as liver fibrosis and even liver cancer, which severely endangers human lives. This study aims to explore the efficacy of Echinococcus multilocularis soluble antigen in preventing and alleviating alveolar echinococcosis-induced liver fibrosis and determine the underlying mechanism. We first identified the optimal dose and time of Echinococcus multilocularis soluble antigen. The protein levels of key genes in the RhoA-MAPK signaling pathway were remarkably upregulated in RAW264.7 and Ana-1 cells induced with 80 µg/mL Echinococcus multilocularis soluble antigen for 8 h. Interestingly, the upregulated expression levels were remarkably reversed by the RhoA, JNK, ERK, or p38 inhibitor, confirming the significance of the RhoA-MAPK signaling pathway. In addition, the relative contents of M2 polarization markers IL-10 and Arg-1 in macrophages induced with 80 µg/mL Echinococcus multilocularis soluble antigen for 8 h increased, whereas those of M1 polarization markers IL-12 and NOS-2 decreased. Mouse hepatic stellate cells were the key components of the hepatocellular carcinoma tumor microenvironment. Hepatic stellate cells were activated by Echinococcus multilocularis soluble antigen and transformed into the morphology of myofibroblasts in response to liver disorders. By detecting the marker of myofibroblast formation, RhoA inhibitor remarkably reduced the positive expression of α-SMA in mouse hepatic stellate cells induced with Echinococcus multilocularis soluble antigen. Therefore, Echinococcus multilocularis soluble antigen remarkably activated the RhoA-MAPK pathways in macrophages, further inducing the polarization of macrophages and ultimately causing liver fibrosis. HYPOTHESIS: We hypothesize that infection with Echinococcus multilocularis activates the RhoA-MAPK signaling pathway and subsequently induces macrophage polarization to promote hepatic stellate cells activation leading to liver fibrosis. AIMS: To investigate the mechanism by which soluble antigen of Echinococcus multilocularis affects liver fibrosis through the RhoA-MAPK pathway driving polarization of macrophages. GOALS: To identify new pathways of intervention and drug targets for the regulation of macrophage polarity phenotype switching and the attenuation or inhibition of the development and treatment of liver fibrosis caused by Echinococcus multilocularis infection.

Mechanism of Fibrosis Induced by Echinococcus spp.

Infection with Echinococcus spp. causes fibrosis in various vital organs, including the liver and lungs. Hepatic fibrosis is a pathological feature of Echinococcus infection that destroys normal liver tissue, leading to jaundice, cholecystitis, portal hypertension, etc. Severe Echinococcus multilocularis infections lead to liver failure and hepatic encephalopathy. The formation of peripheral fiberboards around the metacestode is a major reason as to why antiparasitic drugs fail to be effectively transported to the lesion site. Studies on the mechanism of hepatic fibrosis caused by Echinococcus are important for treatment in patients. Recent studies have focused on miRNA and TGF-ß. More recent findings have focused on the generation of collagen fibers around the metacestode. In this review paper we focus on the mechanism by which the Echinococcus parasite induces fibrosis in liver and some other organs in intermediate hosts-animals as well as human beings.

Mmu-miR-92a-2-5p targets TLR2 to relieve Schistosoma japonicum-induced liver fibrosis.

