Inhibition of endothelial Nox2 activation by LMH001 protects mice from angiotensin II-induced vascular oxidative stress, hypertension and aortic aneurysm

Endothelial oxidative stress and inflammation attributable to the activation of a Nox2-NADPH oxidase are key features of many cardiovascular diseases. Here, we report a novel small chemical compound (LMH001, MW = 290.079), by blocking phosphorylated p47^phox interaction with p22^phox, inhibited effectively angiotensin II (AngII)-induced endothelial Nox2 activation and superoxide production at a small dose (IC50 = 0.25 μM) without effect on peripheral leucocyte oxidative response to pathogens. The therapeutic potential of LMH001 was tested using a mouse model (C57BL/6J, 7-month-old) of AngII infusion (0.8 mg/kg/d, 14 days)-induced vascular oxidative stress, hypertension and aortic aneurysm. Age-matched littermates of p47^phox knockout mice were used as controls of Nox2 inhibition. LMH001 (2.5 mg/kg/d, ip. once) showed no effect on control mice, but inhibited completely AngII infusion-induced excess ROS production in vital organs, hypertension, aortic walls inflammation and reduced incidences of aortic aneurysm. LMH001 effects on reducing vascular oxidative stress was due to its inhibition of Nox2 activation and was abrogated by knockout of p47^phox. LMH001 has the potential to be developed as a novel drug candidate to treat oxidative stress-related cardiovascular diseases.

p47phox-Dependent Oxidant Signalling through ASK1, MKK3/6 and MAPKs in Angiotensin II-Induced Cardiac Hypertrophy and Apoptosis

The p47phox is a key regulatory subunit of Nox2-containing NADPH oxidase (Nox2) that by generating reactive oxygen species (ROS) plays an important role in Angiotensin II (AngII)-induced cardiac hypertrophy and heart failure. However, the signalling pathways of p47phox in the heart remains unclear. In this study, we used wild-type (WT) and p47phox knockout (KO) mice (C57BL/6, male, 7-month-old, n = 9) to investigate p47phox-dependent oxidant-signalling in AngII infusion (0.8 mg/kg/day, 14 days)-induced cardiac hypertrophy and cardiomyocyte apoptosis. AngII infusion resulted in remarkable high blood pressure and cardiac hypertrophy in WT mice. However, these AngII-induced pathological changes were significantly reduced in p47phox KO mice. In WT hearts, AngII infusion increased significantly the levels of superoxide production, the expressions of Nox subunits, the expression of PKCα and C-Src and the activation of ASK1 (apoptosis signal-regulating kinase 1), MKK3/6, ERK1/2, p38 MAPK and JNK signalling pathways together with an elevated expression of apoptotic markers, i.e., γH2AX and p53 in the cardiomyocytes. However, in the absence of p47phox, although PKCα expression was increased in the hearts after AngII infusion, there was no significant activation of ASK1, MKK3/6 and MAPKs signalling pathways and no increase in apoptosis biomarker expression in cardiomyocytes. In conclusion, p47phox-dependent redox-signalling through ASK1, MKK3/6 and MAPKs plays a crucial role in AngII-induced cardiac hypertrophy and cardiomyocyte apoptosis.

Breaking the deadlock of calcified coronary artery lesions: A contemporary review

Percutaneous coronary intervention (PCI) of severely calcified lesions is known to result in lower procedural success rates, higher complication rates, and worse long-term clinical outcomes compared to noncalcified lesions. Adequate lesion preparation through calcium modification is crucial in ensuring procedural success and reducing adverse cardiovascular outcomes. There are numerous calcium modification devices currently available whose usefulness depends on the nature of the calcific disease and its anatomical distribution. It can be challenging for the interventionists to decide which device is best suited for their patient. There is also emerging evidence for intravascular imaging in guiding selection of calcium modification devices using parameters such as calcium distribution and depth that directly impact on procedural success and clinical outcomes. In this review we aim to discuss the pathophysiology of coronary calcification, evaluate strategies and technologies of calcium modification and propose an A-M-A-S-A algorithm in managing calcified coronary lesions.

Exploration of Alcohol Consumption Behaviours and Health-Related Influencing Factors of Young Adults in the UK

Hazardous alcohol consumption is ranked above illicit drug use with regards to health deterioration and social and economic burden. This study sought to clarify the factors influencing alcohol consumption and its prevalence in young adults. Demographics, alcohol consumption and lifestyle information were gathered via anonymous questionnaires during 2011-2019, crossing Reading, Surrey and Farnborough universities, UK. Controlling for confounders, a multinomial logistic regression was performed using SAS® 9.4 software. A total of 1440 students (43.5% males, 56.5% females; 54.4% Caucasians) with a mean (SD) age of 19.9 (2.73) were included. Among them, 68.9% consumed alcohol frequently and 31.7% had ≥12 units/week. Statistical analysis revealed that males consumed twice more alcohol than females, odds ratio (OR) 1.67 (95% confidence interval (CI) = 1.34-2.09), p-value < 0.01. Caucasians consumed up to five times more alcohol than other ethnicities, OR 4.55 (3.57-5.56), p-value < 0.01. Smokers consumed three times more alcohol than non-smokers, OR 2.69 (1.82, 3.99), p-value < 0.01. In general, the levels of alcohol consumption were positively associated with the levels of physical activity, OR 2.00 (1.17-3.42), p-value < 0.05 and negatively associated with recreational sedentary screen-time activities in males, OR 0.31 (0.12-0.86), p-value = 0.03. Focusing alcohol interventions toward Caucasians, smokers and physically active students, particularly males, may guide university strategies to reduce alcohol-related societal harm and risks of morbidity and mortality.

In vivo and in silico characterization of apocynin in reducing organ oxidative stress: A pharmacokinetic and pharmacodynamic study

Apocynin has been widely used in vivo as a Nox2-contaninig nicotinamide adenine dinucleotide phosphate oxidase inhibitor. However, its time-dependent tissue distribution and inhibition on organ reactive oxygen species (ROS) production remained unclear. In this study, we examined apocynin pharmacokinetics and pharmacodynamics (PKPD) after intravenous (iv) injection (bolus, 5 mg/kg) of mice (CD1, 12-week). Apocynin was detected using a HPLC coupled to a linear ion-trap tandem mass spectrometer. Apocynin peak concentrations were detected in plasma at 1 minute (5494 ± 400 ng/mL) (t1/2  = 0.05 hours, clearance = 7.76 L/h/kg), in urine at 15 minutes (14 942 ± 5977 ng/mL), in liver at 5 minutes (2853 ± 35 ng/g), in heart at 5 minutes (3161 ± 309 ng/g) and in brain at 1 minute (4603 ± 208 ng/g) after iv injection. These were accompanied with reduction of ROS production in the liver, heart and brain homogenates. Diapocynin was not detected in these samples. Therapeutic effect of apocynin was examined using a mouse model (C57BL/6J) of high-fat diet (HFD, 16 weeks)-induced obesity and accelerated aging. Apocynin (5 mmol/L) was supplied in drinking water during the HFD period and was detected at the end of treatment in the brain (5369 ± 1612 ng/g), liver (4818 ± 1340 ng/g) and heart (1795 ± 1487 ng/g) along with significant reductions of ROS production in these organs. In conclusion, apocynin PKPD is characterized by a short half-life, rapid clearance, good distribution and inhibition of ROS production in major organs. Diapocynin is not a metabolite of apocynin in vivo. Apocynin crosses easily the blood-brain barrier and reduces brain oxidative stress associated with metabolic disorders and aging.

Impact of unhealthy lifestyle on cardiorespiratory fitness and heart rate recovery of medical science students

Background

Medical science students represent valuable labour resources for better future medicine and medical technology. However, little attention was given to the health and well-being of these early career medical science professionals. The aim of this study is to investigate the impact of lifestyle components on cardiorespiratory fitness and heart rate recovery measured after moderate exercise in this population.

