Neutrophil extracellular traps promoting fibroblast activation and aggravating limb ischemia through Wnt5a pathway.

Although the formation of NETs contributes to cancer cell invasion and distant metastasis, its role in the pathological progression of limb ischemia remains unknown. This study investigated the functional significance of NETs in cell-cell crosstalk during limb ischemia. The changes of cell subsets in lower limb ischemia samples were detected by single-cell RNA sequencing. The expression of neutrophil extracellular traps (NETs) related markers in lower limb ischemia samples was detected by immunohistochemistry and Western blotting. The signaling pathway of NETs activation in fibroblasts was verified by immunofluorescence, PCR and Western blotting. Through single-cell RNA sequencing (scRNA-seq), we identified 9 distinct cell clusters, with significantly upregulated activation levels in fibroblasts and neutrophils and phenotypic transformation of smooth muscle cells (SMCs) into a proliferative state in ischemic tissue. At the same time, the interaction between fibroblasts and smooth muscle cells was significantly enhanced in ischemic tissue. NETs levels rise and fibroblast activation is induced in ischemic conditions. Mechanistically, activated fibroblasts promote smooth muscle cell proliferation through the Wnt5a pathway. In ischemic mice, inhibition of Wnt5a mitigated vascular remodeling and subsequent ischemia. These findings highlighting the role of cell-cell crosstalk in ischemia and vascular remodeling. We found that the NETs-initiated fibroblast-SMC interaction is a critical regulator of limb ischemia via Wnt5a pathway, a potential therapeutic target for the treatment.

Abdominal Penetrating Aortic Ulcer and Endovascular Treatments: A Systematic Review and Meta-Analysis.

BACKGROUND: Abdominal penetrating aortic ulcer (aPAU) is defined as an ulceration of the aortic intima and media lamina, even with rupture of the internal elastic lamina. Recently, there have been an increasing number of publications on endovascular treatment for aPAU. This review aimed to assess the efficacy and safety of endovascular treatment and provide clinicians with the latest evidence-based medical data. METHODS: 3 academic databases (Embase, PubMed, and Scopus) were systematically searched for literature reporting on aPAU from 1986 (the earliest appearance of the concept of aPAU) to September 1, 2021, and related data were collected and evaluated. A fixed/random effects model was used to construct the forest plots. Funnel plots and linear regression tests were used to assess the publication bias. RESULTS: 6 articles including 121 patients were included in the analysis. The average age was 71.4 years, with 72.7% of males and 85.6% with hypertension. Saccular aneurysms (SA) were the most prevalent complication (35.5%). Endovascular treatment had a perioperative mortality rate of .24% (95% CI, .00-2.70). The technical success rate was 99.15% (95% CI, 96.49-100). The type-II endoleak rate was 5.69% (95% CI, .00-12.13). The 1-year survival rate was 95.69% (95% CI, 90.49-100). The revascularization rate was 7.20% (95% CI, .07-14.32). Endovascular treatments for aPAU would lead to a high rate of technical success, few complications, and satisfactory 1-year survival. CONCLUSIONS: aPAU are a common disease that mainly affects elderly males with hypertension and hyperlipidemia. Endovascular treatment is required when an ulcer progresses rapidly or manifests symptoms. Endovascular treatment is associated with high technical success, low complication, and satisfactory 1-year survival. Further investigation into the long-term results of endovascular treatment is necessary.

CD34+ cell-derived fibroblast-macrophage cross-talk drives limb ischemia recovery through the OSM-ANGPTL signaling axis.

CD34+ cells improve the perfusion and function of ischemic limbs in humans and mice. However, there is no direct evidence of the differentiation potential and functional role of these cells in the ischemic muscle microenvironment. Here, we combined the single-cell RNA sequencing and genetic lineage tracing technology, then provided exact single-cell atlases of normal and ischemic limb tissues in human and mouse, and consequently found that bone marrow (BM)-derived macrophages with antigen-presenting function migrated to the ischemic site, while resident macrophages underwent apoptosis. The macrophage oncostatin M (OSM) regulatory pathway was specifically turned on by ischemia. Simultaneously, BM CD34+-derived proregenerative fibroblasts were recruited to the ischemia niche, where they received macrophage-released OSM and promoted angiopoietin-like protein-associated angiogenesis. These findings provided mechanisms on the cellular events and cell-cell communications during tissue ischemia and regeneration and provided evidence that CD34+ cells serve as fibroblast progenitors promoting tissue regeneration.

Peripheral vascular remodeling during ischemia.

