Evaluation Of The Impact Of Preimplantation Genetic Diagnosis Procedures Using Mouse Model On The Cold Stress Response In The Offspring

More than two decades after the first clinical application,preimplantation genetic diagnosis(PGD)is an established medical procedure for patients at high risk of transmitting a genetic disorder to their offspring.PGD is an important aspect of assisted reproduction technology(ART).The routine PGD procedures,including ovarian hyperstimulation,in vitro culture,embryo transfer,and blastomere biopsy,the unique,more invasive manipulation.However,there is still a shortage of proof to convince that these manipulations there is no potential risk to the development of the offspring.The life processes would be impacted by the internal and external environmental changes.When the organisms are challenged by stressors,all systems and organs must common to maintain the body's normal steady state.Therefore,body's reactive and regulation ability is one of the important factors to ensure their normal development and function.To investigate the reaction of PGD outcomes for stimulus such as environmental change,we constructed the PGD mouse model,and the naturally conceived mouse was served as control.Using the morphological,molecular biological,immunological methods,we evaluated the 5-week-old mice on the hypothalamic-pituitary-adrenal(HPA)axis and locus coeruleus-sympathetic-adrenal medulla(LC/NE)axis,the two main reaction paths of the stress response,and did the following investigations:(1)Detection of the stress-related central and peripheral organs' structure and function,and the serum hormone levels at the basic state.As the results shown,the central organs' structure and function of PGD conceived mice didn't change significantly.But in the PGD group,there were some abnormal ultrastructure in the adrenal gland(The mitochondria in the fascicular zone cells of the adrenal cortex had blurry,loosely packed cristae.The secretory granules of medulla adrenaline cells with comparatively lager vacuoles indicated it was in the secretory phase.);the expression of P450scc which was the key gene of the glucocorticoids synthesis was lower;the serum level of corticosterone was lower and epinephrine was higher.These results indicated that there were some abnormal during the development of adrenal glands of PGD conceived mice.(2)Cold stress was served as the stimulus,and then we investigated the stress-related central and peripheral organs' structure and function,and the serum hormone levels after the cold stress.The results shown that the response of PGD group in the cold stress was significant different from Normal group.The central organs' structure and function of PGD group wasn't observed significant abnormality.However,in the PGD group,the abnormal ultrastructure of the adrenal galnd still existed(In the fascicular zone cells of the adrenal cortex,the mitochondria cristae still blurry,and packed more loosely.);the expression of genes involved in glucocorticoids synthesis were no significant differences but shown a lower tendency;the serum level of corticosterone was still lower.All the results suggested that the adrenal of the PGD outcomes were abnormal development,the function of the adrenal to secret corticosterone cannot be educed well.PGD conceived mice appeared different response to the cold stress,one of the reasons may be the reduced secretion of corticosterone.In general,we found the manipulations involved in the PGD would probably bring some impact to the offspring.There were some abnormality exist in the adrenal of PGD outcomes,which leaded to the secretory disorders of relative hormones.And the abnormal secretion of glucocorticoids after acute cold stress would made the PGD conceived mice appear to a significant different response compare with the normal conceived controls.For the PGD outcomes,further studies will assess the possibility of serious pathological changes in the later phase of development.And the mechanism of the adrenal developmental abnormalities which was caused by PGD procedures need to further explore.Meanwhile,it will require more extensive evaluations to ensure the security of the application of ART.