Rat Carotid Artery Research Articles

Intravenous administration of apeling-13 induces a depressor response by releasing an unidentified substance

Apelin and APJ receptor play an important role in the regulating cardiovascular function; however, conflicting results have been reported regarding the effect of apelin on cardiovascular regulation. In this study, blood pressure and heart rate were measured by femoral arterial catheterization; and cardiac contractility was recorded by left ventricular catheterization through the right carotid artery in rats before and after intravenous administration of [pyr1]-apelin-13. The results show that intravenous administration of apelin-13 caused a dramatic reduction in BP but did not significantly alter heart rate and contractility. To study the mechanism of the apelin-induced depressor response, isometric tension was measured in isolated mesenteric arteries using a myograph approach. Surprisingly, treatment of the arteries with [pyr1]-apelin-13 did not cause relaxation of mesenteric arteries preconstricted with norepinephrine; however, treatment with plasma collected from rats that received intravenous administration of [pyr1]-apelin-13 caused pronounced relaxation of isolated arteries. Incubation with the guanylyl cyclase inhibitor, ODQ, blocked NO-induced relaxation, but did not significantly alter the relaxation response to the plasma from apelin-treated rats. Taken together, these findings demonstrate that intravenous injection of apelin causes a significant depressor response that is mediated by a NO-independent mechanism involving an unidentified substance released into the bloodstream leading to vasodilation.

Hemoadhican, a Tissue Adhesion Hemostatic Material Independent of Blood Coagulation.

Uncontrolled hemorrhage is a leading cause of death, emphasizing the need for novel hemostatic agents. Here, a novel hemostatic polysaccharide hemoadhican (HD) is screened out by analyzing the rheological properties of screened material mixed blood sludges, which is prepared by mixing polysaccharide granules and whole blood to mimic the coagulation in vitro. HD is produced by a bacterial isolate Paenibacillus sp.1229, and the repeating units of HD are →)-α-L-Rhap-(1→3)-β-D-Glcp-(1→4)[4,6-ethylidene-α-D-Galp-(1→4)-α-D-Glcp-(1→3)]-α-D-Manp-(1→. Compared to chitosan and celox, HD achieves more effective hemostasis in animal models with mouse and rat femoral arteries, rat carotid arteries, and rabbit femoral arteries. Especially, HD maintains an excellent hemostatic capability in animals with heparin-induced hemorrhage diathesis. In vitro experiments show HD granules can quickly absorb a small amount of blood component to create a hemophobic blood sludge resistant to high pressure. The blood sludge firmly adheres to damaged tissue and efficiently repels blood. In vitro experiments show that HD does not actively trigger blood coagulation cascade and is independent of blood conditions including heparin treatment. In addition, HD moisturizes wounds and accelerates wound healing, exhibiting excellent biodegradability, and hemocompatibility. The results indicate that HD is a promising hemostatic material for treating traumatic hemorrhages and uncontrollable surgical bleeding.

Abstract 496: Inhibition Of Tirna-gly-gcc Ameliorates Neointimal Formation Via Cbx3-mediated Vascular Smooth Muscle Cells Phenotypic Switching

Introduction: Vascular smooth muscle cells (VSMCs) are the main component of blood vessels and synthetic VSMCs play an essential role in vascular diseases. tRNA-derived fragments (tRFs) are a new class of non-coding RNAs involved in a variety of pathological processes, but their biological functions and mechanisms in VSMCs phenotype transition and vascular intimal hyperplasia are unclear. Hypothesis: We assessed the hypothesis that tRFs play important role in VSMCs phenotype transition, regulation of tRFs could ameliorates neointimal formation. Methods: Differential expression profiles of tRFs from different phenotype of VSMCs was acquired using small-RNA sequence. The expression of tiRNA-Gly-GCC was confirmed in VSMCs, vascular tissues and plasma from healthy and atherosclerosis using quantitative real-time PCR and RNA fluorescence in situ hybridization. Gain-and loss- of function were performed using mimics and inhibitors to investigate the role of tiRNA-Gly-GCC in VSMCs phenotypic transition and neointimal formation after vascular injury. Dual-luciferase reporter gene and rescue experiments were performed to demonstrate the relationship between tiRNA-Gly-GCC and CBX3. Results: tiRNA-Gly-GCC is upregulated in synthetic VSMCs, atherosclerotic arteries, plasma and the balloon injured carotid artery of rats. Functionally, the inhibition of tiRNA-Gly-GCC represses VSMCs proliferation, migration, and reversed dedifferentiation, whereas the overexpression of tiRNA-Gly- GCC have contrary effects. Mechanistically, tiRNA-Gly-GCC performs these functions on VSMCs via downregulating the expression of CBX3. Finally, the inhibition of tiRNA-Gly-GCC could ameliorate neointimal formation after vascular injury in vivo . Conclusions: In conclusion, tiRNA-Gly-GCC is a mediator of VSMCs phenotypic switching by targeting CBX3, inhibition of tiRNA-Gly-GCC suppresses neointimal formation.

