Blockade of CD80/CD86-CD28 co-stimulation augments the inhibitory function of peptide antigen-specific regulatory T cells.

Mixed lymphocyte culture under the blockade of CD80/CD86-CD28 co-stimulation induces anergic (completely hyporesponsive) T cells with immune suppressive function (inducible suppressing T cells: iTS cells). Previously, iTS cell therapy has demonstrated outstanding benefits in clinical trials for organ transplantation. Here, we examined whether peptide antigen-specific iTS cells are inducible. DO 11.10 iTS cells were obtained from splenocytes of BALB/c DO 11.10 mice by stimulation with OVA peptide and antagonistic anti-CD80/CD86 mAbs. When DO 11.10 iTS or Foxp3- DO 11.10 iTS cells were stimulated with OVA, these cells produced IL-13, but not IL-4. DO 11.10 iTS cells decreased IL-4 and increased IL-13 production from OVA-stimulated naïve DO 11.10 splenocytes. When Foxp3+ DO 11.10 iTS cells were prepared, these cells significantly inhibited the production of IL-4 and IL-13 compared with freshly isolated Foxp3+ DO 11.10 T cells. Moreover, an increase in the population expressing OX40, ICOS, and 4-1BB suggested activation of Foxp3+ DO 11.10 iTS cells. Thus, blockade of CD80/CD86-CD28 co-stimulation during peptide antigen stimulation augments the inhibitory function of Foxp3+ regulatory T cells, and does not induce anergic Foxp3- conventional T cells. Peptide-specific Foxp3+ regulatory iTS cells could be useful for the treatment of allergic and autoimmune diseases without adverse effects.

CD8+ T cell-mediated rejection of allogenic human-induced pluripotent stem cell-derived cardiomyocyte sheets in human PBMC-transferred NOG MHC double knockout mice.

BACKGROUND: Transplantation of human-induced pluripotent stem cell-derived cardiomyocytes (hiPS-CMs) has emerged as a promising therapy to treat end-stage heart failure. However, the immunogenicity of hiPS-CMs in transplanted patients has not been fully elucidated. Thus, in vivo models are required to estimate immune responses against hiPS-CMs in transplant recipients. METHODS: We transferred human peripheral blood mononuclear cells (hPBMCs) into NOD/Shi-scid IL-2rgnull (NOG) MHC class I/II double knockout (NOG-ΔMHC) mice, which were reported to accept hPBMCs without xenogeneic-graft-versus-host disease (xeno-GVHD). Then, hiPS-CM sheets generated from the hiPS cell line 201B7 harboring a luciferase transgene were transplanted into the subcutaneous space of NOG-ΔMHC mice. Graft survival was monitored by bioluminescent images using a Xenogen In Vivo Imaging System. RESULTS: The human immune cells were engrafted for more than 3 months in NOG-ΔMHC mice without lethal xeno-GVHD. The hiPS-CMs expressed a moderate level of human leukocyte antigen (HLA)-class I, but not HLA-class II, molecules even after interferon-gamma (IFN-γ) stimulation. Consistently, the allogenic IFN-γ-treated hiPS-CMs induced weak CD8+ but not CD4+ T cell responses in vitro. hiPS-CM sheets disappeared approximately 17 to 24 days after transplantation in hPBMC-transferred NOG-ΔMHC mice, and CD8+ T cell depletion significantly prolonged graft survival, similar to what was observed following tacrolimus treatment. CONCLUSIONS: hiPS-CMs are less immunogenic in vitro but induce sufficient CD8+ T cell-mediated immune responses for graft rejection in vivo.

Analysis of therapeutic potential of monocytic myeloid-derived suppressor cells in cardiac allotransplantation.

