Assessment of central nervous system vasculitis in children based on high-resolution vascular wall imaging.

Objectives: Central nervous system vasculitis (CNSV) is a rare disease. High-resolution vessel wall imaging (HR-VWI) enables the identification of inflammatory changes within the vessel wall. Few studies have applied HR-VWI to assess CNSV in children. This study delves into the utility of HR-VWI for diagnosing and treating CNSV in children, with the aim of enhancing clinical diagnosis and efficacy evaluation. Methods: Imaging data were acquired from children who underwent HR-VWI examinations. The study meticulously analysed clinical data and laboratory tests to discern the characteristics and distribution patterns of diverse vasculitis forms. Results: In children, CNSV mainly involves medium vessels with grade 1 and 2 stenosis (grade 4 stenosis is rare), and the imaging features generally show centripetal and moderate enhancement, suggesting that this feature is specific for the diagnosis of CNSV. High-grade stenosis, concentric enhancement and strong enhancement of the vasculature indicate more severe disease activity. Remarkably, HR-VWI proved to be significantly more sensitive than magnetic resonance angiography in detecting CNSV. Among the 13 cases subjected to imaging review, 8 demonstrated a reduction or resolution of vessel wall inflammation. In contrast, five patients exhibited worsening inflammation in the vessel wall. HR-VWI demonstrated that changes in vessel wall inflammation were closely correlated with changes in brain parenchymal lesions and symptoms. Conclusion: This study underscores the diagnostic value of HR-VWI in CNSV assessment and treatment monitoring, offering a quantitative evaluation of CNSV in children.

Inhibiting the ROCK Pathway Ameliorates Acute Lung Injury in Mice following Myocardial Ischemia/reperfusion.

To clarify the role of Y-27632, a selective inhibitor of Rho-associated coiled-coil forming protein kinase (ROCK), in acute lung injury (ALI) induced by myocardial ischemia/reperfusion (I/R). Mice were randomized into Sham, I/R, and Y-27632 (10, 20 or 30 mg/kg) + I/R groups, and hemodynamics, infarcted area, the protein concentration, neutrophils in bronchoalveolar lavage fluid (BALF), malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) levels were assessed. Pathological changes were evaluated by hematoxylin-eosin (HE) staining; protein and gene expression were measured by Western blotting, enzyme-linked immunosorbent assay (ELISA), immunohistochemistry and quantitative real-time reverse-transcription polymerase chain reaction (qRT-PCR); and apoptosis was assessed by terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end labeling (TUNEL) staining. ROCK1 and ROCK2 expression was up-regulated in lung tissues of I/R mice compared to sham mice. Y-27632 decreased the protein concentration and the neutrophils in BALF in I/R mice, improved hemodynamics and reduced infarct size (IS)/area at risk (AAR) ratio. In addition, pathological changes in lung tissues of Y-27632-treated mice were mitigated, and these alterations were accompanied by decreases in MDA levels in lung tissues and increases in SOD and GSH-Px levels. Moreover, in I/R group, the number of apoptotic cells in lung tissue was higher than that in sham group, and p53, Caspase-3 and Bax expression was up-regulated; however, following treatment with Y-27632 (10, 20 and 30 mg/kg), these changes were reversed. Inhibition of ROCK pathway by Y-27632 ameliorated ALI in myocardial I/R mice by mitigating oxidative stress, inflammation and cell apoptosis.

MiR-518a-5p Targets GZMB to Extenuate Vascular Endothelial Cell Injury Induced by Hypoxia-Reoxygenation and Thereby Improves Myocardial Ischemia.

