MD, National Defense Medical College (2007)
PhD, Keio University (2019)
Marlene Rabinovitch, Postdoctoral Faculty Sponsor
Glucocorticoid receptor (GR) is abundantly expressed in cardiomyocytes. However, the role of GR in regulating cardiac hypertrophy and heart failure in response to pressure overload remains unclear. Cardiomyocyte-specific GR knockout (GRcKO) mice, mineralocorticoid receptor (MR) knockout (MRcKO), and GR and MR double KO (GRMRdcKO) mice were generated using the Cre-lox system. In response to pressure overload, GRcKO mice displayed worse cardiac remodeling compared to control (GRf/f) mice, including a greater increase in heart weight to body weight ratio with a greater increase in cardiomyocytes size, a greater decline in left ventricular contractility, and higher reactivation of fetal genes. MRcKO mice showed a comparable degree of cardiac remodeling compared to control (MRf/f) mice. The worse cardiac remodeling in pressure overloaded GRcKO mice is not due to compensatory activation of cardiomyocyte MR, since pressure overloaded GRMRdcKO mice displayed cardiac remodeling to the same extent as GRcKO mice. Pressure overload suppressed GR-target gene expression in the heart. Although plasma corticosterone levels and subcellular localization of GR (nuclear/cytoplasmic GR) were not changed, a chromatin immunoprecipitation assay revealed that GR recruitment onto the promoter of GR-target genes was significantly suppressed in response to pressure overload. Rescue of the expression of GR-target genes to the same extent as sham-operated hearts attenuated adverse cardiac remodeling in pressure-overloaded hearts. Thus, GR works as a repressor of adverse cardiac remodeling in response to pressure overload, but GR-mediated transcription is suppressed under pressure overload. Therapies that maintain GR-mediated transcription in cardiomyocytes under pressure overload can be a promising therapeutic strategy for heart failure.
View details for DOI 10.1016/j.yjmcc.2019.03.019
View details for PubMedID 30946837
Balloon pulmonary angioplasty (BPA) has emerged as an effective treatment for patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH). Renal function has been identified as a prognostic marker in patients with pulmonary hypertension in previous studies. We, therefore, aimed to investigate the clinical parameters associated with improvements in renal function in patients with CTEPH. A total of 45 consecutive patients with inoperable CTEPH undergoing BPA (mean age 62.2 ± 15.1 years) were included in the study. We evaluated the patients' clinical characteristics at baseline and at 1-year post-BPA, and investigated the association between renal function and hemodynamic parameters, including right heart function. Hemodynamics and renal function showed sustained improvements at 1 year after BPA in 64.4% of patients. Improved estimated glomerular filtration rate (eGFR) was significantly correlated with increased cardiac index (r = 0.433, p = 0.003) and mixed venous oxygen saturation (SvO2; r = 0.459, p = 0.002), and with decreased mean pulmonary arterial pressure (r = - 0.420, p = 0.004) and pulmonary vascular resistance (r = -- 0.465, p = 0.001). Multivariate analysis revealed that an increase in SvO2 immediately after the final BPA was associated with improved eGFR after the 1st year (odds ratio 1.041; 95% confidence interval 1.004-1.078; P = 0.027). The cut-off value for predicting improved eGFR was an increase in SvO2 after the final BPA of >125.4% over the baseline value (specificity 100%, sensitivity 24.1%). In conclusion, BPA improved symptoms, right heart function, hemodynamics, and renal function up to the chronic phase. Increasing SvO2 by >125.4% above baseline in the acute phase is important for improving renal function at 1 year after BPA in CTEPH patients.
