Discovery and Pharmacological Characterization of a Novel Small Molecule Antagonist of Integrin α4β1: Focus on Antiallergic Activity

Allergy is a common hypersensitivity disorder that affects 15% to 20% of the population and its prevalence is increasing worldwide. Its severity correlates with the degree of eosinophil infiltration into the conjunctiva, which is mediated by chemokines that stimulate the production of adhesion molecules like intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) on the endothelial cell surface. The α4β1 and α4β7 integrins are expressed in eosinophils and contribute to their activation and infiltration in AC through the binding to VCAM-1 or fibronectin, expressed on vascular endothelial cells. Blockade of α4 integrins might be a therapeutical achievement in allergic eye diseases. DS 70, that show an IC50 in the nanomolar range against α4β1 integrin in Jurkat cells and in the eosinophilic cell line EOL-1. This compound was able to prevent cell adhesion to VCAM-1 and FN in vitro. In a scintillation proximity assay DS70 displaced 125I-FN binding to human α4β1 integrin and, in flow cytometry analysis, it antagonized the binding of a primary antibody to α4β1 integrin expressed on the Jurkat cells surface as well. Furthermore, we analysed also its effects on integrin α4β1 signalling. In an vivo model of allergic conjunctivitis, topical DS70 reduced the clinical aspects of EPR (early phase reaction) and LPR (late phase reaction), by reducing clinical score, eosinophil accumulation, mRNA levels of cytochines and chemochines pro-inflammatory and the conjunctival expression of α4 integrin. In conclusion, DS70 seems a novel antiallergic ocular agent that has significant effects on both early and late phases of ocular allergy.

Balloon pulmonary angioplasty in chronic thromboembolic pulmonary hypertension: experience of four years in a single centre

Background: Balloon pulmonary angioplasty (BPA) has recently been developed as an alternative and less- invasive treatment strategy for chronic thromboembolic pulmonary hypertension (CTEPH), but therapeutic efficacy and technical safety of the technique have to be established. Aim: effects of BPA on patients with inoperable disease or residual pulmonary hypertension (PH) after pulmonary endarterectomy (PEA). Methods: From June 2015 to September 2019 we enrolled symptomatic (NYHA ≥ II) inoperable CTEPH patients and patients with residual PH after PEA. At baseline, immediately before the first BPA session and 3-6 months after last BPA session all patients underwent clinical evaluation, six-minute walking distance and right heart catheterization. For comparisons Friedman test (with Bonferroni post-hoc pairwise analysis) was used. Survival curves were done with Kaplan Meier method. Results: Forty-seven patients [male 45%, median age 68 (51-74) years, 40 inoperable and 7 with residual PH after PEA] were treated for a total of 136 sessions (median number of sessions for each patient: 2); during each session we treated 2 (2-3) vessels; BPA significantly improved symptoms (NYHA III-IV from 85 to 42%), exercise capacity (from 425 to 446 m) and hemodynamic profile (reduction of mean pulmonary arterial pressure from 41 to 35 mmHg and of pulmonary vascular resistance from 7.1 to 4.7 WU). Five pulmonary artery dissection and 2 hemoptysis with clinical impairment were documented; 33 patients had lung injury (radiographic opacity with/without hemoptysis and/or hypoxemia), 7 patients had access site complications. Five patients died during follow-up (none within 30 days from the procedure) because of sepsis (1), heart failure (1), cancer (1), arrhythmic storm (1) and sudden death in a patient with severe coronary atherosclerosis (1). Conclusions: BPA is a safe and effective treatment able to improve symptoms and hemodynamic profile in inoperable CTEPH patients and in patients with residual PH after PEA.