Search

Remote ischemic preconditioning (RIPC) is a promising strategy for protecting against ischemic reperfusion injury. This study is a secondary analysis of a randomized study that aimed to evaluate the effect of RIPC on the early increase in serum creatinine (SCr) following percutaneous coronary intervention (PCI), which is associ-ated with contrast-induced acute kidney injury. Patients with stable angina undergoing elective PCI were assigned to control, RIPC, and continuous infusion of nicorandil (nicorandil) groups. The endpoint of this study was the incidence of the early increase in SCr, a predictor of contrast-induced acute kidney injury, which was defined as either a > 20% or absolute increase by 0.3 mg/dl of SCr levels after 24 h of PCI. This study included 220 patients for whom a dataset of SCr values was available. The incidence of the early increase in SCr was significantly lower in the RIPC than in the control (1.3% vs 10.8%, p = 0.03) group, but was not significantly different between the nicorandil and control groups. In multivariate analysis, RIPC remained a significant fac-tor associated with a reduction in the incidence of early increase in SCr. RIPC reduces the incidence of early increase in SCr in patients with stable angina following elective PCI., Competing Interests: No potential conflict of interest relevant to this article was reported.

Despite intensive lipid-lowering interventions, patients treated with statins develop atherosclerotic cardiovascular disease (ASCVD), and these patients have an increased risk of developing recurrent cardiovascular events during follow-up. Therefore, there is a need to focus on the residual risks in patients in statin therapy to further reduce ASCVD. The aim of this study was to retrospectively investigate the 10-year trend (2011-2019) regarding changes in polyunsaturated fatty acids (PUFAs) in patients with acute coronary syndrome (ACS) in a single center. We included 686 men and 203 women with ACS admitted to Kagawa Prefectural Central Hospital. Plasma PUFAs, including eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), arachidonic acid (AA), and dihomo-γ-linolenic acid (DGLA), were measured at admission for suspected ACS. A secular decreasing trend in the levels of EPA and DHA and the EPA/AA ratio, but not of AA and DGLA, was observed. The analyses based on age (>70 or <70 years) and sex showed that the decreasing trend in the levels of EPA and DHA did not depend on age and remained significant only in men. Further studies are needed to obtain robust evidence to justify that the administration of n-3 PUFA contributes to the secondary prevention of ACS.

Background: Cardiovascular events in patients with atrial fibrillation (AF) can be lowered by catheter ablation. We hypothesized the underlying mechanism was improvement in renal and endothelial function corresponding to AF burden, and investigated whether restoration of sinus rhythm (SR) after ablation affected these functions according to AF type., Methods and Results: We prospectively measured estimated glomerular filtration rate (eGFR), urinary albumin-to-creatinine ratio (UACR), and reactive hyperemia index (RHI) in 358 consecutive patients with AF before and 6 and 12 months after the ablation. For each AF type [paroxysmal AF (PAF), n = 229, and persistent AF (PeAF), n = 129], we evaluated changes in these markers and influence of chronic kidney disease (CKD). The eGFR and natural logarithm-transformed (ln) UACR improved at 6 months in the PeAF group (68.7 ± 18.7-71.8 ± 18.9 mL/min/1.73 m 2 , p = 0.003 and 3.1±1.6 to 2.8±1.5, p < 0.001, respectively) and remained unchanged in the PAF group. Among the PeAF patients, recurrent AF was identified in 41, but only transiently in 38 patients. PeAF at baseline independently predicted increased eGFR [odds ratio (OR)=2.13, 95 % confidence interval (CI) 1.35-3.40, p = 0.001] and decreased UACR (OR=1.94, 95 % CI 1.05-3.58, p = 0.033). In the PeAF patients with CKD, ln-RHI significantly increased at 6 months after the ablation, and the change (Δ) in ln-RHI was significantly correlated with the ΔeGFR (r=0.35, p = 0.03)., Conclusions: SR restoration after ablation was associated with an improved eGFR and UACR in PeAF patients, but not PAF patients. In PeAF patients with CKD, an improved endothelial function after ablation was associated with an improved renal function., (Copyright © 2020 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.)

