Targeting TRAF3IP2 by Genetic and Interventional Approaches Inhibits Ischemia/Reperfusion-induced Myocardial Injury and Adverse Remodeling

Re-establishing blood supply is the primary goal for reducing myocardial injury in subjects with ischemic heart disease. Paradoxically, reperfusion results in nitroxidative stress and a marked inflammatory response in the heart. TRAF3IP2 (TRAF3 Interacting Protein 2; previously known as CIKS or Act1) is an oxidative stress-responsive cytoplasmic adapter molecule that is an upstream regulator of both IκB kinase (IKK) and c-Jun N-terminal kinase (JNK), and an important mediator of autoimmune and inflammatory responses. Here we investigated the role of TRAF3IP2 in ischemia/reperfusion (I/R)-induced nitroxidative stress, inflammation, myocardial dysfunction, injury, and adverse remodeling. Our data show that I/R up-regulates TRAF3IP2 expression in the heart, and its gene deletion, in a conditional cardiomyocyte-specific manner, significantly attenuates I/R-induced nitroxidative stress, IKK/NF-κB and JNK/AP-1 activation, inflammatory cytokine, chemokine, and adhesion molecule expression, immune cell infiltration, myocardial injury, and contractile dysfunction. Furthermore, Traf3ip2 gene deletion blunts adverse remodeling 12 weeks post-I/R, as evidenced by reduced hypertrophy, fibrosis, and contractile dysfunction. Supporting the genetic approach, an interventional approach using ultrasound-targeted microbubble destruction-mediated delivery of phosphorothioated TRAF3IP2 antisense oligonucleotides into the LV in a clinically relevant time frame significantly inhibits TRAF3IP2 expression and myocardial injury in wild type mice post-I/R. Furthermore, ameliorating myocardial damage by targeting TRAF3IP2 appears to be more effective to inhibiting its downstream signaling intermediates NF-κB and JNK. Therefore, TRAF3IP2 could be a potential therapeutic target in ischemic heart disease.

Glucocorticoid dose thresholds associated with all-cause and cardiovascular mortality in rheumatoid arthritis

OBJECTIVE

To delineate daily and cumulative glucocorticoid dose thresholds associated with increased mortality rates in rheumatoid arthritis (RA).

METHODS

We studied RA patients recruited from rheumatology clinics. Annually, we assessed the glucocorticoid dose, demographic, socioeconomic, clinical, and laboratory features of RA, cardiovascular (CV) risk factors, and vital status. We used Cox proportional hazards regression to assess associations between the daily or cumulative glucocorticoid dose and death, adjusting for potential confounders and for the propensity to receive glucocorticoids. We tested strata of the glucocorticoid dose to delineate the threshold associated with death.

RESULTS

We studied 779 RA patients with a total of 7,203 person-years of observation, during which 237 of them died, yielding a mortality rate of 3.2 per 100 person-years (95% confidence interval [95% CI] 2.8-3.7). One hundred twenty of the deaths were due to CV causes, yielding a CV mortality rate of 1.8 (95% CI 1.5-2.1). Exposure to glucocorticoids was associated with a dose-dependent increase in death from all causes, with a ratio (HR) of 1.07 per mg of prednisone per day (95% CI 1.05-1.08). Compared to patients who were not receiving corticosteroids, the minimum daily prednisone dose threshold associated with an increase in all-cause mortality was 8-15 mg, with an adjusted HR of 1.78 (95% CI 1.22-2.60). For the cumulative dose of glucocorticoids, the minimum dosage associated with all-cause mortality was 40 gm (HR 1.74 [95% CI 1.25-2.44]).

CONCLUSION

Glucocorticoid use in RA is associated with a dose-dependent increase in mortality rates, with a daily threshold dose of 8 mg, at which the number of deaths increased in a dose-dependent manner. These findings may assist clinicians in selecting the appropriate glucocorticoid dosage for RA patients who require these agents.

Systemic inflammation and cardiovascular risk factors predict rapid progression of atherosclerosis in rheumatoid arthritis

OBJECTIVE

To estimate atherosclerosis progression and identify influencing factors in rheumatoid arthritis (RA).

