Causal Relationship Between Gut Microbiota and Aneurysm: A Mendelian Randomization Study

Observational studies have suggested a possible relationship between gut microbiota (GM) and aneurysm development. However, the nature of this association remains unclear due to the inherent limitations of observational research, such as reverse causation and confounding factors. To address this knowledge deficit, this study aimed to investigate and establish a causal link between GM and aneurysm development.

Cardioprotective Strategies After Ischemia-Reperfusion Injury

Acute myocardial infarction (AMI) is associated with high morbidity and mortality worldwide. Although early reperfusion is the most effective strategy to salvage ischemic myocardium, reperfusion injury can develop with the restoration of blood flow. Therefore, it is important to identify protection mechanisms and strategies for the heart after myocardial infarction. Recent studies have shown that multiple intracellular molecules and signaling pathways are involved in cardioprotection. Meanwhile, device-based cardioprotective modalities such as cardiac left ventricular unloading, hypothermia, coronary sinus intervention, supersaturated oxygen (SSO2), and remote ischemic conditioning (RIC) have become important areas of research. Herein, we review the molecular mechanisms of cardioprotection and cardioprotective modalities after ischemia-reperfusion injury (IRI) to identify potential approaches to reduce mortality and improve prognosis in patients with AMI.

Elective Nodal Irradiation vs. Involved-Field Irradiation for Stage Ⅱ-Ⅳ Cervical Esophageal Squamous Cell Carcinoma Patients Undergoing Definitive Concurrent Chemoradiotherapy: A Retrospective Propensity Study with Eight-Year Survival Outcomes

PURPOSE/OBJECTIVE(S)

Definitive concurrent chemoradiotherapy (dCCRT) is suggested as the standard treatment for cervical esophageal squamous cell carcinoma (CESCC). This retrospective propensity study compared the eight-year survival outcomes and acute treatment toxicities of these patients treated with elective nodal irradiation (ENI) versus involved-field irradiation (IFI).

MATERIALS/METHODS

Patients with stage Ⅱ-Ⅳ CESCC treated with dCCRT in our institution between January 1, 2007 and December 31, 2020 were enrolled in the study. All the patients were restaged according to the American Joint Commission (AJCC) 8th edition criteria. The propensity score matching (PSM) was used to minimize the effects of treatment selection bias and potential confounding factors including sex, age, ECOG score, clinical T stage (cT), clinical N stage (cN), clinical TNM stage (cTNM) and radiation dose between the ENI group and IFI group. Survival and the prognostic factors were evaluated.

RESULTS

The 131 eligible patients underwent ENI (60 patients, 45.8%) or IFI (71 patients, 54.2%). The median follow-up time was 95.3 months (range, 28.0-186.2 months) for all the patients. The median OS, 1-, 3-, 5-, and 8-year OS rates were 44.4 months, 87.8%, 55.5%, 39.0%, and 28.3%, respectively. After PSM, there were 49 patients in each group. The median OS, 1-, 3-, 5-, and 8-year OS rates for ENI and IFI group were 32.0 months, 83.7%, 48.9%, 38.8% and 32.4% versus 45.2 months, 89.8%, 52.7%, 38.2%, 26.6%, respectively (P = 0.984; HR 0.99, 95% CI 0.61-1.62). Similar locoregional control was obtained in both groups. The tendency of leukocytopenia and neutropenia was higher in ENI than in IFI (59.2% versus 38.8%; P = 0.068 and 30.6% versus 14.3%; P = 0.089) at the end of dCCRT.

CONCLUSION

Cervical esophageal squamous cell carcinoma patients undergoing definitive concurrent chemoradiotherapy has a satisfactory prognosis with organ conservation. The involved-field irradiation might be a better alternative owing to similar overall survival outcomes and local control with less toxicity of myelosuppression.

Ferroptosis: A potential therapeutic target in autoimmune disease (Review)

Ferroptosis is a distinct type of regulated cell death characterized by iron overload and lipid peroxidation. Ferroptosis is regulated by numerous factors and controlled by several mechanisms. This cell death type has a relationship with the immune system, which may be regulated by damage-associated molecular patterns. Ferroptosis participates in the progression of autoimmune diseases, including autoimmune hepatitis, rheumatoid arthritis, systemic lupus erythematosus, inflammatory bowel disease, multiple sclerosis, Parkinson's Disease, psoriasis and insulin-dependent diabetes mellitus. The present review summarizes the role of ferroptosis in autoimmune disorders and discusses ferroptosis as a potential therapeutic target for autoimmune disease.

Identification of potential serum biomarkers for congenital heart disease children with pulmonary arterial hypertension by metabonomics

BACKGROUND

Pulmonary arterial hypertension is a common complication in patients with congenital heart disease. In the absence of early diagnosis and treatment, pediatric patients with PAH has a poor survival rate. Here, we explore serum biomarkers for distinguishing children with pulmonary arterial hypertension associated with congenital heart disease (PAH-CHD) from CHD.

METHODS

Samples were analyzed by nuclear magnetic resonance spectroscopy-based metabolomics and 22 metabolites were further quantified by ultra-high-performance liquid chromatography-tandem mass spectroscopy.

RESULTS

Serum levels of betaine, choline, S-Adenosyl methionine (SAM), acetylcholine, xanthosine, guanosine, inosine and guanine were significantly altered between CHD and PAH-CHD. Logistic regression analysis showed that combination of serum SAM, guanine and N-terminal pro-brain natriuretic peptide (NT-proBNP), yielded the predictive accuracy of 157 cases was 92.70% with area under the curve of the receiver operating characteristic curve value of 0.9455.

CONCLUSION

We demonstrated that a panel of serum SAM, guanine and NT-proBNP is potential serum biomarkers for screening PAH-CHD from CHD.

Intestinal Flora Metabolite Trimethylamine Oxide Is Inextricably Linked to Coronary Heart Disease

ABSTRACT

Atherosclerotic coronary heart disease is a common cardiovascular disease with high morbidity and mortality. In recent years, the incidence of coronary heart disease has gradually become younger, and biomarkers for predicting coronary heart disease have demonstrated valuable clinical prospects. Several studies have established an association between coronary heart disease and intestinal flora metabolites, including trimethylamine oxide (TMAO), which has attracted widespread attention from researchers. Investigations have also shown that plasma levels of TMAO and its precursors can predict cardiovascular risk in humans; however, TMAO's mechanism of action in causing coronary heart disease is not fully understood. This review examines TMAO's generation, the mechanism through which it causes coronary heart disease, and the approaches used to treat TMAO-caused coronary heart disease to possible avenues for future research on coronary heart disease and find new concepts for the treatment of the condition.

