Hostname: page-component-586b7cd67f-dlnhk Total loading time: 0 Render date: 2024-11-25T20:09:59.397Z Has data issue: false hasContentIssue false
  • English
  • Français

Imaging and lipidomics methods for lipid analysis in metabolic and cardiovascular disease

Part of: DOHaD ANZ Conference 2016

Published online by Cambridge University Press:  12 July 2017

K. G. Stevens ,
C. A. Bader ,
A. Sorvina ,
D. A. Brooks ,
S. E. Plush  and
J. L. Morrison
K. G. Stevens
Affiliation:
Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, SA, Australia Mechanisms in Cell Biology and Disease Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, SA, Australia
C. A. Bader
Affiliation:
Mechanisms in Cell Biology and Disease Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, SA, Australia
A. Sorvina
Affiliation:
Mechanisms in Cell Biology and Disease Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, SA, Australia
D. A. Brooks
Affiliation:
Mechanisms in Cell Biology and Disease Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, SA, Australia
S. E. Plush
Affiliation:
Mechanisms in Cell Biology and Disease Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, SA, Australia
J. L. Morrison*
Affiliation:
Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, SA, Australia
*
*Address for correspondence: J. L. Morrison, Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, GPO Box 2471, Adelaide, SA 5001, Australia.(Email [email protected])
Get access Rights & Permissions [Opens in a new window]

Abstract

Cardiometabolic diseases exhibit changes in lipid biology, which is important as lipids have critical roles in membrane architecture, signalling, hormone synthesis, homoeostasis and metabolism. However, Developmental Origins of Health and Disease studies of cardiometabolic disease rarely include analysis of lipids. This short review highlights some examples of lipid pathology and then explores the technology available for analysing lipids, focussing on the need to develop imaging modalities for intracellular lipids. Analytical methods for studying interactions between the complex endocrine and intracellular signalling pathways that regulate lipid metabolism have been critical in expanding our understanding of how cardiometabolic diseases develop in association with obesity and dietary factors. Biochemical methods can be used to generate detailed lipid profiles to establish links between lifestyle factors and metabolic signalling pathways and determine how changes in specific lipid subtypes in plasma and homogenized tissue are associated with disease progression. New imaging modalities enable the specific visualization of intracellular lipid traffic and distribution in situ. These techniques provide a dynamic picture of the interactions between lipid storage, mobilization and signalling, which operate during normal cell function and are altered in many important diseases. The development of methods for imaging intracellular lipids can provide a dynamic real-time picture of how lipids are involved in complex signalling and other cell biology pathways; and how they ultimately regulate metabolic function/homoeostasis during early development. Some imaging modalities have the potential to be adapted for in vivo applications, and may enable the direct visualization of progression of pathogenesis of cardiometabolic disease after poor growth in early life.

Keywords

cardiometabolic diseasesimaginglipidomics
Type
Review
Information
Journal of Developmental Origins of Health and Disease , Volume 8 , Issue 5: Themed Issue: Australian Perspectives: Outcomes from the 2016 ANZ , October 2017 , pp. 566 - 574
Check for updates
Copyright
© Cambridge University Press and the International Society for Developmental Origins of Health and Disease 2017 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Footnotes

