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Shafia S, Khoramirad A, Akhoundzadeh K. Thyroid hormones and stroke, the gap between clinical and experimental studies. Brain Res Bull 2024; 213:110983. [PMID: 38795852 DOI: 10.1016/j.brainresbull.2024.110983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 05/19/2024] [Accepted: 05/21/2024] [Indexed: 05/28/2024]
Abstract
Despite plenty of human studies on changes in thyroid hormones after stroke and some animal studies that assessed the effects of thyroid hormone administration on stroke, conclusive evidence for clinical application is lacking. This review aimed to determine the consistency of the results between clinical and preclinical studies. This article reviewed the PubMed, Embase, web of Knowledge, and Google Scholar databases up to June 2023 using the MeSH terms "stroke, cerebral ischemia, cerebral infarction, brain ischemia, brain infarction, triiodothyronine (T3), tetraiodothyronine (T4), thyroxine (T4), and thyroid hormone". The results of clinical and preclinical studies related to T3 substantially confirm each other. That is, in most human studies lower T3 was associated with poor outcomes, and in experimental studies, T3 administration also had therapeutic effects. However, the results of experimental studies related to T4 could not support those of clinical studies. There seem to be some conflicts between experimental and human studies, especially regarding changes and effects of T4 after stroke. The gap between experimental and clinical studies may lead to non-applicable results, wasting time and money, and unnecessary killing of animals.
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Affiliation(s)
- Sakineh Shafia
- Immunogenetic Research Center, Department of Physiology, Mazandaran University of Medical Sciences, Sari, Iran.
| | - Ashraf Khoramirad
- Department of Nursing, Qom University of Medical Sciences, Qom, Iran.
| | - Kobra Akhoundzadeh
- Department of Physiology, Qom University of Medical Sciences, Qom, Iran.
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Pan G, Zhao G, Li L, Yu L, Liu Y, Yang R, Yang T, Wang Y, Su J, Li Z, Liu F, Yu C. Association of thyroid hormone sensitivity index with stroke in patients with coronary artery disease. J Stroke Cerebrovasc Dis 2024; 33:107482. [PMID: 38061182 DOI: 10.1016/j.jstrokecerebrovasdis.2023.107482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 10/22/2023] [Accepted: 11/08/2023] [Indexed: 01/23/2024] Open
Abstract
BACKGROUND AND AIMS Thyroid hormones (THs) will affect the occurrence and prognosis of stroke, and the research on THs sensitivity index and stroke in patients with coronary heart disease (CHD) is scarce. The goal of this study is to look into the relationship between central and peripheral THs sensitivity index and stroke in patients with CHD. METHODS Between January 1, 2014, and September 30, 2020, 30,160 patients with CHD were enrolled in this study. By computing the thyroid feedback quantile index (TFQI), thyroid stimulating hormone index (TSHI), and thyrotropin thyroxine resistance index (TT4RI), the central sensitivity indexes to THs was assessed, and the ratio of serum free triiodothyronine (FT3) to serum free thyroxine (FT4) was used to assess peripheral THs sensitivity. The relationship between central and peripheral THs sensitivity index and stroke was investigated using logistic regression, especially in different types of stroke, ages, sexes, and blood glucose levels. RESULTS Stroke risk is positive associated with TSHI, TFQI, and PTFQI. In subgroup analysis, the OR values of these relationships are higher in people younger than 65 years old, male, and diagnosed with diabetes. In addition, stroke risk was negatively associated with FT3/FT4, and the OR values of these relationships were lower in people older than 65 years, female, and diagnosed with prediabetes. CONCLUSIONS This study demonstrates that the increase in the central THs sensitivity index and the decrease in the peripheral THs sensitivity index are associated with a higher risk of stroke in CHD patients, and provides new ideas for the assessment of stroke in patients with CHD.
