51
|
Klevstig M, Scharin Täng M, Ståhlman M, Levin M, Borén J. Microsomal triglyceride transfer protein in the ischemic heart. Atherosclerosis 2016. [DOI: 10.1016/j.atherosclerosis.2016.07.624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
52
|
|
53
|
Svensson J, Sjögren K, Levin M, Borén J, Tivesten Å, Ohlsson C. Increased diet-induced fatty streak formation in female mice with deficiency of liver-derived insulin-like growth factor-I. Endocrine 2016; 52:550-60. [PMID: 26627099 PMCID: PMC4879167 DOI: 10.1007/s12020-015-0809-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 11/17/2015] [Indexed: 01/28/2023]
Abstract
The role of endocrine IGF-I for atherosclerosis is unclear. We determined the importance of circulating, liver-derived IGF-I for fatty streak formation in mice. Mice with adult, liver-specific IGF-I inactivation (LI-IGF-I(-/-) mice, serum IGF-I reduced by approximately 80 %) and control mice received an atherogenic (modified Paigen) diet between 6 and 12 months of age. At study end, Oil Red O staining of aortic root cryosections showed increased fatty streak area and lipid deposition in female but not in male LI-IGF-I(-/-) mice compared to controls. Mac-2 staining of aortic root and measurements of CD68 mRNA level in femoral artery revealed increased macrophage accumulation in proportion to the increased fatty streak area in female LI-IGF-I(-/-) mice. Moreover, female LI-IGF-I(-/-) mice displayed increased serum cholesterol and interleukin-6 as well as increased vascular cell-adhesion molecule 1 (VCAM1) mRNA levels in the femoral artery and elevated VCAM1 protein expression in the aortic root. Thus, increased diet-induced fatty streak formation in female LI-IGF-I(-/-) mice was associated with increased serum cholesterol and signs of systemic inflammation, endothelial activation, lipid deposition, and macrophage infiltration in the vascular wall.
Collapse
|
54
|
Gliddon HD, Howes PD, Kaforou M, Levin M, Stevens MM. A nucleic acid strand displacement system for the multiplexed detection of tuberculosis-specific mRNA using quantum dots. NANOSCALE 2016; 8:10087-95. [PMID: 27088427 DOI: 10.1039/c6nr00484a] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The development of rapid, robust and high performance point-of-care diagnostics relies on the advancement and combination of various areas of research. We have developed an assay for the detection of multiple mRNA molecules that combines DNA nanotechnology with fluorescent nanomaterials. The core switching mechanism is toehold-mediated strand displacement. We have used fluorescent quantum dots (QDs) as signal transducers in this assay, as they bring many benefits including bright fluorescence and multiplexing abilities. The resulting assay is capable of multiplexed detection of long RNA targets against a high concentration of background non-target RNA, with high sensitivity and specificity and limits of detection in the nanomolar range using only a standard laboratory plate reader. We demonstrate the utility of our QD-based system for the detection of two genes selected from a microarray-derived tuberculosis-specific gene expression signature. Levels of up- and downregulated gene transcripts comprising this signature can be combined to give a disease risk score, making the signature more amenable for use as a diagnostic marker. Our QD-based approach to detect these transcripts could pave the way for novel diagnostic assays for tuberculosis.
Collapse
|
55
|
Pezzulo G, Levin M. Re-membering the body: applications of computational neuroscience to the top-down control of regeneration of limbs and other complex organs. Integr Biol (Camb) 2015; 7:1487-517. [PMID: 26571046 DOI: 10.1039/c5ib00221d] [Citation(s) in RCA: 93] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
A major goal of regenerative medicine and bioengineering is the regeneration of complex organs, such as limbs, and the capability to create artificial constructs (so-called biobots) with defined morphologies and robust self-repair capabilities. Developmental biology presents remarkable examples of systems that self-assemble and regenerate complex structures toward their correct shape despite significant perturbations. A fundamental challenge is to translate progress in molecular genetics into control of large-scale organismal anatomy, and the field is still searching for an appropriate theoretical paradigm for facilitating control of pattern homeostasis. However, computational neuroscience provides many examples in which cell networks - brains - store memories (e.g., of geometric configurations, rules, and patterns) and coordinate their activity towards proximal and distant goals. In this Perspective, we propose that programming large-scale morphogenesis requires exploiting the information processing by which cellular structures work toward specific shapes. In non-neural cells, as in the brain, bioelectric signaling implements information processing, decision-making, and memory in regulating pattern and its remodeling. Thus, approaches used in computational neuroscience to understand goal-seeking neural systems offer a toolbox of techniques to model and control regenerative pattern formation. Here, we review recent data on developmental bioelectricity as a regulator of patterning, and propose that target morphology could be encoded within tissues as a kind of memory, using the same molecular mechanisms and algorithms so successfully exploited by the brain. We highlight the next steps of an unconventional research program, which may allow top-down control of growth and form for numerous applications in regenerative medicine and synthetic bioengineering.
