Calpain-2 Compensation Promotes Angiotensin II-Induced Ascending and Abdominal Aortic Aneurysms in Calpain-1 Deficient Mice

BACKGROUND AND OBJECTIVE: Recently, we demonstrated that angiotensin II (AngII)-infusion profoundly increased both aortic protein and activity of calpains, calcium-activated cysteine proteases, in mice. In addition, pharmacological inhibition of calpain attenuated AngII-induced abdominal aortic aneurysm (AA) in mice. Recent studies have shown that AngII infusion into mice leads to aneurysmal formation localized to the ascending aorta. However, the precise functional contribution of calpain isoforms (-1 or -2) in AngII-induced abdominal AA formation is not known. Similarly, a functional role of calpain in AngII-induced ascending AA remains to be defined. Using BDA-410, an inhibitor of calpains, and calpain-1 genetic deficient mice, we examined the relative contribution of calpain isoforms in AngII-induced ascending and abdominal AA development. METHODOLOGY/RESULTS: To investigate the relative contribution of calpain-1 and -2 in development of AngII-induced AAs, male LDLr -/- mice that were either calpain-1 +/+ or -/- were fed a saturated fat-enriched diet and infused with AngII (1,000 ng/kg/min) for 4 weeks. Calpain-1 deficiency had no significant effect on body weight or blood pressure during AngII infusion. Moreover, calpain-1 deficiency showed no discernible effects on AngII-induced ascending and abdominal AAs. Interestingly, AngII infusion induced increased expression of calpain-2 protein, thus compensating for total calpain activity in aortas of calpain-1 deficient mice. Oral administration of BDA-410, a calpain inhibitor, along with AngII-infusion significantly attenuated AngII-induced ascending and abdominal AA formation in both calpain-1 +/+ and -/- mice as compared to vehicle administered mice. Furthermore, BDA-410 administration attenuated AngII-induced aortic medial hypertrophy and macrophage accumulation. Western blot and immunostaining analyses revealed BDA-410 administration attenuated AngII-induced C-terminal fragmentation of filamin A, an actin binding cytoskeletal protein in aorta. CONCLUSION: Calpain-2 compensates for loss of calpain-1, and both calpain isoforms are involved in AngII-induced aortic aneurysm formation in mice

Calpain-2 Compensation Promotes Angiotensin II-Induced Ascending and Abdominal Aortic Aneurysms in Calpain-1 Deficient Mice

Background and Objective Recently, we demonstrated that angiotensin II (AngII)-infusion profoundly increased both aortic protein and activity of calpains, calcium-activated cysteine proteases, in mice. In addition, pharmacological inhibition of calpain attenuated AngII-induced abdominal aortic aneurysm (AA) in mice. Recent studies have shown that AngII infusion into mice leads to aneurysmal formation localized to the ascending aorta. However, the precise functional contribution of calpain isoforms (-1 or -2) in AngII-induced abdominal AA formation is not known. Similarly, a functional role of calpain in AngII-induced ascending AA remains to be defined. Using BDA-410, an inhibitor of calpains, and calpain-1 genetic deficient mice, we examined the relative contribution of calpain isoforms in AngII-induced ascending and abdominal AA development. Methodology/Results To investigate the relative contribution of calpain-1 and -2 in development of AngII-induced AAs, male LDLr −/− mice that were either calpain-1 +/+ or −/− were fed a saturated fat-enriched diet and infused with AngII (1,000 ng/kg/min) for 4 weeks. Calpain-1 deficiency had no significant effect on body weight or blood pressure during AngII infusion. Moreover, calpain-1 deficiency showed no discernible effects on AngII-induced ascending and abdominal AAs. Interestingly, AngII infusion induced increased expression of calpain-2 protein, thus compensating for total calpain activity in aortas of calpain-1 deficient mice. Oral administration of BDA-410, a calpain inhibitor, along with AngII-infusion significantly attenuated AngII-induced ascending and abdominal AA formation in both calpain-1 +/+ and −/− mice as compared to vehicle administered mice. Furthermore, BDA-410 administration attenuated AngII-induced aortic medial hypertrophy and macrophage accumulation. Western blot and immunostaining analyses revealed BDA-410 administration attenuated AngII-induced C-terminal fragmentation of filamin A, an actin binding cytoskeletal protein in aorta. Conclusion Calpain-2 compensates for loss of calpain-1, and both calpain isoforms are involved in AngII-induced aortic aneurysm formation in mice