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Affiliation(s)
- Guangwei Pan
- Tianjin University of Traditional Chinese Medicine, 10 Poyanghu Road, West Area, Tuanbo New Town, Jinghai District, Tianjin 301617, China
| | - Guoyuan Zhao
- First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin 300381, China
| | - Lin Li
- Tianjin University of Traditional Chinese Medicine, 10 Poyanghu Road, West Area, Tuanbo New Town, Jinghai District, Tianjin 301617, China
| | - Lu Yu
- Tianjin University of Traditional Chinese Medicine, 10 Poyanghu Road, West Area, Tuanbo New Town, Jinghai District, Tianjin 301617, China
| | - Yijia Liu
- Tianjin University of Traditional Chinese Medicine Second Affiliated Hospital, Tianjin 300250, China
| | - Rongrong Yang
- Tianjin University of Traditional Chinese Medicine, 10 Poyanghu Road, West Area, Tuanbo New Town, Jinghai District, Tianjin 301617, China
| | - Tong Yang
- Tianjin University of Traditional Chinese Medicine, 10 Poyanghu Road, West Area, Tuanbo New Town, Jinghai District, Tianjin 301617, China
| | - Yang Wang
- Tianjin University of Traditional Chinese Medicine, 10 Poyanghu Road, West Area, Tuanbo New Town, Jinghai District, Tianjin 301617, China
| | - Jinyu Su
- Tianjin University of Traditional Chinese Medicine, 10 Poyanghu Road, West Area, Tuanbo New Town, Jinghai District, Tianjin 301617, China
| | - Zhu Li
- Tianjin University of Traditional Chinese Medicine, 10 Poyanghu Road, West Area, Tuanbo New Town, Jinghai District, Tianjin 301617, China
| | - Fengmin Liu
- Tianjin University of Traditional Chinese Medicine, 10 Poyanghu Road, West Area, Tuanbo New Town, Jinghai District, Tianjin 301617, China
| | - Chunquan Yu
- Tianjin University of Traditional Chinese Medicine, 10 Poyanghu Road, West Area, Tuanbo New Town, Jinghai District, Tianjin 301617, China.
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Akhoundzadeh K, Vakili A. Effect of stem cells-based therapy on astrogliosis in stroke subjected-mice. Stem Cell Investig 2020; 7:21. [PMID: 33437841 DOI: 10.21037/sci-2020-031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Accepted: 12/08/2020] [Indexed: 01/18/2023]
Abstract
This study was planned to continue our previous study to assess effect of combination therapy bone marrow stromal cells (BMSCs) with exercise (EX) and triiodothyronine (T3) on stroke-induced astrogliosis in mice. Stroke subjected-mice were divided into five monotherapy groups including sham, control, BMSCs, EX and T3; and three combination therapy groups including BMSCs + EX, BMSCs + T3 and BMSCs + EX + T3. Astrogliosis was assessed in ipsilateral hemisphere at day 7 after MCAO. Combination therapy BMSCs with EX and T3 could significantly decrease stroke-induced astrogliosis. However, monotherapy with BMSCs or EX also improved changes of glial fibrillary acidic protein (GFAP)-positive cells following stroke. Combination therapy BMSCs with EX and T3 didn't have any added effect on astrogliosis compared to monotherapy with BMSCs or EX. With comparing the present findings with the results of neurobehavioral functioning in our earlier study, it seems that decrease of astrogliosis could be helpful for stroke recovery.
