PKCδ regulates the vascular biology in diabetic atherosclerosis.

Diabetes mellitus, known for its complications, especially vascular complications, is becoming a globally serious social problem. Atherosclerosis has been recognized as a common vascular complication mechanism in diabetes. The diacylglycerol (DAG)-protein kinase C (PKC) pathway plays an important role in atherosclerosis. PKCs can be divided into three subgroups: conventional PKCs (cPKCs), novel PKCs (nPKCs), and atypical PKCs (aPKCs). The aim of this review is to provide a comprehensive overview of the role of the PKCδ pathway, an isoform of nPKC, in regulating the function of endothelial cells, vascular smooth muscle cells, and macrophages in diabetic atherosclerosis. In addition, potential therapeutic targets regarding the PKCδ pathway are summarized. Video Abstract.

The Role of TGF-ß Signaling in Saphenous Vein Graft Failure after Peripheral Arterial Disease Bypass Surgery.

Saphenous vein bypass grafting is an effective technique used to treat peripheral arterial disease (PAD). However, restenosis is the major clinical challenge for the graft vessel among people with PAD postoperation. We hypothesize that there is a common culprit behind arterial occlusion and graft restenosis. To investigate this hypothesis, we found TGF-ß, a gene specifically upregulated in PAD arteries, by bioinformatics analysis. TGF-ß has a wide range of biological activities and plays an important role in vascular remodeling. We discuss the molecular pathway of TGF-ß and elucidate its mechanism in vascular remodeling and intimal hyperplasia, including EMT, extracellular matrix deposition, and fibrosis, which are the important pathways contributing to stenosis. Additionally, we present a case report of a patient with graft restenosis linked to the TGF-ß pathway. Finally, we discuss the potential applications of targeting the TGF-ß pathway in the clinic to improve the long-term patency of vein grafts.

Cervical vagal nerve schwannoma induced arrhythmia: a rare case report and literature review.

BACKGROUND: Schwannomas are benign tumors deriving from the sheath of cranial and peripheral nerves. The vagus nerve is comprised of a complex neuro-endocrine-immune network that maintains homeostasis, most tracts of it play a role in parasympathetic activity. We present an example of a rare cervical vagal schwannoma case accompanied by arrhythmia. CASE PRESENTATION: A 35-year-old female patient with a left cervical vagus schwannoma and ventricular arrhythmia underwent schwannoma resection in the operating room. The patient's suppressed heart rate increased after tumor removal, and the cardiac rhythm returned to normal postoperatively. Pathological examination demonstrated the diagnosis of schwannoma. CONCLUSIONS: This case explains the link between the vagus nerve and the cardiovascular system, proving that a damaged cervical vagus nerve can inhibit the heart rate and lead to arrhythmias, and eventually requiring surgical intervention.

1α,25-Dihydroxyvitamin D3 Encapsulated in Nanoparticles Prevents Venous Neointimal Hyperplasia and Stenosis in Porcine Arteriovenous Fistulas.

BACKGROUND: Few therapies prevent venous neointimal hyperplasia (VNH) and venous stenosis (VS) formation in arteriovenous fistulas (AVF). Expression of the immediate early response gene X-1 (Iex-1), also known as Ier3, is associated with VNH and stenosis in murine AVFs. The study aimed to determine if local release of Ier3 long-acting inhibitor 1α,25(OH)2D3 from poly(lactic-co-glycolic acid) (PLGA) nanoparticles embedded in a thermosensitive Pluronic F127 hydrogel (1,25 NP) could affect VNH/VS formation in a large animal model. METHODS: Immediately after AVF creation in a porcine model of renal failure, 1,25 NP or vehicle control was injected into the adventitia space of AVF outflow veins. Scanning electron microscopy and dynamic light scattering characterized drug and control nanoparticles. Animals were sacrificed 3 and 28 days later for gene expression, immunohistologic, magnetic resonance imaging and angiography, and ultrasound analyses. Whole transcriptome RNA sequencing with differential gene expression analysis was performed on outflow veins of AVF. RESULTS: Encapsulation of 1α,25(OH)2D3 in PLGA nanoparticles formed nanoparticles of uniform size that were similar to nanoparticles without 1α,25(OH)2D3. The 1,25 NP-treated AVFs exhibited lower VNH/VS, Ier3 gene expression, and IER-3, MCP-1, CD68, HIF-1α, and VEGF-A immunostaining, fibrosis, and proliferation. Blood flow and lumen area increased significantly, whereas peak systolic velocity and wall shear stress decreased. Treatment increased Young's modulus and correlated with histologic assessment of fibrosis and with no evidence of vascular calcification. RNA sequencing analysis showed changes in the expression of genes associated with inflammatory, TGFß1, and apoptotic pathways. CONCLUSIONS: Local release of 1,25 NP improves AVF flow and hemodynamics, and reduces stenosis in association with reduction in inflammation, apoptosis, and fibrosis in a porcine model of arteriovenous fistula.

