Professor Ann Simpson
Head of School, Medical and Molecular Biosciences, School of Medical and Molecular Biosciences
BSc (Hons) (Syd), PhD (Syd)
Email: Ann.Simpson@uts.edu.au
Phone: +61 2 9514 4097
Fax: +61 2 9514 8206
Room: CB04.06.39B (map)
Mailing address: PO Box 123,
Broadway NSW 2007,
Australia
Biography
Professor Simpson has a BSc (Hons) and a PhD (Veterinary Science) from the University of Sydney.
Professor Simpson joined the staff at UTS in 1994 and since 2002 has held the position of Professor of Biochemistry in the Department of Medical & Molecular Biosciences and since July 2009 has been Head of that Department.
She has also been Director of the Research Centre for Health Technologies since 2006. Prior to coming to UTS she was a Postdoctoral Fellow at both the University of Sydney and the University of New South Wales.
At UTS Prof. Simpson is involved in teaching final year Science students Biochemistry and Molecular Biology.
Her current research interest is the gene therapy of diabetes mellitus. Specifically, her research is concerned with investigating the possibility of engineering an artificial insulin-producing cell to replace the insulin-secreting beta cells that have been destroyed by the autoimmune process in Type I diabetics.
The principle behind this approach is that non-pancreatic cells can be genetically altered to produce, store and secrete insulin to physiological stimuli such as glucose.
Her laboratory has a Research Fellow, a Research Assistant and Postgraduate students. Since joining UTS she has received research funding from organizations such as the NHMRC, ARC, Juvenile Diabetes Research Foundation, Australian Diabetes Research Trust, Roche Organ Transplant Research Foundation, Rebecca Cooper Foundation, Ramiciotti Research Foundation and commercial sources.
She has collaborations with Dr. Bronwyn O'Brien and Najah Nassif in MMB, Dr. Wayne Hawthorne at Westmead Hospital, Dr. Ian Alexander at Westmead Children's Hospital and Dr. John Feller at the Royal Hospital, Randwick.
International collaborations include Sir Roy Calne and Prof. Andrew Lever, Cambridge University, Prof. Dick White, Nottingham University, Prof. Lee Kok Onn and Dr. Shu Vin Gan, National University of Singapore and a commercial relationship with Austrianova Singapore.
Professional
1. Endocrine Society of Australia: 1987 to present.
2. Australian Diabetes Society; 1987 to present.
3. Transplantation Society of Australia and New Zealand: 1989 to present.
4. International Transplantation Society; 1989 to present.
5. Cell Transplant Society, Foundation Member: 1991 to present.
6. Juvenile Diabetes Foundation International: 1991 to present.
7. Juvenile Diabetes Foundation of Australia: 1993 to present.
8. Australian Society of Clinical Biochemists: 1995 to present.
9. International Islet & Pancreas Transplantation Society: 1995 to present.
10. Australasian Gene Therapy Society: 2001 to present, founding member Professor Simpson is also the founding Chair of the UTS Biosafety Committee and Inaugural Treasurer of the Australasian Gene Therapy Society and is a Fellow and Board member of the Australian College of Biomedical Scientists.
Teaching areas
Prof. Simpson co-ordinates Medical & Diagnostic Biochemistry (91344) and Biochemistry, Genes and Disease (91345), both of which are third year subjects in the B. BIomed. Sci., Med. Sci, B. Biotech and the BSc.
Both of these subjects examine the biochemical and molecular aspects of human disease and examine how the diseases are diagnosed in a clinical biochemistry laboratory and treated by clinicians. She also gives specialist lectures in Molecular Biology II on gene therapy and transgenics.
Research
Research interests
Specifically, Prof. Simpson's research is concerned with investigating the possibility of engineering an liver cells to replace the beta cells that have been destroyed by the autoimmune process in Type I diabetics.
The group is approaching this problem from 2 main directions:
1. The use of human liver cell lines that store and secrete insulin to glucose, which could be used to correct diabetes via transplantation of the encapsulated cells into patients, and
2. Direct delivery of the insulin gene and other components directly to the liver of patients to induce them to store mature insulin and secrete it in a physiological manner.
Recently the group has engineered a liver cell line derived that secretes insulin in the physiological range: Melligen cells. Her research with Dr. Binhai Ren and Dr. Bronwyn O'Brien has also led to reversal of diabetes in streptozotocin-diabetic immunocompetant rats and NOD mice by the direct delivery of the insulin gene directly through the portal circulation of the animal.
The animals have maintained normo-glycaemia for over 500 days with normal glucose tolerance and liver function tests. The group is moving to large animal studies.
