© 1997 by European Society of Cardiology
Copyright © 1997, European Society of Cardiology
Circulating transforming growth factor β1 and coronary artery disease
Department of Cardiovascular Medicine, University of New South Wales, Prince Henry/Prince of Wales Hospitals, Sydney, Australia
* Corresponding author. Department of Cardiovascular Medicine, Clinical Sciences Building, Prince Henry Hospital, Little Bay, NSW 2036, Australia. Tel.: +61 (2) 382 5026; fax: +61 (2) 382 5755; e-mail: x.l.wang@unsw.edu.au
Received 3 October 1996; accepted 30 December 1996
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Abstract |
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 Top Abstract 1 Introduction2 Methods3 Results4 DiscussionReferences |
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Objective: Transforming growth factor β1 (TGF-β1), a multifunctional cytokine, is involved in many physiological and pathological processes and possibly in atherogenesis. Methods: We explored the association between circulating plasma TGF-β1 measured by ELISA and coronary artery disease (CAD) assessed angiographically in 371 Caucasian patients (269 men and 102 women) aged
65 years. Results: While mean±s.e.m. total TGF-β1 was not different among patients with (56.9±1.5 ng/ml) or without (54.6±2.8 ng/ml) angiographically demonstrable CAD, naturally active TGF-β1 was significantly higher in CAD patients (1.74±0.18 vs 0.96±0.17 ng/ml, P<0.01). Active TGF-β1 increased with the number of major coronary arteries with more than 50% luminal obstruction (P<0.01), and patients with triple vessel disease had twice the level of those with no or mild vessel disease (2.15±0.46 vs 1.12±0.14 ng/ml, P<0.001). We found no relationship between TGF-β1 and Lp(a), but TGF-β1 was significantly correlated with circulating fibrinogen (r=0.178, P=0.005) and fasting glucose (r=0.177, P=0.007) levels. Conclusions: Our study identifies an increase in active TGF-β1 levels with both the occurrence and severity of CAD which is independent of standard CAD risk factors. This may reflect a ‘double-edged sword’ effect of TGF-β1 in that it may reduce atherogenesis by inhibiting smooth muscle cell proliferation but, when there is ongoing vessel wall injury, enhance it by promoting excessive extracellular matrix accumulation. The outcome could represent a complex balance between these two competing influences.
KEYWORDS TGF-β1; Coronary artery disease; Lipoprotein(a); Fibrinogen; Human
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1 Introduction |
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TopAbstract1 Introduction2 Methods3 Results4 DiscussionReferences |
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Transforming growth factor-β (TGF-β) is a multifunctional cytokine which plays an important role in regulating repair and regeneration following tissue injury [1, 2]. It consists of a family of three isoforms, TGF-β1, 2, and 3, which are structurally and functionally closely related to one another; and TGF-β1 is the most abundant isoform [1, 2]. TGF-β1 is synthesized virtually in all cell types and secreted as a latent complex combined with a latency-associated protein. Once secreted, the latent complex can be activated by pH changes, heat, or proteolytic enzymes to release mature dimeric TGF-β [1, 2]. In the vascular system, coexistence of endothelial cells and smooth muscle cells is essential for in vivo TGF-β1 activation [1, 2].
TGF-β1 is intimately involved in many cellular processes. It induces cells surviving after injury to produce extracellular matrix by stimulating the synthesis of individual matrix components [2]. Unknown mechanisms shut down this process when repair is complete. Failure to shut it down because of a defect in TGF-β1 regulation or continuous injury may result in accelerated production of TGF-β1 and extracellular matrix leading to excessive tissue fibrosis [2]. TGF-β1 has other functions in that it also regulates immune responses and modulates cell growth.