Methods

Volunteers without documented medical condition were recruited randomly and continuously from the first-year medical science students during 2011–2014 at the University of Surrey, UK. Demographics and lifestyle components (the levels of smoking, alcohol intake, exercise, weekend outdoor activity and screen-time, daily sleep period, and self-assessment of fitness) were gathered through pre-exercise questionnaire. Cardiorespiratory fitness (VO₂max) and heart rate recovery were determined using Åstrand–Rhyming submaximal cycle ergometry test. Data were analysed using SPSS version 25.

Results

Among 614 volunteers, 124 had completed both lifestyle questionnaire and the fitness test and were included for this study. Within 124 participants (20.6 ± 4 years), 46.8% were male and 53.2% were female, 11.3% were overweight and 8.9% were underweight, 8.9% were current smokers and 33.1% consumed alcohol beyond the UK recommendation. There were 34.7% of participants admitted to have < 3 h/week of moderate physical activity assessed according to UK Government National Physical Activity Guidelines and physically not fit (feeling tiredness). Fitness test showed that VO₂max distribution was inversely associated with heart rate recovery at 3 min and both values were significantly correlated with the levels of exercise, self-assessed fitness and BMI. Participants who had < 3 h/week exercise, or felt not fit or were overweight had significantly lower VO₂max and heart rate recovery than their peers.

Conclusion

One in three new medical science students were physically inactive along with compromised cardiorespiratory fitness and heart rate recovery, which put them at risk of cardiometabolic diseases. Promoting healthy lifestyle at the beginning of career is crucial in keeping medical science professionals healthy.

[Application of MRI in the diagnosis of cervical cancer]

Objective: Investigating the diagnostic value of MRI for cervical cancer, including preoperative staging, vagina involvement and lymph node metastasis is the aim of this pape. Methods: Select 116 patients with UCC of the second hospital of JiLin University from October 2016 to April 2019. All patients accept MRI examination. Ultimately, all patients accept surgical treatment. Use SPSS19.0 software to analyze MRI results of all the patients.Using the postoperative pathological results as the golden standard in the diagnosis of cervicalcancer diagnosis. The dates from the MRI preoperative staging, preoperative clinical staging and the postoperative pathologic staging were compared through chi-square test. And the dates of preoperative MRI in cervical cancer vagina involvement and lymph node metastasis diagnosis and postoperative pathological results were compared through Mcnemar chi-square test. The difference was statistically significant(P<0.05). Results: 1, The differences between MRI staging and the postoperative pathologic staging have no statistical significance (P>0.05), whilethe difference between MRI staging and preoperative clinical staging during was statistically significant (P<0.05). Using the postoperative pathological staging as the examination standards, the accuracy of preoperative clinical staging is only 67.5%, and cervical cancer overall preoperative MRI staging accuracy was 95%; 2, Preoperative MRI diagnosis and postoperative pathologic results in cervical vaginal involvement and lymph node metastasis has highsensitivity and specificity, were 97.0%, 96.2%, 93.2%, 97.8%. Checked by Mcnemar chi-square test, the differences between themhave no statisticalsignificance (P>0.05), namely the preoperative MRI diagnosis and postoperative pathological results have consistency in clinical. Conclusion: The combination of MRI and FIGO clinical stage can impro the accuracy of clinical staging of cervical cancer. MRI can be used as the important tool to assess cervical cancer preoperative staging, and to choose and formulate reasonable cervical cancer treatment plan.

A novel machine learning-derived radiotranscriptomic signature of perivascular fat improves cardiac risk prediction using coronary CT angiography

BACKGROUND

Coronary inflammation induces dynamic changes in the balance between water and lipid content in perivascular adipose tissue (PVAT), as captured by perivascular Fat Attenuation Index (FAI) in standard coronary CT angiography (CCTA). However, inflammation is not the only process involved in atherogenesis and we hypothesized that additional radiomic signatures of adverse fibrotic and microvascular PVAT remodelling, may further improve cardiac risk prediction.

METHODS AND RESULTS

We present a new artificial intelligence-powered method to predict cardiac risk by analysing the radiomic profile of coronary PVAT, developed and validated in patient cohorts acquired in three different studies. In Study 1, adipose tissue biopsies were obtained from 167 patients undergoing cardiac surgery, and the expression of genes representing inflammation, fibrosis and vascularity was linked with the radiomic features extracted from tissue CT images. Adipose tissue wavelet-transformed mean attenuation (captured by FAI) was the most sensitive radiomic feature in describing tissue inflammation (TNFA expression), while features of radiomic texture were related to adipose tissue fibrosis (COL1A1 expression) and vascularity (CD31 expression). In Study 2, we analysed 1391 coronary PVAT radiomic features in 101 patients who experienced major adverse cardiac events (MACE) within 5 years of having a CCTA and 101 matched controls, training and validating a machine learning (random forest) algorithm (fat radiomic profile, FRP) to discriminate cases from controls (C-statistic 0.77 [95%CI: 0.62-0.93] in the external validation set). The coronary FRP signature was then tested in 1575 consecutive eligible participants in the SCOT-HEART trial, where it significantly improved MACE prediction beyond traditional risk stratification that included risk factors, coronary calcium score, coronary stenosis, and high-risk plaque features on CCTA (Δ[C-statistic] = 0.126, P < 0.001). In Study 3, FRP was significantly higher in 44 patients presenting with acute myocardial infarction compared with 44 matched controls, but unlike FAI, remained unchanged 6 months after the index event, confirming that FRP detects persistent PVAT changes not captured by FAI.

CONCLUSION

The CCTA-based radiomic profiling of coronary artery PVAT detects perivascular structural remodelling associated with coronary artery disease, beyond inflammation. A new artificial intelligence (AI)-powered imaging biomarker (FRP) leads to a striking improvement of cardiac risk prediction over and above the current state-of-the-art.

Nox2 contributes to age-related oxidative damage to neurons and the cerebral vasculature

Oxidative stress plays an important role in aging-related neurodegeneration. This study used littermates of WT and Nox2-knockout (Nox2KO) mice plus endothelial cell–specific human Nox2 overexpression–transgenic (HuNox2Tg) mice to investigate Nox2-derived ROS in brain aging. Compared with young WT mice (3–4 months), aging WT mice (20–22 months) had obvious metabolic disorders and loss of locomotor activity. Aging WT brains had high levels of angiotensin II (Ang II) and ROS production; activation of ERK1/2, p53, and γH2AX; and losses of capillaries and neurons. However, these abnormalities were markedly reduced in aging Nox2KO brains. HuNox2Tg brains at middle age (11–12 months) already had high levels of ROS production and activation of stress signaling pathways similar to those found in aging WT brains. The mechanism of Ang II–induced endothelial Nox2 activation in capillary damage was examined using primary brain microvascular endothelial cells. The clinical significance of Nox2-derived ROS in aging-related loss of cerebral capillaries and neurons was investigated using postmortem midbrain tissues of young (25–38 years) and elderly (61–85 years) adults. In conclusion, Nox2 activation is an important mechanism in aging-related cerebral capillary rarefaction and reduced brain function, with the possibility of a key role for endothelial cells.