Research supervision: Yes
Ms. Janet Lawandi (PhD): Effects of pro-inflammatory cytokines on an insulin-secreting liver cell line
Ms. Prudence Gatt (MSc): Liver to pancreas transdifferentiation following delivery of the insulin gene to the livers of diabetic mice
Projects
Selected Peer-Assessed Projects
Reversal of Diabetes in a humanised mouse
Reversal of Diabetes in Pigs using Liver-Directed Gene Therapy
Correction of diabetes in an autoimmune model using insulin-secreting liver cells
Immunological characterization and encapsulation of a bioengineered insulin secreting liver cell
Surgical Imaging System for the Treatment and Cure of Diabetes Mellitus
Use of novel retroviral vectors for transduction of primary hepatocytes with the human insulin gene
Use of as novel retroviral vector for transduction of primary hepatocytes with human insulin gene.
Publications
Journal articles
Tohidi-Esfahani, D., Graham, L., Hannan, G., Simpson, A.M. & Hill, R. 2011, 'An Ecdysone Receptor From The Pentatomomorphan, Nezara Viridula, Shows Similar Affinities For Moulting Hormones Makisterone A And 20-Hydroxyecdysone', Insect Biochemistry and Molecular Biology, vol. 41, no. 2, pp. 77-89.
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It has been suggested that Pentatomomorpha utilise the C(28) ecdysteroid, makisterone A (MakA), as the major moulting hormone rather than the more common C(27) hormone, 20-hydroxyecdsyone (20E). The present study is the first to examine this postulate at
Tohidi-Esfahani, D., Lawrence, M., Graham, L., Hannan, G., Simpson, A.M. & Hill, R. 2011, 'Isoforms Of The Heteropteran Nezara Viridula Ecdysone Receptor: Protein Characterisation, Rh5992 Insecticide Binding And Homology Modelling', Pest Management Science, vol. 67, no. 11, pp. 1457-1467.
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Abstract: BACKGROUND: Certain bisacylhydrazine compounds such as tebufenozide (RH5992) have been shown to act as order-specific insecticides. Their compatibility with predatory Heteroptera, which are used as biological control agents, has also been demonstrated. However, the molecular mode of action of these ecdysone agonists has not been explored in a heteropteran, much less one that is a significant agricultural pest, such as Nezara viridula. RESULTS: Alternatively spliced ligand-binding regions of the N. viridula ecdysone receptor were expressed, purified and characterised by 2D gel analysis, mass spectrometry, homology modelling and competitive binding of a bisacylhydrazine insecticidal compound (RH5992) and various ecdysteroids. Ligand binding by the two splice isoforms was indistinguishable, and relative affinities were found to occur in the order muristerone A > ponasterone A > 20-hydroxyecdysone > inokosterone > RH5992 > alpha-ecdysone. CONCLUSION: The predicted difference in amino acid sequence between the ligand-binding domains of the N. viridula ecdysone receptor splice variants was verified by mass spectrometry. Both splice variant isoforms exhibit a greater affinity for the bisacylhydrazine insecticide RH5992 than do the other hemipteran ecdysone receptors characterised to date. Their affinities for a range of ecdysteroids also distinguish them from the ecdysone receptors of other Hemiptera characterised thus far. Homology models of both N. viridula receptor isoforms provide further insight into the bisacylhydrazine- and ecdysteroid-binding properties of these receptors, including their similar affinity for 20-hydroxyecdysone and the postulated pentatomomorphan moulting hormonemakisterone A.
Lutherborrow, M., Appavoo, M., Simpson, A.M. & Tuch, B.E. 2009, 'Gene expression profiling of HUH7-ins Lack of a granulogenic function for Chromogranin A', Islets, vol. 1, no. 1, pp. 60-72.
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Previously, the insulin producing liver cell line HUH7-ins has been shown to synthesize, store and secrete insulin in response to glucose via secretory granules. The current study characterized the gene expression profile of HUH7-ins with the aim to identify changes possibly involved in the formation of granules. Additionally, experiments were conducted to determine the influence of chromograninA (egA) on secretory granule biogenesis (5GB) in HUH7-ins. Expression of 165 genes were significantly changed in HUH7-ins, though interestingly the majority of secretory granule associated genes, such as the chromogranins were unchanged. egA was over-expressed in glucose unresponsive HUH7-ins cells to test whether egA played a role in 5GB and would restore the regulated secretory phenotype. Over expression affected neither the storage nor regulated secretion of insulin. These data suggest that 5GB may by regulated at a post-transcriptional level with no evidence to indicate that egA regulates SGB in the cell line HUH7-ins.
