1
|
Shushanyan RA, Avtandilyan NV, Grigoryan AV, Karapetyan AF. The role of oxidative stress and neuroinflammatory mediators in the pathogenesis of high-altitude cerebral edema in rats. Respir Physiol Neurobiol 2024; 327:104286. [PMID: 38825093 DOI: 10.1016/j.resp.2024.104286] [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: 04/09/2024] [Revised: 05/29/2024] [Accepted: 05/30/2024] [Indexed: 06/04/2024]
Abstract
High-altitude environments present extreme conditions characterized by low barometric pressure and oxygen deficiency, which can disrupt brain functioning and cause edema formation. The objective of the present study is to investigate several biomolecule expressions and their role in the development of High Altitude Cerebral Edema in a rat model. Specifically, the study focuses on analyzing the changes in total arginase, nitric oxide, and lipid peroxidation (MDA) levels in the brain following acute hypobaric hypoxic exposure (7620 m, SO2=8.1 %, for 24 h) along with the histopathological assessment. The histological examination revealed increased TNF-α activity, and an elevated number of mast cells in the brain, mainly in the hippocampus and cerebral cortex. The research findings demonstrated that acute hypobaric hypoxic causes increased levels of apoptotic cells, shrinkage, and swelling of neurons, accompanied by the formation of protein aggregation in the brain parenchyma. Additionally, the level of nitric oxide and MDA was found to have increased (p<0.0001), however, the level of arginase decreased indicating active lipid peroxidation and redox imbalance in the brain. This study provides insights into the pathogenesis of HACE by evaluating some biomolecules that play a pivotal role in the inflammatory response and the redox landscape in the brain. The findings could have significant implications for understanding the neuronal dysfunction and the pathological mechanisms underlying HACE development.
Collapse
Affiliation(s)
| | - Nikolay V Avtandilyan
- Department of Biochemistry, Microbiology and Biotechnology, Yerevan State University, Yerevan, Armenia
| | - Anna V Grigoryan
- Department of Human and Animal Physiology, Yerevan State University, Armenia
| | - Anna F Karapetyan
- Department of Human and Animal Physiology, Yerevan State University, Armenia
| |
Collapse
|
2
|
Wang X, Wu Z, Zhang Y, Lian B, Ma L, Zhao J. Autophagy induced by hypoxia in pulpitis is mediated by HIF-1α/BNIP3. Arch Oral Biol 2024; 159:105881. [PMID: 38199116 DOI: 10.1016/j.archoralbio.2024.105881] [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: 11/11/2023] [Revised: 01/01/2024] [Accepted: 01/02/2024] [Indexed: 01/12/2024]
Abstract
OBJECTIVE Hypoxia-inducible factor-1α (HIF-1α) and its downstream factor, 19 kDa BCL-2 interacting protein 3 (BNIP3), promote cellular autophagy under hypoxic conditions. However, their roles in pulpitis are unclear. Therefore, the changes in inflammatory response and autophagy levels caused by hypoxia during pulpitis were evaluated. Additionally, the regulatory mechanism of HIF-1α/BNIP3 in cellular autophagy in pulpitis was explored. DESIGN Pulp from dental pulp tissues of healthy individuals and patients with pulpitis (n = 10) were exposed and combined with a low oxygen simulation chamber to construct pulpitis (n = 6), hypoxia (n = 6), and hypoxia+pulpitis (n = 6) rat models. Hematoxylin and eosin and immunohistochemical staining were used to detect the localization and expression levels of HIF-1α, BNIP3, and autophagy marker protein, LC3B. Transmission electron microscopy was used to confirm autophagosome formation. An in vitro hypoxic model of human dental pulp cells was established, and HIF-1α chemical inhibitor 3-(5'-hydroxymethyl-2'-furyl)- 1-benzylindazole (YC-1) was administered. Immunofluorescence and western blotting were used to detect the localization and protein levels of HIF-1α, BNIP3, and LC3B. RESULTS Autophagy is significantly increased and HIF-1α and BNIP3 are elevated in inflamed dental pulp tissue. Both pulp exposure and hypoxia intervention cause inflammatory reactions in rat dental pulp tissue, accompanied by the autophagy activation. Hypoxia significantly enhances HIF-1α/BNIP3 and autophagy activation. BNIP3 downregulates and autophagy reduces after treatment with YC-1. CONCLUSIONS In pulpitis, activation of the HIF-1α/BNIP3 signaling pathway driven by hypoxia leads to increased autophagy. This provides a new molecular explanation for autophagy activation in apical periodontitis and new insights into the pathogenesis of the disease.