View details for DOI 10.1007/s00380-018-1284-4
View details for PubMedID 30386916
Pulmonary arterial hypertension (PAH) pathogenesis shares similarities with carcinogenesis. One CD44 variant (CD44v) isoform, CD44v8-10, binds to and stabilizes the cystine transporter subunit (xCT), producing reduced glutathione (GSH) and thereby enhancing the antioxidant defense of cancer stem cells. Pharmacological inhibition of xCT by sulfasalazine suppresses tumor growth, survival, and resistance to chemotherapy. We investigated whether the CD44v-xCT axis contributes to PAH pathogenesis. CD44v was predominantly expressed on endothelial-to-mesenchymal transition (EndMT)-like cells in the neointimal layer of PAH affected pulmonary arterioles. In vitro, CD44 standard form and CD44v were induced as a result of EndMT. Among human pulmonary artery endothelial cells that have undergone EndMT, CD44v+ cells showed high levels of xCT expression on their cell surface and high concentrations of GSH for survival. This made CD44v+ cells the most vulnerable target for sulfasalazine. CD44v+xCThi cells showed the highest expression levels of pro-inflammatory cytokines, antioxidant enzymes, antiapoptotic molecules, and cyclin-dependent kinase inhibitors. In the Sugen5416/hypoxia mouse model, CD44v+ cells were present in the thickened pulmonary vascular wall. The administration of sulfasalazine either started at the same time as sugen5416 administration (a prevention model) or after the development of PH (a reversal model) attenuated the muscularization of the pulmonary vessels, decreased the expression of markers of inflammation, and reduced the right ventricular systolic pressure, while reducing CD44v+ cells. In conclusion, CD44v+xCThi cells appear during EndMT and in PH tissues. Sulfasalazine is expected to be as a novel therapeutic agent for PAH, most likely targeting EndMT-derived CD44v+xCThi cells.
View details for DOI 10.1165/rcmb.2018-0231OC
View details for PubMedID 30897333
There is no consensus on the length of hospital stay (LOHS) and post-interventional management after balloon pulmonary angioplasty (BPA) in patients with chronic thromboembolic pulmonary hypertension (CTEPH). We examined temporal trends with respect to LOHS and requirement for intensive care for BPA and their relationship with the incidence of BPA-related complications.From November 2012 to September 2017, a total of 123 consecutive patients with CTEPH who underwent BPA were enrolled (age: 66.0 [54.0 to 74.0], World Health Organization [WHO] functional class II/III/IV; 27/88/8). Patients were divided for analysis into 3 groups according to the date of their first BPA: early-, middle-, and late-phase groups.Mean pulmonary arterial pressure decreased from 36.0 (29.0 to 45.0) to 20.0 (16.0 to 22.0) mm Hg after BPA (P < 0.001). The LOHS was 41.0 (31.0 to 54.0) days in total including all sessions and 6.6 (6.0 to 7.9) days/session. Despite no significant differences in age, baseline hemodynamics, and laboratory data among the 3 groups, there was a significant reduction in LOHS (7.9 [7.0 to 9.5], 6.5 [6.1 to 7.3], 6.0 [5.3 to 6.5] days/session, P < 0.001) and use of intensive/high care unit (100%, 93%, 46%, P < 0.001). The reduction in LOHS and intensive/high care unit use did not affect the occurrence of BPA-related complications.Increasing experience with BPA was associated with a reduction in LOHS and the use of intensive/high care unit, but no change was noted in the rate of BPA-related complications. These findings suggest that the reduction in both LOHS and use of the intensive care unit for BPA is feasible and does not jeopardize the safety of the procedure.
View details for DOI 10.1016/j.cjca.2018.12.001
View details for PubMedID 30760426
Pulmonary arterial hypertension (PAH) is a rare but serious disease with a grave prognosis. Bone morphogenetic protein type 2 receptor (BMPR2) gene is a strong pathogenic factor for PAH. As a collaborative team from Kyorin University and Keio University in Japan, we have analyzed the BMPR2 gene in 356 probands and more than 50 family members, including secondary patients. Importantly, the study population is a racially, ethnically, and socially homogeneous population. In PAH patients, there is a high incidence of unique mutations in BMPR2, and several mutations are frequently observed in the Japanese population, suggesting that these common and recurring mutations may be highly pathogenic or have high penetrance, explaining why they are found frequently throughout the world. We have also mapped each breakpoint of exonic deletions/duplications and found that most break and rejoining points are in the Alu elements. Reviewing the distribution of the reported mutations on each exon of BMPR2 revealed that the number and frequency of mutations are imbalanced among exons. The penetrance of BMPR2 gene mutations was 3-fold higher in females than males. Full elucidation of BMPR2-mediated pathogenic mechanisms in PAH requires persistent efforts to achieve precision or individualized medicine as a therapeutic strategy for PAH.