Feller, J.M., Simpson, A.M., Nelson, M., Swan, M.A., O'Connell, P.J., Hawthorne, W.J., Tao, C.Z. & O'Brien, B. 2008, 'Growth-promoting effect of Rh(D) antibody on human pancreatic islet cells', Journal of Clinical Endocrinology and Metabolism, vol. 93, no. 9, pp. 3560-3567.
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Context/Objective: Hyperinsulinism with islet cell hyperplasia is a frequent complication, of unknown cause, in hemolytic disease of the newborn, occurring in Rh(D)-positive infants of Rh-isoimmunized Rh(D)-negative mothers, but not in infants with other hemolytic disorders. We investigated the possibility that trans-placentally acquired anti-D Ig is the cause of both conditions. Design: Monolayer cultures of human islet cells were exposed to sera from Rh-isoimmunized mothers and newborns, where jaundice, hyperinsulinism, and hypoglycemia in the infant had ensued. Parallel cultures with anti-D, specific anti-D monoclonal antibodies, normal human Ig (15 ++g/ml), and serum controls were also undertaken. Islet cell proliferation was determined by [ 3H]thymidine incorporation. Insulin storage and chronic and acute insulin secretion to glucose were analyzed by RIA. Rh(D) surface antigen expression was determined on islet cells by flow cytometric analysis. Results: Islet cell proliferation and insulin secretion were significantly greater in coculture with test sera (P < 0.01; n = 8) and with anti-D (P < 0.001; n = 8), compared with either controls or Ig. After 8 d of growth, the static incubation experiment showed a 3.5-fold response to glucose stimulus in all sera. Rh(D) antigen expression was detected on the islet cell surface by flow cytometry, and islet cell morphology was normal. Colocalization of the proliferation marker Ki67 with insulin by immunofluorescent staining further indicated that Rh(D) antibody promoted islet growth. Conclusions: The anti-Rh(D) islet cell proliferative effect generates neonatal hyperinsulinism in Rh isoimmunization. Anti-Rh(D) may have application for islet cell proliferation in diabetes mellitus treatment for Rh(D)-positive subjects. Further analysis is required. Copyright ® 2008 by The Endocrine Society.
O'Brien, B., Archer, N.S., Simpson, A.M., Torpy, F.R. & Nassif, N. 2008, 'Association of SLC11A1 promoter polymorphisms with the incidence of autoimmune and inflammatory diseases: A meta-analysis', Journal Of Autoimmunity, vol. 31, no. 1, pp. 42-51.
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Solute carrier family 11 member a1 (SLC11A1) exerts pleiotropic effects on macrophage function. Expression of SLC11A1 is regulated by a (GT)(n) microsatellite promoter repeat polymorphism of which nine alleles have been described. Enhanced activation of
Mccann, L., Haywood, M., Ren, B., Simpson, A.M., Guilhaus, M., Wasinger, V., Raftery, M.J. & Davey, R.A. 2007, 'Identification Of Vascular Surface Proteins By In Vivo Biotinylation: A Method Sufficiently Sensitive To Detect Changes In Rat Liver 2 Weeks After Partial Hepatectomy', Journal Of Proteome Research, vol. 6, no. 8, pp. 3108-3113.
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We have developed a methodology to selectively isolate and identify proteins associated with the luminal surface of blood vessels using in vivo biotinylation, streptavidin-affinity chromatography, and SDS-PAGE/LC-MS/MS. This had sufficient sensitivity to
Ren, B., O'Brien, B., Swan, M.A., Koina, M.E., Nassif, N., Wei, M.Q. & Simpson, A.M. 2007, 'Long-term Correction Of Diabetes In Rats After Lentiviral Hepatic Insulin Gene Therapy', Diabetologia, vol. 50, no. 9, pp. 1910-1920.
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Aims/hypothesis Type 1 diabetes results from the autoimmune destruction of pancreatic beta cells. Exogenous insulin therapy cannot achieve precise physiological control of blood glucose concentrations, and debilitating complications develop. Lentiviral v
Liu, G.J., Simpson, A.M., Swan, M.A., Tao, C.Z., Tuch, B.E., Crawford, R.M., Jovanovic, A. & Martin, D.K. 2003, 'ATP-sensitive potassium channels induced in liver cells after transfection with insulin cDNA and the GLUT2 transporter regulate glucose-stimulated insulin secretion', Faseb Journal, vol. 17, no. 10, pp. 1-21.
