Giovanni Vitulli

Expression analysis of brain-derived neurotrophic factor (BDNF) mRNA isoforms after chronic and acute antidepressant treatment

The neurotrophin brain-derived neurotrophic factor (BDNF) is considered to be a key factor for neuronal survival, differentiation and plasticity. According to a proposed hypothetical model BDNF expression might play a central role in the pathogenesis of depression. The BDNF gene is rather complex in its structure and it can express four different mRNA isoforms by alternative splicing, each producing the same protein. This might reflect fine tuning of gene regulation by different signalling networks. Since the BDNF gene has been reported to be upregulated by antidepressants, the expression of the four BDNF mRNA isoforms was measured by real-time quantitative RT-PCR in rat hippocampi after chronic and acute treatment with the antidepressant drug fluoxetine and GR205171, a selective NK-1 receptor antagonist with anxiolytic-like properties. The aim of this study was to test the hypothesis of differential regulation of the mRNA isoforms by those compounds. Our results indicate that the expression of BDNF mRNA isoforms is not affected by chronic or acute treatment with fluoxetine or GR205171.

Synthesis and pharmacological characterisation of 2,4-Dicarboxy-pyrroles as selective non-Competitive mGluR1 antagonists

Metabotropic glutamate receptors (mGluRs) are an unusual family of G-protein coupled receptor (GPCR), and are characterised by a large extracellular N-terminal domain that contains the glutamate binding site. We have identified a new class of non-competitive metabotropic glutamate receptor 1 (mGluR1) antagonists, 2,4-dicarboxy-pyrroles which are endowed with nanomolar potency. They interact within the 7 transmembrane (7TM) domain of the receptor and show antinociceptive properties when tested in a number of different animal models.

Cyclopenta[d]pyrimidines and Dihydropyrrolo[2,3‐d]pyrimidines as Potent and Selective Corticotropin‐Releasing Factor 1 Receptor Antagonists

Two new classes of potent and selective CRF1 receptor antagonists are presented. Exploration of general templates 3 and 4 through modifications of the top amine and bottom phenyl substituents led to optimization of the in vitro affinity and pharmacokinetic profiles. The typical alkyl chains present in the top region of CRF1 antagonists were replaced by substituted heteroaryl moieties, leading to a dramatic improvement of the metabolic stability. This improvement was apparent when the compounds were dosed in vivo: several compounds exhibited low plasma clearance, good oral bioavailability, and high brain penetration. As a consequence of their outstanding pharmacokinetic profiles, these CRF1 antagonists, as exemplified by compound 4 fi (4‐(4‐bromo‐3‐methyl‐1H‐pyrazol‐1‐yl)‐7‐(2,4‐dichlorophenyl)‐2‐methyl‐6,7‐dihydro‐5H‐pyrrolo[2,3‐d]pyrimidine), produced a dose‐dependent “anxiolytic‐like” effect when administered orally, decreasing the vocalization of rat pups.

Effect of the TRPV1 antagonist SB-705498 on the nasal parasympathetic reflex response in the ovalbumin sensitized guinea pig.

Nasal sensory nerves play an important role in symptoms associated with rhinitis triggered by environmental stimuli. Here, we propose that TRPV1 is pivotal in nasal sensory nerve activation and assess the potential of SB‐705498 as an intranasal therapy for rhinitis.

Heteroaryl-substituted 4-(1H-pyrazol-1-yl)-5,6-dihydro-1H-pyrrolo[2,3-d]pyrimidine derivatives as potent and selective corticotropin-releasing factor receptor-1 antagonists.

Heteroaryl-Substituted 4-(1H-pyrazol-1-yl)-5,6-dihydro-1H-pyrrolo[2,3-d]pyrimidine Derivatives as Potent and Selective CorticotropinReleasing Factor Receptor-1 Antagonists Fabio Maria Sabbatini,* Romano Di Fabio,* Yves St-Denis, Anna-Maria Capelli, Emiliano Castiglioni, Stefania Contini, Daniele Donati, Elettra Fazzolari, Gabriella Gentile, Fabrizio Micheli, Francesca Pavone, Marilisa Rinaldi, Alessandra Pasquarello, Maria Grazia Zampori, Pina Di Felice, Paola Zarantonello, Roberto Arban, Benedetta Perini, Giovanni Vitulli, Roberto Benedetti, Beatrice Oliosi, and Angela Worby

Molecular clinical safety intelligence: a system for bridging clinically focused safety knowledge to early-stage drug discovery - the GSK experience.