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Affiliation(s)
- Kobra Akhoundzadeh
- Faculty of Nursing, Qom University of Medical Sciences, Qom, Iran.,Physiology Research Center, Semnan University of Medical Sciences, Semnan, Iran
| | - Abedin Vakili
- Physiology Research Center, Semnan University of Medical Sciences, Semnan, Iran
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Xu AL, Zheng GY, Ye HY, Chen XD, Jiang Q. Characterization of astrocytes and microglial cells in the hippocampal CA1 region after transient focal cerebral ischemia in rats treated with Ilexonin A. Neural Regen Res 2020; 15:78-85. [PMID: 31535655 PMCID: PMC6862412 DOI: 10.4103/1673-5374.264465] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Ilexonin A is a compound isolated from the root of Ilex pubescens, a traditional Chinese medicine. Ilexonin A has been shown to play a neuroprotective role by regulating the activation of astrocytes and microglia in the peri-infarct area after ischemia. However, the effects of ilexonin A on astrocytes and microglia in the infarct-free region of the hippocampal CA1 region remain unclear. Focal cerebral ischemia models were established by 2-hour occlusion of the middle cerebral artery in rats. Ilexonin A (20, 40 or 80 mg/kg) was administered immediately after ischemia/reperfusion. The astrocyte marker glial fibrillary acidic protein, microglia marker Iba-1, neural stem cell marker nestin and inflammation markers were detected by immunohistochemistry and western blot assay. Expression levels of tumor necrosis factor-α and interleukin 1β were determined by enzyme linked immunosorbent assay in the hippocampal CA1 tissue. Astrocytes were activated immediately in progressively increasing numbers from 1, 3, to 7 days post-ischemia/reperfusion. The number of activated astrocytes further increased in the hippocampal CA1 region after treatment with ilexonin A. Microglial cells remained quiescent after ischemia/reperfusion, but became activated after treatment with ilexonin A. Ilexonin A enhanced nestin expression and reduced the expression of tumor necrosis factor-α and interleukin 1β in the hippocampus post-ischemia/reperfusion. The results of the present study suggest that ilexonin A has a neuroprotective effect in the hippocampus after ischemia/reperfusion, probably through regulating astrocytes and microglia activation, promoting neuronal stem cell proliferation and reducing the levels of pro-inflammatory factors. This study was approved by the Animal Ethics Committee of the Fujian Medical University Union Hospital, China.
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Affiliation(s)
- Ai-Ling Xu
- Department of Traditional Chinese Medicine, Fujian Medical University Union Hospital; Department of Neonatology, People's Hospital Affiliated to Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian Province, China
| | - Guan-Yi Zheng
- Department of Traditional Chinese Medicine, Fujian Medical University Union Hospital, Fuzhou, Fujian Province, China
| | - Hui-Ying Ye
- Department of Traditional Chinese Medicine, Fujian Medical University Union Hospital, Fuzhou; Department of Neurology, People's Hospital of Nanping, Nanping, Fujian Province, China
| | - Xiao-Dong Chen
- Burns Institute of Fujian Medical University Union Hospital, Fuzhou, Fujian Province, China
| | - Qiong Jiang
- Burns Institute of Fujian Medical University Union Hospital, Fuzhou, Fujian Province, China
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Talhada D, Santos CRA, Gonçalves I, Ruscher K. Thyroid Hormones in the Brain and Their Impact in Recovery Mechanisms After Stroke. Front Neurol 2019; 10:1103. [PMID: 31681160 PMCID: PMC6814074 DOI: 10.3389/fneur.2019.01103] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 10/02/2019] [Indexed: 12/23/2022] Open
Abstract
Thyroid hormones are of fundamental importance for brain development and essential factors to warrant brain functions throughout life. Their actions are mediated by binding to specific intracellular and membranous receptors regulating genomic and non-genomic mechanisms in neurons and populations of glial cells, respectively. Among others, mechanisms include the regulation of neuronal plasticity processes, stimulation of angiogenesis and neurogenesis as well modulating the dynamics of cytoskeletal elements and intracellular transport processes. These mechanisms overlap with those that have been identified to enhance recovery of lost neurological functions during the first weeks and months after ischemic stroke. Stimulation of thyroid hormone signaling in the postischemic brain might be a promising therapeutic strategy to foster endogenous mechanisms of repair. Several studies have pointed to a significant association between thyroid hormones and outcome after stroke. With this review, we will provide an overview on functions of thyroid hormones in the healthy brain and summarize their mechanisms of action in the developing and adult brain. Also, we compile the major thyroid-modulated molecular pathways in the pathophysiology of ischemic stroke that can enhance recovery, highlighting thyroid hormones as a potential target for therapeutic intervention.
