Elaboration of type-1 plasminogen activator inhibitor from adipocytes. A potential pathogenetic link between obesity and cardiovascular disease

LGK974 suppresses the formation of deep vein thrombosis in mice with sepsis

BACKGROUND

Sepsis is a disorder characterized by host inflammation and is caused by systemic infection. The inflammatory cytokine storm results in platelet overactivation, leading to coagulation dysfunction and thrombosis, but the underlying mechanism remains poorly understood. Recent evidence has shown that the Wnt/β-catenin signaling pathway is related to sepsis, but its role and mechanism in sepsis complicated with deep vein thrombosis (DVT) are unclear.

METHODS

In this study, a cecal ligation and puncture (CLP)-induced sepsis model and DVT mouse model were constructed by inferior vena cava ligation. The levels of serum inflammatory factors and adhesion molecules were measured in each group, and the thrombus weight and size, hematoxylin-eosin staining, collagen fiber tissue, and transcriptome of the venous wall were analyzed. The activation of the Wnt/β-catenin signal was evaluated by quantitative real-time polymerase chain reaction, Western blotting, ELISA, and immunohistochemical and immunofluorescence methods.

RESULTS

Sepsis significantly promoted the formation of venous wall collagen fibers and DVT. In addition, Porcn significantly upregulated and activated the Wnt/β-catenin signaling pathway in sepsis mouse models with DVT. In contrast, the Wnt signaling inhibitor LGK974 was found to improve the survival rate, decrease thrombosis, and inhibit the expression of inflammation and adhesion molecules in sepsis mice with DVT. Therefore, activation of the Wnt/β-catenin signal may promote the formation of DVT in sepsis mice.

CONCLUSIONS

LGK974 protects against DVT formation in sepsis mice by inhibiting the activation of the Wnt/β-catenin signal and down-regulating the production of proinflammatory cytokines, PAI-1, and adhesion molecules. LGK974 may be a new candidate for the treatment of sepsis complicated with DVT.

Intracellular tPA-PAI-1 interaction determines VLDL assembly in hepatocytes

Apolipoprotein B (apoB)-lipoproteins initiate and promote atherosclerotic cardiovascular disease. Plasma tissue plasminogen activator (tPA) activity is negatively associated with atherogenic apoB-lipoprotein cholesterol levels in humans, but the mechanisms are unknown. We found that tPA, partially through the lysine-binding site on its Kringle 2 domain, binds to the N terminus of apoB, blocking the interaction between apoB and microsomal triglyceride transfer protein (MTP) in hepatocytes, thereby reducing very-low-density lipoprotein (VLDL) assembly and plasma apoB-lipoprotein cholesterol levels. Plasminogen activator inhibitor 1 (PAI-1) sequesters tPA away from apoB and increases VLDL assembly. Humans with PAI-1 deficiency have smaller VLDL particles and lower plasma levels of apoB-lipoprotein cholesterol. These results suggest a mechanism that fine-tunes VLDL assembly by intracellular interactions among tPA, PAI-1, and apoB in hepatocytes.

Plasminogen Activator Inhibitor-1: Potential Inflammatory Marker in Late-life Depression

Objective

Although several previous studies have examined the association between late-life depression and blood adipokine levels, a marker of chronic inflammation, no studies have comprehensively considered the effects of metabolic syndrome, which is known to affect blood adipokine levels. This study examined blood adipokine levels in geriatric depression after adjusting for the effects of metabolic syndrome.

Methods

Participants were selected from the Ansan Geriatric Study (depression group [n = 76] and control group [n = 76]). Blood concentrations of four adipokines (adiponectin, resistin, neutrophil-gelatinase-associated lipocalin [NGAL], and plasminogen activator inhibitor-1 [PAI-1]) were measured using immunoassays. The effects of blood adipokine concentration on the diagnosis of depression were analyzed using multivariate logistic regression to adjust for the effects of metabolic syndrome and potential confounding factors.

Results

When the effects of metabolic syndrome and potential confounding factors were adjusted, only PAI-1 could explain the diagnosis of depression among all the adipokines. The depression group showed a lower blood PAI-1 level than the control group. Adiponectin, resistin, and NGAL could not explain the diagnosis of depression when the effects of metabolic syndrome and potential confounding factors were adjusted.

Conclusion

This study suggests the possibility that the blood PAI-1 levels in clinically pathological late-life depression may show contrasting results to those with subclinical depressive symptoms. Additionally, considering that most previous studies have been conducted with pre-geriatric populations, the study suggests the possibility that geriatric depression may show inflammatory changes with patterns that are different from those of depression in the pre-geriatric population.

SERPINE1 DNA Methylation Levels Quantified in Blood Cells at Five Years of Age Are Associated with Adiposity and Plasma PAI-1 Levels at Five Years of Age

Plasminogen activator inhibitor (PAI-1) expression has been associated with a higher risk of development of obesity. DNA methylation (DNAm) is an epigenetic mechanism regulating gene transcription and likely involved in the fetal programming of childhood obesity. Our study aimed to assess the associations between PAI-1 gene (SERPINE1) DNAm, plasma PAI-1 levels, and adiposity at five years of age. We analyzed DNAm and anthropometric data from 146 girls and 177 boys from the Gen3G prospective birth cohort. We assessed adiposity using BMI z-scores, waist circumference, total skinfolds, and percentages of total, android, and trunk fat measured by dual-energy radiography (DXA). We estimated blood cell DNAm levels at 15 CpG sites within SERPINE1 using the methylationEPIC array. After correction for multiple testing, we found that lower DNAm in SERPINE1 intron 3 (cg11353706) was associated with greater adiposity levels in girls (waist circumference: r = −0.258, p = 0.002; skinfolds: r = −0.212, p = 0. 013; android fat: r = −0.215, p = 0.015; BMI z-score: r = −0.278, p < 0.001) and that lower DNAm in the SERPINE1 promoter (cg19722814) was associated with higher plasma PAI-1 levels in boys (r = −0.178, p = 0.021). Our study suggests that DNAm levels at the SERPINE1 gene locus are negatively correlated with adiposity, but not with plasma PAI-1 levels, in young girls only.

High visceral to subcutaneous fat area ratio predicts early postoperative small bowel obstruction after surgery for colorectal cancer

PURPOSE

Risks for postoperative small bowel obstruction have been demonstrated in several reports, most of which indicated male sex was a risk factor, but with the reason remaining unknown. We tested the hypothesis that it could be because males have more visceral fat than females. This prospective observational study aims to examine risks of early postoperative small bowel obstruction (EPSBO) after colorectal cancer surgery and the association between visceral to subcutaneous fat area ratio (V/S ratio) and EPSBO.

METHODS

Four hundred and seventy-four patients who underwent colectomy for colorectal cancer in our hospital were enrolled in this study. The influence of several factors including V/S ratio on the development of EPSBO was analyzed.

RESULTS

Thirty-one of the 474 patients (6.5%) developed EPSBO. EPSBO occurred more frequently in males (p = 0.03) and cases who developed postoperative anastomotic leakage (p < 0.001) or wound infection (p = 0.02). Higher V/S ratio was strongly related to male sex (p < 0.001). Multivariate analysis revealed higher V/S ratio (OR 2.25; p = 0.049) and anastomotic leakage (OR 5.86; p < 0.001) were independent risk factors for EPSBO.

CONCLUSION

Higher V/S ratio was significantly related to EPSBO, suggesting that one of the reasons EPSBO was more likely to occur in males because they have more visceral fat than females. Preoperative identification of this risk factor could help us watch out for this potential complication.