View details for DOI 10.1111/cge.13154
View details for PubMedID 29023671
Chronic thromboembolic pulmonary hypertension (CTEPH) has a poor prognosis because of the associated progressive right heart failure. Accurate evaluation of right ventricular (RV) function would thus be useful to predict prognosis. However, the significance of RV diastolic function remains unclear. We aimed to identify which echocardiographic measures are most accurate, and potentially useful, in assessing RV diastolic function in patients with CTEPH, and to study the effects of balloon pulmonary angioplasty (BPA) on them. We enrolled 53 CTEPH patients who underwent BPA. Echocardiographic parameters, including two-dimensional speckle-tracking echocardiography, were compared to the hemodynamic parameters measured by right heart catheterization before and after BPA. RV strain rate during early diastole (SR_E), tricuspid e' and right atrial area (RAA) were ameliorated after BPA, concomitant with a decrease in the time constant of the RV pressure curve during diastole (tau), indicating the improvement of RV diastolic function. Among them, SR_E had the strongest correlation with tau (r = - 0.39, p < 0.001). Furthermore, the receiver operating characteristic analyses revealed that E/SR_E (AUC 0.704) and inferior vena cava diameter (AUC 0.726) had a stronger association with higher mean right atrial pressure than RAA (AUC 0.632). In contrast, RAA had a stronger correlation with 6 min-walk distances than SR_E (r = - 0.39, p < 0.001 vs. r = 0.30, p = 0.005). Taken together, echocardiographic assessment of RV diastolic function might be associated with hemodynamics as well as exercise tolerance in patients with CTEPH, indicating its benefits in evaluating the therapeutic effects of BPA.
View details for DOI 10.1007/s10554-017-1296-7
View details for PubMedID 29290029
Increase in saturated fatty acid (SFA) content in membrane phospholipids dramatically affects membrane properties and cellular functioning. We sought to determine whether exogenous SFA from the diet directly affects the degree of membrane phospholipid unsaturation in adult hearts and if these changes correlate with contractile dysfunction. Although both SFA-rich high fat diets (HFDs) and monounsaturated FA (MUFA)-rich HFDs cause the same degree of activation of myocardial FA uptake, triglyceride turnover, and mitochondrial FA oxidation and accumulation of toxic lipid intermediates, the former induced more severe diastolic dysfunction than the latter, which was accompanied with a decrease in membrane phospholipid unsaturation, induction of unfolded protein response (UPR), and a decrease in the expression of Sirt1 and stearoyl-CoA desaturase-1 (SCD1), catalyzing the conversion of SFA to MUFA. When the SFA supply in the heart overwhelms the cellular capacity to use it for energy, excess exogenous SFA channels to membrane phospholipids, leading to UPR induction, and development of diastolic dysfunction.