Collapse
Affiliation(s)
- Xiaohe Wang
- Department of Cariology and Endodontics, The First Affiliated Hospital of Xinjiang Medical University (The Affiliated Stomatology Hospital of Xinjiang Medical University), No. 137 South Liyushan Road, Urumqi 830054, People's Republic of China; Xinjiang Uygur Autonomous Region Clinical Research Center for Oral Diseases, No.137 South Liyushan Road, Urumqi 830054, People's Republic of China
| | - Zeyu Wu
- Department of Cariology and Endodontics, The First Affiliated Hospital of Xinjiang Medical University (The Affiliated Stomatology Hospital of Xinjiang Medical University), No. 137 South Liyushan Road, Urumqi 830054, People's Republic of China; Xinjiang Uygur Autonomous Region Clinical Research Center for Oral Diseases, No.137 South Liyushan Road, Urumqi 830054, People's Republic of China; Stomatology Disease Institute of Xinjiang Uyghur Autonomous Region, No.137 South Liyushan Road, Urumqi 830054, People's Republic of China
| | - Yangyang Zhang
- Department of Cariology and Endodontics, The First Affiliated Hospital of Xinjiang Medical University (The Affiliated Stomatology Hospital of Xinjiang Medical University), No. 137 South Liyushan Road, Urumqi 830054, People's Republic of China; Xinjiang Uygur Autonomous Region Clinical Research Center for Oral Diseases, No.137 South Liyushan Road, Urumqi 830054, People's Republic of China
| | - Bingjie Lian
- Department of Cariology and Endodontics, The First Affiliated Hospital of Xinjiang Medical University (The Affiliated Stomatology Hospital of Xinjiang Medical University), No. 137 South Liyushan Road, Urumqi 830054, People's Republic of China; Xinjiang Uygur Autonomous Region Clinical Research Center for Oral Diseases, No.137 South Liyushan Road, Urumqi 830054, People's Republic of China; Stomatology Disease Institute of Xinjiang Uyghur Autonomous Region, No.137 South Liyushan Road, Urumqi 830054, People's Republic of China
| | - Li Ma
- Department of Cariology and Endodontics, The First Affiliated Hospital of Xinjiang Medical University (The Affiliated Stomatology Hospital of Xinjiang Medical University), No. 137 South Liyushan Road, Urumqi 830054, People's Republic of China; Xinjiang Uygur Autonomous Region Clinical Research Center for Oral Diseases, No.137 South Liyushan Road, Urumqi 830054, People's Republic of China
| | - Jin Zhao
- Department of Cariology and Endodontics, The First Affiliated Hospital of Xinjiang Medical University (The Affiliated Stomatology Hospital of Xinjiang Medical University), No. 137 South Liyushan Road, Urumqi 830054, People's Republic of China; Xinjiang Uygur Autonomous Region Clinical Research Center for Oral Diseases, No.137 South Liyushan Road, Urumqi 830054, People's Republic of China; Stomatology Disease Institute of Xinjiang Uyghur Autonomous Region, No.137 South Liyushan Road, Urumqi 830054, People's Republic of China.
