Role of adenylate kinase 1 in the integument development of Schistosoma japonicum schistosomula

Molecular characterization and immunological properties of Echinococcus granulosus sensu stricto (G1) ADK1 and ADK8

Adenylate kinases (ADKs) are one of the important enzymes regulating adenosine triphosphate (ATP) metabolism in Echinococcus granulosus sensu lato. The objective of the present study was to explore the molecular characteristics and immunological properties of E. granulosus sensu stricto (G1) adenylate kinase 1 (EgADK1) and adenylate kinase 8 (EgADK8). EgADK1 and EgADK8 were cloned and expressed, and the molecular characteristics of EgADK1 and EgADK8 were analyzed through different bioinformatics tools. Western blotting was used to examine the reactogenicity of recombinant adenylate kinase 1 (rEgADK1) and recombinant adenylate kinase 8 (rEgADK8) and to evaluate their diagnostic value. The expression profiles of EgADK1 and EgADK8 in 18-day-old strobilated worms and protoscoleces were analyzed by quantitative real-time PCR, and their distribution in 18-day-old strobilated worms, the germinal layer, and protoscoleces was determined by immunofluorescence localization. EgADK1 and EgADK8 were successfully cloned and expressed. Bioinformatics analysis predicted that EgADK1 and EgADK8 have multiple phosphorylation sites and B-cell epitopes. Compared with EgADK8, EgADK1 and other parasite ADKs have higher sequence similarity. In addition, both cystic echinococcosis (CE)-positive sheep sera and Cysticercus tenuicollis-infected goat sera could recognize rEgADK1 and rEgADK8. EgADK1 and EgADK8 were localized in protoscoleces, the germinal layer, and 18-day-old strobilated worms. EgADK1 and EgADK8 showed no significant difference in their transcription level in 18-day-old strobilated worms and protoscoleces, suggesting that EgADK1 and EgADK8 may play an important role in the growth and development of E. granulosus sensu lato. Since EgADK1 and EgADK8 can be recognized by other parasite-positive sera, they are not suitable as candidate antigens for the diagnosis of CE.

Glyceraldehyde-3-phosphate dehydrogenase affects the growth of Schistosoma japonicum schistosomula

This study was conducted to evaluate the effect of glyceraldehyde-3-phosphate dehydrogenase from Schistosoma japonicum (SjGAPDH) on the growth of schistosomula. Quantitative reverse transcription PCR and immunohistochemical analysis were performed to analyze the mRNA levels and immune localization of SjGAPDH. RNA interference experiments were conducted to further examine the role of SjGAPDH in the schistosomula growth of S. japonicum. The results demonstrated that SjGAPDH mRNA was expressed during all stages of S. japonicum development, with its expression gradually increasing over time. SjGAPDH was mainly distributed on the surface and in some parenchymal cells of S. japonicum. Double-stranded RNA-mediated GAPDH knockdown reduced SjGAPDH expression by approximately 59%. Light microscopic observations revealed that the size, length, width, volume, and area of schistosomula in the SjGAPDH interference group were significantly lower than those in the enhanced green fluorescent protein control group. These findings indicate that SjGAPDH may affect the growth of S. japonicum schistosomula and could be a useful target for treating schistosomiasis.

Involvement of the fatty acid-binding protein in the growth of Schistosoma japonicum schistosomula

This study aimed to explore the effect and mechanism underlying the role of the Schistosoma japonicum antigen of fatty acid-binding protein (SjFABP) on the growth of the schistosomula. SjFABP levels were evaluated by quantitative real-time polymerase chain reaction of samples of mice infected with S. japonicum; SjFABP was expressed and its levels gradually increased during all stages of S. japonicum schistosomula, including on 3, 10, 14, and 21 days of the growth process. Immunohistochemistry results demonstrated that SjFABP was distributed in the parenchyma, especially in the digestive tract of the S. japonicum schistosomula. RNA interference resulted in more than 60% knockdown of SjFABP leading to a reduction in length, volume, width, and area of the schistosomula as compared to control samples, as determined by light microscopy. Terminal deoxynucleotidyl transferase dUTP nick-end labeling detection further suggested that SjFABP knockdown resulted in increased apoptosis of schistosomes. Taken together, these results suggest that SjFABP may be related to the growth and survival of S. japonicum schistosomula, thereby representing a potential target for the treatment of schistosomiasis.