A circRNA-miRNA-mRNA network analysis underlying pathogenesis of human heart failure.

BACKGROUND: The molecular mechanisms of heart failure (HF) are still poorly understood. Circular RNA (circRNA) has been discovered in the heart in increasing numbers of studies. The goal of this research is to learn more about the potential roles of circRNAs in HF. METHODS & RESULTS: We used RNA sequencing data to identify the characteristics of circRNAs expressed in the heart and discovered that the majority of circRNAs screened were less than 2000 nt. Additionally, chromosomes One and Y had the most and least number of circRNAs, respectively. After excluding duplicate host genes and intergenic circRNAs, a total of 238 differentially expressed circRNAs (DECs) and 203 host genes were discovered. However, only four of the 203 host genes of DECs were examined in HF differentially expressed genes. Another study used Gene Oncology analysis of DECs host genes to elucidate the underlying pathogenesis of HF, and it found that binding and catalytic activity accounted for a large portion of DECs. Immune system, metabolism, and signal transduction pathways were significantly enriched. Furthermore, 1052 potentially regulated miRNAs from the top 40 DECs were collected to build a circRNA-miRNA network, and it was discovered that 470 miRNAs can be regulated by multiple circRNAs, while others are regulated by a single circRNA. In addition, a comparison of the top 10 mRNAs in HF and their targeted miRNAs revealed that DDX3Y and UTY were regulated by the most and least circRNA, respectively. CONCLUSION: These findings demonstrated circRNAs have species and tissue specific expression patterns; while circRNA expression is independent on host genes, the same types of genes in DECs and DEGs worked in HF. Our findings would contribute to a better understanding of the critical roles of circRNAs and lay the groundwork for future studies of HF molecular functions.

Protections of transcription factor BACH2 and natural product myricetin against pathological cardiac hypertrophy and dysfunction.

Pathological hypertrophic myocardium under consistent adverse stimuli eventually can cause heart failure. This study aims to explore the role of BACH2, a member of the basic region leucine zipper transcription factor family, in cardiac hypertrophy and failure. Transverse aortic constriction surgery was operated to induce cardiac hypertrophy and failure in mice. BACH2 was overexpressed in mice through tail vein injection of AAV9-Bach2. Mice with systemic or cardiac-specific knockdown of Bach2 were adopted. Neonatal rat ventricular myocytes (NRVMs) were isolated and infected with lentivirus to overexpress Bach2 or transfected with siRNA to knock down Bach2. Our data showed that overexpression of BACH2 ameliorated TAC-induced cardiac hypertrophy and failure in mice and decreased isoproterenol (ISO)-triggered myocyte hypertrophy in NRVMs. Systemic or cardiac-specific knockdown of Bach2 worsened the cardiac hypertrophy and failure phenotype in mice. Further assays showed that BACH2 bound to the promotor region of Akap6 at the -600 to -587 site and repressed its expression, which functioned as a crucial scaffold for cardiac hypertrophy and failure signaling pathways. Small molecular natural product library screening suggested that myricetin could up-regulate expression of Bach2 and simultaneously suppress the transcriptional levels of hypertrophic marker genes Bnp and Myh7. Further studies showed that myricetin exerted a BACH2-dependent protective effect against cardiac hypertrophy in vivo and in vitro. Taken together, our findings demonstrated that BACH2 plays a crucial role in the regulation of cardiac hypertrophy and failure and can be a potential therapeutic target in the future.

Surgically Induced Cardiac Volume Overload by Aortic Regurgitation in Mouse.

Aortic regurgitation (AR) is a common valvular heart disease that exerts volume overload on the heart and represents a global public health problem. Although mice are widely applied to shed light on the mechanisms of cardiovascular disease, mouse models of AR, especially those induced by surgery, are still paucity. Here, a mouse model of AR was described in detail which is surgically induced by disruption of the aortic valves under high-resolution echocardiography. In accordance with regurgitated blood flow, AR mouse hearts present a distinctive and clinically relevant volume overload phenotype, which is characterized by eccentric hypertrophy and cardiac dysfunction, as evidenced by echocardiographic and invasive hemodynamic evaluation. Our proposal, in a reliable and reproducible manner, provides a practical guide on the establishment and assessment of a mouse model of AR for future studies on molecular mechanisms and therapeutic targets of volume overload cardiomyopathy.

