2.Molecular cloning and characterization of a novel aspartyl aminopeptidase from Trichinella spiralis
Sun, X.Y. ; Ma, K.N. ; Bai, Y. ; Liu, R.D. ; Long, S.R. ; Zhang, X. ; Jiang, P. ; Cui, J. ; Wang, Z.Q.
Tropical Biomedicine 2021;38(No.3):420-434
Trichinellosis is an important zoonotic parasitic disease worldwide and is principally caused by ingesting animal meat containing Trichinella infective larvae. Aspartyl aminopeptidase is an intracytoplasmic metalloproteinase that specifically hydrolyzes the N-terminus of polypeptides free of acidic amino acids (aspartic acid and glutamate), and plays an important role in the metabolism, growth and development of organisms. In this study, a novel T. spiralis aspartyl aminopeptidase (TsAAP) was cloned and expressed, and its biological properties and roles in worm growth and development were investigated. The results revealed that TsAAP transcription and expression in diverse T. spiralis stages were detected by RT-PCR and Western blotting, and primarily localized at cuticle, stichosome and intrauterine embryos of this nematode by immunofluorescence test. rTsAAP has the enzymatic activity of native AAP to hydrolyze the substrate H-Glu-pNA. There was a specific binding between rTsAAP and murine erythrocyte, and the binding site was localized in erythrocyte membrane proteins. Silencing of TsAAP gene by specific dsRNA significantly reduced the TsAAP expression, enzymatic activity, intestinal worm burdens and female fecundity. The results demonstrated that TsAAP participates in the growth, development and fecundity of T. spiralis and it might be a potential target molecule for anti-Trichinella vaccines.
3.Trichinella spiralis: RNAi-mediated silencing of serine protease results in reduction of intrusion, development and fecundity
Yang, D.Q. ; Zeng, J. ; Sun, X.Y. ; Yue, X. ; Hu, C.X. ; Jiang, P. ; Liu, R.D. ; Cui, J. ; Wang, Z.Q.
Tropical Biomedicine 2020;37(No.4):932-946
In previous studies, a Trichinella spiralis serine protease (TsSP) was identified in
excretion/secretion (ES) products from intestinal infective L1 larvae (IIL1) using
immunoproteomics. The complete cDNA sequence of TsSP gene was 1372 bp, which encoded
429 amino acids with 47.55 kDa. The TsSP was transcribed and expressed at all T. spiralis life
cycle phases, as well as mainly located at the cuticle and stichosome of the parasitic nematode.
Recombinant TsSP bind to intestinal epithelial cells (IEC) and promoted larva invasion, however,
its exact function in invasion, development and reproduction are still unknown. The aim of
this study was to confirm the biological function of TsSP during T. spiralis invasion and
growth using RNA interference (RNAi) technology. The results showed that on 1 day after
electroporation using 2.5 µM siRNA156, TsSP mRNA and protein expression of muscle larvae
(ML) was suppressed by 48.35 and 59.98%, respectively. Meanwhile, silencing of TsSP gene
by RNAi resulted in a 61.38% decrease of serine protease activity of ML ES proteins, and a
significant reduction of the in vitro and in vivo invasive capacity of IIL1 to intrude into the
IEC monolayer and intestinal mucosa. When mice were infected with siRNA 156-transfected
larvae, adult worm and muscle larva burdens were decreased by 58.85 and 60.48%,
respectively. Moreover, intestinal worm growth and female fecundity were evidently inhibited
after TsSP gene was knockdown, it was demonstrated that intestinal adults became smaller
and the in vitro newborn larval yield of females obviously declined compared with the
control siRNA group. The results indicated that knockdown of TsSP gene by RNAi significantly
reduced the TsSP expression and enzymatic activity, impaired larvae intrusion and growth,
and lowered the female reproductive capacity, further verified that TsSP might participate in
diverse processes of T. spiralis life cycle, it will be a new prospective candidate molecular
target of anti-Trichinella vaccines.