3D bioprinting microgels to construct implantable vascular tissue

Engineered implantable functional thick tissues require hierarchical vasculatures within cell-laden hydrogel that can mechanically withstand the shear stress from perfusion and facilitate angiogenesis for nutrient transfer. Yet current extrusion-based 3D printing strategies are unable to recapitulate hierarchical networks, highlighting the need for bioinks with tunable properties. Here, we introduce an approach whereby crosslinkable microgels enhance mechanical stability and induce spontaneous microvascular networks comprised of human umbilical cord vein endothelial cells (HUVECs) in a soft gelatin methacryoyl (GelMA)-based bioink. Furthermore, we successfully implanted the 3D printed multi-branched tissue, being connected from the rat carotid artery to the jugular vein direct surgical anastomosis. The work represents a significant step toward in the field of large vascularized tissue fabrication and may have implications for the treatment of organ failure in the future.

Nimodipine augments cerebrovascular reactivity in aging but runs the risk of local perfusion reduction in acute cerebral ischemia.

The efficacy of cerebrovascular reactivity (CVR) is taken as an indicator of cerebrovascular health. We found that CVR tested with the inhalation of 10 % CO2 declined in the parietal cortex of 18-20-month-old rats. The CVR deficit in old rats was coincident with cerebrovascular smooth muscle cell and astrocyte senescence, revealed by the immuno-labeling of the cellular senescence marker p16 in these cells. In a next series of experiments, CVR was severely impaired in the acute phase of incomplete global forebrain ischemia produced by the bilateral occlusion of the common carotid arteries in young adult rats. In acute ischemia, CVR impairment often manifested as a perfusion drop rather than blood flow elevation in response to hypercapnia. Next, nimodipine, an L-type voltage-gated calcium channel antagonist was administered topically to rescue CVR in both aging, and cerebra ischemia. Nimodipine augmented CVR in the aged brain, but worsened CVR impairment in acute cerebral ischemia. A careful evaluation of benefits and side effects of nimodipine is recommended, especially in acute ischemic stroke.

Cellular microarrays for assessing single-cell phenotypic changes in vascular cell populations

Microengineering technologies provide bespoke tools for single-cell studies, including microarray approaches. There are many challenges when culturing adherent single cells in confined geometries for extended periods, including the ability of migratory cells to overcome confining cell-repellent surfaces with time. Following studies suggesting clonal expansion of only a few vascular smooth muscle cells (vSMCs) contributes to plaque formation, the investigation of vSMCs at the single-cell level is central to furthering our understanding of atherosclerosis. Herein, we present a medium throughput cellular microarray, for the tracking of single, freshly-isolated vSMCs as they undergo phenotypic modulation in vitro. Our solution facilitates long-term cell confinement (> 3 weeks) utilising novel application of surface functionalisation methods to define individual culture microwells. We demonstrate successful tracking of hundreds of native vSMCs isolated from rat aortic and carotid artery tissue, monitoring their proliferative capacity and uptake of oxidised low-density lipoprotein (oxLDL) by live-cell microscopy. After 7 days in vitro, the majority of viable SMCs remained as single non-proliferating cells (51% aorta, 78% carotid). However, a sub-population of vSMCs demonstrated high proliferative capacity (≥ 10 progeny; 18% aorta, 5% carotid), in line with reports that a limited number of medial SMCs selectively expand to populate atherosclerotic lesions. Furthermore, we show that, when exposed to oxLDL, proliferative cells uptake higher levels of lipoproteins, whilst also expressing greater levels of galectin-3. Our microwell array approach enables long-term characterisation of multiple phenotypic characteristics and the identification of new cellular sub-populations in migratory, proliferative adherent cell types.Graphical abstract