[Relationship between the choroid plexus cyst and the aneuploidy]

Objective: Using the method of the ultrasound and the noninvasive DNA to find the relationship between the choroid plexus cyst and the aneuploidy, and to provide the meaningful data for prenatal consultant. Methods: A total of 112 cases, that the gestational age were between 13 and 20 weeks, which were diagnosed with choroid plexus cyst in the Department of Gynecology and Obstetrics of the Second Hospital of Jilin University from January. 2016 to July. 2017 were tested by ultrasonography. They all accepted the noninvasive DNA. At the same time, a total of 100 normal fetuses were randomly involved in the control group by the combination of gestational age and the age of the pregnant woman, all of them had taken the non-invasive DNA examination and followed up until the birth. Those fetuses who combined with other malformations were induced labor in the two groups. If the results of noninvasive DNA indicated the high-risk, invasive examination for karyotype analysis were recommended. If the results were aneuploidy, they chose induced labor. The rest cases followed up until the birth. Results: Five cases of the 112 fetuses in the case group were found with obvious malformation (3 of them were found in the early trimester, 2 of them were found in the middle trimester). The numbers of high risk results of noninvasive DNA were 7, and 5 of them underwent the invasive karyotype analysis. When the aneuploidy had diagnosed definitely, induced labor had been taken. One case was found to be the aneuploidy in the control group, and took the induced labor. One case was diagnosed as right side aortic arch by ultrasound in the control group, with a good prognosis. The other cases were followed up until the birth with a good prognosis. Conclusions: (1)In the early trimester, the fetus with choroid plexus cyst has an increasing risk of aneuploidy. (2)When the maximum diameter of choroid plexus cyst is less than 1 cm and the cyst was single, most of them could disappear in the middle trimester, it has no effect on the fetus. (3)Noninvasive DNA test has a high accuracy, which can improve the positive rate of invasive examination.

[Correlation between fetal intracardiac echogenic foci and chromosome and heart function]

Objective: To study the relationship between the intracardiac echogenic foci and the abnormal chromosome and the changes of Cardiac function. Methods: A total of 2645 cases with the gestational age between 14 to 22 weeks were tested in the department of gynecology and obstetrics of the Second Hospital of Jilin University from Jan.2016 to Dec.2017.Seventy-nine of them existed the intracardiac echogenic foci, and the patient's imaging data in details were recorded.All of them have taken the non-invasive DNA examination.Fetal echocardiography was performed at 22-24 weeks.Karyotype analysis was performed using amniocentesis and umbilical cord blood puncture.Inducing labor was performed for fetuses that has been identified as a haploid or had a severely malformation during pregnancy.The other fetuses were followed up to the birth.Echocardiography was performed on neonates. Results: The detection rate of intracardiac echogenic focus was 3.0% in early pregnancy, 92% in the left ventricle, 4% in the right ventricle, and 4% in double ventricle.There were 5 cases of haploid fetus induced labor, 2 cases of induced labor due to fatal malformation.Fetal echocardiography revealed tricuspid regurgitation in 7 cases.One of them was induced labor in consideration of heart failure. Conclusions: 1.The risk of chromosomal abnormality in the fetus of isolated left intracardiac echogenic focus is lower.Non-invasive DNA examination has a high reliability that could be an important reference before an invasive antenatal diagnosis.2.A higher rate of fetal malformation will be found when the foci located in the right or double ventricle.3.The relationship between fetal intracardiac echogenic foci and fetal cardiac dysfunction needs to be further clarified.

[Relationship between sonographic markers and fetal chromosome abnormality during 16-18 weeks of pregnancy]

Objective: To analysis of fetal ultrasound soft index positive cases during 16-18 weeks of pregnancy, and to explore the relationship with chromosomal abnormalities in order to increase the positive rate of invasive prenatal diagnosis and reduce the rate of missed diagnosis. Methods: A total of 569 cases which were diagnosed with positive soft markers in the department of gynecology and obstetrics of the Second Hospital of Jilin University from Jan.2016 to Jan.2017 were studied by ultrasonography. Twenty-five cases were lost in follow-up and finally 544 cases were included as group A. Those fetuses who combined with other malformations were induced labor. Non-invasive DNA examination was recommended for continued pregnant women, and those pregnant women whose results were high risk underwent the amniotic cavity puncture. When the fetal aneuploidy was confirmed, they chose induced labor. We followed the rest of those patients until postnatal half year. Randomly selected 544 cases during 16-18 weeks of pregnancy without obvious abnormalities into group B, followed up to half a year after birth. Results: In group A, 7 of the 544 cases were combined with other severe malformation in the beginning, among the remaining 537 patients, 273 of them received non-invasive DNA examination. Ten cases were high risk results, all of them underwent the amniotic cavity puncture with the result of chromosome abnormality, and they chose induced labor. Six cases were found other malformation in the second trimester who chose induced labor, and the rest 521 cases followed until the fetuses was born after half year had a favorable prognosis. In group B, 1 cases of severe deformities and 1 cases of haploid fetuses were found in 544 fetuses. The incidence of haploid fetus in group A and group B were 1.8% and 0.2%, respectively, with statistically significant (P<0.05). The incidence of severe malformation in group A and group B were 2.3% and 0.2%, respectively, with statistically significant (P<0.05). Conclusions: During 16-18 weeks of pregnancy, sonographic markers may indicate an increased risk in fetal chromosomal abnormalities. The risk of serious malformation was increased in the fetuses with ultrasonic soft marker positive, but there was no specificity.

[Evaluation of pelvic floor function of postpartum pelvic floor ultrasound in pregnant women with multiple pregnancies]

Objective: To probe the effect of multiple pregnancy on pelvic floor function of pregnant women, Pelvic floor ultrasonography was performed on the 42 day postpartum women.And the bladder neck mobility, bladder and urethral posterior angle and pelvic diaphragmatic hiatus area were measured. Methods: Collect 200 cases 42 day postpartum women who visited the second hospital of Jilin University from July 2015 to June 2017, of which 100 cases of primipara belong to group A, 100 cases of multiple pregnancy belong to group B, and 100 cases without maternal at the same age belong to the control group, ultrasound measurement of the bladder neck mobility, bladder and urethral posterior angle and pelvic diaphragmatic hiatus area were measured.t test were proformed respectively between the three groups, P<0.05 was considered statistically significant difference. Results: In the control group, the bladder neck mobility is (2.59±0.51) cm , the bladder neck mobility in A group is (2.99±0.69) cm, the bladder neck mobility in B group is (3.36±0.71) cm; the bladder and urethral posterior angle in the control group is (112.56±13.61)°, the bladder and urethral posterior angle in the control group after Valsalva action angle is(135.37±12.17)°, the bladder and urethral posterior angle in A group is(119.26±15.80)°, the bladder and urethral posterior angle in group A after Valsalva action is(141.79±12.08)°, the bladder and urethral posterior angle in B group is(123.62±16.20)°, the bladder and urethral posterior angle in group B after Valsalva action is (148.92±13.60)°; the pelvic diaphragmatic hiatus area in the control group is (13.35±2.86) cm(2,) the pelvic diaphragmatic hiatus area in the control group after Valsalva action is(15.28±3.15) cm(2,) the pelvic diaphragmatic hiatus area in A group is(17.52±3.19) cm(2,) the pelvic diaphragmatic hiatus area in A group ater Valsalva action is (18.06±5.13_the pelvic diaphragmatic hiatus area) cm(2,) the pelvic diaphragmatic hiatus area in B group is (18.26±4.18) cm(2,) the pelvic diaphragmatic hiatus area in B group after Valsalva action is (20.3±3.53) cm(2).In group A, group B and the control group, the measured value of the bladder neck mobility, bladder and urethral posterior angle and pelvic diaphragmatic hiatus area were examined by t test, and P<0.05, which means the difference was statistically significant. Conclusion: Pregnancy can affect the function of female pelvic floor, and the effect of parturient is more significant than that of the primipara.