METHODS

We used carotid ultrasound to measure intima-media thickness (IMT) in RA patients, and ascertained cardiovascular (CV) risk factors, inflammation markers and medications. A second ultrasound was performed approximately 3 years later. We calculated the progression rate by subtracting the baseline from the follow-up IMT, divided by the time between the two scans. We used logistic regression to identify baseline factors predictive of rapid progression. We tested for interactions of erythrocyte sedimentation rate (ESR) with CV risk factors and medication use.

RESULTS

Results were available for 487 RA patients. The mean (SD) common carotid IMT at baseline was 0.571 mm (0.151). After a mean of 2.8 years, the IMT increased by 0.050 mm (0.055), p≤0.001, a progression rate of 0.018 mm/year (95% CI 0.016 to 0.020). Baseline factors associated with rapid progression included the number of CV risk factors (OR 1.27 per risk factor, 95% CI 1.01 to 1.61), and the ESR (OR 1.12 per 10 mm/h, 95% CI 1.02 to 1.23). The ESR×CV risk factor and ESR×medication product terms were significant, suggesting these variables modify the association between the ESR and IMT progression.

CONCLUSIONS

Systemic inflammation and CV risk factors were associated with rapid IMT progression. CV risk factors may modify the role of systemic inflammation in determining IMT progression over time. Methotrexate and antitumour necrosis factor agents may influence IMT progression by reducing the effect of the systemic inflammation on the IMT.

Exercise training combined with angiotensin II receptor blockade reduces oxidative stress after myocardial infarction in rats

An increase in oxidative stress and decrease in antioxidant enzymes have been suggested to be involved in the pathophysiology of myocardial infarction (MI). In this study in rats, treadmill exercise training and losartan treatment began 1 week post-myocardial infarction (MI) and lasted 8 weeks. We evaluated the changes in the mRNA and protein expressions for the enzymatic antioxidants superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase after exercise and losartan treatment post-MI. Our results demonstrated that GPx and catalase mRNA levels were comparable among all the groups, while the mRNA level for manganese SOD (MnSOD) was significantly increased in exercise training with/without losartan treatment compared with the sedentary post-MI group. Moreover, the mRNA level for gp91(phox) was dramatically decreased by a combination of exercise and losartan treatment. The protein levels for MnSOD were significantly elevated by exercise training in combination with losartan treatment. The protein levels for catalase were significantly increased in response to exercise, and further augmented by exercise together with losartan treatment. Thiobarbituric acid-reactive substances in plasma were significantly increased in the post-MI rats, but were decreased by exercise or losartan treatment, indicating that both exercise and losartan may reduce lipid oxidative damage. In addition, catalase and SOD enzymatic activities were significantly enhanced by exercise combined with losartan treatment. Our results suggest that exercise training improves catalase and MnSOD expression and attenuates oxidative stress. These effects are potentiated when combining exercise with angiotensin II receptor blockade.

Effects of exercise and L-arginine on ventricular remodeling and oxidative stress

OBJECTIVE

Our aim was to characterize the changes in messenger RNA (mRNA) abundance, protein, and activity levels of the enzymatic antioxidants, superoxide dismutase (SOD), glutathione peroxidase, and catalase by exercise training combined with L-arginine after myocardial infarction (MI).

METHODS

L-Arginine (1 g x kg(-1) x d(-1)) and N(G)-nitro-L-arginine methyl ester (L-NAME; 10 mg x kg(-1) x d(-1)) were administered in drinking water for 8 wk. Sprague-Dawley rats were randomized to the following groups: sham-operated control (Sham); MI sedentary (Sed); MI exercise (Ex); MI sedentary + L-arginine (Sed + LA); MI exercise + L-arginine (Ex + LA); MI sedentary + L-NAME (Sed + L-NAME); and MI exercise + L-NAME (Ex + L-NAME).

RESULTS

The glutathione peroxidase, catalase, and gp91(phox) mRNA levels were comparable among all the groups. The SOD mRNA level was significantly increased in the Ex group (5.43 +/- 0.87) compared with the Sed group (1.74 +/- 0.29), whereas this effect was pronouncedly down-regulated by the L-NAME intervention (2.51 +/- 1.17, P < 0.05). The protein levels of SOD in the Sed and Ex groups were both significantly decreased with the administration of L-NAME. The protein levels of catalase were significantly higher in the Ex and Ex + LA groups than that in the Sed, Sed + LA, and L-NAME-treated groups. The collagen volume fraction was significantly lowered by the exercise and/or L-arginine treatment when compared with the Sed group. Fractional shortening was significantly preserved in the trained groups compared with their corresponding sedentary groups with or without drug treatments. However, the beneficial effect was not further improved by L-arginine treatment.

