Decreased haptoglobin levels inversely correlated with pulmonary artery pressure in patients with pulmonary arterial hypertension: A cross-sectional study

Quantitative Proteomic and Phosphoproteomic Profiling of Lung Tissues from Pulmonary Arterial Hypertension Rat Model

Pulmonary arterial hypertension (PAH) is a rare but fatal disease characterized by elevated pulmonary vascular resistance and increased pressure in the distal pulmonary arteries. Systematic analysis of the proteins and pathways involved in the progression of PAH is crucial for understanding the underlying molecular mechanism. In this study, we performed tandem mass tags (TMT)-based relative quantitative proteomic profiling of lung tissues from rats treated with monocrotaline (MCT) for 1, 2, 3 and 4 weeks. A total of 6759 proteins were quantified, among which 2660 proteins exhibited significant changes (p-value < 0.05, fold change < 0.83 or >1.2). Notably, these changes included several known PAH-related proteins, such as Retnla (resistin-like alpha) and arginase-1. Furthermore, the expression of potential PAH-related proteins, including Aurora kinase B and Cyclin-A2, was verified via Western blot analysis. In addition, we performed quantitative phosphoproteomic analysis on the lungs from MCT-induced PAH rats and identified 1412 upregulated phosphopeptides and 390 downregulated phosphopeptides. Pathway enrichment analysis revealed significant involvement of pathways such as complement and coagulation cascades and the signaling pathway of vascular smooth muscle contraction. Overall, this comprehensive analysis of proteins and phosphoproteins involved in the development and progression of PAH in lung tissues provides valuable insights for the development of potential diagnostic and treatment targets for PAH.

BASP1 promotes high glucose-induced endothelial apoptosis in diabetes via activation of EGFR signaling

AIMS

Diabetes mellitus is a common chronic disease of glucose metabolism. Endothelial dysfunction is an early event in diabetes complicated by cardiovascular disease. This study aimed to reveal the expression of BASP1 and its biological roles in endothelial cell dysfunction in diabetes complicated by cardiovascular disease.

MATERIALS AND METHODS

By analyzing the databases related to diabetes complicated with coronary heart disease, BASP1 was screened out as an upregulated gene. Human umbilical vein endothelial cells (HUVECs) and primary mouse aortic endothelial cells were treated with high glucose to establish cell models of diabetes-related endothelial dysfunction, and the expression changes of BASP1 were verified by RT-qPCR, western blot, and immunofluorescence. BASP1 was silenced or overexpressed by siRNA or overexpression plasmid, and its effects on cell migration, apoptosis, tube formation, inflammatory response, and ROS were detected. The possible signaling pathway of BASP1 was found and the mechanism of BASP1 on promoting the progression of endothelial dysfunction was explored using the EGFR inhibitor, gefitinib.

RESULTS

Bioinformatics analysis indicated that the expression of BASP1 in patients with diabetes mellitus and concomitant coronary heart disease was increased. High glucose induced the upregulation of BASP1 expression in endothelial cells, and showed a time-dependent relationship. Silencing of BASP1 alleviated the damage of high glucose to endothelial cells. BASP1 regulated EGFR positively. The promoting effect of BASP1 on endothelial cell apoptosis may be achieved by regulating the EGFR pathway.

CONCLUSION

BASP1 promotes endothelial cell injury induced by high glucose in patients with diabetes, which may be activated by activating the EGFR pathway.

Serum biomarker analysis at the protein level on pulmonary hypertension secondary to old anterior myocardial infarction

