Immunohistochemical evidence of synaptic retraction, cytoarchitectural remodeling, and cell death in the inner retina of the rat model of oygen-induced retinopathy (OIR).
نویسندگان
چکیده
PURPOSE Postnatal exposure to hyperoxia destroys the plexiform layers of the neonatal rat retina, resulting in significant electroretinographic anomalies. The purpose of this study was to identify the mechanisms at the origin of this loss. METHODS Sprague-Dawley (SD) and Long Evans (LE) rats were exposed to hyperoxia from birth to postnatal day (P) 6 or P14 and from P6 to P14, after which rats were euthanatized at P6, P14, or P60. RESULTS At P60, synaptophysin staining confirmed the lack of functional synaptic terminals in SD (outer plexiform layer [OPL]) and LE (OPL and inner plexiform layer [IPL]) rats. Uneven staining of ON-bipolar cell terminals with mGluR6 suggests that their loss could play a role in OPL thinning. Protein kinase C(PKC)-α and recoverin (rod and cone ON-bipolar cells, respectively) showed a lack of dendritic terminals in the OPL with disorganized axonal projections in the IPL. Although photoreceptor nuclei appeared intact, a decrease in bassoon staining (synaptic ribbon terminals) suggests limited communication to the inner retina. Findings were significantly more pronounced in LE rats. An increase in TUNEL-positive cells was observed in LE (inner nuclear layer [INL] and outer nuclear layer [ONL]) and SD (INL) rats after P0 to P14 exposure (425.3%, 102.2%, and 146.3% greater than control, respectively [P < 0.05]). CONCLUSIONS Results suggest that cell death and synaptic retraction are at the root of OPL thinning. Increased TUNEL-positive cells in the INL confirm that cells die, at least in part, because of apoptosis. These findings propose a previously undescribed mechanism of cell death and synaptic retraction that are likely at the origin of the functional consequences of hyperoxia.
منابع مشابه
Naringin attenuates diabetic retinopathy by inhibiting inflammation, oxidative stress and NF-κB activation in vivo and in vitro
Objective(s): Naringin, an essential flavonoid, inhibits inflammatory response and oxidative stress in diabetes. However, whether naringin has beneficial effects on diabetic retinopathy (DR) remains unknown. Materials and Methods: Streptozotocin (STZ, 65 mg/kg) was intraperitoneally injected into male rats (8 weeks old weighting 200-250 g) to establish diabetic model, then naringin (20, 40 or 8...
متن کاملClinical and histopathologic features of canine oxygen-induced proliferative retinopathy.
PURPOSE In previous studies the morphologic features of the acute vaso-obliterative and vasoproliferative stages of oxygen-induced retinopathy (OIR) were quantified and described in the dog model of retinopathy of prematurity (ROP). In the present study the sequelae of these events were examined using fluorescein angiography and histologic, enzyme, and immunohistochemical techniques. METHODS ...
متن کامل670nm Photobiomodulation as a Novel Protection against Retinopathy of Prematurity: Evidence from Oxygen Induced Retinopathy Models
INTRODUCTION To investigate the validity of using 670nm red light as a preventative treatment for Retinopathy of Prematurity in two animal models of oxygen-induced retinopathy (OIR). MATERIALS AND METHODS During and post exposure to hyperoxia, C57BL/6J mice or Sprague-Dawley rats were exposed to 670 nm light for 3 minutes a day (9J/cm²). Whole mounted retinas were investigated for evidence of...
متن کاملTime Course of Axotomy-induced Changes in Synaptophysin Pattern and Synaptic Reaction of Spinal Motoneurons in Adult Rat
Background and Objective: Evaluation of degenerative changes of motoneurons and their related synapses can be useful in understanding the mechanisms of neurodegenerative diseases and their potential treatment. The present electron microscopic and immunohistochemical study investigates the axotomy-induced...
متن کاملRole of thromboxane in retinal microvascular degeneration in oxygen-induced retinopathy.
Microvascular degeneration is an important event in oxygen-induced retinopathy (OIR), a model of retinopathy of prematurity. Because oxidant stress abundantly generates thromboxane A2 (TxA2), we tested whether TxA2 plays a role in retinal vasoobliteration of OIR and contributes to such vascular degeneration by direct endothelial cytotoxicity. Hyperoxia-induced retinal vasoobliteration in rat pu...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Investigative ophthalmology & visual science
دوره 52 3 شماره
صفحات -
تاریخ انتشار 2011