CONCLUSIONS

Our results suggest that exercise training exerts antioxidative effects and attenuates myocardial fibrosis in the MI rats. These improvements, in turn, alleviate cardiac stiffness and preserve post-MI cardiac function. In addition, L-arginine appears to have no additive effect on cardiac function or expression of enzymatic antioxidants.

Effects of exercise training on cardiac function and myocardial remodeling in post myocardial infarction rats

To test the hypothesis that early exercise training after myocardial infarction (MI) could preserve cardiac function, alleviate left ventricular (LV) remodeling and induce a protective effect on morphology, male Sprague-Dawley rats underwent coronary ligation or sham operation, and were assigned to 3 groups: Sham, sedentary MI (SedMI), and exercise MI (ExMI). We measured the changes in collagen volume fraction, matrix metalloproteinase (MMP) 1, tissue inhibitor matrix metalloproteinase 1 (TIMP-1), angiotensin II receptor type 1 (AT1), and angiotensin converting enzyme (ACE) at gene and protein levels after 8 weeks of exercise training. Cardiac functions were determined by echocardiographic and hemodynamic measurements. Early exercise training after MI had no effect on LV wall thinning. Cardiac function was significantly preserved in the ExMI group in comparison to the SedMI group. The collagen volume fraction in the ExMI group was significantly lower than in the SedMI group. Compared to the SedMI group, the ExMI group showed a markedly decrease at both the gene and protein levels in TIMP-1 (P<0.05). No significant differences were found in MMP-1 among the three groups. MMP-1/TIMP-1 ratio in the ExMI group was significantly higher than in the SedMI group. In addition, the expression of AT1 protein in the ExMI group was significantly lower than in the SedMI group. Furthermore, both ACE mRNA expression and ACE binding in the ExMI group are significantly decreased compared to the SedMI group. Our results suggest that early exercise training after MI reduces TIMP-1 expression, improves the balance between MMPs and TIMPs, and mitigates the expressions of ACE and AT1 receptor. These improvements, in turn, attenuate myocardial fibrosis and preserve post-MI cardiac function.

Ultrasound-targeted antisense oligonucleotide attenuates ischemia/reperfusion-induced myocardial tumor necrosis factor-alpha

Ultrasound contrast agents are now emerging as effective vehicles for delivering therapeutic agents to target tissues. In the present study, we used ultrasound-targeted, contrast-bound antisense oligonucleotides to inhibit the expression of tumor necrosis factor-alpha (TNF-alpha), a proinflammatory cytokine with negative inotropic effects. We compared the efficacy of left ventricular vs. intravenous administration and determined the optimal time for delivery. WKY rats were treated with perfluorocarbon-exposed sonicated dextrose albumin (PESDA) microspheres incubated with 100 microg of antisense oligonucleotide directed against TNF-alpha. Contrast was infused into either the superior vena cava or the left ventricular cavity along with simultaneous application of ultrasound. Twenty-four hours later, the animals underwent 15 min of ischemia and 2 h reperfusion. Control animals underwent sham operation only, ischemia/reperfusion only, or received PESDA only. A second group received treatment just prior to, or immediately after the onset of ischemia. At the end of the experimental period, hearts were removed and analyzed for TNF-alpha by northern and western blotting. While no TNF-alpha expression was detected in sham-operated animals, robust expression of TNF-alpha mRNA and protein was seen in controls treated with ultrasound and PESDA alone. In contrast, intravenous or left ventricular administration of antisense oligonucleotides significantly inhibited ischemia/reperfusion-induced TNF-alpha expression. Direct delivery into the left ventricular cavity was more effective than intravenous administration, and delivery just prior to ischemia was most effective in attenuating TNF-alpha expression. Furthermore, attenuation of TNF-alpha expression also significantly inhibited other post-ischemic inflammatory mediators including IL-1beta and intercellular adhesion molecule-1 (ICAM-1). Thus, ultrasound-targeted antisense oligonucleotides can effectively attenuate post-ischemic cytokine expression when delivered in a clinically relevant time frame, obviating the need for pretreatment.