To probe the function of miR-518a-5p/Granzyme B (GZMB) in hypoxia/reoxygenation (H/R) -induced vascular endothelial cell injury.The key genes of myocardial infarction were screened by bioinformatic methods. The upstream micro RNAs (miRNAs) of GZMB were predicted by TargetScan. The binding of miR-518a-5p to GZMB was verified with luciferase reporter assay. The H/R model was constructed with human vascular endothelial cell (HUVEC) in vitro. Cell Counting Kit-8 (CCK8) assay was performed to detect cell proliferation. Western blot was utilized to evaluate the levels of indicated proteins.GZMB was up-regulated in patients with myocardial infarction and identified as the key gene by the bioinformatics analysis. Then the prediction from TargetScan indicated that miR-518a-5p, which is down-regulated in myocardial infarction patients, might be the potential upstream miRNA for GZMB. The following experiments verified that miR-518a-5p could bind to the 3'UTR of GZMB and negatively modulates GZMB expression. More importantly, the miR-518a-5p mimic enhanced cell proliferation and repressed apoptosis of H/R-injured HUVEC cells by inhibiting GZMB expression.We proved that miR-518a-5p could partly attenuate H/R-induced HUVEC cell injury by targeting GZMB, and perhaps the miR-518a-5p/GZMB axis could be potential therapeutic targets for myocardial infarction.

Molecular and Cellular Effect of Angiotensin 1-7 on Hypertensive Kidney Disease.

BACKGROUND: Studies implicate that angiotensin 1-7 (Ang1-7) imparts protective effects in the kidney. However, its relevance in hypertensive kidney disease is not fully understood. The purpose of this study was to explore the role of Ang1-7 on renal damage/remodeling during hypertension and its potential underlying molecular-cellular mechanisms. METHODS: Hypertension was induced in adult Sprague-Dawley rats by infusion of aldosterone (ALDO; 0.75 µg/hour) for 4 weeks with or without co-treatment of Ang1-7 (1 mg/kg/day). Untreated rats served as controls. Systolic blood pressure was monitored by tail-cuff technique. Renal fibrosis was evaluated by picrosirius red staining and renal collagen volume fraction was quantitated using imaging analyzing system. The expression of profibrotic factors [transforming growth factor-ß1 (TGF-ß1), platelet-derived growth factor-D (PDGF-D), fibroblast growth factor-1 (FGF-1), vascular endothelial growth factor-D (VEGF-D), and tissue inhibitors of metalloproteinases (TIMPs)] and free radical producing enzymes (inducible nitric oxide synthase and nicotinamide adenine dinucleotide phosphate [NADPH] oxidase) in the kidney were examined by reverse transcription-polymerase chain reaction and western blot. Renal oxidative stress was assessed by malondialdehyde (MDA) measurement. RESULTS: Chronic ALDO infusion caused hypertension and hypertensive renal disease represented as glomerular damage/sclerosis. Ang1-7 co-treatment did not affect blood pressure in ALDO-treated rats, but significantly attenuated the glomerular damage/fibrosis. ALDO treatment significantly elevated renal expression of profibrogenic factors, including TGF-ß1, TIMP-1/TIMP-2, FGF-1, PDGF-D, and VEGF-D, whereas Ang1-7 co-treatment significantly reduced renal TGF-ß1, TIMP-1/TIMP-2, and FGF-1, but not PDGF-D and VEGF-D. Furthermore, ALDO infusion elevated NADPH oxidase (gp91phox) and MDA in the kidney, which was attenuated by Ang1-7 co-treatment. CONCLUSIONS: Ang1-7 plays a protective role in the hypertensive kidney disease independent of blood pressure. The beneficial effects of Ang1-7 are likely mediated via suppressing TGF-ß/FGF-1 pathways and oxidative stress.

