Insulin resistance in type 1 diabetes: what is ‘double diabetes’ and what are the risks?

In this review, we explore the concept of ‘double diabetes’, a combination of type 1 diabetes with features of insulin resistance and type 2 diabetes. After considering whether double diabetes is a useful concept, we discuss potential mechanisms of increased insulin resistance in type 1 diabetes before examining the extent to which double diabetes might increase the risk of cardiovascular disease (CVD). We then go on to consider the proposal that weight gain from intensive insulin regimens may be associated with increased CV risk factors in some patients with type 1 diabetes, and explore the complex relationships between weight gain, insulin resistance, glycaemic control and CV outcome. Important comparisons and contrasts between type 1 diabetes and type 2 diabetes are highlighted in terms of hepatic fat, fat partitioning and lipid profile, and how these may differ between type 1 diabetic patients with and without double diabetes. In so doing, we hope this work will stimulate much-needed research in this area and an improvement in clinical practice

Disease marker combination enhances patient characterization in the Finnish sarcoidosis patients

Sarcoidosis is an inflammatory disease of unknown etiology and multiple clinical phenotypes. Clinical manifestations range from asymptomatic disease to severe loss-of-function leading to the hypothesis that sarcoidosis might not be just one disease, but consists of several distinct disease entities each with potentially distinct genetic associations. We have previously demonstrated that in our series HLADRB1* 03:01 and haplotype HLA-DRB1*04:01-DPB1*04:01 are associated with good prognosis sarcoidosis. In our recent work, we found a novel SNP (rs9905945) in the 50upstream region of the ACE gene to be associated with favorable disease prognosis as well. The main objective of this study was to expand the previous results and analyse combined influence of the found ACE SNP rs9905945 with the protective HLA markers HLADRB1*03:01 and HLA-DRB1*04:01-DPB1*04:01 in 188 Finnish sarcoidosis patients (resolved disease, n = 90; persistent disease, n = 98). When combining the frequencies of the rs9905945 and of the HLA markers, the strongest association was found for a combination of either/or both HLA markers and rs9905945 for good disease prognosis (37.1% in resolved vs. 11.3% in persistent, p <0.001, OR = 4.61, (95% CI 2.15-9.86)). In conclusion, we discovered that a combination of the ACE SNP rs9905945 and HLA markers enhance the accuracy for predicting disease course in Finnish sarcoidosis patients further characterizing genetic differences between Finnish sarcoidosis patients with different prognosis. (c) 2017 Elsevier Ltd. All rights reserved.Peer reviewe

New insights into aflatoxin B1 mechanistic toxicology in cattle liver: an integrated approach using molecular docking and biological evaluation in CYP1A1 and CYP3A74 knockout BFH12 cell lines

Aflatoxin B1 (AFB1) is a pro-carcinogenic compound bioactivated in the liver by cytochromes P450 (CYPs). In mammals, CYP1A and CYP3A are responsible for AFB1 metabolism, with the formation of the genotoxic carcinogens AFB1-8,9-epoxide and AFM1, and the detoxified metabolite AFQ1. Due to climate change, AFB1 cereals contamination arose in Europe. Thus, cattle, as other farm animals fed with grains (pig, sheep and broiler), are more likely exposed to AFB1 via feed with consequent release of AFM1 in milk, posing a great concern to human health. However, knowledge about bovine CYPs involved in AFB1 metabolism is still scanty. Therefore, CYP1A1- and CYP3A74-mediated molecular mechanisms of AFB1 hepatotoxicity were here dissected. Molecular docking of AFB1 into CYP1A1 model suggested AFB1 8,9-endo- and 8,9-exo-epoxide, and AFM1 formation, while docking of AFB1 into CYP3A74 pointed to AFB1 8,9-exo-epoxide and AFQ1 synthesis. To biologically confirm these predictions, CYP1A1 and CYP3A74 knockout (KO) BFH12 cell lines were exposed to AFB1. LC–MS/MS investigations showed the abolished production of AFM1 in CYP1A1 KO cells and the strong increase of parent AFB1 in CYP3A74 KO cells; the latter result, coupled to a decreased cytotoxicity, suggested the major role of CYP3A74 in AFB1 8,9-exo-epoxide formation. Finally, RNA-sequencing analysis indirectly proved lower AFB1-induced cytotoxic effects in engineered cells versus naïve ones. Overall, this study broadens the knowledge on AFB1 metabolism and hepatotoxicity in cattle, and it provides the weight of evidence that CYP1A1 and CYP3A74 inhibition might be exploited to reduce AFM1 and AFBO synthesis, AFB1 toxicity, and AFM1 milk excretion

Tetrazole as a Replacement of the Electrophilic Group in Characteristic Prolyl Oligopeptidase Inhibitors