BACKGROUND: Myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Tregs) are attractive immune cells to induce immune tolerance. To explore a strategy for improving the efficacy of MDSC therapies, we examined the impact of adoptive transfer of several types of MDSCs on graft rejection in a murine heart transplantation model. METHODS: We analyzed the effects of induced syngeneic and allogeneic bone marrow-derived MDSCs (BM-MDSCs) on graft survival and suppressive capacity. We also compared the ability of syngeneic monocytic MDSCs (Mo-MDSCs) and polymorphonuclear MDSCs (PMN-MDSCs) to inhibit graft rejection and investigated the suppression mechanisms. RESULTS: Both syngeneic and allogeneic donor- or allogeneic third-party-derived BM-MDSCs prolonged graft survival, although syngeneic BM-MDSCs inhibited anti-donor immune responses most effectively in vitro. Syngeneic Mo-MDSCs, rather than PMN-MDSCs, were responsible for immune suppression through downregulating inducible nitric oxide synthase (iNOS) and expanded naturally occurring thymic originated Treg (nTreg) in vitro. Adoptive transfer of Mo-MDSCs, but not PMN-MDSCs, prolonged graft survival and increased Treg infiltration into the graft heart. CONCLUSION: Recipient-derived Mo-MDSCs are most effective in prolonging graft survival via inhibiting T cell response and nTreg infiltration.

Retrograde percutaneous coronary intervention for acute myocardial infarction following blunt chest trauma.

A 78-year-old man was admitted to the emergency department because of chest pain following blunt chest trauma. Chest X-ray revealed multiple rib fractures. However, electrocardiogram showed ST elevation in inferior leads suggesting acute myocardial infarction (AMI). Emergency coronary angiography revealed normal left coronary artery and occluded proximal right coronary artery. Thus, percutaneous coronary intervention (PCI) was performed immediately. Antegrade PCI was unsuccessful due to a very large false lumen, which was caused by a blunt trauma. However, retrograde guidewire (GW) manipulation was relatively easy to negotiate the occluded lesion. After GW externalization, we deployed two drug eluting stents for this lesion. To our knowledge, this is the first case of retrograde PCI that led to a successful reperfusion therapy for AMI following blunt chest trauma.

Feasibility of a novel tacking method of securing mesh in transabdominal preperitoneal inguinal hernia repair: Secure tacking against recurrence.

INTRODUCTION: Postoperative chronic pain is an important outcome of hernia surgery. In laparoscopic hernia surgery, either fixation outside the trapezoid of disaster or no fixation is recommended to avoid postoperative pain. To avoid recurrence are transabdominal preperitoneal (TAPP) hernia repair, the myopectineal orifice must be covered with mesh during TAPP, but lifting or shrinking of the mesh can lead to recurrence. The aim of this study was to evaluate the feasibility of a novel technique for mesh fixation to prevent the mesh from lifting off. METHODS: After the preperitoneal space was created during TAPP, the anatomy of the lateral cutaneous nerve of the thigh or the femoral branch of the genitofemoral nerve within the trapezoid of disaster was checked. The mesh was tacked at the trapezoid of disaster without nerve injury, and the mesh was fixed with circumferential tacking. We call this procedure secure tacking against recurrence (STAR). We treated 391 adult patients (478 hernias) with TAPP repair; novel tacking was used in some patients (STAR group, 236 hernias). The results of the STAR group were retrospectively compared with those of patients in whom we did not use this novel tacking (conventional group, 242 hernias). RESULTS: There was no postoperative chronic pain in either group. There were no cases of hernia recurrence in the STAR group, but there were four cases of hernia recurrence in the conventional group (0% vs 1.7%, P = 0.047). These four recurrences consisted of indirect hernia and mesh lifting on the lateral side. CONCLUSION: The STAR procedure is feasible and safety as a standard procedure for securing the mesh during TAPP.

Estimation of the Compatibility of Blend Composites of Resins by Measuring the Fluorescent Spectra.

