Elevated Myl9 reflects the Myl9-containing microthrombi in SARS-CoV-2-induced lung exudative vasculitis and predicts COVID-19 severity.

The mortality of coronavirus disease 2019 (COVID-19) is strongly correlated with pulmonary vascular pathology accompanied by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection-triggered immune dysregulation and aberrant activation of platelets. We combined histological analyses using field emission scanning electron microscopy with energy-dispersive X-ray spectroscopy analyses of the lungs from autopsy samples and single-cell RNA sequencing of peripheral blood mononuclear cells to investigate the pathogenesis of vasculitis and immunothrombosis in COVID-19. We found that SARS-CoV-2 accumulated in the pulmonary vessels, causing exudative vasculitis accompanied by the emergence of thrombospondin-1-expressing noncanonical monocytes and the formation of myosin light chain 9 (Myl9)-containing microthrombi in the lung of COVID-19 patients with fatal disease. The amount of plasma Myl9 in COVID-19 was correlated with the clinical severity, and measuring plasma Myl9 together with other markers allowed us to predict the severity of the disease more accurately. This study provides detailed insight into the pathogenesis of vasculitis and immunothrombosis, which may lead to optimal medical treatment for COVID-19.

Suppression of Type I Interferon Signaling in Myeloid Cells by Autoantibodies in Severe COVID-19 Patients.

PURPOSE: Auto-antibodies (auto-abs) to type I interferons (IFNs) have been identified in patients with life-threatening coronavirus disease 2019 (COVID-19), suggesting that the presence of auto-abs may be a risk factor for disease severity. We therefore investigated the mechanism underlying COVID-19 exacerbation induced by auto-abs to type I IFNs. METHODS: We evaluated plasma from 123 patients with COVID-19 to measure auto-abs to type I IFNs. We performed single-cell RNA sequencing (scRNA-seq) of peripheral blood mononuclear cells from the patients with auto-abs and conducted epitope mapping of the auto-abs. RESULTS: Three of 19 severe and 4 of 42 critical COVID-19 patients had neutralizing auto-abs to type I IFNs. Patients with auto-abs to type I IFNs showed no characteristic clinical features. scRNA-seq from 38 patients with COVID-19 revealed that IFN signaling in conventional dendritic cells and canonical monocytes was attenuated, and SARS-CoV-2-specific BCR repertoires were decreased in patients with auto-abs. Furthermore, auto-abs to IFN-α2 from COVID-19 patients with auto-abs recognized characteristic epitopes of IFN-α2, which binds to the receptor. CONCLUSION: Auto-abs to type I IFN found in COVID-19 patients inhibited IFN signaling in dendritic cells and monocytes by blocking the binding of type I IFN to its receptor. The failure to properly induce production of an antibody to SARS-CoV-2 may be a causative factor of COVID-19 severity.

Effects of Surgical and Medical Treatment on Quality of Life for Patients With Chronic Thromboembolic Pulmonary Hypertension.

BACKGROUND: This study aimed to investigate the predictors of quality of life (QOL) in patients with chronic thromboembolic pulmonary hypertension (CTEPH), changes in QOL after surgical and medical treatments, and the relationship between baseline QOL and survival. METHODS AND RESULTS: QOL was measured in 128 patients with CTEPH (male/female: 42/86, age: 56±12 years, surgical/medical: 65/63) using the Short-Form 36 (SF-36) questionnaire. Multiple regression analysis showed pulmonary vascular resistance (PVR) and 6-min walking distance (6MWD) were associated with physical functioning (PF) (P<0.01) and physical component summary (PCS) (P<0.01). In the surgical group, 7 subscales and 2 summary scores improved significantly, and in the medical group 6 subscales and the mental component summary, although the change in QOL was greater in the surgical group. The patients in the conventional therapy group with higher PF had significantly better survival than those with lower PF (5-years survival: 89.5% vs. 50.8%, P=0.002). This difference in survival was not observed in the group receiving pulmonary arterial hypertension (PAH)-specific therapy (100% vs. 100%, P=0.746). CONCLUSIONS: PVR and 6MWD were associated with PF or PCS in CTEPH patients. QOL improved after surgical or medical therapy, with a greater change in the surgical group. PAH-specific therapy improved survival in patients with lower PF at diagnosis.