Background: Remote ischemic preconditioning (RIPC) is promising for preventing periprocedural myocardial damage (pMD) in patients undergoing percutaneous coronary intervention (PCI). However, the impact of RIPC on pMD on smokers is not well elucidated. The aim of this study was to investigate an association between tobacco smoking and RIPC on pMD in patients planning to undergo PCI., Methods: This study used data from a multicenter randomized controlled trial involving patients with stable angina who planned to undergo elective PCI. We analyzed data for 262 patients in the control ( n  = 133) and upper-limb RIPC ( n  = 129) groups, including 166 current or former smokers. The major outcome was the pMD incidence following PCI, with pMD defined as an elevated level of highly sensitive cardiac troponin T or a creatine kinase myocardial band 12 or 24 h after PCI., Results: The incidence of pMD was significantly lower in the upper-limb RIPC group than in the control group (28/83 patients [33.8%] vs. 43/83 patients [51.8%], respectively; p  = 0.018). In a multiple logistic regression model, tobacco smoking was an independent predictor of interacting with and enhancing the effect of RIPC on reducing the incidence of pMD after PCI (regression coefficient, -0.4 [95% confidence interval, -0.74 to -0.082]; p  = 0.015)., Conclusions: Tobacco smoking may have a beneficial effect on RIPC against pMD after PCI.

Background: The effect of remote ischemic preconditioning (RIPC) on periprocedural myocardial damage (pMD) in patients undergoing percutaneous coronary intervention (PCI) is controversial. The aim of this study was to investigate the effect of RIPC or intravenous nicorandil on pMD following elective PCI in a subgroup of patients with complex coronary lesions from a multicenter randomized controlled trial.Methods and Results:Patients with stable angina who underwent elective PCI were assigned to 3 groups: control, upper-limb RIPC or intravenous nicorandil. The major outcome was pMD incidence following PCI, with pMD defined as an elevated level of high-sensitivity cardiac troponin T or creatine kinase myocardial band at 12 or 24 h after PCI. A total of 171 patients with complex coronary lesions (ACC-AHA coronary classification type B2 or C) were analyzed. The incidence of pMD following PCI was significantly lower in the RIPC group than in the control group (44.4% vs. 66.1%; P=0.023). The adjusted odds ratio (95% confidence interval) for pMD in the RIPC vs. the controls was 0.41 (0.18-0.94). The incidence of pMD in the nicorandil group was not significantly reduced compared with the control groups., Conclusions: This substudy suggested that RIPC prior to PCI prevented pMD in patients with complex coronary lesions. Further investigation in a multicenter prospective study is needed to confirm these results.

