83 research outputs found
Bazedoxifene, a selective estrogen receptor modulator, reduces cerebral aneurysm rupture in Ovariectomized rats.
BackgroundEstrogen deficiency is thought to be responsible for the higher frequency of aneurysmal subarachnoid hemorrhage in post- than premenopausal women. Estrogen replacement therapy appears to reduce this risk but is associated with significant side effects. We tested our hypothesis that bazedoxifene, a clinically used selective estrogen receptor (ER) modulator with fewer estrogenic side effects, reduces cerebral aneurysm rupture in a new model of ovariectomized rats.MethodsTen-week-old female Sprague-Dawley rats were subjected to ovariectomy, hemodynamic changes, and hypertension to induce aneurysms (ovariectomized aneurysm rats) and treated with vehicle or with 0.3 or 1.0 mg/kg/day bazedoxifene. They were compared with sham-ovariectomized rats subjected to hypertension and hemodynamic changes (HT rats). The vasoprotective effects of bazedoxifene and the mechanisms underlying its efficacy were analyzed.ResultsDuring 12 weeks of observation, the incidence of aneurysm rupture was 52% in ovariectomized rats. With no effect on the blood pressure, treatment with 0.3 or 1.0 mg/kg/day bazedoxifene lowered this rate to 11 and 17%, almost the same as in HT rats (17%). In ovariectomized rats, the mRNA level of ERα, ERβ, and the tissue inhibitor of metalloproteinase-2 was downregulated in the cerebral artery prone to rupture at 5 weeks after aneurysm induction; the mRNA level of interleukin-1β and the matrix metalloproteinase-9 was upregulated. In HT rats, bazedoxifene restored the mRNA level of ERα and ERβ and decreased the level of interleukin-1β and matrix metalloproteinase-9. These findings suggest that bazedoxifene was protective against aneurysmal rupture by alleviating the vascular inflammation and degradation exacerbated by the decrease in ERα and ERβ.ConclusionsOur observation that bazedoxifene decreased the incidence of aneurysmal rupture in ovariectomized rats warrants further studies to validate this response in humans
Proteomic analysis of proteins expressing in regions of rat brain by a combination of SDS-PAGE with nano-liquid chromatography-quadrupole-time of flight tandem mass spectrometry
選択的エストロゲン受容体モジュレーターのバゼドキシフェンは卵巣摘除ラットにおいて脳動脈瘤破裂を抑制する
Background: Estrogen deficiency is thought to be responsible for the higher frequency of aneurysmal subarachnoid hemorrhage in post- than premenopausal women. Estrogen replacement therapy appears to reduce this risk but is associated with significant side effects. We tested our hypothesis that bazedoxifene, a clinically used selective estrogen receptor (ER) modulator with fewer estrogenic side effects, reduces cerebral aneurysm rupture in a new model of ovariectomized rats.
Methods: Ten-week-old female Sprague-Dawley rats were subjected to ovariectomy, hemodynamic changes, and hypertension to induce aneurysms (ovariectomized aneurysm rats) and treated with vehicle or with 0.3 or 1.0 mg/kg/day bazedoxifene. They were compared with sham-ovariectomized rats subjected to hypertension and hemodynamic changes (HT rats). The vasoprotective effects of bazedoxifene and the mechanisms underlying its efficacy were analyzed.
Results: During 12 weeks of observation, the incidence of aneurysm rupture was 52% in ovariectomized rats. With no effect on the blood pressure, treatment with 0.3 or 1.0 mg/kg/day bazedoxifene lowered this rate to 11 and 17%, almost the same as in HT rats (17%). In ovariectomized rats, the mRNA level of ERα, ERβ, and the tissue inhibitor of metalloproteinase-2 was downregulated in the cerebral artery prone to rupture at 5 weeks after aneurysm induction; the mRNA level of interleukin-1β and the matrix metalloproteinase-9 was upregulated. In HT rats, bazedoxifene restored the mRNA level of ERα and ERβ and decreased the level of interleukin-1β and matrix metalloproteinase-9. These findings suggest that bazedoxifene was protective against aneurysmal rupture by alleviating the vascular inflammation and degradation exacerbated by the decrease in ERα and ERβ.
