Effects Of Cryopreservation On Glycocalyx Of Human Sperm

Human sperm cryopreservation is a vital technology of Human Sperm Bank and human assisted reproductive technology(ART),the leval of cryopreservation technology and recovery will directly affect final pregnancy.However,the sperm viability,motility decreased,DNA integrity,membrane composition,protein composition,density of the mitochondrial matrix and others have undergone varying degrees of damage,what's more,the cervical mucus penetration,the ability to wear egg and the other fertility significantly have decreased after cryopreservation and recovery.It covers with a layer of the glycocalyx on sperm surface.When sperms generate from testis,pass though epididymis,various sugar residues covalent bonding to proteins or lipids of spermatozoa membrane surface,then glycocalyx formats.Sperm glycocalyx is the main interface with external environment and plays a vital role of sperm protection,penetration of cervical mucus,egg recognition and binding.Damage of sperm glycocalyx may result in reduced fertility or even sterility.In the past,due to the technical limitations and complexity of sperm glycocalyx,changes of human sperm glycocalyx after cryopreservation and recovery havn't been reported.This research used fresh and frozen-thawed sperm to establish a model of frozen-thawed damage.At first,compare recovery rate of sperm after frozen-thawed with ORIGIO,Quinn and prepared cryoprotectant,ORIGIO is the best.Then,compare recovery rate of sperm after frozen-thawed with manual cooling method,programmed cooling method and direct fumigation,direct fumigation is better than others.Thus,we establish the model of frozen-thawed damage with ORIGIO cryoprotectant and direct fumigation.Then,SNR values of 35 kinds of lectins have changed after cryopreservation by novel lectin microarray and established technology to detecte human sperm.From lectin binding spectrum of fresh and frozen-thawed sperm,SNR value of 9 lectins was down-regulation and SNR value of 26 lectins was up-regulation.Four up-regulation lectins(ABA?AIA?UEA I and PSA)and two down-regulation lectins(MAA and DSL)were verified by flow cytometry,ABA?AIA?PSA and MAA have positive result with lectin microarray.This can evaluate whether hormone cryopreservation mediums and freeze-thaw methods good or not and provide assessment to optimize freezing-thawing conditions for Human Sperm Bank and assisted reproductive center.On the other hand,binding between ABA and intolerance was decreased significantly than tolerance by lectin binding spectrum of tolerance and intolerance sperm.The result was verified by large sample.Thus,ABA can be potential biological markers to evaluate sperm freeze resistance and provide a new evaluation index for assessment of sperm quality and cryopresevation.