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Yan Ru Gao - One of the best experts on this subject based on the ideXlab platform.
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role of adenylate kinase 1 in the integument development of schistosoma japonicum Schistosomula
Acta Tropica, 2020Co-Authors: Yan Ru Gao, Lin Chen, Lei Lei, Jie GaoAbstract:Schistosomula antigens play an important role in the growth and development of Schistosoma japonicum. We investigated the role of S. japonicum adenylate kinase 1 (SjAK1) in the growth and development of Schistosomula. Quantitative real-time PCR showed that SjAK1 mRNA was expressed in all Schistosomula stages, but increased gradually with the development of S. japonicum Schistosomula. Using immunohistochemical techniques, the AK1 protein was found to be mainly distributed in the tegument and in some parenchymal tissues of the Schistosomula. Double-stranded RNA-mediated knockdown of AK1 reduced AK1 mRNA transcripts by more than 90%; western blot analysis demonstrated that AK1 protein expression decreased by 66%. Scanning electron microscopy following RNA-mediated AK1 knockdown demonstrated that the sensory papillae degenerated significantly. Transmission electron microscopy demonstrated that the mean thickness of the tegument in the SjAK1 interference group was lower than that in the negative control group. Terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) suggested that, compared with the negative control group, apoptosis increased in the interference group. These results show that AK1 may be involved in the growth and development of S. japonicum Schistosomula, and thus may be a target when developing treatments for schistosomiasis.
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influence of schistosoma japonicum programmed cell death protein 10 on the growth and development of Schistosomula
Parasites & Vectors, 2018Co-Authors: Yan Ru Gao, Wen Ling Huang, Chun Lian Tang, Rong Liu, Qin Ping Zhao, Zhen Ping Ming, Hui Fen DongAbstract:Schistosomiasis caused by Schistosoma japonicum is among the most serious endemic zoonoses in China. To study interactions between Schistosomula, the pre-adult juvenile stage, and hosts, it is important to study the functions of key genes involved in Schistosomula growth and development. Programmed cell death protein 10 (pcdp10) is an important apoptosis-related gene with various biological functions. This study described the molecular characterization of S. japonicum PCDP10 (SjPCDP10) and evaluated its functions in Schistosomula. Real-time quantitative polymerase chain reaction (qPCR) and western blot were used to detect Sjpcdp10 mRNA and protein levels, respectively, at different developmental stages. Immunolocalization was performed to determine SjPCDP10 expression in the parasite. RNA interference (RNAi) experiments were used to assess gene functions associated with SjPCDP10 in Schistosomula growth and development. Real-time qPCR revealed that Sjpcdp10 was expressed during all investigated developmental stages and upregulated during Schistosomula growth and development. Histochemical localization showed that SjPCDP10 was mainly distributed in the teguments of Schistosomula in all investigated stages and part of the parenchymal area of 14-, 18-, and 21-day-old Schistosomula. Following Sjpcdp10 knockdown by RNAi, the lengths, widths, areas, and volumes of Schistosomula were significantly lower than those in the control group. Scanning electron microscopy showed that the body surfaces of Schistosomula subjected to RNAi were seriously damaged, with few tegumental spines and sensory papillae. Transmission electron microscopy indicated that the teguments of Sjpcdp10-knockdown Schistosomula were incomplete, the number of layers was reduced, and the thickness decreased significantly as compared with those in the control group. Furthermore, terminal deoxynucleotidyl transferase dUTP nick-end labelling results showed that the rate of apoptosis in Sjpcdp10-knockdown Schistosomula was significantly higher than that in the control group. Sjpcdp10-knockdown influenced the growth and development of Schistosomula. Therefore, our results indicated that SjPCDP10 contributes to the regulation of cell apoptosis and is essential for Schistosomula growth and development.
