Attenuation by l-thyroxine of oxidant-induced gut epithelial damage

Document Type: Original Article

Authors

1 Department of Physiology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran

2 Department of Microbiology & virology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran

Abstract

Objective(s): Severe injuries are often associated with tissue hypothyroidism, elevated damaging mediators in circulation, and broken gut epithelial barrier.  However, the relationships between the hypothyroid state and gut epithelial damage are largely unknown.  Therefore, in this study, we investigated the effects of L-thyroxine (T4) on in vitro models of intact and compromised gut epithelium.
Materials and Methods: Gut epithelium equivalent was generated by cultivation of IEC-18 rat intestinal epithelial cells into transwell inserts. Confluent cultures were then compromised by scratching or H2O2 and traumatized rat sera (TUR sera) treatments.  Macromolecules permeation and transepithelial electrical resistance (TEER) were evaluated by conventional methods. Morphology and scratch wound closure were assessed microscopically. Cell viability/proliferation was assessed by MTT assay.
Results: Both H2O2 and TUR sera induced marked yet different types of epithelial disintegration.  While H2O2 significantly increased and decreased probe permeation and TEER, respectively, TUR sera was ineffective.  Cultures treated with normal rat sera (sham sera) exhibited morphology, probe permeation, and TEER comparable to those of control cultures.  Presence of T4 attenuated the H2O2-induced but not TUR sera-induced damages. T4 treatment accelerated, albeit marginally, wound closure but had virtually no effects on cell viability/proliferation.  
Conclusion: These data suggest that different mechanisms are involved in oxidant- and trauma-induced gut epithelial barrier breakdown.  Besides, they show that T4 markedly attenuates oxidant-induced gut epithelial damage.  Accordingly, one may also conclude that tissue hypothyroidism does not contribute to trauma-induced gut barrier breakdown.