Association of plasma fibrinogen and plasminogen with prognosis of inoperable chronic thromboembolic pulmonary hypertension.

BACKGROUND: It is unclear whether abnormalities of coagulation or fibrinolysis are associated with disease progression of chronic thromboembolic pulmonary hypertension (CTEPH). The aim of this study was to investigate the association of these factors with the severity and prognosis of CTEPH. METHODS AND RESULTS: Between 1986 and 2011, plasma fibrinogen and plasminogen were measured in 89 of 106 consecutive patients with inoperable CTEPH (17 men; mean age, 55.9±14.1 years old; mean pulmonary arterial pressure, 44.0±12.4 mmHg) and the association of level with severity and prognosis were also examined. Seventeen patients had high fibrinogen and low plasminogen (medians, ≥291 mg/dl and <101%, respectively). These patients had significantly lower cardiac index (2.26±0.68 vs. 2.70±0.57 L·min(-1)·m(-2), P=0.007), higher pulmonary vascular resistance (PVR; 13.29±7.54 vs. 9.15±4.14 Wood units, P=0.003), and poor survival (5-year survival, 35.3% vs. 88.0%, P<0.001) compared to the other 72 patients. Additional analysis showed significantly poor survival in these patients compared with the other patients who did not have modern therapy. On multivariate analysis plasma fibrinogen, plasminogen and PVR were independent predictors of survival in medically treated patients. CONCLUSIONS: High plasma fibrinogen and low plasminogen are associated with poor survival in CTEPH patients without modern therapy.

Improved survival in medically treated chronic thromboembolic pulmonary hypertension.

BACKGROUND: The surgical indication for chronic thromboembolic pulmonary hypertension (CTEPH) has been modified due to recognition of peripheral type CTEPH and changes in surgical methods and skill. Bosentan and sildenafil are used as modern oral therapy (mod Tx) in patients with inoperable CTEPH, although it remains unknown whether they have positive effects on survival. METHODS AND RESULTS: A total of 202 patients were diagnosed with CTEPH at Chiba University Hospital between 1986 and 2010, 100 of whom underwent pulmonary endarterectomy. Seven medically treated patients with pulmonary vascular resistance (PVR) ≤ 300 dyn·s·cm(-5) were regarded as having mild disease. Survival rate was stratified by date of diagnosis (group 1, 1986-1998; group 2, 1999-2004; group 3, 2005-2010), and prognostic factors in the remaining 95 medically treated patients were investigated. Group 3 included the most patients treated with mod Tx (group 1, 9.1%; group 2, 24.2%; group 3, 65.0%) and had significantly better survival than either group 1 or 2 (5-year survival: group 1, 54.6%; group 2, 69.7%; group 3, 87.3%). Patients receiving mod Tx had significantly better survival than those not on mod Tx (5-year survival: 88.9% vs. 60.2%). Multivariate analysis showed that mod Tx, lower PVR, and lack of comorbidity were significant predictors of better outcome. CONCLUSIONS: Medically treated patients with CTEPH had a better survival rate, and the use of mod Tx contributed to improved survival.

CD40 amplifies Fas-mediated apoptosis: a mechanism contributing to emphysema.

Excessive apoptosis and prolonged inflammation of alveolar cells are associated with the pathogenesis of pulmonary emphysema. We aimed to determine whether CD40 affects alveolar epithelial cells and endothelial cells, with regard to evoking apoptosis and inflammation. Mice were repeatedly treated with agonistic-anti CD40 antibody (Ab), with or without agonistic-anti Fas Ab, and evaluated for apoptosis and inflammation in lungs. Human pulmonary microvascular endothelial cells and alveolar epithelial cells were treated with agonistic anti-CD40 Ab and/or anti-Fas Ab to see their direct effect on apoptosis and secretion of proinflammatory molecules in vitro. Furthermore, plasma soluble CD40 ligand (sCD40L) level was evaluated in patients with chronic obstructive pulmonary disease (COPD). In mice, inhaling agonistic anti-CD40 Ab induced moderate alveolar enlargement. CD40 stimulation, in combination with anti-Fas Ab, induced significant emphysematous changes and increased alveolar cell apoptosis. CD40 stimulation also enhanced IFN-γ-mediated emphysematous changes, not via apoptosis induction, but via inflammation with lymphocyte accumulation. In vitro, Fas-mediated apoptosis was enhanced by CD40 stimulation and IFN-γ in endothelial cells and by CD40 stimulation in epithelial cells. CD40 stimulation induced secretion of CCR5 ligands in endothelial cells, enhanced with IFN-γ. Plasma sCD40L levels were significantly increased in patients with COPD, inversely correlating to the percentage of forced expiratory volume in 1 s and positively correlating to low attenuation area score by CT scan, regardless of smoking history. Collectively CD40 plays a contributing role in the development of pulmonary emphysema by sensitizing Fas-mediated apoptosis in alveolar cells and increasing the secretion of proinflammatory chemokines.