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Affiliation(s)
- Daniela Talhada
- Laboratory for Experimental Brain Research, Division of Neurosurgery, Department of Clinical Sciences, Lund University, Lund, Sweden
- CICS-UBI-Health Sciences Research Centre, Faculdade de Ciências da Saúde, Universidade da Beira Interior, Covilha, Portugal
- LUBIN Lab-Lunds Laboratorium för Neurokirurgisk Hjärnskadeforskning, Division of Neurosurgery, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Cecília Reis Alves Santos
- CICS-UBI-Health Sciences Research Centre, Faculdade de Ciências da Saúde, Universidade da Beira Interior, Covilha, Portugal
| | - Isabel Gonçalves
- CICS-UBI-Health Sciences Research Centre, Faculdade de Ciências da Saúde, Universidade da Beira Interior, Covilha, Portugal
| | - Karsten Ruscher
- Laboratory for Experimental Brain Research, Division of Neurosurgery, Department of Clinical Sciences, Lund University, Lund, Sweden
- LUBIN Lab-Lunds Laboratorium för Neurokirurgisk Hjärnskadeforskning, Division of Neurosurgery, Department of Clinical Sciences, Lund University, Lund, Sweden
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Effects of Dendropanax morbifera Léveille extract on hypothyroidism-induced oxidative stress in the rat hippocampus. Food Sci Biotechnol 2016; 25:1761-1766. [PMID: 30263472 DOI: 10.1007/s10068-016-0268-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 08/19/2016] [Accepted: 08/26/2016] [Indexed: 01/20/2023] Open
Abstract
In this experiment, we verified the effects of Dendropanax morbifera Léveille stem extract (DMS) on hypothyroidism-induced oxidative stress in the hippocampus of rats. Hypothyroidism was induced in rats by treating them with 0.03% 2-mercapto-1-methyl-imidazole dissolved in drinking water for 5 weeks. DMS (100 mg/kg) was also orally administered to the rats during the same period and the animals were sacrificed at 12 weeks of age. DMS administration tended to ameliorate these hypothyroidism-induced changes in serum triiodothyronine (T3), thyroxine (T4), and thyroid-stimulating hormone levels. DMS administration significantly reduced the hypothyroidism-induced increases in reactive oxygen species production as well as in lipid peroxidation in the hippocampus. In addition, DMS administration increased hippocampal Cu, Zn-superoxide dismutase (SOD1), catalase (CAT), and glutathione peroxidase (GPx) levels. These results suggest that DMS potentially ameliorates hypothyroidism-induced neuroendocrine phenotypes and oxidative stress in the hippocampus via the induction of antioxidant enzymes.
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XU AILING, ZHENG GUANYI, WANG ZHIJIAN, CHEN XIAODONG, JIANG QIONG. Neuroprotective effects of Ilexonin A following transient focal cerebral ischemia in rats. Mol Med Rep 2016; 13:2957-66. [PMID: 26936330 PMCID: PMC4805093 DOI: 10.3892/mmr.2016.4921] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Accepted: 12/30/2015] [Indexed: 11/06/2022] Open
Abstract
Ilexonin A is a compound isolated from the root of a plant commonly used in traditional Chinese medicine. The aim of the present study was to investigate the possible protective mechanism of Ilexonin A in rats subjected to occlusion of the middle cerebral artery (MCAO). Transient focal cerebral ischemia was induced by 2 h of MCAO, followed by reperfusion. Ilexonin A at doses of 20, 40 and 80 mg/kg were administered via intraperitoneal injection immediately following ischemia/reperfusion. The expression levels of glial fibrillary acidic protein (GFAP), ionized calcium‑binding adapter molecule‑1 (Iba‑1), vascular endothelial growth factor (VEGF), fetal liver kinase‑1 (Flk‑1) and Nestin were examined using immunostaining and Western blot analysis of the peri‑infarct region following ischemia/reperfusion. Ilexonin A significantly decreased the infarct volume and improved neurological deficits in a dose‑dependent manner. The expression levels of VEGF, Flk‑1 and Nestin were significantly increased in the rats treated with Ilexonin A, compared with the rats administered with saline. Following treatment with Ilexonin A, a higher number of GFAP‑positive astrocytes were found in the Ilexonin A‑treated rats at 1, 3 and 7 days, compared with the rats exposed to ischemia only, however, there were fewer astrocytes at 14 days, compared with the ischemia group. Ilexonin A significantly decreased the protein expression of Iba‑1. The results of the present study suggested that the protective effects of Ilexonin A were associated with revascularization, neuronal regeneration, and the regulation of astrocyte and microglia cell activation.