Intestinal Flora Derived Metabolites Affect the Occurrence and Development of Cardiovascular Disease

In recent years, increasing evidence has shown that the gut microbiota and their metabolites play a pivotal role in human health and diseases, especially the cardiovascular diseases (CVDs). Intestinal flora imbalance (changes in the composition and function of intestinal flora) accelerates the progression of CVDs. The intestinal flora breaks down the food ingested by the host into a series of metabolically active products, including trimethylamine N-Oxide (TMAO), short-chain fatty acids (SCFAs), primary and secondary bile acids, tryptophan and indole derivatives, phenylacetylglutamine (PAGln) and branched chain amino acids (BCAA). These metabolites participate in the occurrence and development of CVDs via abnormally activating these signaling pathways more swiftly when the gut barrier integrity is broken down. This review focuses on the production and metabolism of TMAO and SCFAs. At the same time, we summarize the roles of intestinal flora metabolites in the occurrence and development of coronary heart disease and hypertension, pulmonary hypertension and other CVDs. The theories of "gut-lung axis" and "gut-heart axis" are provided, aiming to explore the potential targets for the treatment of CVDs based on the roles of the intestinal flora in the CVDs.

Coronary functional assessment in non-obstructive coronary artery disease: Present situation and future direction

Non-obstructive coronary artery disease (CAD), which is defined as coronary stenosis <50%, has been increasingly recognized as an emerging entity in clinical practice. Vasomotion abnormality and coronary microvascular dysfunction are two major mechanisms contributing to the occur of angina with non-obstructive CAD. Although routine coronary functional assessment is limited due to several disadvantages, functional evaluation can help to understand the pathophysiological mechanism and/or to exclude specific etiologies. In this review, we summarized the potential mechanisms involved in ischemia with non-obstructive coronary arteries (INOCA) and myocardial infarction with non-obstructive coronary arteries (MINOCA), the two major form of non-obstructive CAD. Additionally, we reviewed currently available functional assessment indices and their use in non-obstructive CAD. Furthermore, we speculated that novel technique combined anatomic and physiologic parameters might provide more individualized therapeutic choice for patients with non-obstructive CAD.

Targeting Trimethylamine N-Oxide: A New Therapeutic Strategy for Alleviating Atherosclerosis

Atherosclerosis (AS) is one of the most common cardiovascular diseases (CVDs), and there is currently no effective drug to reverse its pathogenesis. Trimethylamine N-oxide (TMAO) is a metabolite of the gut flora with the potential to act as a new risk factor for CVD. Many studies have shown that TMAO is involved in the occurrence and development of atherosclerotic diseases through various mechanisms; however, the targeted therapy for TMAO remains controversial. This article summarizes the vital progress made in relation to evaluations on TMAO and AS in recent years and highlights novel probable approaches for the prevention and treatment of AS.

Impact of anemia on in-stent restenosis after percutaneous coronary intervention

Background

Anemia is a common risk factor for post-percutaneous coronary intervention (PCI) adverse events; however, data on its association with in-stent restenosis (ISR) is limited.

Methods

538 patients who underwent PCI between January 2017 and September 2019 and follow-up angiography 9–12 months after the initial PCI were enrolled in this study. Baseline clinical and procedural characteristics were compared between the ISR and non-ISR groups, and independent predictors of ISR were determined using propensity score matching.

Results

The incidence of anemia was 53.5% in patients with ISR and 19.0% in those without ISR. Univariable logistic regression analyses showed that anemia (OR, 4.283; 95% CI, 1.949–9.410; P < 0.001), diabetes mellitus (OR, 2.588; 95% CI, 1.176–5.696; P = 0.018), chronic kidney disease (OR, 3.058; 95% CI, 1.289–7.252; P = 0.011), multiple stenting (OR, 2.592; 95% CI, 1.205–5.573; P = 0.015), bifurcation lesion (OR, 2.669; 95% CI, 1.236–5.763; P = 0.012), and calcification (OR, 3.529; 95% CI, 1.131–11.014; P = 0.030) were closely associated with ISR. Low-density lipoprotein cholesterol (LDL-c) levels and stent diameter were also significantly linked to ISR, as was anemia (P = 0.009) after propensity score matching.

Conclusion

Anemia is closely associated with post-PCI ISR, and patients with lower hemoglobin levels are at a higher risk of ISR.

Ferroptosis: A Novel Therapeutic Target for Ischemia-Reperfusion Injury

Ischemia-reperfusion (I/R) injury is a major cause of cell death and organ damage in numerous pathologies, including myocardial infarction, stroke, and acute kidney injury. Current treatment methods for I/R injury are limited. Ferroptosis, which is a newly uncovered type of regulated cell death characterized by iron overload and lipid peroxidation accumulation, has been investigated in various diseases. There is increasing evidence of a close association between ferroptosis and I/R injury, with ferroptosis frequently identified as a new therapeutic target for the management of I/R injury. This review summarizes the current status of ferroptosis and discusses its relationship with I/R injury, as well as potential treatment strategies targeting it.

The Link Between Ferroptosis and Cardiovascular Diseases: A Novel Target for Treatment

Ferroptosis is an iron-dependent cell death, which is characterized by iron overload and lipid peroxidation. Ferroptosis is distinct from apoptosis, necroptosis, autophagy, and other types of cell death in morphology and function. Ferroptosis is regulated by a variety of factors and controlled by several mechanisms, including mitochondrial activity and metabolism of iron, lipid, and amino acids. Accumulating evidence shows that ferroptosis is closely related to a majority of cardiovascular diseases (CVDs), including cardiomyopathy, myocardial infarction, ischemia/reperfusion injury, heart failure, and atherosclerosis. This review summarizes the current status of ferroptosis and discusses ferroptosis as a potential therapeutic target for CVDs.

Knockdown of circ_0060745 alleviates acute myocardial infarction by suppressing NF-κB activation

It has been shown that circRNAs are involved in the development of heart diseases. However, few studies explored the role of circRNAs in acute myocardial infarction (AMI). The present study aims to investigate the role of circ_0060745 in the pathogenesis of AMI. We found that the expression of circ_0060745 was significantly increased in the myocardium of AMI mice and was mainly expressed in myocardial fibroblasts. The knockdown of circ_0060745 decreased myocardial infarct size and improved systolic cardiac functions after AMI. The knockdown of circ_0060745 in cardiac fibroblasts inhibited the migration of peritoneal macrophage, the apoptosis of cardiomyocytes and the expressions of IL‐6, IL‐12, IL‐1β, TNF‐α and NF‐κB under hypoxia. Overexpression of circ_0060745 caused an increase in infarct size and worsened cardiac functions after AMI. In summary, our findings showed that knockdown of circ_0060745 mitigates AMI by suppressing cardiomyocyte apoptosis and inflammation. These protective effects could be attributed to inhibition of NF‐κB activation.

