Pulmonary arterial hypertension (PAH) is a progressive and fatal disease driven by vascular remodelling and inflammation. Presenting symptoms of PAH are nonspecific, making diagnosis often late when the disease is irreversible. Endothelial damage occurs early in the disease progress and medial thickening due to proliferating smooth muscle cells in the distal arteries is the earliest known pathology. Circulating microparticles (MPs) are vesicles released by various cells and used as markers of cell activation during inflammation and vascular damage in various vasculopathies. Thus, the aim was to identify circulating MPs, with a special interest to smooth muscle MPs, to be used as biomarkers in PAH. Initially, I characterised smooth muscle MPs derived from growing smooth muscle cells in culture. Smooth muscle MPs were positive for platelet derived growth factor receptor- β (PDGFR-β ), endoglin, intracellular cell adhesion molecule (ICAM-1) and neural glial antigen 2 (NG2) but negative for platelet endtholial cell adhesion molecule-1 (PECAM-1). High levels of endoglin+/ICAM-1+ and low levels of PDGFRβ +/NG2+ MPs were derived from human umbilical cord vein endothelial cells. PDGF, tumour necrosis factor-α, transforming growth factor β, and endothelin-1 were growth factors and cytokines that could stimulate the release of MPs from growing smooth muscle cells. Having characterised smooth muscle MPs (SMMPs), I investigated their levels in plasma from pulmonary arterial hypertension patients and compared them with other vascular inflammatory diseases. Circulating levels of total, smooth muscle, endothelial, leukocyte, and platelet MPs were elevated in PAH patients compared to age-matched healthy controls and in patients with myocardial ischemia and HIV. PAH drugs, particularly prostacyclin mimetics were effective in decreasing MP numbers in cell culture and in patients after long-term therapy. The function of MPs and mechanism of their release inhibition by the prostacyclin analogue treprostinil was investigated. MPs in plasma and cultured smooth muscle cells were procoagulant, as measured using a thrombin generation assay, and induced smooth muscle proliferation. Treprostinil inhibited SMMP release via the prostacyclin receptor and the prostaglandin E2 receptor, and also inhibited cell proliferation. Furthermore, the mimetic inhibited calcineurin/nuclear factor of activated T-cells (NFAT) signalling, which was partially reversed by blockade of peroxisome proliferator activated receptor. As calcineurin/NFAT is a driver of smooth muscle proliferation and remodelling, it may be a novel target through which prostacyclin may be signalling.
Background: We aim to investigate whether circulating microparticle (CMPs) subsets were raised amongst people presenting with a new diagnosis of HIV and advanced immune suppression in Malawi, and whether they associated with arterial stiffness.Methods: Microparticle characterisation and carotid femoral Pulse Wave Velocity (cfPWV) were carried out in a cohort of adults with a new HIV diagnosis and CD4 <100 cells/µL at 2 weeks post ART initiation. HIV uninfected controls were matched on age, systolic BP and diastolic BP in a 1:1 ratio. Circulating microparticles were identified from platelet poor plasma and stained for endothelial, leucocyte, monocyte and platelet markers.Results: The median (IQ) total CMP count for 71 participants was 1 log higher in HIV compared to those without (p<0.0001) and was associated with arterial stiffness (spearman rho 0.47, p<0.001). In adjusted analysis, every log increase in circulating particles showed a 20% increase in cfPWV (95% CI 4 – 40%, p=0.02). In terms of subsets, endothelial and platelet derived microparticles were most strongly associated with HIV. Endothelial derived E-selectin+ CMPs were 1.3log-fold higher and platelet derived CD42a+ CMPs were 1.4log-fold higher (both p<0.0001). Endothelial and platelet derived CMPs also correlated most closely with arterial stiffness [spearman rho: E-selectin+ 0.57 and CD42a 0.56, both p<0.0001).Conclusions: Circulating microparticles associate strongly with arterial stiffness among PLWH in Malawi. Endothelial and platelet microparticles are the predominant cell origin types, indicating that platelet driven endothelial dysfunction pathways warrant further investigation in HIV associated arterial stiffness.
Cardiovascular diseases, particularly coronary artery disease (CAD), remain the leading cause of death worldwide in recent years, with myocardial infarction (MI) being the most common form of CAD. Atherosclerosis has been highlighted as one of the drivers of CAD, and much research has been carried out to understand and treat this disease. However, there remains much to be better understood and developed in treating this disease. Genome editing technologies have been widely used to establish models of disease as well as to treat various genetic disorders at their root. In this review, we aim to highlight the various ways genome editing technologies can be applied to establish models of atherosclerosis, as well as their therapeutic roles in both atherosclerosis and the clinical implications of CAD.