Embedded Human Periodontal Ligament Stem Cells Spheroids Enhance Cementogenic Differentiation via Plasminogen Activator Inhibitor 1

Spheroids reproduce the tissue structure that is found in vivo more accurately than classic two-dimensional (2D) monolayer cultures. We cultured human periodontal ligament stem cells (HPLSCs) as spheroids that were embedded in collagen gel to examine whether their cementogenic differentiation could be enhanced by treatment with recombinant human plasminogen activator inhibitor-1 (rhPAI-1). The upregulated expression of cementum protein 1 (CEMP1) and cementum attachment protein (CAP), established cementoblast markers, was observed in the 2D monolayer HPLSCs that were treated with rhPAI-1 for 3 weeks compared with that in the control and osteogenic-induction medium groups. In the embedded HPLSC spheroids, rhPAI-1 treatment induced interplay between the spheroids and collagenous extracellular matrix (ECM), indicating that disaggregated HPLSCs migrated and spread into the surrounding ECM 72 h after three-dimensional (3D) culture. Western blot and immunocytochemistry analyses showed that the CEMP1 expression levels were significantly upregulated in the rhPAI-1-treated embedded HPLSC spheroids compared with all the 2D monolayer HPLSCs groups and the 3D spheroid groups. Therefore, 3D collagen-embedded spheroid culture in combination with rhPAI-1 treatment may be useful for facilitating cementogenic differentiation of HPLSCs.

The effect of adenosine monophosphate-activated protein kinase on lipolysis in adipose tissue: an historical and comprehensive review

CONTEXT

Lipolysis is one of the most important pathways for energy management, its control in the adipose tissue (AT) is a potential therapeutic target for metabolic diseases. Adenosine Mono Phosphate-activated Protein Kinase (AMPK) is a key regulatory enzyme in lipids metabolism and a potential target for diabetes and obesity treatment.

OBJECTIVE

The aim of this work is to analyse the existing information on the relationship of AMPK and lipolysis in the AT.

METHODS

A thorough search of bibliography was performed in the databases Scopus and Web of Knowledge using the terms lipolysis, adipose tissue, and AMPK, the unrelated publications were excluded, and the documents were analysed.

RESULTS

Sixty-three works were found and classified in 3 categories: inhibitory effects, stimulatory effect, and diverse relationships; remarkably, the newest researches support an upregulating relationship of AMPK over lipolysis.

CONCLUSION

The most probable reality is that the relationship AMPK-lipolysis depends on the experimental conditions.

Visceral fat-specific regulation of plasminogen activator inhibitor-1 in aged septic mice

Elevated plasma levels of plasminogen activator inhibitor-1 (PAI-1) are documented in patients with sepsis and levels positively correlate with disease severity and mortality. Our previous work demonstrated that visceral adipose tissues (VAT) are a major source of PAI-1, especially in the aged (murine endotoxemia), that circulating PAI-1 protein levels match the trajectory of PAI-1 transcript levels in VAT (clinical sepsis), and that PAI-1 in both VAT and plasma are positively associated with acute kidney injury (AKI) in septic patients. In the current study utilizing preclinical sepsis models, PAI-1 tissue distribution was examined and cellular sources, as well as mechanisms mediating PAI-1 induction in VAT, were identified. In aged mice with sepsis, PAI-1 gene expression was significantly higher in VAT than in other major organs. VAT PAI-1 gene expression correlated with PAI-1 protein levels in both VAT and plasma. Moreover, VAT and plasma levels of PAI-1 were positively associated with AKI markers, modeling our previous clinical data. Using explant cultures of VAT, we determined that PAI-1 is secreted robustly in response to recombinant transforming growth factor β (TGFβ) and tumor necrosis factor α (TNFα) treatment; however, neutralization was effective only for TNFα indicating that TGFβ is not an endogenous modulator of PAI-1. Within VAT, TNFα was localized to neutrophils and macrophages. PAI-1 protein levels were fourfold higher in stromal vascular fraction (SVF) cells compared with mature adipocytes, and among SVF cells, both immune and nonimmune compartments expressed PAI-1 in a similar fashion. PAI-1 was localized predominantly to macrophages within the immune compartment and preadipocytes and endothelial cells within the nonimmune compartment. Collectively, these results indicate that induction and secretion of PAI-1 from VAT is facilitated by a complex interaction among immune and nonimmune cells. As circulating PAI-1 contributes to AKI in sepsis, understanding PAI-1 regulation in VAT could yield novel strategies for reducing systemic consequences of PAI-1 overproduction.

Association of blood pressure and BMI to corrected QT interval in young adults

Hypertension is often associated with obesity. Uncontrolled hypertension can lead to uncorrected cardiac dysautonomia that makes cardiac repolarization abnormally prolonged. Modern dietary habits, stress, and bad lifestyle habits make young adults vulnerable to hazards of health. We planned to study the association of body mass index (BMI) and blood pressure (BP) with corrected QT (QTc) intervals in young adults. After obtaining the written informed consent, 171 subjects were randomly selected in the age group of 18-35 years. A general history and physical examination were done before recording the BMI and BP. A 12-lead electrocardiogram was recorded and QTc calculated using Bazett's formula. The values obtained were compared and statistical analysis done. Of the 171 subjects 14.03% were hypertensive. The QTc interval was found to be prolonged in females and it is prolonged with age, BMI, and BP. QTc was significantly increased among the prehypertensive and hypertensive group and with the overweight and (or) obese BMI group compared with the normotensives and normal BMI group suggesting an altered autonomic homeostasis. This warrants lifestyle modification at a younger age to reduce the cardiovascular risk.

Dissecting molecular details and functional effects of the high-affinity copper binding site in plasminogen activator Inhibitor-1

Plasminogen activator inhibitor-1 (PAI-1) is the primary inhibitor for plasminogen activators, tissue-type plasminogen activator (tPA) and urokinase-type plasminogen activator (uPA). As a unique member in the serine protease inhibitor (serpin) family, PAI-1 is metastable and converts to an inactive, latent structure with a half-life of 1-2 hr under physiological conditions. Unusual effects of metals on the rate of the latency conversion are incompletely understood. Previous work has identified two residues near the N-terminus, H2 and H3, which reside in a high-affinity copper-binding site in PAI-1 [Bucci JC, McClintock CS, Chu Y, Ware GL, McConnell KD, Emerson JP, Peterson CB (2017) J Biol Inorg Chem 22:1123-1,135]. In this study, neighboring residues, H10, E81, and H364, were tested as possible sites that participate in Cu(II) coordination at the high-affinity site. Kinetic methods, gel sensitivity assays, and isothermal titration calorimetry (ITC) revealed that E81 and H364 have different roles in coordinating metal and mediating the stability of PAI-1. H364 provides a third histidine in the metal-coordination sphere with H2 and H3. In contrast, E81 does not appear to be required for metal ligation along with histidines; contacts made by the side-chain carboxylate upon metal binding are perturbed and, in turn, influence dynamic fluctuations within the region encompassing helices D, E, and F and the W86 loop that are important in the pathway for the PAI-1 latency conversion. This investigation underscores a prominent role of protein dynamics, noncovalent bonding networks and ligand binding in controlling the stability of the active form of PAI-1.

Thrombosis in COVID-19

Thrombotic complications are frequent in COVID-19 and contribute significantly to mortality and morbidity. We review several mechanisms of hypercoagulability in sepsis that may be upregulated in COVID-19. These include immune-mediated thrombotic mechanisms, complement activation, macrophage activation syndrome, antiphospholipid antibody syndrome, hyperferritinemia, and renin-angiotensin system dysregulation. We highlight biomarkers within each pathway with potential prognostic value in COVID-19. Lastly, recent observational studies have evaluated a role for the expanded use of therapeutic anticoagulation in COVID-19. We review strengths and weaknesses of these studies, and we also discuss the hypothetical benefit and anticipated challenges of fibrinolytic therapy in COVID-19.

