Rathi Sonika, Jalali Subhadra, Patnaik Satish, Shahulhameed Shahna, Musada Ganeswara R, Balakrishnan Divya, Rani Padmaja K, Kekunnaya Ramesh, Chhablani Preeti Patil, Swain Sarpras, Giri Lopamudra, Chakrabarti Subhabrata, Kaur Inderjeet
Prof Brien Holden Eye Research Centre, Hyderabad, India.
Smt. Kanuri Santhamma Centre for Vitreo Retinal Diseases, Hyderabad, India.
Front Immunol. 2017 Dec 22;8:1868. doi: 10.3389/fimmu.2017.01868. eCollection 2017.
Retinopathy of prematurity (ROP) is a neurovascular complication in preterm babies, leading to severe visual impairment, but the underlying mechanisms are yet unclear. The present study aimed at unraveling the molecular mechanisms underlying the pathogenesis of ROP. A comprehensive screening of candidate genes in preterms with ROP ( = 189) and no-ROP ( = 167) was undertaken to identify variants conferring disease susceptibility. Allele and genotype frequencies, linkage disequilibrium and haplotypes were analyzed to identify the ROP-associated variants. Variants in ( = 2.94 × 10), ( = 1.71 × 10), ( = 9.2 × 10), ( = 2.99 × 10), and ( = 1.32 × 10) genes exhibited significant associations with ROP. Further, a quantitative assessment of 27 candidate proteins and cytokines in the vitreous and tear samples of babies with severe ROP ( = 30) and congenital cataract ( = 30) was undertaken by multiplex bead arrays and further validated by western blotting and zymography. Significant elevation and activation of MMP9 ( = 0.038), CFH ( = 2.24 × 10), C3 ( = 0.05), C4 ( = 0.001), IL-1ra ( = 0.0019), vascular endothelial growth factor (VEGF) ( = 0.0027), and G-CSF ( = 0.0099) proteins were observed in the vitreous of ROP babies suggesting an increased inflammation under hypoxic condition. Along with inflammatory markers, activated macrophage/microglia were also detected in the vitreous of ROP babies that secreted complement component C3, VEGF, IL-1ra, and MMP-9 under hypoxic stress in a cell culture model. Increased expression of the inflammatory markers like the IL-1ra ( = 0.014), MMP2 ( = 0.0085), and MMP-9 ( = 0.03) in the tears of babies at different stages of ROP further demonstrated their potential role in disease progression. Based on these findings, we conclude that increased complement activation in the retina/vitreous in turn activated microglia leading to increased inflammation. A quantitative assessment of inflammatory markers in tears could help in early prediction of ROP progression and facilitate effective management of the disease, thereby preventing visual impairment.
早产儿视网膜病变（ROP）是早产儿的一种神经血管并发症，可导致严重视力损害，但其潜在机制尚不清楚。本研究旨在揭示ROP发病机制的分子机制。对患有ROP的早产儿（n = 189）和未患ROP的早产儿（n = 167）进行了候选基因的全面筛查，以确定赋予疾病易感性的变异。分析等位基因和基因型频率、连锁不平衡和单倍型，以鉴定与ROP相关的变异。[基因名称]（n = 2.94×10）、[基因名称]（n = 1.71×10）、[基因名称]（n = 9.2×10）、[基因名称]（n = 2.99×10）和[基因名称]（n = 1.32×10）基因中的变异与ROP表现出显著关联。此外，通过多重微珠阵列对患有严重ROP的婴儿（n = 30）和先天性白内障婴儿（n = 30）的玻璃体和泪液样本中的27种候选蛋白和细胞因子进行了定量评估，并通过蛋白质印迹法和酶谱法进一步验证。在ROP婴儿的玻璃体中观察到MMP9（P = 0.038）、CFH（P = 2.24×10）、C3（P = 0.05）、C4（P = 0.001）、IL-1ra（P = 0.0019）、血管内皮生长因子（VEGF）（P = 0.0027）和G-CSF（P = 0.0099）蛋白的显著升高和激活，表明在缺氧条件下炎症增加。除了炎症标志物外，在ROP婴儿的玻璃体中还检测到活化的巨噬细胞/小胶质细胞，其在细胞培养模型中在缺氧应激下分泌补体成分C3、VEGF、IL-1ra和MMP-9。在ROP不同阶段婴儿的泪液中，IL-1ra（P = 0.014）、MMP2（P = 0.0085）和MMP-9（P = 0.03）等炎症标志物的表达增加，进一步证明了它们在疾病进展中的潜在作用。基于这些发现，我们得出结论，视网膜/玻璃体中补体激活增加进而激活小胶质细胞，导致炎症增加。对泪液中炎症标志物的定量评估有助于早期预测ROP进展，并促进疾病的有效管理，从而预防视力损害。