| |
Collapse
|
3
|
Shushanyan R, Grigoryan A, Abgaryan T, Karapetyan A. Histological and cytochemical analysis of the brain under conditions of hypobaric hypoxia-induced oxygen deficiency in albino rats. Acta Histochem 2023; 125:152114. [PMID: 37980852 DOI: 10.1016/j.acthis.2023.152114] [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: 06/25/2023] [Revised: 11/01/2023] [Accepted: 11/03/2023] [Indexed: 11/21/2023]
Abstract
High altitude sickness is a life-threatening disease that occurs among acclimatized individuals working or living at a high altitude accompanied by hypobaric hypoxia exposure. The prolonged influence of hypobaric hypoxia on the brain may trigger neuronal damage and cell death due to an oxygen deficiency. The purpose of the current study was to investigate the histomorphological changes in the hippocampus, cerebral cortex, cerebellar cortex, and striatum of the rat's brain following chronic hypobaric hypoxia. Fourteen albino rats were used for this investigation. The animals were exposed to chronic hypobaric hypoxia in the special decompression chamber at an altitude of 7000 m for 7 days. The histological analysis was conducted via toluidine staining and silver impregnation. DNA damage and cell apoptosis were assessed via Feulgen staining. The histochemical assessment revealed increased dark neurons in the hippocampus with cell swelling. Silver impregnation showed increased argyrophilic neurons in the cerebellar cortex, striatum, CA1 subfield of the hippocampus, and cerebral cortex. The cytochemical analysis determined the increased apoptotic cells with hyperchromatic condensation and pyknosis in the hippocampus subfields and cerebral cortex. In addition, it has been observed that hypoxia has resulted in small hemorrhages and perivascular edema within the cerebellar and cerebral cortex. The results indicate brain injury observed in the various parts of the brain towards hypobaric hypoxia, however, the hippocampus showed greater vulnerability against hypoxic exposure in comparison to the striatum, cerebellum, and cerebral cortex. These changes support our insights regarding brain intolerance under conditions of hypoxia-induced oxygen deficiency and its histomorphological manifestations.
Collapse
Affiliation(s)
- Ruzanna Shushanyan
- Department of Human and Animal Physiology, Yerevan State University, Yerevan, Armenia.
| | - Anna Grigoryan
- Department of Human and Animal Physiology, Yerevan State University, Yerevan, Armenia.
| | - Tamara Abgaryan
- Department of Human and Animal Physiology, Yerevan State University, Yerevan, Armenia.
| | - Anna Karapetyan
- Department of Human and Animal Physiology, Yerevan State University, Yerevan, Armenia.
| |
Collapse
|
4
|
Li Y, Li C, Luo T, Yue T, Xiao W, Yang L, Zhang Z, Han F, Long P, Hu Y. Progress in the Treatment of High Altitude Cerebral Edema: Targeting REDOX Homeostasis. J Inflamm Res 2023; 16:2645-2660. [PMID: 37383357 PMCID: PMC10296571 DOI: 10.2147/jir.s415695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 06/15/2023] [Indexed: 06/30/2023] Open
Abstract
With the increasing of altitude activities from low-altitude people, the study of high altitude cerebral edema (HACE) has been revived. HACE is a severe acute mountain sickness associated with exposure to hypobaric hypoxia at high altitude, often characterized by disturbance of consciousness and ataxia. As for the pathogenesis of HACE, previous studies suggested that it might be related to the disorder of cerebral blood flow, the destruction of blood-brain barrier and the injury of brain parenchyma cells caused by inflammatory factors. In recent years, studies have confirmed that the imbalance of REDOX homeostasis is also involved in the pathogenesis of HACE, which mainly leads to abnormal activation of microglia and destruction of tight junction of vascular endothelial cells through the excessive production of mitochondrial-related reactive oxygen species. Therefore, this review summarizes the role of REDOX homeostasis and the potential of the treatment of REDOX homeostasis in HACE, which is of great significance to expand the understanding of the pathogenesis of HACE. Moreover, it will also be helpful to further study the possible therapy of HACE related to the key link of REDOX homeostasis.
