Machine learning-based gait analysis to predict clinical frailty scale in elderly patients with heart failure.

Aims: Although frailty assessment is recommended for guiding treatment strategies and outcome prediction in elderly patients with heart failure (HF), most frailty scales are subjective, and the scores vary among raters. We sought to develop a machine learning-based automatic rating method/system/model of the clinical frailty scale (CFS) for patients with HF. Methods and results: We prospectively examined 417 elderly (≥75 years) with symptomatic chronic HF patients from 7 centres between January 2019 and October 2023. The patients were divided into derivation (n = 194) and validation (n = 223) cohorts. We obtained body-tracking motion data using a deep learning-based pose estimation library, on a smartphone camera. Predicted CFS was calculated from 128 key features, including gait parameters, using the light gradient boosting machine (LightGBM) model. To evaluate the performance of this model, we calculated Cohen's weighted kappa (CWK) and intraclass correlation coefficient (ICC) between the predicted and actual CFSs. In the derivation and validation datasets, the LightGBM models showed excellent agreements between the actual and predicted CFSs [CWK 0.866, 95% confidence interval (CI) 0.807-0.911; ICC 0.866, 95% CI 0.827-0.898; CWK 0.812, 95% CI 0.752-0.868; ICC 0.813, 95% CI 0.761-0.854, respectively]. During a median follow-up period of 391 (inter-quartile range 273-617) days, the higher predicted CFS was independently associated with a higher risk of all-cause death (hazard ratio 1.60, 95% CI 1.02-2.50) after adjusting for significant prognostic covariates. Conclusion: Machine learning-based algorithms of automatically CFS rating are feasible, and the predicted CFS is associated with the risk of all-cause death in elderly patients with HF.

Applicability of new proposed criteria for iron deficiency in Japanese patients with heart failure.

AIMS: Iron deficiency (ID) is a common co-morbidity in patients with heart failure (HF). A recent study showed that ID defined by the current guideline criteria was not associated with worse clinical outcomes, and new ID criteria was proposed in patients with HF. However, the external applicability of the new proposed criteria is unclear. We sought to investigate the applicability of the proposed ID criteria in Japanese patients with HF. METHODS AND RESULTS: We prospectively examined 763 patients with chronic HF from a Japanese multicentre registry. The proposed ID criteria were transferrin saturation (TSAT) < 20% and serum iron ≤13 mmol/L and the guideline ID criteria were serum ferritin <100 ng/mL or, when ferritin was 100-299 ng/mL, TSAT <20%. Among all patients (456 male, mean age 71 ± 13 years), 213 (28%) and 444 (58%) met the proposed and guideline ID criteria, respectively. During a median follow-up period of 436 days (interquartile range 297-565), the primary outcome of all-cause mortality occurred in 56 (7%) patients. There was no significant difference in the primary outcome between the patients with and without guideline ID criteria (P = 0.32), whereas patients with serum iron ≤10 µmol/L showed higher mortality (P = 0.002). In multivariable Cox regressions, the proposed ID criteria, but not guideline ID criteria, were independently associated with the risk of all-cause mortality (HR 2.01, 95% CI 1.16-3.51 and HR 1.32, 95% CI 0.76-2.28, respectively), even after adjustment for covariates. CONCLUSIONS: When defined by the proposed criteria and not the guideline criteria, ID was associated with higher mortality in patients with chronic HF, suggesting that the proposed ID criteria is applicable to the Japanese population.

Demonstration of Improved Renal Congestion After Heart Failure Treatment on Renal Perfusion Imaging With Contrast-Enhanced Ultrasonography.

Background: Renal congestion is a critical pathophysiological component of congestive heart failure (CHF). Methods and Results: To quantify renal congestion, contrast-enhanced ultrasonography (CEUS) was performed at baseline and after treatment in 11 CHF patients and 9 normal subjects. Based on the time-contrast intensity curve, time to peak intensity (TTP), which reflects the perfusion rate of renal parenchyma, and relative contrast intensity (RCI), an index reflecting renal blood volume, were measured. In CHF patients, TTP at baseline was significantly prolonged compared with that in controls (cortex, 10.8±3.5 vs. 4.6±1.2 s, P<0.0001; medulla, 10.6±3.0 vs. 5.1±1.6 s, P<0.0001), and RCI was lower than that in controls (cortex, -16.5±5.2 vs. -8.8±1.5 dB, P<0.0001; medulla, -22.8±5.2 vs. -14.8±2.4 dB, P<0.0001). After CHF treatment, RCI was significantly increased (cortex, -16.5±5.2 to -11.8±4.5 dB, P=0.035; medulla, -22.8±5.2 to -18.7±3.7 dB, P=0.045). TTP in the cortex decreased after treatment (10.8±3.5 to 7.6±3.1 s, P=0.032), but it was unchanged in the medulla (10.6±3.0 to 8.3±3.2 s, P=0.098). Conclusions: Renal congestion can be observed using CEUS in CHF patients.