In recent years it has been postulated that TGF-β1 may be involved in atherogenesis [3–12]—a process involving endothelial dysfunction, vascular smooth muscle cell proliferation and excessive extracellular matrix accumulation in the blood vessel wall. In vitro studies have shown that TGF-β1 can preserve endothelial function [4], inhibit smooth muscle cell proliferation [6], and prevent neutrophils and lymphocytes from adhering to endothelium [8, 9], changes consistent with TGF-β1 tending to inhibit atherogenesis. Indeed, Grainger et al. reported that serum levels of active TGF-β1 were depressed in 31 patients with triple vessel coronary disease [7]. On the other hand, however, TGF-β1 could enhance atherogenesis by mediating excessive extracellular matrix accumulation [12–14]and the finding that TGF-β1 may promote thrombogenesis by down-regulation of thrombomodulin [15]. The recently identified increased expression of TGF-β1 in human vascular re-stenosis lesions [11]and the observation that the use of an antibody against TGF-β1 suppresses intimal hyperplasia [12]would support this alternative role. All these findings suggest that there is a complex balance of TGF-β1-mediated responses influencing atherogenic outcomes.
In view of these apparently contradictory actions in relation to atherogenesis that TGF-β1 may have, we explored the association between circulating TGF-β1 and the severity of coronary artery disease (CAD) in a large patient population in whom the presence and extent of coronary disease were established by coronary angiography.
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2 Methods |
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TopAbstract1 Introduction2 Methods3 Results4 DiscussionReferences |
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2.1 Patients
We studied Caucasian patients aged 65 years or less, both men and women, consecutively referred to the Eastern Heart Clinic at Prince Henry Hospital for coronary angiography over a 9-month period in 1994 and 1995. We excluded only patients shown to have significant left main disease (>50% luminal obstruction) because it was difficult to categorise this small proportion of the total (5%) within the classification system we used (see below). Patients receiving warfarin or heparin therapy at the time of study were also excluded since they may interfere with quantitative measurements of lipoproteins and fibrinogen. A written consent was obtained from every patient after a full explanation of the study which was approved by the Ethics Committee of the University of New South Wales.
A 4 ml venous blood sample was drawn from a catheter immediately after it was inserted into the femoral vein before the angiogram and after at least a 6 h fast. The blood was collected into an EDTA sample tube and stored at 4°C for a maximum of 5 h before centrifugation at 3500 rpm (2000xg) for 10 min at 4°C and 0.8–1.2 ml plasma obtained from each tube. To avoid disturbing the buffy coat containing white blood cells and platelets, a thin layer of plasma (approximately 0.5 ml) was always left on top of the buffy coat. The plasma was stored at –70°C in aliquots for 2–12 months until the TGF-β1 analysis.
2.2 Measurements of TGF-β1 levels
To measure the plasma active and total (active+latent) TGF-β1 levels, we used the Promega ELISA system for the TGF-β1 assays [16]. This is a sandwich ELISA system designed to measure biologically active TGF-β1. The plasma total TGF-β1 was assayed after acid activation of the plasma by adding 1 µl of 1N HCl to 50 µl diluted plasma (1:5 in DPBS). The reaction solution was mixed and incubated at room temperature for 15 min before it was neutralised by 1 µl of 1N of NaOH. It was further diluted to 1:150 in DPBS buffer (containing K+, Na+, Cl–, HPO4=, Ca2+ and Mg2+, pH=7.35) before it was added to the ELISA plate. Acid activation is the most commonly used in vitro method to release biologically active TGF-β1 [17]. To measure the amount of naturally active TGF-β1 in plasma, samples were added directly into the ELISA plate after 1:75 dilution in DPBS buffer.
In this assay, monoclonal anti-TGF-β1 antibody was used as the coating antibody which binds soluble TGF-β1 from solution. The captured TGF-β1 is bound by a second polyclonal antibody specifically reactive against biologically active TGF-β1. The polyclonal antibody was generated in rabbits with the immunogen being acid-activated intact human TGF-β1. The ELISA system is specific for TGF-β1 and there was only a 1.6% cross-reactivity with TGF-β2 and 0.7% with TGF-β3 at 10 ng/ml concentration. The recovery rate, assessed by spiking plasma (endogenous TGF-β1: 13.4 ng/ml) with natural human TGF-β1 (9.3 and 18.8 ng/ml) obtained from platelets (Promega), was 96–113%. The detection limits of TGF-β1 was 16 and 1000 pg/ml using recombinant TGF-β1 standard.
