Key Laboratory of Tropical Disease Control SYSU

Guangzhou, China

Key Laboratory of Tropical Disease Control SYSU

Guangzhou, China
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Song L.,Sun Yat Sen University | Song L.,Key Laboratory of Tropical Disease Control SYSU | Song L.,Provincial Engineering Technology Research Center for Biological Vector Control | Wu X.,Fudan University | And 4 more authors.
Parasitology Research | Year: 2017

Schistosomiasis is a chronic, parasitic disease caused by flukes (trematodes) of the genus Schistosoma, which presents the most important global burden of the 17 neglected tropical diseases listed by the World Health Organization. China has made great achievements in schistosomiasis control, and now China is planning to move forward, to eliminate schistosomiasis within 2020, but the fact cannot be denied that the possibility of schistosome infection is still there in some endemic due to its zoonotic nature as well as wide distribution of its intermediate hosts (snails). Thus, how to interrupt the transmission in areas with distribution of schistosomes and intermediate snails becomes a very serious challenge that China is facing. In this paper, it is reported an advanced schistosomiasis japonica case of a 15-year-old boy which is extremely rare in the current schistosomiasis control in China. Thus, it is supposed to strengthen health education of school children and to train professional physicians of local hospitals. © 2017 Springer-Verlag Berlin Heidelberg


Wang L.,Sun Yat Sen University | Wang L.,Key Laboratory of Tropical Disease Control SYSU | Wang L.,Provincial Engineering Technology Research Center for Biological Vector Control | Xie H.,Sun Yat Sen University | And 27 more authors.
Theranostics | Year: 2017

Background: Epidemiologic studies and animal model experiments have shown that parasites have significant modulatory effects on autoimmune disorders, including inflammatory bowel disease (IBD). Recombinant Sj16 (rSj16), a 16-kDa secreted protein of Schistosoma japonicum (S.japonicum) produced by Escherichia coli (E. coli), has been shown to have immunoregulatory effects in vivo and in vitro. In this study, we aimed to determine the effects of rSj16 on dextran sulfate sodium (DSS)-induced colitis. Methods: DSS-induced colitis mice were treated with rSj16. Body weight loss, disease activity index (DAI), myeloperoxidase (MPO) activity levels, colon lengths, macroscopic scores, histopathology findings, inflammatory cytokine levels and regulatory T cell (Treg) subset levels were examined. Moreover, the differential genes expression after treated with rSj16 were sequenced, analyzed and identified. Results: rSj16 attenuated clinical activity of DSS-induced colitis mice, diminished pro-inflammatory cytokine production, up-regulated immunoregulatory cytokine production and increased Treg percentages in DSS-induced colitis mice. Moreover, DSS-induced colitis mice treated with rSj16 displayed changes in the expression levels of specific genes in the colon and show the crucial role of peroxisome proliferator activated receptor α (PPAR-α) signaling pathway. PPAR-α activation diminished the therapeutic effects of rSj16 in DSS-induced colitis mice, indicating that the PPAR-α signaling pathway plays a crucial role in DSS-induced colitis development. Conclusions: rSj16 has protective effects on DSS-induced colitis, effects mediated mainly by PPAR-α signaling pathway inhibition. The findings of this study suggest that rSj16 may be useful as a therapeutic agent and that PPAR-α may be a new therapeutic target in the treatment of IBD. © Ivyspring International Publisher.


Zeng X.,Chinese University of Hong Kong | Zeng X.,Sun Yat Sen University | Zeng X.,Key Laboratory of Tropical Disease Control SYSU | Yiu W.C.,Chinese University of Hong Kong | And 14 more authors.
Parasites and Vectors | Year: 2017