Left ventricular noncompaction with intractable heart failure responsive to empagliflozin.

Despite several reports on the mechanism of the effect of empagliflozin, which has the potential for improved prognosis in heart failure, it is still not fully understood. We experienced a case of left ventricular noncompaction that caused fluid retention in a patient who showed resistance to existing diuretics. By using empagliflozin, we successfully treated this case of acute heart failure and observed stabilized symptoms with no renal dysfunction and deterioration of patient condition. Although the potential for improved prognosis with this drug in a high-risk group for cardiovascular events has been reported, based on EMPA-REG OUTCOME trial results, there are few reports on its effect of treatment and mechanism in treating acute heart failure. The effect of this drug in treating heart failure from the acute phase to the chronic phase can be expected. .

Assessment of renal perfusion impairment in a rat model of acute renal congestion using contrast-enhanced ultrasonography.

Renal congestion is caused by elevated central venous pressure (CVP), and decreases glomerular filtration in patients with congestive heart failure. Since real-time contrast-enhanced ultrasonography (CEUS) using microbubble-based contrast agents can visualize the perfused microvascular bed, we sought to evaluate the impairment of renal perfusion during acute renal congestion with CEUS. In Wister rats, CEUS of kidney was performed with the direct monitoring of CVP and intra-renal pressure (IRP). When CVP was elevated to 10 and 15 mmHg after the bolus injection of normal saline via the femoral vein, peak intensity (PI, dB) and time to PI (TTP) in the renal cortex and medulla were compared with control rats. There was a strong correlation between IRP and CVP (r = 0.95, p < 0.0001). In the congestion model, more time was required for enhancement of the parenchyma, especially in the medulla compared to control; TTP of the medulla and cortex at 15 mmHg CVP (CVP15) was significantly prolonged compared with controls (medulla, 4351 ± 98 vs. 1415 ± 267 ms, p = 0.003; cortex, 3219 ± 106 vs. 1335 ± 264 ms, p = 0.005). In addition, medullary PI at CVP15 decreased, but not significantly, compared to those of controls and at 10 mmHg CVP (20.1 ± 0.9, 22.8 ± 1.6, 21.6 ± 0.2 dB). In contrast, cortical PIs at CVP15 were significantly lower than that of control (24.6 ± 1.0 vs. 31.4 ± 1.0 dB, p = 0.007). CEUS revealed that impaired renal parenchymal flow in an acute congestion model is accompanied with increased renal interstitial pressure.

Impact of statins on modulation by insulin of expression of plasminogen activator inhibitor type-1.

OBJECTIVE: Plasminogen activator inhibitor type-1 (PAI-1) is a physiologic inhibitor of fibrinolysis and a known determinant of cardiovascular risk. That its expression is stimulated by insulin in HepG2 human hepatoma cells has been shown earlier. Others have found that increased expression of PAI-1 is a risk factor for acute myocardial infarction. Pleiotropic (noncholesterol lowering) effects of statins seem to reduce cardiovascular risk. This study was designed to determine whether insulin stimulation of PAI-1 expression is attenuated by statins, and if so to explore mechanisms that are responsible for the attenuation. METHODS: PAI-1 protein in the conditioned media was assayed by western blotting, and PAI-1 mRNA expression was measured by real-time reverse transcriptase polymerase chain reactions. RESULTS: Insulin (0.001-10 micromol/l) increased accumulation of PAI-1 protein in the conditioned media and PAI-1 mRNA expression in HepG2 cells. A transient transfection assay of the human PAI-1 promoter-luciferase construct demonstrated that insulin increased PAI-1 promoter activity. Increased PAI-1 mRNA was attenuated significantly by U0126 and PD98059, specific inhibitors of mitogen-activated protein kinase. In contrast, GF109203X, an inhibitor of the protein kinase C pathway, and LY294002, an inhibitor of phosphatidylinositol 3-kinase, exerted no effects. Simvastatin (10 micromol/l), known to translocate membrane-bound sterol regulatory element-binding protein to nuclei, attenuated PAI-1 mRNA expression induced by insulin. It did not affect baseline PAI-1 mRNA expression. Intraperitoneal injection of insulin (0.1 IU/kg) increased concentrations of PAI-1 antigen in plasma in mice within 3 h, correlating with hepatic PAI-1 mRNA expression. CONCLUSION: Insulin-mediated augmented expression of PAI-1 may be amenable to suppression attributable to pleiotropic effects of statins, potentially diminishing cardiovascular risk in patients with insulin resistance.

