Rat Carotid Artery Research Articles

Identification of the Neointimal Hyperplasia-Related LncRNA-mRNA-Immune Cell Regulatory Network in a Rat Carotid Artery Balloon Injury Model.

Excessive neointimal hyperplasia (NIH) of coronary vessels in patients is the main cause of restenosis (RS) after percutaneous coronary intervention (PCI). This study aimed to identify the regulatory genes related to NIH in a rat carotid artery balloon injury model.We established a rat model and performed RNA sequencing to identify differentially expressed long non-coding RNAs (DElncRNAs) and differentially expressed message RNAs (DEmRNAs). Immune cells were analyzed using a murine Microenvironment Cell Population counter. The Pearson correlation between DEmRNAs, DElncRNAs, and immune cells was analyzed, followed by function enrichment analysis. Core DEmRNA was identified using Cytoscape. Next, a core lncRNAs-mRNAs-immune cell regulatory network was constructed. NIH-related gene sets from the Gene Expression Omnibus and GeneCards databases were used for validation.A total of 2,165 DEmRNAs and 705 DElncRNAs were identified in rat carotid artery tissue. Four key immune cells were screened out, including mast cells, vessels, endothelial cells, and fibroblasts. Based on the Pearson correlation between DEmRNAs, DElncRNAs and 4 key immune cells, 246 DEmRNAs and 93 DElncRNAs were obtained. DEmRNAs that interact with lncRNAs were mainly involved in the cell cycle, MAPK signaling pathway, and PI3K-Akt signaling pathway. A core lncRNA-mRNA-immune cell regulatory network was constructed, including 9 mRNAs, 4 lncRNAs, and fibroblasts. External datasets validation confirmed the significant correlation of both these mRNAs and lncRNAs with NIH.In this study, an lncRNA-mRNA-immune cell regulatory network related to NIH was constructed, which provided clues for exploring the potential mechanism of RS in cardiovascular diseases.

Modeling of Cerebral Ischemic Stroke in Conscious Rats via Arterial Air Embolization.

The etiological factor of cerebral ischemia in the vast majority of cases is vascular embolism. In the present study we investigated embolism caused by atmospheric air bubbles injected into the internal carotid artery of conscious rats. Immediately after embolism modeling, behavioral abnormalities were observed in the animals, and after 24 h, foci of brain damage were detected. The death of animals was observed within 5 days after embolism. The proposed experimental model of cerebral ischemia in conscious rats is more relevant and better corresponds to real conditions than the model on narcotized animals and allows to perform physiological tests immediately after modeling.

Intravascular delivery of an MK2 inhibitory peptide to prevent restenosis after angioplasty

Peripheral artery disease is commonly treated with balloon angioplasty, a procedure involving minimally invasive, transluminal insertion of a catheter to the site of stenosis, where a balloon is inflated to open the blockage, restoring blood flow. However, peripheral angioplasty has a high rate of restenosis, limiting long-term patency. Therefore, angioplasty is sometimes paired with delivery of cytotoxic drugs like paclitaxel to reduce neointimal tissue formation. We pursue intravascular drug delivery strategies that target the underlying cause of restenosis - intimal hyperplasia resulting from stress-induced vascular smooth muscle cell switching from the healthy contractile into a pathological synthetic phenotype. We have established MAPKAP kinase 2 (MK2) as a driver of this phenotype switch and seek to establish convective and contact transfer (coated balloon) methods for MK2 inhibitory peptide delivery to sites of angioplasty. Using a flow loop bioreactor, we showed MK2 inhibition in ex vivo arteries suppresses smooth muscle cell phenotype switching while preserving vessel contractility. A rat carotid artery balloon injury model demonstrated inhibition of intimal hyperplasia following MK2i coated balloon treatment in vivo. These studies establish both convective and drug coated balloon strategies as promising approaches for intravascular delivery of MK2 inhibitory formulations to improve efficacy of balloon angioplasty.

An arteriovenous fistula model: Carotid artery-posterior facial vein fistula in rats.

