Derived myeloid lineage induced pluripotent stem as a platform to study human C-C chemokine receptor type 5Δ32 homozygotes.

The C-C chemokine receptor type 5 (CCR5) expressed on immune cells supports inflammatory responses by directing cells to the inflammation site. CCR5 is also a major coreceptor for macrophage tropic human immunodeficiency viruses (R5-HIV-1) and its variants can confer protection from HIV infection, making it an ideal candidate to target for therapy. We developed a stepwise protocol that differentiates induced pluripotent stem cells (iPSCs) from individuals homozygous for the CCR5Δ32 variant and healthy volunteers into myeloid lineage induced monocytes (iMono) and macrophages (iMac).

Reduced FOXF1 links unrepaired DNA damage to pulmonary arterial hypertension.

Pulmonary arterial hypertension (PAH) is a progressive disease in which pulmonary arterial (PA) endothelial cell (EC) dysfunction is associated with unrepaired DNA damage. BMPR2 is the most common genetic cause of PAH. We report that human PAEC with reduced BMPR2 have persistent DNA damage in room air after hypoxia (reoxygenation), as do mice with EC-specific deletion of Bmpr2 (EC-Bmpr2) and persistent pulmonary hypertension.

Mast cell activation and degranulation in acute artery injury: A target for post-operative therapy.

The increasing incidence of cardiovascular disease (CVD) has led to a significant ongoing need to address this surgically through coronary artery bypass grafting (CABG) and percutaneous coronary interventions (PCI). From this, there continues to be a substantial burden of mortality and morbidity due to complications arising from endothelial damage, resulting in restenosis. Whilst mast cells (MC) have been shown to have a causative role in atherosclerosis and other vascular diseases, including restenosis due to vein engraftment; here, we demonstrate their rapid response to arterial wire injury, recapitulating the endothelial damage seen in PCI procedures.

Constitutively active Lyn kinase causes a cutaneous small vessel vasculitis and liver fibrosis syndrome.

Neutrophilic inflammation is a hallmark of many monogenic autoinflammatory diseases; pathomechanisms that regulate extravasation of damaging immune cells into surrounding tissues are poorly understood. Here we identified three unrelated boys with perinatal-onset of neutrophilic cutaneous small vessel vasculitis and systemic inflammation. Two patients developed liver fibrosis in their first year of life.

Dysregulated Smooth Muscle Cell BMPR2-ARRB2 Axis Causes Pulmonary Hypertension.

Objective: Mutations in (bone morphogenetic protein receptor 2) are associated with familial and sporadic pulmonary arterial hypertension (PAH). The functional and molecular link between loss of BMPR2 in pulmonary artery smooth muscle cells (PASMC) and PAH pathogenesis warrants further investigation, as most investigations focus on BMPR2 in pulmonary artery endothelial cells. Our goal was to determine whether and how decreased BMPR2 is related to the abnormal phenotype of PASMC in PAH.

Development of vascular disease models to explore disease causation and pathomechanisms of rare vascular diseases.

As the field of medicine is striving forward heralded by a new era of next-generation sequencing (NGS) and integrated technologies such as bioprinting and biological material development, the utility of rare monogenetic vascular disease modeling in this landscape is starting to emerge. With their genetic simplicity and broader applicability, these patient-specific models are at the forefront of modern personalized medicine. As a collective, rare diseases are a significant burden on global healthcare systems, and rare vascular diseases make up a significant proportion of this.

Role of endothelial cells in pulmonary fibrosis via SREBP2 activation.

Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease with limited treatment options. Despite endothelial cells (ECs) comprising 30% of the lung cellular composition, the role of EC dysfunction in pulmonary fibrosis (PF) remains unclear. We hypothesize that sterol regulatory element-binding protein 2 (SREBP2) plays a critical role in the pathogenesis of PF via EC phenotypic modifications.

Monocyte-released HERV-K dUTPase engages TLR4 and MCAM causing endothelial mesenchymal transition.

