Topical administration of lacritin is a novel therapy for aqueous-deficient dry eye disease.

PURPOSE: Lacritin is a tear glycoprotein with prosecretory, prosurvival, and mitogenic properties. We examined lacritin levels in the tears of Sjögren's syndrome (SS) patients and explored the therapeutic potential of topical lacritin for the treatment of keratoconjunctivitis sicca. METHODS: Tears from healthy controls (n = 14) and SS patients (n = 15) were assayed for lacritin using a C-terminal antibody. In a paired-eye study, autoimmune regulator (Aire) knockout (KO) mice (n = 7) were treated three times daily for 21 days with 10 µL of 4 µM lacritin (left eye) or vehicle (PBS) control (right eye). Tear secretion and ocular surface integrity were assessed at baseline and after treatment. Immunohistochemical staining of CD4+ T cells, cytokeratin-10 (K10), and cytokeratin-12 (K12) expression in the cornea and CD4+ T cell infiltration in the lacrimal glands were assessed. RESULTS: Lacritin monomer (421.8 ± 65.3 ng [SS] vs. 655.8 ± 118.9 ng [controls]; P = 0.05) and C-terminal fragment protein (125 ± 34.1 ng [SS] vs. 399.5 ± 84.3 ng [controls]; P = 0.008) per 100 µL of tear eluate were significantly lower in SS patients. In Aire KO mice treated with lacritin, tear secretion increased by 46% (13.0 ± 3.5 mm vs. 8.9 ± 2.9 mm; P = 0.01) and lissamine green staining score significantly decreased relative to baseline (-0.417 ± 0.06 vs. 0.125 ± 0.07; P = 0.02). Expression of K10 but not K12 in the cornea was significantly decreased in lacritin-treated eyes. Focal CD4+ T cell infiltration of the lacrimal glands was significantly reduced on the lacritin-treated side versus the untreated side. CONCLUSIONS: Lacritin is significantly reduced in the tears of SS patients. Topically administered lacritin has therapeutic potential for the treatment of aqueous-deficient dry eye disease.

Evaluation of SNPs on chromosome 2p with primary open angle glaucoma in the South Indian cohort.

PURPOSE: Glaucoma comprises a heterogeneous group of optic neuropathies with a complex genetic basis. It is the second leading cause of irreversible blindness in the world. This study investigates the association of SNPs on chromosome 2p with primary open angle glaucoma (POAG) in a Southern Indian population. METHODS: Case-control analysis was performed using 220 unrelated POAG cases and 220 age-matched unaffected controls recruited through the Aravind Eye Hospital and its outlying clinics. Five SNPs (rs1533428, rs12994401, rs10202118, rs11125375, and rs11889995) on chromosome 2p were evaluated in these two groups and genotyped using Taq Man SNP genotyping assay. Statistical analysis was performed using the SVS program package by Golden Helix to identify the distributions of allele and genotype frequencies, Fisher exact test P values, and odds ratios and to check Hardy-Weinberg equilibrium. RESULTS: Among the five SNPs screened, SNP rs10202118, showed a P = 0.026 for the basic allelic test, P = 0.004 for the genotypic test, and P = 0.0014 for the recessive model. The second suggestive marker was rs11125375, which also showed P = 0.033 for the recessive model. The associated SNPs formed a common disease haplotype. The remaining three SNPs showed insignificant association in this study population. CONCLUSIONS: This was the first study to demonstrate the association of SNPs on chromosome 2p in patients with POAG in the Indian population. The two tagging SNPs (rs10202118 and rs11125375) on chromosome 2p are the most likely sites underlying the significant association with POAG in this study population.

Association analysis of nine candidate gene polymorphisms in Indian patients with type 2 diabetic retinopathy.

BACKGROUND: Diabetic retinopathy (DR) is classically defined as a microvasculopathy that primarily affects the small blood vessels of the inner retina as a complication of diabetes mellitus (DM).It is a multifactorial disease with a strong genetic component. The aim of this study is to investigate the association of a set of nine candidate genes with the development of diabetic retinopathy in a South Indian cohort who have type 2 diabetes mellitus (T2DM). METHODS: Seven candidate genes (RAGE, PEDF, AKR1B1, EPO, HTRA1, ICAM and HFE) were chosen based on reported association with DR in the literature. Two more, CFH and ARMS2, were chosen based on their roles in biological pathways previously implicated in DR. Fourteen single nucleotide polymorphisms (SNPs) and one dinucleotide repeat polymorphism, previously reported to show association with DR or other related diseases, were genotyped in 345 DR and 356 diabetic patients without retinopathy (DNR). The genes which showed positive association in this screening set were tested further in additional sets of 100 DR and 90 DNR additional patients from the Aravind Eye Hospital. Those which showed association in the secondary screen were subjected to a combined analysis with the 100 DR and 100 DNR subjects previously recruited and genotyped through the Sankara Nethralaya Hospital, India. Genotypes were evaluated using a combination of direct sequencing, TaqMan SNP genotyping, RFLP analysis, and SNaPshot PCR assays. Chi-square and Fisher exact tests were used to analyze the genotype and allele frequencies. RESULTS: Among the nine loci (15 polymorphisms) screened, SNP rs2070600 (G82S) in the RAGE gene, showed significant association with DR (allelic P = 0.016, dominant model P = 0.012), compared to DNR. SNP rs2070600 further showed significant association with DR in the confirmation cohort (P = 0.035, dominant model P = 0.032). Combining the two cohorts gave an allelic P < 0.003 and dominant P = 0.0013). Combined analysis with the Sankara Nethralaya cohort gave an allelic P = 0.0003 and dominant P = 0.00011 with an OR = 0.49 (0.34 - 0.70) for the minor allele. In HTRA1, rs11200638 (G>A), showed marginal significance with DR (P = 0.055) while rs10490924 in LOC387715 gave a P = 0.07. No statistical significance was observed for SNPs in the other 7 genes studied. CONCLUSIONS: This study confirms significant association of one polymorphism only (rs2070600 in RAGE) with DR in an Indian population which had T2DM.