WITHDRAWN: HMGB1 and COX2 are regulated during organ damage following obesity-induced hypertension in a metabolic syndrome mouse model

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Identification of a PAI-1-binding site within an intrinsically disordered region of vitronectin

The serine protease inhibitor, plasminogen activator inhibitor Type-1 (PAI-1) is a metastable protein that undergoes an unusual transition to an inactive conformation with a short half-life of only 1-2 hr. Circulating PAI-1 is bound to a cofactor vitronectin, which stabilizes PAI-1 by slowing this latency conversion. A well-characterized PAI-1-binding site on vitronectin is located within the somatomedin B (SMB) domain, corresponding to the first 44 residues of the protein. Another PAI-1 recognition site has been identified with an engineered form of vitronectin lacking the SMB domain, yet retaining PAI-1 binding capacity (Schar, Blouse, Minor, Peterson. J Biol Chem. 2008;283:28487-28496). This additional binding site is hypothesized to lie within an intrinsically disordered domain (IDD) of vitronectin. To localize the putative binding site, we constructed a truncated form of vitronectin containing 71 amino acids from the N-terminus, including the SMB domain and an additional 24 amino acids from the IDD region. This portion of the IDD is rich in acidic amino acids, which are hypothesized to be complementary to several basic residues identified within an extensive vitronectin-binding site mapped on PAI-1 (Schar, Jensen, Christensen, Blouse, Andreasen, Peterson. J Biol Chem. 2008;283:10297-10309). Steady-state and stopped-flow fluorescence measurements demonstrate that the truncated form of vitronectin exhibits the same rapid biphasic association as full-length vitronectin and that the IDD hosts the elusive second PAI-1 binding site that lies external to the SMB domain of vitronectin.

Systemic Inflammation in Severe Obese Patients Undergoing Surgery for Obesity and Weight-Related Diseases

Background

Obesity is a worldwide disease related to genetic, environmental, and behavioral factors, and it is associated with high rates of morbidity and mortality. Recently, obesity has been characterized by a low-grade inflammatory state known as inflammome indicated by chronic increases in circulating concentrations of inflammatory markers. The purpose of this study was to evaluate the effect of weight loss induced by surgery for obesity and weight-related diseases on pro-inflammatory cytokine (TNF-α) and anti-inflammatory adipokine (adiponectin) levels, and on an adipose-derived hormone (leptin) in severely obese subjects.

Methods

This randomized, controlled trial involved 55 severe obese patients (50 women, age 18–63 years, and body mass index of 35.7–63 kg/m²) who underwent bariatric surgery (BS). Patients with a BMI > 65 kg/m² and clinical and mental instability, or significant and unrealistic expectations of surgery were excluded. Blood samples were collected during the fasting period to analyze tumor necrosis factor alpha (TNF-α), adiponectin, and leptin levels by enzyme-linked immunosorbent assay.

Results

At baseline, no significant difference was observed in the anthropometric, demographic, clinical characteristics and biochemistry and inflammatory markers between the control group (CG) and bariatric surgery group (BSG). The same finding was also observed when we compared the baseline variables to those at the 6-month follow-up in the CG. However, the same variables in the BSG group were significantly different between baseline and the 6-month follow-up after BS.

Conclusions

Weight loss induced by surgery for obesity and weight-related diseases reduced the inflammome state in severely obese patients.

Plasminogen activator inhibitor-1 (PAI-1) expression in endometriosis

Purpose

Deep infiltrating endometriosis (DIE) is defined as an endometriotic lesion penetrating to a depth of >5 mm and is associated with pelvic pain, but the underlying mechanisms are unclear. Our objective is to investigate whether plasminogen activator inhibitor-1 expression (PAI-1) in endometriotic tissues is increased in women with DIE.

Methods

In this blinded in vitro study, immunohistochemistry and Histoscore were used to examine the expression of PAI-1 in glandular epithelium (GECs) and stroma (SCs) in a total of 62 women: deep infiltrating uterosacral/rectovaginal endometriosis (DIE; n = 13), ovarian endometrioma (OMA; n = 14), superficial peritoneal uterosacral/cul-de-sac endometriosis (SUP; n = 23), uterine (eutopic) endometrium from women with endometriosis (UE; n = 6), and non-endometriosis eutopic endometrium (UC; n = 6). The following patient characteristics were also collected: age, American Fertility Society stage, hormonal suppression, phase of menstrual cycle, dysmenorrhea score and deep dyspareunia score.

Results

PAI-1 expression in GECs and SCs of the DIE group was significantly higher than that of SUP group (p = 0.01, p = 0.01, respectively) and UE group (p = 0.03, p = 0.04, respectively). Interestingly, increased PAI-1 expression in GECs and SCs was also significantly correlated with increased dysmenorrhea (r = 0.38, p = 0.01; r = 0.34, p = 0.02, respectively).

Conclusions

We found higher expression of PAI-1 in DIE, and an association between PAI-1 and worse dysmenorrhea.

Effects of puerarin on the AKT signaling pathway in bovine preadipocyte differentiation

Objective

Puerarin has the potential of regulating the differentiation of preadipocytes, but its mechanism of action has not yet been elucidated. Adipocytes found in adipose tissue, the main endocrine organ, are the main sites of lipid deposition, and are widely used as a cell model in the study of in vitro fat deposition. This study aimed to investigate the effects of puerarin on adipogenesis in vitro.

Methods

Puerarin was added to the culture medium during the process of adipogenesis. The proliferation and differentiation of bovine preadipocytes was measured through cell viability and staining with Oil Red O. The content of triacylglycerol (TG) was measured using a triglyceride assay kit. The mRNA and protein expression levels of adipogenic genes, peroxisome proliferator-activated receptor-γ (PPARγ) and CCAAT/enhancer-binding protein-α (C/EBPα), were measured using quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting, respectively.

Results

The addition of puerarin significantly increased adipogenesis of bovine preadipocytes and enhanced the mRNA and protein level expression of PPARγ (p<0.01). The expression of P-Akt increased after adipogenic hormonal induction, whereas puerarin significantly increased PPARγ expression by promoting the Akt signaling component, P-Akt. The mechanism of adipogenesis was found to be related to the phosphorylation level of Ser473, which may activate the downstream signaling of the Akt pathway.

Conclusion

Puerarin was able to promote the differentiation of preadipocytes and improve fat deposition in cattle. The mechanism of adipogenesis was found to be related to the phosphorylation level of Ser473.

Interleukin-4 Boosts Insulin-Induced Energy Deposits by Enhancing Glucose Uptake and Lipogenesis in Hepatocytes

Type 2 diabetes mellitus (T2DM), with dysregulated hepatic gluconeogenesis as the major cause of fasting hyperglycemia, is closely associated with chronic inflammation. We previously demonstrated interleukin-4 (IL-4) improves insulin sensitivity and glucose tolerance while reducing lipid deposits. The present study examined the in vitro effects of IL-4 on insulin signaling molecules, glucose uptake, and lipid metabolism in hepatocytes, as well as in vivo effects on hepatic adiposity, for elucidating the roles of IL-4 in hepatic energy metabolism. Potential interaction between IL-4 and insulin in regulating hepatic metabolism was also investigated. Our results showed that IL-4 enhanced Akt and GSK-3α/β phosphorylations, which in turn promoted glycogen synthesis. IL-4 not only potentiated basal glucose uptake by upregulating glucose transporter 2 expression but also promoted insulin-induced glucose uptake. Additionally, IL-4 increased triglyceride contents through facilitating free fatty acid uptake and expression/activity of lipogenic enzymes. The major effects of IL-4 on the liver were to promote energy storage by boosting insulin-stimulated glucose uptake and lipid synthesis. This study provides evidence to implicate the novel roles of IL-4 in mediating hepatic glucose and lipid metabolism, interactions between immune responses and metabolic homeostasis, and the involvement of IL-4 in metabolic abnormalities.