Collapse
|
56
|
Tosenberger A, Bessonov N, Levin M, Reinberg N, Volpert V, Morozova N. A conceptual model of morphogenesis and regeneration. Acta Biotheor 2015; 63:283-94. [PMID: 25822060 DOI: 10.1007/s10441-015-9249-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Accepted: 03/18/2015] [Indexed: 12/11/2022]
Abstract
This paper is devoted to computer modelling of the development and regeneration of multicellular biological structures. Some species (e.g. planaria and salamanders) are able to regenerate parts of their body after amputation damage, but the global rules governing cooperative cell behaviour during morphogenesis are not known. Here, we consider a simplified model organism, which consists of tissues formed around special cells that can be interpreted as stem cells. We assume that stem cells communicate with each other by a set of signals, and that the values of these signals depend on the distance between cells. Thus the signal distribution characterizes location of stem cells. If the signal distribution is changed, then the difference between the initial and the current signal distribution affects the behaviour of stem cells-e.g. as a result of an amputation of a part of tissue the signal distribution changes which stimulates stem cells to migrate to new locations, appropriate for regeneration of the proper pattern. Moreover, as stem cells divide and form tissues around them, they control the form and the size of regenerating tissues. This two-level organization of the model organism, with global regulation of stem cells and local regulation of tissues, allows its reproducible development and regeneration.
Collapse
|
57
|
Shah V, Christov G, Mukasa T, Brogan KS, Wade A, Eleftheriou D, Levin M, Tulloh RM, Almeida B, Dillon MJ, Marek J, Klein N, Brogan PA. Cardiovascular status after Kawasaki disease in the UK. Heart 2015; 101:1646-55. [PMID: 26316045 PMCID: PMC4621377 DOI: 10.1136/heartjnl-2015-307734] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 07/07/2015] [Indexed: 01/12/2023] Open
Abstract
OBJECTIVE Kawasaki disease (KD) is an acute vasculitis that causes coronary artery aneurysms (CAA) in young children. Previous studies have emphasised poor long-term outcomes for those with severe CAA. Little is known about the fate of those without CAA or patients with regressed CAA. We aimed to study long-term cardiovascular status after KD by examining the relationship between coronary artery (CA) status, endothelial injury, systemic inflammatory markers, cardiovascular risk factors (CRF), pulse-wave velocity (PWV) and carotid intima media thickness (cIMT) after KD. METHODS Circulating endothelial cells (CECs), endothelial microparticles (EMPs), soluble cell-adhesion molecules cytokines, CRF, PWV and cIMT were compared between patients with KD and healthy controls (HC). CA status of the patients with KD was classified as CAA present (CAA+) or absent (CAA-) according to their worst-ever CA status. Data are median (range). RESULTS Ninety-two KD subjects were studied, aged 11.9 years (4.3-32.2), 8.3 years (1.0-30.7) from KD diagnosis. 54 (59%) were CAA-, and 38 (41%) were CAA+. There were 51 demographically similar HC. Patients with KD had higher CECs than HC (p=0.00003), most evident in the CAA+ group (p=0.00009), but also higher in the CAA- group than HC (p=0.0010). Patients with persistent CAA had the highest CECs, but even those with regressed CAA had higher CECs than HC (p=0.011). CD105 EMPs were also higher in the KD group versus HC (p=0.04), particularly in the CAA+ group (p=0.02), with similar findings for soluble vascular cell adhesion molecule 1 and soluble intercellular adhesion molecule 1. There was no difference in PWV, cIMT, CRF or in markers of systemic inflammation in the patients with KD (CAA+ or CAA-) compared with HC. CONCLUSIONS Markers of endothelial injury persist for years after KD, including in a subset of patients without CAA.
Collapse
|
58
|
Levin M, Rotthus S, Wendel S, Najafi N, Källström E, Focke-Tejkl M, Valenta R, Flicker S, Ohlin M. Multiple independent IgE epitopes on the highly allergenic grass pollen allergen Phl p 5. Clin Exp Allergy 2015; 44:1409-19. [PMID: 25262820 PMCID: PMC4278554 DOI: 10.1111/cea.12423] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2014] [Revised: 07/06/2014] [Accepted: 08/15/2014] [Indexed: 11/30/2022]
Abstract
Background Group 5 allergens are small proteins that consist of two domains. They belong to the most potent respiratory allergens. Objective To determine the binding sites and to study allergic patients' IgE recognition of the group 5 allergen (Phl p 5) from timothy grass pollen using human monoclonal IgE antibodies that have been isolated from grass pollen allergic patients. Methods Using recombinant isoallergens, fragments, mutants and synthetic peptides of Phl p 5, as well as peptide-specific antibodies, the interaction of recombinant human monoclonal IgE and Phl p 5 was studied using direct binding and blocking assays. Cross-reactivity of monoclonal IgE with group 5 allergens in several grasses was studied and inhibition experiments with patients' polyclonal IgE were performed. Results Monoclonal human IgE showed extensive cross-reactivity with group 5 allergens in several grasses. Despite its small size of 29 kDa, four independent epitope clusters on isoallergen Phl p 5.0101, two in each domain, were recognized by human IgE. Isoallergen Phl p 5.0201 carried two of these epitopes. Inhibition studies with allergic patients' polyclonal IgE suggest the presence of additional IgE epitopes on Phl p 5. Conclusions & Clinical Relevance Our results reveal the presence of a large number of independent IgE epitopes on the Phl p 5 allergen explaining the high allergenic activity of this protein and its ability to induce severe allergic symptoms. High-density IgE recognition may be a general feature of many potent allergens and form a basis for the development of improved diagnostic and therapeutic procedures in allergic disease.