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Influence of Schistosoma japonicum programmed cell death protein 10 on the growth and development of Schistosomula
BMC, 2018Co-Authors: Yan Ru Gao, Wen Ling Huang, Chun Lian Tang, Rong Liu, Qin Ping Zhao, Zhen Ping Ming, Hui Fen DongAbstract:Abstract Background Schistosomiasis caused by Schistosoma japonicum is among the most serious endemic zoonoses in China. To study interactions between Schistosomula, the pre-adult juvenile stage, and hosts, it is important to study the functions of key genes involved in Schistosomula growth and development. Programmed cell death protein 10 (pcdp10) is an important apoptosis-related gene with various biological functions. This study described the molecular characterization of S. japonicum PCDP10 (SjPCDP10) and evaluated its functions in Schistosomula. Methods Real-time quantitative polymerase chain reaction (qPCR) and western blot were used to detect Sjpcdp10 mRNA and protein levels, respectively, at different developmental stages. Immunolocalization was performed to determine SjPCDP10 expression in the parasite. RNA interference (RNAi) experiments were used to assess gene functions associated with SjPCDP10 in Schistosomula growth and development. Results Real-time qPCR revealed that Sjpcdp10 was expressed during all investigated developmental stages and upregulated during Schistosomula growth and development. Histochemical localization showed that SjPCDP10 was mainly distributed in the teguments of Schistosomula in all investigated stages and part of the parenchymal area of 14-, 18-, and 21-day-old Schistosomula. Following Sjpcdp10 knockdown by RNAi, the lengths, widths, areas, and volumes of Schistosomula were significantly lower than those in the control group. Scanning electron microscopy showed that the body surfaces of Schistosomula subjected to RNAi were seriously damaged, with few tegumental spines and sensory papillae. Transmission electron microscopy indicated that the teguments of Sjpcdp10-knockdown Schistosomula were incomplete, the number of layers was reduced, and the thickness decreased significantly as compared with those in the control group. Furthermore, terminal deoxynucleotidyl transferase dUTP nick-end labelling results showed that the rate of apoptosis in Sjpcdp10-knockdown Schistosomula was significantly higher than that in the control group. Conclusions Sjpcdp10-knockdown influenced the growth and development of Schistosomula. Therefore, our results indicated that SjPCDP10 contributes to the regulation of cell apoptosis and is essential for Schistosomula growth and development
Jiaojiao Lin - One of the best experts on this subject based on the ideXlab platform.
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comparative characterization of micrornas in schistosoma japonicum Schistosomula from wistar rats and balb c mice
Parasitology Research, 2015Co-Authors: Hongxiao Han, Jinbiao Peng, Yang Hong, Chuangang Zhu, Qiuhua Zhao, Jiaojiao LinAbstract:More than 40 kinds of mammals in China are known to be naturally infected with Schistosoma japonicum (S. japonicum) (Peng et al. Parasitol Res 106:967–76, 2010). Compared with permissive BALB/c mice, rats are less susceptible to S. japonicum infection and are considered to provide an unsuitable microenvironment for parasite growth and development. MicroRNAs (miRNAs), via the regulation of gene expression at the transcriptional and post-transcriptional levels, may be responsible for developmental differences between Schistosomula in these two rodent hosts. Solexa deep-sequencing technology was used to identify differentially expressed miRNAs from Schistosomula isolated from Wistar rats and BALB/c mice 10 days post-infection. The deep-sequencing analysis revealed that nearly 40 % of raw reads (10.37 and 10.84 million reads in Schistosomula isolated from Wistar rats and BALB/c mice, respectively) can be mapped to selected mirs in miRBase or in species-specific genomes. Further analysis revealed that several miRNAs were differentially expressed in Schistosomula isolated from these two rodents; 18 were downregulated (by 2-fold) (expression levels in rats compare with those in mice). Additionally, three novel miRNAs were primarily predicted and identified. Among the 41 differentially expressed miRNAs, 4 miRNAs had been identified with specific functions in schistosome development or host-parasite interaction, such as sexual maturation (sja-miR-1, sja-miR-7-5p), embryo development (sja-miR-36-3p) in schistosome, and pathogenesis of schistosomiasis (sja-bantam). Then, the target genes were mapped, filtered, and correlated with a set of genes that were differentially expressed genes in Schistosomula isolated from mice and rats, which we identified in a S. japonicum oligonucleotide microarray analysis in a previous study. Gene Ontology (GO) analysis of the predicted target genes of 13 differentially expressed miRNAs revealed that they were involved in some important biological pathways, such as metabolic processes, the regulation of protein catabolic processes, catalytic activity, oxidoreductase activity, and hydrolase activity. The study presented here includes the first identification of differentially expressed miRNAs between Schistosomula in mice or rats. Therefore, we hypothesized that the differentially expressed miRNAs may affect the development, growth, and maturation of the schistosome in its life cycle. Our analysis suggested that some differentially expressed miRNAs may impact the survival and development of the parasite within a host. This study increases our understanding of schistosome development and host-parasite interactions.