4.Global genetic diversity of Spirometra tapeworms
Hong, X. ; Liu, S.N. ; Xu, F.F. ; Han, L.L. ; Jiang, P. ; Wang, Z.Q. ; Cui, J. ; Zhang, X.
Tropical Biomedicine 2020;37(No.1):237-250
Spirometra larvae are etiological agents of human sparganosis. However, the systematics of spirometrid cestodes has long been controversial. In order to determine the current knowledge on the evolution and genetic structure of Spirometra, an exhaustive population diversity analysis of spirometrid cestodes using the mitochondrial gene: cytochrome c oxidase subunit 1 (cox1) was performed. All publicly available cox1 sequences available in the GenBank and 127 new sequencing genes from China were used as the dataset. The haplotype identify, network, genetic differentiation and phylogenetic analysis were conducted successively. A total of 488 sequences from 20 host species, representing four spirometrid tapeworms (S. decipiens, S. ranarum, S. erinaceieuropaei and Sparganum proliferum) and several unclassified American and African isolates from 113 geographical locations in 17 countries, identified 45 haplotypes. The genetic analysis revealed that there are four clades of spirometrid cestodes: Clade 1 (Brazil + USA) and Clade 2 (Argentina + Venezuela) included isolates from America, Clade 3 contained African isolates and one Korean sample, and the remainders from Asia and Australia belonged to Clade 4; unclassified Spirometra from America and Africa should be considered the separate species within the genus; and the taxonomy of two Korea isolates (S. erinaceieuropaei KJ599680 and S. decipiens KJ599679) was still ambiguous and needs to be further identified. In addition, the demographical analyses supported population expansion for the total spirometrid population. In summary, four lineages were found in the spirometrid tapeworm, and further investigation with deeper sampling is needed to elucidate the population structure.
5.Functional analysis of Trichinella spiralis serine protease 1.2 by siRNA mediated RNA interference
Yang, F. ; Guo, K.X. ; Yang, D.Q. ; Long, S.R. ; Zhang, X. ; Jiang, P ; Cui, J. ; Wang, Z.Q. ; Liu, R.D.
Tropical Biomedicine 2020;37(No.2):458-470
A T. spiralis serine protease 1.2 (TsSP1.2) was identified in the muscle larvae (ML) and intestinal larvae surface/excretory–secretory (ES) proteins by immunoproteomics. The aim of this study was to determine the TsSP1.2 function in the process of T. spiralis intrusion, growth and reproduction by using RNA interference (RNAi). RNAi was used to silence the expression of TsSP1.2 mRNA and protein in the nematode. On 2 days after the ML were electroporated with 2 µM of TsSP1.2-specific siRNA 534, TsSP1.2 mRNA and protein expression declined in 56.44 and 84.48%, respectively, compared with untreated ML. Although TsSP1.2 silencing did not impair worm viability, larval intrusion of intestinal epithelium cells (IEC) was suppressed by 57.18% (P < 0.01) and the suppression was siRNA-dose dependent (r = 0.976). Infection of mice with siRNA 534 transfected ML produced a 57.16% reduction of enteral adult burden and 71.46% reduction of muscle larva burden (P < 0.05). Moreover, silencing of TsSP1.2 gene in ML resulted in worm development impediment and reduction of female fertility. The results showed that silencing of TsSP1.2 by RNAi inhibited larval intrusion and development, and reduced female fecundity. TsSP1.2 plays a crucial role for worm invasion and development in T. spiralis life cycle, and is a potential vaccine/drug target against Trichinella infection.
6.Primary assessment of a T. spiralis putative serine protease for early serological detection of experimental trichinellosis
Sun, G.G. ; Lei, J.J. ; Guo, K.X. ; Liu, R.D. ; Long, S.R. ; Zhang, X. ; Jiang, P. ; Cui, J. ; Wang, Z.Q.
