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Ougaard ME, Sembach FE, Kvist PH, Tonnesen M, Frederiksen KS, Egfjord M, Jensen HE, Galsgaard ED. Temporal Regulation of Glomerular and Cortical Tubulointerstitial Genes Involved in the Development of Nephrotoxic Serum Nephritis. Nephron Clin Pract 2018; 140:218-230. [PMID: 30205387 DOI: 10.1159/000492294] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2018] [Accepted: 07/23/2018] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS Murine nephrotoxic nephritis (NTN) is a well-established model resembling chronic kidney disease. Investigating gene expression patterns separately in the glomerular and cortical tubulointerstitial structure could provide new knowledge about structure-specific changes in expression of genes in the NTN model. METHODS Glomerular, cortical tubulointerstitial and whole kidney tissues from mice subjected to nephrotoxic serum (NTS) or phosphate buffered saline (PBS) were collected on day 7, 21 and 42 using laser microdissection (LMD). Total RNA was extracted and subjected to nCounter NanoString. Histology, immunohistochemistry, in situ hybridization and/or quantitative real time PCR (qRT PCR) were performed to confirm regulation of selected genes. RESULTS LMD provided detailed information about genes that were regulated differently between structures over time. Some of the fibrotic and inflammatory genes (Col1a1, Col3a1 and Ccl2) were upregulated in both structures, whereas other genes such as Spp1 and Grem1 were differentially regulated suggesting spatial pathogenic mechanisms in the kidney. Downregulation of cortical tubulointerstitium genes involved in iron metabolism was detected along with iron accumulation. CONCLUSION This study demonstrates several regulated genes in pathways important for the pathogenesis of the NTN model and that LMD identifies structure-specific changes in gene expression during disease development. Furthermore, this study shows the benefits of isolating glomeruli and cortical tubulointerstitium in order to identify gene regulation.
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Affiliation(s)
- Maria E Ougaard
- Novo Nordisk A/S, Måløv, Denmark.,Department of Veterinary Disease Biology, University of Copenhagen, Copenhagen, Denmark
| | | | | | | | | | - Martin Egfjord
- Department of Nephrology, Copenhagen University Hospital, Copenhagen, Denmark
| | - Henrik E Jensen
- Department of Veterinary Disease Biology, University of Copenhagen, Copenhagen, Denmark
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Hansen JB, Dos Santos LRB, Liu Y, Prentice KJ, Teudt F, Tonnesen M, Jonas JC, Wheeler MB, Mandrup-Poulsen T. Glucolipotoxic conditions induce β-cell iron import, cytosolic ROS formation and apoptosis. J Mol Endocrinol 2018; 61:69-77. [PMID: 30030388 DOI: 10.1530/jme-17-0262] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 05/16/2018] [Indexed: 12/28/2022]
Abstract
Type 2 diabetes (T2D) arises when the pancreatic beta-cell fails to compensate for increased insulin needs due to insulin resistance. Glucolipotoxicity (GLT) has been proposed to induce beta-cell dysfunction in T2D by formation of reactive oxygen species (ROS). Here, we examined if modeling glucolipotoxic conditions by high glucose-high free fatty acid (FFA) exposure (GLT) regulates beta-cell iron transport, by increasing the cytosolic labile iron pool (LIP). In isolated mouse islets, the GLT-induced increase in the LIP catalyzed cytosolic ROS formation and induced apoptosis. We show that GLT-induced ROS production is regulated by an increased LIP associated with elevated expression of genes regulating iron import. Using pharmacological and transgenic approaches, we show that iron reduction and decreased iron import protects from GLT-induced ROS production, prevents impairment of the mitochondrial membrane potential (MMP) and inhibits apoptosis. This study identifies a novel pathway underlying GLT-induced apoptosis involving increased iron import, generation of hydroxyl radicals from hydrogen peroxide through the Fenton reaction in the cytosolic compartment associated with dissipation of the MMP and beta-cell apoptosis.
