bluuebunny/crossref_metadata_2025 huggingface dataset:
Long-Term Histologic Changes and Effects of Perichondrium Preservation of Auricular Cartilage Grafted in Rabbit Tympanic Bullae
Authors: Tu Tzong-Yang
Published: September 2012

Introduction: This study evaluated the long-term histologic changes of grafted auricular cartilage in rabbit tympanic bullae. Materials and Methods: Auricular cartilage with or without perichondrium was prepared and cut into small pieces to obliterate the rabbit tympanic bullae. The histologic changes of the grafted cartilage in both groups were compared 20 months after surgery. Results: Remarkable spongy bony trabeculae of mature lamellar bone with red bone marrow formation were observed in the perichondrium-preserved group. Parts of the grafted cartilage pieces were invaded and replaced by bone and bone marrow. The grafted cartilage pieces grossly maintained their original polygonal shapes, and no osteochondral tissue regeneration was observed in the perichondrium-removed group. The viable chondrocyte ratios were 46.21 ± 5.58 versus 27.80 ± 4.81%, and the minimal resorption ratios were 10.31 ± 3.27 versus 2.98 ± 1.48% in the perichondrium-preserved (n = 14) and -removed groups (n = 12, p < 0.05). The tissue ratios were cartilage: 38.18 ± 8.76 versus 52.97 ± 9.30%; lamellar bone: 18.49 ± 5.31 versus 0.82 ± 0.43%; bone marrow: 20.72 ± 6.27 versus 0.00 ± 0.00%; fibrous tissue: 10.13 ± 2.74 versus 5.81 ± 2.20%, and adipose tissue: 12.01 ± 4.48 versus 40.70 ± 7.83% in the perichondrium-preserved and -removed groups. The differences were all statistically significant (p < 0.05). Conclusion: A space-filling mass effect with minimal resorption of the cartilage pieces was observed in the perichondrium-removed group. In addition to this mass effect, the progenitor cells in the preserved perichondrium allowed active bone tissue regeneration and cartilage resorption in the perichondrium-preserved group.
Inflammation Modulates Murine Venous Thrombosis Resolution In Vivo
Authors: Ripplinger Crystal M. , Kessinger Chase W. , Li Chunqiang , Kim Jin Won , McCarthy Jason R. , Weissleder Ralph , Henke Peter K. , Lin Charles P. , Jaffer Farouc A.
Published: September 2012

Objective—

Assessment of thrombus inflammation in vivo could provide new insights into deep vein thrombosis (DVT) resolution. Here, we develop and evaluate 2 integrated fluorescence molecular-structural imaging strategies to quantify DVT-related inflammation and architecture and to assess the effect of thrombus inflammation on subsequent DVT resolution in vivo.

Methods and Results—

Murine DVT were created with topical 5% FeCl
3
application to thigh or jugular veins (n=35). On day 3, mice received macrophage and matrix metalloproteinase activity fluorescence imaging agents. On day 4, integrated assessment of DVT inflammation and architecture was performed using confocal fluorescence intravital microscopy. Day 4 analyses showed robust relationships among in vivo thrombus macrophages, matrix metalloproteinase activity, and fluorescein isothiocyanate-dextran deposition (
r
>0.70;
P
<0.01). In a serial 2–time point study, mice with DVT underwent intravital microscopy at day 4 and day 6. Analyses revealed that the intensity of thrombus inflammation at day 4 predicted the magnitude of DVT resolution at day 6 (
P
<0.05). In a second approach, noninvasive fluorescence molecular tomography-computed tomography was used and detected macrophages within jugular DVT (
P
<0.05 versus sham controls).

Conclusion—

Integrated fluorescence molecular-structural imaging demonstrates that the DVT-induced inflammatory response can be readily assessed in vivo and can inform the magnitude of thrombus resolution.
Atorvastatin Delays Murine Platelet Activation In Vivo Even in the Absence of Endothelial NO Synthase
Authors: Ni Ran , Peleg Tal , Gross Peter L.
Published: September 2012

Objective—

Statins decrease mortality in patients with vascular disorders, and evidence for the pleiotropic effects of statins is accumulating. Statins enhance endothelial NO synthase (eNOS) expression, thereby attenuating platelet activation and thrombus formation. Our goal was to determine whether statins have eNOS-independent effects on platelet activation.

Methods and Results—

Wild-type and eNOS-deficient mice were given a 14-day course of oral atorvastatin, and platelet activation was evaluated in vitro and in vivo. Whereas in wild-type mice atorvastatin inhibited platelet activation in vitro in response to numerous agonists, in eNOS-deficient mice, atorvastatin inhibited only thrombin-induced and protease-activated receptor 4 agonist peptide–induced platelet activation. Consistent with an eNOS-independent effect, atorvastatin inhibited platelet activation in vivo in both wild-type and eNOS-deficient mice.

Conclusion—

Atorvastatin inhibits platelet activation via eNOS-dependent and eNOS-independent mechanisms with the latter restricted to protease-activated receptor 4-induced activation downstream to the receptor.
Upregulation of a Disintegrin and Metalloproteinase With Thrombospondin Motifs-7 by miR-29 Repression Mediates Vascular Smooth Muscle Calcification
Authors: Du Yaoyao , Gao Cheng , Liu Ziyi , Wang Li , Liu Bo , He Fan , Zhang Tao , Wang Yue , Wang Xiujie , Xu Mingjiang , Luo Guan-Zheng , Zhu Yi , Xu Qingbo , Wang Xian , Kong Wei
Published: September 2012

Objective—

Vascular calcification significantly increases cardiovascular morbidity and mortality. We recently reported that the deficiency of cartilage oligomeric matrix protein (COMP) leads to vascular mineralization. We characterized the COMP-degrading metalloproteinase, a disintegrin and metalloproteinase with thrombospondin motifs-7 (ADAMTS-7). Here, we tested whether ADAMTS-7 facilitates vascular calcification.

