Sy Duong-Quy

Serum CC chemokine ligand-18 predicts lung disease worsening in systemic sclerosis

Elevated serum CC chemokine ligand (CCL)18 reflects lung fibrosis activity in systemic sclerosis (SSc) and could be an early marker of lung function worsening. Therefore, we sought to evaluate whether serum CCL18 levels at baseline could predict worsening of lung disease in SSc. In this prospective study, 83 SSc patients were analysed longitudinally over a 4-yr observation period for the risk of occurrence of combined deleterious events, defined as a 10% decrease from baseline of total lung capacity or forced vital capacity % predicted, or death, according to serum CCL18 at inclusion. Receiver operating characteristic (ROC) curve analysis was performed for prediction of events during the first year after inclusion. The best cut-off level of serum CCL18 for prediction of a combined event within the follow-up period was 187 ng·mL−1, with 53% sensitivity and 96% specificity (area under the ROC curve 0.86; p<0.001). After a mean±sd follow-up of 33.7±10.8 months, a higher rate of disease progression occurred in the group with serum CCL18 levels >187 ng·mL−1. The adjusted hazard ratio was 5.36 (95% CI 2.44–11.75; p<0.001). In summary, serum CCL18 is an accurate predictive biomarker for the identification of patients with a higher risk of subsequent scleroderma lung disease worsening.

Severity of scleroderma lung disease is related to alveolar concentration of nitric oxide

The alveolar concentration of exhaled nitric oxide (CA,NO) is increased in patients with systemic sclerosis (SSc), but whether this increase is related to the severity of interstitial lung disease (ILD) in SSc has not yet been investigated. In total, 58 SSc patients prospectively underwent pulmonary function tests (PFTs), echocardiogram and fibrosis scoring on pulmonary computed tomography (CT). Patients were divided into two groups according to the presence (or not) of ILD. Measurements of CA,NO were assessed in all SSc patients and compared with those obtained in 19 healthy volunteers. Relationships were sought between CA,NO PFTs and CT scan fibrosis scores. Overall, CA,NO was significantly increased in SSc patients (median (range) 6.2 (3.8–9.9)u2005ppb) as compared with controls (2.0 (1.2–3.0)u2005ppb). Among SSc patients, CA,NO was significantly higher in patients with ILD compared with patients without ILD (nu200a=u200a33, 7.5 (5.2–11.9)u2005ppb versus nu200a=u200a25, 4.9 (3.1–7.0)u2005ppb, respectively). CA,NO was inversely related to total lung capacity (ru200a=u200au2009−0.34) and the diffusing capacity of the lung for carbon monoxide (ru200a=u200au2009−0.37) and was directly related to CT scan fibrosis scores (ru200a=u200a0.36). An increased alveolar concentration of exhaled nitric oxide could, at least in part, either reflect or contribute to the severity of lung disease and could be used to noninvasively assess the extent of interstitial lung disease in systemic sclerosis.

Alveolar concentration of nitric oxide predicts pulmonary function deterioration in scleroderma

Background Respiratory failure is a life-threatening and unpredictable complication of systemic sclerosis (SSc). A study was undertaken to assess the value of alveolar nitric oxide (NO) in predicting the risk of lung function deterioration leading to respiratory failure or death in patients with SSc. Methods 105 patients with SSc were enrolled in this prospective cohort and were followed longitudinally over a 3-year period during which the risk of occurrence of deleterious events was analysed according to alveolar concentration (CAno), conducting airway output (J′awno) and fractional concentration (FEno0.05) of exhaled NO measured at inclusion. Comparison was made between each NO parameter to predict the occurrence of deleterious events, defined as a 10% decrease in total lung capacity or forced vital capacity from baseline, or death. Results The area under the receiver operating characteristic curve of CAno to predict the occurrence of the combined events was 0.84 (95% CI 0.76 to 0.92; p<0.001), which was significantly higher than those of J′awno and FEno0.05 (p<0.001). A cut-off of CAno of 5.3u2005ppb had a sensitivity of 88% and a specificity of 62% for the prediction of the occurrence of combined events during follow-up, and was validated in an independent cohort of patients with SSc. Combined events occurred more frequently in patients whose CAno was >5.3u2005ppb. The adjusted HR for patients with CAno >5.3u2005ppb was 6.06 (95% CI 2.36 to 15.53; p<0.001). CAno accurately predicted the occurrence of combined events irrespective of forced vital capacity values or the presence of interstitial lung disease at baseline. Conclusions Increased CAno accurately identifies patients with SSc with a high risk of developing lung function deterioration and may help to initiate early appropriate treatment.