Collapse
|
59
|
Kijani S, Yrlid U, Heyden M, Levin M, Borén J, Fogelstrand P. Filter-Dense Multicolor Microscopy. PLoS One 2015; 10:e0119499. [PMID: 25739088 PMCID: PMC4349739 DOI: 10.1371/journal.pone.0119499] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Accepted: 01/30/2015] [Indexed: 11/19/2022] Open
Abstract
Immunofluorescence microscopy is a unique method to reveal the spatial location of proteins in tissues and cells. By combining antibodies that are labeled with different fluorochromes, the location of several proteins can simultaneously be visualized in one sample. However, because of the risk of bleed-through signals between fluorochromes, standard multicolor microscopy is restricted to a maximum of four fluorescence channels, including one for nuclei staining. This is not always enough to address common scientific questions. In particular, the use of a rapidly increasing number of marker proteins to classify functionally distinct cell populations and diseased tissues emphasizes the need for more complex multistainings. Hence, multicolor microscopy should ideally offer more channels to meet the current needs in biomedical science. Here we present an enhanced multi-fluorescence setup, which we call Filter-Dense Multicolor Microscopy (FDMM). FDMM is based on condensed filter sets that are more specific for each fluorochrome and allow a more economic use of the light spectrum. FDMM allows at least six independent fluorescence channels and can be applied to any standard fluorescence microscope without changing any operative procedures for the user. In the present study, we demonstrate an FDMM setup of six channels that includes the most commonly used fluorochromes for histology. We show that the FDMM setup is specific and robust, and we apply the technique on typical biological questions that require more than four fluorescence microscope channels.
Collapse
|
60
|
Koivisto AJ, Jensen ACØ, Levin M, Kling KI, Maso MD, Nielsen SH, Jensen KA, Koponen IK. Testing the near field/far field model performance for prediction of particulate matter emissions in a paint factory. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2015; 17:62-73. [PMID: 25407261 DOI: 10.1039/c4em00532e] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A Near Field/Far Field (NF/FF) model is a well-accepted tool for precautionary exposure assessment but its capability to estimate particulate matter (PM) concentrations is not well studied. The main concern is related to emission source characterization which is not as well defined for PM emitters compared to e.g. for solvents. One way to characterize PM emission source strength is by using the material dustiness index which is scaled to correspond to industrial use by using modifying factors, such as handling energy factors. In this study we investigate how well the NF/FF model predicts PM concentration levels in a paint factory. PM concentration levels were measured during big bag and small bag powder pouring. Rotating drum dustiness indices were determined for the specific powders used and applied in the NF/FF model to predict mass concentrations. Modeled process specific concentration levels were adjusted to be similar to the measured concentration levels by adjusting the handling energy factor. The handling energy factors were found to vary considerably depending on the material and process even-though they have the same values as modifying factors in the exposure models. This suggests that the PM source characteristics and process-specific handling energies should be studied in more detail to improve the model-based exposure assessment.