The standard curve was produced by a 2-fold serial dilution with final concentrations of 0, 15.6, 31.3, 62.5, 125, 250, 500, 1000 pg/ml. The colour change of the final reaction was measured at a wavelength of 450 nm for the optical density and the standard curve (TGF-β1 concentrations vs absorbances) was linear in a linear-linear scale. There was also a linear increase in the absorbances of the serially diluted plasma sample from a patient (1:50, 1:100, 1:200, and 1:400) in the ELISA. A single patient plasma sample was stored in aliquots at –70°C and used as a control in each assay during the period of 8 months in which the assays were conducted. The measured levels of active TGF-β1 (1.45 ng/ml, range 1.33–1.51 ng/ml) and total TGF-β1 (34.5 ng/ml, range 31.2–37.4 ng/ml) remained relatively constant over the period. There was no trend towards an increase or decrease during the storage period. The average intra-assay CV and inter-assay CV for measurements in our laboratory were 5.1 and 8.9%, respectively, for concentrations ranging from 59 to 930 pg/ml.
2.3 Biochemical analysis
Total cholesterol, HDL-C, triglyceride and glucose levels were measured by the hospital's Clinical Chemistry Department using standard enzymatic methods. The LDL-cholesterol levels were calculated using the Friedewald formula. The fibrinogen levels were measured in the hospital's Department of Haematology. Levels of apo-AI, apo-B and Lp(a) were measured using ELISA methods developed in our laboratory [17].
2.4 Documentation of CAD severity
The severity of coronary artery disease was determined by the number of significantly stenosed coronary arteries as follows. The angiograms were assessed by 2 cardiologists before the availability of assay results. Each angiogram was classified as revealing either no coronary lesion with more than 50% luminal stenosis or as having 1, 2, or 3 major epicardial coronary arteries with more than 50% luminal obstructions. Those without significantly diseased vessels were further subgrouped into those with angiographically normal coronary arteries and those with mild lesions (i.e., 50% or less luminal stenosis). As previously [17], we also used the Green Lane coronary scoring system which provides a numerical value for lesion severity and takes account of the amount of myocardium supplied by an affected vessel; the maximal score is 15.
2.5 Documentation of other medical conditions
The relevant history was obtained for each patient using a questionnaire with standardised choices of answers to be ticked during the interview. We recorded the presence or absence (yes/no) of a history of myocardial infarction, hypertension requiring treatment, diabetes, and angina pectoris. The presence or absence of CAD among first-degree relatives (parents and siblings) and the age of first onset were recorded for a quantitative assessment of family history of premature CAD. We recorded the presence and severity of angina according to whether each patient was experiencing no angina, stable angina, or unstable angina before and during the current hospitalisation. All those classified as having unstable angina had an increase in pain frequency as well as rest pain. The life-time smoking dose in pack-years was recorded as described previously [18], and patients were also divided into non-smokers, current smokers and ex-smokers.
2.6 Statistical analysis
The results are presented as means±s.e.m. We used unpaired Student t-tests for two group comparisons and ANOVA when more than two groups were compared. We also used ANOVA to evaluate possible interactions between independent categorical variables. We used linear regression analysis to assess associations between quantitative variables and Pearson correlation coefficients are reported. Since the distributions of both active TGF-β1 and Lp(a) levels were highly skewed, a non-parametric Mann-Whitney U-test was used for comparisons between two groups and Kruskal-Wallis one-way ANOVA was used when more than two groups were compared.
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3 Results |
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TopAbstract1 Introduction2 Methods3 Results4 DiscussionReferences |
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The demographic information for the 371 patients is shown in Table 1. As expected, men had more unfavourable lipoprotein variables and smoking habits compared to women in relation to increased CAD risk. Both men and women in this study were overweight as shown by their average BMI at 28. But the levels of active and total TGF-β1 as well as the active to total TGF-β1 ratio were not different in men and women.
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3.1 TGF-β1 and CAD risk factors
The relationships between levels of TGF-β1 and relevant measured quantitative variables as assessed by linear regression analysis are shown in Table 2. The levels of both active and total TGF-β1 were significantly associated with levels of fibrinogen and glucose in all patients (Table 2). The same relationships remained statistically significant when the analyses were conducted in men and women separately. There was no relationship between TGF-β1 and age, body mass index (BMI), waist/hip ratio, any lipoproteins or apolipoproteins and, in particular, none with Lp(a) levels (r=0.032, P=0.514) in this patient population. As expected, the life-time smoking dose was correlated with levels of fibrinogen in both men (r=0.255, P=0.0002) and women (r=0.265, P=0.007).