Therapeutic Effect of Adipose Derived Mesenchymal Stem Cell Transplantation in Reducing Restenosis in a Murine Angioplasty Model.

BACKGROUND: Percutaneous transluminal angioplasty (PTA) is the first line of treatment for stenosis in the arteriovenous fistula (AVF) created to provide access for hemodialysis, but resenosis still occurs. Transplants of adipose-derived mesenchymal stem cells (AMSCs) labeled with green fluorescent protein (GFP) to the adventitia could reduce pro-inflammatory gene expression, possibly restoring patency in a murine model of PTA for venous stenosis. METHODS: Partial nephrectomy of male C57BL/6J mice induced CKD. Placement of the AVF was 28 days later and, 14 days after that, PTA of the stenotic outflow vein was performed with delivery of either vehicle control or AMSCs (5×105) to the adventitia of the vein. Mice were euthanized 3 days later and gene expression for interleukin-1 beta (IL-1ß) and tumor necrosis factor-alpha TNF-α) analyzed, and histopathologic analysis performed on day 14 and 28. GFP (+) AMSCs were tracked after transplantation for up to 28 days and Doppler ultrasound performed weekly after AVF creation. RESULTS: Gene and protein expression of IL-1ß and TNF-α, fibrosis, proliferation, apoptosis and smooth muscle actin decreased, and the proportions of macrophage types (M2/M1) shifted in a manner consistent with less inflammation in AMSC-transplanted vessels compared to controls. After PTA, AMSC-treated vessels had significantly higher wall shear stress, average peak, and mean velocity, with increased lumen vessel area and decreased neointima/media area ratio compared to the control group. At 28 days after delivery, GFP (+) AMSC were present in the adventitia of the outflow vein. CONCLUSIONS: AMSC-treated vessels had improved vascular remodeling with decreased proinflammatory gene expression, inflammation, and fibrotic staining compared to untreated vessels.

Increased fibrotic signaling in a murine model for intra-arterial contrast-induced acute kidney injury.

Contrast-induced acute kidney injury (CI-AKI) is a vexing problem, and more than 70 million patients undergo studies using iodinated contrast. The molecular mechanisms responsible for CI-AKI are poorly understood. The goal of the present article was to determine the role of transforming growth factor-ß1 (TGF-ß1)/mothers against decapentaplegic homolog (SMAD)3 and associated collagen expression in a murine model of intra-arterial CI-AKI. The murine model of CI-AKI after intra-arterial contrast agent administration was created by first performing a partial nephrectomy to induce chronic kidney disease. Twenty-eight days later, 100 µL of contrast agent [iodixanol (320 mg/mL)] or saline were administered via the carotid artery. Two days after contrast administration, compared with saline, average serum creatinine was significantly elevated (P < 0.05). In the cortex, there was a significant increase in phosphorylated SMAD3 and gene expression of TGF-ß1, TGF-ß receptor type I, and TGF-ß receptor type II at day 2 in the contrast group compared with the saline group. Average gene expressions of connective tissue growth factor, matrix metalloproteinase-2 and -9, and collagen type I-α and type IV-α were significantly increased at 2 days after contrast administration (all P < 0.05). Moreover, there was a decrease in Ki-67 staining in the cortex, with an increase in terminal deoxynucleotidyl transferase dUTP nick-end labeling in the cortex and medulla after contrast administration (P < 0.05). In the murine intra-arterial CI-AKI model, there was increased hypoxia and TGF-ß1/SMAD3 pathway activation and collagen expression, resulting in renal fibrosis. Together, these results suggest that the TGF-ß1/SMAD3 pathway could be a potential target in alleviating tissue fibrosis in CI-AKI.

