microRNAs expression profiles in Schistosoma japonicum of different sex 14 and 28 days post-infection

@#Different miRNAs are involved in the life cycles of Schistosoma japonicum. The aim of this study was to examine the expression profile of miRNAs in individual S. japonicum of different sex before and after pairing (18 and 24 dpi). The majority of differential expressed miRNAs were highly abundant at 14 dpi, except for sja-miR-125b and sja-miR-3505, in both male and female. Moreover, it was estimated that sja-miR-125b and sja-miR-3505 might be related to laying eggs. sja-miR-2a-5p and sja-miR-3484-5p were expressed at 14 dpi in males and were significantly clustered in DNA topoisomerase III, Rap guanine nucleotide exchange factor 1 and L-serine/L-threonine ammonia-lyase. Target genes of sja-miR-2d-5p, sja-miR-31- 5p and sja-miR-125a, which were expressed at 14 dpi in males but particularly females, were clustered in kelch-like protein 12, fructose-bisphosphate aldolase, class I, and heat shock protein 90 kDa beta. Predicted target genes of sja-miR-3483-3p (expressed at 28 dpi in females but not in males) were clustered in 26S proteasome regulatory subunit N1, ATPdependent RNA helicase DDX17. Predicted target genes of sja-miR-219-5p, which were differentially expressed at 28 dpi in females but particularly males, were clustered in DNA excision repair protein ERCC-6, protein phosphatase 1D, and ATPase family AAA domaincontaining protein 3A/B. Moreover, at 28 dpi, eight miRNAs were significantly up-regulated in females compared to males. The predicted target genes of these miRNAs were significantly clustered in heat shock protein 90 kDa beta, 26S proteasome regulatory subunit N1, and protein arginine N-methyltransferase 1. To sum up, differentially expressed miRNAs may have an essential role and provide necessary information on clarifying this trematode’s growth, development, maturation, and infection ability to mammalian hosts in its complex life cycle, and may be helpful for developing new drug targets and vaccine candidates for schistosomiasis.

Effect of estradiol and bisphenol A on human hepatoblastoma cell viability and telomerase activity

Sex hormones from environmental and physiological sources might play a major role in the pathogenesis of hepatoblastoma in children. This study investigated the effects of estradiol and bisphenol A on the proliferation and telomerase activity of human hepatoblastoma HepG2 cells. The cells were divided into 6 treatment groups: control, bisphenol A, estradiol, anti-estrogen ICI 182,780 (hereinafter ICI), bisphenol A+ICI, and estradiol+ICI. Cell proliferation was measured based on average absorbance using the Cell Counting-8 assay. The cell cycle distribution and apoptotic index were determined by flow cytometry. Telomerase activity was detected by polymerase chain reaction and a telomeric repeat amplification protocol assay. A higher cell density was observed in bisphenol A (P<0.01) and estradiol (P<0.05) groups compared with the control group. Cell numbers in S and G2/M phases after treatment for 48 h were higher (P<0.05), while the apoptotic index was lower (P<0.05) and telomerase activities at 48 and 72 h (P<0.05) were higher in these groups than in the control group. The cell density was also higher in bisphenol A+ICI (P<0.01) and estradiol+ICI (P<0.05) groups compared with the ICI group. Furthermore, cell numbers were increased in S and G2/M phases (P<0.05), while the apoptotic index was lower (P<0.05) and telomerase activities at 48 and 72 h were higher (P<0.05) in these groups than in the ICI group. Therefore, bisphenol A and estradiol promote HepG2 cell proliferation in vitro by inhibition of apoptosis and stimulation of telomerase activity via an estrogen receptor-dependent pathway.

Analysis of Structures, Functions, and Epitopes of Aminopeptidase from Trichinella spiralis

We have previously reported that the recombinant T. spiralis aminopeptidase (rTsAP) could induce a partial protective immunity against T. spiralis infection in mice. The aim of this study was to predict the structures and functions of TsAP protein by using the full length cDNA sequence of TsAP gene. TsAP sequence was 1515 bp length with a 1515 bp biggest ORF encoding 504-amino acid protein. The molecular weight and isoelectric point of TsAP were 54.7 kDa and 6.69, respectively. TsAP structure domains contained a Peptidase_M17_N and a Peptidase_M17 domain, which has the function of catalysis of the hydrolysis of N-terminal amino acid residues. TsAP had no signal peptide site and transmembrane domain, and located in cytoplasm. The secondary structure of TsAP contained 16 α-helix, 14 β-strand and 29 coils. The TsAP had 11 and 21 potential antigenic epitopes of T cell and B cell, respectively. Based on the phylogenetic analyses of TsAP, T. spiralis have the closest relationship with Plasmodium falciparum. TsAP was a kind of proteolytic enzyme with a variety of biological functions and its antigenic epitopes could provide important insights on the diagnostic antigens and target molecular of anti-Trichinella drugs

Construction of a recombinant plasmid harbouring the glyceraldenyde-3-phosphate dehydrogenase gene of periodic Brugia malayi and observation on DNA immunity.