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3.2 TGF-β1 levels and CAD
Total TGF-β1 was not different between patients with and without angiographically demonstrable CAD, but active TGF-β1 was 2 times higher (P<0.001) in those with CAD (Table 3). The ratio of active to total TGF-β1 was correspondingly higher in the CAD patients reflecting the elevated active TGF-β1. When men and women were analysed separately, these relationships remained statistically significant for the men (P<0.001) and the same trends with marginal significance were also observed in the smaller number of women (Table 3). Lp(a) levels were higher in those with CAD (313±14 mg/l) than those without CAD (226±32 mg/l, P=0.037) as we have reported previously [18]. Glucose levels were not different between the two groups, but the CAD patients had higher fibrinogen levels (Table 3).
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When we assessed the levels of TGF-β1 in relation to the CAD severity determined from the number of stenosed vessels (>50% luminal obstruction), there was a linear increase in active TGF-β1 with the increase in the number of significantly diseased vessels while total TGF-β1 remained unchanged (Table 4). The linear relationship was statistically significant in men (P<0.01) and the same trend was also observed in women (P=0.12) among whom patients with triple vessel disease had the highest active TGF-β1 levels. This relationship was also reflected in the active to total TGF-β1 ratio (Table 4). There was also a trend for the coronary score (see Section 2) to correlate with the levels of active TGF-β1 (r=0.104, P=0.063) as shown in Table 2.
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Since the levels of fibrinogen, Lp(a), TC/HDL-C and life-time smoking dose were also elevated in patients with CAD and correlated with CAD severity, we further analysed the relationship between the active TGF-β1 and CAD severity using an ANOVA model in which sex, the presence of diabetes or hypertension were entered as factors and levels of glucose, fibrinogen, Lp(a), TC/HDL-C and life-time smoking dose were controlled as co-variates. The associations between active TGF-β1 and the presence and severity of CAD remained independent and statistically significant (F=9.99, df=1, P=0.002) after controlling for the above variables in the model. The significant relationships between glucose and active TGF-β1 (F=7.87, df=1, P=0.005), and fibrinogen and TGF-β1 (F=8.11, df=1, P=0.005), were also not affected.
3.3 Other medical conditions and TGF-β1 levels
Although patients with angina tended to have higher active TGF-β1 [median: 0.93, range: 0.02–33.2 ng/ml (mean±s.e.m. 1.67±0.18 ng/ml) vs median: 0.74, range: 0.02–15.04 ng/ml (mean±s.e.m. 1.30±0.23 ng/ml), P=0.364], the difference was not statistically significant. However, diabetic patients had significantly higher active TGF-β1 [1.23, 0.02–33.2 ng/ml (mean±s.e.m. 2.16±0.71 ng/ml) vs 0.82, 0.02–25.7 ng/ml (mean±s.e.m. 1.51±0.15 ng/ml), P=0.039]. TGF-β1 levels were not different in patients with or without a past history of myocardial infarction, of hypertension requiring treatment or of a positive family history of premature CAD.
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4 Discussion |
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TopAbstract1 Introduction2 Methods3 Results4 DiscussionReferences |
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Our study identifies a strong positive association between increased active TGF-β1 levels and the occurrence and severity of CAD as assessed by the number of significantly diseased vessels. We cannot determine from our findings whether the increase in active TGF-β1 is a cause or a result of CAD, but they are different from those of Grainger et al. [7]who reported depressed active TGF-β levels among patients with triple vessel coronary disease. By contrast, in our study the highest active TGF-β1 was in the patients with triple vessel disease. For total TGF-β1, however, our findings were the same as those of Grainger et al. in showing no association with CAD.
It is logical to expect that patients with low active TGF-β1 may have more severe CAD since TGF-β1 may be cardiovascular-protective by preserving endothelial function and inhibiting vascular smooth muscle cell proliferation [3–6]. On the other hand, however, overproduction of TGF-β1 may result in an excessive extracellular matrix production [2, 12–14]and contribute to progression of atherosclerosis when it occurs in the vascular wall. It could be that there were more ‘active’ lesions in the sense of injury to the vascular wall and the responses to it in the large number of patients in our series and that this could be the underlying mechanism for our findings of higher circulating active TGF-β1 in patients with CAD, particularly with severe CAD. The correlations with fibrinogen lend some support to this view.