†

S. E. Plush and J. L. Morrison contributed equally to this article.

References

1. Unger, RH, Clark, GO, Scherer, PE, Orci, L. Lipid homeostasis, lipotoxicity and the metabolic syndrome. Biochim Biophys Acta. 2010; 1801, 209–214.CrossRefGoogle ScholarPubMed
2. Berg, JM, Tymoczko, JL, Stryer, L. Triacylglycerols are highly concentrated energy stores. In Biochemistry (ed. Georgia Lee Hadler), 5th edn, 2002; pp. 641–642. WH Freeman and Company: New York.Google Scholar
3. Watt, MJ, Hoy, AJ. Lipid metabolism in skeletal muscle: generation of adaptive and maladaptive intracellular signals for cellular function. Am J Physiol Endocrinol Metabol. 2012; 302, E1315–E1328.Google Scholar
4. Ameer, F, Scandiuzzi, L, Hasnain, S, Kalbacher, H, Zaidi, N. De novo lipogenesis in health and disease. Metabolism. 2014; 63, 895–902.Google Scholar
5. Rosen, ED, Spiegelman, BM. Adipocytes as regulators of energy balance and glucose homeostasis. Nature. 2006; 444, 847–853.Google Scholar
6. Ducharme, NA, Bickel, PE. Minireview: lipid droplets in lipogenesis and lipolysis. Endocrinology. 2008; 149, 942–949.CrossRefGoogle Scholar
7. Fu, S, Watkins, SM, Hotamisligil, GS. The role of endoplasmic reticulum in hepatic lipid homeostasis and stress signaling. Cell Metab. 2012; 15, 623–634.Google Scholar
8. Fagone, P, Jackowski, S. Membrane phospholipid synthesis and endoplasmic reticulum function. J Lipid Res. 2009; 50, S311–S316.Google Scholar
9. Jarvie, E, Hauguel-de-Mouzon, S, Nelson, SM, et al. Lipotoxicity in obese pregnancy and its potential role in adverse pregnancy outcome and obesity in the offspring. Clin Sci. 2010; 119, 123–129.Google Scholar
10. Walther, TC, Farese, RV. The life of lipid droplets. Biochim Biophys Acta. 2009; 1791, 459–466.Google Scholar
11. Gustafson, B, Gogg, S, Hedjazifar, S, et al. Inflammation and impaired adipogenesis in hypertrophic obesity in man. Am J Physiol Endocrinol Metabol. 2009; 297, E999–E1003.Google Scholar
12. Barker, DJ. The developmental origins of well-being. Philos Trans R Soc Lond B Biol Sci. 2004; 359, 1359–1366.Google Scholar
13. Barker, DJ, Osmond, C, Golding, J, Kuh, D, Wadsworth, ME. Growth in utero, blood pressure in childhood and adult life, and mortality from cardiovascular disease. BMJ. 1989; 298, 564–567.Google Scholar
14. Barker, DJ, Winter, PD, Osmond, C, Margetts, B, Simmonds, SJ. Weight in infancy and death from ischaemic heart disease. Lancet. 1989; 2, 577–580.Google Scholar
15. Fall, CH, Sachdev, HS, Osmond, C, et al. Adult metabolic syndrome and impaired glucose tolerance are associated with different patterns of BMI gain during infancy: data from the New Delhi Birth Cohort. Diabet Care. 2008; 31, 2349–2356.Google Scholar
16. McMillen, IC, Robinson, JS. Developmental origins of the metabolic syndrome: prediction, plasticity, and programming. Physiol Rev. 2005; 85, 571–633.Google Scholar
17. McGillick, EV, Lock, MC, Orgeig, S, Morrison, JL. Maternal obesity mediated predisposition to respiratory complications at birth and in later life: understanding the implications of the obesogenic intrauterine environment. Paediatr Respir Rev. 2016; 21, 11–18.Google Scholar
18. Australian Institute of Health and Welfare (AIHW). Australia’s mothers and babies 2014-in brief. Perinatal Statistics Series No. 32; Cat No. PER87. 2016.Google Scholar
19. Martin, S, Parton, RG. Lipid droplets: a unified view of a dynamic organelle. Nat Rev Mol Cell Biol. 2006; 7, 373–378.Google Scholar
20. Hall, PF, Almahbobi, G. Roles of microfilaments and intermediate filaments in adrenal steroidogenesis. Microsc Res Tech. 1997; 36, 463–479.Google Scholar
