This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Sobel, B. E. Articles by Gold, H. Search for Related Content PubMed PubMed Citation Articles by Sobel, B. E. Articles by Gold, H.

(Circulation. 1998;97:2213-2221.)
© 1998 American Heart Association, Inc.

Clinical Investigation and Reports

Increased Plasminogen Activator Inhibitor Type 1 in Coronary Artery Atherectomy Specimens From Type 2 Diabetic Compared With Nondiabetic Patients

A Potential Factor Predisposing to Thrombosis and Its Persistence

Burton E. Sobel, MD; Janet Woodcock-Mitchell, PhD; David J. Schneider, MD; Robert E. Holt, BA; Kousuke Marutsuka, MD; ; Herman Gold, MD

From the Department of Medicine, The University of Vermont College of Medicine, Burlington (B.E.S., J.W.-M., D.J.S., K.M.); and Massachusetts General Hospital, Boston (R.E.H., H.G.).

Correspondence to Dr Burton E. Sobel, Department of Medicine, FAHC-MCHV Campus, Fletcher 311, 111 Colchester Ave, Burlington, VT 05401. E-mail burton.sobel{at}vtmednet.org

	Abstract

Top Abstract Introduction Methods Results Discussion References

 
Background—Inhibition of fibrinolysis attributable to elevated concentrations of plasminogen activator inhibitor type 1 (PAI-1) in blood is associated with insulin resistance, hyperinsulinemia, and type 2 diabetes mellitus. Because we have shown that insulin can stimulate PAI-1 synthesis in vivo and because accelerated vascular disease is common in such patients as well, we hypothesized that increased PAI-1, potentially predisposing to thrombosis, acute occlusion, and accelerating atherosclerosis because of thrombus-associated mitogens, would be present in excess in atheroma from type 2 diabetic subjects.

Methods and Results—Samples acquired by directional coronary atherectomy from 25 patients with type 2 diabetes and 18 patients without diabetes were characterized qualitatively histologically for cellularity and by immunohistochemistry visually and qualitatively and by quantitative image analysis for assessment of urokinase-type plasminogen activator (u-PA) and PAI-1. Patients with and without diabetes were similar with respect to demographic features and the distribution and severity of coronary artery disease. Substantially more PAI-1 and substantially less u-PA were present in the atherectomy samples from subjects with diabetes.

Conclusions—The disproportionate elevation of PAI-1 compared with u-PA observed in atheromatous material extracted from vessels of diabetic subjects is consistent with increased gene expression of PAI-1 in vessels as well as the known increase of PAI-1 in blood, presumably reflecting increased synthesis. The increased PAI-1 detected in the atheroma may contribute in vivo to accelerated or persistent thrombosis underlying acute occlusion and to vasculopathy exacerbated by clot-associated mitogens in the vessel wall. Because the changes were observed to be associated with insulin resistance and type 2 diabetes mellitus, they may be modifiable by reduction of insulin resistance with insulin sensitizers and stringent control of hyperglycemia.

Key Words: diabetes mellitus • coronary disease • fibrinolysis • insulin • thrombosis

	Introduction

Top Abstract Introduction Methods Results Discussion References

 
The prevalence of coronary artery disease in type 2 diabetic subjects is 4-fold greater than that in nondiabetic subjects.¹ Even with stringent control, an increased risk for macrovascular disease in type 2 diabetes persists. Accordingly, the possibility exists that the combined hyperproinsulinemia and hyperinsulinemia typical of type 2 diabetes may exert adverse influences on the vessel wall independent of hyperglycemia and other derangements of intermediary metabolism typically present in both type 1 (insulinopenic) and type 2 (hyperinsulinemic and dysinsulinemic) diabetes.^{2 3 4 5}

We and others^{6 7 8} have observed consistent elevations of concentrations in blood of PAI-1 reflected by reduced fibrinolysis in response to venous occlusion, a phenomenon consistent with intermittent persistence of microthrombi in vessels with consequent adverse effects of clot-associated mitogens on the vessel wall accelerating macrovascular disease.

Subjects with type 2 diabetes who undergo percutaneous transluminal coronary angioplasty exhibit 4-fold higher 5-year mortality than do nondiabetic subjects treated comparably and with similar lesions.^{9 10} The increase appears to be attributable largely to restenosis. As judged from analysis of human and porcine vessels, early atherosclerotic lesions and complex plaques are characterized by disproportionate increases in PAI-1 within the vessel wall compared with concentrations of u-PA and t-PA.¹¹ Furthermore, rats genetically predisposed to insulin resistance, postprandial hyperglycemia, and macroangiopathy late in life exhibit changes in the walls of vessels analogous to those seen in type 2 diabetic human subjects.¹² Explants of vascular smooth muscle cells from vessels of the animals predisposed to atherosclerosis exhibit higher rates of proliferation in vitro than do cells from controls, even when the explants have been obtained many months before the time of appearance, in vivo, of macroangiopathy.¹³

These observations led us to hypothesize that one of the factors contributing to macroangiopathy in type 2 diabetes and to the accelerated restenosis compromising the long-term efficacy of angioplasty in diabetic subjects is a disproportionate elevation of PAI-1 in vascular wall components and atheroma. Such an elevation would be likely to predispose to thrombosis and its persistence, thereby increasing the risk of acute coronary events and possibly restenosis potentiated by clot-associated mitogens.

	Methods

Top Abstract Introduction Methods Results Discussion References

 
Patients Studied
Twenty-five patients with type 2 diabetes and 18 without clinical evidence of diabetes were studied between April 1996 and March 1997 at the time of DCA mandated by clinical indications (performed by H.G. at the Massachusetts General Hospital). The two groups of patients (diabetic and nondiabetic) were similar with respect to clinical indications for DCA, use of heparin during all procedures, absence of gross thrombus detected angiographically, initial success of the procedure, and other characteristics, including age and sex (Tables 1 and 2) and the nature (primary or restenotic) and distribution of culprit coronary arterial lesions (Table 3).

