N-acylhydrazone derivative ameliorates monocrotaline-induced pulmonary hypertension through the modulation of adenosine AA2R activity

Background

Pulmonary arterial hypertension (PAH) is a disease that results in right ventricular (RV) dysfunction. While pulmonary vascular disease is the primary pathological focus, RV hypertrophy and RV dysfunction are the major determinants of prognosis in PAH. The aim of this study was to investigate the effects of (E)-N′-(3,4-dimethoxybenzylidene)-4-methoxybenzohydrazide (LASSBio-1386), an N-acylhydrazone derivative, on the lung vasculature and RV dysfunction induced by experimental PAH.

Methods

Male Wistar rats were injected with a single dose (60 mg/kg, i.p.) of monocrotaline (MCT) and given LASSBio-1386 (50 mg/kg, p.o.) or vehicle for 14 days. The hemodynamic, exercise capacity (EC), endothelial nitric oxide synthase (eNOS), adenosine A_2A receptor (A_2AR), sarcoplasmic/endoplasmic reticulum calcium ATPase (SERCA2a), phospholamban (PLB) expression, Ca^2 +-ATPase activity and vascular activity of LASSBio-1386 were evaluated.

Results and conclusions

The RV systolic pressure was elevated in the PAH model and reduced from 49.6 ± 5.0 mm Hg (MCT group) to 27.2 ± 2.1 mm Hg (MCT + LASSBio-1386 group; P < 0.05). MCT administration also impaired the EC, increased the RV and pulmonary arteriole size, and promoted endothelial dysfunction of the pulmonary artery rings. In the PAH group, the eNOS, A_2AR, SERCA2a, and PLB levels were changed compared with the control; in addition, the Ca^2 +-ATPase activity was reduced. These alterations were related with MCT-injected rats, and LASSBio-1386 had favorable effects that prevented the development of PAH. LASSBio-1386 is effective at preventing endothelial and RV dysfunction in PAH, a finding that may have important implications for ongoing clinical evaluation of A_2AR agonists for the treatment of PAH.     

Blood biomarkers and their potential role in pulmonary arterial hypertension associated with congenital heart disease. A systematic review

Background

The development of pulmonary arterial hypertension (PAH) in patients with congenital heart disease (CHD) is multifactorial with a number of biomarkers serving as mediators of neurohormonal activation [B-type natriuretic peptide (BNP) and its N-terminal-pro-fragment (NT-proBNP)], endothelial dysfunction [asymmetric dimethylarginine (ADMA)] and cellular proliferation [vascular endothelial growth factor (VEGF)].

Methods

We systematically reviewed the literature for trials studying the role of these biomarkers in the clinical evaluation, prognosis and management of patients with PAH related to CHD (CHD–PAH).

Results

Twenty-six studies were included in the systematic review, involving a total of 1113 patients with CHD–PAH. These patients had higher BNP, NT-proBNP and ADMA levels and higher VEGF expression when compared with healthy controls. Baseline and serial values of plasma levels of natriuretic peptides were shown to be significant predictors of survival. ADMA concentration was elevated in patients with CHD–PAH when compared with patients with simple CHD without PAH, whereas VEGF expression was particularly high in patients with CHD and persistent PAH after corrective surgery of the underlying heart disease.

Conclusion

Right heart dysfunction, endothelial inflammation and proliferation are mirrored by plasma levels of the corresponding biomarkers among patients with CHD–PAH. There is early evidence to suggest that natriuretic peptides, in particular, may be a simple and effective tool for determining prognosis and timing for therapeutic interventions in patients with CHD–PAH.     

S-allyl-l-cysteine attenuates bleomycin-induced pulmonary fibrosis and inflammation via AKT/NF-κB signaling pathway in mice

Idiopathic pulmonary fibrosis (IPF) is a progressive and lethal lung disease characterized by inflammation, multifocal fibrotic lesions and excessive collagen deposition with limited therapies. As a major bioactive compound in garlic, S-allyl-l-cysteine (SAC) is a neuroprotective drug candidate to prevent cognitive decline, however, its anti-pulmonary fibrotic activity remains unknown. Here, we investigated whether SAC could attenuate bleomycin (BLM)-induced pulmonary fibrosis and inflammation in mice. Our results showed that SAC dose-dependently reduced the infiltration of inflammatory cells, pulmonary lesions and collagen deposition in BLM treated mice with downregulated mRNA expression levels of fibrotic genes including alpha smooth muscle actin (α-SMA), fibronectin, collagen I and collagen III as well as the protein level of α-SMA. In addition, SAC could also reduce the mRNA expression of inflammatory mediators such as TNF-α and iNOS. Furthermore, higher phosphorylation of AKT and NF-κB p65 in IPF patient samples and murine samples was verified by immunohistochemistry while SAC could decrease the phosphorylation level of AKT and NF-κB p65 in mice stimulated with BLM. These findings, for the first time, indicate that SAC might mediate AKT/NF-κB signaling pathway to inhibit BLM-induced pulmonary fibrosis and support the potential role of SAC as an anti-pulmonary fibrosis agent.