Collapse
|
61
|
Fagman JB, Wilhelmson AS, Motta BM, Pirazzi C, Alexanderson C, De Gendt K, Verhoeven G, Holmäng A, Anesten F, Jansson JO, Levin M, Borén J, Ohlsson C, Krettek A, Romeo S, Tivesten Å. The androgen receptor confers protection against diet-induced atherosclerosis, obesity, and dyslipidemia in female mice. FASEB J 2014; 29:1540-50. [PMID: 25550469 PMCID: PMC4470404 DOI: 10.1096/fj.14-259234] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 12/09/2014] [Indexed: 12/13/2022]
Abstract
Androgens have important cardiometabolic actions in males, but their metabolic role in females is unclear. To determine the physiologic androgen receptor (AR)–dependent actions of androgens on atherogenesis in female mice, we generated female AR-knockout (ARKO) mice on an atherosclerosis-prone apolipoprotein E (apoE)–deficient background. After 8 weeks on a high-fat diet, but not on a normal chow diet, atherosclerosis in aorta was increased in ARKO females (+59% vs. control apoE-deficient mice with intact AR gene). They also displayed increased body weight (+18%), body fat percentage (+62%), and hepatic triglyceride levels, reduced insulin sensitivity, and a marked atherogenic dyslipidemia (serum cholesterol, +52%). Differences in atherosclerosis, body weight, and lipid levels between ARKO and control mice were abolished in mice that were ovariectomized before puberty, consistent with a protective action of ovarian androgens mediated via the AR. Furthermore, the AR agonist dihydrotestosterone reduced atherosclerosis (−41%; thoracic aorta), subcutaneous fat mass (−44%), and cholesterol levels (−35%) in ovariectomized mice, reduced hepatocyte lipid accumulation in hepatoma cells in vitro, and regulated mRNA expression of hepatic genes pivotal for lipid homeostasis. In conclusion, we demonstrate that the AR protects against diet-induced atherosclerosis in female mice and propose that this is mediated by modulation of body composition and lipid metabolism.—Fagman, J. B., Wilhelmson, A. S., Motta, B. M., Pirazzi, C., Alexanderson, C., De Gendt, K., Verhoeven, G., Holmäng, A., Anesten, F., Jansson, J.-O., Levin, M., Borén, J., Ohlsson, C., Krettek, A., Romeo, S., Tivesten, A. The androgen receptor confers protection against diet-induced atherosclerosis, obesity, and dyslipidemia in female mice.
Collapse
|
62
|
Levin M, Davies AM, Liljekvist M, Carlsson F, Gould HJ, Sutton BJ, Ohlin M. Human IgE against the major allergen Bet v 1--defining an epitope with limited cross-reactivity between different PR-10 family proteins. Clin Exp Allergy 2014; 44:288-99. [PMID: 24447087 PMCID: PMC4215112 DOI: 10.1111/cea.12230] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 09/24/2013] [Accepted: 10/25/2013] [Indexed: 02/05/2023]
Abstract
Background The interaction between IgE and allergen is a key event at the initiation of an allergic response, and its characteristics have substantial effects on the clinical manifestation. Despite this, the molecular details of the interaction between human IgE and the major birch allergen Bet v 1, one of the most potent tree allergens, still remain poorly investigated. Objective To isolate Bet v 1-specific human monoclonal IgE and characterize their interaction with the allergen. Methods Recombinant human IgE were isolated from a combinatorial antibody fragment library and their interaction with Bet v 1 assessed using various immunological assays. The structure of one such IgE in the single-chain fragment variable format was determined using X-ray crystallography. Results We present four novel Bet v 1-specific IgE, for one of which we solve the structure, all with their genetic origin in the IGHV5 germline gene, and demonstrate that they target two non-overlapping epitopes on the surface of Bet v 1, thereby fulfilling the basic criteria for FcεRI cross-linkage. We further define these epitopes and for one epitope pinpoint single amino acid residues important for the interaction with human IgE. This provides a potential explanation, at the molecular level, for the differences in recognition of isoforms of Bet v 1 and other allergens in the PR-10 protein family displayed by IgE targeting this epitope. Finally, we present the first high-resolution structure of a human allergen-specific IgE fragment in the single-chain fragment variable (scFv) format. Conclusions and Clinical Relevance We here display the usefulness of allergen-specific human monoclonal IgE as a tool in studies of the crucial molecular interaction taking place at the initiation of an allergic response. Such studies may aid us in development of better diagnostic tools and guide us in the development of new therapeutic compounds.
Collapse
|
63
|
Zhang X, Johansson M, Lundberg A, Levin M, Yuan X, Folkersen L, Eriksson P, Hedin U, Boren J, Hansson G, Yan Z. The role of innate immune receptor nod2 in atherosclerosis. Atherosclerosis 2014. [DOI: 10.1016/j.atherosclerosis.2014.05.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
64
|
Hansson E, Manjer J, Börrén J, Levin M, Mulder L, Ringberg A. A feasible computer-based evaluation tool for reduction mammaplasty patients: indications for operation and monitoring of guidelines. J Plast Reconstr Aesthet Surg 2014; 67:927-31. [PMID: 24816579 DOI: 10.1016/j.bjps.2014.03.028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Revised: 12/18/2013] [Accepted: 03/15/2014] [Indexed: 11/15/2022]
Abstract
In Sweden, evidence-based national guidelines for the indication for reduction mammaplasty in the public health-care system have been developed by a group of experts. They were defined as breast volume≥800 ml at normal weight. Furthermore, a volume asymmetry of 25% or at least 200 ml or an extreme ptosis may be an indication in some cases. The aim of the present paper was to describe an easy-to-use computer-based tool that has been developed to assure that patients with mammary hyperplasia are evaluated and offered care in a standardized fashion and that the adherence to the guidelines is monitored. Included variables were based on a model for priority grouping originally presented by Strömbeck and Malm in 1986 and comprise body mass index (BMI), BMI-corrected breast volume, ptosis, asymmetry, and general breast-related factors preoperatively and 1 year postoperatively and complications postoperatively. Between June 2007 and January 2013, 377 patients were evaluated. Of which, 275 qualified for operation. With the help of the computer-based tool, compliance to the indications for operation can be easily followed, and hence the intended patients offered a reduction mammaplasty in the public health-care system.