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proteomics analysis of differentially expressed proteins in Schistosomula and adult worms of schistosoma japonicum
Acta Tropica, 2013Co-Authors: Yang Hong, Yaojun Shi, Anguo Sun, Min Zhang, Fei Gao, Yanhui Han, Jiaojiao LinAbstract:Schistosoma japonicum has a complex lifecycle and exhibits dramatic changes in its biology and morphology at different developmental stages. The schistosomulum and adult worm are two stages of this complex lifecycle and differentially expressed proteins in these two stages should be important for survival, development, and reproduction of the parasites. In this study, soluble and hydrophobic proteins were extracted from eggs, cercariae, Schistosomula (8d and 19d), and male and female adult worms (42d) of Schistosoma japonicum, and separated by two-dimensional (2D) gel electrophoresis. A total of 1376±52, 928±61, 1465±41, 1230±30, 904±34, and 1080±26 soluble proteins and 1437±44, 845±53, 986±22, 1145±35, 1066±39, and 1123±45 hydrophobic proteins were separated from eggs, cercariae, Schistosomula (8d and 19d), and male and female adult worms (42d), respectively. There were 65±14, 27±7, 37±17 and 48±9 soluble protein spots only present in Schistosomula (8d and/or 19d) and adult schistosomes (male and/or female). We successfully identified 22 spots from Schistosomula and 11 spots from adult schistosomes by mass spectrometry. Quantitative real-time RT-PCR was used to examine six differentially expressed proteins at the transcription level. These proteins only found in Schistosomula or adults stage by the proteomics analysis were highly expressed in the corresponding stage at mRNA level. Bioinformatics analysis showed that the differentially expressed proteins from Schistosomula were mainly involved in cellular metabolic processes, stress response and developmental process. Differentially expressed proteins from adult schistosomes were involved with gene expression and protein metabolism processes. The results of this study might provide new insights to stimulate further exploration of the mechanism of growth and development in schistosomes and help identify candidate molecules for developing new vaccines or drugs.
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apoptosis governs the elimination of schistosoma japonicum from the non permissive host microtus fortis
PLOS ONE, 2011Co-Authors: Jinbiao Peng, Yaojun Shi, Geoffrey N Gobert, Yang Hong, Weibin Jiang, Hongxiao Han, Donald P Mcmanus, Xinzhi Wang, Jinming Liu, Jiaojiao LinAbstract:The reed vole, Microtus fortis, is the only known mammalian host in which schistosomes of Schistosoma japonicum are unable to mature and cause significant pathogenesis. However, little is known about how Schistosoma japonicum maturation (and, therefore, the development of schistosomiasis) is prevented in M. fortis. In the present study, the ultrastructure of 10 days post infection Schistosomula from BALB/c mice and M. fortis were first compared using scanning electron microscopy and transmission electron microscopy. Electron microscopic investigations showed growth retardation and ultrastructural differences in the tegument and sub-tegumental tissues as well as in the parenchymal cells of Schistosomula from M. fortis compared with those in BALB/c mice. Then, microarray analysis revealed significant differential expression between the Schistosomula from the two rodents, with 3,293 down-regulated (by ≥2-fold) and 71 up-regulated (≥2 fold) genes in Schistosomula from the former. The up-regulated genes included a proliferation-related gene encoding granulin (Grn) and tropomyosin. Genes that were down-regulated in Schistosomula from M. fortis included apoptosis-inhibited genes encoding a baculoviral IAP repeat-containing protein (SjIAP) and cytokine-induced apoptosis inhibitor (SjCIAP), genes encoding molecules involved in insulin metabolism, long-chain fatty acid metabolism, signal transduction, the transforming growth factor (TGF) pathway, the Wnt pathway and in development. TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) and PI/Annexin V-FITC assays, caspase 3/7 activity analysis, and flow cytometry revealed that the percentages of early apoptotic and late apoptotic and/or necrotic cells, as well as the level of caspase activity, in Schistosomula from M. fortis were all significantly higher than in those from BALB/c mice.