Methods and Results—

ADAMTS-7 expression was markedly upregulated in calcifying rat vascular smooth muscle cells (VSMCs) in vitro, calcified arteries of rats with chronic renal failure in vivo, and radial arteries of uraemic patients. Silencing of ADAMTS-7 markedly reduced COMP degradation and ameliorated VSMC calcification, whereas ectopic expression of ADAMTS-7 greatly enhanced COMP degradation and exacerbated mineralization. The transcriptional activity of ADAMTS-7 promoter was not altered by high phosphate. We used bioinformatics and quantitative polymerase chain reaction analysis to demonstrate that high-phosphate upregulated ADAMTS-7 mRNA and protein via miR-29a/b repression, which directly targeted the 3′ untranslated region of ADAMTS-7 in VSMCs. MicroRNA (MiR)-29a/b mimic markedly inhibited but miR-29a/b inhibitor greatly enhanced high-phosphate–induced ADAMTS-7 expression, COMP degradation, and subsequent VSMC calcification. ADAMTS-7 silencing significantly diminished miR-29a/b repression–exaggerated VSMC calcification.

Conclusion—

Our data reveal a novel mechanism by which ADAMTS-7 upregulation by miR-29a/b repression mediates vascular calcification, which may shed light on preventing cardiovascular morbidity and mortality.
Genetic and Pharmacological Inhibition of Dimethylarginine Dimethylaminohydrolase 1 Is Protective in Endotoxic Shock
Authors: Nandi Manasi , Kelly Peter , Torondel Belen , Wang Zhen , Starr Anna , Ma Yue , Cunningham Philip , Stidwill Raymond , Leiper James
Published: September 2012

Objective—

The overproduction of vascular NO contributes toward the circulatory collapse observed in patients with septic shock. Dimethylarginine dimethylaminohydrolase (DDAH), which has 2 isoforms, metabolizes asymmetrically methylated arginines (asymmetric mono- or di-methylarginine), endogenously produced NO synthase inhibitors. We wished to investigate whether reducing DDAH1 activity, using genetic and pharmacological approaches, is protective during lipopolysaccharide-induced endotoxic shock.

Methods and Results—

Experiments were conducted in DDAH1 heterozygous knockout mice (DDAH1
+/−
) or naive rats treated with a synthetic pharmacological DDAH inhibitor (L-257). We demonstrate for the first time that L-257 is DDAH1 selective using recombinant human DDAH proteins. DDAH1 mRNA was expressed in aortic but not macrophage cDNA, and consistent with this expression profile, L-257 selectively inhibited NO production from lipopolysaccharide-treated aorta but not macrophages, in culture. Conscious and anesthetized cardiovascular hemodynamics were monitored using implanted radiotelemetry devices or invasive catheters, respectively. Lipopolysaccharide was administered intravenously to model endotoxemia, and all animals presented with circulatory shock. DDAH1
+/−
mice or L-257–treated rats displayed attenuation in the rate of developed hypotension compared with wild-type littermates or vehicle control animals, respectively.

Conclusion—

Pharmacological and genetic reduction of DDAH1 activity is protective against the vascular changes observed during endotoxic shock.
Trafficking of Endogenous Smooth Muscle Cell Cholesterol
Authors: Pessolano Lawrence G. , Sullivan Christopher P. , Seidl Stephanie E. , Rich Celeste B. , Liscum Laura , Stone Phillip J. , Sipe Jean D. , Schreiber Barbara M.
Published: September 2012

Objective—

Intracellular cholesterol distribution impacts cell function; however, processes influencing endogenous cholesterol trafficking remain largely unknown. Atherosclerosis is associated with vascular inflammation and these studies address the role of inflammatory mediators on smooth muscle cell cholesterol trafficking.

Methods and Results—

Interestingly, in the absence of an exogenous cholesterol source, serum amyloid A increased [
14
C] oleic acid incorporation into cholesteryl ester in rat smooth muscle cells, suggesting endogenous cholesterol trafficking to the endoplasmic reticulum. [
3
H] cholesteryl ester accumulated in cells prelabeled with [
3
H] cholesterol, confirming that serum amyloid A mediated the movement of endogenous cholesterol. Cholesterol movement was dependent upon functional endolysosomes. The cholesterol oxidase–sensitive pool of cholesterol decreased in serum amyloid A−treated cells. Furthermore, the mechanism whereby serum amyloid A induced cholesterol trafficking was determined to be via activation of expression of secretory phospholipase A
2
, group IIA (sPLA
2
) and sPLA
2
–dependent activation of sphingomyelinase. Interestingly, although neither tumor necrosis factor-α nor interferon-γ induced cholesterol trafficking, interleukin-1β induced [
14
C] cholesteryl ester accumulation that was also dependent upon sPLA
2
and sphingomyelinase activities. Serum amyloid A activates smooth muscle cell interleukin-1β expression, and although the interleukin-1–receptor antagonist inhibited the interleukin-1β−induced cholesterol trafficking, it had no effect on the movement of cholesterol mediated by serum amyloid A.

Conclusion—

These data support a role for inflammation in endogenous smooth muscle cell cholesterol trafficking from the plasma membrane to the endoplasmic reticulum.
Endogenous IRAK-M Attenuates Postinfarction Remodeling Through Effects on Macrophages and Fibroblasts
Authors: Chen Wei , Saxena Amit , Li Na , Sun Jinyu , Gupta Amit , Lee Dong-Wook , Tian Qi , Dobaczewski Marcin , Frangogiannis Nikolaos G.
Published: September 2012

Objective—

Effective postinfarction repair requires timely suppression of innate immune signals to prevent the catastrophic consequences of uncontrolled inflammation on cardiac geometry and function. In macrophages, interleukin-1 receptor-associated kinase (IRAK)-M acts as a functional decoy preventing uncontrolled toll-like receptor /interleukin-1–mediated responses. Our study investigates the role of IRAK-M as a negative regulator of the postinfarction inflammatory response and as a modulator of cardiac remodeling.