Collapse
Affiliation(s)
- Yubo Li
- School of Clinical Medicine, Chengdu University of TCM, Chengdu, People’s Republic of China
- Basic Medical Laboratory, The General Hospital of Western Theater Command, Chengdu, People’s Republic of China
| | - Chengming Li
- School of Clinical Medicine, Chengdu University of TCM, Chengdu, People’s Republic of China
- Basic Medical Laboratory, The General Hospital of Western Theater Command, Chengdu, People’s Republic of China
| | - Tao Luo
- Department of Ophthalmology, The General Hospital of Western Theater Command, Chengdu, People’s Republic of China
| | - Tian Yue
- School of Life Science and Engineering, Southwest Jiaotong University, Chengdu, People’s Republic of China
| | - Wenjing Xiao
- Department of Pharmacy, The General Hospital of Western Theater Command, Chengdu, People’s Republic of China
| | - Ling Yang
- School of Clinical Medicine, Chengdu University of TCM, Chengdu, People’s Republic of China
- Basic Medical Laboratory, The General Hospital of Western Theater Command, Chengdu, People’s Republic of China
| | - Zaiyuan Zhang
- College of Medicine, Southwest Jiaotong University, Chengdu, People’s Republic of China
| | - Fei Han
- Department of Ophthalmology, The General Hospital of Western Theater Command, Chengdu, People’s Republic of China
| | - Pan Long
- Department of Ophthalmology, The General Hospital of Western Theater Command, Chengdu, People’s Republic of China
| | - Yonghe Hu
- College of Medicine, Southwest Jiaotong University, Chengdu, People’s Republic of China
| |
Collapse
|
5
|
Jing L, Wu N, Zhang J, Da Q, Ma H. Protective effect of 5,6,7,8-Tetrahydroxyflavone on high altitude cerebral edema in rats. Eur J Pharmacol 2022; 928:175121. [PMID: 35777443 DOI: 10.1016/j.ejphar.2022.175121] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 06/17/2022] [Accepted: 06/21/2022] [Indexed: 11/03/2022]
Abstract
High altitude cerebral edema (HACE) is a potentially life-threatening disease encountered at high altitudes. However, effective methods for HACE prophylaxis are limited. Convincing evidence confirms that oxidative stress induced by hypobaric hypoxia (HH) is one of the main factors that account for the development of HACE. 5,6,7,8-Tetrahydroxyflavone (THF), a flavone with four consecutive OH groups in ring A, exhibited excellent antioxidant activity in vitro and could attenuate HH induced injury in vivo. The aim of this study was to investigate the protective effect of THF against HACE and its underlying mechanisms. THF administration significantly suppressed HH induced oxidative stress by reducing the formation of hydrogen peroxide and malondialdehyde, by increasing the levels of glutathione and superoxide dismutase in brain tissue. Simultaneously, THF administration inhibited inflammatory responses by decreasing the levels of tumor necrosis factor-α, interleukin-1β, and interleukin-6 in serum and brain tissue. In addition, THF administration mitigated the energy metabolism disorder induced by HACE as evidenced by decreased levels of lactic acid, lactate dehydrogenase and pyruvate kinase as well as increased ATP levels and ATPase activities. Furthermore, THF administration decreased the expression of matrix metalloproteinase-9, aquaporin 4, hypoxia-inducible factor-1α and vascular endothelial growth factor, which attenuated blood-brain barrier (BBB) disruption and brain edema. Additionally, THF administration improved HACE induced cognitive dysfunction. These results show that THF is a promising agent in the prevention and treatment of HACE.
