NDRG1 Signaling Is Essential for Endothelial Inflammation and Vascular Remodeling.

BACKGROUND: NDRG-1 (N-myc downstream-regulated gene 1) is a member of NDRG family that plays essential roles in cell differentiation, proliferation, and stress responses. Although the expression of NDRG1 is regulated by fluid shear stress, its roles in vascular biology remain poorly understood. The purpose of the study is to determine the functional significance of NDRG1 in vascular inflammation and remodeling. METHODS AND RESULTS: By using quantitative polymerase chain reaction, western blot, and immunohistochemistry, we demonstrate that the expression of NDRG1 is markedly increased in cytokine-stimulated endothelial cells and in human and mouse atherosclerotic lesions. To determine the role of NDRG1 in endothelial activation, we performed loss-of-function studies using NDRG1 short hairpin RNA. Our results demonstrate that NDRG1 knockdown by lentivirus bearing NDRG1 short hairpin RNA substantially attenuates both IL-1ß (interleukin-1ß) and TNF-α (tumor necrosis factor-α)-induced expression of cytokines/chemokines and adhesion molecules. Intriguingly, inhibition of NDRG1 also significantly attenuates the expression of procoagulant molecules, such as PAI-1 (plasminogen activator inhibitor type 1) and TF (tissue factor), and increases the expression of TM (thrombomodulin) and t-PA (tissue-type plasminogen activator), thus exerting potent antithrombotic effects in endothelial cells. Mechanistically, we showed that NDRG1 interacts with orphan Nur77 (nuclear receptor) and functionally inhibits the transcriptional activity of Nur77 and NF-κB (nuclear factor Kappa B) in endothelial cells. Moreover, in NDRG1 knockdown cells, both cytokine-induced mitogen-activated protein kinase activation, c-Jun phosphorylation, and AP-1 (activator protein 1) transcriptional activity are substantially inhibited. Neointima and atherosclerosis formation induced by carotid artery ligation and arterial thrombosis were markedly attenuated in endothelial cell-specific NDRG1 knockout mice compared with their wild-type littermates. CONCLUSIONS: Our results for the first time identify NDRG1 as a critical mediator implicated in regulating endothelial inflammation, thrombotic responses, and vascular remodeling, and suggest that inhibition of NDRG1 may represent a novel therapeutic strategy for inflammatory vascular diseases, such as atherothrombosis and restenosis.

Natural variation in OsSEC13 HOMOLOG 1 modulates redox homeostasis to confer cold tolerance in rice.

Rice (Oryza sativa L.) is a cold-sensitive species that often faces cold stress, which adversely affects yield productivity and quality. However, the genetic basis for low-temperature adaptation in rice remains unclear. Here, we demonstrate that 2 functional polymorphisms in O. sativa SEC13 Homolog 1 (OsSEH1), encoding a WD40-repeat nucleoporin, between the 2 subspecies O. sativa japonica and O. sativa indica rice, may have facilitated cold adaptation in japonica rice. We show that OsSEH1 of the japonica variety expressed in OsSEH1MSD plants (transgenic line overexpressing the OsSEH1 allele from Mangshuidao [MSD], cold-tolerant landrace) has a higher affinity for O. sativa metallothionein 2b (OsMT2b) than that of OsSEH1 of indica. This high affinity of OsSEH1MSD for OsMT2b results in inhibition of OsMT2b degradation, with decreased accumulation of reactive oxygen species and increased cold tolerance. Transcriptome analysis indicates that OsSEH1 positively regulates the expression of the genes encoding dehydration-responsive element-binding transcription factors, i.e. OsDREB1 genes, and induces the expression of multiple cold-regulated genes to enhance cold tolerance. Our findings highlight a breeding resource for improving cold tolerance in rice.

Niclosamide modulates phenotypic switch and inflammatory responses in human pulmonary arterial smooth muscle cells.