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analysis of early hepatic stage Schistosomula gene expression by subtractive expressed sequence tags library
Molecular and Biochemical Parasitology, 2009Co-Authors: Xinzhi Wang, Jinbiao Peng, Geoffrey N Gobert, Xingang Feng, Yamei Jin, Jiaojiao LinAbstract:Schistosome parasites require a complex lifecycle requiring two hosts and aquatic phases of development. The Schistosomula is a key phase of parasite development within the mammalian host, however relatively little is understood about the molecular processes underlying this stage. In this study 5723 subtractive expressed sequence tags (ESTs) were randomly selected from a 7 day hepatic Schistosomula enriched library constructed using suppression subtractive hybridization method. Sequence analysis of these ESTs identified 1762 unique genes (contigs). Among them, 989 contigs were annotated with known genes, 311 contigs were homologous to established genes, 101 contigs were similar to established genes, 72 contigs were weakly similar to established genes and 289 sequences did not match any published sequences. Genes identified related to metabolism, cellular development, immune evasion and host-parasite interactions were identified as enriched in the hepatic Schistosomula stage. The future identification of poorly annotated but stage-specific genes may potentially represent new drugs or vaccine targets, applicable for the future controlling of schistosomiasis.
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Vaccination of bovines against Schistosomiasis japonica with cryopreserved-irradiated and freeze-thaw Schistosomula.
Veterinary parasitology, 1993Co-Authors: Fuhui Shi, Jiaojiao Lin, Wei Shen, Yinghua Wang, Bangfa Lin, Chengui Qian, Yaojun ShiAbstract:Abstract Four laboratory tests and one field trial with cryopreserved irradiated (CI) Schistosomula vaccine and a freeze-thaw (F/T) vaccine against bovine Schistosomiasis japonica were carried out in 1979 and 1980 with the following results: (1) Single intradermal vaccination in buffalo calves each with 10 000 20 krad CI Schistosomula plus 1 ml BCG gave 62% worm reduction (P
Hui Fen Dong - One of the best experts on this subject based on the ideXlab platform.
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influence of schistosoma japonicum programmed cell death protein 10 on the growth and development of Schistosomula
Parasites & Vectors, 2018Co-Authors: Yan Ru Gao, Wen Ling Huang, Chun Lian Tang, Rong Liu, Qin Ping Zhao, Zhen Ping Ming, Hui Fen DongAbstract:Schistosomiasis caused by Schistosoma japonicum is among the most serious endemic zoonoses in China. To study interactions between Schistosomula, the pre-adult juvenile stage, and hosts, it is important to study the functions of key genes involved in Schistosomula growth and development. Programmed cell death protein 10 (pcdp10) is an important apoptosis-related gene with various biological functions. This study described the molecular characterization of S. japonicum PCDP10 (SjPCDP10) and evaluated its functions in Schistosomula. Real-time quantitative polymerase chain reaction (qPCR) and western blot were used to detect Sjpcdp10 mRNA and protein levels, respectively, at different developmental stages. Immunolocalization was performed to determine SjPCDP10 expression in the parasite. RNA interference (RNAi) experiments were used to assess gene functions associated with SjPCDP10 in Schistosomula growth and development. Real-time qPCR revealed that Sjpcdp10 was expressed during all investigated developmental stages and upregulated during Schistosomula growth and development. Histochemical localization showed that SjPCDP10 was mainly distributed in the teguments of Schistosomula in all investigated stages and part of the parenchymal area of 14-, 18-, and 21-day-old Schistosomula. Following Sjpcdp10 knockdown by RNAi, the lengths, widths, areas, and volumes of Schistosomula were significantly lower than those in the control group. Scanning electron microscopy showed that the body surfaces of Schistosomula subjected to RNAi were seriously damaged, with few tegumental spines and sensory papillae. Transmission electron microscopy indicated that the teguments of Sjpcdp10-knockdown Schistosomula were incomplete, the number of layers was reduced, and the thickness decreased significantly as compared with those in the control group. Furthermore, terminal deoxynucleotidyl transferase dUTP nick-end labelling results showed that the rate of apoptosis in Sjpcdp10-knockdown Schistosomula was significantly higher than that in the control group. Sjpcdp10-knockdown influenced the growth and development of Schistosomula. Therefore, our results indicated that SjPCDP10 contributes to the regulation of cell apoptosis and is essential for Schistosomula growth and development.