TLR4/NF-κB signaling pathway regulates inflammatory response involved in pathophysiological mechanisms of type A aortic dissection / 中国胸心血管外科临床杂志

@#Objective     To investigate activated toll-like receptor-4 (TLR4) signaling pathway involved in pathophysiological mechanisms of type A aortic dissection (TAAD). Methods     Specimens of full-thickness ascending aorta wall from the TAAD patients (n=12) and the controlled donors (n=12) were collected. Western blotting was used to examine the associated proteins' expression of TLR4 signaling pathway. Blood samples from TAAD (n=43) and controlled patients (n=50) were examined by enzyme-linked immunosorbent assay (ELISA) to detect the circulating plasma cytokines levels of interleukin-1β (L-1β). Results     In the aortic wall of TAAD, expression levels of TLR4 and protein expression of major molecule significantly elevated, and activated macrophages increased. Furthermore, elevated IL-1β levels were observed in the TAAD patients’ plasma compared with the control plasma. Multiple logistic regression analysis and receiver operating characteristic (ROC) curve showed that elevated IL-1β could be a novel and promising biomarker with important diagnostic and predictive value in the identification of TAAD. Conclusion     Activated TLR4/NF-κB signaling pathway regulates inflammatory response to involve in pathophysiological mechanisms of type A aortic dissection and its regulated inflammatory products have important predictive value for patients with TAAD.

Long non-coding RNA CCRR controls cardiac conduction via regulating intercellular coupling.

Long non-coding RNAs (lncRNAs) have emerged as a new class of gene expression regulators playing key roles in many biological and pathophysiological processes. Here, we identify cardiac conduction regulatory RNA (CCRR) as an antiarrhythmic lncRNA. CCRR is downregulated in a mouse model of heart failure (HF) and in patients with HF, and this downregulation slows cardiac conduction and enhances arrhythmogenicity. Moreover, CCRR silencing induces arrhythmias in healthy mice. CCRR overexpression eliminates these detrimental alterations. HF or CCRR knockdown causes destruction of intercalated discs and gap junctions to slow longitudinal cardiac conduction. CCRR overexpression improves cardiac conduction by blocking endocytic trafficking of connexin43 (Cx43) to prevent its degradation via binding to Cx43-interacting protein CIP85, whereas CCRR silence does the opposite. We identified the functional domain of CCRR, which can reproduce the functional roles and pertinent molecular events of full-length CCRR. Our study suggests CCRR replacement a potential therapeutic approach for pathological arrhythmias.

Ozone protects the rat lung from ischemia-reperfusion injury by attenuating NLRP3-mediated inflammation, enhancing Nrf2 antioxidant activity and inhibiting apoptosis.

Ischemia-reperfusion injury (IRI) is a major cause of lung dysfunction during cardiovascular surgery, heart transplantation and cardiopulmonary bypass procedures, and the inflammatory response, oxidative stress, and apoptosis play key and allegedly maladaptive roles in its pathogenesis. The aim of this study was to initially elucidate whether ozone induces oxidative preconditioning by activating nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and secondly to determine whether ozone oxidative preconditioning (OzoneOP) protects the lung from IRI by attenuating nucleotide-binding oligomerization domain-like receptor containing pyrin domain 3 (NLRP3)-mediated inflammation, enhancing the antioxidant activity of Nrf2 and inhibiting apoptosis. Rats treated with or without OzoneOP (2 ml containing 100 µg/kg/day) were subjected to 1 h of lung ischemia followed by 2 h of reperfusion for 10 days. Lung damage, antioxidant capacity, inflammation and apoptosis were evaluated and compared among different groups after reperfusion. OzoneOP significantly ameliorated changes in lung morphology and protected the lung from IRI by attenuating oxidative stress, inflammation-induced injury and lung apoptosis. Moreover, OzoneOP increased the expression of Nrf2 and decreased the levels of NLRP3, apoptosis-associated speck-like protein containing a caspase activation and recruitment domain (ASC), un-cleavable cysteine-requiring aspartate protease-1 (procaspase-1), cysteine-requiring aspartate protease-1 (caspase-1) and interleukin-1ß (IL-1ß) in the rat lungs. In summary, these results provide new insights into the molecular events modulated by ozone and suggest that ozone therapy may be an integrative support for patients with lung IRI.