Aging-associated metabolic disorder induces Nox2 activation and oxidative damage of endothelial function

Oxidative stress attributable to the activation of a Nox2-containing NADPH oxidase is involved in the development of vascular diseases and in aging. However, the mechanism of Nox2 activation in normal aging remains unclear. In this study, we used age-matched wild-type (WT) and Nox2 knockout (KO) mice at 3-4 months (young); 11-12 months (middle-aged) and 21-22 months (aging) to investigate age-related metabolic disorders, Nox2 activation and endothelial dysfunction. Compared to young mice, middle-aged and aging WT mice had significant hyperglycaemia, hyperinsulinaemia, increased systemic oxidative stress and higher blood pressure. Endothelium-dependent vessel relaxation to acetylcholine was significantly impaired in WT aging aortas, and this was accompanied by increased Nox2 and ICAM-1 expressions, MAPK activation and decreased insulin receptor expression and signaling. However, these aging-associated disorders were significantly reduced or absent in Nox2KO aging mice. The effect of metabolic disorder on Nox2 activation and endothelial dysfunction was further confirmed using high-fat diet-induced obesity and insulin resistance in middle-aged WT mice treated with apocynin (a Nox2 inhibitor). In vitro experiments showed that in response to high glucose plus high insulin challenge, WT coronary microvascular endothelial cells increased significantly the levels of Nox2 expression, activation of stress signaling pathways and the cells were senescent, e.g. increased p53 and β-galactosidase activity. However, these changes were absent in Nox2KO cells. In conclusion, Nox2 activation in response to aging-associated hyperglycaemia and hyperinsulinaemia plays a key role in the oxidative damage of vascular function. Inhibition or knockout of Nox2 preserves endothelial function and improves global metabolism in old age.

Abstract 362: Knockout of NADPH Oxidase 2 Improves Global Metabolism and Endothelial Function in Aging Mice

Oxidative stress attributable to the activation of a Nox2-containing NADPH oxidase has been suggested to play a crucial role in the development of aging-associated vascular diseases. However, the mechanism of endothelial Nox2 activation in normal aging process remains unclear. In this study, we investigated the therapeutic potential of targeting Nox2 in improving global metabolism and endothelial function at old age by using age-matched wild-type and Nox2 knockout mice at 3-4 months (young); 11-12 months (middle aged) and 21-22 months (aging). Compared to young mice, middle-aged and ageing wild-type mice had significantly higher blood pressure, hyperglycaemia, hyperinsulinaemia. These were accompanied by oxidative stress in multiple organs including the lung, the liver, the heart and the vessels. The vessel motor function was examined in an organ bath using aortas isolated from these mice. Endothelium-dependent vessel relaxation to acetylcholine was significantly impaired in aortas of wild-type aging mice, and this was accompanied by increased expressions of Nox2 and markers of inflammation, activation of MAPK and Akt and decreased insulin receptor expression and function. However, these aging-associated disorders in aortas were significantly reduced by knocking out Nox2 in mice. In response to high glucose plus high insulin challenge, coronary microvascular endothelial cells isolated from wild-type mice displayed significantly increased Nox2 expression, oxidative stress and cell senescence, e.g. increased p53 expression and β-galactosidase activity. However, these responses were absent or significantly reduced in the endothelial cells isolated from Nox2 knockout mice. In conclusion, metabolic disorders in particular hyperglycaemia and insulin resistance play an important role in mediating Nox2 activation and oxidative stress in multiple organs in aging. Nox2 is involved in normal aging process-associated vascular inflammation and oxidative damage of endothelial dysfunction.

[The Study of relationship between fetal radius loss and chromosomal abnormality]

Objective: To explore the relationship between fetal radius loss and chromosomal abnormalities. Methods: Collect data of 3 100 cases pregnant women who had been checked in the second hospital of Jilin University from 2012 to 2015.There were 8 cases of absent radius, except 1 case of fetal lost follow-up, the remaining 7 cases had complete ultrasound, chromosome examination and the result of induction.The relationship between fetal radius loss and chromosomal abnormalities were analysed. Results: There were 1 case of 21 trisomy syndrome, 1 case of trisomy 13 syndrome, 2 cases of trisomy 18, 2 cases of chromosome translocation, 1 case of normal chromosome result and 1 case was lost to follow-up of the 8 absent radius fetuses. Conclusion: Through a comparison between the chromosome and ultrasonic characteristics of fetuses who have absent radius, we had indicated the relationship of fetal radius deletion and chromosomal anomaly, improved the positive rate of chromosome invasion examination, and provided the reference for eugenics.

[Prenatal ultrasound diagnosis, prognosis and chromosome analysis of fetal bowel dilatation]

Objective: To investigate the relationship among the prenatal ultrasound, prognosis and chromosome results of fetal bowel dilatation. And in order to further improve the positive rate of prenatal chromosome examination operation, and reduce the risk of missed diagnosis. Methods: Ninety fetuses who were diagnosed as fetal bowel dilatation by prenatal ultrasound from June 2013 to December 2015 in the Second hospital of Jilin University were enrolled. Chromosomes were examined by amniotic cavity puncture or umbilical cord blood puncture. The change of fetus's bowel was monitored periodically by prenatal ultrasound. The normal bowel movement of newborns was a good prognosis. The abdominal X ray or barium contrast radiography was performed in the newborns who did not have normal bowel movement after delivery. Patients underwent surgery or conservative treatment after diagnosis. Fetal karyotype analysis of aborted fetus was carried out by amniotic cavity puncture and umbilical cord blood before induction of labor. Autopsy was performed after induced labor. Patients who were not continued examination in our hospital were followed up by telephone. Results: Among the 90 fetuses, there are 11 cases of duodenum dilatation, 38 cases of jejunum and ileum dilatation, 41 cases of colorectal dilatation. Ten cases of duodenum dilatation were confirmed by autopsy after induced labor, and one case was lost in follow-up. Chromosome examination revealed 3 cases of 21- three body syndrome, 1 case of 18- three body syndrome, 1 case of chromosomal translocation. In 38 cases of jejunum and ileum dilatation, bowel dilatation of 26 cases had decrease or no obvious increase with good prognosis. Six cases of induced labor, 3 cases of receive surgery after birth, 2 cases of postoperative survival, and 3 cases of loss of follow-up. Chromosome examination revealed 1 case of 21- three body syndrome and 1 case of chromosomal translocation. In 41 cases of colorectal dilatation, 29 cases had good prognosis. Five cases were aborted, 1 case of fetal death, 2 cases died within 1 month after birth, 2 cases received surgery after birth and survived after operation, and 2 cases of loss of follow-up. Conclusions: Clinical prognosis and the associated risk of chromosome abnormalities in patients with fetal bowel dilatation are different in terms of its expansion location and extent of the different, which need to a specific analysis of specific situations.

Effect of polychlorinated biphenyls on oxidation stress in the liver of juvenile GIFT, Oreochromis niloticus

The present study clearly showed that chronic exposure to polychlorinated biphenyls (PCBs) at environmentally relevant concentrations can damage juvenile tilapia livers by modulating antioxidant enzyme activities and gene transcription, which affects toxic bioaccumulation and histological congestion. The results suggest that PCBs caused a decrease in the activity of some hepatic antioxidative and biotransformation enzymes (SOD, CAT, GST, T-GSH, and MDA) in tilapia at 7 days, as well as transcriptional changes (sod, cat, and gst). Except for some antioxidant parameters (T-GSH, GSH/GSSG, T-AOC, and MDA), significant declines and increases occurred at 14 and 21 days, respectively. Most of the antioxidant enzymatic signatures and genotoxicity significantly increased at 14 and 21 days. This study presented evidence that PCBs could result in hepatic toxicity through oxidative stress in the early growth stages of tilapia, and we speculated that oxidative stress plays an important role in embryonic developmental toxicity induced by PCBs.

p22phox C242T Single-Nucleotide Polymorphism Inhibits Inflammatory Oxidative Damage to Endothelial Cells and Vessels

BACKGROUND

The NADPH oxidase, by generating reactive oxygen species, is involved in the pathophysiology of many cardiovascular diseases and represents a therapeutic target for the development of novel drugs. A single-nucleotide polymorphism, C242T of the p22(phox) subunit of NADPH oxidase, has been reported to be negatively associated with coronary heart disease and may predict disease prevalence. However, the underlying mechanisms remain unknown.