Excessive proliferation and migration of pulmonary arterial smooth muscle cells (PASMCs) represent key steps of pulmonary vascular remodeling, leading to the development of pulmonary arterial hypertension (PAH) and right ventricular failure. Niclosamide (NCL), an FDA-approved anthelmintic, has been shown to regulate cell proliferation, migration, invasion, and apoptosis through a variety of signaling pathways. However, its role on modulating the phenotypic switch and inflammatory responses in PASMCs remains unclear. In this study, cell proliferation assay showed that NCL inhibited PDGF-BB induced proliferation of human PASMCs in a dose-dependent manner. Western blot analysis further confirmed a notable reduction in the expression of cyclin D1 and PCNA proteins. Subsequently, flow cytometry analysis demonstrated that NCL induced an increased percentage of cells in the G1 phase while promoting apoptosis in PASMCs. Moreover, both scratch wound assay and transwell assay confirmed that NCL decreased PDGF-BB-induced migration of PASMCs. Mechanistically, western blot revealed that pretreatment of PASMCs with NCL markedly restored the protein levels of SMA, SM22, and calponin, while reducing phosphorylation of P38/STAT3 signaling in the presence of PDGF-BB. Interestingly, macrophages adhesion assay showed that NCL markedly reduced recruitment of Calcein-AM labeled RAW264.7 by TNFα-stimulated PASMCs. Western blot revealed that NCL suppressed TNFα-induced expression of both of VCAM-1 and ICAM-1 proteins. Furthermore, pretreatment of PASMCs with NCL significantly inhibited NLRP3 inflammasome activity through reducing NLRP3, AIM2, mature interleukin-1ß (IL-ß), and cleaved Caspase-1 proteins expression. Together, these results suggested versatile effects of NCL on controlling of proliferation, migration, and inflammatory responses in PASMCs through modulating different pathways, indicating that repurposing of NCL may emerge as a highly effective drug for PAH treatment.

Safety and efficacy of the second-generation cryoballoon for left atrial appendage electrical isolation in canines.

AIMS: Left atrial appendage electrical isolation (LAAEI) has demonstrated a significant enhancement in the success rate of atrial fibrillation (AF) ablation. Nevertheless, concerns persist about the safety of LAAEI, particularly regarding alterations in left atrial appendage (LAA) flow velocity and the potential risks of thrombus. This study aimed to assess the efficacy and safety of LAAEI, investigating changes in LAA flow velocity in canines. METHODS AND RESULTS: The study comprised a total of 10 canines. The LAAEI procedure used by a 23 mm cryoballoon of the second generation was conducted at least 180 s. Intracardiac ultrasonography (ICE) was employed to quantify the velocity flow of the LAA both prior to and following LAAEI. Following a 3-month period, subsequent evaluations were performed to assess the LAA velocity flow and the potential reconnection. Histopathological examination was conducted. Left atrial appendage electrical isolation was effectively accomplished in all canines, resulting in a 100% acute success rate (10/10). The flow velocity in the LAA showed a notable reduction during LAAEI as compared with the values before the ablation procedure (53.12 ± 5.89 vs. 42.01 ± 9.22 cm/s, P = 0.007). After the follow-up, reconnection was observed in four canines, leading to a success rate of LAAEI of 60% (6/10). The flow velocity in the LAA was consistently lower (53.12 ± 5.89 vs. 44.33 ± 10.49 cm/s, P = 0.006), and no blood clot development was observed. The histopathological study indicated that there was consistent and complete injury to the LAA, affecting all layers of its wall. The injured tissue was subsequently replaced by fibrous tissue. CONCLUSION: The feasibility of using cryoballoon ablation for LAAEI was confirmed in canines, leading to a significant reduction of LAA flow velocity after ablation. Some restoration of LAA flow velocity after ablation may be linked to the passive movement of the LAA and potential reconnecting. However, this conclusion is limited to animal study; more clinical data are needed to further illustrate the safety and accessibility of LAAEI in humans.

Downregulation of NUP93 aggravates hypoxia-induced death of cardiomyocytes in vitro through abnormal regulation of gene transcription.