Conclusions: Our observation that bazedoxifene decreased the incidence of aneurysmal rupture in ovariectomized rats warrants further studies to validate this response in humans
Complement-Dependent Mechanisms and Interventions in Periodontal Disease
Periodontitis is a prevalent inflammatory disease that leads to the destruction of the tooth-supporting tissues. Current therapies are not effective for all patients and this oral disease continues to be a significant public health and economic burden. Central to periodontal disease pathogenesis is a reciprocally reinforced interplay between microbial dysbiosis and destructive inflammation, suggesting the potential relevance of host-modulation therapies. This review summarizes and discusses clinical observations and pre-clinical intervention studies that collectively suggest that complement is hyperactivated in periodontitis and that its inhibition provides a therapeutic benefit. Specifically, interception of the complement cascade at its central component, C3, using a locally administered small peptidic compound (Cp40/AMY-101) protected non-human primates from induced or naturally occurring periodontitis. These studies indicate that C3-targeted intervention merits investigation as an adjunctive treatment of periodontal disease in humans
Secreted protein Del-1 regulates myelopoiesis in the hematopoietic stem cell niche
Hematopoietic stem cells (HSCs) remain mostly quiescent under steady-state conditions but switch to a proliferative state following hematopoietic stress, e.g., bone marrow (BM) injury, transplantation, or systemic infection and inflammation. The homeostatic balance between quiescence, self-renewal, and differentiation of HSCs is strongly dependent on their interactions with cells that constitute a specialized microanatomical environment in the BM known as the HSC niche. Here, we identified the secreted extracellular matrix protein Del-1 as a component and regulator of the HSC niche. Specifically, we found that Del-1 was expressed by several cellular components of the HSC niche, including arteriolar endothelial cells, CXCL12-abundant reticular (CAR) cells, and cells of the osteoblastic lineage. Del-1 promoted critical functions of the HSC niche, as it regulated long-term HSC (LT-HSC) proliferation and differentiation toward the myeloid lineage. Del-1 deficiency in mice resulted in reduced LT-HSC proliferation and infringed preferentially upon myelopoiesis under both steady-state and stressful conditions, such as hematopoietic cell transplantation and G-CSF- or inflammation-induced stress myelopoiesis. Del-1-induced HSC proliferation and myeloid lineage commitment were mediated by β3 integrin on hematopoietic progenitors. This hitherto unknown Del-1 function in the HSC niche represents a juxtacrine homeostatic adaptation of the hematopoietic system in stress myelopoiesis
Cbl-b DEFICIENCY AND MACROPHAGE ACTIVATION
We previously reported the potential involvement of casitas B-cell lymphoma-b (Cbl-b) in aging-related murine insulin resistance. Because obesity also induces macrophage recruitment into adipose tissue, we elucidated here the role of Cbl-b in obesity-related insulin resistance. Cbl-b+/+ and Cbl-b-/- mice were fed a high-fat diet (HFD) and then examined for obesity-related changes in insulin signaling. The HFD caused recruitment of macrophages into adipose tissue and increased inflammatory reaction in Cbl-b-/- compared with Cbl-b+/+ mice. Peritoneal macrophages from Cbl-b-/- mice and Cbl-b–overexpressing RAW264.7 macrophages were used to examine the direct effect of saturated fatty acids (FAs) on macrophage activation. In macrophages, Cbl-b suppressed saturated FA-induced Toll-like receptor 4 (TLR4) signaling by ubiquitination and degradation of TLR4. The physiological role of Cbl-b in vivo was also examined by bone marrow transplantation and Eritoran, a TLR4 antagonist. Hematopoietic cell-specific depletion of the Cbl-b gene induced disturbed responses on insulin and glucose tolerance tests. Blockade of TLR4 signaling by Eritoran reduced fasting blood glucose and serum interleukin-6 levels in obese Cbl-b-/- mice. These results suggest that Cbl-b deficiency could exaggerate HFD-induced insulin resistance through saturated FA-mediated macrophage activation. Therefore, inhibition of TLR4 signaling is an attractive therapeutic strategy for treatment of obesity-related insulin resistance