View details for DOI 10.1371/journal.pone.0208396
View details for PubMedID 30533011
View details for PubMedCentralID PMC6289418
Both osteopontin (OPN) and galectin-3 have been implicated in phagocytic clearance of dead cells and reparative fibrosis during wound healing. CD206+ macrophages are involved in tissue repair through phagocytosis and fibrosis after myocardial infarction (MI). However, the relationship among OPN, galectin-3, and macrophage polarization in the context of MI remains unclear.The time course of Spp1 (encoding OPN) expression in the heart after MI showed a strong activation of Spp1 on day 3 after MI. To identify where in the body and in which cells the transcriptional activity of Spp1 increased after MI, we analyzed EGFP (enhanced green fluorescent protein)- Spp1 knockin reporter mice on day 3 after MI.The transcriptional activity of Spp1 increased only in CD206+ macrophages in the infarct myocardium, and most of CD206+ macrophages have strong transcriptional activation of Spp1 after MI. The temporal expression pattern of Lgal3 (encoding galectin-3) in cardiac macrophages after MI was similar to that of Spp1, and OPN is almost exclusively produced by galectin-3hiCD206+ macrophages. Although both interleukin (IL)-4 and IL-10 were reported to promote CD206+ macrophage-mediated cardiac repair after MI, IL-10- but not IL-4-stimulated CD11b+Ly6G- cells could differentiate into OPN-producing galectin-3hiCD206+ macrophages and showed enhanced phagocytic ability. Inhibition of STAT3 tyrosine phosphorylation suppressed IL-10-induced expression of intracellular galectin-3 and transcriptional activation of Spp1. Knockdown of galectin-3 suppressed their ability to differentiate into OPN-producing cells, but not STAT3 activation. The tyrosine phosphorylation of STAT3 and the appearance rate of galectin-3hiCD206+ cells on cardiac CD11b+Ly6G- cells in Spp1 knockout mice were the same as those in wild-type mice. Spp1 knockout mice showed vulnerability to developing post-MI left ventricular chamber dilatation and the terminal deoxynucleo-tidyltransferase 2'-Deoxyuridine-5'-triphosphate nick-end labeling (TUNEL)-positive cells in the infarcted myocardium after MI remained higher in number in Spp1 knockout mice than in wild-type mice.OPN is almost exclusively produced by galectin-3hiCD206+ macrophages, which specifically appear in the infarct myocardium after MI. The IL-10-STAT3-galectin-3 axis is essential for OPN-producing reparative macrophage polarization after myocardial infarction, and these macrophages contribute to tissue repair by promoting fibrosis and clearance of apoptotic cells. These results suggest that galectin-3 may contribute to reparative fibrosis in the infarct myocardium by controlling OPN levels.
View details for DOI 10.1161/CIRCULATIONAHA.118.035047
View details for PubMedID 29967195
Angiotensin II (Ang II) activates components of the inflammatory cascade, which promotes hypertension and development of abdominal aortic aneurysm (AAA). This study aimed to elucidate the effects of an IL-1 receptor antagonist (IL-1Ra) and an anti-IL-1β antibody (01BSUR) on Ang II-induced AAA.Male wild-type (WT) and IL-1Ra-deficient (IL-1Ra-/-) mice were infused with Ang II (1000 ng/kg/min) using subcutaneous osmotic pumps for 28 days. Fourteen days post-infusion, both systolic blood pressure (SBP) (Ang II-treated IL-1Ra-/-:149 ± 2 vs. Ang II-treated WT:126 ± 3 mm Hg, p < 0.001) and abdominal aortic width (0.94 ± 0.09 vs. 0.49 ± 0.03 mm, p < 0.001) were significantly higher in IL-1Ra-/- mice than in WT mice. Because 28-day infusion with Ang II in IL-1Ra-/- mice significantly increased the occurrence of fatal aortic rupture (89% vs. 6%, p < 0.0001), both types of mice were infused with Ang II for only 14 days, and histological analyses were performed at 28 days. Interestingly, AAA increased more significantly in IL-1Ra-/- mice than in WT mice (p < 0.001), although SBP did not differ at 28 days in IL-1Ra-/- and WT mice (117 ± 4 vs. 115 ± 3 mm Hg, p = 0.71 (after cessation of Ang II infusion)). Histological analyses showed numerous inflammatory cells around the abdominal aorta in IL-1Ra-/- mice, but not in WT mice. Finally, compared with IgG2a treatment, treatment with 01BSUR decreased Ang II-induced AAA in IL-1Ra-/- mice.The present study demonstrates that inhibition of IL-1β significantly suppresses AAA formation after Ang II infusion, suggesting that suppression of IL-1β may provide an additional strategy to protect against AAA in hypertensive patients.