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Tuch, B.E., Szymanska, B., Yao, M., Tabiin, M.T., Gross, D.J., Holman, S., Swan, M.A., Humphrey, R., Marshall, G.M. & Simpson, A.M. 2003, 'Function of a genetically modified human liver cell line that stores, processes and secretes insulin', Gene Therapy, vol. 10, no. 6, pp. 490-503.
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Bai, L., Tuch, B.E., Hering, B.J. & Simpson, A.M. 2002, 'Fetal pig beta cells are resistant to the toxic effects of human cytokines', Transplantation, vol. 73, no. N/A, pp. 714-722.
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Humphrey, R., Smith, M.S., Kwok, J., Tuch, B.E., Si, Z. & Simpson, A.M. 2001, 'In Vitro Dedifferentiation of Fetal Porcine Pancreatic Tissue Prior to transplantation as islet-Like Cell Clusters', Cells Tissues Organs, vol. 168, no. 3, pp. 158-169.
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Tabiin, M.T., Tuch, B.E., Bai, L., Simpson, A.M. & Han, X. 2001, 'Susceptibility of Insulin-Secreting Hepatocytes to the Toxicity of Pro-Inflammatory Cytokines', Journal of Autoimmunity, vol. 17, no. 3, pp. 229-242.
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The liver has been suggested as a suitable target organ for reversing type I diabetes by gene therapy. Whilst gene delivery systems to the hepatocyte have yet to be optimized in vivo, whether insulin-secreting hepatocytes are resistant to the autoimmune process that kills pancreatic -cells has never been addressed. One of the mechanisms by which -cells are killed in type I diabetes is by the release of the cytokines interleukin-1 (IL-1 ), tumour necrosis factor- (TNF- ) and interferon- (IFN- ) by immune cells. To test the effect of the cytokines on insulin-secreting hepatocytes in vitro we exposed the betacyte, also called the HEP G2ins/g cell which possesses cytokine receptors and can synthesize, store and secrete insulin in a regulated fashion to a glucose stimulus, to the above mentioned cytokines for 14 days. Viability of the HEP G2ins/g cells was similar to that of other liver cell lines/primary cells which were more resistant to the cytokines than the -cell line NIT-1. The cytokines had no adverse effect for the first six days on insulin secretion, content and mRNA levels of the HEP G2ins/g cells and insulin secretion in response to 1-h exposure to 20 mM glucose was enhanced 14-fold. Our results indicate that genetically engineered hepatocytes and primary liver cells are more resistant than pancreatic -cells to the adverse effects of cytokines offering hope that insulin secreting hepatocytes in vivo made by gene therapy are less likely to be destroyed by cytokines released during autoimmune destruction.
Vo, L., Tuch, B.E., Wright, D.C., Keogh, G.W., Simpson, A.M., Roberts, S., Yao, M., Tabiin, M.T., Valencia, S.K. & Scott, H. 2001, 'Lowering of Blood Glucose to Nondiabetic Levels in a Hyperglycemic Pig By Allografting of Fetal Pig Isletlike Cell Clusters', Transplantation, vol. 71, no. 11, pp. 1671-1677.
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Tasevski, V., Benn, D., King, M., Luttrell, B. & Simpson, A.M. 2000, 'Mitogenic Effect of Lithium in FRTL-5 Cells can be Reversed by Blocking De Novo Cholesterol Synthesis and Subsequent Signal Transduction', Thyroid, vol. 10, no. 4, pp. 305-311.
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Lithium therapy is the therapeutic mainstay for bipolar disorder and has been associated in the thyroid with euthymic goiter, hyper and hypothyroidism as well as thyroid autoimmune disease. The FRTL-5 cell line is a well known model of thyroid cell physiology, where lithium has been shown to increase 3H-thymidine uptake at concentrations of 2 mM. This mitogenic effect was not associated with adenylate cyclase as measured by cyclic adenosine monophosphate (cAMP) production. The de novo synthesis of cholesterol is an important signal transduction pathway in FRTL-5 cells, where newly synthesized Rho GTPase is geranylgeranylated, enabling membrane localization of the G-protein and subsequent G1 to S-phase transition, resulting from extracellular stimulation. Here we confirm lithium mitogenicity at therapeutically relevant concentrations (1 mM) and demonstrate a lithium-associated accumulation of FRTL-5 cells in S-phase of the cell cycle. These effects could be abolished by Pravastatin, a potent inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA), the rate-limiting enzyme in the formation of intermediates (de novo cholesterol synthesis) required for G-protein prenylation. Pravastatin, similar to lithium, showed no effect on cAMP production either under basal or thyroid stimulating hormone (TSH)-stimulated conditions indicating that de novo cholesterol synthesis is not involved with adenylate cyclase. The inhibitory effect of pravastatin could be overcome by reinitiating de novo cholesterol synthesis. This was achieved by the addition of the cell permeable, first metabolite (mevalonate) after HMG-CoA, which allowed the cycle to continue, leading eventually to protein prenylation, despite the presence of Pravastatin. These novel findings demonstrate lithium involvement in de novo cholesterol synthesis and G-protein prenylation, an important signal transduction pathway in FRTL-5 cells.
