Expression And Significances Of Neuroglobin (NGB) And Transforming Growth Factor-β₂ (TGF-β₂) In Rabbit With Ocular Trauma In A Plateau Hypoxia Area

Objective: We observed the expression of retina' s neuroglobin and cornea' s transforming growth factor-β₂ in sub-plateau area and plateau area after ocular trauma, and discussed the relationship between ocular recovery with trauma and the two factors in the plateau hypoxia area, in order to offer a molecular therapy for anoxic ocular disease.Methods: 30 (n=60) rabbits were randomized into 3 groups, un-injury group in sub-plateau area (altitude 1517m), sub-plateau group (altitude 1517m) and plateau group (altitude 3840m). Ocular trauma models were established in sub-plateau group and plateau group (both eyeballs were injured). Cornea and retina were prepared from rabbit at 6 times, which underwent damage for 2 hours, 6 hours, 1 day, 3 days, 7 days, 14 days. NGB in the retina and TGF-β₂ in the cornea were detected by immunohistochemical techniques respectively.Results: The kinetic tendency of NGB-IR (NGB-immunoreactant) is similar between sub-plateau group and plateau group. It decreases at early time. The times are as follows, 2 hours, 6 hours, 1day, 3 days and 7 days. The value is the smallest on the 7th day. But it regains the normal level on the 14th day. The expression of NGB-IR in sub-plateau group and plateau group is higher than that in un-injury group of the 6 times (It has negative correlation between factor's expression and gray value.) Furthermore, compared sub-plateau group' s value with plateau group' s value, it has statistical significance at the 6th hour and on the 1st day (P<0.05). In un-injury group, NGB-IR expresses at ganglion cell layer, inner nuclear layer and cone and rod layer. Besides the above-mentioned positions it is also expresses at the internal limiting membrane, outer plexiform layer, internal plexiform layer in sub-plateau group and plateau group. The gray value difference of TGF-β₂-IR (TGF-β₂-immunoreactant) has statistics significance between sub-plateau group and plateau group of the 6 times (P<0.05). The gray value of TGF-β₂ is higher in sub-plateau group than that in plateau group. The un-injury group' s value is the highest of the three gruops. The kinetic tendency shows that immunoreactant of TGF-β₂ decreasing at early time and increasing at later time. However, it regains the normal level on the 7th day.Conclusions: (1) Ocular trauma and hypoxia make NGB expressed at internal limiting membrane, outer plexiform layer and internal plexiform layer. (2)The increasing expression of retina' s NGB in plateau group promotes the survival of retina with hypoxic injury, and potentially limiting the tissue' s damage. The increasing expression of cornea's TGF-β₂ at early time enhances the negative restrain growing effect, therefore, the quality of corneal transparence decreases. (3)This research shows that NGB and TGF-β₂ play important roles in tissue' s recovery with visual hypoxic injury. In order to offer comprehensive therapy for Ocular trauma, the next experiment may use these two factors to intervene the hypoxic eye injury.