View details for DOI 10.1016/j.ijcard.2018.05.072
View details for PubMedID 29884291
The correlation between serum adiponectin concentration and hemodynamics or certain metabolic markers in patients with chronic thromboembolic pulmonary hypertension (CTEPH) is unknown.Methods and Results:We enrolled 30 CTEPH patients who underwent interventional therapy of balloon pulmonary angioplasty or pulmonary endarterectomy. Serum adiponectin concentrations positively correlated with B-type natriuretic peptide (BNP) concentrations, pulmonary vascular resistance, and mean pulmonary arterial pressure. After the therapeutic interventions, serum adiponectin concentrations improved and changes in serum adiponectin concentrations significantly correlated with changes in BNP concentrations.Adiponectin can be a useful marker for the severity of CTEPH.
View details for DOI 10.1253/circj.CJ-17-1434
View details for PubMedID 29563354
It has never been possible to immediately evaluate heart rate variability (HRV) during exercise. We aimed to visualize the real-time changes in the power spectrum of HRV during exercise and to investigate its relationship to the ventilatory threshold (VT).Thirty healthy subjects (29.1±5.7 years of age) and 35 consecutive patients (59.0±13.2 years of age) with myocardial infarctions underwent cardiopulmonary exercise tests with an RAMP protocol ergometer. The HRV was continuously assessed with power spectral analyses using the maximum entropy method and projected on a screen without delay. During exercise, a significant decrease in the high frequency (HF) was followed by a drastic shift in the power spectrum of the HRV with a periodic augmentation in the low frequency/HF (L/H) and steady low HF. When the HRV threshold (HRVT) was defined as conversion from a predominant high frequency (HF) to a predominant low frequency/HF (L/H), the VO2 at the HRVT (HRVT-VO2) was substantially correlated with the VO2 at the lactate threshold and VT) in the healthy subjects (r=0.853 and 0.921, respectively). The mean difference between each threshold (0.65 mL/kg per minute for lactate threshold and HRVT, 0.53 mL/kg per minute for VT and HRVT) was nonsignificant (P>0.05). Furthermore, the HRVT-VO2 was also correlated with the VT-VO2 in these myocardial infarction patients (r=0.867), and the mean difference was -0.72 mL/kg per minute and was nonsignificant (P>0.05).A HRV analysis with our method enabled real-time visualization of the changes in the power spectrum during exercise. This can provide additional information for detecting the VT.
View details for DOI 10.1161/JAHA.117.006612
View details for PubMedID 29307865
View details for PubMedCentralID PMC5778955
Obesity promotes excessive inflammation, which is associated with senescence-like changes in visceral adipose tissue (VAT) and the development of type 2 diabetes (T2DM) and cardiovascular diseases. We have reported that a unique population of CD44hi CD62Llo CD4+ T cells that constitutively express PD-1 and CD153 exhibit cellular senescence and cause VAT inflammation by producing large amounts of osteopontin. Weight loss improves glycemic control and reduces cardiovascular disease risk factors, but its long-term effects on cardiovascular events and longevity in obese individuals with T2DM are somewhat disappointing and not well understood. High-fat diet (HFD)-fed obese mice were subjected to weight reduction through a switch to a control diet. They lost body weight and visceral fat mass, reaching the same levels as lean mice fed a control diet. However, the VAT of weight reduction mice exhibited denser infiltration of macrophages, which formed more crown-like structures compared to the VAT of obese mice kept on the HFD. Mechanistically, CD153+ PD-1+ CD4+ T cells are long-lived and not easily eliminated, even after weight reduction. Their continued presence maintains a self-sustaining chronic inflammatory loop via production of large amounts of osteopontin. Thus, we concluded that T-cell senescence is essentially a negative legacy effect of obesity.