MicroRNA-101a protects against the H2O2-induced injury on cardiomyocytes via targeting BCL2L11

OBJECTIVE

MicroRNAs (miRs) have been confirmed to be involved in the development of cardiovascular diseases, in spite of numerous studies elucidating the effect and mechanism of miRs in the progression of cardiac ischemia reperfusion injury (I/R), the understanding of their roles is still limited.

METHODS

All rats underwent the same I/R procedure, while sham group experienced the surgical procedure but without the ligation of left anterior descending coronary artery (LAD).

RESULTS

Here, we found miR-101a which was proved down-regulated significantly in myocardium and cariomyocytes subjected to I/R and H₂O₂ treatment respectively. In vivo and in vitro studies determined the protective role of miR-101a from I/R and oxidative stress injury. It attenuated the size of ischemia area and the cardiomycyte apoptosis under I/R and H₂O₂ treatment. Mechanically, BCL2L11 was predicted and then verified to be targeted by miR-101a. Moreover, rescue experiment and RNA pull down further verified the interaction between miR-101a and BCL2L11.

CONCLUSIONS

Our findings revealed miR-101a may be a therapeutic target for the therapeutic target for ischemic heart diseases and expanded our understanding of the molecular mechanism underling the progression of I/R injury.

Delphinidin attenuates pathological cardiac hypertrophy via the AMPK/NOX/MAPK signaling pathway

Reactive oxygen species (ROS) play a pivotal role in the development of pathological cardiac hypertrophy. Delphinidin, a natural flavonoid, was reported to exert marked antioxidative effects. Therefore, we investigated whether delphinidin ameliorates pathological cardiac hypertrophy via inhibiting oxidative stress. In this study, male C57BL/6 mice were treated with DMSO or delphinidin after surgery. Neonatal rat cardiomyocytes (NRCMs) were treated with angiotensin II (Ang II) and delphinidin in vitro. Eighteen-month-old mice were administered delphinidin to investigate the effect of delphinidin on aging-related cardiac hypertrophy. Through analyses of hypertrophic cardiomyocyte growth, fibrosis and cardiac function, delphinidin was demonstrated to confer resistance to aging- and transverse aortic constriction (TAC)-induced cardiac hypertrophy in vivo and attenuate Ang II-induced cardiomyocyte hypertrophy in vitro by significantly suppressing hypertrophic growth and the deposition of fibrosis. Mechanistically, delphinidin reduced ROS accumulation upon Ang II stimulation through the direct activation of AMP-activated protein kinase (AMPK) and subsequent inhibition of the activity of Rac1 and expression of p47^phox. In addition, excessive levels of ERK1/2, P38 and JNK1/2 phosphorylation induced by oxidative stress were abrogated by delphinidin. Delphinidin was conclusively shown to repress pathological cardiac hypertrophy by modulating oxidative stress through the AMPK/NADPH oxidase (NOX)/mitogen-activated protein kinase (MAPK) signaling pathway.

Tandem Mass Tag Labeling to Identify Proteome Changes in Beef Longissimus Lumborum and Psoas Major Muscles During Early Postmortem Period

ObjectivesLongissimus lumborum (LL) and psoas major (PM) are important muscles in beef hindquarters that exhibit variation in meat quality attributes. Postmortem metabolism (muscle-to-meat conversion) affects biochemical properties of muscles and in turn influence the meat quality. Although previous research has indicated that variation in the proteome profile of LL and PM post-rigor influences meat quality attributes such as tenderness and color stability during retail display, limited research has examined the influence of early postmortem metabolism on meat quality. Tandem mass tag (TMT) labeling is a chemical labeling approach used for accurate mass spectrometry-based quantification and identification of biological macromolecules. Therefore, the objective of this study was to use TMT labeling to examine proteome profile variation between beef LL and PM during the early postmortem period.Materials and MethodsMuscle biopsy samples were collected from carcasses (n = 4) at 45 min, 12 h, and 36 h postmortem from a commercial beef processing facility. Samples were frozen immediately in liquid nitrogen and stored at –80°C until proteomic analysis. Proteome was analyzed using TMT label containing ten different isobaric compounds with the same mass and chemical structure composed of an amine-reactive NHS-ester group, a spacer arm, and a mass reporter. After labeling and peptide fractionation, all the samples were multiplexed and ran through the Orbitrap Velos mass spectrometer equipped with a Nanospray Flex ion source to identify differentially abundant proteins. The proteins exhibiting 1.5-fold or more intensity difference and a statistical difference (P < 0.05) between LL and PM or within the muscles during the postmortem were reported as differentially abundant.ResultsSeventy differentially abundant proteins (P < 0.05) were identified from three comparisons between the muscles (31 proteins in PM 45 min vs. LL 45 min, 41 proteins in PM 12 h vs. LL 12 h, 49 proteins in PM 36 h vs. LL 36 h). However, no difference (P > 0.05) in protein expression within a muscle was observed during these time points. The differentially abundant proteins were mainly involved in oxidative phosphorylation and ATP-related transport, tricarboxylic acid cycle, NADPH regeneration, fatty acid degradation, muscle contraction, calcium signaling, chaperone activity, oxygen transport, as well as degradation of the extracellular matrix. At early postmortem, overabundant anti-apoptotic proteins in LL could cause high metabolic stability, enhanced autophagy, and delayed apoptosis, while overabundant metabolic enzymes and pro-apoptotic proteins in PM could accelerate the reactive oxygen species generation and programmed cell death.ConclusionDifferentially abundant proteins between LL and PM during the early postmortem were primarily associated with cellular metabolism and programmed cell death. The greater oxidative and color stability in LL compared to PM could be related to the increased expression of anti-apoptotic proteins and the decreased expression of metabolic enzymes and proapoptotic proteins in LL.