Keywords

Main Subjects


1. Ramirez M. Multiple organ dysfunction syndrome. Curr Probl Pediatr Adolesc Health Care 2013;43:273-277.
2. Slutsky AS, Tremblay LN. Multiple system organ failure. Is mechanical ventilation a contributing factor? Am J Respir Crit Care Med 1998;157(6 Pt 1):1721-1725.
3. Fink MP. Intestinal epithelial hyperpermeability: update on the pathogenesis of gut mucosal barrier dysfunction in critical illness. Curr Opin Crit Care 2003; 9:143-151.
4. Marshall JC. Inflammation, coagulopathy, and the pathogenesis of multiple organ dysfunction syndrome. Crit Care Med 2001; 29(7 Suppl):S99-106.
5. Volman TJ, Goris RJ, van der Meer JW, Hendriks T. Tissue- and time-dependent upregulation of cytokine mRNA in a murine model for the multiple organ dysfunction syndrome. Ann Surg 2004;240:142-150.
6. Namas RA, Mi Q, Namas R, Almahmoud K, Zaaqoq AM, Abdul-Malak O, et al. Insights into the role of chemokines, damage-associated molecular patterns, and lymphocyte-derived mediators from computational models of trauma-induced inflammation. Antioxid Redox Signal 2015;23:1370-1387.
7. Deitch EA, Xu D, Kaise VL. Role of the gut in the development of injury- and shock induced SIRS and MODS: the gut-lymph hypothesis, a review. Front Biosci 2006;11:520-528.
8. Varedi M, Greeley GH, Jr., Herndon DN, Englander EW. A thermal injury-induced circulating factor(s) compromises intestinal cell morphology, proliferation, and migration. Am J Physiol 1999;277(1 Pt 1):G175-182.
9. Varedi M, Lee HM, Greeley GH, Jr., Herndon DN, Englander EW. Gene expression in intestinal epithelial cells, IEC-6, is altered by burn injury-induced circulating factors. Shock 2001;16:259-263.
10.    Peeters RP, van der Geyten S, Wouters PJ, Darras VM, van Toor H, Kaptein E, et al. Tissue thyroid hormone levels in critical illness. J Clin Endocrinol Metab 2005;90:6498-6507.
11.    Arem R, Wiener GJ, Kaplan SG, Kim HS, Reichlin S, Kaplan MM. Reduced tissue thyroid hormone levels in fatal illness. Metabolism 1993;42:1102-1108.
12.    Bremner WF, Taylor KM, Baird S, Thomson JE, Thomson JA, Ratcliffe JG, et al. Hypothalamo-pituitary-thyroid axis function during cardiopulmonary bypass. J Thorac Cardiovasc Surg 1978;75:392-399.
13.    Sharma AK, Vegh E, Orencole M, Miller A, Blendea D, Moore S, et al. Association of hypothyroidism with adverse events in patients with heart failure receiving cardiac resynchronization therapy. Am J Cardiol 2015;115:1249-1253.
14.    Economidou F, Douka E, Tzanela M, Nanas S, Kotanidou A. Thyroid function during critical illness. Hormones (Athens) 2011;10:117-124.
15.    Senese R, Cioffi F, de Lange P, Goglia F, Lanni A. Thyroid: biological actions of ‘nonclassical’ thyroid hormones. J Endocrinol 2014;221:R1-12.
16.    Mullur R, Liu YY, Brent GA. Thyroid hormone regulation of metabolism. Physiol Rev 2014;94:355-382.
17.    Shen L. Tight junctions on the move: molecular mechanisms for epithelial barrier regulation. Ann N Y Acad Sci 2012;1258:9-18.
18.    Laforenza U. Water channel proteins in the gastrointestinal tract. Mol Aspects Med 2012;33:642-650.
19.    Suzuki T. Regulation of intestinal epithelial permeability by tight junctions. Cell Mol Life Sci 2013;70:631-659.
20.    Tsukamoto T, Nigam SK. Tight junction proteins form large complexes and associate with the cytoskeleton in an ATP depletion model for reversible junction assembly. J Biol Chem 1997;272:16133-16139.
21.    Cunningham KE, Turner JR. Myosin light chain kinase: pulling the strings of epithelial tight junction function. Ann N Y Acad Sci 2012;1258:34-42.
22.    Turner JR, Rill BK, Carlson SL, Carnes D, Kerner R, Mrsny RJ, et al. Physiological regulation of epithelial tight junctions is associated with myosin light-chain phosphorylation. Am J Physiol 1997;273(4 Pt 1):C1378-1385.
23.    Pajouhi N, Owji M, Naghibalhossaini F, Omrani GH, Varedi M. Modulation by thyroid hormone of myosin light chain phosphorylation and aquaporin 5 protein expression in intact lung. J Physiol Biochem 2015;71:99-106.
24.    Madara JL, Moore R, Carlson S. Alteration of intestinal tight junction structure and permeability by cytoskeletal contraction. Am J Physiol 1987;253(6 Pt 1):C854-861.
