Characterization of proximal pulmonary arterial cells from chronic thromboembolic pulmonary hypertension patients

<p>Abstract</p> <p>Background</p> <p>Chronic thromboembolic pulmonary hypertension (CTEPH) is associated with proximal pulmonary artery obstruction and vascular remodeling. We hypothesized that pulmonary arterial smooth muscle (PASMC) and endothelial cells (PAEC) may actively contribute to remodeling of the proximal pulmonary vascular wall in CTEPH. Our present objective was to characterize PASMC and PAEC from large arteries of CTEPH patients and investigate their potential involvement in vascular remodeling.</p> <p>Methods</p> <p>Primary cultures of proximal PAEC and PASMC from patients with CTEPH, with non-thromboembolic pulmonary hypertension (PH) and lung donors have been established. PAEC and PASMC have been characterized by immunofluorescence using specific markers. Expression of smooth muscle specific markers within the pulmonary vascular wall has been studied by immunofluorescence and Western blotting. Mitogenic activity and migratory capacity of PASMC and PAEC have been investigated <it>in vitro</it>.</p> <p>Results</p> <p>PAEC express CD31 on their surface, von Willebrand factor in Weibel-Palade bodies and take up acetylated LDL. PASMC express various differentiation markers including α-smooth muscle actin (α-SMA), desmin and smooth muscle myosin heavy chain (SMMHC). In vascular tissue from CTEPH and non-thromboembolic PH patients, expression of α-SMA and desmin is down-regulated compared to lung donors; desmin expression is also down-regulated in vascular tissue from CTEPH compared to non-thromboembolic PH patients. A low proportion of α-SMA positive cells express desmin and SMMHC in the neointima of proximal pulmonary arteries from CTEPH patients. Serum-induced mitogenic activity of PAEC and PASMC, as well as migratory capacity of PASMC, were increased in CTEPH only.</p> <p>Conclusions</p> <p>Modified proliferative and/or migratory responses of PASMC and PAEC <it>in vitro</it>, associated to a proliferative phenotype of PASMC suggest that PASMC and PAEC could contribute to proximal vascular remodeling in CTEPH.</p

Role of inflammation in the pathophysiology of chronic thromboembolic pulmonary hypertension

Chronic thromboembolic pulmonary hypertension is a rare and life-threatening disorder characterized by unresolved thromboemboli associated with fibrous stenosis in large proximal pulmonary arteries. Knowledge of the causing factors and pathophysiology remains incomplete. Based on our recent observation that CTEPH patients display increased plasma levels of C-reactive protein (CRP), a maker of inflammation, we aimed to investigate the role of inflammation in the pathophysiology of CTEPH and more specifically the role of CRP. First, we evaluated the morphometry and cellular content of proximal arterial lesions of CTEPH patients and analysed the pattern of systemic inflammatory mediators. We evidenced the presence of neointima, thrombotic, recanalized and atherosclerotic lesions. An accumulation and infiltration of inflammatory cells and correlations between local accumulation of inflammatory cells and circulating inflammatory markers suggests a link between systemic and local inflammation, which could contribute to the progression of CTEPH. Second, we extensively characterized EC and SMC from proximal pulmonary arteries from CTEPH patients. We observed a proliferative phenotype of SMC, indicated by a down-regualtion of desmin, a marker of late differentiation, and modified proliferative and/or migratory responses of SMC and EC in vitro. This suggests that SMC and EC could contribute to proximal vascular remodeling in CTEPH. Next, we found that CRP was able to enhance SMC mitogenic activity, inflammatory cell adhesion to EC, secretion of ET-1 and vWF by EC from CTEPH patients and therefore might contribute to vascular remodeling, thrombosis and endothelial dysfunction. We also found a local expression of CRP in EC and SMC within the pulmonary vascular wall. The scavenger receptor LOX-1 was overexpressed in pulmonary arteries of CTEPH patients. We found a differential expression of NF&#954;B pathway-related genes in CRP-activated CTEPH-EC and an inhibition of NF&#954;B pathway in cell culture assays impaired CRP-induced EC adhesive capacities and dysfunction, suggesting that the NF&#954;B pathway could mediate the effects of CRP on CTEPH pulmonary vascular cells. Finally, we showed that the ET-1 receptor antagonists bosentan and sitaxsentan dose-dependantly inhibit the mitogenic activity of proximal CTEPH-, PH- and donor-SMC. We can conclude that using different approaches, including measurement of plasma inflammatory mediators, primary human cell culture, molecular biology and immunofluorescence, we have evidenced that inflammation could play a key role in the pathophysiology of CTEPH.status: publishe