Supranutritional Supplementation of Vitamin E Influences the Abundance of Antioxidant Proteins in Postmortem Longissimus Lumborum from Heifers

ObjectivesVitamin E is a lipid-soluble antioxidant that can inhibit lipid oxidation and improve beef color stability. The effect of vitamin E on fresh beef color, from the standpoint of lipid oxidation-induced myoglobin oxidation, have been extensively studied. However, the influence of vitamin E on sarcoplasmic proteome profile of beef skeletal muscles is yet to be investigated. Therefore, the objective of this study was to examine the effect of dietary vitamin E on sarcoplasmic proteome of postmortem beef longissimus lumborum (LL) muscle.Materials and MethodsCrossbred heifers, managed with a GrowSafe feeding system, were fed ad libitum corn-based diet containing either no supplemental (CONT) or 1000 IU vitamin E/heifer per day (VITE) for 89 d. The animals were harvested, and carcasses were chilled. The LL muscle samples were obtained from the carcasses of nine (n = 9) VITE and nine (n = 9) CONT heifers 24 h postmortem. The muscle samples were individually vacuum-packaged and frozen at –80°C for proteome analysis. Sarcoplasmic proteome was analyzed using two-dimensional electrophoresis, employing immobilized pH gradient strips (pH 3–10; 17 cm) in the first dimension and 12% sodium dodecyl sulfate polyacrylamide gel electrophoresis in the second dimension. The gels were scanned, and the digital gel images were analyzed. The protein spots exhibiting more than 1.5-fold intensity differences (P < 0.10) between VITE and CONT were subjected to in-gel tryptic digestion and were identified by tandem mass spectrometry.ResultsFive differentially abundant spots were identified using mass spectrometry, and all the spots were over-abundant in CONT. The proteins in the differentially abundant spots were antioxidant proteins (thioredoxin-dependent peroxide reductase, peroxiredoxin-6, and serum albumin) and glycolytic enzymes (β-enolase and triosephosphate isomerase). The antioxidant proteins minimize oxidation of lipids and proteins in muscle matrix, whereas the glycolytic enzymes generate NADPH, which helps maintain the antioxidant proteins in their reduced forms.ConclusionThe strong antioxidant protection offered by vitamin E could have possibly led to less expression of antioxidant proteins as well as glycolytic enzymes that generate antioxidant metabolites in the VITE group, whereas the lack of such protection in CONT group may have led to increased expression of these proteins in the skeletal muscles.

Ractopamine-Induced Changes in the Mitochondrial Proteome of Postmortem Beef Longissimus Lumborum

ObjectivesRactopamine is a β-adrenergic agonist approved as growth promotant in beef cattle, and it increases muscle deposition while limiting fat deposition. Dietary ractopamine causes a muscle fiber shift in cattle, and the biochemistry of mitochondria in postmortem beef skeletal muscles is influenced by fiber type. Therefore, dietary ractopamine may potentially affect mitochondrial functionality. Nonetheless, the influence of ractopamine on beef skeletal muscle mitochondrial proteome has not been evaluated. Therefore, the objective of this study was to examine the effects of ractopamine on mitochondrial proteome of postmortem longissimus lumborum (LL) from beef cattle.Materials and MethodsPen-housed crossbred steers were fed either a corn-based basal diet (CON) or a diet top-dressed with Optaflexx 45 (Elanco Animal Health) to provide 400 mg of ractopamine hydrochloride/steer per day (RAC). Ractopamine was fed the last 28 d prior to the harvest. The animals were harvested, and carcasses were chilled for 24 h. The LL muscle samples were obtained from nine (n = 9) RAC and nine (n = 9) CON carcasses. Mitochondrial proteome was analyzed using two-dimensional electrophoresis, and the digital gel images were analyzed. The protein spots exhibiting more than 1.5-fold intensity differences (P < 0.10) between RAC and CON were subjected to in-gel tryptic digestion and were identified by tandem mass spectrometry.ResultsSeven differentially abundant proteins were identified in the mitochondrial proteome. Three proteins were over-abundant (P < 0.10) in RAC, whereas four spots were over-abundant in CON. The proteins over-abundant in RAC mitochondrial proteome was complement component 1 Q subcomponent-binding protein, very long-chain specific acyl-CoA dehydrogenase, and aconitate hydratase. On the other hand, ATP synthase subunit β, prohibitin, Cytochrome b-c1 complex subunit, and thioredoxin-dependent peroxide reductase were over-abundant in CON samples. The differentially abundant proteins belong to four functional groups; i.e., energy metabolism (ATP synthase subunit β, Cytochrome b-c1 complex subunit 1, and aconitate hydratase), chaperone activity (complement component 1 Q subcomponent-binding protein and prohibitin), antioxidant activity (thioredoxin-dependent peroxide reductase), and lipid metabolism (very long-chain specific acyl-CoA dehydrogenase).ConclusionDietary ractopamine impacts mitochondrial proteome in postmortem beef LL muscle and influences the abundance of proteins involved in cellular metabolism and protective mechanisms. The increased protein synthesis and leanness previously reported in ractopamine-fed cattle may be attributed to the decreased expression of enzymes involved in respiratory electron transport pathways and the increased expression of enzymes involved in lipolysis.

An effective experimental method and apparatus for unsteady water vapor condensation investigation in high speed expansion flow

This paper presents an effective experimental method and system for mechanism study of unsteady water vapor condensation encountered in high speed expansion flow. We proposed an experimental method and designed a simplified expansion system to fulfill the study. Tunable diode laser absorption spectroscopy (TDLAS) and light sheet technique are integrated in the system to monitor the unsteady condensation process in a high speed expansion flow generated by the expansion system. Two near infrared water vapor absorption transitions (1395.0 nm and 1409.27 nm) and one near infrared methane absorption transition (1653.73 nm) are applied in the TDLAS measurement to measure the transient flow parameters during the condensation process. Using the experimental method, time dependent condensation processes are monitored with different expansion time scales. The light sheet results visually reveal the condensation phenomena during the expansion process, while TDLAS results quantitatively follow the condensation process. The experimental results are compared with computational fluid dynamics simulations and a good agreement between them is observed, which indicates that the presented experimental method and system is effective in investigating unsteady water vapor condensation in high speed expansion flow.

GLI-1 facilitates the EMT induced by TGF-β1 in gastric cancer

OBJECTIVE

To explore how GLI-1 affects the EMT induced by TGF-β1 in gastric cancer.

MATERIALS AND METHODS

Following 24 hours of culture of SGC-7901 cells in presence of TGF-β1, we observed the changes in morphology as well as mRNA and protein expressions of GLI-1, E-cadherin and Vimentin by RT-PCR and Western blot. Transwell assay was conducted to evaluate the changes in invasion ability of SGC-7901 cells. Then, SGC-7901 cells were co-treated with TGF-β1 and GANT 61, and changes of the above indexes were also detected using the corresponding methods.

RESULTS

In presence of TGF-β1, EMT was initiated in SGC-7901 cells EMT with increased cell invasion ability, and the mRNA and protein expressions of E-cadherin were downregulated, while those of the GLI-1 and Vimentin were upregulated. Conversely, the co-treatment of TGF-β1 and GANT 61 suppressed the increased cell invasion ability induced only by TGF-β1, and the changes in mRNA and protein expressions of these factors were abolished.

CONCLUSIONS

We found that GLI-1 facilitates the EMT induced by TGF-β1 in SGC-7901 cells, which may serve as a potential target in developing the clinical treatment of gastric cancer.