View details for DOI 10.1371/journal.pone.0186303
View details for PubMedID 29073165
View details for PubMedCentralID PMC5657997
Pulmonary hypertension (PH), caused by elevated pulmonary vascular resistance, leads to right heart failure and ultimately death. Vitamin D deficiency can predispose individuals to hypertension and left ventricular dysfunction; however, it remains unknown how serum vitamin D level is related to PH and right ventricular (RV) dysfunction.Serum 25-hydroxyvitamin D [25(OH)D] levels were assessed in PH patients for an association with disease severity. To examine whether vitamin D supplementation could prevent the development of pulmonary vascular remodeling and RV dysfunction in PH, a rat model of PH was fed either normal chow or a high vitamin D diet.The majority (95.1%) of PH patients had 25(OH)D levels in the insufficiency range, which is associated with increased mean pulmonary artery pressure, increased pulmonary vascular resistance, and decreased cardiac output in PH patients. Vitamin D supplementation significantly increased serum 25(OH)D levels and improved survival in PH rats. Interestingly, while the supplemented rats retained the typical increases in medial thickness of the muscular pulmonary arteries and RV systolic pressure, RV cardiomyocyte hypertrophy and B-type natriuretic peptide expression was significantly attenuated.Vitamin D deficiency is frequently seen in patients diagnosed with PH and low serum levels of 25(OH)D are associated with severity of PH and RV dysfunction. Vitamin D supplementation in PH rats improved survival via ameliorating pathological RV hypertrophy. These findings suggest an insufficient intake of vitamin D might potentially accelerate RV dysfunction, leading to a crucial clinical impact of vitamin D supplementation in PH.
View details for DOI 10.1371/journal.pone.0180615
View details for PubMedID 28686688
View details for PubMedCentralID PMC5501558
The acute favourable effect of balloon pulmonary angioplasty (BPA) has been proven in patients with chronic thromboembolic pulmonary hypertension (CTEPH). However, data on its effect 6 months after therapy (from now on referred to as mid-term) and influence on the right ventricle and myocardial damage are sparse. To evaluate factors that influence improvement in cardiac output (CO) and subclinical myocardial damage, we examined hemodynamics and serum high-sensitivity troponin T (hs-TnT) levels before, 1 week after, and 6 months after BPA.In a retrospective study, we reviewed 67 consecutive patients from November 2012 to January 2016 with CTEPH who had undergone BPA at Keio University Hospital.Six months after BPA, the mean right atrium pressure, mean pulmonary artery pressure (PAP), pulmonary vascular resistance (PVR), B-type natriuretic peptide (BNP), and hs-TnT levels decreased; CO and 6-minute walking distance increased. Changes in CO and hs-TnT levels varied compared with other hemodynamic parameters and BNP levels. The CO-increase group (n = 42) had higher mean PAP and PVR, and lower CO at baseline than the CO-decrease/stable group (n = 25). The hs-TnT-decrease group (n = 36) had higher mean right atrium pressure, PAP, PVR, and BNP levels, and lower CO at baseline than the hs-TnT-increase/stable group (n = 31).Six months after BPA, hemodynamics and exercise capacity improved and hs-TnT levels decreased. Improvements in CO and hs-TnT levels were more prominent in CTEPH patients with impaired baseline hemodynamics, suggesting that BPA has a favourable mid-term effect on hemodynamics and subclinical myocardial damage in patients with CTEPH, especially in those with impaired hemodynamics.
View details for DOI 10.1016/j.cjca.2016.12.003
View details for PubMedID 28256427
Chronic inflammation in visceral adipose tissue (VAT) precipitates the development of cardiometabolic disorders. Although changes in T cell function associated with visceral obesity are thought to affect chronic VAT inflammation, the specific features of these changes remain elusive. Here, we have determined that a high-fat diet (HFD) caused a preferential increase and accumulation of CD44hiCD62LloCD4+ T cells that constitutively express PD-1 and CD153 in a B cell-dependent manner in VAT. These cells possessed characteristics of cellular senescence and showed a strong activation of Spp1 (encoding osteopontin [OPN]) in VAT. Upon T cell receptor stimulation, these T cells also produced large amounts of OPN in a PD-1-resistant manner in vitro. The features of CD153+PD-1+CD44hiCD4+ T cells were highly reminiscent of senescence-associated CD4+ T cells that normally increase with age. Adoptive transfer of CD153+PD-1+CD44hiCD4+ T cells from HFD-fed WT, but not Spp1-deficient, mice into the VAT of lean mice fed a normal diet recapitulated the essential features of VAT inflammation and insulin resistance. Our results demonstrate that a distinct CD153+PD-1+CD44hiCD4+ T cell population that accumulates in the VAT of HFD-fed obese mice causes VAT inflammation by producing large amounts of OPN. This finding suggests a link between visceral adiposity and immune aging.