Methods and Results—

In wild-type mouse infarcts IRAK-M was upregulated in infiltrating macrophages and fibroblasts exhibiting a biphasic response. When compared with wild-type animals, infarcted IRAK-M
−/−
mice had enhanced adverse remodeling and worse systolic dysfunction; however, acute infarct size was comparable between groups. Adverse remodeling in IRAK-M
−/−
animals was associated with enhanced myocardial inflammation and protease activation. The protective actions of IRAK-M involved phenotypic modulation of macrophages and fibroblasts. IRAK-M
−/−
infarcts showed increased infiltration with proinflammatory CD11b+/Ly6C
hi
monocytes; leukocytes harvested from IRAK-M−null infarcts exhibited accentuated cytokine expression. In vitro, IRAK-M expression was upregulated in cytokine-stimulated murine cardiac fibroblasts and suppressed their matrix-degrading properties without affecting their inflammatory activity.

Conclusion—

Endogenous IRAK-M attenuates adverse postinfarction remodeling suppressing leukocyte inflammatory activity, while inhibiting fibroblast-mediated matrix degradation.
Expression of the Irisin Precursor FNDC5 in Skeletal Muscle Correlates With Aerobic Exercise Performance in Patients With Heart Failure
Authors: Lecker Stewart H. , Zavin Alexandra , Cao Peirang , Arena Ross , Allsup Kelly , Daniels Karla M. , Joseph Jacob , Schulze P. Christian , Forman Daniel E.
Published: September 2012

Background—

Exercise-induced increase in peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) expression has been shown to increase the expression of the fibronectin type III domain containing 5 (
FNDC5
) gene and thereby its product, irisin, in mice. Given that exercise intolerance is a hallmark characteristic of heart failure (HF), and because PGC-1α and irisin promote exercise benefits in animals, we hypothesized that expression of these genes relates to aerobic performance in patients with HF.

Methods and Results—

Systolic HF (left ventricular ejection fraction ≤40%) patients underwent cardiopulmonary exercise testing to evaluate aerobic performance. High versus low aerobic performance was assessed using oxygen consumption (peak V
o
2
[>14 versus ≤14 mL O
2
·kg
−1
·min
−1
]) and ventilatory efficiency (VE/V
co
2
slope [<34 versus ≥34]). Muscle biopsies of the vastus lateralis and real-time polymerase chain reaction were used to quantify muscle gene expression. Twenty-four patients were studied. FNDC5 (5.7±3.5 versus 3.1±1.2,
P<0
.05) and PGC-1α (9.9±5.9 versus 4.5±1.9,
P
<0.01) gene expressions were greater in the high-peak V
o
2
group; correlation between FNDC5 and PGC-1α was significant (
r
=0.56,
P
<0.05) only in the high-peak V
o
2
group. Similarly, FNDC5 and PGC-1α gene expression was greater in the high-performance group based on lower VE/V
co
2
slopes (5.8±3.6 versus 3.3±1.4,
P
<0.05 and 9.7±6 versus 5.3±3.4,
P
<0.05); FNDC5 also correlated with PGC-1α (
r
=0.55,
P
<0.05) only in the low VE/V
co
2
slope group.

Conclusions—

This is the first study to show that FNDC5 expression relates to functional capacity in a human HF population. Lower FNDC5 expression may underlie reduced aerobic performance in HF patients.
Anchored p90 Ribosomal S6 Kinase 3 Is Required for Cardiac Myocyte Hypertrophy
Authors: Li Jinliang , Kritzer Michael D. , Michel Jennifer J. Carlisle , Le Andrew , Thakur Hrishikesh , Gayanilo Marjorie , Passariello Catherine L. , Negro Alejandra , Danial Joshua B. , Oskouei Behzad , Sanders Michael , Hare Joshua M. , Hanauer Andre , Dodge-Kafka Kimberly , Kapiloff Michael S.
Published: September 2012

Rationale:

Cardiac myocyte hypertrophy is the main compensatory response to chronic stress on the heart. p90 ribosomal S6 kinase (RSK) family members are effectors for extracellular signal-regulated kinases that induce myocyte growth. Although increased RSK activity has been observed in stressed myocytes, the functions of individual RSK family members have remained poorly defined, despite being potential therapeutic targets for cardiac disease.

Objective:

To demonstrate that type 3 RSK (RSK3) is required for cardiac myocyte hypertrophy.

Methods and Results:

RSK3 contains a unique N-terminal domain that is not conserved in other RSK family members. We show that this domain mediates the regulated binding of RSK3 to the muscle A-kinase anchoring protein scaffold, defining a novel kinase anchoring event. Disruption of both RSK3 expression using RNA interference and RSK3 anchoring using a competing muscle A-kinase anchoring protein peptide inhibited the hypertrophy of cultured myocytes. In vivo, RSK3 gene deletion in the mouse attenuated the concentric myocyte hypertrophy induced by pressure overload and catecholamine infusion.