View this table: [in this window] [in a new window]   Table 1. Biochemical Variables in Specific Categories of Patients

View this table: [in this window] [in a new window]   Table 2. Patient Characteristics

View this table: [in this window] [in a new window]   Table 3. Characteristics of Coronary Disease

Coronary atherectomy samples were excised selectively and retrieved from coronary atherosclerotic lesions by conventionally performed DCA.

Medications
Each patient was pretreated with aspirin 325 mg/d and dipyridamole 50 mg every 6 hours initiated 24 hours before DCA and continued after hospital discharge. Heparin was administered as an initial bolus of 10 000 U IV after insertion of an arterial sheath and as additional 2500-U boluses every 30 minutes as needed to maintain the activated clotting time between 250 and 300 seconds throughout the DCA procedure.

DCA was successful in each case. There was no associated mortality. The extent of residual stenosis was reduced to <50% of the initial stenosis universally.

Characterization of Atherectomy Specimens
Atherectomy samples were assayed for u-PA and PAI-1 by immunohistochemistry (immunoperoxidase staining).¹⁴ In addition, the material was assayed for cellularity. Analysis was performed as follows.

Qualitative Assessments
A visual grading scale (+ to ++++) was used for the assessment of the intensity of immunohistochemical staining as shown in Figures 1 and 2. An analogous grading scale (+ to ++++) was used for assessment of cellularity as shown in Figure 3. Sections from the DCA-extracted material were characterized by comparison of the sections with the grading scale sections by two observers who were blinded to the characteristics of the patients. Each observer evaluated a minimum of three sections per block (selected randomly and independently), evaluated three to five fields per section (again selected randomly and independently), and scored each field on a 0 to 4+ scale for intensity and a 0 to 4+ scale for the extent of distribution of positive staining to yield an average result for each atherectomy sample. Results were obtained by averaging the average values from each observer for each sample.

View larger version (111K): [in this window] [in a new window]   Figure 1. Immunohistochemical staining of PAI-1 identifying scale used to grade samples. Each sample was scored in relation to reference scale shown here by two observers blinded to status of patients from whom samples were obtained. In each case in this and subsequent figures, negative controls were obtained with normal murine IgG substituted for primary antibody as shown in Figure 4. Magnification x100.

View larger version (132K): [in this window] [in a new window]   Figure 2. Immunohistochemical staining of u-PA defining scale used to grade samples applied in a fashion analogous to that for PAI-1, as noted in legend to Figure 1. In each case in this and subsequent figures, negative controls were obtained with normal murine IgG substituted for primary antibody as shown in Figure 4. Magnification x100.

View larger version (131K): [in this window] [in a new window]   Figure 3. Grading scale used to score each sample with respect to cellularity and applied in a fashion analogous to that used with grading scales noted in legends to Figures 1 and 2. Sections were stained with hematoxylin, which stains nuclei blue. Arrows point to regions with cellularity of increasing extent in A through D. Magnification x100. Note: These samples were also stained for PAI-1.

Quantitative Assessments
Quantitative image analysis of the sections was performed by observers blinded with respect to the patients from whom samples were obtained, as follows:¹⁵ immunoperoxidase-stained slides were viewed with an Olympus BX-50 upright light microscope. Digital gray-scale images were acquired with an attached Sony DXC-960MD/LLP charged coupled device camera connected via an RS-170 cable to a frame grabber board in a Sun SPARCstation 5 computer. Image collection and analysis was performed with IMIX/IMAGIST Version 8 software (Princeton Gamma Tech). Data for all images of each type were collected with identical camera settings, followed by selection of regions of interest on the digitized image. Gray-scale values (pixel intensities) within the regions of interest were plotted as histograms, and minimum, maximum, and mean pixel intensity values were calculated with conventional software. These values were used to compare intensity of immunoperoxidase reaction products in vessels from diabetic and nondiabetic subjects. Data are expressed as intensity units above values with mouse IgG used as a control for comparison. To verify the representative nature of computed values used for comparisons between groups, coefficients of variation were evaluated for repeated readings of the same field, values from multiple fields within the same section, and multiple sections within a block from a given sample (6 to 10 values for each). Results were 0.26%, 2.3%, and 3.6%. The low values of these coefficients of variation are consistent with the validity of between-group comparisons of values obtained within each group.

Preparation of Specimens for Analysis
The DCA samples were fixed in ethanol for a minimum of 48 hours and processed conventionally for histochemical analysis. Sections 6 µm thick were prepared and stained with antibodies specific for each protein of interest as described below. Three sections from each tissue sample were assayed for each component, and results were averaged to obtain a score for each variable in each DCA sample.

Immunoperoxidase Staining
Immunoperoxidase staining with the antibodies selected was performed as follows. Tissue sections were deparaffinized through two incubations in xylene, 5 minutes each, followed by successive incubations in ethanol (100%, 95%, 75%, and 50%) for 3 minutes each and subsequently in PBS for 3 minutes. All incubations were performed at room temperature. Sections were treated with 0.25% trypsin for 15 minutes at ambient temperature, followed by two washes in PBS. They were then placed in 0.75% H₂O₂/75% methanol for 30 minutes, washed twice in PBS, and maintained in a humidified chamber in 3% BSA in PBS for 30 minutes at room temperature. Subsequently, they were treated with 10% normal goat serum for 30 minutes, followed by exposure to primary antibody in a humidified chamber at 37°C for 30 minutes.