Background: Atrial fibrillation (AF) is associated with endothelial dysfunction. Studies have shown the incidence of cardiovascular events to be greater in patients with persistent AF (PeAF) than paroxysmal AF (PAF)., Objective: The aim of this study was to investigate whether endothelial dysfunction and the impact of catheter ablation on the endothelial function differs between PAF and PeAF., Methods: We prospectively measured the endothelial function by reactive hyperemia peripheral arterial tonometry (RH-PAT) in 103 PAF, 75 PeAF, and 51 control patients at baseline, with follow-up in the AF patients at 6 and 12months after the catheter ablation., Results: The log-transformed RH-PAT index (ln RHI) was the highest in the control group, followed by the PAF and PeAF (0.67±0.23, 0.57±0.29, and 0.45±0.3, respectively, p<0.001) groups. PeAF was determined to be an independent factor of endothelial dysfunction (ln RHI <0.55) even after adjustment for the conventional cardiovascular risk factors. For 12months after the catheter ablation, 102 (99%) PAF and 72 (96%) PeAF patients maintained sinus rhythm. On average, the ln RHI in the PAF group did not change during the follow-up, but it significantly increased in the PeAF group to a level comparable to that of the PAF patients 6months after the catheter ablation (0.53±0.28, p=0.034), and maintained the same level at 12months after the catheter ablation., Conclusions: The persistent form of AF may independently contribute to endothelial dysfunction. In addition, by catheter ablation, the maintenance of sinus rhythm may protect against exacerbations of endothelial dysfunction., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Background: The effect of remote ischemic preconditioning (RIPC) and nicorandil on periprocedural myocardial injury (pMI) in patients with planned percutaneous coronary intervention (PCI) remains controversial. The aim of this randomized trial was to evaluate the effect of RIPC or nicorandil on pMI following PCI in patients with stable coronary artery disease (CAD) compared with a control group., Methods: Patients with stable CAD who planned to undergo PCI were assigned to a 1:1:1 ratio to control, RIPC, or intravenous nicorandil (6mg/h). Automated RIPC was performed by a device, which performs intermittent arm ischemia through three cycles of 5min of inflation and 5min of deflation of a pressure cuff. The primary outcome was the incidence of pMI, determined by an elevation in high-sensitive troponin T or creatine kinase myocardial band at 12 or 24h after PCI. The secondary outcomes were ischemic events during PCI and adverse clinical events at 8months after PCI., Results: A total of 391 patients were enrolled. The incidence of pMI following PCI was not significantly different between the control group (48.9%) and RIPC group (39.5%; p=0.14), or between the control group and nicorandil group (40.3%; p=0.17). There were no significant differences in ischemic events during PCI or adverse clinical events within 8months after PCI among the three groups., Conclusions: This study demonstrated moderate reductions in biomarker release and pMI by RIPC or intravenous nicorandil prior to the PCI consistently, but may have failed to achieve statistical significance because the study was underpowered., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Background: Early initiation of EPA treatment in combination with a statin within 24h after percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (MI) reduces inflammation and ventricular arrhythmia compared with statin monotherapy; however, the impact of early initiation of EPA treatment on cardiovascular events is unclear. We determined whether early eicosapentaenoic acid (EPA) treatment in patients with acute coronary syndrome (ACS) reduces adverse cardiovascular events., Methods: This prospective, open-label, blind end point-randomized trial consisted of 241 patients with ACS. Patients were randomly assigned to receive pitavastatin (2mg/day) with or without 1800mg/day of EPA initiated within 24h after PCI. The primary endpoint was defined as cardiovascular events occurring within 1year, including death from a cardiovascular cause, nonfatal stroke, nonfatal MI and revascularization., Results: The mean EPA/arachidonic acid ratio at follow-up was 0.40 in the control group and 1.15 in the EPA group. A primary endpoint event occurred in 11 patients (9.2%) in the EPA group and 24 patients (20.2%) in the control group (absolute risk reduction, 11.0%; hazard ratio, 0.42; 95% confidence interval, 0.21 to 0.87; P=0.02). Notably, death from a cardiovascular cause at 1year was significantly lower in the EPA group than in the control group (0.8% vs. 4.2%, P=0.04)., Conclusions: Early initiation of treatment with EPA combined with statin after successful primary PCI reduced cardiovascular events after ACS., Clinical Trial Registration: UMIN Clinical Trials Registry (UMIN-CTR); Registry Number, UMIN000016723; URL, http://www.umin.ac.jp/ctr/index-j.htm., (Copyright © 2016 Swiss Tropical and Public Health Institute. Published by Elsevier Ireland Ltd.. All rights reserved.)

Background and Aim: The increase in proprotein convertase subtilisin/kexin type 9 (PCSK9) leads to low-density lipoprotein (LDL) receptor degradation. Statins significantly reduce LDL-cholesterol levels, but upregulate PCSK9. This study evaluated the effect of ezetimibe monotherapy or ezetimibe in combination with a statin on serum levels of PCSK9 in patients with type 2 diabetes and hypercholesterolemia., Methods: Ezetimibe treatment was given to ten patients with diabetes without statin therapy and ten patients with statin therapy. Plasma levels of PCSK9 were examined at baseline and 24 weeks after treatment., Results: At baseline, PCSK9 concentrations in patients with statin therapy were significantly higher than those in patients without statin use and in control subjects [median (25th-75th percentile) 411 (272-467) and 382 (356-453) ng/mL, respectively, p < 0.01]. After ezetimibe treatment for 24 weeks, LDL-cholesterol, triglyceride and remnant-like lipoprotein cholesterol were significantly decreased in both groups. However, PCSK9 concentration did not change compared with baseline measurements in both groups. The percentage change in LDL-cholesterol after ezetimibe therapy for 24 weeks was not correlated with the percentage change in PCSK9 concentration., Conclusion: Ezetimibe may reduce LDL-cholesterol levels without affecting PCSK9 in patients with type 2 diabetes and hypercholesterolemia.