Simpson, A.M. & White, I.G. 1988, 'Measurement and manipulation of cytoplasmic free calcium of ram and boar spermatozoa using quin 2', Cell calcium, vol. 9, no. 1, pp. 45-56.
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The highly selective fluorescent Ca2+ indicator `quin 2+ has been loaded into ram and boar spermatozoa as the acetoxymethyl ester, `quin 2/AM+, which is hydrolysed and trapped in the cytoplasm. Loadings of several mM were not toxic to spermatozoa as judged by motility. Fluorescence measurements (mean + S.E.M.) indicated a normal cytoptasmic free-calcium concentration, [Ca2+]i, of 193nM f 0.2 (n= 10) for ejaculated ram sperm, 175nM 5 3.9 (n= 10) for cauda epididymal boar sperm and 105nM `_ 10 (n= 10) for the caput sperm. After cold shock ejaculated mm and cauda epididymal boar sperm did not retain quin 2, due presumably to structural damage. However, cold shocked caput boar sperm could be readily loaded with quin 2 and had a [Ca2+]i similar to control sperm.
Simpson, A.M., Swan, M.A. & White, I.G. 1987, 'Calcium uptake, respiration, and ultrastructure of sperm exposed to ionophore A23187', Archives of Andrology, vol. 19, pp. 5-18.
Simpson, A.M. & White, I.G. 1987, 'Interrelationships between motility, c-AMP, respiration and calcium uptake of ram and boar sperm', Animal Reproduction Science, vol. 15, no. 3-4, pp. 189-207.
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Uptake of radioactive calcium by washed ejaculated ram and epididymal boar spermatozoa was inhibited by theophylline and dibutyryl cyclic AMP (diBc-AMP) which increases cyclic AMP (c-AMP) levels in cells, by the uncouplers 2,4-dinitrophenol (2,4-DNP) and carbonylcyanide m-chlorophenylhydrazone (CCP), by sodium azide, rotenone and antimycin A and by ruthenium red and La3+. Nicotine, eserine and ouabain stimulated the calcium uptake of caput boar sperm and decamethonium inhibited it. Inhibition of calcium uptake was accompanied by a decrease in oxygen uptake in the case of the metabolic inhibitors (rotenone, antimycin A and sodium azide) and substances that interfere with cell calcium transport (ruthenium red and La3+). Respiration was increased in the presence of 2,4-DNP and CCP, and theophylline and diBc-AMP. The phosphodiesterase inhibitors (caffeine and theophylline), diBc-AMP, 2,4-DNP, bicarbonate ion and ouabain increased the motility of caput boar sperm. Most other substances depressed motility. The ionophore A23187 severely inhibited the motility of ram and boar sperm with an accompanying increase in their calcium and oxygen uptake which was largely unaffected by addition of inhibitors, activators and surfactants. This may be explained by the operation of competing mitochondrial and plasma membrane pumps. However, a selective increase in the permeability of the sperm plasma membrane on addition of the polyene antibiotic filipin released calcium accumulated in the presence of A23187. This provides further evidence for the lack of mitochondrial involvement in the influx of calcium produced by the ionophore.
Simpson, A.M., White, I.G. 1986, 'Effect of cold shock and cooling rate on calcium uptake of ram spermatozoa', Animal Reproduction Science, vol. 12, no. 2, pp. 131-143.
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Rapid cooling (cold shock) of washed ejaculated ram sperm irreversibly reduced motility and respiration and greatly increased uptake of 4sCa2+. The effect was greater as the temperature of cooling was reduced from 15¦C to 0¦C, and a substantial increase in sperm calcium levels was even observed after slow cooling to temperatures below 10¦C. The rise in calcium uptake on freezing sperm to -79¦C was not as great as that on cold shocking sperm to 0¦C. Inactivation of sperm by mild heat (50¦C) had no significant effect on calcium uptake but subsequent cold shock increased the sperm calcium. Reverse immobilization of sperm by low concentrations of formaldehyde significantly reduced calcium uptake on cold shock. Addition of detergents to sperm immediately reduced motility, respiration and calcium uptake of control and cold-shocked sperm to zero.