Role of Rho-kinase and its inhibitors in pulmonary hypertension.

Pulmonary hypertension (PH) is an incurable disease with a dreadful survival rate. The disease is characterized by sustained vasoconstriction, progressive vascular remodeling, and irreversible right heart dysfunction. While hypoxic pulmonary vasoconstriction (HPV) is known to be the main pathophysiological factor causing the rise in pulmonary arterial pressure, biological mechanisms leading to HPV and vascular remodeling are multiple and complex and, as yet, incompletely understood. It is thought that molecular interactions and cross talks are involved in the pathogenesis of PH, perturbing the physiological balance between substances controlling vascular tone, cell growth and apoptosis. This balance is achieved by subtle interactions between factors acting as both vasodilators and inhibitors of cell growth like nitric oxide, prostacyclin, vasoactive intestinal peptide and molecules with potent vasoconstrictor and cell growth activities like endothelin-1. Recent in vivo studies showed that the Rho GTPase/RhoA pathway and its downstream effectors, the Rho-kinases (ROCK-1 and ROCK-2), had an important role in PH, due to its lasting effects on vasoconstriction and pulmonary cell proliferation leading to vascular remodeling. Beneficial effects obtained in vivo with Rho-kinase inhibitors (e.g.Y-27632 and fasudil) in experimental PH will hopefully lead to future clinical trials with new compounds selectively targeting this pathway, which is now proven to be detrimental when over-activated in both experimental animals and human patients.

Long-term treatment with fasudil improves bleomycin-induced pulmonary fibrosis and pulmonary hypertension via inhibition of Smad2/3 phosphorylation

Pulmonary hypertension (PH) associated with pulmonary fibrosis (PF) considerably worsens prognosis of interstitial lung diseases (ILD). RhoA/Rho-kinases (ROCK) pathway is implicated in high pulmonary vascular tone and pulmonary fibrosis but the effect of ROCK inhibitors on PH associated with PF is not known. We therefore aimed to determine whether long-term treatment with fasudil, a selective ROCK inhibitor, could attenuate PF and PH induced by bleomycin in mice. Male C57BL/6 mice received a single dose of intratracheal bleomycin (3.3 U/kg) to induce PF. Treatment with fasudil (30 mg kg(-1) day(-1)) was given intraperitoneally for 7, 14 or 21 days until mice underwent hemodynamic measurements. Right ventricular systolic pressure (RVSP) and RV/(LV + S) ratio were assessed. Lung inflammatory cells profiles, including macrophages, neutrophils, lymphocytes B and lymphocytes T were assessed by immunohistochemistry. Lung fibrosis was evaluated by histological and biochemical methods. Pulmonary arteriole muscularization and medial wall thickness (MWT) were evaluated by immunohistochemical staining for α-SMA. Bleomycin induced severe PF and PH in mice, associated with an increased RhoA/ROCK activity in the lung. Fasudil reduced lung inflammation and lung collagen content, and attenuated the increased RVSP, RV hypertrophy, and pulmonary vascular remodeling in bleomycin-intoxicated mice. Fasudil inhibited the increased activity of RhoA/ROCK pathway, and partly altered bleomycin-associated activation of TGF-β1/Smad pathway, via inhibition of Smad2/3 phosphorylation. The efficacy of long-term treatment with fasudil suggests that the blockade of RhoA/ROCK pathway may be a promising therapy for patients with ILD-associated PH.