The effect of ozone on hypoxia, hemolysis and morphological change of blood from patients with aortic dissection (AD): a preliminary in vitro experiment of ozonated autohemotherapy for treating AD.

This study aimed to investigate the effect of ozone on hypoxia, hemolysis and morphological change of blood from aortic dissection (AD) patients for providing preliminary evidence of application of ozonated autohemotherapy (Ozone-AHT) in AD patients. 20 AD patients and 20 healthy volunteers were consecutively included, and blood samples were collected from all participants and ozonized in vitro. PO2, SO2, malondialdehyde (MDA), superoxide dismutase (SOD), malformation percentage, morphology change and spatial distribution of filamentous actin (F-actin) in erythrocytes at different ozone concentrations were evaluated. After ozonation of whole blood, the median levels of PO2 and SO2 increased under Ozone concentrations at 40 µg/mL, 80 µg/mL and 160 µg/mL compared with samples exposed to 0 µg/mL in both AD group and control group. The MDA level was similar in samples exposed to 0 µg/mL, 40 µg/mL and 80 µg/mL ozone, while the levels of SOD increased in samples exposed to 40 µg/mL and 80 µg/mL in both AD group and control group. Compared with the samples exposed to 0 µg/mL ozone, FHb level only increased in samples exposed to 80 µg/mL and 160 µg/mL Ozone in both AD group and control group. In addition, overdosed ozone (160 µg/mL) but not therapeutic ozone concentrations (0 µg/mL, 40 µg/mL and 80 µg/mL) increased malformation percentage and morphology change of erythrocytes in both AD group and control group. In conclusion, Ozone improves oxygen content and reduces oxidative damage in blood from AD patients, and therapeutic dose ozone do not induce hemolysis and morphology change of erythrocytes.

Ultrastructural changes in red blood cells in aortic dissection patients under extracorporeal circulation: Atomic force microscopy study.

PURPOSE: During extracorporeal circulation in heart surgery, blood is exposed to non-physiological conditions, such as high shear stress, foreign surfaces, turbulence, and hypothermia. These factors cause damage to the red blood cells, which is manifested by immediate and delayed hemolysis or some changes in the mechanical properties of red blood cells, defined as sublethal trauma. Unfortunately, sublethal trauma is hard to detect, and there is not enough morphological evidence regarding red blood cell sublethal trauma. In this study, red blood cell sublethal trauma was observed after extracorporeal circulation by describing ultrastructural changes in red blood cell membranes using atomic force microscopy and scanning electron microscopy. METHODS: Venous blood (2 mL) was collected into heparin tubes from preoperative, intraoperative and postoperative aortic dissection patients for comparison with blood from healthy patients. The red blood cell morphological study (malformations percentage, diameter, height, concavity, and roughness) was performed with scanning electron microscopy and atomic force microscopy. RESULTS: Scanning electron microscopy and atomic force microscopy imaging analysis revealed that the red blood cell shape changed during extracorporeal circulation and that the red blood cell malformation percentage in the postoperative group was higher than those in the preoperative and intraoperative groups. Most morphological parameters had no obvious changes, except roughness (Ra and Rq) in aortic dissection patients. Atomic force microscopy quantitative analysis indicated that the roughness of red blood cell membranes increased during extracorporeal circulation. CONCLUSIONS: This study demonstrates that ultrastructural morphological damage occurs to red blood cells membranes due to extracorporeal circulation in aortic dissection patients. In addition, we provided a new parameter (Ra and Rq) to evaluate red blood cell sublethal trauma.

Expression of platelet-derived growth factor B is upregulated in patients with thoracic aortic dissection.