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Influence of Schistosoma japonicum programmed cell death protein 10 on the growth and development of Schistosomula
BMC, 2018Co-Authors: Yan Ru Gao, Wen Ling Huang, Chun Lian Tang, Rong Liu, Qin Ping Zhao, Zhen Ping Ming, Hui Fen DongAbstract:Abstract Background Schistosomiasis caused by Schistosoma japonicum is among the most serious endemic zoonoses in China. To study interactions between Schistosomula, the pre-adult juvenile stage, and hosts, it is important to study the functions of key genes involved in Schistosomula growth and development. Programmed cell death protein 10 (pcdp10) is an important apoptosis-related gene with various biological functions. This study described the molecular characterization of S. japonicum PCDP10 (SjPCDP10) and evaluated its functions in Schistosomula. Methods Real-time quantitative polymerase chain reaction (qPCR) and western blot were used to detect Sjpcdp10 mRNA and protein levels, respectively, at different developmental stages. Immunolocalization was performed to determine SjPCDP10 expression in the parasite. RNA interference (RNAi) experiments were used to assess gene functions associated with SjPCDP10 in Schistosomula growth and development. Results Real-time qPCR revealed that Sjpcdp10 was expressed during all investigated developmental stages and upregulated during Schistosomula growth and development. Histochemical localization showed that SjPCDP10 was mainly distributed in the teguments of Schistosomula in all investigated stages and part of the parenchymal area of 14-, 18-, and 21-day-old Schistosomula. Following Sjpcdp10 knockdown by RNAi, the lengths, widths, areas, and volumes of Schistosomula were significantly lower than those in the control group. Scanning electron microscopy showed that the body surfaces of Schistosomula subjected to RNAi were seriously damaged, with few tegumental spines and sensory papillae. Transmission electron microscopy indicated that the teguments of Sjpcdp10-knockdown Schistosomula were incomplete, the number of layers was reduced, and the thickness decreased significantly as compared with those in the control group. Furthermore, terminal deoxynucleotidyl transferase dUTP nick-end labelling results showed that the rate of apoptosis in Sjpcdp10-knockdown Schistosomula was significantly higher than that in the control group. Conclusions Sjpcdp10-knockdown influenced the growth and development of Schistosomula. Therefore, our results indicated that SjPCDP10 contributes to the regulation of cell apoptosis and is essential for Schistosomula growth and development
Yang Hong - One of the best experts on this subject based on the ideXlab platform.
