Abstract
Pituitary adenylate cyclase activating polypeptide (PACAP) is a neurotrophic and neuroprotective peptide that has been shown to exert protective effects in different neuronal injuries, such as retinal degenerations. Diabetic retinopathy (DR), the most common complication of diabetes, affects the microvasculature and neuronal architecture of the retina. We have proven earlier that PACAP is also protective in a rat model of DR. In this study, streptozotocin-induced DR was treated with intravitreal PACAP administration in order to further analyze the synaptic structure and proteins of PACAP-treated diabetic retinas, primarily in the vertical information processing pathway. Streptozotocin-treated Wistar rats received intravitreal PACAP injection three times into the right eye 2 weeks after the induction of diabetes. Morphological and molecular biological (qRT-PCR; Western blot) methods were used to analyze retinal synapses (ribbons, conventional) and related structures. Electron microscopic analysis revealed that retinal pigment epithelium, the ribbon synapses and other synaptic profiles suffered alterations in diabetes. However, in PACAP-treated diabetic retinas more bipolar ribbon synapses were found intact in the inner plexiform layer than in DR animals. The ribbon synapse was marked with C-terminal binding protein 2/Bassoon and formed horseshoe-shape ribbons, which were more retained in PACAP-treated diabetic retinas than in DR rats. These results are supported by molecular biological data. The selective degeneration of related structures such as bipolar and ganglion cells could be ameliorated by PACAP treatment. In summary, intravitreal administration of PACAP may have therapeutic potential in streptozotocin-induced DR through maintaining synapse integrity in the vertical pathway.
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References
Aizu Y, Oyanagi K, Hu J, Nakagawa H (2002) Degeneration of retinal neuronal processes and pigment epithelium in the early stage of the streptozotocin-diabetic rats. Neuropathology 22(3):161–170. doi:10.1046/j.1440-1789.2002.00439.x
Athanasiou D, Aguila M, Bevilacqua D, Novoselov SS, Parfitt DA, Cheetham ME (2013) The cell stress machinery and retinal degeneration. FEBS Lett 587(13):2008–2017. doi:10.1016/j.febslet.2013.05.020
Atlasz T, Szabadfi K, Kiss P, Racz B, Gallyas F, Tamas A, Gaal V, Zs Marton, Gabriel R, Reglodi D (2010) Pituitary adenylate cyclase activating polypeptide in the retina: focus on the retinoprotective effects. Ann N Y Acad Sci 1200:128–139. doi:10.1111/j.1749-6632.2010.05512.x
Banki E, Kovacs K, Nagy D, Juhasz T, Degrell P, Csanaky K, Kiss P, Jancso G, Toth G, Tamas A, Reglodi D (2014) Molecular mechanisms underlying the Nephroprotective effects of PACAP in diabetes. J Mol Neurosci 54(3):300–309. doi:10.1007/s12031-014-0249-z
Baptista FI, Gaspar JM, Cristovao A, Santos PF, Kofalvi A, Ambrosio AF (2011) Diabetes induces early transient changes in the content of vesicular transporters and no major effects in neurotransmitter release in hippocampus and retina. Brain Res 1383:257–269. doi:10.1016/j.brainres.2011.01.071
Barber AJ, Lieth E, Khin SA, Antonetti DA, Buchanan AG, Gardner TW (1998) Neural apoptosis in the retina during experimental and human diabetes. Early onset and effect of insulin. J Clin Invest 102(4):783–791. doi:10.1172/JCI2425