OBJECTIVE: Thoracic aortic dissection (TAD) is a serious condition requiring urgent treatment to avoid catastrophic consequences. The inflammatory response is involved in the occurrence and development of TAD, possibly potentiated by platelet-derived growth factors (PDGFs). This study aimed to determine whether expression of PDGF-B (a subunit of PDGF-BB) was increased in TAD patients and to explore the factors responsible for its upregulation and subsequent effects on TAD. METHODS: Full-thickness ascending aorta wall specimens from TAD patients (n = 15) and control patients (n = 10) were examined for expression of PDGF-B and its receptor (PDGFRB) and in terms of morphology, inflammation, and fibrosis. Blood samples from TAD and control patients were collected to detect plasma levels of PDGF-BB and soluble elastins. RESULTS: Expression levels of PDGF-B, PDGFRB, and collagen I were significantly enhanced in ascending aorta wall specimens from TAD patients compared with controls. Furthermore, soluble elastic fragments and PDGF-BB were significantly increased in plasma from TAD patients compared with controls, and numerous irregular elastic fibers and macrophages were seen in the ascending aorta wall in TAD patients. CONCLUSIONS: An increase in elastic fragments in the aorta wall might be responsible for inducing the activation and migration of macrophages to injured sites, leading to elevated expression of PDGF-B, which in turn induces deposition of collagen, disrupts extracellular matrix homeostasis, and increases the stiffness of the aorta wall, resulting in compromised aorta compliance.

Ozone protects rat heart against ischemia-reperfusion injury: A role for oxidative preconditioning in attenuating mitochondrial injury.

Ischemia-reperfusion injury (IRI) is a major cause of cardiac dysfunction during cardiovascular surgery, heart transplantation and cardiopulmonary bypass procedures. The purpose of the present study was to explore, firstly, whether ozone induces oxidative preconditioning by activation of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and, secondly, whether ozone oxidative preconditioning (OzoneOP) can protect the heart against IRI by attenuating mitochondrial damage. Rats were subjected to 30min of cardiac ischemia followed by 2h of reperfusion, with or without prior OzoneOP (100µg/kg/day) for 5 days. Antioxidant capacity, myocardial apoptosis and mitochondrial damage were evaluated and compared at the end of reperfusion. OzoneOP was found to increase antioxidant capacity and to protect the myocardium against IRI by attenuating mitochondrial damage and myocardial apoptosis. The study suggests a potential role for OzoneOP in protecting the heart against IRI during cardiovascular surgery, cardiopulmonary bypass procedures or transplantation.

Vascular endothelial growth factor-D mediates fibrogenic response in myofibroblasts.

Vascular endothelial growth factor (VEGF)-D is a crucial mediator of angiogenesis. Following myocardial infarction (MI), cardiac VEGF-D and VEGF receptor (VEGFR)-3 are significantly upregulated. In addition to endothelial cells, myofibroblasts at the site of MI highly express VEGFR-3, implicating the involvement of VEGF-D in cardiac fibrogenesis that promotes repair and remodeling. The aim of the current study was to further explore the critical role of VEGF-D in fibrogenic response in myofibroblasts. Myofibroblast proliferation, migration, collagen synthesis, and degradation were investigated in cultured cardiac myofibroblasts subjected to VEGF-D with/without VEGFR antagonist or ERK inhibitor. Vehicle-treated cells served as controls. Myofibroblast proliferation and migration were detected by BrdU assay and Boyden Chamber method, respectively. Expression of type I collagen, metalloproteinase (MMP)-2/-9, tissue inhibitor of MMP (TIMP)-1/-2, and ERK phosphorylation were evaluated by Western blot analyses. Our results revealed that compared to controls, (1) VEGF-D significantly increased myofibroblast proliferation and migration; (2) VEGF-D significantly upregulated type I collagen synthesis in a dose- and time-dependent manner; (3) VEGFR antagonist abolished VEGF-D-induced myofibroblast proliferation and type I collagen release; (4) VEGF-D stimulated MMP-2/-9 and TIMP-1/-2 synthesis; (5) VEGF-D activated ERK phosphorylation; and (6) ERK inhibitor abolished VEGF-D-induced myofibroblast proliferation and type I collagen synthesis. Our in vitro studies have demonstrated that VEGF-D serves as a crucial profibrogenic mediator by stimulating myofibroblast growth, migration and collagen synthesis. Further studies are underway to determine the role of VEGF-D in fibrous tissue formation during cardiac repair following MI.