Predicting Tumor Mutational Burden From Lung Adenocarcinoma Histopathological Images Using Deep Learning.

Tumor mutation burden (TMB) is an important biomarker for tumor immunotherapy. It plays an important role in the clinical treatment process, but the gold standard measurement of TMB is based on whole exome sequencing (WES). WES cannot be done in most hospitals due to its high cost, long turnaround times and operational complexity. To seek out a better method to evaluate TMB, we divided the patients with lung adenocarcinoma (LUAD) in TCGA into two groups according to the TMB value, then analyzed the differences of clinical characteristics and gene expression between the two groups. We further explored the possibility of using histopathological images to predict TMB status, and developed a deep learning model to predict TMB based on histopathological images of LUAD. In the 5-fold cross-validation, the area under the receiver operating characteristic (ROC) curve (AUC) of the model was 0.64. This study showed that it is possible to use deep learning to predict genomic features from histopathological images, though the prediction accuracy was relatively low. The study opens up a new way to explore the relationship between genes and phenotypes.

Ferritinophagy-Mediated Ferroptosis and Activation of Keap1/Nrf2/HO-1 Pathway Were Conducive to EMT Inhibition of Gastric Cancer Cells in Action of 2,2'-Di-pyridineketone Hydrazone Dithiocarbamate Butyric Acid Ester.

In metastasis of cancer cells, the epithelial-mesenchymal transition (EMT) is prerequired. Ferroptosis is an iron-mediated cellular death process, but whether it involves EMT regulation remains elusive. In addition, how stress responders (Nrf2) respond to the redox alteration and cross-talking between them needs to be determined. Our data revealed that DpdtbA (2,2'-di-pyridineketone hydrazone dithiocarbamate butyric acid ester) resisted TGF-ß1-induced EMT in gastric cancer lines (SGC-7901 and MGC-823) through ferritinophagy-mediated ROS production. Furthermore, the depletion of Gpx4 and xCT as well as enhanced lipid peroxidation indicated that DpdtbA acted as Erastin did in ferroptosis induction, which thus provided chance to explore the causal relationship between ferroptosis and EMT. Our data illustrated that ferritinophagy-mediated ferroptosis promoted the EMT inhibition. In addition, activated Nrf2 involved the regulation on both ferroptosis and EMT in response to the alteration in the cellular redox environment. In brief, ferritinophagy-mediated ferroptosis and activation of the Keap1/Nrf2/HO-1 pathway were conducive to the EMT inhibition.

Deep Learning-Based Computed Tomography Imaging to Diagnose the Lung Nodule and Treatment Effect of Radiofrequency Ablation.

This study aimed to detect and diagnose the lung nodules as early as possible to effectively treat them, thereby reducing the burden on the medical system and patients. A lung computed tomography (CT) image segmentation algorithm was constructed based on the deep learning convolutional neural network (CNN). The clinical data of 69 patients with lung nodules diagnosed by needle biopsy and pathological comprehensive diagnosis at hospital were collected for specific analysis. The CT image segmentation algorithm was used to distinguish the nature and volume of lung nodules and compared with other computer aided design (CAD) software (Philips ISP). 69 patients with lung nodules were treated by radiofrequency ablation (RFA). The results showed that the diagnostic sensitivity of the CT image segmentation algorithm based on the CNN was obviously higher than that of the Philips ISP for solid nodules <5 mm (63 cases vs. 33 cases) (P < 0.05); it was the same result for the subsolid nodule <5 mm (33 case vs. 5 cases) (P < 0.05) that was slightly higher for solid and subsolid nodules with a diameter of 5-10 mm (37 cases vs. 28 cases) (P < 0.05). In addition, the CNN algorithm can reach all detection for calcified nodules and pleural nodules (7 cases; 5 cases), and the diagnostic sensitivities were much better than those of Philips ISP (2 cases; 3 cases) (P < 0.05). Patients with pulmonary nodules treated by RFA were in good postoperative condition, with a half-year survival rate of 100% and a one-year survival rate of 72.4%. Therefore, it could be concluded that the CT image segmentation algorithm based on the CNN could effectively detect and diagnose the lung nodules early, and the RFA could effectively treat the lung nodules.