21. Almahbobi, G, Williams, LJ, Han, X-G, Hall, PF. Binding of lipid droplets and mitochondria to intermediate filaments in rat Leydig cells. J Reprod Fertil. 1993; 98, 209–217.Google Scholar
22. Merry, B. Mitochondrial structure in the rat adrenal cortex. J Anat. 1975; 119(Pt 3), 611–618.Google Scholar
23. Herms, A, Bosch, M, Ariotti, N, et al. Cell-to-cell heterogeneity in lipid droplets suggests a mechanism to reduce lipotoxicity. Curr Biol. 2013; 23, 1489–1496.CrossRefGoogle ScholarPubMed
24. Blanchette-Mackie, EJ, Dwyer, NK, Barber, T, et al. Perilipin is located on the surface layer of intracellular lipid droplets in adipocytes. J Lipid Res. 1995; 36, 1211–1226.Google Scholar
25. Bartz, R, Li, W-H, Venables, B, et al. Lipidomics reveals that adiposomes store ether lipids and mediate phospholipid traffic. J Lipid Res. 2007; 48, 837–847.CrossRefGoogle ScholarPubMed
26. Zicha, J, Kuneš, J, Devynck, M-A. Abnormalities of membrane function and lipid metabolism in hypertension: a review. Am J Hypertens. 1999; 12, 315–331.Google Scholar
27. van Meer, G. Cellular lipidomics. EMBO J. 2005; 24, 3159–3165.Google Scholar
28. Borkman, M, Storlien, LH, Pan, DA, et al. The relation between insulin sensitivity and the fatty-acid composition of skeletal-muscle phospholipids. N Engl J Med. 1993; 328, 238–244.Google Scholar
29. Holland, WL, Summers, SA. Sphingolipids, insulin resistance, and metabolic disease: new insights from in vivo manipulation of sphingolipid metabolism. Endocr Rev. 2008; 29, 381–402.Google Scholar
30. Wenk, MR. The emerging field of lipidomics. Nat Rev Drug Discov. 2005; 4, 594–610.Google Scholar
31. Ginsberg, HN. Insulin resistance and cardiovascular disease. J Clin Invest. 2000; 106, 453–458.Google Scholar
32. Kotronen, A, Velagapudi, V, Yetukuri, L, et al. Serum saturated fatty acids containing triacylglycerols are better markers of insulin resistance than total serum triacylglycerol concentrations. Diabetologia. 2009; 52, 684–690.Google Scholar
33. Elle, IC, Olsen, LCB, Pultz, D, Rødkær, SV, Færgeman, NJ. Something worth dyeing for: molecular tools for the dissection of lipid metabolism in Caenorhabditis elegans. FEBS Lett. 2010; 584, 2183–2193.Google Scholar
34. Seppänen-Laakso, T, Laakso, I, Hiltunen, R. Analysis of fatty acids by gas chromatography, and its relevance to research on health and nutrition. Anal Chim Acta. 2002; 465, 39–62.Google Scholar
35. Peterson, BL, Cummings, BS. A review of chromatographic methods for the assessment of phospholipids in biological samples. Biomed Chromatogr. 2006; 20, 227–243.Google Scholar
36. Lemaitre, RN, King, IB, Mozaffarian, D, et al. Plasma phospholipid trans fatty acids, fatal ischemic heart disease, and sudden cardiac death in older adults the cardiovascular health study. Circulation. 2006; 114, 209–215.Google Scholar
37. Rissanen, T, Voutilainen, S, Nyyssönen, K, Lakka, TA, Salonen, JT. Fish oil–derived fatty acids, docosahexaenoic acid and docosapentaenoic acid, and the risk of acute coronary events. Circulation. 2000; 102, 2677–2679.Google Scholar
38. Patel, PS, Sharp, SJ, Jansen, E, et al. Fatty acids measured in plasma and erythrocyte-membrane phospholipids and derived by food-frequency questionnaire and the risk of new-onset type 2 diabetes: a pilot study in the European Prospective Investigation into Cancer and Nutrition (EPIC)–Norfolk cohort. Am J Clin Nutr. 2010; 92, 1214–1222.Google Scholar
39. García-Fontana, B, Morales-Santana, S, Navarro, CD, et al. Metabolomic profile related to cardiovascular disease in patients with type 2 diabetes mellitus: a pilot study. Talanta. 2016; 148, 135–143.Google Scholar