To describe an alternative arteriovenous fistula (AVF) model involving anastomosis of the common carotid artery (CCA) with the posterior facial vein (PFV). Twenty-two male Sprague-Dawley rats (age 6-8 weeks) were used to establish the AVF model involving end-to-side anastomosis of PFV and CCA. The peak velocity of the CCA and the diameter of the outflow vein were recorded at 7, 14, and 42 days after the operation using Doppler ultrasound. Pathological examination of the intimal lesions was performed at 14 and 42 days after operation. One rat died within 24 h after surgery related to anesthesia. The patency rates at days 7, 14, and 42 were 85.7%, 81%, and 81%, respectively. The diameter of the carotid artery in rats is approximately 0.8 mm. The diameter of the outflow vein was increased by 1.7-fold and 2.2-fold at 7 days (1.1 ± 0.118 mm) and 14 days (1.4 ± 0.073 mm). At 42 days (1.96 ± 0.101 mm) after operation, the diameter was 3-fold greater compared to the unoperated control rat. The peak systolic flow velocity of the carotid artery at 7 days (593 ± 17.36 mm/s) and 14 days (767 ± 13.64 mm/s) after surgery was significantly greater compared to the control rat (314 ± 15.13 mm/s). The rate of increase was fastest at 7 days and leveled off from 14 to 42 days (875 ± 26 mm/s) after surgery. At 14 days, the intima area showed a nearly 50-fold increase (230 ± 9.93 μm2 × 103) compared to control (area 5 ± 0.37 μm2 × 103). Comparing 6 weeks with 2 weeks (280 ± 10.54 μm2 × 103) after surgery, the intima area increased 1.2 times. The CCA-PFV fistula in rats is a viable alternative AVF model.

MiR-1290 induces endothelial-to-mesenchymal transition and promotes vascular restenosis after angioplasty by targeting FGF2

Background and aimsEndothelial-to-mesenchymal transition (EndMT) is an important reason for restenosis but the underlying mechanisms need to be further explored. Therefore, the purpose of this study is to screen significantly different microRNAs (miRNAs) and assess their functions and downstream pathways. MethodsThis study screened several miRNAs with significant differences between human arterial segments from restenosis patients and healthy volunteers using whole transcriptome resequencing and real-time quantitative reverse transcription PCR (qRT-PCR). We explored the correlation between miR-1290 and EndMT using Western blot, qRT-PCR, Pearson correlation analysis and further functional gain and loss experiments. Subsequently, we identified the direct downstream target of miR-1290 by bioinformatics analysis, RNA pull-down, double Luciferase reporter gene and other functional experiments. Finally, rat carotid artery balloon injury model demonstrated the therapeutic potential of miR-1290 regulator. ResultsWe screened 129 differentially expressed miRNAs. Among them, miR-1290 levels were significantly higher in restenosis arteries than in healthy arteries, and as expected, EndMT was functionally enhanced with miR-1290 overexpression and comparatively weakened when miR-1290 was knocked down. In addition, fibroblast growth factor-2 (FGF2) was established as the downstream target of miR-1290. Finally, we utilized an animal model and found that low miR-1290 levels could alleviate EndMT and the progression of restenosis. ConclusionsOur study demonstrated the strong regulatory effects of miR-1290 on EndMT, endometrial hyperplasia and restenosis, which could be useful as biomarker and therapeutic target for stent implantation in patients with arterial occlusive disease of the lower extremities.

Treadmill exercise prevents recognition memory impairment in VD rat model and enhancement of hippocampal structural synaptic plasticity.

In vascular dementia (VD), memory impairment caused by the damage of synaptic plasticity is the most prominent feature that afflicts patients and their families. Treadmill exercise has proven beneficial for memory by enhancing synaptic plasticity in animal models including stroke, dementia, and mental disorders. The aim of this study was to examine the effects of treadmill exercise on recognition memory and structural synaptic plasticity in VD rat model. Male Sprague-Dawley rats were randomly assigned into four groups: control group (C group, n=6), vascular dementia group (VD group, n=6), treadmill exercise and vascular dementia group (Exe-VD group, n=6), and treadmill exercise group (Exe group, n=6). Four-week treadmill exercise was performed in the Exe-VD and Exe groups. Then, the common carotid arteries of rats in the VD and Exe-VD groups were identified to establish the VD model. Behavior tests (open-field test and novel recognition memory test) were adopted to evaluate anxiety-like behavior and recognition memory. Transmission electron microscopy and Golgi staining were performed to observe synaptic ultrastructure and spine density in the hippocampus. Our study demonstrated that VD rat exhibited significantly anxiety-like behavior and recognition impairment (p <.01), while treadmill exercise significantly alleviated anxiety-like behavior and improved recognition memory in VD rat (p <.01). Transmission electron microscopy revealed that hippocampal synapse numbers were significantly decreased in the VD group compared to the control group (p <.05). These alterations were reversed by treadmill exercise, and the rats exhibited healthier synaptic ultrastructure, including significantly increased synapse (p <.05). Meanwhile, golgi staining revealed that the spine numbers of the hippocampus were significantly decreased in the VD group compared to the control group (p <.05). When compared with the VD group, hippocampal spine numbers were significantly increased in the Exe-VD group (p <.05). The improvement of VD-associated recognition memory by treadmill exercises is associated with enhanced structural synaptic plasticity in VD rat model.