25.    Tenore A, Fasano A, Gasparini N, Sandomenico ML, Ferrara A, Di Carlo A, et al. Thyroxine effect on intestinal Cl-/HCO3- exchange in hypo- and hyperthyroid rats. J Endocrinol 1996;151:431-437.
26.    Ashida K, Katsura T, Motohashi H, Saito H, Inui K. Thyroid hormone regulates the activity and expression of the peptide transporter PEPT1 in Caco-2 cells. Am J Physiol Gastrointest Liver Physiol 2002;282:G617-623.
27.    Schmitt R, Klussmann E, Kahl T, Ellison DH, Bachmann S. Renal expression of sodium transporters and aquaporin-2 in hypothyroid rats. Am J Physiol Renal Physiol 2003;284:F1097-1104.
28.    Varedi M, Pajouhi N, Owji M, Naghibalhossaini F, Omrani GHR. Differential modulation of claudin 4 expression and myosin light chain phosphorylation by thyroid function in lung injury. Clin Respir J 2017;11:797-804.
29.    Sirakov M, Plateroti M. The thyroid hormones and their nuclear receptors in the gut: from developmental biology to cancer. Biochim Biophys Acta 2011;1812:938-946.
30.    Sirakov M, Boussouar A, Kress E, Frau C, Lone IN, Nadjar J, et al. The thyroid hormone nuclear receptor TRalpha1 controls the Notch signaling pathway and cell fate in murine intestine. Development 2015;142:2764-2774.
31.    Ma TY, Hollander D, Bhalla D, Nguyen H, Krugliak P. IEC-18, a nontransformed small intestinal cell line for studying epithelial permeability. J Lab Clin Med 1992;120:329-341.
32.    Autor AP, Bonham AC, Thies RL. Toxicity of oxygen radicals in cultured pulmonary endothelial cells. J Toxicol Environ Health 1984;13:387-395.
33.    Zhao M, Tang S, Xin J, Wei Y, Liu D. Reactive oxygen species induce injury of the intestinal epithelium during hyperoxia. Int J Mol Med 2018;41:322-330.
34.    Shoji H, Oguchi S, Shinohara K, Shimizu T, Yamashiro Y. Effects of iron-unsaturated human lactoferrin on hydrogen peroxide-induced oxidative damage in intestinal epithelial cells. Pediatr Res 2007;61:89-92.
35.    Kevil CG, Oshima T, Alexander B, Coe LL, Alexander JS. H(2)O(2)-mediated permeability: role of MAPK and occludin. Am J Physiol Cell Physiol 2000;279:C21-30.
36.    Mao L, Chen J, Peng Q, Zhou A, Wang Z. Effects of different sources and levels of zinc on H2O2-induced apoptosis in IEC-6 cells. Biol Trace Elem Res 2013;155:132-141.
37.    Wiese AG, Pacifici RE, Davies KJ. Transient adaptation of oxidative stress in mammalian cells. Arch Biochem Biophys 1995;318:231-240.
38.    Davies KJ. The broad spectrum of responses to oxidants in proliferating cells: a new paradigm for oxidative stress. IUBMB Life 1999;48:41-47.
39.    Rubin R, Farber JL. Mechanisms of the killing of cultured hepatocytes by hydrogen peroxide. Arch Biochem Biophys 1984;228:450-459.
40.    Frau C, Godart M, Plateroti M. Thyroid hormone regulation of intestinal epithelial stem cell biology. Mol Cell Endocrinol 2017;459:90-97.
41.    Skah S, Uchuya-Castillo J, Sirakov M, Plateroti M. The thyroid hormone nuclear receptors and the Wnt/beta-catenin pathway: An intriguing liaison. Dev Biol 2017;422:71-82.
42.    Sun G, Roediger J, Shi YB. Thyroid hormone regulation of adult intestinal stem cells: Implications on intestinal development and homeostasis. Rev Endocr Metab Disord 2016;17:559-569.
43.    Quaroni A, May RJ. Establishment and characterizaton of intestinal epithelial cell cultures. Methods Cell Biol 1980;21b:403-427.
44.    Kevil CG, Okayama N, Alexander JS. H(2)O(2)-mediated permeability II: importance of tyrosine phosphatase and kinase activity. Am J Physiol Cell Physiol 2001;281:C1940-1947.
45.    Kevil CG, Ohno N, Gute DC, Okayama N, Robinson SA, Chaney E, et al. Role of cadherin internalization in hydrogen peroxide-mediated endothelial permeability. Free Radic Biol Med 1998;24:1015-1022.
46.    Hagiwara M, Mamiya S, Ochiai M, Hidaka H. Thyroid hormones inhibit the Ca2+ calmodulin-induced activation of myosin light chain kinase. Biochem Biophys Res Commun 1988;152:270-276.
47.    Mendoza A, Hollenberg AN. New insights into thyroid hormone action. Pharmacol Ther 2017;173:135-145.