Collapse
|
65
|
Duch P, Nørgaard AW, Hansen JS, Sørli JB, Jacobsen P, Lynggard F, Levin M, Nielsen GD, Wolkoff P, Ebbehøj NE, Larsen ST. Pulmonary toxicity following exposure to a tile coating product containing alkylsiloxanes. A clinical and toxicological evaluation. Clin Toxicol (Phila) 2014; 52:498-505. [PMID: 24815546 PMCID: PMC4086232 DOI: 10.3109/15563650.2014.915412] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
CONTEXT Coating products are widely used for making surfaces water and dirt repellent. However, on several occasions the use of these products has been associated with lung toxicity. OBJECTIVE In the present study, we evaluated the toxic effects of an aerosolized tile-coating product. METHODS Thirty-nine persons, who reported respiratory and systemic symptoms following exposure to the tile-coating product, were clinically examined. The product was analysed chemically and furthermore, the exposure scenario was reconstructed using a climate chamber and the toxicological properties of the product were studied using in vivo and by in vitro surfactometry. RESULTS The symptoms developed within few hours and included coughing, tachypnoea, chest pain, general malaise and fever. The physical examination revealed perihilar lung infiltrates on chest radiograph and reduced blood oxygen saturation. The acute symptoms resolved gradually within 1-3 days and no delayed symptoms were observed. By means of mass spectrometry and X-ray spectroscopy, it was shown that the product contained non-fluorinated alkylsiloxanes. The exposure conditions in the supermarket were reconstructed under controlled conditions in a climate chamber and particle and gas exposure levels were monitored over time allowing estimation of human exposure levels. Mice exposed to the product developed symptoms of acute pulmonary toxicity in a concentration-and time-dependent manner. The symptoms of acute pulmonary toxicity likely resulted from inhibition of the pulmonary surfactant function as demonstrated by in vitro surfactometry. Among these patients only a partial association between the level of exposure and the degree of respiratory symptoms was observed, which could be because of a high inter-individual difference in sensitivity and time-dependent changes in the chemical composition of the aerosol. CONCLUSION Workers need to cautiously apply surface coating products because the contents can be highly toxic through inhalation, and the aerosols can disperse to locations remote from the worksite and affect bystanders.
Collapse
|
66
|
Pirazzi C, Valenti L, Motta BM, Pingitore P, Hedfalk K, Mancina RM, Burza MA, Indiveri C, Ferro Y, Montalcini T, Maglio C, Dongiovanni P, Fargion S, Rametta R, Pujia A, Andersson L, Ghosal S, Levin M, Wiklund O, Iacovino M, Borén J, Romeo S. PNPLA3 has retinyl-palmitate lipase activity in human hepatic stellate cells. Hum Mol Genet 2014; 23:4077-85. [PMID: 24670599 PMCID: PMC4082369 DOI: 10.1093/hmg/ddu121] [Citation(s) in RCA: 260] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Retinoids are micronutrients that are stored as retinyl esters in the retina and hepatic stellate cells (HSCs). HSCs are key players in fibrogenesis in chronic liver diseases. The enzyme responsible for hydrolysis and release of retinyl esters from HSCs is unknown and the relationship between retinoid metabolism and liver disease remains unclear. We hypothesize that the patatin-like phospholipase domain-containing 3 (PNPLA3) protein is involved in retinol metabolism in HSCs. We tested our hypothesis both in primary human HSCs and in a human cohort of subjects with non-alcoholic fatty liver disease (N = 146). Here we show that PNPLA3 is highly expressed in human HSCs. Its expression is regulated by retinol availability and insulin, and increased PNPLA3 expression results in reduced lipid droplet content. PNPLA3 promotes extracellular release of retinol from HSCs in response to insulin. We also show that purified wild-type PNPLA3 hydrolyzes retinyl palmitate into retinol and palmitic acid. Conversely, this enzymatic activity is markedly reduced with purified PNPLA3 148M, a common mutation robustly associated with liver fibrosis and hepatocellular carcinoma development. We also find the PNPLA3 I148M genotype to be an independent (P = 0.009 in a multivariate analysis) determinant of circulating retinol-binding protein 4, a reliable proxy for retinol levels in humans. This study identifies PNPLA3 as a lipase responsible for retinyl-palmitate hydrolysis in HSCs in humans. Importantly, this indicates a potential novel link between HSCs, retinoid metabolism and PNPLA3 in determining the susceptibility to chronic liver disease.