Platelet aggregability in patients with hypertension treated with angiotensin II type 1 receptor blockers.

AIM: Cardiovascular events associated with hypertension often involve thrombosis. Increased platelet activity is one of the risk factors of cardiovascular diseases. Antithrombotic properties of antihypertensive agents are not fully characterized. Angiotensin II type 1 receptor blockers (ARBs) are widely used for the treatment of hypertension. Some ARBs can provoke antiaggregatory effects on platelets in vitro. Whether ARBs can inhibit platelet aggregation was tested in hypertensive patients in vivo. METHODS: Platelet aggregation was assessed by the highly sensitive particle counting method using laser-light scattering. RESULTS: Large platelet aggregation induced by adenosine diphosphate (ADP, 3 microM) was 2.6+/-0.4 (x10(7)) (SE) in hypertensive patients treated with losartan (72+/-3 years old, n=10) while it was 3.9+/-0.6 in hypertensive patients treated with candesartan (70+/-5 years old, n=6; p=0.056). Large platelet aggregation induced by thromboxane A2 receptor agonist, U46619 (10 microM), was 2.8+/-0.5 (x10(7)) in hypertensive patients treated with losartan while it was 5.1+/-0.9 in hypertensive patients treated with candesartan (p=0.033). Clinical characteristics including the control of blood pressure did not differ between the two groups (losartan 136+/-5/73+/-3 mmHg vs. candesartan 135+/-4/76+/-5). CONCLUSION: Thus, losartan may have the possibility to inhibit platelet activation in patients with hypertension independent of blood pressure reduction. Antiaggregatory properties may be independent of angiotensin II type 1 receptor or of antihypertensive actions. The favorable effects of losartan on reduction of adverse cardiovascular events among hypertensive patients may be at least partly mediated by inhibition of platelet activation.

Impact of a bidirectional approach via radial and popliteal arteries for the treatment of chronic total occlusion of lower limb artery: A case report.

A 49-year-old man with poorly controlled diabetes was admitted to Kushiro Rosai Hospital, Hokkaido, Japan after scalding both feet with boiling water. Because of poor healing, he was assessed for peripheral arterial disease. Angiography revealed total occlusion of the right common and external iliac arteries, diffuse stenosis of the right superficial femoral artery, focal stenosis of the left common iliac artery and chronic total occlusion of the left superficial femoral artery. A staged procedure with bidirectional approach via the radial and popliteal arteries was attempted. During the procedures, the patient was in the prone position on the catheterization table, and bidirectional guidewire manipulation was performed. All of the lesions were successfully stented. The patient was not required to change positions during the procedure, which can be performed by a single operator. The bidirectional approach is effective in the setting of transcatheter treatment of chronic total occlusive disease.

IL-1 and IL-6 induce hepatocyte plasminogen activator inhibitor-1 expression through independent signaling pathways converging on C/EBPdelta.

To elucidate signaling pathways activated by IL-1 and IL-6 that contribute to increased expression of plasminogen activator inhibitor-1 (PAI-1), we studied human hepatoma (HepG2) cells and primary mouse hepatocytes. HepG2 cell PAI-1 mRNA increased in response to IL-1beta, IL-6, and IL-1beta plus IL-6 as shown by real-time PCR. Activity of the transiently transfected PAI-1 promoter (-829 to +36 bp) increased as well. Systematic promoter deletion assays showed that the region from -239 to -210 bp containing a putative CCAAT-enhancer binding protein (C/EBP) binding site was critical. Point mutations in this region abolished the IL-1beta and IL-6 responses. Antibody interference electrophoretic mobility shift assays showed that C/EBPdelta (but not C/EBPalpha or C/EBPbeta) binding and protein were increased by IL-1beta, IL-6, and IL-1beta plus IL-6 in HepG2 cells. IL-1beta and IL-6 increased expression of both PAI-1 mRNA and C/EBPdelta mRNA in mouse primary hepatocytes as well. Downregulation of C/EBPdelta induced with small interfering RNA (siRNA) decreased secretion of PAI-1. As judged from results obtained with inhibitors, signal transduction in all three of the mitogen-activated protein kinase pathways was involved in IL-1-inducible PAI-1 expression. By contrast, JAK signaling was responsible for the IL-6-induced inducible expression. Thus IL-1 and IL-6 exert directionally similar effects on PAI-1 expression, but the induction involves distinct signaling pathways with a final common mediator, C/EBPdelta.