Background: Ambulatory measurement of intrathoracic impedance (ITI) with an implanted device may detect increases in pulmonary fluid retention early, but the clinical utility of this method is not well established. The goal of this study was to test whether conventional ITI-derived parameters can diagnose fluid retention that may cause early stage heart failure (HF)., Methods and Results: HF patients implanted with high-energy devices with OptiVol (Medtronic) monitoring were enrolled in this study. Patients were monitored remotely. At both baseline and OptiVol alert, patients were assessed on standard examinations, including analysis of serum brain natriuretic peptide (BNP). From April 2010 to August 2011, 195 patients from 12 institutes were enrolled. There were 154 primary OptiVol alert events. BNP level at the alerts was not significantly different from that at baseline. Given that ITI was inversely correlated with log BNP, we added a criterion specifying that the OptiVol alert is triggered only when ITI decreases by ≥4% from baseline. This change improved the diagnostic potential of increase in BNP at OptiVol alert (sensitivity, 75%; specificity, 88%)., Conclusions: BNP increase could not be identified based on OptiVol alert. Decrease in ITI ≥4% compared with baseline, in addition to the alert, however, may be a useful marker for the likelihood of HF (Clinical trial info: UMIN000003351).

Objective: We examined whether early loading of eicosapentaenoic acid (EPA) reduces clinical adverse events by 1 month, accompanied by a decrease in C-reactive protein (CRP) values in patients with acute myocardial infarction (MI)., Background: Acute MI triggers an inflammatory reaction, which plays an important role in myocardial injury. EPA could attenuate the inflammatory response., Methods: This prospective, open-label, blinded endpoint, randomized trial consisted of 115 patients with acute MI. They were randomly assigned to the EPA group (57 patients) and the control group (58 patients). After percutaneous coronary intervention (PCI), 1800 mg/day of EPA was initiated within 24h. The primary endpoint was composite events, including cardiac death, stroke, re-infarction, ventricular arrhythmias, and paroxysmal atrial fibrillation within 1 month., Results: Administration of EPA significantly reduced the primary endpoint within 1 month (10.5 vs 29.3%, p=0.01), especially the incidence of ventricular arrhythmias (7.0 vs 20.6%, p=0.03). Peak CRP values after PCI in the EPA group were significantly lower than those in the control group (median [interquartile range], 8.2 [5.6-10.2] mg/dl vs 9.7 [7.6-13.9] mg/dl, p<0.01). Logistic regression analysis showed that EPA use was an independent factor related to ventricular arrhythmia until 1 month, with an odds ratio of 0.29 (95% confidence interval, 0.09 to 0.96, p=0.04)., Conclusions: Early EPA treatment after PCI in the acute stage of MI reduces the incidence of ventricular arrhythmias, and lowers CRP values., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

Background: Several lines of evidence suggest that atrial fibrillation (AF) may be a consequence of vascular disease. We investigated the relationship between cardio-ankle vascular index (CAVI), a new index of arterial stiffness, and the presence of paroxysmal AF (PAF)., Methods and Results: 181 outpatients (91 patients with PAF and 90 age- and gender-matched subjects without PAF) were analysed for their sinus rhythm. The CAVI was significantly higher in patients with PAF than in subjects without PAF (9.0±1.0 vs 8.7±0.8, p<0.01). In all subjects, the CAVI was significantly correlated with the left ventricular mass index (r=0.30, p<0.01), left atrial diameter (r=0.22, p<0.01), and augmentation index, a parameter of wave reflection (r=0.32, p<0.01), in addition to age, systolic blood pressure and pulse pressure. Logistic analysis demonstrated that the CAVI was independently associated with PAF even after adjustment for confounding factors. The adjusted OR of PAF was 1.8 for each unit increase in the CAVI (p=0.01)., Conclusions: Our finding suggests that increased arterial stiffness may be involved in the maintenance of AF.