Background: Schistosomiasis, also generally known as snail fever, is a parasitic disease caused by trematode flatworms of the genus Schistosoma. In Hong Kong and mainland China, the freshwater snail Biomphalaria straminea has been introduced and has the potential to transmit intestinal schistosomiasis caused by S. mansoni, a parasite of man which has a wide distribution in Africa and parts of the New World, especially Brazil. The first identification of B. straminea in Hong Kong dates back to the 1970s, and its geographical distribution, phylogenetic relationships, and infection status have not been updated for more than 30 years. Thus, this study aims to reveal the distribution and current infection status of B. straminea in contemporary Hong Kong. Methods: Snails were collected from different parts of Hong Kong from July 2016 to January 2017. Both anatomical and molecular methods were applied to identify B. straminea. Cytochrome c oxidase subunit 1 (cox1), internal transcribed spacer 1 (ITS1), 5.8S rDNA, internal transcribed spacer 2 (ITS2), and 16S ribosomal DNA (rDNA) were sequenced from individual snails and analyzed. To detect the presence of S. mansoni, both biopsy and PCR analyses were carried out. Results: Using both anatomical and molecular analyses, this study demonstrated the existence of black- and red-coloured shell B. straminea in different districts in the New Territories in Hong Kong, including places close to the mainland China border. None of the B. straminea (n = 87) investigated were found to be infected with S. mansoni when tested by biopsy and PCR. The Hong Kong B. straminea are genetically indistinguishable, based on the chosen molecular markers (cox1, ITS1-5.8S-ITS2, and 16S rDNA), and are similar to those obtained in mainland China and South America. Conclusion: Biomphalaria straminea is now well established in freshwater habitats in Hong Kong. No evidence of infection with S. mansoni has been found. Surveillance should be continued to monitor and better understand this schistosomiasis intermediate host in mainland China and Hong Kong. © 2017 The Author(s).


Feng Y.,Sun Yat Sen University | Zeng X.,Sun Yat Sen University | Zeng X.,Key Laboratory of Tropical Disease Control SYSU | Li W.-H.,Sun Yat Sen University | And 7 more authors.
Parasitology Research | Year: 2014

Human Angiostrongylus cantonensis (A. cantonensis) is a food-borne parasitic disease and can cause optic neuritis. Increasing clinical angiostrongyliasis cases with optic neuritis have been reported, but the pathogenesis has not been fully understood until now. Here, we applied rats with A. cantonensis infection as an animal model to study the pathogenesis of optic neuritis caused by the infection. We observed that the optic disk of experimental rats appeared hyperemic, the retina vein became thick, and the visual evoked potential (VEP) latency was prolonged. There were obvious inflammatory cell infiltration in the retina and optic nerve adventitia followed with obvious optic nerve fiber demyelination and retina ganglion swelling. We also evaluated the effect of dexamethasone combined with albendazole on optic neuritis of rats infected with A. cantonensis. The results showed it had no obvious effect to prevent progressive visual deterioration for optic neuritis caused by A. cantonensis. The studies provided evidence that the pathogenesis of optic neuritis in infected rats was correlated to optic nerve demyelination and ganglion cell damage caused by optic nerve inflammation, and the common therapy to this disease was not so effective. Based on the above results, it may be necessary to combine neuroprotective agents with common therapy to treat and protect optic nerve and ganglion cells from their secondary injury. © 2014 Springer-Verlag Berlin Heidelberg.


Yu L.,Sun Yat Sen University | Yu L.,Key Laboratory of Tropical Disease Control SYSU | Liao Q.,Ningbo University | Chen X.,Sun Yat Sen University | And 13 more authors.
Parasitology Research | Year: 2014

Increasing evidence shows that microRNAs (miRNAs) are a family of regulatory molecules involved in many physiological processes, including the inflammation in central nervous system (CNS) and neurological disorders. Angiostrongylus cantonensis (A. cantonensis) is the major cause of human infectious eosinophilic meningitis and can induce CNS injury. In the present study, we investigated the expression of miRNAs involved in neuronal functions such as miR-132-3p/212-3p, and miR-146a-5p, inflammation-related miRNA, in the modulation of inflammation of CNS of mice and rats induced by A. cantonensis. The functions of differentially expressed miRNAs were analyzed through bioinformatics methods, and the expression of chosen target genes were investigated by quantitative reverse transcription polymerase chain reaction. The results showed that miR-146a-5p upregulated in the brain of rats after 21 days; A. cantonensis infection and the expression of miR-132-3p and miR-146a-5p upregulated in the brain of mice model infected by A. cantonensis. The expression of the target genes of mmu-miR-146a-5p such as Irak1 and Traf6 downregulated in 14 days and 21 days after A. cantonensis infection. Our results supply more information about the involvement of the miRNAs in the regulation of inflammation of CNS induced by A. cantonensis. © 2013 Springer-Verlag Berlin Heidelberg.