Barber AJ, Antonetti DA, Kern TS, Reiter CE, Soans RS, Krady JK, Levison SW, Gardner TW, Bronson SK (2005) The Ins2Akita mouse as a model of early retinal complications in diabetes. Invest Ophthalmol Vis Sci 46(6):2210–2218. doi:10.1167/iovs.04-1340
Barber AJ, Gardner TW, Abcouwer SF (2011) The significance of vascular and neural apoptosis to the pathology of diabetic retinopathy. Invest Ophthalmol Vis Sci 52(2):1156–1163. doi:10.1167/iovs.10-6293
Brandstatter JH, Fletcher EL, Garner CC, Gundelfinger ED, Wassle H (1999) Differential expression of the presynaptic cytomatrix protein bassoon among ribbon synapses in the mammalian retina. Eur J Neurosci 11(10):3683–3693. doi:10.1046/j.1460-9568.1999.00793.x
Brown D, Tamas A, Reglodi D, Tizabi Y (2014) PACAP protects against inflammatory-mediated toxicity in dopaminergic SH-SY5Y cells: implication for Parkinson’s disease. Neurotox Res 26(3):230–239. doi:10.1007/s12640-014-9468-x
Castorina A, Giunta S, Mazzone V, Cardile V, D’Agata V (2010) Effects of PACAP and VIP on hyperglycemia-induced proliferation in murine microvascular endothelial cells. Peptides 31(12):2276–2283. doi:10.1016/j.peptides.2010.08.013
Cavallaro S, D’Agata V, Drago F, Musco S, Nuciforo G, Ricciardolo F, Travali S, Stivala F, Arimura A, Canonico PL (1996) Ocular expression of type-I pituitary adenylate cyclase-activating polypeptide (PACAP) receptors. Ann N Y Acad Sci 805:555–557
Chen F, Zhang HQ, Zhu J, Liu KY, Cheng H, Li GL, Xu S, Lv WH, Xie ZG (2012) Puerarin enhances superoxide dismutase activity and inhibits RAGE and VEGF expression in retinas of STZ-induced early diabetic rats. Asian Pac J Trop Med 5(11):891–896. doi:10.1016/S1995-7645(12)60166-7
Chen M, Curtis TM, Stitt AW (2013) Advanced glycation end products and diabetic retinopathy. Curr Med Chem 20(26):3234–3240. doi:10.2174/09298673113209990025
Cloherty EK, Diamond DL, Heard KS, Carruthers A (1996) Regulation of GLUT1-mediated sugar transport by an antiport/uniport switch mechanism. Biochemistry 35(40):13231–13239. doi:10.1021/bi961208t
Cuenca N, Fernández-Sánchez L, Campello L, Maneu V, De la Villa P, Lax P, Pinilla I (2014) Cellular responses following retinal injuries and therapeutic approaches for neurodegenerative diseases. Prog Retin Eye Res 43:17–75. doi:10.1016/j.preteyeres.2014.07.001
D’Agata V, Cavallaro S (1998) Functional and molecular expression of PACAP/VIP receptors in the rat retina. Brain Res Mol Brain Res 54:161–164
D’Alessandro A, Cervia D, Catalani E, Gevi F, Zolla L, Casini G (2014) Protective effects of the neuropeptides PACAP, substance P and the somatostatin analogue octreotide in retinal ischemia: a metabolomic analysis. Mol BioSyst 10(6):1290–1304. doi:10.1039/c3mb70362b
D’Amico AG, Maugeri G, Reitano R, Bucolo C, Saccone S, Drago F, D’Agata V (2015) PACAP modulates expression of hypoxia-inducible factors in streptozotocin-induced diabetic rat retina. J Mol Neurosci 57(4):501–509. doi:10.1007/s12031-015-0621-7
D’Cruz TS, Weibley BN, Kimball SR, Barber AJ (2012) Post-translational processing of synaptophysin in the rat retina is disrupted by diabetes. PLoS One 7(9):e44711. doi:10.1371/journal.pone.0044711
Dick O, tom Dieck S, Altrock WD, Ammermuller J, Weiler R, Garner CC, Gundelfinger ED, Brandstatter JH (2003) The presynaptic active zone protein bassoon is essential for photoreceptor ribbon synapse formation in the retina. Neuron 37(5):775–786. doi:10.1016/S0896-6273(03)00086-2