MiR579-3p is an inhibitory modulator of neointimal hyperplasia and transcription factors c-MYB and KLF4

Neointimal hyperplasia (IH) is a common vascular pathology that typically manifests in in-stent restenosis and bypass vein graft failure. Smooth muscle cell (SMC) phenotypic switching is central to IH, both regulated by some microRNAs, yet the role of miR579-3p, a scarcely studied microRNA, is not known. Unbiased bioinformatic analysis suggested that miR579-3p was repressed in human primary SMCs treated with different pro-IH cytokines. Moreover, miR579-3p was software-predicted to target both c-MYB and KLF4 − two master transcription factors known to promote SMC phenotypic switching. Interestingly, treating injured rat carotid arteries via local infusion of miR579-3p-expressing lentivirus reduced IH 14 days after injury. In cultured human SMCs, transfection with miR579-3p inhibited SMC phenotypic switching, as indicated by decreased proliferation/migration and increased SMC contractile proteins. miR579-3p transfection downregulated c-MYB and KLF4, and luciferase assays indicated miR579-3p’s targeting of the 3′UTRs of the c-MYB and KLF4 mRNAs. In vivo, immunohistochemistry showed that treatment of injured rat arteries with the miR579-3p lentivirus reduced c-MYB and KLF4 and increased SMC contractile proteins. Thus, this study identifies miR579-3p as a previously unrecognized small-RNA inhibitor of IH and SMC phenotypic switch involving its targeting of c-MYB and KLF4. Further studies on miR579-3p may provide an opportunity for translation to develop IH-mitigating new therapeutics.

Gene-repressing epigenetic reader EED unexpectedly enhances cyclinD1 gene activation

Epigenetically switched, proliferative vascular smooth muscle cells (SMCs) form neointima, engendering stenotic diseases. Histone-3 lysine-27 trimethylation (H3K27me3) and acetylation (H3K27ac) marks are associated with gene repression and activation, respectively. The polycomb protein embryonic ectoderm development (EED) reads H3K27me3 and also enhances its deposition, hence is a canonical gene repressor. However, herein we found an unexpected role for EED in activating the bona fide pro-proliferative gene Ccnd1 (cyclinD1). EED overexpression in SMCs increased Ccnd1 mRNA, seemingly contradicting its gene-repressing function. However, consistently, EED co-immunoprecipitated with gene-activating H3K27ac reader BRD4, and they co-occupied at both mitogen-activated Ccnd1 and mitogen-repressed P57 (bona fide anti-proliferative gene), as indicated by chromatin immunoprecipitation qPCR. These results were abolished by an inhibitor of either the EED/H3K27me3 or BRD4/H3K27ac reader function. In accordance, elevating BRD4 increased H3K27me3. Invivo, while EED was upregulated in rat and human neointimal lesions, selective EED inhibition abated angioplasty-induced neointima and reduced cyclinD1 in rat carotid arteries. Thus, results uncover a previously unknown role for EED in Ccnd1 activation, likely via its cooperativity with BRD4 that enhances each other's reader function; i.e., activating pro-proliferative Ccnd1 while repressing anti-proliferative P57. As such, this study confers mechanistic implications for the epigenetic intervention of neointimal pathology.

Conserved miR-370-3p/BMP-7 axis regulates the phenotypic change of human vascular smooth muscle cells

Endothelial dysfunction and inflammatory immune response trigger dedifferentiation of vascular smooth muscle cells (SMCs) from contractile to synthetic phenotype and initiate arterial occlusion. However, the complex vascular remodeling process playing roles in arterial occlusion initiation is largely unknown. We performed bulk sequencing of small and messenger RNAs in a rodent arterial injury model. Bioinformatic data analyses reveal that six miRNAs are overexpressed in injured rat carotids as well as synthetic-type human vascular SMCs. In vitro cell-based assays show that four miRNAs (miR-130b-5p, miR-132-3p, miR-370-3p, and miR-410-3p) distinctly regulate the proliferation of and monocyte adhesion to the vascular SMCs. Individual inhibition of the four selected miRNAs strongly prevents the neointimal hyperplasia in the injured rat carotid arteries. Mechanistically, miR-132-3p and miR-370-3p direct the cell cycle progression, triggering SMC proliferation. Gene ontology analysis of mRNA sequencing data consistently reveal that the miRNA targets include gene clusters that direct proliferation, differentiation, and inflammation. Notably, bone morphogenic protein (BMP)-7 is a prominent target gene of miR-370-3p, and it regulates vascular SMC proliferation in cellular and animal models. Overall, this study first reports that the miR-370-3p/BMP-7 axis determines the vascular SMC phenotype in both rodent and human systems.