The primary antibodies used were monoclonal antihuman PAI-1 (product No. 3785) (10 µg/mL); monoclonal antihuman u-PA (product No. 3689) (10 µg/mL) (both acquired from American Diagnostica); monoclonal anti–smooth muscle -actin (from Sigma Chemical Co) as a positive control; anti-CD44 (acquired from R+D Systems); and normal mouse IgG (from Sigma Chemical Co) as a negative control. The anti–human PAI-1 antibody recognizes both free PAI-1 and PAI-1 complexed to plasminogen activators. The anti–human u-PA antibody recognizes free u-PA and receptor-bound u-PA. It also recognizes u-PA complexed with PAI-1 as verified in our laboratory and shown in Western blots.

After incubation at 37°C, sections were washed three times in PBS and treated with secondary antibody (DAKO Envision System, a horseradish peroxidase polymer system conjugated with secondary antibodies) that reacted with mouse primary antibodies (DAKO). Again, the sections were incubated at 37°C for 30 minutes, washed three times in 0.05 mol/L Tris-hydroxyaminomethane (Tris), pH 7.6, and treated with a substrate solution consisting of 25 mg DAB (Sigma Chemical Co) and 17.5 µL 30% H₂O₂ in 50 mL Tris for 5 minutes at room temperature followed by three washes in PBS.

For conventional histology, counterstaining was performed with Mayer's hematoxylin solution (Sigma Chemical Co) for 3 minutes. The sections were then washed three times in PBS and dehydrated through 50%, 75%, 95%, and 100% ethanol. They were washed twice in xylene before being mounted under coverslips with Permount.

Grading of Immunohistochemical Staining Intensity and Cellularity
Grading scales are shown in Figures 1 through 3. The absence of staining for PAI-1 and/or u-PA in negative controls is shown in Figure 4. This figure also demonstrates the colocalization of PAI-1 with smooth muscle -actin–positive cells, indicating that the PAI-1 seen was present primarily in smooth muscle cells. Values in samples were based on the intensity of staining and the percentage of tissue stained, both referenced to the sections in the grading scale used to define the 4-point grading scale as judged independently by two observers evaluating independently and randomly identified fields (three to five per section) and blinded with respect to the characteristics of the patients from whom the sections had been obtained.

View larger version (119K): [in this window] [in a new window]   Figure 4. Concordant localization of immunostained PAI-1 and -actin indicative of vascular smooth muscle cells. Serial sections stained with PAI-1 antibody (A) and -actin antibody (B). PAI-1 was detected virtually exclusively in vascular smooth muscle cells characterized by presence of -actin. C and D show two negative controls illustrating lack of staining with normal mouse IgG used instead of primary antibody compared with results in A and B, respectively. As noted in text, other negative controls were obtained routinely to verify specificity of immunostaining with antibody against PAI-1, u-PA, or -actin.

Statistical Analysis
Comparisons between groups were performed with two-tailed Student's t tests for unpaired samples. Differences with values of P0.05 were considered to be significant.

	Results

Top Abstract Introduction Methods Results Discussion References

 
Patients with and without diabetes did not differ with respect to age (Table 1) or other demographic features (Table 2). The nature (primary or restenotic) and distribution of coronary lesions were generally similar in the two groups (Table 3). As shown in a representative example of a photomicrograph of immunostained material in Figure 5 and in Table 1, atherectomy samples from subjects with diabetes appeared to exhibit less u-PA than those from subjects without diabetes (1.28±0.16 [SE] arbitrary units compared with 2.62±0.26), P<0.01, a difference consistent with decreased atheroma-associated cell surface–mediated proteo(fibrino)lytic system capacity. By contrast, tissue from diabetic subjects appeared to exhibit significantly more PAI-1 (2.32±0.19) than tissue obtained from nondiabetic subjects (1.55±0.17, P<0.01), as shown in the example in Figure 6, and by results in Table 1. Results with automated image analysis were consistent with the qualitative differences observed visually (Table 1). Thus, as shown in Table 1 and Figure 7, samples from patients with diabetes exhibited consistently more PAI-1 and consistently less u-PA than samples from patients without diabetes. These differences were consistent in subsets of patients with primary and restenotic lesions (Table 1) and evident regardless of the nature of the treatment of diabetes (Table 3).

View larger version (130K): [in this window] [in a new window]   Figure 5. Intensity and distribution of immunohistochemical staining of u-PA in samples from representative patients without diabetes (A and B) compared with those in samples from patients with type 2 diabetes (C and D). Both distribution and intensity of staining were generally less in samples from subjects with diabetes (Table 1). In each case in this and subsequent figures, negative controls were obtained with normal murine IgG substituted for primary antibody as shown in Figure 4. Dark brown in A reflects intense staining with u-PA antibody in area rich in matrix. Intensities of staining in B and D are similar and are included in this figure to demonstrate that intensity of staining in a given section from a diabetic patient may closely resemble intensity of staining in another given section from a nondiabetic subject. However, in general, staining with u-PA antibody in sections from diabetic patients was less intense and less widely distributed than that in sections from nondiabetic subjects as shown in Table 1 and confirmed by quantitative image analysis results shown in Figure 7. Magnification x100.

View larger version (136K): [in this window] [in a new window]   Figure 6. Intensity of immunohistochemical staining for PAI-1 in representative samples from patients without diabetes (A and B) compared with those from representative patients with type 2 diabetes (C and D). Intensity and distribution of staining were generally greater in samples from subjects with diabetes than those without diabetes (Table 1). In each case in this and subsequent figures, negative controls were obtained with normal murine IgG substituted for primary antibody as shown in Figure 4. Magnification x100.

