Min Shen1, Shan Wang1, Xin Wen1, Xin-Rui Han1, Yong-Jian Wang1, Xiu-Min Zhou2, Man-He Zhang2, Dong-Mei Wu3, Jun Lu4, Yuan-Lin Zheng5. 1. Key Laboratory for Biotechnology on Medicinal Plants of Jiangsu Province, School of Life Science, Jiangsu Normal University, Xuzhou 221116, PR China. 2. Department of Anesthesiology, Tangshan Gongren Hospital, Tangshan 063000, PR China. 3. Key Laboratory for Biotechnology on Medicinal Plants of Jiangsu Province, School of Life Science, Jiangsu Normal University, Xuzhou 221116, PR China. Electronic address: wdm8610@jsnu.edu.cn. 4. Key Laboratory for Biotechnology on Medicinal Plants of Jiangsu Province, School of Life Science, Jiangsu Normal University, Xuzhou 221116, PR China. Electronic address: lu-jun75@163.com. 5. Key Laboratory for Biotechnology on Medicinal Plants of Jiangsu Province, School of Life Science, Jiangsu Normal University, Xuzhou 221116, PR China. Electronic address: ylzheng@jsnu.edu.cn.
Abstract
OBJECTIVE: This study aims to explore the neuroprotective effects of dexmedetomidine (Dex) in rats suffering from traumatic brain injury (TBI) via the PI3K/Akt/mTOR signaling pathway. METHODS: A weight drop model was performed for TBI model establishment. A total of 150 Sprague Dawley rats were selected and assigned into control, sham, TBI, TBI+Dex, TBI+LY294002 (LY) and TBI+Dex+LY groups. Modified Neurological Severity Score (mNSS) was conducted in order to evaluate the neurological injury. The water content in brain tissues was measured. The expressions of PI3K/Akt/mTOR signaling pathway-related proteins, tight junction proteins (ZO-1 and Claudin-5) and autophagy proteins (LC3 I/II and Beclin-1) were detected using Western blot assay. A TUNEL assay was applied for cell apoptosis, immunofluorescence was employed for the detection of the positive expression of LC3, and ELISA was applied for detection of levels of inflammatory factors [tumor necrosis factor-alph (TNF-a), interleukin-1β (IL-1β), interferon-γ (INF-γ) as well as IL-6], respectively. RESULTS: Compared with the control group, the other four groups exhibited increased mNSS, brain water content, expression of LC3, TNF-a, IL-1β, INF-γ and IL-6, and positive expression of LC3, expression of LC3 I/II and Beclin-1, but decreased expression of pp-PI3K/t-PI3K, p-Akt/t-Akt, p-mTOR/t-mTOR, ZO-1 and Claudin-5. Compared with the TBI group, the TBI+Dex group exhibited reduced mNSS, brain water content, expression of LC3, TNF-a, IL-1β, INF-γ and IL-6, positive expression of LC3, as well as expression of LC3 I/II and Beclin-1 but demonstrated an elevated expression of pp-PI3K/t-PI3K, p-Akt/t-Akt, p-mTOR/t-mTOR, ZO-1 and Claudin-5, while opposite trends were observed in the TBI+LY group. The TBI+Dex group exhibited reduced mNSS, brain water content, expression of LC3, TNF-a, IL-1β, INF-γ and IL-6, positive expression of LC3, as well as expression of LC3 I/II and Beclin-1 but demonstrated an elevated expression of pp-PI3K/t-PI3K, p-Akt/t-Akt, p-mTOR/t-mTOR, ZO-1 and Claudin-5, while opposite trends were observed in the TBI+LY group, as compared with the TBI+Dex+LY group. CONCLUSION: The data shows that Dex exerts a neuroprotective effect via the activation of the PI3K/Akt/mTOR signaling pathway in rats with TBI.
OBJECTIVE: This study aims to explore the neuroprotective effects of dexmedetomidine (Dex) in rats suffering from traumatic brain injury (TBI) via the PI3K/Akt/mTOR signaling pathway. METHODS: A weight drop model was performed for TBI model establishment. A total of 150 Sprague Dawley rats were selected and assigned into control, sham, TBI, TBI+Dex, TBI+LY294002 (LY) and TBI+Dex+LY groups. Modified Neurological Severity Score (mNSS) was conducted in order to evaluate the neurological injury. The water content in brain tissues was measured. The expressions of PI3K/Akt/mTOR signaling pathway-related proteins, tight junction proteins (ZO-1 and Claudin-5) and autophagy proteins (LC3 I/II and Beclin-1) were detected using Western blot assay. A TUNEL assay was applied for cell apoptosis, immunofluorescence was employed for the detection of the positive expression of LC3, and ELISA was applied for detection of levels of inflammatory factors [tumor necrosis factor-alph (TNF-a), interleukin-1β (IL-1β), interferon-γ (INF-γ) as well as IL-6], respectively. RESULTS: Compared with the control group, the other four groups exhibited increased mNSS, brain water content, expression of LC3, TNF-a, IL-1β, INF-γ and IL-6, and positive expression of LC3, expression of LC3 I/II and Beclin-1, but decreased expression of pp-PI3K/t-PI3K, p-Akt/t-Akt, p-mTOR/t-mTOR, ZO-1 and Claudin-5. Compared with the TBI group, the TBI+Dex group exhibited reduced mNSS, brain water content, expression of LC3, TNF-a, IL-1β, INF-γ and IL-6, positive expression of LC3, as well as expression of LC3 I/II and Beclin-1 but demonstrated an elevated expression of pp-PI3K/t-PI3K, p-Akt/t-Akt, p-mTOR/t-mTOR, ZO-1 and Claudin-5, while opposite trends were observed in the TBI+LY group. The TBI+Dex group exhibited reduced mNSS, brain water content, expression of LC3, TNF-a, IL-1β, INF-γ and IL-6, positive expression of LC3, as well as expression of LC3 I/II and Beclin-1 but demonstrated an elevated expression of pp-PI3K/t-PI3K, p-Akt/t-Akt, p-mTOR/t-mTOR, ZO-1 and Claudin-5, while opposite trends were observed in the TBI+LY group, as compared with the TBI+Dex+LY group. CONCLUSION: The data shows that Dex exerts a neuroprotective effect via the activation of the PI3K/Akt/mTOR signaling pathway in rats with TBI.
Authors: Pavel N Lizhnyak; Pretal P Muldoon; Pallavi P Pilaka; John T Povlishock; Andrew K Ottens Journal: J Neurotrauma Date: 2019-07-31 Impact factor: 5.269
Authors: Volha Liaudanskaya; Joon Yong Chung; Craig Mizzoni; Nicolas Rouleau; Alexander N Berk; Limin Wu; Julia A Turner; Irene Georgakoudi; Michael J Whalen; Thomas J F Nieland; David L Kaplan Journal: Adv Healthc Mater Date: 2020-05-13 Impact factor: 9.933