Inhibition of tiRNA-Gly-GCC ameliorates neointimal formation via CBX3-mediated VSMCs phenotypic switching.

tRNA-derived fragments (tRFs) are a new class of non-coding RNAs involved in a variety of pathological processes, but their biological functions and mechanisms in human aortic smooth muscle cells (HASMCs) phenotype transition and vascular intimal hyperplasia are unclear. tiRNA-Gly-GCC is upregulated in synthetic HASMCs, atherosclerotic arteries, plasma, and the balloon injured carotid artery of rats. Functionally, the inhibition of tiRNA-Gly-GCC represses HASMCs proliferation, migration, and reversed dedifferentiation, whereas the overexpression of tiRNA- Gly-GCC have contrary effects. Mechanistically, tiRNA-Gly-GCC performs these functions on HASMCs via downregulating chromobox protein homolog 3 (CBX3). Finally, the inhibition of tiRNA-Gly-GCC could ameliorate neointimal formation after vascular injury in vivo. tiRNA-Gly-GCC is a mediator of HASMCs phenotypic switching by targeting CBX3 and inhibition of tiRNA-Gly-GCC suppresses neointimal formation.

Embolic occlusion of internal carotid artery in conscious rats: Immediate effects of cerebral ischemia.

In most preclinical models of focal ischemic stroke, vascular occlusion is performed under general anesthesia. However, anesthetic agents exert confounding effects on mean arterial blood pressure (MABP), cerebrovascular tone, oxygen demand, and neurotransmitter receptor transduction. Moreover, the majority of studies do not use a blood clot, which more fully models embolic stroke. Here, we developed a blood clot injection model to produce large cerebral artery ischemia in unanesthetized rats. Under isoflurane anesthesia, an indwelling catheter was implanted in the internal carotid artery via a common carotid arteriotomy and preloaded with a 0.38-mm-diameter clot of 1.5, 3, or 6cm length. After discontinuing anesthesia, the rat was returned to a home cage where it regained normal mobility, grooming, eating activity, and a stable recovery of MABP. One hour later, the clot was injected over a 10-s period and the rats were observed for 24 h. Clot injection produced a brief period of irritability, then 15-20 min of complete inactivity, followed by lethargic activity at 20-40 min, ipsilateral deviation of the head and neck at 1-2h, and limb weakness and circling at 2-4h. Neurologic deficits, elevated MABP, infarct volume, and increased hemisphere water content varied directly with clot size. Mortality after 6-cm clot injection (53%) was greater than that after 1.5-cm (10%) or 3-cm (20%) injection. Combined non-survivor groups had the greatest MABP, infarct volume, and water content. Among all groups, the pressor response correlated with infarct volume. The coefficient of variation of infarct volume with the 3-cm clot was less than that in published studies with the filament or standard clot models, and therefore may provide stronger statistical power for stroke translational studies. The more severe outcomes from the 6-cm clot model may be useful for the study of malignant stroke.

Cyclic stretch promotes vascular homing of endothelial progenitor cells via Acsl1 regulation of mitochondrial fatty acid oxidation

