Inhibition of Intrinsic Interferon-γ Function Prevents Neointima Formation After Balloon Injury

Kusaba, Ken; Kai, Hisashi; Koga, Mitsuhisa; Takayama, Narimasa; Ikeda, Ayami; Yasukawa, Hideo; Seki, Yukihiko; Egashira, Kensuke; Imaizumi, Tsutomu

doi:10.1161/01.hyp.0000259668.37901.8c

Cited by 29 publications

(25 citation statements)

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“…11 Total RNA was extracted from the frozen hearts (n¼7 per group per time point) using TRIzol (Invitrogen). 20,21 Aliquots of total RNA were reverse transcribed and amplified in triplicate using the SYBER PrimeScript RT-PCR kit (TAKARA BIO, Kyoto, Japan) and a Sequence Detection System Model 7700 (Applied Biosystems, Foster city, CA, USA).…”

Section: Morphometry and Immunohistostainingmentioning

confidence: 99%

Enhanced cardiac inflammation and fibrosis in ovariectomized hypertensive rats: a possible mechanism of diastolic dysfunction in postmenopausal women

et al. 2011

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Diastolic dysfunction is more prevalent in individuals with hypertension, particularly postmenopausal women; however, the pathogenesis of diastolic dysfunction remains unknown. Pressure overload activates cardiac inflammation, which induces myocardial fibrosis and diastolic dysfunction in rats with a suprarenal aortic constriction (AC). Therefore, we examined the effects of bilateral ovariectomy (OVX) on left ventricle (LV) remodeling, diastolic dysfunction and cardiac inflammation in hypertensive female rats. Rats were randomized to OVX+AC, OVX and AC groups as well as a Control group receiving sham operations for both the procedures. Rats underwent OVX at 6 weeks and AC at 10 weeks (Day 0). At Day 28, OVX did not appear to affect arterial pressure, cardiac hypertrophy or LV fractional shortening in AC rats. However, OVX increased myocardial fibrosis, elevated LV end-diastolic pressure and reduced the transmitral Doppler spectra early to late filling velocity ratio in AC rats. AC-induced transient myocardial monocyte chemoattractant protein-1 expression and macrophage infiltration, both of which peaked at Day 3 and were augmented and prolonged by OVX. At Day 28, dihydroethidium staining revealed superoxide generation in the intramyocardial arterioles in the OVX+AC group but not in the AC group. NOX1, a functional subunit of nicotinamide adenine dinucleotide phosphate oxidase, was upregulated only in the OVX+AC group at Day 28. Chronic 17b-estradiol replacement prevented the increases in macrophage infiltration, NOX1 upregulation, myocardial fibrosis and diastolic dysfunction in OVX+AC rats. In conclusion, we suggest that estrogen deficiency augments cardiac inflammation and oxidative stress and thereby aggravates myocardial fibrosis and diastolic dysfunction in hypertensive female rats. The findings provide insight into the mechanism underlying diastolic dysfunction in hypertensive postmenopausal women. Hypertension Research (2011) 34, 496-502; doi:10.1038/hr.2010; published online 20 January 2011Keywords: estradiol; gender medicine; macrophage; myocardial fibrosis; oxidative stress INTRODUCTIONThe ejection fraction of the left ventricle (LV) is normal in approximately half of all patients with congestive heart failure, which indicates that impaired diastolic function in these patients is the major cause of heart failure. [1][2][3] Hypertension is the most common coexisting disease in patients with diastolic heart failure. Diastolic heart failure is more prevalent in women than in men, especially in postmenopausal hypertensive women, which may be due to decreased estrogen levels. 2,3 Determinants of diastolic function include active myocardial relaxation and passive properties of the LV wall. 2 Sequestration of calcium and cross-bridge uncoupling after systole are involved in the active process of relaxation. Previous studies have shown that estrogen

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Section: Morphometry and Immunohistostainingmentioning

confidence: 99%

Enhanced cardiac inflammation and fibrosis in ovariectomized hypertensive rats: a possible mechanism of diastolic dysfunction in postmenopausal women

et al. 2011

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“…Total RNA was extracted and reverse-transcribed as described previously. 26 Equal amounts of the resulting cDNA were subjected to real-time PCR for rat brain natriuretic peptide (BNP), rat type 1 procollagen, rat transforming growth facto (TGF-b) and rat monocyte chemoattractant protein (MCP)-1. 23,27 Expression levels of the target genes were normalized to GAPDH.…”

Section: Real-time Reverse-transcription Pcr Analysismentioning

confidence: 99%

Simvastatin prevents large blood pressure variability induced aggravation of cardiac hypertrophy in hypertensive rats by inhibiting RhoA/Ras–ERK pathways

