scholarly journals Adaptive Upregulation of Clumping Factor A (ClfA) by Staphylococcus aureus in the Obese, Type 2 Diabetic Host Mediates Increased Virulence

2017 ◽  
Vol 85 (6) ◽  
Author(s):  
Christopher W. Farnsworth ◽  
Eric M. Schott ◽  
Sarah E. Jensen ◽  
Jacob Zukoski ◽  
Abigail M. Benvie ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Plasminogen Activator Inhibitor ◽  
Hypercoagulable State ◽  
Diabetic Patients ◽  
Fibrin Deposition ◽  
Plasminogen Activator Inhibitor 1 ◽  
Content Type ◽  
Host Immune Responses

ABSTRACT Obesity and associated type 2 diabetes (T2D) are important risk factors for infection following orthopedic implant surgery. Staphylococcus aureus, the most common pathogen in bone infections, adapts to multiple environments to survive and evade host immune responses. Whether adaptation of S. aureus to the unique environment of the obese/T2D host accounts for its increased virulence and persistence in this population is unknown. Thus, we assessed implant-associated osteomyelitis in normal versus high-fat-diet obese/T2D mice and found that S. aureus infection was more severe, including increases in bone abscesses relative to nondiabetic controls. S. aureus isolated from bone of obese/T2D mice displayed marked upregulation of four adhesion genes (clfA, clfB, bbp, and sdrC), all with binding affinity for fibrin(ogen). Immunostaining of infected bone revealed increased fibrin deposition surrounding bacterial abscesses in obese/T2D mice. In vitro coagulation assays demonstrated a hypercoagulable state in obese/T2D mice that was comparable to that of diabetic patients. S. aureus with an inactivating mutation in clumping factor A (clfA) showed a reduction in bone infection severity that eliminated the effect of obesity/T2D, while infections in control mice were unchanged. In infected mice that overexpress plasminogen activator inhibitor-1 (PAI-1), S. aureus clfA expression and fibrin-encapsulated abscess communities in bone were also increased, further linking fibrin deposition to S. aureus expression of clfA and infection severity. Together, these results demonstrate an adaptation by S. aureus to obesity/T2D with increased expression of clfA that is associated with the hypercoagulable state of the host and increased virulence of S. aureus.

Anti-thrombotic Effect of a PAI-1 Inhibitor in Rats Given Endotoxin

1996 ◽  
Vol 75 (01) ◽  
pp. 118-126 ◽  
Author(s):  
T Abrahamsson ◽  
V Nerme ◽  
M Strömqvist ◽  
B Åkerblom ◽  
A Legnehed ◽  
...  
Keyword(s):  
Plasminogen Activator Inhibitor ◽  
Rat Plasma ◽  
Clot Lysis ◽  
Fibrin Deposition ◽  
Plasminogen Activator Inhibitor 1 ◽  
Fab Fragment ◽  
Dose Dependent Decrease ◽  
Pai 1

SummaryThe aim of this study was to investigate the anti-thrombotic effects of an inhibitor of the plasminogen activator inhibitor-1 (PAI-1) in rats given endotoxin. In studies in vitro, PRAP-1, a Fab-fragment of a polyclonal antibody against human PAI-1, was shown to inhibit PAI-1 activity in rat plasma as well as to stimulate clot-lysis of the euglobulin fraction derived from rat plasma. Endotoxin administered to anaesthetised rats produced a marked increase in plasma PAI-1 activity. To study fibrin formation and lysis in vivo after intravenous (i. v.) injection of the coagulant enzyme batroxobin, 125I-fibrinogen was administered to the animals. The thrombi formed by batroxobin were rapidly lysed in control animals, while the rate of lysis was markedly attenuated in rats given endotoxin. PRAP-1 was administered i.v. (bolus + infusion) to rats given endotoxin and batroxobin and the PAI-1 inhibitor caused a dose-dependent decrease in the 125I-fibrin deposition in the lungs. An immunohistochemical technique was used to confirm this decrease in density of fibrin clots in the tissue. Furthermore, PRAP-1 decreased plasma PAI-1 activity in the rats and this reduction was correlated to the decrease in lung 125I-fibrin deposition at the corresponding time point. It is concluded that in this experimental model the PAI-1 antibody PRAP-1 may indeed inhibit thrombosis in animals exposed to endotoxin.