Endothelial-like cells in chronic thromboembolic pulmonary hypertension: crosstalk with myofibroblast-like cells.

BACKGROUND: Chronic thromboembolic pulmonary hypertension (CTEPH) is characterized by intravascular thrombus formation in the pulmonary arteries.Recently, it has been shown that a myofibroblast cell phenotype was predominant within endarterectomized tissues from CTEPH patients. Indeed, our recent study demonstrated the existence of not only myofibroblast-like cells (MFLCs), but also endothelial-like cells (ELCs). Under in vitro conditions, a few transitional cells (co-expressing both endothelial- and SM-cell markers) were observed in the ELC population. We hypothesized that MFLCs in the microenvironment created by the unresolved clot may promote the endothelial-mesenchymal transition and/or induce endothelial cell (EC) dysfunction. METHODS: We isolated cells from these tissues and identified them as MFLCs and ELCs. In order to test whether the MFLCs provide the microenvironment which causes EC alterations, ECs were incubated in serum-free medium conditioned by MFLCs, or were grown in co-culture with the MFLCs. RESULTS: Our experiments demonstrated that MFLCs promoted the commercially available ECs to transit to other mesenchymal phenotypes and/or induced EC dysfunction through inactivation of autophagy, disruption of the mitochondrial reticulum, alteration of the SOD-2 localization, and decreased ROS production. Indeed, ELCs included a few transitional cells, lost the ability to form autophagosomes, and had defective mitochondrial structure/function. Moreover, rapamycin reversed the phenotypic alterations and the gene expression changes in ECs co-cultured with MFLCs, thus suggesting that this agent had beneficial therapeutic effects on ECs in CTEPH tissues. CONCLUSIONS: It is possible that the microenvironment created by the stabilized clot stimulates MFLCs to induce EC alterations.

Serum level of fibrinogen Aα chain fragment increases in chronic thromboembolic pulmonary hypertension.

BACKGROUND: The cause of chronic thromboembolic pulmonary hypertension is unknown and there is no specific circulating biomarker for its detection. The aim of the present study was to use proteomic analysis to detect serum biomarkers by evaluating the serum profiles of low-molecular-weight peptides using matrix-assisted laser desorption/ionization time-of-flight/time-of-flight mass spectrometry in patients with chronic thromboembolic pulmonary hypertension. METHODS AND RESULTS: Serum low-molecular-weight peptide profiling using the spectrophotometric technique was studied retrospectively in patients with chronic thromboembolic pulmonary hypertension and in controls matched for sex and age. The serum level of a 2989-Da peptide in the sera of patients was significantly higher compared to that of controls. Tandem mass spectrometry indicated that the peptide was a fragment of fibrinogen Aα chain (KMADEAGSEADHEGTHSTKRGHAKSRPV). The serum level of fibrinogen Aα chain fragment, measured using a heavy isotope internal standard, tended toward negative correlation with plasmin-α2-plasmin inhibitor complex (P=0.073) and had a positive correlation with thrombin-anti-thrombin complex (P=0.031). CONCLUSIONS: This fragment may be a potential diagnostic biomarker for chronic thromboembolic pulmonary hyper-tension.

Inhaled granulocyte/macrophage-colony stimulating factor as therapy for pulmonary alveolar proteinosis.