40. Blanksby, SJ, Mitchell, TW. Advances in mass spectrometry for lipidomics. Ann Rev Anal Chem. 2010; 3, 433–465.Google Scholar
41. Brügger, B. Lipidomics: analysis of the lipid composition of cells and subcellular organelles by electrospray ionization mass spectrometry. Ann Rev Biochem. 2014; 83, 79–98.CrossRefGoogle ScholarPubMed
42. Park, JY, Lee, SH, Shin, MJ, Hwang, GS. Alteration in metabolic signature and lipid metabolism in patients with angina pectoris and myocardial infarction. PloS One. 2015; 10, e0135228.Google Scholar
43. Furse, S, Egmond, MR, Killian, JA. Isolation of lipids from biological samples. Mol Membr Biol. 2015; 32, 55–64.Google Scholar
44. Li, M, Zhou, Z, Nie, H, Bai, Y, Liu, H. Recent advances of chromatography and mass spectrometry in lipidomics. Anal Bioanal Chem. 2011; 399, 243–249.Google Scholar
45. Alberici, RM, Simas, RC, Sanvido, GB, et al. Ambient mass spectrometry: bringing MS into the ‘real world’. Anal Bioanal Chem. 2010; 398, 265–294.Google Scholar
46. Annesley, TM. Ion suppression in mass spectrometry. Clin Chem. 2003; 49, 1041–1044.Google Scholar
47. Colas, R, Pruneta-Deloche, V, Guichardant, M, et al. Increased lipid peroxidation in LDL from type-2 diabetic patients. Lipids. 2010; 45, 723–731.Google Scholar
48. Ando, J, Kinoshita, M, Cui, J, et al. Sphingomyelin distribution in lipid rafts of artificial monolayer membranes visualized by Raman microscopy. Proc Natl Acad Sci U S A. 2015; 112, 4558–4563.Google Scholar
49. Daemen, S, van Zandvoort, MAMJ, Parekh, SH, Hesselink, MKC. Microscopy tools for the investigation of intracellular lipid storage and dynamics. Mol Metab. 2016; 5, 153–163.Google Scholar
50. Mehlem, A, Hagberg, CE, Muhl, L, Eriksson, U, Falkevall, A. Imaging of neutral lipids by oil red O for analyzing the metabolic status in health and disease. Nat Protoc. 2013; 8, 1149–1154.Google Scholar
51. Goodpaster, BH, He, J, Watkins, S, Kelley, DE. Skeletal muscle lipid content and insulin resistance: evidence for a paradox in endurance-trained athletes. J Clin Endocrinol Metabol. 2001; 86, 5755–5761.Google Scholar
52. Chiu, H-C, Kovacs, A, Ford, DA, et al. A novel mouse model of lipotoxic cardiomyopathy. J Clin Investig. 2001; 107, 813–822.Google Scholar
53. Fukumoto, S, Fujimoto, T. Deformation of lipid droplets in fixed samples. Histochem Cell Biol. 2002; 118, 423–428.Google Scholar
54. Stadtländer, CT. Scanning electron microscopy and transmission electron microscopy of mollicutes: challenges and opportunities. In Modern Research and Educational Topics in Microscopy (eds. Méndez-Vilas A, and Díaz J), 2007; pp. 122–131. Formatex; Badajoz, Spain.Google Scholar
55. de Jonge, N, Ross, FM. Electron microscopy of specimens in liquid. Nat Nanotechnol. 2011; 6, 695–704.Google Scholar
56. Thiam, AR, Farese, RV Jr, Walther, TC. The biophysics and cell biology of lipid droplets. Nat Rev Mol Cell Biol. 2013; 14, 775–786.Google Scholar
57. Binns, D, Januszewski, T, Chen, Y, et al. An intimate collaboration between peroxisomes and lipid bodies. J Cell Biol. 2006; 173, 719–731.Google Scholar
58. Belazi, D, Sole-Domenech, S, Johansson, B, Schalling, M, Sjovall, P. Chemical analysis of osmium tetroxide staining in adipose tissue using imaging ToF-SIMS. Histochem Cell Biol. 2009; 132, 105–115.Google Scholar
59. Orlova, EV, Sherman, MB, Chiu, W, et al. Three-dimensional structure of low density lipoproteins by electron cryomicroscopy. Proc Natl Acad Sci. 1999; 96, 8420–8425.Google Scholar