Validation of a mouse conductance system to determine LV volume: comparison to echocardiography and crystals

The application of left ventricular pressure-volume analysis to transgenic mice to characterize the cardiac phenotype has been problematic due to the small size of the mouse heart and the rapid heartbeat. Conductance technology has been miniaturized for the mouse and can solve this problem. However, there has been no validation of this technique. Accordingly, we performed echocardiography followed by simultaneous ultrasonic crystals, flow probe, and conductance studies in 18 CD-1 mice. Raw conductance volumes were corrected for an inhomogenous electrical field (alpha) and parallel conductance (G(pi)) yielding a stroke volume of 14.1 +/- 3.7 microliter/beat, end-diastolic volume of 20.8 +/- 6.5 microliter, and end-systolic volume of 9.0 +/- 5.8 microliter. The mean conductance volumes were no different from those derived by flow probe and echocardiography but did differ from ultrasonic crystals. G(pi) was determined to be 14.9 +/- 8.7 microliter. However, hypertonic saline altered dimension and pressure in the mouse left ventricle. Although G(pi) can be determined by the hypertonic saline method, saline altered hemodynamics, questioning its validity in the mouse. Although mean measures of absolute volume may be similar among different techniques, individual values did not correlate.

The importance of play in adulthood. An interview with Joan M. Erikson. Interview by Daniel Benveniste

Joan M. Erikson (1902-1997) was an artist, a writer, a mother, and the wife and collaborator of Erik H. Erikson (1902-1994), one of the most important and influential psychoanalysts in the world. The following is an edited dialogue on one of her favorite topics--The Importance of Play in Adulthood. It features her thoughts on the subject and reminiscences of the ways she played throughout her life. She muses on play in relation to humor, fun, the role of the fool, and more. The article was a project undertaken in the spirit of play and it will hopefully evoke further playful musings in the minds of readers.

Radial approach: a new concept in surgical treatment for atrial fibrillation. II. Electrophysiologic effects and atrial contribution to ventricular filling

BACKGROUND

In a previous study the atrial incisions that follow the concept of the radial approach were designed according to the activation sequence during sinus rhythm and the atrial coronary artery anatomy in normal dogs. The purpose of the present study was to determine whether the radial approach provides a more physiologic activation sequence and atrial transport function than the maze procedure.

METHODS

Ten dogs that had undergone the radial approach (n = 5) or the maze procedure (n = 5) were studied 6 weeks postoperatively. Sinus node function and inducibility of atrial fibrillation were examined before and after operation. The atria were mapped endocardially with 212 electrodes, and atrial activation sequences during sinus rhythm and right atrial pacing were examined. Atrial transport function was assessed by transepicardial Doppler echocardiography.

RESULTS

No dogs developed sinus node dysfunction postoperatively. Both the radial approach and the maze procedure equally prevented sustained atrial fibrillation. The atrial activation sequence was more synchronous after the radial approach than after the maze procedure. There was no electrically isolated region after the radial approach. The total activation time of the left atrium was significantly shorter after the radial approach than after the maze procedure (53.6+/-9.8 versus 70.5+/-9.6 ms, p<0.05). The ratio of peak flow velocity of the E wave to the A wave (peak E/A) of the transmitral Doppler flow was significantly smaller after the radial approach than after the maze procedure (1.7+/-0.4 versus 3.5+/-1.7, p<0.05). The atrial filling fraction of the transmitral Doppler flow was significantly larger after the radial approach than after the maze procedure (29.9%+/-7.3% versus 14.8%+/-5.0%, p<0.01). There was no significant difference in peak E/A and atrial filling fraction of the transtricuspid Doppler flow between the two procedures.

CONCLUSIONS

The radial approach provides a more synchronous activation sequence and atrial transport function, and thus may represent a more physiologic alternative to the maze procedure as a surgical treatment for atrial fibrillation.

Endothelin-1 and myocardial preconditioning

This study attempted to define the role of endothelin (ET) in preconditioning. We previously showed that ET Is produced during myocardial ischemia and reperfusion. Because both preconditioning and ET act through protein kinase C, ET could play a role in preconditioning. Dogs were randomized to three groups subjected to 40 minutes of ischemia, with (groups A and B) or without (group C) preconditioning, followed by 4 hours of reperfusion. Groups A and C received saline infusions; group B received continuous infusions of the ETA-selective antagonist FR139317. Both preconditioned groups had smaller infarct sizes (group A, 7.9% +/- 2.5%; group B, 8.4% +/- 2.6%) than the nonpreconditioned group (group C, 16.2% +/- 3.3%). Administration of the ETA antagonist FR139317 did not alter infarct size. This study demonstrated that ETA-receptor blockade did not alter infarct size in preconditioned animals and suggests that endothelin does not play a significant role in this process.