There are however differences between the studies of Grainger et al. [7]and our own in patient selection, in numbers of patients, and in the methods used to measure TGF-β. Our 371 patients were aged 65 years and were a consecutive series of those judged by cardiologists to require coronary angiography for diagnosis and management of CAD; and they were representative of the broad spectrum of CAD severity seen clinically. The data reported by Grainger et al. describe findings in 31 patients with triple vessel coronary disease and 30 age-matched controls. Although the methods for clinical assessment and the end-points used were the same in both the Grainger et al. [7]study and our own, the methods used to measure biologically active TGF-β1 levels were not. Grainger et al. used a truncated form of the TGF-β type II receptor to capture active TGF-β1 in their ELISA system [7]; we used a monoclonal antibody to capture TGF-β1 and a polyclonal anti-TGF-β1 antibody to detect ‘naturally’ active TGF-β1 in our commercial ELISA system [16]which has also been used in other studies [19]. It should be noted that the polyclonal antibody in our system was generated using acid-activated TGF-β1 as the immunogen.
The levels of ‘naturally’ active TGF-β1 in our study were lower than those reported by Grainger et al. [20](4.0±1.9 ng/ml, n=30), by Shirai et al. [21](5.3±3.3 ng/ml, n=9) and by Anscher et al. [22](7.6±1.6 ng/ml, n=10). While we have no explanation at this stage for the apparent inconsistency, the differences could be methodological or due to numbers of patients studied. It should be emphasised that measurements were only in a small number of subjects in each of these 3 studies [20–22]. Since the distribution of active TGF-β1 is highly skewed, measurements in an adequate number of subjects are necessary to establish a reference range of levels. Also the total TGF-β1 (active+latent) was somewhat higher in our study than in that of Grainger et al. [20]. The likelihood of contamination by platelet released TGF-β1 complex into plasma would be minimal in our study because of the sample collection approach employed (see Section 2). This is further supported by a normal distribution of total TGF-β1 (skewness: 0.907±0.125) whilst active TGF-β1 was heavily skewed towards lower levels (skewness: 6.142±0.125). A tourniquet was not used and the platelet layer (buffy coat) was not disturbed during plasma collection; both may affect the plasma total TGF-β1 determination [20, 23]. In the light of these findings, results from studies using different methods to measure plasma TGF-β1 could only be compared when an internationally standardized reference material becomes available. Nevertheless, these considerations do not alter the conclusions of this study.
Since TGF-β1 is a cytokine and expressed in many cell types, many factors (e.g., infection) could influence the production and activation of TGF-β1. In our study we analysed interrelations between TGF-β1 and other potentially confounding factors in relation to atherogenesis. The TGF-β1 levels were significantly correlated with fasting glucose and fibrinogen levels and, as far as we are aware, these in vivo findings have not been reported previously. We have no direct explanation for the relationship between fibrinogen and TGF-β1. However, some in vitro data indicate that TGF-β1 may inhibit the expression of fibrinogen [24]while in a further study TGF-β1 appeared to stimulate the synthesis of fibrinogen in a hepatoma cell line [25]. This may be just another reflection of the complex and apparently contradictory effects of TGF-β1. But the increases may represent responses to vascular injury.
As for glucose, in vitro experimental studies suggest that hyperglycaemia induces TGF-β1 production in endothelial cells [26], and in the proximal tubule and glomerular mesangial cells of the kidney [27, 28]. TGF-β1 also appears to inhibit glucose-stimulated insulin release [28, 29]. But our present study cannot determine whether an increase in glucose contributed to an increase in TGF-β1 or whether the reverse was the case. Nevertheless, neither the levels of glucose, which were not associated with CAD, nor fibrinogen, which was independently associated with CAD, altered the independent association between active TGF-β1 and the presence and severity of CAD.
In conclusion, our study identifies an increase in active TGF-β1 levels in patients with both the occurrence and severity of CAD, and shows that this relationship is independent of other standard CAD risk factors. The present findings further emphasise the importance of active TGF-β1 in atherogenesis. We suggest that whether or not an increase in active TGF-β1 is protective or detrimental in relation to atherogenesis may well be complex and depend upon the balance between a number of competing influences among which on-going vascular wall injury may be especially important.