Nuclear pore complex in the nuclear envelope plays an important role in controlling the transportation of RNAs, proteins and other macromolecules between the nucleus and cytoplasm. The relationship between abnormal expression of nucleoporins and cardiovascular diseases is unclear. In this study we investigated how myocardial infarction affected the expression and function of nucleoporins in cardiomyocytes. We separately knocked down 27 nucleoporins in rat primary myocardial cells. Among 27 nucleoporins, knockdown of Nup93, Nup210 and Nup214 markedly increased the expression of ANP and BNP, two molecular markers of cardiomyocyte function. We showed that Nup93 was significantly downregulated in hypoxic cardiomyocytes. Knockdown of Nup93 aggravated hypoxia-induced injury and cell death of cardiomyocytes, whereas overexpression of Nup93 led to the opposite effects. RNA-seq and bioinformatics analysis revealed that knockdown of Nup93 did not affect the overall transportation of mRNAs from the nucleus to the cytoplasm, but regulated the transcription of a large number of mRNAs in cardiomyocytes, which are mainly involved in oxidative phosphorylation and ribosome subunits. Most of the down-regulated genes by Nup93 knockdown overlapped with the genes whose promoters could be directly bound by Nup93. Among these genes, we demonstrated that Nup93 knockdown significantly down-regulated the expression of YAP1. Overexpression of YAP1 partially rescued the function of Nup93 knockdown and attenuated the effects of hypoxia on cell injury and cardiomyocyte death. We conclude that down-regulation of Nup93, at least partially, contributes to hypoxia-induced injury and cardiomyocyte death through abnormal interaction with the genome to dynamically regulate the transcription of YAP1 and other genes. These results reveal a new mechanism of Nup93 and might provide new therapeutic targets for the treatment of ischemia-induced heart failure.

Arabidopsis Endoplasmic Reticulum-Localized UBAC2 Proteins Interact with PAMP-INDUCED COILED-COIL to Regulate Pathogen-Induced Callose Deposition and Plant Immunity.

Pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) is initiated upon PAMP recognition by pattern recognition receptors (PRR). PTI signals are transmitted through activation of mitogen-activated protein kinases (MAPKs), inducing signaling and defense processes such as reactive oxygen species (ROS) production and callose deposition. Here, we examine mutants for two Arabidopsis thaliana genes encoding homologs of UBIQUITIN-ASSOCIATED DOMAIN-CONTAINING PROTEIN 2 (UBAC2), a conserved endoplasmic reticulum (ER) protein implicated in ER protein quality control. The ubac2 mutants were hypersusceptible to a type III secretion-deficient strain of the bacterial pathogen Pseudomonas syringae, indicating a PTI defect. The ubac2 mutants showed normal PRR biogenesis, MAPK activation, ROS burst, and PTI-associated gene expression. Pathogen- and PAMP-induced callose deposition, however, was compromised in ubac2 mutants. UBAC2 proteins interact with the plant-specific long coiled-coil protein PAMP-INDUCED COILED COIL (PICC), and picc mutants were compromised in callose deposition and PTI. Compromised callose deposition in the ubac2 and picc mutants was associated with reduced accumulation of the POWDERY MILDEW RESISTANT 4 (PMR4) callose synthase, which is responsible for pathogen-induced callose synthesis. Constitutive overexpression of PMR4 restored pathogen-induced callose synthesis and PTI in the ubac2 and picc mutants. These results uncover an ER pathway involving the conserved UBAC2 and plant-specific PICC proteins that specifically regulate pathogen-induced callose deposition in plant innate immunity.

Therapeutic overexpression of miR-92a-2-5p ameliorated cardiomyocyte oxidative stress injury in the development of diabetic cardiomyopathy.