60. Kizilyaprak, C, Daraspe, J, Humbel, BM. Focused ion beam scanning electron microscopy in biology. J Microsc. 2014; 254, 109–114.Google Scholar
61. Schertel, A, Snaidero, N, Han, HM, et al. Cryo FIB-SEM: volume imaging of cellular ultrastructure in native frozen specimens. J Struct Biol. 2013; 184, 355–360.Google Scholar
62. Haider, M, Muller, H, Uhlemann, S, et al. Prerequisites for a Cc/Cs-corrected ultrahigh-resolution TEM. Ultramicroscopy. 2008; 108, 167–178.Google Scholar
63. Flannigan, DJ, Zewail, AH. 4D electron microscopy: principles and applications. Acc Chem Res. 2012; 45, 1828–1839.Google Scholar
64. Charan, S, Chien, FC, Singh, N, Kuo, CW, Chen, P. Development of lipid targeting Raman probes for in vivo imaging of Caenorhabditis elegans. Chemistry. 2011; 17, 5165–5170.CrossRefGoogle ScholarPubMed
65. Evans, CL, Xie, XS. Coherent anti-Stokes Raman scattering microscopy: chemical imaging for biology and medicine. Ann Rev Anal Chem. 2008; 1, 883–909.Google Scholar
66. Carter, EA, Tam, KK, Armstrong, RS, Lay, PA. Vibrational spectroscopic mapping and imaging of tissues and cells. Biophys Rev. 2009; 1, 95–103.Google Scholar
67. Enejder, A, Brackmann, C, Axäng, C, Åkeson, M, Pilon, M. CARS microscopy for the monitoring of lipid storage in C. elegans. In Proceedings of Biomedical Optics (BiOS) 2008, International Society for Optics and Photonics, 2008, pp. 686012.Google Scholar
68. Czamara, K, Majzner, K, Pacia, M, et al. Raman spectroscopy of lipids: a review. J Raman Spectrosc. 2015; 46, 4–20.Google Scholar
69. Billecke, N, Bosma, M, Rock, W, et al. Perilipin 5 mediated lipid droplet remodelling revealed by coherent Raman imaging. Integr Biol. 2015; 7, 467–476.Google Scholar
70. Sztalryd, C, Xu, G, Dorward, H, et al. Perilipin A is essential for the translocation of hormone-sensitive lipase during lipolytic activation. J Cell Biol. 2003; 161, 1093–1103.Google Scholar
71. Nan, X, Potma, EO, Xie, XS. Nonperturbative chemical imaging of organelle transport in living cells with coherent anti-Stokes Raman scattering microscopy. Biophys J. 2006; 91, 728–735.Google Scholar
72. Song, YS, Won, YJ, Kim, DY. Time-lapse in situ fluorescence lifetime imaging of lipid droplets in differentiating 3T3-L1 preadipocytes with Nile Red. Curr Appl Phys. 2015; 15, 1634–1640.Google Scholar
73. Amaya, KR, Monroe, EB, Sweedler, JV, Clayton, DF. Lipid imaging in the zebra finch brain with secondary ion mass spectrometry. Int J Mass Spectrom. 2007; 260, 121–127.Google Scholar
74. Colliver, TL, Brummel, CL, Pacholski, ML, et al. Atomic and molecular imaging at the single-cell level with TOF-SIMS. Anal Chem. 1997; 69, 2225–2231.Google Scholar
75. Chen, R, Hui, L, Sturm, RM, Li, L. Three dimensional mapping of neuropeptides and lipids in crustacean brain by mass spectral imaging. J Am Soc Mass Spectrom. 2009; 20, 1068–1077.Google Scholar
76. Chen, Y, Allegood, J, Liu, Y, et al. Imaging MALDI mass spectrometry using an oscillating capillary nebulizer matrix coating system and its application to analysis of lipids in brain from a mouse model of Tay-Sachs/Sandhoff disease. Anal Chem. 2008; 80, 2780–2788.Google Scholar
77. Kner, P, Sedat, JW, Agard, DA, Kam, Z. High-resolution wide-field microscopy with adaptive optics for spherical aberration correction and motionless focusing. J Microsc. 2010; 237, 136–147.Google Scholar
78. Huang, B, Bates, M, Zhuang, X. Super-resolution fluorescence microscopy. Ann Rev Biochem. 2009; 78, 993–1016.Google Scholar
79. Huang, B, Wang, W, Bates, M, Zhuang, X. Three-dimensional super-resolution imaging by stochastic optical reconstruction microscopy. Science. 2008; 319, 810–813.Google Scholar