Pulmonary hypertension (PH) related to old anterior myocardial infarction (OAMI) always accompanies a bad prognosis, and thus, we aimed to screen serum biomarkers related to PH in OAMI patients. According to right ventricular systolic pressure, we divided mice into sham, OAMI, and PH-OAMI groups and evaluated body, heart and lung weight, heart function, pulmonary blood flow velocity, cardiac fibrotic area, and pulmonary arteriole condition. Lung and serum were under the proteomic analysis. Levels of three identified proteins were measured. Compared with sham and OAMI mice, PH-OAMI mice showed heart dysfunction, low pulmonary blood flow, high right ventricular systolic pressure, heavy heart and lung weight, large cardiac fibrotic area, and pathological pulmonary arteriole remodeling (P<0.05 or P<0.01). Haptoglobin, annexin A5, and Ig mu chain C region of lung and serum were changed significantly in PH-OAMI mice (P<0.01). Then, we collected serum and clinical data, measured three serum protein levels, and performed multivariate regression and receiver operating characteristic curve in patients (normal, OAMI, and PH-OAMI groups). Compared with normal and OAMI patients, serum levels of three proteins in PH-OAMI patients were also altered notably (P<0.01). These three proteins can predict PH in OAMI patients (P<0.01). Receiver operating characteristic curve analysis revealed haptoglobin (cut-off value: 78.295, sensitivity: 62.8%, specificity: 94.4%), annexin A5 (cut-off value: 151.925, sensitivity: 41.9%, specificity: 82.4%), and Ig mu chain C region (cut-off value: 168.885, sensitivity: 86.0%, specificity: 79.6%) (P<0.01). Three circulating serum proteins can be useful for the categorization of OAMI patients with and without PH.

Concurrent onset of acute lupus myocarditis, pulmonary arterial hypertension and digital gangrene in a lupus patient: a possible role of vasculitis to the rare disorders

Acute lupus myocarditis and pulmonary arterial hypertension (PAH) are rare complications associated with systemic lupus erythematosus (SLE). No previous reports have shown the coexistence of these disorders. Here we present a 41-year-old patient with SLE who concurrently developed severe acute lupus myocarditis and PAH with digital gangrene as an initial manifestation. Acute lupus myocarditis and PAH were successfully treated with prednisolone and intravenous cyclophosphamide pulse therapy (600-700 mg × 6) along with anticoagulant therapy. Catheter-directed thrombolysis was required for digital gangrene caused by vasculitis. Concurrent development of these rare disorders may represent a common mechanism such vasculitis as an underlining cause of SLE.

The Hepcidin/Ferroportin axis modulates proliferation of pulmonary artery smooth muscle cells

Studies were undertaken to examine any role for the hepcidin/ferroportin axis in proliferative responses of human pulmonary artery smooth muscle cells (hPASMCs). Entirely novel findings have demonstrated the presence of ferroportin in hPASMCs. Hepcidin treatment caused increased proliferation of these cells most likely by binding ferroportin resulting in internalisation and cellular iron retention. Cellular iron content increased with hepcidin treatment. Stabilisation of ferroportin expression and activity via intervention with the therapeutic monoclonal antibody LY2928057 reversed proliferation and cellular iron accumulation. Additionally, IL-6 treatment was found to enhance proliferation and iron accumulation in hPASMCs; intervention with LY2928057 prevented this response. IL-6 was also found to increase hepcidin transcription and release from hPASMCs suggesting a potential autocrine response. Hepcidin or IL-6 mediated iron accumulation contributes to proliferation in hPASMCs; ferroportin mediated cellular iron excretion limits proliferation. Haemoglobin also caused proliferation of hPASMCs; in other novel findings, CD163, the haemoglobin/haptoglobin receptor, was found on these cells and offers a means for cellular uptake of iron via haemoglobin. Il-6 was also found to modulate CD163 on these cells. These data contribute to a better understanding of how disrupted iron homeostasis may induce vascular remodelling, such as in pulmonary arterial hypertension.

Reduced expression of microRNA-199a-3p is associated with vascular endothelial cell injury induced by type 2 diabetes mellitus