Expression of chemokine receptors CXCR1 and CXCR2 during cardiopulmonary bypass

AbstractObjective: This study investigated the effects of cardiopulmonary bypass on neutrophil expression of chemokine receptors, CXCR1 and CXCR2, and the β2 integrin CD11b. Methods: Ten patients undergoing coronary artery grafting with cardiopulmonary bypass were studied. Blood samples were collected preoperatively, before bypass, at termination of bypass, and 12 to 18 hours postoperatively. In vitro studies were performed on control subjects to determine changes in the surface expression of CXCR1, CXCR2, and CD11b on stimulation with interleukin 8. Receptor expression was measured by flow cytometry. Plasma levels of interleukin 8 from the patients were determined by enzyme-linked immunoassay. Results: After bypass, CXCR2 expression fell by 66% (P <.0001) and remained low postoperatively (P <.0001). CXCR1 expression persisted at preoperative levels. CD11b expression increased significantly after bypass (P <.0001), returning to prebypass levels postoperatively. In vitro studies showed a dose-related fall of both CXCR1 (P <.0001) and CXCR2 expression (P <.0001) and a significant rise in CD11b expression (P <.0001). Plasma interleukin 8 increased significantly after bypass (P <.0001), remaining elevated 12 to 18 hours postoperatively (P =.02). Correlations between interleukin 8 levels and CXCR2 expression (P <.0001) and CD11b expression (P <.03) were demonstrated. Conclusions: CXCR2 expression is significantly down-regulated after bypass; in contrast, CXCR1 expression remains unchanged. In addition, whereas interleukin 8 is an important determinant of both CXCR1 and CXCR2 expression in vitro, it only correlates with CXCR2 and CD11b expression in vivo. This has implications in the search for antagonists against CXC chemokines and their receptor

Calpain-1 knockout reveals broad effects on erythrocyte deformability and physiology

Pharmacological inhibitors of cysteine proteases have provideduseful insights into the regulation of calpain activity inerythrocytes. However, the precise biological function of calpainactivity in erythrocytes remains poorly understood. Erythrocytesexpress calpain-1, an isoform regulated by calpastatin, theendogenous inhibitor of calpains. In the present study, weinvestigated the function of calpain-1 in mature erythrocytes usingour calpain-1-null [KO (knockout)] mouse model. The calpain-1gene deletion results in improved erythrocyte deformabilitywithout any measurable effect on erythrocyte lifespan in vivo.The calcium-induced sphero-echinocyte shape transition iscompromised in the KO erythrocytes. Erythrocyte membraneproteins ankyrin, band 3, protein 4.1R, adducin and dematin aredegraded in the calcium-loaded normal erythrocytes but not inthe KO erythrocytes. In contrast, the integrity of spectrin andits state of phosphorylation are not affected in the calciumloadederythrocytes of either genotype. To assess the functionalconsequences of attenuated cytoskeletal remodelling in the KOerythrocytes, the activity of major membrane transporters wasmeasured. The activity of the K+\u2013Cl 12 co-transporter and theGardos channel was significantly reduced in the KO erythrocytes.Similarly, the basal activity of the calcium pump was reducedin the absence of calmodulin in the KO erythrocyte membrane.Interestingly, the calmodulin-stimulated calcium pump activitywas significantly elevated in the KO erythrocytes, implying awider range of pump regulation by calcium and calmodulin. Takentogether, and with the atomic force microscopy of the skeletalnetwork, the results of the present study provide the first evidencefor the physiological function of calpain-1 in erythrocytes withtherapeutic implications for calcium imbalance pathologies suchas sickle cell disease

A closer look at the increase in suicide rates in South Korea from 1986–2005

<p>Abstract</p> <p>Background</p> <p>Suicide rates have recently been decreasing on average among OECD countries, but increasing trends have been detected in South Korea, particularly since the 1997 economic crisis. There have been no detailed analyses about the changes of the suicide rates over time periods in Korea. We examined trends in both absolute and proportional suicide rates over the time period of economic development, crisis, and recovery (1986 – 2005) as well as in birth cohorts from 1924 to 1978.</p> <p>Methods</p> <p>We used data on total mortality and suicide rates from 1986 to 2005 published online by the Korean National Statistical Office (NSO) and extracted data for individuals under 80 years old. The analyses of the trends for 1) the sex-age-specific total mortality rate, 2) the sex-age-specific suicide rate, and 3) the sex-age-specific proportional suicide rate in 1986–2005 were conducted. To demonstrate the birth cohort effect on the proportional suicide rate, the synthetic birth cohort from 1924 to 1978 from the successive cross-sectional data was constructed.</p> <p>Results</p> <p>Age standardized suicide rates in South Korea increased by 98% in men (from 15.3 to 30.3 per 100,000) and by 124% in women (from 5.8 to 13.0 per 100,000). In both genders, the proportional increase in suicide rates was more prominent among the younger group aged under 45, despite the absolute increase being attributed to the older group. There were distinct cohort effects underlying increasing suicide rates particularly among younger age groups.</p> <p>Conclusion</p> <p>Increasing suicide rates in Korea was composed of a greater absolute increase in the older group and a greater proportional increase in the younger group.</p

