Metformin is the most commonly prescribed medication for type 2 diabetes, owing to its glucose-lowering effects, which are mediated through the suppression of hepatic glucose production (reviewed in refs. 1-3). However, in addition to its effects on the liver, metformin reduces appetite and in preclinical models exerts beneficial effects on ageing and a number of diverse diseases (for example, cognitive disorders, cancer, cardiovascular disease) through mechanisms that are not fully understood 1-3. Given the high concentration of metformin in the liver and its many beneficial effects beyond glycemic control, we reasoned that metformin may increase the secretion of a hepatocyte-derived endocrine factor that communicates with the central nervous system 4. Here we show, using unbiased transcriptomics of mouse hepatocytes and analysis of proteins in human serum, that metformin induces expression and secretion of growth differentiating factor 15 (GDF15). In primary mouse hepatocytes, metformin stimulates the secretion of GDF15 by increasing the expression of activating transcription factor 4 (ATF4) and C/EBP homologous protein (CHOP; also known as DDIT3). In wild-type mice fed a high-fat diet, oral administration of metformin increases serum GDF15 and reduces food intake, body mass, fasting insulin and glucose intolerance; these effects are eliminated in GDF15 null mice. An increase in serum GDF15 is also associated with weight loss in patients with type 2 diabetes who take metformin. Although further studies will be required to determine the tissue source(s) of GDF15 produced in response to metformin in vivo, our data indicate that the therapeutic benefits of metformin on appetite, body mass and serum insulin depend on GDF15. Metformin is one of the most widely used medications in the world. It is a strong base that exists in its protonated form at physiological pH and therefore does not pass through cellular membranes easily. In rodents, oral administration of metformin (250-300 mg kg-1 body weight) results in clinically relevant plasma concentrations of approximately 10-15 μM; however, concentrations in the

Here we evaluated the performance of a large set of serum biomarkers for the prediction of rapid progression of chronic kidney disease (CKD) in patients with type 2 diabetes. We used a case-control design nested within a prospective cohort of patients with baseline eGFR 30-60 ml/min per 1.73 m(2). Within a 3.5-year period of Go-DARTS study patients, 154 had over a 40% eGFR decline and 153 controls maintained over 95% of baseline eGFR. A total of 207 serum biomarkers were measured and logistic regression was used with forward selection to choose a subset that were maximized on top of clinical variables including age, gender, hemoglobin A1c, eGFR, and albuminuria. Nested cross-validation determined the best number of biomarkers to retain and evaluate for predictive performance. Ultimately, 30 biomarkers showed significant associations with rapid progression and adjusted for clinical characteristics. A panel of 14 biomarkers increased the area under the ROC curve from 0.706 (clinical data alone) to 0.868. Biomarkers selected included fibroblast growth factor-21, the symmetric to asymmetric dimethylarginine ratio, β2-microglobulin, C16-acylcarnitine, and kidney injury molecule-1. Use of more extensive clinical data including prebaseline eGFR slope improved prediction but to a lesser extent than biomarkers (area under the ROC curve of 0.793). Thus we identified several novel associations of biomarkers with CKD progression and the utility of a small panel of biomarkers to improve prediction.

Background: Alirocumab, an antibody that blocks PCSK9 (proprotein convertase subtilisin/kexin type 9), was associated with reduced major adverse cardiovascular events (MACE) and death in the ODYSSEY OUTCOMES trial (Evaluation of Cardiovascular Outcomes After an Acute Coronary Syndrome During Treatment With Alirocumab). In this study, higher baseline levels of low-density lipoprotein cholesterol (LDL-C) predicted greater benefit from alirocumab treatment. Recent studies indicate high polygenic risk scores (PRS) for coronary artery disease (CAD) identify individuals at higher risk who derive increased benefit from statins. We performed post hoc analyses to determine whether high PRS for CAD identifies higher-risk individuals, independent of baseline LDL-C and other known risk factors, who might derive greater benefit from alirocumab treatment. Methods: ODYSSEY OUTCOMES was a randomized, double-blind, placebo-controlled trial comparing alirocumab or placebo in 18 924 patients with acute coronary syndrome and elevated atherogenic lipoproteins despite optimized statin treatment. The primary endpoint (MACE) comprised death of CAD, nonfatal myocardial infarction, ischemic stroke, or unstable angina requiring hospitalization. A genome-wide PRS for CAD comprising 6 579 025 genetic variants was evaluated in 11 953 patients with available DNA samples. Analysis of MACE risk was performed in placebo-treated patients, whereas treatment benefit analysis was performed in all patients. Results: The incidence of MACE in the placebo group was related to PRS for CAD: 17.0% for high PRS patients (>90th percentile) and 11.4% for lower PRS patients (≤90th percentile; P <0.001); this PRS relationship was not explained by baseline LDL-C or other established risk factors. Both the absolute and relative reduction of MACE by alirocumab compared with placebo was greater in high versus low PRS patients. There was an absolute reduction by alirocumab in high versus low PRS groups of 6.0% and 1.5%, respectively, and a relative risk reduction by alirocumab of 37% in the high PRS group (hazard ratio, 0.63 [95% CI, 0.46–0.86]; P =0.004) versus a 13% reduction in the low PRS group (hazard ratio, 0.87 [95% CI, 0.78–0.98]; P =0.022; interaction P =0.04). Conclusions: A high PRS for CAD is associated with elevated risk for recurrent MACE after acute coronary syndrome and a larger absolute and relative risk reduction with alirocumab treatment, providing an independent tool for risk stratification and precision medicine.