Conclusions:

Taken together, these data demonstrate that anchored RSK3 transduces signals that modulate pathologic myocyte growth. Targeting of signaling complexes that contain select kinase isoforms should provide an approach for the specific inhibition of cardiac myocyte hypertrophy and for the development of novel strategies for the prevention and treatment of heart failure.
Rapid Estrogen Receptor Signaling Is Essential for the Protective Effects of Estrogen Against Vascular Injury
Authors: Bernelot Moens Sophie J. , Schnitzler Gavin R. , Nickerson Moriah , Guo Huiming , Ueda Kazutaka , Lu Qing , Aronovitz Mark J. , Nickerson Heather , Baur Wendy E. , Hansen Ulla , Iyer Lakshmanan K. , Karas Richard H.
Published: September 2012

Background—

Clinical trial and epidemiological data support that the cardiovascular effects of estrogen are complex, including a mixture of both potentially beneficial and harmful effects. In animal models, estrogen protects females from vascular injury and inhibits atherosclerosis. These effects are mediated by estrogen receptors (ERs), which, when bound to estrogen, can bind to DNA to directly regulate transcription. ERs can also activate several cellular kinases by inducing a rapid nonnuclear signaling cascade. However, the biological significance of this rapid signaling pathway has been unclear.

Methods and Results—

In the present study, we develop a novel transgenic mouse in which rapid signaling is blocked by overexpression of a peptide that prevents ERs from interacting with the scaffold protein striatin (the disrupting peptide mouse). Microarray analysis of ex vivo treated mouse aortas demonstrates that rapid ER signaling plays an important role in estrogen-mediated gene regulatory responses. Disruption of ER-striatin interactions also eliminates the ability of estrogen to stimulate cultured endothelial cell migration and to inhibit cultured vascular smooth muscle cell growth. The importance of these findings is underscored by in vivo experiments demonstrating loss of estrogen-mediated protection against vascular injury in the disrupting peptide mouse after carotid artery wire injury.

Conclusions—

Taken together, these results support the concept that rapid, nonnuclear ER signaling contributes to the transcriptional regulatory functions of ER and is essential for many of the vasoprotective effects of estrogen. These findings also identify the rapid ER signaling pathway as a potential target for the development of novel therapeutic agents.
A Randomized, Placebo‐Controlled Trial of Omega‐3 Fatty Acids for Inhibition of Supraventricular Arrhythmias After Cardiac Surgery: The FISH Trial
Authors: Sandesara Chirag M. , Chung Mina K. , Van Wagoner David R. , Barringer Thomas A. , Allen Keith , Ismail Hassan M. , Zimmerman Bridget , Olshansky Brian
Published: September 2012

Background

Omega‐3 polyunsaturated fatty acids (n3‐PUFAs) might have antiarrhythmic properties, but data conflict on whether n3‐PUFAs reduce rates of atrial fibrillation (AF) after coronary artery bypass graft surgery (CABG). We hypothesized that n3‐PUFAs would reduce post‐CABG AF, and we tested this hypothesis in a well‐powered, randomized, double‐blind, placebo‐controlled, multicenter clinical trial.

Methods and Results

Patients undergoing CABG were randomized to pharmaceutical‐grade n3‐PUFAs 2 g orally twice daily (minimum of 6 g) or a matched placebo ≥24 hours before surgery. Gas chromatography was used to assess plasma fatty acid composition of samples collected on the day of screening, day of surgery, and postoperative day 4. Treatment continued either until the primary end point, clinically significant AF requiring treatment, occurred or for a maximum of 2 weeks after surgery. Two hundred sixty patients were enrolled and randomized. Before surgery, n3‐PUFA dosing increased plasma n3‐PUFA levels from 2.9% to 4% and reduced the n6:n3‐PUFA ratio from 9.1 to 6.4 (both
P
<0.001). Similar changes were noted on postoperative day 4. There were no lipid changes in the placebo group. The rate of post‐CABG AF was similar in both groups (30% n3‐PUFAs versus 33% placebo,
P
=0.67). The post‐CABG AF odds ratio for n3‐PUFAs relative to placebo was 0.89 (95% confidence interval 0.52–1.53). There were no differences in any secondary end points.

Conclusions

Oral n3‐PUFA supplementation begun 2 days before CABG did not reduce AF or other complications after surgery.

Clinical Trial Registration

URL:
www.clinicaltrials.gov
Unique identifier: NCT00446966.

(
J Am Heart Assoc
. 2012;1:e000547 doi: 10.1161/JAHA.111.000547.)
Reduction of Long‐Term Care Dependence After an 8‐Year Primary Care Prevention Program for Stroke and Dementia: The INVADE Trial
Authors: Bickel Horst , Ander Karl‐Heinz , Brönner Monika , Etgen Thorleif , Gnahn Hans , Gotzler Othma , Poppert Holger , Pürner Klaus , Sander Dirk , Förstl Hans
Published: September 2012

Background

Stroke and dementia are the major causes for long‐term care (
LTC
) dependence in old age. This intervention trial compared a multidomain prevention program for stroke and dementia with usual medical care in reducing the need for
LTC
.

Methods and Results

The Intervention Project on Cerebrovascular Disease and Dementia in the District of Ebersberg (
INVADE
) was a general practice–based 8‐year trial in 2 defined catchment areas in Upper Bavaria, Germany. All 11 317 insurants of a statutory health insurance plan who were ≥55 years of age and lived in the intervention district were offered the opportunity to participate in a prevention program; 3908 enrolled. The 13 301 insurants in the reference district received usual medical care. The intervention consisted of the systematic identification and evidence‐based treatment of vascular risk factors. The primary clinical end point was incidence of
LTC
dependence according to external assessment by a special medical service in the framework of the statutory German
LTC
insurance. Age‐ and sex‐specific incidence rates from the reference district were used to calculate the expected number of cases of
LTC
dependence under usual medical care. The expected number was compared with the observed number of cases in the intervention district. Analysis was by intention to treat. During the 5 years after completion of the recruitment period, significantly fewer incident cases of
LTC
dependence arose in the intervention district than expected (χ
2
=13.25;
P<
0.001). In women, the incidence was reduced by 10% (
P<
0.01). In men, the incidence was reduced by 9.6% (
P<
0.05).