Cytotoxicity and DNA damage caused by the azoxy metabolites of procarbazine in L1210 tumor cells

Procarbazine, a chemotherapeutic hydrazine, is thought to be metabolized to an alkylating species similar to methyl carbonium ion by multistep reactions involving cytochrome P-450, monoamine oxidase, and cytosolic enzymes. The DNA-damaging and cytotoxic potential of procarbazine and its metabolites in murine L1210 leukemia tumor cells in vitro was determined using alkaline elution techniques and extrapolation of growth curves. Neither procarbazine nor any of the chemical degradation products (except for the aldehyde derivative at high concentrations) caused significant amounts of DNA strand breakage. The primary enzymatic oxidation product, azo-procarbazine, did not produce strand breakage. However, exposure of the cells to either of the two isomers of azoxy-procarbazine led to significant DNA damage and cytotoxicity. DNA damage included both single-strand breaks and alkali-labile sites. At equimolar concentrations, the azoxy 2 isomer of procarbazine caused 14 to 20 times more DNA damage than did the azoxy 1 metabolite. When cell growth is expressed as percentage survival of L1210 cells, the azoxy 2 isomer was approximately 7-fold more toxic than the azoxy 1 metabolite. The other metabolites tested showed little or no cytotoxicity. L1210 cells were shown to contain little or no cytochrome P-450 or monoamine oxidase activity, which may account for the lack of toxicity of the parent drug or the primary oxidative metabolite, azo-PCZ, to these cells. The conversion of procarbazine to the azoxy-procarbazine isomers in vivo must occur in cells which contain these enzymes, such as liver. However, the azoxy isomers of procarbazine were metabolized in L1210 cells, presumably leading to the DNA or cytotoxic damage observed.

Oxidative metabolism of some hydrazine derivatives by rat liver and lung tissue fractions

The enzyme systems in rat liver and lung responsible for the oxidative metabolism of hydrazine derivatives were studied to determine whether these enzymes, cytochrome P-450 and monoamine oxidase, were responsible for metabolically activating hydrazines to carcinogenic/toxic metabolites. Cytochrome P-450 preferentially oxidized the nitrogen to nitrogen bond of 1,2-disubstituted hydrazines and hydrazides, while monoamine oxidase oxidized the nitrogen to nitrogen bond of all the classes of hydrazine derivatives that were tested. Oxidation of the nitrogen to nitrogen bond led to the formation of stable azo intermediates in the case of 1,2-disubstituted hydrazines and to unstable monoazo (diazene) metabolites in the case of monosubstituted hydrazines and hydrazides. In addition, cytochrome P-450 preferentially oxidized the carbon to nitrogen bond of monoalkylhydrazines; this reaction resulted in the formation of aldehyde metabolites (via hydrazone intermediates). Monosubstituted hydrazines were shown to be potent, irreversible inhibitors of mitochondrial monoamine oxidase. In contrast, the 1,2-disubstituted hydrazines appeared to be good substrates for the monoamine oxidase and served as competitive inhibitors at high concentrations. There did not appear to be any monoamine oxidase isozyme (form A or B) specificity in the metabolism of either the 1,2-disubstituted hydrazines or the monoalkylhydrazines, ethyl- and n-propylhydrazine.

The arts as healing

The relationship between artistic involvement and individual mental health is considered, and the concept of "healing" is differentiated from that of "therapy." Seven properties of art experience are identified which, when developed, have contributed to patients' recovery from mental illness. Implications of these properties for clinical programs, and the related value of art experience for non-patients, are discussed.

Preparation of Amine Salts of Thymolphthalein Monophosphate and Their Use for Measuring Phosphatase Activity

An easy and quick preparation of amine salts of thymolphthalein monophosphate is described. All of the salts prepared are stable, nonhygroscopic, soluble powders. The 2-amino-2-methyl-1,3-propandiol salt is preferred for use as a substrate for measuring phosphatase activities because of its high solubility and easy preparation.