Omi/HtrA2 is a mammalian serine protease with high homology to bacterial HtrA chaperones. Omi/HtrA2 is localized in mitochondria and is released to the cytoplasm in response to apoptotic stimuli. Omi/HtrA2 induces cell death in a caspase-dependent manner by interacting with the inhibitor of apoptosis protein as well as in a caspase-independent manner that relies on its protease activity. We describe the identification and characterization of a novel compound as a specific inhibitor of the proteolytic activity of Omi/HtrA2. This compound (ucf-101) was isolated in a high throughput screening of a combinatorial library using bacterially made Omi-(134 -458) protease and fluorescein-casein as a generic substrate. ucf-101 showed specific activity against Omi/HtrA2 and very little activity against various other serine proteases. This compound has a natural fluorescence that was used to monitor its ability to enter mammalian cells. ucf-101, when tested in caspase-9 (؊/؊) null fibroblasts, was found to inhibit Omi/HtrA2-induced cell death.

OBJECTIVEMetformin is a commonly used glucose-lowering drug. However, apart from glycemic measures, no biomarker for its presence or dose has been identified. RESEARCH DESIGN AND METHODSA total of 237 biomarkers were assayed in baseline serum from 8,401 participants (2,317 receiving metformin) in the Outcome Reduction with Initial Glargine Intervention (ORIGIN) trial. Regression models were used to identify biomarkers for metformin use. RESULTSGrowth differentiation factor 15 (GDF15) was strongly linked to metformin, such that the odds of metformin use per SD increase in level varied from 3.73 (95% CI 3.40, 4.09) to 3.94 (95% CI 3.59, 4.33) depending on the other included variables. For the remaining 25 linked biomarkers, the odds ranged from 0.71 to 1.24. A 1.64 ng/mL higher GDF15 level predicted a 188-mg higher metformin dose (P < 0.0001). CONCLUSIONSGDF15 levels are a biomarker for the use of metformin in people with dysglycemia, and its concentration reflects the dose of metformin.Metformin is currently the most widely used glucose-lowering agent in the world that effectively lowers glucose levels; reduces incident diabetes (1); modestly reduces weight; and may reduce the occurrence of ischemic heart disease, mortality, and some malignancies (2). Whereas its glucometabolic effects are partially due to activation of the AMP-activated protein kinase (3), some of its other effects may be mediated by novel pathways. To identify nonglycemic biomarkers for such pathways, we screened a large panel of 237 markers, covering major physiological pathways that were assayed in baseline serum samples collected in 8,401 participants (;28% of whom were receiving various doses of metformin) in the recently completed Outcome Reduction with Initial Glargine Intervention (ORIGIN) trial. RESEARCH DESIGN AND METHODSThe ORIGIN trial recruited 12,537 people with diabetes, impaired glucose tolerance, or impaired fasting glucose levels who had additional cardiovascular (CV) risk factors (4). Prior to randomization, 8,494 participants (68%) provided baseline blood samples that were spun, separated, aliquoted, frozen (within 2 h of collection), and transported to the Population Health Research Institute Biobank in Hamilton, Ontario, Canada, where they were stored in nitrogen vapor-cooled tanks at 2160°C. A

