​​​​​ANALYSIS OF POSTNATAL ANGIOGENESIS IN RAT SPINAL CORD

During the early postnatal development, spinal cord undergoes rapid growth, requiring coordinated adaptation of the vascular network. The increased metabolic demands associated with the postnatal growth should activate proangiogenic signaling, predominantly mediated by the Vascular endothelial growth factor (VEGF) pathway. In this study, we profiled the dynamics of VEGF receptor 2 (VEGFR2) expression in the developing rat spinal cord at postnatal day 8 (P8), 15, 21, 29, and 90 using RT-qPCR, Western blotting, and immunofluorescencent analyses. Our results show that amount of VEGFR2 tends to increase during the early postnatal life, as Vegfr2 mRNA levels rise rapidly after birth, culminating around the first postnatal week, and decrease until adulthood. The Western blot analysis also proved that amount of proangiogenic VEGFR2 exhibited an early postnatal peak approximately within 2 weeks after the birth continuously decreasing at later stages of postnatal development. Immunofluorescence showed intense VEGFR2 staining in spinal cord vasculature during the neonatal stages, reflecting the ongoing angiogenesis at this time. According to our results, the pattern of VEGFR2 expression parallels rapid tissue growth after birth, supporting its role in vascular expansion, potentially regulated by hypoxia-associated signaling during postnatal spinal cord development. The research was supported by Slovak Research and Development Agency under the contract No. APVV-23-0274