4-Phenylbutanoyl-aminoacyl-2(S)-tetrazolylpyrrolidines were studied as prolyl oligopeptidase inhibitors. The compounds were more potent than expected from the assumption that the tetrazole would also here be a bioisostere of the carboxylic acid group and the corresponding carboxylic acids are at their best only weak inhibitors. The aminoacyl groups L-prolyl and L-alanyl gave potent inhibitors with IC50 values of 12 and 129 nM, respectively. This was in line with typical prolyl oligopeptidase inhibitors; however, we did observe a difference with N-methyl-L-alanyl, which gave potent inhibitors in typical prolyl oligopeptidase inhibitors but not in our novel compound series. Furthermore, all studied 4-phenylbutanoyl-aminoacyl-2(S)-tetrazolylpyrrolidines decreased alpha-synuclein dimerization at the concentration of 10 mu M, also when they were only weak inhibitors of the proteolytic activity of the enzyme with an IC50 value of 205 mu M. Molecular docking studies revealed that the compounds are likely to bind differently to the enzyme compared to typical prolyl oligopeptidase inhibitors represented in this study by 4-phenylbutanoyl-aminoacyl-2(S)-cyanopyrrolidines.Peer reviewe

Improved functionalization of oleic acid-coated iron oxide nanoparticles for biomedical applications

Superparamagnetic iron oxide nanoparticles can providemultiple benefits for biomedical applications in aqueous environments such asmagnetic separation or magnetic resonance imaging. To increase the colloidal stability and allow subsequent reactions, the introduction of hydrophilic functional groups onto the particles’ surface is essential. During this process, the original coating is exchanged by preferably covalently bonded ligands such as trialkoxysilanes. The duration of the silane exchange reaction, which commonly takes more than 24 h, is an important drawback for this approach. In this paper, we present a novel method, which introduces ultrasonication as an energy source to dramatically accelerate this process, resulting in high-quality waterdispersible nanoparticles around 10 nmin size. To prove the generic character, different functional groups were introduced on the surface including polyethylene glycol chains, carboxylic acid, amine, and thiol groups. Their colloidal stability in various aqueous buffer solutions as well as human plasma and serum was investigated to allow implementation in biomedical and sensing applications.status: publishe

Outcome of octogenarians with atrial fibrillation undergoing percutaneous coronary intervention: insights from the AFCAS registry

Background: More evidence is needed on the optimal antithrombotic regimen in elderly patients with atrial fibrillation (AF) undergoing percutaneous coronary intervention (PCI). Hypothesis: Octogenarian patients (aged ≥80 years) with AF who underwent PCI have worse 12-month clinical outcome, compared with younger patients. Methods: We performed a post-hoc analysis of data from the prospective, multicenter AFCAS registry, which enrolled consecutive patients with AF who underwent PCI and stenting. Outcome measures included major adverse cardiac/cerebrovascular events (MACCE; all-cause death, myocardial infarction, repeat revascularization, stent thrombosis, or stroke/transient ischemic attack) and bleeding events at 12-month follow-up. Results: Out of 925 AF patients enrolled in AFCAS registry, 195 (21.1%) were ≥80 years. Mean age was 82.9 ± 2.6 years; 41.5% were women; 32.3% had diabetes mellitus. Compared with patients aged &lt;80 years, there were more females among the octogenarians (P &lt; 0.001). Compared with younger patients, octogenarians smoked and had dyslipidemia less often, and presented more frequently with acute coronary syndrome. The frequency and duration of antithrombotic regimens prescribed at discharge were comparable. At 12-month follow-up, overall MACCE rate was higher in octogenarians compared with younger patients (27.7% vs 20.1%, P = 0.02). The rate of acute myocardial infarction was higher in octogenarians (9.2% vs 4.9%, P = 0.02), but the rates of all bleeds and BARC &gt;2 bleeds were similar (P = 0.13, P = 0.29, respectively). Conclusions: In real-world patients with AF undergoing PCI, patients aged ≥80 years had higher incidence of MACCE at 12-month follow-up compared with younger patients, although they received comparable antithrombotic treatment. The rates of bleeding events were similar

Cell-based screen for altered nuclear phenotypes reveals senescence progression in polyploid cells after Aurora kinase B inhibition.