Modeling anthropometric indices in relation to 10-year (2002-2012) incidence of cardiovascular disease, among apparently healthy individuals: The ATTICA study

AIMS

Body fat accumulation is implicated in the development of cardiovascular disease (CVD). Our objective was to explore potential associations between anthropometric indices and the 10-year CVD incidence in Greek adults without previous CVD.

METHODS

During 2001-2, we enrolled 3042 adults without CVD from the general population of Attica, Greece. In 2011-2, the 10-year study follow-up was performed, recording the CVD incidence in 1958 participants with baseline body mass index (BMI) ≥18.5kg/m².

RESULTS

The study 10-year CVD incidence was 15.8%, exhibiting a gradual increase according to the baseline body mass index (BMI) category. Baseline BMI ≥30kg/m² was related with significantly higher 10-year CVD risk compared to BMI <25kg/m², even after adjustment for age and other known CVD risk factors. Baseline BMI, waist circumference, waist-to-hip ratio, waist-to-height ratio and waist-to-hip-to-height ratio were independently associated with the 10-year CVD risk in multi-adjusted models. Gender-specific analyses showed that these associations were more evident in men compared to women, with baseline BMI exhibiting an independent association with the 10-year CVD incidence in men.

CONCLUSIONS

Our results indicate that even simple anthropometric indices exhibit independent associations with CVD risk in a representative sample of the Greek general population without previous CVD.

Healthy lifestyle impact on breast cancer-specific and all-cause mortality

PURPOSE

While several studies have evaluated the association of combined lifestyle factors on breast cancer-specific mortality, few have included Hispanic women. We constructed a "healthy behavior index" (HBI) and evaluated its associations with mortality in non-Hispanic White (NHW) and Hispanic women diagnosed with breast cancer from the southwestern U.S.

METHODS

Diet and lifestyle questionnaires were analyzed for 837 women diagnosed with invasive breast cancer (1999-2004) in New Mexico as part of the 4-Corners Women's Health Study. An HBI score ranging from 0 to 12 was based on dietary pattern, physical activity, smoking, alcohol consumption, and body size and shape, with increasing scores representing less healthy characteristics. Hazard ratios for mortality over 14 years of follow-up were estimated for HBI quartiles using Cox proportional hazards models adjusting for education and stratified by ethnicity and stage at diagnosis.

RESULTS

A significant increasing trend was observed across HBI quartiles among all women, NHW women, and those diagnosed with localized or regional/distant stage of disease for all-cause (AC) mortality (p-trend = 0.006, 0.002, 0.03, respectively). AC mortality was increased >2-fold for all women and NHW women in HBI Q4 versus Q1 (HR = 2.18, 2.65, respectively). The association was stronger in women with regional/distant than localized stage of disease (HR = 2.62, 1.94, respectively). Associations for Hispanics or breast cancer-specific mortality were not significant.

CONCLUSIONS

These findings indicate the associations between the HBI and AC mortality, which appear to differ by ethnicity and stage at diagnosis. Interventions for breast cancer survivors should address the combination of lifestyle factors on prognosis.

Hypofibrinolysis in diabetes: a therapeutic target for the reduction of cardiovascular risk

An enhanced thrombotic environment and premature atherosclerosis are key factors for the increased cardiovascular risk in diabetes. The occlusive vascular thrombus, formed secondary to interactions between platelets and coagulation proteins, is composed of a skeleton of fibrin fibres with cellular elements embedded in this network. Diabetes is characterised by quantitative and qualitative changes in coagulation proteins, which collectively increase resistance to fibrinolysis, consequently augmenting thrombosis risk. Current long-term therapies to prevent arterial occlusion in diabetes are focussed on anti-platelet agents, a strategy that fails to address the contribution of coagulation proteins to the enhanced thrombotic milieu. Moreover, antiplatelet treatment is associated with bleeding complications, particularly with newer agents and more aggressive combination therapies, questioning the safety of this approach. Therefore, to safely control thrombosis risk in diabetes, an alternative approach is required with the fibrin network representing a credible therapeutic target. In the current review, we address diabetes-specific mechanistic pathways responsible for hypofibrinolysis including the role of clot structure, defects in the fibrinolytic system and increased incorporation of anti-fibrinolytic proteins into the clot. Future anti-thrombotic therapeutic options are discussed with special emphasis on the potential advantages of modulating incorporation of the anti-fibrinolytic proteins into fibrin networks. This latter approach carries theoretical advantages, including specificity for diabetes, ability to target a particular protein with a possible favourable risk of bleeding. The development of alternative treatment strategies to better control residual thrombosis risk in diabetes will help to reduce vascular events, which remain the main cause of mortality in this condition.

Incidence and risk factors for venous thromboembolism following surgical treatment of fractures below the hip: a meta-analysis

Venous thromboembolism (VTE) is a common complication after surgical treatment of fractures, which is associated with significant morbidity and mortality. Identifying the risk factors for VTE is important for preventive strategies to reduce the incidence of VTE. Therefore, we conducted a meta-analysis to evaluate the incidence of VTE and the risk factors influencing the development of VTE in patients who underwent surgery for fractures below the hip. PubMed, Embase, Web of Science, SinoMed (Chinese BioMedical Literature Service System, China) and CNKI (National Knowledge Infrastructure, China) databases were systematically searched to identify cohort or case-control studies that investigated the incidence and risk factors for VTE following surgical treatment of fractures below the hip. VTE risk ratios (RRs) were pooled by use of a fixed-effect model or a random-effect model, depending on the heterogeneity among the included studies. Heterogeneity between the studies was assessed by I² statistics. Twenty-three studies with a total of 191 294 patients who met the inclusion criteria were included in this meta-analysis. Our results demonstrated that age (≥60 years) (RR = 1·85, 95% confidence interval (CI): 1·34, 2·55; P = 0·000), previous VTE(RR = 5·25, 95% CI: 2·77, 9·96; P = 0·000), heart failure (RR = 1·74, 95% CI: 1·34, 2·27; P = 0·000), current smoking status (RR = 1·23, 95% CI: 1·07, 1·41; P = 0·004), hypertension (RR = 1·62, 95% CI: 1·27, 2·06; P = 0·000), hyperlipidaemia (RR = 2·16, 95% CI: 1·79, 2·62; P = 0·000), diabetes mellitus (RR = 1·46, 95% CI: 1·27, 1·68; P = 0·000), obesity (RR = 1·58, 95% CI: 1·35,·1·85; P = 0·000), multiple fractures (RR = 2·14, 95% CI: 1·00, 4·60; P = 0·050), varicose veins (RR = 3·07, 95% CI: 1·12, 8·47; P = 0·030), prolonged operation time (weighted mean differences (WMD) = 1·22, 95% CI: 0·63, 1·81; P = 0·000) and prolonged bed rest time (WMD = 3·12, 95% CI: 2·96, 3·29; P = 0·000) were associated with an increased risk of developing VTE. The other variables, including age (<60 years), previous smoking, immobility, pregnancy, cancer, open fractures and combination with trauma were not identified as significant risk factors for VTE. Almost all the risk factors mentioned above are in line with the known risk factors for VTE following surgery for fractures below the hip. Thus, surgeons should pay close attention to patients with these medical conditions in order to reduce the incidence of VTE following surgical treatment of fractures below the hip.

