FT011

FT011, a Novel Cardiorenal Protective Drug, Reduces Inflammation, Gliosis and Vascular Injury in Rats with Diabetic Retinopathy

Diabetic retinopathy features inflammation as well as injury to glial cells and the microvasculature, which are influenced by hypertension and overactivity of the renin-angiotensin system. FT011 is an anti-inflammatory and anti-fibrotic agent that has been reported to attenuate organ damage in diabetic rats with cardiomyopathy and nephropathy. However, the potential therapeutic utility of FT011 for diabetic retinopathy has not been evaluated. We hypothesized that FT011 would attenuate retinopathy in diabetic Ren-2 rats, which exhibit hypertension due to an overactive extra-renal renin-angiotensin system. Diabetic rats were studied for 8 and 32 weeks and received intravitreal injections of FT011 (50 μM) or vehicle (0.9% NaCl). Comparisons were to age-matched controls. In the 8-week study, retinal inflammation was examined by quantitating vascular leukocyte adherence, microglial/macrophage density and the expression of inflammatory mediators. Macroglial Müller cells, which exhibit a pro-inflammatory and pro-angiogenic phenotype in diabetes, were evaluated in the 8-week study as well as in culture following exposure to hyperglycaemia and FT011 (10, 30, 100 μM) for 72 hours. In the 32-week study, severe retinal vasculopathy was examined by quantitating acellular capillaries and extracellular matrix proteins. In diabetic rats, FT011 reduced retinal leukostasis, microglial density and mRNA levels of intercellular adhesion molecule-1 (ICAM-1). In Müller cells, FT011 reduced diabetes-induced gliosis and vascular endothelial growth factor (VEGF) immunolabeling and the hyperglycaemic-induced increase in ICAM-1, monocyte chemoattractant protein-1, CCL20, cytokine-induced neutrophil chemoattractant-1, VEGF and IL-6. Late intervention with FT011 reduced acellular capillaries and the elevated mRNA levels of collagen IV and fibronectin in diabetic rats. In conclusion, the protective effects of FT011 in cardiorenal disease extend to key elements of diabetic retinopathy and highlight its potential as a treatment approach.

FT011, a new anti-fibrotic drug, attenuates fibrosis and chronic heart failure in experimental diabetic cardiomyopathy

Aims: Cardiac remodelling in diabetes includes pathological accumulation of extracellular matrix and myocyte hypertrophy that contribute to heart dysfunction. Attenuation of remodelling represents a potential therapeutic target. We tested this hypothesis using a new anti-fibrotic drug, FT011 (Fibrotech Therapeutics Pty Ltd), on diabetic Ren-2 rats, a model which replicates many of the structural and functional manifestations of diabetic cardiomyopathy in humans.
Methods and results: Homozygous Ren-2 rats were randomized to receive streptozotocin or vehicle then further randomized to FT011 (200 mg/kg/day) or vehicle treatment for 6 weeks. Prior to tissue collection, cardiac function was assessed via echocardiography and cardiac catheterization. Total collagen deposition and cardiomyocyte hypertrophy were assessed by picrosirius red and haematoxylin and eosin staining, respectively. Macrophage interstitial infiltration and type I and III collagen were quantitated by immunostaining. Without affecting blood pressure or hyperglycaemia, treatment of diabetic rats with FT011 significantly attenuated interstitial fibrosis (total collagen, 5.09 ±1.28 vs, 2.42 ±0.43%/area; type I collagen, 4.09 ±1.16 vs. 1.42 ±0.38%/area; type III collagen, 1.52 ±0.33 vs. 0.71 ±0.14 %/area; P < 0.05), cardiomyocyte hypertrophy (882 ±38 vs. 659 ±28 ?m(2); P < 0.05), and interstitial macrophage influx (66 ±5.3 vs, 44 ±7.9 number/section; P < 0.05). Cardiac myopathic dilatation was normalized, as evidenced by reduced left ventricular inner diameter at diastole (0.642 ±0.016 vs. 0.577 ±0.024 cm), increased ejection fraction (75 ±1.1 vs. 83 ±1.2%) and preload recruitable stroke work relationship (44 ±6.7 vs. 77 ±6.3 slope-mmHg; P < 0.05), and reduced end-diastolic pressure-volume relationship (0.059 ±0.011 vs. 0.02 ±0.003 slope-mmHg/μL; P < 0.05).
Conclusions: A direct anti-fibrotic agent, FT011, attenuates cardiac remodelling and dysfunction in experimental diabetic cardiomyopathy. This represents a novel therapy for the treatment of diabetic cardiomyopathy associated with cardiac fibrosis and hypertrophy.