The effects of adding desipramine-containing fluorescence polymer (poly(10,11-dihydro-5-[3-(N-methylamino)propyl]dibenz[b,f]azepine-2,8-diyl-alt-9,9-didodecylfluorene-2,7-diyl, PAzep-Fl) to resins were investigated. When composites were prepared by a reactive blend of poly(lactic acid) (PLA), PAzep-Fl, and diisocyanate, the molecular weight of the obtained composite was larger than that of the composite, which was blended without PAzep-Fl; this suggested that chemical bonding occured between PLA and PAzep-Fl via diisocyanate. The effects of adding PAzep-Fl in two kinds of resins/lysine triisocyanate (LTI) blend were also investigated. The addition of LTI to resins/PAzep-Fl blend composites afforded a shorter wavelength shift of the fluorescence λmax due to the release of the aggregation of PAzep-Fl by LTI. This suggested that the compatibility of two kinds of resins could be estimated by this simple method. The addition of PAzep-Fl to PLA/poly(ε-caprolactone) (PCL)/LTI blends improved the impact strength because of chemical bond formation between PAzep-Fl and the resins (PLA and PCL) via LTI.

[Anesthetic management of laparoscopic cholecystectomy for a patient with Churg-Strauss syndrome: a case report].

Churg-Strauss syndrome (CSS) is an uncommon disease characterized by bronchial asthma, eosinophilia and systemic vasculitis. Many patients with CSS are suffering from cardiovascular disorders, neurological disorders and/or renal disorders which are associated with systemic vasculitis. Cardiac diseases are considered as the main cause of the death in patients with CSS. Steroid administration is the standard pharmacological therapy for CSS. There are very few clinical reports concerning anesthetic management for the patients with CSS. We suppose that precise perioperative managements are required for the patients with CSS, including the appropriate control of bronchial asthma and the careful treatments of disorders in cardiovascular system, neurological system and/or kidney. In addition, we believe that the steroid cover should be considered during the perioperative period of the patients with CSS. Here, we describe an anesthetic management of a 28-year-old man with CSS undergoing laparoscopic cholecystectomy. General anesthesia was induced with midazolam and fentanyl. Rocuronium was administered to facilitate tracheal intubation. After tracheal intubation, anesthesia was maintained with sevoflurane and remifentanil. Prior to the surgery, 100 mg of hydrocortisone was administered for the steroid cover. The surgery was uneventful. The patient emerged from general anesthesia smoothly, and was extubated safely.

Effects of change in the formulation of lanthanum carbonate on laboratory parameters.

Lanthanum carbonate (LC) is available in the two formulations of chewable tablets and granules. In this study, we changed the formulation of LC from chewable tablet to granules, and compared the laboratory parameters for 3 months before and after changing formulation in 58 hemodialysis (HD) patients. We also surveyed patients about their preferences for the two formulations. The mean serum phosphorus (P) levels decreased significantly (P < 0.01) from 6.7 mg/dL to 6.4 mg/dL after the change. The levels for serum albumin and geriatric nutritional risk index increased significantly (P < 0.01). Serum calcium levels also increased significantly (P < 0.01), while serum intact parathyroid hormone levels decreased significantly (P < 0.01). In the survey, approximately half of the patients responded that the granules were easier to take than the chewable tablets. These findings suggest that changing the formulation of LC to granules may reduce serum P levels of the HD patients in clinical practices.

Angiotensin II type 1a receptor signalling directly contributes to the increased arrhythmogenicity in cardiac hypertrophy.

BACKGROUND AND PURPOSE: Angiotensin II has been implicated in the development of various cardiovascular ailments, including cardiac hypertrophy and heart failure. The fact that inhibiting its signalling reduced the incidences of both sudden cardiac death and heart failure in several large-scale clinical trials suggests that angiotensin II is involved in increased cardiac arrhythmogenicity during the development of heart failure. However, because angiotensin II also promotes structural remodelling, including cardiomyocyte hypertrophy and cardiac fibrosis, it has been difficult to assess its direct contribution to cardiac arrhythmogenicity independently of the structural effects. EXPERIMENTAL APPROACH: We induced cardiac hypertrophy in wild-type (WT) and angiotensin II type 1a receptor knockout (AT1aR-KO) mice by transverse aortic constriction (TAC). The susceptibility to ventricular tachycardia (VT) assessed in an in vivo electrophysiological study was compared in the two genotypes. The effect of acute pharmacological blockade of AT1R on the incidences of arrhythmias was also assessed. KEY RESULTS: As described previously, WT and AT1aR-KO mice with TAC developed cardiac hypertrophy to the same degree, but the incidence of VT was much lower in the latter. Moreover, although TAC induced an increase in tyrosine phosphorylation of connexin 43, a critical component of gap junctional channels, and a reduction in ventricular levels of connexin 43 protein in both genotypes, the effect was significantly ameliorated in AT1aR-KO mice. Acute pharmacological blockade of AT1R also reduced the incidence of arrhythmias. CONCLUSIONS AND IMPLICATIONS: Our findings demonstrate that AT1aR-mediated signalling makes a direct contribution to the increase in arrhythmogenicity in hypertrophied hearts independently of structural remodelling.