VEGF-C/VEGFR-3 pathway promotes myocyte hypertrophy and survival in the infarcted myocardium.

BACKGROUND: Numerous studies have shown that in addition to angio/lymphangiogenesis, the VEGF family is involved in other cellular actions. We have recently reported that enhanced VEGF-C and VEGFR-3 in the infarcted rat myocardium, suggesting the paracrine/autocrine function of VEGF-C on cardiac remodeling. The current study was designed to test the hypothesis that VEGF-C regulates cardiomyocyte growth and survival in the infarcted myocardium. METHODS AND RESULTS: Gene profiling and VEGFR-3 expression of cardiomyocytes were assessed by laser capture microdissection/microarray and immunohistochemistry in the normal and infarcted myocardium. The effect of VEGF-C on myocyte hypertrophy and apoptosis during normoxia and hypoxia was detected by RT-PCR and western blotting in cultured rat neonatal cardiomyocytes. VEGFR-3 was minimally expressed in cardiomyocytes of the normal and noninfarcted myocardium, while markedly elevated in the surviving cardiomyocytes of the infarcted myocardium and border zone. Genes altered in the surviving cardiomyocytes were associated with the networks regulating cellular growth and survival. VEGF-C significantly increased the expression of atrial natriuretic factor (ANP), brain natriuretic factor (BNP), and ß-myosin heavy chain (MHC), markers of hypertrophy, in neonatal cardiomyocytes. Hypoxia caused neonatal cardiomyocyte atrophy, which was prevented by VEGF-C treatment. Hypoxia significantly enhanced apoptotic mediators, including cleaved caspase 3, 8, and 9, and Bax in neonatal cardiomyocytes, which were abolished by VEGF-C treatment. CONCLUSION: Our findings indicate that VEGF-C/VEGFR-3 pathway exerts a beneficial role in the infarcted myocardium by promoting compensatory cardiomyocyte hypertrophy and survival.

Platelet-derived growth factor blockade on cardiac remodeling following infarction.

Cardiac repair and remodeling occur following myocardial infarction (MI). Our previous study demonstrated that platelet-derived growth factor (PDGF)-A/-D and PDGF receptors (PDGFR) are increased in the infarcted heart, with cells expressing PDGFR primarily endothelial and fibroblast-like cells. In the present study, we tested the hypothesis that PDGF contributes to cardiac angiogenesis and fibrogenesis post-MI. Rats with experimental MI were treated with either a PDGFR antagonist (Imatinib, 40 mg/kg/day) or vehicle by gavage, and sham-operated rats served as the controls. Cardiac fibrogenesis, angiogenesis, and ventricular function were detected at weeks 1 and 4 post-MI. We found that (1) transforming growth factor (TGF)-ß1, tissue inhibitors of metalloproteinases (TIMP)-1/-2, and type I collagen mRNA were all significantly increased in the infarcted heart at week 1 post-MI, while PDGFR blockade significantly reduced these fibrogenic mediators in the noninfarcted myocardium as compared to controls; (2) fibrosis developed in both the infarcted and noninfarcted myocardium at week 4 with PDGFR blockade significantly suppressing collagen volume in the noninfarcted myocardium; (3) angiogenesis was activated in the infarcted myocardium, particularly at week 1, and was not altered by treatment with imatinib; and (4) ventricular dysfunction was evident in MI rats at week 4, and mildly improved with imatinib treatment. These observations indicated that PDGF can contribute to the development of cardiac interstitial fibrosis in the noninfarcted myocardium, but does not alter scar formation in the infarcted myocardium. Further, this study suggests the potential therapeutic effects of PDGFR blockade on interstitial fibrosis of the infarcted heart.

