Kan Zen

Pressure-Mediated Hypertrophy and Mechanical Stretch Induces IL-1 Release and Subsequent IGF-1 Generation to Maintain Compensative Hypertrophy by Affecting Akt and JNK Pathways

Rationale: It has been reported that interleukin (IL)-1 is associated with pathological cardiac remodeling and LV dilatation, whereas IL-1&bgr; has also been shown to induce cardiomyocyte hypertrophy. Thus, the role of IL-1 in the heart remains to be determined. Objective: We studied the role of hypertrophy signal-mediated IL-1&bgr;/insulin-like growth factor (IGF)-1 production in regulating the progression from compensative pressure-mediated hypertrophy to heart failure. Methods and Results: Pressure overload was performed by aortic banding in IL-1&bgr;–deficient mice. Primarily cultured cardiac fibroblasts (CFs) and cardiac myocytes (CMs) were exposed to cyclic stretch. Heart weight, myocyte size, and left ventricular ejection fraction were significantly lower in IL-1&bgr;–deficient mice (20%, 23% and 27%, respectively) than in the wild type 30 days after aortic banding, whereas interstitial fibrosis was markedly augmented. DNA microarray analysis revealed that IGF-1 mRNA level was markedly (≈50%) decreased in the IL-1&bgr;–deficient hypertrophied heart. Stretch of CFs, rather than CMs, abundantly induced the generation of IL-1&bgr; and IGF-1, whereas such IGF-1 induction was markedly decreased in IL-1&bgr;–deficient CFs. IL-1&bgr; released by stretch is at a low level unable to induce IL-6 but sufficient to stimulate IGF-1 production. Promoter analysis showed that stretch-mediated IL-1&bgr; activates JAK/STAT to transcriptionally regulate the IGF-1 gene. IL-1&bgr; deficiency markedly increased c-Jun N-terminal kinase (JNK) and caspase-3 activities and enhanced myocyte apoptosis and fibrosis, whereas replacement of IGF-1 or JNK inhibitor restored them. Conclusions: We demonstrate for the first time that pressure-mediated hypertrophy and mechanical stretch generates a subinflammatory low level of IL-1&bgr;, which constitutively causes IGF-1 production to maintain adaptable compensation hypertrophy and inhibit interstitial fibrosis.

Granulocyte Colony-Stimulating Factor–Mobilized Circulating c-Kit+/Flk-1+ Progenitor Cells Regenerate Endothelium and Inhibit Neointimal Hyperplasia After Vascular Injury

Background—Granulocyte colony-stimulating factor (G-CSF) treatment was shown to inhibit neointimal formation of balloon-injured vessels, whereas neither the identification of progenitor cells involved in G-CSF–mediated endothelial regeneration with a bone marrow (BM) transplant experiment nor the functional properties of regenerated endothelium have been studied. Methods and Results—Recombinant human G-CSF (100 &mgr;g/kg per day) was injected daily for 14 days starting 3 days before balloon injury in the rat carotid artery. Neointimal formation of denuded vessels on day 14 was markedly attenuated by G-CSF (39% versus the control; P<0.05). Endothelial cell–specific immunostaining revealed an enhancement of re-endothelialization (1.8-fold increase versus the control; P<0.05) and inhibition of extravasation of Evans Blue dye (47%; P=0.02). The regenerated endothelium exhibited acetylcholine-mediated vasodilatation in NO-dependent manner. G-CSF increased the circulating c-Kit+/Flk-1+ cells (9.1-fold; P<0.02), which showed endothelial properties in vitro (acetylated low-density lipoprotein uptake and lectin binding) and incorporated into the regenerated endothelium in vivo. A BM replacement experiment with green fluorescent protein (GFP)–overexpressing cells showed that BM-derived GFP+/CD31+ endothelial cells occupied 39% of the total luminal length in the G-CSF–mediated neo-endothelium (2% in the control). Conclusion—The G-CSF–induced mobilization of BM-derived c-Kit+/Flk-1+ cells contributes to endothelial regeneration, and this cytokine therapy may be a feasible strategy for the promotion of re-endothelialization after angioplasty.