Quercetin conjugated PSC-derived exosomes to inhibit intimal hyperplasia via modulating the ERK, Akt, and NF-κB signaling pathways in the rat carotid artery post balloon injury

The primary challenge in percutaneous coronary interventions for vascular restenosis is the occurrence of restenosis, which is defined by the excessive proliferation of neointimal tissue. Herein, our research team suggests that exosomes obtained from PSC, when paired with quercetin (Q@PSC-E), successfully reduce neointimal hyperplasia in a Sprague-Dawley rat model. Furthermore, the physical properties of the synthesized Q@PSC-E were examined using UV–vis, DLS, and FT-IR characterization techniques. The rats were subjected to balloon injury (BI) utilizing a 2-Fr Fogarty arterial embolectomy balloon catheter. Intimal hyperplasia and the degree of VSMC proliferation were evaluated using histological analysis in the rat groups that received a dosage of Q@PSC-E at 30 mg/kg/d. Significantly, Q@PSC-E inhibited cell proliferation through a pathway that does not include lipoxygenase, as demonstrated by [3H] thymidine incorporation, MTT, and flow cytometry studies. Additionally, the data indicate that Q@PSC-E hinders cell proliferation by targeting particular events that promote cell growth, including the activation of Akt and NF-κB, disruption of cell-cycle progression and also obstructs the ERK signaling pathway.

Intestinal flora influences the progression of subarachnoid hemorrhage by affecting peripheral and central inflammatory pathways

Subarachnoid hemorrhage (SAH) is a debilitating condition that leaves survivors with neurological disability for the rest of their lives. No effective treatment for early brain injury (EBI) has been developed. Gut microbiome (GM) impact the host immune system and can influence disease processes in several organs, including the brain. However, it remains unclear whether the GM has an impact on the outcome of SAH brain injury. Here, we wondered whether microbiota could relieve the injury. We changed the microbiota of 8-week-old male rats by administering antibiotic-containing water for 2 weeks. Composition of the GM was profiled by using 16S rRNA. We induced SAH by puncture the internal carotid artery of control rats and rats with altered GM. Additionally, we studied inflammatory cells using HE stains, Intestinal lymphocyte flow cytometry, and Neuroinflammatory factor WB. SAH was significantly averted by alterations in GM using antibiotics. The altered GM significantly increased the intestinal and intracranial inflammation after SAH. This was manifested by Mosin (MSN) inflammatory cytokines. Our findings demonstrated that the brain injury following SAH is associated with GM.

Bioengineered vascular grafts with a pathogenic TGFBR1 variant model aneurysm formation in vivo and reveal underlying collagen defects.

Thoracic aortic aneurysm (TAA) is a life-threatening vascular disease frequently associated with underlying genetic causes. An inadequate understanding of human TAA pathogenesis highlights the need for better disease models. Here, we established a functional human TAA model in an animal host by combining human induced pluripotent stem cells (hiPSCs), bioengineered vascular grafts (BVGs), and gene editing. We generated BVGs from isogenic control hiPSC-derived vascular smooth muscle cells (SMCs) and mutant SMCs gene-edited to carry a Loeys-Dietz syndrome (LDS)-associated pathogenic variant (TGFBR1A230T). We also generated hiPSC-derived BVGs using cells from a patient with LDS (PatientA230T/+) and using genetically corrected cells (Patient+/+). Control and experimental BVGs were then implanted into the common carotid arteries of nude rats. The TGFBR1A230T variant led to impaired mechanical properties of BVGs, resulting in lower burst pressure and suture retention strength. BVGs carrying the variant dilated over time in vivo, resembling human TAA formation. Spatial transcriptomics profiling revealed defective expression of extracellular matrix (ECM) formation genes in PatientA230T/+ BVGs compared with Patient+/+ BVGs. Histological analysis and protein assays validated quantitative and qualitative ECM defects in PatientA230T/+ BVGs and patient tissue, including decreased collagen hydroxylation. SMC organization was also impaired in PatientA230T/+ BVGs as confirmed by vascular contraction testing. Silencing of collagen-modifying enzymes with small interfering RNAs reduced collagen proline hydroxylation in SMC-derived tissue constructs. These studies demonstrated the utility of BVGs to model human TAA formation in an animal host and highlighted the role of reduced collagen modifying enzyme activity in human TAA formation.