[A case of acute renal failure following compartment syndrome after the surgery for femoral neck fracture].

Compartment syndrome is known to develop after a prolonged surgery in the lithotomy position. We experienced acute renal failure following compartment syndrome after the surgery in hemilithotomy position. A 62-year-old man underwent a left hip fixation for femoral neck fracture. The surgical leg was placed into traction in a foot piece and the intact leg was placed in the hemilithotomy position. Because of the difficulty in repositioning and the trouble with fluoroscope, the surgery took over 5 hours. He suffered acute pain, swelling and spasm in his intact leg placed into hemilithotomy after the surgery. Creatine kinase, blood urea nitrogen and creatinine markedly increased and myoglobinuria was recognized. We diagnosed an acute renal failure following compartment syndrome and treated him in the ICU on close monitoring. In spite of the treatment with massive transfusion and diuretics, he needed hemodialysis twice and then his renal function improved. Prevention is most essential for compartment syndrome after a prolonged surgery in the lithotomy position. Risk factors should be recognized before surgery and appropriate action should be taken such as using Allen stirrups and avoiding hypotension, hypovolemia and the prolonged lithotomy position with exaggerated elevation of legs.

Determination of the B-type natriuretic peptide level as a criterion for abnormalities in Japanese individuals in routine clinical practice: the J-ABS Multi-Center Study (Japan Abnormal BNP Standard).

OBJECTIVE: The present study was undertaken to establish a useful range for the B-type natriuretic peptide (BNP) level, with the ultimate goal of determining a cut-off BNP level that will make it possible to identify patients with clinically important organic heart disorders among patients encountered in clinical practice. METHODS: A total of 11,967 outpatients were evaluated for this study, and, after applying the exclusion criteria, 361 patients were finally recruited for the analysis. Compared to the factors of gender and body mass index, aging was considered to be an indispensable factor in this analysis. The 'median' plasma BNP level was found to increase slowly with age, but remained lower than 30 pg/mL, even in patients aged 60 years or older. In contrast, the overall '95th percentile' of the plasma BNP level in the patients younger than 60 years was 41 pg/mL, which increased to 139.8 pg/mL in the patients aged 60 years or older. CONCLUSION: These findings suggest that the lower range of the BNP level allowing for identification of patients with clinically important organic heart disorders increases with age; however, it might be appropriate to adopt a level of approximately 40 pg/mL, even in elderly patients, in order to avoid any possible age-related effects of diastolic dysfunction or other factors.

Induction and enhancement of cardiac cell differentiation from mouse and human induced pluripotent stem cells with cyclosporin-A.