View larger version (28K): [in this window] [in a new window]   Figure 7. Results of quantitative image analysis (IA) for detection of u-PA and PAI-1 in nondiabetic vs diabetic subjects (A), nondiabetic vs all diabetic subjects and only diabetic subjects treated with insulin, sulfonylureas, or both (B), diabetic and nondiabetic subjects with primary lesions (C), and diabetic vs nondiabetic subjects with restenotic lesions (D). *P<0.05 for comparisons between diabetic and nondiabetic subjects in each case.

Cellularity scores assessed visually and hence qualitatively did not differ significantly for tissues from the two groups of patients (Table 1) (1.76±0.20 [SE] arbitrary units compared with 2.02±0.21 in nondiabetic subjects). These results are not inconsistent with proliferation of vascular smooth muscle cells within the arterial wall of the vessels from diabetic subjects in situ in view of the nature of the coronary atherectomy procedure used, which extracted material not necessarily representative of cellularity within the entire vessel wall but more likely to be indicative of overall cellularity in complex plaques.

	Discussion

Top Abstract Introduction Methods Results Discussion References

 
Results in the present study are consistent with the hypothesis that one of the contributors to the development of accelerated macroangiopathy in type 2 diabetes mellitus is altered tissue expression of components of the fibrinolytic system within atheroma and presumably therefore arterial walls; specifically, disproportionate elevations of concentrations of PAI-1 with respect to concentrations of u-PA. The results support the possibility that inhibition of the fibrinolytic system activity in situ in syndromes of insulin resistance and hyperinsulinemia, including type 2 diabetes, predisposes to thrombosis and its persistence, setting the stage for thrombotic coronary artery occlusion and accelerated atherosclerosis or restenosis in response to clot-associated mitogens. The present results demonstrate an increase in total PAI-1 (free plus plasminogen activator–complexed PAI-1) and a decrease in total u-PA (free and receptor bound) in the specimens from the diabetic patients. Thus, even if some of the PAI-1 detected is complexed with some of the u-PA (an interaction possible with the two-chain species), the amount of free PAI-1 appears to be increased. Accordingly, the results indicate that immunohistochemically detectable PAI-1 is increased and immunohistochemically detectable u-PA is decreased in atherectomy specimens acquired by extraction and conventional fixation from the diabetic compared with the nondiabetic subjects. Thus, they suggest that the hyper(pro)insulinemia associated with type 2 diabetes leads to elevated intramural PAI-1 that can contribute to an increased risk of thrombosis and accelerated vasculopathy.

Concentrations of PAI-1 in blood are elevated in association with diverse states of insulin resistance. A salient example is the genetically obese mouse (ob/ob) as reported initially by Samad and Loskutoff.¹⁴ The same laboratory demonstrated high concentrations of PAI-1 in murine adipose tissue in vivo and its augmentation in response to tumor necrosis factor-.¹⁵ Consistent with these observations, elevations of PAI-1 have been seen in human subjects with obesity, type 2 diabetes mellitus, and the polycystic ovary syndrome.^{6 16 17 18 19 20} We recently demonstrated that weight reduction induced by modest caloric restriction in elderly obese subjects leads to a decline in prevailing concentrations of PAI-1 in blood paralleled by augmentation of functional activity of the fibrinolytic system.²⁰ When we administered troglitazone, a thiazolidinedione known to enhance insulin sensitivity, to patients with the polycystic ovary syndrome in whom concentrations of PAI-1 in blood are markedly elevated, concentrations of PAI-1 in blood declined markedly.¹⁹ If such changes are paralleled by altered expression of PAI-1 within atheroma and/or vessel walls, as appears likely judged from the result in the present study, augmentation of insulin sensitivity may prove to be effective in ameliorating disproportionate elevation of vascular wall PAI-1 and its potential pathogenetic impact on thrombosis and the evolution of macroangiopathy.

The present results underscore the potential pathogenetic importance of derangements in expression of fibrinolytic system proteins in tissues as well as in blood. Insulin augments expression of PAI-1 in HepG2 cells (a human hepatoma cell line). Both insulin and its precursor, proinsulin, in concentrations consistent with those prevailing in blood in subjects with type 2 diabetes mellitus, augment elaboration of PAI-1 from these cells.⁸ Furthermore, insulin augments PAI-1 elaboration by endothelial cells in the presence of cocultured vascular smooth muscle cells, again in concentrations consistent with those seen in blood in subjects with type 2 diabetes.²¹ Administration of either insulin or proinsulin to experimental animals maintained under euglycemic conditions leads not only to augmented concentrations of PAI-1 in blood but also to augmented concentrations of PAI-1 protein and PAI-1 mRNA in vessel walls.²² Although administration of insulin to human subjects with type 2 diabetes has not been shown to elevate PAI-1 in blood, possibly because of the concomitant reduction in proinsulin secretion as noted by Jain et al,²³ we have recently found it to do so in human cells in a setting in which the metabolic milieu simulates that associated with type 2 diabetes.²⁴ Taken together with the present observations, these findings suggest that vascular wall PAI-1 synthesis is a potentially useful target for measures designed to reduce the acceleration of macroangiopathy typical of type 2 diabetes and to reduce the risk of thrombotic coronary occlusion underlying many acute coronary events.

Conclusions
The results obtained in this study are consistent with the hypothesis that a disproportionate elevation of PAI-1 not only in blood but also in extracted atheroma and presumably vessel walls is characteristic of and perhaps a direct consequence of hyperinsulinemia and hyperproinsulinemia typical of insulin-resistant states, including type 2 diabetes mellitus. Accordingly, reduction of insulin through diet and exercise programs, optimal control of hyperglycemia, and perhaps concomitant use of insulin sensitizers, such as thiazolidinediones, offers particular promise for attenuating progression of macrovascular disease exacerbated by thrombosis in insulin-resistant states, including type 2 diabetes mellitus.

