Development of nintedanib nanosuspension for inhaled treatment of experimental silicosis.

Silicosis is an irreversible and progressive fibrotic lung disease caused by massive inhalation of crystalline silica dust at workplaces, affecting millions of industrial workers worldwide. A tyrosine kinase inhibitor, nintedanib (NTB), has emerged as a potential silicosis treatment due to its inhibitory effects on key signaling pathways that promote silica-induced pulmonary fibrosis. However, chronic and frequent use of the oral NTB formulation clinically approved for treating other fibrotic lung diseases often results in significant side effects. To this end, we engineered a nanocrystal-based suspension formulation of NTB (NTB-NS) possessing specific physicochemical properties to enhance drug retention in the lung for localized treatment of silicosis via inhalation. Our NTB-NS formulation was prepared using a wet-milling procedure in presence of Pluronic F127 to endow the formulation with nonadhesive surface coatings to minimize interactions with therapy-inactivating delivery barriers in the lung. We found that NTB-NS, following intratracheal administration, provided robust anti-fibrotic effects and mechanical lung function recovery in a mouse model of silicosis, whereas a 100-fold greater oral NTB dose given with a triple dosing frequency failed to do so. Importantly, several key pathological phenotypes were fully normalized by NTB-NS without displaying notable local or systemic adverse effects. Overall, NTB-NS may open a new avenue for localized treatment of silicosis and potentially other fibrotic lung diseases.

Mitochondria-Rich Fraction Isolated From Mesenchymal Stromal Cells Reduces Lung and Distal Organ Injury in Experimental Sepsis.

OBJECTIVES: To ascertain whether systemic administration of mitochondria-rich fraction isolated from mesenchymal stromal cells would reduce lung, kidney, and liver injury in experimental sepsis. DESIGN: Animal study. SETTING: Laboratory investigation. SUBJECTS: Sixty C57BL/6 male mice. INTERVENTIONS: Sepsis was induced by cecal ligation and puncture; sham-operated animals were used as control. At 24 hours after surgery, cecal ligation and puncture and Sham animals were further randomized to receive saline or mitochondria-rich fraction isolated from mesenchymal stromal cells (3 × 106) IV. At 48 hours, survival, peritoneal bacterial load, lung, kidney, and liver injury were analyzed. Furthermore, the effects of mitochondria on oxygen consumption rate and reactive oxygen species production of lung epithelial and endothelial cells were evaluated in vitro. MEASUREMENTS AND MAIN RESULTS: In vitro exposure of lung epithelial and endothelial cells from cecal ligation and puncture animals to mitochondria-rich fraction isolated from mesenchymal stromal cells restored oxygen consumption rate and reduced total reactive oxygen species production. Infusion of exogenous mitochondria-rich fraction from mesenchymal stromal cells (mitotherapy) reduced peritoneal bacterial load, improved lung mechanics and histology, and decreased the expression of interleukin-1ß, keratinocyte chemoattractant, indoleamine 2,3-dioxygenase-2, and programmed cell death protein 1 in lung tissue, while increasing keratinocyte growth factor expression and survival rate in cecal ligation and puncture-induced sepsis. Mitotherapy also reduced kidney and liver injury, plasma creatinine levels, and messenger RNA expressions of interleukin-18 in kidney, interleukin-6, indoleamine 2,3-dioxygenase-2, and programmed cell death protein 1 in liver, while increasing nuclear factor erythroid 2-related factor-2 and superoxide dismutase-2 in kidney and interleukin-10 in liver. CONCLUSIONS: Mitotherapy decreased lung, liver, and kidney injury and increased survival rate in cecal ligation and puncture-induced sepsis.

Niclosamide attenuates lung vascular remodeling in experimental pulmonary arterial hypertension.

Despite advances in medical therapy, pulmonary arterial hypertension (PAH) remains an inexorably progressive and highly lethal disease. Signal transducer and activator of transcription (STAT)-3 is one of the main intracellular transcription factors implicated in PAH vascular remodeling. We hypothesized that niclosamide, a STAT3 inhibitor, would reduce vascular remodeling in an established pulmonary arterial hypertension model, thus enhancing cardiac function. Male Wistar rats were treated either with monocrotaline (60 mg/kg), to induce PAH, or saline (C group) by intraperitoneal injection. On day 14, PAH animals were randomly assigned to receive oral (1) saline (PAH-SAL); (2) niclosamide (75 mg/kg/day) (PAH-NICLO); (3) sildenafil (20 mg/kg/day) (PAH-SIL); or (4) niclosamide + sildenafil (PAH-NICLO + SIL), once daily for 14 days. On day 28, right ventricular systolic pressure was lower in all treated groups compared to PAH-SAL. Pulmonary vascular collagen content was lower in PAH-NICLO (37 ± 3%) and PAH-NICLO + SIL (37 ± 6%) compared to PAH-SAL (68 ± 4%), but not in PAH-SIL (52 ± 1%). CD-34, an endothelial cell marker, was higher, while vimentin, a mesenchymal cell marker, was lower in PAH-NICLO and PAH-NICLO + SIL compared to PAH-SAL, suggesting attenuation of endothelial-mesenchymal transition. Expression of STAT3 downstream targets such as transforming growth factor (TGF)-ß, hypoxia-inducible factor (HIF)-1, and provirus integration site for Moloney murine leukemia virus (PIM-1) in lung tissue was reduced in PAH-NICLO and PAH-NICLO + SIL compared to PAH-SAL. In conclusion, niclosamide, with or without sildenafil, mitigated vascular remodeling and improved right ventricle systolic pressure. This new role for a well-established drug may represent a promising therapy for PAH.

Effects of the FGF receptor-1 inhibitor, infigratinib, with or without sildenafil, in experimental pulmonary arterial hypertension.

BACKGROUND AND PURPOSE: Pulmonary arterial hypertension (PAH) is a progressive disease associated with high morbidity and mortality, despite advances in medical therapy. We compared the effects of infigratinib (NVP-BGJ398), a new FGF receptor-1 inhibitor, with or without the PDE-5 inhibitor sildenafil, on vascular function and remodelling as well as on gene expression of signal transducers for receptors of TGF-ß (Smads-1/2/4) and transcription factor of endothelial-mesenchymal transition (Twist-1) in established experimental PAH. Types I and III pro-collagen and TGF-ß expressions in lung fibroblasts were analysed in vitro after the different treatments. EXPERIMENTAL APPROACH: PAH was induced in male Wistar rats with monocrotaline. 14 days later, treatments [sildenafil (SIL), infigratinib (INF) or their combination (SIL+INF)] were given for another 14 days. On Day 28, echocardiography and haemodynamic assays were performed, and lungs and pulmonary vessels were removed for analysis by histology, immunohistochemistry and RT-PCR. Fibroblasts prepared from PAH lungs were also analysed for TGF-ß and pro-collagen. KEY RESULTS: Only the combination of infigratinib and sildenafil significantly improved right ventricular systolic pressure and vascular remodelling parameters (right ventricular hypertrophy, smooth muscle α-actin, vessel wall thickness, and vascular collagen content). Infigratinib may act by reducing gene expression of Smads-1/4 and Twist-1 in lung tissue, as well as TGF-ß and types I and III pro-collagen in lung fibroblasts. CONCLUSIONS AND IMPLICATIONS: In this model of monocrotaline-induced PAH, the combination of the new inhibitor of FGF receptor-1, infigratinib, and sildenafil effectively improved haemodynamics and decreased vascular remodelling.