Chymase as a Novel Therapeutic Target in Acute Pancreatitis

Acute pancreatitis is still a life-threatening disease without an evidenced therapeutic agent. In this study, the effect of chymase in acute pancreatitis and the possible effect of a chymase inhibitor in acute pancreatitis were investigated. Hamsters were subcutaneously administered 3.0 g/kg of L-arginine to induce acute pancreatitis. Biological markers were measured 1, 2, and 8 h after L-arginine administration. To investigate the effect of a chymase inhibitor, a placebo (saline) or a chymase inhibitor TY-51469 (30 mg/kg) was given 1 h after L-arginine administration. The survival rates were evaluated for 24 h after L-arginine administration. Significant increases in serum lipase levels and pancreatic neutrophil numbers were observed at 1 and 2 h after L-arginine administration, respectively. Significant increases in pancreatic neutrophil numbers were observed in the placebo-treated group, but they were significantly reduced in the TY-51469-treated group. A significant increase in the pancreatic tumor necrosis factor-α mRNA level was observed in the placebo-treated group, but it disappeared in the TY-51469-treated group. Chymase activity significantly increased in the placebo-treated group, but it was significantly reduced by treatment with TY-51469. The survival rate significantly improved in the TY-51469-treated group. A chymase inhibitor may become a novel therapeutic agent for acute pancreatitis.

Development of artificial blood vessels made of new materials, used for vascular access in renal dialysis

It can take many years to find a matched kidney donor and, in some cases, a matched donor is never found. Dialysis machines and methods of accessing a patient's cardiovascular system mean patients can live well whilst waiting for a transplant. Patients must undergo one of two surgical procedures before their first haemodialysis; receiving either an arteriovenous fistula or an arteriovenous graft, which join the artery to the vein and facilitate the transfer of blood from body to machine. If a graft is needed, an operation to insert a polytetrafluoroethylene (PTFE) based device is required but complications can arise in the form of blockages. Denan Jin, Department of Innovative Medicine, Osaka Medical and Pharmaceutical University, Japan, has spent years conducting research on the issues related to PTFE device blockage. He worked with his mentor Professor Mizuo Myazaki before his retirement and his colleague Professor Shinji Takai, and these collaborations led to understanding of the major causes of these blockages. Jin and his team are working to develop means to increase the longevity of PTFE grafts. The researchers have discovered two key mechanisms through which the grafts become blocked, which has led to the identification of two possible routes for preventing blockages. These relate to fibroblasts and the researchers have also identified the enzyme chymase as a key intermediate in the process of fibroblast recruitment. Jin and the team are proposing the use of an alternative to PTFE and the development of an effective chymase inhibitor to reduce the recruitment of fibroblasts to the graft site.

Effects of the chymase inhibitor fulacimstat in diabetic kidney disease—results from the CADA DIA trial

Background The protease chymase generates multiple factors involved in tissue remodelling including angiotensin II (Ang II) and has been implicated in the pathophysiology of diabetic kidney disease (DKD). This study investigated the effects of the chymase inhibitor fulacimstat on albuminuria in patients with Type II diabetes mellitus and a clinical diagnosis of DKD. Methods In this double-blind, randomized, placebo-controlled trial, patients were on the maximum tolerated dose of either an Ang II receptor blocker or an Ang-converting enzyme inhibitor since at least 3 months before the screening visit. Eligible patients were randomized in a 2:1 ratio to treatment with either 25 mg fulacimstat (n = 99) or placebo (n = 48) twice daily on top of standard of care. Results The randomized patients had a mean urine albumin–creatinine ratio (UACR) of 131 mg/g (range: 29–2429 mg) and a mean (standard deviation) estimated glomerular filtration rate of 60.8 ± 16.9 mL/min/1.73 m2 before treatment start. Fulacimstat was safe and well tolerated, and achieved mean total trough concentrations that were ∼9-fold higher than those predicted to be required for minimal therapeutic activity. UACR increased by 27.4% [coefficient of variation (CV) 86%] and 3% (CV 88.9%) after 24 weeks of treatment with placebo or fulacimstat, respectively. Analysis of covariance revealed a least square mean UACR ratio (fulacimstat/placebo) of 0.804 (90% CI 0.627–1.030, P = 0.1477), indicating a statistically non-significant UACR reduction of 19.6% after fulacimstat treatment compared with placebo. Conclusions Fulacimstat was safe and well tolerated but did not reduce albuminuria in patients with DKD. These findings do not support a therapeutic role for chymase inhibition in DKD.