RATIONALE: Inhaled granulocyte/macrophage-colony stimulating factor (GM-CSF) is a promising therapy for pulmonary alveolar proteinosis (PAP) but has not been adequately studied. OBJECTIVES: To evaluate safety and efficacy of inhaled GM-CSF in patients with unremitting or progressive PAP. METHODS: We conducted a national, multicenter, self-controlled, phase II trial at nine pulmonary centers throughout Japan. Patients who had lung biopsy or cytology findings diagnostic of PAP, an elevated serum GM-CSF antibody level, and a Pa(O(2)) of less than 75 mm Hg entered a 12-week observation period. Those who improved (i.e., alveolar-arterial oxygen difference [A-aDO(2)] decreased by 10 mm Hg) during observation were excluded. The rest entered sequential periods of high-dose therapy (250 microg Days 1-8, none Days 9-14; x six cycles; 12 wk); low-dose therapy (125 microg Days 1-4, none Days 5-14; x six cycles; 12 wk), and follow-up (52 wk). MEASUREMENTS AND MAIN RESULTS: Fifty patients with PAP were enrolled in the study. During observation, nine improved and two withdrew; all of these were excluded. Of 35 patients completing the high- and low-dose therapy, 24 improved, resulting in an overall response rate of 62% (24/39; intention-to-treat analysis) and reduction in A-aDO(2) of 12.3 mm Hg (95% confidence interval, 8.4-16.2; n = 35, P < 0.001). No serious adverse events occurred, and serum GM-CSF autoantibody levels were unchanged. A treatment-emergent correlation occurred between A-aDO(2) and diffusing capacity of the lung, and high-resolution CT revealed improvement of ground-glass opacity. Twenty-nine of 35 patients remained stable without further therapy for 1 year. CONCLUSIONS: Inhaled GM-CSF therapy is safe, effective, and provides a sustained therapeutic effect in autoimmune PAP. Clinical trial registered with www.controlled-trials.com/isrctn (ISRCTN18931678), www.jmacct.med.or.jp/english (JMA-IIA00013).

[A case of pulmonary arteriovenous fistula treated by transcatheter embolization using 320-row multidetector computed tomography].

The patient was a 34-year-old man, who was referred to our hospital because of abnormal shadows in the right lower lung field on a chest radiograph during a medical screening. Chest computed tomography (CT) showed a pulmonary arteriovenous fistula 23 x 17 mm in size in the anterior basal segment of the right lung, together with a single artery and single vein. He had no symptoms and did not have Osler-Weber-Rendu syndrome. Coil embolization was performed in order to decrease the risk of complications associated with right-to-left shunting. Transcatheter embolization using interlocking detachable coils and detachable fibered coils was successfully performed without severe complications. Then, 320-row multidetector CT revealed that the blood flow from the pulmonary artery disappeared just after coil embolization, the blood flow from the pulmonary vein flowed backward, and the fistula was contrasted. The fistula had almost completely disappeared 8 months after embolization. We confirmed that blood flows were interrupted by 320-row CT and pulmonary angiography. 320-row CT was useful for the evaluation of pulmonary arteriovenous fistula and coil embolization.

Susceptibility to chronic thromboembolic pulmonary hypertension may be conferred by miR-759 via its targeted interaction with polymorphic fibrinogen alpha gene.

A deletion/insertion (Del/Ins) polymorphism of 28 base pairs (bp) in the 3' untranslated region (UTR) of fibrinogen alpha gene (FGA) was associated with thromboembolic diseases, but the underlying mechanisms remain unknown. Computational predication reveals that the 28 bp polymorphic fragment is complementary to the sequence of a microRNA, miR-759. In this study, we aim to investigate the association and implicated mechanisms between FGA polymorphisms and the susceptibility to chronic thromboembolic pulmonary hypertension (CTEPH). The Del/Ins polymorphism was analyzed in 190 patients with CTEPH and 628 controls. The FGA 3'UTR and miR-759 interaction was investigated using luciferase assay and quantitative RT-PCR method. Expression of miR-759 and FGA in human tissues was investigated by RT-PCR. The results reveal that the allele frequency of Ins was significantly higher in the patients than in the controls (55.8 vs. 47.1%, P=0.003, odds ratio=1.42, 95% confidence interval: 1.13-1.79). Both miR-759 and FGA were expressed in human liver. Co-transfection of miR-759 decreased the expression and mRNA stability of reporter gene containing the FGA 3'UTR. The effect of miR-759 was stronger on the Ins allele than on the Del allele. These observations suggest that the expression of FGA was regulated by miR-759 through its interaction at the polymorphic 3'UTR sequence, which was associated with the susceptibility to CTEPH.

[Pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension].

The Ministry of Health, Labour and Welfare (Japan) has approved research into primary pulmonary hypertension (PPH) and pulmonary hypertension due to chronic thromboembolic and/or embolic disease (CTE-PH) to examine their epidemiology, pathophysiology, and develop new therapeutic strategies. The Respiratory Failure Research Group, with grant support from the Ministry of Health, Labour and Welfare, changed the diagnostic names of PPH and CTE-PH. The Specific Diseases Control Division in the Health Service Bureau of the Ministry of Health, Labour and Welfare supported our proposal. One of the major purposes of The Respiratory Failure Research Group has been to maintain and, if possible, promote patient quality of life and prognosis in cases of intractable respiratory diseases. The name PPH has been changed to "pulmonary arterial hypertension (PAH)", and the name CTE-PH has been changed to "chronic thromboembolic pulmonary hypertension (CTEPH)", in keeping with recent worldwide research progress in this field. PAH should be subdivided into different pathophysiologic conditions, such as idiopathic and hereditary PAH, PAH associated with connective tissue diseases, portal hypertension, congenital heart disease, persistent pulmonary hypertension in newborn babies, pulmonary veno-occlusive disease etc. Different therapeutic strategies may be adopted for different subgroups. Pulmonary hypertension due to left heart disease, lung disease and/or hypoxia and CTEPH should be excluded from PAH. Continuous monitoring of PAH and CTEPH is required in patients with these conditions, even if the degree of pulmonary hypertension is improved by therapeutic intervention, because these diseases are incurable.

[Successful operative case of chronic thromboembolic pulmonary hypertension clinically diagnosed as bronchial asthma].

We report a case of a 70-year-old man with chronic thromboembolic pulmonary hypertension (CTEPH) in whom bronchial asthma had been clinically diagnosed and treated, and who showed remarkable improvement by pulmonary endarterectomy. He had dyspnea on exertion and had been clinically treated for bronchial asthma for 15 years. However, his symptoms did not improve after oral and inhaled corticosteroid therapy, and he had dyspnea at rest. CTEPH was suspected by echocardiography and computed tomography (CT) and he was admitted to our hospital. Perfusion scans showed multiple segmental perfusion defects with normal ventilation study, and contrast-enhanced CT showed intramural thrombi in both pulmonary arteries. Right cardiac catheterization revealed a mean pulmonary arterial pressure of 70 mm Hg and pulmonary vascular resistance of 1699 dyn.s.cm(-5) with chronic thromboembolic findings on pulmonary angiography. After surgery his pulmonary hemodynamics and symptoms significantly improved. CTEPH is rarely diagnosed at the initial visit because the only symptom is dyspnea on exertion, and it is often misdiagnosed as other respiratory diseases. But it is important to suspect and diagnose CTEPH in patients with unexplained dyspnea because this disease can be cured by surgery.

[Case of thymic carcinoid associated with multiple endocrine neoplasia type I treated effectively with chemotherapy].

A 53-year-old man was referred to our hospital due to a mediastinal mass found during a medical checkup in July 2009. He had a past history of hyperparathyroidism, for which he underwent surgery in 1994, and also had a family history in that his sister had multiple endocrine neoplasia type 1 (MEN1). He was given a diagnosis of MEN I on genetic testing. Chest CT revealed a mediastinal mass 4 cm in maximum dimension, and an atypical carcinoid was diagnosed according to mediastinal biopsy findings. Bone metastasis was detected and he was given cisplatin and etoposide. The tumor decreased in size by 30%, and was evaluated as showing partial response. Although there are some cases of MEN-related thymoma treated by surgery, a case which successfully responded to chemotherapy alone is thought to be extremely rare.

HLA-DPB1 and NFKBIL1 may confer the susceptibility to chronic thromboembolic pulmonary hypertension in the absence of deep vein thrombosis.