Microstructure and mechanical properties of hard Acrocomia mexicana fruit shell

Fruit and nut shells can exhibit high hardness and toughness. In the peninsula of Yucatan, Mexico, the fruit of the Cocoyol palm tree (Acrocomia mexicana) is well known to be very difficult to break. Its hardness has been documented since the 1500 s, and is even mentioned in the popular Maya legend The Dwarf of Uxmal. However, until now, no scientific studies quantifying the mechanical performance of the Cocoyol endocarp has been found in the literature to prove or disprove that this fruit shell is indeed "very hard". Here we report the mechanical properties, microstructure and hardness of this material. The mechanical measurements showed compressive strength values of up to ~150 and ~250 MPa under quasi-static and high strain rate loading conditions, respectively, and microhardness of up to ~0.36 GPa. Our findings reveal a complex hierarchical structure showing that the Cocoyol shell is a functionally graded material with distinctive layers along the radial directions. These findings demonstrate that structure-property relationships make this material hard and tough. The mechanical results and the microstructure presented herein encourage designing new types of bioinspired superior synthetic materials.

MicroRNA-206 Protects against Myocardial Ischaemia-Reperfusion Injury in Rats by Targeting Gadd45β

MicroRNAs are widely involved in the pathogenesis of cardiovascular diseases through regulating gene expression via translational inhibition or degradation of their target mRNAs. Recent studies have indicated a critical role of microRNA-206 in myocardial ischaemia-reperfusion (I/R) injury. However, the function of miR-206 in myocardial I/R injury is currently unclear. The present study was aimed to identify the specific role of miR-206 in myocardial I/R injury and explore the underlying molecular mechanism. Our results revealed that the expression level of miR-206 was significantly decreased both in rat I/R group and H9c2 cells subjected to hypoxia/reoxygenation (H/R) compared with the corresponding control. Overexpression of miR-206 observably decreased infarct size and inhibited the cardiomyocyte apoptosis induced by I/R injury. Furthermore, bioinformatics analysis, luciferase activity and western blot assay proved that Gadd45β (growth arrest DNA damage-inducible gene 45β) was a direct target gene of miR-206. In addition, the expression of pro-apoptotic-related genes, such as p53, Bax and cleaved caspase3, was decreased in association with the down-regulation of Gadd45β. In summary, this study demonstrates that miR-206 could protect against myocardial I/R injury by targeting Gadd45β.

Electrical acupuncture moderately decreases cardiac ischemiareperfusion injury in rats

Restoration of blood flow to the ischemic myocardium termed reperfusion unavoidably leads to many heart complications (such as rhythm abnormalities, and sequentially heart failure), together with the induced damage of cardiomyocytes, which can worsen infarct size and is termed myocardial ischemia-reperfusion (I/R) injury. Electroacupuncture plays an important role in attenuating I/R injury. High mobility group box-1 protein (HMGB1) is upregulated in myocardial I/R injury and activates the inflammatory response which enhances the myocardial injury. In our study, we aimed to detect the roles of electrical acupuncture at Neiguan acupoints (PC6) in myocardial I/R injury and investigate the relationship between electrical acupuncture and HMGB1-related pathway. We found that electrical acupuncture pretreatment protected against myocardial I/R injury through inhibiting cell apoptosis. Electroacupuncture also decreased the expression levels of HMGB1 and inflammatory cytokines induced by I/R injury. In addition, the phosphorylation levels of JNK (c-Jun N-terminal kinase) was decreased by electroacupuncture in heart tissues. Furthermore, the effects of electrical acupuncture pretreatment were abrogated by the additional administration of recombinant HMGB1. Finally, the SP600125 administration, a selective JNK inhibitor, attenuated HMGB1-dependent cell apoptosis and cytokines release in myocardial I/R injury. In conclusion, our data demonstrate that electrical acupuncture at PC6 plays a protective role in myocardial I/R injury, and this effect is associated with inhibited HMGB1-JNK pathway, which provides a beneficial therapeutic strategy for patients with myocardial I/R injury.

WITHDRAWN: Resveratrol increases microRNA-130a expression to promote angiogenesis and improve heart functions in mice after myocardial infarction

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Inhibition of microRNA-1 attenuates hypoxia/re-oxygenation-induced apoptosis of cardiomyocytes by directly targeting Bcl-2 but not GADD45Beta

MicroRNAs are small non-coding RNAs that are able to regulate gene expression and play important roles in some biological and pathological processes, including the myocardial ischemia/reperfusion (I/R) injury. Recent findings demonstrated that miR-1 exacerbated I/R-induced injury. This study was to investigate theanti-apoptotic property of miR-1 inhibition and the potential regulatory mechanism. Results showed miR-1 expression reduced in the heart of rats undergoing myocardial I/R and the cardiomyocytes receiving hypoxia/reoxygenation (H/R) injury, but the serum miR-1 expression increased. The targets of miR-1 were predicted by cDNA microarray, and Bcl-2 and GADD45β were selected as candidate targets. Western blot assay and qPCR showed Bcl-2 and GADD45β protein and mRNA expressions increased after I/R injury and H/R injury. Bcl-2 was a direct target of miR-1 as shown in previous studies. Luciferase assay and Western blot assay revealed GADD45β was a direct target of miR-1, and miR-1 suppressed GADD45β expression via binding to its 3'UTR. Furthermore, miR-1 inhibition increased Bcl-2 expression and reduced IA/AAR (infarct area/area at risk) ratio and cell apoptosis in rats undergoing myocardial I/R as well as in cardiomyocytes receiving H/R injury. Importantly, Bcl-2 knockdown restored these consequences following miR-1 inhibition. However, GADD45β knockdown reduced IA/AAR ratio and cell apoptosis in vivo and in vitro, but failed torestore above consequences after miR-1 inhibition. In conclusion miR-1 inhibition protects against H/R-induced apoptosis of myocytes by directly targeting Bcl-2 but not GADD45β.

[Effects of L-carnitine and bisoprolol on endoplasmic reticulum stress-mediated myocardial injury after cardiopulmonary resuscitation in rats]

OBJECTIVE

To explore the effects of L-carnitine and bisoprolol on endoplasmic reticulum stress-mediated myocardial injury after cardiopulmonary resuscitation in rats.

METHODS

A total of 75 Sprague-Dawley rats were randomly divided into 5 groups of sham operation (sham); cardiopulmonary resuscitation (CR), L-carnitine (L), bisoprolol treatment (B) and L-carnitine and bisoprolol treatment (LB). Myocardial pathological changes were detected by hematoxylin and eosin, myocardial apoptosis by terminal deoxynucleotidyl transferase mediated dUTP nick and the expressions of key factors in endoplasmic reticulum (ER) by Western blot.