BACKGROUND: Diabetic cardiomyopathy (DCM) results from pathological changes in cardiac structure and function caused by diabetes. Excessive oxidative stress is an important feature of DCM pathogenesis. MicroRNAs (miRNAs) are key regulators of oxidative stress in the cardiovascular system. In the present study, we screened for the expression of oxidative stress-responsive miRNAs in the development of DCM. Furthermore, we aimed to explore the mechanism and therapeutic potential of miR-92a-2-5p in preventing diabetes-induced myocardial damage. METHODS: An experimental type 2 diabetic (T2DM) rat model was induced using a high-fat diet and low-dose streptozotocin (30 mg/kg). Oxidative stress injury in cardiomyocytes was induced by high glucose (33 mmol/L). Oxidative stress-responsive miRNAs were screened by quantitative real-time PCR. Intervention with miR-92a-2-5p was accomplished by tail vein injection of agomiR in vivo or adenovirus transfection in vitro. RESULTS: The expression of miR-92a-2-5p in the heart tissues was significantly decreased in the T2DM group. Decreased miR-92a-2-5p expression was also detected in high glucose-stimulated cardiomyocytes. Overexpression of miR-92a-2-5p attenuated cardiomyocyte oxidative stress injury, as demonstrated by increased glutathione level, and reduced reactive oxygen species accumulation, malondialdehyde and apoptosis levels. MAPK interacting serine/threonine kinase 2 (MKNK2) was verified as a novel target of miR-92a-2-5p. Overexpression of miR-92a-2-5p in cardiomyocytes significantly inhibited MKNK2 expression, leading to decreased phosphorylation of p38-MAPK signaling, which, in turn, ameliorated cardiomyocyte oxidative stress injury. Additionally, diabetes-induced myocardial damage was significantly alleviated by the injection of miR-92a-2-5p agomiR, which manifested as a significant improvement in myocardial remodeling and function. CONCLUSIONS: miR-92a-2-5p plays an important role in cardiac oxidative stress, and may serve as a therapeutic target in DCM.

Isolation and characterization of wheat ice recrystallisation inhibition gene promoter involved in low temperature and methyl jasmonate responses.

It is well known that plant growth, development, survival and geographical distribution are constrained by extreme climatic conditions, especially extreme low temperature. Under cold stress, cold-inducible promoters were identified as important molecular switches to transcriptionally regulate the initiation of genes associated with cold acclimation processes and enhance the adaptability of plants to cold stimulation. Wheat (Triticum aestivum L.) is one of the most dominating food crops in the world, and wheat crops are generally overwintering with strong cold resistance. Our previous study already proved that heterologous expression of wheat ice recrystallization inhibition (IRI) genes enhanced freezing tolerance in tobacco. However, the upstream regulatory mechanisms of TaIRI are ambiguous. In this study, the space-time specific expression of TaIRI genes in wheat was analyzed by quantitative real-time PCR (qRT-PCR), and results showed that the expression of TaIRI in all tissues was cold-induced and accelerate by exogenous methyl jasmonate (MeJA). Three promoters of TaIRI genes were isolated from wheat genome, and various 5'-deletion fragments of TaIRIp were integrated into ß-glucuronidase (GUS) within vector pCAMBIA1301. The promoter activity of TaIRI genes was determined through transient expression system of tobacco and stable expression of Arabidopsis thaliana. Results revealed that the GUS activity were significantly strengthened by cold and MeJA treatments. This study will provide insights into elucidating the transcription-regulatory mechanism of IRI proteins responding to low temperature.

MicroRNA-663 prevents monocrotaline-induced pulmonary arterial hypertension by targeting TGF-ß1/smad2/3 signaling.

OBJECTIVE: Pulmonary vascular remodeling due to excessive growth factor production and pulmonary artery smooth muscle cells (PASMCs) proliferation is the hallmark feature of pulmonary arterial hypertension (PAH). Recent studies suggest that miR-663 is a potent modulator for tumorigenesis and atherosclerosis. However, whether miR-663 involves in pulmonary vascular remodeling is still unclear. METHODS AND RESULTS: By using quantitative RT-PCR, we found that miR-663 was highly expressed in normal human PASMCs. In contrast, circulating level of miR-663 dramatically reduced in PAH patients. In addition, in situ hybridization showed that expression of miR-663 was decreased in pulmonary vasculature of PAH patients. Furthermore, MTT and cell scratch-wound assay showed that transfection of miR-663 mimics significantly inhibited platelet derived growth factor (PDGF)-induced PASMCs proliferation and migration, while knockdown of miR-663 expression enhanced these effects. Mechanistically, dual-luciferase reporter assay revealed that miR-663 directly targets the 3'UTR of TGF-ß1. Moreover, western blots and ELISA results showed that miR-663 decreased PDGF-induced TGF-ß1 expression and secretion, which in turn suppressed the downstream smad2/3 phosphorylation and collagen I expression. Finally, intratracheal instillation of adeno-miR-663 efficiently inhibited the development of pulmonary vascular remodeling and right ventricular hypertrophy in monocrotaline (MCT)-induced PAH rat models. CONCLUSION: These results indicate that miR-663 is a potential biomarker for PAH. MiR-663 decreases PDGF-BB-induced PASMCs proliferation and prevents pulmonary vascular remodeling and right ventricular hypertrophy in MCT-PAH by targeting TGF-ß1/smad2/3 signaling. These findings suggest that miR-663 may represent as an attractive approach for the diagnosis and treatment for PAH.