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comparative characterization of micrornas in schistosoma japonicum Schistosomula from wistar rats and balb c mice
Parasitology Research, 2015Co-Authors: Hongxiao Han, Jinbiao Peng, Yang Hong, Chuangang Zhu, Qiuhua Zhao, Jiaojiao LinAbstract:More than 40 kinds of mammals in China are known to be naturally infected with Schistosoma japonicum (S. japonicum) (Peng et al. Parasitol Res 106:967–76, 2010). Compared with permissive BALB/c mice, rats are less susceptible to S. japonicum infection and are considered to provide an unsuitable microenvironment for parasite growth and development. MicroRNAs (miRNAs), via the regulation of gene expression at the transcriptional and post-transcriptional levels, may be responsible for developmental differences between Schistosomula in these two rodent hosts. Solexa deep-sequencing technology was used to identify differentially expressed miRNAs from Schistosomula isolated from Wistar rats and BALB/c mice 10 days post-infection. The deep-sequencing analysis revealed that nearly 40 % of raw reads (10.37 and 10.84 million reads in Schistosomula isolated from Wistar rats and BALB/c mice, respectively) can be mapped to selected mirs in miRBase or in species-specific genomes. Further analysis revealed that several miRNAs were differentially expressed in Schistosomula isolated from these two rodents; 18 were downregulated (by 2-fold) (expression levels in rats compare with those in mice). Additionally, three novel miRNAs were primarily predicted and identified. Among the 41 differentially expressed miRNAs, 4 miRNAs had been identified with specific functions in schistosome development or host-parasite interaction, such as sexual maturation (sja-miR-1, sja-miR-7-5p), embryo development (sja-miR-36-3p) in schistosome, and pathogenesis of schistosomiasis (sja-bantam). Then, the target genes were mapped, filtered, and correlated with a set of genes that were differentially expressed genes in Schistosomula isolated from mice and rats, which we identified in a S. japonicum oligonucleotide microarray analysis in a previous study. Gene Ontology (GO) analysis of the predicted target genes of 13 differentially expressed miRNAs revealed that they were involved in some important biological pathways, such as metabolic processes, the regulation of protein catabolic processes, catalytic activity, oxidoreductase activity, and hydrolase activity. The study presented here includes the first identification of differentially expressed miRNAs between Schistosomula in mice or rats. Therefore, we hypothesized that the differentially expressed miRNAs may affect the development, growth, and maturation of the schistosome in its life cycle. Our analysis suggested that some differentially expressed miRNAs may impact the survival and development of the parasite within a host. This study increases our understanding of schistosome development and host-parasite interactions.
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proteomics analysis of differentially expressed proteins in Schistosomula and adult worms of schistosoma japonicum
Acta Tropica, 2013Co-Authors: Yang Hong, Yaojun Shi, Anguo Sun, Min Zhang, Fei Gao, Yanhui Han, Jiaojiao LinAbstract:Schistosoma japonicum has a complex lifecycle and exhibits dramatic changes in its biology and morphology at different developmental stages. The schistosomulum and adult worm are two stages of this complex lifecycle and differentially expressed proteins in these two stages should be important for survival, development, and reproduction of the parasites. In this study, soluble and hydrophobic proteins were extracted from eggs, cercariae, Schistosomula (8d and 19d), and male and female adult worms (42d) of Schistosoma japonicum, and separated by two-dimensional (2D) gel electrophoresis. A total of 1376±52, 928±61, 1465±41, 1230±30, 904±34, and 1080±26 soluble proteins and 1437±44, 845±53, 986±22, 1145±35, 1066±39, and 1123±45 hydrophobic proteins were separated from eggs, cercariae, Schistosomula (8d and 19d), and male and female adult worms (42d), respectively. There were 65±14, 27±7, 37±17 and 48±9 soluble protein spots only present in Schistosomula (8d and/or 19d) and adult schistosomes (male and/or female). We successfully identified 22 spots from Schistosomula and 11 spots from adult schistosomes by mass spectrometry. Quantitative real-time RT-PCR was used to examine six differentially expressed proteins at the transcription level. These proteins only found in Schistosomula or adults stage by the proteomics analysis were highly expressed in the corresponding stage at mRNA level. Bioinformatics analysis showed that the differentially expressed proteins from Schistosomula were mainly involved in cellular metabolic processes, stress response and developmental process. Differentially expressed proteins from adult schistosomes were involved with gene expression and protein metabolism processes. The results of this study might provide new insights to stimulate further exploration of the mechanism of growth and development in schistosomes and help identify candidate molecules for developing new vaccines or drugs.
