Chronic obstructive pulmonary disease (COPD) is an inflammatory lung pathology characterized by persistent airflow limitation and is the third leading cause of death globally. COPD pathophysiology includes both environmental and host risk factors and the presence of comorbidities contributes to its harmful outcome. Cardiovascular disease (CVD) is closely related to COPD and their coexistence is associated with worse outcomes than either condition alone. COPD impairs the cardiovascular system favoring mostly endothelial dysfunction that is a significant COPD prognostic factor at different stages of the disease. The mechanisms promoting endothelial dysfunction in the systemic and/or pulmonary circulation of COPD patients are different and include systemic inflammation, alteration of adhesion and pro-inflammatory molecules, oxidative stress, cellular senescence, and apoptosis. Nevertheless, the role of endothelium in the onset and progression of COPD and CVD is not yet fully understood. Hence, the purpose of this narrative review is to analyze the literature and provide evidence supporting the importance of endothelial dysfunction in COPD.

Nintedanib is an anti-fibrotic medication endowed with a multi-kinase inhibitor profile and approved for the treatment of Idiopathic Pulmonary Fibrosis (IPF). Nintedanib is believed to inhibit mainly Vascular Endothelial Growth Factor (VEGF), Platelet-Derived Growth Factor (PDGF), and Fibroblast Growth Factor (FGF) receptor kinases. The main objective was to identify potential tissue and/or circulating biomarkers to demonstrate Nintedanib’s target engagement and support its in vivo pharmacodynamic activity, consistent with its proposed mechanism(s) of action. In four independent experiments of bleomycin (BLM)-induced lung fibrosis model in rats, animals received Nintedanib (oral, 100 mg/kg/day) from day 7 post-BLM for 3 weeks. As expected, Nintedanib significantly reduced lung weight, the levels of lung fibrotic markers, and fibrotic areas. Moreover, Nintedanib-treated animals expressed lower levels of FGF2 in lung homogenates and higher plasma and lung levels of VEGF (≥3-fold, p < 0.05) compared to control animals. Lung proteomic analysis revealed the inhibition of receptor tyrosine kinases signaling in Nintedanib-treated animals. Circulating and lung levels of Nintedanib confirmed an optimal tissue distribution in the rat, consistent with the data reported for humans. Although VEGF ligand levels are elevated in the lungs of Nintedanib-treated animals, the VEGF signaling pathway remained functionally downregulated, strongly suggesting compensatory VEGF feedback delivery to its receptor blockade by Nintedanib. In summary, based on the present experimental findings in rats and supporting clinical preliminary evidence, increased VEGF levels can be reasonably considered an indicator of target engagement for Nintedanib and potentially for other VEGF modulators.

Infantile hemangiomas (IHs) are benign vascular neoplasms of childhood (prevalence 5–10%) due to the abnormal proliferation of endothelial cells. IHs are characterized by a peculiar natural life cycle enclosing three phases: proliferative (≤12 months), involuting (≥13 months), and involuted (up to 4–7 years). The mechanisms underlying this neoplastic disease still remain uncovered. Twenty-seven IH tissue specimens (15 proliferative and 12 involuting) were subjected to hematoxylin and eosin staining and a panel of diagnostic markers by immunohistochemistry. WT1, nestin, CD133, and CD26 were also analyzed. Moreover, CD31^pos/CD26^pos proliferative hemangioma–derived endothelial cells (Hem-ECs) were freshly isolated, exposed to vildagliptin (a DPP-IV/CD26 inhibitor), and tested for cell survival and proliferation by MTT assay, FACS analysis, and Western blot assay. All IHs displayed positive CD31, GLUT1, WT1, and nestin immunostaining but were negative for D2-40. Increased endothelial cell proliferation in IH samples was documented by ki67 labeling. All endothelia of proliferative IHs were positive for CD26 (100%), while only 10 expressed CD133 (66.6%). Surprisingly, seven involuting IH samples (58.3%) exhibited coexisting proliferative and involuting aspects in the same hemangiomatous lesion. Importantly, proliferative areas were characterized by CD26 immunolabeling, at variance from involuting sites that were always CD26 negative. Finally, in vitro DPP-IV pharmacological inhibition by vildagliptin significantly reduced Hem-ECs proliferation through the modulation of ki67 and induced cell cycle arrest associated with the upregulation of p21 protein expression. Taken together, our findings suggest that CD26 might represent a reliable biomarker to detect proliferative sites and unveil non-regressive IHs after a 12-month life cycle.