View details for DOI 10.1172/JCI88606
View details for PubMedID 27820698
View details for PubMedCentralID PMC5127667
Plasma amino acid concentrations (aminogram) show distinct patterns under various pathologic conditions. However, the plasma aminogram pattern in patients with pulmonary hypertension (PH) has not been elucidated. We sought to examine whether an aminogram could be predictive of clinical severity in patients with PH. We attained fasting plasma aminograms for 140 patients with PH and then compared the patient plasma amino acid levels with those of age- and gender-matched healthy control subjects. Aminograms revealed that the plasma concentrations of many amino acids were significantly different between patients with PH and healthy control subjects. We focused on the Fischer ratio (branched-chain amino acids/aromatic amino acids) as an integrated parameter. In all enrolled patients, Fischer ratio was negatively correlated with New York Heart Association functional class (ρ = -0.37, p <0.001), plasma B-type natriuretic peptide (ρ = -0.35, p <0.001), and pulmonary vascular resistance (ρ = -0.27, p = 0.002) and positively correlated with venous oxygen saturation (ρ = 0.27, p = 0.002) and 6-minute walk distance (ρ = 0.23, p = 0.016). Time course changes in Fischer ratio and in cardiac output were significantly correlated (ρ = 0.39, p = 0.024). The aminogram is changed in patients with PH, and in these patients, Fischer ratio decreases in proportion to the clinical severity of PH.
View details for DOI 10.1016/j.amjcard.2014.12.048
View details for PubMedID 25640523
Interleukin-1 receptor antagonist (IL-1Ra) negatively regulates IL-1 signaling by blocking the functional receptor. We previously demonstrated that IL-1Ra-deficient (IL-1Ra-/-) mice exhibit marked neointimal formation after injury. IL-1Ra is expressed on bone marrow (BM)-derived cells as well as non-BM intrinsic arterial cells. However, the importance of various cell types as sources of IL-1Ra remains unknown. The aim of this study was to test the hypothesis that IL-1Ra originating from BM-derived cells and non-BM intrinsic cells helps to suppress both inflammation and neointimal formation after vascular injury using a model of BM cell transplantation (BMT).In order to determine the contribution of IL-1Ra-deficient (Ra-/-) and wild-type (WT) BM cells to neointimal formation, we developed four types of BM chimeric mice (BMT(WT→WT) (n=12), BMT(Ra-/-→WT) (n=12), BMT(WT→Ra-/-) (n=12) and BMT(Ra-/-→Ra-/-) (n=12)). At four weeks after BMT, we induced vascular injury by placing a non-occlusive cuff around the femoral artery. Histological analyses were subsequently performed two weeks after injury.Neointimal formation was decreased in the BMT(WT→Ra-/-) mice compared with that observed in the BMT(Ra-/-→Ra-/-) mice (p＜0.001), but significantly more so in the BMT(Ra-/-→WT) (p＜0.01) and BMT(WT→WT) (p＜0.01) mice. In contrast, the neointimal formation in the BMT(Ra-/-→WT) mice was significantly increased compared with that noted in the BMT(WT→WT) mice (p＜0.05). In addition, immunostaining revealed that Mac3-positive areas were significantly increased in the BMT(Ra-/-→Ra-/-) mice compared with those seen in the other three groups (p＜0.001), with a significantly decreased percentage of alpha-SMA-positive areas in the neointima in the BMT(Ra-/-→Ra-/-) mice compared with that found in the remaining groups (p＜0.001). Furthermore, IL-1Ra staining demonstrated the IL-1Ra expression in several inflammatory cells in the adventitia in the BMT(WT→WT) and BMT(WT→Ra-/-) mice, compared to the neointima in the BMT(WT→WT) and BMT(Ra-/-→WT) mice.The IL-1Ra present in BM-derived cells and non-BM cells helps to suppress arterial inflammation, resulting in decreased neointimal formation after injury. These findings shed new light on the mechanisms underlying the development of atherosclerosis and restenosis after angioplasty.
View details for PubMedID 25223697
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