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apoptosis governs the elimination of schistosoma japonicum from the non permissive host microtus fortis
PLOS ONE, 2011Co-Authors: Jinbiao Peng, Yaojun Shi, Geoffrey N Gobert, Yang Hong, Weibin Jiang, Hongxiao Han, Donald P Mcmanus, Xinzhi Wang, Jinming Liu, Jiaojiao LinAbstract:The reed vole, Microtus fortis, is the only known mammalian host in which schistosomes of Schistosoma japonicum are unable to mature and cause significant pathogenesis. However, little is known about how Schistosoma japonicum maturation (and, therefore, the development of schistosomiasis) is prevented in M. fortis. In the present study, the ultrastructure of 10 days post infection Schistosomula from BALB/c mice and M. fortis were first compared using scanning electron microscopy and transmission electron microscopy. Electron microscopic investigations showed growth retardation and ultrastructural differences in the tegument and sub-tegumental tissues as well as in the parenchymal cells of Schistosomula from M. fortis compared with those in BALB/c mice. Then, microarray analysis revealed significant differential expression between the Schistosomula from the two rodents, with 3,293 down-regulated (by ≥2-fold) and 71 up-regulated (≥2 fold) genes in Schistosomula from the former. The up-regulated genes included a proliferation-related gene encoding granulin (Grn) and tropomyosin. Genes that were down-regulated in Schistosomula from M. fortis included apoptosis-inhibited genes encoding a baculoviral IAP repeat-containing protein (SjIAP) and cytokine-induced apoptosis inhibitor (SjCIAP), genes encoding molecules involved in insulin metabolism, long-chain fatty acid metabolism, signal transduction, the transforming growth factor (TGF) pathway, the Wnt pathway and in development. TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) and PI/Annexin V-FITC assays, caspase 3/7 activity analysis, and flow cytometry revealed that the percentages of early apoptotic and late apoptotic and/or necrotic cells, as well as the level of caspase activity, in Schistosomula from M. fortis were all significantly higher than in those from BALB/c mice.
James H Mckerrow - One of the best experts on this subject based on the ideXlab platform.
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drug discovery for schistosomiasis hit and lead compounds identified in a library of known drugs by medium throughput phenotypic screening
PLOS Neglected Tropical Diseases, 2009Co-Authors: Maha Hamadien Abdulla, Debbie S Ruelas, Brian Wolff, June Snedecor, Kee Chong Lim, Adam R Renslo, Janice Williams, James H Mckerrow, Conor R CaffreyAbstract:Background Praziquantel (PZQ) is the only widely available drug to treat schistosomiasis. Given the potential for drug resistance, it is prudent to search for novel therapeutics. Identification of anti-schistosomal chemicals has traditionally relied on phenotypic (whole organism) screening with adult worms in vitro and/or animal models of disease—tools that limit automation and throughput with modern microtiter plate-formatted compound libraries. Methods A partially automated, three-component phenotypic screen workflow is presented that utilizes at its apex the Schistosomular stage of the parasite adapted to a 96-well plate format with a throughput of 640 compounds per month. Hits that arise are subsequently screened in vitro against adult parasites and finally for efficacy in a murine model of disease. Two GO/NO GO criteria filters in the workflow prioritize hit compounds for tests in the animal disease model in accordance with a target drug profile that demands short-course oral therapy. The screen workflow was inaugurated with 2,160 chemically diverse natural and synthetic compounds, of which 821 are drugs already approved for human use. This affords a unique starting point to ‘reposition’ (re-profile) drugs as anti-schistosomals with potential savings in development timelines and costs. Findings Multiple and dynamic phenotypes could be categorized for Schistosomula and adults in vitro, and a diverse set of ‘hit’ drugs and chemistries were identified, including anti-schistosomals, anthelmintics, antibiotics, and neuromodulators. Of those hits prioritized for tests in the animal disease model, a number of leads were identified, one of which compares reasonably well with PZQ in significantly decreasing worm and egg burdens, and disease-associated pathology. Data arising from the three components of the screen are posted online as a community resource. Conclusions To accelerate the identification of novel anti-schistosomals, we have developed a partially automated screen workflow that interfaces Schistosomula with microtiter plate-formatted compound libraries. The workflow has identified various compounds and drugs as hits in vitro and leads, with the prescribed oral efficacy, in vivo. Efforts to improve throughput, automation, and rigor of the screening workflow are ongoing.