Contribution of inflammation and impaired angiogenesis to the pathobiology of chronic thromboembolic pulmonary hypertension

Deficient angiogenesis and systemic inflammation could be involved in the pathophysiology of chronic thromboembolic pulmonary hypertension (CTEPH). We aimed to characterise the histopathology of pulmonary vascular lesions from 52 CTEPH patients who underwent a pulmonary endarterectomy (PEA) and investigate a potential link between clinical, biological and morphometric parameters.Collagen, elastin, fibrin, lipid, endothelial, smooth muscle and inflammatory cell content was investigated using immunohistochemistry. Qualitative changes were evaluated using severity scores. Circulating levels of inflammatory mediators were measured using ELISA.Neointima, thrombotic, recanalised and atherosclerotic lesions were found. Accumulation of macrophages, T-lymphocytes and neutrophils was found mainly in atherosclerotic and thrombotic lesions. Angiogenesis was observed in all kinds of lesions; low-scored angiogenesis predicted adverse outcome, including persistent pulmonary hypertension post-PEA, start of medical therapy and poor survival. C-reactive protein (CRP), interleukin-10, monocyte chemotactic protein-1, macrophage inflammatory protein-1α and matrix metalloproteinase (MMP)-9 were significantly elevated in CTEPH patients. Plasma CRP and MMP-9 levels correlated with neutrophil and macrophage accumulation, respectively.Enhanced systemic inflammation parallels local inflammatory cell infiltration in major pulmonary arteries at advanced stages of CTEPH. Impaired neovascularisation is associated with poor survival, start of medical treatment and persistent pulmonary hypertension post-PEA. These findings suggest that inflammation and impaired angiogenesis could contribute to the progression of the disease.status: publishe

Multiplex protein profiling of bronchoalveolar lavage in idiopathic pulmonary fibrosis and hypersensitivity pneumonitis

Context: Idiopathic pulmonary fibrosis (IPF) and chronic hypersensitivity pneumonitis (HP) are diffuse parenchymal lung diseases characterized by a mixture of inflammation and fibrosis, leading to lung destruction and finally death. AIMS: The aim of this study was to compare different pathophysiological mechanisms, such as angiogenesis, coagulation, fibrosis, tissue repair, inflammation, epithelial damage, oxidative stress, and matrix remodeling, in both disorders using bronchoalveolar lavage (BAL). Methods: At diagnosis, patients underwent bronchoscopy with BAL and were divided into three groups: Control ( n = 10), HP ( n = 11), and IPF ( n = 11), based on multidisciplinary approach (clinical examination, radiology, and histology): Multiplex searchlight technology was used to analyze 25 proteins representative for different pathophysiological processes: Eotaxin, basic fibroblast growth factor (FGFb), fibronectin, hepatocyte growth factor (HGF), interleukine (IL)-8, IL-12p40, IL-17, IL-23, monocyte chemotactic protein (MCP-1), macrophage-derived chemokine (MDC), myeloperoxidase (MPO), matrix metalloproteinase (MMP)-8, MMP-9, active plasminogen activating inhibitor 1 (PAI-1), pulmonary activation regulated chemokine (PARC), placental growth factor (PlGF), protein-C, receptor for advanced glycation end products (RAGE), regulated on activation normal T cells expressed and secreted (RANTES), surfactant protein-C (SP-C), transforming growth factor-β1 (TGF-β1), tissue inhibitor of metalloproteinase-1 (TIMP-1), tissue factor, thymic stromal lymphopoietin (TSLP), and vascular endothelial growth factor (VEGF). Results: All patients suffered from decreased pulmonary function and abnormal BAL cell differential compared with control. Protein levels were increased in both IPF and HP for MMP-8 ( P = 0.022), MMP-9 ( P = 0.0020), MCP-1 ( P = 0.0006), MDC ( P = 0.0048), IL-8 ( P = 0.013), MPO ( P = 0.019), and protein-C ( P = 0.0087), whereas VEGF was decreased ( P = 0.0003) compared with control. HGF was upregulated in HP ( P = 0.0089) and active PAI-1 was upregulated ( P = 0.019) in IPF compared with control. Differences in expression between IPF and HP were observed for IL-12p40 ( P = 0.0093) and TGF-β1 ( P = 0.0045). Conclusions: Using BAL, we demonstrated not only expected similarities but also important differences in both disorders, many related to the innate immunity. These findings provide new clues for further research in both disorders