Conclusions

Our results support the feasibility and effectiveness of a primary care prevention program for stroke and dementia to reduce the risk of developing
LTC
dependence.

Clinical Trial Registration

URL
:
http://www.clinicaltrials.gov
. Unique identifier:
NCT
01107548. (

J Am Heart Assoc.

2012;1: e000786 doi: 10.1161/
JAHA
.112.000786.)
Histone Deacetylase Activity Selectively Regulates Notch‐Mediated Smooth Muscle Differentiation in Human Vascular Cells
Authors: Tang Yuefeng , Boucher Joshua M. , Liaw Lucy
Published: September 2012

Background

Histone deacetylases (HDACs) modify smooth muscle cell (SMC) proliferation and affect neointimal lesion formation by regulating cell cycle progression. HDACs might also regulate SMC differentiation, although this is not as well characterized.

Methods and Results

Notch signaling activates SMC contractile markers and the differentiated phenotype in human aortic SMCs. Using this model, we found that HDAC inhibition antagonized the ability of Notch to increase levels of smooth muscle α‐actin, calponin1, smooth muscle 22α, and smooth muscle myosin heavy chain. However, inhibition of HDAC activity did not suppress Notch activation of the HRT target genes. In fact, HDAC inhibition increased activation of the canonical C‐promoter binding factor‐1 (CBF‐1)–mediated Notch pathway, which activates HRT transcription. Although CBF‐1–mediated Notch signaling was increased by HDAC inhibition in human SMCs and in a C3H10T1/2 model, SMC differentiation was inhibited in both cases. Further characterization of downstream Notch signaling pathways showed activation of the c‐Jun N‐terminal kinase, p38 mitogen‐activated protein kinase, and PI3K/Akt pathways. The activation of these pathways was sensitive to HDAC inhibition and was positively correlated with the differentiated phenotype.

Conclusions

Our studies define novel signaling pathways downstream of Notch signaling in human SMCs. In addition to the canonical CBF‐1 pathway, Notch stimulates c‐Jun N‐terminal kinase, mitogen‐activated protein kinase, and PI3K cascades. Both canonical and noncanonical pathways downstream of Notch promote a differentiated, contractile phenotype in SMCs. Although CBF‐1–mediated Notch signaling is not suppressed by HDAC inhibition, HDAC activity is required for Notch differentiation signals through mitogen‐activated protein kinase and PI3K pathways in SMCs.

(
J Am Heart Assoc
. 2012;1:e000901 doi

:
10.1161/JAHA.112.000901
)
CaMK4 Gene Deletion Induces Hypertension
Authors: Santulli Gaetano , Cipolletta Ersilia , Sorriento Daniela , Del Giudice Carmine , Anastasio Antonio , Monaco Sara , Maione Angela Serena , Condorelli Gianluigi , Puca Annibale , Trimarco Bruno , Illario Maddalena , Iaccarino Guido
Published: September 2012

Background

The expression of calcium/calmodulin‐dependent kinase IV (
CaMKIV
) was hitherto thought to be confined to the nervous system. However, a recent genome‐wide analysis indicated an association between hypertension and a single‐nucleotide polymorphism (
rs10491334
) of the human
CaMKIV
gene (

CaMK4

)
, which suggests a role for this kinase in the regulation of vascular tone.

Methods and Results

To directly assess the role of
CaMKIV
in hypertension, we characterized the cardiovascular phenotype of

CaMK4

−/−
mice. They displayed a typical hypertensive phenotype, including high blood pressure levels, cardiac hypertrophy, vascular and kidney damage, and reduced tolerance to chronic ischemia and myocardial infarction compared with wild‐type littermates. Interestingly, in vitro experiments showed the ability of this kinase to activate endothelial nitric oxide synthase. Eventually, in a population study, we found that the
rs10491334
variant associates with a reduction in the expression levels of
CaMKIV
in lymphocytes from hypertensive patients.

Conclusions

Taken together, our results provide evidence that
CaMKIV
plays a pivotal role in blood pressure regulation through the control of endothelial nitric oxide synthase activity.
Trends in Clinical, Demographic, and Biochemical Characteristics of Patients With Acute Myocardial Infarction From 2003 to 2008: A Report From the American Heart Association Get With The Guidelines Coronary Artery Disease Program
Authors: Boyer Nathan M. , Laskey Warren K. , Cox Margueritte , Hernandez Adrian F. , Peterson Eric D. , Bhatt Deepak L. , Cannon Christopher P. , Fonarow Gregg C.
Published: September 2012

Background

An analysis of the changes in the clinical and demographic characteristics of patients with acute myocardial infarction could identify successes and failures of risk factor identification and treatment of patients at increased risk for cardiovascular events.

Methods and Results

We reviewed data collected from 138 122 patients with acute myocardial infarction admitted from 2003 to 2008 to hospitals participating in the American Heart Association Get With The Guidelines Coronary Artery Disease program. Clinical, demographic, and laboratory characteristics were analyzed for each year stratified on the electrocardiogram at presentation. Patients with non–
ST
‐segment–elevation myocardial infarction were older, more likely to be women, and more likely to have hypertension, diabetes mellitus, and a history of past cardiovascular disease than were patients with ST‐elevation myocardial infarction. In the overall patient sample, significant trends were observed of an increase over time in the proportions of non–ST‐segment–elevation myocardial infarction, patient age of 45 to 65 years, obesity, and female sex. The prevalence of diabetes mellitus decreased over time, whereas the prevalences of hypertension and smoking were substantial and unchanging. The prevalence of “low” high‐density lipoprotein increased over time, whereas that of “high” low‐density lipoprotein decreased. Stratum‐specific univariate analysis revealed quantitative and qualitative differences between strata in time trends for numerous demographic, clinical, and biochemical measures. On multivariable analysis, there was concordance between strata with regard to the increase in prevalence of patients 45 to 65 years of age, obesity, and “low” high‐density lipoprotein and the decrease in prevalence of “high” low‐density lipoprotein. However, changes in trends in age distribution, sex ratio, and prevalence of smokers and the magnitude of change in diabetes mellitus prevalence differed between strata.

