Transcriptomic analysis of choroidal neovascularization reveals dysregulation of immune and fibrosis pathways that are attenuated by a novel anti-fibrotic treatment.

Neovascular AMD (nAMD) leads to vision loss and is a leading cause of visual impairment in the industrialised world. Current treatments that target blood vessel growth have not been able to treat subretinal fibrosis and nAMD patients continue to lose vision. The molecular mechanisms involved in the development of fibrotic lesions in nAMD are not well understood. The aim of this study was to further understand subretinal fibrosis in the laser photocoagulation model of choroidal neovascularization (CNV) by studying the whole transcriptome of the RPE/choroid following CNV and the application of an anti-fibrotic following CNV. Seven days after laser induced CNV, RPE and choroid tissue was separated and underwent RNAseq. Differential expression analysis and pathway analysis revealed an over representation of immune signalling and fibrotic associated pathways in CNV compared to control RPE/choroid tissue. Comparisons between the mouse CNV model to human CNV revealed an overlap in upregulated expression for immune genes (Ccl2, Ccl8 and Cxcl9) and extracellular matrix remodeling genes (Comp, Lrcc15, Fndc1 and Thbs2). Comparisons between the CNV model and other fibrosis models showed an overlap of over 60% of genes upregulated in either lung or kidney mouse models of fibrosis. Treatment of CNV using a novel cinnamoyl anthranilate anti-fibrotic (OCX063) in the laser induced CNV model was selected as this class of drugs have previously been shown to target fibrosis. CNV lesion leakage and fibrosis was found to be reduced using OCX063 and gene expression of genes within the TGF-beta signalling pathway. Our findings show the presence of fibrosis gene expression pathways present in the laser induced CNV mouse model and that anti-fibrotic treatments offer the potential to reduce subretinal fibrosis in AMD.

NP202 treatment improves left ventricular systolic function and attenuates pathological remodelling following chronic myocardial infarction.

AIMS: Myocardial injury is a major contributor to left ventricular (LV) remodelling activating neurohormonal and inflammatory processes that create an environment of enhanced oxidative stress. This results in geometric and structural alterations leading to reduced LV systolic function. In this study we evaluated the efficacy of NP202, a synthetic flavonol, on cardiac remodelling in a chronic model of myocardial infarction (MI). MAIN METHODS: A rat model of chronic MI was induced by permanent surgical ligation of the coronary artery. NP202 treatment was commenced 2 days post-MI for 6 weeks at different doses (1, 10 and 20 mg/kg/day) to determine efficacy. Cardiac function was assessed by echocardiography prior to treatment and at week 6, and pressure-volume measurements were performed prior to tissue collection. Tissues were analysed for changes in fibrotic and inflammatory markers using immunohistochemistry and gene expression analysis. KEY FINDINGS: Rats treated with NP202 demonstrated improved LV systolic function and LV geometry compared to vehicle treated animals. Furthermore, measures of hypertrophy and interstitial fibrosis were attenuated in the non-infarct region of the myocardium with NP202 at the higher dose of 20 mg/kg (P < 0.05). At the tissue level, NP202 reduced monocyte chemoattractant protein-1 expression (P < 0.05) and tended to attenuate active caspase-3 expression to similar levels observed in sham animals (P = 0.075). SIGNIFICANCE: Improved LV function and structural changes observed with NP202 may be mediated through inhibition of inflammatory and apoptotic processes in the MI setting. NP202 could therefore prove a useful addition to standard therapy in patients with post-MI LV dysfunction.

A new anti-fibrotic drug attenuates cardiac remodeling and systolic dysfunction following experimental myocardial infarction.

BACKGROUND: Pathological deposition of extracellular matrix in the non-infarct zone (NIZ) of the ventricle post myocardial infarction (MI) is a key contributor to cardiac remodeling and heart failure. FT011, a novel antifibrotic compound, was evaluated for its efficacy in neonatal cardiac fibroblasts (NCF) and in an experimental MI model. METHODS AND RESULTS: Collagen synthesis in NCF was determined by (3)H-proline incorporation following stimulation with TGF-ß or angiotensin II (Ang II). FT011 inhibited collagen synthesis to both agents in a dose dependent manner. In vivo, Sprague Dawley rats underwent left anterior descending coronary artery ligation or sham surgery and were randomized one week later to receive either FT011 (200mg/kg/day) or vehicle for a further 4 weeks. Echocardiography and cardiac catheterization were performed, and tissues were collected for histological analysis of collagen, myocyte hypertrophy, interstitial macrophage accumulation and Smad2 phosphorylation. mRNA expression of collagens I and III and TGF-ß was measured using in situ hybridization and RT-PCR, respectively. FT011 treatment was associated with improved cardiac function (increased ejection fraction, fraction shortening and preload recruitable stroke work) and myocardial remodeling (reduced left ventricular diameter and volume at both end diastolic and systolic) compared with vehicle treatment. FT011 significantly reduced collagen matrix deposition, myocyte hypertrophy and interstitial macrophage infiltration, and mRNA expression of collagens I and III in NIZ compared with vehicle treatment. CONCLUSION: Anti-fibrotic therapy with FT011 in MI rats attenuated fibrosis and preserved systolic function.