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Affiliation(s)
- Jakob Bondo Hansen
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Laila Romagueira Bichara Dos Santos
- Université Catholique de Louvain, Institute of Experimental and Clinical Research, Pole of Endocrinology, Diabetes and Nutrition, Brussels, Belgium
| | - Ying Liu
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Kacey J Prentice
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Frederik Teudt
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Morten Tonnesen
- Department of Diabetes Complications Biology & Pharmacology, Novo Nordisk, Måløv, Denmark
| | - Jean-Christophe Jonas
- Université Catholique de Louvain, Institute of Experimental and Clinical Research, Pole of Endocrinology, Diabetes and Nutrition, Brussels, Belgium
| | - Michael B Wheeler
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
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Cucak H, Mayer C, Tonnesen M, Thomsen LH, Grunnet LG, Rosendahl A. Macrophage contact dependent and independent TLR4 mechanisms induce β-cell dysfunction and apoptosis in a mouse model of type 2 diabetes. PLoS One 2014; 9:e90685. [PMID: 24594974 PMCID: PMC3940939 DOI: 10.1371/journal.pone.0090685] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Accepted: 02/03/2014] [Indexed: 12/21/2022] Open
Abstract
Type 2 diabetes (T2D) is evolving into a global disease and patients have a systemic low-grade inflammation, yet the role of this inflammation is still not established. One plausible mechanism is enhanced expression and activity of the innate immune system. Therefore, we evaluated the expression and the function of the toll-like receptor 4 (TLR4) on pancreatic β-cells in primary mouse islets and on the murine β-cell line MIN6 in the presence or absence of macrophages. Diabetic islets have 40% fewer TLR4 positive β-cells, but twice the number of TLR4 positive macrophages as compared to healthy islets. Healthy and diabetic islets respond to a TLR4 challenge with enhanced production of cytokines (5–10-fold), while the TLR4 negative β-cell line MIN6 fails to produce cytokines. TLR4 stimulation induces β-cell dysfunction in mouse islets, measured as reduced glucose stimulated insulin secretion. Diabetic macrophages from 4-months old mice have acquired a transient enhanced capacity to produce cytokines when stimulated with LPS. Interestingly, this is lost in 6-months old diabetic mice. TLR4 activation alone does not induce apoptosis in islets or MIN-6 cells. In contrast, macrophages mediate TLR4-dependent cell-contact dependent (3-fold) as well as cell-contact independent (2-fold) apoptosis of both islets and MIN-6 cells. Importantly, diabetic macrophages have a significantly enhanced capacity to induce β-cell apoptosis compared to healthy macrophages. Taken together, the TLR4 responsiveness is elevated in the diabetic islets and mainly mediated by newly recruited macrophages. The TLR4 positive macrophages, in both a cell-contact dependent and independent manner, induce apoptosis of β-cells in a TLR4 dependent fashion and TLR4 activation directly induces β-cell dysfunction. Thus, targeting either the TLR4 pathway or the macrophages provides a novel attractive treatment regime for T2D.