Endovascular Treatment for Infrainguinal Vessels in Patients With Critical Limb Ischemia OLIVE Registry, a Prospective, Multicenter Study in Japan With 12-Month Follow-up

Background—Recent technical advances have made endovascular treatment (EVT) an alternative first-line treatment for critical limb ischemia. Methods and Results—A prospective multicenter study was conducted to evaluate the clinical outcomes of 314 Japanese critical limb ischemia patients (mean age, 73±10 years) with infrainguinal arterial lesions who underwent EVT. Patients were enrolled from December 2009 to July 2011 and were followed-up for 12 months. The primary end point was amputation-free survival (AFS) at 12 months. Secondary end points were anatomic, clinical, and hemodynamic measures, including 12-month freedom from major adverse limb events. The 12-month AFS rate was 74%, with body mass index <18.5 (hazard ratio [HR], 2.22; P=0.008), heart failure (HR, 1.73; P=0.04), and wound infection (HR, 1.89; P=0.03) associated with a poor prognosis for AFS. The 12-month major adverse limb event-free rate was 88%, with hemodialysis (HR, 1.98; P=0.005), heart failure (HR, 1.69; P=0.02), and Rutherford classification 6 (HR, 2.25; P=0.002) associated with a poor prognosis for major adverse limb events. The median time for wound healing was 97 days, with body mass index <18.5 (HR, 0.54; P=0.03) and wound infection (HR, 0.60; P=0.04) being significant risk factors for unhealed wounds after EVT. At 12 months, 34% had undergone reintervention (bypass surgery, 2.6%; repeat EVT, 31.7%), and 73% were major adverse event–free. Conclusions—The high reintervention rate notwithstanding, EVT was an effective treatment for Japanese critical limb ischemia patients with infrainguinal disease, with satisfactory AFS and major adverse limb event-free rates. The results of this study will be helpful for the future evaluation of critical limb ischemia therapy. Clinical Trial Registration—URL: http://www.umin.ac.jp/ctr. Unique identifier: UMIN000002830.

Increased plasma brain natriuretic peptide level as a guide for silent myocardial ischemia in patients with non-obstructive hypertrophic cardiomyopathy

OBJECTIVES We measured plasma atrial/brain natriuretic peptide (ANP/BNP) levels at rest and during exercise and correlated the results with various clinical findings, particularly with myocardial ischemia, in asymptomatic hypertrophic cardiomyopathy (HCM). BACKGROUND In patients with HCM, ANP and BNP levels are elevated and exercise-induced myocardial ischemia is common. However, it has not yet been elucidated how these levels at rest and their change with dynamic exercise are related to ischemia. METHODS Levels of ANP and BNP were measured at rest and at peak exercise during (99m)Tc-tetrofosmin scintigraphy in 31 asymptomatic patients with non-obstructive HCM and in 10 control subjects. RESULTS Levels of ANP and BNP at rest and the change of ANP and BNP levels (PG/ML) from rest to exercise were significantly greater in HCM than in control subjects (ANP: rest, 53.2 +/- 31.8 vs. 11.6 +/- 6.1; exercise, 114.5 +/- 74.8 vs. 28.3 +/- 23.4. BNP: rest, 156.7 +/- 104.1 vs. 9.8 +/- 9.6; exercise, 201.6 +/- 131.5 vs. 13.2 +/- 14.5). Septal perforator compression (SPC) and exercise-induced ischemia were observed, respectively, in 20 (64.5%) and in 19 (61.3%) patients with HCM. The increment of ANP during exercise was similar between HCM subgroups with or without inducible ischemia. However, BNP levels at rest and BNP increments during exercise were significantly greater in the HCM subgroup with inducible ischemia than in the subgroup without (rest, 190.5 +/- 116.2 vs. 103.1 +/- 48.3; exercise, 250.5 +/- 142.2 vs. 124.2 +/- 58.6). Multiple logistic regression analysis revealed that SPC and BNP levels at rest were independently associated with exercise-induced ischemia. CONCLUSIONS Measurement of plasma BNP levels at rest may be useful in predicting silent myocardial ischemia in HCM.

Cilostazol Reduces Angiographic Restenosis After Endovascular Therapy for Femoropopliteal Lesions in the Sufficient Treatment of Peripheral Intervention by Cilostazol Study

Background— It remains unclear whether cilostazol, which has been shown to improve the clinical outcomes of endovascular therapy for femoropopliteal lesions, also reduces angiographic restenosis. Methods and Results— The Sufficient Treatment of Peripheral Intervention by Cilostazol (STOP-IC) study investigated whether cilostazol reduces the 12-month angiographic restenosis rate after percutaneous transluminal angioplasty with provisional nitinol stenting for femoropopliteal lesions. Two hundred patients with femoropopliteal lesions treated from March 2009 to April 2011 at 13 cardiovascular centers were randomly assigned 1:1 to receive oral aspirin with or without cilostazol. The primary end point was 12-month angiographic restenosis rate. Secondary end points were the restenosis rate on duplex ultrasound, the rate of major adverse cardiac events, and target lesion event-free survival. Researchers evaluated all follow-up data and assessed the end points in a blinded fashion. The mean lesion length and reference vessel diameter at the treated segment were 128±86 mm and 5.4±1.4 mm, respectively. The frequency of stent used was similar between groups (88% versus 90% in the cilostazol and noncilostazol group, respectively, P=0.82). During the 12-month follow-up period, 11 patients died and 152 patients (80%) had evaluable angiographic data at 12 months. The angiographic restenosis rate at 12 months was 20% (15/75) in the cilostazol group versus 49% (38/77) in the noncilostazol group (P=0.0001) by intention-to-treat analysis. The cilostazol group also had a significantly higher event-free survival at 12 months (83% versus 71%, P=0.02), although cardiovascular event rates were similar in both groups. Conclusions— Cilostazol reduced angiographic restenosis after percutaneous transluminal angioplasty with provisional nitinol stenting for femoropopliteal lesions. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT00912756; and URL: https://www.umin.ac.jp. Unique identifier: UMIN000002091.