According to conservative estimates, >230 million people are infected with schistosomiasis,which becomes one of the most common parasitic diseases. This study focuses on investigating in vivo and in vitro effects of mmu-miR-92a-2-5p in Schistosoma japonicum-induced liver fibrosis by targeting TLR2. Through bioinformatic analysis, the overexpression of TLR2 and the down-regulation of mmu-miR-92a-2-5p were revealed in the progression of S. japonicum-induced liver fibrosis. BALB/C mice were taken advantage to construct normal control and schistosomiasis liver fibrosis (SLF) model. The mice in model groups were transfected recombinant lentivirus (Lenti-mmu-miR-92a-2-5p or Lenti-NC) to alter the expression of mmu-miR-92a-2-5p in vivo. HE and Masson staining were employed to observe the pathological changes and collagenous fibrosis. QRT-PCR showed that mmu-miR-92a-2-5p was decreased while TLR2 was elevated in the infected groups. However, lenti-mmu-miR-92a-2-5p group could inhibit liver fibrosis. Then the effect of mmu-miR-92a-2-5p on S. japonicum-induced liver fibrosis including cell apoptosis rates, proliferation and proteins related to liver fibrosis was examined in NIH-3T3 mouse embryonic fibroblasts. Moreover, the association between mmu-miR-92a-2-5p and TLR2 was detected by dual-luciferase reporter gene assay and the expression of cytokines IL-4, IFN-γ and TNF-α in SLF model was detected by ELISA. Further, the knockout of TLR2 in C57BL/6J mice was used to confirm the association between mmu-miR-92a-2-5p and TLR2. Thus, these findings demonstrated that mmu-miR-92a-2-5p inhibited S. japonicum-induced liver fibrosis by targeting TLR2 in vitro and in vivo.

Inhibitory Effect of Ionizing Radiation on Echinococcus granulosus Hydatid Cyst.

BACKGROUND: Heavy ion radiation has more advantages than traditional radiation therapy in the treatment of cancer, mainly because of its superior biological effects. However, there is currently no reliable evidence that heavy ion radiation can induce cell death in hydatid cysts at the cellular and molecular level. In addition, we believe heavy ion therapy could be a potential alternative approach for the treatment of hydatid cysts. METHODOLOGY/PRINCIPAL FINDING: The hydatid cysts and protoscolices were obtained from an experimentally infected KunMing mice. LD50 was used to evaluate the death of the protoscolex. The cellular and ultrastructure of the parasites were observed under light and electron microscopes, the damage and copy numbers of mitochondrial DNA (mtDNA) were decided by QPCR. The apoptosis was evaluated by the expression and activity of caspase3. Dose-dependent ionizing radiation induced damage to the initial mtDNA. Echinococcosis cyst after ionizing radiation showed sparse cytoplasm, disorganized and clumped organelles, huge vacuoles, and villus deletions. The kinetic of DNA repair activity after X-ray irradiation was faster than those after carbon-ion irradiation. High doses of carbon ion radiation caused irreversible attenuation of mitochondrial DNA. Cysts showed obvious reduction in size after radiation. Carbon ion radiation was more effective than X-ray radiation in inhibiting hydatid cysts. CONCLUSIONS: These studies provide evidence that heavy-ion radiation can cause the extinction of hydatid cysts in vitro. The carbon-ion radiation is more advantageous than X-ray radiation in suppress hydatid cyst.

The MAPK Signaling Pathways as a Novel Way in Regulation and Treatment of Parasitic Diseases.

Few major advances in fighting parasitic diseases have been made in China since the development of new methods for prevention, control, and elimination. However, the proportion of immunocompromised individuals has increased due to the growth of chronic diseases, population aging, and more frequent cases of patients with AIDS and cancer. All these problems can promote development of parasitic infections, which is commonly associated with manipulation of host signaling pathways and the innate immune system. Mitogen-activated protein kinase (MAPK) signaling pathways are evolutionarily conserved in metazoan organisms, which play critical roles in the cell cycle, gene expression, growth, differentiation, apoptosis, and parasite⁻host interactions. Recent discoveries of the MAPK components involved in activation, regulation, and signal transduction appeared to be promising for the diagnosis, prevention, and treatment of parasitic diseases in the future. This review summarizes the involvement and critical role of the MAPK family in parasitic disease development and maintenance in the host. Moreover, it highlights recent studies concerning the mechanisms and novel drug development for inhibition and regulation of MAPK pathways in order to prevent parasitic disease. In addition, we discuss some antigenic proteins as prospective inhibitory molecules or vaccines for the regulation and control of MAPK signaling involved in parasite physiological activity.

The effects of CCR7 and related signaling pathways on Leishmania major -infected human dendritic cells.