Collapse
Affiliation(s)
- Linlin Jing
- Center for Brain Science, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, 710061, China; Department of Pharmacy, The 940th Hospital of Joint Logistics Support Force of PLA, Lanzhou, Gansu, 730050, China.
| | - Ningzi Wu
- Department of Pharmacy, The 940th Hospital of Joint Logistics Support Force of PLA, Lanzhou, Gansu, 730050, China
| | - Jie Zhang
- Department of Pharmacy, The 940th Hospital of Joint Logistics Support Force of PLA, Lanzhou, Gansu, 730050, China
| | - Qingyue Da
- Center for Brain Science, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, 710061, China; Department of Pharmacy, The 940th Hospital of Joint Logistics Support Force of PLA, Lanzhou, Gansu, 730050, China
| | - Huiping Ma
- Department of Pharmacy, The 940th Hospital of Joint Logistics Support Force of PLA, Lanzhou, Gansu, 730050, China.
| |
Collapse
|
6
|
Jiang S, Fan F, Yang L, Chen K, Sun Z, Zhang Y, Cairang N, Wang X, Meng X. Salidroside attenuates high altitude hypobaric hypoxia-induced brain injury in mice via inhibiting NF-κB/NLRP3 pathway. Eur J Pharmacol 2022; 925:175015. [PMID: 35561751 DOI: 10.1016/j.ejphar.2022.175015] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 04/21/2022] [Accepted: 05/04/2022] [Indexed: 12/18/2022]
Abstract
Salidroside (Sal), an active ingredient from Rhodiola crenulate, has been reported to exert neuroprotection in cerebral injury from hypobaric hypoxia (HH) at high altitude. However, it remains to be understood whether its protective effects are related to inflammation suppression. In the present work, we aimed to reveal the mechanism of Sal attenuating HH-induced brain injury in mice caused by an animal hypobaric and hypoxic chamber. Our results provided that Sal could attenuate HH-evoked pathological injury and oxidative stress response by decreasing the content of ROS and MDA, and elevating the activities of SOD and GSH-Px. Sal treatment could partly enhance the energy metabolism, evidenced by increasing the activities of Na+-K+-ATPase, Ca2+-Mg2+-ATPase, ATP, SDH, HK and PK, while decreasing the release of LDH and LD. Meanwhile, Sal administration reversed the degradation of tight junction proteins ZO-1, Occludin and Claudin-5. Further, the increased levels of TNF-α, IL-1β and IL-6 were confined with Sal administration under the HH condition. Importantly, Sal could downregulate the proteins expression of p-NF-κB-p65, NLRP3, cleaved-Caspase-1 and ASC. Sal also decreased the protein expression of iNOS and COX2 with the increased CD206 and Arg1 expression. Taken together, these data provided that the inhibited NF-κB/NLRP3 pathway by Sal could attenuate HH-induced cerebral oxidative stress injury, inflammatory responses and the blood brain barrier (BBB) damage, attributing to the improved energy metabolism and the microglial phenotype of anti-inflammatory M2. The findings suggested that Sal was expected to be a promising anti-inflammatory agent for high altitude HH-induced brain injury.
Collapse
Affiliation(s)
- Shengnan Jiang
- School of Pharmacy, and Research Institute of Integrated TCM & Western Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, 611137, China
| | - Fangfang Fan
- School of Ethnic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, 611137, China
| | - Lu Yang
- School of Pharmacy, and Research Institute of Integrated TCM & Western Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, 611137, China
| | - Ke Chen
- School of Pharmacy, and Research Institute of Integrated TCM & Western Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, 611137, China
| | - Zhihao Sun
- School of Basic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, 611137, China
| | - Yi Zhang
- School of Ethnic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, 611137, China; Ethnic Medicine Academic Heritage Innovation Research Center, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, 611137, China
| | - Nanjia Cairang
- University of Tibetan Medicine, Lasa, Tibet, 850000, China.
| | - Xiaobo Wang
- School of Pharmacy, and Research Institute of Integrated TCM & Western Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, 611137, China; State Key Laboratory of Southwestern Chinese Medicine Resources, Innovative Institute of Chinese Medicine and Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, 611137, China.
| | - Xianli Meng
- School of Pharmacy, and Research Institute of Integrated TCM & Western Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, 611137, China; State Key Laboratory of Southwestern Chinese Medicine Resources, Innovative Institute of Chinese Medicine and Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, 611137, China.