Increases of renal sodium transporters before and after the occurrence of the hypertension in spontaneously hypertensive rats

Background: Adult spontaneously hypertensive rats (SHR) have increases of renal sodium transporters associated with hypertension. It remains to be determined whether the increases of renal sodium transporters are precede by occurrence of hypertension and reflected by urine exosomal sodium transporters that may serve as non-invasive biomarkers for the effcacy of anti-hypertensive drugs. Methods: 1. Male WKY rats and SHRs were aged of 4, 7 and 10 weeks respectively (n=5/group). 2. Additional 3 sets of 10-week-old rat (n=5/group) were administered by a 7-day intraperitoneal injections of furosemide (NKCC2 inhibitor, 5mg/kg), hydrochlorothiazide (NCC2 inhibitor, 30mg/kg) and amiloride (ENaC inhibitor, 10mg/kg) respectively. 3. The systolic blood pressure (SBP) was measured with a catheter in carotid artery of rats under anesthesia. Tail-cuff methods were used to monitor the drug responses. 4. All rats were rationally fed 0.4% NaCl agar-gelled diet for 7 days. 5. Exosomes were extracted with ultracentrifuge from the urines. Results: SHRs (4 weeks) exhibited similar SBP. The renal NKCC2, the major apical sodium transporters in thick ascending limb, was more than doubled in SHRs (215±14 % of WKY, student t-test, p&lt;0.05, same as below) while the other sodium transporters were normal. However, SHRs had a higher SBP than WKY at ages of 7 (157±10 vs 125±14, mmHg) and 10 weeks (192±8 vs 128±12). There were no differences for the all age groups in heart rate, body weight, urine volume, urine Na+ and Cl− excretion, and serum Cr, K+, Na+, and Cl− concentration between rat strains. At 10-weeks old, renal (161±24) and urine exosomal (159±21, corrected by UCr, same as below) NKCC2 were higher in SHR than WKY. Frusemide normalized SBP on day 1 (day 0: 190±18 vs 138±13; day 1: 149±13 vs 128±16) in SHR; Renal (129±9) and urine-exosomal (137±12) NCC were higher in SHR than WKY. Hydrochlorothiazide normalized SBP in SHR on day 1 (day 0: 206±4 vs 140±9; day 1: 159±11 vs 144±11). Renal (α:134±16; β:137±25) and urine-exosomal (α:153±13; β:158±12) ENaCs were higher in SHR than WKY. Amiloride diminished the difference in SBP between rat strains on day 1 (day 0: 188±18 vs 138±11; day 1: 164±16 vs 147±7). Conclusions: The increase of renal NKCC2 precedes the elevation of SBP in SHRs. Urine exosomal NKCC2, NCC, ENaCs may reflect their renal levels and be indicative of the corresponding inhibitors on the hypertension model. Natural Science Foundation of China 81970605. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Linarin Ameliorates Restenosis After Vascular Injury in Type 2 Diabetes Mellitus via Regulating ADAM10-Mediated Notch Signaling Pathway.