The Effect of Insulin Treatment on the Balance between Tissue Plasminogen Activator and Plasminogen Activator Inhibitor-1 in Type 2 Diabetic Patients

1992 ◽  
Vol 68 (03) ◽  
pp. 253-256 ◽  
Author(s):  
Thomas Vukovich ◽  
Sylvia Proidl ◽  
Paul Knöbl ◽  
Harald Teufelsbauer ◽  
Christoph Schnack ◽  
...  
Keyword(s):  
Plasminogen Activator ◽  
Insulin Treatment ◽  
Plasminogen Activator Inhibitor ◽  
Diabetic Patients ◽  
Plasminogen Activator Inhibitor 1 ◽  
Type 2 Diabetic Patients ◽  
Glycemic Regulation ◽  
Type 2 Diabetic ◽  
Pai 1

SummaryBeside hypercoagulation and hyperactivated platelets disturbances of the fibrinolytic system towards hypofibrinolysis have been reported to be associated with both glycemic and lipidemic derangement in diabetic patients. In the present prospective follow-up study the effect of 16 weeks insulin treatment and glycemic regulation on plasma levels of tissue plasminogen activator (tPA) and plasminogen activator inhibitor-1 (PAI-1), the main regulators of fibrinolysis, was investigated in 19 type-2 diabetic patients with secondary failure to sulphonylureas. A similar glycemic regulation was obtained in a control group of 10 type 2 diabetic patients with sufficient metabolic response to strict dietary treatment and continuation of sulphonylurea treatment. Compared to 27 healthy subjects levels of tPA and PAI-1 were not significantly increased in type 2 diabetic patients before metabolic intervention. Although a hypofibrinolytic state due to an increase of PAI-1 levels was previously reported in obese hyperinsulinemic patients, no effect of insulin treatment on both tPA- and PAI-1 levels was observed in the present study including patients with only slightly increased body mass index (median 26.0 kg/m2). By correlation analysis PAI-1 levels were significantly related to serum cholesterol (R = 0.52) and glycemic control (glucose R = 0.41) in the whole group of diabetic patients at entry and in both subgroups after 16 weeks of treatment (insulin group: cholesterol R = 0.46, HbA1c R = 0.51; sulphonylurea group: cholesterol R = 0.59, HbA1c R = 0.58). In healthy subjects tPA and PAI-1 was correlated to serum insulin (R = 0.54, R = 0.56) and triglycerides (R = 0.46, R = 0.40). In conclusion, our results indicate that insulin treatment associated with metabolic improvement has no adverse effect to fibrinolysis in type 2 diabetic patients.

PAI-1 and D-Dimer in Type 2 Diabetic Women With Asymptomatic Macrovascular Disease Assessed by Carotid Doppler

2009 ◽  
Vol 16 (2) ◽  
pp. 204-208 ◽  
Author(s):  
Anna Letícia Soares ◽  
Pedro Wesley Rosário ◽  
Michelle Aparecida Ribeiro Borges ◽  
Marinez Oliveira Sousa ◽  
Ana Paula Salles Moura Fernandes ◽  
...  
Keyword(s):  
Carotid Plaque ◽  
Macrovascular Disease ◽  
Intima Media Thickness ◽  
Plasminogen Activator Inhibitor ◽  
Diabetic Patients ◽  
Plasminogen Activator Inhibitor 1 ◽  
Type 2 Diabetic ◽  
Pai 1 ◽  
D Dimer

Asymptomatic diabetic patients with different degrees of macrovascular complications can present different hemostatic changes. At this study, plasminogen activator inhibitor-1 (PAI-1) and D-dimer were evaluated in 12 women without diabetes and 64 type 2 diabetic women. All patients were classified into 3 different categories according to the carotid intima-media thickness (IMT) assessed by Doppler: 25 with <1 mm (normal), 15 with >1 mm and without plaque (intermediate), and 24 with stenosis lower than 50% of the vessel lumen (plaque). The results showed increased plasma D-dimer in type 2 diabetic women with carotid plaque when compared to the other groups. High levels of PAI-1 were observed in all the 3 groups of diabetic women when compared to women without diabetes. Our results suggest that high levels of PAI-1 in type 2 diabetic women are only associated with diabetes and are not associated with macrovascular progression; however, it seems that D-dimer plasma levels are associated with carotid plaque.

