Investigation of the association of pterygium with RHO proteins expression and polymorphism

Pterygium is a common ocular surface disease. The hypothesis that Rho proteins polymorphisms and expression may play a role in pterygium development is examined in this study. The aim of this study is to investigate the association between RHOA, RHOB, RHOC, RHOD, RND3(RHOE) gene polymorphisms, gene, and protein expressions and pterygium. RAC2, RAC3 gene and protein expressions were studied as well. A total of 383 pterygium patients and 331 healthy subjects (control group) with similar age and gender were enrolled in this study. Gene polymorphisms and expressions were identified by using BioMark HD dynamic array system with real-time PCR. Protein expressions were performed using Western blot method. There were statistically significant differences in genotype and allele frequencies for RHOB (rs2602160, rs62121967, rs62121968, rs11541350), RHOC (rs2230329, rs2306937, rs1804292, rs11102522, rs11538960), RHOD (rs11227675, rs61891303, rs7112925), and RND3(RHOE) (rs13418763, rs1441982, rs76447184) gene polymorphisms following Bonferroni correction (P<0.001). RHOC, RHOD, RHOE, RAC2, and RAC3 gene expressions were markedly elevated in pterygial tissues (P=0.0047, P=0.0003, P=0.0164, P=0.0464, and P=0.0002, respectively). There were marked decreases RHOB and RHOC gene expressions in pterygium patient's leukocytes (P=0.0113 and P=0.0236, respectively). Significant decrease in protein expression in pterygial tissues was detected for RhoD (P=0.0046). RhoA, RhoB protein expressions were markedly augmented in leukocytes (P=0.0180 and P=0.0033, respectively). Polymorphisms and expressions of Rho proteins have been demonstrated for the first time in the pterygium with this study. These results may help to understand the molecular mechanisms in the pterygium development and provide novel therapeutic targets. Key Words: Pterygium, Rho proteins, Polymorphism, Expresssion