Endothelial progenitor cells (EPCs) play an important role in vascular repair and re-endothelialization after vessel injury. EPCs in blood vessels are subjected to cyclic stretch (CS) due to the pulsatile pressure, but the role of CS in metabolic reprogramming of EPC, particularly its vascular homing and repair, is largely unknown. In the current study, physiological CS applied to EPCs at a magnitude of 10% and a frequency of 1 Hz significantly promoted their vascular adhesion and endothelial differentiation. CS enhanced mitochondrial elongation and oxidative phosphorylation (OXPHOS), as well as adenosine triphosphateproduction. Metabolomic study and Ultra-high performance liquid chromatography-mass spectrometry assay revealed that CS significantly decreased the content of long-chain fatty acids (LCFAs) and markedly induced long-chain fatty acyl-CoA synthetase 1 (Acsl1), which in turn facilitated the catabolism of LCFAs in mitochondria via fatty acid β-oxidation and OXPHOS. In a rat carotid artery injury model, transplantation of EPCs overexpressing Acsl1 enhanced the adhesion and re-endothelialization of EPCs invivo. MRI and vascular morphology staining showed that Acsl1 overexpression in EPCs improved vascular repair and inhibited vascular stenosis. This study reveals a mechanotransduction mechanism by which physiological CS enhances endothelial repair via EPC patency.

Ioversol Induced Microglia Proinflammatory Activation and Oxidative Stress in Rats.

Contrast-induced encephalopathy (CIE) following angiography, though not often and reversible, can in some cases lead to permanent neurological dysfunction. To identify how neuroinflammation is involved in CIE, we investigated microglia responses to a bolus injection of ioversol in the internal carotid artery (ICA) in rats. MicroCT scanning indicated that the injected ioversol was cleared from the rat's brain within 25 min. However, proinflammatory activated and significantly increased microglia were found in the rat occipital cortex at 1 day, and the number of blood vessel-associated microglia was still significantly higher at 3-day post-injection, compared with sham- and PBS-treated rats. Moreover, significantly upregulated malondialdehyde (MDA), downregulated superoxide dismutase (SOD) levels, and elevated proinflammatory cytokines were observed in the brain of rats treated with ioversol. Ioversol administration decreased cell viability of primarily cultured microglia and induced significant proinflammatory activation. Furthermore, ioversol remarkably upregulated astrocytic aquaporin (AQP) 4 expression in the rats brain, and transwell cultures showed significantly enhanced microglia migrating to ioversol-treated endothelial cells. Immediate injection of edaravone dexborneol, a novel antioxidative drug, after ioversol injection effectively rescued ioversol-induced neuroinflammation. Together, these findings suggest that ioversol induced neuroinflammation and oxidative stress in the brain via microglia activation in a direct and indirect manner, which might contribute to the pathogenesis of CIE.

SMOC2 promoted vascular smooth muscle cell proliferation, migration, and extracellular matrix degradation by activating BMP/TGF-β1 signaling pathway.

A widespread degenerative condition of the aorta, abdominal aortic aneurysm (AAA), severely endangers the health of middle-aged and elderly people. SPARC related modular calcium binding2 (SMOC2) is upregulated in the carotid arteries of rats with atherosclerotic lesions, but its function in AAA is still unknown. Therefore, the aim of this research was to evaluate the function of SMOC2 in AAA. The results showed that in the AAA tissues, SMOC2 expression was upregulated compared with healthy controls. Overexpression of SMOC2 promoted vascular smooth muscle cells (VSMCs) proliferation, migration, and extracellular matrix (ECM) degradation. In contrast, silence of SMOC2 inhibited VSMCs proliferation, migration, and ECM degradation. Overexpression of SMOC2 promoted BMP and TGF-β1 expression and silence of SMOC2 had an opposite effect. Besides, inhibition of BMP or TGF-β1 suppressed VSMCs cell proliferation, migration, and ECM degradation. Moreover, inhibition BMP or TGF-β1 reversed the promotive effects of SMOC2 overexpression on VSMCs proliferation, migration, and ECM degradation. SMOC2 may affecte the formation of AAA by upregulating BMP and TGF-β1 to regulate the proliferation, migration, and ECM degradation of VSMCs.

Vascular contraction in response to protein kinase C activator was induced via protein kinase Cβ in rat carotid artery

Vascular contraction in response to protein kinase C activator was induced via protein kinase Cβ in rat carotid artery