Tropical Biomedicine 2019;36(3):792-802
A putative serine protease of T. spiralis (TsSP) was expressed in Escherichia coli
and its potential as a diagnostic antigen was primarily assessed in this study. Anti-Trichinella
IgG in serum samples from T. spiralis different animal hosts (mice, rats, pigs and rabbits)
were detected on Western blot analysis with rTsSP. Anti-Trichinella antibodies were detected
in 100% (30/30) of experimentally infected mice by rTsSP-ELISA. Cross-reactions of rTsSPELISA
were not found with sera from mice infected with other parasites (S. erinaceieuropaei,
S. japonicum, C. sinensis, A. cantonensis and T. gondii) and sera from normal mice. There
was no statistical difference in antibody detection rate among mice infected with the
encapsulated Trichinella species (T. spiralis, T. nativa, T. britovi, and T. nelsoni) (P>0.05).
The results of rTsSP-ELISA showed that serum specific antibody IgG in mice infected with
100 or 500 T. spiralis muscle larvae (ML) were detectable early at 7-8 dpi, but not detected
by ML ES antigen-ELISA prior to 10-12 dpi. Specific anti-Trichinella IgG was detected in 100%
(18/18) of infected pigs by rTsSP-ELISA and ES-ELISA, but no specific antibodies was not
detected in 20 conventionally raised normal pigs by two antigens. The results showed the
rTsSP had the potential for early serodiagnosis of animal Trichinella infection, however it
requires to be assayed with early infection sera of swine infected with Trichinella and other
parasites.
7.Disease burden of diabetes attributable to high body mass index in China,1990-2016.
Y Y JIANG ; M LIU ; N JI ; X Y ZENG ; W L DONG ; F MAO ; S W LIU ; J Q DONG ; M G ZHOU
Chinese Journal of Epidemiology 2019;40(1):46-51
Objective: To analyze the burden of disease (BOD) on diabetes attributable to high BMI in China from 1990 to 2016. Methods: Data based on population of the 2016 Global Burden of Disease Study for China were used to analyze the attributable fractions (PAF) of BOD for diabetes attributable to high BMI. Measurements for attributable BOD of diabetes included disability adjusted life years (DALY), years of lost life (YLL), years living with disability (YLD), death number and mortality rate. The average world population from 2010 to 2035 was used as a reference. Results: In 2016, death number of diabetes attributable to high BMI was 40 310, which was significantly higher than that in 1990 (15 008). Age-standardized death rate of diabetes attributable to high BMI increased from 2.01/100 000 in 1990 to 2.60/100 000 in 2016, which showed a more significant increasing trend in both males and people aged 15-49 years. DALYs of diabetes attributable to high BMI increased from 1.09 million person years to 3.30 million person years. YLL and YLD also showed increasing trends. The highest increasing rate of YLD was in people aged 15-49 years. High BMI was responsible for 26.01% of the diabetes deaths in 2016 in China, an increase of 39.39% compared with that in 1990 (18.66%). Most provinces in China experienced a sharp increase of DALY of diabetes attributable to high BMI from 1990 to 2016. Inner Mongolia, Xinjiang, Zhejiang, Macao SAR, Sichuan and Qinghai had the most significant increase tendency in terms of DALY rate during this period. Conclusions: There was a rapid increase of the deaths and mortality rate of diabetes attributable to high BMI, causing a heavy disease burden, in China from 1990 to 2016. The BOD varied in both different age and gender groups. More attention should be paid to males and people aged 15-49 years in the prevention and control programs of diabetes.
Adolescent
;
Adult
;
Body Mass Index
;
China/epidemiology*
;
Cost of Illness
;
Diabetes Mellitus/ethnology*
;
Disabled Persons
;
Humans
;
Macau
;
Male
;
Middle Aged
;
Quality-Adjusted Life Years
;
Sickness Impact Profile
;
Young Adult
8.Epidemiological characteristics of molecular transmission cluster among reported HIV/AIDS cases in Jiaxing city, Zhejiang province, 2017.
