Expression Of HMGB1and Its Receptors In Rabbits With Traumatic Endophthalmitis

Endophthalmitis is one of the most serious complications of ocular trauma.Traumatic endophthalmitis develops fast and often leads to frustrating visual outcome.Traumatic endophthalmitis is one of the most common diseases that result in loss ofvision. General studies suggest that bacterial infection is the most direct andimportant cause of post-traumatic endophthalmitis. But the clinical application ofantibiotics suggested that antibiotics cannot prevent the development of inflammationin eyes. And there were studies suggesting that traumatic endophthalmitis developsnot in synchronization with the growth of bacteria, which may suggest that inaddition to the bacteria there are other factors participating in the development ofinflammation in eyes. Recent researches show that High-mobility group box proteins（1HMGB1）participates in the involved inflammatory response of mechanical trauma,bacterial infection and autoimmune diseases as an important regulatory factor.HMGB1combinating with its receptors，RAGE、TLR2and TLR4，can not onlymediate the early inflammatory response as alarmins but also play a role ininflammatory cascade as an proinflammtory factor. Whether does HMGB1play a rolein the process of Traumatic endophthalmitis, too? It remains to be seen. In this study,animal models of traumatic endophalmitis were established in rabbits to study thepathogenesis of endophthalmitis by analyzing the expressions of HMGB1and its receptors in retinas of rabbits with traumatic endophthalmitis.Materials and MethodsA total of24New zealand rabbits were randomly divided into four groups.Eachgroup has6rabbits. All the operation are done in the right eyes of all of the rabbits.Animal models of traumatic endophthalmitis were established in rabbits of Group oneand Group two by penetrating incision at the pars plana. And staphylococcus aureuswere injected into the vitreous cavity of traumatic eyes of Group two. And onlystaphylococcus aureus were injected into the vitreous cavity of the rabbits of Groupthree. Group four was sterile saline control group. Immunohistochemical method wasapplied to detect the expression of HMGB1and its receptors—RAGE、TLR2、TLR4in the retina on the third day after establishing the models. We observed the clinicalmanifestations respectively after6hours,12hours,24hours,48hours,72hours ofestablishing the models with slit lamp and indirect ophthalmofundoscope,thenevaluated the inflammation with clinical grading system. Rabbits were raised indoorsin a12/12circadian rhythm at room temperature22°C-25°C.Results1．observation of inflammation at different times after establishing the modelsNo inflammation in Group four. The inflammation in Group one was markedlylighter than Group two and group three. And there existed significant differencebetween Group one and Group two or group three (P<0.0083). There was no obviousdifference in inflammation between Group two and Group three.2．Expression of HMGB1and its receptors----RAGE、TLR2and TLR4in retina.The expression of HMGB1are strong positive in group one、group two and groupthree，but negative in group four. There were significantly statistical differencesbetween the former three groups and group four (P<0.0083). But there were nosignificantly statistical differences among the former three groups. The expression of RAGE in the former three groups and group four wererespectively strongly positive and weakly positive. There were significantly statisticaldifferences between the former three groups and group four (P<0.0083). But therewere no significantly statistical differences among the former three groups.The expression of TLR2in group two and group three were strongly positive,but moderately positive and weakly positive respectively in group one and the groupfour. There were significantly statistical differences between the former three groupsand group four (P<0.0083). And there were significantly statistical differencesbetween the group one and group two or group three (P<0.0083), but there were nosignificantly statistical differences between group two and group three.The expression of TLR4in the group one and two were moderately positive,but weakly positive in group three and four. And There were significantly statisticaldifferences between the former two groups and the latter two groups(P<0.0083), butthere were no significantly statistical differences not only between group one andgroup two but also between group two and group three.ConclusionsHMGB1and its receptors, RAGE、TLR2and TLR4expressed in higher elvelthan normal in retinas in the early stage in endophthalmitis induced by sterile trauma,trauma with staphylococcus aureus or staphylococcus aureus only. So in the earlysrage of endophthalmitis, maybe we can use HMGB1-antibody or ligands of receptorsto prevent inflammation.