Collapse
|
67
|
Moshe S, Levin M, Yagev Y. [Summary of the the 6th ICOH Conference on Work Environment and Cardiovascular Disease, Tokyo 2013]. HAREFUAH 2014; 153:226-227. [PMID: 24791572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
|
68
|
Abstract
Kawasaki disease (KD) is an acute self-limiting inflammatory disorder, associated with vasculitis, affecting predominantly medium-sized arteries, particularly the coronary arteries. In developed countries KD is the commonest cause of acquired heart disease in childhood. The aetiology of KD remains unknown, and it is currently believed that one or more as yet unidentified infectious agents induce an intense inflammatory host response in genetically susceptible individuals. Genetic studies have identified several susceptibility genes for KD and its sequelae in different ethnic populations, including FCGR2A, CD40, ITPKC, FAM167A-BLK and CASP3, as well as genes influencing response to intravenous immunoglobulin (IVIG) and aneurysm formation such as FCGR3B, and transforming growth factor (TGF) β pathway genes. IVIG and aspirin are effective therapeutically, but recent clinical trials and meta-analyses have demonstrated that the addition of corticosteroids to IVIG is beneficial for the prevention of coronary artery aneurysms (CAA) in severe cases with highest risk of IVIG resistance. Outside of Japan, however, clinical scores to predict IVIG resistance perform suboptimally. Furthermore, the evidence base does not provide clear guidance on which corticosteroid regimen is most effective. Other therapies, including anti-TNFα, could also have a role for IVIG-resistant KD. Irrespective of these caveats, it is clear that therapy that reduces inflammation in acute KD, improves outcome. This paper summarises recent advances in the understanding of KD pathogenesis and therapeutics, and provides an approach for managing KD patients in the UK in the light of these advances.
Collapse
|
69
|
O'Shaughnessy J, Levin M, Palmer G, Ross JS, Palma N, Yelensky R, Cao Y, Ramos C, Hoke G, Wang K. Abstract P4-04-12: Identification of a common genotype in patients (pts) with HER2-positive, ER-negative, inflammatory breast cancer (IBC) that was primary-refractory to trastuzumab who have had 5+ years of disease control with lapatinib therapy. Cancer Res 2013. [DOI: 10.1158/0008-5472.sabcs13-p4-04-12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Background: HER2-amplified inflammatory breast cancer (IBC) that is primary-refractory to trastuzumab has a poor prognosis. The objective of this study was to describe the genotypes of the IBC obtained from 3 pts with high grade, ER-negative, HER2+ classical IBC, primary-refractory to trastuzumab, with chest wall disease, who remain with no evidence of disease (NED) on lapatinib for 5+ years.
The 3 postmenopausal pts presented with locally advanced IBC, 2 with disease extending onto the chest wall, and the third with chest wall recurrence while on adjuvant trastuzumab. Two pts were treated with preoperative trastuzumab with multiple chemotherapy agents with no response. They were then treated with preoperative lapatinib and had a clinical partial response. They underwent salvage mastectomy showing extensive residual disease, followed by chest wall/regional radiotherapy (RT), continuing on lapatinib. The third patient received preoperative AC followed by docetaxel and had extensive residual disease at mastectomy. She underwent chest wall/regional RT and then had chest wall recurrence while on adjuvant trastuzumab. She was treated with lapatinib and resection of residual chest wall disease. All 3 pts remain NED on 1250mg lapatinib daily. The 3 pts have a strong family history of breast cancer; two have known wild type germline BRCA1/2.
Methods: Following IRB-approved informed consent, targeted next generation DNA sequencing (NGS) was performed using HiSeq-2000 (Illumina) on pts’ FFPE primary IBC at a CLIA-certified laboratory, to characterize all classes of genomic alterations across 4,604 exons of 287 cancer-related genes. Phosphoprotein analysis was performed using a proprietary Reverse Phase Protein Microarray (RPMA) platform on pts's FFPE IBC to characterize the activity of the targets of anti-HER2 therapy, and their downstream pathways.
Results: In 2 pts’ IBCs NGS identified a common genotype with amplified ERBB2, mutant p53 and PIK3CA (c.3140A>G_p.H1047R), homozygous deletions of both CDKN2A and CDKN2B, and truncated BRCA2 (1 pt) or PALB2 (1 pt). The third pt's FFPE residual disease from her mastectomy did not yield sufficient DNA from invasive tumor cells for sequencing and we plan to sequence DNA from her original diagnostic core biopsy. Phosphoprotein analysis of one pt's trastuzumab-refractory, lapatinib-naive IBC showed 3+ expression of HER1 (but not pHER1 Y1068 nor pHER2 Y1248), pAkt S473, pS6 ribosomal S235-236 protein (2+), p4E-BP1 S65 and Notch1. The second pt's lapatinib-treated IBC showed 3+ overexpression of only p4E-BP1 S65.