Activating AhR alleviates cognitive deficits of Alzheimer's disease model mice by upregulating endogenous Aß catabolic enzyme Neprilysin.

Rationale: Neprilysin (NEP) is a major endogenous catabolic enzyme of amyloid ß (Aß). Previous studies have suggested that increasing NEP expression in animal models of Alzheimer's disease had an ameliorative effect. However, the underlying signaling pathway that regulates NEP expression remains unclear. The aryl hydrocarbon receptor (AhR) is a ligand-activated cytoplasmic receptor and transcription factor. Recent studies have shown that AhR plays essential roles in the central nervous system (CNS), but its physiological and pathological roles in regulating NEP are not entirely known. Methods: Western blotting, immunofluorescence, quantitative RT-PCR and enzyme activity assay were used to verify the effects of AhR agonists on NEP in a cell model (N2a) and a mouse model (APP/PS1). Luciferase reporter assay and chromatin immunoprecipitation (ChIP) assay were conducted to investigate the roles of AhR in regulating NEP transcription. Object recognition test and the Morris water maze task were performed to assess the cognitive capacity of the mice. Results: Activating AhR by the endogenous ligand L-Kynurenine (L-KN) or FICZ, or by the exogenous ligand diosmin or indole-3-carbinol (I3C) significantly increases NEP expression and enzyme activity in N2a cells and APP/PS1 mice. We also found that AhR is a direct transcription factor of NEP. Diosmin treatment effectively ameliorated the cognitive disorder and memory deficit of APP/PS1 transgenic mice. By knocking down AhR or using a small molecular inhibitor targeting AhR or NEP, we found that diosmin enhanced Aß degradation through activated AhR and increased NEP expression. Conclusions: These results indicate a novel pathway for regulating NEP expression in neurons and that AhR may be a potential therapeutic target for the treatment of Alzheimer's disease.

Isolation, Identification, and Evaluation of the Pathogenicity of a Porcine Enterovirus G Isolated From China.

Enterovirus G (EV-G) infects porcine populations worldwide and the infections are generally asymptomatic, with the insertion of the papain-like cysteine protease gene (PLCP) increasing the potential public health threats. However, the genetic and pathogenic characteristics of EV-G itself are not fully understood as yet. In the present study, one EV-G strain, named CH/17GXQZ/2017, was isolated and purified from piglets with diarrheic symptoms from the Guangxi Province, China. This strain produced stable cytopathic effects on Marc-145 cells with a titer of 5 × 106 PFU/mL. The spherical enterovirus particles with diameters of 25-30 nm were observed by using transmission electron microscopy. The whole genome sequence of the CH/17GXQZ/2017 strain consists of 7,364 nucleotides, and the phylogenetic tree based on the amino acid sequences of VP1 indicated this strain was clustered to the G1 genotype. Seven-day-old piglets were inoculated orally with the CH/17GXQZ/2017 strain in order to evaluate its pathogenicity. Although none of the infected piglets died during the experiment, clinical neurological symptoms were observed manifesting as mild hyperemia and Nissl bodies vacuolization in the cerebrum. In addition, the infection with the CH/17GXQZ/2017 strain decelerated the weight gain of suckling piglets significantly. This study demonstrates that CH/17GXQZ/2017 is pathogenic to neonatal piglets and advance knowledge on the biological characteristics, evolution and pathogenicity of EV-G.

Characterization of a nap1l1 transgenic reporter in zebrafish.