Cellular senescence is a widespread stress response and is widely considered to be an alternative cancer therapeutic goal. Unlike apoptosis, senescence is composed of a diverse set of subphenotypes, depending on which of its associated effector programs are engaged. Here we establish a simple and sensitive cell-based prosenescence screen with detailed validation assays. We characterize the screen using a focused tool compound kinase inhibitor library. We identify a series of compounds that induce different types of senescence, including a unique phenotype associated with irregularly shaped nuclei and the progressive accumulation of G1 tetraploidy in human diploid fibroblasts. Downstream analyses show that all of the compounds that induce tetraploid senescence inhibit Aurora kinase B (AURKB). AURKB is the catalytic component of the chromosome passenger complex, which is involved in correct chromosome alignment and segregation, the spindle assembly checkpoint, and cytokinesis. Although aberrant mitosis and senescence have been linked, a specific characterization of AURKB in the context of senescence is still required. This proof-of-principle study suggests that our protocol is capable of amplifying tetraploid senescence, which can be observed in only a small population of oncogenic RAS-induced senescence, and provides additional justification for AURKB as a cancer therapeutic target.This work was supported by the University of Cambridge, Cancer Research UK, Hutchison Whampoa; Cancer Research UK grants A6691 and A9892 (M.N., N.K., C.J.T., D.C.B., C.J.C., L.S.G, and M.S.); a fellowship from the Uehara Memorial Foundation (M.S.).This is the author accepted manuscript. The final version is available from the American Society for Cell Biology via http://dx.doi.org/10.1091/mbc.E15-01-000

Rational design of selective histone deacetylase inhibitors

The concept of gene expression is continuously explained with epigenetic modifications. One of the most studied enzymes which have an influence on histone posttranslational modifications are histone deacetylases (HDACs). The overexpression and alterations in the structure of HDACs isoforms are described in the pathogenesis of cancer, inflammation and neurodegeneration. With different cellular function and tissue distribution of HDACs, scientists introduced them as attractive targets used in novel drug discovery protocols. Rational drug design of novel small molecules is usually guided by computational approaches. In our laboratory, we use ligand-based (pharmacophore modeling and virtual screening) and structure-based (molecular docking and molecular dynamics) drug design methodologies. The main focus in our drug design project is identification of selective HDAC6 and SIRT2 inhibitors. With respect to all published data, very small number of selective HDAC modulators has been reported so far. Here, we present rational design of novel selective HDAC6 and SIRT2 inhibitors as promising drug candidates for further development and structure optimization.http://www.socphyschemserb.org/en/events/physical-chemistry-2018

Computer-aided drug design of selective histone deacetylase inhibitors

The concept of gene expression is continuously explained with epigenetic modification. Post-translational histone acetylation and DNA methylation are dominant epigenetic alterations of the genome. Histone deacetylases (HDAC) play essential role in this process and therefore are very intensively investigated drug targets. The alteration in the structure and function of HDAC isoforms are identified in the pathogenesis of inflammation, cancer, and neurodegeneration. Eleven human HDAC isoforms are sharing a highly conserved catalytic domain. Among them, HDAC6 and SIRT2 are important for a wide range of diseases, due to their unique physiological functions. In our research, we have applied pharmacophore modelling, virtual screening, molecular docking and molecular dynamic methodologies for design and identification of selective HDAC6 and SIRT2 inhibitors. Recently resolved the crystal structure of catalytic domain II of human HDAC6 discovered a wide binding site essential for the substrate recognition. We have successfully used these structural features of human HDAC6 catalytic domain II to rationally design selective HDAC6 inhibitors. Newly published X-ray structures of selective ligand-SIRT2 complexes have revealed high conformational flexibility of this enzyme, and gave us more details about mechanism of action of sirtuin 2 inhibitors. Based on these findings we have performed molecular dynamic study of SIRT2 and tried to explain the conformational changes during enzyme catalysis. Since small number of selective HDAC modulators have been reported so far, rational design of HDAC6 and SIRT2 inhibitors are essential for further progress in discovery of epigenetic drugs.Journal of organic & inorganic chemistr

Fetal-derived macrophages dominate in adult mammary glands

Macrophages serve multiple functions including immune regulation, morphogenesis, tissue homeostasis and healing reactions. The current paradigm holds that mammary gland macrophages first arise postnatally during the prepubertal period from the bone marrow-derived monocytes. Here we delineate the origins of tissue-resident mammary gland macrophages using high-dimension phenotypic analyses, cell-fate mapping experiments, gene-deficient mice lacking selective macrophage subtypes, and antibody-based depletion strategies. We show that tissue-resident macrophages are found in mammary glands already before birth, and that the yolk sac-derived and fetal liver-derived macrophages outnumber the adult-derived macrophages in the mammary gland also in the adulthood. In addition, fetal-derived mammary gland macrophages have a characteristic phenotype, display preferential periductal and perivascular localization, and are highly active in scavenging. These findings identify fetal-derived macrophages as the predominant leukocyte type in the adult mammary gland stroma, and reveal previously unknown complexity of macrophage biology in the breast