Aqueous Humor IL-6, IL-8 And TNF-α Levels And Mutation Of CYP1B1 Gene In Primary Open-angle Glaucoma

Objective: This study is aimed to identify the influence of aqueous humor IL-6, IL-8 and TNF-α levels of primary open-angle glaucoma(POAG) in the pathogenesis of POAG. To study mutation of CYP1B1 susceptibility gene in POAG and investigate the role of CYP1B1 gene mutation on the pathogenesis of POAG.Methods: Literatures about aqueous humor IL-6, IL-8 and TNF-α levels in POAG patients were selected by the Pubmed and CNKI database. The results of IL-6, IL-8 and TNF-α level of the mean, standard deviation and the total number were performed in a meta-analysis.The study subjects included 416 patients who were diagnosed as POAG by standard ophthalmological examinations and 657 healthy controls. Genomic DNA was collected from peripheral blood of all the participants. The coding sequence of CYP1B1 was amplified by PCR from genomic DNA, followed by Sanger sequence and analysed for mutation of gene. Literatures about mutation of CYP1B1 gene associated with POAG were selected by the Pubmed and CNKI database. The results of literature and this study were performed in a meta-analysis.Results: IL-6 Meta-analysis included 94 cases of POAG patients and 130 controls. IL-8 Meta-analysis included 69 cases of POAG patients and 101 controls. TNF-α Meta analysis research included 85 cases of POAG patients and 168 controls. Aqueous humor IL-6 levels in POAG group and control group were 95% CI(-0.80,-0.24), Z = 3.61, P = 0.0003(P <0.05), showed that there were significant difference for IL-6 in the POAG group and control group. Aqueous humor IL-8 levels in POAG group and control group was 95% CI(0.15, 1.17), Z = 2.53, P = 0.01(P <0.05), showed that there were significant difference for IL-8 in the POAG group and control group. Aqueous humor TNF-α levels in POAG group and control group were 95% CI(-0.33, 0.32), Z = 0.02, P = 0.98(P> 0.05), showed that there were not significant difference for TNF-α in the POAG group and control group.Among 416 patients with POAG, 13 missenses mutations in CYP1B1 gene including nine known mutations(p.V95 A, p.L107 V, p.Q144 H, p.V198 I, P.E229 K, p.A287 T, p.V320 L, p.R368 H, p.R390H) and four novel mutations(p.P93 S, p.R259 C, p.A295 T, p.L475P) were determined. All these mutations were heterozygous. Four novel non-synonymous mutations were found in 6 patients with POAG, while not found in healthy control. The amino acid sequence of CYP1B1 was compared across different species, which revealed that the four novel mutations occurred at highly conserved positions and predicted to be damaging by the SIFT homology tool. The nine known mutations of CYP1B1 were found in 19 patients with POAG, but three mutations(p. L107 V, p.E229 K, p.V320L) were also found in the healthy control. In addition, six previously reported single nucleotide polymorphisms(p.R48 G, p.A119 S, p.V243 V, p.V432 L, p.D449 D, p.N453S) were observed in POAG patients and healthy controls, and showed no obvious frequency difference between patient groups and control groups. The meta-analysis studies included 2,133 patients with POAG and 2,299 healthy controls, which were shown that the OR value was 5.37(95%CI of 3.59-8.02) for CYP1B1 gene in POAG between mutation groups and control groups with p<0.00001. It also showed that there were significant difference of CYP1B1 gene in POAG between mutation groups and control groups.Conclusion: Aqueous humor IL-6 and IL-8 levels of determination results show IL-6 and IL-8 are associated with POAG, and may affect the progression of POAG. The results of this study for POAG provide some theoretical support and lay a solid foundation on the pathogenesis of POAG in immunology.Four novel mutations in CYP1B1 gene are firstly identified in patients with POAG, suggest that CYP1B1 gene mutations may play an important role in the incidence of POAG and CYP1B1 gene mutations may be the risk factors for the onset of POAG. These studies will help to improve understanding of CYP1B1 mutations in the pathogenesis of POAG.