Introduction: Pulmonary arterial hypertension (PAH) is a progressive and fatal disease. Inflammation is thought to be a key player in PAH and stimulates the release of submicron vesicles known as microparticles (MPs) from various cells including endothelial cells. These MPs have shown to be elevated in pulmonary hypertension and correlate with disease severity. A hallmark of PAH is medial thickening but it is unclear whether MPs might be released from vascular smooth muscle cells into the circulation from PAH patients after endothelial damage. Aim: We investigated whether MPs could be detected and characterised after an inflammatory insult on pulmonary arterial smooth muscle cells (PASMCs) isolated from PAH patients. Methods: Serum with or without the mitogen PDGF-BB was used to stimulate PASMCs and Platelet derived growth factor receptor β (PDGFRβ), endoglin, ICAM1, MCAM, VCAM1, KDR, α smooth muscle actin, sm22α, and annexin V MPs were measured by flow cytometry. Results: Levels of annexin V+ total MPs were significantly increased after PDGF-BB stimulation after 24 hours compared to serum control (p
Introduction: Chronic obstructive pulmonary disease (COPD) remains a major public health problem. Many patients suffering from chronic obstructive lungs diseases are of poor economic status, mostly illiterate, therefore has a direct bearing on patient compliance. Tiotropium is a new anticholinergic therapy for chronic obstructive pulmonary disease that differs from ipratropium by its functional relative selectively for musarinic receptor subtypes and which allows single dosing a day. This study presents a cost-effectiveness, efficacy, and side-effects of Ipratropium bromide and Tiotropium in COPD. Methods: Prospective study was conducted In Kathmandu University Teaching Hospital, between the year 2008 and 2009 in terms of cost-effectiveness, efficacy, and side-effects of Tiotropium and Ipratropium amongst COPD patients. Results: Tiotropium and Ipratropium were prescribed in total of 57 patients (30 in ipratropium bromide and 27 in tiotropium bromide) for the management of COPD among outpatients. There were no significant differences in age, height, weight and baseline lung function parameters (FEV1 and PEF) between the two drugs i.e. ipratropium bromide and tiotropium bromide. Significant improvement in lung function parameters were found in each respective group of drugs after bronchodilator therapy. Tiotropium results in significant reduction of Chronic Obstructive Pulmonary disease exacerbations and significant improvement in quality of life, lung function, and dyspnoea compared to ipratropium. The additional cost to achieve these favorable outcomes was cheaper than Ipratropium bromide. (Nepalese Rs. 7.03 per day for tiotropium as compared to Rs. 9.06 for Ipratropium) Conclusions: Tiotropium results in significant reduction of chronic obstructive pulmonary disease exacerbations and significant improvement in quality of life, lung function and dyspnoea compared to Ipratropium.
Abstract Background While most thyroid nodules are benign, 7–15% are malignant. Patients with indeterminate thyroid nodules (specifically Bethesda IV/Thy3f) often undergo diagnostic hemithyroidectomy to reach a diagnosis on final histology. The aim of this study was to assess the feasibility of circulating large extracellular vesicles as diagnostic biomarkers in patients presenting with Thy3f thyroid nodules. Methods This was a two-gate diagnostic accuracy study; patients with Thy3f thyroid nodules were age, sex and body mass index matched to healthy individuals. Final histology confirmed benign and malignant diagnoses. Plasma large extracellular vesicle counts were quantified using flow cytometry. Large extracellular vesicle microRNA and protein profiles were identified using next generation sequencing and mass spectrometry, respectively. Results A total of 42 patients with Thy3f nodules (22 with cancer, 20 with non-cancer diagnosis) and 16 healthy controls were included. Total large extracellular vesicle concentrations and the concentrations of extracellular vesicles expressing epithelial cell adhesion molecule and the cancer markers atypical chemokine receptor type 7, extracellular matrix metalloproteinase inducer and syndecan-4 were significantly higher in patients with Thy3f nodules (cancer and non-cancer) compared with healthy individuals. In patients with cancerous versus non-cancer Thy3f nodules, one microRNA was upregulated: mir-195–3p (P < 0.001). Five were downregulated: mir-3176 (P < 0.001), mir-205-5p (P < 0.001), novel-hsa-mir-208-3p (P < 0.001), mir-3529-3p (P = 0.01) and let-7i-3p (P = 0.02). Furthermore, three large extracellular vesicle proteins (kallikrein-related peptidase11 (KLK11) (P = 0.001), alpha-1-acid glycoprotein 2 (A1AG2) (P <0.001) and small integral membrane protein 1 (SMIM1) (P = 0.04)) were significantly upregulated, while 20 large extracellular vesicle proteins were significantly downregulated (most downregulated: chemokine (C-X-C motif) ligand 7 (CXCL7), tubulin beta chain 1 (TBB1), binding immunoglobulin protein (BIP) and actinin alpha 1 (ACTN1) (P < 0.001)) in cancerous compared with non-cancer Thy3f nodules. Conclusion Circulating large extracellular vesicle miRNA and protein profiles have a high diagnostic value to discriminate between benign and malignant nodules for patients with Thy3f cytology. Further validation for clinical performance will be needed.
Background: We aimed to investigate whether circulating microparticle (CMPs) subsets were raised amongst people presenting with human immunodeficiency virus (HIV) and advanced immune suppression in Malawi, and whether they associated with arterial stiffness.Methods: Antiretroviral therapy (ART)-naïve adults with a new HIV diagnosis and CD4 <100 cells/µL had microparticle characterisation and carotid femoral Pulse Wave Velocity (cfPWV) at 2 weeks post ART initiation. HIV uninfected controls were matched on age, systolic blood pressure (BP) and diastolic BP in a 1:1 ratio. Circulating microparticles were identified from platelet poor plasma and stained for endothelial, leucocyte, monocyte and platelet markers.Results: The median (IQ) total CMP count for 71 participants was 1 log higher in HIV compared to those without (p<0.0001) and was associated with arterial stiffness (spearman rho 0.47, p<0.001). In adjusted analysis, every log increase in circulating particles showed a 20% increase in cfPWV (95% confidence interval [CI] 4 – 40%, p=0.02). In terms of subsets, endothelial and platelet derived microparticles were most strongly associated with HIV. Endothelial derived E-selectin+ CMPs were 1.3log-fold higher and platelet derived CD42a+ CMPs were 1.4log-fold higher (both p<0.0001). Endothelial and platelet derived CMPs also correlated most closely with arterial stiffness (spearman rho: E-selectin+ 0.57 and CD42a 0.56, both p<0.0001).Conclusions: Circulating microparticles associate strongly with arterial stiffness among people living with HIV in Malawi. Endothelial damage and platelet microparticles are the predominant cell origin types and future translational studies could consider prioritising these pathways.
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