| |
Collapse
|
7
|
Glutaredoxin Interacts with GR and AhpC to Enhance Low-Temperature Tolerance of Antarctic Psychrophile Psychrobacter sp. ANT206. Int J Mol Sci 2022; 23:ijms23031313. [PMID: 35163237 PMCID: PMC8836231 DOI: 10.3390/ijms23031313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 01/22/2022] [Accepted: 01/22/2022] [Indexed: 02/05/2023] Open
Abstract
Glutaredoxin (Grx) is an important oxidoreductase to maintain the redox homoeostasis of cells. In our previous study, cold-adapted Grx from Psychrobacter sp. ANT206 (PsGrx) has been characterized. Here, we constructed an in-frame deletion mutant of psgrx (Δpsgrx). Mutant Δpsgrx was more sensitive to low temperature, demonstrating that psgrx was conducive to the growth of ANT206. Mutant Δpsgrx also had more malondialdehyde (MDA) and protein carbonylation content, suggesting that PsGrx could play a part in the regulation of tolerance against low temperature. A yeast two-hybrid system was adopted to screen interacting proteins of 26 components. Furthermore, two target proteins, glutathione reductase (GR) and alkyl hydroperoxide reductase subunit C (AhpC), were regulated by PsGrx under low temperature, and the interactions were confirmed via bimolecular fluorescence complementation (BiFC) and co-immunoprecipitation (Co-IP). Moreover, PsGrx could enhance GR activity. trxR expression in Δpsgrx, Δahpc, and ANT206 were illustrated 3.7, 2.4, and 10-fold more than mutant Δpsgrx Δahpc, indicating that PsGrx might increase the expression of trxR by interacting with AhpC. In conclusion, PsGrx may participate in glutathione metabolism and ROS-scavenging by regulating GR and AhpC to protect the growth of ANT206. These findings preliminarily suggest the role of PsGrx in the regulation of oxidative stress, which could improve the low-temperature tolerance of ANT206.
Collapse
|
8
|
Zhu D, He B, Zhang M, Wan Y, Liu R, Wang L, Zhang Y, Li Y, Gao F. A Multimodal MR Imaging Study of the Effect of Hippocampal Damage on Affective and Cognitive Functions in a Rat Model of Chronic Exposure to a Plateau Environment. Neurochem Res 2022; 47:979-1000. [PMID: 34981302 PMCID: PMC8891211 DOI: 10.1007/s11064-021-03498-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 11/18/2021] [Accepted: 11/23/2021] [Indexed: 02/05/2023]
Abstract
Prolonged exposure to high altitudes above 2500 m above sea level (a.s.l.) can cause cognitive and behavioral dysfunctions. Herein, we sought to investigate the effects of chronic exposure to plateau hypoxia on the hippocampus in a rat model by using voxel-based morphometry, creatine chemical exchange saturation transfer (CrCEST) and dynamic contrast-enhanced MR imaging techniques. 58 healthy 4-week-old male rats were randomized into plateau hypoxia rats (H group) as the experimental group and plain rats (P group) as the control group. H group rats were transported from Chengdu (500 m a.s.l.), a city in a plateau located in southwestern China, to the Qinghai-Tibet Plateau (4250 m a.s.l.), Yushu, China, and then fed for 8 months there, while P group rats were fed in Chengdu (500 m a.s.l.), China. After 8 months of exposure to plateau hypoxia, open-field and elevated plus maze tests revealed that the anxiety-like behavior of the H group rats was more serious than that of the P group rats, and the Morris water maze test revealed impaired spatial memory function in the H group rats. Multimodal MR imaging analysis revealed a decreased volume of the regional gray matter, lower CrCEST contrast and higher transport coefficient Ktrans in the hippocampus compared with the P group rats. Further correlation analysis found associations of quantitative MRI parameters of the hippocampus with the behavioral performance of H group rats. In this study, we validated the viability of using noninvasive multimodal MR imaging techniques to evaluate the effects of chronic exposure to a plateau hypoxic environment on the hippocampus.
