Inhibition of Bruton's Tyrosine Kinase Alleviates Monocrotaline-Induced Pulmonary Arterial Hypertension by Modulating Macrophage Polarization.

Macrophage accumulation and activation contribute to the development of pulmonary arterial hypertension (PAH), while Bruton's tyrosine kinase (BTK) is an important regulator for the activation and polarization of macrophage. However, the role of BTK in PAH remains unknown. In the present study, a selective BTK inhibitor (BTKi) BGB-3111 was applied to investigate the role of BTK in monocrotaline- (MCT-) induced PAH rat and phorbol myristate acetate- (PMA-) differentiated U937 macrophages. Our results showed that BTK was mainly distributed and upregulated in CD68+ macrophages in the lungs of PAH rats. Daily treated with BTKi BGB-3111 alleviated MCT-induced PAH, as indicated by the decrease in right ventricular systolic pressure (RVSP), attenuation in right ventricle hypertrophy and pulmonary vascular remodeling, reduction in perivascular collagen deposition, as well as inhibition of inflammation and endothelial-to-mesenchymal transition (EndMT) in the lung. Moreover, BTK inhibition suppressed MCT-induced recruitment of macrophages, especially the classical activated macrophages (M1) in the lung. In vitro, BGB-3111 significantly suppressed lipopolysaccharide- (LPS-) induced M1 polarization and proinflammatory cytokine production in U937-derived macrophages. The underlying mechanism is associated with the inhibition of NF-κB/MAPK pathways and nucleotide-binding oligomerization domain-like receptor with pyrin domain 3 (NLRP3) inflammasome activation. Furthermore, macrophage conditioned medium (CM) from LPS-induced M1 macrophages promoted migration and EndMT of HPAECs, while CM from BGB-3111-pretreated LPS-induced M1 macrophages failed to induce this response. These findings suggest that BTK inhibition alleviates PAH by regulating macrophage recruitment and polarization and may be a potential therapeutic strategy for the treatment of PAH.

Soluble ST2 in serum predicts the prognosis of idiopathic pulmonary fibrosis: a retrospective study.

Background: Idiopathic pulmonary fibrosis (IPF) is a heterogeneous and progressive fibrosing interstitial lung disease with a poor prognosis. However, there are currently no effective biomarker that can reliably predict the prognosis for IPF in clinic. The serum level of soluble suppression of tumorigenicity-2 (sST2), which is involved in the immune response, has proven to be a prognostic predictor for various diseases. Previous studies have confirmed that the immune dysfunction plays an important role in the pathogenesis of IPF and the serum sST2 concentrations in patients with IPF are elevated. However, the relationship between sST2 and the prognosis of IPF remains unknown. Methods: A total of 83 patients with IPF and 20 healthy controls from 2016 to 2021 were enrolled and demographic variables, indices of lung function testing as well as the biomarkers including the sST2 were obtained at baseline. During follow-up, the primary endpoint was defined as all-cause death and clinical deterioration. Cox hazard models and Kaplan-Meier method were used to assess the prognostic value of various indices including sST2. Results: Mean duration of follow-up was 29 months, during which 49 patients had an event, and of them, 35 patients died. The sST2 level was higher in the IPF patients compared with the healthy controls. Although the sST2 level did not directly predict all-cause death in the present study, it was proved to be an independent predictor of event-free survival. Multivariate forward stepwise model which was adjusted by age, sex, and body surface area (BSA) showed that the overexpression of sST2 increased the hazard ratio [1.005, 95% confidence interval (CI): 1.001-1.010]. A higher sST2 serum level heralded more deterioration and the poor outcomes. Moreover, the effect of sST2 on the prognosis of IPF may not necessarily involve the development of IPF-related pulmonary hypertension (PH). Conclusions: In our study, the sST2 serum level was significantly elevated and a higher serum level of sST2 predicted more deterioration and poor outcomes in patients with IPF. Thus, sST2 can serve as a valuable prognostic biomarker for the outcome of IPF. However, further multicenter clinical trials of larger sample size are needed in the future.

Integrin ß1 in Pancreatic Cancer: Expressions, Functions, and Clinical Implications.