M Y LUO ; X H PAN ; Q FAN ; J F ZHANG ; R GE ; J JIANG ; W J CHEN
Chinese Journal of Epidemiology 2019;40(2):202-206
Objective: To understand the epidemiological characteristics of one large HIV molecular transmission cluster in Jiaxing city, Zhejiang province, 2017 in order to select those people under high-risk and providing basis for programs on prevention. Methods: During 2017, newly diagnosed HIV/AIDS cases in this city were recruited. Plasma samples were collected from subjects, followed by RNA extraction, RT-PCR and nest-PCR for pol gene amplification, before being sequenced and aligned. Mega 6.0 software was used to construct phylogenetic tree, and Cytoscape 3.6.0 software was used to identify HIV molecular transmission clusters. Cases within the large transmission clusters were investigated, using a field-epidemiology-questionnaire. Data related to socio-demographics and previous sexual behaviors were collected and EpiData 3.0 and SPSS 20.0 software were used. Results: In the large transmission cluster with subtype identified as CRF07_BC, in Jiaxing, 2017, 26 cases of the total 30 cases were investigated. A total of 80.8% (21/26) could be identified as newly infected within the last two years and 30.8%(8/26) could be identified as newly infected within the last one year, including 22 cases infected locally. Among several infected cases who were at age 45 years or older, they admitted that they had experienced unprotected sexual contacts in local city for long time and having had more than 10 disclosed sexual contacts within the last two years at the local venues. Conclusions: This molecular cluster had been formed and scaled up quickly in recent two years, it has played an important role in promoting and scaling up the HIV transmission. Three cases identificed as high risk played an importantrde role in scaling up this cluster.
Amplified Fragment Length Polymorphism Analysis
;
China/epidemiology*
;
Genes, pol
;
Genotype
;
HIV Infections/transmission*
;
HIV-1/isolation & purification*
;
Humans
;
Molecular Epidemiology
;
Phylogeny
;
Polymerase Chain Reaction
;
RNA, Viral/blood*
;
Sexual Behavior
;
pol Gene Products, Human Immunodeficiency Virus
9.Study on early warning threshold values for 7 common communicable diseases in Gansu province, 2016.
Y CHENG ; X F LIU ; L MENG ; X T YANG ; D P LIU ; K F WEI ; X J JIANG ; H X LIU ; Y H ZHENG
Chinese Journal of Epidemiology 2018;39(3):352-356
Objective: To optimize the warning threshold values of common communicable diseases in Gansu province, and improve the early warning effect. Method: An early warning model was set up for influenza, scarlet fever, other infectious diarrheal diseases, dysentery, typhoid and paratyphoid, viral hepatitis type E and hand foot and mouth disease (HFMD) respectively in Gansu by using the moving percentile method and cumulative sum method. By calculating the sensitivity, specificity, predictive value of positive test, predictive value of negative test, Youden' index and receiver-operating characteristic curve, the optimum early warning threshold values for communicable diseases in Gansu were selected. Results: The optimum early warning boundary values of influenza, scarlet fever, other infectious diarrheal diseases, dysentery, typhoid and paratyphoid, and viral hepatitis type E were P(90), P(80), P(95), P(90), P(80) and P(90) respectively. The optimum early warning parameters of HFMD were k=1.2, H=5σ. Under the optimum early warning boundary values/parameters, the early warning sensitivities of influenza, scarlet fever, other infectious diarrheal diseases, dysentery, typhoid and paratyphoid, viral hepatitis type E and HFMD were 86.67%, 100.00%, 91.67%, 100.00%, 100.00%, 100.00% and 100.00%, the specificities were 86.49%, 62.22%, 75.00%, 100.00%, 97.92%, 89.13% and 74.47%. The predictive values of positive test were 72.22%, 29.17%, 52.38%, 100.00%, 80.00%, 54.55% and 29.41%, and the predictive values of negative test were 94.12%, 100.00%, 96.77%, 100.00%, 100.00%, 100.00% and 100.00%, and the Youden' indexes were 0.73, 0.62, 0.67, 1.00, 0.98,0.89 and 0.74. Receiver-operating characteristic curve showed that the values/parameters of this warning boundary were the points closest to the upper left of the coordinate diagram. Conclusion: The early warning thresholds of influenza, other infectious diarrheal diseases, dysentery and hepatitis E in Gansu may be raised appropriately and the early warning parameters of HFMD need to be adjusted to improve the effectiveness of early warning.