Hepatocyte growth factor regulates E box-dependent plasminogen activator inhibitor type 1 gene expression in HepG2 liver cells.

OBJECTIVE: We sought to determine the etiologic mechanism of pleiotropic growth factor, hepatocyte growth factor (HGF), as a regulator of hepatic synthesis of plasminogen activator inhibitor (PAI)-1, the physiological inhibitor of fibrinolysis and a potential inducer of atherothrombosis. METHODS AND RESULTS: HGF increased PAI-1 mRNA expression and PAI-1 protein accumulation in the conditioned media of human liver-derived HepG2 cells, and increased hepatic PAI-1 mRNA expression in vivo in mice. HGF-inducible PAI-1 mRNA was attenuated by U0126, a specific inhibitor of mitogen-activated protein kinase (MAPK) kinase, and genistein, an inhibitor of tyrosine kinase. HGF increased the human PAI-1 promoter (-829 to +36 bp) activity, and deletion and mutation analysis uncovered a functional E box (5'-CACATG-3') at positions -158 to -153 bp. Electrophoretic mobility shift assays demonstrated that this E box binds upstream stimulatory factors (USFs). HGF phosphorylated USFs through MAPK and tyrosine kinase pathways. Co-transfection of USF1 expression vector increased PAI-1 promoter activity. Sterol regulatory element-binding protein-1 attenuated HGF-inducible PAI-1 promoter activity. CONCLUSIONS: Because USFs are involved in the regulation of carbohydrates and lipid metabolism, HGF-mediated PAI-1 production may provide a novel link between atherothrombosis and metabolic derangements. Targeting HGF signaling pathway may modulate the thrombotic risk in high-risk patients.

Increased plasma concentrations of N-terminal pro-brain natriuretic peptide reflect the presence of mildly reduced left ventricular diastolic function in hypertension.

BACKGROUND: The potential use of assays of N-terminal pro-brain natriuretic peptide for detection of diastolic abnormalities associated with alterations in blood pressure has not been elucidated. This study was designed to determine whether increased plasma concentrations of N-terminal pro-brain natriuretic peptide sensitively reflect abnormal diastolic function associated with hypertension. METHODS: Concentrations of N-terminal pro-brain natriuretic peptide in plasma were assayed in 40 previously untreated hypertensive patients without overt congestive heart failure and in 20 age and sex-matched controls. Hypertensive patients were studied with the use of pulsed Doppler and color M-mode Doppler echocardiography for the evaluation of left ventricular diastolic function. RESULTS: Concentrations of N-terminal pro-brain natriuretic peptide were elevated in hypertensive patients [75.1+/-75.2 (SD) pg/ml compared with 37.9+/-38.5 in controls, P<0.05]. In hypertensive patients, concentrations of N-terminal pro-brain natriuretic peptide were negatively correlated with the ratio of color M-mode flow propagation velocity to transmitral E velocity consistent with the view that increased concentrations of N-terminal pro-brain natriuretic peptide are indicative of alterations in diastolic function. Hypertensive patients with N-terminal pro-brain natriuretic peptide values above the mean value in the control group exhibited significantly increased brachial intimal-medial thickness and reduced wall stress, consistent with the view that increased N-terminal pro-brain natriuretic peptide was associated with favorable peripheral arterial remodeling. CONCLUSIONS: Elevated concentrations of N-terminal pro-brain natriuretic peptide in plasma reflect the presence of left ventricular diastolic abnormalities and peripheral arterial remodeling in asymptomatic patients with hypertension.

Interleukin-6 and mevastatin regulate plasminogen activator inhibitor-1 through CCAAT/enhancer-binding protein-delta.