Conclusions

There were notable differences in risk factors and patient characteristics among patients with ST‐elevation myocardial infarction and those with non–ST‐segment–elevation myocardial infarction. The increasing prevalence of dysmetabolic markers in a growing proportion of patients with acute myocardial infarction suggests further opportunities for risk factor modification.
Mild Sensory Stimulation Protects the Aged Rodent From Cortical Ischemic Stroke After Permanent Middle Cerebral Artery Occlusion
Authors: Lay Christopher C. , Davis Melissa F. , Chen‐Bee Cynthia H. , Frostig Ron D.
Published: September 2012

Background

Accumulated research has shown that the older adult brain is significantly more vulnerable to stroke than the young adult brain. Although recent evidence in young adult rats demonstrates that single‐whisker stimulation can result in complete protection from ischemic damage after permanent middle cerebral artery occlusion (
pMCAO
), it remains unclear whether the same treatment would be effective in older animals.

Methods and Results

Aged rats (21 to 24 months of age) underwent
pMCAO
and subsequently were divided into “treated” and “untreated” groups. Treated aged rats received intermittent single‐whisker stimulation during a 120‐minute period immediately after
pMCAO
, whereas untreated aged rats did not. These animals were assessed using a battery of behavioral tests 1 week before and 1 week after
pMCAO
, after which their brains were stained for infarct. An additional treated aged group and a treated young adult group also were imaged with functional imaging. Results demonstrated that the recovery of treated aged animals was indistinguishable from that of the treated young adult animals. Treated aged rats had fully intact sensorimotor behavior and no infarct, whereas untreated aged rats were impaired and sustained cortical infarct.

Conclusions

Taken together, our results confirm that single‐whisker stimulation is protective in an aged rodent
pMCAO
model, despite age‐associated stroke vulnerability. These findings further suggest potential for translation to the more clinically relevant older adult human population.
High Level of Plasma Estradiol as a New Predictor of Ischemic Arterial Disease in Older Postmenopausal Women: The Three‐City Cohort Study
Authors: Scarabin‐Carré Valérie , Canonico Marianne , Brailly‐Tabard Sylvie , Trabado Séverine , Ducimetière Pierre , Giroud Maurice , Ryan Joanne , Helmer Catherine , Plu‐Bureau Geneviève , Guiochon‐Mantel Anne , Scarabin Pierre‐Yves
Published: September 2012

Background

Despite evidence that estrogens may be involved in atherothrombosis, the role of endogenous sex steroid hormones in ischemic arterial disease among postmenopausal women remains uncertain.

Methods and Results

In the Three‐City prospective cohort study of subjects (n=9294) >65 years of age, we investigated the association of total 17β‐estradiol, bioavailable 17β‐estradiol, and total testosterone with the 4‐year incidence of ischemic arterial disease among postmenopausal women who did not use any hormone therapy. We designed a case–cohort study including a random sample of 537 subjects and 106 incident cases of first cardiovascular events. Weighted Cox proportional‐hazards models with age as the time scale were used to estimate hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) for ischemic arterial disease by a 1–standard deviation increase in sex steroid hormones. In univariate analysis, HR of ischemic arterial disease was positively and significantly associated with both total and bioavailable estradiol levels. These associations remained significant after adjustment for traditional cardiovascular risk factors, including body mass index, diabetes, hypercholesterolemia, hypertension, and smoking status (HR: 1.42, 95% CI: 1.12–1.79,
P
<0.01; and HR: 1.42, 95% CI: 1.12–1.78,
P
<0.01, respectively). Separate analysis for coronary heart disease yielded similar results (adjusted HR: 1.49, 95% CI: 1.10–2.02,
P
=0.01; and adjusted HR: 1.50, 95% CI: 1.11–2.04,
P
<0.01, respectively), and a borderline significant trend was observed for ischemic stroke (HR: 1.34, 95% CI: 0.95–1.89,
P
=0.08; and HR: 1.32, 95% CI: 0.94–1.84,
P
=0.11, respectively). By contrast, no significant association was found between total testosterone and ischemic arterial disease in both univariate and adjusted analyses.

Conclusions

High plasma level of endogenous estradiol emerges as a new predictor of ischemic arterial disease in older postmenopausal women.

(
J Am Heart Assoc
. 2012;1:e001388 doi

:
10.1161/JAHA.112.001388
.)
Changes in Carotid Intima‐Media Thickness During the Cardiac Cycle: The Multi‐Ethnic Study of Atherosclerosis
Authors: Polak Joseph F. , Johnson Craig , Harrington Anita , Wong Quenna , O'Leary Daniel H. , Burke Gregory , Yanez N. David
Published: September 2012

Background

Common carotid artery intima‐media thickness (
IMT
), a measure of subclinical cardiovascular disease, changes during the cardiac cycle. The magnitude of this effect and its implications have not been well studied.