Nap1l1 gene encodes a tissue specific nucleosome assembly protein and is essential for tissue development. Here, we report the generation and characterization of a nap1l1 transgenic reporter in zebrafish model. We showed that a 5-kilobase (kb) genomic fragment immediately upstream of the nap1l1 gene transcription initiation site is capable of targeting the nucleic enhanced green fluorescence protein (EGFP) expression initially to central nervous system and subsequently to lateral line neuromasts, cardiomyocytes, and paraxial vessels, where the endogenous nap1l1 normally expresses with only a few exception. In adulthood, zebrafish nap1l1 promoter-driving nEGFP is predominantly expressed in lateral line system, liver, and ovary, but not in heart. Therefore, this novel transgenic reporter line, Tg(nap1l1:nEGFP)zs102, would be a valuable tool for studying the development and regeneration of lateral line system and also for investigating cardiac development.

Expression of nucleosome assembly protein 1 like genes in zebrafish embryos.

Nucleosome assembly protein 1-like (Nap1l) family plays numerous biological roles including nucleosome assembly, transcriptional regulation, and cell cycle progression. However, the tissue specific in vivo functions of the Nap1l family members remain largely unknown. In this study, we finished the complete expression patterns of nap1l1 and nap1l4a in zebrafish embryos by whole-mount in situ hybridization. We observed maternal existence of nap1l1 transcript and that its zygotic expression is abundant and not spatially restricted at 6 somite stage, while nap1l4a mRNA is not detectable until 6 somite stage when it is weakly transcribed throughout the embryo. At 24 h post-fertilization (hpf), nap1l1 is predominantly expressed in the central nervous system, neural tube, ventral mesoderm, branchial arches, and pectoral fins, while nap1l4a mRNA is throughout the embryo, enriched in the eyes, tectum, and myotomes. As the embryo develops, nap1l1 expression maintains throughout the head, with gradually enriched in the tectum, olfactory vesicle, lens, optic cups, heart, branchial arches, pectoral fins, axial vasculature, pronephros, and lateral line neuromasts, whereas nap1l4a expression is weak in the tectum, branchial arches, and pectoral fins. Overall, these expression analyses provide a valuable basis for the functional study of nap1l family in zebrafish development.

Mechanical stresses induce paracrine ß-2 microglobulin from cardiomyocytes to activate cardiac fibroblasts through epidermal growth factor receptor.

By employing a proteomic analysis on supernatant of mechanically stretched cardiomyocytes, we found that stretch induced a significantly high level of ß-2 microglobulin (ß2M), a non-glycosylated protein, which is related to inflammatory diseases but rarely known in cardiovascular diseases. The present data showed that serum ß2M level was increased in patients with hypertension and further increased in patients with chronic heart failure (HF) as compared with control group, and the high level of serum ß2M level correlated to cardiac dysfunction in these patients. In pressure overload mice model by transverse aortic constriction (TAC), ß2M levels in serum and heart tissue increased progressively in a time-dependent manner. Exogenous ß2M showed pro-fibrotic effects in cultured cardiac fibroblasts but few effects in cardiomyocytes. Adeno-associated virus 9 (AAV9)-mediated knockdown of ß2M significantly reduced cardiac ß2M level and inhibited myocardial fibrosis and cardiac dysfunction but not cardiac hypertrophy at 4 weeks after TAC. In vitro, mechanical stretch induced the rapid secretion of ß2M mainly from cardiomyocytes by activation of extracellular-regulated protein kinase (ERK). Conditional medium (CM) from mechanically stretched cardiomyocytes activated cultured cardiac fibroblasts, and the effect was partly abolished by CM from ß2M-knockdown cardiomyocytes. In vivo, knockdown of ß2M inhibited the increase in phosphorylation of epidermal growth factor receptor (EGFR) induced by TAC. In cultured cardiac fibroblasts, inhibition of EGFR significantly attenuated the ß2M-induced the activation of EGFR and pro-fibrotic responses. The present study suggests that ß2M is a paracrine pro-fibrotic mediator and associated with cardiac dysfunction in response to pressure overload.