Vascular lesions frequently arise as complication in patients diagnosed with diabetes mellitus (DM). Presently, percutaneous coronary intervention (PCI) and antithrombotic therapy serve as primary treatments. However, in-stent restenosis persists as a challenging clinical issue following PCI, lacking sustained and effective treatment. Linarin (LN) exhibits diverse pharmacological activities and is regarded as a potential drug for treating various diseases, including DM. But its specific role in restenosis after vascular injury in DM patients remains unclear. A rat model of diabetes-related restenosis was established to evaluate the role of LN on neointimal hyperplasia. Vascular smooth muscle cells (VSMCs) stimulated by high glucose (HG, 30mM) underwent LN treatment. Additionally, an overexpression plasmid of A disintegrin and metalloproteinases (ADAM10) was constructed to transfect VSMCs. We employed CCK-8, Brdu, wound-healing scratch, and transwell migration assays to evaluate the proliferation and migration of VSMCs. Furthermore, western blot and immunofluorescence assays were utilized to investigate the expressions of ADAM10 and the downstream Notch signaling pathway in vivo and in vitro models. LN notably alleviated intimal hyperplasia after vascular injury in DM rats and reduced the protein expression of ADAM10, alongside its downstream Notch1 signaling pathway-related proteins (Notch1, NICD and Hes1) in rat carotid artery tissues. LN effectively suppressed the proliferation and migration of VSMCs induced by HG, downregulating the protein expression of ADAM10, Notch1, NICD and Hes1. Moreover, our findings indicated that ADAM10 overexpression significantly reversed LN's effects on proliferation, migration, and the expression of Notch1 signaling pathway-related proteins in HG-treated VSMCs. LN demonstrates potential therapeutic efficacy in addressing restenosis after diabetic-related vascular injury, with the ADAM10 mediated Notch signaling pathway playing a pivotal role.

Exosomal MALAT1 from macrophages treated with high levels of glucose upregulates LC3B expression via miR-204-5p downregulation.

Metastasis-associated lung adenocarcinoma transcript 1 ( MALAT1 ) plays a critical role in the pathophysiology of diabetes-related complications. However, whether macrophage-derived MALAT1 affects autophagic activity under hyperglycemic conditions is unclear. Therefore, we investigated the molecular regulatory mechanisms of macrophage-derived MALAT1 and autophagy under hyperglycemic conditions. Hyperglycemia was induced by culturing macrophages in 25 mM glucose for 1 hour. Exosomes were extracted from the culture media. A rat model of carotid artery balloon injury was established to assess the effect of MALAT1 on vascular injury. Reverse transcription, real-time quantitative polymerase chain reaction, western blotting, immunohistochemical staining, and luciferase activity assays were performed. Stimulation with high levels of glucose significantly enhanced MALAT1 expression in macrophage-derived exosomes. MALAT1 inhibited miR-204-5p expression in macrophage-derived exosomes under hyperglycemic conditions. siRNA-induced silencing of MALAT1 significantly reversed macrophage-derived exosome-induced miR-204-5p expression. Hyperglycemic treatment caused a significant, exosome-induced increase in the expression of the autophagy marker LC3B in macrophages. Silencing MALAT1 and overexpression of miR-204-5p significantly decreased LC3B expression induced by macrophage-derived exosomes. Overexpression of miR-204-5p significantly reduced LC3B luciferase activity induced by macrophage-derived exosomes. Balloon injury to the carotid artery in rats significantly enhanced MALAT1 and LC3B expression, and significantly reduced miR-204-5p expression in carotid artery tissue. Silencing MALAT1 significantly reversed miR-204-5p expression in carotid artery tissue after balloon injury. MALAT1 silencing or miR-204-5p overexpression significantly reduced LC3B expression after balloon injury. This study demonstrated that hyperglycemia upregulates MALAT1 . MALAT1 suppresses miR-204-5p expression and counteracts the inhibitory effect of miR-204-5p on LC3B expression in macrophages to promote vascular disease.

Periodization of adaptation-compensatory remodeling of brain structures in incomplete permanent cerebral hypoperfusion in rats

Bilateral one-stage ligation of the common carotid arteries in rats is the most common method of forming prolonged cerebral hypoxia with cognitive impairment. Pharmacological studies are most commonly performed at the early postoperative periods, up to 3 days. They are characterized by neuronal death, hypoenergetic state, and edema. In the acute period (3–8 days), changes are associated with the activation of astrocytes, which form intercellular cooperation between the neuron, hemocapillary, and respiratory burst of neutrophil granulocytes. Thus, the permeability of the blood–brain barrier increases, accompanied by the death of one part of the neurons and the improvement of the vitality of another part. The subacute period (from 8 days to 8 weeks) is accompanied by the death of neurons in a state of poor life support, microglial activation, myelin fiber damage, increased diameter of paravertebral arteries in the early period, and the development of astrocytosis and angiogenesis in the late period, which leads to increased lipid peroxidation, secondary damage, and neuronal death. In the late period, neurodystrophic changes appear, and minor neuronal apoptosis and increased permeability of the blood–brain barrier persist. Surviving neurons show metabolic activation and concentration of pericarions near the hemocapillaries.