Drug toxicity is a major cause of late-stage product attrition. During lead identification and optimization phases little information is typically available about which molecules might have safety concerns. A system was built linking chemistry, preclinical and human safety information, enabling scientists to lever safety knowledge across multiple disciplines. The system consists of a data warehouse with chemical structures and chemical and biological properties for ∼80000 compounds and tools to access and analyze clinical data, toxicology, in vitro pharmacology and drug metabolism data. Tapping into this safety knowledge enables rapid clinically focused risk assessments of drug candidates. Use of this strategy adds value to the drug discovery process at GSK via efficient triage of compounds based on their potential for toxicity.

Discovery of (S)-3-(3-(3,5-Dimethyl-1H-pyrazol-1-yl)phenyl)-4-((R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)pyrrolidin-1-yl)butanoic Acid, a Nonpeptidic αvβ6 Integrin Inhibitor for the Inhaled Treatment of Idiopathic Pulmonary Fibrosis

A series of 3-aryl(pyrrolidin-1-yl)butanoic acids were synthesized using a diastereoselective route, via a rhodium catalyzed asymmetric 1,4-addition of arylboronic acids in the presence of ( R)-BINAP to a crotonate ester to provide the ( S) absolute configuration for the major product. A variety of aryl substituents including morpholine, pyrazole, triazole, imidazole, and cyclic ether were screened in cell adhesion assays for affinity against αvβ1, αvβ3, αvβ5, αvβ6, and αvβ8 integrins. Numerous analogs with high affinity and selectivity for the αvβ6 integrin were identified. The analog ( S)-3-(3-(3,5-dimethyl-1 H-pyrazol-1-yl)phenyl)-4-(( R)-3-(2-(5,6,7,8-tetrahydro-1,8-naphthyridin-2-yl)ethyl)pyrrolidin-1-yl)butanoic acid hydrochloride salt was found to have very high affinity for αvβ6 integrin in a radioligand binding assay (p Ki = 11), a long dissociation half-life (7 h), very high solubility in saline at pH 7 (>71 mg/mL), and pharmacokinetic properties commensurate with inhaled dosing by nebulization. It was selected for further clinical investigation as a potential therapeutic agent for the treatment of idiopathic pulmonary fibrosis.

LSC - 2017 - Targeting glucose metabolism in experimental lung injury and fibrosis

Introduction: Akin to many cancers, enhanced18F-FDG-PET signal has been associated with fibrotic lesions in pulmonary fibrosis. In tumors, elevated glucose uptake is indicative of a metabolic switch to aerobic glycolysis (AG), critical to fuel biosynthetic demand. De novo expression of the low-activity isoform of the ‘glycolytic gatekeeper’ pyruvate kinase, PKM2, is a key driver of AG and pharmacological modulation of PKM2 is known to attenuate tumor proliferation and tumorigenesis. Aim: We hypothesised that the fibroproliferative response to bleomycin lung injury is characterised by metabolic reprogramming driving an enhanced glucose requirement of cells in the injured lesions. We investigated glucose uptake and modulation of the glycolytic marker PKM2 in the bleomycin mouse model. Methods&Results: Autoradiography of18F-FDG uptake in cryofrozen lung sections at day 28 post-bleomycin showed a significant ›50% increase in18F-FDG uptake in bleomycin-challenged compared to uninjured lungs. The regions of highest18F-FDG uptake corresponded to dense fibrotic regions. Immunohistochemistry revealed that PKM2 was localised to multiple cell types in fibrotic lung lesions, including a-SMA-positive myofibroblasts. A small molecule activator of PKM2, TEPP-46, achieved a significant ~50% increase in PKM2 activity in the bleomycin-injured lung. However, chronic TEPP-46 administration from day 5 post-injury had no significant effect on lung fibrosis quantified by microCt at day 28. Conclusions: We show that glucose uptake is significantly increased in fibrotic lung lesions. Although fibrotic lesions express PKM2, increasing the activity of this isoform was not sufficient to influence progression of fibrosis in bleomycin lung injury