Time for primary review 20 days.
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Acknowledgements |
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This work was supported by a grant from the National Health and Medical Research Council of Australia. We wish to thank Dr. Nicholas Wilcken, Garvan Institute, Sydney, for reviewing the manuscript; Ms. Lily Fenech, Ms. Shelly Brown, Mr. Steven Brouwer, Dr. Chao Jun Ma, Dr. Greg Cranney and all the nurses in the Eastern Heart Clinic for their assistance in clinical data collection; Ms. Ah Siew Sim, Ms. Renee Badenhop and Dr. Jun Wang for their laboratory assistance. We are also particularly grateful to Dr. R. Michael McCredie and the cardiologists in the Department for allowing us to study their patients.
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References |
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TopAbstract1 Introduction2 Methods3 Results4 DiscussionReferences |
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- MacLellan WR, Brand T, Schneider MD. Transforming growth factor-β in cardiac ontogeny and adaptation [Review]. Circ Res 1993;73:783–791.
- Border WA, Noble NA. Transforming growth factor β in tissue fibrosis. N Engl J Med 1994;331:1286–1292.
- Grainger DJ, Kemp PR, Liu AC, Lawn RM, Metcalfe JC. Activation of transforming growth factor-β is inhibited in transgenic apolipoprotein(a) mice. Nature 1994;370:460–462.
- Kenny D, Coughlan MG, Pagel PS, Kampine JP, Warltier DC. Transforming growth factor beta 1 preserves endothelial function after multiple brief coronary artery occlusions and reperfusion. Am Heart J 1994;127:1456–1461.
- Metcalfe JC, Grainger DJ. Transforming growth factor-beta and the protection from cardiovascular injury hypothesis [Review]. Biochem Soc Trans 1995;23:403–406.
- Halloran BG, Prorok GD, So BJ, Baxter BT. Transforming growth factor-beta 1 inhibits human arterial smooth-muscle cell proliferation in a growth-rate-dependent manner. Am J Surg 1995;170:193–197.
- Grainger DJ, Kemp PR, Metcalfe JC, et al. The serum concentration of active transforming growth factor-β is severely depressed in advanced atherosclerosis. Nature Med 1995;1:74–79.
- Gamble JR, Vadas MA. Endothelial adhesiveness for blood neutrophils is inhibited by transforming growth factor-β. Science 1988;242:97–99.
- Gamble JR, Vadas MA. Endothelial adhesiveness for human T lymphocytes is inhibited by TGF-β. J Immunol 1991;146:1149–1154.
- Wolf YG, Rasmussen LM, Ruoslahti E. Antibodies against transforming growth factor-β1 suppress intimal hyperplasia in a rat model. J Clin Invest 1994;93:1172–1178.
- Nikol S, Isner JM, Pickering JG, Kearney M, Leclerc G, Weir L. Expression of transforming growth factor-β1 is increased in human vascular restenosis lesions. J Clin Invest 1992;90:1582–1592.
- Bahaodri L, Milder J, Gold L, Botney M. Active macrophage-associated TGF-beta colocalizes with type I procollagen gene expression in atherosclerotic human pulmonary arteries. Am J Pathol 1995;146:1140–1149.
- Border WA, Noble NA. Fibrosis linked to TGF-β in yet another disease. J Clin Invest 1995;96:655–656.
- Harper JR, Spiro RC, Gaarde WA, et al. Role of transforming growth factor beta and decorin in controlling fibrosis. Methods Enzymol 1994;245:241–254.
- Ohji T, Urano H, Shirahata A, et al. Transforming growth factor beta 1 and beta 2 induce down-modulation of thrombomodulin in human umbilical vein endothelial cells. Thromb Haemost 1995;73:812–818.
- Promega Corporation. Transforming growth factor β1 ELISA system. Promega Techn Bull 196 1995;1–12.
- Roberts AB, Sporn MB. Physiological actions and clinical applications of transforming growth factor-beta (TGF-beta). [Review]. Growth Factors 1993;8:1–9.
- Wang XL, Tam C, McCredie RM, Wilcken DEL. Determinants of severity of coronary artery disease in Australian men and women. Circulation 1994;89:1974–1981.