Dvorakova MC, Pfeil U, Kuncova J, Sviglerova J, Galvis G, Krasteva G, Konig P, Grau V, Slavikova J, Kummer W (2006) Down-regulation of vasoactive intestinal peptide and altered expression of its receptors in rat diabetic cardiomyopathy. Cell Tissue Res 323(3):383–393. doi:10.1007/s00441-005-0001-7
Elshatory Y, Deng M, Xie X, Gan L (2007) Expression of the LIM-homeodomain protein Isl1 in the developing and mature mouse retina. J Comp Neurol 503(1):182–197. doi:10.1002/cne.21390
Engerman RL, Kern TS (1995) Retinopathy in animal models of diabetes. Diabetes Metab Rev 11(2):109–120
Énzsöly A, Szabó A, Kántor O, Dávid C, Szalay P, Szabó K, Szél Á, Németh J, Lukáts Á (2014) Pathologic alterations oft he outer retina in streptzotocin-induced diabetes. Invest Ophthalmol Vis Sci 55(6):3686–3699. doi:10.1167/iovs.13-13562
Gaspar JM, Baptista FI, Galvao J, Castilho AF, Cunha RA, Ambrosio AF (2010) Diabetes differentially affects the content of exocytotic proteins in hippocampal and retinal nerve terminals. Neuroscience 169(4):1589–1600. doi:10.1016/j.neuroscience.2010.06.021
Gastinger MJ, Singh RS, Barber AJ (2006) Loss of cholinergic and dopaminergic amacrine cells in streptozotocin-diabetic rat and Ins2Akita-diabetic mouse retinas. Invest Ophthalmol Vis Sci 47(7):3143–3150. doi:10.1167/iovs.05-1376
Giunta S, Castorina A, Bucolo C, Magro G, Drago F, D’Agata V (2012) Early changes in pituitary adenylate cyclase-activating peptide, vasoactive intestinal peptide and related receptors expression in retina of streptozotocin-induced diabetic rats. Peptides 37(1):32–39. doi:10.1016/j.peptides.2012.06.004
Goh SY, Cooper ME (2008) Clinical review: the role of advanced glycation end products in progression and complications of diabetes. J Clin Endocrinol Metab 93(4):1143–1152. doi:10.1210/jc.2007-1817
Hammes HP (2013) Optimal treatment of diabetic retinopathy. Ther Adv Endocrinol Metab 4(2):61–71. doi:10.1177/2042018813477886
Hammes HP, Federoff HJ, Brownlee M (1995) Nerve growth factor prevents both neuroretinal programmed cell death and capillary pathology in experimental diabetes. Mol Med 1(5):527–534
Hildebrand JD, Soriano P (2002) Overlapping and unique roles for C-terminal binding protein 1 (CtBP1) and CtBP2 during mouse development. Mol Cell Biol 22(15):5296–5307. doi:10.1128/MCB.22.15.5296-5307.2002
Ibrahim AS, El-Remessy AB, Matragoon S, Zhang W, Patel Y, Khan S, Al-Gayyar MM, El-Shishtawy MM, Liou GI (2011) Retinal microglial activation and inflammation induced by amadori-glycated albumin in a rat model of diabetes. Diabetes 60(4):1122–1133. doi:10.2337/db10-1160
Kern TS, Barber AJ (2008) Retinal ganglion cells in diabetes. J Physiol 586(18):4401–4408. doi:10.1113/jphysiol.2008.156695
Kim SW, Lim CM, Kim JB, Shin JH, Lee S, Lee M, Lee JK (2011) Extracellular HMGB1 released by NMDA treatment confers neuronal apoptosis via RAGE-p38 MAPK/ERK signaling pathway. Neurotox Res 20(2):159–169. doi:10.1007/s12640-010-9231-x
Koch S, Nusrat A (2009) Dynamic regulation of epithelial cell fate and barrier function by intercellular junctions. Ann N Y Acad Sci 1165:220–227. doi:10.1111/j.1749-6632.2009.04025.x
Kohzaki K, Vingrys AJ, Bui BV (2008) Early inner retinal dysfunction in streptozotocin-induced diabetic rats. Invest Ophthalmol Vis Sci 49(8):3595–3604. doi:10.1167/iovs.08-1679
Kumagai AK (1999) Glucose transport in brain and retina: implications in the management and complications of diabetes. Diabetes Metab Res Rev 15(4):261–673. doi:10.1002/(SICI)1520-7560(199907/08)15:4<261:AID-DMRR43>3.0.CO;2-Z
