Study On The Changes Of Serotonin And Dopamine During The Process Of Different Umbilical Snails Infected With Schistosome

Background:Schistosomiasis mansoni is a kind of schistosomiasis which is a debilitating disease affecting millions of people in the world,with the highest burden of morbidity and mortality in African countries.The intermediate hosts for the transmission of Sshistosoma mansoni infection are Biomphalaria species,including B.glabrata,B.alexandrina and B.straminea.Biomphalaria species are gastropods belonging to the class of Gastropoda,mainly distributed in Africa,Latin America and the Middle East.The first discovery of the distribution of Biomphalaria snails in Hong Kong,China was in 1974[1],and the snails have spread around the rivers and surrounding areas in ShenZhen[2,3].Studies have shown that,during infection of Biomphalaria,the host can stimulate the induction of a variety of physiological changes,such as spawnin1[4-6],feeding[7],stress evasiou[6],etc,In addition,ehe gene chip has shown a significant difference in the expression of the precursors of serotonin,dopamine and histamine involved in metabolism,when the host snails are infected with S.mansoni[8].Therefore,this study aims to investigate the quantitative expression of the neurotransmitters(biaminoamines)of Biomphalaria with different susceptibilities to schistosomiasis in the nervous system during infection,in order to vunderstand the process of changes in the regulation of neurotransmitters.It is expected that the monoamine transmitters may provide the basis for the regulatory mechanism of Biomphalaria infection with Schistosoma,thus strengthening existing strategies for the control of S.mansoni and its intermediate hosts.Methods:Firstly,different species of Biomphalaria snail samples were obtained using laboratory acclimation methods,then,anatomical studies on central nervous system of Biomphalaria species were performed.After that,an ultra-high performance liquid chromatography-triple quadrupole mass spectrometry(UPLC MS/MS)method was used to quantitatively detecting the serotonin and dopamine from different Biomphalaria central nervous systems(CNS).The biogenic amine levels of serotonin and dopamine in the CNS of Biomphalaria snails such as B.alexandrina,B.glabrata M-line,B.glabrata BS-90 and B.straminea,as well as different susceptibilities were compared by UPLC MS/MS with S.mansoni infection.Among them,the results of the cercariae escape on the 28th day of the infection experiment showed that the Biomphalaria M-line was a Schistosoma mansoni-sensitve strain and the Biomphalaria BS-90 was a Schistosoma mansoni-insensitive strain.Results and Discussion:1)Serotonin in CNS of B.glabrata M-line and B.glabrata(WX)has increased until the 7th day after infection with S.mansoni,but has decreased significantly from the 7th to 14th day.After infection of Schistosoma with B.straminea,the concentration of serotonin increased on days 0-7,and continued to decline on days 7-28,and at 28 to 35 days,the level returned to a higher level.Following infection of B.glabrata BS-90 with Schistosoma,the concentration of serotonin has shown an upward trend on the 0-7th day,and a downward trend after 7 days.On the 14-28th day,there was a pick-up and the concentration decreased again after the 28th day.B.alexandrina spp.have shown a continuous increase of serotonin from 0 to 21 days after infection,and have shown later a decreasing trend on days 21-35.2)The concentration of dopamine in B.glabrata M-line and B.glabrata(WX)have increased at 0-1 days after infection with Schistosoma and have decreased at days 1-14.Thereafter,the level continued to rise to reach a higher level on the 21St day and then showed a downward trend again.The infection of B.straminea with Schistosoma has showed two small peaks of dopamine concentration on the first and 14th day,and thereafter rose again to the highest level from the 28th to 35th day.The concentration of dopamine in infected B.glabrata BS-90 compared to that of infected B.straminea at the 21st day was significantly higher than pre-infection observed in 35 days.The dopamine level of B.alexandrina spp.showed similar trends to that of B.straminea on days 0-28,and continued to decline on days 28-35.The concentrations of serotonin and dopamine in the nervous system of different susceptibilities of Biomphalaria snails have showed changes in content at different times after infection with Schistosoma,suggesting that serotonin and dopamine are involved in the invasion of Schistosoma in the Biomphalaria nerve system when the host is infected with spurring snails.There were significant differences in the changes of serotonin and dopamine contents between susceptible and unsusceptible strains.It was suggested that the important inhibitors in the transformation of hairpin to cytosine in host snails were serotonin and dopamine.That may also inhibit the development and escape of the cercaria.At the same time,according to the changes of two biogenic amines after infection with S.mansoni compared with the susceptibility and susceptible strains of Biomphalaria snails,it belongs to the predominantly susceptible strains.However,the unsusceptible characteristics or mechanism differed from the mechanism of the unsusceptible strains ofBiomphalaria snails.In contrast,B.glabrata(WX)snails were consistent with susceptible strains and were presumed to be susceptible strains 28 days after the end of a stern escape.Conclusion:Combining the relationship between biogenic amines such as serotonin and dopamine and the susceptibility,it was hypothesized that biogenic amines may be the biomarker target for susceptibility to schistosomiasis.More so,according to the differences in the time of infection,the concentration of dopamine is high,and may be more suitable as a biomarker target than serotonin.