- Hafler DA, Windhagen A. Multiple sclerosis: a neuroimmunological perspective. Promega Neural Notes 1995;1:3–6.
- Grainger DJ, Wakefield L, Bethell HW, Farndale RW, Metcalfe JC. Release and activation of platelet latent TGF-beta in blood clots during dissolution with plasmin. Nat Med 1995;1:932–937.
- Shirai Y, Kawata S, Ito N, et al. Elevated levels of plasma transforming growth factor-beta in patients with hepatocellular carcinoma. Japan J Cancer Res 1992;83:676–679.
- Anscher MS, Peters WP, Reisenbichler H, Petros WP, Jirtle RL. Transforming growth factor beta as a predictor of liver and lung fibrosis after autologous bone marrow transplantation for advanced breast cancer. N Engl J Med 1993;328:1592–1598.
- Grainger DJ, Mosedale DE, Metcalfe JC, Weissberg PL, Kemp PR. Active and acid-activatable TGF-beta in human sera, platelets and plasma. Clin Chim Acta 1995;235:11–31.
- Hanssan JH, Chelucci C, Peschle C, Sorrentino V. Transforming growth factor beta (TGF-beta) inhibits expression of fibrinogen and factor VII in a hepatoma cell line. Thromb Haemost 1992;67:478–483.
- Rokita H, Szuba K. Regulation of acute phase reaction by transforming growth factor beta in cultured murine hepatocytes. Acta Biochim Pol 1991;38:241–249.
- Cagliero E, Roth T, Taylor AW, Lorenzi M. The effects of high glucose on human endothelial cell growth and gene expression are not mediated by transforming growth factor-beta. Lab Invest 1995;73:667–673.
- Ziyadeh FN, Sharma K, Ericksen M, Wolf G. Stimulation of collagen gene expression and protein synthesis in murine mesangial cells by high glucose is mediated by autocrine activation of transforming growth factor-beta. J Clin Invest 1994;93:536–542.
- Sekine N, Yamashita N, Kojima I, Miyazaki J, Ogama E. Bimodal effect of transforming growth factor-beta on insulin secretion in MIN6 cells. Diabetes Res Clin Pract 1994;26:7–14.
- Sharma K, Ziyadeh FN. Hyperglycemia and diabetic kidney disease. The case for transforming growth factor-beta as a key mediator [Review]. Diabetes 1995;44:1139–1146.
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S. Sakamaki, Y. Hirayama, T. Matsunaga, H. Kuroda, T. Kusakabe, T. Akiyama, Y. Konuma, K. Sasaki, N. Tsuji, T. Okamoto, et al. Transforming Growth Factor-beta 1 (TGF-beta 1) Induces Thrombopoietin From Bone Marrow Stromal Cells, Which Stimulates the Expression of TGF-beta Receptor on Megakaryocytes and, in Turn, Renders Them Susceptible to Suppression by TGF-beta Itself With High Specificity Blood, September 15, 1999; 94(6): 1961 - 1970. [Abstract] [Full Text] [PDF]
|
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|
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|
F. Samad, K. T. Uysal, S. M. Wiesbrock, M. Pandey, G. S. Hotamisligil, and D. J. Loskutoff Tumor necrosis factor alpha is a key component in the obesity-linked elevation of plasminogen activator inhibitor 1 PNAS, June 8, 1999; 96(12): 6902 - 6907. [Abstract] [Full Text] [PDF]
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|
 M. Pahor, M. B. Elam, R. J. Garrison, S. B. Kritchevsky, and W. B. Applegate Emerging Noninvasive Biochemical Measures to Predict Cardiovascular Risk Arch Intern Med, February 8, 1999; 159(3): 237 - 245. [Abstract] [Full Text] [PDF]
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|
|
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 |
|
 Z. Mallat, A. Gojova, C. Marchiol-Fournigault, B. Esposito, C. Kamate, R. Merval, D. Fradelizi, and A. Tedgui Inhibition of Transforming Growth Factor-{beta} Signaling Accelerates Atherosclerosis and Induces an Unstable Plaque Phenotype in Mice Circ. Res., November 9, 2001; 89(10): 930 - 934. [Abstract] [Full Text] [PDF]
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