China
;
Communicable Disease Control/methods*
;
Communicable Diseases/epidemiology*
;
Disease Notification
;
Disease Outbreaks/prevention & control*
;
Humans
;
Models, Theoretical
;
Population Surveillance/methods*
10.Effect of health literacy and exercise-focused interventions on glycemic control in patients with type 2 diabetes in China.
X N LIU ; Q H XIA ; H FANG ; R LI ; Y Y CHEN ; Y J YAN ; P ZHOU ; B D YAO ; Y JIANG ; W G ROTHMAN ; Wanghong XU
Chinese Journal of Epidemiology 2018;39(3):357-362
Objective: To evaluate the effect of health literacy and exercise-focused interventions on glycemic control in patients with type 2 diabetes (T2DM) in China. Methods: In this cluster randomized controlled trial, a total of 799 T2DM patients with most recent hemoglobin A1c (HbA1c) ≥ 7.5% (or fasting plasma glucose level ≥10 mmol/L) were recruited from 8 communities in Minhang and Changning districts of Shanghai, and randomized into a health literacy intervention group, an exercise intervention group, a comprehensive intervention group and a control group. After baseline survey and examination, a one-year intervention and 3 times (at 3(rd), 6(th), and 12(th) month) follow-up surveys were conducted. Results: The follow-up rates for all the subjects were 99.4%, 98.4% and 95.2%, respectively, at 3(rd), 6(th) and 12(th) month. Patients in intervention groups were more likely to achieve a goal HbA1c level (HbA1c <7.0%) than those in control group, with the highest glycemic control rate (25.3%) observed in comprehensive intervention group at 3(rd) month and then in exercise intervention group (25.3% and 34.6%) respectively, at 6(th) month and 12(th) month. The average levels of HbA1c in three intervention groups were lower at each follow-up time point than those at baseline survey. However, the decreases in HbA1c were obvious only at 6(th) month (P<0.001), with ls-mean (95%CI) of -0.48% (-0.71%, -0.25%), -0.33% (-0.55%, -0.11%) and -0.70% (-0.92%, -0.48%), respectively, in comprehensive, health literacy and exercise intervention groups, but it increased slightly by 0.03% (-0.19%, 0.25%) in control group. Compared with control group, the interventions were significantly associated with the decrease of HbA1c level, with the most improvement observed in comprehensive group (β=-0.47, 95% CI: -0.73, -0.20) at 3(rd) month, and in exercise intervention group at 6(th) month (β=-0.73, 95%CI: -0.98, -0.47) and at 12(th) month (β=-0.75, 95%CI: -1.05, -0.45) of follow-up. Stratified analyses showed that patients with lower health literacy level could benefit from any intervention, while those with higher numeracy skill benefited more from exercise intervention. Conclusion: Both health literacy and exercise-focused interventions may decrease HbA1c level in patients with T2DM, which would be helpful in reducing the risks of complications and deaths in diabetes patients.
Blood Glucose/analysis*
;
China
;
Diabetes Mellitus, Type 2/therapy*
;
Disease Management
;
Exercise
;
Follow-Up Studies
;
Glycated Hemoglobin/analysis*
;
Health Literacy
;
Humans
;
Patient Education as Topic
;
Self Care
;
Surveys and Questionnaires
;
Treatment Outcome


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