About 230 million people worldwide suffer from peripheral arterial disease (PAD), and the prevalence is increasing year by year. Multiple risk factors, including smoking, dyslipidemia, diabetes, and hypertension, can contribute to the development of PAD. PAD is typically characterized by intermittent claudication and resting pain, and there is a risk of severe limb ischemia, leading to major adverse limb events, such as amputation. Currently, a major progress in the research field of the pathogenesis of vascular remodeling, including atherosclerosis and neointima hyperplasia has been made. For example, the molecular mechanisms of endothelial dysfunction and smooth muscle phenotype switching have been described. Interestingly, a series of focused studies on fibroblasts of the vessel wall has demonstrated their impact on smooth muscle proliferation and even endothelial function via cell-cell communications. In this review, we aim to focus on the functional changes of peripheral arterial cells and the mechanisms of the pathogenesis of PAD. At the same time, we summarize the progress of the current clinical treatment and potential therapeutic methods for PAD and shine a light on future perspectives.

Potential Target miR-455 Delaying Arterial Stenosis Progression Through PTEN.

Background: Vascular smooth muscle cells (VSMC) underwent phenotypic switching upon stimulation signals, and this is the prerequisite for their proliferation and migration. Previous work revealed that miR-455 may be involved in vascular stenosis. Thus, this study aimed to explore potential targets and mechanisms underlying the dynamics of miR-455 in vascular stenosis. Methods: miR-455 and PTEN expression levels were studied in normal and stenosis tissue, as well as in VSMC in proliferation model. Manipulating miR-455 expression levels was achieved by transfection of either miR-455 mimic or inhibitor, and its effect on cell proliferation was studied by CCK-8 assay. Its effect on gene expression was studied by RT-qPCR and western blot. The expression regulation mechanism was studied by luciferase reporter system. Finally, the effect of miR-455 on regulating vascular stenosis was studied using a rat balloon-injured carotid artery stenosis model. Results: High expression levels of miR-455 were detected in both stenosis arterial tissues and VSMC proliferation models. In contrast, the expression levels of PTEN were downregulated in these systems. miR-455 transfected VSMC showed higher levels of proliferation and decreased levels of PTEN. Potential binding sites between miR-455 and PTEN 3'UTR were predicted and confirmed. NF-kB p65 was found to bind directly on miR-455 promoter region and regulate its transcription. The progression of arterial stenosis could be delayed by introducing miR-455 antagomir. Conclusions: The p65/miR-455/PTEN signaling pathway plays a crucial role in regulating VSMC proliferation and vascular stenosis. This indicated that miR-455 is a novel target that would help improve treatment outcomes in patients suffering from vascular stenosis.

Mediastinal liposarcoma masquerading as penetrating aortic ulcer in the descending aorta: a case report.

A 56-year-old woman with a history of hypertension and cerebral infarction was admitted to the hospital complaining of progressive and severe chest pain for 1 day. CT scan revealed a descending penetrating ulcer. Accordingly, she underwent an uneventful endovascular repair with a thoracic endograft. One month later the patient presented to our clinic with chest and back pain again. The contrast CT indicated that the periaortic mass grew larger, which interpreted as hematoma resulting from endoleak. But no endoleak was found by angiography. CT-guided needle biopsy was carried out, the histology of the mass revealed a pleomorphic liposarcoma. Liposarcomas are malignant fat-containing tumors derived from mesenchymal cells that typically occur in the extremities and retroperitoneum, mediastinal liposarcoma account for less than 1% in mediastinal malignancies; pleomorphic liposarcoma is the least common liposarcomas. Cases of liposarcoma invading vascular system are seldom, to our knowledge, it is the first case of mediastinal pleomorphic liposarcoma invaded the descending aorta. It is worth mentioning that in the modern endovascular era, the majority of aortic diseases are being repaired by endovascular techniques. When patients with growing periaortic mass post endovascular repair and endograft-related causes have been excluded, the rare possibility of mediastinal liposarcoma should arise as a differential diagnosis. Promptly CT-guided biopsy help establish an early diagnosis.

Long noncoding RNA H19 promotes vascular remodeling by sponging let-7a to upregulate the expression of cyclin D1.

Vascular remodeling is mainly caused by excessive proliferation of vascular smooth muscle cells (VSMCs). Noncoding RNAs (ncRNAs) have emerged as important regulators in diverse pathological processes. Previous work has shown the functions and mechanisms of long noncoding RNA H19 (LncRNA H19) on VSMCs. As long noncoding RNAs (lncRNAs) are complex in their mechanisms of action, the aim of the study is to identify if there are any other molecular mechanisms of LncRNA H19 on VSMCs. In vivo studies demonstrated that cyclin D1 was overexpressed in neointima of balloon-injured artery. In vitro studies identified that the overexpression of LncRNA H19 promoted VSMCs proliferation and cyclin D1 upregulation. On the contrary, cellular proliferation and expression of cyclin D1 were inhibited in VSMCs after infection with let-7a. Furthermore, luciferase reporter assays and RNA pull-down assays were used to explore the regulatory mechanism, we found that LncRNA H19 functioned as a competing endogenous RNA (ceRNA) by sponging let-7a to promote the expression of the target gene cyclin D1. In conclusion, LncRNA H19 positively regulated cyclin D1 expression through directly binding to let-7a in VSMCs. Our findings provide new insight into the mechanism of LncRNA H19 in VSMCs proliferation and vascular remodeling, and further indicate the implications of LncRNA H19 in the diagnosis and treatment of vascular proliferative diseases.