Methods and Results

Far‐wall
IMT
measurements of the right common carotid artery were measured at end diastole and peak systole in 5633 individuals from the Multi‐Ethnic Study of Atherosclerosis (
MESA
). Multivariable regression models were generated with end‐diastolic
IMT
, peak‐systolic
IMT
, and change in
IMT
during the cardiac cycle as dependent variables and traditional cardiovascular risk factors as independent variables. The average age of our population was 61.9 (45 to 84) years. Average change in carotid
IMT
during the cardiac cycle was 0.041 mm (95% confidence interval: 0.039 to 0.042 mm), with a mean
IMT
of 0.68 mm. End‐diastolic
IMT
and peak‐systolic
IMT
were similarly associated with risk factors. In a fully adjusted model, change in carotid
IMT
during the cardiac cycle was associated with ethnicity and pulse pressure (
P
=0.001) and not age, sex, or other risk factors. Chinese and Hispanics had less of a change in
IMT
than did non‐Hispanic whites. With peak‐systolic
IMT
reference values used as normative data, 31.3% more individuals were classified as being in the upper quartile of
IMT
and at high risk for cardiovascular disease than would be expected when
IMT
is measured at end diastole.

Conclusions

Measurable differences in
IMT
are seen during the cardiac cycle. This affects the interpretation of
IMT
measurements used for cardiovascular risk assessment, given published normative data with
IMT
measured at peak systole.

Clinical Trial Registration

URL:
www.ClinicalTrials.gov
. Unique identifier: NCT00063440.
Vulnerable Myocardial Interstitium in Patients With Isolated Left Ventricular Hypertrophy and Sudden Cardiac Death: A Postmortem Histological Evaluation
Authors: Tamarappoo Balaji K. , John Benjamin T. , Reinier Kyndaron , Teodorescu Carmen , Uy‐Evanado Audrey , Gunson Karen , Jui Jonathan , Chugh Sumeet S.
Published: September 2012

Background

Concentric left ventricular hypertrophy (LVH) is independently associated with increased risk of sudden cardiac death (SCD). Some animal models of LVH display specific alterations of the myocardial interstitium that could increase myocardial vulnerability to ventricular arrhythmias, but these merit evaluation in humans with LVH and SCD.

Methods and Results

Twelve consecutive patients with isolated LVH and SCD (LVH+SCD) in the absence of hypertrophic cardiomyopathy, coronary disease, or other cardiac structural abnormality were ascertained in the Oregon Sudden Unexpected Death Study. Detailed postmortem comparisons were conducted with 18 controls who had isolated LVH and unnatural deaths (Control Group A) and 6 controls who had structurally normal hearts and unnatural deaths (Control Group B). Postmortem left ventricular myocardial sections were obtained for measurement of collagen volume fraction, characterization of gap junctions, and quantification of collagen subtypes. Heart weight normalized to body weight was higher in LVH+SCD cases (6.9±1.2 g/kg) than in Control Group A (5.3±1.4 g/kg) and Control Group B (4.2±0.3 g/kg);
P
=0.001. Collagen volume fraction was also higher in LVH+SCD cases (3.1±0.4) than in Control Group A (2.3±0.4) and Control Group B (1.6±0.3);
P
=0.0002. The relative amount of collagen III was significantly higher in LVH+SCD cases (33.0±4.4%) than in Control Group A (20.9±4.3%) and Control Group B (13.4±3.5%);
P
=0.0001. There was an overall increase in the number of connexin 43–labeled gap junctions with increasing myocyte size. No subject was found to have high‐risk hypertrophic cardiomyopathy mutations.

Conclusions

In addition to the expected increase in myocardial mass and overall collagen content, SCD with isolated LVH was associated with relative abundance of type III collagen, a novel finding that warrants further mechanistic evaluation.

(
J Am Heart Assoc
. 2012;1:e001511 doi

:
10.1161/JAHA.112.001511
.)
Risk of Idiopathic Dilated Cardiomyopathy in 29 000 Patients With Celiac Disease
Authors: Emilsson Louise , Andersson Bert , Elfström Peter , Green Peter H.R. , Ludvigsson Jonas F.
Published: September 2012

Background

Dilated cardiomyopathy (DCM) is a rare disease of largely unknown origin. Previous studies have suggested an increased prevalence of celiac disease (CD) in patients with DCM. These studies, however, were based on a maximum of 5 patients with both CD and DCM. In the present large Swedish population‐based cohort study, we examined the risk of idiopathic DCM in patients with CD determined by small‐intestinal histopathology.

Methods and Results

From 2006 to 2008, we collected duodenal/jejunal biopsy data on CD (equal to villous atrophy, Marsh stage 3, n=29 071 unique individuals) from (all) 28 pathology departments in Sweden. These individuals were compared with 144 429 reference individuals matched for age, sex, calendar year, and county. Data on DCM were obtained through the National Patient Register and confirmed by patient charts and echocardiography data. During follow‐up, 17 patients with CD and 52 reference individuals developed idiopathic DCM. Thus, patients with CD were at an increased risk of idiopathic DCM (hazard ratio, 1.73; 95% confidence interval, 1.00 to 3.00), although the risk estimate failed to attain statistical significance (
P
=0.052).

Conclusion

This nationwide study found a moderately but not statistically significantly increased risk of idiopathic DCM in patients with biopsy‐verified CD.

(
J Am Heart Assoc
. 2012;1:e001594 doi

:
10.1161/JAHA.112.001594
.)
Reduction of Ischemia/Reperfusion Injury With Bendavia, a Mitochondria‐Targeting Cytoprotective Peptide
Authors: Kloner Robert A. , Hale Sharon L. , Dai Wangde , Gorman Robert C. , Shuto Takashi , Koomalsingh Kevin J. , Gorman Joseph H. , Sloan Ruben C. , Frasier Chad R. , Watson Corinne A. , Bostian Phillip A. , Kypson Alan P. , Brown David A.
Published: September 2012

Background

Manifestations of reperfusion injury include myocyte death leading to infarction, contractile dysfunction, and vascular injury characterized by the “no‐reflow” phenomenon. Mitochondria‐produced reactive oxygen species are believed to be centrally involved in each of these aspects of reperfusion injury, although currently no therapies reduce reperfusion injury by targeting mitochondria specifically.