scholarly journals Relationship among HbA1c and Some Markers of Endothelial Damage in Type 2 Diabetes Mellitus

2019 ◽  
pp. 1-6
Author(s):  
Ifeanyichukwu Martin Ositadinma ◽  
Ngwu Amauche Martina ◽  
Eluke Blessing Chekwube
Keyword(s):  
Diabetes Mellitus ◽  
Type 2 Diabetes ◽  
Type 2 Diabetes Mellitus ◽  
Plasminogen Activator ◽  
Plasma Levels ◽  
Plasminogen Activator Inhibitor ◽  
Diabetic Patients ◽  
Plasminogen Activator Inhibitor 1 ◽  
Activator Inhibitor

Background: A number of processes regulating the thrombolytic balance are impaired in diabetic patients as a result of dysfunction of endothelial cells leading to a hypercoagulative state. Von Willebrand factor (VWF) is an important marker of endothelial dysfunction. Plasminogen activator inhibitor-1 antigen (PAI-1-Ag), the major physiological inhibitor of tissue plasminogen activator (tPA), is mainly produced by endothelium. The aim of this study is to measure plasma levels of von Willebrand factor, Plasminogen activator inhibitor-1 antigen in type 2 diabetes mellitus patients and to correlate with glycated haemoglobin (HbA1c). Study Design: This prospective cohort study was conducted on 30 diagnosed type 2 DM patients who were about to start treatment. Place and Duration of Study: Medical outpatient (MOP) clinic of Enugu State University of Science and Technology Teaching Hospital (ESUTTH), between January and December 2016. Methodology: We included 30 patients (13 men, 17 women; age range 40-80 years) with type 2 diabetes mellitus. Blood samples were drawn from the patients before they commenced treatment, six months into the treatment and at twelve months of the treatment. Blood samples were also drawn from 25 age matched non diabetic patients. Plasma von Willebrand factor and Plasminogen activator inhibitor-1 antigen levels were determined by Enzyme linked immunosorbent assay. Glycated haemoglobin (HbA1c) and fasting blood sugar (FBS) levels were also evaluated along with them. Results: This study was conducted on 30 type 2 DM patients consisting of 13 males and 17 females. At treatment naïve, mean levels of vWF were significantly increased (45.48 +/- 6.46) in male type 2 Diabetic patients compared to the control (20.45 +/- 0.26). Six months into treatment mean levels of vWF were significantly increased (48.18 +/- 4.99) in female type 2 Diabetic patients compared to the control (37.64 +/- 7.93). The plasma levels of vWF were significantly and positively correlated with HbA1c at six months into treatment in male type 2 DM patients. The plasma levels of vWF were also significantly and positively correlated with PAI-1 at six and twelve months into treatment in both genders. Conclusion: There was strong significant positive correlation between plasma levels of vWF and PAI-1 in type 2 diabetes mellitus patients.

scholarly journals Plasminogen activator inhibitor-1 gene polymorphism as a risk factor for vascular complications in type 2 diabetes mellitus

2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Fatma A. Khalaf ◽  
Hatem R. Ibrahim ◽  
Hanan M. Bedair ◽  
Maha M. Allam ◽  
Amr A. Elshormilisy ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Gene Polymorphism ◽  
Vascular Complications ◽  
Plasminogen Activator Inhibitor ◽  
Diabetic Patients ◽  
Plasminogen Activator Inhibitor 1 ◽  
Increased Risk ◽  
Activator Inhibitor ◽  
Pai 1