Pancreatic cancer (PC) is characterized by rapid progression and a high mortality rate. The current treatment is still based on surgical treatment, supplemented by radiotherapy and chemotherapy, and new methods of combining immune and molecular biological treatments are being explored. Despite this, the survival rate of PC patients is still very disappointing. Therefore, clarifying the molecular mechanism of PC pathogenesis and developing precisely targeted drugs are key to improving PC prognosis. As the most common ß subunit of the integrin family, integrin ß1 has been proved to be closely related to the vascular invasion, distant metastasis, and survival of PC patients, and treatment targeting integrin ß1 in PC has gained initial success in animal models. In this review, we summarize the various signaling pathways by which integrins are involved in PC, focusing on the roles of integrin ß1 in the malignant behaviors of PC. Additionally, recent studies regarding the feasibility of integrin ß1 as a diagnostic and prognostic biomarker in PC are also discussed. Finally, we present the progress of several integrin ß1-based clinical trials to highlight the potential of integrin ß1 as a target for personalized therapy in PC.

Icotinib Attenuates Monocrotaline-Induced Pulmonary Hypertension by Preventing Pulmonary Arterial Smooth Muscle Cell Dysfunction.

BACKGROUND: Aberrant activation of epidermal growth factor receptor (EGFR) signaling pathway is associated with the pathogenesis of pulmonary hypertension (PH). However, the effect of icotinib, a first generation of EGFR tyrosine kinase inhibitor (EGFR-TKI), on PH remains to be elucidated. METHODS: PH rat model was established by a single intraperitoneal injection of monocrotaline (MCT, 60 mg/kg). Icotinib (15, 30, and 60 mg/kg/day) was administered by oral gavage from the day of MCT injection. After 4 weeks, hemodynamic parameters and histological changes of the pulmonary arterial vessels were assessed, and the phenotypic switching of pulmonary arterial smooth muscle cells (PASMCs) was determined in vivo. Moreover, the effects of icotinib (10 µM) on epidermal growth factor (EGF, 50 ng/ml)-stimulated proliferation, migration, and phenotypic switching of human PASMCs were explored in vitro. RESULTS: Icotinib significantly reduced the right ventricular systolic pressure and right ventricle hypertrophy index in rats with MCT-induced PH. Moreover, icotinib improved MCT-induced pulmonary vascular remodeling. The expression of contractile marker (smooth muscle 22 alpha (SM22α)) and synthetic markers (osteopontin (OPN) and vimentin) in pulmonary artery was restored by icotinib treatment. In vitro, icotinib suppressed EGF-induced PASMCs proliferation and migration. Meanwhile, icotinib inhibited EGF-induced downregulation of α-smooth muscle actin and SM22α and upregulation of OPN and Collagen I in PASMCs, suggesting that icotinib could inhibit EGF-induced phenotypic switching of PASMCs. Mechanistically, these effects of icotinib were associated with the inhibition of EGFR-Akt/ERK signaling pathway. CONCLUSIONS: Icotinib can attenuate MCT-induced pulmonary vascular remodeling and improve PH. This effect of icotinib might be attributed to preventing PASMC dysfunction by inhibiting EGFR-Akt/ERK signaling pathway.

Paeoniflorin Ameliorates Chronic Hypoxia/SU5416-Induced Pulmonary Arterial Hypertension by Inhibiting Endothelial-to-Mesenchymal Transition.

BACKGROUND: Endothelial cells dysfunction is one of the hallmark pathogenic features of pulmonary arterial hypertension (PAH). Paeoniflorin (PF) is a monoterpene glycoside with endothelial protection, vasodilation, antifibrotic, anti-inflammatory and antioxidative properties. However, the effects of PF on PAH remain unknown. METHODS: Here, we investigated the efficacy of PF in the SU5416/hypoxia (SuHx) rat model of PAH. Human pulmonary arterial endothelial cells (HPAECs) were exposed to 1% O2 with or without PF treatment. RESULTS: Hemodynamics analysis showed that prophylactic treatment with PF (300 mg/kg i.g. daily for 21 days) significantly inhibited chronic hypoxia/SU5416-induced elevations of right ventricular systolic pressure (RVSP) and right ventricular hypertrophy index in rats. Meanwhile, PF significantly reduced pulmonary vascular remodeling, as well as alleviated collagen deposition in lungs and right ventricles in SuHx rats. Additionally, PF inhibited SuHx-induced down-regulation of endothelial marker (vascular endothelial cadherin) and up-regulation of mesenchymal markers (fibronectin and vimentin) in lung, suggesting that PF could inhibit SuHx-induced endothelial-to-mesenchymal transition (EndMT) in lung. Further in vitro studies confirmed that PF treatment suppressed hypoxia-induced EndMT in HPAECs, which was abolished by the knockdown of bone morphogenetic protein receptor type 2 (BMPR2) in HPAECs. CONCLUSION: Taken together, our findings suggest that PF ameliorates BMPR2 down-regulation-mediated EndMT and thereafter alleviates SuHx-induced PAH in rats.