The association between circulating adipocyte fatty acid-binding protein (A-FABP) levels and coronary artery disease (CAD) is reported. We assessed whether plasma A-FABP levels are associated with angiographic coronary lesion morphology in patients with stable CAD. Serum A-FABP levels were analyzed in 115 patients with stable CAD (mean age 69 ± 10 years; 80 % men). These patients were angiographically studied and divided into two groups: simple lesions (n = 34) and complex lesions (n = 81). We also compared 50 age- and gender-matched controls with no evidence of CAD. Serum A-FABP levels in patients with stable CAD were significantly higher than those in controls. In patients with stable CAD, serum A-FABP levels were significantly higher in patients with complex lesions than in those with simple lesions: median (25th-75th percentile), 23.4 (17.7-30.8) vs 18.2 (12.2-24.7) ng/ml, P < 0.01. Serum A-FABP levels were also significantly associated with angiographic scores of extent of coronary lesion (r = 0.21, P = 0.02). Multiple logistic analysis that included dyslipidemia, statin therapy, and extent score demonstrated that serum A-FABP was independently associated with complex lesions. The multiple adjusted odds ratio for a complex lesion with a serum A-FABP level (per doubling) was 2.38 (95 % confidence interval, 1.03-6.41; P = 0.03). High serum A-FABP levels were significantly associated with complex coronary lesions in patients with stable CAD, suggesting that high A-FABP levels may be involved in coronary plaque vulnerability.

Diastolic dysfunction of the heart is correlated with cardiac mortality. Serum cystatin C (CysC) is an endogenous marker of kidney function. It is not clear whether serum CysC is associated with diastolic dysfunction in patients with varying cardiac conditions with concomitant diastolic abnormalities and preserved ejection fraction (EF). The authors measured serum CysC levels in patients with cardiac diseases and examined the relationships between serum CysC levels and diastolic function. Serum CysC was measured and echocardiography was performed in 124 consecutive patients with cardiac diseases. Transmitral flow (TMF) patterns surrogating diastolic function were categorized into two groups: a normal group and an abnormal group. Serum CysC and BNP showed a significant positive correlation. There were no significant differences in serum CysC among those cardiac diseases. Seventy-eight patients with cardiac disease and preserved EF (left ventricular EF ≥50%) and without renal dysfunction (estimated glomerular filtration rate ≥60 mL/minute/1.73 m(2) ) were examined. Multivariate linear regression analysis demonstrated that left atrium diameter and abnormal TMF patterns were independent determinants of serum CysC. Furthermore, patients with elevated serum CysC levels had poor prognosis. Serum CysC is associated with diastolic dysfunction in patients with various cardiac diseases and preserved EF. Serum CysC might be a biomarker of cardiac diastolic dysfunction in patients with preserved EF., (© 2013 Wiley Periodicals, Inc.)

Adipocyte fatty acid binding protein (A-FABP) has been reported to be involved in insulin resistance, lipid metabolism, and atherosclerosis; however, little is known about the effect of medication on the change in circulating A-FABP in human subjects. We evaluated the effects of angiotensin II type 1 receptor blocker (ARB) on arterial stiffness and its association with serum A-FABP in patients with hypertension. Thirty patients newly diagnosed with essential hypertension were treated with olmesartan (20 mg/day), an ARB, for 6 months. Serum levels of A-FABP and high-sensitivity C-reactive protein (hsCRP) were examined and the cardio-ankle vascular index (CAVI), which is a marker of arterial stiffness, was also determined. Serum A-FABP at baseline was significantly correlated with the body mass index (r = 0.45, P = 0.01), homeostasis model assessment as a marker of insulin resistance (r = 0.53, P < 0.01), and systolic blood pressure (r = 0.37, P = 0.047), and tended to be correlated with low-density lipoprotein cholesterol, triglyceride, and CAVI. Olmesartan treatment resulted in a significant decrease in CAVI, serum A-FABP levels, and hsCRP, besides a significant reduction of blood pressure. Multiple regression analysis revealed that the change in CAVI was independently correlated with the change in serum A-FABP. Olmesartan ameliorated arterial stiffness in patients with hypertension, which may be involved in the reduction of serum A-FABP.