Induced pluripotent stem cells (iPSCs) are novel stem cells derived from adult mouse and human tissues by reprogramming. Elucidation of mechanisms and exploration of efficient methods for their differentiation to functional cardiomyocytes are essential for developing cardiac cell models and future regenerative therapies. We previously established a novel mouse embryonic stem cell (ESC) and iPSC differentiation system in which cardiovascular cells can be systematically induced from Flk1(+) common progenitor cells, and identified highly cardiogenic progenitors as Flk1(+)/CXCR4(+)/VE-cadherin(-) (FCV) cells. We have also reported that cyclosporin-A (CSA) drastically increases FCV progenitor and cardiomyocyte induction from mouse ESCs. Here, we combined these technologies and extended them to mouse and human iPSCs. Co-culture of purified mouse iPSC-derived Flk1(+) cells with OP9 stroma cells induced cardiomyocyte differentiation whilst addition of CSA to Flk1(+) cells dramatically increased both cardiomyocyte and FCV progenitor cell differentiation. Spontaneously beating colonies were obtained from human iPSCs by co-culture with END-2 visceral endoderm-like cells. Appearance of beating colonies from human iPSCs was increased approximately 4.3 times by addition of CSA at mesoderm stage. CSA-expanded human iPSC-derived cardiomyocytes showed various cardiac marker expressions, synchronized calcium transients, cardiomyocyte-like action potentials, pharmacological reactions, and ultra-structural features as cardiomyocytes. These results provide a technological basis to obtain functional cardiomyocytes from iPSCs.

p300 plays a critical role in maintaining cardiac mitochondrial function and cell survival in postnatal hearts.

RATIONALE: It is known that the transcriptional coactivator p300 is crucially involved in the differentiation and growth of cardiac myocytes during development. However, the physiological function of p300 in the postnatal hearts remains to be characterized. OBJECTIVE: We have now investigated the physiological function of p300 in adult hearts. METHODS AND RESULTS: We analyzed transgenic mice exhibiting cardiac-specific overexpression of a dominant-negative p300 mutant lacking the C/H3 domain (p300DeltaC/H3 transgenic [TG] mice). p300DeltaC/H3 significantly inhibited p300-induced activation of GATA- and myocyte enhancer factor 2-dependent promoters in cultured ventricular myocytes, and p300DeltaC/H3-TG mice showed cardiac dysfunction that was lethal by 20 weeks of age. The numbers of mitochondria in p300DeltaC/H3-TG myocytes were markedly increased, but the mitochondria were diminished in size. Moreover, cardiac mitochondrial gene expression, mitochondrial membrane potential and ATP contents were all significantly disrupted in p300DeltaC/H3-TG hearts, suggesting that mitochondrial dysfunction contributes to the progression of the observed cardiomyopathy. Transcription of peroxisome proliferator-activated receptor gamma coactivator (PGC)-1alpha, a master regulator of mitochondrial gene expression, and its target genes was significantly downregulated in p300DeltaC/H3-TG mice, and p300DeltaC/H3 directly repressed myocyte enhancer factor 2C-dependent PGC-1alpha promoter activity and disrupted the transcriptional activity of PGC-1alpha in cultured ventricular myocytes. In addition, myocytes showing features of autophagy were observed in p300DeltaC/H3-TG hearts. CONCLUSIONS: Collectively, our findings suggest that p300 is essential for the maintenance of mitochondrial integrity and for myocyte survival in the postnatal left ventricular myocardium.

T-type Ca2+ channel blockade prevents sudden death in mice with heart failure.

BACKGROUND: Pharmacological interventions for prevention of sudden arrhythmic death in patients with chronic heart failure remain limited. Accumulating evidence suggests increased ventricular expression of T-type Ca(2+) channels contributes to the progression of heart failure. The ability of T-type Ca(2+) channel blockade to prevent lethal arrhythmias associated with heart failure has never been tested, however. METHODS AND RESULTS: We compared the effects of efonidipine and mibefradil, dual T- and L-type Ca(2+) channel blockers, with those of nitrendipine, a selective L-type Ca(2+) channel blocker, on survival and arrhythmogenicity in a cardiac-specific, dominant-negative form of neuron-restrictive silencer factor transgenic mice (dnNRSF-Tg), which is a useful mouse model of dilated cardiomyopathy leading to sudden death. Efonidipine, but not nitrendipine, substantially improved survival among dnNRSF-Tg mice. Arrhythmogenicity was dramatically reduced in dnNRSF-Tg mice treated with efonidipine or mibefradil. Efonidipine acted by reversing depolarization of the resting membrane potential otherwise seen in ventricular myocytes from dnNRSF-Tg mice and by correcting cardiac autonomic nervous system imbalance. Moreover, the R(-)-isomer of efonidipine, a recently identified, highly selective T-type Ca(2+) channel blocker, similarly improved survival among dnNRSF-Tg mice. Efonidipine also reduced the incidence of sudden death and arrhythmogenicity in mice with acute myocardial infarction. CONCLUSIONS: T-type Ca(2+) channel blockade reduced arrhythmias in a mouse model of dilated cardiomyopathy by repolarizing the resting membrane potential and improving cardiac autonomic nervous system imbalance. T-type Ca(2+) channel blockade also prevented sudden death in mice with myocardial infarction. Our findings suggest T-type Ca(2+) channel blockade is a potentially useful approach to preventing sudden death in patients with heart failure.

