Project description:Pulmonary hypertension (PH) is a rare, progressive pulmonary vasculopathy characterized by increased mean pulmonary arterial pressure, pulmonary vascular remodelling and right ventricular failure. Current treatments are not curative, and new therapeutic strategies are urgently required. Clinical and preclinical evidence has established that inflammation plays a key role in PH pathogenesis, and recently, inflammasomes have been suggested to be central to this process. Inflammasomes are important regulators of inflammation, releasing the pro-inflammatory cytokines IL-1β and IL-18 in response to exogenous pathogen- and endogenous damage-associated molecular patterns. These cytokines are elevated in PH patients, but whether this is a consequence of inflammasome activation remains to be determined. This review will briefly summarize current PH therapies and their pitfalls, introduce inflammasomes and the mechanisms by which they promote inflammation and, finally, highlight the preclinical and clinical evidence for the potential involvement of inflammasomes in PH pathobiology and how they may be targeted therapeutically. LINKED ARTICLES: This article is part of a themed section on Immune Targets in Hypertension. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.12/issuetoc.
Project description:Pulmonary vascular remodeling is the most important pathological characteristic of pulmonary arterial hypertension (PAH). No effective treatment for PAH is currently available because the mechanism underlying vascular remodeling is not completely clear. CD248, also known as endosialin, is a transmembrane protein that is highly expressed in pericytes and fibroblasts. Here, we evaluated the role of CD248 in pulmonary vascular remodeling and the processes of PAH pathogenesis. Activation of CD248 in pulmonary artery smooth muscle cells (PASMCs) was found to be proportional to the severity of PAH. CD248 contributed to platelet-derived growth factor-BB (PDGF-BB)-induced PASMC proliferation and migration along with the shift to more synthetic phenotypes. In contrast, treatment with Cd248 siRNA or the anti-CD248 therapeutic antibody (ontuxizumab) significantly inhibited the PDGF signaling pathway, obstructed NF-κB p65-mediated transcription of Nox4, and decreased reactive oxygen species production induced by PDGF-BB in PAMSCs. In addition, knockdown of CD248 alleviated pulmonary vascular remodeling in rat PAH models. This study provides novel insights into the dysfunction of PASMCs leading to pulmonary vascular remodeling, and provides evidence for anti-remodeling treatment for PAH via the immediate targeting of CD248.
Project description:Current therapies for pulmonary arterial hypertension (PAH) provide symptomatic relief and improve prognosis but fall short of improving long-term survival. There is emerging evidence for a role of inflammatory mediators, primarily IL-6, in the pathogenesis of PAH. However, the mechanisms by which IL-6 potentially affects PAH are unknown. In this issue of the JCI, Tamura, Phan, and colleagues identified ectopic upregulation of the membrane-bound IL-6 receptor (IL6R), indicating classical IL-6 signaling in the smooth muscle layer of remodeled vessels in human and experimental PAH. They performed a series of in vitro and in vivo experiments that provide deeper insights into the mechanisms of classical IL-6 signaling and propose interventions directed against IL6R as a potential therapeutic strategy for PAH.
Project description:Pulmonary arterial hypertension (PAH) is an intractable vascular disease characterized by a progressive increase in pulmonary vascular resistance caused by pulmonary vascular remodeling, which ultimately leads to right-sided heart failure. PAH remains incurable, despite the development of PAH-targeted therapeutics centered on pulmonary artery relaxants. It is necessary to identify the target molecules that contribute to pulmonary artery remodeling. Transient receptor potential (TRP) channels have been suggested to modulate pulmonary artery remodeling. Our study focused on the transient receptor potential ion channel subfamily M, member 7, or the TRPM7 channel, which modulates endothelial-to-mesenchymal transition and smooth muscle proliferation in the pulmonary artery. In this review, we summarize the role and expression profile of TRPM7 channels in PAH progression and discuss TRPM7 channels as possible therapeutic targets. In addition, we discuss the therapeutic effect of a Chinese herbal medicine, Ophiocordyceps sinensis (OCS), on PAH progression, which partly involves TRPM7 inhibition.
Project description:The autonomic nervous system (ANS) and renin-angiotensin-aldosterone system (RAAS) are involved in many cardiovascular disorders, including pulmonary hypertension (PH). The current review focuses on the role of the ANS and RAAS activation in PH and updated evidence of potential therapies targeting both systems in this condition, particularly in Groups 1 and 2. State of the art knowledge in preclinical and clinical use of pharmacologic drugs (beta-blockers, beta-three adrenoceptor agonists, or renin-angiotensin-aldosterone signaling drugs) and invasive procedures, such as pulmonary artery denervation, is provided.