Portable Device Improves the Detection of Atrial Fibrillation After Ablation.

Asymptomatic recurrences of atrial fibrillation (AF) have been found to be common after ablation.A randomized controlled trial of AF screening using a handheld single-lead ECG monitor (BigThumb®) or a traditional follow-up strategy was conducted in patients with non-valvular AF after catheter ablation. Consecutive patients were randomized to either BigThumb Group (BT Group) or Traditional Follow-up Group (TF Group). The ECGs collected via BigThumb were compared using the automated AF detection algorithm, artificial intelligence (AI) algorithm, and cardiologists' manual review. Subsequent changes in adherence to oral anticoagulation of patients were also recorded. In this study, we examined 218 patients (109 in each group). After a follow-up of 345.4 ± 60.2 days, AF-free survival rate was 64.2% in BT Group and 78.9% in TF Group (P = 0.0163), with more adherence to oral anticoagulation in BT Group (P = 0.0052). The participants in the BT Group recorded 26133 ECGs, among which 3299 (12.6%) were diagnosed as AF by cardiologists' manual review. The sensitivity and specificity of the AI algorithm were 94.4% and 98.5% respectively, which are significantly higher than the automated AF detection algorithm (90.7% and 96.2%).As per our findings, it was determined that follow-up after AF ablation using BigThumb leads to a more frequent detection of AF recurrence and more adherence to oral anticoagulation. AI algorithm improves the accuracy of ECG diagnosis and has the potential to reduce the manual review.

Characterization of ZmCOLD1, novel GPCR-Type G Protein genes involved in cold stress from Zea mays L. and the evolution analysis with those from other species.

Maize is one of the most vital staple crops worldwide. G proteins modulate plentiful signaling pathways, and G protein-coupled receptor-type G proteins (GPCRs) are highly conserved membrane proteins in plants. However, researches on maize G proteins and GPCRs are scarce. In this study, we identified three novel GPCR-Type G Protein (GTG) genes from chromosome 10 (Chr 10) in maize, designated as ZmCOLD1-10A, ZmCOLD1-10B and ZmCOLD1-10C. Their amino acid sequences had high similarity to TaCOLD1 from wheat and OsCOLD1 from rice. They contained the basic characteristics of GTG/COLD1 proteins, including GPCR-like topology, the conserved hydrophilic loop (HL) domain, DUF3735 (domain of unknown function 3735) domain, GTPase-activating domain, and ATP/GTP-binding domain. Subcellular localization analyses of ZmCOLD1 proteins suggested that ZmCOLD1 proteins localized on plasma membrane (PM) and endoplasmic reticulum (ER). Furthermore, amino acid sequence alignment verified the conservation of the key 187th amino acid T in maize and other wild maize-relative species. Evolutionary relationship among plants GTG/COLD1 proteins family displayed strong group-specificity. Expression analysis indicated that ZmCOLD1-10A was cold-induced and inhibited by light. Together, these results suggested that ZmCOLD1 genes had potential value to improve cold tolerance and to contribute crops growth and molecular breeding.

Defensive functions of volatile organic compounds and essential oils from northern white-cedar in China.