Effect of sex differences in treatment response to angioplasty in a murine arteriovenous fistula model.

Failure to mature and venous neointimal hyperplasia formation are the two major causes of hemodialysis arteriovenous fistula (AVF) vascular access failure. Percutaneous transluminal angioplasty (PTA) is the firstline treatment for both of these conditions, but, clinically, women have decreased patency rates compared with men. The hypothesis to be tested in the present study was that female mice after PTA of venous areas of higher intimal thickening have increased gene expression of transforming growth factor-ß1 (TGF-ß1) and TGF-ß receptor 1 (TGFß-R1) accompanied with histological changes of fibrosis compared with male mice. Seventeen male and eighteen female C57BL/6J mice were used in this study. Chronic kidney disease was induced by partial nephrectomy, and, 28 days later, an AVF was created to connect the left carotid artery to the right jugular vein. Two weeks later, the higher intimal thickening area was treated with PTA, and mice were euthanized 3 days later for gene expression analysis or 14 days later for histopathological analysis. Doppler ultrasound was performed weekly after AVF creation. At day 3, female AVF had significantly higher average gene expression of TGF-ß1 and TGFß-R1 compared with male AVF. At day 14, female outflow veins had a smaller venous diameter, lumen vessel area, decreased wall shear stress, lower average peak systolic velocity, and an increased neointima area-to-media area ratio. Moreover, female outflow veins showed a significant increase in α-smooth muscle actin and fibroblast-specific protein-1. There was a decrease in M1/M2 with an increase in CD68.

The Role of MicroRNA-21 in Venous Neointimal Hyperplasia: Implications for Targeting miR-21 for VNH Treatment.

The molecular mechanism of hemodialysis access arteriovenous fistula (AVF) failure due to venous neointimal hyperplasia (VNH) is not known. The role of microRNA-21 (miR-21) in VNH associated with AVF failure was investigated by performing in vivo and in vitro experiments. In situ hybridization results revealed that miR-21 expression increased and was associated with fibroblasts in failed AVFs from patients. In a murine AVF model, qRT-PCR gene expression results showed a significant increase in miR-21 and a decrease in miR-21 target genes in graft veins (GVs) compared to contralateral veins in mouse AVF. miR-21 knockdown in GVs was performed using a lentivirus-mediated small hairpin RNA (shRNA), and this improved AVF patency with a decrease in neointima compared to control GVs. Moreover, loss of miR-21 in GVs significantly decreased the Tgfß1, Col-Ia, and Col-Iva genes. Immunohistochemistry demonstrated a significant decrease in myofibroblasts and proliferation with an increase in terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining in miR-21-knockdown vessels, along with a decrease in hypoxia-inducible factor-1 alpha (HIF-1α) and phospho-SMAD2 (pSMAD-2) and phospho-SMAD3 (pSMAD-3) and an increase in phosphatase and tensin homolog (PTEN) staining. Hypoxic fibroblast knockdown for miR-21 showed a significant decrease in Tgfß-1 expression and pSMAD-2 and -3 levels and a decrease in myofibroblasts. These results indicate that miR-21 upregulation causes VNH formation by fibroblast-to-myofibroblast differentiation.

HDAC3 modulates cancer immunity via increasing PD-L1 expression in pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) is the second leading cause of cancer-related deaths worldwide. Despite immune checkpoints based immunotherapy highlights a new therapeutic strategy and achieves a remarkable therapeutic effect in various types of malignant tumors. Pancreatic cancer is one of the non-immunogenic cancers and is resistant to immunotherapy. Programmed death ligand 1 (PD-L1) is expressed on the surface of tumor cells and its level is a key determinant of the checkpoint immunotherapy efficacy. Here, we reported that the specific inhibitor of histone deacetylase 3 (HDAC3) decreased the protein and mRNA level of PD-L1 in pancreatic cancer cells. Furthermore, we showed that HDAC3 was critical for PD-L1 regulation and positively correlated with PD-L1 in PDAC patient specimens. Finally, we demonstrated that HDAC3/signal transducer and activator of transcription 3 (STAT3) pathway transcriptionally regulated PD-L1 expression. Collectively, our data contributes to a better understanding of the function of HDAC3 in cancer immunity and the regulatory mechanism of PD-L1. More importantly, these data suggest that the HDAC3 inhibitors might be used to improve immunotherapy in pancreatic cancer.