RESULTS

Compared with sham group, apoptosis and pathological lesions significantly increased in other groups (P < 0.05). And the levels of GRP78, CHOP and Caspase-12 were significantly higher (P < 0.05). The expression of ER factor protein and the degrees of myocardial injury in LB and B groups decreased compared with CR group. And LB group was the most obvious.

CONCLUSIONS

Combined use of levocarnitine and bisoprolol exerts protective effects on cardiopulmonary resuscitation in rats. And the mechanism may be related to an inhibition of ER stress.

Permanent pacemaker implanted into patient's left ventricle via subclavian artery by mistake: a case report

BACKGROUND

Although various iatrogenic complications could be observed in the process of permanent pacemaker implantation, pacemaker electrode mistakenly implanted into left ventricle via subclavian artery and aortic valve has not been reported.

CASE PRESENTATION

Herein, we reported a 71-year-old woman with permanent pacemaker mistakenly implanted into the left ventricle. During the operation of permanent pacemaker implantation, puncture was performed on her subclavian artery by mistake, and then the pacemaker electrode was put into the cardiac apex of left ventricle via ascending aorta reversely.

CONCLUSION

The further operation could be conducted.

Protective effects of tanshinone IIA on myocardial ischemia reperfusion injury by reducing oxidative stress, HMGB1 expression, and inflammatory reaction

CONTEXT

Although there were reports on the protective functions of tanshinone IIA (TSA) on rat myocardial ischemia, the exerting mechanism has not been completely clarified.

OBJECTIVE

An attempt was made to further verify the protective effect of TSA on myocardial ischemia reperfusion injury and elucidate its underlying mechanism.

MATERIALS AND METHODS

The rats were given TSA (10, 20, and 40 mg/kg bw per day) in intraperitoneal injection for 15 d. Rami anterior descending branch of coronary artery was ligated for 30 min and then re-perfused for 120 min to establish a reperfusion model. Effects of TSA on the infarct area, creatine kinase (CK), aspartate aminotransferase (AST), high mobility group box B1 protein (HMGB1), and inflammation and oxidation were investigated.

RESULTS

Compared with those in the IR group, infarct size percentages of rats' myocardium in L-TSA, M-TSA, and H-TSA groups were reduced by 1.21, 4.26, and 12.50%, respectively, CK activities by 7.4, 11.2, and 12.5%, respectively, and AST activities also declined (p < 0.05). Furthermore, compared with those in the IR group, SOD and GSH-Px activities increased, and MDA, TNF-α, IL-6, and iNOS levels decreased in L-TSA, M-TSA, and H-TSA groups (p < 0.05). Meanwhile, compared with those in the IR group, HMGB1 expressions in L-TSA, M-TSA, and H-TSA groups were lowered by 21.9, 32.4, and 35.6%, respectively.

DISCUSSION AND CONCLUSION

The protective function of TSA on myocardial ischemia reperfusion injury may be possibly exerted by inhibiting the increase of ROS caused by the reperfusion to attenuate the expression of HMGB1 and inhibit inflammation.

Polymorphism of klotho G-395A and susceptibility of coronary artery disease in East-Asia population: a meta-analysis

OBJECTIVE

To investigate the association between polymorphism of Klotho G-395A and susceptibility of coronary artery disease (CAD) in East-Asia population.

METHODS

A total of 6 case-control studies involving 1560 patients and 1459 controls were analyzed in the study. PubMed, Embase, CBM disc, Wanfang database were searched for published case-control studies investigating the association between Klotho G-395A and CAD that were available before Dec. 2013. Fixed or random effect models were selected for odds ratio (OR) calculation. A Meta-analysis was performed to estimate heterogeneity and the pooled odds ratio (OR) to evaluate the relationship between Klotho G-395A polymorphism and CAD. The sensitivity analysis was also assessed.

RESULTS

There was no significant heterogeneity found (dominant genetic model: P = 0.2, I(2) = 30.8%). The pooled OR (95% CI) value of the frequencies of the Klotho G-395A genotype (GA + AA)/GG calculated by fixed effects mode was 1.24 (95% CI:1.06-1.45), P = 0.009. There was no significant heterogeneity among the remaining articles after using random effect model or excluding the article with the largest weight or the article with larger frequencies of the allele A, respectively. And the pooled OR (95% CI) value of the frequencies of the genotype (GA + AA)/GG were similar. Publication bias was not found by Begg's test.

CONCLUSION

Klotho G-395A polymorphism may be a susceptible factor of CAD in East-Asia population.

A feedback regulatory loop between HIF-1α and miR-21 in response to hypoxia in cardiomyocytes

Accumulating evidence suggests that hypoxia-inducible factor 1α (HIF-1α) regulates numerous miRNAs and is crucial for cellular response to hypoxia. However, the relationship between HIF-1α and miR-21 in hypoxic cardiomyocytes is little known. We found that hypoxia induced HIF-1α and miR-21 expression. HIF-1α knockdown increased cell apoptosis and reduced miR-21 expression. Furthermore, we found that HIF-1α transcriptionally enhanced miR-21 promoter activity by binding to its promoter, which required the recruitment of CBP/p300. In addition, we found that miR-21 inhibition increased cell apoptosis and reduced HIF-1α expression, and modulated the PTEN/Akt pathway. Our results indicate that HIF-1α-miR-21 feedback contributes to the adaptation of cardiomyocytes to hypoxia, and has potential as therapeutic target for myocardial ischemia.

Rice dehydrin K-segments have in vitro antibacterial activity

Dehydrins are groups of plant proteins that have been shown to response to various environmental stimuli such as dehydration, elevated salinity, and low temperature. However, their roles in plant defense against microbes have not been demonstrated. In an attempt to discover plant antimicrobial proteins, we have screened a rice cDNA library and isolated several cDNAs coding for dehydrins. Protein extracts from Escherichia coli expressing these cDNAs were tested for their activity against Gram-positive bacteria (Bacillus pumilus, B. subtilis, Staphylococcus aureus, and Sarcina lutea) and Gram-negative bacteria (Escherichia coli and Xanthomonas oryzae pv. oryzae). The results indicate that the crude protein extracts exhibited antibacterial activities against the Gram-positive bacteria. However, dehydrins purified by immunoaffinity chromatography were not active against the bacteria. To pinpoint the dehydrin peptides that were responsible for the bactericidal activity, we expressed DNA sequences coding for truncated dehydrins containing either K- or S-segment and found that K-segment peptides, and not S-segment, were responsible for the antibacterial activities against Gram-positive bacteria. Antibacterial assay with synthetic K-segments indicated that the peptides inhibited growth of B. pumilus with minimum inhibition concentration and minimum bactericidal concentration of 130 and 400 μg/ml, respectively.