We previously reported heightened expression of the human endogenous retroviral protein HERV-K deoxyuridine triphosphate nucleotidohydrolase (dUTPase) in circulating monocytes and pulmonary arterial (PA) adventitial macrophages of patients with PA hypertension (PAH). Furthermore, recombinant HERV-K dUTPase increased IL-6 in PA endothelial cells (PAECs) and caused pulmonary hypertension in rats. Here we show that monocytes overexpressing HERV-K dUTPase, as opposed to GFP, can release HERV-K dUTPase in extracellular vesicles (EVs) that cause pulmonary hypertension in mice in association with endothelial mesenchymal transition (EndMT) related to induction of SNAIL/SLUG and proinflammatory molecules IL-6 as well as VCAM1.

iPSC-endothelial cell phenotypic drug screening and in silico analyses identify tyrphostin-AG1296 for pulmonary arterial hypertension.

Pulmonary arterial hypertension (PAH) is a progressive disorder leading to occlusive vascular remodeling. Current PAH therapies improve quality of life but do not reverse structural abnormalities in the pulmonary vasculature. Here, we used high-throughput drug screening combined with in silico analyses of existing transcriptomic datasets to identify a promising lead compound to reverse PAH.

PPARγ-p53-Mediated Vasculoregenerative Program to Reverse Pulmonary Hypertension.

Rationale: In pulmonary arterial hypertension (PAH), endothelial dysfunction and obliterative vascular disease are associated with DNA damage and impaired signaling of BMPR2 (bone morphogenetic protein type 2 receptor) via two downstream transcription factors, PPARγ (peroxisome proliferator-activated receptor gamma), and p53.

Objective: We investigated the vasculoprotective and regenerative potential of a newly identified PPARγ-p53 transcription factor complex in the pulmonary endothelium.

Methods And Results: In this study, we identified a pharmacologically inducible vasculoprotective mechanism in pulmonary arterial and lung MV (microvascular) endothelial cells in response to DNA damage and oxidant stress regulated in part by a BMPR2 dependent transcription factor complex between PPARγ and p53.

BMPR2-expressing bone marrow-derived endothelial-like progenitor cells alleviate pulmonary arterial hypertension in vivo.

Background And Objective: Pulmonary arterial hypertension (PAH) is characterized by increased resistance in the distal pulmonary arteries, ultimately leading to right heart failure and, despite the available therapeutics, survival remains poor. Reduced expression of bone morphogenetic protein receptor type 2 (BMPR2) is strongly associated with PAH. Cell therapies are of interest in PAH, but whether this approach can upregulate BMPR2 is not known.

BMPR2 gene therapy for PAH acts via Smad and non-Smad signalling.

Background And Objective: Pulmonary arterial hypertension (PAH) continues to be a fatal disease and is associated with downregulation of bone morphogenetic protein receptor type-2 (BMPR2). Our approach is to upregulate BMPR2 in the pulmonary vasculature allowing us to examine the changes in endothelial cell signalling and better understand what pathways are altered when disease is attenuated using this treatment approach.

Methods: We used gene delivery of BMPR2 to human pulmonary endothelial cells to investigate downstream signalling, then assessed the impact of this approach on downstream signalling in vivo in rats with PAH using the monocrotaline (MCT) model.

BMPR2 gene delivery reduces mutation-related PAH and counteracts TGF-β-mediated pulmonary cell signalling.

Background And Objective: Idiopathic, familial and secondary pulmonary arterial hypertension (PAH) are associated with reduced bone morphogenetic protein receptor type 2 (BMPR2) expression, and in some contexts, TGF-β upregulation. Our aims were to assess BMPR2 gene therapy in a PAH mouse model and to assess the impact on TGF-β signalling.

Methods: Using a targeted in vivo gene delivery approach, we assessed the impact of BMPR2 gene delivery in a transgenic mouse model in which PAH was first induced by doxycycline driven expression of a dominant negative BMPR2 mutant (R899X).