OBJECTIVE: We sought to determine the etiologic mechanism of proinflammatory cytokine, interleukin-6 (IL-6), and statin as regulators of synthesis of plasminogen activator inhibitor-1 (PAI-1), the physiological fibrinolysis inhibitor and an acute-phase reactant. METHODS AND RESULTS: Transient transfection and luciferase assay in HepG2 human hepatoma-derived cells demonstrated that IL-6 increased PAI-1 promoter activity and mevastatin decreased IL-6-inducible response. Systematic deletion assay of the promoter demonstrated that the region (-239 to -210 bp) containing a putative CCAAT/enhancer-binding protein (C/EBP) binding site was necessary. Point mutation in this site abolished the IL-6-inducible response. Electrophoretic mobility shift assay and chromatin immunoprecipitation assay demonstrated that C/EBPalpha, C/EBPbeta, and C/EBPdelta were involved in protein-DNA complex formation in intact cells. Deoxyribonuclease (DNase) I footprinting analysis revealed that 5' flanking region (-232 to -210 bp) is acute-phase response protein-binding site. C/EBPdelta binding activity was increased by IL-6 and attenuated by mevastatin. Mevastatin attenuated IL-6-mediated increase of C/EBPdelta protein in the nuclear extracts. IL-6 also increased PAI-1 and C/EBPdelta mRNA in mouse primary hepatocytes. CONCLUSIONS: IL-6 increases hepatic PAI-1 expression mediated by the -232- to -210-bp region of the promoter containing a C/EBPdelta binding site. Vascular protection by statins may be partly mediated through regulation of CEBPdelta and consequent modulation of PAI-1 expression.

Salutary effects of attenuation of angiotensin II on coronary perivascular fibrosis associated with insulin resistance and obesity.

Obesity and insulin resistance confer increased risk for accelerated coronary disease and cardiomyopathic phenomena. We have previously shown that inhibition of angiotensin-converting enzyme (ACE) prevents coronary perimicrovascular fibrosis in genetically obese mice that develop insulin resistance. This study was performed to elucidate mechanism(s) implicated and to determine the effects of attenuation of angiotensin II (Ang) II. Genetically obese ob/ob mice were given ACE inhibitor (temocapril) or Ang II type 1 (AT(1)) receptor blocker (olmesartan) from 10 to 20 weeks. Cardiac expressions of plasminogen activator inhibitor (PAI)-1, the major physiologic inhibitor of fibrinolysis, and transforming growth factor (TGF)-beta(1), a prototypic profibrotic molecule, were determined and extent of perivascular coronary fibrosis was measured. Twenty-week-old obese mice exhibited increased plasma levels of PAI-1 and TGF-beta(1) compared with the values in lean counterpart. Perivascular coronary fibrosis in arterioles and small arteries was evident in obese mice that also showed increased left ventricular collagen as measured by hydroxyproline assay. Immunohistochemistry confirmed the deposition of perivascular type 1 collagen. Markedly increased PAI-1 and TGF-beta were seen immunohistochemically in coronary vascular wall and confirmed by western blotting. When obese mice were treated with temocapril or olmesartan from 10 to 20 weeks, both were equally effective and prevented increases in perivascular fibrosis, plasma PAI-1 and TGF-beta(1), left ventricular collagen and mural immunoreactivity for PAI-1, TGF-beta and collagen type 1. The c-Jun NH(2)-terminal kinase (JNK) activity was elevated in the left ventricle of obese mice (western) and blocked by temocapril and olmesartan. Ang II-mediated upregulation of PAI-1 and TGF-beta(1) with collagen deposition may explain the mechanism of perivascular fibrosis in obese mice. ACE inhibition and blockade of AT(1) receptor may prevent coronary perivascular fibrosis and collagen deposition even before development of overt diabetes. JNK activation may be a mediator of obesity-related cardiac dysfunction and a potential therapeutic target.

Increased expression of plasminogen activator inhibitor-1 by mediators of the acute phase response: a potential progenitor of vasculopathy in hypertensives.

Hypertension is an important risk factor for coronary atherosclerosis, which is accelerated by inflammation and diminished fibrinolysis. We have previously shown that levels of plasminogen activator inhibitor-1 (PAI-1), the major physiologic inhibitor of fibrinolysis, are increased with atherogenic metabolic derangement. Because the liver is one of the major sources of circulating PAI-1, we here examined the effects of two proinflammatory cytokines, interleukin (IL)-1beta, and IL-6, on PAI-1 production in a human hepatoma cell line, HepG2. IL-1beta (1 ng/ml) and IL-6 (1 ng/ml) increased the accumulation of PAI-1 in the conditioned media over 24 h (IL-1beta: 2.1 +/- 0.2 (mean +/- SD) fold over the control; IL-6:1.4 +/- 0.2 fold; Western blot, p < 0.05). The increase in PAI-1 protein accumulation correlated with the increased expression of PAI-1 mRNA (Northern blot). An HMG-CoA reductase inhibitor (mevastatin, 10 micromol/l) attenuated the PAI-1 production induced by IL-1beta and IL-6. The plasma PAI-1 activity level was higher in hypertensives than in normotensives (10.0 +/- 9.8 AU/ml vs. 6.2 +/- 4.5 AU/ml, p < 0.05). The plasma PAI-1 antigen level was also higher in hypertensives than in normotensives (30.9 +/- 22.4 ng/ml vs. 24.4 +/- 13.3 ng/ml, p < 0.05). Thus, 1) IL-1beta and IL-6 can increase PAI-1 production in hepatic cells and 2) mevastatin may exert anti-thrombotic effects by decreasing the PAI-1 protein production induced by these proinflammatory cytokines. These results provide further insights into how inflammation is involved in the atherothrombotic complications observed in hypertensives, which may be ameliorated by HMG-CoA reductase inhibitors.