Vascular endothelial growth factor-C: its unrevealed role in fibrogenesis.

Vascular endothelial growth factor (VEGF)-C is a key mediator of lymphangiogenesis. Our recent study shows that VEGF-C/VEGF receptors (VEGFR)-3 are significantly increased in the infarcted rat myocardium, where VEGFR-3 is expressed not only in lymph ducts but also in myofibroblasts, indicating that VEGF-C has an unrevealed role in fibrogenesis during cardiac repair. The current study is to explore the regulation and molecular mechanisms of VEGF-C in fibrogenesis. The potential regulation of VEGF-C on myofibroblast differentiation/growth/migration, collagen degradation/synthesis, and transforming growth factor (TGF)-ß and ERK pathways was detected in cultured cardiac myofibroblasts. Our results showed that VEGF-C significantly increased myofibroblast proliferation, migration, and type I/III collagen production. Matrix metalloproteinase (MMP)-2 and -9 were significantly elevated in the medium of VEGF-C-treated cells, coincident with increased tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2. Furthermore, VEGF-C activated the TGF-ß1 pathway and ERK phosphorylation, which was significantly suppressed by TGF-ß or ERK blockade. This is the first study indicating that in addition to lymphangiogenesis, VEGF-C is also involved in fibrogenesis through stimulation of myofibroblast proliferation, migration, and collagen synthesis, via activation of the TGF-ß1 and ERK pathways.

Autocrine and paracrine function of Angiotensin 1-7 in tissue repair during hypertension.

BACKGROUND: Angiotensin-converting enzyme 2 (ACE2) cleaves angiotensin (Ang) II to generate Ang1-7, which mediates cellular actions through Mas receptors (MasR). Hypertension is accompanied by high or low circulating AngII levels and cardiac/renal injury. The purpose of this study is to explore (i) whether circulating AngII affects ACE2/MasR expressions in the hypertensive heart and kidney; and (ii) whether Ang1-7 regulates cardiac repair/remodeling responses through MasR during hypertension. METHODS: In the first portion of the study, rats received either an AngII infusion (400ng/kg/min) for 4 weeks, leading to hypertension with high circulating AngII, or an aldosterone (ALDO, 0.75 µg/h) infusion for 4 weeks, leading to hypertension with low/normal circulating AngII. Cardiac and renal ACE2/MasR expressions were examined. We found that cardiac ACE2 was increased and MasR attenuated in both AngII and ALDO groups. However, renal ACE2 and MasR remained unchanged in both AngII- and ALDO-treated animals. RESULTS: In the second portion, rats received AngII infusion with/without MasR antagonist (A779, 1mg/kg/day) for 4 weeks. The roles of MasR blockade in cardiac inflammation, fibrosis, apoptosis, and ventricular function were examined. Chronic AngII infusion caused scattered cardiac injuries, and A779 cotreatment exacerbated cardiac injury, resulting in aggravated inflammatory, fibrogenic, and apoptotic responses compared with the AngII group. Cardiac function, however, was unaltered in the AngII and A779 groups. CONCLUSIONS: ACE2 and MasR expressions in the hypertensive heart and kidney are not regulated by circulating AngII levels. Ang1-7 is involved in multiple repair responses, suggesting that therapeutic strategies aimed at administering Ang1-7 hold potential for the management of cardiac remodeling.

Platelet-derived growth factor-D promotes fibrogenesis of cardiac fibroblasts.