METHODS AND RESULTS

With the use of computer molecular modeling, we discovered that C242T single-nucleotide polymorphism causes significant structural changes in the extracellular loop of p22(phox) and reduces its interaction stability with Nox2 subunit. Gene transfection of human pulmonary microvascular endothelial cells showed that C242T p22(phox) significantly reduced Nox2 expression but had no significant effect on basal endothelial O2 (.-) production or the expression of Nox1 and Nox4. When cells were stimulated with tumor necrosis factor-α (or high glucose), C242T p22(phox) significantly inhibited tumor necrosis factor-α-induced Nox2 maturation, O2 (.-) production, mitogen-activated protein kinases and nuclear factor κB activation, and inflammation (all P<0.05). These C242T effects were further confirmed using p22(phox) short-hairpin RNA-engineered HeLa cells and Nox2(-/-) coronary microvascular endothelial cells. Clinical significance was investigated by using saphenous vein segments from non-coronary heart disease subjects after phlebotomies. TT (C242T) allele was common (prevalence of ≈22%) and, in comparison with CC, veins bearing TT allele had significantly lower levels of Nox2 expression and O2 (.-) generation in response to high-glucose challenge.

CONCLUSIONS

C242T single-nucleotide polymorphism causes p22(phox) structural changes that inhibit endothelial Nox2 activation and oxidative response to tumor necrosis factor-α or high-glucose stimulation. C242T single-nucleotide polymorphism may represent a natural protective mechanism against inflammatory cardiovascular diseases.

[Security of hormone replacement therapy among postoperative patients with endometrial carcinoma: a Meta-analysis]

OBJECTIVE

To systematically evaluate the security of hormone replacement therapy (HRT) among postoperative patients with endometrial carcinoma (EC).

METHODS

A systematic review and Meta-analysis of studies on security of HRT among EC patients after operation was done by Revman 5.2 software. Studies were mainly searched from the CENTRAL, Medline, Embase, Ovid, Wanfang, CNKI databases.

RESULTS

A total of 7 studies with 2 038 stageⅠand stageⅡ endometrial carcinoma patients were included. The quality of 6 studies included were medium, and 1 study was high. The endometrial carcinoma patients on HRT did not have a statistically increased incidence in the EC recurrence (RR=0.69, 95%CI (0.42-1.15), P=0.16) and cancer-induced death (RR=0.55, 95%CI (0.25-1.21), P=0.14). Subgroup analysis for the start of HRT within 6 months from time of surgery group and only estrogen replacement therapy group found no statistical different in the risk of the EC recurrence and cancer-induced death, compared with control group. No statistically increased risk of the EC recurrence was observed for estrogen plus progestin replacement therapy group.

CONCLUSION

There is no statistical difference in the recurrence rate and cancer-induced death rate of EC whether the early stage postoperative patients used HRT or not.

Crucial roles of Nox2-derived oxidative stress in deteriorating the function of insulin receptors and endothelium in dietary obesity of middle-aged mice

BACKGROUND AND PURPOSE

Systemic oxidative stress associated with dietary calorie overload plays an important role in the deterioration of vascular function in middle-aged patients suffering from obesity and insulin resistance. However, effective therapy is still lacking.

EXPERIMENTAL APPROACH

In this study, we used a mouse model of middle-aged obesity to investigate the therapeutic potential of pharmaceutical inhibition (apocynin, 5 mM supplied in the drinking water) or knockout of Nox2, an enzyme generating reactive oxygen species (ROS), in high-fat diet (HFD)-induced obesity, oxidative stress, insulin resistance and endothelial dysfunction. Littermates of C57BL/6J wild-type (WT) and Nox2 knockout (KO) mice (7 months old) were fed with a HFD (45% kcal fat) or normal chow diet (NCD, 12% kcal fat) for 16 weeks and used at 11 months of age.

KEY RESULTS

Compared to NCD WT mice, HFD WT mice developed obesity, insulin resistance, dyslipidaemia and hypertension. Aortic vessels from these mice showed significantly increased Nox2 expression and ROS production, accompanied by significantly increased ERK1/2 activation, reduced insulin receptor expression, decreased Akt and eNOS phosphorylation and impaired endothelium-dependent vessel relaxation to acetylcholine. All these HFD-induced abnormalities (except the hyperinsulinaemia) were absent in apocynin-treated WT or Nox2 KO mice given the same HFD.

CONCLUSIONS AND IMPLICATIONS

In conclusion, Nox2-derived ROS played a key role in damaging insulin receptor and endothelial function in dietary obesity after middle-age. Targeting Nox2 could represent a valuable therapeutic strategy in the metabolic syndrome.

Molecular insights of p47phox phosphorylation dynamics in the regulation of NADPH oxidase activation and superoxide production

Phagocyte superoxide production by a multicomponent NADPH oxidase is important in host defense against microbial invasion. However inappropriate NADPH oxidase activation causes inflammation. Endothelial cells express NADPH oxidase and endothelial oxidative stress due to prolonged NADPH oxidase activation predisposes many diseases. Discovering the mechanism of NADPH oxidase activation is essential for developing novel treatment of these diseases. The p47^phox is a key regulatory subunit of NADPH oxidase; however, due to the lack of full protein structural information, the mechanistic insight of p47^phox phosphorylation in NADPH oxidase activation remains incomplete. Based on crystal structures of three functional domains, we generated a computational structural model of the full p47^phox protein. Using a combination of in silico phosphorylation, molecular dynamics simulation and protein/protein docking, we discovered that the C-terminal tail of p47^phox is critical for stabilizing its autoinhibited structure. Ser-379 phosphorylation disrupts H-bonds that link the C-terminal tail to the autoinhibitory region (AIR) and the tandem Src homology 3 (SH3) domains, allowing the AIR to undergo phosphorylation to expose the SH3 pocket for p22^phox binding. These findings were confirmed by site-directed mutagenesis and gene transfection of p47^phox−/− coronary microvascular cells. Compared with wild-type p47^phox cDNA transfected cells, the single mutation of S379A completely blocked p47^phox membrane translocation, binding to p22^phox and endothelial O₂^⨪ production in response to acute stimulation of PKC. p47^phox C-terminal tail plays a key role in stabilizing intramolecular interactions at rest. Ser-379 phosphorylation is a molecular switch which initiates p47^phox conformational changes and NADPH oxidase-dependent superoxide production by cells.

Endothelial cell-specific reactive oxygen species production increases susceptibility to aortic dissection

BACKGROUND

Increased production of reactive oxygen species (ROS) throughout the vascular wall is a feature of cardiovascular disease states, but therapeutic strategies remain limited by our incomplete understanding of the role and contribution of specific vascular cell ROS to disease pathogenesis. To investigate the specific role of endothelial cell (EC) ROS in the development of structural vascular disease, we generated a mouse model of endothelium-specific Nox2 overexpression and tested the susceptibility to aortic dissection after angiotensin II (Ang II) infusion.

METHODS AND RESULTS

A specific increase in endothelial ROS production in Nox2 transgenic mice was sufficient to cause Ang II-mediated aortic dissection, which was never observed in wild-type mice. Nox2 transgenic aortas had increased endothelial ROS production, endothelial vascular cell adhesion molecule-1 expression, matrix metalloproteinase activity, and CD45(+) inflammatory cell infiltration. Conditioned media from Nox2 transgenic ECs induced greater Erk1/2 phosphorylation in vascular smooth muscle cells compared with wild-type controls through secreted cyclophilin A (CypA). Nox2 transgenic ECs (but not vascular smooth muscle cells) and aortas had greater secretion of CypA both at baseline and in response to Ang II stimulation. Knockdown of CypA in ECs abolished the increase in vascular smooth muscle cell Erk1/2 phosphorylation conferred by EC conditioned media, and preincubation with CypA augmented Ang II-induced vascular smooth muscle cell ROS production.