Role of C/EBP Homologous Protein in Vascular Stenosis After Carotid Artery Injury.

The study aims to explore the fluctuating expression of C/EBP Homologous Protein (CHOP) following rat carotid artery injury and its central role in vascular stenosis. Using in vivo rat carotid artery injury models and in vitro ischemia and hypoxia cell models employing human aortic endothelial cells (HAECs) and vascular smooth muscle cells (T/G HA-VSMCs), a comprehensive investigative framework was established. Histological analysis confirmed intimal hyperplasia in rat models. CHOP expression in vascular tissues was assessed using Western blot and immunohistochemical staining, and its presence in HAECs and T/G HA-VSMCs was determined through RT-PCR and Western blot. The study evaluated HAEC apoptosis, inflammatory cytokine secretion, cell proliferation, and T/G HA-VSMCs migration through Western blot, ELISA, CCK8, and Transwell migration assays. The rat carotid artery injury model revealed substantial fibrous plaque formation and vascular stenosis, resulting in an increased intimal area and plaque-to-lumen area ratio. Notably, CHOP is markedly elevated in vessels of the carotid artery injury model compared to normal vessels. Atorvastatin effectively mitigated vascular stenosis and suppresses CHOP protein expression. In HAECs, ischemia and hypoxia-induced CHOP upregulation, along with heightened TNFα, IL-6, caspase3, and caspase8 levels, while reducing cell proliferation. Atorvastatin demonstrated a dose-dependent suppression of CHOP expression in HAECs. Downregulation of CHOP or atorvastatin treatment led to reduced IL-6 and TNFα secretion, coupled with augmented cell proliferation. Similarly, ischemia and hypoxia conditions increased CHOP expression in T/G HA-VSMCs, which was concentration-dependently inhibited by atorvastatin. Furthermore, significantly increased MMP-9 and MMP-2 concentrations in the cell culture supernatant correlated with enhanced T/G HA-VSMCs migration. However, interventions targeting CHOP downregulation and atorvastatin usage curtailed MMP-9 and MMP-2 secretion and suppressed cell migration. In conclusion, CHOP plays a crucial role in endothelial injury, proliferation, and VSMCs migration during carotid artery injury, serving as a pivotal regulator in post-injury fibrous plaque formation and vascular remodeling. Statins emerge as protectors of endothelial cells, restraining VSMCs migration by modulating CHOP expression.

Exosomes of endothelial progenitor cells repair injured vascular endothelial cells through the Bcl2/Bax/Caspase-3 pathway

The main objective of this study is to evaluate the influence of exosomes derived from endothelial progenitor cells (EPC-Exo) on neointimal formation induced by balloon injury in rats. Furthermore, the study aims to investigate the potential of EPC-Exo to promote proliferation, migration, and anti-apoptotic effects of vascular endothelial cells (VECs) in vitro. The underlying mechanisms responsible for these observed effects will also be thoroughly explored and analyzed. Endothelial progenitor cells (EPCs) was isolated aseptically from Sprague–Dawley (SD) rats and cultured in complete medium. The cells were then identified using immunofluorescence and flow cytometry. The EPC-Exo were isolated and confirmed the identities by western-blot, transmission electron microscope, and nanoparticle analysis. The effects of EPC-Exo on the rat carotid artery balloon injury (BI) were detected by hematoxylin and eosin (H&E) staining, ELISA, immunohistochemistry, immunofluorescence, western-blot and qPCR. LPS was used to establish an oxidative damage model of VECs. The mechanism of EPC-Exo repairing injured vascular endothelial cells was detected by measuring the proliferation, migration, and tube function of VECs, actin cytoskeleton staining, TUNEL staining, immunofluorescence, western-blot and qPCR. In vivo, EPC-Exo exhibit inhibitory effects on neointima formation following carotid artery injury and reduce the levels of inflammatory factors, including TNF-α and IL-6. Additionally, EPC-Exo downregulate the expression of adhesion molecules on the injured vascular wall. Notably, EPC-Exo can adhere to the injured vascular area, promoting enhanced endothelial function and inhibiting vascular endothelial hyperplasia Moreover, they regulate the expression of proteins and genes associated with apoptosis, including B-cell lymphoma-2 (Bcl2), Bcl2-associated x (Bax), and Caspase-3. In vitro, experiments further confirmed that EPC-Exo treatment significantly enhances the proliferation, migration, and tube formation of VECs. Furthermore, EPC-Exo effectively attenuate lipopolysaccharides (LPS)-induced apoptosis of VECs and regulate the Bcl2/Bax/Caspase-3 signaling pathway. This study demonstrates that exosomes derived from EPCs have the ability to inhibit excessive carotid intimal hyperplasia after BI, promote the repair of endothelial cells in the area of intimal injury, and enhance endothelial function. The underlying mechanism involves the suppression of inflammation and anti-apoptotic effects. The fundamental mechanism for this anti-apoptotic effect involves the regulation of the Bcl2/Bax/Caspase-3 signaling pathway.