Kumagai AK, Glasgow BJ, Pardridge WM (1994) GLUT1 glucose transporter expression in the diabetic and nondiabetic human eye. Invest Ophthalmol Vis Sci 35(6):2887–2894
Lakk M, Szabó B, Völgyi B, Gábriel R, Dénes V, Dénes V (2012) Development-related splicing regulates pituitary adenylate cyclase-activating polypeptide (PACAP) receptors in the retina. Invest Ophthalmol Vis Sci 53(12):7825–7832. doi:10.1167/iovs.12-10417
Logvinov SV, Plotnikov MB, Zhdankina AA, Smolyakova VI, Ivanov IS, Kuchin AV, Chukicheva IV, Varakuta EY (2010) Morphological changes in retinal neurons in streptozotocin-induced diabetes mellitus and their correction with an isobornylphenol derivative. Neurosci Behav Physiol 40(7):779–782. doi:10.1007/s11055-010-9326-0
Lu L, Seidel CP, Iwase T, Stevens RK, Gong YY, Wang X, Hackett SF, Campochiaro PA (2013) Suppression of GLUT1; a new strategy to prevent diabetic complications. J Cell Physiol 228(2):251–257. doi:10.1002/jcp.24133
Luo D, Fan Y, Xu X (2012) The effects of aminoguanidine on retinopathy in STZ-induced diabetic rats. Bioorg Med Chem Lett 22(13):4386–4390. doi:10.1016/j.bmcl.2012.04.130
Merriman-Smith R, Donaldson P, Kistler J (1999) Differential expression of facilitative glucose transporters GLUT1 and GLUT3 in the lens. Invest Ophthalmol Vis Sci 40(13):3224–3230
Metz VV, Kojro E, Rat D, Postina R (2012) Induction of RAGE shedding by activation of G protein-coupled receptors. PLoS One 7(7):e41823. doi:10.1371/journal.pone.0041823
Meyer-Rusenberg B, Pavlidis M, Stupp T, Thanos S (2007) Pathological changes in human retinal ganglion cells associated with diabetic and hypertensive retinopathy. Graefes Arch Clin Exp Ophthalmol 245(7):1009–1018. doi:10.1007/s00417-006-0489-x
Morrow EM, Chen CM, Cepko CL (2008) Temporal order of bipolar cell genesis in the neural retina. Neural Dev 3:2. doi:10.1186/1749-8104-3-2
Nadal-Nicolas FM, Jimenez-Lopez M, Sobrado-Calvo P, Nieto-Lopez L, Canovas-Martinez I, Salinas-Navarro M, Vidal-Sanz M, Agudo M (2009) Brn3a as a marker of retinal ganglion cells: qualitative and quantitative time course studies in naive and optic nerve-injured retinas. Invest Ophthalmol Vis Sci 50(8):3860–3868. doi:10.1167/iovs.08-3267
Ohtaki H, Nakamachi T, Dohi K, Shioda S (2008) Role of PACAP in ischemic neural death. J Mol Neurosci 36(1–3):16–25. doi:10.1007/s12031-008-9077-3
Omri S, Omri B, Savoldelli M, Jonet L, Thillaye-Goldenberg B, Thuret G, Gain P, Jeanny JC, Crisanti P, Behar-Cohen F (2010) The outer limiting membrane (OLM) revisited: clinical implications. Clin Ophthalmol 4:183–195
Parsons TD, Sterling P (2003) Synaptic ribbon: conveyor belt or safety belt? Neuron 37(3):379–382. doi:10.1016/S0896-6273(03)00062-X
Rat D, Schmitt U, Tippmann F, Dewachter I, Theunis C, Wieczerzak E, Postina R, van Leuven F, Fahrenholz F, Kojro E (2011) Neuropeptide pituitary adenylate cyclase-activating polypeptide (PACAP) slows down Alzheimer’s disease-like pathology in amyloid precursor protein-transgenic mice. FASEB J 25(9):3208–3218. doi:10.1096/fj.10-180133
Reglodi D, Kiss P, Szabadfi K, Atlasz T, Gabriel R, Horvath G, Szakaly P, Sandor B, Lubics A, Laszlo E, Farkas J, Matkovits A, Brubel R, Hashimoto H, Ferencz A, Vincze A, Helyes Z, Welke L, Lakatos A, Tamas A (2012) PACAP is an endogenous neuroprotective factor—insights from PACAP deficient mice. J Mol Neurosci 48(3):482–492. doi:10.1007/s12031-012-9762-0