Introduction: The optimal combination treatment for hypertension has not been established. We investigated the effect of a calcium channel blocker or a diuretic added to angiotensin II receptor blockers (ARBs) on the augmentation index (AI), as a marker of arterial stiffness and wave reflection, in hypertensive patients., Methods: Thirty-seven patients treated with ARBs were randomly allocated to either of the 2 groups receiving an ARB plus azelnidipine (AZ group) or trichlormethiazide (TCM group). Changes in brachial blood pressure (BP), AI, high-sensitive C-reactive protein (hsCRP), and serum asymmetric dimethylarginine, as an endogenous nitric oxide synthase inhibitor, were determined., Results: Systolic and diastolic blood pressure after 6 months were significantly reduced in both the groups similarly; however, after adjustment for baseline covariates, the extent of the reduction in AI (%) in the AZ group was significantly greater than in the TCM group (between-group difference was 3.2; 95%CI: 0.2-6.3; P = 0.03). The reduction of high-sensitive C-reactive protein (mg/L) and serum asymmetric dimethylarginine (micromol/L) was significantly greater in the AZ group than in the TCM group (between-group difference was 0.18 and 0.05; 95%CI: -0.01 to 0.36 and -0.01 to 0.11; P = 0.04 and 0.02, respectively). Further, when patients were analyzed according to age younger than 60 years or older than 60 years, the reduction in AI in the AZ group aged older than 60 years was significantly greater than in the TCM group., Conclusion: The results suggest that azelnidipine has a more beneficial effect on vascular properties in combination therapy with ARB than trichlormethiazide.

Angiogenesis plays an essential role in tumor growth. This study investigated expression of the noncollagenous domain of alpha3(IV) collagen (alpha3(IV)NC1) transduced into tumors and its inhibition of tumor growth. We hypothesized that if a human telomerase reverse transcriptase (hTERT) promoter-driven RGD motif containing alpha3(IV)NC1 (hTERT/RGD-alpha3(IV)NC1) were expressed in telomerase-expressing tumor cells, it would inhibit tumor growth by its anti-angiogenic property. Adenoviral transduction of hTERT/RGD-alpha3(IV)NC1 expressed RGD-alpha3(IV)NC1 in hTERT-positive tumor cell lines. However, hTERT/RGD-alpha3(IV)NC1 did not express RGD-alpha3(IV)NC1 in hTERT-negative cells such as keratinocytes and fibroblasts. The secreted RGD-alpha3(IV)NC1 in the conditioned medium from tumor cells inhibited cell proliferation as well as tube formation in cultured endothelial cells, but had no effect on other types of cells. In an in vivo model, adenoviral hTERT/RGD-alpha3(IV)NC1 gene therapy showed limited expression of RGD-alpha3(IV)NC1 in tumors and resulted in a significant decrease of vessel density in tumors. The growth of subcutaneous (s.c.) tumors in nude mice was significantly suppressed by treatment with hTERT/RGD-alpha3(IV)NC1. In addition, long-term inhibition of tumor growth was achieved by intermittent administration of hTERT/RGD-alpha3(IV)NC1. In conclusion, our findings demonstrate that tumor-specific anti-angiogenic gene therapy utilizing RGD-alpha3(IV)NC1 under the hTERT promoter inhibited angiogenesis in tumors, resulting in an antitumor effect.