Inhaled NO prevents hyperoxia-induced white matter damage in neonatal rats

White matter damage (WMD) and bronchopulmonary dysplasia (BPD) are the two main complications occurring in very preterm infants. Inhaled nitric oxide (iNO) has been proposed to promote alveolarization in the developing lung, and we have reported that iNO promotes myelination and induces neuroprotection in neonatal rats with excitotoxic brain damage. Our hypothesis is that, in addition to its pulmonary effects, iNO may be neuroprotective in rat pups exposed to hyperoxia. To test this hypothesis, we exposed rat pups to hyperoxia, and we assessed the impact of iNO on WMD and BPD. Rat pups were exposed to either hyperoxia (80% FiO2) or to normoxia for 8 days. Both groups received iNO (5 ppm) or air. We assessed the neurological and pulmonary effects of iNO in hyperoxia-injured rat pups using histological, molecular and behavioral approaches. iNO significantly attenuated the severity of hyperoxia-induced WMD induced in neonatal rats. Specifically, iNO decreased white matter inflammation, cell death, and enhanced the density of proliferating oligodendrocytes and oligodendroglial maturation. Furthermore, iNO triggered an early upregulation of P27kip1 and brain-derived growth factor (BDNF). Whereas hyperoxia disrupted early associative abilities, iNO treatment maintained learning scores to a level similar to that of control pups. In contrast to its marked neuroprotective effects, iNO induced only small and transient improvements of BPD. These findings suggest that iNO exposure at low doses is specifically neuroprotective in an animal model combining injuries of the developing lung and brain that mimicked BPD and WMD in preterm infants.

Exhaled nitric oxide, but not serum nitrite and nitrate, is a marker of interstitial lung disease in systemic sclerosis

Nitric oxide metabolites (NOx) in serum, and alveolar concentration of NO (CA(NO)), are markers of inflammation and alveolitis, respectively, in systemic sclerosis (SSc). We prospectively evaluated the usefulness of both NOx and CA(NO) to assess lung involvement and skin fibrosis in SSc. Serum NOx, and CA(NO) measured by two different methods, namely the two-compartment (2CM) and the trumpet models (TM), were concomitantly assessed in 65 patients with SSc and 17 healthy controls. Whilst serum NOx remained comparable between groups, CA(NO) were significantly higher in SSc patients (n=65, 6.7ppb; 4.8-9.7 and 5.9ppb; 3.9-8.9) as compared with controls (n=17, 3.0ppb; 2.0-3.8 and 1.8ppb; 1.1-2.9, p<0.001, p<0.001) using the 2CM and the TM, respectively). CA(NO) from SSc patients with interstitial lung disease (ILD) (n=26, 8.6ppb; 6.5-10.9 and 8.5ppb; 5.9-10.7) or pulmonary arterial hypertension (n=12, 7.3ppb; 6.5-10.4 and 6.9ppb; 5.4-9.9) were significantly higher as compared with patients without ILD (n=27, 4.9ppb; 3.8-6.5 and 4.7ppb; 2.8-5.7; p<0.001 and p<0.001) using the 2CM and the TM, respectively). CA(NO) assessed either by the 2CM or the trumpet model were directly related to the extent of ILD and inversely related to DLCO. There was no correlation between NOx and ILD, or DLCO. Neither CA(NO) nor NOx was correlated with skin fibrosis and no relationship was found between CA(NO) and NOx. Alveolar concentration of NO, but not serum NOx, closely correlates with the extent of ILD in patients with systemic sclerosis. Neither parameter, however, is related to skin fibrosis.

Increased Rho-kinase expression and activity and pulmonary endothelial dysfunction in smokers with normal lung function

Endothelial dysfunction is one of the main consequences of the toxic effects of cigarette smoke on the vascular system. Increasing evidence suggests that the small G-protein RhoA and its downstream effectors, the Rho-kinases (ROCKs), are involved in systemic endothelial dysfunction induced by cigarette smoke. This study aimed to evaluate the role of the RhoA/ROCKs pathway in pulmonary artery endothelial function in current smokers with normal lung function. Lung tissues were obtained from nonsmokers and smokers who underwent lobectomy for lung carcinoma. Arterial relaxation in response to acetylcholine (ACh) was assessed in isolated pulmonary arterial rings. Protein expressions and activities of endothelial nitric oxide synthase (eNOS), ROCKs and the myosin phosphatase subunit 1 (MYPT-1) were sought. Relaxation in response to ACh was significantly lower in smokers as compared with nonsmokers (n = 8 in each group), consistent with reduced eNOS activity in the former compared with the latter. eNOS protein expression remained, however, the same in both groups. Expression of ROCKs, guanosine triphosphate-RhoA and phosphorylated MYPT-1 were significantly increased in smokers compared with controls. Pulmonary endothelial dysfunction is present in smokers whose lung function has not yet been impaired. Reduced activity of eNOS accounts at least in part for this endothelial dysfunction. Increased expression and activity of ROCKs accounts for another part through direct or indirect inhibition of the Rho-A/ROCKs pathway on nitric oxide synthesis and sustained pulmonary vasoconstriction through inhibition of myosin phosphatase.