BACKGROUND: Plants are known to emit diverse volatile organic compounds (VOCs), which may function as signaling substances in plant communication with other organisms. Thuja occidentalis, which is widely cultivated throughout China, releases aromatic VOCs into the air in winter and early spring. The relationship of this cultivated plant with its neighboring plants is necessary for the conservation of biodiversity. RESULTS: (-)-α-thujone (60.34 ± 5.58%) was found to be the major component in VOCs from the Shenyang population. The essential oils (EOs) from the Kunming and Shenyang populations included the major components (-)-α-thujone, fenchone, (+)-ß-thujone, and (+)-hibaene, identified using GC-MS analyses. (-)-α-thujone and (+)-hibaene were purified and identified by NMR identification. EOs and (-)-α-thujone exhibited valuable phytotoxic activities against seed germination and seedling growth of the plants Taraxacum mongolicum and Arabidopsis thaliana. Moreover, the EOs displayed potent inhibitory activity against pathogenic fungi of maize, including Fusarium graminearum, Curvularia lunata, and Bipolaris maydis, as well as one human fungal pathogen, Candida albicans. Quantitative analyses revealed high concentrations of (-)-α-thujone in the leaves of T. occidentalis individuals from both the Shenyang and Kunming populations. However, (-)-α-thujone (0.18 ± 0.17 µg/g) was only detected in the rhizosphere soil to a distance of 0.5 m from the plant. CONCLUSIONS: Taken together, our results suggest that the phytotoxic effects and antifungal activities of the EOs and (-)-α-thujone in T. occidentalis certainly increased the adaptability of this plant to the environment. Nevertheless, low concentrations of released (-)-α-thujone indicated that reasonable distance of T. occidentalis with other plant species will impair the effects of allelochemical of T. occidentalis.

Transcriptional up-regulation of relaxin-3 by Nur77 attenuates ß-adrenergic agonist-induced apoptosis in cardiomyocytes.

The relaxin family peptides have been shown to exert several beneficial effects on the heart, including anti-apoptosis, anti-fibrosis, and anti-hypertrophy activity. Understanding their regulation might provide new opportunities for therapeutic interventions, but the molecular mechanism(s) coordinating relaxin expression in the heart remain largely obscured. Previous work demonstrated a role for the orphan nuclear receptor Nur77 in regulating cardiomyocyte apoptosis. We therefore investigated Nur77 in the hopes of identifying novel relaxin regulators. Quantitative real-time PCR (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA) data indicated that ectopic expression of orphan nuclear receptor Nur77 markedly increased the expression of latexin-3 (RLN3), but not relaxin-1 (RLN1), in neonatal rat ventricular cardiomyocytes (NRVMs). Furthermore, we found that the ß-adrenergic agonist isoproterenol (ISO) markedly stimulated RLN3 expression, and this stimulation was significantly attenuated in Nur77 knockdown cardiomyocytes and Nur77 knockout hearts. We showed that Nur77 significantly increased RLN3 promoter activity via specific binding to the RLN3 promoter, as demonstrated by electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP) assays. Furthermore, we found that Nur77 overexpression potently inhibited ISO-induced cardiomyocyte apoptosis, whereas this protective effect was significantly attenuated in RLN3 knockdown cardiomyocytes, suggesting that Nur77-induced RLN3 expression is an important mediator for the suppression of cardiomyocyte apoptosis. These findings show that Nur77 regulates RLN3 expression, therefore suppressing apoptosis in the heart, and suggest that activation of Nur77 may represent a useful therapeutic strategy for inhibition of cardiac fibrosis and heart failure.

Long noncoding RNA MALAT1 mediates cardiac fibrosis in experimental postinfarct myocardium mice model.

Cardiac fibrosis is a pathological remodeling response to myocardial infarction (MI) and impairs cardiac contractility. Long noncoding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is increased in patients with MI. However, the functions of MALAT1 in cardiac fibrosis have not been elucidated. This study elucidates the roles of MALAT1 in MI and the underlying mechanisms. The MI model was established by artificial coronary artery occlusion in mice. Western blot analysis and quantitative reverse transcription-polymerase chain reaction were performed to analyze protein expression and RNA expression, respectively. Cardiac function was measured by echocardiography. Masson's trichrome staining was used to exhibit the fibrotic area in MI hearts. Cardiac fibroblasts were isolated from newborn pups, and cell proliferation was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Upregulation of MALAT1 and downregulation of microRNA-145 (miR-145) were induced in MI heart and angiotensin II (AngII)-treated cardiac fibroblasts, and the inhibition of miR-145 expression was reversed by MALAT1 depletion. Knockdown MALAT1 ameliorated MI-impaired cardiac function and prevented AngII-induced fibroblast proliferation, collagen production, and α-SMA expression in cardiac fibroblasts. MALAT1 stability and transforming growth factor-ß1 (TGF-ß1) activity were regulated by miR-145. AngII-induced TGF-ß1 activity in cardiac fibroblasts was blocked by MALAT1 knockdown. Based on these results, we concluded that lncRNA MALAT1 promotes cardiac fibrosis and deteriorates cardiac function post-MI by regulating TGF-ß1 activity via miR-145.

