Non-targeted Metabonomics Study On Congenital Microtia Based Ear Cartilage And Investigation Of Environmental Risk Factors During Pregnancy For Microtia

ObjectiveMicrotia is a major surface malformation that can seriously affect the patients'appearance and mental health.The etiology of microtia is complex and not yet clear.It is very important to study the pathogenic factors and pathogenesis of microtia,and it cannot be neglected in the early intervention of the disease.This research mainly focuses on the external environment stimulation contribution to the body of microtia.This research has the following two aspects:one is the investigation based on surrounding environmental exposure factors during pregnancy,we studied whether there is a difference between these risk factors and different type of microtia.The other is based on metabonomics study of ear cartilage tissue,we tried to find the different metabolites and variational metabolic pathways on molecular level.This is a new perspective to explore the pathogenesis of microtia.Methods1.From September,2017 to February,2018,the patients who visited our hospital were the subjects of the study,and 63 patients were enrolled according to the inclusion exclusion criteria.The questionnaire was designed in combination with risk factors that summarized from literature and clinical findings.The questionnaire including the general information of patient,the circumstances of living environment,living habits of patient's father and living habits of patient's mother.All of the items based on the condition of the patient's mother during pregnancy.After all the data collected,we imported all the data to SPSS20.0 statistical software to analyze.2.Patients with microtia were collected from June 2017 to January 2018 in the hospital-based study.At the same time,patients with normal ear cartilage who performed the surgical treatment(normal treatment process including taking ear cartilage)were collected as the contrast group.During operation,the ear cartilage tissues of the two groups were collected and labeled,and the case group was residual ear cartilage tissue of the patients with microtia,with 18 cases.The control group was normal ear cartilage tissue,total 18 cases.After the sample pretreatment,we used GC-TOFMS(gas chromatography time-of-flight mass spectrometry)of metabonomics.Then we used software of XploreMET to analyze data by multi-dimensional and single-dimensional to screen and find different metabolites and their metabolic pathway.Results1.Divided patients into three groups according to the degree of deformity:the type ?,18 cases(11 male 11 and 7 female);type ?,39 cases(27 male and 12 female);type ?,6 cases(4male and 2 female).The results of single factor analysis showing that there is no difference influence between environment pollution,air quality,condition of dust and home decoration)and different types of microtia,p values>0.05.There was no difference in the effect of smoking,drinking or drinking tea of their fathers during pregnancy on the different types of microtia,and the p value of>0.05.There was no difference in the effect of environmental risk factors between mothers' living habit(eating habits,tea,alcohol,dust,pet contact,active or passive smoking)for different types,microtia,and the p value of>0.05.2.Divided patients into two groups according to residual ear cartilage,I type as a group,type ? and ? as another group.Using binary logistics regression analyze the binary variables.Data analysis results show that it is statistically significant between the influence of habitat environment pollution and different degree of microtia,the p value was less than 0.05,exp(B)value of 0.531,shows that pollution of the environment is one of the risk factors.3.In the study of GC-TOFMS metabolomics based on cartilage tissue,there were 18 cases in the case group(microtia of the ear cartilage),among which 8 cases were male and 11 were from the right ear.18 cases in the control group(normal ear cartilage tissue),among which 11 were males,11 cases from the right ear.According to the multidimensional statistical analysis,it is different in the metabolites of ear cartilage in the two groups.According to the verification of single dimensional statistical analysis,26 specific biomarkers were found.14 of 26 were statistically significant differences,and their p value was less than 0.05.According to the metabolic pathway enrichment analysis(MPEA),five metabolic pathways may change including Arginine metabolism,taurine and the Taurine metabolism,Pantothenate and CoA metabolism,beta-Alanine metabolism,Glycerophospholipid metabolism.Among them,the first three pathways were significantly statistically,p value<0.05.Conclusion1.This study conclude that there is no different between the environmental exposure factors during pregnancy and different classification of microtia.Namely,although the environment risk factors have effect on microtia,but abnormal severity isnot related with exposure to some environmental factors.This should increase the sample size for further verification.2.From this study which is based on ear cartilage of non-targeted metabolomic research successfully screened out the specific biomarkers and abnormal metabolic pathways.And we found Arginine,Taurine,L-Cysteine and Pantothenic acid may have an association with microtia,which proved that it is feasible to study the pathogenesis of microtia from molecular level.