Hypoxia-induced long non-coding RNA plasmacytoma variant translocation 1 upregulation aggravates pulmonary arterial smooth muscle cell proliferation by regulating autophagy via miR-186/Srf/Ctgf and miR-26b/Ctgf signaling pathways

Isovaleroylbinankadsurin A ameliorates atherosclerosis and restenosis by promoting LXRα signaling pathway and inhibiting TGF-β1 and FHL1 signaling pathways

BACKGROUND

Atherosclerosis is a leading factor in the development of several cardiovascular conditions, including ischemic heart disease, stroke, and peripheral vascular disease. A defining characteristic of atherosclerosis is the formation of macrophages and vascular smooth muscle cells (VSMCs)-derived foam cells in plaques. Angioplasty can effectively remove atherosclerotic plaque, while it may lead to restenosis. A crucial pathological feature of restenosis is neointimal formation, which is driven by the phenotypic change, growth, and migration of VSMCs. Nonetheless, there are only a handful of effective strategies. Kadsura coccinea is a folk Chinese herb mainly used to treat rheumatism, chronic gastritis, bruises, and dysmenorrhea. Isovaleroylbinankadsurin A (ISBA), isolated from Kadsura coccinea roots, is a dibenzocyclooctadiene lignan that has recently been shown to be beneficial for myocardial ischemia-reperfusion injury. However, its protective effects on atherosclerosis and restenosis remain unknown.

PURPOSE

To investigate the effects and related mechanisms of ISBA on atherosclerosis and restenosis.

METHODS

Foam cells were induced by ox-LDL in vitro, and a high-fat diet was administered to ApoE-/- mice. HE staining was applied to evaluate the morphology of vascular tissues. Lipid accumulation of plaques and foam cells was measured using BODIPY-cholesterol, DiI-ox-LDL, Oil Red O staining, and cholesterol quantification tests. A mouse model of femoral artery injury and an in vitro VSMC proliferation model were established. The CCK-8, EdU, plate clone formation, and wound-healing assays were used to evaluate cell viability and migration. Western blot analysis and immunohistochemistry were employed to assess the levels of crucial proteins in ISBA mediating atherosclerosis and restenosis.

RESULTS

We found for the first time that ISBA could significantly alleviate atherosclerosis and restenosis. Mechanistically, ISBA inhibited lipid accumulation and reduced foam cell formation through the activation of LXRα/ABCA1 signaling pathway, which contributed to preventing atherosclerosis. In addition, ISBA could also suppress the phenotypic switch, proliferation, and migration of VSMCs through repressing TGF-β1/ERK1/2/CTGF and FHL1/ERK1/2/CTGF signaling pathways, thereby mitigating neointimal formation and restenosis.

CONCLUSION

This study offers a groundbreaking and expanded exploration of the pharmacological effects of ISBA. ISBA may be a novel therapeutic drug to prevent atherosclerosis and restenosis.

A new perspective on targeting pulmonary arterial hypertension: Programmed cell death pathways (Autophagy, Pyroptosis, Ferroptosis)

Pulmonary arterial hypertension (PAH) is a severe cardiovascular disease characterized by elevated pulmonary vascular resistance, progressive increases in pulmonary artery pressures, ultimately leading to right-sided heart failure, and potentially mortality. Pulmonary vascular remodeling is pivotal in PAH onset and progression. While targeted drug therapies have notably ameliorated PAH prognosis, current medications primarily focus on vascular vasodilation, with limited ability to reverse pulmonary vascular remodeling fundamentally, resulting in suboptimal patient prognoses. Cellular death in pulmonary vasculature, once thought to be confined to apoptosis and necrosis, has evolved with the identification of pyroptosis, autophagy, and ferroptosis, revealing their association with vascular injury in PAH. These novel forms of regulated cellular death impact reactive oxygen species (ROS) generation, calcium stress, and inflammatory cascades, leading to pulmonary vascular cell loss, exacerbating vascular injury, and mediating adverse remodeling, inflammation, immune anomalies, and current emerging mechanisms (such as endothelial-mesenchymal transition, abnormal energy metabolism, and epigenetic regulation) in the pathogenesis of PAH. This review comprehensively delineates the roles of autophagy, pyroptosis, and ferroptosis in PAH, elucidating recent advances in their involvement and regulation of vascular injury. It juxtaposes their distinct functions in PAH and discusses the interplay of these programmed cell deaths in pulmonary vascular injury, highlighting the benefits of combined targeted therapies in mitigating pulmonary arterial hypertension-induced vascular injury, providing novel insights into targeted treatments for pulmonary arterial hypertension.

