Glaucoma is a complex neurodegenerative disease resulting in progressive optic neuropathy and is a leading cause of irreversible blindness worldwide. Primary open angle glaucoma (POAG) is the predominant form affecting 65.5 million people globally. Despite the prevalence of POAG and the identification of over 120 glaucoma related genetic loci, the underlaying molecular mechanisms are still poorly understood. The transforming growth factor beta (TGF-β) signalling pathway is implicated in the molecular pathology of POAG. To gain a better understanding of the role TGF-β2 plays in the glaucomatous changes to the molecular pathology in the trabecular meshwork, we employed RNA-Seq to delineate the TGF-β2 induced changes in the transcriptome of normal primary human trabecular meshwork cells (HTM). We identified a significant number of differentially expressed genes and associated pathways that contribute to the pathogenesis of POAG. The differentially expressed genes were predominantly enriched in ECM regulation, TGF-β signalling, proliferation/apoptosis, inflammation/wound healing, MAPK signalling, oxidative stress and RHO signalling. Canonical pathway analysis confirmed the enrichment of RhoA signalling, inflammatory-related processes, ECM and cytoskeletal organisation in HTM cells in response to TGF-β2. We also identified novel genes and pathways that were affected after TGF-β2 treatment in the HTM, suggesting additional pathways are activated, including Nrf2, PI3K-Akt, MAPK and HIPPO signalling pathways. The identification and characterisation of TGF-β2 dependent differentially expressed genes and pathways in HTM cells is essential to understand the patho-physiology of glaucoma and to develop new therapeutic agents.

This study aims to investigate the course of cartilage aging in healthy humans over 6 years via repeated T2 MRI relaxation time measurements of the knee, which serve as surrogate markers of knee cartilage composition. Methods: Ninety-two healthy subjects with no major risk factors and no previous clinical or radiographic diagnosis of osteoarthritis (OA) were selected from the Osteoarthritis Initiative (OAI) and stratified into three age groups: 45-49 (n¼29), 50-54 (n¼28) and 55þ (n¼35) years old. All subjects were serially examined at 2-year intervals with radiography and 3T MR imaging of the right knee over a 6-year follow-up period. Sagittal two-dimensional multispin multiecho images were acquired. A semi-automated spline-based segmentation was utilized to generate compartment-specific T2 relaxation time measurements of five knee cartilage compartments: patella, lateral femur, medial femur, lateral tibia and medial tibia. Statistical analyses employed the paired Ttest, chi-square test, McNemar's test and mixed random effects models adjusted for age, sex and BMI. Results: All three age groups showed similar patterns of cartilage aging in all cartilage knee compartments. From baseline to the 2-year followup, all age groups exhibited a significant increase (p<0.05) in mean T2 values showed in most compartments. This significant increase was most pronounced in the youngest age group (age 45-49 y, p<0.05) in all five compartments. Mean T2 values at subsequent time points (year 2 through 6), remained mostly unchanged (p>0.05) compared to the 2yfollow up time point as exemplified in Fig. 1. This suggests a plateauing of mean T2 values with aging. Mixed random effects modeling demonstrated an overall nonlinear pattern of mean T2 change over time. Conclusions: This longitudinal study characterizes, for the first time, the normal long-term evolution of human knee cartilage aging by using in vivo T2 MRI relaxation time measurements as a surrogate marker for cartilage composition. The results of our study suggest that with aging, human cartilage undergoes non-linear changes in cartilage composition which seem to follow a saturation curve-like and potentially plateauing pattern. Our findings of regular cartilage aging have to be taken into account when interpreting T2 relaxation time findings in osteoarthritic studies, but need further validation in larger datasets.

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Results: Participants were young (median age 25), mostly male, largely Caucasian and had substantial impairment and pain by KOOS at baseline (within 8 weeks of their injury, median time to baseline 17 days). For rs143383 genotype of 131 participants, 37 (28%) were TT, 81 (62%) were heterozygotes and 13 (10%) CC. There was no significant difference between the KOOS 4 of individuals with TT, TC or CC genotypes at baseline. There were similar increases in KOOS 4 in TT and TC individuals over the 3 month period (P<0.0001 for each). In contrast, KOOS 4 did not increase significantly over 3 months in CC homozygotes (P ¼ 0.35). A very similar pattern was seen for the rs143384 genotype, in terms of genotype frequency and change in KOOS over time. In a linear regression model of change in KOOS 4 over the 3 month period, CC at rs143383 was significantly associated with a smaller improvement in KOOS 4 compared with TC/TT (unadjusted coeff. À12.58 (À24.15, À1.0), P ¼ 0.033. When adjusted for other pre-defined explanatory variables (Age, Gender, extent of injury) a significant effect remained for the CC genotype (coeff. À11.89 (À23.48, À0.32), P ¼ 0.044. Conclusions: Possession of the CC genotype at SNP rs143383 of GDF-5 would appear to be an adverse prognostic factor for early clinical outcome after knee injury in this cohort.This finding should be tested in other joint injury cohorts, in larger numbers of individuals and in other populations. What effect this polymorphism has on subsequent incidence of post-traumatic osteoarthritis remains to be established.