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drug discovery for schistosomiasis hit and lead compounds identified in a library of known drugs by medium throughput phenotypic screening
PLOS Neglected Tropical Diseases, 2009Co-Authors: Maha Hamadien Abdulla, Debbie S Ruelas, Brian Wolff, June Snedecor, Adam R Renslo, Janice Williams, James H Mckerrow, Fengyun Xu, Conor R CaffreyAbstract:Background Praziquantel (PZQ) is the only widely available drug to treat schistosomiasis. Given the potential for drug resistance, it is prudent to search for novel therapeutics. Identification of anti-schistosomal chemicals has traditionally relied on phenotypic (whole organism) screening with adult worms in vitro and/or animal models of disease—tools that limit automation and throughput with modern microtiter plate-formatted compound libraries. Methods A partially automated, three-component phenotypic screen workflow is presented that utilizes at its apex the Schistosomular stage of the parasite adapted to a 96-well plate format with a throughput of 640 compounds per month. Hits that arise are subsequently screened in vitro against adult parasites and finally for efficacy in a murine model of disease. Two GO/NO GO criteria filters in the workflow prioritize hit compounds for tests in the animal disease model in accordance with a target drug profile that demands short-course oral therapy. The screen workflow was inaugurated with 2,160 chemically diverse natural and synthetic compounds, of which 821 are drugs already approved for human use. This affords a unique starting point to ‘reposition’ (re-profile) drugs as anti-schistosomals with potential savings in development timelines and costs. Findings Multiple and dynamic phenotypes could be categorized for Schistosomula and adults in vitro, and a diverse set of ‘hit’ drugs and chemistries were identified, including anti-schistosomals, anthelmintics, antibiotics, and neuromodulators. Of those hits prioritized for tests in the animal disease model, a number of leads were identified, one of which compares reasonably well with PZQ in significantly decreasing worm and egg burdens, and disease-associated pathology. Data arising from the three components of the screen are posted online as a community resource. Conclusions To accelerate the identification of novel anti-schistosomals, we have developed a partially automated screen workflow that interfaces Schistosomula with microtiter plate-formatted compound libraries. The workflow has identified various compounds and drugs as hits in vitro and leads, with the prescribed oral efficacy, in vivo. Efforts to improve throughput, automation, and rigor of the screening workflow are ongoing.
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multiple cathepsin b isoforms in Schistosomula of trichobilharzia regenti identification characterisation and putative role in migration and nutrition
International Journal for Parasitology, 2005Co-Authors: Jan Dvořak, Libor Mikeš, Melaine Delcroix, Andrea Rossi, Vaclav Vopalenský, Martin Pospisek, Miroslava Sedinova, Mohammed Sajid, Andrej Sali, James H MckerrowAbstract:Abstract Among schistosomatids, Trichobilharzia regenti, displays an unusual migration through the peripheral and central nervous system prior to residence in the nasal cavity of the definitive avian host. Migration causes tissue degradation and neuromotor dysfunction both in birds and experimentally infected mice. Although Schistosomula have a well-developed gut, the peptidases elaborated that might facilitate nutrition and migration are unknown. This is, in large part, due to the difficulty in isolating large numbers of migrating larvae. We have identified and characterised the major 33 kDa cathepsin B-like cysteine endopeptidase in extracts of migrating Schistosomula using fluorogenic peptidyl substrates with high extinction coefficients and irreversible affinity-labels. From first strand Schistosomula cDNA, degenerate PCR and Rapid Amplification of cDNA End protocols were used to identify peptidase isoforms termed TrCB1.1–TrCB1.6. Highest sequence homology is to the described Schistosoma mansoni and Schistosoma japonicum cathepsins B1. Two isoforms (TrCB1.5 and 1.6) encode putatively inactive enzymes as the catalytic cysteine is substituted by glycine. Two other isoforms, TrCB1.1 and 1.4, were functionally expressed as zymogens in Pichia pastoris. Specific polyclonal antibodies localised the peptidases exclusively in the gut of Schistosomula and reacted with a 33 kDa protein in worm extracts. TrCB1.1 zymogen was unable to catalyse its own activation, but was trans-processed and activated by S. mansoni asparaginyl endopeptidase (SmAE aka. S. mansoni legumain). In contrast, TrCB1.4 zymogen auto-activated, but was resistant to the action of SmAE. Both activated isoforms displayed different pH-dependent specificity profiles with peptidyl substrates. Also, both isoforms degraded myelin basic protein, the major protein component of nervous tissue, but were inefficient against hemoglobin, thus supporting the adaptation of T. regenti gut peptidases to parasitism of host nervous tissue.