Platelet-derived growth factor (PDGF)-D is a newly recognized member of the PDGF family with its role just now being understood. Our previous study shows that PDGF-D and its receptors (PDGFR-ß) are significantly increased in the infarcted heart, where PDGFR-ß is primarily expressed by fibroblasts, indicating the involvement of PDGF-D in the development of cardiac fibrosis. In continuing with these findings, the current study explored the molecular basis of PDGF-D on fibrogenesis. Rat cardiac fibroblasts were isolated and treated with PDGF-D (200 ng/ml medium). The potential regulation of PDGF-D on fibroblast growth, phenotype change, collagen turnover, and the transforming growth factor (TGF)-ß pathway were explored. We found: 1) PDGF-D significantly elevated cardiac fibroblast proliferation, myofibroblast (myoFb) differentiation, and type I collagen secretion; 2) matrix metalloproteinase (MMP)-1, MMP-2, and MMP-9 protein levels were significantly elevated in PDGF-D-treated cells, which were coincident with increased expressions of tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2; 3) PDGF-D significantly enhanced TGF-ß1 synthesis, which was eliminated by TGF-ß blockade with small-interfering RNA (siRNA); 4) the stimulatory role of PDGF-D on fibroblast proliferation and collagen synthesis was abolished by TGF-ß blockade; and 5) TGF-ß siRNA treatment significantly suppressed PDGF-D synthesis in fibroblasts. These observations indicate that PDGF-D promotes fibrogenesis through multiple mechanisms. Coelevations of TIMPs and MMPs counterbalance collagen degradation. The profibrogenic role of PDGF-D is mediated through activation of the TGF-ß1 pathway. TGF-ß1 exerts positive feedback on PDGF-D synthesis. These findings suggest the potential therapeutic effect of PDGFR blockade on interstitial fibrosis in the infarcted heart.

Andrographolide inhibits intimal hyperplasia in a rat model of autogenous vein grafts.

The saphenous vein is considered a common conduit for coronary artery bypass grafting. A major limitation involved is the high graft occlusion rate. We evaluated the effect and mechanism of andrographolide on intimal hyperplasia (IH) of autografted rat veins. For this purpose, 140 female Sprague-Dawley rats were randomly divided into experimental (andro) and control groups. Andro rats received andrographolide (200 mg/kg) lavaged once daily for 2 days before surgery while controls received normal saline. The external jugular vein was grafted into the ipsilateral carotid artery. The animals were killed at 1/3 days and 1/2/4/6/8 weeks postoperatively. The neointima to media area (I/M) ratio was determined. Expression of the p65, E-selectin and MMP-9 proteins/mRNA was also determined. Autografted rat veins displayed IH postoperatively. In andro rats, compared with controls, IH was significantly reduced (P < 0.01) at 2/4/6/8 weeks but not at 1/3/7 days postoperatively. Andrographolide also significantly (P < 0.05) reduced the expression of E-selectin and MMP-9 proteins/mRNAs at 2/4/6/8 weeks postoperatively whereas p65 protein/mRNA was significantly (P < 0.05) diminished at 1/3 days and 1/2/4/6/8 weeks postoperatively as compared with controls. Therefore, it was concluded that andrographolide inhibited IH in autografted rat veins through the suppression of p65, E-selectin, and MMP-9 at the transcriptional level.

[Studies on a new type structure OELD with interinserting interface].

A new type organic electroluminescent device with interinserting interface was fabricated. The basic structure of the device is ITO/NPB/Alq3/Al. By tailor-made template, the two interinserting interfaces were fabricated with NPB/Alq3 and Alq3/Al, respectively. The charge distribution on the interface and the electric field distribution in the organic layer were changed by introducing interinserting interfaces, thus the electron injection was improved, and the balance of the number of the electrons and holes at the interface was obtained. Therefore, the formation probability of exciton was enhanced and the leakage current was reduced. Compared to the traditional two-layer structure devices, the interinserting structure device has lower turn-on voltage and higher luminous efficiency. The driving-voltage of the interinserting structure OELD decreased while the brightness increased with the increase in the number of the interinsertion. As the current density increased, all the devices with interinserting interface showed high optical-electrical stability. The turn-on voltage of the device e is 3 V, and was made using the three slots template. At the current density of 54 mA x cm(-2), the device e gets its maximum efficiency, which is 34% higher than the traditional structure device a.