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Affiliation(s)
- AI-LING XU
- Department of Traditional Chinese Medicine, The Affiliated Union Hospital of Fujian Medical University, Fuzhou, Fujian 350001, P.R. China
- Neonatal Department, The People's Hospital Affiliated to Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350004, P.R. China
| | - GUAN-YI ZHENG
- Department of Traditional Chinese Medicine, The Affiliated Union Hospital of Fujian Medical University, Fuzhou, Fujian 350001, P.R. China
| | - ZHI-JIAN WANG
- Department of Traditional Chinese Medicine, The Affiliated Union Hospital of Fujian Medical University, Fuzhou, Fujian 350001, P.R. China
- Department of Neurology, Fuzhou Neuro-Psychiatric Hospital, Fuzhou, Fujian 350000, P.R. China
| | - XIAO-DONG CHEN
- Burns Institute of the Affliated Union Hospital of Fujian Medical University, Fuzhou, Fujian 350001, P.R. China
| | - QIONG JIANG
- Burns Institute of the Affliated Union Hospital of Fujian Medical University, Fuzhou, Fujian 350001, P.R. China
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Nam SM, Kim YN, Yoo DY, Yi SS, Choi JH, Hwang IK, Seong JK, Yoon YS. Hypothyroidism affects astrocyte and microglial morphology in type 2 diabetes. Neural Regen Res 2014; 8:2458-67. [PMID: 25206556 PMCID: PMC4146114 DOI: 10.3969/j.issn.1673-5374.2013.26.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Accepted: 07/25/2013] [Indexed: 12/03/2022] Open
Abstract
In the present study, we investigated the effects of hypothyroidism on the morphology of astrocytes and microglia in the hippocampus of Zucker diabetic fatty rats and Zucker lean control rats. To induce hypothyroidism, Zucker lean control and Zucker diabetic fatty rats at 7 weeks of age orally received the vehicle or methimazole, an anti-thyroid drug, treatment for 5 weeks and were sacrificed at 12 weeks of age in all groups for blood chemistry and immunohistochemical staining. In the methimazole-treated Zucker lean control and Zucker diabetic fatty rats, the serum circulating thyronine (T3) and thyroxine (T4) levels were significantly decreased compared to levels observed in the vehicle-treated Zucker lean control or Zucker diabetic fatty rats. This reduction was more prominent in the methimazole-treated Zucker diabetic fatty group. Glial fibrillary acidic protein immunoreactive astrocytes and ionized calcium-binding adapter molecule 1 (Iba-1)-immunoreactive microglia in the Zucker lean control and Zucker diabetic fatty group were diffusely detected in the hippocampal CA1 region and dentate gyrus. There were no significant differences in the glial fibrillary acidic protein and Iba-1 immunoreactivity in the CA1 region and dentate gyrus between Zucker lean control and Zucker diabetic fatty groups. However, in the methimazole-treated Zucker lean control and Zucker diabetic fatty groups, the processes of glial fibrillary acidic protein tive astrocytes and Iba-1 immunoreactive microglia, were significantly decreased in both the CA1 region and dentate gyrus compared to that in the vehicle-treated Zucker lean control and Zucker diabetic fatty groups. These results suggest that diabetes has no effect on the morphology of astrocytes and microglia and that hypothyroidism during the onset of diabetes prominently reduces the processes of astrocytes and microglia.