Chronic Oral Infection with Porphyromonas gingivalis Accelerates Atheroma Formation by Shifting the Lipid Profile
BACKGROUND: Recent studies have suggested that periodontal disease increases the risk of atherothrombotic disease. Atherosclerosis has been characterized as a chronic inflammatory response to cholesterol deposition in the arteries. Although several studies have suggested that certain periodontopathic bacteria accelerate atherogenesis in apolipoprotein E-deficient mice, the mechanistic link between cholesterol accumulation and periodontal infection-induced inflammation is largely unknown. METHODOLOGY/PRINCIPAL FINDINGS: We orally infected C57BL/6 and C57BL/6.KOR-Apoe(shl) (B6.Apoeshl) mice with Porphyromonas gingivalis, which is a representative periodontopathic bacterium, and evaluated atherogenesis, gene expression in the aorta and liver and systemic inflammatory and lipid profiles in the blood. Furthermore, the effect of lipopolysaccharide (LPS) from P. gingivalis on cholesterol transport and the related gene expression was examined in peritoneal macrophages. Alveolar bone resorption and elevation of systemic inflammatory responses were induced in both strains. Despite early changes in the expression of key genes involved in cholesterol turnover, such as liver X receptor and ATP-binding cassette A1, serum lipid profiles did not change with short-term infection. Long-term infection was associated with a reduction in serum high-density lipoprotein (HDL) cholesterol but not with the development of atherosclerotic lesions in wild-type mice. In B6.Apoeshl mice, long-term infection resulted in the elevation of very low-density lipoprotein (VLDL), LDL and total cholesterols in addition to the reduction of HDL cholesterol. This shift in the lipid profile was concomitant with a significant increase in atherosclerotic lesions. Stimulation with P. gingivalis LPS induced the change of cholesterol transport via targeting the expression of LDL receptor-related genes and resulted in the disturbance of regulatory mechanisms of the cholesterol level in macrophages. CONCLUSIONS/SIGNIFICANCE: Periodontal infection itself does not cause atherosclerosis, but it accelerates it by inducing systemic inflammation and deteriorating lipid metabolism, particularly when underlying hyperlidemia or susceptibility to hyperlipidemia exists, and it may contribute to the development of coronary heart disease
Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).
Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and ≥1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (n = 5069) or prospectively (n = 5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (≤6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; p = 0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)
Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.
BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362
Seismic Exploration Using Active Sources at Kuchierabujima Volcano, Southwest Japan
Seismic exploration using artificial sources was conducted at Kuchierabujima volcano, southwest Japan in November 2004 by 40 participants from 9 national universities andJapan Meteorological Agency to investigate the subsurface seismic structure. The exploration was the 11th joint experiment under the National Project for Prediction of Volcanic Eruptions. A total of 183 temporal stations equippedwith a 2 Hz vertical component seismometer (including 75 3component seismometers) and a portable data logger were deployed on Kuchierabu Island. Dynamite shots with charges of 10-115 kg were detonated at 19 locations, and seismic signals were successfully recorded. To reveal the P-wave velocity structure, 2955 arrival times of the first motion were picked from the seismograms, and 2187 were classified into ranks A and B. From the record sections and the arrival time data, characteristics reflecting the geological structure were identified. Refracted waves of 5 km/s were observed at stations>5km from the shot points. Apparent velocities near the shot points depend on the surface geology around the shots. P-wave arrived earlier at stations near the summits. Strongly scattered waves were observed similarly near the summits
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