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Affiliation(s)
- Helena Cucak
- Hagedorn Research Institute, Department of Diabetic Complication Biology, Måløv, Denmark
| | - Christopher Mayer
- Hagedorn Research Institute, Department of Diabetic Complication Biology, Måløv, Denmark
| | - Morten Tonnesen
- Hagedorn Research Institute, Department of Diabetic Complication Biology, Måløv, Denmark
| | - Lise Høj Thomsen
- Hagedorn Research Institute, Department of Diabetic Complication Biology, Måløv, Denmark
| | | | - Alexander Rosendahl
- Hagedorn Research Institute, Department of Diabetic Complication Biology, Måløv, Denmark
- * E-mail:
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Poulsen HE, Specht E, Broedbaek K, Henriksen T, Ellervik C, Mandrup-Poulsen T, Tonnesen M, Nielsen PE, Andersen HU, Weimann A. RNA modifications by oxidation: a novel disease mechanism? Free Radic Biol Med 2012; 52:1353-61. [PMID: 22306201 DOI: 10.1016/j.freeradbiomed.2012.01.009] [Citation(s) in RCA: 155] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2011] [Revised: 01/18/2012] [Accepted: 01/18/2012] [Indexed: 12/28/2022]
Abstract
The past decade has provided exciting insights into a novel class of central (small) RNA molecules intimately involved in gene regulation. Only a small percentage of our DNA is translated into proteins by mRNA, yet 80% or more of the DNA is transcribed into RNA, and this RNA has been found to encompass various classes of novel regulatory RNAs, including, e.g., microRNAs. It is well known that DNA is constantly oxidized and repaired by complex genome maintenance mechanisms. Analogously, RNA also undergoes significant oxidation, and there are now convincing data suggesting that oxidation, and the consequent loss of integrity of RNA, is a mechanism for disease development. Oxidized RNA is found in a large variety of diseases, and interest has been especially devoted to degenerative brain diseases such as Alzheimer disease, in which up to 50-70% of specific mRNA molecules are reported oxidized, whereas other RNA molecules show virtually no oxidation. The iron-storage disease hemochromatosis exhibits the most prominent general increase in RNA oxidation ever observed. Oxidation of RNA primarily leads to strand breaks and to oxidative base modifications. Oxidized mRNA is recognized by the ribosomes, but the oxidation results in ribosomal stalling and dysfunction, followed by decreased levels of functional protein as well as the production of truncated proteins that do not undergo proper folding and may result in protein aggregation within the cell. Ribosomal dysfunction may also signal apoptosis by p53-independent pathways. There are very few reports on interventions that reduce RNA oxidation, one interesting observation being a reduction in RNA oxidation by ingestion of raw olive oil. High urinary excretion of 8-oxo-guanosine, a biomarker for RNA oxidation, is highly predictive of death in newly diagnosed type 2 diabetics; this demonstrates the clinical relevance of RNA oxidation. Taken collectively the available data suggest that RNA oxidation is a contributing factor in several diseases such as diabetes, hemochromatosis, heart failure, and β-cell destruction. The mechanism involves free iron and hydrogen peroxide from mitochondrial dysfunction that together lead to RNA oxidation that in turn gives rise to truncated proteins that may cause aggregation. Thus RNA oxidation may well be an important novel contributing mechanism for several diseases.
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Affiliation(s)
- Henrik E Poulsen
- Laboratory of Clinical Pharmacology Q7642, Rigshospitalet, DK-2100 Copenhagen, Denmark.
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Feng X, Shaker M, Clark R, Tonnesen M. 355 Fibrin and type I collagen 3D matrix differentially regulate sprout angiogenesis of human dermal microvascular endothelial cells. EJC Suppl 2010. [DOI: 10.1016/s1359-6349(10)71156-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Larsen L, Tonnesen M, Ronn SG, Størling J, Jørgensen S, Mascagni P, Dinarello CA, Billestrup N, Mandrup-Poulsen T. Inhibition of histone deacetylases prevents cytokine-induced toxicity in beta cells. Diabetologia 2007; 50:779-89. [PMID: 17265033 DOI: 10.1007/s00125-006-0562-3] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2006] [Accepted: 10/30/2006] [Indexed: 01/24/2023]
Abstract
AIMS/HYPOTHESIS The immune-mediated elimination of pancreatic beta cells in type 1 diabetes involves release of cytotoxic cytokines such as IL-1beta and IFNgamma, which induce beta cell death in vitro by mechanisms that are both dependent and independent of nitric oxide (NO). Nuclear factor kappa B (NFkappaB) is a critical signalling molecule in inflammation and is required for expression of the gene encoding inducible NO synthase (iNOS) and of pro-apoptotic genes. NFkappaB has recently been shown to associate with chromatin-modifying enzymes histone acetyltransferases and histone deacetylases (HDAC), and positive effects of HDAC inhibition have been obtained in several inflammatory diseases. Thus, the aim of this study was to investigate whether HDAC inhibition protects beta cells against cytokine-induced toxicity. MATERIALS AND METHODS The beta cell line, INS-1, or intact rat islets were precultured with HDAC inhibitors suberoylanilide hydroxamic acid or trichostatin A in the absence or presence of IL-1beta and IFNgamma. Effects on insulin secretion and NO formation were measured by ELISA and Griess reagent, respectively. iNOS levels and NFkappaB activity were measured by immunoblotting and by immunoblotting combined with electrophoretic mobility shift assay, respectively. Viability was analysed by 3-(4,5-dimethyldiazol-2-yl)-2,5-diphenyl-tetrazolium bromide and apoptosis by terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) assay and histone-DNA complex ELISA. RESULTS HDAC inhibition reduced cytokine-mediated decrease in insulin secretion and increase in iNOS levels, NO formation and apoptosis. IL-1beta induced a bi-phasic phosphorylation of inhibitor protein kappa Balpha (IkappaBalpha) with the 2nd peak being sensitive to HDAC inhibition. No effect was seen on IkappaBalpha degradation and NFkappaB DNA binding. CONCLUSIONS/INTERPRETATION HDAC inhibition prevents cytokine-induced beta cell apoptosis and impaired beta cell function associated with a downregulation of NFkappaB transactivating activity.