Amphetamine increases vascular permeability by modulating endothelial actin cytoskeleton and NO synthase via PAR-1 and VEGF-R

Abuse of amphetamine-type stimulants is linked to cardiovascular adverse effects like arrhythmias, accelerated atherosclerosis, acute coronary syndromes and sudden cardiac death. Excessive catecholamine release following amphetamine use causes vasoconstriction and vasospasms, over time leading to hypertension, endothelial dysfunction or even cardiotoxicity. However, immediate vascular pathomechanisms related to amphetamine exposure, especially endothelial function, remain incompletely understood and were analyzed in this study. Pharmaco-pathological effects of acute d-amphetamine-sulfate (DAM) were investigated ex vivo using contraction–force measurements of rat carotid artery rings and in vitro using label-free, real-time electrochemical impedance spectroscopy (EIS) on endothelial and smooth muscle cells. Specific receptor and target blocking was used to identify molecular targets and to characterize intracellular signaling. DAM induced vasodilation represented by 29.3±2.5% decrease in vascular tone (p<0.001) involving vascular endothelial growth factor receptor (VEGF-R) and protease activated receptor 1 (PAR-1). EIS revealed that DAM induces endothelial barrier disruption (−75.9±1.1% of initial cellular impedance, p<0.001) also involving VEGF-R and PAR-1. Further, in response to DAM, Rho-associated protein kinase (ROCK) mediated reversible contraction of actin cytoskeleton resulting in endothelial barrier disruption. Dephosphorylation of Serine1177 (−50.8±3.7%, p<0.001) and Threonine495 (−44.8±6.5%, p=0.0103) of the endothelial NO synthase (eNOS) were also observed. Blocking of VEGF-R and PAR-1 restored baseline eNOS Threonine495 phosphorylation. DAM induced vasodilation, enhanced vascular permeability and actin cytoskeleton contraction and induced eNOS hypophosphorylation involving VEGF-R, PAR-1 and ROCK. These results may contribute to a better understanding of severe adverse cardiovascular effects in amphetamine abuse.

Wide dynamic range measurement of blood flow in vivo using laser speckle contrast imaging.

Laser speckle contrast imaging (LSCI) is a real-time wide-field technique that is applied to visualize blood flow in biomedical applications. However, there is currently a lack of relevant research to demonstrate that it can measure velocities over a wide dynamic range (WDR), which is critical for monitoring much higher and more pulsatile blood flow in larger size myocardial vessels, such as the coronary artery bypass graft, and visualizing the spatio-temporal evolution of myocardial blood flow perfusion in cardiac surgery. We aim to demonstrate that the LSCI technique enables measuring velocities over a WDR from phantom experiments to animal experiments. In addition, LSCI is preliminarily applied to imaging myocardial blood flow distribution in vivo on rabbits. Phantom and animal experiments are performed to verify that the LSCI method has the ability to measure blood velocities over a wide range. Our method is also validated by transit time flow measurement, which is the gold standard for blood flow measurement in cardiac surgery. Our method is demonstrated to measure the blood flow over a wide range from 0.2 to . To validate the phantom results, the varying blood flow rate from 0 to is detected in the rat carotid artery. Additionally, our technique also obtains blood flow maps of different myocardial vessels, such as superficial large/small veins, veins surrounded by fat, and myocardial deeper arteriole. Our study has the potential to visualize the spatio-temporal evolution of myocardial perfusion in coronary artery bypass grafting, which would be of great benefit for future research in the life sciences and clinical medicine.