1-Year Results of the ZEPHYR Registry (Zilver PTX for the Femoral Artery and Proximal Popliteal Artery): Predictors of Restenosis.

OBJECTIVES This study sought to assess the rate and predictors of 1-year restenosis after drug-eluting stent implantation for femoropopliteal (FP) lesions in patients with peripheral arterial disease. BACKGROUND Zilver PTX, a paclitaxel-eluting stent for FP lesions, provides superior outcomes to angioplasty and bare-metal stents in clinical trials. However, its real-world outcomes and the associated features remain unclear. METHODS This was a prospective multicenter study enrolling 831 FP lesions (797 limbs, 690 patients) treated by Zilver PTX implantation. The primary endpoint was 1-year restenosis. Secondary endpoints included major adverse limb event and stent thrombosis. RESULTS Mean lesion length was 17 ± 10 cm. One-year restenosis, major adverse limb event, and stent thrombosis rates were 37%, 22%, and 2%, respectively. The generalized linear mixed model showed that lesion length ≥16 cm assessed by angiography and distal external elastic membrane area ≤27 mm(2) and minimum stent area ≤12 mm(2) assessed by intravascular ultrasound were independent risk factors for restenosis. One-year restenosis rates were 15% in cases with none of these risk factors and 50% in those with ≥2 risk factors. CONCLUSIONS The current study demonstrated 1-year real-world outcomes after drug-eluting stent treatment for FP lesions, including challenging ones in clinical practice. Lesion length, external elastic membrane area, and minimum stent area were independent predictors for restenosis. (Zilver PTX for the Femoral Artery and Proximal Popliteal Artery-Prospective Multicenter Registry [ZEPHYR]; UMIN000008433).

Carbon Dioxide–Rich Water Bathing Enhances Collateral Blood Flow in Ischemic Hindlimb via Mobilization of Endothelial Progenitor Cells and Activation of NO-cGMP System

Background—Carbon dioxide–rich water bathing has the effect of vasodilatation, whereas it remains undetermined whether this therapy exerts an angiogenic action associated with new vessel formation. Methods and Results—Unilateral hindlimb ischemia was induced by resecting the femoral arteries of C57BL/J mice. Lower limbs were immersed in CO2-enriched water (CO2 concentration, 1000 to 1200 mg/L) or freshwater (control) at 37°C for 10 minutes once a day. Laser Doppler imaging revealed increased blood perfusion in ischemic limbs of CO2 bathing (38% increase at day 28, P<0.001), whereas NG-nitro-l-arginine methyl ester treatment abolished this effect. Angiography or immunohistochemistry revealed that collateral vessel formation and capillary densities were increased (4.1-fold and 3.7-fold, P<0.001, respectively). Plasma vascular endothelial growth factor (VEGF) levels were elevated at day 14 (18%, P<0.05). VEGF mRNA levels, phosphorylation of NO synthase, and cGMP accumulation in the CO2-bathed hindlimb muscles were increased (2.7-fold, 2.4-fold, and 3.4-fold, respectively) but not in forelimb muscles. The number of circulating Lin−/Flk-1+/CD34− endothelial-lineage progenitor cells was markedly increased by CO2 bathing (24-fold at day 14, P<0.001). The Lin−/Flk-1+/CD34− cells express other endothelial antigens (endoglin and VE-cadherin) and incorporated acetylated LDL. Conclusions—Our present study demonstrates that CO2 bathing of ischemic hindlimb causes the induction of local VEGF synthesis, resulting in an NO-dependent neocapillary formation associated with mobilization of endothelial progenitor cells.

ERK5 is a target for gene amplification at 17p11 and promotes cell growth in hepatocellular carcinoma by regulating mitotic entry

Using high‐density oligonucleotide microarrays, we investigated DNA copy‐number aberrations in cell lines derived from hepatocellular carcinomas (HCCs) and detected a novel amplification at 17p11. To identify the target of amplification at 17p11, we defined the extent of the amplicon and examined HCC cell lines for expression of all seven genes in the 750‐kb commonly amplified region. Mitogen‐activated protein kinase (MAPK) 7, which encodes extracellular‐regulated protein kinase (ERK) 5, was overexpressed in cell lines in which the gene was amplified. An increase in MAPK7 copy number was detected in 35 of 66 primary HCC tumors. Downregulation of MAPK7 by small interfering RNA suppressed the growth of SNU449 cells, the HCC cell line with the greatest amplification and overexpression of MAPK7. ERK5, phosphorylated during the G2/M phases of the cell cycle, regulated entry into mitosis in SNU449 cells. In conclusion, our results suggest that MAPK7 is likely the target of 17p11 amplification and that the ERK5 protein product of MAPK7 promotes the growth of HCC cells by regulating mitotic entry.