Nur77 limits endothelial barrier disruption to LPS in the mouse lung.

Nur77 is an orphan nuclear receptor implicated in the regulation of a wide range of biological processes, including the maintenance of systemic blood vessel homeostasis. Although Nur77 is known to be expressed in the lung, its role in regulating pulmonary vascular functions remains entirely unknown. In this study, we found that Nur77 is expressed at high levels in the lung, and its expression is markedly upregulated in response to LPS administration. While the pulmonary vasculature of mice that lacked Nur77 appeared to function normally under homeostatic conditions, we observed a dramatic decrease in its barrier functions after exposure to LPS, as demonstrated by an increase in serum proteins in the bronchoalveolar lavage fluid and a reduction in the expression of endothelial junctional proteins, such as vascular endothelial cadherin (VE-cadherin) and ß-catenin. Similarly, we found that siRNA knockdown of Nur77 in lung microvascular endothelial cells also reduced VE-cadherin and ß-catenin expression and increased the quantity of fluorescein isothiocyanate-labeled dextran transporting across LPS-injured endothelial monolayers. Consistent with Nur77 playing a vascular protective role, we found that adenoviral-mediated overexpression of Nur77 both enhanced expression of VE-cadherin and ß-catenin and augmented endothelial barrier protection to LPS in cultured cells. Mechanistically, Nur77 appeared to mediate its protective effects, at least in part, by binding to ß-catenin and preventing its degradation. Our findings demonstrate a key role for Nur77 in the maintenance of lung endothelial barrier protection to LPS and suggest that therapeutic strategies aimed at augmenting Nur77 levels might be effective in treating a wide variety of inflammatory vascular diseases of the lung.

Pim-1 Kinase Phosphorylates Cardiac Troponin I and Regulates Cardiac Myofilament Function.

BACKGROUND/AIMS: Pim-1 is a serine/threonine kinase that is highly expressed in the heart, and exerts potent cardiac protective effects through enhancing survival, proliferation, and regeneration of cardiomyocytes. Its myocardial specific substrates, however, remain unknown. In the present study, we aim to investigate whether Pim-1 modulates myofilament activity through phosphorylation of cardiac troponin I (cTnI), a key component in regulating myofilament function in the heart. METHODS: Coimmunoprecipitation and immunofluorescent assays were employed to investigate the interaction of Pim-1 with cTnI in cardiomyocytes. Biochemical, site directed mutagenesis, and mass spectrometric analyses were utilized to identify the phosphorylation sites of Pim1 in cTnI. Myofilament functional assay using skinned cardiac fiber was used to assess the effect of Pim1-mediated phosphorylation on cardiac myofilament activity. Lastly, the functional significance of Pim1-mediated cTnI in heart disease was determined in diabetic mice. RESULTS: We found that Pim-1 specifically interacts with cTnI in cardiomyocytes and this interaction leads to Pim1-mediated cTnI phosphorylation, predominantly at Ser23/24 and Ser150. Furthermore, our functional assay demonstrated that Pim-1 induces a robust phosphorylation of cTnI within the troponin complex, thus leading to a decreased Ca2+ sensitivity. Insulin-like growth factor 1 (IGF-1), a peptide growth factor that has been shown to stimulate myocardial contractility, markedly induces cTnI phosphorylation at Ser23/24 and Ser150 through increasing Pim-1 expression in cardiomyocytes. In a high-fat diabetic mice model, the expression of Pim1 in the heart is significantly decreased, which is accompanied by a decreased phosphorylation of cTnI at Ser23/24 and Ser150, further implicating the pathological significance of the Pim1/cTnI axis in the development of diabetic cardiomyopathy. CONCLUSION: Our results demonstrate that Pim-1 is a novel kinase that phosphorylates cTnI primarily at Ser23/24 and Ser150 in cardiomyocytes, which in turn may modulate myofilament function under a variety of physiological and pathophysiological conditions.