Impact of thymidine phosphorylase-expressing macrophages for surgical margin in partial nephrectomy.

OBJECTIVES: We investigated the relationship between the surgical margin in partial nephrectomy (PN) and thymidine phosphorylase (TP)-expressing macrophages in peritumoral tissue of renal cell carcinoma (RCC). METHODS: In 46 patients who underwent radical nephrectomy, we measured TP protein levels in tumor tissue, peritumoral tissue and normal tissue, and conducted immunohistochemical staining for TP and macrophages. In addition, we prospectively conducted PN with a 5-mm margin in 11 patients with pT1a RCC. RESULTS: The TP protein level and TP-positive macrophages were correlated with T classification, histological grade, mode of infiltration and venous invasion. However, for pT1 RCC, TP-positive macrophages in pT1a were significantly lower than in pT1b (p = 0.0140), while there was no significant difference in TP protein levels between pT1a and pT1b. No surgical margin was positive in 11 patients who underwent PN with a 5-mm margin, and no patient had local recurrence or distant metastasis during follow-up. CONCLUSIONS: The TP protein level and TP-positive macrophages in the peritumor area are thought to be associated with tumor progression in RCC, while a similar relationship was not found in pT1a RCC. These data suggest that a 5-mm margin might be safe to reduce the risk of local recurrence when PN is performed for treatment of solitary pT1a RCC.

Significance of 5-fluorouracil-related enzyme activities in predicting sensitivity to 5-fluorouracil in bladder carcinoma.

BACKGROUND: The association between 5-fluorouracil (5-FU)-related enzyme activity and the sensitivity of bladder urothelial carcinoma (BUC) to 5-FU were investigated, and methods to improve 5-FU sensitivity were analyzed. MATERIALS AND METHODS: Tumor specimens were obtained from 127 patients. Orotate phosphoribosyl transferase (OPRT) activity was analyzed by the paper disc method and thymidine phosphorylase and dihydropyrimidine dehydrogenase (DPD) activities were measured by ELISA. 5-FU sensitivity was assessed in 99 cases by an in vitro chemosensitivity test. RESULTS: A significant positive correlation between OPRT activity level and the sensitivity of BUC to 5-FU was identified. Moreover, the combination of 5-FU and 5-chloro-2,4-dihydroxypyrimidine significantly enhanced 5-FU sensitivity in BUC, particularly in cases showing higher DPD activity. CONCLUSION: OPRT was the most important enzyme in predicting sensitivity to 5-FU in BUC. These results may have implications for tailor-made medication using 5-FU-related compounds as postoperative adjuvant chemotherapy in BUC patients.

Endogenous cardiac natriuretic peptides protect the heart in a mouse model of dilated cardiomyopathy and sudden death.