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Objective-The serine protease MT-SP1/matriptase plays an important role in cell migration and matrix degradation.Hepatocyte growth factor (HGF), urokinase-type plasminogen activator (uPA), and protease-activated receptor 2 (PAR-2) have been identified as in vitro substrates of MT-SP1/matriptase. Because PAR-2 is expressed in endothelial cells and contributes to inflammatory processes, we sought to investigate the effects of MT-SP1/matriptase on endothelial cytokine expression and analyzed MT-SP1/matriptase expression in vascular cells and atherosclerotic lesions. Methods and Results-In endothelial cells, recombinant MT-SP1/matriptase dose-dependently induced interleukin (IL)-8and IL-6 mRNA and protein expression dependent on its proteolytic activity. MT-SP1/matriptase time-dependently induced phosphorylation of p38 MAPK and p42/44 MAPK. Inhibitor experiments revealed that p38 MAPK and PKC␣ were necessary for IL-8 induction. PAR-2 downregulation abolished and PAR-2 overexpression augmented MT-SP1/ matriptase-induced IL-8 expression as evidence for PAR-2 signaling. In human atherectomies, MT-SP1/matriptase was expressed in blood cells adherent to the endothelium. Concordantly, basal MT-SP1/matriptase expression was detected in isolated monocytes. Coincubation of monocytes and endothelial cells resulted in an increased IL-8 release, which was reduced after downregulation of endothelial PAR-2 and monocytic MT-SP1/matriptase. Key Words: pathophysiology Ⅲ growth factors Ⅲ endothelium M T-SP1/matriptase is a trypsin-like, multi-domain serine protease expressed primarily in epithelial cells. [1][2][3][4] Its importance in the biology of surface-lining epithelial cells became apparent in MT-SP1/matriptase knockout mice presenting with a severe deficient epidermal barrier function as well as abnormal hair follicle development and disturbed thymic homeostasis. 5 Moreover, MT-SP1/matriptase is upregulated in different malignant tissues 6 -8 and may be expressed in microvascular endothelial cells. 9 Besides its N-terminal transmembrane signal anchor MT-SP1/matriptase contains two putative regulatory modules: 2 tandem repeats of a CUB domain (C1r/s, Uegf, Bone morphogenetic protein-1) and 4 tandem repeats of a low density lipoprotein (LDL) receptor domain. 1,4 The C-terminal serine protease domain consists of a catalytic triad comprising His-57, In addition to the membrane-anchored form of MT-SP1/matriptase, a soluble form of the protease has been identified lacking the N-terminal 172 amino acids. 1 Shedding from the extracellular surface 11,12 or alternative splicing 3,10 may be the mechanisms leading to the truncated form of MT-SP1/matriptase isolated from human milk. 13 Cleavage within its activation motif generates the 2-chain active protease from a single-chain zymogen. The activation of MT-SP1/matriptase requires its cognate Kunitz-type inhibitor hepatocyte growth factor activator inhibitor (HAI)-1, its noncatalytic domains as well as its serine protease domain. 14 Three macromolecular substrates of MT-SP1/matriptase h...

Aims The association of body weight and weight change with mortality and cardiovascular (CV) outcome in patients with diabetes mellitus (DM) is not clearly established. We assessed the relationship between weight, weight change, and outcomes in patients with established CV risk factors and type 2 DM or pre-diabetes. Methods and results A total of 12 521 participants from the ORIGIN trial were grouped in BMI categories of low body weight [body mass index (BMI) &lt; 22 kg/m2] normal (22–24.9), overweight (25–29.9), obesity Grades 1–3 (30–34.9, 35–39.9, ≥40 kg/m2, respectively). Outcome variables included total and CV mortality and composite outcomes of CV death, non-fatal stroke, or myocardial infarction plus revascularization or heart failure hospitalization. Follow-up was 6.2 years (interquartile range 5.8–6.7 years). After multivariable adjustment, lowest risks were seen in patients with overweight and mild obesity for total mortality [overweight: hazard ratio (HR) 0.80 (95% confidence interval (CI) 0.69–0.91); obesity Grade 1: HR 0.82 (0.71–0.95), both P &lt; 0.01)] and CV mortality [overweight: HR 0.79 (0.66–0.94); obesity Grade 1: 0.79 (0.65–0.95), all compared to patients with normal BMI, P &lt; 0.05]. Obesity of any severity was not associated with higher mortality. Low body weight was related to higher mortality [HR 1.28 (1.02–1.61); CV mortality: HR 1.34 (1.01–1.79), P &lt; 0.05]. A continued 2-year weight loss was associated with higher risk of mortality [HR 1.32 (1.18–1.46), P &lt; 0.0001] and CV mortality [HR 1.18 (1.02–1.35), compared to patients without weight loss, P &lt; 0.05]. In turn, weight gain was not related to any adverse outcome. Conclusion Obesity in patients with DM or pre-diabetes and CV risk profile was not associated with higher mortality or adverse CV outcome. The lowest mortality risk was seen in patients with overweight and moderate obesity (BMI 25–35 kg/m2). Weight loss was an independent risk factor for higher mortality compared to no weight loss.