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-β 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-β 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.

Attenuation of Armanni-Ebstein lesions in a rat model of diabetes by a new anti-fibrotic, anti-inflammatory agent, FT011

Aims/hypothesis: A key morphological feature of diabetic nephropathy is the accumulation and deposition of glycogen in renal tubular cells, known as Armanni-Ebstein lesions. While this observation has been consistently reported for many years, the molecular basis of these lesions remains unclear.
Methods: Using biochemical and histochemical methods, we measured glycogen concentration, glycogen synthase and glycogen phosphorylase enzyme activities, and mRNA expression and protein levels of glycogenin in kidney lysates from control and transgenic (mRen-2)27 rat models of diabetes that had been treated with and without a new anti-fibrotic agent, FT011.
Results: Diabetic nephropathy was associated with increased glycogen content, increased glycogen synthase activity and decreased glycogen phosphorylase activity. Glycogenin, the key protein responsible for initiating the synthesis of each glycogen particle, had very high levels in the diabetic kidney together with increased mRNA expression compared with control kidneys. Treatment with FT011 did not change glycogen synthase or glycogen phosphorylase enzyme activities but prevented both glycogenin mRNA synthesis and accumulation of Armanni-Ebstein lesions in the diabetic kidney.
Conclusions/interpretation: Armanni-Ebstein lesions found in diabetic nephropathy are due to aberrant glycogenin protein levels and mRNA expression, providing an explanation for the increased glycogen concentration found within the diabetic kidney. FT011 treatment in diabetic rats reduced glycogenin levels and, subsequently, renal glycogen concentration.

A purpose-synthesised anti-fibrotic agent attenuates experimental kidney diseases in the rat

Background and purpose: Locally-active growth factors have been implicated in the pathogenesis of many diseases in which organ fibrosis is a characteristic feature. In the setting of chronic kidney disease (CKD), two such pro-fibrotic factors, transforming growth factor-β (TGF-β) and platelet-derived growth factor (PDGF) have emerged as lead potential targets for intervention. Given the incomplete organ protection afforded by blocking the actions of TGF-β or PDGF individually, we sought to determine whether an agent that inhibited the actions of both may have broader effects in ameliorating the key structural and functional abnormalities of CKD.
Experimental approach: Accordingly, we studied the effects of a recently described, small molecule anti-fibrotic drug, 3-methoxy-4-propargyloxycinnamoyl anthranilate (FT011, Fibrotech Therapeutics, Australia), which should have these effects.
Key results: In the in vitro setting, FT011 inhibited both TGF-β1 and PDGF-BB induced collagen production as well as PDGF-BB-mediated mesangial proliferation. Consistent with these in vitro actions, when studied in a robust model of non-diabetic kidney disease, the 5/6 nephrectomised rat, FT011 attenuated the decline in GFR, proteinuria and glomerulosclerosis (p<0.05 for all). Similarly, in the streptozotocin-diabetic Ren-2 rat, a model of advanced diabetic nephropathy, FT011 reduced albuminuria, glomerulosclerosis and tubulointerstitial fibrosis.
Conclusions and implications: Together these studies suggest that broadly antagonising growth factor actions, including those of TGF-β1 and PDGF-BB, has the potential to protect the kidney from progressive injury in both the diabetic and non-diabetic settings.