Effect of piper Crocatum leaves extract on atherosclerosis in diabetic rats

Atherosclerosis is caused by an inflammatory process in the endothelium due to an imbalance between oxidant and antioxidant agents that often occurs in Diabetes mellitus (DM) patients. Antioxidants that function to neutralize superoxide can be used to prevent atherosclerosis in DM. Piper crocatum leaves shows an unknown antioxidant effect on the atherosclerosis process.The aim of this study is to determine the effect Piper crocatum leaves extract on blood MDA levels and the severity of atherosclerosis in diabetic rats. 30 Sprague Dawley rats were randomly divided into 6 groups, namely, HC (nondiabetic), NC (diabetic-no therapy), PC (metformin 45 mg/kg), PC200, PC300, PC400 (Piper crocatum leaves extract 200/300/ 400 mg/kg/day). Termination, blood sampling, and histopathological analysis were performed after 14 days of treatment. MDA was measured using the TBARS method, and read on a 532 nm wavelength UV-vis spectrophotometer. The severity of atherosclerosis of the rat carotid artery was observed from tissue stained with Haematoxylin Eosin staining at 400x microscope magnification. The mean blood MDA levels in the PC200, PC300, PC400 groups were 1.24 ± 0.26, 0.85 ± 0.35, 0.10 and ± 0.02, respectively, and a decrease in MDA levels was found in the PC200, PC300, and PC400 compared to group NC. The study showed a decrease in the severity of atherosclerosis in groups PC200, PC300, PC400 compared to groups NC. Piper crocatum leaves extract had an effect on decreasing MDA levels and severity of atherosclerosis in diabetic rats.

MiR-7-5p attenuates vascular smooth muscle cell migration and intimal hyperplasia after vascular injury by NF-kB signaling

BackgroundAtherosclerosis (AS) is the primary cause of coronary artery disease, which is featured by aberrant proliferation, differentiation, and migration of vascular smooth muscle cells (VSMCs). MicroRNAs play crucial roles in AS, but the function of miR-7-5p in AS remains unclear. Here, we aimed to explore the effect of miR-7-5p on AS and VSMCs in vitro and in vivo. MethodsThe in vivo rat AS model and apoE−/− mouse model were established. The carotid artery injury was checked by immunohistochemistry staining. The RNA levels of miR-7-5p and p65 were measured by qPCR assay. Protein levels were checked by western blotting. Cell apoptosis was evaluated by flow cytometry. Cell migration was checked by Transwell assay and wound healing assay. The potential interaction between miR-7-5p with p65 was checked by luciferase reporter gene assay. ResultsMiR-7-5p was downregulated and NF-κB p65 was upregulated in injured carotid arteries in rat model. The carotid artery injury in the AS rats and the treatment of miR-7-5p attenuated the phenotype in the model. Immunohistochemistry staining and Western blot analysis revealed that PCNA levels were increased in injured carotid arteries of the model rats and miR-7-5p could reverse the levels. The cell viability of VSMCs was induced by PDGF-BB but miR-7-5p blocked the phenotype. PDGF-BB decreased apoptosis of VSMCs, while miR-7-5p was able to restore the cell apoptosis in the model. PDGF-BB-induced migration of VSMCs was attenuated by miR-7-5p. miR-7-5p mimic remarkably repressed the luciferase activity of p65 in VSMCs. The levels of p65 were inhibited by miR-7-5p in the cells. The PDGF-BB-promoted cell viability and migration of VSMCs was repressed by miR-7-5p and p65 overexpression reversed the phenotype. ConclusionWe concluded that miR-7-5p attenuates vascular smooth muscle cell migration and intimal hyperplasia after vascular injury by NF-kB signaling.

Abstract 11944: Surfactant Protein a Promotes Smooth Muscle Cell Phenotype Modulation Through Inhibiting the Myocardin-Smad3 Interaction

Vascular smooth muscle cell (SMC) transition from a differentiated to dedifferentiated phenotype and subsequent neointima formation/vascular remodeling plays a critical role in the development of a number of vascular diseases such as atherosclerosis, restenosis after angioplasty or bypass, diabetic vascular complications, arteriopathy transplants, asthma and cancer. However, mechanisms that regulate SMC phenotype modulation and neointima formation are not completely understood. We have found that Surfactant protein A (SPA), an innate immune system collectin that reduces membrane surface tension and protects lung function during exhalation, is critical for SMC phenotype and vascular modeling. SPA is induced during SMC phenotypic modulation and injury-induced vascular remodeling in both rat and mouse carotid arteries. Knockdown of SPA increased contractile protein expression while enhancing the expression of Myocardin and TGF-β1 in SMCs. Moreover, SMCs from SPA knockout mice had increased Smad3 phosphorylation which was blocked by TGF-β1 neutralizing antibody. To understand the contribution of SMC SPA to vascular remodeling, we generated SMC specific SPA-deficient (SPAsm -/- ) mice with hypercholesteremia by injection of AAV-PCSK9. By using mouse carotid artery wire-injury model, we found that SPA deficiency in SMCs markedly inhibits neointimal formation and the Myocardin-Smad3 interaction in the injured artery. Our data demonstrated that SPA mediates proliferative/synthetic phenotype and neointimal hyperplasia by blocking Myocardin-Smad3 interaction.