Conclusions: Pts with a common tumor phenotype who have highly durable responses with a targeted therapy may share a common tumor genotype. Two pts’ trastuzumab-refractory HER2+ IBCs that have been very durably responsive to lapatinib share p53, PIK3CA, p16 and BRCA2-related mutations, potentially enabling the prospective identification of trastuzumab-refractory IBC pts who may benefit substantially from lapatinib.
Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-04-12.
Collapse
|
70
|
Lindgren A, Levin M, Rodrigo Blomqvist S, Wikström J, Ahnmark A, Mogensen C, Böttcher G, Bohlooly-Y M, Borén J, Gan LM, Lindén D. Adiponectin receptor 2 deficiency results in reduced atherosclerosis in the brachiocephalic artery in apolipoprotein E deficient mice. PLoS One 2013; 8:e80330. [PMID: 24324556 PMCID: PMC3855811 DOI: 10.1371/journal.pone.0080330] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Accepted: 09/26/2013] [Indexed: 01/01/2023] Open
Abstract
Adiponectin has been shown to have beneficial cardiovascular effects and to signal through the adiponectin receptors, AdipoR1 and AdipoR2. The original aim of this study was to investigate the effect of combined AdipoR1 and AdipoR2 deficiency (AdipoR1-/-AdipoR2-/-) on atherosclerosis. However, we made the interesting observation that AdipoR1-/-AdipoR2-/- leads to embryonic lethality demonstrating the critical importance of the adiponectin signalling system during development. We then investigated the effect of AdipoR2-ablation on the progression of atherosclerosis in apolipoprotein E deficient (ApoE-/-) mice. AdipoR2-/-ApoE-/- mice fed an atherogenic diet had decreased plaque area in the brachiocephalic artery compared with AdipoR2+/+ApoE-/- littermate controls as visualized in vivo using an ultrasound biomicroscope and confirmed by histological analyses. The decreased plaque area in the brachiocephalic artery could not be explained by plasma cholesterol levels or inflammatory status. However, accumulation of neutral lipids was decreased in peritoneal macrophages from AdipoR2-/-ApoE-/- mice after incubation with oxidized LDL. This effect was associated with lower CD36 and higher ABCA1 mRNA levels in peritoneal macrophages from AdipoR2-/-ApoE-/- mice compared with AdipoR2+/+ApoE-/- controls after incubation with oxidized LDL. In summary, we show that adiponectin receptors are crucial during embryonic development and that AdipoR2-deficiency slows down the progression of atherosclerosis in the brachiocephalic artery of ApoE-deficient mice.
Collapse
|
71
|
Moshe S, Levin M. [Summary of the occupational aspects in the ERS (European Respiratory Conference) Conference Vienna 2012]. HAREFUAH 2013; 152:680-681. [PMID: 24416830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
|
72
|
Borén J, Taskinen MR, Olofsson SO, Levin M. Ectopic lipid storage and insulin resistance: a harmful relationship. J Intern Med 2013; 274:25-40. [PMID: 23551521 DOI: 10.1111/joim.12071] [Citation(s) in RCA: 157] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Obesity increases the risk of metabolic diseases, including insulin resistance and type 2 diabetes, as well as cardiovascular disease. In addition to lipid accumulation in adipose tissue, obesity is associated with increased lipid storage in ectopic tissues, such as skeletal muscle and liver. Furthermore, lipid accumulation in the heart may result in cardiac dysfunction and heart failure. It has recently been demonstrated that intracellular lipid accumulation in ectopic tissues leads to pathological responses and impaired insulin signalling. Here, we will review the current understanding of how lipid storage and lipid droplet physiology affect the risk of developing metabolic diseases.
Collapse
|
73
|
De Maria S, Nürnberg J, Lin HM, Contreras-Saldivar AG, Levin M, Flax K, Groth D, Vullo J, Rocca J, Florman S, Reich DL. Association of intraoperative blood pressure instability with adverse outcomes after liver transplantation. Minerva Anestesiol 2013; 79:604-616. [PMID: 23511361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
BACKGROUND Blood pressure derangements are common in orthotopic liver transplantation (OLT), and are potentially associated with adverse outcomes if they are sustained. While this concept is often believed to be true, few have rigorously demonstrated the validity of this claim, especially in likely vulnerable OLT patients. METHODS We retrospectively investigated 827 patients who underwent OLT to determine the magnitude of these hemodynamic associations with adverse outcomes. The median value of the mean arterial pressure (MAP) and the fractional change in the median MAP between subsequent epochs (FCM) were calculated for every 5-minute epoch intraoperatively. Epochs were classified according to prespecified ranges of MAP and fractional changes in MAP (lability) between epochs. Multivariate stepwise logistic regression was used to model associations of risk factors and epochs of intraoperative blood pressure (BP) instability with primary (30-day mortality and/or graft failure) and secondary adverse outcomes. RESULTS Primary adverse outcomes occurred in 10.9% and 12.2% of patients for 30-day mortality and 30-day graft failure, respectively. Independent hemodynamic predictors for 30-day mortality and graft failure included sustained periods of MAP <50 mmHg and BP lability where the MAP changed >25%. All of these values were statistically significant. CONCLUSION Although severe intraoperative hypotension and BP lability during OLT are often observed in current practice as consequences of major surgical manipulations and patient vulnerability, these are likely not benign conditions based on this retrospective analysis. Prospective trials are warranted to investigate the possibility that interventions tailored to avoidance of hypotension and BP lability may improve outcomes.