Coronary capillary network remodeling and hypofibrinolysis in aged obese diabetic rats: implications for increased myocardial vulnerability to ischemia.

Despite the known abnormalities of cardiac function in patients with overt non-insulin dependent diabetes mellitus (NIDDM) the temporal changes of coronary capillary network remodeling leading to potential microcirculatory dysfunction have not been elucidated. To this end, left ventricular subendocardial capillary network of Otsuka Long-Evans Tokushima Fatty (OLETF) rats, characterized by hypertension, obesity, hyperglycemia, hyperinsulinemia and mild NIDDM, and control Long-Evans Tokushima (LETO) rats were investigated. Total capillary density in OLETF was significantly higher than that in LETO at 20 weeks, suggesting compensatory improvement of O2 transport at early stages of NIDDM. The increase in capillary density in OLETF was lost at 40 and 60 weeks due to the decreases of intermediate capillary portions and venular capillary portions. Although capillary domain area (area innervated by single capillary) in OLETF was lower than that in LETO at 20 weeks, the values were similar between OLETF and LETO at 40 and 60 weeks, suggesting that adaptive improvement in the capacity for 02 transport with a high perfusion was lost in late stages of NIDDM. Activity of plasma plasminogen activator inhibitor-1 (PAI-1), the major physiologic inhibitor of proteo(fibrino)lysis, in OLETF was higher than that in LETO at 40 and 60 weeks, suggesting that increase of PAI-1 may downregulate compensatory adaptive capillary network remodeling by inhibiting proteolysis and angiogenesis in the cardiac interstitium. Loss of adaptive myocardial microcirculation may therefore contribute to increased vulnerability in ischemic injury and to cardiac dysfunction in NIDDM.

Intracellular signal transduction modulating expression of plasminogen activator inhibitor-1 in adipocytes.

The concentrations in blood of plasminogen activator inhibitor-1 (PAI-1), an inhibitor of fibrinolysis and proteolysis, are elevated in obese and insulin-resistant subjects, predispose them to the risk of thrombosis, and may accelerate atherogenesis. Adipose tissue is a prominent source. Accordingly, intracellular signaling pathways that may influence PAI-1 expression in adipocytes have been the focus of considerable study. Rho, a small GTP binding and GTPase protein, when activated in turn activates its target, Rho-associated coiled-coil forming protein, to yield an active kinase, Rho-kinase, an effector in the Rho pathway. Rho-kinase exerts calcium-sensitizing effects in vascular smooth muscle cells and inhibitory effects on transforming growth factor-beta (TGF-beta) expression in chicken embryonic heart cells. Because TGF-beta is a powerful agonist of PAI-1 expression, we characterized the effects of inhibition of Rho-kinase in 3T3-L1 adipocytes. PAI-1 mRNA was determined by Northern blotting, and PAI-1 protein was determined by Western blotting. The Rho-kinase inhibitor, Y-27632 [(R)-(+)-trans-N-(4-pyridyl)-4-(1-aminoethyl)-cyclohexanecarboxamide], increased PAI-1 expression markedly. Although genistein, a flavonoid tyrosine kinase, attenuated the increase of PAI-1 induced by Y-27632, other non-flavonoid tyrosine kinase inhibitors did not. However, another flavonoid, daidzein, which lacks tyrosine kinase activity, decreased basal PAI-1 expression and attenuated the induction of PAI-1 expression by Y-27632. Thus, the Rho/Rho-kinase system inhibits PAI-1 expression by a flavonoid-sensitive mechanism in adipocytes. Therefore, flavonoids may be useful in decreasing elevated PAI-1 expression in adipose tissue and its consequent pathophysiologic sequelae.