Project description:Nitric oxide (NO) activates soluble guanylate cyclase (sGC) by binding its prosthetic heme group, thereby catalyzing cyclic guanosine monophosphate (cGMP) synthesis. cGMP causes vasodilation and may inhibit smooth muscle cell proliferation and platelet aggregation. The NO-sGC-cGMP pathway is disordered in pulmonary arterial hypertension (PAH), a syndrome in which pulmonary vascular obstruction, inflammation, thrombosis, and constriction ultimately lead to death from right heart failure. Expression of sGC is increased in PAH but its function is reduced by decreased NO bioavailability, sGC oxidation and the related loss of sGC's heme group. Two classes of sGC modulators offer promise in PAH. sGC stimulators (e.g., riociguat) require heme-containing sGC to catalyze cGMP production, whereas sGC activators (e.g., cinaciguat) activate heme-free sGC. Riociguat is approved for PAH and yields functional and hemodynamic benefits similar to other therapies. Its main serious adverse effect is dose-dependent hypotension. Riociguat is also approved for inoperable chronic thromboembolic pulmonary hypertension.
Project description:Pulmonary arterial hypertension (PAH) is a vascular remodeling disease characterized by enhanced pulmonary artery smooth muscle cell (PASMC) proliferation and suppressed apoptosis. Downregulation of the BMPR2 gene along with activation of the transcription factor NFAT have been implicated in the maintenance of pro-proliferative and anti-apoptotic stages of cells. Since an increasing number of microRNAs have been implicated in the regulation of genes specifically important for cell proliferation and apoptosis, we hypothesized that microRNAs might be associated with these cellular features in the etiology of PAH. We demonstrate that downregulation of one such microRNA (miR-204) in human PAH-PASMC promotes the activation of an Src/STAT3/NFAT axis that increases PAH-PASMC proliferation and their resistance to apoptosis. Stimulation experiments using the pro-PAH factors (PDGF, endothelin-1 and angiotensin II) and time course analysis in experimental PAH show that STAT3 activation leads to miR-204 downregulation, thereby activating an Src-dependent positive feedback loop sustaining STAT3 and activating NFAT. More importantly, restoring miR-204 expression decreases proliferation and resistance to apoptosis in human and in an experimental PAH model. Taken together, our study uncovers a new STAT3-miR-204-Src/STAT3/NFAT axis that links the STAT3-dependent downregulation of BMPR2 with the NFAT-mediated pro-proliferative and anti-apoptotic phenotype observed in PAH. Our data point toward a novel potential strategy for treating patients with PAH. Comparative expression profiling of PAH versus healthy patients to evaluate the modulated genes in the disease. Following the demonstration of the downregulation of miR-204 in PAH we want to investigate the effect of the inhibition (using antagomir) of miR-204 expression in PASMC cells.
Project description:Pulmonary arterial hypertension (PAH) is a vascular remodeling disease characterized by enhanced pulmonary artery smooth muscle cell (PASMC) proliferation and suppressed apoptosis. Downregulation of the BMPR2 gene along with activation of the transcription factor NFAT have been implicated in the maintenance of pro-proliferative and anti-apoptotic stages of cells. Since an increasing number of microRNAs have been implicated in the regulation of genes specifically important for cell proliferation and apoptosis, we hypothesized that microRNAs might be associated with these cellular features in the etiology of PAH. We demonstrate that downregulation of one such microRNA (miR-204) in human PAH-PASMC promotes the activation of an Src/STAT3/NFAT axis that increases PAH-PASMC proliferation and their resistance to apoptosis. Stimulation experiments using the pro-PAH factors (PDGF, endothelin-1 and angiotensin II) and time course analysis in experimental PAH show that STAT3 activation leads to miR-204 downregulation, thereby activating an Src-dependent positive feedback loop sustaining STAT3 and activating NFAT. More importantly, restoring miR-204 expression decreases proliferation and resistance to apoptosis in human and in an experimental PAH model. Taken together, our study uncovers a new STAT3-miR-204-Src/STAT3/NFAT axis that links the STAT3-dependent downregulation of BMPR2 with the NFAT-mediated pro-proliferative and anti-apoptotic phenotype observed in PAH. Our data point toward a novel potential strategy for treating patients with PAH. Comparative expression profiling of PAH versus healthy patients to evaluate the modulated genes in the disease. Following the demonstration of the downregulation of miR-204 in PAH we want to investigate the effect of the inhibition (using antagomir) of miR-204 expression in PASMC cells.