Following vascular injury, basement membrane (BM) components of the blood vessels are exposed to circulating cells and may contribute to hemostasis and/or thrombosis. Laminins 8 (LN-8) (alpha4beta1gamma1) and 10 (LN-10) (alpha5beta1gamma1) are major laminin isoforms of the endothelial BM, and LN-8 is also secreted by activated platelets. In the present study, we demonstrate synthesis of alpha5-laminins LN-10 and LN-11 (alpha5beta2gamma1) by megakaryocytic cells, and intracellular expression of these laminin isoforms in blood platelets. In contrast to platelet LN alpha4 chain that had an apparent molecular weight of 180 kDa and associated mostly to LNbeta1 chain, platelet LNalpha5 consisted of 300/350 kDa polypeptides and associated mainly to LNbeta2. Both alpha4- and alpha5-laminins were secreted by platelets following stimulation. When compared to recombinant human (rh) LN-8, rhLN-10 was much more adhesive to platelets, though adhesion to both proteins was largely mediated via alpha6beta1 integrin. In spite of their adhesive properties, rhLN-8 and rhLN-10 induced neither P-selectin expression nor cell aggregation, two signs of platelet activation. This study demonstrates synthesis/expression of heterotrimeric alpha5-laminins in hematopoietic/blood cells, and provides evidence for the adhesive, but not activating, role of endothelial laminin isoforms in platelet biology.

Several peptide sequences in laminin alpha1, the alpha-chain of laminin (Ln)-1, mediate biological responses in vitro, but Ln-1 is rare in vivo. Since Ln-5 and Ln-10, which contain the alpha3 and alpha5 chains, respectively, are the most prominent laminin heterotrimers in normal adult tissues and few functional domains in other laminin chains have been identified, we are investigating the alpha3 and alpha5 chains for biological activities. Incubation of mouse macrophages with the laminin alpha5 peptide AQARSAASKVKVSMKF resulted in marked increase in matrix metalloproteinase (MMP)-9 mRNA and gelatinolytic activity in the conditioned media, whereas the corresponding alpha3 peptide QQARDAANKVAIPMRF had no effect. AQARSAASKVKVSMKF also induced expression of MMP-14, while MMP-2, MMP-3, MMP-7, MMP-12, and MMP-13 were not induced by this peptide. Deletion analyses indicated that a minimal sequence of ASKVKVSMKF was sufficient for increasing MMP-9 expression. AQARSAASKVKVSMKF was also chemotactic for neutrophils and macrophages in vitro, and induced accumulation of neutrophils and macrophages in lung airspaces in vivo following intranasal instillation into mice. Comparable accumulation occurred in MMP-9-deficient mice, indicating that MMP-9 was not required for AQARSAASKVKVSMKF-induced inflammatory cell emigration in the lung. A scrambled version of the minimal peptide, KAKSFVMVSK, was inactive. These data indicate that laminin alpha5-derived peptides can induce inflammatory cell chemotaxis and metalloproteinase activity.

We have produced human laminin-8 (alpha4beta1gamma1) using recombinant technology. Approximately half of the recombinant laminin-8 (rLN-8) molecules were found to have a chondroitin sulphate modification in the alpha4 chain. The substituted and non-substituted forms were separated and tested for cell adhesion activity. Lower cell adhesion promoting activity was seen for the substituted form, but the integrin receptor utilization was similar. We also found the human rLN-8 to behave identically in cell adhesion assays compared to a human/mouse hybrid variant of rLN-8., (Copyright 2002 Elsevier Science B.V. and International Society of Matrix Biology)

The laminin (LN) family of large heterotrimeric extracellular matrix glycoproteins has multiple functions: LNs take part in the regulation of processes such as cell migration, differentiation, and proliferation, in addition to contributing to the structure of basement membranes. LN-10, composed of alpha5, beta1, and gamma1 chains, is widely distributed in most basement membranes of both epithelia and endothelia. We determined the complete human cDNA sequence for the LN alpha5 chain and produced recombinant human LN-10 (rLN-10) in HEK293 cells by triple transfection of full-length cDNAs encoding the human LN alpha5, beta1, and gamma1 chains. The rLN-10 was purified using affinity chromatography and had an apparent molecular mass of approximately 800 kDa in SDS-PAGE and a native domain structure in rotary shadowing electron microscopy. By using function-blocking monoclonal antibodies, integrin alpha(3)beta(1) was found to be a major mediator of adhesion of HT-1080 and human saphenous vein endothelial cells. Human saphenous vein endothelial cells adhered more strongly to rLN-10 than to LN-1 and LN-8 and showed better migration on rLN-10, compared with several other matrices. Considering the cell adhesive and migration-promoting properties of rLN-10 on endothelial cells, this molecule could be useful in improving the biocompatibility and endothelialization of vascular grafts.