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Affiliation(s)
- Sung Min Nam
- Department of Anatomy and Cell Biology, College of Veterinary Medicine, Research Institute for Veterinary Science, Seoul National University, Seoul 151-742, South Korea
| | - Yo Na Kim
- Department of Anatomy and Cell Biology, College of Veterinary Medicine, Research Institute for Veterinary Science, Seoul National University, Seoul 151-742, South Korea
| | - Dae Young Yoo
- Department of Anatomy and Cell Biology, College of Veterinary Medicine, Research Institute for Veterinary Science, Seoul National University, Seoul 151-742, South Korea
| | - Sun Shin Yi
- Department of Biomedical Laboratory Science, College of Biomedical Sciences, Soonchunhyang University, Asan 336-745, South Korea
| | - Jung Hoon Choi
- Department of Anatomy, College of Veterinary Medicine, Kangwon National University, Chuncheon 200-701, South Korea
| | - In Koo Hwang
- Department of Anatomy and Cell Biology, College of Veterinary Medicine, Research Institute for Veterinary Science, Seoul National University, Seoul 151-742, South Korea
| | - Je Kyung Seong
- Department of Anatomy and Cell Biology, College of Veterinary Medicine, Research Institute for Veterinary Science, Seoul National University, Seoul 151-742, South Korea
| | - Yeo Sung Yoon
- Department of Anatomy and Cell Biology, College of Veterinary Medicine, Research Institute for Veterinary Science, Seoul National University, Seoul 151-742, South Korea
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Lourbopoulos A, Mourouzis I, Karapanayiotides T, Nousiopoulou E, Chatzigeorgiou S, Mavridis T, Kokkinakis I, Touloumi O, Irinopoulou T, Chouliaras K, Pantos C, Karacostas D, Grigoriadis N. Changes in thyroid hormone receptors after permanent cerebral ischemia in male rats. J Mol Neurosci 2014; 54:78-91. [PMID: 24577884 DOI: 10.1007/s12031-014-0253-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Accepted: 02/04/2014] [Indexed: 11/25/2022]
Abstract
Thyroid hormones (TH) and receptors (TRs) may play an important role in the pathophysiology of acute cerebral ischemia. In the present study, we sought to determine whether serum triodothyronine (T3)/thyroxine (T4) and brain TRs (TRα1, TRβ1) might change after experimental stroke. Male adult Wistar rats were subjected to permanent middle cerebral artery occlusion (group P) and compared to sham-operated controls (group S). Animals were followed clinically for 14 days until brain collection for Western blot (WB) or neuropathological analysis of TRs in three different brain areas (infarcted tissue, E1; noninfarcted ipsilateral hemisphere, E2; and contralateral hemisphere, E3). Analysis of serum TH levels showed a reduction of T4 in group P (p = 0.002) at days 2 to 14, while half of the animals also displayed "low T3" values (p = 0.012) on day 14. This T4 reduction was inversely correlated to the clinical severity of stroke and the concomitant body weight loss (p < 0.005). WB analysis of TRα1 and TRβ1 protein expression showed heterogenic responses at day 14: total and nuclear TRα1 were similar between the two groups, while total TRβ1 decreased 7.5-fold within E1 (p ≤ 0.001) with a concomitant 1.8-fold increase of nuclear TRβ1 in E2 area (p = 0.03); TRβ1 expression did not differ in E3. Neuropathological analysis revealed that activated macrophages/microglia exclusively expressed nuclear TRα1 within the infarct core. Astrocytes mildly expressed nuclear TRα1 in and around the infarct, along with a prominent TRβ nuclear signal restricted in the astrocytic scar. Neurons around the infarct expressed mainly TRα1 and, to a milder degree, TRβ. Surprisingly enough, we detected for the first time a TRβ expression in the paranodal region of Ranvier nodes, of unknown significance so far. Our data support that cerebral ischemia induces a low TH response, associated with significant and heterogenic changes in brain TR expression. These findings could imply an important role of TH signaling in cerebral ischemia.
