A novel, pan-PDE inhibitor exerts anti-fibrotic effects in human lung fibroblasts via inhibition of TGF-β\beta signaling and activation of cAMP/PKA signaling

Phosphodiesterase (PDE) inhibitors are currently a widespread and extensively studied group of anti-inflammatory and anti-fibrotic compounds which may find use in the treatment of numerous lung diseases, including asthma and chronic obstructive pulmonary disease. Several PDE inhibitors are currently in clinical development, and some of them, e.g., roflumilast, are already recommended for clinical use. Due to numerous reports indicating that elevated intracellular cAMP levels may contribute to the alleviation of inflammation and airway fibrosis, new and effective PDE inhibitors are constantly being sought. Recently, a group of 7,8-disubstituted purine-2,6-dione derivatives, representing a novel and prominent pan-PDE inhibitors has been synthesized. Some of them were reported to modulate transient receptor potential ankyrin 1 (TRPA1) ion channels as well. In this study, we investigated the effect of selected derivatives (832-a pan-PDE inhibitor, 869-a TRPA1 modulator, and 145-a pan-PDE inhibitor and a weak TRPA1 modulator) on cellular responses related to airway remodeling using MRC-5 human lung fibroblasts. Compound 145 exerted the most considerable effect in limiting fibroblast to myofibroblasts transition (FMT) as well as proliferation, migration, and contraction. The effect of this compound appeared to depend mainly on its strong PDE inhibitory properties, and not on its effects on TRPA1 modulation. The strong anti-remodeling effects of 145 required activation of the cAMP/protein kinase A (PKA)/cAMP response element-binding protein (CREB) pathway leading to inhibition of transforming growth factor type β1 (TGF-β1) and Smad-dependent signaling in MRC-5 cells. These data suggest that the TGF-β pathway is a major target for PDE inhibitors leading to inhibitory effects on cell responses involved in airway remodeling. These potent, pan-PDE inhibitors from the group of 7,8-disubstituted purine-2,6-dione derivatives, thus represent promising anti-remodeling drug candidates for further research

Synthesis and in vitro evaluation of anti-inflammatory, antioxidant, and anti-fibrotic effects of new 8-aminopurine-2,6-dione-based phosphodiesterase inhibitors as promising anti-asthmatic agents

Phosphodiesterase (PDE) inhibitors are currently an extensively studied group of compounds that can bring many benefits in the treatment of various inflammatory and fibrotic diseases, including asthma. Herein, we describe a series of novel N’-phenyl- or N’-benzylbutanamide and N’-arylidenebutanehydrazide derivatives of 8-aminopurine-2,6-dione (27–43) and characterized them as prominent pan-PDE inhibitors. Most of the compounds exhibited antioxidant and anti-inflammatory activity in lipopolysaccharide (LPS)-induced murine macrophages RAW264.7. The most active compounds (32–35 and 38) were evaluated in human bronchial epithelial cells (HBECs) derived from asthmatics. To better map the bronchial microenvironment in asthma, HBECs after exposure to selected 8-aminopurine-2,6-dione derivatives were incubated in the presence of two proinflammatory and/or profibrotic factors: transforming growth factor type β (TGF-β) and interleukin 13 (IL-13). Compounds 32–35 and 38 significantly reduced both IL-13- and TGF-β-induced expression of proinflammatory and profibrotic mediators, respectively. Detailed analysis of their inhibition preferences for selected PDEs showed high affinity for isoenzymes important in the pathogenesis of asthma, including PDE1, PDE3, PDE4, PDE7, and PDE8. The presented data confirm that structural modifications within the 7 and 8 positions of the purine-2,6-dione core result in obtaining preferable pan-PDE inhibitors which in turn exert an excellent anti-inflammatory and anti-fibrotic effect in the bronchial epithelial cells derived from asthmatic patients. This dual-acting pan-PDE inhibitors constitute interesting and promising lead structures for further anti-asthmatic agent discovery

Synthesis of 7,8-disubstituted derivatives of 1,3-dimethylpurine-2,6-dione with carboxylic and amide moieties as potential PDE inhibitors.