Methods and Results

We investigated the cardioprotective effects of a mitochondria‐targeted peptide, Bendavia (Stealth Peptides), across a spectrum of experimental cardiac ischemia/reperfusion models. Postischemic administration of Bendavia reduced infarct size in an in vivo sheep model by 15% (
P
=0.02) and in an ex vivo guinea pig model by 38% to 42% (
P
<0.05). In an in vivo rabbit model, the extent of coronary no‐reflow was assessed with Thioflavin S staining and was significantly smaller in the Bendavia group for any given ischemic risk area than in the control group (
P
=0.0085). Myocardial uptake of Bendavia was ≈25% per minute, and uptake remained consistent throughout reperfusion. Postischemic recovery of cardiac hemodynamics was not influenced by Bendavia in any of the models studied. Isolated myocytes exposed to hypoxia/reoxygenation showed improved survival when treated with Bendavia. This protection appeared to be mediated by lowered reactive oxygen species–mediated cell death during reoxygenation, associated with sustainment of mitochondrial membrane potential in Bendavia‐treated myocytes.

Conclusions

Postischemic administration of Bendavia protected against reperfusion injury in several distinct models of injury. These data suggest that Bendavia is a mitochondria‐targeted therapy that reduces reperfusion injury by maintaining mitochondrial energetics and suppressing cellular reactive oxygen species levels.

(
J Am Heart Assoc
. 2012;1:e001644 doi

:
10.1161/JAHA.112.001644
.)
Measurement of Reverse Cholesterol Transport Pathways in Humans: In Vivo Rates of Free Cholesterol Efflux, Esterification, and Excretion
Authors: Turner Scott , Voogt Jason , Davidson Michael , Glass Alex , Killion Salena , Decaris Julie , Mohammed Hussein , Minehira Kaori , Boban Drina , Murphy Elizabeth , Luchoomun Jayraz , Awada Mohamad , Neese Richard , Hellerstein Marc
Published: September 2012

Background

Reverse cholesterol transport from peripheral tissues is considered the principal atheroprotective mechanism of high‐density lipoprotein, but quantifying reverse cholesterol transport in humans in vivo remains a challenge. We describe here a method for measuring flux of cholesterol though 3 primary components of the reverse cholesterol transport pathway in vivo in humans: tissue free cholesterol (
FC
) efflux, esterification of
FC
in plasma, and fecal sterol excretion of plasma‐derived
FC
.

Methods and Results

A constant infusion of [2,3‐
13
C
2
]‐cholesterol was administered to healthy volunteers. Three‐compartment
SAAM
 
II
(Simulation, Analysis, and Modeling software; SAAM Institute, University of Washington, WA) fits were applied to plasma
FC
, red blood cell
FC
, and plasma cholesterol ester
13
C–enrichment profiles. Fecal sterol excretion of plasma‐derived
FC
was quantified from fractional recovery of intravenous [2,3‐
13
C
2
]‐cholesterol in feces over 7 days. We examined the key assumptions of the method and evaluated the optimal clinical protocol and approach to data analysis and modeling. A total of 17 subjects from 2 study sites (n=12 from first site, age 21 to 75 years, 2 women; n=5 from second site, age 18 to 70 years, 2 women) were studied. Tissue
FC
efflux was 3.79±0.88 mg/kg per hour (mean ± standard deviation), or ≈8 g/d. Red blood cell–derived flux into plasma
FC
was 3.38±1.10 mg/kg per hour. Esterification of plasma
FC
was ≈28% of tissue
FC
efflux (1.10±0.38 mg/kg per hour). Recoveries were 7% and 12% of administered [2,3‐
13
C
2
]‐cholesterol in fecal bile acids and neutral sterols, respectively.

Conclusions

Three components of systemic reverse cholesterol transport can be quantified, allowing dissection of this important function of high‐density lipoprotein in vivo. Effects of lipoproteins, genetic mutations, lifestyle changes, and drugs on these components can be assessed in humans.
Interleukin‐1 Mediates Neuroinflammatory Changes Associated With Diet‐Induced Atherosclerosis
Authors: Denes Adam , Drake Caroline , Stordy Jing , Chamberlain Janet , McColl Barry W. , Gram Hermann , Crossman David , Francis Sheila , Allan Stuart M. , Rothwell Nancy J.
Published: September 2012

Background

Systemic inflammation contributes to brain pathology in cerebrovascular disease through mechanisms that are poorly understood.

Methods and Results

Here we show that atherosclerosis, a major systemic inflammatory disease, is associated with severe cerebrovascular inflammation in mice and that this effect is mediated by the proinflammatory cytokine interleukin‐1 (IL‐1). Apolipoprotein E–deficient mice fed Paigen or Western diets develop vascular inflammation, microglial activation, and leukocyte recruitment in the brain, which are absent in apolipoprotein E–deficient mice crossed with IL‐1 type 1 receptor–deficient mice. Systemic neutralization of IL‐1β with an anti–IL‐1β antibody reversed aortic plaque formation (by 34% after a Paigen and 45% after a Western diet) and reduced inflammatory cytokine expression in peripheral organs. Central, lipid accumulation–associated leukocyte infiltration into the choroid plexus was reversed by IL‐1β antibody administration. Animals fed a Western diet showed 57% lower vascular inflammation in the brain than that of mice fed a Paigen diet, and this was reduced further by 24% after IL‐1β antibody administration.

Conclusions

These results indicate that IL‐1 is a key driver of systemically mediated cerebrovascular inflammation and that interventions against IL‐1β could be therapeutically useful in atherosclerosis, dementia, or stroke.

(
J Am Heart Assoc
. 2012;1:e002006 doi

:
10.1161/JAHA.112.002006
.)