Abstract:

Objective In this study, whole-exome sequencing was used to identify pathogenic mutations in a newborn with cerebral dysplasia. Methods The exome targets of the patient′s DNA was captured with the SureSelct Human All Exon kit followed by sequencing with the Illumina HiSeq2000 platform. The data analysis pipeline of Children′s Hospital of Fudan University was used for the annotation and variant calling. The detected variant was confirmed with Sanger direct sequencing. Neurons were isolated from neonatal rats and the oxygen-glucose deprivation (OGD) model was established. The cultured neurons were divided into 2 control group (Sham+PBS and Sham+POSTN subgroups) and OGD group (OGD+PBS and OGD+POSTN subgroups). Immunofluorescence, LDH cytotoxicity detection, BrdU staining and TUNEL staining were used to detect the proliferation and apoptosis of cultured neurons.Results Whole-exome sequencing identified total of 532 151 variants in the proband, and revealed two novel compound heterozygous variants in exon 23:c.A2475T:p.G825G and exon 19:c.G2251A:p.E751K in POSTN (NM_006475) gene. Sanger direct sequencing confirmed these two variants. POSTN was expressed in the cultured rat neurons (MAP-2 and NeuN positive cells). LDH cytotoxicity in Sham+POSTN subgroup was compromised with Sham+PBS subgroup. However, POSTN protected neurons from LDH cytotoxicity in OGD groups. The neurons were treated with OGD for 2, 6, 12 days, compared with Sham+PBS subgroups, the proliferation of neurons was increased in OGD+PBS subgroup as well as apoptosis of neurons. After POSTN treatment, the number of proliferative neurons was markedly increased in OGD group, however, the apoptotic neuron number was significantly decreased.Conclusion POSTN treatment decreased LDH cytotoxicity, increased the proliferation and decreased apoptosis of OGD-treated neurons.