The aim of the present study was to investigate the function and mechanism of action of microRNA (miRNA or miR)-199a-3p in vascular endothelial cell injury induced by type 2 diabetes mellitus (T2DM). A total of 36 patients with T2DM (26 males and 10 females; mean age, 52.5±7.0 years) and 20 healthy subjects (10 males and 10 females; mean age, 55.6±4.5 years) were included in the present study. Peripheral blood samples were obtained from all participants and total RNA was extracted Reverse transcription-quantitative polymerase chain reaction was performed to determine the expression of miR-199a-3p. Following the transfection of human umbilical vein endothelial cells (HUVECs) with a negative control (NC) miRNA or miR-199a-3p mimics, cell proliferation was assessed using a Cell Counting kit-8 assay. Cell migration was investigated using Transwell assays and flow cytometry was performed to detect the apoptosis of HUVECs. HUVECs were infected with Ad-GFP-LC3B and laser-scanning confocal microscopy was performed to observe autophagosomes in HUVECs. Western blotting was used to measure the expression of proteins associated with autophagy and the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/nuclear factor (NF)-κB signaling pathway. MiR-199a-3p was downregulated in peripheral blood from patients with T2DM compared with healthy subjects. Transfection with miR-199a-3p mimics promoted the proliferation and migration of HUVECs. However, miR-199a-3p overexpression inhibited the apoptosis of HUVECs. MiR-199a-3p facilitated HUVEC autophagy by affecting autophagy-associated signaling pathways. Furthermore, miR-199a-3p regulated the biological functions of HUVECs via the PI3K/AKT/NF-κB signaling pathway. The results of the present study suggest that miR-199a-3p expression was reduced in patients with T2DM compared with healthy subjects and may be associated with vascular endothelial cell injury. In addition, miR-199a-3p promoted the proliferation, migration and autophagy of HUVECs, potentially by regulating the PI3K/AKT/NF-κB signaling pathway. Therefore, miR-199a-3p may function as protector of vascular endothelia.

Pulmonary Arterial Hypertension: Iron Matters

The interplay between iron and oxygen is longstanding and central to all aerobic life. Tight regulation of these interactions including homeostatic regulation of iron utilization ensures safe usage of this limited resource. However, when control is lost adverse events can ensue, which are known to contribute to an array of disease processes. Recently, associations between disrupted iron homeostasis and pulmonary artery hypertension (PAH) have been described with the suggestion that there is a contributory link with disease. This review provides a background for iron regulation in humans, describes PAH classifications, and discusses emerging literature, which suggests a role for disrupted iron homeostatic control in various sub-types of PAH, including a role for decompartmentalization of hemoglobin. Finally, the potential for therapeutic options to restore iron homeostatic balance in PAH are discussed.

The clinical characteristics and long-term prognosis of pulmonary arterial hypertension associated with hereditary hemorrhagic telangiectasia

Pulmonary arterial hypertension (PAH) is a severe complication of hereditary hemorrhagic telangiectasia (HHT); however, little is known about its clinical characteristics and prognosis. Nine newly diagnosed HHT-PAH patients were prospectively recruited between October 2007 and January 2016 and were followed up every half-year. Eighteen idiopathic pulmonary arterial hypertension (IPAH) patients, matched with HHT-PAH patients on mean pulmonary arterial pressure, pulmonary capillary wedge pressure, pulmonary vascular resistance, cardiac index, and World Health Organization (WHO) functional class (FC), were recruited. The clinical characteristics of HHT-PAH patients were described and the prognosis of these two cohorts were compared. Of HHT-PAH patients, 55.56% were WHO FC III. Kaplan–Meier survival analysis showed one- and three-year survival rates of HHT-PAH patients were 77.8% and 53.3% respectively, which were worse than matched IPAH patients (log rank: P = 0.047). HHT-PAH patients had higher red cell distribution width (14.88 ± 2.93% versus 13.19 ± 0.83%, P = 0.031), larger right ventricular anteroposterior diameter (34.67 ± 6.67 mm versus 28.56 ± 6.35 mm, P = 0.029), and lower mean corpuscular hemoglobin concentration (317.38 ± 17.71 g/L versus 335.72 ± 14.68 g/L, P = 0.011) than matched IPAH patients. Multivariate Cox proportional hazards regression analyses showed baseline total bilirubin independently predicted the mortality of HHT-PAH after adjusting by age, cardiac index, mixed venous oxygen saturation, or serum uric acid. HHT-PAH patients may have a worse prognosis than matched IPAH patients. Baseline total bilirubin may be a promising predictor for the long-term prognosis in HHT-PAH patients.