Chronic thromboembolic pulmonary hypertension (CTEPH) is characterized by pulmonary hypertension caused by thromboembolism of the pulmonary artery. Etiology of CTEPH may be heterogeneous and is largely unknown, but genetic factors are considered to be involved in the etiology. It has been reported that deep vein thrombosis (DVT) and/or coagulation factor variants are predisposing factors to CTEPH. However, more than half of the CTEPH patients, especially the Japanese, do not have prior DVT or coagulation abnormality, suggesting that there should be other risk factors for CTEPH. Moreover, there are several reports on the association between CTEPH and human leukocyte antigen (HLA). To further clarify the HLA-linked gene(s) controlling the susceptibility to CTEPH, 160 patients (99 without DVT and 61 with DVT) and 380 healthy controls were analyzed for polymorphisms in 15 microsatellite markers and 5 genes in the HLA region. We found a strong association of HLA markers with the DVT-negative CTEPH, DPB1(*)0202 (odds ratio (OR)=5.07, 95% confidence interval (CI)=2.52-10.19, P=0.00000075, corrected P-value (Pc)=0.00014), IKBL-p(*)03 (OR=2.33, 95% CI=1.49-3.66, P=0.00017, Pc=0.033) and B(*)5201 (OR=2.47, 95% CI=1.56-3.90, P=0.000086, Pc=0.016), whereas no significant association was observed for the DVT-positive CTEPH. The comparison of clinical characteristics of patients stratified by the presence of susceptibility genes implied that the DPB1 gene controlled the severity of the vascular lesion, whereas the IKBL gene (NFKBIL1) was associated with a relatively mild phenotype.

Characteristics of a large cohort of patients with autoimmune pulmonary alveolar proteinosis in Japan.

RATIONALE: Acquired pulmonary alveolar proteinosis (PAP) is a syndrome characterized by pulmonary surfactant accumulation occurring in association with granulocyte/macrophage colony-stimulating factor autoantibodies (autoimmune PAP) or as a consequence of another disease (secondary PAP). Because PAP is rare, prior reports were based on limited patient numbers or a synthesis of historical data. OBJECTIVES: To describe the epidemiologic, clinical, physiologic, and laboratory features of autoimmune PAP in a large, contemporaneous cohort of patients with PAP. METHODS: Over 6 years, 248 patients with PAP were enrolled in a Japanese national registry, including 223 with autoimmune PAP. MEASUREMENTS AND MAIN RESULTS: Autoimmune PAP represented 89.9% of cases and had a minimum incidence and prevalence of 0.49 and 6.2 per million, respectively. The male to female ratio was 2.1:1, and the median age at diagnosis was 51 years. A history of smoking occurred in 56%, and dust exposure occurred in 23%; instances of familial onset did not occur. Dyspnea was the most common presenting symptom, occurring in 54.3%. Importantly, 31.8% of patients were asymptomatic and were identified by health screening. Intercurrent illnesses, including infections, were infrequent. A disease severity score reflecting the presence of symptoms and degree of hypoxemia correlated well with carbon monoxide diffusing capacity and serum biomarkers, less well with pulmonary function, and not with granulocyte/macrophage colony-stimulating factor autoantibody levels or duration of disease. CONCLUSIONS: Autoimmune PAP had an incidence and prevalence higher than previously reported and was not strongly linked to smoking, occupational exposure, or other illnesses. The disease severity score and biomarkers provide novel and potentially useful outcome measures in PAP.

Pulmonary Hypertension that Developed During Treatment for Hepatopulmonary Syndrome and Pulmonary Arteriovenous Malformation.

Hepatopulmonary syndrome (HPS) and pulmonary arteriovenous malformation (PAVM) are hypoxemic diseases caused by right-to-left shunting but are rarely concomitant with pulmonary hypertension (PH). A 66-year-old woman with chronic hepatitis C was scheduled to undergo liver transplantation. She was referred to our department for hypoxia and an abnormal shadow in the right lung found on a preoperative examination. She was diagnosed with HPS and a PAVM in the right middle lobe. After liver transplantation, PH temporarily developed, but the pulmonary arterial pressure normalized after coil embolization. Combined HPS and PAVM may cause unique changes in pulmonary hemodynamics during treatment.

VEGF-R blockade causes endothelial cell apoptosis, expansion of surviving CD34+ precursor cells and transdifferentiation to smooth muscle-like and neuronal-like cells.