Protein Biomarkers for Insulin Resistance and Type 2 Diabetes Risk in Two Large Community Cohorts

Insulin resistance (IR) is a precursor of type 2 diabetes (T2D), and improved risk prediction and understanding of the pathogenesis are needed. We used a novel high-throughput 92-protein assay to identify circulating biomarkers for HOMA of IR in two cohorts of community residents without diabetes (n = 1,367) (mean age 73 ± 3.6 years). Adjusted linear regression identified cathepsin D and confirmed six proteins (leptin, renin, interleukin-1 receptor antagonist [IL-1ra], hepatocyte growth factor, fatty acid-binding protein 4, and tissue plasminogen activator [t-PA]) as IR biomarkers. Mendelian randomization analysis indicated a positive causal effect of IR on t-PA concentrations. Two biomarkers, IL-1ra (hazard ratio [HR] 1.28, 95% CI 1.03-1.59) and t-PA (HR 1.30, 1.02-1.65) were associated with incident T2D, and t-PA predicted 5-year transition to hyperglycemia (odds ratio 1.30, 95% CI 1.02-1.65). Additional adjustment for fasting glucose rendered both coefficients insignificant and revealed an association between renin and T2D (HR 0.79, 0.62-0.99). LASSO regression suggested a risk model including IL-1ra, t-PA, and the Framingham Offspring Study T2D score, but prediction improvement was nonsignificant (difference in C-index 0.02, 95% CI -0.08 to 0.12) over the T2D score only. In conclusion, proteomic blood profiling indicated cathepsin D as a new IR biomarker and suggested a causal effect of IR on t-PA.

Characterization of Visceral and Subcutaneous Adipose Tissue Transcriptome and Biological Pathways in Pregnant and Non-Pregnant Women: Evidence for Pregnancy-Related Regional-Specific Differences in Adipose Tissue

Objective

The purpose of this study was to compare the transcriptome of visceral and subcutaneous adipose tissues between pregnant and non-pregnant women.

Study Design

The transcriptome of paired visceral and abdominal subcutaneous adipose tissues from pregnant women at term and matched non-pregnant women (n = 11) was profiled with the Affymetrix Human Exon 1.0 ST array. Differential expression of selected genes was validated with the use of quantitative reverse transcription–polymerase chain reaction.

Results

Six hundred forty-four transcripts from 633 known genes were differentially expressed (false discovery rate (FDR) <0.1; fold-change >1.5), while 42 exons from 36 genes showed differential usage (difference in FIRMA scores >2 and FDR<0.1) between the visceral and subcutaneous fat of pregnant women. Fifty-six known genes were differentially expressed between pregnant and non-pregnant subcutaneous fat and three genes in the visceral fat. Enriched biological processes in the subcutaneous adipose tissue of pregnant women were mostly related to inflammation.

Conclusion

The transcriptome of visceral and subcutaneous fat depots reveals pregnancy-related gene expression and splicing differences in both visceral and subcutaneous adipose tissue. Furthermore, for the first time, alternative splicing in adipose tissue has been associated with regional differences and human parturition.

Recombinant Human Plasminogen Activator Inhibitor-1 Promotes Cementogenic Differentiation of Human Periodontal Ligament Stem Cells

The periodontium, consisting of gingiva, periodontal ligament (PDL), cementum, and alveolar bone, is necessary for the maintenance of tooth function. Specifically, the regenerative abilities of cementum with inserted PDL are important for the prevention of tooth loss. Periodontal ligament stem cells (PDLSCs), which are located in the connective tissue PDL between the cementum and alveolar bone, are an attractive candidate for hard tissue formation. We investigated the effects of recombinant human plasminogen activator inhibitor-1 (rhPAI-1) on cementogenic differentiation of human PDLSCs (hPDLSCs) in vitro and in vivo. Untreated and rhPAI-1-treated hPDLSCs mixed with hydroxyapatite/tricalcium phosphate (HA/TCP) and dentin matrix were transplanted subcutaneously into the dorsal surface of immunocompromised mice to assess their capacity for hard tissue formation at 8 and 10 weeks posttransplantation. rhPAI-1 accelerated mineral nodule formation and increased the mRNA expression of cementoblast-associated markers in hPDLSCs. We also observed that rhPAI-1 upregulated the levels of osterix (OSX) and cementum protein 1 (CEMP1) through Smad2/3 and p38 pathways, whereas specific inhibitors of Smad3 and p38 inhibited the enhancement of mineralization of hPDLSCs by rhPAI-1. Furthermore, transplantation of hPDLSCs with rhPAI-1 showed a great ability to promote cementogenic differentiation. Notably, rhPAI-1 induced hPDLSCs to regenerate cementum-like tissue with PDL fibers inserted into newly formed cementum-like tissue. These results suggest that rhPAI-1 may play a key role in cementogenic differentiation of hPDLSCs. rhPAI-1 with hPDLSCs may be a good candidate for future clinical applications in periodontal tissue regeneration and possibly in tooth root bioengineering.

Risk factors for venous thromboembolism after total hip and total knee arthroplasty: a meta-analysis

INTRODUCTION

Venous thromboembolism (VTE) is a common complication after total hip arthroplasty (THA) or total knee arthroplasty (TKA) and may be the cause for a secondary PE and associated morbidity/mortality. We performed a systematic literature review of risk factors and risk reduction of VTE after THA or TKA.

MATERIALS AND METHODS

A systematic search of PubMed database, the Cochrane Library, OVID MEDLINE and American Academy of Orthopaedic Surgeons (AAOS), without restriction of publication data and language, was conducted. We performed a meta-analysis of ten factors for VTE after THA or TKA. Four authors independently assessed data extraction and quality of the studies using the Newcastle-Ottawa Scale (NOS) as quality assessment tool. Assessment of heterogeneity and analysis of data were operated by Review Manager 5.2.9.

RESULTS

Fourteen retrospective case-control or prospective cohort studies, which included 18,075 patients who developed VTE after THA or TKA of a total of 1,723,350 cases, were selected. Our results demonstrated that, among all ten factors investigated, 3 main risk factors were significantly associated with VTE after THA or TKA: history of VTE (RR > 10.6), varicose vein (RR > 2.7) and congestive cardiac failure (RR 2). There was also an increase of VTE risk ranging from 8 to 30 % for female gender < age (≥80) < hypertension < (active) cancer < obesity (BMI ≥ 30) < (black) race. Data analysis revealed that diabetes mellitus had no significant relationship with VTE after THA or TKA.

CONCLUSIONS

This study highlighted the role of nine significant risk factors in the development of VTE after THA or TKA. Among all risk factors, history of VTE seems the one main indication for more potent anticoagulation. All other risk factors need to be considered and discussed with patients individually and balanced against the risk of bleeding and infection. Individual patient risk assessment, rather than a "blanket policy", is considered the best management strategy before deciding on the type of chemical prophylaxis.

Predisposing factors to post-operative adhesion development

BACKGROUND

Adhesion development is the most common sequelae of intra-abdominal and pelvic surgery and represents a significant, yet poorly understood, cause of morbidity among post-operative patients. It remains unclear, for example, exactly why adhesions form more frequently in certain tissues and/or patients, or at specific locations within them, as opposed to others. This review contributes to the growing knowledge pool by elucidating factors that potentially predispose to the development of adhesions. Given the strong correlation between a hypofibrinolytic state and adhesion formation, this review article will examine not only those factors that have been shown to directly predispose to adhesion development, but also those that are likely do so indirectly by means of altering the coagulation/fibrinolytic profile.

METHODS

A literature search was performed using the PubMed database for all relevant English language articles up to February 2014. All of the identified articles were reviewed with particular attention to predisposing factors to post-operative adhesion development. In addition, the reference lists of each article were reviewed to identify additional relevant articles.

RESULTS

Various factors have been shown to directly increase the risk of post-operative adhesion development; namely, certain genetic polymorphisms in the interleukin-1 receptor antagonist, increased estrogen exposure, and endometriosis. In addition, numerous factors are known to increase the risk of fibrosis, therefore likely increasing the risk of adhesion development indirectly. These factors include genetic polymorphisms in plasminogen activator inhibitor-1 and thrombin-activatable fibrinolysis inhibitor, diabetes mellitus, metabolic syndrome, hyperglycemia, obesity, depression, binge alcohol consumption, anti-Parkinsonian medications, oral hormone therapy, pregnancy, and cancer.