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Affiliation(s)
- L Larsen
- Steno Diabetes Center, 2 Niels Steensens Vej, 2820, Gentofte, Denmark
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Størling J, Binzer J, Andersson AK, Züllig RA, Tonnesen M, Lehmann R, Spinas GA, Sandler S, Billestrup N, Mandrup-Poulsen T. Nitric oxide contributes to cytokine-induced apoptosis in pancreatic beta cells via potentiation of JNK activity and inhibition of Akt. Diabetologia 2005; 48:2039-50. [PMID: 16132952 DOI: 10.1007/s00125-005-1912-2] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2005] [Accepted: 05/19/2005] [Indexed: 10/25/2022]
Abstract
AIMS/HYPOTHESIS Pro-inflammatory cytokines cause beta cell secretory dysfunction and apoptosis--a process implicated in the pathogenesis of type 1 diabetes. Cytokines induce the expression of inducible nitric oxide (NO) synthase (iNOS) leading to NO production. NO contributes to cytokine-induced apoptosis, but the underlying mechanisms are unclear. The aim of this study was to investigate whether NO modulates signalling via mitogen-activated protein kinases (MAPKs) and Akt. MATERIALS AND METHODS MAPK activities in INS-1 cells and isolated islets were determined by immunoblotting and in vitro kinase assay. Apoptosis was determined by ELISA measurement of histone-DNA complexes present in cytoplasm. RESULTS Apoptosis in INS-1 cells induced by IL-1beta plus IFNgamma was dependent on NO production as demonstrated by the use of the NOS blocker NG-methyl-L-arginine. Accordingly, an NO donor (S-nitroso-N-acetyl-D, L-penicillamine, SNAP) dose-dependently caused apoptosis in INS-1 cells. SNAP activated c-Jun N-terminal kinase (JNK) and p38 MAPK, but suppressed the activity of extracellular signal-regulated kinase MAPK. In rat islets, NOS inhibition decreased JNK and p38 activities induced by a 6-h exposure to IL-1beta. Likewise, IL-1beta-induced JNK and p38 activities were lower in iNOS(-/-) mouse islets than in wild-type islets. In human islets, SNAP potentiated IL-1beta-induced JNK activation. The constitutive level of active, Ser473-phosphorylated Akt in INS-1 cells was suppressed by SNAP. IGF-I activated Akt and protected against SNAP-induced apoptosis. The anti-apoptotic effect of IGF-I was not associated with reduced JNK activation. CONCLUSIONS/INTERPRETATION We suggest that NO contributes to cytokine-induced apoptosis via potentiation of JNK activity and suppression of Akt.
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Affiliation(s)
- J Størling
- Laboratory for Beta Cell Biology, Steno Diabetes Center, Gentofte, Denmark.