Regus-Leidig H, Specht D, tom Dieck S, Brandstätter JH (2010) Stability of active zone components at the photoreceptor ribbon complex. Mol Vis 16:2690–2700
Santos JM, Mohammad G, Zhong Q, Kowluru RA (2011) Diabetic retinopathy, superoxide damage and antioxidants. Curr Pharm Biotechnol 12(3):352–361. doi:10.2174/138920111794480507
Schmitz F, Königstorfer A, Südhof TC (2000) RIBEYE, a component of synaptic ribbons: a protein’s journey through evolution provides insight into synaptic ribbon function. Neuron 28(3):857–872. doi:10.1016/S0896-6273(00)00159-8
Schröder S, Palinski W, Schmid-Schönbein GW (1991) Activated monocytes and granulocytes, capillary nonperfusion, and neovascularization in diabetic retinopathy. Am J Pathol 139(1):81–100
Scuderi S, D’Amico AG, Castorina A, Imbesi R, Carnazza ML, D’Agata V (2013) Ameliorative effect of PACAP and VIP against increased permeability in a model of outer blood retinal barrier dysfunction. Peptides 39:119–124
Shioda S, Ohtaki H, Nakamachi T, Dohi K, Watanabe J, Nakajo S, Arata S, Kitamura S, Okuda H, Takenoya F, Kitamura Y (2006) Pleiotropic functions of PACAP in the CNS: neuroprotection and neurodevelopment. Ann N Y Acad Sci 1070:550–560. doi:10.1196/annals.1317.080
Singer JH, Lassova L, Vardi N, Diamond JS (2004) Coordinated multivesicular release at a mammalian ribbon synapse. Nat Neurosci 7(8):826–833. doi:10.1038/nn1280
Smit AJ, Lutgers HL (2004) The clinical relevance of advanced glycation endproducts (AGE) and recent developments in pharmaceutics to reduce AGE accumulation. Curr Med Chem 11(20):2767–2784. doi:10.2174/0929867043364342
Somogyvari-Vigh A, Reglodi D (2004) Pituitary adenylate cyclase activating polypeptide: a potential neuroprotective peptide. Curr Pharm Des 10(23):2861–2889. doi:10.2174/1381612043383548
Sterling P (1998) Retina. In: Shepherd G (ed) The synaptic organization of the brain, 4th edn. Oxford University Press, Oxford, pp 205–253
Stitt AW, Bhaduri T, McMullen CB, Gardiner TA, Archer DB (2000) Advanced glycation end products induce blood-retinal barrier dysfunction in normoglycemic rats. Mol Cell Biol Res Commun 3(6):380–388
Szabadfi K, Atlasz T, Kiss P, Reglodi D, Szabo A, Kovacs K, Szalontai B, GyJr Setalo, Banki E, Csanaky K, Tamas A, Gabriel R (2012) Protective effects of the neuropeptide PACAP in diabetic retinopathy. Cell Tissue Res 348(1):37–46. doi:10.1007/s00441-012-1349-0
Szabadfi K, Szabo A, Kiss P, Reglodi D, Setalo GJr, Kovacs K, Tamas A, Toth G, Gabriel R (2014a) PACAP promotes neuron survival in early experimental diabetic retinopathy. Neurochem Int 64:84–91. doi:10.1016/j.neuint.2013.11.005
Szabadfi K, Pinter E, Reglodi D, Gabriel R (2014b) Neuropeptides, trophic factors, and other substances providing morphofunctional and metabolic protection in experimental models of diabetic retinopathy. Int Rev Cell Mol Biol 311:1–121. doi:10.1016/B978-0-12-800179-0.00001-5
Szabo A, Danyadi B, Bognar E, Szabadfi K, Fabian E, Kiss P, Mester L, Manavalan S, Atlasz T, Gabriel R, Toth G, Tamas A, Reglodi D, Kovacs K (2012) Effect of PACAP on MAP kinases, Akt and cytokine expressions in rat retinal hypoperfusion. Neurosci Lett 523(2):93–98. doi:10.1016/j.neulet.2012.06.044
Tarleton HP, Lemischka IR (2010) Delayed differentiation in embryonic stem cells and mesodermal progenitors in the absence of CtBP2. Mech Dev 127(1–2):107–119. doi:10.1016/j.mod.2009.10.002
Tsukita S, Furuse M, Itoh M (2001) Multifunctional strands in tight junctions. Nat Rev Mol Cell Biol 2(4):285–293. doi:10.1038/35067088