CONCLUSIONS

The literature reviewed in this paper will help to direct future research aimed at understanding the mechanisms that underlie the association of certain factors with adhesion development. This information will be crucial in the creation of adequate preventative and treatment strategies.

Development of a murine model of early sepsis in diet-induced obesity

Sepsis, a global health issue, is the most common cause of mortality in the intensive care unit. The aim of this study was to develop a new model of sepsis that investigates the impact of prolonged western diet (WD) induced obesity on the response to early sepsis. Male C57BL/6 mice were fed either a high fat WD or normal chow diet (NCD) for 6, 15, or 27 weeks. Septic obese mice at 15 and 27 weeks had significantly lower levels of lung myeloperoxidase (26.3 ± 3.80 U/mg tissue) compared to age matched ad lib (44.1 ± 2.86 U/mg tissue) and diet restricted (63.2 ± 5.60 U/mg tissue) controls. Low levels of lung inflammation were not associated with changes in hepatic cytokines and oxidative stress levels. Obese mice had significantly (P < 0.0001) larger livers compared to controls. Histological examination of the livers demonstrated that WD fed mice had increased inflammation with pronounced fat infiltration, steatosis, and hepatocyte ballooning. Using this model of prolonged exposure to high fat diet we have data that agree with recent clinical observations suggesting obese individuals are protected from sepsis-induced lung injury. This model will allow us to investigate the links between damage to the hepatic microcirculation, immune response, and lung injury.

Type 1 plasminogen activator inhibitor as a common risk factor for cancer and ischaemic vascular disease: the EPICOR study

OBJECTIVES

We examined the association of plasminogen activator inhibitor-1 (PAI-1) levels with colorectal cancer, breast cancer, acute coronary syndrome (ACS) and ischaemic stroke.

DESIGN

Nested case-cohort study.

SETTING

The European Prospective Investigation into Cancer and Nutrition-Italy cohort.

PARTICIPANTS

A centre-stratified random sample of 850 participants (286 men, 564 women) was selected as subcohort and compared with 303 colorectal cancers, 617 breast cancers, 688 ACS and 158 ischaemic strokes, in a mean follow-up of 9.11 years.

MAIN OUTCOMES AND MEASURES

Primary incident cases of colon cancer, breast cancer, ACS and ischaemic stroke. PAI-1 levels were measured in citrated plasma by ELISA. HR and 95% CI, adjusted by relevant confounders and stratified by centre, were estimated by a Cox regression model using Prentice method.

RESULTS

Individuals in the highest compared with the lowest quartile of PAI-1 had significantly increased risk of colorectal cancer (RR=2.28; 95% CI 1.46 to 3.55; P for trend<0.0012), breast cancer (HR=1.70; 95% CI 1.21 to 2.39; p<0.0055), ACS (HR=2.57; 95% CI 1.75 to 3.77; p<0.001) and ischaemic stroke (HR=2.27; 95% CI 1.28 to 4.03; p<0.0017), after adjustment for sex and age. Additional adjustment for disease-specific confounders, insulin or other metabolic variables did not modify the associations. Risk of colon cancer was stronger for men and for whole and distal colon localisation. Risk for breast cancer was stronger in postmenopausal women.

CONCLUSIONS

Our data provide the first evidence that elevated levels of PAI-1 are potential risk factors for colorectal and breast cancer and a common pathway for cancer and cardiovascular disease.

Developmental programming of fetal skeletal muscle and adipose tissue development

All important developmental milestones are accomplished during the fetal stage, and nutrient fluctuation during this stage produces lasting effects on offspring health, so called fetal programming or developmental programming. The fetal stage is critical for skeletal muscle development, as well as adipose and connective tissue development. Maternal under-nutrition at this stage affects the proliferation of myogenic precursor cells and reduces the number of muscle fibers formed. Maternal over-nutrition results in impaired myogenesis and elevated adipogenesis. Because myocytes, adipocytes and fibrocytes are all derived from mesenchymal stem cells, molecular events which regulate the commitment of stem cells to different lineages directly impact fetal muscle and adipose tissue development. Recent studies indicate that microRNA is intensively involved in myogenic and adipogenic differentiation from mesenchymal stem cells, and epigenetic changes such as DNA methylation are expected to alter cell lineage commitment during fetal muscle and adipose tissue development.

Diet-induced obesity has a differential effect on adipose tissue and macrophage inflammatory responses of young and old mice

Obesity and aging are both associated with increased inflammation in adipose tissue. In this study, we investigated effect of diet-induced obesity on inflammatory status in young and old mice. Young (2 months) and old (19 months) C57BL/6 mice were fed a low-fat (10%, LF) or high-fat (60%, HF) diet for 4.5 months. Adipose tissue from old/LF mice expressed higher levels of IL-1β, IL-6, TNFα, and cyclooxygenase-2 mRNA compared with young/LF mice. HF diet upregulated expression of all these inflammatory markers in young mice to the levels seen in the aged. Adipocytes, but not stromal vascular cells, from old/LF mice produced more IL-6, TNFα, and prostaglandin (PG)E2 than those from young/LF mice. HF diet resulted in an increase of all these markers produced by adipocytes in young, but only TNFα in old mice. PGE2 produced by peritoneal macrophages (Mϕ's) was upregulated with aging, and HF diet induced more IL-6, TNFα, and PGE2 production in young but not in old mice. Thus, HF diet/obesity induces an inflammatory state in both visceral fat cells and peritoneal Mϕ's of young mice, but not so in old mice. Together, these results suggest that HF diet-induced obesity may speed up the aging process as characterized by inflammatory status. This study also indicates that animals have a differential response, depending on their ages, to HF diet-induced obesity and inflammation. This age-related difference in response to HF diet should be considered when using inflammation status as a marker in investigating adverse health impacts of HF diet and obesity.

Acute coronary syndrome in patients with diabetes mellitus: perspectives of an interventional cardiologist

Diabetes mellitus (DM) is well known to be a coronary artery disease risk equivalent but the cellular mechanism is not completely understood. Recently, virtual histology intravascular ultrasound has demonstrated that patients with DM tend to have a higher occurrence of vulnerable plaques as compared with patients without DM. Insulin-sensitizing agents, such as metformin, have been shown to have limited cardioprotective effects, whereas thiazolidinediones, such as rosiglitazone, have been reported to have possible deleterious effects on cardiovascular mortality in a meta-analysis; however, limited data exist. In contrast, pioglitazone has been reported to have a significant benefit in patients with type 2 DM with acute coronary syndrome (ACS). Animal and human studies have demonstrated the myocardial protective effects of incretins and hold promise in reducing the incidence of major adverse cardiac events in patients with DM. Moreover, in addition to aspirin, the early use of potent antiplatelet agents, such as prasugrel and intravenous glycoprotein IIb-IIIa inhibitors, in patients with DM presenting with ACS is crucial for reducing cardiovascular events in most patients. Thus, patients with DM deserve special attention in global risk factor reduction and development of newer therapeutic agents to improve glycemic control while minimizing or reducing cardiovascular events. This article focuses on ACS in patients with DM, the pathophysiology of "vulnerable blood" in patients with DM, and newer treatment strategies to improve outcomes in this high-risk patient population.