Comparison of the immunohistochemical and ultrastructural studies of the white rats sensorimotor cortex synaptic terminals reaction to common carotid arteries ligation

The aim of the research was to study the structural and functional changes in axonal terminals in layers I, III, and V of the sensorimotor cortex (SMC) of the brain of Wistar rats after the common carotid artery (CCA) bilateral ligation using immunohistochemical and apparatus-microscopic methods. Material and methods. Incomplete cerebral ischemia was modeled by bilateral ligation of the common carotid arteries (CCA - 2-vessel model of global ischemia without hypotension) in white Wistar rats (n=36). SMC was studied in the control (intact rats, n=6), 1, 3, 7, 14 and 30 days (n=30) after POCA. Nissl, hematoxylin-eosin, immunohistochemical reactions for p38, and electron microscopy were used. The total number density and relative area of axonal terminals were determined. Statistical hypotheses were tested using nonparametric methods for pairwise and multiple comparisons using the Statistica 8.0 program. Results. After CCA bilateral ligation, the content of degeneratively altered neurons in the rat brain SMC increased. Changes in the SMC neurons were accompanied by neuropil hyperhydration and reactive astrogliosis. The total number density of terminals in all SMC layers decreased statistically significantly after 1 day (by 28.6% in layer I, 46.9% in layer III, and 46.4% in layer V) and remained approximately at this level throughout the entire observation period. . The relative area of synaptic terminals differed in the compared SMC layers. In layers I and III of the SMC, the values of this indicator first (days 1 and 3) decreased, and then (days 7, 14, and 30) they increased. In layer V of the SMC, activation of the expression of this protein occurred already in the acute period (days 1 and 3), decreased after 7 and 14 days, and increased again after 30 days. Ultrastructural examination revealed more small terminal axonal branches. However, the general trend of changes in the number of terminals was similar. Conclusion. After CCA bilateral ligation, destructive and compensatory-restorative changes in axonal terminals were revealed in layers I, III, and V of the rat MMC. The reorganization of interneuronal relationships occurred against the background of pronounced manifestations of neuropil hyperhydration. The maximum destruction of synaptic terminals was noted in layer III of the SMC, and their adaptive changes were observed in layer V. The results of immunohistochemical and ultrastructural studies are comparable and complement each other. All this can probably be considered as a structural basis for changes in the integrative-starting activity of the brain after CCA bilateral ligation.

Perivascular application of sirolimus multilayer nanofibrous mat for prevention of vascular stenosis: Preparation, In vitro characterization, and In vivo efficacy evaluation

Graft stenosis, occurring after coronary artery bypass surgery (CABG), diminishes the efficacy and long-term patency of vascular interventions. Multilayer nanofibers (NFs) are developed to provide localized controlled release of sirolimus to prevent vascular stenosis, as well as limit drug exposure to other organs. NFs are composed of a mid-layer of drug and polycaprolactone (PCL), a bioadhesive layer of PCL and collagen, and a backing layer of PCL. NFs are characterized in vitro regarding morphology, mechanical strength, contact angle, water uptake, drug content, and drug release behavior. The average fiber diameter is around 300–500 nm. Sirolimus entrapment is confirmed by drug content, FTIR, and XRD. It is found that sirolimus is released from multilayer NFs in a sustained manner with about half of the payload released over one week. Sirolimus multilayer NFs are implanted in the rat carotid artery after inducing vascular injury. Histological, immunohistochemical (α-SMA, Ki-67, and CD31), and in vivo imaging analyses reveal that the administration of sirolimus multilayer NFs causes significant inhibition of intimal hyperplasia in the rat carotid injury model compared to the control groups and drug suspension. The obtained results reveal that the sirolimus multilayer nanosystem could be a promising carrier for local vascular drug delivery.