LncRNA MIR210HG promotes phenotype switching of pulmonary arterial smooth muscle cells through autophagy-dependent ferroptosis pathway

Hypoxic pulmonary hypertension (HPH) is a pathophysiological syndrome in which pulmonary vascular pressure increases under hypoxic stimulation and there is an urgent need to develop emerging therapies for the treatment of HPH. LncRNA MIR210HG is a long non-coding RNA closely related to hypoxia and has been widely reported in a variety of tumor diseases. But its mechanism in hypoxic pulmonary hypertension is not clear. In this study, we identified for the first time the potential effect of MIR210HG on disease progression in HPH. Furthermore, we investigated the underlying mechanism through which elevated levels of MIR210HG promotes the transition from a contractile phenotype to a synthetic phenotype in PASMCs under hypoxia via activation of autophagy-dependent ferroptosis pathway. While overexpression of HIF-2α in PASMCs under hypoxia significantly reversed the phenotypic changes induced by MIR210HG knockdown. We further investigated the potential positive regulatory relationship between STAT3 and the transcription of MIR210HG in PASMCs under hypoxic conditions. In addition, we established both in vivo and in vitro models of HPH to validate the differential expression of specific markers associated with hypoxia. Our findings suggest a potential mechanism of LncRNA MIR210HG in the progression of HPH and offer potential targets for disease intervention and treatment.

Emerging connectivity of programmed cell death pathways and pulmonary vascular remodelling during pulmonary hypertension

Pulmonary hypertension (PH) is a chronic progressive vascular disease characterized by abnormal pulmonary vascular resistance and pulmonary artery pressure. The major structural alteration during PH is pulmonary vascular remodelling, which is mainly caused by the imbalance between proliferation and apoptosis of pulmonary vascular cells. Previously, it was thought that apoptosis was the only type of programmed cell death (PCD). Soon afterward, other types of PCD have been identified, including autophagy, pyroptosis, ferroptosis and necroptosis. In this review, we summarize the role of the above five forms of PCD in mediating pulmonary vascular remodelling, and discuss their guiding significance for PH treatment. The current review could provide a better understanding of the correlation between PCD and pulmonary vascular remodelling, contributing to identify new PCD-associated drug targets for PH.

Epigenetic regulation of programmed cell death in hypoxia-induced pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a severe progressive disease that may cause early right ventricular failure and eventual cardiac failure. The pathogenesis of PAH involves endothelial dysfunction, aberrant proliferation of pulmonary artery smooth muscle cells (PASMCs), and vascular fibrosis. Hypoxia has been shown to induce elevated secretion of vascular endothelial growth factor (VEGF), leading to the development of hypoxic PAH. However, the molecular mechanisms underlying hypoxic PAH remain incompletely understood. Programmed cell death (PCD) is a natural cell death and regulated by certain genes. Emerging evidence suggests that apoptotic resistance contributes to the development of PAH. Moreover, several novel types of PCD, such as autophagy, pyroptosis, and ferroptosis, have been reported to be involved in the development of PAH. Additionally, multiple diverse epigenetic mechanisms including RNA methylation, DNA methylation, histone modification, and the non-coding RNA molecule-mediated processes have been strongly linked to the development of PAH. These epigenetic modifications affect the expression of genes, which produce important changes in cellular biological processes, including PCD. Consequently, a better understanding of the PCD processes and epigenetic modification involved in PAH will provide novel, specific therapeutic strategies for diagnosis and treatment. In this review, we aim to discuss recent advances in epigenetic mechanisms and elucidate the role of epigenetic modifications in regulating PCD in hypoxia-induced PAH.

Molecular regulation and therapeutic implications of cell death in pulmonary hypertension

Pulmonary hypertension (PH) is a clinical and pathophysiological syndrome caused by changes in pulmonary vascular structure or function that results in increased pulmonary vascular resistance and pulmonary arterial pressure, and it is characterized by pulmonary endothelial dysfunction, pulmonary artery media thickening, pulmonary vascular remodeling, and right ventricular hypertrophy, all of which are driven by an imbalance between the growth and death of pulmonary vascular cells. Programmed cell death (PCD), different from cell necrosis, is an active cellular death mechanism that is activated in response to both internal and external factors and is precisely regulated by cells. More than a dozen PCD modes have been identified, among which apoptosis, autophagy, pyroptosis, ferroptosis, necroptosis, and cuproptosis have been proven to be involved in the pathophysiology of PH to varying degrees. This article provides a summary of the regulatory patterns of different PCD modes and their potential effects on PH. Additionally, it describes the current understanding of this complex and interconnected process and analyzes the therapeutic potential of targeting specific PCD modes as molecular targets.