Wheelchair-specific fitness of persons with a long-term spinal cord injury: Cross-sectional study on effects of time since injury and physical activity level

Purpose: To study the impact of time since injury (TSI) and physical activity (PA) on fitness of persons with spinal cord injury (SCI). Method: Cross-sectional study. Persons with SCI (N = 158) in three TSI strata: 10-19, 20-29 and ≥30 years after SCI and divided in an active and inactive group. Fitness [peak power output (POpeak) and peak oxygen uptake (VO2peak)] was assessed. Results: In persons with tetraplegia, no significant relationship was found between TSI and fitness after controlling for confounders, while a higher activity level was related to a higher POpeak in this group. Active people with tetraplegia also showed less decline in POpeak with an increase in TSI compared to inactive people. In persons with paraplegia, after controlling for confounders, it was shown that TSI had a negative effect on POpeak, while PA was not significantly associated with fitness in people with paraplegia. Conclusions: In people with paraplegia, fitness was significantly lower in those with a longer TSI. Persons with a long TSI might need more attention to remain fit and PA might be an important element in that respect as shown by the results of the group with a tetraplegia.Implications for RehabilitationWheelchair-specific fitness seems to diminish over time after paraplegia.An active lifestyle is related to wheelchair-specific fitness in persons with tetraplegia.Prevention of long-term deconditioning is very important

Clinical prediction models for mortality in patients with covid-19:external validation and individual participant data meta-analysis

OBJECTIVE: To externally validate various prognostic models and scoring rules for predicting short term mortality in patients admitted to hospital for covid-19. DESIGN: Two stage individual participant data meta-analysis. SETTING: Secondary and tertiary care. PARTICIPANTS: 46 914 patients across 18 countries, admitted to a hospital with polymerase chain reaction confirmed covid-19 from November 2019 to April 2021. DATA SOURCES: Multiple (clustered) cohorts in Brazil, Belgium, China, Czech Republic, Egypt, France, Iran, Israel, Italy, Mexico, Netherlands, Portugal, Russia, Saudi Arabia, Spain, Sweden, United Kingdom, and United States previously identified by a living systematic review of covid-19 prediction models published in The BMJ, and through PROSPERO, reference checking, and expert knowledge. MODEL SELECTION AND ELIGIBILITY CRITERIA: Prognostic models identified by the living systematic review and through contacting experts. A priori models were excluded that had a high risk of bias in the participant domain of PROBAST (prediction model study risk of bias assessment tool) or for which the applicability was deemed poor. METHODS: Eight prognostic models with diverse predictors were identified and validated. A two stage individual participant data meta-analysis was performed of the estimated model concordance (C) statistic, calibration slope, calibration-in-the-large, and observed to expected ratio (O:E) across the included clusters. MAIN OUTCOME MEASURES: 30 day mortality or in-hospital mortality. RESULTS: Datasets included 27 clusters from 18 different countries and contained data on 46 914patients. The pooled estimates ranged from 0.67 to 0.80 (C statistic), 0.22 to 1.22 (calibration slope), and 0.18 to 2.59 (O:E ratio) and were prone to substantial between study heterogeneity. The 4C Mortality Score by Knight et al (pooled C statistic 0.80, 95% confidence interval 0.75 to 0.84, 95% prediction interval 0.72 to 0.86) and clinical model by Wang et al (0.77, 0.73 to 0.80, 0.63 to 0.87) had the highest discriminative ability. On average, 29% fewer deaths were observed than predicted by the 4C Mortality Score (pooled O:E 0.71, 95% confidence interval 0.45 to 1.11, 95% prediction interval 0.21 to 2.39), 35% fewer than predicted by the Wang clinical model (0.65, 0.52 to 0.82, 0.23 to 1.89), and 4% fewer than predicted by Xie et al’s model (0.96, 0.59 to 1.55, 0.21 to 4.28). CONCLUSION: The prognostic value of the included models varied greatly between the data sources. Although the Knight 4C Mortality Score and Wang clinical model appeared most promising, recalibration (intercept and slope updates) is needed before implementation in routine care