Endogenous hormone 2-methoxyestradiol suppresses venous hypertension-induced angiogenesis through up- and down-regulating p53 and id-1.

Brain arteriovenous malformations (AVMs) which associate with angiogenesis due to local hypertension, chronic cerebral ischaemia and tissue hypoxia usually lead to haemorrhage, however, the therapeutic medicine for the disease is still lacking. 2-methoxyestradiol (2-ME) has been shown effective in the anti-angiogenic treatment. This study was conducted to examine whether and how 2-ME could improve the vascular malformations. Intracranial venous hypertension (VH) model produced in adult male Sprague-Dawley rats and culture of human umbilical vein endothelial cells (HUVECs) at the anoxia condition were used to induce in vivo and in vitro angiogenesis, respectively. Lentiviral vectors of ID-1 and p53 genes and of their siRNA were intracranially injected into rats and transfected into HUVECs to overexpress and down-regulate these molecules. 2-ME treatment not only reduced the in vivo progression of brain tissue angiogenesis in the intracranial VH rats and the in vitro increases in microvasculature formation, cellular migration and HIF-1α expression induced by anoxia in HUVECs but also reversed the up-regulation of ID-1 and down-regulation of p53 in both the in vivo and in vitro angiogenesis models. All of the anti-angiogenesis effects of 2-ME observed in VH rats and anoxic HUVECs were abrogated by ID-1 overexpression and p53 knockdown. Our data collectively suggest that 2-ME treatment inhibits hypoxia/anoxia-induced angiogenesis dependently on ID-1 down-regulation and p53 up-regulation, providing a potential alternative medical treatment for un-ruptured AVM patients.

Qiliqiangxin protects against anoxic injury in cardiac microvascular endothelial cells via NRG-1/ErbB-PI3K/Akt/mTOR pathway.

Cardiac microvascular endothelial cells (CMECs) are important angiogenic components and are injured rapidly after cardiac ischaemia and anoxia. Cardioprotective effects of Qiliqiangxin (QL), a traditional Chinese medicine, have been displayed recently. This study aims to investigate whether QL could protect CMECs against anoxic injury and to explore related signalling mechanisms. CMECs were successfully cultured from Sprague-Dawley rats and exposed to anoxia for 12 hrs in the absence and presence of QL. Cell migration assay and capillary-like tube formation assay on Matrigel were performed, and cell apoptosis was determined by TUNEL assay and caspase-3 activity. Neuregulin-1 (NRG-1) siRNA and LY294002 were administrated to block NRG-1/ErbB and PI3K/Akt signalling, respectively. As a result, anoxia inhibited cell migration, capillary-like tube formation and angiogenesis, and increased cell apoptosis. QL significantly reversed these anoxia-induced injuries and up-regulated expressions of NRG-1, phospho-ErbB2, phospho-ErbB4, phospho-Akt, phospho-mammalian target of rapamycin (mTOR), hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) in CMECs, while NRG-1 knockdown abolished the protective effects of QL with suppressed NRG-1, phospho-ErbB2, phospho-ErbB4, phospho-Akt, phospho-mTOR, HIF-1α and VEGF expressions. Similarly, LY294002 interrupted the beneficial effects of QL with down-regulated phospho-Akt, phospho-mTOR, HIF-1α and VEGF expressions. However, it had no impact on NRG-1/ErbB signalling. Our data indicated that QL could attenuate anoxia-induced injuries in CMECs via NRG-1/ErbB signalling which was most probably dependent on PI3K/Akt/mTOR pathway.

Nucleosome Assembly Protein 1-Like 1 (Nap1l1) Regulates the Proliferation of Murine Induced Pluripotent Stem Cells.