Feng F.,Sun Yat Sen University | Feng F.,Key Laboratory of Tropical Disease Control SYSU | Feng Y.,Sun Yat Sen University | Liu Z.,Sun Yat Sen University | And 7 more authors.
Parasites and Vectors | Year: 2015

Background: Angiostrongylus cantonensis (A. cantonensis) infection can lead to optic neuritis, retinal inflammation, damage to ganglion cells, demyelination of optic nerve and visual impairment. Combined therapy of albendazole and dexamethasone is a common treatment for the disease in the clinic, but it plays no role in vision recovery. Therefore, it has been necessary to explore alternative therapies to treat this disease. Previous studies reported the neuro-productive effects of two constituents of Danshen (a Chinese herb)-tanshinone II-A (TSII-A) and cryptotanshinone (CPT), and this study aims to evaluate the impacts of TSII-A or CPT combined with albendazole on optic neuritis caused by A. cantonensis infection in a murine model. Methods: To assess the effects of TSII-A or CPT combined with albendazole on optic neuritis due to the infection, mice were divided into six groups, including the normal control group, infection group and four treatment groups (albendazole group, albendazole combined with dexamethasone group, albendazole combined with CPT group and albendazole combined with TSII-A group). The infection group and treatment groups were infected with A. cantonensisand the treatment groups received interventions from 14 dpi (days post infection), respectively. At 21 dpi, the visual acuity of mice in each group was examined by visual evoked potential (VEP). The pathologic alteration of the retina and optic nerve were observed by hematoxylin and eosin (H&E) staining and transmission electronic microscopy (TEM). Results: Infection of A. cantonensis caused prolonged VEP latency, obvious inflammatory cell infiltration in the retina, damaged retinal ganglions and retinal swelling, followed by optic nerve fibre demyelination and a decreasing number of axons at 21 dpi. In treatment groups, albendazole could not alleviate the above symptoms; albendazole combined with dexamethasone lessened the inflammation of the retina, but was futile for the other changes; however, albendazole combined with CPT and albendazole combined with TSII-A showed obvious effects on the recovery of prolonged VEP latency, destruction and reduction of ganglion cells, optic nerve demyelination and axon loss. Compared with albendazole-CPT compound, albendazole combined with TSII-A was more effective. Conclusions: The current study demonstrates that albendazole combined with TSII-A plays a more effective role in treating optic neuritis caused by A. cantonensis in mice than with dexamethasone, as applied in conventional treatment, indicating that albendazole combined with TSII-A might be an alternate therapy for this parasitic disease in the clinic. © 2015 Feng et al.


Feng Y.,Sun Yat Sen University | Zeng X.,Sun Yat Sen University | Zeng X.,Key Laboratory of Tropical Disease Control SYSU | Li W.-H.,Sun Yat Sen University | And 9 more authors.
Parasites and Vectors | Year: 2014

Background: One of the most common causes of meningitis in South East Asia is angiostrongyliasis or infection by the parasitic nematode Angiostrongyliasis cantonensis. Although this nematode usually resides in the pulmonary arteries of rats, its incidental occurence in other hosts such as humans can cause optic neuritis and lead to serious vision sequelae. Nevertheless, there are currently no systematic studies conducted in this area. Methods. In order to study the pathogenesis of optic neuritis, mice were tried as a new animal model to study and challenge with A. cantonensis on 7d, 14d and 21d, respectively. Electroretinogram (ERG), visual evoked potential (VEP), ophthalmoscopy and histology were examined on day 7d, 14d and 21d and tribendimidine (TBD) was later used to treat optic neuritis on day 14d for a week to evaluate its therapeutic effects. Results: Infection of A. cantonensis caused obvious inflammatory cell infiltration in the retina and optic nerve adventitia in day 14d and 21d followed by optic nerve fiber demyelination and retinal ganglion swelling at day 21d in the challenged mice. Prolonged VEP latency and decreased ERG amplitude were also observed on day 21. After treatment of TBD in the infected mice, retinal and optic nerve inflammation were alleviated, but VEP latency and ERG amplitude did not improve on day 21d and 28d. Conclusions: The current study provides evidence that A. cantonensis can cause optic neuritis along with optic nerve demyelination and retinal ganglion cell damage in a mouse model. TBD alone treatment can improve the symptoms of optic neuritis, but does not aid in vision recovery, suggesting that both neuroprotective agents and Dexamethasone should be administered, along with treatment for the infection, to protect the optic nerve and ganglion cells. Furthermore, as the symptoms of optic neuritis caused by A. cantonensis in mice are similar to the optic neuritis in multiple sclerosis (MS) human patients, we suggest that the BALB/c mouse model provided in this study may be useful to explore therapies of optic neuritis in MS patients. © 2014 Feng et al.; licensee BioMed Central Ltd.

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