(P01-013-24) Lutein Extended Astrocyte Networks and Increased the Number of Retinal Neuronal Cells in Neonatal Rats With Retinopathy of Prematurity

Objectives: Retinopathy of prematurity (ROP), an eye condition characterized by the abnormal growth of the retinal blood vessels, affects roughly 32% of hospitalized preterm infants and is a leading cause of blindness among them. Astrocytes are a type of glial cell that contribute to the formation of the blood-retinal barrier and help maintain its integrity by stabilizing tight junctions. Retinal neurons are responsible for vision and have high oxygen requirements. Previous research found that ROP altered the distribution of astrocytes and reduced the numbers of astrocytes and neuronal cells. Lutein, a dietary antioxidant and main component of the macular pigment, may help ameliorate ROP. Thus, the aim of this research was to assess the effect of both free lutein and a biopolymer-based lutein emulsion, which enhanced lutein bioavailability in our previous research, on astrocyte networks and the retinal neurons in neonatal rats with ROP.

Methods: ROP was induced in neonatal Sprague-Dawley rats through an injection of KRN 633, a VEGF receptor inhibitor that prevents normal retinal vessel growth, on postnatal day 7 (P7) and P8. A group of rats that did not receive the injection of KRN 633 served as the non-ROP control. From P9 until P21, both ROP rats and non-ROP rats were split into three sub-groups (n=3-4/group) that received a daily treatment of olive oil, free lutein, or lutein emulsion (2 mg/kg BW). At P22, rats were euthanized, and astrocytes and retinal neurons were analyzed via immunohistochemistry.

Results: ROP caused a sparse network of astrocytes and decreased association of the astrocytes with blood vessels. Both the free lutein and lutein emulsion ameliorated those effects and significantly increased the area density of astrocytes. In the peripheral zone of the retina, ROP significantly decreased the number of neuronal cells. The free lutein group exhibited significantly increased numbers of neuronal cells, while the lutein emulsion treatment further improved the number back to the control level.

Conclusions: The administration of lutein to neonatal rats with ROP significantly improved the numbers of astrocytes and neuronal cells in the retina. These findings indicate that the lutein treatment may benefit the eye development of at-risk infants.

Funding Sources: Sigma Xi Grants in Aid of Research