Severe pulmonary hypertension (PH) is characterized by complex precapillary arteriolar lesions, which contain phenotypically altered smooth muscle (SM) and endothelial cells (EC). We have demonstrated that VEGF receptor blockade by SU5416 {3-[(2,4-dimethylpyrrol-5-yl)methylidenyl]-indolin 2-one} in combination with chronic hypoxia causes severe angioproliferative PH associated with arterial occlusion in rats. We postulate that endothelial-mesenchymal transdifferentiation can take place in the occlusive lesions and that endothelium-derived mesenchymal cells can further differentiate toward a SM phenotype. To examine this hypothesis, we incubated human pulmonary microvascular endothelial cells (HPMVEC) with SU5416 and analyzed these cells utilizing quantitative-PCR, immunofluorescent staining and flow cytometry analysis. In vitro studies in HPMVEC demonstrated that SU5416 suppressed PGI2S gene expression while potently inducing COX-2, VEGF, and TGF-beta1 expression; and caused transdifferentiation of mature vascular endothelial cells (defined by Dil-ac-LDL, Lectin and Factor VIII) to SM-like (as defined by expression of alpha-SM actin) "transitional" cells, coexpressing both endothelial and SM markers. SU5416 expanded the number of CD34 and/or c-kit positive cells and caused transdifferentiation of CD34 positive cells but not negative cells. In conclusion, our data show that SU5416 generated a selection pressure that killed some EC and expanded progenitor-like cells to transdifferentiate to SM-like and neuronal-like cells.

Tiotropium bromide attenuates respiratory syncytial virus replication in epithelial cells.

BACKGROUND: Respiratory syncytial virus (RSV) infection could be related to airway inflammation as well as exacerbation of chronic obstructive pulmonary disease (COPD). Tiotropium bromide decreases the frequency of exacerbation in patients with COPD; however, the mechanisms of tiotropium bromide to reduce the chances of exacerbation have not been defined. One potential mechanism could be that tiotropium bromide protects against RSV infection in epithelial cells. OBJECTIVE: To examine whether tiotropium bromide affects RSV replication in HEp-2 cells. METHODS: The supernatant titer of RSV was calculated by methylcellulose plaque assay after RSV innoculation. Intracellular RSV and ICAM-1 mRNA were measured by PCR. Syncytium formation was observed by light microscopy. Intracellular RSV fusion protein and RhoA protein were detected by Western blot analysis. Furthermore, RhoA activity, ICAM-1 expression and inflammatory cytokines in cultured supernatant were measured by binding assay, immunofluorescence staining and ELISA, respectively. RESULTS: Tiotropium bromide decreased the supernatant titer of RSV, and it inhibited syncytium formation, RhoA activation and ICAM-1 expression. Moreover, it suppressed the production of IL-6 and IL-8 after RSV infection. CONCLUSIONS: The antiviral effects of tiotropium bromide regarding RSV replication are partly due to inhibition of RhoA activity and ICAM-1 expression. Tiotropium bromide decreases RSV replication and may modulate airway inflammation by reducing the production of inflammatory cytokines.

[Case of metachronous mucosa-associated lymphoid tissue (MALT) lymphoma originated from a distinct B-cell clone].

Although mucosa-associated lymphoid tissue (MALT) lymphoma is classified as an indolent lymphoma, it frequently disseminates and recurs to make the disease difficult to cure. The present case had metachronous lesions in the skin, orbit and pleura, and all of them were diagnosed as derived from the same monoclonal tumor cell. A 65-year-old woman was admitted to our hospital because of a pleural tumor with pleural effusion. Two years before, she had undergone surgical resection for skin erythematous lesion and an ocular adnexa tumor, which were diagnosed as lymphoid hyperplasia by histological examination at that time. On admission, thoracoscopy-guided biopsy of the pleural tumor with local anesthesia established a diagnosis of MALT lymphoma. The rearranged immunoglobulin heavy chain of the skin tumor, ocular adnexa tumor, pleural tumor and lymphocytes in the pleural effusion were analyzed using a polymerase chain reaction (PCR)-based assay. This analysis revealed the metachronous MALT lymphoma originated from a distinct B-cell clone. After rituximub and CHOP therapy, complete remission was obtained. Although MALT lymphoma occurs in a wide variety of body sites, the pleural presentation of MALT lymphoma is very rare. Lifelong observation of all patients treated for MALT lymphoma is required because of the high frequency of dissemination and recurrence.