Evaluation of Venous Stenosis Angioplasty in a Murine Arteriovenous Fistula Model.

PURPOSE: To develop a clinically relevant model of percutaneous transluminal angioplasty (PTA) of venous stenosis in mice with arteriovenous fistula (AVF); to test the hypothesis that there is increased wall shear stress (WSS) after PTA; and to histologically characterize the vessels. MATERIALS AND METHODS: Thirteen C57BL/6J male mice, 6-8 weeks old, underwent partial nephrectomy to create chronic kidney disease. Twenty-eight days later, an AVF was created from the right external jugular vein to the left carotid artery. Fourteen days later, an angioplasty or sham procedure was performed, and the mice were sacrificed 14 days later for histologic evaluation to identify the cells contributing to the vascular remodeling (α-SMA, FSP-1, CD31, and CD68), proliferation (Ki-67), cell death (TUNEL), and hypoxia staining (HIF-1α). Histomorphometric analysis was performed to assess lumen area, neointima+media area, and cellular density. Ultrasound was performed weekly after creation of the AVF. RESULTS: Venous stenosis occurred 14 days after the creation of an AVF. PTA-treated vessels had significantly higher WSS; average peak systolic velocity, with increased lumen vessel area; and decreased neointima + media area compared to sham controls. There was a significant decrease in the staining of smooth muscle cells, fibroblasts, macrophages, HIF-1α, proliferation, and apoptosis and an increase in CD31-(+) cells. CONCLUSIONS: A clinically relevant model of PTA of venous stenosis in mice was created. PTA-treated vessels had increased lumen vessel area and WSS. The alterations in tissue markers of vascular remodeling, tissue hypoxia, proliferation, and cell death may be implications for future design of drug and device development.

[Promoting effects and mechanisms of prostaglandin E1 on proliferation and migration of endothelial cells].

OBJECTIVE: To investigate the mechanism(s) that prostaglandin E1 (PGE1) promotes human umbilical vein endothelial cell (HUVEC)proliferation and migration. METHODS: Western blot, enzyme linked immunosorbent assay, cell proliferation and cell migration tests, and tube formation were used for analyzing the roles and mechanisms of PGE1 on HUVEC; Western blot was used for analyzing the effects of PGE1 on the expression of vascular endothelial growth factor (VEGF) in rat aortic vascular smooth muscle cells (VSMC). RESULTS: PGE1 significantly increased VEGF expression of HUVEC in time and a dose dependent manner with concomitantly increased HUVEC proliferation; treatment of HUVEC with Bevacizumab apparently suppressed PGE1-stimulated VEGF expression, which led to decreased tube formation, reduced cell proliferation and migration by 41% and 38%, respectively, compared with PGE1 treatment alone; PGE1 time-dependently induced both phosphorylation of ERK and p38 in HUVEC, whereas ERK inhibitor, PD98059, or p38 inhibitor, SB203580, blocked PGE1-induced VEGF expression of HUVEC, resulting in dramatically suppression of HUVEC proliferation and migration compared with PGE1 treatment alone (60% and 55% by PD98059, 62% and 51% by SB203580, respectively); in addition, cAMP-dependent protein kinase A inhibitor, H89 or Rp-cAMP blocked PGE1-induced VEGF expression in VSMC. CONCLUSION: PGE1 promotion of proliferation, migration and tube formation of HUVEC via VEGF further provides a novel theoretical support in efficacy of PGE1 treatment of critical limb ischemia and other related diseases.

Posttraumatic arteriovenous fistula of the lower extremity and the pathological characteristic-case series and literature review.