Peritoneal macrophage and blood monocyte functions after open and laparoscopic-assisted cecectomy in rats

BACKGROUND

It has been well established that open abdominal surgery results in systemic immunosuppression postoperatively; in contrast, laparoscopic surgery is associated with significantly better preserved systemic immune function. However, when intraperitoneal (local) immune function is considered, laparoscopic procedures done under a CO2 pneumoperitoneum (pneumo) have been shown to result in greater immunosuppression compared to that of open surgery. Few studies have simultaneously assessed systemic and local immune function. The purpose of this study was to assess peripheral blood mononuclear cell (PBMC) and peritoneal macrophage tumor necrosis factor-alpha (TNF-alpha) levels, H2O2 production, and MHC class II antigen expression after open and laparoscopically assisted cecectomy in a rat model.

METHODS

A total of 75 Sprague Dawley rats were used for three separate experiments. For each study, rats were randomly divided into three groups: anesthesia alone (AC), laparoscopic-assisted cecectomy (LC), and open cecectomy via full laparotomy (OP). A CO2 pneumo was used for laparoscopic operations. On postoperative day 1 the animals were sacrificed, macrophages were harvested via intraperitoneal lavage, and PBMCs were isolated from whole blood obtained by cardiac puncture. In experiment 1, macrophages and PBMC from each animal were stimulated with lipopolysaccharide, after which TNF-alpha levels of the supernatant were determined. In experiment 2, after stimulation with PMA, H2O2 release was assessed by measuring fluorescence. In experiment 3, via flow cytometry, the number of cells with surface MHC class II proteins were determined. Data from the three groups in each experiment were compared using analysis of variance Tukey-Kramer tests.

RESULTS

Macrophages and PBMC from rats in the OP group released significantly more TNF-alpha than cells from rats in the LC ( p < 0.05) or AC ( p < 0.05) groups. Macrophages from rats in the OP group released significantly less H2O2 than cells from the AC ( p < 0.01) and LC ( p < 0.05) groups. There was no difference between the AC and LC results. No significant differences in PBMC H2O2 release were noted among any of the groups. OP group macrophages expressed significantly less MHC class II antigen than did AC group macrophages ( p < 0.05). No differences were noted among the LC results and either the OP or AC group's outcomes. No differences were noted in PBMC MHC class II expression among any of the groups.

CONCLUSIONS

In all instances, the LC group's macrophage results were similar to the AC group's results. OC group macrophages produced significantly more TNF-alpha and less H2O2 than both the AC and LC groups. MHC class II protein expression was less for the OC group than for the AC group. OC group PBMCs produced more TNF-alpha. No differences in PBMC H2O2 release or MHC class II expression were noted. Laparoscopic methods better preserves the baseline values of the parameters studied.

Increased platelet-derived growth factor (PDGF) release after laparotomy stimulates systemic tumor growth in mice

BACKGROUND

Our laboratory has demonstrated that tumors grow larger and are more easily established following laparotomy than after carbon dioxide (CO2) pneumoperitoneum or anesthesia alone. We have also shown that tumor cells incubated with serum from laparotomized mice proliferated significantly faster in vitro than those incubated with plasma from mice that underwent laparoscopy or anesthesia alone. We hypothesized that differing levels of a plasma-soluble growth factor(s) postoperatively causes tumors to proliferate faster after laparotomy. This study's purpose was to isolate and characterize the plasma growth factor(s) responsible for the increased growth of systemic tumors after laparotomy.

METHODS

Female Balb/C mice (n = 100) were randomized to two groups: anesthesia control (AC) or midline sham laparotomy (4 cm) (Open). Plasma was collected on Postoperative day 4. For the tumor proliferation assay, C-26 colon cancer cells were incubated in media with either 10% AC or Open "raw" plasma (not passed through column), or AC or Open plasma that had been passed through the column. For elution of heparin-binding proteins, plasma from each group was passed through a heparin-sepharose column. Elution of bound proteins was accomplished with a 0.1-2 M NaCl gradient. Each fraction was examined for protein content. For the anti-platelet-derived growth factor (PDGF) neutralizing antibody study, C-26 cells were incubated with one of four plasma preparations: AC or Open plasma alone, or AC or Open plasma incubated with anti-PDGF antibody. For both studies, tumor proliferation was determined after 2 days with an MTS/PMS assay. Results from each group were compared and differences determined using analysis of variance (ANOVA) and Tukey-Kramer tests.

RESULTS

On heparin chromatography, a single elution peak consistent with PDGF was present in both AC and Open plasma and was 1.5 times greater in the Open plasma. The first tumor proliferation assay showed that tumor cells incubated with Open plasma proliferated 2.5 times faster than those with AC plasma (p < 0.0001). Passage of AC plasma through the column did not alter its mitogenic activity, but Open plasma thus treated demonstrated significantly decreased mitogenic activity. The second tumor proliferation assay showed that anti-PDGF antibody had no effect on the mitogenic activity of the AC plasma but decreased the mitogenic activity of the Open plasma to the AC plasma level.

CONCLUSIONS

Laparotomy is associated with higher levels of a heparin-binding plasma factor, consistent with PDGF. The enhanced mitogenic activity of the OP plasma was neutralized with anti-PDGF antibody. Increased plasma levels of PDGF after laparotomy may be responsible for accelerated tumor growth following laparotomy in mice.

[An experimental study on subconjunctival interleukin-1 receptor antagonist for promotion of corneal transplant survival]

OBJECTIVE

To determine whether the subconjunctival application of interleukin-1 receptor antagonist (IL-1ra) can prolong the corneal graft survival in the rat model of orthotopic penetrating keratoplasty.

METHODS

For all experiments, F344 corneas were transplanted into LOU (major histocompatibility-disparate) eyes. Experimental groups received subconjunctival injection of 50, 100 and 200 microg IL-1ra respectively, and the control group received the same volume of 0.9% normal saline instead for consecutive 2 weeks. All transplants were evaluated for 4 weeks after surgery for signs of rejection.

RESULTS

The mean survival time (MST) of the grafts of the experimental groups was increased significantly (t = 0.00, P < 0.01) in comparison with the control group. The MST of the IL-1ra 200 microg group was increased significantly than that of the IL-1ra 50 microg group (t = 0.00, P < 0.01). Furthermore, the IL-1ra-treated grafts had significantly less corneal inflammation, infiltration, lower levels of opacity, edema, neovascularization and rejection index compared with the control group.

CONCLUSIONS

Subconjunctival treatment of IL-1ra has a significantly positive effect on promoting corneal allograft survival. And its effect is dosage-dependent.

[Efficacy of topical cyclosporine A on keratoplasty rejection in rats]

OBJECTIVE

To evaluate the efficacy of topical cyclosporine A (CsA) on a penetrating keratoplasty rejection model in rats.