Abstract Background Diabetes mellitus (DM) can lead to microvascular and macrovascular damages through hyperglycemia that is the main cause of diabetic complications. Other factors such as hypertension, obesity, and hyperlipidemia may worsen or accelerate the others. Several studies have revealed definitive genetic predispositions to the development of type 2 diabetes mellitus (T2DM) and development of vascular complications. This study aimed to address the association between plasminogen activator inhibitor-1 (PAI-1) gene polymorphism and T2DM, and if this gene polymorphism may have a possible role in the development of vascular complications in T2DM. This study is a case control; it included 200 patients with T2DM, 117 patients had no vascular complications, and 83 had previous vascular complications (VCs). One hundred eighty volunteer blood donors were selected as a healthy control group. All patients and controls were subjected to clinical examination, and laboratory investigations included lipid profile, fasting and 2 h blood glucose, complete blood cell count, d-dimer, PAI-1, thrombin activatable fibrinolysis inhibitor (TAFI), and detection of PAI-1 gene polymorphism by real-time polymerase chain reaction (PCR). Results The most prevalent genotype of PAI-1 gene polymorphism in all studied groups, including controls, was 4G/5G with the highest allele frequency as 4G. The 4G/5G and 4G/4G genotypes were associated with increased risk of DM development as compared to 5G/5G genotype. The 4G/5G and 4G/4G genotypes also had a highly significant increased risk of VCs among diabetic patients, as compared to 5G/5G. The 4G allele also was highly associated with DM with VCs. The d-dimer TAFI, PAI-1 showed the highest levels in 4G/5G genotype followed by 4G/4G genotype. The lowest level was expressed in 5G/5G genotype in diabetic patients with and without VCs. The univariable analysis showed that genotypes 4G/5G and 4G/4G were potentially risk factors for development of VCs with T2DM patients. Conclusion This study concludes that the PAI-1 4G/5G polymorphism may be associated with T2DM and may be considered as a risk factor for development of thrombotic events. It may also help in selection and dosing of patients being treated with anticoagulant and fibrinolytic agents. Further large-scale studies are recommended to assess the possible role of environmental factors and gene interactions in the development of T2DM vascular risks.

scholarly journals Role of plasminogen activator inhibitor-1 in promoting fibrin deposition in rabbits infused with ancrod or thrombin

Blood ◽  
1993 ◽  
Vol 82 (12) ◽  
pp. 3631-3636 ◽  
Author(s):  
C Krishnamurti ◽  
C Bolan ◽  
CA Colleton ◽  
TM Reilly ◽  
BM Alving
Keyword(s):  
Plasminogen Activator ◽  
Plasminogen Activator Inhibitor ◽  
Fibrin Deposition ◽  
Plasminogen Activator Inhibitor 1 ◽  
Elevated Activity ◽  
Activator Inhibitor ◽  
Pai 1

The role of defective fibrinolysis caused by elevated activity of plasminogen activator inhibitor-1 (PAI-1) in promoting fibrin deposition in vivo has not been well established. The present study compared the efficacy of thrombin or ancrod, a venom-derived enzyme that clots fibrinogen, to induce fibrin formation in rabbits with elevated PAI-1 levels. One set of male New Zealand rabbits received intravenous endotoxin to increase endogenous PAI-1 activity followed by a 1-hour infusion of ancrod or thrombin; another set of normal rabbits received intravenous human recombinant PAI-1 (rPAI-1) during an infusion of ancrod or thrombin. Thirty minutes after the end of the infusion, renal fibrin deposition was assessed by histopathology. Animals receiving endotoxin, rPAI-1, ancrod, or thrombin alone did not develop renal thrombi. All endotoxin-treated rabbits developed fibrin deposition when infused with ancrod (n = 4) or thrombin (n = 6). Fibrin deposition occurred in 7 of 7 rabbits receiving both rPAI-1 and ancrod and in only 1 of 6 receiving rPAI-1 and thrombin (P “ .01). In vitro, thrombin but not ancrod was inactivated by normal rabbit plasma and by purified antithrombin III or thrombomodulin. The data indicate that elevated levels of PAI-1 promote fibrin deposition in rabbits infused with ancrod but not with thrombin. In endotoxin-treated rabbits, fibrin deposition that occurs with thrombin infusion may be caused by decreased inhibition of procoagulant activity and not increased PAI-1 activity.

scholarly journals In VitroPharmacodynamics of Vancomycin against Methicillin-Susceptible and -Resistant Staphylococcus aureus: Considering the Variability in Observed Tissue Exposure

2015 ◽  
Vol 60 (2) ◽  
pp. 955-961 ◽  
Author(s):  
Yukihiro Hamada ◽  
Joseph L. Kuti ◽  
David P. Nicolau
Keyword(s):  
Staphylococcus Aureus ◽  
Diabetic Patients ◽  
Exposure Level ◽  
Target Tissue ◽  
Time Curve ◽  
Bacterial Killing ◽  
Content Type ◽  
Complicated Skin ◽  
Exposure Levels