Collapse
|
74
|
Li L, Ståhlman M, Rutberg M, Håversen L, Fogelstrand P, Andersson L, Levin M, Borén J. ARF6 regulates neuron differentiation through glucosylceramide synthase. PLoS One 2013; 8:e60118. [PMID: 23555901 PMCID: PMC3610931 DOI: 10.1371/journal.pone.0060118] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Accepted: 02/21/2013] [Indexed: 01/09/2023] Open
Abstract
The small GTPase ADP ribosylation factor 6 (ARF6) mediates endocytosis and has in addition been shown to regulate neuron differentiation. Here we investigated whether ARF6 promotes differentiation of Neuro-2a neuronal cells by modifying the cellular lipid composition. We showed that knockdown of ARF6 by siRNA in Neuro-2a cells increased neuronal outgrowth as expected. ARF6 knockdown also resulted in increased glucosylceramide levels and decreased sphingomyelin levels, but did not affect the levels of ceramide or phospholipids. We speculated that the ARF6 knockdown-induced increase in glucosylceramide was caused by an effect on glucosylceramide synthase and, in agreement, showed that ARF6 knockdown increased the mRNA levels and activity of glucosylceramide synthase. Finally, we showed that incubation of Neuro-2a cells with the glucosylceramide synthase inhibitor D-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol (D-PDMP) normalized the increased neuronal outgrowth induced by ARF6 knockdown. Our results thus show that ARF6 regulates neuronal differentiation through an effect on glucosylceramide synthase and glucosylceramide levels.
Collapse
|
75
|
Pirazzi C, Adiels M, Burza MA, Mancina RM, Levin M, Ståhlman M, Taskinen MR, Orho-Melander M, Perman J, Pujia A, Andersson L, Maglio C, Montalcini T, Wiklund O, Borén J, Romeo S. Patatin-like phospholipase domain-containing 3 (PNPLA3) I148M (rs738409) affects hepatic VLDL secretion in humans and in vitro. J Hepatol 2012; 57:1276-82. [PMID: 22878467 DOI: 10.1016/j.jhep.2012.07.030] [Citation(s) in RCA: 211] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Revised: 06/22/2012] [Accepted: 07/26/2012] [Indexed: 12/11/2022]
Abstract
BACKGROUND & AIMS The robust association between non-alcoholic fatty liver disease (NAFLD) and the genetic variant I148M (rs738409) in PNPLA3 has been widely replicated. The aim of this study was to investigate the effect of the PNPLA3 I148M mutation on: (1) hepatic secretion of very low density lipoproteins (VLDL) in humans; and (2) secretion of apolipoprotein B (apoB) from McA-RH 7777 cells, which secrete VLDL-sized apoB-containing lipoproteins. METHODS VLDL kinetics was analyzed after a bolus infusion of stable isotopes in 55 overweight/obese men genotyped for the PNPLA3 I148M variant. Intracellular lipid content, apoB secretion and glycerolipid metabolism were studied in McA-RH 7777 cells overexpressing the human 148I wild type or 148M mutant PNPLA3 protein. RESULTS In humans, carriers of the PNPLA3 148M allele had increased liver fat compared to 148I homozygotes, and kinetic analysis showed a relatively lower secretion of the large, triglyceride-rich VLDL (VLDL(1)) in 148M carriers vs. 148I homozygotes for the same amount of liver fat. McA-RH 7777 cells overexpressing the 148M mutant protein showed a higher intracellular triglyceride content with a lower apoB secretion and fatty acid efflux, compared to cells overexpressing the 148I wild type protein. The responses with 148M matched those observed in cells expressing the empty vector, indicating that the mutation results in loss of function. CONCLUSIONS We have shown that PNPLA3 affects the secretion of apoB-containing lipoproteins both in humans and in vitro and that the 148M protein is a loss-of-function mutation. We propose that PNPLA3 148M promotes intracellular lipid accumulation in the liver by reducing the lipidation of VLDL.
Collapse
|