Collapse
Affiliation(s)
- Dongyong Zhu
- Department of Radiology, West China Hospital, Sichuan University, No. 37 Guoxue Road, Chengdu, 610041, China
| | - Bo He
- Department of Radiology, West China Hospital, Sichuan University, No. 37 Guoxue Road, Chengdu, 610041, China
| | - Mengdi Zhang
- Department of Radiology, West China Hospital, Sichuan University, No. 37 Guoxue Road, Chengdu, 610041, China
| | - Yixuan Wan
- Department of Radiology, West China Hospital, Sichuan University, No. 37 Guoxue Road, Chengdu, 610041, China
| | - Ruibin Liu
- Department of Biomedical Engineering, College of Biomedical Engineering and Instrument Science, Zhejiang University, Hangzhou, 310030, China
| | - Lei Wang
- Molecular Imaging Center, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Yi Zhang
- Department of Biomedical Engineering, College of Biomedical Engineering and Instrument Science, Zhejiang University, Hangzhou, 310030, China
| | - Yunqing Li
- Department of Anatomy and KK Leung Brain Research Centre, The Fourth Military Medical University, Xi'an, 710032, China
| | - Fabao Gao
- Department of Radiology, West China Hospital, Sichuan University, No. 37 Guoxue Road, Chengdu, 610041, China. .,Molecular Imaging Center, West China Hospital, Sichuan University, Chengdu, 610041, China.
| |
Collapse
|
9
|
Rac1/Wave2/Arp3 Pathway Mediates Rat Blood-Brain Barrier Dysfunction under Simulated Microgravity Based on Proteomics Strategy. Int J Mol Sci 2021; 22:ijms22105165. [PMID: 34068233 PMCID: PMC8153163 DOI: 10.3390/ijms22105165] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Revised: 05/07/2021] [Accepted: 05/08/2021] [Indexed: 01/09/2023] Open
Abstract
The blood-brain barrier (BBB) is critical to maintaining central nervous system (CNS) homeostasis. However, the effects of microgravity (MG) on the BBB remain unclear. This study aimed to investigate the influence of simulated MG (SMG) on the BBB and explore its potential mechanism using a proteomic approach. Rats were tail-suspended to simulate MG for 21 days. SMG could disrupt the BBB, including increased oxidative stress levels, proinflammatory cytokine levels, and permeability, damaged BBB ultrastructure, and downregulated tight junctions (TJs) and adherens junctions (AJs) protein expression in the rat brain. A total of 554 differentially expressed proteins (DEPs) induced by SMG were determined based on the label-free quantitative proteomic strategy. The bioinformatics analysis suggested that DEPs were mainly enriched in regulating the cell–cell junction and cell–extracellular matrix biological pathways. The inhibited Ras-related C3 botulinum toxin substrate 1 (Rac1)/Wiskott–Aldrich syndrome protein family verprolin-homologous protein 2 (Wave2)/actin-related protein 3 (Arp3) pathway and the decreased ratio of filamentous actin (F-actin) to globular actin contributed to BBB dysfunction induced by SMG. In the human brain microvascular endothelial cell (HBMECs), SMG increased the oxidative stress levels and proinflammatory cytokine levels, promoted apoptosis, and arrested the cell cycle phase. Expression of TJs and AJs proteins were downregulated and the distribution of F-actin was altered in SMG-treated HBMECs. The key role of the Rac1/Wave2/Arp3 pathway in BBB dysfunction was confirmed in HBMECs with a specific Rac1 agonist. This study demonstrated that SMG induced BBB dysfunction and revealed that Rac1/Wave2/Arp3 could be a potential signaling pathway responsible for BBB disruption under SMG. These results might shed a novel light on maintaining astronaut CNS homeostasis during space travel.
Collapse
|