	Selected Abbreviations and Acronyms

 

DCA = directional coronary atherectomy PAI-1 = plasminogen activator inhibitor type 1 t-PA = tissue plasminogen activator u-PA = urokinase plasminogen activator

	Acknowledgments

 
The assistance of Tomohiro Sakamoto, MD, Douglas J. Taatjes, PhD, and Satoshi Fujii, MD, of the Department of Medicine, The University of Vermont College of Medicine, Burlington, is appreciated.

	Footnotes

 
Presented at the 70th Scientific Sessions of the American Heart Association, Orlando, Fla, November 10–13, 1997, and published in abstract form (Circulation. 1997;96[suppl I]:I-591).

Received December 1, 1997; revision received January 22, 1998; accepted January 28, 1998.

	References

Top Abstract Introduction Methods Results Discussion References

 
1. Schneider DJ, Sobel BE. Determinants of coronary vascular disease in patients with type 2 diabetes mellitus and their therapeutic implications. Clin Cardiol. 1997;20:433–440.[Medline] [Order article via Infotrieve]

2. Kannel WB, D'Agostino RB, Wilson P, Belanger AJ, Gagnon DR. Diabetes, fibrinogen, and risk of cardiovascular disease: the Framingham experiments. Am Heart J. 1990;120:672–676.[Medline] [Order article via Infotrieve]

3. Swislocki ALM, Hoffman BB, Reaven GM. Insulin resistance, glucose intolerance and hyperinsulinemia in patients with hypertension. Am J Hypertens. 1989;2:419–423.[Medline] [Order article via Infotrieve]

4. DeFronzo RA. Insulin secretion, insulin resistance, and obesity. Int J Obes. 1982;6(suppl 1):73–82.

5. Despres J-P, Lamarche B, Mauglege P, Cantin B, Dagenais GR, Moorjani S, Lupien PJ. Hyperinsulinemia as an independent risk factor for ischemic heart disease. N Engl J Med. 1996;334:952–957.[Abstract/Free Full Text]

6. Vague P, Juhan-Vague I, Aillaud MF, Badier C, Viard R, Alessi MC, Collen D. Correlation between blood fibrinolytic activity, plasminogen activator inhibitor level, plasma insulin level and relative body weight in normal and obese subjects. Metabolism. 1986;35:250–253.[Medline] [Order article via Infotrieve]

7. McGill JB, Schneider DJ, Arfken CL, Lucore CL, Sobel BE. Factors responsible for impaired fibrinolysis in obese subjects and NIDDM patients. Diabetes. 1994;43:104–109.[Abstract]

8. Schneider DJ, Sobel BE. Augmentation of synthesis of plasminogen activator inhibitor type-1 by insulin and insulin-like growth factor type-1: implications for vascular disease in hyperinsulinemic states. Proc Natl Acad Sci U S A. 1991;88:9959–9963.[Abstract/Free Full Text]

9. Writing Group for the Bypass Angioplasty Revascularization Investigation (BARI) Investigators. Five-year clinical and functional outcome comparing bypass surgery and angioplasty in patients with multivessel coronary disease: a multicenter randomized trial. JAMA. 1997;277:715–721.[Abstract/Free Full Text]

10. Sobel BE. Potentiation of vasculopathy by insulin: implications from an NHLBI Clinical Alert. Circulation. 1996;93:1613–1615.[Free Full Text]

11. Schneider DJ, Ricci MA, Taatjes DJ, Baumann PQ, Reese JC, Leavitt BJ, Absher M, Sobel BE. Changes in arterial expression of fibrinolytic system proteins in atherogenesis. Arterioscler Thromb Vasc Biol. 1997;17:3294–3301.[Abstract/Free Full Text]

12. Schneider DJ, Absher PM, Russell JC, Sobel BE. Increased expression of plasminogen activator inhibitor type 1 (PAI-1) predisposes to atherosclerosis in corpulent, insulin resistant (JCR:LA-cp) rats that mimic derangements in type 2 diabetes. J Am Coll Cardiol. 1997;29:229A. Abstract.

13. Absher PM, Schneider DJ, Russell JC, Sobel BE. Increased proliferation of explanted vascular smooth muscle cells: a marker presaging atherogenesis. Atherosclerosis. 1997;131:187–194.[Medline] [Order article via Infotrieve]

14. Samad F, Loskutoff DJ. Tissue distribution and regulation of plasminogen activator inhibitor-1 in obese mice. Mol Med. 1996;2:568–582.[Medline] [Order article via Infotrieve]

15. Samad F, Yamamoto K, Loskutoff DJ. Distribution and regulation of plasminogen activator inhibitor-1 in murine adipose tissue in vivo: induction by tumor necrosis factor- and lipopolysaccharide. J Clin Invest. 1996;97:37–46.[Medline] [Order article via Infotrieve]

16. Taatjes DJ, Wadsworth M, Absher PM, Sobel BE, Schneider DJ. Immunoelectron microscopic localization of plasminogen activator inhibitor type 1 (PAI-1) in smooth muscle cells from morphologically normal and atherosclerotic human arteries. Ultrastruct Pathol. 1997;21:527–536.[Medline] [Order article via Infotrieve]

17. Sobel BE. Altered fibrinolysis and platelet function in the development of vascular complications of diabetes. Curr Opin Endocrinol Diabetes. 1996;3:355–360.