Tsutsumi M, Claus TH, Liang Y, Li Y, Yang L, Zhu J, Dela Cruz F, Peng X, Chen H, Yung SL, Hamren S, Livingston JN, Pan CQ (2002) A potent and highly selective VPAC2 agonist enhances glucose-induced insulin release and glucose disposal: a potential therapy for type 2 diabetes. Diabetes 51(5):1453–1460. doi:10.2337/diabetes.51.5.1453
VanGuilder HD, Brucklacher RM, Patel K, Ellis RW, Freeman WM, Barber AJ (2008) Diabetes downregulates presynaptic proteins and reduces basal synapsyn I phosphorylation in rat retina. Eur J Neurosci 28(1):1–11. doi:10.1111/j.1460-9568.2008.06322.x
Vaudry D, Falluel-Morel A, Bourgault S, Basille M, Burel D, Wurtz O, Fournier A, Chow BK, Hashimoto H, Galas L, Vaudry H (2009) Pituitary adenylate cyclase-activating polypeptide and its receptors: 20 years after the discovery. Pharmacol Rev 61(3):283–357. doi:10.1124/pr.109.001370
Waschek JA (2002) Multiple actions of pituitary adenylyl cyclase activating peptide in nervous system development and regeneration. Dev Neurosci 24(1):14–23. doi:10.1159/000064942
Wilson M (2003) Bassoon’s part in two presynaptic orchestras. Neuron 37(5):728–730. doi:10.1016/S0896-6273(03)00121-1
Xiang M, Zhou L, Macke JP, Yoshioka T, Hendry SH, Eddy RL, Shows TB, Nathans J (1995) The Brn-3 family of POU-domain factors: primary structure, binding specificity, and expression in subsets of retinal ganglion cells and somatosensory neurons. J Neurosci 15(7):4762–4785
Xu H, Chen M, Forrester JV (2009) Para-inflammation in the aging retina. Prog Retin Eye Res 28(5):348–368. doi:10.1016/j.preteyeres.2009.06.001
Yamagishi S, Ueda S, Matsui T, Nakamura K, Okuda S (2008a) Role of advanced glycation end products (AGEs) and oxidative stress in diabetic retinopathy. Curr Pharm Des 14(10):962–968. doi:10.2174/138161208784139729
Yamagishi S, Nakamura K, Matsui T, Ueda S, Fukami K, Okuda S (2008b) Agents that block advanced glycation end product (AGE)-RAGE (receptor for AGEs)-oxidative stress system: a novel therapeutic strategy for diabetic vascular complications. Expert Opin Investig Drugs 17(7):983–996. doi:10.1517/13543784.17.7.983
Yang Y, Mao D, Chen X, Zhao L, Tian Q, Liu C, Zhou BLS (2012) Decrease in retinal neuronal cells in streptozotocin-induced diabetic mice. Mol Vis 18:1411–1420
Zeng XX, Ng YK, Ling EA (2000) Neuronal and microglial response in the retina of streptozotocin-induced diabetic rats. Vis Neurosci 17(3):463–471. doi:10.1017/S0952523800173122
Zong H, Ward M, Stitt AW (2011) AGEs, RAGE, and diabetic retinopathy. Curr Diab Rep 11(4):244–252. doi:10.1007/s11892-011-0198-7
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This work was supported by the Hungarian Science Research Fund OTKA 100144, 104984, Richter Gedeon Centenary Foundation, MTA Lendulet Program. Hungarian Brain Research Program—Grant No. KTIA_13_NAP-A-III/5, Arimura Foundation, PTE ÁOK Research Grant.
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K. Szabadfi and D. Reglodi contributed equally to the work.
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Szabadfi, K., Reglodi, D., Szabo, A. et al. Pituitary Adenylate Cyclase Activating Polypeptide, A Potential Therapeutic Agent for Diabetic Retinopathy in Rats: Focus on the Vertical Information Processing Pathway. Neurotox Res 29, 432–446 (2016). https://doi.org/10.1007/s12640-015-9593-1
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DOI: https://doi.org/10.1007/s12640-015-9593-1