BACKGROUND/AIMS: To investigate whether nucleosome assembly protein 1-like 1 (Nap1l1) regulates the proliferation of induced pluripotent stem cells (iPSC) and the potential mechanisms. METHODS: Nap1l1-knockdown-iPSC and Nap1l1-overexpression-iPSC were constructed by transfection of lentiviral particles. The proliferation of iPSC was detected by MTT analysis, and cell cycle was analyzed by flow cytometry. RESULTS: Nap1l1 overexpression promoted iPSC proliferation and induced G2/M transition compared to their control iPSC while Nap1l1-knockdown-iPSC dramatically displayed the reduced proliferation and accumulated G2/M phase cells. Further analysis showed that Nap1l1 overexpression in iPSC increased the expression of cyclin B1, downregulated the expression of p21 and p27, while knockdown of Nap1l1 showed the opposite effects. In addition, overexpression of Nap1l1 promoted the phosphorylation of AKT and ERK in iPSC, while knockdown of Nap1l1 inhibited the effects. However, these effects displayed in Nap1l1-overexpression-iPSC were greatly suppressed by the inhibition of AKT or ERK signaling. CONCLUSIONS: The results indicate that Nap1l1 promotes the proliferation of iPSC attributable to G2/M transition caused by downregulation of p27 and p21, and upregulation of cyclin B1, the activation of AKT or ERK is involved in the process. The present study has revealed a novel molecular mechanism involved in the proliferation of iPSC.

Urotensin II Protects Cardiomyocytes from Apoptosis Induced by Oxidative Stress through the CSE/H2S Pathway.

Plasma urotensin II (UII) has been observed to be raised in patients with acute myocardial infarction; suggesting a possible cardiac protective role for this peptide. However, the molecular mechanism is unclear. Here, we treated cultured cardiomyocytes with H2O2 to induce oxidative stress; observed the effect of UII on H2O2-induced apoptosis and explored potential mechanisms. UII pretreatment significantly reduced the number of apoptotic cardiomyocytes induced by H2O2; and it partly abolished the increase of pro-apoptotic protein Bax and the decrease of anti-apoptotic protein Bcl-2 in cardiomyocytes induced by H2O2. SiRNA targeted to the urotensin II receptor (UT) greatly inhibited these effects. Further analysis revealed that UII increased the production of hydrogen sulfide (H2S) and the level of cystathionine-γ-lyase (CSE) by activating the ERK signaling in H2O2-treated-cardiomyocytes. Si-CSE or ERK inhibitor not only greatly inhibited the increase in CSE level or the phosphorylation of ERK induced by UII but also reversed anti-apoptosis of UII in H2O2-treated-cadiomyocytes. In conclusion, UII rapidly promoted the phosphorylation of ERK and upregulated CSE level and H2S production, which in turn activated ERK signaling to protect cardiomyocytes from apoptosis under oxidative stress. These results suggest that increased plasma UII level may protect cardiomyocytes at the early-phase of acute myocardial infarction in patients.

Regulation of p53 by jagged1 contributes to angiotensin II-induced impairment of myocardial angiogenesis.

Angiotensin II (AngII) is a major contributor to the development of heart failure, however, the molecular and cellular mechanisms still remain elucidative. Inadequate angiogenesis in myocardium leads to transition from cardiac hypertrophy to dysfunction, this study was therefore conducted to examine the effects of AngII on myocardial angiogenesis and the underlying mechanisms. AngII treatment significantly impaired angiogenetic responses, which were determined by counting the capillaries either in matrigel formed by cultured cardiac microvascular endothelial cells (CMVECs) or in myocardium of mice and by measuring the in vitro and in vivo production of VEGF proteins, and stimulated accumulation and phosphorylation of cytosolic p53 which led to increases in phosphorylated p53 and decreases of hypoxia inducible factor (Hif-1) in nucleus. All of these cellular and molecular events induced by AngII in CEMCs and hearts of mice were largely reduced by a p53 inhibitor, pifithrin-α (PFT-α). Interestingly, AngII stimulated the upregulation of Jagged1, a ligand of Notch, but it didn't affect the expression of Delta-like 4 (Dll-4), another ligand of Notch. Inhibition of p53 by PFT-α partly abolished this effect of AngII. Further experiments showed that knockdown ofJagged1 by addition of siRNA to cultured CMVECs dramatically declined AngII-stimulated accumulation and phosphorylation of p53 in cytosol, upregulation of phosphorylated p53 and downregulation of Hif-1 expression in nucleus, decrease of VEGF production and impairment of capillary-like tube formation by the cells. Our data collectively suggest that AngII impairs myocardial angiogenetic responses through p53-dependent downregulation of Hif-1 which is regulated by Jagged1/Notch1 signaling.