ABSTRACTVancomycin is considered a first-line antibiotic for complicated skin and skin structure infections (cSSSI) because of the risk of methicillin-resistantStaphylococcus aureus(MRSA). The vancomycin exposure of tissue can vary widely in patients with cSSSI, yet most models test only the average exposure. Thein vitropharmacodynamic model was used to simulate three tissue exposure levels attained by administering vancomycin at 1 g every 12 h (q12h), based on the median (50th), 25th, and 10th percentile tissue area under the concentration-time curve (AUC) values observed during anin vivomicrodialysis study of diabetic patients. Four clinical isolates (two of MRSA [vancomycin MIC, 1 and 2 μg/ml] and two of methicillin-susceptibleS. aureus[MSSA] [MIC, 1 and 2 μg/ml]) were evaluated. Experiments were performed over 72 h in duplicate. Time-kill curves were constructed, and the area under the bacterial killing and regrowth curve (AUBC) during the final 24-h dosing interval (48 to 72 h) (AUBC48–72) was calculated. Reductions in the 72-h number of CFU/ml and AUBC48–72at the different exposure levels were compared. Target tissue vancomycin exposure levels for the 50th (AUC0–12, 102.0 ± 9.1 μg · h/ml), 25th (AUC0–12, 44.3 ± 1.8 μg · h/ml), and 10th (AUC0–12, 25.3 ± 3.1 μg · h/ml) percentiles were obtained in all studies. No differences in the 72-h number of CFU or AUBC were observed between exposure levels when all of the isolates were analyzed together. However, for the two MRSA isolates, the 10th percentile exposure level achieved a lower 72-h number of CFU/ml (−1.4 ± 0.4 log10CFU/ml,P= 0.007) and a greater AUBC48–72(97.1 ± 20.0 log10CFU · h/ml,P= 0.011) than the higher exposure levels. The majority of the tissue exposure levels achieved with a vancomycin dosing regimen of 1 g q12h resulted in substantial killing of MSSA and MRSA; however, the lowest exposure levels observed in a minority of the population may explain the poor vancomycin response.

scholarly journals Defects in Innate Immunity Predispose C57BL/6J-Leprdb/Leprdb Mice to Infection by Staphylococcus aureus

2008 ◽  
Vol 77 (3) ◽  
pp. 1008-1014 ◽  
Author(s):  
Sunny Park ◽  
Jeremy Rich ◽  
Frank Hanses ◽  
Jean C. Lee
Keyword(s):  
Type 2 Diabetes ◽  
Staphylococcus Aureus ◽  
Innate Immunity ◽  
Bacterial Infections ◽  
Leptin Receptor ◽  
Diabetic Patients ◽  
Bacterial Killing ◽  
Persistent Hyperglycemia

ABSTRACT Foot and ankle infections are the most common cause of hospitalization among diabetic patients, and Staphylococcus aureus is a major pathogen implicated in these infections. Patients with insulin-resistant (type 2) diabetes are more susceptible to bacterial infections than nondiabetic subjects, but the pathogenesis of these infections is poorly understood. C57BL/6J-Lepr db /Lepr db (hereafter, db/db) mice develop type 2 diabetes due to a recessive, autosomal mutation in the leptin receptor. We established a S. aureus hind paw infection in diabetic db/db and nondiabetic Lepr +/+ (+/+) mice to investigate host factors that predispose diabetic mice to infection. Nondiabetic +/+ mice resolved the S. aureus hind paw infection within 10 days, whereas db/db mice with persistent hyperglycemia developed a chronic infection associated with a high bacterial burden. Diabetic db/db mice showed a more robust neutrophil infiltration to the infection site and higher levels of chemokines in the infected tissue than +/+ mice. Blood from +/+ mice killed S. aureus in vitro, whereas db/db blood was defective in bacterial killing. Compared with peripheral blood neutrophils from +/+ mice, db/db neutrophils demonstrated a diminished respiratory burst when stimulated with S. aureus. However, bone marrow-derived neutrophils from +/+ and db/db mice showed comparable phagocytosis and bactericidal activity. Our results indicate that diabetic db/db mice are more susceptible to staphylococcal infection than their nondiabetic littermates and that persistent hyperglycemia modulates innate immunity in the diabetic host.

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