Ventricular myocytes are known to show increased expression of the cardiac hormones atrial and brain natriuretic peptide (ANP and BNP, respectively) in response to pathological stress on the heart, but their function during the progression of nonischemic dilated cardiomyopathy remains unclear. In this study, we crossed a mouse model of dilated cardiomyopathy and sudden death, which we generated by cardioselectively overexpressing a dominant-negative form of the transcriptional repressor neuron-restrictive silencer factor (dnNRSF Tg mice), with mice lacking guanylyl cyclase-A (GC-A), a common receptor for ANP and BNP, to assess the effects of endogenously expressed natriuretic peptides during progression of the cardiomyopathy seen in dnNRSF Tg mice. We found that dnNRSF Tg;GC-A(-/-) mice were born normally, but then most died within 4 wk. The survival rates among dnNRSF Tg;GC-A(+/-) and dnNRSF Tg mice were comparable, but dnNRSF Tg;GC-A(+/-) mice showed greater systolic dysfunction and a more severe cardiomyopathic phenotype than dnNRSF Tg mice. Collectively, our findings suggest that endogenous ANP/BNP protects the heart against the death and progression of pathological remodeling in a mouse model of dilated cardiomyopathy and sudden death.

Guanylyl cyclase-A inhibits angiotensin II type 2 receptor-mediated pro-hypertrophic signaling in the heart.

Angiotensin II plays a key role in the development of cardiac hypertrophy. The contribution of the angiotensin II type 1 receptor (AT1) in angiotensin II-induced cardiac hypertrophy is well established, but the role of AT2 signaling remains controversial. Previously, we have shown that natriuretic peptide receptor/guanylyl cyclase-A (GCA) signaling protects the heart from hypertrophy at least in part by inhibiting AT1-mediated pro-hypertrophic signaling. Here, we investigated the role of AT2 in cardiac hypertrophy observed in mice lacking GCA. Real-time RT-PCR and immunoblotting approaches indicated that the cardiac AT2 gene was overexpressed in GCA-deficient mice. Mice lacking AT2 alone did not exhibit an abnormal cardiac phenotype. In contrast, GCA-deficiency-induced increases in heart to body weight ratio, cardiomyocyte cross-sectional area, and collagen accumulation as evidenced by van Gieson staining were attenuated when AT2 was absent. Furthermore, the up-regulated cardiac expression of hypertrophy-related genes in GCA-null animals was also suppressed. Pharmacological blockade of AT2 with PD123319 similarly attenuated cardiac hypertrophy in GCA-deficient mice. In addition, whereas the AT1 antagonist olmesartan attenuated cardiac hypertrophy in GCA-deficient mice, this treatment was without effect on cardiac hypertrophy in GCA/AT2-double null mice, notwithstanding its potent antihypertensive effect in these animals. These results suggest that the interplay of AT2 and AT1 may be important in the development of cardiac hypertrophy. Collectively, our findings support the assertion that GCA inhibits AT2-mediated pro-hypertrophic signaling in heart and offer new insights into endogenous cardioprotective mechanisms during disease pathogenesis.

Effects of a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, fluvastatin, on coronary spasm after withdrawal of calcium-channel blockers.

OBJECTIVES: The purpose of this study was to determine whether a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor (statin) suppresses coronary spasm. BACKGROUND: Coronary spasm is associated with endothelial dysfunction. Statins have been shown to improve endothelial function. METHODS: This was a prospective, randomized, open-label, end point study. Sixty-four patients who had no significant organic coronary stenosis and in whom coronary spasm was induced by intracoronary injection of acetylcholine (ACh) were randomly assigned to fluvastatin 30 mg/day plus the conventional calcium-channel blocker (CCB) therapy (31 patients, statin group) or the conventional CCB therapy (33 patients, nonstatin group). After 6 months of treatment, the intracoronary injection of ACh was repeated and the coronary spasm was assessed. RESULTS: Coronary spasm was suppressed in 16 of the 31 patients (51.5%, p < 0.0001) of the statin group and in 7 of the 33 patients (21.2%, p = 0.0110) of the nonstatin group after 6 months of treatment. Thus, the number of patients with ACh-induced coronary spasm was significantly reduced in the statin group as compared with the nonstatin group (51.6% vs. 21.2%, p = 0.0231) after 6 months of treatment. CONCLUSIONS: The addition of fluvastatin 30 mg/day to the conventional CCB therapy for 6 months significantly reduced the number of patients with ACh-induced coronary spasm as compared with the conventional CCB therapy. Thus, a statin (fluvastatin) may possibly be a novel therapeutic drug for coronary spasm.