title: Activated complement classical pathway in a murine model of oxygen-induced retinopathy.
abstract: OBJECTIVE
  To investigate whether the complement system is involved in a murine model of oxygen-induced retinopathy (OIR).
  
  
  METHODS
  Forty C57BL/6J newborn mice were divided randomly into OIR group and control group. OIR was induced by exposing mice to 75%±2% oxygen from postnatal 7d (P7) to P12 and then recovered in room air. For the control group, the litters were raised in room air. At the postnatal 17d (P17), gene expressions of the complement components of the classical pathway (CP), the mannose-binding lectin (MBL) pathway and the alternative pathway (AP) in the retina were determined by quantitative real-time polymerase chain reaction (RT-PCR). Retinal protein expressions of the key components in the CP were examined by Western blotting.
  
  
  RESULTS
  Whole mounted retina in the OIR mice showed area of central hypoperfusion in both superficial and deep layers and neovascular tufts in the periphery. The expressions of C1qb and C4b genes in the OIR retina were significantly higher than those of the controls. The expression of retinal complement factor B (CFB) gene in OIR mice was significantly lower than those of the controls. However, the expressions of C3 and complement factor H (CFH) genes were higher. The protein synthesis of the key components involved in the CP (C1q, C4 and C3) were also significantly higher in OIR mouse retina. Although MBL-associated serine protease 1 (MASP1) and MASP2 were detected in both the OIR and the control groups, the expressions were weak and the difference between the two groups was not significant.
  
  
  CONCLUSIONS
  Our data suggest that the complement system CP is activated during the pathogenesis of murine model of OIR.
authors.affiliation: Department of Ophthalmology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Ophthalmology, Chongqing Eye Institute, Chongqing 400016, China ; Department of Ophthalmology, Chongqing Maternal and Child Health-Care Hospital, Chongqing 400013, China.
authors.forename: Xue-Ying
authors.initials: XY
authors.lastname: Tao
authors.affiliation: Department of Ophthalmology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Ophthalmology, Chongqing Eye Institute, Chongqing 400016, China.
authors.forename: Shi-Jie
authors.initials: SJ
authors.lastname: Zheng
authors.affiliation: Department of Ophthalmology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Ophthalmology, Chongqing Eye Institute, Chongqing 400016, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Lei
keywords: classical pathway; complement activation; mouse; oxygen-induced retinopathy; retina