Meat Science and Muscle Biology Symposium: manipulating mesenchymal progenitor cell differentiation to optimize performance and carcass value of beef cattle

Beef cattle are raised for their lean tissue, and excessive fat accumulation accounts for large amounts of waste. On the other hand, intramuscular fat or marbling is essential for the palatability of beef. In addition, tender beef is demanded by consumers, and connective tissue contributes to the background toughness of beef. Recent studies show that myocytes, adipocytes, and fibroblasts are all derived from a common pool of progenitor cells during embryonic development. It appears that during early embryogenesis, multipotent mesenchymal stem cells first diverge into either myogenic or adipogenic-fibrogenic lineages; myogenic progenitor cells further develop into muscle fibers and satellite cells whereas adipogenic-fibrogenic lineage cells develop into the stromal-vascular fraction of skeletal muscle where reside adipocytes, fibroblasts, and resident fibro-adipogenic progenitor cells (the counterpart of satellite cells). Strengthening myogenesis (i.e., formation of muscle cells) enhances lean growth, promoting intramuscular adipogenesis (i.e., formation of fat cells) increases marbling, and reducing intramuscular fibrogenesis (i.e., formation of fibroblasts and synthesis of connective tissue) improves overall tenderness of beef. Because the abundance of progenitor cells declines as animals age, it is more effective to manipulate progenitor cell differentiation at an early developmental stage. Nutritional, environmental, and genetic factors shape progenitor cell differentiation; however, up to now, our knowledge regarding mechanisms governing progenitor cell differentiation remains rudimentary. In summary, altering mesenchymal progenitor cell differentiation through nutritional management of cows, or fetal programming, is a promising method to improve cattle performance and carcass value.

Biology of metabolic syndrome in a vascular patient

Metabolic syndrome is highly prevalent in vascular patients and has a significant impact on the outcomes of vascular interventions. It comprises of a set of metabolically driven risk factors, including truncal obesity, dyslipidemia, elevated blood pressure and elevated fasting blood glucose. Increased insulin resistance within the context of obesity and hypertension contributes to atherogenic dyslipidemia, hyperglycemia, and prothrombotic and proinflammatory states which lead to the adverse impact of metabolic syndrome on the response to injury and on atherosclerotic disease progression. This review focuses on the complex biology of metabolic syndrome and its relevance to management of vascular patients, including outcomes and implications for the coronary, cerebrovascular and lower-extremity vascular beds.

Vascular biology of metabolic syndrome

The metabolic syndrome is a constellation of clinical risk factors comprising atherogenic dyslipidemia (low high-density lipoprotein and high triglycerides levels), elevated blood pressure, elevated plasma glucose, a prothrombotic state, and a proinflammatory state accompanied by an increased risk for cardiovascular disease and type 2 diabetes mellitus. The adipose tissue of obese humans contains increased numbers of macrophages, and once activated, these macrophages are responsible for the expression of most of the tissue's tumor necrosis factor (TNF)-α and interleukin (IL)-6. Chronic inflammation associated with visceral obesity induces altered lipoprotein metabolism and insulin resistance in the liver. Adipocytes secrete a variety of hormones, cytokines, growth factors, and other bioactive substances, conceptualized as adipocytokines, including plasminogen activator inhibitor 1 (PAI-1), TNF-α, leptin, and adiponectin. The dysregulation of these adipokines contributes to the pathogenesis of obesity. Adipose tissue-resident macrophages and adipocytes in the adipose tissue combined with the consequences of hyperglycemia, altered lipoproteins, and hyperinsulinemia in the vasculature and within organ microcirculation lead to dysfunctional endothelia and a proinflammatory state. Metabolic syndrome thus represents a combination of synergistic vascular pathologies that lead to an accelerated atherogenic state that compromises the ability of the patient to satisfactorily respond to humoral, cellular, and mechanical stresses.

Effects of specific chemical suppressors of plasminogen activator inhibitor-1 in cardiovascular diseases

INTRODUCTION

plasminogen activator inhibitor-1 (PAI-1) is critical in thrombus formation and inflammation. Although these are essential pathological features of cardiovascular diseases, the effects of PAI-1 inhibition against the development of cardiovascular remodeling have not been well studied.

AREAS COVERED

the review explores the therapeutic value of PAI-1 in the progression of various cardiovascular diseases. To date, the authors have reported that a novel PAI-1 inhibitor suppressed the development of experimental autoimmune myocarditis, vascular remodeling after arterial injury, and heart transplant rejection using rodent models. Pathologically, the PAI-1 inhibitor improved histological remodeling of myocardium and arteries with suppression of inflammation and thrombus formation.

EXPERT OPINION

PAI-1 inhibitors appear to exhibit potent effects on the prevention of adverse tissue remodeling. However, PAI-1 is a multifunctional protein and more research is needed to further elucidate the association between PAI-1 expression and cardiovascular disease.

Differential white blood cell count and type 2 diabetes: systematic review and meta-analysis of cross-sectional and prospective studies

OBJECTIVE

Biological evidence suggests that inflammation might induce type 2 diabetes (T2D), and epidemiological studies have shown an association between higher white blood cell count (WBC) and T2D. However, the association has not been systematically investigated.

RESEARCH DESIGN AND METHODS

Studies were identified through computer-based and manual searches. Previously unreported studies were sought through correspondence. 20 studies were identified (8,647 T2D cases and 85,040 non-cases). Estimates of the association of WBC with T2D were combined using random effects meta-analysis; sources of heterogeneity as well as presence of publication bias were explored.

RESULTS

The combined relative risk (RR) comparing the top to bottom tertile of the WBC count was 1.61 (95% CI: 1.45; 1.79, p = 1.5*10(-18)). Substantial heterogeneity was present (I(2) = 83%). For granulocytes the RR was 1.38 (95% CI: 1.17; 1.64, p = 1.5*10(-4)), for lymphocytes 1.26 (95% CI: 1.02; 1.56, p = 0.029), and for monocytes 0.93 (95% CI: 0.68; 1.28, p = 0.67) comparing top to bottom tertile. In cross-sectional studies, RR was 1.74 (95% CI: 1.49; 2.02, p = 7.7*10(-13)), while in cohort studies it was 1.48 (95% CI: 1.22; 1.79, p = 7.7*10(-5)). We assessed the impact of confounding in EPIC-Norfolk study and found that the age and sex adjusted HR of 2.19 (95% CI: 1.74; 2.75) was attenuated to 1.82 (95% CI: 1.45; 2.29) after further accounting for smoking, T2D family history, physical activity, education, BMI and waist circumference.

CONCLUSIONS

A raised WBC is associated with higher risk of T2D. The presence of publication bias and failure to control for all potential confounders in all studies means the observed association is likely an overestimate.

HDL3, but not HDL2, stimulates plasminogen activator inhibitor-1 release from adipocytes: the role of sphingosine-1-phosphate

Sphingosine-1-phosphate (S1P) is a bioactive lysophospholipid that regulates numerous key cardiovascular functions. High-density lipoproteins (HDLs) are the major plasma lipoprotein carriers of S1P. Fibrinolysis is a physiological process that allows fibrin clot dissolution, and decreased fibrinolytic capacity may result from increased circulating levels of plasminogen activator inhibitor-1 (PAI-1). We examined the effect of S1P associated with HDL subfractions on PAI-1 secretion from 3T3 adipocytes. S1P concentration in HDL3 averaged twice that in HDL2. Incubation of adipocytes with increasing concentrations of S1P in HDL3, but not HDL2, or with S1P complexed to albumin stimulated PAI-I secretion in a concentration-dependent manner. Quantitative RT-PCR revealed that S1P(1-3) are expressed in 3T3 adipocytes, with S1P(2) expressed in the greatest amount. Treatment of adipocytes with the S1P(1) and S1P(3) antagonist VPC23019 did not block PAI-1 secretion. Inhibiting S1P(2) with JTE-013 or reducing the expression of the gene coding for S1P(2) using silencing RNA (siRNA) technology blocked PAI-1 secretion, suggesting that the S1P(2) receptor mediates PAI-1 secretion from adipocytes exposed to HDL3 or S1P. Treatment with the phospholipase C (PLC) inhibitor U73122, the protein kinase C (PKC) inhibitor RO-318425, or the Rho-associated protein kinase (ROCK) inhibitor Y27632 all significantly inhibited HDL3- and S1P-mediated PAI-1 release, suggesting that HDL3- and/or S1P-stimulated PAI-1 secretion from 3T3 cells is mediated by activation of multiple, downstream signaling pathways of S1P(2).