CONCLUSIONS

These findings demonstrate a pivotal role for EC-derived ROS in the determination of the susceptibility of the aortic wall to Ang II-mediated aortic dissection. ROS-dependent CypA secretion by ECs is an important signaling mechanism through which EC ROS regulate susceptibility of structural components of the aortic wall to aortic dissection.

Evaluation of methods of detecting cell reactive oxygen species production for drug screening and cell cycle studies

Intracellular reactive oxygen species (ROS) production is essential to normal cell function. However, excessive ROS production causes oxidative damage and cell death. Many pharmacological compounds exert their effects on cell cycle progression by changing intracellular redox state and in many cases cause oxidative damage leading to drug cytotoxicity. Appropriate measurement of intracellular ROS levels during cell cycle progression is therefore crucial in understanding redox-regulation of cell function and drug toxicity and for the development of new drugs. However, due to the extremely short half-life of ROS, measuring the changes in intracellular ROS levels during a particular phase of cell cycle for drug intervention can be challenging. In this article, we have provided updated information on the rationale, the applications, the advantages and limitations of common methods for screening drug effects on intracellular ROS production linked to cell cycle study. Our aim is to facilitate biomedical scientists and researchers in the pharmaceutical industry in choosing or developing specific experimental regimens to suit their research needs.

Divergent effects of p47(phox) phosphorylation at S303-4 or S379 on tumor necrosis factor-α signaling via TRAF4 and MAPK in endothelial cells

OBJECTIVE

To define the mechanism of p47(phox) phosphorylation in regulating endothelial cell response to tumor necrosis factor-α (TNFα) stimulation.

METHODS AND RESULTS

We replaced 11 serines (303-4, 310, 315, 320, 328, 345, 348, 359, 370, and 379) with alanines and investigated their effects on TNFα (100 U/mL, 30 minutes)-induced acute O(2)(.-) production and mitogen-activated protein kinase phosphorylation in endothelial cells. Seven constructs, S303-4A (double), S310A, S315A, S328A, S345A, S370A, and S379A, significantly reduced the O(2)(.-) production, and 4 of them (S328A, S345A, S370A, and S379A) also inhibited TNFα-induced extracellular-signal-regulated kinase (ERK) 1/2 phosphorylation. Blocking the phosphorylation of S303-4 and S379 inhibited most effectively TNFα-induced O(2)(.-) production. However, phosphorylation of S303-4 was not required for TNFα-induced p47(phox) membrane translocation and binding to TNF receptor-associated factor 4, ERK1/2 activation, and subsequent vascular cell adhesion molecule-1 expression. Knockout of p47(phox) or knockdown of TNF receptor-associated factor 4 using siRNA abolished TNFα-induced ERK1/2 phosphorylation, and inhibition of ERK1/2 activation significantly reduced the TNFα-induced vascular cell adhesion molecule-1 expression.

CONCLUSIONS

Phosphorylation of p47(phox) at different serine sites plays distinct roles in endothelial cell response to TNFα stimulation. Double serine (S303-4) phosphorylation is crucial for acute O(2)(.-) production, but is not involved in TNFα signaling through TNF receptor-associated factor 4 and ERK1/2. p47(phox) requires serine phosphorylation at distinct sites to support specific signaling events in response to TNFα.

Nox2-derived ROS in PPARγ signaling and cell-cycle progression of lung alveolar epithelial cells

Reactive oxygen species (ROS) play important roles in peroxisome proliferator-activated receptor γ (PPARγ) signaling and cell-cycle regulation. However, the PPARγ redox-signaling pathways in lung alveolar epithelial cells remain unclear. In this study, we investigated the in vivo and in vitro effects of PPARγ activation on the levels of lung ROS production and cell-cycle progression using C57BL/6J wild-type and Nox2 knockout mice (n=10) after intraperitoneal injection of a selective PPARγ agonist (GW1929, 5 mg/kg body wt, daily) for 14 days. Compared to vehicle-treated mice, GW1929 increased significantly the levels of ROS production in wild-type lungs, and this was accompanied by significant up-regulation of PPARγ, Nox2, PCNA, and cyclin D1 and phosphorylation of ERK1/2 and p38MAPK. These effects were absent in Nox2 knockout mice. In cultured alveolar epithelial cells, GW1929 (5 μM for 24 h) increased ROS production and promoted cell-cycle progression from G0/G1 into S and G2/M phases, and these effects were abolished by (1) adding a PPARγ antagonist (BADGE, 1 μM), (2) knockdown of PPARγ using siRNA, or (3) knockout of Nox2. In conclusion, PPARγ activation through Nox2-derived ROS promotes cell-cycle progression in normal mouse lungs and in cultured normal alveolar epithelial cells.

Knockout of p47 phox uncovers a critical role of p40 phox in reactive oxygen species production in microvascular endothelial cells

OBJECTIVE

p40(phox) is an important regulatory subunit of NADPH oxidase, but its role in endothelial reactive oxygen species (ROS) production remains unknown.

METHODS AND RESULTS

Using coronary microvascular endothelial cells isolated from wild-type and p47(phox) knockout mice, we found that knockout of p47(phox) increased the level of p40(phox) expression, whereas depletion of p40(phox) in wild-type cells increased p47(phox) expression. In both cases, the basal ROS production (without agonist stimulation) was well preserved. Double knockout of p40(phox) and p47(phox) dramatically reduced (approximately 65%) ROS production and cells started to die. The transcriptional regulation of p40(phox) and p47(phox) expressions involves HBP1. p40(phox) was prephosphorylated in resting cells. PMA stimulation induced p40(phox) swift dephosphorylation (within 1 minute) in parallel with the start of p47(phox) phosphorylation. p40(phox) was then rephosphorylated, and this was accompanied with an increase in ROS production. Depletion of p40(phox) resulted in approximately 67% loss in agonist-induced ROS production despite the presence of p47(phox). These were further supported by experiments on mouse aortas stimulated with angiotensin II.

CONCLUSIONS

p40(phox) is prephosphorylated in resting endothelial cells and can compensate p47(phox) in keeping basal ROS production. Dephosphorylation of p40(phox) is a prerequisite for agonist-induced p47(phox) phosphorylation, and p40(phox) through its dynamic dephosphorylation and rephosphorylation is involved in the regulation of agonist-induced ROS production.

Nox2 regulates endothelial cell cycle arrest and apoptosis via p21cip1 and p53

Endothelial cells (EC) express constitutively two major isoforms (Nox2 and Nox4) of the catalytic subunit of NADPH oxidase, which is a major source of endothelial reactive oxygen species. However, the individual roles of these Noxes in endothelial function remain unclear. We have investigated the role of Nox2 in nutrient deprivation-induced cell cycle arrest and apoptosis. In proliferating human dermal microvascular EC, Nox2 mRNA expression was low relative to Nox4 (Nox2:Nox4 approximately 1:13), but was upregulated 24 h after starvation and increased to 8+/-3.5-fold at 36 h of starvation. Accompanying the upregulation of Nox2, there was a 2.28+/-0.18-fold increase in O2.- production, a dramatic induction of p21cip1 and p53, cell cycle arrest, and the onset of apoptosis (all p<0.05). All these changes were inhibited significantly by in vitro deletion of Nox2 expression and in coronary microvascular EC isolated from Nox2 knockout mice. In Nox2 knockout cells, although there was a 3.8+/-0.5-fold increase in Nox4 mRNA expression after 36 h of starvation (p<0.01), neither O2.- production nor the p21cip1 or p53 expression was increased significantly and only 0.46% of cells were apoptotic. In conclusion, Nox2-derived O2.-, through the modulation of p21cip1 and p53 expression, participates in endothelial cell cycle regulation and apoptosis.