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Affiliation(s)
- Athanasios Lourbopoulos
- B' Department of Neurology, Laboratory of Experimental Neurology and Neuroimmunology, AHEPA University Hospital, Stilponos Kiriakides str. 1, 54636, Thessaloniki, Macedonia, Greece
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Hypothyroid states mitigate the diabetes-induced reduction of calbindin D-28k, calretinin, and parvalbumin immunoreactivity in type 2 diabetic rats. Neurochem Res 2011; 37:253-60. [PMID: 22037839 DOI: 10.1007/s11064-011-0602-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Revised: 08/29/2011] [Accepted: 09/09/2011] [Indexed: 10/15/2022]
Abstract
In this study, we investigated the differences in calbindin D-28k (CB), calretinin, (CR) and parvalbumin (PV) immunoreactivity in the hippocampus of Zucker diabetic fatty (ZDF) rats and Zucker lean control (ZLC) rats. In addition, we observed the effects of hypothyroidism on the levels of immunoreactivity of these proteins in ZDF rats. For this study, 7-week-old ZDF rats were used, and methimazole treatment was continued for 5 weeks to induce hypothyroidism. The animals were sacrificed at 12 weeks of age. ZDF rats showed increased blood glucose levels compared to those in ZLC rats. Methimazole intervention significantly reduced total and free T3 levels, and it ameliorated the increase of blood glucose levels in ZDF rats. In ZLC rats, CB, CR, and PV immunoreactivity was detected in regions of the hippocampus proper. In vehicle-treated ZDF rats, CB, CR, and PV immunoreactivity was significantly decreased in the hippocampus. However, in the methimazole-treated rats, CB, CR, and PV immunoreactivity was significantly increased compared to that in the vehicle-treated rats. These results suggest that hypothyroidism ameliorated the diabetes-induced reduction of CB, CR, and PV immunoreactivity in the hippocampus.
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Lin HY, Davis FB, Luidens MK, Mousa SA, Cao JH, Zhou M, Davis PJ. Molecular basis for certain neuroprotective effects of thyroid hormone. Front Mol Neurosci 2011; 4:29. [PMID: 22016721 PMCID: PMC3193027 DOI: 10.3389/fnmol.2011.00029] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Accepted: 09/19/2011] [Indexed: 01/26/2023] Open
Abstract
The pathophysiology of brain damage that is common to ischemia-reperfusion injury and brain trauma include disodered neuronal and glial cell energetics, intracellular acidosis, calcium toxicity, extracellular excitotoxic glutamate accumulation, and dysfunction of the cytoskeleton and endoplasmic reticulum. The principal thyroid hormones, 3,5,3'-triiodo-l-thyronine (T(3)) and l-thyroxine (T(4)), have non-genomic and genomic actions that are relevant to repair of certain features of the pathophysiology of brain damage. The hormone can non-genomically repair intracellular H(+) accumulation by stimulation of the Na(+)/H(+) exchanger and can support desirably low [Ca(2+)](i.c.) by activation of plasma membrane Ca(2+)-ATPase. Thyroid hormone non-genomically stimulates astrocyte glutamate uptake, an action that protects both glial cells and neurons. The hormone supports the integrity of the microfilament cytoskeleton by its effect on actin. Several proteins linked to thyroid hormone action are also neuroprotective. For example, the hormone stimulates expression of the seladin-1 gene whose gene product is anti-apoptotic and is potentially protective in the setting of neurodegeneration. Transthyretin (TTR) is a serum transport protein for T(4) that is important to blood-brain barrier transfer of the hormone and TTR also has been found to be neuroprotective in the setting of ischemia. Finally, the interesting thyronamine derivatives of T(4) have been shown to protect against ischemic brain damage through their ability to induce hypothermia in the intact organism. Thus, thyroid hormone or hormone derivatives have experimental promise as neuroprotective agents.
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