Transfer RNA-derived small RNA tRF-Glu-CTC attenuates neointimal formation via inhibition of fibromodulin

Neointimal hyperplasia is a pathological vascular remodeling caused by abnormal proliferation and migration of subintimal vascular smooth muscle cells (VSMCs) following intimal injury. There is increasing evidence that tRNA-derived small RNA (tsRNA) plays an important role in vascular remodeling. The purpose of this study is to search for tsRNAs signature of neointima formation and to explore their potential functions. The balloon injury model of rat common carotid artery was replicated to induce intimal hyperplasia, and the differentially expressed tsRNAs (DE-tsRNAs) in arteries with intimal hyperplasia were screened by small RNA sequencing and tsRNA library. A total of 24 DE-tsRNAs were found in the vessels with intimal hyperplasia by small RNA sequencing. In vitro, tRF-Glu-CTC inhibited the expression of fibromodulin (FMOD) in VSMCs, which is a negative modulator of TGF-β1 activity. tRF-Glu-CTC also increased VSMC proliferation and migration. In vivo experiments showed that inhibition of tRF-Glu-CTC expression after balloon injury of rat carotid artery can reduce the neointimal area. In conclusion, tRF-Glu-CTC expression is increased after vascular injury and inhibits FMOD expression in VSMCs, which influences neointima formation. On the other hand, reducing the expression of tRF-Glu-CTC after vascular injury may be a potential approach to prevent vascular stenosis.

Ultrasmall catechol-PEG-anchored ferrite nanoparticles for highly sensitive magnetic resonance angiography.

Highly sensitive iron oxide nanoparticles with stable, safe and efficient surface functionalization, as potential substitutes for gadolinium-based contrast agents (GBCAs) with increasing biosafety concerns, exhibit great potential for high-performance magnetic resonance angiography (MRA). Herein, we developed ultrasmall catechol-PEG-anchored ferrite nanoparticles (PEG-UMFNPs) for highly sensitive MRA. The obtained nanoprobe has a high T1 relaxivity value (7.2 mM-1 s-1) due to its ultrasmall size and Mn doping. It has a suitable hydrodynamic size of 20 nm, which prevents rapid vascular extravasation and renal clearance and prolongs its blood circulation time. In vivo MRA at 3.0 T using the nanoprobe shows that the arteries and veins of rats, even blood vessels as small as 0.32 mm, are distinctly visible, and the contrast enhancement can last for at least 1 h. In addition, due to the outstanding contrast enhancement and long circulation time, the stenosis and recanalization process of the rat's carotid artery can be continuously monitored with a single injection of the nanoprobe. Our study indicates that PEG-UMFNPs are outstanding MR imaging nanoprobes that can be used to diagnose vascular diseases without the biosafety issues of GBCAs.

Adaptation process of decellularized vascular grafts as hemodialysis access in vivo.

Arteriovenous grafts (AVGs) have emerged as the preferred option for constructing hemodialysis access in numerous patients. Clinical trials have demonstrated that decellularized vascular graft exhibits superior patency and excellent biocompatibility compared to polymer materials; however, it still faces challenges such as intimal hyperplasia and luminal dilation. The absence of suitable animal models hinders our ability to describe and explain the pathological phenomena above and in vivo adaptation process of decellularized vascular graft at the molecular level. In this study, we first collected clinical samples from patients who underwent the construction of dialysis access using allogeneic decellularized vascular graft, and evaluated their histological features and immune cell infiltration status 5 years post-transplantation. Prior to the surgery, we assessed the patency and intimal hyperplasia of the decellularized vascular graft using non-invasive ultrasound. Subsequently, in order to investigate the in vivo adaptation of decellularized vascular grafts in an animal model, we attempted to construct an AVG model using decellularized vascular grafts in a small animal model. We employed a physical-chemical-biological approach to decellularize the rat carotid artery, and histological evaluation demonstrated the successful removal of cellular and antigenic components while preserving extracellular matrix constituents such as elastic fibers and collagen fibers. Based on these results, we designed and constructed the first allogeneic decellularized rat carotid artery AVG model, which exhibited excellent patency and closely resembled clinical characteristics. Using this animal model, we provided a preliminary description of the histological features and partial immune cell infiltration in decellularized vascular grafts at various time points, including Day 7, Day 21, Day 42, and up to one-year post-implantation. These findings establish a foundation for further investigation into the in vivo adaptation process of decellularized vascular grafts in small animal model.