Abnormality of bone marrow-derived mesenchymal stem cells in patients with systemic lupus erythematosus

Bone marrow-derived mesenchymal stem cells (MSCs) are key components of the hematopoietic microenvironment and provide support to hematopoiesis and modulate immune system. Several studies suggest that SLE may be seen as stem cell disorders. However, it is unclear that whether MSCs from SLE patients are defective. So in this research, we studied the biological character of bone marrow derived MSCs in patients with SLE, focused on their phenotype (morphology and immunophenotype), karyotype, cytokines expression and hematopoietic support of MSCs. Our results showed that MSCs from SLE patients and normal controls can be successfully culture-expanded, but the MSCs from SLE grew more slowly than those of normal controls (P < 0.05). Cells from both groups were positive for CD29, CD44 and CD105, and negative for CD14, CD34, CD45 and HLA-DR. MSCs from SLE have a normal karyotype. Both groups express IL-6, IL7, IL-11, macrophage colony stimulating factor (M-CSF) and stem cell factor (SCF) at mRNA level. While IL-6 and IL-7 were down-regulated in MSCs from SLE patient (P < 0.05) at mRNA level. The MSCs from SLE patients and normal controls were infused into ICR (Tac: Icr: Ha strain) mice after high-dose chemotherapy, with no adverse events in either group. Recovery of white blood cells, hemoglobin and platelet was more rapid (P < 0.05) compared with the group without MSCs infusion. We conclude that MSCs in patient with SLE have abnormalities compared with those in normal control. MSCs in patient with SLE may play an important role in the SLE pathogenesis.

Acute tumor necrosis factor alpha signaling via NADPH oxidase in microvascular endothelial cells: role of p47phox phosphorylation and binding to TRAF4

Tumor necrosis factor alpha (TNF-alpha) receptor-associated factors (TRAFs) play important roles in TNF-alpha signaling by interacting with downstream signaling molecules, e.g., mitogen-activated protein kinases (MAPKs). However, TNF-alpha also signals through reactive oxygen species (ROS)-dependent pathways. The interrelationship between these pathways is unclear; however, a recent study suggested that TRAF4 could bind to the NADPH oxidase subunit p47phox. Here, we investigated the potential interaction between p47phox phosphorylation and TRAF4 binding and their relative roles in acute TNF-alpha signaling. Exposure of human microvascular endothelial cells (HMEC-1) to TNF-alpha (100 U/ml; 1 to 60 min) induced rapid (within 5 min) p47phox phosphorylation. This was paralleled by a 2.7- +/- 0.5-fold increase in p47phox-TRAF4 association, membrane translocation of p47phox-TRAF4, a 2.3- +/- 0.4-fold increase in p47phox-p22phox complex formation, and a 3.2- +/- 0.2-fold increase in NADPH-dependent O2- production (all P < 0.05). TRAF4-p47phox binding was accompanied by a progressive increase in extracellular signal-regulated kinases 1 and 2 (ERK1/2) and p38(MAPK) activation, which was inhibited by an O2- scavenger, tiron. TRAF4 predominantly bound the phosphorylated form of p47phox, in a protein kinase C-dependent process. Knockdown of TRAF4 expression using siRNA had no effect on p47phox phosphorylation or binding to p22phox but inhibited TNF-alpha-induced ERK1/2 activation. In coronary microvascular EC from p47phox-/- mice, TNF-alpha-induced NADPH oxidase activation, ERK1/2 activation, and cell surface intercellular adhesion molecule 1 (ICAM-1) expression were all inhibited. Thus, both p47phox phosphorylation and TRAF4 are required for acute TNF-alpha signaling. The increased binding between p47phox and TRAF4 that occurs after p47phox phosphorylation could serve to spatially confine ROS generation from NADPH oxidase and subsequent MAPK activation and cell surface ICAM-1 expression in EC.

Media remodeling – the result of stent induced media necrosis and repair

Background: Stents have been introduced clinically to help maintaining the patency of the vascular lumen after balloon angioplasty. To ensure a sufficient lumen of the stented vessel, oversized stents are frequently used. However especially deployment of oversized stents may lead to mechanical injury of the intima and media of the vessel wall. The aim of the study was to characterize the vascular lesions and repair processes within the first 4 weeks after implantation of oversized stents in the rabbit carotid artery and thereby contribute to the understanding of vascular remodeling during stent implantation. Methods: Oversized stents were implanted in the carotid artery of Chinchilla rabbits. Rabbits were sacrificed 3, 7, 14, and 28 days after stent implantation and a detailed histologic and immunohistochemical analysis was performed. Results: The carotid artery was expanded by a factor of 1.3–1.5, leading to a constant dilatation of the vessel. The struts were deeply impressed in the vessel wall, resulting in a disruption of the intima, thrombus formation, media compression and segmental media necrosis. The necrotic media was repopulated by smooth muscle cells by day 7. In contrast to the intima lesions, necrotic areas of the media were not invaded by an inflammatory infiltrate. Formation of neointima, characterized by a confluent layer of endothelial cells and deposition collagen fibers started in close vicinity of the struts. Conclusions: Being part of a high-pressure system, the arterial vessel apparently adapts to constant dilatation. Deployment of oversized stents caused intima disruption, media necrosis of varying degree and constant dilatation of the vessel wall. Necrosis and repopulation of smooth muscle cells of the media took place within the first 4 weeks, leading to the speculation whether the repopulating SMC are more resistant to the constant pressure.

Opposing Roles of p47 phox in Basal Versus Angiotensin II–Stimulated Alterations in Vascular O 2 − Production, Vascular Tone, and Mitogen-Activated Protein Kinase Activation

Background— NADPH oxidase is a major source of vascular superoxide (O 2 − ) production and is implicated in angiotensin II (Ang II)–induced oxidant stress. The p47 phox subunit plays an important role in Ang II–induced oxidase activation, but its role in basal oxidase activity and vascular function is unclear.

Methods and Results— Aortae from p47 phox−/− and matched wild-type (WT) mice (n=9/group) were incubated ex vivo with or without Ang II (200 nmol/L, 30 minutes) and then examined for (1) NADPH-dependent O 2 − production, (2) endothelium-dependent and -independent vascular relaxation, and (3) activation of mitogen-activated protein kinases (MAPKs). In the absence of Ang II, p47 phox−/− vessels had slightly but significantly higher (1.3±0.1-fold; P <0.05) NADPH-dependent O 2 − production than WT; impaired relaxation to acetylcholine (maximum 54±4% versus 80±3%; P <0.05), which was normalized to WT levels by the O 2 − scavenger tiron or by Mn(III)tetrakis(1-methyl-4-pyridyl)porphyrin pentachloride, and increased basal phosphorylation of ERK1/2, p38MAPK, and JNK compared with WT. In WT aortae, Ang II increased NADPH-dependent O 2 − production (2.5±0.5-fold; P <0.05), impaired relaxation to acetylcholine (maximum 60±6% versus 80±3%; P <0.05), and increased ERK1/2, p38MAPK, and JNK phosphorylation ( P <0.05). In contrast, Ang II failed to increase O 2 − production, impair acetylcholine responses, or increase MAPK activation in p47 phox−/− aortae.

Conclusions— p47 phox plays a complex dual role in the vasculature. It inhibits basal NADPH oxidase activity but is critical for Ang II–induced vascular dysfunction via activation of NADPH oxidase.