Glucose supply and insulin demand dynamics of antidiabetic agents

BACKGROUND

For microvascular outcomes, there is compelling historical and contemporary evidence for intensive blood glucose reduction in patients with either type 1 diabetes mellitus (T1DM) or type 2 diabetes mellitus (T2DM). There is also strong evidence to support macrovascular benefit with intensive blood glucose reduction in T1DM. Similar evidence remains elusive for T2DM. Because cardiovascular outcome trials utilizing conventional algorithms to attain intensive blood glucose reduction have not demonstrated superiority to less aggressive blood glucose reduction (Action to Control Cardiovascular Risk in Diabetes; Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified Release Controlled Evaluation; and Veterans Affairs Diabetes Trial), it should be considered that the means by which the blood glucose is reduced may be as important as the actual blood glucose.

METHODS

By identifying quantitative differences between antidiabetic agents on carbohydrate exposure (CE), hepatic glucose uptake (HGU), hepatic gluconeogenesis (GNG), insulin resistance (IR), peripheral glucose uptake (PGU), and peripheral insulin exposure (PIE), we created a pharmacokinetic/pharmacodynamic model to characterize the effect of the agents on the glucose supply and insulin demand dynamic. Glucose supply was defined as the cumulative percentage decrease in CE, increase in HGU, decrease in GNG, and decrease in IR, while insulin demand was defined as the cumulative percentage increase in PIE and PGU. With the glucose supply and insulin demand effects of each antidiabetic agent summated, the glucose supply (numerator) was divided by the insulin demand (denominator) to create a value representative of the glucose supply and insulin demand dynamic (SD ratio).

RESULTS

Alpha-glucosidase inhibitors (1.25), metformin (2.20), and thiazolidinediones (TZDs; 1.25-1.32) demonstrate a greater effect on glucose supply (SD ratio >1), while secretagogues (0.69-0.81), basal insulins (0.77-0.79), and bolus insulins (0.62-0.67) demonstrate a greater effect on insulin demand (SD ratio <1).

CONCLUSION

Alpha-glucosidase inhibitors, metformin, and TZDs demonstrate a greater effect on glucose supply, while secretagogues, basal insulin, and bolus insulin demonstrate a greater effect on insulin demand. Because T2DM cardiovascular outcome trials have not demonstrated macrovascular benefit with more aggressive blood glucose reduction when using conventional algorithms that predominantly focus on insulin demand, it would appear logical to consider a model that incorporates both the extent of blood glucose lowering (hemoglobin A1c) and the means by which the blood glucose was reduced (SD ratio) when considering macrovascular outcomes.

Plasminogen activator inhibitor-1 is an aggregate response factor with pleiotropic effects on cell signaling in vascular disease and the tumor microenvironment

In hemostasis, the serine protease inhibitor (serpin) plasminogen activator inhibitor-1 (PAI-1) functions to stabilize clots via inhibition of tissue plasminogen activator (tPA) with subsequent inhibition of fibrinolysis. In tissues, PAI-1 functions to inhibit extracellular matrix degradation via inhibition of urokinase plasminogen activator (uPA). Elevated levels of PAI-1 in the vasculature and in tissues have long been known to be associated with thrombosis and fibrosis, respectively. However, there is emerging evidence that PAI-1 may participate in the pathophysiology of a number of diseases such as atherosclerosis, restenosis, and cancer. In many of these disease states, the canonical view of PAI-1 as an inhibitor of tPA and uPA cannot fully account for a mechanism whereby PAI-1 contributes to the disease. In these cases, one must consider recent data, which indicates PAI-1 can directly promote pro-proliferative and anti-apoptotic signaling in a variety of cell types. Given the wide variety of inflammatory, hormonal, and metabolic signals that increase PAI-1 expression, it is important to consider mechanisms by which PAI-1 can directly participate in disease etiology.

Dysregulation of maternal serum adiponectin in preterm labor

OBJECTIVE

Intra-amniotic and systemic infection/inflammation have been causally linked to preterm parturition and fetal injury. An emerging theme is that adipose tissue can orchestrate a metabolic response to insults, but also an inflammatory response via the production of adipocytokines, and that these two phenomenons are interrelated. Adiponectin, an insulin-sensitising, anti-inflammatory adipocytokine, circulates in multimeric complexes including low-molecular weight (LMW) trimers, medium-molecular weight (MMW) hexamers and high-molecular weight (HMW) isoforms. Each of these complexes can exert differential biological effects. The aim of this study was to determine whether spontaneous preterm labor (PTL) with intact membranes and intra-amniotic infection/inflammation (IAI) is associated with changes in maternal serum circulating adiponectin multimers.

STUDY DESIGN

This cross-sectional study included patients in the following groups: (1) normal pregnant women (n=158); (2) patients with an episode of preterm labor and intact membranes without IAI who delivered at term (n=41); (3) preterm labor without IAI who delivered preterm (n=27); and (4) preterm labor with IAI who delivered preterm (n=36). Serum adiponectin multimers (total, HMW, MMW and LMW) concentrations were determined by ELISA. Non-parametric statistics were used for analyses.

RESULTS

(1) Preterm labor leading to preterm delivery or an episode of preterm labor that does not lead to preterm delivery was associated with a lower median maternal serum concentration of total and HMW adiponectin, a lower median HMW/total adiponectin ratio and a higher median LMW/total adiponectin ratio than normal pregnancy; (2) among patients with preterm labor, those with IAI had the lowest median concentration of total and HMW adiponectin, as well as the lowest median HMW/total adiponectin ratio; (3) the changes in maternal adiponectin and adiponectin multimers remained significant after adjusting for confounding factors such as maternal age, BMI, gestational age at sampling and parity.

CONCLUSION

(1) Preterm labor is characterised by a change in the profile of adiponectin multimers concentrations and their relative isoforms. These changes were observed in patients with an episode of preterm labor not leading to preterm delivery, in patients with intra-amniotic inflammation, or in those without evidence of intra-amniotic inflammation. (2) The changes in adiponectin multimer concentrations reported in preterm labor are different from those previously reported in spontaneous labor at term, suggesting that there is a fundamental difference between preterm labor and labor at term. (3) The findings reported herein provide the first evidence for the participation of adiponectin multimer in preterm parturition. We propose that adiponectins and adipokines in general provide a mechanism to organise the metabolic demands generated by the process of preterm parturition regardless of the nature of the insult (intra-amniotic inflammation or not).

Reduced adiposity and high-fat diet-induced adipose inflammation in mice deficient for phosphodiesterase 4B

The concept that obesity is an inflammatory state has changed our understanding of this condition and suggested that pharmacological interventions targeting inflammation may be useful strategies to improve metabolic complications of obesity. Phosphodiesterase 4 (PDE4) inhibitors exhibit profound antiinflammatory effects, but whether PDE4 inhibition suppresses obesity-induced inflammation is unknown. Among PDE4 isoforms, PDE4B is the major species mediating inflammatory responses. We therefore examined obesity-related phenotypes in mice deficient for PDE4B. Compared with wild-type littermates, PDE4B-null mice were leaner, with lower fat pad weights, smaller adipocytes, and decreased serum leptin levels on both chow and high-fat diets (HFDs). PDE4B deficiency suppressed TNF-alpha mRNA levels and macrophage infiltration in white adipose tissue in mice on HFD, but insulin sensitivity was unaltered. PDE4B-null mice on HFDs had increased locomotor activity. These results suggest a previously unappreciated role for PDE4B in the regulation of energy balance and that PDE4B inhibitors could have utility in treatment of obesity and for suppression of obesity-induced inflammation in white adipose tissue.