3-Year Outcomes of the OLIVE Registry, a Prospective Multicenter Study of Patients With Critical Limb Ischemia: A Prospective, Multi-Center, Three-Year Follow-Up Study on Endovascular Treatment for Infra-Inguinal Vessel in Patients With Critical Limb Ischemia.

OBJECTIVES This study sought to investigate the 3-year follow-up results of OLIVE registry patients. BACKGROUND Although favorable 12-month clinical outcomes after endovascular therapy (EVT) in OLIVE registry patients with critical limb ischemia (CLI) from infrainguinal disease have been reported, long-term results after EVT remain unknown. METHODS This was a prospective multicenter registry study that consecutively enrolled patients who received infrainguinal EVT for CLI. The primary outcome was 3-year amputation-free survival (AFS), whereas secondary outcome measures were 3-year freedom from major adverse limb events (MALE), wound-free survival, and wound recurrence rate. Prognostic predictors for each outcome were also elucidated by Cox proportional hazard regression analysis or the log-rank test. RESULTS The completion rate of 3-year follow-up was 95%. Three-year AFS, freedom from MALE, and wound-free survival rates were 55.2%, 84.0%, and 49.6%, respectively. Wound recurrence out to 3 years was 43.9%. After multivariable analysis, age (hazard ratio [HR]: 1.43, p = 0.001), body mass index ≤18.5 (HR: 2.17, p = 0.001), dialysis (HR: 2.91, p < 0.001), and Rutherford 6 (HR: 1.64, p = 0.047) were identified as predictors of 3-year major amputation or death. Statin use (HR: 0.28, p = 0.02), Rutherford 6 (HR: 2.40, p = 0.02), straight-line flow to the foot (HR: 0.27, p = 0.001), and heart failure (HR: 1.96, p = 0.04) were identified as 3-year MALE predictors. Finally, CLI due to isolated below-the-knee lesion was a wound recurrence predictor (HR: 4.28, p ≤ 0.001). Three-year survival, freedom from major amputation, and reintervention rates were 63.0%, 87.9%, and 43.2%. CONCLUSIONS In CLI patients with infrainguinal lesions, 3-year clinical results of EVT were reasonable despite high reintervention and moderate ulcer recurrence rate. (A Prospective, Multi-Center, Three-Year Follow-Up Study on Endovascular Treatment for Infra-Inguinal Vessel in Patients With Critical Limb Ischemia [OLIVE 3-Year Follow-Up Study]; UMIN000014759).

Assessment of left ventricular diastolic function by gated single-photon emission tomography: comparison with Doppler echocardiography

Gated single-photon emission tomography (SPET) is not yet an established procedure for the evaluation of left ventricular (LV) diastolic function. This study examined diastolic function derived from gated SPET in comparison with an established diagnostic tool, Doppler echocardiography. We examined 37 consecutive patients with normal sinus rhythm who underwent gated technetium-99m tetrofosmin SPET. A gated SPET program was used with a temporal resolution of 32 frames per R-R interval. We obtained the Doppler transmitral flow velocity waveform immediately before gated SPET image acquisition. Patients who showed a ratio of peak early transmitral flow velocity to atrial flow velocity (E/A) of >1 or whose R-R intervals differed by >5% between Doppler echocardiography and gated SPET were excluded from this investigation. We compared diastolic indices and presumed corresponding intervals in diastole using the two methods. The peak filling rate (PFR) derived from gated SPET correlated with the Doppler peak velocity of the early transmitral flow (E) wave (r=0.65) and deceleration of the E wave (r=0.71). The time to PFR and percent atrial contribution to LV filling from gated SPET correlated excellently with the Doppler LV isovolumic relaxation time (r=0.93) and the E/A ratio (r=−0.85), respectively. There was a significant linear correlation in all the intervals from the R wave to the presumed corresponding diastolic points. The point of PFR in gated SPET and the peak of the E wave in Doppler echocardiography generally coincided. The onset of filling in gated SPET tended to be closer to the second heart sound than the start of the E wave in Doppler echocardiography. We conclude that gated SPET permits the assessment of not only myocardial perfusion and LV systolic function but also diastolic function, although there may be some errors in detection of the precise beginning of LV filling.