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Cardozo AK, Ortis F, Storling J, Feng YM, Rasschaert J, Tonnesen M, Van Eylen F, Mandrup-Poulsen T, Herchuelz A, Eizirik DL. Cytokines downregulate the sarcoendoplasmic reticulum pump Ca2+ ATPase 2b and deplete endoplasmic reticulum Ca2+, leading to induction of endoplasmic reticulum stress in pancreatic beta-cells. Diabetes 2005; 54:452-61. [PMID: 15677503 DOI: 10.2337/diabetes.54.2.452] [Citation(s) in RCA: 410] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Cytokines and free radicals are mediators of beta-cell death in type 1 diabetes. Under in vitro conditions, interleukin-1beta (IL-1beta) + gamma-interferon (IFN-gamma) induce nitric oxide (NO) production and apoptosis in rodent and human pancreatic beta-cells. We have previously shown, by microarray analysis of primary beta-cells, that IL-1beta + IFN-gamma decrease expression of the mRNA encoding for the sarcoendoplasmic reticulum pump Ca(2+) ATPase 2b (SERCA2b) while inducing expression of the endoplasmic reticulum stress-related and proapoptotic gene CHOP (C/EBP [CCAAT/enhancer binding protein] homologous protein). In the present study we show that cytokine-induced apoptosis and necrosis in primary rat beta-cells and INS-1E cells largely depends on NO production. IL-1beta + IFN-gamma, via NO synthesis, markedly decreased SERCA2b protein expression and depleted ER Ca(2+) stores. Of note, beta-cells showed marked sensitivity to apoptosis induced by SERCA blockers, as compared with fibroblasts. Cytokine-induced ER Ca(2+) depletion was paralleled by an NO-dependent induction of CHOP protein and activation of diverse components of the ER stress response, including activation of inositol-requiring ER-to-nucleus signal kinase 1alpha (IRE1alpha) and PRK (RNA-dependent protein kinase)-like ER kinase (PERK)/activating transcription factor 4 (ATF4), but not ATF6. In contrast, the ER stress-inducing agent thapsigargin triggered these four pathways in parallel. In conclusion, our results suggest that the IL-1beta + IFN-gamma-induced decrease in SERCA2b expression, with subsequent depletion of ER Ca(2+) and activation of the ER stress pathway, is a potential contributory mechanism to beta-cell death.
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Affiliation(s)
- Alessandra K Cardozo
- Laboratory of Experimental Medicine, Université Libre de Bruxelles, Route de Lennik, 808 CP-618, 1070 Brussels, Belgium.
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Haapasalmi K, Zhang K, Tonnesen M, Olerud J, Sheppard D, Salo T, Kramer R, Clark RA, Uitto VJ, Larjava H. Keratinocytes in human wounds express alpha v beta 6 integrin. J Invest Dermatol 1996; 106:42-8. [PMID: 8592080 DOI: 10.1111/1523-1747.ep12327199] [Citation(s) in RCA: 115] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Cell adhesion receptors of the integrin family play a major role during re-epithelialization of human wounds. We have previously documented that the expression of alpha v family integrins is induced in keratinocytes of mucosal wounds [1]. In the present investigation, we extended these studies to determine whether alpha v beta 6 integrin is expressed during wound healing in humans. Mucosal and epidermal wound sections from 1- to 7-day-old wounds were used for immunolocalization of integrins and their putative ligands. In addition, freshly isolated epidermal keratinocytes were used to study integrin expression in vitro. Expression of alpha v beta 6 integrin appeared relatively late during mucosal and dermal wound healing. Maximal expression was seen in 7-day-old wounds in which epithelial sheets had fused and granulation tissue was present. Fibronectin and tenascin, both possible ligands for alpha v beta 6 integrin, were found concentrated underneath the basal epithelial cells expressing this receptor, and the maximal expression of tenascin coincided with that of alpha v beta 6 integrin. Freshly isolated epidermal keratinocytes did not stain for alpha v beta 6 integrin but began to express this integrin after subculturing. Our results suggest that the expression of alpha v beta 6 integrin, a putative binding integrin for fibronectin and tenascin, is induced in keratinocytes when epithelial sheets fuse during wound healing.
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Affiliation(s)
- K Haapasalmi
- Department of Oral Biology, University of British Columbia, Vancouver, Canada
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