18. Jujan-Vague I, Roul C, Alessi MC, Ardissone JP, Heim M, Vague P. Increased plasminogen activator inhibitor activity in non-insulin-dependent diabetic patients: relationship with plasma insulin. Thromb Haemost. 1989;61:370–373.[Medline] [Order article via Infotrieve]

19. Ehrmann DA, Schneider DJ, Sobel BE, Cavaghan MK, Imperial J, Rosenfield RL, Polonsky KS. Troglitazone improves defects in insulin action, insulin secretion, ovarian steroidogenesis, and fibrinolysis in women with polycystic ovary syndrome. J Clin Endocrinol Metab. 1997;82:2108–2116.[Abstract/Free Full Text]

20. Calles-Escandon J, Ballor D, Harvey-Berino J, Ades P, Tracy R, Sobel BE. Amelioration of the inhibition of fibrinolysis in obese elderly subjects by moderate caloric restriction. Am J Clin Nutr. 1996;64:7–11.[Abstract/Free Full Text]

21. Nordt TK, Schneider, Sobel BE. Augmentation of the synthesis of plasminogen activator inhibitor type-1 by precursors of insulin: a potential risk factor for vascular disease. Circulation. 1994;89:321–330.[Abstract/Free Full Text]

22. Nordt TK, Sawa H, Fujii S, Sobel BE. Induction of plasminogen activator inhibitor type-1 (PAI-1) by proinsulin and insulin in vivo. Circulation. 1995;91:764–770.[Abstract/Free Full Text]

23. Jain SK, Nagi DK, Slavin BM, Lumb PJ, Yudkin JS. Insulin therapy in type 2 diabetic subjects suppresses plasminogen activator inhibitor (PAI-1) activity and proinsulin-like molecules independently of glycaemic control. Diabet Med. 1993;10:27–32.[Medline] [Order article via Infotrieve]

24. Schneider DJ, Sobel BE. Synergistic augmentation of expression of plasminogen activator inhibitor type-1 induced by insulin, very-low-density lipoproteins, and fatty acids. Coron Artery Dis. 1996;7:813–817.[Medline] [Order article via Infotrieve]

This article has been cited by other articles:

				H. Liu, A. E Dear, L. B Knudsen, and R. W Simpson A long-acting glucagon-like peptide-1 analogue attenuates induction of plasminogen activator inhibitor type-1 and vascular adhesion molecules J. Endocrinol., April 1, 2009; 201(1): 59 - 66. [Abstract] [Full Text] [PDF]

				F. Mouquet, F. Cuilleret, S. Susen, K. Sautiere, P. Marboeuf, P. V. Ennezat, E. McFadden, P. Pigny, F. Richard, B. Hennache, et al. Metabolic syndrome and collateral vessel formation in patients with documented occluded coronary arteries: association with hyperglycaemia, insulin-resistance, adiponectin and plasminogen activator inhibitor-1 Eur. Heart J., April 1, 2009; 30(7): 840 - 849. [Abstract] [Full Text] [PDF]

				J. F. Arenillas, J. Alvarez-Sabin, C. A. Molina, P. Chacon, I. Fernandez-Cadenas, M. Ribo, P. Delgado, M. Rubiera, A. Penalba, A. Rovira, et al. Progression of Symptomatic Intracranial Large Artery Atherosclerosis Is Associated With a Proinflammatory State and Impaired Fibrinolysis Stroke, May 1, 2008; 39(5): 1456 - 1463. [Abstract] [Full Text] [PDF]

				Y. Kanno, T. Into, C. J. Lowenstein, and K. Matsushita Nitric oxide regulates vascular calcification by interfering with TGF-{beta} signalling Cardiovasc Res, January 1, 2008; 77(1): 221 - 230. [Abstract] [Full Text] [PDF]

				G. Steiner Atherosclerosis in type 2 diabetes: a role for fibrate therapy? Diabetes and Vascular Disease Research, December 1, 2007; 4(4): 368 - 374. [Abstract] [PDF]

				R. L.C. Hoo, W.S. Chow, M.H. Yau, A. Xu, A. W.K. Tso, H.F. Tse, C. H.Y. Fong, S. Tam, L. Chan, and K. S.L. Lam Adiponectin Mediates the Suppressive Effect of Rosiglitazone on Plasminogen Activator Inhibitor-1 Production Arterioscler. Thromb. Vasc. Biol., December 1, 2007; 27(12): 2777 - 2782. [Abstract] [Full Text] [PDF]

				J. Wang, L. Yin, and M. A. Lazar The Orphan Nuclear Receptor Rev-erb{alpha} Regulates Circadian Expression of Plasminogen Activator Inhibitor Type 1 J. Biol. Chem., November 10, 2006; 281(45): 33842 - 33848. [Abstract] [Full Text] [PDF]

				M.-C. Alessi and I. Juhan-Vague PAI-1 and the Metabolic Syndrome: Links, Causes, and Consequences Arterioscler. Thromb. Vasc. Biol., October 1, 2006; 26(10): 2200 - 2207. [Abstract] [Full Text] [PDF]

				Y. Chen, R. C. Budd, R. J. Kelm Jr, B. E. Sobel, and D. J. Schneider Augmentation of Proliferation of Vascular Smooth Muscle Cells by Plasminogen Activator Inhibitor Type 1 Arterioscler. Thromb. Vasc. Biol., August 1, 2006; 26(8): 1777 - 1783. [Abstract] [Full Text] [PDF]

				M. E. Stegenga, S. N. van der Crabben, M. Levi, A. F. de Vos, M. W. Tanck, H. P. Sauerwein, and T. van der Poll Hyperglycemia Stimulates Coagulation, Whereas Hyperinsulinemia Impairs Fibrinolysis in Healthy Humans Diabetes, June 1, 2006; 55(6): 1807 - 1812. [Abstract] [Full Text] [PDF]