Activation of RhoA/Rho‐kinase pathway accounts for pulmonary endothelial dysfunction in patients with chronic obstructive pulmonary disease

Recent evidence suggests that activation of RhoA/Rho‐kinase accounts for systemic and pulmonary endothelial dysfunction in smokers with normal lung function. However, its role in patients with chronic obstructive pulmonary disease (COPD) has not yet been investigated. The aim of this study was to evaluate the regulation of RhoA/Rho‐kinase pathway and pulmonary endothelial dysfunction in patients with COPD. Pulmonary arteries were obtained from nonsmokers (control subjects) and patients with nonhypoxemic and hypoxemic COPD (n = 6–7/group). Endothelium‐dependent and ‐independent relaxations were evaluated by acetylcholine and sodium nitroprusside, respectively. Gene and protein expressions of endothelial nitric oxide synthase (eNOS) were measured by RT‐PCR, Western blot, and immunohistochemistry. Nitrate, cGMP, and endothelin‐1 (ET‐1) concentrations, as well as Rho‐kinase activity were measured by ELISA. Protein expressions of total RhoA and GTP‐RhoA were measured by Western blot and pull‐down assay, respectively. Endothelium‐dependent relaxation, and nitrate and cGMP levels were significantly reduced in pulmonary arteries of COPD patients as compared with control subjects. Conversely, activity of RhoA/Rho‐kinase was increased in pulmonary arteries of COPD patients as compared with control subjects. In patients with COPD, pulmonary endothelial dysfunction was related to the downregulation of eNOS activity and upregulation of RhoA/Rho‐kinase activity.

Increased alveolar concentration of nitric oxide is related to serum-induced lung fibroblast proliferation in patients with systemic sclerosis.

Objective. Lung inflammation is present in patients with systemic sclerosis (SSc) and interstitial lung disease (ILD), but the mechanisms linking inflammatory and fibrotic processes in ILD are unknown. Our aim was to investigate whether alveolar inflammation, reflected by increased alveolar concentration of exhaled nitric oxide (CANO), is related to the ability of serum from patients with SSc to induce pulmonary fibroblast proliferation (PFP) and myofibroblast conversion. Methods. CANO was measured in all subjects (37 patients with SSc and 10 healthy controls) whose sera were used to stimulate PFP (assessed by BrdU labeling index) and myofibroblast conversion (detected by α-smooth muscle actin expression). The PFP index in patients with SSc was compared to control values, and between patients with SSc who had elevated (> 4.3 ppb) and normal (≤ 4.3 ppb) CANO values. Results. Both CANO and the PFP index were significantly greater in patients with SSc compared to controls. In patients with SSc, the PFP index was directly related to CANO levels (r = 0.48; p = 0.002). The median PFP index was significantly higher in patients with SSc who had elevated CANO (> 4.3 ppb; n = 25, median 1.1, range 0.98–1.23) than in patients with SSc who had normal CANO (≤ 4.3 ppb; n = 12, median 0.93, range 0.82–1.08; p = 0.01). Similarly, myofibroblast conversion induced by SSc serum was significantly greater in patients with CANO > 4.3 ppb than in patients whose CANO was ≤ 4.3 ppb (p < 0.001) and controls (p < 0.001). Conclusion. Alveolar inflammation reflected by increased nitric oxide production was related to serum-induced PFP and myofibroblast conversion, linking the active alveolitis process to cell proliferation and lung fibrosis in patients with SSc.