Chymase as a Possible Therapeutic Target for Amelioration of Non-Alcoholic Steatohepatitis

The development and progression of non-alcoholic steatohepatitis (NASH) are linked to oxidative stress, inflammation, and fibrosis of the liver. Chymase, a chymotrypsin-like enzyme produced in mast cells, has various enzymatic actions. These actions include activation of angiotensin II, matrix metalloproteinase (MMP)-9, and transforming growth factor (TGF)-β, which are associated with oxidative stress, inflammation, and fibrosis, respectively. Augmentation of chymase activity in the liver has been reported in various NASH models. Generation of hepatic angiotensin II and related oxidative stress is upregulated in NASH but attenuated by treatment with a chymase inhibitor. Additionally, increases in MMP-9 and accumulation of inflammatory cells are observed in NASH but are decreased by chymase inhibitor administration. TGF-β and collagen I upregulation in NASH is also attenuated by chymase inhibition. These results in experimental NASH models demonstrate that a chymase inhibitor can effectively ameliorate NASH via the reduction of oxidative stress, inflammation, and fibrosis. Thus, chymase may be a therapeutic target for amelioration of NASH.

Mechanism of Anti-Hepatic Fibrosis of TGF-β1/Smad Signaling Pathway Affected by Chymase Inhibitors

Objective: This study aims to investigate the pathological mechanism of chymase inhibitors (Chy-I) on liver tissue in rats with hepatic fibrosis. Methods: Rats in the model group and chymase inhibitor group were established by using carbon tetrachloride. Rats in the chymase inhibitor group intragastrically received Chy-I (10 mg/kg/d) during the modeling. The pathological changes of rat liver tissues induced by chymase inhibitors were investigated, and the mRNA and protein expression of TGF-β1, Smad3 and Smad7 were observed in rat liver tissues. Results: When compared to the model group, The results presented that the liver tissue pathology of rats had been significantly improved in the Chy-I group. When compared to the normal group, the mRNA expression level and protein expression level of TGF-β1 and Smad3 in liver tissues had significantly increased, but the mRNA expression level and protein expression level of Smad7 significantly decreased (p < 0 05). When compared to the model group, the mRNA expression level and protein expression level of TGF-β1 and Smad3 was significantly downregulated, but the mRNA expression level and protein expression level of Smad7 was significantly upregulated in the Chy-I group. Conclusion:Chy-I plays an active role in blocking hepatic fibrosis in rats by affecting the TGF-β1/Smad signaling pathway in liver tissues through multiple sites.

87Effects of the chymase inhibitor fulacimstat on adverse cardiac remodelling after acute myocardial infarction - Results of the CHIARA MIA 2 trial

Introduction Adverse cardiac remodelling represents the most important risk factor for the development of heart failure (HF) after myocardial infarction (MI). Chymase is a protease that generates locally pro-fibrotic factors such as angiotensin II, TGFβ, and matrixmetallproteases that contribute to tissue remodelling. Purpose This phase IIa study examined the effects of the chymase inhibitor fulacimstat on functional parameters of adverse cardiac remodelling after acute MI. Methods A double-blind, multinational, randomized, placebo-controlled study was performed in patients after first STEMI who were treated with primary percutaneous coronary intervention within 24h of symptom onset. To enrich for patients at risk of adverse remodelling, main inclusion criteria were a left-ventricular ejection fraction (LVEF)≤45% and an infarct size>10% on day 5 to 9 post MI as measured by cardiac MRI. On day 6 to 12 post MI, patients were randomized to treatment with either 25 mg fulacimstat (n=54) or placebo (n=53) twice daily on top of standard of care. The changes in LVEF, LVEDVI, and LVESVI from baseline to 6 months of treatment were analyzed by a central blinded cardiac MRI core laboratory. Results Fulacimstat was safe and well tolerated, 64.8% of patients treated with fulacimstat and 75.5% of patients treated with placebo reported treatment emergent adverse events. Fulacimstat achieved exposures that were approximately 10-fold higher than those predicted to be required for minimal therapeutic activity. After six months of treatment, there were no effects of fulacimstat compared to placebo on the changes in LVEF, LVEDVI, and LVESVI (see Table). Analysis of primary efficacy parameters Parameter Placebo Fulacimstat p-value LVEF (%) baseline 37.2±6.1 39.1±5.5 0.15 6 months 41.2±8.4 42.6±8.4 0.45 delta 4.0±5.0 3.5±5.4 0.69 LVEDVI (mL/m2) baseline 80.0±17.1 77.4±18.2 0.51 6 months 85.1±19.1 84.7±23.4 0.94 delta 5.1±18.9 7.3±13.3 0.54 LVESVI (mL/m2) baseline 50.5±13.0 47.3±12.3 0.26 6 months 51.1±16.9 49.6±18.1 0.71 delta 0.6±14.8 2.3±11.2 0.56 Data are given as mean ± standard deviation. Conclusion Fulacimstat was safe and well tolerated in patients with left-ventricular dysfunction (LVD) after first STEMI but had no effect on adverse cardiac remodelling in the experimental setting of this study. Acknowledgement/Funding The study was funded by its sponsor BAYER AG