We wstępie niniejszej pracy scharakteryzowano fosfodiesterazę 7 (PDE7) oraz przedstawiono przegląd dotychczas poznanych inhibitorów tego izoenzymu, z różnych grup chemicznych, o potencjalnym zastosowaniu m.in. w chorobach neurodegeneracyjnych i immunologicznych. Szczególną uwagę zwrócono na nowe klasy dualnych inhibitorów PDE4/7, PDE7/8 oraz PDE7/GSK-3 o synergistycznym mechanizmie działania. Poszukiwanie tego typu związków stanowi nową strategię badawczą, której celem jest zwiększenie skuteczności, rozszerzenie zakresu terapeutycznych zastosowań oraz zmniejszenie działań niepożądanych. Celem niniejszej pracy było zaprojektowanie i synteza amidowych i N-arylidenohydrazydowych pochodnych 1,3-dimetylo-2,3,6,7-tetrahydro-1H-puryno-2,6-dionu jako potencjalnych dualnych inhibitorów PDE4/7. W części eksperymentalnej przedstawiono wieloetapową syntezę oraz właściwości fizykochemiczne zaprojektowanych amidowych (seria I, II) oraz N-arylidenohydrazydowych (seria III, IV) pochodnych 1,3-dimetylo-2,3,6,7-tetrahydro-1H-puryno-2,6-dionu, zawierających w położeniu 8 tego układu ugrupowanie alkiloaminowe (seria I, III) lub arylometyloaminowe (seria II, IV). Strukturę zsyntetyzowanych nowych związków (13 pośrednich i 18 finalnych) potwierdzono analizą spektralną 1H NMR, masę cząsteczkową potwierdzono LC/MS, natomiast czystość oznaczono metodą UPLC. Otrzymane nowe związki zostały przekazane do badań farmakologicznych, w celu określenia ich zdolności hamowania PDE4B i PDE7A w testach in vitro.In the introduction of this work the phosphodiesterase 7 (PDE7) characterization and an overview of the known inhibitors of this isozyme, from the different chemical groups, as potential therapeutic agents in neurodegenerative diseases and immune disorders were presented. Particular attention has been paid to a new class of dual inhibitors of PDE4/7 PDE7/8 and PDE7/GSK-3 which presented synergistic mechanism of action. The search for compounds of this type is a new research strategy, which aims to increase efficiency, extend the scope of therapeutic applications and decrease side effects. The aim of this study was to design and synthesis of amide and N-arylidenehydrazide derivatives of 1,3-dimethyl-2,3,6,7-tetrahydro-1 H-purine-2,6-dione as possible dual inhibitors of PDE4/7. The experimental part presents a multi-step synthesis and physicochemical properties designed amide (series I, II) and N-arylidenehydrazide (series III, IV) derivatives of 1,3-dimethyl-2,3,6,7-tetrahydro-1H-purine-2,6-dione having in the 8-position the alkylamine moiety (series I, III) or arylmethylamine (series II, IV). The structure of the new synthesized compounds (13 intermediates and 18 final products) were confirmed by the 1 H NMR spectral analysis, the molecular weight was confirmed by LC/MS,. and their purity was determined by UPLC. The new synthesized compounds were submitted to pharmacological tests to determine their ability to inhibit PDE4B PDE7 and in vitro assays

PK/PD Modeling of the PDE7 Inhibitor - GRMS-55 in a Mouse Model of Autoimmune Hepatitis

This study aimed to assess the efficacy and explore the mechanisms of action of a potent phosphodiesterase (PDE)7A and a moderate PDE4B inhibitor GRMS-55 in a mouse model of autoimmune hepatitis (AIH). The concentrations of GRMS-55 and relevant biomarkers were measured in the serum of BALB/c mice with concanavalin A (ConA)-induced hepatitis administered with GRMS-55 at two dose levels. A semi-mechanistic PK/PD/disease progression model describing the time courses of measured biomarkers was developed. The emetogenicity as a potential side effect of the studied compound was evaluated in the α2-adrenoceptor agonist-induced anesthesia model. The results indicate that liver damage observed in mice challenged with ConA was mainly mediated by TNF-α and IFN-γ. GRMS-55 decreased the levels of pro-inflammatory mediators and the transaminase activities in the serum of mice with AIH. The anti-inflammatory properties of GRMS-55, resulting mainly from PDE7A inhibition, led to a high hepatoprotective activity in mice with AIH, which was mediated by an inhibition of pro-inflammatory signaling. GRMS-55 did not induce the emetic-like behavior. The developed PK/PD/disease progression model may be used in future studies to assess the potency and explore the mechanisms of action of new investigational compounds for the treatment of AIH

Analgesis and anti-inflammatory activity of new analogs of HC-030031 : a TRPA1 channel antagonist

One of our study direction is research in the group of compounds affecting the TRPA1 ion channel (Transient receptor potential cation channel, subfamily A, member 1) which can perform an important function in pain (including neuropathic pain) and inflammation for example in asthma and other chronic respiratory diseases. The aim of this study was to evaluate the analgesic and anti-inflammatory activity of two analogs of HC- 030031 analogs belonging to nitrogen derivatives of the heterocyclic system: xanthine (compound 1) and benzimidazole (compound 2) with hydrazide and amide moieties respectively. In this paper, for two derivatives (compound 1 and compound 2) potential analgesic and anti-inflammatory/anti-edematous activities were evaluated in animal models of pain in mice (writhing response test, formalin test) and inflammation in rats (carrageenan- induced paw edema test). Both the tested compounds 1 and 2 showed significant analgesic and antiinflammatory activities

Pharmacokinetic/Pharmacodynamic evaluation of a new purine-2,6-dione derivative in rodents with experimental autoimmune diseases

Current treatment strategies of autoimmune diseases (ADs) display a limited efficacy and cause numerous adverse effects. Phosphodiesterase (PDE)4 and PDE7 inhibitors have been studied recently as a potential treatment of a variety of ADs. In this study, a PK/PD disease progression modeling approach was employed to evaluate effects of a new theophylline derivative, compound 34, being a strong PDE4 and PDE7 inhibitor. Activity of the studied compound against PDE1 and PDE3 in vitro was investigated. Animal models of multiple sclerosis (MS), rheumatoid arthritis (RA), and autoimmune hepatitis were utilized to assess the efficacy of this compound, and its pharmacokinetics was investigated in mice and rats. A new PK/PD disease progression model of compound 34 was developed that satisfactorily predicted the clinical score-time courses in mice with experimental encephalomyelitis that is an animal model of MS. Compound 34 displayed a high efficacy in all three animal models of ADs. Simultaneous inhibition of PDE types located in immune cells may constitute an alternative treatment strategy of ADs. The PK/PD encephalomyelitis and arthritis progression models presented in this study may be used in future preclinical research, and, upon modifications, may enable translation of the results of preclinical investigations into the clinical settings