OBJECTIVES: In our research, we aimed to investigate the roles of CC-chemokine receptor 7 (CCR7) and relevant signaling pathways in Leishmania major-infected human dendritic cells (DCs). METHODS: Differentially expressed genes (DEGs) in L. major-infected human DCs were selected out and visualized using R program. Kyoto Encyclopedia of Genes and Genomes pathway analysis was conducted for investigation of significantly enriched signaling pathways and Gene Ontology enrichment analysis was carried out for the unveiling of enriched Molecular Functions and Biological Processes in L. major-infected human DCs. Besides, Hub gene was screened out using weighted gene coexpression network analysis and Cytoscape. In addition, enzyme-linked immunosorbent assay and real-time quantitative polymerase chain reaction were used for detection of relative expression of CCR7, interleukin-12 (IL-12), and interferon-γ (IFN-γ) in L. major-infected human DCs and western blot analysis was used for detection of relative expression of CCR7 and other proteins in JAK-STAT signaling pathway in L. major-infected human DCs. RESULTS: CCR7 was upregulated and both chemokine and JAK-STAT signaling pathway were activated in L. major-infected human DCs. During the L. major infection, total number of L. major-infected human DCs were increased, as well as the relative expression levels of CCR7, IL-12, and IFN-γ and proteins in the JAK-STAT signaling pathway. Overexpression of CCR7 not only increased expression levels of IL-12 and IFN-γ but also activated the JAK-STAT signaling pathway to affect the leishmaniasis progression. CONCLUSION: L. major infection-induced activation of CCR7, as well as JAK2 and STAT1, might well upregulate the expression of BAX yet suppress the expression of both Bcl2 and c-Jun to affect leishmaniasis progression.

Heat shock protein 47 effects on hepatic stellate cell-associated receptors in hepatic fibrosis of Schistosoma japonicum-infected mice.

The study aimed to explore the regulation of heat shock protein 47 (HSP47) on expressions of receptors associated with hepatic stellate cell (HSC) in liver fibrosis mouse models induced by Schistosoma japonicum (S. japonicum). Mouse fibroblasts (NIH/3T3) were transfected with HSP47 shRNA plasmid by lipofectamine transfection, and experimental fibrosis in HSCs was studied in S. japonicum mouse models treated with HSP47 shRNA in vivo. HSP47 expression was assessed using Western blot and real-time PCR. Flow cytometry was adopted to determine the expression of cell membrane receptors. HSP47-shRNA could markedly down-regulate the expression of collagen (Col1a1 and Col3a1). The expressions of HSP47, endothelin receptor A (ETAR) and endothelin receptor B (ETBR) significantly increased in the liver tissue of infected mice. However, the expressions of ETAR and HSP47 and ETBR remarkably decreased after the administration of HSP47 shRNA in vitro and in vivo. ETAR and ETBR levels were found to be positively correlated with HSP47 expression. HSP47 might exert influence on liver fibrosis via the regulation of ETAR and ETBR.

[Investigation on echinococcosis in animals in Gannan Tibetan Autonomous Prefecture].

OBJECTIVE: To make an investigation on echinococcosis among animals in Gannan Tibetan Autonomous Prefecture. METHODS: 21 villages from Maqu and Luqu counties were selected for the survey in August of 2004-September of 2007. Rodents were trapped in the field. Sheep and yak livers, hearts and lungs were collected from the local slaughterhouses for pathological examination. Domestic dogs (shepherd dogs) were de-wormed by 15% arecoline to receive adult worms and stray dogs were shot for dissection. RESULTS: The prevalence of alveolar echinococcosis (AE) in Ochotona dahurica was 1.2% (1/87), and 2.3% (3/132) in Myospalax fontaniere, but no infection was found in Marmota himalayana, Ochotona tibetana and Mus musculus. 113 out of 1021 (11.1%) sheep were found infected with cystic echinococcosis (CE), and 3 (0.3%) with AE. 126 out of 634 (19.9%) yaks were infected with CE, and 2 yaks (0.3%) with AE. 17 out of 74 (23.0%) dogs were infected with Echinococcus granulosus (Eg), and 4 (5.4%) with Echinococcus multilocularis (Em). CONCLUSION: The results showed that there is a widespread endemic of Echinococcus granulosus in dogs and wild animals in Gannan Tibetan Autonomous Prefecture, with less Echinococcus multilocularis infection.