Generalized lymphatic anomaly (GLA) is a congenital, non-neoplastic vascular anomaly characterized by diffuse or multifocal involvement and infiltration of multiple organs. Most GLA cases harbor “hotspot” somatic missense single nucleotide mutations in the PIK3CA gene, whereas a minority involve mutations in other genes. Recently, rapamycin and its homologs have shown encouraging results in the treatment of alterations affecting the PI3K/AKT/mTOR pathway. Therefore, the present work aimed to expand the immunophenotypic characterization of the lymphatic lesion at the tissue level and to evaluate the in vitro viability, migration, and angiogenic capacity of endothelial cells freshly isolated from a PIK3CA-mutated GLA sample, following treatment with alpelisib, rapamycin, dactolisib, and buparlisib. We detected the p.Gln546Lys amino acid substitution in the PI3Kca helical domain in GLA-derived endothelial cells. Then, by immunohistochemical analysis, we documented altered expression of mTOR and its well-characterized downstream substrates, which regulate growth, proliferation, migration, angiogenesis, and survival of ECs. Finally, pharmacological treatment reduced GLA-EC functional properties and down-modulated the hyperactivated PI3K downstream substrates. Overall, our results suggest that routine immunohistochemistry, integrated with phospho-protein analysis and next-generation sequencing, might improve histopathological classification of vascular anomalies and facilitate the development of personalized targeted therapies, particularly in recurrent or surgically challenging cases.

Background: Chronic Obstructive Pulmonary Disease (COPD) is a progressive, incurable condition marked by irreversible airflow limitation and systemic inflammation. Cardiovascular comorbidities, particularly pulmonary hypertension (PH), exacerbate disease severity. While cigarette smoke is a well-known trigger, non-smoking-related inflammatory pathways remain underexplored. This study investigates vascular remodeling in a murine model of inflammation induced by chronic exposure to house dust mite Farinae (HDM). Methods: Female C57BL/6 mice were sensitized with HDM in Freund’s Complete Adjuvant and challenged intranasally with HDM for six weeks. Lung inflammation, mucus hypersecretion, and vascular remodeling were evaluated via BAL, histology, immunofluorescence, echocardiography, gene expression, proteomics, and FlexiVent pulmonary function tests (FlexiVent system). Results: HDM exposure induced a mixed inflammatory response, with elevated neutrophils, monocytes, and lymphocytes in BALF. Mucus hyperproduction (increase in MUC5AC/MUC5B) and impaired lung function (reduced FEV0.1/FVC) were observed. Vascular remodeling was evidenced by increased wall thickness, α-SMA expression, and collagen deposition. Proteomic analysis revealed dysregulation of endothelial markers and protease/antiprotease imbalance. HIF1-α was significantly upregulated in lung tissue and correlated with vascular and epithelial remodeling. Conclusions: Chronic HDM exposure in mice recapitulates key features observed in subsets of COPD and PH, including inflammation-driven airway and vascular remodeling. HIF1-α emerges as a central regulator, linking hypoxia to structural changes. This model offers insights into the effect of non-smoking-related inflammatory pathways on bronchial and vascular remodeling that are potentially relevant for subgroups of COPD patients and highlights HIF1-α as a potential therapeutic target.

Idiopathic pulmonary fibrosis (IPF) remains a progressive and fatal disease despite major advances in antifibrotic therapy. Pirfenidone and nintedanib slow lung function decline, and the PDE4B inhibitor nerandomilast and treprostinil have recently shown promise as next-generation treatments. However, current therapies neither halt nor reverse disease progression, and tolerability issues often limit adherence. We compared the antifibrotic activity and plasma levels of nintedanib administered by either oral gavage or dietary supplementation in a rat model of pulmonary fibrosis. Male Sprague-Dawley rats received intratracheal bleomycin (1 U/kg) on days 0 and 4. From day 7 to day 28, animals were treated with nintedanib (100 mg/kg/day) by either oral gavage or medicated chow. Lung weight, fibrosis biomarkers (procollagen-I, metalloproteinase-7 or MMP7, WNT1-inducible signaling pathway protein or WISP-1), epithelial injury marker KL-6, target engagement biomarkers (Fibroblast Growth Factor 2 or FGF-2, Vascular Endothelial Growth Factor or VEGF), plasma drug levels, and histological fibrosis scores were evaluated. Both administration regimens significantly reduced procollagen-I, WISP-1 and KL-6, and histological fibrosis scores. Oral gavage produced approximately fourfold-higher peak plasma concentrations of nintedanib 30 min after dosing, whereas dietary administration resulted in lower, more stable plasma levels with reduced variability while resulting in comparable antifibrotic efficacy. In conclusion, nintedanib retained robust antifibrotic activity when administered via dietary supplementation despite lower, but continuous, active plasma concentrations. Collectively, these findings indicate that optimizing drug delivery and absorption kinetics may achieve sustained therapeutic efficacy while reducing unnecessary exposure to supratherapeutic concentrations, thereby potentially improving tolerability.