The clinical presentation, treatment history, and outcomes of two patients with posttraumatic arteriovenous fistula (PTAVF) were analyzed and compared with the pathological tissues of patients with hemodialysis arteriovenous fistula (HAVF). A search of the biomedical literature database (PubMed), using the keywords " lower extremity" and "PTAVF," was conducted to obtain results and review the data. Postoperative histological analysis of patients with PTAVF showed differences from that of HAVF. The literature screening and analysis revealed that PTAVF is a chronic progressive process, with 70% of patients diagnosed after 3 months. The choice of treatment revealed that 20% of patients had severe complications and all were treated endovascularly. Due to the abnormal fistula of PTAVF and its specific histopathological features, the disease is not self-limiting. It is unwise to wait for PTAVF to cause "failure." We recommend early and timely cure of this disease by surgery to avoid serious complications.

Identification and Validation of PTGS2 Gene as an Oxidative Stress-Related Biomarker for Arteriovenous Fistula Failure.

(1) Background: Arteriovenous fistulas (AVFs) are the preferred site for hemodialysis. Unfortunately, approximately 60% of patients suffer from AVF failure within one year. Oxidative stress plays an important role in the occurrence and development of AVF. However, the underlying mechanisms remain unclear. Therefore, specific oxidative stress-related biomarkers are urgently needed for the diagnosis and treatment of AVF failure. (2) Methods: Bioinformatics analysis was carried out on dataset GSE119296 to screen for PTGS2 as a candidate gene related to oxidative stress and to verify the expression level and diagnostic efficacy of PTGS2 in clinical patients. The effects of NS398, a PTGS2 inhibitor, on hemodynamics, smooth muscle cell proliferation, migration, and oxidative stress were evaluated in a mouse AVF model. (3) Results: Based on 83 oxidative stress-related differentially expressed genes, we identified the important pathways related to oxidative stress. PTGS2 may have diagnostic and therapeutic efficacy for AVF failure. We further confirmed this finding using clinical specimens and validation datasets. The animal experiments illustrated that NS398 administration could reduce neointimal area (average decrease: 49%) and improve peak velocity (average increase: 53%). (4) Conclusions: Our study identified PTGS2 as an important oxidative stress-related biomarker for AVF failure. Targeting PTGS2 reduced oxidative stress and improved hemodynamics in an AVF mouse model.

Ferroptosis in Cardiovascular Diseases: Current Status, Challenges, and Future Perspectives.

Cardiovascular diseases (CVDs) are still a major cause of global mortality and disability, seriously affecting people's lives. Due to the severity and complexity of these diseases, it is important to find new regulatory mechanisms to treat CVDs. Ferroptosis is a new kind of regulatory cell death currently being investigated. Increasing evidence showed that ferroptosis plays an important role in CVDs, such as in ischemia/reperfusion injury, heart failure, cardiomyopathy, and atherosclerosis. Protecting against CVDs by targeting ferroptosis is a promising approach; therefore, in this review, we summarized the latest regulatory mechanism of ferroptosis and the current studies related to each CVD, followed by critical perspectives on the ferroptotic treatment of CVDs and the future direction of this intriguing biology.

CXCR4+ Sorted Adipose-Derived Stem Cells Enhance Their Functional Benefits and Improve Cardiac Function after Myocardial Infarction.