High expression of microRNA­31 and its host gene LOC554202 predict favorable outcomes in patients with colorectal cancer treated with oxaliplatin.

The expression levels of microRNA­31 (miR­31) and LOC554202 have been previously investigated in colorectal cancer (CRC) and their oncogenic and/or tumor suppressive roles have been described. The aim of the present study was to examine the role of miR­31 and its host gene LOC554202 in the prognosis of patients with CRC. Patients with CRC treated with oxaliplatin­based chemotherapy between June 2005 and March 2010 were recruited to the First Affiliated Hospital of China Medical University. Tumor and adjacent mucosal tissues were collected. The detection of miR­31 and/or LOC554202 was performed with probe hybridization targeting. Correlation analysis was performed among the expression levels of miR­31, LOC554202, and their association with clinicopathological parameters and/or survival rates. miR­31 and LOC554202 were expressed at high levels in CRC (P<0.01) compared with adjacent intestinal mucosa. A linear correlation was noted for the two markers in CRC tissues (P<0.01). The expression of miR­31 was significantly higher in adenocarcinoma than in the adjacent intestinal mucosa (P<0.01), whereas the expression of LOC554202 was significantly higher in the adenocarcinoma and the rectal cancer tissue regions (P<0.01). The high expression levels of miR­31 and LOC554202 were associated with high disease­free survival (DFS) and overall survival (OS) rates (P<0.05). Associations between the increase in DFS and OS and the elevated expression levels of miR­31 and LOC554202 were present in patients with colon cancer but not in patients with rectal cancer (P<0.05). These data indicated that miR­31 and LOC554202 may be potential markers for evaluation of the prognosis of patients treated with oxaliplatin­based chemotherapy.

Long noncoding RNA H19-derived miR-675 aggravates restenosis by targeting PTEN.

Restenosis is mainly attributed to excessive proliferation of vascular smooth muscle cells (VSMCs). Noncoding RNAs have been identified as key regulators of diverse pathological processes. We reported that the long noncoding RNA H19 (LncRNA H19) and LncRNA H19-derived microRNA (miR-675) are overexpressed in neointima of balloon-injured artery. Thus, the present study aims to evaluate the role of LncRNA H19 on VSMCs proliferation. To determine the changes of LncRNA H19 and miR-675 expression in the injured arterial wall, the standard rat carotid artery balloon injury model was used. In vivo studies demonstrated that both LncRNA H19 and miR-675 were upregulated after vascular injury. Correlation analysis revealed a positive relationship between LncRNA H19/miR-675 and the ratio of intima to media. Gain-of-function studies showed that the overexpression of LncRNA H19 accelerated T/G HA-VSMC proliferation in vitro. We further validated that PTEN is the target gene of miR-675 as demonstrated by luciferase assay. Finally, the results of the rescue experiment indicated that LncRNA H19 promoted the proliferation of T/G HA-VSMC in a miR-675-dependent manner. This finding not only reveal a novel function of LncRNA H19, but also has important diagnostic and therapeutic implications in the setting of restenosis and perhaps other vascular proliferative disorders as well.

Proliferation of vascular smooth muscle cells under inflammation is regulated by NF-κB p65/microRNA-17/RB pathway activation.

Inflammation and excessive proliferation of vascular smooth muscle cells (VSMCs) have key roles in various vascular disorders, including restenosis, atherosclerosis and pulmonary artery hypertension. However, the underlying mechanism remains unclear. The present study investigated the role of nuclear factor-κB (NF-κB) and microRNA (miRNA) in the regulation of VSMC proliferation under inflammatory conditions. It was demonstrated that miR­17 stimulated the proliferation of VSMCs, enhanced cell cycle G1/S transition, and increased levels of proliferating cell nuclear antigen and E2F1. By directly targeting the retinoblastoma (RB) protein mRNA-3' untranslated region, miR­17 suppressed the expression of RB. Activation of NF-κB p65 resulted in increased miR­17 expression in VSMCs, whereas inactivation of NF-κB p65 resulted in decreased expression of miR­17 in VSMCs. NF-κB p65 signalling directly regulates miR­17 promoter activity. NF-κB p65 activation also suppressed RB expression, which was abrogated by miR­17 inhibitor. Taken together, the present results indicated that VSMC proliferation is regulated by activation of the NF-κB p65/miR­17/RB pathway. As NF-κB p65 signalling is activated in and is a master regulator of the inflammatory response, the present findings may provide a mechanism for the excessive proliferation of VSMCs under inflammation during vascular disorders and may identify novel targets for the treatment of vascular diseases.