Purpose: Controlling and eliminating lymphatic filariasis will require further research of preventative measures and implementation. Parasite is dependent on glycolysis for ATP production. The glycolytic enzyme glyceraldenyde-3-phosphate dehydrogenase (GAPDH) plays an important role in glycolysis and therefore is either a potential target for anti-parasite drug development or a vaccine candidate. Therefore, we tried to investigate the DNA vaccine-elicited immune responses in BALB/c mice. Materials and Methods: We cloned a gene encoding the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) from periodic Brugia malayi into vector pcDNA3.1. Mice were injected at a dosage of 100 μg recombinant plasmid DNA with CpG intramuscular injection and immunized three times at 2-week intervals. pcDNA3.1 and normal saline were used as control. The tissue of muscles at the 4 weeks after the third injection was collected and target genes were detected using RT-PCR. The humoral responses elicited in mice by inoculation with the recombinant plasmid pcDNA3.1-BmGAPDH were detected using a standard ELISA. Two weeks after the third immunization, stimulation index (SI) was measured using the MTT method and the level of secreted IL-4 and INF-g were detected using ELISA. Results: Specific gene fragment coding GAPDH was amplified and the recombinant plasmid pcDNA3.1-BmGAPDH was constructed. Post-challenge sera from the mice immunized with the DNA vaccine had specific antibody titres of 1:1600 to 1:6400, and the highest titre was observed in the mice that were inoculated by pcDNA3.1-BmGAPDH/CpG at 6 weeks. At 4 weeks after immunization, the spleens of the mice were obviously enlarged. The proliferation of spleen T lymphocytes seen on the MTT assay was higher in the pcDNA3.1-BmGAPDH group than in the control group (P value <0.05). The levels of IL-4 and INF-g in serums from the immunized mice were significantly higher than that of the control (P value <0.05). Conclusions: We conclude that the recombinant eukaryotic plasmid pcDNA3.1-BmGAPDH could elicit humoral and cellular immune responses in mice.

Studies on the transmission potential of surviving microfilaremias after basic control of filariasis.

After filariasis was basically controlled (the microfilarial rate was lower than 1%) in Henan Province in 1987, longitudinal observation of the disease has been carried out in all the province in order to study the regular pattern of growth and decline or the transmission potential of the disease. According to the distribution of filaria species and original microfilarial rate, 7 administrative villages in 7 counties were selected as surveillance sites. From 1988 to 1995, etiological and mosquito vector surveys were made continuously in all sites where no control measure was conducted. 10 surviving microfilaremic individuals became negative gradually over the first 6 years and no new microfilaremia was found. Since then, the microfilarial rate was zero. During the 8 years, 19 vector mosquitos were positive, with a total of 33 filarial larva. Culex pipiens pallens was the predominant mosquito species inside human dwelling in all sites. The man-biting rate of mosquitos for outdoor sleepers fluctuated greatly, the highest was 360.60 mosquitos per man per night and the lowest 7.20. The man-biting rate of mosquitos for sleepers inside mosquito-nets was approximately 1. The proportion of multiparous mosquitos also fluctuated greatly, the highest was 88.10% and the lowest 27.27%. According to the data described above, the man-biting rate of mosquitos which contained filaria L3 was less than 1 mosquito per man per transmission season. It is suggested that after the microfilarial rate was lower than 1%, the surviving microfilaremias became negative gradually in 3-5 years, and the transmission of the disease was blocked. Therefore, in the districts where filariasis was basically controlled, elimination of the disease was attainable.

Primary health care: the basis for malaria control in Hubei, China.

By 1992 malaria morbidity in Hubei, China had decreased steadily to its lowest level since 1970. Much of this achievement was through an integration of the primary health services with malaria control activities. However, in some areas malaria has been unstable due to weaknesses in the three tier health network. This has particularly been at the township and village level. The future of village doctors and appropriate measures of malaria control at the village levels are threatened by the change to a market economy. As part of the provincial health program, primary care services need to be improved in service provision, service organization and service quality.