METHODS

Lou rats received orthotopic corneal allografts from inbred F344 donors. The rats were treated with one drop of topical solution four times daily for 30 days. Sixty rats were divided into one control (the matrix of CsA solution) and five treatment groups (0.5%, 1.0%, 2.0% CsA, glucocorticoid, glucocorticoid and 1.0% CsA). Rejection index (RI) and mean survival time (MST) were calculated, and histopathological and immunohistopathological examination were performed for each group.

RESULTS

The graft MST was postponed by topical CsA treatment. There was significant difference between each treatment group and the control group (t greater-than-or-equal 2.28, P < 0.0l), especially 2% CsA, steroid and combined 1% CsA and steroid groups, the combined group being the most effective. The RI was lower in all the groups with topical CsA than that in the control group (P < 0.01). The effect of 2% CsA was the same as that of the steroid, while 1% CsA combined steroid was the most effective. The histopathological findings confirmed that the topical application of CsA reduced the inflammatory cells infiltrating the graft stroma and the neovascularization. Immunohistopathological analysis demonstrated that there were fewer CD(+)(11a) T cells and macrophages in the infiltration and intercellular adhesion molecule (ICAM)-1 positive cells in keratocytes and endothelium of grafts in the treatment groups than in the control group.

CONCLUSIONS

Topical CsA can inhibit the keratoplasty rejection episodes in the rat and afford better results when combined with topical steroid.

[Study on nutrition composition and protein quality of a Chinese wild rice]

In order to exploit and develop the resource of a kind of Chinese wild rice[Zinania Lalifolia (Griseb) Turcz], the nutrition values of the Chinese wild rice from Luoma, Baoying, Hongze, Weishan and Tai lake were analyzed. The nutrients of Chinese wild rice per 100 g samples were protein 13.2 g, vitamin B1 0.59 mg, vitamin B2 0.07 mg, vitamin E 0.29 mg, zinc 1.60 mg, iron 2.69 mg, and they were higher than those of white rice. The amino acid score of Chinese wild rice was 84, the first limiting amino acid was threonine, and the protein efficiency ratio(PER) was 2.75. These data showed that the Chinese wild rice was a good food resource with higher nutrition value, therefore, the ancient and novel food resource might be used in Chinese diet as the North American wild rice that was used in American diet.

Delayed-type hypersensitivity response is better preserved in mice following insufflation than after laparotomy

BACKGROUND

Our laboratory has previously used pig and rat models to demonstrate that delayed-type hypersensitivity (DTH) response to an antigen challenge is suppressed following laparotomy compared to insufflation. The purpose of this study was to develop a practical and reliable mouse DTH model that could be used in future studies to test immunomodulating drugs and therapies.

METHODS

Female C3H/HeN mice (n = 100) were given three serial DTH challenges of 25 microl of 4 mg/ml phytohemagglutinin (PHA) 12 days before the test procedure, immediately following the test procedure, and on the 2nd postoperative day. All challenges were administered via subcutaneous injection in alternating footpads. The thickness of the footpad was determined with electronic calipers immediately prior to injection and 24 h following injection in a blinded fashion. The difference in thickness represents the response. On the day of the procedure, mice were randomized into the following three groups: (a) control (AC), (b) insufflation (INS), and (c) open (OPEN). AC mice underwent no procedure. INS mice underwent CO(2) insufflation at 2-4 mmHg for 20 min. OPEN mice underwent a midline incision from xiphoid to pubis that was closed after 20 min. Data were analyzed using ANOVA and Tukey-Kramer tests to determine differences between groups.

RESULTS

Preoperatively, there were no significant differences among the three groups. On POD1, the OPEN group had significantly less response than both the AC and INS groups. On POD3, there were significant differences between the OPEN group and both the INS and AC groups. There was no significant difference between the AC and INS group at any time.

CONCLUSIONS

In conclusion, a DTH mouse model has been established that allows serial assessment of cell-mediated immune function. This model can be used to study immune function after open and minimal access procedures in a simple and cost-effective manner.

Tissue factor transcription driven by Egr-1 is a critical mechanism of murine pulmonary fibrin deposition in hypoxia

Local hypoxemia and stasis trigger thrombosis. We have demonstrated previously that in a murine model of normobaric hypoxia pulmonary fibrin deposition is a result of expression of tissue factor, especially in oxygen-deprived mononuclear phagocytes (MPs). We now show that transcription factor early-growth-response gene product (Egr-1) is rapidly activated in hypoxia, both in vitro and in vivo, and is responsible for transcription and expression of tissue factor in hypoxic lung. MPs and HeLa cells subjected to hypoxia (pO2 approximately 13 torr) had increased levels of tissue factor transcripts (approximately 18-fold) and an increased rate of transcription (approximately 15-fold), based on nuclear run-on analysis. Gel-shift analysis of nuclear extracts from hypoxic MPs and HeLa cells demonstrated increased DNA-binding activity at the serum response region (SRR; -111/+14 bp) of the tissue factor promoter at Egr-1 motifs. Using 32P-labeled Egr consensus oligonucleotide, we observed induction of DNA-binding activity in nuclear extracts from hypoxic lung and HeLa cells because of activation of Egr-1, by means of supershift analysis. Transient transfection of HeLa cells with chimeric plasmids containing wild-type or mutant SRR from the tissue factor promoter showed that intact Sp1 sites are necessary for basal promoter activity, whereas the integrity of Egr-1 sites was required for hypoxia-enhanced expression. A central role for Egr-1 in hypoxia-mediated tissue factor expression was confirmed by experiments with homozygous Egr-1 null mice; wild-type mice subjected to oxygen deprivation expressed tissue factor and showed fibrin deposition, but hypoxic homozygous Egr-1 null mice displayed neither tissue factor nor fibrin. These data delineate a novel biology for hypoxia-induced fibrin deposition, in which oxygen deprivation-induced activation of Egr-1, resulting in expression of tissue factor, has an unexpected and central role.

[p53 gene mutations in BALB/c 3T3 cells transformed by crocidolite]

This study sought to address the relationship between crocidolite and p53 gene mutation. The mutations of p53 gene in 8 BALB/c 3T3 cell lines transformed by crocidolite were analysed. Altogether 11 exons of the gene from 8 cell lines were detected by PCR-SSCP. 7 alterations were found; 2 of them were located in exon 4-6, and 5 in 9-11. Most of the mutations (5/7) were of one more band than that of wild cell from SSCP, and alterations were randomly scattered among the crocidolite doses groups. The results suggest that the presence of a p53 alteration is not related to the dose of crocidolite used. Besides, p53 mutation may occur in a relatively later period of the growth of the transformed cell lines. The results also showed that the mutations occurred predominantly in exons 9-11. This was different from that seen in human mesothelioma where mutations in the exon 5-8 of p53 gene were more frequently observed.