				P. Libby, D. M. Nathan, K. Abraham, J. D. Brunzell, J. E. Fradkin, S. M. Haffner, W. Hsueh, M. Rewers, B. T. Roberts, P. J. Savage, et al. Report of the National Heart, Lung, and Blood Institute-National Institute of Diabetes and Digestive and Kidney Diseases Working Group on Cardiovascular Complications of Type 1 Diabetes Mellitus Circulation, June 28, 2005; 111(25): 3489 - 3493. [Full Text] [PDF]

				D. Walcher and N. Marx Insulin resistance and cardiovascular disease: the role of PPAR{gamma} activators beyond their anti-diabetic action Diabetes and Vascular Disease Research, October 1, 2004; 1(2): 76 - 81. [Abstract] [PDF]

				D. J. Schneider, M. Hayes, M. Wadsworth, H. Taatjes, M. Rincon, D. J. Taatjes, and B. E. Sobel Attenuation of Neointimal Vascular Smooth Muscle Cellularity in Atheroma by Plasminogen Activator Inhibitor Type 1 (PAI-1) J. Histochem. Cytochem., August 1, 2004; 52(8): 1091 - 1099. [Abstract] [Full Text] [PDF]

				J. F. Arenillas, C. A. Molina, P. Chacon, A. Rovira, J. Montaner, P. Coscojuela, E. Sanchez, M. Quintana, and J. Alvarez-Sabin High lipoprotein (a), diabetes, and the extent of symptomatic intracranial atherosclerosis Neurology, July 13, 2004; 63(1): 27 - 32. [Abstract] [Full Text] [PDF]

				E. Barrett-Connor, E.-G. V. Giardina, A. K. Gitt, U. Gudat, H. O. Steinberg, and D. Tschoepe Women and Heart Disease: The Role of Diabetes and Hyperglycemia Arch Intern Med, May 10, 2004; 164(9): 934 - 942. [Abstract] [Full Text] [PDF]

				V. Fonseca, C. Desouza, S. Asnani, and I. Jialal Nontraditional Risk Factors for Cardiovascular Disease in Diabetes Endocr. Rev., February 1, 2004; 25(1): 153 - 175. [Abstract] [Full Text] [PDF]

				R. T. Hurst and R. W. Lee Increased Incidence of Coronary Atherosclerosis in Type 2 Diabetes Mellitus: Mechanisms and Management Ann Intern Med, November 18, 2003; 139(10): 824 - 834. [Abstract] [Full Text] [PDF]

				M. Nishimura, T. Hashimoto, H. Kobayashi, T. Fukuda, K. Okino, N. Yamamoto, N. Iwamoto, N. Nakamura, T. Yoshikawa, and T. Ono The high incidence of left atrial appendage thrombosis in patients on maintenance haemodialysis Nephrol. Dial. Transplant., November 1, 2003; 18(11): 2339 - 2347. [Abstract] [Full Text] [PDF]

				B. E. Sobel, D. J. Taatjes, and D. J. Schneider Intramural Plasminogen Activator Inhibitor Type-1 and Coronary Atherosclerosis Arterioscler. Thromb. Vasc. Biol., November 1, 2003; 23(11): 1979 - 1989. [Abstract] [Full Text] [PDF]

				S. S. Anand, Q. Yi, H. Gerstein, E. Lonn, R. Jacobs, V. Vuksan, K. Teo, B. Davis, P. Montague, and S. Yusuf Relationship of Metabolic Syndrome and Fibrinolytic Dysfunction to Cardiovascular Disease Circulation, July 29, 2003; 108(4): 420 - 425. [Abstract] [Full Text] [PDF]

				M. F. Carroll and D. S. Schade Timing of Antioxidant Vitamin Ingestion Alters Postprandial Proatherogenic Serum Markers Circulation, July 8, 2003; 108(1): 24 - 31. [Abstract] [Full Text] [PDF]

				K.-H. Mak and D. P. Faxon Clinical studies on coronary revascularization in patients with type 2 diabetes Eur. Heart J., June 2, 2003; 24(12): 1087 - 1103. [Abstract] [Full Text] [PDF]

				J. V. Tedesco, R. S. Wright, B. A. Williams, S. L. Kopecky, D. L. Dvorak, G. S. Reeder, W. L. Miller, and Mayo Coronary Care Unit Group Effect of Diabetes on the Mortality Risk of Cardiogenic Shock in a Community-Based Population Mayo Clin. Proc., May 1, 2003; 78(5): 561 - 566. [Abstract] [PDF]

				S. Devaraj, D. Y. Xu, and I. Jialal C-Reactive Protein Increases Plasminogen Activator Inhibitor-1 Expression and Activity in Human Aortic Endothelial Cells: Implications for the Metabolic Syndrome and Atherothrombosis Circulation, January 28, 2003; 107(3): 398 - 404. [Abstract] [Full Text] [PDF]

				S. Konstantinides, K. Schafer, and D. J. Loskutoff Do PAI-1 and Vitronectin Promote or Inhibit Neointima Formation?: The Exact Role of the Fibrinolytic System in Vascular Remodeling Remains Uncertain Arterioscler. Thromb. Vasc. Biol., December 1, 2002; 22(12): 1943 - 1945. [Full Text] [PDF]

				W. T. Cefalu, D. J. Schneider, H. E. Carlson, P. Migdal, L. Gan Lim, M. P. Izon, A. Kapoor, A. Bell-Farrow, J. G. Terry, and B. E. Sobel Effect of Combination Glipizide GITS/Metformin on Fibrinolytic and Metabolic Parameters in Poorly Controlled Type 2 Diabetic Subjects Diabetes Care, December 1, 2002; 25(12): 2123 - 2128. [Abstract] [Full Text] [PDF]