Association of Stat3 with HSF1 plays a critical role in G-CSF-induced cardio-protection against ischemia/reperfusion injury.

Granulocyte colony-stimulating factor (G-CSF) has been shown to be cardio-protective against ischemia through activating Jak2/Stat3 pathway, however, the mechanism is unclear. Heat shock transcription factor 1 (HSF1), a definite endogenous protective protein in cardiomyocytes, may interact with Stat family under stress conditions. We hypothesized that G-CSF could induce cardio-protection against ischemia/reperfusion (I/R) through association of HSF1 with Stat3. To test the hypothesis, we built cardiac I/R injury model with HSF1 knockout (KO) mice and wild type (WT) mice by occlusion of the left anterior descending (LAD) coronary artery for 30min and subsequent release of the occlusion for 24h. These mice were administered with G-CSF (100µg/kg/day) or vehicle subcutaneously for 3days before surgery. As expected, G-CSF induced significant cardio-protections against I/R injury, characterized by higher ejection fraction (EF%), lower left ventricular end diastolic pressure (LVEDP), increased dp/dt value and decreased infarct area as compared with the vehicle treatment in WT mice. In HSF1-KO mice, however, these cardio-protections induced by G-CSF were greatly attenuated. Inhibition of oxidative stress-induced cardiomyocyte apoptosis by G-CSF also disappeared due to the deficiency of HSF1 in vitro and in vivo. Furthermore, G-CSF increased the phosphorylation and the association of Stat3 with HSF1, which enhanced transcriptional activity of HSF1. Inhibition of either Stat3 or HSF1 by pharmacological agents suppressed G-CSF-induced association of the two proteins and anti-apoptotic effect on cardiomyocytes. Our data suggest that G-CSF stimulates phosphorylation and association of Stat3 with HSF1 and therefore enhances transcriptional activity of HSF1, leading to the cardio-protection against I/R injury.

Gamma-ray up-regulated holocarboxylase synthetase gene.

PURPOSE: To investigate the effects of holocarboxylase synthetase (HCS) gene to irradiation in a time- and dose-dependent manner. MATERIALS AND METHODS: AHH-1 cells, Hela cells, and the nude mice inoculated with tumor cells were exposed to gamma-ray of cobalt 60. The mRNA level of HCS was detected using real-time PCR. The profiles of mRNA of HCS after radiation were analyzed and described. RESULTS: The expression of HCS gene was higher in AHH-1 cells than that in Hela cells. Furthermore, both AHH-1 and Hela displayed similar time-dependent transcriptional levels of HCS gene to radiations at the dose of 2 and 10 Gy. We set the parameters of D, V, R, F, N to quantitatively analyze HCS gene regulation in response to irradiation. We also observed that irradiation resulted in higher levels of HCS in human hepatocyte xenografts, compared with three other types of human tumor xenografts. 2 and 4 Gy radiation had little influence on the HCS gene of human lung cancer and brain cancer, mammary gland cancer was more sensitive to the 4 Gy gamma-ray dose compared with the 2 Gy gamma-ray dose. CONCLUSION: HCS is a good radiation-responsive gene. It may be used as a candidate for developing novel biomarkers of radiation damage and it has a great potential to be used in radiation-therapy of liver tumors.

A "double overlap" suture technique for the proximal attachment of a composite graft to the aortic annulus.

Repair of an aortic root aneurysm using a composite graft is sometimes complicated by proximal suture line bleeding, which may be very difficult to control. We adopted a previously described technique of "double overlap" sutures on the annulus and the prosthetic cuff, which has virtually eliminated this complication.