Identification of genes from the ICE-CBF-COR pathway under cold stress in Aegilops-Triticum composite group and the evolution analysis with those from Triticeae.

Adverse environmental conditions limit various aspects of plant growth, productivity, and ecological distribution. To get more insights into the signaling pathways under low temperature, we identified 10 C-repeat binding factors (CBFs), 9 inducer of CBF expression (ICEs) and 10 cold-responsive (CORs) genes from Aegilops-Triticum composite group under cold stress. Conserved amino acids analysis revealed that all CBF, ICE, COR contained specific and typical functional domains. Phylogenetic analysis of CBF proteins from Triticeae showed that these CBF homologs were divided into 11 groups. CBFs from Triticum were found in every group, which shows that these CBFs generated prior to the divergence of the subfamilies of Triticeae. The evolutionary relationship among the ICE and COR proteins in Poaceae were divided into four groups with high multispecies specificity, respectively. Moreover, expression analysis revealed that mRNA accumulation was altered by cold treatment and the genes of three types involved in the ICE-CBF-COR signaling pathway were induced by cold stress. Together, the results make CBF, ICE, COR genes family in Triticeae more abundant, and provide a starting point for future studies on transcriptional regulatory network for improvement of chilling tolerance in crop.

Gene Regulation and Signal Transduction in the ICE-CBF-COR Signaling Pathway during Cold Stress in Plants.

Low temperature is an abiotic stress that adversely affects the growth and production of plants. Resistance and adaptation of plants to cold stress is dependent upon the activation of molecular networks and pathways involved in signal transduction and the regulation of cold-stress related genes. Because it has numerous and complex genes, regulation factors, and pathways, research on the ICE-CBF-COR signaling pathway is the most studied and detailed, which is thought to be rather important for cold resistance of plants. In this review, we focus on the function of each member, interrelation among members, and the influence of manipulators and repressors in the ICE-CBF-COR pathway. In addition, regulation and signal transduction concerning plant hormones, circadian clock, and light are discussed. The studies presented provide a detailed picture of the ICE-CBF-COR pathway.

Symptomatic sinus tachycardia with perpetuating slow pathway: successful treatment with radiofrequency ablation.

We report a case of sinus tachycardia with perpetuating slow pathway (SP) conduction in a 42-year-old woman who developed severe symptoms as a result of atrioventricular (AV) desynchronization. The restoration of an AV synchrony, achieved with selective radiofrequency ablation of the SP, eliminated the symptomatic arrhythmia and may represent a reasonable therapeutic option despite the fact that the patient has no AV-node reentrant tachycardia. This case demonstrates the importance of AV timing.

Regulatory mechanisms of long non-coding RNAs on mitochondrial function in congestive heart failure.

Congestive heart failure (CHF) is a multifaceted cardiovascular condition that imposes significant economic and social burdens on society, while also presenting a dearth of efficacious treatment modalities. Long non-coding RNAs (lncRNAs) possess the ability to influence the pathophysiological mechanisms underlying cardiac disease through their regulation of gene transcription, translation, and post-translational modifications. Additionally, certain lncRNAs can be encoded by the mitochondrial genome, hence impacting mitochondrial function. The heart relies heavily on mitochondrial oxidative phosphorylation for approximately 95 % of its ATP production. Consequently, the primary determinant linking mitochondrial dysfunction to heart failure is the impairment of cardiac energy supply resulting from mitochondrial injury. Cardiac dysfunction can arise as a result of various factors, including metabolic disease, disturbances in calcium homeostasis, oxidative stress, apoptosis, and mitochondrial phagocytosis, all of which are facilitated by mitochondrial damage. Currently, an increasing body of research indicates that lncRNA plays a significant role in the regulation of mitochondrial activity, hence impacting heart failure. As a result, the goal of this paper is to propose new ideas and targets for clinical research and therapy of heart failure by reviewing recent research on the regulatory mechanism of mitochondrial function by novel lncRNAs.