Objective: The homing of adipose-derived stem cells (ASCs) to infarcted myocardium, which is important for improved cardiac function, has been investigated previously, but with poor efficiency. Substantial improvements in engraftments are required to optimize ASC treatment. Stromal derived factor-1α (SDF-1α) is upregulated early after MI, and its endogenous receptor, chemokine receptor 4 (CXCR4), is pivotal in stem cell survival, migration, and engraftment. We examined whether CXCR4+ ASCs enhance their efficacy of migration and engraftment posttransplantation and improve heart function following myocardial infarction (MI). Methods and Results: CXCR4+ ASC subpopulations were sorted by fluorescence-activated cell sorting. CXCR4+ sorted ASCs exhibited the stronger cell viability, the faster proliferation rate, and the better migration capability in comparison with unfractionated ASCs. CXCR4+ sorted ASCs secreted a higher level of angiogenic growth factors including VEGF, HGF, and IGF-1 relative to unfractionated ASCs. Fewer apoptotic cells under oxygen-glucose deprivation were detected in CXCR4+ sorted ASCs than in unfractionated ASCs. Osteogenic and angiogenic differentiation were more pronounced in CXCR4+ sorted ASCs than in unfractionated ASCs. At 3 days after acute MI, rats were randomly allocated to receive intramyocardial injection of cell culture medium, CXCR4+ sorted ASCs, and unfractionated ASCs. Left ventricular function was assessed echocardiographically 4 weeks thereafter. Explanted hearts were then processed for the immunofluorescence detection of survived cells, quantification of angiogenesis, and cell engraftment. CXCR4+ sorted ASCs more obviously engrafted into infarcted myocardium, more markedly inhibited collagen remodeling, and more effectively improved heart function and promoted capillary formation than did unfractionated ASCs. Conclusion: CXCR4+ sorted ASCs are superior to unfractionated ASCs due to better viability, faster proliferation, more cytokine secretion, and stronger migration. CXCR4+ sorted ASCs provide better curative benefits on MI than do unfractionated ASCs and can be efficiently harvested and purified from adipose tissue, they may serve as a promising candidate for MI.

Targeting TNF-α for COVID-19: Recent Advanced and Controversies.

Recent advances in the pathophysiologic understanding of coronavirus disease 2019 (COVID-19) suggests that cytokine release syndrome (CRS) has an association with the severity of disease, which is characterized by increased tumor necrosis factor α (TNF-α), interleukin (IL)-6, IL-2, IL-7, and IL-10. Hence, managing CRS has been recommended for rescuing severe COVID-19 patients. TNF-α, one of the pro-inflammatory cytokines commonly upregulated in acute lung injury, triggers CRS and facilitates SARS-CoV-2 interaction with angiotensin-converting enzyme 2 (ACE2). TNF-α inhibitors, therefore, may serve as an effective therapeutic strategy for attenuating disease progression in severe SARS-CoV-2 infection. Below, we review the possibilities and challenges of targeting the TNF-α pathway in COVID-19 treatment.

Endovascular therapy for distal hilar renal artery aneurysm: a case report and literature review.

Renal artery aneurysm (RAA), a type of visceral aneurysm with atypical symptoms, is difficult to detect and is usually discovered incidentally by imaging examination. Hilar RAA (HRAA) represents a relatively rare subgroup of RAA that is located in the distal part of the renal artery, close to the renal parenchyma. We reported a 55-year-old woman with an HRAA measuring 19 mm × 20 mm × 20 mm. She underwent endovascular therapy with bare-metal stent implantation with nested coil embolization. She was discharged without complications. The uniqueness of this case is the aneurysm location, which was at the distal right renal artery, making it difficult to preserve the blood supply to the right kidney. The novelty of the minimally invasive technique was that this endovascular treatment not only eliminated the aneurysm, but also preserved the blood supply to the ipsilateral kidney. Endovascular therapy is effective in the management of HRAA.

Sex Differences in Arteriovenous Fistula Failure: Insights from Bioinformatics Analysis.

(1) Background: Arteriovenous fistulas (AVFs) are the preferred access for hemodialysis. Unfortunately, about 60% of patients, especially female patients, fail to receive normal dialysis within one year after surgery because of AVF failure. However, the underlying mechanisms caused by sex differences in AVF failure remain unclear. (2) Methods: We performed analysis of DEGs and functional analysis with the dataset GSE119296 to reveal the biology underlying AVF failure. Immune responses were calculated using CIBERSORT. A protein-protein interaction network and hub gene were constructed using STRING and stepwise identification of potential drugs was performed online. (3) Results: Functional analysis showed that extracellular matrix reprogramming and PI3K-AKT pathway enrichment were significant in both male and female patients. COL1A1 was the hub gene in male patients, whereas CDK1 was the hub gene in female patients. Immune responses including γδ-T cells and mast cells are activated in female patients while no significant differences were noted in the male group. (4) Conclusions: In this study, we used a series of mature and recognized bioinformatic strategies to determine the following items: (1) Reveal the pathogenesis of AVF failure through HUB genes and signaling pathways between the different sexes. (2) Determine the relationship between sex differences in AVF failure and immune abnormalities. (3) Search for relevant sex-specific drugs targeting AVF failure.