				A. I. Vulin and F. M. Stanley A Forkhead/Winged Helix-related Transcription Factor Mediates Insulin-increased Plasminogen Activator Inhibitor-1 Gene Transcription J. Biol. Chem., May 31, 2002; 277(23): 20169 - 20176. [Abstract] [Full Text] [PDF]

				R. H. Eckel, M. Wassef, A. Chait, B. Sobel, E. Barrett, G. King, M. Lopes-Virella, J. Reusch, N. Ruderman, G. Steiner, et al. Prevention Conference VI: Diabetes and Cardiovascular Disease: Writing Group II: Pathogenesis of Atherosclerosis in Diabetes Circulation, May 7, 2002; 105 (18): e138 - e143. [Full Text] [PDF]

				M. Tanasescu, F. B. Hu, W. C. Willett, M. J. Stampfer, and E. B. Rimm Alcohol consumption and risk of coronary heart disease among men with type 2 diabetes mellitus J. Am. Coll. Cardiol., December 1, 2001; 38(7): 1836 - 1842. [Abstract] [Full Text] [PDF]

				N. Mercado, E. Boersma, W. Wijns, B. J. Gersh, C. A. Morillo, V. de Valk, G.-A. van Es, D. E. Grobbee, and P. W. Serruys Clinical and quantitative coronary angiographic predictors of coronary restenosis: A comparative analysis from the balloon-to-stent era J. Am. Coll. Cardiol., September 1, 2001; 38(3): 645 - 652. [Abstract] [Full Text] [PDF]

				A. Pandolfi, D. Cetrullo, R. Polishuck, M. M. Alberta, A. Calafiore, G. Pellegrini, E. Vitacolonna, F. Capani, and A. Consoli Plasminogen Activator Inhibitor Type 1 Is Increased in the Arterial Wall of Type II Diabetic Subjects Arterioscler. Thromb. Vasc. Biol., August 1, 2001; 21(8): 1378 - 1382. [Abstract] [Full Text] [PDF]

				Y. Zhu, P. M. Farrehi, and W. P. Fay Plasminogen Activator Inhibitor Type 1 Enhances Neointima Formation After Oxidative Vascular Injury in Atherosclerosis-Prone Mice Circulation, June 26, 2001; 103(25): 3105 - 3110. [Abstract] [Full Text] [PDF]

				A. K. M. T. Zaman, S. Fujii, H. Sawa, D. Goto, N. Ishimori, K. Watano, T. Kaneko, T. Furumoto, T. Sugawara, I. Sakuma, et al. Angiotensin-Converting Enzyme Inhibition Attenuates Hypofibrinolysis and Reduces Cardiac Perivascular Fibrosis in Genetically Obese Diabetic Mice Circulation, June 26, 2001; 103(25): 3123 - 3128. [Abstract] [Full Text] [PDF]

				B. E. Sobel Acceleration of Restenosis by Diabetes : Pathogenetic Implications Circulation, March 6, 2001; 103(9): 1185 - 1187. [Full Text] [PDF]

				E. M. Redmond, J. P. Cullen, P. A. Cahill, J. V. Sitzmann, S. Stefansson, D. A. Lawrence, and S. S. Okada Endothelial Cells Inhibit Flow-Induced Smooth Muscle Cell Migration : Role of Plasminogen Activator Inhibitor-1 Circulation, January 30, 2001; 103(4): 597 - 603. [Abstract] [Full Text] [PDF]

				W. T. Cefalu Insulin Resistance: Cellular and Clinical Concepts Experimental Biology and Medicine, January 1, 2001; 226(1): 13 - 26. [Abstract] [Full Text]

				L. R. James, I. G. Fantus, H. Goldberg, H. Ly, and J. W. Scholey Overexpression of GFAT activates PAI-1 promoter in mesangial cells Am J Physiol Renal Physiol, October 1, 2000; 279(4): F718 - F727. [Abstract] [Full Text] [PDF]

				T. Hammoud, J.-F. Tanguay, and M. G. Bourassa Management of coronary artery disease: therapeutic options in patients with diabetes J. Am. Coll. Cardiol., August 1, 2000; 36(2): 355 - 365. [Abstract] [Full Text] [PDF]

				H. P. Kohler and P. J. Grant Plasminogen-Activator Inhibitor Type 1 and Coronary Artery Disease N. Engl. J. Med., June 15, 2000; 342(24): 1792 - 1801. [Full Text] [PDF]

				D. A. Lane and P. J. Grant Role of hemostatic gene polymorphisms in venous and arterial thrombotic disease Blood, March 1, 2000; 95(5): 1517 - 1532. [Full Text] [PDF]

				S. Lopez, F. Peiretti, B. Bonardo, I. Juhan-Vague, and G. Nalbone Tumor Necrosis Factor alpha Up-regulates in an Autocrine Manner the Synthesis of Plasminogen Activator Inhibitor Type-1 during Induction of Monocytic Differentiation of Human HL-60 Leukemia Cells J. Biol. Chem., February 4, 2000; 275(5): 3081 - 3087. [Abstract] [Full Text] [PDF]

				B. E. Sobel Increased Plasminogen Activator Inhibitor-1 and Vasculopathy : A Reconcilable Paradox Circulation, May 18, 1999; 99(19): 2496 - 2498. [Full Text] [PDF]

				K. Okada, T. Fujita, K. Minamoto, H. Liao, Y. Naka, and D. J. Pinsky Potentiation of Endogenous Fibrinolysis and Rescue from Lung Ischemia/Reperfusion Injury in Interleukin (IL)-10-reconstituted IL-10 Null Mice J. Biol. Chem., July 7, 2000; 275(28): 21468 - 21476. [Abstract] [Full Text] [PDF]

This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Sobel, B. E. Articles by Gold, H. Search for Related Content PubMed PubMed Citation Articles by Sobel, B. E. Articles by Gold, H.