80. Schmidt, R, Wurm, CA, Jakobs, S, et al. Spherical nanosized focal spot unravels the interior of cells. Nat Methods.. 2008; 5, 539–544.Google Scholar
81. Stehbens, S, Pemble, H, Murrow, L, Wittmann, T. Imaging intracellular protein dynamics by spinning disk confocal microscopy. Methods Enzymol. 2012; 504, 293–313.Google Scholar
82. Li, S, Hu, P, Malmstadt, N. Confocal imaging to quantify passive transport across biomimetic lipid membranes. Anal Chem. 2010; 82, 7766–7771.Google Scholar
83. Santi, PA. Light sheet fluorescence microscopy: a review. J Histochem Cytochem. 2011; 59, 129–138.Google Scholar
84. Girstmair, J, Zakrzewski, A, Lapraz, F, et al. Light-sheet microscopy for everyone? Experience of building an OpenSPIM to study flatworm development. BMC Dev Biol. 2016; 16, 22.Google Scholar
85. Royer, LA, Lemon, WC, Chhetri, RK, et al. Adaptive light-sheet microscopy for long-term, high-resolution imaging in living organisms. Nat Biotechnol. 2016; 34, 1267–1278.Google Scholar
86. Greenspan, P, Mayer, EP, Fowler, SD. Nile red: a selective fluorescent stain for intracellular lipid droplets. J Cell Biol. 1985; 100, 965–973.Google Scholar
87. Singh, R, Kaushik, S, Wang, Y, et al. Autophagy regulates lipid metabolism. Nature. 2009; 458, 1131–1135.Google Scholar
88. Sinha, RA, You, S-H, Zhou, J, et al. Thyroid hormone stimulates hepatic lipid catabolism via activation of autophagy. J Clin Invest. 2012; 122, 2428–2438.Google Scholar
89. Shibata, M, Yoshimura, K, Furuya, N, et al. The MAP1-LC3 conjugation system is involved in lipid droplet formation. Biochem Biophys Res Commun. 2009; 382, 419–423.Google Scholar
90. Koga, H, Kaushik, S, Cuervo, AM. Altered lipid content inhibits autophagic vesicular fusion. FASEB J. 2010; 24, 3052–3065.Google Scholar
91. Hölttä‐Vuori, M, Uronen, RL, Repakova, J, et al. BODIPY‐Cholesterol: a new tool to visualize sterol trafficking in living cells and organisms. Traffic. 2008; 9, 1839–1849.Google Scholar
92. Ishitsuka, R, Sato, SB, Kobayashi, T. Imaging lipid rafts. J Biochem. 2005; 137, 249–254.Google Scholar
93. O’Rourke, EJ, Soukas, AA, Carr, CE, Ruvkun, G. C. elegans major fats are stored in vesicles distinct from lysosome-related organelles. Cell Metab. 2009; 10, 430–435.Google Scholar
94. Bader, C, Carter, E, Safitri, A, et al. Unprecedented staining of polar lipids by a luminescent rhenium complex revealed by FTIR microspectroscopy in adipocytes. Mol Biosyst. 2016; 12, 2064–2068.Google Scholar
95. Bader, CA, Brooks, RD, Ng, YS, et al. Modulation of the organelle specificity in Re(i) tetrazolato complexes leads to labeling of lipid droplets. RSC Adv. 2014; 4, 16345–16351.Google Scholar
96. Bader, CA, Shandala, T, Carter, EA, et al. A molecular probe for the detection of polar lipids in live cells. PloS One. 2016; 11, E0161557.Google Scholar
97. Bader, CA, Sorvina, A, Simpson, PV, et al. Imaging nuclear, endoplasmic reticulum and plasma membrane events in real time. FEBS Lett. 2016; 590, 3051–3060.Google Scholar
98. Lo, K, Choi, A, Law, W. Applications of luminescent inorganic and organometallic transition metal complexes as biomolecular and cellular probes. Dalton Trans. 2012; 41, 6021–6047.Google Scholar
99. Svoboda, K, Yasuda, R. Principles of two-photon excitation microscopy and its applications to neuroscience. Neuron. 2006; 50, 823–839.Google Scholar
100. Hackett, MJ, McQuillan, JA, El-Assaad, F, et al. Chemical alterations to murine brain tissue induced by formalin fixation: implications for biospectroscopic imaging and mapping studies of disease pathogenesis. Analyst. 2011; 136, 2941–2952.Google Scholar