Fracture Risk in Men With Congestive Heart Failure Risk Reduction With Spironolactone

ObjectivesThe purpose of this study was to determine whether spironolactone use is associated with fractures in men with congestive heart failure (CHF).BackgroundIn rats with aldosteronism, spironolactone preserves skeletal strength. However, in humans, the relationship of spironolactone to fractures is not known.MethodsThe medical records of all male patients with CHF from 1999 to 2005 treated at the Veterans Affairs Medical Center, Memphis, Tennessee, were reviewed (n = 4,735). Odds ratios with 95% confidence intervals of having a fracture associated with spironolactone use were estimated using conditional logistic regression.ResultsWe identified 167 cases with a single-incident fracture and matched these by age and race to 668 control subjects without fractures. After adjustment for covariates, spironolactone use was inversely associated with total fracture (odds ratio: 0.575; 95% confidence interval: 0.346 to 0.955, p = 0.0324).ConclusionsThe use of spironolactone is inversely associated with fractures in men with CHF

MicroRNA-Related Cofilin Abnormality in Alzheimer's Disease

Rod-like structures composed of actin and the actin-binding protein cofilin are found in Alzheimer's disease (AD) patients. However, the mechanisms underlying formation of these structures and their pathological consequences are still largely unknown. We found that microRNAs 103 and 107 repress translation of cofilin, and that reduced levels of miR-103 or miR-107 are associated with elevated cofilin protein levels and formation of rod-like structures in a transgenic mouse model of AD. These results suggest that microRNAs may play an important role in cytoskeletal pathology in AD

Utilisation of an operative difficulty grading scale for laparoscopic cholecystectomy

Background A reliable system for grading operative difficulty of laparoscopic cholecystectomy would standardise description of findings and reporting of outcomes. The aim of this study was to validate a difficulty grading system (Nassar scale), testing its applicability and consistency in two large prospective datasets. Methods Patient and disease-related variables and 30-day outcomes were identified in two prospective cholecystectomy databases: the multi-centre prospective cohort of 8820 patients from the recent CholeS Study and the single-surgeon series containing 4089 patients. Operative data and patient outcomes were correlated with Nassar operative difficultly scale, using Kendall’s tau for dichotomous variables, or Jonckheere–Terpstra tests for continuous variables. A ROC curve analysis was performed, to quantify the predictive accuracy of the scale for each outcome, with continuous outcomes dichotomised, prior to analysis. Results A higher operative difficulty grade was consistently associated with worse outcomes for the patients in both the reference and CholeS cohorts. The median length of stay increased from 0 to 4 days, and the 30-day complication rate from 7.6 to 24.4% as the difficulty grade increased from 1 to 4/5 (both p < 0.001). In the CholeS cohort, a higher difficulty grade was found to be most strongly associated with conversion to open and 30-day mortality (AUROC = 0.903, 0.822, respectively). On multivariable analysis, the Nassar operative difficultly scale was found to be a significant independent predictor of operative duration, conversion to open surgery, 30-day complications and 30-day reintervention (all p < 0.001). Conclusion We have shown that an operative difficulty scale can standardise the description of operative findings by multiple grades of surgeons to facilitate audit, training assessment and research. It provides a tool for reporting operative findings, disease severity and technical difficulty and can be utilised in future research to reliably compare outcomes according to case mix and intra-operative difficulty

Fast-timing measurements in ⁹⁶Pd:improved accuracy for the lifetime of the 4⁺₁ state

Direct lifetime measurements via γ–γ coincidences using the FATIMA fast-timing LaBr3(Ce) array were performed for the excited states below previously reported isomers. In the N = 50 semi-magic 96Pd nucleus, lifetimes below the I π = 8+ seniority isomer were addressed as a benchmark for further analysis. The results for the I π = 2+ and 4 + states confirm the published values. Increased accuracy for the lifetime value was achieved for the 4 + state.peerReviewe