et al. 2010

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Pronounced variability in blood pressure (BP) is an aggravating factor of hypertensive end-organ damage. However, its pathogenesis remains unknown. Statins have various protective effects on the cardiovascular system. Thus, we determined whether simvastatin would attenuate the aggravation of hypertensive cardiac remodeling in a rat model of hypertension with large BP variability, and also investigated the signaling mechanism involved in its effect. A model of hypertension with large BP variability was created by performing bilateral sinoaortic denervation (SAD) in spontaneously hypertensive rats (SHRs). A SAD or sham operation was performed in 12-week-old rats. Thereafter, simvastatin (0.2 mg kg À1 per day) or vehicle was intraperitoneally administered every day. After 6 weeks , telemetric recordings revealed that SAD enhanced BP variability without changing the mean BP. SAD increased myocyte hypertrophy, myocardial fibrosis and macrophage infiltration associated with the upregulation of brain natriuretic peptide (BNP), type I procollagen, transforming growth factor (TGF)-b and monocyte chemoattractant protein (MCP)-1, and activation of RhoA, Ras and ERK1/2. Simvastatin did not change the mean BP or BP variability in SAD-operated SHRs. In SAD-operated SHRs, simvastatin attenuated myocyte hypertrophy and BNP expression, as well as RhoA, Ras and ERK1/2 activities. In contrast, simvastatin did not change myocardial fibrosis, macrophage infiltration, or the expression of procollagen and TGF-b or MCP-1 in SAD-operated SHRs. Simvastatin did not affect serum lipid levels. In conclusion, simvastatin attenuated the large BP variability-induced aggravation of cardiac hypertrophy, but not myocardial fibrosis, in SHRs. The activation of RhoA/Ras-ERK pathways may contribute to the aggravation of cardiac hypertrophy by a combination of hypertension and large BP variability.

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“…Total RNA was extracted and reverse transcribed, as described previously. 27 Equal amounts of the resulting cDNA were subjected to real-time PCR for rat MCP-1, rat TGF-␤, and rat angiotensinogen. 17,28 The expression level of the target gene was normalized by the GAPDH level in each sample.…”

Section: Real-time Rt-pcr Analysismentioning

confidence: 99%

Exaggerated Blood Pressure Variability Superimposed on Hypertension Aggravates Cardiac Remodeling in Rats via Angiotensin II System-Mediated Chronic Inflammation

et al. 2009

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Abstract-Hypertensive patients with large blood pressure variability (BPV) have aggravated end-organ damage.However, the pathogenesis remains unknown. We investigated whether exaggerated BPV aggravates hypertensive cardiac remodeling and function by activating inflammation and angiotensin II-mediated mechanisms. A model of exaggerated BPV superimposed on chronic hypertension was created by performing bilateral sinoaortic denervation (SAD) in spontaneously hypertensive rats (SHRs). SAD increased BPV to a similar extent in Wistar Kyoto rats and SHRs without significant changes in mean blood pressure. SAD aggravated left ventricular and myocyte hypertrophy and myocardial fibrosis to a greater extent and impaired left ventricular systolic function in SHRs. SAD induced monocyte chemoattractant protein-1, transforming growth factor-␤, and angiotensinogen mRNA upregulations and macrophage infiltration of the heart in SHRs. The effects of SAD on cardiac remodeling and inflammation were much smaller in Wistar Kyoto rats compared with SHRs. Circulating levels of norepinephrine, the active form of renin, and inflammatory cytokines were not affected by SAD in Wistar Kyoto rats and SHRs. A subdepressor dose of candesartan abolished the SAD-induced left ventricular/myocyte hypertrophy, myocardial fibrosis, macrophage infiltration, and inductions of monocyte chemoattractant protein-1, transforming growth factor-␤, and angiotensinogen and subsequently prevented systolic dysfunction in SHRs with SAD. These findings suggest that exaggerated BPV induces chronic myocardial inflammation and thereby aggravates cardiac remodeling and systolic function in hypertensive hearts. The cardiac angiotensin II system may play a role in the pathogenesis of cardiac remodeling and dysfunction induced by a combination of hypertension and exaggerated BPV. Key Words: blood pressure variability Ⅲ hypertension Ⅲ inflammation Ⅲ angiotensin II Ⅲ cardiac hypertrophy T he goal of hypertension treatment is not only to reduce blood pressure (BP) levels but also to prevent cardiovascular events. Among hypertensive patients, patients with large BP variability (BPV) have more advanced end-organ damage, such as left ventricular (LV) hypertrophy and carotid atherosclerosis. [1][2][3][4][5][6][7] Recent studies have shown that exaggerated BPV is a risk factor for cardiovascular events in hypertensive patients, 8 -10 independent of diurnal BP changes. 11 An exaggerated BPV is a characteristic feature of hypertension, especially in the elderly and in patients with carotid atherosclerosis. 12-14 However, little is known about the mechanism underlying the aggravation of end-organ damage induced by a combination of hypertension and large BPV aggravates.Our recent studies have shown that perivascular inflammation plays a pivotal role in hypertensive cardiac remodeling, especially in myocardial fibrosis (for review see References 15 and 16): in Wistar Kyoto rats (WKYs) with suprarenal aortic constriction, BP elevation induces perivascular inflammation characterized by ...

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Inhibition of Intrinsic Interferon-γ Function Prevents Neointima Formation After Balloon Injury

Cited by 29 publications

References 35 publications

Enhanced cardiac inflammation and fibrosis in ovariectomized hypertensive rats: a possible mechanism of diastolic dysfunction in postmenopausal women

Enhanced cardiac inflammation and fibrosis in ovariectomized hypertensive rats: a possible mechanism of diastolic dysfunction in postmenopausal women

Simvastatin prevents large blood pressure variability induced aggravation of cardiac hypertrophy in hypertensive rats by inhibiting RhoA/Ras–ERK pathways

Exaggerated Blood Pressure Variability Superimposed on Hypertension Aggravates Cardiac Remodeling in Rats via Angiotensin II System-Mediated Chronic Inflammation

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