Targeting alphavbeta3 and alpha5beta1 for gene delivery to proliferating VSMCs: synergistic effect of TGF-beta1

TGF-beta1 levels increase after vascular injury and promote vascular smooth muscle cell (VSMC) proliferation. We define a nonviral gene delivery system that targets alphavbeta3 and alpha5beta1 integrins that are expressed on proliferating VSMCs and strongly induced by TGF-beta1. A 15-amino acid RGDNP-containing peptide from American Pit Viper venom was linked to a Lys(16) peptide as vector (molossin vector) and complexed with Lipofectamine or fusogenic peptide for delivery of luciferase or beta-galactosidase reporter genes to primary cultures of human, rabbit, and rat VSMCs. Preincubation of VSMCs with TGF-beta1 for 24 h, but not with PDGF-BB, interferon-gamma, TNF-alpha, nor PMA, increased alphavbeta3 and alpha5beta1 expressions on VSMCs and enhanced gene delivery of molossin vector. Thus beta-galactosidase activity increased from 35 +/- 5% (controls) to 75 +/- 5% after TGF-beta1 treatment, and luciferase activity increased fourfold over control values. Potential use of this system in vessel bypass surgery was examined in an ex vivo rat aortic organ culture model after endothelial damage. Molossin vector system delivered beta-galactosidase to VSMCs in the vessel wall that remained for up to 12 days posttransfection. The molossin vector system, when combined with TGF-beta1, enhances gene delivery to proliferating VSMCs and might have clinical applications for certain vasculoproliferative diseases.

In vitro Arabidopsis pollen germination and characterization of the inward potassium currents in Arabidopsis pollen grain protoplasts

The focus of this study is to investigate the regulatory role of K(+) influx in Arabidopsis pollen germination and pollen tube growth. Using agar-containing media, in vitro methods for Arabidopsis pollen germination have been successfully established for the first time. The pollen germination percentage was nearly 75% and the average pollen tube length reached 135 microm after a 6 h incubation. A decrease in external K(+) concentration from 1 mM to 35 microM resulted in 30% inhibition of pollen germination and 40% inhibition of pollen tube growth. An increase in external K(+) concentration from 1 mM to 30 mM stimulated pollen tube growth but inhibited pollen germination. To study how K(+) influx is associated with pollen germination and tube growth, regulation of the inward K(+) channels in the pollen plasma membrane was investigated by conducting patch-clamp whole-cell recording with pollen protoplasts. K(+) currents were first identified in Arabidopsis pollen protoplasts. The inward K(+) currents were insensitive to changes in cytoplasmic Ca(2+) but were inhibited by a high concentration of external Ca(2+). A decrease of external Ca(2+) concentration from 10 mM (control) to 1 mM had no significant effect on the inward K(+) currents, while an increase of external Ca(2+) concentration from 10 mM to 50 mM inhibited the inward K(+) currents by 46%. Changes in external pH significantly affected the magnitude, conductance, voltage-independent maximal conductance, and activation kinetics of the inward K(+) currents. The physiological importance of potassium influx mediated by the inward K(+)-channels during Arabidopsis pollen germination and tube growth is discussed.

Identification and characterization of the inward K+ channel in the plasma membrane of Brassica pollen protoplasts

Patch clamp techniques have been used to identify and characterize the whole-cell currents carried by inward K+ channels in isolated matured pollen protoplasts of Brassica chinensis var. chinensis. The whole-cell inward currents in the isolated pollen protoplasts were activated at hyperpolarized membrane potentials more negative than -100 mV. The magnitudes of the whole-cell inward currents were strongly dependent on the external K+ concentration, and were highly selective for K+ over other monovalent cations. The inward currents were not observed when external K+ was replaced with the same concentration of Cs+ or Na+. The addition of 1 mM or 10 mM Ba2+ in external solutions resulted in 30% or 80% inhibition of the inward currents at -180 mV, respectively. These results demonstrated that the inward K+ currents mainly account for the recorded whole-cell inward currents in Brassica pollen protoplasts. Increase of cytoplasmic Ca2+ concentrations from 10 nM to 30 microM or even 5 mM did not affect the inward K+ currents. Decrease of external Ca2+ concentrations from 10 mM to 1 mM inhibited the inward K+ currents by 25%, while the increase of external Ca2+ from 10 mM to 50 mM almost completely blocked the inward K+ currents. Physiological importance of K+ transport into pollen and its possible regulatory mechanisms are also discussed.

Familial hypercholesterolemia in China. Identification of mutations in the LDL-receptor gene that result in a receptor-negative phenotype

Familial hypercholesterolemia (FH), caused by many different mutations in the low-density lipoprotein (LDL)-receptor gene, invariably leads to severe premature coronary heart disease (CHD) in homozygous individuals. Heterozygous FH patients are less severely affected but are still at increased risk of CHD in most populations. Although FH homozygotes in China are affected similarly to those elsewhere, heterozygotes are not detected in the general population and obligate heterozygotes are often not hypercholesterolemic by Western standards. Mutations in the LDL-receptor genes of 10 homozygous FH patients from the Jiang-su province of China and their heterozygous parents were analyzed. These include one large and two minor deletions and eight point mutations: four are predicted to introduce a premature stop codon, five to result in a single amino acid substitution or deletion, and one to produce a protein with an abnormal cytoplasmic tail. Expression of the mutant LDL-receptor cDNAs in vitro confirmed that these mutations impaired LDL-receptor function and that several would cause a receptor-negative phenotype. Thus, the lack of clinical expression in obligate FH heterozygotes is not due to unusually "mild" mutations in the LDL-receptor gene, and other genetic or environmental factors must therefore be important in determining phenotypic expression.

[The relation of polymorphism of low-density lipoprotein receptor gene with serum cholesterol levels]

PvuII polymorphism of LDL receptor gene and serum lipid levels were analysed in 115 normolipidemic subjects and 57 individuals with hypercholesterolemia. A significant relationship was found between P2 allele and lower serum cholesterol level, suggesting that the LDL receptor may contribute to the variation in cholesterol levels in normolipidemic population. Although the frequency of P2 allele in the Chinese was lower than in westerners, the serum cholesterol levels in the Chinese were not higher or even lower than that in westerners. This might be attributed to the difference in diet, lifestyle or other genes which are related to cholesterol metabolism between the Chinese and westerners.

The association of hepatic apoprotein and lipid metabolism in hamsters and rats

1. The hamster liver but not that of the rat, secretes VLDL containing only apoprotein B100. Apoprotein B48 was identified in mesenteric lymph of hamsters and therefore plasma apoprotein B48 is of intestinal origin. 2. Male hamster livers secrete less free cholesterol but similar cholesterol ester than male rats resulting in a higher CE/FC ratio in hamsters. 3. Hepatic VLDL from male hamsters contain more apo B and E while that from females contains more TG and apo A-II/C. 4. Hamsters fed high-C diets secrete more hepatic VLDL-apoprotein B, -free and -cholesterol ester, and biliary cholesterol.

Homozygous familial hypercholesterolemic patients in China

Five homozygous patients with familial hypercholesterolemia (FH) are described. Their serum cholesterol levels were between 603 and 907 mg/dl, with an average of 714 mg/dl. The mean value of serum cholesterol levels of the obligate heterozygous parents was 270 mg/dl. In the patient group, 87% of the serum cholesterol was distributed in low density lipoprotein (LDL) and the mean LDL cholesterol level was about 8.4 times that in a control group. Phospholipids in HDL in the patient group were significantly lower than in the controls. Lipid assays of xanthoma tissues revealed that the major lipid was cholesterol and its esters. LDL receptor activity in fibroblasts from the homozygotes was markedly decreased. Two patients yielded less than 2% of normal receptor activity and were classified as receptor-negative. The other 3 revealed receptor activities greater than 2% but less than 25% of normal receptor activity and were classified as receptor-defective.